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General Discussion => New Physics for Space Technology => Topic started by: EdT on 06/27/2012 11:52 pm

Title: EM Drive Developments Thread 1
Post by: EdT on 06/27/2012 11:52 pm
Any current news on the development of the EMDrive ?

Latest entry by the company was in June 2011.  SPR has not responded to my request for any new developments.

http://www.wired.com/dangerroom/2008/09/chinese-buildin/
http://www.emdrive.com/

http://www.wired.com/images_blogs/dangerroom/images/2008/09/24/emdrive_2.jpg
Title: Re: EM Drive Developments
Post by: QuantumG on 06/27/2012 11:56 pm
I hear North Korea is building one too.

Title: Re: EM Drive Developments
Post by: docmordrid on 06/28/2012 12:10 am
I *think* there was an article about an Infinite Improbability Drive around here somewhere..  ;)

Answer: not much that is credible.
Title: Re: EM Drive Developments
Post by: JBF on 04/29/2013 12:45 am
New information up on http://www.emdrive.com/ (http://www.emdrive.com/)

November 2012

China publishes high power test results

The prestigious Chinese Academy of Sciences has published a paper by Professor Yang Juan confirming their high power test results. At an input power of 2.5kW, their 2.45GHz EmDrive thruster provides 720mN of thrust. The results have clearly been subject to extensive peer review following the NWPU 2010 paper. The measurements were made on a national standard, thrust measurement device, used for Ion Engine development. Details of the measurement system and calibration data are given in the paper. A professional English translation is given here: http://www.emdrive.com/yang-juan-paper-2012.pdf

Well, newer than the last comment in any case.
Title: Re: EM Drive Developments
Post by: grondilu on 05/03/2013 09:42 pm
At an input power of 2.5kW, their 2.45GHz EmDrive thruster provides 720mN of thrust.

A photon has energy E = hf and momentum  p = hf / c = E / c

F = dp/dt = dE/dt / c

So even if all the energy was converted into photons all emited in the desired direction, that would make a force:

F = 2.5e3/3e8 = 8e-6 N

That's 90 000 times less than 720 mN.

Where am I wrong?



Title: Re: EM Drive Developments
Post by: Nathan on 05/03/2013 10:10 pm
At an input power of 2.5kW, their 2.45GHz EmDrive thruster provides 720mN of thrust.

A photon has energy E = hf and momentum  p = hf / c = E / c

F = dp/dt = dE/dt / c

So even if all the energy was converted into photons all emited in the desired direction, that would make a force:

F = 2.5e3/3e8 = 8e-6 N

That's 90 000 times less than 720 mN.

Where am I wrong?


Read the papers. You are missing the q factors, relativity etc. work thru the math in the paper then make a post. I did it and even though I'm not entirely convinced I am thinking that it is a possibility- especially given that the effect has been independently confirmed.
It needs a serious look.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 07/31/2014 03:04 pm
New paper describing encouraging results from the testing of an 'EM-drive' like device.
http://ntrs.nasa.gov/search.jsp?R=20140006052 (http://ntrs.nasa.gov/search.jsp?R=20140006052)
Hope it stands up to further scrutiny. Could be a real game changer!
Title: Re: EM Drive Developments
Post by: Stormbringer on 07/31/2014 04:38 pm
say...one of the names of that paper as opposed to the Wired article on this has:

Quote
Brady, David   (NASA Johnson Space Center, Houston, TX, United States);   
White, Harold G.   (NASA Johnson Space Center, Houston, TX, United States);   
March, Paul   (NASA Johnson Space Center, Houston, TX, United States);   
Lawrence, James T.   (NASA Johnson Space Center, Houston, TX, United States);   
Davies, Frank J.   (NASA Johnson Space Center, Houston, TX, United States)

Harold white of QVPT and warp drive fame and Paul March of Machs Principle fame.

i sense a disturbance in the force...

it's as if the forces of maverick science reached out and slapped establishment science with a wet tuna.  :)
Title: Re: EM Drive Developments
Post by: Star One on 07/31/2014 05:13 pm
Well it's appeared again.

http://www.wired.co.uk/news/archive/2014-07/31/nasa-validates-impossible-space-drive

This is the main link.

http://ntrs.nasa.gov/search.jsp?R=20140006052

Anyone notice Harold 'warp drive' White is one of the authors on this?
Title: Re: EM Drive Developments
Post by: KelvinZero on 07/31/2014 05:43 pm
New paper describing encouraging results from the testing of an 'EM-drive' like device.
http://ntrs.nasa.gov/search.jsp?R=20140006052 (http://ntrs.nasa.gov/search.jsp?R=20140006052)
Hope it stands up to further scrutiny. Could be a real game changer!
Yep.. free energy. Forget the heat death of the universe, we will just keep creating additional mass locally.

Hmm.. actually perhaps this answers the Fermi paradox.
It may simply be impossible for a species spread across the stars with access to free energy and mass to have the discipline to not create more living space exponentially, and eventually suck its local group into a black hole.  :)
Title: Re: EM Drive Developments
Post by: Dunners73 on 07/31/2014 05:44 pm
Not sure this is related to the emdrive, think this is that Q thruster concept.
regardless, the abstract makes it sound more negative than positive.

"..Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)."

Like the placebo in a drug trial showing the same "effect".

Title: Re: EM Drive Developments
Post by: Star One on 07/31/2014 05:45 pm

Not sure this is related to the emdrive, think this is that Q thruster concept.
regardless, the abstract makes it sound more negative than positive.

"..Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)."

Like the placebo in a drug trial showing the same "effect".

From my limited understanding of the topic I wasn't sure why these two were linked together in the Wired article, are they really that closely related?
Title: Re: EM Drive Developments
Post by: Stormbringer on 07/31/2014 05:54 pm

Not sure this is related to the emdrive, think this is that Q thruster concept.
regardless, the abstract makes it sound more negative than positive.

"..Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)."

Like the placebo in a drug trial showing the same "effect".

From my limited understanding of the topic I wasn't sure why these two were linked together in the Wired article, are they really that closely related?
i think they are part of a broad classification of propulsion, etc labelled Space drives? maybe that is why?
Title: Re: EM Drive Developments
Post by: Dunners73 on 07/31/2014 06:03 pm

Not sure this is related to the emdrive, think this is that Q thruster concept.
regardless, the abstract makes it sound more negative than positive.

"..Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)."

Like the placebo in a drug trial showing the same "effect".

From my limited understanding of the topic I wasn't sure why these two were linked together in the Wired article, are they really that closely related?

I dont think they are very similar at all. - The Q thruster attempts to act upon underlying virtual particles to produce thrust without reaction mass while the EMdrive is trying a scheme of pumping microwaves into a sealed high Q (which equates to highly internally reflective) chamber, where one end is a different geometry to the other.

I suppose the results might be similar..  :-X
Title: Re: EM Drive Developments
Post by: john smith 19 on 07/31/2014 06:35 pm
Well it's appeared again.

http://www.wired.co.uk/news/archive/2014-07/31/nasa-validates-impossible-space-drive

This is the main link.

http://ntrs.nasa.gov/search.jsp?R=20140006052

Anyone notice Harold 'warp drive' White is one of the authors on this?

Reading the NASA papers (which is damm strange. It's more like an extended abstract. Is this due to be presented somewhere) shows it's nothing to do with the Chinese EM thruster work but is Sonny White's Quantum Vacuum Thruster

Here's the weird thing.

"within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure. "
Personally I could see that 35-50 micro Newton (1x10^-6) being a microwave heating effect on the air.  :(

Show that with door on the chamber closed and the air pumped out makes the situation much more interesting.

Clearly the dear old Wired reports have conflated the QVT work with the EM thruster work, although I have to admit from a superficial reading the two seem similar.
Title: Re: EM Drive Developments
Post by: Star One on 07/31/2014 06:45 pm
Is it me or did that Wired article do this topic no favours, this stuff is right on the edge of technology and understanding and conflating things like that isn't helping?

Those more knowledgable than me is the NASA link helpful at all?
Title: Re: EM Drive Developments
Post by: NovaSilisko on 07/31/2014 06:56 pm
And so begins the flailing by the uninformed once again.
Title: Re: EM Drive Developments
Post by: Elmar Moelzer on 07/31/2014 07:12 pm
Quote
Manual frequency control was required throughout the test. Thrust was observed on both test
articles, even though one of the test articles was designed with the expectation that it would not produce
thrust. Specifically, one test article contained internal physical modifications that were designed to produce
thrust, while the other did not (with the latter being referred to as the “null” test article).
This looks like an issue to me that indicates a problem with their setup. Also, if I interpret their video on vimeo correctly, then their test setup has the problem that their power supply is in a different reference frame. From what I remember from previous discussions on the topic, that may distort the results:
http://vimeo.com/29837879
Title: Re: EM Drive Developments
Post by: Star One on 07/31/2014 09:19 pm
Sounds like more testing on this is in hand.

Dug up another article not sure if it adds anything much or not. Let's see if it survives further scrutiny to become something to keep eye on.

http://nextbigfuture.com/2014/07/renewed-hope-for-emdrive-with-nasa.html
Title: Re: EM Drive Developments
Post by: IslandPlaya on 07/31/2014 10:29 pm
Quote
Manual frequency control was required throughout the test. Thrust was observed on both test
articles, even though one of the test articles was designed with the expectation that it would not produce
thrust. Specifically, one test article contained internal physical modifications that were designed to produce
thrust, while the other did not (with the latter being referred to as the “null” test article).
This looks like an issue to me that indicates a problem with their setup. Also, if I interpret their video on vimeo correctly, then their test setup has the problem that their power supply is in a different reference frame. From what I remember from previous discussions on the topic, that may distort the results:
http://vimeo.com/29837879
Can you explain more about the power supply being in a different reference frame?
Surely it is not. It is at rest compared to the test device.
Title: Re: EM Drive Developments
Post by: Stormbringer on 07/31/2014 11:28 pm
Well it's appeared again.

http://www.wired.co.uk/news/archive/2014-07/31/nasa-validates-impossible-space-drive

This is the main link.

http://ntrs.nasa.gov/search.jsp?R=20140006052

Anyone notice Harold 'warp drive' White is one of the authors on this?

and Paul March. of Woodward Mach principle fame. :)

woohoo!
Title: Re: EM Drive Developments
Post by: Elmar Moelzer on 07/31/2014 11:52 pm
It is at rest compared to the test device.
Exactly, it is NOT being accelerated with the thruster.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/01/2014 12:37 am
I wouldn't dream of posting here....
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/01/2014 01:23 am
I wouldn't dream of posting here....
I can understand the skepticism...
However the experimenters are all NASA scientists.
What is the problem? are you a better scientist John F? Or do you think the authors should be stripped of their NASA posts?
Maybe we should calm down and investigate further?
Heavens!
Title: Re: EM Drive Developments
Post by: QuantumG on 08/01/2014 01:32 am
Well, clearly, if they're NASA scientists they couldn't possibly be wrong.  ::)
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/01/2014 01:37 am
I happen to be a "NASA scientist" and a physicist, and I think it's (unprintable). I'm not saying that in any sort of official capacity. But really, extraordinary claims require extraordinary evidence. Or: "The first principle is that you must not fool yourself and you are the easiest person to fool." - Richard P. Feynman

Also, just because someone is skeptical of someone's results (or that they prove out to be wrong) doesn't mean you think they should be fired! If that was the standard, we'd all be fired at some point.
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/01/2014 01:39 am
It's important to realize this is a technical report, NOT a published journal article. If they got this published in, say, Physical Review Letters, then we've got something potentially interesting.
Title: Re: EM Drive Developments
Post by: ncb1397 on 08/01/2014 03:32 am
Every generation has thought to themselves that they have figured out most everything there is to know or discover and each successive generation has been proven wrong. We must admit to ourselves that the unknown unknowns could be a vast expanse and relatively speaking, we are simply a couple short millenia and a very short distance past smashing rocks together to get fire.
Title: Re: EM Drive Developments
Post by: QuantumG on 08/01/2014 03:41 am
Every generation has thought to themselves that the previous generation is a bunch of stick-in-the-muds who should have a more open mind, waxing philosophical about what might be, and then failed to produce anything new until they adopted a skeptical mindset.. thus becoming the next generation of stick-in-the-muds.

We're not skeptical because we think we know it all.. we're skeptical because it works.

Title: Re: EM Drive Developments
Post by: Robotbeat on 08/01/2014 03:42 am
Sure. But Occam's Razor and Bayesian statistics (there's a strong prior, here) suggests the most likely explanation is some sort of screw up. Same deal with that ostensibly faster than light neutrino thing of yesteryear.
Title: Re: EM Drive Developments
Post by: sanman on 08/01/2014 04:21 am
Is NASA the only one who can test things? Surely this is a matter for major laboratories and university research teams to take a look at - even if only to issue a definitive disproof.



Title: Re: EM Drive Developments
Post by: CriX on 08/01/2014 05:05 am
I know very little about this, but it doesn't seem to claim free energy.  Sonny describes the "q thruster" as being essentially like a water propeller, except pushing against vacuum virtual particles.... which sounds plausible... to these foolish ears.  It's definitely disconcerting that even their null device produced "thrust" though. 
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/01/2014 05:22 am
I know very little about this, but it doesn't seem to claim free energy.  Sonny describes the "q thruster" as being essentially like a water propeller, except pushing against vacuum virtual particles.... which sounds plausible... to these foolish ears.  It's definitely disconcerting that even their null device produced "thrust" though.
The end result for these propellantless propulsion devices is free energy, though.
Title: Re: EM Drive Developments
Post by: MP99 on 08/01/2014 06:04 am
Quote
Manual frequency control was required throughout the test. Thrust was observed on both test
articles, even though one of the test articles was designed with the expectation that it would not produce
thrust. Specifically, one test article contained internal physical modifications that were designed to produce
thrust, while the other did not (with the latter being referred to as the “null” test article).
This looks like an issue to me that indicates a problem with their setup. Also, if I interpret their video on vimeo correctly, then their test setup has the problem that their power supply is in a different reference frame. From what I remember from previous discussions on the topic, that may distort the results:
http://vimeo.com/29837879
Can you explain more about the power supply being in a different reference frame?
Surely it is not. It is at rest compared to the test device.
If the PSU experiences an equal but opposite thrust while bolted down to the desk, then no one would notice, but it would invalidate it as a thruster.

Cheers, Martin
Title: Re: EM Drive Developments
Post by: Star One on 08/01/2014 07:57 am
Is NASA the only one who can test things? Surely this is a matter for major laboratories and university research teams to take a look at - even if only to issue a definitive disproof.

I assume because the scientific establishment don't want to know for whatever reason, which too me knowing the history of how things can come from left field is perhaps not so good? From a theoretical viewpoint it would be quite interesting if there did turn out to be something in it because by the looks of it would require some re-thinking of certain areas of theory.
Title: Re: EM Drive Developments
Post by: kerlc on 08/01/2014 08:41 am
Could it be possible that this is merely another open system, like solar sails?
Title: Re: EM Drive Developments
Post by: Lee Jay on 08/01/2014 08:57 am
Since this was done in air, could it be this effect, which is real but unremarkable?

http://youtu.be/2uD9wtq29h8
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/01/2014 09:04 am
Is NASA the only one who can test things? Surely this is a matter for major laboratories and university research teams to take a look at - even if only to issue a definitive disproof.

I assume because the scientific establishment don't want to know for whatever reason, which too me knowing the history of how things can come from left field is perhaps not so good? From a theoretical viewpoint it would be quite interesting if there did turn out to be something in it because by the looks of it would require some re-thinking of certain areas of theory.

Right, the "scientific establishment" don't want to know.  Because we all know the "scientific establishment" is a hive mind that makes collective decisions.  It's definitely not hundreds of thousands of individuals who have a love of knowledge and desire to find out about the world we live in.  It can't possibly be that those hundreds of thousands of individuals in dozens of countries are free to do whatever research they want to.

And it's just not possible that reputable scientists aren't spending their time on this because they honestly believe that it would be a waste of their time, and that they have the education, experience, and intelligence to tell science from pseudo-science.
Title: Re: EM Drive Developments
Post by: Star One on 08/01/2014 09:12 am

Is NASA the only one who can test things? Surely this is a matter for major laboratories and university research teams to take a look at - even if only to issue a definitive disproof.

I assume because the scientific establishment don't want to know for whatever reason, which too me knowing the history of how things can come from left field is perhaps not so good? From a theoretical viewpoint it would be quite interesting if there did turn out to be something in it because by the looks of it would require some re-thinking of certain areas of theory.

Right, the "scientific establishment" don't want to know.  Because we all know the "scientific establishment" is a hive mind that makes collective decisions.  It's definitely not hundreds of thousands of individuals who have a love of knowledge and desire to find out about the world we live in.  It can't possibly be that those hundreds of thousands of individuals in dozens of countries are free to do whatever research they want to.

And it's just not possible that reputable scientists aren't spending their time on this because they honestly believe that it would be a waste of their time, and that they have the education, experience, and intelligence to tell science from pseudo-science.

Yeah the same scientific establishment that spent so long saying oh no there is nothing like plate tectonics, the Big Bang or lead in fuel actually causing health effects. I bet you could come up with plenty of examples usually ending with whoops we were wrong & in fact the mavericks were right.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/01/2014 09:57 am

Is NASA the only one who can test things? Surely this is a matter for major laboratories and university research teams to take a look at - even if only to issue a definitive disproof.

I assume because the scientific establishment don't want to know for whatever reason, which too me knowing the history of how things can come from left field is perhaps not so good? From a theoretical viewpoint it would be quite interesting if there did turn out to be something in it because by the looks of it would require some re-thinking of certain areas of theory.

Right, the "scientific establishment" don't want to know.  Because we all know the "scientific establishment" is a hive mind that makes collective decisions.  It's definitely not hundreds of thousands of individuals who have a love of knowledge and desire to find out about the world we live in.  It can't possibly be that those hundreds of thousands of individuals in dozens of countries are free to do whatever research they want to.

And it's just not possible that reputable scientists aren't spending their time on this because they honestly believe that it would be a waste of their time, and that they have the education, experience, and intelligence to tell science from pseudo-science.

Yeah the same scientific establishment that spent so long saying oh no there is nothing like plate tectonics, the Big Bang or lead in fuel actually causing health effects. I bet you could come up with plenty of examples usually ending with whoops we were wrong & in fact the mavericks were right.

Those examples you gave are all cases where there was inconclusive evidence at the time and robust scientific debate.  None of it was considered pseudo-science.  It wasn't remotely like the scientific attitude toward the EmDrive and Sonny White's theories.

Plate tectonics, the Big Bang theory, and health effects of lead were all cases of scientific theory evolving to encompass new evidence.  The EmDrive and White's theories are the opposite -- they put the theory first and then go looking for evidence afterwards.  In both cases, the theories claim to be consequences of existing theories in physics, but reputable physicists say that in fact they come from misunderstandings of current theories.
Title: Re: EM Drive Developments
Post by: knowles2 on 08/01/2014 10:14 am
Well now have three separate teams all reporting positive results with two different devices, to me it seem like there something here that need further exploration.
Title: Re: EM Drive Developments
Post by: Star One on 08/01/2014 10:51 am
Well now have three separate teams all reporting positive results with two different devices, to me it seem like there something here that need further exploration.

Precisely. I am pretty certain that smart people like those from NASA here wouldn't have been persuaded to waste both their valuable time and effort unless they thought it was worth looking into. It's more than possible (in fact at this time it's likely) there is nothing in it but they are at least looking into it even if it ends up disproving it the effort is still a worthwhile one in my view. Even if by some very remote chance it's correct wouldn't we all be kicking ourselves if we had missed that opportunity?

999/1000 these things prove to be wrong or an error somewhere along the line, it's the 1 that makes them interesting.:)
Title: Re: EM Drive Developments
Post by: ncb1397 on 08/01/2014 04:19 pm
Every generation has thought to themselves that the previous generation is a bunch of stick-in-the-muds who should have a more open mind, waxing philosophical about what might be, and then failed to produce anything new until they adopted a skeptical mindset.. thus becoming the next generation of stick-in-the-muds.

We're not skeptical because we think we know it all.. we're skeptical because it works.

Skepticism cuts both ways - established science and new science. There are so many gaping holes in astrophysics, you should be as skeptical of the established view of how things work as you are of something that doesn't fit the current view. Scientists have blind spots. All those scientists before Einstien had no problem with light traveling at the speed of light from every reference frame even though the only logical result of applying their rules would be an incoherent universe.  Applying current physics to the universe yields all sorts of stop-gap measures like dark energy and dark matter.

Anyways, skepticism and an open mind are not opposing things. In fact, the opposite of an open mind is a closed mind, and a closed mind is not skeptical of its own viewpoint and therefore is not practicing true skepticism.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/01/2014 06:10 pm
Well now have three separate teams all reporting positive results with two different devices, to me it seem like there something here that need further exploration.

The EmDrive has nothing to do with Sonny White's device, so it makes no sense to lump them together.

And in one of the tests both the test device and the control device showed thrust, indicating the measured effect was a result of error in the test setup, not success by the device.

So, not a lot of indication of anything interesting going on.
Title: Re: EM Drive Developments
Post by: AlanSE on 08/01/2014 06:41 pm
Well now have three separate teams all reporting positive results with two different devices, to me it seem like there something here that need further exploration.

The EmDrive has nothing to do with Sonny White's device, so it makes no sense to lump them together.

And in one of the tests both the test device and the control device showed thrust, indicating the measured effect was a result of error in the test setup, not success by the device.

So, not a lot of indication of anything interesting going on.

It's hard to tell what's going on in this comment. I think you might have in mind one of Dr. White's other proposals, for warp drives or something. His more recent publication is at least somewhat relevant:

http://ntrs.nasa.gov/search.jsp?R=20140006052

Here, he writes about "momentum transfer" via virtual particles of some plasma or something. But the use of the word "transfer" itself seems to indicate that they have no intention to sell this as a reactionless drive, making it different from the crackpots out there. Nonetheless, they are publishing about producing a force due to some bizarre quantum field theory effect. I don't even believe this, but it's worth some scientific articles until people can pin down exactly what the reproducibility and scale of the effect is. It would be overly-generous to suggest that the EmDrive was measuring this effect. They did both look at "anomalous thrust", but of completely different kinds.
Title: Re: EM Drive Developments
Post by: scienceguy on 08/01/2014 06:51 pm
Don't the vacuum fluctuations only exist for 10^-44 s each (the Planck time)? How can you possibly transfer enough momentum to anything in 10^-44 s?
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/01/2014 06:58 pm
Since this was done in air, could it be this effect, which is real but unremarkable?

http://youtu.be/2uD9wtq29h8

maybe but unless i am recalling incorrectly Dr Woodward's version of this (which is different in execution than this, but same basic class of idea) is tested in a vacuum chamber with the atmosphere evacuated to exclude ion related effects.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/01/2014 07:03 pm
Don't the vacuum fluctuations only exist for 10^-44 s each (the Planck time)? How can you possibly transfer enough momentum to anything in 10^-44 s?

i'm not a scientist and I may get jumped on for saying this but isn't it true that in the QED math there are particles and things smaller than the plank limit? They are discarded as mathematical artifacts but what if they aren't? that's basically part of Dr Woodward's thinking on how to get something (negative energy or exposing the naked rest mass) out of mach's principle.

i cannot elaborate beyond that because i do not know the theory or the math but am going by one of Dr Woodward's videos. so don't ask me for more. but maybe someone here can fill it out further?
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/01/2014 07:25 pm
If the null device also produced measurable thrust, then the effect is an artifact, to high confidence. This is the reason for having a null sample. It helps makes sure you're not fooling yourself.
Title: Re: EM Drive Developments
Post by: Star One on 08/01/2014 07:35 pm
This is the most lucid article I've read on this and at least it doesn't muddle the two up and it contains some additional comment. Half the problem with this story seems to be the muddled reporting of it.

http://www.popsci.com/article/technology/fuel-less-space-drive-may-actually-work-says-nasa?dom=PSC&loc=recent&lnk=5&con=fuelless-space-drive-may-actually-work-says-nasa

It clearly states the device tested was not White's device but it was similar.

It also states they are looking for the results to be peer reviewed.
Title: Re: EM Drive Developments
Post by: Star One on 08/01/2014 08:23 pm
New paper describing encouraging results from the testing of an 'EM-drive' like device.
http://ntrs.nasa.gov/search.jsp?R=20140006052 (http://ntrs.nasa.gov/search.jsp?R=20140006052)
Hope it stands up to further scrutiny. Could be a real game changer!

Hello we've now got two threads on this.

I used this existing thread from last year?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/01/2014 08:27 pm
New paper describing encouraging results from the testing of an 'EM-drive' like device.
http://ntrs.nasa.gov/search.jsp?R=20140006052 (http://ntrs.nasa.gov/search.jsp?R=20140006052)
Hope it stands up to further scrutiny. Could be a real game changer!

Hello we've now got two threads on this.

I used this existing thread from last year?
Yes. I did a search before I created a new topic but somehow missed the EM drive thread. Doh!
Not sure what to do about it now... Apologies.
Title: Re: EM Drive Developments
Post by: iamlucky13 on 08/01/2014 08:33 pm
Reading the abstract, Crix seems to be on the right track about quantum mechanics, but I don't know enough to speculate from there what would be happening:

Quote
Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.

However, it appears to me that there is a problem being ignored by the media that are reporting on this:

Quote
Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)

Since one experiment that should NOT have detected thrust did detect thrust, that calls into question whether there was a mistake in the test setup. Since the test chamber was not at a vacuum, I'd call that a very likely source for error. A more promising possibility is it detects thrust in configurations they didn't expect, but the simpler explanation is the former.
Title: Re: EM Drive Developments
Post by: sghill on 08/01/2014 08:54 pm

Quote
Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)

Since one experiment that should NOT have detected thrust did detect thrust, that calls into question whether there was a mistake in the test setup. Since the test chamber was not at a vacuum, I'd call that a very likely source for error. A more promising possibility is it detects thrust in configurations they didn't expect, but the simpler explanation is the former.

That was exactly my thought too.
Title: Re: EM Drive Developments
Post by: iamlucky13 on 08/01/2014 08:58 pm
The end result for these propellantless propulsion devices is free energy, though.

No, it wouldn't be free energy. You need energy to generate the RF. What it avoids is needing classical mass to transfer momentum.  An electric car also requires energy but no propellant, but it achieves momentum transfer by reacting against the ground.

Conservation of momentum is the hangup.

An affect we know about is radiation pressure: photons have momentum. Hence why a solar sail can work even without a solar wind.

As far as I know, any antenna that is not omnidirectional would produce a small amount of net thrust. But incredibly small - photons have momentum, but not a lot of it.

According to Wikipedia, a solar sail at 1 AU that is 800 meters x 800 meters, would generate about 5N of thrust, or about 55 times what the ion thrusters on the Dawn spacecraft produce, and about 100,000 times as much as the test appears to have measured.

If my math is right based on that, an effectively uni-directional microwave beam of ~17 kW would produce the ~50microNewton's of force they measured.

But hopefully they are aware of radiation pressure and would be accounting for whatever their actual power level is. Otherwise, I don't know why they would invoke vacuum pressure.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/01/2014 09:04 pm
This is the most lucid article I've read on this and at least it doesn't muddle the two up and it contains some additional comment. Half the problem with this story seems to be the muddled reporting of it.

http://www.popsci.com/article/technology/fuel-less-space-drive-may-actually-work-says-nasa?dom=PSC&loc=recent&lnk=5&con=fuelless-space-drive-may-actually-work-says-nasa

It clearly states the device tested was not White's device but it was similar.

It also states they are looking for the results to be peer reviewed.

awesome! Thanks for the link :)
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/01/2014 09:06 pm



Yes. I did a search before I created a new topic but somehow missed the EM drive thread. Doh!
Not sure what to do about it now... Apologies.
It's a thread. the server DB will not self destruct or lag because of it. :) besides normally Forum moderators have authorization to merge threads if it really bugs anyone. i dunno if that is delegated to them here or if it's admin level. it would put extra work on the admins if it hasn't been delegated to moderators though.
Title: Re: EM Drive Developments
Post by: daveklingler on 08/01/2014 09:08 pm
Reading the abstract, Crix seems to be on the right track about quantum mechanics, but I don't know enough to speculate from there what would be happening:

Quote
Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.

However, it appears to me that there is a problem being ignored by the media that are reporting on this:

Quote
Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)

Since one experiment that should NOT have detected thrust did detect thrust, that calls into question whether there was a mistake in the test setup. Since the test chamber was not at a vacuum, I'd call that a very likely source for error. A more promising possibility is it detects thrust in configurations they didn't expect, but the simpler explanation is the former.

Guido Fetta designed one of the test articles to test his theory regarding why the thruster worked.  If his theory was correct, the null test article should not have produced thrust.  Essentially the test invalidated Fetta's theory, but not the test or the test article.  Given that the test took place in August 2013, Brady et al have had plenty of time to determine whether there was a problem in the test jig. 

It would appear that if there is a systematic problem, it's exceedingly subtle.  Four parties (Shawyer, Yang, Fretta, NASA Eagleworks) have found thrust.  As the Eagleworks paper says, "Future test plans include independent verification and validation at other test facilities." 
Title: Re: EM Drive Developments
Post by: Nathan on 08/01/2014 09:22 pm
The nasa link is to an abstract only- it says abstract only available. One presumes the rest of the paper will be available after peer review.
Glad to see this has been investigated.
Title: Re: EM Drive Developments
Post by: GusTurbo on 08/01/2014 09:40 pm
If the null device also produced measurable thrust, then the effect is an artifact, to high confidence. This is the reason for having a null sample. It helps makes sure you're not fooling yourself.

That seems to be the element that most people are missing when they hear about this. The internet is teeming with credulousness about this, and it's a bit alarming.

I think people would do well to have a little skepticism and not view this as being "NASA-approved," just because it has been tested by NASA. For a taste of the reporting on this:

http://sploid.gizmodo.com/nasa-reveals-new-impossible-engine-can-change-space-t-1614549987

Title: Re: EM Drive Developments
Post by: Star One on 08/01/2014 10:35 pm
The nasa link is to an abstract only- it says abstract only available. One presumes the rest of the paper will be available after peer review.
Glad to see this has been investigated.

That would be best. The reporting on this & reaction online in places has been atrocious, it reminds me of the reporting and reaction to both the faster than light neutrinos & ancient gravity waves. The former was an error and the latter has taken a terrible battering under peer review. I'll be interested to see how this gets on with peer review.
Title: Re: EM Drive Developments
Post by: Cherokee43v6 on 08/01/2014 10:38 pm
em-drives, ion engines, VASIMIR, Alcubrier... seem's we have a bazillion ways to go fast on very little fuel once we are up there...  But we still have to deal with the rocket equation to get there in the first place.  I'm waiting to see a /real/ game-changer come along... a provable means of getting out of the gravity well that beats rockets.

Sadly, we are rather lacking in acceptable options there still.
Title: Re: EM Drive Developments
Post by: Star One on 08/01/2014 10:40 pm

em-drives, ion engines, VASIMIR, Alcubrier... seem's we have a bazillion ways to go fast on very little fuel once we are up there...  But we still have to deal with the rocket equation to get there in the first place.  I'm waiting to see a /real/ game-changer come along... a provable means of getting out of the gravity well that beats rockets.

Sadly, we are rather lacking in acceptable options there still.

I think even if the EM thruster actually worked as advertised that it's my understanding you would still need a jet engine for an aircraft or rocket for a spacecraft to get off the ground in the first place.
Title: Re: EM Drive Developments
Post by: Cherokee43v6 on 08/01/2014 10:41 pm

em-drives, ion engines, VASIMIR, Alcubrier... seem's we have a bazillion ways to go fast on very little fuel once we are up there...  But we still have to deal with the rocket equation to get there in the first place.  I'm waiting to see a /real/ game-changer come along... a provable means of getting out of the gravity well that beats rockets.

Sadly, we are rather lacking in acceptable options there still.

I think even if the EM thruster actually worked as advertised that it's my understanding you would still need a jet engine for an aircraft or rocket for a spacecraft to get off the ground in the first place.

Exactly my point.
Title: Re: EM Drive Developments
Post by: Star One on 08/01/2014 10:43 pm
Can I ask as a layman is part of the problem here with anyone analysing this that only an abstract has been published, no doubt because they are waiting peer review?
Title: Re: EM Drive Developments
Post by: CriX on 08/01/2014 11:40 pm
I know very little about this, but it doesn't seem to claim free energy.  Sonny describes the "q thruster" as being essentially like a water propeller, except pushing against vacuum virtual particles.... which sounds plausible... to these foolish ears.  It's definitely disconcerting that even their null device produced "thrust" though.
The end result for these propellantless propulsion devices is free energy, though.

Damnit!  I really want to believe that this is possible.  It seems "fair" that we should be able to spend 2 MegaWatts and get some momentum in exchange.  I hope you've not adequately looked into this.
Title: Re: EM Drive Developments
Post by: brokndodge on 08/02/2014 12:18 am
I'll be interested to see what changes they made to the "null" device and why they believed that those changes would prevent it from producing thrust.
Title: Re: EM Drive Developments
Post by: cuddihy on 08/02/2014 05:18 am
Chris robotbeat's point only holds if you start from the assumption that it can't work. Once you start there, you can then draw your system box in such a way that it excludes the claimed source of momentum/energy. QED you now can call it  'free' energy.
Of course, the argument is a tautology, and it's a way of dismissing the claims on their face by refusing the initial assumptions, but it comes up any time Woodward or White's work are being discussed.

That said, the paper linked clearly says the device constructed to not get results got results anyway, so QED the resonant cavity theory is falsified by this experiment... So not sure why anyone's excited...
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/02/2014 05:23 am
You could use this device to harvest energy from the Universe one way or anoter. But anyway, in my opinion it's at least as bad to violate conservation of momentum.
Title: Re: EM Drive Developments
Post by: Optimistic Brian on 08/02/2014 05:53 am
This is even more exciting than the warp drive research, since if it pans out we could have practical applications almost immediately (i.e., within a couple of years).  No more gravity assists would ever be necessary again.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/02/2014 06:32 am
This is even more exciting than the warp drive research, since if it pans out we could have practical applications almost immediately (i.e., within a couple of years).  No more gravity assists would ever be necessary again.

it is my opinion that because there are at least 5 instances of this general class of scheme that have had positive results that there is something to it.

1. Woodward's version is tested on a torsion balance in a vacuum chamber with atmosphere evacuated. he has shown thrust.
2. This present Shafley resonant cavity thing.
3. the Chinese version of this which was developed from number 2 above because he could not get anyone else interested. they report thiers is ten times as powerful at 100 to 500 mN.
4. Dr Whites QVPT. he has positive results too.
5. the Egyptian Girl's version of this thing. hers uses the dynamic casimir effect. hers is being considered for satellite maneuver and station keeping.
Title: Re: EM Drive Developments
Post by: KelvinZero on 08/02/2014 07:49 am
This is even more exciting than the warp drive research, since if it pans out we could have practical applications almost immediately (i.e., within a couple of years).  No more gravity assists would ever be necessary again.
And free energy.

(*) Propellantless propulsion lets you increase velocity proportional to the energy you put in.
(*) Classical physics lets you extract energy proportional to the velocity squared.

The energy may in fact come from somewhere else. That is fine. What I just do not understand is proponents not admitting to themselves how fundamental a gift this would be.

Alternatively, perhaps this effect is somehow tied to a local reference frame, like pushing against water or solar wind. This would make it far less effective but still would be a vast improvement over the rocket equation. I dont know what would define that frame since I haven't seen any claim that this is the case.

Not investigating these simple aspects with awesome consequences is like not taking your own claim seriously. Similarly with anyone proposing FTL without investigating how the paradoxes would be resolved. If you cannot describe these cases then you cannot describe what you are claiming to have produced.
Title: Re: EM Drive Developments
Post by: QuantumG on 08/02/2014 08:05 am
(*) Propellantless propulsion lets you increase velocity proportional to the energy you put in.

Maybe it doesn't, ya know.
Title: Re: EM Drive Developments
Post by: KelvinZero on 08/02/2014 08:27 am
Perhaps I should have qualified that.. :)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 10:21 am
This is even more exciting than the warp drive research, since if it pans out we could have practical applications almost immediately (i.e., within a couple of years).  No more gravity assists would ever be necessary again.
And free energy.

(*) Propellantless propulsion lets you increase velocity proportional to the energy you put in.
(*) Classical physics lets you extract energy proportional to the velocity squared.

The energy may in fact come from somewhere else. That is fine. What I just do not understand is proponents not admitting to themselves how fundamental a gift this would be.

Alternatively, perhaps this effect is somehow tied to a local reference frame, like pushing against water or solar wind. This would make it far less effective but still would be a vast improvement over the rocket equation. I dont know what would define that frame since I haven't seen any claim that this is the case.

Not investigating these simple aspects with awesome consequences is like not taking your own claim seriously. Similarly with anyone proposing FTL without investigating how the paradoxes would be resolved. If you cannot describe these cases then you cannot describe what you are claiming to have produced.
*If* the effect is real I would speculate (as I have done before in other threads) that the kinetic energy your device gains during operation is always less than the energy input into the device.
This ties the effect to a local reference frame as you state. I would further speculate that this reference frame is the CMB rest frame.
See http://physics.stackexchange.com/questions/25928/is-the-cmb-rest-frame-special-where-does-it-come-from (http://physics.stackexchange.com/questions/25928/is-the-cmb-rest-frame-special-where-does-it-come-from) for a discussion...
Now this is a lot of handwaving and I don't know what mechanism would be involved, but it would address the free-energy objection.
I think  ;)
Title: Re: EM Drive Developments
Post by: KelvinZero on 08/02/2014 10:37 am
Heh.. thats quite cool.. and with a 400km/s relative velocity we should be gaining energy, not expending it at least to begin with.. Just put on the brakes and end up shooting from our solar system at a pretty fair clip!

http://en.wikipedia.org/wiki/Cosmic_microwave_background_radiation#CMBR_dipole_anisotropy

what is in exactly the opposite direction of in the direction of "galactic longitude l = 263.99±0.14°, b = 48.26±0.03°" anyway?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 10:53 am
Not sure if you missed the /sarc tags in the first part of your post.  ::)
"Putting the brakes" on to be at rest wrt the CMB would take the same amount of energy (with caveats due to special relativity) as would accelerating to 400km/s in any direction.
Title: Re: EM Drive Developments
Post by: mboeller on 08/02/2014 11:35 am
first device:  www.emdrive.com
second device:  www.cannae.com

good discussions (2 threads) can be found here, including a lot of links:
http://www.talk-polywell.org/bb/viewforum.php?f=10&sid=3b93a639a0baff9ff89938b7b90beebd
Title: Re: EM Drive Developments
Post by: KelvinZero on 08/02/2014 11:39 am
No sarcasm. I don't understand the method in this thread and as far as I know it has not mentioned pushing on a particular frame, but I am pretty sure you would have to gain energy, or it is a mystery where that energy is going. In any case the important thing is that the amount of energy expended goes up proportional to the square of your current velocity relative to this medium.. otherwise, free energy.

The obvious example is movement in air with a propeller. This is an example of where pushing against some medium is sort of like propellantless propulsion and it would obey the classical velocity squared rule. However you would not have to expend any energy just to come to rest with respect to the air, in fact you could gain energy while doing so. For example you could allow the wind to turn the propeller, generating energy like a windmill and creating drag until your velocity matched that of your surroundings.
Title: Re: EM Drive Developments
Post by: CapitalistOppressor on 08/02/2014 12:05 pm
The abstract just doesn't give enough information.

That said, there appear to have been three items tested on the rig, including an inert object and two test articles, one of which was modified so as not to produce thrust.

The fact that the modified one still produced thrust is a problem.  But we don't know the modifications.  It seems apparent that they were feeding energy into the modified test article.  Otherwise they wouldn't have needed an inert object.

As it is they are saying the inert object did not do anything, while both the engine and modified engine achieved measurable thrust. 

This would maybe make sense if the modifications were to the shape of the container, and were intended to test the theoretical predictions by the inventor. 

There is some supposed theory from the US inventor Guiddo Fetta underlying his Cannae Drive which seem to point to the shape of the container affecting the thrust.  I could see them modifying the shape of the container to test that hypothesis.  If flooding the modified container with microwaves also produced thrust it would mean the shape does not affect the thrust and you have bad theory.  But that doesn't necessarily mean you don't have an effect.

Frankly the seeming violation of conservation of momentum makes it extremely likely that there is an experimental problem.  The fact that the modified engine still produced thrust is a minor issue in comparison.


Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 12:38 pm
Fair comment.
I guess we will have to just see what turns up if they continue to refine the experiments.
Maybe a slim chance of a real, usable effect, but the payoff would be so enormous that it must be worth a fair bit of time, money and effort to either put this to bed for good or confirm it to a high degree of confidence.
Title: Re: EM Drive Developments
Post by: Silversheep2011 on 08/02/2014 01:24 pm
The Wright brothers,
Were two American brothers, inventors, and aviation pioneers who are credited with inventing and building the world's first successful airplane and making the first controlled, powered and sustained heavier-than-air human flight, on December 17, 1903

Prior to that, Some would say that, "Heaver than air was consider impossible". Now it's  considered  common scientific fact...

I think we often have that same Pre-1903 mindset.
 I debated this last year with a 'Doctor of Engineering' at work.
  We disagree when it comes to innovation.
     He says "Impossible is always impossible'

I say:   
 
  "Possible may lead to Possible"         [ if some design works,-  it might work in another application]
 "Impossible might just be Possible "   [ see video 'Fernman Chaser' below -if this rule is used]
  "Possible becomes Impossible"          [Often when we think -of the work and effort involved- a mindset]

So the more we Test, the more we Validate, then the more the,  'Impossible becomes True.'

My acknowledgement to the Wright brothers...

 
Title: Re: EM Drive Developments
Post by: RonM on 08/02/2014 02:07 pm
The first line in the abstract of the technical report is "This paper describes the eight-day August 2013 test campaign designed to investigate and demonstrate viability of using classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the quantum vacuum virtual plasma."

Who knows if this will work, but it is not some magic inertial-less drive that can lead to free energy or perpetual motion. It is an attempt to interact with virtual particles like an electromagnet would interact with an electric field.
Title: Re: EM Drive Developments
Post by: GreenShrike on 08/02/2014 02:21 pm
That said, the paper linked clearly says the device constructed to not get results got results anyway, so QED the resonant cavity theory is falsified by this experiment...

That just means the theory at best requires modification and at worst is a barrel of raw sewage that needs to be dumped and reconsidered entirely.

However, that's how science works -- you experiment to prove or disprove the hypothesis, and when the experiment shows the hypothesis needs to be adjusted, you adjust it and redo the experiment.


So not sure why anyone's excited...

Because anomalous thrust was measured. *Something* caused it. Probably instrument error or an unaccounted for external influence, true, but they still measured it. And until the thrust is explained, there remains the possibility that something unexplained is going on -- and unexplained physics is exciting.

I eagerly await the peer review of the article.
Title: Re: EM Drive Developments
Post by: KelvinZero on 08/02/2014 03:03 pm
The first line in the abstract of the technical report is "This paper describes the eight-day August 2013 test campaign designed to investigate and demonstrate viability of using classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the quantum vacuum virtual plasma."

Who knows if this will work, but it is not some magic inertial-less drive that can lead to free energy or perpetual motion. It is an attempt to interact with virtual particles like an electromagnet would interact with an electric field.
Thats fine, so long as it is understood that if this experiment behaves the same regardless of inertial frame (usually considered a positive for a theory) then it will provide free energy.

Hey! come to think of it, that air example I made above implies we could also get energy for free from the CMB case. In that case it would merely be the good old energy we used to exploit all the time in sailing ships, where you have water and wind moving with different average velocities. We could exploit the difference between the CMB frame and the interstellar medium (say with a minimagnetosphere) or more immediately we could produce energy from a slight drag on the CMB frame, gradually bringing the speed of the planet (and through the slight force of gravity, our sun) to rest WRT to the CMB. The mass of the sun and 400km/s is a massive store of energy.
Title: Re: EM Drive Developments
Post by: Scylla on 08/02/2014 03:19 pm
Why do I keep seeing reference to "free energy". Am I misunderstanding the meaning of it's use in theses posts?

Even if the device works, you have to introduce energy (microwaves) to make it work.

TANSTAAFL
Title: Re: EM Drive Developments
Post by: Prober on 08/02/2014 03:55 pm
Fair comment.
I guess we will have to just see what turns up if they continue to refine the experiments.
Maybe a slim chance of a real, usable effect, but the payoff would be so enormous that it must be worth a fair bit of time, money and effort to either put this to bed for good or confirm it to a high degree of confidence.

agreed, how bout we package up a working unit and move it up to the ISS for a real test.  We don't have time to waste when it comes to using the LEO Space Lab that's available now.
Title: Re: EM Drive Developments
Post by: cuddihy on 08/02/2014 03:56 pm
What the free energy folks are saying is that if you assume a) that the device provides thrust at a constant or linear rate based on energy input and b) that this assumption holds with no changes at different velocites then c) since kinetetic energy increases at the rate of velocity squared, you are getting an exponential increase in KE for a linear or constant input in Electrical energy. Ie, "free" energy is the delta between KE out and EE in.

What this thesis ignores is that none of these theories extend how their devices would function as velocity increases. Whether they interact with virtual particles or far-off active matter, none of the theories speculate about how "coupling" occurs. So the thesis is pointing out an incongruity in an extension of the theory being tested that goes well beyond what the theory currently proposes...it's a scientific strawman attack.
Title: Re: EM Drive Developments
Post by: RonM on 08/02/2014 04:10 pm
The first line in the abstract of the technical report is "This paper describes the eight-day August 2013 test campaign designed to investigate and demonstrate viability of using classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the quantum vacuum virtual plasma."

Who knows if this will work, but it is not some magic inertial-less drive that can lead to free energy or perpetual motion. It is an attempt to interact with virtual particles like an electromagnet would interact with an electric field.
Thats fine, so long as it is understood that if this experiment behaves the same regardless of inertial frame (usually considered a positive for a theory) then it will provide free energy.

Hey! come to think of it, that air example I made above implies we could also get energy for free from the CMB case. In that case it would merely be the good old energy we used to exploit all the time in sailing ships, where you have water and wind moving with different average velocities. We could exploit the difference between the CMB frame and the interstellar medium (say with a minimagnetosphere) or more immediately we could produce energy from a slight drag on the CMB frame, gradually bringing the speed of the planet (and through the slight force of gravity, our sun) to rest WRT to the CMB. The mass of the sun and 400km/s is a massive store of energy.

What are you talking about? Their concept is a magnetoplasmadynamic thruster that uses virtual particles as the plasma. Okay, that does sounds far fetched, but you can't get free energy from it. While at first glance it seems like a reactionless drive, it is not because the virtual particles are the reaction mass. KE would still increase at the rate of velocity squared.

http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster (http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster)
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/02/2014 04:17 pm
It's not a scientific strawman. It's a valid criticism. Propellantless thrust already requires new physics. Also, all of the excitement over applications basically assume that what KelvinZero is saying is true.
Title: Re: EM Drive Developments
Post by: A_M_Swallow on 08/02/2014 04:26 pm
You could use this device to harvest energy from the Universe one way or anoter. But anyway, in my opinion it's at least as bad to violate conservation of momentum.

To break conservation of momentum you have to show that the entire planet Earth was not moved in the opposite direction.  If something as simple as walking can move the Earth then very accurate strain gauges would need attaching to the vacuum chamber to check this.
Title: Re: EM Drive Developments
Post by: KelvinZero on 08/02/2014 04:32 pm
It's not a scientific strawman. It's a valid criticism. Propellantless thrust already requires new physics. Also, all of the excitement over applications basically assume that what KelvinZero is saying is true.

Wouldn't it be cool though.. apart from the possible world ending, Fermi paradox solving bit ;)

Actually Im still trying to get my head around this thing that IslandPlaya brought up:
http://en.wikipedia.org/wiki/Cosmic_microwave_background#CMBR_dipole_anisotropy

That might knock a hole in my favorite FTL paradox also.
Title: Re: EM Drive Developments
Post by: cuddihy on 08/02/2014 04:47 pm
It's not a scientific strawman. It's a valid criticism. Propellantless thrust already requires new physics. Also, all of the excitement over applications basically assume that what KelvinZero is saying is true.

Non sequitur. All physics not previously widely accepted is "new physics."

And it does not follow that because "anomalous thrust produced", or even "can change an object's momentum without expelling mass" that therefore "must require linear input of energy for linear increase in velocity".
Title: Re: EM Drive Developments
Post by: Prober on 08/02/2014 05:25 pm
Looks like the media has picked up on it.

NASA confirms ‘impossible’ thruster actually works, could revolutionize space travel

Read more: http://www.digitaltrends.com/cool-tech/nasa-confirms-impossible-space-drive-actually-works-revolutionize-space-travel/#ixzz39FyGJbBH
Follow us: @digitaltrends on Twitter | digitaltrendsftw on Facebook

Title: Re: EM Drive Developments
Post by: Robotbeat on 08/02/2014 05:53 pm
...powered by wishful thinking.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/02/2014 06:04 pm

em-drives, ion engines, VASIMIR, Alcubrier... seem's we have a bazillion ways to go fast on very little fuel once we are up there...  But we still have to deal with the rocket equation to get there in the first place.  I'm waiting to see a /real/ game-changer come along... a provable means of getting out of the gravity well that beats rockets.

Sadly, we are rather lacking in acceptable options there still.

I think even if the EM thruster actually worked as advertised that it's my understanding you would still need a jet engine for an aircraft or rocket for a spacecraft to get off the ground in the first place.

sure we are dealing with micro newtons now... but Dr White's 2013 symposium talk extrapolated to extraordinary levels thrust for trips to Jupiter and points beyond ...all the way to the tau point if i recall correctly. his device is a different make and model but the QVPT does the same sort of thing as this generally using the same mechanism of operation in broad terms.

talk is here. the first portion of the talk is on QVPT and he hits all around but not in his classified results too.

EDIT: looks like i have the wrong vid. this is mostly about his warp drive. i will make a separate post when i find the proper video. Sorry, guys.


Title: Re: EM Drive Developments
Post by: Danderman on 08/02/2014 06:41 pm
I would lay my money on instrument error. 

I would also lay money on nothing substantive coming out of this, much like cold fusion, where adherents claiming that progress is being made secretly, but no real world applications after 25 years.

Title: Re: EM Drive Developments
Post by: SteveKelsey on 08/02/2014 06:46 pm
I step into this debate with trepidation. My perspective is that neither proponent has developed a successful characterisation of any effect, hence the confusion over the test article modified to not perform, and the confusion over Shawyer's description leading to his theory gaining little traction. However- having exercised my doubts, and well aware of the problems inherent in using an analogy, one presents itself to me in this case. A rocket motor utilises the shape of the nozzle to convert chemical energy to a directed force, which we call thrust. Is it possible that all that happening here is microwave energy is converted to thrust by the shape of the chamber?
It's a horribly inefficient conversion that may be due to the net sum of all the forces applied of the chamber. It is most likely more complex and as I am not clear on Shawyer's use of relativity as part of his description of the system I am ignoring that, but from what I have read I am in good company. Just an idle thought on a rainy saturday evening in Cumbria so if you think it doesn't hold water let it pass         : )
Title: Re: EM Drive Developments
Post by: SteveKelsey on 08/02/2014 06:49 pm
Unfortunately there are no real world applications for any fusion system to date.
Title: Re: EM Drive Developments
Post by: CW on 08/02/2014 07:39 pm
Hello all,

I think there is one elephant in the room that nobody seems to notice. If the drive is supposed to gain impulse by interaction with virtual particles of the quantum vacuum, then these particles obviously have to be accelerated in the opposed direction in which the drive is accelerated.

Here comes now the elephant: When those accelerated virtual particles (which pop in an out of existence spontaneously) disappear again to who-knows-where, what happens to the impulse that these particles previously gained.. is it gone? I can hardly imagine that this should be the case. So.. where would the imparted impulse on the virtual particles go? Ideas? On the other hand.. please correct me if I'm wrong.. I seem to remember some knowledge that virtual particles were not subject to impulse conservation?

Regards
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 07:47 pm
I step into this debate with trepidation. My perspective is that neither proponent has developed a successful characterisation of any effect, hence the confusion over the test article modified to not perform, and the confusion over Shawyer's description leading to his theory gaining little traction. However- having exercised my doubts, and well aware of the problems inherent in using an analogy, one presents itself to me in this case. A rocket motor utilises the shape of the nozzle to convert chemical energy to a directed force, which we call thrust. Is it possible that all that happening here is microwave energy is converted to thrust by the shape of the chamber?
It's a horribly inefficient conversion that may be due to the net sum of all the forces applied of the chamber. It is most likely more complex and as I am not clear on Shawyer's use of relativity as part of his description of the system I am ignoring that, but from what I have read I am in good company. Just an idle thought on a rainy saturday evening in Cumbria so if you think it doesn't hold water let it pass         : )
We are a friendly bunch here SteveKelsey, never be afraid to put your oar in!  :)
IMHO a good post! I am unclear on almost all of the theory that predicts the way these things should work. Doesn't stop me spouting my speculations though!
It can't however work like you are suggesting. The microwave cavity is closed. Imagine a Merlin engine encased in a large metal sphere. Would it go anywhere when ignited? No.
It's a rainy and windy Saturday night up here in the Outer Hebs too! But what better way to pass some time than talking about possibly world changing tech.
 ;D
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 07:57 pm
Hello all,

I think there is one elephant in the room that nobody seems to notice. If the drive is supposed to gain impulse by interaction with virtual particles of the quantum vacuum, then these particles obviously have to be accelerated in the opposed direction in which the drive is accelerated.

Here comes now the elephant: When those accelerated virtual particles (which pop in an out of existence spontaneously) disappear again to who-knows-where, what happens to the impulse that these particles previously gained.. is it gone? I can hardly imagine that this should be the case. So.. where would the imparted impulse on the virtual particles go? Ideas? On the other hand.. please correct me if I'm wrong.. I seem to remember some knowledge that virtual particles were not subject to impulse conservation?

Regards
Welcome to the forum!
Short answer. I don't know. I don't think anyone knows...
Interesting point of discussion though! Great first post mate!
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/02/2014 07:59 pm
The Wright brothers,
Were two American brothers, inventors, and aviation pioneers who are credited with inventing and building the world's first successful airplane and making the first controlled, powered and sustained heavier-than-air human flight, on December 17, 1903

Prior to that, It could be said that, "Heaver than air was consider impossible".

That's completely wrong.  Since the start of modern physics in the era of Newton, no serious physicist thought heavier than air flight violated the laws of physics.  It was always considered an engineering challenge, not a violation of the laws of physics.

The scientific community is far smarter than your fantasies imagine it to be.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 08:12 pm
Consider a neutron in free space. It is surrounded by a malestrom of pair-production events all around it. It is perturbed on the Planck scale by all these events, but as in Brownian motion they average out to nearly zero.
Remember we are talking Planck scale perturbations here. I.e: un-observable.
What if you could bias the pair-production events somehow so that there was a preferred vector of momentum?
Would we see our neutron being accelerated in a particular direction?
 ;)
Title: Re: EM Drive Developments
Post by: CW on 08/02/2014 08:18 pm
Consider a neutron in free space. It is surrounded by a malestrom of pair-production events all around it. It is perturbed on the Planck scale by all these events, but as in Brownian motion they average out to nearly zero.
Remember we are talking Planck scale perturbations here. I.e: un-observable.
What if you could bias the pair-production events somehow so that there was a preferred vector of momentum?
Would we see our neutron being accelerated in a particular direction?
 ;)

Since neutrons can't be accelerated by electromagnetism AFAIK, this effect would sound similar to what gravity would be able to do. I mean, gravity is a gradient in space, right?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 08:23 pm
Consider a neutron in free space. It is surrounded by a malestrom of pair-production events all around it. It is perturbed on the Planck scale by all these events, but as in Brownian motion they average out to nearly zero.
Remember we are talking Planck scale perturbations here. I.e: un-observable.
What if you could bias the pair-production events somehow so that there was a preferred vector of momentum?
Would we see our neutron being accelerated in a particular direction?
 ;)

Since neutrons can't be accelerated by electromagnetism AFAIK, this effect would sound similar to what gravity would be able to do. I mean, gravity is a gradient in space, right?
I'm not talking about EM acceleration, hence my choice of the neutron to make things clear.
I'm talking about pair-production in the false vacuum being able to transfer momentum along a particular vector, under conditions that are created by the device we are discussing.
Title: Re: EM Drive Developments
Post by: CW on 08/02/2014 08:29 pm
So you mean that by some mechanism, the maelstrom of vectors in quantum vacuum, which usually time average to zero, change locally in the drive to produce a non-zero vector in the preferred direction? Like some sort of mechanism to manipulate the "natural statistics" of space? :)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 08:31 pm
Yes. I suppose that is exactly what I'm saying.
Sounds crazy when you put it like that! I'm just putting forward ways the anomalous thrust could be explained *if* it is real...
Title: Re: EM Drive Developments
Post by: Star One on 08/02/2014 08:33 pm
Slightly odd article from the Verge on this. What I mean is they seem to be sceptical about this because of Guido Fetta's qualifications, which is a bit harsh.

http://www.theverge.com/2014/8/1/5959637/nasa-cannae-drive-tests-have-promising-results
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 08:44 pm
Slightly odd article from the Verge on this. What I mean is they seem to be sceptical about this because of Guido Fetta's qualifications, which is a bit harsh.

http://www.theverge.com/2014/8/1/5959637/nasa-cannae-drive-tests-have-promising-results
We see this everyday.
People who criticize CAGW are hacked down because the are not in the 'Climate Science Club' and don't have qualifications in 'Climate Science' (sic)
In this case 'He can't possibly know what he is talking about, he only knows about chemistry!'
Sigh.
Maybe the tech doesn't work, but I would fight and fight for the ability of people to try and fail at this sort of stuff.
/rant over
Title: Re: EM Drive Developments
Post by: RonM on 08/02/2014 08:50 pm
Yes. I suppose that is exactly what I'm saying.
Sounds crazy when you put it like that! I'm just putting forward ways the anomalous thrust could be explained *if* it is real...

It does sound crazy, but it is worth a little testing. If we don't test theory to see if it works, then it becomes philosophy.

Odds are the anomalous thrust produced is just experimental error. They'll find out as they do more testing.
Title: Re: EM Drive Developments
Post by: CW on 08/02/2014 09:02 pm
Yes. I suppose that is exactly what I'm saying.
Sounds crazy when you put it like that! I'm just putting forward ways the anomalous thrust could be explained *if* it is real...

OK, here's an idea. The resonant cavity's purpose is to produce standing waves, right? So, basically it's a precise arrangement of conducting plates which reflect EM waves back and forth. For some reason, this reminds me of a "macro" Casimir cavity, just on a different scale and with "real" photons. So, what if.. this EM drive acted (by coincidence) as some weird form of "macro" Casimir cavity and its specific shape (accidentally) produced a preferred vector, working with real photons? I seem to remember that specific geometries of Casimir cavities were calculated to be able to produce a preferred vector of motion. I didn't find that piece of info yet again, or perhaps I remember wrongly. Maybe someone else knows better?
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/02/2014 09:15 pm
Slightly odd article from the Verge on this. What I mean is they seem to be sceptical about this because of Guido Fetta's qualifications, which is a bit harsh.

http://www.theverge.com/2014/8/1/5959637/nasa-cannae-drive-tests-have-promising-results
We see this everyday.
People who criticize CAGW are hacked down because the are not in the 'Climate Science Club' and don't have qualifications in 'Climate Science' (sic)
In this case 'He can't possibly know what he is talking about, he only knows about chemistry!'
Sigh.
Maybe the tech doesn't work, but I would fight and fight for the ability of people to try and fail at this sort of stuff.
/rant over

Nobody I've ever heard of has argued that anybody shouldn't have the right to try whatever they want, with their own resources, and the resources of anyone wishing to spend them that way.

However, resources are limited, and it's perfectly legitimate to argue about whether a particular line of research is worth putting the resources into, and to try to convince others not to put their own resources into a particular line of research.

There are tens of thousands of grad students struggling to find research dollars to continue their research into all sorts of topics in physics and aerospace engineering.

I personally find it sad that a very small number of fringe people who make outlandish claims get so much attention -- attention that, to my mind, would be better focused on more mainstream science and engineering, which is, I believe, far more likely to get us eventually to the breakthroughs we all would like to see.

Real advances in science come from careful experimentation and analysis, the discovery of anomalous results, and the advancement of theories to explain those results, without any particular engineering goal in mind.  Deciding to try to design a device that violates limitations of known physics gets it backwards -- it's the approach of amateurs.
Title: Re: EM Drive Developments
Post by: Star One on 08/02/2014 09:21 pm
Slightly odd article from the Verge on this. What I mean is they seem to be sceptical about this because of Guido Fetta's qualifications, which is a bit harsh.

http://www.theverge.com/2014/8/1/5959637/nasa-cannae-drive-tests-have-promising-results
We see this everyday.
People who criticize CAGW are hacked down because the are not in the 'Climate Science Club' and don't have qualifications in 'Climate Science' (sic)
In this case 'He can't possibly know what he is talking about, he only knows about chemistry!'
Sigh.
Maybe the tech doesn't work, but I would fight and fight for the ability of people to try and fail at this sort of stuff.
/rant over

Nobody I've ever heard of has argued that anybody shouldn't have the right to try whatever they want, with their own resources, and the resources of anyone wishing to spend them that way.

However, resources are limited, and it's perfectly legitimate to argue about whether a particular line of research is worth putting the resources into, and to try to convince others not to put their own resources into a particular line of research.

There are tens of thousands of grad students struggling to find research dollars to continue their research into all sorts of topics in physics and aerospace engineering.

I personally find it sad that a very small number of fringe people who make outlandish claims get so much attention -- attention that, to my mind, would be better focused on more mainstream science and engineering, which is, I believe, far more likely to get us eventually to the breakthroughs we all would like to see.

Real advances in science come from careful experimentation and analysis, the discovery of anomalous results, and the advancement of theories to explain those results, without any particular engineering goal in mind.  Deciding to try to design a device that violates limitations of known physics gets it backwards -- it's the approach of amateurs.

You might want to be rather careful in what you say here otherwise it might look like you're casting aspersions on the NASA scientists and their decision to investigate this.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 09:57 pm
Yes. I suppose that is exactly what I'm saying.
Sounds crazy when you put it like that! I'm just putting forward ways the anomalous thrust could be explained *if* it is real...

OK, here's an idea. The resonant cavity's purpose is to produce standing waves, right? So, basically it's a precise arrangement of conducting plates which reflect EM waves back and forth. For some reason, this reminds me of a "macro" Casimir cavity, just on a different scale and with "real" photons. So, what if.. this EM drive acted (by coincidence) as some weird form of "macro" Casimir cavity and its specific shape (accidentally) produced a preferred vector, working with real photons? I seem to remember that specific geometries of Casimir cavities were calculated to be able to produce a preferred vector of motion. I didn't find that piece of info yet again, or perhaps I remember wrongly. Maybe someone else knows better?
I like this idea. What we are seeing is a macro-Casimir effect. Maybe like we see macro superconductivity from quantam Cooper-pairings?
Who knows?
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/02/2014 10:00 pm
You might want to be rather careful in what you say here otherwise it might look like you're casting aspersions on the NASA scientists and their decision to investigate this.

This is one little corner of NASA.  NASA is a huge organization with lots and lots of people working on lots of things.  Sonny White and friends are not equivalent to NASA as a whole.

And there's nothing wrong with complaining that this one small part of NASA is wasting precious resources that could be better spent, and misleading the public by letting the NASA name get attached to wishful thinking in the guise of science.
Title: Re: EM Drive Developments
Post by: Star One on 08/02/2014 10:12 pm
You might want to be rather careful in what you say here otherwise it might look like you're casting aspersions on the NASA scientists and their decision to investigate this.

This is one little corner of NASA.  NASA is a huge organization with lots and lots of people working on lots of things.  Sonny White and friends are not equivalent to NASA as a whole.

And there's nothing wrong with complaining that this one small part of NASA is wasting precious resources that could be better spent, and misleading the public by letting the NASA name get attached to wishful thinking in the guise of science.

I like the way you're pre-judging the outcome of this, now that's not very scientific. Such attitudes are almost as bad in my book as the pseudo-science that often attaches itself online too such pronouncements.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 10:13 pm
Real advances in science come from careful experimentation and analysis, the discovery of anomalous results, and the advancement of theories to explain those results, without any particular engineering goal in mind.
Which is exactly what the authors are trying to do.
Title: Re: EM Drive Developments
Post by: Star One on 08/02/2014 10:15 pm

Real advances in science come from careful experimentation and analysis, the discovery of anomalous results, and the advancement of theories to explain those results, without any particular engineering goal in mind.
Which is exactly what the authors are trying to do.

That point seems to have escaped the OP.
Title: Re: EM Drive Developments
Post by: CW on 08/02/2014 10:43 pm
Coming back to the issue of the virtual particle pairs of quantum space possibly being used for propulsion and seemingly vanishing impulse in this setup, when the pairs disappear again into "nothingness".. something interesting might happen, if this is not all a systematic measuring error.

So here comes another idea. If we were to consider quantum space itself to be made up of virtual particle pairs et cetera and made an analogy of quantum space being some sort of weird virtual liquid or gas with the particle pairs as 'liquid' or 'gas' molecules/atoms (or maybe even being a perfect virtual plasma e.g. of electrons and positrons etc), a space drive using a technologically enabled, controlled particle pair interaction to 'push' against this 'substance' should logically result in creating a sort of particle pair 'stream' exiting the space drive in the opposed direction to the drive's acceleration, to keep impulse conservation intact. That would be analogous to a submarine using propellers to push water backwards, while itself is propelled forward.

Now, if we considered quantum space as a medium to be 'expelled' behind the drive, wouldn't that imply quantum space itself were being moved? And what would happen, if that moving 'medium' hits on some other object. Would there be some 'virtual particle wind or stream' behind the drive's vector of acceleration, as can be observed in water for submarines?

Questions over questions :) .
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/02/2014 11:01 pm
Real advances in science come from careful experimentation and analysis, the discovery of anomalous results, and the advancement of theories to explain those results, without any particular engineering goal in mind.
Which is exactly what the authors are trying to do.

You're missing my point.  Looking around randomly for anomalies isn't a very good strategy.  Neither is designing a device based on a misunderstanding of known physics to see if it happens to work.  There are better places to choose to look for anomalies.

You also missed the "careful" point.  Sonny White and friends have a long history of claims based on experimental setups that have been criticized as poorly controlled.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/02/2014 11:05 pm

Real advances in science come from careful experimentation and analysis, the discovery of anomalous results, and the advancement of theories to explain those results, without any particular engineering goal in mind.
Which is exactly what the authors are trying to do.

That point seems to have escaped the OP.

The point that escaped you is the part where I said "without any particular engineering goal in mind".

Having a goal of making a reactionless drive and then looking for physics to make it work is backwards.  That's not how discoveries in physics are made.  They are made by not having any preconceived ideas about applications.
Title: Re: EM Drive Developments
Post by: frobnicat on 08/02/2014 11:14 pm
Is there theoretical limits to how high the Q factor of a resonant cavity can go ? If constant thrust necessitates constant power above some threshold, then "propellentless propulsion" doesn't really escape the rocket equation because of mass energy equivalence : all the energy put into the engine must come at the price of "burned" mass. A photon engine is a well understood example of changing "object's momentum without expelling mass" as photons have no rest mass, but they require energy (burning fuel mass) to be created... How the proposal would be better than a photon rocket ?
If the hypothetical thrust effect is limited to be small enough compared to the required power, then even a constant thrust (not depending on speed) at constant power doesn't imply "free energy" as the ship would bleed enough mass flow in the conversion to the required power to maybe equal but not beat a perfect physically respectable photon rocket. Granted, at slower speeds the ability to efficiently "push" on space or whatever without expelling reaction mass would be convenient as a few percent of mass of energy fuel only is lost in the process and the (non relativistic part of) rocket equation kind of vanishes...
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 11:25 pm
As far as I know there are no theoretical limits on the Q factor in a superconducting cavity.
Practical limits is another thing entirely of course...
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 11:33 pm
I have not seen 'free energy' mentioned for quite a few posts now.
Thank you all for your reasoned ideas. Much to sleep on...
Another thought, although it may seem to make me more of kook than some people already think...
If this effect was real, do you think we would hear anything true about it? The military would be all over it like a rash...
Just a thought.
Title: Re: EM Drive Developments
Post by: Silversheep2011 on 08/02/2014 11:35 pm
They are made by not having any preconceived ideas about applications.

How do you look for a new law in physics?

A friend shared this with me. It makes the point well.
and Visa versa

https://www.youtube.com/watch?v=b240PGCMwV0&feature=player_embedded
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/02/2014 11:43 pm
Having a goal of making a reactionless rocket drive and then looking for physics to make it work is backwards.  That's not how discoveries in physics are made.  They are made by not having any preconceived ideas about applications.
Strikethru mine.
Do you see how silly this sounds?
Title: Re: EM Drive Developments
Post by: CW on 08/02/2014 11:44 pm
If I'm not mistaken, the magnetic field strength that a superconductor is subjected to externally, has a well-defined upper limit, before superconductivity breaks down. So I'm a bit worried that there's only a certain amount of photons that can be within such a cavity at any given instant in time, due to the magnetic field component of the photons possibly impinging on the surface of the superconductor at the same time. Or perhaps that is no problem at all, maybe someone can elaborate on behavior of superconductor and photon interaction.

IMHO the charm of a working EM drive would be that, in the best case, it would become possible to create ultra-high Q cavities (minimal losses), pump them full of photons and let the device counteract 1:1 Earth's gravity for all kinds of transportation purposes with small energy requirements. I'm not so sure if space travel were the most prominent application of such a device. But who knows.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/03/2014 12:44 am
Having a goal of making a reactionless rocket drive and then looking for physics to make it work is backwards.  That's not how discoveries in physics are made.  They are made by not having any preconceived ideas about applications.
Strikethru mine.
Do you see how silly this sounds?

No, it's not silly when you replace the word "reactionless" with "rocket".

You are still missing my point.  My point is that physics and engineering are two different things.  When you go to do engineering, you come up with a device you would like to create, and you use known physics to create it.  You you do physics, you don't start with an engineering problem you'd like to solve, you start by looking for what part of the experimental envelope of the behavior of the world hasn't been adequately explored, and you start exploring it.  Trying to find new physics by doing engineering is foolish.

Physics is about discovering what the truth of the universe as it already exists is.  Engineering is about using the knowledge from physics to make changes in the universe.  The approaches to the two subjects that yield best results are very different.
Title: Re: EM Drive Developments
Post by: mlindner on 08/03/2014 01:54 am
The fact that this article is even being considered by NSF members has me seriously worried about the future of American technological might.

Have we really gotten to the point that something akin to free energy generation that quackpots trot around on youtube with has gotten smart people this confused?

This technology has fraud written all over it. The creator will profit monetarily if it succeeds. He only agrees to let you test it if you agree that his theories are correct. The test device itself was built by the creator. The NEGATIVE test device showed positive results, thus completely invalidating the test. The effects of atmosphere were not removed from the testing chamber. The effects of outgassing and mass loss were not accounted for. The AIAA paper in question only has two references, one to the creator's website and one to the other faulty Chinese test.

This is terrible all over. The world is being given the runaround by this guy.

http://arstechnica.com/science/2014/08/dont-buy-stock-in-impossible-space-drives-just-yet/

Direct link to the pdf (this won't work unless your univeristy/company has a subscription). http://arc.aiaa.org/doi/pdf/10.2514/6.2014-4029
Title: Re: EM Drive Developments
Post by: mlindner on 08/03/2014 02:09 am
This is even more exciting than the warp drive research, since if it pans out we could have practical applications almost immediately (i.e., within a couple of years).  No more gravity assists would ever be necessary again.
And free energy.

(*) Propellantless propulsion lets you increase velocity proportional to the energy you put in.
(*) Classical physics lets you extract energy proportional to the velocity squared.

Wow that's a perfect way to debunk this. I was looking for something short and sweet like this.
Title: Re: EM Drive Developments
Post by: cuddihy on 08/03/2014 02:55 am
This is even more exciting than the warp drive research, since if it pans out we could have practical applications almost immediately (i.e., within a couple of years).  No more gravity assists would ever be necessary again.
And free energy.

(*) Propellantless propulsion lets you increase velocity proportional to the energy you put in.
(*) Classical physics lets you extract energy proportional to the velocity squared.

Wow that's a perfect way to debunk this. I was looking for something short and sweet like this.

[facepalm]
Brevity is the soul of wit...and a close companion of confirmation bias, apparently.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/03/2014 03:22 am
This is even more exciting than the warp drive research, since if it pans out we could have practical applications almost immediately (i.e., within a couple of years).  No more gravity assists would ever be necessary again.
And free energy.

(*) Propellantless propulsion lets you increase velocity proportional to the energy you put in.
(*) Classical physics lets you extract energy proportional to the velocity squared.

Wow that's a perfect way to debunk this. I was looking for something short and sweet like this.

yesh. you wouldn't want to try to find out where the unexpected energy comes from or something all scientific like. here is the issue with that. random debunking is bunkum. whatever the root cause of a phenomenon whether valid or not you just say it's swamp gas. it does not really explain what happened. it's every bit as much bunk as claiming it's Klaatu.
Title: Re: EM Drive Developments
Post by: mlindner on 08/03/2014 03:31 am
This is even more exciting than the warp drive research, since if it pans out we could have practical applications almost immediately (i.e., within a couple of years).  No more gravity assists would ever be necessary again.
And free energy.

(*) Propellantless propulsion lets you increase velocity proportional to the energy you put in.
(*) Classical physics lets you extract energy proportional to the velocity squared.

Wow that's a perfect way to debunk this. I was looking for something short and sweet like this.

yesh. you wouldn't want to try to find out where the unexpected energy comes from or something all scientific like. here is the issue with that. random debunking is bunkum. whatever the root cause of a phenomenon whether valid or not you just say it's swamp gas. it does not really explain what happened. it's every bit as much bunk as claiming it's Klaatu.

I'm all for using science to attempt to validate the claims. See my previous post. I want to see a proper experiment done with a proper negative test that demonstrates non-action and a proper test that accounts for variables of mass loss from evaporation/outgassing and proper testing in a vacuum to cancel out effects of movements of the atmosphere. I'll not believe an ounce of this until we get those minimum of tests done. After that some peer verification and tests by non-interested parties (namely parties that won't make money from the success) would be good as well.

I was mainly looking for a short description of a major issue with the experiment that I can feed to people to prompt them to engage their brains for a minute rather than shoveling the bull**** down their throats without thinking. After that some discussion can be sparked to realize the issues at hand.
Title: Re: EM Drive Developments
Post by: KelvinZero on 08/03/2014 04:10 am
I have not seen 'free energy' mentioned for quite a few posts now.
Yeah.. I was thinking it isn't really appropriate to keep explaining this repeatedly in specific versions propellantless thrust threads. It does sort of derail the thread, which should only concern it self with explaining how it works around this particular well known issue. But everyone should understand what the issue is.

I liked your CMB suggestion, because then we can at least discuss how it behaves in particular circumstances. This is hugely powerful. The moment you start looking at a useful description of how it behaves whole new unexpected behavior can be discovered, such as extracting energy from the difference in velocity of the solar system and the CMB frame.. the existence of which still boggles my mind a bit.

If the theory is correct yet is not obvious to the thousands of physicists out there who are brighter than I, then obviously it will be beyond my understanding. I would just like to understand the claim to the level of a science fiction writer, so I could describe what it actually means to my fledgling galactic citizen.

I think rather than repeating these over and over, we should have a general thread and just refer to it. Im hoping other people will add their favorite paradox examples also.
..General explanation here...
Everyone should understand the issue, and then threads like this can just focus on how this version claims to get around it.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/03/2014 04:38 am


I was mainly looking for a short description of a major issue with the experiment that I can feed to people to prompt them to engage their brains for a minute rather than shoveling the bull**** down their throats without thinking. After that some discussion can be sparked to realize the issues at hand.

i think there are two major issues.

1. the signal is very small. this makes it easy for uncontrolled for unanticipated spurious signals to get in there. critic can claim this is what caused it all day long. it's hard to disprove.

2. in this experiment it appears the control test article got the same signal. I do not think this is as damning as it could be because of the signals found by other researchers with (similar devices of differing design details.)  E.G. Dr Woodward's design is a solid state peizoelectric stack. he gets a thrust signal. Dr White has a capacitor and coil ring and gets thrust signals. the Egyptian girl uses a moving casimir mirror and gets a thrust signal. The Chinese use Shayer's design as a starting point and get a much stronger thrust signal than he did or NASA testing got.
Title: Re: EM Drive Developments
Post by: FlyingMoose on 08/03/2014 04:43 am
The EmDrive and White's theories are the opposite -- they put the theory first and then go looking for evidence afterwards.  In both cases, the theories claim to be consequences of existing theories in physics, but reputable physicists say that in fact they come from misunderstandings of current theories.

That is incorrect.  This discovery came about because Shawyer was trying to explain the thrust generated by the microwave transmitters on satellites which exceeded what was expected and required additional fuel to correct.
Title: Re: EM Drive Developments
Post by: FlyingMoose on 08/03/2014 05:46 am
(*) Propellantless propulsion lets you increase velocity proportional to the energy you put in.

How is this any different from an ion thruster?

If you do one burn to bring a satellite up to 10 m/s, and then another with the same energy that brings it to 20 m/s, you have the same phenomenon.  In the second burn, you get more kinetic energy than in the first burn, even though your thruster expended the same amount of energy.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/03/2014 05:52 am
(*) Propellantless propulsion lets you increase velocity proportional to the energy you put in.

How is this any different from an ion thruster?

If you do one burn to bring a satellite up to 10 m/s, and then another with the same energy that brings it to 20 m/s, you have the same phenomenon.  In the second burn, you get more kinetic energy than in the first burn, even though your thruster expended the same amount of energy.

The difference is that with the ion thruster you had to put in more energy for the first 10 m/s because you had to accelerate both the satellite and the propellant you're going to use for the second burn.  You can think of it as the propellant for the second burn already having a bunch of kinetic energy from the first burn and you're using both that kinetic energy already in the prop plus the electric energy of the thruster to get the second 10 m/s of delta-v.
Title: Re: EM Drive Developments
Post by: MP99 on 08/03/2014 06:34 am


What this thesis ignores is that none of these theories extend how their devices would function as velocity increases.

[quote name="RonM" post=1237898 timestamp=1406988473]propulsive momentum transfer via the quantum vacuum virtual plasma." [/quote]

Surely, interactions with the quantum vacuum should be unaffected by your velocity - you can always see a "version" of the vacuum as if you are currently at rest?

Cheers, Martin
Title: Re: EM Drive Developments
Post by: pagheca on 08/03/2014 07:01 am
I wouldn't dream of posting here....
I can understand the skepticism...
However the experimenters are all NASA scientists.
What is the problem? are you a better scientist John F? Or do you think the authors should be stripped of their NASA posts?
Maybe we should calm down and investigate further?
Heavens!

The problem is that the article linked is not a scientific paper (http://www.compoundchem.com/2014/04/02/a-rough-guide-to-spotting-bad-science), but a clearly preliminary technical report, the typical "hat on the seat" (copyrighted by me :) ) paper required to ensure to be the first IF a sensational result is confirmed in order to get an high citation index in the future.

(1) There has been no submission to refereed journals as for the standard scientific procedure.

(2) No details about the experimental setup have been given. So, it is impossible to submit the paper to a check, or to repeat the experiment to check for eventual involuntary errors by the scientists.

(3) there is the detail of thrust measured also in the "null" test article, that was unexpected and suggest there is a bias somewhere in the measuring system.

I would suspend any judgement till a proper paper is submitted to a proper journal. However, let me remind that extraordinary claims require extraordinary evidences, that is not the case here.

p.s. I had no time to read all the thread. So, apologies if there are other papers confirming the results. I refer just to one linked at the beginning of the thread, that is also the one linked to the digitaltrend article.
Title: Re: EM Drive Developments
Post by: Silversheep2011 on 08/03/2014 07:22 am

This discovery came about because Shawyer was trying to explain the thrust generated by the microwave transmitters on satellites which exceeded what was expected and required additional fuel to correct.

This would really make an interesting subject to read or a comparison point to read up on.
who you be able to supply a link or a paper?
Title: Re: EM Drive Developments
Post by: john smith 19 on 08/03/2014 07:41 am
OK, here's an idea. The resonant cavity's purpose is to produce standing waves, right? So, basically it's a precise arrangement of conducting plates which reflect EM waves back and forth. For some reason, this reminds me of a "macro" Casimir cavity, just on a different scale and with "real" photons. So, what if.. this EM drive acted (by coincidence) as some weird form of "macro" Casimir cavity and its specific shape (accidentally) produced a preferred vector, working with real photons? I seem to remember that specific geometries of Casimir cavities were calculated to be able to produce a preferred vector of motion. I didn't find that piece of info yet again, or perhaps I remember wrongly. Maybe someone else knows better?
I'd say it's doubtful. It's about the lifetime of the  virtual particle before it cease to exist. AFAIK it's short, so they don't go very far before they disappear.

That said there is an interesting analogy. "Temperature" is a measure of a particles velocity, but if the particles are a gas they move in random directions stopped only by their collisions with the container walls or other particles. If you could filter the particles by velocity you would have a way to separate a gas at say room temperature into 2 streams, one quite a bit hotter, one quite a bit colder than room temperature.

Which sounds crazy.

Except the device is called a Ranque-Hilsch or vortex tube and has existed for about 70 years.

http://en.wikipedia.org/wiki/Vortex_tube

[WARNING Rampant speculation ]
If some sort of separation effect is happening with virtual particles (or could be made to) that might explain some thrust measurements.
Title: Re: EM Drive Developments
Post by: CW on 08/03/2014 08:03 am
Considering that both test articles (null and 'real') seemed to produce some measurable thrust (systematic errors excluded), I have the impression that the scientists involved might be victims of the principle of logical implication, which states that from a wrong premise anything can follow, even the correct solution or answer. It would be interesting and very lucky, if they had stumbled upon some new principle by accident, starting from a physically incorrect premise or train of thought. In no case do I think that conservation of momentum can be broken. If real, there must be some form of opposite momentum occurring - in whatever unusual way yet to be observed.
Title: Re: EM Drive Developments
Post by: QuantumG on 08/03/2014 08:29 am
Why are there now two threads for this nonsense?
Title: Re: EM Drive Developments
Post by: francesco nicoli on 08/03/2014 08:38 am
I have no idea whether such a device could work. I see the consensus among physicists is that there should be some unobserved thing which simulates the effect. I believe that is mostly likely.
However, these guys are still nasa scientists, not exactly any Rossi whatsoever. Many of them have doctoral degrees and they are preparing a peer-review publication. So let's wait and see where and whether they made a mistake. As a scientist (albeit in a different discipline) I recognize here the holy fire of curiosity....
Title: Re: EM Drive Developments
Post by: CW on 08/03/2014 09:20 am


I was mainly looking for a short description of a major issue with the experiment that I can feed to people to prompt them to engage their brains for a minute rather than shoveling the bull**** down their throats without thinking. After that some discussion can be sparked to realize the issues at hand.

i think there are two major issues.

1. the signal is very small. this makes it easy for uncontrolled for unanticipated spurious signals to get in there. critic can claim this is what caused it all day long. it's hard to disprove.

2. in this experiment it appears the control test article got the same signal. I do not think this is as damning as it could be because of the signals found by other researchers with (similar devices of differing design details.)  E.G. Dr Woodward's design is a solid state peizoelectric stack. he gets a thrust signal. Dr White has a capacitor and coil ring and gets thrust signals. the Egyptian girl uses a moving casimir mirror and gets a thrust signal. The Chinese use Shayer's design as a starting point and get a much stronger thrust signal than he did or NASA testing got.

I think that what could bring this whole thing forward is to ask, what do all these experimental devices have in common that leads to a measured thrust - as different as they may seem. It could be a systematic error, but it would in turn also be an interesting insight if each and every one group doing these experiments made the same systematic errors. It seems possible, but the less likely, the more groups are independently letting the results get peer-reviewed. I'm looking forward to any kind of result.
Title: Re: EM Drive Developments
Post by: CharlieWildman on 08/03/2014 03:17 pm
Looking at the very small amount of thrust generated I suspect measurement error or a problem with how the testing was set up.

Correct me if I have this wrong but 30 to 50 micro Newtons of thrust (.000030 to .000050 Newton)  equates to about . .003 to .005 grams of thrust.

This tiny amount of force could easily be generated by air currents around what must be a warm to hot test article and could explain why the 'null' test article also produced thrust.

According to the NASA document http://ntrs.nasa.gov/search.jsp?R=20140006052 all testing was done in a vacuum chamber  'at ambient atmospheric pressure'.

I sure hope I'm wrong!!!   


Charlie


Title: Re: EM Drive Developments
Post by: mlindner on 08/03/2014 05:29 pm
They are made by not having any preconceived ideas about applications.

How do you look for a new law in physics?

A friend shared this with me. It makes the point well.
and Visa versa

https://www.youtube.com/watch?v=b240PGCMwV0&feature=player_embedded

It disagrees with experiment. So its wrong.
Title: Re: EM Drive Developments
Post by: hop on 08/03/2014 07:42 pm
The problem is that the article linked is not a scientific paper (http://www.compoundchem.com/2014/04/02/a-rough-guide-to-spotting-bad-science), but a clearly preliminary technical report, the typical "hat on the seat" (copyrighted by me :) ) paper required to ensure to be the first IF a sensational result is confirmed in order to get an high citation index in the future.
A link to the actual paper may be found at
https://plus.google.com/117663015413546257905/posts/C7vx2G85kr4

However this is a conference paper, which in many cases aren't peer reviewed in the same way a journal paper would be. I'm not sure about this particular case.

In any case, if Baez summery is correct, there is really nothing worth talking about here... (which should be no surprise to anyone who read the original abstract)
Title: Re: EM Drive Developments
Post by: Star One on 08/03/2014 07:47 pm
It seems much confusion has arisen here. I have been reading on the Polywell forums that firstly the business with the Null article is not a concern, what you are seeing is an ill chosen abstract by NASA. Please see the quote below for more detail. Secondly, Eagle Works are currently building a suitable test article that will be shipped around to any lab that cares to test it according to further posts on there. They are also building a higher power device again according to posts on there.

Quote
No, the NASA folks shot themselves in the foot with this unclear NTRS abstract, which is very misleading once you have read the complete paper, as birchoff and I did. Birchoff is right, the paper is only $25, and now it's very clear that even ArsTechnica only read the NTRS abstract and didn't download the complete paper before writing and publishing their biased article. Very poor journalism.

The fact is (and the NTRS abstract does not explain this): Eagleworks tested one tapered (frustum) cavity, aka Shawyer's EmDrive; and two Cannae drives which are also asymmetric but different resonant cavities. The Cannae drive is said to work on a purported different principle than the EmDrive, according to its inventor Guido Fetta (a net Lorentz force imbalance of electrons upon top vs bottom wall of the cavity). According to this purported working principle, one Cannae drive had radial slots on its rim as required by Fetta in order to produce net thrust, and the second Cannae drive didn't have those slits and was intended to be a "null test device". But the Cannae null test article… also produced net thrust (20 to 40 µN of net thrust depending of the forward or backward direction).

We're talking of net thrust because of course the setup was also tested with a null 50 ohm load connected, in order to cancel the effect from the drives and detect any detect any spurious force due to EM coupling with the whole apparatus (which exists, at 9.6 µN) and this "null" spurious force was evidently subtracted from any thrust signal due to the drives then tested on the pendulum.

So the fact that the Cannae null test article produced a net thrust doesn't imply the experiment was screwed up. It rather showed that the radial slits required by Guido Fetta for propulsion are not the reason for the thrust, and another theoretical explanation is needed. Absolutely no news on the websites, including wikipedia, actually reports correctly this information.

We can go further by pointing another underestimated yet important fact of those NASA experiments: all tests articles (the EmDrive version, the Cannae drive version, and even the Cannae "null test" version) had a dielectric embedded within. This is a hint for a different theoretical explanation involving EM fields, proper acceleration, mass fluctuation and dielectrics. Maybe Mach effects (due to Mach's principle), as supposed by Woodward and Fearn within the GR theory, or within a scalar-tensor theory of gravity according to Minotti. As for Sonny White, he talks about compressible quantum vacuum fluctuations, but there are flaws about this conjecture regarding the thrust magnitude observed.

http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=2949&start=135#p114590
Title: Re: EM Drive Developments
Post by: Star One on 08/03/2014 08:04 pm


This discovery came about because Shawyer was trying to explain the thrust generated by the microwave transmitters on satellites which exceeded what was expected and required additional fuel to correct.

This would really make an interesting subject to read or a comparison point to read up on.
who you be able to supply a link or a paper?

I second that as I had wondered precisely how anyone even thought to look into this.
Title: Re: EM Drive Developments
Post by: hop on 08/03/2014 08:19 pm
It seems much confusion has arisen here. I have been reading on the Polywell forums that firstly the business with the Null article is not a concern, what you are seeing is an ill chosen abstract. Please see the quote below for more detail.
If the experiments were actually done at atmospheric pressure none of that matters. It's clear from the paper that at least some of the tests were (see fig 22). That fact that it isn't clearly stated for each test is a major flaw in the paper regardless of the results, and strongly suggests the paper wasn't rigerously reviewed.

I don't understand why you think the quoted post would "clear up confusion", it looks like a hand wavy rationalization to me. To most scientists, a "null" that produces the predicted effect would be a strong hint to look for experimental error, not new physics.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/03/2014 08:24 pm
Looking at the very small amount of thrust generated I suspect measurement error or a problem with how the testing was set up.

Correct me if I have this wrong but 30 to 50 micro Newtons of thrust (.000030 to .000050 Newton)  equates to about . .003 to .005 grams of thrust.

This tiny amount of force could easily be generated by air currents around what must be a warm to hot test article and could explain why the 'null' test article also produced thrust.

According to the NASA document http://ntrs.nasa.gov/search.jsp?R=20140006052 all testing was done in a vacuum chamber  'at ambient atmospheric pressure'.

I sure hope I'm wrong!!!   


Charlie

the chinese claim a much bigger thrust signal using a device evolved from Shayer's original design.

http://nextbigfuture.com/2014/07/renewed-hope-for-emdrive-with-nasa.html

Quote
Last year a Chinese team built its own EmDrive and confirmed that it produced 720 mN (about 72 grams) of thrust, enough for a practical satellite thruster. Such a thruster could be powered by solar electricity, eliminating the need for the supply of propellant that occupies up to half the launch mass of many satellites. The Chinese work attracted little attention; it seems that nobody in the West believed in it.
Title: Re: EM Drive Developments
Post by: Star One on 08/03/2014 08:41 pm
It seems much confusion has arisen here. I have been reading on the Polywell forums that firstly the business with the Null article is not a concern, what you are seeing is an ill chosen abstract. Please see the quote below for more detail.
If the experiments were actually done at atmospheric pressure none of that matters. It's clear from the paper that at least some of the tests were (see fig 22). That fact that it isn't clearly stated for each test is a major flaw in the paper regardless of the results, and strongly suggests the paper wasn't rigerously reviewed.

I don't understand why you think the quoted post would "clear up confusion", it looks like a hand wavy rationalization to me. To most scientists, a "null" that produces the predicted effect would be a strong hint to look for experimental error, not new physics.

My overall view is this is going to have wait for the further round of tests in the fall of this year, it looks like at this time there are just too many possible issues with this as it stands. It sounds like what they are planning next is either going to make or break this whole thing, at least that way it will not drag for twenty-five years as cold fusion has done.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/03/2014 08:48 pm
It seems much confusion has arisen here. I have been reading on the Polywell forums that firstly the business with the Null article is not a concern, what you are seeing is an ill chosen abstract. Please see the quote below for more detail.
If the experiments were actually done at atmospheric pressure none of that matters. It's clear from the paper that at least some of the tests were (see fig 22). That fact that it isn't clearly stated for each test is a major flaw in the paper regardless of the results, and strongly suggests the paper wasn't rigerously reviewed.

I don't understand why you think the quoted post would "clear up confusion", it looks like a hand wavy rationalization to me. To most scientists, a "null" that produces the predicted effect would be a strong hint to look for experimental error, not new physics.

My overall view is this is going to have wait for the further round of tests in the fall of this year, it looks like at this time there are just too many possible issues with this as it stands. It sounds like what they are planning next is either going to make or break this whole thing.

Nothing will ever break it.  The tests will fail to show convincing evidence of anomalous thrust, and the proponents of the various reactionless drives will come up with rationalizations for it and explain how they're working on new versions that will fix the problems.  It will continue without end.
Title: Re: EM Drive Developments
Post by: Star One on 08/03/2014 08:55 pm

It seems much confusion has arisen here. I have been reading on the Polywell forums that firstly the business with the Null article is not a concern, what you are seeing is an ill chosen abstract. Please see the quote below for more detail.
If the experiments were actually done at atmospheric pressure none of that matters. It's clear from the paper that at least some of the tests were (see fig 22). That fact that it isn't clearly stated for each test is a major flaw in the paper regardless of the results, and strongly suggests the paper wasn't rigerously reviewed.

I don't understand why you think the quoted post would "clear up confusion", it looks like a hand wavy rationalization to me. To most scientists, a "null" that produces the predicted effect would be a strong hint to look for experimental error, not new physics.

My overall view is this is going to have wait for the further round of tests in the fall of this year, it looks like at this time there are just too many possible issues with this as it stands. It sounds like what they are planning next is either going to make or break this whole thing.

Nothing will ever break it.  The tests will fail to show convincing evidence of anomalous thrust, and the proponents of the various reactionless drives will come up with rationalizations for it and explain how they're working on new versions that will fix the problems.  It will continue without end.

No it won't if it doesn't work EagleWorks will lose interest, the only reason it's getting attention is because of their interest.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/03/2014 09:09 pm
WRT the chinese thrust claim isn't that just 1280 grams away from 1 newton of Thrust?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/03/2014 09:28 pm
Too important to be public. Military knows to release crappy results.
What do you think X34 is for?
Title: Re: EM Drive Developments
Post by: CW on 08/03/2014 09:39 pm
It seems much confusion has arisen here. I have been reading on the Polywell forums that firstly the business with the Null article is not a concern, what you are seeing is an ill chosen abstract. Please see the quote below for more detail.
If the experiments were actually done at atmospheric pressure none of that matters. It's clear from the paper that at least some of the tests were (see fig 22). That fact that it isn't clearly stated for each test is a major flaw in the paper regardless of the results, and strongly suggests the paper wasn't rigerously reviewed.

I don't understand why you think the quoted post would "clear up confusion", it looks like a hand wavy rationalization to me. To most scientists, a "null" that produces the predicted effect would be a strong hint to look for experimental error, not new physics.

My overall view is this is going to have wait for the further round of tests in the fall of this year, it looks like at this time there are just too many possible issues with this as it stands. It sounds like what they are planning next is either going to make or break this whole thing.

Nothing will ever break it.  The tests will fail to show convincing evidence of anomalous thrust, and the proponents of the various reactionless drives will come up with rationalizations for it and explain how they're working on new versions that will fix the problems.  It will continue without end.

In case it were all the same systematic blunder made by all groups involved with similar constructs, as likely or unlikely that may seem, a null-thrust demonstration under vacuum and subsequent working out of the details of such possible blunder, would at least add to the knowledge base as to what kind of measurement setup mistake was made. But in the end, we will see the actual results later this year - they will speak for themselves. Personally, I'd prefer an interesting result showing similar thrust under vacuum of course. But it's also great, if nothing of interest is observed. I'm just a bit worried about NASA's scientific reputation here, considering that a positive result was announced already..
Title: Re: EM Drive Developments
Post by: Raj2014 on 08/03/2014 11:07 pm
Has there been any new news on what NASA will do now?
Title: Re: EM Drive Developments
Post by: Elmar Moelzer on 08/04/2014 02:31 pm
Why are there now two threads for this nonsense?
I reported it to mods earlier, when it was only 5 posts long...
Posted another point over the in the other thread (well one of many on the subject): Where is the electricity coming from? Is it from a battery or capacitor on the thruster or a wall outlet. If it is the latter, then this could be an explanation for the thrust and it would also make the device irrelevant as a thruster.
I think that this mistake was made at least with the Cannae thruster experiment. I am not sure about Shawyers later experiments, though (his setups are pretty big and the power source might be on it).
Another problem is that the Cannae experiments were not done in a vacuum. We might just see ionized air flowing over the device, creating thrust.
Finally, we have the previously mentioned problem that the Null device also created thrust.
All this makes me highly skeptical, though I am more than willing to be positive surprised (would be cool if it worked).
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/04/2014 02:52 pm
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.
Title: Re: EM Drive Developments
Post by: Cinder on 08/04/2014 03:39 pm
It seems much confusion has arisen here. I have been reading on the Polywell forums that firstly the business with the Null article is not a concern, what you are seeing is an ill chosen abstract. Please see the quote below for more detail.
If the experiments were actually done at atmospheric pressure none of that matters. It's clear from the paper that at least some of the tests were (see fig 22). That fact that it isn't clearly stated for each test is a major flaw in the paper regardless of the results, and strongly suggests the paper wasn't rigerously reviewed.

I don't understand why you think the quoted post would "clear up confusion", it looks like a hand wavy rationalization to me. To most scientists, a "null" that produces the predicted effect would be a strong hint to look for experimental error, not new physics.

My overall view is this is going to have wait for the further round of tests in the fall of this year, it looks like at this time there are just too many possible issues with this as it stands. It sounds like what they are planning next is either going to make or break this whole thing.

Nothing will ever break it.  The tests will fail to show convincing evidence of anomalous thrust, and the proponents of the various reactionless drives will come up with rationalizations for it and explain how they're working on new versions that will fix the problems.  It will continue without end.

What is "it"?  Yes it can be broken, with good enough experimental setup.  That is what science is.  If this thing (Cannae or whatever White used and/or renamed) is non-functional, and so simply non-functional, why doesn't someone else demonstrate that?

If that happened, would "they" have any credence (ie employment) at NASA? 
Title: Re: EM Drive Developments
Post by: Elmar Moelzer on 08/04/2014 03:57 pm
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.
The power is provided from a physically connected source, but the source is not accelerated with the device. This means that you are feeding a current from a static system into a moving frame of reference and that could appear as a thrust. And I might be wrong with this, but I am pretty sure that this could be a potential problem, especially when we are dealing with very small amounts of thrust here.
Title: Re: EM Drive Developments
Post by: frobnicat on 08/04/2014 04:15 pm
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.

Don't know the exact setup but it's not trivial to exchange power from laboratory frame to device frame without exchanging momentum down to µN. The thrust of the device is measured as a displacement against a spring. With a torsion pendulum the device should be completely free to rotate about a vertical axis save for a very weak spring restoring force. The torsion wire(s) should be the only mechanical link(s) between lab frame and device frame. If you go current through them they are heating (changing stiffness). If you have other "soft" bent wires they will exert spurious forces. Also 10 cm of straight wire passing only 200mA of current will get about a µN of lateral thrust in the earth magnetic field alone. A curved wire will tend to straighten up a little bit from interaction with its own generated magnetic field. Going wireless would probably be worse as it's basically coupling electromagnets across the two frames. Even optical power transmission has some radiation pressure (not sure how much). All effects that go on when power on and off when power off (like the effect to be measured). I'm sure all that can be mitigated, but it's really far from trivial. Better have the power source on the suspended test bed (though not perfect as it can still electromagnetically interfere with lab/earth frame even in a vacuum)
Edited : 200mA not 20mA
Title: Re: EM Drive Developments
Post by: CW on 08/04/2014 05:14 pm
I don't get it in my head, why each and every one of these experiments seems unable to just put the local power supply on the would-be drive and start the damn thing. It should be an easy task to put the test article in a non-functional mode and record possible forces, while energy is supplied for an exact duration of time. Do this a statistically relevant number of times and e.g. average the recorded data, then make the test article functional (we all wish for that, don't we) and do your real recordings, for the same time duration as for calibrating. Then do a friggin' delta, and you should pretty much know if Scotty farted in the lab or if there is some real stuff going on :) .
Title: Re: EM Drive Developments
Post by: sghill on 08/04/2014 05:41 pm
Hello all,

I think there is one elephant in the room that nobody seems to notice. If the drive is supposed to gain impulse by interaction with virtual particles of the quantum vacuum, then these particles obviously have to be accelerated in the opposed direction in which the drive is accelerated.

Here comes now the elephant: When those accelerated virtual particles (which pop in an out of existence spontaneously) disappear again to who-knows-where, what happens to the impulse that these particles previously gained.. is it gone? I can hardly imagine that this should be the case. So.. where would the imparted impulse on the virtual particles go? Ideas? On the other hand.. please correct me if I'm wrong.. I seem to remember some knowledge that virtual particles were not subject to impulse conservation?

Regards

Welcome to the forum!

[sophomoric speculation] Perhaps the impulse goes to wherever the virtual particles came "from" when they pop out of existence again.  Conservation of momentum only matters in a closed system right? [/sophomoric speculation]
Title: Re: EM Drive Developments
Post by: DanielW on 08/04/2014 05:55 pm
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.

Don't know the exact setup but it's not trivial to exchange power from laboratory frame to device frame without exchanging momentum down to µN. The thrust of the device is measured as a displacement against a spring. With a torsion pendulum the device should be completely free to rotate about a vertical axis save for a very weak spring restoring force. The torsion wire(s) should be the only mechanical link(s) between lab frame and device frame. If you go current through them they are heating (changing stiffness). If you have other "soft" bent wires they will exert spurious forces. Also 10 cm of straight wire passing only 20mA of current will get about a µN of lateral thrust in the earth magnetic field alone. A curved wire will tend to straighten up a little bit from interaction with its own generated magnetic field. Going wireless would probably be worse as it's basically coupling electromagnets across the two frames. Even optical power transmission has some radiation pressure (not sure how much). All effects that go on when power on and off when power off (like the effect to be measured). I'm sure all that can be mitigated, but it's really far from trivial. Better have the power source on the suspended test bed (though not perfect as it can still electromagnetically interfere with lab/earth frame even in a vacuum)

I would like to know more about the experimental set up. But what they have just sounds prone to error. They are not measuring force directly, they are measuring torque. We know that they are passing electrons through wires, but not how those wires are shaped. In a stainless steel container. I can easily think of cases that would create a small torque. induced eddy currents for example. Maybe they just got unlucky that whatever weird EM effects are going on happened to create a net torque in the same direction that they expected a force for the plane of measurement.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/04/2014 07:08 pm
I think they did the test with an RF load also.
They reported no force in this case. That must go someway to eliminating systemic errors in their setup.
Title: Re: EM Drive Developments
Post by: RanulfC on 08/04/2014 07:13 pm
Too important to be public. Military knows to release crappy results.
What do you think X34 is for?

Sure you want to go with that example there? The X-34 never flew and so provided NO data. Just an FYI :)

Randy
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/04/2014 07:14 pm
I think they did the test with an RF load also.
They reported no force in this case. That must go someway to eliminating systemic errors in their setup.

No, they reported there was some thrust detected from the RF load, also, but not as much, and they subtracted that from the measured thrust for the other two devices.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/04/2014 07:15 pm
Too important to be public. Military knows to release crappy results.
What do you think X34 is for?

Sure you want to go with that example there? The X-34 never flew and so provided NO data. Just an FYI :)

Randy
Lol. Fair cop RanulfC!
I 'of course' meant to say the X-37
 :-[
Title: Re: EM Drive Developments
Post by: RanulfC on 08/04/2014 07:20 pm
Too important to be public. Military knows to release crappy results.
What do you think X34 is for?

Sure you want to go with that example there? The X-34 never flew and so provided NO data. Just an FYI :)

Randy
Lol. Fair cop RanulfC!
I 'of course' meant to say the X-37
 :-[

Of course you did, :) Don't forget "we" are watching you... No, really we are, now turn the light back on and open the curtain so we can get a better view...
(Did I ever mention I once had a hobby of "tweeking" the conspiricy theory boards? Loads of fun... The the Illuminatia contacted me... Yes that was a Weird Al reference! :) )

Randy
Title: Re: EM Drive Developments
Post by: CW on 08/04/2014 07:57 pm
Welcome to the forum!

[sophomoric speculation] Perhaps the impulse goes to wherever the virtual particles came "from" when they pop out of existence again.  Conservation of momentum only matters in a closed system right? [/sophomoric speculation]

Thanks for your welcome, sghill.

If you put it like that, it seems to me that 'existence' should comprise some weird form of (in lack of a better word) event horizon that is perhaps comparable to a mirror surface. Maybe physical reality actually takes the form of a mirrored state, while the sum of all vectors over both sides of the mirror half spaces is perfectly zero? If so, then you could even produce BS like 'free energy', because device A then existed on both sides of the mirror with exactly diametral vectors, and everything still nulls out at all times.. NASA, you can do it ::) !
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/04/2014 08:16 pm
I think they did the test with an RF load also.
They reported no force in this case. That must go someway to eliminating systemic errors in their setup.

No, they reported there was some thrust detected from the RF load, also, but not as much, and they subtracted that from the measured thrust for the other two devices.
They did? Going back over the abstract they mention the RF load, but nothing about testing of such.
Did I just overlook it or do you have extra info?
Title: Re: EM Drive Developments
Post by: JasonAW3 on 08/04/2014 08:41 pm
I'm hoping that they find that this gizmo actually works, but if it doesn't, I don't think that they can accuse anyone of fraud this time.  It may be a set of honest mistakes.

I just find it danged interesting that preliminary testing shows a success, even on the rigged device that wasn't supposed to work.

It makes me wonder just what the heck have they found here anyway?
Title: Re: EM Drive Developments
Post by: brokndodge on 08/04/2014 08:50 pm
IANAS - But, I have read the report and it seems to me that they are only reporting on experimental results that they could not explain and honestly didn't expect to see.  The first set of experiments and the "null" (they should have chosen a better word) device indicated results that were unexpected and invalidated 1 theory as to why results were seen.  The so called "null" device was not really such a device. Rather, the engineer that made it had a theory that placing groves in one end of the device would create thrust and that not having the grooves would not create thrust.  He was proven wrong in that the device appeared to create thrust irregardless of the groves. 

The second set of experiments conducted with a different device of a type more closely related to the EMDrive also yielded results.  They were able to take lessons learned about their first experimental setup and apply them to the second set of tests.  As such they were able to test at much higher frequencies. 

Among all of the tests, time available to test has been an issue. They stated in the opening brief about the setup of their vacuum chamber and pendulum that it takes "days" to pull an appropriate vacuum.  Later in the paper they stated that one of the devices used had electrical components that were not vacuum friendly.  I don't recall a specific mention of the second set of tests being performed in a vacuum. 

The paper did not make any conclusions as to what is causing the effect that they are seeing.  It does state that the effect is worth investigating and that they are planning to test a more powerful 1GHz version at other facilities with better equipment.  I believe that at this time such an advanced concept lab as this is doing the right thing in further researching the results that they measured.  I also believe that they are confident to a high enough degree to warrant larger scale testing at facilities that are better equipped for such tests. 

I look forward to the results of such testing whether they be positive or negative.
Title: Re: EM Drive Developments
Post by: Star One on 08/04/2014 08:53 pm
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.
The power is provided from a physically connected source, but the source is not accelerated with the device. This means that you are feeding a current from a static system into a moving frame of reference and that could appear as a thrust. And I might be wrong with this, but I am pretty sure that this could be a potential problem, especially when we are dealing with very small amounts of thrust here.

I assume that's why they are building a more powerful setup to test.

From what I have gathered it mentions somewhere this net setup being sent out to places like the JPL to test, can anyone confirm this?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/04/2014 08:57 pm
IANAS - But, I have read the report and it seems to me that they are only reporting on experimental results that they could not explain and honestly didn't expect to see.  The first set of experiments and the "null" (they should have chosen a better word) device indicated results that were unexpected and invalidated 1 theory as to why results were seen.  The so called "null" device was not really such a device. Rather, the engineer that made it had a theory that placing groves in one end of the device would create thrust and that not having the grooves would not create thrust.  He was proven wrong in that the device appeared to create thrust irregardless of the groves. 

The second set of experiments conducted with a different device of a type more closely related to the EMDrive also yielded results.  They were able to take lessons learned about their first experimental setup and apply them to the second set of tests.  As such they were able to test at much higher frequencies. 

Among all of the tests, time available to test has been an issue. They stated in the opening brief about the setup of their vacuum chamber and pendulum that it takes "days" to pull an appropriate vacuum.  Later in the paper they stated that one of the devices used had electrical components that were not vacuum friendly.  I don't recall a specific mention of the second set of tests being performed in a vacuum. 

The paper did not make any conclusions as to what is causing the effect that they are seeing.  It does state that the effect is worth investigating and that they are planning to test a more powerful 1GHz version at other facilities with better equipment.  I believe that at this time such an advanced concept lab as this is doing the right thing in further researching the results that they measured.  I also believe that they are confident to a high enough degree to warrant larger scale testing at facilities that are better equipped for such tests. 

I look forward to the results of such testing whether they be positive or negative.
Great post.
I may be slow today, but could you supply a link to the paper please?
Cheers mate.
Title: Re: EM Drive Developments
Post by: brokndodge on 08/04/2014 09:10 pm
I think they did the test with an RF load also.
They reported no force in this case. That must go someway to eliminating systemic errors in their setup.

No, they reported there was some thrust detected from the RF load, also, but not as much, and they subtracted that from the measured thrust for the other two devices.
They did? Going back over the abstract they mention the RF load, but nothing about testing of such.
Did I just overlook it or do you have extra info?

There are two sets of tests mentioned in the actual paper (not the NASA abstract).  The first set of tests were limited in power due to RF leakage from the vacuum chamber.  That set of tests was limited to 935 KHz to prevent such leakage.  Three apparatus were tested.  The first 2 were nearly identical pancake shaped devices.  The first of those those had groves cut into the inside rear face of the pancake.  The engineer believed that those grooves would cause or increase the thrust created by it.  The second did not have grooves and is the one refereed to as the null device.  The engineer believed that the absence of grooves in this version would prevent it from creating thrust.  Now, the third apparatus was a simple RF modulator and was the control.  In this first set of tests conducted in August of 13, the first 2 devices created a thrust effect that was nearly identical disproving the engineers theory.  The third (control) apparatus produced 0 thrust at the same power levels used on the first 2.

There was a second set of tests performed on a different device in early 2014.  This test used lessons learned from the first set to eliminate the RF leakage above 1MHz in the vacuum chamber.  During this test there were two apparatus.  The test apparatus and the control which was similar to the control used in the first test.  The control did create about 9.2microN of thrust.  This was determined to be caused by electromagnetic interaction with some magnets inside the vacuum chamber and was compensated for.  I don't know if it was compensated for mathematically or thru physical shielding.  They ran the test apparatus thru a range of frequencies and did achieve varying degrees of thrust that were significant compared to their control.
Title: Re: EM Drive Developments
Post by: brokndodge on 08/04/2014 09:17 pm
IANAS - But, I have read the report and it seems to me that they are only reporting on experimental results that they could not explain and honestly didn't expect to see.  The first set of experiments and the "null" (they should have chosen a better word) device indicated results that were unexpected and invalidated 1 theory as to why results were seen.  The so called "null" device was not really such a device. Rather, the engineer that made it had a theory that placing groves in one end of the device would create thrust and that not having the grooves would not create thrust.  He was proven wrong in that the device appeared to create thrust irregardless of the groves. 

The second set of experiments conducted with a different device of a type more closely related to the EMDrive also yielded results.  They were able to take lessons learned about their first experimental setup and apply them to the second set of tests.  As such they were able to test at much higher frequencies. 

Among all of the tests, time available to test has been an issue. They stated in the opening brief about the setup of their vacuum chamber and pendulum that it takes "days" to pull an appropriate vacuum.  Later in the paper they stated that one of the devices used had electrical components that were not vacuum friendly.  I don't recall a specific mention of the second set of tests being performed in a vacuum. 

The paper did not make any conclusions as to what is causing the effect that they are seeing.  It does state that the effect is worth investigating and that they are planning to test a more powerful 1GHz version at other facilities with better equipment.  I believe that at this time such an advanced concept lab as this is doing the right thing in further researching the results that they measured.  I also believe that they are confident to a high enough degree to warrant larger scale testing at facilities that are better equipped for such tests. 

I look forward to the results of such testing whether they be positive or negative.
Great post.
I may be slow today, but could you supply a link to the paper please?
Cheers mate.

See below from about page 6 of this very thread.  When you follow the link you will have to skip past about 2 or 3 paragraphs of the guy discounting the results to find two links to the actual paper:

The problem is that the article linked is not a scientific paper (http://www.compoundchem.com/2014/04/02/a-rough-guide-to-spotting-bad-science), but a clearly preliminary technical report, the typical "hat on the seat" (copyrighted by me :) ) paper required to ensure to be the first IF a sensational result is confirmed in order to get an high citation index in the future.
A link to the actual paper may be found at
https://plus.google.com/117663015413546257905/posts/C7vx2G85kr4

However this is a conference paper, which in many cases aren't peer reviewed in the same way a journal paper would be. I'm not sure about this particular case.

In any case, if Baez summery is correct, there is really nothing worth talking about here... (which should be no surprise to anyone who read the original abstract)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/04/2014 09:26 pm
Awesome. Some good night-time reading!
Thanks.
Title: Re: EM Drive Developments
Post by: hop on 08/04/2014 09:41 pm
See below from about page 6 of this very thread.  When you follow the link you will have to skip past about 2 or 3 paragraphs of the guy discounting the results to find two links to the actual paper:
On the other hand, anyone interested in the plausibility (or otherwise) of this result may find reading the post and discussion in the comments to be time well spent.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/04/2014 09:47 pm
On the gripping hand we are discussing it here.
Any insights you may have had from reading that post, please repeat here.
I have speed read the paper. Seems very thorough. Of course speed-reading is not good. But at the moment I think they have found something.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/04/2014 10:11 pm
I think they did the test with an RF load also.
They reported no force in this case. That must go someway to eliminating systemic errors in their setup.

No, they reported there was some thrust detected from the RF load, also, but not as much, and they subtracted that from the measured thrust for the other two devices.
They did? Going back over the abstract they mention the RF load, but nothing about testing of such.
Did I just overlook it or do you have extra info?

From reply #88 in this thread:

Quote
We're talking of net thrust because of course the setup was also tested with a null 50 ohm load connected, in order to cancel the effect from the drives and detect any detect any spurious force due to EM coupling with the whole apparatus (which exists, at 9.6 µN) and this "null" spurious force was evidently subtracted from any thrust signal due to the drives then tested on the pendulum.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/04/2014 10:17 pm
Yes. I have the paper now to check for myself.
Thanks anyway
Title: Re: EM Drive Developments
Post by: Star One on 08/04/2014 10:26 pm
To say there is a lot of scepticism on that link is an understatement.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/04/2014 10:43 pm
I think in these things we have to be very careful.
There are two camps:-
1) People who would very much like it to be true.
2) People who say it is (obviously) impossible.

I would put myself in (1) but that doesn't mean I wouldn't except hard results disproving the effect.
Anyway, whichever camp you are in, it pays to be objective and not succumb to confirmation bias.
It can be difficult to do this, but we must try...
Title: Re: EM Drive Developments
Post by: Star One on 08/04/2014 10:48 pm

I think in these things we have to be very careful.
There are two camps:-
1) People who would very much like it to be true.
2) People who say it is (obviously) impossible.

I would put myself in (1) but that doesn't mean I wouldn't except hard results disproving the effect.
Anyway, whichever camp you are in, it pays to be objective and not succumb to confirmation bias.
It can be difficult to do this, but we must try...

Excellent post. I would say I am now of the same view as you on this topic.
Title: Re: EM Drive Developments
Post by: FlyingMoose on 08/05/2014 07:21 pm

This discovery came about because Shawyer was trying to explain the thrust generated by the microwave transmitters on satellites which exceeded what was expected and required additional fuel to correct.

This would really make an interesting subject to read or a comparison point to read up on.
who you be able to supply a link or a paper?

I have spent about 5 hours and have been unable to find it again.  Google is worthless because any keywords I can think of only find hundreds of news articles about the recent NASA experiment.  It was a mention in a forum, it wasn't an official paper.  Perhaps someone with better google-fu can find it.
Title: Re: EM Drive Developments
Post by: sghill on 08/05/2014 07:34 pm
You might want to be rather careful in what you say here otherwise it might look like you're casting aspersions on the NASA scientists and their decision to investigate this.

This is one little corner of NASA.  NASA is a huge organization with lots and lots of people working on lots of things.  Sonny White and friends are not equivalent to NASA as a whole.

And there's nothing wrong with complaining that this one small part of NASA is wasting precious resources that could be better spent, and misleading the public by letting the NASA name get attached to wishful thinking in the guise of science.

Consider this.  Eagleworks is trying to get their inferometer apparatus up and running, and learn how to use it properly for their own proposed warp bubble and Q-thruster experiments.  This experiment- who cares if it's quackery or not- gave them a perfect chance to try out their methods on a completely 3rd party apparatus.  That, in turn, allows them to refine their methods for their own experiments.

If the EMDrive theories are valid, then so much the better.  It still worked to Eagleworks- and NASA's advantage to go through the testing motions without drinking the EMDrive Kool Aid.  The fact that the released paper focused on the testing procedures reinforces this theory IMHO.  Also, I think the soundness of Eagleworks performing this testing is further reinforced by the fact that the test article also generated thrust, so there were possibly problems (again IMHO) in their procedures that this testing exposed.

In other words, it's better for them to report false positives with the EMDrive thruster than their own Q-thruster right?!? :)
Title: Re: EM Drive Developments
Post by: Star One on 08/05/2014 08:48 pm
A rather bizarre argument has blown up on this over at the Polywell forums on the main thread, I am not going to clog this forum with it but it did leave me rather scratching my head. I don't think I've known any other recent scientific story that's attracted such odd commentary, it's made me despair of whole chunks of the internet.:) This forum is a positive oasis of sanity.
Title: Re: EM Drive Developments
Post by: aero on 08/05/2014 08:51 pm
In case it hasn't been posted, the full AIAA paper is available here:

http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum (http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum)

A quick scan discovered the interesting item, that not two, but four devices were tested and reported. Three resulted in force being measured repeatably. Two devices were the disk shaped Cannae device, one of which was designed for null results but produced force anyway, one device was the Eagelworks in-house design, a conical shaped device similar the original Roger Shawyer and the chinese devices and the fourth device was a brick shaped RF load. It did not produce thrust.

So what we have is at least 5 devices which have been reported as producing thrust, and at least 3 different test set-ups that have been blamed as being faulty by the blogger community, each with a different fault. To me, it seems time to apply Occam's razor.

It is easy to show that the undetected flaw which the EagleWorks Lab is accused of, would not have gone undetected at the Chinese high power test. The suspected flaw is force resulting from heating and convective air flow. But in the Chinese high power test in order for this mechanism to give the measured force, the mass of air flow (mdot)  times the change in air velocity (Ve) must equal the measured force. But that air flow would be easily detected by anyone who casually glanced at the operating device. So the flaw is different for different test set-ups.

So in the end, there can be either a different flaw for each test set-up, or there can be one unknown but reproducible force generating mechanism. What does Occam's razor say?
Title: Re: EM Drive Developments
Post by: aero on 08/05/2014 08:57 pm
If you want to see bizarre, go here:

http://www.physforum.com/index.php (http://www.physforum.com/index.php)

But this is a hot blogger topic world wide, I checked a French and Czech blog site (Google Translate) and they seem to be very hard over on this subject, too. Most bloggers seem to behave as though they fear that the EM drive will steal their women and destroy their sex life.
Title: Re: EM Drive Developments
Post by: Star One on 08/05/2014 09:12 pm

If you want to see bizarre, go here:

http://www.physforum.com/index.php (http://www.physforum.com/index.php)

But this is a hot blogger topic world wide, I checked a French and Czech blog site (Google Translate) and they seem to be very hard over on this subject, too. Most bloggers seem to behave as though they fear that the EM drive will steal their women and destroy their sex life.

See my post above I have genuinely been concerned by some of the commentary related to this I've read.
Title: Re: EM Drive Developments
Post by: GregA on 08/05/2014 10:33 pm
Guys I applaud trying to stay on topic, but you're giving so little detail I have no idea what you're talking about. Going to that site shows some terrible "scientific" thoughts, is that what you mean.

Perhaps it needs a separate thread on "misunderstanding science" or whatever the concern is - otherwise an illustration of your concern would be great :)
Title: Re: EM Drive Developments
Post by: aero on 08/05/2014 11:29 pm
Guys I applaud trying to stay on topic, but you're giving so little detail I have no idea what you're talking about. Going to that site shows some terrible "scientific" thoughts, is that what you mean.

Perhaps it needs a separate thread on "misunderstanding science" or whatever the concern is - otherwise an illustration of your concern would be great :)

A problem with blogging about EM Drive is this: There are no theoretical underpinnings to the experimental devices. That means that there is no means to evaluate the experiment performed relative to the underlying theory since there isn't any. Well, that's not quite true, there are home grown ideas of a theory for each experimenter, but no theory that is accepted outside its own laboratory. Some of the theories seem laughable and some of them have been proven to be wrong.

The situation as it stands currently is that the general blogger community spends their creative energy trying to imagine a flaw in the experiments which would give the measured results. Of course flaws can be imagined and theories can be laughed at, but doing so does not advance scientific knowledge, and worse, such possible flaws are advanced very loudly without benefit of understanding the published papers which in some cases clearly describe actions taken by the experimenter to avoid such flaws.

It seems that the widely held belief is "If it is not explained by the Standard Model, then it is not physics."

What I had hoped is that some knowledgeable people would propose an idea for a theory that could then be massaged by the community into something worthy of consideration. Instead what I have found is that when a germ of an idea is presented the response is, along the lines of, "There was no force, it was a deflection of a spring which could have been caused by ...(this or that reason). Engineers can't do science, only scientists can do science." In the end, the experimenters are commonly accused of holding their thumbs on the scales.

But that is just my observation. There are several papers about EM Drive available on the internet, including the NASA paper I linked above. Read the full paper, not just the abstract, then check some of the blog sites around the net. I think you will see the lack of rational thought for yourself.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/06/2014 02:58 am
In case it hasn't been posted, the full AIAA paper is available here:

http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum (http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum)

A quick scan discovered the interesting item, that not two, but four devices were tested and reported. Three resulted in force being measured repeatably. Two devices were the disk shaped Cannae device, one of which was designed for null results but produced force anyway, one device was the Eagelworks in-house design, a conical shaped device similar the original Roger Shawyer and the chinese devices and the fourth device was a brick shaped RF load. It did not produce thrust.

So what we have is at least 5 devices which have been reported as producing thrust, and at least 3 different test set-ups that have been blamed as being faulty by the blogger community, each with a different fault. To me, it seems time to apply Occam's razor.

It is easy to show that the undetected flaw which the EagleWorks Lab is accused of, would not have gone undetected at the Chinese high power test. The suspected flaw is force resulting from heating and convective air flow. But in the Chinese high power test in order for this mechanism to give the measured force, the mass of air flow (mdot)  times the change in air velocity (Ve) must equal the measured force. But that air flow would be easily detected by anyone who casually glanced at the operating device. So the flaw is different for different test set-ups.

So in the end, there can be either a different flaw for each test set-up, or there can be one unknown but reproducible force generating mechanism. What does Occam's razor say?

The proper question to ask of Occam's razor whether it's more likely that three small groups made mistakes in their test setups that gave them the results they desperately wished to see, or that tens of thousands of physicists working over decades completely failed to find an effect that is easy to produce on a variety of different devices that are simple to make.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/06/2014 03:02 am
Of course flaws can be imagined and theories can be laughed at, but doing so does not advance scientific knowledge

If there is a good reason to suspect an experimental flaw, pointing out that reason and spreading the idea about that flaw does absolutely advance scientific knowledge.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/06/2014 04:20 am
without knowledge; such a thing may be equivalent to shouting "Swamp Gas!" at every unknown areal phenomenon though. it may be that it's not Swamp Gas; It Could be Venus! or a illumination flare. a person that reflexively hollers swamp gas isn't advancing science. whether it really is a LGM or if it turns out to be any explanation other than swamp gas. the swamp gas camp does a diservice if it is really Venus and they didn't bother to check things out. the real thing remains unknown if the debunking is via the critic's own bunkum.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/06/2014 04:28 am
I was replying to an unqualified statement with a qualified statement.  The unqualified statement I was replying to said that claiming flaws does not advance science.  My reply was qualified, to point out that in some cases it does.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/06/2014 04:33 am
I see. I missed that. My mistake.
Title: Re: EM Drive Developments
Post by: aero on 08/06/2014 04:37 am
Quote
The proper question to ask of Occam's razor whether it's more likely that three small groups made mistakes in their test setups that gave them the results they desperately wished to see, or that tens of thousands of physicists working over decades completely failed to find an effect that is easy to produce on a variety of different devices that are simple to make.

No. The proper question to ask of Occam's razor whether it's more likely some large number of the tens of thousands of physicists working over decades are righteously offended after completely failing to investigate an unknown effect that is easy to produce on a variety of different devices that are simple to make after one man stumbled across that effect and three small groups reproduced it, or if the effect could in fact be real.

Title: Re: EM Drive Developments
Post by: aero on 08/06/2014 04:54 am
Quote
If there is a good reason to suspect an experimental flaw, pointing out that reason and spreading the idea about that flaw does absolutely advance scientific knowledge.

While that is true, it is also true that the main reason to suspect an experimental flaw is that posters don't understand how the device could work as claimed. Now this may be a good reason, but I don't think so. No one knows everything. I have suggested that a better way to advance science would be to propose a germ of an idea that could maybe explain the phenomena for further development by the crowd. Crowd sourced science.

Of course it is hard to propose an idea because doing so sets the proposer up as the butt of the criticism that is currently aimed at the experimenters. What sane person would eagerly step into that line of fire? In order for crowd sourced science to work, the thread would need a strong and heavy handed moderator, with name calling an absolute "no-no."
Title: Re: EM Drive Developments
Post by: aero on 08/06/2014 07:54 am
I just finished reviewing the full AIAA paper that NASA submitted. There are several very interesting details once you get into the meat of it. One thing in particular was this:

Quote
There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber. The geometry, location, and material properties of this resonator must be evaluated using numerous COMSOL® iterations to arrive at a viable thruster solution. We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust.

I don't know what it means, but it says that they took out one little piece and that little piece proved to be critical to producing thrust.

Of course I guess that little piece could have been central to the "experimental error."

What is a dielectric RF resonator and what is it used for?

Another point of interest is that that COMSOL® computer program they have seems to predict the thrust produced to quite high fidelity. I guess the computer program must have a built in "experimental error" bias.

Read the paper people, quit fooling yourselves with second hand information.
Title: Re: EM Drive Developments
Post by: MP99 on 08/06/2014 09:17 am



This discovery came about because Shawyer was trying to explain the thrust generated by the microwave transmitters on satellites which exceeded what was expected and required additional fuel to correct.

This would really make an interesting subject to read or a comparison point to read up on.
who you be able to supply a link or a paper?

I have spent about 5 hours and have been unable to find it again.  Google is worthless because any keywords I can think of only find hundreds of news articles about the recent NASA experiment.  It was a mention in a forum, it wasn't an official paper.  Perhaps someone with better google-fu can find it.

Sounds like this may be of some use, then, to weed out the new news:-

http://www.quora.com/Can-I-restrict-Google-searches-by-a-date-range

Cheers, Martin
Title: Re: EM Drive Developments
Post by: Darkseraph on 08/06/2014 09:33 am
I suppose the question to ask next is, Has NASA finally invented a thruster that finally defies Betterridge's Law of Headlines?


Color me skeptical after Flesichmann-Ponns, OPERA...

Great if it was true (or terrifying considering the inevitable military applications) but I will wait a while this blows over and see if it sticks.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/06/2014 01:55 pm
I step into this debate with trepidation. My perspective is that neither proponent has developed a successful characterisation of any effect...

Pretty much Bingo, I'd say.  Still, I think that NASA is correct to offer them the opportunity to test.  From:

http://ntrs.nasa.gov/search.jsp?R=20140006052

Quote
Financial Sponsor: NASA Johnson Space Center; Houston, TX, United States

I imagine that NASA spent an appropriate sum on this testing.  There has to be some official acknowledgement that these people are attempting to validate a theory, and they do need a place to set up the experiment.  I also noted the results for the null article.

The commentary on the intertubes site that I read is, well, inspiring and informative:

This is strangely arousing. (http://sploid.gizmodo.com/nasa-reveals-new-impossible-engine-can-change-space-t-1614549987)

Sabina's yoga class is at 5:30 this afternoon.  Sadly, I guess, neither strange nor arousing, nor dismissive of the laws of physics.  You can't get into a pose that you can't get into.

Quote from: Steve Kelsey
A rocket motor utilises the shape of the nozzle to convert chemical energy to a directed force, which we call thrust. Is it possible that all that happening here is microwave energy is converted to thrust by the shape of the chamber?

They never photograph the "other end" of the "nozzle".  I do not believe that it is open.  No matter is expected to be expelled from the thought to be open end of the nozzle.  The device is expected to move without expelling matter.

In essence, they claim to be able to convert electricity to microwaves to forward momentum.

Image found at:

http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum
Title: Re: EM Drive Developments
Post by: Star One on 08/06/2014 02:17 pm
I suppose the question to ask next is, Has NASA finally invented a thruster that finally defies Betterridge's Law of Headlines?


Color me skeptical after Flesichmann-Ponns, OPERA...

Great if it was true (or terrifying considering the inevitable military applications) but I will wait a while this blows over and see if it sticks.

What military applications, I could see you could produce a very stealthy air vehicle through it but what else?

Updated article based on the full paper.

http://nextbigfuture.com/2014/08/full-nasa-cannae-drive-and-emdrive-test.html

@JohnFornaro

What is they say extraordinary claims need extraordinary evidence to back them up.
Title: Re: EM Drive Developments
Post by: Elmar Moelzer on 08/06/2014 03:02 pm
What military applications, I could see you could produce a very stealthy air vehicle through it but what else?
As you say, stealth is one thing, the other is endurance. With solar cells, this thing could stay aloft for a long time, provided it really works as advertised...
Title: Re: EM Drive Developments
Post by: DMeader on 08/06/2014 04:36 pm
From xkcd:
(http://imgs.xkcd.com/comics/quantum_vacuum_virtual_plasma.png)
Title: Re: EM Drive Developments
Post by: frobnicat on 08/06/2014 06:16 pm
Back of the envelope rough order of magnitude basic physics principles sanity check :

Let's call L the thrust to power ratio (all SI)
For recall L for physically accepted photon rocket is 1/c = 3e-9 N/W
Cannae cavities tests claim about (order of magnitude) 1µN/W = 1e-6 N/W
Based on the Chinese experiments and their (empiric ?) formulas they expect possibility about 1N/kW = 1e-3 N/W

( I wonder on the nearly 3 orders of magnitude better results of Chinese ... why couldn't they try to replicate the exact same setup, even lower power as thrust would scale linearly or are there expected non linearities with power density ? )

On a given inertial frame a ship of mass M that goes from speed V to speed V+dV in a small time step dt will gain a kinetic energy dE=1/2 M (V²+2VdV+dV² - V²)=MVdV (discarding second order). That's a received power (in kinetic energy form in the given inertial frame) Pr = dE/dt = MVdV/dt = MVa = MVF/M = VF  ( where F is the thrust and a=F/M is the acceleration of the ship)
Pu is power used by the EM drive : L=F/Pu  or F=LPu, replacing F in above result : Pr=VLPu and finally Pr/Pu=VL

If the ship speed V is faster than Vf=1/L on any given inertial frame then it is now gaining more kinetic energy (relative to this arbitrary frame) than it is spending from its onboard generator. For a photon rocket Vf = c, nice because any arbitrary frame wont get you there.
For the tested and expected devices Vf goes from (again very roughly) 1000 km/s (Cannae) to 1km/s (about Chinese claims and what get them to Saturn in 9 Months straight, or rather  2.5km/s given 0.4 N/kW)

That is IF this L ratio wont depend on some absolute reference frame... So you are not only pushing on a medium that conveniently is always harvested at 0 speed relative to your ship, by doing so you are gaining more energy than spending as soon as above a very modest speed (relative to whatever ground), effectively pumping into the zero point vacuum. They even seem to hope for L=4N/kW, that's a Vf of 250m/s, that's slow enough to be mounted around a rotor : compact free energy generator ! Is this consequence seriously addressed by the Q-thruster theorists ?

If the L ratio depend on some absolute reference frame then the effect would be of lower magnitude when approaching those speeds relative to this frame. Back to aether problems : locally anchored to nearest massive body ? Else the effect would depend on orientation (Michelson-Morley...)

Vf stands for "Velocity of free energy", or "Velocity fishy"

Title: Re: EM Drive Developments
Post by: SteveKelsey on 08/06/2014 07:32 pm
I agree with aero the report is worth a careful read. Much of the critique on this thread is answered.
The parts of the report that struck me as being  interesting are:-

There were four test elements

1)   A Shawyer based truncated cone design ( There are images of the closed end in the report John F : ) )
2)   A Cannae Test component with slots
3)   A Cannae test component without slots
4)   A Null test component consisting of a 50 ohm resistive load

The Null test article was useful in identifying a 9.6  micronewton force due to a 5.6 amp current running in the DC supply cable. This Null Force’ was subtracted from the results.

It is reported that the torsion balance can measure down to 1 micronewton

The test protocol included pre and post test calibrations of the balance for each run

Of the four items tested  the 50 ohm load did not produce a force

All of the three test articles, including the Cannae test article without slots  which was anticipated would NOT produce a thrust , produced thrusts well above the sensitivity limit of the balance.

The dielectric does seem to be significant.

It is also clear that this report is part of an ongoing program and the next step is to test at higher power and in a hard vacuum.

Not what I expected, and interesting.

It may still be the result of a test protocol anomaly but there is reason to continue.
Title: Re: EM Drive Developments
Post by: Star One on 08/06/2014 08:14 pm
Guys I applaud trying to stay on topic, but you're giving so little detail I have no idea what you're talking about. Going to that site shows some terrible "scientific" thoughts, is that what you mean.

Perhaps it needs a separate thread on "misunderstanding science" or whatever the concern is - otherwise an illustration of your concern would be great :)

See link below.

http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=5469

Make of what is posted in there what you will.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/06/2014 08:29 pm
Am proud to be part of the Interesting Times Gang (Thanks Mr Banks.)
I really am intrigued to see the scientific method working properly here (not the blogosphere.) We will see hopefully sooner rather than later what is going on.
 ;D
Title: Re: EM Drive Developments
Post by: Space OurSoul on 08/06/2014 08:37 pm
XKCD weighs in:

http://xkcd.com/1404/ (http://xkcd.com/1404/)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/06/2014 08:40 pm
Guys I applaud trying to stay on topic, but you're giving so little detail I have no idea what you're talking about. Going to that site shows some terrible "scientific" thoughts, is that what you mean.

Perhaps it needs a separate thread on "misunderstanding science" or whatever the concern is - otherwise an illustration of your concern would be great :)

See link below.

http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=5469

Make of what is posted in there what you will.
Just speed-read that thread. Isn't GIThruster someone who was banned from NSF back-in-the-day before my time here? What was the score with him? (I can probably guess..)
I'm glad to be with sensible people who can discuss this properly here at NSF.
Title: Re: EM Drive Developments
Post by: Star One on 08/06/2014 09:04 pm
Guys I applaud trying to stay on topic, but you're giving so little detail I have no idea what you're talking about. Going to that site shows some terrible "scientific" thoughts, is that what you mean.

Perhaps it needs a separate thread on "misunderstanding science" or whatever the concern is - otherwise an illustration of your concern would be great :)

See link below.

http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=5469

Make of what is posted in there what you will.
Just speed-read that thread. Isn't GIThruster someone who was banned from NSF back-in-the-day before my time here? What was the score with him? (I can probably guess..)
I'm glad to be with sensible people who can discuss this properly here at NSF.

Much appreciate the background info and I apologise if people think the thread was inappropriate as a result, I would say in my defence I didn't know he had a known NSF history.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/06/2014 09:11 pm
I really don't know about him/her. Maybe someone who has been here longer can elucidate?
I seem to remember a thread title being "....... (GIThruster, now banned.)....."
Anyway, it doesn't really matter. The thread you linked was interesting but was more full of vitriol than science and reason. IMHO
Title: Re: EM Drive Developments
Post by: Star One on 08/06/2014 09:20 pm

I really don't know about him/her. Maybe someone who has been here longer can elucidate?
I seem to remember a thread title being "....... (GIThruster, now banned.)....."
Anyway, it doesn't really matter. The thread you linked was interesting but was more full of vitriol than science and reason. IMHO

I didn't like the personal vitriol posted in it but felt the thread illustrated what I was talking about last night as regards some of the extreme responses to this particular topic.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/06/2014 09:24 pm

I really don't know about him/her. Maybe someone who has been here longer can elucidate?
I seem to remember a thread title being "....... (GIThruster, now banned.)....."
Anyway, it doesn't really matter. The thread you linked was interesting but was more full of vitriol than science and reason. IMHO

I didn't like the personal vitriol posted in it but felt the thread illustrated what I was talking about last night as regards some of the extreme responses to this particular topic.
Apologies to all if I missed stuff. I tend to speed-read things.
Bad habit I know.
Title: Re: EM Drive Developments
Post by: Raj2014 on 08/06/2014 09:26 pm
What is the latest news on the EM drive/Cannae drive? I have found a website saying that NASA did not validate the test, http://blogs.discovermagazine.com/outthere/2014/08/06/nasa-validate-imposible-space-drive-word/#.U-KZq4BdUdg. I hope this is not true and that there will be more tests done proving this method of propulsion does work.
Title: Re: EM Drive Developments
Post by: Star One on 08/06/2014 09:31 pm

What is the latest news on the EM drive/Cannae drive? I have found a website saying that NASA did not validate the test, http://blogs.discovermagazine.com/outthere/2014/08/06/nasa-validate-imposible-space-drive-word/#.U-KZq4BdUdg. I hope this is not true and that there will be more tests done proving this method of propulsion does work.

Maybe I misread but that appears to be yet another article based on the abstract and not the full paper. If it is the writer has erred.
Title: Re: EM Drive Developments
Post by: aero on 08/06/2014 09:50 pm
Yea. The latest news is that bloggers are still writing without reading. There is one blogger who has evidently read the full paper but I'll need to find the link again. Let me refer you to the full paper in the mean time.

http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum (http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum)

Looking at the paper it is easy to see why people might skim through it. It is 20 pages and dry reading, but it has several nuggets in it. The full paper explains many of the misunderstandings that come from reading the widely available abstract and leaves a much more positive impression. IMO

Here is the link to the article in Next Big Future that I alluded to.

http://nextbigfuture.com/2014/08/full-nasa-cannae-drive-and-emdrive-test.html (http://nextbigfuture.com/2014/08/full-nasa-cannae-drive-and-emdrive-test.html)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/06/2014 10:39 pm
Yea. The latest news is that bloggers are still writing without reading. There is one blogger who has evidently read the full paper but I'll need to find the link again. Let me refer you to the full paper in the mean time.

http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum (http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum)

Looking at the paper it is easy to see why people might skim through it. It is 20 pages and dry reading, but it has several nuggets in it. The full paper explains many of the misunderstandings that come from reading the widely available abstract and leaves a much more positive impression. IMO

Here is the link to the article in Next Big Future that I alluded to.

http://nextbigfuture.com/2014/08/full-nasa-cannae-drive-and-emdrive-test.html (http://nextbigfuture.com/2014/08/full-nasa-cannae-drive-and-emdrive-test.html)
I read that. A good summary but not much else. (Unless I am missing something, entirely possible.)
Comments are par for the course.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/06/2014 10:46 pm
For what it's worth I speed-read a lot of things and I'm good at it.
I am still going over the NASA paper properly.
So far I think that they have been very careful about outside influences.
Ion wind, heat based stuff not so much... I will continue pouring over it.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/06/2014 10:49 pm
Think they need a mu-metal shield already.  :(
Title: Re: EM Drive Developments
Post by: Star One on 08/06/2014 10:51 pm

For what it's worth I speed-read a lot of things and I'm good at it.
I am still going over the NASA paper properly.
So far I think that they have been very careful about outside influences.
Ion wind, heat based stuff not so much... I will continue pouring over it.

How about testing in hard vacuum with a Tesla cage around it?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/06/2014 10:55 pm

For what it's worth I speed-read a lot of things and I'm good at it.
I am still going over the NASA paper properly.
So far I think that they have been very careful about outside influences.
Ion wind, heat based stuff not so much... I will continue pouring over it.

How about testing in hard vacuum with a Tesla cage around it?
Yes, but that would be difficult and expensive! How about testing on the ISS with a Faraday cage (I'm sure you meant this!) and mu-metal components?
I agree
Title: Re: EM Drive Developments
Post by: bubbagret on 08/06/2014 10:55 pm

For what it's worth I speed-read a lot of things and I'm good at it.
I am still going over the NASA paper properly.
So far I think that they have been very careful about outside influences.
Ion wind, heat based stuff not so much... I will continue pouring over it.

How about testing in hard vacuum with a Tesla cage around it?

You mean Faraday cage supposedly...
Title: Re: EM Drive Developments
Post by: GregA on 08/06/2014 10:57 pm

Here is the link to the article in Next Big Future that I alluded to.

http://nextbigfuture.com/2014/08/full-nasa-cannae-drive-and-emdrive-test.html (http://nextbigfuture.com/2014/08/full-nasa-cannae-drive-and-emdrive-test.html)
Thanks for showing what you didn't like about the commentary. And this link!
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/06/2014 11:00 pm
doesn't Woodward do that with his version of this thing?  i seem to remember that in one of the many Woodward videos i have seen. if i remember correctly his unit has an integral Faraday cage and then that plexigrass cylinder is a vacuum chamber. the device is put on a torsion balance inside the vacuum chamber thing.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/06/2014 11:23 pm
interview for woowoo type science fringey newszine. but has picture of his test chamber and his thrust traces, thermal traces and so forth. his claim is for 40 mg and 50mgs of thrust signal:

http://www.frequency.com/video/mach-effect-warp-drives-stargates-by-jim/166119888/-/5-905277

Dr Woodward chokes trying to stifle a laugh at a question the interviewer asks:

https://www.youtube.com/watch?v=tIvtnh1awFQ

Woodward giving a talk at a non woowoo space conference:

https://www.youtube.com/watch?v=hn8hqX9JBOE
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/06/2014 11:53 pm
We need more than this Stormbringer.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/06/2014 11:57 pm
i know. i am missing a video somewhere and iam looking for the one where Woodward himself give the explanation of his set up including the contacts on his torsion balance and stuff. i am trying to find it. but meanwhile Dr Woodward's web page has links to his papers and stuff:

http://physics.fullerton.edu/~jimw/

I'm still looking for that video. i know i watched just a couple of weeks ago. :(

still can't find the video. still looking however here is Dr Paul March's PPT presentation slides. there are several good pictures of his device and charts and test rigs from 2003.

http://www.powershow.com/view1/f70a5-ZDc1Z/Paul_March_powerpoint_ppt_presentation
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/07/2014 12:00 am
You could have Ernst Mach himself argue the current state-of-the-art.
It wouldn't make any difference.
We just don't know.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/07/2014 12:10 am
You could have Ernst Mach himself argue the current state-of-the-art.
It wouldn't make any difference.
We just don't know.

that's not important. what is important is his set up details and his results. both of which i can show with what i am putting up and with that video if i can find it.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/07/2014 02:02 am
i still have not found it if someone could help me out in finding it I'd appreciate it. 'Cos i now want to download it to my hard drive so i don't lose it again as well as to link or embed it here.

In the video i have in mind he pointed to and covered all the components going into detail on the Faraday cage the ceramic stack, the mounting block for the stack, the balance pivot there were two rather big wire ribbon wrapped cables mounted to the pivot and leading off towards the stack itself. He explained how the type of contact s were important because they had to be forceless. he then spoke about how the stack produced a thrust signal but wore out and "died" he then showed the traces for thermal and thrust and i think two other traces (maybe power and something else) and showed where in the data traces the device died.
Title: Re: EM Drive Developments
Post by: aero on 08/07/2014 04:20 am
Getting back to EM Drive, am I correct in thinking that the higher the frequency the more power consumed and the smaller the RF resonator?

I'm trying to guess how large a mature EM Drive might be physically? (Assuming that it does mature.) I'm pretty sure that the power sources would be a lot bigger than the EM Drive itself.

From what I've read it doesn't look like there is any reason to hang the drives off the tail end of the spaceship, rather just set them in the electronics bay, or maybe in the Captain's cabin. Of course they would need to be attached to a thrust structure. If you wanted redundancy you could just weld 20 or so of the 5% sized EM Drives on the stern of your spaceship.

I'm hoping that by the end of the year we can start speculating configurations in earnest.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/07/2014 04:34 am
well don't overlook another possibility. if these things work the final form might not be a single big device or set of big devices. the final form might be thousands (or millions) of tiny ones in some sort of array :) a drive on a chip.
Title: Re: EM Drive Developments
Post by: aero on 08/07/2014 05:13 am
well don't overlook another possibility. if these things work the final form might not be a single big device or set of big devices. the final form might be thousands (or millions) of tiny ones in some sort of array :) a drive on a chip.

Yes, they could be pretty small but the size of the resonance cavity is driven by the frequency of the RF power. At 2 GHz the cavity is about 7 cm x 3.5 cm (length doesn't matter) and working with higher frequencies gets more challenging. But that's all I know about that.
Title: Re: EM Drive Developments
Post by: GregA on 08/07/2014 05:25 am
Yes, every floor could have them, which alters the structural strengthening needed.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/07/2014 05:48 am
But if the driver freq was in terahertz or...? or the form of the device was the solid state version Woodward favors?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/07/2014 05:52 am
Getting back to EM Drive, am I correct in thinking that the higher the frequency the more power consumed and the smaller the RF resonator?

I'm trying to guess how large a mature EM Drive might be physically? (Assuming that it does mature.) I'm pretty sure that the power sources would be a lot bigger than the EM Drive itself.

From what I've read it doesn't look like there is any reason to hang the drives off the tail end of the spaceship, rather just set them in the electronics bay, or maybe in the Captain's cabin. Of course they would need to be attached to a thrust structure. If you wanted redundancy you could just weld 20 or so of the 5% sized EM Drives on the stern of your spaceship.

I'm hoping that by the end of the year we can start speculating configurations in earnest.
I like this. Do we need to wait until further confirmation to speculate on spacecraft configs?
We all know that the propellant-less thrust effect may be false, but shirley it is worth exploring.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/07/2014 05:55 am
I favor in between the outer hull and the pressure vessel wall with various orientations to provide agility.

EDIT:  maybe a couple of panels of them or maybe 4 panels mounted on gimbals to change the orientation through a spherical 360 degrees.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/07/2014 06:00 am
I think a puller config would be best. So mount these things at the prow. Yes?
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/07/2014 06:04 am
they really could go anywhere if they were attached to some significant structure of the ship like a keel or the 'tween hulls. so up front should work. but why not go for a configuration that negates the need for a separate set of maneuver engines thrusters? make them mobile or have some for each axis.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/07/2014 06:10 am
i guess if you had them inside the pressure hull you could maintain or replace modules while in a shirt sleeve environment.  your engineers would thank you.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/07/2014 06:33 am
I guess you would have separate cavities for each axis. You would need them fore and aft for rotation.
They all would have to be superconducting. I think that would be best done outside the pressure hull. Not sure.
Title: Re: EM Drive Developments
Post by: aero on 08/07/2014 07:25 am
Why would they need to be superconducting, the test articles weren't?

And I wonder if somehow some RF electronics wizard could manage to change thrust direction electronically. Doesn't matter to much, these things are small and low mass. But before I can decide whether to mount them inside or outside the pressure hull, I'd like to know for sure that the hull doesn't interfere with the drive and that the drive isn't a safety hazard for the crew. If that's all OK I might mount the control thrusters inside the pressure hull in cabinets near the same relative locations where we currently mount them.

As for the main drives, I think I would distribute them throughout the ship to reduce the need for massive force transfer structures from the engines to the rest of the ship structure. I might even double them up with each pair having a forward and a reverse thruster. Heck, I might even do away with the bow and stern idea, and build a double ender, with a bow on both ends. That way there would be no need for a turn over maneuver, just put it in reverse. Of course the thrusters could be swiveled, instead. There are no rigid fuel lines, just a flexible microwave cable. Need to look at reliability to decide.
Title: Re: EM Drive Developments
Post by: aero on 08/07/2014 07:35 am
I did some thrust calculations for the truncated cone EM Drive using F = .0912 mN at 17 W input power. I then ranged jet energy from 10 to 17 watts.

Calculated Isp ranges from 22,400 s (10 W) to 38,000 s (17 W)
Calculated mdot, ranges from 4.16E-10 kg/s (10 W) to 2.45E-10 kg/s (17 W).
That is a nice range to be in.

If I assume the power electronics are 60% efficient, jet energy is 10.2 W, so Isp = 22,800 seconds and mdot = 4.08E-10 kg/s.

Now all that is needed is a theroy of where that mdot comes from and where it goes to! It does occur to me that if we knew the amount of waste heat coming off the EM Drive we could estimate the jet energy from the experiment using total energy = jet energy + waste energy.
------------------
1) Thrust, F = mdot * Ve, and
2) jet energy, E = 0.5 mdot * Ve^2
 substituting 1) into 2) clears mdot and gives
E = 0.5 F * Ve so Ve = 2* E /F . Now calculate mdot from 1).
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/07/2014 08:26 am
well i don't know about shayer's...but is the thermal trace that woodward graphs the waste heat?
Title: Re: EM Drive Developments
Post by: Star One on 08/07/2014 03:58 pm

For what it's worth I speed-read a lot of things and I'm good at it.
I am still going over the NASA paper properly.
So far I think that they have been very careful about outside influences.
Ion wind, heat based stuff not so much... I will continue pouring over it.

How about testing in hard vacuum with a Tesla cage around it?

You mean Faraday cage supposedly...

Yes I don't know why I said Tesla.

The reason I mentioned those two is I saw a number of online commentators claiming these are the sort of tests it needed to be subjected too.

Far be it for me too suggest they were setting deliberately high hurdles.
Title: Re: EM Drive Developments
Post by: aero on 08/07/2014 06:33 pm
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive (http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive)

Title: Re: EM Drive Developments
Post by: Star One on 08/07/2014 07:01 pm
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive (http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive)

It does make one very important point that is there is no agreed theory on how high temperature superconductors work but because they have been replicated so many times we know they do.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/07/2014 08:13 pm
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive (http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive)

It does make one very important point that is there is no agreed theory on how high temperature superconductors work but because they have been replicated so many times we know they do.
There has actually been a paper on high-temp superconductors published recently, explaining how they work. It is supported by computer codes to simulate them as well. Sorry can't find the link at the mo.
Title: Re: EM Drive Developments
Post by: aero on 08/07/2014 08:28 pm
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive (http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive)

It does make one very important point that is there is no agreed theory on how high temperature superconductors work but because they have been replicated so many times we know they do.
There has actually been a paper on high-temp superconductors published recently, explaining how they work. It is supported by computer codes to simulate them as well. Sorry can't find the link at the mo.

Doesn't matter. They worked for a long time before anyone figured out how. EM Drive, if verified to work, is in that stage before anyone has figured how.
Title: Re: EM Drive Developments
Post by: aero on 08/08/2014 12:14 am
Does anyone know if the classic EM Drive has ever been operated with a strain gauge attached to the end plates? That should be an easy way to prove or disprove the pressure idea of operation of the device.
Title: Re: EM Drive Developments
Post by: sanman on 08/08/2014 02:30 am
I, for one, am glad if the NASA team's test results announcement has created a flutter. At least this will encourage more experts to get involved in coming up with either a definitive proof or disproof on this matter. At least one way or the other, the matter can then be settled.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/08/2014 07:04 am
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive (http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive)

It does make one very important point that is there is no agreed theory on how high temperature superconductors work but because they have been replicated so many times we know they do.
There has actually been a paper on high-temp superconductors published recently, explaining how they work. It is supported by computer codes to simulate them as well. Sorry can't find the link at the mo.

Doesn't matter. They worked for a long time before anyone figured out how. EM Drive, if verified to work, is in that stage before anyone has figured how.

They're not comparable because superconductivity never violated any fundamental laws of physics.  The claims about the EmDrive violate fundamental laws of physics.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/08/2014 07:07 am
I, for one, am glad if the NASA team's test results announcement has created a flutter. At least this will encourage more experts to get involved in coming up with either a definitive proof or disproof on this matter. At least one way or the other, the matter can then be settled.

It's already considered settled by mainstream science: there is nothing there.  Mainstream scientists have already looked into the EmDrive years ago and convinced themselves it doesn't work.  That didn't do a thing to discourage its proponents.

Nothing is going to change.  I'll bet you in five years the current state will be exactly what it is today: mainstream science remains convinced there's no effect there, and believers will still insist the effect is real.
Title: Re: EM Drive Developments
Post by: QuantumG on 08/08/2014 07:50 am
It's already considered settled by mainstream science: there is nothing there.  Mainstream scientists have already looked into the EmDrive years ago and convinced themselves it doesn't work.  That didn't do a thing to discourage its proponents.

There's no such thing as "mainstream science".

There's stuff that works and stuff that doesn't. The EMDrive is firmly in the latter category. The day it makes it into the former will be called a "breakthrough".
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/08/2014 08:32 am
here is a slide that kind of shows the set up it's not as good as the video i am looking for but you can see some of the items i mentioned like the contacts the faraday cage the vacuum level and so forth in slide 4:

http://nextbigfuture.com/2010/02/mach-effect-propulsion-research-update.html

Title: Re: EM Drive Developments
Post by: sanman on 08/08/2014 02:04 pm
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive (http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive)

It does make one very important point that is there is no agreed theory on how high temperature superconductors work but because they have been replicated so many times we know they do.
There has actually been a paper on high-temp superconductors published recently, explaining how they work. It is supported by computer codes to simulate them as well. Sorry can't find the link at the mo.

Doesn't matter. They worked for a long time before anyone figured out how. EM Drive, if verified to work, is in that stage before anyone has figured how.

They're not comparable because superconductivity never violated any fundamental laws of physics.  The claims about the EmDrive violate fundamental laws of physics.

I dunno - before people started thinking of Cooper's pairs, it seemed like Superconductivity apparently  violated the need for Work to be done.
Title: Re: EM Drive Developments
Post by: sanman on 08/08/2014 02:06 pm
It's already considered settled by mainstream science: there is nothing there.  Mainstream scientists have already looked into the EmDrive years ago and convinced themselves it doesn't work.  That didn't do a thing to discourage its proponents.

There's no such thing as "mainstream science".

There's stuff that works and stuff that doesn't. The EMDrive is firmly in the latter category. The day it makes it into the former will be called a "breakthrough".

When you're talking about micro-Newtons, it's hard to clearly see what's working or isn't. More experiments can be done to clarify if that thrust is happening or isn't.

Why did they experience the thrust in the opposite direction when they reversed the orientation of the device?
Title: Re: EM Drive Developments
Post by: Star One on 08/08/2014 04:03 pm
This story certainly has spread far and wide it's even appeared in entertainment website forums.

I hope this doesn't cause any kind of backlash in the reputation of NASA if this all proves to be nothing, I know NASA isn't a homogenous whole, we know that but does the public which tends to just see the initials.
Title: Re: EM Drive Developments
Post by: cuddihy on 08/08/2014 04:15 pm
I'm interested by the Paul March speculation about electrostriction of the resonant cavity combined with dieletric causing possible Mach Effect that would explain the thrust without the conservation of mass issues EM drives represent. (Because mass used is external to the device, see the Woodward Effect thread).
Title: Re: EM Drive Developments
Post by: aero on 08/08/2014 04:35 pm
Quote
Why did they experience the thrust in the opposite direction when they reversed the orientation of the device?

I think they measured thrust relative to their measurement device. When they turned the EM thruster 180 degrees relative to their measurement device, it thrusted in the same direction relative to the thruster, but in the reverse direction relative to their measurement device.
Title: Re: EM Drive Developments
Post by: DMeader on 08/08/2014 04:45 pm
I present the following. No personal flames please.
https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6 (https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6)

Title: Re: EM Drive Developments
Post by: Star One on 08/08/2014 05:05 pm
I present the following. No personal flames please.
https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6 (https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6)

Yet another article where it appears that the author does not seem to have read the full report, notice the mention of the null device issue.
Title: Re: EM Drive Developments
Post by: DMeader on 08/08/2014 05:08 pm
Maybe "these article writers" know bad science when they see it.
Title: Re: EM Drive Developments
Post by: Star One on 08/08/2014 05:13 pm
Maybe "these article writers" know bad science when they see it.

Do we know whether the author read the full report rather than the abstract that was initially released?
Title: Re: EM Drive Developments
Post by: aero on 08/08/2014 06:48 pm
Maybe "these article writers" know bad science when they see it.

Do we know whether the author read the full report rather than the abstract that was initially released?

We don't know if he read the full report but we do know that he is quoting from the abstract because he says so.
He also reports the sensitivity of the measurement device to be an order of magnitude worse than all other claims I have seen.

Quote
•The “test” performed at NASA was sensitive to a minimum thrust threshold of about 10-to-15 microNewtons, and the “positive result” claimed detection of somewhere between 30-to-50 microNewtons of thrust.
Title: Re: EM Drive Developments
Post by: Star One on 08/08/2014 07:04 pm

Maybe "these article writers" know bad science when they see it.

Do we know whether the author read the full report rather than the abstract that was initially released?

We don't know if he read the full report but we do know that he is quoting from the abstract because he says so.
He also reports the sensitivity of the measurement device to be an order of magnitude worse than all other claims I have seen.

Quote
•The “test” performed at NASA was sensitive to a minimum thrust threshold of about 10-to-15 microNewtons, and the “positive result” claimed detection of somewhere between 30-to-50 microNewtons of thrust.

Thanks I missed that part but deduced from the rest of the article that it was probably from the abstract.
Title: Re: EM Drive Developments
Post by: GregA on 08/08/2014 11:22 pm
I present the following. No personal flames please.
https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6 (https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6)
The analogy drawn would infer that top scientists have tried to replicate the effect and failed. If that was true I'd side far more with the skeptics.

As it is I believe it needs such research, no?

(Edit: It would be bad science to not do it)
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/08/2014 11:35 pm
I present the following. No personal flames please.
https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6 (https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6)
The analogy drawn would infer that top scientists have tried to replicate the effect and failed. If that was true I'd side far more with the skeptics.

As it is I believe it needs such research, no?

(Edit: It would be bad science to not do it)
Fie! The high Priests of the great infernal entity known as Science have powers to discern anything heretical (in violation of the laws of physics) without even knowing what it's about or if it really does violate the laws of physics because anything weird has to violate the law; it just does . din'tcha know that? Infidel!
Title: Re: EM Drive Developments
Post by: Lars_J on 08/09/2014 05:42 am
I present the following. No personal flames please.
https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6 (https://medium.com/starts-with-a-bang/how-to-fool-the-world-with-bad-science-7a9318dd1ae6)
The analogy drawn would infer that top scientists have tried to replicate the effect and failed. If that was true I'd side far more with the skeptics.

As it is I believe it needs such research, no?

(Edit: It would be bad science to not do it)
Fie! The high Priests of the great infernal entity known as Science have powers to discern anything heretical (in violation of the laws of physics) without even knowing what it's about or if it really does violate the laws of physics because anything weird has to violate the law; it just does . din'tcha know that? Infidel!

...as opposed to the true propulsion breakthrough - wishful thinking?
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/09/2014 06:13 am
i have seen people here pan fusion propulsion.; a likely near term advancement. i have seem them pan VASIMR and other advanced concepts that aren't that unlikely. i have even seen them argue about this or that chemical propulsion scheme being unrealistic or undesireable. so exactly what advanced concepts are non "woo woo?" to everyone's satisfaction? hamster flatulence? what?
Title: Re: EM Drive Developments
Post by: QuantumG on 08/09/2014 06:24 am
i have seen people here pan fusion propulsion.; a likely near term advancement. i have seem them pan VASIMR and other advanced concepts that aren't that unlikely. i have even seen them argue about this or that chemical propulsion scheme being unrealistic or undesireable. so exactly what advanced concepts are non "woo woo?" to everyone's satisfaction? hamster flatulence? what?

Seems to me that everyone wants to talk about the stuff that has no hope of working and no-one ever wants to talk about the stuff that could be made to work with enough money. People used to love talking about solar sails, but now that one has flown (IKAROS) and two more are under development (Sunjammer and LightSail) suddenly no-one is interested anymore. Similarly, few people are terribly interested in talking about nuclear thermal rockets unless they're some impractical fusion contraption, but they were all the rage back in Heinlein's day. Reality has the nasty habit of boring the dreamers.

Title: Re: EM Drive Developments
Post by: Stormbringer on 08/09/2014 06:49 am
i have seen people here pan fusion propulsion.; a likely near term advancement. i have seem them pan VASIMR and other advanced concepts that aren't that unlikely. i have even seen them argue about this or that chemical propulsion scheme being unrealistic or undesireable. so exactly what advanced concepts are non "woo woo?" to everyone's satisfaction? hamster flatulence? what?

Seems to me that everyone wants to talk about the stuff that has no hope of working and no-one ever wants to talk about the stuff that could be made to work with enough money. People used to love talking about solar sails, but now that one has flown (IKAROS) and two more are under development (Sunjammer and LightSail) suddenly no-one is interested anymore. Similarly, few people are terribly interested in talking about nuclear thermal rockets unless they're some impractical fusion contraption, but they were all the rage back in Heinlein's day. Reality has the nasty habit of boring the dreamers.
oh there are plenty of threads about all of those things and countless ones discussing this or that chemical scheme. but the ones that break new ground get a lot of grief. while in my opinion there is no purely chemical scheme that should be classified as advanced. solar sails sure. even though there are a lot of issues that are not easy to fix. plasma sails; ok I'll buy it; but they are leaky. NTRs? sure; but do it already. damn it we have had the knowledge from the 1960s. do it already or shaddap. Fusion? ok. there are some things that may be as few as 5 years off there. This other (what they think of as woo woo or oogly moogly) stuff? low probability of success but huge payoff upon success for not much effort or money. worth discussing. worth low level funding at least. It's not like it hurts funding for other projects. NASA won't launch one less probe because they gave Dr White some modest resources. Not one Orion was hurt in the making of his coil thingy.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/09/2014 06:57 am
Dr White may have in fact gotten his funding by couch fishing in the employee break room chair cushions for all i know. It'd probably cover it.
Title: Re: EM Drive Developments
Post by: Star One on 08/09/2014 09:30 am

i have seen people here pan fusion propulsion.; a likely near term advancement. i have seem them pan VASIMR and other advanced concepts that aren't that unlikely. i have even seen them argue about this or that chemical propulsion scheme being unrealistic or undesireable. so exactly what advanced concepts are non "woo woo?" to everyone's satisfaction? hamster flatulence? what?

Seems to me that everyone wants to talk about the stuff that has no hope of working and no-one ever wants to talk about the stuff that could be made to work with enough money. People used to love talking about solar sails, but now that one has flown (IKAROS) and two more are under development (Sunjammer and LightSail) suddenly no-one is interested anymore. Similarly, few people are terribly interested in talking about nuclear thermal rockets unless they're some impractical fusion contraption, but they were all the rage back in Heinlein's day. Reality has the nasty habit of boring the dreamers.

I think with solar sails it's more their slow pace of development, I am sure we were talking about these back in the eighties but they are still in the early stages of use. Unfortunately the internet seems easily bored with little patience for such projects.
Title: Re: EM Drive Developments
Post by: sanman on 08/09/2014 12:47 pm
i have seen people here pan fusion propulsion.; a likely near term advancement. i have seem them pan VASIMR and other advanced concepts that aren't that unlikely. i have even seen them argue about this or that chemical propulsion scheme being unrealistic or undesireable. so exactly what advanced concepts are non "woo woo?" to everyone's satisfaction? hamster flatulence? what?

Seems to me that everyone wants to talk about the stuff that has no hope of working and no-one ever wants to talk about the stuff that could be made to work with enough money. People used to love talking about solar sails, but now that one has flown (IKAROS) and two more are under development (Sunjammer and LightSail) suddenly no-one is interested anymore. Similarly, few people are terribly interested in talking about nuclear thermal rockets unless they're some impractical fusion contraption, but they were all the rage back in Heinlein's day. Reality has the nasty habit of boring the dreamers.

Even if it seems flimsy, people naturally want to look for some new possibility that can bypass some of the existing strictures that limit spaceflight. "But physics can't be bypassed," you say - well who can claim omniscient knowledge of physics? There may be small exploit opportunities which can be exposed here and there. The fact is that the Quantum Vacuum exists, and it interacts with everything in our world - without violating Conservation of Momentum. Maybe there's a way to push off it without expelling propellant, and maybe this device is demonstrating such an effect. It seems relatively straightforward to attempt a more thorough investigation to provide either proof or disproof that some kind of propulsive effect is happening.

Title: Re: EM Drive Developments
Post by: SteveKelsey on 08/09/2014 04:02 pm
Classical physics ( Newton plus Maxwell) thought it had the universe sewn up and all that was left was details and taxonomy. The view at the time was that it could explain everything, except for one little problem called black body radiation.
Through this small chink in the armour we got quantum mechanics, QED, and eventually the Standard Model. At the time, quantum mechanics was reviled by mainstream authocrats. QM seemed bizarre and irrelevant but something had to explain the odd and ' unscientific' results.

The  Standard Model is hugely successful, and full of holes. http://www.math.columbia.edu/~woit/wordpress/?p=5946&cpage=1
There is no single standard model. The current orthodoxy did not predict and currently cannot explain neutrino mass, entanglement, dark matter, dark energy,accelerated  inflation, the 'cold dark spot' the 'axis of evil'.
How many chinks in the armour of your orthodoxy do you need?
When  the fifty or so 'free parameters' and the need for normalisation have been removed then it might be possible to claim we understand everything. Until that point, experiment carefully and be prepared for surprises.
Title: Re: EM Drive Developments
Post by: frobnicat on 08/09/2014 07:13 pm
It's not that we know everything, but at some energy densities/scales the amount experience confirming the "laws" is so huge than when an experiments claims to see a phenomenon that is in apparent contradiction to those laws without resorting to high energy physics or cosmological scales then it is a sure bet to discard the said experiment at a glance of the summary : the explanation to make said anomaly real and yet compatible with already known results seems far too contrived and unnatural. For instance if someone claims that a fancy shape has slightly more buoyancy than the weight of fluid displaced by such shape, because of the shape, you would surely dismiss the claim without looking the details of the shape and measuring apparatus : Archimedes principle holds and will continue to hold whenever a macroscopic shape is immersed and stand still in a fluid, no matter how old beard physics or how fancy the shape. The good old principles are only broken when going beyond some scope of validity, say newtonian additivity of speed is broken, but only when approaching c, mass conservation is broken but only when taping into nuclear energy levels, the sum of the angles of a triangle is not 180° but only near very heavy compact objects, mass_energy conservation is apparently broken but only on cosmological space-time scales...
So yes we had quite a number of surprises last century or so but the absolute principles of 19th century and before stayed good principles, even as approximations, in their range of validity. What does the EMdrive to reach beyond the range of validity so well established for conservation of energy ? Pushing on vacuum virtual particles sounds nice but vacuum is lorentz invariant so far (it's not like possible violations have not been investigated : http://en.wikipedia.org/wiki/Modern_searches_for_Lorentz_violation (http://en.wikipedia.org/wiki/Modern_searches_for_Lorentz_violation)) and pushing on a lorentz invariant "medium" is not only cheap momentum but basically "free energy", so you cannot claim that without claiming free energy, or some form of transfer of energy from vacuum zero point to the device, that would imply negative energy radiating (contrary to a static casimir effect gap), probably FTL I can't tell, but the point is the whole contemporary physics edifice is crumbling, you can't just borrow a little bit of cheap lorentz invariant momentum and keep the rest untouched.
The whole contemporary physics edifice will probably be extended/replaced some times ahead (and shown to be an approximation or limit to more general principles) but has shown enough validity in a wide range of scales/densities that a device that appear to be well within those ranges be met with utter skepticism by the tenants of the orthodoxy who have a view of the amazing consistency of the whole so far, even if "full of holes". This should be no surprise, this is not a scandal. If the thrust depended clearly on its orientation relative to the stars (aether wind) I guess this would be met with more curiosity as it could relieve the "free energy" aspect.
That said, while I would put my bet with the skeptics, well, you never know, I think this experience's results is worth elucidation, a week clearly is not enough for a small team to check a number of parameters against the values : what if in vacuum, what if changing place of device relative to chamber walls, what if adding another strong magnet somewhere else to the damping one, hell, what if halving the power, we don't even know if the effect would be linear ... would need hundreds measuring sessions. If only for advancing the know how of reliably measuring orthodox low or null thrusts when RF resonant cavities are involved somehow is worth more.
Title: Re: EM Drive Developments
Post by: sanman on 08/09/2014 07:26 pm
For the sake of argument, if the entire electrical input to the test apparatus had been converted into photons, then could the resulting photon rocket have generated comparable levels of force as what was observed?
Title: Re: EM Drive Developments
Post by: CW on 08/09/2014 07:42 pm
I think one has to be careful when calling found physical principles 'laws'. They are not laws in the absolute sense, as in given by 'God', or being the final answer. The only thing we can say about the principles that we found and verified by peer-reviewed experiments up to any given point in time is: To the best of our current knowledge, this is what happens. A very important point to make.

When an experiment seems to 'violate' known physical 'laws', then one could also say instead: That experiment seems to demonstrate a behavior that, to the best of our current knowledge, should not occur. You see the difference that the wording makes? The first paraphrase pretends to be a prosecutor in court, immediately declaring anyone who goes against "that what we know so far" a criminal who 'violates' a 'law'. It is a funny position, because this is what it really says: Something was measured, that seems to go against that which we know to be 'true' - and since it is like that, it must be wrong. This is not how science works. For that to decide, there is peer-review.

I acknowledge that too many revolutionary inventions were claimed, in the biggest part by self-deluded individuals and oftentimes outright frauds. But when science becomes dogma, you can stop your work and go pray in a church. It would be time better spent.

Best regards
Title: Re: EM Drive Developments
Post by: CW on 08/09/2014 07:46 pm
For the sake of argument, if the entire electrical input to the test apparatus had been converted into photons, then could the resulting photon rocket have generated comparable levels of force as what was observed?

That is an excellent question. I think that the difference lies in the fact that in a photon rocket, each photon that imparts impulse to the rocket, only gets reflected exactly one time. In a superconducting high-Q resonant cavity, the photons get reflected e.g. a billion times until they get lost. So, my best guess is: No, the levels of force should not be comparable at all, since the photons can impart an impulse to a compact cavity many millions or even billions of times per second. Quite a hefty multiplier.
Title: Re: EM Drive Developments
Post by: sanman on 08/09/2014 07:53 pm
For the sake of argument, if the entire electrical input to the test apparatus had been converted into photons, then could the resulting photon rocket have generated comparable levels of force as what was observed?

That is an excellent question. I think that the difference lies in the fact that in a photon rocket, each photon that imparts impulse to the rocket, only gets reflected exactly one time. In a superconducting high-Q resonant cavity, the photons get reflected e.g. a billion times until they get lost. So, my best guess is: No, the levels of force should not be comparable at all, since the photons can impart an impulse to a compact cavity many millions or even billions of times per second. Quite a hefty multiplier.

That's what I figured the response would be - but doesn't Conservation of Momentum apply to a resonant cavity, no matter how many times photons bounce back and forth inside it? If those were pingpong balls bouncing back-and-forth inside a cavity, we'd say there was no net momentum imparted to the apparatus from all their bouncing, because of Conservation of Momentum.

So if the force level observed is greater than what a photon rocket would hypothetically create, then doesn't that imply that there's more going on here than what traditional physics would suggest? (eg. Q-thruster, some interaction with Quantum Vacuum, etc)
Title: Re: EM Drive Developments
Post by: aero on 08/09/2014 08:15 pm
For the sake of argument, if the entire electrical input to the test apparatus had been converted into photons, then could the resulting photon rocket have generated comparable levels of force as what was observed?

That is an excellent question. I think that the difference lies in the fact that in a photon rocket, each photon that imparts impulse to the rocket, only gets reflected exactly one time. In a superconducting high-Q resonant cavity, the photons get reflected e.g. a billion times until they get lost. So, my best guess is: No, the levels of force should not be comparable at all.

No. I already did that calculation. The problem with that is the jet energy which would result. If the force, F = mdot * Ve were caused by photons moving at the speed of light, then mdot = 3.04E-13 kg/s and the jet energy, E= mdot * Ve^2/2 = .5*F*Ve . That gives E =  13,670.54 J/s or watts for a drive power of 17 watts. So conservation of energy is violated.

I have imagined a different failure mode. I hope i'ts wrong because I really want the EM thruster to be real, and I wonder how an outfit with "Aeronautics" in its name could make such a mistake, but consider this.

The EM thruster has never been tested in vacuum, and they all have been leaky, that is, total air pressure inside and outside is equal and equals atmospheric. Imagine then that some mechanism sets up an air circulation within the EM thruster. Circulating air moves with some velocity V across the inside of the large end of the thruster, recirculating around the open cavity past the small end. Air pressure outside the large end = Pt, total pressure but static air pressure inside the large end, Ps = Pt -q and q = 0.5* rho*V^2.

I ran the numbers assuming 140 mm diameter, uniform velocity and sea level air density. The force of air pressure equals the thrust force claimed when V = ~0.1 m/s. The actual number Excel calculated was 95.74677721 mm/s.

I hope you can gently shoot down this idea.
Title: Re: EM Drive Developments
Post by: CW on 08/09/2014 08:19 pm
For the sake of argument, if the entire electrical input to the test apparatus had been converted into photons, then could the resulting photon rocket have generated comparable levels of force as what was observed?

That is an excellent question. I think that the difference lies in the fact that in a photon rocket, each photon that imparts impulse to the rocket, only gets reflected exactly one time. In a superconducting high-Q resonant cavity, the photons get reflected e.g. a billion times until they get lost. So, my best guess is: No, the levels of force should not be comparable at all, since the photons can impart an impulse to a compact cavity many millions or even billions of times per second. Quite a hefty multiplier.

That's what I figured the response would be - but doesn't Conservation of Momentum apply to a resonant cavity, no matter how many times photons bounce back and forth inside it? If those were pingpong balls bouncing back-and-forth inside a cavity, we'd say there was no net momentum imparted to the apparatus from all their bouncing, because of Conservation of Momentum.

So if the force level observed is greater than what a photon rocket would hypothetically create, then doesn't that imply that there's more going on here than what traditional physics would suggest? (eg. Q-thruster, some interaction with Quantum Vacuum, etc)

All that we can IMHO say so far is, that if the measurements are confirmed under better controlled conditions as well, that by some hitherto unknown physical interaction an imbalance in momentum transfer is produced and that the photons, which are reflected N times in this resonant cavity on the desired surface, get N times the opportunity to do a momentum transfer. If this really works, then it would make sense that, as Shawyer claims, such a drive would be the perfect means to produce a static force that counteracts the gravitational force of any kind of airborne objects.

There is one thing I find a bit curious. Momentum is defined as p = m*v . Now, if the drive were just to produce a force to counteract Earth's gravity, in how far is impulse conservation not adhered to? Above formula states clearly, that you need to have some relative speed going on for any kind of measurable momentum. No movement - no impulse. I mean, it is IMHO comparable to a book standing on a table. No-one would imply that the book were to 'violate' impulse conservation in any way ;) . So, what's going on here?

Regards
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/09/2014 08:42 pm
For the sake of argument, if the entire electrical input to the test apparatus had been converted into photons, then could the resulting photon rocket have generated comparable levels of force as what was observed?

That is an excellent question. I think that the difference lies in the fact that in a photon rocket, each photon that imparts impulse to the rocket, only gets reflected exactly one time. In a superconducting high-Q resonant cavity, the photons get reflected e.g. a billion times until they get lost. So, my best guess is: No, the levels of force should not be comparable at all.

No. I already did that calculation. The problem with that is the jet energy which would result. If the force, F = mdot * Ve were caused by photons moving at the speed of light, then mdot = 3.04E-13 kg/s and the jet energy, E= mdot * Ve^2/2 = .5*F*Ve . That gives E =  13,670.54 J/s or watts for a drive power of 17 watts. So conservation of energy is violated.

I have imagined a different failure mode. I hope i'ts wrong because I really want the EM thruster to be real, and I wonder how an outfit with "Aeronautics" in its name could make such a mistake, but consider this.

The EM thruster has never been tested in vacuum, and they all have been leaky, that is, total air pressure inside and outside is equal and equals atmospheric. Imagine then that some mechanism sets up an air circulation within the EM thruster. Circulating air moves with some velocity V across the inside of the large end of the thruster, recirculating around the open cavity past the small end. Air pressure outside the large end = Pt, total pressure but static air pressure inside the large end, Ps = Pt -q and q = 0.5* rho*V^2.

I ran the numbers assuming 140 mm diameter, uniform velocity and sea level air density. The force of air pressure equals the thrust force claimed when V = ~0.1 m/s. The actual number Excel calculated was 95.74677721 mm/s.

I hope you can gently shoot down this idea.
i dunno if this EM thruster has been tested in vacuum or not but I know that Dr Woodward's version of this thing has been tested in vacuum.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/09/2014 08:45 pm
Dr Woodward's slide shows a vacuum strength of 5.0 milli Tor.
Title: Re: EM Drive Developments
Post by: Hanelyp on 08/09/2014 08:52 pm
That's what I figured the response would be - but doesn't Conservation of Momentum apply to a resonant cavity, no matter how many times photons bounce back and forth inside it? If those were pingpong balls bouncing back-and-forth inside a cavity, we'd say there was no net momentum imparted to the apparatus from all their bouncing, because of Conservation of Momentum.

So if the force level observed is greater than what a photon rocket would hypothetically create, then doesn't that imply that there's more going on here than what traditional physics would suggest? (eg. Q-thruster, some interaction with Quantum Vacuum, etc)
The forces inside a resonant chamber should be balanced, except for the feed point.  The transmission cable connecting the resonant chamber to the microwave generator is carrying momentum along with the energy.  If there's a poor match between feed line and resonator, photons bouncing back and forth may carry momentum far in excess of a single transfer of the energy.  This can be a problem for experimental integrity if the microwave generator is not on the force balance.
Title: Re: EM Drive Developments
Post by: aero on 08/10/2014 03:49 am
Back on the previous page, I pose a situation where air circulation inside the thruster caused the pressure difference measured as thrust. http://forum.nasaspaceflight.com/index.php?topic=29276.msg1241487#msg1241487 (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1241487#msg1241487)

It occurs to me that this idea does not hold water because it was reported that with the dielectric RF resonator removed, the measurement was zero to the system precision. If air circulates with the resonator installed, then it should also circulate (to some extent) with the resonator removed, shouldn't it?
Title: Re: EM Drive Developments
Post by: GregA on 08/10/2014 05:20 am

The forces inside a resonant chamber should be balanced, except for the feed point.  The transmission cable connecting the resonant chamber to the microwave generator is carrying momentum along with the energy.  If there's a poor match between feed line and resonator, photons bouncing back and forth may carry momentum far in excess of a single transfer of the energy.  This can be a problem for experimental integrity if the microwave generator is not on the force balance.
The null test should have also had similar error?
Title: Re: EM Drive Developments
Post by: su27k on 08/10/2014 03:18 pm
Dr White's presentation on this recent work: http://new.livestream.com/accounts/4950775/events/3217776/videos/58616741, starts after 52 mins.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/11/2014 04:09 am
thanks for the link. i will actually watch the thing through later but from the description you gave it seems nothing new has happened since his last recorded presentation.


i was just thinking...

if Mach's principle worked via advanced waves and retarded waves as opposed to quantum flux or one of the other ideas... would that not mean that you also have an ansible because you could then modulate a mach drive so as to encode information in the advanced and retarded waves?
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/11/2014 08:45 am
i think Dr White said more about the EM drive this time. including details of the test rig power, measurements, calibration and so forth. if you can bear the crappy sound quality and the guy apparently expiring from TB in the background there is a lot in there to satisfy critics.

on the warp thing: his teams is quantifying and accounting for false signals. and has set up type of test for the warp thing involving time of flight measurements for a second laser beam. these measurement regimes take place at the same time so that false positives that affect one method generally don't affect the other.
Title: Re: EM Drive Developments
Post by: Hanelyp on 08/12/2014 05:11 pm

The forces inside a resonant chamber should be balanced, except for the feed point.  The transmission cable connecting the resonant chamber to the microwave generator is carrying momentum along with the energy.  If there's a poor match between feed line and resonator, photons bouncing back and forth may carry momentum far in excess of a single transfer of the energy.  This can be a problem for experimental integrity if the microwave generator is not on the force balance.
The null test should have also had similar error?
Not if the dummy load presented a greatly different impedance than the active resonator.
Title: Re: EM Drive Developments
Post by: Star One on 08/12/2014 07:42 pm
Reading around in various places there seems to be quite a bit of growing support for thinking the Mach effect is at work here and at the same time Dr White's explanation seems to be under be a good deal of scrutiny of close scrutiny.
Title: Re: EM Drive Developments
Post by: GregA on 08/12/2014 09:42 pm

Not if the dummy load presented a greatly different impedance than the active resonator.
Okay, at least I understand your thinking - that there was an error in measurement, and the control for it probably didn't work.
Title: Re: EM Drive Developments
Post by: peter-b on 08/12/2014 09:49 pm
The EMDrive folks approached my friends in the propulsion group at SSC about doing some experiments in the SSC propulsion lab. The EMDrive people refused to allow their drive to be tested using SSC's extremely sensitive laser thrust balance, and as a result the group told them to go elsewhere.

I've spoken a few of the propulsion group about the latest results: the consensus is poor methodology and/or experimental error.
Title: Re: EM Drive Developments
Post by: aceshigh on 08/12/2014 09:51 pm
Reading around in various places there seems to be quite a bit of growing support for thinking the Mach effect is at work here and at the same time Dr White's explanation seems to be under be a good deal of scrutiny of close scrutiny.

links to these discussions would be welcome :)
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/12/2014 10:16 pm
Judging from the comments here, people don't seem to have much respect for just how HARD it is to get a truly solid result from a small signal and just how EASY it is to fool oneself. This is why we make scientists go to grad school and do real research. Getting VALID results from noisy data is a Herculean task, and at every single step, there's a temptation to interpret your noisy data as confirming your expectations or to remove "outliers" that can subtly tilt the odds in favor of your desired outcome. No outright fraud is necessary for this to happen! That's a common mistake that non-scientists make: if someone gets a false positive, it must be because of intentional fraud, the naive may say. But no, it's much subtler than that. Teasing out signals in noisy data is so easy to screw up. An enormous amount of self-skepticism is necessary or you will produce non-reproducible results (which are ultimately shown to be in error).

Or, in the words of Richard Feynman, "The first principle is that you must not fool yourself, and you are the easiest person to fool!"

Nature does not give up her secrets easily, and she doesn't care how much you want a certain thing to be true.


I would literally cut my arm off if doing so would make these results valid. But chances are, it's just a false positive. From a Bayesian perspective, because conservation of momentum and energy are so well established (and ways to keep conservation with these results equally unlikely), even a positive, "statistically significant" result (p<0.05) WITHOUT systematic error would almost certainly still be a false positive, by an enormous margin.
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/12/2014 10:44 pm
In undergrad: "Huh, didn't work as I thought it would! What did I do wrong?..."
In grad school:"Huh, this result actually confirms my hypothesis! What did I do wrong?..."
Title: Re: EM Drive Developments
Post by: Star One on 08/12/2014 11:49 pm
Reading around in various places there seems to be quite a bit of growing support for thinking the Mach effect is at work here and at the same time Dr White's explanation seems to be under be a good deal of scrutiny of close scrutiny.

links to these discussions would be welcome :)

Unfortunately quite a bit is on the Polywell forum & I am unsure about linking to that now as it heavily features what appears to be a banned member from here?
Title: Re: EM Drive Developments
Post by: aero on 08/13/2014 12:29 am
Perhaps a different view is that on that forum there is a member loudly promoting his/her long held favorite theory. As he has been for a long time, loudly and often. He has won over a few converts.

I've no opinion about ME theory or the Woodward effect but I wouldn't promote it as "One size fits all." Neither would I say that there is no chance of it fitting as no one really knows.
Title: Re: EM Drive Developments
Post by: GregA on 08/13/2014 01:02 am
Can anyone shed some light on the Chinese research done a couple of years ago, finding a greater effect, and flaws in that?
Title: Re: EM Drive Developments
Post by: aero on 08/13/2014 01:46 am
Can anyone shed some light on the Chinese research done a couple of years ago, finding a greater effect, and flaws in that?

A professional English translation of the paper Net thrust measurement of propellantless microwave thrusters*.

http://www.emdrive.com/yang-juan-paper-2012.pdf (http://www.emdrive.com/yang-juan-paper-2012.pdf)
Title: Re: EM Drive Developments
Post by: cuddihy on 08/13/2014 03:23 am

I would literally cut my arm off if doing so would make these results valid. But chances are, it's just a false positive. From a Bayesian perspective, because conservation of momentum and energy are so well established (and ways to keep conservation with these results equally unlikely), even a positive, "statistically significant" result (p<0.05) WITHOUT systematic error would almost certainly still be a false positive, by an enormous margin.

A third possibility (remote but more likely than violation of conservation of mass/momentum) is that of a non-confirming true positive -- that is a result that is not due to some kind of error in experiment but that is attributable to something (new) other than the tested theory. This is what those speculating on unintended Woodward effect as the cause of the thrust are pushing. It offers a (sounder) theoretical basis for "propellantless" thrust that does not require facial violation of established physics, only the swallowing of incredible results.

Another example of this type of possibility would be a never-before-observed directional coupling mechanism between the vacuum chamber and the feed lines... Some experiment failures are interesting in their own right.
Title: Re: EM Drive Developments
Post by: Star One on 08/13/2014 06:28 am
Perhaps a different view is that on that forum there is a member loudly promoting his/her long held favorite theory. As he has been for a long time, loudly and often. He has won over a few converts.

I've no opinion about ME theory or the Woodward effect but I wouldn't promote it as "One size fits all." Neither would I say that there is no chance of it fitting as no one really knows.

Thanks that's probably not a bad way of putting it on second thoughts. I don't know this person's history but it certainly seems a rather dominant poster on there.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/13/2014 07:25 am
well if  the ME idea turns out to be valid there might be an Ansible in it for free. :)

of course accepting the ME idea there are several proposed mechanisms by which it could work. but if the ME is valid and it turns out to involve Freeman's advanced and retarded wave explanation then because inertia would be a result of communication with distal parts of the universe then you should be able to modulate an ME device output and send encoded information.
Title: Re: EM Drive Developments
Post by: Star One on 08/13/2014 10:11 am
well if  the ME idea turns out to be valid there might be an Ansible in it for free. :)

of course accepting the ME idea there are several proposed mechanisms by which it could work. but if the ME is valid and it turns out to involve Freeman's advanced and retarded wave explanation then because inertia would be a result of communication with distal parts of the universe then you should be able to modulate an ME device output and send encoded information.

I am not sure that's a very good idea to send out info to who knows what & where.:)

http://news.bbc.co.uk/1/hi/8642558.stm
Title: Re: EM Drive Developments
Post by: frobnicat on 08/13/2014 10:59 am
Another example of this type of possibility would be a never-before-observed directional coupling mechanism between the vacuum chamber and the feed lines... Some experiment failures are interesting in their own right.

Making a fully rotationally symmetric apparatus would eliminate a whole range of possible failure modes : vertical cylindrical vacuum chamber with co-axial axis of rotation for the horizontal balance beam, thruster resonant cavity mounted on one end of the beam and counter weight at the other end (or better yet another identical fed resonant cavity). Ideally waveguide(s) injecting RF power and measuring reflecting waves also co-axial (cylindrical inlet freely rotating inside fixed feed line, with 0 friction small gap<<wavelength between). Any displacement would leave the whole moving system in an equivalent geometric situation relative to vacuum chamber frame of reference. Remaining failure modes, if apparent thrust is observed, would imply momentum transfers "transverse" from reference frame surfaces : my guess it's not impossible but much weaker effects that pushing orthogonally with pressures/varying volumes, assuming leaks or feed lines couplings (fields in varying volumes between moving parts and fixed parts).

For levels of power/thrust ratios of the order reported by the Chines experiment or R. Shawyer it should even be relatively easy to have a freely rotating beam with residual torque resistance much below the torque given by such net thrust. Let it accelerate and observe the thrust relative to speed...

One question : what is the difference between a cavity that is fed at its resonant frequency and a cavity that is fed with a different frequency, at same power levels ? My maybe incorrect understanding is that when resonance is present the different waves bouncing back and forth happen to "synchronize" in a standing wave where anti-nodes exhibit amplitudes Q (quality factor) times stronger than the incoming excitation. But from a photon point of view, you are just throwing photons in a cavity and the collective behaviour is just the sum of individual behaviours : whatever frequency (in a wide range) the photons will bounce back and forth on the order of Q times before being absorbed (dissipated) on walls, regardless of resonance or not. So for a given power input and given Q, EM energy density is the same, resonance or not, only the amplitudes don't sum up well when not resonant, please tell if wrong. My point is, if thrust effect is real it can't be about just classical linear EM waves bouncing back and forth in asymmetrical cavity : resonance wouldn't change the effect, while all of the proponents seem to imply resonance is central with their experiments.

Maxwell equations are linear, same with the ohmic losses (at skin depth in the cavity's walls). Specifically resonance would be necessary to reach fields strong enough to enter nonlinear effects ranges ? How the reached resonant amplitudes compares with known limits of linearity, dielectric strength for instance ?

Thank Aero for the link to english translation of the Chinese paper.
Title: Re: EM Drive Developments
Post by: aceshigh on 08/14/2014 06:02 am
Perhaps a different view is that on that forum there is a member loudly promoting his/her long held favorite theory. As he has been for a long time, loudly and often. He has won over a few converts.

I've no opinion about ME theory or the Woodward effect but I wouldn't promote it as "One size fits all." Neither would I say that there is no chance of it fitting as no one really knows.

Thanks that's probably not a bad way of putting it on second thoughts. I don't know this person's history but it certainly seems a rather dominant poster on there.

he is not a dominant poster, and he fought with many forumers there. BUT we should not judge his ideas by his personality.

plenty of forumers there ARE on Woodwards emailing list.


Also bear in mind there is a long long Mach Effect thread on that forum, where Paul March (who works with Dr White) and is known here on NSF as Stardrive) had many posts and long discussions.


93143 can talk about the situation too, since he is also a long time poster at Talk Polywell and here at NSF.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/14/2014 07:00 am
hey, there is a new article at new scientist on CERN's hunt for monopoles. i am not a subscriber so i cannot access the full article. but if they find monopoles and can reproduce them in large numbers you could see materials that won't melt if you dunk them into a star or detonate a nuke on top of it. probably good stuff for rocket nozzles and high temperature and pressure reactor parts. even before that though exo-thermal reactions between monopole atoms would pack the power of a nuclear reaction in normal matter. if there were transparent monopole substances/elements (for example; monopole versions of silicon or quartz) you could have a window that is unbreakable even with relativistic impacts.
Title: Re: EM Drive Developments
Post by: Star One on 08/14/2014 09:22 am
Perhaps a different view is that on that forum there is a member loudly promoting his/her long held favorite theory. As he has been for a long time, loudly and often. He has won over a few converts.

I've no opinion about ME theory or the Woodward effect but I wouldn't promote it as "One size fits all." Neither would I say that there is no chance of it fitting as no one really knows.

Thanks that's probably not a bad way of putting it on second thoughts. I don't know this person's history but it certainly seems a rather dominant poster on there.

he is not a dominant poster, and he fought with many forumers there. BUT we should not judge his ideas by his personality.

plenty of forumers there ARE on Woodwards emailing list.


Also bear in mind there is a long long Mach Effect thread on that forum, where Paul March (who works with Dr White) and is known here on NSF as Stardrive) had many posts and long discussions.


93143 can talk about the situation too, since he is also a long time poster at Talk Polywell and here at NSF.

I meant dominant in the sense of being very active, poor choice of phrase perhaps by me.

Monopoles article as mentioned above.

http://www.newscientist.com/article/mg22329820.600-pole-alone-the-quest-for-a-north-without-a-south.html

I am subscriber but because of the paywall I cannot post the rest of it.
Title: Re: EM Drive Developments
Post by: sghill on 08/14/2014 04:21 pm
well if  the ME idea turns out to be valid there might be an Ansible in it for free. :)

of course accepting the ME idea there are several proposed mechanisms by which it could work. but if the ME is valid and it turns out to involve Freeman's advanced and retarded wave explanation then because inertia would be a result of communication with distal parts of the universe then you should be able to modulate an ME device output and send encoded information.

I am not sure that's a very good idea to send out info to who knows what & where.:)

http://news.bbc.co.uk/1/hi/8642558.stm

That Ansible would help explain the Fermi Paradox! 

I have a general magnetism question that this thread has made pop into my mind.  How can magnets attract or repel each other indefinitely without expending energy? If I put two ring magnets on a pole with the same pole facing each other, the magnet on the top will float above the magnet on the bottom, the repulsive force overcoming gravity, and the equilibrium distance between the two is determined by the field strength of the magnets. All that is well and good, but how does this happen without the repulsive (or attractive) effect fading over time and the magnets getting warm or otherwise emitting photons?  In other words, the floating magnet is continually resisting an accelerative force due to gravity, so it (and the other magnet) has to expend energy to counter gravity for it to stay afloat.  So where does that continual input energy come from? Even if it's at the nuclear level, there has to be an expenditure somewhere in order to negate gravitational acceleration.
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/14/2014 06:56 pm
Conceptually, it's the same as a book lying on a desk. Desk is exerting a force on the book to counteract gravity but no energy is expended. Energy is force times distance. If a force is exerted on an object but the object doesn't move, no energy need be expended.
Title: Re: EM Drive Developments
Post by: JasonAW3 on 08/14/2014 07:02 pm
well if  the ME idea turns out to be valid there might be an Ansible in it for free. :)

of course accepting the ME idea there are several proposed mechanisms by which it could work. but if the ME is valid and it turns out to involve Freeman's advanced and retarded wave explanation then because inertia would be a result of communication with distal parts of the universe then you should be able to modulate an ME device output and send encoded information.

I am not sure that's a very good idea to send out info to who knows what & where.:)

http://news.bbc.co.uk/1/hi/8642558.stm

That Ansible would help explain the Fermi Paradox! 

I have a general magnetism question that this thread has made pop into my mind.  How can magnets attract or repel each other indefinitely without expending energy? If I put two ring magnets on a pole with the same pole facing each other, the magnet on the top will float above the magnet on the bottom, the repulsive force overcoming gravity, and the equilibrium distance between the two is determined by the field strength of the magnets. All that is well and good, but how does this happen without the repulsive (or attractive) effect fading over time and the magnets getting warm or otherwise emitting photons?  In other words, the floating magnet is continually resisting an accelerative force due to gravity, so it (and the other magnet) has to expend energy to counter gravity for it to stay afloat.  So where does that continual input energy come from? Even if it's at the nuclear level, there has to be an expenditure somewhere in order to negate gravitational acceleration.

Actually, I think all the Aliens out there are mad at us for not trying to contact them sooner...  Kind of like when you don't call your family for a while and they give you the cold shoulder...
Title: Re: EM Drive Developments
Post by: frobnicat on 08/14/2014 10:04 pm
Conceptually, it's the same as a book lying on a desk. Desk is exerting a force on the book to counteract gravity but no energy is expended. Energy is force times distance. If a force is exerted on an object but the object doesn't move, no energy need be expended.

Thanks for responding!

How can a force be exerted without expending energy? (serious question). If I hold my fat aunt above my head and she doesn't move, I'm still using energy to exert a force to counter gravity.  Aren't atoms and particles doing the same?  Inversely, can't I also expend energy to squeeze them together until the atoms can no longer resist fusing and then lots of their energy is released.  Is the energy expended still zero until the whole thing collapses?

As Robotbeat states, no energy need be expended, that don't mean any "agency" that holds a force (on an object that doesn't move relative to the agent exerting said force) wont dissipate energy : muscles do use metabolic energy even when they are not doing useful work, as is the case when contracting without displacement. The same would apply for a DC electric motor exerting a torque on a stuck shaft, no displacement implies no useful work, yet the motor is dissipating energy. In both cases the whole energy used by the agent is completely converted to heat, while if displacement is done in the same direction as force then at least a fraction of the expended energy goes into useful work, like for instance gaining height (more gravitational potential energy for the pushed object) or speed (more kinetic energy). Said useful work's corresponding energy can be recovered later, that is converted to other forms...

A solid "passive" object like a chair can hold a force on an object without expending any energy but it cant follow displacement in the direction of force, if aunty is an inch above chair then chair is no longer exerting force on aunty : no energy needed to exert force but no useful work can be done. In general : useful work is less or equal to expended energy. No expended energy implies no useful work, useful work implies expended energy, but it's possible to expend energy without useful work (in which case efficiency is 0, and expended energy is dissipated as heat).

Like with a chair, you could keep two nucleus (say two deuterium) at a close distance by applying a static force opposite to the electrostatic repulsion, without expending any energy, but the electrostatic repulsion wouldn't get tired because it's not expending energy either. On the other hand to take two nucleus from the "long" distance you find them and get them to the closer distance you wish, your squeezing force has to exert through a displacement : that needs expending energy. More energy can be recovered when the two nucleus fuse together (strong nuclear force bigger than electrostatic repulsion at close ranges) but that's another story, you have to invest initial energy to get (not to keep) nucleus close first.

Now the confusing thing at microscopic scale is that there is no such thing as a solid object. Solidity is a consequence of chemical bonds : electromagnetic forces mediated by constant exchanges of photons. That don't sound really static and yet no net expenditure of energy is needed when no displacement is done overall. Even if talking about inflatable chair and all gas atoms keep moving around, they support aunty "for free" as far as energy is concerned, they don't get tired.
Title: Re: EM Drive Developments
Post by: SteveKelsey on 08/14/2014 11:26 pm
Regrettably coercivity dashes all hopes.

http://en.m.wikipedia.org/wiki/Coercivity

It is a cruel universe
Title: Re: EM Drive Developments
Post by: Req on 08/15/2014 02:06 am
Regrettably coercivity dashes all hopes.

http://en.m.wikipedia.org/wiki/Coercivity

It is a cruel universe

So coercivity seems to imply that there is a fixed amount of time that it will levitate the other magnet, and whatever is actually responsible for the levitation will dissipate as heat over time.  Right?  No magic involved, something is being spent.
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/15/2014 02:11 am
Not necessarily if it's a superconductor! :)
Title: Re: EM Drive Developments
Post by: frobnicat on 08/15/2014 09:53 am
Regrettably coercivity dashes all hopes.

http://en.m.wikipedia.org/wiki/Coercivity

It is a cruel universe

So coercivity seems to imply that there is a fixed amount of time that it will levitate the other magnet, and whatever is actually responsible for the levitation will dissipate as heat over time.  Right?  No magic involved, something is being spent.

Again : theory (classical or quantum mechanics) states that it is not necessary to spend energy to hold a force in a geometrically static (no displacement) system, even when the force is at distance (and at microscopic scale even a solid contact is in fact force at distance). Not necessary don't mean that any way to achieve such force won't show some level of power loss or wear or creep deformation or weakening. A block of iron supporting an object of one pound will exert a force (against the weight of object) and maintain its altitude forever without spending anything : no magic involved, force without displacement needs no net energy expenditure. Force is not energy. The "forever" is true on cosmological scales, at least a few billion years, after what dark energy could maybe start to rip space-time apart at mundane scales. Resting without spending energy, quite literally until the end of time : no magic involved.

There is no theoretical reasons (basic principles) why a magnetically "levitating" object would require more energy that an object resting on a solid block, actually the object is also "levitating" in the later case, only a few angstroms above the support.
See "contact force" on wikipedia :
Quote
The interaction between macroscopic objects can be roughly described as resulting from the electromagnetic interactions between protons and electrons of the atomic constituents of these objects. Everyday objects do not actually touch each other; rather, contact forces are the result of the interactions of the electrons at or near the surfaces of the objects (exchange force).

So there is nothing much special between just resting on a solid object (no energy needed, forever) and resting on a magnetic repulsion from a permanent magnet at longer distance : theoretically no energy needed. If you keep the fields well below coercivity limits and use appropriate materials this is also possible in practice. Demagnetization occurs mainly not as a function of time but of external magnetic field strength, that is below a certain level of external field the demagnetization time approaches infinity.
http://www.magmamagnets.com/permanent-magnet-stability (http://www.magmamagnets.com/permanent-magnet-stability)
Quote
The effect of time on modern permanent magnets is minimal. .../... Over 100,000 hours, these losses are in the range of essentially zero for Samarium Cobalt materials...
Also for a very very long functioning, some environmental radiation can wear the magnets :
Quote
SmCo exhibits significant demagnetization when irradiated with a proton beam of 10^9 to 10^10 rads
. I guess cumulative radiations would also discharge the current loops in a superconductor...

So, granted the opposite magnets levitation is more difficult to achieve and "fragile" than the levitation of just resting on a solid support but in both cases spent energy is 0, without magic involved. Of course if you used (not superconducting) electromagnets instead of permanent magnets then maintaining the force would need constant energy flow (power), but not out of basic principles fatality, just as a consequence of a technological choice. It's always possible to use more energy than needed.
Title: Re: EM Drive Developments
Post by: Mulletron on 08/16/2014 07:14 am
My interpretation of the Nasa description of the test campaigns tells me that the shape of the thruster and the q factor make no difference. The presence of the dielectric and the electromagnetic flux are key. If it really works, it's due to photon momentum transfer described by Minkowski et al. Also describing quantum vacuum particle pair production / annihilation as a plasma is gobbledygook. The quantum vacuum is key here though, as it is the only way I can think of to bring about an asymmetry which would allow thrust to occur, and not have a violation of laws of thermodynamics. Just as the qv is responsible for the lamb shift observed in a shift in the energy levels of hydrogen atom atoms, I think the thruster may work in a similar but reverse way. A net thrust cannot occur via photon momentum transfer within the same frame of reference, but it could if energy could be transferred to another frame of reference. No violation of laws, net thrust. If this works, it could be describing a key asymmetry which could point to new physics. There are a lot of papers describing mechanisms similar to this, check out works by Feigel, Dewar, Millis (Nasa), Brito. I think this thruster would work best if it were just a tube with a dielectric slug of PVDF instead of PTFE, pumped with a huge amount of wideband RF white noise.
Title: Re: EM Drive Developments
Post by: Mulletron on 08/16/2014 09:23 am
Since the emdrive isn't expelling anything, there isn't anything in our frame of reference to allow a symmetrical reaction to occur, like a rocket blast creating an equal and opposite reaction, giving you thrust. If it were expelling something, like the radiation it is producing, it would merely be a photon thruster. But it isn't expelling anything, so imagine a rocket with the cone capped off, no reaction.  This is where the dielectric comes in, it is providing a vector through to another frame of reference, that of the qv (composed of the ground states of all particles, all fields, all frequencies, which luckily fluctuates according to the uncertainty principle) and most importantly, another frame of reference. There the photons can interact and transfer some of their energy/momentum only fleetingly and achieve thrust. Fleetingly in that there is a very low probability of any interaction whatsoever. The dielectric serves to up a photons chances of interacting with the qv, nothing more. Some geometries and materials allow for repulsive Casimir effects. Just shooting RF out the back of the thruster will interact with something once in a very long while and give you a tiny bit of thrust. It looks like the dielectric ups those chances of an interaction some 16000 times. In the end everything is conserved, the energy is transferred to another frame of reference, reacts, and thrust occurs against the very weakly interacting qv. This isn't a reactionless thruster. So to improve the design, we need to improve our chances of interacting with the qv, which has a very low probability wave function, hence a low probability of ever being interacted with. Advanced materials, like PVDF (love this stuff), coupled with a very high power rf field at a frequency where the dielectric constant of the material is highest (permittivity peaks and dips at different frequencies), taking into account that the higher the frequency, the higher the photon energy. So using the highest frequency possible where the dielectric constant is highest, coupled with noisy high rf wideband power should be the ticket. #IFLScience
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/16/2014 09:34 pm
it could if energy could be transferred to another frame of reference. No violation of laws, net thrust.

Frames of reference aren't physical entities.  You can't transfer energy or momentum or anything from one frame of reference to another.

Frames of reference are just different ways of observing exactly the same physical events.  Think of them as places observers could be to watch.  Relativity tells us that exactly the same rules are followed in all inertial frames of reference.

Talking about transferring energy to another frame of reference doesn't make any more sense than saying I can accelerate by pushing against my own shadow.  It's like saying I'm going to work on extracting energy from the number 3.

Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/16/2014 09:51 pm
The CMB frame of reference is a physical entity.
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/16/2014 10:11 pm
The CMB frame of reference is a physical entity.
says some guy on the Internet?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/16/2014 10:12 pm
Says me, yes.
Think about it carefully.
When you have, get back to me.
 :)
Title: Re: EM Drive Developments
Post by: frobnicat on 08/17/2014 12:04 am
The mean local velocity (or momentum) vector of a relatively homogeneous flow of real particles (known or unknown) can define a local frame of reference, and you can conceivably transfer momentum from a device to such a flow, would that phrase be more accurate ? Known flows include solar wind, photon flows near hot objects, photon flow of the CMB, photons mediating planetary magnetic fields, wind (in atmospheres)... Undetected but suspected flow would include dark matter, cosmic neutrino background, gravitational waves . Other possible unknown fields are well, unknown. Obviously inside the walls of a vacuum chamber in an earth lab a number of those flows are ruled out.

Virtual particles of the vacuum on the other hand don't appear to define a frame of reference, though they might define an "inertial reference" (tm) : Casimir effect for instance don't show different behaviour on different inertial frames (Lorentz invariant, no reference of what would be an absolute 0 speed relative to vacuum) while dynamical Casimir effect allows to measure acceleration in absolute terms (can tell an absolute 0 acceleration relative to it). Don't know when gravity comes into play but in a flat space-time it seems hard to push on such a "medium" without breaking conservation of energy because of acquiring a reaction mass always at 0 speed relative to it (cost don't depend on a varying relative speed as would be the case with a real flow). So if energy is gained it would imply either to abandon conservation (and time invariance) or to tap into vacuum zero-point energy, which would no longer be zero-point... My guess is that all this virtual agitation down there is like a thermal bath and nothing useful (in terms of net work) can come out of it (second principle...) but please someone qualified help. If no useful work can be taped, then no cheap momentum exchange can be taped. The only help of virtual particles is when they come real but that needs same amount of energy/mass you would have to throw backward anyway to get momentum forward in classical reaction propulsion.

I'd like to see some qualified explanations with Feynman diagrams showing how it's impossible to push on virtual particles (unless they are made real at equivalent energy/mass cost).

Quote
It's like saying I'm going to work on extracting energy from the number 3.
You could still extract energy from the work of trying, couldn't you ?
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/17/2014 03:22 am
Says me, yes.
Think about it carefully.
When you have, get back to me.
 :)
The CMB is a certain reference frame (just like another reference frame), but why the crap should you be able to push against it or whatever you're talking about? There is no "ether."

frobnfiahdfh:
The virtual particles work the same in every reference frame. And you COULD "push" on them, if you wanted to expend the necessary energy to make them real particles, but that'd be no more efficient than a photon drive.
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 08/17/2014 09:00 am
Conceptually, it's the same as a book lying on a desk. Desk is exerting a force on the book to counteract gravity but no energy is expended. Energy is force times distance. If a force is exerted on an object but the object doesn't move, no energy need be expended.

Thanks for responding!

How can a force be exerted without expending energy? (serious question). If I hold my fat aunt above my head and she doesn't move, I'm still using energy to exert a force to counter gravity.  ...
...
A solid "passive" object like a chair can hold a force on an object without expending any energy but it cant follow displacement in the direction of force, if aunty is an inch above chair then chair is no longer exerting force on aunty
If you pardon me the explanation of "energy equal force multiplied by distance and there is no distance involved", in my opinion of a layman is not enough to answer to "how a force can be exerted without expending energy". Actually it seems to me more a tautology than an explanation.
- It assumes an empty universe where two elements are considered in a static way. Using the concept of force is meaningless in this situation as they do not move, and by definition no energy is involved so IMO there is no explanation given. The key answer lies in energy budget in several states, including potential energy in its magnetic and gravitation aspects. Work is one form of energy, but there are many other forms, ultimately energy is a scalar, a quantity without direction attached contrary to a force which as a vector has a direction, and it is linked to the notion of mass. The energy concept is usefull to describe situations like the one proposed by sghill, as because by definition it is conserved from one state to the next, it easy to trace how it is transfered from one element to the other.
- If on earth we have a book at rest on a desk, it has more energy than the same book on the floor i.e. if it falls its energy could be transfered to another device. The desk do not fall because the manufacturer did put energy in it, and if you go as far as that, by assembling atoms, atoms can store energy at different places. When the book is put upon the desk, the desk and the book atoms store the gravitational potential energy of the book. If you remove the desk, the book last potential energy gain will be released and the book will fall to the next lower energy level (on the ground).
- It's the same for the two magnets of sghill, one is above the other, so this one has more potential energy, where does it comes? As the first magnet was put above the other, it gained in potential energy from the hand of the person who did it.
It can only goes down by sghill design and the other magnet pushes back on it, so where is the potential energy stored? It is in the atoms magnetic field. This is not free energy because energy had been initially used to magnetized those magnets, and the magnets do not permanently loose or gain energy when they are close to each other, because the previous energy budget will be restored as they will be pulled apart.

Indeed I am not a scientist, so I may be entirely wrong.
Title: Re: EM Drive Developments
Post by: frobnicat on 08/17/2014 09:27 am
Says me, yes.
Think about it carefully.
When you have, get back to me.
 :)
The CMB is a certain reference frame (just like another reference frame), but why the crap should you be able to push against it or whatever you're talking about? There is no "ether."

CMB photons do carry momentum so it might be possible to either sail relative to them or push on them but it's so weak I guess it's irrelevant for practical propulsion, better just make the photons onboard.
Quote
Energy density of CMB is ~1eV/cm-3, comparable to that of starlight in the Milky Way.
http://www.astronomy.ohio-state.edu/~dhw/A873/notes4.pdf (http://www.astronomy.ohio-state.edu/~dhw/A873/notes4.pdf)
Also those photons don't make it past an experiment chamber walls.

Quote
frobnfiahdfh:
The virtual particles work the same in every reference frame. And you COULD "push" on them, if you wanted to expend the necessary energy to make them real particles, but that'd be no more efficient than a photon drive.

Completely agree, unless whole contemporary physics turned on its head. Precisely what I meant was "work the same in every inertial reference frame".
frobnfiahdfh ?
Title: Re: EM Drive Developments
Post by: frobnicat on 08/17/2014 10:10 am
JPLeRouzic :
I can't find simple ideas to explain why energy = force x distance, all other ways to define energy relative to force would fail empirically so we could only relate that to convincing experiments and sensible definitions, or we could be deriving this "rule" from more basic principles (microscopically there is no "force", only momentum exchanges between bosons and fermions) that themselves would have to be admitted or understood from less mundane experiments...

My example of a passive object with a supporting force that don't "follow displacement" wanted to avoid the potential energy complexities involved with springs and possible oscillations around an equilibrium, maintaining the macroscopic equilibrium point by itself needing no net energy spending while quite a lot of energy can be buzzing around. Microscopic thermal agitation is a perpetual motion after all, the bottom of energy, where useful energy is "lost" as heat. Apart from the strange musings about "2 elements considered a static way in empty universe" I don't understand, the rest of what you say makes perfect sense and seems correct to me.

But how does this "force with no net spent energy" point relates to the topic ? A thruster has to exert a force through displacement (in any inertial frame since you also want to accelerate) so the distance term can't be 0 and spent energy can't be 0 either.

Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/17/2014 11:28 am
The CMB frame of reference is a physical entity.

No.

The CMB is a physical entity.  There is a reference frame associated with it.  That doesn't make the reference frame a physical entity.

There is also a reference frame associated with the Earth.  It's just the frame in which the Earth is at rest.  That doesn't make the reference frame a physical entity you can transfer energy to or from.  You can transfer energy to and from the Earth.  You cannot transfer energy to and from the Earth's reference frame.

Again, it's like confusing the number 3 with a physical object.  It's like saying I'm going to construct three spaceships that have a shared drive that transfers momentum to the number 3 and thus produces thrust.  The fact that the number three is associated with something physical (three spaceships) doesn't make the number three a physical object, even though there are physically three spaceships.

You're really not helping your case for the plausibility of the EmDrive by displaying a profound misunderstanding of the most basic concepts of high school physics.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/17/2014 11:43 am
If you pardon me the explanation of "energy equal force multiplied by distance and there is no distance involved", in my opinion of a layman is not enough to answer to "how a force can be exerted without expending energy". Actually it seems to me more a tautology than an explanation.

It's not a tautology or an explanation.  It's a definition.  It's the definition of the term "work" in physics.

It turns out that if we define work that way, it's a useful concept for predicting what will happen in the physical world.  It turns out that if you look at the work done combined with some other quantities, the sum never changes.  This is called conservation of energy.  Work is just one component of energy, really.

It seems strange that a force that isn't moving an object expends no energy only because it conflicts with many of our every-day experiences.  For example, if we push hard against a wall, we apply force to it, and there is no movement, but it tires us out to keep pushing.  So we think that we have to use up energy to keep a force applied even when there is no movement.

But we're fooled in this case, because work is being done, we're just not seeing it.  That energy is turning into heat, which is just movement of molecules.

So, when we try to apply a force directly with our muscles, we have to expend energy even if there is no obvious movement because we are causing lots of molecules to move around more quickly.

On the other hand, a magnet is a good example of an everyday object that can keep applying a force with no energy expended.  Put a magnet on your refrigerator and it will stay there for years.  It will keep applying a force to stick the magnet to the refrigerator, but no energy will be expended.

The magnet is capable of applying a force continuously without expending energy.  The magnet doesn't leak energy by causing something to heat up.  Your muscles are not capable of that.
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 08/17/2014 01:39 pm
@Frobnicat: First I apologize, English is not my native language. Second: I understand your concern about this topic and how an explanation based on energy conservation could have been misinterpreted as validating the propellantless thruster. The difficulty indeed is that energy is poured in this device and something must happen. However given the very low level of thrust, I find it perfectly possible that this energy is dissipated as heat and therefore, given the assymetry of the device, it warms air more on one side than the other, hence the net thrust.

On contrary it seems to me, that it is impossible to use the conservation of energy as an explanation of the EM drive (or other propellantless thruster) as it would in this case produce much more thrust that people claim it does. A simple RC plane or a RC car use less power for a similar mass and gives visible results, no need for ad hoc extra sensible torsion pendulum  :).
 
@ChrisWilson68: I think that you may have not read my whole post and stop after the first phrase.

My point isn't that a magnet produces some energy, it does not indeed. It is that the given explanation is circular, and I provided another explanation based on energy conservation.
By the way I am sure a modern definition of energy is not "energy is force by distance". What is important and much more modern is that energy is conserved. It was on this premise that I gave my explanation.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/17/2014 02:05 pm
The CMB frame of reference is a physical entity.
I'll make no bones about it.
My assertion is wrong.
Thanks guys.
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/17/2014 02:53 pm
Props for that, Island!
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/18/2014 01:41 pm
Says me, yes.
Think about it carefully.
When you have, get back to me.

Just read the oracle.  Sheesh.

http://en.wikipedia.org/wiki/Cosmic_microwave_background

Still, a frame of reference is a different sort of physical entity than say, an apple, subject to gravity.

I keep thinking that there is an ether.  I'm just a nineteenth century guy, I guess.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/18/2014 01:41 pm

How can magnets attract or repel each other indefinitely without expending energy?

Nobody completely understands magnetism either.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/18/2014 01:42 pm

No movement - no impulse. I mean, it is IMHO comparable to a book standing on a table. No-one would imply that the book were to 'violate' impulse conservation in any way ;) . So, what's going on here?

The area that Woodward is looking into regards having a better understanding of inertia.  Sciama holds a theory, based on Mach's work, that the entire universe immediately pushes back on the book, so that, in principle, one can discard the table entirely.  Basically, Woodward is attempting to convert electricity into momentum.  Electricity goes into his device, and then the device moves forward, if not otherwise bound by gravity.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/18/2014 01:42 pm
I think one has to be careful when calling found physical principles 'laws'. They are not laws in the absolute sense, as in given by 'God', or being the final answer. The only thing we can say about the principles that we found and verified by peer-reviewed experiments up to any given point in time is: To the best of our current knowledge, this is what happens. A very important point to make.

Just want to add the observations of C.S. Peirce, who has suggested quite some time ago, that the "laws" of physics might be "habits", and that they change over time.

The gravitational constant, it turns out, is not exactly constant, but appears to vary.

I also want to point out that inanimate interpretations of the beginnings of the universe and evolution are as faith based as any other interpretations.

[Edit: Inadvertently forgot to include the important word "beginnings" of the universe, as was pointed out below.]
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/18/2014 01:42 pm
"But physics can't be bypassed," you say - well who can claim omniscient knowledge of physics? There may be small exploit opportunities which can be exposed here and there.

Then find them and exploit them.  At least Mr. Wooward is making an attempt.  By my reading, few physicists claim omniscient knowledge of physics.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/18/2014 01:42 pm
i have seen people here pan fusion propulsion.; a likely possible near term advancement.

Fixed that for ya.

It is more likely that fission drive (Boom-boom Orion) is near term than fusion drive.  My objection continues to be the careless, unsubstantiated  use of the word "likely".

As to VaSIMIR, I'm a mite confused by all of your negatives:  It isn't that unlikely?  This drive is real, but it has not been scaled to the extent necessary to propel, say, MCT.  It is more "likely" to be a "near term advancement" than boom-boom Orion, the way I see it.
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/18/2014 01:54 pm

How can magnets attract or repel each other indefinitely without expending energy?

Nobody completely understands magnetism either.
(warning, language) http://m.youtube.com/watch?v=OvmvxAcT_Yc


And for the record, we understand magnetism quite well, thank you very much. A direct consequence of classical electrostatics and special relativity.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/18/2014 02:40 pm
i have seen people here pan fusion propulsion.; a likely possible near term advancement.

Fixed that for ya.

It is more likely that fission drive (Boom-boom Orion) is near term than fusion drive.  My objection continues to be the careless, unsubstantiated  use of the word "likely".

As to VASIMR, I'm a mite confused by all of your negatives:  It isn't that unlikely?  This drive is real, but it has not been scaled to the extent necessary to propel, say, MCT.  It is more "likely" to be a "near term advancement" than boom-boom Orion, the way I see it.
let me fix it back then: Some fusion propulsion is likely near term both because there are a couple of fusion projects that lend themselves to propulsion and because politically you will see fusion in space well before Dr Chang Diaz gets enough to put more than a satellite booster sized test article on ISS if he ever gets the chance to do even that with slipping schedules, carriers and so forth.

EDIT I need to fix it again XD.

There is one fusion project blatantly stating they are working with NASA on a fusion engine. There are other fusion projects swinging at beating ITER. one of those has mentioned using it as a power source for electric propulsion. that onion layered reactor thing with the fancy spark plug (DPF.) it's not direct fusion drive but the power source for electrical or plasma propulsion. maybe even powering VASIMR.
Title: Re: EM Drive Developments
Post by: Star One on 08/18/2014 03:08 pm
I think one has to be careful when calling found physical principles 'laws'. They are not laws in the absolute sense, as in given by 'God', or being the final answer. The only thing we can say about the principles that we found and verified by peer-reviewed experiments up to any given point in time is: To the best of our current knowledge, this is what happens. A very important point to make.

Just want to add the observations of C.S. Peirce, who has suggested quite some time ago, that the "laws" of physics might be "habits", and that they change over time.

The gravitational constant, it turns out, is not exactly constant, but appears to vary.

I also want to point out that inanimate interpretations of the universe and evolution are as faith based as any other interpretations.

To expand on your comment above I see there are some theorists suggesting that gravity at the massive scale, for want of a better term may not be the same as gravity at a local level and that the search for dark matter & energy could be futile. The argument goes that these latter two were invented purely as a kludge in the theory to fit the observations.

Do we even if subconsciously seem somehow to risk slipping back into almost Ptolemaic terms sometimes when discussing the laws of physics?
Title: Re: EM Drive Developments
Post by: Mulletron on 08/18/2014 04:01 pm
A frame of reference is relative. Just a comparison to another system. It is not a physical thing. It is a physical system, be it thermodynamic, relativistic, quantum, non/inertial, whatever. A lot of folks just assume that when frames of reference are talked about, that it must be inertial. Moreover, a frame of reference is not a container of things, just a way of comparing what is happening here verses there. An interaction with another frame of reference is an interaction with the "things" in that other frame of reference. Of course you can't push against a number 3. Numbers are more epistemological than real. Lets not be obtuse here. That did bring back memories of comparisons I read about how information/energy/matter are equivalent though, and how an AND logic gate will convert that lost bit of information to heat energy, but I digress. I'm not writing about the philosophy of science.

So back to the thruster and how frames of reference are key.

I previously talked about two other qv interactions with matter, the Lamb Shift and Casimir. Here's another possible one. So I read into the controversial Unruh effect that says roughly, in an accelerating frame of reference, virtual particles observed outside your frame of reference (be it stationary or slower) may appear to become real particles. The vacuum of the stationary frame of reference as seen from the accelerating observer appears to contain some real particles. Now in your local yet accelerating frame of reference, virtual particles are there happening around you but aren't observed as "real." Meaning they don't stick around long enough to become real. Meaning you can't do jack with them. But there's hope. Thankfully because acceleration is relative, an observer outside of your frame of reference will see your virtual particles become real. That doesn't help us either, but the methodology is key. As you know, frames of reference are relative.

So I flipped it. How about this: We live in an accelerating universe. Our universe is accelerating at rates which we cannot ever hope to achieve. Furthermore, the rate of expansion is a curve, meaning galaxies further away are flying apart faster than the ones flying apart closer to us. Neat. So from the point of view of the universe, which is the accelerating frame of reference, our emdrive is accelerating slowly, compared to say the CMB frame of reference.

So lets imagine ourselves on a spaceship in Earth orbit and you are equipped with our brand new emdrive technology. From your frame of reference you are barely moving compared to the accelerating speed of universal expansion happening around you. So imagine yourself inside your space ship and you're looking intently at your prototype emdrive looking for real particles to appear out of the qv fluctuations, you don't see them. Now imagine the universe is the observer. The universe observing your emdrive would see some virtual particles from the qv becoming real. This only works if the universe is expanding. So with this mechanism, you get some arbitrary flux of real particles from the qv frame of reference (I'm assuming the qv and its randomly produced particle pairs are not inertially related to our inertial frame of reference) popping into your local frame of reference (as observed from the point of view of the universe). So I'm picturing the pair production happening randomly, becoming real, and immediately flying away at a rate matching the speed and direction of the expansion of the universe minus the influence of gravity, isotropically. My head hurts.

This next part I'm iffy on too: So since the universe has no center from where to measure expansion or acceleration against (correct assumption?), does it make any difference what the acceleration of the space ship is? Would accelerating the ship result in a gain in particle pair longevity? I don't think it becomes an issue until you get near relativistic speeds. Is it possible to accelerate, or are we already accelerating at a rate faster than the LOCAL expansion rate of the universe as seen within the bounds of the emdrive? Is gravity keeping the expansion of the universe in check at small scales? Would accelerating the ship increase the real particle longevity flux? I don't know. Maybe doesn't help anyway. All of this depends on whether the Unruh effect is real or not.

I personally don't have much confidence that this is what is happening, I'm just brainstorming this approach. I think the logic above would have us all awash in real particles all the time. Maybe that's where matter comes from, lol. Maybe that's what boggs us down when approaching the speed of light. The thoughts above concerning the Unruh Effect are just concerned with creating real particles to interact with and I believe the effect is probably small solely because it is controversial. I think it could be small part of what's happening. I read somewhere that a very large charge field within a highly polarized dielectric medium stimulates pair production, which could in turn become real. I think that most of the effect stems from directing the poynting vector of a very strong rf field down the axis of desired acceleration through a dielectric is causing a transfer of momentum in a way I don't fully understand. I disagree with the shape of the bell/pill box on the two drives tested as I think they are unnecessary. I think they should take design cues from coaxial cables, only terminating the end in a way to scavenge the rf for reuse back into the top of the thruster. I think a resonant standing wave doesn't do much for the thruster and that max rf energy flow is key. I'm picturing a bundle of cylinders arranged into a honeycomb shape, with rf distributed into the top and the other ends capped off with a door knob type of rf probe as a pick up. The energy density of the cmb peaks at around 160ghz. I'm not sure if a frequency matching it would be helpful or not. It would make for a very small wavelength, and all the design implications that go along with it.
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/18/2014 05:24 pm
i didn't think Unruh was all that controversial anymore? i think I have seen it outside the usual speculative propulsion related stuff. i thought it was scientifically established?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/18/2014 05:46 pm
Just wanna add that we understand quantum mechanics "quite well" too.  Nobody claims complete knowledge of QM or magnetism.
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/18/2014 06:02 pm
Just wanna add that we understand quantum mechanics "quite well" too.  Nobocy claims complete knowledge of QM or magnetism.
No, we understand exactly what's going on in magnetism. We also under QM fully, too, it's just very counter-intuitive. Just because you don't understand it and just because it takes a lot of effort to understand it doesn't mean it isn't understood.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 08/18/2014 08:12 pm
Just wanna add that we understand quantum mechanics "quite well" too.  Nobocy claims complete knowledge of QM or magnetism.
No, we understand exactly what's going on in magnetism. We also under QM fully, too, it's just very counter-intuitive. Just because you don't understand it and just because it takes a lot of effort to understand it doesn't mean it isn't understood.
Nit picking.
We *don't* understand QM fully. It is obviously incomplete.
Gravity etc.
Title: Re: EM Drive Developments
Post by: frobnicat on 08/18/2014 11:45 pm
What we do know from innumerable experiments is that in a broad range of contexts QM is phenomenally accurate. This broad range includes all mundane particles, real or virtual, with energies up to a few 10s of Gev in any locally linearisable space-time. The fact that GR is a separate formalism doesn't prevent both theories taken together to be effective and precisely verified at predicting measurable outcomes in all but the most distant or artificially unattainable circumstances. The remaining phenomenological mysteries below extreme energies and/or gravitational curvatures might come from neutrinos or weakly interacting particles like dark matter, but they are precisely very weakly coupled to EM fields, otherwise their absence or uncertainties in theories would seriously limit the predicting power of SM which appear is not the case even with higher and higher precision measurements. There's still room for surprises, proton radius appear different when orbited by muon rather than electron. But overall the formalism looks solid and can accommodate extensions, as was and still is classical mechanics in its own range of validity. It's still insufficient by itself to mechanically tell all that can/will be done/discovered with arrangements of lot of particles (ie condensed matter properties...) at "emergent" scales but it certainly has some credit to tell that an arrangement of particles can't globally break a law that is experimentally shown to be respected at every single interaction point. There is a reason why some laws are called fundamental, and it's not a matter of scientists acting as prosecutors to enforce them, it's deeply embedded regularities of reality as it is observed.

So while we don't understand all QM at the frontiers of its validity and beyond, we do know quite well experimentally where the frontiers are, and while the interpretation of QM (the why or the what) is still hotly debated, the empirical predictive power speaks for itself and naturally entails much scepticism from mainstream physicists when a device consisting only of low density microwave photons bouncing around in ordinary matter claims either momentum conservation breaking or transferring momentum to vacuum (which in the later case is taping energy from the vacuum since vacuum is so far so very well experimentally confirmed to be inertial frame invariant).

Clearly if such thrust effects are worth investigating, then they are worth more than a week of a small team (speaking of the latest NASA experiment), and while I would say that they did a terrific experimental job given such a short time and limited resources, indulging themselves in "what if" scenarios of missions at the end of the paper does not serve them in terms of credibility : you can't write such a result and pretend to ignore how it is flying in the face of established physics before it flies to Mars, this is not serious and maintains the idea that such research is fringe science and not worth considerations. I wish despite this clumsiness they are granted more time and resources to either get a decent 0 net thrust measurement result, or a Nobel prize.
Title: Re: EM Drive Developments
Post by: Raj2014 on 08/19/2014 12:31 am
Has there been any new news on the EM/Cannae drive?
Title: Re: EM Drive Developments
Post by: Robotbeat on 08/19/2014 01:01 am
Just wanna add that we understand quantum mechanics "quite well" too.  Nobocy claims complete knowledge of QM or magnetism.
No, we understand exactly what's going on in magnetism. We also under QM fully, too, it's just very counter-intuitive. Just because you don't understand it and just because it takes a lot of effort to understand it doesn't mean it isn't understood.
Nit picking.
We *don't* understand QM fully. It is obviously incomplete.
Gravity etc.
We don't have a theory of quantum gravity, but that'd be an extension of QM. QM itself we understand quite well and is complete. It doesn't have to be the theory of everything to be complete.

Anyway, I'm quitting this thread. In the words of Antares, I'm through arguing with amateurs. People want to skip learning regular physics that we already have a 100% understanding of and instead argue about fringe theories and physics beyond the standard model. It's ridiculous. You can't prove physics is wrong and incomplete until you actually understand physics! It's not like it's secret knowledge or something. The only reason people skip it is because they're lazy.

In a parting shot, I've seen this proposed as the Fourth Law of Thermodynamics:
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/19/2014 01:38 am
 ;D  shamelessly stolen and stored for future use elsewhere. :)
Title: Re: EM Drive Developments
Post by: frobnicat on 08/19/2014 02:07 am
A frame of reference is relative. Just a comparison to another system. It is not a physical thing. It is a physical system, be it thermodynamic, relativistic, quantum, non/inertial, whatever. A lot of folks just assume that when frames of reference are talked about, that it must be inertial.

Not necessarily inertial, but beware that inertial or not can be told locally without any outside reference, a simple accelerometer would suffice. So inertial frames are special. In an absolute sense.

Quote
.../... Thankfully because acceleration is relative, an observer outside of your frame of reference will see your virtual particles become real. That doesn't help us either, but the methodology is key. As you know, frames of reference are relative.

Inertial frames are relative, as proper time/distance transforms can translate observables of one frame into observables in the other. Well, I guess taking acceleration into account that is also possible for accelerated frames (introducing Coriolis "forces" for instance).

Quote
So I flipped it. How about this: We live in an accelerating universe. Our universe is accelerating at rates which we cannot ever hope to achieve. Furthermore, the rate of expansion is a curve, meaning galaxies further away are flying apart faster than the ones flying apart closer to us. Neat. So from the point of view of the universe, which is the accelerating frame of reference, our emdrive is accelerating slowly, compared to say the CMB frame of reference.

It's not clear what time derivative you are talking about : the rate of expansion (Hubble "constant") that goes as ~2.3e-12(m/s)/m (hey, it has dimension of a frequency !), or the change of this rate, which right now seems to be decelerating ( for a given distance you will see slower receding objects crossing this distance in the near future ) in spite of the mysterious acceleration of expansion (expansion not slowing as fast as it should, but still slowing from usual mass content gravity) ?
More confusing : the universe isn't locally accelerating, makes no sense, its local content has a local average speed that can be used as a local inertial frame of reference, but it is not accelerating in any absolute sense, there is nowhere special toward where it could accelerate ! The CMB is part of the content, take or give a few 100s km/s it's the same local inertial frame as the stars and gas averaged on a decently sized local patch, it goes with the flow, and this flow is 0 relative to receding neighbouring patches all around. Local universe is not accelerating if seen at coarse graining bigger than anisotropies. What particular direction of the sky the CMB is supposed to be accelerating (I'm not speaking of our galaxy relative velocity with CMB) ? And even if it were, it would just be free falling with us (say, with the local cluster) at the same acceleration toward a big lump in the neighborhood. Anyway it's not accelerating relative to us and relativity makes no difference between free-falling and inertial velocity in nothingness.

Quote
So lets imagine ourselves on a spaceship in Earth orbit and you are equipped with our brand new emdrive technology. From your frame of reference you are barely moving compared to the accelerating speed of universal expansion happening around you.

I'm barely moving relative to the speed of a specific cluster 1Bly away but in the walls of my ship, or even when considering the whole galaxy, the Universe could be static rather than expending wouldn't change a thing for me, how could a phenomenon occurring over cosmological times/distances could make any difference locally ?

Quote
So imagine yourself inside your space ship and you're looking intently at your prototype emdrive looking for real particles to appear out of the qv fluctuations, you don't see them. Now imagine the universe is the observer. The universe observing your emdrive would see some virtual particles from the qv becoming real. This only works if the universe is expanding.

What part of the universe is observing, my local patch average ? A co-orbiting inertial frame ? Earth ? Sun ? Galaxy ? None of those scales make any care of the fact that universe is expending, or that the rate of expansion varies a bit in a long while (sorry, can't find precise numbers here, but next to impossible to measure inside a lab, so making no difference for a ship).
 
Quote
So with this mechanism, you get some arbitrary flux of real particles from the qv frame of reference (I'm assuming the qv and its randomly produced particle pairs are not inertially related to our inertial frame of reference) popping into your local frame of reference (as observed from the point of view of the universe). So I'm picturing the pair production happening randomly, becoming real, and immediately flying away at a rate matching the speed and direction of the expansion of the universe minus the influence of gravity, isotropically. My head hurts.

I believe so. Trying hard and seriously to get your point but "matching the speed and direction" in one hand and "isotropically" the other seems like an oxymoron. Looks like your are longing for the inflation epoch when
a field of accelerated expansion (second order) was so strong it could everywhere rip apart virtual particles pairs to make them real. Would be compatible with the isotropy. Thing is, when such a field is so strong, reality tends to be not very stable and quickly evolves. We are in a stable epoch, stability of time prevents energy conservation breaking (as would be the case when virtual particles become real, note that the accelerating field is actually decaying, it loses some punch in the process). And stability of space (isotropy) prevents momentum conservation breaking. As per Noether's theorem.

Quote
.../... Is gravity keeping the expansion of the universe in check at small scales? .../...

Yes. Expansion observed now is just an inertial collective movement from initial expanding conditions. Gravitationally bound objects are not obliged to abide to Hubble law. The dark energy or lambda parameter on the other hand is supposed to act on metrics by "fabricating" more space between objects (while a relative inertial receding velocity don't really make more space per se), so if its pressure increases it could conceivably first alter then rip apart gravitationally bound objects. Local effects (at galaxy scale) are not expected to occur soon.
 
Quote
I think the logic above would have us all awash in real particles all the time. Maybe that's where matter comes from, lol.

Some think this is exactly what happened but not all the time, just at the end of the inflation when the inflaton field decayed into usual particles, and thus stopping inflation, see, this process can't last long. It's not stable.

Can't give other opinion for the rest as the Unruh effect is above my head, also I would tend to agree that resonance seems pointless (except maybe for efficiency of the coupling to the RF generator as the system must be analysed as a whole).


Title: Re: EM Drive Developments
Post by: su27k on 08/19/2014 05:24 am
Jeff Foust has half an article on this in Space Review: http://www.thespacereview.com/article/2580/1, including a brief interview with White after his talk in Mars Society conference
Title: Re: EM Drive Developments
Post by: su27k on 08/19/2014 05:31 am
We also under QM fully, too

I think Feynman may disagree:

Quote
I think I can safely say that nobody understands quantum mechanics.
Title: Re: EM Drive Developments
Post by: Star One on 08/19/2014 06:25 am
Has there been any new news on the EM/Cannae drive?
http://xkcd.com/1404/

Blimey people don't half like quoting that cartoon that's several times in this thread alone.:)

Anyway from what was in the report I don't think we'll be hearing any more too either much later this year but more likely next.

Quote from: su27k
Jeff Foust has half an article on this in Space Review: http://www.thespacereview.com/article/2580/1, including a brief interview with White after his talk in Mars Society conference

Thanks for that puts it in a better context. Funnily the reporting of this seemed more accurate at the start but as it became reporting of reporting it seemed to get more outlandish.
Title: Re: EM Drive Developments
Post by: Mulletron on 08/19/2014 03:03 pm
Quote

It's not clear what time derivative you are talking about : the rate of expansion (Hubble "constant") that goes as ~2.3e-12(m/s)/m (hey, it has dimension of a frequency !), or the change of this rate, which right now seems to be decelerating ( for a given distance you will see slower receding objects crossing this distance in the near future ) in spite of the mysterious acceleration of expansion (expansion not slowing as fast as it should, but still slowing from usual mass content gravity) ?
More confusing : the universe isn't locally accelerating, makes no sense, its local content has a local average speed that can be used as a local inertial frame of reference, but it is not accelerating in any absolute sense, there is nowhere special toward where it could accelerate ! The CMB is part of the content, take or give a few 100s km/s it's the same local inertial frame as the stars and gas averaged on a decently sized local patch, it goes with the flow, and this flow is 0 relative to receding neighbouring patches all around. Local universe is not accelerating if seen at coarse graining bigger than anisotropies. What particular direction of the sky the CMB is supposed to be accelerating (I'm not speaking of our galaxy relative velocity with CMB) ? And even if it were, it would just be free falling with us (say, with the local cluster) at the same acceleration toward a big lump in the neighborhood. Anyway it's not accelerating relative to us and relativity makes no difference between free-falling and inertial velocity in nothingness.


Hubble's Constant: H0 = 67.15 ± 1.2 (km/s)/Mpc. For every million parsecs of distance from the observer, the rate of expansion increases by about 67 kilometers per second.

The further away from the observer, you'll observe the velocity of galaxies increasing.
Title: Re: EM Drive Developments
Post by: frobnicat on 08/19/2014 04:20 pm

Hubble's Constant: H0 = 67.15 ± 1.2 (km/s)/Mpc. For every million parsecs of distance from the observer, the rate of expansion increases by about 67 kilometers per second.

The further away from the observer, you'll observe the velocity of galaxies increasing.

Yes, for every added meter distance you will see an added receding speed of about 2 picometers/second, it would be around 1m/s between Earth and Jupiter, but this is not an intrinsic law of the vacuum or space-time, just an average of inertial expansion from initial conditions and gravitationally bound "objects" like a galaxy don't see this effect within. Dark energy or accelerated expansion on the other hand appears to be intrinsic to space-time, but even if majority of energy content, its effect is very very weak on local scales, now and for the foreseeable future, so weak it is only slowing the slowing of expansion rate due to gravity, not yet accelerating it. Its only strength is it don't dilute like ordinary mass-energy content so it might win at the end. Until then its effect couldn't be detected locally inside a lab, even less used for any purpose.

The further away from the observer, you'll observe the receding velocity of galaxies increasing. Alright. Then taking the mean velocity of the galaxies all around at a given distance, you would see a residual relative velocity due to the velocity of our galaxy relative to average local content (say, CMB dipole, A few 100s km/s) but there is really no reason this velocity in the "neighbourhood frame as a whole" would accelerate. The neighbourhood is expanding but we (as any other content anywhere) are always like at the centre of this expansion, with no acceleration in any particular direction. And even if it did accelerate in a particular direction, what gives ? This would be like a free fall. A collection of free falling objects (not around a very compact object) don't make a distinction with just floating in nothingness.

And what is the relation of those far away galaxies and a ship orbiting Earth ? If we could build tethers out to 100s Mpc to grab onto receding neighbouring galaxies around, then we would surely have a good source of energy, and if dark energy holds that could even be a physically sound unlimited "free energy" source, albeit a little cumbersome. Short of that, what is our physical relation to those receding galaxies beyond a bunch of redshifted photons ?
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/19/2014 08:26 pm
according to Wheeler and Feynman and Ernst Mach we are tethered to everything all the way to the ends of the universe :) 

Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/20/2014 02:42 pm
Just wanna add that we understand quantum mechanics "quite well" too.  Nobody claims complete knowledge of QM or magnetism.
No, we understand exactly what's going on in magnetism. We also under QM fully, too, it's just very counter-intuitive. Just because you don't understand it and just because it takes a lot of effort to understand it doesn't mean it isn't understood.

You confuse general or even detailed understanding with complete understanding.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/20/2014 02:59 pm

My objection continues to be the careless, unsubstantiated  use of the word "likely".

...Some fusion propulsion is likely near term both because there are a couple of fusion projects that lend themselves to propulsion ...

EDIT I need to fix it again XD.

There is one fusion project blatantly stating they are working with NASA on a fusion engine. ...

Unfortunately, you continue to misuse the term "likely".  Because "there are a couple of fusion projects that lend themselves to propulsion", and even "one fusion project blatantly stating they are working with NASA on a fusion engine" does not prove anything at all about the liklihood of these efforts succeeding in their experimental work.

I will make this prediction:  It is likely that there will be more fusion propulsion research projects in the future, and some of these might get substantial funding.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/20/2014 03:02 pm
What we do know from innumerable experiments is that in a broad range of contexts QM is phenomenally accurate. ...

This is a true statement. It does not go beyond what has been proven, nor does it suggest implausible warp drives.

Quote
So while we don't understand all QM at the frontiers of its validity and beyond, we do know quite well experimentally where the frontiers are...

Beyond those frontiers be dragons.

Quote
...indulging themselves in "what if" scenarios of missions at the end of the paper does not serve them in terms of credibility...

This is always done as a precursor to the never ending request for additional funding.  The request is not new, innovative, different, illegal, nor at all non-predictable.

I like your post.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 08/21/2014 05:53 am
I also want to point out that inanimate interpretations of the universe and evolution are as faith based as any other interpretations.

You obviously don't understand the difference between "faith based" and "evidence based".
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/21/2014 01:18 pm
I also want to point out that inanimate interpretations of the beginnings of the universe and evolution are as faith based as any other interpretations.

[Edit: Inadvertently forgot to include the important word "beginnings" of the universe, as was pointed out below.]

You obviously don't understand the difference between "faith based" and "evidence based".

Thanks for pointing out my inadvertent grammatical sloppiness, accompanied with the the bonus personal aspersion.

CW brought up a larger point, lost to Chris Wilson by my grammatical mistake:

I think one has to be careful when calling found physical principles 'laws'. They are not laws in the absolute sense, as in given by 'God', or being the final answer. The only thing we can say about the principles that we found and verified by peer-reviewed experiments up to any given point in time is: To the best of our current knowledge, this is what happens. A very important point to make.

Quote from: jf
Just want to add the observations of C.S. Peirce, who has suggested quite some time ago, that the "laws" of physics might be "habits", and that they change over time.

The gravitational constant, it turns out, is not exactly constant, but appears to vary.

The physical principles discovered so far, fairly well understood by a small group of specialists, (not including Feynman) while accurately explaining some events, are not "laws" in some absolute sense.

As CW puts it, To the best of our current knowledge, this is what happens.  CW mentioned a common TLA, and I just riffed on that, pointing out that alternate faith based origination myths are not "absolute" either.

I'm guessing that the universe might very well be more Godelian than some might admit, but that's a personal guess of mine.

Every so often I take a goog on CS Pierce's idea that the universe's "laws" may only be "habits", but I haven't found any recent research on the idea.

There's also the either deliberate or poorly informed confusion between complete knowledge, and a sound working knowledge, mentioned above, again, in a n unnecessairly scathing personal tone.

In 1986, at least, it was not known about the relationship of QM and inertia.  From the abstract:

http://iopscience.iop.org/0264-9381/3/3/009

Quote
A new point of view towards the problem of the relationship between gravitational and quantum phenomena is proposed which is inspired by the fact that the distinction between quantum fluctuations and real statistical fluctuations in the state of a system seems not to be maintained in a variety of phenomena in which quantum and gravitational effects are both important. One solution to this dilemma is that quantum fluctuations are in fact real statistical fluctuations, due to some unknown, but universal, phenomena. At the same time quantum fluctuations have certain special properties which distinguish them from other types of fluctuation phenomena. The two most important of these are that the action of quantum fluctuations is non-dissipative for the special case of systems undergoing inertial motion in the absence of gravitational fields, and that the dispersion constant for quantum fluctuations for a particle is inversely proportional to the inertial mass of the particle. These properties are summarised in a set of principles which, it is proposed, govern the relationship between quantum phenomena, gravitation and inertia.

The author, Lee Smolin, coinvented "double special relativity". (soon to be a flavor at the Baskin-Robbins Institute)

Per the oracle:

http://en.wikipedia.org/wiki/Lee_Smolin#Experimental_tests_of_quantum_gravity

Quote
Smolin is among those theorists who have proposed that the effects of quantum gravity can be experimentally probed by searching for modifications in special relativity detected in observations of high energy astrophysical phenomena. These include very high energy cosmic rays and photons and neutrinos from gamma ray bursts. Among Smolin’s contributions are the coinvention of doubly special relativity (with João Magueijo, independently of work by Giovanni Amelino-Camelia) and of relative locality (with Amelino-Camelia, Laurent Freidel and Jerzy Kowalski-Glikman).

Thinking for a minute again about the notion of "complete" scientific understanding, Smolin is also interested in and has been working on, the foundations of QM.

Quote from: the oracle
Smolin has worked since the early 1980s on a series of proposals for hidden variables theories, which would be non-local deterministic theories which would give a precise description of individual quantum phenomena. In recent years, he has pioneered two new approaches to the interpretation of quantum mechanics suggested by his work on the reality of time, called the real ensemble formulation and the principle of precedence.

In fact, in 1992, he wrote a book about his idea of "cosmological natural selection", which sounds pretty interesting.  See the oracle for more info on that.

Susskind: "I'm not sure why Smolin's idea didn't attract much attention. I actually think it deserved far more than it got."

I feel his pain.  A prophet is never appreciated in his own time.

This wiki page is a great education, I think.  Know it alls, won't think so, I guess.

Quote
Since 2006, he has collaborated with the Brazilian philosopher and Harvard Law School professor Roberto Mangabeira Unger on the issues of the reality of time and the evolution of laws. ...

A book length exposition of Smolin's philosophical views appeared in April 2013...

Sounds like Smolin knows QM "quite well" but not "fully".  Sheesh.

I get tired of arguing with amateurs.
Title: Re: EM Drive Developments
Post by: Mulletron on 08/21/2014 02:30 pm
I'm seeing a lot about knowing qm quite well vs fully. This really is moot. It is a distraction from the subject at hand which is the emdrive or derivatives. It is the height of hubris to state you fully understand anything. If we fully understood qm or its offshoots, the subject would be closed, further study wouldn't be warranted and, we'd all be Doc Brown.
Title: Re: EM Drive Developments
Post by: SteveKelsey on 08/22/2014 06:50 am
I like the notion, also expounded by Smolin I beleive, that physics is good at describing what happens, but not good at explaining what happens. The great precision with which QM describes events can be mistaken for accuracy in explaining what is going on.

Agreed this is getting away from Emdrive.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/22/2014 01:34 pm
I'm seeing a lot about knowing qm quite well vs fully. This really is moot. It is a distraction from the subject at hand which is the emdrive or derivatives. It is the height of hubris to state you fully understand anything. If we fully understood qm or its offshoots, the subject would be closed, further study wouldn't be warranted and, we'd all be Doc Brown.

Absolutely.  I just get tired of reading the same assertions over and over.  EM drive doesn't work as they have explained the theory so far.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 08/22/2014 01:35 pm
I like the notion, also expounded by Smolin I beleive, that physics is good at describing what happens, but not good at explaining what happens. The great precision with which QM describes events can be mistaken for accuracy in explaining what is going on.

Agreed this is getting away from Emdrive.

That Smolin page is most excellent.  I had heard of him, but yesterday was the first time I read about his work.  I would enjoy meeting him, if anybody here cares to set up the meeting.
Title: Re: EM Drive Developments
Post by: aceshigh on 08/22/2014 06:46 pm
Hubble's Constant: H0 = 67.15 ± 1.2 (km/s)/Mpc. For every million parsecs of distance from the observer, the rate of expansion increases by about 67 kilometers per second.

The further away from the observer, you'll observe the velocity of galaxies increasing.

a parsec = 3.2 ly

observable universe 12-13 billion light years... let´s consider it 13... 13 billion / 3.2 = 4 billion parsecs.

4 billion / 1 million = 4000

4000 * 67 = 268 thousand kilometers per second.

So at the edge of the universe, it is expanding almost at light speed away from us, right?
Title: Re: EM Drive Developments
Post by: MP99 on 08/22/2014 11:04 pm


Hubble's Constant: H0 = 67.15 ± 1.2 (km/s)/Mpc. For every million parsecs of distance from the observer, the rate of expansion increases by about 67 kilometers per second.

The further away from the observer, you'll observe the velocity of galaxies increasing.

a parsec = 3.2 ly

observable universe 12-13 billion light years... let´s consider it 13... 13 billion / 3.2 = 4 billion parsecs.

4 billion / 1 million = 4000

4000 * 67 = 268 thousand kilometers per second.

So at the edge of the universe, it is expanding almost at light speed away from us, right?

Not "almost".

As we look at objects receding from us faster, they have a greater redshift. (This is an over simplification, but it's essentially correct.)

Once you reach the distance where Hubble expansion gives you recession at light speed, any light from there would undergo an infinite redshift, so it never reaches us. This is the definition of the edge of the "observable universe".

So, well spotted.

That edge is basically an event horizon, just like the boundary of a black hole.

BTW, the assumption is that the "observable" part of the universe may be a miniscule fraction of what was created from the big bang, in the same way that the universe outside a black hole is much bigger than the hole itself.

One big difference, though - an observer 10 billion light years away in our universe should also see a similarly-sized visible universe, but in a sphere centred on them. We share observability of lots of space, but they can see things that are beyond our horizon, and they can't see stuff that's distant from us in the opposite direction.

Every observer sees a different universe centred on them.

Cheers, Martin
Title: Re: EM Drive Developments
Post by: aero on 08/23/2014 02:37 am
Oh - So my kid is right. He is the center of the universe. Oh well, I guess we are all the center of our own little, and our own big universe.
Title: Re: EM Drive Developments
Post by: Mulletron on 08/24/2014 12:48 pm
Just found this gem. Wanted to share it:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf

Seriously cool stuff. I'm in awe.
Title: Re: EM Drive Developments
Post by: Mulletron on 08/24/2014 01:02 pm
Full paper regarding recent NASA test campaigns of emdrive and cannae:

http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf


Anyone know any ways to increase the rate of quantum fluctuations and produce a greater flux of particle/antiparticle pairs? I got an indication earlier that this happens within dielectrics to a degree. (think it was the NASA slide show) Would a really strong electric charge field work, like in a capacitor across a dielectric? Could a strong enough electric field cause these virtual particle pairs to be ripped apart before they annihilate? If so, are these energy levels realistic or very high energy stuff? I know that high energy photon interactions with atomic nuclei can cause pair production if the energy of the photons is twice the rest mass of the particle, like for electrons, it is .511 MeV I think it was. So you need high energy photons. Any way to lower the energy requirement? A lower energy requirement would allow us to use lower frequencies. That's the goal I'm shooting for here. Radio frequencies instead of Gamma. Thoughts anyone?

Title: Re: EM Drive Developments
Post by: Avron on 08/24/2014 01:11 pm
Thoughts anyone?

Not enough power,.. if 1Kw can make it vibrate.. 1 Mw should make it move
Title: Re: EM Drive Developments
Post by: Mulletron on 08/24/2014 01:26 pm
Well I can't see power being the major engineering problem here. I work with RF in my day job and power out isn't that big a deal, but higher frequencies, which equates to higher photon energies could be a problem. A waveguide for gamma rays, if you could contain them, would be very tiny. Focusing x-rays and gamma rays is a pain too.
Title: Re: EM Drive Developments
Post by: Avron on 08/24/2014 01:40 pm
Well I can't see power being the major engineering problem here. I work with RF in my day job and power out isn't that big a deal, but higher frequencies, which equates to higher photon energies could be a problem. A waveguide for gamma rays, if you could contain them, would be very tiny. Focusing x-rays and gamma rays is a pain too.

Question,, has anyone measured the counter force, if any to the Sagnac effect?
Title: Re: EM Drive Developments
Post by: Mulletron on 08/24/2014 01:52 pm
Well I can't see power being the major engineering problem here. I work with RF in my day job and power out isn't that big a deal, but higher frequencies, which equates to higher photon energies could be a problem. A waveguide for gamma rays, if you could contain them, would be very tiny. Focusing x-rays and gamma rays is a pain too.

Question,, has anyone measured the counter force, if any to the Sagnac effect?

I'm familiar with this concept from gyros. Basically you split a laser beam and make each travel around a half circle to a detector. If the circle rotates, one laser beam will travel a longer path and the other a shorter path, which is picked up at the detector. How does this apply here? What are you getting at?
Title: Re: EM Drive Developments
Post by: Stormbringer on 08/24/2014 02:47 pm
Well I can't see power being the major engineering problem here. I work with RF in my day job and power out isn't that big a deal, but higher frequencies, which equates to higher photon energies could be a problem. A waveguide for gamma rays, if you could contain them, would be very tiny. Focusing x-rays and gamma rays is a pain too.
if i understand correctly there has recently been a development in controlling gamma rays with meta materials or something like that. i vaguely recall something about meta-materials allowing lensing or refracting gamma rays and it having implications for smaller gamma ray telescopes and possibly other applications like lasers and so forth.
Title: Re: EM Drive Developments
Post by: Mulletron on 08/24/2014 02:56 pm
Another presentation by Dr. White:

http://www.astronautical.org/sites/default/files/vonbraun/2009/Von_Braun_Symposium_2009-10-21_7b_White.pdf

Title: Re: EM Drive Developments
Post by: Stormbringer on 08/25/2014 04:48 am
Full paper regarding recent NASA test campaigns of emdrive and cannae:

http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf


Anyone know any ways to increase the rate of quantum fluctuations and produce a greater flux of particle/antiparticle pairs? I got an indication earlier that this happens within dielectrics to a degree. (think it was the NASA slide show) Would a really strong electric charge field work, like in a capacitor across a dielectric? Could a strong enough electric field cause these virtual particle pairs to be ripped apart before they annihilate? If so, are these energy levels realistic or very high energy stuff? I know that high energy photon interactions with atomic nuclei can cause pair production if the energy of the photons is twice the rest mass of the particle, like for electrons, it is .511 MeV I think it was. So you need high energy photons. Any way to lower the energy requirement? A lower energy requirement would allow us to use lower frequencies. That's the goal I'm shooting for here. Radio frequencies instead of Gamma. Thoughts anyone?

well i remember a positron generator that used a laser to create a dynamical casimir mirror or other effect that produced and separated positrons (i guess they threw the electrons away or left them unused) so i have seen something like that. all the hooplah was over the fact that it would sit on half a desktop for a footprint. it was at one of the national labs.
Title: Re: EM Drive Developments
Post by: sghill on 09/02/2014 08:10 pm
OK,. I know we beat the heck out of this topic, but I had a thought over the weekend I wanted to float.

What if the EMDrives that Eagleworks tested were acting like a heat engine such as you'd find in a Crookes radiometer instead? 

If the microwaves imparted energy unevenly on the internal surface of the "thruster" and the test article, then it could generate the thrust as blackbody radiation warming air molecules just like in a Crookes radiometer that the torsion balance could have picked up.    http://en.wikipedia.org/wiki/Crookes_radiometer

They didn't test the things in a vacuum where this effect would not have occurred, which is why I thought it may be a possibility.
Title: Re: EM Drive Developments
Post by: Star One on 09/02/2014 09:10 pm
I thought it was tested in a vacuum chamber.
Title: Re: EM Drive Developments
Post by: QuantumG on 09/02/2014 09:13 pm
Radiometers do work in a vacuum, just not particularly well.
Title: Re: EM Drive Developments
Post by: MP99 on 09/02/2014 10:01 pm
I thought it was tested in a vacuum chamber.
Yup, bat at 1 atmosphere.

Capacitors couldn't take vac, IIRC.

Cheers, Martin
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 09/03/2014 07:13 am
NASA has its own list of capacitors that includes aluminum capacitors with solid conductive polymer as the electrolyte material that are compatible with the wide range of requirements for working in space conditions.

BTW your iPhone and most modern miniaturized electronic devices use capacitors with the same technology because no bulky wet capacitor would fit the form factor.

On a completely unrelated topic, unfortunately this kind of capacitor fuels wars in central Africa.
Title: Re: EM Drive Developments
Post by: MP99 on 09/03/2014 07:36 am
NASA has its own list of capacitors that includes aluminum capacitors with solid conductive polymer as the electrolyte material that are compatible with the wide range of requirements for working in space conditions.

BTW your iPhone and most modern miniaturized electronic devices use capacitors with the same technology because no bulky wet capacitor would fit the form factor.

On a completely unrelated topic, unfortunately this kind of capacitor fuels wars in central Africa.
Isn't this a far higher power level than iPhone?

Cheers, Martin
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 09/03/2014 08:22 am
=>It depends about what you discuss, while I agree that EmDrive uses hundreds watts, the EagleWorks device just used 17 Watts.
It is not far from the power needed by an iPhone cellular 3G emitter (max 5 Watts but the emitter is quite inefficient).
And we don't know the circuit purpose and design where a capacitor was used, so we can't make any prediction about what power this capacitor must support. This kind of capacitor (wet or solid) is not used to filter out gigahertz.
But that's not my point, it was about technology of capacitors, not about the specific value of capacitance nor the typical power it can support. iPhones as most other consumer devices use solid polymer capacitors.
Title: Re: EM Drive Developments
Post by: Stormbringer on 09/03/2014 12:02 pm
I thought it was tested in a vacuum chamber.
Yup, bat at 1 atmosphere.

Capacitors couldn't take vac, IIRC.

Cheers, Martin
That is true and kind of inexplicable, really. But Dr Woodward tested his version of this thing in a vacuum. conclusion: this general class of device works in a vacuum.
Title: Re: EM Drive Developments
Post by: sghill on 09/03/2014 12:49 pm
Radiometers do work in a vacuum, just not particularly well.

That's not the point here.  The point is that the "drive" may have inadvertently worked like a Crookes radiometer heat engine.  A Crookes radiometer stops working in a full vacuum because there are no air molecules for the radiant energy absorbed on black side of the radiometer to excite, and the friction of the spinner can't be overcome by the light pressure on the silvered side.  It works best in a partial vacuum (read the wiki article) and it also works backwards compared to what you'd expect from a light pressure powered solar sail.

In the case of the EMDrive test articles, if the microwaves created uneven heating of the interior surfaces at normal air pressure, those surfaces could have warmed the air molecules and created the thrust detected by the very sensitive torsion balance. 

If this was indeed the case, then if they repeat the experiment in a full vacuum, the thrust effect will go away.  If it doesn't go away, then perhaps they are on to something.
Title: Re: EM Drive Developments
Post by: JasonAW3 on 09/03/2014 01:49 pm
NASA has its own list of capacitors that includes aluminum capacitors with solid conductive polymer as the electrolyte material that are compatible with the wide range of requirements for working in space conditions.

BTW your iPhone and most modern miniaturized electronic devices use capacitors with the same technology because no bulky wet capacitor would fit the form factor.

On a completely unrelated topic, unfortunately this kind of capacitor fuels wars in central Africa.
Isn't this a far higher power level than iPhone?

Cheers, Martin

Wile I was in the NAVY, I saw solid capaciter units hooked up to the radar systems that would make you plotz!  These things were MONSTERS!

      I suddenly understood why we would sometimes find partially cooked dead birds up on the Radar antenna level on board ship.  And THIS was beck in the 1980's!
Title: Re: EM Drive Developments
Post by: Rodal on 09/07/2014 07:06 pm
I have concluded that thermal transient effects are a likely explanation for the measured deflections and forces in NASA's torsion pendulum experiments of the Q drives.  Explicitly, that they are the result of a shift in material location of the center of mass due to differential thermal expansion resulting from heating of the dielectric resonator which is positioned unsymmetrically.  If this explanation is correct, Dr. White still should also be able to measure (slightly lower) forces when he places the Q drive in a torsion pendulum in a vacuum.  However, if the Q drive were free in space (instead of supported from a pendulum), this transient, unsymmetric, thermal expansion would result only in a change in attitude (orientation).

I am posting here my letter to Dr. White in order to have a wider review of this explanation. 

Dear Dr. White,

I have read with appreciable interest your paper (co-authored with D. Brady, P. March, J. Lawrence, and F. Davies) titled "Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum", presented at the 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, July 28-30, 2014 in Cleveland, OH.

I have thought about what may be responsible for the measured displacement (and force) in your reported torsion pendulum experiments.  Air convection resulting from microwave heating of the air surrounding the Q-drives has been suggested by various people, as the air speed that can produce the measured force can be shown to be small.  You will be able to check whether air convection is responsible when you perform experiments in a vacuum (which I understand from your report was not possible because of the aluminum electrolytic capacitors that need to be replaced by capacitors that can work in a vacuum environment).

However, I have wondered how air convection could be responsible for the reproducible and fairly consistent levels of measured force pulse, as well as the fact that the experimental pulses are so well defined (and that it took practically no time to achieve the measured forces and to go back to zero upon ending the microwave pulse), and that turning the Q-drive around by 180 degrees resulted in practically the same force in the opposite direction.

Based on my experience conducting experiments at the Massachusetts Institute of Technology Aeronautics and Astronautics Department (for my S.B., S.M. and Ph.D. degrees at MIT) and later on at industrial R&D laboratories, I have arrived at the conclusion that transient thermal effects in your experiments should be carefully considered.

Indeed, after much thought and some calculations my conclusion is that the measured forces can quite likely be the result of transient thermal effects that very slightly shift the location of the center of mass in the material body of the Q-drive, due to unsymmetric thermal expansion, resulting from internal heating of the dielectric resonator in the Q-drive.

The center of mass changes location in the material body, with respect to body-fixed, Lagrangian coordinates, as it expands unsymmetrically.  If the body would be free (unrestrained) in space, this would result only in a change in attitude (orientation) of the body. If free in space, the spatial position of the center of mass will not change (with respect to an inertial frame of reference).  However, because the tested Q-drives were restrained, suspended from a support point in a torsion pendulum, the unsymmetric thermal expansion will generate a small measurable rotation and (torquing) force because the center of mass changes location in the material body as it expands unsymmetrically. 


Similar issues (thermal distortion resulting in changes in orientation) were experienced, for example in spacecraft, most prominently with the Messenger (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft that got closer to the Sun:  See:  http://messenger.jhuapl.edu/the_mission/publications/O'Shaughnessy_Pittelkau.2007.pdf

Interestingly, your paper points out the importance of the (Teflon) dielectric resonator concerning the experimentally measured forces:

<<The longer beam pipe is the RF drive antenna that in practice ends up being a ¼ wave resonance system in its own right and has a dielectric PTFE slug in the throat in both the slotted and null test article. It is this characteristic that became an item of further consideration after completion of the test campaign.>> (p.7)

<<There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber.>> (p.18)

<<We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust.>>( p.18)

It is noteworthy that the test conducted without the dielectric resonator resulted in no significant measurable force. 

My analysis of the reaction force that results from the greater thermal expansion of the drive adjacent  to the dielectric resonator shows that the reaction force should be in the direction towards the end that has no  dielectric resonator.  That is, if the dielectric resonator is to the right of the center of mass of the drive, the reaction force will be to the left,  and if the drive is positioned such that the dielectric resonator is located to the left of the center of mass of the drive, the reaction force will be to the right.  This agrees with all your experimental results.

My analysis of the reaction force that results from the greater thermal expansion of the drive adjacent  to the dielectric resonator also shows that if the drive were perfectly symmetric (for example having the dielectric resonator centered at the center of mass, or having identical dielectric resonators located at the same distance from the center in both directions), there would be no net thermal distortion forces as they would balance themselves out.  In other words, if the Q-drive would have the dielectric resonator in the middle, or have two identical dielectric resonators positioned at equal distances from the center of mass, there would be no measurable forces.

Heat is generated inside the dielectric resonator due to the dielectric loss ("tan delta") material property of the resonator.  This internal heat power is produced instantly as a result of the electromagnetic field but it takes a finite amount of time for the temperature to diffuse through the material and reach steady state in accordance with Fourier's equation of heat conduction, depending on the diffusivity of the material, and satisfying  the thermal boundary conditions (convection and radiation if the experiment takes place in air, and just radiation if it takes place in a vacuum).  Since the dielectric loss factor ("tan delta") is temperature dependent, the heat generated is also temperature-dependent, which introduces a nonlinearity in the solution of the differential equations for this problem.  As the polymer ("Teflon" PTFE thermoplastic Fluoropolymer) dielectric temperature rises, it expands both in its radial and longitudinal direction.  There is also a dynamic effect due to the inertial forces reacting to the sudden pulse, in addition to the torsional resisting force of the torsional pendulum.

The thermal expansion of the polymer dielectric resonator in the radial direction results in better contact and heat transmission to the copper structure of the drive.  It can be readily shown that the effect of air convection in this experiment should be small in comparison with thermal conduction.

The reaction force produced by unsymmetric thermal expansion is proportional to the second derivative of temperature with respect to time. 

To calculate how long it takes for the temperature distribution to reach steady state (and therefore for the second derivative of temperature with respect to time to become negligibly small) we may use the Fourier Number: the thermal diffusivity times the characteristic time divided by the square of the characteristic length.  It is known that steady state is typically reached for a Fourier number exceeding unity, that is, for the characteristic time exceeding the ratio of the square of the characteristic length divided by the thermal diffusivity.  The thermal diffusivity of Teflon is 0.124 (mm^2)/sec.   I could not find the dimensions of the Teflon dielectric resonator in the report.  I calculate that the time to reach thermal steady state exceeds 22 minutes if the characteristic length of Teflon is 0.5 inch (12.7 mm).  If the characteristic length of Teflon is 0.2 inch (5 mm), the time to reach steady state will exceed approximately 4 minutes.  If the characteristic length of Teflon is 1 inch (25.4 mm), the time to reach steady state will exceed 1 hour and 27 minutes.  We know from the report that the microwave pulse was maintained for only 35 seconds during the testing (see Fig.12, p.9 in the report).  Therefore, we know that the microwave pulse was maintained for an amount of time much shorter than the amount of time necessary for the temperature distribution to reach steady state in the Teflon dielectric resonator.

When the microwave power is turned off (Fig.12, p.9 of the report shows this happening 35 sec after it was turned on), the heat generating power suddenly becomes zero, and hence the second derivative of the temperature with respect to time (responsible for the reaction force) becomes negative when the microwave power is turned off, resulting in a force in the opposite direction as to when the microwave power was on. 

Since copper's Young modulus is about 300 times stiffer than Teflon's, and assuming that the Teflon, particularly as it expands radially, is in frictional contact with the surrounding copper, it makes sense to assume that the expansion of the Teflon dielectric resonator is restrained by the much stiffer copper.  Under that assumption, we can calculate the differential thermal expansion of the copper surrounding the Teflon as the product of the coefficient of thermal expansion of copper (16.6*10^(−6) 1/degC) times the longitudinal length of the Teflon resonator, times the "delta T": the temperature difference between the copper surrounding the Teflon and the rest of the structure. 

If the longitudinal length of the Teflon resonator is 1 inch (25.4 mm), the delta T necessary to produce a differential thermal expansion of 4 micrometers is only 9.5 deg C (17 deg F).  So it is quite possible to produce the measured deflections with a delta T in temperature of a few deg C.  If the Teflon is unrestrained by the copper, the required  delta T is 8 times smaller (since the coefficient of thermal expansion of Teflon is 135* 10^(−6) 1/degC, eight times greater than the coefficient of thermal expansion of copper).

I hope that these considerations, convince you (as has been my experience in testing at MIT and in industrial R&D) that thermal transient effects are important and therefore that it merits strong consideration that the measured deflections and forces in your torsion pendulum experiments of the Q drives are the result of a shift in material location of the center of mass due to differential thermal expansion resulting from heating of the dielectric resonator which is positioned unsymmetrically, as explained above.

Best regards,

Dr. Jose' J. Rodal
[email protected]
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/08/2014 08:45 am
Great post!
Welcome to the forum.
Title: Re: EM Drive Developments
Post by: Star One on 09/08/2014 03:42 pm

Great post!
Welcome to the forum.

Be interesting to hear about the response as I imagine that is just one amongst many, many pieces of correspondence that have no doubt been fired in his direction since the announcement.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/08/2014 05:59 pm
insteresting...

considering NSF user Stardrive (Paul March) works with Dr. Sonny White at Eagleworks Lab, specifically at the Q-Thrusters experiments (though if I am not mistaken he attributes the effects to Woodward Effect), I wonder if there would be any chance of him answering that.
Title: Re: EM Drive Developments
Post by: sghill on 09/08/2014 11:39 pm
insteresting...

considering NSF user Stardrive (Paul March) works with Dr. Sonny White at Eagleworks Lab, specifically at the Q-Thrusters experiments (though if I am not mistaken he attributes the effects to Woodward Effect), I wonder if there would be any chance of him answering that.

Well, I think Dr. Jose was mixing up EMDRIVE with Qthruster, but otherwise, let's hope for a response.
Title: Re: EM Drive Developments
Post by: Rodal on 09/09/2014 12:12 am
The authors (Brady, White, et.al.) of the paper ("Anomalous Thrust..."July 28-30, 2014, Cleveland, OH; AIAA/ASME/SAE/ASEE Joint Propulsion Conference) referred to ALL the tested thrusters, in general as  "potentially interacting with the quantum vacuum" in their abstract:

<<Test campaign results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma>> (Abstract)

or "potentially a Q-thruster":

<<... the RF launcher tube assembly with dielectric cylinder common to both the [Cannae] slotted and smooth test articles is potentially a Q-thruster where the pillbox is simply a matching network>> (p.10)

<<Tapered Cavity RF Evaluation, General Findings and Lessons Learned...We discovered early in the COMSOL® analysis process that just because you can achieve a great RF solution does not mean that it will be an ideal Q-thruster implementation.>> (p.18)

<<The near term objective is to complete a Q-thruster breadboard test article that is capable of being shipped to other locations which possess the ability to measure low thrust for independent verification and validation (IV&V) of the technology>> (p.21)

<<D. A. Brady... thanks Kent Joosten for his substantial contribution to Q-thruster mission analysis>> (p.21)

So, I intentionally adopted the author's general description of "Q-thruster" for all the devices tested by the authors  in their paper, because the different explanation I offer above (transient thermal unsymmetric expansion) for their experimental measurements applies equally well to all the different types of devices (both the Cannae-type and the Tapered Cavity ) tested by the authors.
Title: Re: EM Drive Developments
Post by: Rodal on 09/09/2014 12:52 am
Furthermore, Dr. White himself has repeatedly used the general word "Q-thruster" in the past to refer to ALL of the electromagnetic devices he has tested (including the EM Drive).   

For example see slide 40 of his presentation "WARP FIELD PHYSICS" (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf ) where he shows photographs for six different test campaigns for different devices (including the Boeing, Lockheed-Martin, EM Drive, Cannae, and two others) ALL under the same title of "Q-thruster Physics Data"
Title: Re: EM Drive Developments
Post by: Slyver on 09/09/2014 09:28 am
@Rodal

Can you provide the calculations you used for your analysis?

I attempted to do a quick model of the system with your ideas.  Using a few assumptions:

-- 25mm diameter x 5mm height cylindrical dielectric
-- 150mm length cavity
-- 5 degrees increase in temperature
-- Thermal expansion of the dielectric peaked instantly

I got a tangential torque of -5.6 x 10^-7 NM.  This is in the opposite direction, and two orders of magnitude less than the net force on the system.

The dielectric, assuming it was fastened to the top of the cavity (i.e. the face in the direction of the thrust) expands in the opposite direction (outward from the face) and thus changes the center of gravity of the system in the same direction as the expansion (and opposite of the measured thrust).

I did not run an analysis of the rate of thermal expansion of the dielectric, but you seem to have its net thermal expansion at the measured thrust (i.e. after 1s) ~ the same as its steady state expansion at the increased temp, and yet you state in your email only how long it takes to reach steady state.  The measurements in the data show both a very sharp increase in thrust (~1s from 0 to peak) and peak equal to initial thrust, suggesting by your model that there is no increase in thermal expansion between 1s and steady state (minutes).

I am only asking for detailed explanations (in both math and words preferably), not saying you are incorrect.  It is entirely possible I made mistakes in both my assumptions and my quick math.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/09/2014 02:38 pm
Rodal, I posted your question at Talk Polywell Forum, where Paul March (who works at Eagleworks Lab with Dr Sonny White, at the Q-Thrusters, and I guess also took part in the investigation of the EMDrive) sometimes reads stuff.


Here is his answer:

Quote
AcesHigh:

You can inform Dr. Rodal that most of the observed forces in the Eagleworks Lab frustum devices were prompt with the same rise and fall times as our electrostatically derived calibration forces and therefore are not thermal in origins. That's not to say we didn't see thermal effects, especially with input RF power levels greater than ~35W, but the thermal effects with these large copper plus dielectric test articles, (2.5 to 5.0kg), always take tens of seconds to develop and are easily distinguished from the prompt E&M or more interesting force inputs since they always exhibit exponential rise and fall times.

BTW, the copper frustum's temperature never rose more than 1.0 degree F. when using the above average power levels and test articles.

Best,
Paul March


Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/09/2014 02:46 pm
I have concluded that thermal transient effects are a likely explanation for the measured deflections and forces in NASA's torsion pendulum experiments of the Q drives.  Explicitly, that they are the result of a shift in material location of the center of mass due to differential thermal expansion resulting from heating of the dielectric resonator which is positioned unsymmetrically. ...

I hope that these considerations, convince you ... that thermal transient effects are important and therefore that it merits strong consideration that the measured deflections and forces in your torsion pendulum experiments of the Q drives are the result of a shift in material location of the center of mass due to differential thermal expansion resulting from heating of the dielectric resonator which is positioned unsymmetrically, as explained above.

Thank you very much for the quite readable analysis.

1.  Could you provide your calculations, following the order of your correspondence, perhaps tagging the calcs to the paragraphs?

2. It seems clear that vacuum testing of the device would be necessary.  Could you describe or sketch a possible experimental mechanism which would more closely simulate an unrestrained body?

3. Is the torsion pendulum the only way to test a device of this sort on Earth?

4.  How crucial is the dimension of the Teflon resonator to your argument?
Title: Re: EM Drive Developments
Post by: aceshigh on 09/09/2014 03:05 pm
@John Fornaro: I just posted an answer by Paul March, who works with Dr Sonny White, regarding Radal's questions.


--------------------------------

kinda off-topic, but is Dr Rodal's first name (José) of portuguese or spanish origin? It changes the way the J is pronounced (if portuguese, it´s similar to english J in Joseph, not the SAME sound, but closer to it than to Spanish J)
Title: Re: EM Drive Developments
Post by: sghill on 09/09/2014 03:19 pm
@John Fornaro: I just posted an answer by Paul March, who works with Dr Sonny White, regarding Radal's questions.

Irrespective of the science, what an awesome use of this forum- and thread!  Thanks to Aces, and John, and Dr. Jose, and Paul for all your contributions!!

How exciting. :)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/09/2014 04:13 pm
Quote from: rodal
However, I have wondered how air convection could be responsible for the reproducible and fairly consistent levels of measured force pulse, as well as the fact that the experimental pulses are so well defined (and that it took practically no time to achieve the measured forces and to go back to zero upon ending the microwave pulse), and that turning the Q-drive around by 180 degrees resulted in practically the same force in the opposite direction.

Quote from: March
You can inform Dr. Rodal that most of the observed forces in the Eagleworks Lab frustum devices were prompt with the same rise and fall times as our electrostatically derived calibration forces and therefore are not thermal in origins.

Rodal has noticed the "prompt" and "well defined" rise and fall times of the measured forces; that part at least, has not been overlooked, nor answered.  Rodal goes on to discuss the rather long times for the Teflon to achieve a thermal steady state, but what Rodal doesn't do is offer his suggestion as to the speed and dimension of the "reaction force" caused by the dielectric resonator, and how it relates to the prompt and well defined rise and fall times of the measured forces.

That's why I asked about the dimensions of the Teflon. 

In order for the device to operate for several days (as if it were flying to the Moon) it would have to be operated rather continuously, and there would be some kind of steady state operation that would have to be engineered.  But that would be a future game.
Title: Re: EM Drive Developments
Post by: Rodal on 09/09/2014 05:06 pm
I'm glad that I posted in this forum, great, quality feedback :D  Thanks to everyone for your comments.

I'll try to answer this evening when I have time available.


____________

@aceshigh, thank you for your initiative to pursue this with Paul March. Please thank him for his answer, which is much appreciated.  It would be great if you could pursue further answers to the following questions:

1) What was the length (between upper support and lower fixture point) of the pendulum ?

2) What was the total weight suspended on the pendulum ?

3) What were the different shapes (cylindrical, disc, etc. ?) and the dimensions of the Teflon dielectric resonators that were used in the experiments?

4) What were (all) the surface Boundary Conditions of the Teflon dielectric resonators ? how were the dielectric resonators put in position?

___________
@aceshigh: answering your off topic question, my first name is a geographic accident of being born in a country where (at that time) there was a law that everyone born there had to be given names chosen from a Government-provided list.  .  The "J" is pronounced as an "H":D
Title: Re: EM Drive Developments
Post by: aceshigh on 09/09/2014 05:33 pm
@aceshigh: answering your off topic question, my first name is a geographic accident of being born in a country where (at that time) there was a law that everyone born there had to be given names chosen from a Government-provided list.  .  The "J" is pronounced as an "H":D

if it´s pronounced as an english H, then I guess it´s of spanish origin. I asked because I am brazilian, and as a portuguese speaker, I have the tendency to read José with the portuguese J.

(google translate pronounciation button is very good for these matters, if you are curious)

I will forward your questions to Paul March. I am not sure he can answer all of them. I remember reading a couple of years ago that he had signed a non-disclosure contract with NASA or maybe with Dr White, which was when he stopped being active both here at Nasa Spaceflight Forum and TalkPolywell forum... he used to post LOTS of info about his workings with Dr James Woodward at Mach Effect and such.
Title: Re: EM Drive Developments
Post by: Rodal on 09/09/2014 07:38 pm
My understanding is that White et.al. used an inverted torsion pendulum for their experiments.  If there are Non Disclosure Agreements, they must deal with the inner workings of proprietary drives that were tested, but I imagine that the inverted torsion pendulum should NOT be part of these NDA's.  Since White et.al. published their experimental results performed at NASA, I would imagine that a description of the experimental procedure, most importantly the pendulum geometry, should be part of their description for the scientific/engineering community to review, and this would not be covered by NDA's.

My pendulum geometry questions are then more properly framed as follows:

1) What is the length of the inverted torsion pendulum between the lower torsional support and the upper centering bearing ?

2) What is the total weight of the upper portion: the tested object, its support table,  and any other fixtures and equipment on the table?

3) What is the maximum off-center motion allowed by the centering bearing ?

4) What is the spring constant (about a rotating axis normal to the vertical arm of the pendulum) of the bottom joint that tries to keep the inverted pendulum upright in a vertical position?
Title: Re: EM Drive Developments
Post by: aceshigh on 09/09/2014 08:01 pm
it´s possible Rodal. I already forwarded your previous questions to the Talk Polywell forums, but I also asked Dr Paul March if he could answer your questions directly here, so I can stop playing messenger boy haha ;)
Title: Re: EM Drive Developments
Post by: aceshigh on 09/09/2014 08:06 pm
Mr Chang from NextBigFuture already caught on to the interesting discussion going on between Dr Rodal and Dr March and posted an update at his site:
http://nextbigfuture.com/2014/09/nasa-cannae-drive-and-emdrive.html
Title: Re: EM Drive Developments
Post by: Rodal on 09/10/2014 12:43 am
I attempted to do a quick model of the system with your ideas.  Using a few assumptions:.....
I got a tangential torque ... in the opposite direction, and two orders of magnitude less than the net force on the system.
@Slyver

First of all thank you for taking the time and initiative to do your own independent modeling.  We face at least three problems in modeling this experiment: 1) the NASA paper does not describe the experiment with enough detail that we can model it without making a number of assumptions (hopefully we will get some more details in the future), 2) the experimental set-up is not trivial (for example: the inverted pendulum) and 3) the measured force is extremely small so a number of normally negligible effects can be responsible.   By working independently yet asking questions about our models perhaps we can eliminate some possibilities, correct our models and narrow down the possible explanations.

So let me start with the force that I did not explicitly mention in my write-up nor it appears in yours: gravity.  Did you model the inverted torsion pendulum?

- I am multi-tasking  - running some programs while I'm writing this, so I will do this in short segments.  The next one to follow discussing my inverted pendulum  modeling

Title: Re: EM Drive Developments
Post by: Rodal on 09/10/2014 12:56 am
@Slyver  (CONTINUED)

The motion of the inverted torsional pendulum is, in general. the combination of 3 types of oscillation: 1) Torsional,
2) Swinging and 3) Bouncing.  I neglected the (vertical) bouncing oscillation under the assumption that the pendulum's vertical arm (some people call it "leg") is stiff enough (in relation to the supported mass) so that the longitudinal "bouncing" vibration displacements are negligible (of course, we would need to double check this assumption once we know the supported mass and the arm's dimensions and material construction).
Title: Re: EM Drive Developments
Post by: Rodal on 09/10/2014 01:10 am
@Slyver  (CONTINUED)

I modeled the swinging oscillation of the inverted pendulum with a natural (angular) frequency

omega= Sqrt[(k/M)-(g/l)]

where:

k= spring constant (about a rotating axis normal to the vertical arm of the pendulum) of the bottom joint that tries to keep the inverted pendulum upright in a vertical position

M=total supported mass ( total weight of the upper portion: the tested object, its support table,  and any other fixtures and equipment on the table)

g=acceleration of gravity

l=length of inverted pendulum's arm between the lower torsional support and the supported mass

Title: Re: EM Drive Developments
Post by: Rodal on 09/10/2014 01:19 am
@Slyver  (CONTINUED)

In the above formula, I neglected the mass of the pendulum's arm "mArm".  If this mass is not negligible, then the angular frequency of swinging oscillation would be:

omega= Sqrt[(k-(g/l) ( M+(mArm/2) ) )  /   ( M+(mArm/3) )]

where:

k= spring constant (about a rotating axis normal to the vertical arm of the pendulum) of the bottom joint that tries to keep the inverted pendulum upright in a vertical position

mArm=mass of the pendulum's arm

M=total supported mass ( total weight of the upper portion: the tested object, its support table,  and any other fixtures and equipment on the table)

g=acceleration of gravity

l=length of inverted pendulum's arm between the lower torsional support and the supported mass
Title: Re: EM Drive Developments
Post by: Rodal on 09/10/2014 01:31 am
@Slyver  (CONTINUED)

If the supported mass is small enough, then omega ( the angular frequency of swinging oscillation ) is a real positive number and the pendulum may exhibit a harmonic swinging motion (hopefully of very small amplitude).  If the supported mass is too large, omega is an imaginary number (or in other words, the expression inside the square root becomes negative) then the pendulum will collapse, falling over over towards one side against the centering bearing.
Title: Re: EM Drive Developments
Post by: Rodal on 09/10/2014 01:44 am
@Slyver  (CONTINUED)

The swinging pendulum motion is, in principle, around two orthogonal swinging directions.

___________
There are other possible frequencies of swinging oscillation which I did NOT model.  For example if the pendulum arm bends at the upper end, one would also expect a composite pendulum with another frequency. 

I mention this because the NASA authors mention:

<<If needed, ballast is added to the pendulum arm to eliminate moments that affect the neutral position of the pendulum arm.>> (p.5)

In any case it is interesting that they are conscious that their experimental inverted pendulum set-up is capable of having moments affecting the neutral position of the pendulum arm (even if it doesn't bend).  The authors took care of using ballast to eliminate these moments at start-up (however, we have to calculate whether such moments affecting the neutral position of the pendulum arm are significant due to unsymmetric thermal expansion).  It is evident that "k/M" is not infinite !. The bearings allow some off-center motion. Their inverted pendulum is capable (as all inverted pendulums are) of swinging oscillations.
Title: Re: EM Drive Developments
Post by: Rodal on 09/10/2014 02:56 am
@Slyver  (CONTINUED)

So (neglecting the mass "mArm" of the arm) , for the swinging motion of the inverted pendulum, we have two forces acting along the swinging arc, in opposite directions:

1) Due to gravity: the force component tangent to the swinging arc,
Fg = - M g theta ~ - M g x / l ,
which is de-stabilizing: it has the opposite sign to the force of gravity in the simple pendulum

and

2) Due to the elastic spring "k" (about a rotating axis normal to the vertical arm of the pendulum)  that tries to keep the inverted pendulum upright in a vertical position,
Fk = + k l theta ~ + k x

where the swinging angle can be approximated as

theta ~ x / l 

where "x" is the horizontal displacement and "l" is the length of the inverted pendulum's arm between the lower  support and the upper supported mass

For the inverted pendulum to work as designed, the elastic spring force (that tries to keep the inverted pendulum upright in a vertical position) must be greater that the de-stabilizing force of gravity, otherwise, as already discussed the pendulum will collapse towards one side:

Fk  > Fg

or

 k l  > M g

or

( (k / M) - (g / l ) ) > 0

Title: Re: EM Drive Developments
Post by: Rodal on 09/10/2014 03:09 am
I'll continue this tomorrow...  as well as answering the other questions, from John Fornaro and others
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/10/2014 12:26 pm
Just for grins, here is a random linear actuator which gets 4N of "peak force" for 28 watts.
Title: Re: EM Drive Developments
Post by: Star-Drive on 09/10/2014 12:42 pm
it´s possible Rodal. I already forwarded your previous questions to the Talk Polywell forums, but I also asked Dr Paul March if he could answer your questions directly here, so I can stop playing messenger boy haha ;)

AcesHigh and Dr. Rodal:

Interesting thread, but you would have saved yourselves a lot of wasted effort if you had first obtained the needed details before going so far down this analysis rabbit trail.  That said, yes I'm covered by a number of NDA's that do not allow me to talk about third party test articles.  However since Dr. White has already published several papers on the Eagleworks Lab home-grown torque pendulum thrust measurement system and frustum cavity test articles, I think I can comment at least on those topics when my time permits.

Now in regards to the Eagleworks Lab's torque pendulum, it is a conventional horizontal torque pendulum with two C-flex torsional bearing blocks with one bearing block mounted directly above the torque pendulum arm and the other below it on the same rotational axis.  From memory the distance between the bearing blocks to the torque pendulum arm is around 4.0", but I'll re-measure it today to make sure.  The length of the aluminum pendulum arm is 24.00 inches with the center of rotation being offset from its center of mass by about 4.0" before adding additional masses, but again I'll re-measure it today to get its current dimensions.  The Riverhawk C-flex torsion bearing's spring constant is a nominal 0.007 in-Lb/deg., but that varies with the mass load mounted on the torque pendulum arm and selected balance point of the test article mass and its counterbalance mass on the other end of the pendulum arm relative to the torque pendulum’s center of rotation.  Each bearing block is rated for ~25.0 Lb of vertical mass load, so we nominally restrict ourselves to a 25 pound total load limit on the torque pendulum arm to give ourselves a 100% support mass margin.

More later for I now have to get to work...
Title: Re: EM Drive Developments
Post by: Rodal on 09/10/2014 10:13 pm
@Paul March,

What are the units of the Electric Field (shown ranging from 0 to 3000) in Fig. 14 ?

titled "Cross section of test article (left) and close up of fields in RF drive pipe (right)", from the <<Computer modeling of the electric field within the pillbox and beam pipe (using COMSOL Multiphysics® software>> 

on page 10 of your paper (with Brady, White, et.al.)

"Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum" July 28-30, 2014, Cleveland, OH,  50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference
Title: Re: EM Drive Developments
Post by: Star-Drive on 09/10/2014 11:32 pm
@Paul March,

What are the units of the Electric Field (shown ranging from 0 to 3000) in Fig. 14 ?

titled "Cross section of test article (left) and close up of fields in RF drive pipe (right)", from the <<Computer modeling of the electric field within the pillbox and beam pipe (using COMSOL Multiphysics® software>> 

on page 10 of your paper (with Brady, White, et.al.)

"Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum" July 28-30, 2014, Cleveland, OH,  50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference


The units for all the E-field measurements in our 2014 JPC paper is volts per meter (V/m).

As to the torque pendulum dimensions, the center of the two C-flex bearing blocks is 2.38" above and below the centerline of the 24.00" long by 1.50" square aluminum pendulum arm.  The long end of the pendulum arm is 15.5" from the torque pendulum's center of rotation, which makes the other short-end of the pendulum arm 8.5" from the center of rotation.  And all the pendulum's aluminum structural elements are electrically bonded together and then grounded to the vacuum chamber's 304 alloy stainless steel walls that is in turn grounded to the facility's green wire safety ground system.  This grounding arrangement's function is to preclude the buildup of electrical patch charges on the various parts of the pendulum and vacuum chamber during operations.

BTW, the reason we didn't test in vacuum for these test series was that our 35W RF amplifier, that was mounted on the torque pendulum arm as the counterbalance mass for the test articles, was that it's electrolytic capacitors would pop at the low pressures, thus disabling it.  We have since obtained two ~100W RF amplifiers that are hermetically sealed that will allow us to test down to ~5x10^-6 Torr vacuum pressures in the near future, at least once we sort out our current phase locked loop design issues.

Best,
Title: Re: EM Drive Developments
Post by: Rodal on 09/11/2014 12:50 am
@Paul March,

An elegant way to show that the experimentally measured pulse is NOT due to thermal effects is to make the following calculations based on the electric field shown in Fig. 14, titled "Cross section of test article (left) and close up of fields in RF drive pipe (right)", from the <<Computer modeling of the electric field within the pillbox and beam pipe (using COMSOL Multiphysics® software>>  of page 10 of your 2014 JPC paper co-authored with Brady, White, et.al. and to compute the maximum dissipated power as follows:

DissipatedPower = 2 Pi f (E^2) (permittivity of free space) (epsilon')(tan delta)

Taking the maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m , and the given frequency of 935 MHz, it immediately follows (for the Teflon PTFE dielectric resonator) that:


DissipatedPower [W/m^3] = 2 Pi (935*10^6 1/s) (( 4.7189*10^4)^2) (8.85418782*10^(-12)) (2.1)(0.0003)

DissipatedPower =  72973  W/m^3 = 0.0729 W/cm^3

and then use this value to compute the temperature rise in Teflon (without any heat losses):

dT/dt = DissipatedPower / (HeatCapacity*Density)


dT/dt = ( 0.0729 W/cm^3 ) /( (1.3 J/(g deg C)) (2.22 g /cm^3 ))

dT/dt = 0.0253 deg C /s = 1.517 deg C /min

or in deg F:

dT/dt = 0.0455 deg F /s = 2.731 deg F /min



(Fron Fig. 12), the measured pulse's temperature rise takes about 4 seconds, during which time the maximum possible temperature reached is only 0.18 deg F.

Also, at the end of the whole 35 seconds pulse, the maximum possible temperature reached is just 1.59 deg F


Jose' Rodal

Title: Re: EM Drive Developments
Post by: Rodal on 09/11/2014 01:04 am
Also, since the coefficient of thermal expansion of Teflon PTFE is 135* 10^(−6) 1/degC,

and the maximum possible temperature rise is  dT/dt = 0.0253 deg C /s

during the 4 seconds rise, the maximum possible thermal strain expansion of the Teflon PTFE resonator is:


UnrestrainedThermalStrain = 4 s *( 0.0253 deg C /s ) * ( 135* 10^(−6) 1/degC ) = 0.00137 %

which is extremely small.  For example, if the Teflon dielectric resonator is 1 inch (25.4mm) long, the maximum possible (unrestrained) change in length during the 4 sec pulse rise is only: 0.347 micrometers.

Jose' Rodal

Title: Re: EM Drive Developments
Post by: Rodal on 09/11/2014 02:00 am
..the 24.00" long by 1.50" square aluminum pendulum arm...

Thanks Paul for all this information.  I am thinking of another explanation, and I have these further questions:

1) Several places in your report discuss the Magnetic Damper System:

<<Figure 3. Electrostatic Fins Calibration System and Magnetic Damper>> (p.4)

<<Whenever a force is induced upon the pendulum arm, the resultant harmonic motion must be damped. This is accomplished via the use of a magnetic dampening system (MDS) at the back of the test rig. Three Neodymium (NdFeB Grade N42) block magnets interact with the pendulum’s aluminum angle to dampen oscillatory motion.>> (p.4)

<<This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system>> (p.14)

<<Figure 20. Null Test on Torsion Pendulum – average null force is 9.6 micronewtons due to 5.6A DC current in power cable (routes power from liquid metal contacts to RF amplifier; interacts with magnetic damper system)>> (p.16)

QUESTIONS: 

A) Was the magnetic damper on at all times in the shown traces (for the calibration pulses as well as for the thrust pulses both to the left and right ?

B) What is the nature of the interaction << ....with magnetic damper system)>>  discussed in Fig. 20 (p.16) ?

C) Are you able to apply different levels of magnetic damping (and if so have you tested them, with what results) or all you are able to do is to have this level of magnetic damping either on or off ?

D) There is a range of thrust values that were measured for the same nominal conditions.  Were changes in the total supported mass and location of this mass made, and if so do they have any correlation with the range of thrust measured?

2) Do you know the cross-section of the 1.50" square aluminum pendulum arm ? (Is it solid, or if it is a channel, what are its internal dimensions?)

Jose' Rodal

Title: Re: EM Drive Developments
Post by: frobnicat on 09/11/2014 09:14 am
If the measured thrust pulse were due to displacement of a mass m relative to the fixation point of the device on the arm, a constant thrust (during the pulse) implies a constant acceleration of this mass (again, relative to the mobile arm) a=F/m, and an integrated displacement at the end of the pulse x = 1/2at² = 1/2 F/m t² = 0.064/m  (approx. with F=80µN and t=40s, and mass m given in kg). After this phase at constant acceleration, the displacement of mass would have to continue at constant velocity for some more time to mimic a sharp fall in thrust but not an opposite thrust pulse (has would be the case if displacing mass suddenly stopped from its integrated vt at velocity). So 0.064/m is a minimum displacement, and it's 6.4 cm assuming something 1kg is moving, or 6.4mm for 10kg. Even if a thermally expanding part of the device were driving a more massive part (not needing heating the whole mass to move it), the required displacement seems much too huge for a thermal expansion, given the scales and max temperatures overall.

Nice to have some first hand feedback on this thread.

Maybe I missed that but anyone inquired or commented on the apparently systematic slope changes (downward) after the relatively clean square thrust periods ? Is there a higher period (>200s) harmonic mode in the system that gives those overall slopes on the order of 1µN/s, or is this just long period "random drifts" due to sensitivity of system ? The charts show the signals measured relative to this slowly drifting baseline (drawn as dotted yellow curve, like piecewise linear best fits). The statistically small sample makes hypothesis risky, but visually there appear a systematic downward change of slope after thruster's pulses, and (also not quite clearly) no slope changes after the (arguably smaller magnitude) 30 µN calibration periods. What is the relevance or irrelevance of this drifting baseline ?

edit : I meant "has would be the case if displacing mass suddenly stopped from its integrated at velocity"
Title: Re: EM Drive Developments
Post by: Star-Drive on 09/11/2014 12:39 pm
..the 24.00" long by 1.50" square aluminum pendulum arm...

Thanks Paul for all this information.  I am thinking of another explanation, and I have these further questions:

1) Several places in your report discuss the Magnetic Damper System:

<<Figure 3. Electrostatic Fins Calibration System and Magnetic Damper>> (p.4)

<<Whenever a force is induced upon the pendulum arm, the resultant harmonic motion must be damped. This is accomplished via the use of a magnetic dampening system (MDS) at the back of the test rig. Three Neodymium (NdFeB Grade N42) block magnets interact with the pendulum’s aluminum angle to dampen oscillatory motion.>> (p.4)

<<This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system>> (p.14)

<<Figure 20. Null Test on Torsion Pendulum – average null force is 9.6 micronewtons due to 5.6A DC current in power cable (routes power from liquid metal contacts to RF amplifier; interacts with magnetic damper system)>> (p.16)

QUESTIONS: 

A) Was the magnetic damper on at all times in the shown traces (for the calibration pulses as well as for the thrust pulses both to the left and right ?

B) What is the nature of the interaction << ....with magnetic damper system)>>  discussed in Fig. 20 (p.16) ?

C) Are you able to apply different levels of magnetic damping (and if so have you tested them, with what results) or all you are able to do is to have this level of magnetic damping either on or off ?

D) There is a range of thrust values that were measured for the same nominal conditions.  Were changes in the total supported mass and location of this mass made, and if so do they have any correlation with the range of thrust measured?

2) Do you know the cross-section of the 1.50" square aluminum pendulum arm ? (Is it solid, or if it is a channel, what are its internal dimensions?)

Jose' Rodal


Answers to Dr. Rodal's Questions:

1 A & B & C) The Eagleworks Lab's magnetic damper uses three or four permanent magnets mounted on the fixed portion of the torque pendulum with a partial steel flux return that generate a constant B-field that in turn interacts with a 1.5" wide by 0.25" thick aluminum angle that is mounted to the back side of the moving aluminum arm of the torque pendulum.  Thus the B-field generates damping eddy currents in the moving aluminum angle whenever it moves relative to the B-field.  So yes it was designed to be active at all times throughout the entire stroke of the torque pendulum.  This magnetic damper system provided less than critically damped performance requiring approx. 1.5 cycles to damp out any induced motion in the pendulum arm.  The natural oscillation period of the pendulum arm when loaded with the RF amplifier, its RF plumbing and the test article was around 4.5 seconds.

D) The mass on the torque pendulum and its orientation was held constant for a particular test series.  Of course slight changes to the placement of the test article occurred when we reversed the thrust vector of the test articles, but we tried to keep the balance approximately the same for all data runs.

 In regards to force calibration we used a set of NIST traceable, pre-calibrated meshed electrostatic fins that provided a constant attractive force between the fin pair for a given applied calibration voltage over a 25% to 75% meshed fins range.  This feature allows us to generate the same calibration force independent of the loading of the torque pendulum's C-flex torsional bearings or how much the fin set is meshed within the noted fin mesh range.  Thanks go to our previous Co-Op, Bill O'Neal, who is now at Purdue University for this design. 

2) The Fastek 6063-T6 aluminum extrusion cross section used for these tests is shown in the report or at its vendor and suppliers.

See:http://www.faztek.net/ and 
http://www.amazon.com/Faztek-15QE1515UL-Aluminum-T-Slotted-Extrusion/dp/B008MQA11C 
Title: Re: EM Drive Developments
Post by: Rodal on 09/11/2014 04:15 pm
3. Is the torsion pendulum the only way to test a device of this sort on Earth?

There are several types of small thrust measurement devices.   NASA has a rich tradition, with the Micropound Extended Range Thrust Stand (MERTS) at NASA' Goddard Spacefliight Center and RCA-New Jersey-Lab (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19830026735.pdf ) (circa 1980 ?) and
Haag's plasma thrust stand at NASA's Lewis Research Center (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960008159.pdf ) in 1995. 


Basically there are three main types of devices (and subcategories):

1) The hanging pendulum -either in torsion or swinging-.  Torsion hanging pendulums have been used for sensitive, groundbreaking experiments in physics in several labs, for example, for gravity (inverse square law) and Casimir force measurements.

2) The inverted pendulum -either in torsion or swinging-.  An inverted torsion pendulum has been used by NASA Eagleworks under Dr. White.

3) The torsional style -not to be confused with torsion pendulums ! -, which uses a counterweight on one side to counteract the weight of gravity on the other side, to keep it in a neutral position.  In the neutral position there should be a horizontal line connecting the weights (that are located to the left and to the right of the central pivot point).  Its sensitivity depends on the stiffness of the pivot and the arm lengths.

The hanging pendulum and the inverted pendulum have advantages and disadvantages when compared to each other.

STABILITY: The hanging pendulum balance is inherently stable because gravity stabilizes any swinging oscillations it may experience. The inverted pendulum on the other hand is inherently unstable since the gravitational force is such as to swing the pendulum off-center.   Therefore, the inverted pendulum needs some form of upright stabilization: mainly, the bending stiffness of the vertical arm and the magnetic damping to eliminate parasitic frequencies.   (The critical ratio is the ratio of the bending stiffness divided by the supported mass as I have shown in a previous post). Magnetic dampers are also used for hanging torsion pendulums but the inverted torsion pendulum (due to its inherent instability) has more complicated nonlinear dynamics (capable of chaotic motions with attractors).


SENSITIVITY:  The sensitivity of the hanging pendulum is hindered by the length of the arm -an important issue when trying to make measurements inside a vacuum chamber, since the balance has to fit inside it-.   The inverted pendulum can be made sensitive by matching the pivot's bending stiffness with the gravitational force, but this depends on: A) the supported mass, B) the bending stiffness of the pendulum arm (for swinging motion) and C) the length of the pendulum arm, as I have shown in a previous post.
Title: Re: EM Drive Developments
Post by: Rodal on 09/11/2014 04:20 pm
The quoted article by Brady, White, March, et.al., has an outstanding ending, that reads:

<<The current plan is to support an IV&V test campaign at the Glenn Research Center (GRC) using their low thrust torsion pendulum followed by a repeat campaign at the Jet Propulsion Laboratory (JPL) using their low thrust torsion pendulum. The Johns Hopkins University Applied Physics Laboratory has also expressed an interest in performing a Cavendish Balance style test with the IV&V shipset.>>
Title: Re: EM Drive Developments
Post by: Rodal on 09/11/2014 04:37 pm
Under Professor Manuel Martinez-Sanchez (an authority in electric propulsion) students at MIT have developed different thrust balances (usually developed for their Master Thesis).

One of these balances, built a few years ago under Professor Manuel Martinez-Sanchez, had these advantages:
 
A) the ability to produce a translation, as opposed to a rotation under thrust. (Recall that the thrust balances used by Dr. White and the ones planning to be used at Glenn, JPL and John Hopkins, actually measure a rotation rather than a translation). This was accomplished by including  flexible points of known stiffness at both the top and the bottom of the stand. The engine (whose thrust is being measured) remains horizontal as the stand tilts, keeping the thrust in a known angular direction and reducing the uncertainty in the stand's measurements.

B) The MIT inverted pendulum thrust balance includes a counterweight.  It has the effect of removing (or diminishing) the sensitivity to base vibrations by creating a statically balanced design. The counterweight also removes the gravity term from the denominator of the equation for the displacement. This is very important for nonlinear dynamics stability reasons (attractors).

However my understanding is that the sensitivity of the MIT thrust measurement balance may be insufficient for Dr. White's purposes, my recollection is that the MIT Martinez-Sanchez balances range up to dozens of milliNewtons (?) with an uncertainty of a few hundred microNewtons which is sufficient for conventional electric thrusters but it is way insufficient for Dr. White's purposes.  But anyone interested should check with MIT's Aero & Astro department as they may have newer and/or more sensitive thrust balances and my understanding of their sensitivity may be incorrect !.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/11/2014 05:53 pm
at NextBigFuture, GoatGuy (a known Skeptic and quite good at demolishing a lot of nonsensical stuff with good science and calculations, but also sometimes he turns his cannons even to science done well just because he doesn´t believe it), posted some stuff

Quote
feel like I'm watching a dumbshow.

So… anyone … and I mean anyone at all … do you think that there would be a electromechanical interaction of a big honking antenna inside a big conductive metal container? Ya think? No? Why not!?

I know this is somewhat the "wrong analogy" but consider, just for a second: you have a magnet that you've attached to a string. you want to measure its torsion. You place it in a copper vacuum chamber a diameter or two larger than the magnet. You start it swinging. What's the first thing that happens?

The magnet induces substantial eddy currents in the surrounding copper enclosure. This in turn generate counteracting magnetic fields. These in turn rapidly quench the oscillation of the magnet. There's real force there. REAL. Indeed, this arrangement (inverted) is used to quench the oscillations of a beam-balance's beam. Force, without stiction.

What I see is a nice big copper horn, inside a nice big metal cylinder (the vacuum cylinder). It is supposedly a high Q device, so that the microwave field will be approximately Q • P watts in energy density. Since those watts have to "go somewhere", guess what … they fill the cylinder, which has the geometry of a particularly nice Faraday shield. The chamber is not anechoic, so, they just bounce around like mad, making nodes and antinodes.

Now you think those nodes and antinodes aren't going to interact mechanically with all that metal stuff which is the apparatus?

I bet when the thing is lofted (at GREAT NASA expense) to space, it'll fail to deliver the micronewtons that it supposedly delivers. Or, to put it differently, it'll be one of the greatest days of experimental physics if it does develop the nanonewtons, when free-floating in space.

And it will be dâmned easy to measure, too. Send it off at a few meters per second "away" before turning on power. Get a good fix on its ultra-precise transmitter (laser). Turn on power. Watch it accelerate away by observing the doppler shift in the laser (sensitive to micrometers per second per second). Turn it off. Watch the change. Turn it on, watch the change. Leave it on until the power supply quits. Measure the ΔV again. It should mathematically prove, or disprove the effect.


Quote
And PS: Whenever I see in an article the stretch of imagination being used to build missions to Deimos in 50 days, I just want to puke. Its like … I need to write a book … “Seriously Bogus Science” or something.

The science which is serious enough to with straight-face, entertain all these creative things, without being critical enough of the experimental "conditions" to detect the systematic error of reasoning contained therein. The kind of science which is serious enough to pander Mills' endless succession of tripe-papers building on prior tripe-papers, purporting to have come up with a form of hydrogen in a degenerate state, that if it could exist at all would be the most common form of the stuff, and the whole Universe would have collapsed, before it was even the size of a watermelon. Oh, darn.

It is as if simply talking, and talking, and talking some more about “Q-thrusters” is somehow making them plausible, and is arguing away the systematic errors.

Folks, it is not. You don't measure micro-earthquakes during a major one. In electrical engineering as well as quantitative statistics of measurements, its called "signal to noise ratio" and "systemic errors".

Quote
To buy a $61,000,000 per lob launch-window with SpaceX, and to lob a nice space-worthy version of the device out there, to see how it works. $61,000,000 may sound like a lot to us groundhogs, but in space sciences, this is almost a rounding error. Maybe 3 rounding errors.

Furthermore, the expense is so minor, that one might reasonably get the trip "for free" from SpaceX themselves, as they clearly need to have "live fire" tests of their Falcon Heavy rocket, upcoming.

Let's say the testbed costs about a million to make competently. With 2 parts, with nice lasers, with big batteries, and all that. The thing on the test-bed didn't look like it would have cost more than $25,000 to make. I mean, under 100 watt transmitting tubes, at low gigahertz frequencies, and a bunch of commonplace copper to hold it all together. So, the test thing will be cheap 'n' dirty.

IF the Falcon Heavy launch is successful, then hey … the science cost $1,000,000. If it fails, then build another one at 10% the price (now that the kinks are worked out), and try again. SpaceX won't be put out, they can tolerate the extra (good for them) mass of a the test-bed.

If they want to get really edgy, then incorporate a bunch of micro-satellite projects from school-kids across the land. You know, growing beans in space, and whether milk will make graham crackers turn to mush in zero G.

LOL

Title: Re: EM Drive Developments
Post by: Hanelyp on 09/11/2014 07:24 pm
I'm not quite following GoatGuy's reasoning, but there are issues that can arise from a high-Q RF system.  My own focus of concern is unbalanced forces from RF in the feed line.  Without knowing the routing of the feed line I can't evaluate these potential errors properly, but plausible case can easily produce the force levels I've seen cited.
Title: Re: EM Drive Developments
Post by: Star-Drive on 09/11/2014 08:02 pm
If the measured thrust pulse were due to displacement of a mass m relative to the fixation point of the device on the arm, a constant thrust (during the pulse) implies a constant acceleration of this mass (again, relative to the mobile arm) a=F/m, and an integrated displacement at the end of the pulse x = 1/2at² = 1/2 F/m t² = 0.064/m  (approx. with F=80µN and t=40s, and mass m given in kg). After this phase at constant acceleration, the displacement of mass would have to continue at constant velocity for some more time to mimic a sharp fall in thrust but not an opposite thrust pulse (has would be the case if displacing mass suddenly stopped from its integrated vt velocity). So 0.064/m is a minimum displacement, and it's 6.4 cm assuming something 1kg is moving, or 6.4mm for 10kg. Even if a thermally expanding part of the device were driving a more massive part (not needing heating the whole mass to move it), the required displacement seems much too huge for a thermal expansion, given the scales and max temperatures overall.

Nice to have some first hand feedback on this thread.

Maybe I missed that but anyone inquired or commented on the apparently systematic slope changes (downward) after the relatively clean square thrust periods ? Is there a higher period (>200s) harmonic mode in the system that gives those overall slopes on the order of 1µN/s, or is this just long period "random drifts" due to sensitivity of system ? The charts show the signals measured relative to this slowly drifting baseline (drawn as dotted yellow curve, like piecewise linear best fits). The statistically small sample makes hypothesis risky, but visually there appear a systematic downward change of slope after thruster's pulses, and (also not quite clearly) no slope changes after the (arguably smaller magnitude) 30 µN calibration periods. What is the relevance or irrelevance of this drifting baseline ?


We found that this slope change after the test article and RF amplifer were turned on for 10-to-20 seconds was apprently due to IR radiation from the amplifier's heatsink that is mounted on the back side of the torque penlulum on an 8" square platform was affecting the top C-flex bearing more than the lower one.  We tried aluminum shielding the top bearing assembly from the heatsink IR source and managed to reverse the metioned thermal slope in the thrust plots, but after shielding the bottom one we could reduce it but still coundn't completely get rid of this thremal drift artifact.  Currently we are just living with it.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/11/2014 08:16 pm
3. Is the torsion pendulum the only way to test a device of this sort on Earth?

There are several types of small thrust measurement devices. ...

Hey, thanks!  Great overview! 1, 2, & 4?

Best to ignore Goatguy ...

Sheesh, what a diatribe.  Speaking as a Capricorn, he is an embarrasment to my sign.

Still, a pet peeve of mine regarding these not yet proven technologies is the discussion about future "expectations", based on "theoretical models", and the like.

Quote from: the Brady, White, March paper
Based on test data and theoretical model development, the expected thrust to power for initial flight applications is expected to be in the 0.4 newton per kilowatt electric (N/kWe) range, which is about seven times higher than the current state of the art Hall thruster in use on orbit today.

The following predictions of missions to Saturn and all strain credulity, because they are merely the application of numbers to an equation, and do not flesh out the many requirements needed to actually carry out one of these missions, other than the single metric of "0.4 newton per kilowatt electric (N/kWe)".

It's not acceptable to handwave such missions into a suggested plausible existance based only on "theoretical models".  It's not like the technology, if proven, has no perceived utility.

Anyhow, it is fascinating to follow the real discussion going on above.

Oh.  And I can easily lowball your sister. I'll run those ads for $5M.
Title: Re: EM Drive Developments
Post by: Star-Drive on 09/11/2014 08:25 pm
I'm not quite following GoatGuy's reasoning, but there are issues that can arise from a high-Q RF system.  My own focus of concern is unbalanced forces from RF in the feed line.  Without knowing the routing of the feed line I can't evaluate these potential errors properly, but plausible case can easily produce the force levels I've seen cited.

Please note that the entire RF system inlcuding its voltage controlled oscillator, phased locked loop, RF amplifier, RF coupler and coaxial transmission lines are hard mounted on the moving torque pendlum arm with the test artricle as it would be in flight.  The only power lines that comes across the liquid metal contacts (LMC) are the +5.0Vdc control and +28.0Vdc and their associated ground power lines for each circuit.  The Maxwell stress forces created in the LMC pots due to these dc power currects are calculated to be in the nano-Newton range and just act to restore the LMC metal pins to the center of the LMC pots that hold the Galanstan.  In otherwords these Maxwell centering stress forces just increase the effective C-flex spring constants by less than a tenth of a percent even when drawing ten amps through the plus and minus 28Vdc bus wires.  And yes, all these power wires are twisted and and shielded throughout their runs to cancel out most of B-fields associated with the RF amplifer and control power feeds.  Even with all that though, we appeared to still have a small residual interaction between these stray power line shield B-fields interacting with the stray B-fields from the magnetic damper, so we've already upgraded the magnetic damper design to further reduce this problem.  I've attached a couple of slides with the new magnetic damper design and buildup pictures.
Title: Re: EM Drive Developments
Post by: Rodal on 09/11/2014 08:48 pm
@Star-Drive (Paul March)

Concerning

<<The current plan is to support an IV&V test campaign at the Glenn Research Center (GRC) using their low thrust torsion pendulum followed by a repeat campaign at the Jet Propulsion Laboratory (JPL) using their low thrust torsion pendulum. The Johns Hopkins University Applied Physics Laboratory has also expressed an interest in performing a Cavendish Balance style test with the IV&V shipset.>>

Of course, any and all further independent testing is great and should be greatly encouraged.  For the reasons I pointed out previously, I think that it is most crucial to test in a different type of thrust balance, and of the ones discussed above (GRC, JPL and John Hopkins) it looks like the Johns Hopkins University Applied Physics Laboratory Cavendish Balance style test would be the most different, and therefore the most interesting.

Title: Re: EM Drive Developments
Post by: frobnicat on 09/11/2014 10:56 pm
Maybe I missed that but anyone inquired or commented on the apparently systematic slope changes (downward) after the relatively clean square thrust periods ? Is there a higher period (>200s) harmonic mode in the system that gives those overall slopes on the order of 1µN/s, or is this just long period "random drifts" due to sensitivity of system ? The charts show the signals measured relative to this slowly drifting baseline (drawn as dotted yellow curve, like piecewise linear best fits). The statistically small sample makes hypothesis risky, but visually there appear a systematic downward change of slope after thruster's pulses, and (also not quite clearly) no slope changes after the (arguably smaller magnitude) 30 µN calibration periods. What is the relevance or irrelevance of this drifting baseline ?


We found that this slope change after the test article and RF amplifer were turned on for 10-to-20 seconds was apprently due to IR radiation from the amplifier's heatsink that is mounted on the back side of the torque penlulum on an 8" square platform was affecting the top C-flex bearing more than the lower one.  We tried aluminum shielding the top bearing assembly from the heatsink IR source and managed to reverse the metioned thermal slope in the thrust plots, but after shielding the bottom one we could reduce it but still coundn't completely get rid of this thremal drift artifact.  Currently we are just living with it.

Thank you for this answer.
This gives a sense of how sensitive is the system and hairy to calibrate and use.

If due to the generator's IR radiation this slope changing effect should then be the same with the Null Test RF load, but the 3 charts of fig.20 show disparate results, 11:13 downward trend after power off like ones of fig.19, 11:23 upward trend during power on and then resuming same slope as before, 11:28 no discernible change of slope at all during power on neither after power off. Unless the closely paced successive runs change the successive heat equilibriums/exchanges with hard to predict outcomes ? If there is long period complex drifts/swings in the system then I'm probably trying to guess at too few samples here... it's just frustrating to see those drifts at comparable magnitudes as the measured effect.

I understand that a thermally induced displacement of mass could mimic a sharp rise in thrust (as it would be the second derivative of temperature) but can't make it quantitatively, while a IR induced thermal effect on the spring constant of the bearings can reach the magnitude observed, but apparent thrust would then be proportional to temperature : couldn't explain the sharp rise has it would then imply instant rise of temperature.

Title: Re: EM Drive Developments
Post by: Star-Drive on 09/11/2014 11:22 pm
3. Is the torsion pendulum the only way to test a device of this sort on Earth?

There are several types of small thrust measurement devices. ...

Hey, thanks!  Great overview! 1, 2, & 4?

Best to ignore Goatguy ...

Sheesh, what a diatribe.  Speaking as a Capricorn, he is an embarrasment to my sign.

Still, a pet peeve of mine regarding these not yet proven technologies is the discussion about future "expectations", based on "theoretical models", and the like.

Quote from: the Brady, White, March paper
Based on test data and theoretical model development, the expected thrust to power for initial flight applications is expected to be in the 0.4 newton per kilowatt electric (N/kWe) range, which is about seven times higher than the current state of the art Hall thruster in use on orbit today.

The following predictions of missions to Saturn and all strain credulity, because they are merely the application of numbers to an equation, and do not flesh out the many requirements needed to actually carry out one of these missions, other than the single metric of "0.4 newton per kilowatt electric (N/kWe)".

It's not acceptable to handwave such missions into a suggested plausible existance based only on "theoretical models".  It's not like the technology, if proven, has no perceived utility.

Anyhow, it is fascinating to follow the real discussion going on above.

Oh.  And I can easily lowball your sister. I'll run those ads for $5M.

John:

"It's not acceptable to handwave such missions into a suggested plausible existance based only on "theoretical models".  It's not like the technology, if proven, has no perceived utility."

 The NASA managers who control the research dollars have to understand the value proposition in the pursuit of a new propulsion technology or they won't support developing it, period.  And no, they didn't at first perceive and appreciate the utility of this Q-Thruster or Dr. Woodward's near equivalent Mach-Effect Thruster (MET) technologies until we performed a whole family of Copernicus orbital scenarios conservatively based on same, which the JPC report just touched on.  It's really that simple and the managers have at least now been told the theoretical and developmental benifits and risks in the pursuit of this unproven propulsion science and technology, so they can now make an educated choice to pursue it or not based on our orbital analysis work and the current sad state of affairs in the US human spaceflight program.  In other words chemical rockets just won’t cut it going out past Mars even with a robust human spaceflight budget and positive direction from the Whitehouse!  If we could use nuclear rockets, other choices would be availabe for our propulsion needs, but sadly the nuclear propulsion venue is not available to the US space program due to political issues we all know of, unless of course a fusion power breakthrough shows up on our doorsteps...

Best,
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/12/2014 01:16 am
The NASA managers who control the research dollars have to understand the value proposition in the pursuit of a new propulsion technology or they won't support developing it, period.

Paul, thanks for the engagement.  I totally get the justification argument.  I mean, name one AIAA paper where, among the conclusions, they state; "No, thanks all the same, we got tons of money.  Really."

The fact of the matter is, all that we have is chemical rocketry, and that for the forseeable future.   Your all's effort seems appropriately funded, and you have your work cut out for you.  If the managers you are beholden to must be reminded at every turn that your work has significant potential, one has to wonder at their attention span.

At the same time, you are jumping, without justification in my mind, way too far into the speculative future.  Your task, as they say, is to float the damn thing on the tabletop.  Just get us and twenty tons of stuff to Luna, willya?  By a low energy orbit, if you can.  The rest will follow, but only after that useful demonstration

If Rodal's analysis is faulty, get into those mathematical weeds.  If he has pointed out a weakness in your procedures, acknowledge it and take steps to address his argument.
Title: Re: EM Drive Developments
Post by: Rodal on 09/12/2014 01:59 am
John (Fornaro) and Paul (March),

The experimental results and possible explanations are not trivial, addressing and studying them will take patience and time.  There are subtle issues involved because of the extremely small forces being measured. 

There is no hurry. 

I think that we have a great line of communications !.  Let's keep it going. :D


To Infinity and Beyond (or to wherever we can get with the propulsion we have)

Jose' Rodal

Look up at the stars. Try to make sense of what you see. Be curious.
Title: Re: EM Drive Developments
Post by: Star One on 09/12/2014 06:30 am
I hope this isn't inappropriate but can I just thank you all for your posting in this thread, hearing from people at the coal face of research has been fascinating to read even if as a lay person I've only understood about fifty percent of it.:)
Title: Re: EM Drive Developments
Post by: Star-Drive on 09/12/2014 12:58 pm
John (Fornaro) and Paul (March),

The experimental results and possible explanations are not trivial, addressing and studying them will take patience and time.  There are subtle issues involved because of the extremely small forces being measured. 

There is no hurry. 

I think that we have a great line of communications !.  Let's keep it going. :D


To Infinity and Beyond (or to wherever we can get with the propulsion we have)

Jose' Rodal

Look up at the stars. Try to make sense of what you see. Be curious.

Jose':

I've been involved in testing Dr. Harold Sonny White's Q-Thruster approach to exotic propulsion for seven plus years now, and Dr. James F. Woodward's Mach-Effect (M-E) work for sixteen years.  (I started down this road in March of 1998 while working for Lockheed-Martin at JSC working as an electrical engineer on the NASA Space Shuttle program.)  I summarize my M-E AKA Woodward Effect research in three STAIF papers published in 2004, 2006 and 2007.  I know Dr. Woodward's body of M-E work extensively having been to his lab at CSUF a number of times now, and IMO Woodward has been seeing real forces in his M-E Thruster (MET) experiments for years. 

These latest experimental results on the Q-thruster is just trying to take Jim's work one step further by attempting to quantize the gravitational field in a manner consistent with Quantum Mechanics (QM), Plasma Physics and General Relativity Theory (GRT).  In other words if you are not already familiar with this body of work that Dr. Woodward started in 1982, you need to perform due diligence in reading several of the papers that Dr. Woodward, Dr. White and I have written over this time period.  Primarily I'm just the electrical engineer turned experimental physicist that is trying to make this exotic propulsion business work, for without something like it, humanity is doomed to stay inside the asteroid belt for the foreseeable future.  In the meantime if you can't find the papers in question e-mail me a note and I'll be glad to get them to you.

Best,
Title: Re: EM Drive Developments
Post by: JasonAW3 on 09/12/2014 02:00 pm

"It's not acceptable to handwave such missions into a suggested plausible existance based only on "theoretical models".  It's not like the technology, if proven, has no perceived utility."

  It's really that simple and the managers have at least now been told the theoretical and developmental benifits and risks in the pursuit of this unproven propulsion science and technology, so they can now make an educated choice to pursue it or not based on our orbital analysis work and the current sad state of affairs in the US human spaceflight program.


So, unless I am VASTLY mistaken, the only real risks that I can see here are a possible waste of Time, Money and a small amount of resources while pursuing a phenomena that even NASA acknowledges as being "Interesting".  Should it be proven wrong, then I don't see any appreciable fallout, as everyone involved seems to be seeing what they are acknowledging as a real induced motion of some kind.

     If it proves wrong, there doesn't appear to be any attempt a fraud, so no one takes a hit for that, extensive precautions are being taken to ensure that no other inflences could be responsible for what is happening, and the worst fall out I can see is the equivelent of the loose connector in teh CERN laboritiries that made everyone think that they may have spotted FTL neutrinos.  Basicly, everyone said, "OOPS, our bad!" and pretty much went on from there.

     So, if this doesn't prove out, it would be much like Edison's 1000 failures before he perfected the Light Bulb. He didn't fail 1000 times, he simply found 1000 ways that the light bulb wouldn't work.

     With that in mind, I say go for it and let's see where this leads!
Title: Re: EM Drive Developments
Post by: aceshigh on 09/12/2014 02:25 pm
Paul March is one of the nicest guys around. I have seen him taking flak and never altering his manners.


GoatGuy at NBF (they made a new article with the things Paul just published above) is now saying it´s obvious the EM Drive (or any other propellantless drive) is a perpetual motion machine because using a simple mission to Saturn in less than a year proves the energy needed to get there is orders of magnitude larger than the electrical energy input.

Quote from: GG
Mission-to-Saturn.
286 days.

Half that is acceleration, and half is deceleration. It only makes sense to keep the thruster "on" the entire trip, to minimize trip time. Half is about 12,000,000 seconds. This is an important number.

Acceleration is 0.0091 m/s² Since V = at and we know both t and a, then V is about 109,000 m/s or 109 km/s. Awesome! I wonder how much kinetic energy it has? Well, that is Ek = ½mV² and our mass is 90,000 kg. OK, easy-peasy. That's then 537,000,000,000,000 joules. about 120 kilotons of TNT as kinetic energy. Impressive!

Now, let's see. 2,000,000 watts for 13,000,000 seconds is what... 26,000,000,000,000 joules. Well then ... it looks like our spacecraft has 20.6× the kinetic energy as the electrical energy invested into its motion.



well, I guess that in a QM Drive, in theory, the electric energy only allows you to kind of access the much bigger energies of the quantum vacuum?
Title: Re: EM Drive Developments
Post by: Star One on 09/12/2014 02:41 pm
Paul March is one of the nicest guys around. I have seen him taking flak and never altering his manners.


GoatGuy at NBF (they made a new article with the things Paul just published above) is now saying it´s obvious the EM Drive (or any other propellantless drive) is a perpetual motion machine because using a simple mission to Saturn in less than a year proves the energy needed to get there is orders of magnitude larger than the electrical energy input.

Quote from: GG
Mission-to-Saturn.
286 days.

Half that is acceleration, and half is deceleration. It only makes sense to keep the thruster "on" the entire trip, to minimize trip time. Half is about 12,000,000 seconds. This is an important number.

Acceleration is 0.0091 m/s² Since V = at and we know both t and a, then V is about 109,000 m/s or 109 km/s. Awesome! I wonder how much kinetic energy it has? Well, that is Ek = ½mV² and our mass is 90,000 kg. OK, easy-peasy. That's then 537,000,000,000,000 joules. about 120 kilotons of TNT as kinetic energy. Impressive!

Now, let's see. 2,000,000 watts for 13,000,000 seconds is what... 26,000,000,000,000 joules. Well then ... it looks like our spacecraft has 20.6× the kinetic energy as the electrical energy invested into its motion.



well, I guess that in a QM Drive, in theory, the electric energy only allows you to kind of access the much bigger energies of the quantum vacuum?

Speaking with a complete ignorance of this guy's past articles, should we take much note of what he says?
Title: Re: EM Drive Developments
Post by: sghill on 09/12/2014 03:06 pm
Paul March is one of the nicest guys around. I have seen him taking flak and never altering his manners.


GoatGuy at NBF (they made a new article with the things Paul just published above) is now saying it´s obvious the EM Drive (or any other propellantless drive) is a perpetual motion machine because using a simple mission to Saturn in less than a year proves the energy needed to get there is orders of magnitude larger than the electrical energy input.

Quote from: GG
Mission-to-Saturn.
286 days.

Half that is acceleration, and half is deceleration. It only makes sense to keep the thruster "on" the entire trip, to minimize trip time. Half is about 12,000,000 seconds. This is an important number.

Acceleration is 0.0091 m/s² Since V = at and we know both t and a, then V is about 109,000 m/s or 109 km/s. Awesome! I wonder how much kinetic energy it has? Well, that is Ek = ½mV² and our mass is 90,000 kg. OK, easy-peasy. That's then 537,000,000,000,000 joules. about 120 kilotons of TNT as kinetic energy. Impressive!

Now, let's see. 2,000,000 watts for 13,000,000 seconds is what... 26,000,000,000,000 joules. Well then ... it looks like our spacecraft has 20.6× the kinetic energy as the electrical energy invested into its motion.



well, I guess that in a QM Drive, in theory, the electric energy only allows you to kind of access the much bigger energies of the quantum vacuum?

Speaking with a complete ignorance of this guy's past articles, should we take much note of what he says?

You should not.  I'm shocked to see him quoted on this thread when we have direct practitioners- including a principle Eagleworks scientist- engaged in open discussion for our benefit.  They could have taken it off-line, but didn't, and that bomb-throwers quotes only serve to shut down the benefits we're getting.
Title: Re: EM Drive Developments
Post by: Rodal on 09/12/2014 03:49 pm
Jose':

I've been involved in testing Dr. Harold Sonny White's Q-Thruster approach to exotic propulsion for seven plus years now, and Dr. James F. Woodward's Mach-Effect (M-E) work for sixteen years. .....
Paul,

Thank you for pointing this out.  I have read with interest several of Dr. Woodward, and Dr. White's papers, including some of your own papers.  It is admirable, in  a sense, to have people willing to pursue research avenues that are not most popular, or commonly accepted.  Concerning Dr. Woodward's, theory, to cut to the chase, as Dr. Woodward himself accepts with a smile in the following presentation (
[ http://www.youtube.com/watch?v=hn8hqX9JBOE#t=2468 ]
where I have on purpose timed it to when the question is asked, otherwise advance to the end of the presentation at 41:08 minutes (2468 sec)) the obvious question to pose to Dr. Woodward is:

If your interpretation of Mach's principle is that inertia is a gravitational reaction from the rest of the Universe (no matter how distant from your center of mass) how come that reaction takes place INSTANTLY ?

In other words, in Dr. Woodward's theory, the propagation of this gravitational reaction responsible for inertia, has INFINITE speed, which is problematic in a Theory of Relativity (where we usually associate gravitational waves to travel at the speed of light).

Dr. Woodward answers with a smile, that "presumably" it is a radiation reaction attributable to Wheeler–Feynman absorber theory.  With his smile and frank facial expression he acknowledges that this is, let's say... problematic?

Because we know that:

A) The Wheeler–Feynman absorber theory assumes that the solutions of the electromagnetic field equations must be invariant under time-reversal symmetry, there is no distinction between past and future.

B)  It therefore assumes that elementary particles are not self-interacting. This is a big drawback of this theory. Indeed, as demonstrated by Hans Bethe, the Lamb shift necessitated a self-energy term to be explained. Feynman and Bethe had an intense discussion over that issue and eventually Feynman himself stated that self-interaction is needed to correctly account for this effect.

C) Wheeler and Feynman conceived of this theory before the Weak Force was understood as it is nowadays.  It is known that the Weak Force implies time-symmetry breaking and gives an arrow of time.  Hence the Weak Force is incompatible with the  Wheeler–Feynman absorber theory, in this sense.

I think that it was wise that you, Dr. White, et.al., decided that <<This paper will not address the physics of the quantum vacuum plasma thruster (QVPT), but instead will describe the recent test campaign>> (Abstract of "Anomalous Thrust Production..." paper).

In that vein, I think it would be best to discuss the experiments without addressing any controversial physical explanation for the time being.

 
Title: Re: EM Drive Developments
Post by: aceshigh on 09/12/2014 04:15 pm
Paul March is one of the nicest guys around. I have seen him taking flak and never altering his manners.


GoatGuy at NBF (they made a new article with the things Paul just published above) is now saying it´s obvious the EM Drive (or any other propellantless drive) is a perpetual motion machine because using a simple mission to Saturn in less than a year proves the energy needed to get there is orders of magnitude larger than the electrical energy input.

Quote from: GG
Mission-to-Saturn.
286 days.

Half that is acceleration, and half is deceleration. It only makes sense to keep the thruster "on" the entire trip, to minimize trip time. Half is about 12,000,000 seconds. This is an important number.

Acceleration is 0.0091 m/s² Since V = at and we know both t and a, then V is about 109,000 m/s or 109 km/s. Awesome! I wonder how much kinetic energy it has? Well, that is Ek = ½mV² and our mass is 90,000 kg. OK, easy-peasy. That's then 537,000,000,000,000 joules. about 120 kilotons of TNT as kinetic energy. Impressive!

Now, let's see. 2,000,000 watts for 13,000,000 seconds is what... 26,000,000,000,000 joules. Well then ... it looks like our spacecraft has 20.6× the kinetic energy as the electrical energy invested into its motion.



well, I guess that in a QM Drive, in theory, the electric energy only allows you to kind of access the much bigger energies of the quantum vacuum?

Speaking with a complete ignorance of this guy's past articles, should we take much note of what he says?

You should not.  I'm shocked to see him quoted on this thread when we have direct practitioners- including a principle Eagleworks scientist- engaged in open discussion for our benefit.  They could have taken it off-line, but didn't, and that bomb-throwers quotes only serve to shut down the benefits we're getting.

Fact is, he keeps throwing his bombs, and at least, I am not knowledgeable enough in this advanced physics subjects to expose flaws in his reasoning. And there are plenty of people who do listen to him.

That's why I quoted him here: expecting people to prove him wrong. In the process, I also learn something.

 
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/12/2014 04:43 pm
Quote from: goatguy
Acceleration is 0.0091 m/s² Since V = at and we know both t and a, then V is about 109,000 m/s or 109 km/s. Awesome! I wonder how much kinetic energy it has? Well, that is Ek = ½mV² and our mass is 90,000 kg. OK, easy-peasy. That's then 537,000,000,000,000 joules. about 120 kilotons of TNT as kinetic energy. Impressive!

Now, let's see. 2,000,000 watts for 13,000,000 seconds is what... 26,000,000,000,000 joules. Well then ... it looks like our spacecraft has 20.6× the kinetic energy as the electrical energy invested into its motion.

Is the math here correct or is it not?

I don't care much about his style of writing, nor do I care so much that someone else is "shocked to see him quoted on this thread".  Is this "easy-peasy" math correct or not?

Intuitively, it does not seem likely at all that a 2MWe spacecraft, which includes payload and the necessary reactor and shielding, could transport 90mT to Saturn's moons in the time suggested.  I believe that the 90mT figure has been completely concocted. 

The 300KWe, 788 day manned fly-by only mission to Phobos/Deimos is also sketchy, at least from this armchair.  Here, the authors believe that somehow a 70 mT stack is assembled in a presumably lunar DRO.  The reader is left to assume that this spacecraft has been appropriately analyzed and suggested.

But hey.

Quote from: Rodal
If your interpretation of Mach's principle is that inertia is a gravitational reaction from the rest of the Universe (no matter how distant from your center of mass) how come that reaction takes place INSTANTLY ?

This question has been asked over and over again, but it has not yet been answered by any of the people who are experimenting with these drives, nor any other physicist studying the problem of inertia, that I can tell.

Just sayin'. 

I'm personally happy to read the back and forth regarding the experimental apparatus.
Title: Re: EM Drive Developments
Post by: Rodal on 09/12/2014 05:22 pm

Quote from: Rodal
If your interpretation of Mach's principle is that inertia is a gravitational reaction from the rest of the Universe (no matter how distant from your center of mass) how come that reaction takes place INSTANTLY ?

This question has been asked over and over again, but it has not yet been answered


Well, yes, it has been answered by Dr. Woodward himself, as I show in the YouTube clip above.  The problem is that Dr. Woodward's explanation relies on the old Wheeler–Feynman absorber theory, which was abandoned by Feynman himself (as I point out above) because of the Lamb shift effect. 

Most importantly, this answer is incompatible with our present knowledge of the Weak Force (as I point out above).   The Weak Force is the only fundamental force that breaks parity-symmetry, and similarly, the only one to break CP-symmetry. 

Has anybody else pointed out the incompatibility of Dr. Woodward's answer (Wheeler–Feynman absorber theory) with the arrow of time shown by the Weak Force?

Bottom line:   I think it would be best to discuss the experiments without addressing any controversial physical explanation for the time being.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/12/2014 05:33 pm
Well, yes, it has been answered...

That would be the case if and only if any answer were acceptable without experimental proof or without requiring the "answer" to reconcile other theoretical incompatabilities.  Savvy?

As I said, I'm personally happy to read the back and forth regarding the experimental apparatus.
Title: Re: EM Drive Developments
Post by: JasonAW3 on 09/12/2014 06:06 pm
Rodal,

     Unless my understanding of what is being implied here is incomplete, which it probably is, it seems to imply that Gravity and Space itself are closely tied together.

     The Albercrombie Drive, for example, uses weird matter to distort Space in a fashion similar to that postulated in Inflation Theory, allowing the craft generating this distortion to ride behind a wave of compacting Space while riding the wave of expanding space behind it.

     What seems to be implied here is that Space can be distorted in the same way using Gravity, if one were able to create a directionalized gravity well.

     So, hypothetically, if one were to create a toroidal magnetic field off sufficent strength to contain a high energy plasma accellerated along the magnetic lines of force, from south pole to north, through the center of the torus and back out again, accellerating the plasma to relativistic velocities, would not such a system also produce an expansion of space at the southern pole of the field while compressing space at the northern pole of the field, in a similar manner to the Albercumbie Drive?  Mind you, by accellerating the Plasma to Relativistic velocities, we amplify it's effective mass (and gravity) and its' effective distortion of space, proportionally.

     Mind you this is both an oversimplification of my thoughts and likely incorrect, but if Gravity is tied to Space in the manner that is seeminlg applied, then in what way is this hypothisys incorrect?

     The only reason I'm posting this here is due to Rodal's previous post concering the instanatious nature of the effect of gravity.  As such, it could be argued that this is an outgrowth of the EM Drive discussion.
Title: Re: EM Drive Developments
Post by: Rodal on 09/12/2014 06:36 pm
Rodal,

         The Albercrombie Drive, for example, uses weird matter to distort Space in a fashion similar to that postulated in Inflation Theory...
Rodal's previous post concering the instanatious nature of the effect of gravity.  ..
Jason,

1) The Alcubierre drive needs a large amount of negative mass (not antimatter, not dark matter, but negative mass) to distort spacetime.  The expansion of spacetime that occurred during Inflation was not due to negative mass.  Problems: A) Where is the negative mass going to come from ? and B) It has been shown that the distortion of spacetime that would enable the Alcubierre drive to travel faster than light would also enable it as a time machine, including a time machine enabling time travel to the past.  There are huge problems with that, not the least being a number of paradoxes.


2) My previous post discussed that Dr. Woodward's answer to the fact that his theory implies instantaneous reaction is incompatible with experimental results: it relies on an old theory of Wheeler and Feynman (late 1940's) that Feynman later abandoned due to the experimental results of the Lamb Shift and most importantly is incompatible with our experimental results for the Weak Force.


____

Once we thoroughly understand the experimental results we can proceed to discuss possible physical interpretations.

Title: Re: EM Drive Developments
Post by: GoatGuy on 09/12/2014 07:28 pm
Hello, folks.  From a poster's recommendation at NextBigFuture, I have come here to participate in this and other fora, If y'all will have it.  Previous posts at NBF (of mine) have been pasted here;  so far, I see little love for the position(s) I've taken. 

To "short circuit" the discussion a bit, I have determined that a VERY simple pair of equations brings into question whether the EM-Thruster or Q-Drive is a perpetual-motion / over-unity energy generator or not.  These:

if [k] is the EM-drive thrust factor, in Newtons-per-Watt (which has been widely used and quoted) then...

V = 1/k ... is the velocity of the Q-device, where the kinetic energy it creates matches the input energy and...
V = 2/k ... is the velocity of a free-floating spacecraft employing the EM-thruster, where the TOTAL energy invested equals the TOTAL imparted kinetic energy of the spacecraft.

These are important equations; I have not so far discerned that there is a contrary-position regarding the over-unity aspect that these equations give users of the EM-drive device(s).  Using the "usual physics" equations for energy, velocity, acceleration, time, mass, force, distance (delta-d) and so on, both of these are really straight forward to prove.  Even if all you do is the empirical math to show applicability. 

In short:

Ek = ½mV²   ... kinetic energy as a function of V
W = Fd   ... work (energy) as function of force and delta-distance (don't know how to get delta typed in)
V = at  ... delta V as function of acceleration and time (assuming constant)
F = ma ... the usual physics, so
a = F/m 

And then some obvious (and algebraically correct) substitutions:

W/t = Fd/t
V = d/t    (change in distance over time, nothing new here...)
W/t = FV
W/t is "power", or P, so
P = FV = maV  (again, nothing unusual)

When F = k·Pin   (k is newtons per watt, Pin is watts) then substituting...

P = k·Pin·V ... now just setting the "critical over-unity point" where both P and Pin are the same (P = Pin) then:
P = k·P·V
1 = k·V
V = 1/k  by rearrangement

That one was easy, agreed?  And correct, classical Newtonian physics.  The second case is a bit harder to prove, but still within reach of ordinary algebra:

Ek = ½mV²   ... kinetic energy as a function of V, again.
V = at ... again, now substitute
Ek = ½ma²t²  and remembering that [F = ma]...
Ek = F²t²/(2m)

Since the spacecraft/thruster will consume Ein = Pin·t  (power times time), then setting Ein = Ek (total energy in, to total kinetic energy of free-flying craft), we get:

Ek == Ein
Ek = Pin·t
Pin·t = F²t²/(2m), and solving for t:
t = 2·Pin·m/F², which is the time at which the kinetic energy of the craft matches the total input energy, and
V = at
V = a·( 2·Pin·m/F² )   (and recalling F = k·Pin AND a = F/m, and a = k·Pin/m...)
V = a·( 2·Pin·m/(k²Pin²) )
V = ( k·Pin/m ) · ( 2·Pin·m/(k²Pin²) ), and with algebraic rearrangement
V = ( 2·k·Pin²·m ) / ( m·k²Pin² ), then cancelling things on top and bottom:
V = 2 / k

Where this then is the velocity of the craft considered in its OWN reference frame, as attaining an amount of delta-V, which equates to kinetic energy, that is EQUAL to the amount of electrical power pumped into the thruster.  ANY additional velocity then gives the craft, in its own reference frame, MORE kinetic energy than has been invested into it by way of the thruster. 

At (V > 1/k), it is a free energy device.

Thanks for the consideration.  I hope there will be a reply that answers this fundamental flaw.

GoatGuy
Title: Re: EM Drive Developments
Post by: Rodal on 09/12/2014 07:36 pm
Paul March,

OK, Let's try to discuss the experimental set-up.  From one of your previous posts, I understand that the inverted pendulum arm is made of this: http://www.amazon.com/Faztek-15QE1515UL-Aluminum-T-Slotted-Extrusion/dp/B008MQA11C .

Going to the company's website:  http://www.faztek.net/technical.html, I understand that the "Faztek 15QE1515UL Aluminum 6063-16 T-Slotted Ultra Light Extrusion with Clear Anodize Finish, 1-1/2" Width x 1-1/2" Height" you use for the inverted pendulum arm has the following Moments of Inertia (in bending):

Ix = Iy = 0.1802 in^4

and the following modulus of elasticity:

E = 10^6 psi

I also understand from your prior post that this moment arm is restrained from rotations around the X and Y (horizontal) axes at the bottom support by two Riverhawk C-flex torsion bearings, and << the center of the two C-flex bearing blocks is 2.38" above and below the centerline of the 24.00" long by 1.50" square aluminum pendulum arm.  The long end of the pendulum arm is 15.5" from the torque pendulum's center of rotation, which makes the other short-end of the pendulum arm 8.5">>.

What I need is the arm distance between the bottom support and the supported platform with weight. If I interpreted correctly what you wrote, this length "l" is:

l = 15.5" - 2.38"=13.12 inches =0.33325 meters

I needed the elastic spring constant of the pendulum arm (in swinging motion).  I understand that the number you provide << The Riverhawk C-flex torsion bearing's spring constant is a nominal 0.007 in-Lb/deg>> must be for torsion around the vertical "Z" axis normal to the horizontal plane, because this spring constant is extremely low.

So, my interpretation is that we therefore have to calculate the (bending) spring constant of the pendulum arm (in swinging motion).  Interpreting the two Riverhawk C-flex torsion bearings constraints as a cantilevered support for the pendulum arm, and using the suggested beam deflection formula in the faztek website for a cantilevered beam acted by a force at the free end:

MaximumDeflection = delta = F * (l^3) / (3 E I )

The (bending) spring constant of the pendulum arm (in swinging motion) for rotation around the X and Y horizontal axes is:

k = F/delta = (3 E I ) / (l^3) = 3 * (10^6 lbf/in^2) * (0.1802 in^4) /(( 13.12 in)^3) = 2393.726 lbf/in
k =( 2393.726 lbf/in) *( 4.44822162 N/lbf) / (0.0254 in/m) = 4.192*10^5 N/m

Is my interpretation correct ?
Title: Re: EM Drive Developments
Post by: Rodal on 09/12/2014 07:52 pm
@ Paul March,

We also needed the total supported weight (of all the supported equipment, the drive AND the platform on top of the pendulum arm).  I understand that this is 25 lbf (although I wonder whether you included the weight of the supporting platform resting on the pendulum arm as well ?)

Taking this as the total supported mass:

M = 25 lb = 25 lb * (0.453592 kg/lb) = 11.3398 kg

We get a ratio of (swinging motion) spring constant to mass of:

k/M =( 4.192*10^5 kg*(m/s^2)/m)/11.3398 kg = 3.6968*10^4 1/(s^2)

and the gravity term is:

g/l = (9.80665 m/(s^2))/(0.33325 m) = 29.4273 1/(s^2)

So, the stiffness-to-mass term is 1256 times greater than the gravity term, and the frequency (in swinging motion around the X and Y horizontal axes) is:

f = (1/(2 Pi))Sqrt[3.6968*10^4 1/(s^2) - 29.4273 1/(s^2)] = 30.59 Hertz

[I presume that this is an upper bound for the frequency because it assumes that the bearings are providing a cantilevered condition with no swinging flexibility around X an Y, and it presumes that 25 lbf is the total weight supported on top of the pendulum arm, including the platform]
Title: Re: EM Drive Developments
Post by: Rodal on 09/12/2014 08:26 pm
Hello, folks.  From a poster's recommendation at NextBigFuture, I have come here to participate in this ....
Thanks for the consideration.
GoatGuy

@GoatGuy,

What is your physical explanation for the experimental measurements (of at least 6 different drives) at NASA Eagleworks?, including

A)  dependence on the Teflon dielectric resonator (without the dielectric resonator they measured zero thrust) and

B) that when they turned the drive (by 180 degrees rotation around the Z vertical axis), with the dielectric resonator to the "left" instead of to the "right", they got a similar numerical thrust result, but now directed to the opposite direction as compared to the previous orientation (showing a thrust measurement vector dependent on physical orientation of the drive) ?
Title: Re: EM Drive Developments
Post by: frobnicat on 09/12/2014 08:48 pm
Hello, folks.  From a poster's recommendation at NextBigFuture, I have come here to participate in this and other fora, If y'all will have it.  Previous posts at NBF (of mine) have been pasted here;  so far, I see little love for the position(s) I've taken. 

Speaking for myself as a relatively newcomer, welcome onboard.

Quote
.../...
At that point, it is a free energy device.

Thanks for the consideration.  I hope there will be a reply that answers this fundamental flaw.

GoatGuy

Well, I did post similar argument : http://forum.nasaspaceflight.com/index.php?topic=29276.msg1240286#msg1240286 (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1240286#msg1240286)
I don't remember counter arguments : I guess no one can seriously object that a reactionless drive with such Thrust/Power ratio is indeed either a free energy device, or pumping energy from somewhere (see below).
But this very serious and immediate practical consequence seems to be less excitingly investigated than (beyond my understanding) theoretical inconsistencies of the aspects of Machian inertia for critics, and the possibilities of delivering grand pianos to Saturn moons for enthusiasts.

A few caveats :

Your calculations are Newtonian mechanics, when approaching c speeds or Thrust/Power ratios below 1/c its no longer valid, and indeed we have the photon rocket as an example of a "reactionless" drive that is not a free energy device. The claimed thrust/power = k ratio is more than 2 orders of magnitude above that, so it's ok to go Newtonian as a good approximation, also it should be acknowledged and stressed that as soon as a purported k factor is even so slightly better (higher) than 1/c of the photon rocket, then there is energy conservation breaking for some inertial reference frame (also maybe not practical to exploit).

Quibbling : "velocity of the craft considered in its OWN reference frame" could be misread as "the frame of its acquired speed now" (absurd as it would be 0 by definition, but yet). Could we say "in the inertial reference frame of its departure" or something like that (English not my native tongue) ?

Ok so we are breaking energy conservation, great : Noether's theorem show this implies reality not to be time invariant. Hard to swallow much much below cosmological timescales.

Ok so energy is conserved but the acquired energy is pumped from vacuum, not free energy but rel cheap energy, great : quoting myself  "tap into vacuum zero-point energy, which would no longer be zero-point... My guess is that all this virtual agitation down there is like a thermal bath and nothing useful (in terms of net work) can come out of it (second principle...) but please someone qualified help." In context :
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243932#msg1243932 (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243932#msg1243932)

Penultimate point : if the k factor somehow decays with acquired speed (relative to start frame of reference) this could mitigate the free energy aspect. But then the mission profiles are not the same... and it's really difficult to see what would make the system "remember" this particular initial reference frame, and it doesn't prevent the drive to be a free energy generator relative to some well chosen arbitrary inertial reference frame.

Last point : the k=0.4 N/kW figure used for the mission profiles implies possible breakeven starting at speeds of 1/k=2.5km/s relative to a fixed frame. That is if you mount the drive on a rotor, and re-inject the energy of the shaft into the drive, you have not only a theoretical but an almost practical free (or rather cheap) energy generator : the rim of fastest wheels for energy storage is around 2km/s. (Take into account the efficiency of the closed loop, if 0.5 then turn at 5km/s tangential speed, mechanically harder to get at but still conceivable without unobtainium). I'd like to see the experiment done on a freely rotating arm, in an otherwise rotationally symmetric setting around the axis.

Title: Re: EM Drive Developments
Post by: francesco nicoli on 09/12/2014 09:16 pm
Anyway, great to have GoatGuy on this forum. NBF is an interesting platform for discussion but faaar less professional than here on many subjects; GoatGuy is by far the more informed discussant there and will add lot of quality here as well. Welcome!
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/12/2014 09:21 pm
What is your physical explanation for the experimental measurements (of at least 6 different drives) at NASA Eagleworks?, including

A)  dependence on the Teflon dielectric resonator (without the dielectric resonator they measured zero thrust) and

B) that when they turned the drive (by 180 degrees rotation around the Z vertical axis), with the dielectric resonator to the "left" instead of to the "right", they got a similar numerical thrust result, but now directed to the opposite direction as compared to the previous orientation (showing a thrust measurement vector dependent on physical orientation of the drive) ?

I'm sorry, how does that address [V > 1/k case, and V > 2/k cases], which was the point of my posting?   I am not questioning whether something was measured.  What I am questioning is whether such a finding leads immediately to declaring the device a free energy device after some amount of power is invested in its motion in space.  That's, all.

GoatGuy

EDIT / postscript:  special alert - I'm aware that when 'k' is equal or less than 1/299,792,000 newtons per watt, conservation of energy is preserved, as that particular number is reserved for perfect radiators of electromagnetic energy.  They manage not to break the conservation of energy criterion because they would have to "burn up" a lot of matter (say, optimally, matter-antimatter at perfect efficiency!) ... and the amount of speed/thrust then becomes almost exactly what you'd expect for a rocket that just as efficiently exhausted real reaction mass.   

GoatGuy
Title: Re: EM Drive Developments
Post by: Rodal on 09/12/2014 09:23 pm

Virtual particles of the vacuum on the other hand don't appear to define a frame of reference, though they might define an "inertial reference" (tm) : Casimir effect for instance don't show different behaviour on different inertial frames (Lorentz invariant, no reference of what would be an absolute 0 speed relative to vacuum) while dynamical Casimir effect allows to measure acceleration in absolute terms (can tell an absolute 0 acceleration relative to it)....


We don't really need to go there either:top physicists nowadays do NOT explain the Casimir effect in terms of "negative mass" or "negative energy" but as a van der Waal (charge) force just as in the Lamb shift.  Pauli, Feynman,  de Witt were known to express their dissatisfaction with the quantum vacuum explanation. Swchinger found it so distasteful that he came up with his own successful explanation.  To me the failure (in his own attempt) by Casimir himself to explain the fine structure constant  in terms of the quantum vacuum should be telling enough.  Ditto for his failure to explain and predict even the sign of the Casimir force for different shapes (instead of plates).


Why don't we discuss the experimental results and physical explanations for them instead of tearing up controversial theories?

ADDED: To me tearing up a controversial theory is like Don Quixote charging against the windmills.  Addressing and explaining the experimental results instead is analogous to physicists explaining quantum mechanics experimental results in the early 20th century to come up with the theory of Quantum Mechanics: the most successful theory to explain nature, yet it was thrusted on us by experimental results so strange that caused Bohr to say <<If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet.>> and Feynman to say <<I think I can safely say that nobody understands quantum mechanics.>>



Title: Re: EM Drive Developments
Post by: Rodal on 09/12/2014 09:31 pm
I'd like to see some qualified explanations with Feynman diagrams showing how it's impossible to push on virtual particles (unless they are made real at equivalent energy/mass cost).

I think that Matt Strassler (currently a visiting scholar at Harvard University) does an excellent job here:

 http://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/



<<The term “virtual particle” is an endlessly confusing and confused subject for the layperson, and even for the non-expert scientist. I have read many books for laypeople (yes, I was a layperson once myself, and I remember, at the age of 16, reading about this stuff) and all of them talk about virtual particles and not one of them has ever made any sense to me. So I am going to try a different approach in explaining it to you.

The best way to approach this concept, I believe, is to forget you ever saw the word “particle” in the term. A virtual particle is not a particle at all. It refers precisely to a disturbance in a field that is not a particle. A particle is a nice, regular ripple in a field, one that can travel smoothly and effortlessly through space, like a clear tone of a bell moving through the air.  A “virtual particle”, generally, is a disturbance in a field that will never be found on its own, but instead is something that is caused by the presence of other particles, often of other fields.>>

ADDED (Feynman diagrams):

<<The language physicists use in describing this is the following: “The electron can turn into a virtual photon and a virtual electron, which then turn back into a real electron.” And they draw a Feynman diagram that looks like Figure 4. But what they really mean is what I have just described in the previous paragraph. The Feynman diagram is actually a calculational tool, not a picture of the physical phenomenon; if you want to calculate how big this effect is, you take that diagram , translate it into a mathematical expression according to Feynman’s rules, set to work for a little while with some paper and pen, and soon obtain the answer.>>

<<This is shown in Figure 7, and the corresponding Feynman diagram is shown in Figure 8.  This goes on and on, with a ripple in any field disturbing, to a greater or lesser degree, all of the fields with which it directly or even indirectly has an interaction.

Fig. 8: The Feynman diagram needed to calculate the process shown in Figure 7.
So we learn that particles are just not simple objects, and although I often naively describe them as simple ripples in a single field, that’s not exactly true.  Only in a world with no forces — with no interactions among particles at all — are particles merely ripples in a single field!  Sometimes these complications don’t matter, and we can ignore them.   But sometimes these complications are central, so we always have to remember they are there.>>
Title: Re: EM Drive Developments
Post by: aero on 09/12/2014 09:38 pm
@GoatGuy, frobnicat,

Your arguments illustrate that the operational principles of the EM drive satisfy Clark's third law - they are, "indistinguishable from magic". Your arguments do not advance our understanding of those principles. Others have taken the risk and dared to postulate principles but I know of none that are accepted. Go ahead, take the risk, postulate physics sufficiently advanced as to cast light on the difference between operation of the EM drive and magic.
Title: Re: EM Drive Developments
Post by: 93143 on 09/12/2014 09:55 pm
I hope there will be a reply that answers this fundamental flaw.

A Mach-effect device is supposed to be interacting with the distant universe; that's inherent in the theoretical derivation.  (If I understand correctly, the Wheeler-Feynman stuff doesn't have to be assumed to get this result; Sciama's model and Woodward's application of it just have to do with local gravitational potential.)

Basically, your energy balance isn't complete until you've accounted for the device's interaction with the rest of the matter in its Hubble sphere, whatever form that interaction takes.  In other words, you're drawing the box too small.

Furthermore, without something to push on, you aren't just violating conservation of energy; you're violating conservation of momentum too.  The equations of mechanics don't work that way, and you can see this if you consider the fact that the kinetic "energy" of a single body is frame-dependent - only a momentum-conserving system exhibits Galilean invariance of kinetic energy changes due to interactions.  So really, using Newtonian mechanics to treat a Mach-effect thruster in isolation is nonsensical from the start.

...

I'm not sure how the Q-thruster is supposed to conserve energy; it looks like a ZPE device to me, but then I haven't studied it much...

Regarding the EM-Drive, I thought it was pretty well established that Shawyer's explanation implied a violation of conservation of momentum, and that thus if the drive worked it would be for some other reason.  Again, though, I haven't studied it much...
Title: Re: EM Drive Developments
Post by: frobnicat on 09/12/2014 10:57 pm
@dr Rodal,
Frankly I'm not qualified to argue about details of vacuum, so maybe I should rather shut my mouth about that  :P  But I will definitely read the link to Matt Srassler when time permits, thanks.

Actually my point in this former post of mine (from which I was excerpting) was that, as far as I know (which is not much in quantum physics, a little more in phenomenological astrophysics) vacuum is Lorentz invariant, and all attempts at putting intrinsic frames of reference of space/vacuum or aether back on the table failed experimentally so far (though there are theories...). It's important as it makes inescapable the "free energy" consequence of "pushing on the vacuum" : breaking momentum conservation (or exchanging net momentum with vacuum) is breaking energy conservation (or exchanging energy with vacuum), one can't go without the other, regardless of possible theories beyond very very well verified quantitative predictions of Newtonian mechanics at speeds<<c, please correct me if I'm wrong on that.

If there is indeed favorite intrinsic frames of reference or aether then yes, I see how it would be possible to push on that with much better efficiencies than with reaction propulsion, without breaking energy conservation (or pumping some from vacuum) but then the k factor would decrease as your absolute speed relative to this aether increase, and mission profiles are not the same. Also some "aether wind" effect should be observed in conjunction with earth rotation (orientation of the experiment relative to the stars). Unless the aether is anchored to nearest massive body (back to old aether problems...).

The point is, this free energy consequence is seldom put forward by, let's say, enthusiasts of space drives. As if maybe free (or cheap) momentum were deemed "more acceptable" than free (or cheap) energy that is so much connoted crackpot science. If it works at all for thrust and spaceships then so well, but please proponents, don't put the free energy generators under the rug as it is a consequence. It sounds sarcastic but I'm not, I'm not against the experiments or the experimenters, clearly I'm very sceptic about a "real" (useful) effect here but ready to be convinced when/if results can be reproduced by sceptics. It needs the sceptics to be convinced that it's worth to try reproduce the experiments. But there is no point in trying to hide the "free energy" consequences.

@aero
yes when Michelson and Morley experiment show the breaking of the rule of speed additivity, this is a result indistinguishable from magic. I'm not qualified and gifted enough to advance the principles at work, should the EMthrust prove to be real. Then maybe the k factor would be observed to decrease with speed in such a way not to break energy conservation or pump it from vacuum, but then don't expect the same mission profiles for spaceships. Or maybe the k factor is indeed free from v effects and, in all logic, we have free energy, even real possible free energy devices tomorrow if k approaches 1N/kW as hoped by proponents.
But we are not at the point where the effect is accepted so I feel no urge to fill the theoretical gap.
Again, I'm not against dedicated minds taking the risk, and quite supportive of inquiring the possible effect, if not by sending a million dollar probe at first, at least by providing means to try to reproduce it and investigate it phenomenologically (magnitude dependence on energy densities ? dependence on orientation relative to stars ? dependence on velocity/acceleration when freely moving ? ...) then we can discuss the theories on firmer ground.
But (again) I'm against a "what if it works" scenario that wont go to all the inescapable consequences, when the consequences are on firm ground that couldn't possibly be overtaken by the hypothesis (I don't see how the possibility to push on vacuum could change the observed fact that Ec=1/2mv² as far as practical mundane useful kinetic energy is concerned, how ?) : this is too reminiscent of bad SciFi. Fantasy is another realm but wont take us to the stars. Why wouldn't you want a nice free energy generator to power up your free momentum drive ?
Title: Re: EM Drive Developments
Post by: frobnicat on 09/12/2014 11:28 pm
So really, using Newtonian mechanics to treat a Mach-effect thruster in isolation is nonsensical from the start.

Using Newtonian mechanics to treat the local useful consequences of such a thruster in not nonsensical, the fact that the energy balance would be conserved instantly within the cosmological horizon can be satisfactory for theorists, but as far as engineering goes this is indistinguishable from free energy and doesn't prevent to make accurate mission profiles with Newtonian mechanics or making real unlimited energy generators, assuming the effect is real, regardless of theories. Again, if the effect is real, then very well, we have good spaceships, and good energy generators, free energy, for all practical purpose.
Sorry to put forward my take on this GoatGuy, this was addressed to you.
 
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 12:21 am
....

@frobnicat, yes, I agree, as I posted before there are substantial problems with the proposed "out of the mainstream" explanations.   So, what I propose is that instead we discuss

A) my preference at the moment: alternative explanations for the experimental measurements, or if, you prefer,

B) we discuss in detail Dr. White's equations .   We could discuss the fact that, in the end, Dr. White does NOT actually use in his calculations the density of the (zero point) quantum vacuum, but instead he uses what he calls a "local quantum vacuum density" that is several orders of magnitude larger than the density of the zero-point quantum vacuum.  Those  in this forum that defend or battle the "zero point quantum vacuum" explanation may be defending or battling an un-existing explanation . 

So, how about discussing Dr. White's justification for the much higher value he uses for the "local density of the quantum vacuum" and what this implies ...?
Title: Re: EM Drive Developments
Post by: 93143 on 09/13/2014 12:39 am
Again, if the effect is real, then very well, we have good spaceships, and good energy generators, free energy, for all practical purpose.

If the operation of the device is independent of its velocity (Woodward's equation sure looks like it is), and the efficiency in N/W gets high enough for practical application in an energy-generating device, yes, you could do that.  I have myself maintained in the past that this sort of technology could revolutionize far more than just space travel.

I have a half-formed idea involving the relativistic Doppler effect that I think might explain the apparent velocity independence of the M-E drive principle, in such a way that a "free-energy" device like what you're describing would essentially be a heat engine powered by the Big Bang.  But maybe I should shut up about it until I've had time to get into the theory a little more...

as I posted before there are substantial problems with the proposed "out of the mainstream" explanations.

Regarding the Wheeler-Feynman idea specifically, I'm not sure what you've stated constitutes an ironclad case against it.  For one thing, it seems to me that gravity and the weak force are two different things, and since we don't even have a theory that unifies them it strikes me as premature to claim that time-asymmetry in one necessarily implies time-asymmetry in the other (though I may be misunderstanding something).  For another, according to the Wikipedia page (no, I'm not an expert; can you tell?) on W-F absorber theory, there have been calculations that recover the Lamb shift without requiring self-energy.

I'm an engineer, not a physicist, but this sounds like an open question to me.
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 12:50 am


as I posted before there are substantial problems with the proposed "out of the mainstream" explanations.

Regarding the Wheeler-Feynman idea specifically, I'm not sure what you've stated constitutes an ironclad case against it. 

Well, then you are stating your own theory, not Dr. Woodward's, because as per the video I posted, Dr. Woodward answered that his theory requires either the Wheeler-Feynman absorber theory (or even more unsupported by experiments, a constrained theory changing the type of differential equations (elliptic instead of hyperbolic  !!!!!)).

Also, you seem to be stating your own theory, not Dr. Woodward's, concerning the incompatibility with the Weak Force, because Dr. Woodward's also stated in that video that his interpretation for the inertia effect is a radiation interaction, and we know that the Weak Force interaction is paramount in a radiation interaction.

But a theory of Physics is more than just words we can discuss in this thread, you would have to replace Dr.  Woodward's theory with your own set of consistent equations...
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 01:03 am
it strikes me as premature to claim that time-asymmetry in one necessarily implies time-asymmetry in the other (though I may be misunderstanding something).

It is not premature to claim that there is only one time and not two times.  There is not one time for gravitation and another time for the Weak Force, there is only one time in Dr. Woodward's theory.  When Dr. Woodward explains his inertia effect as a radiation interaction he is using the same time that he uses for gravitation in his General Relativity equations.


For another, according to the Wikipedia page (no, I'm not an expert; can you tell?) on W-F absorber theory, there have been calculations that recover the Lamb shift without requiring self-energy.

Yes, as you know anybody (even without being registered in Wikipedia) can anonymously write and change things in Wikipedia.  The alternative calculations that recover the Lamb Shift without requiring self-energy are not generally accepted, and have problems of their own.  I wrote a lot of the Wikipedia article on the Beta Distribution (  http://en.wikipedia.org/wiki/Beta_distribution ) (you can see my name associated with most graphs and in the Talk Page), I know what a headache is to deal with this issue by Wikipedia managers, who try to do their best  :)
Title: Re: EM Drive Developments
Post by: 93143 on 09/13/2014 01:05 am
Dr. Woodward's also stated in that video that his interpretation for the inertia effect is a radiation interaction, and we know that the Weak Force interaction is paramount in a radiation interaction.

I'm sorry; you've lost me.  What has the weak force got to do with the propagation of changes in a gravity field?
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 01:08 am
Dr. Woodward's also stated in that video that his interpretation for the inertia effect is a radiation interaction, and we know that the Weak Force interaction is paramount in a radiation interaction.

I'm sorry; you've lost me.  What has the weak force got to do with the propagation of changes in a gravity field?

Have you actually listened to the video I posted of Dr. Woodward?  I'm quoting what Dr. Woodward stated.  Perhaps you should state that "Dr. Woodward lost you". Dr. Woodward himself says that it is radiation interaction.
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 01:16 am
Dr . Woodward answers the question with the following statement:

it is a radiation reaction interaction, presumably, that involves the Wheeler-Feynman ...
Title: Re: EM Drive Developments
Post by: 93143 on 09/13/2014 01:21 am
No, it's the part where the weak force is involved that confuses me.  I have Woodward's book; he's talking about gravity waves.  Something about quadrupole radiation with the rest of the universe as part of the system.  And as far as I know there is no universally accepted theory that couples gravity with any of the other forces.

Perhaps you could explain a little, rather than just assuming I already know all this and am being deliberately obtuse?
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 01:33 am
At the time that Wheeler and Feynman conceived their theory (late 1940's) not much was known about the Weak Force.  We are here 70 years later, with all kinds of experimental results including the Weak Force's arrow of time, and its role in radiation.

Yes, you are correct that we don't have a Unified theory of Gravitation and Quantum Gravity.  And yes, Dr. Woodward can have a theory that uses Wheeler Feynman absorber theory (although Feynman himself abandoned that theory) and ignore the Weak Force if he likes.    I would prefer to consider present theories that are compatible with present experimental knowledge, including the Weak Force, and that explain known phenomena in a more unified way than it was possible in the 1940's.
Title: Re: EM Drive Developments
Post by: 93143 on 09/13/2014 01:35 am
Does the weak force have anything to do with gravity waves specifically?  Because that's what Woodward is talking about.  He's not talking about the Wheeler-Feynman theory in electrodynamics; he's repurposing the concept for gravity.
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 01:46 am
Sorry, I don't understand this statement <<Does the weak force have anything to do with gravity waves specifically?  Because that's what Woodward is talking about.  He's not talking about the Wheeler-Feynman theory in electrodynamics; he's repurposing the concept for gravity.>>.

Please explain how this works: does Dr. Woodward end up with gravity waves that travel at infinite speed?
Title: Re: EM Drive Developments
Post by: 93143 on 09/13/2014 02:01 am
Of course not.  The whole point of the advanced/retarded wave concept in W-F is that you can get instantaneous action at a distance without breaking causality; no momentum or energy or information need travel faster than c.
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 02:07 am
 <<the advanced/retarded wave concept in W-F is that you can get instantaneous action at a distance without breaking causality>>

We disagree:

instantaneous action at a distance means an infinite speed

and yes, Wheeler-Feynman absorber theory is well-known to break causality.  Both Wheeler and Feynman admitted this.  Feynman wrote about this in at least one of his books. 

Now, 70 years later, after Feynman dropped the W-F theory long ago, we have at least 3 arrows of time:

1) The cosmological arrow of time: from the order of the Big Bang, through Inflation through Dark Energy accelerating expansion (this last one unknown at the time of W-F).

2) The 2nd law of Thermodynamics arrow of time in the macro world we inhabit.

3) The Weak Force arrow of time at the Quantum Mechanics level (not well understood at the time of W-F theory).
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 02:21 am
<< I have Woodward's book; he's talking about gravity waves.  Something about quadrupole radiation with the rest of the universe as part of the system.>>

I don't have any of Dr. Woodward's books.   I only read some of his papers.  My statement concerning radiation was entirely based on his video.  Thank you for explaining that he meant quadrupole radiation. Therefore what he meant was the radiation of the gravity waves, and he didn't mean anything to do with actual particle radiation  --therefore nothing to with the Weak Force in that sense, I agree.

Still I make my argument regarding the three arrows of time, and what we have learnt during the last 70 years since W-F, Dark-Energy accelerating expansion involvement for the Cosmological arrow of time and the Weak Force for the Quantum Mechanics arrow of time.
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 02:32 am
You can disregard the Quantum Mechanics (Weak Force) arrow of time, and the 2nd law of Thermodynamics arrow of time (both at your own peril), concerning a theory of inertia and gravitation.  I would rather not disregard them. 

But I don't understand how you or Dr. Woodward can disregard the Cosmological arrow of time.

And it is strange to consider a General Relativity theory where one divorces completely from the Quantum Mechanics arrow of time (the Weak Force), but postulates that gravitational waves travel effectively with infinite speed, as with "action at a distance" (a concept only known in Quantum Mechanics entanglement).
Title: Re: EM Drive Developments
Post by: cuddihy on 09/13/2014 02:33 am
Goat Guy: no page of calculations are required for a prima facie rejection of the premise.

Any scheme that requires mass-energy input to the object to equal the change in the object(s) mass-energy is by definition a normal rocket, not 'propellantless'.

'Propellantless', whether Woodward or EM or whatever *assumes* less mass-energy required to be input to the rocket than the rocket gains during this process. Period.
So argue the premise is rediculous all you want. But the calculation of difference between input and change doesn't add anything.
Title: Re: EM Drive Developments
Post by: 93143 on 09/13/2014 02:41 am
instantaneous action at a distance means an infinite speed

Are you sure you know what Wheeler-Feynman absorber theory actually says?  'Cause I was pretty sure I understood the gist of it, and what you've said here is wrong according to my understanding.  Nothing in the theory travels faster than c, and that remains true in Woodward's gravinertial version.

Quote
Still I make my argument regarding the three arrows of time

I don't find this a strong argument.  The only one of those three that seems potentially relevant is the cosmological one, but it's a bit circular (unless I've misunderstood it) and doesn't seem to bear on the nature of fundamental physical interactions.

Basically, just because some things are time-asymmetric doesn't mean all things are.  You yourself stated that the weak force is the only one of the four forces that seems to be, which as far as I can tell leaves the door pretty wide open for what Woodward is describing...

I'm not saying he's right.  But I don't think you've made much of a case for saying he must necessarily be wrong.
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 02:52 am
instantaneous action at a distance means an infinite speed

Are you sure you know what Wheeler-Feynman absorber theory actually says?  'Cause I was pretty sure I understood the gist of it, and what you've said here is wrong according to my understanding.  Nothing in the theory travels faster than c, and that remains true in Woodward's gravinertial version.


The statement is absolutely correct on the first count.  Instantaneous action at a distance means an INFINITE speed, in any theory, not just W-F theory.  The only proviso you could make would be to involve Quantum Mechanics here all of a sudden and claim that instantaneous is restricted to the Planck time  :)

Title: Re: EM Drive Developments
Post by: 93143 on 09/13/2014 03:00 am
I was using the phrase in the context of W-F theory, where (if I'm not greatly mistaken) it means something other than what it seems to mean on its face.

As far as I can tell, the idea is basically that a particle that does something feels the reaction from other particles instantaneously, but the other particles actually react at time t0+r/c.  This is where the reversed-time waves come in - the initial action resulted in a normal retarded wave, which propagated at c, and the other particles on receiving this wave produced an advanced wave in response which traveled back in time to converge at the point of initial action.

In the context of M-E, it would mean that the thruster feels the effect of the distant matter reacting to its operation instantaneously, but the distant matter doesn't actually react for billions of years.
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 03:03 am
I have not seen Dr. Woodward's "re-purposing" of W-F for gravitational waves.  If Dr. Woodward's formulation results in a causal gravitational wave, then it canNOT be "instantaneous action at a distance".  But that is NOT what Dr. Woodward answered in the video. 

Do you claim that Dr. Woodward misspoke in the video? Or that Dr. Woodward meant that instantaneous action is not an infinite speed? How long a period of time is instantaneous according to Dr. Woodward?
Title: Re: EM Drive Developments
Post by: aceshigh on 09/13/2014 03:05 am
I think we are only missing Dr Woodward and Dr White themselves in this topic right now :D
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 03:06 am
<<the thruster feels the effect of the distant matter reacting to its operation instantaneously>>

Well instantaneous means an Infinite speed.  How does the thruster "feel" the effect of distant matter instantaneously?  Does the thruster have a special means of feeling that is traveling through wormholes and not through spacetime?
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 03:09 am
Does the thruster have a special means of feeling distant matter that is traveling through ANOTHER DIMENSION, one of the infinitesimally small extra dimensions of string theory and it is wormholing through that extra dimension and hence avoiding normal spacetime?
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 03:11 am
Actually, one of Dr. White's papers invoked a string theory manifold with 1 extra dimension (3+1), having 4 space dimensions...But I haven't seen anything by Dr. Woodward invoking extra dimensions...
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 03:16 am
The "Chung-Freese" metric with 3+1 dimensions.... NO experimental evidence whatsoever for that.  But you are free to consider it if you like.  I would rather consider a Cosmological arrow of time myself, I think that there is much more evidence for that...
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 03:22 am
And to be fair to Dr. White, he only invoked the Chung-Freese 3+1 metric to see how far he could push the warp field drive concept.  I don't fault him for that, it was an interesting exercise. 

Dr. White did not invoke the Chung-Freese 3+1 to justify action at a distance. 
Title: Re: EM Drive Developments
Post by: 93143 on 09/13/2014 03:36 am
Perhaps you should slow down and read my whole post a little more carefully.

There is no instantaneous communication.  There is an instantaneous reaction that results from communication forward and then backward in time, at c.  The distant matter does not feel the interaction at the same time the thruster does.

[NB for anyone reading this:  this is not the result Woodward derived.  It is an explanation he brought in afterward to make sense of the implications of his result, and does not have to be accepted in order to take his experimentation or even his Mach-effect equation seriously.]
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 03:45 am
OK, this was an enjoyable discussion.

You admit that <<There is an instantaneous reaction that results from communication forward and then backward in time>>

There are two things here that bothered me greatly:  1) instantaneous reaction and 2) communication backwards in time.

I would rather consider other alternatives, which respect the arrow of time, and where there is no instantaneous reaction.  I have much more of a problem with  " communication backwards in time" than with the information traveling through an extra dimension in the Chung-Freese metric.   You know, there are string theories (one of them proposed by Professor Randall at Harvard (http://en.wikipedia.org/wiki/Randall%E2%80%93Sundrum_model )) that support the idea of gravitation being the only force that escapes our 3-D Universe -that's why gravity is so weak compared to the other forces-. 

I think that Dr. Woodward also is not 100% comfortable: he smiled and said "that's the obvious question to ask" and he said "presumably....".   Presumably means that he is not 100% comfortable with this.   And he didn't give only one alternative, he gave two:  the Wheeler-Freeman was one, and constraining the equation to become elliptic instead of hyperbolic was another one.  To me it looks like he was not very certain of what is the answer...

Let's continue this later  :)
Title: Re: EM Drive Developments
Post by: birchoff on 09/13/2014 01:04 pm
John (Fornaro) and Paul (March),

The experimental results and possible explanations are not trivial, addressing and studying them will take patience and time.  There are subtle issues involved because of the extremely small forces being measured. 

There is no hurry. 

I think that we have a great line of communications !.  Let's keep it going. :D


To Infinity and Beyond (or to wherever we can get with the propulsion we have)

Jose' Rodal

Look up at the stars. Try to make sense of what you see. Be curious.

Jose':

I've been involved in testing Dr. Harold Sonny White's Q-Thruster approach to exotic propulsion for seven plus years now, and Dr. James F. Woodward's Mach-Effect (M-E) work for sixteen years.  (I started down this road in March of 1998 while working for Lockheed-Martin at JSC working as an electrical engineer on the NASA Space Shuttle program.)  I summarize my M-E AKA Woodward Effect research in three STAIF papers published in 2004, 2006 and 2007.  I know Dr. Woodward's body of M-E work extensively having been to his lab at CSUF a number of times now, and IMO Woodward has been seeing real forces in his M-E Thruster (MET) experiments for years. 

These latest experimental results on the Q-thruster is just trying to take Jim's work one step further by attempting to quantize the gravitational field in a manner consistent with Quantum Mechanics (QM), Plasma Physics and General Relativity Theory (GRT).  In other words if you are not already familiar with this body of work that Dr. Woodward started in 1982, you need to perform due diligence in reading several of the papers that Dr. Woodward, Dr. White and I have written over this time period.  Primarily I'm just the electrical engineer turned experimental physicist that is trying to make this exotic propulsion business work, for without something like it, humanity is doomed to stay inside the asteroid belt for the foreseeable future.  In the meantime if you can't find the papers in question e-mail me a note and I'll be glad to get them to you.

Best,

@PaulMarch

Not sure if you will be able to answer this or not but, are there any plans for EagleWorks to carry out tests on Woodward's M-E devices?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/13/2014 01:21 pm
Previous posts at NBF (of mine) have been pasted here;  so far, I see little love for the position(s) I've taken.

Hah! 

Most of the objections were issues of writing style, but I wouldn't worry about it.  I have "stylistic" issues myself.  Check my deleted post history for details.

Still, from my armchair, the propellantless propulsion "team" gives every impression of being honestly convinced that they have discovered a natural phenomenon which they hope could be harnessed for HSF.

They can barely discern the effect from background noise, and have yet to float the device over the conference room table, in front of investors.  From a stylistic standpoint, I object strenuously to the culturally optimistic projections of missions to Saturn and so forth, particularly when HSF in the immediate neighboorhood is so primitive.

They assert that NASA decisionmakers have to be sold on the sizzle of this speculative future if they are to even get small amounts of money for their research.  This just irks me to think that the folks at NASA keep forgetting the potential for a propellantless drive flight system.

They do not answer questions about what does the device push on.  As I said above,
one could say they have ansered the question about what their devices instantaneously push upon, if and only if any answer were acceptable without experimental proof or without requiring the "answer" to reconcile other theoretical incompatabilities.

So.... many thanks for your algebraic explanation.  I will be sending you a bill for the two or three sheets of used paper that I must now use in order to print this out for my education.

Hope ya don't mind.
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 02:14 pm

@PaulMarch

Not sure if you will be able to answer this or not but, are there any plans for EagleWorks to carry out tests on Woodward's M-E devices?

@birchoff

See this paper by Paul March, Fig.7 and Fig.8, p.1330:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=31119.0;attach=496011

FIGURE 7. Woodward’s Mach-2MHz MLT Test Article, vxB core & March’s Test Stand.
FIGURE 8. Mach-2MHz MLT Test Results - Predicted Thrust is 1.3 / 5.0 Milligram-Force.

and this paper by Dr. White, slide 40:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf

It appears from this that Paul March's/Dr.Woodward's device is the one tested in the 2005 campaign shown by Dr. White giving:

Thrust ~ 3 mN

Specific Force ~ 0.3 N/kW



Title: Re: EM Drive Developments
Post by: GoatGuy on 09/13/2014 02:16 pm
A few caveats :

1. Your calculations are Newtonian mechanics, when approaching c speeds or Thrust/Power ratios below 1/c its no longer valid...

2. Ok so we are breaking energy conservation, great : Noether's theorem show this implies reality not to be time invariant. Hard to swallow much much below cosmological timescales.

3. Ok so energy is conserved but the acquired energy is pumped from vacuum, not free energy but rel cheap energy, great : quoting myself  "tap into vacuum zero-point energy, which would no longer be zero-point...

4. Penultimate point : if the k factor somehow decays with acquired speed ...  it's really difficult to see what would make the system "remember" this particular initial reference frame

5. Last point : the k=0.4 N/kW figure used for the mission profiles implies possible breakeven starting at speeds of 1/k=2.5km/s relative to a fixed frame. ... I'd like to see the experiment done on a freely rotating arm, in an otherwise rotationally symmetric setting around the axis.

Replies...

(1) - Yes, agreed.  However, at the velocities contemplated even to get to the next star, we're way, way below relativistic velocities that require changing the simple math of Newton.  Even doing a "fly thru" to alpha Centauri using the same ship that was proposed to make it to Saturn in 289 days would only be going 8.9% of c in 98 elapsed years.

(2) - We probably agree, but my ignorance of Noether's Theorem is a hindrance.

(3) - I guess this is where I get stuck: if there is some tinderbox of really cheap energy that these things are tapping into, it just kind of breaks down Physics. Even Casimir forces don't break physics: they imply measurable attractive/repulsive forces on micron-to-angstrom scales, between various electromagnetically active materials, and they have been measured to not be much different than envisioned.  Moreover, (sadly for those wishing to employ Casimir force(s) for making free-energy devices), like electromagnetic and gravitational fields, the circular integration of force over any closed path in a Casimir field is exactly zero

(4) - Indeed... the initial reference-frame memory is required if total system energy is to be conserved.  It is the only way that the magical caveat ("system cannot exceed ΔV=2/k ...") can be maintained.  Δ means "change", which means "from initial state".  Hence... yep, we agree.

Personally, I really hope that the effect is real, that it doesn't have "memory issues", that it can be scaled with higher Q devices or higher dielectric piezoelectric quality factors, to far higher 'k' values than the present 5 to 22 µN/W reported levels. The 1/k for these (200,000 m/s to 45,000 m/s respectively) are far too high to employ here on Planet Dirt as alternative energy force generators.  Unobtanium.  But somewhere north of 2 mN/W, the critical 1/k velocity of 500 m/s becomes entirely attainable for large rotors;  COP of 5+ can be imagined as manufacturable, with moderately exotic materials.

GoatGuy
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 02:29 pm
frobnicat <<3. Ok so energy is conserved but the acquired energy is pumped from vacuum, not free energy but rel cheap energy, great : quoting myself  "tap into vacuum zero-point energy, which would no longer be zero-point... >>

GoatGuy <<(3) - I guess this is where I get stuck: >>

How about discussing the actual equations that Dr. White uses to calculate the thrust?

Dr. White uses a "local quantum vacuum density" that is several orders of magnitude larger than the zero-point quantum vacuum density.

(Not that I agree with the physical model they propose, see my previous posts; but it would be interesting to discuss the actual equations he uses instead)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/13/2014 02:39 pm
... the possibilities of delivering grand pianos to Saturn moons for enthusiasts.

Whoah there, kemosabe.  I've never promised anybody a piano.  I only promise ponies. 
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/13/2014 02:39 pm
@GoatGuy, frobnicat,

Your arguments illustrate that the operational principles of the EM drive satisfy Clark's third law - they are, "indistinguishable from magic". Your arguments do not advance our understanding of those principles. Others have taken the risk and dared to postulate principles but I know of none that are accepted. Go ahead, take the risk, postulate physics sufficiently advanced as to cast light on the difference between operation of the EM drive and magic.

Your assertion that the arguments above illustrate that the devices are "indistinguishable from magic", is itself only an assertion.

For purposes of discussion, let us assume that the devices have been theoretically dis-proven to be "indistinguishable from magic".  If the "dis-proof" has been proven, then indeed that does in fact advance our understanding, because we would no longer have to expend time talent and treasure working on a device that will never perform as hoped.

To put it another way, those two avatars are not claiming to be able to build a device which would send a 90 ton spacecracft  to Saturn and return a significant fractional mass of that spacecraft to Earth 788 days later.

The onus of proof is on those who make the extraordinary claim, not on those who find mathematical and theoretical objections to those claims.

Just sayin'.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/13/2014 02:40 pm
Regarding the EM-Drive, I thought it was pretty well established that Shawyer's explanation implied a violation of conservation of momentum, and that thus if the drive worked it would be for some other reason.

That is my recollection as well.  Over on the far too long "Propellantless Propulsion" thread, there was a seemingly valid, to me, disputation of Shawyer's work.

Quote
Basically, your energy balance isn't complete until you've accounted for the device's interaction with the rest of the matter in its Hubble sphere, whatever form that interaction takes.  In other words, you're drawing the box too small.

Furthermore, without something to push on, you aren't just violating conservation of energy; you're violating conservation of momentum too.

I don't care for the various "free energy" claims either.  How do these devices push and pull on all the matter in their Hubble sphere, instantaneously, and in a controlled direction, subject to the whims of the spaceship's driver?

While I am interested in the experimental setup, I am also interested in the theory.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/13/2014 02:40 pm
...all attempts at putting intrinsic frames of reference of space/vacuum or aether back on the table failed experimentally so far ...

I keep on believing in the ether, because it would explain so much, including inertia.

But that's my work, no excuses, no blame to another. 

Quote
I'm against a "what if it works" scenario that won't go to all the inescapable consequences, when the consequences are on firm ground that couldn't possibly be overtaken by the hypothesis.

Bingo.

You do a pretty damn good job with English there, buddy.  What is your native tongue?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/13/2014 02:40 pm

Dr . Woodward answers the question with the following statement:

it is a radiation reaction interaction, presumably, that involves the Wheeler-Feynman ...

I really appreciate your analysis of the experimental setup.  However, Mr. Woodward does not answer any questions at all by saying "presumably".
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/13/2014 02:41 pm
Of course not.  The whole point of the advanced/retarded wave concept in W-F is that you can get instantaneous action at a distance without breaking causality; no momentum or energy or information need travel faster than c.

I objected to the advanced/retarded wave concept here:


Woodward brought up [advanced/retarded wave concept] in his book.  (http://forum.nasaspaceflight.com/index.php?topic=31037.msg1074698#msg1074698)

Cuddihy attempts to explain why my objection is incorrect, but I think he misses my point:

"somehow predicting my whimsical left and right turns" is not correct. (http://forum.nasaspaceflight.com/index.php?topic=31037.msg1075738#msg1075738)

If I am driving a spacecraft which uses the advanced/retarded wave concept as a key principle of its operation, somehow, as I go on a joyride thru the galaxy, those gravitational waves that I'm depending on for propulsion change direction instantaneously with every whimsical turn of my hand on the steering wheel of my spaceship. 

Makes no sense to me.

And it is strange to consider a General Relativity theory where one divorces completely from the Quantum Mechanics arrow of time (the Weak Force), but postulates that gravitational waves travel effectively with infinite speed, as with "action at a distance" (a concept only known in Quantum Mechanics entanglement).

Yeah it is.

Do you [93143] claim that Dr. Woodward misspoke in the video? Or that Dr. Woodward meant that instantaneous action is not an infinite speed? How long a period of time is instantaneous according to Dr. Woodward?

I dunno, but that video is not the body of Mr. Woodward's work.
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 02:47 pm

Dr . Woodward answers the question with the following statement:

it is a radiation reaction interaction, presumably, that involves the Wheeler-Feynman ...

 Mr. Woodward does not answer any questions at all by saying "presumably".

Yes Dr. Woodward clearly said "presumably" (in the video I referenced)  :).  And Dr. Woodward answered only one question -not several questions- in that video.

Please listen to Dr. Woodward's answer again, and if you don't agree he said "presumably" please post the answer you hear he gave: (
[ http://www.youtube.com/watch?v=hn8hqX9JBOE#t=2468 ]
where I have on purpose timed it to when the question is asked, otherwise advance to the end of the presentation at 41:08 minutes (2468 sec))
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/13/2014 02:48 pm
1. Most of the objections were issues of writing style...

2. HSF

3. They can barely discern the effect from background noise (and so) I object strenuously to the culturally optimistic projections of missions to Saturn and so forth...

4. They assert that NASA decisionmakers have to be sold on the sizzle...

5. They do not answer questions about what does the device push on.

6. So.... I will be sending you a bill for the two or three sheets of used paper...

Replies:

(1) Thank the Diety for that.  My style won't likely change, so I can rest satisfied that it'll pique some people's pin-feathers.

(2) HSF.  HSF?  Ah... Human Space Flight.  See... I'm a newbie.

(3) Some experimenters presented a table showing 5.5 to over 21 micronewtons per watt (at under 3 watts input).  Won't float the thruster over the board table, but still getting closer to the levels needed to really "invest deep".  Now, missions to Saturn in 286 days?  Yes, those are galling.

(4) Sizzle, schmizzle. The rather conservative Make-in-Missouri types of NASA want to see a large enough effect with a criteria somewhere around 1 mN/W to challenge existing methods such as Xenon ion drives, which achieve a similar thrust, without requiring the "magic" of pulling on the Universe's Zero-point Wind, etc.  They don't need sizzle.  They need 1 mN/W with the upside potential to make thrust substantially greater than this, theoretically.

(5) What is being deflected is the sense I get: if it is the Universe itself, then that's a pretty startling idea, but not a particularly outrageous one.  Most people don't even give it consideration, but when you or I hop in a car and accelerate onto the highway, we are pushing against the whole Earth, which ever so infintessimally, is accelerated in the opposite direction.  The whole system is MV invariant. 

The reason why I say deflected instead of pushed against is this:  if we are pushing against something (like the Earth, for our car situation), then the amount of energy expended depends on both the initial velocity of the car relative to the pusher-plate, and the change-in-velocity (integration of acceleration) of the vehicle, times its mass.

Or, to put it a bit more succinctly:

P = maV   (mass times acceleration times velocity)...

the higher the V, the more power P is required.  Empirically, in cars this makes sense ... at low velocities, the power of the engine can produce (through gearing) high accelerations.  At high velocities, it cannot.  No magic, just physics.

OK, that being what it is, then if we are pushing against the Universe, then it must be relative to our velocity compared to the universe's velocity frame.  There is no way around that one, I'm afraid.  However, as I recall an analogy trotted forth in another forum about just this, the poster said,

Quote
But Goat, the Mach Woodward is deflecting the intertial energy of the Universe, not unlike how a sailboat's sails are harvesting energy from the passing wind

This is an intriguing idea - because at low velocities (non-relativistic, to be sure), the very fast, very tenuous "inertial wind" could be deflected to produce tangible force, without seeming to diminish as our test vehicle is accelerated to higher velocities.  It is hugely attractive, even if there is little-to-no theory to support the idea.  It also might imply that there wouldn't be directionality anisotropy, as the inertial wind could be directly related to the expansion of SpaceTime itself, which we now know to be ongoing, and accelerating itself.  Energy from latching onto the expansion of the Universe.  Wow.  That'd be a big supply!

(6) OK - I'm glad you used used paper to paper these ideas ideologically.  (Sorry, I couldn't pass the opportunity to pen a sentence that employs double-words in succession, homophones with different meaning.)

GoatGuy
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 03:33 pm
Concerning a critique of Dr. White's QVPT model, besides addressing the actual equations and justification that Dr. White used (including the fact that Dr. White uses a "local quantum vacuum density" several orders of magnitude larger than the zero point quantum vacuum density), a fair analysis would address Dr. White's attempt at analysis of conservation issues. 

(For example the "QVPT Conservation Issues" slide where Dr. White wrote: “Compressed” vacuum serves as potential energy source (like a compressed spring, hence “negative”); “expanding” the vacuum does work on the system which has the net effect of increasing system box’s kinetic energy, etc. etc.).

Title: Re: EM Drive Developments
Post by: frobnicat on 09/13/2014 04:19 pm

2. Ok so we are breaking energy conservation, great : Noether's theorem show this implies reality not to be time invariant. Hard to swallow much much below cosmological timescales.

(2) - We probably agree, but my ignorance of Noether's Theorem is a hindrance.

If you are fighting on the energy conservation ground this is a chief weapon ! Specifically you might be interested in the following link that explains how energy can be NOT conserved on cosmological scales : http://motls.blogspot.fr/2010/08/why-and-how-energy-is-not-conserved-in.html (http://motls.blogspot.fr/2010/08/why-and-how-energy-is-not-conserved-in.html). Don't expect clarifications from me as most "details" are beyond my physics. Bottom line of consequences : yes energy conservation can be considered broken at cosmological scales when space is not asymptotically flat at large distances (but "energy" is by itself an ill-defined concept in this setting), no it's not a practical way to produce energy for free (see comments)
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 04:42 pm
<< we are breaking energy conservation, great : Noether's theorem >>
 <<We probably agree, but my ignorance of Noether's Theorem is a hindrance.>>

Noether's theorem applies to a postulated Lagrangian, if the Lagrangian that was assumed is an incorrect model of physical reality (because it ignores important physical terms, or because it contains mathematical terms that are not a proper model of reality), Noether's theorem cannot correct this error, as Noether's theorem will  not produce a conservation law in accordance with reality.  (Garbage IN, Garbage  OUT applies.  "IN" is the assumed Lagrangian, "OUT" is the conservation law by Noether's theorem ..)

You should ask yourself: were all the relevant energy terms properly defined and included in the assumed Lagrangian?

Noether's theorem doesn't know anything concerning whether the assumed Lagrangian is a proper model of reality...
Title: Re: EM Drive Developments
Post by: Star-Drive on 09/13/2014 05:05 pm
Jose':

I've been involved in testing Dr. Harold Sonny White's Q-Thruster approach to exotic propulsion for seven plus years now, and Dr. James F. Woodward's Mach-Effect (M-E) work for sixteen years. .....
Paul,

Thank you for pointing this out.  I have read with interest several of Dr. Woodward, and Dr. White's papers, including some of your own papers.  It is admirable, in  a sense, to have people willing to pursue research avenues that are not most popular, or commonly accepted.  Concerning Dr. Woodward's, theory, to cut to the chase, as Dr. Woodward himself accepts with a smile in the following presentation (
[ http://www.youtube.com/watch?v=hn8hqX9JBOE#t=2468 ]
where I have on purpose timed it to when the question is asked, otherwise advance to the end of the presentation at 41:08 minutes (2468 sec)) the obvious question to pose to Dr. Woodward is:

If your interpretation of Mach's principle is that inertia is a gravitational reaction from the rest of the Universe (no matter how distant from your center of mass) how come that reaction takes place INSTANTLY ?

In other words, in Dr. Woodward's theory, the propagation of this gravitational reaction responsible for inertia, has INFINITE speed, which is problematic in a Theory of Relativity (where we usually associate gravitational waves to travel at the speed of light).

Dr. Woodward answers with a smile, that "presumably" it is a radiation reaction attributable to Wheeler–Feynman absorber theory.  With his smile and frank facial expression he acknowledges that this is, let's say... problematic?

Because we know that:

A) The Wheeler–Feynman absorber theory assumes that the solutions of the electromagnetic field equations must be invariant under time-reversal symmetry, there is no distinction between past and future.

B)  It therefore assumes that elementary particles are not self-interacting. This is a big drawback of this theory. Indeed, as demonstrated by Hans Bethe, the Lamb shift necessitated a self-energy term to be explained. Feynman and Bethe had an intense discussion over that issue and eventually Feynman himself stated that self-interaction is needed to correctly account for this effect.

C) Wheeler and Feynman conceived of this theory before the Weak Force was understood as it is nowadays.  It is known that the Weak Force implies time-symmetry breaking and gives an arrow of time.  Hence the Weak Force is incompatible with the  Wheeler–Feynman absorber theory, in this sense.

I think that it was wise that you, Dr. White, et.al., decided that <<This paper will not address the physics of the quantum vacuum plasma thruster (QVPT), but instead will describe the recent test campaign>> (Abstract of "Anomalous Thrust Production..." paper).

In that vein, I think it would be best to discuss the experiments without addressing any controversial physical explanation for the time being.


Jose':

"I think that it was wise that you, Dr. White, et.al., decided that <<This paper will not address the physics of the quantum vacuum plasma thruster (QVPT), but instead will describe the recent test campaign>> (Abstract of "Anomalous Thrust Production..." paper).

In that vein, I think it would be best to discuss the experiments without addressing any controversial physical explanation for the time being."

Agreed but it appears others on this forum still want to go down other rabbit trails in pursuit of the holy grail as the additional four pages of posts on the topic since I last looked will attest. :)  However I will point out that Dr. Woodward's M-E conjecture does not need instantaneous Wheeler/Feynman radiation reaction forces or John Wheeler's elliptical constraint equations equivalent of same to allow the M-E conjecture to work as Jim proposes.  It just needs Mach's principle to be an integral part of Einstein's General Relativity Theory (GRT) and that the cosmological gravitational field energy density phi is equal to c^2 in a spatially flat universe.  Woodward has made a very strong case for just these assertions in his published journal papers from 1995 and on, in his ongoing M-E e-mail group, and especially in his 2013 "Making Starships and Stargates" book.  In other words if Einstein's GRT and the original Einstein equivalence principle holds, Mach-Effects are already part of these theoretical monuments if you know where to look for them. 

As to the other theoretical issues you and others have raised in this thread, we probably won't find the final answers to these enigmas until QM, GRT and the Standard Model are seamlessly integrated into a theory of everything (ToE).  (I know, I know, the answer is "42" :) )  Along this path however, I might suggest you consider that QM's supposed "greatest mistake" in calculating the vacuum energy density, (See: http://math.ucr.edu/home/baez/vacuum.html ), isn't a mistake after all, and consider the idea that ALL elementary particles like the electron are in fact 5+D vacuum energy rarefaction vortices like a tornado being balanced and maintained by electrostatic and gravitational forces per Woodward's ADM conjecture.  Past that it really gets strange and removed from experimental facts, so back to the lab work.

BTW, I'm a little late is saying this, but tell Goat Guy that he needs to perform his energy conservation analysis in the 4D GRT formalism and not the flat space-time Newtonian version he's been using to date when performing M-E or Q-Thruster based momentum and energy conservation calculations.  Woodward's 2004 M-E derivation paper's appendix A can show what's needed here.

As for White's Q-Thrusters, energy & momentum conservation is observed by the fact that the vacuum derived propellant has an energy equivalent mass that does have a velocity less than c.  And just like the standard rocket equation, your rocket's maximum obtainable velocity is dependent on the maximum exhaust velocity of the Q-Thruster that is driven by all its local and perhaps gravitational field input energies.  Our current model for same indicates that these vacuum e/p pair like propellant velocities should be in the range of 10,000-to-10,000,000 m/s for the geometries and input power levels we've looked at to date, but of course only if our Q-Thruster model Excel sheet is correct. 

PS:  A Hall thruster's input power to thrust efficiency or specific thrust is around 0.05 N/kWe using today's commercially available thrusters.  Air breathing jet engines can have thrust efficiencies of up to ~75 N/kWe at take off, so assuming a 0.40N/kWe for our Copernicus Orbital calculations is not way out on a limb, and in fact is representative of the performance of my first two Mach-Lorentz Thrusters (MLT) that I built in 2003 and 2004 and reported on in my STAIF-2006 paper.

Now to pay the bills...

Best,

Title: Re: EM Drive Developments
Post by: frobnicat on 09/13/2014 05:13 pm
frobnicat <<3. Ok so energy is conserved but the acquired energy is pumped from vacuum, not free energy but rel cheap energy, great : quoting myself  "tap into vacuum zero-point energy, which would no longer be zero-point... >>

GoatGuy <<(3) - I guess this is where I get stuck: >>

How about discussing the actual equations that Dr. White uses to calculate the thrust?

Dr. White uses a "local quantum vacuum density" that is several orders of magnitude larger than the zero-point quantum vacuum density.

(Not that I agree with the physical model they propose, see my previous posts; but it would be interesting to discuss the actual equations he uses instead)

As I said, my understanding is limited. While I feel confident I can derive some practical consequences of exotic physics, when given phenomenological effects of said exotica (like for instance thrust/power>1/c without expelled reaction mass), as only an engineer by formation I shouldn't feel qualified and shouldn't have the time to dive into the exotic theories by themselves, did too much already. But I will read with great interest, in a state of trance, the ongoing theoretical speculations.

Can't resist. Just to be clear : if some net energy can be extracted from vacuum then something about vacuum is not understood and some other theories are needed. But I don't see how a higher density makes any difference :  the "problem" from my limited pov is to be able to get from vacuum any useful net energy or net thrust at all, however small. Why Dr White needs this higher density vacuum, to reconcile quantitatively with claimed magnitudes ?

Still willing to contribute, if possible, about experimental setup and possible classical explanations of the results.

@John : I'm French, and writing meaningful English is a daily struggle. Better you don't hear me speak English. Just like with advanced physics, I'm just pretending I can do it  ::)
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/13/2014 07:23 pm
To get a... well, obvious question out of the way, if the effect is real, and is predicted to scale up, why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/13/2014 11:20 pm
I am a fascinated lay observer of this topic.

Over the past few years, I have read a couple of articles and books mentioning 'Dark Matter,'  asserting this substance must out-mass (?) conventional matter by something on the order of four or five to one.  Purportedly, this Dark Matter interacts with the rest of the universe only gravitationally.  Could this 'Q Thruster' be somehow interacting Dark Matter?    Or is Dark Matter one and the same with the 'Quantum Vacuum?'

Also, I remember reading mention many years ago that what started the interest in this type of space drive came a as a result of investigating disruptions in the orbits of satellites using microwave devices - the conventional onboard thrusters were having to fire more often to keep the satellites in place.  Any truth to that?  Star Drive?  Rodal? Anybody else?
Title: Re: EM Drive Developments
Post by: Rodal on 09/13/2014 11:39 pm
@ThinkerX

1) <<is Dark Matter one and the same with the 'Quantum Vacuum?'>> No, not at all.  They are not related.  See this link for virtual particles and the quantum vacuum:  http://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/  . 

2) We have "known" about Dark Matter for some time (1930's) because its existence is needed to justify the observed gravitational effects responsible for the orbital velocities of stars in our galaxy and the orbital velocities of galaxies in galaxy clusters.

3) <<Could this 'Q Thruster' be somehow interacting Dark Matter?>> that is NOT the explanation put forth by the principal NASA researcher (Dr. White), nor by Prof. Woodward, or anybody else I know of.  Since it has been difficult to detect dark matter (see http://en.wikipedia.org/wiki/Dark_matter#Detection) I personally think that it is unlikely that dark matter would be responsible for the observed experimental effects.

4) As you may gather from this forum, "opinions" abound.  Groups form just as for example it happens when dealing with any controversial subject like global warming, with "climos" and "detractors" taking positions early on and debating each other.  We need to strive to put on our "scientists" hats, as in the peer-review process, with an open but exacting mind, and examine carefully the experimental results and the different models (equations if possible) put forth to justify the experimental results.  :)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 01:33 am

Dr . Woodward ... it is a radiation reaction interaction, presumably, that involves the Wheeler-Feynman ...

Mr. Woodward does not answer any questions at all by saying "presumably".

Yes Dr. Woodward clearly said "presumably" (in the video I referenced)

Glad we agree.  No questions are "answered" by "presumably", nor by ignoring the body of Mr. Woodwared's work.  But hey.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 01:33 am
Now, missions to Saturn in 286 days?

Thought it was 788.   Never was good with numbers.

Quote
Sizzle, schmizzle...

Well, remember they're selling the sizzle, not the steak, and many other people, some actual scientists included, are asking, 'where's the beef?'

[quote-GoatGuy]But Goat, the Mach Woodward is deflecting the intertial energy of the Universe, not unlike how a sailboat's sails are harvesting energy from the passing wind...[/quote]

Fix your quotes.  'Tweren't me what sed dat.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 01:33 am

To get a... well, obvious question out of the way, if the effect is real, and is predicted to scale up, why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?

Shhhhh.
Title: Re: EM Drive Developments
Post by: birchoff on 09/14/2014 05:09 am

To get a... well, obvious question out of the way, if the effect is real, and is predicted to scale up, why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?

Shhhhh.

There is no conspiracy here, They just havent not proven beyond reasonable doubt that the effect is real. A nice way of characterizing these developments is like seeing smoke rising on the horizon. We would like to believe it is fire but we most investigate (experiment) to find out if our gut feeling is accurate.
Title: Re: EM Drive Developments
Post by: birchoff on 09/14/2014 05:27 am

@PaulMarch

Not sure if you will be able to answer this or not but, are there any plans for EagleWorks to carry out tests on Woodward's M-E devices?

@birchoff

See this paper by Paul March, Fig.7 and Fig.8, p.1330:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=31119.0;attach=496011

FIGURE 7. Woodward’s Mach-2MHz MLT Test Article, vxB core & March’s Test Stand.
FIGURE 8. Mach-2MHz MLT Test Results - Predicted Thrust is 1.3 / 5.0 Milligram-Force.

and this paper by Dr. White, slide 40:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf

It appears from this that Paul March's/Dr.Woodward's device is the one tested in the 2005 campaign shown by Dr. White giving:

Thrust ~ 3 mN

Specific Force ~ 0.3 N/kW

@Rodal

Thanks for the pointers. I was looking for that deck that you linked to on NTRS. I believe Dr. White used it in a presentation I saw this year. Anyway, the most interesting thing about that deck is it seems like there is mounting evidence that there really is something here. Though what I really wonder about is if the Boeing SFE test article had such good results, what happened to it? are there any future plans for further testing on that particular design. I cannot seem to find any information via google or NTRS documenting the test campaign that Boeing device is said to be apart of. I hope it is not covered by NDA...
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/14/2014 05:30 am

To get a... well, obvious question out of the way, if the effect is real, and is predicted to scale up, why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?

Shhhhh.

There is no conspiracy here, They just havent not proven beyond reasonable doubt that the effect is real. A nice way of characterizing these developments is like seeing smoke rising on the horizon. We would like to believe it is fire but we most investigate (experiment) to find out if our gut feeling is accurate.

Star-Drive's been working on this stuff for years, and has built said devices himself, and he seems to be beyond a shadow of a doubt that these devices are real. High power transmitters aren't especially complex devices, and with how long everyone's been fiddling with them, it seems like it would be an effective use of time and money to build a machine that can demonstrate the effect to the naked eye, even if it wasn't useful for anything else.
Title: Re: EM Drive Developments
Post by: Star One on 09/14/2014 08:40 am


To get a... well, obvious question out of the way, if the effect is real, and is predicted to scale up, why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?

Shhhhh.

There is no conspiracy here, They just havent not proven beyond reasonable doubt that the effect is real. A nice way of characterizing these developments is like seeing smoke rising on the horizon. We would like to believe it is fire but we most investigate (experiment) to find out if our gut feeling is accurate.

Star-Drive's been working on this stuff for years, and has built said devices himself, and he seems to be beyond a shadow of a doubt that these devices are real. High power transmitters aren't especially complex devices, and with how long everyone's been fiddling with them, it seems like it would be an effective use of time and money to build a machine that can demonstrate the effect to the naked eye, even if it wasn't useful for anything else.

Why is that every time something like this appears that there is certain strand of belief online that they must have had these for years but kept them secret. It's a depressingly recurrent theme for cutting edge technology whatever the field and I don't know what it is says about scientific literacy in the public at large.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/14/2014 08:47 am
Why is that every time something like this appears that there is certain strand of belief online that they must have had these for years but kept them secret. It's a depressingly recurrent theme for cutting edge technology whatever the field and I don't know what it is says about scientific literacy in the public at large.

I'm not asking why or claiming that he's keeping it secret. I'm asking why a larger one, which would (I hope) help demonstrate that EM drive technology is a real thing, hasn't been built yet.

Title: Re: EM Drive Developments
Post by: Star One on 09/14/2014 12:02 pm
Why is that every time something like this appears that there is certain strand of belief online that they must have had these for years but kept them secret. It's a depressingly recurrent theme for cutting edge technology whatever the field and I don't know what it is says about scientific literacy in the public at large.

I'm not asking why or claiming that he's keeping it secret. I'm asking why a larger one, which would (I hope) help demonstrate that EM drive technology is a real thing, hasn't been built yet.

I wasn't really referring to your post just making a more general point.:)

Back on topic if this passes muster on further ground testing, would it at some point be considered for a tech demonstrator cubesat?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 01:23 pm

...why not build a 33 kilowatt device...

Shhhhh.

There is no conspiracy here...

And no sense of humor either.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 01:57 pm
To get a... well, obvious question out of the way, if the effect is real, and is predicted to scale up, why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?

Seriously, this time:

The cost and difficulty of scaling to that degree is prohibitive.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 02:01 pm
HSF.  HSF?  Ah... Human Space Flight.  See... I'm a newbie.

No problemo.  The acronym directory on this site misses some of the important ones:  TLA, BFR, IDK...
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 02:02 pm
High power transmitters aren't especially complex devices, and with how long everyone's been fiddling with them, it seems like it would be an effective use of time and money to build a machine that can demonstrate the effect to the naked eye, even if it wasn't useful for anything else.

As I point out often, I've been to Arizona, and have a well developed sense of Yuma.

Anybody with both arms on the armchair would realize that scaling the device up to 33kW would be a huge undertaking.

As a BOE yardstick metric, consider the mass of the testing device with the expected forces to be demonstrated.  While the ratio of device mass to detected force might very well decrease should a larger test device be devised, the cost of actually designing and manufacturing the device would require many more people and subcontractors on the team.  So there's that.

Consider also the small vacuum chamber used in this setup.  Larger ones are available, but again, costs would be larger too.

It's not the "complexity" of high power transmitters that is at point; it is rather the ability to reduce the spurious forces from the experimental setup.  It certainly seems like this would be easier to do at a larger scale, but which larger scale?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 02:05 pm
...It's a depressingly recurrent theme for cutting edge technology whatever the field and I don't know what it is says about scientific literacy in the public at large.

For starters, take a quick vacation in Arizona.  [Rolls eyes.]

For seconds, you're confusing the "public at large" with, in my case, a guy who has read, over the last five years, every last word on this topic as presented on this forum, who has downloaded and read every paper, and who has also supported the work by purchasing the author's publications, including Sciama, Ciufolini and Wheeler, and others.  I have a readily detectable mass effect on my bookshelf at least.

Finally, for thirds, the "public at large" believes that warp drive is around the corner, thanks to misleading advertising. 

It isn't.

You may not claim exlusive rights to the term "misleading advertising".  The only promise that the propellantless propuslsion teams should be making, is that they can create a device which repeatably demonstrates that the forces do indeed exist and can be harnessed in practical applications.

No need to invoke the c-word.

As to the theory itself, which should also be discussed, there is this (again):

But (again) I'm against a "what if it works" scenario that wont go to all the inescapable consequences, when the consequences are on firm ground that couldn't possibly be overtaken by the hypothesis.
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 03:19 pm

@Rodal

Thanks for the pointers. I was looking for that deck that you linked to on NTRS. I believe Dr. White used it in a presentation I saw this year. Anyway, the most interesting thing about that deck is it seems like there is mounting evidence that there really is something here. Though what I really wonder about is if the Boeing SFE test article had such good results, what happened to it? are there any future plans for further testing on that particular design. I cannot seem to find any information via google or NTRS documenting the test campaign that Boeing device is said to be apart of. I hope it is not covered by NDA...

******************
Here I compare the experimentally measured Thrust Force and the Specific Force (defined as Thrust Force / Input Electric Power) for the different devices tested at NASA Eagleworks.

From this comparison it appears that the latest round of tested devices (the Cannae and the Fustrum Cavity) have among the lowest measured Thrust Force and the lowest Specific Force.

Since what we are looking for is the highest Thrust Force and the highest Specific Force possible, why is the latest discussion in this forum concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

******************

Referring to slide 40 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf:

The largest THRUST force measured is for Shawyer/SPR Ltd.'s microwave device:

16 to 170 mN

However, it also happens to have among the LOWEST Specific Force (in that slide, but still significantly higher  than the specific forces measured in the latest round for the Cannae and Tapered Frustum cavity -see below):

0.02 to 0.4 N/kW

The largest SPECIFIC FORCE measured is for the Boeing/DARPA device:

1 to 20 N/kW but the upper range was produced only by an unexplained anomalous thrust (one out of 8 pulses)
the average thrust was 3N/kW

but (when compared with the Shawyer/SPR's  device numbers above), with very small thrust force:  20 to 110 uN  (again, the 110 uN is for one anomalous thrust force out of 8 pulses,  the average of the other ones is 20 uN)


Also notice that Dr. White writes

<<The magnitude of the [Boeing/DARPA] thrust scaled approximately with the cube of the input voltage>>
and
<<The magnitude of the [Boeing/DARPA] thrust  is dependent on the AC content of the turn-on and turn-off pulse>>

and I notice:

the Boeing/DARPA measurements show a sudden impulse of very short duration instead of the practically square pulses measured with the latest tested devices (Cannae and (Fustrum) Tapered Cavity). 

It is NOT clear to me whether Dr. White is reporting on measurements his Eagleworks lab conducted on the Shawyer/SPR Ltd.'s device, or whether he is reporting measurements made elsewhere with the Shawyer/SPR Ltd.'s device.
 
////////////////

For the latest round of NASA Eagleworks measurements (in the paper "Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum"):

Cannae Testing:

THRUST Force average:   40 uN
Specific Force:  0.0014 N/kW
______________________________

Tapered (Frustum) Cavity Testing: 

THRUST Force average: 50 to 90 uN
Specific Force:  0.003 N/kW to 0.0054 N/kW

Where I obtained the "Specific Force" by dividing the Thrust Force by the Input Electric Power (for example, for the Tapered Cavity 16.9 Watts electric).

////////////////

Everybody: please take a look at this comparison, and provide some feedback as to why the latest discussion in this forum is concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

Have I misinterpreted something in the above comparison?
If so, how is the Specific Force calculated in slide 40 of Dr. White's presentation in the above link and elsewhere in his papers?

Also notice that <<Figure 25. 2MW NEP (90t spacecraft) Crewed Titan/Enceladus Mission with 0.4N/kWe thrust to power>> in the "Anomalous thrust..." paper uses 0.4N/kW (compare this with the Boeing/DARPA figure given in slide 40 above, which is 1 to 20 N/kW).  Of course I do understand that the  Crewed Titan/Enceladus Mission must have assumed an amount of thrust much larger than the minute thrust measured at Eagleworks for the Boeing/DARPA device  :), and that must be also the object of your criticism (the assumption that the devices can be eventually scaled up to produce required thrust and specific forces)

Title: Re: EM Drive Developments
Post by: cuddihy on 09/14/2014 03:35 pm

I have a readily detectable mass effect on my bookshelf at least.

Thread winner! Nice quip John.

As for the "why no cubesat test," so far I don't believe any of the testing of Eagleworks has been of steady-state devices, and when you factor in how much the power circuits would add to the mass, at current force levels you would need a lot of sustained thrust time to see an orbital mechanics effect from ground-based observation.
Title: Re: EM Drive Developments
Post by: Stormbringer on 09/14/2014 04:43 pm

Finally, for thirds, the "public at large" believes that warp drive is around the corner, thanks to misleading advertising. 

It isn't.


Oh, i am not the public at large either. but i think warp drive or something of that general class of thing really is around the corner. not because the hard data warrants that perception. but because the trend of discovery seems to suggest it.

A decade or two ago you would find as close to absolute silence on the topic as possible. now there are papers on university experiments and experimental labs, commercial industry investigations such as boeing. Govt investigations such as NASA all using several different approaches and apparatuses. I have now seen solutions to Relativity maths that support the things. I have flat out seen Science (<---personification) begin to "admit" that Gravity and several forces are related. E'G; an article where Tajmar's experiment was discussed Revealed that GR predicts a coupling of gravity and magnetism or gravity and EM. At that point Tajmar and his results become secondary (good thing too) what became central to me was that GR actually says: Gravity and magnetism or EM are coupled, related and therefore interchangeable.

That's just one example.  So lately science has been cooperating with my plans to obtain a star cruiser.

I have a media reporting rule of thumb about research and articles on research. if there is one article and then silence then the research will produce no fruit. if you have a later article well something could happen, maybe. but if you have three on the same topic over time then you will probable see fruit from it in the future. it works more often that it fails. that's what rule of thumb means.  but i am optimistic. probably more than warranted. But i think that sooner rather than later someone will find the key and unlike fusion's timeline, one of these EM things or a similarly scientifcally disreputable thing will be reality.
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 05:22 pm
To put this comparison more bluntly:

Ratio of measurements for Shawyer/SPR Ltd.'s device compared to Cannae's device:

THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

_____________________________________________________________________________

Ratio of measurements for Boeing/DARPA's device compared to Cannae's device:

THRUST FORCE: 0.5 to 2.75 times higher for Boeing/DARPA's device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power): 714 to 14300 times higher for Boeing/DARPA's device than for Cannae's device

_____________________________________________________________________________

Since what we are looking for is the highest Thrust Force and the highest Specific Force possible, why is the latest discussion in this forum concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?
Title: Re: EM Drive Developments
Post by: aero on 09/14/2014 06:12 pm
A general question, but related if it has the right answer. :)

Say that you set up a Casimir force experiment using two parallel plates close together and detected the Casimir force. What would happen to the force if you somehow transmitted a powerful RF energy beam between the plates?

Hint -
a. nothing
b. the force decreases
c. the force increases.
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 09/14/2014 06:13 pm
Hi,
@Rodal: For a long time there was social pressure against Shawyer results and people were reluctant to show support. Shawyer was not supported by a big organization, but when DARPA in 2011 gave lots of publicity to Dr White at 100YSS conference, people's stance changed. Because this time, such research was supported by big organisations (as Stormbringer just said in his last post).
Title: Re: EM Drive Developments
Post by: Star One on 09/14/2014 06:15 pm


I have a readily detectable mass effect on my bookshelf at least.

Thread winner! Nice quip John.

As for the "why no cubesat test," so far I don't believe any of the testing of Eagleworks has been of steady-state devices, and when you factor in how much the power circuits would add to the mass, at current force levels you would need a lot of sustained thrust time to see an orbital mechanics effect from ground-based observation.

Thanks for answering this. So it's going to need a lot more development to get to this stage then.
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 06:17 pm
Hi,
@Rodal: For a long time there was social pressure against Shawyer results and people were reluctant to show support. Shawyer was not supported by a big organization, but when DARPA in 2011 gave lots of publicity to Dr White at 100YSS conference, people's stance changed. Because this time, such research was supported by big organisations (as Stormbringer just said in his last post).
Hi,

@JPLeRouzic:  Do you know whether the (Thrust Force and Specific Force) numbers given by Dr. White in his slide 40 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf for Shawyer/SPR Ltd.'s device are for

A) experimental results for Shawyer/SPR Ltd.'s device obtained at his NASA Eagleworks Lab?,
or
B) is Dr. White reporting (Thrust Force and Specific Force) numbers obtained elsewhere ?

_____________________________________

This is the text in slide 40 of Dr. White's presentation:

<<
SPR Ltd. Has produced several Microwave test articles. Claim is they produce thrust with just electric power input.

• Shawyer’s theoretical model has been deemed non-viable by scientific community (rightly so)

Thruster assessed against Q-thruster models and analysis suggests this may be a microwave version of a quantum vacuum plasma thruster.

• Tapered shape creates virtual toroid of active volume that can realize net thrust in virtual plasma.
• Microwave Q-thrusters would not be restricted to tapered construction.

16-170 mN Thruster
Specific Force 0.02-0.4N/kW


Prototype 16mN @ 850W,  0.02N/kW
Dynamic Test Article 96mN @ 334W, 0.3N/kW
High fidelity Test Article 170mN @ 450W, 0.4N/kW

Thrust magnitude increased over multiple test devices from 16 to 170mN

If Q-Thruster theory accounts for measured force, then microwave test articles may have ability to reach >10N/kW


Chinese university claims to have duplicated EM Drive tests , but no way for U.S. to evaluate credibility (so we have ignored it)

16-170 mN Thruster
Specific Force 0.02-0.4N/kW

>>
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 06:34 pm
This is the text for Boeing/DARPA in slide 40 of Dr. White's presentation (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf ):

<<SFE Test Article at JSC

In 2013, Boeing/DARPA sent Eagleworks Lab an SFE test article for testing and evaluation

Evaluation of the test article in and out of a Faraday Shield performed from Feb through June 2013.

• There is a consistent transient thrust at device turn-on and turn-off that is consistent with Qthruster physics
• The magnitude of the thrust scaled approximately with the cube of the input voltage (20-110uN).
• The magnitude of the thrust is dependent on the AC content of the turn-on and turn-off pulse
• Specific force of transient thrust was in the ~1- 20 N/kW range.

~20-110 uN Thrust Pulses
Specific Force ~1-20N/kW
>>

NASA Eagleworks also provided this information in a 2013 Newsletter, which is available in the Internet from this link:  https://xa.yimg.com/kq/groups/86787010/513081407/name/Eagleworks+Newsletter+2013.pdf

that reads:

<<NASA/Boeing/SFE Campaign: Boeing/DARPA sent Eagleworks Lab an SFE test article for testing and
evaluation. The guest thruster was evaluated in numerous test configurations using varying degrees of
Faraday shielding and vacuum conditions. Observations show that there is a consistent transient thrust
at device turn-on and turn-off that is consistent with Q-thruster physics. The magnitude of the thrust
scaled approximately with the cube of the input voltage (20-110uN). The magnitude of the thrust is
dependent on the AC content of the turn-on and turn-off pulse. Thrust to power of transient thrust was
in the ~1-20 N/kW range

Peak + Current at 20kV: ~331nA
Peak - Current at 20 kV: ~280nA
Average On/Off thrust pulse= 19.9uN
Specific Thrust = 3.25 N/kWe

~110uN Anomalous Turnoff Pulse with same peak input power implies: ~18.0 N/kWe.>>
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/14/2014 07:34 pm
Rodal-

Regarding the tests of the Boeing Device, and how the thrust was much greater than with the  Shawyer device:

You began your posts here with a strong suspicion the Shawyer results, at least were likely the result of thermal artifacts.  Would such a suspicion still be warranted with the much more impressive results for the Boeing device?

Also:  thank you for the links on quantum particles and Dark Matter.  One of the reasons I brought up Dark Matter in the first place was because you were concerned that Doctor White postulated far to great a quantum vacuum density.  I was wondering if the Dark Matter density might be sufficient to resolve this, and maybe better account for the 'arrow of time' issues you were discussing earlier. 

That said:

[humor] possibly these various engineering teams could benefit from having a good English teacher writing, or at least critiquing their papers?  Seems to me a fair part of what we are discussing here might be resolved with clearer writing in the reports. [/humor]

Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 07:47 pm
Rodal-

Regarding the tests of the Boeing Device, and how the thrust was much greater than with the  Shawyer device:


@ThinkerX

No, you have this backwards.  The reported thrust force for the Shawyer/SPR Ltd.'s device are 800 to 1500 times larger than the reported thrust force numbers for the Boeing/DARPA's device.

It is the reported specific force that is greater for the Boeing/DARPA device than for the Shawyer/SPR Ltd.'s.

But, although Dr. White tested the Boeing/DARPA device, as I stated it is NOT clear whether Dr. White is reporting numbers measured at NASA Eagleworks for the Shawyer device or numbers that were measured elsewhere at other labs.
Title: Re: EM Drive Developments
Post by: aero on 09/14/2014 07:52 pm

an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf)

In particular, I find the Math toward the end of the slide show  interesting.
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 07:54 pm
Rodal-

....

You began your posts here with a strong suspicion the Shawyer results, at least were likely the result of thermal artifacts.  Would such a suspicion still be warranted with the much more impressive results for the Boeing device?

....

@ThinkerX,

I began my posts with an e-mail I sent to Dr. White concerning his latest testing campaign with the Cannae and the Fustrum Cavity drive.  I never mentioned the Shawyer results in that e-mail/post. 

I cannot comment at this point on the reported numbers for Shawyer, I don't even know whether Dr.White performed those tests or he is simply reporting numbers tested elsewhere. 

***I fully admit to have been confused, and I am still confused as to whether Dr. White ever tested Shawyer's drive or whether he just reported in Power Point slides results obtained for Shawyer's drive elsewhere.  At one point in time I assumed (perhaps incorrectly) that the Fustrum "Tapered Cavity" device tested by Dr. White in his last campaign was another type of Shawyer's  drive.   If somebody could clarify this it would be much appreciated  :)

Concerning the Boeing/DARPA device all I have is that slide (and the similar information in the newsletter) I reported.  I am trying to have people at this forum clarify the numbers I posted, to verify that my reading is correct.  Furthermore I do not have any report on precisely how the Boeing/DARPA device was tested, and I made a point that the measurements of the Boeing/DARPA device show a very short-duration impulse (which Dr.White says is associated with on/off AC) instead of the rectangular pulses of longer duration observed with other devices.
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 07:59 pm
Rodal-

...One of the reasons I brought up Dark Matter in the first place was because you were concerned that Doctor White postulated far to great a quantum vacuum density. ...

**** I write the following as an explanation  :D .  I fully understand that the subject we are addressing is complicated, a lot of the information is in PowerPoint presentations and not in full papers, so a lot is subject to interpretation - please consider that my interpretation may be wrong !****

No, I was NOT "concerned that Doctor White postulated far too great a quantum vacuum density". On the contrary. Instead I stated that Dr. White used in his mathematical calculations a value for a "local quantum vacuum density" that is several orders of magnitude higher than the zero-point quantum vacuum density.

This was to answer @frobnicat and others in this forum that were criticizing Dr. White's theory on the basis that if the quantum vacuum density is already a zero-point density, obviously one cannot extract any energy from it, because it is already at the zero-point.  @frobnicat's argument is entirely correct (if somebody would be using the zero-point energy -which Dr. White did not do), that's why great physicists like Pauli, Feynman, de Witt and Schwinger abhorred the explanation for the Casimir effect based on "negative energy" and "negative mass".  I completely agree with Schwinger's explanation that the Casimir effect does not involve any "negative energy" or "negative mass".  Schwinger's explanation (based on a retarded charge effect, a van der Waal force) is what is taught at MIT -nothing to do with "negative energy".   

Furthermore, Dr. White didn't "postulate" a value several orders of magnitude higher for the "local quantum vacuum" out of thin air.  On the contrary, Dr. White derived (based on a Mean Free Path argument) this higher value for the local quantum vacuum.

Essentially I was asking people on this forum to read Dr. White's equations, and address Dr. White's theory instead of a toy model that is NOT Dr. White's theory.

And do NOT take what I write here as a sponsorship of Dr. White's theory either.  I am just asking for a fair peer-review of Dr. White's theory. 

If you ask for my personal viewpoint I would still seek for an explanation using more conventional physics, as for example when Schwinger successfully explained the Casimir effect.
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 08:36 pm
One of the reasons I brought up Dark Matter in the first place was because you were concerned that Doctor White postulated far to great a quantum vacuum density.  I was wondering if the Dark Matter density might be sufficient to resolve this, and maybe better account for the 'arrow of time' issues you were discussing earlier. 

That said:

[humor] possibly these various engineering teams could benefit from having a good English teacher writing, or at least critiquing their papers?  Seems to me a fair part of what we are discussing here might be resolved with clearer writing in the reports. [/humor]

You might be right.  An Astrophysicist I know also brought Dark Matter as a possible explanation.  However, another issue I brought in the discussion with him (besides the fact that we have not been able to directly detect Dark Matter and find out exactly what kind of weakly interacting massive particle it is, is that the amount of Dark Matter in our location in the Galaxy is very small according to some numerical solutions of gravitational models based on measurements.  The  Astrophysicist retaliated showing that this is hotly debated, and there is an excellent team at Harvard that a) thinks that the amount of Dark Matter is larger (than in the paper that said the amount was small) and b)thinks that we may know soon how much Dark Matter is around the Earth.
_________________________

Also observe that an interpretation of Dr. White's theory is that it involves Dark Energy, instead of Dark Matter, because Dark Energy is related to the cosmological constant in General Relativity, which is the vacuum energy.

Dr. White also has some interesting ideas on gravity, as an emergent force and not a fundamental force (yes I know that there is good criticism of the idea of gravity as an emergent force...).

_________________________

Concerning <<might be resolved with clearer writing >> I fully agree, starting with my own writings  :) .  We try to do our best  :)

Fortunately, in a forum like this, it is "a work in progress" and we can, as a crowd, arrive at a better understanding. :)
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 08:39 pm

an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf)

In particular, I find the Math toward the end of the slide show  interesting.

Thanks @aero for bringing this up. I wish we would address slides 56 to 60 of this paper   :)

**** and I don't mean this as a criticism, the equations of Dr. White are scattered in several Power Point slide presentations, I have NOT been able to find them all contained in a single entire paper
I mean this constructively, the more we address Dr. White's equations, the more fair our assessment and also the better we will understand whether his explanations are plausible or not
Title: Re: EM Drive Developments
Post by: bad_astra on 09/14/2014 09:52 pm
Can we please not try to drum up goatguy on this forum?
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 10:11 pm

Done
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 11:20 pm

I have a readily detectable mass effect on my bookshelf at least.

Thread winner! Nice quip John.

As for the "why no cubesat test," so far I don't believe any of the testing of Eagleworks has been of steady-state devices, and when you factor in how much the power circuits would add to the mass, at current force levels you would need a lot of sustained thrust time to see an orbital mechanics effect from ground-based observation.

Yet, that is exactly what is necessary.  The terrestrial based apparatus seems subject to many more constraints than a free body experiment would be subject to. Don't tell the proponents that I'm suggesting an appropriate scaling up of their apparatus.  They have neither a sense of humor nor perspective.
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 11:34 pm

I have a readily detectable mass effect on my bookshelf at least.

Thread winner! Nice quip John.

As for the "why no cubesat test," so far I don't believe any of the testing of Eagleworks has been of steady-state devices, and when you factor in how much the power circuits would add to the mass, at current force levels you would need a lot of sustained thrust time to see an orbital mechanics effect from ground-based observation.

Yet, that is exactly what is necessary.  The terrestrial based apparatus seems subject to many more constraints than a free body experiment would be subject to. Don't tell the proponents that I'm suggesting an appropriate scaling up of their apparatus.  They have neither a sense of humor nor perspective.

Given that (see my previous post)

THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

1) Would you consider the Shawyer/SPR Ltd.'s device a "scaled-up" version of the Cannae device -last tested at NASA Eagleworks as per the "Anomalous thrust ..." paper-?

or

2) Are the numbers quoted by Dr. White for Shawyer/SPR Ltd.'s device  unrepresentative because of A) some mistake I made in my interpretation or B) because Dr. White did NOT test  Shawyer/SPR Ltd.'s device and the numbers he quoted were measured elsewhere?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/14/2014 11:38 pm
Everybody: please take a look at this comparison, and provide some feedback as to why the latest discussion in this forum is concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

Well, I'll tell ya.  The "body" of the work, that I mentioned earlier, is based on an interpretation of Mach, as explained further by Sciama.  With their successive experiments, the experimenters appear to move the mathematical goalposts.  I know that I can't keep up. 

But pragmatically, what happens, is you guys up there talking about all sorts of "effects" and what-have-you, and no reasonably educated infividual can keep up.

Assuming, of course, for purposes of argument, that the term "reasonably educated" only includes that group of people who completely and totally understand, including, without apparent limitations, how to recover the recover the Lamb Shift,  radiation interactions, gravity waves,  Wheeler and Feynman (their theory of the Weak Force), the advanced/retarded wave concept, the cosmological arrow of time, 2nd law of Thermodynamics (which should be sufficient), Weak Force arrow of time, particle radiation, Quantum Mechanics (which is to be expected), the concept of action at a distance, inertia, QM entanglement, prima facie rejection of various premises, time-asymmetry, Wheeler-Feynman absorber theory (oops, we already kinda sorta included that), the "Chung-Freese" metric (to which I admit freely and willingly, total ignorance of, even as a collection of letters)... I give up.

My mathematical defeat doesn't prove success to the method, nor guarantee the expected operation  of the experimental apparatus.

Bottom line, and doubling as executive summary; the effect is not explained for or to the edification of the reasonably educated individual.

We give it our best shot.
Title: Re: EM Drive Developments
Post by: Rodal on 09/14/2014 11:46 pm
Everybody: please take a look at this comparison, and provide some feedback as to why the latest discussion in this forum is concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

Well, I'll tell ya.  The "body" of the work, that I mentioned earlier, is based on an interpretation of Mach, as explained further by Sciama.  With their successive experiments, the experimenters appear to move the mathematical goalposts.  I know that I can't keep up. 

But pragmatically, what happens, is you guys up there talking about all sorts of "effects" and what-have-you, and no reasonably educated infividual can keep up.

Assuming, of course, for purposes of argument, that the term "reasonably educated" only includes that group of people who completely and totally understand, including, without apparent limitations, how to recover the recover the Lamb Shift,  radiation interactions, gravity waves,  Wheeler and Feynman (their theory of the Weak Force), the advanced/retarded wave concept, the cosmological arrow of time, 2nd law of Thermodynamics (which should be sufficient), Weak Force arrow of time, particle radiation, Quantum Mechanics (which is to be expected), the concept of action at a distance, inertia, QM entanglement, prima facie rejection of various premises, time-asymmetry, Wheeler-Feynman absorber theory (oops, we already kinda sorta included that), the "Chung-Freese" metric (to which I admit freely and willingly, total ignorance of, even as a collection of letters)... I give up.

My mathematical defeat doesn't prove success to the method, nor guarantee the expected operation  of the experimental apparatus.

Bottom line, and doubling as executive summary; the effect is not eplained for or to the edification of the reasonably educated individual.

We give it our best shot.

What you discuss up there are interpretations based on controversial theories (even including higher-dimensional Chung-Freese  :) ).  Instead what I ask has nothing to do with interpretations.  What I ask is concerning the experimental results (NO theory).  According to the numbers I quoted, the Shawyer/SPR Ltd.'s device has a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae's.   Is that correct?

Don't get Chung-Freesed here  :) .  Don't escape in a Chung-Freese brane through a 4-D wormhole  :)

Just look at the thrust numbers   Keep your eyes on the numbers.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/14/2014 11:57 pm
As someone said before and in agreement on the experimentalist side of things...
Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust?
We wouldn't need vacuum chambers or any nonsense.
Why not?
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 12:00 am
As someone said before and in agreement on the experimentalist side of things...
Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust?
We wouldn't need vacuum chambers or any nonsense.
Why not?

Do we need to go to 100kW to know the following: Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or not?  Did Dr. White's lab test the Shawyer/SPR Ltd.'s device, yes or not?

Can someone in this forum answer that, please  :)?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/15/2014 12:04 am
As someone said before and in agreement on the experimentalist side of things...
Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust?
We wouldn't need vacuum chambers or any nonsense.
Why not?

Do we need to go to 100kW ? Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or not?
Ok, start at 1KW then 10KW then 100KW...
The point is its much easier (I think) to construct higher power devices than to detect low thrust levels.
If a 1KW device was to slide down an air-track then the world would change...
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 12:06 am
As someone said before and in agreement on the experimentalist side of things...
Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust?
We wouldn't need vacuum chambers or any nonsense.
Why not?

Do we need to go to 100kW ? Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or not?
Ok, start at 1KW then 10KW then 100KW...
The point is its much easier (I think) to construct higher power devices than to detect low thrust levels.
If a 1KW device was to slide down an air-track then the world would change...

OK I completely agree with you and JohnFornaro on that.  Now,

Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or not?  Did Dr. White's lab test the Shawyer/SPR Ltd.'s device, yes or not?

Can someone in this forum answer that, please  :)?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/15/2014 12:07 am
I don't know
and
I don't know
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/15/2014 12:09 am
Quote
an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf

In particular, I find the Math toward the end of the slide show  interesting.

I ran through the slideshow a couple times.  (Am I to interpret the first part as meaning that actual, successful, 'bench-top' warp field experiments have already been conducted?)

The 'mission calculations' for Q-Thruster spacecraft were interesting.  Proxima Centauri in under 30 years?  (Which might also mean a very roughly time to reach Tau Ceti or some such - longer period for acceleration.)

The math in the last section defeated my feeble skills in short order.  The notion of gravity as emergent from vacuum energy, rather than fundamental in and of itself is something I have not come across before.  Wouldn't this have implications for relativity?  Again, the math beat me.

As too...

Quote
THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

1) Would you consider the Shawyer/SPR Ltd.'s device a "scaled-up" version of the Cannae device -last tested at NASA Eagleworks as per the "Anomalous thrust ..." paper-?

or

2) Are the numbers quoted by Dr. White for Shawyer/SPR Ltd.'s device  unrepresentative because of A) some mistake I made in my interpretation or B) because Dr. White did NOT test  Shawyer/SPR Ltd.'s device and the numbers he quoted were measured elsewhere?

Something crucial is missing here.  We have independent (?) groups building mechanisms based on different theories (?), all of which apparently produce positive results (?) of differing magnitudes.   Yet, at best it takes...uncomfortable assumptions... to make these results square with existing theory.   Two thoughts:

First, 'Plato's Cave:' imagine a group of people confined in a large dim room, which so far as they know is the sum total of the universe.  Flickering lights make shadow images on the wall, from which they deduce, or attempt to deduce how their world functions.  Their interpretation of these images becomes quite sophisticated, yet the images remain just that: an image of reality rather than reality itself.    At the Quantum or Dark Energy level, something similar may be in effect here - the theories and models used describe what is *apparently* happening, rather than what is *actually* happening, and worse our innate limitations are such we can't go from one to the other.    The models and theories will always be flawed, and this flaw somehow accounts for (part?) of the differing test results.   (apologies for the horribly botched explanation of Plato's Cave.)

Second thought...been a long, long time since I did any reading on it, as it was considered far fetched fringe material way back in the 70's and 80's...but wasn't there a fellow named Townsend Brown mucking around with something vaguely similar to 'Q-Thrusters' forty or fifty years ago?  Seem to remember the UFO types (apologies again) were all over his work.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 12:11 am
I don't know
and
I don't know

Thank you

and

Thank you
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/15/2014 12:16 am
I don't know
and
I don't know

Thank you

and

Thank you

Now. Will you answer why higher power devices have not been tested?
My opinion: They have and it works, therefore Top Secret.
What can you say?
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 12:20 am
I don't know
and
I don't know

Thank you

and

Thank you

Now. Will you answer why higher power devices have not been tested?
My opinion: They have and it works, therefore Top Secret.
What can you say?

I don't know  :)

and

I have no idea

and

If I would know that the answer is top secret, I certainly would not be able to answer it anyway   :)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/15/2014 12:24 am


I have a readily detectable mass effect on my bookshelf at least.

Thread winner! Nice quip John.

As for the "why no cubesat test," so far I don't believe any of the testing of Eagleworks has been of steady-state devices, and when you factor in how much the power circuits would add to the mass, at current force levels you would need a lot of sustained thrust time to see an orbital mechanics effect from ground-based observation.

Thanks for answering this. So it's going to need a lot more development to get to this stage then.
Now. Will you answer why higher power devices have not been tested?
My opinion: They have and it works, therefore Top Secret.
What can you say?
Title: Re: EM Drive Developments
Post by: birchoff on 09/15/2014 12:26 am
To put this comparison more bluntly:

Ratio of measurements for Shawyer/SPR Ltd.'s device compared to Cannae's device:

THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

_____________________________________________________________________________

Ratio of measurements for Boeing/DARPA's device compared to Cannae's device:

THRUST FORCE: 0.5 to 2.75 times higher for Boeing/DARPA's device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power): 714 to 14300 times higher for Boeing/DARPA's device than for Cannae's device

_____________________________________________________________________________

Since what we are looking for is the highest Thrust Force and the highest Specific Force possible, why is the latest discussion in this forum concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

I think the answer to this question is simply because EagleWorks only presented a paper that outlined tests on the Cannae and Tapered Frustum. I am equally puzzled as you, since the Boeing device seems to be much more interesting. But outside of the deck and the 2013 update you linked to there is ZERO information about the Boeing test article which I find very curious given the results. From the 2013 update you linked to before, it looks like the Boeing device was tested along side the Cannae and Tapered Frustum. So unless there is some sort of NDA in place or some sort of time constraint on compiling the information necessary for inclusion in the paper or some combination there of. I cannot see a reason for why it wouldn't be included.

On a separate note, from the limited information available I am beginning to wonder if the Boeing device wasn't a Mach Effect/Woodward Effect device.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 12:35 am
To put this comparison more bluntly:

Ratio of measurements for Shawyer/SPR Ltd.'s device compared to Cannae's device:

THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

_____________________________________________________________________________

Ratio of measurements for Boeing/DARPA's device compared to Cannae's device:

THRUST FORCE: 0.5 to 2.75 times higher for Boeing/DARPA's device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power): 714 to 14300 times higher for Boeing/DARPA's device than for Cannae's device

_____________________________________________________________________________

Since what we are looking for is the highest Thrust Force and the highest Specific Force possible, why is the latest discussion in this forum concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

I think the answer to this question is simply because EagleWorks only presented a paper that outlined tests on the Cannae and Tapered Frustum. I am equally puzzled as you, since the Boeing device seems to be much more interesting. But outside of the deck and the 2013 update you linked to there is ZERO information about the Boeing test article which I find very curious given the results. From the 2013 update you linked to before, it looks like the Boeing device was tested along side the Cannae and Tapered Frustum. So unless there is some sort of NDA in place or some sort of time constraint on compiling the information necessary for inclusion in the paper or some combination there of. I cannot see a reason for why it wouldn't be included.

On a separate note, from the limited information available I am beginning to wonder if the Boeing device wasn't a Mach Effect/Woodward Effect device.

Please also consider that:

A) The Boeing/DARPA measurements show a sudden impulse of very short duration instead of the practically rectangular pulses measured with the latest tested devices (Cannae and (Fustrum) Tapered Cavity).   That may be a problem concerning the Boeing/DARPA device as what is needed is steady state thrust.

and

B) NO Information gets out on top secret work.  None.  Nada.  At the time of the Manhattan Project you didn't have snapshots with small amounts of information.  You had nothing getting out.  The NASA Eagleworks 2013 update on the Boeing/DARPA device (look at the link) seems to be on a Yahoo server with the address xa.yimg.com. All of these are servers that host the graphic images of Yahoo pages (y=Yahoo + img=image).
Title: Re: EM Drive Developments
Post by: birchoff on 09/15/2014 12:37 am

I have a readily detectable mass effect on my bookshelf at least.

Thread winner! Nice quip John.

As for the "why no cubesat test," so far I don't believe any of the testing of Eagleworks has been of steady-state devices, and when you factor in how much the power circuits would add to the mass, at current force levels you would need a lot of sustained thrust time to see an orbital mechanics effect from ground-based observation.

Yet, that is exactly what is necessary.  The terrestrial based apparatus seems subject to many more constraints than a free body experiment would be subject to. Don't tell the proponents that I'm suggesting an appropriate scaling up of their apparatus.  They have neither a sense of humor nor perspective.

As a proponent for continued experimentation into these types of devices, I can say that I would love to see them scaled up and tested in a cubesat. However, I am also aware that nothing is that easy. These devices have not been proven to be real effects yet. which means we have no clue what the operating parameters are. Now as long as there are experiments we can do on terra firma that are cheaper. My vote is to complete those experiments first. Once that is done we can begin planning the cubesat version.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/15/2014 12:51 am
Why is that every time something like this appears that there is certain strand of belief online that they must have had these for years but kept them secret. It's a depressingly recurrent theme for cutting edge technology whatever the field and I don't know what it is says about scientific literacy in the public at large.

I'm not asking why or claiming that he's keeping it secret. I'm asking why a larger one, which would (I hope) help demonstrate that EM drive technology is a real thing, hasn't been built yet.


not sure, but considering Star Drive is a electric-engineer, I am certain he has a good explanation for why not.

for Mach Effect devices, I know they need piezo-electric materials and ceramics that are just too expensive for anyone without some good financial backup.
Title: Re: EM Drive Developments
Post by: birchoff on 09/15/2014 12:54 am
To put this comparison more bluntly:

Ratio of measurements for Shawyer/SPR Ltd.'s device compared to Cannae's device:

THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

_____________________________________________________________________________

Ratio of measurements for Boeing/DARPA's device compared to Cannae's device:

THRUST FORCE: 0.5 to 2.75 times higher for Boeing/DARPA's device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power): 714 to 14300 times higher for Boeing/DARPA's device than for Cannae's device

_____________________________________________________________________________

Since what we are looking for is the highest Thrust Force and the highest Specific Force possible, why is the latest discussion in this forum concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

I think the answer to this question is simply because EagleWorks only presented a paper that outlined tests on the Cannae and Tapered Frustum. I am equally puzzled as you, since the Boeing device seems to be much more interesting. But outside of the deck and the 2013 update you linked to there is ZERO information about the Boeing test article which I find very curious given the results. From the 2013 update you linked to before, it looks like the Boeing device was tested along side the Cannae and Tapered Frustum. So unless there is some sort of NDA in place or some sort of time constraint on compiling the information necessary for inclusion in the paper or some combination there of. I cannot see a reason for why it wouldn't be included.

On a separate note, from the limited information available I am beginning to wonder if the Boeing device wasn't a Mach Effect/Woodward Effect device.

Please also consider that:

A) The Boeing/DARPA measurements show a sudden impulse of very short duration instead of the practically rectangular pulses measured with the latest tested devices (Cannae and (Fustrum) Tapered Cavity).   That may be a problem concerning the Boeing/DARPA device as what is needed is steady state thrust.

and

B) NO Information gets out on top secret work.  None.  Nada.  At the time of the Manhattan Project you didn't have snapshots with small amounts of information.  You had nothing getting out.  The NASA Eagleworks 2013 update on the Boeing/DARPA device (look at the link) seems to be on a Yahoo server with the address xa.yimg.com. All of these are servers that host the graphic images of Yahoo pages (y=Yahoo + img=image).

Agreed on the top secret comment. But a NDA is a little bit more forgiving than declaring something Top Secret. For example EagleWorks could have been allowed to only report on the results. Which is what they did. Compared to the Cannae and Tapered device where they were able to report on their construction and the testing protocol.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/15/2014 12:59 am

an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf)

In particular, I find the Math toward the end of the slide show  interesting.

Thanks @aero for bringing this up. I wish we would address slides 56 to 60 of this paper   :)

**** and I don't mean this as a criticism, the equations of Dr. White are scattered in several Power Point slide presentations, I have NOT been able to find them all contained in a single entire paper
I mean this constructively, the more we address Dr. White's equations, the more fair our assessment and also the better we will understand whether his explanations are plausible or not

desperate attempt, please don't read and ignore unless you are yourself desperate :

I understand the interest of addressing those equations but at this level I just can do dimensional analysis (first glance seems ok, but then one wouldn't expect otherwise). Quantitatively from the equations couldn't tell deep insights from mere numerology. A few slides but no paper to the scientifically literate (but not specialist or follower) don't help. Hope someone can clarify because what I'm understanding qualitatively (not much either) is that mass alters "local vacuum density" and that makes either for more "vacuum plasma" to push on, or is it a difference in potentials to exploit ? See how clueless, can't even tell if equation 1 slide 56 is the starting hypothesis and then deriving form there, or if the rest is supposed to illuminate this hypothesis, or if we have some circular reasoning (well, there is some circularity in any successful theory, this can be just "self consistency", not a counter argument by itself), or if this is just a way of expressing in a different way of what we already know in mainstream physics like, you know, for instance naked particle vs dressed particle (and what is expressed as "affected vacuum fluctuation density" would be the "density of the dress") (not likely as this is specific to fields others than gravity while formula 1 is only about energy densities, isn't it ?)

So, naïvely I would say : if something more is linked to local mass_energy density (is that it rho m_local ?) how can you exploit it energetically as it is still a local minimum energy state in its own specificity. Not clear, a classical analogy would be : a liquid (surface of minimum energy) forms a meniscus close to the wall of a container, at this point the surface is higher (take a concave meniscus) than the rest of the surface. That don't make it possible to exploit this difference of height to generate energy as the surface is of minimal energy, given the wall of the container is there : it both makes possible the change of altitude of surface, and prevents that to be used for useful work. If one could instantly make the wall vanish, then this meniscus is no longer a minimum energy surface and work can be recovered, but not more than what it took to "make it vanish". Meaningless talk probably.

Equation 2 : ok so this is principle of equivalence, I guess we could expect the same magnitude as Hawking radiation (no ?), so a bit surprised that a mundane mass density like a dielectric (not even a neutron star) could make much difference with nothing. Let's proceed.

Next (still on slide 56)
Quote
The tools of MagnetoHydroDynamics (MHD) can be used to model this modified vacuum fluctuation density analogous to how conventional forms of electric propulsion model propellant behavior.
don't understand (trying) is that : MHD tools used to model the coupling of RF field with this denser vacuum ... ?

There I'm stuck for now.

If the other equations/slides bring something else as to why some better than 1/c thrust/power ratio can be obtained at all (however small, regardless of the fact that vacuum would be denser than usual in a capacitor) it didn't struck me.

Also, on a side note, the proposed mission profiles are calculated with good old Newtonian mechanics, from a given thrust/power ratio. So while it is interesting to discuss the equations deriving such ratio (or the simple possibility of such ratio > 1/c) from possible hypothesis, that shouldn't prevent anyone to draw conclusions of the ratio without resorting to such hypothesis/equations or making calculation in such formalism.


            exotic physics                    Newtonian
Hypothesis ---------------> thrust/power -----------------> result (real cheap energy)


Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 12:59 am
Why is that every time something like this appears that there is certain strand of belief online that they must have had these for years but kept them secret. It's a depressingly recurrent theme for cutting edge technology whatever the field and I don't know what it is says about scientific literacy in the public at large.

I'm not asking why or claiming that he's keeping it secret. I'm asking why a larger one, which would (I hope) help demonstrate that EM drive technology is a real thing, hasn't been built yet.


not sure, but considering Star Drive is a electric-engineer, I am certain he has a good explanation for why not.

for Mach Effect devices, I know they need piezo-electric materials and ceramics that are just too expensive for anyone without some good financial backup.

The Cannae thruster (which has among the lowest thrust force and the lowest specific force measured at NASA Eagleworks) has an (inexpensive) Teflon dielectric resonator.   The Paul March Woodward-Effect devices measurements at NASA Eagleworks showed significantly higher thrust and specific force than the Cannae device...
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 01:37 am

an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf)

In particular, I find the Math toward the end of the slide show  interesting.

Thanks @aero for bringing this up. I wish we would address slides 56 to 60 of this paper   :)

**** and I don't mean this as a criticism, the equations of Dr. White are scattered in several Power Point slide presentations, I have NOT been able to find them all contained in a single entire paper
I mean this constructively, the more we address Dr. White's equations, the more fair our assessment and also the better we will understand whether his explanations are plausible or not

...attempt,.....

Thanks for taking a stab at  it.  Now you have a better idea of what his model is. I'm trying to find the link for a presentation where Dr. White derived his calculation of what he calls the "local vacuum density" as the geometric mean of the local material density (which he calculates from the radius of the hydrogen atom nucleus and the mass of a proton to obtain the density of the hydrogen nucleus) and the quantum vacuum density.  I can no longer find that link using Google   :(.  I recall that Dr. White's calculation was based on a Mean Free Path argument...  In any case, you can see that Dr. White didn't just come up with a "local vacuum density" number to arbitrarily fit experimental results, but that he has at least a "back of the envelope" argument for it...  This "local vacuum density" is of course several orders of magnitude larger than the zero point energy.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 02:56 am

an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf)

In particular, I find the Math toward the end of the slide show  interesting.

Thanks @aero for bringing this up. I wish we would address slides 56 to 60 of this paper   :)

...

... at this level I just can do dimensional analysis ....

Most problems in Engineering were solved with non-dimensional analysis (think of heat transfer,  Aeronautical Engineering, etc.) and a slide-rule at a time that numerical computations were not available.  Nothing wrong with that  ;) .  And it is always good to have a very simplified physical model that abstracts the main features.

What is out of the ordinary here is that exotic physics (electron/positron pairs of virtual particles modeled as a  MagnetoHydrodynamics plasma) is involved here, but let's see where this leads...
Title: Re: EM Drive Developments
Post by: Stormbringer on 09/15/2014 03:03 am


B) NO Information gets out on top secret work.  None.  Nada.  At the time of the Manhattan Project you didn't have snapshots with small amounts of information.  You had nothing getting out.  The NASA Eagleworks 2013 update on the Boeing/DARPA device (look at the link) seems to be on a Yahoo server with the address xa.yimg.com. All of these are servers that host the graphic images of Yahoo pages (y=Yahoo + img=image).

hmmmm. In Dr whites earlier video i recall Dr white stating that his Q thruster experiments were farther along than his warp interferometry experiment but he could not discuss the former in detail because... he either said it was classified or else subject to secrecy due to NDA or something like that.

as to the Manhattan project several of the scientists on the team were giving data to the soviets for ideological reasons even before the project was finished. They feared America would become an unstoppable evil empire if they were the lone nuclear power.
Title: Re: EM Drive Developments
Post by: birchoff on 09/15/2014 04:07 am
@Rodal

I think the answer to your thrust descripancy between the Cannae and the Tapered Frustum  devices may be partly answered by the size of the dielectric. According to the pictures and comsol models in the paper the size of the dielectric in the Cannae device has to be much smaller than the die electric in the Tapered Frustum. My guess as to why Cannae has a smaller dielectric would be that the theory they presented at the conference considers the slots in the cavity to be the source of the thrust (you can either buy the paper from AIAA to get access to their theory, or leverage the way back machine here => http://web.archive.org/web/20140517034519/http://cannae.com/ (http://web.archive.org/web/20140517034519/http://cannae.com/), along with the patent descriptions here => https://www.google.com/?tbm=pts&gws_rd=ssl#tbm=pts&q=inassignee:%22Cannae+Llc%22 (https://www.google.com/?tbm=pts&gws_rd=ssl#tbm=pts&q=inassignee:%22Cannae+Llc%22)). Interestingly, since the NASA testing it looks like the inventor at Cannae has moved away from that theory of operation and is building new devices that in the companies words...

Quote
Inventor Guido Fetta has developed a 2nd technology that develops thrust without the use of on-board reaction mass.  This new technology uses RF interactions with a dielectrically loaded waveguide to produce thrust.  This new technology functions by a mechanism that is different from the Cannae Drive thrust mechanism.  Cannae LLC has patent pending status on a wide range of designs based on this new technology.
<<http://www.cannae.com/updates (http://www.cannae.com/updates)

As for your question about the thrust and specific force numbers reported in the Deck for Shawyer's EmDrive. It is my understanding from second and third hand information that while Dr. White originally attempted to replicate Shawyer's device, they failed to get positive results. I believe this is what was being referenced in the paper

Quote
We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust.
<< Pg 18, Anomalous Thrust Production From RF Test Device.

So if the information is accurate then its most likely that the numbers on slide 40 of that deck are coming from one of Shawyer's papers or the Chinese papers (I have yet to double check that).
Title: Re: EM Drive Developments
Post by: frobnicat on 09/15/2014 10:18 am
In that vein, I think it would be best to discuss the experiments without addressing any controversial physical explanation for the time being."

Maybe we could split another thread for "Theoretical aspects of space drives" ?

Sill thinking that, between theoretical speculations of stratophysics of the unknown, and down to earth practical experimental apparatus and results inquiries, it is important to address uncontroversial physics consequences of said results, regardless of specific theories. Even if the various propellentless thrusts results weren't guided by any kind of backing theory and had been stumbled on by chance, that wouldn't prevent us to use the effect to the fullest extent permitted by Newtonian laws.

Sorry I will shuffle a little bit the quotation order and select fragments for my dissertation
Quote
PS:  A Hall thruster's input power to thrust efficiency or specific thrust is around 0.05 N/kWe using today's commercially available thrusters.  Air breathing jet engines can have thrust efficiencies of up to ~75 N/kWe at take off, so assuming a 0.40N/kWe for our Copernicus Orbital calculations is not way out on a limb, and in fact is representative of the performance of my first two Mach-Lorentz Thrusters (MLT) that I built in 2003 and 2004 and reported on in my STAIF-2006 paper.

So those mission profiles are sold with the following hypothesis that :

- a thrust/power>>1/c effect is possible,it is independent of speed, without expelling mass (that is without spending more onboard mass than the equivalent mass_energy to power the system, negligible so far)

- approaching 1N/kW is possible/expected/has been measured already

- in this hypothesis "thrust" and "power" retain the meaning they usually have, the observed acceleration of a free floating spacecraft will be thrust/mass, the total energy used by the onboard generator will be the power integrated on time. Mission profiles are calculated with Newtonian dynamics. While backing theories can explain why previous hypothesis hold, one don't need to use those special formalisms to set up mission profiles, just plug in the thrust/power number into classical framework (that is Newtonian when speed<<c and total energy/c² << spacecraft's mass)

Am I wrong on any of that ? Are there any (acquired) speed corrections to the thrust/ratio used in the proposed mission profiles ?

Quote
BTW, I'm a little late is saying this, but tell Goat Guy that he needs to perform his energy conservation analysis in the 4D GRT formalism and not the flat space-time Newtonian version he's been using to date when performing M-E or Q-Thruster based momentum and energy conservation calculations.  Woodward's 2004 M-E derivation paper's appendix A can show what's needed here.

I'm not Goat Guy but what he said about the tremendous practical energy in/practical energy out leverage of the mission profiles seems sensible to me : the net useful result is "very cheap classical energy". If a theory can explain where this energy comes from and keep energy balance overall, great, but that is irrelevant as far as mission profiles are concerned. In what would the 4D GRT be necessary to derive the practical consequences of the effect, would it make any difference for mission profiles ?

Cheap classical useful energy is not shocking by itself, arguably a solar sail has an infinite thrust/power ratio from the standpoint of a spacecraft : net thrust with 0 power. And therefore we could devise some solar windmill that are "free" energy generators. Probably not practical.

Thing is : with the claimed(used in mission profiles) thrust/power ratios approaching 1N/kW we can devise very near practical energy generators, suffice to rotate the thruster at the rim of a rotor with a tangential speed a bit more than 1/ratio = 1km/s. Since there is no complex or moving parts in those thrusters it should be relatively straightforward, the RF generator could be mounted fixed, and give the power through a waveguide coaxial with the shaft. This is only a technological problem of high specific strength materials and maybe some (not enormous) tapering of supporting rotating arm section if a bit more 2km/s needed. If 0.5 chained efficiency of the electric dynamo on the shaft and the RF generator then 5km/s needed with 0.4N/kW to reach breakeven, hard but not impossible.

So the question is, and remains, why the results are not also sold on that possibility, should they hold and be classically interpreted for propulsion purpose, why would it be impossible/taboo to classically derive this incredibly useful consequence of "very cheap energy" generators?

The power/mass ratios might be near 10 W/kg (optimistically say with 1N/kW thruster, 100kg system, generating 1N at 3km/s, 3kW mechanical, 2.7 electric at dynamo, 2kW  used for 50% efficiency 1kW output RF generator, 700W net power breakeven, 7W/kg)
7W/kg is not much specific power but hey, it's free ! A spacecraft 200kg with a 100kg generator like that, and a thruster at 1N/kW would have acceleration of .7/200 = 3.5e-3 m/s², forever, for free.
That is about 100km/s a year, a bit short for interstellar but making roaming the suburbs a breeze.

Has this real possible and desirable consequence of the effect, good energy generators for space (and earth), been mentioned by the proponents of the effect, and if not why not ?

Quote
As for White's Q-Thrusters, energy & momentum conservation is observed by the fact that the vacuum derived propellant has an energy equivalent mass that does have a velocity less than c.  And just like the standard rocket equation, your rocket's maximum obtainable velocity is dependent on the maximum exhaust velocity of the Q-Thruster that is driven by all its local and perhaps gravitational field input energies.  Our current model for same indicates that these vacuum e/p pair like propellant velocities should be in the range of 10,000-to-10,000,000 m/s for the geometries and input power levels we've looked at to date, but of course only if our Q-Thruster model Excel sheet is correct. 

If I understand well, the energy you have to put in the thruster to get the thrust has a mass equivalent, and like for a photon rocket after some point of very very intense onboard power generation the mass of the spacecraft is depleting and therefore we have a rocket equation hence a "maximum" practical attainable speed. Is that it ?

Anyway, either the mission profiles at 0.4 N/kW and absolute (?) speeds < 100km/s are possible, and so is a near practical "cheap energy generator", or the generator is not possible because 0.4N/kW starts to decrease above ~2.5 km/s but then interesting mission profiles are no longer possible either.

Best
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 12:07 pm
@Rodal
I think the answer to your thrust descripancy between the Cannae and the Tapered Frustum  devices may be partly answered by the size of the dielectric. According to the pictures and comsol models in the paper the size of the dielectric in the Cannae device has to be much smaller than the die electric in the Tapered Frustum.

Well, the numbers I posted (I am now putting everything in uN, as people may not have noticed the difference between mN and uN, and I am adding the Woodward-Effect devices) (see slide 40 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf ):

Shawyer/SPR Ltd.'s microwave device:

THRUST =  16000 to 170000 uN
SPECIFIC FORCE = 0.02 to 0.4 N/kW

______________________________

Boeing/DARPA device:

THRUST =   20 to 110 uN 
SPECIFIC FORCE = 1 to 20 N/kW

______________________________

Cannae Testing:

THRUST =   40 uN
SPECIFIC FORCE:  0.0014 N/kW
______________________________

Tapered (Frustum) Cavity Testing: 

THRUST = 50 to 90 uN
SPECIFIC FORCE=  0.003 N/kW to 0.0054 N/kW

______________________________

(?)Woodward-Effect device tested in 2004: 

THRUST = 4000 uN
SPECIFIC FORCE=  0.4 N/kW

______________________________

Paul March Woodward-Effect device tested in 2005: 

THRUST = 3000 uN
SPECIFIC FORCE=  0.3 N/kW

______________________________
Show little difference between the performance of the Cannae and the Frustum (Tapered Cavity) devices when compared to the other devices: both of them have Specific Force numbers much lower than the Shawyer/SPR Ltd and Boeing/DARPA devices

and the performance of the Cannae and the Frustum (Tapered Cavity) devices  is also much inferior to the previous tests at NASA Eagleworks performed on the Paul March Woodward-Effect device.

If we have to ignore the very high thrust forces of the Shawyer/SPR Ltd because those numbers are untrustworthy (not from NASA), and if we have to ignore the very high specific force of the Boeing/DARPA device because its thrust force was not a rectangular pulse, but instead an impulse and hence not suitable for steady-state operation, the clear winner both in thrust force and specific force are the  Woodward-Effect devices, they have orders of magnitude greater thrust force and specific force than the lousy-performing Cannae and Frustum (Tapered Cavity) devices recently tested.

So, forget about Microwave Resonators and go back to Woodward-Effect devices ?
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 12:19 pm
@Rodal

.....

As for your question about the thrust and specific force numbers reported in the Deck for Shawyer's EmDrive. It is my understanding from second and third hand information that while Dr. White originally attempted to replicate Shawyer's device, they failed to get positive results. ...

So if the information is accurate then its most likely that the numbers on slide 40 of that deck are coming from one of Shawyer's papers or the Chinese papers (I have yet to double check that).

Thank you for checking this. 

I agree with your reasoning.  I am still not 100% sure though, because:

A) Dr. White writes in that slide that he will ignore the Chinese data, so why would he show the Chinese data when he writes that he is simultaneously going to ignore it?
and
B) If the Shawyer data is from experiments done at Shawyer or elsewhere (not at NASA), why show such NASA-unverified Shawyer -data mixed together in a deck of slides with actual NASA data for other devices?

Kind of confusing to me...
Title: Re: EM Drive Developments
Post by: Jossarian on 09/15/2014 01:13 pm
If we could use nuclear rockets, other choices would be availabe for our propulsion needs, but sadly the nuclear propulsion venue is not available to the US space program due to political issues we all know of, unless of course a fusion power breakthrough shows up on our doorsteps...

Here you go...
http://www.forbes.com/sites/jeffmcmahon/2014/01/04/doe-mentions-technology-behind-the-home-nuclear-reactor-in-funding-opportunity/
http://climate.nasa.gov/news/864/

Isn't NASA’s Langley Research Center working on LENR reactors already?

It is also possible to use something like this:
http://arxiv.org/abs/1305.3913v3
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/15/2014 01:15 pm
As someone said before and in agreement on the experimentalist side of things...
Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust?
We wouldn't need vacuum chambers or any nonsense.
Why not?

Why not?  Because...

...why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?

Seriously, this time:

The cost and difficulty of scaling to that degree is prohibitive.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 02:19 pm
This is the text for Paul March Woodward-Effect device tested in 2005:  (see slide 40 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf )


The test unit was run at 2.13 MHz, yielding an AC electric field of ~20kV/m, and an AC magnetic field of ~27 Gauss.

• Based on the input parameters, the QVPT thrust prediction was 0.63 mN [630 uN]
• The observed thrust was +/- 0.89 mN [890 uN]

The test unit was run at 3.8 MHz yielding an AC electric field of ~20kV/m, and an AC magnetic field of ~48 Gauss.

• Based on the input parameters, the QVPT thrust prediction was 2.79 mN  [2790 uN]
• The observed thrust was +4.91 to -1.96 mN  [+4910 uN to -1960 uN] as measured via a 4900 mN (500gf) load cell

As can be seen to the right, the thrust signal is very clear when the unit is excited.

~3 mN Thrust  [3000 uN]
Specific Force ~0.3N/kW

________________________________

Notice:

1) The Thrust force was NOT measured with NASA's inverted pendulum, but instead with a 4900 mN (500gf) load cell.   If you see Dr. Woodward's paper, you will see that Dr. Woodward abandoned initial (hanging) pendulum testing in favor of load cell testing, because he noticed that pendulum testing introduces inertial artifacts from the pendulum itself.  My opinion : this makes sense to me. 

2) There is excellent agreement (from an engineering viewpoint) between Dr. Woodward's prediction for thrust and the experimental measurements.

3) << the thrust signal is very clear when the unit is excited>>

4) Based on the tested numbers, I don't understand the emphasis on the (Cannae and Frustum Tapered-Cavity) Microwave devices as their performance is very lousy in comparison.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/15/2014 02:27 pm
As someone said before and in agreement on the experimentalist side of things...
Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust?
We wouldn't need vacuum chambers or any nonsense.
Why not?

Do we need to go to 100kW ? Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or no?

Ok, start at 1KW then 10KW then 100KW...
The point is its much easier (I think) to construct higher power devices than to detect low thrust levels.
If a 1KW device was to slide down an air-track then the world would change...

OK I completely agree with you and JohnFornaro on that.  Now,

Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or not?  Did Dr. White's lab test the Shawyer/SPR Ltd.'s device, yes or not?

Can someone in this forum answer that, please  :)?

The copper Truncated Frustrum thingy looks like Shawyer's device.  Glad that you agree with me, BTW.

It would be nice to read more of Rodal's analysis of the testing mechanism.

The theory of how this device works is changing.  Here's some forum history:

Quote
Quote

EM-Drive is not fake science. They have a WORKING prototype and are moving towards a flight test in 2009. www.emdrive.com. This uses actual physics and obeys all the convervation laws.

I am NOT impressed by this site.  It states that just like a laser ring gyro is a closed system and can measure rotation rate, this drive is a closed system that can produce force.  Newton and all have NO problem with a closed system measuring rotation rate.  No need to introduce Special Theory effects to explain this.  Explaining away the closed system problem by using the laser ring gyro as an analogy tells me these people are incorrect.

However I do hope I am wrong and they produce a really nice rocket engine someday.  I for one will not be investing my money in this technology.

Danny Deger

P.S.  Maybe there is some change of momentum of the photons that balances the change of momentum of the rocket.  This would make the device not violate the law of the conservation of momentum.

I took me a while to understand how it works. There is a basic property of a waveguide that describes how the group velocity of a wave changes as the size of the waveguide changes. For the em-drive it is this that creates the force imbalance on the end walls of the cavity. In terms of momentum, if there are two equal masses and the total momentum p=p1-p2 then p is non zero when the velocities of the particle colliding at each end of the waveguide differ. The slope of the walls of the cavity ensure the collisions with the walls along the length result in a nonlinear force ie: the differing group velocities along the length of the sloping cavity ensure the particles don't just bounce around inside the cavity canceling each others forces totally out. One uses the law of relativistic velocity addition to see that there is forward motion when the thruster is viewed by an outside observer (thus an open system).

To illustrate:

If one fires two opposing canons within a closed box the impact of the canonballs against the walls will cancel out to result in zero motion. If either the velocity or the mass of one of the balls changes en-route to the wall then the impacts will not cancel out and there will be motion. The trick then is to deal with the lost mass or velocity. It has to have gone somewhere.

From the point of view of momentum; The em-drive looks at the change in velocity whereas the woodward drive looks at the change in mass. The both deal with the imbalance in different ways. EM-drive uses the properties of waveguides and relativity whereas woodward's drive uses machian mass fluctuations and a rectifier.

When one accounts for the energy absorbed into the system to create the motion then one retains conversation of energy. Same for momentum.

So I think I understand. Took me a while but I think I'm there. And it is basic physics! It USES newton laws. It just needed a different perspective.


Nathan:

A major problem with Shawyer’s waveguide explanation is that his theoretical proof does not provide an explanation for the magnitude of the reaction forces reported.  Photon rockets of any stripe with only several hundred watts of input power can't generate thrusts measured in milli-Newtons.  Instead they can only produce pico to nano-Newtons of thrust from their local power supplies, unless they are also inadvertently tapping into a higher dimensional energy manifold as do Woodward's devices with the cosmologically derived gravinertial field. 

However, Shawyer first has to replicate his posted video experiment in a hard vacuum (<1x10-6 Torr) and get the same results, thus precluding possible ion wind or cooling fan generated thrusts before we worry too much about his proposed theoretical approach.  If he does get the same reported thrust in a vacuum though, then my bet is still on Sonny White's QVF explanation being more accurate than Shawyer’s.

BTW, as noted by GI-Thruster, I need to find the time and resources to replicate my Mach-2MHz experiment and/or exercise my new MLT-2009 test article in a hard vacuum, before we can take its results to be anything more than strongly suggestive that M-E based MLTs work as advertised.  Alas, that next step for me has proven problematic so far...

What does the device push upon?  Personally, I'm disregarding the "free energy" aspect of the device, and am more concerned with the conservation of momentum.

So what do you consider “substance” in regards to proving these observed M-E effects are REAL?  Supporting experimental data from two or more different sources used to be considered substantiating support, but apparently that is no longer the case in 2009.  So what will it take to prove the point to you and the rest of the skeptics in the world that the M-E or its QVF cousin is real and usable?

I am not a sceptic, I would be *happy* if someone will prove that 3rd law of Newton can be worked around.

It can be the case that the idea, being rather radical, does require verification by more than one team. Extraordinary claims do require extraordinary evidence, in this case, reproduction of the effect by multiple teams.

Do not assume that "they" (meaning scientific community) have ill intentions. No amount of complaining that "they" don't take it seriously would help. Ony more independent verifications will.

Firstly, please stop asserting that M-E gets 'around' Newtons third law any more than a game of tug-of-war does. The M-E reacts against the rest of the universe, period. While I understand thats a bit big of a concept for some folks, honestly though, it shouldn't be for anybody who has moved beyond the idea that anything outside our solar system is just little light bulbs on a big sphere.

By what mechanism is it reacting against the rest of the universe?  Why do other devices not react with the rest of the universe like this?  Why is this one special?  How can it instantaneously signal the rest of the universe to react?  Saying it is so doesn't make it so.

I'm not explaining anything.  I'm trying to understand the concept here.  My earlier post about how the non-exhaustive list (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255287#msg1255287) simply does not serve to explain the theory still holds true.

Every year since around 2009, the theoretical rabbit hole of explanation about how this device works gets deeper and deeper, and thrust levels do not appear to be rising.

If there's a skunk works somewhere working on this, and it is Top Secret (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255303#msg1255303) then so be it.

Just for more reading, as well as an illustration of the Truncated Frustrum thingy.  The Chinese have expressed interest in this technology, and seem willing to invest:

http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=1898

http://blog.wired.com/defense/2008/09/chinese-buildin.html

An earlier explanation of the EmDrive suggested that "group velocity" was an operating principle. From my post on that Propellantless Propulsion thread on April 21, 2009, 03:19:58 PM:

IAC- 08 – C4.4.7.  which I’ll call “The Theory Paper”.

Group velocity is the speed with which the modulation of the wave propagates through space.  It is not the speed which any particles propagate. It is here that the paper falls apart for me, and is precisely the point in the cannonball analogy above where the analogy falls apart.  All of the cannonballs’ momentii (if that’s the word) will cancel out, unless the mass of a cannonball changes.  Then the analogy can propel itself forward.  But there’s no explanation of what it is that changes about the cannonballs to provide momentum.

Group velocity is dw/dk, where w is the wave’s angular frequency and k is the wave number.  I don’t see how this affects momentum.

In blazotron’s analysis of the theory paper, he states: “Then [Shawyer] states, completely without support, that the force imparted by a wave with group velocity vg is 2nhfA*(vg/c).  Nowhere in the text is it explained why we should be using the group velocity of the wave to calculate force.”  I think blazeotron is somewhat incorrect in stating where in the text is this explained.  The author alludes to:

CULLEN A.L. ‘Absolute Power Measurements at Microwave Frequencies’ IEE proceedings Vol 99 Part IV 1952

Thanks to MikeGi:

More on Shawyer:

http://www.assassinationscience.com/johncostella/shawyerfraud.pdf

Note how Shawyer's "Theory" original paper:
http://www.newscientist.com/data/images/ns/av/shawyertheory.pdf

Differs from the "Theory" paper now on his website:

http://www.emdrive.com/theorypaper9-4.pdf

Thanks to my digging:

http://www.rexresearch.com/shawyer/shawyer.htm

http://www.rocketeers.co.uk/?q=node/330

EmDrive at work:

http://www.youtube.com/watch?v=57q3_aRiUXs

See also here:

http://forum.nasaspaceflight.com/index.php?topic=14423.0

Thanks to 93143:

http://www.emdrive.com/yang-juan-paper-2012.pdf

http://forum.nasaspaceflight.com/index.php?topic=13020.msg978642#msg978642

Finally:

John - You're grasping at straws. The topic is Propellantless Field Propulsion and application. The test stand has no bearing on the topic beyond giving assurances that the thrust measurements were accurately made. Any good test stand will do, even a pendulum.

Aero: ...

The common wisdom is that EM drive does not work.  In the case of Woodward's work, and probably Shawyer's as well, the test stand is almost as important as the tested device itself, since the expected forces are thought to be very low in the experiments demonstrated.

Woodward and Paul March have gone to great lengths to account for spurious outside signals, and even now, can barely ascertain the output of his device from noise.

A pendulum will most assuredly not work.  ...  The measurement of the forces is key, until such time as they float one of these devices out on the conference room table. ...

The test stand is very important.  If I might repeat myself:  It would be nice to read more of Rodal's analysis of the testing mechanism.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 02:47 pm
The test stand is very important.  If I might repeat myself:  It would be nice to read more of Rodal's analysis of the testing mechanism.

@JohnFornaro

I completely agree with your statement <<The test stand is very important. >>. There are pendulum dynamic forces to take into account, as well as nonlinear coupling between swinging and torsional modes of oscillation.  I started to discuss this in detail but the thread got deviated into controversial-theoretical explanations.  Paul March was forthcoming with data.  My last post dealing with the test stand, I made some calculations (stiffness and natural frequency of swinging mode) based on my interpretation and I asked for confirmation.  There have been so many posts dealing with controversial-theoretical explanations that that particular post got buried  :).  Perhaps I should re-post it. 

My plan is the following: once Paul March has a chance to look at it, and to verify my understanding, then I can proceed to show my transformation of axes (rigid-body axes for the drive supported on the inverted pendulum compared to the fixed suport axes located at the bottom support of the inverted pendulum arm), and then my computation of a Lagrangian, and then the resulting equations of motion (showing coupling of torsion with swinging modes, and parasitic motions) from differentiating the Lagrangian....
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 03:24 pm

Quote

...Newton and all have NO problem with a closed system measuring rotation rate.  ...
Danny Deger


Excellent point by Danny.  I agree.  Feynman has a trick question regarding conservation of momentum (on the rotational effect of an electromagnetic force) on his Lectures on Physics classic.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 03:30 pm
To put this in fewer words:

If the drive's support platform (sitting on the inverted pendulum) does not stay horizontal when the inverted pendulum arm swings off-center, then this might be a problem, as it leads to coupling of swinging and torsional modes, and therefore to parasitic modes.  That's why Prof. Martinez-Sanchez at MIT designed (with students for their S.M. theses) his inverted pendulum's stand to stay horizontal at all times, even for swinging off-center motion of the inverted pendulum arm.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 05:50 pm
Referring to the following Paul March's article http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=31119.0;attach=496011

It is clear that

A) the "2004 Test Article" and the "2005 Test Campaign" referred to in slide 40 of Dr. White's presentation http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf ) are exactly the same as Paul March's tested devices in 2004 and 2005 in (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=31119.0;attach=496011)

B) the "2004 Test Article" and the "2005 Test Campaign" referred to in slide 40 of Dr. White's presentation http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf ) were NOT tested in Dr. White's NASA inverted torsion pendulum.  Instead they were tested by Paul March using a load cell.

Since it also appears that the Shawyer/SPR Ltd. data labeled as "Microwave Thruster Device" in slide 40 of Dr. White's presentation http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf ) were NOT tested in Dr. White's NASA inverted torsion pendulum, but instead they were tested elsewhere, we must separate the performance of devices tested elsewhere from those tested with Dr. White's NASA inverted torsion pendulum as follows:

Experimental data not obtained using Dr. White's NASA inverted torsion pendulum

______________________________

Shawyer/SPR Ltd.'s microwave device:

THRUST =  16000 to 170000 uN
SPECIFIC FORCE = 0.02 to 0.4 N/kW

______________________________

Paul March Woodward-Effect device tested in 2004:   

THRUST = 4000 uN
SPECIFIC FORCE=  0.4 N/kW

______________________________

Paul March Woodward-Effect device tested in 2005: 

THRUST = 3000 uN
SPECIFIC FORCE=  0.3 N/kW

______________________________
******************************
Experimental data obtained using Dr. White's NASA inverted torsion pendulum


Boeing/DARPA device:

THRUST =   20 to 110 uN 
SPECIFIC FORCE = 1 to 20 N/kW

______________________________

Cannae Testing:

THRUST =   40 uN
SPECIFIC FORCE:  0.0014 N/kW
______________________________

Tapered (Frustum) Cavity Testing: 

THRUST = 50 to 90 uN
SPECIFIC FORCE=  0.003 N/kW to 0.0054 N/kW

______________________________

It is evident from the above:

A) The thrust force measurements performed elsewhere are 33 to 8500 times greater than the thrust measurements using Dr. White's inverted torsion pendulum experiments.

B) It is interesting that different devices (Boeing/DARPA compared to the microwave devices) although they have specific forces differing by a large factor of 1000 times, have approximately the same thrust force measurements in Dr. White's inverted torsion pendulum.

If we have to ignore the very high thrust forces of the Shawyer/SPR Ltd because those numbers are untrustworthy (not from NASA), and if we have to ignore the very high specific force of the Boeing/DARPA device because its thrust force was not a rectangular pulse, but instead an impulse and hence not suitable for steady-state operation, the clear winner both in thrust force and specific force are the  Woodward-Effect devices, they have orders of magnitude greater thrust force and specific force than the lousy-performing Cannae and Frustum (Tapered Cavity) devices recently tested.

However:

Paul March's Woodward-Effect devices were tested in a completely different set-up (using a load cell instead of an inverted torsion pendulum).
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 05:59 pm
a riddle wrapped in a mystery inside an enigma

Since Paul March's Woodward-Effect tests show thrust forces and specific forces two orders of magnitude larger than those measured for the Cannae and the Frustum (Tapered Cavity) microwave devices,

Why haven't  Paul March's Woodward-Effect devices been tested in NASA/Dr. White's Eagleworks inverted torque pendulum and reported?

Wouldn't they have served as an independent control purpose of the measurements?  It would have been helpful to have the same device (Paul March's) tested in two different testing set-ups (in inverted torsion pendulum to compare with the previous load cell measurements )
Title: Re: EM Drive Developments
Post by: aero on 09/15/2014 06:07 pm
Quote
Paul March's Woodward-Effect devices were tested in a completely different set-up (using a load cell instead of an inverted torsion pendulum).

Maybe Paul March would test the Tapered (Frustum) Cavity using his set-up. That should also work to provide valid comparison between the two devices.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 06:49 pm
Quote
Paul March's Woodward-Effect devices were tested in a completely different set-up (using a load cell instead of an inverted torsion pendulum).

Maybe Paul March would test the Tapered (Frustum) Cavity using his set-up. That should also work to provide valid comparison between the two devices.

There is also a need to verify the reliability of the much publicized measurements already conducted with NASA's Eagleworks inverted torsion pendulum.  A NASA measurement carries a prestige (in the media) much higher than a measurement conducted at other places.  Three different devices (Boeing/DARPA, Cannae and Frustum), that have specific forces differing by a factor of 1000 give approximately the same experimental measurement range of thrust force.  A control is needed.  Paul March's previously load-cell-tested Woodward-Effect devices would serve as such a control for the thrust measurements.   If Paul March's measurements would be independently verified at NASA that would also carry significant prestige for Dr. Woodward's long-running efforts.
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 09/15/2014 06:56 pm

Why haven't  Paul March's Woodward-Effect devices been tested in NASA/Dr. White's Eagleworks inverted torque pendulum and reported?

@Rodal: My feeling is that you try to find too much meaning in this whole thing. After all, there is no scientific or engineering breakthrough described in the Dr White paper, just a report on some exotic experimentations with anomalous results. I see it as some "food for thought" paper. Indeed as Paul March said, there is a "pay the bills" aspect intended for NASA managers and certainly not for scientists. This gives a specific style to the writing, which you would not find in a more traditionaly formated paper. Every organisation has its own culture and quirks.

If people think there is some ongoing conspiracy or that scientific breakthrough about interstellar travel has been achieved, it's entirely different topics from EMDrive purpose (or btw Cannae) which aims only as replacing auxiliary propulsion systems on satellites.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/15/2014 07:02 pm
If people think there is some ongoing conspiracy or that scientific breakthrough about interstellar travel has been achieved, it's entirely different topics from EMDrive purpose (or btw Cannae) which aims only as replacing auxiliary propulsion systems on satellites.

You can't separate replacing auxiliary propulsion in satellites and interstellar travel; imparting delta-V without consuming/expelling reaction mass opens up the possibility of continuous acceleration in steady state operation.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 07:09 pm

Why haven't  Paul March's Woodward-Effect devices been tested in NASA/Dr. White's Eagleworks inverted torque pendulum and reported?

@Rodal: My feeling is that you try to find too much meaning in this whole thing. After all, there is no scientific or engineering breakthrough described in the Dr White paper, just a report on some exotic experimentations with anomalous results. I see it as some "food for thought" paper. Indeed as Paul March said, there is a "pay the bills" aspect intended for NASA managers and certainly not for scientists. This gives a specific style to the writing, which you would not find in a more traditionaly formated paper. Every organisation has its own culture and quirks.

...

@JPLeRouzic

There is not just one paper. 

There is a series of papers describing experimental results, in several countries, over at least two decades, as I have been discussing .

A) There is a claim that there can be rocket propulsion produced without on-board propellant and without an outside force propelling it (i.e. solar propulsion, electrodynamic tethers, etc.)

B) Furthermore, unconventional physics are proposed as an explanation (1) [Dr. White] a MagnetoHydroDynamics model for the quantum vacuum, 2) [Prof. Woodward] an unconventional Mach effect resulting in an “impulse” mass transient term and a second always-negative “wormhole” mass transient term, or 3) [Prof. Brito] a Minkowski instead of an Abraham stress tensor explanation without addressing "hidden momentum" (to name three different explanations that have been proposed).

I find those claims interesting, perplexing and worth investigating.  If you are not interested in such an investigation, and you are not interested in the other papers, you are free to pursue your own interests and/or "quirks" :)

Title: Re: EM Drive Developments
Post by: wembley on 09/15/2014 07:18 pm
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive (http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive)

I have been trying to find out whether some of the tests were preformed in a vacuum. From the paper, it sounds as though some of them were not -- but why have the detailed description of the evacuation process if none of them were? Can anyone shed any light?

Also, my understanding is that this technology could fit on a cubesat, presumably that would be a fairly cheap test?
Title: Re: EM Drive Developments
Post by: wembley on 09/15/2014 07:23 pm
I, for one, am glad if the NASA team's test results announcement has created a flutter. At least this will encourage more experts to get involved in coming up with either a definitive proof or disproof on this matter. At least one way or the other, the matter can then be settled.

It's already considered settled by mainstream science: there is nothing there.  Mainstream scientists have already looked into the EmDrive years ago and convinced themselves it doesn't work. 

Do you have any details of mainstream scientists looking into it? I've been following the EmDrive some years and can't find any evidence of this -- not even the results of Boeing's tests on it in 2009.  (Rumoured to be positive, but only a rumour)

The only mainstream science I've seen on it is the work by Jan Yuan and co, and that all seems to be positive. Mainstream scientists have certainly dimissed it, but I don't know if they've looked at it.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 07:24 pm
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive (http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive)

I have been trying to find out whether some of the tests were preformed in a vacuum. From the paper, it sounds as though some of them were not -- but why have the detailed description of the evacuation process if none of them were? Can anyone shed any light?

Also, my understanding is that this technology could fit on a cubesat, presumably that would be a fairly cheap test?

Hi,

The Wired UK  article was very confusing to me when I first saw it weeks ago.  The Wired UK staff should have done a better job.  It gives the impression that some of the NASA "Anomalous thrust ..." experiments were conducted inside a vacuum chamber in a partial vacuum:

<<the full report describes tests in which turbo vacuum pumps were used to evacuate the test chamber to a pressure of five millionths of a Torr, or about a hundred-millionth of normal atmospheric pressure.>> WRONG !


These particular tests (the reported NASA Cannae and Frustum tests) were NOT conducted in a vacuum. They were conducted at ambient pressure.

The NASA authors state in the paper that none of these tests (reported in the NASA "Anomalous thrust ..." paper ) were conducted in a vacuum because they realized that the electrolytic capacitors they had would not work in a vacuum.

Dr. Woodward conducted some of his tests in a vacuum (NOT at a NASA facility).

_______________________________

<<Also, my understanding is that this technology could fit on a cubesat, presumably that would be a fairly cheap test?>>

It would cost several millions of dollars at a minimum (not cheap for me  :)    but cheaper than it would have cost decades ago).  Also, whether these devices are ready for scale-up and testing in space is a debatable subject that is being debated in this thread...
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 09/15/2014 08:29 pm

A) There is a claim that there can be rocket propulsion produced without on-board propellant and without an outside force propelling it (i.e. solar propulsion, electrodynamic tethers, etc.)


That's not extraordinary, as you mention an electric tether does this. Are you sure there is nothing similar at work in EMDrive and others? There are many perfectly classical explanations for those experiments.
What is interesting is when an experimentation is reproducible and I don't see this here.

Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/15/2014 08:34 pm
Its been said that scaling a device up beyond 10s of Watts to 10s of KW would be prohibitively expensive and difficult.
This seems to be in the realm of high power radar and such. I.e COTS
So, sure it would cost a few $. But it could settle this debate once and for all. Think of the payoff!
Can anyone put forward a reasoned argument why high power devices haven't been made and tested?
Many thanks.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/15/2014 08:38 pm
again, considering Paul March (Stardrive) is an electric engineer AND is working on the QThruster, he can probably answer that  particular issue better than anyone on the planet.

I think there is not much sense in speculating on an issue which is actually the specialty of Paul March. Maybe you guys can send PMs or emails to him asking about that?
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 08:49 pm

A) There is a claim that there can be rocket propulsion produced without on-board propellant and without an outside force propelling it (i.e. solar propulsion, electrodynamic tethers, etc.)


That's not extraordinary, as you mention an electric tether does this. Are you sure there is nothing similar at work in EMDrive and others? There are many perfectly classical explanations for those experiments.
What is interesting is when an experimentation is reproducible and I don't see this here.

Yes, the three proposed explanations (from Dr.White, Prof. Woodward and Prof. Brito) I mentioned are extraordinary.
An electrodynamic tether is conventional physics. 

You claim <<There are many perfectly classical explanations for those experiments>> but you fail to propose a single classical explanation.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/15/2014 08:49 pm
again, considering Paul March (Stardrive) is an electric engineer AND is working on the QThruster, he can probably answer that  particular issue better than anyone on the planet.

I think there is not much sense in speculating on an issue which is actually the specialty of Paul March. Maybe you guys can send PMs or emails to him asking about that?
Presuming you are replying to my post...
What speculation? It is a direct and simple question. It is relevant to the thread and enquring minds need to know.
No PM's or emails needed at this point methinks.
There is probably a simple answer. I got one previously (Too expensive/difficult) that I dispute.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/15/2014 10:45 pm
@IslandPlaya :
Presumably also because higher power means stronger side effects. As already stated (was it John?) proving and studying an effect is about signal/noise ratio, not about absolute signal magnitude, and there is no reason to believe that the higher power and heavier system would improve enough SNR to be worth at this stage and given the credits ? By noise I'm including all spurious known and unknown classical effects that could mask or distort or mimic the studied effect in the experimental system.

Looks like, so far, effect relative magnitude (thrust/power) is not scaling with overall size or power, maybe we could check Dr Rodal's useful compilation of values to put that into perspective. The EM density on the other hand could be important for the thrust/power, but it won't need bigger apparatus either as it's a ratio of power to volume. Also the frequency used fixes a natural yardstick, the wavelength, there is no guarantee that a bigger cavity with more nodes of standing wave in it would work the same (at a given microwave frequency). Scaling without disturbing this aspect (and keeping the same freqs) might mean putting many identical small cavities in parallel, not a single bigger one.

Personally I would be much more interested and impressed to see a system with the thruster mounted on a freely rotating arm in a rotationally symmetric chamber (vertical shaft at same axis of a cylindrical chamber) and have it accelerate, even if not in a vacuum : is it still thrusting, how fast... ? Surely this is doable for the devices with the higher thrust/power ratio (not at uN but at mN), maybe not with a shaft but maybe just floating on liquid (liquid metal if low pressure need be). All explanations (of classical effect masquerading as the effect) requiring volumetric changes with the move of the device (pressure effects pushing between the chamber and the moving parts for instance) could be checked. And also this would be a first step toward that (to me) very mesmerizing possibility of an energy generator based on the effect.
Title: Re: EM Drive Developments
Post by: abuzuzu on 09/15/2014 11:07 pm
Islandplaya

I slightly know several of the Mach and EM effect experimenters.
 
These experiments, even the NASA sponsored experiments, are pretty much funded out of pocket by the experimenters.  A couple hundred watts of microwave power does not come cheap.  Add to that the microwave power source must operate in a vacuum- cooling is a big big problem -- and the entire experimental apparatus must mass less then the maximum allowed suspended mass limit of the precision force balance.  This is bare-bones shoestring and sealing wax experimentation.  Even so the experiments have yielded very suggestive ( my judgement of the value of the results) evidence of something unusual and potentially useful.

I agree it is time for someone or some agency to throw a significant chunk of change at these guys ( and gals - Hat tip to Heidi) and see if these effects are real or not.  Till then progress will be slow and uneven.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/15/2014 11:08 pm
...this would be a first step toward that (to me) very mesmerizing possibility of an energy generator based on the effect.

I hate to burst your bubble, but electromagnetic thrust can't be a real phenomenon and a "free energy" device at the same time.

If EM drives are real, building a generator out of an EM drive would be no different than using an electric fan to drive a wind power generator.
Title: Re: EM Drive Developments
Post by: Rodal on 09/15/2014 11:10 pm
@IslandPlaya :
Presumably also because higher power means stronger side effects. As already stated (was it John?) ....And also this would be a first step toward that (to me) very mesmerizing possibility of an energy generator based on the effect.

Right on ! 

Mesmerizing is the right word...(if this would work as proposed)...

[@frobnicat please add me to the list of those (John, etc.) who think you are brilliant in picking your choice of words  :) ]

Here is yet another paper, this time using Prof. Woodward's explanation ( http://arxiv.org/ftp/gr-qc/papers/0102/0102002.pdf  ), where the author realizes that:

<<If experiment will succeed, this opens the possibility to realize new kind of devices for energy production and space transportation>>

but ...

"Only entropy comes easy."
Anton Chekhov
Title: Re: EM Drive Developments
Post by: aceshigh on 09/15/2014 11:24 pm
again, considering Paul March (Stardrive) is an electric engineer AND is working on the QThruster, he can probably answer that  particular issue better than anyone on the planet.

I think there is not much sense in speculating on an issue which is actually the specialty of Paul March. Maybe you guys can send PMs or emails to him asking about that?
Presuming you are replying to my post...
What speculation? It is a direct and simple question. It is relevant to the thread and enquring minds need to know.

yes, I was replying to your post, but I was not saying you were speculating, I was saying that your direct and simple question would lead to speculations (from everyone else), which in MY humble (and maybe wrong opinion) would lead to a lot of posts that in the end could be dismantled with a single post by Paul March, since he is an electrical engineer working at the QThrusters and therefore could answer in 2 lines what we would speculate in 4 pages.

Now, I would prefer to speculate on this subject AFTER Paul March would answer it, so if he gives a reason for not being able to increase the power, people could disagree with him or give opinions on what could be done, whatever.

I completely agree with you that it IS relevant to this thread and that we all want to know. My point was not that the question should not be asked, but that I felt it would be better to ask the question to the person who knows the precise answer.


Quote
There is probably a simple answer. I got one previously (Too expensive/difficult) that I dispute.

EXACTLY. There is probably a simple answer! And Paul March (Stardrive) knows it. The answers you got before (too expensive, difficult) were SPECULATIONS, not answers. And you did not like those speculations.

Therefore I don´t know why you are disagreeing with me, when I exactly told you that you should get the simple answer directly from Paul March, instead of asking us, since all we can give you are speculations that will not satisfy you.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/15/2014 11:26 pm
Anyway, let me just post the answer Gi-Thruster gave to my inquiry at Talk Polywell forums about the question of increasing power in ME-Devices and if it was related to Mach Effect devices by Woodward and their difficulty of scaling up due to money constraints.

Quote from: GiThruster
I would never pretend to speak for Paul, but I can relate to you what his positions have been in the past. Last I heard, he was still maintaining he believed that Sonny's QVF model and Jim's M-E model were opposite sides of the same coin, despite Jim, Sonny and myself keep arguing this cannot be true. As result, paul's interest was in low-k materials that can be run at high frequencies since these low k materials don't suffer the same non-linearities and other troubles most high k materials have.

I doubt the trouble is lack of materials. I think Eagle has been remarkably productive, and I have little complaint there. Scaling up a thruster to Newtons of force just to scale it up is not useful at this point. What you want are high figures of merit (FOM's) in thrust to mass and thrust to power. You can alway build arrays of thruster later on if you get decent FOM's.

I am still on record that I don't trust the data coming from Eagle, but I'd just note that it the rumors are true and three more NASA centers are going to jump into the fray and start testing, we'll have real answers in the next year or two. Stennis already has a balance, so they could do validation studies pretty quickly. NASA has remarkable resources. They just need to be properly tasked.

I would just note though, that for a commercial grade M-E thruster, you really do want a Colossal Dielectric Constant (CDC) material that maintains its constant up into very high frequencies. Paul wasn't looking at that stuff despite I did recommend some to him.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/16/2014 12:05 am
...this would be a first step toward that (to me) very mesmerizing possibility of an energy generator based on the effect.

I hate to burst your bubble, but electromagnetic thrust can't be a real phenomenon and a "free energy" device at the same time.

If EM drives are real, building a generator out of an EM drive would be no different than using an electric fan to drive a wind power generator.

I strongly object : given the hypothesis of velocity invariant thrust/power effect (with this ratio >> 1/c therefore neglecting the mass of energy... see photon rockets) then a "free energy" device is not only possible, it is compulsory.
Consider a mobile thrusting at a constant 1N with a constant 5km/s velocity on a track that recovers this mechanical power and convert it to electricity with an efficiency of 0.5 : 2.5 kWe. Now you divert 2kW of this recovered power to feed back the mobile, lets say with 0.5 efficiency (transmission...), so you have 1kW of power on the mobile to power a 1N/kW EM drive that keeps the mobile going. Rests 500W of net electrical output, free of charge.
The velocity invariance of the thrust at constant power implies that above a certain speed (precisely the inverse of the thrust/power ratio) relative to whatever reference frame you feel technologically comfortable to exchange power with the mobile, above that speed so you reach breakeven. I let you figure out where the energy comes from as seen from the cosmic horizon, but if the effect is anything like it says it is, then it can give unlimited energy for all practical purpose.

If you are implying that something can't be both a free energy generator and real, then you should consider that EM drives are not real (or not with a velocity invariant thrust/power), which I would tend to agree, though the energy might be conserved on a larger scale and that is not free energy after all (say, you are actively contributing at accelerating the demise of the Universe when running such device) in which case the effect could be valid (with velocity invariance) and be a good energy generator, not free but cheap.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/16/2014 12:21 am
...this would be a first step toward that (to me) very mesmerizing possibility of an energy generator based on the effect.

I hate to burst your bubble, but electromagnetic thrust can't be a real phenomenon and a "free energy" device at the same time.

If EM drives are real, building a generator out of an EM drive would be no different than using an electric fan to drive a wind power generator.

I strongly object : given the hypothesis of velocity invariant thrust/power effect (with this ratio >> 1/c therefore neglecting the mass of energy... see photon rockets) then a "free energy" device is not only possible, it is compulsory.
Consider a mobile thrusting at a constant 1N with a constant 5km/s velocity on a track that recovers this mechanical power and convert it to electricity with an efficiency of 0.5 : 2.5 kWe. Now you divert 2kW of this recovered power to feed back the mobile, lets say with 0.5 efficiency (transmission...), so you have 1kW of power on the mobile to power a 1N/kW EM drive that keeps the mobile going. Rests 500W of net electrical output, free of charge.
The velocity invariance of the thrust at constant power implies that above a certain speed (precisely the inverse of the thrust/power ratio) relative to whatever reference frame you feel technologically comfortable to exchange power with the mobile, above that speed so you reach breakeven. I let you figure out where the energy comes from as seen from the cosmic horizon, but if the effect is anything like it says it is, then it can give unlimited energy for all practical purpose.

If you are implying that something can't be both a free energy generator and real, then you should consider that EM drives are not real (or not with a velocity invariant thrust/power), which I would tend to agree, though the energy might be conserved on a larger scale and that is not free energy after all (say, you are actively contributing at accelerating the demise of the Universe when running such device) in which case the effect could be valid (with velocity invariance) and be a good energy generator, not free but cheap.

What?

Energy is used to impart any sort of acceleration and give the object momentum, and driving a generator would take away an imparted portion of its momentum. The losses of driving the generator in a thermodynamically sound system would be greater than the energy needed to keep the system in motion. EM drives do not change this, and it makes no difference how high your initial velocity was before you started using that momentum to drive a generator; your perpetual motion machine is going to slow down.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/16/2014 12:23 am
Anyway, let me just post the answer Gi-Thruster gave to my inquiry at Talk Polywell forums ...

Quote from: GiThruster
...I am still on record that I don't trust the data coming from Eagle,...

What does the "record" show? Specifically, what data doesn't he trust and why doesn't he trust the data?

Sorry Dr Rodal, but the question I asked at Talk Polywell forums was about increasing the power input. I posted his entire answer here, but dissecting his answer here and return your questions to that forum, and back and forth wouldn´t be viable. I also can´t invite him to post in this thread because he was banned long ago in this forum.

I think GiThruster had some strong disagreements with Dr White in the past and there may a bit more of ad hominem in his distrust of Dr White than he would admit. But if it´s important to you to check with him those particular parts of his answer, I would suggest you to ask directly with him at that forum.

I hope you understand there is a limit I am willing to go in playing messenger boy between Talk Polywell, NasaSpaceFlight Forum and NextBigFuture :D
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 12:36 am
Anyway, let me just post the answer Gi-Thruster gave to my inquiry at Talk Polywell forums ...

Quote from: GiThruster
...I am still on record that I don't trust the data coming from Eagle,...

What does the "record" show? Specifically, what data doesn't he trust and why doesn't he trust the data?

Sorry Dr Rodal, ...

<<the question I asked at Talk Polywell forums was about increasing the power input.>> OK, but he went off-topic by stating that he was <<still on record that [he] don't trust the data coming from Eagle,>> and I thought it fair to not let that charge stay unexplained.  Never mind, I used Google to search for his statements at Talk Polywell forums and I found out that his main objection to what he refers to as "Eagleworks tests" was how the results of the interferometer tests for distortion of space (http://en.wikipedia.org/wiki/White%E2%80%93Juday_warp-field_interferometer ) were stated.   Dr. White stated that the experimental results showed a vanishing but non-zero difference between charged and uncharged states after signal processing, but this difference remained inconclusive due to external interference and limits in  computational processing.  GiThruster's opinion in that forum was that the results were negative, period.  A subject off topic for this thread.  I didn't find anything he posted that adds further to what is already in the record on this thread.  Thanks
Title: Re: EM Drive Developments
Post by: MichaelRBrumm on 09/16/2014 12:37 am
...this would be a first step toward that (to me) very mesmerizing possibility of an energy generator based on the effect.

I hate to burst your bubble, but electromagnetic thrust can't be a real phenomenon and a "free energy" device at the same time.

If EM drives are real, building a generator out of an EM drive would be no different than using an electric fan to drive a wind power generator.

I think that rightly or wrongly, some people believe that these drives may leverage a previously untapped force of nature. In their view, it would be like energizing an electromagnet in the dynamo of a wind turbine to extract energy from the wind. It only seems like "free energy" to the layperson, because they don't take into account the increased entropy in the Sun needed to generate those winds.

Until further testing, I'm going to remain skeptical. However, it wouldn't be the first time we discovered a new source of energy.
Title: Re: EM Drive Developments
Post by: KelvinZero on 09/16/2014 12:54 am
I hate to burst your bubble, but electromagnetic thrust can't be a real phenomenon and a "free energy" device at the same time.

If EM drives are real, building a generator out of an EM drive would be no different than using an electric fan to drive a wind power generator.
Frobnicat is correct, but it is discussed in more detail here.

http://forum.nasaspaceflight.com/index.php?topic=35332.0

 (The whole thread is interesting in my opinion, but of course that would be the case ;) )

I also created that thread precisely so various propellantless propulsions schemes etc do not repeat these discussions on general physics that apply equally to all of them.

What should be discussed on this thread is the specific loophole exploited to get around the general issues. Several are brought up from time to time. Im not sure which one is claimed here or if there is a concensus on that.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/16/2014 01:06 am
I don't see how you're making the leap from an EM drive providing a constant force to an EM drive imparting a constant change in velocity. I can't see how an unknown mechanism for transforming electricity into kinetic energy in one direction necessitates a surplus of energy.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/16/2014 01:17 am
...
Consider a mobile thrusting at a constant 1N with a constant 5km/s velocity on a track that recovers this mechanical power and convert it to electricity with an efficiency of 0.5 : 2.5 kWe. Now you divert 2kW of this recovered power to feed back the mobile, lets say with 0.5 efficiency (transmission...), so you have 1kW of power on the mobile to power a 1N/kW EM drive that keeps the mobile going. Rests 500W of net electrical output, free of charge.
...

What?

Energy is used to impart any sort of acceleration and give the object momentum, and driving a generator would take away an imparted portion of its momentum. The losses of driving the generator in a thermodynamically sound system would be greater than the energy needed to keep the system in motion. EM drives do not change this, and it makes no difference how high your initial velocity was before you started using that momentum to drive a generator; your perpetual motion machine is going to slow down.

Then you say that the presence of a EM thruster makes a system thermodynamically unsound, and therefore impossible. I would tend to agree. My hypothetical perpetual motion machine (make the track circular for actual perpetuity) makes exactly the same hypothesis as the proponent to build up mission profiles : a given thrust/power figure, and Newtonian mechanics from there on. It is stationary (time invariant) as you can check step by step if you know classical mechanics (I do, so I'm rather confident there) :
no need to talk of acceleration or momentum or losing velocity as forces counteract exactly, on the axis of interest (the track) the mobile is subject to 2 opposing forces, 1N of thrust of the EM thruster (pushing on "the walls of reality", that's where the gained energy would come from if it were to be conserved overall as it would be, like, pushing on something that's conveniently always at 0 speed relative to you, whatever your velocity) and opposite 1N of the track's energy recovery system. The mobile sees two opposite equal forces, it keeps its speed exactly. Note that if the track were to have some friction losses, this could be included in the tracks recovery 1N opposite force : I'm taking ample margin by considering a 0.5 efficiency between the 5000*1 = 5kW raw mechanical power imparted by the mobile to the track and the recovered 2.5kW electric power output of the track "dynamo". The ground track system inputs 5kW mechanical, dissipates 2.5 kW as heat, and outputs 2.5kW electric, of which 500W to the benefit of the community, and 2kW in a wireless transmission system that dissipates 1kW as heat and allows the mobile to recover 1kW electric. The mobile electric system inputs 1kW, and outputs 1kW to the EM thruster, which by the EM thruster hypothesis gives from that the 1N thrust needed (and probably also some more heat).
If small instabilities were to make the mobile slow down a little bit, you would just have to take a little bit of the 500W excess back into the system to regulate. The system could as well diverge toward higher velocities, you just have to put a good regulation to stabilize on a given target velocity. Ample margin for that.

If you find flaw in the mechanics of this perpetual motion, please tell exactly where, because I see none. If it is still not making sense to you then consider the EM thruster hypothesis to be wrong, and forget about the propulsion applications.

If it were to make sense with a valid EM thruster hypothesis, this would imply very exotic physics indeed to keep an energy balance overall. There at the stress energy tensor of asymptotic space curvature and the gates of dark energy I shall stop.
Title: Re: EM Drive Developments
Post by: KelvinZero on 09/16/2014 01:21 am
I don't see how you're making the leap from an EM drive providing a constant force to an EM drive imparting a constant change in velocity. I can't see how an unknown mechanism for transforming electricity into kinetic energy in one direction necessitates a surplus of energy.
I think we should discuss it on that other thread. I won't mind if anyone bumps it ;)
http://forum.nasaspaceflight.com/index.php?topic=35332.0
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/16/2014 01:33 am
If you find flaw in the mechanics of this perpetual motion, please tell exactly where, because I see none. If it is still not making sense to you then consider the EM thruster hypothesis to be wrong, and forget about the propulsion applications.

First and foremost, can you derive the excess energy mathematically? How much input power are you using to impart 1 Newton of thrust, and what is the precise mathematical relationship you're using to generate even more power, start to finish, with your generator than was put in?
Title: Re: EM Drive Developments
Post by: Stormbringer on 09/16/2014 01:59 am
I just want to say that this discussion has brought together cites and sources that i would spend a life time trying to find and i would not have been able to find a tenth of it on my own. at first i had doubts about the thread but now it's invaluable. thanks everyone.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/16/2014 02:18 am
I just want to say that this discussion has brought together cites and sources that i would spend a life time trying to find and i would not have been able to find a tenth of it on my own. at first i had doubts about the thread but now it's invaluable. thanks everyone.

that´s exactly the reason I tried to bring GoatGuy here and also ask some questions at Talk Polywell and also invite Paul March to this topic. I am really glad at the result of this thread so far. Dr Rodal contributions are invaluable also! What a great new addition to the forum.
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/16/2014 03:14 am
If you find flaw in the mechanics of this perpetual motion, please tell exactly where, because I see none. If it is still not making sense to you then consider the EM thruster hypothesis to be wrong, and forget about the propulsion applications.

First and foremost, can you derive the excess energy mathematically? How much input power are you using to impart 1 Newton of thrust, and what is the precise mathematical relationship you're using to generate even more power, start to finish, with your generator than was put in?

Yes, the derivation, exact has been done here:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1254645#msg1254645

The derivation makes two distinct mathematically sound postulates:

That at V = 1/k meters per second, where k is the newtons per watt of the thruster, the amount of kinetic energy being imparted is the same as the energy invested.   This is the technical "break even" point.  Above V = 1/k, the amount of energy being created is

dE/dt = FV  and where F = P*k then
dE/dt = PkV and recalling that Pout = dE/dt, then
Pout = Pin kV

Now, just "eyeball it" qualitatively.  The break-even critical velocity is V = 1/k.  Just substituting that in:

Pout = Pin·k·(1/k) pretty obviously one can cancel the k's
Pout = Pin

Or, if you prefer, trying any multiple (R = ratio) of V = R/k leads to:

Pout = Pin·k·(R/k), where again we'll dispense with the 'k's cuz the cancel:
Pout = R·Pin

This was just a fancy way of saying the same thing as the previous equation, it being the special case where R = 1.000....  If R is greater than 1, then Pout is greater than Pin.  If it is less, then Pout is less than Pin.  The relationship is linear.

- - - - - - - -

The analysis of the perpetual motion machine aspect of this is very clear:  while the various wildly brilliant professional physicists here are discussing all nature of postulated tertiary physics, the real world continues to intervene.  When R is greater than 1, V = R/k demonstrates continuous increase in kinetic energy of the test bed, larger than power input during the interval.

GoatGuy
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/16/2014 03:19 am
...this would be a first step toward that (to me) very mesmerizing possibility of an energy generator based on the effect.

I hate to burst your bubble, but electromagnetic thrust can't be a real phenomenon and a "free energy" device at the same time.

If EM drives are real, building a generator out of an EM drive would be no different than using an electric fan to drive a wind power generator.

Maybe I should have responded to this first.  I can't say I hate to burst your rebuttal, but ... its wrong.

See my previous post, right above.  The math is concrete and incontrovertible.  It may be incomplete, which is what we're asking quantitatively sensitive mathematicians to debate.  Trust... between frobicat and myself, we have all the higher-math skyllz necessary to contribute to the mathematical debate.

GoatGuy
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/16/2014 03:56 am
I'll leave the math to you, then. However, without considerable evidence to the contrary, I'm going to treat the mathematical debate as an exercise in creative accounting. Free energy does not mix well with reality to date.
Title: Re: EM Drive Developments
Post by: Stormbringer on 09/16/2014 04:19 am
i may have a differing definition but there are all sorts of free energy sources.

yes they eventually run down. some in millions or billions of years; which is not trivial.

we don't do a thing to spark the sun. nor bust up unstable atoms. that energy is free by my definition.

if i drill a hole down deep and drop water down it and use the steam to turn a turbine or heat a thermoelectric converter it's free energy after it pays back my initial investments of time labor and materials.

there are free sources of energy available to us. bean counting the energy balance of a star does not make sense to me. bean counting or quibbling about the minutia of the situation is pretty pointless. the star is giving free energy. the radioactive matter is giving free energy. the geothermal well is giving me free energy. a wind mill or tidal rotor is giving me free energy.

yes all of these things obey conservation laws. all of these systems lose energy and order over time. but that is so trivial that it can be safely ignored for all practical purposes.

there may be other undiscovered reservoirs of energy that we can learn to tap doing so does not violate the laws of the universe.

to me free energy means taping an available source of energy such that sooner or later my own input is either trivial or not needed except for maintenance. It's not magick. it's not heresy. it's a fact of life and already happens in the technological world with the examples i provided above.

Title: Re: EM Drive Developments
Post by: aero on 09/16/2014 06:04 am
Free energy - Heat pumps. Much more heat or cooling provided than the heat energy value of the electricity used to operate them.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 09/16/2014 06:21 am
i may have a differing definition but there are all sorts of free energy sources.

yes they eventually run down. some in millions or billions of years; which is not trivial.

You're missing the whole point.  You do have a different definition of "free energy" than the standard definition.  Using it to mean something else just causes confusion.

There's a fundamental difference between free energy in the usual sense (i.e. energy can be created anywhere in any quantity without limit) and what you're talking about, which is energy that exists in particular environments already and can be harvested.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 09/16/2014 06:24 am
Free energy - Heat pumps. Much more heat or cooling provided than the heat energy value of the electricity used to operate them.

No.  Heat pumps can, in some circumstances (but not all) provide heating more efficiently than other options, like a furnace, but that's just efficiency, not free energy.  And cooling can, for practical purposes, only be done by heat pumps, so it doesn't even make sense to talk about "more cooling" than some alternative.
Title: Re: EM Drive Developments
Post by: wembley on 09/16/2014 06:48 am
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive (http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive)

I have been trying to find out whether some of the tests were preformed in a vacuum. From the paper, it sounds as though some of them were not -- but why have the detailed description of the evacuation process if none of them were? Can anyone shed any light?

Also, my understanding is that this technology could fit on a cubesat, presumably that would be a fairly cheap test?

Hi,

The Wired UK  article was very confusing to me when I first saw it weeks ago.  The Wired UK staff should have done a better job.  It gives the impression that some of the NASA "Anomalous thrust ..." experiments were conducted inside a vacuum chamber in a partial vacuum:

<<the full report describes tests in which turbo vacuum pumps were used to evacuate the test chamber to a pressure of five millionths of a Torr, or about a hundred-millionth of normal atmospheric pressure.>> WRONG !


These particular tests (the reported NASA Cannae and Frustum tests) were NOT conducted in a vacuum. They were conducted at ambient pressure.

The NASA authors state in the paper that none of these tests (reported in the NASA "Anomalous thrust ..." paper ) were conducted in a vacuum because they realized that the electrolytic capacitors they had would not work in a vacuum.

Dr. Woodward conducted some of his tests in a vacuum (NOT at a NASA facility).

_______________________________

<<Also, my understanding is that this technology could fit on a cubesat, presumably that would be a fairly cheap test?>>

It would cost several millions of dollars at a minimum (not cheap for me  :)    but cheaper than it would have cost decades ago).  Also, whether these devices are ready for scale-up and testing in space is a debatable subject that is being debated in this thread...


As author of the WIRED UK piece I take your point, but believe me, there were reasons ;)

Where does it say that NONE of them were in a vacuum(I know some weren't), and why does it describe the evacuation protocol?

Also a cubesat is only a kilo, so getting it up should be less than $100k, and the construction costs aren't that high...?
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/16/2014 07:27 am
Quote
Where does it say that NONE of them were in a vacuum(I know some weren't), and why does it describe the evacuation protocol?

You have to carefully read through the full paper before this becomes apparent.  Folks here spent something like a half a dozen pages on this thread figuring this out one tortured word at a time...and even then it took direct confirmation from one of the people on the team.  Short story, the team evacuated the chamber, and only then realized their capacitors would not function in a vacuum.   So the chamber was re-pressurized.   Same team member commented they now had hermetically sealed vacuum rated capacitors for the next test.

(if the paper had been clearly written in the first place this misconception would not have arisen.)

Quote
Also a cubesat is only a kilo, so getting it up should be less than $100k, and the construction costs aren't that high...?

Sounds like a good idea, once the next round of ground tests is completed.  (at least to me, but I'm just a fascinated spectator here).

Also need to decide just which version of this thing gets launched into space - appear to be two (?) three (?) competing (?) designs. 

The shape of the device (tapered) is important, so it wouldn't be a cube, but a quick Google search told me your cited price range is about right.   As research costs go, that's not much more than pocket change...for a person with deep pockets.  Maybe crowdsourcing?  I seem to remember reading of oddball fund drives that cough up comparable amounts of money.
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 11:55 am
......

As author of the WIRED UK piece I take your point, but believe me, there were reasons ;)

Where does it say that NONE of them were in a vacuum(I know some weren't), and why does it describe the evacuation protocol?

Also a cubesat is only a kilo, so getting it up should be less than $100k, and the construction costs aren't that high...?

The report ("Anomalous thrust ...") actually states (p.21):

<<Vacuum compatible RF amplifiers with power ranges of up to 125 watts will allow testing at vacuum conditions which was not possible using our current RF amplifiers due to the presence of electrolytic capacitors. >>  [Bold added for emphasis]

Nowhere in the report does it state that any of the tests were conducted in a vacuum.

The report describes the evacuation protocol they were planning to use once they obtain vacuum compatible RF amplifiers with power ranges of up to 125 watts.

I stand behind my opinion that it would cost several millions of dollars at a minimum to put a functional EM drive in orbit, and the fact that whether these devices are ready for scale-up and testing in space is a  debatable subject. 

We are even debating whether the measured thrust forces are spurious testing artifacts and whether it is even possible to have a rocket drive without on-board-propellant that doesn't rely on a known exterior force (known exterior propulsion forces as in solar propulsion, electrodynamic tethers, etc.) instead of "exotic physics" as the proposed explanations of "pumping the quantum vacuum" or forces due to "mass transient terms" resulting from instantaneous Mach effects from the rest of the universe.

Having said that, it will be interesting to hear what other people in this forum think.

The following information:

Experimental data not obtained using Dr. White's NASA inverted torsion pendulum

______________________________

Shawyer/SPR Ltd.'s microwave device:

THRUST =  16000 to 170000 uN
SPECIFIC FORCE = 0.02 to 0.4 N/kW

______________________________
******************************
Experimental data obtained using Dr. White's NASA inverted torsion pendulum in his latest report

____________________________

Cannae Testing:

THRUST =   40 uN
SPECIFIC FORCE:  0.0014 N/kW
______________________________

Tapered (Frustum) Cavity Testing: 

THRUST = 50 to 90 uN
SPECIFIC FORCE=  0.003 N/kW to 0.0054 N/kW

______________________________

shows that Shawyer/SPR Ltd.'s EM drive is claimed (with "measurements" performed elsewhere -not at NASA-)  to have a thrust force 2000 to 4000 times higher than the drives recently tested at NASA.

What information does WiredUK have in this regard?
Is Shawyer/SPR Ltd.'s EM drive going to go into orbit soon - at a cost less than $100k-?
Title: Re: EM Drive Developments
Post by: wembley on 09/16/2014 12:51 pm

shows that Shawyer/SPR Ltd.'s EM drive is claimed (with "measurements" performed elsewhere -not at NASA-)  to have a thrust force 2000 to 4000 times higher than the drives recently tested at NASA.

What information does WiredUK have in this regard?
Is Shawyer/SPR Ltd.'s EM drive going to go into orbit soon - at a cost less than $100k-?


I'm a freelance, but Wired UK have been about the only people who will accept articles on this for the last few years.

Unfortunately, Roger Shawyer seems to have been left on the sidelines on this one and SPR are not in a position to launch. I'm currently trying to find out what happened to the UK evaluation of his technology in 2009, but that seems to have been lost. He looks like being a pioneer whose work was taken up by others.

Cannae are certainly continuing their work and have previously discussed a Cubesat mission with a thruster producing 3 micronewtons -- note their website is back up again now in slightly altered form --
http://cannae.com//2-uncategorised/48-cubesat
There is no indication who they are partnering with, but we they have talked to various aerospace players previously.

Yang Juan's work is also progressing largely undercover, but does appear to be progressing. I wrote a piece about this for Aviation Week which should appear shortly. My guess would be they will be the first to launch, unless NASA decide to sieze the initiative. However, the lack of comments from NASA suggests that the agency do not have any great appetitie for it, but I would be interested to hear otherwise. The lack of public statements for a new development doesn't seem normal to me, but others may know better?

Title: Re: EM Drive Developments
Post by: JasonAW3 on 09/16/2014 01:08 pm
Out of curiosity,

     What sources of funding have White, et al. been using to fund this project?
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 01:15 pm
.
Cannae are certainly continuing their work and have previously discussed a Cubesat mission with a thruster producing 3 micronewtons -- note their website is back up again now in slightly altered form --
http://cannae.com//2-uncategorised/48-cubesat
There is no indication who they are partnering with, but we they have talked to various aerospace players previously.

According to the NASA report, the Cannae drive had the worst performance (in measured thrust force and specific force) of any drive measurement reported by NASA.  Furthermore, NASA testing showed that Cannae's slots made no difference, as NASA reported testing a Cannae device with no slots and NASA reported about the same performance.  This prompted John Baez and other scientists' negative reaction (see https://plus.google.com/117663015413546257905/posts/C7vx2G85kr4), with Baez stating << They tested a [Cannae with slots] device that was designed to work and one [Cannae without slots] that was designed not to work.  They both worked>>. 

Yang Juan's work is also progressing largely undercover, but does appear to be progressing. I wrote a piece about this for Aviation Week which should appear shortly. My guess would be they will be the first to launch, unless NASA decide to sieze the initiative. However, the lack of comments from NASA suggests that the agency do not have any great appetitie for it, but I would be interested to hear otherwise. The lack of public statements for a new development doesn't seem normal to me, but others may know better?

Do you have any recent information (or link) regarding any work of Yang Juan after the already reported (2010) paper [whose translation to English is freely available in Shawyer's site, see: http://www.emdrive.com/NWPU2010translation.pdf] showing their tests at the Chinese university ?

Please note that Yang Juan did not conduct the Chinese University reported tests in a vacuum chamber either.
Title: Re: EM Drive Developments
Post by: wembley on 09/16/2014 01:38 pm
.
Cannae are certainly continuing their work and have previously discussed a Cubesat mission with a thruster producing 3 micronewtons -- note their website is back up again now in slightly altered form --
http://cannae.com//2-uncategorised/48-cubesat
There is no indication who they are partnering with, but we they have talked to various aerospace players previously.

The Cannae drive had the worst performance (in measured thrust force and specific force) of any drive measurement reported at NASA.  Furthermore, NASA testing showed that Cannae's slots made no difference, as NASA reported testing a Cannae device with no slots and NASA reported about the same performance.  This prompted John Baez and other scientists' negative reaction (see https://plus.google.com/117663015413546257905/posts/C7vx2G85kr4), with Baez stating << They tested a [Cannae with slots] device that was designed to work and one [Cannae without slots] that was designed not to work.  They both worked>>. 

Yang Juan's work is also progressing largely undercover, but does appear to be progressing. I wrote a piece about this for Aviation Week which should appear shortly. My guess would be they will be the first to launch, unless NASA decide to sieze the initiative. However, the lack of comments from NASA suggests that the agency do not have any great appetitie for it, but I would be interested to hear otherwise. The lack of public statements for a new development doesn't seem normal to me, but others may know better?

Do you have any recent information (or link) regarding any work of Yang Juan after the already reported (2010) paper [whose translation to English is freely available in Shawyer's site, see: http://www.emdrive.com/NWPU2010translation.pdf] showing their tests at the Chinese university ?

Please note that Yang Juan did not conduct the Chinese University reported tests in a vacuum chamber either.

The point about the Cannae drive is not how much thrust it produced in the NASA test compared to other designs, but whether their 3 micronewton design is plausible. Because if they have backing, it will be built and  launched.

The 2012 Yang Juan paper (which is also on Shawyer's site ) is more important than the 2010 one, but there are a few others including a recent one I address in AvWeek.
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 01:41 pm

The 2012 Yang Juan paper (which is also on Shawyer's site ) is more important than the 2010 one, but there are a few others including a recent one I address in AvWeek.

OK, this is the link to the © 2012 Chinese Physical Society (Received June 9, 2011; revised manuscript received in October 25, 2011) paper by Yang Juan:  http://www.emdrive.com/yang-juan-paper-2012.pdf

also, (from what I can see) never tested in a vacuum

If my (admittedly cursory -I don't read Chinese and I have to interpret the translation to English) understanding of this paper, Yang Juan also used some kind of an inverted torsional pendulum to measure thrust.  The translation reads "balance" rather than "pendulum" though, but Fig. 3 looks like an inverted pendulum.

My understanding is that only rotational displacements (and hence torsional forces) were measured. 

The translation states:

<<Before the propellantless microwave thrusters work, the rigidity of flexible waveguide 9, and mass and position of counterweight 8 must be adjusted, so that the flexible waveguide moment of elastic force FflexL balances the gravitational moment of the mobile parts m1gΔx. At the same time, the mobile part’s line of gravity L1 and rotational axis L2 intersect.>>

Leading to their assumption that << At this time the rigidity and weight of the system components can be eliminated from the thrust measurement.>>  This assumption (and others in their paper) has to be analyzed.  I don't see an analysis of coupling of swinging modes with torsional modes and/or analysis of possible parasitic modes that are known to take place in inverted pendulums.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 01:45 pm
First, to Rodal:

Can you provide a schematic drawing with all the known dimensions of the various structural members, arrows of the measured forces along with the quantities of those forces, and other explanatory information in a graphic format?

I'll buy ya a Scotch.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 01:45 pm
Quote from: JPLeRouziclink=topic=29276.msg1255641#msg1255641 date=1410807361
If people think there is some ongoing conspiracy...

People don't. 

Please don't invoke the c-word as if it were a homonym of the term "skeptic".

It isn't.  That's one of the reasons we have dictionaries. 
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 01:46 pm
Also, my understanding is that this technology could fit on a cubesat, presumably that would be a fairly cheap test?

Look at the pictures.  The testing device is huge, plus it's tethered to cords. Still, if forces can be detected terrestrially, then a free body test in LEO would be an appropriate next step, in my mind.  I think that possible future experimental apparatus would require its own launch.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 01:47 pm
The Wired UK  article was very confusing to me ...

Wired is worse than the oracle, in that the articles never get vetted, and are rarely revisited.  They just sell headlines, that I can tell.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 01:48 pm
1) So, sure it would cost a few $. But it could settle this debate once and for all. Think of the payoff!

2) Can anyone put forward a reasoned argument why high power devices haven't been made and tested?

1)  Yahbut: you've just fallen into a trap:  You don't experiment on a new expensive propellantless trampoline drive on the sole basis of: "Think of how great it would be if it works!"

Again:

But (again) I'm against a "what if it works" scenario that wont go to all the inescapable consequences, when the consequences are on firm ground that couldn't possibly be overtaken by the hypothesis.

2) Because of the cost and difficulty combined with the reasonable doubt that such a scaling would even work.  Furthermore, there has been no hard theoretical evidence suggested by the proponents that the device could be scaled.  Heck.  We still don't know the size of the Teflon resonator yet!

One of the points I've made over and over is the incredible amount of electric power that goes into this device compared with the amount of thrust they think they see.

If ya wanna dispute this with me, first, you need to pull out your checkbook.  An ordinary "classical" checkbook will do.  Trust me.  I'll let ya know when I've had enough.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 01:48 pm
...building a generator out of an EM drive would be no different than using an electric fan to drive a wind power generator.

That's just not even wrong.  Everybody knows that you use an electric fan to power your sailboat.  Sheesh.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 01:48 pm
I hope you understand there is a limit I am willing to go in playing messenger boy between Talk Polywell, NasaSpaceFlight Forum and NextBigFuture.

No problemo.  NSF is the only forum worth this discussion.  There's too many tiresome hominems on the other ones.
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 01:49 pm

The 2012 Yang Juan paper...there are a few others including a recent one I address in AvWeek.

@Wembley

Can you please provide a link to the "recent paper by Yang Juan"(after the one in 2012) that you address in AvWeek ?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 01:49 pm
Frobnicat is correct, but it is discussed in more detail here.

http://forum.nasaspaceflight.com/index.php?topic=35332.0

Hah!  Have you heard about his Frobnicat Class III device?
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 01:54 pm
First, to Rodal:

Can you provide a schematic drawing with all the known dimensions of the various structural members, arrows of the measured forces along with the quantities of those forces, and other explanatory information in a graphic format?

I'll buy ya a Scotch.

 :)  Scotch. It's a tempting offer, but first I need to understand precisely how were these devices tested.   Waiting for Paul's response to my questions...


@Fornaro, chi va piano, va sano e va lontano
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/16/2014 02:00 pm
I'll leave the math to you, then. However, without considerable evidence to the contrary, I'm going to treat the mathematical debate as an exercise in creative accounting. Free energy does not mix well with reality to date.

... creative accounting ...  when I hear those two words, it inevitably means dishonest accounting in a cheeky way.  But I hope that you just didn't take the time to follow along with the algebra, or don't quite remember the main formulas of physics.  That's OK by me, RotoSequence ... it has taken me nearly a whole adult lifetime to become competent enough with the math-of-Physics so as to miss freeway exits, due to doing physics-math in my head.  Silly, I know, but it happens with regularity.

Without considerable evidence to the contrary... sounds to me like you're saying, "yes, well, whatever.  I still don't believe you've shown how this device can be a free-energy device.  If a lot of others were saying it and had good proof, I'd change my mind". 

I accept that, yet I also give you "the Physicists challenge".

Physics and Mathematics are utterly inseparable.  It has often been said, Physics is the mathematical modeling of the physical universe of things.  Physics has found predictive, descriptive math equations to describe basically every phenomenon that experimental scientists have discovered ... from quantum kinetics, to astronomical, from forces, and masses, energy and friction to materials science surface physics (semiconductors and chips!).  Physics describes accurately why hydrogen atoms glow at incredibly specific wavelengths when ionized, to better than 6 digits of precision, which is pretty remarkable considering no one has ever imaged a single hydrogen atom. 

The Physics Challenge is this:  to debate an assertion in Physics, it is necessary to describe the debated assertion in mathematical terms.  Words, phrases, similes, parables, examples are not sufficient, and actually detract from determining the outcome of the debate.  It is math, and specifically, symbolic math first that makes brief and debatable that which is in question. 

This is why I composed my argument as a mix of symbolic math, and supporting text.  Not everyone is familiar even with algebra, let alone trigonometry or calculus.  Fewer people still are "up" on the basic Newtonian physics formulae of our humanly tangible local space.  (The physics of Newton's environment is mathematically exactly as he defined and derived.  It is also the physics of the "macroscopic world", for things like spacecraft, EM-drive test-beds, Cannae drives, and so on.  Macroscopic, non-quantum. )

And until a Physicist pops up here, armed with better math to disprove the Newtonian physics conclusion inside the realm of our tangible physics environment, the assertions I made will continue to show that at a velocity above 1/k, all force-making machines produce more kinetic power than the electrical, chemical, nuclear or whatever else power that the machine uses to create the force it produces.

That is a very powerful assertion, right there.  It does not depend on a particular machine.  It applies to all machines, anywhere in the universe.  It is independent of Relativistic special physics.  The Cannae and EM-Thruster and loaded horn and other experiments are just one kind of force-producing machines.  They take electricity and with a "k" measured in "newtons per watt", produce some force from the energy.

The ONLY exception to this is where V = c, and where V = c = 1/k, and therefore k = 1/c.  This particular case is the case where "light drives" or other electromagnetic emitters derive their force. They are not "free energy devices" either, because they can not go faster than c, by Einstein's relativity.  Moreover, the energy (E) that they're beaming away, if one believes (E = mc²), is actually equivalent to mass loss, so the device wouldn't be a reaction-massless thruster.  It is a special case, but one that doesn't require changing the V=1/k identity.

Hope that helps soften your conviction, just a bit. If you read frobnicat's assertions (early in this forum thread), you will find them to be almost exactly the same mathematical derivation that I made much later on.  It is deeply amusing (and pleasing) to me to see that the language of physics, which is mathematics isn't just universal enough for us to independently come to the same conclusion(s), but also that we took nearly the same reasoning path in the derivation. 

That is the Physics Challenge.

GoatGuy
Title: Re: EM Drive Developments
Post by: sghill on 09/16/2014 02:28 pm
...building a generator out of an EM drive would be no different than using an electric fan to drive a wind power generator.

That's just not even wrong.  Everybody knows that you use an electric fan to power your sailboat.  Sheesh.

Or push your sail-powered wash tub along on roller skates!
Title: Re: EM Drive Developments
Post by: Star One on 09/16/2014 02:29 pm


shows that Shawyer/SPR Ltd.'s EM drive is claimed (with "measurements" performed elsewhere -not at NASA-)  to have a thrust force 2000 to 4000 times higher than the drives recently tested at NASA.

What information does WiredUK have in this regard?
Is Shawyer/SPR Ltd.'s EM drive going to go into orbit soon - at a cost less than $100k-?


I'm a freelance, but Wired UK have been about the only people who will accept articles on this for the last few years.

Unfortunately, Roger Shawyer seems to have been left on the sidelines on this one and SPR are not in a position to launch. I'm currently trying to find out what happened to the UK evaluation of his technology in 2009, but that seems to have been lost. He looks like being a pioneer whose work was taken up by others.

Cannae are certainly continuing their work and have previously discussed a Cubesat mission with a thruster producing 3 micronewtons -- note their website is back up again now in slightly altered form --
http://cannae.com//2-uncategorised/48-cubesat
There is no indication who they are partnering with, but we they have talked to various aerospace players previously.

Yang Juan's work is also progressing largely undercover, but does appear to be progressing. I wrote a piece about this for Aviation Week which should appear shortly. My guess would be they will be the first to launch, unless NASA decide to sieze the initiative. However, the lack of comments from NASA suggests that the agency do not have any great appetitie for it, but I would be interested to hear otherwise. The lack of public statements for a new development doesn't seem normal to me, but others may know better?

Isn't the reason we haven't heard much from NASA because from what's been said a lot of the people involved in this work have NDAs in place concerning what they can & cannot talk about it?
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 02:35 pm

....
Isn't the reason we haven't heard much from NASA because from what's been said a lot of the people involved in this work have NDAs in place concerning what they can & cannot talk about it?

As a taxpayer, my expectation is that any NDA's between NASA and private companies would cover proprietary internal design of the EM drives but not the results of actual tests performed at NASA, including how the tests were conducted at NASA, details of NASA's inverted torsional pendulum set-up, etc., unless they would invoke issues of National Security, in which case it would not be a question of NDA's with private entities, but a matter of security.  I have not seen anything published claiming National Security issues.


Title: Re: EM Drive Developments
Post by: Star One on 09/16/2014 02:47 pm


....
Isn't the reason we haven't heard much from NASA because from what's been said a lot of the people involved in this work have NDAs in place concerning what they can & cannot talk about it?

As a taxpayer, my expectation is that any NDA's between NASA and private companies would cover proprietary internal design of the EM drives but not the results of actual tests performed at NASA, including how the tests were conducted at NASA, details of the inverted torsional pendulum set-up, etc., unless they would invoke issues of National Security, in which case it would not be a question of NDA's with private entities, but a matter of security.  I have not seen anything published claiming National Security issues.

NDAs are used by the military, those who have flown as tanker pilots to refuel for experimental projects are made to sign them apparently.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/16/2014 02:47 pm
Unless NASA has already built a device that can launch a missile, the amount of thrust reported would not be useful for anything other than VERY LONG range missile launches (from other planets), which obviously make no sense at all.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/16/2014 02:50 pm
  It is deeply amusing (and pleasing) to me to see that the language of physics, which is mathematics isn't just universal enough for us to independently come to the same conclusion(s), but also that we took nearly the same reasoning path in the derivation. 


https://www.youtube.com/watch?v=obCjODeoLVw

"and there is a very important thing that people who study physics who come from mathematics do not appreciate: physics is not mathematics and mathematics is not physics. One HELPS the other.".
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 02:55 pm


....
Isn't the reason we haven't heard much from NASA because from what's been said a lot of the people involved in this work have NDAs in place concerning what they can & cannot talk about it?

As a taxpayer, my expectation is that any NDA's between NASA and private companies would cover proprietary internal design of the EM drives but not the results of actual tests performed at NASA, including how the tests were conducted at NASA, details of the inverted torsional pendulum set-up, etc., unless they would invoke issues of National Security, in which case it would not be a question of NDA's with private entities, but a matter of security.  I have not seen anything published claiming National Security issues.

NDAs are used by the military, those who have flown as tanker pilots to refuel for experimental projects are made to sign them apparently.

The military restricts information for reasons of National Security.

NASA was set up, on purpose, by President Eisenhower as a Civilian Administration - not part of the Department of Defense.  NASA is responsible for the civilian space program as well as for civilian aeronautics and aerospace research.

See the exceptions that apply to the Freedom of Information here:

Federal Government:  http://www.foia.gov/  and here:  http://www.foia.gov/about.html

Department of Defense Freedom of Information:  http://www.dod.mil/pubs/foi/

NASA Freedom of Information:  http://www.hq.nasa.gov/office/pao/FOIA/

and here:

http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&sid=97fb51c6e62b667333b7f1645d203f11&rgn=div5&view=text&node=14:5.0.1.1.8&idno=14
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 03:17 pm
Hah!  I mentioned something along these lines in another propellantless thread:

The device aims to convert electricity to forward motion.

We already have a device which converts electricity to rotational motion, known as the electric motor.  It depends upon  the wheel, in order to instantaneously press, in a frictional fashion, against a local gravitational mass to convert the rotational force into forward motion.

These guys are claiming to have bypassed the wheel.  My.  Best.  Invention.  Ever.

There are two problems which have not yet been addressed or answered.  "Push heavy, pull light", which is the summary of the M-E device's operation, relies upon action at a distance with the inertia of the entire Hubble sphere surrounding the device. 

Conservation of momentum.
[Edit 10-03-14:  Struck out the above stray phrase.]

And then the free energy part, which I give little heed as a knee jerk reaction resulting from calculitis.

Quote from: GoatGuy
And until a Physicist pops up here, armed with better math to disprove the Newtonian physics conclusion ... the assertions I made will continue to show that at a velocity above 1/k, all force-making machines produce more kinetic power than the electrical, chemical, nuclear or whatever else power that the machine uses to create the force it produces.

That is a very powerful assertion .. It does not depend on a particular machine.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/16/2014 03:21 pm
from Talk Polywell Forums

a little part of the post by GiThruster that I posted here
Quote from: GiThruster
I would never pretend to speak for Paul, but I can relate to you what his positions have been in the past. Last I heard, he was still maintaining he believed that Sonny's QVF model and Jim's M-E model were opposite sides of the same coin, despite Jim, Sonny and myself keep arguing this cannot be true.

Quote from: Birchoff
Why is it not possible for QVF and ME to be "opposite sides of the same coin"

Quote from: Paul March
Dr. Woodward maintains that the M-E's mass fluctuations occur in the "squishy" intermolecular chemical bonds of the dielectric and not in the rest mass of the ions in question. Next question is what are these squishy intermolecular chemical bonds made of? They are typically called covalent sharing of molecular electrons and/or an imbalance of ionic electric charges between the charged ions. Ok then what is in between the electrons and ions in these dielectric molecules that is affected by the M-E equation's transient gravity waves, or in other words what do the M-E's pressure transients in the cosmological gravitational field affect in between the molecules that for all practical purposes is a pure vacuum state. A vacuum state filled only with virtual photons of the electric fields and perhaps the virtual e/p pairs of the quantum vacuum. That is why I continue to say that Dr. White in only trying to answer what Woodward's M-E "gravity" pressure waves are effecting at the molecular and subatomic scales. A place that Dr. Woodward refuses to go to this date except perhaps in his musings on the ADM electron structure where the gravitational field is used to counter balance the electrostatic field forces, but once again ignoring the basic question of what either of these fields are composed of. That is supposed to be the realm of quantum gravity, but since no one has come up with an accepted answer for same, Dr. White is free to suggest his own.

Next, in regards to the Boeing SFE work that the Eagleworks Lab performed back in the spring of 2013, since it was and is covered by NDAs, all I can comment on is the already released Eagleworks 2013 newsletter that has been pointed to on this forum. I can however assure you that these results were run in a hard vacuum (~5x10^-6 Torr) and are categorically NOT ion wind or unbalanced electrostatic charges.

from Ron Stahl: "I am still on record that I don't trust the data coming from Eagle, but..."

I have to reassure Mr. Stahl that I have always reported and will continue to report the actual data that I recorded In our Eagleworks Lab reports and that Dr. White has never asked me to falsify any of this data we have presented. If you think otherwise that is your privilege, but it's not an accurate picture in any way.

Best,

Quote from: GiThruster
Well Paul, two things. First, in your analysis of the two models, you fail to note that they have completely contradictory positions about where inertia comes from. They in fact form an exhaustive disjunction. Either inertia comes from the ZPF, or it comes from gravity, but certainly it makes no sense to say it comes from both. These are not the same. And this is why Sonny has always argued that Jim must be wrong, and Jim has always argued that Sonny must be wrong. They could both be wrong. Inertia could be an intrinsic property of matter, but they cannot both be right and this is just what they say about what they propose.

Second thing yes, I understand you are reporting accurately as possible about what has been done in the lab. I also understand that (he makes here some accusations about Sonny White's character, which I preffer to not post here)

I am curious though, about one seemingly noteworthy part of this puzzle. Who had you sign an NDA? Sonny and Eagleworks, yes? Okay. Could you explain to me why Sonny said in his interview with PopSci that what he could say was restrained by an NDA? Who did Sonny sign an NDA with?


last paragraph in bold seems to ask questions relevant to the last posting on this thread, regarding NDAs.
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 03:25 pm
...

The point about the Cannae drive is not how much thrust it produced in the NASA test compared to other designs, but whether their 3 micronewton design is plausible. Because if they have backing, it will be built and  launched.

..

@Wembley

I still don't understand why would somebody want to put in orbit the "Cannae drive [with] their 3 micronewton design "  as you suggest, when Paul March's Woodward-Effect device has been repeatedly tested by him, and reported by NASA's Dr. White (slide 40 of previously linked reference) as having measured 1000 (one thousand) times greater thrust.    What is the advantage of the Cannae device compared to Paul March's? Do you have information that its minute measured thrust is more trustworthy or better in some sense?

__

PS: the actual reported measured thrust by NASA for the Cannae device was 40 microNewtons (not 3 microNewtons)
Title: Re: EM Drive Developments
Post by: mheney on 09/16/2014 03:37 pm
...

The point about the Cannae drive is not how much thrust it produced in the NASA test compared to other designs, but whether their 3 micronewton design is plausible. Because if they have backing, it will be built and  launched.

..

@Wembley

I still don't understand why would somebody want to put in orbit the "Cannae drive [with] their 3 micronewton design "  as you suggest, when Paul March's Woodward-Effect device has been repeatedly tested by him, and reported by NASA's Dr. White (slide 40 of previously linked reference) as having measured 1000 (one thousand) times greater thrust. 

That argument is the equivalent of saying "I don't see why you'd want to spend money on spaceflight when there are so many starving people in the world."

Everyone has their own priorities - and that's a good thing, as it means many different things get tried (and done.)   What others choose to do (or not do) are a distraction to the case you want to make.
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 03:43 pm
from Talk Polywell Forums

Quote from: Paul March
......

Next, in regards to the Boeing SFE work that the Eagleworks Lab performed back in the spring of 2013, since it was and is covered by NDAs, all I can comment on is the already released Eagleworks 2013 newsletter that has been pointed to on this forum. I can however assure you that these results were run in a hard vacuum (~5x10^-6 Torr) and are categorically NOT ion wind or unbalanced electrostatic charges.


Interesting new information: the Boeing SFE device, which has a specific force thousands of times larger than the Cannae or the Frustum (Tapered Cavity) devices, was tested in a vacuum.  On the other hand, the Cannae or the Frustum (Tapered Cavity) devices were not tested in a vacuum, as of the "Anomalous thrust..." paper.
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 03:49 pm
...

The point about the Cannae drive is not how much thrust it produced in the NASA test compared to other designs, but whether their 3 micronewton design is plausible. Because if they have backing, it will be built and  launched.

..

@Wembley

I still don't understand why would somebody want to put in orbit the "Cannae drive [with] their 3 micronewton design "  as you suggest, when Paul March's Woodward-Effect device has been repeatedly tested by him, and reported by NASA's Dr. White (slide 40 of previously linked reference) as having measured 1000 (one thousand) times greater thrust. 

That argument is the equivalent of saying "I don't see why you'd want to spend money on spaceflight when there are so many starving people in the world."

Everyone has their own priorities - and that's a good thing, as it means many different things get tried (and done.)   What others choose to do (or not do) are a distraction to the case you want to make.

It was not an argument, it was a question:

What is the advantage of the Cannae device compared to Paul March's? Do you have information that its minute measured thrust is more trustworthy or better in some sense?

Apparently you posted 2 seconds after I was done editing my post, to include the question  :), so you didn't have time to see my question
Title: Re: EM Drive Developments
Post by: Stormbringer on 09/16/2014 04:09 pm
@aceshigh

Quote from: Paul March
Dr. Woodward maintains that the M-E's mass fluctuations occur in the "squishy" intermolecular chemical bonds of the dielectric and not in the rest mass of the ions in question. Next question is what are these squishy intermolecular chemical bonds made of? They are typically called covalent sharing of molecular electrons and/or an imbalance of ionic electric charges between the charged ions. Ok then what is in between the electrons and ions in these dielectric molecules that is affected by the M-E equation's transient gravity waves, or in other words what do the M-E's pressure transients in the cosmological gravitational field affect in between the molecules that for all practical purposes is a pure vacuum state. A vacuum state filled only with virtual photons of the electric fields and perhaps the virtual e/p pairs of the quantum vacuum. That is why I continue to say that Dr. White in only trying to answer what Woodward's M-E "gravity" pressure waves are effecting at the molecular and subatomic scales. A place that Dr. Woodward refuses to go to this date except perhaps in his musings on the ADM electron structure where the gravitational field is used to counter balance the electrostatic field forces, but once again ignoring the basic question of what either of these fields are composed of. That is supposed to be the realm of quantum gravity, but since no one has come up with an accepted answer for same, Dr. White is free to suggest his own.


This part fired up my random silly question generator.  Has anyone every did one of these devices with bismuth as an intrinsic part of the device? This summary of Woodward's description as squishy intra-molecular bond stuff reminds me of (mostly) fringe claims about the unusual nucleonic shell shape and electronic configuration of Bismuth.

as an aside to this aside... the spell checker for this website sure could use some tuning up. molecular is spelled molecular, nucleonic really is a word; etc.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/16/2014 04:14 pm
@Stormbringer, please correct your last post because you added your text inside my quote.
Title: Re: EM Drive Developments
Post by: wembley on 09/16/2014 04:16 pm
...

The point about the Cannae drive is not how much thrust it produced in the NASA test compared to other designs, but whether their 3 micronewton design is plausible. Because if they have backing, it will be built and  launched.

..

@Wembley

I still don't understand why would somebody want to put in orbit the "Cannae drive [with] their 3 micronewton design "  as you suggest, when Paul March's Woodward-Effect device has been repeatedly tested by him, and reported by NASA's Dr. White (slide 40 of previously linked reference) as having measured 1000 (one thousand) times greater thrust.    What is the advantage of the Cannae device compared to Paul March's? Do you have information that its minute measured thrust is more trustworthy or better in some sense?

__

PS: the actual reported measured thrust by NASA for the Cannae device was 40 microNewtons (not 3 microNewtons)


Cannae own the rights to their drive, not Woodward's. That's why they go with theirs.
The page on their website describing the cubesat describes at producing an adequate 3 micronewtons.

The appear to have backing, the other drive doesn't. Therefore, whatever the technical merits, they win.
Title: Re: EM Drive Developments
Post by: wembley on 09/16/2014 04:18 pm


shows that Shawyer/SPR Ltd.'s EM drive is claimed (with "measurements" performed elsewhere -not at NASA-)  to have a thrust force 2000 to 4000 times higher than the drives recently tested at NASA.

What information does WiredUK have in this regard?
Is Shawyer/SPR Ltd.'s EM drive going to go into orbit soon - at a cost less than $100k-?


I'm a freelance, but Wired UK have been about the only people who will accept articles on this for the last few years.

Unfortunately, Roger Shawyer seems to have been left on the sidelines on this one and SPR are not in a position to launch. I'm currently trying to find out what happened to the UK evaluation of his technology in 2009, but that seems to have been lost. He looks like being a pioneer whose work was taken up by others.

Cannae are certainly continuing their work and have previously discussed a Cubesat mission with a thruster producing 3 micronewtons -- note their website is back up again now in slightly altered form --
http://cannae.com//2-uncategorised/48-cubesat
There is no indication who they are partnering with, but we they have talked to various aerospace players previously.

Yang Juan's work is also progressing largely undercover, but does appear to be progressing. I wrote a piece about this for Aviation Week which should appear shortly. My guess would be they will be the first to launch, unless NASA decide to sieze the initiative. However, the lack of comments from NASA suggests that the agency do not have any great appetitie for it, but I would be interested to hear otherwise. The lack of public statements for a new development doesn't seem normal to me, but others may know better?

Isn't the reason we haven't heard much from NASA because from what's been said a lot of the people involved in this work have NDAs in place concerning what they can & cannot talk about it?
No, it's not that. NASA won't discuss the tests, the Q-Thruster program, the recent paper, or anything related to it, AT ALL, nor make any public statement that they might have an interesting new technology.
 I suspect that's unusual.
Title: Re: EM Drive Developments
Post by: Stormbringer on 09/16/2014 04:22 pm
@Stormbringer, please correct your last post because you added your text inside my quote.

Done.

The weird thing is in the editor i do not see a nested quote. i see only a quote at the beginning and ending of the bit about Dr Woodward's thoughts. this has happened to me before when i pared down a massively nested multi-quote post. the coding for a global quote was invisible to me and i had no idea how to fix it.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 04:27 pm
@Stormbringer, please correct your last post because you added your text inside my quote.

Done.

The weird thing is in the editor i do not see a nested quote. i see only a quote at the beginning and ending of the bit about Dr Woodward's thoughts. this has happened to me before when i pared down a massively nested multi-quote post. the coding for a global quote was invisible to me and i had no idea how to fix it.

Do your editing in 'Notepad' outside of the forum' inadequate editing window.  The simple html codes will be visible there.  Still, multiple nestings get corny when you lose track of them.  I've had to re-edit countless times immediately after posting in order to get the quotes right.
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 04:34 pm
....

We already have a device which converts electricity to rotational motion, known as the electric motor.  It depends upon  the wheel, in order to instantaneously press, in a frictional fashion, against a local gravitational mass to convert the rotational force into forward motion.

....

Feynman has a trick question in his classic book "Lectures on Physics" (I think volume II) on another electromagnetic effect that can produce rotary motion (but not translational linear motion by itself).   

The interesting thing about Paul March's 2004 and 2005 experiments and some of Prof. Woodward's experiments is that they were conducted with load cells, with the device experiencing vertical acceleration (not rotational motion).
Title: Re: EM Drive Developments
Post by: frobnicat on 09/16/2014 04:55 pm
@GoatGuy, please don't overemphasize our mathematical prowess too much, as our derivations are at a modest undergrad level (at most) and if a real mathematician were to come along and expected to talk with us of the monstrous moonshine (http://en.wikipedia.org/wiki/Monstrous_moonshine) as a likely connexion between AdS/CFT correspondence and the EMdrive effect, on equal footing, well this could be embarrassing.
That said, I'm glad our (yes) hard-earned maths/physics skills could be put to good use in those little pedagogical and hopefully conclusive arguments and are online for the posterity. The only reason not many professional scientists didn't even bother to comment on that case probably because of the instant trivial obviousness of this line of reasoning and conclusion, unlimited energy from an engine running at the bottom of the well : why it's all the more strange that it's not more loudly shouted by proponents of the effect being real (only some "well maybe yes, also it's more complicated than you think, let us show how it all depends on the cosmic horizon...")

Dr Rodal: your efforts at clarifying the experimental situation for various setup are greatly appreciated. Could you add to your list the thrust/power figure for the only both theoretically sound and experimentally proven "thrust from power" that is photon rocket  1/c  ?
Not as a provocation, just as a reminder to put things into perspective.

Now for the provocation : my doctor prescribed me a diet of at most a post a day on NSF, and recommended to diversify my readings, EMDrive thread develops too much cholesterol. Good cholesterol but still cholesterol.
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 04:59 pm
,,,,

Dr Rodal: your efforts at clarifying the experimental situation for various setup are greatly appreciated. Could you add to your list the thrust/power figure for the only both theoretically sound and experimentally proven "thrust from power" that is photon rocket  1/c  ? ...

<< a large military searchlight is a photon rocket in a sense, but yields less than one ten-thousandth of a pound of thrust for a power consumption of 100 kilowatts.>> see:  http://history.nasa.gov/conghand/propulsn.htm

so, that is a

SPECIFIC FORCE = 4.45 *10^(-6) N/kW

(This is 33% higher than the theoretical thrust per input-power-required for a perfectly collimated output beam, but let's take this higher number, from this NASA source, as an upper bound (a bound impossible to approach for a photonic rocket) .  The 33% difference is insignificant compared to the numbers below )
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 05:03 pm
The NASA-tested (in a vacuum) Boeing/DARPA device, NASA-reported specific force is up to 4.5 million times larger than the one of a "Large military searchlight as a photon rocket"


The NASA-tested (not in a vacuum) Cannae microwave device,  NASA-reported specific force is 300 times larger than the one of a "Large military searchlight as a photon rocket"

_______________________________________________
_______________________________________________


Large military searchlight as a photon rocket:

SPECIFIC FORCE = 4.45 *10^(-6) N/kW

(This specific thrust, from http://history.nasa.gov/conghand/propulsn.htm,  is 33% higher than the theoretical thrust per input-power-required for a perfectly collimated output beam, but let's take this higher number, from this NASA source, as an upper bound.  The 33% difference is insignificant compared to the numbers below )

Experimental data not obtained using Dr. White's NASA inverted torsion pendulum

______________________________

Shawyer/SPR Ltd.'s microwave device:


SPECIFIC FORCE = 0.02 to 0.4 N/kW  (4500 to 90 000 times larger than the photon rocket)

______________________________

Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2004:   


SPECIFIC FORCE=  0.4 N/kW   (up to 90 000 times larger than the photon rocket)

______________________________

Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2005: 


SPECIFIC FORCE=  0.3 N/kW  (up to 67 000 times larger than the photon rocket) 

______________________________
******************************
Experimental data obtained using Dr. White's NASA inverted torsion pendulum

(tested in a vacuum)

Boeing/DARPA device:


SPECIFIC FORCE = 1 to 20 N/kW (225 000 to 4.5 million times larger than the photon rocket)

______________________________

Cannae Testing:

(not tested in a vacuum by NASA)

SPECIFIC FORCE:  0.0014 N/kW  (up to 300 times larger than the photon rocket)
______________________________

Tapered (Frustum) Cavity Testing: 

(not tested in a vacuum by NASA)

SPECIFIC FORCE=  0.003 N/kW to 0.0054 N/kW  (700 to 1200 times larger than the photon rocket)

______________________________
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 06:51 pm
@Fornaro, chi va piano, va sano e va lontano.

Rodal:

Grazie per i consigli. Il mio problema è leggermente diverso:

Il male dell'agnello, cresce la pancia e cala l'uccello.

Solo dicendo.
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 07:10 pm
@Fornaro, chi va piano, va sano e va lontano.

Rodal:

Grazie per i consigli. Il mio problema è leggermente diverso:

Il male dell'agnello, cresce la pancia e cala l'uccello.

Solo dicendo.

I frutti proibiti sono i più dolci.

Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 07:47 pm
...The only reason not many professional scientists didn't even bother to comment on that case probably because of the instant trivial obviousness of this line of reasoning and conclusion, unlimited energy from an engine running at the bottom of the well : why it's all the more strange that it's not more loudly shouted by proponents of the effect being real....

Well, Drafta's  "Proposal for experimental verifying of Machian transient mass fluctuations"(http://arxiv.org/ftp/gr-qc/papers/0102/0102002.pdf) , using Woodward's <<Mach's principle who assert that inertia of the bodies is caused by interaction between bodies and the distant matter from Universe.>> did state
<<If experiment will succeed, this opens the possibility to realize new kind of devices for energy production>>.

Also, concerning using the zero-point quantum vacuum there are several patents where the authors attempt to extract energy from the zero-point quantum vacuum  :).  One extreme position is to take the naive Quantum Mechanics viewpoint that the quantum vacuum energy is infinite, by including energy of waves with arbitrarily short wavelengths   :).

<< Current claims to zero-point-energy-based power generation systems are considered pseudoscience by the scientific community at large [12][13] and skeptics usually dismiss efforts to harness zero-point energy by default.

....

According to a NASA contractor report, "the concept of accessing a significant amount of useful energy from the ZPE gained much credibility when a major article on this topic was published in Aviation Week & Space Technology (March 1st, 2004), a leading aerospace industry magazine".

For a destruction of several claims to tap energy from the zero-point quantum-vacuum see pages 65 to 80 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050170447.pdf]>>  http://en.wikipedia.org/wiki/Zero-point_energy
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/16/2014 07:51 pm
@Fornaro, chi va piano, va sano e va lontano.

Rodal:

Grazie per i consigli. Il mio problema è leggermente diverso:

Il male dell'agnello, cresce la pancia e cala l'uccello.

Solo dicendo.

I frutti proibiti sono i più dolci.

Ai chihuahua, so to speak...
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 08:02 pm
Also see p. 84 of this NASA report  http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050170447.pdf

<<5.2.7 Overview of Patented Reactionless Propulsion Devices>>
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 08:05 pm
@Fornaro, chi va piano, va sano e va lontano.

Rodal:

Grazie per i consigli. Il mio problema è leggermente diverso:

Il male dell'agnello, cresce la pancia e cala l'uccello.

Solo dicendo.

I frutti proibiti sono i più dolci.

Ai chihuahua, so to speak...

¡Ay, caramba!
Title: Re: EM Drive Developments
Post by: Rodal on 09/16/2014 08:13 pm
T. Valone (who is referred above in p. 84 of NASA report  http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050170447.pdf) has this paper in 2012  "Electrokinetics as a Propellantless Propulsion Source" :)
http://ac.els-cdn.com/S1875389212025023/1-s2.0-S1875389212025023-main.pdf?_tid=24883a44-3dde-11e4-882b-00000aab0f01&acdnat=1410898683_c2f29cf1462ae114ed1ccc8f6d085c22

<<Electrokinetics, which often involves a capacitor and dielectric, has virtually no relationship
that can be connected with mass or gravity. The Army Research Lab has recently issued a report on
electrokinetics, analyzing the force on an asymmetric capacitor, while NASA has received three patents
on the same design topic. ... This paper also reviews the published electrokinetic experiments by the Army
Research Lab by Bahder and Fazi, California State University at Fullerton work by Woodward and
Mahood, Erwin Saxl, and others.>>

Valone also discusses the Feynman disc "paradox".  This "paradox" is in his Lectures on Physics book (http://www.amazon.com/Feynman-Lectures-Physics-Commemorative-Issue/dp/0201500647/ref=sr_1_3?ie=UTF8&qid=1410899309&sr=8-3&keywords=feynman+lecture+on+physics).  Reach for your bookcase, the one with the sizable mass effect, for Volume 2, article 17-5 on pages 17-5 and 17-6 and look at Fig. 17-5.

______________

What do I think?  I think that people interested in these effects should take a look at the Abraham-Minkowski controversy, which can always be resolved with the concept of "hidden momentum" as done by the inventor of the transistor,  W Shockley http://www.ncbi.nlm.nih.gov/pmc/articles/PMC225123/pdf/pnas00121-0067.pdf

Constitutive laws governing material behavior cannot be addressed just from general principles as attempted by Minkowski, one must resort to experiments or to physical modeling as done by Shockley.  Or, as done by Abraham, one must enforce symmetry in the stress tensor (otherwise if one insists in using Minkowski's unsymmetric formulation one must include extra terms and/or integrate over a larger volume to represent reality).  Otherwise one ends up with some unphysical concepts  :)
Title: Re: EM Drive Developments
Post by: RanulfC on 09/16/2014 09:54 pm
@Fornaro, chi va piano, va sano e va lontano.

Rodal:

Grazie per i consigli. Il mio problema è leggermente diverso:

Il male dell'agnello, cresce la pancia e cala l'uccello.

Solo dicendo.

I frutti proibiti sono i più dolci.

Ai chihuahua, so to speak...

¡Ay, caramba!

Thanks for reminding me I needed to update my profile with some latin :)

Randy
Title: Re: EM Drive Developments
Post by: aceshigh on 09/16/2014 10:23 pm
Por que latim, se estavam falando em italiano e depois em espanhol com termos típicos mexicanos? Línguas românticas, isso sim.

anyway, the german cousin of my wife visited us a couple of years ago. Since she is studying latin in Germany (she wants to be a translator and also teacher, and there is work according to her, because Germany uses roman law code and lawyers there need to learn a good deal of latin), and she was able to, just through etimology connecting either directly to latin or to french, read 95% of an entire article in a magazine at our home without ever learning the language itself (brazilian portuguese)


in other news, GoatGuy is proclaiming victory, at the NextBigFuture comments section, because nobody countered his mathematics here.  ::)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/17/2014 12:37 am
Por que latim, se estavam falando em italiano e depois em espanhol com termos típicos mexicanos? Línguas românticas, isso sim. ...

Well, like they say: 

Latin is a language.
As dead as dead can be.
First it killed the Romans.
Now it's killing me.
Title: Re: EM Drive Developments
Post by: birchoff on 09/17/2014 01:12 am

....
Isn't the reason we haven't heard much from NASA because from what's been said a lot of the people involved in this work have NDAs in place concerning what they can & cannot talk about it?

As a taxpayer, my expectation is that any NDA's between NASA and private companies would cover proprietary internal design of the EM drives but not the results of actual tests performed at NASA, including how the tests were conducted at NASA, details of NASA's inverted torsional pendulum set-up, etc., unless they would invoke issues of National Security, in which case it would not be a question of NDA's with private entities, but a matter of security.  I have not seen anything published claiming National Security issues.

Not sure how this isn't exactly the case preventing complete disclosure. As I see it, The paper that was published at the AIAA conference, included a lot of details on the testing protocol, which covers how the tests were performed along with information on the pendulum set-up. Now there are a few details that were missing, but your open letter to the research team prompted Paul March to fill those details in. The only thing that seems to have been left out from the published paper is the same level of detail about the Boeing SFE test article. Which we now know was covered by NDA, according to Paul March. A bare bones NDA would most likely cover the details about how the test article works and any analysis that could potentially allow someone to reverse engineer the device. Which means any inclusion in the AIAA paper alongside the descriptions of the Cannae and Tapered Frustum would amount to a foot note covering only the information found in the deck you previously linked to.

Now I am as annoyed as anyone else about this, as the inclusion of the information on the Boeing test article would most likely strengthen the case against the critics that there is a high statistical probability that there is a real effect being studied by EagleWorks.
Title: Re: EM Drive Developments
Post by: aero on 09/17/2014 02:08 am
What do we think the probability is that there is a real effect?
First, how many devices where an effect is claimed can be included in the same "unknown energy source" bin?
answer is at a guess, 6.
At a guess, how probable is it that the claimant is correct? 50%? or wrong, 50%.
So what is the probability that they are all wrong? 2^-6 ? < 2%.
On the other hand, what is the probability that they are all correct? again, < 2%.

It is unfortunate that we don't know enough statistics to come up with a more telling answer because I really would like for us to get off the dime and go through some proposed theory of operation of the devices. Instead this discussion is swamped by some fast mud slingers for whom it is far more important to convince us that they are correct than it is to give us the latitude to investigate for ourselves.
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/17/2014 04:40 am
in other news, GoatGuy is proclaiming victory, at the NextBigFuture comments section, because nobody countered his mathematics here.

Nope.  No victory, just wondering at the quantitative / mathematical silence.  Perhaps in the future you could put a LINK, so that others may save themselves the trouble of figuring which of the thousands of GoatGuy comments you're referring to?

Just saying.
Have a nice day!

Title: Re: EM Drive Developments
Post by: KelvinZero on 09/17/2014 04:48 am
@aero:
I would say that if the general scientific community considered there to be a 10% chance that the effect was real then it would be the hottest topic in physics today, because the ramifications are so huge both at a theoretical and a practical level, and it is so accessible to testing compared to say, the hunt for the Higgs particle.

btw, there was mention of an interpretation (I cannot remember if it were for the EM drive or another) whereby efficiency would drop off in some form so that it did not deliver free energy.

Was there any description of how this would behave? (Im not to concerned with the deeper theory. I know that I could not possibly understand something that is not obvious to the physics community. I just like to know how to describe the behavior, so I could at least imagine how it would operate in some hardSF universe)

(IslandPlaya wondered if it could be the frame that is stationary wrt to the CMB, which I found really cool regardless of whether there is a mechanism explaining why. Suddenly it becomes something we can at least describe, and it has cool easter eggs like a free 400kms boost in one direction.)
Title: Re: EM Drive Developments
Post by: 93143 on 09/17/2014 05:43 am
No victory, just wondering at the quantitative / mathematical silence.

I already explained why you can't do energy conservation on a single object experiencing a net force.

If you're just trying to show that if it works, you could build something that looks a lot like a classic perpetual motion machine, I won't disagree.  But if you're trying to show that it is a classic perpetual motion machine and thus cannot possibly be real, you're doing it wrong.

What you've done is show that a device that violates conservation of momentum also violates conservation of energy.  This doesn't address devices that purportedly push on something; to do that you'd have to show that the physics of the pushing are necessarily inconsistent given the proposed principle of operation.

OK, that being what it is, then if we are pushing against the Universe, then it must be relative to our velocity compared to the universe's velocity frame.  There is no way around that one, I'm afraid.

I'm not so sure about that; taking the Mach-effect case and assuming the gravity wave explanation is correct, it seems to me that we're dealing with an interaction that should be subject to the Doppler effect, in an expanding universe.  Alternately, a different explanation for the interaction might prevail; Woodward himself has offered two, only one of which is radiative, and the implications of the other regarding this question are not immediately clear to me.  What I'm trying to suggest is that the "universe's velocity frame" may not be independent of the velocity of the device.

Certainly the Mach-effect equation itself is Lorentz invariant - it makes no reference at all to any external velocity frame.  So if the equation is right, then somehow the effective average velocity of the far-off active mass must track that of the thruster, and it can't be a random coincidence that it does; it has to be inherent in the theory and show up when the theory is properly explored.  The same is true of the Q-thruster - the vacuum doesn't change based on the velocity of the observer; neither do any vacuum fluctuations caused by something at the same velocity as the observer.  The theoretical explanation for where the momentum and energy come from may be complicated or obscure, but it is not immediately obvious that there can't be one.

I find it mildly interesting that in Sciama's Machian inertia derivation, which is specific to the FRW cosmological model, the mean velocity of the causally-connected universe does show up, but only in intermediate steps; the final result only contains its time derivative.

Quote
It also might imply that there wouldn't be directionality anisotropy, as the inertial wind could be directly related to the expansion of SpaceTime itself, which we now know to be ongoing, and accelerating itself.  Energy from latching onto the expansion of the Universe.  Wow.  That'd be a big supply!

Yes it would.
Title: Re: EM Drive Developments
Post by: Star One on 09/17/2014 07:47 am


....
Isn't the reason we haven't heard much from NASA because from what's been said a lot of the people involved in this work have NDAs in place concerning what they can & cannot talk about it?

As a taxpayer, my expectation is that any NDA's between NASA and private companies would cover proprietary internal design of the EM drives but not the results of actual tests performed at NASA, including how the tests were conducted at NASA, details of NASA's inverted torsional pendulum set-up, etc., unless they would invoke issues of National Security, in which case it would not be a question of NDA's with private entities, but a matter of security.  I have not seen anything published claiming National Security issues.

Not sure how this isn't exactly the case preventing complete disclosure. As I see it, The paper that was published at the AIAA conference, included a lot of details on the testing protocol, which covers how the tests were performed along with information on the pendulum set-up. Now there are a few details that were missing, but your open letter to the research team prompted Paul March to fill those details in. The only thing that seems to have been left out from the published paper is the same level of detail about the Boeing SFE test article. Which we now know was covered by NDA, according to Paul March. A bare bones NDA would most likely cover the details about how the test article works and any analysis that could potentially allow someone to reverse engineer the device. Which means any inclusion in the AIAA paper alongside the descriptions of the Cannae and Tapered Frustum would amount to a foot note covering only the information found in the deck you previously linked to.

Now I am as annoyed as anyone else about this, as the inclusion of the information on the Boeing test article would most likely strengthen the case against the critics that there is a high statistical probability that there is a real effect being studied by EagleWorks.

Would you say the NDAs are there for commercial reasons or national security?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/17/2014 01:37 pm
Cognitive infiltration alert:

Quote
According to a NASA contractor report, "the concept of accessing a significant amount of useful energy from the ZPE gained much credibility when a major article on this topic was published in Aviation Week & Space Technology (March 1st, 2004), a leading aerospace industry magazine".

The reader is supposed to conclude that the act of publishing an article, regardless of its proven factuality, particularly in a news organ, not a peer reviewed organ, is the only criteria for imagined "credibility".

Publishing an article in AIAA or another respected journal, while it gives a certain amount of tentative credibility to a concept, offers no guarantee of factuality.

Also, remember that the term "NASA contractor", particularly when anonymous and associated with extraordinary claims, yields no real credibility, but only apparent credibility.

The faith based belief in "free" energy from ZPE will have to be proven and demonstrated so that the qualifer of "scientific proof" can bew used to substitute for the qualifier "faith based".

Too early for Scotch, even by my liberal standards.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/17/2014 01:37 pm
Quote from: DeucesLow
Por que latim, se estavam falando em italiano e depois em espanhol com termos típicos mexicanos? Línguas românticas, isso sim.

You forgot the bit o' ingles; "so to speak".

I can read that, without using a translator!  Not so sure about my promunciation, however.

As an aside, a PhD "friend" of mine suggested that I take a college course in calculus, so as to better hold my own here on the forum and in my career change.  And I might do that.  But right now, it is far more important to learn French, and while I'm at it, the other romance languages.

There are too many fascinating people on this forum, scattered among the hominems!

Ace, deuce, whatevs.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/17/2014 01:38 pm
in other news, GoatGuy is proclaiming victory, at the NextBigFuture comments section, because nobody countered his mathematics here.

Nope.  No victory, just wondering at the quantitative / mathematical silence. ...

Back to regular programming:  GoatGuy shouldn't crow too much.

if [k] is the EM-drive thrust factor, in Newtons-per-Watt (which has been widely used and quoted) then...

V = 1/k ... is the velocity of the Q-device, where the kinetic energy it creates matches the input energy and...

V = 2/k ... is the velocity of a free-floating spacecraft employing the EM-thruster, where the TOTAL energy invested equals the TOTAL imparted kinetic energy of the spacecraft. ...

Whoah there kemosabe.  Remember, I don't know much about the French I took (http://www.youtube.com/watch?v=i6GM1pxGVnQ).  Speak slower.

If velocity is m/sec, and k is N/W, work thru the derivation for v = 1/k for me?

1/k = 1/(N/W) = W/N
N = kg (m/sec^^2)
W = N m/s = kg m^2/s^3

Ergo:

k = (kg (m/s^^2))/(kg m^2/s^3)
k = (m/s^2)/(m^2/s^3)
k = (m/s^2) (s^3/m^2)
k = s/m

Therefore:

1/k = m/s = v.

So I get that.

Where the heck does v = 2/k come from?

(Nomenclaturalistically speaking, I thought V was typically Volume, and v was typically velocity.  Solo dicendo.)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/17/2014 01:54 pm

....
Isn't the reason we haven't heard much from NASA because from what's been said a lot of the people involved in this work have NDAs in place concerning what they can & cannot talk about it?

As a taxpayer, my expectation is that any NDA's between NASA and private companies would cover proprietary internal design of the EM drives but not the results of actual tests performed at NASA, including how the tests were conducted at NASA, details of NASA's inverted torsional pendulum set-up, etc., unless they would invoke issues of National Security, in which case it would not be a question of NDA's with private entities, but a matter of security.  I have not seen anything published claiming National Security issues.

Not sure how this isn't exactly the case preventing complete disclosure. ... The only thing that seems to have been left out from the published paper is the same level of detail about the Boeing SFE test article. Which we now know was covered by NDA, according to Paul March. A bare bones NDA would most likely cover ... any analysis that could potentially allow someone to reverse engineer the device. Which means any inclusion in the AIAA paper ... would amount to a foot note covering only the information found in the deck you previously linked to.

Now I am as annoyed as anyone else about this, as the inclusion of the information on the Boeing test article would most likely strengthen the case against the critics that there is a high statistical probability that there is a real effect being studied by EagleWorks.

Is the term "annoyed" a homonym for the "c-word"?

If a device of this sort should work, he who gets it first, uses it first, and NatSec immediately comes into play.  so there's that.

Welcome, Rodal, to the real world of NASA where even cost is considered to be proprietary info not available for the taxpayer to know.  Nor even the USAF (http://forum.nasaspaceflight.com/index.php?topic=34977.msg1240653#msg1240653), in some cases.

IDK about the math behind your tentative "statistical probability" calculation.  Whether the device works as advertised or not has nothing whatsoever to do with the NDA's.  The NDA's are, well, prophylactic, just in case the device does work.

Like they say, you are "free" to develop a warp drive in the privacy of your own garage.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/17/2014 02:07 pm
...I'm not so sure about that; taking the Mach-effect case and assuming the gravity wave explanation is correct...

What if we assume that the gravity wave explanation is not correct?  Does the house of cards fall down?  And by "gravity wave", I'm thinking you're referring to the advanced/retarded wave notion?

Quote
Certainly the Mach-effect equation itself is Lorentz invariant ...

Which M-E equation?

Sciama 1953: phi = -2 pi rho c^2 tau^2? 

Which neglects terms of the order v^2/c^2, without explanation or justification, at least to me.

You go on:

Quote
I find it mildly interesting that in Sciama's Machian inertia derivation...

Again, Sciama 1953 or Sciama 1969?  Which derivation?  Like I asked; talk slower.  OK?  'Cause I'm not following.
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/17/2014 03:24 pm
if [k] is the EM-drive thrust factor, in Newtons-per-Watt (which has been widely used and quoted) then...

V > 1/k ... is the velocity .. where the Ek exceeds the input energy and...
V > 2/k ... is the velocity of a spacecraft ..  where Ek exceeds the TOTAL invested energy. ...

If velocity is m/sec, and k is N/W, work thru the derivation for v = 1/k for me?

1/k = 1/(N/W) = W/N
N = kg (m/sec²)
W = N m/s = kg m²/s³

Ergo:

k = (kg (m/s²))/(kg m²/s³)
k = (m/s²)/(m²/s³)
k = (m/s²)·(s³/m²)
k = s/m

Therefore:

1/k = m/s = v.

So I get that.
Where the heck does v = 2/k come from?

(Nomenclaturalistically speaking, I thought V was typically Volume, and v was typically velocity.  Solo dicendo.)

Dunno about the capitalization.  Maybe V is volume and v is velocity.  P is sometimes power, and p is often momentum, rather dodgy when talking about this branch of physics.  ρ is mass density, mainly, though it can also refer to charge density, resistivity, quantum states, and in statistics, the correlation coefficient.  I'll stick to V capitalized for now, I guess. 

My compliments on your working backward from dimension-units back to velocity for 1/k.   It is not how I would derive it of course, but bravo!  I've pounded that method into my students over the years to double check one's more straight forward physics (algebraic / calculus) symbolic inferences.  Again, Bravo!

I don't know if internally self-referential links are allowed but: http://forum.nasaspaceflight.com/index.php?topic=29276.msg1254645#msg1254645 is the link to my comment where I did the from-physics equation trace to conclude both V > 1/k criterion and V > 2/k full-system-voyage criterion.

Lastly, I'm not sure what 'crowing' has much to do with anything. A commenter seemed intent on introducing the pique of GoatGuy claiming victory somewhere else, and I felt the need to reposte. Perhaps it is impertinent. I'll learn in due time.

GoatGuy
Title: Re: EM Drive Developments
Post by: aceshigh on 09/17/2014 04:09 pm
well, maybe it´s a matter of text interpretation, and since you wrote it and claim it was something else, who am I to dispute? It just seemed to me it was "claiming victory" over the fact nobody had challenged your math

Quote from: GoatGuy
Well, if it is any consolation (and rebuttal to your position), no one has actually disagreed with my mathematics, over on Next Big NASA Fornum.

Indeed, the silence has been veritably deafening.
I do believe that half the people there believe I fârted in the Flower Show.
The other half daren't perk up 'cuz they know my knives are sharp.

LOL

GoatGuy


btw, you asked for me to post the link of the NBF discussion here
http://nextbigfuture.com/2014/09/paul-march-is-providing-more.html#comment-1592094709
Title: Re: EM Drive Developments
Post by: aceshigh on 09/17/2014 04:13 pm
and you can be as straightforward here as you are at NextBigFuture

Quote
Oh, please, RogerPenna … at least have a little more backbone than just to lecture me about the wrong way about having discourse on another forum. Since you apparently are good at reading, also note over yonder that I also said, "I'm not disclaiming the results, but rather, that the results imply a fundamental break in the laws of conservation, in Physics". (Paraphrased from 3 other comments I made.)

It is like this:

They - we have a marvelous new device that develops 51.7 µN with 2.73 watts of input microwave power.
Audience - yay! Cheers! WTG! Awesome!
Goat - (begins calculations from 51.7 µN and 2.73 W)
Goat - Yes, but that's 18.9 µN/W, and a 1/k of 52.8 km/s
Goat - Above which, kinetic energy is increasing faster than input energy.
Audience - Wait! What? Anyone know what Goat did wrong?
They - Well, its about Mach's Principle and moving the Universe.
Audience - See! You just don't know, Goat, anything but Newtonian Physics
Goat - That's nice, but my math, is still right. Its a perpetual motion machine
Audience - It doesn't matter: they're right and you're wrong.
Goat - Wait! What? How can the math be right, and wrong at same time?
They - You need to understand that conservation of energy is a Universe thing
Goat - Please, by all means, show the math
They - Its already been done. Do your own research.
Audience - Yah, take that, Goat.
Goat - Sigh… in other words, go on a goose chase, wade through a ton of abstruse math, figure out where they're fudging, come back, and lose everyone of the Audience in an abstract pedantic mathematical proof. Oh, that's rewarding. NOT.
Audience - Nya, nya, if you can't do it, why should we listen to you?
Goat - because, good reader, because the [V = 1/k] criterion is absolute.

And that's what you, Roger are missing. They have experiments which are claimed to produce a certain amount of thrust for a measured amount of input power. This comes out to newtons per watt. Using bog-standard Newtonian physics, I show that there will be a velocity above which more kinetic energy is being added to the physics package, than the amount of energy being poured into it. I further go on to state that at [V > 2/k], that the total amount of energy invested in the experiment from time=0 to whenever the V>2/k occurs … is less than the total amount of kinetic energy of the device.

This, as it turns out, requires the rewriting of Physics. Not just an eensy-weensy amount, but GIANT rewrite. Further, if the postulated practical levels of “k” are achieved (variously quoted as 1N/kW to even 10's of N/W), all power generation by any chemical, nuclear, geologic, renewable, or fossil source could be retired, and replaced with the magic reactionless thrusters. That's pretty sobering a rewrite of physics.

So, yah. I'm waiting for at least one of the physicists to say something other than a retort like, "well you explain how the experiments work then, Goat". I'm sorry, that's not good enough. I've presented a seriously important Physics objection that is quantitative, easily proven and dâmning to all of Physics, if true. It is not concomitant on me to prove this more than I have. It is concomitant on those who pander theory of an alternate reality, to bring forth the equally simple idea of where all the extra kinetic energy is coming from, in mathematically followable terms.

Jeez.

GoatGuy
Title: Re: EM Drive Developments
Post by: frobnicat on 09/17/2014 05:14 pm

According to a NASA contractor report, "the concept of accessing a significant amount of useful energy from the ZPE gained much credibility when a major article on this topic was published in Aviation Week & Space Technology (March 1st, 2004), a leading aerospace industry magazine".

For a destruction of several claims to tap energy from the zero-point quantum-vacuum see pages 65 to 80 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050170447.pdf]>>  http://en.wikipedia.org/wiki/Zero-point_energy

I don't see much destruction of claims from those pages, well written and interesting work but more like a rather neutral recollection of claims with attempts at finding unifying possible empirical and theoretical commonalities. What always strikes when looking the baroque history of such devices, from Tesla longitudinal scalar waves to ZPE reciprocating engines (going through fancy "ball lightnings"), is how it could be possible that of all these claimed results none of them could never ever make it to reproducible experiments in sceptics' labs and then into mainstream science's accepted results (even if not explained). There seems to always be a lost prototype, or an outraged genius forever keeping his recipe secret from those obtuse physicists, or a refused patent leading said genius to retirement in Antarctica, or someone with a 40Hp ZPE generator just keeping it in his basement and then seemingly forgetting about it presumably for more interesting achievements... And that not for years but for decades. I found it even more unbelievable that any of those effect were real (useful as claimed, regardless of theories) on the ground of sociology alone than from the critical stance of mainstream theories. Can't believe physicists at large are that obtuse, can't believe financial backers are that obtuse, can't believe it could be working and forever kept secret, ignored, forgotten.

Regarding security aspects and the c word, really not my cup of tea but I note that "research into successfully harnessing zero-point energy for energy generation purposes is a serious concern inside the intelligence community" from this paper (http://info.publicintelligence.net/USArmy-ZeroPointEnergy.pdf) (referenced by the wikipedia page) . Said paper is actually quite sceptic, while keeping eyes open on alternate views : "because it represents a high-risk/high pay-off technology..." which should be expected. From the near practical energy generation prospects alone, space drives should be somehow a concern to intelligence services.

I'm not saying or believing that it is the cause of limited/clumsy/strange communication strategy of the experimenters (from a mainstream open fundamental research point of vue). The accumulation of various experiments and claimed results through the years without exponential spread of a reproducible successful reference setup is more reminiscent of the long history of self deceiving failed attempts at harnessing something from nothing. That is not by itself a proof of the later results being wrong, neither the opinion of analysts, reality has the last word, but it's indicative.
Title: Re: EM Drive Developments
Post by: Rodal on 09/17/2014 05:54 pm
....
I'm not saying or believing that it is the cause of limited/clumsy/strange communication strategy of the experimenters (from a mainstream open fundamental research point of vue). The accumulation of various experiments and claimed results through the years without exponential spread of a reproducible successful reference setup is more reminiscent of the long history of self deceiving failed attempts at harnessing something from nothing. That is not by itself a proof of the later results being wrong, neither the opinion of analysts, reality has the last word, but it's indicative.

@frobnicat

Well, we can also look at this from the point of view of (Nobel Prize-winning) Irving Langmuir's definition of : http://en.wikipedia.org/wiki/Pathological_science, to see whether and how it meets the different characteristics of Pathological Science according to Langmuir:

(These answers to Langmuir's definitions are my personal opinions at this point in time, it will be interesting to see how other people would answer these points)

1) The maximum effect that is observed is produced by a causative agent of barely detectable intensity.

This is true for all the reported experimental results for EM drives from NASA's Eagleworks under Dr. White. The measured thrust is in the 20 to 110 microNewton range for all reported devices (Boeing/DARPA, Cannae and Frustum), hence it is "of barely detectable intensity."  (Also, the measurements were performed in an inverted torsional pendulum under magnetic damping, which is known to exhibit parasitic modes of excitation due to coupling of swinging with torsional modes.)

2) and the magnitude of the effect is substantially independent of the intensity of the cause.

No, this is not true, as the reported results vary with both the intensity of the cause and with physical orientation of the drive.

3) The effect is of a magnitude that remains close to the limit of detectability,

Yes, this was already addressed in #1 above.

4) or many measurements are necessary because of the very low statistical significance of the results.

Not enough measurements have been performed to make any statistical assessment of significance (from a frequentist -as opposed to Bayesian- statistical viewpoint)

5) There are claims of great accuracy.

No such claims from the NASA report.  Actually the report does not sufficiently address accuracy, in my opinion (concerning inverted pendulum known issues, see #1 above).

6) Fantastic theories contrary to experience are suggested.

Yes.  Three examples: A) [Dr. White] a MagnetoHydroDynamics model for the quantum vacuum, B) [Prof. Woodward] an unconventional Mach effect resulting in an “impulse” mass transient term and a second always-negative “wormhole” mass transient term, and C) [Prof. Brito] a Minkowski instead of an Abraham stress tensor explanation  (to name three different explanations that have been proposed).  "Conventional experience" has not  shown  A) translational momentum transfer imparted from (electron/positron pairs of) virtual particles from the quantum vacuum, B) transient changes in mass resulting from EM, and C) translational momentum imparted from EM explained in terms of (the unsymmetric) Minkowski 3D+time stress tensor  (without addressing "hidden momentum" as done by Poincare, Shockley and others).

7) Criticisms are met by ad hoc excuses.

Actually, I have not seen Dr. White respond to criticism from Prof. John Baez (Mathematics Department at U. C. Riverside), Sean Carroll (Sr. Research aAssociate in the Department of Physics at CalTech), etc.  Apparently, "confidentiality due to Non Disclosure Agreements" is claimed for the lack of response.

8 ) The ratio of supporters to critics rises and then falls gradually to oblivion.

Too early to tell regarding  the NASA Eagleworks latest report on "Anomalous thrust...".
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/17/2014 06:11 pm
Again, Bravo!

Thanks for all those bravos, but you failed to throw me any money!  Analogously, if diamonds are a girl's best friend, then the guy's best friend better be money.  And I need the money to get the girl.  But I digress...

But anyhow, thanks for that re-link.  That was the three pages I already printed.  Now I have to look at the rest of it to figger out all by my lonesome, how you got v=2/k.

I'm not complaining, mind you... except that I'm as lazy as the next non-mathemetician.

Quote from: goatGuy
Indeed, the silence has been veritably deafening.

Don't worry about crowing, but that's what it is.  Heck, I've dislocated my shoulder patting myself on the back for years.  Anyhow, 93143, who has taken me to task here and there, disagrees with your formulation:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1254700#msg1254700
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/17/2014 06:17 pm
Quote from: the oracle
Pathological science is the process by which "people are tricked into false results ... by subjective effects, wishful thinking or threshold interactions".[1][2] The term was first[3] used by Irving Langmuir, Nobel Prize-winning chemist, during a 1953...

'53 was a good year indeed.  I suggested investigating this to ol' Langmuir shortly after I was conceived.  Sciama too, BTW.

Whoops, gotta go...
Title: Re: EM Drive Developments
Post by: raketa on 09/17/2014 06:28 pm
I think cheapest and best way to prove, it will be build device that could be used on ISS(my understanding weight and power consumption are not overwhelming) and move it to ISS using one of the Dragon supply missions and tested on Orbit. I think in short time we will see if it is keeping ISS on same orbit or even raise orbit.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/17/2014 06:58 pm
And to think some people believe there's no point in building a bigger device to eliminate the doubt and skepticism about the source of the miniscule measurements on extremely fickle devices thus far.
Title: Re: EM Drive Developments
Post by: Stormbringer on 09/17/2014 07:00 pm
In one word: Starlite. In two words: Maurice Ward.  I think that about nips that line of argument.
Title: Re: EM Drive Developments
Post by: Rodal on 09/17/2014 07:01 pm
I think cheapest and best way to prove, it will be build device that could be used on ISS(my understanding weight and power consumption are not overwhelming) and move it to ISS using one of the Dragon supply missions and tested on Orbit. I think in short time we will see if it is keeping ISS on same orbit or even raise orbit.

Well, regarding this, it is interesting (for comparison purposes) that Dipole Magnetic (propellant-less) "propulsion" for positioning of satellite formation is being tested in the ISS:

see:  http://www.aero.umd.edu/news/news_story.php?id=7544

http://www.parabolicarc.com/2013/08/15/space-propulsion/

http://www.niac.usra.edu/files/studies/final_report/793Miller.pdf

http://ssl.mit.edu/publications/theses/PhD-2005-SchweighartSamuel.pdf

http://ssl.mit.edu/publications/theses/SM-2007-SakaguchiAya.pdf


People involved in this technology are discussing it (they are not claiming NDA's), for example see Ph.D and S.M. thesis at MIT above, and Prof. Ray Sedwick at University of Maryland .  One difference is that Dipole Magnetic propellant-less positioning of satellites relies on classical physics (no exotic physics like "quantum vacuum" or "transient changes in mass" is proposed to explain it) -so more "mainstream"-, and the work has been done at MIT and University of Maryland ?
Title: Re: EM Drive Developments
Post by: aero on 09/17/2014 07:09 pm
I think cheapest and best way to prove, it will be build device that could be used on ISS(my understanding weight and power consumption are not overwhelming) and move it to ISS using one of the Dragon supply missions and tested on Orbit. I think in short time we will see if it is keeping ISS on same orbit or even raise orbit.

I've got no problem with obtaining further (definitive) proof. Orbital decay of the ISS is like 2 km/month. If that is a velocity, then it is 7.716E-07   m/s which requires a continuous thrust of 350 mN to compensate. An EM thruster with that power should be achievable if results obtained in the lab are valid. Problem is, it would take years to prepare, schedule and then perform the experiment, all the while we are stuck with the debate of "it could work - no it couldn't - yes it could - no it can't, are you stupit ...

And hence never exploring any possible theories.
Title: Re: EM Drive Developments
Post by: raketa on 09/17/2014 07:28 pm
1887 Michelson–Morley experiment find very strange behavior that completely question current understanding of universe physic . After Einstein publish his theory and explain experiment everything was clear, it was  18 years after experiment.
I will not judge results of EMDrive until we could replicated or disapprove it by other tests. I think our understanding universe and fabric is still not very clear. If by some luck we could interact and use resources that build our universe, to move us around solar system, it is worth of couple millions to spend and it is definitely purpose of NASA  to do it. As I mention if other test replicate results,I will recommend to bring on ISS. This is exactly reason for ISS as orbital laboratory for space exploration.
Title: Re: EM Drive Developments
Post by: Rodal on 09/17/2014 08:51 pm
1887 Michelson–Morley experiment find very strange behavior that completely question current understanding of universe physic . After Einstein publish his theory and explain experiment everything was clear, it was  18 years after experiment.
I will not judge results of EMDrive until we could replicated or disapprove it by other tests. I think our understanding universe and fabric is still not very clear. If by some luck we could interact and use resources that build our universe, to move us around solar system, it is worth of couple millions to spend and it is definitely purpose of NASA  to do it. As I mention if other test replicate results,I will recommend to bring on ISS. This is exactly reason for ISS as orbital laboratory for space exploration.

The first experimental confirmation of Einstein's theory of General Relativity was the precession of the perihelion of Mercury, which was known much prior in time and yet was not satisfactorily explained up to that time.  Neither the "experiment" nor the "effect"  (the perihelion precession of Mercury) were in doubt.

Here, the NASA experimental results themselves involve very small measured forces (20 to 110 microNewtons) and have not yet been reproduced at JPL, Glenn or John Hopkins, for example.  The explanations for the measured forces involve exotic physics which do not (yet, at least) command the acceptance that Einstein's theory had (recall that Poincare, Minkowski, etc. had greatly contributed, and that Eddington, among several scientists, was a big supporter of Einstein's GR theory.)   Einstein was known to address criticisms of his theory (he did an excellent job doing that).  On the other hand, I have not heard NASA respond to criticism from Prof. John Baez, or from Sean Carroll at CalTech.  They claim they can't because of NDA's ?

Perhaps more to the point of propellant-less drives without classical external forces propelling it, there are cases as for example the case of Dean and Campbell who claimed that Newton’s laws of motion were only an approximation, and that Dean had discovered a fourth law of motion, described as a nonlinear correction to one of Newton’s laws, which, if correct, would allegedly have rendered a reactionless drive feasible.

<<His claims generated notoriety because, if true, such a device would have had enormous applications, completely changing human transport, engineering, space travel and more. Dean made several controlled private demonstrations of a number of different devices, however no working models were ever demonstrated publicly or subjected to independent analysis and Dean never presented any rigorous theoretical basis for their operation. Analysts conclude that the motion seen in Dean's device demonstrations was likely reliant on unsymmetrical frictional resistance between the device and the surface on which the device was set, resulting in the device moving in one direction when in operation, driven by the vibrations of the apparatus.>>

http://en.wikipedia.org/wiki/Dean_drive

The uncertainty in the scientific/technical community is what kind of effect this is... 
I don't know.  This is what we are discussing in this thread.  Should it be tested in the ISS or in a satellite ? (if it can indeed be scaled-up)? I'm not opposed to it.  Right now it is a question of whether there is a device that can be scaled-up and shown to produce a propulsion significant enough for detection in space (unless somebody can show that what has been shown ~50microNewtons for less than a minute operation is enough), and whether private funding for it or NASA support exists for such endeavor.  Actually, I don't even know whether Dr.White himself has campaigned for one of these devices to be tested in space.  My understanding (from his report) is that he is campaigning for independent testing at JPL, Glenn and John Hopkins.
Title: Re: EM Drive Developments
Post by: birchoff on 09/17/2014 09:01 pm
...
6) Fantastic theories contrary to experience are suggested.

Yes.  Three examples: A) [Dr. White] a MagnetoHydroDynamics model for the quantum vacuum, B) [Prof. Woodward] an unconventional Mach effect resulting in an “impulse” mass transient term and a second always-negative “wormhole” mass transient term, and C) [Prof. Brito] a Minkowski instead of an Abraham stress tensor explanation  (to name three different explanations that have been proposed).  "Conventional experience" has not  shown  A) translational momentum transfer imparted from (electron/positron pairs of) virtual particles from the quantum vacuum, B) transient changes in mass resulting from EM, and C) translational momentum imparted from EM explained in terms of (the unsymmetric) Minkowski 3D+time stress tensor  (without addressing "hidden momentum" as done by Poincare, Shockley and others).

...

Not sure if this particular check, so to speak, is a valid one. Given the breadth of human experience I would be willing to wager that if one was to limit research to only things humanity has experienced then it would not be practical for humanity to colonize the galaxy much less the entire universe. If memory serves there is nothing in the breadth of human experience up to the discovery of superconductivity that would have suggested that it was possible.

I personally think as far as our understanding of reality as human beings currently experience it is concerned we have a pretty solid grasp. But since humanity has only been exposed physically to a very small part of the universe I would further argue limiting ones consideration of new ideas to only that which has been experienced or could be easily experienced would be detrimental to our development.

That said, in regards to Woodward's work there is at least one example of FTL travel as I understand it; The big bang. The only questions that remain from my perspective is whether or not it is possible to manipulate space in a controlled manner? And can we do it without the need for the extraordinary conditions that existed at that point in time.
Title: Re: EM Drive Developments
Post by: birchoff on 09/17/2014 09:13 pm
I think cheapest and best way to prove, it will be build device that could be used on ISS(my understanding weight and power consumption are not overwhelming) and move it to ISS using one of the Dragon supply missions and tested on Orbit. I think in short time we will see if it is keeping ISS on same orbit or even raise orbit.

I keep seeing comments lobbying for a bigger scale experiment. When we don't even have a solid understanding of how either all of these class of propulsion devices work, or how each specific type works. All we have is a small set of positive results. Lets expand the pool of highly controlled positive results from a number of different testing protocols, executed by different labs first. Then when we have a solid understanding we can scale up to something that can power a cube sat. The only reason to do the cube sat test is to basically put a cherry on the already exquisitely prepared cake. Since you will most likely not have access to the necessary data logging you would need to feed the creation of a theory/model of how/why these things work, on top of whether or not we need to begin adjusting our long held beliefs about the laws of physics.

From my perspective I feel these types of comments keep getting raised because the authors want something to force the collective community to either take notice or prove them right. Shouldn't the onus now be on the critics. Shouldn't the critics be required to attempt a reproduction and publish their results, even if it is in Conference Proceedings.
Title: Re: EM Drive Developments
Post by: aero on 09/17/2014 09:23 pm
Quote
From my perspective I feel these types of comments keep getting raised because the authors want something to force the collective community to either take notice or prove them right. Shouldn't the onus now be on the critics. Shouldn't the critics be required to attempt a reproduction and publish their results, even if it is in Conference Proceedings.

Maybe in a perfect world, but not this one. See GoatGuy's proofs that it cannot work. That's a proof easy to do, all you need do is ignore one source of energy while claiming that your argument is complete. It doesn't help that there is no agreement on what that ignored energy source is and only those who have positive experimental results "know" that it does exist.
Title: Re: EM Drive Developments
Post by: Rodal on 09/17/2014 09:27 pm
Or that one cannot propel a sailboat using the wind or get energy from windmills...

Or propel a Solar Sail using the Sun or get a huge amount of energy from the Sun...:)
Title: Re: EM Drive Developments
Post by: aero on 09/17/2014 09:46 pm
Question: Does someone know what the diameter of the base of the NASA Tapered (Frustum) Cavity thruster is (was)?
Title: Re: EM Drive Developments
Post by: Rodal on 09/17/2014 09:56 pm
Question: Does someone know what the diameter of the base of the NASA Tapered (Frustum) Cavity thruster is (was)?
Good question, I would also like to know the dimensions of the Frustum and the Cannae devices tested at NASA.  Hopefully Paul March can answer.

In the interim perhaps you can guesstimate the dimensions from the photographs, using the fact that Paul March said that the total length of the pendulum arm (below the platform) was 24" with a 1.50" squarish cross section (Faztek) and they used this Faztek product in a number of other places.   "Faztek 15QE1515UL Aluminum 6063-16 T-Slotted Ultra Light Extrusion with Clear Anodize Finish, 1-1/2" Width x 1-1/2" Height" website:  http://www.faztek.net/technical.html
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/17/2014 09:58 pm
Maybe in a perfect world, but not this one. See GoatGuy's proofs that it cannot work. That's a proof easy to do, all you need do is ignore one source of energy while claiming that your argument is complete. It doesn't help that there is no agreement on what that ignored energy source is and only those who have positive experimental results "know" that it does exist.

Quickly:  I did not prove that it couldn't work, but rather that if it works then at some ΔV, the force is adding more kinetic energy than the electrical energy being invested.

This is V = 1/k   where k is N/W of specific force.

The second is ΔV = 2/k, which is where a free floating space-based, untethered device will have incurred more additional kinetic energy than all the electric energy fed to the thruster, from the beginning of the experiment.

Neither of these 'disprove' the existence of a thruster that achieves k = some number of newtons for some number of watts.  In the current context, Rodal and others are saying effectively, “there is a distant moving mass, that of the Universe, expanding in all directions (isotropically?); insofar as retaining the Holy Grail of Physics is concerned (either conservation of momentum, or conservation of energy, take your pick), Mach's Principle and Woodward's derivations postulate that the Universe's expanding mass is creating an Inertial Field, which is also in continuous expansion, and if this is true, then perhaps the impulse-energy and Q-thruster devices are conserving energy if the inertial field and Universe mass is brought into play”

I'm not even sure I paraphrased that correctly, but it meshes well with the snippets that people have gone so far either to quote, or to loosely infer.

To paraphrase more briefly:  If one includes the Universe's mass, and if that mass creates an inertial field, which travels both backward and forward in time at “c”, then deflecting that inertial field ought to deliver force independent of apparatus orientation, speed, or acceleration history, if it is Lorentz-transform invariant

Which is quite an amazing thing, if true.
Perhaps Rodal who's our physicist of note, will want to pitch in. 

GoatGuy
Title: Re: EM Drive Developments
Post by: Rodal on 09/17/2014 10:06 pm
... In the current context, Rodal and others are saying effectively, “there is a distant moving mass, that of the Universe, expanding in all directions (isotropically?); insofar as retaining the Holy Grail of Physics is concerned (either conservation of momentum, or conservation of energy, take your pick), Mach's Principle and Woodward's derivations postulate that the Universe's expanding mass is creating an Inertial Field, which is also in continuous expansion, and if this is true, then perhaps the impulse-energy and Q-thruster devices are conserving energy if the inertial field and Universe mass is brought into play”....
GoatGuy

Ha.  Are you serious? You can't be serious :)

For example, I'm the one that wrote:

[One of Langmuir's characteristic of PS]<<Fantastic theories contrary to experience are suggested.

Yes.  Three examples: A) [Dr. White] a MagnetoHydroDynamics model for the quantum vacuum, B) [Prof. Woodward] an unconventional Mach effect resulting in an “impulse” mass transient term and a second always-negative “wormhole” mass transient term, and C) [Prof. Brito] a Minkowski instead of an Abraham stress tensor explanation  (to name three different explanations that have been proposed).  "Conventional experience" has not  shown  A) translational momentum transfer imparted from (electron/positron pairs of) virtual particles from the quantum vacuum, B) transient changes in mass resulting from EM, and C) translational momentum imparted from EM explained in terms of (the unsymmetric) Minkowski 3D+time stress tensor  (without addressing "hidden momentum" as done by Poincare, Shockley and others).>>
___________

I won't say that the papers misquote me, but I sometimes wonder where Christianity would be today if instead of Matthew, Mark, Luke and John, we would have had reporters.

Barry Goldwater
Title: Re: EM Drive Developments
Post by: aero on 09/17/2014 10:08 pm
@GoatGuy
Thank you for that clarification. I note in passing that
Quote
To paraphrase more briefly:  If one includes the Universe's mass, and if that mass creates an inertial field, which travels both backward and forward in time at “c”, then deflecting that inertial field ought to deliver force independent of apparatus orientation, speed, or acceleration history, if it is Lorentz-transform invariant. 
may not be the only way to explain the positive result.
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/17/2014 10:21 pm
Or that one cannot propel a sailboat using the wind or get energy from windmills...

Or propel a Solar Sail using the Sun or get a huge amount of energy from the Sun...:)

Yes, yes … this is what I just commented on above.  The allusion has become something of a mantra:  there's an inertial wind, and all such force-for-power-input devices are simply catching the breeze, not unlike a sailboat's sail or a windmill's enshrouded spars.

But is there a relatively simple derivation of this (that doesn't require 3 years of symbolic calculus and a head-full of opaque assertions) that can be set to type?  I've seen simple, wordy accounts like I've just made, and I've seen 20 to 100 page papers.  I have yet to see something that can fit in a few pages, and which ordinary mortals with basic physics smarts can follow.  I welcome such a brief explanation; I mean that with honesty, and without rancor. 

Perhaps Rodal you have the goods?

GoatGuy
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/17/2014 10:31 pm

Ha.  Are you serious? You can't be serious :)

For example, I'm the one that wrote:

[One of Langmuir's characteristic of PS]<<Fantastic theories contrary to experience are suggested.

Yes.  Three examples: A) [Dr. White] a MagnetoHydroDynamics model for the quantum vacuum, B) [Prof. Woodward] an unconventional Mach effect resulting in an “impulse” mass transient term and a second always-negative “wormhole” mass transient term, and C) [Prof. Brito] a Minkowski instead of an Abraham stress tensor explanation  (to name three different explanations that have been proposed).  "Conventional experience" has not  shown  A) translational momentum transfer imparted from (electron/positron pairs of) virtual particles from the quantum vacuum, B) transient changes in mass resulting from EM, and C) translational momentum imparted from EM explained in terms of (the unsymmetric) Minkowski 3D+time stress tensor  (without addressing "hidden momentum" as done by Poincare, Shockley and others).>>

OK, I get it.  You're much to much a gentleman than to just outright call me an ignoramus.  That's fine.  I appreciate gallantry in the face of apparent stupidity. 

And I also appreciate the at least three conjectures, and the at least three missing predictions of those conjectures.  I'll further admit not having quite the math skills to take on debating the validity of any of the three conjectures, on their mathematical proof basis.

Do you see any of them that with your much higher mathematical/physics understanding hold water?  They cannot all be right of course. 

I may be an ignoramus, but I'll keep up the questions until the good professor tells me to shaddup.

GoatGuy
Title: Re: EM Drive Developments
Post by: aero on 09/17/2014 10:33 pm
Or that one cannot propel a sailboat using the wind or get energy from windmills...

Or propel a Solar Sail using the Sun or get a huge amount of energy from the Sun...:)

Yes, yes … this is what I just commented on above.  The allusion has become something of a mantra:  there's an inertial wind, and all such force-for-power-input devices are simply catching the breeze, not unlike a sailboat's sail or a windmill's enshrouded spars.

But is there a relatively simple derivation of this (that doesn't require 3 years of symbolic calculus and a head-full of opaque assertions) that can be set to type?  I've seen simple, wordy accounts like I've just made, and I've seen 20 to 100 page papers.  I have yet to see something that can fit in a few pages, and which ordinary mortals with basic physics smarts can follow.  I welcome such a brief explanation; I mean that with honesty, and without rancor. 

Perhaps Rodal you have the goods?

GoatGuy
If such a thing exists then Star-Drive is the one who would know. He would probably be the one who wrote it, as applied to the M-E thruster.
Title: Re: EM Drive Developments
Post by: Brett_Bellmore on 09/17/2014 10:34 pm
The only explanation I demand at this time is, "Eppur si muove".  Everything after that will just be detail. I just need to see it move a bit more clearly.

Once an unambiguous thrust signal is available, we can test it pointing in all directions, including up and down, at all times of day, at different altitudes, stationary and accelerating, on the ground and in orbit... We'll learn if it can be used as an over unity device or not, whether it's effected by the proximity of other masses, a lot of things.

Observational data is everything. Theory follows that. That's my view.
Title: Re: EM Drive Developments
Post by: aero on 09/17/2014 10:57 pm
I took dimensions of the Tapered (Frustum) Cavity thruster off the photo as suggested, using the 1.5 inch square beam end as reference. I got this in inches:
9.9 Major diameter, 6.6 Minor diameter, 9 Length.
It's probably a little bigger than that. I don't know how to deal with parallax.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/17/2014 10:57 pm
The only explanation I demand at this time is, "Eppur si muove".  Everything after that will just be detail. I just need to see it move a bit more clearly.

Once an unambiguous thrust signal is available, we can test it pointing in all directions, including up and down, at all times of day, at different altitudes, stationary and accelerating, on the ground and in orbit... We'll learn if it can be used as an over unity device or not, whether it's effected by the proximity of other masses, a lot of things.

Observational data is everything. Theory follows that. That's my view.

the problem I guess is that obviously, it's somewhat of a catch 21 isn´t it? Nobody will deposit the amount of funds needed to develop in a short amount of time the test devices, IF the theory is controversial and the thrust too small and doubted as noise signal.

and the theory (or theories) will not cease to be controversial while the thrust is too small to be perfectly detectable to the point of easily excluding any other source (when it's easily detectable at plain sight, it will be a question of finding an explanation to it, just as we know 90% of the mass of the universe is lacking, but can´t really explain it)

so, the only way to do it is to progress very slowly, with little funds available.

Title: Re: EM Drive Developments
Post by: Rodal on 09/17/2014 11:03 pm
I took dimensions of the Tapered (Frustum) Cavity thruster off the photo as suggested, using the 1.5 inch square beam end as reference. I got this in inches:
9.9 Major diameter, 6.6 Minor diameter, 9 Length.
It's probably a little bigger than that. I don't know how to deal with parallax.

Thank you, aero.  That's also helpful to me for my guesstimation purposes trying to figure out what effect is being measured. 
Title: Re: EM Drive Developments
Post by: John-H on 09/17/2014 11:12 pm
Well, it seems that IF we get the same thrust with the same energy input at some high velocity, then conservation of energy will be  violated. However, all we have seen so far is that we get thrust when the apparatus is at rest, and since there are very few observations, and no agreement on the theory, the thrust and power could easily vary in a way that satisfies established physics. There could be a new and useful effect there that doesn't break the laws of nature.

Or there could  be errors in the experiment.
Title: Re: EM Drive Developments
Post by: raketa on 09/17/2014 11:50 pm
I am electrical engineer and I understand how electric engine works. But if I start to think how in the reality these magnetic field interact and what make engine spin, I have admit I couldn't give you exact explanation. If we accept investigate just obvious facts, we will never build this type civilization. Your comment is similar to opposite comment just accepted that is working. We will see when follow experiment will be finish.

Quote
From my perspective I feel these types of comments keep getting raised because the authors want something to force the collective community to either take notice or prove them right. Shouldn't the onus now be on the critics. Shouldn't the critics be required to attempt a reproduction and publish their results, even if it is in Conference Proceedings.

Maybe in a perfect world, but not this one. See GoatGuy's proofs that it cannot work. That's a proof easy to do, all you need do is ignore one source of energy while claiming that your argument is complete. It doesn't help that there is no agreement on what that ignored energy source is and only those who have positive experimental results "know" that it does exist.
Title: Re: EM Drive Developments
Post by: cuddihy on 09/18/2014 02:28 am
The only explanation I demand at this time is, "Eppur si muove".  Everything after that will just be detail. I just need to see it move a bit more clearly.

Once an unambiguous thrust signal is available, we can test it pointing in all directions, including up and down, at all times of day, at different altitudes, stationary and accelerating, on the ground and in orbit... We'll learn if it can be used as an over unity device or not, whether it's effected by the proximity of other masses, a lot of things.

Observational data is everything. Theory follows that. That's my view.

Yes, ultimately. But in the meantime, it's important to deal with a theory of how it works to properly understand what a valid result is.

For instance, the first rigorous Woodward/ Mahood tests got thrust results -- but that did not scale as the "naive" theory said they should. Disproving Woodward's original hypothesis about the easiest way you could see a transisent mass fluctuation. (An assumption that micro-acceleration of atoms within a dieletric would be sufficient to cause a mass fluctuation--current theory says bulk acceleration of a substantial mass is required.)

Without the theory, Eppur si muove.

This initial failure has also raised the bar for Woodward in many sceptics' minds.
Title: Re: EM Drive Developments
Post by: aero on 09/18/2014 04:06 am
I took dimensions of the Tapered (Frustum) Cavity thruster off the photo as suggested, using the 1.5 inch square beam end as reference. I got this in inches:
9.9 Major diameter, 6.6 Minor diameter, 9 Length.
It's probably a little bigger than that. I don't know how to deal with parallax.

Shouldn't the cavity be the same diameter as the wave length of the resonate cavity? In any case, I calculate the wave lengths of the 3 frequencies used as
0.155123905 m = 6.107240338 inch
0.154795507 m = 6.094311291 inch
0.159430152 m = 6.276777642 inch

I guess I don't quite understand resonance.




Title: Re: EM Drive Developments
Post by: raketa on 09/18/2014 04:22 am
Device does not look too complicated, modify microwave. Most of the hassle is with creating environment that will not effect measured thrust.
I understand issue to bring it on the board of ISS, what about build simple version and place it in trunk of Dragon and tested after departure from ISS, keep Dragon for couple days on the orbit.
I think it could be achieve in year and we will have answer without doubt.
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/18/2014 05:31 am
At this point, I'm starting to wonder if some of the more hands-on inclined people here won't start building their own versions of these things in their garages.  From the photo's, the mechanisms themselves appear fairly simple, something a competent machinist could craft over a couple weekends. 
Title: Re: EM Drive Developments
Post by: raketa on 09/18/2014 08:31 am
I am just worry there is some know-how that is not publish about this device. And then you have hurdle to bring it to orbit. Maybe crowd funding could help build and launch it as cubesat. I will definitely help finance, to give chance dream to become solar system civilization.
At this point, I'm starting to wonder if some of the more hands-on inclined people here won't start building their own versions of these things in their garages.  From the photo's, the mechanisms themselves appear fairly simple, something a competent machinist could craft over a couple weekends.
Title: Re: EM Drive Developments
Post by: cuddihy on 09/18/2014 10:29 am
Again, the forces current devices exhibit is far less than small satellites see from solar pressure, drag, etc. So any effect would be hard to pull out, especially when you factor in the mass required to power it. Add in the complication that those forces are constant and these devices have only been tested for seconds at a time, it's a recipe for wasted money.
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 11:45 am
I took dimensions of the Tapered (Frustum) Cavity thruster off the photo as suggested, using the 1.5 inch square beam end as reference. I got this in inches:
9.9 Major diameter, 6.6 Minor diameter, 9 Length.
It's probably a little bigger than that. I don't know how to deal with parallax.

Shouldn't the cavity be the same diameter as the wave length of the resonate cavity? In any case, I calculate the wave lengths of the 3 frequencies used as
0.155123905 m = 6.107240338 inch
0.154795507 m = 6.094311291 inch
0.159430152 m = 6.276777642 inch

I guess I don't quite understand resonance.

Given the fact that you had to guesstimate the device's dimensions, the comparison between the wavelengths they used and the guesstimated diameters is not bad.  For the minor diameter: 

(6.6" Minor diameter)/(6.277 inch wavelength) = 1.051 ---> only 5% difference.

What do you think of the dielectric resonator influence ?

<<Tapered Cavity RF Evaluation, General.......The COMSOL analysis iteration process was used prior to assembly to determine the optimal thickness and diameter of the dielectric RF resonator disc located at the small end of the thruster. The geometry of the RF resonator disc is a function of the resonator material’s relative permittivity, dissipation factor, and target resonance mode.>> p.12

<<F. Tapered Cavity RF Evaluation, General Findings and Lessons Learned
Overall, the biggest lesson learned was that RF tuning and optimization constraints are very challenging. We discovered early in the COMSOL® analysis process that just because you can achieve a great RF solution does not mean that it will be an ideal Q-thruster implementation.
There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber. The geometry, location, and material properties of this resonator must be evaluated using numerous COMSOL® iterations to arrive at a viable thruster solution. We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust.>> p.18
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 12:51 pm
I have seen people in blogs (not in this thread) bringing up the dynamic Casimir effect as perhaps being responsible for the EM drive thrust.  One problem with the dynamic Casimir effect is that the moving mirrors responsible for the effect need to move at relativistic speeds.   If the moving mirrors move at a speed that doesn't approach the speed of light, the virtual particle pairs will easily adapt to the mirror’s movement and continue to come in and out of existence without any dynamic Casimir effectThe speed of the mirror needs to match the speed of the photons to experience the dynamic Casimir effect, and since the photons move at relativistic speeds, this means that the mirror needs to move at relativistic speeds.  If the mirrors move at speeds approaching the speed of light, then yes, the virtual photons then become "real" (in the sense that they will interact with the mirrors) and the mirror begins to produce light.  The problem is that it’s impossible to get an ordinary mirror made of solid matter moving at anything approaching relativistic speeds.  The walls of the Shawyer, Cannae and Dr. White Frustum microwave devices are certainly not moving at relativistic speeds.

Wilson et. al.  (arxiv.org/abs/1105.4714) used, instead of a conventional mirror made of solid matter, a transmission line connected to a superconducting quantum interference device (SQUID). The SQUID changes the effective electrical length of the line and this is equivalent to the movement of an electromagnetic mirror.  When modulating the SQUID at GHz rates, the "mirror" moves back and forth. The transmission line is only 100 micrometres long and the mirror moves over a distance of about a nanometre. It achieves speeds approaching 5 per cent of light speed. Then Wilson cooled the medium (to 50mK), so that the photons would travel slower and match the "mirror" speed.  This worked: it was the first experimental confirmation of the dynamic Casimir effect, they spotted microwave photons emerging from the moving mirror, as predicted some time ago to occur.

But I don't see how this can relate to what Shawyer, Cannae and Dr. White did with the Frustum device:  Wilson had to use a superconducting quantum interference device (which Shawyer, Cannae and Dr.White did not), modulated at GHz rates, and the transmission line was only 100 micrometres long, and everything had to be cooled down.   The walls of the EM drives are not moving at relativistic speeds, and they are several inches apart instead of a nanometer apart.  There are no "mirrors" moving at relativistic speeds,  about a nanometre apart.  And the EM drives experiments are not conducted in a medium at very low temperatures (50mK) to slow down the photons to match the "mirror's" speed.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/18/2014 01:39 pm
...
6) Fantastic theories contrary to experience are suggested.

 "Conventional experience" has not  shown  A) translational momentum transfer imparted from .. virtual particles from the quantum vacuum, B) transient changes in mass resulting from EM, [M-E, Mach Effect, I think, is what you meant] and C) translational momentum imparted from EM explained in terms of .. Minkowski 3D+time stress tensor

Not sure if this particular check, so to speak, is a valid one. Given the breadth of human experience I would be willing to wager that if one was to limit research to only things humanity has experienced then it would not be practical for humanity to colonize the galaxy much less the entire universe. If memory serves there is nothing in the breadth of human experience up to the discovery of superconductivity that would have suggested that it was possible.

We should have a sidebar discussion about the transient changes in mass suggested by Mr. Woodward's interpretation of Mach and Sciama's theories.  Maybe in it's own thread, IDK.

Anyhow, I think Birchoff's error is merely a grammatical one. Langmuir's item #6 regards more the insistence of proposing that a "fantastic theory" is true, and does not suggest, as you did, to "limit" human research.  Propose all the goofy theories you want, but do not insist that they are true on the basis of verbal assertion alone.

Bit of a quibble in that the "breadth of human experience" is pretty darn broad, beginning, I think, with the invention of the wheel.  Here, the innovation was the mental picture of harnessing a naturally observed rolling action to do "unnatural" things, such as rolling a load of manure from point A to point B.  Maybe, even this wasn't an innovation, since the dung beetle had been doing this for years before humans appeared on the scene.  By "unnatural things", I mean to suggest that the Ares I rocket is/was an "unnatural thing", because it was a construct of human imagination in its original conception.

In the case of M-E, either the phenomenon exists, or it does not.  It is unlikely that the phenomenon did not exist in the distant past, and was recently called into existance by the interpretation of Mach and Sciama's literature.  Point being, if humanity should use M-E for the "unnatural thing" of going to Luna, (fer cryin' out loud, quit all this stargate talk) it would "just" be an addition to the human experience.

I think you have to take all of Langmuir's items into consideration, and that you shouldn't separate one of them out.  YMMV, natch.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/18/2014 01:39 pm
All we have is a small set of thought to be positive results.

Fixed that for ya, and it doesn't detract from your argument in the least.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/18/2014 01:40 pm
In the current context, Rodal and others are saying effectively, “there is a distant moving mass, that of the Universe, expanding in all directions (isotropically?); insofar as retaining the Holy Grail of Physics is concerned (either conservation of momentum, or conservation of energy, take your pick), Mach's Principle and Woodward's derivations postulate that the Universe's expanding mass is creating an Inertial Field, which is also in continuous expansion, and if this is true, then perhaps the impulse-energy and Q-thruster devices are conserving energy if the inertial field and Universe mass is brought into play”

If the universe is expanding, then its mass must be increasing, and its energy must also be increasing.  If that is true, and a way can be figured out how to tap this increasing energy, then the effect would be to slow down the expansion of the universe.  But if there is an "inertial wind", then lo!  I am right in believing in the ether.

For example, I just got out of my chair and jumped up and down several times on the local planetary body, changing the universe ever so slightly, but changing it nevertheless.

Spare me the lesson about barycenters (http://en.wikipedia.org/wiki/Barycentric_coordinates_%28astronomy%29).  What I did is send out a rhythm of gravity waves which changes the inertial field of the same universe.

Point being, if this energy source could be tapped, it wouldn't change the universe all that much, at least at first.

Question being, can this be explained to a reasonably intelligent person?  Who might be an investor?  Right now, all of the explanations sound like those reporters who pestered Barry Goldwater.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/18/2014 01:40 pm
Are you serious? R U Sirius?

Fixed that for ya.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/18/2014 01:40 pm
..."Eppur si muove".  ...

Observational data is everything. Theory follows that. That's my view.

Hey!  One post.  One like!  Keep that rate up and you gonna be president!


Il problema è: nessuno pensa si muove.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/18/2014 01:41 pm
it's somewhat of a catch 21

22.  My work here is never done.
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 01:55 pm
...
6) Fantastic theories contrary to experience are suggested.

 "Conventional experience" has not  shown  A) translational momentum transfer imparted from .. virtual particles from the quantum vacuum, B) transient changes in mass resulting from EM, [M-E, Mach Effect, I think, is what you meant]

Well, I meant that conventional experience has not shown that ElectroMagnetic (EM) fields produce transient changes in mass (as posited by Woodward's interpretation of the Mach Effect), but however we word this you fully understood what I meant, and I agree with what you state in your latest post.  Woodward could answer that his effects are not meant to be conventionally experienced, but that's precisely what Langmuir was pointing out as one of the characteristics with which Langmuir identifies what he defines as Pathologic Science. So, if Woodward would answer that  his effects were never meant to be conventionally experienced, it would still meet that particular Langmuir characteristic with a "Yes".  By the way, Langmuir did not mean that something that meets his definitions of Pathological Science is necessarily bunk, or wrong, Langmuir just says "watch out," that if one is interested in the phenomena, further, more precise experiments need to be conducted by independent peers, before accepting the results.

Title: Re: EM Drive Developments
Post by: GoatGuy on 09/18/2014 01:59 pm
In the current context, Rodal and others are saying effectively, “there is a distant moving mass, that of the Universe, expanding in all directions (isotropically?); insofar as retaining the Holy Grail of Physics is concerned (either conservation of momentum, or conservation of energy, take your pick), Mach's Principle and Woodward's derivations postulate that the Universe's expanding mass is creating an Inertial Field, which is also in continuous expansion, and if this is true, then perhaps the impulse-energy and Q-thruster devices are conserving energy if the inertial field and Universe mass is brought into play”

If the universe is expanding, then its mass must be increasing, and its energy must also be increasing.  If that is true, and a way can be figured out how to tap this increasing energy, then the effect would be to slow down the expansion of the universe.  But if there is an "inertial wind", then lo!  I am right in believing in the ether.

For example, I just got out of my chair and jumped up and down several times on the local planetary body, changing the universe ever so slightly, but changing it nevertheless.

Spare me the lesson about barycenters (http://en.wikipedia.org/wiki/Barycentric_coordinates_%28astronomy%29).  What I did is send out a rhythm of gravity waves which changes the inertial field of the same universe.

Point being, if this energy source could be tapped, it wouldn't change the universe all that much, at least at first.

Question being, can this be explained to a reasonably intelligent person?  Who might be an investor?  Right now, all of the explanations sound like those reporters who pestered Barry Goldwater.

OK. no barycenter arguments.  It has been supposed there are gravity waves even in the one-man-jumping case, just too small to measure. 

Personally, I'd love for the thing to actually work somewhere above the 10s of millinewtons per watt level: at 10 mN/W, at the kilowatt level, this baby would make a hêll of a space thruster.  Not much for power generation down here.  That takes closer to newtons per watt, not millinewtons.   But the thought remains the same: if it works, well let's just rewrite physics in a simple enough way so that it can be taught to high-school physics newbies.

After all, the totality of Einstein's Special Relativity (a 50+ page paper) can be boiled down to about 10 equations, of which one is particularly memorable.  E = mc²

GoatGuy
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 02:18 pm
We should have a sidebar discussion about the transient changes in mass suggested by Mr. Woodward's interpretation of Mach and Sciama's theories.  Maybe in it's own thread, IDK.
Are you going to serve Scotch in this sidebar (as a motivator to join it) ?
Title: Re: EM Drive Developments
Post by: GoatGuy on 09/18/2014 02:36 pm
...
6) Fantastic theories contrary to experience are suggested.

 "Conventional experience" has not  shown  A) translational momentum transfer imparted from .. virtual particles from the quantum vacuum, B) transient changes in mass resulting from EM, [M-E, Mach Effect, I think, is what you meant]

Well, I meant that conventional experience has not shown that ElectroMagnetic (EM) fields produce transient changes in mass (as posited by Woodward's interpretation of the Mach Effect), but however we word this you fully understood what I meant, and I agree with what you state in your latest post

Woodward could answer that his effects are not meant to be conventionally experienced, but that's precisely what Langmuir was pointing out as one of the characteristics with which Langmuir identifies what he defines as Pathologic Science. So, if Woodward would answer that  his effects were never meant to be conventionally experienced, it would still meet that particular Langmuir characteristic with a "Yes". 

By the way, Langmuir did not mean that something that meets his definitions of Pathological Science is necessarily bunk, or wrong, Langmuir just says "watch out," that if one is interested in the phenomena, further, more precise experiments need to be conducted by independent peers, before accepting the results.

The part of Woodward's derivations that I have followed, but don't quite agree with is the magnitude of the increase in relativistic and/or potential mass associated with the oscillatory compression state (potential energy) of the dielectrics in his “inch-worm” thruster analysis.  Can't put my finger on it, but all the Δmc² inertial (or gravinertial?) effects seem many orders of magnitude lower than might be realized as net thrust.  Indeed, with the little math that I can throw around, it doesn't look much different than k = 1/c … which of course is exactly the electromagnetic emission case (un-enhanced by cavity Q theories)

GoatGuy
Title: Re: EM Drive Developments
Post by: bad_astra on 09/18/2014 02:46 pm
Again, the forces current devices exhibit is far less than small satellites see from solar pressure, drag, etc. So any effect would be hard to pull out, especially when you factor in the mass required to power it. Add in the complication that those forces are constant and these devices have only been tested for seconds at a time, it's a recipe for wasted money.

Rather than test at ISS or as a cubesat up front, a device could be tested on a stable high altitude balloon platform of the sort JP Aerospace makes. The test device at high altitude (not perfect vacuum of course), measure all outside movements, replicate at sea level. Compensate for variance. It would not be that expensive, certainly less than a 100k cube sat where all the variances could not be taken into account easily. This looks like a job for near-space.
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 02:57 pm
Again, the forces current devices exhibit is far less than small satellites see from solar pressure, drag, etc. So any effect would be hard to pull out, especially when you factor in the mass required to power it. Add in the complication that those forces are constant and these devices have only been tested for seconds at a time, it's a recipe for wasted money.

Rather than test at ISS or as a cubesat up front, a device could be tested on a stable high altitude balloon platform of the sort JP Aerospace makes. The test device at high altitude (not perfect vacuum of course), measure all outside movements, replicate at sea level. Compensate for variance. It would not be that expensive, certainly less than a 100k cube sat where all the variances could not be taken into account easily. This looks like a job for near-space.

Yes, that would be the logical step (after the Eagleworks results get verified at JPL, Glenn and John Hopkins), and something like that (but instead in a near Zero G aircraft parabola) is how the "propellant-less" Dipole magnetic flight formation  (explained by classical Maxwell equations, no-need-for-exotic physics) was tested before it was tested in the ISS.  See:  http://ssl.mit.edu/files/website/theses/SM-2013-BuckAlexander.pdf

Apparently, the "on-board-propellant-less" Dipole magnetic flight formation concept has made much more rapid progress (from lab to ZeroG to ISS experimentation) than these "on-board-propellant-less" EM drives...

Of course, the Dipole magnetic flight formation concept is such that the motion of the Center of Mass of the whole formation does not get changed by the formation's dipole magnetic forces (actually that is the purpose of operation) and certainly cannot be used to propel you to Enceladus...
Title: Re: EM Drive Developments
Post by: aceshigh on 09/18/2014 03:09 pm
it's somewhat of a catch 21

22.  My work here is never done.

well, considering it's an expression that makes no sense at all in other languages, I never used it before (in my natural language)
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 03:14 pm
it's somewhat of a catch 21

22.  My work here is never done.

well, considering it's an expression that makes no sense at all in other languages, I never used it before (in my natural language)
Well, consider that Joseph Heller began writing his novel "Catch 22" in 1953, which @JohnFornaro stated to be one of his favorite years... :)
Title: Re: EM Drive Developments
Post by: kch on 09/18/2014 03:26 pm
it's somewhat of a catch 21

22.  My work here is never done.

Somewhere, Sir Arthur Adding-one is smiling ...  ;)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/18/2014 03:32 pm
Are you going to serve Scotch in this sidebar?

I'm good for a bottle of 10yr Lapfrog... errrr... Laphroaig.

And izzat really true about Heller?  My vin du table is the Mouton Cadet Bordeaux.  Wonder if there's a bottle of the '53 kicking about?

The part of Woodward's derivations that I have followed...

Uhhh... which derivations, there, kemosabe?

Also, I'm working in the privacy of my own office to follow your v=2k argument. 

Just wanted to note that regarding that argument, silence is golden, and we're all getting rich.  Apparently.
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 03:44 pm

And izzat really true about Heller?  My vin du table is the Mouton Cadet Bordeaux.  Wonder if there's a bottle of the '53 kicking about?


Certainly, Ke-mo sah-bee, you can verify this here:

http://books.google.com/books?id=HC5nrYIo21IC&pg=PA140&lpg=PA140&dq=1953+heller+started+writing+catch+22&source=bl&ots=tYyYWNkFBB&sig=4SD2BQxdaHU_jPE7StyNrho-zcE&hl=en&sa=X&ei=-fwaVKSHD9HIggTJrYCIDg&ved=0CEAQ6AEwBA#v=onepage&q=1953%20heller%20started%20writing%20catch%2022&f=false

This is confirmed by Heller's own writings, in the Preface to his magnificent work, see
Page 140 of "Catch-22 - Joseph Heller, New Edition,  edited by Harold Bloom, Sterling Professor of Humanities Harold Bloom"

Or have you been reading Woodward instead of Heller ?
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 05:01 pm
And since we were discussing Heller, we might as well quote this famous Italian, that could equally apply to the experiments at Eagleworks ("the opponents, who have the laws on their side" means in this case the Physical Laws as presently understood by the Physics community at large):


<<It ought to be remembered that there is nothing more difficult to take in hand, more perilous to conduct, or more uncertain in its success, than to take the lead in the introduction of a new order of things.

Because the innovator has for enemies all those who have done well under the old conditions, and lukewarm defenders in those who may do well under the new.

This coolness arises partly from fear of the opponents, who have the laws on their side, and partly from the incredulity of men, who do not readily believe in new things until they have had a long experience of them.>>

The Prince

Niccolò Machiavelli   :)
Title: Re: EM Drive Developments
Post by: aero on 09/18/2014 05:12 pm
I have seen people in blogs (not in this thread) bringing up the dynamic Casimir effect as perhaps being responsible for the EM drive thrust.  One problem with the dynamic Casimir effect is that the moving mirrors responsible for the effect need to move at relativistic speeds.   If the moving mirrors move at a speed that doesn't approach the speed of light, the virtual particle pairs will easily adapt to the mirror’s movement and continue to come in and out of existence without any dynamic Casimir effectThe speed of the mirror needs to match the speed of the photons to experience the dynamic Casimir effect, and since the photons move at relativistic speeds, this means that the mirror needs to move at relativistic speeds.  If the mirrors move at speeds approaching the speed of light, then yes, the virtual photons then become "real" (in the sense that they will interact with the mirrors) and the mirror begins to produce light.  The problem is that it’s impossible to get an ordinary mirror made of solid matter moving at anything approaching relativistic speeds.  The walls of the Shawyer, Cannae and Dr. White Frustum microwave devices are certainly not moving at relativistic speeds.

Do we know that for sure? The walls are certainly not moving any macroscopic distance, and likely not even microscopic distance, but are they perhaps moving a "nanoscopic" (is that a word?) distance in sympathy with the RF driving power?
IIRC the skin thickness of copper is on the order of 100 nm. If the skin compresses and expands in sympathy with the driving force, and say its amplitude peak-to-peak was 100 nm, then what would the maximum velocity of the skin surface be? At 1900 Mhz, it would move through a complete cycle in 5.26 E-10 seconds. Oops, that's only 380 m/s on average, far from relativistic so you are right.
Quote

Wilson et. al.  (arxiv.org/abs/1105.4714) used, instead of a conventional mirror made of solid matter, a transmission line connected to a superconducting quantum interference device (SQUID). The SQUID changes the effective electrical length of the line and this is equivalent to the movement of an electromagnetic mirror.  When modulating the SQUID at GHz rates, the "mirror" moves back and forth. The transmission line is only 100 micrometres long and the mirror moves over a distance of about a nanometre. It achieves speeds approaching 5 per cent of light speed. Then Wilson cooled the medium (to 50mK), so that the photons would travel slower and match the "mirror" speed.  This worked: it was the first experimental confirmation of the dynamic Casimir effect, they spotted microwave photons emerging from the moving mirror, as predicted some time ago to occur.

But I don't see how this can relate to what Shawyer, Cannae and Dr. White did with the Frustum device:  Wilson had to use a superconducting quantum interference device (which Shawyer, Cannae and Dr.White did not), modulated at GHz rates, and the transmission line was only 100 micrometres long, and everything had to be cooled down.   The walls of the EM drives are not moving at relativistic speeds, and they are several inches apart instead of a nanometer apart.  There are no "mirrors" moving at relativistic speeds,  about a nanometre apart.  And the EM drives experiments are not conducted in a medium at very low temperatures (50mK) to slow down the photons to match the "mirror's" speed.

Your points seem quite reasonable to me, so I can rule out dynamic Casimir effect from my list of possible  causes of the measurement.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/18/2014 05:36 pm
Ol' Rodal there, friggin' rox!

Quote from: Rodal
And since we were discussing Heller, we might as well quote ... Niccolò Machiavelli

Who, as it turns out, has summarized the "typical" position of OldSpace vs. NewSpace:

"...fear of the opponents, who have the laws on their side..."

The ex-prez of ULA, MR. Gass, was at least forthright in his congressional admission that ULA "doesn't like competition".

But we digress from the matter at hand which is less about entrenched political interests, and far more about entrenched reality, which seems to most observers, to fly in the face of the innovators at hand.

The dimensional data of the testing apparatus has not yet been revealed by those who know.  In addition, the dimensions and cruciality of the Teflon resonator have yet to be addressed.  And to Rodal,  how crucial is the Teflon thingy to your larger argument regarding stray forces?

And of course, as all know, it is Larson's painstaking research which has taught us the meaning of the common useful term "kemosabe".

Oh.  And where's that bottle of wine I requested?  What am I paying you people to do around here?
Title: Re: EM Drive Developments
Post by: aero on 09/18/2014 07:26 pm
 
I've noted several times on this and other forums, I have the feeling that what we're seeing is a version of the Casimir force. At least that would be a local effect. The problem is that there are so many different Casimir force values for different situations.

Over the last few years their has been a surge in the study of Casimir forces and understanding is advancing rapidly. See the final remarks section, here:
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332006000700006 (http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332006000700006)

Quote
The Casimir effect has become an extremely active area of research from both theoretical and experimental points of view and its importance lies far beyond the context of QED. This is due to its interdisciplinary character, which makes this effect find applications in quantum field theory (bag model, for instance), cavity QED, atomic and molecular physics, mathematical methods in QFT (development of new regularization and renormalization schemes), fixing new constraints in hypothetical forces, nanotechnology (nanomachines operated by Casimir forces), condensed matter physics, gravitation and cosmology, models with compactified extra-dimensions, etc.

All of this research represents a doubled-edged sword. There are so many variations on the force that it is very time consuming to investigate. (Of course not as bad as having to develop the results one's self.) Here are some prominent areas where results exist, more or less.

1) The normal 2 parallel metallic plates F ~= -0.013/a^4 dyn/cm^2, where a is plate separation in micrometers.
2) The dynamic effect from a vibrating plate
3) The force on a body contained within a body
4) The force variation with the shape of the body
5) The force between a metallic plate and a parallel dielectric sheet
6) The effect of a magnetic field on the forces above.
And most likely others including the effect of the containment vessel (vacuum chamber).

Then of course there is the question of just how the imposed RF signal interacts with the various bodies.

Using measurements for the thruster from photos, and if one were to just assume without justification that the RF signal within the thruster behaves as a non-physical second metallic plate close to the base plate then the claimed thrusts agree closely with the 2 parallel plate Casimir force. (Plate separation about 0.917 micrometers, thrust error 0.005%)

I wish I could justify that assumption of the resonating RF energy acting as a virtual plate. The best I can do at the moment is to use the analogy of signal jamming. Suppose the applied RF signal jams the quantum electromagnetic field signal within the cavity. That, it seems to me would leave an unbalanced Casimir force on the plates and give rise to thrust from the device.   

Oh by the way, If I could justify that assumption, it immediately points to a better design with thrust values a lot higher. For example, shortening the length of the cavity to suppress resonates lengthwise and at the small end, leaving only one resonance mode at the large end. This would eliminate the negative Casimir force on the small end and on the sides of the cone leaving the force on the base plate as thrust.

And note how strongly Casimir force increases with smaller values of separation, a. If this were truly the cause of the measured thrust, then electronically moving the RF energy closer to the base plate causes thrust force to increase by four orders of magnitude for each lowering of the separation by one order of magnitude. That would be a payoff worth pursuing.
Title: Re: EM Drive Developments
Post by: raketa on 09/18/2014 07:27 pm
If EMDrive will work. I was thinking how much power will be needed to bring Mars closer to Sun, in some reasonable life span(20-30) Years.  It will be easier to terraform it if it will get more sun. Maybe this is question for new Topic.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/18/2014 07:35 pm
And since we were discussing Heller, we might as well quote this famous Italian, that could equally apply to the experiments at Eagleworks ("the opponents, who have the laws on their side" means in this case the Physical Laws as presently understood by the Physics community at large):


<<It ought to be remembered that there is nothing more difficult to take in hand, more perilous to conduct, or more uncertain in its success, than to take the lead in the introduction of a new order of things.

Because the innovator has for enemies all those who have done well under the old conditions, and lukewarm defenders in those who may do well under the new.

This coolness arises partly from fear of the opponents, who have the laws on their side, and partly from the incredulity of men, who do not readily believe in new things until they have had a long experience of them.>>

The Prince

Niccolò Machiavelli   :)

This entire discussion tangent is patently absurd. Skeptics of EM drives (those who aren't looking to write click-bait stories, at least) aren't looking to preserve the old order for their gain. These sorts of comparisons are laughably bad at best, and dogmatically polarizing at worst. Science is the derivation of facts, not a battle for the hearts of men!

Skeptics are skeptical because they want to be sure it's real, lest they be incredibly disappointed by the promise of another technology that did not do what they hoped, finding themselves needing to make embarrassing retractions, or spending a fortune on something that does nothing. There is not enough evidence to prove that the effects of EM drives are real, and until that evidence is gathered, it is everyone's due diligence to seek out flaws with the theory and the devices themselves.

It's a lot of fun to imagine what might be done with the technology, and I very much want it to be real, but we should all be operating under the assumption that EM drives appear to work because one thing or another about the experiments are wrong.
Title: Re: EM Drive Developments
Post by: aero on 09/18/2014 07:51 pm
Quote
It's a lot of fun to imagine what might be done with the technology, and I very much want it to be real, but we should all be operating under the assumption that EM drives appear to work because one thing or another about the experiments are wrong.

I agree its a lot of fun, but disagree that we should assume the experiments are wrong. That is simply dismissing the experiments.
Title: Re: EM Drive Developments
Post by: cuddihy on 09/18/2014 08:09 pm

The part of Woodward's derivations that I have followed...

Uhhh... which derivations, there, kemosabe?

Also, I'm working in the privacy of my own office to follow your v=2k argument. 

Just wanted to note that regarding that argument, silence is golden, and we're all getting rich.  Apparently.

Not exactly...Dont want to drag this Eagleworks thread further into a Woodward argument, but Woodward did address the "naive" formulation of how you would see a transient mass effect. He says you need more than a rapidly changing electomagnetic field, you also need bulk acceleration of a discrete mass in that field volume.

Where would you see that set of circumstances outside of man-made?
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 08:39 pm

 if one were to just assume without justification that the RF signal within the thruster behaves as a non-physical second metallic plate close to the base plate then the claimed thrusts agree closely with the 2 parallel plate Casimir force. (Plate separation about 0.917 micrometers, thrust error 0.005%)

I wish I could justify that assumption of the resonating RF energy acting as a virtual plate. The best I can do at the moment is to use the analogy of signal jamming. Suppose the applied RF signal jams the quantum electromagnetic field signal within the cavity. That, it seems to me would leave an unbalanced Casimir force on the plates and give rise to thrust from the device.   

Oh by the way, If I could justify that assumption, it immediately points to a better design with thrust values a lot higher. For example, shortening the length of the cavity to suppress resonates lengthwise and at the small end, leaving only one resonance mode at the large end. This would eliminate the negative Casimir force on the small end and on the sides of the cone leaving the force on the base plate as thrust.

And note how strongly Casimir force increases with smaller values of separation, a. If this were truly the cause of the measured thrust, then electronically moving the RF energy closer to the base plate causes thrust force to increase by four orders of magnitude for each lowering of the separation by one order of magnitude. That would be a payoff worth pursuing.

<< if one were to just assume without justification that the RF signal within the thruster behaves as a non-physical second metallic plate close to the base plate>>

Precisely, the problem with this line of reasoning, is that according to all our knowledge both from experiments and from Quantum Mechanics, an RF signal cannot behave as a second metallic plate.

Nobel Prize winner Julian Schwinger derived the Casimir effect as the attraction between plates due to a "retarded" van der Waal force: it is essentially due to charges.  There are no van der Waal forces with a RF signal.     Photons have no electric charge.  So whatever is responsible for the measured thrust of the microwave cavities tested at NASA is not what is known (from experiments and from Quantum Mechanics) as the Casimir effect. 

Schwinger's explanation of the Casimir effect is much more powerful than Casimir's explanation.  Schwinger's explanation predicts the correct sign for different geometries.  Casimir's explanation does not.  Furthermore Casimir failed at his attempt to predict the fine structure constant based on his explanation for the Casimir effect.  All our experimental and theoretical knowledge up to now points towards Schwinger's explanation being the better one.

See Jaffe's paper on the Casimir force:  http://cua.mit.edu/8.422/Reading%20Material/Jaffe2005_Casimir.pdf

<<When the plates were idealized as perfect conductors [by Casimir], assumptions were made about the properties of the materials and the strength of the QED coupling , that obscure the fact that the Casimir force originates in the forces between charged particles in the metal plates.>>

This is an excellent lecture, by Peter Milonni (who wrote the book on the Quantum Vacuum:  "The Quantum Vacuum: An Introduction to Quantum Electrodynamics"), on the Casimir effect. 

http://www.youtube.com/watch?v=12yjbyunRdM
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 09:29 pm
Watch that hockey stick  :)
Title: Re: EM Drive Developments
Post by: frobnicat on 09/18/2014 09:44 pm
Rodal could you tell us in a few words if Schwinger's explanation of the Casimir effect as originating from charge effects (more like van der Waals ...) discards the ZPE/vacuum turmoil playing any (direct) role in Casimir forces ? How the two explanations are linked, and how the "vacuum wavelength exclusion" effect serving the Casimir way of explaining the experimental results predicts correct magnitude for flat plates and not other geometries, as seen from this seemingly better framework ?

I should read the paper you linked rather than ask, but my reading queue is still encumbered with Matt Strassler's explanations about virtual particles (you know, 200 or 300 posts ago) and a few dozen other er, interesting things.

BTW if you feel pedagogically inclined and know the answer : from QFT, are the wave propagation speeds c for all the fields, including those that have massive associated particles ?
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 10:20 pm
Rodal could you tell us in a few words if Schwinger's explanation of the Casimir effect as originating from charge effects (more like van der Waals ...) discards the ZPE/vacuum turmoil playing any (direct) role in Casimir forces ?

<<The Casimir effect is often invoked as decisive evidence that the zero-point energies of quantum fields are ‘‘real.’’ On the contrary, Casimir effects can be formulated and Casimir forces can be computed without reference to zero-point energies. They are relativistic, quantum forces between charges and currents. The Casimir force (per unit area) between parallel plates vanishes as , the fine structure constant, goes to zero>> (  http://cua.mit.edu/8.422/Reading%20Material/Jaffe2005_Casimir.pdf  )

Just my understanding [*] (readers should do their own research and arrive at their own conclusions):

Yes in the restricted sense of rejecting a number of ideas like:

A) "negative energy" produced by the Casimir force,

B) "negative mass" produced by the Casimir force, and any number of "strange" ideas of people that see the Casimir force as something to enable stabilizing wormholes, faster than light travel with Alcubierre drives, etc.

C) Schwinger disagreed with a claim (by Scharnhorst and Barton) that light speeds greater than the speed of light in vacuum are possible in a parallel plate capacitor (the original Casimir effect geometry) .

On the other hand Schwinger saw the vacuum as being full of virtual particle pairs, and responsible for the Lamb shift. Also towards the end of his life he had some unusual ideas about cold fusion (http://www.lenr-canr.org/acrobat/SchwingerJcoldfusiona.pdf)

*** Schwinger was not the only one really bothered by "negative energy" and "negative mass" arising from Casimir's effect, also great physicists as Pauli, Feynman and DeWitt were just as bothered and said at different points in time that there was something wrong with Casimir's explanation, but Schwinger was the one that finally explained it, using Quantum Mechanics calculations, as being due to a retarded van der Waal force ****

_____________
[*] The debate is not closed.  For example Schwinger makes an adiabatic approximation assumption.

how the "vacuum wavelength exclusion" effect serving the Casimir way of explaining the experimental results predicts correct magnitude for flat plates ...?




A lucky intuition by Casimir.  In Casimir's own words "I went my own clumsy way"  His assumption works fine for plates, not for other geometries.  Failed in his attempt to predict the fine structure constant  (which is buried in Schwinger's explanation but practically disappears for flat plates) as due to the quantum vacuum.  This to me is critical: we know now that the fine structure constant, α, is a fundamental physical constant, namely the coupling constant characterizing the strength of the electromagnetic interaction between elementary charged particles.  It seems to me that those who use Casimir's explanation for the Casimir force not only fail at predicting the correct sign of the Casimir force for different geometries (which is bad enough) but also are lead to the idea that the fine structure constant can be predicted from the quantum vacuum, something that has been shown to be wrong.



BTW if you feel pedagogically inclined and know the answer : from QFT, are the wave propagation speeds c for all the fields, including those that have massive associated particles ?

I would have to think about that...
Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 11:03 pm
It is also interesting that in quantum electrodynamics (the theory used by Schwinger to calculate Casimir's effect), the fine structure constant α is the coupling constant determining the strength of the interaction between electrons and photons [*]. The theory does not predict its value. It must be determined experimentally. It is one of ~ 20 empirical parameters in the Standard Model of particle physics, whose value is not determined within the Standard Model.

______________
[*] Yes, in a powered microwave resonator we have photons and we also have electrons (as part of the atoms on the walls of the resonator).

Title: Re: EM Drive Developments
Post by: Rodal on 09/18/2014 11:21 pm
It is interesting how Schwinger's paper about cold fusion (http://www.lenr-canr.org/acrobat/SchwingerJcoldfusiona.pdf)  begins (he could have been talking about EM drives):


<<A totally unexpected phenomenon has been discovered in a certain field of science. It could have significant implications for the future of mankind, .... The overwhelming reaction of the experts in the field is rejection, based on the absence of other effects that are considered to be necessary companions of this new phenomenon. To quote one expert: “We know a lot about what happens. . . . We no longer have the latitude to say ‘Well, some strange event occurred and generated those things.’” Nevertheless, this new possibility seems to have enough validity that one skeptic said: “It’s hard to believe it. But there seems to be something to this.” And he went on to say: “It should not be necessary, however, to understand the mechanism before embracing the concept. If a proven track record can be established . . . you have to believe it.”>>
Title: Re: EM Drive Developments
Post by: aero on 09/18/2014 11:56 pm
Quote
[*] Yes, in a powered microwave resonator we have photons and we also have electrons (as part of the atoms on the walls of the resonator).

We have a lot of other stuff there too. Remember the experiments were in atmosphere. I won't guess as to how much the air in the cavity ionized or if such could have simulated the second metallic plate or to what effect.

Point is, the internals of the cavity and interactions are more complex than have been analyzed to date. Known physics may apply, I'm pretty sure, but we really don't know enough to claim correct application of applicable all known physics. Disregarding any unknown physics, but I'm willing to try to avoid unknown physics for now.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 02:05 am
Quote
[*] Yes, in a powered microwave resonator we have photons and we also have electrons (as part of the atoms on the walls of the resonator).

We have a lot of other stuff there too. Remember the experiments were in atmosphere. I won't guess as to how much the air in the cavity ionized or if such could have simulated the second metallic plate or to what effect.

Point is, the internals of the cavity and interactions are more complex than have been analyzed to date. Known physics may apply, I'm pretty sure, but we really don't know enough to claim correct application of applicable all known physics. Disregarding any unknown physics, but I'm willing to try to avoid unknown physics for now.

@aero

If the internals of the EM drive cavities matter, including internal cavity ionization, does it follow that if they were to repeat the tests in a vacuum chamber, your concerns still would apply, because you wouldn't know whether the cavity internals were properly evacuated?  (i.e. do we know whether the EM drive cavity is hermetically sealed or whether the cavity is very leaky?)
Title: Re: EM Drive Developments
Post by: aero on 09/19/2014 02:48 am
I got the impression that it leaked like a sieve, but don't know of any proof except for the absence of any information regarding air tight sealing. I do know this, quoting from Dr. White, et. al. report:

Quote
The thrust performance of this next generation tapered test article has been analytically determined to be in the 0.1 newton per kilowatt regime. Vacuum compatible RF amplifiers with power ranges of up to 125 watts will allow testing at vacuum conditions which was not possible using our current RF amplifiers due to the presence of electrolytic capacitors. The tapered thruster has a mechanical design such that it will be able to hold  pressure at 14.7 pounds per square inch (psi) inside of the thruster body while the thruster is tested at vacuum to  preclude glow discharge within the thruster body while it is being operated at high power.

That implies to me that the device we're discussing operated at atmospheric pressure. I've heard no mention of any different fill gas, so I assume air.

Edit: Actually, on Figure 22 is says, "In 750mm air" - Also, Figure 26 shows the dielectric they plan for their next generation RF thruster. It looks to me like it fills the cavity completely. I can't guess how much room there will be for air. Not much?
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 12:09 pm
Figure 26 shows the dielectric they plan for their next generation RF thruster. It looks to me like it fills the cavity completely. I can't guess how much room there will be for air. Not much?

1) The dielectric resonators must have been responsible for the NASA-measured thrust forces, for both the Cannae and the Frustum devices, as when they removed the dielectric resonators from either of them, they could not measure any thrust. 

2) The calculated Electric Field in the dielectric resonators is much, much stronger than in the rest of the cavity.

3) The volumes of the dielectric resonators are significantly smaller than the total inner volumes of the cavities.  One can assess the dielectric resonators relative size and location from Fig. 14, p.10, as the dielectric resonator appears red (in the Electric Field calculation display) surrounded by a narrow amount of yellow and a lot of blue.   Fig. 14 shows the PTFE (Teflon) dielectric resonator for the Cannae device.  It appears to have a cylindrical shape (small diameter/length ratio).  Fig. 26, p.21 showing the "Next Generation RF [Frustum] Thruster" shows an annular-shaped (a disc with an inner hole) dielectric resonator.  Yes, the annular-shaped dielectric resonator takes a significant amount of the area at the small diameter end of the Frustum, but it takes a rather insignificant amount of the total volume inside the cavity.

4) Notice the very un-symmetric location of the dielectric resonators.  For both the Cannae and the Frustum devices, the dielectric resonators are located towards one end of the device.  The direction of measured thrust is the same as the relative location of the dielectric resonator.  Defining "left" and "right" in fixed-in-space extrinsic coordinates: with the dielectric resonator located towards the right of the device's center of mass, thrust occurred towards the right.  When the device was turned around by 180 degrees such that the dielectric resonator was located towards the left of the center of mass, thrust occurred towards the left.

5) The picture of the Frustum seems to show a diameter ratio ( (large diameter)/(small diameter) ) = 1.71 instead of the guesstimated ratio ( (large diameter)/(small diameter) ) = 9.9"/6.6" = 1.50 based on the photograph and the cross-section of the Faztek beam.  Also the picture seems to show a  ( (large diameter)/(length) ) = 1.20 instead of the guesstimated ratio ( (large diameter)/(length) ) = 9.9"/9.0" = 1.10, and ( (length)/( small diameter) ) = 1.43 instead of the guesstimated ratio ( (length)/( small diameter) ) =  9.0"/6.6" = 1.36.  Therefore the ratios I guesstimate from this picture, divided by your guesstimated ratios are:  1.14, 1.09 and 1.05 respectively.  The differences are relatively small, the maximum difference being for the diameter ratio (14% difference between our estimates) and the smallest difference being for the estimation of the  ( (length)/( small diameter) ) ratio (5% difference between our estimates).  In any case, please double-check these dimensional ratios and let us know what you think.

______________________________________

Images from "Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum" by David A. Brady*, Harold G. White†, Paul March‡, James T. Lawrence§, and Frank J. Davies**, July 28-30, 2014, Cleveland, OH, AIAA 2014-4029, Propulsion and Energy Forum, 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

the article notes: "This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States." (Also see: http://en.wikipedia.org/wiki/Copyright_status_of_work_by_the_U.S._government) as posted in http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/19/2014 12:34 pm
Just a reminder that "analytical determination" is not the  equal of "experimental determination".

Solo dicendo.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 12:44 pm
Just a reminder that "analytical determination" is not the  equal of "experimental determination".

Solo dicendo.
I think that John is referring to the fact that the specific force of the Frustum was experimentally determined by NASA to be:

SPECIFIC FORCE=  0.003 N/kW to 0.0054 N/kW

So, an analytically determination that the future Frustum will have

SPECIFIC FORCE=0.1 N/kW

is an extrapolation by NASA that the future Frustum will have a specific force 19 to 33 times greater than the one experimentally measured.  I imagine that John is "solo dicendo" that it is unknown whether NASA's order of magnitude extrapolation will be realized in practice.

Solo riportati
Title: Re: EM Drive Developments
Post by: frobnicat on 09/19/2014 02:00 pm
More theoretical musing (at the risk of forking the discussion even more) :
In classical analytical understanding of systems, one can in principle always relate a macroscopic system wide effect to known microscopic elementary interactions in a given fundamental theory. While this is not always evident to show how a surprising/unforeseen macroscopic effect effectively derives from well known elementary theories (example superconductivity), it is always the case that the system's behaviours won't break the fundamental laws of its parts, in particular the conservation laws. Superconductivity kind of breaks the Ohm law (in the sense that a 0 resistance is both surprising from order/entropy arguments and technically problematic if deriving I=U/R) but Ohm law is an emergent effect for large systems, not a fundamental elementary theory. A macroscopic effect emergent on some particular geometry or bulk arrangement of parts can "break" some previously established emergent "law" but this is not the same as needing a different fundamental elementary theory of parts.

The "space drives" effects are measured at macroscopic scale and seems to require very specific arrangements of parts (geometry of atoms, parameters of RF photons...) otherwise it would probably have been observed numerous times in the past on macroscopic precision devices (accelerometers...). This is not shocking, superconductivity were never met before we gathered specific conditions (and even more very specific for hight temp. superconductivity)

The results indicate either a net deviation from energy-momentum conservation, or a need for exotic physics to explain how "net momentum from power" is observed locally but conserved globally (at Universe scale) without pushing on expelled known radiations (with at most 1/c thrust/power efficiency). Question is : how can this be addressed from an elementary point of view ? For the system to experience unheard of net momentum effects, then the parts would have to experience unheard of net momentum effects : the possibility of this new macroscopic effect implies the existence of new effect(s) at a microscopic scale (as contrary to Ohm law, momentum exchanges laws are elementary). This can't be just a matter of geometry, this should be understood at the level of particles -> and it should have empirically testable consequences on microscopic systems and elementary interactions. The number of degrees of freedom and conditions you can put a single particle (or a few atoms) are much less than for macroscopic shapes. If the thruster as a whole puts some of its parts at specific conditions, those can't be extreme conditions, space curvature, E/M field ... can't exceed what is routinely investigated in the lab (and in my microwave oven).

In such specific but presumably quite not exceptional microscopic conditions there should be an effect that is not part of contemporary admitted frameworks. But (but but) there seems to be no need for such : classical momentum exchanges between known particles(corresponding fields) at microscopic/instant places of the relativistic background of standard model (Feynman diagrams vertices if you like) seem to explain perfectly all precision measurements involving microscopic systems devoid of emergent phenomenons (because to small). How comes ? Would the microscopic counterparts of space drives effects be too small in magnitude to be distinguishable from SM's quantitative predictions ? Not sure I could do some meaningful order of magnitude comparison here but I find hard to believe. Experiments with ultracold atoms in RF/laser cavities comes to mind here, with tremendous energy levels/frequencies precisions... all in agreement with SM.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 02:26 pm
More theoretical musing ...
@frobnicat

Please take a look at my post above (with the images).  Do you have any comment on the known fact that NASA could not measure any thrust when they removed the small size (relative to the cavity) dielectric resonators?  They only measured thrust when the dielectric resonators were inside the EM drives.  Also, the measured thrusts forces pointed to the same direction (with respect to the center of mass) as the off-center positioning of the dielectric resonators.  Also, the (COMSOL finite element) calculations of the Electric Field showed the Electric Field to be orders of magnitude larger in the dielectric resonators than elsewhere in the EM drives.  Evidently the thrust measurements are foremost related to the dielectric resonators.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 02:36 pm
.. If the thruster as a whole puts some of its parts at specific conditions, those can't be extreme conditions, space curvature, E/M field ... can't exceed what is routinely investigated in the lab (and in my microwave oven)...
Yes, but, we do not have in our homes, our microwave oven positioned on an inverted torsional pendulum (known to exhibit parasitic modes of motion due to coupling of swinging with torsional motion) where we attempt to measure  microNewton torsional forces.  And we don't have a magnetic damper attempting to overdamp the motion of the inverted pendulum to attempt to eliminate parasitic modes of motion.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/19/2014 03:47 pm
.. If the thruster as a whole puts some of its parts at specific conditions, those can't be extreme conditions, space curvature, E/M field ... can't exceed what is routinely investigated in the lab (and in my microwave oven)...
Yes, but, we do not have at our homes, our microwave oven positioned on an inverted torsional pendulum (known to exhibit parasitic modes of motion due to coupling of swinging with torsional motion) where we attempt to measure  microNewton torsional forces.  And we don't have a magnetic damper attempting to overdamp the motion of the inverted pendulum to attempt to eliminate parasitic modes of motion.
Obviously but what I meant (I hope that was clear) is that the local (atom scale) conditions are mundane, from the point of view of an atom. And there is not that many much local configurations possible to consider in the vicinity of an atom, various superpositions of various freq EM radiations, gravity, gradients of those, what else ? And atoms, or small bunch of atoms, have been played around for quite some long in precision measurements devices to further the understanding and quantitative verification/use of microscopic fundamental frameworks. It should be possible to derive likely prediction of quantitative correction microscopic effects from the macroscopic empirical claim... don't know the relative magnitude though.

for your previous remark, if we are looking for classical explanations to the results, the dielectric part seems to play an important role. It could be because of the strong EM gradients there, non linearities maybe, maybe harmonics made there, maybe heat effects, maybe ionization, maybe different coupling with the generator (feedback of power to the generator). I can't propose any specific mechanism beyond what seems to have been addressed already. And even if the effect (as claimed) is bogus it's likely to be impossible to (classically) explain the results without a very close inspection of the experiment by third parties with fresh stance, a lot of time and instrumentation. Hope your attempts to model the mechanical aspects of the pendulum can further out the subject but I fear this won't settle much.

Clearly the presence of very strong magnets and induced currents in the damping system is not desirable. Wouldn't it be possible to devise a system of much much lower stiffness, with a natural swinging torsional motion period not shorter but longer than the experimental pulses (more than a minute), with no damping at all during the power on testing phases ?
I mean, an almost freely rotating thin strip torsion pendulum, slowly put into place (at the middle of fixed moving range), put to rest with active electrostatic control, and then off the control, check 0 speed for a little while, ok everything is stable, at equilibrium, and then measure rate of change of speed when powering on the device. Put all the device, with battery and RF generator (20W for a few minutes shouldn't weigh more than a few pounds) inside a good shielding conducting box inside a thick polystyrene box (or inside a dewar) to prevent any heat/EM exchange with exterior. And I would be happy with that setup even if not in a vacuum chamber but just an hermetic chamber, and very much more convinced if effects still hold.
( add maybe an active heat venting system, active only between power on sessions, so thermally isolated system wont melt in the long run )

Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 03:56 pm

Clearly the presence of very strong magnets and induced currents in the damping system is not desirable. Wouldn't it be possible to devise a system of much much lower stiffness, with a natural swinging motion period not shorter but longer than the experimental pulses (more than a minute), with no damping at all during the power on testing phases ?

Yes, of course, for example the hanging pendulum that has been used to get gravity (inverse square law) measurements, Casimir force measurements and many other types of sensitive measurements by the Physics community.   In a hanging pendulum gravity works as a stabilizing force, returning the mass to the center of swinging motion, so NO swinging stiffness is needed for the hanging pendulum.  That's how the pendulum of a Coo Coo clock works.  Gravity in an inverted pendulum works as a de-stabilizing force, making the mass go off-center. So an inverted pendulum needs swinging stiffness to keep the mass in the center.   Inverted pendulums need the magnetic dampening force to attempt to eliminate parasitic modes. 

 I imagine that NASA's Dr. White would reply that those hanging pendulums do not fit inside his small vacuum chamber, but I would answer that the reported NASA tests were not conducted in a vacuum anyway.

As I discussed in earlier posts, of the three places that NASA has proposed for further tests (JPL, Glenn and John Hopkins) I would be most interested in John Hopkins testing because it is reported to have a Cavendish type, hanging pendulum instead of the inverted pendulums that the NASA reports are considered at JPL and Glenn.  Also  as I discussed in earlier posts, Prof. Martinez-Sanchez at MIT has inverted pendulum thrust measurement devices at MIT that he designed to have the thruster horizontal at all times, to eliminate coupling of swinging modes with torsional modes.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/19/2014 04:16 pm
I imagine that John is "solo dicendo" that it is unknown whether NASA's order of magnitude extrapolation will be realized in practice.

Gazakly, might I abuse my own language.

Ohm law is an emergent effect for large systems, not a fundamental elementary theory.

I did not know that.  I thought it was not just a good idea, but that it was the law.

Quote
The "space drives" effects are measured at macroscopic scale and seems to require very specific arrangements of parts...

Which is why free dissemination of the geometry of the experimental apparatus is so crucial to the discussion at hand.

Quote
For the system to experience unheard of net momentum effects, then the parts would have to experience unheard of net momentum effects : the possibility of this new macroscopic effect implies the existence of new effect(s) at a microscopic scale ... This can't be just a matter of geometry, this should be understood at the level of particles ...

And I would add that theory must drive the design of the geometry.  Our alchemical ancestors, to bluntly summarize, played with pentagrams and other geometry, and used that mistakenly thought to be theoretical background to design and execute their experiments.  It turns out that one can change lead to gold, but only by using incredible amounts of energy as guided by theory.  The geometry of that transformative mechanism has nothing whatsoever to do with the ancestral primitive geometry.

Evidently the thrust measurements are foremost related to the dielectric resonators.

I cannot answer the question, but I remind all that this data is not yet in the public realm.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/19/2014 04:29 pm
Solo riportati

Solo riporto?  Don't know the idiomatic phrase.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 04:45 pm
Solo riportati

Solo riporto?  Don't know the idiomatic phrase.
I stand corrected, kemosabe

Solo riporto :)
Title: Re: EM Drive Developments
Post by: aero on 09/19/2014 04:58 pm
Here is a paper written to describe the Casimir energy between a metallic plate and a dielectric plate within a cavity. The configuration is somewhat similar to the Tapered Cavity tested at EagleWorks.

http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml# (http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml#)

I wonder if someone can help interpret this paper. To me, it does not seem consistent with what has been published elsewhere, in particular I see an unfamiliar term

Quote
where -pi/(24a^2) is the Casimir force between two ideal conducting plates separated by a.

But also this paper is developed in a reference system where c=1, h-bar=1. That is a common system but how does one convert the results into standard units of measure.

I forgot, if I ever knew how.
Title: Re: EM Drive Developments
Post by: RonM on 09/19/2014 05:06 pm
Here is a paper written to describe the Casimir energy between a metallic plate and a dielectric plate within a cavity. The configuration is somewhat similar to the Tapered Cavity tested at EagleWorks.

http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml# (http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml#)

I wonder if someone can help interpret this paper. To me, it does not seem consistent with what has been published elsewhere, in particular I see an unfamiliar term

Quote
where -pi/(24a^2) is the Casimir force between two ideal conducting plates separated by a.

But also this paper is developed in a reference system where c=1, h-bar=1. That is a common system but how does one convert the results into standard units of measure.

I forgot, if I ever knew how.

http://en.wikipedia.org/wiki/Speed_of_light (http://en.wikipedia.org/wiki/Speed_of_light)

http://en.wikipedia.org/wiki/Planck_constant (http://en.wikipedia.org/wiki/Planck_constant)
Title: Re: EM Drive Developments
Post by: aero on 09/19/2014 06:46 pm
Here is a paper written to describe the Casimir energy between a metallic plate and a dielectric plate within a cavity. The configuration is somewhat similar to the Tapered Cavity tested at EagleWorks.

http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml# (http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml#)

I wonder if someone can help interpret this paper. To me, it does not seem consistent with what has been published elsewhere, in particular I see an unfamiliar term

Quote
where -pi/(24a^2) is the Casimir force between two ideal conducting plates separated by a.

But also this paper is developed in a reference system where c=1, h-bar=1. That is a common system but how does one convert the results into standard units of measure.

I forgot, if I ever knew how.

http://en.wikipedia.org/wiki/Speed_of_light (http://en.wikipedia.org/wiki/Speed_of_light)

http://en.wikipedia.org/wiki/Planck_constant (http://en.wikipedia.org/wiki/Planck_constant)

Well yes I know that, but the author uses "1" in the equations derivation for each of these terms so where do I substitute the real values back into the end result to get real measurable values? Am I forced to carefully follow the derivation through to the end then know where the c's and h-bars go? (numerator, denominator, power, etc.)

Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/19/2014 07:19 pm
First post, bear w/ me, might be too far behind, or simplistic an inquiry.


1. If I imagine a coffee can (resonator w/ no velocity change?) sitting upright on a scale on my desk, and I fill it w/ a certain amount of photon energy, General Relativity would say that the can would become heavier by an amount equal to the "mass equvalent" of that energy. Presumably, the falling photons would gain energy and momentum and the rising ones would lose them. The momentum exchange w/ the upper and lower walls would give a difference force (weight) equal to the above.

(I imagine a "time dialation" explanation would work as well)

If an accelerating frame of reference (AFM) causes dispersion of the enclosed photons, is it unreasonable to expect a forced dispersion to create an AFM ???

2.  Somewhat more outlandish, if I imagine an enclosed spaceship, with it's own power supply and equipment on board to create electron/positron pairs and accelerate them in the direction of "thrust" such that they anihilate after a short distance and the doppler shifted radiation is captured, does that spaceship accelerate ???

I appologise for being so far behind, thanks.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 07:20 pm
Here is a paper written to describe the Casimir energy between a metallic plate and a dielectric plate within a cavity. The configuration is somewhat similar to the Tapered Cavity tested at EagleWorks.

http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml# (http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml#)

I wonder if someone can help interpret this paper. To me, it does not seem consistent with what has been published elsewhere, in particular I see an unfamiliar term

Quote
where -pi/(24a^2) is the Casimir force between two ideal conducting plates separated by a.

But also this paper is developed in a reference system where c=1, h-bar=1. That is a common system but how does one convert the results into standard units of measure.

I forgot, if I ever knew how.

http://en.wikipedia.org/wiki/Speed_of_light (http://en.wikipedia.org/wiki/Speed_of_light)

http://en.wikipedia.org/wiki/Planck_constant (http://en.wikipedia.org/wiki/Planck_constant)

Well yes I know that, but the author uses "1" in the equations derivation for each of these terms so where do I substitute the real values back into the end result to get real measurable values? Am I forced to carefully follow the derivation through to the end then know where the c's and h-bars go? (numerator, denominator, power, etc.)

<<ABSTRACT The Casimir effect between metal plate and dielectric plate is discussed with 1 + 1-dimensional potential model without using cut-off method. Calculation shows that the Casimir force between metal plate and dielectric plate is determined not only by the potential V,, , the dielectric thickness and the distance a between the metal plate and dielectric plate, but also by the dimension of the vessel. When a is far less than the dimension of the vessel, the Casimir force F~1/a ; conversely F~1/a^2.>>

This is my reading: it is a Chinese paper, using a Russian formulation to come up basically with the type of distance-dependence law involved, and they reach  the conclusion that it is an inverse law or an inverse squared law depending on the distance. 

They are not interested in deriving the actual magnitude of the force, and they do not derive the actual magnitude: all they are interested in is to state what kind of dependence it has, to contrast with the metal plates distance-dependence and the dielectric plates distance-dependence cases.
So, if my reading is correct, you cannot obtain the actual magnitude of the Casimir force for a given application from this paper.
_____________
They write <<In, the. 1 + 1-dimensional model, the vacuum fluctuations of the two modes of the electromagnetic field can be obtained by solving the massless one-dimension Klein-Gordon equation, ...,where h = c = 1>>

Take a look at http://en.wikipedia.org/wiki/Klein%E2%80%93Gordon_equation  and compare the dimensional Klein-Gordon equation with this paper's dimensionless equation

Basically, when they wrote h = c = 1 I stopped reading, since obviously, h[J s] and c [m/s] have different dimensions, so they cannot be equal, not just in magnitude but Joules*sec is a different dimension than meter/second.  If the authors wanted to conduct a non-dimensional analysis they should have specified more carefully what are the non-dimensionalized variables.

Title: Re: EM Drive Developments
Post by: aero on 09/19/2014 07:58 pm
@Rodal

Thanks for that. So what the paper shows is a very different Casimir force resulting from the containment vessel, (the cavity). But it doesn't show any reason to expect an unbalanced force giving the thrust. Ok, I'll keep looking if something else strikes me.

But it seems essential to include the RF waves in the equations somehow. I have found a way to do that (I think) but it requires some public domain software and 100 hours on a super computer. (Not very supper, only 1000 processors) still, that is 250 times more processors than I have on my machine, so the calculations would take me what, about 1000 days?

But I wouldn't know how to set up the models anyway.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 08:13 pm
@Rodal

Thanks for that. So what the paper shows is a very different Casimir force resulting from the containment vessel, (the cavity). But it doesn't show any reason to expect an unbalanced force giving the thrust. Ok, I'll keep looking if something else strikes me.

But it seems essential to include the RF waves in the equations somehow. I have found a way to do that (I think) but it requires some public domain software and 100 hours on a super computer. (Not very supper, only 1000 processors) still, that is 250 times more processors than I have on my machine, so the calculations would take me what, about 1000 days?

But I wouldn't know how to set up the models anyway.

Well, I would put it this way: they claim (based on their theoretical model --no experiments) that the vacuum chamber dimensions inside which the Casimir-experiment's metal and dielectric reside, affects the Casimir force.  They claim that when the distance between the metal and the dielectric is much smaller than the dimensions of the vacuum chamber , that the Casimir force between a metal and a dielectric is given by the inverse of the distance between the metal and the dielectric: the power of this inverse law is (-1) when they are a very small distance apart, and (-2) (an inverse square law) when they are further apart. 

Having said that, I have no idea how one could get any space-propulsion out of this.  Assuming that you trust this  paper, the force is attractive, and its only significance is for very small distances (as in nanotechnology). So if one wanted to create a nanotechnology mechanism comprising a dielectric and metal, this may be useful to let you know of stiction problems caused by the Casimir force.  But I don't understand how this minute attractive force for very small distances between the dielectric and the metal are going to result in space-propulsion of the macro-structure. 
Title: Re: EM Drive Developments
Post by: aero on 09/19/2014 08:36 pm
@Rodal  Neither do I. The materials are physically attached so the forces are all reacted via the structure.

Here are the references to the super computer application I referred to above, for anyone interested.

http://arxiv.org/abs/0904.0267 (http://arxiv.org/abs/0904.0267)

and

http://arxiv.org/abs/0906.5170 (http://arxiv.org/abs/0906.5170)

It too is useful at the nano scale, but at least it in in the time domain using Maxwell's equations.
Title: Re: EM Drive Developments
Post by: Stormbringer on 09/19/2014 08:40 pm
i don't know for sure but i assume that the thinking is that once you have the force manifest in space you can grab it and manipulate it. if it were negative if you push it it comes toward you. So you'd presumably push on it from the direction you want to go and then it would react by moving opposite of the force you applied. even better if it was subject to amplification.

however; the question (other than if any of that is really applicable; amplification and so forth) is can the equivalency of energy density differences actually fully operate as negative energy or mass for the purpose of a space drive.

Casimir force is just one speculative candidate for the source of negative energy and mass needed for most Warp or FTL schemes in accordance with the more esoteric GR solutions and space time metrics. There are others. E.G; Woodward wonders if you can separate the terms in  Mach's principle equation to reveal the naked negative mass of normal matter. none of them are currently probable but most are not well understood so there could be a surprise that makes them more realistic.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 08:59 pm
i don't know for sure but i assume that the thinking is that once you have the force manifest in space you can grab it and manipulate it. if it were negative if you push it it comes toward you. So you'd presumably push on it from the direction you want to go and then it would react by moving opposite of the force you applied. even better if it was subject to amplification.

Much more powerful than the Casimir force: an astronaut could bring a magnet inside his spacecraft.  On the way to Enceladus, he can reach for his suitcase inside which is his powerful magnet and point the magnet towards a  (hypothetical) steel structural framework inside his spacecraft.  The astronaut would feel a powerful force attracting the magnet and him towards the structure.  Even as the magnet moves the previously freely floating astronaut towards the steel structure, none of this will result in any translation of the center of mass of the spacecraft.  No translational propulsion of the spacecraft resulting from these  internal motions of the astronaut or the magnet.

So, the only way this could work as propulsion is if there would be a force attracting a metal (or dielectric) plate towards a particular direction in space.  But such a force is not the Casimir force.  There is a gravitational force: we are trying to get out of Earth's deep gravitational well, and we use the gravitational force of the planets to our advantage as a slingshot... There is the Solar Wind, and there is the Magnetic Field around the Earth. 
Title: Re: EM Drive Developments
Post by: aero on 09/19/2014 09:49 pm
The Casimir force is not really that "Small." For two parallel plates close together, the Casimir force:

F(a) = 0.013 *area/a^4 (dyn/cm^2) = 0.0013*area/a^4 (N/m^2) where a is the separation distance in micrometers.

Sure, for a = 1 micrometer, F(a) = 0.0013 N/m^2, but for a = 0.1 micrometer, F(a) = 13 N/m^2
and for a = 10 nanometers, F(a) = 130,000 N/m^2

But that is kind of beside the point. We know that for every action there is an equal and opposite reaction. The experiments have measured the reaction leaving us with the question, "What is the action?" Discounting "error" as one explanation, that leaves "Something not attached to but pushing on the thruster." 

I postulated an internal virtual metallic plate that caused the base plate or the thruster internally to react via the Casimir effect as though the virtual plate were there. So far, we can't find a mechanism to create this virtual plate. And real plates attached internally (or externally) would not cause an external thrust from the Casimir effect.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 10:04 pm
And we have the fact that the thrust measurements are related to the dielectric resonator. 

No dielectric resonator = no thrust force. 
Direction of thrust force --> direction in which dielectric is pointed towards.
Highest Electric Field (by orders of magnitude) --> in the dielectric resonator.

And we have an experimental setup where much larger, classical force fields are involved, at the macro scale.

I am not convinced that the conventional force fields and inertial forces involved have been adequately investigated to ascertain that they are not responsible for the measured thrust forces.
Title: Re: EM Drive Developments
Post by: aero on 09/19/2014 11:06 pm
Quote
I am not convinced that the conventional force fields and inertial forces involved have been adequately investigated to ascertain that they are not responsible for the measured thrust forces.

Did you mean "internal?" In any case, I concur. That thought is what led me to make my super computer post above. The approach given there may allow all fields to be evaluated in unison. (It may not, too.) But I personally am stymied by a lack of expertise and a lack of computing power, although it may be that the computing power needed is not as extensive as thought. It depends on the models after all.
Title: Re: EM Drive Developments
Post by: Rodal on 09/19/2014 11:16 pm
Quote
I am not convinced that the conventional force fields and inertial forces involved have been adequately investigated to ascertain that they are not responsible for the measured thrust forces.

Did you mean "internal?"

No, I meant inertial.   The thrust forces are measured in an inverted torsional pendulum that is known to exhibit parasitic motions due to coupling of torsional with swinging modes.  One of the coupling modes couples the inertia of swinging in one direction with the motion of swinging in the perpendicular direction, leading to a parasitic torsional force.  Another coupling mode couples the velocities of swinging motion (in perpendicular directions to each other) resulting in another parasitic torsional force.   Thus, torsional forces can be measured that are not due to a thrust from the EM drive.  They need to use magnetic damping to try to cancel these parasitic modes.  Magnetic damping may cancel the parasitic modes and/or may produce further parasitic modes.  This is why at MIT Aero & Astro the inverted pendulum is constructed such as to keep the thruster horizontal at all time, to eliminate these parasitic instabilities.
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/19/2014 11:50 pm
Quote
No, I meant inertial.   The thrust forces are measured in an inverted torsional pendulum that is known to exhibit parasitic motions due to coupling of torsional with swinging modes.  One of the coupling modes couples the inertia of swinging in one direction with the motion of swinging in the perpendicular direction, leading to a parasitic torsional force.  Another coupling mode couples the velocities of swinging motion (in perpendicular directions to each other) resulting in another parasitic torsional force.   Thus, torsional forces can be measured that are not due to a thrust from the EM drive.  They need to use magnetic damping to try to cancel these parasitic modes.  Magnetic damping may cancel the parasitic modes and/or may produce further parasitic modes.  This is why at MIT Aero & Astro the inverted pendulum is constructed such as to keep the thruster horizontal at all time, to eliminate these parasitic instabilities

Seems to me these issues with the inverted torsional pendulum could be suppressing genuine thrust.  IE, the problem cuts both ways.  On the one hand, a possible false positive; on the other a false negative, or at least a lower amount of thrust.

Maybe they should use actual scales for these tests?  Device weighs X amount when first placed on scales, if it generates thrust, then the weight changes.  Much more stable, less subject to forces creating false positives.   There must be some scales out in the world sufficiently sensitive for these tests.

Another thing I have been wondering about, especially given the requirement for an exact placement of the dielectric resonator:  maybe this really is some sort of 'microwave drive' that works because of its shape and placement of microwave source?  A sort of geometric loophole?  No invocation of exotic quantum mechanics or violation of conservation of momentum.  If so, would it still be useful in space?
Title: Re: EM Drive Developments
Post by: frobnicat on 09/20/2014 12:20 am
Another thing I have been wondering about, especially given the requirement for an exact placement of the dielectric resonator:  maybe this really is some sort of 'microwave drive' that works because of its shape and placement of microwave source?  A sort of geometric loophole?  No invocation of exotic quantum mechanics or violation of conservation of momentum.  If so, would it still be useful in space?
Not more useful in space than a photon rocket : well collimated microwave photons are not less efficient than visible light laser photons or xray photons, as far as thrust/power is concerned (at most 1/c, as usual). Since claimed thrusts are 3 order of magnitude higher, they can be explained either by
- radiation pressure building between device and chamber walls, effectively exchanging momentum with something else heavy nearby (so : not useful in space)
- exotic physics

It can't be both classical (not exotic) and useful in space (more than photon drive).

There is still the impractical possibility of using radiation pressure in space to have better than 1/c thrust/power and classical physics (not exotic) but that would imply bouncing photons (microwave or visible...) back and forth between two spacecrafts, or a spacecraft and a body (possibly a heavy body like a moon) to have a thrust separating them : the average number of times photons bounce (quality factor) would be a multiplicator for the thrust/power. So with very efficient mirrors so that a photon bounces 1000 times before being lost, thrust/power on the order of the Cannaes drive could be classically possible. But keeping the photons bouncing would not just be a matter of good mirrors, the main problem would be the limits of diffraction (mirrors diameters/wavelength > distance/mirrors diameters if I recall well, much superior if you want multiple bounces). As in beamed propulsion (laser driven sails) where one is already happy to have a single travel from source to target, only a 1000 times more "difficult" (read : mirrors wide as moons)

Title: Re: EM Drive Developments
Post by: ThinkerX on 09/20/2014 02:17 am
Quote
- radiation pressure building between device and chamber walls, effectively exchanging momentum with something else heavy nearby (so : not useful in space)

Sadly, this is the direction my thoughts are leaning at the moment.

Got to thinking of an analogy, using a hamster as a substitute for a subatomic particle:

1) Put hamster in ordinary cubical cage, he can bounce around all he wants and not budge the thing. 

2) But, put hamster in a small sphere - one of those plastic ball thingies - and he can go in pretty much any direction, barring obstacles.

3) Put hamster inside a sealed cylinder of about the same volume as the plastic ball, and he can go in two directions, but the cylinders shape won't allow for other movement.

Which got me to thinking that if this EM Drive works in space at all, it might be because of a very rough equivalent to option 3 with the hamster - it works because of its shape.  Yes they bounce around randomly on the inside, but the containers shape dictates that they strike with the greatest force in the direction you wish to move.  (Solid strikes 'forward,' tangential strikes to the side and back.) 

But that doesn't appear to be an option.

My other thought is some sort of 'Dark Matter' or 'Dark Energy' interaction - microwaves are cited in efforts to detect Dark Matter at least; maybe under the right conditions they could 'excite' Dark Matter or Dark Energy.  But that's just a wild guess.
Title: Re: EM Drive Developments
Post by: aero on 09/20/2014 02:32 am
Quote
My other thought is some sort of 'Dark Matter' or 'Dark Energy' interaction - microwaves are cited in efforts to detect Dark Matter at least; maybe under the right conditions they could 'excite' Dark Matter or Dark Energy.  But that's just a wild guess.

Don't be too concerned about posting a wild guess. I wonder how often good ideas start with a wild guess that evolves. A lot of the time, would be my wild guess.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/20/2014 02:53 am
Quote
My other thought is some sort of 'Dark Matter' or 'Dark Energy' interaction - microwaves are cited in efforts to detect Dark Matter at least; maybe under the right conditions they could 'excite' Dark Matter or Dark Energy.  But that's just a wild guess.

Don't be too concerned about posting a wild guess. I wonder how often good ideas start with a wild guess that evolves. A lot of the time, would be my wild guess.
I agree, but we are pushing things with dark hamster.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/20/2014 01:34 pm
I can't help thinking the "Dark Hamster" might be some sort of mechanism that acts like the "Pushme/Pullme" exploiting the difference between 2 areas (volumes) of different characteristic impedance.

On reflection, you need 3 in this case.

It's easy enough to think of the shear between the internal 2, but what couples to the outside?
You would need some mechanism that wants to "average" over the local free space ?

If radiation, then to maximize the P/E something that travels much less than c?
(the assumption is that acoustic radiation would be obvious to the experimenters ?)
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 01:49 pm
You can have a heck of a lot of hamsters walking inside a cylindrical spacecraft, and also pushing and pulling against its ends but the center of mass of the spacecraft is not going to translate at all.

The reason why the cylinder will rotate on a surface on Earth is because of gravity and friction between the cylinder and the surface.  Sorry, there ain't no friction against a fixed background when you are in space.  Just walking, pushing and pulling inside a spacecraft won't translate the center of mass of the spacecraft.  You can also play with a tennis ball against one of the spacecraft's walls and that still won't translate the center of mass of the spacecraft.  For the spacecraft's center of mass to move you have to let the tennis balls (or photons, or whatever) escape the spacecraft.
Title: Re: EM Drive Developments
Post by: RonM on 09/20/2014 01:54 pm
Here is a paper written to describe the Casimir energy between a metallic plate and a dielectric plate within a cavity. The configuration is somewhat similar to the Tapered Cavity tested at EagleWorks.

http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml# (http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml#)

I wonder if someone can help interpret this paper. To me, it does not seem consistent with what has been published elsewhere, in particular I see an unfamiliar term

Quote
where -pi/(24a^2) is the Casimir force between two ideal conducting plates separated by a.

But also this paper is developed in a reference system where c=1, h-bar=1. That is a common system but how does one convert the results into standard units of measure.

I forgot, if I ever knew how.

http://en.wikipedia.org/wiki/Speed_of_light (http://en.wikipedia.org/wiki/Speed_of_light)

http://en.wikipedia.org/wiki/Planck_constant (http://en.wikipedia.org/wiki/Planck_constant)

Well yes I know that, but the author uses "1" in the equations derivation for each of these terms so where do I substitute the real values back into the end result to get real measurable values? Am I forced to carefully follow the derivation through to the end then know where the c's and h-bars go? (numerator, denominator, power, etc.)

As Rodal wrote, h = c = 1 doesn't work because of the units. h = 1 and c= 1 are okay to run through simple calculations, but the variables must stay for deriving simplified equations.

You need to look at the derivation to see if the variables in question are cancelled out during the derivation. If they are, then you don't have to worry about them or their units.

If the authors immediately replaced the variables in question with 1 and then proceed to derive a simpler equation, their equation has nothing to do with the real world and is merely a mathematical exercise.
Title: Re: EM Drive Developments
Post by: RonM on 09/20/2014 02:13 pm
You can have a heck of a lot of hamsters walking inside a cylindrical spacecraft, and also pushing and pulling against its ends but the center of mass of the spacecraft is not going to translate at all.

The reason why the cylinder will rotate on a surface on Earth is because of gravity and friction between the cylinder and the surface.  Sorry, there ain't no friction against a fixed background when you are in space.  Just walking, pushing and pulling inside a spacecraft won't translate the center of mass of the spacecraft.  You can also play with a tennis ball against one of the spacecraft's walls and that still won't translate he center of mass of the spacecraft.  For the spacecraft's center of mass to move you have to let the tennis balls (or photons, or whatever) escape the spacecraft.

Yes, you have to either throw something out the vehicle (rocket exhaust) or interact with something external to the vehicle (rotating tires on a road).

Microwaves bouncing around a chamber will not result in a net force. Even if they were interacting with an external field, the different force vectors will cancel out, resulting in no net force.

Now if a device pushes against an external magnetic or gravitational field, or even virtual particle plasma (whatever that is supposed to be), it could produce thrust. Currently, magnetic propulsion is the only one we know how to do.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/20/2014 02:35 pm
Presumably, the "plasma" refers to the probability that a pair of photons can create an electron-positron pair which transfer some momentum and recombine as a doppler shifted pair   photons.

There's the rub.  The wavefunction for the interaction would have a wavelength  of the order of the difference in energy between the before and after photons, ie. much larger than the resonator.

Then too, one of the dark matter candidates has extremely low mass, (long wavelength) but no interaction ?
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 03:14 pm
.....
Then too, one of the dark matter candidates has extremely low mass, (long wavelength) but no interaction ?

Axions are predicted to change to and from photons in the presence of strong magnetic fields, and this property is used for creating experiments to detect axions.  Axions have no electric charge, a very small mass ( 10−6 to 1 eV/c^2 ), and very low interaction cross-sections for strong and weak forces. Axions interact only minimally with ordinary matter.

Given that (see previous post:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1256192#msg1256192)

1) even a photon rocket has orders of magnitude lower SpecificForce=thrust/InputPower than the reported experimental measurements and 2) to have net propulsion one has to have the photons escape one end of the device,

I don't follow how Axions could be responsible for the reported experimental measurements
Title: Re: EM Drive Developments
Post by: CW on 09/20/2014 03:22 pm
Here is a little thought experiment:

Imagine a perfectly reflective metal cavity, into which a photon from the outside is injected through a tiny hole in the cavity walls. When the photon hits the inner wall for the first time, it imparts 2x its impulse on the cavity (when being absorbed and then emitted again). Thus, the cavity gains a little momentum and moves a little bit into the photon's original impulse direction, aka translation. Then the reflected photon hits the opposite inner wall and effectively stops the cavity's movement again. But: Out metal box moved for a nanosecond or so, and hence the box has experienced a translational movement. At the same time, conservation of momentum was not violated: It's time-averaged ZERO. Still, we got a translation. Let's say the photon can be reflected for 1s overall within the cavity - that would mean we'd get 10^9 impulse impartings and thus translational movements within a 15cm length cavity (1ns per ping-pong). Not bad for a lonely photon ;) .

What do you think?
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 03:27 pm
Here is a little thought experiment:

Imagine a perfectly reflective metal cavity, into which a photon from the outside is injected through a tiny hole in the cavity walls. When the photon hits the inner wall for the first time, it imparts 2x its impulse on the cavity (when being absorbed and then emitted again). Thus, the cavity gains a little momentum and moves a little bit into the photon's original impulse direction, aka translation. Then the reflected photon hits the opposite inner wall and effectively stops the cavity's movement again. But: Out metal box moved for a nanosecond or so, and hence the box has experienced a translational movement. At the same time, conservation of momentum was not violated: It's time-averaged ZERO. Still, we got a translation.

What do you think?

1) In your model you assume that one end of the cavity is porous to photons but the other end is reflective

2) See previous post:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1256192#msg1256192)

Whether the photons could come from the outside and be reflected or whether they come from the inside and then make it out of the drive, the fundamental fact is that even a photon rocket has orders of magnitude lower SpecificForce=thrust/InputPower than the reported experimental measurements
Title: Re: EM Drive Developments
Post by: CW on 09/20/2014 03:29 pm
Here is a little thought experiment:

Imagine a perfectly reflective metal cavity, into which a photon from the outside is injected through a tiny hole in the cavity walls. When the photon hits the inner wall for the first time, it imparts 2x its impulse on the cavity (when being absorbed and then emitted again). Thus, the cavity gains a little momentum and moves a little bit into the photon's original impulse direction, aka translation. Then the reflected photon hits the opposite inner wall and effectively stops the cavity's movement again. But: Out metal box moved for a nanosecond or so, and hence the box has experienced a translational movement. At the same time, conservation of momentum was not violated: It's time-averaged ZERO. Still, we got a translation.

What do you think?

1) In your model you assume that one of the cavity is porous to photons but the other end is reflective

2) As per previous posts, even a photon rocket has specific force orders of magnitude lower than the reported values

Actually, in my model there is exactly one tiny hole in the whole cavity through which the photon(s) can be shot into. Also, a photon rocket only uses each photon once. In my model, one photon would be recycled by, say, 10^9 times. Orders of magnitude larger than a measly photon rocket :p . And this thing wouldn't work as a rocket at all - no impulse is imparted, but a translation. Translations don't violate conservation of momentum ;) .
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/20/2014 03:31 pm
I think the original photons momentum was transferred to the cavity.  The doppler shifted reflected photon is what now balances  forever in a lossless cavity.
Title: Re: EM Drive Developments
Post by: RonM on 09/20/2014 03:47 pm
I think the original photons momentum was transferred to the cavity.  The doppler shifted reflected photon is what now balances  forever in a lossless cavity.

Yes, the original photon adds to the system. After that, any reemitted photons zipping around are part of the system.
Title: Re: EM Drive Developments
Post by: CW on 09/20/2014 04:01 pm
I think the original photons momentum was transferred to the cavity.  The doppler shifted reflected photon is what now balances  forever in a lossless cavity.

Yes, the original photon adds to the system. After that, any reemitted photons zipping around are part of the system.

The point, that I wanted to make, was that a bouncing photon (that was injected externally) in a perfectly reflective cavity only gives the illusion of a continuous movement. In actuality, it is a go-stop-go-stop.. kind of motion.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/20/2014 04:09 pm
Not really, the photon speed is much higher than the speed of sound in the cavity walls.
Title: Re: EM Drive Developments
Post by: aero on 09/20/2014 05:17 pm
Well, what if it were electrons instead of photons? Somehow (help me out here) electrons originate in the dielectric, and are scattered in all directions by the high Q RF wave magnetic/electric fields. Electrons all speed to the conducting cavity walls and of course some of them travel axially toward the base plate. In the travel toward the base plate they encounter the resonating RF waves, one set of magnetic/electric fields resonating perpendicular to the end plates, another resonating parallel to the base plate.

Now will the magnetic/electric fields of the RF wave turn the direction of travel of the electrons such that they never reach the base plate but instead are turned to the side and neutralized on the metallic sides of the cavity? In that situation the side forces would average to zero but the end-to-end forces would transfer momentum to the thruster body.

Ok - the momentum originates in the electron acceleration from the dielectric by the RF energy which reacts with the cavity but are turned by the RF energy at the base which does not react with the cavity. hmm.
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 05:29 pm
Dr. White's hypothesis is precisely that electron/positron pairs of virtual particles emerge from the Quantum Vacuum and the EM drive behaves as a MagnetoHydroDynamics plasma.   Frobnicat, others and I have raised questions about that hypothesis.

It is a fact that has to be addressed by any  (classical or exotic)  explanation that:

No dielectric resonator = No measured thrust

Off center-of-mass position of dielectric resonator --> direction in which thrust is measured

Electrical Field in the dielectric resonator is orders of magnitude >> than in the rest of the cavity
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 05:42 pm
Well, what if it were electrons instead of photons? Somehow (help me out here) electrons originate in the dielectric, and are scattered in all directions by the high Q RF wave magnetic/electric fields. Electrons all speed to the conducting cavity walls and of course some of them travel axially toward the base plate. In the travel toward the base plate they encounter the resonating RF waves, one set of magnetic/electric fields resonating perpendicular to the end plates, another resonating parallel to the base plate.

Now will the magnetic/electric fields of the RF wave turn the direction of travel of the electrons such that they never reach the base plate but instead are turned to the side and neutralized on the metallic sides of the cavity? In that situation the side forces would average to zero but the end-to-end forces would transfer momentum to the thruster body.

Ok - the momentum originates in the electron acceleration from the dielectric by the RF energy which reacts with the cavity but are turned by the RF energy at the base which does not react with the cavity. hmm.

If that would work, wouldn't an Electron gun be more effective ? ( An electron emitter that produces a narrow, collimated electron beam as in cathode ray tubes (CRTs), used in older television sets, computer displays, and oscilloscopes. )  I disposed recently of a humongous high-definition CRT Sony TV (one of the last ones made) but I kept its electron gun  :)
Title: Re: EM Drive Developments
Post by: aero on 09/20/2014 06:27 pm
I prepared this post while you were making your post. Yes, in answer to your question.

Dr. White's hypothesis is precisely that electron/positron pairs of virtual particles emerge from the Quantum Vacuum and the EM drive behaves as a MagnetoHydroDynamics plasma.   Frobnicat, others and I have raised questions about that hypothesis.

It is a fact that has to be addressed by any  (classical or exotic)  explanation that:

No dielectric resonator = No measured thrust

Off center-of-mass position of dielectric resonator --> direction in which thrust is measured

Electrical Field in the dielectric resonator is orders of magnitude >> than in the rest of the cavity

Yes but Dr. White's theory comes up short with the assumption of electron/positron pairs. The positron, as I read the history of the theory development, is an electron moving backward in time postulated in order that the math will work to avoid infinite energies. That is, it is an artifact while the electron from the quantum vacuum is real. But irrespective of Dr. White's theory, I am postulating a 17 watt electron current originating in the dielectric and flowing to the cavity walls. This is like a CRT except instead of focusing the electron beam, the magnetic/electric fields within the cavity scatter the beam away from the base plate.

Newton's laws apply in my case, so for this to work, F = ma must be satisfied with F on the order of 50 - 100 muN and a single electron rest mass ~9 x 10^-31 kg. Of course a in this case is quite high. Guess the electron velocity is 3 x 10^6 m/s which is reasonable and non-relativistic. That gives a > 3.93701E+13 m/s^2 where the number is calculated assuming uniform acceleration across the cavity, dielectric to base plate. The result is that there must be 2.54E+12 electrons flowing.

But I will need to research to discover how to convert these flowing electrons to power. Power = 17 watts.
Title: Re: EM Drive Developments
Post by: aero on 09/20/2014 06:35 pm
Maybe I answered to quickly. What is the electron generation efficiency of a heated filament in a CRT compared to the electron generation/creation efficiency of the dielectric with the RF energy imposed? I don't know which would create more electrons using 17 watts of power.
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 07:44 pm
Some data:

Electric field shown in Fig. 14, titled "Cross section of test article (left) and close up of fields in RF drive pipe (right)", from the <<Computer modeling of the electric field within the pillbox and beam pipe (using COMSOL Multiphysics® software>>  of page 10 of 2014 JPC paper co-authored by Brady, White, et.al.

Maximum dissipated power in ("Teflon") PTFE dielectric resonator for Cannae device :

DissipatedPower = 2 Pi f (E^2) (permittivity of free space) (epsilon')(tan delta)

Taking the

maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m , and the given

frequency of 935 MHz, it immediately follows (for the Teflon PTFE dielectric resonator) that:


DissipatedPower per unit volume [W/m^3] = 2 Pi (935*10^6 1/s) (( 4.7189*10^4)^2) (8.85418782*10^(-12)) (2.1)(0.0003)

DissipatedPower per unit volume (in the dielectric resonator) =  72973  W/m^3 = 0.0729 W/cm^3

NonDissipatedPower per unit volume (in the dielectric resonator)~  243 W/cm^3

_____________________________________

Image from "Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum" by David A. Brady*, Harold G. White†, Paul March‡, James T. Lawrence§, and Frank J. Davies**, July 28-30, 2014, Cleveland, OH, AIAA 2014-4029, Propulsion and Energy Forum, 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

the article notes: "This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States." (Also see: http://en.wikipedia.org/wiki/Copyright_status_of_work_by_the_U.S._government) as posted in http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/20/2014 07:50 pm
DissipatedPower per unit volume =  72973  W/m^3 = 0.0729 W/cm^3

Is that just waste heat, just thrust, or waste heat and thrust?
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 07:51 pm
DissipatedPower per unit volume =  72973  W/m^3 = 0.0729 W/cm^3

Is that just waste heat, or is that waste heat and thrust?


This 0.0729 W/cm^3 is dissipated heat, that turns into an increase in temperature.   No comment about thrust.
Title: Re: EM Drive Developments
Post by: aero on 09/20/2014 08:00 pm
Ok, I used 17 watts in the following, so it will need to be reduced a little to allow for the dissipated heat power.

I calculated that the number of electrons,  2.54E+12 from before carry a charge of 4.07E-07 C so the current flow is 4.07E-07 amps. 17 watts of power, P = I*V gives Voltage across the cavity of 41.8 MV . This is a little higher (factor of 10 higher) than the striking voltage in air so glow discharge might be a problem.

Other than that, does physics allow this mechanism?

Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 08:06 pm
Ok, I used 17 watts in the following, so it will need to be reduced a little to allow for the dissipated heat power.

I calculated that the number of electrons,  2.54E+12 from before carry a charge of 4.07E-07 C so the current flow is 4.07E-07 amps. 17 watts of power, P = I*V gives Voltage across the cavity of 41.8 MV . This is a little higher (factor of 10 higher) than the striking voltage in air so glow discharge might be a problem.

Other than that, does physics allow this mechanism?

1) Thank you for performing calculations and providing numbers  :)
2) I have to think about this.
3) I look forward to other readers providing comments, performing their own calculations and cross-checking.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/20/2014 08:22 pm
I saw the talk about Dark Hamsters, and shall be going back to my beer soon.  Still:

In my model, one photon would be recycled by, say, 10^9 times.

Let's not, say, shall we?  You have given no cause to make that assumption.
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 09:22 pm
I saw the talk about Dark Hamsters, and shall be going back to my beer soon.  Still:

In my model, one photon would be recycled by, say, 10^9 times.

Let's not, say, shall we?  ...

We can't say "dicendo" anymore?   :)

Does that mean we can only say "solo" from now on ? Or is it only forbidden to "say" in English?
Title: Re: EM Drive Developments
Post by: aero on 09/20/2014 09:27 pm
Ok, I used 17 watts in the following, so it will need to be reduced a little to allow for the dissipated heat power.

I calculated that the number of electrons,  2.54E+12 from before carry a charge of 4.07E-07 C so the current flow is 4.07E-07 amps. 17 watts of power, P = I*V gives Voltage across the cavity of 41.8 MV . This is a little higher (factor of 10 higher) than the striking voltage in air so glow discharge might be a problem.

Other than that, does physics allow this mechanism?

1) Thank you for performing calculations and providing numbers  :)
2) I have to think about this.
3) I look forward to other readers providing comments, performing their own calculations and cross-checking.

You're welcome. I too hope that folks will comment based on knowledge of physics and also check the math.

As for the voltage being 10 times the striking voltage in air, I think that can be easily dealt with by modifying my assumptions. Reduce the electron velocity will decrease the electron acceleration, increase the current flow and reduce the cavity voltage. Alternatively, assume massive initial acceleration can maintain the thrust,  which will trickle through the math to change the voltage required for the power. Anyhow, to reduce the voltage for the fixed power, the current must increase. About a factor of 10 in both cases since power is linear with voltage and current.

The key is the question, can the accelerated electrons be turned by the RF waves in the cavity without acting on the base? And this is a question where consideration of the Q factor comes into play.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/20/2014 10:25 pm
Ok.  Just popped open Becks #4, so still functioning.

From:

The second case is a bit harder to prove, but still within reach of ordinary algebra:

Ek = ½mV²   ... kinetic energy as a function of V, again.
V = at ... again, now substitute
Ek = ½ma²t²  and remembering that [F = ma]...
Ek = F²t²/(2m)

If F = ma, then F^2 = (ma)^2 = m^2a^2, correct?

As to "solo dicendo"...

Yo no lo visto, ah. ah.
Yo no conozco, eh. eh.
Es peligroso... amore.

These guys in the song are brutalizing Spanish, are they not?  Wait a sec.  Beloved one tells me it's Italian:

"non l’ho visto, non lo cognosco, e pericoloso!!!!!!"

Yo no sabe nada.  ¿Estoy embrutecedor álgebra?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/20/2014 10:38 pm
"The key is the question, can the accelerated electrons be turned by the RF waves in the cavity without acting on the base? And this is a question where consideration of the Q factor comes into play."

Not sure about relevance, but probably more dependent on which cavity mode(s) than Q.
Title: Re: EM Drive Developments
Post by: aero on 09/20/2014 11:18 pm
@Rodal -
This is my concept of what a cathode ray tube converted to a thruster would look like. It is a static picture. In this case it seems like the electrons would strike the anode with the full vertical velocity and so would generate no external thrust. That would be so because the positive anode voltage had caused increased velocity by adding horizontal velocity. This turns the beam direction but does not react the vertical velocity. But the wall does.

So - can the RF wave turn the electron beam without adding velocity?
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 11:32 pm
@Rodal -
This is my concept of what a cathode ray tube converted to a thruster would look like. It is a static picture. In this case it seems like the electrons would strike the anode with the full vertical velocity and so would generate no external thrust. That would be so because the positive anode voltage had caused increased velocity by adding horizontal velocity. This turns the beam direction but does not react the vertical velocity. But the wall does.

So - can the RF wave turn the electron beam without adding velocity?

Did you notice that

A) the "Frustum" (or truncated cone)  smaller end surface appears to be metallic (copper?) but the Frustum larger end appears to be NOT-metallic (circuit-board polymer?)

B) the dielectric resonator is located right against the smaller end (copper?) surface

see Fig. 15 and Fig. 17 in the report:

_____________________________________

Image from "Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum" by David A. Brady*, Harold G. White†, Paul March‡, James T. Lawrence§, and Frank J. Davies**, July 28-30, 2014, Cleveland, OH, AIAA 2014-4029, Propulsion and Energy Forum, 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

the article notes: "This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States." (Also see: http://en.wikipedia.org/wiki/Copyright_status_of_work_by_the_U.S._government) as posted in http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/20/2014 11:43 pm
Circuit board material    2 layers
Title: Re: EM Drive Developments
Post by: Rodal on 09/20/2014 11:47 pm
Circuit board material    2 layers

Can you please elaborate or guess on purpose of Circuit board plastic "2 layers" instead of 1 layer ?
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/21/2014 12:02 am
Circuit board material    2 layers

So, glass reinforced plastic, with two intact copper layers inside?
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 12:13 am
Circuit board material    2 layers

So, glass reinforced plastic, with two intact copper layers inside?

How do we know that there are "two intact copper layers inside?"
Title: Re: EM Drive Developments
Post by: Bob Shaw on 09/21/2014 12:21 am
Guys, really! TANSTAAFL!

Let's stick with sensible stuff, like fully-reuseable return-to-launch-site boosters (with wings if possible)...
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 12:24 am
That circuit-board material on the larger end of the frustum cavity is not there by accident...
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/21/2014 12:25 am
Circuit board material    2 layers

So, glass reinforced plastic, with two intact copper layers inside?

How do we know that there are "two intact copper layers inside?"

I don't think we have a way of knowing for sure. Using PCB for the end of the thruster complicates things, since it's entirely possible for circuitry or antennas to be etched into the board's layers.

On the other hand, antennas would be odd, since microwave antennas use the quintessential parabolic dish. If nothing else, PCBs offer a uniform, flat, tough, and inexpensive copper surface.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 12:32 am
Guys, really! TANSTAAFL!

We ain't saying that there is any free lunch  ;)  On the contrary, we are trying to figure out what is paying the lunch ...
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 01:26 am
At breakdown, when the electric field exceeds the dielectric strength,  electrons are indeed released. If the applied electric field is sufficiently high, free electrons may become accelerated to velocities that can liberate additional electrons during collisions with neutral atoms or molecules in a process called avalanche breakdown.

The dielectric strength of PTFE ("Teflon") is 20*10^6 Volt/meter, but it decreases with increased frequency and with defects.

The reported calculations show that the electric field (maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m) was 400 times below the 20*10^6 V/m dielectric strength of PTFE ("Teflon").  On the other hand, if the Teflon dielectric resonator contained an unusual amount and size of defects, its dielectric strength could have been a fraction of that value.


 
Title: Re: EM Drive Developments
Post by: aero on 09/21/2014 01:56 am
At breakdown, when the electric field exceeds the dielectric strength,  electrons are indeed released. If the applied electric field is sufficiently high, free electrons may become accelerated to velocities that can liberate additional electrons during collisions with neutral atoms or molecules in a process called avalanche breakdown.

The dielectric strength of PTFE ("Teflon") is 20*10^6 Volt/meter, but it decreases with increased frequency and with defects.

The reported calculations show that the electric field (maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m) was 400 times below the 20*10^6 V/m dielectric strength of PTFE ("Teflon").  On the other hand, if the Teflon dielectric resonator contained an unusual amount and size of defects, its dielectric strength could have been a fraction of that value.

I'm reading the chart a little differently. Looks to me like the color bar on the left is for e-field values within the thruster while the color bar on the right is for e-field values within the RF drive pipe, hence the dielectric.  The color bar chart on the right has an over the top label of 3.5922 x 10^4 and red color label of 3000. But I don't know what it means as that layout is unfamiliar.

If IIUC, there is a mechanism where the RF wave in the dielectric can cause avalanche breakdown which will liberate huge numbers of electrons. But your reading of the available data is that the dielectric/RF wave interaction was selected to avoid that condition. Further, avalanche breakdown in the as specified dielectric is greater than 3 x 10^6 V/m, the striking voltage in air.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 02:27 am
At breakdown, when the electric field exceeds the dielectric strength,  electrons are indeed released. If the applied electric field is sufficiently high, free electrons may become accelerated to velocities that can liberate additional electrons during collisions with neutral atoms or molecules in a process called avalanche breakdown.

The dielectric strength of PTFE ("Teflon") is 20*10^6 Volt/meter, but it decreases with increased frequency and with defects.

The reported calculations show that the electric field (maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m) was 400 times below the 20*10^6 V/m dielectric strength of PTFE ("Teflon").  On the other hand, if the Teflon dielectric resonator contained an unusual amount and size of defects, its dielectric strength could have been a fraction of that value.

I'm reading the chart a little differently. Looks to me like the color bar on the left is for e-field values within the thruster while the color bar on the right is for e-field values within the RF drive pipe, hence the dielectric.  The color bar chart on the right has an over the top label of 3.5922 x 10^4 and red color label of 3000. But I don't know what it means as that layout is unfamiliar....

We know that the Fig.14 chart is an output from COMSOL's Multiphysics (http://www.comsol.com/) finite element analysis.  These are familiar, standard COMSOL finite element display of values.

The whole Cannae test article was most likely analyzed by COMSOL all-together: there was no separate analysis for the RF drive pipe (and if it were, for whatever reason as for example if they divided the analysis in "chunks" because of computer time, there would need to be compatibility and boundary condition requirements  enforced between the "chunks" as physically there is one physical problem to solve, as Maxwell's equations need to be solved over the whole domain).  Fig. 14 (left) is a COMSOL display of values for a plane revolving around the rotational axis (around which the pillbox geometry is defined).  Therefore Fig. 14 (left) does contain the Electric Field for the entire Cannae drive, including the "drive pipe", which is indeed being shown on that figure. The (COMSOL) finite element program always displays the maximum and minimum values that occur over the entire region being shown by COMSOL.   The maximum of the Electric Field is shown to occur in the dielectric. 

Fig. 14 (right) is a COMSOL display of particular circular cross-sectional areas perpendicular to the axis of revolution.  The purpose of showing Fig. 14 (right) is to show the distribution of the Electric Field in the rotational direction.  It shows that the Electric Field is practically rotationally symmetric.  Because only 7 cross-sections are shown, it is not surprising that the maximum value of the Electric Field will not appear on Fig 14 (right), such a discrete display (showing only 7 cross sections) must display a smaller value than a continuous display (such as Fig 14 left) unless the Electric Field happened to be uniform (constant) along the axis of revolution (in which case, if the field would have been constant in the axial direction, Fig 14 right would have displayed the same maximum as in Fig 14 left). 

Bottom line: I'm pretty sure that the maximum value of the COMSOL-calculated Electric Field in the dielectric is the one shown in Fig. 14 (left): 4.7189*10^4 V/m.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 02:54 am
At breakdown, when the electric field exceeds the dielectric strength,  electrons are indeed released. If the applied electric field is sufficiently high, free electrons may become accelerated to velocities that can liberate additional electrons during collisions with neutral atoms or molecules in a process called avalanche breakdown.

The dielectric strength of PTFE ("Teflon") is 20*10^6 Volt/meter, but it decreases with increased frequency and with defects.

The reported calculations show that the electric field (maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m) was 400 times below the 20*10^6 V/m dielectric strength of PTFE ("Teflon").  On the other hand, if the Teflon dielectric resonator contained an unusual amount and size of defects, its dielectric strength could have been a fraction of that value.

.....
If IIUC, there is a mechanism where the RF wave in the dielectric can cause avalanche breakdown which will liberate huge numbers of electrons. But your reading of the available data is that the dielectric/RF wave interaction was selected to avoid that condition.
In their report they express the fact it took them significant time to analyze the distribution of the Electric Field  and that realizing its importance (including the field in the dielectric) was among their most important achievements. 

Yes, at breakdown of the dielectric there could be an avalanche of electrons released. 

If (and only if):

A) their PTFE (Teflon) dielectric resonator was free of defects
B) their COMSOL calculations are accurate
C) the applied Electric Field was well controlled

then the tests should have been well below the breakdown point.

However those are assumptions that should not be taken for granted.  Even if the COMSOL calculations are accurate, we don't know how well was the electric field controlled in their set-up. 

Also, the result I quoted is for the Cannae drive.  They did not report the COMSOL numbers for the electric field in the frustum.

And also we don't know the quality of the PTFE dielectric resonators they used during their tests.  It is known that there is a huge range (particularly for a polymer like PTFE) of quality of PTFE in the market (Teflon is just DuPont's tradename).
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 03:43 am
At breakdown, when the electric field exceeds the dielectric strength,  electrons are indeed released. If the applied electric field is sufficiently high, free electrons may become accelerated to velocities that can liberate additional electrons during collisions with neutral atoms or molecules in a process called avalanche breakdown.

The dielectric strength of PTFE ("Teflon") is 20*10^6 Volt/meter, but it decreases with increased frequency and with defects.

The reported calculations show that the electric field (maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m) was 400 times below the 20*10^6 V/m dielectric strength of PTFE ("Teflon").  On the other hand, if the Teflon dielectric resonator contained an unusual amount and size of defects, its dielectric strength could have been a fraction of that value.

 Further, avalanche breakdown in the as specified dielectric is greater than 3 x 10^6 V/m, the striking voltage in air.

The breakdown of Air (3 x 10^6 V/m) doesn't appear to be as much of an issue as the COMSOL Electric Field calculations show the Electric Field in the cavity to be lower than 0.002 x 10^6 V/m, or 1500 times less than the Electric Field required for Air breakdown, so clearly the dielectric was about 4 times closer to breakdown than the Air.
Title: Re: EM Drive Developments
Post by: aero on 09/21/2014 03:45 am
So, bottom line is, "Yes, there is a possibility of the release of a large number of real electrons within the dielectric end of the thruster, via an electron avalanche." Such an electron avalanche was not a design feature of the thruster. And further, we know nothing definitive about the tapered cavity thruster.

Is there another mechanism which may have released electrons numbering in the ball park of 10^13 electrons/second? Note that is not a large number of electrons as such things go. The electron lifetime would be on the order of 10^-8 to 10^-9 seconds so at any given instant there only a few 10's of thousands of electrons within the cavity. That is a very small number as plasma densities go. Isn't it reasonable to assume that some small number of air molecules ionized within the cavity to create that small number of electrons?

Of course ionized air would result in positively charged ions also but if the cause of the electron acceleration was the magnetic field of the RF wave, then it would not discriminate between ion and electron acceleration forces. Ions would have a larger gyro radius around the magnetic field lines, and gyrate in the opposite direction (?) from the electrons but ultimately they would end up in the same place I think.

I'm on a roll here so I'd better stop before I go stupid on you.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 03:55 am
So, bottom line is, "Yes, there is a possibility of the release of a large number of real electrons within the dielectric end of the thruster, via an electron avalanche." Such an electron avalanche was not a design feature of the thruster. And further, we know nothing definitive about the tapered cavity thruster.

Is there another mechanism which may have released electrons numbering in the ball park of 10^13 electrons/second? Note that is not a large number of electrons as such things go. The electron lifetime would be on the order of 10^-8 to 10^-9 seconds so at any given instant there only a few 10's of thousands of electrons within the cavity. That is a very small number as plasma densities go. Isn't it reasonable to assume that some small number of air molecules ionized within the cavity to create that small number of electrons?

Of course ionized air would result in positively charged ions also but if the cause of the electron acceleration was the magnetic field of the RF wave, then it would not discriminate between ion and electron acceleration forces. Ions would have a larger gyro radius around the magnetic field lines, and gyrate in the opposite direction (?) from the electrons but ultimately they would end up in the same place I think.

I'm on a roll here so I'd better stop before I go stupid on you.

It depends on a lot of things, like the amount of polarization that is achieved in the PTFE dielectric resonator.

This we know: there was no measurable thrust when they removed the PTFE dielectric resonator and the direction of the thrust correlates with the location and polarization of the dielectric resonator.
Title: Re: EM Drive Developments
Post by: aero on 09/21/2014 04:30 am
So, bottom line is, "Yes, there is a possibility of the release of a large number of real electrons within the dielectric end of the thruster, via an electron avalanche." Such an electron avalanche was not a design feature of the thruster. And further, we know nothing definitive about the tapered cavity thruster.

Is there another mechanism which may have released electrons numbering in the ball park of 10^13 electrons/second? Note that is not a large number of electrons as such things go. The electron lifetime would be on the order of 10^-8 to 10^-9 seconds so at any given instant there only a few 10's of thousands of electrons within the cavity. That is a very small number as plasma densities go. Isn't it reasonable to assume that some small number of air molecules ionized within the cavity to create that small number of electrons?

Of course ionized air would result in positively charged ions also but if the cause of the electron acceleration was the magnetic field of the RF wave, then it would not discriminate between ion and electron acceleration forces. Ions would have a larger gyro radius around the magnetic field lines, and gyrate in the opposite direction (?) from the electrons but ultimately they would end up in the same place I think.

I'm on a roll here so I'd better stop before I go stupid on you.

It depends on a lot of things, like the amount of polarization that is achieved in the PTFE dielectric resonator.

This we know: there was no measurable thrust when they removed the PTFE dielectric resonator and the direction of the thrust correlates with the location and polarization of the dielectric resonator.

That's fine then. Due to the small number of electrons needed, we don't really need an avalanche, just some "modest" level of ionization within the dielectric resonator. Unfortunately, didn't I read that they have plans to change the dielectric for the IV&V thruster models?
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 08:44 am
That's fine then. Due to the small number of electrons needed, we don't really need an avalanche, just some "modest" level of ionization within the dielectric resonator. Unfortunately, didn't I read that they have plans to change the dielectric for the IV&V thruster models?

<<Moving forward, a new tapered cavity RF resonance system has been designed and characterized using COMSOL® with Q-thruster physics. Figure 26 shows some of the COMSOL® analysis with the higher performance dielectric resonator clearly visible. This resonator material has a relative permittivity that is an order of magnitude higher than our current tapered cavity test article resonator material. The lessons learned with antenna design and location have been factored in and the design of both the drive and sense antennas have been explicitly optimized to excite the RF thruster at the target frequency and mode (e.g., the optimal location has been analytically determined). The thrust performance of this next generation tapered test article has been analytically determined to be in the 0.1 newton per kilowatt regime.>>
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/21/2014 01:37 pm
[quoting another]This resonator material has a relative permittivity that is an order of magnitude higher than our current tapered cavity test article resonator material...
[/quote]

Compressed hummingbird wings? (Which is real)  Ground unicorn horns? (Which is fake)

Always a mysterious special sauce, it would seem.

Seriously tho, you guyz have lost me with the sidetrack about your all's analysis of the dimensionless PTFE and the nature of the Comsol modeling, now expected to accomodate a new material.  Like I always say:

Ausência de evidência é evidência de ausência de evidência.

But enough talk about you.  Let's talk about GoatGuy's math.  I don't think it's correct.  Lemme try again.

The second case is a bit harder to prove, but still within reach of ordinary algebra:

Ek = ½mV²   ... kinetic energy as a function of V, again.
V = at ... again, now substitute
Ek = ½ma²t²  and remembering that [F = ma]...
Ek = F²t²/(2m)

If F = ma, then F^2 = (ma)^2 = m^2a^2, correct?

GoatGuy doesn't write that.  Instead he writes:

Quote from: goatGuy
Ek = ½ma²t²

How did he get from Ek = ½ma²t² to Ek = F²t²/(2m)?

Apenas dizendo.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 02:02 pm
you guyz have lost me
Apenas dizendo.

For those having difficulties following the recent discussion between aero, RotoSequence, Notsosureofit and me, we have been analyzing the possibility (among many possible explanations) that the anomalous thrust experimental results may have been due to (unintended) field emission of electrons from the ("Teflon") PTFE dielectric resonator (acting as an unintended electron rocket with Teflon acting as the propellant). 

If such an explanation for the experimental results would be true, it would mean that the thrust was not at all due to the Quantum Vacuum or to Woodward's transient mass effects, and the dreams of a quick trip to the moons of Jupiter and Saturn using this type of propulsion would be thoroughly dashed.  Comprende ?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/21/2014 02:21 pm
Apenas dizendo.

For those having difficulties following the recent discussion ....  Comprende ?

I do follow the gist of the conversation.

What I don't follow are the various specifics.  Which is fine in principle, even as it requires my trust in your all's line of argument. 

The idiot in me sees the genius in you.

[Edit: From the snappy comeback department.   Which is not what namaste means, but close enough.]

But what about GoatGuy's math?  I spent four beers and an hour going over his post yesterday evening, and I choked at the point I mention above.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 02:31 pm

How did he get from Ek = ½ma²t² to Ek = F²t²/(2m)?

Apenas dizendo.

The force equation (from Newton's 2nd Law) is F=ma, where "F" is the force, "m" is the mass and "a" is the acceleration. Hence the acceleration is a=F/m, and all one has to do is to substitute the acceleration expression a=F/m into the Kinetic Energy expression Ek = (½)ma²t² as follows:

Ek = (½)ma²t² = (½)m(F/m)²(t²)= (½)(m/m²)(F²)(t²)=(½)(1/m)(F²)(t²)= F²t²/(2m)

So, no problemo

_________
PS:
A) I have not checked GoatGuy's derivation further than this, but I can make the following trivial comment:


B) It is understood that there is an (inconsequential) assumption in GoatGuy's derivation (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1254645#msg1254645). This assumption does not affect what he addresses (thrust propulsion and energetics).  The assumption is that the velocity is a linear function of time with the constant velocity term = 0,

[GoatGuy]  <<V = at  ... delta V as function of acceleration and time assuming constant)>>


 such that, simply, acceleration=velocity*time.  We might as well state this clearly (even though it is inconsequential) [where I use "v" for velocity instead of GoatGuy's "V" to comply with John's request].

This is easy to show, of course:

x=displacement, v=velocity, a= acceleration

For x=A t² + B t + C, then v=dx/dt= 2 A t + B and a=dv/dt = 2 A, hence

v=a*t + B

(In GoatGuy's derivation the constant velocity term B is zero).

If the velocity would be a higher order function of  time, for example such as an acceleration that varies linearly with time:

For x=D t3 +A t² + B t + C, then v=dx/dt=3 D t² + 2 A t + B and a =dv/dt= 6 D t + 2 A, hence

v=a*t + B - 3 D t²

(GoatGuy derivation is for both the constant velocity term B and the higher order velocity term D to be zero).  His derivation applies to a displacement increasing as the square of time (constant acceleration) without any linear time term (uniform velocity = 0) or higher order (cubic or higher) terms in time.  His derivation is for:

a displacement expressible as follows x=A t² + C  and hence a velocity v= 2 A t and constant acceleration
a = 2 A = v*t
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 02:48 pm
...

John, you wanted to have a sidebar on Woodard's derivation.  If you still want to do this, are there any Woodward-derivation-experts on this thread that could answer questions regarding Woodward's derivation?  Because if there are no people on this thread willing and able to answer Woodward-derivation-questions, it looks like such a thread would be a debate where one of the parties doesn't show up...

Solo dicendo...
Title: Re: EM Drive Developments
Post by: aero on 09/21/2014 04:42 pm
you guyz have lost me
Apenas dizendo.

For those having difficulties following the recent discussion between aero, RotoSequence, Notsosureofit and me, we have been analyzing the possibility (among many possible explanations) that the anomalous thrust experimental results may have been due to (unintended) field emission of electrons from the ("Teflon") PTFE dielectric resonator (acting as an unintended electron rocket with Teflon acting as the propellant). 

If such an explanation for the experimental results would be true, it would mean that the thrust was not at all due to the Quantum Vacuum or to Woodward's transient mass effects, and the dreams of a quick trip to the moons of Jupiter and Saturn using this type of propulsion would be thoroughly dashed.  Comprende ?

Well, not quite. The electron supply could be deliberately designed into the thruster using a hot cathode for example. The question becomes, is the thruster reactionless or not? If the electrons somehow penetrate the base plate and exit the system then the RF resonate cavity thruster becomes nothing but an interesting electron thruster using electrons as the reaction mass. It still has a very good Isp but charge imbalance would quickly eliminate the thrust in space. It would show very good performance when tested in a grounded vacuum chamber. But we can reasonably expect that the electron stream exiting the cavity would be detected in testing.

If instead the electrons somehow do not exit the cavity, it becomes a reactionless thruster which will allow the benefits of the high Isp of the electron beam without the problem of charge build-up on the cavity. This would be a new and to my mind very useful class of thruster.

This leads to my question, "How can the RF waves in the cavity turn the high speed electrons from the axial direction to the sideways direction to impact the side walls without an action in the axial direction?"
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 05:17 pm

Well, not quite. The electron supply could be deliberately designed into the thruster using a hot cathode for example. The question becomes, is the thruster reactionless or not? If the electrons somehow penetrate the base plate and exit the system then the RF resonate cavity thruster becomes nothing but an interesting electron thruster using electrons as the reaction mass. It still has a very good Isp but charge imbalance would quickly eliminate the thrust in space. It would show very good performance when tested in a grounded vacuum chamber. But we can reasonably expect that the electron stream exiting the cavity would be detected in testing.

If instead the electrons somehow do not exit the cavity, it becomes a reactionless thruster which will allow the benefits of the high Isp of the electron beam without the problem of charge build-up on the cavity. This would be a new and to my mind very useful class of thruster.

This leads to my question, "How can the RF waves in the cavity turn the high speed electrons from the axial direction to the sideways direction to impact the side walls without an action in the axial direction?"

Yes, that's better stated, thank you.  The field emission of electrons (from the PTFE dielectric resonator) classical explanation as an electron rocket using the PTFE as the propellant implies that the cavity is leaky enough (at the opposite end of the PTFE dielectric resonator) to allow axial escape of the electrons.   If the experimental measurements were indeed due to any propulsion (a significant assumption in need of verification) I find the idea of real electrons being responsible for it more plausible than virtual electron/positron pairs from the Quantum Vacuum being responsible.

I agree that there are big problems with this explanation, and it appears as another desperate attempt at explaining the experimental results: A) the field emission of electrons when calculations show that the Electric Field is two orders of magnitude lower than the dielectric breakdown, B) the cavity was not tested in a vacuum, since axial trajectory of electrons would need a vacuum, and C) it is unlikely that the opposite end is porous to electrons.

I don't have an answer to your question.  I don't understand why is there a need for "RF waves in the cavity [to] turn the high speed electrons from the axial direction to the sideways direction", since we don't know what is on the interior surface of the circuit board (large diameter) end, and axial exit (perpendicular to the large diameter surface) is needed for axial propulsion.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/21/2014 05:24 pm
This leads to my question, "How can the RF waves in the cavity turn the high speed electrons from the axial direction to the sideways direction to impact the side walls without an action in the axial direction?"

Initially didn't understand what you were aiming at with your electron gun, then your drawing rung my momentum conservation breaking alarm, now this is clearer with this phrase.

Answer : they can't. Action, reaction. If a field turns a particle flow sideways so as to zero its axial momentum, then the axial momentum of the flow has to be imparted to another part of the system. There is no fundamental difference between a long range field mediated momentum exchange and contact forces, consider the thought experiment where the electrons are a water jet, and the field is a solid "conical ramp" (er, quarter circle revolution surface ?) that smoothly throws the jet sideways in a plane perpendicular to the jet. This deviating ramp would be imparted a thrust exactly equal in magnitude and opposite to the thrust of the water jet at its emission. If the ramp and the emitting nozzle are mechanically linked then the system will always have 0 net thrust overall. That is : without rewriting all known physics.

also from a more practical point of view : there can't be smooth electron trajectories like that unless in a good vacuum, the later results (anomalous thrust...) not being in such vacuum.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/21/2014 05:43 pm
Just an update from the pictures:  There is circuit board material on both ends of the truncated cone.  The second layer on the large end seems to be just part of the mount.

Does anyone know where the dielectric material is in the cone ?
Title: Re: EM Drive Developments
Post by: aceshigh on 09/21/2014 05:45 pm
  Comprende ?

not sure if this was spanish or portuguese (like in the last JohnFornaro posts). If it´s portuguese, there are two Es there... "compreende".

but please, follow on. I have not heard portuguese mixed with propellantless propulsion since reading Orson Scott Card's "Speaker to the Dead".  :D :D

at Rodal, regarding both the possibility of the teflon acting as a thruster and the derivation of Woodward's equations, I guess Paul March would be able to answer... I guess those questions would not be under his NDA with NASA.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 05:57 pm
  Comprende ?

not sure if this was spanish or portuguese (like in the last JohnFornaro posts).

It was meant as neither Spanish nor Portuguese.  It was meant as Italian.  Any resemblance to Spanish or Portuguese is a coincidence due to the fact that they are all Romance languages  ;)

But from now on I will use capisce, so that there is no confusion...

Lei capisce ?

http://www.youtube.com/watch?v=l855k2Hh27c
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 06:02 pm
Just an update from the pictures:  There is circuit board material on both ends of the truncated cone.  The second layer on the large end seems to be just part of the mount.

Does anyone know where the dielectric material is in the cone ?

How do you know that there is circuit board material on the small diameter end of the Frustum (truncated cone) ? (the color and smoothness looks very different from the other end)

Take a look at the images below that show the position of the (annular shaped) dielectric resonator:
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/21/2014 06:08 pm
I have this material.  I think the small end looks different because of the lighting, although some of the pieces I have are darker or lighter than others.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/21/2014 06:16 pm
Frustum Dielectric looks like a simulation of a superconducting cavity.  Did the model use a realistic copper wall w/ complex n ??
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 06:23 pm
Frustum Dielectric looks like a simulation of a superconducting cavity.  Did the model use a realistic copper wall w/ complex n ??

There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.

Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 06:43 pm
Frustum Dielectric... model use a realistic copper wall w/ complex n ??
See this COMSOL finite element demonstration paper http://www.michelsencentre.com/doc/pdf%20dokumenter/comsol/comsol_acdc_rf_42a.pdf  for example
Title: Re: EM Drive Developments
Post by: aero on 09/21/2014 07:35 pm
Well, if the RF field can not turn the electron stream without a reacting force, then that leaves

1. Dr. White's idea of the electrons/protons appearing and disappearing from/to the quantum vacuum, and
2. The alternative of the real electrons disappearing into the quantum vacuum.

The first idea has been discounted by critics. The second idea has not been put forward, to my knowledge.

Of course there are the ideas put forth by Shayer, and by the Chinese experimental group, as well as new ideas that might be held Boeing and Cannae groups.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/21/2014 07:37 pm
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.

1. I need to get back outside where we are laying block.   Rather massive objects indeed.  But I came in for a drink of hydrogen dioxide, and noticed this.

2. If the boundary condition is as Rodal suggests, then what difference does it make what you make the truncated conical frusturm thingy out of?

3. I will be printing our Rodal's expostulation on goatGuy's math.  A quick glance is not enough.

4. I guess I'll be starting a Mach to Sciama to Woodward thread.  As some have pointed outo on this thread, there are equational difficulties with Woodward's derivations.

5. Nous n'avons pas encore inclure le français dans le méli-mélo linguistique.

6. Just sayin'.
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/21/2014 07:41 pm
Ok, I am getting confused.  (something which is easily accomplished, but even so)

Quote
<<Moving forward, a new tapered cavity RF resonance system has been designed and characterized using COMSOL® with Q-thruster physics. Figure 26 shows some of the COMSOL® analysis with the higher performance dielectric resonator clearly visible. This resonator material has a relative permittivity that is an order of magnitude higher than our current tapered cavity test article resonator material. The lessons learned with antenna design and location have been factored in and the design of both the drive and sense antennas have been explicitly optimized to excite the RF thruster at the target frequency and mode (e.g., the optimal location has been analytically determined). The thrust performance of this next generation tapered test article has been analytically determined to be in the 0.1 newton per kilowatt regime.>>

Rodal, where did you get this quote from?  Was it in the original paper?

Also:

0.1 newton per kilowatt seems like a big jump in efficiency from the previous design.  Assuming the next round of tests confirms these results,  would thermal heating, pendulum problems, or other obvious errors still be valid alternate explanations?  Especially if said tests were conducted in a full vacuum?

Would the 'electron approach' still be a viable alternate explanation?  Though I am under the impression the electron solution has almost as many problems as the ones involving exotic physics. 

And finally...suppose the next round of tests does confirm a thrust of 0.1 newton's per kilowatt without significant issues from thermal heating, instrument problems, or an abundance of electrons.  Does this mean rewriting part of modern physics?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/21/2014 07:44 pm
Ok, I am getting confused.  (something which is easily accomplished, but even so)
... 

And finally...suppose the next round of tests does confirm a thrust of 0.1 newton's per kilowatt without significant issues from thermal heating, instrument problems, or an abundance of electrons.  Does this mean rewriting part of modern physics?

No doubt but that I am far more accomplished at being confused than you.

Still, let's not sidetrack into rewriting physics.  There is no experimental cause, and the experimentors are silent without cause.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 07:49 pm
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.


2. If the [metal walls are modelled as a] boundary condition is as Rodal suggests, then what difference does it make what you make the truncated conical frusturm thingy out of?

....
6. Just sayin'.

It makes just as much difference as for example when you model the end supports of a beam made with material modulus Ea supported inside another material with modulus Eb at both ends:

1) If the modulus Eb>>Ea one is justified to model the beam with Boundary Conditions such that the rotations at both ends are zero. (A beam clamped at both ends)

2) If the modulus Eb<<Ea one is justified to model the beam with Boundary Conditions such that the rotations at each end are free to rotate at will (a beam with simply supported ends) .

3) If the modulus Eb~Ea then one has to model the Boundary Conditions with springs of a given rotational stiffness (dictated by the stiffness Eb).

Lei capisce ?

It's all in how one models the Boundary Conditions.  Maxwell's equations are differential equations, and to solve them one needs to satisfy Boundary Conditions, just as when one solves a beam equation.

Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 07:52 pm
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.

................

4. I guess I'll be starting a Mach to Sciama to Woodward thread.  As some have pointed outo on this thread, there are equational difficulties with Woodward's derivations.

...............



WHO is going to be explaining/defending Woodward's derivation ?

Just sayin'.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 07:55 pm
Ok, I am getting confused.  (something which is easily accomplished, but even so)

Quote
<<Moving forward, a new tapered cavity RF resonance system has been designed and characterized using COMSOL® with Q-thruster physics. Figure 26 shows some of the COMSOL® analysis with the higher performance dielectric resonator clearly visible. This resonator material has a relative permittivity that is an order of magnitude higher than our current tapered cavity test article resonator material. The lessons learned with antenna design and location have been factored in and the design of both the drive and sense antennas have been explicitly optimized to excite the RF thruster at the target frequency and mode (e.g., the optimal location has been analytically determined). The thrust performance of this next generation tapered test article has been analytically determined to be in the 0.1 newton per kilowatt regime.>>

Rodal, where did you get this quote from?  Was it in the original paper?


That quote is from the last page of the "Anomalous thrust ..." paper
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 08:04 pm
Well, if the RF field can not turn the electron stream without a reacting force, then that leaves

1. Dr. White's idea of the electrons/protons appearing and disappearing from/to the quantum vacuum, and
2. The alternative of the real electrons disappearing into the quantum vacuum.

The first idea has been discounted by critics. The second idea has not been put forward, to my knowledge.

Of course there are the ideas put forth by Shayer, and by the Chinese experimental group, as well as new ideas that might be held Boeing and Cannae groups.

Don't forget (what to me looks like) the (most likely) explanation:

the measured thrust forces are due to spurious testing effects and these tested EM drives will not generate any (translational motion) thrust in space.

Title: Re: EM Drive Developments
Post by: aero on 09/21/2014 09:02 pm
Well, if the RF field can not turn the electron stream without a reacting force, then that leaves

1. Dr. White's idea of the electrons/protons appearing and disappearing from/to the quantum vacuum, and
2. The alternative of the real electrons disappearing into the quantum vacuum.

The first idea has been discounted by critics. The second idea has not been put forward, to my knowledge.

Of course there are the ideas put forth by Shayer, and by the Chinese experimental group, as well as new ideas that might be held Boeing and Cannae groups.

Don't forget (what to me looks like) the (most likely) explanation:

the measured thrust forces are due to spurious testing effects and these tested EM drives will not generate any (translational motion) thrust in space.

If we are going to accept that it is measurement error (Shayer, Chinese, Eagleworks) then we may as well cut this discussion off now and accept that there is nothing to prove.

I wish I knew the time-line for the IV&V testing.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/21/2014 10:06 pm
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.

................

4. I guess I'll be starting a Mach to Sciama to Woodward thread.  As some have pointed outo on this thread, there are equational difficulties with Woodward's derivations.

...............



WHO is going to be explaining/defending Woodward's derivation ?

Just sayin'.

only solution would be to Paul March to return here, or for you to join Woodward's mailing list and keep us updated on your scientific arguments with Woodward himself.
Title: Re: EM Drive Developments
Post by: 93143 on 09/21/2014 10:10 pm
Does this mean rewriting part of modern physics?

Not necessarily.  There could be an explanation that doesn't break anything we thought we knew, without rendering the devices useless for space propulsion.

For instance, it has been suggested that these devices are actually accidental Mach-effect thrusters.  The Mach effect, if valid, does not require throwing away any physics; it was derived from a simplified form of general relativity, and should therefore (if valid) be implicit in the full Einstein field equations combined with known cosmological parameters.

It has been said that Mach's principle is known to be wrong, but this is only true for certain interpretations.  It is admittedly not inherent in general relativity by itself, but according to Sciama it just so happens that in an expanding non-empty Robertson-Walker cosmology (that is, the kind we live in), the equations of general relativity just happen to result in something that behaves exactly like inertia.  According to later calculations, this requires the universe's density parameter to be of order unity (the exact number varies depending on how Einstein's equations are approximated), and recent observations of the universe have pegged this parameter at almost exactly one.  Note that there is still no widely-accepted theory of what inertia is...

...

I've been trying to integrate the hypothetical Wheeler-Feynman-type interaction out to the cosmological horizon (not the Hubble radius; that seems to be a misconception) to test my Doppler effect idea, but either I have a mental block or it's harder than I thought (I am not trained in general relativity and was trying to shortcut around the complicated bits)...  also I have a lot of thermodynamic calculus I need to be doing for work, so I can only pay so much attention to this...
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/21/2014 10:12 pm
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.

... 4. I guess I'll be starting a Mach to Sciama to Woodward thread.  As some have pointed outo on this thread, there are equational difficulties with Woodward's derivations.

WHO is going to be explaining/defending Woodward's derivation ?  Just sayin'.

iS IT NOW BEING SUGGESTED THAT wOODWARD'S MATH CANNOT STAND ON ITS OWN?

Hey.  Who locked the caps key?
Title: Re: EM Drive Developments
Post by: frobnicat on 09/21/2014 10:24 pm
Compressed hummingbird wings? (Which is real)  Ground unicorn horns? (Which is fake)

Now we are getting at it, I was sure this new tech development would be an ecological disaster of some sort, how many hummingbird to thrust 80 metric tons to Saturn ? As for the (allegedly fake...) later proposition, you think unicorns aren't rare enough to take a toll on their population diversity ?

Quote
The second case is a bit harder to prove, but still within reach of ordinary algebra:

Ek = ½mV²   ... kinetic energy as a function of V, again.
V = at ... again, now substitute
Ek = ½ma²t²  and remembering that [F = ma]...
Ek = F²t²/(2m)

If F = ma, then F^2 = (ma)^2 = m^2a^2, correct?

GoatGuy doesn't write that.  Instead he writes:

Quote from: goatGuy
Ek = ½ma²t²

How did he get from Ek = ½ma²t² to Ek = F²t²/(2m)?

Apenas dizendo.

Je peux donner un coup de main sur ce petit exercice d'algèbre :

F = ma, then F² = (ma)² = m²a², (1) is correct
We want (well, GoatGuy wants) to get rid of a from  Ek = ½mt² (2)
So from (1) dividing left and right by m² we can rewrite that F²/m²=m²a²/m²=a²
That is a²=F²/m² (really we could simply have squared a=F/m to get this one)
Substitution of a² by F²/m² in (2) yields :
Ek = ½ m F²/m² t² =  (m F² t²) / (2 m²) = (F²t²)/(2m)  (divide numerator and denominator by m)

CQFD : Ce qu'il fallait démontrer.

Quote
Nous n'avons pas encore inclure inclus le français dans le méli-mélo linguistique.
Was almost perfect French, just "inclure" is present infinitive while here we need "participe passé" : "avoir inclus". Had to look into conjugations tables (http://www.larousse.fr/conjugaison/francais/inclure/5448) to be sure of the ending s though !
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/21/2014 10:25 pm
Where does one find Woodward's math ?  It would be interesting to see how it compares to a General Relativity interpretation.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 10:42 pm
Where does one find Woodward's math ?  It would be interesting to see how it compares to a General Relativity interpretation.
Excellent question.  From what I found so far:

1) Woodward's derivation uses a flat Minkowski space.  In that sense he does not use Einstein's General Relativity.  He uses Special Relativity (and says so in a number of places). There is no curvature of space in Woodward's derivation.  There is no covariant, contravariant or mixed tensors. No Riemannian geometry.
Gravity is given "ab initio" (unlike Einstein's General Relativity where gravity is a result of curving of space by massive objects), yet goes on to postulate transient mass effects due in most part to most distant objects.  The justification appears to be isotropy of spacetime and local flatness of spacetime.

2) He uses the [rest energy/volume] relationship to [rest density] Eo=rho c^2 sometimes here and sometimes there.

3) I have not found Woodward's transient mass effect equations in any paper by Sciama.  He apparently uses some results from Sciama's 1953 paper and goes on from there.  From what I can gather Woodward does not use Sciama's 1969 (paper) perturbation of General Relativity.


Many questions...  Perhaps somebody would be willing to explain/correct the above statements
and give a link where Woodward's most complete derivation is contained
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/21/2014 10:50 pm
Yes, but are his papers publicly available and if so where ?

Sorry, didn't mean to sound picky.

OK. So there's a good chance I still have the '64 Sciama here somewhere, at least.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 11:20 pm
Yes, but are his papers publicly available and if so where ?

Sorry, didn't mean to sound picky.
Of the papers that I found in the web, this link (see the Appendix A) has the most complete derivation: http://wqww.theeestory.com/files/Flux_Caps___Origin_of_inertia_04-20-2004.pdf

Yet, not enough for me.  Hope somebody can point to a more complete reference

[Sorry I had the caps key on for a while. It was an accident  :(]
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 11:30 pm
[
Je peux donner un coup de main sur ce petit exercice d'algèbre :

F = ma, then F² = (ma)² = m²a², (1) is correct
We want (well, GoatGuy wants) to get rid of a from  Ek = ½mt² (2)
So from (1) dividing left and right by m² we can rewrite that F²/m²=m²a²/m²=a²
That is a²=F²/m² (really we could simply have squared a=F/m to get this one)
Substitution of a² by F²/m² in (2) yields :
Ek = ½ m F²/m² t² =  (m F² t²) / (2 m²) = (F²t²)/(2m)  (divide numerator and denominator by m)

CQFD : Ce qu'il fallait démontrer.



Ah, je vois !   http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260041#msg1260041



Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/21/2014 11:32 pm
"oin Woodward's mailing list"

Tried that.  Didn't work.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/21/2014 11:33 pm
Yes, but are his papers publicly available and if so where ?

Sorry, didn't mean to sound picky.

OK. So there's a good chance I still have the '64 Sciama here somewhere, at least.

That would be a paper that I haven't mentioned, nor know of.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/21/2014 11:36 pm
Interesting, note the 50KHz vs couple Gig.  Capacitive effect of dielectric surface to microwaves, check.

Virtual proton/positron creation is a strong function of photon energy (Hz).
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/21/2014 11:38 pm
Maintenant, on arrive à elle, j'étais sûr que ce nouveau développement de la technologie serait une catastrophe écologique d'une certaine sorte, combien de colibri de poussée de 80 tonnes à Saturne? Quant à la (soi-disant faux ...) proposition plus tard, vous pensez que les licornes ne sont pas suffisamment rare pour prendre un péage sur la diversité de leur population?

I am so NOT running this thru the translator.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/21/2014 11:43 pm
Lei capisce ?

http://www.youtube.com/watch?v=l855k2Hh27c

Sounds a mite gangsta.
Title: Re: EM Drive Developments
Post by: Rodal on 09/21/2014 11:51 pm

Sounds a mite gangsta.

Mi scusi  :(
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 12:07 am
Yes, but are his papers publicly available and if so where ?

Sorry, didn't mean to sound picky.

OK. So there's a good chance I still have the '64 Sciama here somewhere, at least.

Here is Sciama's 1953 vintage (John's favorite year)  http://mnras.oxfordjournals.org/content/113/1/34.full.pdf
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 12:17 am
Interesting, note the 50KHz vs couple Gig.  Capacitive effect of dielectric surface to microwaves, check.

Virtual proton/positron creation is a strong function of photon energy (Hz).

The following does not check :

Virtual Pair production can only occur if the photons have an energy exceeding twice the rest energy of an electron (0.511 MeV rest energy, which doubled is --->1.022 MeV).

In 2008 the Titan laser aimed at a 1-millimeter-thick gold target was used to generate positron–electron pairs in large numbers. (No Titan laser near the NASA experiments)

[The Titan is a combined nanosecond-long pulse and ultrashort-pulse (subpicosecond) laser, with hundreds of joules of energy in each beam. This petawatt-class laser is used for a range of high-energy density physics experiments, including the science of fast ignition for inertial confinement fusion energy]
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 12:55 am
For 2 GHz I calculate the photon energy to be only 8x10^(-6) eV, good enough to heat food and drinks by exciting molecular rotations and vibrations, but not anywhere near good enough to produce electron/positron virtual particles.  Even X-Rays have photon energy of only 10^4 eV, so it looks like one needs wavelengths even smaller than 1 nanometer (need ~ picometer) to be able to produce virtual particles (we need 10^6 eV).

See:  http://en.wikipedia.org/wiki/Electronvolt#mediaviewer/File:Light_spectrum.svg

(Please check my math ...)

E= h c/λ =( ( 6.63x10^(-34) ) J s *( 3*10^8 m/s ) /(1.6x10^(-19) J/ eV)  ) /λ

where λ is the wavelength in meters
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/22/2014 02:25 am
"Pair production" can only occur if the photons have an energy exceeding twice the rest energy of an electron (0.511 MeV rest energy, which doubled is --->1.022 MeV).

Virtual pairs are never produced.  The question is can they carry momentum ?




Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 02:31 am
So, it is even much more unlikely (by a factor of 10^(-11) compared to 10^(-2)) for the microwave to produce virtual particle electron/positron pairs than for the PTFE  dielectric resonator to produce real electrons by field emission.  And no, if electrons are indeed released by the PTFE dielectric, they are not going to disappear into the quantum vacuum because to do that they would need to get annihilated by real positrons (it is practically impossible for any real positron to show up in the microwave cavity -much more improbable than for a virtual electron-positron pair to show up).
Title: Re: EM Drive Developments
Post by: 93143 on 09/22/2014 02:42 am
The Mach effect... was derived from a simplified form of general relativity

1) Woodward's derivation uses a flat Minkowski space.  In that sense he does not use Einstein's General Relativity.  He uses Special Relativity (and says so in a number of places). There is no curvature of space in Woodward's derivation.  There is no covariant, contravariant or mixed tensors. No Riemannian geometry.
Gravity is given "ab initio" (unlike Einstein's General Relativity where gravity is a result of curving of space by massive objects), yet goes on to postulate transient mass effects due in most part to most distant objects.  The justification appears to be isotropy of spacetime and local flatness of spacetime.

2) He uses the [rest energy/volume] relationship to [rest density] Eo=rho c^2 sometimes here and sometimes there.

3) I have not found Woodward's transient mass effect equations in any paper by Sciama.  He apparently uses some results from Sciama's 1953 paper and goes on from there.

Okay, I simplified a bit.

It is true, and should be understood, that Sciama-type Machian inertia (which is derived from a vector theory of gravity that turned out to be a simplified form of GR) is separate from Woodward's "Mach effect" theory (which was derived from Sciama's theory).

But the main point I was trying to get across is that as far as I know neither of these theories requires us to abandon any accepted physics, since (a) they are derived within the framework of accepted physics, and (b) the phenomenon they explain currently has no commonly-accepted physical explanation.
Title: Re: EM Drive Developments
Post by: aero on 09/22/2014 04:28 am
"Pair production" can only occur if the photons have an energy exceeding twice the rest energy of an electron (0.511 MeV rest energy, which doubled is --->1.022 MeV).
As I understand, that is correct but I also understand that this pair is a real electron and a real antielectron (positron). And when they self annihilate they produce real energy. Not what we are seeing.
Quote
Virtual pairs are never produced.  The question is can they carry momentum ?
Not produced in any way that we know of. They appear from the quantum vacuum and disappear into it. I believe they do so leaving no trace of their passing. The fly in that ointment is that the electron is real as I understand it while the positron is not but to reach that conclusion I go back to the 1930's as the theory was developed. Point is, virtual electron/positron pairs do not leave an energy trace when they annihilate. Hence virtual, but the electron is real else why bother developing the theory in the first place?
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 11:43 am
"Pair production" can only occur if the photons have an energy exceeding twice the rest energy of an electron (0.511 MeV rest energy, which doubled is --->1.022 MeV).
As I understand, that is correct but I also understand that this pair is a real electron and a real antielectron (positron). And when they self annihilate they produce real energy. Not what we are seeing.
Quote
Virtual pairs are never produced.  The question is can they carry momentum ?
Not produced in any way that we know of. They appear from the quantum vacuum and disappear into it. I believe they do so leaving no trace of their passing. The fly in that ointment is that the electron is real as I understand it while the positron is not but to reach that conclusion I go back to the 1930's as the theory was developed. Point is, virtual electron/positron pairs do not leave an energy trace when they annihilate. Hence virtual, but the electron is real else why bother developing the theory in the first place?
See http://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/

<<Virtual particles, [this means the virtual electron as well as the virtual positron] which are what appear in the loop in that diagram, are not particles.  They are not nice ripples, but more general disturbances.  And only particles have the expected relation between their energy, momentum and mass; the more general disturbances do not satisfy these relations.  So your intuition is simply misled by misreading the diagram.  Instead, one has to do a real computation of the effect of these disturbances.  In the case of the photon, it turns out the effect of this process on the photon mass is exactly zero.>>
Title: Re: EM Drive Developments
Post by: frobnicat on 09/22/2014 12:17 pm
Yes this article by Matt Strassler is very good at explaining things, and the loooong comments section is worthwhile too as he answers with great patience and pedagogy a lot of more or less obvious questions asked by people not trained to QFT when confronted to those concepts.
Virtual particles can't propagate, that is precisely what makes them virtual. Only field disturbances that reach a certain level of "punch" (the level of quanta) can propagate on their own away from their source on an independent trajectory, contrary to virtual disturbances that always are "linked" to a real source. If I understand well what's explained.

Aero, I have the feeling you want to treat positrons differently from electrons. A (real, not "virtual") positron is as real as an electron, as real as a particle can get, to the point of giving dermatitis (or worse) if you really want to hold that reality in your hand (Beta+ decay radioactive source for instance). The fact that the anti-electron is "moving backward in time" is just a mathematical way of stating that the equations are identical (almost ? perfectly ?) upon time-charge-parity inversion as explained in this thread (http://physics.stackexchange.com/questions/86988/anti-matter-as-matter-going-backwards-in-time-requesting-further-clarification) :
Quote
Identifying a positron as a backwards in time electron, is an elegant interpretation that exhibits in the Feynman diagrams the CPT symmetry they must obey.

What I am saying is : the statement: "positrons are backward going electrons" is a convenient and accurate mathematical representation for calculation purposes. "As if". There has not been an indication, not even a tiny one, that in nature as we study it experimentally anything goes backwards in time, as we define time in the laboratory .

So positrons are not causing havoc in causality or usual arrow of time, they have no reason to be less real than electrons, they are symmetrical solutions to the same field as the electron field (if I understand correctly). Sorry if I misunderstood what I thought you were implying.
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 01:10 pm
Lawrence Livermore National Laboratory in California has used a short, ultra-intense laser to irradiate a millimetre-thick gold target and produce more than 100 billion (very real ) positrons:  http://www.nbcnews.com/id/27998860/#.VCAfKvk7s0s

But again, it takes a very powerful (petawatt-class)  ultrashort-pulse (subpicosecond) laser to produce real positrons. 

Real positrons (or electrons) will not pop out of the quantum vacuum on their own in a microwave cavity like Cannae's or the Frustum tested at NASA.

One needs wavelengths  ~ picometer (frequencies 10^(11) times higher than microwave frequencies) to be able to produce real positrons or real electrons from photons (we need 10^6 eV).

As JohnFornaro said, very appropriately, alchemists in the Middle Ages thought that they could turn lead into gold by conventional chemistry.  They couldn't.  It turns out that one needs orders of magnitude higher energy (a particle accelerator) to turn lead into gold.  Similarly, it takes much higher energy (and frequency) to produce positrons (or electrons) from photons, a microwave won't do it.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/22/2014 01:49 pm
...JohnFornato...

You say Fornato.  I say Fornaro.

But hey.
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 01:58 pm
...JohnFornato...

You say Fornato.  I say Fornaro.

But hey.
The "t" is next to the "r" in the keyboard and it was early in the morning...But hey, it's much easier to fix this than to turn lead into gold.   It's fixed now  :)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/22/2014 02:01 pm
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.


2. If the [metal walls are modelled as a] boundary condition as Rodal suggests, then what difference does it make what you make the truncated conical frusturm thingy out of?

....
6. The usual rejoinder.

It makes just as much difference as for example when you model the end supports of a beam made with material modulus Ea supported inside another material with modulus Eb at both ends:

blah, blah, blah...

Lei capisce ?

It's all in how one models the Boundary Conditions.  Maxwell's equations are differential equations, and to solve them one needs to satisfy Boundary Conditions, just as when one solves a beam equation.

That's what I'm getting at, my gangsta godfadda.  What I took the above conversation to mean was that the results (all those Roy G. Biv color schemes) cannot be well understood without knowing the boundary conditions.  Since there was "no distinction" between the cavity interor and the metal wall, you assume (which is what your "reading" of that is) that there must be a boundary condition defined somewhere.  That boundary condition is not specified, and would differ significantly on whether the boundary's various modulii were based on copper or compressed hummingbird wings.

Ergo, (ipso fatso being my preferred translation, BTW) there are limited conclusions which can be drawn from the FEA display of the electric field.

Non?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/22/2014 02:02 pm
It's fixed now

What???  You changed the Akashic record?
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 02:17 pm
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.


2. If the [metal walls are modelled as a] boundary condition as Rodal suggests, then what difference does it make what you make the truncated conical frusturm thingy out of?

....
6. The usual rejoinder.

It makes just as much difference as for example when you model the end supports of a beam made with material modulus Ea supported inside another material with modulus Eb at both ends:

blah, blah, blah...

Lei capisce ?

It's all in how one models the Boundary Conditions.  Maxwell's equations are differential equations, and to solve them one needs to satisfy Boundary Conditions, just as when one solves a beam equation.

That's what I'm getting at, my gangsta godfadda.  What I took the above conversation to mean was that the results (all those Roy G. Biv color schemes) cannot be well understood without knowing the boundary conditions.  Since there was "no distinction" between the cavity interor and the metal wall, you assume (which is what your "reading" of that is) that there must be a boundary condition defined somewhere.  That boundary condition is not specified, and would differ significantly on whether the boundary's various modulii were based on copper or compressed hummingbird wings.

Ergo, (ipso fatso being my preferred translation, BTW) there are limited conclusions which can be drawn from the FEA display of the electric field.

Non?

Well, yeah, kernosabe, there is a certain amount of hypothetical trust (for review purposes) involved in any discussion of reported results.

Having said that, you asked me to go ahead with calculations on the inverted pendulum parasitic modes, where I have even less information (I would need to know the dimensions of the devices and the supports, to calculate the moments of inertia).  What d'ya think?
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 02:21 pm
It's fixed now

What???  You changed the Akashic record?

<<In theosophy and anthroposophy, the akashic records (from akasha, the Sanskrit word for 'sky' 'space' or 'æther') are a compendium of mystical knowledge supposedly encoded in a non-physical plane of existence known as the astral plane. There is no scientific evidence for the Akashic records.>>

Never heard of Akashic  records before.  Great! You taught me something new today, kernosabe    :)
Title: Re: EM Drive Developments
Post by: aceshigh on 09/22/2014 02:48 pm
hey Dr Rodal, regarding the derivation of Woodward's Mach Effect, I asked GiThruster at TalkPolywell

Quote from: GiThruster
I would just recommend the book. If Dr. Rodal wants to be placed on Woodward's general reading list where he can have a dialog on this issue, have him send me a note to this effect with a couple sentences of his background and interest and I'll forward this to Jim.
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 03:01 pm
hey Dr Rodal, regarding the derivation of Woodward's Mach Effect, I asked GiThruster at TalkPolywell

Quote from: GiThruster
I would just recommend the book. If Dr. Rodal wants to be placed on Woodward's general reading list where he can have a dialog on this issue, have him send me a note to this effect with a couple sentences of his background and interest and I'll forward this to Jim.
I take from this that GiThruster (whoever he is) thinks that such a discussion (Woodward's derivation) can only take place there and not here at NASAspaceflight.  Concerning the derivation of transient mass terms, I would rather use the peer-reviewed papers by Dr. Woodward than a book "Making Starships and Stargates and Absurdly Benign Wormholes"

I'll leave the construction of Stargates and Absurdly Benign Wormholes to John: he was moving some large masses yesterday  :)

Guarda, sto solo dicendo

Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/22/2014 04:02 pm
<<Virtual particles, [this means the virtual electron as well as the virtual positron] which are what appear in the loop in that diagram, are not particles.  They are not nice ripples, but more general disturbances.  And only particles have the expected relation between their energy, momentum and mass; the more general disturbances do not satisfy these relations.  So your intuition is simply misled by misreading the diagram.  Instead, one has to do a real computation of the effect of these disturbances.  In the case of the photon, it turns out the effect of this process on the photon mass is exactly zero.>>

Yes, this is certainly correct.  There is not even a mathematical reason to think otherwise. (that I know of anyway)

Always assuming that the experimental results are real:

The only hope I see from QED (so far anyway) is with the 2-photon interaction mediated w/ the dielectic dipoles, and not the symmetrical case. The dispersion in the microwave cavity would have to be connected to a nonlinear term that could generate a massive real escaping particle. (dark matter ??)

What bothers my gut is the symmetry of the GR situation in an AFR.  The presence of the dielectric (and it's charge pairs) might be the antacid for that.  I don't remember anyone trying to add another (nonlinear) differential equation to the EM cavity solutions to get transport properties. ( ~ bulk viscosity as in acoustics etc)

OK, enough grousing, off to dig around in the paper pile .
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 04:40 pm
<<Virtual particles, [this means the virtual electron as well as the virtual positron] which are what appear in the loop in that diagram, are not particles.  They are not nice ripples, but more general disturbances.  And only particles have the expected relation between their energy, momentum and mass; the more general disturbances do not satisfy these relations.  So your intuition is simply misled by misreading the diagram.  Instead, one has to do a real computation of the effect of these disturbances.  In the case of the photon, it turns out the effect of this process on the photon mass is exactly zero.>>

Yes, this is certainly correct.  There is not even a mathematical reason to think otherwise. (that I know of anyway)

Always assuming that the experimental results are real:

The only hope I see from QED (so far anyway) is with the 2-photon interaction mediated w/ the dielectic dipoles, and not the symmetrical case. The dispersion in the microwave cavity would have to be connected to a nonlinear term that could generate a massive real escaping particle. (dark matter ??)

What bothers my gut is the symmetry of the GR situation in an AFR.  The presence of the dielectric (and it's charge pairs) might be the antacid for that.  I don't remember anyone trying to add another (nonlinear) differential equation to the EM cavity solutions to get transport properties. ( ~ bulk viscosity as in acoustics etc)

OK, enough grousing, off to dig around in the paper pile .

We agree.  Concerning adding nonlinearities to the differential equations, yes people have been trying to do that since at least Schrodinger's time, but so far (from my limited knowledge) A) all quantum mechanics experiments have confirmed the linear equations of quantum mechanics and B) several nonlinear theories lead to unphysical results. 

We agree again concerning the dielectric material because the material introduces a constitutive equation and we know that

A) constitutive equations can certainly be nonlinear (for real materials) and
B) constitutive relations can only be ascertained from experiments and never from theoretical principles

However, what bothers me is that analyzing this shows that (unless they had a very defective PTFE ("Teflon") dielectric and/or much higher transient Electric Field) the dielectric had an imposed Electric Field hundreds of times less than the amount necessary for breakdown of a good sample of PTFE ("Teflon") .  They would have had to either have a very defective PTFE  ("Teflon")  and/or a much higher electric field applied (at least transiently) than the one reported. 

Perhaps their computations don't adequately reflect transient Electric Field terms ?

And even if the dielectric material experienced some sort of breakdown and particles were emitted (either electrons or something more exotic) one still would need these emitted particles to escape the other end of the drive to have propulsion.

And, even if the dielectric material experienced some sort of breakdown and particles were emitted (either electrons or something more exotic) this would not be a propellant-less drive but instead the PTFE  ("Teflon") would have been the propellant, so it would be a big dissapointment for anybody that booked her quick trip to Enceladus based on the reported figures at the end of the report.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/22/2014 05:06 pm
I'll leave the construction ... to John: he was moving some large masses yesterday.

Hey.  I resemble that!
Title: Re: EM Drive Developments
Post by: aceshigh on 09/22/2014 05:10 pm
I take from this that GiThruster (whoever he is) thinks that such a discussion (Woodward's derivation) can only take place there and not here at NASAspaceflight.

No, I take that GiThruster thinks Dr Woodward doesn´t really frequents discussion boards, and that GiThruster himself either isn´t capable of doing the derivations that you need or more simply, that he can´t participate in such discussions here, because he was banned long ago from NasaSpaceFlight Forums.

It isn´t so much a question of he thinking if the derivation discussion should take place here. It's a question of that it CAN´T take place here, unless Paul March returns to this topic.


I guess you noticed noone else here at Nasa Spaceflight Forums was qualified for the depth of discussion of the derivation of Dr Woodward equations, which was the reason you even said it would be a bit unfair to discuss here as it would be a one sided argument.
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 05:21 pm
hey Dr Rodal, regarding the derivation of Woodward's Mach Effect, I asked GiThruster at TalkPolywell

Quote from: GiThruster
I would just recommend the book. If Dr. Rodal wants to be placed on Woodward's general reading list where he can have a dialog on this issue, have him send me a note to this effect with a couple sentences of his background and interest and I'll forward this to Jim.
I take from this that GiThruster (whoever he is) thinks that such a discussion (Woodward's derivation) can only take place there and not here at NASAspaceflight.  Concerning the derivation of transient mass terms, I would rather use the peer-reviewed papers by Dr. Woodward than a book "Making Starships and Stargates and Absurdly Benign Wormholes"

I'll leave the construction of Stargates and Absurdly Benign Wormholes to John: he was moving some large masses yesterday  :)

Guarda, sto solo dicendo

Woodward's stated assumption is (in Woodward's own words)

<< the assumption that all of the power delivered to the capacitors ends up as a proper energy density fluctuation is an optimistic, indeed, perhaps wildly optimistic, assumption>> (Italics added for emphasis)
(p.5 of FLUX CAPACITORS AND THE ORIGIN OF INERTIA http://wqww.theeestory.com/files/Flux_Caps___Origin_of_inertia_04-20-2004.pdf)

Why should the power fluctuation delivered to the capacitors end up as any significant rest energy density fluctuation ?

Woodward fully admits that he just hopes it will.


I say no, that the power fluctuation delivered to the capacitor ends up elsewhere and there is completely insignificant change to the rest energy density.   To access the rest energy E=mc^2 one needs a humongous amount of power (like a nuclear reaction, etc.) (http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence )

This is a little similar to my car (which is not a FLT DeLorean), when I go on the highway the car's power ends up as kinetic energy, wasted heat energy (including friction and dissipation in the rubber tires, etc.).  When I go up a hill you can add some potential energy (and decrease it when I go downhill). But none of the power goes to change the rest energy of my car.  Adherents to this theory will complain that but, but, but it is different for electromagnetic energy in a capacitor or in a dielectric. To which I say, not much difference.  The capacitors and dielectrics involved do not have ongoing nuclear reactions, etc.  The capacitors and dielectrics involved are undergoing very mundane circumstances (just as when you cook some food in your microwave on a teflon-coated dish). If you don't agree, you can resort to experiments to resolve our disagreement...

And to those that claim that Woodward's theory does not involve a big leap of faith, I say: yes it does.  Woodward himself wrote so:

<< the assumption that all of the power delivered to the capacitors ends up as a proper energy density fluctuation is an optimistic, indeed, perhaps wildly optimistic, assumption>>

The problem with Woodward's transient terms is not in Sciama's view of inertia (Mach's effect).  The problem is Woodwrd's assumption that any power fluctuation (not by non-nuclear, etc., means) delivered to capacitors or dielectrics by mundane means can result in a fluctuation in rest energy.
 
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/22/2014 05:53 pm
I agree that Dr. Woodward's theory needs a leap of faith *and* to be wildly optimistic about it's utility.
Nevertheless, we have anomalous thrust reported and it needs to be thrashed out and disproved.
The good Dr. Rodal is doing a fine effort here to resolve the questions we have.
Thank you Dr. Rodal for putting the question on an even keel. I know you expect experimental error, but until it is quantified you have an open mind.
Refreshing!
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 06:03 pm
 :)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/22/2014 06:23 pm
I do still have Sciama '64 and Erratta.  It'll take a while to remember how to read it ! ;D

The only comment I can remember was "Remember, these Maxwellian equations are just tautological relations between a particle representation and a field representation."

Edit:  I just noticed this was from the "Third International Conference on the Mossbauer Effect"
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/22/2014 06:25 pm
I do still have Sciama '64 and Erratta.  It'll take a while to remember how to read it ! ;D

The only comment I can remember was "Remember, these Maxwellian equations are just tautological relations between a particle representation and a field representation."
Isn't that QM in a nutshell?
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 06:37 pm
I do still have Sciama '64 and Erratta.  It'll take a while to remember how to read it ! ;D

The only comment I can remember was "Remember, these Maxwellian equations are just tautological relations between a particle representation and a field representation."

I have not seen any paper by Sciama on Mach's principle from 1964.  The papers I have seen from him on this topic are his flat spacetime 1953 paper http://exvacuo.free.fr/div/Sciences/Dossiers/Gravite-Inertie-Mass/Inertie/Sciama/D%20W%20Sciama%20-%20On%20the%20origin%20of%20inertia.pdf that Woodward used as a reference and his 1969 paper on a perturbation of General Relativity regarding the same.  None of these papers dealt with Maxwell's equations.

If you have another Sciama paper dealing with Mach's inertia for Maxwell's equations I would be most interested in it.  Particularly since you also have an Errata for the paper.  Is that an official Errata sheet from the author or is it the Errata you found on the paper?  I have not seen an author's Errata sheet either for the 1953 or 1969 papers either.

Could you please provide the title of the 1964 paper and the journal information for such paper?

Thanks
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/22/2014 06:44 pm
Reviews of Modern Physics vol 36 pp463 and 1103

"The Physical Structure of General Relativity"
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 06:45 pm
Reviews of Modern Physics vol 36 pp463 and 1103

Thanks.  I don't have that paper.  Does Sciama specifically discuss his Mach's principle in that particular paper too?
Title: Re: EM Drive Developments
Post by: aero on 09/22/2014 06:49 pm

From Wikipedia http://en.wikipedia.org/wiki/Zero-point_energy (http://en.wikipedia.org/wiki/Zero-point_energy)

Quote
As a scientific concept, the existence of zero-point energy is not controversial, although the ability to harness it is.[11] Over the years, there have been numerous claims of devices capable of extracting usable zero-point energy. None of the claims have ever been confirmed by the scientific community at large, and most of these claims are dismissed either by default, after third-party inspection of such a device or based on disbelief in the viability of a technical design and theoretical corroboration. Current claims to zero-point-energy-based power generation systems are considered pseudoscience by the scientific community at large [12][13] and skeptics usually dismiss efforts to harness zero-point energy by default.
Quote
Despite the scientific stance to typically discount the claims, numerous articles and books have been published addressing and discussing the potential of tapping zero-point-energy from the quantum vacuum or elsewhere. Examples of such are the work of the following authors: Claus Wilhelm Turtur,[15] Jeane Manning, Joel Garbon,[16] John Bedini,[17] Tom Bearden,[18][19][20] Thomas Valone,[21][22][23] Moray B King,[24][25][26] Christopher Toussaint, Bill Jenkins,[27] Nick Cook[28] and William James.[29]
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/22/2014 06:55 pm
The bulk of the paper is on Mach's Principle.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/22/2014 07:04 pm
At the end of section 2.2 "It will also be interesting to see whether in the quantized theory the inertial waves have zero rest mass"  ref: P. W. Anderson, Phys. Rev. 130, 439 (1963)
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 07:16 pm
At the end of section 2.2 "It will also be interesting to see whether in the quantized theory the inertial waves have zero rest mass"  ref: P. W. Anderson, Phys. Rev. 130, 439 (1963)

Thanks, @Notsosureofit, but (refer to my prior post http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260728#msg1260728) the crux of Woodward's effect is not at all with Sciama's hypothesis.  Nowhere in his '53 or '69 papers (please check whether this is the case for the '64 paper too) Sciama claims that mundane fluctuations in capacitor's or dielectric's power can result in significant fluctuations in the rest mass. 

On the contrary, Sciama writes the opposite:

<<Since the change of rho [the density] with time is very small, the gravelectric part of the field is approximately>> p. 38 of ON THE ORIGIN OF INERTIA © Royal Astronomical Society  http://adsabs.harvard.edu/full/1953MNRAS.113...34S

The assumption that mundane fluctuations in capacitor's or dielectric's power can result in significant fluctuations in the rest mass rests squarely on the shoulders of Dr. Woodward assuming that he can substitute the Rest Energy by the electric power input energy -something that Sciama never does-.  I think that this (wildly optimistic -in Dr. Woodward's own words) assumption by Dr. Woodward is unjustified.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/22/2014 07:42 pm
Just finished scanning through, he quite specifically excludes electromagnetism, just uses analogies.

"We may note in passing that the result (7) suggests that unified field theories based on a nonsymmetric connection have nothing to do with electromagnetism"

So I didn't see any connection.  (brought up memories though)
Title: Re: EM Drive Developments
Post by: aceshigh on 09/22/2014 07:50 pm
well, since people who have access to Dr Woodward's discussion list do not participate in this forum (except for Paul March, but he seldom posts), since Dr Woodward is not a discussion forum user as far as I know, and since Dr Rodal doesn´t seem interested in joining Dr Woodward's emailing list, I guess discussing the derivation of Woodward's equations here is a bit useless?
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 07:59 pm
well, since people who have access to Dr Woodward's discussion list do not participate in this forum (except for Paul March, but he seldom posts), since Dr Woodward is not a discussion forum user as far as I know, and since Dr Rodal doesn´t seem interested in joining Dr Woodward's emailing list, I guess discussing the derivation of Woodward's equations here is a bit useless?
It may be "a bit useless" from your point of view, but it may be bit useful to others to note that:

Dr. Woodward himself states "his leap of faith" (equating fluctuations in the Rest Energy with fluctuations in  the Input Electric Energy to a capacitor), which to me is unjustified and Dr. Woodward himself states is "wildly optimistic" and is an "arguable" assumption.

So, yes to me, this was a useful discussion to have.  It means from my point of view (until somebody can justify equating fluctuations in the Rest Energy with fluctuations in the Input Electric Energy) that Woodard's effect is not a valid justification for propellant-less propulsion.

It has nothing to do with arguing about Mach's principle or with Sciama's (which to me distract from the key Woodward assumption that he equates fluctuations in Rest Energy with fluctuations in Input Electric Energy to a capacitor).

And it is useful to me that @Notsosureofit pointed out the '64 paper by Sciama and its Errata (which I didn't have). It is useful to the community that @Notsosureofit  points out that Sciama's '64 paper further deals with the Machian principle but contains no such assumption (equating the fluctuations in Rest Energy with the fluctuations in Input Electric power).

So yes, this discussion was useful to me: I learned from @Notsosureofit about Sciama's '64 paper.

A lot of what I discussed may not be useful to others.  But I have room to improve in the future... :)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/22/2014 08:34 pm
Still poking around, found this interesting exercise (using neutrinos) in particle based gravity.  I have the 1999 but I notice that its on arXiv as 2008

http://arxiv.org/pdf/astro-ph/0102109.pdf
Title: Re: EM Drive Developments
Post by: aceshigh on 09/22/2014 08:48 pm
A lot of what I discussed may not be useful to others.  But I have room to improve in the future... :)

my point when I said it was not useful was based on what apparently was a wrong interpretation of you said

Quote from: Rodal
Because if there are no people on this thread willing and able to answer Woodward-derivation-questions, it looks like such a thread would be a debate where one of the parties doesn't show up...

if you are saying it is useful despite that quote, I gather the problem lies in my previous interpretation of what you said. No problems then.
Title: Re: EM Drive Developments
Post by: Rodal on 09/22/2014 09:27 pm
A lot of what I discussed may not be useful to others.  But I have room to improve in the future... :)

my point when I said it was not useful was based on what apparently was a wrong interpretation of you said

Quote from: Rodal
Because if there are no people on this thread willing and able to answer Woodward-derivation-questions, it looks like such a thread would be a debate where one of the parties doesn't show up...

if you are saying it is useful despite that quote, I gather the problem lies in my previous interpretation of what you said. No problems then.

@aceshigh

You are correct. What happened is that when I wrote << it looks like such a thread would be a debate where one of the parties doesn't show up>> I had not yet realized that Woodward himself had acknowledged making that key assumption, equating fluctuations in Rest Energy with fluctuations in Input Electric Power to a capacitor without much justification.  I just realized this very recently.

Mas não faz mal   :)
Title: Re: EM Drive Developments
Post by: 93143 on 09/22/2014 11:31 pm
I'm a little dubious about Woodward's derivation myself (though I haven't had the time to acquire a full understanding of it), but that isn't the part I'd have picked on.  Energy is energy, is it not?  If you store energy in a capacitor, is not that energy electromagnetic, therefore localizable and gravitating?  If you cause a deformation in an object, can you not say the same thing about the deformation energy?

It seems to me that the "assumption" in question is not some sort of unjustifiable physical equivalence, but merely a supposition of 100% efficiency in part of the process, made for the sake of convenience rather than to trick the calculation into working out.

As always, I haven't fully explored the theory, so I could be misunderstanding...
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 12:23 am
I'm a little dubious about Woodward's derivation myself (though I haven't had the time to acquire a full understanding of it), but that isn't the part I'd have picked on.  Energy is energy, is it not?  If you store energy in a capacitor, is not that energy electromagnetic, therefore localizable and gravitating?  If you cause a deformation in an object, can you not say the same thing about the deformation energy?

It seems to me that the "assumption" in question is not some sort of unjustifiable physical equivalence, but merely a supposition of 100% efficiency in part of the process, made for the sake of convenience rather than to trick the calculation into working out.

As always, I haven't fully explored the theory, so I could be misunderstanding...

<<Energy is energy, is it not?>>
No, there are different types of energy and not distinguishing them brings confusion and inability to solve problems.  Particularly in this case where the types of energy differ by incommensurate orders of magnitude and type.


Rest Energy is not just any kind of energy.  It is defined as the product of mass and the square of light velocity.
This is a huge amount of energy (which you are never going to see significantly  released unless it is in a nuclear reaction).

The rest energy equivalent of just one gram (0.002 lb) of mass is equivalent to:

89.9 terajoules
25.0 million kilowatt-hours (≈ 25 GW·h)
21.5 billion kilocalories (≈ 21 Tcal)
85.2 billion BTUs

or to the energy released by combustion of the following:

21.5 kilotons of TNT-equivalent energy (≈ 21 kt)
568,000 US gallons of automotive gasoline

Would you equate potential energy fluctuations (weight times change in height) in a hydrogen balloon as it rises in the sky (such potential energy is completely insignificant compared to its rest energy) to the energy fluctuations due to a nuclear-fusion reaction  transforming hydrogen into helium, in which 0.7 percent of the original rest energy of the hydrogen is converted to other forms of energy ?

I don't understand what you mean by efficiency in this context (rest energy fluctuations). We are not talking thermodynamics here, we are talking the concept of rest energy and rest mass in Relativity.

Rest Energy = Rest mass c^2

Prof. Woodward derived the fluctuation in mass equation from Relativity theory, not from a thermodynamics theory.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/23/2014 01:11 am
... I guess discussing the derivation of Woodward's equations here is a bit useless?

If the math in the published papers is complete, then no, the discussion would be very useful.  Jose up there has suggested several instances where Woodward's assumptions are not theoretically nor mathematically justified.

O wait.  The good doctor Rodal is speaking, even as I type...

Dr. Woodward himself states "his leap of faith"

blah, blah, blah...

This is not the wording associated with a factual discovery, and it is painful to read.

The older experiment was to have proven that mass fluctutions exist, even tho the theory, per Jose's telling, does not accomodate mass fluctuations.  Remember, the results of that experiment never prduced a signal that was statistically, undeniably, and repeatably over the background noise.  If you look at the old thread, and the word that was to have come next, you will find little.  Paul March's last post on that thread.

...we are talking about gravity/inertial (G/I) field propulsion systems that use the ambient G/I field to generate the Mach-Effect (M-E) momentum transfers from the vehicle to the field and thus to the rest of the universe that created this field in the first place....

BTW, in Sonny White’s Quantum Vacuum Fluctuation (QVF) conjecture, Woodward’s G/I field is replaced with the Quantum Electrodynamic Vacuum field and the local reactive forces are generated and conveyed by momentum fluxes created in this QED vacuum field by the same process used to create momentum fluxes in the G/I field, but Sonny uses MHD plasma rules to quantify this local momentum interaction where Woodward does not.  As to whether Woodward’s or White’s approach to this propellantless propulsion problem turns out to be closer to our reality is yet to be determined, but obtaining comprehensive and high quality data on these types of propulsion devices is the only way we will find out.  In the end analysis though, Woodward and/or White’s conjectures may turn out to be wrong or just provide us some partial insights into the truths needed to build the impulse and warp drives needed to build our starships. ...

And we're to have a definitive answer to both concepts by the end of this summer. Is this correct?

Dr. White and I hope to have at least two Q-Thruster test articles run through their paces by the end of September.  We also hope to have started the warp-field interferometer work as well, but Sonny keeps getting dragged off to work on other more pressing NASA projects at the moment, so we will see how far that Eagleworks project gets when Sept shows up. 

As far as the M-E work is concerned, you'll have to ask Dr. Woodward what his M-E test schedule is going to be for the rest of this year, but at least he has already demontrated a 10uN thruster back in January that could be the M-E in action or it could be something else equally interesting, but he won't be able to tell IMO until he can figure out the frequency scaling of the thrust effect he is measuring with his current shuttler test article.  Whether Dr. Woodward will be able to accomplish that feat this year is TBD.

This current experiment is based on a different principle, and it's theoretical underpinnings haven't yet been discussed completely.

     I hate to say this, but it appears to me that what is happening is that microwaves are being bounced around in the chamber, being a tunnacated cone...

Just a note - you're describing Shawyer's EM-Drive specifically.  Woodward's M-E drive is a completely different animal...

O, mas faz mal.
Title: Re: EM Drive Developments
Post by: 93143 on 09/23/2014 01:17 am
Would you equate potential energy fluctuations (weight times change in height) in a hydrogen balloon as it rises in the sky (such potential energy is completely insignificant compared to its rest energy) to the energy fluctuations due to a nuclear-fusion reaction  transforming hydrogen into helium, in which 0.7 percent of the original rest energy of the hydrogen is converted to other forms of energy ?

No, because gravitational potential energy is not localizable and does not gravitate.

If you're going to complain about orders of magnitude, which is not what you seemed to be doing originally, you have to show why it's a problem with Woodward's theory, rather than just assuming people will fill in the blanks.

Because people will fill in the blanks, whether or not there is any merit in your argument.
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 01:37 am
...
O wait.  The good doctor Rodal is speaking, even as I type...
I'm copyrighting my name, so from now on you can only refer to Dr. X  :)
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 01:43 am
Would you equate potential energy fluctuations (weight times change in height) in a hydrogen balloon as it rises in the sky (such potential energy is completely insignificant compared to its rest energy) to the energy fluctuations due to a nuclear-fusion reaction  transforming hydrogen into helium, in which 0.7 percent of the original rest energy of the hydrogen is converted to other forms of energy ?

No, because gravitational potential energy is not localizable and does not gravitate.

If you're going to complain about orders of magnitude, which is not what you seemed to be doing originally, you have to show why it's a problem with Woodward's theory, rather than just assuming people will fill in the blanks.

Because people will fill in the blanks, whether or not there is any merit in your argument.

 Dr. Woodward himself wrote that it is a "wildly optimistic " and "arguable" assumption to equate fluctuations in rest energy to fluctuations in capacitor electric power input. Read his paper (Flux capacitors and the Origin of Inertia), he is the one "not filling the blanks" when he makes this (admittedly) unjustified assumption.  I don't have to fill the blanks for him.  You can also equate to each other all types of energy,  and put an efficiency term into Relativity's equations for rest energy and rest mass equation.  It is a free country, you can have your own Relativity theory.  It certainly does not make sense to me  :)
Title: Re: EM Drive Developments
Post by: Vultur on 09/23/2014 01:52 am
Yeah, I'm confused too. I thought mass-energy equivalence really did mean that a charged battery (or capacitor) would have (a very very very infinitesimally tiny amount) more mass than an uncharged one. Isn't that why photons have momentum, and so on?
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 02:06 am
very very very very very very very very very very very very very very .....infinitesimally teeny tiny as a proportion

Woodward's reference, Sciama, himself wrote in his 1953 paper that the variation of rho with time is negligible.

<<Since the change of rho [the density] with time is very small, the gravelectric part of the field is approximately>> p. 38 of ON THE ORIGIN OF INERTIA © Royal Astronomical Society  http://adsabs.harvard.edu/full/1953MNRAS.113...34S

Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 02:41 am
Notice that Woodward writes:

delta rho ~  (constant/(rho c2)) d2Eo/dt2 +..,
and  Eo=rho c2
therefore
delta rho ~  (constant/(Eo)) d2Eo/dt2 +..,

so it is the (fluctuation of the rest energy) divided by the (total rest energy) in the original equation

(more precisely, the second derivative of the rest-energy with respect to time, divided by the total rest-energy)

or, as he shows, the (fluctuation in rho) divided by (total rho) that matters.

So it is the fluctuation fractional amount that enters the equation (the change in rest energy divided by total rest energy). 
Title: Re: EM Drive Developments
Post by: 93143 on 09/23/2014 03:16 am
Dr. Woodward himself wrote that it is a "wildly optimistic " and "arguable" assumption to equate fluctuations in rest energy to fluctuations in capacitor electric power input.

No, what he said was: "Note that the assumption that all of the power delivered to the capacitors ends up as a proper energy density fluctuation is an optimistic, indeed, perhaps wildly optimistic, assumption.  Nonetheless, it is arguably a reasonable place to start."

That doesn't sound like a physics equivalence on thin ice to me.  That sounds like a caveat regarding practical considerations; that is, an efficiency argument.  The key phrase is "all of".

And as we've already established, the physics equivalence is sound.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/23/2014 12:32 pm
Dr. Woodward himself wrote that it is a "wildly optimistic " and "arguable" assumption to equate fluctuations in rest energy to fluctuations in capacitor electric power input.

No, what he said was: "Note that the assumption that all of the power delivered to the capacitors ends up as a proper energy density fluctuation is an optimistic, indeed, perhaps wildly optimistic, assumption.  Nonetheless, it is arguably a reasonable place to start."

That doesn't sound like a physics equivalence on thin ice to me.  That sounds like a caveat regarding practical considerations; that is, an efficiency argument.  The key phrase is "all of".

And as we've already established, the physics equivalence is sound.

Oooo.  Thanks for the rest of the context.

Even so:

0. The fluctuations are incredibly small.

1. The latest experimental results are inconclusive, and are completely different from earlier experiments.

2. Several of the experimentors refuse engagement, insisting upon arcane and arbitrary rules of third party engagement.

3. Other math areas in the theory are grey, including the 2/k argument.

4. It is still "arguably" a "reasonable place to start"; therefore argue that starting point.

5. Inertia is not understood.

6. If there was an FTL period of expansion in the cosmos early on, how did causality get broken, and what applicability could there be to the idea of inertial action at a distance.

7. "Wildly optimistic" is still an assumption, albeit seen in better relationship to the whole argument.

8. Comme toujours, directement à partir du traducteur, snappy répliques de langue romantiques ont une applicabilité universelle.
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 12:38 pm
If an isolated capacitor is to be at rest, there must be internal mechanical stresses that are equal and opposite to the electromagnetic ones.

 One has to consider the mechanical energy-momentum stress tensor as well.  Sometimes people assume that the capacitor plates are held apart without completely examining how they are held in place, thus ignoring the stresses involved.

The mechanical energy density is Eo =  ρo c2,  where ρo = mass density when there is no electric field in the capacitor. 

The total energy-momentum-stress tensor is the sum of the mechanical and electromagnetic  tensors.   In the rest frame (*) of the capacitor the total mass density in the rest frame is

 ρo* + E2/(8 Pi c2)

where E is the electric field.  It is completely unjustified to equate fluctuations in E with fluctuation in Eo.   Sciama neglects fluctuations in Eo =  ρo c2, as just every other physicist does (unless dealing with reactions like nuclear reactions, etc.) and Sciama explicitly states this in his 1953 paper (that Woodward uses as a reference).  Now I understand why the physics community at large has ignored Prof. Woodward's theory of mass fluctuations, as the assumption to equate fluctuations in E with fluctuation in Eo is indeed, unjustified for a mundane capacitor.

________________________

The total energy of a body moving with velocity v (lower than c) and with mass m is the sum of its rest energy m c2 plus its kinetic energy, m v2/2:

total energy = (rest energy ) + ( kinetic energy)

total energy = m c2 + m v2/2

This is actually an approximation for speeds significantly lower than light, see   (Low speed expansion section): 

http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence


Usually fluctuations in rest energy are ignored:

<<The classical energy equation ignores  the rest energy m c2 part...Since only changes in energy affect the behavior of objects, whether we include the [rest energy] m c2 part makes no difference, since it is [practically] constant. For the same reason, it is possible to subtract the rest energy from the total energy in relativity. >>

Again, equating "fluctuations in rest energy", which are known to be extremely small (Sciama himself ignores them ! ), to fluctuations in the Electric power input to a capacitor, is an assumption that Prof. Woodward himself states to be "wildly optimistic" and "arguable".  I argue that it is an unjustified, dangerous assumption that is leading some readers to very unphysical expectations (the unphysical expectation that fluctuations in electric power input to a mundane capacitor can result in measurable thrust forces useful for "propellant-less" space propulsion)
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 01:59 pm
Proposing the inclusion of an "efficiency" term (in a derivation using energy and mass from Relativity, never involving any  thermodynamics in the derivation) is like somebody postulating their own Relativity theory predicting some unusual prediction that can be experimentally tested.  When the experiments show that the prediction is not confirmed, but the experiments show a much lower uncertain level, to come back and claim some unknown "efficiency" being responsible for the much lower uncertain value.

Einstein's theory of General Relativity predicted the precession of the perihelion of Mercury.  He didn't get to put an "efficiency" term on the precession of the perihelion of Mercury to accommodate to experimental results.

Prof. Woodward himself does not use any "efficiency" in his peer-reviewed papers that I have read - and that goes to Prof. Woodward's credit, because in my opinion to place an "efficiency" term in his theory would be tantamount with a "fudge-factor" that does not belong in a derivation from Relativity.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/23/2014 01:59 pm
Quote from: Jose
Sometimes people assume that the capacitor plates are held apart without completely examining how they are held in place, thus ignoring the stresses involved.

Aw jeeze, man!  I've been ignoring capacitors for years.  I'm not starting to stress about them now.  I just don't have, well, the capacity.  Plus, French is hard!

As an aside, my romantic interests, which include the romantic languages, rest completely upon a world at peace.  For that matter, so too do all on this forum, regardless of their interests.

Note 17 of the oracle's article (http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence) above, brings this need into the forefront of the  careful reader's mind:

Quote from: Alfred E.
A.Einstein "E = mc2: the most urgent problem of our time" Science illustrated, vol. 1 no. 1, April issue, pp. 16–17, 1946 (item 417 in the "Bibliography"

Still is.

Considering nuclear proliferation and the verifiable rise in violence in the world's hotspots, it is not clear how much longer we can expect the world to be largely at peace.

Just sayin'.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/23/2014 02:06 pm
...the unphysical expectation that fluctuations in electric power input to a mundane capacitor can result in measurable thrust forces useful for "propellant-less" space propulsion...

I point out that, unless there is newer, unpublished experimental work which has been accomplished using the "flux capacitor", that this approach seems to have been abandoned.  Furthermore, the current experimental apparatus looks a lot like Shawyer's EM device, known to be based upon faulty theory.

No news is no news.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/23/2014 02:49 pm
Thanks to Jose... errr... Dr. X, for suggesting a read of the oracle.

http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

Quote from: the oracle
When an object is pulled in the direction of motion, it gains momentum and energy, but when the object is already traveling near the speed of light, it cannot move much faster, no matter how much energy it absorbs. Its momentum and energy continue to increase without bounds, whereas its speed approaches a constant value—the speed of light. This implies that in relativity the momentum of an object cannot be a constant times the velocity, nor can the kinetic energy be a constant times the square of the velocity. ...

A property called the relativistic mass is defined as the ratio of the momentum of an object to its velocity. ...

The fact that the released energy is not easily weighed in many such cases, may cause its mass to be neglected as though it no longer existed. This circumstance has encouraged the false idea of conversion of mass to energy, rather than the correct idea that the binding energy of such systems is relatively large, and exhibits a measurable mass, which is removed when the binding energy is removed. ...

In physics, there are two distinct concepts of mass: the gravitational mass and the inertial mass. The gravitational mass is the quantity that determines the strength of the gravitational field generated by an object, as well as the gravitational force acting on the object when it is immersed in a gravitational field produced by other bodies. The inertial mass, on the other hand, quantifies how much an object accelerates if a given force is applied to it. ...

Due to inefficient mechanisms of production, making antimatter always requires far more usable energy than would be released when it was annihilated. ...

We walked up and down in the snow, I on skis and she on foot. ...and gradually the idea took shape... explained by Bohr's idea that the nucleus is like a liquid drop; such a drop might elongate and divide itself... We knew there were strong forces that would resist, ..just as surface tension. But nuclei differed from ordinary drops. At this point we both sat down on a tree trunk and started to calculate on scraps of paper. ...the Uranium nucleus might indeed be a very wobbly, unstable drop, ready to divide itself... But, ...when the two drops separated they would be driven apart by electrical repulsion, about 200 MeV in all. Fortunately Lise Meitner remembered how to compute the masses of nuclei... and worked out that the two nuclei formed... would be lighter by about one-fifth the mass of a proton. Now whenever mass disappears energy is created, according to Einstein's formula E = mc2, and... the mass was just equivalent to 200 MeV; it all fitted!


Thought experimenting for a bit on my take on the idea alone of a "flux capacitor".

1. Ignore the concept of "free energy", from the quantum whatever, since that concept has not been demonstrated in reality.

2. Therefore, the idea is to convert electricity to free space forward momentum by other than rotary motion.

3. Allow that the electricity generation device is available, and can be included in the spacecraft design.

4. Contemplate only getting around in the solar system, from an L-point, with chemical rocketry doing the initial lifting.

5. Abandon interstellar travel crockery.

6. Allow that the thrust of the flux capacitor can be scaled appropriately.

7a. Now we can focus on whether the tiny (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260936#msg1260936) mass fluctuations exist, and can be detected, since the only way to pragmatically design one's spacecraft, is to apply real thrust numbers.  Ipso fatso:

7b. AIUI, it is conjectured that the interstitial atomic bonds in the capacitor move at relativistic speeds, over small distances, with properly timed alternating, opposed electrical signals.  Because it is supposed that there is a time lag between the extemes of motion in this cycle, that the electrical signals can be timed so as to "push heavy" in one dirrection, and "pull light" in the other.

8. I believe that I have given a dispassionate summary of how the flux capacitor is supposed to work.   

9. If such an effect can be shown, it does not seem credible that it could be scaled to a useful device.

10. Standard closing.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/23/2014 03:10 pm
Still just poking around.  This ref from another list (Polywell ?)
http://www.ccsenet.org/journal/index.php/apr/article/view/10455

Suggests to me that the dielectric may not be there because of "flux capacitors", but rather to make that surface look as close to a superconducive surface as possible (perfect reflectivity).  This is done all the time by adding a dielectric layer onto an existing reflective surface.  (in extreme cases we've made neutron mirrors w/ 1300 layers, but I digress)  You need all 3 complex indices at the wavelength of interest to get "perfect" reflectivity.  Typical telescope reflector is Al/SiO2,  etc etc

No way of telling unless someone tells what the model is.

Could be just a big case of mirror charge attraction ?
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 03:14 pm
Still just poking around.  This ref from another list (Polywell ?)
http://www.ccsenet.org/journal/index.php/apr/article/view/10455

Suggests to me that the dielectric may not be there because of "flux capacitors", but rather to make that surface look as close to a superconducive surface as possible (perfect reflectivity).  This is done all the time by adding a dielectric layer onto an existing reflective surface.  (in extreme cases we've made neutron mirrors w/ 1300 layers, but I digress)  You need all 3 complex indices at the wavelength of interest to get "perfect" reflectivity.  Typical telescope reflector is Al/SiO2,  etc etc

No way of telling unless someone tells what the model is.
Interesting:  <<During the discharges, the devices were strongly pushed in the direction opposed to the electron flow. The layered devices were apparently propelled by their emission of a momentum-bearing flux of an unknown nature.>>

But this reference is  for <<Devices at 77 K>>.  While the NASA and Woodward experiments are at room temperature  298 K, ~220 K degrees above that reference.

It doesn't make sense to me that the PTFE ("Teflon") in the NASA experiments would be in a superconducting state. All the experimental data available shows that PTFE is not superconducting at room temperature

But, as difficult it is to digest invoking superconductivity at room temperature, this is at least much more palatable than invoking Woodward's assumptions (equating fluctuating input electric power of a few watts with fluctuations in rest energy -without nuclear reactions-) or White's assumption (virtual particles from the quantum vacuum made real in a few-watts mundane microwave instead of a petawatt class picosecond laser)

Very strange (but understandable, given the unsatisfactory nature of Woodward and White's explanations) to witness the desperate attempts that people in other forums (polywell in this case) must go through to try to justify the microNewton forces measured at NASA using an inverted torsional pendulum known to exhibit parasitic modes and therefore needing magnetic damping....

Title: Re: EM Drive Developments
Post by: aero on 09/23/2014 03:27 pm
Well, if the RF field can not turn the electron stream without a reacting force, then that leaves

1. Dr. White's idea of the electrons/protons appearing and disappearing from/to the quantum vacuum, and
2. The alternative of the real electrons disappearing into the quantum vacuum.

The first idea has been discounted by critics. The second idea has not been put forward, to my knowledge.

Of course there are the ideas put forth by Shayer, and by the Chinese experimental group, as well as new ideas that might be held Boeing and Cannae groups.

Don't forget (what to me looks like) the (most likely) explanation:

the measured thrust forces are due to spurious testing effects and these tested EM drives will not generate any (translational motion) thrust in space.

Speaking to that- What do you suppose the chances are that this is just a very obscure implementation of a "Dean Drive?"

Obviously the reaction is not due to bouncing on the ground. They used liquid metal contacts to avoid forces transmitted via the conductors. What about forces transmitted via the RF wave guide or was that question addressed already? I note that the wave guide is common to all of the devices but the attachment coordinates do seem to be different with different devices.
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 03:35 pm
Well, if the RF field can not turn the electron stream without a reacting force, then that leaves

1. Dr. White's idea of the electrons/protons appearing and disappearing from/to the quantum vacuum, and
2. The alternative of the real electrons disappearing into the quantum vacuum.

The first idea has been discounted by critics. The second idea has not been put forward, to my knowledge.

Of course there are the ideas put forth by Shayer, and by the Chinese experimental group, as well as new ideas that might be held Boeing and Cannae groups.

Don't forget (what to me looks like) the (most likely) explanation:

the measured thrust forces are due to spurious testing effects and these tested EM drives will not generate any (translational motion) thrust in space.

Speaking to that- What do you suppose the chances are that this is just a very obscure implementation of a "Dean Drive?"

Obviously the reaction is not due to bouncing on the ground. They used liquid metal contacts to avoid forces transmitted via the conductors. What about forces transmitted via the RF wave guide or was that question addressed already?

Yes, NASA in their report did not perform a (parasitic and coupling motion) analysis of their experimental set-up, nor an analysis of interaction between the diverse electric power components and the magnetic damping.  As I have posted previously, the scientific community is going to ignore these tests until at least:

1) The tests are independently verified in a hanging pendulum of the type used to perform gravitational (inverse square law) tests as the one suggested to be performed at John Hopkins with their Cavendish type pendulum. 

2) If they insist in performing further tests at JPL with an inverted pendulum, JPL should modify their inverted pendulum (as already done at the Aeronautics and Astronautics department at MIT by Prof. Martinez-Sanchez) to ensure that the EM drive remains horizontal at all times (to eliminate the parasitic swinging modes of the pendulum rotating the supporting platform).

3) To have all electric power components of the drive together-on-one-side in the supported platform of the measuring equipment.
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 04:09 pm
The practical problem with independent verification (at John Hopkins or other universities) is that the scientific community has dismissed the NASA propellant-less tests (either vocally as done by John Baez and Sean Carroll, or quietly as done by most other academics in Aerospace Engineering -and quietly dismissing these results at other NASA propulsion centers-).  The academic community -particularly nowadays- knows that it is not considered to be an advancement to their career to produce independent experimental data that nullifies esoteric claims (claims that run contrary to conservation of momentum and known physics) that the rest of the community will meet with "I could have told you that".  So academics at MIT, Stanford, CalTech, etc., are negatively motivated, they actually have a disincentive  to spend their time and effort to examine these exotic claims. 

It was a different case for Cold Fusion because in 1989 Martin Fleischmann -the Cold Fusion proponent- was considered to be one of the world's leading electrochemists and because the world has much more interest in a cheap form of power production than they have on a quicker trip to Enceladus.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/23/2014 04:23 pm
We could do that here (non-academic) but who in their right mind would put up the 100k or more to cover the time and overhead even if it was done at cost ?
Title: Re: EM Drive Developments
Post by: mheney on 09/23/2014 05:23 pm
We could do that here (non-academic) but who in their right mind would put up the 100k or more to cover the time and overhead even if it was done at cost ?

I dunno - the folks at "Solar FREAKIN' Roadways" has raised $2.2M via indegogo:
https://www.indiegogo.com/projects/solar-roadways (https://www.indiegogo.com/projects/solar-roadways)
even though the concept has been panned by Real Civil Engineers (tm).

I wouldn't be surprised if a professionally done (and mildly over-hyped) video couldn't raise a couple hundred kilobucks ...

Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/23/2014 05:32 pm
Always a thought !

Still pokin', COMSOL EM models ?

http://www.microwavejournal.com/ext/resources/BGDownload/4/d/3D%20Electromagnetic%20Field%20Simulation.pdf?1326826605

"Respective to the boundary conditions, the
walls of the cavity are considered as perfect
conductors, represented by the boundary
condition
0
=
×
E
n
r
r
. That is, the tangential
electric field component is zero. To simulate the
temperature variation in a ceramic material in the
cavity, we used a symmetry cut as a mirror
symmetry for the electric field, which is
represented by the boundary condition
0
=
×
H
n
r
r
. "

Hmmmm.  Need to figure out how to copy formulas, but you get the idea.
Title: Re: EM Drive Developments
Post by: raketa on 09/23/2014 05:44 pm
Photon could reach speed of light because, photon weight is 0 if it didn't move. Photon probably didn't consist Higgs particle that carry weight property base on the today's understanding. When speed of matter reach light could be that instead of increasing speed, it is feeding generation of Higgs particle and make it heavier and heavier. Could it be posible that process will be suppress?
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 05:59 pm
Always a thought !

Still pokin', COMSOL EM models ?

http://www.microwavejournal.com/ext/resources/BGDownload/4/d/3D%20Electromagnetic%20Field%20Simulation.pdf?1326826605

"Respective to the boundary conditions, the
walls of the cavity are considered as perfect
conductors, represented by the boundary
condition
0
=
×
E
n
r
r
. That is, the tangential
electric field component is zero. To simulate the
temperature variation in a ceramic material in the
cavity, we used a symmetry cut as a mirror
symmetry for the electric field, which is
represented by the boundary condition
0
=
×
H
n
r
r
. "

Hmmmm.  Need to figure out how to copy formulas, but you get the idea.

Excellent source.  Thank you for posting high quality materials and high quality thoughts  @Notsosureofit   :)

This addresses my suspicion of how people are modeling the walls with COMSOL: <<the walls of the cavity are considered as perfect conductors, represented by the boundary condition>>.  Probably NASA Eagleworks did the same for the Copper walls.  But what about simulating the ends, that seem to have PCB circuit board on them ?

The conclusions:
<<The simulated results, obtained using COMSOL software, showed that, both the complex permittivity (real and imaginary parts) and the frequency of the microwave source have a strong influence on the field spatial distribution. This dependence could have important consequences in efforts to optimize the conditions for processing materials using microwave radiation.
We can obtain the evolution of the thermal profile of the sample using the energy absorption, which can be computed from those electromagnetic simulations.
To illustrate the useful of the used numerical technique, the thermal behaviour in a ceramic material was simulated, where 4 hot spot’s was observed. This phenomenon presents a challenge for microwave engineers, since sample cracking are often exhibited, mainly because the formation of hot spot’s due an inhomogeneous electromagnetic field distribution.>>

[Dielectric resonator] sample cracking means the strong possibility of dielectric breakdown and the field emission of real electrons, as we had discussed earlier on !
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 06:19 pm
But, if electrons are emitted by field emission from a dielectric-resonator experiencing breakdown under the electric field, what happens to the electrons in the air?  Is the air also ionized by the electric field?  How could that generate propulsion, unless we have a leaky microwave cavity ?
Title: Re: EM Drive Developments
Post by: JasonAW3 on 09/23/2014 06:36 pm

[Dielectric resonator] sample cracking means the strong possibility of dielectric breakdown and the field emission of real electrons, as we had discussed earlier on !

So, the actual thrust seen is essentially like the recoil from some sort of electron gun?

     Doesn't this indicate that thrust is being produced by the decay of matter from a microwave gun?

     Wouldn't that make this a sort of highly effecient ion drive?  Much lower power requirements, solid matter being converted to high energy ions from a solid instead of from a gas.  That is, If I understand what you're saying correctly.

     If so, then they DO has a sort of working high effeciency EM drive that is essentially a Solidstate Ion Thruster.

     Or am I not understanding what you're saying.
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 06:41 pm

[Dielectric resonator] sample cracking means the strong possibility of dielectric breakdown and the field emission of real electrons, as we had discussed earlier on !

So, the actual thrust seen is essentially like the recoil from some sort of electron gun?

     Doesn't this indicate that thrust is being produced by the decay of matter from a microwave gun?

     Wouldn't that make this a sort of highly effecient ion drive?  Much lower power requirements, solid matter being converted to high energy ions from a solid instead of from a gas.  That is, If I understand what you're saying correctly.

     If so, then they DO has a sort of working high effeciency EM drive that is essentially a Solidstate Ion Thruster.

     Or am I not understanding what you're saying.
Take a look at my subsequent comment:

<<But, if electrons are emitted by field emission from a dielectric-resonator experiencing breakdown under the electric field, what happens to the electrons in the air?  Is the air also ionized by the electric field?  How could that generate propulsion, unless we have a leaky microwave cavity ?>>

These are my malformed , incomplete, thoughts in "poking around" looking for different explanations of the measurements. 

If the propulsion is the result of ionized air leaking from the cavity, I see this as much less effective than present ion rockets.  Also take into account that they tested thrust pulses for only ~30 sec duration and that would not get us anywhere.  A cracked dielectric resonator emitting electrons and/or ionization of air won't work long enough or effectively enough...

Also as far as specific force, the results from the Cannae and Frustum testing were not too encouraging.  The Boeing/DARPA specific force tests show an impulse instead of a rectangular pulse.  The trips to the moons of Saturn and Jupiter are predicated on very optimistic extrapolations...
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/23/2014 07:13 pm
Where are the Boeing/DARPA specific force tests ?
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 07:20 pm
Where are the Boeing/DARPA specific force tests ?
Take a look at:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255615#msg1255615

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255953#msg1255953

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1256192#msg1256192

Boeing/DARPA device:

SPECIFIC FORCE = 1 to 20 N/kW (225 000 to 4.5 million times larger than a photon rocket)



Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 07:43 pm
 slide 40 of Dr. White's presentation http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf )
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 07:50 pm
Also see this, which reproduces the contents of the Boeing/DARPA information supplied by Dr. White:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255210#msg1255210
Title: EM Drive Developments
Post by: Star One on 09/23/2014 08:09 pm
The practical problem with independent verification (at John Hopkins or other universities) is that the scientific community has dismissed the NASA propellant-less tests (either vocally as done by John Baez and Sean Carroll, or quietly as done by most other academics in Aerospace Engineering -and quietly dismissing these results at other NASA propulsion centers-).  The academic community -particularly nowadays- knows that it is not considered to be an advancement to their career to produce independent experimental data that nullifies esoteric claims (claims that run contrary to conservation of momentum and known physics) that the rest of the community will meet with "I could have told you that".  So academics at MIT, Stanford, CalTech, etc., are negatively motivated, they actually have a disincentive  to spend their time and effort to examine these exotic claims. 

It was a different case for Cold Fusion because in 1989 Martin Fleischmann -the Cold Fusion proponent- was considered to be one of the world's leading electrochemists and because the world has much more interest in a cheap form of power production than they have on a quicker trip to Enceladus.

That's depressing to read, sounds like its going to be hard to get anyone to stick their head above the parapet and actually look into this from a neutral third party viewpoint.
Title: Re: EM Drive Developments
Post by: Rodal on 09/23/2014 08:23 pm
That's depressing to read, sounds like its going to be hard to get anyone to stick their head above the parapet and actually look into this from a neutral third party viewpoint.

1) I think that independent testing with null results of EM drives has already been done and reported, utilizing a classical testing device.  I will be posting shortly negative results already reported in the literature, performed by a third party, that I am presently reviewing.

2) Regardless of positive or negative results by third parties, it is noteworthy that Boeing/DARPA as recently as 2013 had their device tested at NASA/Eagleworks who reported a specific force orders of magnitude above the 2014 campaign featuring the Cannae and Frustum devices (albeit with an impulse response rather than a rectangular pulse, which may be problematic for practical propulsion applications).  If the Boeing/DARPA results were indeed valid, I think that both Boeing and DARPA would be pursuing further, perhaps secret, work, don't ya think?
Title: Re: EM Drive Developments
Post by: Star One on 09/23/2014 08:38 pm

That's depressing to read, sounds like its going to be hard to get anyone to stick their head above the parapet and actually look into this from a neutral third party viewpoint.

1) I think that independent testing with null results of EM drives has already been done and reported, utilizing a classical testing device.  I will be posting shortly negative results already reported in the literature, performed by a third party, that I am presently reviewing.

2) Regardless of positive or negative results by third parties, it is noteworthy that Boeing/DARPA as recently as 2013 had their device tested at NASA/Eagleworks who reported a specific force orders of magnitude above the 2014 campaign featuring the Cannae and Frustum devices (albeit with an impulse response rather than a rectangular pulse, which may be problematic for practical propulsion applications).  If the Boeing/DARPA results were indeed valid, I think that both Boeing and DARPA would be pursuing further, perhaps secret, work, don't ya think?

And you've just highlighted another frustration with this that there is the suggestion of a forest of NDAs around this work. We could end up in the situation of positive results being produced but no one outside of select few ever knowing about it.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/23/2014 09:50 pm
Or a lot of negative results being kept secret while positive ones (or apparently positive ones) are published.

Was thinking : how the presence or absence of the dielectric part alters the coupling of the generator with the resonant cavity ? And in particular how much power feedback is there from the cavity to the generator and how the absence of dielectric might change that ?

The electromagnetic fields in the cavity are excited via external coupling. An external power source is usually coupled to the cavity by a small aperture, a small wire probe or a loop.[2] External coupling structure has an effect on cavity performance and needs to be considered in the overall analysis.[3] (http://en.wikipedia.org/wiki/Microwave_cavity#Theory_of_operation)

Even if very high Q of 1e6 is done, the steady state when power loss = power input (of the wave) is reached very quickly, the time it takes light to bounce 1e6 times along the cavity, say 1ns for a 30cm trip, that's about 1ms to reach this equilibrium. The total RF EM energy in the cavity then stabilizes at (power x 1ms), at 20W that's .02 J

System wide (generator +cavity but not the chamber) 20W DC input, 20W (thermal+radiation) output
The thermal effect is at first (temperature equilibrium would have a time constant much longer than 1ms) at each location a constant rate of temperature change (inversely proportional to thermal capacity). Radiations (leaked) would be much faster at filling the cavity around the system (chamber) and reach equilibrium at a given energy density (different because different volume, smaller leaked input power and probably different Q factor). At which point (when the chamber reaches RF equilibrium) this power fraction of power radiated by a leak of the system would be all thermal output to heat the outer walls of the system and the inner walls of the chamber at constant rate also. I'm assuming the chamber is thick enough a conducting vessel to not leak any RF radiation. So after at most a few ms, the 20W DC power input is entirely dissipated thermally, with at start (after a few ms and before thermal conductivity/convection/IR radiation starts to even out the temperatures) constant rates of temperature change at every location of system (generator + cavity) and experiment overall (+chamber and fixed parts).

What am I aiming at ? Don't know... just saying, follow the power system wide, and in particular don't expect the generator to cavity link to be a one way power transmission line : this is a coupling. And in this coupling the presence or absence of dielectric thing might make a difference, and we know from first hand (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1254143#msg1254143) that power radiating (IR radiation) from the generator heats the flex bearings to affect measurements at a level comparable in magnitude to the measured thrust signals (albeit not in a way that could readily explain a square signal, just a ramp up or down...)

edit : I should add that any effect due to something happening at the generator would hardly be compatible with the apparent fact that the thrust is reversed when turning the cavity alone...

Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/24/2014 01:31 pm
Reviews of Modern Physics vol 36 pp463 and 1103

"The Physical Structure of General Relativity"

$35 gets you thru the paywall for this article:

http://journals.aps.org/rmp/abstract/10.1103/RevModPhys.36.463

The Erratum, you can have for free.  Anybody care to share the article?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/24/2014 01:41 pm
Or a lot of negative results being kept secret while positive ones (or apparently positive ones) are published.

Yeah, there's that too.  Remember way back when, when the Russians and us too, I suppose, were investigating mental telepathy as a "secret" weapon?  Part of the due diligence of national security is to test seemingly weird things to verify whether or not there's "science" backing them up.  Obviously, there would be great security issues as well as commercial issues surrounding a propellantless drive.

Point being, NDA's prove nothing about the underlying science one way or the other.  Everybody is "free" to develop warp drive in their garage.  The only rules that you have to follow apply to all matter in the universe.

Still, over the last several dozen pages, there are a raft of "special exceptions" being raised by posters.  What about the cavity? The boundary conditions? The Comsol model?  The dielectric?  The sense I get is more along the lines of people grasping at straws, in the "hopes" that there is a "there" there, regarding this EM drive thingy.

There are all of these allusions to deep knowledge of the arcana surrounding the topic, but there is no coherent line of argument being made on this thread which starts at:

Quote from: Sciama 1953
If the rest of the universe determines the inertial frames, it follows that inertia is not an intrinsic property of matter, but arises as a result of the interaction of matter with the rest of the matter in the universe.

... and which concludes with propellantless propulsion.

Rodal has been patiently addressing each of the special execptions that posters have raised; exceptions which would seemingly allow a loophole explaining the reported thrust anomalies.  In all of these cases, the posters appear to accept the apparently faulty inverted pendulum as being sufficiently accurate in its thrust reporting.

It's totally understandable from an emotional standpoint, why the experimentors hesitate to address the multiple skeptical arguments questioning their procedures and math, preferring to quietly assert that still, the device moves, though no other sees the movement.

Sheesh.  <- Translate that!
Title: Re: EM Drive Developments
Post by: Rodal on 09/24/2014 02:01 pm
Or a lot of negative results being kept secret while positive ones (or apparently positive ones) are published.

Yeah, there's that too.  Remember way back when, when the Russians and us too, I suppose, were investigating mental telepathy as a "secret" weapon?  Part of the due diligence of national security is to test seemingly weird things to verify whether or not there's "science" backing them up.  Obviously, there would be great security issues as well as commercial issues surrounding a propellantless drive.
.........................

Quote from: Sciama 1953
If the rest of the universe determines the inertial frames, it follows that inertia is not an intrinsic property of matter, but arises as a result of the interaction of matter with the rest of the matter in the universe.

...............
It's totally understandable from an emotional standpoint, why the experimentors hesitate to address the multiple skeptical arguments questioning their procedures and math, preferring to quietly assert that still, the device moves, though no other sees the movement.

Sheesh.  <- Translate that!

Totally agree with #1 (since China is examining Shawyer's microwave drive, it is understandable that NASA is requested to do the same here for microwave drives)

and with #2, excellent quote:  according to Sciama "inertia is not an intrinsic property of matter", therefore Sciama's inertia cannot be a constitutive material property (it cannot be like the modulus of Elasticity in Stress-Strain equations or the Dielectric constant in Maxwell's expressions).  Therefore if one uses Sciama's model, one cannot simultaneously add additional material-dependent "fudge factors" in order to explain why experimental results don't agree with theory.  According to Sciama, inertia is not a material property, period, hence no additional material-dependent constants ("fudge factors") are allowed in his theory .

Dont't agree with your final note, John, [EDIT: ""X" has been patiently addressing each of the special execptions that posters have raised"] this is a joint [NASAspaceflight] community effort, of which I have been only a very small part and late to join.  Thanks to all of you who have expressed your views (both agreeing and disagreeing with me): I have learnt a lot about these experiments from joining this forum.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/24/2014 02:26 pm
Dont't agree with your final note, John, this is a joint community effort, of which I have been only a very small part and late to join.  Thanks to all of you who have expressed your views (both agreeing and disagreeing with me): I have learnt a lot about these experiments from joining this forum.

Not quite sure I understand this.  Certainly, this is a community effort, and your patience and thouroughsity are appreciated by all and by me.  but I was referring to the experimentors.

I do note that I have found a weakness in your translation skills!  Sheesh.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/24/2014 02:30 pm
#2  The other side of the coin is that you can say the same thing about the Higgs field.
Title: Re: EM Drive Developments
Post by: Rodal on 09/24/2014 02:45 pm
#2  The other side of the coin is that you can say the same thing about the Higgs field.
Good point, but the Higgs field is not introduced as a "fudge factor" multiplying expressions derived from General Relativity.  If a theory (like Woodward's) that is derived from Sciama does not agree with experiments (because it gives changes in mass that are much lower than predicted or non-existent), it is not proper to try to fix it simply by introducing a "fudge factor".

EDIT: I am referring to the two "efficiency" fudge factors "eta1" and "eta2" with which Buldrini for example attempts to "fix" Woodward's theory on page 77 of this reference:  http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=13020.0;attach=484587  .  Buldrini himself admits this is a "rough" attempt to fix the theory.  The "efficiency parameter" values are of an unknown nature and unknown magnitude, admitted by Buldrini as varying between 0 and 1.  Obviously, if these fudge factors are zero, there is no Woodward effect.  This is evidently a very unsatisfactory way to proceed in a derivation that pretends to originate from Sciama's Relativity Mach effect, as Sciama himself has stated that his Machian effect is not an intrinsic material property, and theories that are contradicted by experiment shouldn't be fixed with fudge factors.

Moreover, it is somewhat ironic to refer to Sciama's theory, whose intention was to remove inertia as an intrinsic property, and to end up with having to introduce (not one but) two additional intrinsic fudge factors of an unknown nature and unknown magnitude.
Title: Re: EM Drive Developments
Post by: Rodal on 09/24/2014 02:47 pm
....

I do note that I have found a weakness in your translation skills!  Sheesh.


EDIT: I was referring to your statement: <<"X" has been patiently addressing each of the special execptions that posters have raised>>. 

Ciao e benvenuto  :)
Title: Re: EM Drive Developments
Post by: 93143 on 09/24/2014 09:25 pm
#2  The other side of the coin is that you can say the same thing about the Higgs field.
Good point, but the Higgs field is not introduced as a "fudge factor" multiplying expressions derived from General Relativity.  If a theory (like Woodward's) that is derived from Sciama does not agree with experiments (because it gives changes in mass that are much lower than predicted or non-existent), it is not proper to try to fix it simply by introducing a "fudge factor".

EDIT: I am referring to the two "efficiency" fudge factors "eta1" and "eta2" with which Buldrini for example attempts to "fix" Woodward's theory on page 77 of this reference:  http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=13020.0;attach=484587  .  Buldrini himself admits this is a "rough" attempt to fix the theory.  The "efficiency parameter" values are of an unknown nature and unknown magnitude, admitted by Buldrini as varying between 0 and 1.  Obviously, if these fudge factors are zero, there is no Woodward effect.  This is evidently a very unsatisfactory way to proceed in a derivation that pretends to originate from Sciama's Relativity Mach effect, as Sciama himself has stated that his Machian effect is not an intrinsic material property, and theories that are contradicted by experiment shouldn't be fixed with fudge factors.

Moreover, it is somewhat ironic to refer to Sciama's theory, whose intention was to remove inertia as an intrinsic property, and to end up with having to introduce (not one but) two additional intrinsic fudge factors of an unknown nature and unknown magnitude.

Did you even read the reasoning given for those "fudge factors"?  In these drives, the "Mach effect" is supposedly being accessed indirectly by dynamic manipulation of materials via electromagnetic fields, the effectiveness of which necessarily depends on their properties (as well as on the precision of the resonance matching in the system, and the efficiency of the EM equipment in providing a clean signal).  Your argument is a non sequitur.
Title: Re: EM Drive Developments
Post by: Rodal on 09/24/2014 09:49 pm
Did you even read the reasoning given for those "fudge factors"?  In these drives, the "Mach effect" is supposedly being accessed indirectly by dynamic manipulation of materials via electromagnetic fields, the effectiveness of which necessarily depends on their properties (as well as on the precision of the resonance matching in the system, and the efficiency of the EM equipment in providing a clean signal).  Your argument is a non sequitur.

Not only I read it, but I provided the link to the actual paper (from an e-only, open access product focusing entirely on publishing conference proceedings ) where the author himself has the honesty and forthrightness to admit that as a first rough attempt to address the issues with Woodward's formulation, it seems reasonable to the author to insert into the mass fluctuation equation two efficiency parameter ranging between 0 and 1.  For a value of zero, there is no Woodward effect.  The author is right that it is rough to have to introduce such efficiency fudge factors.
Title: Re: EM Drive Developments
Post by: cuddihy on 09/24/2014 10:05 pm
How is Buldrini's fudge factor different than the introduction of the Hubble constant?
Title: Re: EM Drive Developments
Post by: Rodal on 09/24/2014 10:18 pm
How is Buldrini's fudge factor different than the introduction of the Hubble constant?
It differs in that

A) Hubble's law was first derived by Lemaître from General Relativity where he proposed the expansion of the universe and estimated the value of the rate of expansion. It was not a multiplicative fudge factor with possible values ranging from 0 to 1. (Lemaître also proposed what became known as the Big Bang theory of the origin of the Universe.)

B)  Two years later Edwin Hubble determined a more accurate value for the Hubble constant based on actual measurements of the expansion of the Universe, again not a multiplicative fudge factor with possible values ranging from 0 to 1.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/25/2014 02:12 pm
"In these drives, the "Mach effect" is supposedly being accessed indirectly by dynamic manipulation of materials via electromagnetic fields, the effectiveness of which necessarily depends on their properties."

While it is true that it is the effectiveness of the properties of the materials used which determine the effectiveness of the forward momentum developed, it is also true that if the momentum generating device does not exist, then no material properties pertain to its effectiveness.

Example one: H2/O2 rocket engines are far more effective than compressed hummingbird wing/O2 rocket engines.  Both of these rocket engines can be made and demonstrated, and their relative ISP's calculated with great accuracy.

Example two:  No matter what I feed my pig, it will not fly until I pick it up and toss it.  The pig does not have any flying properties.  It may be possible to design and build a pig with sufficiently capable wings, but that theory of operation has not yet been developed.

Mach Effect drives will not work by tweaking an equation by an arbitrarily optimistic fudge factor.  If the theory behind the operation is not soundly based on the way the universe actually works, no materials will suffice to make an M-E device work.

Example three: Coherent mathematical equation systems can be developed without regard to pragmatic utility of those systems in the universe as it exists.

In this "community effort", there is too much grasping of straws; straws which assume too much of unusual physical effects which are far removed from the starting point:

Quote from: Sciama 1953
If the rest of the universe determines the inertial frames, it follows that inertia is not an intrinsic property of matter, but arises as a result of the interaction of matter with the rest of the matter in the universe.

Unless Rodal accedes to my demand to start from this point and derive Woodward's Equation #3 for the community, I shall not buy him a Scotch this Friday after work.  My decision is final.  Plus, I double dog dare him.
Title: Re: EM Drive Developments
Post by: Rodal on 09/25/2014 04:43 pm
The word "supposedly" used regarding Woodward's formulation.   (First I heard it used in Woodward's response to a question from the audience on how can the effect be one of instantaneous action at a distance. (
[ http://www.youtube.com/watch?v=hn8hqX9JBOE#t=2468 ]
where I have on purpose timed it to when the question is asked, otherwise advance to the end of the presentation at 41:08 minutes (2468 sec)))

When it is stated that  " "the Mach effect" is supposedly being accessed indirectly by dynamic manipulation of materials"

What is meant by "supposedly"? 

is it:

A) a presumption that the justification is true absent conclusive evidence to the contrary
B) a presumption of what is assumed or believed by others
C) a warning that the person stating it is unsure and/or has reasons to doubt the justification
D) another meaning
Title: Re: EM Drive Developments
Post by: Rodal on 09/25/2014 07:34 pm
In 2009 and 2010, Brito, Marini and Galian published a noteworthy experiment with negative results regarding Woodward's theory and a particular design of EM thrusters.  Brito et. al.'s experiment had the ability to discriminate between thrusts in the uN (microNewton) range while the predicted Woodward thrust was 3.4 mN (milliNewton), orders of magnitude larger, yet the results showed no measurable thrust.   These are the experimental reports:



2009, Hector H. Brito, Ricardo Marini and Eugenio S. Galian, "Null Findings on Electromagnetic Inertia Thruster Experiments using a Torsion Pendulum" 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 2 - 5 August 2009, Denver, Colorado
http://enu.kz/repository/2009/AIAA-2009-5070.pdf

2010, Ricardo L. Marini; Eugenio S. Galian , "Torsion Pendulum Investigation of Electromagnetic Inertia Manipulation Thrusting"  Journal of Propulsion and Power, Vol. 26, No. 6 (2010), pp. 1283-1290
http://arc.aiaa.org/doi/abs/10.2514/1.46541?journalCode=jpp



Quoting from their report:

<<The thruster, is a self-contained unit including the propulsion modules and a battery operated 600W/1MHz power processing unit (PPU). Each module comprises a 30 turns toroidal coil wrapped around a ceramic housing containing a 10 nF - 8 mm wide annular capacitor with BaTiO3 ceramic dielectric (epsilonr ~ 4400). The capacitor-coil assembly is wired as a tank circuit and mounted in a common acrylic housing filled with a Phase Change Material (PCM), for limited thermal control of the assembly. The modules are wired in parallel to a common supply of 350 V- AC @ 1 MHz>>

<<For direct assessment of propulsive forces, a Cavendish-Coulomb method of detection based on a very sensitive single fiber torsion pendulum was implemented, together with a Kelvin laser measurement technique (see Fig. 4). ... The test unit being a self-contained one, spurious effects like inner motions, selfelectromagnetic couplings, piezoelectric, electro/magnetostriction, and thermal shifts of center of mass, are deemed to have a negligible influence on the setup dynamics. The thruster and its counterweight are fixed to a hollow cylindrical bar 0.4-m length, the whole fixture vertically suspended by a steel wire 0.8-mm dia., 2.45-m length. The suspension point was located 0.22 m from the thruster center of mass, and 0.15 m from the counterweight attachment point. The suspended fixture had a moment of inertia with respect to the wire axis of 0.937 kg-m2, and a free oscillation period of 168 s. A laser beam is reflected by a mirror fixed to the suspension wire onto a screen located 5.02 m from the suspension. The successive peak locations of the laser dot are marked on the screen following visual recording of the dot, thus performing a Kelvin laser measurement technique.>>

<<After conducting setup dynamics simulations involving varied initial conditions as well as activation times (t2 – t1), the setup was found to be able of discriminating thrusts in the N (microNewton) range, when the forces were applied according to the above mentioned procedure. However, under activation of the RAMA-II thruster in non-modulated power mode, no propulsive effect above that sensitivity range was observed, as shown in Table 1 where three successive peak locations are presented for each test, with the thruster activation occurring between peaks #2 and #3. In all tests two propulsive modules of four were activated to avoid PPU overheating and the measured supply voltage was 280 V, which yields an expected thrust around 320 mN, according to Eq. (1). Lower than nominal PPU output voltages were reported as related to poor current delivery capabilities of the employed lead-acid batteries, and built in current and temperature limitations to avoid propulsion modules and PPU overheating.>>

<<The observed negative results for [Brito's EM drive] activation in non-modulated power mode, imply that the following theoretical approaches are wholly or partially falsified:  Transient mass fluctuation, Thrust predicted according to Woodward’s formulation is around 3.4 mN, thus according to the results reported here no Mach induced mass fluctuation is taking place up to the sensitivity of the experimental apparatus.>>
Title: Re: EM Drive Developments
Post by: Rodal on 09/25/2014 07:37 pm
From Brito et.al.'s report, here is their table of results, and pictures of their setup
Title: Re: EM Drive Developments
Post by: Rodal on 09/25/2014 07:43 pm
It is noteworthy that Brito et.al. used  (for the experiments that showed no measurable thrust) the Cavendish hanging pendulum type that I have been advocating should be superior to the inverted pendulum apparatus used by NASA Eagleworks. 

Observe, from the picture above, how simple is their setup for the Cavendish hanging pendulum damped by an oil bath compared to the NASA Eagleworks torsional inverted pendulum with magnetic dampening.

The Cavendish type of hanging pendulum is the setup that was used to perform the classical experiments to measure the inverse square law of gravitation as well as the Casimir force.  Also observe that they used a simple oil bath as the damping device instead of the magnetic damping being used at NASA Eagleworks. 

NASA Eagleworks reported that John Hopkins has a Cavendish type of pendulum that they were interested in using to verify the NASA Eagleworks experiments, I think that this should be much preferred rather than having to verify the NASA Eagleworks test with further tests using inverted torsional pendulums at JPL or NASA Glenn.

Also the test unit was a very compact self-contained setup with the whole unit together (including the power source), and they took care of a design to eliminate spurious effects like inner motions, selfelectromagnetic couplings, piezoelectric, electro/magnetostriction, and thermal shifts of center of mass.
Title: Re: EM Drive Developments
Post by: Rodal on 09/25/2014 07:47 pm
It is also noteworthy that Brito et.al. found anomalous thrust measurements when their same EM drive was placed in an inverted pendulum:

<< a flex pendulum thrust stand using a high sensitivity piezoceramic strain transducer (PST). The experimental setup basically consists of mounting the thruster as a seismic mass atop a thin vertical cantilever beam, sitting on a vibration-free platform in a vibration isolated working place, as shown in Fig. 2. By using sine modulation of the supply (“carrier”) AC voltage, a modulated average thrust is theoretically achieved, at the modulation and twice the modulation frequencies, with amplitudes 1/2 and 1/8, respectively, of the non-modulated average thrust. By detecting this alternate force, the geomagnetic influence becomes averaged out; direct detection in frequency domain also permits to get rid of numerical artifacts>>

however <<the predicted mechanical effects are several orders of magnitude below those reported [with the inverted pendulum] here>>

They conclude with the statement <<Intensive testing is planned to assess the influence of potentially spurious effects, and to establish the dependence of the [inverted] flex pendulum amplitudes on the modulation frequency in order to identify the force producing mechanism as related to electrical quantities>>

The fact that their classical Cavendish type hanging pendulum found no measurable thrust (orders of magnitude below the predictions), while their inverted pendulum showed measurable thrust several orders of magnitude above the predictions shows the spurious nature of EM drive thrusts measured by the inverted pendulum.
Title: Re: EM Drive Developments
Post by: Rodal on 09/25/2014 07:58 pm
Furthermore it is noteworthy that H.H.Brito had a career publishing reports claiming experimental measurements of propellant-less EM Drives prior to the above mentioned results:

1998 " A propulsion–mass tensor coupling in relativistic rocket motion"
http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.54960

1999 "Propellantless Propulsion by Electromagnetic Inertia Manipulation: Theory and Experiment"  http://www.intalek.com/Index/Projects/Research/0994.pdf
http://www.ovaltech.ca/pdfss/ElecMagInertia.pdf

2001/2004 "Experimental status of thrusting by electromagnetic inertia manipulation"
http://www.sciencedirect.com/science/article/pii/S009457650300225X

2003 " Direct Experimental Evidence of Electromagnetic Inertia Manipulation Thrusting"
http://arc.aiaa.org/doi/abs/10.2514/6.2003-4989

2005 "Overview of Theories and Experiments on Electromagnetic Inertia Manipulation Propulsion"
http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.1867270

2007 "Direct Experimental Evidence of Electromagnetic Inertia Manipulation Thrusting", Journal of Propulsion and Power, Vol. 23, No. 2 (2007), pp. 487-494
http://arc.aiaa.org/doi/abs/10.2514/1.18897?journalCode=jpp
Title: Re: EM Drive Developments
Post by: Rodal on 09/25/2014 08:00 pm
As I wrote previously, the practical problem with independent verification (at John Hopkins -using their Cavendish type hanging pendulum- or other universities) is that the scientific community has dismissed the NASA propellant-less tests (either vocally as done by John Baez and Sean Carroll, or quietly as done by most other academics in Aerospace Engineering -and quietly dismissing these results at other NASA propulsion centers-).  The academic community -particularly nowadays- knows that it is not considered to be an advancement to their career to produce independent experimental data that nullifies esoteric claims (claims that run contrary to conservation of momentum and known physics) that the rest of the community will meet with "I could have told you that".  So academics at MIT, Stanford, CalTech, etc., are negatively motivated, they actually have a disincentive  to spend their time and effort to examine these exotic claims. 

Actually Woodward's effect has been lampooned in a 2006 news comic strip, see:  http://angryflower.com/experi.html

And xkcd has lampooned the Quantum Vacuum explanation for the anomalous thrust measurements at NASA Eagleworks:  http://www.explainxkcd.com/wiki/index.php/1404:_Quantum_Vacuum_Virtual_Plasma


So, it is very noteworthy that H.H.Brito and his colleagues published experimental results that nullified his previous experimental work, showing with a Cavendish-type balance no measurable thrust for the propellant-less EM drive.  It is an outstanding demonstration of scientific honesty for Prof. Brito to have published these experimental results that nullify more than a decade of his previous efforts in propellant-less EM drives.

It is unusual to find people that had been measuring for more than a decade an esoteric effect to later produce experimental data that nullifies the very effect they were championing.
Title: Re: EM Drive Developments
Post by: Rodal on 09/26/2014 01:53 am
The subsequent 2010 AIAA Journal of Propulsion and Power paper by Milani and Galian

2010, Ricardo L. Marini; Eugenio S. Galian , "Torsion Pendulum Investigation of Electromagnetic Inertia Manipulation Thrusting"  Journal of Propulsion and Power, Vol. 26, No. 6 (2010), pp. 1283-1290
http://arc.aiaa.org/doi/abs/10.2514/1.46541?journalCode=jpp

states this in even stronger terms:

<<The new results conclusively show that the devices tested do not produce the thrusts predicted by the theory, or those supposedly obtained before with the flexion [inverted] pendulum, not even up to 2 orders of magnitude lower. This strongly suggests that the positive results obtained with the flexion [inverted] pendulum would have been produced by spurious effects, very likely forces caused by electromagnetic interaction among some components of the electric circuit, which were not appropriately estimated.>>
Title: Re: EM Drive Developments
Post by: cuddihy on 09/26/2014 02:09 am
Woodward's theory (in his book) on the "propellantless" propulsion claims it needs both simultaneuously the EM flux (delta E) and the changing acceleration of the mass (delta a). In Brito's experiment I see where the Delta E is coming from but what is providing the delta a?

Or was this an unjustified modification to his theory Woodward proposed after Brito's nullification experiment?

Title: Re: EM Drive Developments
Post by: Rodal on 09/26/2014 02:37 am
Woodward's theory (in his book) on the "propellantless" propulsion claims it needs both simultaneuously the EM flux (delta E) and the changing acceleration of the mass (delta a). In Brito's experiment I see where the Delta E is coming from but what is providing the delta a?

Or was this an unjustified modification to his theory Woodward proposed after Brito's nullification experiment?

Fearn  and Woodward make that statement in their recent paper (2013)  "Experimental Null Test of a Mach Effect Thruster. Heidi Fearn and James F. Woodward" http://arxiv.org/ftp/arxiv/papers/1301/1301.6178.pdf.
They state, prominently in Italics, the following:

<<Note that the mass fluctuation predicted here only occurs in an object that is being accelerated as the power fluctuates. If no “bulk” acceleration of the object takes place, there is no mass fluctuation.>>

<<Note too that simply charging and discharging capacitors will not produce mass fluctuations. They must at the same time be subjected to large “bulk” accelerations>>

* When did such statements first appear in Woodward's publications?

* What magnitude acceleration is a large “bulk” acceleration according to Woodward?
Title: Re: EM Drive Developments
Post by: cuddihy on 09/26/2014 02:41 am
I've been loosely following Woodward posts here in since 2009, but the first time I saw that claim was 2011 on the talk-polywell forum.

To add--I'm not clear on the theoretical basis for it, only a claimed experimental one.

Second add--I can't find the thread but 2011-ish here or on Talk-polywell either Paul March or GIThruster said  March's "MLT" experiments didn't have bulk acceleration either, so would have been invalid. Perhaps that's why they weren't tested on the Eagleworks balance.

I also have to add that whatever inertial force basis Woodward claims, it can't be gravity as we experience it every day and experimentally. You actually have to posit a new gravity-like attractive condition intrinsic to the structure of spacetime that is not "gravity", because of the specific time-travelling (or Wheeler-Feynman radiation reaction that Woodward prefers but is actually inaccurate) inertial reactions. Whatever it would be, it aint gravity.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/26/2014 08:42 am
<<The observed negative results for [Brito's EM drive] activation in non-modulated power mode, imply that the following theoretical approaches are wholly or partially falsified:  Transient mass fluctuation, Thrust predicted according to Woodward’s formulation is around 3.4 mN, thus according to the results reported here no Mach induced mass fluctuation is taking place up to the sensitivity of the experimental apparatus.>>

This is the kind of disappointing outcome that I was expecting.

Does Stardrive, or anyone else working with these devices have a rebuttal, or does the "thrust" only manifest on overly complicated, magnetically dampened, inverted torsion pendulums?
Title: Re: EM Drive Developments
Post by: cuddihy on 09/26/2014 11:34 am
Rotosequence, see the above. Woodward's claim is that the Brito experiment (and some others) don't disprove the effect because they're missing the "changing acceleration of the bulk mass".

I.e. The claim is that the Brito experiment only tests half the necessary conditions for the effect to be observed.
Title: Re: EM Drive Developments
Post by: Rodal on 09/26/2014 12:26 pm
*****EDIT
Some people have found the wording here to be offensive.  My apologies.  My intention was never to accuse anybody, I was only trying to understand this issue.  An explanation has been given concerning the "MLT" type of thruster and I have since then, further understood that the "MLT" experiments in slide 40 of Dr. White were not performed at NASA.

I very much appreciate everyone else's opinion on EM Drive Developments.

October 1, 2014
****

Do people get a sense of a moving goal post ? . 

When experiments do not show the predicted effect, multiplicative fudge factors ranging from 0 to 1, such that for a value of zero there is no Woodward effect, are proposed by Buldrini.  No estimation is presented of what the value of the fudge factors should be. 

Now a new condition is added that the effect won't manifest itself unless the drive is simultaneously accelerated by external power.    When did this condition first appear in Woodward's publications?
What magnitude of “bulk” acceleration is large enough  according to Woodward?

It is elucidating that we get now a recognition by Woodward that:

<<simply charging and discharging capacitors will not produce mass fluctuations. >>

This effectively recognizes that solely replacing fluctuations in the rest energy by the fluctuations in the electric power input to a capacitor is not just "overly optimistic" but invalid.  See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260795#msg1260795  He now adds the extra condition that the device needs to be simultaneously accelerated to an unspecified large enough “bulk” acceleration.  The new experimental setup used by Woodward involves the linear (in voltage) piezoelectric effect and the quadratic (in voltage) electrostrictive effect in a stack of PZT disc capacitors.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/26/2014 01:17 pm
http://arxiv.org/ftp/arxiv/papers/1301/1301.6178.pdf.

This paper describes a PZT mechanism which has nothing whatsoever to do with the experimental apparatus described above.

Quote from: Fearn, Woodward 2013
The theory of the Mach effect thruster (MET) has been written in great detail elsewhere...

I've written a lot about the USG HSF policies and funding priorities elsewhere.  While I'm certain that I make a correct assessment of these issues, having written about these issues elsewhere doesn't validate my assessment.

So too, that the ever changing M-E theory has been written about elsewhere proves nothing about its validity.  There are flaws in the assumptions about the earlier theories which have been previously posted on this thread.  The flaws are mathematical and procedural, particularly in the experimental apparatus.

Quote from: Fearn, Woodward 2013
[1] H. Fearn & J. F. Woodward, “Recent Results of an Investigation of Mach Effects Thrusters”, Joint Propulsion Conference 2012 to be published in American Institute of Aeronautics and Astronautics.

[2] J. F. Woodward “Making Starships and Stargates” Springer 2013.

They quote their own work, which is not a substitute for peer review.

Quote from: Fearn, Woodward 2013
Evidently, the simplest Mach effect depends on the square of the acceleration of the body in which it is produced.

Evidently, equations model reality and do not cause reality.

Quote from: Fearn, Woodward 2013
To start with, we wish to show that the stack (called N4) is capable of producing a linear thrust. The production of thrust depends on combining a periodic force on an object undergoing periodic mass fluctuations at the frequency of the fluctuations. You also require the appropriate phase so that the force on  the object in one part of each cycle is different from that in another part of the cycle.

Ok.

Quote from: Fearn, Woodward 2013
(We should really multiply by a factor of 4 pi to allow for SI units but as you will see this will still lead to an underestimate.)

We should?  I thought they were using SI units!

Quote from: Fearn, Woodward 2013
Steiner-Martins give 3.2 x10-10 mV-1 for the “d33” piezoelectric constant for the SM-111 material. That is the value of Kp. They list no value for the electrostrictive constant. But electrostrictive effects are generally smaller than piezoelectric effects [3-5]. Using the value for Kp we find

|F|= 191.4 K sub e (12)

(I used the pipe character because of HTML character conflict)

From the power spectrum we can estimate that the electrostrictive constant must be somewhere between 1/6th and 1/10th of the piezoelectric constant. If we take the electrostrictive constant to be 1/8th of the piezoelectric constant, or approximately 4 x 10-11 mV-2, we find that a thrust on the order of 8 nN is predicted. We should in fact multiply by 4π to allow for the SI units, but the observed thrust for these parameters is a couple of microNewtons.

IOW, they don't know what the electrostrictive constant is, so they assume a value, which they then don't convert to SI units, and lo, a predicted thrust is suggested.

Quote from: Fearn, Woodward 2013
... the condition that the capacitor restmass vary in time is met as the ions in the lattice are accelerated by the changing external electric field.

The rest mass fluctutions that may occur cannot be measured with the power levels applied to the equipment illustrated. Period.

Quote from: Fearn, Woodward 2013
Some of this energy is likely stored in the gravitational field...

And the rest is "likely" stored in a compressed hummoingbird wing composite?   It is not a "reasonable" place to start.  It appears to me that there is an alchemical faith in pentagrams being expressed here.  That is, here is an equation that we have made. Let us then build a transformative mechanism which will produce the effect that the equation predicts.

Quote from: Fearn, Woodward 2013
The power amplifier employed was a Carvin DCM 1000 operating in bridged mode.

If I operate my Mac 275 in bridged mode, I can use it to operate a shaker table.  Which fluctuates mass.  In bulk.  There's not enough power in their experimental setup to detect rest mass fluctuations.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/26/2014 01:26 pm
http://forum.nasaspaceflight.com/index.php?topic=35706.msg1262675#msg1262675

Solo dicendo.
Title: Re: EM Drive Developments
Post by: JasonAW3 on 09/26/2014 02:09 pm
Take a look at my subsequent comment:

<<But, if electrons are emitted by field emission from a dielectric-resonator experiencing breakdown under the electric field, what happens to the electrons in the air?  Is the air also ionized by the electric field?  How could that generate propulsion, unless we have a leaky microwave cavity ?>>

These are my malformed , incomplete, thoughts in "poking around" looking for different explanations of the measurements. 

If the propulsion is the result of ionized air leaking from the cavity, I see this as much less effective than present ion rockets.  Also take into account that they tested thrust pulses for only ~30 sec duration and that would not get us anywhere.  A cracked dielectric resonator emitting electrons and/or ionization of air won't work long enough or effectively enough...

Also as far as specific force, the results from the Cannae and Frustum testing were not too encouraging.  The Boeing/DARPA specific force tests show an impulse instead of a rectangular pulse.  The trips to the moons of Saturn and Jupiter are predicated on very optimistic extrapolations...

Problem is, I thought that they'd also tested it in a vacume chamber as well and still got positive results.

       I may be a bit confused on this one as it seems that I've heard both that they WERE going to test it in a Vacume Chamber and that they HAD tested it in a vacume chamber.

       If they haven't yet tested it in a vacume, then your "Ion Wind" theory is possible, but if they have, again, some other mechanism must be at work.

       Could someone clear this one up for me, have they or haven't they tested in a vacume chamber and if not, why?  It shouldn't be too hard to set up and experiment like this in a vacume chamber.  (I do remember some discussion about vacume resistant capacitors, but that should have been corrected by now).
Title: Re: EM Drive Developments
Post by: Rodal on 09/26/2014 02:23 pm
Take a look at my subsequent comment:

<<But, if electrons are emitted by field emission from a dielectric-resonator experiencing breakdown under the electric field, what happens to the electrons in the air?  Is the air also ionized by the electric field?  How could that generate propulsion, unless we have a leaky microwave cavity ?>>

These are my malformed , incomplete, thoughts in "poking around" looking for different explanations of the measurements. 

If the propulsion is the result of ionized air leaking from the cavity, I see this as much less effective than present ion rockets.  Also take into account that they tested thrust pulses for only ~30 sec duration and that would not get us anywhere.  A cracked dielectric resonator emitting electrons and/or ionization of air won't work long enough or effectively enough...

Also as far as specific force, the results from the Cannae and Frustum testing were not too encouraging.  The Boeing/DARPA specific force tests show an impulse instead of a rectangular pulse.  The trips to the moons of Saturn and Jupiter are predicated on very optimistic extrapolations...

Problem is, I thought that they'd also tested it in a vacume chamber as well and still got positive results.

       I may be a bit confused on this one as it seems that I've heard both that they WERE going to test it in a Vacume Chamber and that they HAD tested it in a vacume chamber.

       If they haven't yet tested it in a vacume, then your "Ion Wind" theory is possible, but if they have, again, some other mechanism must be at work.

       Could someone clear this one up for me, have they or haven't they tested in a vacume chamber and if not, why?  It shouldn't be too hard to set up and experiment like this in a vacume chamber.  (I do remember some discussion about vacume resistant capacitors, but that should have been corrected by now).

The (Cannae and Frustum microwave) devices tested in the last NASA Eagleworks report "Anomalous thrust ..." were not tested in a vacuum chamber, because they realized, late in the latest round of Eagleworks testing, that their electrolytic capacitors were not rated for vacuum conditions.  See the last page of the report:

<<Vacuum compatible RF amplifiers with power ranges of up to 125 watts will allow testing at vacuum conditions which was not possible using our current RF amplifiers due to the presence of electrolytic capacitors. >>

The Boeing/DARPA device (of which practically nothing has been disclosed concerning its internal workings) was reportedly tested in a vacuum chamber.  However, the Boeing/DARPA thrust was an impulse, not a rectangular pulse, hence it is questionable as to how and whether the Boeing/DARPA device could be used for sustained thrusting, under the assumption that the Boeing/DARPA device results are not an artifact of the inverted pendulum with magnetic dampening testing at NASA Eagleworks.  The shape (and unreproducible behavior of one the impulses) of the response could very well be a testing artifact (see below).

Based on everything up to this point, my opinion is that all the inverted pendulum results, including those at NASA Eagleworks, are to be suspected as artifacts due to A) the instability of the inverted pendulum resulting in chaotic motion and B) the magnetic dampening which results in limit cycles.  I will explain this further as I get the time to do so.

Title: Re: EM Drive Developments
Post by: Rodal on 09/26/2014 02:34 pm
The problem with a lot of this testing (except for the classical Cavendish type of hanging pendulum -which is known from the classical gravitation and Casimir force measurements- also used by Brito, Marini and Galian to nullify previous results) is that an inadequate analysis of the testing device (i.e. inverted pendulum) testing is presented. 

No analysis of mode coupling, no analysis of self-excitation, no analysis of parasitic modes, no analysis of nonlinear dampening is presented.  Both mechanical and electromagnetic coupling and self-excitation are not analyzed. 

It is evident from the NASA Eagleworks results that the magnetic dampening plays a very important role in their results (admittedly affecting the baseline), yet there is no closed-form or numerical analysis of its interaction, or an attempt to assess it experimentally by trying other forms of dampening.  Also recall that at the MIT Aero and Astro department the inverted pendulum devices designed by Prof. Martinez-Sanchez for testing ion thrusters, has been designed such that the tested thruster remains horizontal at all times.  This is needed in order to eliminate coupling between swinging and torsional modes and self-excitation.

NASA Eagleworks stated that

<<The Johns Hopkins University Applied Physics Laboratory has also expressed an interest in performing a Cavendish Balance style test>>

This would be the most effective way to proceed.

Even if (as I suspect) there is no big enough vacuum chamber available/affordable to perform a Cavendish type of test in a vacuum, it is is much more important (in my opinion) at this point to perform a Cavendish type of test -even at room conditions- than testing in a vacuum again with an inverted pendulum using magnetic dampening.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/26/2014 04:38 pm
reply from GiThruster regarding Brito's experiments posted by Dr Rodal

Quote
Yes well, you'll have to forgive me that I can't read all what Dr. Rodal is posting. It's pretty obvious he is not familiar with the work. Neither was Brito when he decided to do an M-E experiment using a discarded design a year or two after it had been abandoned.

Quote from: Rodal
* When did such statements first appear in Woodward's publications?

* What magnitude acceleration is a large “bulk” acceleration according to Woodward?

This is almost asking the right question. It is not the magnitude of the bulk that qualifies it as "bulk" but rather, it is accelerating both ends of the electromechanical spring found in bulk matter. The MLT design used by Brito in the above only accelerated the mobile ion inside the BaTiO3 dielectric cage or lattice. What needs to happen is one accelerates the entire lattice because this includes then, both ends of these EM springs. Accelerating only the mobile ion does not accelerate the entire spring.

Nembo Buldrini's "bulk acceleration conjecture" that corrected the efforts in M-E research was back in early 2008 I believe. It was certainly before Brito's experiments. And again, this is why it is so foolish to do replications or validations of anyone's work without availing oneself to the current state of the art. (And really one hopes people wanting to criticize such work ought to be cognizant of the facts as well.)

I was actually the first to argue that as far as I understood the theory, not just the mobile ion needed to be accelerated, but the entire lattice. Nembo Buldrini then showed this is true from the math and all of the M-E work immediately changed. I was the first to abandon the Mach Lorentz Thruster (the design Brito used) and focus on the previous design, what is now known as the Mach Effect Thruster or MET.

There are two very important aspects to the Bulk Acceleration Conjecture. First is, since the entire active mass material lattice needs to move, it can't be sintered with compounds intended to repress electromechanical responses the way the MLT caps used were, and I presume the caps used by Brito. The lattice needs to accelerate and the magnitude of this acceleration determines both the magnitude of the Mach Effect generated (by the 1w acceleration) and the mass fluctuation rectification into force (by the 2w acceleration). So what it turns out is, the thrust generated from these 1/4 wave oscillator/resonators is quadratic with mechanical Q, and Brito's design had no Q to speak of. It was not a 1/4 wave resonator. If you don't use a reaction mass or acoustic mirror in your design, even given the shabby acceleration generated by ceramics sintered to repress piezo-action and electrostriction, you get 1/2 wave mechanical action which means acceleration in two opposite directions which then cancel each other as regards force generated.

So long story short is, the design used by Brito had been abandoned a year or two before he did his experiment for good reasons and ought not have worked according to theory. This has all been explained by me in several forums over the years, and if Dr. Rodal thinks he is qualified to remark about "moving the goalposts" or whatever, I would just suggest to him he do his homework first. He could for example read Jim's book.

Title: Re: EM Drive Developments
Post by: Rodal on 09/26/2014 04:49 pm
reply from GiThruster regarding Brito's experiments posted by Dr Rodal
...He could for example read Jim's book.

 GiThruster writes <<When did such statements first appear in Woodward's publications?...This is almost asking the right question...He could for example read Jim's book>>

Sorry, I need some translation  :)

So I continue to ask these questions (@cuddihy gave his answer << the first time I saw that claim was 2011 on the talk-polywell forum.>>, perhaps others can also shed some light):

Is the answer by GiThruster to the question

<<When did such statements

[
<<Note that the mass fluctuation predicted here only occurs in an object that is being accelerated as the               power fluctuates. If no “bulk” acceleration of the object takes place, there is no mass fluctuation.>>
<<Note too that simply charging and discharging capacitors will not produce mass fluctuations. They must at the same time be subjected to large “bulk” accelerations>>
]

 first appear in Woodward's publications?>>

that the first time that GiThruster sees this appear in Woodward's publication is in Woodward's book published in December 14, 2012?  Or is he saying that I should read his book to find out the answer to that question?

Why is it that I have to read a book published much later, in Dec 2012, to find out whether he wrote about this prior to Brito's August 2009 report?:

Publisher: Springer; 2013 edition (December 14, 2012)
ISBN-13: 978-1461456223

years after Brito, Milani Galiani's 2009 presentation ?:

2009, Hector H. Brito, Ricardo Marini and Eugenio S. Galian, "Null Findings on Electromagnetic Inertia Thruster Experiments using a Torsion Pendulum" 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 2 - 5 August 2009, Denver, Colorado
http://enu.kz/repository/2009/AIAA-2009-5070.pdf


When GiThruster writes  <<I was actually the first to argue that as far as I understood the theory, not just the mobile ion needed to be accelerated, but the entire lattice.>>  ?

Is GiThruster claiming that he argued this before Prof. Woodward ? Or is GiThruster claiming to be the first to argue this in the forum?

When GiThruster writes <<the design used by Brito had been abandoned a year or two before he did his experiment for good reasons and ought not have worked according to theory. This has all been explained by me in several forums over the years>> is GiThruster saying that it had been abandoned by Brito or by Woodward "a year or two before Brito's experiment" ?

If the answer is the later, then it appears that GiThruster is saying that Woodward abandoned his initial (theoretical and experimental) notion that simply charging and discharging capacitors will produce mass fluctuations around 2008 ?
____________________________________

Again, it is some progress that they now recognize that:

<<simply charging and discharging capacitors will not produce mass fluctuations.>>
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/26/2014 05:59 pm
reply from GiThruster regarding Brito's experiments posted by Dr Rodal

Quote
... (0) It's pretty obvious [Rodal] is not familiar with the work.

Quote from: Rodal
* When did such statements first appear in Woodward's publications?

* What magnitude acceleration is a large “bulk” acceleration according to Woodward?

This is almost asking the right question. It is (1) not the magnitude of the bulk that qualifies it as "bulk" but rather, it is accelerating both ends of the electromechanical spring found in bulk matter. ...

There are two very important aspects to the (2) Bulk Acceleration Conjecture. ...

(3) So long story short is, ... [Rodal] could for example read Jim's book.

0. Seems to me that Rodal has at least a passing familiarity with the work.

1. I call el poopo del toro. 

Either mass is moving or else it is not.  There is no scientific definition of the term "bulk" which can be invoked.

2. I'll weigh myself before and after yoga this afternoon, and report on my bulk.

3. I too, have suggested that Rodal purchase and read the book.

AcesHigh is to be thanked for his relay services, but unfortunately, there is no substantive answer to Rodal's questions.
Title: Re: EM Drive Developments
Post by: Rodal on 09/26/2014 06:02 pm
I plead guilty as charged, concerning reading the "Making Starships and Stargates: The Science of Interstellar Transport and Absurdly Benign Wormholes " December 14, 2012 book.  I even had a very generous offer from one of the people in this forum to send me his/her book by mail.   I prefer to consider published papers, particularly those in peer-reviewed publications, rather than books, as books are not peer-reviewed and  contain more errors.  Book editors edit for style and grammar and not for scientific content.

However, I have read, and quoted, several of Woodwards's papers prior to and after publication of his book.

Therefore, what I wrote cannot be taken as a criticism of Woodward's "Starships and Stargates" book, only of the specific papers that I quoted.  The paper I have quoted most often is "FLUX CAPACITORS AND THE ORIGIN OF INERTIA", Foundations of Physics, October 2004, Volume 34, Issue 10, pp 1475-1514.  The latest paper I have quoted is "Experimental Null Test of a Mach Effect Thruster" by Heidi Fearn and James F. Woodward, arXiv:1301.6178 [physics.ins-det]

Title: Re: EM Drive Developments
Post by: Rodal on 09/26/2014 09:57 pm
GiThruster  wrote <<I was actually the first to argue that as far as I understood the theory, not just the mobile ion needed to be accelerated, but the entire lattice. Nembo Buldrini then showed this is true from the math and all of the M-E work immediately changed. I was the first to abandon the Mach Lorentz Thruster (the design Brito used) and focus on the previous design, what is now known as the Mach Effect Thruster or MET.>>

If my understanding is correct, GiThruster is referring to the experiments performed by Paul March, reported in this paper: Paul March and Andrew Palfreyman. "The Woodward Effect: Math Modeling and Continued Experimental Verifications at 2 to 4 MHz"  http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=31119.0;attach=496011, since Paul March refers to his experiments as Mach Lorentz Thruster:

<<This type of electromagnetic field thruster, or Mach-Lorentz Thruster (MLT), purports to create a transient mass differential that is expressed in a working medium to produce a net thrust in the dielectric material contained in several capacitors.>>

So, if I understand GiThruster correctly,  the experiments by Paul March quoted by Dr. White in his slide 40  (in August 2013)  of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf :

______________________________

Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2004:   


SPECIFIC FORCE=  0.4 N/kW   (up to 90 000 times larger than the photon rocket)

______________________________

Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2005: 


SPECIFIC FORCE=  0.3 N/kW  (up to 67 000 times larger than the photon rocket)

______________________________

have been deemed to be an experimental artifact? as GiThruster states that "they" [meaning Woodward ?] have abandoned this kind of thruster as not being able to produce thrust because the "bulk" is not accelerated?

because <<simply charging and discharging capacitors will not produce mass fluctuations.>>

My interpretation of all this is that GiThruster and Woodward think that the kind of MLT drive that Paul March tested in 2004/5 cannot generate sizeable thrust according to the latest interpretation (post 2008? and certainly post-Brito-2009-null experiment) of Woodward.  But since Dr. White presented these results of Paul March in his slide 40 (in August 2013) as a Q-thruster, Dr. White thinks that Paul March's MLT thruster can theoretically deliver thrust according to White's Quantum Vacuum theory.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/27/2014 01:40 am
This semantic web is too tangled for me to unravel. 

Summary for the proletariat:  The first theory didn't get experimental verification.  Neither did the second, nor the third.  Is the experimental apparatus and associated theory of the OP the fourth?
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 01:58 am
Furthermore, it appears that the initials SFE in "SFE Test Article at JSC" of Dr. White's slide 40  (August 2013)  presentation http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf may stand for "Serrano Field Effect" (using Google to search for this). 

This website http://jnaudin.free.fr/lifters/act/html/sfptv1.htm by by Jean-Louis Naudin at http://jnaudin.free.fr/  has further information on what (this "free," French, website) claims is this "SFE" effect, as well as this one:  http://www.mednat.org/new_scienza/antigravita'%201.pdf.

Also see  this March 2003 article "Force on an Asymmetric Capacitor", by Thomas B. Bahder and Chris Fazi", Army Research Laboratory, Adelphi, MD http://arxiv.org/ftp/physics/papers/0211/0211001.pdf

<<During the 1920s, Thomas Townsend Brown was experimenting with an x-ray tube known as a "Coolidge tube," which was invented in 1913 by the American physical chemist William D. Coolidge. Brown found that the Coolidge tube exhibited a net force (a thrust) when it was turned on. He believed that he had discovered a new principle of electromagnetism and gravity. Brown applied for a British patent on April 15, 1927, which was issued on November 15, 1928 as Patent No. 300,311, entitled, “Method of Producing Force or Motion.”>> http://www.sunrisepage.com/ufo/files/Brown,%20Thomas%20Townsend.%20British%20Patent%20300,311.pdf

<<We have presented a brief history of the Biefeld-Brown effect: a net force is observed on an asymmetric capacitor when a high voltage bias is applied. The physical mechanism responsible for this effect is unknown. In section 4, we have presented estimates of the force on the capacitor due to the effect of an ionic wind and due to charge drift between capacitor electrodes. The force due to ionic wind is at least three orders of magnitude too small. The force due to charge drift is plausible, however, the estimates are only scaling estimates, not a microscopic model.
In section 5, we have presented a detailed thermodynamic theory of the net force on a capacitor that is immersed in a nonlinear dielectric fluid, such as air in a high electric field. The main result for the net force on the capacitor is given in equation (33). The thermodynamic theory requires knowledge of the dielectric properties of the fluid surrounding the capacitor plates. It is not possible to estimate the various contributions to the force until we have detailed knowledge about the high-field dielectric properties of the fluid. More experimental and theoretical work is needed to gain an understanding of the Biefeld-Brown effect. As discussed, the most pressing question is whether the Biefeld-Brown effect occurs in vacuum. It seems that Brown may have tested the effect in vacuum, but not reported it (Appendix B). More recently, there is some preliminary work that tested the effect in vacuum, and claimed that there is some small effect—smaller than the force observed in air; see the second report cited in reference [2]. Further work must be done to understand the effect in detail. A set of experiments must be performed in vacuum, and at various gas pressures, to determine the force versus voltage and current. A careful study must be made of the force as a function of gas species and gas pressure. In order to test the thermodynamic theory presented here, the dielectric properties of the gas must be carefully measured. Obtaining such data will be a big step toward developing a theoretical explanation of the effect. On the theoretical side, a microscopic model of the capacitor (for a given geometry) must be constructed, taking into account the complex physics of ionization of air (or other gas) in the presence of high electric fields. Only by understanding the Biefeld-Brown effect in detail can its potential for applications be evaluated. >>

This is a 2008 Purdue report on the ionic wind:  http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1226&context=nanopub

The "SFE Test Article at JSC" is the EM Drive tested at NASA Eagleworks in 2013 which we have been referring to as the "Boeing/DARPA drive".
Title: Re: EM Drive Developments
Post by: cuddihy on 09/27/2014 02:45 am
Ok, John you've made way too many comments on the related threads here not to have at least followed the claimed story unless it's deliberate. The story is that  the 'bulk acceleration' conjecture doesn't impact Woodward's 'source of inertia' theories at all because it's a question of correct method for engineering a 'unidirectional force generator' from the theory, not demonstrating a yeah/nay experiment that 'suggests itself' directly from the maths. Woodward's theory and maths suppose a 'particle' or 'mass' as the object being pushed/pulled on. Translating that to an observable mass pushed or pulled on at observable scale is not simple.

1. Early experiments by Woodward and Mahood did not consider the "bulk" acceleration criterion and saw mixed results that were not clear enough either way to prove or disprove anything, with different devices showing different responses and lots of concerns about standard effects, and straight up disagreement with the original calculated scaling, but enough to sniff that there could be something there. This was of the first suggested "MET" device, not because they knew they would need that  construction but because from what I understand PZT stacks were easiest for Woodward to construct and the most obvious approach for a cheap setup.

2. Palfreyman, Buldrini, Woodward, March, and even I believe at one point John Kramer attempted various types of replications using different schemes, including other METs, a 'mach guitar', March's MLTs, and a 'rotator'. Again, mixed results that caused some folks to be satisfied the theory had been invalidated and others to  be satisfied there was something consistent there but something unknown in the application that made even the 'successful' tests not match expected scaling with power & frequency.

3.  At some point (and I thought it was much later, but GIThruster says 2008), a conjecture was made public that non-bulk 'ion' acceleration schemes like the MLT were poor analogues for the 'particle' or 'mass' in the derivations because as an 'inertial' effect, not a significant enough portion of the matter in a 'non-bulk' mass would be changing acceleration in synch enough to overcome the stationary portion's inertia. Whereas of the whole mass is moving, there's no doubt it's an analogue to the Woodward theory 'particle' or 'mass'.

Then, going back, woodward's early experiments of the MET type would happen to correctly meet this criteria.

Not saying any of that makes this smell legit. But that's the story as I understand it.
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 02:49 am
Thanks @cuddihy for the information.
Title: Re: EM Drive Developments
Post by: birchoff on 09/27/2014 04:57 am
GiThruster  wrote <<I was actually the first to argue that as far as I understood the theory, not just the mobile ion needed to be accelerated, but the entire lattice. Nembo Buldrini then showed this is true from the math and all of the M-E work immediately changed. I was the first to abandon the Mach Lorentz Thruster (the design Brito used) and focus on the previous design, what is now known as the Mach Effect Thruster or MET.>>

If my understanding is correct, GiThruster is referring to the experiments performed by Paul March, reported in this paper: Paul March and Andrew Palfreyman. "The Woodward Effect: Math Modeling and Continued Experimental Verifications at 2 to 4 MHz"  http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=31119.0;attach=496011, since Paul March refers to his experiments as Mach Lorentz Thruster:

<<This type of electromagnetic field thruster, or Mach-Lorentz Thruster (MLT), purports to create a transient mass differential that is expressed in a working medium to produce a net thrust in the dielectric material contained in several capacitors.>>

So, if I understand GiThruster correctly,  the experiments by Paul March quoted by Dr. White in his slide 40  (in August 2013)  of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf :

______________________________

Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2004:   


SPECIFIC FORCE=  0.4 N/kW   (up to 90 000 times larger than the photon rocket)

______________________________

Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2005: 


SPECIFIC FORCE=  0.3 N/kW  (up to 67 000 times larger than the photon rocket)  [/color]

______________________________

have been deemed to be an experimental artifact? as GiThruster states that "they" [meaning Woodward ?] have abandoned this kind of thruster as not being able to produce thrust because the "bulk" is not accelerated?

because <<simply charging and discharging capacitors will not produce mass fluctuations.>>

My interpretation of all this is that GiThruster and Woodward think that the kind of MLT drive that Paul March tested in 2004/5 cannot generate sizeable thrust according to the latest interpretation (post 2008? and certainly post-Brito-2009-null experiment) of Woodward.  But since Dr. White presented these results of Paul March in his slide 40 (in August 2013) as a Q-thruster, Dr. White thinks that Paul March's MLT thruster can theoretically deliver thrust according to White's Quantum Vacuum theory.

As someone who has read Jim's book. I would consider your analysis quoted above to be valid.

Part of the reason I believe GiThruster and others keep pushing you to read Jim's book is because without it you have zero context. Yes you can attempt to reconstruct that context by simply searching for all the papers including those referenced. But I would argue that you would be missing some detail. For example in the book you learn that Woodward started his experiments with what he calls a Mach Effect Thruster and eventually stopped that line of investigation after learning about Brito's initial work on advanced propulsion schemes, using a simple electrical circuit to generate thrust. Woodward refers to this as a Slepian circuit in the book (because according to Woodward in the book the idea originated in an article published by Joseph Slepian in 1940; this link, http://www.hep.princeton.edu/~mcdonald/examples/slepian.pdf (http://www.hep.princeton.edu/~mcdonald/examples/slepian.pdf), should lend some credibility to the claim).It is this Slepian circuit that was renamed to Mach Lorrentz Thruster. It would not be possible to know that from only looking at the papers because according to the book it doesn't look like his early lab work was actually published, though there are repeated references to a series of tests being recounted in "The Technical End of Mach's Principle"(cannot seem to quickly find a link to this material via google). Woodwards justification for this lack of publishing results from his earlier experiments come down to his in ability to get consistent results, so like a good experimentalist he didn't trust the results and moved on to working with the Mach Lorrentz Thursters.

After the variable results of attempts to generate thrust using the MLT's it looks like that line of investigation was dropped and Jim returned to the MET's he had originally abandoned to see if he could pin point the cause of the variability in his early experiments. as you can see from the following comment from the last few paragraphs of chapter 4 reproduced below.

 
Quote
Sooner or later we have to deal with the fact that the results of the various experimental efforts over the years were, to put it circumspectly, variable at best. In part, this can be attributed to things like variation in construction details, the quality of components, and the aging of materials operated toward their electrical and mechanical limits. But something more fundamental seems to have been going on.

The person who put his finger on that more fundamental issue was Nembo Buldrini. What he pointed out was that given the way the transient terms of the Mach effect equation are written — in terms of the time-derivatives of the proper energy density — it is easy to lose
sight of the requirement in the derivation that the object in which the mass fluctuations occur must be accelerating at the same time. In some of the experimental cases, no provision for such a "bulk" acceleration was made. As an example, the capacitors affixed to the tines of the tuning fork in the Cramer and students' experiment made no provision for such an acceleration. Had the tuning fork been separately excited and the electric field applied to the capacitor(s) been properly phased, an effect might have been seen. But to simply apply a voltage to the capacitors and then look for a response in the tuning fork should not have been expected to produce a compelling result.

Other examples could be cited and discussed. Suffice it to say, though, that after Nembo focused attention on the issue of bulk accelerations in the production of Mach effects, the design and execution of experiments changed. The transition to that work, and recent results of experiments presently in progress, are addressed in the next chapter.


The emphasis above is strictly my own. The definition of  bulk acceleration was also defined at the end of chapter 4 as a foot note. I have reproduced it below, again emphasis is entirely mine

Quote
By "bulk" acceleration we are referring to the fact that the conditions of the derivation include that the object be both accelerated and experience internal energy changes. The acceleration of ions in the material of a capacitor, for example, does not meet this condition. The capacitor as a whole must be accelerated in bulk while it is being polarized.


Now while I can understand your reluctance to read Dr. Woodwards book. I think this is one particular instance that you should make an exception. The book is basically a summary of all of Dr. Woodwards work up to 2011-2012, which was written for easy digestion by an engineer. That said he also included references to all the published materials he references in his discussion of any theory and published experimental results.
Title: Re: EM Drive Developments
Post by: CW on 09/27/2014 06:33 am
About electrolytic capacitors not rated for vacuum conditions.. I think that's a silly excuse to avoid testing in vacuum. There is a number of ways to encapsulate electronic parts, e.g. using simple hot glue or other substances that can encapsulate for a long enough time during the experiments. I just can't believe this. Maybe hot glue was not fancy or Star Trek enough. It has to be special hardware ::) .
Title: Re: EM Drive Developments
Post by: Cinder on 09/27/2014 12:16 pm
Why not simply join the mailing list?  I see no benefit from these intermediates.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/27/2014 01:48 pm
Why not simply join the mailing list?  I see no benefit from these intermediates.

I found the mailing list to be a "reply all" fanclub only, and not worth the effort.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/27/2014 01:49 pm
Ok, John you've made way too many comments on the related threads here not to have at least followed the claimed story unless it's deliberate. The story is that  the 'bulk acceleration' conjecture doesn't impact Woodward's 'source of inertia' theories at all because it's a question of correct method for engineering a 'unidirectional force generator' from the theory, not demonstrating a yeah/nay experiment that 'suggests itself' directly from the maths. ...

Not saying any of that makes this smell legit. But that's the story as I understand it.

Cuddihy:  I appreciate your efforts here and there to explain some of these matters to me.  I do "follow" the argument, within my math and physics limits.

Please define the terms "bulk" and "non-bulk".  With numbers.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/27/2014 01:53 pm
Please define the terms "bulk" and "non-bulk".  With numbers.

As someone who has read Jim's book. I would consider your analysis quoted above to be valid. ...

Quote from: Woodward, the Stargate book
By "bulk" acceleration we are referring to the fact that the conditions of the derivation include that the object be both accelerated and experience internal energy changes. The acceleration of ions in the material of a capacitor, for example, does not meet this condition. The capacitor as a whole must be accelerated in bulk while it is being polarized.

This is not sufficient.

The experimental object is not accelerating and the internal energy changes are not measurably affecting the object's rest mass.

Quote from: Birchoff
Now while I can understand [Rodal's] reluctance to read Dr. Woodwards book. I think this is one particular instance that you should make an exception.

I agree.
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 02:03 pm
My interest has been, and remains, in what is responsible for the EM drive measurements performed and reported by Dr. White at NASA Eagleworks.

I discussed Woodward's explanations because of the experiments by Paul March quoted by Dr. White in his slide 40  (in August 2013)  of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf :

______________________________

Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2004:   


SPECIFIC FORCE=  0.4 N/kW   (up to 90 000 times larger than the photon rocket)

______________________________

Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2005: 


SPECIFIC FORCE=  0.3 N/kW  (up to 67 000 times larger than the photon rocket)

______________________________

It has now become apparent that:

1) These experiments were not performed at NASA Eagleworks

2) Woodward's explanation for this kind of EM Drive (sometimes called MLT thruster) has been nullified by the experiments conducted by Brito, Marini and Galian, which, among other things, show the importance of the testing device: the superiority of the classical oil-damped Cavendish hanging-pendulum (previously used to verify the inverse-square law of Gravitation and Casimir force) for measuring very small forces.

3) As stated by GiThruster and others, Woodward and his colleagues have abandoned this kind of (MLT) thruster as not being able to produce thrust because <<the "bulk" is not accelerated>>, and Woodward now states that <<simply charging and discharging capacitors will not produce mass fluctuations.>>

4) No Woodward MET thruster measurement has been reported to have ever been performed at  NASA Eagleworks.

5) Although I have never seen an actual numerical value threshold given for what Woodward and his colleagues consider to be a high enough acceleration for in their own words <<the "bulk" to be accelerated>>, it appears from the context of publications that the drives (SFE Boeing/DARPA, Cannae and Frustum) tested by Dr. White at  NASA Eagleworks, did not meet the <<"bulk" accelerated>> requirement by Woodward and therefore cannot be explained by Woodward's theory as presently stated.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/27/2014 02:10 pm
It may be that there is other info in the book that would buttress the faulty theory to date.
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 02:51 pm
So, these are the only EM drives that have been reported as having been tested at NASA Eagleworks by Dr. White:

Experimental data obtained using Dr. White's NASA inverted torsion pendulum

______________________________

"Serrano Field Effect" Boeing/DARPA device:
(@aceshigh quotes P. March (in another forum) as stating that this SFE device was tested in a vacuum by NASA)

THRUST =   20 to 110 uN  impulse response (not a rectangular pulse)
SPECIFIC FORCE = 1 to 20 N/kW  (225 000 to 4.5 million times larger than a photon rocket)


______________________________

Cannae Testing:
(not tested in a vacuum by NASA)

THRUST =   40 uN  ~rectangular pulse (duration 30s to 40s)
SPECIFIC FORCE:  0.0014 N/kW (up to 300 times larger than a photon rocket)


______________________________

Tapered (Frustum) Cavity Testing: 
(not tested in a vacuum by NASA)

THRUST = 50 to 90 uN  ~rectangular pulse (duration 30s to 40s)
SPECIFIC FORCE=  0.003 N/kW to 0.0054 N/kW (700 to 1200 times larger than a photon rocket)

______________________________

None of these appear to meet the <<"bulk" accelerated>> threshold requirement by Woodward and therefore cannot be explained by Woodward's theory as presently stated.

Observe that NASA Eagleworks reports very small measured thrust forces (average lower than 100 microNewtons) for all these tested devices in Eagleworks inverted pendulum. 

EDIT: It is also important to realize that Eagleworks noted in their report that

<<p. 14 The net force is calculated by accounting for the null force present in the system. Null testing is performed by attaching the RF drive system to a 50 ohm load and running the system at full power. The null force testing indicated that there was an average null force of 9.6 micronewtons present in the as tested configuration. The presence of this null force was a result of the DC power current of 5.6 amps running in the power cable to the RF amplifier from the liquid metal contacts. This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system. The null test data is also shown in Fig. 20.>>

So, the average null force is admitted to be 25% of the thrust force reported for the Cannae device. Eagleworks attempts to account for this null force (current causes the power cable to generate a magnetic field that interacts with the pendulum magnetic damper system) linearly as if they could just subtract this interaction:  Eagleworks does not account for nonlinear coupling that is known to be present in the system (I will show this in more detail in the future).

Maximum duration of measured thrust pulse (for Cannae and Frustum) is less than 40 seconds.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 09/27/2014 03:20 pm
Quote
It has now become apparent that:

1) These experiments were not performed at NASA Eagleworks

2) Woodward's explanation for this kind of EM Drive (sometimes called MLT thruster ) has been nullified by the experiments conducted by Brito, Marini and Galian

3) As stated by GiThruster and others, Woodward and his colleagues have abandoned this kind of (MLT) thruster as not being able to produce thrust because <<the "bulk" is not accelerated>>, and Woodward now states that <<simply charging and discharging capacitors will not produce mass fluctuations.>>

4) No Woodward MET thruster measurement has been reported to have been ever performed at  NASA Eagleworks

5) Although I have never seen an actual numerical value given for what Woodward and his colleagues consider to be a high enough acceleration for in their own words <<the "bulk" to be accelerated>>, it appears from the context of publications that the drives (SFE Boeing/DARPA, Cannae and Frustum) tested by Dr. White at  NASA Eagleworks, did not meet the <<"bulk" accelerated>> requirement by Woodward and therefore cannot be explained by Woodward's theory as presently stated.​

1)  No, the MLT experiments cited by Dr. White were performed years before there was an Eagleworks and before Dr. White had even formed his QVF conjecture.  The experiments were with AC, and at the time it was thought the design would generate thrust according to M-E theory.

2) Explanations are never nullified.   They can be falsified but that is something different than what you're suggesting here.  However the fact is, the test results at Fullerton with the MLT did show some thrust.  They showed very poor thrust for several reasons, the simplest of which is explained by the bulk acceleration conjecture, that according to the proper understanding of theory, the entire dielectric lattice needs to be accelerated both to generate M-E and to rectify it into thrust.  Try to understand at least a little of how these devices are proposed to work if you want to critique that work. 

In the MLT thruster attempts, the intention was to avoid the acoustic troubles of the previous (and again current) MET design by accelerating only the mobile Ti ion inside the BaTiO3 lattice.  The rest of the lattice was not accelerated save by the smallish remaining piezoelectric and electrostrictive effects that were not being damped out by the agent sintered into that material specifically to remove those effects.  Nembo's "Bulk Acceleration Conjecture" (BAC) was that the entire lattice needs to be accelerated and this explained why the MLT (later renamed QVF Thruster by Sonny) had disappointing results.

3)  It is completely incorrect to infer that Woodward only after the BAC, began to state "simply charging and discharging capacitors will not produce mass fluctuations.​"  Woodward has made this plain from the earliest work.​  Acceleration has always been understood as one of the two criteria necessary to generate Mach Effects and this is in papers dating back to the 90's.  The difference between before BAC and after BAC is that for a short time, it was believed that accelerating only the mobile ion inside the dielectric lattice would be sufficient.  So Woodward has not moved the goal posts.  He has simply agreed the MLT design is not the best design according to the best reading of his theory.

​4)  Of course not.  Sonny would never agree to test one of Woodward's designs.​  All of the ZPFers believe they are in competition with M-E physics.  Despite Sonny has had MLT's on the balance at Eagle, he would NEVER run them with AC the way they were designed.  The QVF model states these ought to produce thrust when driven with DC, and that is all he checked.  IIUC, he got a null result except for the switching transients which ought to produce thrust according to M-E theory.

​5)​  As I have already explained, "bulk" acceleration is not a reference to a magnitude of acceleration in the ceramic.  It is a reference to the entire lattice needing to accelerate rather than just the mobile ion.  Here is an image of a typical perovskite structure:

http://commons.wikimedia.org/wiki/File:Perovskite.svg

​Note the black center ion.  In the BaTiO3 caps used by March, Brito and Woodward, this was also a Ti ion.  The MLT only deliberately accelerated this ion.  However, the lattice or cage itself, also experiences charge carrier displacements that stretch and squish the cage​ according to the piezo and electrostrictive constants, regardless of crystal phase.  (BaTiO3 is not cubic at room temperature as is suggested by this figure.)  This stretching and squishing is repressed in most modern capacitors using BaTiO3, PZT, and other perovskites by adding a sintering agent that attenuates these accelerations--stops your modern electronics from shaking apart.

In order to accelerate the entire lattice in one direction to generate M-E and thrust, you need to use a dielectric that does not include a mechanical attenuator.  You also need a reaction mass for the lattice to press against or an acoustic reflector of some sort.  These were not included in the MLT design because accelerating only the mobile ion does not require this.  So although the MLT could work by happenstance, given the caps were somewhat rigidly locked in place and accelerated in only one direction like a 1/4 resonator rather than 2 directions like a 1/2 wave resonator, given these happenstance occurrences, the MLT could and did produce modest thrust.  However, it is much better to use the electromechanical linking of these materials and design to deliberately force them to accelerate the way we'd like.  This is the challenge of the current design and the challenge is serious enough that the MLT was originally conceived as a "silver bullet" to sidestep this challenge.  As it turns out, one can't sidestep the need for bulk acceleration.

​Hope that helps.​  And yeah, you should read the book.  There is so much important stuff in that book that even the asides make the book worthwhile.  Woodward's proposed model of the electron is going to win him a Nobel Prize if it turns out to be correct, and making these thrusters work provides significant evidence to that end.
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 03:29 pm
...Woodward's proposed model of the electron is going to win him a Nobel Prize if it turns out to be correct, and making these thrusters work provides significant evidence to that end.

Please let us know whether the following devices tested at NASA Eagleworks: 1) Cannae Testing and 2) Tapered (Frustum) Cavity Testing have met the requirement of <<bulk acceleration>> as tested at NASA Eagleworks and as reported in the paper "Anomalous Thrust..." and all other requirements necessary for the thrust of a propellant-less drive to be justified as a Woodward effect.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 09/27/2014 03:41 pm
You're asking the wrong guy.  You want to ask Paul.  But yes.  Sonny and Paul have had a dog in this hunt since way back before there was an Eagleworks.  They built a Shawyer resonator years before--which is what the tapered cavity resonator is.  They did this because like with the MLT, Sonny claims his QVF conjecture explains thrust from the tapered cavity resonator.  I'm sure he says the same about the Cannae device.  The paper you're referencing is a record of these explorations at JSC.  I don't recall there being any reference to the MLT work Sonny renamed in order to get funding for Eagle.  Obviously there would be no point publishing about old work that he knows did not provide the proper scientific controls to be taken seriously.

Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 03:51 pm
You're asking the wrong guy.  You want to ask Paul.  But yes.  Sonny and Paul have had a dog in this hunt since way back before there was an Eagleworks.  They built a Shawyer resonator years before--which is what the tapered cavity resonator is.  They did this because like with the MLT, Sonny claims his QVF conjecture explains thrust from the tapered cavity resonator.  I'm sure he says the same about the Cannae device.

Sorry, but I don't understand your answer.  These are microwave cavities, with a PTFE ("Teflon") dielectric resonator.  Eagleworks reports measuring no thrust with the PTFE dielectric resonator removed.  The devices are tested in an inverted torsional pendulum, with initial zero velocity and initial zero acceleration, according to the report.  Now, according to your understanding of the requirement of <<bulk acceleration>>,  do these tests qualify as having imparted a <<bulk acceleration>> as per Woodward's theory, yes or not? 

If "yes" how is the <<bulk acceleration>> imparted to these microwave cavities ?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 09/27/2014 04:00 pm
Quote
Now, according to your understanding of the requirement of <<bulk acceleration>>,  do these tests qualify as having imparted a <<bulk acceleration>> as per Woodward's theory, yes or not? 
I can't answer this because I'm not familiar enough with the experiment.  Certainly it is possible that this is a sloppily designed MET, meaning M-E theory would explain thrust from such a thing, but I don't know because for instance, I don't know in what manner that dielectric would accelerate.

If the dielectric is confined in such a way, that it accelerates almost equal and opposite directions as in a 1/2 wave resonator, then no, the device should not produce thrust according to M-E theory.  If instead the piezo and electrostrictive responses are confined to generate an unbalanced acceleration more to the left than to the right, resembling a 1/4 wave resonator; then yes, any thrust here can be explained by M-E theory.

I'm just not familiar enough with the experimental setup to say.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/27/2014 05:33 pm
If the dielectric is there to increase the reflectivity, then it's a 1/4 wave.

Thanks for the Slepian.  When my poor old brain integrates around an entire system I get zero.

The next term would be the interatomic nuclear force ?  (cold fusion anyone ?)

Almost forgot, the 1 wavelength "coffee can resonator" at the earths surface has an interaction wavelength of 10^10 meters.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/27/2014 06:02 pm
No, the MLT experiments cited by Dr. White were performed years before there was an Eagleworks and before Dr. White had even formed his QVF conjecture.  The experiments were with AC, and at the time it was thought the design would generate thrust according to M-E theory.

Thanks for the history lesson.  It is immaterial, since it appears that a correct re-telling of the story line is more important than the correctness of the theory or of the applicability of the experimental apparatus.

Quote from: Ron
Explanations are never nullified.   They can be falsified.

This is semantic gobbledeegook.  The explanation you have offered contains no math.

Quote from: Ron
Try to understand at least a little of how these devices are proposed to work if you want to critique that work.

It would be most helpful if there were math associated with the proposal of how the device works, specifically a mathematical and physical definition of "bulk acceleration".

Quote from: Ron
As I have already explained, "bulk" acceleration is not a reference to a magnitude of acceleration in the ceramic.  It is a reference to the entire lattice needing to accelerate rather than just the mobile ion.  Here is an image of a typical perovskite structure:

What is the mass of the illustrated PZT structure on the wiki page?  Is it the same as the proposed lattice structure?  The Wiki page shows one molecule.  What is the mass requirted?  What is the expected rate of acceleration?  What is the measured acceleration?  How much electrical power goes into the lattice?  How much acceleration is expected?  If the virtually massless lattice accelerates, what is the acceleration effect on the mass of the nuclei of the molecule?

Quote from: Ron
In order to accelerate the entire lattice in one direction to generate M-E and thrust, you need to use a dielectric that does not include a mechanical attenuator.

What?  the lattice is between atoms.  There is no mechanical attenuator at this scale.

Quote from: Ron
You also need a reaction mass for the lattice to press against...

The rest of the universe has been suggested, but this is not backed by any theory, and not included in your explanation.

Obviously there would be no point publishing about old work that he knows did not provide the proper scientific controls to be taken seriously.

Rodal has repeatedly asserted that the "scientific controls" of the inverted pendulum are not satisfactorily removing stray forces, but he has received no acknowledgement that this is the case.  Instead, people are arguing historical narratives, and offering wordy explanations of arbitrary terms.

I'm just not familiar enough with the experimental setup to say.

Which is fine.  Nobody is, and the experimentors aren't sharing.  The discussion about lattices and attenuators is only an exercise in liguistic meaning.

Why are you arguing so strenuously on a topic that you are not "familiar enough" with?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/27/2014 06:04 pm
If the dielectric is there to increase the reflectivity, then it's a 1/4 wave.

Thanks for the Slepian.  When my poor old brain integrates around an entire system I get zero.

The next term would be the interatomic nuclear force ?  (cold fusion anyone ?)

Almost forgot, the 1 wavelength "coffee can resonator" at the earths surface has an interaction wavelength of 10^10 meters.

Whaaaaa?  I can only give you the DBUG salute on that one.

http://world.std.com/~eshu/dbug/apr04.pdf
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 07:15 pm
 It is also important to realize that Eagleworks noted in their report that

<<p. 14 The net force is calculated by accounting for the null force present in the system. Null testing is performed by attaching the RF drive system to a 50 ohm load and running the system at full power. The null force testing indicated that there was an average null force of 9.6 micronewtons present in the as tested configuration. The presence of this null force was a result of the DC power current of 5.6 amps running in the power cable to the RF amplifier from the liquid metal contacts. This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system. The null test data is also shown in Fig. 20.>>

So, the average null force is admitted to be 25% of the thrust force reported for the Cannae device. Eagleworks attempts to account for this null force (current causes the power cable to generate a magnetic field that interacts with the pendulum magnetic damper system) linearly as if they could just subtract this interaction:  Eagleworks does not account for nonlinear coupling that is known to be present in the system (I will show this in more detail in the future).
Title: Re: EM Drive Developments
Post by: Ron Stahl on 09/27/2014 07:52 pm
Quote
If the dielectric is there to increase the reflectivity, then it's a 1/4 wave.
That's not why the dielectric is in there.  All of the cavity resonators are 1/2 wave EM resonators.  You're confusing EM resonance and acoustic resonance.  For an M-E device to operate, there needs to be a 1/4 wave acoustic resonance; meaning the ceramic is displacing in one direction only, not in two opposite directions, or at the very least the displacement cannot be equal and opposite as this would generate zero thrust.

Quote
This is semantic gobbledeegook.  The explanation you have offered contains no math.
No.  This is the kind of precision with which real scientists ought to communicate.  If you want the math John, go read the papers.  Didn't we go thorough all this 5 years ago?  Have you still not read the papers?  It is not my place to educate you.  If you don't understand how these devices are supposed to work, you can read up on them.  Surely, criticizing work you don't understand is a fool's errand.

Quote
It would be most helpful if there were math associated with the proposal of how the device works, specifically a mathematical and physical definition of "bulk acceleration".
The math is in the book, and in the papers that have been published on this subject every year for about 2 decades now.  You can read them at your leisure.  Let us however not pretend you would understand the math as you have no training in GR.  Unless things have changed these last few years John?  Did you go back to school?

Quote
What is the mass of the illustrated PZT structure on the wiki page?  Is it the same as the proposed lattice structure?
  Yes.  When people speak of the "lattice" they are speaking of the entire crystal in contrast to the mobile ion.  So for example, if you are talking about a single crystal form, the mass of the dielectric is the mass of the lattice.  If however you are speaking of a sintered form, the mass of the lattice could be appreciably less given any sintering agent is introduced, such as what is commonly included to attenuate electromechanical responses.  Not all sintered ceramics require a sintering agent, however.  Ceramics sintered with Spark Plasma sintering or FAST system, do not require binders, etc, and so the "lattice" mass would be the same as the ceramic mass. In this instance however, things like PZT that are tape cast, or other forms of PZT like what Woodward was most recently using, include binders the percentage of which are not specified by the manufacturer.

Quote
What is the expected rate of acceleration?  What is the measured acceleration?
This is different with every experiment.  IMHO, the proper way to know the answer to this, and it is a good question; is to use a high speed laser doppler vibrometer.  Other methods are far less precise.  Future experiments will use this method if I have anything to say about it.  It is fair to say however, that in general the accelerations generated in perovskites operating in the ultrasonic region, where the design provides a typical mechanical Q of about 700, are in the millions of gees.  The trouble is that the device also needs to oscillate at a second frequency which is not on the natural resonace of the device, and that oscillation will be tiny if not managed extremely well.  In order to know if it has been managed well, one needs a vibrometer.  Woodward tracks his accelerations with accelerometers but he cannot assign raw magnitudes to them in this way.

Quote
How much electrical power goes into the lattice?
In the case of Woodward's current thruster experiments, about 100 watts, and less than one watt is dissipated.  But you cannot infer what you suppose from this answer as there are a handful of complex qualifications I would offer were we having a technical discussion of something you understood sufficiently.  Fact is you have not asked the right question and you cannot understand the right answer either.

Quote
The rest of the universe has been suggested, but this is not backed by any theory, and not included in your explanation.
You're mixing up two different issues.  While it is true that the gravinertial flux in and out of the thruster is exchanged with the rest of the universe (and this has always been M-E theory--read the book or any of the papers published the last 20 years), in order for any 1/4 wave resonator or oscillator to function, it needs to push off a reaction mass or acoustic mirror.  Whether one creates conditions for a Mach Effect event or not, any 1/4 wave acoustic resonator requires this.  Now if one has such a resonator and then wants to generate M-E, one gets the changing mass from gravinertial flux exchange with the rest of the universe.  Different issue.  Again, you are mixing these issues because you're trying to analyze the operation of a device which you do not understand.  Read the book.

Quote
Rodal has repeatedly asserted that the "scientific controls" of the inverted pendulum are not satisfactorily removing stray forces, but he has received no acknowledgement that this is the case.  Instead, people are arguing historical narratives, and offering wordy explanations of arbitrary terms.
  Paul addressed Dr. Rodal's concerns quite well.   They're answered.  Dr. Woodward routinely addresses concerns like these in all his work, which is one reason he has more than 100 scientists and engineers on his weekly mailing list.  I doubt whether anyone is going to find fault with either Eagle's work or Woodward's in this regard, as they both constantly subject themselves to careful input on their experimental setups on a regular basis.

Quote
The discussion about lattices and attenuators is only an exercise in liguistic meaning.
Don't make the mistake thinking that just because you don't understand what I said, that Dr. Rodal does not either.  I explained in great detail for real reasons and none of that explanation was mere exercise.  You simply don't understand it, which is fine.  Read the book.

Quote
Why are you arguing so strenuously on a topic that you are not "familiar enough" with?
I'm not arguing.  I'm explaining.  You're arguing.  Eagle has been as transparent as is normally the case when offering a conference paper.  I'm just answering Dr. Rodal that I cannot tell whether the dielectric is moving in 1/4 wave acoustic fashion from the paper.  It is quite possible.  Since both the resonator geometries are asymmetric, 1/4 wave motion of whatever is in there is quite plausible.
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 08:16 pm

Quote
Rodal has repeatedly asserted that the "scientific controls" of the inverted pendulum are not satisfactorily removing stray forces, but he has received no acknowledgement that this is the case.  Instead, people are arguing historical narratives, and offering wordy explanations of arbitrary terms.
  Paul addressed Dr. Rodal's concerns quite well.   They're answered.  ... I doubt whether anyone is going to find fault with either Eagle's work or Woodward's in this regard, as they both constantly subject themselves to careful input on their experimental setups on a regular basis.

You are mistaken and/or confused with something else.  Nobody has addressed the issues I have raised concerning parasitic self-excitation of the inverted pendulum due to coupling of swinging with the torsional mode, and the nonlinear nature of the magnetic damping term in the equations of motion.  Furthermore concerning your opinion that "doubt whether anyone is going to find fault " with the experimental setup, Paul March has already stated in this forum that they are trying to address the problems with the magnetic damping (already admitted in the NASA "Anomalous.." paper) with a "2nd generation" design for the magnetic damper.

On one hand you state that you are << just not familiar enough with the experimental setup>> used by Eagleworks for their "Anomalous.." paper and on the other hand you make this blanket, predictive, statement about <<doubt whether anyone is going to find fault>> with the experimental setup.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/27/2014 08:26 pm
Teflon sound speed 1400 m/sec
Title: Re: EM Drive Developments
Post by: birchoff on 09/27/2014 08:35 pm

Quote
Rodal has repeatedly asserted that the "scientific controls" of the inverted pendulum are not satisfactorily removing stray forces, but he has received no acknowledgement that this is the case.  Instead, people are arguing historical narratives, and offering wordy explanations of arbitrary terms.
  Paul addressed Dr. Rodal's concerns quite well.   They're answered.  ... I doubt whether anyone is going to find fault with either Eagle's work or Woodward's in this regard, as they both constantly subject themselves to careful input on their experimental setups on a regular basis.

You are mistaken and/or confused with something else.  Nobody has addressed the issues I have raised concerning parasitic self-excitation of the inverted pendulum due to coupling of swinging with the torsional mode, and the nonlinear nature of the magnetic damping term in the equations of motion. ...

Sorry going to have to call a flag on the play their Rodal. What your saying is only half correct. Paul March did address the issues you initially raised (that is the open letter you wrote that aceshigh reproduced on talk polywell).  And I do not think it is too much to assume that Ron is referring to that part of this long discussion.
Title: Re: EM Drive Developments
Post by: birchoff on 09/27/2014 08:41 pm
...
Quote
What is the expected rate of acceleration?  What is the measured acceleration?
This is different with every experiment.  IMHO, the proper way to know the answer to this, and it is a good question; is to use a high speed laser doppler vibrometer.  Other methods are far less precise.  Future experiments will use this method if I have anything to say about it.  It is fair to say however, that in general the accelerations generated in perovskites operating in the ultrasonic region, where the design provides a typical mechanical Q of about 700, are in the millions of gees.  The trouble is that the device also needs to oscillate at a second frequency which is not on the natural resonace of the device, and that oscillation will be tiny if not managed extremely well.  In order to know if it has been managed well, one needs a vibrometer.  Woodward tracks his accelerations with accelerometers but he cannot assign raw magnitudes to them in this way.
...

Any idea when we will see more experimental information from Woodward. Also who is going to be taking over for him in the medium to long term, where Mach Effect research is concerned?

...
Quote
How much electrical power goes into the lattice?
In the case of Woodward's current thruster experiments, about 100 watts, and less than one watt is dissipated.  But you cannot infer what you suppose from this answer as there are a handful of complex qualifications I would offer were we having a technical discussion of something you understood sufficiently.  Fact is you have not asked the right question and you cannot understand the right answer either.
...

For the benefit of us bystanders observing this discussion. Do you mind stating what the correct question and answer is?
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 08:45 pm

Sorry going to have to call a flag on the play their Rodal. What your saying is only half correct. Paul March did address the issues you initially raised (that is the open letter you wrote that aceshigh reproduced on talk polywell).  And I do not think it is too much to assume that Ron is referring to that part of this long discussion.

@birchoff,

Paul March addressed the issue of translation of the center of gravity due to thermal expansion. 

The statement from John that Ron answered was <<Rodal has repeatedly asserted that the "scientific controls" of the inverted pendulum are not satisfactorily removing stray forces,>> Everything to do with the inverted pendulum and not thermal expansion.

 What I stated was correct.  I don't understand why Ron may think that thermal expansion is an issue with inverted pendulums.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 09/27/2014 08:48 pm
Quote
On one hand you state that you are << just not familiar enough with the experimental setup>> used by Eagleworks for their "Anomalous.." paper and on the other hand you make this blanket, predictive, statement about <<doubt whether anyone is going to find fault>>.
Yes well, I've been doing this for a decade now.  Every engineering forum is filled with people who suppose they are going to find what they assert must be there--some kind of flaw in the test system.   In every one of these forums, there are engineers who presume there must be an error in the system, because they are unable to understand the operation of the device in question and know whether it ought to operate as proposed or not.  So you're in the majority, Dr. Rodal.  I would just note to you though, that Woodward's general reading list has guys with PhD's from Cambridge and Penn State and these are not simpleton types.  They're all doing what you're proposing to do, but with real time invested to understand the systems.  The question is really, are you going to take the time to understand?

Now as to the latest tweak to the Eagle balance, I'm all for that.  I can tell you, over the last few years while Eagle was getting ready to do these tests, they had all manner of difficulties.  It generally takes a year of effort to characterize a new balance like this, and this process is greatly exacerbated when you stick the balance in stainless steel and power it with high voltage.  Just grounding the thing sufficiently is a huge task, and everyone knows this who has been involved over the years.

However, certain controls can thwart certain kinds of troubles quite easily.  I didn't read back at your specific concern, but it sounds like it is dealt with quite ably when using a dummy load on the balance.  So if you didn't get the huge response you wanted , it is likely because the concern you have already has a control in place to cope with it.

In any event, I've known Paul for a lot of years and I will indeed be surprised if he let data go to conference with spurious sources in the mix.  Paul is not sloppy in anything he does.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 09/27/2014 08:53 pm
Quote
[Any idea when we will see more experimental information from Woodward. Also who is going to be taking over for him in the medium to long term, where Mach Effect research is concerned?
Jim should just be back from vacation about now.  He just started posting to his reading list but nothing about the new test items yet.  It will be an exciting season since he finally will have some PMN on the balance--something I've been after him for since 2007.  It's dicy stuff since it has such a tiny thermal bandwidth of operation, but it also can have much improved stats over the PZT the last few years.

Heidi Fern has already committed to pursue Jim's work when he is unable.  She's that convinced Jim is right in both theory and practice.
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 08:57 pm
I didn't read back at your specific concern, but it sounds like it is dealt with quite ably when using a dummy load on the balance. 

Yes, it is apparent that you <<didn't read back at [my ]specific concern>>.

Also that you don't understand the issue of self-excitation and limit-cycles of oscillations with nonlinear damping  and coupling of torsional and swinging modes.  This is evident from your statement << it sounds like it is dealt with quite ably when using a dummy load on the balance>>   
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/27/2014 09:03 pm
Before class today, I was 183.2 pounds.  After class, 181.2.  Mostly hydrogen dioxide and sodium chloride.   I note that the sodium chloride sports a cubic lattice.  I moved more mass than that there sintered lattice  setup is ever going to move, and I just used chemical energy.

Also, true to my earlier promise, I did not buy Rodal a Scotch on Friday.

Anybody have a count on how many times the term "you" was used in post #1020?

Also, just to prove how weird the universe really is, here's a picture of my first office building.  1020 19th Street in DC.
Title: Re: EM Drive Developments
Post by: birchoff on 09/27/2014 09:20 pm
Quote
[Any idea when we will see more experimental information from Woodward. Also who is going to be taking over for him in the medium to long term, where Mach Effect research is concerned?
Jim should just be back from vacation about now.  He just started posting to his reading list but nothing about the new test items yet.  It will be an exciting season since he finally will have some PMN on the balance--something I've been after him for since 2007.  It's dicy stuff since it has such a tiny thermal bandwidth of operation, but it also can have much improved stats over the PZT the last few years.

Heidi Fern has already committed to pursue Jim's work when he is unable.  She's that convinced Jim is right in both theory and practice.

Good to hear.
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 09:41 pm
.
Does this merit a bottle of Scotch? John, when you wrote <<Rodal has repeatedly asserted that the "scientific controls" of the inverted pendulum are not satisfactorily removing >>: the issues I raised are endemic, and known, with inverted pendulums and magnetic dampening.  They are not due to scientific controls.  The alternatives I proposed are

A) to use the Cavendish type pendulum damped by an oil bath (as used in the classical experiments for the inverse-law of gravitation and the measurement of the Casimir force), and as used by Brito et.al. in their 2009 report, or

B) if vertical height is an issue, and therefore must use an inverted pendulum, it should be modified such that the thruster is horizontal at all times (to eliminate mode-coupling) as done for example by Prof. Martinez-Sanchez at MIT Aero & Astro.

I also proposed that the higher priority should be to next test at John Hopkins because they have a Cavendish type pendulum and have expressed interest (according to White's report).  To test at John Hopkins with higher priority than testing at JPL or NASA Glenn, because JPL and Glenn ( according to White's report) have proposed to also use inverted pendulums.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/27/2014 09:53 pm
​Hope that helps.​  And yeah, you should read the book.  There is so much important stuff in that book that even the asides make the book worthwhile.  Woodward's proposed model of the electron is going to win him a Nobel Prize if it turns out to be correct, and making these thrusters work provides significant evidence to that end.

What strikes me here, as someone trained in down to earth engineering but also interested in fundamental research, is that what appears (from an average mainstream science educated person) we have people applying more of engineering methodology, trying to find some variants and to improve a useful device, while the "simple" experimental evidence for any effect at all (regardless of backing theories) is obscured by this apparently endless series of various devices/various experimental setups, to the point it seems utterly unable to convince mainstream scientists of the reality of a possible experimental positive result (regardless of backing mainstream theories). If dr Woodward et al are interested in a Nobel, my feeling (as an average mainstream science educated person somehow following the topic) is that the various teams involved in experiments are choosing the wrong methodology and should follow some guidelines for fundamental research experimentalists : please produce a complete detailed description of one single self contained airtight device, thermally isolated, energetically isolated, electromagnetically shielded, that is reproducible and will guarantee anyone caring to follow the instructions to observe a thrust/power effect better than 1/c for a few seconds : even if only a few % better than 1/c would be enough for a Nobel. If some theory did prove to be useful to reach the appropriate design then all the better for the Nobel, but theories can come later.

So far my feeling is that the "propellantless propulsion proponents" are doing a really great job at NOT convincing an (admittedly already reluctant) mainstream science community that there is any effect at all. Maybe that is not their goal, maybe they prefer to nurture scepticism and keep working in their corner, with little funds and equipments and small teams, polishing a design to truly amaze us later with a whooping N/kW thruster for all to buy at RadioShack ? But it seems strange to me (and my guess to a majority of scientists and engineers), if effect is real then it is worth fundamental physics methodology, not necessarily billions $ but at least complete open access to blueprints, complete experimental datafiles (including preliminary adjustments and settings) and not just snapshots of a few screens (to be compensated for perspective! can't they dump the raw values of those instruments on some disk?) (and believe our word, this is just so typical a record it would be useless to show you the others...) scatterplots of hundreds of data points (on/off pulses) with varying parameters (positioning, frequency, power, time of the day, temperature and humidity in lab, with or without added ferromagnetic shielding here and there, with or without thermal shielding of the flex bearings...) to show correlations or absence of correlation...

I understand the limited means for small teams small budgets, but the will to log and communicate every possible detail on a stable reference experiment is lacking. NDAs are a no go for fundamental science and a poor excuse considered what is at stakes : BSM physics. What are the general feeling in the proponents ranks about the lack of recognition by the mainstream community so far ? They just don't care ?

Understand this is not an attack on persons, it is an attack on methodology. I have no secret agenda, I have no financial or professional interest in propellentless drives to fail to reach recognition, should they be possible at all. I do have an interest in scientific knowledge and good methodology, and communication to the general public.

Title: Re: EM Drive Developments
Post by: RotoSequence on 09/27/2014 10:02 pm
I agree strongly with frobnicat.

Generally speaking, it's hard to call it good science, or to believe that it's a real effect, when it only seems to manifest itself with an unending list of different devices with highly tuned, yet error prone, experimental apparatuses.
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 10:07 pm
So far my feeling is that the "propellantless propulsion proponents" are doing a really great job at NOT convincing an (admittedly already reluctant) mainstream science community that there is any effect at all. ...
I agree, that is my reaction as of late, with many exceptions.  Notably, Paul March (@Star-Drive), addressing a number of points with numbers and data.  Unfortunately he stopped frequenting this forum some time ago.  But I truly appreciate all of the responses I have seen from Paul March.  He is truly missed.

Of relevance to what is being discussed, Paul March readily admitted that they had a problem with the magnetic dampening, interacting, and therefore affecting the baseline and that they are attempting to address it with a "2nd generation magnetic damper design" (which I don't think will be enough to address it as I will show as I get the time to do so). 
Title: Re: EM Drive Developments
Post by: birchoff on 09/27/2014 11:11 pm
​Hope that helps.​  And yeah, you should read the book.  There is so much important stuff in that book that even the asides make the book worthwhile.  Woodward's proposed model of the electron is going to win him a Nobel Prize if it turns out to be correct, and making these thrusters work provides significant evidence to that end.

What strikes me here, as someone trained in down to earth engineering but also interested in fundamental research, is that what appears (from an average mainstream science educated person) we have people applying more of engineering methodology, trying to find some variants and to improve a useful device, while the "simple" experimental evidence for any effect at all (regardless of backing theories) is obscured by this apparently endless series of various devices/various experimental setups, to the point it seems utterly unable to convince mainstream scientists of the reality of a possible experimental positive result (regardless of backing mainstream theories). If dr Woodward et al are interested in a Nobel, my feeling (as an average mainstream science educated person somehow following the topic) is that the various teams involved in experiments are choosing the wrong methodology and should follow some guidelines for fundamental research experimentalists : please produce a complete detailed description of one single self contained airtight device, thermally isolated, energetically isolated, electromagnetically shielded, that is reproducible and will guarantee anyone caring to follow the instructions to observe a thrust/power effect better than 1/c for a few seconds : even if only a few % better than 1/c would be enough for a Nobel. If some theory did prove to be useful to reach the appropriate design then all the better for the Nobel, but theories can come later.

So far my feeling is that the "propellantless propulsion proponents" are doing a really great job at NOT convincing an (admittedly already reluctant) mainstream science community that there is any effect at all. Maybe that is not their goal, maybe they prefer to nurture scepticism and keep working in their corner, with little funds and equipments and small teams, polishing a design to truly amaze us later with a whooping N/kW thruster for all to buy at RadioShack ? But it seems strange to me (and my guess to a majority of scientists and engineers), if effect is real then it is worth fundamental physics methodology, not necessarily billions $ but at least complete open access to blueprints, complete experimental datafiles (including preliminary adjustments and settings) and not just snapshots of a few screens (to be compensated for perspective! can't they dump the raw values of those instruments on some disk?) (and believe our word, this is just so typical a record it would be useless to show you the others...) scatterplots of hundreds of data points (on/off pulses) with varying parameters (positioning, frequency, power, time of the day, temperature and humidity in lab, with or without added ferromagnetic shielding here and there, with or without thermal shielding of the flex bearings...) to show correlations or absence of correlation...

I understand the limited means for small teams small budgets, but the will to log and communicate every possible detail on a stable reference experiment is lacking. NDAs are a no go for fundamental science and a poor excuse considered what is at stakes : BSM physics. What are the general feeling in the proponents ranks about the lack of recognition by the mainstream community so far ? They just don't care ?

Understand this is not an attack on persons, it is an attack on methodology. I have no secret agenda, I have no financial or professional interest in propellentless drives to fail to reach recognition, should they be possible at all. I do have an interest in scientific knowledge and good methodology, and communication to the general public.

I agree with what you are saying, but I think there seems to be an assumption that Eagleworks or Dr. Woodward have something that could be so easily reproduced that a complete description is all that is needed for someone else to reproduce it. As someone who is interested in seeing this line of research carried out, my perspective is that we are really just at the beginning, where the researchers have a hypothesis and are carrying out experiments to attempt to prove those hypotheses. In Eagleworks case they think they can push on the quantum vaccum and are carrying out tests according to their idea to see if it actually can be done. While Dr. Woodward believes it should be possible to temporarily shield some matter from the effects of all the matter in the universe in just such a way to be able to coax thrust out of it. Both ideas on their face are extraordinary. But thats all they are right now. It is my perspective that Eagle works is trying to get to the point that they can provide someone with a description that can be independently verify. They just dont have that right now. As for Woodward In his book the reason he has moved from his classical MET design to MLT and back to MET is because he was unable to get a consistent thrust signal after having his designs tested in more than one way.

The real problem is, everyone seems to be starting with the assumption that what Woodward or Eagleworks has is an actual working device. While what I think they both have is akin to proof that there may be smoke on the horizon. Now they are attempting to verify that the smoke is real and it is being caused by a fire.

In a way Rodal's posts I believe are inadvertently the cause of this. I GREATLY appreciate the analysis he has provided, but in my opinion I think it has become painfully clear about 30-35 pages ago that we do not have enough information to conclusively prove or disprove that the devices work as described. At best we have conclusively proven that we don't have enough information. At this point the only move left is to carry on with our lives until we glean any more new useful information.

P.S. As a heads up to everyone Shawyer is set to give a presentation at IAC 2014 on October 03 see link here http://www.iafastro.net/iac/paper/id/21913/summary/ (http://www.iafastro.net/iac/paper/id/21913/summary/). I severely doubt he will have anything that passes my definition of useful information. My money would bet that he plans to recycle his old presentations plus reference the Eagleworks conference paper. Though this is a bet I would not mind loosing.
Title: Re: EM Drive Developments
Post by: Rodal on 09/27/2014 11:25 pm
...
@birchoff

Very thoughtful post. Yes, it is painful, because all of us search for meaningful answers, and you are right, sometimes the answers are just not there.

I have recently noticed that this type of effect appears to go back to the 1920's, at least:

<<During the 1920s, Thomas Townsend Brown was experimenting with an x-ray tube known as a "Coolidge tube," which was invented in 1913 by the American physical chemist William D. Coolidge. Brown found that the Coolidge tube exhibited a net force (a thrust) when it was turned on. Brown applied for a British patent on April 15, 1927, which was issued on November 15, 1928 as Patent No. 300,311, entitled, “Method of Producing Force or Motion.”>> http://www.sunrisepage.com/ufo/files/Brown,%20Thomas%20Townsend.%20British%20Patent%20300,311.pdf

So it is even more depressing that this apparent effect (see the March 2003 article "Force on an Asymmetric Capacitor", by Thomas B. Bahder and Chris Fazi", Army Research Laboratory, Adelphi, MD http://arxiv.org/ftp/physics/papers/0211/0211001.pdf) of very small forces involved with electromagnetic devices has such a long and meandering history.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/28/2014 11:36 am
I agree with what you are saying, but I think there seems to be an assumption that Eagleworks or Dr. Woodward have something that could be so easily reproduced that a complete description is all that is needed for someone else to reproduce it. As someone who is interested in seeing this line of research carried out, my perspective is that we are really just at the beginning, where the researchers have a hypothesis and are carrying out experiments to attempt to prove those hypotheses. In Eagleworks case they think they can push on the quantum vaccum and are carrying out tests according to their idea to see if it actually can be done. While Dr. Woodward believes it should be possible to temporarily shield some matter from the effects of all the matter in the universe in just such a way to be able to coax thrust out of it. Both ideas on their face are extraordinary. But thats all they are right now. It is my perspective that Eagle works is trying to get to the point that they can provide someone with a description that can be independently verify. They just dont have that right now. As for Woodward In his book the reason he has moved from his classical MET design to MLT and back to MET is because he was unable to get a consistent thrust signal after having his designs tested in more than one way.

Ok, this is preliminary and difficult. But, regardless of theories, they claim results, they claim difficult to obtain and measure but real non classical effects. Sceptic but open minded readership is not requiring cautionary phrase "assuming any propellantless effect at all is possible" at each single slide or paragraph of the publications, but the overall tone is that they have no doubt they are onto something, and trying to improve that something. But there is nothing to improve if there is nothing, and it is very possible there is nothing, that propellantless effects (better than 1/c) is not part of reality, like FTL travels. It would be very desirable but it could be just plain impossible. No matter bright theories to explain how it could be possible, and it is certainly worth investigating such possibilities, in the end it might be just plain impossible. And that is what best contemporary theories and their theoreticians are telling. They could be wrong. They very possibly could be right, even if wrong on a lot of other things.

If all the signals are false, then there is no progress to be made by comparing the signals. For instance it is irrelevant to make a theory that better explains why a thruster could better push on vacuum with a dielectric resonator than without, it is irrelevant to make devices with dielectric resonators because seeing a signal would be better than no signal. I think that they are trying too hard to see something, and not hard enough to see nothing.

There is the device and the experiment to test the device. As for the experimental part there is a force measuring system and an enclosure around the device to insure the device is isolated from the rest of the experiment and can't expel anything or push on any wall or field. Working in a vacuum is a kind of enclosure, but it is far from sufficient. If any effect at all is possible then this enclosure is irrelevant for applications. For determining the all or nothing answer of "is the effect real ?" this enclosure is paramount. The experimenters and theoreticians here seem to put so much accent on the device, some real effort on the force measuring (but maybe not the appropriate apparatus), but not much about the enclosure.

Except when they do, then we get clear answer but null result, no effect (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1262274#msg1262274) (for what was previously claimed as real) : so what was the progress made by believing in the previous results for some time ? If effect is impossible, any progress is illusory.


Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/28/2014 11:53 am
Progress in instrumentation is still important progress.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 12:42 pm
I think that they are trying too hard to see something, and not hard enough to see nothing.
An excellent summary.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/28/2014 01:15 pm
Quote from: Notsosureofit
Progress in instrumentation is still important progress.

yes it is, but it is not a progress to better propellantless drives unless they are possible at all. Alright this could be progress toward knowing if it is possible or not, but what I mean is that if the accent is put on magnitude of signals in experiments with spurious effects rather than eliminating (or being able to filter out) all spurious effects on clean settings first then the progress is in making better spurious effects, not better real effect. I'm thinking here of the dean drive (http://en.wikipedia.org/wiki/Dean_drive).
Quote from: wikipedia dean drive
In 2012 a researcher attempting to characterize the Woodward effect, another proposed reactionless drive effect, has stated that she carefully designed her experiments to specifically exclude any "Dean drive" effects: the unintended interaction with the environment in, around or touching the apparatus. She considered these effects "spurious noise".
It appears to me some people are spending a lot of energy at improving spurious effects as if it were a progress toward a real effect. As for the later, considering the real effect is impossible and there is therefore no real part to be distinguished from spurious noise, improving signal magnitude is no progress at all. The null results of experiments by Brito/Marini/Galian are a progress. Not because the result is null and I would want standard physics to win, but because it appears as a clean result (within the sensitivity...). Obviously if you were to produce an apparently clean positive it would be under much more scrutiny and attacks than a null result...

I believe involved experimentalists (of recent discussed research) are intelligent people, trying to do serious work to assess and eliminate or filter out spurious effects and produce a clean setup for their result. Also I understand this is difficult, and it takes time and budgets. The feeling though is that they are a bit too much enthusiast on believing this is real and put too much in device designs and variations and not enough in isolation and shielding. Not saying no effort at all is made on that, or to report or answer on those spurious aspects, but not enough to be convincing for such extraordinary claims. Again, Dean drive... false progress. Even if we did learn some things about "unsymmetrical frictional resistance" (useful but not as much as reactionless forces, by a light year) and about optimising such "dean drive effect" : not much useful at all, except maybe for robot actuation, but then probably better to study for this specific goal from the start as for moving around a robot a dean drive would be a poor comparison to a device that don't pretend to be isolated from ground effects (while still using them but in a less obvious manner).

Title: Re: EM Drive Developments
Post by: frobnicat on 09/28/2014 01:34 pm
In other words, see any progress here ? :

https://www.youtube.com/watch?v=vYliuFLMIHY (https://www.youtube.com/watch?v=vYliuFLMIHY)

What if all those recent experiments are only more high-tech less obviously not beyond standard physics ? 

(how is it possible to include a video directly inside the post ?)
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 01:48 pm
(how is it possible to include a video directly inside the post ?)

it works automatically by copying the link, as in this video:

https://www.youtube.com/watch?v=-mKxMoCr29c

or the video you posted:

https://www.youtube.com/watch?v=vYliuFLMIHY

Do not use the  "Insert Hyperlink" key
Do enter a "carriage return" also known as "Enter" key right after the video link.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/28/2014 01:52 pm
Progress in publishing ?
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 02:04 pm
Progress in publishing ?
You noticed (at the end of the demonstration) that the presenter was holding for the audience an Antigravity Propulsion book.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 02:19 pm
Does this merit a bottle of Scotch? John, when you wrote <<Rodal has repeatedly asserted that the "scientific controls" of the inverted pendulum are not satisfactorily removing >>: the issues I raised are endemic, and known, with inverted pendulums and magnetic dampening.  They are not due to scientific controls.

Huh?

Maybe run this thru yer grammar checker, kemosabe?  I am using the term "scientific controls" in its plain English sense, which  in this case, may not include the stricter scientific sense that you might be referring to.  Here's what I think you are saying:

The "endemic issues" of inverted pendulums, which include magnetic damping and such should not be confused with "scientific controls" pertaining to differentiating null results from detected results.  I just lumped the endemic issues into the subject of scientific controls.

Howzabout sharing your definition of "scientific controls"?

And one more thing.  I remember only promising a drink, not the whole bottle.  Or was that the Lapfrog speaking?

... but the will to log and communicate every possible detail on a stable reference experiment is lacking.

I admire your style of writing.

It is indeed the case that the "will to log and communicate every possible detail" is lacking.  With the experimental results reported in the "apparently endless series of various devices" as a basis, one reads posts like the "#1020 'you' post", and finds no corroborating information nor pragmatically useful explanation of either the underlying theory nor of the experimental apparatus.  The methodology of theory and experiment is simply not served.

...there seems to be an assumption that Eagleworks or Dr. Woodward have something that could be so easily reproduced that a complete description is all that is needed for someone else to reproduce it.

It is not so much as an assumption, by my take.  It is more that questions are simply not being answered, and what appear to be objections to theory and experiment are not being countered.

I think that they are trying too hard to see something, and not hard enough to see nothing. ... If effect is impossible, any progress is illusory.

And.  Some of the enthusiasts are getting far too emotional about it.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 02:24 pm
Progress in publishing ?
You noticed (at the end of the demonstration) that the presenter was holding for the audience an Antigravity Propulsion book.

Well, of course they're going to try and sell the book.

If we can tentatively accept that the stage floor is the "scientifically controlled" equivalent of the conference room table, what made that device hover?

The whirly bird thing was converting electrically caused rotary action into forward momentum.  He needs to tighten up the mechanism, since it would be a bumpy ride, but it looks like it works.

What say you to those two devices?
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 02:36 pm

Maybe run this thru yer grammar checker, kemosabe?  I am using the term "scientific controls" in its plain English sense, which  in this case, may not include the stricter scientific sense that you might be referring to.  Here's what I think you are saying:

The "endemic issues" of inverted pendulums, which include magnetic damping and such should not be confused with "scientific controls" pertaining to differentiating null results from detected results.  I just lumped the endemic issues into the subject of scientific controls.

Howzabout sharing your definition of "scientific controls"?
I was interpreting "scientific controls" with emphasis on "controls" and "scientific" just being a modifier.  I wanted to emphasize that what I am questioning is not anything to do with automatic http://en.wikipedia.org/wiki/Automatic_control or human control http://www.bartlett.psychol.cam.ac.uk/human%20control%20systems.html of the experimental setup.  One of the responders seems to have addressed this as finding "fault" with the experimenter in having made some mistake during the experiments, which is not at all what I question.  What I questioned is the use of a magnetically damped inverted pendulum because it is subject to self-excitation and mode coupling of swinging with torsional modes.

Having said that, I see that Wikipedia has a different view of the meaning of "scientific controls" http://en.wikipedia.org/wiki/Scientific_control  as <<an experiment or observation designed to minimize the effects of variables other than the single independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements. >>, so yes, kernosabe, according to this definition, your use of "scientific control" was well utilized.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 02:48 pm
...there seems to be an assumption that Eagleworks or Dr. Woodward have something that could be so easily reproduced that a complete description is all that is needed for someone else to reproduce it.

Huh?, reproduction of results by independent scientists is what I always understood to be the definition of the scientific method.

Does @birchoff or Prof. Woodward have a different definition of the scientific method?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 02:51 pm
...

Having said that, I see that Wikipedia has a different view of the meaning of "scientific controls" http://en.wikipedia.org/wiki/Scientific_control  as <<an experiment or observation designed to minimize the effects of variables other than the single independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements. >>, so yes, kernosabe, according to this definition, your use of "scientific control" was well utilized.

Thanks, kemosabe, since the oracle's daffynition more or less agrees with mine..
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 03:03 pm
...there seems to be an assumption that Eagleworks or Dr. Woodward have something that could be so easily reproduced that a complete description is all that is needed for someone else to reproduce it.

Do the Eagleworks or Prof. Woodward's experiments to be easily reproduced elsewhere, in addition to "a complete description," need  a "personal touch" that only Prof. Woodward and/or a few other special people can provide?

I hope that the implication is not that Prof. Woodward's experiments are akin to experiments that need a "personal touch", for example http://en.wikipedia.org/wiki/Spoon_bending.

Certainly not.  If the experiments cannot be easily reproduced by other scientists at other locations, they cannot  be considered part of the scientific progress.
Title: Re: EM Drive Developments
Post by: frobnicat on 09/28/2014 03:04 pm
What say you to those two devices?

- Offboard high voltage generator + light construction + ionic wind, basically same effect as developed for "no moving parts" cooling fans (http://www.electronics-cooling.com/2012/03/ionic-winds-a-new-frontier-for-air-cooling/). Interesting but irrelevant for space propulsion (needs an atmosphere to push on). Might learn something for ion thrusters (but then mass has to be expelled). Low or high altitude propulsion possible with generators of high enough power/mass ratio (as a lot of other schemes...). Don't know how it compares to usual propellers. Sure that no anti-gravity or beyond standard physics are involved.

-  "Unsymmetrical frictional resistance" of some sort. Net forward momentum effect will vanish as soon as in 0G and not in contact to any exterior mass : irrelevant for space propulsion. No beyond standard physics are involved, though it might be tricky to explain precisely the apparent forward momentum, given complex mechanical coupling and, er, somehow chaotic modes of giggling. Even with low friction bearings, one does get a force component tangential to the rail when the bearing is rolling, this tangential component's magnitude depends on the normal components. By wriggling the centre of mass and the rotational momentums in such a way that the normal component is not symmetrical relative to periodic forward/backward movements, like for instance being light when forward and stomping when backward, you can get a net forward momentum. That and possibly a small help by "accompanying" the device's wires.

thanks for the video posting tip Rodal
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 03:11 pm
Progress in publishing ?
You noticed (at the end of the demonstration) that the presenter was holding for the audience an Antigravity Propulsion book.

Well, of course they're going to try and sell the book.

If we can tentatively accept that the stage floor is the "scientifically controlled" equivalent of the conference room table, what made that device hover?

The whirly bird thing was converting electrically caused rotary action into forward momentum.  He needs to tighten up the mechanism, since it would be a bumpy ride, but it looks like it works.

What say you to those two devices?

The first device is presented almost like a magician's trick, and saying what made it hover is like trying to ascertain what trick did a magician use.  I suspect ionic wind and the visible wires.

For the second device I suspect "Dean drive" effect (observe the frictional stick-slip and jumping in the tracks) plus the (unconscious guiding) influence of the cables held by the person.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 03:16 pm
One of the responders seems to have addressed this as finding "fault" with the experimenter in having made some mistake during the experiments, which is not at all what I question.

It is always clear that a person's moral character is not defined by whatever mistakes that person might make in an experiment.  Cognitive infiltration, as I use the term, comes into play when the hominem is deliberately substituted for the criticism of the experimental or theoretical setup.

Also, I was using the term "control" loosely to refer to experimental controls.  Kinda like the placebo effect.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 03:20 pm
In the ionic wind device, one would be able to feel the "breeze", then.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 03:24 pm

The whirly bird thing was converting electrically caused rotary action into forward momentum.  He needs to tighten up the mechanism, since it would be a bumpy ride, but it looks like it works.

For the second device I suspect "Dean drive" effect (observe the frictional stick-slip and jumping in the tracks) plus the (unconscious guiding) influence of the cables held by the person.

The cables trail the device and appear more to be an actual drag or load that the device must carry.  It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.

Why couldn't this be done?
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 03:25 pm
In the ionic wind device, one would be able to feel the "breeze", then.
http://alternative-medicine.knoji.com/how-ions-affect-your-mood/
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 03:34 pm
It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.
Why couldn't this be done?

I was given this windup toy by a Swiss friend  :) years ago that demonstrates a chaotic walking motion produced by an off-center-of-rotation CG of rotating mass:

http://www.youtube.com/watch?v=pj0QpOIdtoQ

It also relies on stick-slip friction at the legs.  Also observe that it is important to have long lightweight legs in order to maximize the motion.

The chaotic, limit-cycle motion results in a "walking motion".  One can derive the equations of motion (using the Lagrangian and the non-conservative term due to stick-slip friction).  It is an interesting example of nonlinear equations of motion resulting in this "walking motion".  It is a very inefficient and difficult to control motion, so it is of no practical use for walking robots.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 04:59 pm
It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.
Why couldn't this be done?

Think of how you move your body to roller skate.

It can only work when there is stick-slip friction against a surface, just like you need friction to roller skate.  Devices like this that need stick-slip friction against a surface cannot work in outer space. No frictional surface on outer space.

For motion on the surface of our planet, relying on stick-slip friction motion is much more inefficient than, for example, a Tesla using an electric motor to directly drive its wheels, relying on rolling friction of its tires.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 05:10 pm
It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.
Why couldn't this be done?

Think of how you move your body to roller skate.

Ima good skater on ice and roller blades.  The secret is pushing on your blade at right angles to its axis, so that you don't roll or slide.  That's the friction.  Which you know.  As an aside, one of the things I still can't really do is jump into a right angled dramatic brake in either medium. 

Unless the wheels of the whirly bird device were frictionally directional, it appears to move forward without canting its wheels along their vertical axis, and developing friction in the same way as ice skating or roller blading.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 05:27 pm
It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.
Why couldn't this be done?

Think of how you move your body to roller skate.

Ima good skater on ice and roller blades.  The secret is pushing on your blade at right angles to its axis, so that you don't roll or slide.  That's the friction.  Which you know.  As an aside, one of the things I still can't really do is jump into a right angled dramatic brake in either medium. 

Unless the wheels of the whirly bird device were frictionally directional, it appears to move forward without canting its wheels along their vertical axis, and developing friction in the same way as ice skating or roller blading.
Look at the critter wind-up toy motion for the rest of the story. 
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 05:32 pm
The frictional rolling of a driven wheel against a surface always comprises a "stick" region at the leading side of rolling motion and a sliding region behind it.  The sliding is due to the shear stress exceeding the friction times the normal load.  The extent of stick and sliding in a rolling wheel is governed by the amount of normal force, the amount of shear force and the coefficient of friction.  The coefficient of friction is nonlinear: it is lower for sliding motion than for sticking motion.   
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 05:36 pm
An Italian:

http://www.youtube.com/watch?v=RTyHSjMVcB4



A physical model of the so-called 'Ziegler column', a two-degree-of-freedom system, exhibiting flutter instability as induced by dry friction.

Ziegler was at the Aeroelastic and Structures Research Laboratory at MIT during two different periods at the time of the Apollo program.  (http://www.hansziegler.com/obituaries_en.html)

 (See video for divergence instability at 5:40 and at 6:19).

****Observe that in these Italian experiments we also have an inverted "pendulum" fixed at one end and experiencing an axial load (due to friction in this case) at the free end.  There is no lateral load responsible for the instability. There is no dark energy, quantum vacuum or Woodward transient mass effect for the lateral motion. It is an axial load dynamic instability where only classical mechanics and friction are present.

The case of the magnetically damped inverted pendulum may experience a different kind of dynamic instability: there is a mechanical non-conservative nonlinearity due to the magnetic damping and there are nonlinear terms coupling the swinging motion to the torsional motion.  Add to that the fact that they acknowledge coupling of the electric power and the magnetic dampening affecting the baseline***
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 05:42 pm
It is apparent that some people that dismissed my questioning of the magnetically damped inverted pendulum don't understand self-excited motion (see: http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263257#msg1263257).  Such motion is not at all the same thing as the forced harmonic vibration of a linear dynamic system due to a natural frequency.

It used to be the case (1930's to 1960's) that Aerospace Engineers were cognizant of flutter and divergence instabilities.  As flutter problems have been successfully addressed in aerospace, perhaps dynamic instability has fallen in popularity.  That would be too bad, because one cannot blindly use a Finite Element package to analyze these problems, as modeling the nonlinearities and coupling in the equations of motion is of paramount importance.

No linear analysis can solve the transient motion of a dynamic instability problem.  A nonlinear dynamic finite element package doesn't automatically "know" what kind of nonlinearity and coupling is involved in a given problem.  The engineer has to model such nonlinearities and coupling in order to solve the problem.

At MIT there was an "Aeroelasticity and Structures Research Laboratory" started by Bisplinghoff (before he became one of the top people at NASA at the beginning of the Apollo program) (http://www.amazon.com/Aeroelasticity-Dover-Books-Aeronautical-Engineering/dp/0486691896/ref=sr_1_sc_1?ie=UTF8&qid=1411926883&sr=8-1-spell&keywords=aerolasticity+bispinghoff ).  They had people like Ashley (who went to Stanford) , Halfman, Witmer, Pian, Mar, Dugundji and others.  During the late 1980's MIT closed the "Aeroelasticity and Structures Research Laboratory" and has been concentrating in other areas.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 06:08 pm
What's most worrisome for assessing testing results of EM drives is that apparently some people ( http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263257#msg1263257) don't understand divergence instability: where the motion is impulsively towards one side, due to self-excitation.  (See video by the Italian above for a very simple demonstration at 5:40 and at 6:19).

The assumption that the testing device, particularly when measuring microNewtons, is not to be questioned, is really worrisome !  And the assumption that simplistic linear analyses of the testing device suffice is also worrisome.  And compound this by the fact that instead of using classical, better understood, testing devices (as the Cavendish hanging pendulum damped by oil, as used by famous physicists for testing the inverse square law of gravitation and testing the Casimir force, and as also used by Brito, Marini and Galian to nullify the EM drive results), people are using magnetically damped inverted pendulums and other non-analyzed nonlinear testing devices.
Title: Re: EM Drive Developments
Post by: Vultur on 09/28/2014 07:32 pm
I have recently noticed that this type of effect appears to go back to the 1920's, at least:

<<During the 1920s, Thomas Townsend Brown was experimenting with an x-ray tube known as a "Coolidge tube," which was invented in 1913 by the American physical chemist William D. Coolidge. Brown found that the Coolidge tube exhibited a net force (a thrust) when it was turned on.

Very interesting.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/28/2014 08:16 pm
So far my feeling is that the "propellantless propulsion proponents" are doing a really great job at NOT convincing an (admittedly already reluctant) mainstream science community that there is any effect at all. ...
I agree, that is my reaction as of late, with many exceptions.  Notably, Paul March


coincidentally, the only one who posts here who directly works on propellantless propulsion and the only one who can address the questions raised. I wonder how Frobnicat expects propellantless propulsion proponents here to answer the questions raised when only people directly working with those experiments can answer such questions.

It´s a bit unfair of Frobnicat to demand specific answers from us that only a few people WORKING on those experiments can effectively give, and then say we are not helping the cause.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 08:26 pm
....

@aceshigh,

That's not my reading of @frobnicat. My reading of @frobnicat is that according to the scientific method, the expectation is that the complete testing protocol be made available for other scientists to independently be able to reproduce such experiments, and that until those complete testing protocols are made available such tests are not completely following the scientific method.


 @frobnicat also stated that @frobnicat << think(s) that they (the experimenters) are trying too hard to see something, and not hard enough to see nothing. >>
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 08:29 pm
I was given this windup toy by a Swiss friend ...

Yahbut:  This has nothing to do, that I can tell, with the whirly bird device.  When we were kids, my brother and I had a football game.  There was a vibrating table, and the football players had 1/4"x3/4" bases with short 1/16" directionally bent fibers.  You'd set up the play, turn the table on, and the players would vibrate themselves forward, with the subtle differences in their bases giving or retarding advantage.  A slightly different concept from your vibrating spindly legged wing ding device.

I mention the childhood game since it produced forward motion by vibration, and your wing ding thing vibrates and produces forward motion.

(Sorry for having introduced non-vetted terminology.)

An Italian:

First, if my italian were as good as his English, I'd be pleased to speak Italian with a southern drawl.

Second, this is not the problem of the whirlybird device.  There is no force along the axis of the axle, which is constrained by the track.  Or are you saying that the whirlybird motion, which does have a horizontal component, is exactly the cause of "flutter instability", which, constrained by the tracks,  manifests in forward roling motion?

The frictional rolling of a driven wheel against a surface always comprises a "stick" region at the leading side of rolling motion and a sliding region behind it.

I knew that, but would have phrased it differently.  Still the whirly bird device in the video above purports to have freely spinning wheels, not driven wheels.

where the motion is ... due to self-excitation.

Please remember that this is a family site.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 08:38 pm
I was given this windup toy by a Swiss friend ...

Yahbut:  This has nothing to do, that I can tell, with the whirly bird device.  ....
Well, if you are going to argue that the analogies I presented are not perfect analogies, I concede that specific point: you are right: they are not perfect analogies.  However they contain the essential points: stick-slip friction and motion of the center of gravity.

But, I strongly disagree with the statement that it has nothing to do.

If you won't accept an imperfect analogy to understand what's going on, what would convince you? A solution of the equations of motion derived from a Lagrangian + the nonconservative force (friction)? That would practically qualify for a paper (just like the one that the Italian published in the prestigious Journal of the Mechanics and Physics of Solids), which at the moment I don't have the inclination to do  :)

However, I will put further effort to further clarify the NASA Eagleworks test results, as I get the time....
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 08:39 pm
It´s a bit unfair of Frobnicat to demand specific answers from us that only a few people WORKING on those experiments can effectively give, and then say we are not helping the cause.

First, it is not a political "cause". Either it is a real effect, or it is not.

Second, the "unfairness" is the deliberate abandonment of input from the experimentors on the apparent basis that they seem to be in a snit because they give every appearance of confusing questioning the apparatus with questioning the expermentor's moral motives.

Third, it is a great disappointment to hear ad hominem attacks rather than physical descriptions of the actual mass and acceleration included in, just to take the most recent example, the case of "buld acceleration".

Fourth, if only the few "WORKING" people can answer specific questions, then there can be no broad agreement with their work, by definition, since only they have the "answers".
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 08:47 pm
I was given this windup toy by a Swiss friend ...

Yahbut:  This has nothing to do, that I can tell, with the whirly bird device.  ....
Well, if you are going to argue that the analogies I presented are not perfect analogies, I concede that point: ...

Not at all my point, my imperfect interlocutor.  In my intemperate Boetian (http://en.wikipedia.org/wiki/Boeotia#Pejorative_term) approach, I'm just not seeing the windup toy nor the sticky friction stick slip [terminology edit.] explanation... [More editing...]  as pertaining to the wheeled whirly bird device.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 09:03 pm
Not "sticky friction", but stick slip. 

The coefficient of friction is lower during sliding motion than with incipient sliding.

Think of a block acted by a normal force N, against a surface, with a static coefficient of friction mu in between them, a (lower) sliding coefficient mus, and a lateral force P.

For P<mu * N, there is no sliding, and we can have 0 < P < mu * N

For any load greater than Ps= P = mu * N we get sliding.

During sliding P = mus * N, where mus < mu.

Hence during sliding P < Ps

This is a nonlinear relation with an instability occurring at P=Ps.  Think about the consequences.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 09:05 pm
Exsqeeze me on my ineptitude, but I am not following.  We're talking about a wheel.  Break it down for me, willya?
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 09:10 pm
Exsqeeze me on my ineptitude, but I am not following.  We're talking about a wheel.  Break it down for me, willya?
The wheel has a (leading) stick zone and (following) sliding zone. 

You should not think of the wheel as perfectly rolling.

When you state that the wheel is "not driven" , it is not driven by a torque, but it is driven by changes in CG position producing inertial forces along the track because of coupling.  There is coupling of the 3D degrees of freedom.  You cannot analyze the problem as a linear problem.  You have to take into account the coupling of the DOF.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/28/2014 09:15 pm
I think I see.   

I can get on a railroad flat car, and jerk backwards.  The car will move forward.  If I coast with it, gradually bringing my body forward at a rate of less than the "sticky friction", I will get to a point where I can jerk backwards again, and I can thus "propel" the railroad flat car forward.

Is this correct?
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 09:19 pm
I think I see.   

I can get on a railroad flat car, and jerk backwards.  The car will move forward.  If I coast with it, gradually bringing my body forward at a rate of less than the "sticky friction", I will get to a point where I can jerk backwards again, and I can thus "propel" the railroad flat car forward.

Is this correct?

I have not done that in a railroad flat car, so I cannot say yes. 

You also have to do the side to side rocking.

But it occurs to me that perhaps I was not communicating well that "sliding" does not mean sliding with no friction.

You slide with FRICTION , you still slide but you TRANSMIT forces (sorry about the caps to emphasize and type fast)
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 09:21 pm
And when you slide a wheel with friction you can transmit forces in both directions: along the rolling motion and perpendicular to the rolling motion (and any direction in between).
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 09:22 pm
Even with the wheel sliding everywhere (all sliding, no sticking) you still transmit forces
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 09:23 pm
So, if you would have this contraction working on rolling balls (rather than wheels), able to spin in all directions. perhaps it would not work or would not work as well.

Like the ball on old fashioned mouse.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 09:27 pm
That would be an interesting experiment, to put this device on rolling balls instead of wheels like the ball on an old fashioned mouse.

On a flat granite surface instead of on a track
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 09:29 pm
If the balls would be able to freely spin in ALL directions, on a flat surface, I don't think the device would work.

However even ball bearings do not perfectly roll.  But I would be willing to bet that on balls on a flat surface it would work much less effectively than on wheels on a track
Title: Re: EM Drive Developments
Post by: frobnicat on 09/28/2014 09:34 pm
I think I see.   

I can get on a railroad flat car, and jerk backwards.  The car will move forward.  If I coast with it, gradually bringing my body forward at a rate of less than the "sticky friction", I will get to a point where I can jerk backwards again, and I can thus "propel" the railroad flat car forward.

Is this correct?

Exactly, this is not efficient with good free wheels but there is no such thing as perfect wheels without friction and non linearities, such imperfections that allow to communicate some momentum from mobile to road. Those mechanical devices can't work in vacuum free floating or free falling 0G and no contact with support : by the book (http://en.wikipedia.org/wiki/Newton%27s_laws_of_motion) the centre of mass of device is always following a perfect inertial trajectory. Now if the device is big enough (has enough span) so that different parts of it taste different gravity gradients, like with rotating tethers, then by the book it could be possible to have some slingshot effect to exchange some momentum with some nearby massive body without expelling anything, my guess, at least you can't approximate the whole system by only its centre of mass and need to see the details.

guys you are typing too fast !
Title: Re: EM Drive Developments
Post by: frobnicat on 09/28/2014 10:03 pm
So far my feeling is that the "propellantless propulsion proponents" are doing a really great job at NOT convincing an (admittedly already reluctant) mainstream science community that there is any effect at all. ...
I agree, that is my reaction as of late, with many exceptions.  Notably, Paul March


coincidentally, the only one who posts here who directly works on propellantless propulsion and the only one who can address the questions raised. I wonder how Frobnicat expects propellantless propulsion proponents here to answer the questions raised when only people directly working with those experiments can answer such questions.

It´s a bit unfair of Frobnicat to demand specific answers from us that only a few people WORKING on those experiments can effectively give, and then say we are not helping the cause.

Answers to this by other contributors suit me.
Just to add (shouldn't) I'm a bit harsh yes, I wouldn't say unfair but you could say "it's easy". Yes it's easy, I recognize having become accustomed to some pretty high standards when it comes to reading and learning from research, from the comfort of my armchair. I'm not demanding to enthusiasts answers they don't have. Just sharing thoughts. Expressing views: beware of borderline methodology, we (sceptics) beg you (enthusiasts) not to dive into black science, for your own sake.
http://www.nerdcoremovement.com/wp-content/uploads/2014/07/Black-Science-1-6.jpg

Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/28/2014 10:17 pm
"Exactly, this is not efficient with good free wheels but there is no such thing as perfect wheels without friction and non linearities, such imperfections that allow to communicate some momentum from mobile to road. Those mechanical devices can't work in vacuum free floating or free falling 0G and no contact with support : by the book the centre of mass of device is always following a perfect inertial trajectory. Now if the device is big enough (has enough span) so that different parts of it taste different gravity gradients, like with rotating tethers, then by the book it could be possible to have some slingshot effect to exchange some momentum with some nearby massive body without expelling anything, my guess, at least you can't approximate the whole system by only its centre of mass and need to see the details."

Yah, rotating in a grav/gradient allows you to tranfer angular momentum anget a sort of "lift"    ala the "spindizzy"
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 10:34 pm
Expressing views: beware of borderline methodology, we (sceptics) beg you (enthusiasts) not to dive into black science, for your own sake.
http://www.nerdcoremovement.com/wp-content/uploads/2014/07/Black-Science-1-6.jpg

So, we started by considering the quantum vacuum which leads to dark energy (the cosmological constant), while others proposed dark matter (axons), and now we are warned about staying away from dark science  :D

To me this points to the "Light side of the force" --> classical physics, and stay away from the Dark Side  :D for an explanation.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 10:55 pm
Friction not as easy as some may think

http://www.youtube.com/watch?v=uZGbtK2KBoY

 Prof. Walter Lewin  MIT

8.01 is the introductory freshman Physics course at MIT.  There are many flavors of it.
Title: Re: EM Drive Developments
Post by: Rodal on 09/28/2014 11:21 pm
Did you see the "dry ice" floating device at the end of that MIT lecture?  It would be interesting to challenge inventors that have devices like that contraction (rotating chaotically) that John was interested in (that I think relies on friction), to have them run on such a single omnidirectional low-friction support  point instead of several wheels on a track.  Of course, twice the weight of the device should not exceed the max weight allowed for a film to exist for the dry ice to work.

I write "twice the weight" to take into account dynamic (inertial) effects.

Only one "dry ice" support.  The contraction should sit on top.  Let's see whether it moves without any external force.

********
Did you see the experiment at the end with the insect pulling the book, etc ?

I wonder how many microNewtons force is that insect able to pull
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/29/2014 12:04 am
Ok...

1) This Biefield-Brown effect appears legitimate...at least in an atmosphere.  From some of the terms employed in the Wiki, it seems almost like some of the experimenters are attempting to get this effect to work in a vacuum, with ambiguous results at best.

2) Something that has been brought up a couple times before on this thread yet never really looked into:  Apparently - according to a print article I read some years ago, Shawyer (Sp?) became interested in this class of drive upon being hired to investigate why satellites were consuming far more thruster fuel than they should have trying to maintain their correct orbits.  He concluded the cause was microwave devices on board these satellites that were generating actual thrust.  This might be worth taking a peek at again.  Rodal, any thoughts here? 

3) I have brought this up before, but...could 'dark matter' or 'dark energy' be at play here?  From what I have read, most efforts to investigate dark matter or dark energy involve microwaves.  Hence, if microwaves are deemed useful to detect these phenomena, then perhaps microwaves could influence/excite/interact with them somehow to produce the observed thrust?  Or does this cause as many issues with the laws of physics as the other explanations?

And as to the various tests and devices, it seems to me the researchers are making an impressive effort to counter testing artifacts, as well as testing out different classes of device to see which one works best.   Of course, their best efforts might not be good enough. 

Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 12:17 am
...

3) I have brought this up before, but...could 'dark matter' or 'dark energy' be at play here?  .explanations?

...

I will answer your question #3 for now.

Dr. White's explanation (pumping "the quantum vacuum") can be interpreted as using dark energy because in some theories the cosmological constant is related to both dark energy and the quantum vacuum.  Not enough is known yet about dark energy to say much more than that.

*********
My personal opinion for whatever it's worth, is that the  (few watts) microwave devices (Cannae and Frustum-type) cannot make real the virtual particles of the quantum vacuum.  One needs a petawatt laser to be able to make real electron/positron virtual pairs.  A petawatt is 10^15 watts, that is:
1000000000000000 watts.

Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/29/2014 12:43 am
But that is enough to make extremely long wavelength "dark matter" particles, always assuming they exist of course.
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 12:53 am
But that is enough to make extremely long wavelength "dark matter" particles, always assuming they exist of course.

Good point.  But aren't they supposed to be "weakly interacting"?

On the other hand "weakly interacting" dark matter may be more likely to interact than a non-real-in-a-microwave (virtual) particle pair from the quantum vacuum. 
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/29/2014 12:55 am
Esp in a 2-photon interaction.

Edit : still need a non-linear GR term.

(I know I'm crossing GR and StdM here but that's what has to happen for EM to do anything)

(beats the rest-mass-changes foolishness)
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 01:01 am
Esp in a 2-photon interaction.

Edit : still need a non-linear GR term.

<<First calculations of rate of e+–e− pair production in photon-photon collision was done by Lev Landau in 1934.[1] It was predicted that the process of e+–e− pair creation (via collisions of photons) dominates in collision of ultra-relativistic charged particles—because those photons are radiated in narrow cones along the direction of motion of original particle greatly increasing photon flux.

In high-energy particle colliders, matter creation events have yielded a wide variety of exotic heavy particles precipitating out of colliding photon jets (see two-photon physics). Currently, two-photon physics studies creation of various fermion pairs both theoretically and experimentally (using particle accelerators, air showers, radioactive isotopes, etc.).
>>

http://en.wikipedia.org/wiki/Matter_creation

http://en.wikipedia.org/wiki/Two-photon_physics
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/29/2014 01:07 am
Exactly !
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 01:10 am
Esp in a 2-photon interaction.

Edit : still need a non-linear GR term.

(I know I'm crossing GR and StdM here but that's what has to happen for EM to do anything)

Is this a theoretical possibility, or is there any experimental evidence of such nonlinear GR term?

If only a theoretical possibility has anyone looked at whether such a nonlinear GR term could be introduced without producing other effects that would run contrary to the Universe as we know it?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/29/2014 01:18 am
Still looking, but hints would be things like tapered cavities and asymmetric dielectrics which would add dispersion to the cavity photons, hence the nonlinear term.  (you'll be the first to know if I find something while digging)
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 01:23 am
Still looking, but hints would be things like tapered cavities and asymmetric dielectrics which would add dispersion to the cavity photons, hence the nonlinear term.  (you'll be the first to know if I find something while digging)

Excellent statement <<that's what has to happen for EM to do anything)>>   :)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/29/2014 01:46 am
You could compare to wave-tank model w/ a slope and a step wall.  The nonliniarity comes in at the liquid drop formation.  But where do you get the value for this case ?  Plank drops ?

(notice there is a classical static force in these cases, shock waves etc etc)
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 01:54 am
My mind can't get around the energy required

<< To create an electron-positron pair the total energy of the photons must be at least 2mec2 = 2 × 0.511 MeV = 1.022 MeV (me is the mass of one electron and c is the speed of light in vacuum), an energy value that corresponds to soft gamma ray photons. The creation of a much more massive pair, like a proton and antiproton, requires photons with energy of more than 1.88 GeV (hard gamma ray photons).>>
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/29/2014 01:56 am
Not as long as you keep asking for electron/positron pairs (real), not gonna happen.

Same problem w/ creating "Plank drops" if they were to exist, way to much energy.

If the effect is real you need a large momentum to energy ratio so c is way too big but a plank mass would be nice if you could couple to it.

Leaving now, but I may have to think about the water drop analogy.  The nonlinearity (in the dispersion curve) is present before the drop "breaks" (is created ?) 
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 02:22 am
Not as long as you keep asking for electron/positron pairs (real), not gonna happen.

Same problem w/ creating "Plank drops" if they were to exist, way to much energy.

If the effect is real you need a large momentum to energy ratio so c is way too big but a plank mass would be nice if you could couple to it.

Leaving now, but I may have to think about the water drop analogy.  The nonlinearity (in the dispersion curve) is present before the drop "breaks" (is created ?)

A Planck mass as in a Micro black hole ? 



EDIT:  Wait, only now I saw <<You could compare to wave-tank model w/ a slope and a step wall.  The nonliniarity comes in at the liquid drop formation.  But where do you get the value for this case ?>>

I have to think about that....
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 02:59 am
dark matter ?

Pierre Sikivie [in 1983]  showed that dark matter axions can be detected on Earth by converting them to microwave photons in an electromagnetic cavity tuned to the axion mass and permeated by a strong magnetic field. This is the principle of the Axion Dark Matter eXperiment (ADMX) at the University of Washington in Seattle.  It uses a resonant microwave cavity within in a large superconducting magnet to search for cold dark matter axions in the local galactic dark matter halo

http://www.phys.washington.edu/groups/admx/home.html

http://www.phys.ufl.edu/~tanner/PDFS/Hoskins11prd-Hires-10Hz.pdf


<<We describe the ADMX receiver in detail as well as the analysis of narrow band microwave signals. We demonstrate the sustained use of a SQUID amplifier operating between 812 and 860 MHz with a noise temperature of 1 K. The receiver has a noise equivalent power of View the MathML source in the band of operation for an integration time of View the MathML source.>>

<<ADMX converts axions to detectable microwave photons via the inverse Primakoff effect (   http://en.wikipedia.org/wiki/Primakoff_effect  ) within a tunable, high quality factor (Q ~ 50000) microwave cavity immersed in a strong magnetic field.>>

<<The ADMX detector consists of a 1-m tall, 0.5-m diameter, copper plated, stainless steel, right cylindrical
cavity kept at 1.8 K and placed in a 7.6 T magnetic field>>

Comparing the quality factors, Eagleworks measured quality factor for the Frustum was 18,100 with a power-forward/power-reflected difference of 16.74 watts and the average measured thrust was 50.1 micronewtons. So that is Q~18,100 compared with Q~50,000 at ADMX. Also Eagleworks run a quality factor of 22000, with applied power of 2.6 watts, net average thrust of 55.4 micronewtons.

Comparing frequencies, Eagleworks run at twice the required frequency:  1936.7 MHz compared with the 812 and 860 MHz at ADMX.

We are missing the 7.6 T strong magnetic field in the Eagleworks experiment.  The only magnetic field in the Eagleworks  experiments is the one produced by the three neodymium (NdFeB Grade N42) block magnets, which is there only by chance ( to dampen the swinging and torsional oscillations of the inverted pendulum).  The magnetic damper is located about a foot away from the tested microwave device (Cannae or Frustum).

For comparison, the magnetic field intensity at the surface of a neodymium magnet is 1.25 T


So, perhaps Eagleworks should see what difference it makes to have the neodymium magnets next to the tested device  :)

Title: Re: EM Drive Developments
Post by: cuddihy on 09/29/2014 03:02 am

Ok, this is preliminary and difficult. But, regardless of theories, they claim results, they claim difficult to obtain and measure but real non classical effects. Sceptic but open minded readership is not requiring cautionary phrase "assuming any propellantless effect at all is possible" at each single slide or paragraph of the publications, but the overall tone is that they have no doubt they are onto something, and trying to improve that something. But there is nothing to improve if there is nothing, and it is very possible there is nothing, that propellantless effects (better than 1/c) is not part of reality, like FTL travels. It would be very desirable but it could be just plain impossible. No matter bright theories to explain how it could be possible, and it is certainly worth investigating such possibilities, in the end it might be just plain impossible. And that is what best contemporary theories and their theoreticians are telling. They could be wrong. They very possibly could be right, even if wrong on a lot of other things.

If all the signals are false, then there is no progress to be made by comparing the signals. For instance it is irrelevant to make a theory that better explains why a thruster could better push on vacuum with a dielectric resonator than without, it is irrelevant to make devices with dielectric resonators because seeing a signal would be better than no signal. I think that they are trying too hard to see something, and not hard enough to see nothing.

There is the device and the experiment to test the device. As for the experimental part there is a force measuring system and an enclosure around the device to insure the device is isolated from the rest of the experiment and can't expel anything or push on any wall or field. Working in a vacuum is a kind of enclosure, but it is far from sufficient. If any effect at all is possible then this enclosure is irrelevant for applications. For determining the all or nothing answer of "is the effect real ?" this enclosure is paramount. The experimenters and theoreticians here seem to put so much accent on the device, some real effort on the force measuring (but maybe not the appropriate apparatus), but not much about the enclosure.

This is now several pages back but didn't want to leave it unchallenged -- frobnicat, it's not a detour for Eagleworks or Woodward to be focusing, decades into their separate work, building thrust levels as a primary focus compared to eliminating spurious, conventional sources of potential thrust. The fact is, the effort to eliminate spurious sources can go on forever if you are pumping hundreds of watts into a box and measuring micronewtons at a small distance above the noise threshold. In Woodward's case it's been over I believe 17 years of experiments.

The one thing that changes the dynamic is if you can increase the thrust/power to the level where spurious sources of thrust are differentiated by the power level. The larger the thrust being measured, the easier it is to figure out the source.

So even if the theory is wrong, after so many years of chasing something uncertain, and if you're convinced either by the underlying theory or previous results, surely it makes sense to keep trying to increase the thrust while only slowly chipping away at the spurious potential sources.
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/29/2014 03:30 am
Quote
Pierre Sikivie [in 1983]  showed that dark matter axions can be detected on Earth by converting them to microwave photons in an electromagnetic cavity tuned to the axion mass and permeated by a strong magnetic field. This is the principle of the Axion Dark Matter eXperiment (ADMX) at the University of Washington in Seattle.  It uses a resonant microwave cavity within in a large superconducting magnet to search for cold dark matter axions in the local galactic dark matter halo

http://www.phys.washington.edu/groups/admx/home.html

http://www.phys.ufl.edu/~tanner/PDFS/Hoskins11prd-Hires-10Hz.pdf


<<We describe the ADMX receiver in detail as well as the analysis of narrow band microwave signals. We demonstrate the sustained use of a SQUID amplifier operating between 812 and 860 MHz with a noise temperature of 1 K. The receiver has a noise equivalent power of View the MathML source in the band of operation for an integration time of View the MathML source.>>

<<ADMX converts axions to detectable microwave photons via the inverse Primakoff effect within a tunable,
high quality factor (Q ~ 50000) microwave cavity immersed in a strong magnetic field.>>

<<The ADMX detector consists of a 1-m tall, 0.5-m diameter, copper plated, stainless steel, right cylindrical
cavity kept at 1.8 K and placed in a 7.6 T magnetic field>>


We are missing the 7.6 T strong magnetic field in the Eagleworks experiment.  The only magnetic field is the one produced by the magnetic damper, which is there only by chance (mainly to dampen the swinging oscillations of the inverted pendulum and also the torsional oscillations).  The magnetic damper is located about a foot away from the tested microwave device (Cannae or Frustum).

Eagleworks has three Neodymium (NdFeB Grade N42) block magnets interacting with the pendulum’s aluminum angle to dampen oscillatory motion.

For comparison, the magnetic field intensity at the surface of a neodymium magnet is 1.25 T

So would these 'dark matter axioms converted to microwave photons' result in net thrust...if that is what is going on? 
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 03:42 am
dark matter?

Can't answer your question, they run at twice the frequency required, less than half the Q at Washington, and the main problem is that the magnetic field was ~1 T instead of ~7T, was there only by chance and too far away (a foot from the tested device).

Not really clear (even if axions do exist and if some interaction would take place) how would this generate propulsion.

We don't even know whether axions do exist.  They are trying to detect them at Washington.

As far-fetched as this would be, sounds certainly much more plausible than pumping the (dark energy) Quantum Vacuum... :)
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/29/2014 03:52 am
Quote

The interaction would be the other way around, photon interaction...

Ok, so microwave photons are creating (?) dark matter axioms?  (trying for clarity here, though this sounds a little like my earlier speculation)

Quote

Can't answer your question, they run at twice the frequency required, less than half the Q at Washington, and the main problem is that the magnetic field was there only by chance and far away (a foot from the tested device).

As far-fetched as this would be, sounds certainly much more possible than pumping the Quantum Vacuum...

Assume that by sheer chance if nothing else, the drive built and tested by the Eagleworks team is 'using microwave photons to create dark matter axioms,' which seems at least plausible as everything connected with dark matter has giant question marks attached.  If this is the case, then in your best view, would this qualify as a 'propellentless drive' or 'EM drive?'  And would we be in serious violation of the laws of physics here?



Title: Re: EM Drive Developments
Post by: frobnicat on 09/29/2014 09:11 am
Quote

The interaction would be the other way around, photon interaction...

Ok, so microwave photons are creating (?) dark matter axioms?  (trying for clarity here, though this sounds a little like my earlier speculation)

Quote

Can't answer your question, they run at twice the frequency required, less than half the Q at Washington, and the main problem is that the magnetic field was there only by chance and far away (a foot from the tested device).

As far-fetched as this would be, sounds certainly much more possible than pumping the Quantum Vacuum...

Assume that by sheer chance if nothing else, the drive built and tested by the Eagleworks team is 'using microwave photons to create dark matter axioms,' which seems at least plausible as everything connected with dark matter has giant question marks attached.  If this is the case, then in your best view, would this qualify as a 'propellentless drive' or 'EM drive?'  And would we be in serious violation of the laws of physics here?

Dark matter is believed to be composed of real particles, WIMPs (http://en.wikipedia.org/wiki/Weakly_interacting_massive_particles) or axions (http://en.wikipedia.org/wiki/Axion). Various hypotheses for their parameters... ongoing experiments keep excluding more and more of the easiest (theoretically ? don't know for sure, experimentally for sure) parts of the parameter space (mass, electroweak coupling...). Ultra sensitive dedicated experiments have yielded no definitive answer so far (we would have heard about !) even if some candidate signals have been reported. Wimps would be high energy >>GeV while axions would be low mass (circa neutrinos or even bellow ?).

Speculations :

H1/ Given those scales if interaction with microwaves is possible it would need axions, not WIMPs.

H2/ I agree this would be much more plausible (as a source of thrust) than other more exotic explanations : even if unknown those would be real particles with real momentum to exchange with, within the formalism of relativistic QFT.

We need to discriminate two very different situations

S1/ Coupling a local RF field with existing axions that just happen to be there : pushing on the local dark matter. Since this matter is real but not interacting there is 0 chance that the average velocity of this "dark gas" is synchronised with rotating earth surface or even with earth centre of mass on its orbit around the sun. It is possible that this dark average velocity is in the same direction and grossly similar magnitude as solar system (sun) velocity orbiting the galaxy, but unknown for sure. What is certain is that in such a situation (coupling with existing dark matter) the device in a lab would see a strong relative wind of magnitude at least 30km/s (and possibly up to a few 100s km/s) with direction and exact magnitude depending of orientation to the stars (periodicity of 23 hours, 56 minutes sidereal time (http://en.wikipedia.org/wiki/Sidereal_time) and day of the year (earth velocity on orbit around sun, relative to galactic referential). Will try to do some order of magnitude roughing to develop quantitatively this situation. Dr Rodal do you know of any attempt in the literature to characterize sidereal or year time periodicity of the various thrusters results ? That could explain why the results (if real) appear to be erratic...

S2/ Making (producing) axions in the device and letting them escape (undetected) in an asymmetric flow. If you want "no serious violation of the laws of physics" (even with unknown particle but still inside relativistic QFT framework) then this would be at best equivalent to a photon rocket (light particles with near c expelled velocity) or worse (heavy particles <<c) because of the higher energy to make real heavier particles (relative to the momentum benefit). So with axions it would be basically like making and expelling neutrinos, undetected or hard to detect jet, but still expelled mass_energy_momentum. Thrust/power on the order of 1/c at best. At least 2 orders of magnitude below the worst reported results (when non null results where reported).

Best
Title: Re: EM Drive Developments
Post by: frobnicat on 09/29/2014 10:45 am

Ok, this is preliminary and difficult...
.../...
If all the signals are false, then there is no progress to be made by comparing the signals...


This is now several pages back but didn't want to leave it unchallenged -- frobnicat, it's not a detour for Eagleworks or Woodward to be focusing, decades into their separate work, building thrust levels as a primary focus compared to eliminating spurious, conventional sources of potential thrust. The fact is, the effort to eliminate spurious sources can go on forever if you are pumping hundreds of watts into a box and measuring micronewtons at a small distance above the noise threshold. In Woodward's case it's been over I believe 17 years of experiments.
But but but, if those thrust levels are false, I mean not about any backing theory but by the most basic experimental criteria : thrust/power > 1/c with no loss of mass (beyond the mass equivalence of energy involved) and not directly or indirectly pushing on a nearby ground. Those are exactly the conditions of applicability of the effect for space propulsion (and cheap energy generation BTW). This is the extraordinary experimental claim. I insist on the experimental aspect of it : possible backing theories are interesting, but need not be considered to discuss the practical implications of such experimental result, nor the methodology to ascertain the reality of the results (that is, it fulfils the above criteria). So for commodity what I call a false effect is a thrust or force that is not fulfilling those requirements, while a true effect does.

My point was, if measured forces are false effect then it is pointless to focus on devices with better thrust levels, unless very specifically this shows that the effect is false. For instance (excuse the cheap analogy, just to make my point clear) say some team of medieval scientists is interested in flying/hovering. They might note that jumping is a good start, gets them closer to the situation they want. But only for a limited amount of time. So they try to jump on a scale and measure the average weight. By integrating the weight over time they notice a small disparity of the average with the weight at rest. They deduce (posito quod deducunt ?) that a moving object has a different weight, on average, when compared to a resting mass. Now they will try to optimise the effect (lower average weight) by finding the best way to repetitively hop. They will likely succeed and getting better and better at having a lower average weight on the scale they will claim that surely there must be something since something is improving, so they are onto something. Looking at that with modern eyes we clearly see that this is a dead-end, they are only improving on exploiting some complex hard to understand measuring apparatus imperfection and coupling with varying weights, therefore improving on fooling themselves, as far as flying/hovering is concerned.

It will sound harsh and maybe unfair to put forward this cartoonesque analogy, given the genuine efforts of Woodward March et al for so many years. Even sceptics on this thread are convinced of the sincerity of those science adventurers and that we need people to take risks and explore unconventional things, otherwise we would not be discussing at length those results and theories, we wouldn't even care criticize.

Point is : " the effort to eliminate spurious sources can go on forever" will be the case if there is no true effect here, and we are just confirming the (expected) fact that it is just plain impossible, within ever better accuracy. Which is valid and interesting scientific progress : excluded at 300000/c, excluded at 1000/c, excluded at 1.0001/c ...  But then it would always be possible to say "this device is not producing thrust, but another one, backed by a better theory, could..." so yes it is endless, and will most likely be if no real effect is possible.

So before trying to improve thrusts levels of some design, please do the experiments in such a way that the effect has true meaning. If it is impossible (for budget/technical reasons) to get a clean yes/no answer to the question "is it real at all ?" then it is irrelevant (scientifically speaking) to get better thrusts and you would just be getting better at fooling yourself.

Being unable to build a consistent and reproducible experiment in 17 years is completely compatible with "no true effect is possible" or "true effect is possible but were never encountered yet", and less and less compatible with "some true effect was witnessed at some point". Regardless of priors and theories.

Quote
The one thing that changes the dynamic is if you can increase the thrust/power to the level where spurious sources of thrust are differentiated by the power level. The larger the thrust being measured, the easier it is to figure out the source.

So even if the theory is wrong, after so many years of chasing something uncertain, and if you're convinced either by the underlying theory or previous results, surely it makes sense to keep trying to increase the thrust while only slowly chipping away at the spurious potential sources.

If "my" theory is correct (true effect is impossible) : the thrust is spurious, trying to augment it is trying to augment a spurious effect. At some point it could appear clearly as spurious because it was augmented. Ok, I give you that. But it is also possible that in this antagonistic interplay between lowering the effects one recognize as spurious and augmenting the effects believed to be true (still spurious, but not recognized as such), and changing constantly from set-ups, devices, experimental conditions... one is just keeping on the level of confusion needed to maintain an illusion of true effect and progress when there is none.

So even if augmenting the thrust could be a way to find and understand it as a spurious effect (real progress) my take is that it is not the best way. Focus should be on a good appropriate balance and isolating the device, first, like Brito et al. Then if you have a positive result, this is a clean result, apply for Nobel. Else, null result (like Brito et al), this is also a clean result. Then try another theory/design. Don't expect better thrusting as any guideline for the new design as this is all or nothing, either you have a real effect (and improvement can come later, after the Nobel) or you have no real effect (and improving thrust is pointless). So every new design is a blank page.

Consider our medieval scientists, after some time at becoming expert at hoping on a given scale to optimise the averaged apparent weight they build a new and better scale. The experience gained in hoping to fool a mechanical scale is still useful to get non null result with the new model of scale, but not as good. Disparate results... but still non null, and still possible to refine the aptitude to fool this new kind of scale... (also at lower levels). Better and better scales, lower and lower effects, but still non null, and still possible to "improve" on any given scale. At some point a monk remarks that blowing downward has a very small but significant and continuous effect on apparent weight. That would be a real effect (for the goal of flying/hovering). What was gained in terms of progress by all those years of hoping when discovering this new real effect ? Better scales, I grant you that, but for the real effect it's like starting from a blank page.

This theory is falsifiable : show us a working reproducible effect fulfilling the requirements beyond any doubt. I'm not saying it would be easy (especially since I more and more believe this is impossible) but if it is possible, the methodology appears far from fundamental research standards. And I'm not the only one with this feeling. And a lot of them educated and usually open minded people won't even care sharing that thought but directly trash anything like "propellantless propulsion" in the abstract, not the least because the apparently poor methodology strategies and high confusion.

Best
Title: Re: EM Drive Developments
Post by: frobnicat on 09/29/2014 11:31 am
and to hit the nail on the experimental head :
The answer when asking about a clean null result is "oh yeah, but we have that theory (please read the book) that says that indeed this particular device shouldn't produce real thrust". Wait, what ? So the similar devices tested before that was reported as real results should have reported null ? Why they didn't ? And, if it proves impossible or too difficult to tell exactly why previous experiments reported positive as they should have reported null, what makes anyone believe that the new experiments with the new device from the new theory won't suffer from the same confusion between real and spurious results ?

How could a single result in years be true and not being amenable to a clean reproducible device ?
And if none of the result were true, how is the experimental situation different from a blank page ?
It would be if we were at least sure they were all null, at least it would be excluding some designs (smaller blank page) but this is not even the case...

Title: Re: EM Drive Developments
Post by: frobnicat on 09/29/2014 12:12 pm
To sum up "what we want", or what mainstream scientists would expect (if any effect possible) :

(theory 1) device 1 -> ... clean null result
(theory 2) device 2 -> ... clean null result
(theory 3) device 3 -> ... unconclusive
(theory 4) device 4 -> ... clean null result
(theory 3) device 3 (+better instrumentation) -> ... clean null result
(theory 5) device 5 -> ... clean null result
...
(theory n) device n -> ... small but clean uncontroversial positive
-> Nobel
-> improve on device n
-> improve on theory n

Experimentally, each stage is blank page, the only progress is that the blank page is shrinking (clearly excluded designs). Sorry, this is not incremental (maybe for theory it could). This is all or nothing, hit or miss, and when missing there is no indication by how far. And there may be no target at all, be open for that. Obviously progress on instrumentation can be made incrementally, but not for the effect per se.

Teams times and budgets might make it hard to adhere to such an ideal scheme, that is understandable, but the observed deviations to orthodox methodology are way to important to give the subject the credibility it deserves "Because of the enormous commercial possibilities should it succeed (http://www.montypython.net/scripts/flysheep.php)".
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 12:59 pm

S1/ Coupling a local RF field with existing axions that just happen to be there : pushing on the local dark matter. Since this matter is real but not interacting there is 0 chance that the average velocity of this "dark gas" is synchronised with rotating earth surface or even with earth centre of mass on its orbit around the sun. It is possible that this dark average velocity is in the same direction and grossly similar magnitude as solar system (sun) velocity orbiting the galaxy, but unknown for sure. What is certain is that in such a situation (coupling with existing dark matter) the device in a lab would see a strong relative wind of magnitude at least 30km/s (and possibly up to a few 100s km/s) with direction and exact magnitude depending of orientation to the stars (periodicity of 23 hours, 56 minutes sidereal time (http://en.wikipedia.org/wiki/Sidereal_time) and day of the year (earth velocity on orbit around sun, relative to galactic referential). Will try to do some order of magnitude roughing to develop quantitatively this situation. Dr Rodal do you know of any attempt in the literature to characterize sidereal or year time periodicity of the various thrusters results ? That could explain why the results (if real) appear to be erratic...


@frobnicat
Excellent analysis.  <<Coupling a local RF field with existing axions that just happen to be there : pushing on the local dark matter. >>  better explains the amount of thrust except for the problem of physical orientation of the thruster.  When Eagleworks turned the thruster device around by 180 degrees such that the ("Teflon") PTFE dielectric resonator was  oriented in the opposite direction, the measured thrust force also was in the opposite direction, so the thrust force followed the physical orientation of the thruster.

So, the thruster cannot be acting like the spinnaker on a sailboat, moving forward with the wind coming from its back, since in that case the boat could only move in the same direction as the wind, regardless of orientation of the boat. 

It would need to act more like a sailboat using its sail to go forward with the wind blowing at an angle against it.

This is possible in a sailboat because its sail is shaped like the wing of an airplane.  Wind blowing against the boat at an angle inflates the sail, and it forms an airfoil shape, creating a difference in pressure that pushes the sail perpendicular to the wind direction.

I have no idea what could be creating the "airfoil shape" in an EM thruster using dark matter.

I have to review again Dr. White's idea to "pump the quantum vacuum" but I recall it was akin to squeezing it  and using its expansion reaction to propel the spacecraft forward.  My recollection is that it did not see the quantum vacuum as a wind with a given direction.

Bottom Line: If Dark Matter's wind has a defined direction orientation, the only way that flipping the thruster around by 180 degrees could result in thrust in the opposite direction, with the thrust corresponding to physical orientation of the PTFE dielectric resonator is for the EM drive to be forming an airfoil shape to interact with the Dark Matter.  I do not see anything in the EM drive that would be forming such an airfoil shape. If we cannot come up with something in the EM drive that would be forming an airfoil shape, or if we don't conclude that Dark Matter is a directionless wind and the EM drive works by pumping the Dark Matter (as proposed by Dr White for the vacuum) then this possibility has to be discarded since it is nullified by the experiment.

If that would be the case we would be moving to consider possibility S2 for Dark Matter, where  <<Thrust/power on the order of 1/c at best. At least 2 orders of magnitude below the worst reported results>>.

Then this would be yet another explanation that produces by itself at least 2 orders of magnitude lower specific force,  and the measurements could be explained by self-excitation and mode coupling of the magnetically damped inverted pendulum.
 
Title: Re: EM Drive Developments
Post by: frobnicat on 09/29/2014 01:41 pm
.../...
It would need to act more like a sailboat using its sail to go forward with the wind blowing at an angle against it.
.../...
If we cannot come up with something in the EM drive that would be forming an airfoil shape, or if we don't conclude that Dark Matter is a directionless wind and the EM drive works by pumping the Dark Matter (as proposed by Dr White for the vacuum) then this possibility has to be discarded since it is nullified by the experiment.
.../...

A sail is a passive momentum exchange device : no input power from the ship. When considering a powered device the analogy would be more like a propeller : take the medium at a certain velocity vector and blow it on another velocity vector (magnitude and or direction). Some incoming relative speed wind effect could be smaller than the net thrust if exhaust speed is much higher. 20 km/h relative wind, forward or backward, relative to 400 km/h exhaust, would make only 10% difference. The reported thrust measurements (in "anomalous thrusts..." for instance) show some amount of disparity that could accommodate for this explanation up to a certain ratio... and indeed the ratio could be much lower as to be difficult to see at all. A scatterplot of enough data points, with magnitude against sidereal time could show such effect down to a certain threshold.

Quantitatively, the fact that direction reversal of thruster reverses thrust while keep roughly same magnitude (within what, 10% ?) would imply that the exhaust velocity of dark matter would be about 10 times higher than "dark matter wind" which in all likelihood is a least on the order of 30km/s -> more than 300km/s exhaust velocity. Got to check if it makes sense energetically. Also got to check if there is enough dark matter density to push onto. Quick search : this paper (http://inspirehep.net/record/878672/files/arXiv%3A1011.6323.pdf) states about 1GeV/cm3. That sounds like not much. But no time to make quantitative argument right know, probably no posting for the next 48H.
Title: Re: EM Drive Developments
Post by: JasonAW3 on 09/29/2014 01:51 pm
Guys,

Is it possible, that this device is somhow acting like and eductor type of device causing electrons to interact with dark matter, not so much as to push off from it, but to pull it along with itimparting more of a physical thrust?

  I imagine that there would be a fall off of effective kinetic energy from the electron stream produced as it interacts with the far heavier Dark Matter, but the overall effect may be sufficent to cause the observed effects.

I'm probably completely off base, but, it makes a whole lot more sense that "pushing off of Dark Matter"
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 01:54 pm
.../...
It would need to act more like a sailboat using its sail to go forward with the wind blowing at an angle against it.
.../...
If we cannot come up with something in the EM drive that would be forming an airfoil shape, or if we don't conclude that Dark Matter is a directionless wind and the EM drive works by pumping the Dark Matter (as proposed by Dr White for the vacuum) then this possibility has to be discarded since it is nullified by the experiment.
.../...

A sail is a passive momentum exchange device : no input power from the ship. When considering a powered device the analogy would be more like a propeller : take the medium at a certain velocity vector and blow it on another velocity vector (magnitude and or direction). Some incoming relative speed wind effect could be smaller than the net thrust if exhaust speed is much higher. 20 km/h relative wind, forward or backward, relative to 400 km/h exhaust, would make only 10% difference. The reported thrust measurements (in "anomalous thrusts..." for instance) show some amount of disparity that could accommodate for this explanation up to a certain ratio... and indeed the ratio could be much lower as to be difficult to see at all. A scatterplot of enough data points, with magnitude against sidereal time could show such effect down to a certain threshold.

Quantitatively, the fact that direction reversal of thruster reverses thrust while keep roughly same magnitude (within what, 10% ?) would imply that the exhaust velocity of dark matter would be about 10 times higher than "dark matter wind" which in all likelihood is a least on the order of 30km/s -> more than 300km/s exhaust velocity. Got to check if it makes sense energetically. Also got to check if there is enough dark matter density to push onto. Quick search : this paper (http://inspirehep.net/record/878672/files/arXiv%3A1011.6323.pdf) states about 1GeV/cm3. That sounds like not much. But no time to make quantitative argument right know, probably no posting for the next 48H.

Well the propeller also has an airfoil shape (each blade of the propeller must be shaped like an airfoil), the difference, as you say being that the propeller is powered and not passive. The sail in a sailboat actually also needs some amount of human power and directional control (the sailor needs to constantly be controlling the force and trim of the sail).

 I don't see at the moment what could be giving an airfoil shape, and controlling the the airfoil, or as a set of moving airfoils as in a propeller. 

You are right that the propeller would make more sense since it is always fixed in the body (spacecraft or EM drive) direction, it does not need the human control attention that a sail needs.  The propeller better corresponds to the experimental findings of flipping the drive around by 180 degrees.

Unfortunately, I do not "see" the propeller in these EM drives.

Are you thinking of the photons inside the cavity ? or are you thinking of the PTFE dielectric resonator?

See you in 48 hours  :)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/29/2014 01:55 pm
You guys up there are great.  Even if you all are arcane, and subject to a mite too much dark hamster!  Still, your arguments can be followed.

Point is : " the effort to eliminate spurious sources can go on forever"

To continue with the analogy just for a bit, as the day goes by, the monks sweat, and they get lighter, increasing their hover time.  In addition, they also get tireder, decreasing their hover time.  There are many spurious forces that they must factor into their equations, as they attempt to improve their "thrust levels" as a means to proving their nascent theory.

The medieval scientist analogy is a good one.

Quote from: Frobnicat
If "my" theory is correct (true effect is impossible) : the thrust is spurious, trying to augment it is trying to augment a spurious effect. At some point it could appear clearly as spurious because it was augmented. Ok, I give you that. But it is also possible that in this antagonistic interplay between lowering the effects one recognize as spurious and augmenting the effects believed to be true (still spurious, but not recognized as such), and changing constantly from set-ups, devices, experimental conditions... one is just keeping on the level of confusion needed to maintain an illusion of true effect and progress when there is none.

... if it is possible, the methodology appears far from fundamental research standards

Which is the main point that Rodal has been hammering for many pages, to no acknowledgement. 

This is all or nothing, hit or miss, and when missing there is no indication by how far. And there may be no target at all, be open for that.

The analogy here is sighting in a new rifle/scope combo.  If you try it first at a hundred yards, you're not likely to hit the paper, therefore you don't know whether to adjust the scope up, down, left or right.  You have to tighten up the experimental apparatus by getting so close to the paper that you can't miss, then gradually backing off and verifying which direction the scope needs to be adjusted.

If, when you're close to the target, and you're still not making holes in the paper, you need to re-adjust your hypothesis completely.  Maybe you're firing blanks, not bullets, and it is not a scope adjustment issue at all.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/29/2014 01:58 pm
A sail is a passive momentum exchange device ...

Well the propeller also has an airfoil shape...

To continue with this line of reasoning over the next 48 Hamsters, consider making your "propellor" out of a magnetically induced force field.

I want to believe in the ether.
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 02:02 pm
Guys,

Is it possible, that this device is somhow acting like and eductor type of device causing electrons to interact with dark matter, not so much as to push off from it, but to pull it along with itimparting more of a physical thrust?

  I imagine that there would be a fall off of effective kinetic energy from the electron stream produced as it interacts with the far heavier Dark Matter, but the overall effect may be sufficent to cause the observed effects.

I'm probably completely off base, but, it makes a whole lot more sense that "pushing off of Dark Matter"

Sorry, I guess I'm not feeling that creative/imaginative in the morning.  I don't quite see something that could be acting like a "sail-like" airfoil, or a moving set of airfoils (a propeller) or an eductor type of device, in these EM drives.  Need some help from you to enable me to see these.

Furthermore, @frobnicat, @notsureofit and I have been discussing the photons of the microwave interacting with hypothetical (dark matter) axions (since at least the frequency of the microwave is in the right neighborhood for this, see my earlier post).

I don't understand where are the electrons coming from when you state <<causing electrons to interact with dark matter>>  are you thinking of field emission of electrons from a cracked PTFE dielectric resonator?

And why do you think that electrons in these microwave devices makes a whole lot more sense than photons to interact with (Dark Matter) axions?  Look at this : http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263849#msg1263849

Sorry, I need some more coffee to wake up, I may be the one completely off base  :)
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 03:16 pm
A sail is a passive momentum exchange device ...

Well the propeller also has an airfoil shape...

To continue with this line of reasoning over the next 48 Hamsters, consider making your "propellor" out of a magnetically induced force field.

I want to believe in the ether.

Hey kernosabe, I came up with some numbers here http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263849#msg1263849

Please give us your numbers for your ether magnetically induced force field  :)

You also get 48 Hamsters-Hours to provide those numbers.  If you do you get a drink.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/29/2014 04:06 pm
I want to believe in the ether.

Hey kernosabe, I came up with some numbers here http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263849#msg1263849

Please give us your numbers for your ether magnetically induced force field  :)

You also get 48 Hamster-Hours to provide those numbers.  If you do you get a drink.

Ok.  How about Numbers 6:24-26?

Sadly, you ask for that which I cannot provide.  I want to believe in the ether, but it is not a fundamental need for me.  I guess it is my intuition which suggests that information can travel instantaneously, and also that there ought to be an instantaneous explanation for inertia.

The mental image of a spaceship using an "invisible" propeller shaped force field pushing against the "invisible" ether is an intriguing one for me.

You had mentioned considering a 24 hour fluctuation in the "Force" as a means of determining the direction of the "inertial wind".  Might I also throw out this paper, regarding the idea that there is change in the gravitational constant?

What is the nature of the liquid drink that you suggest?
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 04:16 pm
I want to believe in the ether.

Hey kernosabe, I came up with some numbers here http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263849#msg1263849

Please give us your numbers for your ether magnetically induced force field  :)

You also get 48 Hamster-Hours to provide those numbers.  If you do you get a drink.

Ok.  How about Numbers 6:24-26?

Sadly, you ask for that which I cannot provide.  I want to believe in the ether, but it is not a fundamental need for me.  I guess it is my intuition which suggests that information can travel instantaneously, and also that there ought to be an instantaneous explanation for inertia.

The mental image of a spaceship using an "invisible" propeller shaped force field pushing against the "invisible" ether is an intriguing one for me.

You had mentioned considering a 24 hour fluctuation in the "Force" as a means of determining the direction of the "inertial wind".  Might I also throw out this paper, regarding the idea that there is change in the gravitational constant?

What is the nature of the liquid drink that you suggest?

Hey kernosabe!

What do you know, the paper is from my alma mater , and the pendulum is a classical Cavendish type pendulum (just as used by Brito, Marini and Galian to nullify the Woodward MLT drive and used in classical experiments of inverse square law gravitation and measurement of the Casimir force) instead of that nonlinearly-coupled magnetically damped inverse pendulum.

Again: #1 priority is to replicate the Eagleworks experiments at John Hopkins using their Cavendish.

Good ol' Cavendish http://en.wikipedia.org/wiki/Cavendish_experiment  performed his experiment in 1797, 217 years ago, and he was capable of measuring a force of  0.174 microNewtons, less than 1% of the reported thrusts at Eagleworks.   

By comparison, the admitted magnetic interaction in the magnetically damped inverted pendulum at Eagleworks was ~10 microNewtons (and I think it is substantially more because of nonlinear coupling not taken into account). That's ~55 times greater than Cavendish.

Go back to the classics  :)

Oh, and the drink is a Martini

Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/29/2014 04:28 pm
Oh, and the drink is a Martini.

Huh.  Shaken or stirred?

There's also this paper:
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 04:37 pm
Oh, and the drink is a Martini.

Huh.  Shaken or stirred?

There's also this paper:

But what does the latest astrophysical data show?  My (limited) knowledge is that G hasn't changed appreciably with time...
Don't know about its claimed small anisotropy.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/29/2014 04:43 pm
Dunno what today's value is, but the point of the paper is that our increasingly accurate measurements are not honing into a limiting value, but that the value is changing, and not in a predictable dierection, even if by only a small amount.  If G is changing, then why and how become important questions.  And if why and how can be answered, then one can ask if it can be controlled.  Just hare braining on the ramifications of understanding gravity and inertia, and it's applicability to a propellantless drive.
Title: Re: EM Drive Developments
Post by: cuddihy on 09/29/2014 04:45 pm

Being unable to build a consistent and reproducible experiment in 17 years is completely compatible with "no true effect is possible" or "true effect is possible but were never encountered yet", and less and less compatible with "some true effect was witnessed at some point". Regardless of priors and theories.


you missed "or true effect has been encountered and demonstrated in numerous trials, but required conditions not understood sufficintly to make it reliable and consistent," which is also compatible with the history. Otherwise, I agree.
Quote

Quote
The one thing that changes the dynamic is if you can increase the thrust/power to the level where spurious sources of thrust are differentiated by the power level. The larger the thrust being measured, the easier it is to figure out the source.

So even if the theory is wrong, after so many years of chasing something uncertain, and if you're convinced either by the underlying theory or previous results, surely it makes sense to keep trying to increase the thrust while only slowly chipping away at the spurious potential sources.

If "my" theory is correct (true effect is impossible) : the thrust is spurious, trying to augment it is trying to augment a spurious effect. At some point it could appear clearly as spurious because it was augmented. Ok, I give you that.
Ok, so you accept the main point I made. Good. Sure took a lot of words to say that though.

Quote

But it is also possible that in this antagonistic interplay between lowering the effects one recognize as spurious and augmenting the effects believed to be true (still spurious, but not recognized as such), and changing constantly from set-ups, devices, experimental conditions... one is just keeping on the level of confusion needed to maintain an illusion of true effect and progress when there is none.

That is an entirely unjustified characterization that belongs more to charlatanery like Rossi's ecat or Blacklight power. Neither Woodward nor White's open efforts deserve that.
Quote

So even if augmenting the thrust could be a way to find and understand it as a spurious effect (real progress) my take is that it is not the best way. Focus should be on a good appropriate balance and isolating the device, first, like Brito et al. Then if you have a positive result, this is a clean result, apply for Nobel. Else, null result (like Brito et al), this is also a clean result. Then try another theory/design. Don't expect better thrusting as any guideline for the new design as this is all or nothing, either you have a real effect (and improvement can come later, after the Nobel) or you have no real effect (and improving thrust is pointless). So every new design is a blank page.

Consider our medieval scientists, after some time at becoming expert at hoping on a given scale to optimise the averaged apparent weight they build a new and better scale. The experience gained in hoping to fool a mechanical scale is still useful to get non null result with the new model of scale, but not as good. Disparate results... but still non null, and still possible to refine the aptitude to fool this new kind of scale... (also at lower levels). Better and better scales, lower and lower effects, but still non null, and still possible to "improve" on any given scale. At some point a monk remarks that blowing downward has a very small but significant and continuous effect on apparent weight. That would be a real effect (for the goal of flying/hovering). What was gained in terms of progress by all those years of hoping when discovering this new real effect ? Better scales, I grant you that, but for the real effect it's like starting from a blank page.

Nice strawman. But this proposed path is exactly what these efforts have been doing! And each time a particular spurious source is ruled out, critics have found a new hobby horse to criticize. So after years of this, at some point you can only address the forest of potential sources, as I said, by attempting to increase the force. If you fail to do so, that is another brick in the wall against accepting the theory. So it's best for all parties involved, including the critics, yes?
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 05:36 pm
... after years of this, at some point you can only address the forest of potential sources, as I said, by attempting to increase the force. If you fail to do so, that is another brick in the wall against accepting the theory. So it's best for all parties involved, including the critics, yes?
@cuddihy

Yes, attempting to increase the thrust force is certainly best for all parties involved, the inventors and their backers as well as those that question whether the thrust forces are real (and if so, whether they are subject to be scaled up to enable the 269 days trip to Titan and Enceladus described by Eagleworks). 

With all the problems I see in measuring the thrust in a magnetically damped inverted pendulum like the one at Eagleworks, I certainly think that it would make things much easier if the thrust forces were increased.  I understand that Eagleworks is trying to do that with their next Frustum microwave device.

If the thrust forces were increased to be comparable to the thrust force of an ion rocket there are so many places where these devices could be tested...

Until that (increasing the thrust force) happens the #1 priority should be to test using the Cavendish at John Hopkins University (for the reasons I posted).
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/29/2014 06:23 pm
Intresting:

Axion Dark Matter Experiments
G.Rybka Talk at the Workshop on Frontiers of New Physics: Colliders and Beyond in Trieste, Italy (2014)

Oops :Check slides 29/31 and 28/31 on the inclusion of dielectrics  (no time for chatting just now)
Title: Re: EM Drive Developments
Post by: Ron Stahl on 09/29/2014 06:29 pm
If the experiments cannot be easily reproduced by other scientists at other locations, they cannot  be considered part of the scientific progress.
This is certainly not true.  First of all we'll never be agreed with what is "easy" but even should we under special circumstances, "ease" of experiment has never been one of the criteria used to judge experimental science.

And I'll give an example.  Reading quickly down from last week's notes, I see again the criteria that the experimental setup ought to be "self-contained".  I'd just note i coined that phrase years ago, probably in this forum when looking at the issue of the power supply.  The trouble is, this criteria, while it removes general doubts, creates anything but "ease" of experiment.

In the case of Woodward's work, he has correctly avoided self-contained power systems for good reasons.  First of all, there are plenty of scientific controls and protocols that can establish whether one has a spurious contribution from the power supply, and these controls are part of the foundation for Woodward's work, so he really doesn't need a self-contained apparatus and this is normally requested by people who are not yet familiar enough with the setup to make an educated appraisal of it.  And I'll note, there is no onus on the experimenter to provide for "ease' of judgement.  The onus is for good science.

So why does Woodward feed power to the thruster through the galinstan contacts rather than put a battery aboard?  Some of this is simple economics and some is a necessary part of the scientific controls applied.  In short, it would be extremely expensive to have a self-contained apparatus that can provide controls such as variable voltage to the thruster, and clearly demonstrating thrust as a function of voltage is one key element that has to be provided in these tests.  If one were to go with a self-contained setup, one would necessarily have to be able to vary voltage, the phase between the 1w and 2w components of the signal, etc., and to control such things with an RF control signal and receiver inside the vacuum chamber, where high voltage is involved, is certainly not ever going to be "easy" nor is it within Woodward's budget.  So he's doing what he can with the resources he has and when one avails themselves to all the details of the setup, one can see the concerns about power into the balance arm have indeed been dealt with in other ways.

This said, let me note that I am still a proponent of a self-contained demonstration but for other reasons.  The fact is, we need to address the veracity issue here.  There's no money for real replication, so what to do?  Well, what you do is look for independent validation without funds for replication which is to say, you design a kit that can be moved from one lab to the next and using each lab's own protocols, test a single device (or small number of identical devices.)  In order to move the whole kit, you have to have serious portability, so you are looking at a much more expensive experiment than you would otherwise.  You want to build the thruster and power system, such that they can be put on half a dozen different balances, without costing each of these other labs so much that this solution is out of the realm of possibility.

And I would just note to you, these very practical concerns about who pays for what very often determine what gets tested and what does not.  Woodward cannot pay for a replication and have that work provide the necessary independence such that the replication would generate sufficient veracity.  What is required therefore is to put the cash into a kit that can be used to validate at various different labs, and this does seem to me requires a self-contained setup.  I'm all for this, but this requires serious funding.  It's not a hobby project.  It's near a million dollars just to miniaturize the power system for this, but then you hope to get your validation studies for free.
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 06:51 pm
Intresting:

Axion Dark Matter Experiments
G.Rybka Talk at the Workshop on Frontiers of New Physics: Colliders and Beyond in Trieste, Italy (2014)

Oops :Check slides 29/31 and 28/31 on the inclusion of dielectrics  (no time for chatting just now)

I had not yet seen that presentation  "Axion Dark Matter Experiments  G.Rybka Talk at the Workshop on Frontiers of New Physics: Colliders and Beyond in Trieste, Italy (2014)", thanks for the tip  :),  Here is the link to that presentation:

http://cdsagenda5.ictp.it//askArchive.php?categ=a13203&id=a13203s13t10&ifd=48107&nm=Rybka.pdf&down=1&type=Presentation_Rybka

Here I attach slides 27, 28 and 29

Notice how the expected axion coupling increases with expected axion mass.

Look at the magnitude of those Q's  (10^6)

They now report testing at much higher frequencies as well: 15 to 120 GHz range. They were previously testing in the 0.81 to 0.86 GHz range, see:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263849#msg1263849

Eagleworks run the Frustrum at 1.94 GHz  (twice the value of what ADMX run before, but less than 7 times what they report now in this slide).

They are also running with a lower magnetic field (3 T and 6 T instead of the previously reported >7 T)

They are spacing the dielectric resonators by 1/2 the wavelength in the waveguide.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/29/2014 07:23 pm
If the experiments cannot be easily reproduced at all by other scientists at other locations, they cannot  be considered part of the scientific progress.

This is certainly not true.

Fixed that for Rodal.  Is Rodal's statement now true?
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 07:28 pm
Slides 30 and 31 from the presentation  "Axion Dark Matter Experiments  G.Rybka Talk at the Workshop on Frontiers of New Physics: Colliders and Beyond in Trieste, Italy (2014)".  Here is the link to that presentation:

http://cdsagenda5.ictp.it//askArchive.php?categ=a13203&id=a13203s13t10&ifd=48107&nm=Rybka.pdf&down=1&type=Presentation_Rybka

__________________

This belongs immediately following my presentation of the other slides, before John's impromptu correction  :)
Title: Re: EM Drive Developments
Post by: Ron Stahl on 09/29/2014 07:28 pm
If the experiments cannot be easily reproduced at all by other scientists at other locations, they cannot  be considered part of the scientific progress.

This is certainly not true.

Fixed that for Rodal.  Is Rodal's statement now true?
Yes.  Close enough though "all" seems to open a crazy box of nonsense.  Does the good Doctor pay you to edit his posts online?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 07:35 pm
If the experiments cannot be easily reproduced at all by other scientists at other locations, they cannot  be considered part of the scientific progress.

This is certainly not true.

Fixed that for Rodal.  Is Rodal's statement now true?
What about the discovery of the Higgs boson at CERN?
Can this be replicated at a different location?
No. It cannot presently and therefore cannot be considered part of scientific progress according to Rodal.
Does that make Rodal's statement true of false?
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 07:38 pm
If the experiments cannot be easily reproduced at all by other scientists at other locations, they cannot  be considered part of the scientific progress.

This is certainly not true.

Fixed that for Rodal.  Is Rodal's statement now true?
What about the discovery of the Higgs boson at CERN?
Can this be replicated at a different location?
No. It cannot presently and therefore cannot be considered part of scientific progress according to Rodal.
Does that make Rodal's statement true of false?
And why can't it be replicated? is it because of somebody's "personal touch" ? NO
Is it because of claimed NDA's NO
Is it because the testing protocol is not scientifically provided NO

It is because there is no comparable facility to CERN

Do you think that Woodward's or Eagleworks facilities compare in any way to CERN ? NO. 
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 07:40 pm
If the experiments cannot be easily reproduced at all by other scientists at other locations, they cannot  be considered part of the scientific progress.

This is certainly not true.

Fixed that for Rodal.  Is Rodal's statement now true?
What about the discovery of the Higgs boson at CERN?
Can this be replicated at a different location?
No. It cannot presently and therefore cannot be considered part of scientific progress according to Rodal.
Does that make Rodal's statement true of false?
And why can't it be replicated? is it because of somebody's "personal touch" ? NO
Is it because of claimed NDA's NO
Is it because the testing protocol is not scientifically provided NO

It is because there is no comparable facility to CERN

Do you think that Woodward's or Eagleworks facilities compare in any way to CERN ? NO.
Maybe you should update your statement about scientific progress then, rather than getting angry.
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 07:44 pm
Quote
What about the discovery of the Higgs boson at CERN?
Can this be replicated at a different location?
No. It cannot presently and therefore cannot be considered part of scientific progress according to Rodal.
Does that make Rodal's statement true of false?
And why can't it be replicated? is it because of somebody's "personal touch" ? NO
Is it because of claimed NDA's NO
Is it because the testing protocol is not scientifically provided NO

It is because there is no comparable facility to CERN

Do you think that Woodward's or Eagleworks facilities compare in any way to CERN ? NO.
Maybe you should update your statement about scientific progress then, rather than getting angry.
I did not put an angry face, on the contrary, I'm smiling  :)

I'm glad that you brought up CERN as a comparison, as there is a huge difference to be noticed (besides the scale of CERN):

The experiments at CERN are being performed with the simultaneous cooperation of hundreds of scientists from different institutions across the world.

The issue of "scientific acceptance" is handled at CERN by this worldwide involvement in their experiments. There is all kinds of double-checking and replication (at CERN  itself) of experiments before the data is accepted.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/29/2014 07:51 pm
The LHC and the discovery of the Higgs Boson also relied on tens of trillions of data points. Before they started looking for new science, they made sure they rediscovered every other standard model particle to verify that their instruments were accurately calibrated. The discovery of the Higgs Boson relied on the legacy of many other scientific instruments, rather than just the Large Hadron Collider's detectors. Even then, it's accepted scientific literature, in large part, because reproduction steps are available to anyone willing to build another large particle accelerator.

The secret to the LHC's success is a long history of collaboration and openness about their scientific results. Secrecy is the enemy of progress.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 07:52 pm
If the experiments cannot be easily reproduced at all by other scientists at other locations, they cannot  be considered part of the scientific progress.

This is certainly not true.

Fixed that for Rodal.  Is Rodal's statement now true?
What about the discovery of the Higgs boson at CERN?
Can this be replicated at a different location?
No. It cannot presently and therefore cannot be considered part of scientific progress according to Rodal.
Does that make Rodal's statement true of false?
And why can't it be replicated? is it because of somebody's "personal touch" ? NO
Is it because of claimed NDA's NO
Is it because the testing protocol is not scientifically provided NO

It is because there is no comparable facility to CERN

Do you think that Woodward's or Eagleworks facilities compare in any way to CERN ? NO.
Maybe you should update your statement about scientific progress then, rather than getting angry.
I did not put an angry face, on the contrary, I'm smiling  :)

I'm glad that you brought up CERN as a comparison, as there is a huge difference to be noticed (besides the scale of CERN):

The experiments at CERN are being performed with the simultaneous cooperations of hundreds of scientists from across the world.  I know of several from MIT and other world universities.

I guessed you were angry because of the shouted 'NO's
Quote
Do you think that Woodward's or Eagleworks facilities compare in any way to CERN ? NO.
For sure the scale of those facilities doesn't match CERN.
But in terms of scientific integrity I have no reason to doubt either. It seems also that Woodward et al are also cooperating with other interested scientists and institutions.
My point is that your previous statement about scientific progress is NOT true for CERN and therefore is false.
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 07:54 pm

I hereby update my poorly worded previous statement  :):

If the experiments cannot be reproduced by other scientists, they cannot  be considered part of the scientific progress.

This takes care of CERN, as there are hundreds of independent scientists involved from academic institutions from across the world.


Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 07:59 pm

I hereby update my poorly worded previous statement  :):

If the experiments cannot be reproduced by other scientists, they cannot  be considered part of the scientific progress.

This takes care of CERN, as there are hundreds of scientists involved from across academic institutions from across the world.
Ah! That's better.
Thank you Dr. Rodal.
So how does your updated statement relate to the matter in hand?
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 08:02 pm

I hereby update my poorly worded previous statement  :):

If the experiments cannot be reproduced by other scientists, they cannot  be considered part of the scientific progress.

This takes care of CERN, as there are hundreds of scientists involved from across academic institutions from across the world.
Ah! That's better.
Thank you Dr. Rodal.
So how does your updated statement relate to the matter in hand?

I would rather discuss numbers, possible other effects (look at my recent postings on Axion dark matter) and engineering calculations than spend more time on this don't you think  :)

Not interested in a thread on definitions of what is and what is not science.  Maybe we should do that on a thread on Karl Poper  :)

Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 08:04 pm

I hereby update my poorly worded previous statement  :):

If the experiments cannot be reproduced by other scientists, they cannot  be considered part of the scientific progress.

This takes care of CERN, as there are hundreds of scientists involved from across academic institutions from across the world.
Ah! That's better.
Thank you Dr. Rodal.
So how does your updated statement relate to the matter in hand?

I would rather discuss numbers, possible other effects (look at my recent postings on Axion dark matter) and engineering calculations than spend more time on this don't you think  :)

Not interested in a thread on definitions of what is and what is not science.  Maybe we should do that on a thread on Karl Poper  :)
Agreed.
Thanks.
I'll have something more on-topic soon.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 09/29/2014 08:19 pm

I hereby update my poorly worded previous statement  :):

If the experiments cannot be reproduced by other scientists, they cannot  be considered part of the scientific progress.

This takes care of CERN, as there are hundreds of scientists involved from across academic institutions from across the world.
Ah! That's better.
Thank you Dr. Rodal.
So how does your updated statement relate to the matter in hand?

I would rather discuss numbers, possible other effects (look at my recent postings on Axion dark matter) and engineering calculations than spend more time on this don't you think  :)

Not interested in a thread on definitions of what is and what is not science.  Maybe we should do that on a thread on Karl Poper  :)
I appreciate this too, and would note that if one were looking for that sort of debate, one could quibble about what you mean by "progress" instead of "process".  And I would note to you, there is no universally agreed upon definition of what good scientific process looks like.  the real point--the one you made well--is that for it to be considered science, one needs to avail themselves to reproducibility or some other form of validation to meet the veracity requirement.  If you want your work to be accepted by the broader science community, you want to tell that community enough that they can take it upon themselves to reproduce your work.  And just noting, this is what Woodward has always done.  Anyone/everyone is invited to his lab at Cal Fullerton.  He allows almost anyone onto his weekly distribution, and invites everyone to offer their insights how to make the process as open and transparent as possible.  Woodward isn't bothering with NDA's and not worried about patents.  He's just doing proof of science.  It's the people doing proof of technology, who don't have patents (like SpaceX) who need to be worried about things like NDA's.  Why Dr. White is supposedly under NDA is beyond me.
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 08:41 pm
Notice again the importance of imposing a strong (several Tesla) external magnetic field to transfer axion field energy to the microwave cavity, using the Inverse Primakov conversion (http://en.wikipedia.org/wiki/Primakoff_effect).

The Eagleworks Cannae and Frustrum experiments are missing the ADMX experiment 3 T to 7.6 T strong magnetic field.  The only magnetic field in the Eagleworks  experiments is the one produced by the three neodymium (NdFeB Grade N42) block magnets, which is there only by chance ( to dampen the swinging and torsional oscillations of the inverted pendulum).  The magnetic damper is located about a foot away from the tested microwave device (Cannae or Frustum). For comparison, the magnetic field intensity at the surface of a neodymium magnet is 1.25 T

So, perhaps Eagleworks should explore what difference it makes to place additional neodymium magnets surrounding the tested device to impose the required external magnetic field for axion field energy conversion :)
If there was any transfer (which I doubt very much) of axion field energy in the previous Eagleworks experiments, there should be orders of magnitude more with the application of a 1.25 T magnetic field surrounding the microwave cavity.

Of course the (admitted by Eagleworks) coupling of the field from (the magnetic) damper with the power (cable's magnetic) field is an issue with the inverted pendulum.  The inverted pendulum issue could be avoided by using an oil-damped Cavendish arrangement (as the one at John Hopkins ?) and as was used by Brito, Marini and Galian.


Status of the Axion Dark Matter Experiment (ADMX)  L. Rosenberg Talk at the Patras Workshop at CERN (2014)
http://indico.cern.ch/event/300768/session/0/contribution/30/material/slides/1.pdf
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 09:36 pm
More from "Axion Dark Matter Experiments  G.Rybka Talk at the Workshop on Frontiers of New Physics: Colliders and Beyond in Trieste, Italy (2014)",  link to that presentation:

http://cdsagenda5.ictp.it//askArchive.php?categ=a13203&id=a13203s13t10&ifd=48107&nm=Rybka.pdf&down=1&type=Presentation_Rybka
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 09:52 pm
Perhaps there should have been an effect under the >7 T mag fields at CERN. Maybe the whole machine is trying to take-off?! ;)
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 10:03 pm
Perhaps there should have been an effect under the >7 T mag fields at CERN. Maybe the whole machine is trying to take-off?! ;)

We should call them to tell them they should also be measuring thrust forces  :D
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 10:07 pm
Perhaps there should have been an effect under the >7 T mag fields at CERN. Maybe the whole machine is trying to take-off?! ;)

We should call them to tell them they should also be measuring thrust forces  :D
They knew of this effect when they designed the accelerator. Why do you think it was built underground.
;)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 10:10 pm
Seriously. No Axions discovered at CERN == No Axions with our devices.
Is this a reasonable stance?
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 10:22 pm
Seriously. No Axions discovered at CERN == No Axions with our devices.
Is this a reasonable stance?
You mean by the CERN Axion Solar Telescope ?

CERN with their Axion Solar Telescope have been looking at a completely different axion mass than the experiments I have been discussing at the University of Washington. So, no, I don't think that CERN not finding axions at that completely different mass invalidates axions interaction for these microwave devices.

The University of Washington ADMX search (for at least one year) is definitely concerning, unless somebody can show that measuring microNewton thrust is somewhat more sensitive that identifying photons, as ADMX is trying to do.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 10:28 pm
Seriously. No Axions discovered at CERN == No Axions with our devices.
Is this a reasonable stance?
You mean by the CERN Axion Solar Telescope ?

CERN with their Axion Solar Telescope have been looking at a completely different axion mass than the experiments I have been discussing at the University of Washington. So, no, I don't think that CERN not finding axions at that completely different mass invalidates axions interaction for these microwave devices.

The University of Washington ADMX search (for at least one year) is definitely concerning, unless somebody can show that measuring microNewton thrust is somewhat more sensitive that identifying photons, as ADMX is trying to do.
I think all these experiments are looking for traces of things not predicted by theory.
They all have very small signal/noise ratios.
Just like Woodward et al.
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 10:32 pm
Seriously. No Axions discovered at CERN == No Axions with our devices.
Is this a reasonable stance?
You mean by the CERN Axion Solar Telescope ?

CERN with their Axion Solar Telescope have been looking at a completely different axion mass than the experiments I have been discussing at the University of Washington. So, no, I don't think that CERN not finding axions at that completely different mass invalidates axions interaction for these microwave devices.

The University of Washington ADMX search (for at least one year) is definitely concerning, unless somebody can show that measuring microNewton thrust is somewhat more sensitive that identifying photons, as ADMX is trying to do.
I think all these experiments are looking for traces of things not predicted by theory.
They all have very small signal/noise ratios.
Just like Woodward et al.

I don't understand why you brought up the search for Axions at CERN's telescope as an example.  CERN's telescope is looking at masses that differ by several orders of magnitude from the axion mass that you would find interacting in a microwave cavity.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/29/2014 10:33 pm
The LHC and the discovery of the Higgs Boson also relied on tens of trillions of data points. Before they started looking for new science, they made sure they rediscovered every other standard model particle to verify that their instruments were accurately calibrated. The discovery of the Higgs Boson relied on the legacy of many other scientific instruments, rather than just the Large Hadron Collider's detectors. Even then, it's accepted scientific literature, in large part, because reproduction steps are available to anyone willing to build another large particle accelerator.

The secret to the LHC's success is a long history of collaboration and openness about their scientific results. Secrecy is the enemy of progress.


another secret is the huge amount of money they have. Imagine a single guy trying to discover the Higgs Boson with an apparatus created with his own money. And other labs not interested in replicating the experiments unless you give yourself the machine you built (and they just use other methods to test).

and your signals are not that strong. You see only hints of the Higgs Boson in your machine.
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/29/2014 10:38 pm
The LHC and the discovery of the Higgs Boson also relied on tens of trillions of data points. Before they started looking for new science, they made sure they rediscovered every other standard model particle to verify that their instruments were accurately calibrated. The discovery of the Higgs Boson relied on the legacy of many other scientific instruments, rather than just the Large Hadron Collider's detectors. Even then, it's accepted scientific literature, in large part, because reproduction steps are available to anyone willing to build another large particle accelerator.

The secret to the LHC's success is a long history of collaboration and openness about their scientific results. Secrecy is the enemy of progress.


another secret is the huge amount of money they have. Imagine a single guy trying to discover the Higgs Boson with an apparatus created with his own money. And other labs not interested in replicating the experiments unless you give yourself the machine you built (and they just use other methods to test).

and your signals are not that strong. You see only hints of the Higgs Boson in your machine.

When you look at it this way, it looks even less okay for EM drive proponents to withhold data from the scientific research community. Major research institutions have the resources to find more signal amidst noise than hobbyists could ever hope for. EM drive researchers should be reaching out to the broader scientific community, to give scientists, researchers, and engineers some evidence, and good faith, that there is something worth investigating in that direction.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 09/29/2014 10:42 pm
Seriously. No Axions discovered at CERN == No Axions with our devices.
Is this a reasonable stance?
You mean by the CERN Axion Solar Telescope ?

CERN with their Axion Solar Telescope have been looking at a completely different axion mass than the experiments I have been discussing at the University of Washington. So, no, I don't think that CERN not finding axions at that completely different mass invalidates axions interaction for these microwave devices.

The University of Washington ADMX search (for at least one year) is definitely concerning, unless somebody can show that measuring microNewton thrust is somewhat more sensitive that identifying photons, as ADMX is trying to do.
I think all these experiments are looking for traces of things not predicted by theory.
They all have very small signal/noise ratios.
Just like Woodward et al.

I don't understand why you brought up the search for Axions at CERN's telescope as an example.  CERN's telescope is looking at masses that differ by several orders of magnitude from the axion mass that you would find interacting in a microwave cavity.
That is your assertion. Who knows the existence or interaction cross-sections of the proposed axons? They must be different in many ways otherwise we would already be sure of their existence.
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 11:37 pm
Seriously. No Axions discovered at CERN == No Axions with our devices.
Is this a reasonable stance?
You mean by the CERN Axion Solar Telescope ?

CERN with their Axion Solar Telescope have been looking at a completely different axion mass than the experiments I have been discussing at the University of Washington. So, no, I don't think that CERN not finding axions at that completely different mass invalidates axions interaction for these microwave devices.

The University of Washington ADMX search (for at least one year) is definitely concerning, unless somebody can show that measuring microNewton thrust is somewhat more sensitive that identifying photons, as ADMX is trying to do.
I think all these experiments are looking for traces of things not predicted by theory.
They all have very small signal/noise ratios.
Just like Woodward et al.

I don't understand why you brought up the search for Axions at CERN's telescope as an example.  CERN's telescope is looking at masses that differ by several orders of magnitude from the axion mass that you would find interacting in a microwave cavity.
That is your assertion. Who knows the existence or interaction cross-sections of the proposed axons? They must be different in many ways otherwise we would already be sure of their existence.
What we know very well is the CERN's (X ray) telescope instrument and Axion experiment.   

The following plot shows the axion-photon coupling versus axion mass plane. The limit achieved by the CAST experiment (combined result of the CAST phase I and 4He part of phase II) is compared with constraints obtained from the Tokyo helioscope and HB stars. The yellow band represents typical theoretical models.

The intersection between the Axion theoretical models and CERN's (X ray) telescope search  is in the mass range ~ >0.01 ev to 1 ev range.

This mass range is several orders of magnitude higher than the (microwave) ADMX experiment searching for Axion masses in the 10^(-6)ev to 10^(-5) ev range.

You cannot find an axion in the yellow band with a mass of 10^(-6)ev if you are capable of searching only in the yellow band (CERN telescope range of) >0.01 ev to 1 ev  range.


http://cast.web.cern.ch/CAST/CAST.php

Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/29/2014 11:51 pm
If the experiments cannot be easily reproduced at all by other scientists at other locations, they cannot  be considered part of the scientific progress.

This is certainly not true.

Fixed that for Rodal.  Is Rodal's statement now true?
Yes.  Close enough though "all" seems to open a crazy box of nonsense.  Does the good Doctor pay you to edit his posts online?

Nahhhh.  I can't even get him to buy me a martini.  He sends me a picture of a virtual one.  You call that payment?  Sheesh.
Title: Re: EM Drive Developments
Post by: Rodal on 09/29/2014 11:58 pm
If the experiments cannot be easily reproduced at all by other scientists at other locations, they cannot  be considered part of the scientific progress.

This is certainly not true.

Fixed that for Rodal.  Is Rodal's statement now true?
Yes.  Close enough though "all" seems to open a crazy box of nonsense.  Does the good Doctor pay you to edit his posts online?

Nahhhh.  I can't even get him to buy me a martini.  He sends me a picture of a virtual one.  You call that payment?  Sheesh.
Rejoice and be glad, because great is your reward in heaven
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/30/2014 12:07 am
Another secret is the huge amount of money they have. Imagine a single guy trying to discover the Higgs Boson with an apparatus created with his own money. And other labs not interested in replicating the experiments unless you give yourself the machine you built (and they just use other methods to test).

And your signals are not that strong. You see only hints of the Higgs Boson in your machine.

And imagine that you don't seek grant money, or DARPA money, or NASA money, or a private investor with deep pockets.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/30/2014 12:11 am
Rejoice and be glad, because great is your reward in heaven...

Yeah sure.  That's what they told Osama Bin Laden:

When OBL died, George Washington met him at the Pearly Gates. He slapped him across the face and yelled, "How dare you try to destroy the Nation I helped conceive?"

Patrick Henry approached, punched him in the nose and shouted, "You wanted to end our liberties but you failed."

James Madison followed, kicked him in the groin and said, "This is why I allowed our government to provide for the common defense!"

Thomas Jefferson was next, beat Osama with a long cane and snarled, "It was evil men like you who inspired me to write the Declaration of Independence. "

The beatings and thrashings continued as George Mason, James Monroe and 66 other early Americans unleashed their anger on the radical, socialist, leader.

As Osama lay bleeding and in pain, an Angel appeared. Osama wept and Said, "This is not what you promised me."

The Angel replied, "I told you there would be 72 VIRGINIANS waiting for you in Heaven. What did you think I said?"
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 12:39 am
Sheeesh.  I thought that this was the EM Drive Developments thread.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/30/2014 01:13 am
Sheeesh Hardy har har.  I thought that this was the EM Drive Developments thread.

Fixed that for ya.  But you're right.  Back to regular programming.

[Got more where that one came from.  Just sayin'.]
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 01:20 am
Sheeesh Hardy har har.  I thought that this was the EM Drive Developments thread.

Fixed that for ya.  But you're right.  Back to regular programming.

[Got more where that one came from.  Just sayin'.]
Hardy har har?  Back to regular programming?  You took the wrong turn?

http://www.youtube.com/watch?v=VPo9UJErdbA
Title: Re: EM Drive Developments
Post by: ThinkerX on 09/30/2014 01:29 am
Quote
Here I attach slides 27, 28 and 29

Notice how the expected axion coupling increases with expected axion mass.

Look at the magnitude of those Q's  (10^6)

They now report testing at much higher frequencies as well: 15 to 120 GHz range. They were previously testing in the 0.81 to 0.86 GHz range, see:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263849#msg1263849

Eagleworks run the Frustrum at 1.94 GHz  (twice the value of what ADMX run before, but less than 7 times what they report now in this slide).

They are also running with a lower magnetic field (3 T and 6 T instead of the previously reported >7 T)

They are spacing the dielectric resonators by 1/2 the wavelength in the waveguide.

Ok...if I am following this correctly, then the spec's for the axiom experiment in Italy are now much closer to being in line with spec's for the Eagleworks 'propellentless drive'...apart from the missing (?) electromagnetic field?

That said, in the paper that set off this thread, the Eagleworks team did seem to think they'd be able to manufacture a much more powerful thruster for the next set of tests.  Assuming they get anywhere near the hoped for results with the new device, would this invalidate the axiom angle? 
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/30/2014 01:43 am
Nope, but the axiom angle might be related to any frequency difference between 2 photons.

Hmmm, notice the nonlinear waveform in slide 28 ?

Reminds me that dielectric layers can be used to isolate the electric and magnetic interactions (as in the dielectric/metal/dielectric optical filter).  Maybe in the COMSOL model of the Sawyer resonator ?

Now there's a thought, if the axion is it's own antiparticle, perhaps the decay is so weak in a simple resonator because the 2 photons are out of phase.
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 02:17 am
Nope, but the axiom angle might be related to any frequency difference between 2 photons.

Hmmm, notice the nonlinear waveform in slide 28 ?

ADMX (Washington Univ.) axion (dark matter) experiment

They have several dielectric resonators strategically located such that they are placed at the valleys of the waveform in the waveguide:

You are right, the nonlinearity (straighter, sharp waveform negative peaks) is inside the dielectric-blocks.

The waveform in the cavity regions between the dielectric-blocks has a harmonic shape, by comparison.

Also observe that the field in their waveguide cavities (between the dielectric blocks) reaches high resonance.

______________________________________________________________

NASA Eagleworks Tapered-Cavity Frustum

It has a single disc dielectric resonator with an inner hole.

By comparison, look at the field inside the Eagleworks frustum ("tapered cavity"):practically nothing is going on in the cavity itself (it is all uniform blue: very low values, practically no gradient) and only the PTFE ("Teflon") dielectric resonator reaches (red)  high values and it has a high gradient.
Title: Re: EM Drive Developments
Post by: aceshigh on 09/30/2014 02:27 am
The LHC and the discovery of the Higgs Boson also relied on tens of trillions of data points. Before they started looking for new science, they made sure they rediscovered every other standard model particle to verify that their instruments were accurately calibrated. The discovery of the Higgs Boson relied on the legacy of many other scientific instruments, rather than just the Large Hadron Collider's detectors. Even then, it's accepted scientific literature, in large part, because reproduction steps are available to anyone willing to build another large particle accelerator.

The secret to the LHC's success is a long history of collaboration and openness about their scientific results. Secrecy is the enemy of progress.


another secret is the huge amount of money they have. Imagine a single guy trying to discover the Higgs Boson with an apparatus created with his own money. And other labs not interested in replicating the experiments unless you give yourself the machine you built (and they just use other methods to test).

and your signals are not that strong. You see only hints of the Higgs Boson in your machine.

When you look at it this way, it looks even less okay for EM drive proponents to withhold data from the scientific research community. Major research institutions have the resources to find more signal amidst noise than hobbyists could ever hope for. EM drive researchers should be reaching out to the broader scientific community, to give scientists, researchers, and engineers some evidence, and good faith, that there is something worth investigating in that direction.

that´s naive to the extreme.

we all know this is the kind of physics subject that won´t be touched with a ten foot pole, if not by scientists, by the institutions that grant research money.

the reaction of most will be the same seen here in most of the thread. Like by GoatGuy. By doing arithmetic, it clearly violates several physics laws and thus is impossible and in the realm of the crackpots.

and will atribute the noise to experiments faults.

it´s a chicken and egg question (just rethoric here, from a scientific point of view the egg came first), as most people here were SAYING that Woodward and others should do a test device to test on space, like if that was cheap, and THEN people would accept it was more than noise and invest in tests of their own.


and btw, are you talking about Dr Woodward or about Dr White here? Because Dr Woodward doesn´t hide behind anything. He is quite open. So right there your theory fails, because there aren´t really many people WITH MONEY wanting to invest in testing it.

I think it can be noise or not. I will just sit and wait, but I won´t deduce anything from where there is not enough info to make a good deduction.
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 02:34 am
NASA Eagleworks could imitate the design of ADMX waveguide with strategically located dielectric resonators to enhance coupling.  ADMX has reached much higher Q's than Eagleworks.
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 03:03 am
.....

Now there's a thought, if the axion is it's own antiparticle, perhaps the decay is so weak in a simple resonator because the 2 photons are out of phase.

Axion, Photons in terms of “Particles” and “Antiparticles”
E.Guendelman,
Ben Gurion U. , Israel,
4th Patras Conference, DESY, 06/ 21/08

http://axion-wimp2008.desy.de/e30/e247/talk-21-guendelman.pdf

The Scalar QED Picture and its consequences
1. gB(y,z) couples to the “density of charge” like an external
electric potential would do it.
2. The axion is a symmetric combination of particle
antiparticle, while the photon is the antisymmetric
combination.
3.If the direction of initial beam of photons or axions is
perpendicular to the magnetic field and to the gradient of
the magnetic field, we obtain in this case beam splitting
(new result).
4. Known results for the cases where the direction of the
beam is orthogonal to the magnetic field but parallel to
the magnetic field gradient can be reproduced easily.
Title: Re: EM Drive Developments
Post by: raketa on 09/30/2014 03:19 am
I was suggesting first to proof/disproof in space, because lot of people thinking this is good idea, why we didn't try to make it happen.
I am putting my money where  my mouth is ready to pledge initial $1000 for this project.
1/Could we contact professor Dr Woodward if he will be interesting to participate and build his apparatus for space environment.
2/We have to find who will do crowdsourcing for us. Does anybody have experience or could recommend it somebody who has good reputation.
3/Easiest and cheapest in my opinion will be to install apparatus in trunk of Dragon. And test it after departure from ISS. We will have power, probably not communication.
I think it will be possible to get Elon  approval if we  him show potential of this project to accommodate our device on trunk and put hard switch that will be enabled after Dragon depart from ISS.
4/Contact people that send cellphone to space, maybe they could build for us cheap communication device for our experiment.
I forgot probably tons of important think we have to do, I am sure you will help me to make complete list and find easiest way to do it. Could we do it?
Title: Re: EM Drive Developments
Post by: cuddihy on 09/30/2014 11:21 am
Raketa, read back in the thread a ways, this is not a good idea. Current thrust level for both what Eagleworks and Woodward have studied are too low, and more importantly too inconsistent& not sustained, to provide sufficient impulse to see some an unquestioned effect in orbit, especially in high-drag environment like ISS altitude.
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 12:14 pm
Experimental data obtained using Dr. White's NASA inverted torsion pendulum

______________________________

"Serrano Field Effect" Boeing/DARPA device:
(@aceshigh quotes P. March (in another forum) stating that these results are in a vacuum (~5x10^-6 Torr) )

THRUST =   20 to 110 uN  impulse response (not a rectangular pulse)
SPECIFIC FORCE = 1 to 20 N/kW  (225 000 to 4.5 million times larger than a photon rocket)


______________________________

Cannae Testing:
(not tested in a vacuum by NASA)

THRUST =   40 uN  ~rectangular pulse (duration 30s to 40s)
SPECIFIC FORCE:  0.0014 N/kW (up to 300 times larger than a photon rocket)


______________________________

Tapered (Frustum) Cavity Testing: 
(not tested in a vacuum by NASA)

THRUST = 50 to 90 uN  ~rectangular pulse (duration 30s to 40s)
SPECIFIC FORCE=  0.003 N/kW to 0.0054 N/kW (700 to 1200 times larger than a photon rocket)

______________________________


NASA Eagleworks reports very small measured thrust forces (average lower than 100 microNewtons) for all these tested devices in Eagleworks inverted pendulum. 

Eagleworks noted in their report that

<<p. 14 The net force is calculated by accounting for the null force present in the system. Null testing is performed by attaching the RF drive system to a 50 ohm load and running the system at full power. The null force testing indicated that there was an average null force of 9.6 micronewtons present in the as tested configuration. The presence of this null force was a result of the DC power current of 5.6 amps running in the power cable to the RF amplifier from the liquid metal contacts. This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system. The null test data is also shown in Fig. 20.>>

So, the average null force is admitted to be 25% of the thrust force reported for the Cannae device. Eagleworks attempts to account for this null force (current causes the power cable to generate a magnetic field that interacts with the pendulum magnetic damper system) linearly as if it could just subtract this interaction:  Eagleworks does not account for nonlinear coupling in the system.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 09/30/2014 12:48 pm
I am not really following all the axion talk.

What is the line of reasoning about dielectrics and axions, blah blah, which pertains to propellantless drive?
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 01:18 pm
Nope, but the axiom angle might be related to any frequency difference between 2 photons.
Hmmm, notice the nonlinear waveform in slide 28 ?
Continued from http://forum.nasaspaceflight.com/index.php?topic=29276.msg1264292#msg1264292

Also see this, ( from 2014 "Hidden-sector photon and axion searches using photonic band gap structures" http://iopscience.iop.org/0954-3899/41/3/035005/pdf/g_41_3_035005.pdf  )

they <<propose a novel experimental approach in which microwave photonic lattice structures form part of a ‘light shining through the wall’-type experiment to search for WISPs. We demonstrate the potential to match and exceed the sensitivities of conventional experiments operating in the microwave regime>>

They use photonic band gap (PBG) structures (http://optoelectronics.eecs.berkeley.edu/ey1993josab102.pdf and    http://en.wikipedia.org/wiki/Photonic_crystal  ): <<Using the technique presented in [27, 28] we have verified that Qs of 10^6–10^9 can be achieved using this type of lattice (comparable to those of SC cavities). In addition to potentially higher Qs, the use of PBG structures enables us to reach frequencies higher than those accessible to conventional microwave structures, thereby covering the regime from a few GHz to the infra-red>>

See below the normalized electric field along the central line between the source and detector. The position of the dielectric scatterers is indicated by the grey lines

Notice even higher nonlinearity in the dielectrics than in the ADMX experiment's paper (shown at the bottom of this post).
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 02:02 pm
....

Reminds me that dielectric layers can be used to isolate the electric and magnetic interactions (as in the dielectric/metal/dielectric optical filter).  Maybe in the COMSOL model of the Sawyer resonator ?
...
Here they fabricate a flexible photonic crystal using alumina balls inserted in a Teflon tube

http://link.springer.com/article/10.1007%2Fs00339-010-5906-7
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 02:30 pm
Can anybody provide a link to information from Roger Shawyer showing the dielectric material Shawyer uses, the dielectric shape and dimensions and the dielectric location ?

Here Shawyer wrote <<we now let the waveguide include a dielectric-filled section at the smaller end of the taper and choose the dimensions to ensure a reflection-free transmission of the beam from the vacuum-filled section to the dielectric-filled section.>> and <<An experimental thruster with a tapered circular air-filled section and a cylindrical dielectric section was designed and manufactured.>>    http://www.newscientist.com/data/images/ns/av/shawyertheory.pdf

So, from that paper, we know that the dielectric is cylindrically shaped and it is located at the small-diameter end of the truncated cone (just like the Eagleworks frustum) but no further details.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/30/2014 05:41 pm
"and choose the dimensions to ensure a reflection-free transmission of the beam from the vacuum-filled section to the dielectric-filled section."

That doesn't make a lot of sense to me.  On the one hand it suggests that the dielectric is a half-wave "optical" thickness, and on the other hand that would increase the absorption at that end of the cavity and reduce the cavity Q.  (or at least the air part of the cavity Q, since you now have a dielectric resonator being fed from the air cavity)
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 05:46 pm
"and choose the dimensions to ensure a reflection-free transmission of the beam from the vacuum-filled section to the dielectric-filled section."

That doesn't make a lot of sense to me.  On the one hand it suggests that the dielectric is a half-wave "optical" thickness, and on the other hand that would increase the absorption at that end of the cavity and reduce the cavity Q.  (or at least the air part of the cavity Q, since you now have a dielectric resonator being fed from the air cavity)
I fully agree.  The theoretical writings (justifying why his inventions don't break conservation of momentum) from Shawyer don't make sense to me either.  But he may have -by chance and by pursuing his microwave idea- into something that works for entirely different reasons.

I also notice that Shawyer started using ferrites (for which he claimed (relative) permittivity ~38, although the usual values are ~14) but he is later talking about "dielectrics" and Eagleworks used PTFE Teflon for their similar "tapered cavity"

Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/30/2014 06:02 pm
Wasn't there some sort of comment about the Cannae drive cavity just becoming a matching network for the dielectric in the feed line. ?
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 06:17 pm
Wasn't there some sort of comment about the Cannae drive cavity just becoming a matching network for the dielectric in the feed line. ?
p. 10 of the "Anomalous Thrust ..." paper:

<<COMSOL Multiphysics® Analysis of Cannae Cavities

Computer modeling of the electric field within the pillbox and beam pipe (using COMSOL Multiphysics® software, hereafter referred to as “COMSOL®”) illustrates the relative weakness of the electric field in the vicinity of the cavity slots and relative strength of the electric field within the beam pipe, especially in the drive antenna coaxial cable and the region around the cable within the PFTE dielectric slug as seen in Fig. 14. Consideration of the dynamic fields in the ¼ wave resonance tube shows that there is always a net Poynting vector meaning that the RF launcher tube assembly with dielectric cylinder common to both the slotted and smooth test articles is potentially a Q-thruster where the pillbox is simply a matching network.>>

Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 06:22 pm
Wasn't there some sort of comment about the Cannae drive cavity just becoming a matching network for the dielectric in the feed line. ?

<<A. Tapered Cavity RF Evaluation, General
Figure 15 depicts one of the early COMSOL® models representing an early possible construction of a tapered RF unit alongside the actual construction that was finally implemented as informed by COMSOL® analysis. The RF drive antenna is the lower loop antenna seen in the wireframe representation of the assembly. An S11 (reflected power) plot prediction from COMSOL® is evaluated against the actual S11 output as measured by a vector network analyzer (VNA) connected to the lower antenna. Note that, in practice, a second (RF sense) antenna is present in the thruster in anticipation of implementing a phase lock loop (PLL) control approach to maintain resonance conditions over time. With the presence of the second RF sense antenna, COMSOL® can be used to provide an S21 (two-port delivered power) plot prediction that can also be evaluated against the actual S21 plot from a VNA connected to both the drive and sense antenna. Comparing the S11 and S21 predicted plots with actual plots helps ensure that the RF drive system is properly coupling with the desired electromagnetic mode at a particular frequency.
The COMSOL analysis iteration process was used prior to assembly to determine the optimal thickness and diameter of the dielectric RF resonator disc located at the small end of the thruster. The geometry of the RF resonator disc is a function of the resonator material’s relative permittivity, dissipation factor, and target resonance mode.>>
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 06:26 pm
Wasn't there some sort of comment about the Cannae drive cavity just becoming a matching network for the dielectric in the feed line. ?

The ones above are the earlier COMSOL analysis (Fig 15 in the report) for the future Frustum Tapered Cavity.

Here is the analysis for the future Frustum:
Title: Re: EM Drive Developments
Post by: raketa on 09/30/2014 08:25 pm
Rejoice and be glad, because great is your reward in heaven...

Yeah sure.  That's what they told Osama Bin Laden:

When OBL died, George Washington met him at the Pearly Gates. He slapped him across the face and yelled, "How dare you try to destroy the Nation I helped conceive?"

Patrick Henry approached, punched him in the nose and shouted, "You wanted to end our liberties but you failed."

James Madison followed, kicked him in the groin and said, "This is why I allowed our government to provide for the common defense!"

Thomas Jefferson was next, beat Osama with a long cane and snarled, "It was evil men like you who inspired me to write the Declaration of Independence. "

The beatings and thrashings continued as George Mason, James Monroe and 66 other early Americans unleashed their anger on the radical, socialist, leader.

As Osama lay bleeding and in pain, an Angel appeared. Osama wept and Said, "This is not what you promised me."

The Angel replied, "I told you there would be 72 VIRGINIANS waiting for you in Heaven. What did you think I said?"
really funny good job
Title: Re: EM Drive Developments
Post by: raketa on 09/30/2014 08:37 pm
Raketa, read back in the thread a ways, this is not a good idea. Current thrust level for both what Eagleworks and Woodward have studied are too low, and more importantly too inconsistent& not sustained, to provide sufficient impulse to see some an unquestioned effect in orbit, especially in high-drag environment like ISS altitude.
Ion engine thrust 20-250mN
Dragon solar panels could deliver 2kW power.
Chinese claim 720mN with 2.5 kW
NASA               91uN with just 0.017kW
Are you it will be not possible indicate slowing of decay Dragon trunk?
Title: Re: EM Drive Developments
Post by: RotoSequence on 09/30/2014 08:41 pm
Raketa, read back in the thread a ways, this is not a good idea. Current thrust level for both what Eagleworks and Woodward have studied are too low, and more importantly too inconsistent& not sustained, to provide sufficient impulse to see some an unquestioned effect in orbit, especially in high-drag environment like ISS altitude.
Ion engine thrust 20-250mN
Dragon solar panels could deliver 2kW power.
Chinese claim 720mN with 2.5 kW
NASA               91uN with just 0.017kW
Are you it will be not possible indicate slowing of decay Dragon trunk?

I think the problem with choosing to fund them now is the present absence of delineation between interactions with the torsion pendulum and actual thrust. Satellite power is not a problem.
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 09:06 pm
Raketa, read back in the thread a ways, this is not a good idea. Current thrust level for both what Eagleworks and Woodward have studied are too low, and more importantly too inconsistent& not sustained, to provide sufficient impulse to see some an unquestioned effect in orbit, especially in high-drag environment like ISS altitude.
Ion engine thrust 20-250mN
Dragon solar panels could deliver 2kW power.
Chinese claim 720mN with 2.5 kW
NASA               91uN with just 0.017kW
Are you it will be not possible indicate slowing of decay Dragon trunk?

I think the problem with choosing to fund them now is the present absence of delineation between interactions with the torsion pendulum and actual thrust. Satellite power is not a problem.
And

THRUST force =5*10^(-5) N to 9*10^(-5) N demonstrated for less than 40 seconds pulse duration
Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 09:20 pm
Raketa, read back in the thread a ways, this is not a good idea. Current thrust level for both what Eagleworks and Woodward have studied are too low, and more importantly too inconsistent& not sustained, to provide sufficient impulse to see some an unquestioned effect in orbit, especially in high-drag environment like ISS altitude.
Ion engine thrust 20-250mN
Dragon solar panels could deliver 2kW power.
Chinese claim 720mN with 2.5 kW
NASA               91uN with just 0.017kW
Are you it will be not possible indicate slowing of decay Dragon trunk?

I think the problem with choosing to fund them now is the present absence of delineation between interactions with the torsion pendulum and actual thrust. Satellite power is not a problem.
And

NASA Tapered Cavity THRUST force =5*10^(-5) N to 9*10^(-5) N demonstrated for less than 40 seconds pulse duration

And

NASA Tapered Cavity not tested in a vacuum
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/30/2014 10:34 pm
Been trying to get my head around axions.
1.  Not sure I understand why axions should all have the same mass.  Could be related to the guess that they might form a Bose-Einstein condensate?
2.  A Bose-Einstein condensate would certainly take care of the mass coupling problem.
3.  The coupling constant is the same in both directions:
axion->photons, photons->axion.
4.  The symmetry/asymmetry of the particle/anti-particle is confusing, but there is something rattling around in my memory about that. (later)
5.  A positive result from the Axion Dark Matter eXperiment (ADMX) would have a high degree of confidance in my mind, at least.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 09/30/2014 11:24 pm
Another interesting paper: http://arxiv.org/pdf/1403.5676.pdf

OK, here's the Bose-Einstein paper: http://arxiv.org/pdf/0901.1106v4.pdf

Title: Re: EM Drive Developments
Post by: Rodal on 09/30/2014 11:40 pm
Another interesting paper: http://arxiv.org/pdf/1403.5676.pdf

<<The observed Shapiro step anomalies of all four experiments consistently point towards an axion mass of 110*10^(-6) eV.>>

This mass is in the range that the ADMX experiment will be looking for in the future, but has not yet done so.

It is in the "B" region of the picture below.

It is in the region between what the ADMX experiment and CERN Telescope's have looking at.

It would explain why they haven't find the Axion (Dark Matter) yet.

The frequency that ADMX will use, ~30GHZ is about 15 times higher than the frequency at which NASA Eagleworks run the microwave devices. (Eagleworks run the Frustrum at 1.94 GHz).
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 12:11 am
OK, here's the Bose-Einstein paper: http://arxiv.org/pdf/0901.1106v4.pdf

So, as I see this it would work like Dr. White's momentum-transfer model within a "sea of weakly-interacting particles surrounding the outside and the inside of the spacecraft" with the following big changes (Cold Dark Matter instead of Quantum Vacuum virtual particles):

Quantum Vacuum Plasma--> Bose-Einstein Condensate of Axions  (but both acting as a "compressible fluid" in Dr. White's conceptual model)

electron-positron virtual particle pair --> Axions (Cold Dark Matter)

Unresolved issues: 

A) Four experiments consistently point towards an axion mass of 110*10^(-6) eV.  This mass implies a microwave frequency for ADMX experiment of ~30GHZ or about 15 times higher than the frequency at which NASA Eagleworks run the Truncated Cone Cavity (1.94 GHz).

B) The NASA Eagleworks experiments are missing the ~3 T magnetic field surrounding the microwave cavity.  The only magnetic field in the Eagleworks  experiments is the one produced by the three neodymium (NdFeB Grade N42) block magnets, which are there only by chance ( to dampen the swinging and torsional oscillations of the inverted pendulum).  The magnetic damper is located about a foot away from the tested microwave device (Cannae or Frustum). The magnetic field intensity at the surface of a neodymium magnet is 1.25 T

Still, it makes much more sense than the "exotic" theories: a real particle (axions) from the exterior exchanging real momentum with the photons and not interacting with the metal walls of the cavity:

<<
2. A Bose-Einstein condensate would certainly take care of the mass coupling problem.
3.  The coupling constant is the same in both directions: axion->photons, photons->axion.
>>

It doesn't present the much greater difficulties associated with Woodward's theory and the Quantum Vacuum theory.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 02:20 am
OK, here's the Bose-Einstein paper: http://arxiv.org/pdf/0901.1106v4.pdf
Is there an estimate of what would be the effective density (mass over occupied volume) of the Bose-Einstein condensate of axion Cold Dark Matter?
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 02:50 am
OK, here's the Bose-Einstein paper: http://arxiv.org/pdf/0901.1106v4.pdf
Is there an estimate of what would be the effective density (mass over occupied volume) of the Bose-Einstein condensate of axion Cold Dark Matter?

From http://arxiv.org/pdf/1403.5676.pdf   

according to page 5:

<<estimate the axion mass as 110 eV and the axionic dark matter energy density near the earth is rho = 0.051GeV/m^3>>

But according to page 1:

<<An experiment by Ho mann et al. based on S/N/S Josephson junctions [20], discussed in detail in [14], provided evidence for an axion mass of 110 eV and an axionic dark matter density of about 0.05 GeV/cm^3>>

Although the mass estimates agree 100%, there is a difference of 1 million between these two density numbers (notice the difference between cubic centimeters and cubic meters in the denominators).  The larger number (0.05 GeV/cm^3) makes more sense to me, as the lower number (0.05 GeV/m^3) is even lower than the measured density of the quantum vacuum.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 12:24 pm
Here is a paper written to describe the Casimir energy between a metallic plate and a dielectric plate within a cavity. The configuration is somewhat similar to the Tapered Cavity tested at EagleWorks.

http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml# (http://math.scichina.com:8081/sciAe/EN/abstract/abstract377962.shtml#)

I wonder if someone can help interpret this paper. To me, it does not seem consistent with what has been published elsewhere, in particular I see an unfamiliar term

Quote
where -pi/(24a^2) is the Casimir force between two ideal conducting plates separated by a.

But also this paper is developed in a reference system where c=1, h-bar=1. That is a common system but how does one convert the results into standard units of measure.

I forgot, if I ever knew how.

http://en.wikipedia.org/wiki/Speed_of_light (http://en.wikipedia.org/wiki/Speed_of_light)

http://en.wikipedia.org/wiki/Planck_constant (http://en.wikipedia.org/wiki/Planck_constant)

Well yes I know that, but the author uses "1" in the equations derivation for each of these terms so where do I substitute the real values back into the end result to get real measurable values? Am I forced to carefully follow the derivation through to the end then know where the c's and h-bars go? (numerator, denominator, power, etc.)

I just remembered that some particle physicists use a system (to simplify the equations) where the fundamental SI units (mass,length,time) {kg,m,s} are replaced by these other fundamental units (Planck's constant, speed of light, GeV),{h,c,GeV} where h=1.055*10^(-34) J, c=2.998*10^8 m/s and GeV=1.602*10^(-10) J.  Then, in the {h,c,GeV} "system", mass, length and time are no longer fundamental, but they get "units" as shown in the table below.  In that "system" h=c=1, because in that "system" h=1 unit (a fundamental unit in that system) and c=1 unit (another fundamental unit in that system).

Then, for example, Einstein's energy momentum equation E^2 = p^2 c^2 + m^2 c^4
becomes simply E^2 = p^2 + m^2

To convert back into SI units one has to reinsert everywhere the missing factors of h and c, using dimensional analysis.  Yes, I agree, it is a pain to do that, but you don't really have to know the derivation.  You just have to know what type of quantity (length, mass, time, energy, momentum, etc.) it is, and convert it back to SI units, using the appropriate factors of  h=1.055*10^(-34) J, c=2.998*10^8 m/s and GeV=1.602*10^(-10) J as required, so that the quantity has proper SI dimensions.

Quantity                       SI units                          {h,c,GeV}                                          h=c=1 "units"

Mass                             kg                                    GeV/c^2                                                     GeV
Length                           m                                    (GeV/(hc))^(-1)                               (GeV)^(-1)
Time                              s                                     (GeV/(h))^(-1)                                 (GeV)^(-1)
Momentum                   kg m s^(-1)                     GeV/c                                                         GeV
Energy                          kg m^2 s^(-2)                 GeV                                                            GeV

_________________

The only reason I remembered this was because I was getting my mind around the cold dark matter density, (see post above) and comparing it with the quantum vacuum energy density, I found out that some Internet sources express this density as (GeV)^4 instead of GeV/m^3.  The reason for this follows from the above, because Length in this "system" has "units" of GeV^(-1) hence volume has units of GeV^(-3) and hence energy density (and mass density) have units of GeV/(GeV^(-3)) = (GeV)^4
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/01/2014 01:07 pm
OK, here's the Bose-Einstein paper: http://arxiv.org/pdf/0901.1106v4.pdf

So, as I see this it would work like Dr. White's momentum-transfer model within a "sea of weakly-interacting particles surrounding the outside and the inside of the spacecraft" with the following big changes (Cold Dark Matter instead of Quantum Vacuum virtual particles):

Quantum Vacuum Plasma--> Bose-Einstein Condensate of Axions  (but both acting as a "compressible fluid" in Dr. White's conceptual model)

electron-positron virtual particle pair --> Axions (Cold Dark Matter)

Unresolved issues: 

A) Four experiments consistently point towards an axion mass of 110*10^(-6) eV.  This mass implies a microwave frequency for ADMX experiment of ~30GHZ or about 15 times higher than the frequency at which NASA Eagleworks run the Truncated Cone Cavity (1.94 GHz).

B) The NASA Eagleworks experiments are missing the ~3 T magnetic field surrounding the microwave cavity.  The only magnetic field in the Eagleworks  experiments is the one produced by the three neodymium (NdFeB Grade N42) block magnets, which are there only by chance ( to dampen the swinging and torsional oscillations of the inverted pendulum).  The magnetic damper is located about a foot away from the tested microwave device (Cannae or Frustum). The magnetic field intensity at the surface of a neodymium magnet is 1.25 T

Still, it makes much more sense than the "exotic" theories: a real particle (axions) from the exterior exchanging real momentum with the photons and not interacting with the metal walls of the cavity:

<<
2. A Bose-Einstein condensate would certainly take care of the mass coupling problem.
3.  The coupling constant is the same in both directions: axion->photons, photons->axion.
>>

It doesn't present the much greater difficulties associated with Woodward's theory and the Quantum Vacuum theory.

The magnetic field is there to adjust the phase relationship between the photons (one is virtual in the Primicoff effect w/ particle interactions)  That's not the only way, the photons can have different frequencies.  The energy could be made up if 1 photon comes from the thermal IR present at room temperature.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/01/2014 01:44 pm
Found the below link while researching Unruh. I've been reading about this guy's theory of modified inertia called MiHsC. Here are his comments on emdrive:

http://physicsfromtheedge.blogspot.it/2014/09/emdrives-mihsc.html



Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 01:51 pm
I was suggesting first to proof/disproof in space, because lot of people thinking this is good idea, why we didn't try to make it happen.
I am putting my money where  my mouth is ready to pledge initial $1000 for this project.
1/Could we contact professor Dr Woodward if he will be interesting to participate and build his apparatus for space environment.
2/We have to find who will do crowdsourcing for us. Does anybody have experience or could recommend it somebody who has good reputation. . .
An in space demo is a TRL7 demo.  Woodward is at TRL5 right now.  Before you go to space, what you want is a phase 1, TRL6 demo that is very close to the commercial grade thruster you'd use for phase 2, TRL7--meaning similar in magnitude thrust (20 mN is fine if the FOM's are good), Figures of Merit (FOM's) for thrust to mass and thrust to power that can fly a spacecraft, thermal stability such that the thruster will work continuously in space where only black body radiation (T^4) can be used for cooling, and of course the continuous operation.  Woodward is currently a long way from these things, but these are the things I'm currently looking to finance through a DARPA grant if I can find the proper Principle Investigator.  Anyone who wants the job should let me know.  We already have a basic design that should meet all these above criteria.  PhD's in physics, electrical engineering, mechanical engineering, aerospace engineering and materials science will be considered. 

Note we're planning to run a concurrent project to develop our own proprietary radiation hardening technology that will allow all future spacecraft to fly through the Van Allen Belt undamaged.  Plasma physicists or anyone who thinks they have the qualifications for that project should likewise feel free to contact me.

Woodward is working on some crowdsourcing at present, but note that he is only concerned with proof of science, not proof of technology as this above.  He's not looking at a TRL7 demo while we're planning around one.  Note too that in-space demos are very expensive.  You not only can't do them on a hobby budget; you can't do them on a crowdsourcing budget.  It is millions of dollars to loft a spacecraft to LEO unless you use a nanosat, in which case you might get the launch for free, but you'll then have to pay for some expensive miniaturization, so its millions of dollars either way.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 02:17 pm
Found the below link while researching Unruh. I've been reading about this guy's theory of modified inertia called MiHsC. Here are his comments on emdrive:

http://physicsfromtheedge.blogspot.it/2014/09/emdrives-mihsc.html

Thanks.  This is another interesting idea. It is more connected with Dr. White's thoughts about the quantum vacuum.
The problem is that Unruh's mathematical derivation is still very controversial.  Several physicists (i.e. http://link.springer.com/article/10.1134%2FS0021364009080025) state that Unruh's calculations improperly imposed boundary conditions at the horizon (stating that the decomposition of integrals over the entire range of the boost parameter into parts, as done by Unruh, is inapplicable ):

<<This means that the Unruh “effect” is absent for any statistics of particles. Thus, both the theoretical predictions and numerous proposals of experiments based on the assumption of the existence of this effect are unfounded.>>


_________

EDIT: I find amusing his description of the Shawyer (and NASA's "tapered cavity") drive as follows <<the EmDrive is .. a microwave oven built into a megaphone>>  :)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/01/2014 02:54 pm
I've been watching Saturday morning cartoons.  Did I miss anything?

Hardy har har...
Title: Re: EM Drive Developments
Post by: wembley on 10/01/2014 03:24 pm
Can anybody provide a link to information from Roger Shawyer showing the dielectric material Shawyer uses, the dielectric shape and dimensions and the dielectric location ?

Have you tried asking him?

But I don't think he uses that approach any more:
"The first thruster built by SPR Ltd and tested in 2003 also used a dielectric section, but to obtain our subsequent high thrust levels, we abandoned the dielectric and concentrated on our present cavity design."

Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 03:42 pm
...Woodward is working on some crowdsourcing at present, but note that he is only concerned with proof of science, not proof of technology as this above.  He's not looking at a TRL7 demo while we're planning around one.  ..
Concerning only any possible technical reasons for your statement that "he is only concerned with proof of science, not proof of technology:"

Prof. Woodward obtained a patent with Thomas Mahood (http://www.google.com/patents/US6347766 ) (both as inventors and as assignees):

Publication number   US6347766 B1
Application number   US 09/549,475
Publication date   Feb 19, 2002
Filing date   Apr 14, 2000
Priority date   Jan 23, 1999

So, at that point in time, at least, he must have been interested in proof of technology, as the US Patent Office (from our Constitution) grants a patent, and hence a monopoly, to reward proof of such technology and its future development.   It is interesting that according to Google Patent Search:

Fee status:   Lapsed

for the above-mentioned patent.  (With the important Google disclaimer that this is not a legal conclusion).

It would be interesting if you could expand:

Does Prof. Woodward have other patents that superseded the above-mentioned patent?  If indeed the above information is correct that the fee status has lapsed, and if you are correct in stating that <<he is only concerned with proof of science, not proof of technology >> has anything changed technically since he originally obtained the above-mentioned patent that would motivate to concentrate now on proof of science, rather than proof of technology ?

Of course, there are shades of gray in all this, for example his source of funds at that point in time may have been the one pushing for a patent.  I am not interested in his personal motivations, I'm only interested in whether there are some technical reasons (for example the "bulk acceleration" issue, etc.) that may have produced a change of priorities concerning proof of technology.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 03:50 pm
...
But I don't think he uses that approach any more:
"The first thruster built by SPR Ltd and tested in 2003 also used a dielectric section, but to obtain our subsequent high thrust levels, we abandoned the dielectric and concentrated on our present cavity design."
Where is the above quotation from? (I would appreciate a link for it so that I can further understand the context)

Thanks for your response

_________
PS: I looked for it , but I could not find that statement in this 2006 report:   http://www.newscientist.com/data/images/ns/av/shawyertheory.pdf
Title: Re: EM Drive Developments
Post by: birchoff on 10/01/2014 05:26 pm
The LHC and the discovery of the Higgs Boson also relied on tens of trillions of data points. Before they started looking for new science, they made sure they rediscovered every other standard model particle to verify that their instruments were accurately calibrated. The discovery of the Higgs Boson relied on the legacy of many other scientific instruments, rather than just the Large Hadron Collider's detectors. Even then, it's accepted scientific literature, in large part, because reproduction steps are available to anyone willing to build another large particle accelerator.

The secret to the LHC's success is a long history of collaboration and openness about their scientific results. Secrecy is the enemy of progress.


another secret is the huge amount of money they have. Imagine a single guy trying to discover the Higgs Boson with an apparatus created with his own money. And other labs not interested in replicating the experiments unless you give yourself the machine you built (and they just use other methods to test).

and your signals are not that strong. You see only hints of the Higgs Boson in your machine.

When you look at it this way, it looks even less okay for EM drive proponents to withhold data from the scientific research community. Major research institutions have the resources to find more signal amidst noise than hobbyists could ever hope for. EM drive researchers should be reaching out to the broader scientific community, to give scientists, researchers, and engineers some evidence, and good faith, that there is something worth investigating in that direction.

To be clear what information has Woodward withheld in his research?

compared to what information has EagleWorks withheld in their research?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 05:30 pm
Quote from: Rodal
So, at that point in time, at least, he must have been interested in proof of technology, as the US Patent Office (from our Constitution) grants a patent, and hence a monopoly, to reward proof of such technology and its future development.   It is interesting that according to Google Patent Search:

Fee status:   Lapsed

for the above-mentioned patent.  (With the important Google disclaimer that this is not a legal conclusion).

It would be interesting if you could expand:

Does Prof. Woodward have other patents that superseded the above-mentioned patent?  If indeed the above information is correct that the fee status has lapsed, and if you are correct in stating that <<he is only concerned with proof of science, not proof of technology >> has anything changed technically since he originally obtained the above-mentioned patent that would motivate to concentrate now on proof of science, rather than proof of technology ?

Of course, there are shades of gray in all this, for example his source of funds at that point in time may have been the one pushing for a patent.  I am not interested in his personal motivations, I'm only interested in whether there are some technical reasons (for example the "bulk acceleration" issue, etc.) that may have produced a change of priorities concerning proof of technology.
That patent was owned by Woodward and Fullerton, and it was Fullerton's responsibility to pay to keep it in force.  They failed in that obligation.  At this point in his 70's, as a survivor of several different kinds of terminal cancer and a long way down the road from that early work, I think he is just more satisfied to do the proof of science rather than look at what it takes to build spaceships.  However, he did file for another patent with SSI a couple years ago and I am not sure about the status of that.  That was not a replacement patent.  It was for the power system instead of the thruster.

I was speaking more from the perspective that he is not currently pursuing a proof of technology demonstrator.  The PMN he is currently using has far too narrow a thermal bandwidth to have commercial applications, IMHO.  It only maintains its Colossal Dielectric Constant (CDC) across a couple degrees K so were he to try to put it into a satellite, it appears it would consume more power to stabilize it thermally, than the thruster itself would consume.  So you could easily have a situation where the pair of systems--the thruster and its thermal control system, dissipate 3-4X as much as the thruster alone.  That is not a commercial solution.  IMHO, a commercial solution will operate across a broad range of temperatures, in and out of shadow, pulsed, repeated and continuous thrust, and will operate at higher frequencies than PMN is capable of as well, since thrust/mass and thrust/power both scale with the frequency of operation.

I don't think anything has changed technically that would change Jim's attitude toward commercialization save that he is 18 years older.  He's no longer planning for 15 years down the road and that is true of most of the people involved with his work.  I'm an exception, but I'm younger than almost everyone else involved this last decade.
Title: Re: EM Drive Developments
Post by: aero on 10/01/2014 05:32 pm
I was wondering how much energy was stored within the cavity (truncated frustum) so have been (off and on) looking at math for which I have absolutely no background beyond undergraduate course work. Using the input power and Q-factors given, I calculate that the RF wave B field and E field has energy like:

B field range from 0.27 to 0.62 tesla, and
E field range from 80.4 to 184.8 Mv per metre.

Are these reasonable values?

I also calculated that the energy mass of the RF wave ranges from 0.00064 to 0.0034 micrograms.

At this point I don't know what to do with these numbers but maybe someone will find them interesting.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 05:40 pm

That patent was owned by Woodward and Fullerton, and it was Fullerton's responsibility to pay to keep it in force.  They failed in that obligation.  At this point in his 70's, as a survivor of several different kinds of terminal cancer and a long way down the road from that early work, I think he is just more satisfied to do the proof of science rather than look at what it takes to build spaceships.  ...


I'm so sorry to hear that Prof. Woodward went through that.  My thoughts and prayers are that he is back to full health.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 05:44 pm
I was wondering how much energy was stored within the cavity (truncated frustum) so have been (off and on) looking at math for which I have absolutely no background beyond undergraduate course work. Using the input power and Q-factors given, I calculate that the RF wave B field and E field has energy like:

B field range from 0.27 to 0.62 tesla, and
E field range from 80.4 to 184.8 Mv per metre.

Are these reasonable values?

I also calculated that the energy mass of the RF wave ranges from 0.00064 to 0.0034 micrograms.

At this point I don't know what to do with these numbers but maybe someone will find them interesting.

We know from the "Anomalous Thrust ..." report that the COMSOL finite element calculations display a maximum Electric field of 47189 Volts per meter (p. 10, Fig. 14).  I couldn't find any numerical information given for the Electric Field results from COMSOL for the Tapered Cavity.

Also, you may find something useful for comparison in FIg. 16 of the report, for the predicted and actual gain (S21), as attached here (vertical scale: Amplitude (dB); horizontal scale: frequency):

(The numbering convention for S-parameters is that the first number following the “S” is the port where the signal emerges, and the second number is the port where the signal is applied. S21 is a measure of the signal coming out port 2 relative to the RF stimulus entering port 1: the ratio of transmitted to incident voltage signals.  S21 is the forward complex transmission coefficient)

It is apparent that the comparison from this COMSOL analysis to the actual results is not that great...
Title: Re: EM Drive Developments
Post by: raketa on 10/01/2014 05:52 pm
I was suggesting first to proof/disproof in space, because lot of people thinking this is good idea, why we didn't try to make it happen.
I am putting my money where  my mouth is ready to pledge initial $1000 for this project.
1/Could we contact professor Dr Woodward if he will be interesting to participate and build his apparatus for space environment.
2/We have to find who will do crowdsourcing for us. Does anybody have experience or could recommend it somebody who has good reputation. . .
An in space demo is a TRL7 demo.  Woodward is at TRL5 right now.  Before you go to space, what you want is a phase 1, TRL6 demo that is very close to the commercial grade thruster you'd use for phase 2, TRL7--meaning similar in magnitude thrust (20 mN is fine if the FOM's are good), Figures of Merit (FOM's) for thrust to mass and thrust to power that can fly a spacecraft, thermal stability such that the thruster will work continuously in space where only black body radiation (T^4) can be used for cooling, and of course the continuous operation.  Woodward is currently a long way from these things, but these are the things I'm currently looking to finance through a DARPA grant if I can find the proper Principle Investigator.  Anyone who wants the job should let me know.  We already have a basic design that should meet all these above criteria.  PhD's in physics, electrical engineering, mechanical engineering, aerospace engineering and materials science will be considered. 

Note we're planning to run a concurrent project to develop our own proprietary radiation hardening technology that will allow all future spacecraft to fly through the Van Allen Belt undamaged.  Plasma physicists or anyone who thinks they have the qualifications for that project should likewise feel free to contact me.

Woodward is working on some crowdsourcing at present, but note that he is only concerned with proof of science, not proof of technology as this above.  He's not looking at a TRL7 demo while we're planning around one.  Note too that in-space demos are very expensive.  You not only can't do them on a hobby budget; you can't do them on a crowdsourcing budget.  It is millions of dollars to loft a spacecraft to LEO unless you use a nanosat, in which case you might get the launch for free, but you'll then have to pay for some expensive miniaturization, so its millions of dollars either way.
Hi Ron,
it is awesome that there is plan. What do you think to try  to partner with Spacex and use Dragon trunk for  carrying device. If we could use power input from Dragon solar panels, how much space and weight you need to occupate without miniaturization. 
Thank you
Jan
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 06:04 pm
What you're describing is one of 5 plans in progress for the DARPA grant process.

DARPA grants are very odd compared to other grants because they require the whole TRL process.  They generally cover TRL6 and 7 in 2 phases, but they require the TRL-1-5 history, the phase 1 TRL6 plan in detail, the follow on TRL7 plan in detail (though they expect changes after phase 1), the plan for the jump to TRL8 commercialization including whom will build the product and a market analysis of who would pay for it.  What you're taking about is part of the TRL9 analysis, which is to provide Dragon with an M-E trunk that can take it to the Moon and Mars.  This is one of 5 early "low thrust" applications, but the trunk needs to be completely refitted so this is not a cheap nor simple issue.

What is cheap is to catch a free ride to orbit for a nanosat, but this still requires miniaturization.  And really you don't want to send stuff to orbit without paying for that step because that is the step where radiation hardening takes place, and where the actual FOM's for future spacecraft with all their working systems come from.  You want the grant to pay for the miniaturization so you have it ready to go to market.  In our case, miniaturization does not happen until phase 2/TRL7, but this is quite normal and the electrical engineering for this can be shopped out to literally dozens of places so there is little challenge there save how it affects delivery times of other portions of the project.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 07:53 pm
Quote from: frobnicat
. . .my feeling (as an average mainstream science educated person somehow following the topic) is that the various teams involved in experiments are choosing the wrong methodology and should follow some guidelines for fundamental research experimentalists
I'm sorry but that's not true at all.  Obviously, you have not read the book.
Quote
please produce a complete detailed description of one single self contained airtight device, thermally isolated, energetically isolated, electromagnetically shielded, that is reproducible and will guarantee anyone caring to follow the instructions to observe a thrust/power effect better than 1/c for a few seconds
While I understand and appreciate what you're trying to do, all i can say in few words is, you are putting out criteria that are unreasonable and unnecessary.  In the words of Dr. Dennis Bushnell, NASA's Chief Scientist and point man for all propulsion and power exploration like these, the reason NASA is not biting is that they don't have anyone able to judge the theory.  The experimental setup is not the trouble.  Since they cannot do a real evaluation of theory, what they've asked for is more thrust, which is what Jim is working on.  Rumor is, Stennis, JPL, Glenn and one of the National Labs are all considering replications of the Eagle work, and this all from a little conference paper!  That's quite a reaction!  And let me note again, that when you are not familiar with the details of what has been published on this subject, to complain there has not be what you want published, is a little silly.  Read Woodward's book.  It's a fascinating read meant for engineers.  I promise it is fun or I owe you a beer.
Quote
So far my feeling is that the "propellantless propulsion proponents" are doing a really great job at NOT convincing an (admittedly already reluctant) mainstream science community that there is any effect at all.
Agreed, but those who have read the book are starting to make their sentiments known.  Sometimes these things take time.  The book is not even 2 years old.
Quote
But it seems strange to me (and my guess to a majority of scientists and engineers), if effect is real then it is worth fundamental physics methodology, not necessarily billions $ but at least complete open access to blueprints, complete experimental datafiles (including preliminary adjustments and settings) and not just snapshots of a few screens. . .
All of Woodward's data has been given to Creon Levit, NASA's main comp guy at Ames.  Also this summer, Woodward upgraded his instrumentation to Labview, so the data will be easier to obtain and digest in the future.  I believe that data acquisition system goes online in just another week or so.
Quote
. . .can't they dump the raw values of those instruments on some disk?
As noted, all what you're asking for save the self-contained issue has previously been addressed, and you should not presume Eagle hasn't done the same.  NASA has its own analysts and they don't need unpaid peanut galleries to make decisions.  Nothing against this forum, but online engineering forums are notoriously ill-mannered and dysfunctional when it comes to real analysis.  You should not expect to see that kind of thing here.  Dennis and Creon are top notch guys.  Sometimes you just need to wait for the hammer to fall.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 07:57 pm


Ron, I'm new to this site, but it is my impression is that it would help if you would also include the author of the quotes that you are quoting above ( http://forum.nasaspaceflight.com/index.php?topic=29276.msg1265094#msg1265094  ), otherwise:

1) The author of the quotes is not going to get a message that you are addressing what he/she wrote
2) The readers may infer wrong inferences as to who is the author of the quote

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 08:02 pm
I'll do what I can but my time here is very limited today.  I'm only barely keeping up. as is.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 08:06 pm
I'll do what I can but my time here is very limited today.  I'm only barely keeping up. as is.

Well you may want to consider specifying who is the author of the quotes you are quoting, particularly when you write things like:  << NASA has its own analysts and they don't need unpaid peanut galleries to make decisions.  Nothing against this forum, but online engineering forums are notoriously ill-mannered and dysfunctional when it comes to real analysis.  >>
Title: Re: EM Drive Developments
Post by: birchoff on 10/01/2014 08:07 pm
What you're describing is one of 5 plans in progress for the DARPA grant process.

DARPA grants are very odd compared to other grants because they require the whole TRL process.  They generally cover TRL6 and 7 in 2 phases, but they require the TRL-1-5 history, the phase 1 TRL6 plan in detail, the follow on TRL7 plan in detail (though they expect changes after phase 1), the plan for the jump to TRL8 commercialization including whom will build the product and a market analysis of who would pay for it.  What you're taking about is part of the TRL9 analysis, which is to provide Dragon with an M-E trunk that can take it to the Moon and Mars.  This is one of 5 early "low thrust" applications, but the trunk needs to be completely refitted so this is not a cheap nor simple issue.

What is cheap is to catch a free ride to orbit for a nanosat, but this still requires miniaturization.  And really you don't want to send stuff to orbit without paying for that step because that is the step where radiation hardening takes place, and where the actual FOM's for future spacecraft with all their working systems come from.  You want the grant to pay for the miniaturization so you have it ready to go to market.  In our case, miniaturization does not happen until phase 2/TRL7, but this is quite normal and the electrical engineering for this can be shopped out to literally dozens of places so there is little challenge there save how it affects delivery times of other portions of the project.

Hold tha damn phone.

Am I correct in my interpretation that you or some group of people you know is actively attempting to Sheppard Woodward's work all the way through to commercialization?????
Title: Re: EM Drive Developments
Post by: birchoff on 10/01/2014 08:14 pm
I'll do what I can but my time here is very limited today.  I'm only barely keeping up. as is.

Well you may want to consider specifying who is the author of the quotes you are quoting, particularly when you write things like:  << NASA has its own analysts and they don't need unpaid peanut galleries to make decisions.  Nothing against this forum, but online engineering forums are notoriously ill-mannered and dysfunctional when it comes to real analysis.  >>

Don't know about anyone else, but I would assume your quote of Ron is his personal opinion. Even though I tend to agree with him on this issue. While I appreciate the forum and the participation to date. My strong suspicion is that outside of Woodward's mailing list, we will not get any more information about these type of propulsion devices till Another paper or set of results is published. I think the EagleWork's guys are only concerned with answering to their source of funding and the respective NASA officials that they have to report to.

I think the biggest value of this thread so far is that your [Rodal] attempt at breaking down what has been reported so far has forced people with some more knowledge than what is easily available to find their way here.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 08:21 pm
I'll do what I can but my time here is very limited today.  I'm only barely keeping up. as is.

Well you may want to consider specifying who is the author of the quotes you are quoting, particularly when you write things like:  << NASA has its own analysts and they don't need unpaid peanut galleries to make decisions.  Nothing against this forum, but online engineering forums are notoriously ill-mannered and dysfunctional when it comes to real analysis.  >>

Don't know about anyone else, but I would assume your quote of Ron is his personal opinion. Even though I tend to agree with him on this issue. While I appreciate the forum and the participation to date. My strong suspicion is that outside of Woodward's mailing list, we will not get any more information about these type of propulsion devices till Another paper or set of results is published. I think the EagleWork's guys are only concerned with answering to their source of funding and the respective NASA officials that they have to report to.

I think the biggest value of this thread so far is that your [Rodal] attempt at breaking down what has been reported so far has forced people with some more knowledge than what is easily available to find their way here.
Yes, that was my opinion he quoted.  And I'm sorry if that truth seems to annoy but it is the truth.  NASA does not consult engineering forums like these when they make decisions.  In fact, I have several times advised Dr. Bushnell what forums like this are saying and doing as I think it's worth knowing.  Dennis does what I used to do back when I was working for the Advanced Aerospace Research Center and we have compared notes on more than one occasion.  He certainly does not need to hear what goes on in places like this but he does listen, and as I've already noted, anyone who has been around a few years on one or more of these boards knows how opinionated and predictable these forums are.
Title: Re: EM Drive Developments
Post by: birchoff on 10/01/2014 08:26 pm
Quote
Hold tha damn phone.

Am I correct in my interpretation that you or some group of people you know is actively attempting to Sheppard Woodward's work all the way through to commercialization??
Yes.

And where can a space geek go to keep abreast of such developments?
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 08:26 pm
I'll do what I can but my time here is very limited today.  I'm only barely keeping up. as is.

Well you may want to consider specifying who is the author of the quotes you are quoting, particularly when you write things like:  << NASA has its own analysts and they don't need unpaid peanut galleries to make decisions.  Nothing against this forum, but online engineering forums are notoriously ill-mannered and dysfunctional when it comes to real analysis.  >>

Don't know about anyone else, but I would assume your quote of Ron is his personal opinion. Even though I tend to agree with him on this issue. While I appreciate the forum and the participation to date. My strong suspicion is that outside of Woodward's mailing list, we will not get any more information about these type of propulsion devices till Another paper or set of results is published. I think the EagleWork's guys are only concerned with answering to their source of funding and the respective NASA officials that they have to report to.

I think the biggest value of this thread so far is that your [Rodal] attempt at breaking down what has been reported so far has forced people with some more knowledge than what is easily available to find their way here.
Hi @birchoff,

I am not the author of the quotes that Ron has quoted, otherwise I would answer them.

I do find Ron's assertion (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1265094#msg1265094) that <<NASA has its own analysts and they don't need unpaid peanut galleries to make decisions>> out of place and offensive to this forum.  This NASASpaceFlightForum has well motivated scientists and engineers attracted to the implications of this technology and just trying to ascertain the physics behind it (whether a real physical effect or artifact).  I do see Ron's assertions above as questioning this NASASpaceFlightForum, which in my opinion has among the highest quality involvement and a very rich theory of positive contributions .

Ron, has further compounded this with his latest charge (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1265109#msg1265109) that <<  There is always a handful of people who want to prove how bright they are, even if while doing this they prove they're willing to judge work they're unfamiliar with. 

It's pretty funny, actually.>>
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 08:32 pm
Dr. Rodal, I agree with your opinion of the guys posting in this forum.  Can I presume you agree that you, amongst others here, have posted now quite a few opinions about work you're not familiar with, and thus validate my observation that these forums do indeed do what I'm saying they do?

And it is funny.  :-)  And you can find the same at Talk Polywell, and Next Big Future and Physics.org and Phys.org, etc.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 08:38 pm
Dr. Rodal, I agree with your opinion of the guys posting in this forum.  Can I presume you agree that you, amongst others here, have posted now quite a few opinions about work you're not familiar with, and thus validate my observation that these forums do indeed do what I'm saying they do?

And it is funny.  :-)  And you can find the same at Talk Polywell, and Next Big Future and Physics.org and Phys.org, etc.
You are incorrect.   I have only commented about the specific papers I have read and I have made that clear in my posts, including links and explicit quotations
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 08:49 pm
Do people get a sense of a moving goal post ? .  When experiments do not show the predicted effect, multiplicative fudge factors ranging from 0 to 1, such that for a value of zero there is no Woodward effect, are proposed by Buldrini.  No estimation is presented of what the value of the fudge factors should be. 

Now a new condition is added that the effect won't manifest itself unless the drive is simultaneously accelerated by external power.    When did this condition first appear in Woodward's publications?
What magnitude of “bulk” acceleration is large enough  according to Woodward?

It is elucidating that we get now a recognition by Woodward that:

<<simply charging and discharging capacitors will not produce mass fluctuations. >>

This effectively recognizes that solely replacing fluctuations in the rest energy by the fluctuations in the electric power input to a capacitor is not just "overly optimistic" but invalid.  See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260795#msg1260795  He now adds the extra condition that the device needs to be simultaneously accelerated to an unspecified large enough “bulk” acceleration.  The new experimental setup used by Woodward involves the linear (in voltage) piezoelectric effect and the quadratic (in voltage) electrostrictive effect in a stack of PZT disc capacitors.
This above, Dr. Rodel; was brought to my attention in another forum, because you are here slandering a good man and accusing him of moving the goal posts, saying the predicted effect didn't show up, using fudge factors when in fact no thrust magnitude prediction had been made for good reason, and of creating "new conditions" when in fact these conditions are in the peer reviewed literature going back almost 20 years now.  If I'm wrong and you've been unusually restrained you have my apology but it looks like you're acting very typically for this sort of venue.
Title: Re: EM Drive Developments
Post by: francesco nicoli on 10/01/2014 08:49 pm
quite funny indeed. I always believed that rational choice decision making would push someone who believes that a certain activity is meaningless, conduced by uniformed people, on a non-interesting platform, not to participate in any of the activities of that uninteresting platform.

Here however we have a clear demonstration of how rational choice theory often fails. It is always complicate to justify rationally the behaviour of individuals wasting their time to say "there is nothing to say here because you are all wrong and uninteresting".

Title: Re: EM Drive Developments
Post by: birchoff on 10/01/2014 08:54 pm
Dr. Rodal, I agree with your opinion of the guys posting in this forum.  Can I presume you agree that you, amongst others here, have posted now quite a few opinions about work you're not familiar with, and thus validate my observation that these forums do indeed do what I'm saying they do?

And it is funny.  :-)  And you can find the same at Talk Polywell, and Next Big Future and Physics.org and Phys.org, etc.
You are incorrect.   I have only commented about the specific papers I have read and I have made that clear in my posts, including links and explicit quotations.

In my limited time here Rodal you are honestly the first most consistent I have come across, that said most of my time has been spent on this thread in particular. Outside of this thread and forum you would be considered an anomaly.
Title: Re: EM Drive Developments
Post by: 93143 on 10/01/2014 09:03 pm
I have only commented about the specific papers I have read and I have made that clear in my posts, including links and explicit quotations.

Yes, but your comments are not always in strict logical progression from the contents of those papers, which I myself have found very frustrating in the past.

I'd spend more time here, but I don't have it; if I were to engage in detail it could easily suck up weeks of work.  I tend to put a lot of effort into such posts...

Also, check your PMs (been a while, but late is better than never)...
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 09:05 pm
Do people get a sense of a moving goal post ? .  When experiments do not show the predicted effect, multiplicative fudge factors ranging from 0 to 1, such that for a value of zero there is no Woodward effect, are proposed by Buldrini.  No estimation is presented of what the value of the fudge factors should be. 

Now a new condition is added that the effect won't manifest itself unless the drive is simultaneously accelerated by external power.    When did this condition first appear in Woodward's publications?
What magnitude of “bulk” acceleration is large enough  according to Woodward?

It is elucidating that we get now a recognition by Woodward that:

<<simply charging and discharging capacitors will not produce mass fluctuations. >>

This effectively recognizes that solely replacing fluctuations in the rest energy by the fluctuations in the electric power input to a capacitor is not just "overly optimistic" but invalid.  See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260795#msg1260795  He now adds the extra condition that the device needs to be simultaneously accelerated to an unspecified large enough “bulk” acceleration.  The new experimental setup used by Woodward involves the linear (in voltage) piezoelectric effect and the quadratic (in voltage) electrostrictive effect in a stack of PZT disc capacitors.
This above, Dr. Rodel; was brought to my attention in another forum, because you are here slandering a good man and accusing him of moving the goal posts, saying the predicted effect didn't show up, using fudge factors when in fact no thrust magnitude prediction had been made for good reason, and of creating "new conditions" when in fact these conditions are in the peer reviewed literature going back almost 20 years now.  If I'm wrong and you've been unusually restrained you have my apology but it looks like you're acting very typically for this sort of venue.

Mr. Stahl,  you have now raised this to another, serious level.  You have now stated  << you are here slandering a good man >>.  Slander is "the action or crime of making a false spoken statement damaging to a person's reputation"
I asked a question, whether goal posts where being moved, regarding the appearance of "bulk acceleration," which I had not seen previously.  The explanation was given by a number of people in this forum, regarding what you call the MLT type of thruster that motivated my question.  I have not questioned those answers and I have moved over to other issues as I always made clear that I had no other interest than the NASA experiments.  At that time I thought that Dr. White's slide 40 (on the "MLT") was an experiment run at NASA.

You should know all this by now, so you are the one making a completely unfounded charge. 

You should retract your unfounded charge that I slandered anybody.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 09:23 pm
Quote
Hold tha damn phone.

Am I correct in my interpretation that you or some group of people you know is actively attempting to Sheppard Woodward's work all the way through to commercialization??
Yes.

And where can a space geek go to keep abreast of such developments?
I'll splash news onto a couple forums when we make some headway, but as I stated the other day, I am still looking for a pair of Principle Investigators to run the UFG MET project and to run the Rad Hardening project.  Both grants need PhD's to run them who demonstrate aptitude for the task.  The first (the thruster) is very complex.  We don't need nor even want a "believer" in the commons sense and are better suited with a skeptic, but in any case we need folks who are able to understand the complex details of the setup, as well as construction and a handful of other things.  A physicist could do it but I'd rather have an able engineer.

The second project probably needs a plasma physicist who can model a spacecraft flying through the Van Allen Belt on COMSOL, and most physicists don't use engineering programs so that position is hard to fill as well.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 09:30 pm
Do people get a sense of a moving goal post ? .  When experiments do not show the predicted effect, multiplicative fudge factors ranging from 0 to 1, such that for a value of zero there is no Woodward effect, are proposed by Buldrini.  No estimation is presented of what the value of the fudge factors should be. 

Now a new condition is added that the effect won't manifest itself unless the drive is simultaneously accelerated by external power.    When did this condition first appear in Woodward's publications?
What magnitude of “bulk” acceleration is large enough  according to Woodward?

It is elucidating that we get now a recognition by Woodward that:

<<simply charging and discharging capacitors will not produce mass fluctuations. >>

This effectively recognizes that solely replacing fluctuations in the rest energy by the fluctuations in the electric power input to a capacitor is not just "overly optimistic" but invalid.  See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260795#msg1260795  He now adds the extra condition that the device needs to be simultaneously accelerated to an unspecified large enough “bulk” acceleration.  The new experimental setup used by Woodward involves the linear (in voltage) piezoelectric effect and the quadratic (in voltage) electrostrictive effect in a stack of PZT disc capacitors.
This above, Dr. Rodel; was brought to my attention in another forum, because you are here slandering a good man and accusing him of moving the goal posts, saying the predicted effect didn't show up, using fudge factors when in fact no thrust magnitude prediction had been made for good reason, and of creating "new conditions" when in fact these conditions are in the peer reviewed literature going back almost 20 years now.  If I'm wrong and you've been unusually restrained you have my apology but it looks like you're acting very typically for this sort of venue.

Mr. Stahl,  you have now raised this to another, serious level.  You have now stated  << you are here slandering a good man >>.  Slander is "the action or crime of making a false spoken statement damaging to a person's reputation"
I asked a question, whether goal posts where being moved, regarding the appearance of "bulk acceleration," which I had not seen previously.  The explanation was given by a number of people in this forum, regarding what you call the MLT type of thruster that motivated my question.  I have not questioned those answers and I have moved over to other issues as I always made clear that I had no other interest than the NASA experiments.  At that time I thought that Dr. White's slide 40 (on the "MLT") was an experiment run at NASA.

You should know all this by now, so you are the one making a completely unfounded charge. 

You should retract your unfounded charge that I slandered anybody.
You're entirely right.  Slander was a very unfortunate choice of words.  Slander is always intentional IIUC, and my point was certainly, that you mischaracterized this issue out of ignorance rather than malice.  I do not think you intended any malice, but rather; that you are demonstrating a very common and understandable skepticism.  Lets be candid shall we?  Not one in 100 schemes like what we're here talking about is worth the time to look at.  And nothing against engineers! but almost always they are the result of an engineer pretending to be a physicist.  There used to be an entire site dedicated to this kind of chicanery--"American Antigravity".  So anyone who is interested in the field of advanced propulsion, necessarily needs to develop some skepticism over time.  Almost all this stuff is crackpot!  IMHO, the QVF stuff is crackpot and that's coming from NASA!

So there are no hard feelings here and I really should not have written "slander" as that was just plain wrong and you have my apology.  Please do try to sympathize, I've known Jim for many years now, and he is an excellent man of honor and integrity, due proper respect and a fair shake, which he does not usually get.
Title: Re: EM Drive Developments
Post by: Lar on 10/01/2014 09:37 pm
There is a very serious lack of being excellent to each other in the last several pages. I'm pressed for time so my temptation is to just up and delete all of it. That might throw some good info out.

I would strongly suggest that people try being a lot softer in their word choices, or some mod WILL do just that.

Protip: If you find yourself typing "peanut gallery" you probably ought to rethink your whole approach.

Edit: Note that if you're using the web interface, you have the ability to go in and revise any prior post to improve it. There are a number of posts that would benefit from such editing.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/01/2014 09:48 pm
Fair enough.  Everyone has my apology.
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 09:52 pm
Do people get a sense of a moving goal post ? .  When experiments do not show the predicted effect, multiplicative fudge factors ranging from 0 to 1, such that for a value of zero there is no Woodward effect, are proposed by Buldrini.  No estimation is presented of what the value of the fudge factors should be. 

Now a new condition is added that the effect won't manifest itself unless the drive is simultaneously accelerated by external power.    When did this condition first appear in Woodward's publications?
What magnitude of “bulk” acceleration is large enough  according to Woodward?

It is elucidating that we get now a recognition by Woodward that:

<<simply charging and discharging capacitors will not produce mass fluctuations. >>

This effectively recognizes that solely replacing fluctuations in the rest energy by the fluctuations in the electric power input to a capacitor is not just "overly optimistic" but invalid.  See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260795#msg1260795  He now adds the extra condition that the device needs to be simultaneously accelerated to an unspecified large enough “bulk” acceleration.  The new experimental setup used by Woodward involves the linear (in voltage) piezoelectric effect and the quadratic (in voltage) electrostrictive effect in a stack of PZT disc capacitors.
This above, Dr. Rodel; was brought to my attention in another forum, because you are here slandering a good man and accusing him of moving the goal posts, saying the predicted effect didn't show up, using fudge factors when in fact no thrust magnitude prediction had been made for good reason, and of creating "new conditions" when in fact these conditions are in the peer reviewed literature going back almost 20 years now.  If I'm wrong and you've been unusually restrained you have my apology but it looks like you're acting very typically for this sort of venue.

Mr. Stahl,  you have now raised this to another, serious level.  You have now stated  << you are here slandering a good man >>.  Slander is "the action or crime of making a false spoken statement damaging to a person's reputation"
I asked a question, whether goal posts where being moved, regarding the appearance of "bulk acceleration," which I had not seen previously.  The explanation was given by a number of people in this forum, regarding what you call the MLT type of thruster that motivated my question.  I have not questioned those answers and I have moved over to other issues as I always made clear that I had no other interest than the NASA experiments.  At that time I thought that Dr. White's slide 40 (on the "MLT") was an experiment run at NASA.

You should know all this by now, so you are the one making a completely unfounded charge. 

You should retract your unfounded charge that I slandered anybody.
You're entirely right.  Slander was a very unfortunate choice of words.  Slander is always intentional IIUC, and my point was certainly, that you mischaracterized this issue out of ignorance rather than malice.  I do not think you intended any malice, but rather; that you are demonstrating a very common and understandable skepticism.  Lets be candid shall we?  Not one in 100 schemes like what we're here talking about is worth the time to look at.  And nothing against engineers! but almost always they are the result of an engineer pretending to be a physicist.  There used to be an entire site dedicated to this kind of chicanery--"American Antigravity".  So anyone who is interested in the field of advanced propulsion, necessarily needs to develop some skepticism over time.  Almost all this stuff is crackpot!  IMHO, the QVF stuff is crackpot and that's coming from NASA!

So there are no hard feelings here and I really should not have written "slander" as that was just plain wrong and you have my apology.  Please do try to sympathize, I've known Jim for many years now, and he is an excellent man of honor and integrity, due proper respect and a fair shake, which he does not usually get.

Thank you for your very gracious reply.  My only interest in this thread is to understand the NASA results.  I have enjoyed very much the technical discussion, including the latest one concerning axionic Dark Matter. :)
Title: Re: EM Drive Developments
Post by: aero on 10/01/2014 11:06 pm
I was wondering how much energy was stored within the cavity (truncated frustum) so have been (off and on) looking at math for which I have absolutely no background beyond undergraduate course work. Using the input power and Q-factors given, I calculate that the RF wave B field and E field has energy like:

B field range from 0.27 to 0.62 tesla, and
E field range from 80.4 to 184.8 Mv per metre.

Are these reasonable values?

I also calculated that the energy mass of the RF wave ranges from 0.00064 to 0.0034 micrograms.

At this point I don't know what to do with these numbers but maybe someone will find them interesting.

We know from the "Anomalous Thrust ..." report that the COMSOL finite element calculations display a maximum Electric field of 47189 Volts per meter (p. 10, Fig. 14).  I couldn't find any numerical information given for the Electric Field results from COMSOL for the Tapered Cavity.

Also, you may find something useful for comparison in FIg. 16 of the report, for the predicted and actual gain (S21), as attached here (vertical scale: Amplitude (dB); horizontal scale: frequency):

(The numbering convention for S-parameters is that the first number following the “S” is the port where the signal emerges, and the second number is the port where the signal is applied. S21 is a measure of the signal coming out port 2 relative to the RF stimulus entering port 1: the ratio of transmitted to incident voltage signals.  S21 is the forward complex transmission coefficient)

It is apparent that the comparison from this COMSOL analysis to the actual results is not that great...

I could very easily be making an error in my calculations - BUT - Fig. 14 is for the Cannae Cavities while my calculations address the tapered frustum. The paper doesn't give a Q-factor for the Cannae Cavities so I can't do a calculation to check myself with that example. On the other hand, I can do a calculation to estimate what the Q-factor would be if the stored RF wave energy results in an electric field of 4.7189E+04 volts per meter. It is very, very small. Small to the point of being nonsense at ~0.0007.

Correct me where I'm wrong, but the E field energy of the RF wave is given from w = epsilon_sub_o* E^2 where w is energy per unit volume, epsilon_sub_o = 8.85418782 × 10-12 m-3 kg-1 s4 A2 and the Quality factor is energy stored / energy lost per cycle. So I'm taking w = 28 watts with the unit volume of one and calculating much larger values than Fig. 14 shows.
 
Title: Re: EM Drive Developments
Post by: frobnicat on 10/01/2014 11:07 pm
. . .my feeling (as an average mainstream science educated person somehow following the topic) is that the various teams involved in experiments are choosing the wrong methodology and should follow some guidelines for fundamental research experimentalists
I'm sorry but that's not true at all.  Obviously, you have not read the book.

Obviously I have not. This was just a feeling of an anonymous forum contributor, interested but not directly involved and having other focus preventing me to read the 100s pages of scientific literature linked to daily here by good dr Rodal and other contributors. So this could be not true at all. My feeling is true, as a feeling, why I expressed it. I am less aware of Woodward's works, so what I said was possibly totally unfair relative to his (and team's) work and way of doing it. Don't take the volume of words used by me to answer in 100 lines a 1 line remark as an implied pretention of authority.

Right now, in spite of knowing my knowledge of the subject is very limited, I still have the same view about  shortcomings with this line of research : strange methodological priorities. And this is a feeling shared by a number of friends and colleagues somehow "average mainstream science educated person" when informally discussing the topic. While they would be ready to accept a solid experimental result, right now they wouldn't give a kopeck on the whole line of research to yield anything of substance, theoretically or practically, or even give it enough interest to buy a book or even subscribe to the appropriate mailing list. Maybe this is unfair, but it is how mainstream science and tech works, sociologically, when subjects dealing with apparent breaking of momentum/energy conservation are investigated, because so much positive or "almost certainly positive" results claimed for decades and still not a single rock solid self contained experiment confirming there is something at all. That and no need for the theories backing such possibilities when dealing with day to day usual reality (from action/reaction in mechanical engineering to hadron jets reconstruction in colliders, all in perfect agreement with standard theories so far. Alright, muonic hydrogen anomalies, dark sector etc, we still have plenty ongoing mysteries...).

Also I should note, as a French citizen, that we (French) are always criticizing everything, it seems we are never happy with any given situation and we should always have an opinion on a way things should be better. This "lesson giver" bias is also a very common trait on online forums, but we French people have raised that to a standard of living. When I say "dr White et al have a poor methodology" you should not hear "they are incompetent crooks" but rather "I would appreciate a shift in their focus toward a more definite answer as to whether there is an effect at all" as all French techies would interpret the statement from its brutal formulation. You might say, they are already striving all they can to get to this definite answer, but this is not my impression, my impression is that they so hardly believe in a positive answer that it gets in the way of getting an answer, that could be negative. This would not be the first time that very bright people follow a line of research that, cruelly, proves to be a dead end. Some of the finest minds of earth have dedicated decades on string theory, and some other of the finest minds of earth think this is leading nowhere because it is not predicting anything more and not falsifiable, and while this was interesting to investigate we should shift focus on other approaches.

Anyway, I am not expecting expressing this view here on this forum to change the mind of really involved persons, free to work as they wish (within their limited budgets and other constraints of reality) and that's good. May be the people they have to answer for ask for different kind of indication of credibility. But this very sceptical perception by a general scientific population (at least French, and caprine, that I can testify) might become a handicap in the long run, no ?

They hope and work to have a solid confirmation. But what if it doesn't come in 10 years, in 20 years ? The bet is that it comes soon ?

Quote
Quote
please produce a complete detailed description of one single self contained airtight device, thermally isolated, energetically isolated, electromagnetically shielded, that is reproducible and will guarantee anyone caring to follow the instructions to observe a thrust/power effect better than 1/c for a few seconds
While I understand and appreciate what you're trying to do, all i can say in few words is, you are putting out criteria that are unreasonable and unnecessary.

I do also appreciate your contributions in this thread. Don't know if this is the place to do real serious science but great to exchange different views.

All I can say in a few word is I strongly disagree ahem. I have a different view.
This should be the top priority.
It is not unreasonable : Brito, Marini and Galian did a pretty good job at isolating thermally and energetically a device in an airtight configuration and on a well behaved balance. Sure this must be a pain to "vent" the thermal energy between the sessions, but this gives a very credible result. Should their result have been positive it would have had a rather serious impact not only for my little person but for the scientific community at large, even if not in vacuum. Note also that their self contained design would be "easily" amenable to a check in a vacuum chamber, had their result been positive and worth of it.
It is necessary : because a rock solid positive, or at least a signal that couldn't be handwaved away by sceptics as "must be thermal or something" is the only way to convince some labs beyond the aerospace to investigate. And if such effect is possible it would be so much beyond "down to space" considerations, this needs to be investigated as fundamental science.

Quote
  In the words of Dr. Dennis Bushnell, NASA's Chief Scientist and point man for all propulsion and power exploration like these, the reason NASA is not biting is that they don't have anyone able to judge the theory.
And people able to judge the theory wont be interested to even read the book before there are clear enough signals in clean enough experimental setups (see above -> necessary).

Quote
The experimental setup is not the trouble.  Since they cannot do a real evaluation of theory, what they've asked for is more thrust, which is what Jim is working on.

That makes no sensible sense to me. In this context this would be an application driven research ? So the trouble is the experimental setup. Why should they care about theories ? If the effect is hinting at being anything like it says it is, then pour the money and hire the third party experimentalists to do an all or nothing confirmation of any real effect at all. Even if all it takes is a mW thruster mounted on an atomic force microscope cantilever to get a few pN of thrust, just to see it's real. Then make phenomenological model. Then build better/bigger devices and see if it fits such or such ground breaking theory.
Even if the fact to pursue a higher thrust might contribute to show this is not a real effect and therefore allow for a progress, my point is that putting the focus on that is not the best way to assert the reality of any effect at all.
Again, the "this is impossible" hypothesis appears not well accommodated by the strategy. The way to conduct the experiments should be neutral as to the reality of the effect. Not in a spirit of "in all likelyhood this is possible, let's see how" but "is it possible or not". I'm speaking from a point of view of fundamental research, which this line of research should be considered part of, because of its principal consequences, which are not better probes to Saturn, but complete rewriting of physics.

Sorry, NASA is great, probes are great, I'm a space enthusiast (wouldn't care to be here otherwise), but this may not be the ideal context to assert the reality of such effect. It's all right, reality is not always as we want.

I read and appreciate the rest of your post, that answer some of the above remarks.
Will answer also, time permitting (yeah yeah, I use too much words...)
Sorry to flood with my rants.

will try to be constructive and bring some numbers to this axion craze (might be 6 order of magnitude off target...)
Title: Re: EM Drive Developments
Post by: Rodal on 10/01/2014 11:48 pm
I was wondering how much energy was stored within the cavity (truncated frustum) so have been (off and on) looking at math for which I have absolutely no background beyond undergraduate course work. Using the input power and Q-factors given, I calculate that the RF wave B field and E field has energy like:

B field range from 0.27 to 0.62 tesla, and
E field range from 80.4 to 184.8 Mv per metre.

Are these reasonable values?

I also calculated that the energy mass of the RF wave ranges from 0.00064 to 0.0034 micrograms.

At this point I don't know what to do with these numbers but maybe someone will find them interesting.

We know from the "Anomalous Thrust ..." report that the COMSOL finite element calculations display a maximum Electric field of 47189 Volts per meter (p. 10, Fig. 14).  I couldn't find any numerical information given for the Electric Field results from COMSOL for the Tapered Cavity.

Also, you may find something useful for comparison in FIg. 16 of the report, for the predicted and actual gain (S21), as attached here (vertical scale: Amplitude (dB); horizontal scale: frequency):

(The numbering convention for S-parameters is that the first number following the “S” is the port where the signal emerges, and the second number is the port where the signal is applied. S21 is a measure of the signal coming out port 2 relative to the RF stimulus entering port 1: the ratio of transmitted to incident voltage signals.  S21 is the forward complex transmission coefficient)

It is apparent that the comparison from this COMSOL analysis to the actual results is not that great...

I could very easily be making an error in my calculations - BUT - Fig. 14 is for the Cannae Cavities while my calculations address the tapered frustum. The paper doesn't give a Q-factor for the Cannae Cavities so I can't do a calculation to check myself with that example. On the other hand, I can do a calculation to estimate what the Q-factor would be if the stored RF wave energy results in an electric field of 4.7189E+04 volts per meter. It is very, very small. Small to the point of being nonsense at ~0.0007.

Correct me where I'm wrong, but the E field energy of the RF wave is given from w = epsilon_sub_o* E^2 where w is energy per unit volume, epsilon_sub_o = 8.85418782 × 10-12 m-3 kg-1 s4 A2 and the Quality factor is energy stored / energy lost per cycle. So I'm taking w = 28 watts with the unit volume of one and calculating much larger values than Fig. 14 shows.
Thank you for pointing out that the Q factor for the Cannae drive is not given. I had forgotten that.
This is my understanding:

Cannae drive: E field data is provided.  No Q factor provided.
Tapered Cavity: E field numerical data range not provided.  Q factor provided.

________________

These are my calculations for the Maximum power  density in ("Teflon") PTFE dielectric resonator for Cannae device (notice the frequency  "f" in the calculation):

MaximumPower = 2 Pi f (E^2) (permittivity of free space) (epsilon')

Taking the

maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m , and the given

frequency of 935 MHz, it follows (for the Teflon PTFE dielectric resonator) that:


MaximumPower per unit volume [W/m^3] = 2 Pi (935*10^6 1/s) (( 4.7189*10^4)^2) (8.85418782*10^(-12)) (2.1)

MaximumPower per unit volume (in the dielectric resonator)~  243 W/cm^3
Title: Re: EM Drive Developments
Post by: raketa on 10/02/2014 12:14 am
What you're describing is one of 5 plans in progress for the DARPA grant process.

DARPA grants are very odd compared to other grants because they require the whole TRL process.  They generally cover TRL6 and 7 in 2 phases, but they require the TRL-1-5 history, the phase 1 TRL6 plan in detail, the follow on TRL7 plan in detail (though they expect changes after phase 1), the plan for the jump to TRL8 commercialization including whom will build the product and a market analysis of who would pay for it.  What you're taking about is part of the TRL9 analysis, which is to provide Dragon with an M-E trunk that can take it to the Moon and Mars.  This is one of 5 early "low thrust" applications, but the trunk needs to be completely refitted so this is not a cheap nor simple issue.

What is cheap is to catch a free ride to orbit for a nanosat, but this still requires miniaturization.  And really you don't want to send stuff to orbit without paying for that step because that is the step where radiation hardening takes place, and where the actual FOM's for future spacecraft with all their working systems come from.  You want the grant to pay for the miniaturization so you have it ready to go to market.  In our case, miniaturization does not happen until phase 2/TRL7, but this is quite normal and the electrical engineering for this can be shopped out to literally dozens of places so there is little challenge there save how it affects delivery times of other portions of the project.
Got it, thank you for explaining process.
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 12:16 am
will ... bring some numbers to this axion craze ..

Here is some Axion music craze, in the interim  (AXION ESTI ODYSSEAS ELITIS ):

http://www.youtube.com/watch?v=T11Syk_-Ba4&list=RDT11Syk_-Ba4#t=38
Title: Re: EM Drive Developments
Post by: raketa on 10/02/2014 01:03 am
Making Starships and Stargates: The Science of Interstellar Transport and Absurdly Benign Wormholes (Springer... by James F. Woodward (Dec 14, 2012)
This is the book you suggest to read.
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 01:07 am
I was wondering how much energy was stored within the cavity (truncated frustum) so have been (off and on) looking at math for which I have absolutely no background beyond undergraduate course work. Using the input power and Q-factors given, I calculate that the RF wave B field and E field has energy like:

B field range from 0.27 to 0.62 tesla, and
E field range from 80.4 to 184.8 Mv per metre.

Are these reasonable values?

I also calculated that the energy mass of the RF wave ranges from 0.00064 to 0.0034 micrograms.

At this point I don't know what to do with these numbers but maybe someone will find them interesting.

We know from the "Anomalous Thrust ..." report that the COMSOL finite element calculations display a maximum Electric field of 47189 Volts per meter (p. 10, Fig. 14).  I couldn't find any numerical information given for the Electric Field results from COMSOL for the Tapered Cavity.

Also, you may find something useful for comparison in FIg. 16 of the report, for the predicted and actual gain (S21), as attached here (vertical scale: Amplitude (dB); horizontal scale: frequency):

(The numbering convention for S-parameters is that the first number following the “S” is the port where the signal emerges, and the second number is the port where the signal is applied. S21 is a measure of the signal coming out port 2 relative to the RF stimulus entering port 1: the ratio of transmitted to incident voltage signals.  S21 is the forward complex transmission coefficient)

It is apparent that the comparison from this COMSOL analysis to the actual results is not that great...

I could very easily be making an error in my calculations - BUT - Fig. 14 is for the Cannae Cavities while my calculations address the tapered frustum. The paper doesn't give a Q-factor for the Cannae Cavities so I can't do a calculation to check myself with that example. On the other hand, I can do a calculation to estimate what the Q-factor would be if the stored RF wave energy results in an electric field of 4.7189E+04 volts per meter. It is very, very small. Small to the point of being nonsense at ~0.0007.

Correct me where I'm wrong, but the E field energy of the RF wave is given from w = epsilon_sub_o* E^2 where w is energy per unit volume, epsilon_sub_o = 8.85418782 × 10-12 m-3 kg-1 s4 A2 and the Quality factor is energy stored / energy lost per cycle. So I'm taking w = 28 watts with the unit volume of one and calculating much larger values than Fig. 14 shows.
Thank you for pointing out that the Q factor for the Cannae drive is not given. I had forgotten that.
This is my understanding:

Cannae drive: E field data is provided.  No Q factor provided.
Tapered Cavity: E field numerical data range not provided.  Q factor provided.

________________

These are my calculations for the Maximum power  density in ("Teflon") PTFE dielectric resonator for Cannae device (notice the frequency  "f" in the calculation):

MaximumPower = 2 Pi f (E^2) (permittivity of free space) (epsilon')

Taking the

maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m , and the given

frequency of 935 MHz, it follows (for the Teflon PTFE dielectric resonator) that:


MaximumPower per unit volume [W/m^3] = 2 Pi (935*10^6 1/s) (( 4.7189*10^4)^2) (8.85418782*10^(-12)) (2.1)

MaximumPower per unit volume (in the dielectric resonator)~  243 W/cm^3

If you divide your

<<E field range from 80.4 to 184.8 Mv per metre>>

by the square root of the angular frequency for the Cannae drive:

 Sqrt[ 2 Pi (935*10^6 1/s) ] = 76647.1

one gets:

E field range from 1049 to 2411 Volts per meter.

which is not too far from the COMSOL calculations (there is also an uncertainty due to the Volume)


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
While for the tapered cavity

If you divide your

<<E field range from 80.4 to 184.8 Mv per metre>> by the actual square root of the angular frequency

 Sqrt[ 2 Pi (1932.6*10^6 1/s) ] = 110195

one gets

E field range from 730 to 1677 Volts per meter (there is also an uncertainty due to the Volume)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 01:32 am
In the words of Dr. Dennis Bushnell, NASA's Chief Scientist and point man for all propulsion and power exploration like these, the reason NASA is not biting is that they don't have anyone able to judge the theory.  The experimental setup is not the trouble.

It has been asserted and supported that the spurious signals associated with the experimental apparatus are a flaw in the experimental procedure which should be accomodated.  Attempts to calculate the magnitude of some kinds of the spurious forces depend upon dimensional data of the apparatus, data which has been deliberately kept under wraps.

Analysis of the theory itself has suggested substantial flaws, with several attempts to propose more and more esoteric phenomena instead of the mass fluctuations which are the foundation of Woodward's theory.  In fact, some posters have suggested that the experiment will be sufficient proof of the anomalous thrusts, regardless of the correctness of the theory.

Many posters here have provided the caveat of how they don't have the time to understand and critique the theory, but go on to assert, without support, the soundness of the theory, or to propose yet another far fetched special effect of physics in support of the theory.

Bottom line: If NASA doesn't understand the theory, it should not pretend to support reseach into it. Should your credibility be an important asset to you, please link Dennis Bushnell's comment about their scientific ignorance in this arcane but necessary field.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 01:32 am


Ron, I'm new to this site, but it is my impression is that it would help if you would also include the author of the quotes...

And I'm partly new, but mostly older.  Pretty sure Ron Stahl didn't say "     ". do what I do, and include a portion of his remarks in the HTML quote, so we can have a better handle on what part of his comment you are referring to.

Oh. E dal dipartimento di "Solo Dicendo", che lo scorso Martini tuo mancava di sostanza, diciamo.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 01:33 am
Yes, that was my opinion he quoted.  And I'm sorry if that truth seems to annoy but it is the truth.

Sorry bud.  Your opinion does not become truth in one unsubstantiated sentence. [Waves hand.]  I'm an American. [Waves hand.]  Your cognitively infiltrative remarks don't work on me.

Quote from: Ron Stahl
...anyone who has been around a few years on one or more of these boards knows how opinionated and predictable these forums are.

You knew they were going to start talking about axions, and you you didn't warn us?  This is borderline nonsense.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 01:33 am

quite funny indeed. ...

Here however we have a clear demonstration of how rational choice theory often fails. It is always complicate to justify rationally the behaviour of individuals wasting their time to say "there is nothing to say here because you are all wrong and uninteresting".

Due punti per Gryfindor.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 01:33 am
Outside of this thread and forum you would be considered an anomaly.

Well, his martinis are an anomaly.  Dunno about the man, but hey.  I'm being as "excellent" to him as I can!
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 01:34 am
they wouldn't give a kopeck two bits on the whole line of research...

Fixed that for ya.  Once I get started, oooo, it's hard to stop. (http://www.youtube.com/watch?v=8ANMN17-kt8)

Seriously, totally excellent post.  Wish I didn't have to depend on the translator.  Will listen harder to next week's "News in Slow French", as I try to learn your language!
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 02:00 am
Oh. E dal dipartimento di "Solo Dicendo", che lo scorso Martini tuo mancava di sostanza, diciamo.

E dal dipartimento di "Solo Dicendo", mai ti ho promesso un giardino di rose Martini real

http://www.annarbor.com/entertainment/food-drink/the-cocktail-clash/
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 02:33 am
......
And people able to judge the theory wont be interested to even read the book before there are clear enough signals in clean enough experimental setups (see above -> necessary).
......

@frobnicat,  also,

NASA has some outstanding physicists.  For example, John C. Mather has been awarded the Nobel Prize in Physics in 2006 (for his work on the Cosmic Background Explorer Satellite (COBE) with George Smoot (MIT).

Mather is at the NASA's Goddard Space Flight Center (GSFC) in Maryland and he is also an adjunct Professor of Physics at the University of Maryland.

http://en.wikipedia.org/wiki/John_C._Mather
Title: Re: EM Drive Developments
Post by: frobnicat on 10/02/2014 08:34 am
Rumor is, Stennis, JPL, Glenn and one of the National Labs are all considering replications of the Eagle work, and this all from a little conference paper!  That's quite a reaction!
 
Yes it is, that is good news and may make some of my previous remarks partly irrelevant.

Quote
And let me note again, that when you are not familiar with the details of what has been published on this subject, to complain there has not be what you want published, is a little silly.  Read Woodward's book.  It's a fascinating read meant for engineers.  I promise it is fun or I owe you a beer.
What we can contribute scientifically on this thread is limited by our respective (and respectable) abilities and time. It might be silly to try to contribute to more than a decade of work before diving in all every single publication. Dr Rodal made a lot of effort to collect and summarize part of this line research for a wider audience. This is useful. As for Woodward's book, I'm not looking for fun (though that couldn't hurt) but for facts. Time permitting I will try to find and read it. If I don't find it factual you owe me a bear.

At one time I was ready to unsheathe my gnuplot and make a few scatterplots of reported thrusts versus sidereal time to see if there is correlation that could indicate a coupling of device with a flow or a particular local (at least solar system wide) frame of reference. I don't know of any attempt at doing that, that may be completely off topic in the views of the leading theories of Woodward, White et al, but since those theories are far from verification other mechanisms than thought may be at play (assuming a real effect). Asked here (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263885#msg1263885) and there (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263934#msg1263934) if such sidereal time was ever taken into account, appears no, or no one knows (or I missed an answer on that ?)
Well, probably it would be a negative, but that could be the kind of small third party hobbyist level lateral investigation that could stand a little chance of helping the topic... In this particular case, I complain timestamped experimental data in readable format are either not publicly available or very hard to find. If any-one knows something like a list of a dozen (preferably 100s) of timestamped on/off thrust sessions results. I can't believe dr White (anomalous thrust...) did only 5 or 6 30s sessions, said "ok we got a signal" and switched to another device ... Even at hobbyist level of funding, we would expect more logged and published data points from this kind of experiments.

If anyone points me to such collected rich enough dataset I would be delighted to test my little hypothesis.

Quote
Quote from: frobnicat
So far my feeling is that the "propellantless propulsion proponents" are doing a really great job at NOT convincing an (admittedly already reluctant) mainstream science community that there is any effect at all.
Agreed, but those who have read the book are starting to make their sentiments known.  Sometimes these things take time.  The book is not even 2 years old.
Understood.

Quote
Quote
But it seems strange to me (and my guess to a majority of scientists and engineers), if effect is real then it is worth fundamental physics methodology, not necessarily billions $ but at least complete open access to blueprints, complete experimental datafiles (including preliminary adjustments and settings) and not just snapshots of a few screens. . .
All of Woodward's data has been given to Creon Levit, NASA's main comp guy at Ames.  Also this summer, Woodward upgraded his instrumentation to Labview, so the data will be easier to obtain and digest in the future.  I believe that data acquisition system goes online in just another week or so.
Progress in the process. Great news.

Quote
Quote
. . .can't they dump the raw values of those instruments on some disk?
As noted, all what you're asking for save the self-contained issue has previously been addressed, and you should not presume Eagle hasn't done the same.  NASA has its own analysts and they don't need unpaid peanut galleries to make decisions.  Nothing against this forum, but online engineering forums are notoriously ill-mannered and dysfunctional when it comes to real analysis.  You should not expect to see that kind of thing here.  Dennis and Creon are top notch guys.  Sometimes you just need to wait for the hammer to fall.

ok

still considering that "self-contained issue" is central and should be addressed rather sooner than later for reasons expressed at length in previous posts.

Best.


Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 11:53 am
...
At one time I was ready to unsheathe my gnuplot and make a few scatterplots of reported thrusts versus sidereal time to see if there is correlation that could indicate a coupling of device with a flow or a particular local (at least solar system wide) frame of reference. I don't know of any attempt at doing that, that may be completely off topic in the views of the leading theories of Woodward, White et al, but since those theories are far from verification other mechanisms than thought may be at play (assuming a real effect). Asked here (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263885#msg1263885) and there (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1263934#msg1263934) if such sidereal time was ever taken into account, appears no, or no one knows (or I missed an answer on that ?)
Well, probably it would be a negative, but that could be the kind of small third party hobbyist level lateral investigation that could stand a little chance of helping the topic... In this particular case, I complain timestamped experimental data in readable format are either not publicly available or very hard to find. If any-one knows something like a list of a dozen (preferably 100s) of timestamped on/off thrust sessions results. I can't believe dr White (anomalous thrust...) did only 5 or 6 30s sessions, said "ok we got a signal" and switched to another device ... Even at hobbyist level of funding, we would expect more logged and published data points from this kind of experiments.

If anyone points me to such collected rich enough dataset I would be delighted to test my little hypothesis.

I am not aware of anyone taking into account sidereal time.  I would very much appreciate if you could take the time to plot the reported thrusts versus sidereal time [if possible with the data at hand] to see if there is correlation that could indicate a coupling of the devices with a flow or a particular known frame of reference.
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 12:03 pm
Quote
Rumor is, Stennis, JPL, Glenn and one of the National Labs are all considering replications of the Eagle work, and this all from a little conference paper!  That's quite a reaction!
 
Yes it is, that is good news and may make some of my previous remarks partly irrelevant.

It is not a rumor. It is not news.    It is not a reaction following a "a little conference paper". 

It doesn't make any of your previous remarks irrelevant.

Actually the information was already in that same conference paper itself, and this was Eagleworks plan of action

p. 21 of "Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum"

<<The current plan is to support an IV&V test campaign at the Glenn Research Center (GRC) using their low thrust torsion pendulum followed by a repeat campaign at the Jet Propulsion Laboratory (JPL) using their low thrust torsion pendulum. The Johns Hopkins University Applied Physics Laboratory has also expressed an interest in performing a Cavendish Balance style test with the IV&V shipset.>>

A number of people have discussed this previously in this thread.  Information has been provided in this thread to support that the highest priority should be to test at the Johns Hopkins University Applied Physics Laboratory because they are the only ones (of those mentioned) that are proposing to use a Cavendish Balance style test, as Brito, Marini and Galian used to nullify the tested "MLT" type of thruster and Brito et.al.'s reference to Woodward's theory, and as the classical experiments on gravitation (inverse square law) and Casimir force were conducted.   
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 01:04 pm
...mai ti ho promesso...

Bummin'.  Was lookin' forward to it.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 01:05 pm


John C. Mather

Please don't tell me the "C" stands for "Cotton".
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 01:05 pm
Si je ne trouve pas que ce fait vous me devez un ours.

Ex-squeeze me?

Quote
It might be silly to try to contribute to more than a decade of work before diving in all every single publication.

Seriously, tho, I disagree with this. 

Notice how in this thread, "the book" is now being referred to as the ultimate, and probably the only source of "true" information on the theory.  It cannot be the case that the previous twenty years or so of theoretical work, some of it peer reviewed, is supplanted by this new book.

"Asked here and there if such sidereal time was ever taken into account", and asked there and here if other dimensional info and related specifications could be shared, you find again and again, no response.  I bumped the other thread, so that the interested parties could see, in part, that this sort of approach has been going on for years.  The approach being one of not answering questions, and one of pointing to other publications as if to imply that those other pubs would reveal all of the pertinent theory. 

They don't.

Quote
If anyone points me to such collected rich enough dataset I would be delighted to test my little hypothesis.

You're a better hobbyist than I am, Gunga Din.  But I can read a chart, and it would be interesting to see your results charted with the data at hand.
Title: Re: EM Drive Developments
Post by: birchoff on 10/02/2014 02:04 pm
Notice how in this thread, "the book" is now being referred to as the ultimate, and probably the only source of "true" information on the theory.  It cannot be the case that the previous twenty years or so of theoretical work, some of it peer reviewed, is supplanted by this new book.

I do not believe anyone is considering the book to be the only source of TRUE information. On the contrary, those of us who have read the book, believe it contains answers and context that we have seen asked on this thread. In addition for those that are trying to get up to speed on everything that has been done both theoretically and experimentally up to 2012 then this book is in my mind the best way to do that. Jim does a very very good job of including references to all the published papers that he uses to support his arguments along with references to all the GR equations he uses to get to his derivation. He also includes references to all the papers he has published experimental results in. And to top it off it gives you a peak into the mind of the person leading this charge for the last 14+ years.

So I say again it is not the only source of TRUE information but it is the BEST source of COMPLETE information. Anyone who still wants to honestly critique Jim's work after pouring over Jim's book is still welcome to do so. Something tells me critics will still have issues they feel need to be raised after reading it.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/02/2014 02:17 pm
Yes, the basic issue is whether rest mass can change at the particle level and not just as a rearrangement of kinetic energy.
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 02:24 pm
Yes, the basic issue is whether rest mass can change at the particle level and not just as a rearrangement of kinetic energy.
Excellent way to state it.   You worded it better than I did.
Has this been addressed with equations in some book or some paper?
If anybody can answer this fine.  If it cannot be answered that's fine too, I'm just interested in what are the possible causes of the NASA "anomalous thrust" experiments.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 02:43 pm
I do not believe anyone is considering the book to be the only source of TRUE information.

Frustrated as I am about the debate, I end up not wording my comments at carefully as I should.  I did say "probably the only source of info".  But still, allow me to rephrase:

Quote from: JF
Notice how in this thread, "the book" is now being referred to as if it were the ultimate, and probably the only source of "true" information on the theory.  It cannot be the case that the previous twenty years or so of theoretical work, some of it peer reviewed, is supplanted by this new book.

I include a scan of pages 33-35 of Woodward's "Stargate" book, claiming fair use for educational purposes.

I have relied upon a friend of mine with far better grounding in the math and GR theory, for his opinion that these few pages are not a complete derivation of the operating principles of the device.

Break it down to my level, ok?

Algebraic and undergrad calculus.
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 02:45 pm
I do not believe anyone is considering the book to be the only source of TRUE information.

Frustrated as I am about the debate, I end up not wording my comments at carefully as I should.  I did say "probably the only source of info".  But still, allow me to rephrase:

Quote from: JF
Notice how in this thread, "the book" is now being referred to as if it were the ultimate, and probably the only source of "true" information on the theory.  It cannot be the case that the previous twenty years or so of theoretical work, some of it peer reviewed, is supplanted by this new book.

I include a scan of pages 33-35 of Woodward's "Stargate" book, claiming fair use for educational purposes.

I have relied upon a friend of mine with far better grounding in the math and GR theory, for his opinion that these few pages are not a complete derivation of the operating principles of the device.

Break it down to my level, ok?

Algebraic and undergrad calculus.

Thank you for posting these pages, but I don't see new equations in these particular pages that did not appear in previous papers.   Please don't answer that there are new words.  This is not meant as a criticism for writers using words, I used lots of words here too. When there are equations, I prefer to just go with equations -that's my personal viewpoint. If I am missing some new equation, I would appreciate it being pointed out. Thank you.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/02/2014 03:35 pm
As you probably realize, if the sources of the "external" accelerating force are taken into account, the second term still vanishes.
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 03:40 pm
As you probably realize, if the sources of the "external" accelerating force are taken into account, the second term still vanishes.
Agreed.  Of interest, in the paper that is used as a reference for those equations, Sciama himself pointed out that:.

Top of p.38, in "ON THE ORIGIN OF INERTIA", D. W. Sciama (Received 1952 August 20), Royal Astronomical Society, No. 1, 1953

<<Since the change of rho with time is very small, the gravelectric part of the field is approximately >>

The derivation of the field equation containing A) the second derivative with respect to time of Eo ("the local proper energy density") and B) the square of the first derivative with respect to time of Eo ("the local proper energy density"),

* is not in these pages attached by John. John could you also attach those pages? Thanks
* is not in any of Sciama's paper, to my knowledge.  It is the derivation, justification and final result  (of the 2nd Derivative with respect to time of  Eo ("the local proper energy density") ) that is at stake. 

Sciama lived until December 19, 1999

Did Sciama write a paper agreeing with or commenting on placing significance on the above mentioned terms A and B, that transient fluctuations in the local proper energy density could be used for (A) propellant-less propulsion and (B) wormhole stabilization ?  Did Sciama agree that local conservation of momentum could thus be moot (using A)?

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/02/2014 03:43 pm
Quote
The experimental setup is not the trouble.  Since they cannot do a real evaluation of theory, what they've asked for is more thrust, which is what Jim is working on.

That makes no sensible sense to me. In this context this would be an application driven research ? So the trouble is the experimental setup. Why should they care about theories ? If the effect is hinting at being anything like it says it is, then pour the money and hire the third party experimentalists to do an all or nothing confirmation of any real effect at all. Even if all it takes is a mW thruster mounted on an atomic force microscope cantilever to get a few pN of thrust, just to see it's real. Then make phenomenological model. Then build better/bigger devices and see if it fits such or such ground breaking theory.
Even if the fact to pursue a higher thrust might contribute to show this is not a real effect and therefore allow for a progress, my point is that putting the focus on that is not the best way to assert the reality of any effect at all.
Again, the "this is impossible" hypothesis appears not well accommodated by the strategy.
I think we're talking past each other because you're not familiar with what I've been relating, which is Woodward's work.  I have little interest in the work at Eagle because I know the QVF hypothesis is wrong.  The Eagle work interests me in as much as it may be stumbling across M-E evidence, but this would be by mistake.  For example, it works only with a  dielectric and during switching transients which bear enough in common with an AC signal they can produce decent thrust.  But the DC signal doesn't do this.

Keep in mind the contrast here.  Woodward's scheme does not violate conservation.  There's nothing "new" in his work, nor any contradictions with conventional science.  In fact, while explaining his work, he very ably answered questions about the classical and semi-classical electron models we've had for decades, and as I said, he deserves a Nobel for this alone.  I'm not suggesting you skip ahead, but chapter 7 is a nail-biter.

In any event, I agree the "this is impossible" kinds of statements are unhelpful.  And the statement that QVF violates conservation is not really true.  That's a distraction fallacy intended to be later explained away as one becomes aware of what QVF is proposing.  However what is not a distraction is that QVF violates Einstein's Equivalence Principle (EEP).  In that scheme, the virtual proton/electron pairs cannot gravitate or they would have collapsed the universe, and yet they mediate momentum transfer.  This means they have to have different values for their gravitational and inertial masses, which violates EEP and all of GR.  QVF is therefore not true.

Woodward's work has done the opposite of deny what we know about life the universe and everything.  He has added to what we know by explaining how the surface of the electron can spin at 100c.  This is an amazing accomplishment since before Woodward's work, that seemed like a violation of GR, and as it turns out, it is required by GR.

As to your frustration in general, I feel your pain.  I would just point out however, that frustration does not justify failure to do due diligence.  As I explained earlier, the experimental setup does not lend itself to the kinds of simplification you're requiring.  You therefore need to invest the time to look at how the setup actually works, rather than stipulate it ought to work how you'd like.  The self-contained setup is NOT the best setup for the work Woodward has been doing to date.  Along these same lines I'd note to you, that you justify the work of others who did not provide vacuum, and appear to presume Woodward did not provide vacuum.  This is not true.  All of the spurious sources one can imagine have been dealt with one by one on Woodward's balance, including thermal, ion, Dean Drive effects, displacement effect, etc.  All of this is in the book.

http://www.amazon.com/Making-Starships-Stargates-Interstellar-Exploration/dp/1461456223

Quote
Time permitting I will try to find and read it. If I don't find it factual you owe me a bear.
If it isn't enjoyable I'll owe you a beer, or a scotch or whatever, but not a bear.  Bear's are expensive and ill-mannered.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/02/2014 04:03 pm
Quote from: JohnFornaro
It has been asserted and supported that the spurious signals associated with the experimental apparatus are a flaw in the experimental procedure which should be accommodated.
By whom has this been asserted?  Not by Dennis.  Please precise your statements so we can tell if they're true.  Who made this claim about which setup?

Quote
Attempts to calculate the magnitude of some kinds of the spurious forces depend upon dimensional data of the apparatus, data which has been deliberately kept under wraps.
You must be speaking of the Eagle work.  This is certainly not true of Woodward's work.  he put it in his book, publishes it every year and handed over the raw data to NASA.  He hasn't kept anything under wraps.  Who are you speaking of?

Quote
Analysis of the theory itself has suggested substantial flaws, with several attempts to propose more and more esoteric phenomena instead of the mass fluctuations which are the foundation of Woodward's theory.
This is just factually incorrect.  There's no truth to this statement at all, John.  Are you just making this stuff up?
 
Quote
In fact, some posters have suggested that the experiment will be sufficient proof of the anomalous thrusts, regardless of the correctness of the theory.
More weasel word's John.  What posters, where?  Who is making these charges?  Stop pretending to make complaints by pretending to represent others.  Either you have a specific complaint to make or you don't.  Do you or don't you?  This is most irresponsible language, John.
 
Quote
Many posters here have provided the caveat of how they don't have the time to understand and critique the theory, but go on to assert, without support, the soundness of the theory, or to propose yet another far fetched special effect of physics in support of the theory.
I think it's entirely likely there is not a single person in this forum with the skills to understand Woodward's theory.  This doesn't mean we're not entitled to make our best judgement of the evidence we can digest and stand by that judgement.  This is what taking responsibility is all about.  You on the other hand seem contented to make veiled insults and comments about comments with no support nor evidence.   Lets see the substance for these unfounded claims, John.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/02/2014 04:18 pm
Quote from: JohnFornaro
Notice how in this thread, "the book" is now being referred to as the ultimate, and probably the only source of "true" information on the theory.  It cannot be the case that the previous twenty years or so of theoretical work, some of it peer reviewed, is supplanted by this new book.
You're deliberately mischaracterizing and misrepresenting my word's, John.  I have repeatedly noted you can read Woodward's papers.  They're all available for free online.  The book constantly references the papers, but it is not usually the primary source--the peer reviewed papers are.  Still, the book gathers the work of 20 years into a single place, adds more detail than can be had in papers be they peer reviewed or conference, and is written for engineers rather than physicists.  Most of the people in this forum are not conversant in General Relativity, including you, John; so in general, you'll find the book a better source since it is written for people in your skill set.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 05:15 pm
I do not believe anyone is considering the book to be the only source of TRUE information.

Frustrated as I am about the debate, I end up not wording my comments at carefully as I should.  I did say "probably the only source of info".  But still, allow me to rephrase:

Quote from: JF
Notice how in this thread, "the book" is now being referred to as if it were the ultimate, and probably the only source of "true" information on the theory.  It cannot be the case that the previous twenty years or so of theoretical work, some of it peer reviewed, is supplanted by this new book.

You're deliberately mischaracterizing and misrepresenting my word's, John.

I'm not using your words, and please don't argue the past.  I corrected my sloppy grammar.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/02/2014 05:36 pm
Quote
Time permitting I will try to find and read it. If I don't find it factual you owe me a bear.
If it isn't enjoyable I'll owe you a beer, or a scotch or whatever, but not a bear.  Bear's are expensive and ill-mannered.

Yeah, well, right,  ;D
Thanks for the sensible clarifications and your effort to share your views.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/02/2014 05:54 pm
Well this forum is getting a bit out of hand here. Truth is, nobody knows how this darn thing works. At this point we don't even know if it works. The folks working at the coal face of this research have theories just as we do. I personally have posted on here a few very different ideas I had and from others, but none of that really matters because it is just speculation. I think we should be mindful to separate the "how" from the "why" until the effect has been scaled up and proven/dis proven. If this thing is shown experimentally to be real and is undeniable, then the rest of the scientific community will jump in and rewrite physics to explain it. I can tell you, as you already know that most theoretical physicist won't touch this until it is undeniable because it is a taboo subject and could damage their reputation. In addition to that, the very notion of the emdrive actually working puts their sacred cows like the precision of GR in jeopardy, not to mention supersymmetry and string theory. It is best to play nice with each other and don't toot our own horns too early and fall in love with our or others theories. Folks can submit research papers all day about x or y, but it doesn't amount to a hill of beans unless an experiment backs it up.
Title: Re: EM Drive Developments
Post by: raketa on 10/02/2014 06:02 pm
Quote
The experimental setup is not the trouble.  Since they cannot do a real evaluation of theory, what they've asked for is more thrust, which is what Jim is working on.

That makes no sensible sense to me. In this context this would be an application driven research ? So the trouble is the experimental setup. Why should they care about theories ? If the effect is hinting at being anything like it says it is, then pour the money and hire the third party experimentalists to do an all or nothing confirmation of any real effect at all. Even if all it takes is a mW thruster mounted on an atomic force microscope cantilever to get a few pN of thrust, just to see it's real. Then make phenomenological model. Then build better/bigger devices and see if it fits such or such ground breaking theory.
Even if the fact to pursue a higher thrust might contribute to show this is not a real effect and therefore allow for a progress, my point is that putting the focus on that is not the best way to assert the reality of any effect at all.
Again, the "this is impossible" hypothesis appears not well accommodated by the strategy.
I think we're talking past each other because you're not familiar with what I've been relating, which is Woodward's work.  I have little interest in the work at Eagle because I know the QVF hypothesis is wrong.  The Eagle work interests me in as much as it may be stumbling across M-E evidence, but this would be by mistake.  For example, it works only with a  dielectric and during switching transients which bear enough in common with an AC signal they can produce decent thrust.  But the DC signal doesn't do this.

Keep in mind the contrast here.  Woodward's scheme does not violate conservation.  There's nothing "new" in his work, nor any contradictions with conventional science.  In fact, while explaining his work, he very ably answered questions about the classical and semi-classical electron models we've had for decades, and as I said, he deserves a Nobel for this alone.  I'm not suggesting you skip ahead, but chapter 7 is a nail-biter.

In any event, I agree the "this is impossible" kinds of statements are unhelpful.  And the statement that QVF violates conservation is not really true.  That's a distraction fallacy intended to be later explained away as one becomes aware of what QVF is proposing.  However what is not a distraction is that QVF violates Einstein's Equivalence Principle (EEP).  In that scheme, the virtual proton/electron pairs cannot gravitate or they would have collapsed the universe, and yet they mediate momentum transfer.  This means they have to have different values for their gravitational and inertial masses, which violates EEP and all of GR.  QVF is therefore not true.

Woodward's work has done the opposite of deny what we know about life the universe and everything.  He has added to what we know by explaining how the surface of the electron can spin at 100c.  This is an amazing accomplishment since before Woodward's work, that seemed like a violation of GR, and as it turns out, it is required by GR.

As to your frustration in general, I feel your pain.  I would just point out however, that frustration does not justify failure to do due diligence.  As I explained earlier, the experimental setup does not lend itself to the kinds of simplification you're requiring.  You therefore need to invest the time to look at how the setup actually works, rather than stipulate it ought to work how you'd like.  The self-contained setup is NOT the best setup for the work Woodward has been doing to date.  Along these same lines I'd note to you, that you justify the work of others who did not provide vacuum, and appear to presume Woodward did not provide vacuum.  This is not true.  All of the spurious sources one can imagine have been dealt with one by one on Woodward's balance, including thermal, ion, Dean Drive effects, displacement effect, etc.  All of this is in the book.

http://www.amazon.com/Making-Starships-Stargates-Interstellar-Exploration/dp/1461456223

Quote
Time permitting I will try to find and read it. If I don't find it factual you owe me a bear.
If it isn't enjoyable I'll owe you a beer, or a scotch or whatever, but not a bear.  Bear's are expensive and ill-mannered.
Interesting. I will definitely read book.
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 06:09 pm
Sciama lived until December 19, 1999. 

If anyone knows of a paper that Sciama wrote commenting on transient fluctuations in the local proper energy density as being a possible means for propellant-less propulsion, or a local violation of momentum-conservation, please let us know, as it would be of much interest.

This is a link to one of the last Sciama's papers published, in 1994: "On the Interaction Between Cosmic Rays and Dark Matter Molecular Clouds in the Milky Way. l Basic Considerations"

http://cds.cern.ch/record/389845/files/9906159.pdf?version=1

and this is a paper on "Astrophysical evidence for the existence of black holes" he submitted in 1999:

http://arxiv.org/abs/astro-ph/9912186
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/02/2014 06:44 pm
I don't think Sciama ever did that.  I think that is Woodward's claim to fame.  First place the notion was published was probably "Measurement of a Machian Transient Mass Fluctuation," Foundations of Physics Letters 4, 407- 423 (1991).
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 07:09 pm
I think we should be mindful to separate the "how" from the "why" until the effect has been scaled up and proven/dis proven.

With this sentence, I suddenly realized the validity of separating experiment from theory.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/02/2014 07:09 pm
Yes, the basic issue is whether rest mass can change at the particle level and not just as a rearrangement of kinetic energy.
Woodward has never suggested we can alter the rest mass of particles, but rather only of bulk mass items that store Mach Effects or mass fluctuations in the interatomic energy bonds.  In fact, all bulk matter stores delta mass during deformation, since deformation changes the energy in these bonds and energy = mass X c^2.
Title: Re: EM Drive Developments
Post by: wembley on 10/02/2014 07:21 pm
...
But I don't think he uses that approach any more:
"The first thruster built by SPR Ltd and tested in 2003 also used a dielectric section, but to obtain our subsequent high thrust levels, we abandoned the dielectric and concentrated on our present cavity design."
Where is the above quotation from? (I would appreciate a link for it so that I can further understand the context)

Thanks for your response

_________
PS: I looked for it , but I could not find that statement in this 2006 report:   http://www.newscientist.com/data/images/ns/av/shawyertheory.pdf

This was in an email from Dr Shawyer in response to the NASA paper. Have you tried contacting him?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/02/2014 07:27 pm
Quote from: JF
...these few pages are not a complete derivation of the operating principles

When there are equations, I prefer to just go with equations -that's my personal viewpoint. If I am missing some new equation, I would appreciate it being pointed out. Thank you.

My math whiz friend asked me to supply a derivation regarding these equations.  I could not do this, and scanned those pages, because I thought that the derivation resided in that passage.  so I just threw it out to the community here.

I realize that I asked for a lot up thread, when I requested an equational line of reasoning which started with, say, e=Mc^2 and resulted in propellantless drive or an explanation of inertia.`
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 07:42 pm
...
But I don't think he uses that approach any more:
"The first thruster built by SPR Ltd and tested in 2003 also used a dielectric section, but to obtain our subsequent high thrust levels, we abandoned the dielectric and concentrated on our present cavity design."
Where is the above quotation from? (I would appreciate a link for it so that I can further understand the context)

Thanks for your response

_________
PS: I looked for it , but I could not find that statement in this 2006 report:   http://www.newscientist.com/data/images/ns/av/shawyertheory.pdf

This was in an email from Dr Shawyer in response to the NASA paper. Have you tried contacting him?

Thank you for your response.  I understand that Shawyer knows that you (if I recall correctly, please forgive me and correct me if I'm wrong) are a writer with contributions to AviationWeek and Wired, as he disclosed the above information to you.

I am not in the media, and thus I treat communications with me as private, and I only discuss in forums information that is generally available to the public.  Thus, from this viewpoint you are in a better position than me to gather and release such information  :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 07:44 pm
I found this intriguing, interesting pre-publication paper by Sciama, which he wrote in 1954, about a year after his paper on the origins of inertia that is used by Woodward for his transient formulation.

"On a possible method of shielding gravitation"
http://gravityresearchfoundation.org/pdf/awarded/1954/sciama.pdf

Since this typewritten paper with handwritten notes is pre-publication, I checked its legitimacy:

<<Dennis Sciama who wrote on a possible method of shielding gravitation using Mach’s principle.>> page 9 of "The Role of Gravitation in Physics, Report from the 1957 Chapel Hill Conference"  http://www.edition-open-access.de/media/sources/5/Sources5.pdf

This paper by Sciama is very interesting because:

Sciama concludes that the universe must contain an assembly of masses with negative energy

Sciama considers the covariant inertial-gravitational field metric and the covariant matter field.  Sciama examines the equations from the viewpoint of a rotating frame.  Sciama concludes that there must be extra negative terms in the covariant matter field, and that these terms are due to particles carrying the gravitational field, possessing negative energy.  He also concludes that they should have gravitational repulsion and could be used as a gravity shield.

Sciama does not use the transient fluctuation as justification for this negative energy particles, actually their origin and existence is not at all related to the "wormhole" square term in Woodward's formulation.  I find that noteworthy, that Sciama travels this completely different road (than Woodward) towards negative energy.
Title: Re: EM Drive Developments
Post by: raketa on 10/02/2014 07:47 pm
Start to read Woodward book and it is fascinating. It remembers me The Feynman Lectures on Physics. Instead of usual approach trying confuse crowd, because they  don't understand and try cover up it, James try to explain what we know how we know.
Love example of Galileo about law of movement, how everybody could see how far ball  is go  base on smoothness of surface, but nobody want to change it and have idea to see that will move indefinitely if not friction, which was obvious if  you are able to look without prediction.
Interesting discussion about inertia, looks like we are back at the beginning of 20 century and going adjust  STR , like Einstein had adjust Newton physic  Fascinating. EM Drive is just byproduct of rethinking of understanding of our universe. Einstein through his theory practically close our universe for travelling to stars and Woodward maybe open it again as possible scenario. It is so excited to live in this time, in all frontier we are moving forward like didn't happen for last 40 years. In decade maybe Mars(because Spacex), in 20-30 years interstellar probe if EM drive will work.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/02/2014 08:03 pm
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?letter=.&classic=YES&bibcode=1953MNRAS.113...34S&page=&type=SCREEN_VIEW&data_type=PDF_LOW&send=GET&filetype=.pdf

Sciama's 1953 paper above.

I gotta say IMHO of course, I am completely anti Machian and derivatives such as Sciama's take on inertia. Let me explain:

Mach's ideas come from a time where he didn't enjoy the benefit of anything QM. He didn't even believe that atoms exist I read somewhere.

Sciama mentions in his introduction accelerations in reference to the fixed stars. His ideas didn't enjoy the benefit of knowing the universe is expanding and accelerating.

For the life of me, I cringe when I read things such as local matter interacting with the distant matter of the universe, that kind of stuff. This isn't relevant anymore. How can we get instantaneous thrust if the action depends on a gravinertial field propagating at C.

What makes more sense to me are the various theories which explain the origin of inertia as quantum phenomena. Quantum effects are local, here, and now.

http://calphysics.org/index.html

http://arxiv.org/find/physics/1/au:+McCulloch_M/0/1/0/all/0/1 
(similar to above but further modifies inertia when in an environment with very low accelerations)

This emdrive thing has taken up a lot of my time lately, not so much as if or why it works. I have discovered that the jury is out on so many fundamental scientific concepts which I thought were nailed down, like inertia, origin or mass (not simply/only Higgs) and dark matter/energy. The dark energy/matter thing really bugs me. They were clearly invented to explain away inadequacies in theory attempting to explain observation. Instead of revising theory, more "crap" was piled on to fix it. Kinda like the games renormalization plays; card tricks. I think the current state of science is in bad shape in that theory has trumped observation. I get that it is important to spend time/money looking for new particles/gravity waves, etc. But I see little effort from mainstream science to go back and question itself when nothing new is found. One can ride a bunk theory for years and build a career of it. Then we end up with unfalsifiable theories like string theory or more particles like superpartners. Gravinertial fields are yet another invention to address something happening here and now that isn't explained by current accepted theory. Thus I am excited when I read things like "Anomalous Thrust Production from an RF Test Device" because if it really is true, it will really shake up the old tired paradigm I briefly ranted about above. It would do science a service if we would "play with what we got", instead of creating new theories to play with. GR hasn't let us down yet, but it is macro. There is a gap between macro and micro which could be filled in by modifying GR on its boundaries where appropriate, instead of treating it as complete. Einstein doesn't have an ego anymore. I admire Hawking for continually adjusting to the times.







 
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 08:04 pm
Also, Sciama, in his paper

"On a possible method of shielding gravitation"
http://gravityresearchfoundation.org/pdf/awarded/1954/sciama.pdf

accepts the fact that the boundary conditions for the equations of General Relativity are not specified and this is a subject of controversy, particularly regarding conclusions as in Sciama's Mach theory.

I have previously addressed the issue of boundary conditions in a comment from @Mulletron regarding the Unruh effect.

This issue (of boundary conditions in General Relativity) is very important for Sciama's theory, particularly for the approximation used by Sciama, for his inertial effect (the terms in a perturbation of GR are not decreasing rapidly such that one can neglect the far field).  In fact the far-field is critical for Sciama's inertial theory, and definitely for Woodward fluctuation theory (dealing with 2nd order derivatives).
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/02/2014 08:06 pm
He also concludes that they should have gravitational repulsion and could be used as a gravity shield.
This is a common mistake even physicists make very often.  Although negative mass has negative gravitational action and is thus repelled by other matter, it also has negative inertial action so the direction of the former is reversed by the latter.  So negative mass actually acts like normal mass, despite it's backward inertia.
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 08:14 pm
He also concludes that they should have gravitational repulsion and could be used as a gravity shield.
This is a common mistake even physicists make very often.  Although negative mass has negative gravitational action and is thus repelled by other matter, it also has negative inertial action so the direction of the former is reversed by the latter.  So negative mass actually acts like normal mass, despite it's backward inertia.
This is from a paper written by Sciama one year after he wrote the 1953 paper that Woodward uses as the foundation for his transient equations based on Machian inertia. Please reconsider your statement that Sciama made a mistake in 1954 in not properly considering  Machian "inertial action"
Sciama's negative energy particles in this paper are not due to or related to what Woodward considers negative energy due to the quadratic of the transient term.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/02/2014 08:24 pm
How can we get instantaneous thrust if the action depends on a gravinertial field propagating at C.
This is an excellent question and holds for EM fields as well as gravitational.  Wheeler and Feyman's answer is found in their absorber theory:

http://en.wikipedia.org/wiki/Wheeler–Feynman_absorber_theory

Since Maxwell's equations have two solutions, both forward in time (retarded wave) and backward in time (advanced wave), they chose to use them both to explain instantaneity or the "action at a distance" problem.  Woodward merely applied this same theory to gravitation as is explained in his book.  I'd note if you don't like this explanation so far as inertia and gravity are concerned, then you should apply this same objection to all field theory, without which we would for instance have no electric motors.

Note too, the very nice dovetail this makes with John Cramer's Transactional Interpretation of QM.  You'll find that in the book as well.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/02/2014 08:30 pm
He also concludes that they should have gravitational repulsion and could be used as a gravity shield.
This is a common mistake even physicists make very often.  Although negative mass has negative gravitational action and is thus repelled by other matter, it also has negative inertial action so the direction of the former is reversed by the latter.  So negative mass actually acts like normal mass, despite it's backward inertia.
This is a paper from a paper written by Sciama one year after he wrote the 1953 paper that Woodward uses as the foundation for his transient equations based on Machian inertia. Please reconsider your statement that Sciama made a mistake in 1954 in not properly considering  Machian "inertial action"
Sciama's negative energy particles in this paper are not due to or related to what Woodward considers negative energy due to the quadratic of the transient term.
Yes.  That's completely correct.  Sciama is of course right that negative gravitational action comes from negative gravitational mass, but IIRC, he failed to note the negative inertial action reverses this otherwise backward action, and I have seen many physicists do this same thing.  I myself presumed if negative mass were a natural state of matter, that it would be scarce since it would be repelled by normal mass, but Woodward corrected me that although it would want to fall away from all matter, it would fall toward it because of the reversed inertial sign.  As it turns out, we're surrounded by negative matter but didn't realize it until Woodward's discovery.
Title: Re: EM Drive Developments
Post by: 93143 on 10/02/2014 08:36 pm
Sciama mentions in his introduction accelerations in reference to the fixed stars. His ideas didn't enjoy the benefit of knowing the universe is expanding and accelerating.

He knew it was expanding.  Isn't that what a "Robertson-Walker" metric means?  Y'know, more or less...

Quote
This isn't relevant anymore.

http://arxiv.org/pdf/1208.3096v2.pdf

negative inertial action reverses this otherwise backward action

Isn't that only true for the negative mass?  Positive mass would still be repelled by it.
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 08:44 pm
negative inertial action reverses this otherwise backward action

Isn't that only true for the negative mass?  Positive mass would still be repelled by it.

And therefore would act as a gravity shield against our planet's (positive mass) attraction, which was the whole point of Sciama's 1954 paper.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/02/2014 09:26 pm
Sciama mentions in his introduction accelerations in reference to the fixed stars. His ideas didn't enjoy the benefit of knowing the universe is expanding and accelerating.

He knew it was expanding.  Isn't that what a "Robertson-Walker" metric means?  Y'know, more or less...

Quote
This isn't relevant anymore.

http://arxiv.org/pdf/1208.3096v2.pdf


Thanks for sending the link. I gotta say though, in the conclusion, it basically says that Mach's principle wasn't viable until dark matter and energy came on scene.

Edit: Additional thought. If dark energy/matter haven't been detected, this paper essentially poo poos Mach's principle. Does this sound like a logical flow?
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 09:45 pm
Sciama mentions in his introduction accelerations in reference to the fixed stars. His ideas didn't enjoy the benefit of knowing the universe is expanding and accelerating.

He knew it was expanding.  Isn't that what a "Robertson-Walker" metric means?  Y'know, more or less...

Quote
This isn't relevant anymore.

http://arxiv.org/pdf/1208.3096v2.pdf


Thanks for sending the link. I gotta say though, in the conclusion, it basically says that Mach's principle wasn't viable until dark matter and energy came on scene.

Edit: Additional thought. If dark energy/matter haven't been detected, this paper essentially poo poos Mach's principle. Does this sound like a logical flow?

To another point, the author has a more recent paper: "Gravitational Lagrangians, Mach’s Principle, and the Equivalence Principle in an Expanding Universe" http://downloads.hindawi.com/journals/jgrav/2014/415649.pdf

where he concludes, again (as previously concluded by other authors), by other arguments, that the density must equal the density that makes (3D) space flat.  He needs to "renormalize" the bare mass by a factor of 11/2 . Mmmmmmm
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/02/2014 09:47 pm
I haven't read that paper but for the history of Mach's Principle, you'll likely be better off here:

http://www.amazon.com/Machs-Principle-Newtons-Quantum-Einstein/dp/0817638237

Einstein did not in the formal sense "incorporate" Mach's Principle, but he named it that and it is doubtful he could have invented GR without it.  Certainly GR is consistent with it.  The best source for the history of the thing is one of the editors in this book, Julian Barbour; though Woodward give a good bit of the history as well.
Title: Re: EM Drive Developments
Post by: 93143 on 10/02/2014 10:06 pm
If dark energy/matter haven't been detected, this paper essentially poo poos Mach's principle.

If I understand correctly, the key point is that the density parameter needs to be of order unity (various approximations seem to deviate from exact unity by different factors).  And according to WMAP (and more recently Planck), the density parameter is basically one.  Why this is so, precisely, would seem to be a separate question.

Dark matter and dark energy have been detected, in a sense.  That's all they are, really; labels for detected behaviours, with no accepted theory attached.  Dark matter = something is gravitating, and we can't see it.  Dark energy = the universe is accelerating, therefore something must be causing it to do so.  It does not seem unreasonable to me to expect whatever is causing these effects to also participate in (or otherwise modify the nature or magnitude of) a Machian gravinertial interaction.

If a major theoretical overhaul occurs, similar to what happened with Copernicus or Einstein, we can reevaluate, but given what we know now, it seems Sciama's idea is plausible.

It does seem a point in its favour that it was formulated before unconnected, uninterested scientists made the observations that established it as physically tenable...  Maybe it's just a misleading coincidence - but in that case, don't we have to explain why the predicted inertia-like gravelectric forces aren't in evidence, or else show that they disappear when the Einstein field equations are used without approximation?  These forces seem to result directly from calculations using conventional gravity theory, without any proprietary special sauce added to get them to appear...
Title: Re: EM Drive Developments
Post by: Rodal on 10/02/2014 10:12 pm
negative inertial action reverses this otherwise backward action

Isn't that only true for the negative mass?  Positive mass would still be repelled by it.

And therefore would act as a gravity shield against our planet's (positive mass) attraction, which was the whole point of Sciama's 1954 paper.

Hermann Bondi using General Relativity concluded

( http://journals.aps.org/rmp/abstract/10.1103/RevModPhys.29.423 )

A) on one hand positive mass attracts all masses, including a positive mass attracting a negative mass.

B) on the other hand Bondi also concluded that a negative mass repels all masses, so it repels a positive mass.

Bondi concluded that as the negative mass tries to get closer to the positive mass, because of A), while the positive mass is repelled from the negative mass because of B), what really happens is that the negative mass chases the positive mass across the universe at an ever accelerating speed.

Therefore, he agrees with Sciama in that negative mass would be extremely difficult to find.
Title: Re: EM Drive Developments
Post by: aceshigh on 10/02/2014 11:05 pm
Woodward has never suggested we can alter the rest mass of particles, but rather only of bulk mass items that store Mach Effects or mass fluctuations in the interatomic energy bonds.  In fact, all bulk matter stores delta mass during deformation, since deformation changes the energy in these bonds and energy = mass X c^2.


Interesting, did not know that. Thanks.
Title: Re: EM Drive Developments
Post by: aero on 10/02/2014 11:43 pm
I was wondering how much energy was stored within the cavity (truncated frustum) so have been (off and on) looking at math for which I have absolutely no background beyond undergraduate course work. Using the input power and Q-factors given, I calculate that the RF wave B field and E field has energy like:

B field range from 0.27 to 0.62 tesla, and
E field range from 80.4 to 184.8 Mv per metre.

Are these reasonable values?

I also calculated that the energy mass of the RF wave ranges from 0.00064 to 0.0034 micrograms.

At this point I don't know what to do with these numbers but maybe someone will find them interesting.

We know from the "Anomalous Thrust ..." report that the COMSOL finite element calculations display a maximum Electric field of 47189 Volts per meter (p. 10, Fig. 14).  I couldn't find any numerical information given for the Electric Field results from COMSOL for the Tapered Cavity.

Also, you may find something useful for comparison in FIg. 16 of the report, for the predicted and actual gain (S21), as attached here (vertical scale: Amplitude (dB); horizontal scale: frequency):

(The numbering convention for S-parameters is that the first number following the “S” is the port where the signal emerges, and the second number is the port where the signal is applied. S21 is a measure of the signal coming out port 2 relative to the RF stimulus entering port 1: the ratio of transmitted to incident voltage signals.  S21 is the forward complex transmission coefficient)

It is apparent that the comparison from this COMSOL analysis to the actual results is not that great...

I could very easily be making an error in my calculations - BUT - Fig. 14 is for the Cannae Cavities while my calculations address the tapered frustum. The paper doesn't give a Q-factor for the Cannae Cavities so I can't do a calculation to check myself with that example. On the other hand, I can do a calculation to estimate what the Q-factor would be if the stored RF wave energy results in an electric field of 4.7189E+04 volts per meter. It is very, very small. Small to the point of being nonsense at ~0.0007.

Correct me where I'm wrong, but the E field energy of the RF wave is given from w = epsilon_sub_o* E^2 where w is energy per unit volume, epsilon_sub_o = 8.85418782 × 10-12 m-3 kg-1 s4 A2 and the Quality factor is energy stored / energy lost per cycle. So I'm taking w = 28 watts with the unit volume of one and calculating much larger values than Fig. 14 shows.
Thank you for pointing out that the Q factor for the Cannae drive is not given. I had forgotten that.
This is my understanding:

Cannae drive: E field data is provided.  No Q factor provided.
Tapered Cavity: E field numerical data range not provided.  Q factor provided.

________________

These are my calculations for the Maximum power  density in ("Teflon") PTFE dielectric resonator for Cannae device (notice the frequency  "f" in the calculation):

MaximumPower = 2 Pi f (E^2) (permittivity of free space) (epsilon')

Taking the

maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m , and the given

frequency of 935 MHz, it follows (for the Teflon PTFE dielectric resonator) that:


MaximumPower per unit volume [W/m^3] = 2 Pi (935*10^6 1/s) (( 4.7189*10^4)^2) (8.85418782*10^(-12)) (2.1)

MaximumPower per unit volume (in the dielectric resonator)~  243 W/cm^3

If you divide your

<<E field range from 80.4 to 184.8 Mv per metre>>

by the square root of the angular frequency for the Cannae drive:

 Sqrt[ 2 Pi (935*10^6 1/s) ] = 76647.1

one gets:

E field range from 1049 to 2411 Volts per meter.

which is not too far from the COMSOL calculations (there is also an uncertainty due to the Volume)


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
While for the tapered cavity

If you divide your

<<E field range from 80.4 to 184.8 Mv per metre>> by the actual square root of the angular frequency

 Sqrt[ 2 Pi (1932.6*10^6 1/s) ] = 110195

one gets

E field range from 730 to 1677 Volts per meter (there is also an uncertainty due to the Volume)

Pardon me for quoting a volume of information but I think we can now discuss the real point of all this. That is, Rodal can since he has the math, I think.

As we know, the energy needed to create electron/positron pairs is 2*0.511 MeV which equals 1.6374 wattseconds. We now have some idea of the energy contained within the cavity and it is way more than enough to create e/p pairs. But is that energy properly oriented and concentrated enough for pair production? I found that the pair generally moves in the direction of the photon that created it (Wikipedia) but I don't know that any single photon contains sufficient energy, or how to calculate individual photon energy within the cavity.

Of course if pairs can be produced then we need to look very hard at Dr. White's theory for the thrust production.

I did look at the intensity of the RF wave in the dielectric of the Cannae device from the COMSOL figure.

Intensity=Power-watts/area (m^2), so area = power/average intensity = 28 Watts/RF power.
I calculate the area = 9.474 square millimeter, so the power is quite concentrated.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 12:16 am
Woodward has never suggested we can alter the rest mass of particles, but rather only of bulk mass items that store Mach Effects or mass fluctuations in the interatomic energy bonds.  In fact, all bulk matter stores delta mass during deformation, since deformation changes the energy in these bonds and energy = mass X c^2.


Interesting, did not know that. Thanks.
Thus, Sciama's theory which was intended by Sciama only as an explanation of inertial mass, becomes in this interpretation of Woodward's theory a constitutive theory of matter, as words like "Woodward has never suggested we can alter the rest mass of particles, but rather only of bulk mass items that store Mach Effects or mass fluctuations in the interatomic energy bonds.  In fact, all bulk matter stores delta mass during
deformation, since deformation changes the energy in these bonds and energy = mass X c^2."

Constitutive laws cannot be determined theoretically. Theory (using for example frame-indifference, thermodynamics, symmetries, etc.) can only restrict, narrow down, the type of constitutive relation for a bulk material, but theory cannot prescribe what kind of constitutive equation a real material should have.

For example, there are countless definitions of rates of stress (Jaumann, Truesdell, Piola, Kirchoff, etc., and convected definitions) that satisfy frame-indifference.   A Physicist cannot prescribe what definition of stress rate  and strain-rate will lead to a linear constitutive relation for a given material in nature.

<< all bulk matter stores delta mass during deformation>> is an (strain-energy) Elastic constitutive prescription.  Yet we know that the plain classical solid matter surrounding us is not necessarily elastic, including viscoelasticity (linear and nonlinear), as well as plasticity (softening and hardening with strain), etc. etc. and variations thereof (viscoelastic-plastic, viscoelastic-viscoplastic, etc.).  A Physicist cannot select what the correct "constitutive" equation should be. 

That can only be determined by experiment.  There are plenty of constitutive theories that were found not to be followed by most materials.  As a simple example, while a negative Poisson's ratio, as negative as -1, is allowed for an isotropic material by the theory of elasticity and by thermodynamic considerations, it is known that isotropic materials (not man-made) found in nature have a positive Poisson's ratio.

EDIT: Let's call the point at which constitutive statements are attached to Woodward's theory, a "W theory," such that "W theory" stands for the whole theory including any attached constitutive statement.

So even if one were to accept Woodward's theory on a theoretical basis, at the point that Woodward's theory becomes a constitutive theory, it does not follow that actual materials would have to behave as prescribed by "W theory" with a Buldrini factor >0.  I think that Buldrini understood this and that's why he allowed his "fudge factors" to range all the way from zero (for a value of zero there is no Woodward effect).

Only experiments would be able to show whether they do or do not.  However, if one were to accept  "W theory"  on a theoretical basis, and materials in nature are found not to obey it, the interesting possibility could still be raised whether such a  "W theory" material could be eventually be man-made (to allow propellant-less drives) as for example now we are able to make isotropic materials with very negative Poisson's ratio that don't exist in nature.  (The experiments that are trying to verify Woodward's effect now are limiting themselves to materials that are presently available for other uses, not materials that have been engineered by man first at the nano level and eventually at the molecular level with the only intent to maximize such a "W theory" effect. )
Title: Re: EM Drive Developments
Post by: raketa on 10/03/2014 12:30 am
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?letter=.&classic=YES&bibcode=1953MNRAS.113...34S&page=&type=SCREEN_VIEW&data_type=PDF_LOW&send=GET&filetype=.pdf

Sciama's 1953 paper above.

I gotta say IMHO of course, I am completely anti Machian and derivatives such as Sciama's take on inertia. Let me explain:

Mach's ideas come from a time where he didn't enjoy the benefit of anything QM. He didn't even believe that atoms exist I read somewhere.

Sciama mentions in his introduction accelerations in reference to the fixed stars. His ideas didn't enjoy the benefit of knowing the universe is expanding and accelerating.

For the life of me, I cringe when I read things such as local matter interacting with the distant matter of the universe, that kind of stuff. This isn't relevant anymore. How can we get instantaneous thrust if the action depends on a gravinertial field propagating at C.

What makes more sense to me are the various theories which explain the origin of inertia as quantum phenomena. Quantum effects are local, here, and now.

http://calphysics.org/index.html

http://arxiv.org/find/physics/1/au:+McCulloch_M/0/1/0/all/0/1 
(similar to above but further modifies inertia when in an environment with very low accelerations)

This emdrive thing has taken up a lot of my time lately, not so much as if or why it works. I have discovered that the jury is out on so many fundamental scientific concepts which I thought were nailed down, like inertia, origin or mass (not simply/only Higgs) and dark matter/energy. The dark energy/matter thing really bugs me. They were clearly invented to explain away inadequacies in theory attempting to explain observation. Instead of revising theory, more "crap" was piled on to fix it. Kinda like the games renormalization plays; card tricks. I think the current state of science is in bad shape in that theory has trumped observation. I get that it is important to spend time/money looking for new particles/gravity waves, etc. But I see little effort from mainstream science to go back and question itself when nothing new is found. One can ride a bunk theory for years and build a career of it. Then we end up with unfalsifiable theories like string theory or more particles like superpartners. Gravinertial fields are yet another invention to address something happening here and now that isn't explained by current accepted theory. Thus I am excited when I read things like "Anomalous Thrust Production from an RF Test Device" because if it really is true, it will really shake up the old tired paradigm I briefly ranted about above. It would do science a service if we would "play with what we got", instead of creating new theories to play with. GR hasn't let us down yet, but it is macro. There is a gap between macro and micro which could be filled in by modifying GR on its boundaries where appropriate, instead of treating it as complete. Einstein doesn't have an ego anymore. I admire Hawking for continually adjusting to the times.
I agree with aversion toward dark matter. I think you will enjoy Woodward book. I finish just 15%, but it is like course of the history SRT and GRT and in the same try to move forward and solve the problem inertia.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 12:42 am


Pardon me for quoting a volume of information but I think we can now discuss the real point of all this. That is, Rodal can since he has the math, I think.

As we know, the energy needed to create electron/positron pairs is 2*0.511 MeV which equals 1.6374 wattseconds. We now have some idea of the energy contained within the cavity and it is way more than enough to create e/p pairs. But is that energy properly oriented and concentrated enough for pair production? I found that the pair generally moves in the direction of the photon that created it (Wikipedia) but I don't know that any single photon contains sufficient energy, or how to calculate individual photon energy within the cavity.

Of course if pairs can be produced then we need to look very hard at Dr. White's theory for the thrust production.

I did look at the intensity of the RF wave in the dielectric of the Cannae device from the COMSOL figure.

Intensity=Power-watts/area (m^2), so area = power/average intensity = 28 Watts/RF power.
I calculate the area = 9.474 square millimeter, so the power is quite concentrated.
I think we calculated this a way back, with @notsureofit and @frobnicat and we all concluded that the 2 photon interaction in the microwave is way off from being able to make the virtual electron/positron pair real.  I think that it takes a petawatt laser with picosecond period to be able to make the virtual electron/positron pair real.  The frequency of the microwave is too low. That's why we eliminated the virtual electron/positron pair.

Dark matter axions remain a real possibility.  I think @frobnicat is warning us that it is still off by 6 orders of magnitude (if I recall correctly).  If @frobnicat is correct that would still be much closer than the ability of the microwave to make virtual electron/positron pairs real.  And I have not seen @frobnicat's calculations yet.
My concern with the dark matter axionic explanation is the density of axionic matter in our neighborhood: it appears to be too low according to that last paper we reviewed to justify the measured thrusts.  But there are excellent people at Harvard that I recall expect a significantly larger density.

In all this I look forward to @notsureofit's and @frobnicat comments.
Title: Re: EM Drive Developments
Post by: 93143 on 10/03/2014 12:47 am
However, if one were to accept Woodward's theory on a theoretical basis, and materials in nature are found not to obey it

I think you're conflating two things: Woodward's theory (which describes what happens when certain things occur in a material) and the properties of the material (which describe how easily and/or efficiently those things can be forced to occur in it).

Woodward's theory itself has no efficiency terms.  Those terms result from an attempt to map experimentally imposed parameters onto the quantities appearing in his equations.  Since the electromechanical response of the material is what performs this mapping in real life, the efficiency terms represent the constitutive relations, which are not the Mach effect but mediate between the Mach effect and the attempt to force it to happen.

...

Assuming Woodward's theory is accepted for the sake of argument, saying a real-life material doesn't obey it is like saying a real-life material doesn't obey the law of gravity.  A feather may not fall as fast as a brick, but there are other reasons for that.

Or perhaps a better example is a collision.  Most real-life collisions don't appear to obey conservation of energy, until you account for dissipation of that energy in forms other than the bulk kinetic energy of the colliding objects.

Combining these two examples, bouncing a ball off the pavement and having it not quite come back up to the height it was dropped from does not mean the ball fails to obey either the law of gravity or the law of conservation of energy.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 01:12 am
However, if one were to accept Woodward's theory on a theoretical basis, and materials in nature are found not to obey it

I think you're conflating two things: Woodward's theory (which describes what happens when certain things occur in a material) and the properties of the material (which describe how easily and/or efficiently those things can be forced to occur in it).

Woodward's theory itself has no efficiency terms.  Those terms result from an attempt to map experimentally imposed parameters onto the quantities appearing in his equations.  Since the electromechanical response of the material is what performs this mapping in real life, the efficiency terms represent the constitutive relations, which are not the Mach effect but mediate between the Mach effect and the attempt to force it to happen.

Assuming Woodward's theory is accepted for the sake of argument, saying a real-life material doesn't obey it is like saying a real-life material doesn't obey the law of gravity.  A feather may not fall as fast as a brick, but there are other reasons for that.

I was explicitly addressing the comment <<"Woodward has never suggested we can alter the rest mass of particles, but rather only of bulk mass items that store Mach Effects or mass fluctuations in the interatomic energy bonds.  In fact, all bulk matter stores delta mass during  deformation, since deformation changes the energy in these bonds and energy = mass X c^2.">> which does not appear in your quote above.

The statement <<all bulk matter stores delta mass during  deformation>> is certainly a constitutive statement.

The statement <<bulk mass items that store Mach Effects or mass fluctuations in the interatomic energy bonds>> for which the above was used as an analogy is another constitutive statement, specifically when invoking "interatomic bonds".

And concerning Buldrini, you yourself agree that << the [Buldrini] efficiency terms represent the constitutive relations>>.   

I conflated the name "Woodward" for all of these things under the same "Woodward" umbrella: the Buldrini factors, the Stahl quotation, and the the fluctuation terms following from Sciama's derivation.  Putting what Stahl writes under the same umbrella as Woodward, or Buldrini's theory under Woodward's umbrella maybe unfair but writing would otherwise become very awkward.  I will write "W theory" from now on to encompass Woodward's formulation plus any (macroscopic or microscopic) constitutive statements that are attached to it.
Title: Re: EM Drive Developments
Post by: 93143 on 10/03/2014 01:15 am
I thought I explained what I was talking about pretty well...
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 01:21 am
http://calphysics.org/index.html

Thanks very much for that link.

Quote from: Bernard Haisch
"Advances are made by answering questions. Discoveries are made by questioning answers."

There went the evening.

And as an aside, adding to an earlier post of mine.  My UVA math whiz read several of the Sciama papers at my suggestion, before asking me about the derivation.  The disappointing remark that he made was, "I don't have the time to really dig into this."
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 02:08 am
I thought I explained what I was talking about pretty well...

Well, you edited what you wrote since I answered it.  Concerning << Most real-life collisions don't appear to obey conservation of energy, until you account for dissipation of that energy in forms other than the bulk kinetic energy of the colliding objects.

Combining these two examples, bouncing a ball off the pavement and having it not quite come back up to the height it was dropped from does not mean the ball fails to obey either the law of gravity or the law of conservation of energy>>

Agreed that they do not fail to obey the law of gravity or conservation of energy.  What they fail to obey is the (Cauchy-Hooke) law of perfect elasticity.  What is normally called the impact "coefficient of restitution" is a constitutive law, it is usually due to plastic, viscoelastic or viscoplastic energy  dissipation, which are all due to constitutive relations in which the body is not perfectly elastic.  I have edited my previous original post that motivated your comment to now read "W theory" for Woodward's theory plus any constitutive statement (macroscopic or microscopic in nature) attached to it.


Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 02:54 am
I thought I explained what I was talking about pretty well...

Well, you edited what you wrote since I answered it.  Concerning << Most real-life collisions don't appear to obey conservation of energy, until you account for dissipation of that energy in forms other than the bulk kinetic energy of the colliding objects.

Combining these two examples, bouncing a ball off the pavement and having it not quite come back up to the height it was dropped from does not mean the ball fails to obey either the law of gravity or the law of conservation of energy>>

Agreed that they do not fail to obey the law of gravity or conservation of energy.  What they fail to obey is the (Cauchy-Hooke) law of perfect elasticity.  What is normally called the impact "coefficient of restitution" is a constitutive law, it is usually due to plastic, viscoelastic or viscoplastic energy  dissipation, which are all due to constitutive relations in which the body is not perfectly elastic.  I have edited my previous original post that motivated your comment to now read "W theory" for Woodward's theory plus any constitutive statement (macroscopic or microscopic in nature) attached to it.

Actually, your example is excellent to further discuss this.  If you model the ball simplistically as a lumped mass, you can solve the problem with a "coefficient of restitution", but that is a "back of the envelope" solution, and not an engineering solution for the continuous body.  If a company making tennis balls (or golf balls) wanted to improve the design of the balls they would conduct a more comprehensive solution: the solution of a number of differential equations, including the equilibrium equations, the strain-displacement equations and the (stress-strain) constitutive equations.  The tennis ball (or the golf ball) exhibits large deformations during impact hence it is necessary to be careful to choose the stress and strain measures.  Frame-indifference would restrict the choices.  Energy conjugation (between stress, stress-rate, strain and strain-rate) would further restrict the choices.  But there are still multiple choices that can be made.  It turns out that to best characterize the constitutive behavior of the ball's material certain choices of stress, stress-rate, strain and strain-rate lead to simpler constitutive laws exhibited by materials in nature.  Although the equilibrium equations and strain-displacement equations are not constitutive equations, the best choice for the stress and strain measures in the constitutive equations dictates what stress measure will appear in the equilibrium equation (it is in the equilibrium equation where gravity appears).  Similarly for the strain-displacement equation.  They are all affected by what measures are used. And the equilibrium equation is affected by the type of stress measure used, because different stress rate measures involve different quantities (spins or deformation gradients).

A similar issue appears as to what is known as the Abraham-Minkowski controversy: the Abraham-Minkowski controversy can only be resolved by experiments with real materials, it cannot be resolved theoretically. And if one adds "hidden momentum" terms as done by Shockley, one can use either Abraham's or Minkowski's formulation, but one of them is always more elegant (involving less terms) depending on what actual matter is being modeled.

Similarly, if one were to analyze a real material, not as a lumped mass, but as a continuum mechanics problem using a finite element analysis for example as proposed by Stahl, these issues appear concerning the complete "W theory": Woodward's theory plus constitutive statements. Particularly for real materials which in nature are anisotropic.  Because, in a material one has to consider the stress tensor, not just forces.
Title: Re: EM Drive Developments
Post by: Vultur on 10/03/2014 06:54 am
not to mention supersymmetry and string theory.

I thought string theory was dead now since the Higgs Boson mass was wrong. Or am I totally off base (just something I heard in a talk)?
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/03/2014 07:22 am
After catching up on the past few pages, I'd be lying if I said I really understood any of what you're discussing. I don't suppose anyone has some good ideas on testable predictions from these theories?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 07:29 am
What does the UVA acronym stand for?

Wahoo-wah.

Quote
...this disappointed you for what reason? because he didn't have the time?

Well, yeah.  You expect me to learn all this stuff?  I'm as lazy as the next internet wag.  That's what we have post-doc grads for.  I thought you knew that!

Good thing I'm not losing sleep over this.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 07:33 am
Yes, the basic issue is whether rest mass can change at the particle level and not just as a rearrangement of kinetic energy.

I thought the lattice was composed of chemical bonds, which, when they heat up, among other things, vibrate more, sometimes to the breaking point.  And if all these bonds are vibrating, and the various nucleii aren't moving, then I'm having a hard time with the "bulk acceleration" belief system.

If rest mass can change at all by microwave manipulation in these low energy ranges, it can change at the particle level, I would think.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 07:46 am
The derivation of the field equation containing A) the second derivative with respect to time of Eo ("the local proper energy density") and B) the square of the first derivative with respect to time of Eo ("the local proper energy density"),

* is not in these pages attached by John. John could you also attach those pages? Thanks

Scanned a bit too fast the other day, and missed this.

Rephrase that for me a mite, mate?

Ise confused.  You want the derivates of A) and B)?  I've tapped out my UVA whiz, but I will take a stab at it, if ya give me a few hints.

Is the starting equation the "field equation" from Sciama '53?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 08:04 am
After catching up on the past few pages, I'd be lying if I said I really understood any of what you're discussing. I don't suppose anyone has some good ideas on testable predictions from these theories?

I realize that I asked for a lot up thread, when I requested an equational line of reasoning which started with, say, e=Mc^2 and resulted in propellantless drive or an explanation of inertia.`

If I may?

If what is commonly known as a scientist is well grounded in the liberal arts, the English language, (here in America, people.  The rest of the world can just enjoy the squabble) rhetoric, logic, fairness, and a genuine effort to understand by using the Socratic method, that scientist will realize that I also ask for "testable predictions".

There is more than one way to ask questions.
Title: Re: EM Drive Developments
Post by: raketa on 10/03/2014 08:12 am
However, if one were to accept Woodward's theory on a theoretical basis, and materials in nature are found not to obey it

I think you're conflating two things: Woodward's theory (which describes what happens when certain things occur in a material) and the properties of the material (which describe how easily and/or efficiently those things can be forced to occur in it).

Woodward's theory itself has no efficiency terms.  Those terms result from an attempt to map experimentally imposed parameters onto the quantities appearing in his equations.  Since the electromechanical response of the material is what performs this mapping in real life, the efficiency terms represent the constitutive relations, which are not the Mach effect but mediate between the Mach effect and the attempt to force it to happen.

...

Assuming Woodward's theory is accepted for the sake of argument, saying a real-life material doesn't obey it is like saying a real-life material doesn't obey the law of gravity.  A feather may not fall as fast as a brick, but there are other reasons for that.

Or perhaps a better example is a collision.  Most real-life collisions don't appear to obey conservation of energy, until you account for dissipation of that energy in forms other than the bulk kinetic energy of the colliding objects.

Combining these two examples, bouncing a ball off the pavement and having it not quite come back up to the height it was dropped from does not mean the ball fails to obey either the law of gravity or the law of conservation of energy.
Your example is not good what Woodward try to claim. He is not questioning  mass that you can measure during low speeds. His theory try to explain mass increase during speed close to light speed and possibility manipulate increase mass/inertia at these moments. I am really recommending to read book, I finish first 15% and it is very interesting. All these claims that he invented device and try to explain how is it works are completely wrong. Looks like he spend lot time to to build his theory and now try to prove it through testing. It is very rare example. If he didn't believe his theory are right, I think he will not wasting time with testing, in his life situation.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 08:43 am
not to mention supersymmetry and string theory.

I thought string theory was dead now since the Higgs Boson mass was wrong. Or am I totally off base (just something I heard in a talk)?

I believe string theory is very much alive. The problem is that testing it is a pain. The Higgs mechanism is correct. It is an electroweak interaction, which helps confer rest mass to matter. This is one component to mass. The Higgs mechanism imparts the rest mass to matter. There are other types of mass. Basically whenever a particle interacts with a field in such a way that symmetry is broken, it gains a mass energy component from that field, be it electroweak, color, gravity, stochastic quantum fluctuations. If symmetry is preserved, no energy is given, no mass is gained. Mass has a lot of parts. Mass can be intrinsic or extrinsic, depending on whether the field contributing energy is inside the particle (color) or around the particle.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 12:44 pm
[Woodward] is not questioning  mass that you can measure during low speeds. His theory try to explain mass increase during speed close to light speed and possibility manipulate increase mass/inertia at these moments.

That's my understanding as well.

I believe that he admits to not being able to accelerate an ion to these speeds, and is now attempting to accelerate the lattice at these speeds.

Again, unless I'm confused, this paper (http://ntrs.nasa.gov/search.jsp?R=20140006052) claims that "Approximately 30-50 micro-Newtons of thrust were recorded from an electric propulsion test article consisting primarily of a radio frequency (RF) resonant cavity excited at approximately 935 megahertz". 

They offer this tentative explanation for how the device works:  "Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma".

This is a different operating principle than the one thought to be operative by Woddward.

Again, unless I'm confused, bewildered, and a host of other terms, including un-read, the thread topic has included these two theories of operation on a propellantless drive.

Nobody has yet explained how either of these devices actually work, other than the obvious; that the devices covert electrical energy to forward momentum, which is the only thing that the term "electric propulsion" can mean.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 12:49 pm
Equation experiment:

□=gνμ∇ν∇μ=1−g−−−√∂μ(−g−−−√∂μ).

Edit: Humph. What's the secret to posting equations beyond the Fortran method that I know how to use, but which seems limited to algegraic equations?

\begin{align*}
\Box &= \sum_a \partial^a\partial_a \,, &
\hat\Box &= \sum_a \mathcal{D}^a\mathcal{D}_a
\end{align*}

2nd Edit:  Humph again.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 12:57 pm
Wanted to share info about casimir energies in cavities and vacuum expectation values in various systems. Spent all morning researching boundary conditions wrt shapes other than parallel plates. This says cones have positive casimir energy (repulsive). By repulsive do they mean net effect on the cavity walls? Or space? QV? A poynting vector?

http://merlin.fic.uni.lodz.pl/concepts/2005_3_4/2005_3_4_137.pdf

Other neat stuff I waded through:

http://www.calphysics.org/articles/Davis_STAIF06.pdf

http://books.google.it/books?id=CqE1f_s5PgYC&pg=PA33&redir_esc=y#v=onepage&q&f=false

http://arxiv.org/pdf/1306.4370v1.pdf

http://arxiv.org/pdf/quant-ph/0106045.pdf

www.technologyreview.com/view/416697/how-to-build-casimir-molecules/

http://arxiv.org/pdf/1101.5409v2.pdf

http://www.pnas.org/content/108/17/6867.full

http://scholar.lib.vt.edu/theses/available/etd-04272004-200428/unrestricted/casimir-effect.pdf


Edit:

I wanted to throw it out there that as I understand it, the casimir effect between the plates equates to a small negative mass energy by virtue of all other modes being excluded. This is the difference of potential, similar to volts. The sign of casimir energy doesn't denote positive/negative mass energy; just the direction of bias. The energy is negative with respect to the universe. Not necessarily a mass less than zero. A lower mass. Think of it as a direction toward the vacuum, not reaching it, and not crossing below it. Another way to think of it is possible hole flow in electronics. Am I right?
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 01:10 pm
Wanted to share info about casimir energies in cavities and vacuum expectation values in various systems. Spent all morning researching boundary conditions wrt shapes other than parallel plates. This says cones have positive casimir energy (repulsive). By repulsive do they mean net effect on the cavity walls?
We discussed this with @frobnicat, @aero and others way back in this thread.  Nobel Prize Winner Schwinger was so dissatisfied with Casimir's explanation for the Casimir force (that relies on the quantum vacuum) that Schwinger came up with his own derivation that explains the Casimir force strictly as a van der Waal force, in terms of charges.  (Great physicists like Pauli, Feynman and DeWitt were also dissatisfied with Casimir's explanation) Casimir was successful in predicting the Casimir force for flat plates but unsuccessful for other geometries.  What made it worse is that Casimir's derivation can even get the sign wrong.  Schwinger's derivation (although more complicated) gets the sign correctly for different geometries.  One problem is that the fine structure constant plays an important role in deriving the Casimir force for different geometries.  Casimir's explanation for flat plates does not contain the fine structure constant. 

The Casimir force is attractive for flat plates but it is repulsive for cones.  Repulsive means that the cones are pushed apart by the Casimir force.  Flat plates are attracted to each other by the Casimir force.  But the plates have to be extremely close (nanometers or less) for the Casimir force to be significant.

I don't see any relation between the Casimir force and the microwave cavity, as the distance between the microwave cavity walls is so large that the Casimir force between them is completely negligible.  If I misunderstood something please forgive me (I haven't had a coffee this morning yet).
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 01:18 pm
I don't expect to get much use out of the casimir force either. I'm more interested in the asymmetry created by the exclusion of all other modes by the effect and the shape of the device.
Title: Re: EM Drive Developments
Post by: aceshigh on 10/03/2014 01:27 pm
Nobody has yet explained how either of these devices actually work, other than the obvious; that the devices covert electrical energy to forward momentum, which is the only thing that the term "electric propulsion" can mean.

in simple terms, Woodwards device works by using these mass fluctuations... pull when it´s light, push when it´s heavier. That is how I understand it.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 01:30 pm

I wanted to throw it out there that as I understand it, the casimir effect between the plates equates to a small negative mass energy by virtue of all other modes being excluded. This is the difference of potential, similar to volts. The sign of casimir energy doesn't denote positive/negative energy. It is negative with respect to the universe nomatter the sign. Another way to think of it is possible hole flow in electronics. Am I right?

Well, count me with Jaffe at MIT:   http://cua.mit.edu/8.422/Reading%20Material/Jaffe2005_Casimir.pdf

<<In discussions of the cosmological constant, the Casimir effect is often invoked as decisive evidence
that the zero-point energies of quantum fields are ‘‘real.’’ On the contrary, Casimir effects can be
formulated and Casimir forces can be computed without reference to zero-point energies.
They are
relativistic, quantum forces between charges and currents. The Casimir force (per unit area) between
parallel plates vanishes as , the fine structure constant, goes to zero>>

I do not think that the Casimir force is related to negative mass.  The "all other modes being excluded" explanation is Casimir's.  It works for flat plates but it doesn't work for several other geometries. 
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 01:30 pm
Please continue to scan the pages ... until you reach Woodward's main result: the wave equation for the gravitational potential (the  d'Alembertian of phi) on the left hand side of the equation, and on the right hand side of the equation: the term (4 Pi G rho) and the terms containing the derivatives with respect to time.

Yes, O my master.

The power of the virtual martini mind meld is amazingly strong in this one.

Claiming fair use for educational principles again, here are pages 70-75.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 01:44 pm
Nobody has yet explained how either of these devices actually work, other than the obvious; that the devices convert electrical energy to forward momentum, which is the only thing that the term "electric propulsion" can mean.

in simple terms, Woodwards device works by using these mass fluctuations... pull when it´s light, push when it´s heavier. That is how I understand it.

Could you point me to a link where that simple explanation has already been made?

Oh wait.

The device aims to convert electricity to forward motion. ...

There are two problems which have not yet been addressed or answered.  "Push heavy, pull light", which is the summary of the M-E device's operation, relies upon action at a distance with the inertia of the entire Hubble sphere surrounding the device.

7b. AIUI, it is conjectured that the interstitial atomic bonds in the capacitor move at relativistic speeds, over small distances, with properly timed alternating, opposed electrical signals.  Because it is supposed that there is a time lag between the extemes of motion in this cycle, that the electrical signals can be timed so as to "push heavy" in one dirrection, and "pull light" in the other.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 01:45 pm
Why is there a dollar sign after MachEffect as in "MachEffect$" at the top left of every page?

R U Sirius?

That's the Greek symbol for Martini.

Sheesh.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 01:47 pm
Also, the first page that came up for me a few minutes ago:

http://fr.wikipedia.org/wiki/%C3%89quation_de_d%27Alembert

The good news?  I understand this as well as I understand the English page!
Title: Re: EM Drive Developments
Post by: JasonAW3 on 10/03/2014 01:53 pm
Ok, likely an oversimplification on my part, but;

If a solar sail can work via reflected photons, could not another drive, using a pure electron stream, (which has mass) also work?

Pointing a basic idea out here, mass is being expended as a propellent whether that mass be of a chemical, nuclear, ionic or even an electron stream. You have to have SOMETHING to generate the power. be it a generator or solar panels.  In the case of Solar panels, the electrons are being generated via the energy produced via capturing and converting photons into electrical power.  (Not very effecient, granted, but mass is being exchanged, even is on an almost quantum level).

Like I said, likely a vast oversimplification, but according to basic physics, it should work.

In the case as presented, it sort of appears that the electron stream, may be being concentrated and accelerated to increse their effective mass.

Assuming that you could either focus, or effectively "Laser" focus the electron stream, there should be some sort of thrust in the opposing direction, even if it were in the millinewtons of force. Basic Newtonian Physics, "Every Action has an equal and opposite reaction."
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 02:17 pm
Kemosabe.  Buy the damn book!

In all fairness, this is the last time I can provide and claim this fair use educational scanning service today. 

Quote from: Rodal
Please continue to scan the pages ... until you reach Woodward's main result: the wave equation for the gravitational potential (the  d'Alembertian of phi) on the left hand side of the equation, and on the right hand side of the equation: the term (4 Pi G rho) and the terms containing the derivatives with respect to time.

These are all of the equations which precede page 70.  There are equations on pages 40 and 66.  In between p-35 and p-70 are three addenda, reasonably presumed to support Woodward's derivation, here summarized:

#1 Sciama 1953, p37
#2 Brans, 1962, p388-396
#3 Nordtverdt, 1988, 91395-1404

Would you be so kind as to repost the PDF's for Brans and Nordtverdt?  I don't have them yet.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 02:20 pm
In the case as presented, it sort of appears that the electron stream, may be being concentrated and accelerated to increse their effective mass.

They are not claiming that mass, regardless of its elemental particle composition, including electrons, is coming out of the device.

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/03/2014 02:26 pm
EDIT: Let's call the point at which constitutive statements are attached to Woodward's theory, a "W theory," such that "W theory" stands for the whole theory including any attached constitutive statement.

So even if one were to accept Woodward's theory on a theoretical basis, at the point that Woodward's theory becomes a constitutive theory, it does not follow that actual materials would have to behave as prescribed by "W theory" with a Buldrini factor >0.  I think that Buldrini understood this and that's why he allowed his "fudge factors" to range all the way from zero (for a value of zero there is no Woodward effect).

Only experiments would be able to show whether they do or do not.  However, if one were to accept  "W theory"  on a theoretical basis, and materials in nature are found not to obey it, the interesting possibility could still be raised whether such a  "W theory" material could be eventually be man-made (to allow propellant-less drives) as for example now we are able to make isotropic materials with very negative Poisson's ratio that don't exist in nature.  (The experiments that are trying to verify Woodward's effect now are limiting themselves to materials that are presently available for other uses, not materials that have been engineered by man first at the nano level and eventually at the molecular level with the only intent to maximize such a "W theory" effect. )
I think what you're saying is true, but it is not Woodward's theory that all bulk matter stores delta mass when deformed.  That's undergrad physical chemistry.  Woodward chose shape change materials since they have very large changes in internal energy--the largest I know of.  So I don't think it's fair to say this is a constituative part of his theory.  His theory only stipulates that if one changes the internal energy of a mass while accelerating it, you will get this 2w fluctuation, or Mach Effect.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 02:40 pm
...
These are all of the equations which precede page 70.  There are equations on pages 40 and 66.  In between p-35 and p-70 are three addenda, reasonably presumed to support Woodward's derivation, here summarized:

#1 Sciama 1953, p37
#2 Brans, 1962, p388-396
#3 Nordtverdt, 1988, 91395-1404

Would you be so kind as to repost the PDF's for Brans and Nordtverdt?  I don't have them yet.
The purpose of your scanning educational exercise was to show in this thread the actual Derivation equations as they appear in The Book, to better guide discussion.

Can you point out to any equation in The Formal Derivation in The Book that were not present in his previously published papers?

Yes, I know that there new and different words, and supporting material.  I'm talking strictly about the mathematical equations in The Formal Derivation leading to the final transient fluctuation equation .

You are asking for something I cannot offer.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 02:44 pm
EDIT: Let's call the point at which constitutive statements are attached to Woodward's theory, a "W theory," such that "W theory" stands for the whole theory including any attached constitutive statement.

So even if one were to accept Woodward's theory on a theoretical basis, at the point that Woodward's theory becomes a constitutive theory, it does not follow that actual materials would have to behave as prescribed by "W theory" with a Buldrini factor >0.  I think that Buldrini understood this and that's why he allowed his "fudge factors" to range all the way from zero (for a value of zero there is no Woodward effect).

Only experiments would be able to show whether they do or do not.  However, if one were to accept  "W theory"  on a theoretical basis, and materials in nature are found not to obey it, the interesting possibility could still be raised whether such a  "W theory" material could be eventually be man-made (to allow propellant-less drives) as for example now we are able to make isotropic materials with very negative Poisson's ratio that don't exist in nature.  (The experiments that are trying to verify Woodward's effect now are limiting themselves to materials that are presently available for other uses, not materials that have been engineered by man first at the nano level and eventually at the molecular level with the only intent to maximize such a "W theory" effect. )
I think what you're saying is true, but it is not Woodward's theory that all bulk matter stores delta mass when deformed.  That's undergrad physical chemistry.  Woodward chose shape change materials since they have very large changes in internal energy--the largest I know of.  So I don't think it's fair to say this is a constituative part of his theory.  His theory only stipulates that if one changes the internal energy of a mass while accelerating it, you will get this 2w fluctuation, or Mach Effect.
So much semantic discussion about attaching a name to a theory!

All theories are "built on the shoulders of giants".  No recent (during the past few hundreds years) theory attached to a name has been built solely by the person whose name is attached to it.  Einstein's General Relativity uses non-Euclidean geometry and the tools of Levi-Civita, Riemann, and many others.  This line of complaining would be like somebody saying that Einstein's theory involves a particular kind of non-Euclidean geometry, and you saying, no that was part of previous knowledge.

If the total theory to solve a problem contains a constitutive assumption, that's part of the total theory to analyze a problem, even if that part came from existing knowledge.  Concerning the Mach effect, the theory uses Sciama's 1953 derivation as a foundation, so one may even call it Woodward/Sciama/Mach.

Again, since there is so much concern in this thread about what a given total theory should be called, I will strive from now on to use the term "W theory".

__________
EDIT: I much prefer this thread when it contains the tools of engineers and scientists:  numbers, equations, spreadsheets, graphs, images and links.  Instead of words, discussions about history, or discussions about name attribution. 

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/03/2014 02:48 pm
[Woodward] is not questioning  mass that you can measure during low speeds. His theory try to explain mass increase during speed close to light speed and possibility manipulate increase mass/inertia at these moments.

That's my understanding as well.

I believe that he admits to not being able to accelerate an ion to these speeds, and is now attempting to accelerate the lattice at these speeds.

Again, unless I'm confused, this paper (http://ntrs.nasa.gov/search.jsp?R=20140006052) claims that "Approximately 30-50 micro-Newtons of thrust were recorded from an electric propulsion test article consisting primarily of a radio frequency (RF) resonant cavity excited at approximately 935 megahertz". 

They offer this tentative explanation for how the device works:  "Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma".

This is a different operating principle than the one thought to be operative by Woddward.

Again, unless I'm confused, bewildered, and a host of other terms, including un-read, the thread topic has included these two theories of operation on a propellantless drive.

Nobody has yet explained how either of these devices actually work, other than the obvious; that the devices covert electrical energy to forward momentum, which is the only thing that the term "electric propulsion" can mean.
John, I don't want to have a conflict with you here.  I do feel though I ought to point out that even your questions are wrong.  Fact is, what Woodward proposes does work at low velocities.  It's not a relativistic mechanism at all.  And your posts about chemical bonds and accelerating the lattice, all based on terrible misunderstandings.  You are correct that Woodward's theory has nothing to do with Shawyer's model, or White's QVF model.  These are just alternative models for explaining this propellantless thrust.  However, you don't seem to be able to identify which comments refer to which model or theory.

This is why I suggest you read the book, because there is no value added by posting time and again from ignorance.  You're just posting to be posting.  Almost everything you're writing is wrong.  Even your high school chemistry is wrong.  So why are you posting?  Read the book.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/03/2014 02:53 pm
Nobody has yet explained how either of these devices actually work, other than the obvious; that the devices covert electrical energy to forward momentum, which is the only thing that the term "electric propulsion" can mean.

in simple terms, Woodwards device works by using these mass fluctuations... pull when it´s light, push when it´s heavier. That is how I understand it.
This is correct.  I would note too, that it is not really accurate to say the device converts electrical into mechanical energy, as a transducer.  Rather, it controls the flow of the gravinertial flux into and out of the active mass, and this can be used to produce mechanical force.  So really the device is a gravinertial transistor.   It is not converting one energy form into another but rather, controlling the flow of what gives matter its mass and inertia.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 03:39 pm
Ok, likely an oversimplification on my part, but;

If a solar sail can work via reflected photons, could not another drive, using a pure electron stream, (which has mass) also work?

Pointing a basic idea out here, mass is being expended as a propellent whether that mass be of a chemical, nuclear, ionic or even an electron stream. You have to have SOMETHING to generate the power. be it a generator or solar panels.  In the case of Solar panels, the electrons are being generated via the energy produced via capturing and converting photons into electrical power.  (Not very effecient, granted, but mass is being exchanged, even is on an almost quantum level).

Like I said, likely a vast oversimplification, but according to basic physics, it should work.

In the case as presented, it sort of appears that the electron stream, may be being concentrated and accelerated to increse their effective mass.

Assuming that you could either focus, or effectively "Laser" focus the electron stream, there should be some sort of thrust in the opposing direction, even if it were in the millinewtons of force. Basic Newtonian Physics, "Every Action has an equal and opposite reaction."

Yeah it does work but it is several orders of magnitude less of an effect than the already very small effect from the emdrive test campaign. I remember seeing this before.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/03/2014 03:41 pm
All theories are "built on the shoulders of giants".  No recent (during the past few hundreds years) theory attached to a name has been built solely by the person whose name is attached to it.  Einstein's General Relativity uses non-Euclidean geometry and the tools of Levi-Civita, Riemann, and many others.  This line of complaining would be like somebody saying that Einstein's theory involves a particular kind of non-Euclidean geometry, and you saying, no that was part of previous knowledge.

If the total theory to solve a problem contains a constitutive assumption, that's part of the total theory to analyze a problem, even if that part came from existing knowledge.  Concerning the Mach effect, the theory uses Sciama's 1953 derivation as a foundation, so one may even call it Woodward/Sciama/Mach.

Again, since there is so much concern in this thread about what a given total theory should be called, I will strive from now on to use the term "W theory".
Woodward has always gone to great lengths to point out his work comes directly from Sciama.  I think he sees himself as following Sciama's lead and he points out others as well.  This is why you need to read the book.  If you're like me, you get plenty enough time sitting in front of the screen here, and a bit of paper in one's hand, a soft couch and something to snack on is a welcome break.  And Woodward really is an excellent writer.  It's a pleasure to read him, unlike so many others in the field.

IMHO, Woodward's work is best referred to as "M-E theory" or "Mach Effect physics" since at its core, it is this ability to generate what Woodward has termed "Mach Effects" that is key.  He has always chafed at attempts to connect his name with his theory, as one finds on wikipedia.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/03/2014 03:41 pm
No recent ... theory attached to a name has been built solely by the person whose name is attached to it.

Obviously, you are not familiar with my theory, now generally accepted, that everybody's an idiot except for me.
Title: Re: EM Drive Developments
Post by: D_Dom on 10/03/2014 05:08 pm
when did you get promoted to general?

Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 05:12 pm

I wanted to throw it out there that as I understand it, the casimir effect between the plates equates to a small negative mass energy by virtue of all other modes being excluded. This is the difference of potential, similar to volts. The sign of casimir energy doesn't denote positive/negative energy. It is negative with respect to the universe nomatter the sign. Another way to think of it is possible hole flow in electronics. Am I right?

Well, count me with Jaffe at MIT:   http://cua.mit.edu/8.422/Reading%20Material/Jaffe2005_Casimir.pdf

<<In discussions of the cosmological constant, the Casimir effect is often invoked as decisive evidence
that the zero-point energies of quantum fields are ‘‘real.’’ On the contrary, Casimir effects can be
formulated and Casimir forces can be computed without reference to zero-point energies.
They are
relativistic, quantum forces between charges and currents. The Casimir force (per unit area) between
parallel plates vanishes as , the fine structure constant, goes to zero>>

I do not think that the Casimir force is related to negative mass.  The "all other modes being excluded" explanation is Casimir's.  It works for flat plates but it doesn't work for several other geometries.

Yeah I'm hearing you and I'm enjoying the discussion but I have to add that if the fine structure constant were to approach 0, electromagnetism itself would collapse. The fine structure constant is dependent of the permeability and permittivity of free space and C. C depends on vacuum permittivity and vacuum permeability. Thus free space has its own impedance. The QED vacuum is diamagnetic. This:

http://www.mpl.mpg.de/en/institute/news/news/article/a-link-between-particle-physics-and-maxwells-equations.html

Whether speaking classically or quantumly, they are EXACTLY the same thing described in different ways. QM just adds probability and locality to the mix. And yes, quoting the paper "Casimir effects can be
formulated and Casimir forces can be computed without reference to zero-point energies. They are
relativistic, quantum forces between charges and currents," is exactly right. The vacuum fields/particles are exactly the same as the "real" ones, they interact the same, no difference whatsoever. The only difference is their probability and ubiquity because of that. The are near the ground state of the universe and consequently have a very low probability of being detected except by some of the modes like the ones near the compton wavelength of electrons which slightly influence their energy levels. Other effects too. A fleeting particle with a low probability is the same as saying a nano degree of a wave. The fine structure constant would never be 0 and the paper shows a dependence between Casimir and the fine structure constant. The fine structure constant is quantum anyway, so basically they are further marrying classical and quantum. Who is to say the casimir effect can't be the result of BOTH classical and quantum boundary conditions. It seems unwise to limit it in such a way described.

I want to clarify that negative mass doesn't necessarily mean <0 mass, which would be <0 energy, which would be <absolute zero temperature. Just negative with respect to the established vacuum energy of the universe.

Edit:
Observation: Since free space is a diamagnetic dielectric, would a frequency dependent complex permittivity arise? I can't find any evidence it does. The spectral distribution of the CMB which peaks around 160ghz sure looks like that of plot.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/03/2014 05:32 pm
The vacuum fields/particles are exactly the same as the "real" ones, they interact the same, no difference whatsoever.
I'm sorry, but this is not true.  Virtual particles do not gravitate.  If the proposed virtual particles did gravitate, their mass added to our universe would have prevented its expansion from the start, and would currently cause it to collapse.  This is why most physicists don't buy the ZPF and QVF conjectures, because they're based upon zero mass virtual particles but then expect those particles to transfer momentum, which is a violation of EEP as stated above.

Virtual particles are just an accounting mechanism.  There' no reason to suppose they exist at all and Casimir effect can be explained without them.  Indeed it has been for decades.

However, if you want the primary text for ZPF physics written by true believers, you want this:

http://www.amazon.com/Frontiers-Propulsion-Progress-Astronautics-Aeronautics/dp/1563479567/ref=sr_1_1?ie=UTF8&qid=1412356998&sr=8-1&keywords=AIAA+Davis+Millis





Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 05:35 pm

I wanted to throw it out there that as I understand it, the casimir effect between the plates equates to a small negative mass energy by virtue of all other modes being excluded. This is the difference of potential, similar to volts. The sign of casimir energy doesn't denote positive/negative energy. It is negative with respect to the universe nomatter the sign. Another way to think of it is possible hole flow in electronics. Am I right?

Well, count me with Jaffe at MIT:   http://cua.mit.edu/8.422/Reading%20Material/Jaffe2005_Casimir.pdf

<<In discussions of the cosmological constant, the Casimir effect is often invoked as decisive evidence
that the zero-point energies of quantum fields are ‘‘real.’’ On the contrary, Casimir effects can be
formulated and Casimir forces can be computed without reference to zero-point energies.
They are
relativistic, quantum forces between charges and currents. The Casimir force (per unit area) between
parallel plates vanishes as , the fine structure constant, goes to zero>>

I do not think that the Casimir force is related to negative mass.  The "all other modes being excluded" explanation is Casimir's.  It works for flat plates but it doesn't work for several other geometries.

Yeah I'm hearing you and I'm enjoying the discussion but I have to add that if the fine structure constant were to approach 0, electromagnetism itself would collapse. The fine structure constant is dependent of the permeability and permittivity of free space and C. C depends on vacuum permittivity and vacuum permeability. Thus free space has its own impedance. The QED vacuum is diamagnetic. This:

http://www.mpl.mpg.de/en/institute/news/news/article/a-link-between-particle-physics-and-maxwells-equations.html

Whether speaking classically or quantumly, they are EXACTLY the same thing described in different ways. QM just adds probability and locality to the mix. And yes, quoting the paper "Casimir effects can be
formulated and Casimir forces can be computed without reference to zero-point energies. They are
relativistic, quantum forces between charges and currents," is exactly right. The vacuum fields/particles are exactly the same as the "real" ones, they interact the same, no difference whatsoever. The only difference is their probability and ubiquity because of that. The are near the ground state of the universe and consequently have a very low probability of being detected except by some of the modes like the ones near the compton wavelength of electrons which slightly influence their energy levels. Other effects too. A fleeting particle with a low probability is the same as saying a nano degree of a wave. The fine structure constant would never be 0 and the paper shows a dependence between Casimir and the fine structure constant. The fine structure constant is quantum anyway, so basically they are further marrying classical and quantum. Who is to say the casimir effect can't be the result of BOTH classical and quantum boundary conditions. It seems unwise to limit it in such a way described.

I want to clarify that negative mass doesn't necessarily mean <0 mass, which would be <0 energy, which would be <absolute zero temperature. Just negative with respect to the established vacuum energy of the universe.

Bondi's arguments (see http://forum.nasaspaceflight.com/index.php?topic=29276.msg1265704#msg1265704 ) persuade me that it is extremely unlikely for us to find (or contain if artificially produced) negative mass for the reasons given by Bondi (negative mass would quickly escape off into the universe). 

I have the view that the Casimir force is mostly an engineering annoyance in constructing nanodevices but not something that will be useful for space propulsion.

But as Keynes said, my opinions are subject to change as new data becomes available  :)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 05:44 pm
The vacuum fields/particles are exactly the same as the "real" ones, they interact the same, no difference whatsoever.
I'm sorry, but this is not true.  Virtual particles do not gravitate.  If the proposed virtual particles did gravitate, their mass added to our universe would have prevented its expansion from the start, and would currently cause it to collapse.  This is why most physicists don't buy the ZPF and QVF conjectures, because they're based upon zero mass virtual particles but then expect those particles to transfer momentum, which is a violation of EEP as stated above.

Virtual particles are just an accounting mechanism.  There' no reason to suppose they exist at all and Casimir effect can be explained without them.  Indeed it has been for decades.

However, if you want the primary text for ZPF physics written by true believers, you want this:

http://www.amazon.com/Frontiers-Propulsion-Progress-Astronautics-Aeronautics/dp/1563479567/ref=sr_1_1?ie=UTF8&qid=1412356998&sr=8-1&keywords=AIAA+Davis+Millis


Yes you are right about gravitation and thanks. I forgot that. It is a good thing they don't gravitate or space time would be curved instead of flat. When you look at a universe full of quickly appearing and annihilating particle pairs/also viewed as waves out of phase across all phases, the net effect is 0 energy/0 mass for any given instant. But if you take a weighted average of all this happening, you arise a a very small mass energy contribution, not 10^120 too much warping space time. It is like white noise with values above and below 0db but the QV, specifically the electromagnetic QV, deals in charge and energy.

Edit more thoughts.

Curious why it is repulsive vice attractive. Could it be a consequence of the shape of the universe? More casimir effects? Given the observed dipole moment of the CMB, maybe? I read other reasons too.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/03/2014 06:00 pm
Bondi's arguments (see http://forum.nasaspaceflight.com/index.php?topic=29276.msg1265704#msg1265704 ) persuade me that it is extremely unlikely for us to find (or contain if artificially produced) negative mass for the reasons given by Bondi (negative mass would quickly escape off into the universe).
So far as I understand it, this is an error that was corrected by Robert Forward.  To state again, any permanently negative mass would experience a reverse gravity force away from all normal mass bodies, but it would respond backward to that force because of its reverse inertia.

This is surprisingly complex, but the best analysis came not from Herman Bondi but Robert Forward.  You'll find a good treatment of it here, and note the link to Forward's "Diametric Drive":

http://en.wikipedia.org/wiki/Negative_mass

"Although no particles are known to have negative mass, physicists (primarily Hermann Bondi and Robert L. Forward) have been able to describe some of the anticipated properties such particles may have. Assuming that all three concepts of mass are equivalent the gravitational interactions between masses of arbitrary sign can be explored.

For two positive masses, nothing changes and there is a pull on each other causing an attraction. Two negative masses would produce a pull on one another, but would repel because of their negative inertial masses. For different signs there is a push that repels the positive mass but attracts the negative mass.

Bondi pointed out that two objects of equal and opposite mass would produce a constant acceleration of the system towards the positive-mass object.[citation needed] However, the total mass, momentum and energy of the system would remain 0.

This behavior is completely inconsistent with a common-sense approach and the expected behaviour of 'normal' matter; but is completely mathematically consistent and introduces no violation of conservation of momentum or energy. If the masses are equal in magnitude but opposite in sign, then the momentum of the system remains zero if they both travel together and accelerate together, no matter what their speed:


And equivalently for the kinetic energy :


Forward extended Bondi's analysis to additional cases, and showed that even if the two masses m(-) and m(+) are not the same, the conservation laws remain unbroken. This is true even when relativistic effects are considered, so long as inertial mass, not rest mass, is equal to gravitational mass.

This behaviour can produce bizarre results: for instance, a gas containing a mixture of positive and negative matter particles will have the positive matter portion increase in temperature without bound. However, the negative matter portion gains negative temperature at the same rate, again balancing out. Geoffrey A. Landis pointed out other implications of Forward's analysis,[2] including noting that although negative mass particles would repel each other gravitationally, the electrostatic force would be attractive for like-charges and repulsive for opposite charges.

Forward used the properties of negative-mass matter to create the diametric drive, a design for spacecraft propulsion using negative mass that requires no energy input and no reaction mass to achieve arbitrarily high acceleration.

Forward also coined a term, "nullification" to describe what happens when ordinary matter and negative matter meet: they are expected to be able to "cancel-out" or "nullify" each other's existence. An interaction between equal quantities of positive and negative mass matter would release no energy, but because the only configuration of such particles that has zero momentum (both particles moving with the same velocity in the same direction) does not produce a collision, all such interactions would leave a surplus of momentum, which is classically forbidden."

Also note that although Woodward is saying electrons have this negative mass, they are "dressed" such that they have positive mass.  To understand what dressing and undressing is and the history behind the need to dress elementary particles, read Woodward chapter 7.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 06:14 pm

This is surprisingly complex, but the best analysis came not from Herman Bondi but Robert Forward.  You'll find a good treatment of it here, and note the link to Forward's "Diametric Drive":

http://en.wikipedia.org/wiki/Negative_mass

Bondi's analysis is correct. 
Title: Re: EM Drive Developments
Post by: birchoff on 10/03/2014 06:32 pm

This is surprisingly complex, but the best analysis came not from Herman Bondi but Robert Forward.  You'll find a good treatment of it here, and note the link to Forward's "Diametric Drive":

http://en.wikipedia.org/wiki/Negative_mass

Bondi's analysis is actually the correct one. 

Anybody can write stuff in Wikipedia. 

As an example, I wrote a whole article, including the mathematical analyses plots here  :)   :  http://en.wikipedia.org/wiki/Beta_distribution

really after that lengthy counter argument we get this short response???

A side from the questionable reference, what makes Forwards analysis incorrect but Bondi's correct?
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 06:42 pm
really after that lengthy counter argument we get this short response???
I edited as follows "Bondi's analysis is correct."

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/03/2014 06:53 pm
Well if we get someone to generate enough negative mass for a diametric drive, your opinion here will matter.  ;)  But I did explain to you the error most people make.  They forget that the mass responds backward to the force on it.  Negative mass gravitates away from or experiences a gravitational force away from normal mass, but moves toward it because of its negative inertia.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 07:03 pm
Would like to be able to use equations rather than words.  :)

HELP: Is it possible to write equations in this forum? Is there a palette with mathematical symbols one can use?  All I see are the symbols for bold, italics, underline, subscripts, superscripts, etc.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/03/2014 07:39 pm
"Images can be embedded into posts. "

SMF has the ability to recognize and parse HTML or XHTML code in board's description. Just add something like this to your description:
Code: [Select]

<img src="mypic.gif" width="70" height="17" alt="" />

Where:

    img="mypic.gif" - is the name of the image. If it is not located in the forum's base directory, it will be necessary to include the path to it (i.e. img="./Themes/default/images/mypic.gif");
    width="70" - is the width in pixels of the image.
    height="17" - is the height in pixels of the image.
    alt="" - is an alternative text to display if, for any reason, the image does not load correctly in visitors' browser. If the image has no real utility except aesthetics, it can be left empty. Otherwise it would be appropriate to explain in one word or two what the image represents.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/03/2014 08:21 pm
Lower right hand corner of the first page here, you can see the primary source material for this dating back 1/4 century:

http://arc.aiaa.org/doi/abs/10.2514/3.23219?journalCode=jpp

Obviously the negative mass is chasing the positive mass.  BTW, in case it escaped anyone's notice, for this to work, you need to connect the two masses rigidly, and the force exerted will be gravitic, so you need VERY large masses for this to be practical.  Woodward's impulse engine seems to me much more viable in the practical sense and because it too takes advantage of the self-acceleration of negative mass, it can be fantastically efficient.

MET's driven past dm=m tap into this negative mass contribution.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 08:27 pm
Lower right hand corner of the first page here, you can see the primary source material for this dating back 1/4 century:

http://arc.aiaa.org/doi/abs/10.2514/3.23219?journalCode=jpp

Obviously the negative mass is chasing the positive mass.  BTW, in case it escaped anyone's notice, for this to work, you need to connect the two masses rigidly, and the force exerted will be gravitic, so you need VERY large masses for this to be practical.  Woodward's impulse engine seems to me much more viable in the practical sense and because it too takes advantage of the self-acceleration of negative mass, it can be fantastically efficient.

MET's driven past dm=m tap into this negative mass contribution.

Where does Forward contradict Bondi?  As I started reading this Forward is actually quoting Bondi.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/03/2014 08:41 pm
Its been many years since I studied this myself, but I think Forward generally gets credit for the drive concept because he noted the backward inertial contribution first.  OTOH, I do recall it being called a "Bondi propeller" as well, so who gets credit for it I'm not certain.  Woodward mentions this in his book but doesn't take sides.  He just notes that indeed, even physicists neglect the fact the negative inertia reverses the reversed gravity and makes negative mass fall toward rather than away from positive mass.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 08:45 pm
Its been many years since I studied this myself, but I think Forward generally gets credit for the drive concept because he noted the backward inertial contribution first.  OTOH, I do recall it being called a "Bondi propeller" as well, so who gets credit for it I'm not certain.  Woodward mentions this in his book but doesn't take sides.  He just notes that indeed, even physicists neglect the fact the negative inertia reverses the reversed gravity and makes negative mass fall toward rather than away from positive mass.

You wrote that many Physicists make an error concerning negative mass and positive mass in reference to  my explanation of what Bondi wrote.  I thought you were saying that Bondi had made an error concerning how negative and positive masses would interact.

By the way, Bondi was a renowned physicist, he developed a steady state theory with Fred Hoyle and had  important contributions to the theory of general relativity.  I can't comment on Forward, from the paper you cite it looks like he is explaining Bondi's results to an aerospace engineering audience and discussing Bondi's interaction as a propulsion model. (This was not Bondi's intention, to my knowledge.  In the paper I quoted Bondi uses General Relativity just to predict how they would interact).
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 09:03 pm
HELP:

I'm modeling the coupled nonlinear differential equations of NASA's Eagleworks inverted torsional pendulum with Mathematica.  One important value needed is the damping constant provided by the magnetic damper.  I can't find this among the data provided either in the "Anomalous Thrust ..." report or the data given by Paul March.

I found that LIGO ( Laser Interferometer Gravitational Wave Observatory) performed an engineering analysis for their pendulum (a completely different type of pendulum) looking at different types of dampers, including magnetic dampers in the range of

Damping ~ 6 kg/s = 6 N s/m

Please let me know whether any of you can suggest a better value or has an idea of the damping coefficient used for the experiments at NASA Eagleworks.  Of course magnetic dampers for industrial applications can go up to values of 210 000 N s/m but they are much larger than what the NASA Eagleworks report shows.
Title: Re: EM Drive Developments
Post by: JasonAW3 on 10/03/2014 09:37 pm
In the case as presented, it sort of appears that the electron stream, may be being concentrated and accelerated to increse their effective mass.

They are not claiming that mass, regardless of its elemental particle composition, including electrons, is coming out of the device.

Ok,

As far as I can tell then, it simply shouldn't work.

If you're using RF frequencies, then they are transmitting an electron stream, but where is the stream going?  Unless they have figured out some way of converting electrons into kenitic energy, I can't with any conventional physics, see how this could work.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 09:51 pm
http://arxiv.org/abs/1302.2775

This paper is compelling in my view. It is written from the point of view of spherical shapes so keep that in mind if you read this. At the conclusion factor in the conical shape of the emdrive and remember the stuff I posted earlier concerning casimir energies and 3d shapes and cavities. Spheres attract externally but repulse internally across a diameter. Cones do the same but scatter because of their asymmetry, causing an imbalance.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 09:55 pm
In the case as presented, it sort of appears that the electron stream, may be being concentrated and accelerated to increse their effective mass.

They are not claiming that mass, regardless of its elemental particle composition, including electrons, is coming out of the device.

Ok,

As far as I can tell then, it simply shouldn't work.

If you're using RF frequencies, then they are transmitting an electron stream, but where is the stream going?  Unless they have figured out some way of converting electrons into kenitic energy, I can't with any conventional physics, see how this could work.
I just want to say that rf is photons.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 10:14 pm
http://arxiv.org/abs/1302.2775

This paper is compelling in my view. It is written from the point of view of spherical shapes so keep that in mind if you read this. At the conclusion factor in the conical shape of the emdrive and remember the stuff I posted earlier concerning casimir energies and 3d shapes and cavities. Spheres attract externally but repulse internally across a diameter. Cones do the same but scatter because of their asymmetry, causing an imbalance.
The paper's title:  Inertia from an asymmetric Casimir effect.  It does not mention Sciama's explanation for inertia.

Abstract:

The property of inertia has never been fully explained. A model for inertia
(MiHsC or quantised inertia) has been suggested that assumes that
1) inertia is due to Unruh radiation and 2) this radiation is subject to
a Hubble-scale Casimir effect. This model has no adjustable parameters
and predicts the cosmic acceleration, and galaxy rotation without dark
matter, suggesting that Unruh radiation indeed causes inertia, but the
exact mechanism by which it does this has not been specified. The mechanism
suggested here is that when an object accelerates, for example to
the right, a dynamical (Rindler) event horizon forms to its left, reducing
the Unruh radiation on that side by a Rindler-scale Casimir effect whereas
the radiation on the other side is only slightly reduced by a Hubble-scale
Casimir effect. This produces an imbalance in the radiation pressure on
the object, and a net force that always opposes acceleration, like inertia



Pendry et al. (2006) and Leonhardt (2006).. have demonstrated theoretically
that radiation of a given wavelength can be bent around an object
(which must be smaller than the wavelength) using a metamaterial, making that
object invisible to an observer at that wavelength. It may be possible instead,
to set up a metamaterial to reflect radiation in such a way that an artificial
event horizon is formed. Then according to the model discussed here, this will
damp Unruh radiation on one side of the object which would then be accelerated
towards the metamaterial.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 10:25 pm
http://arxiv.org/abs/1302.2775

This paper is compelling in my view. It is written from the point of view of spherical shapes so keep that in mind if you read this. At the conclusion factor in the conical shape of the emdrive and remember the stuff I posted earlier concerning casimir energies and 3d shapes and cavities. Spheres attract externally but repulse internally across a diameter. Cones do the same but scatter because of their asymmetry, causing an imbalance.

I noticed that somebody (you ?) invited him to this forum. I applaud the invitation.  Hopefully he comes.  He is definitely welcome  :)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 10:45 pm
Gravitation hasn't been shown to communicate outside its local spacetime curvature or even proven it is field theoretic. No gravity waves. Einstein said it was local curvature in spacetime. No ripples to communicate via in spacetime have been found. Find one gravity wave and gravitational Inertia will work. Even non locally across the cosmos because phase velocities are superluminal. Gravity is a how not a why. I'm surprised Feynman invented mathematical time travel to shoehorn that view of Inertia. This is fun.

Also wmap has shown a lumpy cosmos with a dipole anisotropy. Here at home we are dominated by the mass of a planet moon and star and a supermassive blackhole, none of which contribute to any inertial dipole moments.

I invited him. I hope he gets over here. His credentials and willingness to communicate leveraging the Internet are awesome.

Edit: I want to clarify my comments above about gravity being a field. I clearly was in error saying this. What I'm unsuccessfully trying to communicate is that locally, gravity doesn't appear as a force, but from a distance where the curve of space time in which mass "falls" is visible and so it an object's motion along it, a force is apparent. I shouldn't have used the word field.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 11:15 pm
Scheme to detect Unruth Radiation by

SLAC National Accelerator Laboratory (operated by Stanford University on behalf of the DOE)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 11:31 pm


Easier to just accelerate a thermometer.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 11:40 pm
Scheme for Detecting Unruth Radiation (Stanford)

Easier to just accelerate a thermometer.
You are going to need an extremely high acceleration:

2.5 × 10^20 m/s^2 corresponds to a temperature of 1 K

for comparison, the Space Shuttle acceleration was only 29 m/s^2

and/or an extremely precise thermometer....

with the most precise thermometer you may be able to measure to a precision of  ~10 X 10^(-9) of a degree K.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/03/2014 11:49 pm
Scheme for Detecting Unruth Radiation (Stanford)

Easier to just accelerate a thermometer.
You are going to need an extremely high acceleration:

2.5 × 10^20 m/s^2 corresponds to a temperature of 1 K

for comparison, the Space Shuttle acceleration was only 29 m/s^2

and/or an extremely precise thermometer....

I agree. Thanks for the math.
Title: Re: EM Drive Developments
Post by: Rodal on 10/03/2014 11:58 pm
Scheme for Detecting Unruth Radiation (Stanford)

Easier to just accelerate a thermometer.
You are going to need an extremely high acceleration:

2.5 × 10^20 m/s^2 corresponds to a temperature of 1 K

for comparison, the Space Shuttle acceleration was only 29 m/s^2

and/or an extremely precise thermometer....

I agree. Thanks for the math.

Interesting to notice the following in Unruth radiation:

temperature/acceleration =h / (2 Pi c kB ),

Planck constant, Pi,  Speed of Light, Boltzmann constant,  all together.  I find that very neat !

same as in Hawking radiation (with acceleration=g for a black hole)
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/04/2014 12:05 am
Scheme for Detecting Unruth Radiation (Stanford)

Easier to just accelerate a thermometer.
You are going to need an extremely high acceleration:

2.5 × 10^20 m/s^2 corresponds to a temperature of 1 K

for comparison, the Space Shuttle acceleration was only 29 m/s^2

and/or an extremely precise thermometer....

with the most precise thermometer you may be able to measure to a precision of  ~10 X 10^(-9) of a degree K.

Railguns come a little closer. At 32 megajoules, BAE's prototype pushed ~588,000 m/s². ;)
Title: Re: EM Drive Developments
Post by: frobnicat on 10/04/2014 12:09 am
For two positive masses, nothing changes and there is a pull on each other causing an attraction. Two negative masses would produce a pull on one another, but would repel because of their negative inertial masses. For different signs there is a push that repels the positive mass but attracts the negative mass.

Bondi pointed out that two objects of equal and opposite mass would produce a constant acceleration of the system towards the positive-mass object.[citation needed] However, the total mass, momentum and energy of the system would remain 0.

This behavior is completely inconsistent with a common-sense approach and the expected behaviour of 'normal' matter; but is completely mathematically consistent and introduces no violation of conservation of momentum or energy. If the masses are equal in magnitude but opposite in sign, then the momentum of the system remains zero if they both travel together and accelerate together, no matter what their speed:


And equivalently for the kinetic energy :


Forward extended Bondi's analysis to additional cases, and showed that even if the two masses m(-) and m(+) are not the same, the conservation laws remain unbroken. This is true even when relativistic effects are considered, so long as inertial mass, not rest mass, is equal to gravitational mass.

This behaviour can produce bizarre results: for instance, a gas containing a mixture of positive and negative matter particles will have the positive matter portion increase in temperature without bound. However, the negative matter portion gains negative temperature at the same rate, again balancing out. Geoffrey A. Landis pointed out other implications of Forward's analysis,[2] including noting that although negative mass particles would repel each other gravitationally, the electrostatic force would be attractive for like-charges and repulsive for opposite charges.

Forward used the properties of negative-mass matter to create the diametric drive, a design for spacecraft propulsion using negative mass that requires no energy input and no reaction mass to achieve arbitrarily high acceleration.

mm, from your understanding (or maybe stated by Forward himself ?) such a diametric drive is a cheap energy generator ? Not free as total mass-energy would be kept constant at 0, but cheap as locally unlimited steady power source.
If such arrangement can accelerate, surely it can push at no acceleration (no ?) : push at constant speed (relative to a massive ground) can create energy. Make it on a circular track around the earth for instance, store the recovered energy : this mass equivalent output of this generator must be compensated by an increase (in absolute value) of the negative mass that is chasing the positive one ? Or the positive mass decreased ? What that theory would have to say as to how mass is kept constant overall in this thought experiment ? I suspect this leads us to a possibility of a device that can forever radiate both negative and positive mass, the later could be converted to energy while the former would just be let free to escape far away. Getting unlimited energy source by just radiating away tons of negative mass as debt never to be paid. This is brilliant ! That should easily find some financial backer.

Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 12:18 am
...Getting unlimited energy source by just radiating away tons of negative mass as debt never to be paid. This is brilliant ! That should easily find some financial backer.
Or another way to show to people that negative mass is not likely to exist in reality.

We can still enjoy it virtually in science-fiction plots  :)
Title: Re: EM Drive Developments
Post by: Stormbringer on 10/04/2014 12:43 am
any wormhole that you can poke a single electromagnetic wave or (for negative mass) a massive particle of any type through will do for demonstrating negative mass or energy is real. Cosmic back reaction. the ultimate (nearly) free lunch.
Title: Re: EM Drive Developments
Post by: aceshigh on 10/04/2014 01:21 am
Getting unlimited energy source by just radiating away tons of negative mass as debt never to be paid. This is brilliant ! That should easily find some financial backer.

 Interesting, but how about energy from other universes? How about setting up an Electron Pump, by sending tungsten to paramen in a parallel universe with stronger Strong Nuclear Force, and getting Plutonium 186 in return? You know, because in the alternate universe with stronger strong nuclear force, the protons are held together against their own electrostatic force, needing less neutrons to do so. As soon as Plutonium 186 arrives in our universe, with a weaker strong nuclear force, it has an "scarcity of neutrons" and it will start irradiating positrons, liberating energy in the process... to each positron released, a proton is turned into a neutron.

After some time, 20 protons will have turned to neutrons and Plutonium 186 will become Tungsten 186. And all those positrons will annihilate some electrons creating even more energy!

It´s interesting for the paramen (the inhabitants of the parallel universe) because our Tungsten 186 sent there is also unstable... too many neutrons, or too few protons. The Tungsten 186 neutrons will start releasing electrons, creating energy, as neutrons turn into protons.

Thus, the cycle can go on forever, as we send them Tungsten 186 which becomes Plutonium 186 there and gives them energy, and they send us the Plutonium 186 which releases energy as it turns into Tungsten 186 here. FREE ENERGY!

Of course, this leak between the different laws in the two universes will tend to stabilize both universes to a thermodynamic equilibrium. And even small changes in the strong nuclear force in OUR universe would cause small stars as our sun to go supernova... and very soon!

edit: in case you guys never read Isaac Asimov, that´s the basic plot behind the novel The God's Themselves.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 01:23 am
Given what I've researched today (linked to earlier) I'm predicting it is easier to accelerate a conductive cone (pointy end first) than a sphere under very high energy conditions and acceleration. I think that under normal every day conditions the effect would be insignificant. Both internal and external boundary conditions are important to emdrive. Seems logical to me that the Nasa test article would produce more thrust while rotated pointy end up than down due to acceleration of gravity, barely. I need help formalizing this. Prove me wrong.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 01:42 am
Given what I've researched today (linked to earlier) I'm predicting it is easier to accelerate a conductive cone (pointy end first) than a sphere under very high energy conditions and acceleration. I think that under normal every day conditions the effect would be insignificant. Both internal and external boundary conditions are important to emdrive. Seems logical to me that the Nasa test article would produce more thrust while rotated pointy end up than down due to acceleration of gravity, barely. I need help formalizing this. Prove me wrong.
An interesting test:

The NASA Eagleworks tests showed that with the PTFE ("Teflon") dielectric resonator removed there was NO measurable thrust. 

Can you predict that removing the dielectric resonator will result in no measurable thrust?



Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 01:44 am
Already did. In earlier post. I suggested PVDF is better.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 01:48 am
Given what I've researched today (linked to earlier) I'm predicting it is easier to accelerate a conductive cone (pointy end first) than a sphere under very high energy conditions and acceleration. I think that under normal every day conditions the effect would be insignificant. Both internal and external boundary conditions are important to emdrive. Seems logical to me that the Nasa test article would produce more thrust while rotated pointy end up than down due to acceleration of gravity, barely. I need help formalizing this. Prove me wrong.

Another test:

the Cannae drive is shaped like a pillbox (see picture).  It is symmetric except for the dielectric resonator being installed in the long pipe side.

Can you predict thrust for the Cannae drive?

Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 01:52 am
Already did. In earlier post. I suggested PVDF is better.
Here:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243723#msg1243723

and here:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243735#msg1243735
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 01:56 am
Given what I've researched today (linked to earlier) I'm predicting it is easier to accelerate a conductive cone (pointy end first) than a sphere under very high energy conditions and acceleration. I think that under normal every day conditions the effect would be insignificant. Both internal and external boundary conditions are important to emdrive. Seems logical to me that the Nasa test article would produce more thrust while rotated pointy end up than down due to acceleration of gravity, barely. I need help formalizing this. Prove me wrong.

Another test:

the Cannae drive is shaped like a pillbox (see picture).  It is symmetric except for the dielectric resonator being installed in the long pipe side.

Can you predict thrust for the Cannae drive?

I don't think I said this here, but I marked up the Nasa paper with a line showing where to lop off the bell because it makes no difference. Just the tube with dielectric in it. Those are the only active useful parts. The area where the tube meets the bell is tapered like a very short cone too.

edit, er bell I mean pillbox.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 02:02 am
Already did. In earlier post. I suggested PVDF is better.
Here:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243723#msg1243723

and here:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243735#msg1243735

You mean

Polyvinylidene difluoride (it is yet another thermoplastic fluoropolymer).

Why do you like it? Because of its high piezoelectric effect compared to PTFE ?  It has a negative d33 value (it will compress instead of expand when exposed to an electric field). It is anisotropic (crystalline)

Or because of its heat resistance? Or something else?

Is there a phase you prefer? alpha , beta , or gamma phases ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 02:18 am
Already did. In earlier post. I suggested PVDF is better.
Here:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243723#msg1243723

and here:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243735#msg1243735

You mean

Polyvinylidene difluoride (it is yet another thermoplastic fluoropolymer).

Why do you like it? Because of its high piezoelectric effect compared to PTFE ?  It has a negative d33 value (it will compress instead of expand when exposed to an electric field). It is anisotropic (crystalline)

Or because of its heat resistance? Or something else?

Is there a phase you prefer? alpha , beta , or gamma phases ?

I was wanting to use large 1x2 meter sheets layered together to store energy for electric cars or something. I abandoned it when I learned that it has a low Curie temperature. But it is highly polarizable and ferroelectric. I was also trying to tie it in with Abraham-Minkowski.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 02:22 am
Given what I've researched today (linked to earlier) I'm predicting it is easier to accelerate a conductive cone (pointy end first) than a sphere under very high energy conditions and acceleration. I think that under normal every day conditions the effect would be insignificant. Both internal and external boundary conditions are important to emdrive. Seems logical to me that the Nasa test article would produce more thrust while rotated pointy end up than down due to acceleration of gravity, barely. I need help formalizing this. Prove me wrong.

Another test:

the Cannae drive is shaped like a pillbox (see picture).  It is symmetric except for the dielectric resonator being installed in the long pipe side.

Can you predict thrust for the Cannae drive?

Here:

(http://)
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 02:28 am
Already did. In earlier post. I suggested PVDF is better.
Here:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243723#msg1243723

and here:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1243735#msg1243735

You mean

Polyvinylidene difluoride (it is yet another thermoplastic fluoropolymer).

Why do you like it? Because of its high piezoelectric effect compared to PTFE ?  It has a negative d33 value (it will compress instead of expand when exposed to an electric field). It is anisotropic (crystalline)

Or because of its heat resistance? Or something else?

Is there a phase you prefer? alpha , beta , or gamma phases ?

I was wanting to use large 1x2 meter sheets layered together to store energy for electric cars or something. I abandoned it when I learned that it has a low Curie temperature. But it is highly polarizable and ferroelectric. I was also trying to tie it in with Abraham-Minkowski.
1) What do you make of the comment from the AviationWeek/etc. reporter that said he had an e-mail from Shawyer saying that Shawyer doesn't use any dielectric?  (Shawyer started with ferrites, then switched to dielectric polymers, now he says he removed them, not clear whether he has nothing or went back to ferrites)

2) Since the action is taking place in the dielectric, do you think it would be better to have a waveguide with dielectric resonators spaced like in this picture? [hint: if one clicks on the picture it gets larger and one can see more detail]
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/04/2014 02:40 am
Interesting, but how about energy from other universes?

I'm far too frustrated by having had an actual Stolichnaya martini tonite, thanks to Elizabeth, my mixoligist. who drinks these things, anyhow?

Bottom line.   Forget about "other universes".

And what the heck does Rodal see in martinis?  Probably he's totally wrong in his math as well.  Solo dicendo.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 02:46 am
Well early on I was trying to explain it all away as a momentum transfer from photons to the cavity via the dielectric (Abraham-Minkowski) which may be part of it, or at least at these low energies, most of it. For the life of me I couldn't think of a way to transfer any momentum to the QV and I had a lot of even crazier ideas early on with a bunch of Unruh this or that in it. But I always maintained that the dielectric was essential until yesterday pretty much when I discovered the work of Dr Mike McCulloch. I was grabbing at a bunch of ideas until the casimir stuff became clearer to me. I think the dielectric in the waveguide would do best at half wave intervals. Since the test article was a cone, transverse waves go along a radius not around if I remember right, so the pic can't help us. Probably screwed that up but the jist is in circular waveguides you have TEM vectors, square/rectangular just TE.

I have very low confidence we'll ever have the technology to achieve the kind of energies and accelerations necessary to make this thing useful. It may appear plausible but not practical. Maybe we'd be better off using sound instead of rf and use a sound room to create boundaries. Either that and shrink down the cavities, cluster them in a wafer, cap them, and pump very high ghz or thz frequencies into them.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 02:55 am
Gravitation hasn't been shown to communicate outside its local spacetime curvature or even proven it is field theoretic. No gravity waves. Einstein said it was local curvature in spacetime. No ripples to communicate via in spacetime have been found. Find one gravity wave and gravitational Inertia will work. Even non locally across the cosmos because phase velocities are superluminal. Gravity is a how not a why. I'm surprised Feynman invented mathematical time travel to shoehorn that view of Inertia. This is fun.

Also wmap has shown a lumpy cosmos with a dipole anisotropy. Here at home we are dominated by the mass of a planet moon and star and a supermassive blackhole, none of which contribute to any inertial dipole moments.

I invited him. I hope he gets over here. His credentials and willingness to communicate leveraging the Internet are awesome.

He also went through the trouble to answer a question posed on his paper at stackexchange:  http://physics.stackexchange.com/questions/54313/does-unruh-radiation-replace-the-cosmic-horizon-radiation/54447#54447

That's a positive sign.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 03:35 am
Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html


Title: Re: EM Drive Developments
Post by: frobnicat on 10/04/2014 10:01 am
...Getting unlimited energy source by just radiating away tons of negative mass as debt never to be paid. This is brilliant ! That should easily find some financial backer.
Or another way to show to people that negative mass is not likely to exist in reality.

We can still enjoy it virtually in science-fiction plots  :)

Or that it may exist but can't be put at work in a rigid arrangement relative to positive mass (like in a diametric drive) because it would be space-like trajectories while positive mass is always time-like ? Aren't negative mass what is called tachyons and always moving >c, or am I mixing two different concepts ?
Mmm, that could allow for the existence of negative mass but preventing divergent instabilities (forever chasing...) since both couldn't interfere for long time...
Not sure this is a definitive answer also, maybe we could still devise how two streams of periodic lumps of positive/negative mass could still forever interfere even if one is <c and the other >c. A circular stream of tachyons... my brain hurts, any contradictions with causality ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 11:53 am
Silly question and may sound of topic but I assure you it is relevant. Are causality and information conjugate variable pairs?
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 11:56 am
...Getting unlimited energy source by just radiating away tons of negative mass as debt never to be paid. This is brilliant ! That should easily find some financial backer.
Or another way to show to people that negative mass is not likely to exist in reality.

We can still enjoy it virtually in science-fiction plots  :)

 Aren't negative mass what is called tachyons and always moving >c, or am I mixing two different concepts ?
Mmm, that could allow for the existence of negative mass but preventing divergent instabilities (forever chasing...) since both couldn't interfere for long time...


Different types of masses.  The rest mass of a tachyon (if it exists  :)   ) must be imaginary, because the denominator of E = m c^2 /Sqrt[1 - (v/c)^2],  (square root of one minus the square ratio of the velocity divided by c) is imaginary because it is traveling faster than light and the square root of a negative number is imaginary.  In order for the energy of the tachyon to be real, the rest mass must be imaginary so that when the (imaginary) rest mass  is divided by the (imaginary) denominator, "i" cancels out and the energy becomes a real number.

So you have:

Positive Mass (the mass we know exists, this includes antimatter and dark matter)

Negative Mass (science fiction mass for stabilizing wormholes)

Imaginary Mass  (science fiction mass for faster than light travel)

People going to Mass (reality or fiction ?)   ;)
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 12:14 pm
Silly question and may sound of topic but I assure you it is relevant. Are causality and information conjugate variable pairs?
They are very  much related as I think you know.  Time travel to the past poses great paradoxes both with causality (killing your grandfather paradox) and information (sending present information to the past).  Also both causality and information can be expressed in terms of entropy of course.

And the reason you asked is ?................
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/04/2014 12:16 pm
Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html

VERY nice and exhaustively done !  Have you seen the same sort of thing for dielectric resonators ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 12:24 pm
Silly question and may sound of topic but I assure you it is relevant. Are causality and information conjugate variable pairs?
They are very  much related as I think you know.  Time travel to the past poses great paradoxes both with causality (killing your grandfather paradox) and information (sending present information to the past).  Also both causality and information can be expressed in terms of entropy of course.

And the reason you asked is ?................

Rindler horizons. I'm trying to figure it out and prove it wrong. I'm torn if causality and information are really conjugate variable pairs in the spirit of symmetry in Noether's theorem/or are they thermodynamic. The internet isn't helping me much.

This problem is related to a whole other obsession I had since I learned about "A new kind of Science" where I was trying to make sense of information and computation giving rise to the universe. My head hurts. Information/Matter/Energy keep coming back to haunt me and I'm certain they are unified and conserved together somehow. Like how and gates run hotter than or gates. These ideas come full circle.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 12:35 pm
Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html

VERY nice and exhaustively done !  Have you seen the same sort of thing for dielectric resonators ?

There is a huge volume of information concerning Abraham Minkowski momentum and I've found it all to be contradictory and not helpful. They just gotta measure it and see.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 12:41 pm
Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html

VERY nice and exhaustively done !  Have you seen the same sort of thing for dielectric resonators ?

There is a huge volume of information concerning Abraham Minkowski momentum and I've found it all to be contradictory and not helpful. They just gotta measure it and see.

If you include "hidden momentum" as done by Shockley (the inventor of the transistor) it may become clear. 
A theoretician cannot decide a constitutive law from an armchair, it needs to be measured.  The most a theoretician can do is (using frame-indifference and thermodynamics) is to narrow done the choices for proper stress and stress rate measures, and conjugate measures of strain and strain rate.

Similarly with the Abraham and Minkowski expressions.   Abraham forced symmetry from the beginning because on purpose he chose a symmetric stress tensor.

Minkowski  uses an unsymmetric stress tensor.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 12:47 pm
Silly question and may sound of topic but I assure you it is relevant. Are causality and information conjugate variable pairs?
They are very  much related as I think you know.  Time travel to the past poses great paradoxes both with causality (killing your grandfather paradox) and information (sending present information to the past).  Also both causality and information can be expressed in terms of entropy of course.

And the reason you asked is ?................

Rindler horizons. I'm trying to figure it out and prove it wrong. I'm torn if causality and information are really conjugate variable pairs in the spirit of symmetry in Noether's theorem/or are they thermodynamic. The internet isn't helping me much.

This problem is related to a whole other obsession I had since I learned about "A new kind of Science" where I was trying to make sense of information and computation giving rise to the universe. My head hurts. Information/Matter/Energy keep coming back to haunt me and I'm certain they are unified and conserved together somehow. Like how and gates run hotter than or gates. These ideas come full circle.

conjugate variable pairs in the spirit of symmetry in Noether's theorem/or are they thermodynamic

Definitely more thermodynamic.

Information theory provides an approach to study the dynamics which goes far beyond conservation laws and Noether's theorem. The conservation laws are not applicable to the dissipative and open systems.

For example, I am presently modeling the coupled nonlinear differential equations for the magnetically damped inverted pendulum that NASA Eagleworks used for their tests.
I used a Lagrangian to get the coupled nonlinear differential equations of motion.  However, the magnetic damping terms cannot be obtained from the Lagrangian because they are non-conservative, so they have  be obtained separately.

I use information theory for my business in the stock market.  No Noether's theorem There are no conservation laws in finance.  People make irrational decisions.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 12:59 pm
And the reason you asked is ?................

Rindler horizons. I'm trying to figure it out and prove it wrong...

You are to be congratulated for that.  Trying to prove wrong one's formulation is a true mark of science.  As @frobnicat stated: a scientist should put as much effort trying to prove something worng as she does trying to prove it right.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 01:01 pm
Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html

VERY nice and exhaustively done !  Have you seen the same sort of thing for dielectric resonators ?

There is a huge volume of information concerning Abraham Minkowski momentum and I've found it all to be contradictory and not helpful. They just gotta measure it and see.

If you include "hidden momentum" as done by Shockley it all becomes clear. 
A theoretician cannot decide a constitutive law from an armchair, it needs to be measured.  The most a theoretician can do is (using frame-indifference and thermodynamics) is to narrow done the choices for proper stress and stress rate measures, and conjugate measures of strain and strain rate.

Similarly with the Abraham and Minkowski expressions.   Abraham forced symmetry from the beginning because on purpose he chose a symmetric stress tensor.

Minkowski  uses an unsymmetric stress tensor.

Your comments are a perfect transition to what I've been putting together today. My reasoning is that pretty much every idea tossed around here on why emdrive might have produced a small force really boils down the one fundamental problem, that has many different solutions that aren't agreed on by everyone on the planet earth so it need examining further, the problem being the origin of inertial mass. It hasn't been figured out using the egghead approach so it needs to be measured experimentally. So I put together a list, not exhaustive, of every intrinsic/extrinsic possible candidate for the origin or inertial mass I can think of. Please help me complete the list. After we're done compiling theories, I intend to design experiments (if possible) to test, or find ones already done and accepted. Also help correct me if I butcher or don't communicate clearly the following.

I'll keep an edit on this thing til we have it nailed down.

Intrinsic:
Higgs: Rest mass/energy contribute to inertial mass and rest mass because GR predicts they are equivalent.
Newton: It is intrinsic because I said so. It just is.

Extrinsic:
EM ZPF, Haisch et al
Unruh zpf/casimir McCulloch et al
De Brogie Compton resonance Haisch Reuda
Cosmic gravity-Mach
Cosmic gravity modified by Wheeler/Feynman-Sciama
Edit forgot: causal, moving charged particles Bergman
Edit forgot: mass fluctuations Woodward


http://www.google.it/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0CC8QFjAC&url=http%3A%2F%2Fwww.commonsensescience.org%2Fpdf%2Farticles%2Finertial_mass.pdf&ei=GOAvVIPWJYSrPJnogIAG&usg=AFQjCNGT5DXFojND6Ft_jpIj4_wg-bhmIQ&bvm=bv.76802529,d.ZWU&cad=rja

http://www.calphysics.org/inertia.html




Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/04/2014 02:05 pm
For two positive masses, nothing changes and there is a pull on each other causing an attraction. Two negative masses would produce a pull on one another, but would repel because of their negative inertial masses. For different signs there is a push that repels the positive mass but attracts the negative mass.

Bondi pointed out that two objects of equal and opposite mass would produce a constant acceleration of the system towards the positive-mass object.[citation needed] However, the total mass, momentum and energy of the system would remain 0.

This behavior is completely inconsistent with a common-sense approach and the expected behaviour of 'normal' matter; but is completely mathematically consistent and introduces no violation of conservation of momentum or energy. If the masses are equal in magnitude but opposite in sign, then the momentum of the system remains zero if they both travel together and accelerate together, no matter what their speed:


And equivalently for the kinetic energy :


Forward extended Bondi's analysis to additional cases, and showed that even if the two masses m(-) and m(+) are not the same, the conservation laws remain unbroken. This is true even when relativistic effects are considered, so long as inertial mass, not rest mass, is equal to gravitational mass.

This behaviour can produce bizarre results: for instance, a gas containing a mixture of positive and negative matter particles will have the positive matter portion increase in temperature without bound. However, the negative matter portion gains negative temperature at the same rate, again balancing out. Geoffrey A. Landis pointed out other implications of Forward's analysis,[2] including noting that although negative mass particles would repel each other gravitationally, the electrostatic force would be attractive for like-charges and repulsive for opposite charges.

Forward used the properties of negative-mass matter to create the diametric drive, a design for spacecraft propulsion using negative mass that requires no energy input and no reaction mass to achieve arbitrarily high acceleration.

mm, from your understanding (or maybe stated by Forward himself ?) such a diametric drive is a cheap energy generator ? Not free as total mass-energy would be kept constant at 0, but cheap as locally unlimited steady power source.
If such arrangement can accelerate, surely it can push at no acceleration (no ?) : push at constant speed (relative to a massive ground) can create energy. Make it on a circular track around the earth for instance, store the recovered energy : this mass equivalent output of this generator must be compensated by an increase (in absolute value) of the negative mass that is chasing the positive one ? Or the positive mass decreased ? What that theory would have to say as to how mass is kept constant overall in this thought experiment ? I suspect this leads us to a possibility of a device that can forever radiate both negative and positive mass, the later could be converted to energy while the former would just be let free to escape far away. Getting unlimited energy source by just radiating away tons of negative mass as debt never to be paid. This is brilliant ! That should easily find some financial backer.
I think Bondi and Forward would both say that yes, since this system self-accelerates, it could be strapped to a flywheel and used to generate electricity, but the electricity is not free.  I'm not sure who showed the math first, it may have been Woodward; but generally, the accounting is done by the rest of the universe being accelerated in its expansion.  Basically, when you harvest gravinertial momentum, you are stealing momentum from the future of the universe.  This is why Tom Mayhood, when he was Woodward's master's student back in the 90's, posted on the door of the lab "Tomorrow's Momentum Today".

That said, what you're suggesting here seems quite unworkable to me.  Remember, this is gravitational force, not inertial.  To get useful forces using gravity, you need enormous masses.  If you want for example a ship that can accelerate at 1/6 Earth gee, you'd need a negative mass the size of the moon rigidly connected to a positive mass of equal size.  As it turns out, enormous negative masses are hidden all around us and you could generate a negative mass that size, but what are you going to use for the positive mass?  You'd need to strap the Moon to a generator.  Not a practical solution.

IMHO, it is not the gravitic consequences of M-E physics that are the most immediately exciting, but the inertial consequences.  The MET uses the ability to fluctuate inertia.  That's our first application.  One could argue the construction of a wormhole generator is more exciting, but my guess is that's a 15 year project.  Assuming Crammer is right in how to steer a wormhole, it would still take us 15 years to learn how to build reliable wormhole generators.  MET's we can build right now and start traveling our planetary system in earnest.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 02:29 pm
.....This problem is related to a whole other obsession I had since I learned about "A new kind of Science" where I was trying to make sense of information and computation giving rise to the universe. ...
Concerning Wolfram's "A new kind of science," do you use Wolfram's Mathematica ?  I use Mathematica a lot since version 1, was quite happy with version 9.  Disappointed with all the bugs in initial version 10.  They just came out with a patch for version 10, and I'm testing it now, while I continue to use my version 9 programs for my work.

_____

Concerning "where I was trying to make sense of information and computation giving rise to the universe" one problem is that ultimate reality seems to contain continuous fields: it is not just a discrete computation.  But of course, this is fairly philosophical, since we don't even have a satisfactory theory to encompass both quantum mechanics and general relativity.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/04/2014 02:34 pm
Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html

VERY nice and exhaustively done !  Have you seen the same sort of thing for dielectric resonators ?

There is a huge volume of information concerning Abraham Minkowski momentum and I've found it all to be contradictory and not helpful. They just gotta measure it and see.

If you include "hidden momentum" as done by Shockley (the inventor of the transistor) it may become clear. 
A theoretician cannot decide a constitutive law from an armchair, it needs to be measured.  The most a theoretician can do is (using frame-indifference and thermodynamics) is to narrow done the choices for proper stress and stress rate measures, and conjugate measures of strain and strain rate.

Similarly with the Abraham and Minkowski expressions.   Abraham forced symmetry from the beginning because on purpose he chose a symmetric stress tensor.

Minkowski  uses an unsymmetric stress tensor.
I didn't want to quibble with Dr. Rodel when he made this kind of statement the other day, but I would point out this seems to confuse the differences between a constitutive equation, which describes properties of a specific material for instance, and a constitutive relation, which can before general.  The statement that solid bulk mass stores energy in its interatomic bonds that changes under deformation is to the best of my knowledge true of all solids.  It is in fact a property of solids.  And there is no onus on a theoretician to measure this in order to form a proper generalization or induction.  Once one understands the mechanism, one can be perfectly justified in inferring that mechanism operates for every member of its class, namely solids.  What one can't do, is form an actual equation with specific quantities, because these are unique to the materials themselves.  But it's quite fair game to say solids experience delta internal energy during deformation.  That or you'd have to throw out inductive reasoning from science, which I for one am not willing to do.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/04/2014 02:43 pm
Gravity is a how not a why.

Two points for Gryffindor on that one.

Still, isn't it a property of matter?  If it should be a property, then the question is, how does it work.  If not a property, then I don't know the question to ask.

I marked up the Nasa paper with a line showing where to lop off the bell pillbox because it makes no difference.

Then what's the function of the "pillbox" after all?  It would seem that the very geometry of the apparatus is not conducive to maximizing the anomalous thrust.

Maybe we'd be better off using sound instead of rf and use a sound room to create boundaries.

I'd like you to expand on that idea a little bit.  Sound is at least metaphysically fundamental on one level, and physically all around us on another.  Plus, it can be used to levitate or manipulate objects in certain environments.  One question I would ask, is, at what frequency does sound no longer exist?  Both high end and low end.

Silly question and may sound of topic but I assure you it is relevant. Are causality and information conjugate variable pairs?

There is some kind of connection between information and causality. 

This is my intuition.  The obvious, extreme interpretation of that connection, from a pragmatic standpoint, should it be confirmed, would be teleportation.

The internet isn't helping me much.

This problem is related to a whole other nother obsession I had since I learned about "A new kind of Science" where I was trying to make sense of information and computation giving rise to the universe.

Fixed that for ya.

The problem that I had with Wolfram's book is that he has to assume that there is a preexisting "matrix", and that there has to be sufficient time for his single celled spreadsheet (Or whatever it's called) to create a universe.  It's a Godelian problem, I'd say.  That was my takehome from the book.

As an aside, a related problem, in my mind, would be the apparent irreducible complexity of the DNA molecule.  One faction insists on the faith that random matter, immediately upon it's creation at the big bang, embarks on evolution, which can only and inevitably, in the one universe that we witness, results in DNA and intelligent life.  This, despite there being no possible mechanism nor sufficient time to so evolve from randomness.

...why emdrive might have produced a small force really boils down the one fundamental problem, ... the problem being the origin of inertial mass.

What I bin sayin'.  Start with Sciama '53.

Quote
I'll keep an edit on this thing til we have it nailed down.

Thank you.  What I bin askin' for.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/04/2014 02:43 pm
A circular stream of tachyons... my brain hurts, any contradictions with causality?

Too much Stoli?   
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/04/2014 02:46 pm
...negative mass is not likely to exist in reality.

Later today, I'll be virtually enjoying laying down more mass in the camo shed.  Pix to follow.

You have your own mixologist?

What?  You don't?  In the interests of cultivating what are known as "greener pastures (http://thegreatkh.blogspot.com/2012/06/holiday-1938.html)", as was written in an recent portion of the Akashic record, and in saving on flight costs to LA, I do. 

People going to Mass.

Real people go to real Masses.

Of course, there's the Higg's boson which went to church.  Priest said, "We don't serve your kind here."  The boson replied, "Why not? Without me, there is no Mass!"

You guys jsut keep handing me the material, and I'll work with it.

I use information theory for my business in the stock market.  ...  There are no conservation laws in finance.  People make irrational decisions.

And yet, people exist in the universe, so there has to be some kind of as yet mysterious connection between irrationality, which is a form of information, and the causal universe.  Which ties into my brief comments to Mulletron about Wolfram above.

Mathematica

Do you happen to have an older version that would run on Win95 or Win2K?  That you could share or sell?  They wouldn't sell me an older version some years ago, when I asked.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 03:03 pm
Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html

VERY nice and exhaustively done !  Have you seen the same sort of thing for dielectric resonators ?

There is a huge volume of information concerning Abraham Minkowski momentum and I've found it all to be contradictory and not helpful. They just gotta measure it and see.

If you include "hidden momentum" as done by Shockley (the inventor of the transistor) it may become clear. 
A theoretician cannot decide a constitutive law from an armchair, it needs to be measured.  The most a theoretician can do is (using frame-indifference and thermodynamics) is to narrow done the choices for proper stress and stress rate measures, and conjugate measures of strain and strain rate.

Similarly with the Abraham and Minkowski expressions.   Abraham forced symmetry from the beginning because on purpose he chose a symmetric stress tensor.

Minkowski  uses an unsymmetric stress tensor.
I didn't want to quibble with Dr. Rodel when he made this kind of statement the other day, but I would point out this seems to confuse the differences between a constitutive equation, which describes properties of a specific material for instance, and a constitutive relation, which can before general.  The statement that solid bulk mass stores energy in its interatomic bonds that changes under deformation is to the best of my knowledge true of all solids.  It is in fact a property of solids.  And there is no onus on a theoretician to measure this in order to form a proper generalization or induction.  Once one understands the mechanism, one can be perfectly justified in inferring that mechanism operates for every member of its class, namely solids.  What one can't do, is form an actual equation with specific quantities, because these are unique to the materials themselves.  But it's quite fair game to say solids experience delta internal energy during deformation.  That or you'd have to throw out inductive reasoning from science, which I for one am not willing to do.
Well quibble you do, because it is all contained in the arbitrary definition of what is a solid.
Is glass a solid?
How about polymers? are polymers solid?
Aren't the dielectric materials we are discussing here (for the NASA Eagleworks tests) polymers like PTFE ? These are not perfect crystals.
What is a glass transition?

How about rubber? is rubber a solid?
How about non-newtonian liquids with elastic properties? They are not really liquids nor solids, yet they exist.
Even in metals, what if it is easier (as it often is) for energy to pile up dislocations, than for the energy to go into elastic deformation?
Is anything that is not a perfect crystal out of consideration ? Certainly not.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/04/2014 03:27 pm
Now I'm enjoying this ...........................
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 04:19 pm
Last thought before I take a break and sleep is that there is no way that dumping energy into a dielectric, be it a cap or piezoelectric electroactive polymer or whatever, the qed vacuum even, will contribute to the mass energy of that system. That mechanism is just polarization of charge. Lipo batteries don't gain weight and neither do caps. Their volume may expand but no more mass. Any effect of momentum transfer is something else. I don't know what. Scattering maybe. Like billiard balls impacting. Higher energies still, begin to ionize. Finally mass energy comes into play. Gamma rays ftw or Mhz /ghz for a neat toy.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/04/2014 04:38 pm
http://space.gotnewswire.com/news/particle-antiparticle-scientists-make-strange-discovery-capitalberg
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 04:47 pm
http://space.gotnewswire.com/news/particle-antiparticle-scientists-make-strange-discovery-capitalberg
Wow !

The Majorana fermion may have been finally found, after 77 years !
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/04/2014 04:51 pm
Well quibble you do, because it is all contained in the arbitrary definition of what is a solid.
Is glass a solid?
How about polymers? are polymers solid?
Aren't the dielectric materials we are discussing here (for the NASA Eagleworks tests) polymers like PTFE ? These are not perfect crystals.
What is a glass transition?

How about rubber? is rubber a solid?
How about non-newtonian liquids with elastic properties? They are not really liquids nor solids, yet they exist.
Even in metals, what if it is easier (as it often is) for energy to pile up dislocations, than for the energy to go into elastic deformation?
Is anything that is not a perfect crystal out of consideration ? Certainly not.
All definitions are arbitrary.  They are mere conventions.  According to the convention in English usage today. Solids are firm and stable in shape, do not include fluids and liquids and thus undergo internal energy changes under deformation.  You may call this arbitrary to stipulate, but stipulate we do.  Please let me know of you discover some exception to this convention.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 04:53 pm
Well quibble you do, because it is all contained in the arbitrary definition of what is a solid.
Is glass a solid?
How about polymers? are polymers solid?
Aren't the dielectric materials we are discussing here (for the NASA Eagleworks tests) polymers like PTFE ? These are not perfect crystals.
What is a glass transition?

How about rubber? is rubber a solid?
How about non-newtonian liquids with elastic properties? They are not really liquids nor solids, yet they exist.
Even in metals, what if it is easier (as it often is) for energy to pile up dislocations, than for the energy to go into elastic deformation?
Is anything that is not a perfect crystal out of consideration ? Certainly not.
All definitions are arbitrary.  They are mere conventions.  According to the convention in English usage today. Solids are firm and stable in shape, do not include fluids and liquids and thus undergo internal energy changes under deformation.  You may call this arbitrary to stipulate, but stipulate we do.  Please let me know of you discover some exception to this convention.
So, are polymers (like the PTFE dielectric resonator) according to you solids? Yes or No?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 04:55 pm
http://space.gotnewswire.com/news/particle-antiparticle-scientists-make-strange-discovery-capitalberg

Thanks! I learned something new!
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/04/2014 04:55 pm
Last thought before I take a break and sleep is that there is no way that dumping energy into a dielectric, be it a cap or piezoelectric electroactive polymer or whatever, the qed vacuum even, will contribute to the mass energy of that system.
Actually it does, by definition.  E=mc^2.  When you put joules into a cap, it weighs more.  It's just that c^2 is such a large number we would normally not notice the delta mass, but indeed delta there is.  This is the whole concept behind internal energy.

http://en.wikipedia.org/wiki/Internal_energy

Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/04/2014 04:56 pm
http://space.gotnewswire.com/news/particle-antiparticle-scientists-make-strange-discovery-capitalberg
Wow !

The Majorana fermion may have been finally found, after 77 years !

Being it's own antiparticle, is it related to the axion ?

http://iopscience.iop.org/1367-2630/16/8/082003/pdf/1367-2630_16_8_082003.pdf
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/04/2014 05:04 pm
So, are polymers (like the PTFE dielectric resonator) according to you solids? Yes or No?
Polymers are mixtures.  Parts are solid and parts are fluid.  Cured mostly yes, uncured mostly no.  You're being obtuse to no point.  My point was that the issue of "constitutive relation" is not a proscription against making general statements.  There is no doubt anyone can precise enough to make a general statement difficult or invalid in some way, but that is not the kind of example under consideration.  After all, Woodward only uses perovskite crystals.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 05:12 pm
Last thought before I take a break and sleep is that there is no way that dumping energy into a dielectric, be it a cap or piezoelectric electroactive polymer or whatever, the qed vacuum even, will contribute to the mass energy of that system.
Actually it does, by definition.  E=mc^2.  When you put joules into a cap, it weighs more.  It's just that c^2 is such a large number we would normally not notice the delta mass, but indeed delta there is.  This is the whole concept behind internal energy.

http://en.wikipedia.org/wiki/Internal_energy

Not applicable. Macro vs micro. Different physical system. Does a hot battleship weigh more than a cold one? Or a charged vs uncharged one? Internal energy is thermodynamics.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 05:29 pm
So, are polymers (like the PTFE dielectric resonator) according to you solids? Yes or No?
Polymers are mixtures.  Parts are solid and parts are fluid.  Cured mostly yes, uncured mostly no.  You're being obtuse to no point.  My point was that the issue of "constitutive relation" is not a proscription against making general statements.  There is no doubt anyone can precise enough to make a general statement difficult or invalid in some way, but that is not the kind of example under consideration.  After all, Woodward only uses perovskite crystals.
This is the point: this is a thread about "EM Drive Developments".  We are interested in the EM Drive experimental results of Shawyer, NASA Eagleworks, the Chinese University (Prof. Juan Yang), etc., and their possible theoretical explanations.

It is not a thread about "Woodward", it is not a thread about "Woodward's book."

Rather than quibble about semantics, and answer "according to Woodward", or definitions from English dictionaries (rather than physics), or as you last did "After all, Woodward only uses perovskite crystals" instead of specifically addressing the below-mentioned drives it would be most constructive if you could use the theories by Woodward that you sponsor and champion to conduct a calculation of what are your predicted thrusts of the Shawyer, NASA Eagleworks, the Chinese University (Prof. Juan Yang) experiments. 

Prof. Mike McCulloch has done this for the Shawyer drive using his theory for inertia and the Unruth effect.  @frobnicat, @aero, @notsosureofit, @mulletron and many others (to all: please forgive me for not including a full list) and I have endeavored to also conduct calculations on photonic explanations, dark matter explanations, electron explanations, Quantum Vacuum explanations, an artifact of the testing equipment, and other explanations.

If the theories you sponsor are relevant to this thread, please show us by using the theories you sponsor to perform calculations that can throw light on the nature of the above-mentioned experimental results.  Thank you.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/04/2014 06:00 pm
So putting on the "what-if" hat, if Majorana fermions can appear on a superconducting surface, can they appear on a dielectric surface using the topical insulator analogy, oscillate, and radiate axions to provide thrust ?

Edit: at a 2D surface there is the possibility of a non-linear oscillation and thereby frequency multiplication (pretty far fetched, Eh ?)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/04/2014 06:25 pm
So putting on the "what-if" hat, if Majorana fermions can appear on a superconducting surface, can they appear on a dielectric surface using the topical insulator analogy, oscillate, and radiate axions to provide thrust ?

Edit: at a 2D surface there is the possibility of a non-linear oscillation and thereby frequency multiplication (pretty far fetched, Eh ?)

Help me visualize this pls.
Title: Re: EM Drive Developments
Post by: birchoff on 10/04/2014 06:41 pm
...
Assuming Crammer is right in how to steer a wormhole
...

@ronstahl

Does some actually have a theory for steering a wormhole?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/04/2014 06:48 pm
If the theories you sponsor are relevant to this thread, please show us by using the theories you sponsor to perform calculations that can throw light on the nature of the above-mentioned experimental results.

IMHO, it is a mistake to make predictions of things like thrust, because there are far too many loose variables involved.  For instance, Woodward has never known what is the percentage of binder in any of his dielectrics, so there's no way to know just how much active mass there is in the thruster.  One can get around this to some degree, by using the k of the compound, but one is still left with several of these kinds of loose variables.  Capacitance that changes with temperature and the inductance that needs to be changed to z-match it, lack of thermal stability, changing electrical impedance with temperature that changes current and power in, even dielectric decay which can be very pronounced in short periods of time, etc.

No one who does this work makes predictions for good reasons.  Dr. White has traditionally been very free with his postdictions, but these always come after the data.  All he's doing is fitting his model to the data, which is a worthless enterprise, IMHO.  I've corrected him on this on numerous occasions and he continues to claim to make predictions when in fact, he does not.

You can do things like parametric studies, where when you have thrust you then change a single variable, and look to see if an effect like thrust scales with that variable (voltage, frequency, etc.), but that is about the best one should hope for so far as "prediction".  Even this is dicey since none of these proof of science iterations is capable of continuous thrust yet.  For this reason I have said, we will do the best proof of science demonstrations when we are doing proof of technology demonstrations.  We need first of all to see these things provided with thermal stability so they can be run continuously.  This is just doing good science.

So far as my involvement in this discussion, as it is a discussion about the possible explanations for supposed thrust found in these resonators, and as I have 7 years experience with them, and as I am familiar with the kinds of issues that often go overlooked when considering thrust from M-E, like the 1/4 wave v. 1/2 wave issue; I think I can make a real contribution here without using mathematica.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/04/2014 06:52 pm
So putting on the "what-if" hat, if Majorana fermions can appear on a superconducting surface, can they appear on a dielectric surface using the topical insulator analogy, oscillate, and radiate axions to provide thrust ?

Edit: at a 2D surface there is the possibility of a non-linear oscillation and thereby frequency multiplication (pretty far fetched, Eh ?)

Help me visualize this pls.

OK
http://www.theory.tifr.res.in/~hbar/PDF/ti.pdf
then if the teflon surface has the typical "telomer sticking up" structure w/ the monomers aligning in 2D "layers" (parallel monomer stacks")
So, the image is now of a multilayer which may have enough (luck) as to act as a topological insulator in which Majorana fermions can form and be driven by the RF energy input.
If things get that far there's a chance they would radiate axions (maybe even coherently w/ the photon directon ???

Told you it was a far-fetched chain of events.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/04/2014 06:54 pm
...
Assuming Crammer is right in how to steer a wormhole
...

@ronstahl

Does some actually have a theory for steering a wormhole?
Yes.   http://en.wikipedia.org/wiki/John_G._Cramer

I'm told his theory on this is online somewhere, but I've yet to find it.  I think he delivered an informal presentation of this at his big birthday bash about two years ago, but I still haven't found it.  He wrote the Foreward in Woodward's book, and his Transactional Interpretation of QM is beautifully consistent with both Woodward's work and QM, and IIUC, his thoughts on steering a wormhole were instigated by Woodward's work.
Title: Re: EM Drive Developments
Post by: mboeller on 10/04/2014 07:29 pm
maybe this links are helpful:

http://arxiv.org/abs/0906.1626  (AFAIK same information as in the "Kastner.pdf" from Cramers website 2009 )

http://en.wikipedia.org/wiki/Transactional_interpretation

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/04/2014 07:54 pm
Yes, and note the reliance upon Wheeler-Feynman Absorber theory in TIQM same as in M-E theory.  So really this notion of advanced and retarded waves traveling forward and backward in time to achieve an instantaneous result, is not so far fetched.  It solves problems in GR, QM and in how we understand Maxwell's equations.  People don't often note that there are two ways to solve those equations and it is arbitrary for us to use only the retarded wave.  Even the broader gravity theory has made use of this in Hoyle-Narliker.  We're prejudiced however, whenever we consider stuff moving backward in time since we don't observe this.  Hence why Cramer is still doing the work in entanglement, as this could provide powerful evidence for absorber theory in general, and his Transactional Interpretation in particular.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 08:01 pm
If the theories you sponsor are relevant to this thread, please show us by using the theories you sponsor to perform calculations that can throw light on the nature of the above-mentioned experimental results.

IMHO, it is a mistake to make predictions of things like thrust, because there are far too many loose variables involved.  For instance, Woodward has never known what is the percentage of binder in any of his dielectrics, so there's no way to know just how much active mass there is in the thruster.  One can get around this to some degree, by using the k of the compound, but one is still left with several of these kinds of loose variables.  Capacitance that changes with temperature and the inductance that needs to be changed to z-match it, lack of thermal stability, changing electrical impedance with temperature that changes current and power in, even dielectric decay which can be very pronounced in short periods of time, etc.

No one who does this work makes predictions for good reasons.  Dr. White has traditionally been very free with his postdictions, but these always come after the data.  All he's doing is fitting his model to the data, which is a worthless enterprise, IMHO.  I've corrected him on this on numerous occasions and he continues to claim to make predictions when in fact, he does not.

You can do things like parametric studies, where when you have thrust you then change a single variable, and look to see if an effect like thrust scales with that variable (voltage, frequency, etc.), but that is about the best one should hope for so far as "prediction".  Even this is dicey since none of these proof of science iterations is capable of continuous thrust yet.  For this reason I have said, we will do the best proof of science demonstrations when we are doing proof of technology demonstrations.  We need first of all to see these things provided with thermal stability so they can be run continuously.  This is just doing good science.

So far as my involvement in this discussion, as it is a discussion about the possible explanations for supposed thrust found in these resonators, and as I have 7 years experience with them, and as I am familiar with the kinds of issues that often go overlooked when considering thrust from M-E, like the 1/4 wave v. 1/2 wave issue; I think I can make a real contribution here without using mathematica.
OK, so according to your definition (a definition that I don't agree with from my R&D background in analysis of materials, but let's use it for your argument)  <<Polymers are mixtures.  Parts are solid and parts are fluid.  Cured mostly yes, uncured mostly no. >>, since the dielectrics used in the NASA Eagleworks experiments are thermoplastics (that obviously are not crosslinked and not capable of being "cured" like thermosets), they are not solids according to you.  Therefore according to your definition your theory is not capable of dealing with these dielectric materials.

Furthermore you state that you are not going to make any predictions of thrust concerning the Shawyer, NASA Eagleworks or Chinese University (Prof. Juan Yang) EM drives.

Therefore, until you notify me otherwise, my understanding from the above is that your theory is not capable of predicting thrust for the above mentioned EM drives.  Thank you.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/04/2014 08:14 pm
Oooo.  Oooo.  Spank me next!
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 08:17 pm
So putting on the "what-if" hat, if Majorana fermions can appear on a superconducting surface, can they appear on a dielectric surface using the topical insulator analogy, oscillate, and radiate axions to provide thrust ?

Edit: at a 2D surface there is the possibility of a non-linear oscillation and thereby frequency multiplication (pretty far fetched, Eh ?)

Help me visualize this pls.

OK
http://www.theory.tifr.res.in/~hbar/PDF/ti.pdf
then if the teflon surface has the typical "telomer sticking up" structure w/ the monomers aligning in 2D "layers" (parallel monomer stacks")
So, the image is now of a multilayer which may have enough (luck) as to act as a topological insulator in which Majorana fermions can form and be driven by the RF energy input.
If things get that far there's a chance they would radiate axions (maybe even coherently w/ the photon directon ???

Told you it was a far-fetched chain of events.

@notsosureofit, your explanation above (axionic dark matter), and (thanks to @mulletron for bringing this to our attention) Prof. Mike McCulloch's  Unruth-radiation explanation are turning out to be the most coherent, so far, explanations of the measured thrust forces. 
Also, they do not violate local conservation of momentum, and they are based on physics as discussed at major academic institutions, they just involve predicted but not yet experimentally verified matter (in the first case) or radiation (in the second case).

The Unruth-radiation requires (correct me I am wrong) less of "a far-fetched chain of events" and it is also ahead because one can make a "back of the envelope" tentative predictive analysis (as done by Prof. Mike McCulloch ) that is pretty close to the measured thrust forces.

From the experimental side at NASA Eagleworks we have the issues of the magnetic interaction between the magnetic damper and the power cable.  Also neither the Chinese University and the NASA Eagleworks (Cannae and truncated cone) experiments were yet conducted in a vacuum.

This is very exciting as, thanks to everybody involved in this thread, we have made real progress in analyzing these experiments.   :)

______________
PS: concerning the axionic dark matter explanation we still have to hear from @frobnicat on his warning that it maybe several orders of magnitude off the measurements.  I also have a concern due to some of the estimates made for the density of dark matter expected around our planet (being too low to explain the measurements), but that is an unsettled area of research.

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/04/2014 08:36 pm
Therefore, until you notify me otherwise, my understanding from the above is that your theory is not capable of predicting thrust for the above mentioned EM drives.  Thank you.
I explained this to you ten pages back.  Did you miss the memo?  I'll tell you again: Woodward's theory may or may not be able to explain thrusts from the EM drives, depending upon how the dielectric is placed inside the resonator.  If the field on the dielectric will generate an unbalanced mechanical action due to piezo or electrostrictive coefficients, then it is possible these devices are producing thrust due to M-E physics.  Specifically, since the thrust from these devices vanishes when the dielectric is removed, and since it is pronounced during the on/off switching transients, there is good reason to believe these are acting as poorly designed Mach Effect Thrusters.  However, regardless of the dielectric's acoustic geometry, M-E physics cannot explain thrust from a DC signal.  It can explain thrust impulses from switching transients, and AC signals, but not DC.  You've been reading the paper recently so you should be able to tell more easily than I whether the setup meets the criteria to be acting as a MET.

Someone here did a nice treatment of this and posted it over at T-P, noting 5 possible explanations for thrust from these devices.  I was unfamiliar with one, and I favor the M-E explanation.  The other three seemed to me obviously wrong, including the QVF conjecture.
Title: Re: EM Drive Developments
Post by: aceshigh on 10/04/2014 10:54 pm
you know, before we blame Ron Stahl for bringing Woodward Theory here, we should remember he arrived AFTER people started talking about Woodward Theory here.

Dr Rodal himself was talking about Woodward theory here before Ron Stahl arrived, exactly to correct some misunderstandings regarding Woodward Theory (or Mach Effect, like Woodward himself preffers to call it)


Btw, it´s also important to question if Paul March himself, who worked on the experiments, believe the results may have relation to Mach Effect.
Title: Re: EM Drive Developments
Post by: Rodal on 10/04/2014 11:09 pm
...regardless of the dielectric's acoustic geometry, M-E physics cannot explain thrust from a DC signal.  It can explain thrust impulses from switching transients, and AC signals, but not DC.  You've been reading the paper recently so you should be able to tell more easily than I whether the setup meets the criteria to be acting as a MET....

This is very useful information, thank you.  Could you be so kind as to review the following excerpt from the NASA Eagleworks report and let us know your opinion of whether "M-E physics" can explain thrust from the following signal:

p.8 <<During testing, the Test Engineer controls the RF frequency generation via a 0-to-28 volts dc power input to a voltage-controlled oscillator (VCO). The VCO RF signal output is passed to a variable voltage attenuator (VVA), the output of which is controlled by the Test Engineer via a 0-to-17 volts dc power input. Based upon the VVA output, the amplifier will output up to approximately 28 watts. Amplifier output passes to a dual-directional coupler (DDC), which allows forward and reflected power measurements to be obtained as the power is simultaneously passed to the test article input port. The Test Engineer monitors forward and reflected power and adjusts the input frequency to obtain the desired combination of cavity frequency and power delivery to the cavity.>>
Title: Re: EM Drive Developments
Post by: frobnicat on 10/04/2014 11:42 pm
_______
PS: concerning the axionic dark matter explanation we still have to hear from @frobnicat on his warning that it maybe several orders of magnitude off the measurements.  I also have a concern due to some of the estimates made for the density of dark matter expected around our planet (being too low to explain the measurements), but that is an unsettled area of research.

yes yes, me and my big mouth

Let's be clear that it's about the use of naturally occurring dark matter (be it light Axions rather than Wimps if the involved frequencies are indicative) and not about the production or use of dark matter considered in an "empty dark field" (gosh) that is at its rest state, lower point energy. The question were : is it worth to use this naturally occurring flow for momentum or energy? (which is the same as momentum = energy / c if we take the photon rocket as a proven baseline of "best spent mass_energy")

In fact I then tried a back of the envelope arithmetic like that :
    mass flow = density * average speed * device cross section
     kg/s = kg/m^3 * m/s * m^2
a few assumptions there :  the dark flow is homogeneous in density and speed (so I guess this discards hot dark matter). I'm also assuming 100% of dark mass going through the device is "used" somehow (which for a weakly interacting particle would be a rare manifestation of goodwill).

Then I went other equations, like F=mflow*Vej and Pow=0.5mflow*Vej^2, going through the energy it takes to push on such a flow to get the reported thrusts (powered "propeller" device, not just passive sailing, which I believe would have seen quite a strong dependence on sidereal time, no thrust reversal with reversal of device...) and with the idea of seeing if the necessary velocity of ejection is indeed higher than the average velocity of flow that brings mass (therefore validating some of the "propeller&slow wind" hypothesis). Sorry for the convoluted line of reasoning and slow brain tonight.

At about 1Gev/cm^3 (as seen on this seemingly optimistic paper (http://inspirehep.net/record/878672/files/arXiv%3A1011.6323.pdf), maybe more optimistic is possible) and .01m² csection and 250km/s dark flow velocity that is mflow=1e9*1.8e-36 (http://fr.wikipedia.org/wiki/%C3%89lectron-volt)/1e-6 * 2.5e5 * 1e-2 = 4.5e-18 kg/s.
With about 45*µN thrusters that yields Vej = F / mflow = 4.5e-5 / 4.5e-18 = 1e12m/s   ???
Pow = .5 mflow Vej² = :D = .5 * 4.5e-18 * 1e24 = 2.25 e6 = 2.25MW hence the 6 orders of magnitude boast (more like 5 actually with those numbers) when comparing to 20W power.
Since thing is relativistic I were humbled, and wrong to be starting with Newton. Seems you don't have the patience to wait a month before I gather my spirits around SR so...

The best use that could be made of recovering this mass flow : converting it to photons, sent collimated and push on expelled momentum. This is, standard, please feel free to disagree. Then just see the power equivalent of the dark mass flow and compare it with what we would get from that as a photon rocket :
darkPow = mflow c² = 4.5e-18 9e16 = .4 W and that would push at F=darkPow/c = .4/3e8 = 1.3 nN (nano Newton). Dark flow average velocity times mass flow also would impart a recoil of 2.5e5*4.5e-18 about 1e-12, a pN. This would be less efficient use of this incoming mass_energy flow (and incompatible with thrust reversion).

How does it (1.3nN) scales compared to the 45µN/20W numbers above? Well I don't know what the 20W have to do in it but to scale nN to 10s of µN is 4 order of magnitude higher, that is needs 100m² of "perfect dark harvestor" cross section, given 1GeV/cm^3 and 250km/s average dark flow. Maybe a strong dispersion in dark matter particles velocities around average velocity could make up for that, how hot is hot dark matter, could it be relativistic ?

Looks like that there is not enough dark matter though to be of practical value (in explaining the reported results in classical terms) since momentum benefit of harvesting dark mass and pushing on it can't beat the momentum you'd get from harvesting the energy and sending photons, and that energy is too low. Value of the "dark field" in BSM theories in another matter entirely.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 12:09 am
....
At about 1Gev/cm^3 (as seen on this seemingly optimistic paper (http://inspirehep.net/record/878672/files/arXiv%3A1011.6323.pdf), maybe more optimistic is possible) and .01m² csection and 250km/s dark flow velocity that is mflow=1e9*1.8e-36 (http://fr.wikipedia.org/wiki/%C3%89lectron-volt)/1e-6 * 2.5e5 * 1e-2 = 4.5e-18 kg/s.
With about 45*µN thrusters that yields Vej = F / mflow = 4.5e-5 / 4.5e-18 = 1e12m/s   ???
Pow = .5 mflow Vej² = :D = .5 * 4.5e-18 * 1e24 = 2.25 e6 = 2.25MW hence the 6 orders of magnitude boast (more like 5 actually with those numbers) when comparing to 20W power.
...
@frobnicat
Thanks!  This is progress.  Now perhaps we can get some feedback from @notsosureofit to continue with this interesting line of attack.

Definitely the density of dark matter is crucial.  I have now to find a paper I recall seeing some time ago from renowned people at Harvard, which (if I recall correctly) computed the amount of dark matter that should be in our vicinity.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 12:54 am
Even more crudely, I think you have to have either the new generation of axions (in quantity at low velocity) or a "cold" dark matter state that acts with a lot of self interaction (take your pick of quantum states at this point)

Edit:  1 Gev/cm^3 was the max I had heard.
Title: Re: EM Drive Developments
Post by: aero on 10/05/2014 12:55 am
@frobnicat

What is the .01m² csection that you refer to?

Maybe you told us the definition of terms before but I didn't find them in the last 20 pages, yesterday.

I wonder, because that equals 100 cm^2 or a square about 4 inches on a side and I don't recognize that dimension wrt the thruster cavity.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 01:04 am
Hmm, old memories, the cross section for a high Q antenna (assuming the cavity doe not shield axions) is a lot larger than the physical size.  I don't remember the relation but it been a long, long time.
Title: Re: EM Drive Developments
Post by: aero on 10/05/2014 01:29 am
Quote

2

down vote
 

According to Constraints on Dark Matter in the Solar System the following upper limits have been placed on dark matter in the solar system, based upon orbital motion of bodies in the solar system:

At the radius of Earth's orbit: 1.4×10 −19 g/cm 3 

At the radius of Mars's orbit: 1.4×10 −20 g/cm 3 

At the radius of Saturn's orbit: 1.1×10 −20 g/cm 3 

According to Local Density of Dark Matter, the density of dark matter at the Sun's location in the galaxy is 0.43GeV/cm 3   or 7.7×10 −25 g/cm 3 
 

http://arxiv.org/abs/1306.5534 (http://arxiv.org/abs/1306.5534)

http://arxiv.org/abs/1212.3670 (http://arxiv.org/abs/1212.3670)
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 01:57 am
Quote

2

down vote
 

According to Constraints on Dark Matter in the Solar System the following upper limits have been placed on dark matter in the solar system, based upon orbital motion of bodies in the solar system:

At the radius of Earth's orbit: 1.4×10 −19 g/cm 3 

At the radius of Mars's orbit: 1.4×10 −20 g/cm 3 

At the radius of Saturn's orbit: 1.1×10 −20 g/cm 3 

According to Local Density of Dark Matter, the density of dark matter at the Sun's location in the galaxy is 0.43GeV/cm 3   or 7.7×10 −25 g/cm 3 
 

http://arxiv.org/abs/1306.5534 (http://arxiv.org/abs/1306.5534)

http://arxiv.org/abs/1212.3670 (http://arxiv.org/abs/1212.3670)

Thanks @aero for this very interesting information

Wow

At the radius of Earth's orbit: 1.4×10 −19 g/cm 3

that is 7.868x10^4 GeV/cm^3 = 78680 GeV/cm^3

....
At about 1Gev/cm^3 (as seen on this seemingly optimistic paper (http://inspirehep.net/record/878672/files/arXiv%3A1011.6323.pdf), maybe more optimistic is possible) and .01m² csection and 250km/s dark flow velocity that is mflow=1e9*1.8e-36 (http://fr.wikipedia.org/wiki/%C3%89lectron-volt)/1e-6 * 2.5e5 * 1e-2 = 4.5e-18 kg/s.
With about 45*µN thrusters that yields Vej = F / mflow = 4.5e-5 / 4.5e-18 = 1e12m/s   ???
Pow = .5 mflow Vej² = :D = .5 * 4.5e-18 * 1e24 = 2.25 e6 = 2.25MW hence the 6 orders of magnitude boast (more like 5 actually with those numbers) when comparing to 20W power.
...

So @frobnicat used  1Gev/cm^3  which is 78680 times less than this estimate !

***there is also the question about the square cross section, previously posted by @aero ***

So now we are now much closer to the ballpark

https://www.youtube.com/watch?v=VYQVzkOkAyw
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/05/2014 02:41 am
Quote
So @frobnicat used  1Gev/cm^3  which is 78680 times less than this estimate !

***there is also the question about the square cross section, previously posted by @aero ***

So now we are now much closer to the ballpark

So 'microwave photon created dark matter axioms' are now a leading candidate for an explanation of the physics behind the Eagleworks thruster?  Looking for clarity here.  The revised Dark Matter numbers appear...close(?) to what is required, anyhow.

Also, monumentally stupid, maybe, but I'll ask anyhow.  Even a superficial surface looksee into Dark Matter reveals...informed speculation(?)...of a whole zoo of Dark Matter particles.  Maybe some of them have a bigger 'kick' than others?
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 02:55 am
Quote
So @frobnicat used  1Gev/cm^3  which is 78680 times less than this estimate !

***there is also the question about the square cross section, previously posted by @aero ***

So now we are now much closer to the ballpark

So 'microwave photon created dark matter axioms' are now a leading candidate for an explanation of the physics behind the Eagleworks thruster?  Looking for clarity here.  The revised Dark Matter numbers appear...close(?) to what is required, anyhow.

Also, monumentally stupid, maybe, but I'll ask anyhow.  Even a superficial surface looksee into Dark Matter reveals...informed speculation(?)...of a whole zoo of Dark Matter particles.  Maybe some of them have a bigger 'kick' than others?
Not much time to write now, but situation:

1) closest estimate is the one based on Unruth radiation
2) yes using the above mentioned estimate of dark matter + what @notsosureofit pointed out, axionic dark matter is a coherent explanation that is not so far away from the measurements

Have to run...
Title: Re: EM Drive Developments
Post by: aero on 10/05/2014 03:21 am
Quote
So @frobnicat used  1Gev/cm^3  which is 78680 times less than this estimate
question about the cross section,

I have no idea how the cross section should be estimated. I followed frobnicat's calculations but used the area of the small end of the truncated frustum thruster, which is about 0.044 m^2, and the density number above.

I calculate mflow= 1.55786E-12 kg/s compared to the earlier value of 4.5e-18 kg/s.

Of course I'm not even sure frobnicat was considering the truncated frustum thruster, he may be considering the Cannae device.
Title: Re: EM Drive Developments
Post by: aero on 10/05/2014 04:27 am
Quote
So @frobnicat used  1Gev/cm^3  which is 78680 times less than this estimate
question about the cross section,

I have no idea how the cross section should be estimated. I followed frobnicat's calculations but used the area of the small end of the truncated frustum thruster, which is about 0.044 m^2, and the density number above.

I calculate mflow= 1.55786E-12 kg/s compared to the earlier value of 4.5e-18 kg/s.

Of course I'm not even sure frobnicat was considering the truncated frustum thruster, he may be considering the Cannae device.

Tried to modify that post but somehow the modification was lost.

Continuing to substitute values into frobnicat's calculations, I calculate a value of Vej = 2.8886.E+07 m/s
so power = .5 mflow*Vej^2 = 6.4993.E+02 or 650 watts.

Hmm - How again did someone explain the lack of energy conservation? Or does the device scoop up enough dark matter (like an antenna) so that mass is higher, Vej is lower and energy is more like 17 watts?

I will calculate some more.

Edit add:

I get, roughly, these values using classic math,
momentum = mass*velocity and energy = .5 mass* velocity squared.

Vej, m/s   mflow, kg/s   power, watts
7.60E+05   5.92E-11   1.71E+01
9.00E+05   5.00E-11   2.03E+01

With these mass and velocity numbers, energy is conserved.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 07:03 am
Revised things a bit to further constrain extrinsic mechanisms between extrinsic Machian and extrinsic but local perturbations giving rise to inertial mass. Also I got Bergman wrong the first time. It sounds intrinsic to me; intrinsic but not fundamental, it is emergent.

With De Broglie, I'm putting it in both extrinsic camps solely from remembering that elementary particles don't self interact, but (and correct me if I'm wrong here) saying that elementary particles don't self interact is too wide of a brush stroke because CHARGED elementary particles clearly do. An electron is the same as any other electron for example and they are like charged and would repel. This ties in with the "there is only 1 electron in the universe  kind of thinking" but I'll expand on this later on when I get my facts straight about Wheeler Feynman absorber theory. If this works out, I'm putting any theory that relies on any charged particle and its associated field in both camps, because these fields also have a vacuum component that plays by same rules of interaction.

Intrinsic:
Higgs: Rest mass/energy contribute to inertial mass and rest mass because GR predicts they are equivalent.
Newton: It is intrinsic because I said so. It just is.
Bergman: Inertia is a real force arising from electrodynamics of moving particles. Force depends on velocity an acceleration.

Extrinsic Machian:
EM ZPF, Haisch et al
Unruh zpf/casimir McCulloch et al
De Broglie Compton resonance Haisch Reuda
Cosmic gravity-Mach
Cosmic gravity modified by Wheeler/Feynman, -Sciama-Woodward



Extrinsic local pertubation:
De Broglie Compton resonance Haisch Reuda

http://www.google.it/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0CC8QFjAC&url=http%3A%2F%2Fwww.commonsensescience.org%2Fpdf%2Farticles%2Finertial_mass.pdf&ei=GOAvVIPWJYSrPJnogIAG&usg=AFQjCNGT5DXFojND6Ft_jpIj4_wg-bhmIQ&bvm=bv.76802529,d.ZWU&cad=rja

http://www.calphysics.org/inertia.html
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 07:21 am
I'm just going to keep editing this post as a living document until I get my thoughts ironed out.

So my project today is to try and see if I can exclude Wheeler–Feynman absorber theory (which I'm not so completely critical of anymore, see very bottom) from being a logical component of Machian derived theories. I don't have the facts straight yet because I really don't have a firm understanding of the complex interactions of how T symmetry is broken in the electroweak realm, combined with the statements in my previous post. Basically what I'm grasping for is the point where T symmetry breaks and its relation to where mass arises (creating gravity) and to where charge arises.

Part of my problem is that I literally treat EVERYTHING as a wave, particle, and field at the same time. And for the quantum stuff I add a 2d probability distribution to that field in to visualize mass/energy (basically a 2d photo of a wave function) with a spike where the mass/energy is and in 3d as a simple random cloud where probability affects size/shape. When I'm taking charge into account, I take the 2d probability distribution I just mentioned and flip it 180 degrees so opposite charges cancel. Things make sense most of the time that way. (Maybe I need to change something about how I think.)

It is probably obvious to the whole world but me. It is keeping me up at night and I'm falling behind following up on other poster's comments and ideas that are pretty darn good too.

---(work in progress) So I can clearly picture how a photon and it's associated wave function can extend both forward and and back in time, now) In the context of the "infinite" universe, If I take an arbitrary particle/wave function and place it there across the cosmos, there is clearly no way to find a "present" in the context of spacetime. This works out for me with any photon because photons don't self interact and there is no rebound to worry about; no dissipative force or damping term is needed, but when I try to apply that to say an electron (which has charge) and it's associated field, it all falls apart for me. Charge really kills it for me.

When you accelerate an electron, it will give off EM radiation in the form of photons (which I just talked about above and get I it) with a wave function, the energy of that photon depends on the magnitude of acceleration and lasts for the duration of the acceleration as a response to the increase in momentum the electron has from being accelerated. Just conservation of energy, giving away energy in EM for a gain in kinetic energy.

Here's what this is all about:
---Does rest mass arise before, during/because or after T-symmetry is broken.

I clearly don't understand things.

Mass is what gives rise gravity. According to GR, inertial mass and rest mass are equivalent. (Not close, the same, fundamentally. is this assumption correct?) Theories which use Wheeler-Feynman to explain inertial mass, would require the use of fields which give rise to mass, but these particles self interact. Quarks very strongly interact with other quarks via gluons......Where am I going with this....lost it..break time.

brainstorming bs and work to do below
-Charge....
-Color charge......
-Justification for saying particles self interact....and why every other electron is equivalent
-What's really accelerating anyway (everything? if so that means absolute frame of reference is set by Hubble boundary condition, that would be convenient so first I'm accelerating wrt the universe, then/second, the stuff around me), given black body radiation, universe expansion, but QV doesn't get diluted as universe expands.....Points to consider that there are no absolute reference frames, It is a fact. Not trying to undo Einstein here but instead extrapolate all the details and implications of this... meaning there are no places in the universe which are completely not moving. Which celestial objects are accelerating vs which ones are NOT? And accelerating with respect to what? The center of our galaxy? Are the stars at the edge of our galaxy really undergoing very close to zero acceleration wrt the center of the galaxy? What accounts for the small acceleration that is left? The huge distance from the center of the galaxy? Meaning the curve of spacetime is very small, ie very small acceleration. Tentative conclusion, is there are no preferred reference frames=true, within galaxies. Between galaxies.....=true, the reference frame becomes the motion of all the other galaxies moving toward/away from you/who's to say you aren't accelerating toward them?=true. There are continuously collapsing layers of reference frames extending from the very large to the very small, each of which an observer can appear to be inertial, but it is an illusion and only true locally/not globally. Darn near everything is accelerating toward something else. So what?

-notes:
energy and momentum which are primary generators of gravity at high energies/accelerations, not mass
-massless: photons, gluons, gravitons
-massive: W and Z, quarks, electrons, muons, taus, some neutrinos, higgs

-w,z,quarks, leptons only get mass from the higgs.
-higgs gets mass from somewhere else...






Title: Re: EM Drive Developments
Post by: frobnicat on 10/05/2014 11:04 am
@frobnicat

What is the .01m² csection that you refer to?

Maybe you told us the definition of terms before but I didn't find them in the last 20 pages, yesterday.

I wonder, because that equals 100 cm^2 or a square about 4 inches on a side and I don't recognize that dimension wrt the thruster cavity.

This was a very crude order of magnitude number to start from. The tested devices are not 1m^3 volume nor 1cm^3, so I started at 1000cm^3, round (not flat) volume that is about 100cm^2 as seen from a passing flow. The real dimensions of devices are a bit above that : feel free to plug better numbers.

Obviously there would be a coupling factor  "harvested dark mass flow" = coupling * "incoming dark mass flow". I made the very very optimistic assumption that coupling = 1, which for notoriously shy particles is a bit of a stretch, to get an upper bound of thrust from naturally occurring dark matter. I guess there is a lot of unknown on such a coupling, but negative results from DM detection experiments indicate that it must be <<1. It would also depend on the particular details, depth of interacting volume... so this is a huge unknown between 0 and 1 but probably very near 0. If assumed as best case 1, my calculations show that, at best, this is still far from enough with 1GeV DM density and on the order of 100s km/s DM "wind".

For the later, answering my own question of "how hot is hot dark matter, could it be relativistic" I would say obviously not : DM particles speed can't be much above galactic escape velocity about 500km/s otherwise they would quickly evaporate from galaxy and not stick with it (as it appear from their gravity contribution).

So in the expression of DM mass flow, the flow velocity term can't be pushed much higher.

Title: Re: EM Drive Developments
Post by: frobnicat on 10/05/2014 11:44 am
To be clear...
using naturally occurring dark matter at 1Gev/cm^3 and a "round" 1000cm^3 device with near 100% DM harvesting capability :

- Sailing : we harvest particles at their incoming velocity (<600 km/s) and be pushed by them -> pico Newtons

- Propeller/slow wind : power of the device is used to accelerate DM particles. Incoming velocity is irrelevant (for energy) since Vej would be relativistic to get enough thrust from such a low mass flow. This is worthless to use DM slow mass then, since the ejected imparted kinetic energy >> energy equivalent of rest mass: better just make photons from your available power source and ignore DM entirely.

- Perfect mass to energy conversion + photon drive : we harvest particles at their incoming velocity (<600 km/s) and convert rest mass to energy (the 600km/s kinetic energy is irrelevant here compared to mc²) and use that power to push on photons (or any other light particle with relativistic ejection velocity) -> nano Newtons

1Gev/cm^3 is optimistic from what I understand. I'll look for the much higher upper bounds...
Note the stringent conditions for the later best case, underlined.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 12:18 pm
Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html
The NASA Eagleworks report shows that the resonant mode shape of operation is more important than the Q factor

<<B. Tapered Cavity RF Evaluation and Testing, First TM211 mode
Figures 18 and 19 chronicle the activities surrounding a series of five test runs at 1932.6 MHz corresponding to the first TM211 mode. In this test configuration, the VNA system indicated a quality factor of ~7320, and the difference of power forward and power reflected as reported by the power meters was indicated to be ~16.92 watts as a result of manual tuning to maximize the power difference. The (net) peak thrust observed for this tested configuration was 116 micronewtons and the (net) mean thrust over the five runs was 91.2 micronewtons.>>

<<C. Tapered Cavity RF Evaluation and Testing, Second TM211 mode
COMSOL® analysis indicates that there are two TM211 modes within a couple of MHz of one another for the as-built tapered thruster. The higher frequency TM211 mode has a much higher predicted quality factor (32,125), but considerably lower thrust to power performance (5 micronewtons per watt). The tapered RF system was tuned and operated at this mode for evaluation on the low thrust torsion pendulum. The measured quality factor was 18,100 with a power-forward/power-reflected difference of 16.74 watts and the average measured thrust was 50.1 micronewtons. With an input power of 16.74 watts, correcting for the quality factor, the predicted thrust was 47 micronewtons.>>

Unfortunately, the NASA report only shows the frequencies, but it does not show the mode shapes.  One cannot tell why a frequency of only  four MHz higher has a Q more than 4 times higher but a thrust force half as much as the lower frequency. It would be nice to have a picture of the mode actual mode shapes (as shown in the reference submitted by Mulletron http://www.gregegan.net/SCIENCE/Cavity/Cavity.html for a different geometry) to tell what is the difference in the mode shapes: what gets excited in the cavity at the 4 MHz lower mode shape that makes such a big difference.

Or is the thrust force (twice higher) at the 4 MHz lower frequency not really due to the mode shape but is it due to something happening in the dielectric resonator and/or coupling with something (dark matter for example)?

COMSOL® field plot for 1932.6 MHz, TM211 also shown for reference - red is electric, blue is magnetic
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 12:33 pm
Havn't been able to find the resonant formula I was looking for, but some interesting things in the old radar handbook.  The only point of interest for axion interaction in this setup is that surface effects can change the geometric cross-section from -12db to +28db in the optical region where wavelength is small compared to size.  The response of a bulk dielectric is noisy but only a few db around geometric area.

Edit: no real surprise about the proper mode being important.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 12:58 pm
Havn't been able to find the resonant formula I was looking for, but some interesting things in the old radar handbook.  The only point of interest for axion interaction in this setup is that surface effects can change the geometric cross-section from -12db to +28db in the optical region where wavelength is small compared to size.  The response of a bulk dielectric is noisy but only a few db around geometric area.

Edit: no real surprise about the proper mode being important.
If there is "no real surprise about the proper mode" shape being important, then we have to rethink the importance of the cavity.
@notsosureofit & @mulletron: any thoughts about the following ?:

Concerning the tapered cavity, maybe the geometry (not a perfect truncated cone, and notice the off center inner circle in the COMSOL vector plot I attached) is not that trivial: what could be the drastic difference in mode shapes with these two frequencies,  1932 and 1936 MHz that result in differences in thrust of a factor of 2 ?

COMSOL® field plot for 1932.6 MHz, TM211 also shown for reference - red is electric, blue is magnetic
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 01:05 pm
Modes determine the E,B field intensities at all the surfaces.  Yes you need to include the dielectric.  And if the dielectric interface is where any interaction takes place, that could explain the COMSOL model. (not that they mentioned the mode they used in the model)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 01:12 pm
Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html
The NASA Eagleworks report shows that the resonant mode of operation is more important than the Q factor

<<B. Tapered Cavity RF Evaluation and Testing, First TM211 mode
Figures 18 and 19 chronicle the activities surrounding a series of five test runs at 1932.6 MHz corresponding to the first TM211 mode. In this test configuration, the VNA system indicated a quality factor of ~7320, and the difference of power forward and power reflected as reported by the power meters was indicated to be ~16.92 watts as a result of manual tuning to maximize the power difference. The (net) peak thrust observed for this tested configuration was 116 micronewtons and the (net) mean thrust over the five runs was 91.2 micronewtons.>>

<<C. Tapered Cavity RF Evaluation and Testing, Second TM211 mode
COMSOL® analysis indicates that there are two TM211 modes within a couple of MHz of one another for the as-built tapered thruster. The higher frequency TM211 mode has a much higher predicted quality factor (32,125), but considerably lower thrust to power performance (5 micronewtons per watt). The tapered RF system was tuned and operated at this mode for evaluation on the low thrust torsion pendulum. The measured quality factor was 18,100 with a power-forward/power-reflected difference of 16.74 watts and the average measured thrust was 50.1 micronewtons. With an input power of 16.74 watts, correcting for the quality factor, the predicted thrust was 47 micronewtons.>>

Unfortunately, the NASA report only shows the frequencies, but it does not show the mode shapes.  One cannot tell why a frequency of only  a couple of MHz higher has a Q more than 4 times higher but a thrust force half as much as the lower frequency.  It would be nice to have a picture of the mode actual mode shapes (as shown in the reference submitted by Mulletron http://www.gregegan.net/SCIENCE/Cavity/Cavity.html for a different geometry) to tell what is the difference in the mode shapes: what gets excited in the cavity that makes such a big difference.

Or is the thrust force (twice higher) at the 2 MHz lower frequency not really due to the mode shape but is it due to something happening in the dielectric resonator and/or coupling with something (dark matter for example)?

COMSOL® field plot for 1932.6 MHz, TM211 also shown for reference - red is electric, blue is magnetic

I'm looking at pg 18 of the paper, with the results you posted, I remember when I picked the paper apart, my takeaway was that the TE012 mode was very efficient, with 2.6 watts in and 55uN peak and average thrust out. The Q factor didn't matter much. Comparing the TM211 mode, higher Q killed thrust. Why so few test runs anyway? Here's some stuff I wrote down on the Nasa report using info that I got from Navy Neets Module 11 and sources on the internet. So take TE012, or TExyz. X is the # of 1/2 wavelengths across a half circumference, y is the # of 1/2 wavelengths across a radius, Z is the poynting vector with the # of 1/2 wavelengths of length of the cavity. I forget of those modes are the big or small end or both if it is in proportion. You can calculate the size of the cavity using the info on page 18. Oh, it also clearly says it don't work without dielectric.

I tried making the same notes on a screenshot of the paper using paint but that failed. I'll take a pic or scan my annotated paper and post it when I get home.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 01:25 pm

http://www.theory.tifr.res.in/~hbar/PDF/ti.pdf

Thanks for this.  Starts making it more clear to me how the "dielectric" fits in to all this.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 01:26 pm

You know, before we blame [anyone] for bringing [another] theory here...

You totally miss the point, young Paduan.  There is no "blame" for bringing up various theories.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 01:26 pm
Propeller/slow wind : power of the device is used to accelerate DM particles.

I would like to read more about this approach.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 01:28 pm
For there to be 2 TM211 modes that close means the dielectric is splitting the mode.   I would guess the higher frequency is from the dielectric surface and the lower from the end wall (but including the dielectric) but the COMSOL diagram would appear to me to be of the higher frequency mode ?
Title: Re: EM Drive Developments
Post by: MP99 on 10/05/2014 01:30 pm


http://space.gotnewswire.com/news/particle-antiparticle-scientists-make-strange-discovery-capitalberg
Wow !

The Majorana fermion may have been finally found, after 77 years !

AIUI, I believe they've found something that operates on the same principles as the Majorana fermion, but it's a combination of an electron and a hole, not a particle and an antiparticle.

(I understood that the Cooper Pair in the classic explanation of low-temperature superconductivity is a combination of an electron plus a hole.)

Cheers, Martin
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 01:34 pm
For there to be 2 TM211 modes that close means the dielectric is splitting the mode.   I would guess the higher frequency is from the dielectric surface and the lower from the end wall (but including the dielectric) but the COMSOL diagram would appear to me to be of the higher frequency mode ?

The COMSOL plot is for the LOWER frequency mode (1932.6 MHz) (the mode that has the thrust force 2 times higher):

COMSOL® field plot for 1932.6 MHz, TM211 also shown for reference - red is electric, blue is magnetic
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 01:35 pm
Yes, thats how the topical insulator analogy works.  The difference in their experiment is that they have an axion "antenna" that they can monitor for the difference from the electron response.  (in theory anyway)

Edit:  meant Majorana not axion
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 01:43 pm
Figure 22 on page 18 worries me. That upward slope over 30 seconds while the rf was on and a slow fade after rf was off says heat was the cause. 70uN thrust/60uN heat.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 01:55 pm
Figure 22 on page 18 worries me. That upward slope over 30 seconds while the rf was on and a slow fade after rf was off says heat was the cause. 70uN thrust/60uN heat.

Bingo!

Yes, that's the coupling between the magnetic damping and the field from the power cable I have been writing about.  Notice that the coupling is HUGE.  By their own admission the "null" signal is 25% of the good signal !!!!!

And they subtract the coupling "null" signal as if the problem would be linear.  They do not take into account any nonlinearities.  There is no finite element (No COMSOL) analysis of the magnetic coupling problem

Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 01:59 pm
Having said that, my Mathematica analysis of the coupled nonlinear differential equations of the inverted pendulum is showing that the NASA Eagleworks results may be due to real thrust.  However without knowing the actual magnitude of the magnetic damping I am unclear at this point whether and how much is the distortion from the test and how much is real.

The big unknown I have is the magnitude of the magnetic damping.  Unfortunately Paul March has stopped communication some time ago. If he could provide the C value for the magnetic damping, it would be very helpful.  I would even perhaps be able to confirm that the NASA Eaglewoks results are real.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 02:03 pm
Figure 22 on page 18 worries me. That upward slope over 30 seconds while the rf was on and a slow fade after rf was off says heat was the cause. 70uN thrust/60uN heat.

Bingo!

Yes, that's the coupling between the magnetic damping and the field from the power cable I have been writing about.  Notice that the coupling is HUGE.  By their own admission the "null" signal is 25% of the good signal !!!!!

And they subtract the coupling "null" signal as if the problem would be linear.  They do not take into account any nonlinearities.  There is no finite element (No COMSOL) analysis of the magnetic coupling problem

Yeah all the modes show some heat or something else too.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 02:13 pm
Figure 22 on page 18 worries me. That upward slope over 30 seconds while the rf was on and a slow fade after rf was off says heat was the cause. 70uN thrust/60uN heat.

Bingo!

Yes, that's the coupling between the magnetic damping and the field from the power cable I have been writing about.  Notice that the coupling is HUGE.  By their own admission the "null" signal is 25% of the good signal !!!!!

And they subtract the coupling "null" signal as if the problem would be linear.  They do not take into account any nonlinearities.  There is no finite element (No COMSOL) analysis of the magnetic coupling problem

Yeah all the modes show some heat or something else too.

Yes, but it looks like there is something real exciting the system.  The only argument I see now for an artifact would be that the magnetic damping is interacting with the power cable AND the dielectric effect. Because they measure no thrust without the dielectric.  And because flipping the orientation of the dielectric flips the direction of the thrust.  So if it is an artifact one would have to explain it as a result of the magnetic fields (from the damping and the power cable) interacting with the dielectric.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 02:14 pm
Gravity is a how not a why.
Quote
Two points for Gryffindor on that one.

Still, isn't it a property of matter?  If it should be a property, then the question is, how does it work.  If not a property, then I don't know the question to ask.
If we knew how gravity really worked, we'd all have hovercars. I just want my darn hovercar and hoverboard already. We have 1 year left!

I marked up the Nasa paper with a line showing where to lop off the bell pillbox because it makes no difference.
Quote
Then what's the function of the "pillbox" after all?  It would seem that the very geometry of the apparatus is not conducive to maximizing the anomalous thrust.
I think both the cannae and tapered cavity were derived by inventors who had no idea how it worked, just that it worked. The pillbox and the slots are evidence of that. It doesn't matter how it works to crank out a cool gizmo that does neat stuff that makes people like us write 100 page forums. It takes knowing why to optimize it and make it take us to the stars. Unless we brute force it with high power/energy/superconductors and have it work but work like s#@t.

Maybe we'd be better off using sound instead of rf and use a sound room to create boundaries.
Quote
I'd like you to expand on that idea a little bit.  Sound is at least metaphysically fundamental on one level, and physically all around us on another.  Plus, it can be used to levitate or manipulate objects in certain environments.  One question I would ask, is, at what frequency does sound no longer exist?  Both high end and low end.
I picture sound just like any other particle/wave situation. It is much easier to work with too. Sound recently has been show to have particle behaviors. Phonons. Could there be a neat casimir effect too when in a sound proof room? Probably not, just thinking of impossible stuff.

Silly question and may sound of topic but I assure you it is relevant. Are causality and information conjugate variable pairs?
Quote
There is some kind of connection between information and causality. 

This is my intuition.  The obvious, extreme interpretation of that connection, from a pragmatic standpoint, should it be confirmed, would be teleportation.
I agree. Seriously, and AND logic gate is a transducer from information to heat. And no I don't mean like how a computer heats up, that happens too but that isn't where I'm going. That is the most exciting thing I have ever read. It is backed up by conservation of information in black holes too!

The internet isn't helping me much.

This problem is related to a whole other nother obsession I had since I learned about "A new kind of Science" where I was trying to make sense of information and computation giving rise to the universe.
Quote
Fixed that for ya.

The problem that I had with Wolfram's book is that he has to assume that there is a preexisting "matrix", and that there has to be sufficient time for his single celled spreadsheet (Or whatever it's called) to create a universe.  It's a Godelian problem, I'd say.  That was my takehome from the book.

As an aside, a related problem, in my mind, would be the apparent irreducible complexity of the DNA molecule.  One faction insists on the faith that random matter, immediately upon it's creation at the big bang, embarks on evolution, which can only and inevitably, in the one universe that we witness, results in DNA and intelligent life.  This, despite there being no possible mechanism nor sufficient time to so evolve from randomness.
Neat, wish I understood that. I really am very interested in genetics, but not the beauty of the double helix. I should be.

...why emdrive might have produced a small force really boils down the one fundamental problem, ... the problem being the origin of inertial mass.
Quote
What I bin sayin'.  Start with Sciama '53.
I've been trying to break Sciama all day and I'm not smart enough.

Quote
I'll keep an edit on this thing til we have it nailed down.

Thank you.  What I bin askin' for.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/05/2014 02:15 pm
At the radius of Earth's orbit: 1.4×10 −19 g/cm 3

that is 7.868x10^4 GeV/cm^3 = 78680 GeV/cm^3

....
At about 1Gev/cm^3 (as seen on this seemingly optimistic paper (http://inspirehep.net/record/878672/files/arXiv%3A1011.6323.pdf), maybe more optimistic is possible) and .01m² csection and 250km/s dark flow velocity that is mflow=1e9*1.8e-36 (http://fr.wikipedia.org/wiki/%C3%89lectron-volt)/1e-6 * 2.5e5 * 1e-2 = 4.5e-18 kg/s.
With about 45*µN thrusters that yields Vej = F / mflow = 4.5e-5 / 4.5e-18 = 1e12m/s   ???
Pow = .5 mflow Vej² = :D = .5 * 4.5e-18 * 1e24 = 2.25 e6 = 2.25MW hence the 6 orders of magnitude boast (more like 5 actually with those numbers) when comparing to 20W power.
...

So @frobnicat used  1Gev/cm^3  which is 78680 times less than this estimate !

That would make for the 4 order of magnitude in the best case (near 100% conversion of DM mass_energy flowing through the device to collimated relativistic light particles jet). Note that those quoted equations, which are for a different use of the dark flow (harvesting incoming mass and using onboard power to propel on it, no rest mass energy conversion, incoming mass used "as is")  are wrong since Newtonian and giving Vej > c. It should be properly handled in SR, but it does show that this other use (powered propeller in a medium) needs relativistic Vej, and that means that it puts much more energy on kinetic ejection velocity than it gains from recovering the incoming rest mass. Therefore it is sub-optimal when compared to the best case and not indicative for an upper bound.

Alright then, but remember the conditions : near 100% DM harvesting and DM rest mass -> energy -> collimated relativistic jet. That is, without involving exotica, as the whole point was to explain the results in a classical framework, even if using still experimentally elusive dark particles.

But from a short glance at the paper linked by Aero "Constraints on Dark Matter in the Solar System (http://arxiv.org/abs/1306.5534) where this number comes from : those are upper bounds of density as for the measurable gravity effects of DM in solar system's body orbits. While this is interesting as a very clear and strong limit, it implies that (if DM were to be actually found at such upper density limits) DM would stick around the massive bodies => flow speeds < sun escape velocity that's ~40km/s at earth distance (+ or - earth orbital velocity). So this has to be taken into account in the mass flow : take away almost an order of magnitude. So we are about 10000 above my less optimistic numbers when taking a galactic average DM density around there.

Quote
***there is also the question about the square cross section, previously posted by @aero ***

hope this was answered -> first very approximate geometric scale estimation

Quote
So now we are now much closer to the ballpark

Yes, seems just barely could make it, but at the cost of pushing everything at the higher conceivable upper bounds. In particular I don't see how any particular RF device could succeed at reaching a DM coupling factor near 1 while all the dedicated experiments to detect DM saw nothing or almost nothing ( my guesstimated bound : much less than 1 in 10^15 DM particles going through the experiments do interfere )

I think this pretty much discards "naturally occurring DM background in a classical framework" hypothesis as an explanation to even the lower thrust/power positive results.

Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 02:16 pm
For there to be 2 TM211 modes that close means the dielectric is splitting the mode.   I would guess the higher frequency is from the dielectric surface and the lower from the end wall (but including the dielectric) but the COMSOL diagram would appear to me to be of the higher frequency mode ?

The COMSOL plot is for the LOWER frequency mode (1932.6 MHz) (the mode that has the thrust force 2 times higher):

COMSOL® field plot for 1932.6 MHz, TM211 also shown for reference - red is electric, blue is magnetic

Sorry about that, I was thinking of Fig. 26, the next generation, where the field intensity is maximized at the dielectric surface. 


If the dielectric is a lot thicker in the tested cavity the intensity could maximize within the dielectric for the lower frequency mode.  I wish they would have shown more diagrams, I don't have access to COMSOL.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 02:22 pm
For there to be 2 TM211 modes that close means the dielectric is splitting the mode.   I would guess the higher frequency is from the dielectric surface and the lower from the end wall (but including the dielectric) but the COMSOL diagram would appear to me to be of the higher frequency mode ?

The COMSOL plot is for the LOWER frequency mode (1932.6 MHz) (the mode that has the thrust force 2 times higher):

COMSOL® field plot for 1932.6 MHz, TM211 also shown for reference - red is electric, blue is magnetic

Sorry about that, I was thinking of Fig. 26, the next generation, where the field intensity is maximized at the dielectric surface.

You mean this Electric Field plot from COMSOL


Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 02:24 pm
For there to be 2 TM211 modes that close means the dielectric is splitting the mode.   I would guess the higher frequency is from the dielectric surface and the lower from the end wall (but including the dielectric) but the COMSOL diagram would appear to me to be of the higher frequency mode ?

The COMSOL plot is for the LOWER frequency mode (1932.6 MHz) (the mode that has the thrust force 2 times higher):

COMSOL® field plot for 1932.6 MHz, TM211 also shown for reference - red is electric, blue is magnetic

Sorry about that, I was thinking of Fig. 26, the next generation, where the field intensity is maximized at the dielectric surface. 


If the dielectric is a lot thicker in the tested cavity the intensity could maximize within the dielectric for the lower frequency mode.  I wish they would have shown more diagrams, I don't have access to COMSOL.

<<If the dielectric is a lot thicker in the tested cavity the intensity could maximize within the dielectric for the lower frequency mode.  I wish they would have shown more diagrams, I don't have access to COMSOL.>>

I agree, excellent point
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 02:24 pm
Yes
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 02:29 pm
Having said that, my Mathematica analysis of the coupled nonlinear differential equations of the inverted pendulum is showing that the NASA Eagleworks results may be due to real thrust.

Why?  If ya don't mind? 

In plain French, Spanish, or Italian.  Your choice.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 02:30 pm
Gravity is a how not a why.

Two points for Gryffindor on that one....

Hey:  Did you just hit the "quote" button by accident?  'Cause there was not an actual response from you.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 02:33 pm
...
I think this pretty much discards "naturally occurring DM background in a classical framework" hypothesis as an explanation to even the lower thrust/power positive results.
Well, it gets pretty close, and it is standard physics as discussed at all major academic institutions.
And it does not violate local conservation of momentum.

So:

1) Calculation based on Unruth radiation got closest to Shawyer results.  Problem: it hasn't been tested for other results.  It depends highly on Q value and the "back of the envelope formula" does not include mode shape hence not able to deal well with NASA tapered cavity results for 4 MHz lower frequency with 4 times lower Q having 2 times higher thrust force

2) Calculations on dark matter get close based on most optimistic assumptions.

3) Coupling of magnetic damping with power cable and with dielectric may produce measured results.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/05/2014 02:37 pm
Yes, but it looks like there is something real exciting the system.  The only argument I see now for an artifact would be that the magnetic damping is interacting with the power cable AND the dielectric effect. Because they measure no thrust without the dielectric.  And because flipping the orientation of the dielectric flips the direction of the thrust.  So if it is an artifact one would have to explain it as a result of the magnetic fields (from the damping and the power cable) interacting with the dielectric.

I'm only loosely following all the dielectric theme...
Is it possible that in such a material there is some rectifier effect (forward/backward currents asymmetry) that converts a fraction of the RF AC current (0 net force in a constant B field) to DC current (not 0 net force in constant B field) ? That could explain why there is something more exciting the system when there is the dielectric and not without.

Assuming there is current at all... I understand there is current to bounce an EM wave off a conductive wall (the current is induced, conductivity insures E field is 0 at the boundary, ideal case) but what is going on at the boundary of dielectric resonator cavity ? Surely some charges are moving... any non symmetrical non linearities around 0 E field would be very suspect.

Also (too lazy to search) it was made mention to AC (Woodward ?) vs DC (White ?) : was it continuous microwave for the later (that is, not DC strictly speaking) and (amplitude ?) modulated microwave for the former ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 02:38 pm
Having said that, my Mathematica analysis of the coupled nonlinear differential equations of the inverted pendulum is showing that the NASA Eagleworks results may be due to real thrust.

Why?  If ya don't mind? 

In plain French, Spanish, or Italian.  Your choice.
Can't do better job at explaining with words analysis of coupled nonlinear differential equations with assumed parameters.  Will see if I have a better way to explain it.

For the time being: I need (hopefully from Paul March) actual damping value c (units: kg/s or N s/m) provided by magnetic damping , where damping force = c *(d x/ d t)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 02:38 pm
.....This problem is related to a whole other obsession I had since I learned about "A new kind of Science" where I was trying to make sense of information and computation giving rise to the universe. ...
Concerning Wolfram's "A new kind of science," do you use Wolfram's Mathematica ?  I use Mathematica a lot since version 1, was quite happy with version 9.  Disappointed with all the bugs in initial version 10.  They just came out with a patch for version 10, and I'm testing it now, while I continue to use my version 9 programs for my work.
I have never used Mathematica. In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides and I speak in terms of a layman and analyze things as a system and try to deduce patterns logically. I'm not a scientist and I don't do advanced math. I'm trying very hard to not be a crank but I want to be open minded. I see holes in theories which are evident by things like the emdrive. I'm not so full of hubris to just shitcan the whole idea of emdrives because it is taboo. I have no reputation as a famous scientist/professor to worry about. I really don't understand this stuff fully. I have always been a science geek since I was a little kid and science was my thing all through school enough to compete at a state level, but I don't do this at work. I'm trying to figure it out because I believe that while GR is correct, it is not complete until it is unified with QM and I believe the philosophy of science dominant now days, along with the unwillingness to continually test and push the limits of the sacred cows of science, is fundamentally holding us back. And I want a hovercar.

Title: Re: EM Drive Developments
Post by: frobnicat on 10/05/2014 02:54 pm
.../...
In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides ...
.../...

Sorry to skip the rest but, about that, do you know of any possible rectifier effect in dielectrics, that is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term ?

Quote
And I want a hovercar.

Yeah. So do I. But you know reality doesn't much care about making achievable all what we want ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 03:08 pm
.../...
In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides ...
.../...

Sorry to skip the rest but, about that, do you know of any possible rectifier effect in dielectrics, that is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term ?


@frobnicat,

Assume that such effect would exist for discussion purposes

A) what would explain flipping the direction (hence the sign) of the thrust force when flipping orientation

B) what would explain that a microwave frequency of 1932 MHz would have twice the measured thrust force as 1936 MHz, with the Q value being 1/4th as much as with the higher frequency?

Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 03:20 pm
Having said that, my Mathematica analysis of the coupled nonlinear differential equations of the inverted pendulum is showing that the NASA Eagleworks results may be due to real thrust.  However without knowing the actual magnitude of the magnetic damping I am unclear at this point whether and how much is the distortion from the test and how much is real.

The big unknown I have is the magnitude of the magnetic damping.  Unfortunately Paul March has stopped communication some time ago. If he could provide the C value for the magnetic damping, it would be very helpful.  I would even perhaps be able to confirm that the NASA Eaglewoks results are real.

That is serious top notch work you're doing.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/05/2014 03:20 pm
Propeller/slow wind : power of the device is used to accelerate DM particles.

I would like to read more about this approach.

Basically, pushing on a slow moving medium (relative to ship) is a good way to get high thrust/power ratio. In a dense medium, the ejection speed to get a given level of thrust (relative to the size of thruster) is low. For instance in air a propeller does a pretty decent thrust with ejection speeds around 100m/s (give or take). The higher the ejection speed, the higher the thrust but also lower efficiency. But still much better than photon rocket (ignoring medium and pushing on "pure energy" from the onboard generator).

Now with a very very scarce medium, the amount of mass/s that can be swallowed by the thruster is so weak that it takes very high ejection speeds to get a thrust level of any significance. When the scarcity of the medium implies relativistic ejection velocities to get interesting thrust, then the fact to use a medium mass at all becomes irrelevant because you put more energy as kinetic energy than the energy equivalence of harvested mass : if you have that much onboard energy to spend on kinetic energy of the jet, then just creating the rest mass (from energy) of what you are ejecting becomes a negligible term. You are almost as good with a photon rocket and ignoring the medium.

So that basically means that, given the scarcity of DM, it is worthless as a reaction mass. But it is better from its energy equivalent content. Harvesting this mass for its energy, and using this energy to power a photon drive, is the better achievable possible use of naturally occurring DM. This is not unlike a Bussard ramjet : treating the medium not as a passive reserve of mass to push on with onboard generator power, but converting a significant part of mass to energy and using this energy to power a fast jet.

And it falls short of explaining the results, unless you took all the most extremely favorable values together, sounds very unlikely to me. So the propeller/slow wind approach, being much worse, 3 orders of magnitude below, is clearly discarded.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 03:25 pm
Figure 22 on page 18 worries me. That upward slope over 30 seconds while the rf was on and a slow fade after rf was off says heat was the cause. 70uN thrust/60uN heat.

Bingo!

Yes, that's the coupling between the magnetic damping and the field from the power cable I have been writing about.  Notice that the coupling is HUGE.  By their own admission the "null" signal is 25% of the good signal !!!!!

And they subtract the coupling "null" signal as if the problem would be linear.  They do not take into account any nonlinearities.  There is no finite element (No COMSOL) analysis of the magnetic coupling problem

Yeah all the modes show some heat or something else too.

Yes, but it looks like there is something real exciting the system.  The only argument I see now for an artifact would be that the magnetic damping is interacting with the power cable AND the dielectric effect. Because they measure no thrust without the dielectric.  And because flipping the orientation of the dielectric flips the direction of the thrust.  So if it is an artifact one would have to explain it as a result of the magnetic fields (from the damping and the power cable) interacting with the dielectric.

Are you speaking precisely when you say flipping the orientation of the dielectric flips direction of thrust? I know they flipped the whole thing but this is different. If there is any chirality to PTFE, it makes a difference.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 03:29 pm
Figure 22 on page 18 worries me. That upward slope over 30 seconds while the rf was on and a slow fade after rf was off says heat was the cause. 70uN thrust/60uN heat.

Bingo!

Yes, that's the coupling between the magnetic damping and the field from the power cable I have been writing about.  Notice that the coupling is HUGE.  By their own admission the "null" signal is 25% of the good signal !!!!!

And they subtract the coupling "null" signal as if the problem would be linear.  They do not take into account any nonlinearities.  There is no finite element (No COMSOL) analysis of the magnetic coupling problem

Yeah all the modes show some heat or something else too.

Yes, but it looks like there is something real exciting the system.  The only argument I see now for an artifact would be that the magnetic damping is interacting with the power cable AND the dielectric effect. Because they measure no thrust without the dielectric.  And because flipping the orientation of the dielectric flips the direction of the thrust.  So if it is an artifact one would have to explain it as a result of the magnetic fields (from the damping and the power cable) interacting with the dielectric.

Are you speaking precisely when you say flipping the orientation of the dielectric flips direction of thrust? I know they flipped the whole thing but this is different. If there is any chirality to PTFE, it makes a difference.

Read "flipping [by 180 degrees around the vertical axis] orientation of the EM drive" flips the direction of the thrust (changing the sign of the thrust, just about same magnitue).
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 03:33 pm
So that basically means that, given the scarcity of DM, it is worthless as a reaction mass. But it is better from its energy equivalent content. Harvesting this mass for its energy, and using this energy to power a photon drive,..
But the photons need to escape the EM Drive to get propulsion.  How are the photons getting out of the drive? Do you see the downstream surface to be porous to photons traveling through it?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 03:55 pm
.../...
In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides ...
.../...

Sorry to skip the rest but, about that, do you know of any possible rectifier effect in dielectrics, that is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term ?

Quote
And I want a hovercar.

Yeah. So do I. But you know reality doesn't much care about making achievable all what we want ?


All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/05/2014 03:56 pm
So that basically means that, given the scarcity of DM, it is worthless as a reaction mass. But it is better from its energy equivalent content. Harvesting this mass for its energy, and using this energy to power a photon drive,..
But the photons need to escape the EM Drive to get propulsion.  How are the photons getting out of the drive? Do you see the downstream surface to be porous to photons traveling through it?
Well, for the argument, that could also be a neutrino jet, or any light particle with more kinetic energy than rest mass. The photon with a 0 rest mass is just a limit case. Also this is getting convoluted : have to take incoming DM <500km/s, and convert mass content to kinetic energy of collimated ejected relativistic particles that are light enough (otherwise they are less relativistic, and thrust is worse) and wall crossing (neutrinos, X rays). Mmm, you could even do the following : take incoming DM <500km/s, convert mass to energy, and with the energy of 1 million DM particles, accelerate 1 DM particle at relativistic speed.

Would be dark matter powered dark matter jet rocket. Call that a "dark matter ramjet". Unless anyone can point me to previous publication or grant, I hereby take precedence on that concept  8)

All those numbers above that could hypothetically reach the thrust levels of experiments assume the possibility of not only harvesting a huge ratio of DM but also of "burning" DM mass to release energy. Dark matter fusion now, is it advanced enough concept ?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 03:57 pm
But the photons need to escape the EM Drive to get propulsion.  How are the photons getting out of the drive? Do you see the downstream surface to be porous to photons traveling through it?

Earlier I had mentioned that no mass was being expelled.  I incorrectly mentioned electrons, and someone pointed out that photons were being produced, AIUI.

Still, nothing comes out of the other end.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 03:58 pm
.../...
In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides ...
.../...

Sorry to skip the rest but, about that, do you know of any possible rectifier effect in dielectrics, that is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term ?

Quote
And I want a hovercar.

Yeah. So do I. But you know reality doesn't much care about making achievable all what we want ?


All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.

Do  you agree "dielectric, is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term" ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 03:59 pm
But the photons need to escape the EM Drive to get propulsion.  How are the photons getting out of the drive? Do you see the downstream surface to be porous to photons traveling through it?

Earlier I had mentioned that no mass was being expelled.  I incorrectly mentioned electrons, and someone pointed out that photons were being produced, AIUI.

Still, nothing comes out of the other end.

Well, weakly interacting dark mass should be able to come out
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 04:00 pm
Propeller/slow wind : power of the device is used to accelerate DM particles.

I would like to read more about this approach.

Basically, pushing on a slow moving medium (relative to ship) is a good way to get high thrust/power ratio. In a dense medium, the ejection speed to get a given level of thrust (relative to the size of thruster) is low. For instance in air a propeller does a pretty decent thrust with ejection speeds around 100m/s (give or take). The higher the ejection speed, the higher the thrust but also lower efficiency. But still much better than photon rocket (ignoring medium and pushing on "pure energy" from the onboard generator).

Now with a very very scarce medium, the amount of mass/s that can be swallowed by the thruster is so weak that it takes very high ejection speeds to get a thrust level of any significance. When the scarcity of the medium implies relativistic ejection velocities to get interesting thrust, then the fact to use a medium mass at all becomes irrelevant because you put more energy as kinetic energy than the energy equivalence of harvested mass : if you have that much onboard energy to spend on kinetic energy of the jet, then just creating the rest mass (from energy) of what you are ejecting becomes a negligible term. You are almost as good with a photon rocket and ignoring the medium.

So that basically means that, given the scarcity of DM, it is worthless as a reaction mass. But it is better from its energy equivalent content. Harvesting this mass for its energy, and using this energy to power a photon drive, is the better achievable possible use of naturally occurring DM. This is not unlike a Bussard ramjet : treating the medium not as a passive reserve of mass to push on with onboard generator power, but converting a significant part of mass to energy and using this energy to power a fast jet.

And it falls short of explaining the results, unless you took all the most extremely favorable values together, sounds very unlikely to me. So the propeller/slow wind approach, being much worse, 3 orders of magnitude below, is clearly discarded.

You need something like a condensate to keep the density argument in the picture
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 04:01 pm
So that basically means that, given the scarcity of DM, it is worthless as a reaction mass. But it is better from its energy equivalent content. Harvesting this mass for its energy, and using this energy to power a photon drive,..
But the photons need to escape the EM Drive to get propulsion.  How are the photons getting out of the drive? Do you see the downstream surface to be porous to photons traveling through it?
Well, for the argument, that could also be a neutrino jet, or any light particle with more kinetic energy than rest mass. The photon with a 0 rest mass is just a limit case. Also this is getting convoluted : have to take incoming DM <500km/s, and convert mass content to kinetic energy of collimated ejected relativistic particles that are light enough (otherwise they are less relativistic, and thrust is worse) and wall crossing (neutrinos, X rays). Mmm, you could even do the following : take incoming DM <500km/s, convert mass to energy, and with the energy of 1 million DM particles, accelerate 1 DM particle at relativistic speed.

Would be dark matter powered dark matter jet rocket. Call that a "dark matter ramjet". Unless anyone can point me to previous publication or grant, I hereby take precedence on that concept  8)

All those numbers above that could hypothetically reach the thrust levels of experiments assume the possibility of not only harvesting a huge ratio of DM but also of "burning" DM mass to release energy. Dark matter fusion now, is it advanced enough concept ?

Seems lately I've been working against emdrive by trying to shut down theories all over the place. I think I can rule out dark matter by virtue that if it exists, it ONLY interacts gravitationally. RF and WIMPS don't play together. So it would take mass fluctuations, or gravity waves, or antigravity to work with DM.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 04:02 pm
Propeller/slow wind : power of the device is used to accelerate DM particles.

I would like to read more about this approach.

Basically, pushing on a slow moving medium (relative to ship) is a good way to get high thrust/power ratio. In a dense medium, the ejection speed to get a given level of thrust (relative to the size of thruster) is low. For instance in air a propeller does a pretty decent thrust with ejection speeds around 100m/s (give or take). The higher the ejection speed, the higher the thrust but also lower efficiency. ...

Thanks.

I was imagining a force field "propeller" about the diameter of the solar system, Pulling, say, a Dragon capsule.   That is, leveraging the rarity of the medium to get the thrust.

Too far out?

Allowing the capsule, diameter and power supply to exist for purposes of discussion.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 04:03 pm
.../...
In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides ...
.../...

Sorry to skip the rest but, about that, do you know of any possible rectifier effect in dielectrics, that is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term ?

Quote
And I want a hovercar.

Yeah. So do I. But you know reality doesn't much care about making achievable all what we want ?


All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.

Do  you agree "dielectric, is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term" ?

That concept doesn't compute.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 04:04 pm
.../...
In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides ...
.../...

Sorry to skip the rest but, about that, do you know of any possible rectifier effect in dielectrics, that is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term ?

Quote
And I want a hovercar.

Yeah. So do I. But you know reality doesn't much care about making achievable all what we want ?


All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.

Do  you agree "dielectric, is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term" ?

It's the same problem as axion detection in reverse.  You need the right combination of field, phase and photons.

Edit: Now that I think of it, it might be that pulling axions OUT of a condensate is what could give rise to a reaction force.  Got to think about that one.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 04:20 pm
.../...
In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides ...
.../...

Sorry to skip the rest but, about that, do you know of any possible rectifier effect in dielectrics, that is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term ?

Quote
And I want a hovercar.

Yeah. So do I. But you know reality doesn't much care about making achievable all what we want ?


All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.

Do  you agree "dielectric, is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term" ?

It's the same problem as axion detection in reverse.  You need the right combination of field, phase and photons.

Ok you can use a RC network as a filter (which is done after you go through a half or full wave rectifier normally) to filter out all but the "tops" of the ac sine wave. You would end up with a dc with a LOT of ripple.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 04:21 pm
.../...
In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides ...
.../...

Sorry to skip the rest but, about that, do you know of any possible rectifier effect in dielectrics, that is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term ?

Quote
And I want a hovercar.

Yeah. So do I. But you know reality doesn't much care about making achievable all what we want ?


All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.

Do  you agree "dielectric, is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term" ?

It's the same problem as axion detection in reverse.  You need the right combination of field, phase and photons.

Ok you can use a RC network as a filter (which is done after you go through a half or full wave rectifier normally) to filter out all but the "tops" of the ac sine wave. You would end up with a dc with a LOT of ripple.
There is a fair amount of "ripple" in the measured response
Title: Re: EM Drive Developments
Post by: frobnicat on 10/05/2014 04:26 pm

Assume that such effect would exist for discussion purposes

A) what would explain flipping the direction (hence the sign) of the thrust force when flipping orientation

B) what would explain that a microwave frequency of 1932 MHz would have twice the measured thrust force as 1936 MHz, with the Q value being 1/4th as much as with the higher frequency?

Would rather first try to know if it is possible, at what magnitudes, then where and how.
I'm not sure I'm understanding well the design but (anomalous thrust...) the dielectrics are encased in a conductive tube, no ? Don't know if there is some small space or not between dielectric and those walls, don't know if it would make any difference. Surely <<wavelength but near field effects ? Anyhow, if any rectifier effect is present in such a situation as to be the cause of a net thrust in a given thruster's orientation (say, a small DC current loop component somewhere) then reversing the orientation could reverse said thrust (relative to a vertical permanent B component). Details (where, how) must be addressed, but I don't know enough to tackle that more than qualitatively.
B) would imply a square root dependence on Q ? Wouldn't 4 times a Q imply linearly 4 times E and B fields and hypothetically 4 times DC current loops, that is 4 times forces ? Needs to know how non linear would be such rectifier effects (if possible at all).

@Mulletron : what I was asking for was not for a known way to do a proper efficient AC->DC conversion, but rather for an "imperfection" of dielectrics known to generate a small (usually unwanted) DC component. This would be a deviation from the ideal linear behaviour. Non linearity would not be enough, it would require non linearity around 0 E field (that is, non forward/backward symmetrical). It would likely be filed under "unwanted distortions" or "deviations from the ideal" for instance in RF signal processing literature (that I'm not familiar with). Maybe it doesn't exist, or if it exists it is marginal and never or not often mentioned...

Now, come on people, the time I write that there is SEVEN new posts ! And a new one while just writing this very sentence ! Sheesh !
Must do some other business, see you later.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 04:29 pm
.../...
In my job I mostly deal with electronic engineering. I know a lot about radars, communications (satellite mostly), and navigation equipment like gyros. Hence why I have a clue about waveguides ...
.../...

Sorry to skip the rest but, about that, do you know of any possible rectifier effect in dielectrics, that is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term ?

Quote
And I want a hovercar.

Yeah. So do I. But you know reality doesn't much care about making achievable all what we want ?


All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.

Do  you agree "dielectric, is acting like a fast switching diode to convert (a fraction of) AC RF energy to a significant DC current term" ?

It's the same problem as axion detection in reverse.  You need the right combination of field, phase and photons.

Ok you can use a RC network as a filter (which is done after you go through a half or full wave rectifier normally) to filter out all but the "tops" of the ac sine wave. You would end up with a dc with a LOT of ripple.
There is a fair amount of "ripple" in the measured response

Well here's a math problem for you and that's your strength. You know the frequency, you have a graph of the response with ripples intact and a time reference on the graph, the sloppy rectifier I explained to you is a 1/2 wave rectifier. You can figure out every aspect of this thing by knowing frequency and time which are in the paper. I think the ripples are noise. There is the same noise ripple when the device is off.

Changed that to half wave.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 04:34 pm
Well here's a math problem for you and that's your strength. You know the frequency 1, you have a graph of the response with ripples intact and a time reference on the graph, the sloppy rectifier I explained to you is a 1/4 wave rectifier. You can figure out every aspect of this thing by knowing frequency and time which are in the paper. I think the ripples are noise. There is the same noise ripple when the device is off.

I think that the ripples are the dynamic response (due to the mechanical degrees of freedom and their derivatives) of the inverted torsional pendulum which is not completely damped out.  I need to have actual damping value supplied by magnetic damping but that's what my model shows.  Observe that highest intensity of ripple is actually in response to the application of the "on" impulse (and it decays thereafter) and to the "off" impulse (and it decays thereafter).  Clearly dynamics of the pendulum to me.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 04:38 pm
Well here's a math problem for you and that's your strength. You know the frequency 1, you have a graph of the response with ripples intact and a time reference on the graph, the sloppy rectifier I explained to you is a 1/4 wave rectifier. You can figure out every aspect of this thing by knowing frequency and time which are in the paper. I think the ripples are noise. There is the same noise ripple when the device is off.

I think that the ripples are the dynamic response (due to the mechanical degrees of freedom and their derivatives) of the inverted torsional pendulum which is not completely damped out.  I need to have actual damping value supplied by magnetic damping but that's what my model shows.  Observe that highest intensity of ripple is actually in response to the application of the "on" impulse (and it decays thereafter) and to the "off" impulse (and it decays thereafter).  Clearly dynamics of the pendulum to me.

Well before and after each rf on event they did a cal pulse. Also if there wasn't a feedback loop to the damper, the unit would surge and dip upon first rf on.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/05/2014 04:39 pm
Ok you can use a RC network as a filter (which is done after you go through a half or full wave rectifier normally) to filter out all but the "tops" of the ac sine wave. You would end up with a dc with a LOT of ripple.
There is a fair amount of "ripple" in the measured response

Ok, last one :
my assumption is a small part of RF AC is rectified somewhere, this would be an unwanted effect, no fancy filtering, but the ripples are at RF also, so if a current loop (in the permanent B field) has a DC component + RF ripples, it transfers a force with the same time signature but the varying component is filtered by the mechanical inertia which has time constants many orders of magnitude higher than the variability : so in effect the balance measures only the DC component.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 04:44 pm
Since @frobnicat is taking a break to "have a life" and reduce his cholesterol  :)   , I think this is an appropriate moment to recapitulate:


1) Calculation based on Unruth radiation got closest to Shawyer results.  Problem: it hasn't been tested for other experimental results.  It depends highly on Q value and the "back of the envelope formula" does not include mode shape hence not able to deal well [at this point] with NASA tapered cavity results for 4 MHz lower frequency with 4 times lower Q having 2 times higher thrust force

2) Calculations on dark matter can get close based on extremely optimistic assumptions.  Average assumptions put it orders of magnitude off.

3) Coupling of magnetic damping with power cable and with dielectric has not been analyzed at this point where we have numbers: so it is not in the same level of analysis as the the other two above.

~~~~~~~~~~~~~~~~
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 04:59 pm
Ok you can use a RC network as a filter (which is done after you go through a half or full wave rectifier normally) to filter out all but the "tops" of the ac sine wave. You would end up with a dc with a LOT of ripple.
There is a fair amount of "ripple" in the measured response

Ok, last one :
my assumption is a small part of RF AC is rectified somewhere, this would be an unwanted effect, no fancy filtering, but the ripples are at RF also, so if a current loop (in the permanent B field) has a DC component + RF ripples, it transfers a force with the same time signature but the varying component is filtered by the mechanical inertia which has time constants many orders of magnitude higher than the variability : so in effect the balance measures only the DC component.

As I mentioned, you can do a sloppy rectifier by using a filter. Dielectrics are by definition inductive and capacitive. I mentioned RC networks, but maybe LC or RLC network would have been a better choice to put out there because those take advantage of the properties of the dielectric.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 05:04 pm
Since @frobnicat is taking a break to "have a life" and reduce his cholesterol  :)   , I think this is an appropriate moment to recapitulate:


1) Calculation based on Unruth radiation got closest to Shawyer results.  Problem: it hasn't been tested for other experimental results.  It depends highly on Q value and the "back of the envelope formula" does not include mode shape hence not able to deal well [at this point] with NASA tapered cavity results for 4 MHz lower frequency with 4 times lower Q having 2 times higher thrust force

2) Calculations on dark matter can get close based on extremely optimistic assumptions.  Average assumptions put it orders of magnitude off.

3) Coupling of magnetic damping with power cable and with dielectric has not been analyzed at this point where we have numbers: so it is not in the same level of analysis as the the other two above.

~~~~~~~~~~~~~~~~

So I introduce another classical physics explanation, not yet investigated (forgive me if my memory is incorrect):

4) Thermal radiation pressure.  For several years the Pioneer anomaly http://en.wikipedia.org/wiki/Pioneer_anomaly remained unexplained.  Very exotic physics explanations were offered from different camps.  Including the Unruth radiation explanation.  Bottom line: a finite element analysis from JPL (http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.107.081103   ) conclusively showed that it was due to Thermal Radiation Pressure. Although we eliminated thermal expansion, shifting of Center of Mass as an explanation, we have not examined thermal radiation pressure.  The problem with thermal expansion is that the transient heat response is related to the heat capacity and density of the Teflon, which results in too slow a response (compared to measurements).

Thermal radiation pressure would  be related to mode shape, as it is thermal radiation from the walls, and specifically their asymmetry that would be responsible for thrust effect.

I can rule out thermal radiation pressure right now by virtue that heating and cooling are not instantaneous. We did see thermal effects, what I mentioned before about the rising slope over 30 seconds with rf on, then a dropping slope over 30 seconds with rf off.

I think we need to combine the forum's conclusions in a living document. Even though science is not democratic, I don't want to keep beating dead horses that have been decided on as fact (not to say any of my ideas are generally accepted or anything). Do you agree? If so, we could implement it using this forum or a shared google doc.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 05:05 pm
Ok you can use a RC network as a filter (which is done after you go through a half or full wave rectifier normally) to filter out all but the "tops" of the ac sine wave. You would end up with a dc with a LOT of ripple.
There is a fair amount of "ripple" in the measured response

Ok, last one :
my assumption is a small part of RF AC is rectified somewhere, this would be an unwanted effect, no fancy filtering, but the ripples are at RF also, so if a current loop (in the permanent B field) has a DC component + RF ripples, it transfers a force with the same time signature but the varying component is filtered by the mechanical inertia which has time constants many orders of magnitude higher than the variability : so in effect the balance measures only the DC component.

As I mentioned, you can do a sloppy rectifier by using a filter. Dielectrics are by definition inductive and capacitive. I mentioned RC networks, but maybe LC or RLC network would have been a better choice to put out there because those take advantage of the properties of the dielectric.

Can the dielectric together with the rest of the system result in a van der Pool oscillation http://en.wikipedia.org/wiki/Van_der_Pol_oscillator  like in a triode ?

Such a circuit produces relaxation oscillations. For a given set of properties the relaxation response looks almost like a rectangular wave
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 05:05 pm
I really want some feedback concerning my comments trying to shut down dark matter. Good science is trying to break things.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 05:08 pm
...

I can rule out thermal radiation pressure right now by virtue that heating and cooling are not instantaneous. We did see thermal effects, what I mentioned before about the rising slope over 30 seconds with rf on, then a dropping slope over 30 seconds with rf off.

I think we need to combine the forum's conclusions in a living document. Even though science is not democratic, I don't want to keep beating dead horses that have been decided on as fact (not to say any of my ideas are generally accepted or anything). Do you agree? If so, we could implement it using this forum or a shared google doc.

I completely agree on the living document and I support implementing it on this forum
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 05:19 pm

Assume that such effect would exist for discussion purposes

A) what would explain flipping the direction (hence the sign) of the thrust force when flipping orientation

B) what would explain that a microwave frequency of 1932 MHz would have twice the measured thrust force as 1936 MHz, with the Q value being 1/4th as much as with the higher frequency?

Would rather first try to know if it is possible, at what magnitudes, then where and how.
I'm not sure I'm understanding well the design but (anomalous thrust...) the dielectrics are encased in a conductive tube, no ? Don't know if there is some small space or not between dielectric and those walls, don't know if it would make any difference. Surely <<wavelength but near field effects ? Anyhow, if any rectifier effect is present in such a situation as to be the cause of a net thrust in a given thruster's orientation (say, a small DC current loop component somewhere) then reversing the orientation could reverse said thrust (relative to a vertical permanent B component). Details (where, how) must be addressed, but I don't know enough to tackle that more than qualitatively.
B) would imply a square root dependence on Q ? Wouldn't 4 times a Q imply linearly 4 times E and B fields and hypothetically 4 times DC current loops, that is 4 times forces ? Needs to know how non linear would be such rectifier effects (if possible at all).

@Mulletron : what I was asking for was not for a known way to do a proper efficient AC->DC conversion, but rather for an "imperfection" of dielectrics known to generate a small (usually unwanted) DC component. This would be a deviation from the ideal linear behaviour. Non linearity would not be enough, it would require non linearity around 0 E field (that is, non forward/backward symmetrical). It would likely be filed under "unwanted distortions" or "deviations from the ideal" for instance in RF signal processing literature (that I'm not familiar with). Maybe it doesn't exist, or if it exists it is marginal and never or not often mentioned...

Now, come on people, the time I write that there is SEVEN new posts ! And a new one while just writing this very sentence ! Sheesh !
Must do some other business, see you later.

Never heard of something like that. A dielectric is open to DC. Dc current doesn't flow through capacitors. It is used to actively isolate DC from other things in circuits. As soon as the cap is charged up and fully polarized, no more current flow. Where is this leading?
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 05:26 pm
...

I can rule out thermal radiation pressure right now by virtue that heating and cooling are not instantaneous. ..

I agree. I just did  a quick calculation.   I edited the record accordingly.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 05:29 pm
I really want some feedback concerning my comments trying to shut down dark matter. Good science is trying to break things.

Agreed, but good science also takes time to enable thoughtful responses. Just like thermal effects  :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 05:34 pm
Ok you can use a RC network as a filter (which is done after you go through a half or full wave rectifier normally) to filter out all but the "tops" of the ac sine wave. You would end up with a dc with a LOT of ripple.
There is a fair amount of "ripple" in the measured response

Ok, last one :
my assumption is a small part of RF AC is rectified somewhere, this would be an unwanted effect, no fancy filtering, but the ripples are at RF also, so if a current loop (in the permanent B field) has a DC component + RF ripples, it transfers a force with the same time signature but the varying component is filtered by the mechanical inertia which has time constants many orders of magnitude higher than the variability : so in effect the balance measures only the DC component.

As I mentioned, you can do a sloppy rectifier by using a filter. Dielectrics are by definition inductive and capacitive. I mentioned RC networks, but maybe LC or RLC network would have been a better choice to put out there because those take advantage of the properties of the dielectric.

Can the dielectric together with the rest of the system result in a van der Pool oscillation http://en.wikipedia.org/wiki/Van_der_Pol_oscillator  like in a triode ?

Such a circuit produces relaxation oscillations. For a given set of properties the relaxation response looks almost like a rectangular wave

To make electrical circuits like a van der Pool oscillator, active circuit elements with a cubic (or quintic, etc.) nonlinear property, i=ϕ(v)=γv^3−αv , are required, where i and v are current and voltage, respectively.  van der Pol built the oscillator using the triode or tetrode.  Also with a tunnel diode ( http://en.wikipedia.org/wiki/Tunnel_diode ) instead of the triode, the van der Pol oscillator can take place as well.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 05:39 pm
Ok you can use a RC network as a filter (which is done after you go through a half or full wave rectifier normally) to filter out all but the "tops" of the ac sine wave. You would end up with a dc with a LOT of ripple.
There is a fair amount of "ripple" in the measured response

Ok, last one :
my assumption is a small part of RF AC is rectified somewhere, this would be an unwanted effect, no fancy filtering, but the ripples are at RF also, so if a current loop (in the permanent B field) has a DC component + RF ripples, it transfers a force with the same time signature but the varying component is filtered by the mechanical inertia which has time constants many orders of magnitude higher than the variability : so in effect the balance measures only the DC component.

As I mentioned, you can do a sloppy rectifier by using a filter. Dielectrics are by definition inductive and capacitive. I mentioned RC networks, but maybe LC or RLC network would have been a better choice to put out there because those take advantage of the properties of the dielectric.

Can the dielectric together with the rest of the system result in a van der Pool oscillation http://en.wikipedia.org/wiki/Van_der_Pol_oscillator  like in a triode ?

Such a circuit produces relaxation oscillations. For a given set of properties the relaxation response looks almost like a rectangular wave

http://scholarpedia.org/article/Van_der_Pol_oscillator
You have to engineer a circuit like this. I can't imagine how it would happen by accident.

"To make electrical circuits described by equation (1), active circuit elements with the cubic nonlinear property, i=ϕ(v)=γv3−αv , are required, where i and v are current and voltage, respectively. "

These things sound cool, why don't I see these in pseudorandom number generators? I just realized we brought chaos theory to the table, sheesh.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 05:46 pm
Ok you can use a RC network as a filter (which is done after you go through a half or full wave rectifier normally) to filter out all but the "tops" of the ac sine wave. You would end up with a dc with a LOT of ripple.
There is a fair amount of "ripple" in the measured response

Ok, last one :
my assumption is a small part of RF AC is rectified somewhere, this would be an unwanted effect, no fancy filtering, but the ripples are at RF also, so if a current loop (in the permanent B field) has a DC component + RF ripples, it transfers a force with the same time signature but the varying component is filtered by the mechanical inertia which has time constants many orders of magnitude higher than the variability : so in effect the balance measures only the DC component.

As I mentioned, you can do a sloppy rectifier by using a filter. Dielectrics are by definition inductive and capacitive. I mentioned RC networks, but maybe LC or RLC network would have been a better choice to put out there because those take advantage of the properties of the dielectric.

Can the dielectric together with the rest of the system result in a van der Pool oscillation http://en.wikipedia.org/wiki/Van_der_Pol_oscillator  like in a triode ?

Such a circuit produces relaxation oscillations. For a given set of properties the relaxation response looks almost like a rectangular wave

http://scholarpedia.org/article/Van_der_Pol_oscillator
You have to engineer a circuit like this. I can't imagine how it would happen by accident.

"To make electrical circuits described by equation (1), active circuit elements with the cubic nonlinear property, i=ϕ(v)=γv3−αv , are required, where i and v are current and voltage, respectively. "

These things sound cool, why don't I see these in pseudorandom number generators? I just realized we brought chaos theory to the table, sheesh.

The van der Pool circuit with a a tunnel diode ( http://en.wikipedia.org/wiki/Tunnel_diode ) does not look too complicated.  Can the Teflon dielectric act as a tunnel diode ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 05:48 pm
The more far fetched we get here, creating more and more complex explanations, probably won't help us. Seems the most simple explanations are more likely correct. Occam's razor and all. I'm ready to start shutting down theories. I also intend to make my critical analysis of the paper more known in detail as soon as I can.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 05:50 pm
...

I can rule out thermal radiation pressure right now by virtue that heating and cooling are not instantaneous. ..

I agree. I just did  a quick calculation.   I edited the record accordingly.

Where is the record/living document? How did you do it so everyone can share?
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 05:50 pm
The more far fetched we get here, creating more and more complex explanations, probably won't help us. Seems the most simple explanations are more likely correct. Occam's razor and all. I'm ready to start shutting down theories. I also intend to make my critical analysis of the paper more known in detail as soon as I can.
And the simplest coherent explanations, per your understanding are ...?
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 05:52 pm
...

I can rule out thermal radiation pressure right now by virtue that heating and cooling are not instantaneous. ..

I agree. I just did  a quick calculation.   I edited the record accordingly.

Where is the record/living document? How did you do it so everyone can share?
The calculation?  Well I did a calculation based on Teflon about 70+ pages back.  I just substituted the copper properties now and replaced the (COMSOL calculated) EF in the Teflon with the EF in the copper.  I didn't post the calculations but they are very similar.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 05:58 pm
The more far fetched we get here, creating more and more complex explanations, probably won't help us. Seems the most simple explanations are more likely correct. Occam's razor and all. I'm ready to start shutting down theories. I also intend to make my critical analysis of the paper more known in detail as soon as I can.
And the simplest coherent explanations, per your understanding are ...?

In order from simple to not simple top 6:
1. It doesn't work
2. The generally accepted ideas for inertial mass are correct and it still works but by some other way, like heat and isn't useful.
2.5 Same as above but is useful.
3. Inertial mass works some other way; Unruh zpf/casimir McCulloch et al
4. Inertial mass works some other way; De Brogie Compton resonance Haisch Reuda
5. Inertial mass works some other way; EM ZPF, Haisch et al

The reason I'm trying first to get rid of Wheeler-Feynman absorber is because while I think his theory is correct, it isn't applicable to emdrive. I should probably promote it higher up the list because actual scientists think it is salient, but it is my choice.


I edited this >9000 times.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 06:07 pm
The more far fetched we get here, creating more and more complex explanations, probably won't help us. Seems the most simple explanations are more likely correct. Occam's razor and all. I'm ready to start shutting down theories. I also intend to make my critical analysis of the paper more known in detail as soon as I can.
And the simplest coherent explanations, per your understanding are ...?

In order from simple to not simple top 6:
1. It doesn't work
2. The generally accepted ideas for inertial mass are correct and it still works but by some other way, like heat and isn't useful.
2.5 Same as above but is useful.
3. Inertial mass works some other way; Unruh zpf/casimir McCulloch et al
4. Inertial mass works some other way; De Brogie Compton resonance Haisch Reuda
5. Inertial mass works some other way; EM ZPF, Haisch et al

I edited this >9000 times.
Mmmm simplest explanations for the measurements for NASA Eagleworks  :), let's see

1, 2.5 do not explain the measurements
2 I thought you had ruled out heat (too slow)
3 Unruth zpf/casimir McCulloch (no zpf needs to be involved, that's just an interpretation) rises to the top but has the "Q" problem I discussed
4 I don't recall we discussing that one (De Brogie Compton resonance Haisch Reuda )
5 No way that (EM ZPF, Haisch) this is more likely than dark mass  :)

4 and 5 are not simple explanations and they have lots of problems
Need more editing and review  :) agreed ?

And what happened with interaction between magnetic damping / power cable and dielectric ? Is that really more unlikely than Haisch ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 06:21 pm
The more far fetched we get here, creating more and more complex explanations, probably won't help us. Seems the most simple explanations are more likely correct. Occam's razor and all. I'm ready to start shutting down theories. I also intend to make my critical analysis of the paper more known in detail as soon as I can.
And the simplest coherent explanations, per your understanding are ...?

In order from simple to not simple top 6:
1. It doesn't work
2. The generally accepted ideas for inertial mass are correct and it still works but by some other way, like heat and isn't useful.
2.5 Same as above but is useful.
3. Inertial mass works some other way; Unruh zpf/casimir McCulloch et al
4. Inertial mass works some other way; De Brogie Compton resonance Haisch Reuda
5. Inertial mass works some other way; EM ZPF, Haisch et al

I edited this >9000 times.
Mmmm simplest explanations for the measurements for NASA Eagleworks  :), let's see

1, 2.5 do not explain the measurements
2 I thought you had ruled out heat (too slow)
3 Unruth zpf/casimir McCulloch (no zpf needs to be involved, that's just an interpretation) rises to the top but has the "Q" problem I discussed
4 I don't recall we discussing that one (De Brogie Compton resonance Haisch Reuda )
5 No way that (EM ZPF, Haisch) this is more likely than dark mass  :)

4 and 5 are not simple explanations and they have lots of problems
Need more editing and review  :) agreed ?

And what happened with interaction between magnetic damping / power cable and dielectric ? Is that really more unlikely than Haisch ?

In order from simple/likely to not simple/unlikely top 6:
1. It doesn't work, they got it wrong by some means I don't know and neither do they.
2. The generally accepted ideas for inertial mass are correct and it still works but by some other way, and isn't useful.
2.5 Same as above but is useful.
3. Inertial mass works some other way; Unruh, zpf/casimir McCulloch et al
4. Inertial mass works some other way; De Broglie Compton resonance Haisch Reuda
5. Inertial mass works some other way; EM ZPF, Haisch et al

Ok I conceded some by the modifications I made. Removed heat, put x in its spot. Unruh has a , after it. 4 and 5 remain. I blew dark matter out of the water. Awaiting comments on that one.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 06:28 pm

In order from simple/likely to not simple/unlikely top 6:
1. It doesn't work, they got it wrong by some means I don't know and neither do they.
2. The generally accepted ideas for inertial mass are correct and it still works but by some other way, and isn't useful.
2.5 Same as above but is useful.
3. Inertial mass works some other way; Unruh, zpf/casimir McCulloch et al
4. Inertial mass works some other way; De Broglie Compton resonance Haisch Reuda
5. Inertial mass works some other way; EM ZPF, Haisch et al

Ok I conceded some by the modifications I made. Removed heat, put x in its spot. Unruh has a , after it. 4 and 5 remain. I blew dark matter out of the water. Awaiting comments on that one.
Well rather than me dismissing Haisch on arguments with words, how about if we get to numbers   :). Can quantitative predictions be made based on (Compton resonance Haisch Reuda) ?
Title: Re: EM Drive Developments
Post by: aero on 10/05/2014 06:36 pm
I really want some feedback concerning my comments trying to shut down dark matter. Good science is trying to break things.

I'm not sure its time to shut down dark matter as a possibility. Attached is another estimate of dark matter in the solar system, from

 http://www.universetoday.com/15266/dark-matter-is-denser-in-the-solar-system/ (http://www.universetoday.com/15266/dark-matter-is-denser-in-the-solar-system/)

It is not quite as high as the upper limits given earlier, but quite close: 2.99E-17 kg/m^3 verses 1.40E-16 kg/m^3 . That is about a factor of 5 lower.

My point is that we don't know enough about dark matter to rule it out yet. All of these estimates are for dark matter in space but we know that dark matter is gravitationally attracted to mass (read "Earth") so can we say with any confidence what the dark matter density is at the surface of the Earth where the gravitational field is much stronger?

Further, the small end of the cavity is about .022 m^3, but the large end is about 0.05 m^2. There was the mention of an effect akin to antenna gain earlier. That has not been considered.

It seems to me that in order for the effect to be due to dark matter, and allowing for some conceptual inefficiencies,  there needs to be about 3 orders of magnitude more dark matter accelerated by the thruster than has so far been estimated.

JMO, but we don't know enough to rule out dark matter at this point.

Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 06:36 pm

In order from simple/likely to not simple/unlikely top 6:
1. It doesn't work, they got it wrong by some means I don't know and neither do they.
2. The generally accepted ideas for inertial mass are correct and it still works but by some other way, and isn't useful.
2.5 Same as above but is useful.
3. Inertial mass works some other way; Unruh, zpf/casimir McCulloch et al
4. Inertial mass works some other way; De Broglie Compton resonance Haisch Reuda
5. Inertial mass works some other way; EM ZPF, Haisch et al

Ok I conceded some by the modifications I made. Removed heat, put x in its spot. Unruh has a , after it. 4 and 5 remain. I blew dark matter out of the water. Awaiting comments on that one.
Well rather than me dismissing Haisch on arguments with words, how about if we get to numbers   :). Can quantitative predictions be made based on (Compton resonance Haisch Reuda) ?

Yes

http://xxx.lanl.gov/pdf/gr-qc/9906084v3.pdf
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 06:40 pm

In order from simple/likely to not simple/unlikely top 6:
1. It doesn't work, they got it wrong by some means I don't know and neither do they.
2. The generally accepted ideas for inertial mass are correct and it still works but by some other way, and isn't useful.
2.5 Same as above but is useful.
3. Inertial mass works some other way; Unruh, zpf/casimir McCulloch et al
4. Inertial mass works some other way; De Broglie Compton resonance Haisch Reuda
5. Inertial mass works some other way; EM ZPF, Haisch et al

Ok I conceded some by the modifications I made. Removed heat, put x in its spot. Unruh has a , after it. 4 and 5 remain. I blew dark matter out of the water. Awaiting comments on that one.
Well rather than me dismissing Haisch on arguments with words, how about if we get to numbers   :). Can quantitative predictions be made based on (Compton resonance Haisch Reuda) ?

Yes

http://xxx.lanl.gov/pdf/gr-qc/9906084v3.pdf

What we need is a calculation using this theory that comes close to the measured thrust force.  Where is such a calculation?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 06:41 pm
I really want some feedback concerning my comments trying to shut down dark matter. Good science is trying to break things.

I'm not sure its time to shut down dark matter as a possibility. Attached is another estimate of dark matter in the solar system, from

 http://www.universetoday.com/15266/dark-matter-is-denser-in-the-solar-system/ (http://www.universetoday.com/15266/dark-matter-is-denser-in-the-solar-system/)

It is not quite as high as the upper limits given earlier, but quite close: 2.99E-17 kg/m^3 verses 1.40E-16 kg/m^3 . That is about a factor of 5 lower.

My point is that we don't know enough about dark matter to rule it out yet. All of these estimates are for dark matter in space but we know that dark matter is gravitationally attracted to mass (read "Earth") so can we say with any confidence what the dark matter density is at the surface of the Earth where the gravitational field is much stronger?

Further, the small end of the cavity is about .022 m^3, but the large end is about 0.05 m^2. There was the mention of an effect akin to antenna gain earlier. That has not been considered.

It seems to me that in order for the effect to be due to dark matter, and allowing for some conceptual inefficiencies,  there needs to be about 3 orders of magnitude more dark matter accelerated by the thruster than has so far been estimated.

JMO, but we don't know enough to rule out dark matter at this point.

Akin to my previous logic, the universe would need to be absolutely saturated with dark matter and folded up upon itself and the emdrive would not work using dark matter solely because it doesn't interact with by anything. A photon would then interact with it solely by the mass energy the photon possesses from its momentum, giving rise to its own gravity. Photons work like this, and that is why you get gravitational lensing.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 06:44 pm

In order from simple/likely to not simple/unlikely top 6:
1. It doesn't work, they got it wrong by some means I don't know and neither do they.
2. The generally accepted ideas for inertial mass are correct and it still works but by some other way, and isn't useful.
2.5 Same as above but is useful.
3. Inertial mass works some other way; Unruh, zpf/casimir McCulloch et al
4. Inertial mass works some other way; De Broglie Compton resonance Haisch Reuda
5. Inertial mass works some other way; EM ZPF, Haisch et al

Ok I conceded some by the modifications I made. Removed heat, put x in its spot. Unruh has a , after it. 4 and 5 remain. I blew dark matter out of the water. Awaiting comments on that one.
Well rather than me dismissing Haisch on arguments with words, how about if we get to numbers   :). Can quantitative predictions be made based on (Compton resonance Haisch Reuda) ?

Yes

http://xxx.lanl.gov/pdf/gr-qc/9906084v3.pdf

What we need is a calculation using this theory that comes close to the measured thrust force.  Where is such a calculation?

We gotta do it. Nobody but me as far as I know has said this is why emdrive might work. I ain't gifted enough to go alone. Read the paper, it is salient as far as I can tell in the respect of how controversial the origin or inertial mass is. I like how the paper says, "in part responsible for inertial mass." That is why I connected this to emdrive.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 06:53 pm
I really want some feedback concerning my comments trying to shut down dark matter. Good science is trying to break things.

I'm not sure its time to shut down dark matter as a possibility. Attached is another estimate of dark matter in the solar system, from

 http://www.universetoday.com/15266/dark-matter-is-denser-in-the-solar-system/ (http://www.universetoday.com/15266/dark-matter-is-denser-in-the-solar-system/)

It is not quite as high as the upper limits given earlier, but quite close: 2.99E-17 kg/m^3 verses 1.40E-16 kg/m^3 . That is about a factor of 5 lower.

My point is that we don't know enough about dark matter to rule it out yet. All of these estimates are for dark matter in space but we know that dark matter is gravitationally attracted to mass (read "Earth") so can we say with any confidence what the dark matter density is at the surface of the Earth where the gravitational field is much stronger?

Further, the small end of the cavity is about .022 m^3, but the large end is about 0.05 m^2. There was the mention of an effect akin to antenna gain earlier. That has not been considered.

It seems to me that in order for the effect to be due to dark matter, and allowing for some conceptual inefficiencies,  there needs to be about 3 orders of magnitude more dark matter accelerated by the thruster than has so far been estimated.

JMO, but we don't know enough to rule out dark matter at this point.

Akin to my previous logic, the universe would need to be absolutely saturated with dark matter and folded up upon itself and the emdrive would not work using dark matter solely because it doesn't interact with by anything. A photon would then interact with it solely by the mass energy the photon possesses from its momentum, giving rise to its own gravity. Photons work like this, and that is why you get gravitational lensing.

Inverse Primakov effect

http://arxiv.org/abs/hep-ph/0701198
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 06:56 pm
I really want some feedback concerning my comments trying to shut down dark matter. Good science is trying to break things.

I'm not sure its time to shut down dark matter as a possibility. Attached is another estimate of dark matter in the solar system, from

 http://www.universetoday.com/15266/dark-matter-is-denser-in-the-solar-system/ (http://www.universetoday.com/15266/dark-matter-is-denser-in-the-solar-system/)

It is not quite as high as the upper limits given earlier, but quite close: 2.99E-17 kg/m^3 verses 1.40E-16 kg/m^3 . That is about a factor of 5 lower.

My point is that we don't know enough about dark matter to rule it out yet. All of these estimates are for dark matter in space but we know that dark matter is gravitationally attracted to mass (read "Earth") so can we say with any confidence what the dark matter density is at the surface of the Earth where the gravitational field is much stronger?

Further, the small end of the cavity is about .022 m^3, but the large end is about 0.05 m^2. There was the mention of an effect akin to antenna gain earlier. That has not been considered.

It seems to me that in order for the effect to be due to dark matter, and allowing for some conceptual inefficiencies,  there needs to be about 3 orders of magnitude more dark matter accelerated by the thruster than has so far been estimated.

JMO, but we don't know enough to rule out dark matter at this point.

Akin to my previous logic, the universe would need to be absolutely saturated with dark matter and folded up upon itself and the emdrive would not work using dark matter solely because it doesn't interact with by anything. A photon would then interact with it solely by the mass energy the photon possesses from its momentum, giving rise to its own gravity. Photons work like this, and that is why you get gravitational lensing.

Inverse Primakov effect

http://arxiv.org/abs/hep-ph/0701198

Ok I'm reading it. I'm also reading up on tunnel diodes for you. At some point, we need to stop adding layers of complexity and start focusing on what we got and rule them out as a team from order of least to most likely.

What is the connection to emdrive for the axion paper? Is it the strong cp problem or the dark matter candidate? I'm really trying here. Lead me the right way. Is it the Dichroism that is the interest?
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 07:11 pm

Ok I'm reading it. I'm also reading up on tunnel diodes for you. At some point, we need to stop adding layers of complexity and start focusing on what we got and rule them out as a team from order of least to most likely.

What is the connection to emdrive for the axion paper? Is it the strong cp problem or the dark matter candidate? I'm really trying here. Lead me the right way.
The dark matter candidate .  I have to go now.  'Later
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 07:26 pm
I think we need to combine the forum's conclusions in a living document. Even though science is not democratic, I don't want to keep beating dead horses that have been decided on as fact (not to say any of my ideas are generally accepted or anything). Do you agree? If so, we could implement it using this forum or a shared google doc.

I would say, do it on this forum.  Perhaps start a thread, "Anomalous Thrust Theory Lineup", or something.  In the OP, state the "living document nature" of the thread, and ask that others not post, just you.

The principle is like the political SpaceEx vs ULA lawsuit update thread, which is separate from the discussion thread.  the primary benefit would be that the "Living Document" thread, with one author, who would link to pertinent work by the others of your gang of genii as required, would be very short and cogently written.

The links would supply the background knowledge.  The second post would be an executive summary of the several theoretical approaches to date.  Subsequent posts would elaborate on the pros and cons of each approach, along with current suggestions of experimental apparatus.

This would require much of you, in that, were someone to object to this or that phraseology or terminology, or even propose another approach, they should be honor bound to discuss it with you via PM.  If a dissenting voice persists, the "Living Document" could at least say something along the lines of So-and-so disagrees with the "pony to unicorn transition", and link back to this thread for moree info.

The key benefit to all is the long, messy thread supports the short concise thread.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 07:27 pm
I really want some feedback concerning my comments trying to shut down dark matter. Good science is trying to break things.

Agreed, but good science also takes time to enable thoughtful responses. Just like thermal effects  :)

Brain overheating again, good buddy?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 07:35 pm
The more far fetched we get here, creating more and more complex explanations, probably won't help us. Seems the most simple explanations are more likely correct. Occam's razor and all. I'm ready to start shutting down theories. I also intend to make my critical analysis of the paper more known in detail as soon as I can.

Occam's razor is a good thing.  You left the peanut gallery in the dust about thirty pages ago.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 07:36 pm

Ok I'm reading it. I'm also reading up on tunnel diodes for you. At some point, we need to stop adding layers of complexity and start focusing on what we got and rule them out as a team from order of least to most likely.

What is the connection to emdrive for the axion paper? Is it the strong cp problem or the dark matter candidate? I'm really trying here. Lead me the right way.
The dark matter candidate .  I have to go now.  'Later

Ok axions are intriguing and I just gulped down a bunch of info. I gathered they are very low mass, barely detectable, and you need a very very high magnetic field to detect them or interact with them by turning them into photons, which are photons that were once non interacting axions. So photons from nothing, which would add energy to the system that is detecting them. There is something there, but I need to read more. A neat but probably loose connection I'm intrigued to make is that the QCD vacuum is paramagnetic. I don't think the emdrive makes anywhere high enough magnetic flux to play in here but it is a hunch. Math help please? Look we can all focus on this one at once if you like. I just want to get us all on the same page, I can put it at 6 on the list and we can ALL work together on it. I'm saying at 6 solely because while it is eye catching, the very early info I got from the best source for bs science in the world (wikipedia)  :P says "It had been thought that the invisible axion provides a solution to the strong CP problem without being amenable to verification by experiment or observation. In invisible axion models, the axion is chosen to be so weakly coupled that it does not appear in any of the experiments that had been attempted to detect it."

Body of info I have so far:
http://arxiv.org/pdf/hep-ph/0701198v1.pdf
en.wikipedia.org/wiki/Axion
http://en.wikipedia.org/wiki/Primakoff_effect
http://en.wikipedia.org/wiki/Peccei%E2%80%93Quinn_theory
https://www.google.com/search?q=Axion+Dark+Matter+eXperiment+%28ADMX%29&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=rcs


Break time. I've been on this too much.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 07:51 pm
I think we need to combine the forum's conclusions in a living document. Even though science is not democratic, I don't want to keep beating dead horses that have been decided on as fact (not to say any of my ideas are generally accepted or anything). Do you agree? If so, we could implement it using this forum or a shared google doc.

I would say, do it on this forum.  Perhaps start a thread, "Anomalous Thrust Theory Lineup", or something.  In the OP, state the "living document nature" of the thread, and ask that others not post, just you.

The principle is like the political SpaceEx vs ULA lawsuit update thread, which is separate from the discussion thread.  the primary benefit would be that the "Living Document" thread, with one author, who would link to pertinent work by the others of your gang of genii as required, would be very short and cogently written.

The links would supply the background knowledge.  The second post would be an executive summary of the several theoretical approaches to date.  Subsequent posts would elaborate on the pros and cons of each approach, along with current suggestions of experimental apparatus.

This would require much of you, in that, were someone to object to this or that phraseology or terminology, or even propose another approach, they should be honor bound to discuss it with you via PM.  If a dissenting voice persists, the "Living Document" could at least say something along the lines of So-and-so disagrees with the "pony to unicorn transition", and link back to this thread for moree info.

The key benefit to all is the long, messy thread supports the short concise thread.

I don't know how to make that work and not be a mess and take up some poor poster's time. We all have lives to tend to. I'm down for a shared google doc. They have access control and versioning.

http://www.google.com/docs/about/

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/05/2014 07:59 pm
I think we need to combine the forum's conclusions in a living document. Even though science is not democratic, I don't want to keep beating dead horses that have been decided on as fact (not to say any of my ideas are generally accepted or anything). Do you agree? If so, we could implement it using this forum or a shared google doc.

I would say, do it on this forum.  Perhaps start a thread, "Anomalous Thrust Theory Lineup", or something.  In the OP, state the "living document nature" of the thread, and ask that others not post, just you. ...

The key benefit to all is the long, messy thread supports the short concise thread.

I don't know how to make that work and not be a mess and take up some poor poster's time. We all have lives to tend to. I'm down for a shared google doc. They have access control and versioning.

http://www.google.com/docs/about/

The key factor for it to work is the honor system and no random posts.  The mods, properly asked (which is to say in part, not by me) may help with that.

As to the poor poster, see your PM.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 07:59 pm
https://drive.google.com/folderview?id=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM&usp=sharing

Done.

Edit:
Google Drive provides information security safeguards so I'm making it public.

https://support.google.com/a/answer/172541?hl=en


Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 08:03 pm
I already had a google drive folder with a few things in it so I just made this happen quickly and easily.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/05/2014 09:27 pm
Quote
Well, for the argument, that could also be a neutrino jet, or any light particle with more kinetic energy than rest mass. The photon with a 0 rest mass is just a limit case. Also this is getting convoluted : have to take incoming DM <500km/s, and convert mass content to kinetic energy of collimated ejected relativistic particles that are light enough (otherwise they are less relativistic, and thrust is worse) and wall crossing (neutrinos, X rays). Mmm, you could even do the following : take incoming DM <500km/s, convert mass to energy, and with the energy of 1 million DM particles, accelerate 1 DM particle at relativistic speed.

Would be dark matter powered dark matter jet rocket. Call that a "dark matter ramjet". Unless anyone can point me to previous publication or grant, I hereby take precedence on that concept  8)

An SF author, Mike Brotherton, beat you to it in 2008.  His 'dark drive,' a sort of 'dark matter bussard ramjet,' was the drive for his starships in 'Spider Star.'  Worth noting: before writing SF, he had a PHD in Astronomy, held a research position at 'Lawrence Livermore National Laboratory' (whatever that is:) ) and Kitt Peak National Observatory.  Seems to be a bit of an X-Ray expert.  However, the description of his 'dark drive' was superficial.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 10:13 pm
On the subject of wall crossing particles, anyone have any ideas on how a particle within the emdrive could be wall crossing at the big end but not the other walls given how it was designed?
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 10:18 pm
On the subject of wall crossing particles, anyone have any ideas on how a particle within the emdrive could be wall crossing at the big end but not the other walls given how it was designed?

Take a look at the differences between the walls of the tapered cavity and its ends.  The walls are metallic (copper).  The end surfaces appear to be circuit board polymer material perhaps PCB.  I recall that @notsosureofit recognized the circuit board material as material @notsosureofit has in house.

There appears to be a difference in color between the large and smaller end surfaces, but it may just be a matter of lighting.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 10:18 pm
Yes, long wavelength interaction w/ a condensate of bosons acts like a phonon generation.

It's in here: http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

My head hertz.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 10:30 pm
The fact that operating at a frequency of 1937 MHz has a Q more than 4 times higher but a thrust force 1/2 as much as operating at a frequency of 1933 MHz is extremely problematic for all these inertia theories if they ignore the dielectric:

1) McCulloch  (Unruth radiation)
2) the ZPF and Cassimir effect theories

because the frequencies are practically the same (0.3% difference between them) yet the thrust forces differ by a factor of 2.  Also the effect is very contrary to Prof. McCulloch  's model which is proportional to Q and inversely proportional to frequency.  The thrust at 1937 is 1/2 as much while according to McCulloch's formula should be 4 times as high.

All the ZPF theories have similar problems. This is a death knell for all of them if they ignore the dielectric.

Again, an analysis of this effect needs a consideration of the dielectric thermoplastic.  It may be difficult to consider the dielectric thermoplastic effect in all of this (including its nonlinearity), but the data all points in that direction.  Einstein said to make things as easy as possible but never simpler than necessary.  Any theory that ignores the dielectric cannot explain the results
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 10:38 pm
Yes, long wavelength interaction w/ a condensate of bosons acts like a phonon generation.

It's in here: http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

My head hertz.

Somebody call NDT!
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 10:45 pm
The fact that operating at a frequency of 1937 MHz has a Q more than 4 times higher but a thrust force 1/2 as much as operating at a frequency of 1933 MHz is extremely problematic for all these inertia theories if they ignore the dielectric:

1) McCulloch  (Unruth radiation)
2) the ZPF and Cassimir effect theories

because the frequencies are practically the same (0.3% difference between them) yet the thrust forces differ by a factor of 2.  Also the effect is very contrary to Prof. McCulloch  's model which is proportional to Q and inversely proportional to frequency.  The thrust at 1937 is 1/2 as much while according to McCulloch's formula should be 4 times as high.

All the ZPF theories have similar problems. This is a death knell for all of them if they ignore the dielectric.

Again, an analysis of this effect needs a consideration of the dielectric thermoplastic.  It may be difficult to consider the dielectric thermoplastic effect in all of this (including its nonlinearity), but the data all points in that direction.  Einstein said to make things as easy as possible but never simpler than necessary.  Any theory that ignores the dielectric cannot explain the results

I can't argue with that. It is dependent on how tightly the dielectric modes are constrained. I saw that discrepancy and didn't question it. Good job.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 10:46 pm
somebody call the Nuclear Decommissioning Trust ? :)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 10:48 pm
Yes, long wavelength interaction w/ a condensate of bosons acts like a phonon generation.

It's in here: http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

My head hertz.

Somebody call NDT!


So anyway, what that all means is: if the cloud of dark matter is composed of axions AND if they have formed (as was in some axion paper back there) a Bose-Einstein condensate, one does not need enough energy to create axions, just enough to raise the state of some.  If you do this the exitation propagates like a "phonon" in the condensate, which is a momentum transfer against the entire condensate (ie the "ocean to push against)

Highly speculative, who wants to try a calculation ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 10:50 pm
somebody call the Nuclear Decommissioning Trust ? :)

Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 10:52 pm
Yes, long wavelength interaction w/ a condensate of bosons acts like a phonon generation.

It's in here: http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

My head hertz.

Somebody call NDT!


So anyway, what that all means is: if the cloud of dark matter is composed of axions AND if they have formed (as was in some axion paper back there) a Bose-Einstein condensate, one does not need enough energy to create axions, just enough to raise the state of some.  If you do this the exitation propagates like a "phonon" in the condensate, which is a momentum transfer against the entire condensate (ie the "ocean to push against)

Highly speculative, who wants to try a calculation ?

I never thought I would "like" a thing about dark matter. I have believed two impossible things today.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 11:00 pm
The fact that operating at a frequency of 1937 MHz has a Q more than 4 times higher but a thrust force 1/2 as much as operating at a frequency of 1933 MHz is extremely problematic for all these inertia theories if they ignore the dielectric:

1) McCulloch  (Unruth radiation)
2) the ZPF and Cassimir effect theories

because the frequencies are practically the same (0.3% difference between them) yet the thrust forces differ by a factor of 2.  Also the effect is very contrary to Prof. McCulloch  's model which is proportional to Q and inversely proportional to frequency.  The thrust at 1937 is 1/2 as much while according to McCulloch's formula should be 4 times as high.

All the ZPF theories have similar problems. This is a death knell for all of them if they ignore the dielectric.

Again, an analysis of this effect needs a consideration of the dielectric thermoplastic.  It may be difficult to consider the dielectric thermoplastic effect in all of this (including its nonlinearity), but the data all points in that direction.  Einstein said to make things as easy as possible but never simpler than necessary.  Any theory that ignores the dielectric cannot explain the results

Also this analysis of mode shapes  Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html cannot explain the experimental results.

The energy density for both the magnetic and electric fields increase with the frequency. This analysis cannot   explain the fact that the thrust would differ by a factor of 2 at frequencies less than 0.3% apart.

Either this is due to:

a) The actual cavity is not rotationally symmetric (the only hint of this is the off center inner circle)
or
b) the effect is not at all due to the mode shape but something to do with the dielectric not that related to mode shape (and even less related to Q )

Based on my experience (I have not done an analysis yet) I favor b) since I cannot justify such huge differences for this geometry based on such a small frequency difference.

There is something important we are missing here
Title: Re: EM Drive Developments
Post by: Stormbringer on 10/05/2014 11:02 pm
WRT to nature not providing a means for having that hoverboard thing... nature does allow for it. practical considerations get in the way; but nature allows it. You just have to overcome a magnetic to gravity coupling factor of trillions to one according to GR. (i learnt that when reading about the ESA and Martin Tajmar's paper.) It does not matter much that Tajmar recanted. His recantation does not negate GR itself.)

but the upshot is you can have a hover board. it's probably be the size of the empire state building laid on it's side but you could have one. In theory at least.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 11:05 pm
We're finding transformations here in this forum at pretty much every energy level, relating to converting electricity to mechanical thrust. It is becoming apparent to me that the underlying mechanisms for why the emdrive might have done something, is a complex mechanism taking place at several energy levels at once, with transformations in between. As in real life, most things happen on a spectrum and aren't cut and dry. The modes we can access depend on the limits of our technology, so indeed it seems likely that most of the effect is dielectric related in this test article. If it works, we can continually optimize it by accessing greater and greater energies as technology evolves. I hope we can influence some folks to come over and really tear this problem apart.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 11:10 pm
The fact that operating at a frequency of 1937 MHz has a Q more than 4 times higher but a thrust force 1/2 as much as operating at a frequency of 1933 MHz is extremely problematic for all these inertia theories if they ignore the dielectric:

1) McCulloch  (Unruth radiation)
2) the ZPF and Cassimir effect theories

because the frequencies are practically the same (0.3% difference between them) yet the thrust forces differ by a factor of 2.  Also the effect is very contrary to Prof. McCulloch  's model which is proportional to Q and inversely proportional to frequency.  The thrust at 1937 is 1/2 as much while according to McCulloch's formula should be 4 times as high.

All the ZPF theories have similar problems. This is a death knell for all of them if they ignore the dielectric.

Again, an analysis of this effect needs a consideration of the dielectric thermoplastic.  It may be difficult to consider the dielectric thermoplastic effect in all of this (including its nonlinearity), but the data all points in that direction.  Einstein said to make things as easy as possible but never simpler than necessary.  Any theory that ignores the dielectric cannot explain the results

Also this analysis of mode shapes  Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html cannot explain the experimental results.

The energy density for both the magnetic and electric fields increase with the frequency. This analysis cannot   explain the fact that the thrust would differ by a factor of 2 at frequencies less than 0.3% apart.

Either this is due to:

a) The actual cavity is not rotationally symmetric (the only hint of this is the off center inner circle)
or
b) the effect is not at all due to the mode shape but something to do with the dielectric not that related to mode shape (and even less related to Q )

Based on my experience (I have not done an analysis yet) I favor b) since I cannot justify such huge differences for this geometry based on such a small frequency difference.

There is something important we are missing here

I cannot justify such a huge difference on thrust

Well the Cannae did provide a thrust too, and it isn't shaped like a bell. I previously asserted the pillbox didn't matter, and way way back in my posts, I advised to design the thing instead taking cues from coax cables, and cluster them, because of the Cannae tube. Later I dropped that in favor of clustering cone shapes in a wafer. Maybe I was right the first time.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/05/2014 11:16 pm
Yes, long wavelength interaction w/ a condensate of bosons acts like a phonon generation.

It's in here: http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

My head hertz.

Somebody call NDT!


So anyway, what that all means is: if the cloud of dark matter is composed of axions AND if they have formed (as was in some axion paper back there) a Bose-Einstein condensate, one does not need enough energy to create axions, just enough to raise the state of some.  If you do this the exitation propagates like a "phonon" in the condensate, which is a momentum transfer against the entire condensate (ie the "ocean to push against)

Highly speculative, who wants to try a calculation ?

I never thought I would "like" a thing about dark matter. I have believed two impossible things today.

Gotta keep turnin ova rocks :http://arxiv.org/pdf/1303.1137v1.pdf

This last is an experimental demonstration.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 11:20 pm
..
Well the Cannae did provide a thrust too, and it isn't shaped like a bell. I previously asserted the pillbox didn't matter, and way way back in my posts, I advised to design the thing instead taking cues from coax cables, and cluster them, because of the Cannae tube. Later I dropped that in favor of clustering cone shapes in a wafer. Maybe I was right the first time.
Yes you deserve lots of credit for that.  There has been an assumption about the cavity and the Q that are completely negated by the experimental results.

But this doesn't mean that this is a propellant less device.  The effect still maybe an artifact due to the magnetic damper field interacting with the power cable and the dielectric.

The first thing that NASA should do is:

run everything from a battery, self-contained, as done by Brito, Marini and Galian

damp the pendulum with oil or other non-magnetic damper as done by Brito, Marini and Galian


No external power
No magnetic field from the magnetic damper

There are a number of people in this forum that have asked for this to go into space.  This thing should first be run with a battery and without a magnetic damper.  That should be much faster, easier and cheaper to do than sending this into space.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/05/2014 11:27 pm
Someone will read our ramblings. Some will laugh but some will raise an eyebrow. Btw I shared ALL my bookmarks on the Google Drive doc. Now I'm going to sleep. Later.
Title: Re: EM Drive Developments
Post by: aero on 10/05/2014 11:52 pm
The fact that operating at a frequency of 1937 MHz has a Q more than 4 times higher but a thrust force 1/2 as much as operating at a frequency of 1933 MHz is extremely problematic for all these inertia theories if they ignore the dielectric:

1) McCulloch  (Unruth radiation)
2) the ZPF and Cassimir effect theories

because the frequencies are practically the same (0.3% difference between them) yet the thrust forces differ by a factor of 2.  Also the effect is very contrary to Prof. McCulloch  's model which is proportional to Q and inversely proportional to frequency.  The thrust at 1937 is 1/2 as much while according to McCulloch's formula should be 4 times as high.

All the ZPF theories have similar problems. This is a death knell for all of them if they ignore the dielectric.

Again, an analysis of this effect needs a consideration of the dielectric thermoplastic.  It may be difficult to consider the dielectric thermoplastic effect in all of this (including its nonlinearity), but the data all points in that direction.  Einstein said to make things as easy as possible but never simpler than necessary.  Any theory that ignores the dielectric cannot explain the results

Also this analysis of mode shapes  Took a while to find this again.
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html cannot explain the experimental results.

The energy density for both the magnetic and electric fields increase with the frequency. This analysis cannot   explain the fact that the thrust would differ by a factor of 2 at frequencies less than 0.3% apart.

Either this is due to:

a) The actual cavity is not rotationally symmetric (the only hint of this is the off center inner circle)
or
b) the effect is not at all due to the mode shape but something to do with the dielectric not that related to mode shape (and even less related to Q )

Based on my experience (I have not done an analysis yet) I favor b) since I cannot justify such huge differences for this geometry based on such a small frequency difference.

There is something important we are missing here

I cannot justify such a huge difference on thrust

Well the Cannae did provide a thrust too, and it isn't shaped like a bell. I previously asserted the pillbox didn't matter, and way way back in my posts, I advised to design the thing instead taking cues from coax cables, and cluster them, because of the Cannae tube. Later I dropped that in favor of clustering cone shapes in a wafer. Maybe I was right the first time.

Well, the frequency is only a little different but the drive power is also a lot different. So is the energy within the cavity a lot different.

If the energy is coupling with some unknown particle couldn't it be quite sensitive to the rate of change of wave amplitude (frequency and power) within the cavity? So what would the mass of the particle need to be in order for it couple with more strongly in one case than the other? Just throwing it out there.
Title: Re: EM Drive Developments
Post by: Rodal on 10/05/2014 11:59 pm

Well, the frequency is only a little different but the drive power is also a lot different. So is the energy within the cavity a lot different.

If the energy is coupling with some unknown particle couldn't it be quite sensitive to the rate of change of wave amplitude (frequency and power) within the cavity? So what would the mass of the particle need to be in order for it couple with more strongly in one case than the other? Just throwing it out there.

Please help me with more info.  I see the input power to be the same 17 watts (see attached table, first two rows).  Where  is the info that the drive power is a lot different?
Title: Re: EM Drive Developments
Post by: aero on 10/06/2014 12:20 am

Well, the frequency is only a little different but the drive power is also a lot different. So is the energy within the cavity a lot different.

If the energy is coupling with some unknown particle couldn't it be quite sensitive to the rate of change of wave amplitude (frequency and power) within the cavity? So what would the mass of the particle need to be in order for it couple with more strongly in one case than the other? Just throwing it out there.

Please help me with more info.  I see the input power to be the same 17 watts (see attached table, first two rows).  Where  is the info that the drive power is a lot different?

O goodness me. I was thinking of TE012 without verifying it. In the two TM211 cases there is a difference in energy within the chamber, but not drive energy. I do think the TE012 case is interesting, too. That is the case where there is a big difference in the drive power and cavity energy with about 3% difference in frequency. The FOM is highest for TE012 too, over 3 times higher than the closest other case, and 6 times higher than the poorest FOM case. (FOM = thrust/drive power) So that mystery particle I alluded to couples even more strongly at the lower frequency of TE012 with much lower amplitude of the magnetic/electric fields of the RF wave.

Does that mean that the mystery particle is more massive than would be ideal for the frequencies tested?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 12:31 am
Ok I can't sleep so I hopped to polywell to lurk and read this:
http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=2949&start=240#p116102

If this really is Woodward's assumption. We can put it to bed. We just discussed this. I find it hard to believe he has confused mass energy within the atom with energies of covalent bonds.

Woodward's theory might work as described above if he pumped it with gamma rays and didn't blast the molecules apart in the process. The only other way is to relativistically accelerate the device, which would melt it down more than likely. If we could do that, we probably have neater stuff than emdrives.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 12:35 am
Ok I can't sleep so I hopped to polywell to lurk and read this:
http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=2949&start=240#p116102

If this really is Woodward's assumption We can put it to bed. We just discussed this.I find it hard to believe he has confused mass energy within the atom with energies of covalent bonds.

Ha  :) they are talking about me over there? 

Ron it looks like they are also talking about you.

I also see that birchoff and aceshigh are over there. Hi guys  :)

~~~~~~~~~~~~~~~~~

Anyway, let's keep the eyes on the ball.  The important issue is that all the theories (including the report) concerning the cavity "Q" are falsified by the experiments.  There is a lot of nonlinearity according to the data (0.3% change in frequency doubles the thrust).  Also as @aero pointed out increasing input power by a factor of 6 (from 2.6 to 16.7 watts) ends up with practically the same thrust force.


The fact that there is a lot of nonlinearity means that scaling this thing up is a huge problem

Using Specific Force (Force/InputPower) is negated by the experimental data.  Force/InputPower according to the data is not a linear parameter of the system.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:54 am
Also (too lazy to search) it was made mention to AC...

I thought it was all AC.  Where's the DC coming from?

Now with a very very scarce medium, the amount of mass/s that can be swallowed by the thruster is so weak that it takes very high ejection speeds to get a thrust level of any significance. When the scarcity of the medium implies relativistic ejection velocities to get interesting thrust, then the fact need [my edit?] to use a medium mass at all becomes irrelevant because you put more energy as kinetic energy than the energy equivalence of harvested mass : if you have that much onboard energy to spend on kinetic energy of the jet, then just creating the rest mass (from energy) of what you are ejecting becomes a negligible term. You are almost as good with a photon rocket and ignoring the medium.

Having had a propeller beanie as a kid, I hang on to that concept concept.  Thanking you again, I continue:.

If it is to be a ramjet, then the intake has to be physically very large.  You can't make it out of matter, you'd have to somehow project a field to harvest the DM as you move thru it, and maybe condense it.  You'd have to start the ramjet going somehow (boom boom Orion?), and discard that stage when the ramjet starts working.

Anyhow, it would not be pushing on the quantum field, and it would have a tailpipe.  I'm thinking you can't suck it up, you have to move thru it.

I'm trying to visualize what a useful spacecraft might look like. Which may be uncomfortably close to speculating about benign wormholes, but hey.

All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.

Riffing on the spacecraft scale for a sec:  Those tubes would be kilometers in diameter? no?

Anyhow, one of my daughter's friends had a band called, well, look at my hat.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:59 am
At what Hertz frequency does your head hertz ? Or should I ask what does the mode shape look like?  :)

Pointd, or conical?

whoops.  Gotta go....
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 01:05 am
Ok I can't sleep so I hopped to polywell to lurk and read this:
http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=2949&start=240#p116102

If this really is Woodward's assumption. We can put it to bed. We just discussed this. I find it hard to believe he has confused mass energy within the atom with energies of covalent bonds.

...

Did I not talk about the "lattice" being the chemical bonds holding the molecule together?
Title: Re: EM Drive Developments
Post by: aero on 10/06/2014 01:48 am
Quote
Using Specific Force (Force/InputPower) is negated by the experimental data.  Force/InputPower according to the data is not a linear parameter of the system.

That's right. In fact the only linear thing I see in the data is case number verses number of test runs :)

It is even a challenge to identify single valued relationships that might have meaning.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 01:55 am
Quote
Using Specific Force (Force/InputPower) is negated by the experimental data.  Force/InputPower according to the data is not a linear parameter of the system.

That's right. In fact the only linear thing I see in the data is case number verses number of test runs :)

It is even a challenge to identify single valued relationships that might have meaning.
@mulletron the data looks so nonlinear that you might want to reconsider whether the system is acting like a van der Pool oscillator, with the dielectric as a tunnel diode.
Title: Re: EM Drive Developments
Post by: DIYFAN on 10/06/2014 02:05 am
Lurker and former engineer here making first post.  I'm intrigued by the theoretical outlays here, but wondering how many among us are potential DIY experimentalists?  I believe that sufficient information is now accessible to the public to independently replicate and confirm this technology widely.  I envision something along the lines of the DIY drone developers and their enthusiasm for advancing that field, with a rapid feedback loop and dispersion of information.

For starters, here is the latest published patent application:
http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=20130206&CC=GB&NR=2493361A&KC=A (http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=20130206&CC=GB&NR=2493361A&KC=A)

YBCO superconducting film to line the inner cavity:
http://www.mtixtl.com/YBCO100nm-film-SrTiO3-101005.aspx (http://www.mtixtl.com/YBCO100nm-film-SrTiO3-101005.aspx)

3GHz+ signal generators:
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR5.TRC1.A0.H0.X3ghz+signal+generator&_nkw=3ghz+signal+generator&_sacat=0 (http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR5.TRC1.A0.H0.X3ghz+signal+generator&_nkw=3ghz+signal+generator&_sacat=0)

Microwave power amplifiers:
http://www.ebay.com/sch/i.html?_odkw=microwave+signal+amplifier&_from=R40|R40|R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xmicrowave+power+amplifier&_nkw=microwave+power+amplifier&_sacat=0 (http://www.ebay.com/sch/i.html?_odkw=microwave+signal+amplifier&_from=R40|R40|R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xmicrowave+power+amplifier&_nkw=microwave+power+amplifier&_sacat=0)

The architectural design, materials, and concepts are described in a fairly straight-forward manner in the patent publication.  YBCO film is superconducting above liquid nitrogen boiling point.  I estimate that an experiment could be put together for less than $2000 of parts.  Of course, the requisite time and knowledge for carrying it out would need to be conducted, probably with no compensation.  Who among us are willing and able?  Is there a Steve Jobs of propellentless devices among these ranks?  My thought is that to advance this tech quickly, technically capable and independent people, not beholden too much to dogma or larger institutions, are going to have to run with it and spread it as far and wide as possible.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 02:34 am
Lurker and former engineer here making first post. ..
Welcome to this forum !   :)
Title: Re: EM Drive Developments
Post by: aceshigh on 10/06/2014 02:58 am
[quote author=Rodal link=topic=29276.msg1266840#msg1266840 date=1412555744

Ha  :) they are talking about me over there? 

Ron it looks like they are also talking about you.

I also see that birchoff and aceshigh are over there. Hi guys  :)
[/quote]

I thought that was pretty clear as i mentioned that it was on talk polywell that i talked to Paul March and told him about the discussion here. I mentioned a few times too that i was like message boy between here and talk polywell and next big future and i would not continue bringing messages from one forum to another.
Title: Re: EM Drive Developments
Post by: aceshigh on 10/06/2014 03:08 am
Quote from: ThinkerX link=topic=29276.msg1266791#msg128_
An SF author, Mike Brotherton, beat you to it in 2008.  His 'dark drive,' a sort of 'dark matter bussard ramjet,' was the drive for his starships in 'Spider Star.'  Worth noting: before writing SF, he had a PHD in Astronomy, held a research position at 'Lawrence Livermore National Laboratory' (whatever that is:) ) and Kitt Peak National Observatory.  Seems to be a bit of an X-Ray expert.  However, the description of his 'dark drive' was superficial.

Haha, i almost posted about Mike Brothertons drive from his other book Star Dragon, where they are able to form a singularity and split it in black and a white hole, and somehow (i forgot how) the ship moves along. (John Fornaro had mentioned something about black hole drives)

Btw, dr Brotherton is an astro physicist.
Title: Re: EM Drive Developments
Post by: Stormbringer on 10/06/2014 06:18 am
Quote from: ThinkerX link=topic=29276.msg1266791#msg128_
An SF author, Mike Brotherton, beat you to it in 2008.  His 'dark drive,' a sort of 'dark matter bussard ramjet,' was the drive for his starships in 'Spider Star.'  Worth noting: before writing SF, he had a PHD in Astronomy, held a research position at 'Lawrence Livermore National Laboratory' (whatever that is:) ) and Kitt Peak National Observatory.  Seems to be a bit of an X-Ray expert.  However, the description of his 'dark drive' was superficial.

Haha, i almost posted about Mike Brothertons drive from his other book Star Dragon, where they are able to form a singularity and split it in black and a white hole, and somehow (i forgot how) the ship moves along. (John Fornaro had mentioned something about black hole drives)

Btw, dr Brotherton is an astro physicist.

its easy. with one end negative and the other positive mass or energy you get a situation where when normal forces push one of the ends of the drive that end moves in the opposite way that ordinary energy or matter mass would and moves towards the force if you can keep the ends apart the thing accelerates on it's own basically forever. that's one of the drives mentioned briefly in Woodward's video in the question and answer session at the end of the video.
Title: Re: EM Drive Developments
Post by: 93143 on 10/06/2014 07:06 am
I find it hard to believe he has confused mass energy within the atom with energies of covalent bonds.

They're the same thing.  They both gravitate and have inertia.  The scale is wildly different, but that's immaterial.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 07:24 am
Building on what I was going on about earlier concerning where mass energy and self energy lie. Given Woodward's assertions about exciting an oscillation in a dielectric and then pushing on it at an opportune time to move forward clearly does violate conservation of momentum. Tying that in with mass energy and self energy, it is clear that SPACIALLY, mass energy (constrained within spacetime) are a symmetric quantity with a conservation associated to it in the spirit of Noether. You can't violate it this way. But I have two crazy ideas to believe stemming from looking at the emdrive problem from the other end of the spectrum, the conservation of momentum, which it breaks if it works right? Let's see. First an observation. It seems clear that as we approach unification of all physical interactions, or singularity, those symmetries we depend on and their associated conservations begin to yield one at a time. At the end you're left in a situation where mass is not significant and everything is massless. That's my first observation. At x energy, conservation of momentum should break. Where? How is it related to the strong CP problem? Or perhaps that is too deep, how about just P symmetry. P symmetry is key.

Remember that mass is constrained over space and energy is constrained over time!
Also remember that a polarized cap and a unpolarized cap DO FALL at exactly the same rate.
Keep this in mind when wrapping your head around this stuff.
Don't forget about the effect of 3d shapes and cavities on the casimir effect.
You don't need to "blast" the cavity through space to be able to say that "It is accelerating" It already is accelerating right here on earth, but to small effect.
Everything here is dependent on Rest Mass and Inertial Mass being different under ideal conditions.

Next observation and impossible thing to believe:
Looking at casimir forces, mode exclusion and that whole mess again, I realized that I incorrectly assumed that ALL modes of ALL frequencies were being excluded within the enclosed bell of the emdrive, but that is way incorrect. Only energies allowed by the plasma frequency of the walls of the bell are excluded. Any wall penetrating particles and their infinite modes are NOT excluded by the boundary conditions. So that narrows the playing field of casimir energies to within a band X wide.

Lastly putting all this junk above together, I arrived at the conclusion, that the non symmetric shape of the bell of the emdrive in the length direction is the absolute key here, any chirality in the system is key in the direction of desired thrust, be it in the dielectric's molecules is key. So whatever frequency you're exciting the emdrive at, in this case mhz which is (we're assuming mostly an effect within the dielectric) there MUST be spacial asymmetry in the system's design, in order for it to work without violating conservation of momentum. This applies to any reactionless design. I bet if Woodward put his "symmetrically shaped in the direction of desired thrust" devices in a conical faraday cage, it probably would work.

There is a loose end here. The cannae. I asserted its pill box didn't matter based on the rf analysis in nasa paper and lack of "bell" shape. There is a bell shape but extremely flat where the tube meets the pillbox but it seems negligible. Maybe it is more asymmetric than I can see from the photos. I still haven't looked at the chirality of PTFE, that remains open.

The above logic applies to reactionless theories. Those ones relating to wimps and actually expelling particles out the back don't need such treatment. Only the ones where the plasma frequency of the photons inside the thing, keep the particles confined inside.

Also note how the Rindler horizon keeps moving closer to the particle/ship as it accelerates. Spacial asymmetry again, along the vector of motion. Just like SR. This works at all levels.

And finally, given the (probably flaw logic) above, they emdrive doesn't violate conservation of momentum. The particles inside have a momentum on a gradient.
Another way to think of the inside of the emdrive cavity is to picture it as its own little universe with a slightly modified space manifold, such that there is an asymmetry in parity.
And they really want to equalize, so the thing moves to compensate. Just like McCulloch said.
Boom!
Now I'm going to obsess over the charge component of CP symmetry.
Phew.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 07:41 am
Hot off the presses from our friend over at:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

Wish he'd come and talk with us. Thanks for this.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 07:48 am
Lurker and former engineer here making first post.  I'm intrigued by the theoretical outlays here, but wondering how many among us are potential DIY experimentalists?  I believe that sufficient information is now accessible to the public to independently replicate and confirm this technology widely.  I envision something along the lines of the DIY drone developers and their enthusiasm for advancing that field, with a rapid feedback loop and dispersion of information.

For starters, here is the latest published patent application:
http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=20130206&CC=GB&NR=2493361A&KC=A (http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=20130206&CC=GB&NR=2493361A&KC=A)

YBCO superconducting film to line the inner cavity:
http://www.mtixtl.com/YBCO100nm-film-SrTiO3-101005.aspx (http://www.mtixtl.com/YBCO100nm-film-SrTiO3-101005.aspx)

3GHz+ signal generators:
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR5.TRC1.A0.H0.X3ghz+signal+generator&_nkw=3ghz+signal+generator&_sacat=0 (http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR5.TRC1.A0.H0.X3ghz+signal+generator&_nkw=3ghz+signal+generator&_sacat=0)

Microwave power amplifiers:
http://www.ebay.com/sch/i.html?_odkw=microwave+signal+amplifier&_from=R40|R40|R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xmicrowave+power+amplifier&_nkw=microwave+power+amplifier&_sacat=0 (http://www.ebay.com/sch/i.html?_odkw=microwave+signal+amplifier&_from=R40|R40|R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xmicrowave+power+amplifier&_nkw=microwave+power+amplifier&_sacat=0)

The architectural design, materials, and concepts are described in a fairly straight-forward manner in the patent publication.  YBCO film is superconducting above liquid nitrogen boiling point.  I estimate that an experiment could be put together for less than $2000 of parts.  Of course, the requisite time and knowledge for carrying it out would need to be conducted, probably with no compensation.  Who among us are willing and able?  Is there a Steve Jobs of propellentless devices among these ranks?  My thought is that to advance this tech quickly, technically capable and independent people, not beholden too much to dogma or larger institutions, are going to have to run with it and spread it as far and wide as possible.

Trip to Home Depot in order? Like it.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/06/2014 07:51 am
Quote
.../...
Would be dark matter powered dark matter jet rocket. Call that a "dark matter ramjet". Unless anyone can point me to previous publication or grant, I hereby take precedence on that concept  8)

An SF author, Mike Brotherton, beat you to it in 2008.  His 'dark drive,' a sort of 'dark matter bussard ramjet,' was the drive for his starships in 'Spider Star.'  Worth noting: before writing SF, he had a PHD in Astronomy, held a research position at 'Lawrence Livermore National Laboratory' (whatever that is:) ) and Kitt Peak National Observatory.  Seems to be a bit of an X-Ray expert.  However, the description of his 'dark drive' was superficial.

Amazing, but not that surprising given the span of concepts in SF. Well then I must abandon claim on precedence. Even if superficial description, seeing that from someone with such background is indicative that it wasn't that far fetched... and also that it is in the air of the time (dans l'air du temps).
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 08:08 am
http://arxiv.org/pdf/1302.2775v1.pdf

This paper, needs accelerated peer review.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/06/2014 08:37 am
Also (too lazy to search) it was made mention to AC...

I thought it was all AC.  Where's the DC coming from?


From this post :
4)  Of course not.  Sonny would never agree to test one of Woodward's designs.​  All of the ZPFers believe they are in competition with M-E physics.  Despite Sonny has had MLT's on the balance at Eagle, he would NEVER run them with AC the way they were designed.  The QVF model states these ought to produce thrust when driven with DC, and that is all he checked.  IIUC, he got a null result except for the switching transients which ought to produce thrust according to M-E theory.
So "White DC vs Woodward AC" if I get it. This DC wasn't clear, indeed, and I wanted to ask before... my assumption is that "DC" is stationary RF signal (not DC strictly speaking, more like RF AC at constant amplitude) and "AC" would be some kind of modulation (amplitude ?) or transient of the RF signal. What are the modulation characteristic from this Woodward's camp AC, amplitude, frequency, shape ? Anyone ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 08:47 am
Also (too lazy to search) it was made mention to AC...

I thought it was all AC.  Where's the DC coming from?


From this post :
4)  Of course not.  Sonny would never agree to test one of Woodward's designs.​  All of the ZPFers believe they are in competition with M-E physics.  Despite Sonny has had MLT's on the balance at Eagle, he would NEVER run them with AC the way they were designed.  The QVF model states these ought to produce thrust when driven with DC, and that is all he checked.  IIUC, he got a null result except for the switching transients which ought to produce thrust according to M-E theory.
So "White DC vs Woodward AC" if I get it. This DC wasn't clear, indeed, and I wanted to ask before... my assumption is that "DC" is stationary RF signal (not DC strictly speaking, more like RF AC at constant amplitude) and "AC" would be some kind of modulation (amplitude ?) or transient of the RF signal. What are the modulation characteristic from this Woodward's camp AC, amplitude, frequency, shape ? Anyone ?
My long post above puts M-E'ers and ZPF'ers on equal footing.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 08:51 am
3 words. RC time constant. DC works too.

You charge the cap then discharge the cap. Do it fast and you have an oscillator and it becomes RLC.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/06/2014 09:16 am
Now with a very very scarce medium, the amount of mass/s that can be swallowed by the thruster is so weak that it takes very high ejection speeds to get a thrust level of any significance. When the scarcity of the medium implies relativistic ejection velocities to get interesting thrust, then the fact need [my edit?] to use a medium mass at all becomes irrelevant because you put more energy as kinetic energy than the energy equivalence of harvested mass : if you have that much onboard energy to spend on kinetic energy of the jet, then just creating the rest mass (from energy) of what you are ejecting becomes a negligible term. You are almost as good with a photon rocket and ignoring the medium.

Having had a propeller beanie as a kid, I hang on to that concept concept.  Thanking you again, I continue:.

If it is to be a ramjet, then the intake has to be physically very large.  You can't make it out of matter, you'd have to somehow project a field to harvest the DM as you move thru it, and maybe condense it.  You'd have to start the ramjet going somehow (boom boom Orion?), and discard that stage when the ramjet starts working.

Anyhow, it would not be pushing on the quantum field, and it would have a tailpipe.  I'm thinking you can't suck it up, you have to move thru it.

I'm trying to visualize what a useful spacecraft might look like. Which may be uncomfortably close to speculating about benign wormholes, but hey.

Nearest concept is Bussard ramjet. Since DM appears near impossible to harvest at least at parts per 10^15 within a device, net fishing DM on large spans with fields only is very speculative. You don't necessarily have to move through it as most likely it's already moving through you. Depending on what centre of mass the DM is orbiting, it's speed can't be higher than equivalent escape velocity (40 km/s for yet to be proven solar system bound DM, 500 km/s for "proven" galaxy bound DM, that is at below 1GeV/cm^3) and it is likely in the same ballpark. That is, galactic DM would be in a few 10s or 100s km/s relative to sun, but this is unknown for sure.
The faster you get above this characteristic speed, the more dark mass flow you can swallow, but also the more energy it takes to push back even faster. So the limit of speed is given by some efficiency term, basically how much incoming/harvested mass can be converted to energy. I would say, assuming it's possible at all to "burn" DM mass into energy, a few % of c, but with unlimited delta V (since feeding on the way).

But the problem is the density that is so little that indeed you have to get to a few % of c before mass flow is significant enough to get decent thrust. In this sense this is like a usual ramjet, needs some initial velocity. Compared to Bussard ramjet, mm, interstellar medium (http://en.wikipedia.org/wiki/Interstellar_medium) would be like between 10^-4 (hot diffuse regions) and 10^6 er... er, let's say proton per cm^3. A proton is circa 1GeV, so you compare  10^-4 < 1 < 10^6

To travel through hot diffuse regions, a 100% (or even 1%) harvesting DM ramjet could be better than a Bussard ramjet. Assuming we know how to field capture DM on large spans, that we know how to burn DM. With Bussard ramjet at least we have a slight idea this can be done and how. For DM we have no idea this can be done, and how is left to SF.

Quote
All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.

Riffing on the spacecraft scale for a sec:  Those tubes would be kilometers in diameter? no?

To be clear : this rectifier effect hypothesis had nothing to do with DM, was about RF AC -> DC conversion that could classically explain the results as some DC induced current loops pushing on the damping magnets.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 09:31 am
Just want to add that the emdrive and the METS function on the same principle. METS get it wrong by not enclosing the oscillator within the cone shape. The dielectric in the emdrive acts as the oscillator, excited by the microwaves fired into it.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 09:40 am
Quote
Riffing on the spacecraft scale for a sec:  Those tubes would be kilometers in diameter? no?

You're missing the point of the axion approach. The experiments are looking for photons appearing within an oscillating magnetic field by adding energy to theoretical dm axions. These axions were weakly interacting. Until they became photons! Do this within a metal cone and (?if the theories about cosmological derived inertial mass are true) then profit!
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 09:49 am
Quote from: frobnicat

To be clear : this rectifier effect hypothesis had nothing to do with DM, was about RF AC -> DC conversion that could classically explain the results as some DC induced current loops pushing on the damping magnets.

Yeah those current loops could influence the damper by virtue of charge opposition, if the thing wasn't grounded properly, and if there wasn't a feedback loop built into the damper. I don't know if either of those things is true. There really isn't enough information to make any further assumptions about this kind of stuff available from the 21 page paper. We're speculating.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/06/2014 09:51 am
Yes, long wavelength interaction w/ a condensate of bosons acts like a phonon generation.

It's in here: http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

My head hertz.

Somebody call NDT!


So anyway, what that all means is: if the cloud of dark matter is composed of axions AND if they have formed (as was in some axion paper back there) a Bose-Einstein condensate, one does not need enough energy to create axions, just enough to raise the state of some.  If you do this the exitation propagates like a "phonon" in the condensate, which is a momentum transfer against the entire condensate (ie the "ocean to push against)

Highly speculative, who wants to try a calculation ?

mm, to "raise the state of some" naturally occurring DM is still limited by the very low density overall. A condensate could be useful, compared to a non self interacting medium, as there is some "aerodynamics", pressure waves... What would be the "speed of sound" in such a condensate, if such concept has any meaning for a Bose-Einstein condensate ? If it is much higher than the average speed of the medium then yes it could be like er, you know, air augmented double flow in jet engine, better thrust than what is accelerated primarily. Maybe a factor of 10 or 100 ? I don't see much above that, unless a condensate is like a "rigid plate" and push at one place is spread over a much large volume ?

Personally, from my little calculations above, and given the likely <<1 coupling factors with DM I would still discard any explanation involving naturally occurring DM in a classical framework : not enough to account for even the weakest results at Eagle (and way off the compact drives mN better results from elsewhere).
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 10:12 am
Yes, long wavelength interaction w/ a condensate of bosons acts like a phonon generation.

It's in here: http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

My head hertz.

Somebody call NDT!


So anyway, what that all means is: if the cloud of dark matter is composed of axions AND if they have formed (as was in some axion paper back there) a Bose-Einstein condensate, one does not need enough energy to create axions, just enough to raise the state of some.  If you do this the exitation propagates like a "phonon" in the condensate, which is a momentum transfer against the entire condensate (ie the "ocean to push against)

Highly speculative, who wants to try a calculation ?

mm, to "raise the state of some" naturally occurring DM is still limited by the very low density overall. A condensate could be useful, compared to a non self interacting medium, as there is some "aerodynamics", pressure waves... What would be the "speed of sound" in such a condensate, if such concept has any meaning for a Bose-Einstein condensate ? If it is much higher than the average speed of the medium then yes it could be like er, you know, air augmented double flow in jet engine, better thrust than what is accelerated primarily. Maybe a factor of 10 or 100 ? I don't see much above that, unless a condensate is like a "rigid plate" and push at one place is spread over a much large volume ?

Personally, from my little calculations above, and given the likely <<1 coupling factors with DM I would still discard any explanation involving naturally occurring DM in a classical framework : not enough to account for even the weakest results at Eagle (and way off the compact drives mN better results from elsewhere).

Yes I agree. So by cooling the cavity to near absolute zero, I believe the efficiency can be improved drastically. Give me a few and I can back that assertion up. I already found proof of this somewhere and it is right on the tip of my tongue.

Edit:

Seems to me lowering the ground state of energy in the cavity by whatever means, be it lowering the temperature is advantageous. This is getting way too complex to make any clear predictions based of very little due to the complex interaction of temperature and geometry on casimir effects.

Here's some info I found:
http://arxiv.org/pdf/hep-th/0503100v2.pdf
http://www.nature.com/nphys/journal/v7/n3/full/nphys1909.html
http://arxiv.org/pdf/quant-ph/0511037v2.pdf
http://dspace.mit.edu/handle/1721.1/58477
Title: Re: EM Drive Developments
Post by: frobnicat on 10/06/2014 10:21 am
Quote from: frobnicat

To be clear : this rectifier effect hypothesis had nothing to do with DM, was about RF AC -> DC conversion that could classically explain the results as some DC induced current loops pushing on the damping magnets.

Yeah those current loops could influence the damper by virtue of charge opposition, if the thing wasn't grounded properly, and if there wasn't a feedback loop built into the damper. I don't know if either of those things is true. There really isn't enough information to make any further assumptions about this kind of stuff available from the 21 page paper. We're speculating.
Charge opposition ?
Trying to clarify : see attached picture (?)

Yes we are speculating. Just dropping another strong magnet in the chamber, seeing the difference in measured result (when subtracting the new different DC power stray force) would be enough to tell if the permanent B field plays a role at all in what is reported as the real thrust...

edit :
the assumption here is that the strong E fields (because high Q) can make some kind of tunnel diode effect somewhere around the dielectric (it was even considered electric breaking so...) The drawing is simplified, there could be a lot of loops, or a lot of small rectifier effects here and there in a bigger loop, there could be a (not perfectly conducting) path parallel to such diode(s) lowering the magnitude but not shunting it to 0...
This hypothesis needs around 1 or 10 mA DC component on a significant span (macroscopic, not microscopic) to work at the needed magnitude  (from F = deltaB I length, deltaB is given by the gradient of permanent B at the loop's span, forward/backward parts of current). Don't know if it holds water at all, was just an idea.
What would be the AC intensities bouncing the waves off the cavity walls, at skin depth ? If this is >>1mA because high Q pumps up the magnitudes, then a small rectifier effect could make enough of DC from this AC.

@Mulletron : I understand a dielectric is an isolator (perfect ?) and can't accommodate a DC current going through its bulk volume, but what about its boundary ? What if its boundary is near (encased) in conducting cavity ? Sorry, this is very vague intuitions...
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 10:21 am
With the aide of Mach and his seminal generalized interpretation of the origin of inertial mass, which informed Einstein and was elaborated on by many in parallel; I am hopeful we have graduated into a new and better world. The problem of EMdrive appears to me as no longer a question of a theoretical problem and has become an engineering problem.


I am confident in that there is such a wide body of knowledge from many great thinkers supporting an extrinsically derived value for inertial mass. It doesn't even matter who is right, as long as one of them is.

HOPEFULLY the EMdrive passes further tests of replication.

The attached pic is my rendering of how I picture the most optimal shape of the apparatus informed by the (difficult for me to grasp so I might have got it wrong) casimir interactions inside/outside 3d shapes, combined with the light cone. So the cone is 45 degrees, the dimensions are wrt dominant TE/TM modes discussed back in the thread, the end is a half sphere instead of flat for a reason; as two casimir spheres attract; the other sphere being the Rindler Horizon. The cone I interpreted as being less attractive with the Hubble sphere than the sphere shape, but internally repulsive to itself. The net effect outside is an inertial bias toward the half sphere end of the device. The net effect inside is the opposite. ..More inertia on left sphere side, gives rise to an energy bias inside the system. Particles moving from skinny to fat end gain energy, unbalance occurs, the system moves toward the pointy end. I hope I got all that right. This is all informed by many other people's work. This is my interpretation.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 12:04 pm
With the aide of Mach and his seminal generalized interpretation of the origin of inertial mass, which informed Einstein ...

<<With the aide of Mach >> (Ernst)

perhaps

"With the aide of March" (Paul)

we can get the damping value (N s/m) for the NASA Eagleworks inverted torsional pendulum experiments. 
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:11 pm
With the aide of Mach and his seminal generalized interpretation of the origin of inertial mass, which informed Einstein ...

<<With the aide of Mach >> (Ernst)

perhaps

"With the aide of March" (Paul)

we can get the damping value (N s/m) for the NASA Eagleworks inverted torsional pendulum experiments.

As long as we're getting picky about individual letters, are we talking about someone who helps another, or are we talking about "tribute paid by a vassal to his lord"? (Per definition 4, Webster's seventh, New Collegiate)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:14 pm
I estimate that an experiment could be put together for less than $2000 of parts.

Looks like you're batting a thousand on the "likes", but $2K is hopelessly optimistic.  Last time I looked, I needed $4K for a decent workstation.  Still, thanks for posting.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:17 pm
... i was like message boy ...

You still don't get it, do ya?  Take a weekend trip to AZ, and get a sense of Yuma.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:18 pm
John Fornaro had mentioned something about black hole drives

It's true that I drive a '92 black 240 wagon.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:20 pm
its easy

No, its [sic] not.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:24 pm
I find it hard to believe he has confused mass energy [equivalent rest mass energy, I believe is what he meant]  within the atom with energies of covalent bonds.

They're the same thing.  They both gravitate and have inertia.  The scale is wildly different, but that's immaterial.

From a grammatical standpoint, it's [note spelling] all material.

However, while it may indeed be factual that equivalent rest mass energy and equivalent covalent bond energy may be indifferentiable in numerical principle, that the magnitudes of the energies involved are so divergent; they are most definitely not "immaterial".
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:31 pm
...Remember that mass is constrained over space and energy is constrained over time! ...

The particles inside have a momentum on a gradient.

Another way to think of the inside of the emdrive cavity is to picture it as its own little universe with a slightly modified space manifold, such that there is an asymmetry in parity.

And they really want to equalize, so the thing moves to compensate. Just like McCulloch said.

Boom!

Now I'm going to obsess over the charge component of CP symmetry.

Phew.

It's own little universe?  Are you sure?  How can that be?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 12:34 pm
I find it hard to believe he has confused mass energy [equivalent rest mass energy, I believe is what he meant]  within the atom with energies of covalent bonds.

They're the same thing.  They both gravitate and have inertia.  The scale is wildly different, but that's immaterial.

From a grammatical standpoint, it's [note spelling] all material.

However, while it may indeed be factual that equivalent rest mass energy and equivalent covalent bond energy may be indifferentiable in numerical principle, that the magnitudes of the energies involved are so divergent; they are most definitely not "immaterial".

http://en.wikipedia.org/wiki/Nordtvedt_effect

They are not the same thing in our universe. They are symmetric. This is why electrons instantaneously jump from between energy levels. They tunnel and this is KEY.


Edit:
An interesting implication of this is that there is only one electron in the universe. More on that later. My brain is overheating.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 12:59 pm
You know what? I think I'm wrong on the Nordtvedt effect now. It is referring to gravitational self energy. I must make sure I use very precise terms from now on. This is not the same component of self energy as the self energy of covalent bonds. That is something I've never heard of.

Mea culpa

Your argument still stands, but I disagree, without salient evidents, so far......

I think this means that the Nordtvedt effect doesn't apply to the Woodward effect either. He isn't adding or subtracting GRAVITATIONAL self energies to anything. He's playing in the realm of electrodynamics.

I need to find X effect, which would be observed if the covalent self-energy of a body contributed to its rest mass but not its inertial mass.

I'm also assuming it is safe to say that Gravitational Mass can never be separated from Rest Mass, that they are invariant. I think it is safe to say that indeed gravitational self energy does indeed contribute to inertial mass, and that may not be the only thing or the only way which in which mechanisms contributes to inertial mass, in our universe, either way gravitational self energy DOES. Verified by experiment. Modify the universe, say like in the emdrive's conical cavity. The rules are different. I put a 3d model and explanation on the last page demonstrating this.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 12:59 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

Quote from: McCulloch's paper
Assuming a large acceleration, ie: a terrestrial one, we can neglect this MiHsC term...

What is a "terrestrial acceleration"?

I would like to read this:

Gine, J., 2012. The holographic scenario, the modified inertia and the dynamics
of the universe. Mod. Phys. Lett. A. Vol. 27, No. 34, 1250208.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 01:02 pm
3 words. RC time constant. DC works too.

You charge the cap then discharge the cap. Do it fast and you have an oscillator and it becomes RLC.

I thought that was just on and off with the current always flowing in the same direction.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 01:15 pm
3 words. RC time constant. DC works too.

You charge the cap then discharge the cap. Do it fast and you have an oscillator and it becomes RLC.

I thought that was just on and off with the current always flowing in the same direction.

Current flows in on charge, and out on discharge. Opposite. It happens on a curve. You can plot it by the equations of capacitive reactance , inductive reactance, or together combined with resistance, you get impedance. Both are calculated differently depending if it is a series or parallel circuit.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 01:19 pm
I would say, assuming it's possible at all to "burn" DM mass into energy, a few % of c, but with unlimited delta V (since feeding on the way)

At least I get the Bussard ramjet idea.  More or less, you don't have to carry your "oxidiser", but you do have to carry your "fuel".  I think.

Quote from: frobnicat
But the problem is the density that is so little that indeed you have to get to a few % of c before mass flow is significant enough to get decent thrust. In this sense this is like a usual ramjet, needs some initial velocity.

Which is why I added the boom-boom Orion stage.  Fission propulsion has been more or less worked out in the 50's and 60's (probably by 1953 no doubt), but I don't think fusion propulsion has been worked out to the same extent.

The oracle:

http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29

Quote from: frobnicat
Assuming we know how to field capture DM on large spans, that we know how to burn DM.

Thanks for the better terms: Field capture of DM on large spans. And net fishing DM on large spans with fields.

Quote from: Frobnicat & Mulletron
To be clear : this rectifier effect hypothesis had nothing to do with DM...

No, I got that.  I'm just designing that spacecraft which uses the "rectifier effect hypothesis".  While you don't need an evacuated glass container for the "tube", there would be a lot of mass, and a large size associated with the spacecraft.

Riffing off of caffeine at the moment, I'd guess that you'd need several families of VonNeuman devices, spread out over a large area, fed material some how, and powered, somehow, in order to build the spacecraft.

Which, to my mind, gets back to wondering briefly, on the BOE, how big would that spacecraft have to be?  Both the DM ramjet and the rectifier effect ones.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 01:19 pm
Quote
Riffing on the spacecraft scale for a sec:  Those tubes would be kilometers in diameter? no?

You're missing the point of the axion approach. The experiments are looking for photons appearing within an oscillating magnetic field by adding energy to theoretical dm axions. These axions were weakly interacting. Until they became photons! Do this within a metal cone and (?if the theories about cosmological derived inertial mass are true) then profit!

I admit to glossing over the axion discussion.  I'm a pretty good typist, but you guys are far, far faster readers.  Will rectify mea culpa on that.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 01:27 pm
... i was like message boy ...

You still don't get it, do ya?  Take a weekend trip to AZ, and get a sense of Yuma.

Oh, it took me some time to get this, I was wondering why Yuma ?

3:10 to Yuma film ?  Dry, hottest city? Old people ?

I just got it, you mean to say (to @aceshigh): "and get a sense of humor"  :), with humor pronounced with a Brooklyn accent  :)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 01:28 pm
how I picture the most optimal shape of the apparatus...

Your pic doesn't look like a 45 degree cone, and what are the dimensions?  How about energy going in, and acceleration in the pointy direction?

Solo chiedendo.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 01:30 pm
there is only one electron in the universe

And it's mine!

https://www.youtube.com/watch?v=gr1IA8Vnw0A
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 01:31 pm
how I picture the most optimal shape of the apparatus...

Your pic doesn't look like a 45 degree cone, and what are the dimensions?  How about energy going in, and acceleration in the pointy direction?

Solo chiedendo.

Your pic (  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1266842#msg1266842  ) doesn't look like a 45 degree cone either.  You give me the material, and I'm on a roll today.  Solo dicendo  :)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 01:33 pm
how I picture the most optimal shape of the apparatus...

Your pic doesn't look like a 45 degree cone, and what are the dimensions?  How about energy going in, and acceleration in the pointy direction?

Solo chiedendo.

It is 45 degrees. The dimensions are based on the operating frequency. Do the math. The actual size are irrelevant in this discussion. It is all waveguide theory. The stuff I put up a few pages back about how many half wavelengths across and around the thing. House knowledge. As far as energy going in, me must separate terms here. Energy is in terms of frequency. RF power is a function of photon flux. Flux doesn't affect size of the thing, just the dielectric breakdown and heat/arcing sparking effects.
Title: Re: EM Drive Developments
Post by: MikeMcCulloch on 10/06/2014 01:39 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

Quote from: McCulloch's paper
Assuming a large acceleration, ie: a terrestrial one, we can neglect this MiHsC term...

What is a "terrestrial acceleration"?

I would like to read this:

Gine, J., 2012. The holographic scenario, the modified inertia and the dynamics
of the universe. Mod. Phys. Lett. A. Vol. 27, No. 34, 1250208.

By terrestrial acceleration I meant something typical of a mutual acceleration on Earth, eg: 9.8 m/s^2.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 01:57 pm
...regardless of the dielectric's acoustic geometry, M-E physics cannot explain thrust from a DC signal.  It can explain thrust impulses from switching transients, and AC signals, but not DC.  You've been reading the paper recently so you should be able to tell more easily than I whether the setup meets the criteria to be acting as a MET....

This is very useful information, thank you.  Could you be so kind as to review the following excerpt from the NASA Eagleworks report and let us know your opinion of whether "M-E physics" can explain thrust from the following signal:

p.8 <<During testing, the Test Engineer controls the RF frequency generation via a 0-to-28 volts dc power input to a voltage-controlled oscillator (VCO). The VCO RF signal output is passed to a variable voltage attenuator (VVA), the output of which is controlled by the Test Engineer via a 0-to-17 volts dc power input. Based upon the VVA output, the amplifier will output up to approximately 28 watts. Amplifier output passes to a dual-directional coupler (DDC), which allows forward and reflected power measurements to be obtained as the power is simultaneously passed to the test article input port. The Test Engineer monitors forward and reflected power and adjusts the input frequency to obtain the desired combination of cavity frequency and power delivery to the cavity.>>
It's DC, so M-E theory cannot explain constant thrust from such a setup unless there is significant ripple in the signal.  There's no data about ripple here.  M-E theory could explain thrust form switching transients here.  Did this experiment generate constant thrust or thrust impulses during switching?
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 02:07 pm
...regardless of the dielectric's acoustic geometry, M-E physics cannot explain thrust from a DC signal.  It can explain thrust impulses from switching transients, and AC signals, but not DC.  You've been reading the paper recently so you should be able to tell more easily than I whether the setup meets the criteria to be acting as a MET....

This is very useful information, thank you.  Could you be so kind as to review the following excerpt from the NASA Eagleworks report and let us know your opinion of whether "M-E physics" can explain thrust from the following signal:

p.8 <<During testing, the Test Engineer controls the RF frequency generation via a 0-to-28 volts dc power input to a voltage-controlled oscillator (VCO). The VCO RF signal output is passed to a variable voltage attenuator (VVA), the output of which is controlled by the Test Engineer via a 0-to-17 volts dc power input. Based upon the VVA output, the amplifier will output up to approximately 28 watts. Amplifier output passes to a dual-directional coupler (DDC), which allows forward and reflected power measurements to be obtained as the power is simultaneously passed to the test article input port. The Test Engineer monitors forward and reflected power and adjusts the input frequency to obtain the desired combination of cavity frequency and power delivery to the cavity.>>
It's DC, so M-E theory cannot explain constant thrust from such a setup unless there is significant ripple in the signal.  There's no data about ripple here.  M-E theory could explain thrust form switching transients here.  Did this experiment generate constant thrust or thrust impulses during switching?

Thank you Ron, your answer is very useful information to further understand this.

Concerning your question <<Did this experiment generate constant thrust >> according to Eagleworks analysis the tested EM drive generated a constant thrust force.

My analysis of the Eagleworks data is that at this point in time it is not clear whether what they measured was indeed due to a constant thrust force from the EM drive they tested, or whether it was an artifact.   For example their own data (p.18 of their report, see attached data: the last two rows) has examples showing that increasing the power input by a factor of 6 did not increase the thrust force at all (the thrust force actually decreased by 10% when the power was increased from 2.6 watts to 16.7 watts). This is very concerning regarding Eagleworks using the specific force defined as the ratio of the thrust force divided by the power input as a scaling measure for predicting future scale up of these drives.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 02:16 pm
Figure 22 on page 18 worries me. That upward slope over 30 seconds while the rf was on and a slow fade after rf was off says heat was the cause. 70uN thrust/60uN heat.

Bingo!

Yes, that's the coupling between the magnetic damping and the field from the power cable I have been writing about.  Notice that the coupling is HUGE.  By their own admission the "null" signal is 25% of the good signal !!!!!

And they subtract the coupling "null" signal as if the problem would be linear.  They do not take into account any nonlinearities.  There is no finite element (No COMSOL) analysis of the magnetic coupling problem

Yeah all the modes show some heat or something else too.

Yes, but it looks like there is something real exciting the system.  The only argument I see now for an artifact would be that the magnetic damping is interacting with the power cable AND the dielectric effect. Because they measure no thrust without the dielectric.  And because flipping the orientation of the dielectric flips the direction of the thrust.  So if it is an artifact one would have to explain it as a result of the magnetic fields (from the damping and the power cable) interacting with the dielectric.
Can you explain this bolded above in further detail?
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 02:20 pm
Figure 22 on page 18 worries me. That upward slope over 30 seconds while the rf was on and a slow fade after rf was off says heat was the cause. 70uN thrust/60uN heat.

Bingo!

Yes, that's the coupling between the magnetic damping and the field from the power cable I have been writing about.  Notice that the coupling is HUGE.  By their own admission the "null" signal is 25% of the good signal !!!!!

And they subtract the coupling "null" signal as if the problem would be linear.  They do not take into account any nonlinearities.  There is no finite element (No COMSOL) analysis of the magnetic coupling problem

Yeah all the modes show some heat or something else too.

Yes, but it looks like there is something real exciting the system.  The only argument I see now for an artifact would be that the magnetic damping is interacting with the power cable AND the dielectric effect. Because they measure no thrust without the dielectric.  And because flipping the orientation of the dielectric flips the direction of the thrust.  So if it is an artifact one would have to explain it as a result of the magnetic fields (from the damping and the power cable) interacting with the dielectric.
Can you explain this bolded above in further detail?
A better (but longer) worded statement is that rotating the tested article by 180 degrees around a vertical axis, flipped the direction of the measured thrust force so that it now occurred in the opposite direction (resulting in approximately the same absolute magnitude but with opposite sign).  Just like rotating a car heading North (in forward drive) by 180 degrees around the vertical axis will make it now head South (when operating in forward drive).
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 02:25 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

Quote from: McCulloch's paper
Assuming a large acceleration, ie: a terrestrial one, we can neglect this MiHsC term...

What is a "terrestrial acceleration"?

I would like to read this:

Gine, J., 2012. The holographic scenario, the modified inertia and the dynamics
of the universe. Mod. Phys. Lett. A. Vol. 27, No. 34, 1250208.

By terrestrial acceleration I meant something typical of a mutual acceleration on Earth, eg: 9.8 m/s^2.

A very warm welcome to this forum, Prof. McCulloch  :)

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 02:26 pm
Okay, so they flipped the entire test article.  I thought you were saying they had reoriented the dielectric inside the test article.

Flipping the test article does work for isolating any coupling from the power leads, which you had previously been concerned about.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 02:27 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

Quote from: McCulloch's paper
Assuming a large acceleration, ie: a terrestrial one, we can neglect this MiHsC term...

What is a "terrestrial acceleration"?

I would like to read this:

Gine, J., 2012. The holographic scenario, the modified inertia and the dynamics
of the universe. Mod. Phys. Lett. A. Vol. 27, No. 34, 1250208.

By terrestrial acceleration I meant something typical of a mutual acceleration on Earth, eg: 9.8 m/s^2.

Oh snap! Welcome to the forum. Please give us your knowledge and help us tear apart our crazy ideas so that we can find order here.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 02:29 pm
Okay, so they flipped the entire test article.  I thought you were saying they had reoriented the dielectric inside the test article.

Flipping the test article does work for isolating any coupling from the power leads, which you had previously been concerned about.

We had another discussion a few pages back on the precision of our language and it was decided that the whole test article was flipped, not the dielectric. This is the language in the paper. And the pics show it flipped anyway.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 02:34 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

Quote from: McCulloch's paper
Assuming a large acceleration, ie: a terrestrial one, we can neglect this MiHsC term...

What is a "terrestrial acceleration"?

I would like to read this:

Gine, J., 2012. The holographic scenario, the modified inertia and the dynamics
of the universe. Mod. Phys. Lett. A. Vol. 27, No. 34, 1250208.

By terrestrial acceleration I meant something typical of a mutual acceleration on Earth, eg: 9.8 m/s^2.

A very warm welcome to this forum, Prof. McCulloch  :)

Prof. McCulloch, your estimations of the Shawyer and NASA Eagleworks results are the ones that come closest to the experimental results.  What is particularly interesting is that your estimations do so with a bare minimum of parameters: just using the dimensions, Q factor, power input, and frequency.
Title: Re: EM Drive Developments
Post by: aceshigh on 10/06/2014 02:35 pm
... i was like message boy ...

You still don't get it, do ya?  Take a weekend trip to AZ, and get a sense of Yuma.

no, I dont get it, nor do I get this last message. Btw, I was not re-complaining about posting stuff from here there, and post from there here, I was merely pointing out that I had already made it public that I was posting at Talk Polywell forums.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 02:38 pm
there is only one electron in the universe

And it's mine!

https://www.youtube.com/watch?v=gr1IA8Vnw0A

The Great Feynman would say that.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 02:40 pm
how I picture the most optimal shape of the apparatus...

Your pic doesn't look like a 45 degree cone, and what are the dimensions?  How about energy going in, and acceleration in the pointy direction?

Solo chiedendo.

Your pic (  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1266842#msg1266842  ) doesn't look like a 45 degree cone either.  You give me the material, and I'm on a roll today.  Solo dicendo  :)

There is no way to say that with an arbitrary perspective, nevertheless. The design intent is a 45 degree light cone. Looking for cad errors isn't the important thing here.
Title: Re: EM Drive Developments
Post by: aero on 10/06/2014 02:43 pm
Guys, hold on here. While I was thinking of making a post, ordering my thoughts so to speak, five new posts appeared. I closed my browser, opened and read the posts, then started to reply but there are more new posts.

I am going to wait until some of you get to work, then I'll post on topic.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 02:53 pm
how I picture the most optimal shape of the apparatus...

Your pic doesn't look like a 45 degree cone, and what are the dimensions?  How about energy going in, and acceleration in the pointy direction?

Solo chiedendo.

Your pic (  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1266842#msg1266842  ) doesn't look like a 45 degree cone either.  You give me the material, and I'm on a roll today.  Solo dicendo  :)

There is no way to say that with an arbitrary perspective, nevertheless. The design intent is a 45 degree light cone. Looking for cad errors isn't the important thing here.

Don't get me wrong.  I'm not "looking" for CAD errors.  And I get that about perspective.  Still, it looked like a 60 degree cone. 

As you were.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 03:26 pm
how I picture the most optimal shape of the apparatus...

Your pic doesn't look like a 45 degree cone, and what are the dimensions?  How about energy going in, and acceleration in the pointy direction?

Solo chiedendo.

Your pic (  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1266842#msg1266842  ) doesn't look like a 45 degree cone either.  You give me the material, and I'm on a roll today.  Solo dicendo  :)

There is no way to say that with an arbitrary perspective, nevertheless. The design intent is a 45 degree light cone. Looking for cad errors isn't the important thing here.

Don't get me wrong.  I'm not "looking" for CD errors.  And I get that about perspective.  Still, it looked like a 60 degree cone. 

As you were.

Ok laptop screen is widescreen but the pic is square, jeez. There is a difference between qualitative and quantitative. It was a quick and dirty pic to show a concept. The quantities describing it are verbose in the text. Anyway I hope I got the underlying interpretation wrong, so I can fix it and learn something new, further making progress to a real path to the stars.

Edit: Okay I made a cad error. I rushed it. I done better this time.
I know why I screwed up the drawing. It was because I amateurishly started with the radius of the circle. I should have started with the most fundamental thing in physics, which is the speed of light, which informs the light cone, then derived the radius of the circle. I didn't run a real angular dimension check in cad to verify correctness and ended up with a stretched out test article. Causality flows from the pointy end to the round end!

Edit: I even screwed it up again. I haven't touched autocad in a very long time and even simple tasks apparently are hard now for me. Pic replaced with correct one.

Given a sphere filled with homogenous radiation which is pushing against everything else equally and with the absence of other forces, another smaller sphere inserted inside the larger sphere would not be biased in any particular direction. Now replace the internal sphere with the cone with half sphere base, I predict the cone would be biased toward the half spherical end. The surface area of the half sphere with and arbitrarily picked r=1.5 is 14.14, while the surface area of the cone with height=3.695 is 18.79. In terms of classical mechanics, the imbalance would create a bias toward the round end. Casimir forces are more complex than this, so this is a rough model.

Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 03:31 pm
Okay, so they flipped the entire test article.  I thought you were saying they had reoriented the dielectric inside the test article.

Flipping the test article does work for isolating any coupling from the power leads, which you had previously been concerned about.
The coupling is very concerning because the Eagleworks report admits that the effect of the magnetic dampening interacting with the field of the power cable gives a signal of about  ~25% of their measurements.  It affects their baseline in an erratic manner and they try to subtract its effect as a linear influence (therefore not taking into account any nonlinearity).  Since the Eagleworks data is also very nonlinear (for example the case where increasing the input power by a factor or 6 results in a decrease of the measured thrust of 10%) it is useful to further clarify this coupling effect.

Now, the magnetic damper is located downstream in the vacuum chamber, behind the inverted pendulum beam, while the tested article is in front, upstream in the vacuum chamber.

QUESTION: Ron, (if I understood correctly your statement <<Flipping the test article does work for isolating any coupling from the power leads>>), why do you think that flipping the test article would eliminate the effect of the magnetic damper with the power lead and the tested drive?  Wouldn't be the case that if there is coupling between the magnetic field from the damper, the power cable, and the electromagnetic fields in the tested article (both magnetic and electric fields inside it), that flipping the test article would still produce an artifact, now in the opposite direction?  (as also suggested in an example drawing by @frobnicat a couple of pages back)?
Title: Re: EM Drive Developments
Post by: DIYFAN on 10/06/2014 04:06 pm
Lurker and former engineer here making first post.  I'm intrigued by the theoretical outlays here, but wondering how many among us are potential DIY experimentalists?  I believe that sufficient information is now accessible to the public to independently replicate and confirm this technology widely.  I envision something along the lines of the DIY drone developers and their enthusiasm for advancing that field, with a rapid feedback loop and dispersion of information.

For starters, here is the latest published patent application:
http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=20130206&CC=GB&NR=2493361A&KC=A (http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=20130206&CC=GB&NR=2493361A&KC=A)

YBCO superconducting film to line the inner cavity:
http://www.mtixtl.com/YBCO100nm-film-SrTiO3-101005.aspx (http://www.mtixtl.com/YBCO100nm-film-SrTiO3-101005.aspx)

3GHz+ signal generators:
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR5.TRC1.A0.H0.X3ghz+signal+generator&_nkw=3ghz+signal+generator&_sacat=0 (http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR5.TRC1.A0.H0.X3ghz+signal+generator&_nkw=3ghz+signal+generator&_sacat=0)

Microwave power amplifiers:
http://www.ebay.com/sch/i.html?_odkw=microwave+signal+amplifier&_from=R40|R40|R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xmicrowave+power+amplifier&_nkw=microwave+power+amplifier&_sacat=0 (http://www.ebay.com/sch/i.html?_odkw=microwave+signal+amplifier&_from=R40|R40|R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xmicrowave+power+amplifier&_nkw=microwave+power+amplifier&_sacat=0)

The architectural design, materials, and concepts are described in a fairly straight-forward manner in the patent publication.  YBCO film is superconducting above liquid nitrogen boiling point.  I estimate that an experiment could be put together for less than $2000 of parts.  Of course, the requisite time and knowledge for carrying it out would need to be conducted, probably with no compensation.  Who among us are willing and able?  Is there a Steve Jobs of propellentless devices among these ranks?  My thought is that to advance this tech quickly, technically capable and independent people, not beholden too much to dogma or larger institutions, are going to have to run with it and spread it as far and wide as possible.

Trip to Home Depot in order? Like it.

Hope Depot is a man's best friend.  :)

For the cavity itself, metal 3d printing is now ubiquitous and affordable.

http://gpiprototype.com/services/metal-3d-printing.html
https://www.solidconcepts.com/technologies/direct-metal-laser-sintering-dmls/?gclid=CMCy2rWzmMECFQqCfgod3A4AXw
(and many others)

A simple CAD design and a submission to a 3d printing company can yield a well-formed prototype cavity within 1-2 weeks.  The prototype can be formed of a variety of metals.  The prototype could be tested in a non-superconducting configuration first to get a baseline.  Then, the inner portion of the cavity could be lined with YBCO film, cooled to liquid nitrogen temperatures, and tested in a superconducting configuration.

It even appears that some 3d printers are capable of printing using superconducting materials:
http://www.tamuk.edu/engineering/departments/mien/3D%20Printers/index.html


Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 04:07 pm
why do you think that flipping the test article would eliminate the effect of the magnetic damper with the power lead and the tested drive? 
Paul helped design the Eagle balance based upon lessons learned with Woodward's ARC Lite balance.  That balance was specifically designed so one could physically reorient the thruster without reorienting the power leads to it, so that if they were coupling, that coupling would not also flip--hence isolating the spurious from the actual thrust.  I can only presume Paul kept that protocol.  I haven't seen the detailed explanations of the Eagle balance that have been so public with Woodward's work, but Paul knows the value of that particular practice.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/06/2014 04:24 pm
Taking a shot at an "axion condensate dark matter" energy to force calculation.

So theory and experiment both give a reduction in "sound speed" in a dilute condensate of ~ 10^-6.  So, let's say s = < 300 m/sec, given the assumption that the "axions" "interact" via gravity at c.

Using a rough experimental result of 10W => 50 micronewtons for comparison.

At 300 m/sec, I need to generate 2.5 X 10^22 phonons/sec at a power of 1.5 X 10-2 watts to generate that 50 micronewtons.

So 15 milliwatts out of 10 watts => 0.15%  (pretty high)

Edit +10^22 and phonons not photons
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 04:39 pm
why do you think that flipping the test article would eliminate the effect of the magnetic damper with the power lead and the tested drive? 
Paul helped design the Eagle balance based upon lessons learned with Woodward's ARC Lite balance.  That balance was specifically designed so one could physically reorient the thruster without reorienting the power leads to it, so that if they were coupling, that coupling would not also flip--hence isolating the spurious from the actual thrust.  I can only presume Paul kept that protocol.  I haven't seen the detailed explanations of the Eagle balance that have been so public with Woodward's work, but Paul knows the value of that particular practice.

Thank you.

Concerning <<Paul helped design the Eagle balance based upon lessons learned with Woodward's ARC Lite balance>>

Question: Did Prof. Woodward's "ARC Lite balance" also use magnetic dampening ?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 04:53 pm
Yes, but to a much lesser degree, and as I said, it is easy to isolate with a dummy load.  Woodward's thrusters form a perfect dummy load when the phase angle between the 1w and 2w portions of the signal are moved.  At 90* phase thrust is in one direction, and at 270* the other.  At 0* and 180* there is no thrust expected, so the thruster itself makes a perfect dummy load.

Woodward didn't have any coupling with the magnetic dampener.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 04:59 pm
Yes, but to a much lesser degree, and as I said, it is easy to isolate with a dummy load.  Woodward's thrusters form a perfect dummy load when the phase angle between the 1w and 2w portions of the signal are moved.  At 90* phase thrust is in one direction, and at 270* the other.  At 0* and 180* there is no thrust expected, so the thruster itself makes a perfect dummy load.

Woodward didn't have any coupling with the magnetic dampener.
thanks.

And what specific kind of "Woodward's thruster" was tested by Woodward et.al. with that setup, the MLT or MET type of thruster?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 05:09 pm
Yes, but to a much lesser degree, and as I said, it is easy to isolate with a dummy load.  Woodward's thrusters form a perfect dummy load when the phase angle between the 1w and 2w portions of the signal are moved.  At 90* phase thrust is in one direction, and at 270* the other.  At 0* and 180* there is no thrust expected, so the thruster itself makes a perfect dummy load.

Woodward didn't have any coupling with the magnetic dampener.

Indeed on pages 10, 11, and 14. Dummy loads are mentioned. 10, 11 for Cannae. 14 for Emdrive. I gather that they used pretty darn good controls as experimentalist and this wasn't their first rodeo. They had lessons learned from previous campaigns. I do have issues with the seemingly small number of test campaigns, but I concede that it takes time to setup and run carefully. I have to bring up the fact that dummy loads by their very essence, convert rf to heat. How was the waste heat isolated? If, for instance, the waste heat of the dummy load were contributing to impulse EXACTLY the same as the test article, because the dominant effect was heat radiation, the dummy load null test would be invalid. So where was the dummy load? I can tell you from my own experience that dummy loads get very very hot.

Also, yes you are right, if the rf mode is setup where the standing wave is at minimum E, but max I at the boundary, it would be a dummy load and dump the rf as heat.

http://www.ece.rutgers.edu/~orfanidi/ewa/ch09.pdf

Here is a link with TMI on waveguide theory, and a Navy neets mod. See page 1-26 and on mostly. The whole thing will teach you so much.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 05:21 pm
Yes, but to a much lesser degree, and as I said, it is easy to isolate with a dummy load.  Woodward's thrusters form a perfect dummy load when the phase angle between the 1w and 2w portions of the signal are moved.  At 90* phase thrust is in one direction, and at 270* the other.  At 0* and 180* there is no thrust expected, so the thruster itself makes a perfect dummy load.

Woodward didn't have any coupling with the magnetic dampener.

Indeed on pages 10, 11, and 14. Dummy loads are mentioned. 10, 11 for Cannae. 14 for Emdrive. I gather that they used pretty darn good controls as experimentalist and this wasn't their first rodeo. They had lessons learned from previous campaigns. I do have issues with the seemingly small number of test campaigns, but I concede that it takes time to setup and run carefully. I have to bring up the fact that dummy loads by their very essence, convert rf to heat. How was the waste heat isolated? If, for instance, the waste heat of the dummy load were contributing to impulse EXACTLY the same as the test article, because the dominant effect was heat radiation, the dummy load null test would be invalid. So where was the dummy load? I can tell you from my own experience that dummy loads get very very hot.

Also, yes you are right, if the rf mode is setup where the standing wave is at minimum E, but max I at the boundary, it would be a dummy load and dump the rf as heat.
As way of background to @Mulletron's question, this is the excerpt from the report (p.14):

<<The net force is calculated by accounting for the null force present in the system. Null testing is performed by attaching the RF drive system to a 50 ohm load and running the system at full power. The null force testing indicated that there was an average null force of 9.6 micronewtons present in the as tested configuration. The presence of this null force was a result of the DC power current of 5.6 amps running in the power cable to the RF amplifier from the liquid metal contacts. This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system.>>

and Fig. 20 caption:

<<Figure 20. Null Test on Torsion Pendulum – average null force is 9.6 micronewtons due to 5.6A DC current in power cable (routes power from liquid metal contacts to RF amplifier; interacts with magnetic damper system)>>

and see attached picture Fig. 13 RF Resistive Load mounted on torsion pendulum
Title: Re: EM Drive Developments
Post by: MikeMcCulloch on 10/06/2014 05:27 pm
Thank you for the warm welcome! Please note that I am at an early stage looking into the EmDrive. With some playful mathematics I found that MiHsC agrees with some EmDrive results, but the physics still needs more work, as I discuss here:
http://www.physicsfromtheedge.blogspot.co.uk/2014/10/mihsc-vs-emdrive-data-1.html (http://www.physicsfromtheedge.blogspot.co.uk/2014/10/mihsc-vs-emdrive-data-1.html)
In the meantime I'd like to collect more data, so if anyone knows of any result not in the table on my blog please do let me know & I can collate it for all to see (I'll need the geometry of the cavity, power, Q, frequency and dielectic properties, all of which seem to be important, and of course the thrust observed).
Title: Re: EM Drive Developments
Post by: aero on 10/06/2014 05:28 pm
I was looking for any evidence that dark matter interacts with RF waves. This leads to considering the red shift as perhaps due to dark matter interaction.

I found one guy who claims that dark matter does not exist, the missing mass is diatomic hydrogen. That was interesting so here is the link.

http://www.newtonphysics.on.ca/hydrogen/ (http://www.newtonphysics.on.ca/hydrogen/)

I found another guy who claims that light interaction with dark matter does cause the red shift. That was more interesting because he gave some math. Under the constraints of his model, which seem valid for light in interstellar space, he gives the equation:

dp/dt = -H p as the change in momentum, p, of a photon, where H is the Hubble constant equals about 2.2 x 10^-18 per second.
Note that the value of H has been changing and being refined rapidly over the last few years. This value is from about 2013.

The reason this is interesting is because this change in momentum attributed to dark matter implies an equal and opposite change in momentum in the dark matter.

At this point I'm not going to derive the effect that this proposed coupling of RF wave photons and dark matter may have on the thruster cavity. It seems small though.

Here is the link:

http://arxiv.org/ftp/arxiv/papers/0704/0704.1044.pdf (http://arxiv.org/ftp/arxiv/papers/0704/0704.1044.pdf)

Oh, this is a very popular thread, two posts during the time it took me to type mine. Gotta work on my typing speed.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 05:31 pm
Yes, but to a much lesser degree, and as I said, it is easy to isolate with a dummy load.  Woodward's thrusters form a perfect dummy load when the phase angle between the 1w and 2w portions of the signal are moved.  At 90* phase thrust is in one direction, and at 270* the other.  At 0* and 180* there is no thrust expected, so the thruster itself makes a perfect dummy load.

Woodward didn't have any coupling with the magnetic dampener.

Indeed on pages 10, 11, and 14. Dummy loads are mentioned. 10, 11 for Cannae. 14 for Emdrive. I gather that they used pretty darn good controls as experimentalist and this wasn't their first rodeo. They had lessons learned from previous campaigns. I do have issues with the seemingly small number of test campaigns, but I concede that it takes time to setup and run carefully. I have to bring up the fact that dummy loads by their very essence, convert rf to heat. How was the waste heat isolated? If, for instance, the waste heat of the dummy load were contributing to impulse EXACTLY the same as the test article, because the dominant effect was heat radiation, the dummy load null test would be invalid. So where was the dummy load? I can tell you from my own experience that dummy loads get very very hot.

Also, yes you are right, if the rf mode is setup where the standing wave is at minimum E, but max I at the boundary, it would be a dummy load and dump the rf as heat.
As way of background to @Mulletron's question, this is the excerpt from the report (p.14):

<<The net force is calculated by accounting for the null force present in the system. Null testing is performed by attaching the RF drive system to a 50 ohm load and running the system at full power. The null force testing indicated that there was an average null force of 9.6 micronewtons present in the as tested configuration. The presence of this null force was a result of the DC power current of 5.6 amps running in the power cable to the RF amplifier from the liquid metal contacts. This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system.>>

and Fig. 20 caption:

<<Figure 20. Null Test on Torsion Pendulum – average null force is 9.6 micronewtons due to 5.6A DC current in power cable (routes power from liquid metal contacts to RF amplifier; interacts with magnetic damper system)>>

and see attached picture Fig. 13 RF Resistive Load mounted on torsion pendulum

The dummy load was inside! Processing.......

Okay It wasn't elucidated that I can see, but in order to derive the  9.6 micronewton null force, you would have to take into account the thrust from the test article first, subtract the thrust (if any from the dummy load, which takes into account a lot of variables, including non linearaties of the heat produced by the dummy load itself coupled with the geometry of the test chamber. AND this is assuming the dummy load impulse effects were less than the test article, otherwise the dummy load's heat offload would dominate the impulse measured and it would appear thrust is happening, but they got the sign wrong...........(amiright?).You know what? This all sounds like BS because 1, we don't have enough info and 2 the effects are way small. I'm about to abandon this level of critical analysis of the paper because there are way too many assumptions based on too little info. The emdrive's supposed thrust is so close to the noise floor, that this way of analyzing it is not effective. We're gonna have to wait and see what other people do.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 06:06 pm
...

The dummy load was inside! Processing.......

Okay It wasn't elucidated that I can see, but in order to derive the  9.6 micronewton null force, you would have to take into account the thrust from the test article first, subtract the thrust (if any from the dummy load, which takes into account a lot of variables, including non linearaties of the heat produced by the dummy load itself coupled with the geometry of the test chamber. AND this is assuming the dummy load impulse effects were less than the test article, otherwise the dummy load's heat offload would dominate the impulse measured and it would appear thrust is happening, but they got the sign wrong...........(amiright?).You know what? This all sounds like BS because 1, we don't have enough info and 2 the effects are way small. I'm about to abandon this level of critical analysis of the paper because there are way too many assumptions based on too little info. The emdrive's supposed thrust is so close to the noise floor, that this way of analyzing it is not effective. We're gonna have to wait and see what other people do.
Well, these are some of the reasons why I have been bringing this up.  But there are more,  there are also magneto-thermo mechanical and dynamic aspects to this coupling as well.  That is why the classical set-up of Cavendish has been used to measure gravitational inverse-square law and the Casimir force in classical experiments and that's why Brito et al used a Cavendish type of setup with oil damping that falsified their inverted flexure beam experiments. 

I understand why Dr. White's team went this way: they wanted to have the setup to be small enough to fit inside their vacuum chamber.  This is the inverted pendulum they had. They did not have access to one as for example designed by Prof. Martinez-Sanchez at MIT to eliminate mode coupling between swinging and torsional modes.

Fine, we have to live with this: these are the experimental results we have and we need to take these issues into account in order to assess their validity.  So, we continue as we have been doing, we have made a lot of progress in analyzing this, and we should continue.

So, Ron's comments and answers concerning Mulletron's and my questions would still be appreciated, because the better we understand this coupling the better we can assess the significance of the results.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/06/2014 06:18 pm
...

The dummy load was inside! Processing.......

Okay It wasn't elucidated that I can see, but in order to derive the  9.6 micronewton null force, you would have to take into account the thrust from the test article first, subtract the thrust (if any from the dummy load, which takes into account a lot of variables, including non linearaties of the heat produced by the dummy load itself coupled with the geometry of the test chamber. AND this is assuming the dummy load impulse effects were less than the test article, otherwise the dummy load's heat offload would dominate the impulse measured and it would appear thrust is happening, but they got the sign wrong...........(amiright?).You know what? This all sounds like BS because 1, we don't have enough info and 2 the effects are way small. I'm about to abandon this level of critical analysis of the paper because there are way too many assumptions based on too little info. The emdrive's supposed thrust is so close to the noise floor, that this way of analyzing it is not effective. We're gonna have to wait and see what other people do.
Well, these are some of the reasons why I have been bringing this up.  But there are more,  there are also magneto-thermo mechanical and dynamic aspects to this coupling as well.  That is why the classical set-up of Cavendish has been used to measure gravitational inverse-square law and the Casimir force in classical experiments and that's why Brito et al used a Cavendish type of setup with oil damping that falsified their inverted flexure beam experiments. 

I understand why Dr. White's team went this way: they wanted to have the setup to be small enough to fit inside their vacuum chamber.  This is the inverted pendulum they had. They did not have access to one as for example designed by Prof. Martinez-Sanchez at MIT to eliminate mode coupling between swinging and torsional modes.

Fine, we have to live with this: these are the experimental results we have and we need to take these issues into account in order to assess their validity.  So, we continue as we have been doing, we have made a lot of progress in analyzing this, and we should continue.

So, Ron's comments and answers concerning Mulletron's and my questions would still be appreciated, because the better we understand this coupling the better we can assess the significance of the results.

I need to walk away from this for a while. I need to revisit the actual paper which I marked up with notes very early on, because it isn't fresh in my mind anymore and I have new insights to apply. I need to digest and reflect and give time for others to do the same.....
Title: Re: EM Drive Developments
Post by: aero on 10/06/2014 06:30 pm
Guys, you are analyzing EagleWorks' set-up to death. I can understand why we need clean data to see how the force actually behaves with power, frequency, Q, dielectric, ... but don't overlook the fact that Shayer and Ling also claim results. I don't know their test set-ups but I doubt that the error modes were common to the EagleWorks set-up.

In other words, "Don't lose sight of the forest for the trees!" :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 07:21 pm
Guys, you are analyzing EagleWorks' set-up to death. I can understand why we need clean data to see how the force actually behaves with power, frequency, Q, dielectric, ... but don't overlook the fact that Shayer and Ling also claim results. I don't know their test set-ups but I doubt that the error modes were common to the EagleWorks set-up.

In other words, "Don't lose sight of the forest for the trees!" :)

<<Shayer and Ling also claim results. I don't know their test set-ups >>

Hi @aero.  This, in my opinion, is, among Shawyer's papers, the one with the most complete explanation of his experimental setup and results:  http://www.emdrive.com/IAC-08-C4-4-7.pdf
Title: Re: EM Drive Developments
Post by: raketa on 10/06/2014 07:26 pm
I finish book James Woodward: Making Starship and Stargate and it is fascinating book.
1/He is very clearly explaining understanding of our universe base on evolution from Galileo, through Newton and Einstein and recent physicist Feyman, Hawkings. He explains that we are still not able to include influence of gravitation to model of universe.
2/He is revisiting thinking about these troubles and suggests that reason is not understanding of inertia. He is suggesting that inertia is gravitational influence of whole universe on any mass in it. He is also suggesting that electron rest mass could be negative. These 2 ideas first explain, for example how electron could exist at all. The other consequences, that we could temporarily manipulate inertia and get as reaction push from universe gravitation.
3/His theory is very deeply base on the mathematics, I am not able to judge, but it looks like he spend years and years to solve equations used Einstein and others physicist, to include gravity to these description.
4/Base on theoretical finding he was recognizing fact that is probably possible to manipulate inertia and it will be possible even with low budget  to build experiment to confirm his theory.
5/After they build first version they got big feedback, bigger then theory suggest, they spend years and years eliminate outside effect influences.  I think to find flow in their experiment will be silly, from afar without knowing detail and participating.
6/James abandon his persuade for 15 years to continue in practical experiments, because he was not able theoretically solve some issue of his theory.
7/Situation change when he find out that equation points to negative rest mass of electron. It was helping explain model of electron and help him to continue on building device to confirm his theory.
Conclusion:
I/His experiment is based on decades theoretical thinking and solving issue of gravity and inertia
II/They diligently work for years try to eliminate all outside influences to their measured thrust
III/His theory will be possible to confirm by experiment compare for example to string theory, that so much people believe, but not possible ever to confirm it by experiment
IV/His approach has strange consequences to time and reality, but in their theoretical approach it is step back to time we believe we are able to theorize and than confirm our theory by experiment, instead of just believing, like for example string theory
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 07:33 pm
Yes, but to a much lesser degree, and as I said, it is easy to isolate with a dummy load.  Woodward's thrusters form a perfect dummy load when the phase angle between the 1w and 2w portions of the signal are moved.  At 90* phase thrust is in one direction, and at 270* the other.  At 0* and 180* there is no thrust expected, so the thruster itself makes a perfect dummy load.

Woodward didn't have any coupling with the magnetic dampener.
thanks.

And what specific kind of "Woodward's thruster" was tested by Woodward et.al. with that setup, the MLT or MET type of thruster?
Both.  The MLT's only generate thrusts in the uN's.  The MET's in the mN.  I'd expect the next gen using PMN should produce far more thrust, but unless he's added some thermal stability, it will just be impulses as he sweeps through the resonant frequency, so far less impressive than one would like.  PMN only has its Colossal Dielectric Constant (CDC) of about 20,000 within a 2*k bandwidth, and only that high when it is sintered in a lead oxide atmosphere to avoid the pyrochlore phase of the compound, and I don't think that's how Woodward's stuff was sintered.  So it will be disappointing, but still when within it's thermal bandwidth, far better than the PZT he was using.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/06/2014 07:41 pm
Okay I made a cad error...

Apology accepted. (http://www.youtube.com/watch?v=Iwio208q3jY)
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 07:59 pm
. . .otherwise the dummy load's heat offload would dominate the impulse measured and it would appear thrust is happening, but they got the sign wrong...........(amiright?)

Sonny does know better than to trust tests sans vacuum.  And really you can't say too much about tests done without except note that thermal contributions are not prompt, and have a slow decay as well.  Still you want to eliminate them, and ion wind and you can't do that without vacuum.

So yeah, I am agreeing with the general sentiment that we can't do too much analysis of a conference paper, when the authors admit they're still in preliminary testing and haven't worked out their protocols yet.  They absolutely have to get the stuff in vacuum.  Once you have thrust in vacuum, then you can start to look more closely.

Too I would note that the noise floor is not that much an issue.  We retrieve signals out of the noise floor all the time.  Ideally yes, you want a signal way above, but there are authentic ways to tease the signal out, given sufficient controls.  And again for this level of mastery you generally want to run continuous, not sweep through a "sweet spot", be it resonance, or thermal or a combination.

With Eagle's funding, they ought to be able to provide all the necessary controls to get conclusive figures.  They are just not there yet, and hence reason to note the differences between conference papers and peer review.  And if NASA is going to go for multiple labs on these issues, seems there are many millions of dollars going into this now.  DARPA first at Eagle but if NASA mobilizes JPL, Stennis and maybe Marshall, we should get some answers.  IMHO, every one of the centers ought to have a lab able to do this sort of work.

After all, is there something MORE important to NASA than developing a Spacedrive?
Title: Re: EM Drive Developments
Post by: zen-in on 10/06/2014 08:02 pm
A previous lurker and a newly minted member here.   I have been following this topic for some time and just want to throw in a few thoughts I have had, for what they are worth.
 1) The MCL amplifier used is a Class AB amp.   The output, unless it has a DC blocking cap inside the amp, will have a DC offset = Vdd/2.   My guess is the amp does not have a DC blocking cap because that would affect the bandwidth and MCL likes to advertise their amplifiers as being broadband.   It is also possible that different load configurations (reflected power) will change the offset.   When a dummy load is used the RF feedline is totally coaxial so no external magnetic effects would be present.   However when the cavity is loaded the internal loop, if there is a DC offset, would act like an electromagnet.   Any DC magnetic field generated in the loop would not be shielded by the metal.   There is no mention of any testing or mitigation of a DC offset from the Class AB amplifier in the paper.   I would not expect the dual directional couplers used between the amplifier and the cavity to have DC blocking caps.
 2)  I also question the RF theory of this device.   It is an untuned cavity with a very high Q ceramic resonator inside.   Almost all the RF power will be in the ceramic, and very little power will be bouncing off the inside Cu walls of the cavity.   The cavity is just a Faraday cage.   Its end caps are single-sided FR4 (fiberglass PCB material).  The S11 plot (voltage reflection coefficient at the input) shows this very well.   Very, very little RF power is reflected back to the input at 1932.6 MHz.   That is to be expected.  Any RF-tight enclosure with the same ceramic resonator inside would produce a similar S11 plot.   There is no mystery about it.   Well, except where does the anomalous force come from?
 
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 08:06 pm
2/He is revisiting thinking about these troubles and suggests that reason is not understanding of inertia. He is suggesting that inertia is gravitational influence of whole universe on any mass in it. He is also suggesting that electron rest mass could be negative. These 2 ideas first explain, for example how electron could exist at all. The other consequences, that we could temporarily manipulate inertia and get as reaction push from universe gravitation.
It's okay to say this but I just want to point out that what Woodward is saying is that electrons have an undressed negative mass.  This distinction between dressed and undressed is not like between rest and other states of an electron.  He gives the history behind the notion of "dressing" electrons and those chapters (6 & 7?) in the book are amongst the best.  I am extremely impressed with the complexity of the issue and Woodward's ability as per usual to make it crystal clear.  40 years teaching GR will do that for you.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 08:11 pm
I am a little lost because I don't have the paper, but just to clarify: we're here talking about 2 different geometries at once?  The truncated cone/Shawyer resonator is powered AC, but the power supply for the resonator is on the balance arm and it is powered by DC?  And the other device, similarly?  Both have the power supply on the balance arm powered DC and that DC is coupling with the magnetic damping?
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 08:15 pm
.... for this level of mastery you generally want to run continuous, not sweep through a "sweet spot", be it resonance,...

While I understand that you are here making a general point, I need to clarify that my understanding of the NASA Eagleworks test results is that they were run at fixed constant frequencies during the duration (ranging from 30 seconds to 45 seconds) of the thrust experiments.  They were not frequency sweeps.

Concerning resonance their tests at 1933 MHz and 1937 MHz are very perplexing (see first two rows of table attached below) because the test with a Q factor 2.5 times higher resulted in a thrust force 1/2 as large with practically the same power input and practically the same frequency (0.3% difference).  Such a result flies on the face of a number of theories (including Dr. White's) that predict a higher thrust force proportional to the Q factor (everything else being the same).

Moreover, since these frequencies are only 0.3 % apart this result is very perplexing (and adds to the issues previously discussed regarding  coupling effects).   A 1933 MHz peak does not appear in their S21 plot attached below.  It only shows a 1936 MHz peak. Of course their plot does not have a frequency range detail that would readily show this 0.3% difference but they did not offer any zooming details.  Their S21 plot does not show such a high resonance peak in that region compared with other peak frequencies, either.  Another interesting thing is that their COMSOL prediction is off the most (compared to the actual amplitudes) in this region.  The COMSOL finite element results [shown in the upper part of the picture, with a white background] predicts a much higher resonance in this region that what the S21 [shown with a black background] results show. (The COMSOL finite element results are also off regarding the frequency at which the peak appears, showing the peak occurring at ~1950 MHz)
Title: Re: EM Drive Developments
Post by: RonM on 10/06/2014 08:17 pm
His approach has strange consequences to time and reality, but in their theoretical approach it is step back to time we believe we are able to theorize and than confirm our theory by experiment, instead of just believing, like for example string theory

I'm glad you brought that up. I'm very skeptical about this whole thing, but at least it can be tested. That's a big plus in my book.

Since string theory can't be tested, it is more philosophy than science. Sure it is a logical progression of science and the math is 'beautiful' as mathematicians like to say, but that doesn't mean it is how reality works.
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 09:28 pm
A previous lurker and a newly minted member here.   I have been following this topic for some time and just want to throw in a few thoughts I have had, for what they are worth.
 1) The MCL amplifier used is a Class AB amp.   The output, unless it has a DC blocking cap inside the amp, will have a DC offset = Vdd/2.   My guess is the amp does not have a DC blocking cap because that would affect the bandwidth and MCL likes to advertise their amplifiers as being broadband.   It is also possible that different load configurations (reflected power) will change the offset.   When a dummy load is used the RF feedline is totally coaxial so no external magnetic effects would be present.   However when the cavity is loaded the internal loop, if there is a DC offset, would act like an electromagnet.   Any DC magnetic field generated in the loop would not be shielded by the metal.   There is no mention of any testing or mitigation of a DC offset from the Class AB amplifier in the paper.   I would not expect the dual directional couplers used between the amplifier and the cavity to have DC blocking caps.
 2)  I also question the RF theory of this device.   It is an untuned cavity with a very high Q ceramic resonator inside.   Almost all the RF power will be in the ceramic, and very little power will be bouncing off the inside Cu walls of the cavity.  The cavity is just a Faraday cage.   Its end caps are single-sided FR4 (fiberglass PCB material).  The S11 plot (voltage reflection coefficient at the input) shows this very well.   Very, very little RF power is reflected back to the input at 1932.6 MHz.   That is to be expected.  Any RF-tight enclosure with the same ceramic resonator inside would produce a similar S11 plot.   There is no mystery about it.   Well, except where does the anomalous force come from?
 

WELCOME to the forum.  Great post.

The S11 plot you are referring to is this one I attach below, is that right? (I want people without immediate access to the report to see it here).  In my report the resolution for this plot is very low, so even if I magnify it, it is very difficult to ascertain the frequency.  (The S21 plot, by comparison is much larger and easier to read).  We can tell the Q=7320, and therefore from the text, ascertain the frequency (1932.6 MHz).
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 09:43 pm

 1) The MCL amplifier used is a Class AB amp.   The output, unless it has a DC blocking cap inside the amp, will have a DC offset = Vdd/2.   My guess is the amp does not have a DC blocking cap because that would affect the bandwidth and MCL likes to advertise their amplifiers as being broadband.   It is also possible that different load configurations (reflected power) will change the offset.  When a dummy load is used the RF feedline is totally coaxial so no external magnetic effects would be present.   However when the cavity is loaded the internal loop, if there is a DC offset, would act like an electromagnet.   Any DC magnetic field generated in the loop would not be shielded by the metal.   There is no mention of any testing or mitigation of a DC offset from the Class AB amplifier in the paper.  I would not expect the dual directional couplers used between the amplifier and the cavity to have DC blocking caps...
So, if I understand you correctly you agree that the internal loop will act as an electromagnet, and the DC magnetic field will NOT be shielded by the metal. [I would add that any slowly-varying components of the magnetic field will not be shielded either]

We also know that they are using three Neodymium (NdFeB Grade N42) block magnets and they know they have an interaction from the magnetic damper responsible for an acknowledged ~10 microNewton measured artifact and a changing baseline. 

(They blame this as resulting from coupling between the magnetic damper and the power cable, though:

<<This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system.>> p.14

)

Therefore, there could be an interaction between the DC magnetic field escaping the device, interacting with the magnetic damping field and producing a spurious thrust force that maybe an artifact rather than real thrust ?

In other words, if it is a magnetic artifact, this thing would not propel itself in outer space?
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 09:50 pm
... I also question the RF theory of this device.   It is an untuned cavity with a very high Q ceramic resonator inside.   Almost all the RF power will be in the ceramic, and very little power will be bouncing off the inside Cu walls of the cavity.   The cavity is just a Faraday cage.  ...
 
Although several of us have come to a similar conclusion, I would like to explore your reasoning a little further.

How do you know that it has a very high Q resonator inside?  (Is it because when they remove it they measure no thrust force?)

How do you know that the resonator is a ceramic?  The report mentions a PTFE ("Teflon") dielectric resonator (albeit for the Cannae device if my memory serves me correctly).  Did I miss the "ceramic" information in the report somewhere. Is this information from another report?

Thank you again for your great post  :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 09:53 pm
...   Its end caps are single-sided FR4 (fiberglass PCB material). ...

OK, this is great information, but I must ask, how do you know that it is single-sided PCB material? Is that in the report?  Is it from your experience? Is it from another report?

How do we know that there is no copper plate behind the PCB material?

Thanks again  :) great to have you here
Title: Re: EM Drive Developments
Post by: frobnicat on 10/06/2014 09:55 pm
I am a little lost because I don't have the paper, but just to clarify: we're here talking about 2 different geometries at once?  The truncated cone/Shawyer resonator is powered AC, but the power supply for the resonator is on the balance arm and it is powered by DC?  And the other device, similarly?  Both have the power supply on the balance arm powered DC and that DC is coupling with the magnetic damping?

I guess it is about zen-in (Welcome) post (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1267140#msg1267140) ?
If I understood anything at all, I would say yes. The coupling of the DC from lab to "onboard" RF generator is explicitly taken into account by being evaluated with dummy load, then subtracted (albeit "linearly" at the great despair of dr Rodal...)

By AC you mean RF (GHz) don't you ? It wasn't clear in one of your previous post, AC vs DC, Woodward's  devices don't use a modulation of the RF signal, do they ?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/06/2014 10:03 pm
...regardless of the dielectric's acoustic geometry, M-E physics cannot explain thrust from a DC signal.  It can explain thrust impulses from switching transients, and AC signals, but not DC.  You've been reading the paper recently so you should be able to tell more easily than I whether the setup meets the criteria to be acting as a MET....

This is very useful information, thank you.  Could you be so kind as to review the following excerpt from the NASA Eagleworks report and let us know your opinion of whether "M-E physics" can explain thrust from the following signal:

p.8 <<During testing, the Test Engineer controls the RF frequency generation via a 0-to-28 volts dc power input to a voltage-controlled oscillator (VCO). The VCO RF signal output is passed to a variable voltage attenuator (VVA), the output of which is controlled by the Test Engineer via a 0-to-17 volts dc power input. Based upon the VVA output, the amplifier will output up to approximately 28 watts. Amplifier output passes to a dual-directional coupler (DDC), which allows forward and reflected power measurements to be obtained as the power is simultaneously passed to the test article input port. The Test Engineer monitors forward and reflected power and adjusts the input frequency to obtain the desired combination of cavity frequency and power delivery to the cavity.>>
It's DC, so M-E theory cannot explain constant thrust from such a setup unless there is significant ripple in the signal.  There's no data about ripple here.  M-E theory could explain thrust form switching transients here.  Did this experiment generate constant thrust or thrust impulses during switching?

There, what DC are you talking about ? You mean DC like in a 9V battery, or RF power at 1GHz but constant (unmodulated) ? And if modulated, how should it be modulated, in amplitude, at what freq, what shape ?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/06/2014 10:34 pm
It wasn't clear in one of your previous post, AC vs DC, Woodward's  devices don't use a modulation of the RF signal, do they
They haven't in the past though they may in the future.  There is reason to suppose interrupting the AC into a pulsed AC signal could significantly enhance the thrust, and this is the subject of Jim's latest patent app.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/06/2014 10:35 pm
I would say, assuming it's possible at all to "burn" DM mass into energy, a few % of c, but with unlimited delta V (since feeding on the way)

At least I get the Bussard ramjet idea.  More or less, you don't have to carry your "oxidiser", but you do have to carry your "fuel".  I think.

Not for a Bussard ramjet : incoming mass is the energy, because you fly in a (diluted) gas of light nuclei that has still punch in it to be released when fused. You could do it also in a diluted gas of heavy nuclei (mmm, diluted gas of thorium). But not in a diluted gaz of iron 56. It's like flying in a fuel/oxidiser mixture, only a fuel oxidiser mix is unstable long term, while light nuclei needs special conditions to release their potential (energy) and are otherwise quite stable. But I'm sure you knew that ?

Quote
Quote from: Frobnicat & Mulletron
To be clear : this rectifier effect hypothesis had nothing to do with DM...

No, I got that.  I'm just designing that spacecraft which uses the "rectifier effect hypothesis".  While you don't need an evacuated glass container for the "tube", there would be a lot of mass, and a large size associated with the spacecraft.

Riffing off of caffeine at the moment, I'd guess that you'd need several families of VonNeuman devices, spread out over a large area, fed material some how, and powered, somehow, in order to build the spacecraft.

Which, to my mind, gets back to wondering briefly, on the BOE, how big would that spacecraft have to be?  Both the DM ramjet and the rectifier effect ones.

Well, frankly, for the "rectifier effect" spacecraft, it was a polite way to say the "anomalous thrusts" are spurious measures related to experimental apparatus having a big permanent magnet nearby interfering with some unwanted (and unaccounted for) DC component somewhere. Then you can build as big or small a "rectifier" spaceship you want, as long as another properly driven spaceship is carrying a comparatively big permanent magnet in the vicinity. This would just be a less than efficient tractor beam from tugboat to a free floating hull (a rope being more efficient).

Now if I saw a humongous "rectifier star cruiser" full of guns exiting a wormhole in front of my space limo, I could revise my opinion.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/06/2014 11:10 pm
.../...
Any DC magnetic field generated in the loop would not be shielded by the metal.   There is no mention of any testing or mitigation of a DC offset from the Class AB amplifier in the paper.   I would not expect the dual directional couplers used between the amplifier and the cavity to have DC blocking caps.
.../...

Quote from: wikipedia microwave cavity
The electromagnetic fields in the cavity are excited via external coupling. An external power source is usually coupled to the cavity by a small aperture, a small wire probe or a loop.[2] External coupling structure has an effect on cavity performance and needs to be considered in the overall analysis.

from there : (http://www.allaboutcircuits.com/vol_2/chpt_14/8.html)
(http://sub.allaboutcircuits.com/images/02409.png)

You mean that kind of loop, or just the loop of the RF circuit ? Unless there is a conducting loop, isn't the circuit supposed to be open in DC, that is, the dielectric cavity is the DC isolating cap in the circuit between the coupling stub and the walls ? Wouldn't a loop closed to DC short circuit the polarisation of the output stage of the amplifier if it had no AC coupling (DC blocking) caps ? Could that go unnoticed ?
Otherwise, is there any indication of a conducting loop as the coupling used by "anomalous thrust...", judge Rodal maybe you can state about that ?

Edit : what would be the effect of no loop, stub_in/wall_out DC blocking cap configuration, running at high (near breaking) RF E fields and a DC bias in potential ? Then the dielectric could no longer easily be considered perfect isolator, and this bias in potential would change a lot of things, no more "rectifier effect" (sorry John) to explain a direct current component...
Title: Re: EM Drive Developments
Post by: Rodal on 10/06/2014 11:30 pm
... The cavity is just a Faraday cage.   . ...
In other words, the only purpose served by the truncated cone shape of the device is to contain the microwave energy within the cavity, is that right?
Title: Re: EM Drive Developments
Post by: raketa on 10/06/2014 11:37 pm
2/He is revisiting thinking about these troubles and suggests that reason is not understanding of inertia. He is suggesting that inertia is gravitational influence of whole universe on any mass in it. He is also suggesting that electron rest mass could be negative. These 2 ideas first explain, for example how electron could exist at all. The other consequences, that we could temporarily manipulate inertia and get as reaction push from universe gravitation.
It's okay to say this but I just want to point out that what Woodward is saying is that electrons have an undressed negative mass.  This distinction between dressed and undressed is not like between rest and other states of an electron.  He gives the history behind the notion of "dressing" electrons and those chapters (6 & 7?) in the book are amongst the best.  I am extremely impressed with the complexity of the issue and Woodward's ability as per usual to make it crystal clear.  40 years teaching GR will do that for you.
Hi Ron,
 thank you very much I planed it to read again any way. I will focus on these chapter. I make mistake to buy kindle version, I know it will bite me. For these type books is beter to have paper version. But I was interested to read right then anyway. I have to agree that he explain GR better than any other author I have chance to read it. It was so fascinating that I couldn't stop listening book, walking with my 2 years son and dreaming that maybe there is small chance he will able to reach stars.
Title: Re: EM Drive Developments
Post by: 93143 on 10/06/2014 11:47 pm
...regardless of the dielectric's acoustic geometry, M-E physics cannot explain thrust from a DC signal.  It can explain thrust impulses from switching transients, and AC signals, but not DC.  You've been reading the paper recently so you should be able to tell more easily than I whether the setup meets the criteria to be acting as a MET....

This is very useful information, thank you.  Could you be so kind as to review the following excerpt from the NASA Eagleworks report and let us know your opinion of whether "M-E physics" can explain thrust from the following signal:

p.8 <<During testing, the Test Engineer controls the RF frequency generation via a 0-to-28 volts dc power input to a voltage-controlled oscillator (VCO). The VCO RF signal output is passed to a variable voltage attenuator (VVA), the output of which is controlled by the Test Engineer via a 0-to-17 volts dc power input. Based upon the VVA output, the amplifier will output up to approximately 28 watts. Amplifier output passes to a dual-directional coupler (DDC), which allows forward and reflected power measurements to be obtained as the power is simultaneously passed to the test article input port. The Test Engineer monitors forward and reflected power and adjusts the input frequency to obtain the desired combination of cavity frequency and power delivery to the cavity.>>
It's DC, so M-E theory cannot explain constant thrust from such a setup unless there is significant ripple in the signal.  There's no data about ripple here.  M-E theory could explain thrust form switching transients here.  Did this experiment generate constant thrust or thrust impulses during switching?

There, what DC are you talking about ? You mean DC like in a 9V battery, or RF power at 1GHz but constant (unmodulated) ? And if modulated, how should it be modulated, in amplitude, at what freq, what shape ?


This should probably get another look.

Ron, you said DC couldn't explain the thrust (and Rodal said that was very helpful information).  But the DC in this case is being fed into an RF oscillator, which would seem to change the picture a bit, no?
Title: Re: EM Drive Developments
Post by: 93143 on 10/06/2014 11:51 pm
Given Woodward's assertions about exciting an oscillation in a dielectric and then pushing on it at an opportune time to move forward clearly does violate conservation of momentum.

If I'm not gravely mistaken, Woodward's theory is supposed to involve excitation of mass fluctuations much larger than the E/c² you'd calculate from the local electromagnetics, via gravitational interaction with distant matter.  It's supposed to conserve momentum via that same interaction.

(Usual caveat: I haven't yet satisfied myself that Woodward's derivation is valid and correctly interpreted.  I'm working on it.)

They're the same thing.  They both gravitate and have inertia.  The scale is wildly different, but that's immaterial.
http://en.wikipedia.org/wiki/Nordtvedt_effect

http://en.wikipedia.org/wiki/Equivalence_principle

Also note that the Nordtvedt effect has not been observed, despite multiple attempts.

Quote
They are not the same thing in our universe.

http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

Quote
Remember that mass is constrained over space and energy is constrained over time!

Perhaps you should rephrase this, because right now it makes no sense.

Quote
Also remember that a polarized cap and a unpolarized cap DO FALL at exactly the same rate.

That's because this:
Quote
Rest Mass and Inertial Mass being different

is forbidden by the Einstein Equivalence Principle.  A charged capacitor weighs more, but that gives it more inertia, so the increased force of gravity doesn't result in any extra acceleration.

Quote
I bet if Woodward put his "symmetrically shaped in the direction of desired thrust" devices in a conical faraday cage, it probably would work.

Woodward's devices already work.  Repeatably, well above the noise floor, in vacuum, with what appear to be rigorous experimental controls, and to within an order of magnitude of a priori thrust predictions.

I know Ron said thrust predictions are not made.  He was wrong.  There's a fairly recent derivation that includes the bulk acceleration requirement explicitly and contains an assumption or two regarding the properties of the material, and it shows surprisingly good quantitative agreement with experiment.

Though I have the impression that Woodward's group treats this thrust equation more as a curiosity than a falsifiable prediction, because there are still too many loose variables...

I'm also assuming it is safe to say that Gravitational Mass can never be separated from Rest Mass, that they are invariant. I think it is safe to say that indeed gravitational self energy does indeed contribute to inertial mass, and that may not be the only thing or the only way which in which mechanisms contributes to inertial mass, in our universe, either way gravitational self energy DOES. Verified by experiment.

What exactly do you mean by "verified by experiment"?

And what do you mean by "safe"?  You're essentially postulating the opposite of the Nordtvedt effect, and of course a blatant violation of the strong equivalence principle (which BTW Woodward's theory supposedly respects, being based on GR; I haven't yet got my head around how exactly it manages this).
Title: Re: EM Drive Developments
Post by: zen-in on 10/07/2014 12:29 am

 1) The MCL amplifier used is a Class AB amp.   The output, unless it has a DC blocking cap inside the amp, will have a DC offset = Vdd/2.   My guess is the amp does not have a DC blocking cap because that would affect the bandwidth and MCL likes to advertise their amplifiers as being broadband.   It is also possible that different load configurations (reflected power) will change the offset.  When a dummy load is used the RF feedline is totally coaxial so no external magnetic effects would be present.   However when the cavity is loaded the internal loop, if there is a DC offset, would act like an electromagnet.   Any DC magnetic field generated in the loop would not be shielded by the metal.   There is no mention of any testing or mitigation of a DC offset from the Class AB amplifier in the paper.  I would not expect the dual directional couplers used between the amplifier and the cavity to have DC blocking caps...
So, if I understand you correctly you agree that the internal loop will act as an electromagnet, and the DC magnetic field will NOT be shielded by the metal. [I would add that any slowly-varying components of the magnetic field will not be shielded either]

We also know that they are using three Neodymium (NdFeB Grade N42) block magnets and they know they have an interaction from the magnetic damper responsible for an acknowledged ~10 microNewton measured artifact and a changing baseline. 

(They blame this as resulting from coupling between the magnetic damper and the power cable, though:

<<This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system.>> p.14

)

Therefore, there could be an interaction between the DC magnetic field escaping the device, interacting with the magnetic damping field and producing a spurious thrust force that maybe an artifact rather than real thrust ?

In other words, if it is a magnetic artifact, this thing would not propel itself in outer space?

I'm just raising the question.  It is something that needs to be ruled out.   If the MCL amp does have a DC offset on its output that could be a reason for the anomalous force they have measured.  I doubt a short wire probe would work. because it would have to be 1/4 λ and would not fit in the cavity.
Title: Re: EM Drive Developments
Post by: zen-in on 10/07/2014 12:34 am
...   Its end caps are single-sided FR4 (fiberglass PCB material). ...

OK, this is great information, but I must ask, how do you know that it is single-sided PCB material? Is that in the report?  Is it from your experience? Is it from another report?

How do we know that there is no copper plate behind the PCB material?

Thanks again  :) great to have you here

I have used FR4 and recognize the red logos on the bare side.  Also the copper side can be seen extending out in one of the photos.   It looks like the cone section of the cavity is made from lighter weight FR4, using washer-shaped sections to hold it in shape and strengthen it.   Lead-Tin solder is used to solder it all together.  The solder line can be seen where the large end cap meets the cone.
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 12:40 am
...   Its end caps are single-sided FR4 (fiberglass PCB material). ...

OK, this is great information, but I must ask, how do you know that it is single-sided PCB material? Is that in the report?  Is it from your experience? Is it from another report?

How do we know that there is no copper plate behind the PCB material?

Thanks again  :) great to have you here

I have used FR4 and recognize the red logos on the bare side.  Also the copper side can be seen extending out in one of the photos.   It looks like the cone section of the cavity is made from lighter weight FR4, using washer-shaped sections to hold it in shape and strengthen it.   Lead-Tin solder is used to solder it all together.  The solder line can be seen where the large end cap meets the cone.

OK it is great to have you confirm this as @notsosureofit had also pointed out (early in the thread) that this was single sided PCB material he was familiar with.
Title: Re: EM Drive Developments
Post by: zen-in on 10/07/2014 12:57 am
... I also question the RF theory of this device.   It is an untuned cavity with a very high Q ceramic resonator inside.   Almost all the RF power will be in the ceramic, and very little power will be bouncing off the inside Cu walls of the cavity.   The cavity is just a Faraday cage.  ...
 
Although several of us have come to a similar conclusion, I would like to explore your reasoning a little further.

How do you know that it has a very high Q resonator inside?  (Is it because when they remove it they measure no thrust force?)

How do you know that the resonator is a ceramic?  The report mentions a PTFE ("Teflon") dielectric resonator (albeit for the Cannae device if my memory serves me correctly).  Did I miss the "ceramic" information in the report somewhere. Is this information from another report?

Thank you again for your great post  :)

Yes it looks like I'm wrong about that.  Only the Cannae device has a 1/4 λ antenna inside the long section, with a ptfe slug.   The return loss (S11) measurement shows the resonant frequency of the loop and cavity and that very little of the RF power that goes into the cavity gets reflected out.   
Title: Re: EM Drive Developments
Post by: zen-in on 10/07/2014 01:03 am
... The cavity is just a Faraday cage.   . ...
In other words, the only purpose served by the truncated cone shape of the device is to contain the microwave energy within the cavity, is that right?

I acknowledge the theory of this device has something to do with its cone shape.   But as an RF device it is a cavity filter.   It is also a Faraday cage because the inside is all Cu.  (my assumption based on the photos and the S11 plot).
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 01:07 am
... I also question the RF theory of this device.   It is an untuned cavity with a very high Q ceramic resonator inside.   Almost all the RF power will be in the ceramic, and very little power will be bouncing off the inside Cu walls of the cavity.   The cavity is just a Faraday cage.  ...
 
Although several of us have come to a similar conclusion, I would like to explore your reasoning a little further.

How do you know that it has a very high Q resonator inside?  (Is it because when they remove it they measure no thrust force?)

How do you know that the resonator is a ceramic?  The report mentions a PTFE ("Teflon") dielectric resonator (albeit for the Cannae device if my memory serves me correctly).  Did I miss the "ceramic" information in the report somewhere. Is this information from another report?

Thank you again for your great post  :)

Yes it looks like I'm wrong about that.  Only the Cannae device has a 1/4 λ antenna inside the long section, with a ptfe slug.   The return loss (S11) measurement shows the resonant frequency of the loop and cavity and that very little of the RF power that goes into the cavity gets reflected out.

So we know that in the NASA Eagleworks tests:

The Cannae device had a PTFE dielectric resonator

The truncated cone ("tapered cavity") also had a dielectric resonator (because they stated that when they took it out they measured no thrust), but we don't know exactly what kind of dielectric material
Title: Re: EM Drive Developments
Post by: zen-in on 10/07/2014 01:25 am
.../...
Any DC magnetic field generated in the loop would not be shielded by the metal.   There is no mention of any testing or mitigation of a DC offset from the Class AB amplifier in the paper.   I would not expect the dual directional couplers used between the amplifier and the cavity to have DC blocking caps.
.../...

Quote from: wikipedia microwave cavity
The electromagnetic fields in the cavity are excited via external coupling. An external power source is usually coupled to the cavity by a small aperture, a small wire probe or a loop.[2] External coupling structure has an effect on cavity performance and needs to be considered in the overall analysis.

from there : (http://www.allaboutcircuits.com/vol_2/chpt_14/8.html)
(http://sub.allaboutcircuits.com/images/02409.png)

You mean that kind of loop, or just the loop of the RF circuit ? Unless there is a conducting loop, isn't the circuit supposed to be open in DC, that is, the dielectric cavity is the DC isolating cap in the circuit between the coupling stub and the walls ? Wouldn't a loop closed to DC short circuit the polarisation of the output stage of the amplifier if it had no AC coupling (DC blocking) caps ? Could that go unnoticed ?
Otherwise, is there any indication of a conducting loop as the coupling used by "anomalous thrust...", judge Rodal maybe you can state about that ?

Edit : what would be the effect of no loop, stub_in/wall_out DC blocking cap configuration, running at high (near breaking) RF E fields and a DC bias in potential ? Then the dielectric could no longer easily be considered perfect isolator, and this bias in potential would change a lot of things, no more "rectifier effect" (sorry John) to explain a direct current component...

In pages 15, 16 of the paper the 16 mm and 12.5 mm loop antenna used to drive the cone-shaped cavity are mentioned.   The wireframe drawings of the cavity also show a loop attached to what looks like an RF connector on the outside of the cone.    The MCL ZHL-100 amplifier is rated at 100 W with a 28 V supply.  Since they are only running it at 17 or 2.6 Watts the DC supply would be much less than 28 V.   So if there was a DC offset coming from the class AB amp that was not blocked there would not be a significant overload of the power supply or amp.   This is just theoretical.   I don't know if the RF amps DC offset is blocked.   Nothing in the paper indicates that it is.   I don't know enough about the Cannae device to know if it uses a loop or a 1/4 λ probe, but all the RF cavity filters I have seen use loops.
Title: Re: EM Drive Developments
Post by: zen-in on 10/07/2014 01:43 am
... I also question the RF theory of this device.   It is an untuned cavity with a very high Q ceramic resonator inside.   Almost all the RF power will be in the ceramic, and very little power will be bouncing off the inside Cu walls of the cavity.   The cavity is just a Faraday cage.  ...
 
Although several of us have come to a similar conclusion, I would like to explore your reasoning a little further.

How do you know that it has a very high Q resonator inside?  (Is it because when they remove it they measure no thrust force?)

How do you know that the resonator is a ceramic?  The report mentions a PTFE ("Teflon") dielectric resonator (albeit for the Cannae device if my memory serves me correctly).  Did I miss the "ceramic" information in the report somewhere. Is this information from another report?

Thank you again for your great post  :)

Yes it looks like I'm wrong about that.  Only the Cannae device has a 1/4 λ antenna inside the long section, with a ptfe slug.   The return loss (S11) measurement shows the resonant frequency of the loop and cavity and that very little of the RF power that goes into the cavity gets reflected out.

So we know that in the NASA Eagleworks tests:

The Cannae device had a PTFE dielectric resonator

The truncated cone ("tapered cavity") also had a dielectric resonator (because they stated that when they took it out they measured no thrust), but we don't know exactly what kind of dielectric material

The dielectric resonators I have seen all used a hard ceramic.  PTFE is soft, expands with heat and humidity and so would not be useful as a resonator.   PTFE is used as a structural and support element in RF connectors, etc because it is low loss.   I suspect some type of ceramic resonator was used in the cone shaped device because the return loss is way down at -49 dB.  Cavity filters of similar size are used in radio communications systems to provide selectivity for a desired frequency.   The VNA swept waveform looks very similar.   However the cavity filters used in radio communications have a 1/4 λ stub inside that can be tuned by turning a screw.  This 1/4 λ stub is what makes the cavity so selective.   If the cone shaped device was just an empty cavity with a loop drive I don't see how it would be so selective (have a Q = 7300).   However returning to my earlier statement about the RF theory of this device:  It appears it MUST have some kind of high Q resonator inside.   If that is the case then almost all the RF power is concentrated in this resonator and is not bouncing off any of the walls.    The question is how is this resonator excited?  That information is missing from the paper.
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 12:52 pm


The dielectric resonators I have seen all used a hard ceramic.  PTFE is soft, expands with heat and humidity and so would not be useful as a resonator.   PTFE is used as a structural and support element in RF connectors, etc because it is low loss.   I suspect some type of ceramic resonator was used in the cone shaped device because the return loss is way down at -49 dB.  Cavity filters of similar size are used in radio communications systems to provide selectivity for a desired frequency.   The VNA swept waveform looks very similar.   However the cavity filters used in radio communications have a 1/4 λ stub inside that can be tuned by turning a screw.  This 1/4 λ stub is what makes the cavity so selective.   If the cone shaped device was just an empty cavity with a loop drive I don't see how it would be so selective (have a Q = 7300).   However returning to my earlier statement about the RF theory of this device:  It appears it MUST have some kind of high Q resonator inside.   If that is the case then almost all the RF power is concentrated in this resonator and is not bouncing off any of the walls.    The question is how is this resonator excited?  That information is missing from the paper.
@zen-in

What do you make of NASA's tests at 1933 MHz and 1937 MHz (see first two rows of table attached below): the test with a Q factor 2.5 times higher [Q=18100 instead of Q=7320] resulted in a thrust force 1/2 as large with practically the same power input and practically the same frequency (0.3% difference).  Such a result flies on the face of a number of theories (including Dr. White's, and Prof. McCulloch's) that predict a higher thrust force proportional to the Q factor (everything else being the same).

Also, as you said, the S11 plot [the very bottom attachment] shows that very little RF power is reflected back to the input at 1933 MHz.  The S11 plot has very little definition in my report, and even if I zoom it, it is impossible for me to read the numbers.  But from the shape of the S11 signal, I don't see from the S11 plot something to justify the completely different results at 1937 MHz (0.3 % difference in frequency).

A 1933 MHz peak does not appear in their S21 plot attached below.  It only shows a 1936 MHz peak. Of course their plot does not have a frequency range detail that would readily show this 0.3% difference but they did not offer any zooming details.  Their S21 plot does not show such a high resonance peak in that region compared with other peak frequencies, either.  Another interesting thing is that their COMSOL prediction is off the most (compared to the actual amplitudes) in this region.  The COMSOL finite element results [shown in the upper part of the picture, with a white background] predicts a much higher resonance in this region that what the S21 [shown with a black background] results show. (The COMSOL finite element results are also off regarding the frequency at which the peak appears, showing the peak occurring at ~1950 MHz)

Title: Re: EM Drive Developments
Post by: Mulletron on 10/07/2014 01:20 pm
Given Woodward's assertions about exciting an oscillation in a dielectric and then pushing on it at an opportune time to move forward clearly does violate conservation of momentum.

If I'm not gravely mistaken, Woodward's theory is supposed to involve excitation of mass fluctuations much larger than the E/c² you'd calculate from the local electromagnetics, via gravitational interaction with distant matter.  It's supposed to conserve momentum via that same interaction.

(Usual caveat: I haven't yet satisfied myself that Woodward's derivation is valid and correctly interpreted.  I'm working on it.)

They're the same thing.  They both gravitate and have inertia.  The scale is wildly different, but that's immaterial.
http://en.wikipedia.org/wiki/Nordtvedt_effect

http://en.wikipedia.org/wiki/Equivalence_principle

Also note that the Nordtvedt effect has not been observed, despite multiple attempts.

Quote
They are not the same thing in our universe.

http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

Quote
Remember that mass is constrained over space and energy is constrained over time!

Perhaps you should rephrase this, because right now it makes no sense.

Quote
Also remember that a polarized cap and a unpolarized cap DO FALL at exactly the same rate.

That's because this:
Quote
Rest Mass and Inertial Mass being different

is forbidden by the Einstein Equivalence Principle.  A charged capacitor weighs more, but that gives it more inertia, so the increased force of gravity doesn't result in any extra acceleration.

Quote
I bet if Woodward put his "symmetrically shaped in the direction of desired thrust" devices in a conical faraday cage, it probably would work.

Woodward's devices already work.  Repeatably, well above the noise floor, in vacuum, with what appear to be rigorous experimental controls, and to within an order of magnitude of a priori thrust predictions.

I know Ron said thrust predictions are not made.  He was wrong.  There's a fairly recent derivation that includes the bulk acceleration requirement explicitly and contains an assumption or two regarding the properties of the material, and it shows surprisingly good quantitative agreement with experiment.

Though I have the impression that Woodward's group treats this thrust equation more as a curiosity than a falsifiable prediction, because there are still too many loose variables...

I'm also assuming it is safe to say that Gravitational Mass can never be separated from Rest Mass, that they are invariant. I think it is safe to say that indeed gravitational self energy does indeed contribute to inertial mass, and that may not be the only thing or the only way which in which mechanisms contributes to inertial mass, in our universe, either way gravitational self energy DOES. Verified by experiment.

What exactly do you mean by "verified by experiment"?

And what do you mean by "safe"?  You're essentially postulating the opposite of the Nordtvedt effect, and of course a blatant violation of the strong equivalence principle (which BTW Woodward's theory supposedly respects, being based on GR; I haven't yet got my head around how exactly it manages this).

I know I must have made some grave mistakes in this because I am tired and don't know everything. I'm certain I made a logical paradox somewhere. Either way here's my thoughts:

I want to make sure you are properly separating terms before you read and interpret my posts. My quote's actual words got dropped somehow from your quote and were changed a bit by Frobicat, but my exact words was, "If this really is Woodward's assumption. We can put it to bed. We just discussed this. I find it hard to believe he has confused mass energy within the atom with energies of covalent bonds."

So lets define clear terms and differences between them:

Rest Mass: Derived from inside the the protons and neutrons by virtue of their interaction with the Higgs mechanism, add that to the mass derived from the gluons, and take that whole system's movement through space time; finally you get rest mass. The gluons account for 99 percent of the mass of a proton, not the quarks. Color confinement.Same thing in the neutron. Not derived from the electrons. The electrons hang around because of charge, not attraction to the atom's rest mass. The mass of an individual electron is so small, that any gravitational interaction between it and the nucleus is basically zero. The charge force is way stronger. In short, the rest mass, which is the mass/energy of the atom, which results in gravity, is confined to the nucleus. Active gravitational mass is the result.

Self energy: Not the same as rest mass. To have any self energy, the particle must interact with something else in it's environment. You can have different types of self energy.

Self energy contained within the bonds between atoms in a molecule for example, covalent bonds.
You can have chemical energy self energy
Heat self energy.
You can also have gravitational self energy.

Keep these terms separate. Those two forms of self energy are not on the same scale and not related.

Gravitational self energy contributes to a system's gravitational mass AND it's inertial mass.
Electrical/mechanical self energy does not contribute to a system's gravitational mass or it's inertial mass.

Time to really nuke this:

Is gravitational self energy the same as active gravitational mass? no
-A tiny moon and a large moon both would fall toward the earth at the same rate. Even though they are of different masses. Like the hammer and feather. true
-Do you need an environment to have active gravitational mass? no
-Mass arises mostly from the energy stored in gluon coupling. I know of no interaction of gluons with Higgs.
-Do gluons derive their mass from Higgs? no
-Do gluons need an environment in order to have mass? kinda but no, no because of precise language (Bill Clinton method)
The environment for the gluon is within the quark, outside the sphere of gravitational self interaction with other particles because it is overwhelmed by the strong force. So environment in this context doesn't fit with other times environment was brought up.
-Is the bulk of active gravitational mass derived from the higgs mechanism? no
-You don't need an environment to interact with in order to have active gravitational mass. true
-You need an environment to have self energy. true
-You can have self energy without an environment. false

Is gravitational self energy the same as passive gravitational mass? yes they are complimentary, you can't have one without the other
-Self energy is result of changes that objects themselves causes in the environment. true
-Must you have an environment to have gravitational self energy? yes
-Must you have an environment to have passive gravitational mass? yes
-Would either gravitational self energy or passive gravitational mass cease to exist outside an environment of peers? yes
In short self energy is evident because of the interaction of an object with its environment.
Passive gravitational mass can't arise without an environment to interact with.

Inertial mass is the mass of an object measured by its resistance to acceleration.
-Do you need an environment to say you accelerated? yes. A reference frame with respect to another has no meaning without an environment of things. Without an environment, there is only one observer and that observer is inertial, not accelerating with respect to anything else because there isn't anything else.

Is gravitational self energy a cause for inertial mass? yes
-Is gravitational self energy an acceleration? yes
-Do you need an environment to say you accelerated? yes
-Do you need an environment to have gravitational self energy? yes
-Do objects with gravitational self energy resist acceleration? yes
-Do objects with gravitational self energy have inertial mass? yes

Is passive gravitational mass a cause for inertial mass? yes
-Do objects with gravitational self energy have inertial mass? yes
-Do objects with passive gravitational mass resist acceleration? yes

Is mass energy a cause for inertia? yes
-Can you have acceleration without mass? no. What is to accelerate? You can't accelerate nothing.
-Is a massive object undergoing NO acceration experiencing inertia? no
-Do objects undergoing NO acceleration have inertial mass? NO

Is mass energy THE cause for inertial mass? NO
-Is mass energy responsible for 100% of inertial mass? no 99.?????percent. What is left is the .00001???? percent contribution to inertial mass from all the other fundamental interactions and their particles which have mass.

That tiny leftover bit is all we have left to play with because we can't shield gravity. We don't have the technology to get near those energy levels in our present day and we live in a universe that is dominated by inertial dominated by mass.

So we have to create a whole new universe within our real universe with slightly modified rules so we can get some work done by modifying inertia. This is what the shape of the emdrive does. It doesn't shield gravity and make the gravitational effects of inertia and more of less strong within the cavity. It gives the small percentage left, the .0000???? left a boost. So when we fire photons through the thing from small to large end, they gain inertial mass across the length of the cavity. Normally this would be equaled out and canceled in our universe because spacetime is symmetrical. But in the tubes universe, spacetime is not symmetrical. There is a bias.

Do objects of the same mass undergoing different accelerations have the same inertial mass? no
-Does it hurt more dropping a bowling ball on your foot than it does a marble? yes
-Did they fall at the same rate? yes
-Did they resist acceleration equally? acceleration yes, deceleration no
They weight differently but fell at the same speed. The force it takes you to move them though is different.

Is mass inertia? no
-Can you have mass without acceleration? yes
-Can you have inertia without acceleration? no

This is also the equivalence principal:
Inertial Mass: Assumed to be the same as gravitational mass by the equivalence principal. (Yeah I assume it is the same MOST of the time.

Where there is a gravitational field, they are the same. In areas where there are very low gravitational accelerations, this has been theorized to fall apart.)

Gravitational self energy contributes to a system's gravitational mass AND it's inertial mass. This was tested by the Nordtvedt effect and the Nordtvedt effect was ruled out. Which isn't an effect because it was ruled out. The Nordtvedt effect is a failed test of the equivalence principal.

Gravitational mass/inertial mass/gravitational self energy are accepted as the equivalent in our universe MOST of the time and is really illusory. Inertial mass can be modified (I support and others theorize) by a few different ways, 1 at the edges of galaxies and 2 by virtue of the shape of the emdrive.)

Why rest mass is not the same as gravitational mass and inertial mass. This is because contributions to the REST mass of an atom, create an energy instability between the nucleus and the orbiting electrons, this gets radiated away because the atom must return to it's lowest possible energy state. When you excite an atom, its electrons jump to higher energy levels briefly and then radiate a photon and return to normal.

When a molecular system is charged up, like in a dielectric, the self energy of the entire system increases as long as charge is maintained, meanwhile the rest masses of the individual atoms stay the same. The nucleus of the atoms was never altered. A dielectric at rest just charges up and doesn't gain weight/gravitational mass/inertial mass, none of that. Just electrical self energy.

"Dr. Woodward maintains that the M-E's mass fluctuations occur in the "squishy" intermolecular chemical bonds of the dielectric and not in the rest mass of the ions in question." http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=2949&start=240#p116102 I saw Paul March

saying the same thing over at Polywell. It don't make sense Woodward would say that, but I keep finding that is indeed what he is saying everywhere I look.

Accelerate a dielectric, the rest mass would raise. ANYTHINGS rest mass will increase if it is accelerated.

Woodward has it very wrong in this respect. The other respect being classical mechanical conservation laws.

What is left, which doesn't fit in with the above is electrical self energy, or you can call it self energy via polarized atoms.
Self energy of molecules is not the same as self energy of an atom. One is rest mass, the other is covalent bonds. Any gravitational effects relating to any raise in electrical/charge self energy is insignificant because at atomic and molecular scales, the strong, weak, and em force overwhelms gravity. So if an atom gains a bit of rest mass somehow for a split second from a more energetic orbiting electron, it makes no difference because gravity is weak at that level and the atom would radiate that mass/energy away. The electrical energy dumped into a dielectric via rf or an oscillator doesn't have enough energy to raise the mass energy of the atomic nucleus. This is the realm of gamma rays. A gamma way could and does cause atomic nuclei to emit energy in the response of an imbalanced gain in mass/energy from the energetic gamma ray. See more about pair production. This is why the Woodward effect isn't working based off of self energy.

The Woodward devices and the emdrive are very similar. The difference being is the Woodward devices are using capacitors or piezoelectric materials, between piezoelectric materials. He has used caps and PZTs in the middle. The MET is not contained within a cavity. Emdrive uses a dielectric in a cone or tube. I'm gonna discuss the cap in the middle approach first. He says he is generating a mass fluctuation in the capacitor material by virtue of rapidly squeezing and contracting it, producing a bias in the self energy of the cap. Two things we must be very clear we are precise about: 1. What kind of mass is he referring to by saying "mass fluctuations." It can't be rest mass.

See way above. I'm going to hedge he means inertial mass since inertial mass is the key to all the devices. 2. Which direction is the bias and with respect to what? Let's look at that. These piezoelectrics oscillate by physically changing dimensions creating a force in both directions of oscillation. Depending on how the PZT material are arranged and charged, it would push cap together towards its own center equally, or they could push it to the right, or the left, whatever. It would never ever work if the cap was being biased toward it's own center, so lets drop that one. We want it to be a thruster, not a cap smoosher. So let's say the PZTs net effect is to push the cap to the right for instance. This is easy to do. More pzt stacks on the left vs the right would do that. But we don't have thrust.

Because the inertial potential in the system is equal in all directions by virtue of the universe we live in. Now we have to analyze the MET thruster as a physical system. Since inertia is smooth everywhere (at least here on earth), the impulse of the cap that was pushed right by the imbalanced PZT stack would seem to violate conservation of momentum if this was the end of the story. Those PZT stacks push in 2 directions. Since this is a physical system, the net effect is that the push/pull forces cancel out. The only way to get a net thrust out of it is to decouple it from the universe, governed by the LAWS of physics. The best he could do is make it spin, a motor. A motor spins as a response of an imbalance in order to conserve momentum, and obey physical laws. A motor can't help us in space.

The pzt in the center in place of the cap is similar, only it is charged out of phase with the other pzt stacks, inducing a net bias, but since they are all part of the same physical system and connected to eachother, the push pull forces cancel out. Every item in the thruster has the same laws of physics to obey. They all posess the same inertial mass, which is derived from the universe at large which the thruster resides in. The best he can do is make it spin, converting linear motion to angular motion.

When I say physical system, consider there are 2 separate and invariably linked physical systems to consider here:

1. The thruster is a physical system. It must obey its own rules and the rules of the second physical sytem; the universe.
2. The universe.

The atoms, particles, radiative fields are spherical. The charge is spherical, the energy density of an atom is spherical. Every interation that has symmetry also has a conservation. This is where we derive our conservation laws. You can't break them. If they were broken, the universe itself would become immaterial. The fundamental interactions would be broken. Anything with mass has an unbreakable spacial symmetry that must be conserved. Anything with energy has a temporal asymmetry, which is time. The arrow of time is no accident and thermodynamics are no accident. We can't break the laws of physics and still exist.

The Woodward effect is trying to connect electromechanical self energy with inertial mass and gravitational self energy. That does not follow. There is no accepted theory of electrogravity. There is no mechanogravity.

In a previous post I commented on this and said I was looking for "X" effect define this concept. X was the Woodward effect. The Woodward effect can never be true in our universe, just like the Nordtvedt effect can never be true either.

Place the MET thruster in a container, like the cone shape and you are in business. We can't shield gravity by any means I know of, even a cone or other engineered boundary condition, so if inertial mass is really mostly or completely derived from the gravitational interaction of distant matter, we are up a s#$t creek on emdrive. It will never work. If it is casimir/unruh/zpf/EM we're in business, even if it is part gravity and part casimir/unruh/zph/em whatever. This is why I poo poo Wheeler-Feynman absorber theory. Gravity propagates at C. Retarded and advanced waves in WFA theory seem like a forced answer to explain Mach in terms of inertial mass's connection to gravity. The violations of causality in WFA theory need addressing because most mass arises at the quark/gluon level, which the field is contained to a very small area in a proton/neutron. WFA theory isn't addressing gravity waves, it is addressing electromagnetic waves. We already know that gravity isn't electromagnetic and no gravity waves have been detected. There is no salient mechanism I can find for the gravity of a distant object to inform the inertia of a local object using solely the terms we know of gravity, which are spacetime curvature, or if you want to believe in quantum gravity, gravitons. Find me a graviton or a gravity wave and WFA is back on the table. That also means emdrive would be done because we can't shield gravity. We can't create an asymmetry in gravity to play with. WFA theory falls apart in other ways too.

He mentioned he placed his thrusters inside a faraday cage. It seems this was to eliminate unwanted interference, so probably rectangular. The geometry of the faraday cage is what could make it work.




/Book
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/07/2014 02:07 pm
Ron, you said DC couldn't explain the thrust (and Rodal said that was very helpful information).  But the DC in this case is being fed into an RF oscillator, which would seem to change the picture a bit, no?
Yes.  I misunderstood the operation and thought they were talking about the Cannae device which I'm not that familiar with.  Seems both resonators are being driven by AC, so both could be using M-E if they both have dielectrics inside.

When Paul was first working with the Shawyer resonator back in 2007, we went through the issues pretty carefully and found that indeed, when there is nothing inside the resonator, it cannot be using M-E physics since there needs to be a mass to fluctuate.  Looks though, that they've left the empty resonator design behind since it doesn't work.  Odd thing is, both Shawyer and his misunderstanding of "group velocity" and White and his misunderstanding of vacuum fluctuations require nothing inside these resonators.  So why are they putting the stuff in?

I think the mystery meat must be from Boeing.  I'm betting what we haven't been hearing about are the results from Hector Serrano and his asymmetric dielectric capacitor thruster.  Serrano had his stuff tested at Marshall twice over the years, and couldn't get a response from NASA despite some thrust.  (They did however, file for patent on Serrano's design--scumbag NASA folks.)  If Serrano eventually got picked up by Boeing, and Boeing sent what they had to Eagleworks, and Sonny was claiming his QVF model explains thrust from yet another thruster, that would explain why they're sticking dielectric inside all the designs.  What Sonny doesn't explain is why they need dielectric at all, since the QVF conjecture does not require any mass to generate quantum fluctuations, and why these things don't work with DC, which is what the QVF conjecture is all about.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/07/2014 02:21 pm
If that is the case then almost all the RF power is concentrated in this resonator and is not bouncing off any of the walls.    The question is how is this resonator excited?  That information is missing from the paper.
The walls of the cone are indeed the resonator.  EM is in a standing wave between the two ends.  That is the design Shawyer started with and there's no reason to keep the asymmetry apart from this.  Including a dielectric allows one to have higher power densities, so if Sonny is now pretending he can alter the rate of quantum vacuum fluctuation, this could be the issue.  And I would note to you, he has made statements this nutty before.  When the resonator didn't work back in 2007, he first claimed that the fluctuations had been "choaked off", which is just more malarkey.  Vacuum fluctuations do not care how much mass is present.

Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 02:24 pm
When Paul was first working with the Shawyer resonator back in 2007, we went through the issues pretty carefully and found that indeed, when there is nothing inside the resonator, it cannot be using M-E physics since there needs to be a mass to fluctuate.  Looks though, that they've left the empty resonator design behind since it doesn't work.  Odd thing is, both Shawyer and his misunderstanding of "group velocity" and White and his misunderstanding of vacuum fluctuations require nothing inside these resonators.  So why are they putting the stuff in?..
To confuse matters even more, the AviationWeek/WiredUK reporter http://forum.nasaspaceflight.com/index.php?topic=29276.msg1265607#msg1265607) posted here a few pages back that he/she has an e-mail from Shawyer stating that Shawyer no longer uses a dielectric resonator inside his EM drive

I think the mystery meat must be from Boeing.  I'm betting what we haven't been hearing about are the results from Hector Serrano and his asymmetric dielectric capacitor thruster.  Serrano had his stuff tested at Marshall twice over the years, and couldn't get a response from NASA despite some thrust.  (They did however, file for patent on Serrano's design--scumbag NASA folks.)  If Serrano eventually got picked up by Boeing, and Boeing sent what they had to Eagleworks, and Sonny was claiming his QVF model explains thrust from yet another thruster, that would explain why they're sticking dielectric inside all the designs. 
The NASA Eagleworks tests of the Serrano Field Effect Boeing/DARPA device show [excerpt from slide 40 of Dr. White's presentation attached below] an impulse (very short -less than 1 sec- response) instead of a steady thrust force.  Given

A) the low thrust forces involved (20 to 110 microNewtons)(in comparison with conventional means of propulsion), and
B) an impulse response but no steady state thrust,

can this kind of EM drive be scaled-up to enable the performance (9 month trips to Titan and Enceladus) envisioned at the end of Brady et.al.'s report?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/07/2014 02:32 pm
The Woodward effect is trying to connect electromechanical self energy with inertial mass and gravitational self energy.
No offense, but you really should not write these fantastically long posts devoted to critiquing a theory you haven't read.  You have no way to know whether what you're criticizing is actual theory.  I can tell you, all of your comments about conservation are completely wrong, and you would know this if you had read the book.  You should not be arguing that Woodward is supposedly trying to do this or that, when you have not read his work.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/07/2014 02:41 pm
The Woodward effect is trying to connect electromechanical self energy with inertial mass and gravitational self energy.
No offense, but you really should not write these fantastically long posts devoted to critiquing a theory you haven't read.  You have no way to know whether what you're criticizing is actual theory.  I can tell you, all of your comments about conservation are completely wrong, and you would know this if you had read the book.  You should not be arguing that Woodward is supposedly trying to do this or that, when you have not read his work.

I find it is best to try and break people's theories and find better ones. Then try to break those too. Not to fall in love with an idea that might not work, and hinder progress.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/07/2014 02:44 pm
Given Woodward's assertions about exciting an oscillation in a dielectric and then pushing on it at an opportune time to move forward clearly does violate conservation of momentum.

If I'm not gravely mistaken, Woodward's theory is supposed to involve excitation of mass fluctuations much larger than the E/c² you'd calculate from the local electromagnetics, via gravitational interaction with distant matter.  It's supposed to conserve momentum via that same interaction.

Mulletron does not seem to acknowledge the "gravitational interaction with distant matter" part.  In fact, that has not yet been discussed all that much (or at least to my satisfaction and education).  "That" being, the definition of inertia thing suggested by Mach and Sciama.  Solo dicendo, on that.

Quote from: 93143
They're the same thing.  They both gravitate and have inertia.  The scale is wildly different, but that's immaterial.
http://en.wikipedia.org/wiki/Nordtvedt_effect

http://en.wikipedia.org/wiki/Equivalence_principle

Also note that the Nordtvedt effect has not been observed, despite multiple attempts.

I still object to 93143's take because the scale is so "wildly different".  The energy in a covalent bond is far smaller than the rest mass energy in the atom's nucleus.  On one level, a rubber band powerd balsawood airplane is the same thing as a C-5 Galaxy, but it would be unwise for our military to confuse the difference in scale.

But I also think Mulletron is premature to rest his argument on the one cite; note that the oracle has very little info on the Norbert effect (http://www.youtube.com/watch?v=NJhGfjW1-fA).  It is by no means settled science.

Quote from: Mulletron
They are not the same thing in our universe...

Rest mass energy and covalent bond energy are not the same thing.

[Pre-posting edit:

I just noticed that Mulletron has addressed 93143's comment here: 

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1267489#msg1267489 ]


Quote from: Mulletron
Remember that mass is constrained over space and energy is constrained over time!

Quote from: 93143
Perhaps you should rephrase this, because right now it makes no sense.

Well my take on that is that mass is energy bound in the tiny geometrical confines of a particle on the one hand. OTOH, energy, loosely speaqking, blobs out over space at a rate; and a rate is an acknowledgement of time.

I want to be careful not to get too "tit-for-tat' here, but one more comment:

I'm also assuming it is safe to say that Gravitational Mass can never be separated from Rest Mass, that they are invariant. I think it is safe to say that indeed gravitational self energy does indeed contribute to inertial mass, and that may not be the only thing or the only way which in which mechanisms contributes to inertial mass, in our universe, either way gravitational self energy DOES. Verified by experiment.

Quote from: 93143
What exactly do you mean by "verified by experiment"?

He means this.  Right now, gravitational and inertial mass appear to be the same thing, but he allows that may not be true, because there might be other mechanisms discovered which would have to be verified by experiment.

Quote from: 93143
And what do you mean by "safe"?

"Safe" in the sense that, should you provide calcs assuming gravitational and inertial mass to be the same value, your calcs would not be falsifiable, to date, on that basis.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/07/2014 02:47 pm
The MCL amplifier used is a Class AB amp.   The output, unless it has a DC blocking cap inside the amp, will have a DC offset = Vdd/2.   My guess is the amp does not have a DC blocking cap because that would affect the bandwidth and MCL likes to advertise their amplifiers as being broadband.

In an earlier setup, they used a Carvin DCM-1000 amp.  Is this pertinent to your argument?  See the attached PPT, p20.

the theory of this device has something to do with its cone shape.   But as an RF device it is a cavity filter.   It is also a Faraday cage because the inside is all Cu.

Nobody here has seen the inside of this device.  It may be full of compressed hummingbird wings, for all we know.  Or a vial of ebola.  Solo dicendo.

[Sorry.  The Inappropriate Humor Department (IHD) sneaks those in from time to time.]

Seriously, what's inside the cupric conical device?
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 02:50 pm
...White and his misunderstanding of vacuum fluctuations require nothing inside these resonators.  So why are they putting the [dielectric] stuff in?...
Very good question.  Since Dr. White or his staff are not involved in this thread, let me try an answer for him: they would probably state that the dielectric resonator functions as a resonator for millimeter-wavelength radio waves.   At the resonant frequencies, the microwaves form standing waves in the resonator, oscillating with large amplitudes. The resonant frequency is determined by the overall physical dimensions of the resonator and the dielectric constant of the material.

So, he would state that the dielectric resonator functions similarly to the cavity resonator, except that the radio waves are reflected by the large change in permittivity rather than by the conductivity of metal. At millimeter wave frequencies, metal surfaces become lossy reflectors, so dielectric resonators are used at these [shorter wavelength] frequencies.  So, effectively Dr.White would state that the dielectric resonator replaces the cavity at these smaller wavelengths.  The cavity's purpose is for resonance at the longer wavelengths, and the dielectric resonator is resonance at the millimeter wavelengths.  Since he is using both a cavity and the dielectric resonator, he must have been unsure as to which wavelength was the important one to resonate.  Similarly in the detection for axions in the ADMX experiment it was not clear at what wavelength they will find axions.  They started the ADMX experiment at longer wavelengths and now they are exploring shorter wavelengths.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/07/2014 02:53 pm
The Woodward effect is trying to connect electromechanical self energy with inertial mass and gravitational self energy.
No offense, but you really should not write these fantastically long posts devoted to critiquing a theory you haven't read.  You have no way to know whether what you're criticizing is actual theory.  I can tell you, all of your comments about conservation are completely wrong, and you would know this if you had read the book.  You should not be arguing that Woodward is supposedly trying to do this or that, when you have not read his work.


I find it is best to try and break people's theories and find better ones. Then try to break those too. Not to fall in love with an idea that might not work, and hinder progress.
Okay.  Heh!  But do read the book.  It's a fun read!
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/07/2014 02:59 pm
So lets define clear terms and differences between them:

...
Do gluons need an environment in order to have mass? kinda but no, no because of precise language (Bill Clinton method)
...


Which is an excellent mixture of physics and politics.  Plus:  Even Socrates could understand your line of questioning!

Whoah, there kemosabe:  What?

Quote from: Mulletron
Do objects undergoing NO acceleration have inertial mass? NO

This one's not going to be easy to prove.  If I assume that the universe revolves (or pulsates, or expands, or whatever) around me, then I have no inertia. Fine, but that's probably not the case.

Show me ANY object or particle NOT undergoing some kind of acceleration.

Quote from:
ulletron
So we have to create a whole new universe within our real universe with slightly modified rules so we can get some work done by modifying inertia. This is what the shape of the emdrive does. It doesn't shield gravity and make the gravitational effects of inertia and more of less strong within the cavity. It gives the small percentage left, the .0000???? left a boost. So when we fire photons through the thing from small to large end, they gain inertial mass across the length of the cavity. Normally this would be equaled out and canceled in our universe because spacetime is symmetrical. But in the tubes universe, spacetime is not symmetrical. There is a bias.

My bold.  That's what they say, sure.  It's an extraordinary claim to think that a "new" universe" can be created, with its own laws, for such a small expenditure of energy and mass.

Totally great post.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/07/2014 02:59 pm
...White and his misunderstanding of vacuum fluctuations require nothing inside these resonators.  So why are they putting the [dielectric] stuff in?...
Very good question.  Since Dr. White or his staff are not involved in this thread, let me try an answer for him: they would probably state that the dielectric resonator functions as a resonator for millimeter-wavelength radio waves.   At the resonant frequencies, the microwaves form standing waves in the resonator, oscillating with large amplitudes. The resonant frequency is determined by the overall physical dimensions of the resonator and the dielectric constant of the material.

So, he would state that the dielectric resonator functions similarly to the cavity resonator, except that the radio waves are reflected by the large change in permittivity rather than by the conductivity of metal. At millimeter wave frequencies, metal surfaces become lossy reflectors, so dielectric resonators are used at these [shorter wavelength] frequencies.  So, effectively Dr.White would state that the dielectric resonator replaces the cavity at these smaller wavelengths.  The cavity's purpose is for resonance at the longer wavelengths, and the dielectric resonator is resonance at the millimeter wavelengths.
I'm lost.  They're powering with <2Ghz.  How are they getting millimeter waves (30-300Ghz) and if that's what they wanted, why would they not just use a millimeter wave amp?  I've sent Paul links to dozens of them over the years.

To I would note that very few materials have ionic responses in the millimeter wave range.  So there wouldn't be much if any bulk acceleration at these frequencies.
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 03:14 pm
...White and his misunderstanding of vacuum fluctuations require nothing inside these resonators.  So why are they putting the [dielectric] stuff in?...
Very good question.  Since Dr. White or his staff are not involved in this thread, let me try an answer for him: they would probably state that the dielectric resonator functions as a resonator for millimeter-wavelength radio waves.   At the resonant frequencies, the microwaves form standing waves in the resonator, oscillating with large amplitudes. The resonant frequency is determined by the overall physical dimensions of the resonator and the dielectric constant of the material.

So, he would state that the dielectric resonator functions similarly to the cavity resonator, except that the radio waves are reflected by the large change in permittivity rather than by the conductivity of metal. At millimeter wave frequencies, metal surfaces become lossy reflectors, so dielectric resonators are used at these [shorter wavelength] frequencies.  So, effectively Dr.White would state that the dielectric resonator replaces the cavity at these smaller wavelengths.  The cavity's purpose is for resonance at the longer wavelengths, and the dielectric resonator is resonance at the millimeter wavelengths.
I'm lost.  They're powering with <2Ghz.  How are they getting millimeter waves (30-300Ghz) and if that's what they wanted, why would they not just use a millimeter wave amp?  I've sent Paul links to dozens of them over the years.

To I would note that very few materials have ionic responses in the millimeter wave range.  So there wouldn't be much if any bulk acceleration at these frequencies.
Well they wrote a lengthy report with lots of pictures of a vacuum chamber, description of a vacuum chamber and in the end they did not conduct the experiments in the vacuum chamber [and their explanation is because of the electrolytic capacitors?].  Maybe eventually they were planning to go over 30 GHz using a different amplifier ?

They tried removing the dielectric resonator from the truncated cone and they measured no thrust without the dielectric resonator. They offer no theoretical explanation for why the dielectric resonator plays such an important role in their results at ~2 GHz

They do not state what dielectric resonator material they used for the truncated cone experiments.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/07/2014 03:29 pm
...White and his misunderstanding of vacuum fluctuations require nothing inside these resonators.  So why are they putting the [dielectric] stuff in?...
Very good question.  Since Dr. White or his staff are not involved in this thread, let me try an answer for him: they would probably state that the dielectric resonator functions as a resonator for millimeter-wavelength radio waves.   At the resonant frequencies, the microwaves form standing waves in the resonator, oscillating with large amplitudes. The resonant frequency is determined by the overall physical dimensions of the resonator and the dielectric constant of the material.

So, he would state that the dielectric resonator functions similarly to the cavity resonator, except that the radio waves are reflected by the large change in permittivity rather than by the conductivity of metal. At millimeter wave frequencies, metal surfaces become lossy reflectors, so dielectric resonators are used at these [shorter wavelength] frequencies.  So, effectively Dr.White would state that the dielectric resonator replaces the cavity at these smaller wavelengths.  The cavity's purpose is for resonance at the longer wavelengths, and the dielectric resonator is resonance at the millimeter wavelengths.  Since he is using both a cavity and the dielectric resonator, he must have been unsure as to which wavelength was the important one to resonate.  Similarly in the detection for axions in the ADMX experiment it was not clear at what wavelength they will find axions.  They started the ADMX experiment at longer wavelengths and now they are exploring shorter wavelengths.

Are you thinking 30GHz ?

Yup, I guess you are !
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 03:36 pm
...White and his misunderstanding of vacuum fluctuations require nothing inside these resonators.  So why are they putting the [dielectric] stuff in?...
Very good question.  Since Dr. White or his staff are not involved in this thread, let me try an answer for him: they would probably state that the dielectric resonator functions as a resonator for millimeter-wavelength radio waves.   At the resonant frequencies, the microwaves form standing waves in the resonator, oscillating with large amplitudes. The resonant frequency is determined by the overall physical dimensions of the resonator and the dielectric constant of the material.

So, he would state that the dielectric resonator functions similarly to the cavity resonator, except that the radio waves are reflected by the large change in permittivity rather than by the conductivity of metal. At millimeter wave frequencies, metal surfaces become lossy reflectors, so dielectric resonators are used at these [shorter wavelength] frequencies.  So, effectively Dr.White would state that the dielectric resonator replaces the cavity at these smaller wavelengths.  The cavity's purpose is for resonance at the longer wavelengths, and the dielectric resonator is resonance at the millimeter wavelengths.  Since he is using both a cavity and the dielectric resonator, he must have been unsure as to which wavelength was the important one to resonate.  Similarly in the detection for axions in the ADMX experiment it was not clear at what wavelength they will find axions.  They started the ADMX experiment at longer wavelengths and now they are exploring shorter wavelengths.

Are you thinking 30GHz ?
Yes, not clear what was in their mind.  Just like they wrote a lengthy report with lots of pictures of a vacuum chamber, description of a vacuum chamber and in the end they did not conduct the experiments in the vacuum chamber [and their explanation is because of the electrolytic capacitors?].

If the purpose was just to test at room pressure operating conditions they would have been much better off using an oil-damped Cavendish type of balance, yet they started a program with a magnetically damped inverted pendulum that could fit inside their small vacuum chamber. But in the end they did not use their vacuum chamber.

 Maybe eventually they were planning to go over 30 GHz using a different amplifier ?

They tried removing the dielectric resonator and perhaps they were surprised (?) to find out they measured no thrust whatsoever. They offer no theoretical explanation for this. It is though, an experimental fact we have to understand and explain: the paramount role of the dielectric resonator at ~2 GHz
Title: Re: EM Drive Developments
Post by: Mulletron on 10/07/2014 03:56 pm
Quoting myself here: "Remember that mass is constrained over space and energy is constrained over time!"

This isn't any new insight I have. Nothing I throw around are my own insight, except the mistakes I make.

Here's what I mean though:

Mass over symmetric space, energy over asymmetric time. Matter is just energy constrained over time that has a high probability of being there occupying a point in space. Particles in the vacuum have a low probability of being there, because they pop in and out of existence so quickly. Because of that, forces associated with mass such as momentum, acceleration, have to be conserved. Momentum, inertia, acceleration are also constrained in space. This also gives us an arrow of time to follow over spacetime.  The closer you get to C, this breaks down.

I can go up, down, left or right. I push something up, I get pushed right back down. I can only go forward in time. Anything that has a symmetry also has and associated conservation. Until the symmetry is broken.
Title: Re: EM Drive Developments
Post by: aero on 10/07/2014 03:56 pm
Question - Is there any way to know the shapes of the standing waves within the cavity, with and without the resonator?
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 04:00 pm
Question - Is there any way to know the shapes of the standing waves within the cavity, with and without the resonator?
See here for a curved truncated cone:  http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html
for the cavity itself (not the dielectric resonator)


Observe that the ends, however are not flat in this solution for 1/r not equal to zero.  Shawyer's and NASA truncated cone have flat ends with 1/r = 0 (r-> Infinity at ends)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/07/2014 04:02 pm
...White and his misunderstanding of vacuum fluctuations require nothing inside these resonators.  So why are they putting the [dielectric] stuff in?...
Very good question.  Since Dr. White or his staff are not involved in this thread, let me try an answer for him: they would probably state that the dielectric resonator functions as a resonator for millimeter-wavelength radio waves.   At the resonant frequencies, the microwaves form standing waves in the resonator, oscillating with large amplitudes. The resonant frequency is determined by the overall physical dimensions of the resonator and the dielectric constant of the material.

So, he would state that the dielectric resonator functions similarly to the cavity resonator, except that the radio waves are reflected by the large change in permittivity rather than by the conductivity of metal. At millimeter wave frequencies, metal surfaces become lossy reflectors, so dielectric resonators are used at these [shorter wavelength] frequencies.  So, effectively Dr.White would state that the dielectric resonator replaces the cavity at these smaller wavelengths.  The cavity's purpose is for resonance at the longer wavelengths, and the dielectric resonator is resonance at the millimeter wavelengths.  Since he is using both a cavity and the dielectric resonator, he must have been unsure as to which wavelength was the important one to resonate.  Similarly in the detection for axions in the ADMX experiment it was not clear at what wavelength they will find axions.  They started the ADMX experiment at longer wavelengths and now they are exploring shorter wavelengths.

Are you thinking 30GHz ?
Yes, not clear what was in their mind.  Just like they wrote a lengthy report with lots of pictures of a vacuum chamber, description of a vacuum chamber and in the end they did not conduct the experiments in the vacuum chamber [and their explanation is because of the electrolytic capacitors?].

If the purpose was just to test at room pressure operating conditions they would have been much better off using an oil-damped Cavendish type of balance, yet they started a program with a magnetically damped inverted pendulum that could fit inside their small vacuum chamber. But in the end they did not use their vacuum chamber.

 Maybe eventually they were planning to go over 30 GHz using a different amplifier ?

They tried removing the dielectric resonator and perhaps they were surprised (?) to find out they measured no thrust whatsoever. They offer no theoretical explanation for this. It is though, an experimental fact we have to understand and explain: the paramount role of the dielectric resonator at ~2 GHz

Dielectrics can  have very interesting (weird) responses vs frequency which are caused by individual dipole elements passing through resonance.  These are all material related, but in general, the dielectric constants decrease w/ frequency except at these resonance points.  Artificial resonators are used to construct metamaterials of engineered characteristics.

Oh, and they aren't necessarily linear.
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 04:05 pm
...White and his misunderstanding of vacuum fluctuations require nothing inside these resonators.  So why are they putting the [dielectric] stuff in?...
Very good question.  Since Dr. White or his staff are not involved in this thread, let me try an answer for him: they would probably state that the dielectric resonator functions as a resonator for millimeter-wavelength radio waves.   At the resonant frequencies, the microwaves form standing waves in the resonator, oscillating with large amplitudes. The resonant frequency is determined by the overall physical dimensions of the resonator and the dielectric constant of the material.

So, he would state that the dielectric resonator functions similarly to the cavity resonator, except that the radio waves are reflected by the large change in permittivity rather than by the conductivity of metal. At millimeter wave frequencies, metal surfaces become lossy reflectors, so dielectric resonators are used at these [shorter wavelength] frequencies.  So, effectively Dr.White would state that the dielectric resonator replaces the cavity at these smaller wavelengths.  The cavity's purpose is for resonance at the longer wavelengths, and the dielectric resonator is resonance at the millimeter wavelengths.  Since he is using both a cavity and the dielectric resonator, he must have been unsure as to which wavelength was the important one to resonate.  Similarly in the detection for axions in the ADMX experiment it was not clear at what wavelength they will find axions.  They started the ADMX experiment at longer wavelengths and now they are exploring shorter wavelengths.

Are you thinking 30GHz ?
Yes, not clear what was in their mind.  Just like they wrote a lengthy report with lots of pictures of a vacuum chamber, description of a vacuum chamber and in the end they did not conduct the experiments in the vacuum chamber [and their explanation is because of the electrolytic capacitors?].

If the purpose was just to test at room pressure operating conditions they would have been much better off using an oil-damped Cavendish type of balance, yet they started a program with a magnetically damped inverted pendulum that could fit inside their small vacuum chamber. But in the end they did not use their vacuum chamber.

 Maybe eventually they were planning to go over 30 GHz using a different amplifier ?

They tried removing the dielectric resonator and perhaps they were surprised (?) to find out they measured no thrust whatsoever. They offer no theoretical explanation for this. It is though, an experimental fact we have to understand and explain: the paramount role of the dielectric resonator at ~2 GHz

Dielectrics can  have very interesting (weird) responses vs frequency which are caused by individual dipole elements passing through resonance.  These are all material related, but in general, the dielectric constants decrease w/ frequency except at these resonance points.  Artificial resonators are used to construct metamaterials of engineered characteristics.

Oh, and they aren't necessarily linear.
Yes, thank you.  That must be the explanation.  Unfortunately they did not specify the material that was used as a dielectric resonator for the truncated cone.  Perhaps we could consider the high likelihood of it being a ceramic, as proposed by @zen-in
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 04:27 pm
..
Dielectrics can  have very interesting (weird) responses vs frequency which are caused by individual dipole elements passing through resonance.  These are all material related, but in general, the dielectric constants decrease w/ frequency except at these resonance points.  Artificial resonators are used to construct metamaterials of engineered characteristics.

Oh, and they aren't necessarily linear.
And the experiments (see attached) show a very nonlinear response (a 6 fold increase in power input results in a decrease of thrust force of 10%, and an increase in frequency of 0.3% (practically the same frequency) results in 2.5 times higher Q and 1/2 the thrust force).

The copper does not have a nonlinear response.  The empty cavity does not have a nonlinear response.

What can be responsible for a nonlinear response?

The dielectric material of course
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/07/2014 04:29 pm
I think that's unlikely.  Paul has been looking at teflon for along time and probably because he is of the opinion that Woodward's and White's models form different sides of the same coin.  Paul believes both Woodward and White are correct.  Even though i can't agree, I would note that one logical response to this belief is to stick dielectric into a resonator to test Jim's theory.  Sonny would never do this--test Woodward's work--unless he had convinced himself he was testing his own model at the same time.  Teflon has a very poor k~2, but it is good up into microwave territory.  Most ceramics the k drops off way before.  In fact I only know of one that maintains it's high k to about 1 Ghz, and that is single crystal.  They are certainly not using that.

Probably just a teflon sheet, though if its there to check Woodward's theory, then it is installed with one side against one of the ends of the resonator chamber and would act in 1/4 wave fashion.
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 04:34 pm
I think that's unlikely.  Paul has been looking at teflon for along time and probably because he is of the opinion that Woodward's and White's models form different sides of the same coin.  Paul believes both Woodward and White are correct.  Even though i can't agree, I would note that one logical response to this belief is to stick dielectric into a resonator to test Jim's theory.  Sonny would never do this--test Woodward's work--unless he had convinced himself he was testing his own model at the same time.  Teflon has a very poor k~2, but it is good up into microwave territory.  Most ceramics the k drops off way before.  In fact I only know of one that maintains it's high k to about 1 Ghz, and that is single crystal.  They are certainly not using that.

Probably just a teflon sheet, though if its there to check Woodward's theory, then it is installed with one side against one of the ends of the resonator chamber and would act in 1/4 wave fashion.

Thanks, Ron as your post should motivate further reflection on what dielectric material NASA used for the truncated cone. Teflon was an initial assumption (just based on the fact that Teflon was the only dielectric material mentioned in the report, albeit for the Cannae drive).  We didn't have your additional arguments.

Let me add another argument: nonlinear response from Teflon (PTFE), particularly with Teflon exposed to an electric field ~ 45000 Volt/meter [Note this is based on back of the envelope calculations: not too different a field than from the maximum for the Cannae drive, NASA did not give the COMSOL numbers for the truncated cone electric field, particularly at the dielectric resonator]

Interested on what others  think about Ron's reasoning above for Teflon instead of a ceramic as the dielectric  for NASA's truncated cone.
Title: Re: EM Drive Developments
Post by: aero on 10/07/2014 05:02 pm
Question - Is there any way to know the shapes of the standing waves within the cavity, with and without the resonator?
See here for a curved truncated cone:  http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html
for the cavity itself (not the dielectric resonator)


Observe that the ends, however are not flat in this solution for 1/r not equal to zero.  Shawyer's and NASA truncated cone have flat ends with 1/r = 0 (r-> Infinity at ends)
Thanks. That's helpful, I think.

Edit - fixed the end quote.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/07/2014 05:11 pm
I think that's unlikely.  Paul has been looking at teflon for along time and probably because he is of the opinion that Woodward's and White's models form different sides of the same coin.  Paul believes both Woodward and White are correct.  Even though i can't agree, I would note that one logical response to this belief is to stick dielectric into a resonator to test Jim's theory.  Sonny would never do this--test Woodward's work--unless he had convinced himself he was testing his own model at the same time.  Teflon has a very poor k~2, but it is good up into microwave territory.  Most ceramics the k drops off way before.  In fact I only know of one that maintains it's high k to about 1 Ghz, and that is single crystal.  They are certainly not using that.

Probably just a teflon sheet, though if its there to check Woodward's theory, then it is installed with one side against one of the ends of the resonator chamber and would act in 1/4 wave fashion.

Thanks, Ron as your post should motivate further reflection on what dielectric material NASA used for the truncated cone. Teflon was an initial assumption (just based on the fact that Teflon was the only dielectric material mentioned in the report, albeit for the Cannae drive).  We didn't have your additional arguments.

Let me add another argument: I expect a more nonlinear response from Teflon (PTFE) than from a ceramic, particularly with Teflon exposed to an electric field ~ 45000 Volt/meter [Note this is based on back of the envelope calculations: not too different a field than from the maximum for the Cannae drive, NASA did not give the COMSOL numbers for the truncated cone electric field, particularly at the dielectric resonator]

Interested on what others  think about Ron's reasoning above for Teflon instead of a ceramic as the dielectric  for NASA's truncated cone.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700003017.pdf

???

The results of this investigation along with existing data at lower frequencies were used to verify the theoretically predicted transition which occurs in the microwave region and continues into the millimeter region.

see p 33 and esp p45 !!!
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 05:17 pm
I think that's unlikely.  Paul has been looking at teflon for along time and probably because he is of the opinion that Woodward's and White's models form different sides of the same coin.  Paul believes both Woodward and White are correct.  Even though i can't agree, I would note that one logical response to this belief is to stick dielectric into a resonator to test Jim's theory.  Sonny would never do this--test Woodward's work--unless he had convinced himself he was testing his own model at the same time.  Teflon has a very poor k~2, but it is good up into microwave territory.  Most ceramics the k drops off way before.  In fact I only know of one that maintains it's high k to about 1 Ghz, and that is single crystal.  They are certainly not using that.

Probably just a teflon sheet, though if its there to check Woodward's theory, then it is installed with one side against one of the ends of the resonator chamber and would act in 1/4 wave fashion.

Thanks, Ron as your post should motivate further reflection on what dielectric material NASA used for the truncated cone. Teflon was an initial assumption (just based on the fact that Teflon was the only dielectric material mentioned in the report, albeit for the Cannae drive).  We didn't have your additional arguments.

Let me add another argument: I expect a more nonlinear response from Teflon (PTFE) than from a ceramic, particularly with Teflon exposed to an electric field ~ 45000 Volt/meter [Note this is based on back of the envelope calculations: not too different a field than from the maximum for the Cannae drive, NASA did not give the COMSOL numbers for the truncated cone electric field, particularly at the dielectric resonator]

Interested on what others  think about Ron's reasoning above for Teflon instead of a ceramic as the dielectric  for NASA's truncated cone.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700003017.pdf

???

Great reference.  See page 45 for Teflon.  At 2Ghz it starts to get nonlinear, however this is at what amount of electric field and temperature?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/07/2014 05:24 pm
Something I was wondering late last night when I was thinking of cathode ray tubes and their shape. Who's to say that radio waves are even the best approach anyway? Considering the modes that are blocked out by the enclosed cavity of the cone shape; what exactly is being blocked? It would depend on the plasma frequency of the material. In any event, it leaves a gap in the electromagnetic spectrum. Picture it as a quiet zone in the vast noise of the EM spectrum. The device, I have said is working on casimir interaction informed by McCulloch et al. That means the modes being excluded are the ones we should be USING to excite the cavity. The spectral shape of the bands excluded is likely to be complex, as is the case with permittivity.

Anyone ever see a CRT shoot across the room?  :P

Does anyone have any idea how exactly the momentum from a photon can couple to a dielectric, like the Abraham-Minkowski controversy and how this relates to the refractive index of a material? I loosely grasp it honestly. I think the emdrive would work without the dielectric, but it would work BETTER with the dielectric.

Photo is a model for clarity.

Thoughts?



Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/07/2014 05:26 pm
I think that's unlikely.  Paul has been looking at teflon for along time and probably because he is of the opinion that Woodward's and White's models form different sides of the same coin.  Paul believes both Woodward and White are correct.  Even though i can't agree, I would note that one logical response to this belief is to stick dielectric into a resonator to test Jim's theory.  Sonny would never do this--test Woodward's work--unless he had convinced himself he was testing his own model at the same time.  Teflon has a very poor k~2, but it is good up into microwave territory.  Most ceramics the k drops off way before.  In fact I only know of one that maintains it's high k to about 1 Ghz, and that is single crystal.  They are certainly not using that.

Probably just a teflon sheet, though if its there to check Woodward's theory, then it is installed with one side against one of the ends of the resonator chamber and would act in 1/4 wave fashion.

Thanks, Ron as your post should motivate further reflection on what dielectric material NASA used for the truncated cone. Teflon was an initial assumption (just based on the fact that Teflon was the only dielectric material mentioned in the report, albeit for the Cannae drive).  We didn't have your additional arguments.

Let me add another argument: I expect a more nonlinear response from Teflon (PTFE) than from a ceramic, particularly with Teflon exposed to an electric field ~ 45000 Volt/meter [Note this is based on back of the envelope calculations: not too different a field than from the maximum for the Cannae drive, NASA did not give the COMSOL numbers for the truncated cone electric field, particularly at the dielectric resonator]

Interested on what others  think about Ron's reasoning above for Teflon instead of a ceramic as the dielectric  for NASA's truncated cone.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700003017.pdf

???

Great reference.  See page 45 for Teflon.  At 2Ghz it starts to get nonlinear, however this is at what amount of electric field and temperature?

Look around 30 GHz
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 06:18 pm
I think that's unlikely.  Paul has been looking at teflon for along time and probably because he is of the opinion that Woodward's and White's models form different sides of the same coin.  Paul believes both Woodward and White are correct.  Even though i can't agree, I would note that one logical response to this belief is to stick dielectric into a resonator to test Jim's theory.  Sonny would never do this--test Woodward's work--unless he had convinced himself he was testing his own model at the same time.  Teflon has a very poor k~2, but it is good up into microwave territory.  Most ceramics the k drops off way before.  In fact I only know of one that maintains it's high k to about 1 Ghz, and that is single crystal.  They are certainly not using that.

Probably just a teflon sheet, though if its there to check Woodward's theory, then it is installed with one side against one of the ends of the resonator chamber and would act in 1/4 wave fashion.

Thanks, Ron as your post should motivate further reflection on what dielectric material NASA used for the truncated cone. Teflon was an initial assumption (just based on the fact that Teflon was the only dielectric material mentioned in the report, albeit for the Cannae drive).  We didn't have your additional arguments.

Let me add another argument: I expect a more nonlinear response from Teflon (PTFE) than from a ceramic, particularly with Teflon exposed to an electric field ~ 45000 Volt/meter [Note this is based on back of the envelope calculations: not too different a field than from the maximum for the Cannae drive, NASA did not give the COMSOL numbers for the truncated cone electric field, particularly at the dielectric resonator]

Interested on what others  think about Ron's reasoning above for Teflon instead of a ceramic as the dielectric  for NASA's truncated cone.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700003017.pdf

???

Great reference.  See page 45 for Teflon.  At 2Ghz it starts to get nonlinear, however this is at what amount of electric field and temperature?

Look around 30 GHz

OK I'm back to this.  Here I attach the graph showing the dielectric properties of Teflon vs frequency.

@notsosureofit :  why look at 30GHz if the NASA tests operated at 2 GHz? 

I propose the following:  just like the glass transition temperature of polymers shift with the WLF equation, the dielectric properties also are a function of temperature and electric field
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/07/2014 06:25 pm
I'd be very interested to see the piezo and electrostrictive coefficients for this.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/07/2014 06:31 pm
I think that's unlikely.  Paul has been looking at teflon for along time and probably because he is of the opinion that Woodward's and White's models form different sides of the same coin.  Paul believes both Woodward and White are correct.  Even though i can't agree, I would note that one logical response to this belief is to stick dielectric into a resonator to test Jim's theory.  Sonny would never do this--test Woodward's work--unless he had convinced himself he was testing his own model at the same time.  Teflon has a very poor k~2, but it is good up into microwave territory.  Most ceramics the k drops off way before.  In fact I only know of one that maintains it's high k to about 1 Ghz, and that is single crystal.  They are certainly not using that.

Probably just a teflon sheet, though if its there to check Woodward's theory, then it is installed with one side against one of the ends of the resonator chamber and would act in 1/4 wave fashion.

Thanks, Ron as your post should motivate further reflection on what dielectric material NASA used for the truncated cone. Teflon was an initial assumption (just based on the fact that Teflon was the only dielectric material mentioned in the report, albeit for the Cannae drive).  We didn't have your additional arguments.

Let me add another argument: I expect a more nonlinear response from Teflon (PTFE) than from a ceramic, particularly with Teflon exposed to an electric field ~ 45000 Volt/meter [Note this is based on back of the envelope calculations: not too different a field than from the maximum for the Cannae drive, NASA did not give the COMSOL numbers for the truncated cone electric field, particularly at the dielectric resonator]

Interested on what others  think about Ron's reasoning above for Teflon instead of a ceramic as the dielectric  for NASA's truncated cone.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700003017.pdf

???

Great reference.  See page 45 for Teflon.  At 2Ghz it starts to get nonlinear, however this is at what amount of electric field and temperature?

Look around 30 GHz

OK I'm back to this.  Here I attach the graph showing the dielectric properties of Teflon vs frequency.

@notsosureofit :  why look at 30GHz if the NASA tests operated at 2 GHz? 

I propose the following:  just like the glass transition temperature of polymers shift with the WLF equation, the dielectric properties also are a function of temperature and electric field

Because if the 2GHz is just providing energy for some other interaction, be it M-E or axion, etc.  It will be happening at the 30GHz atomic resonance where the impedances might find a match. (or at least act as a capacitive frequency multiplier or mixer)

PS:  anyone been able to open p.17 of the report ? (OK 5th time never fails)
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 07:02 pm
I'd be very interested to see the piezo and electrostrictive coefficients for this.

I had looked at piezo a couple of weeks ago, and I can't find the report now.  I remember that there has been a fair amount of activity during the last few years measuring properties of Teflon and that Teflon had positive piezoelectric coefficient and that it was not negligible (of course much lower than materials that are normally used for piezoelectric effect). Can't comment on electrostrictive coefficient.
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 07:05 pm
...
PS:  anyone been able to open p.17 of the report ? (OK 5th time never fails)

No problem opening page 17.  I attach it here
Title: Re: EM Drive Developments
Post by: Mulletron on 10/07/2014 07:10 pm
Oh here it is! That's all folks! :o
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/07/2014 07:26 pm
Well, on the teflon issue--a quick scan shows PTFE has a piezo coefficient about 2-3 orders below things like PZT, which is about 0.1%.  According to this, it also has a good electrostrictive coefficient:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=832050&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F6733%2F18004%2F00832050.pdf%3Farnumber%3D832050

And PTFE is easy to dope, so for example one could use the percolation threshold technique and Schottky Barrier to generate a very large k despite it has a crummy k.  Given these, Teflon is not a bad choice for an M-E dielectric.

We don't know if extrinsic contributions to k can be used for M-E generation.  The materials science is just not there yet.  In fact, what we want to do is use these mechanisms with materials we already know work, to determine more about how M-E is stored.  However, given these extrinsic mechanism can store M-E, is is easy to see how it could be used especially at millimeter wave frequencies to get thrust.  A simple sinewave is sufficient since the material itself has 1w piezo response and 2w electrostrictive response.  If the piezo response is negative, the two will add rather than subtract where they overlap and pronounced effects should be observed.  So if this is what Eagle is doing, I suggest dope the PTFE with carbon nanotubes and see if that doesn't jump the thrust several orders magnitude through percolation threshold contribution.
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 07:48 pm
Well, on the teflon issue--a quick scan shows PTFE has a piezo coefficient about 2-3 orders below things like PZT, which is about 0.1%.  According to this, it also has a good electrostrictive coefficient:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=832050&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F6733%2F18004%2F00832050.pdf%3Farnumber%3D832050

And PTFE is easy to dope, so for example one could use the percolation threshold technique and Schottky Barrier to generate a very large k despite it has a crummy k.  Given these, Teflon is not a bad choice for an M-E dielectric.

We don't know if extrinsic contributions to k can be used for M-E generation.  The materials science is just not there yet.  In fact, what we want to do is use these mechanisms with materials we already know work, to determine more about how M-E is stored.  However, given these extrinsic mechanism can store M-E, is is easy to see how it could be used especially at millimeter wave frequencies to get thrust.  A simple sinewave is sufficient since the material itself has 1w piezo response and 2w electrostrictive response.  If the piezo response is negative, the two will add rather than subtract where they overlap and pronounced effects should be observed.  So if this is what Eagle is doing, I suggest dope the PTFE with carbon nanotubes and see if that doesn't jump the thrust several orders magnitude through percolation threshold contribution.
But, from my R&D work in polymers, PTFE properties are very dependent on temperature, strain rate, strain, and other variables.  It is a thermoplastic, without any cross-linking.  As @notsosureofit stated it will have very complicated properties.  If it is doped the properties are going to be even more complicated (it will be inhomogenous and if loaded with carbon nannotubes it may become anisotropic if preferentially aligned).  It would not be my first choice for an R&D program unless I would have a lab with a dielectrometer, FTIR, DSC, TGA, TMA, DTMA and an MTS to investigate its nonlinear properties as a function of several variables and fully characterize it...

I have actually investigated the properties of polymers like this versus frequency (like p. 45 of this report) and I know that this tan delta curve (see below) is very dependent on other variables .   

Also, there are several qualities of PTFE in the market, who knows what kind of PTFE they actually had.

But, as an empirical, approach, like Edison did so well for investigating materials for the light bulb, I think the idea of "suggest dope the PTFE with carbon nanotubes and see if that doesn't jump the thrust several orders magnitude through percolation threshold contribution." is a very good idea. 

The problem is that like Mulletron said, why didn't NASA run more experiments?  It looks like it takes a long time to just run a few experiments and there are countless material choices to explore...

Title: Re: EM Drive Developments
Post by: zen-in on 10/07/2014 08:14 pm
Well, on the teflon issue--a quick scan shows PTFE has a piezo coefficient about 2-3 orders below things like PZT, which is about 0.1%.  According to this, it also has a good electrostrictive coefficient:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=832050&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F6733%2F18004%2F00832050.pdf%3Farnumber%3D832050

And PTFE is easy to dope, so for example one could use the percolation threshold technique and Schottky Barrier to generate a very large k despite it has a crummy k.  Given these, Teflon is not a bad choice for an M-E dielectric.

We don't know if extrinsic contributions to k can be used for M-E generation.  The materials science is just not there yet.  In fact, what we want to do is use these mechanisms with materials we already know work, to determine more about how M-E is stored.  However, given these extrinsic mechanism can store M-E, is is easy to see how it could be used especially at millimeter wave frequencies to get thrust.  A simple sinewave is sufficient since the material itself has 1w piezo response and 2w electrostrictive response.  If the piezo response is negative, the two will add rather than subtract where they overlap and pronounced effects should be observed.  So if this is what Eagle is doing, I suggest dope the PTFE with carbon nanotubes and see if that doesn't jump the thrust several orders magnitude through percolation threshold contribution.
But, from my R&D work in polymers, PTFE properties are very dependent on temperature, strain rate, strain, and other variables.  It is a thermoplastic, without any cross-linking.  As @notsosureofit stated it will have very complicated properties.  If it is doped the properties are going to be even more complicated (it will be inhomogenous and if loaded with carbon nannotubes it may become anisotropic if preferentially aligned).  It would not be my first choice for an R&D program unless I would have a lab with a dielectrometer, FTIR, DSC, TGA, TMA, DTMA and an MTS to investigate its nonlinear properties as a function of several variables and fully characterize it...

I have actually investigated the properties of polymers like this versus frequency (like p. 45 of this report) and I know that this tan delta curve (see below) is very dependent on other variables .   

Also, there are several qualities of PTFE in the market, who knows what kind of PTFE they actually had.

But, as an empirical, approach, like Edison did so well for investigating materials for the light bulb, I think the idea of "suggest dope the PTFE with carbon nanotubes and see if that doesn't jump the thrust several orders magnitude through percolation threshold contribution." is a very good idea. 

The problem is that like Mulletron said, why didn't NASA run more experiments?  It looks like it takes a long time to just run a few experiments and there are countless material choices to explore...

Those graphs look like they are old and out of date.   PTFE is widely used as a substrate in microwave pcbs and other places where its low loss over wide microwave frequencies is required.   I extracted the following graph from this recent paper:
www.radioeng.cz/fulltexts/2012/12_02_0551_0556.pdf
When I have some time I will post some pictures of 900 MHz ceramic resonators.   Every cell phone has a few of them inside.   Cell phones would not be so slim and lightweight without them.   It's possible they are using a 965 MHz ceramic filter in a frequency doubled mode.
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 08:46 pm
...
Those graphs look like they are old and out of date.   PTFE is widely used as a substrate in microwave pcbs and other places where its low loss over wide microwave frequencies is required.   ..

While this additional reference is useful and I appreciate it, I would not characterize the older one (NASA Langley) out of date.  This new reference (please correct me if I am wrong) as well as the older one does not chemically characterize the type of PTFE being tested, nor the manufacturing method used to make it.. (Actually many specifics of the manufacturing process are proprietary trade secrets of the manufacturers.)  They treat PTFE as a generic material that should have the same properties regardless of manufacturer or manufacturing method (a most dangerous thing to assume particularly with polymers).  If properties differ between tested material properties for polymers between different sources, one may consider that the difference may be real due to different manufacturing used for the polymers being tested.   Actually, it is not unknown that the same manufacturer may have produced polymers, under the same brand name, with different properties from time to time...
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 09:09 pm

Those graphs look like they are old and out of date.   PTFE is widely used as a substrate in microwave pcbs and other places where its low loss over wide microwave frequencies is required.   I extracted the following graph from this recent paper:
www.radioeng.cz/fulltexts/2012/12_02_0551_0556.pdf
When I have some time I will post some pictures of 900 MHz ceramic resonators.   Every cell phone has a few of them inside.   Cell phones would not be so slim and lightweight without them.   It's possible they are using a 965 MHz ceramic filter in a frequency doubled mode.
I attach a graph from http://goo.gl/wv0Tyl  showing the mechanical properties (storage modulus E’, loss modulus E’’ and the ratio between these, the mechanical tan delta) of PTFE. A step in the storage modulus was measured at -123°C (onset temperature). This transition, which was not detected by the other methods employed is most probably due to a g-relaxation . Between 19°C (onset) and 39°C (end temperature), a further step of a factor of 3 can be seen in the storage modulus. Please observe that this transition (comprising a change of a factor of 3 in storage modulus occurs at room temperature !!!!!  )

The storage modulus E' is essentially (for practical purposes) the elastic modulus.  This shows that Teflon is very nonlinear at room temperature and its properties are very dependent on temperature even in the room temperature range


I also attach below the thermal diffusivity and thermal conductivity of Teflon showing transitions in the room temperature range !!!

At 110°C (onset), a further slope change can be seen in the storage modulus. This effect can be explained by the glass transition of the amorphous contents of the sample.

Very nonlinear material , would not be my first choice to use without a lab to fully characterize it, and to my knowledge Eagleworks does not have FTIR, DSC, TMA, TGA, DTMA, dielectrometry, MTS, thermal conductivity tester, etc. Solo dicendo  ;)
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/07/2014 09:18 pm
You might want to use a URL shortener for that PDF; it's breaking the forum formatting!
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/07/2014 09:19 pm
The problem is that like Mulletron said, why didn't NASA run more experiments?  It looks like it takes a long time to just run a few experiments and there are countless material choices to explore...
They probably did, the day after the conference.  You know these things are never timed well.  They just went out with what they had at the time in order to get some press.  When you're raising money for your lab, any press is good press.
Title: Re: EM Drive Developments
Post by: Rodal on 10/07/2014 09:24 pm
You might want to use a URL shortener for that PDF; it's breaking the forum formatting!
Thank you @RotoSequence, great suggestion !   :)
Done
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 12:42 am
I was looking for any evidence that dark matter interacts with RF waves. This leads to considering the red shift as perhaps due to dark matter interaction.

I found one guy who claims that dark matter does not exist, the missing mass is diatomic hydrogen. That was interesting so here is the link.

http://www.newtonphysics.on.ca/hydrogen/ (http://www.newtonphysics.on.ca/hydrogen/)

I found another guy who claims that light interaction with dark matter does cause the red shift. That was more interesting because he gave some math. Under the constraints of his model, which seem valid for light in interstellar space, he gives the equation:

dp/dt = -H p as the change in momentum, p, of a photon, where H is the Hubble constant equals about 2.2 x 10^-18 per second.
Note that the value of H has been changing and being refined rapidly over the last few years. This value is from about 2013.

The reason this is interesting is because this change in momentum attributed to dark matter implies an equal and opposite change in momentum in the dark matter.

At this point I'm not going to derive the effect that this proposed coupling of RF wave photons and dark matter may have on the thruster cavity. It seems small though.

Here is the link:

http://arxiv.org/ftp/arxiv/papers/0704/0704.1044.pdf (http://arxiv.org/ftp/arxiv/papers/0704/0704.1044.pdf)


As to frequencies expected to strongly couple with dark matter look at the ADXM Axion Dark Matter Experiment (slide 30):

http://indico.cern.ch/event/300768/session/0/contribution/30/material/slides/1.pdf

This shows that the cavity frequencies are from 0.5 GHz to 10 GHz

NASA Eagleworks experiments were at ~ 2 GHz which seems to be the ADXM target at the end of the 2014 target (please notice that the horizontal scales are logarithmic). So ADXM has NOT looked for Dark Matter at the frequencies tested by NASA Eagleworks yet.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/08/2014 12:42 am
John Baez, who is not to be confused with Albert Baez, the physicist, mathematician,  Joan Baez's father, and the narrator and star of the most excellent physics movie which I ever saw, back in HS, with Mr. Russo, physics teacher, who also taught me elementary Russian, has a list, which a new friend of mine told me about.

[grammatical note: I don't think I need to use semi-colons, but hey.  One of you guys will be on it if I should have.]

Ipso fatso, I present:

http://math.ucr.edu/home/baez/crackpot.html

You get five points just for passing the Turing test!  Too bad I can't post it on the thread that I started with such promise:

http://forum.nasaspaceflight.com/index.php?topic=34318.msg1175864#msg1175864

Why, I ask, do the heathen rage?

http://en.wikipedia.org/wiki/Albert_Baez

More importantly:

The movie, black and white, 16mm, introduced a number of things about physics, the most noteworthy being a room full of ping pong balls on loaded mousetraps.  Mr. Baez threw in the first ping pong  ball to start the chain reaction.  It was spectacular.  In one of the handful of brilliant moves that I've made here and there in the cosmos, I asked if we could see that part backwards.

And lo, Athena smiled upon me, Mr. Russo granted permission, and the projectionist reversed the chain reaction to the point where the first ball magically flew back into Mr. Baez's hand.  The class erupted in applause.  I gotta hug from my would be GF at the time.
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 01:04 am

More importantly:

The movie, black and white, 16mm, introduced a number of things about physics, the most noteworthy being a room full of ping pong balls on loaded mousetraps.  Mr. Baez threw in the first ping pong  ball to start the chain reaction.  It was spectacular.  In one of the handful of brilliant moves that I've made here and there in the cosmos, I asked if we could see that part backwards.

And lo, Athena smiled upon me, Mr. Russo granted permission, and the projectionist reversed the chain reaction to the point where the first ball magically flew back into Mr. Baez's hand.  The class erupted in applause.  I gotta hug from my would be GF at the time.

Just reading this <<10 points for each favorable comparison of yourself to Einstein, or claim that special or general relativity are fundamentally misguided (without good evidence).>> Wait a minute, full stop  !!!!!, I just realized that the John S. Fornaro (with the "?" ) in that picture above does not look like this one   :):

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=609875;image)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/08/2014 01:55 am
It's a temporal issue, my good doctor.  Time is assymetric.

As Rafiki sez:  "Loook harder"

http://www.youtube.com/watch?v=9tmLn6N_Srw
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 08:11 am
It's a temporal issue, my good doctor.  Time is assymetric.

As Rafiki sez:  "Loook harder"

http://www.youtube.com/watch?v=9tmLn6N_Srw

That just gave me a philosophygasm. Maybe this better illustrates why time is asymmetric. I know it sounds stupid, but seriously though, Simba's young appearance isn't symmetrical with his adult appearance.

The myriad of chemical reactions that happened inside your body over the years which took you from the person you used to be to the person you are now are not reversible.  They must obey thermodynamics and the arrow of time.

The fact that we experience time at all is set forth in T-symmetry, our expanding universe, and thermodynamics, but the rate in which we experience time is a function of our velocity and position with respect to the local gravity well (gravitational potential) and the depth of the gravity well. Here on earth, our well is defined by all the matter around us within our galaxy. This is further expanded on by our galaxy's position within galaxy clusters, superclusters, etc. Given this, it is known that the rate of which you experience time is fully dependent on your acceleration with respect to your local frame of reference and the universe as a whole, and your position in the gravity well you exist in. Place yourself in intergalactic space, outside of any dominant gravity well (except the universe itself) you would experience acceleration (very small acceleration) only with respect to the universe at large. Because you have very little acceleration and have a very small velocity, you would experience time much differently with respect to the rate of which a person residing on planet earth would. Time would not stop though because the universe is expanding. This is demonstrated by the experiments where a cesium beam clock was flown around, while another synchronized cesium beam clock was left on earth. They experienced time differently. The ones on the planes experienced time more slowly/less slowly/faster. Depending on frame of reference and how you look at it. This effect was modified by flying east or west around the world. The same principle applies to astronauts on the ISS. They experience time differently by virtue of their velocity and their position with respect to the bottom of the local gravity well. They experience time differently than we do. Their altitude makes time go by faster for them but their velocity makes time go by more slowly for them with respect to the earth, the difference is lost in heat. The difference in time experienced is a known calculable quantity. You don't need to go very fast in order to time travel. You can also go very slow. The vector magnitude of the rate which you experience time depends on the direction you are moving, either toward, away, or around your local gravitational well. I think that the difference in potential between two objects with equal and opposite velocities (experiencing time differently) can be expressed most simply as heat, or differently, the difference in potential between two objects experiencing time at different rates can be expressed as energy. This energy, when concentrated over a small area of space, gives rise to mass, which deforms spacetime, creating a gravity well.

So if I got this right; go fast and your watch runs slow. Go high and your watch runs fast. Go high and fast around your gravity well, against or with rotation, you get faster or slower clock, modified by the base rate set by your gravitational potential based on your height in your local gravity well. Go down or up your gravity well, no real useful clock difference because the temporal difference in potential is lost to heat, meaning more and more energy is needed due to those pesky conservation laws (why we can't go as fast as C). Spiral down your gravity well while accelerating? Not sure. I can make time go by faster or slower but never stop time or reverse it. This doesn't really help us much in a spherical universe.

Anyway, all of this is relevant to the emdrive (asymmetric universe inside, asymmetric difference with our universe outside) by virtue of the true origin of inertia. Inertia is the resistance of an object to changes to movement and acceleration. Acceleration happens over time. What I'm picturing inside the emdrive, if particles have more inertia on the round end than they do on the small end, there is an inertial difference of potential, a temporal difference of potential, which has to be balanced. How is it balanced? By mechanical motion of the apparatus? By uneven heating of the conical cavity? By uneven momentum of the particles within the cavity and uneven heating, causing it to move? Yeah that's it. Does this explain the anomalous thrust? Sounds consistent with GR and SR to me.

An interesting after thought is how angular momentum and differences between angular momentum play a role in the magnitude time is slowed.....and what can we do with that knowledge. If converting differences in linear momentum to differences of angular momentum within emdrive (a consequence of the inertial gradient) could be accomplished...........you would get something very exciting.
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 11:51 am
A lesson on persistence and resilience from this year's Nobel Physics winner :

“Initially, people said this research wouldn’t be completed within the 20th century, so colleagues left, one after another,” Mr. Akasaki [Nobel Prize in Physics, 2014] said,

“It never occurred to me to abandon it. I just continued doing what I wanted to do. It didn’t matter to me whether I would succeed or fail.”

The Nobel Prize in Physics 2014 was awarded jointly to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura "for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources".
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 12:48 pm
Anyway the ideas concerning time, space, energy and conservations of thereof,  in my view, point to a discrepancy between linear and angular momentum, the nature of which I don't know. I believe the universe is completely and consistent in conservation and symmetry down to .0000000000000000000000000000????????? decimal points, but the little bit leftover is what is left to play with. In the context of infinity, that little bit is enough.

I don't see why there is a perceived dichotomy between philosophy and science, as long as each applies their tenets equally, they are consistent with each other.

Edit:

It is probably pi.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/08/2014 02:08 pm
philosophygasm

Not at all sure if that's a good thing or a bad thing.  As always, assuming the good. ...

First, your retelling of part of the story regarding time's apparent assymetry was very well written.  So thank you for that.

Still, many events in the universe are seen as being reversible, particularly on the quantum level.

Quote from: Mulletron
Place yourself in intergalactic space...

I asked you to show me one particle which is not accelerating, and you can't, because all particles are accelerating somehow...

Quote from: Mulletron
Anyway, all of this is relevant to the emdrive (asymmetric universe inside, asymmetric difference with our universe outside) by virtue of the true origin of inertia.

Do objects undergoing NO acceleration have inertial mass? NO (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1267489#msg1267489)

...Therefore, I take issue with the above statement.  We still don't know what the "true" orgigin of inertia is.

Now, if one law of the universe can be broken, then all laws of the universe can be broken.

If a "new universe" is being created inside a copper can, which, tho not shielded from gravity, is subject to all other universal laws, two questions occur.  How can it be called a "new universe" if subject to the inertial laws of this one?  Is the 45 degree angled copper can the only way this assymetrical acceleration can occur?  Third, does it ever have pragmatic application, since the decimal point you mention (.0000000000000000000000000000?????????) is so tiny?

The bottom line distillation of the experimental apparatus is simply that they assert that they can convert electrical energy to forward momentum, somehow taking advantage of the Energy-momentum relation:

http://en.wikipedia.org/wiki/Energy%E2%80%93momentum_relation

At the same time, as I've hinted at here and there in this thread, I intuitively hold   the view that the old Cartesian model of reality (that there were two interacting kinds of substance - mental and physical) >was is limited (http://en.wikipedia.org/wiki/David_Bohm).

Per Bohm, "the whole notion of active information suggests a rudimentary mind-like behaviour of matter".  Which ties into the Akashic records mentioned earlier; part of a unified theory that I'm working on.

http://en.wikipedia.org/wiki/Implicate_and_explicate_order

Quote from: David Bohm
In the enfolded [or implicate] order, space and time are no longer the dominant factors determining the relationships of dependence or independence of different elements. Rather, an entirely different sort of basic connection of elements is possible, from which our ordinary notions of space and time, along with those of separately existent material particles, are abstracted as forms derived from the deeper order. These ordinary notions in fact appear in what is called the "explicate" or "unfolded" order, which is a special and distinguished form contained within the general totality of all the implicate orders (Bohm 1980, p. xv).

Point being twofold:  ('Fold'.  Get it? I crack myself up sometimes (http://www.youtube.com/watch?v=-mvldYk72hk).)

The EM-drive explanations so far are incomplete.  And maybe there's a way to consider time as reversible.  There are "hidden" variables still.  Hidden in the sense that we don't know about them yet.  And third, there may be no practical applications of this technology at all.

An analysis or description of any aspect of reality (e.g., quantum theory, the speed of light) can be unlimited in its domain of relevance (http://en.wikipedia.org/wiki/Implicate_and_explicate_order#Challenges_to_some_generally_prevailing_views)

Veering briefly from the topic at hand: Reason?  Who needs it?  When it serves survival, yeah.  I warn of the dangers of rampant reason and technology.  WRT HSF, deconstructive and reductionistic scientificism holds that elective war trumps HSF. "U.S. Consul in São Paulo ... confiscated [Bohm's] passport."  Further discussion welcome on the PM channel, particularly if you don't immediately grasp the connection I'm making.

Like I always say:

“It never occurred to me to abandon [my inquiry]. I just continued doing what I wanted to do. It didn’t matter to me whether I would succeed or fail.”

Although it would be nice to get paid...

Finally, I thought Archimedes invented the screw!
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 02:15 pm
philosophygasm

Not at all sure if that's a good thing or a bad thing.  As always, assuming the good. ...

First, your retelling of part of the story regarding time's apparent assymetry was very well written.  So thank you for that.

Still, many events in the universe are seen as being reversible, particularly on the quantum level.

Quote from: Mulletron
Place yourself in intergalactic space...

I asked you to show me one particle which is not accelerating, and you can't, because all particles are accelerating somehow...

Quote from: Mulletron
Anyway, all of this is relevant to the emdrive (asymmetric universe inside, asymmetric difference with our universe outside) by virtue of the true origin of inertia.

Do objects undergoing NO acceleration have inertial mass? NO (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1267489#msg1267489)

...Therefore, I take issue with the above statement.  We still don't know what the "true" orgigin of inertia is.

Now, if one law of the universe can be broken, then all laws of the universe can be broken.

If a "new universe" is being created inside a copper can, which, tho not shielded from gravity, is subject to all other universal laws, two questions occur.  How can it be called a "new universe" if subject to the inertial laws of this one?  Is the 45 degree angled copper can the only way this assymetrical acceleration can occur?  Third, does it ever have pragmatic application, since the decimal point you mention (.0000000000000000000000000000?????????) is so tiny?

The bottom line distillation of the experimental apparatus is simply that they assert that they can convert electrical energy to forward momentum, somehow taking advantage of the Energy-momentum relation:

http://en.wikipedia.org/wiki/Energy%E2%80%93momentum_relation

At the same time, as I've hinted at here and there in this thread, I intuitively hold   the view that the old Cartesian model of reality (that there were two interacting kinds of substance - mental and physical) >was is limited (http://en.wikipedia.org/wiki/David_Bohm).

Per Bohm, "the whole notion of active information suggests a rudimentary mind-like behaviour of matter".  Which ties into the Akashic records mentioned earlier; part of a unified theory that I'm working on.

http://en.wikipedia.org/wiki/Implicate_and_explicate_order

Quote from: David Bohm
In the enfolded [or implicate] order, space and time are no longer the dominant factors determining the relationships of dependence or independence of different elements. Rather, an entirely different sort of basic connection of elements is possible, from which our ordinary notions of space and time, along with those of separately existent material particles, are abstracted as forms derived from the deeper order. These ordinary notions in fact appear in what is called the "explicate" or "unfolded" order, which is a special and distinguished form contained within the general totality of all the implicate orders (Bohm 1980, p. xv).

Point being twofold:  ('Fold'.  Get it? I crack myself up sometimes (http://www.youtube.com/watch?v=-mvldYk72hk).)

The EM-drive explanations so far are incomplete.  And maybe there's a way to consider time as reversible.  There are "hidden" variables still.  Hidden in the sense that we don't know about them yet.  And third, there may be no practical applications of this technology at all.

An analysis or description of any aspect of reality (e.g., quantum theory, the speed of light) can be unlimited in its domain of relevance (http://en.wikipedia.org/wiki/Implicate_and_explicate_order#Challenges_to_some_generally_prevailing_views)

Veering briefly from the topic at hand: Reason?  Who needs it?  When it serves survival, yeah.  I warn of the dangers of rampant reason and technology.  WRT HSF, deconstructive and reductionistic scientificism holds that elective war trumps HSF. "U.S. Consul in São Paulo ... confiscated [Bohm's] passport."  Further discussion welcome on the PM channel, particularly if you don't immediately grasp the connection I'm making.

Like I always say:

“It never occurred to me to abandon [my inquiry]. I just continued doing what I wanted to do. It didn’t matter to me whether I would succeed or fail.”

Although it would be nice to get paid...

Finally, I thought Archimedes invented the screw!

Quoting myself above: "Place yourself in intergalactic space, outside of any dominant gravity well (except the universe itself) you would experience acceleration (very small acceleration) only with respect to the universe at large. "

The algorithm I put together a few pages back is a thought experiment about what NO acceleration would be like. The notion of NO acceleration is immaterial in reality. Just very low accelerations are real. Given the perceived dipole moment of the CMB, there cannot ever be exactly 0 acceleration.

I maintain that the true origin of inertia is time.

You can't separate space from time. You can't separate energy from either space or time. You can't separate information (causality) from any of those.

I also hedge (and I can't back this one up, as much as I would like to; it is over my head) that the most fundamental thing in the universe, what ties mass/energy/conservation together is, information. The whole notion of information as is being key to everything is what got me started on this journey. Thanks to Wolfram and Von Neumann.

Edit: Left out Turing.
Also, .0000000000000000000000000000????????? applied to constant acceleration ends up being a lot.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/08/2014 02:38 pm
Quote
Do objects undergoing NO acceleration have inertial mass? NO
Sorry but this is just wrong.  Look up any defintion of inertial mass or EEP and you'll find that this is not true.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 02:40 pm
Quote
Do objects undergoing NO acceleration have inertial mass? NO
Sorry but this is just wrong.  Look up any defintion of inertial mass or EEP and you'll find that this is not true.

Okay but that is a question, not a statement. Thanks for the spirited debate.
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 03:12 pm
I have been corresponding with Prof. McCulloch in his blog.  He has kindly posted his predictions vs. experimental measurements for Shawyer and for NASA's Brady et.al. in his spreadsheet here:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

I also just submitted to Prof. McCulloch tentative MiHsC predictions vs. measurements for the Chinese experiments (see the above blog's comments for more details if interested).
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/08/2014 03:46 pm
The algorithm I put together a few pages back is a thought experiment about what NO acceleration would be like.

That's totally fine, in principle.

Quote from: Mulletron
Do objects undergoing NO acceleration have inertial mass? NO

And the question here, is fine too, in principle.  But you answered the question, and my only objection is that I don't think your answer is correct.

Quote from: Mulletron
Edit: Left out Turing.

One further edit:  You also left out the Rig Veda. 

One wonders how much science has been discovered and lost over the eons.  At least I do, what with all the inquisitions, great leaps forward, blah, blah, blah, that have taken place over the millenia.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/08/2014 03:47 pm
...(see the above blog's comments for more details if interested).

Whew.  [Dbug salute]
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/08/2014 04:04 pm
I have been corresponding with Prof. McCulloch in his blog.  He has kindly posted his predictions vs. experimental measurements for Shawyer and for NASA's Brady et.al. in his spreadsheet here:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

I also just submitted to Prof. McCulloch tentative MiHsC predictions vs. measurements for the Chinese experiments (see the above blog's comments for more details if interested).

His reasoning may be different, but it's the same argument as Shawyer's once the horizon is set at the boundary
Title: Re: EM Drive Developments
Post by: aero on 10/08/2014 04:05 pm
I have been corresponding with Prof. McCulloch in his blog.  He has kindly posted his predictions vs. experimental measurements for Shawyer and for NASA's Brady et.al. in his spreadsheet here:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

I also just submitted to Prof. McCulloch tentative MiHsC predictions vs. measurements for the Chinese experiments (see the above blog's comments for more details if interested).

Those are some very interesting results. You might ask Prof. McCulloch to analyze the Cannae device which doesn't have a big end and small end, yet produced thrust. It does have the dielectric. I'm not sure if the Shawyer and the Chinese devices had dielectrics, though.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 04:11 pm
IRT the question on why the dielectric is essential or not. Think of it this way. You have to convert that inertial gradient to linear movement somehow. Emdrive would work without it. It would work MUCH better with it. Now we're back to Abraham-Minkowski again, and the whole field of optics.
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 04:12 pm
I have been corresponding with Prof. McCulloch in his blog.  He has kindly posted his predictions vs. experimental measurements for Shawyer and for NASA's Brady et.al. in his spreadsheet here:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

I also just submitted to Prof. McCulloch tentative MiHsC predictions vs. measurements for the Chinese experiments (see the above blog's comments for more details if interested).

Those are some very interesting results. You might ask Prof. McCulloch to analyze the Cannae device which doesn't have a big end and small end, yet produced thrust. It does have the dielectric. I'm not sure if the Shawyer and the Chinese devices had dielectrics, though.

Thanks @notsosureofit, for Prof. McCulloch to analyze any drive he needs the Q factor, and unfortunately I cannot find the Q factor for the Cannae device.  That's one problem.  The other problem is the geometry.  The Cannae device has a symmetric pillbox geometry [as opposed to the truncated cones of Shawyer, NASA and the Chinese, which have one flat end larger than the other flat end], so according to Prof. McCulloch's simplified formula it should not generate any thrust force (based on photons).  I had a brief exchange with him on the issue of the dielectric.  My understanding of his response is that he would have to consider the electrons in the dielectric rather than the photons in the cavity to explain the Cannae device.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 04:14 pm
I have been corresponding with Prof. McCulloch in his blog.  He has kindly posted his predictions vs. experimental measurements for Shawyer and for NASA's Brady et.al. in his spreadsheet here:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

I also just submitted to Prof. McCulloch tentative MiHsC predictions vs. measurements for the Chinese experiments (see the above blog's comments for more details if interested).

Those are some very interesting results. You might ask Prof. McCulloch to analyze the Cannae device which doesn't have a big end and small end, yet produced thrust. It does have the dielectric. I'm not sure if the Shawyer and the Chinese devices had dielectrics, though.

Thanks @notsosureofit, for Prof. McCulloch to analyze any drive he needs the Q factor, and unfortunately I cannot find the Q factor for the Cannae device.  That's one problem.  The other problem is the geometry.  The Cannae device has a symmetric pillbox geometry, so according to Prof. McCulloch's simplified formula it should not generate any thrust force (based on photons).  I had a brief exchange with him on the issue of the dielectric.  My understanding of his response is that he would have to consider the electrons in the dielectric rather than the photons in the cavity to explain the Cannae device.

The pillbox is NOT perfectly symmetric. Loook harder.....
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 04:17 pm
I have been corresponding with Prof. McCulloch in his blog.  He has kindly posted his predictions vs. experimental measurements for Shawyer and for NASA's Brady et.al. in his spreadsheet here:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

I also just submitted to Prof. McCulloch tentative MiHsC predictions vs. measurements for the Chinese experiments (see the above blog's comments for more details if interested).

Those are some very interesting results. You might ask Prof. McCulloch to analyze the Cannae device which doesn't have a big end and small end, yet produced thrust. It does have the dielectric. I'm not sure if the Shawyer and the Chinese devices had dielectrics, though.

Thanks @notsosureofit, for Prof. McCulloch to analyze any drive he needs the Q factor, and unfortunately I cannot find the Q factor for the Cannae device.  That's one problem.  The other problem is the geometry.  The Cannae device has a symmetric pillbox geometry, so according to Prof. McCulloch's simplified formula it should not generate any thrust force (based on photons).  I had a brief exchange with him on the issue of the dielectric.  My understanding of his response is that he would have to consider the electrons in the dielectric rather than the photons in the cavity to explain the Cannae device.

The pillbox is NOT perfectly symmetric. Loook harder.....
As I see it, it is symmetric concerning the photons in the cavity, as relevant to Prof, McCulloch's simplified analysis: the pillbox geometry [as opposed to the truncated cones of Shawyer, NASA and the Chinese, which have one flat end larger than the other flat end].

Please instead of just stating "look harder", please point out specifically what is the asymmetry of the pillbox that is relevant to Prof. McCulloch's present simplified analysis.  :)

The present simplified formulation of Prof. McCulloch does not apply to a (pointed) cone, for example.  I have pointed out in his blog that the simplified formula would go to infinity for that case, and he completely agreed.  Prof. McCulloch stated he was going to think about a simplified formula for a pointed cone.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 04:22 pm
I have been corresponding with Prof. McCulloch in his blog.  He has kindly posted his predictions vs. experimental measurements for Shawyer and for NASA's Brady et.al. in his spreadsheet here:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

I also just submitted to Prof. McCulloch tentative MiHsC predictions vs. measurements for the Chinese experiments (see the above blog's comments for more details if interested).

Those are some very interesting results. You might ask Prof. McCulloch to analyze the Cannae device which doesn't have a big end and small end, yet produced thrust. It does have the dielectric. I'm not sure if the Shawyer and the Chinese devices had dielectrics, though.

Thanks @notsosureofit, for Prof. McCulloch to analyze any drive he needs the Q factor, and unfortunately I cannot find the Q factor for the Cannae device.  That's one problem.  The other problem is the geometry.  The Cannae device has a symmetric pillbox geometry, so according to Prof. McCulloch's simplified formula it should not generate any thrust force (based on photons).  I had a brief exchange with him on the issue of the dielectric.  My understanding of his response is that he would have to consider the electrons in the dielectric rather than the photons in the cavity to explain the Cannae device.

The pillbox is NOT perfectly symmetric. Loook harder.....
As I see it, it is symmetric concerning the photons in the cavity, as relevant to Prof, McCulloch's simplified analysis: the pillbox geometry [as opposed to the truncated cones of Shawyer, NASA and the Chinese, which have one flat end larger than the other flat end].

Please instead of just stating "look harder", please point out specifically what is the asymmetry of the pillbox that is relevant to Prof, McCulloch's present simplified analysis.  :)

The whole device, as a system is biased to one side in symmetry. The Looook harder thing started as a running joke a little bit back.
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 04:25 pm
...The whole device, as a system is biased to one side in symmetry. The Looook harder thing started as a running joke a little bit back.

Well, I cannot work mathematically with a description of "The whole device, as a system is biased to one side in symmetry", and I doubt that Prof. McCulloch will be able to work out a formula based on that description, but everybody is free to post in his blog, if you think that's enough to work out a quantitative answer  :)

Please give me a geometrical shape with dimensions that you think that the Cannae device has, because to come up with a quantitative answer we need numbers associated with a prescribed geometry  :)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 04:29 pm
...The whole device, as a system is biased to one side in symmetry. The Looook harder thing started as a running joke a little bit back.

Well, I cannot work mathematically with a description of "The whole device, as a system is biased to one side in symmetry", and I doubt that Prof. McCulloch will be able to work out a formula based on that description, but everybody is free to post in his blog, if you think that's enough to work out a quantitative answer  :)
Well you have to be able to formalize casimir interactions with 3d cavities. Lots of info out there on that.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 04:30 pm
MIT has a calculator now.

Edit:

I can tell you from all the papers I read on this, casimir interactions are notoriously complex. Not intuitive. When you factor in things like temperature, scattering, and all other variables, you can't arrive at precise intuitive answers. The simple 3d model I came up with was a generalization, based off of loose assumptions I made after reading about casimir interactions inside/outside spheres. Furthered by info I read about casimir and cones. In the context of a real device, my idea would probably need substantial modification.

I posted links to my sources here in this forum.

The math will give you a nose bleed.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/08/2014 05:22 pm
...The whole device, as a system is biased to one side in symmetry. The Looook harder thing started as a running joke a little bit back.

Well, I cannot work mathematically with a description of "The whole device, as a system is biased to one side in symmetry"...

I think what he means is that the pillbox is symmetrical radially along its axis, but there is no line of symmetry in a plane 90 degrees from the axis.

And it's "looook", not "look".
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 05:41 pm
...The whole device, as a system is biased to one side in symmetry. The Looook harder thing started as a running joke a little bit back.

Well, I cannot work mathematically with a description of "The whole device, as a system is biased to one side in symmetry"...

I think what he means is that the pillbox is symmetrical radially along its axis, but there is no line of symmetry in a plane 90 degrees from the axis.

And it's "looook", not "look".
Darth Vader, there is a great disconnect with the force: what Prof. McCulloch can actually calculate and apparently what Vader thinks can be calculated.  ;)
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 05:43 pm
[Hey, kernosabe, ya giv me da material, I work with it]

The Curious Case of Benjamin Button John Fornaro   :)   getting younger and younger


https://www.youtube.com/watch?v=aMt-SwccPD0


(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=609875;image)

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=610750;image)

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=610943;image)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/08/2014 05:46 pm
...The whole device, as a system is biased to one side in symmetry. The Looook harder thing started as a running joke a little bit back.

Well, I cannot work mathematically with a description of "The whole device, as a system is biased to one side in symmetry"...


I think what he means is that the pillbox is symmetrical radially along its axis, but there is no line of symmetry in a plane 90 degrees from the axis.

And it's "looook", not "look".
Darth Vader, there is a great disconnect with the force: what Prof. McCulloch can actually calculate and apparently what Vader thinks can be calculated.  ;)

Sawyer worked out an optimization scheme for the truncated cone which would work for McCullough's.

The Cannae drive did have asymmetry in one of the pillboxes, just made no difference.  So that is a math nightmare etc etc

(You are both young pups as far as I'm concerned. Gosh durn it !)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/08/2014 06:07 pm
Just a curiosity:

The Q of a perfect superconducting cylindrical cavity of lambda vertical dimension at the earths surface

Q = c^2/ ( g * lambda )

I think.

So maybe Shawyer is on to something w/ his deceleration curve ??
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 06:36 pm
A factor I didn't apply to the (poorly informed) 3d model I made was the effect of length contraction at relativistic speeds. I don't think there is a way to do this. Also I didn't give any treatment to the Rindler sphere approaching you, to optimize anything. In the end I dropped this problem and didn't try to solve it because it seems trying to solve it would be tantamount to trying to invalidate GR and SR, which you can't. Length contraction is the cosmic speed brake that keeps you from breaking C.

Also on the subject of asymmetries, I never fully solved the questions I brought up previously about chirality in PTFE. I haven't had time to focus on all the aspects of this subject.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 06:37 pm
Dr. Rodal. I know your expertise on experimental setups.
Please could you cast your searching eyes over this please?
http://www.sifferkoll.se/sifferkoll/wp-content/uploads/2014/10/LuganoReportSubmit.pdf
... and comment in the thread here:
http://forum.nasaspaceflight.com/index.php?topic=35805.0
Much obliged and thanks.
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 06:49 pm
Just a curiosity:

The Q of a perfect superconducting cylindrical cavity of lambda vertical dimension at the earths surface

Q = c^2/ ( g * lambda )

I think.

So maybe Shawyer is on to something w/ his deceleration curve ??

Yes, when one says goodbye to "wordy" explanations and just looks at the math, a number of explanations look very similar:

Force = ( Q* PowerInput  / frequency ) *  (1/w_up)  - ( Q* PowerInput  / frequency ) * (1/w_down)
     =   Q * PowerInput /( frequency * CharacteristicLengthA ) - Q * PowerInput /( frequency *CharacteristicLengthB )
         =   Q * ( PowerInput / CharacteristicSpeedA ) - Q * ( PowerInput / CharacteristicSpeedB )
         =  Q *  PowerInput * (1/ CharacteristicSpeedA - 1 /CharacteristicSpeedB)

Recall that, dimensionally  Power = Force * speed
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 06:54 pm
Dr. Rodal. I know your expertise on experimental setups.
Please could you cast your searching eyes over this please?
http://www.sifferkoll.se/sifferkoll/wp-content/uploads/2014/10/LuganoReportSubmit.pdf
... and comment in the thread here:
http://forum.nasaspaceflight.com/index.php?topic=35805.0
Much obliged and thanks.
Hi IslandPlaya, still appreciating you being the first one to welcome me to this forum  :)

I wish I could, but unfortunately I can't at the moment embark into another topic.  I thank you for the gracious invitation :)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/08/2014 07:06 pm
Just a curiosity:

The Q of a perfect superconducting cylindrical cavity of lambda vertical dimension at the earths surface

Q = c^2/ ( g * lambda )

I think.

So maybe Shawyer is on to something w/ his deceleration curve ??

Yes, when one says goodbye to "wordy" explanations and just looks at the math, a number of explanations look very similar:

Force = ( Q* PowerInput  / frequency ) *  (1/w_up)  - ( Q* PowerInput  / frequency ) * (1/w_down)
     =   Q * PowerInput /( frequency * CharacteristicLengthA ) - Q * PowerInput /( frequency *CharacteristicLengthB )
         =   Q * ( PowerInput / CharacteristicSpeedA ) - Q * ( PowerInput / CharacteristicSpeedB )
         =  Q *  PowerInput * (1/ CharacteristicSpeedA - 1 /CharacteristicSpeedB)

Recall that, dimensionally  Power = Force * speed

Yes, the problem I'm having that the Q from bandwidth implies an exponential decay time constant:

T = c / ( g * pi )     So where is the power going if the cavity is superconductive ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 07:10 pm
Just a curiosity:

The Q of a perfect superconducting cylindrical cavity of lambda vertical dimension at the earths surface

Q = c^2/ ( g * lambda )

I think.

So maybe Shawyer is on to something w/ his deceleration curve ??

Yes, when one says goodbye to "wordy" explanations and just looks at the math, a number of explanations look very similar:

Force = ( Q* PowerInput  / frequency ) *  (1/w_up)  - ( Q* PowerInput  / frequency ) * (1/w_down)
     =   Q * PowerInput /( frequency * CharacteristicLengthA ) - Q * PowerInput /( frequency *CharacteristicLengthB )
         =   Q * ( PowerInput / CharacteristicSpeedA ) - Q * ( PowerInput / CharacteristicSpeedB )
         =  Q *  PowerInput * (1/ CharacteristicSpeedA - 1 /CharacteristicSpeedB)

Recall that, dimensionally  Power = Force * speed

Yes, the problem I'm having that the Q from bandwidth implies an exponential decay time constant:

T = c / ( g * pi )     So where is the power going if the cavity is superconductive ?

Superconductivity: a quantum mechanics effect for which people's intuition fails, because our intuition is built around our macro world and not the quantum world.   One would have to work out the quantum mechanics math to answer
Title: Re: EM Drive Developments
Post by: zen-in on 10/08/2014 07:27 pm
Just a curiosity:

The Q of a perfect superconducting cylindrical cavity of lambda vertical dimension at the earths surface

Q = c^2/ ( g * lambda )

I think.

So maybe Shawyer is on to something w/ his deceleration curve ??

Yes, when one says goodbye to "wordy" explanations and just looks at the math, a number of explanations look very similar:

Force = ( Q* PowerInput  / frequency ) *  (1/w_up)  - ( Q* PowerInput  / frequency ) * (1/w_down)
     =   Q * PowerInput /( frequency * CharacteristicLengthA ) - Q * PowerInput /( frequency *CharacteristicLengthB )
         =   Q * ( PowerInput / CharacteristicSpeedA ) - Q * ( PowerInput / CharacteristicSpeedB )
         =  Q *  PowerInput * (1/ CharacteristicSpeedA - 1 /CharacteristicSpeedB)

Recall that, dimensionally  Power = Force * speed

Yes, the problem I'm having that the Q from bandwidth implies an exponential decay time constant:

T = c / ( g * pi )     So where is the power going if the cavity is superconductive ?

Superconductivity: a quantum mechanics effect for which people's intuition fails, because our intuition is built around our macro world and not the quantum world.   One would have to work out the quantum mechanics math to answer

One thing about superconductors most people are not aware of is that they do not work very well with AC.   There are specially designed configurations used for 60 Hz  AC transmission cables, but at higher frequencies it is my understanding that superconductors are unusable.    I don't see any way that superconductors could be used to improve this em thruster.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 07:30 pm
Dr. Rodal. I know your expertise on experimental setups.
Please could you cast your searching eyes over this please?
http://www.sifferkoll.se/sifferkoll/wp-content/uploads/2014/10/LuganoReportSubmit.pdf
... and comment in the thread here:
http://forum.nasaspaceflight.com/index.php?topic=35805.0
Much obliged and thanks.
Hi IslandPlaya, still appreciating you being the first one to welcome me to this forum  :)

I wish I could, but unfortunately I can't at the moment embark into another topic.  I thank you for the gracious invitation :)
Thank you. However the topic has been nuked (maybe on my advice.)
I am currently trying to understand Hubble and Unrhu horizons as I intuit that is the theoretical key to the anomalous thrust.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/08/2014 07:34 pm
Just a curiosity:

The Q of a perfect superconducting cylindrical cavity of lambda vertical dimension at the earths surface

Q = c^2/ ( g * lambda )

I think.

So maybe Shawyer is on to something w/ his deceleration curve ??

Yes, when one says goodbye to "wordy" explanations and just looks at the math, a number of explanations look very similar:

Force = ( Q* PowerInput  / frequency ) *  (1/w_up)  - ( Q* PowerInput  / frequency ) * (1/w_down)
     =   Q * PowerInput /( frequency * CharacteristicLengthA ) - Q * PowerInput /( frequency *CharacteristicLengthB )
         =   Q * ( PowerInput / CharacteristicSpeedA ) - Q * ( PowerInput / CharacteristicSpeedB )
         =  Q *  PowerInput * (1/ CharacteristicSpeedA - 1 /CharacteristicSpeedB)

Recall that, dimensionally  Power = Force * speed

Yes, the problem I'm having that the Q from bandwidth implies an exponential decay time constant:

T = c / ( g * pi )     So where is the power going if the cavity is superconductive ?

Superconductivity: a quantum mechanics effect for which people's intuition fails, because our intuition is built around our macro world and not the quantum world.   One would have to work out the quantum mechanics math to answer

Right on!  That gives + and - 90 degree phase shifts that cancel out, so the power goes round-n-round, so to speak.

(must have the uncertainty principle in there some where ?)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 07:37 pm
Just a curiosity:

The Q of a perfect superconducting cylindrical cavity of lambda vertical dimension at the earths surface

Q = c^2/ ( g * lambda )

I think.

So maybe Shawyer is on to something w/ his deceleration curve ??

Yes, when one says goodbye to "wordy" explanations and just looks at the math, a number of explanations look very similar:

Force = ( Q* PowerInput  / frequency ) *  (1/w_up)  - ( Q* PowerInput  / frequency ) * (1/w_down)
     =   Q * PowerInput /( frequency * CharacteristicLengthA ) - Q * PowerInput /( frequency *CharacteristicLengthB )
         =   Q * ( PowerInput / CharacteristicSpeedA ) - Q * ( PowerInput / CharacteristicSpeedB )
         =  Q *  PowerInput * (1/ CharacteristicSpeedA - 1 /CharacteristicSpeedB)

Recall that, dimensionally  Power = Force * speed

Yes, the problem I'm having that the Q from bandwidth implies an exponential decay time constant:

T = c / ( g * pi )     So where is the power going if the cavity is superconductive ?

Superconductivity: a quantum mechanics effect for which people's intuition fails, because our intuition is built around our macro world and not the quantum world.   One would have to work out the quantum mechanics math to answer

One thing about superconductors most people are not aware of is that they do not work very well with AC.   There are specially designed configurations used for 60 Hz  AC transmission cables, but at higher frequencies it is my understanding that superconductors are unusable.    I don't see any way that superconductors could be used to improve this em thruster.
Do you know the mechanism behind this? SC are used for NMR and all sorts of hi-freq things. I may be wrong though...
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 07:40 pm
Dr. Rodal. I know your expertise on experimental setups.
Please could you cast your searching eyes over this please?
http://www.sifferkoll.se/sifferkoll/wp-content/uploads/2014/10/LuganoReportSubmit.pdf
... and comment in the thread here:
http://forum.nasaspaceflight.com/index.php?topic=35805.0
Much obliged and thanks.
Hi IslandPlaya, still appreciating you being the first one to welcome me to this forum  :)

I wish I could, but unfortunately I can't at the moment embark into another topic.  I thank you for the gracious invitation :)
Thank you. However the topic has been nuked (maybe on my advice.)
I am currently trying to understand Hubble and Unrhu horizons as I intuit that is the theoretical key to the anomalous thrust.

Take another look at http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html, Prof. McCulloch has now incorporated the Chinese data, and all the data  [Shawyer, China and NASA] is pretty well calculated by McCulloch's formula except for one experiment (out of 3 in the list) by Brady et.al. that I had pointed out is extremely anomalous (they raised the Q by a factor of 2.5 and the force came down to 1/2).  The Unruth/McCulloch formula does a great job [compared to everything else that has been offered, and look at this thread we have considered all kinds of stuff].  What is most interesting again is that McCulloch does not use fudge factors or an excessive number of parameters.  Actually McCulloch's formula is bare bones:  PowerInput, Q, frequency and the geometry: that's all folks.  :)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 07:51 pm
Dr. Rodal. I know your expertise on experimental setups.
Please could you cast your searching eyes over this please?
http://www.sifferkoll.se/sifferkoll/wp-content/uploads/2014/10/LuganoReportSubmit.pdf
... and comment in the thread here:
http://forum.nasaspaceflight.com/index.php?topic=35805.0
Much obliged and thanks.
Hi IslandPlaya, still appreciating you being the first one to welcome me to this forum  :)

I wish I could, but unfortunately I can't at the moment embark into another topic.  I thank you for the gracious invitation :)
Thank you. However the topic has been nuked (maybe on my advice.)
I am currently trying to understand Hubble and Unrhu horizons as I intuit that is the theoretical key to the anomalous thrust.

Take another look at http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html, Prof. McCulloch has now incorporated the Chinese data, and all the data  [Shawyer, China and NASA] is pretty well calculated by McCulloch's formula except for one experiment (out of 3 in the list) by Brady et.al. that I had pointed out is extremely anomalous (they raised the Q by a factor of 2.5 and the force came down to 1/2).  The Unruth/McCulloch formula does a great job [compared to everything else that has been offered, and look at this thread we have considered all kinds of stuff].  What is most interesting again is that McCulloch does not use fudge factors or an excessive number of parameters.  Actually McCulloch's formula is bare bones:  PowerInput, Q, frequency and the geometry: that's all folks.  :)
Thanks!
I felt in my bones that Prof. McCulloch had a handle on this.
I will try to embiggen my knowledge further.
Title: Re: EM Drive Developments
Post by: zen-in on 10/08/2014 07:58 pm
Just a curiosity:

The Q of a perfect superconducting cylindrical cavity of lambda vertical dimension at the earths surface

Q = c^2/ ( g * lambda )

I think.

So maybe Shawyer is on to something w/ his deceleration curve ??

Yes, when one says goodbye to "wordy" explanations and just looks at the math, a number of explanations look very similar:

Force = ( Q* PowerInput  / frequency ) *  (1/w_up)  - ( Q* PowerInput  / frequency ) * (1/w_down)
     =   Q * PowerInput /( frequency * CharacteristicLengthA ) - Q * PowerInput /( frequency *CharacteristicLengthB )
         =   Q * ( PowerInput / CharacteristicSpeedA ) - Q * ( PowerInput / CharacteristicSpeedB )
         =  Q *  PowerInput * (1/ CharacteristicSpeedA - 1 /CharacteristicSpeedB)

Recall that, dimensionally  Power = Force * speed

Yes, the problem I'm having that the Q from bandwidth implies an exponential decay time constant:

T = c / ( g * pi )     So where is the power going if the cavity is superconductive ?

Superconductivity: a quantum mechanics effect for which people's intuition fails, because our intuition is built around our macro world and not the quantum world.   One would have to work out the quantum mechanics math to answer

One thing about superconductors most people are not aware of is that they do not work very well with AC.   There are specially designed configurations used for 60 Hz  AC transmission cables, but at higher frequencies it is my understanding that superconductors are unusable.    I don't see any way that superconductors could be used to improve this em thruster.
Do you know the mechanism behind this? SC are used for NMR and all sorts of hi-freq things. I may be wrong though...

Low temperature superconductors are used in NMR machines.  However the magnet is a very powerful DC magnet. 
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 08:04 pm
What is the mechanism that destroys SC for AC currents?
Please enlighten me.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 08:08 pm
http://galileo.phys.virginia.edu/classes/252/energy_p_reln.html

Helped me, sharing.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 08:09 pm
Quote
"Superconductivity: a quantum mechanics effect for which people's intuition fails, because our intuition is built around our macro world and not the quantum world.   One would have to work out the quantum mechanics math to answer."

This is a hasty generalization.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 08:14 pm
http://galileo.phys.virginia.edu/classes/252/energy_p_reln.html

Helped me, sharing.
Didn't help me I'm afraid...
Useful reference to obvious things.
But...
Does a superconductor Ts degrade due to AC current?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 08:15 pm
What is the mechanism that destroys SC for AC currents?
Please enlighten me.

Destructive interference.


Yes.

Please correct me if I'm wrong.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 08:19 pm
What is the mechanism that destroys SC for AC currents?
Please enlighten me.

Destructive interference.


Yes.

Please correct me if I'm wrong.

Lol,
At what frequency?

and topology?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 08:20 pm
What is the mechanism that destroys SC for AC currents?
Please enlighten me.

Destructive interference.


Yes.

Please correct me if I'm wrong.

Lol,
At what frequency?

and topology?

I don't think that computes. A general question begging a specific answer.
Title: Re: EM Drive Developments
Post by: zen-in on 10/08/2014 08:21 pm
What is the mechanism that destroys SC for AC currents?
Please enlighten me.

I am not an expert in the theory of superconductors.   I experiment with high temperature superconductors and I have observed some of their interesting properties.  I can't disclose any of my research.   However there is a lot of literature available on this subject.   All are concerned with VLF AC.  If you know of a case where superconductors are used at microwave frequencies I would like to be informed-

https://cas.web.cern.ch/cas/Erice-2013/Lectures/May3_1_Gomory.ppt
http://www.utwente.nl/tnw/ems/Research/AC%20loss%20Twente%20Press/AC_loss_and_stability_of_superconducting_cables_for_fusion/
http://iopscience.iop.org/0953-2048/26/9/095001/
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 08:23 pm
What is the mechanism that destroys SC for AC currents?
Please enlighten me.

I am not an expert in the theory of superconductors.   I experiment with high temperature superconductors and I have observed some of their interesting properties.  I can't disclose any of my research.   However there is a lot of literature available on this subject.   All are concerned with VLF AC.  If you know of a case were superconductors are used at microwave frequencies I would like to be informed-

https://cas.web.cern.ch/cas/Erice-2013/Lectures/May3_1_Gomory.ppt
http://www.utwente.nl/tnw/ems/Research/AC%20loss%20Twente%20Press/AC_loss_and_stability_of_superconducting_cables_for_fusion/
http://iopscience.iop.org/0953-2048/26/9/095001/
Maybe Dr Rodal would know about these things...
Title: Re: EM Drive Developments
Post by: Star One on 10/08/2014 08:29 pm

Dr. Rodal. I know your expertise on experimental setups.
Please could you cast your searching eyes over this please?
http://www.sifferkoll.se/sifferkoll/wp-content/uploads/2014/10/LuganoReportSubmit.pdf
... and comment in the thread here:
http://forum.nasaspaceflight.com/index.php?topic=35805.0
Much obliged and thanks.
Hi IslandPlaya, still appreciating you being the first one to welcome me to this forum  :)

I wish I could, but unfortunately I can't at the moment embark into another topic.  I thank you for the gracious invitation :)
Thank you. However the topic has been nuked (maybe on my advice.)
I am currently trying to understand Hubble and Unrhu horizons as I intuit that is the theoretical key to the anomalous thrust.

It was only nuked because there was an already existing thread for it I imagine.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 08:31 pm

Dr. Rodal. I know your expertise on experimental setups.
Please could you cast your searching eyes over this please?
http://www.sifferkoll.se/sifferkoll/wp-content/uploads/2014/10/LuganoReportSubmit.pdf
... and comment in the thread here:
http://forum.nasaspaceflight.com/index.php?topic=35805.0
Much obliged and thanks.
Hi IslandPlaya, still appreciating you being the first one to welcome me to this forum  :)

I wish I could, but unfortunately I can't at the moment embark into another topic.  I thank you for the gracious invitation :)
Thank you. However the topic has been nuked (maybe on my advice.)
I am currently trying to understand Hubble and Unrhu horizons as I intuit that is the theoretical key to the anomalous thrust.

It was only nuked because there was an already existing thread for it I imagine.
No.
It was nuked because it didn't refer to space flight.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 08:32 pm
AC losses in superconductors.

http://www.bnl.gov/magnets/staff/gupta/Summer1968/0511.pdf

Hope this helps.

This is a very long answer above.

Does it make any sense, that since superconductors repel magnetic fields, they would repel their OWN magnetic field? That's why I said destructive interference. Is there a clearer term?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 08:37 pm
AC losses in superconductors.

http://www.bnl.gov/magnets/staff/gupta/Summer1968/0511.pdf

Hope this helps.
Not really.
A more modern version not out of the 60's would help.
Perhaps the 21st Century?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/08/2014 08:42 pm
Mulletron.
I have decided you need to go back to physics school.
Sorry.
We will all welcome you when you get back.
Farewell and good luck!
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 08:49 pm
Mulletron.
I have decided you need to go back to physics school.
Sorry.
We will all welcome you when you get back.
Farewell and good luck!

You're asking me questions here. Anyway, it is clear that superconductors break down in the presence of moving magnetic fields.

What kind of magnetic field do you have in the presence of AC?.......MOVING.

Edit:

Now let's play nice.
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 08:51 pm
Quote
"Superconductivity: a quantum mechanics effect for which people's intuition fails, because our intuition is built around our macro world and not the quantum world.   One would have to work out the quantum mechanics math to answer."

This is a hasty generalization.

(http://upload.wikimedia.org/wikipedia/commons/5/5e/JohnvonNeumann-LosAlamos.gif)
Title: Re: EM Drive Developments
Post by: cuddihy on 10/08/2014 08:59 pm
Take another look at http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html, Prof. McCulloch has now incorporated the Chinese data, and all the data  [Shawyer, China and NASA] is pretty well calculated by McCulloch's formula except for one experiment (out of 3 in the list) by Brady et.al. that I had pointed out is extremely anomalous (they raised the Q by a factor of 2.5 and the force came down to 1/2).  The Unruth/McCulloch formula does a great job [compared to everything else that has been offered, and look at this thread we have considered all kinds of stuff].  What is most interesting again is that McCulloch does not use fudge factors or an excessive number of parameters.  Actually McCulloch's formula is bare bones:  PowerInput, Q, frequency and the geometry: that's all folks.  :)


Where does the dielectric requirement come in to his calculation? I don't see it.
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 09:12 pm
Take another look at http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html, Prof. McCulloch has now incorporated the Chinese data, and all the data  [Shawyer, China and NASA] is pretty well calculated by McCulloch's formula except for one experiment (out of 3 in the list) by Brady et.al. that I had pointed out is extremely anomalous (they raised the Q by a factor of 2.5 and the force came down to 1/2).  The Unruth/McCulloch formula does a great job [compared to everything else that has been offered, and look at this thread we have considered all kinds of stuff].  What is most interesting again is that McCulloch does not use fudge factors or an excessive number of parameters.  Actually McCulloch's formula is bare bones:  PowerInput, Q, frequency and the geometry: that's all folks.  :)
Where does the dielectric requirement come in to his calculation? I don't see it.
By his calculation do you mean the simple calculation in McCulloch's blog last page on the EM drives [yes, of course that simple calculation based on  PowerInput, Q, frequency and the flat surfaces, only applies to a truncated cone microwave cavity under restrictive assumptions as discussed in his blog] or do you mean McCulloch inertial theory as presented in McCulloch's papers?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/08/2014 09:16 pm
What is the mechanism that destroys SC for AC currents?
Please enlighten me.
I don't think anyone really knows the mechanism behind the latest gen 2 HTSC stuff.  I think it does work for VHF however.  I have never seen any superconducting power equipment for UHF nor microwave.  DARPA had a portable HTSC ceramic supercap power storage unit some years ago that went to phase 2 that probably was UHF capable, though they were saying it was for communications.  (Yeah, I believe that!  They're looking for something to power their battlefield robots, powered exoskeletons, etc.)  If you search HTSC VHF at DARPA you'll find what little is left public on the program.  Was working with General Atomics I think.
Title: Re: EM Drive Developments
Post by: zen-in on 10/08/2014 10:50 pm
Mulletron.
I have decided you need to go back to physics school.
Sorry.
We will all welcome you when you get back.
Farewell and good luck!

You're asking me questions here. Anyway, it is clear that superconductors break down in the presence of moving magnetic fields.

What kind of magnetic field do you have in the presence of AC?.......MOVING.

Edit:

Now let's play nice.

I need to go back to physics school to and I'm a long way from understanding superconductivity.   You are right about moving magnetic fields degrading superconductor performance.   It doesn't need to be a strong field or fast moving field either.   With just a small amount of high temperature superconductor (hts) and low currents the resulting quench will cause a visible increase in liquid Nitrogen boil off.    For hts motors special configurations of the hts cable are used.  The upper limit for an AC field on hts, before quench occurs, is around 60 Hz, based on what I have read.   That would limit a motor speed to 3600 RPM.    My knowledge on this is very limited and others may have better information.  If someone can supply more information on higher frequency uses of hts I would find it very interesting.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/08/2014 11:08 pm
A follow up to JohnFornaro's questions:

Q: ""Do objects undergoing NO acceleration have inertial mass? NO"...Therefore, I take issue with the above statement.  We still don't know what the "true" orgigin of inertia is."

A: You are right, we don't know the true origin of inertia. Lots of people have ideas. I have one too. It is time.

Q: "Now, if one law of the universe can be broken, then all laws of the universe can be broken."

A: How do you figure? We're not breaking any laws here. But if we were, why the slippery slope?

Q: "If a "new universe" is being created inside a copper can, which, tho not shielded from gravity, is subject to all other universal laws, two questions occur.  How can it be called a "new universe" if subject to the inertial laws of this one?"

A: If you change any single property of a consistent universe, is it still the same universe? Or a different universe? I say a different one. Because it has different rules. A universe is defined by its rules.

Q: "Is the 45 degree angled copper can the only way this assymetrical acceleration can occur?"

A: NO, read McCulloch's paper on inertia.

Edited for grammar. Added the word we.
Title: Re: EM Drive Developments
Post by: Rodal on 10/08/2014 11:17 pm
...
I will try to embiggen my knowledge further.
Embiggen ?

Now, that's a word we don't hear in our (American) neck of the woods  :).  I had to look it up.   

You have embiggened my vocabulary.

NASA has to EMbiggen their EMDrive to EMbiggen its force output
Title: Re: EM Drive Developments
Post by: frobnicat on 10/08/2014 11:55 pm
Taking a shot at an "axion condensate dark matter" energy to force calculation.

So theory and experiment both give a reduction in "sound speed" in a dilute condensate of ~ 10^-6.  So, let's say s = < 300 m/sec, given the assumption that the "axions" "interact" via gravity at c.

Where does it come from this 10^-6 ? specific to Bose Einstein condensates ? Reduction relative to what, the speed of "interactions" (sound ?) without BE condensation ?

Quote
Using a rough experimental result of 10W => 50 micronewtons for comparison.

At 300 m/sec, I need to generate 2.5 X 10^22 phonons/sec at a power of 1.5 X 10-2 watts to generate that 50 micronewtons.

So 15 milliwatts out of 10 watts => 0.15%  (pretty high)

Edit +10^22 and phonons not photons

I don't get it, where 2.5e22 comes from ?
Trying to understand the equivalent mass of the quanta you are pushing onto
  50e-6   = 300 * mass_1_phonon*2.5e22
kg*m/s²  =  m/s *       kg     /  s       
=> mass_1_phonon = 50e-6 / (300*2.5e22) = 6.7e-30 kg = 3.7MeV  why ?
2.5e22 * 6.7e-30 = 1.7e-7 kg/s 
( We didn't need to go through the individual phonon mass, it is just 50e-6/300 as mass_flow=force/speed)
Power of a jet having mass at sending mass from its own speed is 0.5*mass_flow*speed² = 0.5*1.7e-7*300² = 7.5e-3 W
Lost a .5 factor here, but looks like I'm on the right track. You are like pushing on something at a relative speed of 300m/s : pow = force * speed = 1.5e-2 and considering there is no recoil of the medium because it's a "rigid" condensate ? But however rigid it would be, it would still need to have a certain mass : imagine an infinitly rigid slab spanning the solar system but weighing a gram, you couldn't really grab onto it to push efficiently a ship of one ton, unless sending the slab very very fast in the opposite direction.

So you have to "recruit" a mass to push onto at those efficiencies (that is, at this low characteristic speed) and this mass is on the order of 1.7e-7 kg each second. If I recall well, absolute experimentally checked upper bound (not likely) to DM density at earth orbit is about 1E6 GeV /cm^3 = 1.8e-24 kg/m^3 1.8e-15 kg/m^3
So the mass of DM to be pushed onto must be found on the order of 1e17 m^3, roughly 300km radius sphere.
How is it possible to recruit in 1s the mass of medium to be found in such a volume when the speed of sound
in said medium is 300m/s ?

There is simply not enough naturally occurring DM density to be of practical use, this is from the known gravitational bounds to density, so nothing more to be exploited could hide (in some specific kind of dark matter...)


Ahem :

so the mass of DM to be pushed onto must be found on the order of 1e8 m^3, roughly 300m radius sphere, that's within reach. Ok.

I know the discussion drifted to other considerations long time ago but I had to destroy that (sorry Notsosureofit, nothing personal, just to close all doors to classical natural DM)


Ok so it could. But it wont unless we find a way to couple with DM at better than 1e-15 event per encounter....

Now I will be attacking Shawyer's derivations.
(still of actuality)
Title: Re: EM Drive Developments
Post by: aero on 10/09/2014 12:52 am
Taking a shot at an "axion condensate dark matter" energy to force calculation.

So theory and experiment both give a reduction in "sound speed" in a dilute condensate of ~ 10^-6.  So, let's say s = < 300 m/sec, given the assumption that the "axions" "interact" via gravity at c.

Where does it come from this 10^-6 ? specific to Bose Einstein condensates ? Reduction relative to what, the speed of "interactions" (sound ?) without BE condensation ?

Quote
Using a rough experimental result of 10W => 50 micronewtons for comparison.

At 300 m/sec, I need to generate 2.5 X 10^22 phonons/sec at a power of 1.5 X 10-2 watts to generate that 50 micronewtons.

So 15 milliwatts out of 10 watts => 0.15%  (pretty high)

Edit +10^22 and phonons not photons

I don't get it, where 2.5e22 comes from ?
Trying to understand the equivalent mass of the quanta you are pushing onto
  50e-6   = 300 * mass_1_phonon*2.5e22
kg*m/s²  =  m/s *       kg     /  s       
=> mass_1_phonon = 50e-6 / (300*2.5e22) = 6.7e-30 kg = 3.7MeV  why ?
2.5e22 * 6.7e-30 = 1.7e-7 kg/s 
( We didn't need to go through the individual phonon mass, it is just 50e-6/300 as mass_flow=force/speed)
Power of a jet having mass at sending mass from its own speed is 0.5*mass_flow*speed² = 0.5*1.7e-7*300² = 7.5e-3 W
Lost a .5 factor here, but looks like I'm on the right track. You are like pushing on something at a relative speed of 300m/s : pow = force * speed = 1.5e-2 and considering there is no recoil of the medium because it's a "rigid" condensate ? But however rigid it would be, it would still need to have a certain mass : imagine an infinitly rigid slab spanning the solar system but weighing a gram, you couldn't really grab onto it to push efficiently a ship of one ton, unless sending the slab very very fast in the opposite direction.

So you have to "recruit" a mass to push onto at those efficiencies (that is, at this low characteristic speed) and this mass is on the order of 1.7e-7 kg each second. If I recall well, absolute experimentally checked upper bound (not likely) to DM density at earth orbit is about 1E6 GeV /cm^3 = 1.8e-24 kg/m^3
So the mass of DM to be pushed onto must be found on the order of 1e17 m^3, roughly 300km radius sphere.
How is it possible to recruit in 1s the mass of medium to be found in such a volume when the speed of sound
in said medium is 300m/s ?

There is simply not enough naturally occurring DM density to be of practical use, this is from the known gravitational bounds to density, so nothing more to be exploited could hide (in some specific kind of dark matter...)

I know the discussion drifted to other considerations long time ago but I had to destroy that (sorry Notsosureofit, nothing personal, just to close all doors to classical natural DM)

Now I will be attacking Shawyer's derivations.


I guess its time for my 10^7 contribution.

I've attached a current estimate of dark matter in the solar system, and for convenience converted 16.5E16 kg / AU^3 to 4.5E-17 kg/m^3.  That is quite a lot more than your number, 1.8e-24 kg/m^3 . In fact, it is almost exactly the value needed.

I do note that a drive based on this physics won't be so good much beyond Saturn. The DM mass really tails off with distance from the sun.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/09/2014 12:53 am
Considering energy theoretical aspects of this article by Shawyer (http://www.emdrive.com/IAC-08-C4-4-7.pdf) (linked to by sir Rodal) I was disappointed.

In conclusions it is claimed that
Quote from: Shawyer
Following extensive review, no contravention of the laws of the conservation of momentum and conservation of energy has been identified.

But to reach this conservation of energy (pages 5 and 6) he has to introduce a distinction between a "loaded" and "unloaded" Q factor : depending on the device having some speed or not.
- This is contrary to the equivalence principle of GR as keeping a constant thrust against earth gravity at constant altitude would be different from accelerating in deep space at 9.81m/s²
- This yield an equation (15) relating unloaded to loaded Q factor and a "mean speed" term : this mean speed is ill defined as we don't know of any frame of reference relative to which it should be measured.
- Because of this velocity term, this is contrary to inertial frame invariance (results of the equation depend on the arbitrary choice of inertial frame of reference)
- This is contrary to all experimental data that shows no sign of variation of Q in a resonant cavity depending on whether it goes fast or not (relative to what ?). Surely this would have been seen numerous times (satellites...) as this strong (halving...) non frame invariant effect appears at a few km/s in the equation for usual Q values.

Those problems are not addressed by the paper.

This doesn't hold water. I'm not trying to look any deeper as for the momentum aspect, apparently my first impression on Shawyer's theoretical skills is a shared judgement :
.../...
On the other hand, White's approach supposedly predicts thrust from a Shawyer EmDrive, while Woodward's does not.  It is generally acknowledged that Shawyer's explanation of his invention makes no sense, but that doesn't necessarily mean the invention itself doesn't work.  IIRC multiple parties have reported thrust from EmDrives, and not all of them are in China...

.../...
Most physicists are clueless when it comes to engineering, especially anyone who isn't in experiment. They simply lack the design skills to compete with engineers. Conversely, when an engineer tries to do physics, you often end up with a Roger Shawyer.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/09/2014 01:12 am
Quote
"Superconductivity: a quantum mechanics effect for which people's intuition fails, because our intuition is built around our macro world and not the quantum world.   One would have to work out the quantum mechanics math to answer."

This is a hasty generalization.

(http://upload.wikimedia.org/wikipedia/commons/5/5e/JohnvonNeumann-LosAlamos.gif)

What?  That's not me.  That's some other John.  This is me.  Accept no substitutes.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/09/2014 01:14 am
...
I will try to embiggen my knowledge further.
Embiggen ?

"Embiggen" rox.  I shall be using it in sentence forthwith.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/09/2014 01:23 am
A follow up to JohnFornaro's questions:

1) Q: ""Do objects undergoing NO acceleration have inertial mass? NO"...Therefore, I take issue with the above statement.  We still don't know what the "true" orgigin of inertia is."

A: You are right, we don't know the true origin of inertia. Lots of people have ideas. I have one too. It is time.

2a) Q: "Now, if one law of the universe can be broken, then all laws of the universe can be broken."

A: How do you figure? We're not breaking any laws here. But if we were, why the slippery slope?

2b) Q: "If a "new universe" is being created inside a copper can, which, tho not shielded from gravity, is subject to all other universal laws, two questions occur.  How can it be called a "new universe" if subject to the inertial laws of this one?"

A: If you change any single property of a consistent universe, is it still the same universe? Or a different universe? I say a different one. Because it has different rules. A universe is defined by its rules.

3) Q: "Is the 45 degree angled copper can the only way this assymetrical acceleration can occur?"

A: NO, read McCulloch's paper on inertia.

1) Thanks for the engagement.  Again, an object or particle with no acceleration has yet to be found.  Even at lo, lo, how lo can you go speeds, a massive object has inertia equal to its mass.  My objection was that we do not know, and have no evidence that inertia disappears with no acceleration.

My sense is, that you (well, one) can't go wrong by assuming that inertia exists in all frames of reference.

2a&b)  You answered "a" with "b".  You say it's a different universe, and maybe we're struggling with semantics here.  But then you go on to suggest that a "property" in the "new" universe is being changed.  We're not talking about the color of paint as a property, we're talking about fundamental properties, which in theory, we cannot change.

Whatever is happening in the copper can obeys the laws of the universe that it is embedded in.  No matter how much you embiggen it.

3)  Dang.  I knew you were going to say that.  Will try and find the time to throw an eyeball over it.  You all must be able to read at least an order of magnitute faster than I can, and I read so fast that my lips can't keep up.

4) What about Bohm's "implicate order".  Do you think it has bearing on this EM-drive and related physics?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/09/2014 01:25 am

I guess its time for my 10^7 contribution.

I've attached a current estimate of dark matter in the solar system, and for convenience converted 16.5E16 kg / AU^3 to 4.5E-17 kg/m^3.  That is quite a lot more than your number, 1.8e-24 kg/m^3 . In fact, it is almost exactly the value needed.

I do note that a drive based on this physics won't be so good much beyond Saturn. The DM mass really tails off with distance from the sun.

Yeah, I just, you know, forgot the G in GeV. Off by 9 orders of magnitude. Post corrected. Many thanks for not making myself a fool for too long.

I took a looser upper bound because I thought we would be so far from reaching the necessary mass. You numbers above background galactic DM are more precise (proven ? probable ? possible ? speculative ?). This doesn't tell where this 300m/s from Notsosureofit comes from...

Also, how could you meet DM at such low speed for a long time ? The equation for power of pushing on a medium is dependant on the speed you have in the medium, not the speed of sound of the medium. Unless there is a lump of cold DM orbiting with the earth we would encounter DM at a few km/s even on the ground. This is weakly interacting after all. Please detect DM before pushing too much on it.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/09/2014 01:48 am

I guess its time for my 10^7 contribution.

I've attached a current estimate of dark matter in the solar system, and for convenience converted 16.5E16 kg / AU^3 to 4.5E-17 kg/m^3.  That is quite a lot more than your number...

Yeah, I just, you know, forgot the G in GeV. Off by 9 orders of magnitude. Post corrected. Many thanks for not making myself a fool for too long. ...

This is weakly interacting after all. Please detect DM before pushing too much on it.

I was wondering about all the strike thrus.  Just go ahead and edit it so it reads better.  Add a "mea culpa" at the end.  I'm not gonna ask for an apoligy, 'cause I drop zeros all the time.

It's true tho, that you can't push very hard on something that is so rare.  But then I got confused.  You're not talking about "DM fusion", right?

Ai chihuahua.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/09/2014 01:56 am

I guess its time for my 10^7 contribution.

I've attached a current estimate of dark matter in the solar system, and for convenience converted 16.5E16 kg / AU^3 to 4.5E-17 kg/m^3.  That is quite a lot more than your number...

Yeah, I just, you know, forgot the G in GeV. Off by 9 orders of magnitude. Post corrected. Many thanks for not making myself a fool for too long. ...

This is weakly interacting after all. Please detect DM before pushing too much on it.

I was wondering about all the strike thrus.  Just go ahead and edit it so it reads better.  Add a "mea culpa" at the end.  I'm not gonna ask for an apoligy, 'cause I drop zeros all the time.

It's true tho, that you can't push very hard on something that is so rare.  But then I got confused.  You're not talking about "DM fusion", right?

Ai chihuahua.

http://samos.martech.fsu.edu/chapters/chapters/md.PDF
http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 02:00 am
A follow up to JohnFornaro's questions:

1) Q: ""Do objects undergoing NO acceleration have inertial mass? NO"...Therefore, I take issue with the above statement.  We still don't know what the "true" orgigin of inertia is."

A: You are right, we don't know the true origin of inertia. Lots of people have ideas. I have one too. It is time.

2a) Q: "Now, if one law of the universe can be broken, then all laws of the universe can be broken."

A: How do you figure? We're not breaking any laws here. But if we were, why the slippery slope?

2b) Q: "If a "new universe" is being created inside a copper can, which, tho not shielded from gravity, is subject to all other universal laws, two questions occur.  How can it be called a "new universe" if subject to the inertial laws of this one?"

A: If you change any single property of a consistent universe, is it still the same universe? Or a different universe? I say a different one. Because it has different rules. A universe is defined by its rules.

3) Q: "Is the 45 degree angled copper can the only way this assymetrical acceleration can occur?"

A: NO, read McCulloch's paper on inertia.

1) Thanks for the engagement.  Again, an object or particle with no acceleration has yet to be found.  Even at lo, lo, how lo can you go speeds, a massive object has inertia equal to its mass.  My objection was that we do not know, and have no evidence that inertia disappears with no acceleration.

My sense is, that you (well, one) can't go wrong by assuming that inertia exists in all frames of reference.

2a&b)  You answered "a" with "b".  You say it's a different universe, and maybe we're struggling with semantics here.  But then you go on to suggest that a "property" in the "new" universe is being changed.  We're not talking about the color of paint as a property, we're talking about fundamental properties, which in theory, we cannot change.

Whatever is happening in the copper can obeys the laws of the universe that it is embedded in.  No matter how much you embiggen it.

3)  Dang.  I knew you were going to say that.  Will try and find the time to throw an eyeball over it.  You all must be able to read at least an order of magnitute faster than I can, and I read so fast that my lips can't keep up.

4) What about Bohm's "implicate order".  Do you think it has bearing on this EM-drive and related physics?

Quoting myself: "Place yourself in intergalactic space, outside of any dominant gravity well (except the universe itself) you would experience acceleration (very small acceleration) only with respect to the universe at large.

The algorithm I put together a few pages back is a thought experiment about what NO acceleration would be like. The notion of NO acceleration is immaterial in reality. Just very low accelerations are real. Given the perceived dipole moment of the CMB, there cannot ever be exactly 0 acceleration."

The paper in question is the 2013 one, near the end where he's talking about metamaterials.

I don't know anything about Bohm's implicate order. I'll check it out.
Title: Re: EM Drive Developments
Post by: aero on 10/09/2014 03:02 am

I guess its time for my 10^7 contribution.

I've attached a current estimate of dark matter in the solar system, and for convenience converted 16.5E16 kg / AU^3 to 4.5E-17 kg/m^3.  That is quite a lot more than your number, 1.8e-24 kg/m^3 . In fact, it is almost exactly the value needed.

I do note that a drive based on this physics won't be so good much beyond Saturn. The DM mass really tails off with distance from the sun.

Yeah, I just, you know, forgot the G in GeV. Off by 9 orders of magnitude. Post corrected. Many thanks for not making myself a fool for too long.

I took a looser upper bound because I thought we would be so far from reaching the necessary mass. You numbers above background galactic DM are more precise (proven ? probable ? possible ? speculative ?). This doesn't tell where this 300m/s from Notsosureofit comes from...

Also, how could you meet DM at such low speed for a long time ? The equation for power of pushing on a medium is dependant on the speed you have in the medium, not the speed of sound of the medium. Unless there is a lump of cold DM orbiting with the earth we would encounter DM at a few km/s even on the ground. This is weakly interacting after all. Please detect DM before pushing too much on it.


From an article I posted a couple days ago (like 30 pages back), natural coupling of DM with photons may be on the order of the hubble constant, ~10^-18/s . (dp/dt = -Hp). I have a feeling that this is to weak to do us any good and haven't tried to calculate thrust using this coupling though I do note that the photon density within the cavity is much higher than photon density in freespace.

I've been looking for a mechanism that would create Axions within the cavity perhaps via the dual photon interaction. Frankly, my problem is the heavy physics and math, I go cross-eyed just trying to read the background papers, let alone trying to understand the process. Bunched or Clumped photons may play a role. Of course if the cavity actually created Axions then we might be back to the question of Energy conservation but we should solve one mystery at a time.

I'll keep looking but don't expect anything before this thread hits 300 pages.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 03:15 am
Apart from my drawing ability. Tear it apart.

I'm having trouble resolving why it would want to move. Even with the internal imbalances. As mentioned here: http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

"The leap is that the only way to conserve force (or conserve momentum) is to have an equal force pushing the whole system the other way towards the narrow end."

Why would it want to move? When I looked at that question very critically I can't answer it.

What role does the dielectric specifically play if any in converting momentum from the particles (with an energy gradient over the length of the device) to linear motion of the whole system?

Assuming this thing isn't expelling any reaction mass. What is pushing it?

Can anyone explain why it would move?
Is this where the Lamb Shift comes into play?
There isn't anything coming out of the emdrive to balance what is happening inside vs outside.

Seems like it would be better suited to spinning a generator internally.

Edit:
Q factor of outside must matter too?
Think I got it. Solely by the definition of Inertia it would be harder to push one way vs the other with rf off. Barely. By virtue of the acceleration of the universe the emdrive is always accelerating with respect to the universe. It has less resistance to accelerate toward the small end. In deep space it would move slowly on its own. Very slowly. It would take forever to get up to a useful velocity.

Turn rf on. The inertial bias of the system is magnified.

Inertia is never lowered anywhere though.
Because of this the outside has to be designed to take advantage of the unbalanced inertial moment.

The universe and the radiation in the universe is what pushes it!

That means q factor outside is important too. So is its optical reflection and absorption.

Where did I go wrong? Inertia isn't lowered and I'm confused again. Harder to push in one direction vs another doesn't mean easier to push.

Okay, now I'm going back to physics school. I need to figure out who this bleeping thing could ever move! Looks like we're back to it reacting against the QV again.......somehow.

http://arxiv-web3.library.cornell.edu/abs/1404.5990 (what I've been saying)
http://arxiv.org/abs/0908.4390

Title: Re: EM Drive Developments
Post by: zen-in on 10/09/2014 04:49 am
Re: performance of superconductors with AC and microwaves

I have found a Google book that describes low temperature and high temperature superconductor microwave resonators.  So this shoots a hole in my claim that superconductors are no good above 60 Hz.   However for slowly changing magnetic fields hst quench does occur quite easily.
books.google.com/books?isbn=0824755308 (http://books.google.com/books?isbn=0824755308)
Here is a graph from that book showing resistance vs frequency for Cu and several superconductors.
Title: Re: EM Drive Developments
Post by: aero on 10/09/2014 05:15 am
Question - Is there any way to know the shapes of the standing waves within the cavity, with and without the resonator?
See here for a curved truncated cone:  http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html
for the cavity itself (not the dielectric resonator)


Observe that the ends, however are not flat in this solution for 1/r not equal to zero.  Shawyer's and NASA truncated cone have flat ends with 1/r = 0 (r-> Infinity at ends)

I like his drawings of the E and M fields in the cavity. What would be more helpful though would be if he made a few drawings separated by, say 30 degrees in phase, then put them together, time properly in a .gif image so I could see how the fields, and electromagnetic forces move within the cavity. I don't know if that would tell me anything but it might help my understanding and especially if he could put the electric field and magnetic field in cavities side by side in the .gif, with a representative particle of some sort.  Oh, and I'd like a Unicorn, too :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 01:06 pm
...
Can anyone explain why it would move?
...
McCulloch stated << the microwaves bouncing around within the cavity have inertial mass (em radiation does: that's why it can push a Solar sail) and their inertia is determined by MiHsC (quantised inertia). In MiHsC the Unruh waves are allowed only if they fit exactly within the Hubble horizon or within a local Rindler horizon, .. if the cavity wall in this case was acting like a horizon... then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.as a microwave beam goes from the narrow end to the wide end it gains inertial mass. Now I can try something I've used before (for the Tajmar effect [see http://arxiv.org/abs/1106.3266 ]) and say, in order to still conserve momentum (mass*velocity) for the whole system, if mass goes up then velocity must go down, and the only way to achieve that is to have the whole structure move towards the narrow end.>>
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 01:15 pm
Also notice that McCulloch states [http://arxiv.org/abs/1106.3266] <<MiHsC (Eq. 1) violates the equivalence principle, but not in a way that could be detected by the usual [Cavendish] torsion balance experiment. These experiments measure the differential attraction of two balls on a cross bar suspended on wire, towards distant masses by detecting tiny twists in the wire (eg: [12]). With MiHsC these two balls would have equal accelerations with respect to the distant masses (being rigidly connected) so their inertial masses would be modified equally by MiHsC, and there will be no twist in the wire, and no apparent violation of equivalance.>>
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 01:17 pm
...
Can anyone explain why it would move?
...
McCulloch stated << the microwaves bouncing around within the cavity have inertial mass (em radiation does: that's why it can push a Solar sail) and their inertia is determined by MiHsC (quantised inertia). In MiHsC the Unruh waves are allowed only if they fit exactly within the Hubble horizon or within a local Rindler horizon, .. if the cavity wall in this case was acting like a horizon... then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.as a microwave beam goes from the narrow end to the wide end it gains inertial mass. Now I can try something I've used before (for the Tajmar effect [see http://arxiv.org/abs/1106.3266 ]) and say, in order to still conserve momentum (mass*velocity) for the whole system, if mass goes up then velocity must go down, and the only way to achieve that is to have the whole structure move towards the narrow end.>>

I know he says that. I just modeled that (what he said) in my most recent huge post and it failed. It seems that MIHSC describes everything EXCEPT the final reaction mechanism. The reason why it moves. He maintained himself it is a leap. I tried to push the "I believe button" and it still didn't work. This thing doesn't expel any reaction mass. So now I'm back in line with Dr. White. The question is how?

Edit: You can't violate the equivalence principal, nomatter how it is detected or semantics.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 01:22 pm
...
Can anyone explain why it would move?
...
McCulloch stated << the microwaves bouncing around within the cavity have inertial mass (em radiation does: that's why it can push a Solar sail) and their inertia is determined by MiHsC (quantised inertia). In MiHsC the Unruh waves are allowed only if they fit exactly within the Hubble horizon or within a local Rindler horizon, .. if the cavity wall in this case was acting like a horizon... then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.as a microwave beam goes from the narrow end to the wide end it gains inertial mass. Now I can try something I've used before (for the Tajmar effect [see http://arxiv.org/abs/1106.3266 ]) and say, in order to still conserve momentum (mass*velocity) for the whole system, if mass goes up then velocity must go down, and the only way to achieve that is to have the whole structure move towards the narrow end.>>

I know he says that. I just modeled that (what he said) in my most recent huge post and it failed. He maintained himself it is a leap. I tried to push the "I believe button" and it still didn't work. This thing doesn't expel any reaction mass. So now I'm back in line with Dr. White. The question is how?
Can you explain in as few words as possible, what alternative explanation you have for conserving momentum (instead of McCulloch's proposal to have a force pushing towards the narrow end) that conserves momentum without the EM drive accelerating?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 01:24 pm
...
Can anyone explain why it would move?
...
McCulloch stated << the microwaves bouncing around within the cavity have inertial mass (em radiation does: that's why it can push a Solar sail) and their inertia is determined by MiHsC (quantised inertia). In MiHsC the Unruh waves are allowed only if they fit exactly within the Hubble horizon or within a local Rindler horizon, .. if the cavity wall in this case was acting like a horizon... then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.as a microwave beam goes from the narrow end to the wide end it gains inertial mass. Now I can try something I've used before (for the Tajmar effect [see http://arxiv.org/abs/1106.3266 ]) and say, in order to still conserve momentum (mass*velocity) for the whole system, if mass goes up then velocity must go down, and the only way to achieve that is to have the whole structure move towards the narrow end.>>

I know he says that. I just modeled that (what he said) in my most recent huge post and it failed. He maintained himself it is a leap. I tried to push the "I believe button" and it still didn't work. This thing doesn't expel any reaction mass. So now I'm back in line with Dr. White. The question is how?
Can you explain in as few words as possible, what alternative explanation you have for conserving momentum (instead of McCulloch's proposal to have a force pushing the whole systemtowards the narrow end)  that will conserve momentum with the EM drive not accelerating?

We have to react against something. That something isn't blocked by the boundary conditions of the enclosed cavity.

 Looks like we're back to it reacting against the QV again.......somehow.

http://arxiv-web3.library.cornell.edu/abs/1404.5990 (what I've been saying) Maybe this way.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 01:26 pm
...
Can anyone explain why it would move?
...
McCulloch stated << the microwaves bouncing around within the cavity have inertial mass (em radiation does: that's why it can push a Solar sail) and their inertia is determined by MiHsC (quantised inertia). In MiHsC the Unruh waves are allowed only if they fit exactly within the Hubble horizon or within a local Rindler horizon, .. if the cavity wall in this case was acting like a horizon... then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.as a microwave beam goes from the narrow end to the wide end it gains inertial mass. Now I can try something I've used before (for the Tajmar effect [see http://arxiv.org/abs/1106.3266 ]) and say, in order to still conserve momentum (mass*velocity) for the whole system, if mass goes up then velocity must go down, and the only way to achieve that is to have the whole structure move towards the narrow end.>>

I know he says that. I just modeled that (what he said) in my most recent huge post and it failed. He maintained himself it is a leap. I tried to push the "I believe button" and it still didn't work. This thing doesn't expel any reaction mass. So now I'm back in line with Dr. White. The question is how?
Can you explain in as few words as possible, what alternative explanation you have for conserving momentum (instead of McCulloch's proposal to have a force pushing the whole systemtowards the narrow end)  that will conserve momentum with the EM drive not accelerating?

We have to react against something. That something isn't blocked by the boundary conditions of the enclosed cavity.

 Looks like we're back to it reacting against the QV again.......somehow.

http://arxiv-web3.library.cornell.edu/abs/1404.5990 (what I've been saying) Maybe this way.
Sorry, I don't understand you.  Do you have an alternative explanation  for conserving momentum (instead of McCulloch's proposal to have a force pushing towards the narrow end) that conserves momentum without the EM drive accelerating?, yes or no ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 01:29 pm
...
Can anyone explain why it would move?
...
McCulloch stated << the microwaves bouncing around within the cavity have inertial mass (em radiation does: that's why it can push a Solar sail) and their inertia is determined by MiHsC (quantised inertia). In MiHsC the Unruh waves are allowed only if they fit exactly within the Hubble horizon or within a local Rindler horizon, .. if the cavity wall in this case was acting like a horizon... then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.as a microwave beam goes from the narrow end to the wide end it gains inertial mass. Now I can try something I've used before (for the Tajmar effect [see http://arxiv.org/abs/1106.3266 ]) and say, in order to still conserve momentum (mass*velocity) for the whole system, if mass goes up then velocity must go down, and the only way to achieve that is to have the whole structure move towards the narrow end.>>

I know he says that. I just modeled that (what he said) in my most recent huge post and it failed. He maintained himself it is a leap. I tried to push the "I believe button" and it still didn't work. This thing doesn't expel any reaction mass. So now I'm back in line with Dr. White. The question is how?
Can you explain in as few words as possible, what alternative explanation you have for conserving momentum (instead of McCulloch's proposal to have a force pushing the whole systemtowards the narrow end)  that will conserve momentum with the EM drive not accelerating?

We have to react against something. That something isn't blocked by the boundary conditions of the enclosed cavity.

 Looks like we're back to it reacting against the QV again.......somehow.

http://arxiv-web3.library.cornell.edu/abs/1404.5990 (what I've been saying) Maybe this way.
Sorry, I don't understand you.  Do you have an alternative explanation  for conserving momentum (instead of McCulloch's proposal to have a force pushing towards the narrow end) that conserves momentum without the EM drive accelerating?, yes or no ?

I just said it. Regardless of if you understand me. Yes.

Listen, if you have an object with a differential of inertia inside of it. How does that make it want to move? How are the conditions inside the cavity communicated (its inertial differences inside, and the state of its particles as a result) with the universe outside of the cavity, so that the thing is compelled to move? It isn't just as simple as "just because it does." There has to be a mechanism for that to happen.

Edit:
Put more simply, how is linear momentum transferred from inside to outside, if nothing leaves that cavity? It can only do so by something that is both INSIDE and OUTSIDE the cavity..........OR an asymmetric force acting on the outside of the cavity.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 01:35 pm
...
Can anyone explain why it would move?
...
McCulloch stated << the microwaves bouncing around within the cavity have inertial mass (em radiation does: that's why it can push a Solar sail) and their inertia is determined by MiHsC (quantised inertia). In MiHsC the Unruh waves are allowed only if they fit exactly within the Hubble horizon or within a local Rindler horizon, .. if the cavity wall in this case was acting like a horizon... then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.as a microwave beam goes from the narrow end to the wide end it gains inertial mass. Now I can try something I've used before (for the Tajmar effect [see http://arxiv.org/abs/1106.3266 ]) and say, in order to still conserve momentum (mass*velocity) for the whole system, if mass goes up then velocity must go down, and the only way to achieve that is to have the whole structure move towards the narrow end.>>

I know he says that. I just modeled that (what he said) in my most recent huge post and it failed. He maintained himself it is a leap. I tried to push the "I believe button" and it still didn't work. This thing doesn't expel any reaction mass. So now I'm back in line with Dr. White. The question is how?
Can you explain in as few words as possible, what alternative explanation you have for conserving momentum (instead of McCulloch's proposal to have a force pushing the whole systemtowards the narrow end)  that will conserve momentum with the EM drive not accelerating?

We have to react against something. That something isn't blocked by the boundary conditions of the enclosed cavity.

 Looks like we're back to it reacting against the QV again.......somehow.

http://arxiv-web3.library.cornell.edu/abs/1404.5990 (what I've been saying) Maybe this way.
Sorry, I don't understand you.  Do you have an alternative explanation  for conserving momentum (instead of McCulloch's proposal to have a force pushing towards the narrow end) that conserves momentum without the EM drive accelerating?, yes or no ?

I just said it. Regardless of if you understand me. Yes.

Listen, if you have an object with a differential of inertia inside of it. How does that make it want to move? How are the conditions inside the cavity communicated (its inertial differences inside, and the state of its particles as a result) with the universe outside of the cavity, so that the thing is compelled to move? It isn't just as simple as "just because it does." There has to be a mechanism for that to happen.
Well I still don't see your alternative explanation for how you conserve momentum under McCulloch's assumption.  Maybe I need some more coffee to wake up.  What I see is that you are not satisfied with the explanation as to what makes it move.  The answer to that is simply conservation of momentum.

It looks like your main problem with McCulloch's theory is what makes it move under his assumptions.
To me that's not the main problem (I find the answer: because of momentum conservation to be sastisfactory).
To me the main problem is why should the microwave cavity copper walls have to act as a Rindler horizon?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 01:40 pm
...
Can anyone explain why it would move?
...
McCulloch stated << the microwaves bouncing around within the cavity have inertial mass (em radiation does: that's why it can push a Solar sail) and their inertia is determined by MiHsC (quantised inertia). In MiHsC the Unruh waves are allowed only if they fit exactly within the Hubble horizon or within a local Rindler horizon, .. if the cavity wall in this case was acting like a horizon... then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.as a microwave beam goes from the narrow end to the wide end it gains inertial mass. Now I can try something I've used before (for the Tajmar effect [see http://arxiv.org/abs/1106.3266 ]) and say, in order to still conserve momentum (mass*velocity) for the whole system, if mass goes up then velocity must go down, and the only way to achieve that is to have the whole structure move towards the narrow end.>>

I know he says that. I just modeled that (what he said) in my most recent huge post and it failed. He maintained himself it is a leap. I tried to push the "I believe button" and it still didn't work. This thing doesn't expel any reaction mass. So now I'm back in line with Dr. White. The question is how?
Can you explain in as few words as possible, what alternative explanation you have for conserving momentum (instead of McCulloch's proposal to have a force pushing the whole systemtowards the narrow end)  that will conserve momentum with the EM drive not accelerating?

We have to react against something. That something isn't blocked by the boundary conditions of the enclosed cavity.

 Looks like we're back to it reacting against the QV again.......somehow.

http://arxiv-web3.library.cornell.edu/abs/1404.5990 (what I've been saying) Maybe this way.
Sorry, I don't understand you.  Do you have an alternative explanation  for conserving momentum (instead of McCulloch's proposal to have a force pushing towards the narrow end) that conserves momentum without the EM drive accelerating?, yes or no ?

I just said it. Regardless of if you understand me. Yes.

Listen, if you have an object with a differential of inertia inside of it. How does that make it want to move? How are the conditions inside the cavity communicated (its inertial differences inside, and the state of its particles as a result) with the universe outside of the cavity, so that the thing is compelled to move? It isn't just as simple as "just because it does." There has to be a mechanism for that to happen.
Well I still don't see your alternative explanation for how you conserve momentum under McCulloch's assumption.  Maybe I need some more coffee to wake up.  What I see is that you are not satisfied with the explanation as to what makes it move.  The answer to that is simply conservation of momentum.

It looks like your main problem with McCulloch's theory is what makes it move under his assumptions.
To me that's not the main problem (I find the answer: because of momentum conservation to be sastisfactory).
To me the main problem is why should the microwave cavity copper walls have to act as a Rindler horizon?

MiHSC appears to be consistent (IMHO) with every aspect of this except the final reaction, which would need to be classical mechanics. Equal and opposite reactions (like rocket reaction chambers) are not MiHSC.

The Rindler horizon is not the copper walls. It is a wall of causality behind the device. Thanks for listening. I enjoy our discussions and I think we're furthering emdrive as a result.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 01:44 pm
...
The Rindler horizon is not the copper walls. It is a wall of causality behind the device.

No. That contradicts what Prof. McCulloch wrote:

<<.. what if the cavity wall in this case was acting like a horizon? Well, then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.>>

Prof. McCulloch wrote that his assumption is that the cavity walls are acting like a horizon. That's his assumption.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 01:47 pm
...
The Rindler horizon is not the copper walls. It is a wall of causality behind the device.

No. That contradicts what Prof. McCulloch wrote:

<<.. what if the cavity wall in this case was acting like a horizon? Well, then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.>>

Prof. McCulloch wrote that his assumption is that the cavity walls are acting like a horizon. That's his assumption.

Would fit between the cavity walls and the Rindler Horizon. Hold on. Finding the sources again.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 01:50 pm
...
The Rindler horizon is not the copper walls. It is a wall of causality behind the device.

No. That contradicts what Prof. McCulloch wrote:

<<.. what if the cavity wall in this case was acting like a horizon? Well, then the microwaves at the wide end would have more inertia than those at the narrow end since more Unruh waves would fit.>>

Prof. McCulloch wrote that his assumption is that the cavity walls are acting like a horizon. That's his assumption.

Would fit between the cavity walls and the Rindler Horizon. Hold on. Finding the sources again.
It looks like you have been working under another assumption than Prof. McCulloch's.

I have posed the question to him (in his blog) as to what is his basis to assume that the microwave cavity copper walls can act like a Hubble or a Rindler horizon.  We'll see what he answers.

Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 01:52 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

http://physics.stackexchange.com/questions/54313/does-unruh-radiation-replace-the-cosmic-horizon-radiation


Anyway my take on Rindler Horizons is that it is an apparent event horizon. Defined as variable with your velocity. The waves that fit or don't fit are between the walls of your particle and the Rindler horizon, which gets closer the faster you go.


Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 01:53 pm
(http://lowres.cartoonstock.com/transport-car-auto-automobile-drive-driving-rde2400_low.jpg)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 01:55 pm
I think I'm on board with him on Rindler Horzons, just the reaction producing motion. I can't figure out how the Unruh radiation could push you if that were the case. There is less Unruh radiation behind you than in front.......Yeah in ref to your pic you just posted. The horizon in front of you, I consider as infinity. You can't catch it. The one behind you gets closer and closer to you as you get faster and faster. Just like you get with length contraction in SR.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 01:56 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

http://physics.stackexchange.com/questions/54313/does-unruh-radiation-replace-the-cosmic-horizon-radiation


Anyway my take on Rindler Horizons is that it is an apparent event horizon. Defined as variable with your velocity. The waves that fit or don't fit are between the walls of your particle and the Rindler horizon, which gets closer the faster you go.

What needs "peer review" is the assumption that the microwave cavity copper walls can act like a Hubble or a Rindler horizon [please notice that as of late Prof. McCulloch has been writing Hubble horizon -- not Rindler horizon--].
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 01:58 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

http://physics.stackexchange.com/questions/54313/does-unruh-radiation-replace-the-cosmic-horizon-radiation


Anyway my take on Rindler Horizons is that it is an apparent event horizon. Defined as variable with your velocity. The waves that fit or don't fit are between the walls of your particle and the Rindler horizon, which gets closer the faster you go.

What needs "peer review" is the assumption that the microwave cavity copper walls can act like a Hubble or a Rindler horizon [please notice that as of late Prof. McCulloch has been writing Hubble horizon -- not Rindler horizon--].

Well the Hubble horizon is all around you. Rindler horizon is behind you. You can't see the Hubble horizon behind you through the Rindler horizon. He said that in the forum post I just shared. Quoted below.

Edit:
Quote:

"Thank you for your interesting question. The following is what I assumed in the paper. If you accelerate to the right, the Rindler horizon to your left is a boundary beyond which things are in principle unobservable for you. So, as soon as the nearer Rindler horizon forms, the far cosmic horizon behind it becomes unobservable and therefore (following the attitude of Mach) irrelevant. I assumed that the distance to the cosmic horizon on the right remains the same. I hope this answers your questions. It probably raises a lot of new ones!"
Title: Re: EM Drive Developments
Post by: frobnicat on 10/09/2014 01:59 pm

I guess its time for my 10^7 contribution.

I've attached a current estimate of dark matter in the solar system, and for convenience converted 16.5E16 kg / AU^3 to 4.5E-17 kg/m^3.  That is quite a lot more than your number...

Yeah, I just, you know, forgot the G in GeV. Off by 9 orders of magnitude. Post corrected. Many thanks for not making myself a fool for too long. ...

This is weakly interacting after all. Please detect DM before pushing too much on it.

I was wondering about all the strike thrus.  Just go ahead and edit it so it reads better.  Add a "mea culpa" at the end.  I'm not gonna ask for an apoligy, 'cause I drop zeros all the time.

It strikes through the first (erroneous) version like dark matter, you know, the strikes are not really interacting. In a few hours it will be buried under 50 or 100 posts so... next time I do a blunder I will do the mea culpa. If we are to publish in peer reviewed paper I'll have to rephrase the whole thing anyway  ;D

Quote
It's true tho, that you can't push very hard on something that is so rare.  But then I got confused.  You're not talking about "DM fusion", right?

Ai chihuahua.

No, it was about using naturally occurring DM mass "as is", for its momentum, not using its energy (equivalent mass) content (by fusion or other hypothetical "burning" mass->energy method)

Ay Caramba !
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 02:01 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

http://physics.stackexchange.com/questions/54313/does-unruh-radiation-replace-the-cosmic-horizon-radiation


Anyway my take on Rindler Horizons is that it is an apparent event horizon. Defined as variable with your velocity. The waves that fit or don't fit are between the walls of your particle and the Rindler horizon, which gets closer the faster you go.

What needs "peer review" is the assumption that the microwave cavity copper walls can act like a Hubble or a Rindler horizon [please notice that as of late Prof. McCulloch has been writing Hubble horizon -- not Rindler horizon--].

Well the Hubble horizon is all around you. Rindler horizon is behind you. You can't see the Hubble horizon behind you through the Rindler horizon. He said that in the forum post I just shared.


http://physicsfromtheedge.blogspot.it/2014_10_01_archive.html <<What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length (as they are in this case)?>>
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 02:06 pm
http://arxiv.org/pdf/1302.2775v1.pdf

This paper needs accelerated peer review.

http://physics.stackexchange.com/questions/54313/does-unruh-radiation-replace-the-cosmic-horizon-radiation


Anyway my take on Rindler Horizons is that it is an apparent event horizon. Defined as variable with your velocity. The waves that fit or don't fit are between the walls of your particle and the Rindler horizon, which gets closer the faster you go.

What needs "peer review" is the assumption that the microwave cavity copper walls can act like a Hubble or a Rindler horizon [please notice that as of late Prof. McCulloch has been writing Hubble horizon -- not Rindler horizon--].

Well the Hubble horizon is all around you. Rindler horizon is behind you. You can't see the Hubble horizon behind you through the Rindler horizon. He said that in the forum post I just shared.


http://physicsfromtheedge.blogspot.it/2014_10_01_archive.html <<What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length (as they are in this case)?>>

"What if the resonant cavity walls acted like a Hubble horizon....."

It does. One side of the horizon. Every horizon has more than one side. Go walk outside and see. Or imagine yourself in a black hole. The unruh waves fit within the bounds of the horizon.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 02:09 pm
Going to Arizona to see whether I can get a sense of Yuma.

I'm taking my banjo and my microwave with me.

I'll take a look at the horizons in front of me and behind me while I drive to Yuma. 
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 02:10 pm
MiHsC if proven correct would be the biggest thing since GR. It would essentially unify quantum mechanics and general relativity, answer many open questions in physics, which he blogs about, and allow emdrive to work too.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 02:14 pm
... imagine yourself in a black hole. The unruh waves fit within the bounds of the horizon.

To quote astrophysicist Marshall Eubanks (from an exchange I had with him in the MIT Alumni Group in LinkedIN):

<< The Unruh effect is very similar to the Hawking radiation - suppose you were suspended over a black hole event horizon - you would be accelerated _and_ you would see the Hawking radiation (assuming it exists, etc.) So, if you are just accelerated it makes sense that you would see the same Hawking radiation (and that's the Unruh effect). If you think about it, it's a quantum gravity extension of the principle of equivalence - in other words, acceleration by gravity and by rocketship still do the same thing.

Another way to think of this is that, if you are in a Minskowski space time, there is no horizon, but when you accelerate, you are in a Rindler space-time, which means that you cannot see all quantum states, and so what you do see are mixed states, and these have a temperature. Now, how do the walls of the container act as a horizon ? In other words, when I read "What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length (as they are in this case)? " I simply think, why? Why should a copper and brass waveguide act like an event horizon? Either I am missing something, or it's a bad analogy.>>

I added bold letters for emphasis
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 02:29 pm
http://m.phys.org/news/2011-07-gyroscope-unexplained-due-inertia.html

Not comparable.

The ring and the gyro are 2 physical systems, separate, but in common with the universe.

Emdrive is 2 separate physical systems one inside the other. In series.


Also there is no supercooled rotating anything in emdrive. Interesting effect and I don't doubt it wrt rotating objects, but not applicable to emdrive.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 02:34 pm
Great, here is McCulloch's answer to why the EmDrive walls might make an event horizon:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

What gave you the intuition that the resonant cavity copper walls could possibly act like a Hubble horizon, especially for Unruh waves of a similar length? What enables a copper cavity to act like an event horizon? Can you provide an analogy or some physical reason for the cavity walls to act like a Hubble horizon? Thanks
9 October 2014 04:47 

 Mike McCulloch said...

OK. This is why I'm thinking the EmDrive walls might make a horizon: MiHsC assumes that inertia is caused by Unruh waves and the Hubble horizon is a boundary for information so all patterns within the cosmos must close there otherwise they let us deduce what lies beyond (this looks like a Hubble-scale Casimir effect) this includes the Unruh waves, so it affects inertia. Now, for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field, so the Unruh wave patterns have to close at the wall just as at the Hubble horizon (but for a different reason), so we have a mini-MiHsC going on. In both cosmic & mini cases it seems to explain anomalies.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 02:38 pm
His ideas sold me the steak but not the whole cow.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 02:41 pm
Nobody is arguing with you over the walls of the cavity being part of the rindler horizon. The unruh waves fit between the walls of the cavity and the approaching rindler horizon.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 02:42 pm
His ideas sold me the steak but not the whole cow.
OK, but he clearly states that his assumption is that the copper walls are acting as an event horizon, and he gives his reason why:

<<the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field, so the Unruh wave patterns have to close at the wall just as at the Hubble horizon (but for a different reason)>>
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/09/2014 02:42 pm
http://m.phys.org/news/2011-07-gyroscope-unexplained-due-inertia.html

Not comparable.

The ring and the gyro are 2 physical systems, separate, but in common with the universe.

Emdrive is 2 separate physical systems one inside the other. In series.


Also there is no supercooled rotating anything in emdrive.

From the link:  "causing the gyroscope’s inertial mass to decrease to less than its gravitational mass."
Just noting, all of GR stands on EEP and EEP says that inertial and gravitational mass are always the same.  There are weak and strong readings of this, but what Dr. McCulloch is proposing would seem to imply all of GR is wrong, as EEP is wrong.  Or am I overstating the case?

I do however appreciate when anyone tries to make sense of Tajmar's findings.  It was a big surprise that he got the same readings both with and without the superconducting ring that was supposed to be causing this effect.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 02:49 pm
http://m.phys.org/news/2011-07-gyroscope-unexplained-due-inertia.html

Not comparable.

The ring and the gyro are 2 physical systems, separate, but in common with the universe.

Emdrive is 2 separate physical systems one inside the other. In series.


Also there is no supercooled rotating anything in emdrive.

From the link:  "causing the gyroscope’s inertial mass to decrease to less than its gravitational mass."
Just noting, all of GR stands on EEP and EEP says that inertial and gravitational mass are always the same.  There are weak and strong readings of this, but what Dr. McCulloch is proposing would seem to imply all of GR is wrong, as EEP is wrong.  Or am I overstating the case?

I do however appreciate when anyone tries to make sense of Tajmar's findings.  It was a big surprise that he got the same readings both with and without the superconducting ring that was supposed to be causing this effect.

He is proposing that EEP is wrong. So am I. EEP falls apart under very very low accelerations.

EEP is an illusion because it is true MOST of the time.

EEP is right most of the time.

Mach's ideas were informed by the notion of, if you can't observe it, it is insignificant. That was a very big mistake and that is why everyone believes inertial mass is the same as gravitational mass ALL OF THE TIME.

It clearly is not.

Also, somehow, Mach's generalizations about the origins of inertial mass, which informed Einstein only in principle by loose association with Mach's ideas, became a strong equivalence that should not be there.

A generalization, which dismisses what which you can't observe cannot inform a strong equivalence.

Tests of the equivalence principle pass every single time here and now. Not at the edges of our galaxy and beyond.

His test of the Tajmar effect is analogous to the Nordtvedt effect. (difference is angular vs linear)

Nobody is arguing with you over the walls of the cavity being part of the rindler horizon. The unruh waves fit between the walls of the cavity and the approaching rindler horizon.


The rindler sphere is defined by the boundaries of the cavity *(horizon 1) and the approaching Rindler horizon (horizon 2).
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 03:02 pm
GR doesn't have to be wrong in order for EEP to not fit every situation. Especially artificial situations.

"The rindler sphere is defined by the boundaries of the cavity *(horizon 1) and the approaching Rindler horizon (horizon 2)."

This new rindler sphere I just described denotes a new rindler sphere. A whole new variable.

There are 2 rindler spheres, well ellipses is more accurate. Squashed spheres then. They share an arc. The one as I drew and the one as I described. I need to add an arc to the drawing.

Thanks!

Edit:

Added pic with changes. Close enough.

It seems evident to me that MIHSC describes only the inertia component of emdrive which then enables Dr. White's ideas of thrust interactions.

Prove me wrong.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/09/2014 03:56 pm

I guess its time for my 10^7 contribution.

I've attached a current estimate of dark matter in the solar system, and for convenience converted 16.5E16 kg / AU^3 to 4.5E-17 kg/m^3.  That is quite a lot more than your number...

Yeah, I just, you know, forgot the G in GeV. Off by 9 orders of magnitude. Post corrected. Many thanks for not making myself a fool for too long. ...

This is weakly interacting after all. Please detect DM before pushing too much on it.

I was wondering about all the strike thrus.  Just go ahead and edit it so it reads better.  Add a "mea culpa" at the end.  I'm not gonna ask for an apoligy, 'cause I drop zeros all the time.

It's true tho, that you can't push very hard on something that is so rare.  But then I got confused.  You're not talking about "DM fusion", right?

Ai chihuahua.

http://samos.martech.fsu.edu/chapters/chapters/md.PDF
http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

If you grok those equations that I wouldn't touch with a ten foot pole then kudos, can't say more.
Then maybe you can say what 'a' and 'k' stand for in this apparently relevant paper (http://bh.knu.ac.kr/~jchan/paper/2009-PLB-Axion.pdf) :
Quote
Thus, again we can identify cs = k/(2ma) as an effective sound speed of the axion fluid.

My poor man citation will be from anonymous contributors on reddit forum (http://www.reddit.com/r/askscience/comments/1ouy4b/why_does_sound_move_so_slowly_in_a_boseeinstein/) (this is less classy than proper publications...) :
Quote from: TheAlgebrator
The speed of sound largely depends on the absolute temperature of the gas, and not so much due to the enhancement of quantum mechanical effects.
...
The question wasn't asking why it was 0.0022 m/s but why sound moves so slowly (compared to air). We are comparing a low, almost zero, energy medium to normal air. The elephant in the room is temperature. Air is around 300 Kelvin and a BEC has temperatures in the nano kelvin range. As mentioned in [1] paragraph 3, a good estimate for the speed of sound in an ideal gas as a function of temperature is speed=constant*sqrt(Absolute Temperature). Calculating the speed of sound in a BEC using this model I got an answer of the same magnitude as [2].

also

Quote
As far as explosions go, the atoms comprising a BEC are still very cold and even after a shockwave you would expect a relatively slow thermal expansion of the atoms. The way the atoms expansion would be similar to glass shattering into tiny pieces and expanding radially outward, but only very slowly.

I can imagine pushing too hard on DM and breaking the fragile aether into dark shards, in slow motion.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/09/2014 04:04 pm
GR doesn't have to be wrong in order for EEP to not fit every situation. Especially artificial situations. . .

. . .Prove me wrong.
I don't need to prove you wrong.  What you're saying is completely at odds with GR and history, as well as simple observations one can make on wiki. You are simply wrong.  All of GR depends upon weak equivalence, and in addition, Einstein's version or EEP, that holds equivalence is velocity and acceleration independent. All of GR requires that inertia and gravitational mass be the same under all conditions, or a preferred frame of reference will emerge.

I'm sorry but you're just wrong.  Look it up on Wiki.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 04:17 pm
GR doesn't have to be wrong in order for EEP to not fit every situation. Especially artificial situations. . .

. . .Prove me wrong.
I don't need to prove you wrong.  What you're saying is completely at odds with GR and history, as well as simple observations one can make on wiki. You are simply wrong.  All of GR depends upon weak equivalence, and in addition, Einstein's version or EEP, that holds equivalence is velocity and acceleration independent. All of GR requires that inertia and gravitational mass be the same under all conditions, or a preferred frame of reference will emerge.

I'm sorry but you're just wrong.  Look it up on Wiki.

Seriously, stop using wikipedia to make conclusions. My version of history is consistent. Read about Ernst Mach.

I'm going to use Wikipedia itself to shutdown your argument on my views of Machian Philosophy of science:

Mach is attributed with a number of principles that distill his ideal of physical theorisation — what is now called "Machian physics":

    1. It should be based entirely on directly observable phenomena (in line with his positivistic leanings)[12]
    2. It should completely eschew absolute space and time in favor of relative motion[13]
    3. Any phenomena that would seem attributable to absolute space and time (e.g. inertia, and centrifugal force) should instead be seen as emerging from the large scale distribution of matter in the universe.

IRT #1, Were the accelerations of objects in interstellar space "observable" to anyone in Mach's time?

The commonly held ideas of the unshakable equivalence of gravitational and inertial mass are based on a slippery slope of excluding directly observable phenomena.

Also Mach didn't accept Einstein. He didn't even accept the atom.

In the end Mach was MOSTLY right, but imprecise. That still holds us back today. Now we have to believe in dark matter and are out looking for that instead of questioning our own reasoning on the origins of inertial mass.

One of these days we'll wake up.

Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 04:23 pm
The important thing is what predictions are made by McCulloch's MiHsC deviation from EEP that differ from GR in such a way that the deviation can be checked agaisnt astrophysical data to nullify one or the other.  Have all the consequences from this deviation from EEP been mathematically explored  and checked against measurements?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 04:29 pm
WE are developing emdrive by asking these hard questions. You can't explain anomalous thrust using archaic reasoning. Now let's find that data! Or put mihsc to bed.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 04:33 pm
Of course, McCulloch's theory needs to satisfy, for example, these tests within the tests's precision:


Researcher   Year   Method   Result
Friedrich Wilhelm Bessel   1832   measure the period of pendulums of different mass but identical length   no measurable difference
Loránd Eötvös   1908   measure the torsion on a wire, suspending a balance beam, between two nearly identical masses under the acceleration of gravity and the rotation of the Earth   difference is less than 1 part in 109
Roll, Krotkov and Dicke   1964   Torsion balance experiment, dropping aluminum and gold test masses   |\eta(\mathrm{Al},\mathrm{Au})|=(1.3\pm1.0)\times10^{-11}[8]
David Scott   1971   Dropped a falcon feather and a hammer at the same time on the Moon   no detectable difference (not a rigorous experiment, but very dramatic being the first lunar one[9])
Braginsky and Panov   1971   Torsion balance, aluminum and platinum test masses, measuring acceleration towards the sun   difference is less than 1 part in 10^12
Eöt-Wash group   1987–   Torsion balance, measuring acceleration of different masses towards the earth, sun and galactic center, using several different kinds of masses   \eta(\text{Earth},\text{Be-Ti})=(0.3 \pm 1.8   )        \times 10^{-13}[10]
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/09/2014 04:38 pm
No one who believes Mach's Principle believes it based upon some authority, so chasing down Mach's other beliefs is just a distraction fallacy.  The point we're here concerned with is not even Mach.  It is Einstein.  So don't change the subject.  If you believe that inertial and gravitational mass are at any time different, then you believe a preferred reference frame will emerge and all of GR is completely WRONG.  This is why everyone who understands Einstein's theories holds that both the weak equivalence and Einstein's equivalence principle MUST be true.

Sorry, you you need to know this theory is contradictory to good ol' Uncle Al.  It is therefore suspect and for most of us, not to be taken seriously.  GR has a fantastical amount of observational support, and none of this has anything whatsoever to do with Mach refusing to believe in atoms.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 04:45 pm
@Ron
You realize that MET thrusters ALSO depend on mihsc being correct right? Also Mach informed Einstein. There is no distraction. Being obtuse doesn't give rise to progress either. Respectfully. Let's work together here.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 04:52 pm
Of course, McCulloch's theory needs to satisfy, for example, these tests within the tests's precision:


Researcher   Year   Method   Result
Friedrich Wilhelm Bessel   1832   measure the period of pendulums of different mass but identical length   no measurable difference
Loránd Eötvös   1908   measure the torsion on a wire, suspending a balance beam, between two nearly identical masses under the acceleration of gravity and the rotation of the Earth   difference is less than 1 part in 109
Roll, Krotkov and Dicke   1964   Torsion balance experiment, dropping aluminum and gold test masses   |\eta(\mathrm{Al},\mathrm{Au})|=(1.3\pm1.0)\times10^{-11}[8]
David Scott   1971   Dropped a falcon feather and a hammer at the same time on the Moon   no detectable difference (not a rigorous experiment, but very dramatic being the first lunar one[9])
Braginsky and Panov   1971   Torsion balance, aluminum and platinum test masses, measuring acceleration towards the sun   difference is less than 1 part in 10^12
Eöt-Wash group   1987–   Torsion balance, measuring acceleration of different masses towards the earth, sun and galactic center, using several different kinds of masses   \eta(\text{Earth},\text{Be-Ti})=(0.3 \pm 1.8   )        \times 10^{-13}[10]

Yeah but there is a distinction. Those above tests which are in fact correct in every way, are in a different domain. LOCAL They don't hold over interstellar domains. (dropping a hammer from the very edge of the galaxy, lasering a distant moon very very far away) Big difference. There is a horizon where the above tests fall apart, where Machian inertia no longer holds true as described.

MiHsC depends on the origin of inertia being Machian, but is derived differently.
There is a Machian limit out there.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 05:02 pm
GR doesn't have to be wrong in order for EEP to not fit every situation. Especially artificial situations.

"The rindler sphere is defined by the boundaries of the cavity *(horizon 1) and the approaching Rindler horizon (horizon 2)."

This new rindler sphere I just described denotes a new rindler sphere. A whole new variable.

There are 2 rindler spheres, well ellipses is more accurate. Squashed spheres then. They share an arc. The one as I drew and the one as I described. I need to add an arc to the drawing.

Thanks!

Edit:

Added pic with changes. Close enough.

It seems evident to me that MIHSC describes only the inertia component of emdrive which then enables Dr. White's ideas of thrust interactions.

Prove me wrong.
First of all thank you for going through the effort to put your ideas into pictorial form.  That is very commendable, as it much easier for people to write words.

Second, it appears to me that you favor physical (rather than mathematical) explanations.  I draw that conclusion from the notes about Casimir attraction, and for you searching for a physical interaction that will ultimately enable the movement.   I operate differently, I prefer John von Neumann's mathematical approach to physics.  One critical aspect of this approach are conservation laws.  I don't interpret the Casimir effect as an attractive force due to the quantum vacuum.  What I see in Prof. McCulloch's formulation is the assumption that a finite number of Unruh waves can fit in one or the other surfaces perpendicular to the 1 D direction of motion.  Again to me conservation of momentum is a critical law and given a change of inertia, that there must be a force (producing an acceleration) to conserve momentum is a satisfactory explanation.  The reason why this looks "unphysical" is because we are all accustomed to EEP: anything that deviates from EEP by its very nature feels unphysical.  Explaining the movement as enabling Dr. White's interactions with the Quantum Vacuum (modeled by him as a plasma) may be helpful to you but not to me, I just prefer McCulloch's explanation that it must be acted by a force to conserve momentum.  And as difficult as it maybe if forced to dispense with one or the other, I rather dispense with EEP than with conservation of momentum.  Of course, one still has to consider that the NASA, Chinese and Shawyer experiments still maybe an experimental artifact and they may not serve as a means of propulsion in outer space.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/09/2014 05:06 pm

If you grok those equations that I wouldn't touch with a ten foot pole then kudos, can't say more.
Then maybe you can say what 'a' and 'k' stand for in this apparently relevant paper (http://bh.knu.ac.kr/~jchan/paper/2009-PLB-Axion.pdf) :
Quote
Thus, again we can identify cs = k/(2ma) as an effective sound speed of the axion fluid.

Well, k is the wave number and a is a coefficient (where I would have just used 1/2 as in the simpleminded "perfect" superconducting cavity case)

Great ref by the by.  If I can grok it at all it says I should be able to write a 3 PD set of equations for the EM cavity and insert coefficients for a viscous term using the equation of state they give.  But, it still looks like the sound speed, etc., has to be experimentally determined from the axion mass.  (the 300m/s was the assumption to get a power figure as an example)

And NO, I'm not promising I CAN write those equations (and solve them with the boundary conditions), but I have been in that situation in the dim, very dark past.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 05:32 pm
GR doesn't have to be wrong in order for EEP to not fit every situation. Especially artificial situations.

"The rindler sphere is defined by the boundaries of the cavity *(horizon 1) and the approaching Rindler horizon (horizon 2)."

This new rindler sphere I just described denotes a new rindler sphere. A whole new variable.

There are 2 rindler spheres, well ellipses is more accurate. Squashed spheres then. They share an arc. The one as I drew and the one as I described. I need to add an arc to the drawing.

Thanks!

Edit:

Added pic with changes. Close enough.

It seems evident to me that MIHSC describes only the inertia component of emdrive which then enables Dr. White's ideas of thrust interactions.

Prove me wrong.
First of all thank you for going through the effort to put your ideas into pictorial form.  That is very commendable, as it much easier for people to write words.

Second, it appears to me that you favor physical (rather than mathematical) explanations.  I draw that conclusion from the notes about Casimir attraction, and for you searching for a physical interaction that will ultimately enable the movement.   I operate differently, I prefer John von Neumann's mathematical approach to physics.  One critical aspect of this approach are conservation laws.  I don't interpret the Casimir effect as an attractive force due to the quantum vacuum.  What I see in Prof. McCulloch's formulation is the assumption that a finite number of Unruh waves can fit in one or the other surfaces perpendicular to the 1 D direction of motion.  Again to me conservation of momentum is a critical law and given a change of inertia, that there must be a force (producing an acceleration) to conserve momentum is a satisfactory explanation.  The reason why this looks "unphysical" is because we are all accustomed to EEP: anything that deviates from EEP by its very nature feels unphysical.  Explaining the movement as enabling Dr. White's interactions with the Quantum Vacuum (modeled by him as a plasma) may be helpful to you but not to me, I just prefer McCulloch's explanation that it must be acted by a force to conserve momentum.  And as difficult as it maybe if forced to dispense with one or the other, I rather dispense with EEP than with conservation of momentum.  Of course, one still has to consider that the NASA, Chinese and Shawyer experiments still maybe an experimental artifact and they may not serve as a means of propulsion in outer space.

I couldn't agree more. I deal in the physical world of electronics in my daily life. Engineering, some math. You are a math guy. I hope we're both right in the end because we compliment eachother.

On the notion of MiHsC violating GR by virtue of violating the EEP.....
Did anyone notice a few pages back, where I took Dr.  McCulloch's ideas on dark matter and the inertia of particles with very very low accelerations, and wrapped that right back into General Relativity by further defining the origin of inertia as a function of time? The higher up a gravity well you are, the faster time flows. Look it up. A particle would have less inertia (resistance to acceleration if you want to call it that) over time, if it's time was running faster compared to others on very large scales. Large magnitudes of time differential effect acceleration and inertia as a consequence of spacetime. Accelerations affect inertia. Why is it such a stretch to understand there is an energy difference of potential between two clocks running different rates? Get it? Time runs slower down low. Time runs faster up high. What is low or high on a cosmic scale? MiHsC doesn't violate Relativity, it confined EEP to a different, more precise domain. The essence of Inertia is time.

Anyone wanna put math to that? Any math guys out there?


Title: Re: EM Drive Developments
Post by: aero on 10/09/2014 05:36 pm
So if the inertia varies within the cavity then what is to prevent a Dean drive from working like depicted in the attached sketch? Apart from interference effects.

In words, the mass rotates around a central support with high inertia at the bottom and low inertia at the top pulling the whole attached cavity downward by centrifugal force. Of course a spinning flywheel would work just as well, better in fact, but the blob of mass is easier to visualize.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 05:48 pm
So if the inertia varies within the cavity then what is to prevent a Dean drive from working like depicted in the attached sketch? Apart from interference effects.

In words, the mass rotates around a central support with high inertia at the bottom and low inertia at the top pulling the whole attached cavity downward by centrifugal force. Of course a spinning flywheel would work just as well, better in fact, but the blob of mass is easier to visualize.
McCulloch is dealing with the inertia of the electrons (in the walls) and the photons within the cavity.  His simple formula is a 1 dimensional approximation along the (proposed unidirectional) direction of motion (of the drive's center of mass), with the small and large flat surfaces perpendicular to the direction of motion.  The proposed 1-D direction of motion is along the cone's central axis, which is an axis of symmetry.

To posit a rotation as envisioned in the diagram one needs at least a multidimensional analysis and propose a reason why the photons in the cavity and the electrons in the copper walls would be executing an overall rotational motion.  In general (refer to the wave modes in the cavity, at 2 GHz the modes shapes are not executing such overall rotation but there are rotational cells of smaller scale).  If I am not mistaken the rotational cells are such that they are clockwise and counterclockwise like eddies in a fluid, to satisfy the same direction of motion at their common boundary.  As such their rotations seem to be self-cancelling.

This is a good question.  The modes have to be examined.  The Electric Field is completely confined within the cavity that acts as a Faraday cage. 
Title: Re: EM Drive Developments
Post by: aero on 10/09/2014 06:01 pm
So if the inertia varies within the cavity then what is to prevent a Dean drive from working like depicted in the attached sketch? Apart from interference effects.

In words, the mass rotates around a central support with high inertia at the bottom and low inertia at the top pulling the whole attached cavity downward by centrifugal force. Of course a spinning flywheel would work just as well, better in fact, but the blob of mass is easier to visualize.
McCulloch is dealing with the inertia of the electrons (in the walls) and the photons within the cavity.  His simple formula is a 1 dimensional approximation along the (proposed unidirectional) direction of motion (of the drive's center of mass), with the small and large flat surfaces perpendicular to the direction of motion. 

To posit a rotation as envisioned in the diagram one needs at least a 2-D analysis and propose a reason why the photons in the cavity and the electrons in the copper walls would be executing an overall rotational motion.  In general (refer to the wave modes in the cavity, at 2 GHz the modes shapes are not executing such overall rotation but there are rotational cells of smaller scale).  If I am not mistaken the rotational cells are such that they are clockwise and counterclockwise like eddies in a fluid, to satisfy the same direction of motion at their common boundary.  As such their rotations seem to be self-cancelling.

Sorry, I really wasn't addressing the EM drive at all, just the variable inertia. My rotating flywheel (or ball) is a complete mechanism in itself. It just operates within the cavity where inertia varies top to bottom.

My point being that this variable inertia is certainly counter intuitive and provides a fast track to a whole raft of new inventions.

Proof of concept anyone?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 06:06 pm
So if the inertia varies within the cavity then what is to prevent a Dean drive from working like depicted in the attached sketch? Apart from interference effects.

In words, the mass rotates around a central support with high inertia at the bottom and low inertia at the top pulling the whole attached cavity downward by centrifugal force. Of course a spinning flywheel would work just as well, better in fact, but the blob of mass is easier to visualize.

I think that wouldn't move it would oscillate on the table. By virtue of the string, conservation of angular momentum. At least emdrive heats the cavity unevenly by virtue of its uneven particle momentums.
Title: Re: EM Drive Developments
Post by: MikeMcCulloch on 10/09/2014 06:08 pm
Someone has raised the issue that MiHsC violates EEP and weakly tries to argue against MiHsC by saying I'm an oceanographer and claims MiHsC hasn't seen peer review? Well, I am a physicist (degree in physics, PhD in physical oceanography) and I've published 10 peer-reviewed papers on MiHsC, some in very good physics journals (MNRAS, EPL). Besides, personal histories have no bearing on whether or not a theory is true or not, only experiment decides. It is true that EEP has been tested in a torsion balance, but MiHsC violates EEP in such a way that it cannot be detected by a torsion balance experiment (or Galileo's ball expt either). You can see this by deriving the eqn of motion. In my opinion there is too much reverence for old theories, over new data (including Emdrive, real or not). I'm arguing that GR breaks down at extremely low accelerations. You may say 'We can fix GR in deep space with dark matter and energy' but this is ugly and cannot work for tiny globular clusters which also show a rotation anomaly (Scarpa et al., 2006) since dark matter, to work, has to stay spread out on bigger galactic scales.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 06:11 pm
Quoting Ron. "So once more back to basics: in order for no preferred frame of reference to emerge, one has to hold that inertial and gravitational mass are always identical. . under ALL conditions and circumstances.  This is what MiHsC denies.  And I am just noting to you, this "theory" that challenges Einstein, comes from someone with no training in field theory--as is the norm."

I've thought very long and hard ::) on this (preferred frames of reference). I made note of the fact that our universe is undergoing accelerating expansion, while at the same time the QV remains consistent. The preferred frame is virtual. Those virtual particles that nobody believes in that yoink in and out of existence with plank time, have no preferred frame of reference other than the horizon of the universe, and no preferred path in any particular direction.

Why does everyone neglect the fact that the universe itself is a frame of reference?
They are inertial. So how can I react with them and produce thrust? That is what I want to know.

(Side thought) Dr. White really shot himself in the foot when he put the word "plasma" in QVPT. That turned physics against him. QVT would suffice.

I have to say, that given new data, like anomalous thrust predictions, I have to force myself to think differently. I have to have the courage to "loooook harder." I have to accept the risk of coming up with borderline crackpot sounding ideas that make me look bad. But that is what is required to explain new info like the emdrive. I trust the experimentalist in that they at least got the measurements right. There is a VERY high likelyhood that because of thinking differently, errors were made and that is fine. Because from those errors come new insight and finally a path to the real truth....and finally a trip to the stars......or a hovercar. Thanks!
Title: Re: EM Drive Developments
Post by: Chris Bergin on 10/09/2014 06:26 pm
1) I will not allow this forum to be used to attack people who are not here to defend themselves, or other members. Reported post removed. If I've missed any others, or any where someone has quoted the ad hominem, please report it.

2) I'm not entirely convinced we even need this Advanced Topics area, so threads in here are on thin ground, because it's not what I set the site up for.

Taking both into account, you all need to be very, very careful with these threads, because my patience is thin with areas we'll never get to cover on the news site.
Title: Re: EM Drive Developments
Post by: aero on 10/09/2014 06:27 pm
So if the inertia varies within the cavity then what is to prevent a Dean drive from working like depicted in the attached sketch? Apart from interference effects.

In words, the mass rotates around a central support with high inertia at the bottom and low inertia at the top pulling the whole attached cavity downward by centrifugal force. Of course a spinning flywheel would work just as well, better in fact, but the blob of mass is easier to visualize.

I think that wouldn't move it would oscillate on the table. By virtue of the string, conservation of angular momentum. At least emdrive heats the cavity unevenly by virtue of its uneven particle momentums.

That is the way it would work without the variable inertia.

Fc = (inertial mass)*w^2/r.

If inertial mass varies with all else fixed, then force varies.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 06:32 pm
So if the inertia varies within the cavity then what is to prevent a Dean drive from working like depicted in the attached sketch? Apart from interference effects.

In words, the mass rotates around a central support with high inertia at the bottom and low inertia at the top pulling the whole attached cavity downward by centrifugal force. Of course a spinning flywheel would work just as well, better in fact, but the blob of mass is easier to visualize.

I think that wouldn't move it would oscillate on the table. By virtue of the string, conservation of angular momentum. At least emdrive heats the cavity unevenly by virtue of its uneven particle momentums.

That is the way it would work without the variable inertia.

Fc = (inertial mass)*w^2/r.

If inertial mass varies with all else fixed, then force varies.

Okay I hear you and you are right. Under modified inertia, you still have to react with something......just like emdrive has to react with something. That realization is what put me back on the QV wagon. Dr. Rodal might have a better answer for you. We're in different camps now about reacting against something. I maintain that because inertia was modified, not lowered, it isn't just going to shoot through space in a useful way. Due to the perceived very small anisotropy of the universe, it might move for you a little bit if you wait a really long time.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/09/2014 06:32 pm
I have to accept the risk of coming up with borderline crackpot sounding ideas that make me look bad. But that is what is required to explain new info like the emdrive.

I can appreciate this.  Let me note one past experience.

I'm a philosopher of science and technology, not a technician.  I've studied both phil of sci and phil of tech, and it is really the former as well as my study of epistemology that suits me to look for "emergent" technology.  About a decade ago, I was hired by the Advanced Aerospace Research Center because of my odd training, to hunt for emergent technologies they might like to invest in.  My decision then, as now, was and is that to best vet the crazy models, theories and claims, I use a two-fold criteria and it is pretty much the criteria of what makes good science.

First is, I want to see cogent theory.  Since I'm not a physicist, I rely on peer review.  This is actually a benefit because to be honest, the time it takes to really understand a new model is why most people never invest themselves.  It is just too labor intensive.  The best people to judge truly cutting edge and advanced models are those who specialize in those fields.  And you want that judgement to be one people will stand by, hence the need for peer review.  Although you and I can make judgements about this or that model, the best judgements come form those who are specialists in the field. 

Second, I want to see empirical evidence.  If someone is gonna spend money, there should be real evidence.  One can then quibble about what is intellectually satisfying.  I want to see vacuum since there are so many spurious effects that are ruled out by vacuum.  But the point is, there should be real observation to back up any proposed model, before anyone takes it much too seriously.

And just saying, this model from an Oceanographer doesn't meet either of these criteria.  Given it contradicts Einstein and what we have good reason to suppose is true (EEP and GR), I can't say I think this is going to be a fruitful line of inquiry.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 06:39 pm
I have to accept the risk of coming up with borderline crackpot sounding ideas that make me look bad. But that is what is required to explain new info like the emdrive.
Quote
Quoting @Ron
" Given it contradicts Einstein and what we have good reason to suppose is true (EEP and GR), I can't say I think this is going to be a fruitful line of inquiry."

I like Einstein too, he's never let me down so far. But a theory that satisfies infinity, required infinite insight.

Edit:
Things got a little heated here. I want us to play nice and be respectful. In the end, we're all interesting in furthering mankind. This thread is devoted to news and insight related to EMdrive, not attacking opposing (and possibly complimentary) ideas. So on.......

Question:
Can anyone provide any insight to how the dielectric material in the device (seems to) function like a quantum rocket nozzle? I posted some stuff earlier about momentum transfer to virtual particles for clarity. It mentioned chirality, which is what I've been going on about for days now.

The dielectric seems as important to the emdrive, as a nozzle is to a chemical rocket.

http://arxiv-web3.library.cornell.edu/abs/1404.5990

Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 07:21 pm
Question:
Can anyone provide any insight to how the dielectric material in the device (seems to) function like a quantum rocket nozzle? I posted some stuff earlier about momentum transfer to virtual particles for clarity. It mentioned chirality, which is what I've been going on about for days now.

The dielectric seems as important to the emdrive, as a nozzle is to a chemical rocket.

http://arxiv-web3.library.cornell.edu/abs/1404.5990

We have discussed the dielectric resonator a lot in this thread.  A lot of the discussion was prompted by this sentence in the NASA "Anomalous Thrust..." report:

<<There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber. The geometry, location, and material properties of this resonator must be evaluated using numerous COMSOL® iterations to arrive at a viable thruster solution. We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust.>>

We know:

1) Another test increased the power input by a factor of 6 [both tests with a dielectric resonator] and the thrust force instead of increasing, it decreased by 10%

2) Someone reported in this thread that Shawyer no longer uses a dielectric resonator for his microwave cavity

3) the Chinese experiments did not report anything concerning the dielectric resonator

4) Someone else posted that his/her information is that Paul March introduced a Teflon dielectric resonator as an exploratory move to see its effect.

5) The COMSOL analysis both for the Canae and the truncated cone show the Electric Field to be an order of magnitude higher in the dielectric material than in the cavity.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 07:48 pm
Well the reason why I've been going on about this is that, as I've mentioned, the QED vacuum is diamagnetic. A refresher about diamagnetism is that diamagnetic materials create an induced magnetic field in a direction opposite to an externally applied magnetic field. This knowledge, combined with the ideas in the paper above, excite me.

Assuming a properly oriented PTFE slug in the presence of an rf field who's poynting vector is in the direction of magnetic energy flow (not electrical), combined with knowing the QED vacuum is diamagnetic; I see thrust.

Hasty generalization? Faulty reasoning? Or a lead?

http://books.google.it/books?id=n51yJr4b_oQC&pg=PA26&redir_esc=y#v=onepage&q&f=false

A very small thrust, in the presence of modified inertia+continuous acceleration=Bingo?
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 08:53 pm
Well the reason why I've been going on about this is that, as I've mentioned, the QED vacuum is diamagnetic. A refresher about diamagnetism is that diamagnetic materials create an induced magnetic field in a direction opposite to an externally applied magnetic field. This knowledge, combined with the ideas in the paper above, excite me.

Assuming a properly oriented PTFE slug in the presence of an rf field who's poynting vector is in the direction of magnetic energy flow (not electrical), combined with knowing the QED vacuum is diamagnetic; I see thrust.

Hasty generalization? Faulty reasoning? Or a lead?

http://books.google.it/books?id=n51yJr4b_oQC&pg=PA26&redir_esc=y#v=onepage&q&f=false

A very small thrust, in the presence of modified inertia+continuous acceleration=Bingo?

Well, water is weakly diamagnetic too.  Let's say one immerses a (EM drive with a PTFE slug) submarine inside the water.  Would you expect directional propulsion of the submarine from the diamagnetism of the water surrounding it?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 09:02 pm
Well the reason why I've been going on about this is that, as I've mentioned, the QED vacuum is diamagnetic. A refresher about diamagnetism is that diamagnetic materials create an induced magnetic field in a direction opposite to an externally applied magnetic field. This knowledge, combined with the ideas in the paper above, excite me.

Assuming a properly oriented PTFE slug in the presence of an rf field who's poynting vector is in the direction of magnetic energy flow (not electrical), combined with knowing the QED vacuum is diamagnetic; I see thrust.

Hasty generalization? Faulty reasoning? Or a lead?

http://books.google.it/books?id=n51yJr4b_oQC&pg=PA26&redir_esc=y#v=onepage&q&f=false

A very small thrust, in the presence of modified inertia+continuous acceleration=Bingo?

Well, water is weakly diamagnetic too.  Let's say one immerses a (EM drive with a PTFE slug) submarine inside the water.  Would you expect directional propulsion of the submarine from the diamagnetism of the water surrounding it?

I don't think the medium you are in makes any difference. Water is of no fundamental difference to air (they're both fluids) in the context of this, which is the QV of our universe. The QV is the fundamental thing here.

Congratulations, you just invented a propless sub.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 09:03 pm
Well the reason why I've been going on about this is that, as I've mentioned, the QED vacuum is diamagnetic. A refresher about diamagnetism is that diamagnetic materials create an induced magnetic field in a direction opposite to an externally applied magnetic field. This knowledge, combined with the ideas in the paper above, excite me.

Assuming a properly oriented PTFE slug in the presence of an rf field who's poynting vector is in the direction of magnetic energy flow (not electrical), combined with knowing the QED vacuum is diamagnetic; I see thrust.

Hasty generalization? Faulty reasoning? Or a lead?

http://books.google.it/books?id=n51yJr4b_oQC&pg=PA26&redir_esc=y#v=onepage&q&f=false

A very small thrust, in the presence of modified inertia+continuous acceleration=Bingo?

Well, water is weakly diamagnetic too.  Let's say one immerses a (EM drive with a PTFE slug) submarine inside the water.  Would you expect directional propulsion of the submarine from the diamagnetism of the water surrounding it?

What I would expect is a hydrophobic effect: the water will be repelled away from the magnetic surfaces

https://www.youtube.com/watch?v=SoE-udZzcfA

https://www.youtube.com/watch?v=jyqOTJOJSoU
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 09:06 pm
Well the reason why I've been going on about this is that, as I've mentioned, the QED vacuum is diamagnetic. A refresher about diamagnetism is that diamagnetic materials create an induced magnetic field in a direction opposite to an externally applied magnetic field. This knowledge, combined with the ideas in the paper above, excite me.

Assuming a properly oriented PTFE slug in the presence of an rf field who's poynting vector is in the direction of magnetic energy flow (not electrical), combined with knowing the QED vacuum is diamagnetic; I see thrust.

Hasty generalization? Faulty reasoning? Or a lead?

http://books.google.it/books?id=n51yJr4b_oQC&pg=PA26&redir_esc=y#v=onepage&q&f=false

A very small thrust, in the presence of modified inertia+continuous acceleration=Bingo?

Well, water is weakly diamagnetic too.  Let's say one immerses a (EM drive with a PTFE slug) submarine inside the water.  Would you expect directional propulsion of the submarine from the diamagnetism of the water surrounding it?

What I would expect is a hydrophobic effect: the water will be repelled away from the magnetic surfaces

https://www.youtube.com/watch?v=SoE-udZzcfA

Yeah if water was inside your emdrive. You can bend water at home with the static charge on a comb.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 09:08 pm
Since you're thrusting against the QV, you could stand right next to the thing while it is on full bore and you wouldn't feel anything hitting you. Considering the test pulses lasted for about 30 seconds or so, how long would it take for the thing to rip right off the table under constant acceleration?

Also I need to go back to the paper and see if TE modes were thrusting flatly over the period rf was on or were they at an upward angle. Were TM modes flat? Was there a difference? That can give a lot of info. It could reveal the orientation of the dielectric in the unit. My hard copy is at home so I gotta find it in my sea of bookmarks.
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/09/2014 09:15 pm
For the sake of personal clarification, what is the expected impact of increasing or decreasing the tapering of the resonance cavity frustum?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 09:19 pm
Given the information provided, can anyone provide a calculation and proof showing a vector where momentum is transferred from a particle/wave inside the cavity, through to the QED vacuum particles/waves? Resulting in a reaction force of the device. If so, what is the impulse?

Seems like a tall order indeed.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 09:22 pm
For the sake of personal clarification, what is the expected impact of increasing or decreasing the tapering of the resonance cavity frustum?

Increasing the difference in surface area between the two flat surfaces of the truncated cone should increase the thrust as long as the truncated cone is not too far from being a cylinder since the simple formula by Prof. McCulloch is 1-dimensional.  In the limit for a pointy cone one gets an infinite thrust force, which does not make sense.  A detailed analysis is lacking.  Since the shape of the surfaces in the Casimir effect is difficult to analyze, I expect the same in this problem.  I have posed that question to Prof. McCulloch in his blog: see here http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/09/2014 09:28 pm

If you grok those equations that I wouldn't touch with a ten foot pole then kudos, can't say more.
Then maybe you can say what 'a' and 'k' stand for in this apparently relevant paper (http://bh.knu.ac.kr/~jchan/paper/2009-PLB-Axion.pdf) :
Quote
Thus, again we can identify cs = k/(2ma) as an effective sound speed of the axion fluid.

Well, k is the wave number and a is a coefficient (where I would have just used 1/2 as in the simpleminded "perfect" superconducting cavity case)

Great ref by the by.  If I can grok it at all it says I should be able to write a 3 PD set of equations for the EM cavity and insert coefficients for a viscous term using the equation of state they give.  But, it still looks like the sound speed, etc., has to be experimentally determined from the axion mass.  (the 300m/s was the assumption to get a power figure as an example)

And NO, I'm not promising I CAN write those equations (and solve them with the boundary conditions), but I have been in that situation in the dim, very dark past.

Well, that kept me awake during my nap.  Anyway I think the coefficient a has to be an absorption, but I can't read his references because I don't have anything but public info these days.

Every time I try to visualize a physical model I add another differential wave equation. But it has to be something like the EM cavity solutions immersed in a fluid (dilute gas) w/ very porous walls.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 09:46 pm
Assuming the shaded area is the dielectric, it really needs to be at the other end or strategically placed in areas of max H along the length. This is becoming clearer now. I hope the math works and the theories hold.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 09:51 pm
The dielectric is clearly visible as a small flat douhgnut (a disk with a central hole) in these pictures of the Electric Field for their future truncated cone.  The NASA researchers think that it is best located at the small flat surface.
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/09/2014 09:59 pm
The dielectric is clearly visible as a small flat douhgnut (a disk with a central hole) in these pictures of the Electric Field for their future truncated cone.  The NASA researchers think that it is best located at the small flat surface.

All the more reason to try to break it and see if it breaks as anticipated. :)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 10:00 pm
The dielectric is clearly visible as a small flat douhgnut (a disk with a central hole) in these pictures of the Electric Field for their future truncated cone.  The NASA researchers think that it is best located at the small flat surface.

Given what we (think) we know now. That is the worst place to put it. I'm drawing a pic now. Using this guy's info as a ref in transverse E and the right hand rule.

http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html


Edit:

I don't even need to draw it. Just scroll down where you see the three TE modes. Place imaginary dielectric in the right places (max H) and with the right orientation. Then cross fingers.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 10:02 pm
The magnetic field in the truncated cone is in blue  Observe that the magnetic field is directed along the axis of revolution of the truncated cone, while the electric field is in red and it circulates along two main cells of different rotational sign, clockwise and counterclockwise:
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 10:06 pm
The magnetic field in the truncated cone is in blue  Observe that the magnetic field is directed along the axis of revolution of the truncated cone, while the electric field is in red and it circulates along two main cells of different rotational sign, clockwise and counterclockwise:

Yep you got it. There's your differences in angular and linear momentum too.


Given the placement of the dielectric between Cannae and Shawyer, Cannae got it more correct. Guess that's why they are pretty close. Shawyer had a better shape, Cannae had a better dielectric setup.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 10:11 pm
The magnetic field in the truncated cone is in blue  Observe that the magnetic field is directed along the axis of revolution of the truncated cone, while the electric field is in red and it circulates along two main cells of different rotational sign, clockwise and counterclockwise:

Yep you got it. There's your differences in angular and linear momentum too.

Observe that the magnetic field arrows point away from both surfaces, towards the middle of the truncated cone, but it is stronger emanating from the larger surface, so the neutral point is closer towards the small surface
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 10:14 pm
The magnetic field in the truncated cone is in blue  Observe that the magnetic field is directed along the axis of revolution of the truncated cone, while the electric field is in red and it circulates along two main cells of different rotational sign, clockwise and counterclockwise:

Yep you got it. There's your differences in angular and linear momentum too.

Observe that the magnetic field arrows point away from both surfaces, towards the center of the truncated cone.

They are counter rotation circles in the vertical axis, meeting in the center. The magnetic flux flows like water down a drain, because the whole rf field has a rotation, and the direction of the poynting vector.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 10:27 pm
The magnetic field in the truncated cone is in blue  Observe that the magnetic field is directed along the axis of revolution of the truncated cone, while the electric field is in red and it circulates along two main cells of different rotational sign, clockwise and counterclockwise:

Yep you got it. There's your differences in angular and linear momentum too.

Observe that the magnetic field arrows point away from both surfaces, towards the center of the truncated cone.

They are counter rotation circles in the vertical axis, meeting in the center. The magnetic flux flows like water down a drain, because the whole rf field has a rotation.

but it is stronger emanating from the larger surface, so the neutral point is closer towards the small surface
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 10:41 pm
Areas of max H flow in poynting vector. Wonder which one would be best?

A separate issue just realized is if this resolves the Q discrepancy on page 18 for the TM mode, the dielectric was probably in a magnetic null zone.

Sure hope that arxiv paper http://arxiv-web3.library.cornell.edu/abs/1404.5990 on momentum is correct and applicable.

I still haven't gotten around to looking at how chiral PTFE is along x, y, z axis.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 10:42 pm
Diamagnetism calculations
MIT Course 6.763 2003 Lecture 8

http://web.mit.edu/6.763/www/FT03/Lectures/Lecture8.pdf
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 11:27 pm
This is important:
Please fact check me on this but of the three TM modes on this http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html page; the one closest resembling TM211 would be this one right? At least good enough for a rough model? I think so. Not exactly but close enough because what I'm really interested in are the position of transverse H with respect to Z. The view is of the Z axis running vertically so the blue magnetic X, and Y are just dots and crosses.

I can see how highly frequency dependent and sensitive this mode is, which accounts for the big difference in Q and thrust with just a small change in frequency. Given the small size of the dielectric slug in the vertical axis at the small end, the resonant mode would very easily dip into and out of the dielectric with very small freq changes. Hence the loss of thrust. A COMSOL plot is needed for 1932.6 and 1936.7 to see this. I need to see if the magnetic field lines were in the dielectric more or less with both freqs.

At 1932.6, Q was down but thrust was up. Very telling indeed.

If I'm right, then eureka!
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 11:43 pm
This is important:
Please fact check me on this but of the three TM modes on this http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html page; the one closest resembling TM211 would be this one right? At least good enough for a rough model? I think so. Not exactly but close enough because what I'm really interested in are the position of transverse H with respect to Z. The view is of the Z axis running vertically so the blue magnetic X, and Y are just dots and crosses.

I can see how highly frequency dependent and sensitive this mode is, which accounts for the big difference in Q and thrust with just a small change in frequency. Given the small size of the dielectric slug in the vertical axis at the small end, the resonant mode would very easily dip into and out of the dielectric with very small freq changes. Hence the loss of thrust. A COSMOL plot is needed for 1932.6 and 1936.7 to see this. I need to see if the magnetic field lines were in the dielectric more or less with both freqs.

At 1932.6, Q was down but thrust was up. Very telling indeed.

If I'm right, then eureka!

Answer: none of the modes calculated in the closed-form solution by Greg Egan here: http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=611555;image)

agree with the modes calculated by COMSOL Finite Element analysis as presented by Brady et.al. (shown with red arrows in the attachment below).

The first Transverse Electric mode shown by Egan has a single cell along the cone's axis of revolution.
The mode calculated by COMSOL Brady et.al. has two cells along the cone's axis of revolution.

The second Transverse Electric mode shown by Egan has two cells, but they are distributed in a completely different fashion: the smaller cell is closest to the large transverse surface while the mode calculated by COMSOL shows the smaller cell closest to the smaller transverse surface.

It is not clear why this is so.  It could be because of the boundary conditions.  I have a strong suspicion that the reason is due to the cylinder inside the truncated cone shown in pink red here: (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=611263;image)

When I have time I may model it with Mathematica and see what's going on but I don't have free time to do that during the next couple of weeks.

 
Title: Re: EM Drive Developments
Post by: DIYFAN on 10/09/2014 11:50 pm
This is important:
Please fact check me on this but of the three TM modes on this http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html page; the one closest resembling TM211 would be this one right? At least good enough for a rough model? I think so. Not exactly but close enough because what I'm really interested in are the position of transverse H with respect to Z. The view is of the Z axis running vertically so the blue magnetic X, and Y are just dots and crosses.

Without speaking specifically to your observation, the shape matches fairly closely the cavity in Shawyer's most recent patent disclosure (with parabolic ends):
http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=20130206&CC=GB&NR=2493361A&KC=A
Title: Re: EM Drive Developments
Post by: Mulletron on 10/09/2014 11:51 pm
Yeah Egan's modes are being used as generic representations. I only care about the last number here. TM211, TMXYZ. I only care about Z because X and Y follow Z. Do you see how increasing and decreasing the frequency fills the void of the cavity more or less? That's what I'm getting at. The cells get smaller with higher frequency and change shape. At a critical point when increasing frequency, you get a brand new mode by adding a cell. This is pretty intuitive. Mostly because I know radars really well. You can't see it exactly without a plot.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/09/2014 11:55 pm
This is important:
Please fact check me on this but of the three TM modes on this http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html page; the one closest resembling TM211 would be this one right? At least good enough for a rough model? I think so. Not exactly but close enough because what I'm really interested in are the position of transverse H with respect to Z. The view is of the Z axis running vertically so the blue magnetic X, and Y are just dots and crosses.

I can see how highly frequency dependent and sensitive this mode is, which accounts for the big difference in Q and thrust with just a small change in frequency. Given the small size of the dielectric slug in the vertical axis at the small end, the resonant mode would very easily dip into and out of the dielectric with very small freq changes. Hence the loss of thrust. A COSMOL plot is needed for 1932.6 and 1936.7 to see this. I need to see if the magnetic field lines were in the dielectric more or less with both freqs.

At 1932.6, Q was down but thrust was up. Very telling indeed.

If I'm right, then eureka!

Answer: none of the modes calculated in the closed-form solution by Greg Egan here: http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=611555;image)

agree with the modes calculated by COMSOL Finite Element analysis as presented by Brady et.al. (shown with red arrows in the attachment below).

The first Transverse Electric mode shown by Egan has a single cell along the cone's axis of revolution.
The mode calculated by COMSOL Brady et.al. has two cells along the cone's axis of revolution.

The second Transverse Electric mode shown by Egan has two cells, but they are distributed in a completely different fashion: the smaller cell is closest to the large transverse surface while the mode calculated by COMSOL shows the smaller cell closest to the smaller transverse surface.

It is not clear why this is so.  It could be because of the boundary conditions.  I have a strong suspicion that the reason is due to the cylinder inside the truncated cone shown in pink red here: (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=611263;image)

When I have time I may model it with Mathematica and see what's going on but I don't have free time to do that during the next couple of weeks.

 

If the small end is filled w/ dielectric that would make the difference, the optical length is greater for the same physical length.  Teflon n ~ 2
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 11:55 pm
Yeah Egan's modes are being used as generic representations. I only care about the last number here. Do you see how increasing and decreasing the frequency fills the void of the cavity more or less? That's what I'm getting at. The cells get smaller with higher frequency and change shape. You can't see it exactly without a plot.
Sorry, to me they are completely different mode shapes, as I wrote above.  Again, I think that the Egan solution is inapplicable mainly because of the pink-red cylinder inside the truncated cone and to a much lesser extent because of the flat surfaces.
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 11:57 pm
This is important:
Please fact check me on this but of the three TM modes on this http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html page; the one closest resembling TM211 would be this one right? At least good enough for a rough model? I think so. Not exactly but close enough because what I'm really interested in are the position of transverse H with respect to Z. The view is of the Z axis running vertically so the blue magnetic X, and Y are just dots and crosses.

I can see how highly frequency dependent and sensitive this mode is, which accounts for the big difference in Q and thrust with just a small change in frequency. Given the small size of the dielectric slug in the vertical axis at the small end, the resonant mode would very easily dip into and out of the dielectric with very small freq changes. Hence the loss of thrust. A COSMOL plot is needed for 1932.6 and 1936.7 to see this. I need to see if the magnetic field lines were in the dielectric more or less with both freqs.

At 1932.6, Q was down but thrust was up. Very telling indeed.

If I'm right, then eureka!

Answer: none of the modes calculated in the closed-form solution by Greg Egan here: http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=611555;image)

agree with the modes calculated by COMSOL Finite Element analysis as presented by Brady et.al. (shown with red arrows in the attachment below).

The first Transverse Electric mode shown by Egan has a single cell along the cone's axis of revolution.
The mode calculated by COMSOL Brady et.al. has two cells along the cone's axis of revolution.

The second Transverse Electric mode shown by Egan has two cells, but they are distributed in a completely different fashion: the smaller cell is closest to the large transverse surface while the mode calculated by COMSOL shows the smaller cell closest to the smaller transverse surface.

It is not clear why this is so.  It could be because of the boundary conditions.  I have a strong suspicion that the reason is due to the cylinder inside the truncated cone shown in pink red here: (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=611263;image)

When I have time I may model it with Mathematica and see what's going on but I don't have free time to do that during the next couple of weeks.

 

If the smll end is filled w/ dielectric that would make the difference, the optical length is greater for the same physical length

No, I don't think that it is the dielectric.  The mode shapes are due to the geometrical boundary conditions, and the boundary condition inside is of a cylinder 
Title: Re: EM Drive Developments
Post by: Rodal on 10/09/2014 11:58 pm
It is incorrect to think that it is a truncated cone on the inside.  Everything shows that it is a cylinder on one end joined to a truncated cone on the other end.  The mode shapes for such a geometric body are different than the mode shapes for a truncated cone as modeled by Egan.

And I don't think that the cylinder is there by accident. Somebody thought this through.
Title: Re: EM Drive Developments
Post by: aero on 10/10/2014 12:00 am
I made up an illustration showing the general character of dark matter thrust resulting from the varying inertia within the cavity. I need to have some data before putting numbers to the thrust, maybe someone else is curious enough to do that. I'm happy that the thrust points in the right direction. See the text on my drawing for my explanation.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 12:04 am
It is incorrect to think that it is a truncated cone on the inside.  Everything shows that it is a cylinder on one end joined to a truncated cone on the other end.  The mode shapes for such a geometric body are different than the mode shapes for a truncated cone as modeled by Egan.

And I don't think that the cylinder is there by accident. Somebody thought this through.


Yeah it looks like they put a can inside the cone for some reason. Good eye. Still I wanna see those modes.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 12:09 am
It looks like what is known as an injector/cone nozzle.  The cylinder section is the injector part, and the rest is the conical part of the nozzle.  Except that in an injector/cone, the injector is significantly shorter length in comparison with the cone length, and at the joint the cone diameter matches the injector diameter and here they do not.

Like you said, rather than having a can and a truncated cone joined, it looks like they put a can inside the truncated cone.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 12:17 am
Does anybody know whether this NASA truncated cone with a cylindrical can inside it, on the small end, was an early design by Shawyer?
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 12:20 am
I made up an illustration showing the general character of dark matter thrust resulting from the varying inertia within the cavity. I need to have some data before putting numbers to the thrust, maybe someone else is curious enough to do that. I'm happy that the thrust points in the right direction. See the text on my drawing for my explanation.
The question is, physically, what is responsible for the change in inertial mass of the particle in the picture ?
Title: Re: EM Drive Developments
Post by: aero on 10/10/2014 12:25 am
I made up an illustration showing the general character of dark matter thrust resulting from the varying inertia within the cavity. I need to have some data before putting numbers to the thrust, maybe someone else is curious enough to do that. I'm happy that the thrust points in the right direction. See the text on my drawing for my explanation.
The question is, physically, what is responsible for the change in inertial mass of the particle in the picture ?

I thought Prof. M had already figured that out?
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 12:27 am
I made up an illustration showing the general character of dark matter thrust resulting from the varying inertia within the cavity. I need to have some data before putting numbers to the thrust, maybe someone else is curious enough to do that. I'm happy that the thrust points in the right direction. See the text on my drawing for my explanation.
The question is, physically, what is responsible for the change in inertial mass of the particle in the picture ?

I thought Prof. M had already figured that out?
OK
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 12:27 am
It is incorrect to think that it is a truncated cone on the inside.  Everything shows that it is a cylinder on one end joined to a truncated cone on the other end.  The mode shapes for such a geometric body are different than the mode shapes for a truncated cone as modeled by Egan.

And I don't think that the cylinder is there by accident. Somebody thought this through.


Yeah it looks like they put a can inside the cone for some reason. Good eye. Still I wanna see those modes.

OK, we can put it this way:

1) It is the first (lowest) mode of Egan for the truncated cone on the inside (next to the larger surface)

plus

2) the first (lowest) mode for the cylindrical can (located next to the smaller surface)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 12:31 am
We're reaching the limit of what we can accomplish here. We've gone through a lot of ideas, excluding some and including others and we arrived at some slightly different yet congruent conclusions which may describe the anomalous thrust. They now need to be verified by peer review and experiment. Seems that any kind of seemingly reactionless drive requires a fundamental rethinking of the details of inertia, coupled with a more thorough understanding and verification of quantum thrust. Supporting data was included in the discussion. Hopefully our conclusions are read by others.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/10/2014 12:31 am
It is incorrect to think that it is a truncated cone on the inside.  Everything shows that it is a cylinder on one end joined to a truncated cone on the other end.  The mode shapes for such a geometric body are different than the mode shapes for a truncated cone as modeled by Egan.

And I don't think that the cylinder is there by accident. Somebody thought this through.


Yeah it looks like they put a can inside the cone for some reason. Good eye. Still I wanna see those modes.

OK, we can put it this way:

1) It is the first (lowest) mode of Egan for the truncated cone on the inside (next to the larger surface)

plus

2) the first (lowest) mode for the cylindrical can (located next to the smaller surface)


Yup, that works

And it could account for the small freq diff depending on which mode is dominant.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 12:33 am
It is incorrect to think that it is a truncated cone on the inside.  Everything shows that it is a cylinder on one end joined to a truncated cone on the other end.  The mode shapes for such a geometric body are different than the mode shapes for a truncated cone as modeled by Egan.

And I don't think that the cylinder is there by accident. Somebody thought this through.


Yeah it looks like they put a can inside the cone for some reason. Good eye. Still I wanna see those modes.

OK, we can put it this way:

1) It is the first (lowest) mode of Egan for the truncated cone on the inside (next to the larger surface)

plus

2) the first (lowest) mode for the cylindrical can (located next to the smaller surface)


Gotta see the COSMOL plot and see if it agrees.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 12:34 am
It is incorrect to think that it is a truncated cone on the inside.  Everything shows that it is a cylinder on one end joined to a truncated cone on the other end.  The mode shapes for such a geometric body are different than the mode shapes for a truncated cone as modeled by Egan.

And I don't think that the cylinder is there by accident. Somebody thought this through.


Yeah it looks like they put a can inside the cone for some reason. Good eye. Still I wanna see those modes.

OK, we can put it this way:

1) It is the first (lowest) mode of Egan for the truncated cone on the inside (next to the larger surface)

plus

2) the first (lowest) mode for the cylindrical can (located next to the smaller surface)


Yup, that works

This may also explain the mess that is going on at 1933 MHz, since the inside is not a pure geometrical body but a cylinder inside the smaller end of a truncated cone
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/10/2014 12:51 am
Congratulations, you just invented a propless sub.

Not yet he ain't.

There's an experimental apparatus there for the taking.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 12:57 am
Congratulations, you just invented a propless sub.

Not yet he ain't.

Ther's an experimental apparatus there for the taking.
Keep it secret from the Russian and Chinese navies will ya?  Sheeeez

Parla sotto voce

http://en.wikipedia.org/wiki/Magnetohydrodynamic_drive

This already is a thing, done differently.

The whole thing Dr. White is up to with QVPT is MHD on the QV and WIMPS.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/10/2014 01:05 am
Hopefully our conclusions are read by others.

E parlando di "sottovoce" ... Credo di dire, una voce razionale:

Do summarize, both for the peanut gallery, and for the class clown.

The expository writing skills are strong in this one.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 01:09 am
Is there really any way we can help move the science along any faster? Is this discussion followed?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/10/2014 01:20 am
That's the moment I passed the Turing test.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/10/2014 01:22 am
Is there really any way we can help move the science along any faster? Is this discussion followed?

Partly.  The spirit is willing, but the mind is weak.  [sotto voce: don't tell anybody  I said this.]  Do summarize. Experiments cost money. Thoughts do not.  You're a good writer.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 01:29 am
It's time to do some maths.

If the maths work.

Build a better one.

Then test it.

Title: Re: EM Drive Developments
Post by: ThinkerX on 10/10/2014 01:37 am
Quote
Do summarize, both for the peanut gallery, and for the class clown.

Agreed. 

If my feeble yet fascinated understanding is anywhere near the mark, this device might actually be workable.

(I found the notion of something similar (?) being used to propel a submarine downright fascinating.)

So...do the math's, do a summary, and if it can be tracked down again, put it in the 'Google Document' deal. 

Maybe DIYer or some other hands on type will build one of these things.
Title: Re: EM Drive Developments
Post by: aero on 10/10/2014 01:39 am
Truth be told, a summary of the process of this thread from concept to conclusion would make a good read. It would also be book length if the ideas that seemed viable at first were summarized and discarded. Of course, at this point they have all been discarded or dropped for lack of data. The problem with following up on any one of the ideas is in part, that the posts are so intermixed ... it would be the same problem for anyone who tried to summarize the ideas in any order but that could be worked as a single task at least.

If I felt strongly about it, I would save the thread as a print file, open several editor/word processor windows/files, then cut and paste from the print file into the appropriate editor. After that, tech writing ...
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 02:08 am
It's time to do some maths.

If the maths work.

Build a better one.

Then test it.

Before that, ya got to tell 's what 'ya think the Teflon dielectric is for 'n why ya wanta put it at the wide enda  :)
Title: Re: EM Drive Developments
Post by: aero on 10/10/2014 03:41 am
It's time to do some maths.

If the maths work.

Build a better one.

Then test it.

Before that, ya got to tell 's what 'ya think the Teflon dielectric is for 'n why ya wanta put it at the wide enda  :)

Here is a patent application that talks about an RF antenna design. Treat it as background.

Quote
In order to operate the RF antenna at sufficiently high power, the antenna needs to be cooled and insulated from the plasma by a dielectric material


So that is what the dielectric is for and why it is at the front end of the cavity. Of course Eagleworks didn't operate at high enough power to need cooling. Think about why insulation of the feed power allowed a thrust but without the insulation, it didn't.

You can put an additional dielectric at the base, but that would not insulate the feed power.

http://www.google.com/patents/US20140070697 (http://www.google.com/patents/US20140070697)
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/10/2014 04:01 am
This seems to have at least some elements in common with the device tested by Eagleworks:

http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster

Quote
There are two main types of MPD thrusters, applied-field and self-field. Applied-field thrusters have magnetic rings surrounding the exhaust chamber to produce the magnetic field, while self-field thrusters have a cathode extending through the middle of the chamber. Applied fields are necessary at lower power levels, where self-field configurations are too weak. Various propellants such as xenon, neon, argon, hydrogen, hydrazine, and lithium have been used, with lithium generally being the best performer.

According to Edgar Choueiri magnetoplasmadynamic thrusters have input power 100-500 kilowatts, exhaust velocity 15-60 kilometers per second, thrust 2.5-25 newtons and efficiency 40-60 percent

And:

http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket


Quote
VASIMR can be most basically thought of as a convergent-divergent nozzle for ions and electrons. The propellant (a neutral gas such as argon or xenon) is first injected into a hollow cylinder surfaced with electromagnets. Upon entry into the engine, the gas is first heated to a “cold plasma” by a helicon RF antenna (also known as a “coupler”) which bombards the gas with electromagnetic waves, stripping electrons off the argon or xenon atoms and leaving plasma consisting of ions and loose electrons to continue down the engine compartment. By varying the amount of energy dedicated to RF heating and the amount of propellant delivered for plasma generation VASIMR is capable of either generating low-thrust, high–specific impulse exhaust or relatively high-thrust, low–specific impulse exhaust.[4] The second phase is a strong electromagnet positioned to compress the ionized plasma in a similar fashion to a convergent-divergent nozzle that compresses gas in traditional rocket engines.

A second coupler, known as the Ion Cyclotron Heating (ICH) section, emits electromagnetic waves in resonance with the orbits of ions and electrons as they travel through the engine. Resonance of the waves and plasma is achieved through a reduction of the magnetic field in this portion of the engine which slows down the orbital motion of the plasma particles. This section further heats the plasma to temperatures upwards of 1,000,000 kelvin — about 173 times the temperature of the Sun’s surface

Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 01:16 pm
Does McCulloch's quantised inertia theory make testable astrophysics predictions?

Yes.

For example, it is known that galaxies and galaxy clusters have rotational velocities apparently too fast to allow them to be gravitationally bound by their visible matter. This has been attributed to the presence of invisible (dark) matter, but so far dark matter has not been directly detected.

McCulloch has shown that his model (that modifies inertial mass by assuming it is caused by Unruh radiation, which is subject to a Hubble-scale Casimir effect) predicts the outer rotational velocity of dwarf and disk galaxies, and galaxy clusters, within error bars, without dark matter or adjustable parameters.

So detection (or lack of detection) of a significant amount of dark matter is an astrophysical test of the theory.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 01:37 pm
I need help. PTFE monomers appear to be chiral to me as seen in a globe model of the molecules, but I have no idea if it is magnetochiral.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 01:54 pm
I need help. PTFE monomers appear to be chiral to me as seen in a globe model of the molecules, but I have no idea if it is magnetochiral.
PTFE is a thermoplastic.  As a polymer it can be semi-crystalline   The crystallinity is governed by the processing method and the rate of cooling after processing. Higher rates of cooling suppress crystallite formation, resulting in lower degrees of crystallinity.

The magnetic properties of Teflon can also be tuned by strain:  http://www.nature.com/ncomms/journal/v3/n3/fig_tab/ncomms1689_F2.html

There are different types, and what's most important, as I previously discussed there is a transition near room temperature that affects the structure, and therefore its chirality.

See this page in this book:  http://goo.gl/ot67GB

Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 02:42 pm
I need help. PTFE monomers appear to be chiral to me as seen in a globe model of the molecules, but I have no idea if it is magnetochiral.

OK, I took the time to go through all the pages in which you have posted, looking for the original reference you use to place importance on the chirality of Teflon.  I could not find such reference. Please post the link again, as I would like to check whether it can possibly relate to a thermoplastic semi-crystalline polymer with transitions near room temperature, and in particular to Teflon.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 02:51 pm
I need help. PTFE monomers appear to be chiral to me as seen in a globe model of the molecules, but I have no idea if it is magnetochiral.

OK, I took the time to go through all the pages in which you have posted, looking for the original reference you use to place importance on the chirality of Teflon.  I could not find such reference. Please post the link again, as I would like to check whether it can possibly relate to a thermoplastic semi-crystalline polymer with transitions near room temperature, and in particular to Teflon.

Well the whole notion of chirality was an idea I had while trying to invoke a better linear asymmetry in a tube of dielectric, so I could explain Cannae, and also explain if the dielectric was important or not in EMdrive; days later it became crystal clear that for emdrive to work, you had to react with something in order to move, then I found this paper and my heart started beating rapidly.......

http://arxiv-web3.library.cornell.edu/abs/1404.5990



Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 03:13 pm
I need help. PTFE monomers appear to be chiral to me as seen in a globe model of the molecules, but I have no idea if it is magnetochiral.

OK, I took the time to go through all the pages in which you have posted, looking for the original reference you use to place importance on the chirality of Teflon.  I could not find such reference. Please post the link again, as I would like to check whether it can possibly relate to a thermoplastic semi-crystalline polymer with transitions near room temperature, and in particular to Teflon.

Well the whole notion of chirality was an idea I had while trying to invoke a better linear asymmetry in a tube of dielectric, so I could explain Cannae, and also explain if the dielectric was important or not in EMdrive; days later it became crystal clear that for emdrive to work, you had to react with something in order to move, then I found this paper and my heart started beating rapidly.......

http://arxiv-web3.library.cornell.edu/abs/1404.5990
The paper provides a  theoretical calculation, no experiments to verify it.   Common Teflon is only semi-crystalline and a thermoplastic, it is not that ordered.  Not much can be said without knowing the specific manufacturing method, but even if the paper's calculation would be correct (an unverified assumption) it seems to me that commonly available Teflon would not be an ideal material.  It would have to have been manufactured with the intent to enhance its order and anisotropy, and even then it is very unclear to me why would a researcher use such a nonlinear material with transitions occurring in the room temperature range, particularly in a lab like Eagleworks that to my knowledge did not fully characterize the Teflon used for the experiments (no FTIR, DSC, TMA, TGA, DTMA, thermal conductivity vs Temp, MTS, and certainly no measurements to characterize its anisotropy, etc.).  According to our previous discussions, the NASA report shows that if there is something useful in this respect to Teflon it is more likely to be the result of chance than experimental design.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 03:25 pm
Well in generic terms, it looks chiral. Magnetochiral? I don't know. Given the shape of the emdrive cone and the nature of the poynting vector flowing from A to B. I don't think the magnetochiral nature of the material is required for the thing to work, inasmuch as a magnetochiral material would be an optimization; making it work better. The arxiv paper was assuming a spherical universe and no modification of inertia.

Asymmetries in the system already:
1. Linear asymmetry
2. Poynting vector has defined direction by diminishing Q
3. magnetochirality of teflon?????

I think we have enough.

Agreed? Yes or no?
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 03:29 pm
Well in generic terms, it looks chiral. Magnetochiral? I don't know. Given the shape of the emdrive cone and the nature of the poynting vector flowing from A to B. I don't think the magnetochiral nature of the material is required for the thing to work, inasmuch as a magnetochiral material would be an optimization; making it work better. The arxiv paper was assuming a spherical universe and no modification of inertia.

Asymmetries in the system already:
1. Linear asymmetry
2. Poynting vector has defined direction by diminishing Q
3. magnetochirality of teflon?????

I think we have enough.

Agreed? Yes or no?

My understanding is that from the point of view of the quantised inertia explanation, what matters is the acceleration occurring at the boundaries (the boundary surfaces provided by the copper walls and the boundary surface of the dielectric) rather than the deep interior of the copper wall or the deep interior of the dielectric:

<<This is why I'm thinking the EmDrive walls might make a horizon: MiHsC assumes that inertia is caused by Unruh waves and the Hubble horizon is a boundary for information so all patterns within the cosmos must close there otherwise they let us deduce what lies beyond (this looks like a Hubble-scale Casimir effect) this includes the Unruh waves, so it affects inertia. Now, for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field, so the Unruh wave patterns have to close at the wall just as at the Hubble horizon (but for a different reason), so we have a mini-MiHsC going on. In both cosmic & mini cases it seems to explain anomalies.>>  http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html

There is a "skin penetration" of this into the copper, and the dielectric, but just a "skin"
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 03:32 pm
Well in generic terms, it looks chiral. Magnetochiral? I don't know. Given the shape of the emdrive cone and the nature of the poynting vector flowing from A to B. I don't think the magnetochiral nature of the material is required for the thing to work, inasmuch as a magnetochiral material would be an optimization; making it work better. The arxiv paper was assuming a spherical universe and no modification of inertia.

Asymmetries in the system already:
1. Linear asymmetry
2. Poynting vector has defined direction by diminishing Q
3. magnetochirality of teflon?????

I think we have enough.

Agreed? Yes or no?

My understanding is that from the point of view of the quantised inertia explanation, what matters is the acceleration occurring at the boundaries (the boundary surfaces provided by the copper walls and the boundary surface of the dielectric) rather than the interior of the copper wall or the interior of the dielectric:

<<This is why I'm thinking the EmDrive walls might make a horizon: MiHsC assumes that inertia is caused by Unruh waves and the Hubble horizon is a boundary for information so all patterns within the cosmos must close there otherwise they let us deduce what lies beyond (this looks like a Hubble-scale Casimir effect) this includes the Unruh waves, so it affects inertia. Now, for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field, so the Unruh wave patterns have to close at the wall just as at the Hubble horizon (but for a different reason), so we have a mini-MiHsC going on. In both cosmic & mini cases it seems to explain anomalies.>>

It is both, inside and outside; at the same time. The universe inside the cavity is finite. Therefore any accelerating particle inside the cavity gains inertia. Inside the cavity, the edge of the universe is inertial. The universe outside is expanding, invoking Unruh, modifying inertia. In the real universe outside, nothing is inertial.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 03:34 pm
Well in generic terms, it looks chiral. Magnetochiral? I don't know. Given the shape of the emdrive cone and the nature of the poynting vector flowing from A to B. I don't think the magnetochiral nature of the material is required for the thing to work, inasmuch as a magnetochiral material would be an optimization; making it work better. The arxiv paper was assuming a spherical universe and no modification of inertia.

Asymmetries in the system already:
1. Linear asymmetry
2. Poynting vector has defined direction by diminishing Q
3. magnetochirality of teflon?????

I think we have enough.

Agreed? Yes or no?

My understanding is that from the point of view of the quantised inertia explanation, what matters is the acceleration occurring at the boundaries (the boundary surfaces provided by the copper walls and the boundary surface of the dielectric) rather than the interior of the copper wall or the interior of the dielectric:

<<This is why I'm thinking the EmDrive walls might make a horizon: MiHsC assumes that inertia is caused by Unruh waves and the Hubble horizon is a boundary for information so all patterns within the cosmos must close there otherwise they let us deduce what lies beyond (this looks like a Hubble-scale Casimir effect) this includes the Unruh waves, so it affects inertia. Now, for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field, so the Unruh wave patterns have to close at the wall just as at the Hubble horizon (but for a different reason), so we have a mini-MiHsC going on. In both cosmic & mini cases it seems to explain anomalies.>>

It is both, inside and outside; at the same time. The universe inside the cavity is finite. Therefore any accelerating particle inside the cavity gains inertia. Inside the cavity, the edge of the universe is inertial. The universe outside is expanding, invoking Unruh, modifying inertia.

<<for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long>> 

It is the acceleration , not the speed, that affects the inertia.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 03:36 pm
Well in generic terms, it looks chiral. Magnetochiral? I don't know. Given the shape of the emdrive cone and the nature of the poynting vector flowing from A to B. I don't think the magnetochiral nature of the material is required for the thing to work, inasmuch as a magnetochiral material would be an optimization; making it work better. The arxiv paper was assuming a spherical universe and no modification of inertia.

Asymmetries in the system already:
1. Linear asymmetry
2. Poynting vector has defined direction by diminishing Q
3. magnetochirality of teflon?????

I think we have enough.

Agreed? Yes or no?

My understanding is that from the point of view of the quantised inertia explanation, what matters is the acceleration occurring at the boundaries (the boundary surfaces provided by the copper walls and the boundary surface of the dielectric) rather than the interior of the copper wall or the interior of the dielectric:

<<This is why I'm thinking the EmDrive walls might make a horizon: MiHsC assumes that inertia is caused by Unruh waves and the Hubble horizon is a boundary for information so all patterns within the cosmos must close there otherwise they let us deduce what lies beyond (this looks like a Hubble-scale Casimir effect) this includes the Unruh waves, so it affects inertia. Now, for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field, so the Unruh wave patterns have to close at the wall just as at the Hubble horizon (but for a different reason), so we have a mini-MiHsC going on. In both cosmic & mini cases it seems to explain anomalies.>>

It is both, inside and outside; at the same time. The universe inside the cavity is finite. Therefore any accelerating particle inside the cavity gains inertia. Inside the cavity, the edge of the universe is inertial. The universe outside is expanding, invoking Unruh, modifying inertia.

<<for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long>> 

It is the acceleration , not the speed, that affects the inertia.

I just said that.

"Therefore any accelerating particle inside the cavity gains inertia."

Outside the cavity is the opposite, the QV itself is the inertial observer.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 03:39 pm

The Summary
A living document.
Probably way premature and more than likely incorrect on many fronts. Anyway the summary in general terms.

How I suppose EMdrive works based on my interpretation of all other theories I researched regarding the extrinsic origins of inertial mass, put into context of the most fundamental element common to them all, and the most fundamental property of inertia itself, resistance to acceleration over time, informed by the theory of modified inertia; MiHsC, QM, GR, and SR. The scientific method was applied equally with the philosophy of not placing arbitrary limits on systems which are limitless.

In a nutshell:

Begin with the universe we live in.
This universe is ever expanding at an accelerating rate in all directions
More or less evenly in all directions, but not exactly in all directions.
In this universe, the notion of exactly 0 acceleration with respect to the universe itself is impossible.
A hypothetical particle experiencing 0 accelerations would have 0 inertia, but this condition is impossible.
In this universe, the notion of very very small accelerations with uncertain magnitude is very possible and evident at the edges of galaxies and in intergalactic space.
In this universe, we observe a definite arrow of time, the rate of which time passes is variable between regions based on the shape of spacetime curvatures and relative velocities in local and global contexts, but always positive.
The sum of spacetime is set forth by all the observable matter, energy, interactions, and the mostly unobservable vacuum composed of all possible energy levels in their ground state. Kept in check by the physical laws governing that universe.

None of the laws of this universe at large can be broken.

None of the laws of this universe can describe the universe to infinity, meaning there is always a remainder of uncertainty. Because of this, theories of modified inertia by virtue of being correct, do not invalidate GR; they further expand upon it.

The EEP was formulated with a supporting philosophical background which excludes data which is unobservable, deeming it insignificant. To this effect, EEP was given an artificial absolute equivalence, which in the context of infinity falls apart. EEP is correct within everyday experience, but incorrect beyond what can be directly observed.

This philosophy of science is incongruent with the notion of infinity, and infinite uncertainty.

In the notion of infinity, insignificant values do not follow.

If the laws governing the world we live in are truly derived from properties of the limitless universe surrounding us, it is illogical to place an artificial limit on the precision of a theory describing that universe by invoking an unbreakable equivalence.

Uncertainty gives rise to the stochastic nature of our universe and the probability based world we live in. This insight comes full circle with the question; what is and is not observable?

This philosophy of science is evident in the uncertainty principle.

EEP and the uncertainty principle are not congruent.

No wonder GR and QM don't agree.

Our inability to adapt GR in the face of new data is the other.

This reduces down further to information and mathematical theory and philosophy, to which remains fully unexplored.




Within said universe,
Construct an asymmetric metal cone shape and enclose both ends.
The resulting enclosed space is subject to all the laws of the universe that contains it.
The boundary conditions set forth by the mechanical properties, geometry, and electromagnetic properties of the enclosed metal space serve to artificially create an apparent event horizon between the inside and outside space of the device.
Within the device, the universe is exactly the same as the universe outside, except for the shadow created in the electromagnetic spectrum (both vacuum and real).

As above in the real universe, spacetime is defined by all the observable matter, energy, interactions, and the mostly unobservable vacuum composed of all possible energy levels in their ground state.

Gravity is not blocked.

Therefore, as a universe is defined above, the universe inside the device is slightly different from outside by virtue of its boundary conditions.

The device contains its own unique universe.

Governed by the geometry of the spacetime contained within the cavity, set by its boundaries. The universe is finite and not expanding.
The shape of spacetime within has a conical bias. This serves to widen spacetime at the large end and shorten spacetime at the small end, from where a nearly perfect sphere was before. The conditions within the conical cavity are almost exactly the same as the conditions outside the cavity, but not exactly. This difference is governed by the shadow created within and resulting in very slight modification to the shape of spacetime within the cavity.

This tiny change within the cavity is extremely small, but in the context of infinity, and the notion of continual acceleration of particles subject to those extremely small differences, the effects continually compound allowing work to be accomplished.

Within the device, the arrow of time flows from the small end to the large end. As in any universe, time is positive and flows at a variable rate as a function of position in spacetime and velocity as defined by general relativity.

Inertia within the device is governed by a particles interactions with the distant universe, as a function of time. As in any universe.

Within the device at T=0, inertia and time cease to have meaning in the singularity.

Due to the lower ground state within the cavity, a result of the shadow created by the cavity, particles start out with a smaller inertia than would be possible otherwise. The particles are being accelerated less by the rest of the universe by virtue of some modes are blocked out. They are colder.

As a particle moves from T=0, through the arrow of time, the inertia of that particle decreases as a function of its acceleration with respect to the non expanding boundary of the universe.

The rate of which time passes for said particle is a function of its velocity and position in spacetime with respect to T=0.

A particle exactly at the far end of the cavity which isn't moving with respect to the universe contained within experiences very little acceleration, resulting in very little inertia.

A hypothetical particle inside this universe experiencing no acceleration, experiences zero inertia.

This hypothetical particle has an extremely low probability of ever existing because it is still subject to the conditions of the universe outside the cavity, by virtue of what was not excluded by the boundary conditions of the cavity; which still influence the inside of the device.




Outside the asymmetrical metal cone, the entire device is treated as an asymmetric particle in context to the scale of the universe at large.

This asymmetrical particle is subject to the dynamics set forth by its mechanical properties, geometry, and electromagnetic properties and the interactions of the device with the geometry of the expanding universe at large.

Given this device exists within a universe continually accelerating away from it in all directions more less equally but not exactly, at an increasing rate, this device experiences a very small asymmetrical inertial bias across the length of the cone.

The dynamics of this inertial bias are set forth by the inclusion and exclusion of Unruh waves between the boundary conditions of the device's walls and the Hubble horizon. The dynamics of which are defined within the theory of MiHsC.
The larger end of the cone experiences more inertia than the small end.
This gives a very small dipole moment to the force required to accelerate the device in space.
It is easier to push the device toward the small end than toward the large end.
Inertia of the entire system is never lowered.

When the device is excited with radio frequencies internally, photons comprising the electromagnetic waves travel the length of the device, interacting and transferring their momentum to particles within the cavity. The particles within the dielectric exist along an inertial gradient down the length of the device.

The electromagnetic waves within the device propagate as defined by resonance modes of enclosed conical cavities. The poynting vector of the cavity is along the Z axis from small end to large end. The energy flow of the poynting vector is maximized by the Q factor of the device. The final product of the Z axis Q factor being most critical to device operation.

Magnetochiral dielectric materials used within the device provide a vector for transfer of momentum from photons to the QED vacuum. Not from the oscillation of magnetic fields within the device, but by the net magnetic energy flow defined by the poynting vector of the rf within the device.

In essence a quantum rocket nozzle.

Proper placement and orientation of chiral dielectric materials along the Z axis poynting vector in areas of maximum magnetic energy flux and flow allow for the transfer of momentum from the photons to the diamagnetic QED vacuum. The true nature of which I don't understand, given the fleeting and stochastic nature of the QV.

The resulting transfer of momentum results in a very small acceleration of the device by classical mechanics. The effects of this small acceleration build over time, resulting in a useful velocity of the device.

An observer standing behind the device would feel no effect from the device in operation.

The effeciency of the device is simply an engineering problem. The addition of superconductor technologies can greatly increase the Q factor of the device, increasing thrust.

As the device accelerates to greater speeds toward the Hubble horizon, a Rindler horizon approaches the device from behind as a function of velocity.

This has the effect to exclude possible Unruh modes behind the device, by virtue of the boundary conditions set forth by the walls of the device and the approaching causal event horizon.

At the same time, Unruh modes in front of the device are left unexcluded by virtue of the nature of the boundary conditions set by the walls of the device and the ever expanding and accelerating universe.

This has the effect to induce an inertial bias on the device, whereas inertia is greater at the large end then the small end.

This inertial bias builds with continued acceleration of the device, requiring more energy to be expended to accelerate the device, resulting in the inability to approach or exceed C.

The device has come full circle, return to start.

Supporting studies, theories, and arguments are documented within the evolution of the forum thread.

I just forced myself to believe in an impossible thing.

I'm going to go think about something else now for a while.

Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 03:42 pm
Well in generic terms, it looks chiral. Magnetochiral? I don't know. Given the shape of the emdrive cone and the nature of the poynting vector flowing from A to B. I don't think the magnetochiral nature of the material is required for the thing to work, inasmuch as a magnetochiral material would be an optimization; making it work better. The arxiv paper was assuming a spherical universe and no modification of inertia.

Asymmetries in the system already:
1. Linear asymmetry
2. Poynting vector has defined direction by diminishing Q
3. magnetochirality of teflon?????

I think we have enough.

Agreed? Yes or no?

My understanding is that from the point of view of the quantised inertia explanation, what matters is the acceleration occurring at the boundaries (the boundary surfaces provided by the copper walls and the boundary surface of the dielectric) rather than the interior of the copper wall or the interior of the dielectric:

<<This is why I'm thinking the EmDrive walls might make a horizon: MiHsC assumes that inertia is caused by Unruh waves and the Hubble horizon is a boundary for information so all patterns within the cosmos must close there otherwise they let us deduce what lies beyond (this looks like a Hubble-scale Casimir effect) this includes the Unruh waves, so it affects inertia. Now, for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field, so the Unruh wave patterns have to close at the wall just as at the Hubble horizon (but for a different reason), so we have a mini-MiHsC going on. In both cosmic & mini cases it seems to explain anomalies.>>

It is both, inside and outside; at the same time. The universe inside the cavity is finite. Therefore any accelerating particle inside the cavity gains inertia. Inside the cavity, the edge of the universe is inertial. The universe outside is expanding, invoking Unruh, modifying inertia.

<<for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long>> 

It is the acceleration , not the speed, that affects the inertia.

I just said that.

"Therefore any accelerating particle inside the cavity gains inertia."

Outside the cavity is the opposite, the QV itself is the inertial observer.

It is not any accelerating particle that matters for the horizon.  It is only those that undergo an acceleration such that the Unruh waves fit within the dimensions of the flat surfaces of the truncated cone, or the dielectric.
That rules out a wide range of accelerations, and restricts what matters to the surfaces (including a thin skin effect)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 03:45 pm
Well in generic terms, it looks chiral. Magnetochiral? I don't know. Given the shape of the emdrive cone and the nature of the poynting vector flowing from A to B. I don't think the magnetochiral nature of the material is required for the thing to work, inasmuch as a magnetochiral material would be an optimization; making it work better. The arxiv paper was assuming a spherical universe and no modification of inertia.

Asymmetries in the system already:
1. Linear asymmetry
2. Poynting vector has defined direction by diminishing Q
3. magnetochirality of teflon?????

I think we have enough.

Agreed? Yes or no?

My understanding is that from the point of view of the quantised inertia explanation, what matters is the acceleration occurring at the boundaries (the boundary surfaces provided by the copper walls and the boundary surface of the dielectric) rather than the interior of the copper wall or the interior of the dielectric:

<<This is why I'm thinking the EmDrive walls might make a horizon: MiHsC assumes that inertia is caused by Unruh waves and the Hubble horizon is a boundary for information so all patterns within the cosmos must close there otherwise they let us deduce what lies beyond (this looks like a Hubble-scale Casimir effect) this includes the Unruh waves, so it affects inertia. Now, for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field, so the Unruh wave patterns have to close at the wall just as at the Hubble horizon (but for a different reason), so we have a mini-MiHsC going on. In both cosmic & mini cases it seems to explain anomalies.>>

It is both, inside and outside; at the same time. The universe inside the cavity is finite. Therefore any accelerating particle inside the cavity gains inertia. Inside the cavity, the edge of the universe is inertial. The universe outside is expanding, invoking Unruh, modifying inertia.

<<for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long>> 

It is the acceleration , not the speed, that affects the inertia.

I just said that.

"Therefore any accelerating particle inside the cavity gains inertia."

Outside the cavity is the opposite, the QV itself is the inertial observer.

It is not any accelerating particle that matters for the horizon.  It is only those that undergo an acceleration such that the Unruh waves fit within the dimensions of the flat surfaces of the truncated cone, or the dielectric.
That rules out a wide range of accelerations, and restricts what matters to the surfaces (including a thin skin effect)

All Unruh does for you inside the cavity is make sure nothing violates C.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 03:52 pm
...

All Unruh does for you inside the cavity is make sure nothing violates C.
We are discussing whether the bulk interior of the copper walls and the bulk interior of the dielectric plays a significant role as compared to the boundary surfaces.

At one point recently I understood you to ask or suggest that the cylindrical "can" inside the truncated cone was a dielectric.  That would make it a hugely thick dielectric.

Let me ask you: if you think that the inner bulk inner material of the dielectric plays an important role, then do you think that a dielectric several inches thick would be even better ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 03:58 pm
...

All Unruh does for you inside the cavity is make sure nothing violates C.
We are discussing whether the bulk interior of the copper walls and the bulk interior of the dielectric plays a significant role as compared to the boundary surfaces.

At one point recently I understood you to ask or suggest that the cylindrical "can" inside the truncated cone was a dielectric.  That would make it a hugely thick dielectric.

Let me ask you: if you think that the inner bulk inner material of the dielectric plays an important role, then do you think that a dielectric several inches thick would be even better ?

Sure would, bigger is better. As long as you don't collapse the EM field. You gotta engineer it.

On the flip side, a bigger antenna can impart more power. A bigger loop probe=more power. A giant door knob probe=more power.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 04:05 pm
...

All Unruh does for you inside the cavity is make sure nothing violates C.
We are discussing whether the bulk interior of the copper walls and the bulk interior of the dielectric plays a significant role as compared to the boundary surfaces.

At one point recently I understood you to ask or suggest that the cylindrical "can" inside the truncated cone was a dielectric.  That would make it a hugely thick dielectric.

Let me ask you: if you think that the inner bulk inner material of the dielectric plays an important role, then do you think that a dielectric several inches thick would be even better ?

Sure would, bigger is better. As long as you don't collapse the EM field. You gotta engineer it.

On the flip side, a bigger antenna can impart more power. A bigger loop probe=more power. A giant door knob probe=more power.

OK we strongly disagree.  I don't think that a very thick dielectric would be better, actually I think that it would be worse.  I think that what matters most is the surface of the dielectric, not its inner bulk.

This is testable.  So far all the indications is that they used a  very small diameter, high aspect ratio (length to diameter) dielectric for the Canae device and a flat disk doughnut for the truncated cone.

Both of the dielectrics they used are the contrary of what you would propose, as the small diameter cylinder with high length to diameter, and the flat doughnut disk  (with thickness significantly smaller than its inner and outer diameters) maximize surface to bulk volume ratio.
Title: Re: EM Drive Developments
Post by: aero on 10/10/2014 05:43 pm
At one point back up thread there was a discussion that included the velocity of DM inside the cavity. I wondered if we could treat DM to behave like an ideal gas WRT density and volume. That is,

V2 = V1*rho1/rho2

Divide Volume by 1 m2 on both sides lets me use velocity in the equation.

For DM data, I use: http://arxiv.org/pdf/0806.3767v1.pdf (http://arxiv.org/pdf/0806.3767v1.pdf)

1 - Use Solar escape velocity at earth's orbit, 42.1 km/s, galactic DM density 2E12 kg/AU3 and DM density at earth orbit, 5E16 kg/AU3.

The equation gives DM velocity at earth orbit = 1.6 m/s

2. Try again. Use the velocity of the comet Siding Spring at Mars orbit as the velocity of DM at Mars, 57 km/s and DM density at Mars orbit about 5E15. This gives DM velocity at Earth orbit of 5.7 km/s.

Well, 1.6 m/s seems very low, and such a high velocity at Mars orbit (Siding Spring) seems unjustifiable. Still, the velocities are sun centered, and since the earth's orbital velocity about the sun is about 30 km/s, it dominates.

I conclude that the velocity of DM at the earth's surface is about 30,000 m/s.

Since F = dm*Ve, for 50 micro N thrust, dm = 5.0E-5/3.0E+4, = 1.67 E-9 kg/s if dm were due to change in inertial mass of dark matter in the cavity.

Well, no - way to much change. Assume the cavity area is 0.1 m^2 * 30,000 m/s gives total swept volume per second of 3,000 m^2, and DM density is like 5E-16 kg/m^3 so total swept mass is 1.5E-13 kg. It doesn't work out.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/10/2014 05:47 pm
Quote from: Mulletron
I just forced myself to believe in an impossible thing.

What?  That I'm a super genius?  Think about that!

http://www.youtube.com/watch?v=STeVTzWelns
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 06:04 pm
Well what I described doesn't exactly describe what is happening inside the EMdrive, because the EMdrive is flat at both ends. The one I described is a cone with a half circle back aft. That, in my view, qualifies as a valid fork toward another direction. If my ideas can stand up to ridicule, I'd like to call the new drive.....the MiDrive.

What would happen if (say you were flying through space, getting closer and closer to C) the internal and external Rindler Horizons both met the point of the device at the same time?

Would you yoink out of existence? Or would they invert to the other side?

Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 06:16 pm
...
Well the whole notion of chirality was an idea I had while trying to invoke a better linear asymmetry in a tube of dielectric, so I could explain Cannae, and also explain if the dielectric was important or not in EMdrive; days later it became crystal clear that for emdrive to work, you had to react with something in order to move, then I found this paper and my heart started beating rapidly.......

http://arxiv-web3.library.cornell.edu/abs/1404.5990


On the "Casimir momentum" transferred to a chiral molecule in a strong magnetic field I find the following (2013)  presentation (http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf ) much clearer than the last paper.

Please observe:

1) The momentum is only transferred as an (infinitesimal duration) impulse during switching of the magnetic field

2) It requires simultaneous breakdown of Time symmetry and Parity symmetries.  The only force in nature that allows these breakdowns (of Time symmetry & Parity symmetry) is the weak force, so the effect must be associated with the weak force (related to radiation) and the authors acknowledge this

3) Kinetic energy is supplied by the external magnetic field

4) The chiral molecule in the magnetic field acquires a kinetic momentum directed along B (the magnetic field vector) and proportional to the fine structure constant (related to the Casimir effect as explained by Schwinger) and the rotatory power (the chirality of the molecule + the magnetic field)

5) For common chiral compounds they estimate, for a magnetic field of 10 Tesla (much larger than the magnetic field in the tested EM drives) a delta velocity of only  Δv~ 1nm/s .  That is extremely small (a nanometer per second)

Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/10/2014 06:18 pm
...

All Unruh does for you inside the cavity is make sure nothing violates C.
We are discussing whether the bulk interior of the copper walls and the bulk interior of the dielectric plays a significant role as compared to the boundary surfaces.

At one point recently I understood you to ask or suggest that the cylindrical "can" inside the truncated cone was a dielectric.  That would make it a hugely thick dielectric.

Let me ask you: if you think that the inner bulk inner material of the dielectric plays an important role, then do you think that a dielectric several inches thick would be even better ?

I think that the tested cone has the large amount of dielectric, but that they came to the same conclusion (about surfaces) and have reduced it to the disk shown in the "optimized" diagram.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 06:23 pm
...

All Unruh does for you inside the cavity is make sure nothing violates C.
We are discussing whether the bulk interior of the copper walls and the bulk interior of the dielectric plays a significant role as compared to the boundary surfaces.

At one point recently I understood you to ask or suggest that the cylindrical "can" inside the truncated cone was a dielectric.  That would make it a hugely thick dielectric.

Let me ask you: if you think that the inner bulk inner material of the dielectric plays an important role, then do you think that a dielectric several inches thick would be even better ?

I think that the tested cone has the large amount of dielectric, but that they came to the same conclusion (about surfaces) and have reduced it to the disk shown in the "optimized" diagram.

That would be very interesting, as the magnetic field mode shape inside the "cylindrical can" dielectric part of the cavity would be governed by the inner diameter of the dielectric.  In essence we would have:

A) a smaller cylindrical cavity formed by the cylindrical hole of the dielectric annulus

and

B) the much larger truncated cone cavity downstream of the dielectric annulus

EDIT:  If the dielectric was a huge annulus, how did they accomplish this?  Did they use a thin Teflon pipe? Did they use a Teflon sheet and roll it into an annulus? 

If it is a Teflon sheet rolled to form a thin cylinder of ~9 inch diameter, then, again, the main effect of the dielectric is its surface.  Ditto for a thin Teflon pipe.

I would be very, very surprised if they used a Teflon rod 9 inch outer diameter with a small inner hole (of say 1 inch inner diameter) such that the bulk thickness of the Teflon would be important. Or if they used a solid rod of Teflon 9 inches in outer diameter, without any inner hole.

Also, that's not what the magnetic field (see attached, the blue arrows) seems to show.  If there was such a large dielectric it must have been a thin pipe or rolled  sheet, seems to me:

Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/10/2014 06:43 pm
...

All Unruh does for you inside the cavity is make sure nothing violates C.
We are discussing whether the bulk interior of the copper walls and the bulk interior of the dielectric plays a significant role as compared to the boundary surfaces.

At one point recently I understood you to ask or suggest that the cylindrical "can" inside the truncated cone was a dielectric.  That would make it a hugely thick dielectric.

Let me ask you: if you think that the inner bulk inner material of the dielectric plays an important role, then do you think that a dielectric several inches thick would be even better ?

I think that the tested cone has the large amount of dielectric, but that they came to the same conclusion (about surfaces) and have reduced it to the disk shown in the "optimized" diagram.

That would be very interesting, as the magnetic field mode shape inside the "cylindrical can" dielectric part of the cavity would be governed by the inner diameter of the dielectric.  In essence we would have:

A) a smaller cylindrical cavity formed by the cylindrical hole of the dielectric annulus

and

B) the much larger truncated cone cavity downstream of the dielectric annulus

EDIT:  If the dielectric was a huge annulus, how did they accomplish this?  Did they use a thin Teflon pipe? Did they use a Teflon sheet and roll it into an annulus? 

If it is a Teflon sheet rolled to form a thin cylinder of ~9 inch diameter, then, again, the main effect of the dielectric is its surface.  Ditto for a thin Teflon pipe.

I would be very, very surprised if they used a Teflon rod 9 inch outer diameter with a small inner hole (of say 1 inch inner diameter) such that the bulk thickness of the Teflon would be important.
Fnarr Dr Rodal fnarr. (Look up Viz comic (Finbar Saunders) and especially Roger's Profanisaurus.)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/10/2014 06:46 pm
...

All Unruh does for you inside the cavity is make sure nothing violates C.
We are discussing whether the bulk interior of the copper walls and the bulk interior of the dielectric plays a significant role as compared to the boundary surfaces.

At one point recently I understood you to ask or suggest that the cylindrical "can" inside the truncated cone was a dielectric.  That would make it a hugely thick dielectric.

Let me ask you: if you think that the inner bulk inner material of the dielectric plays an important role, then do you think that a dielectric several inches thick would be even better ?

I think that the tested cone has the large amount of dielectric, but that they came to the same conclusion (about surfaces) and have reduced it to the disk shown in the "optimized" diagram.

That would be very interesting, as the magnetic field mode shape inside the "cylindrical can" dielectric part of the cavity would be governed by the inner diameter of the dielectric.  In essence we would have:

A) a smaller cylindrical cavity formed by the cylindrical hole of the dielectric annulus

and

B) the much larger truncated cone cavity downstream of the dielectric annulus

EDIT:  If the dielectric was a huge annulus, how did they accomplish this?  Did they use a thin Teflon pipe? Did they use a Teflon sheet and roll it into an annulus? 

If it is a Teflon sheet rolled to form a thin cylinder of ~9 inch diameter, then, again, the main effect of the dielectric is its surface.  Ditto for a thin Teflon pipe.

I would be very, very surprised if they used a Teflon rod 9 inch outer diameter with a small inner hole (of say 1 inch inner diameter) such that the bulk thickness of the Teflon would be important. Or if they used a solid rod of Teflon 9 inches in outer diameter, without any inner hole.

Also, that's not what the magnetic field (see attached, the blue arrows) seems to show.  If there was such a large dielectric it must have been a thin pipe or rolled  sheet, seems to me:

* early analysis of Frustum B.jpg  makes me think it was a solid rod, initially anyway.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 06:48 pm

* early analysis of Frustum B.jpg  makes me think it was a solid rod, initially anyway.

Wow.  I admit to be very surprised at that !  A solid rod of Teflon 9 inches in diameter !

No wonder that supposedly Shawyer got rid of it  :)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/10/2014 06:54 pm

* early analysis of Frustum B.jpg  makes me think it was a solid rod, initially anyway.

Wow.  I admit to be very surprised at that !  A solid rod of Teflon 9 inches in diameter !

No wonder that supposedly Shawyer got rid of it  :)

Odd!  Thinking of Shawyers construction, his could have been filled w/ water, or oil.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/10/2014 06:58 pm
@Rodal
A solid rod of Teflon 9 inches in diameter !
Fnarr!
etc
I will shut up now..
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 07:03 pm

* early analysis of Frustum B.jpg  makes me think it was a solid rod, initially anyway.

Wow.  I admit to be very surprised at that !  A solid rod of Teflon 9 inches in diameter !

No wonder that supposedly Shawyer got rid of it  :)

Odd!  Thinking of Shawyers construction, his could have been filled w/ water, or oil.
Back to the respectable science here after Fnarrrrrrrrrrrrrr

A 9 inch solid rod of Teflon would be fairly isotropic with very little directional chirality.   

If it was extruded, I would expect a fair amount of shear mixing (therefore loss of directionality and chirality) in the throat of the extruder.  But it all depends on the dimensions of the throat of the extruder that extruded the Teflon rod.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/10/2014 07:10 pm

* early analysis of Frustum B.jpg  makes me think it was a solid rod, initially anyway.

Wow.  I admit to be very surprised at that !  A solid rod of Teflon 9 inches in diameter !

No wonder that supposedly Shawyer got rid of it  :)

Odd!  Thinking of Shawyers construction, his could have been filled w/ water, or oil.
Back to the respectable science here after Fnarrrrrrrrrrrrrr

A 9 inch solid rod of Teflon would be fairly isotropic with very little directional chirality.   

If it was extruded, I would expect a fair amount of shear mixing (therefore loss of directionality and chirality) in the throat of the extruder.  But it all depends on the dimensions of the throat of the extruder that extruded the Teflon rod.

Easily available up to 20.5 inch diameter !  http://www.enflo.com/molded_ptfe_rod.html
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 07:17 pm

* early analysis of Frustum B.jpg  makes me think it was a solid rod, initially anyway.

Wow.  I admit to be very surprised at that !  A solid rod of Teflon 9 inches in diameter !

No wonder that supposedly Shawyer got rid of it  :)

Odd!  Thinking of Shawyers construction, his could have been filled w/ water, or oil.
Back to the respectable science here after Fnarrrrrrrrrrrrrr

A 9 inch solid rod of Teflon would be fairly isotropic with very little directional chirality.   

If it was extruded, I would expect a fair amount of shear mixing (therefore loss of directionality and chirality) in the throat of the extruder.  But it all depends on the dimensions of the throat of the extruder that extruded the Teflon rod.

Easily available up to 20.5 inch diameter !  http://www.enflo.com/molded_ptfe_rod.html

They are injection molded from Enflo.

I expect practically no overall directional chirality from a 9 inch solid rod made by injection molding.

Even if the product had chirality when injected into the mold, there should be a lot of mixing as the filling takes place.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/10/2014 07:28 pm
Fnarr!
I couldn't resist!
No more I promise!
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 07:48 pm

* early analysis of Frustum B.jpg  makes me think it was a solid rod, initially anyway.

Wow.  I admit to be very surprised at that !  A solid rod of Teflon 9 inches in diameter !

No wonder that supposedly Shawyer got rid of it  :)

Odd!  Thinking of Shawyers construction, his could have been filled w/ water, or oil.
The NASA report never states what the dielectric used for the truncated cone was.  They write that the dielectric for the Canae device was Teflon.

They only state for the truncated cone:  <<There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber>>

However, since they removed it and then they inserted it again with apparent ease, it is likely that what they removed and re-inserted was a solid than a liquid, if the solid was not glued inside it.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/10/2014 07:56 pm

* early analysis of Frustum B.jpg  makes me think it was a solid rod, initially anyway.

Wow.  I admit to be very surprised at that !  A solid rod of Teflon 9 inches in diameter !

No wonder that supposedly Shawyer got rid of it  :)

Odd!  Thinking of Shawyers construction, his could have been filled w/ water, or oil.
The NASA report never states what the dielectric used for the truncated cone was.  They write that the dielectric for the Canae device was Teflon.

They only state for the truncated cone:  <<There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber>>

However, since they removed it and then they inserted it again with apparent ease, it is likely that what they removed and re-inserted was a solid than a liquid, if the solid was not glued inside it.

It looked like only Shawyers early device might have taken liquid.  That would have allowed him to experiment w/ different dielectric parameters.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/10/2014 08:00 pm
What would be the complications on conducting experiments in my garage?
I would need a copper frustum and optimised dielectric designed by you guys.
RF power source.
Suspend the whole thing from a wire and see if it moves.
Am I missing anything?
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 08:07 pm
What would be the complications on conducting experiments in my garage?
I would need a copper frustum and optimised dielectric designed by you guys.
RF power source.
Suspend the whole thing from a wire and see if it moves.
Am I missing anything?

Suspend it from the place that will give you the greatest height, as high as possible in a place with no air drafts.  > 20ft high would be nice.  Do you have access to an abandoned elevator shaft?


Use thin piano wire (strong and small diameter).  Use a laser to verify the small movement.

1 KWatt (as done by the Chinese) should give you ~0.3 Newtons.  Explore 1.5 to 3 GHz frequencies.
Take a movie and post it in our thread  :)
Title: Re: EM Drive Developments
Post by: aero on 10/10/2014 08:12 pm
And don't bake yourself with microwave or RF radiation, at least until after you post complete results :)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 08:35 pm
After I learned to let go of the absolute universality of EEP, I was then able to accept Wheeler-Feynman absorber theory (and all the other theories) as facets of the same interaction, expressed at different levels of interaction.

Thanks Dr. McCulloch for bringing order to the madness via your fresh insight on the true origin of inertial mass. I hope you are correct.

As the great Feynman is quoted, "All mass is interaction."
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 08:41 pm
After I learned to let go of the absolute universality of EEP, I was then able to accept Wheeler-Feynman absorber theory (and all the other theories) as facets of the same interaction, expressed at different levels of interaction.

Thanks Dr. McCulloch for bringing order to the madness via your fresh insight on the true origin of inertial mass. I hope you are correct.

As the great Feynman is quoted, "All mass is interaction."
Wheeler-Feynman absorber theory has no arrow of time: it implies time symmetry.  Feynman abandoned it for QED due to the problem of self-interactions. 

Does McCulloch's quantised inertia theory also imply time-symmetry?  I didn't notice that.

Also, my understanding of McCulloch's theory that it assumes that the inertial mass of an object is caused
by Unruh radiation resulting from its acceleration with respect to surrounding matter.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/10/2014 08:47 pm
What would be the complications on conducting experiments in my garage?
I would need a copper frustum and optimised dielectric designed by you guys.
RF power source.
Suspend the whole thing from a wire and see if it moves.
Am I missing anything?

Big battery
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 09:02 pm
After I learned to let go of the absolute universality of EEP, I was then able to accept Wheeler-Feynman absorber theory (and all the other theories) as facets of the same interaction, expressed at different levels of interaction.

Thanks Dr. McCulloch for bringing order to the madness via your fresh insight on the true origin of inertial mass. I hope you are correct.

As the great Feynman is quoted, "All mass is interaction."
Wheeler-Feynman absorber theory has no arrow of time: it implies time symmetry.  For QED it has even more problems, that's why Feynman abandoned it for QED (due to the problem of self-interactions). 

Does McCulloch's quantised inertia theory also imply time-symmetry? no arrow of time?  I didn't notice that.

Also, my understanding of McCulloch's theory that it assumes that the inertial mass of an object is caused
by Unruh radiation resulting from its acceleration with respect to surrounding matter.

It modifies the context of the origin of inertial mass to fit the universe.

Said a different way, "The origin of all mass is all interaction."

Not just some interaction. Not just distant matter, and the gravity from it.

Another core tenet is that objects undergoing very very very small acceleration have very very very low inertial mass.

Unruh radiation is a fancy way of saying ALL possible radiation.
Title: Re: EM Drive Developments
Post by: zen-in on 10/10/2014 09:15 pm
What would be the complications on conducting experiments in my garage?
I would need a copper frustum and optimised dielectric designed by you guys.
RF power source.
Suspend the whole thing from a wire and see if it moves.
Am I missing anything?

Suspend it from the place that will give you the greatest height, as high as possible in a place with no air drafts.  > 20ft high would be nice.  Do you have access to an abandoned elevator shaft?


Use thin piano wire (strong and small diameter).  Use a laser to verify the small movement.

1 KWatt (as done by the Chinese) should give you ~0.3 Newtons.  Explore 1.5 to 3 GHz frequencies.
Take a movie and post it in our thread  :)

An interaction with the geomagnetic field might be observed.   Even a small amount of current will cause movement if the pendulum is long.   Twisted DC power leads cancel this out to some extent, but not completely.  There is always some residual current loop.   And any method used to eliminate the resistance to movement from power leads will increase the torque caused by interaction with the geomagnetic field.   This is one possible source of measurement error that is not addressed in the em drive paper, besides the others I mentioned earlier.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 09:22 pm
After I learned to let go of the absolute universality of EEP, I was then able to accept Wheeler-Feynman absorber theory (and all the other theories) as facets of the same interaction, expressed at different levels of interaction.

Thanks Dr. McCulloch for bringing order to the madness via your fresh insight on the true origin of inertial mass. I hope you are correct.

As the great Feynman is quoted, "All mass is interaction."
Wheeler-Feynman absorber theory has no arrow of time: it implies time symmetry.  For QED it has even more problems, that's why Feynman abandoned it for QED (due to the problem of self-interactions). 

Does McCulloch's quantised inertia theory also imply time-symmetry? no arrow of time?  I didn't notice that.

Also, my understanding of McCulloch's theory that it assumes that the inertial mass of an object is caused
by Unruh radiation resulting from its acceleration with respect to surrounding matter.

It modifies the context of the origin of inertial mass to fit the universe.

Said a different way, "The origin of all mass is all interaction."

Not just some interaction. Not just distant matter, and the gravity from it.

Another core tenet is that objects undergoing very very very small acceleration have very very very low inertial mass.

Unruh radiation is a fancy way of saying ALL possible radiation.

OK but I see some very nice things.  The weak force has an arrow of time that breaks time symmetry.  The weak force is associated with radiation.  Unruh is a form of radiation, like Hawkins radiation that is part of quantum gravity.

McCulloch --> local effects + arrow of time / a quantised theory of inertia
Title: Re: EM Drive Developments
Post by: Mulletron on 10/10/2014 09:26 pm
After I learned to let go of the absolute universality of EEP, I was then able to accept Wheeler-Feynman absorber theory (and all the other theories) as facets of the same interaction, expressed at different levels of interaction.

Thanks Dr. McCulloch for bringing order to the madness via your fresh insight on the true origin of inertial mass. I hope you are correct.

As the great Feynman is quoted, "All mass is interaction."
Wheeler-Feynman absorber theory has no arrow of time: it implies time symmetry.  For QED it has even more problems, that's why Feynman abandoned it for QED (due to the problem of self-interactions). 

Does McCulloch's quantised inertia theory also imply time-symmetry? no arrow of time?  I didn't notice that.

Also, my understanding of McCulloch's theory that it assumes that the inertial mass of an object is caused
by Unruh radiation resulting from its acceleration with respect to surrounding matter.

It modifies the context of the origin of inertial mass to fit the universe.

Said a different way, "The origin of all mass is all interaction."

Not just some interaction. Not just distant matter, and the gravity from it.

Another core tenet is that objects undergoing very very very small acceleration have very very very low inertial mass.

Unruh radiation is a fancy way of saying ALL possible radiation.

OK but I see some very nice things.  The weak force has an arrow of time that breaks time symmetry.  The weak force is associated with radiation.  Unruh is a form of radiation, like Hawkins radiation that is part of quantum gravity.

McCulloch --> local effects + arrow of time / a quantised theory of inertia

His theory reconciles QM with GR by bringing precision to GR.

You don't even need to quantize gravity anymore.

You don't need fancy math tricks anymore.

You don't need dark matter anymore.

You can calculate dark energy as vacuum energy correctly now.

The vacuum catastrophe can go away.

A cold inertial particle with NO acceleration is a perfect emitter and absorber.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 09:26 pm
What would be the complications on conducting experiments in my garage?
I would need a copper frustum and optimised dielectric designed by you guys.
RF power source.
Suspend the whole thing from a wire and see if it moves.
Am I missing anything?

Suspend it from the place that will give you the greatest height, as high as possible in a place with no air drafts.  > 20ft high would be nice.  Do you have access to an abandoned elevator shaft?


Use thin piano wire (strong and small diameter).  Use a laser to verify the small movement.

1 KWatt (as done by the Chinese) should give you ~0.3 Newtons.  Explore 1.5 to 3 GHz frequencies.
Take a movie and post it in our thread  :)

An interaction with the geomagnetic field might be observed.   Even a small amount of current will cause movement if the pendulum is long.   Twisted DC power leads cancel this out to some extent, but not completely.  There is always some residual current loop.   And any method used to eliminate the resistance to movement from power leads will increase the torque caused by interaction with the geomagnetic field.   This is one possible source of measurement error that is not addressed in the em drive paper, besides the others I mentioned earlier.

I agree.

What are the other "possible source of measurement error that is not addressed in the em drive paper" you mentioned previously (besides the geomagnetic field) ? Please refresh our minds...
Title: Re: EM Drive Developments
Post by: zen-in on 10/10/2014 09:34 pm
What would be the complications on conducting experiments in my garage?
I would need a copper frustum and optimised dielectric designed by you guys.
RF power source.
Suspend the whole thing from a wire and see if it moves.
Am I missing anything?

Suspend it from the place that will give you the greatest height, as high as possible in a place with no air drafts.  > 20ft high would be nice.  Do you have access to an abandoned elevator shaft?


Use thin piano wire (strong and small diameter).  Use a laser to verify the small movement.

1 KWatt (as done by the Chinese) should give you ~0.3 Newtons.  Explore 1.5 to 3 GHz frequencies.
Take a movie and post it in our thread  :)

An interaction with the geomagnetic field might be observed.   Even a small amount of current will cause movement if the pendulum is long.   Twisted DC power leads cancel this out to some extent, but not completely.  There is always some residual current loop.   And any method used to eliminate the resistance to movement from power leads will increase the torque caused by interaction with the geomagnetic field.   This is one possible source of measurement error that is not addressed in the em drive paper, besides the others I mentioned earlier.

I agree.

What are the other "possible source of measurement error that is not addressed in the em drive paper" you mentioned previously (besides the geomagnetic field) ? Please refresh our minds...

This is from earlier posts:

A previous lurker and a newly minted member here.   I have been following this topic for some time and just want to throw in a few thoughts I have had, for what they are worth.
 1) The MCL amplifier used is a Class AB amp.   The output, unless it has a DC blocking cap inside the amp, will have a DC offset = Vdd/2.   My guess is the amp does not have a DC blocking cap because that would affect the bandwidth and MCL likes to advertise their amplifiers as being broadband.   It is also possible that different load configurations (reflected power) will change the offset.   When a dummy load is used the RF feedline is totally coaxial so no external magnetic effects would be present.   However when the cavity is loaded the internal loop, if there is a DC offset, would act like an electromagnet.   Any DC magnetic field generated in the loop would not be shielded by the metal.   There is no mention of any testing or mitigation of a DC offset from the Class AB amplifier in the paper.   I would not expect the dual directional couplers used between the amplifier and the cavity to have DC blocking caps.
 2)  I also question the RF theory of this device.   It is an untuned cavity with a very high Q ceramic resonator inside.   Almost all the RF power will be in the ceramic, and very little power will be bouncing off the inside Cu walls of the cavity.   The cavity is just a Faraday cage.   Its end caps are single-sided FR4 (fiberglass PCB material).  The S11 plot (voltage reflection coefficient at the input) shows this very well.   Very, very little RF power is reflected back to the input at 1932.6 MHz.   That is to be expected.  Any RF-tight enclosure with the same ceramic resonator inside would produce a similar S11 plot.   There is no mystery about it.   Well, except where does the anomalous force come from?
 

And later:
Quote
In pages 15, 16 of the paper the 16 mm and 12.5 mm loop antenna used to drive the cone-shaped cavity are mentioned.   The wireframe drawings of the cavity also show a loop attached to what looks like an RF connector on the outside of the cone.    The MCL ZHL-100 amplifier is rated at 100 W with a 28 V supply.  Since they are only running it at 17 or 2.6 Watts the DC supply would be much less than 28 V.   So if there was a DC offset coming from the class AB amp that was not blocked there would not be a significant overload of the power supply or amp.   This is just theoretical.   I don't know if the RF amps DC offset is blocked.   Nothing in the paper indicates that it is.   I don't know enough about the Cannae device to know if it uses a loop or a 1/4 λ probe, but all the RF cavity filters I have seen use loops.
Title: Re: EM Drive Developments
Post by: Rodal on 10/10/2014 09:50 pm
....

So the possible measurement error you bring up is:

Possible DC offset coming from the class AB amp that was not blocked. When the cavity is loaded, if there is an unblocked DC offset, the EM drive will act like an electromagnet, and the slowly-varying magnetic field will escape the EM drive's cavity. The slowly-varying magnetic field from the cavity may interact with any combination of the following:

A) the Earth's magnetic field,
B) the magnetic damper used to dampen the inverted torsional pendulum oscillations
C) the magnetic field from the power cable

Did I include everything you brought up as a possible measurement error?
Title: Re: EM Drive Developments
Post by: zen-in on 10/10/2014 10:36 pm
....

So the possible measurement error you bring up is:

Possible DC offset coming from the class AB amp that was not blocked. When the cavity is loaded, if there is an unblocked DC offset, the EM drive will act like an electromagnet, and the slowly-varying magnetic field will escape the EM drive's cavity. The slowly-varying magnetic field from the cavity may interact with any combination of the following:

A) the Earth's magnetic field,
B) the magnetic damper used to dampen the inverted torsional pendulum oscillations
C) the magnetic field from the power cable

Did I include everything you brought up as a possible measurement error?
Yes.  I mention these possible sources of error because there they are not discussed in the paper and when measuring very small forces the geomagnetic field and fields from power cables can produce measurable results.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 12:13 am
....

Here are the reasons why the measurements maybe an experimental artifact, better prioritized and with comments:

Possible DC offset coming from the class AB amp that was not properly blocked. When the cavity is loaded, with an unblocked DC offset, the EM drive will act like an electromagnet, and the slowly-varying magnetic field will escape the EM drive's cavity. The slowly-varying magnetic field from the cavity may interact with any combination of the following:



1) the Earth's magnetic field

Pro:  This is common throughout the Earth: in the USA, UK and China. So it would serve to explain all the experiments, in different continents.

Against:

A) One would expect the alignment with the geomagnetic field to differ with (likely different) experimental setup orientations in the USA, UK and China.  Therefore one would not expect an equation (like Prof. McCulloch's) to universally and comprehensibly explain all these experiments without an obvious bias between the different locations.
 
B) Shawyer's rotational "on air bearing" demonstration had the Shawyer EMDrive smoohtly rotate through many revolutions.  I would not have expected that smooth rotation to be compatible with a magnetic field interaction between the EMDrive and the geomagnetic field.



2) the magnetic field from the power cable

Against:

A) I would expect this to be an issue with external sources of power (NASA Eagleworks) but not when using a battery.
 
B) Shawyer's rotational "on air bearing" demonstration had the Shawyer EMDrive smoohtly rotate through many revolutions.  I would not have expected that smooth rotation to be compatible with a magnetic field interaction between the EMDrive and a stationary power cable.



3) the magnetic damper used to dampen the inverted torsional pendulum oscillations

Against:

A) I would expect this to be an issue only for NASA Eagleworks.  Perhaps with the Chinese University if they also used a magnetic damper (which is unknown).  It doesn't appear that Shawyer used a magnetic damper.
 
B) Shawyer's rotational "on air bearing" demonstration had the Shawyer EMDrive smoohtly rotate through many revolutions.  I would not have expected that smooth rotation to be compatible with a stationary magnetic damper even if Shawyer would have used a magnetic damper (which apparently he did not use).
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/11/2014 12:46 am
Quote
His theory reconciles QM with GR by bringing precision to GR.

You don't even need to quantize gravity anymore.

You don't need fancy math tricks anymore.

You don't need dark matter anymore.

You can calculate dark energy as vacuum energy correctly now.

The vacuum catastrophe can go away.

A cold inertial particle with NO acceleration is a perfect emitter and absorber.

According to my feeble understanding, this means rewriting the physics textbooks. 
Title: Re: EM Drive Developments
Post by: zen-in on 10/11/2014 01:32 am
....

Here are the reasons why the measurements maybe an experimental artifact, better prioritized and with comments:

Possible DC offset coming from the class AB amp that was not properly blocked. When the cavity is loaded, with an unblocked DC offset, the EM drive will act like an electromagnet, and the slowly-varying magnetic field will escape the EM drive's cavity. The slowly-varying magnetic field from the cavity may interact with any combination of the following:



1) the Earth's magnetic field

Pro:  This is common throughout the Earth: in the USA, UK and China. So it would serve to explain all the experiments, in different continents.

Against:

A) One would expect the alignment with the geomagnetic field to differ with (likely different) experimental setup orientations in the USA, UK and China.  Therefore one would not expect an equation (like Prof. McCulloch's) to universally and comprehensibly explain all these experiments without an obvious bias between the different locations.
 
B) Shawyer's rotational "on air bearing" demonstration had the Shawyer EMDrive smoohtly rotate through many revolutions.  I would not have expected that smooth rotation to be compatible with a magnetic field interaction between the EMDrive and the geomagnetic field.



2) the magnetic field from the power cable

Against:

A) I would expect this to be an issue with external sources of power (NASA Eagleworks) but not when using a battery.
 
B) Shawyer's rotational "on air bearing" demonstration had the Shawyer EMDrive smoohtly rotate through many revolutions.  I would not have expected that smooth rotation to be compatible with a magnetic field interaction between the EMDrive and a stationary power cable.



3) the magnetic damper used to dampen the inverted torsional pendulum oscillations

Against:

A) I would expect this to be an issue only for NASA Eagleworks.  Perhaps with the Chinese University if they also used a magnetic damper (which is unknown).  It doesn't appear that Shawyer used a magnetic damper.
 
B) Shawyer's rotational "on air bearing" demonstration had the Shawyer EMDrive smoohtly rotate through many revolutions.  I would not have expected that smooth rotation to be compatible with a stationary magnetic damper even if Shawyer would have used a magnetic damper (which apparently he did not use).

My overall take on this em-drive phenomena and a conservative application of Occam's razor is that Sonny White is a very good experimentalist, and possibly the best of them all.   He has done the most to find and account for any anomalous force and has reduced it to the lowest level.   I am assuming he is privy to many of the details of the other em-drive experiments.   I consider his work to be a good-faith effort to duplicate Sawyer's or the Chinese group's experiment; after all replication is the purpose.   If others have replicated Sawyer's experiment independently, or the Chinese experiment and gotten the same force values, then my views might change.   I mention these possible sources of error as they could apply to the JSC experiments, after reading their paper since I just don't have as many details on the other em-drive experiments.  It is entirely possible that in their thoroughness they did account for these effects, but considering them too trivial to mention in their paper.    I remain an unbeliever in this em-drive.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 01:54 am

My overall take on this em-drive phenomena and a conservative application of Occam's razor is that Sonny White is a very good experimentalist, and possibly the best of them all.   He has done the most to find and account for any anomalous force and has reduced it to the lowest level.   I am assuming he is privy to many of the details of the other em-drive experiments.   I consider his work to be a good-faith effort to duplicate Sawyer's or the Chinese group's experiment; after all replication is the purpose.   If others have replicated Sawyer's experiment independently, or the Chinese experiment and gotten the same force values, then my views might change.   I mention these possible sources of error as they could apply to the JSC experiments, after reading their paper since I just don't have as many details on the other em-drive experiments.  It is entirely possible that in their thoroughness they did account for these effects, but considering them too trivial to mention in their paper.    I remain an unbeliever in this em-drive.

These are the Chinese papers:

http://www.emdrive.com/NWPU2010translation.pdf
http://www.emdrive.com/yang-juan-paper-2012.pdf

and this is the best (in my opinion) of the Shawyer's papers:

http://www.emdrive.com/IAC-08-C4-4-7.pdf

I look forward to your reviewing the above papers with your critical eye, when you have the time, as I would appreciate hearing any potential problems you uncover with their experimental setup. 
 
Title: Re: EM Drive Developments
Post by: zen-in on 10/11/2014 04:51 am

My overall take on this em-drive phenomena and a conservative application of Occam's razor is that Sonny White is a very good experimentalist, and possibly the best of them all.   He has done the most to find and account for any anomalous force and has reduced it to the lowest level.   I am assuming he is privy to many of the details of the other em-drive experiments.   I consider his work to be a good-faith effort to duplicate Sawyer's or the Chinese group's experiment; after all replication is the purpose.   If others have replicated Sawyer's experiment independently, or the Chinese experiment and gotten the same force values, then my views might change.   I mention these possible sources of error as they could apply to the JSC experiments, after reading their paper since I just don't have as many details on the other em-drive experiments.  It is entirely possible that in their thoroughness they did account for these effects, but considering them too trivial to mention in their paper.    I remain an unbeliever in this em-drive.

These are the Chinese papers:

http://www.emdrive.com/NWPU2010translation.pdf
http://www.emdrive.com/yang-juan-paper-2012.pdf

and this is the best (in my opinion) of the Shawyer's papers:

http://www.emdrive.com/IAC-08-C4-4-7.pdf

I look forward to your reviewing the above papers with your critical eye, when you have the time, as I would appreciate hearing any potential problems you uncover with their experimental setup. 
 
There isn't enough information about their experimental setup in Yang et al paper to critique it.   And not enough for anyone to replicate their experiment. 

Shawyer's has a little more information.  One thing that does stand out is the large radiator and the much larger power dissipation of his experiment.   More pictures of his apparatus, along with descriptions of how it was changed for different tests (forward, reverse, up, down) would help.   

There are so many different ways that a small force can be produced when so much power is being dissipated.   For example if that whole copper cone was heating the surrounding air there would be a net thrust generated, because of the angle of the cone, similar to what turns the paddle wheels of a classical radiometer.   

Shawyer's graph 10 shows a slow increase in thrust during which time he states the magnetron is unlocked and the device is not accelerating until 130 Sec.  However velocity is indicated from 75 Sec on.     Maybe those first 75 130 Sec before any thrust is indicated is how long it takes for the cone to heat up enough to start pushing air and the time from 75 - 130 Sec is when the temperature is continuing to rise.  The strange shape of the velocity curve does look temperature related.   

At 75 Sec. the frequency is within .04% of the stated cavity natural frequency and the power is maximum.  The Q can't be that low .04% from the peak.   And at 200 Sec the power is switched off yet the device's velocity continues to increase.   That also looks like a thermal effect, ie: it takes several Sec. for the cone to cool down enough that it is no longer pushing air away from it.   Shawyer says this continued acceleration is due to the "slosh effects of 5 kg of coolant".  Did the coolant line spring a leak?  Or does the closed loop coolant system also push against the inertia of the cosmos?

There are so many possible explanations for the small thrust Shawyer's em-drive produces given the high power and complexity of the apparatus.   The JSC group built a much simpler low power test apparatus and have almost reduced the anomalous force to zero.  Maybe their force is also due to heat radiating from the cone and pushing air.   There may be a much shorter thermal time constant with their apparatus if the cone is lightweight Copper GR4 (PCB material).  The endcaps of the JSC em-drive do not have exposed Copper.   The material on the outside of the endcaps looks like FR4, which is an insulator.   So  the cone section would be heating air much more than the end caps.   Another reason to test it in a vacuum.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 07:36 am
Quote
His theory reconciles QM with GR by bringing precision to GR.

You don't even need to quantize gravity anymore.

You don't need fancy math tricks anymore.

You don't need dark matter anymore.

You can calculate dark energy as vacuum energy correctly now.

The vacuum catastrophe can go away.

A cold inertial particle with NO acceleration is a perfect emitter and absorber.

According to my feeble understanding, this means rewriting the physics textbooks.

Yeah, given his notions about the effects of very very low accelerations which happen at the edges of galaxies and beyond; this serves to bring the uncertainty principle to the macro world, in the context of GR. This isn't a stretch in my view, because if you view EVERYTHING as a particle and a wave, this makes sense. You have to treat the the universe as a particle, and we're inside of that particle.

So if you encounter an object out there in deep space with no discernible acceleration, but you know that no acceleration is impossible. It must have an uncertain acceleration.

No more dichotomy is needed between QM and GR.

This isn't much of a leap. Black holes are already characterized as particles. They have mass, charge, and angular momentum.

http://www.youtube.com/watch?v=VivF5R4IFQ4

Concentric spheres my friends. Gravity is common to all of them. Gravity is emergent as a product of all interactions.

The only question is, what layer of the onion are we at? That probably doesn't have meaning in the context of infinity.

It all makes sense this way.

Treat EMdrive as a particle inside a universe, and treat the inside of EMdrive as a universe (where ALL MASS is the result of ALL interaction, suddenly becomes, ALL MASS is the result of MOST interaction), because some interactions were blocked by its boundaries....

amazing things happen.

You have to ask yourself:

If all mass is all interaction. What happens to that mass if you redirect or block (by geometry taking advantage of casimir effects or meta materials) some of those interactions?

Inertial mass isn't tied to just gravitational interaction. Rather it is tied to ALL interactions; happening over time.

You get less inertial mass.

Title: Re: EM Drive Developments
Post by: RotoSequence on 10/11/2014 08:58 am
I hate to be a wet blanket, but until there's experimental evidence to support the idea, it's only a hypothesis - a far cry from the time to rewrite physics texts! ;)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 09:14 am
I hate to be a wet blanket, but until there's experimental evidence to support the idea, it's only a hypothesis - a far cry from the time to rewrite physics texts! ;)

http://physics.aps.org/story/v12/st14
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/11/2014 09:16 am
I hate to be a wet blanket, but until there's experimental evidence to support the idea, it's only a hypothesis - a far cry from the time to rewrite physics texts! ;)

http://physics.aps.org/story/v12/st14

Facts that happen to fit the theory help, but rigorous testing of the theory's predictions are needed before they can be accepted as something more than a theory.
Title: Re: EM Drive Developments
Post by: Star One on 10/11/2014 10:22 am

I hate to be a wet blanket, but until there's experimental evidence to support the idea, it's only a hypothesis - a far cry from the time to rewrite physics texts! ;)

http://physics.aps.org/story/v12/st14

Facts that happen to fit the theory help, but rigorous testing of the theory's predictions are needed before they can be accepted as something more than a theory.

Which is what's happening.:)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 10:36 am
I designed 2 ways to test modified inertia.
1. Take a test chamber and cover it with blocking meta materials. See if inertial mass of particles inside changes compared to outside.

2. Cover half sphere with metamaterial, see if it is easier to move one way vs other against gravity.

Edit:

3. Assuming that dielectric thrust holds true first, a sphere vs cone shaped emdrive should thrust differently, everything else kept the same. (Hard to do)

IMHO, in the cone shaped cavity, emdrive will work with the dielectric via the theoretical QV thrust mechanism, and without the dielectric, by uneven momentum transfer across the walls of the cavity, resulting in uneven heating, the imbalance causing movement. Both ways are due to conservation of momentum.

So dielectric thrust only, in any shaped device=some thrust
Cone shape with no dielectric=some thrust
Cone shape and dielectric=most thrust

They need to run the test campaigns for a long time, to see if there is any thrust from having no dielectric in the cavity. It is a question of 0-60 speed, more or less ponies as they say.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 01:43 pm

I hate to be a wet blanket, but until there's experimental evidence to support the idea, it's only a hypothesis - a far cry from the time to rewrite physics texts! ;)

http://physics.aps.org/story/v12/st14

Facts that happen to fit the theory help, but rigorous testing of the theory's predictions are needed before they can be accepted as something more than a theory.

Which is what's happening.:)

Like I said, do the maths and see if our crazy ideas might work.

If the maths work,
build a better one.
Test it.

Classic science. Some crazy theorist has an idea, works it out in math, gives it to an engineer, the engineer says heck no this is stupid, then builds it as best as he can. The experimentalist make sense of it, then feed it back to the crazy theorist.

Rinse, repeat.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 01:51 pm

Classic science. Some crazy theorist has an idea, works it out in math, gives it to an engineer, the engineer says heck no this is stupid, then builds it as best as he can. The experimentalist make sense of it, then feed it back to the crazy theorist.

Rinse, repeat.

http://www.uni-bielefeld.de/(en)/ZIF/FG/2012Quantumscience/abstract/02-27-vortrag/Vortrag-Satz.pdf

thermal hadron production in e+e− (positron electron) annihilation, including strangeness suppression, is reproduced parameter-free as Hawking-Unruh radiation of QCD


measurements cannot tell if the equilibrium was reached by thermal evolution or by throwing dice:

⇒ Ergodic Equivalence Principle ⇐

gravitation ∼ acceleration

kinetic ∼ stochastic

equivalence of kinetic vs. stochastic equilibration
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 02:07 pm

Classic science. Some crazy theorist has an idea, works it out in math, gives it to an engineer, the engineer says heck no this is stupid, then builds it as best as he can. The experimentalist make sense of it, then feed it back to the crazy theorist.

Rinse, repeat.

http://www.uni-bielefeld.de/(en)/ZIF/FG/2012Quantumscience/abstract/02-27-vortrag/Vortrag-Satz.pdf

thermal hadron production in e+e− (positron electron) annihilation, including strangeness suppression, is reproduced parameter-free as Hawking-Unruh radiation of QCD


measurements cannot tell if the equilibrium was reached by thermal evolution or by throwing dice:

⇒ Ergodic Equivalence Principle ⇐

gravitation ∼ acceleration

kinetic ∼ stochastic

equivalence of kinetic vs. stochastic equilibration

Russian folklore. So basically a QCD thrust vector aka work path.

Good find!
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 02:29 pm
(http://upload.wikimedia.org/wikipedia/commons/3/3c/Schwinger.jpg)
(http://i.dailymail.co.uk/i/pix/2013/07/04/article-2355621-00AA40DD1000044C-24_634x445.jpg)
(http://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Wgunruh_phys407.jpg/290px-Wgunruh_phys407.jpg)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 02:37 pm
So let me get this straight...

Collect underpants
?
Profit

http://www.youtube.com/watch?v=tO5sxLapAts

An interesting design note to remember is that you can't forget about doppler shift inside the cavity as you accelerate. You either gotta shorten the cavity or raise the frequency of operation, or something else....I'm thinking a feedback loop from an accelerometer to your magnetron, used to vary the operation frequency depending on if it senses positive or negative accelerations. To keep the ride smooth.

On the flipside, you can intentionally detune the cavity to provide variable thrust, or braking.

He's right you know:
http://www.emdrive.com/IAC13paper17254.v2.pdf
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 02:46 pm
So let me get this straight...
...
?
...


The big question mark is whether the microwave (~2GHz) EmDrive [copper ????] flat walls can make a horizon.

Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation and therefore that the Unruh waves are affected by the [copper ????] flat wall because they are partly ElectroMagnetic waves and the electrons in the [copper ????] flat walls move to cancel the field, so the Unruh wave patterns close at the [copper ????] flat walls just as at the Hubble horizon ?

Four questions really:

1) Is the NASA Eagleworks truncated cone a complete, closed, Faraday cage, including both flat end surfaces? (are the end surfaces also made of copper?)

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

3) Is it correct to assume that the Unruh wave patterns close at the [copper ????] flat walls just as at the Hubble horizon ?

4) Is McCulloch's MiHsC theory correct that inertial mass is caused by Unruh radiation, and so it is affected by the Hubble horizon since Unruh waves must fit exactly within this horizon?.

(In MiHsC the inertial mass (mi) depends on the Unruh radiation wavelength and the Hubble distance as follows:
 mi=m(1-L/4T)
 m = unmodified mass
 L = Unruh wavelength dependent on acceleration
 T = Hubble horizon distance)

Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 02:58 pm
Again, what are the small and large flat walls of the NASA Eagleworks truncated cone made out of?
All we can see is that they are covered by PCB material.  Is there copper behind them?
Or is it just PCB material ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 03:01 pm
Shawyer drive

(http://www.dvice.com/sites/dvice/files/styles/blog_post_media/public/emdrive.jpg?itok=NQ-5avZ_)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 03:25 pm
So let me get this straight...
...
?
...


The big question mark is whether the microwave (~2GHz) EmDrive [copper ????] flat walls can make a horizon.

Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation and therefore that the Unruh waves are affected by the [copper ????] flat wall because they are partly ElectroMagnetic waves and the electrons in the [copper ????] flat walls move to cancel the field, so the Unruh wave patterns close at the [copper ????] flat walls just as at the Hubble horizon ?

Four questions really:

1) Is the NASA Eagleworks truncated cone a complete, closed, Faraday cage, including both flat end surfaces? (are the end surfaces also made of copper?)

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

3) Is it correct to assume that the Unruh wave patterns close at the [copper ????] flat walls just as at the Hubble horizon ?

4) Is McCulloch's MiHsC theory correct that inertial mass is caused by Unruh radiation, and so it is affected by the Hubble horizon since Unruh waves must fit exactly within this horizon?. (In MiHsC the inertial mass (mi) depends on the Unruh radiation wavelength and the Hubble distance as follows:
 mi=m(1-L/4T)
where m is the unmodified mass, L is the Unruh wavelength determined by the acceleration, and T is the Hubble distance)


Unruh waves are all around you right now. They are not apparent to you until you accelerate and things start heating up (unruh radiation). In our everyday experience, all you can do to see unruh waves in action is measure their effect via the casimir effect.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 03:29 pm
Unruh waves are all around you right now. They are not apparent to you until you accelerate and things start heating up. In our everyday experience, all you can do to see unruh waves in action is measure their effect via the casimir effect.
The existence of Unruh radiation is controversial. The skeptics accept that an accelerating object thermalises at the Unruh temperature, but they do not believe that this leads to the emission of particles, arguing that the emission and absorption rates of the accelerating particle are balanced.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 03:31 pm
Unruh waves are all around you right now. They are not apparent to you until you accelerate and things start heating up. In our everyday experience, all you can do to see unruh waves in action is measure their effect via the casimir effect.
The existence of Unruh radiation is controversial. The skeptics accept that an accelerating object thermalises at the Unruh temperature, but they do not believe that this leads to the emission of photons, arguing that the emission and absorption rates of the accelerating particle are balanced.
I liken it to Hawking radiation. Hawking radiation is also the result of a large acceleration. The acceleration across a black hole's event horizon, which pulls apart particle pairs, resulting in Hawking radiation. Pretty much the same thing, different ways of looking at it.

Besides, we're not trying to go ludicrous speed here. Just a wiggle on a test bench is enough for me.

http://www.youtube.com/watch?v=ygE01sOhzz0
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 03:34 pm
Unruh waves are all around you right now. They are not apparent to you until you accelerate and things start heating up. In our everyday experience, all you can do to see unruh waves in action is measure their effect via the casimir effect.
The existence of Unruh radiation is controversial. The skeptics accept that an accelerating object thermalises at the Unruh temperature, but they do not believe that this leads to the emission of photons, arguing that the emission and absorption rates of the accelerating particle are balanced.
I liken it to Hawking radiation. Hawking radiation is also the result of a large acceleration. The acceleration across a black hole's event horizon, which pulls apart particle pairs, resulting in Hawking radiation. Pretty much the same thing, different ways of looking at it.
Hawking radiation is also controversial. It leads to information problems.  To adress the information apparent "loss" different solutions have been proposed.  There is no consensus.  Under experimentally achievable conditions for gravitational systems Hawking radiation is too small to be observed directly.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 03:37 pm
So let me get this straight...
...
?
...


The big question mark is whether the microwave (~2GHz) EmDrive [copper ????] flat walls can make a horizon.

Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation and therefore that the Unruh waves are affected by the [copper ????] flat wall because they are partly ElectroMagnetic waves and the electrons in the [copper ????] flat walls move to cancel the field, so the Unruh wave patterns close at the [copper ????] flat walls just as at the Hubble horizon ?

Four questions really:

1) Is the NASA Eagleworks truncated cone a complete, closed, Faraday cage, including both flat end surfaces? (are the end surfaces also made of copper?)

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

3) Is it correct to assume that the Unruh wave patterns close at the [copper ????] flat walls just as at the Hubble horizon ?

4) Is McCulloch's MiHsC theory correct that inertial mass is caused by Unruh radiation, and so it is affected by the Hubble horizon since Unruh waves must fit exactly within this horizon?. (In MiHsC the inertial mass (mi) depends on the Unruh radiation wavelength and the Hubble distance as follows:
 mi=m(1-L/4T)
where m is the unmodified mass, L is the Unruh wavelength determined by the acceleration, and T is the Hubble distance)


Unruh waves are all around you right now. They are not apparent to you until you accelerate and things start heating up (unruh radiation). In our everyday experience, all you can do to see unruh waves in action is measure their effect via the casimir effect.

Can you answer the first three questions I posed above, starting by the first one?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 03:39 pm
Unruh waves are all around you right now. They are not apparent to you until you accelerate and things start heating up. In our everyday experience, all you can do to see unruh waves in action is measure their effect via the casimir effect.
The existence of Unruh radiation is controversial. The skeptics accept that an accelerating object thermalises at the Unruh temperature, but they do not believe that this leads to the emission of photons, arguing that the emission and absorption rates of the accelerating particle are balanced.
I liken it to Hawking radiation. Hawking radiation is also the result of a large acceleration. The acceleration across a black hole's event horizon, which pulls apart particle pairs, resulting in Hawking radiation. Pretty much the same thing, different ways of looking at it.
Hawking radiation is also controversial. It leads to information problems.  To adress the information apparent "loss" different solutions have been proposed.  There is no consensus.  Under experimentally achievable conditions for gravitational systems Hawking radiation is too small to be observed directly.

Hawking radiation is not just where particle pairs are pulled apart. It is also the mechanism for which information is conserved. It isn't a cause of information problems. A black hole slowly evaporates and returns that information back to the universe.

http://www.youtube.com/watch?v=VhHE86d-Th8
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 03:50 pm
...

Hawking radiation is not just where particle pairs are pulled apart. It is also the mechanism for which information is conserved. It isn't a cause of information problems. A black hole slowly evaporates and returns that information back to the universe.
...

Rather than arguing about what Hawking radiation encompasses, and whether there is a Hawking radiation paradox http://en.wikipedia.org/wiki/Black_hole_information_paradox  (certainly there is no consensus) and such esoteric topics, why don't we concentrate on the EM drive?

I propose we should strive to answer the questions I posed, starting by the first simple question: is the NASA Eagleworks drive a closed Faraday cage?  are the flat ends indeed made out of copper?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 03:54 pm
...

Hawking radiation is not just where particle pairs are pulled apart. It is also the mechanism for which information is conserved. It isn't a cause of information problems. A black hole slowly evaporates and returns that information back to the universe.
...

Rather than arguing about what Hawking radiation encompasses, and whether there is a Hawking radiation paradox http://en.wikipedia.org/wiki/Black_hole_information_paradox  (certainly there is no consensus) and such esoteric topics, why don't we concentrate on the EM drive?

I propose we should strive to answer the questions I posed, starting by the first simple question: is the NASA Eagleworks drive a closed Faraday cage?  are the flat ends indeed made out of copper?

By every method I use, it appears to be copper all around. Shawyer's design is copper. Nasa tested Shawyer's design.

Information entropy and casual horizons do apply to emdrive. Since the Casimir effect is confirmed, I don't tend to question Unruh waves. Since an object approaching C gets baked by radiation, I don't tend to question Unruh Radiation.

That gray stuff over the large end cap is a cover used for something. I don't know what for.

At emdrive.com, Shawyer says it is an enclosed cavity. The nature of it being an enclosed cavity is why it is controversial. So I say we can keep operating as if it is enclosed.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 04:00 pm
...

Hawking radiation is not just where particle pairs are pulled apart. It is also the mechanism for which information is conserved. It isn't a cause of information problems. A black hole slowly evaporates and returns that information back to the universe.
...

Rather than arguing about what Hawking radiation encompasses, and whether there is a Hawking radiation paradox http://en.wikipedia.org/wiki/Black_hole_information_paradox  (certainly there is no consensus) and such esoteric topics, why don't we concentrate on the EM drive?

I propose we should strive to answer the questions I posed, starting by the first simple question: is the NASA Eagleworks drive a closed Faraday cage?  are the flat ends indeed made out of copper?

By every method I use, it appears to be copper all around. Shawyer's design is copper. Nasa tested Shawyer's design.

Information entropy and casual horizons do apply to emdrive. Since the Casimir effect is confirmed. I don't tend to question Unruh waves. Since an object approaching C gets baked by radiation, I don't tend to question Unruh Radiation.

That gray stuff over the large end cap is a cover used for something. I don't know what for.

At emdrive.com, Shawyer says it is an enclosed cavity. The nature of it being an enclosed cavity is why it is controversial. So I say we can keep operating as if it is enclosed.
Thank you.  That's progress.
Now to the 2nd question:

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

Can we at least  "back of the envelope" calculate what are the accelerations involved ?  (never mind whether they are large enough)

What is accelerating? Why is it accelerating? When is it accelerating? What is the acceleration?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 04:09 pm
...

Hawking radiation is not just where particle pairs are pulled apart. It is also the mechanism for which information is conserved. It isn't a cause of information problems. A black hole slowly evaporates and returns that information back to the universe.
...

Rather than arguing about what Hawking radiation encompasses, and whether there is a Hawking radiation paradox http://en.wikipedia.org/wiki/Black_hole_information_paradox  (certainly there is no consensus) and such esoteric topics, why don't we concentrate on the EM drive?

I propose we should strive to answer the questions I posed, starting by the first simple question: is the NASA Eagleworks drive a closed Faraday cage?  are the flat ends indeed made out of copper?

By every method I use, it appears to be copper all around. Shawyer's design is copper. Nasa tested Shawyer's design.

Information entropy and casual horizons do apply to emdrive. Since the Casimir effect is confirmed. I don't tend to question Unruh waves. Since an object approaching C gets baked by radiation, I don't tend to question Unruh Radiation.

That gray stuff over the large end cap is a cover used for something. I don't know what for.

At emdrive.com, Shawyer says it is an enclosed cavity. The nature of it being an enclosed cavity is why it is controversial. So I say we can keep operating as if it is enclosed.
Thank you.  That's progress.
Now to the 2nd question:

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

Can we at least  "back of the envelope" calculate what are the accelerations involved ?  (never mind whether they are large enough)

What is accelerating? Why is it accelerating? When is it accelerating? What is the acceleration?


No this doesn't apply to electromagnetic radiation itself. It is already going the speed of light.

No, you just confused the heck out of me. Radiation doesn't experience Unruh radiation. It is radiation.

Besides, Unruh waves are important here. Not Unruh radiation.

Just keep in mind, for clarity, the Temperate of the background QV is non zero. That is the Unruh waves. All possible waves at their ground state randomly happening all at once. Noise. The QV. Some fit, some don't and it depends on how close two things are together, how far they are from the Hubble Horizon, and how fast they are going, and their shape.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 04:24 pm
...

Hawking radiation is not just where particle pairs are pulled apart. It is also the mechanism for which information is conserved. It isn't a cause of information problems. A black hole slowly evaporates and returns that information back to the universe.
...

Rather than arguing about what Hawking radiation encompasses, and whether there is a Hawking radiation paradox http://en.wikipedia.org/wiki/Black_hole_information_paradox  (certainly there is no consensus) and such esoteric topics, why don't we concentrate on the EM drive?

I propose we should strive to answer the questions I posed, starting by the first simple question: is the NASA Eagleworks drive a closed Faraday cage?  are the flat ends indeed made out of copper?

By every method I use, it appears to be copper all around. Shawyer's design is copper. Nasa tested Shawyer's design.

Information entropy and casual horizons do apply to emdrive. Since the Casimir effect is confirmed. I don't tend to question Unruh waves. Since an object approaching C gets baked by radiation, I don't tend to question Unruh Radiation.

That gray stuff over the large end cap is a cover used for something. I don't know what for.

At emdrive.com, Shawyer says it is an enclosed cavity. The nature of it being an enclosed cavity is why it is controversial. So I say we can keep operating as if it is enclosed.
Thank you.  That's progress.
Now to the 2nd question:

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

Can we at least  "back of the envelope" calculate what are the accelerations involved ?  (never mind whether they are large enough)

What is accelerating? Why is it accelerating? When is it accelerating? What is the acceleration?


No this doesn't apply to electromagnetic radiation itself. It is already going the speed of light.

No, you just confused the heck out of me. Radiation doesn't experience Unruh radiation. It is radiation.

Quoting Prof. McCulloc:  << but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field,>>

The acceleration is the "a" in the formula you (at least momentarily) posted.

Again I ask you:

What is accelerating?   <<huge accelerations (as Prof. McCulloc assumes for the light/electrons in the EmDrive) >> [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  ]
Where is it accelerating?
Why is it accelerating?
When is it accelerating?
What is the acceleration?

Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 04:29 pm
...

Hawking radiation is not just where particle pairs are pulled apart. It is also the mechanism for which information is conserved. It isn't a cause of information problems. A black hole slowly evaporates and returns that information back to the universe.
...

Rather than arguing about what Hawking radiation encompasses, and whether there is a Hawking radiation paradox http://en.wikipedia.org/wiki/Black_hole_information_paradox  (certainly there is no consensus) and such esoteric topics, why don't we concentrate on the EM drive?

I propose we should strive to answer the questions I posed, starting by the first simple question: is the NASA Eagleworks drive a closed Faraday cage?  are the flat ends indeed made out of copper?

By every method I use, it appears to be copper all around. Shawyer's design is copper. Nasa tested Shawyer's design.

Information entropy and casual horizons do apply to emdrive. Since the Casimir effect is confirmed. I don't tend to question Unruh waves. Since an object approaching C gets baked by radiation, I don't tend to question Unruh Radiation.

That gray stuff over the large end cap is a cover used for something. I don't know what for.

At emdrive.com, Shawyer says it is an enclosed cavity. The nature of it being an enclosed cavity is why it is controversial. So I say we can keep operating as if it is enclosed.
Thank you.  That's progress.
Now to the 2nd question:

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

Can we at least  "back of the envelope" calculate what are the accelerations involved ?  (never mind whether they are large enough)

What is accelerating? Why is it accelerating? When is it accelerating? What is the acceleration?


No this doesn't apply to electromagnetic radiation itself. It is already going the speed of light.

No, you just confused the heck out of me. Radiation doesn't experience Unruh radiation. It is radiation.

Quoting Prof. McCulloc:  << but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field,>>

The acceleration is the "a" in the formula you (at least momentarily) posted.

Again I ask you:

What is accelerating?   <<huge accelerations (as Prof. McCulloc assumes for the light/electrons in the EmDrive) >> [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  ]
Where is it accelerating?
Why is it accelerating?
When is it accelerating?
What is the acceleration?

The emdrive itself accelerating with respect to the universe or any observer.

Inside, the photons with respect to their emitter and the cavity walls.

A photon has no mass first, just momentum; secondly, it is already going C. There is no more to accelerate. It doesn't experience Unruh Radiation. It is radiation.
Title: Re: EM Drive Developments
Post by: aero on 10/11/2014 04:36 pm
The thing that is accelerating is the electric skin current, the electrons in the walls.

I don't have a clue about how far they move per cycle. Probably an AC current with some amplitude.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 04:39 pm
...

Hawking radiation is not just where particle pairs are pulled apart. It is also the mechanism for which information is conserved. It isn't a cause of information problems. A black hole slowly evaporates and returns that information back to the universe.
...

Rather than arguing about what Hawking radiation encompasses, and whether there is a Hawking radiation paradox http://en.wikipedia.org/wiki/Black_hole_information_paradox  (certainly there is no consensus) and such esoteric topics, why don't we concentrate on the EM drive?

I propose we should strive to answer the questions I posed, starting by the first simple question: is the NASA Eagleworks drive a closed Faraday cage?  are the flat ends indeed made out of copper?

By every method I use, it appears to be copper all around. Shawyer's design is copper. Nasa tested Shawyer's design.

Information entropy and casual horizons do apply to emdrive. Since the Casimir effect is confirmed. I don't tend to question Unruh waves. Since an object approaching C gets baked by radiation, I don't tend to question Unruh Radiation.

That gray stuff over the large end cap is a cover used for something. I don't know what for.

At emdrive.com, Shawyer says it is an enclosed cavity. The nature of it being an enclosed cavity is why it is controversial. So I say we can keep operating as if it is enclosed.
Thank you.  That's progress.
Now to the 2nd question:

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

Can we at least  "back of the envelope" calculate what are the accelerations involved ?  (never mind whether they are large enough)

What is accelerating? Why is it accelerating? When is it accelerating? What is the acceleration?


No this doesn't apply to electromagnetic radiation itself. It is already going the speed of light.

No, you just confused the heck out of me. Radiation doesn't experience Unruh radiation. It is radiation.

Quoting Prof. McCulloc:  << but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field,>>

The acceleration is the "a" in the formula you (at least momentarily) posted.

Again I ask you:

What is accelerating?   <<huge accelerations (as Prof. McCulloc assumes for the light/electrons in the EmDrive) >> [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  ]
Where is it accelerating?
Why is it accelerating?
When is it accelerating?
What is the acceleration?

The emdrive itself accelerating with respect to the universe or any observer.

Inside, the photons with respect to their emitter and the cavity walls.

A photon has no mass first, just momentum; secondly, it is already going C. There is no more to accelerate. It doesn't experience Unruh Radiation. It is radiation.

Please read what Prof. McCulloc wrote in his blog, including <<a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, >>

The acceleration of the EM drive center of mass is completely and utterly insignificant.  What Prof. McCulloc is considering is the acceleration of the photons/electrons.

One really needs to understand the following:

What is accelerating?   <<huge accelerations (as Prof. McCulloc assumes for the light/electrons in the EmDrive) >> [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  ]
Where is it accelerating?
Why is it accelerating?
When is it accelerating?
What is the acceleration?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 04:51 pm
...

Hawking radiation is not just where particle pairs are pulled apart. It is also the mechanism for which information is conserved. It isn't a cause of information problems. A black hole slowly evaporates and returns that information back to the universe.
...

Rather than arguing about what Hawking radiation encompasses, and whether there is a Hawking radiation paradox http://en.wikipedia.org/wiki/Black_hole_information_paradox  (certainly there is no consensus) and such esoteric topics, why don't we concentrate on the EM drive?

I propose we should strive to answer the questions I posed, starting by the first simple question: is the NASA Eagleworks drive a closed Faraday cage?  are the flat ends indeed made out of copper?

By every method I use, it appears to be copper all around. Shawyer's design is copper. Nasa tested Shawyer's design.

Information entropy and casual horizons do apply to emdrive. Since the Casimir effect is confirmed. I don't tend to question Unruh waves. Since an object approaching C gets baked by radiation, I don't tend to question Unruh Radiation.

That gray stuff over the large end cap is a cover used for something. I don't know what for.

At emdrive.com, Shawyer says it is an enclosed cavity. The nature of it being an enclosed cavity is why it is controversial. So I say we can keep operating as if it is enclosed.
Thank you.  That's progress.
Now to the 2nd question:

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

Can we at least  "back of the envelope" calculate what are the accelerations involved ?  (never mind whether they are large enough)

What is accelerating? Why is it accelerating? When is it accelerating? What is the acceleration?


No this doesn't apply to electromagnetic radiation itself. It is already going the speed of light.

No, you just confused the heck out of me. Radiation doesn't experience Unruh radiation. It is radiation.

Quoting Prof. McCulloc:  << but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field,>>

The acceleration is the "a" in the formula you (at least momentarily) posted.

Again I ask you:

What is accelerating?   <<huge accelerations (as Prof. McCulloc assumes for the light/electrons in the EmDrive) >> [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  ]
Where is it accelerating?
Why is it accelerating?
When is it accelerating?
What is the acceleration?

The emdrive itself accelerating with respect to the universe or any observer.

Inside, the photons with respect to their emitter and the cavity walls.

A photon has no mass first, just momentum; secondly, it is already going C. There is no more to accelerate. It doesn't experience Unruh Radiation. It is radiation.

Please read what Prof. McCulloc wrote in his blog, including <<a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, >>

The acceleration of the EM drive center of mass is completely and utterly insignificant.  What Prof. McCulloc is considering is the acceleration of the photons/electrons.

One really needs to understand the following:

What is accelerating?   <<huge accelerations (as Prof. McCulloc assumes for the light/electrons in the EmDrive) >> [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  ]
Where is it accelerating?
Why is it accelerating?
When is it accelerating?
What is the acceleration?

"OK. This is why I'm thinking the EmDrive walls might make a horizon: MiHsC assumes that inertia is caused by Unruh waves and the Hubble horizon is a boundary for information so all patterns within the cosmos must close there otherwise they let us deduce what lies beyond (this looks like a Hubble-scale Casimir effect) this includes the Unruh waves, so it affects inertia. Now, for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves and the electrons in the copper move to cancel the field, so the Unruh wave patterns have to close at the wall just as at the Hubble horizon (but for a different reason), so we have a mini-MiHsC going on. In both cosmic & mini cases it seems to explain anomalies."

Making sense of this:

Outside, the hubble scale casimir effect is very small, meaning inertia is modified very little.
Accelerate the thing to very high speeds, you get a big difference.

Inside, the walls of the cavity act as an event horizon, lowering the inertial mass of the particle a little bit.
A very slightly lower mass. Not negative mass. Just less inertial mass.

Treat the inside of the cavity as the space between two parallel casimir plates.  Only fully enclosed. Then you'll get it. Less Unruh waves fit. Less energy in the system. Lower temperature in the device. Less interactions with the outside world and universe. Lower accelerations. Lower inertia.

The hubble scale of the inside of the cavity is its walls.

Here on earth, the effects are very very very small. Accelerate the thing a lot and they get big.

Read my summary.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 05:11 pm
Sure could use some help testing these ideas with some math and ridicule.
Title: Re: EM Drive Developments
Post by: aero on 10/11/2014 05:12 pm
Quote
What is accelerating?   <<huge accelerations (as Prof. McCulloc assumes for the light/electrons in the EmDrive) >> [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  ]
Where is it accelerating?
Why is it accelerating?
When is it accelerating?
What is the acceleration?

Why is this a mystery? See my earlier post. The electrons within the cavity walls are accelerating in response to the RF wave. It is an AC acceleration of some amplitude at the frequency of the RF waves. Guess the amplitude of the electron oscillation, which is limited by the cavity dimensions and converted to heat by resistance. With the amplitude, then isn't the acceleration just the second derivative? What amplitude is needed to make the theory hold water?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 05:17 pm
Quote
What is accelerating?   <<huge accelerations (as Prof. McCulloc assumes for the light/electrons in the EmDrive) >> [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  ]
Where is it accelerating?
Why is it accelerating?
When is it accelerating?
What is the acceleration?

Why is this a mystery? See my earlier post. The electrons within the cavity walls are accelerating in response to the RF wave. It is an AC acceleration of some amplitude at the frequency of the RF waves. Guess the amplitude of the electron oscillation, which is limited by the cavity dimensions and converted to heat by resistance. With the amplitude, then isn't the acceleration just the second derivative? What amplitude is needed to make the theory hold water?

Amen. The rf field excites the particles in the walls. They get absorbed eventually like this and turn to heat. This is just a classic boundary condition. In addition to that, the material of the walls has a plasma frequency which sets its band gap. Frequencies that won't pass through. McCulloch was referring to the fields getting absorbed by the walls, setting the boundary conditions inside. Same as us.

Can we move on to the hard stuff now?
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 05:22 pm
The field at any location outside the copper cavity includes the field contributed by internal charges. However, it looks as though the copper prevents the field from getting out, because the internal charges “polarize” the copper by shifting the mobile electrons in the metal, and the polarized copper contributes an additional electric field outside the container that is equal in magnitude but opposite in direction to the field contributed by the internal charges. The effect is indeed as though the copper “shielded” the copper cavity.

As the electric field contacts the copper, it accelerates the electrons (it accelerates the electrons much more than the protons, due to their very low mass). These accelerated electrons radiate electromagnetic radiation, like any accelerated charges. There are now additional field contributions that were not present in the absence of the electron-containing copper.

Consider what happens when the source charges are accelerated continuously, harmonically at a frequency up and down (which involves accelerations as the charges move faster and slower and turn around). Let the sinusoidal acceleration of those source charges continue for a sufficiently long time.  Then the sinusoidal radiation has a phase which is shifted. That is, the peaks come at a different time than they did without the copper interaction.  The interaction of the electric field with the copper can be (for nonobvious reasons) modeled by the electric field exerting a force on an outer electron in an atom as though the electron were bound to the atom by a spring-like force, with damping. The phase shifting is due to the damping term.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 05:23 pm
Quote
What is accelerating?   <<huge accelerations (as Prof. McCulloc assumes for the light/electrons in the EmDrive) >> [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  ]
Where is it accelerating?
Why is it accelerating?
When is it accelerating?
What is the acceleration?

Why is this a mystery? See my earlier post. The electrons within the cavity walls are accelerating in response to the RF wave. It is an AC acceleration of some amplitude at the frequency of the RF waves. Guess the amplitude of the electron oscillation, which is limited by the cavity dimensions and converted to heat by resistance. With the amplitude, then isn't the acceleration just the second derivative? What amplitude is needed to make the theory hold water?

Yes, you understand it.  Now we have to calculate the acceleration involved, before talking about "horizons"
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 05:24 pm
The field at any location outside the copper cavity includes the field contributed by internal charges. However, it looks as though the copper prevents the field from getting out, because the internal charges “polarize” the copper by shifting the mobile electrons in the metal, and the polarized copper contributes an additional electric field outside the container that is equal in magnitude but opposite in direction to the field contributed by the internal charges. The effect is indeed as though the copper “shielded” the copper cavity.

As the electric field contacts the copper, it accelerates the electrons (it accelerates the electrons much more than the protons, due to their very low mass). These accelerated electrons radiate electromagnetic radiation, like any accelerated charges. There are now additional field contributions that were not present in the absence of the electron-containing copper.

Consider what happens when the source charges are accelerated continuously, harmonically at a frequency up and down (which involves accelerations as the charges move faster and slower and turn around). Let the sinusoidal acceleration of those source charges continue for a sufficiently long time.  Then the sinusoidal radiation has a phase which is shifted. That is, the peaks come at a different time than they did without the copper interaction.  The interaction of the electric field with the copper can be (for nonobvious reasons) modeled by the electric field exerting a force on an outer electron in an atom as though the electron were bound to the atom by a spring-like force, with damping.

You are nuking rf cavities. This isn't a particle accelerator. Is that where you are going with this?

If I wanted to accelerate particles, say electrons, I would put positive thousands of volts on one side and negative volts on the other.

This thing has no cathode and no anode. We're on a tangent.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 05:29 pm
The field at any location outside the copper cavity includes the field contributed by internal charges. However, it looks as though the copper prevents the field from getting out, because the internal charges “polarize” the copper by shifting the mobile electrons in the metal, and the polarized copper contributes an additional electric field outside the container that is equal in magnitude but opposite in direction to the field contributed by the internal charges. The effect is indeed as though the copper “shielded” the copper cavity.

As the electric field contacts the copper, it accelerates the electrons (it accelerates the electrons much more than the protons, due to their very low mass). These accelerated electrons radiate electromagnetic radiation, like any accelerated charges. There are now additional field contributions that were not present in the absence of the electron-containing copper.

Consider what happens when the source charges are accelerated continuously, harmonically at a frequency up and down (which involves accelerations as the charges move faster and slower and turn around). Let the sinusoidal acceleration of those source charges continue for a sufficiently long time.  Then the sinusoidal radiation has a phase which is shifted. That is, the peaks come at a different time than they did without the copper interaction.  The interaction of the electric field with the copper can be (for nonobvious reasons) modeled by the electric field exerting a force on an outer electron in an atom as though the electron were bound to the atom by a spring-like force, with damping.

You are nuking rf cavities. This isn't a particle accelerator. Is that where you are going with this?

Where I am going with this is that we have to examine quantitatively the assumptions involved to see whether they are valid before taking them for granted and discussing esoteric quantum gravity.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 05:36 pm
...

If I wanted to accelerate particles, say electrons, I would put positive thousands of volts on one side and negative volts on the other.

This thing has no cathode and no anode. We're on a tangent.
Do I understand you correctly that you take for granted that the huge accelerations needed for Unruh radiation are present, and you think that calculating them is going on a tangent, but you think that esoteric quantum gravity unification discussion is not a tangent?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 05:38 pm
...

If I wanted to accelerate particles, say electrons, I would put positive thousands of volts on one side and negative volts on the other.

This thing has no cathode and no anode. We're on a tangent.
Do I understand you correctly that you take for granted that the huge accelerations needed for Unruh radiation are present, and you think that calculating them is going on a tangent, but you think that esoteric quantum gravity unification discussion is not a tangent?

No you don't understand  what I'm telling you. I've been saying for quite a while that Unruh Radiation is not a factor here. That comes up if you are undergoing very high accelerations. Nothing in this system is doing that.

You are confusing Unruh radiation and the length of allowable Unruh waves. Separate casimir from the heat bath of high acceleration.

Unfortunately Unruh radiation and Unruh waves share the same name. Leading to confusion of terms.

I never said what I observed last night wasn't a tangent. The beauty of his theory is applicable to emdrive and science as a whole. It is a tangent though.
Title: Re: EM Drive Developments
Post by: aero on 10/11/2014 05:45 pm
Well, make it easier. Assume no dissipation by other effects and consider only the electron motion in synchrony with the RF wave. Then the electron moves one complete cycle from A to B with one complete cycle of the RF wave. The cycle time of the RF wave, 1900 MHz, is 1/f = 5.26E-10 seconds. Limit the electron velocity to the speed of light so ... Ok, brain fart. Where does this go?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 05:56 pm
McCulloch, "so we have a mini-MiHsC going on"

Let's pick that apart.

I mentioned that in the summary. I interpreted the effect as a slightly lower inertial mass of particles inside the cavity. Less mass than you would have normally. Remember that there are 4 kinds of mass.

What can we do with that? What are the implications? Does that mean you got a free lunch?

IMHO, that is an opportunity to violate conservation of energy, which you can't. So the energy difference has to be converted to another type, or motion, or given back.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 06:02 pm
http://physicsfromtheedge.blogspot.it/2014/10/in-support-of-empiricism.html

Good Science.
Title: Re: EM Drive Developments
Post by: aero on 10/11/2014 06:16 pm
Well, make it easier. Assume no dissipation by other effects and consider only the electron motion in synchrony with the RF wave. Then the electron moves one complete cycle from A to B with one complete cycle of the RF wave. The cycle time of the RF wave, 1900 MHz, is 1/f = 5.26E-10 seconds. Limit the electron velocity to the speed of light so ... Ok, brain fart. Where does this go?
Ok so we can't do it that way. Here is the correct way but its beyond my poor abilities today.

http://en.wikipedia.org/wiki/Drift_velocity#Numerical_example (http://en.wikipedia.org/wiki/Drift_velocity#Numerical_example)

For alternating current, drift velocity is proportional to the square of frequency...
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 07:15 pm
Well, make it easier. Assume no dissipation by other effects and consider only the electron motion in synchrony with the RF wave. Then the electron moves one complete cycle from A to B with one complete cycle of the RF wave. The cycle time of the RF wave, 1900 MHz, is 1/f = 5.26E-10 seconds. Limit the electron velocity to the speed of light so ... Ok, brain fart. Where does this go?
Ok so we can't do it that way. Here is the correct way but its beyond my poor abilities today.

http://en.wikipedia.org/wiki/Drift_velocity#Numerical_example (http://en.wikipedia.org/wiki/Drift_velocity#Numerical_example)

For alternating current, drift velocity is proportional to the square of frequency...
I doubt Prof. McCulloch is referring to the drift velocity of charges (which is too low).  I have posed the question in his blog [http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html ], to clarify this issue. Thanks.

I disagree with @Mulletron that the thicker the dielectric the better and Mulletron's assumption that what happens inside the dielectric is important.  I think that what happens at the surface of the copper walls and the surface of the dielectric is what matters.

I also disagree with Mulletron regarding the importance of the chirality of the Teflon, the effect in the paper quoted was extremely small even for 10 Tesla magnetic field (velocity of nanometers per second) and a 9 inch solid rod of Teflon that has been injection molded has practically no directionality according to my understanding of injection molding.

I disagree with Mulletron's understanding that Unruh Radiation is not important for the McCulloch inertia explanation of the EMDrive. Mulletron states that nothing is undergoing high accelerations in the EMDrive, but I read the opposite in McCulloch's statement concerning the acceleration of light/electrons.

Also I don't understand how Mulletron separates Unruh radiation from "allowable Unruh waves. Separate casimir". The Unruh wavelengths refer to the wavelengths of Unruh radiation. So how can they be separated?  I don't understand what "separate casimir" is.

Perhaps McCulloch can further clarify in his blog.  I have found McCulloch's short blog answers clarifying.   If I can be shown that I misunderstood something, that's all the better for me to understand what's going on and the explanation being offered.

 
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/11/2014 08:04 pm
Fnarr Dr Rodal fnarr. (Look up Viz comic (Finbar Saunders) and especially Roger's Profanisaurus.)

OK. What mean 'fnarrr'?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/11/2014 08:07 pm
What would be the complications on conducting experiments in my garage?
I would need a copper frustum and optimised dielectric designed by you guys.
RF power source.
Suspend the whole thing from a wire and see if it moves.
Am I missing anything?

Actually, I don't think you're missing anything, if your setup could be optimized to demonstrate well above the noicse floor of the current setup.  If you're putting a couple hundred watts into it, and it moves like a rubber band airplane, then I'd say congratulations, you are success.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/11/2014 08:09 pm
What would be the complications on conducting experiments in my garage?
I would need a copper frustum and optimised dielectric designed by you guys.
RF power source.
Suspend the whole thing from a wire and see if it moves.
Am I missing anything?

Actually, I don't think you're missing anything, if your setup could be optimized to demonstrate well above the noicse floor of the current setup.  If you're putting a couple hundred watts into it, and it moves like a rubber band airplane, then I'd say congratulations, you are success.
Now all I need is a garage to get started!
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/11/2014 08:15 pm
So let me get this straight...[collect copper underpants...

The big question mark is whether the microwave (~2GHz) EmDrive [copper ????] flat walls can make a horizon.

...

Four questions really:

1) Is the NASA Eagleworks truncated cone a complete, closed, Faraday cage, including both flat end surfaces? (are the end surfaces also made of copper?)

2) Is it correct to assume that the light/electrons in the EmDrive experience the huge accelerations required for Unruh radiation ?

3) Is it correct to assume that the Unruh wave patterns close at the [copper ????] flat walls just as at the Hubble horizon ?

4) Is McCulloch's MiHsC theory correct that inertial mass is caused by Unruh radiation, and so it is affected by the Hubble horizon since Unruh waves must fit exactly within this horizon?.

1) we have no idea what's inside the copper frustratum. Who is to say that PCB board is the only thing on the ends, even if one of you guys recognizes the PCB amterial?

2) No.  Not enough energy is going into the mechanism to accelerate all that much all that fast.

3) ?

4) ?

Copper underpants.  The new tin foil hat.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 08:16 pm
http://arxiv.org/pdf/astro-ph/0612599v1.pdf  <<For an object with high acceleration the temperature of the Unruh radiation is high, the Unruh wavelengths seen are short and the Unruh energy spectrum looks like the curve on the left. In the schematic this spectrum is sampled by five or six of the allowed wavelengths so much of the energy in the Unruh spectrum remains. However, if the acceleration is reduced, then the object sees the spectrum on the right. In this case, only one of the wavelengths is allowed because the others do not fit within  and so the spectrum is more sparsely sampled, and the energy of the Unruh radiation is much lower than expected. In this new scheme, some spectral energy is lost at wavelengths shorter than , and this allows the prediction of the Pioneer anomaly,>>

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  <<for normal accelerations a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as [McCulloch] assume(s) for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall because they are partly em waves>>

Short wavelength --> high Unruh radiation

The wavelength of Unruh radiation need to be short enough (less than ~  9 inches) to fit in the flat end surfaces of the truncated cone, for the simplified formula of McCulloch to hold.

This means that there must be an acceleration large enough so that the Unruh radiation wavelengths are short enough to fit in the flat surfaces of the truncated cone.  The center of mass of the truncated cone does not have such an acceleration, no way.  Only the light/electrons can have such an acceleration.  Without Unruh radiation there is no McCulloch correction to the inertial mass, see:  http://arxiv.org/pdf/astro-ph/0612599v1.pdf   

I find this statement by McCulloch very clear:

<<(1) Inertia is a reaction to Unruh radiation and (2) this reaction is weaker for low accelerations because some wavelengths in the Unruh spectrum do not fit within a limiting scale >>
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 08:39 pm
To be clear, unruh waves are synonymous with saying all possible radiation because the unruh waves and unruh radiation is tied to the vacuum which is stochastic.

9 inches is 1315.78 mhz.

I maintain that inertial mass is the result of all interaction.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 08:43 pm
To be clear, unruh waves are synonymous with saying all possible radiation because the unruh waves and unruh radiation is tied to the vacuum which is stochastic.

9 inches is 1315.78 mhz.

We disagree, on this treatment too.  What matters mostly is the wavelength corresponding to the  peak of the energy curve.  That's why Prof.McCulloch is referring to the acceleration of light/electrons.

Otherwise, one could say that any accelerating body has Unruh radiation to some degree, and a distribution of wavelengths as well and you could say these wavelengths or those wavelengths.

If one doesn't consider the energy curve, it becomes gob·ble·dy·gook :)

One must consider the energy vs wavelength curve, as done by Prof McCulloch
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 08:45 pm
To be clear, unruh waves are synonymous with saying all possible radiation because the unruh waves and unruh radiation is tied to the vacuum which is stochastic.

9 inches is 1315.78 mhz.
and 6 inches for the other end is what frequency ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 08:51 pm
6 inches is 1969mhz
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 08:53 pm
6 inches is 1974mhz
Bingo !
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 08:55 pm
Rounded vs not rounded

How many times have I said that energy is constrained over time now? Jeez...
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 09:02 pm
OK, we got an answer:

Dr. Rodal:  <<Prof. McCulloch, do I understand correctly the statement "a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall" to mean that for your above simplified formula to be based on MiHsC, the accelerations of the electrons need to be large enough so that Unruh radiation can significantly affect the inertial mass such that milliNewton forces can be experienced?>>


Prof. McCulloch:  <<Yes: the accelerating objects inside the shell/cavity must accelerate (a) fast enough that the Unruh waves they see become short enough to be damped by the shell. The formula is: wavelength~8c^2/a so, for example, to get Unruh waves 1 metre long you need a=7.2*10^17 m/s^2.>>
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 09:25 pm
OK, we got an answer:

Dr. Rodal:  <<Prof. McCulloch, do I understand correctly the statement "a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall" to mean that for your above simplified formula to be based on MiHsC, the accelerations of the electrons need to be large enough so that Unruh radiation can significantly affect the inertial mass such that milliNewton forces can be experienced?>>


Prof. McCulloch:  <<Yes: the accelerating objects inside the shell/cavity must accelerate (a) fast enough that the Unruh waves they see become short enough to be damped by the shell. The formula is: wavelength~8c^2/a so, for example, to get Unruh waves 1 metre long you need a=7.2*10^17 m/s^2.>>

Ok I get it. You're trying to calculate the acceleration of particles to fit within the band gap of what the walls are excluding. Don't forget the plasma frequency of the material too.

Well those are pretty daunting, never mind. You done good.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 09:32 pm
OK, we got an answer:

Dr. Rodal:  <<Prof. McCulloch, do I understand correctly the statement "a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall" to mean that for your above simplified formula to be based on MiHsC, the accelerations of the electrons need to be large enough so that Unruh radiation can significantly affect the inertial mass such that milliNewton forces can be experienced?>>


Prof. McCulloch:  <<Yes: the accelerating objects inside the shell/cavity must accelerate (a) fast enough that the Unruh waves they see become short enough to be damped by the shell. The formula is: wavelength~8c^2/a so, for example, to get Unruh waves 1 metre long you need a=7.2*10^17 m/s^2.>>

Ok I get it. You're trying to calculate the acceleration of particles to fit within the band gap of what the walls are excluding. Don't forget the plasma frequency of the material too.

I don't understand "the plasma frequency of the material " in this case (EM Drive).

Non si capisce più niente
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 09:39 pm
OK, we got an answer:

Dr. Rodal:  <<Prof. McCulloch, do I understand correctly the statement "a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall" to mean that for your above simplified formula to be based on MiHsC, the accelerations of the electrons need to be large enough so that Unruh radiation can significantly affect the inertial mass such that milliNewton forces can be experienced?>>


Prof. McCulloch:  <<Yes: the accelerating objects inside the shell/cavity must accelerate (a) fast enough that the Unruh waves they see become short enough to be damped by the shell. The formula is: wavelength~8c^2/a so, for example, to get Unruh waves 1 metre long you need a=7.2*10^17 m/s^2.>>

Ok I get it. You're trying to calculate the acceleration of particles to fit within the band gap of what the walls are excluding. Don't forget the plasma frequency of the material too.

I didn't know there was any plasma frequency to consider.   What is "plasma frequency"?

Non si capisce più niente

Wish I hadn't gone there. It is the upper frequency limit of a material.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 09:49 pm
OK, we got an answer:

Dr. Rodal:  <<Prof. McCulloch, do I understand correctly the statement "a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall" to mean that for your above simplified formula to be based on MiHsC, the accelerations of the electrons need to be large enough so that Unruh radiation can significantly affect the inertial mass such that milliNewton forces can be experienced?>>


Prof. McCulloch:  <<Yes: the accelerating objects inside the shell/cavity must accelerate (a) fast enough that the Unruh waves they see become short enough to be damped by the shell. The formula is: wavelength~8c^2/a so, for example, to get Unruh waves 1 metre long you need a=7.2*10^17 m/s^2.>>

Ok I get it. You're trying to calculate the acceleration of particles to fit within the band gap of what the walls are excluding. Don't forget the plasma frequency of the material too.

I didn't know there was any plasma frequency to consider.   What is "plasma frequency"?


Wish I hadn't gone there. It is the upper frequency limit of a material.

I apologize for my bad italian. I meant to write <<no capisce>> that I didn't understand
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 09:53 pm
OK, we got an answer:

Dr. Rodal:  <<Prof. McCulloch, do I understand correctly the statement "a metal box will not effect Unruh waves because for typical accelerations (9.8m/s^2) they are light years long, but for huge accelerations (as I assume for the light/electrons in the EmDrive) the Unruh waves are affected by the copper wall" to mean that for your above simplified formula to be based on MiHsC, the accelerations of the electrons need to be large enough so that Unruh radiation can significantly affect the inertial mass such that milliNewton forces can be experienced?>>


Prof. McCulloch:  <<Yes: the accelerating objects inside the shell/cavity must accelerate (a) fast enough that the Unruh waves they see become short enough to be damped by the shell. The formula is: wavelength~8c^2/a so, for example, to get Unruh waves 1 metre long you need a=7.2*10^17 m/s^2.>>

Ok I get it. You're trying to calculate the acceleration of particles to fit within the band gap of what the walls are excluding. Don't forget the plasma frequency of the material too.

I didn't know there was any plasma frequency to consider.   What is "plasma frequency"?


Wish I hadn't gone there. It is the upper frequency limit of a material.

I apologize for my bad italian. I meant to write <<no capisce>> that I didn't understand

I know what it is but I'm shaky on how to calculate it. Don't make me do math! That's your job.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 09:55 pm
To recapitulate:

 <<Yes: the accelerating objects inside the shell/cavity must accelerate (a) fast enough that the Unruh waves they see become short enough to be damped by the shell. The formula is: wavelength~8c^2/a so, for example, to get Unruh waves 1 metre long you need a=7.2*10^17 m/s^2.>>

We need to show that photons and/or electrons are accelerating to an acceleration exceeding a=7.2*10^17 m/s^2 in order to justify the McCulloch inertial mass change in this case.

What is accelerating? (electrons or photons or both?)
Where is the acceleration taking place?  (I propose: at the surface boundaries, that is at the inner copper surfaces and at the dielectric outer surfaces)
Why is the acceleration taking place? (we have to show that this is due to the microwave frequency for example)
When is the acceleration taking place?  (we need to show that this is happening during the 30 to 45 sec thrust pulses)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/11/2014 10:02 pm
You're losing me. Where did you find your nuke hat? The thing has a quiet zone inside. Because it is a copper can. Just measure it with a probe and a spec anny.
Title: Re: EM Drive Developments
Post by: Rodal on 10/11/2014 10:31 pm
You're losing me. Where did you find your nuke hat? The thing has a quiet zone inside. Because it is a copper can. Just measure it with a probe and a spec anny.
OK, step by step then. Chi va piano va sano e va lontano

1) REQUIREMENT that must be satisfied for McCulloch's formula <<the accelerating objects inside the shell/cavity must accelerate (a) fast enough that the Unruh waves they see become short enough to be damped by the shell. The formula is: wavelength~8c^2/a so, for example, to get Unruh waves 1 metre long you need a=7.2*10^17 m/s^2.>> (Reference: http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html)

2) What objects inside the cavity are accelerating to 7.2*10^17 m/s^2 ?

that is an acceleration of

730,000,000,000,000,000

times larger than 1 g.
Title: Re: EM Drive Developments
Post by: aero on 10/11/2014 10:46 pm
Well, for what its worth I calculate the skin depth for copper at 1900 MHz is about 1.5 microns.

The electron acceleration I get is about 7.7 g's. Not near high enough.

And note, to be precise, the cavity dimensions are about 0.25146 m major dia., 0.16764 m minor dia. 0.2286 m height. (Picked off the screen picture with a ruler scaling to the 1.5 inch cross section of the support arm.)

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/11/2014 11:24 pm
Non si capisce più niente ... (http://forum.nasaspaceflight.com/index.php?PHPSESSID=iof8dv6tn0rm94f3i3c03na3c6&topic=29276.msg1269526#msg1269526)

U talkin' to me?  Oh wait...

Non capisco.   Pourriez-vous ralentir, pardenaire?

Y'all still don't really know what's inside the dern thing, do ya?
Title: Re: EM Drive Developments
Post by: aero on 10/11/2014 11:33 pm
By the way, that acceleration will exceed the speed of light in less than one cycle of the RF wave.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 01:44 am
And of course, for the photoelectric effect, to emit electrons from the surface of the copper, the microwave frequency is way too low:

Planck constant= 6.63×10^(−34) J s
Frequency = 1.93x10^9 1/s
Copper Photoelectric Work Function = 7.5 × 10^(−19) J

Kinetic Energy of Emitted Electron = (6.63×10^(−34) J s)x(1.93x10^9 1/s) - 7.5 × 10^(−19) J
                                                    = 1.28x10^(-24) J - 7.5 × 10^(−19) J
                                                     < 0                                                               

To emit electrons from the surface of the copper by the photoelectric effect, the frequency of the microwave is way too low, by a factor of about a million. 
Title: Re: EM Drive Developments
Post by: aero on 10/12/2014 03:56 am
Electrons must come from the dielectric. At least that would explain why no thrust without dielectric.

If electrons are involved at all. What role do you see electrons playing in this device?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 05:14 am
You hit the nail on the head when you mentioned the skin effect. Those accelerating electrons in the walls reacting to the rf stay inside. The only thing that makes it outside is uneven heating. Hence why you need to react against something for the thing to work. Otherwise you have a big fancy space heater thruster. Quantum thrust is the answer.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 05:15 am
Since we cannot see how the electrons in the copper would be accelerated to the required acceleration, let's examine the photons.

Extremely high accelerations are involved when photons are reflected at the copper surface.  Velocity is a vector of course: a change in direction is a change in velocity.  The highest acceleration is the one resulting from a photon traveling perpendicular to a flat surface, being reflected from the surface so that it travels in the opposite direction. 

The photons reflected from the copper are identical to the incident ones, apart from the changed propagation direction. Some fraction of the photons are lost, while the energy content of each reflected photon is fully preserved. Which of the photons are lost is a matter of chance; there is a certain probability for each photon to be absorbed. There will be complete reflection (and no heating of the metal) in most cases and complete absorption with associated heating (creation of so-called phonons in the metal) in some cases.

Question: does acceleration due to reflection (due to a change in direction but no change in magnitude) satisfy the requirement of high acceleration for the Unruh radiation for McCulloch's simplified formula?
Is Unruh radiation involved whenever light hits a mirror ?






The dominant behavior in this case is reflection of course, but here is a discussion of group velocity (as used by Shawyer)  and phase velocity (as appearing in the refractive index)

1) The simplified McCulloch formula is similar to the Shawyer formula (albeit from completely different derivation and physical reasons): Power*Q/f*(1/radiusA - 1/radiusB).   Shawyer's derivation involves the group velocity. 

2) The refractive index can be involved to a very small extent when a photon hits the copper surface with wavelengths smaller than a few micrometers.  But for the EMDrive we are dealing with much longer wavelengths in the order of 0.1 to 1 meters, (hundreds of thousand times longer wavelength).

The refractive index is inversely proportional to the phase velocity of light: 

Refractive index = (velocity of light in a vacuum)/(phase velocity of light in the substance)

The phase velocity is the speed at which the crests of the wave move.    In copper the phase velocity [ for wavelengths exceeding 10 micrometers] is much lower than the speed of light in a vacuum.  The refractive index is much higher than 1 (actually much higher than 10 for the wavelengths exceeding 10 micrometers), and there are very high absorption losses at those wavelengths.

Real part of refractive index ( indicates the phase velocity):
(http://refractiveindex.info/legacy/figures/figures_RI/n_METALS_Copper_Palik.png)

Imaginary part of refractive index (indicates the amount of absorption loss when the electromagnetic wave propagates through the material.)

(http://refractiveindex.info/legacy/figures/figures_RI/k_METALS_Copper_Palik.png)




This example is not a good example for refraction in copper.  I only show it to illustrate what is the phase velocity[appearing in the refractive index] and what is the group velocity [used by Shawyer].

(http://upload.wikimedia.org/wikipedia/commons/b/bd/Wave_group.gif)

 The red dot moves with the phase velocity, and the green dots propagate with the group velocity. In this case, the phase velocity is twice the group velocity. The red dot overtakes two green dots when moving from the left to the right of the figure.

Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 05:43 am
I get that phase velocity can out run group velocity and can even be superluminal but where's the thrust? It is a closed system.


I hope you're on to something. I'd like to do away with quantum thrust too and explain anomalous thrust in a simpler way, besides uneven heating.

Title: Re: EM Drive Developments
Post by: aero on 10/12/2014 05:44 am
If it's any help, some time ago I used E = mc^2 and calculated the energy mass of the stored energy within the cavity. I got -

1, TM211   1.37644E-12   kg
2, TM211   3.36321E-12   kg
3, TE012   6.36436E-13   kg

I don't know if this factors into the problem or not.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/12/2014 10:03 am
Well, for what its worth I calculate the skin depth for copper at 1900 MHz is about 1.5 microns.

The electron acceleration I get is about 7.7 g's. Not near high enough.

And note, to be precise, the cavity dimensions are about 0.25146 m major dia., 0.16764 m minor dia. 0.2286 m height. (Picked off the screen picture with a ruler scaling to the 1.5 inch cross section of the support arm.)

7.7g ???

If I understand Rodal, the idea would be to consider the oscillating electrons as a moving wall (a bit like the "moving mirror" in dynamical Casimir effect experiments). Those electrons wouldn't be ejected, they are accelerated back and forth but kept at stationary position (averaged on a period), it's like a "vibratory wall". During a half period that is 1/(2freq) all electrons could go for a back and forth trip of half a skin depth (considering only moves normal to the surfaces are relevant as for a moving "volume"). Give or take a 0.5 factor somewhere we are about max acceleration = skin_depth * freq² = 1.5e-6 * 1.9e9² = 5.4e12 m/s², huge but five orders of magnitude below needed acceleration for Unruh waves of 1m long (from McCulloch as reported by Rodal). That's by assuming all electrons go full back and forth oscillation at skin depth.

Was that it ?

One more paper to devour (?) not already linked to (??)
http://arxiv.org/abs/1103.0835
I like fig. 2 page 4 that links the different effects.

I don't see photons could play the role of a moving wall for a cavity bouncing photons (virtual or real).
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 10:20 am
Well, for what its worth I calculate the skin depth for copper at 1900 MHz is about 1.5 microns.

The electron acceleration I get is about 7.7 g's. Not near high enough.

And note, to be precise, the cavity dimensions are about 0.25146 m major dia., 0.16764 m minor dia. 0.2286 m height. (Picked off the screen picture with a ruler scaling to the 1.5 inch cross section of the support arm.)

7.7g ???

If I understand Rodal, the idea would be to consider the oscillating electrons as a moving wall (a bit like the "moving mirror" in dynamical Casimir effect experiments). Those electrons wouldn't be ejected, they are accelerated back and forth but kept at stationary position (averaged on a period), it's like a "vibratory wall". During a half period that is 1/(2freq) all electrons could go for a back and forth trip of half a skin depth (considering only moves normal to the surfaces are relevant as for a moving "volume"). Give or take a 0.5 factor somewhere we are about max acceleration = skin_depth * freq² = 1.5e-6 * 1.9e9² = 5.4e12 m/s², huge but five orders of magnitude below needed acceleration for Unruh waves of 1m long (from McCulloch as reported by Rodal). That's by assuming all electrons go full back and forth oscillation at skin depth.

Was that it ?

One more paper to devour (?) not already linked to (??)
http://arxiv.org/abs/1103.0835
I like fig. 2 page 4 that links the different effects.

I don't see photons could play the role of a moving wall for a cavity bouncing photons (virtual or real).

That is a good find and thank you. I'm starting to see a pattern here. Every way I look at emdrive, the quantum vacuum keeps getting put back on the table. (Confirmation bias or something real?) I'm going to spend the rest of the day digesting this paper.

You're right, figure 2 does a great job demonstrating the relations of all those in the presence of gravitational accelerations.

The walls of the cavity, in addition to the static casimir effects already postulated, could be exhibiting a weak dynamical casimir effect by virtue of the movements of the electrons. They aren't a moving mirror so this is very loosely correlated. How can a moving electron act as a moving mirror affecting any modes if any? The surface isn't exactly reflective in the optical sense, but it is to other wavelengths. Should the emdrive be silvered? Or covered in DLP like chips, to enhance this? Now I'm falling down another rabbit hole.

http://www.youtube.com/watch?v=eDzqqsTFywk

I imagine the whole cavity vibrates like this when rf is on. I can tell you from experience from radars, if you touch the outside of a magnetron while it is on, you feel a nice vibration or hum.

Rodal, is this where you were going?

http://www.youtube.com/watch?v=r2txJBvjw5I

Also, what is the parametric parameter with emdrive? Is there one?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 12:25 pm
Well it looks like some Egyptian physics student named Aisha Mustafa has already invented this type of dynamic casimir effect quantum thruster. Another ball in EMdrive's court.

So we have Sonny White, Shawyer (though he isn't saying emdrive is being driven quantumly, and the consensus is his representations about how why his own invention works don't make sense, he might not know how why it works, he just knows it works), and this Egyptian girl all working on the same thing in parallel.

http://www.emdrive.com/theorypaper9-4.pdf Shawyer's latest theory paper.

Oh and Woodward too (same as Shawyer), and who knows who else is working on this kind of propulsion.

Seems like many people are grasping at the same ideas here in parallel.

Another very good sign that EMdrive probably really works.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/12/2014 01:08 pm
Another very good sign that EMdrive probably really works.

NO! NO! A Thousand Times No! (http://www.youtube.com/watch?v=wnJb2kCg0M4)

Another good sign that the promise of the drive excites the imagination, and results in a good deal of professional interest.

Film note:  One of my earlier pieces.

Hark ye!
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 01:16 pm
Another very good sign that EMdrive probably really works.

NO! NO! A Thousand Times No! (http://www.youtube.com/watch?v=wnJb2kCg0M4)

Another good sign that the promise of the drive excites the imagination, and results in a good deal of professional interest.

Film note:  One of my earlier pieces.

Hark ye!

I'm assuming I can trust the experimentalists. You're right though. It doesn't officially work until it is undeniable.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 01:24 pm
Back to the real world after all this Mustafa FLT, dynamic and static Casimir effects with non-existing plates at an infinitesimal distance from each other, back to the real world  :)

As Prof. McCulloch posted today (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html), the acceleration of the photons transiting the cavity is

a = 2 c^2 / (CavityLength)

and recall that for Unruh radiation McCulloch inertial mass change we must have

a > 8 c^2 / (DiameterOfFlatSurface)

So we need,

2 c^2 / (CavityLength) > 8  c^2 / (DiameterOfFlatSurface)

or

(DiameterOfFlatSurface)/(CavityLength)  > 4

Which is not satisfied for these EMDrives. 

Actually

For the NASA Eagleworks truncated cone, using the radius of the larger flat surface:

(DiameterOfFlatSurface)/(CavityLength)  ~ 1

So the acceleration required for Unruh radiation waves is about 4 times greater than the actual photon acceleration in the cavity.

As Prof. McCulloch states:  "this is a wild leap".




Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/12/2014 01:42 pm
2) What objects inside the cavity are accelerating to 7.2*10^17 m/s^2 ?

...that is an acceleration of
730,000,000,000,000,000
times larger than 1 g.

By the way, that acceleration will exceed the speed of light in less than one cycle of the RF wave.

Somebody check this?  Before I call el poopo del toro?

I get that phase velocity can out run group velocity and can even be superluminal but where's the thrust?

There is no thrust in group velocity.  Period.

Reading up on the Unruh thingy, first, a typical grammatical objection:

Vacuum is simply thought to be the lowest possible energy state of these fields. (http://en.wikipedia.org/wiki/Unruh_effect#Explanation)

Dammit!  There is nothing "simple" about this.  Somebody fix this dang site.

I would never dare speak for the peanut gallery, but I'm struggling with accepting an effect which has not been observed as being postulated for another effect, anomalous thrust, which has not yet been reliably and repeatedly observed by others in the scientific community.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/12/2014 01:58 pm
The walls of the cavity, in addition to the static casimir effects already postulated, could be exhibiting a weak dynamical casimir effect by virtue of the movements of the electrons. They aren't a moving mirror so this is very loosely correlated. How can a moving electron act as a moving mirror affecting any modes if any? The surface isn't exactly reflective in the optical sense, but it is to other wavelengths. Should the emdrive be silvered? Or covered in DLP like chips, to enhance this? Now I'm falling down another rabbit hole.

A sea of free electrons is a mirror, for wavelengths longer than distance between them (optical yes, microwave definitely) so moving electrons do behave as a moving mirror (with a very low inertia compared to a solid mirror). Actually it is the "recoil" of being a mirror for the microwaves that makes them move and could make them move for other wavelength. Then the space charge prevent them to leave completely : they are bound within a certain depth by the positive holes they left in the lattice by moving... Basically this is a capacitor : applied E field => proportional charge displacements. That said, I'm far form certain this makes any sense : wouldn't the free electron (of the copper walls) move tangentially rather than normal to the surfaces to "counteract" the incoming E field and making the RF wave bounce ? What are the patterns of the "eddy currents" in presence of standing waves ? Intuitively I would say we have large scale current loops trying to make a H field normal to surface, that is tangential currents, not normal back and forth like a capacitor. If the charge displacements are tangential then the "mirror" isn't really moving (constant enclosed volume).

If alternating back and forth in the depth, then we have (from capacitor (http://en.wikipedia.org/wiki/Capacitor) analogy) density of electrons rho=Q/A (Charge on Area) and electric field E=rho/eps (permittivity). From  8.5×10^28 electrons per cubic metre (http://en.wikipedia.org/wiki/Drift_velocity#Numerical_example) for copper we have 1.36e10 Coulomb/m^3 that is rho=2e4 C/m² at 1.5µm depth and E = 2e4/8.8e-12 = 2.3e15 V/m. See also permittivity (http://en.wikipedia.org/wiki/Permittivity) D=eps E  : D is same as rho (C/m²) E electric field (V/m) and eps whatever...
I'm doing as if the electrons of the copper were in vacuum...

Mmm, this E is not in excess of vacuum dielectric strength (1e18 V/m)  What are the E fields reported for the EMdrives resonant cavities ? Because this is in far excess of air (3e6 V/m) and even teflon (up to 1.7e8 V/m) dielectric strength. So even if high Q factor could pump up E field amplitude to such levels, materials would experience breakdown. Unless I messed up a 10^9 factor somewhere again ?
And such a hypothetical move of all electrons back and forth to skin depth can only make for about 5e12m/s² moving (oscillating mirror) : is it enough ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 02:06 pm
By what logic are you assuming a photon would see unruh radiation when the speed of light is the same in all reference frames?

This accelerating photon seeing unruh radiation stuff is nonsense.

So is any notion of thrust using differences between group or phase velocities. Shawyer tried using the different group velocity argument.

The fact is that for any rocket to work it has to react against something.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 02:08 pm
The walls of the cavity, in addition to the static casimir effects already postulated, could be exhibiting a weak dynamical casimir effect by virtue of the movements of the electrons. They aren't a moving mirror so this is very loosely correlated. How can a moving electron act as a moving mirror affecting any modes if any? The surface isn't exactly reflective in the optical sense, but it is to other wavelengths. Should the emdrive be silvered? Or covered in DLP like chips, to enhance this? Now I'm falling down another rabbit hole.

A sea of free electrons is a mirror, for wavelengths longer than distance between them (optical yes, microwave definitely) so moving electrons do behave as a moving mirror (with a very low inertia compared to a solid mirror). Actually it is the "recoil" of being a mirror for the microwaves that makes them move and could make them move for other wavelength. Then the space charge prevent them to leave completely : they are bound within a certain depth by the positive holes they left in the lattice by moving... Basically this is a capacitor : applied E field => proportional charge displacements. That said, I'm far form certain this makes any sense : wouldn't the free electron (of the copper walls) move tangentially rather than normal to the surfaces to "counteract" the incoming E field and making the RF wave bounce ? What are the patterns of the "eddy currents" in presence of standing waves ? Intuitively I would say we have large scale current loops trying to make a H field normal to surface, that is tangential currents, not normal back and forth like a capacitor. If the charge displacements are tangential then the "mirror" isn't really moving (constant enclosed volume).

If alternating back and forth in the depth, then we have (from capacitor (http://en.wikipedia.org/wiki/Capacitor) analogy) density of electrons rho=Q/A (Charge on Area) and electric field E=rho/eps (permittivity). From  8.5×10^28 electrons per cubic metre (http://en.wikipedia.org/wiki/Drift_velocity#Numerical_example) for copper we have 1.36e10 Coulomb/m^3 that is rho=2e4 C/m² at 1.5µm depth and E = 2e4/8.8e-12 = 2.3e15 V/m. See also permittivity (http://en.wikipedia.org/wiki/Permittivity) D=eps E  : D is same as rho (C/m²) E electric field (V/m) and eps whatever...
I'm doing as if the electrons of the copper were in vacuum...

Mmm, this E is not in excess of vacuum dielectric strength (1e18 V/m)  What are the E fields reported for the EMdrives resonant cavities ? Because this is in far excess of air (3e6 V/m) and even teflon (up to 1.7e8 V/m) dielectric strength. So even if high Q factor could pump up E field amplitude to such levels, materials would experience breakdown. Unless I messed up a 10^9 factor somewhere again ?
And such a hypothetical move of all electrons back and forth to skin depth can only make for about 5e12m/s² moving (oscillating mirror) : is it enough ?
The maximum electric fields at the dielectric are calculated to be 47000 V/m.  The electric field in the cavity is only about 1500 to 2000 V/m.
I am on record since I entered this thread that I see nothing whatsoever in these EMDrives related to the hypothetical Dynamic Casimir effect.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/12/2014 02:10 pm
2) What objects inside the cavity are accelerating to 7.2*10^17 m/s^2 ?

...that is an acceleration of
730,000,000,000,000,000
times larger than 1 g.

By the way, that acceleration will exceed the speed of light in less than one cycle of the RF wave.

Somebody check this?  Before I call el poopo del toro?

7.2e17*(1/1.9e9) = 3.8e8 m/s = 380000km/s
exceeding light speed yes, but only slightly, I guess for such a small deviation we should be tolerant. For instance since the movement would be periodic and sinusoidal, this would be the max acceleration (at peaks) and the max speed in between (crossing the middle line) could be below c I believe. Also m/s² is ill defined when approaching relativistic speeds, no ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 02:14 pm
By what logic are you assuming a photon would see unruh radiation when the speed of light is the same in all reference frames?

This accelerating photon seeing unruh radiation stuff is nonsense.

...

Non sequitur and unfounded.

Please go to http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html
and follow the discussion on the comments section.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/12/2014 02:21 pm
By what logic are you assuming a photon would see unruh radiation when the speed of light is the same in all reference frames?

Are you asking that to me ?
I don't think a photon would see Unruh radiation, I think a moving "wall of electrons" (periodically) accelerating at great values could see Unruh radiation. I believe the speed of light is the same in all inertial reference frames. I don't believe in the claimed results so far, I think a number of more or less exotic effects could be used to get net forward thrust from power, but not at better than 1/c (as Newtons/Watts). But I'm not qualified to have any authority on the subject, just trying to follow.
Maybe your question was addressed to dr Rodal ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 02:27 pm
By what logic are you assuming a photon would see unruh radiation when the speed of light is the same in all reference frames?

Are you asking that to me ?
I don't think a photon would see Unruh radiation, I think a moving "wall of electrons" (periodically) accelerating at great values could see Unruh radiation. I believe the speed of light is the same in all inertial reference frames. I don't believe in the claimed results so far, I think a number of more or less exotic effects could be used to get net forward thrust from power, but not at better than 1/c (as Newtons/Watts). But I'm not qualified to have any authority on the subject, just trying to follow.
Maybe your question was addressed to dr Rodal ?
If the question was directed to me, the presumptive assumption in the question is unfounded concerning me:  as one can ascertain by the discussion in: http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html
.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/12/2014 02:29 pm
Just read the oracle on the Pioneer Anomaly.  It is thought to be caused by thermal effects, as of 2011-ish.  Is this not the case?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/12/2014 02:31 pm
Just read the oracle on the Pioneer Anomaly.  It is thought to be caused by thermal effects, as of 2011-ish.  Is this not the case?
What has that got to do with anything?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/12/2014 02:33 pm
Just read the oracle on the Pioneer Anomaly.  It is thought to be caused by thermal effects, as of 2011-ish.  Is this not the case?
What has that got to do with anything?

http://arxiv.org/abs/astro-ph/0612599

http://arxiv.org/abs/1004.3303

Basically everything.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/12/2014 02:37 pm
Just read the oracle on the Pioneer Anomaly.  It is thought to be caused by thermal effects, as of 2011-ish.  Is this not the case?
What has that got to do with anything?

http://arxiv.org/abs/astro-ph/0612599

http://arxiv.org/abs/1004.3303

Basically everything.
The links you quote have nothing to do with thermal effects. I think you are confused.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 02:38 pm
By what logic are you assuming a photon would see unruh radiation when the speed of light is the same in all reference frames?

This accelerating photon seeing unruh radiation stuff is nonsense.

...

Non sequitur and unfounded.

Please go to http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html
and follow the discussion on the comments section.

A photon starts off at C. They don't accelerate to C.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 02:40 pm
By what logic are you assuming a photon would see unruh radiation when the speed of light is the same in all reference frames?

This accelerating photon seeing unruh radiation stuff is nonsense.

...

Non sequitur and unfounded.

Please go to http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html
and follow the discussion on the comments section.

A photon starts off at C. They don't accelerate.

What part of << but the acceleration of the photons is 2c^2/cavitysize~9*10^17 m/s^2.>> in http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html are you ascribing to me?

If you have an argument why don't you pursue it in http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html ?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/12/2014 02:41 pm
Just read the oracle on the Pioneer Anomaly.  It is thought to be caused by thermal effects, as of 2011-ish.  Is this not the case?
What has that got to do with anything?

http://arxiv.org/abs/astro-ph/0612599

http://arxiv.org/abs/1004.3303

Basically everything.
The links you quote have nothing to do with thermal effects. I think you are confused.

The links have everything to do with the Pioneer anomaly, which pertain to  McCulloch's theory of MiHsC.   Loook harder.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 02:43 pm
Just read the oracle on the Pioneer Anomaly.  It is thought to be caused by thermal effects, as of 2011-ish.  Is this not the case?
What has that got to do with anything?

http://arxiv.org/abs/astro-ph/0612599

http://arxiv.org/abs/1004.3303

Basically everything.
The links you quote have nothing to do with thermal effects. I think you are confused.

The links have everything to do with the Pioneer anomaly, which pertain to  McCulloch's theory of MiHsC.   Loook harder.

But the Pioneer anomaly, or the EMDrive explanation, and any other anomaly of a man-made object is not a fair test of the quantised inertia Unruh theory.

A fair test would be the existence or non-existence of dark matter.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/12/2014 02:44 pm
Just read the oracle on the Pioneer Anomaly.  It is thought to be caused by thermal effects, as of 2011-ish.  Is this not the case?
What has that got to do with anything?

http://arxiv.org/abs/astro-ph/0612599

http://arxiv.org/abs/1004.3303

Basically everything.
The links you quote have nothing to do with thermal effects. I think you are confused.

The links have everything to do with the Pioneer anomaly, which pertain to  McCulloch's theory of MiHsC.   Loook harder.
No. Try reading harder. You state it is due to thermal effects. Which it may be.
However you then link to McCullochs papers. Not thermal, but MiHsC.
Which is it?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/12/2014 03:07 pm

Quote from: JF
The links have everything to do with the Pioneer anomaly, which pertain to  McCulloch's theory of MiHsC.   Loook harder.

No. Try reading harder. You state it is due to thermal effects. Which it may be.
However you then link to McCullochs papers. Not thermal, but MiHsC.
Which is it?

Semantic check here, speaking of reading harder.

I only report that the Pioneer Anomaly is due to thermal effects.  I do not state that is the case.  Apparently McCulloch disagrees, and in the two papers linked, states that MiHsC could be an explanation for the Pioneer Anomaly.

The earlier paper is more obvious:

Quote from: McCulloch, 2008, first sentence
This paper proposes an explanation for the Pioneer anomaly:

And the later one, more incidental:

Quote from: McCulloch, 2010
The Pioneer anomaly is similar to the galaxy rotation problem.

You certainly have a good reason to ask me "which is it?", but you would just be repeating my question, as I offer no answers.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/12/2014 03:09 pm
All good then. I offer no solution either...  :)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/12/2014 03:18 pm
But the Pioneer anomaly, or the EMDrive explanation, and any other anomaly of a man-made object is not a fair test of the quantised inertia Unruh theory.

A fair test would be the existence or non-existence of dark matter.

No lo comprendo, kemosabe.  Explica para nosotros, party favor?

Are you saying that DM is that which without which they ain't no swing?

That is, why wouldn't a man-made experiment be, in principle, disallowed as a test of a theory? 

Me no unnerstand.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 03:25 pm
But the Pioneer anomaly, or the EMDrive explanation, and any other anomaly of a man-made object is not a fair test of the quantised inertia Unruh theory.

A fair test would be the existence or non-existence of dark matter.

No lo comprendo, kemosabe.  Explica para nosotros, party favor?

Are you saying that DM is that which without which they ain't no swing?

That is, why wouldn't a man-made experiment be, in principle, disallowed as a test of a theory? 

Me no unnerstand.
McCulloch's quantised inertia based on Unruh radiation is a physical theory, not an engineering theory and not a theory-of-everything.

The Pioneer spacecraft and the EMDrives are man-made objects imperfectly known.  Not even the fastest supercomputer in the world can predict its material properties based on Quantum Mechanics, for that one would used Continuum Mechanics, Finite Element analysis and so on.  The Pioneer anomaly was explained by JPL based on thermal effects on the basis of a complex Finite Element computational analysis, that took a long-time to carry out, capisce?

The test of a physical theory should be effects that can be solely explained by a physical theory.  For example the perihelion precesion of Mercury for General Relativity.   But never man-made objects engineered by men that are imperfectly known, and for which Engineering (Continuum Mechanics, Heat Transfer, etc.) is needed.


Same for McCulloch's quantised inertia.  A proper test would be the existence or non-existence of Dark Matter.  Recall that McCulloch's theory explains the astrophysical measurements without the need for any Dark Matter.  Capisce ?


Read:  http://arxiv.org/pdf/1207.7007v1.pdf
Title: Re: EM Drive Developments
Post by: aero on 10/12/2014 04:23 pm
I don't know how this inters the discussion, but have we overlooked the part about the cavity being filled with air?

To what degree would the air ionize producing ions/electrons in the mix? Ions would be massive but the electrons should be free to move about.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 04:29 pm
I don't know how this inters the discussion, but have we overlooked the part about the cavity being filled with air?

To what degree would the air ionize producing ions/electrons in the mix? Ions would be massive but the electrons should be free to move about.

Yes we discussed that several pages along.  It was also brought regarding the fact that even with the device tested in a vacuum, how "leaky" would be the cavity and still contain air?

Please remind me of this issue when I summarize possible explanations, thanks  :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 04:42 pm
Recapitulation.  Examination of the simplified (we were warned initially "It is a gamble" (http://physicsfromtheedge.blogspot.it/2014/09/emdrives-mihsc.html) ) 1-Dimensional analysis of the EMDrive as per MiHsC quantised inertia based on Unruth radiation [awaiting critical response from Prof. McCulloch]

What is accelerating?   

The only particles that can get close to the required acceleration 
a=8 c^2 / (DiameterOfFlatSurface)  (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html)
(for MiHsC)  are the photons inside the EMDrive cavity (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html)

Where is it accelerating?

Inside the EMDrive microwave cavity

Why is it accelerating? 

Due to the microwave RF operation

When is it accelerating?

During microwave RF operation

What is the acceleration?

a = 2 c^2 / (CavityLength)  (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html)
So the acceleration required for Unruh radiation waves for MiHsC quantised inertia is about 4 times greater than the actual photon acceleration in the cavity, because for the NASA Eagleworks truncated cone, using the radius of the larger flat surface:
(DiameterOfFlatSurface)/(CavityLength) ~ 1   (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html)



EDIT:  @aero is gratefully acknowledged for bringing to my attention a previous error ("Radius" should have read "Diameter).
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 05:27 pm
We must be sure to understand that emdrive doesn't need MiHsC to work if dielectric thrust holds true. MiHsC is an optimization factor. Here on earth in strong gravity MiHsC's effect is essentially zero. Once in microgravity is it helpful. The effect is pretty much nothing otherwise unless you have fancy meta materials.

Some perspective:

http://www.technologyreview.com/view/426281/giant-casimir-effect-predicted-inside-metamaterials/
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 05:29 pm
We must be sure to understand that emdrive doesn't need MiHsC to work if dielectric thrust holds true. MiHsC is an optimization factor. Here on earth in strong gravity MiHsC's effect is essentially zero. Once in microgravity is it helpful. The effect is pretty much nothing otherwise unless you have fancy meta materials.
OK, let's analyze the meaning of "dielectric thrust"

To analyze this concept we need to specify what it entails.  Are you referring to the paper you quoted on chirality of the molecule and the quantum vacuum?  or are you referring to something else?

Thanks
Title: Re: EM Drive Developments
Post by: aero on 10/12/2014 05:31 pm
I've attached a sketch of the Eagleworks cavity with the area ratios. Note that the base is 2.25 times larger than the throat. Does this mean that a particle oscillating between the base the throat at constant speed will impart 2.25 times the momentum on the throat as it does on the base?

Well and good, but if that particle has inertial mass of 1 unit as measured in the laboratory frame, what is it's inertial mass at the base? Of course it is 2.25 times that amount at the throat but what is the reference frame?

It is an important consideration because the answer will tell us how many oscillating particles are needed to produce the measured thrust.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 05:42 pm
We must be sure to understand that emdrive doesn't need MiHsC to work if dielectric thrust holds true. MiHsC is an optimization factor. Here on earth in strong gravity MiHsC's effect is essentially zero. Once in microgravity is it helpful. The effect is pretty much nothing otherwise unless you have fancy meta materials.
OK, let's analyze the meaning of "dielectric thrust"

To analyze this concept we need to specify what it entails.  Are you referring to the paper you quoted on chirality of the molecule and the quantum vacuum?  or are you referring to something else?

Thanks

The perceived importance of the dielectric media to the operation of the device. And yes. Also Dr. White's research on QVT.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 05:46 pm
I've attached a sketch of the Eagleworks cavity with the area ratios. Note that the base is 2.25 times larger than the throat. Does this mean that a particle oscillating between the base the throat at constant speed will impart 2.25 times the momentum on the throat as it does on the base?

Well and good, but if that particle has inertial mass of 1 unit as measured in the laboratory frame, what is it's inertial mass at the base? Of course it is 2.25 times that amount at the throat but what is the reference frame?

It is an important consideration because the answer will tell us how many oscillating particles are needed to produce the measured thrust.

For McCulloch's formula and for Shawyer's formula it is not only the ratio of the large and small flat areas that matter, but instead it is the dimensional difference of their reciprocals:

F = (PowerInput* Q / frequency) *(1/SmallDiameter- 1/LargeDiameter)

So you see, the dimensions of both surfaces enter the equation and not just their ratio

Of course, as it is obvious from the equation, they are inapplicable as the limit of SmallRadius --> 0 is approached, since the force goes to Infinity as that limit (a pointy cone) is approached.

EDIT: Also observe that it is not the surface area and it is not therefore the square of the radius of the flat surfaces that enters the formula but instead is the radius itself.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 05:52 pm
We must be sure to understand that emdrive doesn't need MiHsC to work if dielectric thrust holds true. MiHsC is an optimization factor. Here on earth in strong gravity MiHsC's effect is essentially zero. Once in microgravity is it helpful. The effect is pretty much nothing otherwise unless you have fancy meta materials.
OK, let's analyze the meaning of "dielectric thrust"

To analyze this concept we need to specify what it entails.  Are you referring to the paper you quoted on chirality of the molecule and the quantum vacuum?  or are you referring to something else?

Thanks

The perceived importance of the dielectric media to the operation of the device. And yes. Also Dr. White's research on QVT.

The chirality theory has been already dealt with.  It is not-explanatory due to the extremely small size of the effect predicted (nanometer per second velocity due to 10 Tesla magnetic field) and due to the fact that a 9 inch solid Teflon rod injection molded has practically no overall directionality and chirality.

It is much inferior to Prof McCulloch's theory as an explanatory theory from a quantitative and material viewpoint.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 05:56 pm
We must be sure to understand that emdrive doesn't need MiHsC to work if dielectric thrust holds true. MiHsC is an optimization factor. Here on earth in strong gravity MiHsC's effect is essentially zero. Once in microgravity is it helpful. The effect is pretty much nothing otherwise unless you have fancy meta materials.
OK, let's analyze the meaning of "dielectric thrust"

To analyze this concept we need to specify what it entails.  Are you referring to the paper you quoted on chirality of the molecule and the quantum vacuum?  or are you referring to something else?

Thanks

The perceived importance of the dielectric media to the operation of the device. And yes. Also Dr. White's research on QVT.

The chirality theory has been already dealt with.  It is not-explanatory due to the extremely small size of the effect predicted (nanometer per second velocity due to 10 Tesla magnetic field) and due to the fact that a 9 inch solid rod injection molded has no directionality.

That's fine and all. The key point to get is that modified inertia doesn't make things move. It makes things easier to move. You still have to thrust against something in order to move.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 06:01 pm
We must be sure to understand that emdrive doesn't need MiHsC to work if dielectric thrust holds true. MiHsC is an optimization factor. Here on earth in strong gravity MiHsC's effect is essentially zero. Once in microgravity is it helpful. The effect is pretty much nothing otherwise unless you have fancy meta materials.
OK, let's analyze the meaning of "dielectric thrust"

To analyze this concept we need to specify what it entails.  Are you referring to the paper you quoted on chirality of the molecule and the quantum vacuum?  or are you referring to something else?

Thanks

The perceived importance of the dielectric media to the operation of the device. And yes. Also Dr. White's research on QVT.

The chirality theory has been already dealt with.  It is not-explanatory due to the extremely small size of the effect predicted (nanometer per second velocity due to 10 Tesla magnetic field) and due to the fact that a 9 inch solid rod injection molded has no directionality.

That's fine and all. The key point to get is that modified inertia doesn't make things move. It makes things easier to move. You still have to thrust against something in order to move.

Well, I rather pursue mathematical explanations rather than wordy explanations or wordy refutations. 

Do you have a mathematical formula for what you call "Dr. White's QVT theory" to predict thrust force, so that we can compare it with Prof. McCulloch's formula and Shawyer's formula?
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 06:08 pm
Is there a formula from Dr. White where the material constants and geometrical dimensions of the dielectric appear?
I don't recall any such "dielectric" material dependence in Dr. White's papers
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 06:14 pm
From my knowledge, the formula from Prof. McCulloch's and the formula from Shawyer remain the only formulas that come close to predicting the experimental thrusts in the USA, UK and China experiments.  Everything else is orders of magnitude off.
Title: Re: EM Drive Developments
Post by: MikeMcCulloch on 10/12/2014 06:15 pm
Just a note: MiHsC does predict movement. If you assume conservatn of m'tum, and change m, v changes. See my papers on the flyby anomaly (in MNRAS, 2008) or the Tajmar effect (in EPL, 2011).
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 06:25 pm
Just a note: MiHsC does predict movement. If you assume conservatn of m'tum, and change m, v changes. See my papers on the flyby anomaly (in MNRAS, 2008) or the Tajmar effect (in EPL, 2011).
I agree 100%.  That's my reading of your papers, and you also make that clear in your blog.  It follows from conservation of momentum.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 06:47 pm
From my knowledge, the formula from Prof. McCulloch's and the formula from Shawyer remain the only formulas that come close to predicting the experimental thrusts in the USA, UK and China experiments.  Everything else is orders of magnitude off.

http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

The paper says clearly and provides data that the dielectric is key. The question is how.

Now on the flipside, with no dielectric present, you would get uneven heat of the cavity from fore to aft and some movement of the device. How else could it move? Internal stresses would convert to wall strain. Where is the reaction mass?
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 07:07 pm
From my knowledge, the formula from Prof. McCulloch's and the formula from Shawyer remain the only formulas that come close to predicting the experimental thrusts in the USA, UK and China experiments.  Everything else is orders of magnitude off.

http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

The paper says clearly and provides data that the dielectric is key. The question is how.

Now on the flipside, with no dielectric present, you would get uneven heat of the cavity from fore to aft and some movement of the device. How else could it move? Internal stresses would convert to wall strain. Where is the reaction mass?
OK, but that is an experimental finding by Brady et.al.  NASA presents no theory for it whatsoever.

As far as I know Dr. White has not published in the open literature a mathematical formula to predict "thust" from the dielectric.  The only such theory is the chirality paper that you uncovered, but unfortunately its prediction is several orders of magnitude off and furthermore a 9 inch solid Teflon rod that has been injection molded should have no directional chirality to exploit.

Furthermore, what they state is

<<There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber. The geometry, location, and material properties of this resonator must be evaluated using numerous COMSOL® iterations to arrive at a viable thruster solution. We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust.>>

So, some "very early tests" at a significantly higher frequency with unknown Q.

Given the fact that they have other data showing one experiment given 10% less thrust with 6 times higher input Power, this "dielectric" stuff is not that paramount.

Also, the information from @wembley is that Shawyer no longer uses any dielectric.
Title: Re: EM Drive Developments
Post by: aero on 10/12/2014 07:52 pm
I've attached a sketch of the Eagleworks cavity with the area ratios. Note that the base is 2.25 times larger than the throat. Does this mean that a particle oscillating between the base the throat at constant speed will impart 2.25 times the momentum on the throat as it does on the base?

Well and good, but if that particle has inertial mass of 1 unit as measured in the laboratory frame, what is it's inertial mass at the base? Of course it is 2.25 times that amount at the throat but what is the reference frame?

It is an important consideration because the answer will tell us how many oscillating particles are needed to produce the measured thrust.

For McCulloch's formula and for Shawyer's formula it is not only the ratio of the large and small flat areas that matter, but instead it is the dimensional difference of their reciprocals:

F = (PowerInput* Q / frequency) *(1/SmallRadius- 1/LargeRadius)

So you see, the dimensions of both surfaces enter the equation and not just their ratio

Of course, as it is obvious from the equation, they are inapplicable as the limit of SmallRadius --> 0 is approached, since the force goes to Infinity as that limit (a pointy cone) is approached.

EDIT: Also observe that it is not the surface area and it is not therefore the square of the radius of the flat surfaces that enters the formula but instead is the radius itself.

Quote
What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length (as they are in this case)? Then the inertial mass of the photons would increase towards the cavity's wide end, since more Unruh waves would fit there, since mi=m(1-L/2w), where w is the cavity width.

This looks to me like a 1-D derivation. More Unruh waves would also fit is a larger area, not simply on a 1-D line. The equation would look the same in 2-D, with area replacing width. With a little algebra the equation becomes
F = PowerInput*Q * (Large area-Small area)/(frequency*Large area*Small area)

Not quite what I had before but the area difference is explicit.
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 07:59 pm
I've attached a sketch of the Eagleworks cavity with the area ratios. Note that the base is 2.25 times larger than the throat. Does this mean that a particle oscillating between the base the throat at constant speed will impart 2.25 times the momentum on the throat as it does on the base?

Well and good, but if that particle has inertial mass of 1 unit as measured in the laboratory frame, what is it's inertial mass at the base? Of course it is 2.25 times that amount at the throat but what is the reference frame?

It is an important consideration because the answer will tell us how many oscillating particles are needed to produce the measured thrust.

For McCulloch's formula and for Shawyer's formula it is not only the ratio of the large and small flat areas that matter, but instead it is the dimensional difference of their reciprocals:

F = (PowerInput* Q / frequency) *(1/SmallDiameter- 1/LargeDiameter)

So you see, the dimensions of both surfaces enter the equation and not just their ratio

Of course, as it is obvious from the equation, they are inapplicable as the limit of SmallRadius --> 0 is approached, since the force goes to Infinity as that limit (a pointy cone) is approached.

EDIT: Also observe that it is not the surface area and it is not therefore the square of the radius of the flat surfaces that enters the formula but instead is the radius itself.

Quote
What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length (as they are in this case)? Then the inertial mass of the photons would increase towards the cavity's wide end, since more Unruh waves would fit there, since mi=m(1-L/2w), where w is the cavity width.

This looks to me like a 1-D derivation. More Unruh waves would also fit is a larger area, not simply on a 1-D line. The equation would look the same in 2-D, with area replacing width. With a little algebra the equation becomes
F = PowerInput*Q * (Large area-Small area)/(frequency*Large area*Small area)

Not quite what I had before but the area difference is explicit.

The derivation was indeed 1-dimensional.  Prof. McCulloch and I stated that it was 1-Dimensional at various times.

Concerning "fitting more Unruh waves" in a 2-D derivation , I think that it is not just a question of placing a dependence on area, but one would have to consistently account for and properly derive the dependence on:

1) The tapered section geometry (the angle of the cone)

2) 2-Dimensional mode shapes

in order to be a consistent 2-Dimensional analysis.
Title: Re: EM Drive Developments
Post by: aero on 10/12/2014 08:16 pm
Probably true. The cone half angle is like 1.5/9, opposite/adjacent. That is arctan(1.5/9), or more precisely, 0.1813 radians.

Deriving the 2-D equations looks like a job for Dr. Rodal or Prof. M. :)

I wonder if it will make a difference in the acceleration required to establish the Unruh waves within the cavity?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/12/2014 08:55 pm
New insights page 3.

http://arxiv.org/abs/1012.5264
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/12/2014 09:34 pm
Apparantly the dielectric block in Figure 15. was just the starting point for the COMSOLanalysis iteration
process used prior to assembly to determine the optimal thickness and diameter of the dielectric RF resonator disc located at the small end of the thruster.

From Figure 18:

"Cu Frustrum Test Configuration:
2, 6.25" x 1.06" PE Discs at small End"
Title: Re: EM Drive Developments
Post by: Rodal on 10/12/2014 09:39 pm
Apparantly the dielectric block in Figure 15. was just the starting point for the COMSOLanalysis iteration
process used prior to assembly to determine the optimal thickness and diameter of the dielectric RF resonator disc located at the small end of the thruster.

From Figure 18:

"Cu Frustrum Test Configuration:
2, 6.25" x 1.06" PE Discs at small End"

Fantastic information @notsosureofit   !!!!!

You determined the material:  Polyethylene  (PE)

and the dimensions 6.25" x 1.06"

apparently what they used was 2 (two?) solid disks 6.25 inches in diameter by 1.06 inches thick

There was apparently no inner hole, or they did not record the inner diameter in the report?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/12/2014 10:13 pm
I wonder if it will make a difference in the acceleration required to establish the Unruh waves within the cavity?

Ex-squeeze me?  Grammar alert:

Who or what, with such confidence,  is "establishing" waves which have never been detected before?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/12/2014 10:14 pm
Apparantly the dielectric block in Figure 15. was just the starting point for the COMSOLanalysis iteration
process used prior to assembly to determine the optimal thickness and diameter of the dielectric RF resonator disc located at the small end of the thruster.

From Figure 18:

"Cu Frustrum Test Configuration:
2, 6.25" x 1.06" PE Discs at small End"



Fantastic information @notsosureofit   !!!!!

You determined the material:  Polyethylene  (PE)

and the dimensions 6.25" x 1.06"

apparently what they used was 2 (two?) solid disks 6.25 inches in diameter by 1.06 inches thick

There was apparently no inner hole, or they did not record the inner diameter in the report?

Hmmm, goin to have to think back to the '50s when PE was used between Cu plates as HV capacitors.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/12/2014 10:44 pm
.../...
For McCulloch's formula and for Shawyer's formula it is not only the ratio of the large and small flat areas that matter, but instead it is the dimensional difference of their reciprocals:

(1) F = (PowerInput* Q / frequency) *(1/SmallRadius- 1/LargeRadius)

So you see, the dimensions of both surfaces enter the equation and not just their ratio

Of course, as it is obvious from the equation, they are inapplicable as the limit of SmallRadius --> 0 is approached, since the force goes to Infinity as that limit (a pointy cone) is approached.
.../...

This looks to me like a 1-D derivation. More Unruh waves would also fit is a larger area, not simply on a 1-D line. The equation would look the same in 2-D, with area replacing width. With a little algebra the equation becomes
(2)F = PowerInput*Q * (Large area-Small area)/(frequency*Large area*Small area)

Not quite what I had before but the area difference is explicit.

Dimensional analysis (sanity check)  (Q dimensionless) :
(1) kg m /s² = kg m² /s^3  s /m  OK
(2) kg m /s² != kg m² /s^3  m² s /m² /m² = kg /s²   the expression lacks a meter unit somewhere

Regarding (1) and divergence when SmallRadius tends to 0, regardless of the soundness of the backing explanation (I just plain don't get it) the scaling behaviour could be interpreted as :
- the smaller both radius (that is, the thinner the cavity, at constant LargeRadius/SmallRadius) the stronger the force (linearly). That sounds strange but :
- if we consider that the wavelength must fit into the SmallRadius then the thinner the cavity, the higher must be the frequency, so as to cancel the increase in thrust from a thinner design. This is less strange : at constant power and Q, a thinner cavity, half radius from a given design, could yield same thrust only by doubling the frequency.

A cone (SmallRadius=0) would be no more thrusting than truncated cone at SmallRadius ~ c / frequency (ie. 15.8 cm at 1.9GHz). That is c would appear somewhere in the formula as to asymptotically limit the divergence when going thinner...
But I don't understand the backing theory, this is just formal frobnicating.
Title: Re: EM Drive Developments
Post by: aero on 10/12/2014 11:05 pm
Quote
Dimensional analysis (sanity check) :
(1) kg m /s² = kg m² /s^3  s /m  OK  (Q dimensionless)
(2) kg m /s² != kg m² /s^3  m² s /m² /m² = kg /s²   the expression lacks a meter unit somewhere

Yes. By replacing length by area, I introduced an extra "meter." Then I multiplied top and bottom by a*b and factored. That divides out the m^2 so I lost  both "meters". I guess that's another reason why a formal 2-D derivation is needed.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/13/2014 12:59 am
From my knowledge, the formula from Prof. McCulloch's and the formula from Shawyer remain the only formulas that come close to predicting the experimental thrusts in the USA, UK and China experiments.  Everything else is orders of magnitude off.

http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

The paper says clearly and provides data that the dielectric is key. The question is how.

Now on the flipside, with no dielectric present, you would get uneven heat of the cavity from fore to aft and some movement of the device. How else could it move? Internal stresses would convert to wall strain. Where is the reaction mass?

With @notsosureofit finding that the dielectric was PE, 1 inch thick, the chirality theory is back into consideration due to polyethylene being able to have spherulites melt-crystallised.  (I still have reservations about the amount of chirality in commonly available samples)

http://www.esrf.eu/UsersAndScience/Publications/Highlights/2011/scm/scm4

(http://www.esrf.eu/files/live/sites/www/files/UsersAndScience/Publications/Highlights/2011/figures/figure_58_HL2011.jpg)

Now if I remember right, them capacitors were bolted into stacks (stack?) for an early accelerator in the Cambridge (MA) area, and when I saw them they showed me holes in the ceiling where the bolts had been blown up thru.  I don't remember if it was on charge or discharge but there was significant force involved.  (I used oil caps)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/13/2014 07:29 am
"Regardless of the mechanisms that might be entertained with regard to
"propellantless" or "field" propulsion of a spaceship, there exist certain constraints that
can be easily overlooked but must be taken into consideration. A central one is that,
because of the law of conservation of momentum, the center of mass-energy (CM) of an
initially stationary isolated system cannot change its position if not acted upon by outside
forces. This means that propellantless or field propulsion, whatever form it takes, is
constrained to involve coupling to the external universe in such a way that the
displacement of the CM of the spaceship is matched by a counteracting effect in the
universe to which it is coupled, so as not to violate the global CM constraint. Therefore,
before one launches into a detailed investigation of a proposed propulsion mechanism it
is instructive to apply this principle as an overall constraint to determine whether the
principle is violated." You have to thrust against something.

I really need you guys to take the above statement seriously. We also must not forget about hidden momentum. We need to make sure we are doing real science here.

http://gr.physics.ncsu.edu/files/babson_ajp_77_826_09.pdf

We, collectively as a group, need to make sure we are wearing our scientist, mathematician, and engineer hats equally. Each of us have more or less of these skills. Otherwise the cake is a lie.

Engineers understand that in any closed system, the way energy is conserved is by converting that energy to another form or by doing work. There has to be a path for that work to happen.

The potential energy of a hairspray can doesn't make it shoot across the room, even if you heat it up on one end. You have to expel that potential energy out the nozzle to convert it to kinetic energy.

Otherwise, the potential energy of the system remains isolated within the closed system. There has to be a path for this to happen.

In closing, there are only 3 way for emdrive to thrust with just a flooded rf cavity alone.

1. Leaking heat to the rest of the universe. (Shawyer)
2. Leaking magnetic influence to the rest of the universe.(like a space tether) (Shawyer)
3. In the absence of ALL other forces (like in a sweet spot between galaxies) tiny motion because of modified inertia.

You have to find a way to thrust against something else. That is the holy grail.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/13/2014 08:13 am
No.
We do not know what happens.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/13/2014 08:45 am
For you guys who like to tinker, here's pointers on how to build your own torsion balance at home:

https://www.fourmilab.ch/gravitation/foobar/


Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/13/2014 12:20 pm
Fine:  Go ahead and make me learn something new every day (http://www.urbandictionary.com/define.php?term=fnarr).  See if I care.  Hope y'all are happy now.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/13/2014 12:34 pm
This means that propellantless or field propulsion, whatever form it takes, is
constrained to involve coupling to the external universe in such a way that the
displacement of the CM of the spaceship is matched by a counteracting effect in the
universe to which it is coupled, so as not to violate the global CM constraint.

Ipso fatso, any copper clad "new universes" are not all that new.  There's some fan clubbing going on in this thread, and so IMO, language should be a bit more carefully considered; "otherwise the cake is a lie".

Put another way, propellantless propulsion is not as easy as falling off a piece of cake.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/13/2014 12:50 pm
This means that propellantless or field propulsion, whatever form it takes, is
constrained to involve coupling to the external universe in such a way that the
displacement of the CM of the spaceship is matched by a counteracting effect in the
universe to which it is coupled, so as not to violate the global CM constraint.

Ipso fatso, any copper clad "new universes" are not all that new.  There's some fan clubbing going on in this thread, and so IMO, language should be a bit more carefully considered; "otherwise the cake is a lie".

Put another way, propellantless propulsion is not as easy as falling off a piece of cake.

http://www.youtube.com/watch?v=qdrs3gr_GAs

IF the science gets done, you get a neat thruster (cake), for the people who are still alive after us. IF, otherwise the cake is a lie.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/13/2014 01:17 pm
Excellent song!  Mucho thankso!
Title: Re: EM Drive Developments
Post by: Stormbringer on 10/13/2014 01:53 pm
you should have used a vocaloid cover of that song. a robot singing a robot's song :)

portal II End Credit Song:  https://www.youtube.com/watch?v=mGkieQKooe4
Title: Re: EM Drive Developments
Post by: Rodal on 10/13/2014 03:19 pm
The "self accelerating box paradox" due to Unruh radiation, has a rich history going back to this original publication by Unruh himself in 1982:

William G. Unruh and Robert M. Wald, Acceleration radiation and the generalized second law of thermodynamics,Phys. Rev. D 25, 942 – Published 15 February 1982

http://journals.aps.org/prd/abstract/10.1103/PhysRevD.25.942

_____________________________


This is a popular account, included here with special regard and affection towards kernosabe and his clamor of "non capisco".  It is written by popular science writer Paul Davies, as it appeared in New Scientist Jan 14, 1982 (please notice that I went through the trouble and time to shorten the url, so as not to screw up the formatting in this thread  :)  ) :

http://goo.gl/w7N6ir

_____________________________


For objective balance, this is a more recent paper on the "self accelerating box paradox," with a different take than Unruh and Wald's paper regarding the thermodynamics issue:

Donald Marolf, Rafael Sorkin, Perfect mirrors and the self-accelerating box paradox, Phys.Rev. D66 (2002) 104004

http://arxiv.org/abs/hep-th/0201255

__________________________

Title: Re: EM Drive Developments
Post by: Mulletron on 10/13/2014 03:26 pm
Ah yes, the Semmelweis Reflex.

Let me know when you see a tin can move all by itself here on Earth. Or the galaxy.

You're basically saying that I could go up to one of my satellite antennas right now and weld the feedhorn shut on it and have a new form of propulsion.

It is as simple as this. The casimir effect of a copper can is basically zero. It will only accelerate all by itself if there is no other force acting on it. Like between galaxy clusters if you're lucky. Wrap it in new fangled meta materials; you know, the ones that make things appear invisible, then you can have your paradox box. Maybe. Even then you will have to strap a fan on it or do something to provide thrust in order to overcome gravity.

That isn't what was in the test chamber.

I clearly mentioned in the summary how it could move all by itself by virtue of its shape, IN DEEP SPACE.

Perspective is everything.

Put MiHsC in the proper context.

As John so eloquently put it, "Ipso fatso, any copper clad "new universes" are not all that new."

Love you guys  ;D


Lastly, Shawyer's latest theory paper, says all throughout that it has dielectric at the small end.

http://emdrive.com/theorypaper9-4.pdf

Page 6. "dielectric-filled section at the smaller end of the taper"

Title: Re: EM Drive Developments
Post by: Rodal on 10/13/2014 04:35 pm
Again (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269787#msg1269787), acceleration due to a change of inertia follows from the basic principle of conservation of momentum.  There is no basic principle that for something to move "thrust must be involved" in Physics.  Physics has conservation laws.  Conservation of momentum is one of the basic laws of Physics, obeyed in General Relativity as well as in Quantum Mechanics.  As we know from Physics and Engineering the relevant consideration is how such an acceleration (and resulting force) may  compare with other accelerations (and forces) to produce a net acceleration (or force). 
Scientific criticism may address thermodynamic considerations, information theory, and the arrow of time, for example, but never "thrust must be involved for something to move", there is no such principle in physics.

The language of physics is conservation laws, virtual work principles and mathematical equations and not words/and/or/music like "the cake is a lie" or "you."
Title: Re: EM Drive Developments
Post by: aero on 10/13/2014 04:52 pm
Someone once famously said. "For every action their is an equal and opposite reaction."

We know what the reaction was, (the measured thrust force), we're trying to figure out what the action was. We are going about it by eliminating everything that the action was not. Once all other candidate actions are eliminated, the remaining candidate must be true no matter how improbable.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/13/2014 04:53 pm
Again (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269787#msg1269787), acceleration due to a change of inertia follows from the basic principle of conservation of momentum.  There is no basic principle that for something to move "thrust must be involved" in Physics.  Physics has conservation laws.  Conservation of momentum is one of the basic laws of Physics, obeyed in General Relativity as well as in Quantum Mechanics.  As we know from Physics and Engineering the relevant consideration is how such an acceleration (and resulting force) may  compare with other accelerations (and forces) to produce a net acceleration (or force). 
Scientific criticism may address thermodynamic considerations, information theory, and the arrow of time, for example, but never "thrust must be involved for something to move", there is no such principle in physics.

The language of physics is conservation laws, virtual work principles and mathematical equations and not words/and/or/music like "the cake is a lie."

Quote
"There is no basic principle that for something to move "thrust must be involved" in Physics."
Except Newton's laws of motion........
Without a means to thrust. It is moving due to entropy. Because it is not a perfectly isolated system. It is radiating heat.

The way you describe it, violates mechanics.

Translation, not new science.

Regardless of the internal stresses an object is experiencing, it must still experience a force in order to change acceleration.

The Hubble scale Casimir effect on the inertial bias of a copper can here on Earth is essentially zero.

One can choose to ignore the laws of motion and the laws of thermodynamics if they wish. The laws are only suggestions........... ::) If one does, I can offer them no hope.





Title: Re: EM Drive Developments
Post by: Rodal on 10/13/2014 04:59 pm
Wish us would address science and engineering without using words like "you" and "I".

The personalization of what should be scientific and engineering arguments is the reason why academics stay away from internet forums.  Such personalization degrades the search for truth. There is no "you" and "I" in mathematical formulas or in Physics.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/13/2014 11:39 pm
We have covered quite a few concepts in this thread.  One or two looked almost promising for a time, yet...

Doctor White and the other researchers involved have been looking into propellentless drives of one sort or another for decades.  Towards the end of the paper that tripped off this thread, the Eagleworks team stated they were working on a dramatically improved version of this propellentless drive, one capable of a thrust of 0.1 Newton's in a vacuum.

Everything we have looked at here falls at least somewhat short of even the far more modest results from the current Eagleworks mechanism. 

So, assume this next Eagleworks mechanism performs as advertised, or close enough to it - 0.1 Newton's of thrust, in a vacuum, with the error sources accounted for.  Does this mean the 'unworkable' theory the Eagleworks team is using is correct?  Or is there some way the idea's considered here could be scaled up and/or combined to account for this?
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/13/2014 11:59 pm
At this stage of the game, I think we're all hungering for that "Eureka!" moment that will turn the (dime a dozen) ideas of non-propellant propulsion into a practical matter of engineering. Until such a demonstrably functional device can be built, EM drives will remain a pipe-dream. There's good effort being spent here on mathematics and juggling theories, but for now, it's all sizzle. I don't know about you, but I could really go for some steak.
Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 12:30 am
MiHsC prediction (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html )

-no fudge factors
-no free parameters
-a bare minimum of input data
-minimum idealization of actual geometry (actual EMDrive is not exactly a truncated cone)

Predicted Force =(P*Q/f)*((1/Dsmall)-(1/Dbig))

where:

P=power input
f=frequency
Q = quality factor  (http://en.wikipedia.org/wiki/Q_factor)
Dbig    = Diameter of larger flat surface of truncated cone EM Drive (the base of the truncated cone)
Dsmall = Diameter of smaller flat surface of truncated cone EM Drive (the smaller plane parallel to the base)


Experiment                    Dbig   Dsmall          Q       Power in      Freq'      Prediction        Observed
                                     cm        cm                      Watts         GHz       milliNewton      milliNewton
-------------------------------------------------------------------------------------------------------------
Shawyer (2008) a          16         8            5900     850          2.45         12.8          16
Shawyer (2008) b          28         4          45000    1000         2.45       394             80-214
Juan (2012) TE011        16/28    8/4       32000    1000         2.5           80-274    214
Juan (2012) TE012        16/28    8/4       50000    1000         2.45       128-437    315
Brady et al. (2014) a      24.75  16.5         7320    16.9          1.933         0.129         0.0912
Brady et al. (2014) c       "           "           22000     2.6          1.88           0.061         0.0554


The following experiment is very anomalous:

Brady et al. (2014) b       "           "           18100   16.7          1.937         0.315         0.0501

because:

1) An increase in Q from Brady et al. (2014) a, from  Q=7320 to Q=18100 (a factor 2.5 times) results in a smaller experimentally measured force (practically 50% of the force with the much lower Q)

2) An increase in Power Input from Brady et al. (2014) c, from 2.6 Watts to 16.7 Watts (a factor 6 times) results in a smaller experimentally measured force (10% smaller)

3) It was conducted at a frequency only 0.3% different than Brady et al. (2014) a


The prediction vs. observed experimental values is over a range of power of ~400 times and a range of force of ~6000 times (from 0.0000554 Newtons to 0.315 Newtons)


Links:

Shawyer, R., 2008. Microwave propulsion - progress in the emdrive programme (http://www.emdrive.com/IAC-08-C4-4-7.pdf)

Yang Juan,Yang Le,Zhu Yu,Ma Nan, Journal of Northwestern Polytechnical University Vol 28 No 6 Dec 2010 (http://www.emdrive.com/NWPU2010translation.pdf)

Brady, D., et al., 2014. Anomalous thrust production from an RF test device measured on a low-thrust torsion pendulum. Conference proceedings, see Table page 18. (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf)

(http://eclinik.files.wordpress.com/2014/08/nasa-space-drive-emdrive-si.jpg?w=672&h=372&crop=1)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/14/2014 01:26 am
As John so eloquently put it, "Ipso fatso... "

Love you guys! 

Hey!  We should all get together over marshmallows and a campfire and sing a couple of rounds of "Kumbayaaaa".

But seriously, this has been one of the most enjoyable and learning intensive threads I've been in over the last four or five years.

Still, I don't think that there's a there there, in the sense of a pragmatically adaptable propulsion effect.  The forces mentioned all seem so small, and rely on the most obscure of references to known physics.

Which is not all that many words, but still, is only a buncha words:

The language of physics is conservation laws, virtual work principles and mathematical equations and not words/and/or/music like "the cake is a lie" or "you."

While it is true that "you" and "I" have little known effect on the pre-existing and yet to be discovered laws of physics, it is also true that only you and I can discuss these things.  Fo zample:

I don't think this "skin effect" at the wall of the copper frustrum amounts to much of anything of any utility.

Assume an asymmetric resonant cavity, with microwave photons bouncing around inside it. They carry a force F=2P/c, where P is power and c is the speed of light, due to the inertial mass of light (light does have an inertial mass, or Solar sails wouldn't work). Including the Q factor (number of photon 'bounces') gives F=2PQ/c. (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html)

So F=2P/c and F=2PQ/c.  with Q being the number of photon bounces.  OK.  There's a linear relationship between the force you get and the number of photon bounces, presumably related to the power you feed the device.  But remember that the Mass (m) of those photons is pretty darn small. 

Solar sails do work, but not at the scale and mass of the copper frustrum.  Solar sails are football fields in size and don't weigh hardly anything.   Like, 13,000 square feet and 70 pounds (http://www.popsci.com/technology/article/2013-01/nasa-will-launch-largest-solar-sail-solar-system-has-ever-seen-2014)

So I'm struggling with the pragmatic utility of the setup.  If an anomalous thrust is developed based on these masses, it ain't gonna be all that much.  I haven't gotten to considering the Unruh waves yet, but, speaking of words, I'm choking on this:

"What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length..."  Why izzat different from asking, what if pigs had wings?
Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 02:00 am
Quote
The sciences do not try to explain, they hardly even try to interpret, they mainly make models. By a model is meant a mathematical construct which, with the addition of certain verbal interpretations, describes observed phenomena. The justification of such a mathematical construct is solely and precisely that it is expected to work.

The polymath of the 20th Century:

John von Neumann

wrote the above in his essay "Method in the Physical Sciences", in The Unity of Knowledge (1955), ed. L. G. Leary (Doubleday & Co., New York), p. 157

(http://upload.wikimedia.org/wikipedia/commons/5/5e/JohnvonNeumann-LosAlamos.gif)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/14/2014 02:02 am


"What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length..."  Why izzat different from asking, what if pigs had wings?

Maybe not a Hubble horizon, but it affects the local impedance of the space around it.  Look at the scattering cross-section as a function of wavelength.
Title: Re: EM Drive Developments
Post by: aero on 10/14/2014 02:02 am
Quote
"What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length...
  Why izzat different from asking, what if pigs had wings?[/quote]

The difference is that he goes ahead and predicts mathematically how well the "pigs" could fly. Then he compares his "flying pigs" to three cases where some strange flying thing was seen, and lo and behold, those strange flying things are flying just about the way the mathematics predicted that pigs with wings could!

"Except for the one case where we could speculate that the pig was injured."
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/14/2014 02:15 am
Quote
Quote
"What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length...
  Why izzat different from asking, what if pigs had wings?

The difference is that he goes ahead and predicts mathematically how well the "pigs" could fly. Then he compares his "flying pigs" to three cases where some strange flying thing was seen, and lo and behold, those strange flying things are flying just about the way the mathematics predicted that pigs with wings could!

"Except for the one case where we could speculate that the pig was injured."

It's enough to drive interest, that's for sure! Still, I really need to see the theory applied to new experiments to remove doubts about the physics of EM drives. Since those experiments are already being performed, I guess it's time to hurry up and wait. :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 02:25 am
Quote
Quote
"What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length...
  Why izzat different from asking, what if pigs had wings?

The difference is that he goes ahead and predicts mathematically how well the "pigs" could fly. Then he compares his "flying pigs" to three cases where some strange flying thing was seen, and lo and behold, those strange flying things are flying just about the way the mathematics predicted that pigs with wings could!

"Except for the one case where we could speculate that the pig was injured."

It's enough to drive interest, that's for sure! Still, I really need to see the theory applied to new experiments to remove doubts about the physics of EM drives. Since those experiments are already being performed, I guess it's time to hurry up and wait. :)
@RotoSequence, I completely agree with you.  That's exactly what I was taught at MIT.  The "model" stands only as long as experiments verify it. The "model" falls immediately when experiments fail to verify it.


The model falls if another model with the same number or smaller number of parameters does a better job at explaining the experimental data.

Excellent wording "It's enough to drive interest.  We need to see the theory applied to new experiments to remove doubts about the physics of EM drives"

I couldn't have said it better.  The model has to be further explored regarding a larger range of Q, a much larger range of frequency, and a much larger geometrical range.  The power range (a factor of 6000 from minimum to maximum power modeled) is already very interesting.
Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 02:33 am
The next step that could be done is:

are there other physical models that result in the same (or better) formula to explain the experimental data ?


They don't need to be physical models that make the EMDrive fly, they can be physical models that explain the experimental data as an artifact.  For example the "magnetic" explanation as an artifact (and  other explanations ) are also expected to be related to the input power.  But the trick is to find other physical explanations that predict all these data as well or better.  The interesting thing is the dependence on Q and frequency, and on the inverse of the flat surface diameters.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/14/2014 02:43 am
Quote from: McCulloch
"What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length...
 

Quote from: JF
Why izzat different from asking, what if pigs had wings?

The difference is that he goes ahead and predicts mathematically how well the "pigs" could fly. Then he compares his "flying pigs" to three cases where some strange flying thing was seen, and lo and behold, those strange flying things are flying just about the way the mathematics predicted that pigs with wings could!

That's too facile an explanation, particularly when depending upon the hypothetical Unruh effect (http://en.wikipedia.org/wiki/Unruh_effect).

Without being snarky, but trying to follow the winged pig analogy a mite further, it's like saying:  Let's assume these dimensions for the Unruh pig wings, and lo, they accomodate the reported data.  Remember too, that no "strange flying thing was seen", by the community in general.  What has happened so far is only that some strange flying thing was thought to be seen.

Plus, typically Unruh pig wings are only found in integral divisions of the friggin' Hubble distance, a huge number of meters.  We have some experimentors claiming that there is cupric Unruh pig's wing effect at the boundary of a very small pig's wing of a specific geometry.  McCulloch the theoretician acknowledges this: "What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length"

No actual pigs were harmed in this analogy.

Q = quality factor

Which sounds like a tunable parameter, by this wording.  McCulloch calls the Q factor, the "number of photon 'bounces'", so now I'm having a terminology tantrum.  I thought that tunable parameters, aka 'fudge factors' were frowned upon.  So what is it, quality? or a specific number of 'bounces' which seem to be linearly related to the power input?

This device, should it work as hypothesized, has no pragmatic value when the power going in is compared to the thrust that they think they get out of the device. 
Title: Re: EM Drive Developments
Post by: aero on 10/14/2014 02:56 am
Q is defined as:

Q = stored energy/energy lost per cycle.

Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 03:00 am
Q is defined as:

Q = stored energy/energy lost per cycle.

Yes, that is one of several (completely identical to each other definitions of Q). A standard, universally accepted definition for all kinds of mechanical vibrations and electromagnetic oscillations to characterize damping.  A very well defined mathematical variable, that is completely independent from McCulloch's theory.  All three laboratories that did the testing (in USA, UK and China) were completely aware of the importance of Q and went through the trouble of measuring and reporting Q (the table of values contains the experimentally reported values of Q, and those were the values used in the formula for predictions, without any changes).
Title: Re: EM Drive Developments
Post by: Mulletron on 10/14/2014 11:26 am
Until it is recognized that conservation of momentum has to be satisfied both locally and globally, no more progress can be made. One cannot pick or choose which.

The report also clearly stated the importance of the dielectric.

Page 18 clearly shows that thrust does not scale with Q.

Ignoring data and physical law puts wings on pigs.



Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 02:09 pm
The following study (and similar studies on the other experimental variables) is trivial to do, but I enclose it as a service to readers that may not have had the time to do a statistical exploration of the data, to notice the significance of the variables and McCulloch's formula.

The language of engineers and scientists is mathematical formulas, numbers, graphs and not words. Professional engineering and scientific discourse uses such exploration of data and not words like "pigs", "the cake is a lie", and personalization words like "you" and "I".

I enclose a plot of experimental and predicted Q, for the EMDrive experiments conducted in the US, UK and China, and reported in my my last post with data (please refer to:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1270264#msg1270264  ).

The horizontal axis shows the experimentally measured Q.

The vertical axis shows the predicted Q from McCulloch's formula (inverted to express Q as a function of the other variables), using experimentally-measured forces, and expressed as follows:

PredictedQ = (ExperimentalForce)*Frequency/((PowerInput)*(1/Dsmall-1/Dbig))

It is obvious from the plot that:

1) There is a significant experimental dependence on Q, the R^2 value is statistically significant: 81% (and this is including the outlier data: the very anomalous test reported by Brady et.al at a frequency of 1.937 GHz). 

2) The actual Q dependence is linear as predicted by McCulloch's formula, as shown by the least squares formula shown in the box.  It is certainly linear within the (obvious from plotting the data) experimental uncertainty in the measurements.

3) The fact that the predicted curve (in red) is off by a factor of ~34%, as I have previously addressed in Prof. McCulloch's blog is expected, since McCulloch's formula is a 1 Dimensional simplification of the full 3-D Modified Inertia formulation: as the simplified formula neglects the Unruh wave contribution from the sides of the cone (the simplified formula only uses the flat areas into consideration).



Concerning the dielectric:

Brady et. al. state is

<<There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber. The geometry, location, and material properties of this resonator must be evaluated using numerous COMSOL® iterations to arrive at a viable thruster solution. We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust.>>

So, some "very early tests" at a significantly higher frequency with non-reported Q.  Not much one can do regarding Q with this statement for which Q is not reported (we don't know whether it was even measured for this case).

Given the fact that they have outlier data (included in the attached plot and taken into account to compute R^2) showing one experiment given 10% less thrust with 6 times higher input Power, this "dielectric" statement with an unreported Q is not that relevant.

Also, the information from @wembley is that Shawyer no longer uses any dielectric.  Shawyer's started using ferrites, then he switched to dielectric materials and according to the latest information he no longer uses dielectric.  Shawyer's reference to dielectric is several years old.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/14/2014 02:42 pm
Just for fun, let's say the prediction curve is absolutely accurate and based on 70 years of experience w/ copper waveguides and resonators.  Then the difference w/ these tapered chambers represent a loss of power which is going somewhere ???
Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 02:45 pm
Just for fun, let's say the prediction curve is absolutely accurate and based on 70 years of experience w/ copper waveguides and resonators.  Then the difference w/ these tapered chambers represent a loss of power which is going somewhere ???

Yes, good point.  I also noticed that early on.  My take on that is the following:

The fact that the predicted curve (in red) is off by a factor of ~34%, as I have previously addressed in Prof. McCulloch's blog is expected, since McCulloch's formula is a 1 Dimensional simplification of the full 3-D Modified Inertia formulation: as the simplified formula neglects the Unruh wave contribution from the sides of the cone (the simplified formula only uses the flat areas into consideration).

The simplified 1 Dimensional formula of McCulloch's full theory is obviously an approximation since it leads to an infinite predicted force for the diameter of the smaller flat surface going to zero.  So the 1D formula overpredicts the force (because it does not take into account the Unruh wave contribution from the curved surface of the cone).
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/14/2014 02:48 pm
Just for fun, let's say the prediction curve is absolutely accurate and based on 70 years of experience w/ copper waveguides and resonators.  Then the difference w/ these tapered chambers represent a loss of power which is going somewhere ???

Yes, good point.  I also noticed that early on.  My take on that is the following:

The fact that the predicted curve (in red) is off by a factor of ~34%, as I have previously addressed in Prof. McCulloch's blog is expected, since McCulloch's formula is a 1 Dimensional simplification of the full 3-D Modified Inertia formulation: as the simplified formula neglects the Unruh wave contribution from the sides of the cone (the simplified formula only uses the flat areas into consideration).

It would be nice to have the COMSOL prediction for these chambers.

Edit:  Forgot they use a simplified chamber wall.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/14/2014 02:49 pm
Just for fun, let's say the prediction curve is absolutely accurate and based on 70 years of experience w/ copper waveguides and resonators.  Then the difference w/ these tapered chambers represent a loss of power which is going somewhere ???

Yes, good point.  I also noticed that early on.  My take on that is the following:

The fact that the predicted curve (in red) is off by a factor of ~34%, as I have previously addressed in Prof. McCulloch's blog is expected, since McCulloch's formula is a 1 Dimensional simplification of the full 3-D Modified Inertia formulation: as the simplified formula neglects the Unruh wave contribution from the sides of the cone (the simplified formula only uses the flat areas into consideration).

The simplified 1 Dimensional formula of McCulloch's full theory is obviously an approximation since it leads to an infinite predicted force for the diameter of the smaller flat surface going to zero.  So the 1D formula overpredicts the force (because it does not take into account the Unruh wave contribution from the curved surface of the cone).

Which, I might point out, is a number of words, and not an actual 3d formula which accurately portrays the contribution of the  hypothetical Unruh wave.

Which is not saying that I already understand that 3D equation.  I do understand the 1D equation.  Up to a point.  Not the one at the top of my head, you wisecracks.
Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 02:54 pm
Engineers and Scientists understand the usefulness of 1 Dimensional approximation of fully 3D theories to obtain closed-form solutions.  This is understood by any structural engineer using beam equations instead of fully 3-D equations that are unsolvable without numerical analysis.  The usefulness of closed-form solutions is understood in fluid mechanics, heat transfer, solid mechanics, and just about every engineering and scientific discipline.  The usefulness of closed-form solutions (always an approximation of full 3D solutions of course) is certainly understood by Aerospace Engineers.
Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 06:19 pm
I enclose plots of experimental and predicted frequency, for the EMDrive experiments conducted in the US, UK and China, and reported in my my last post with data (please refer to:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1270264#msg1270264  ).

The horizontal axis shows the experimentally measured frequency.

The vertical axis shows the predicted frequency from McCulloch's formula (inverted to express the frequency as a function of the other variables), using experimentally-measured forces, Q, power input and geometry, and expressed as follows:

PredictedFrequency =(PowerInput)*Q*(1/Dsmall-1/Dbig) /  (ExperimentalForce)

It is obvious from the plot that:

1) The experiments in the US, UK and China did not peform a satisfactory exploration of frequencies.  Basically only two frequency ranges have been explored: ~1.9 GHz in the US and ~2.5 GHz in the UK and China

2) The uncertainty experimental bars are very large and they overwhelm the very small frequency range that was explored.

3) There is a clear statistical outlier (Brady et.al. at 1.937 GHz) that I have repeatedly pointed out.  The fact that this is a statistical outlier is evident from the plot.

4) The data with the statistical outlier included gives a very poor R^2 = - 12%.  Essentially, including the statistical outlier indicates that the uncertainty overwhelms the power to conclude anything concerning frequency dependence.

5) Considering the data without the outlier gives a weak statistical dependence: R^2 = 22%.  Essentially inversely proportional to the frequency, as predicted by McCulloch, but again there is not enough statistical data to make any statistical conclusion regarding frequency dependence.

6) The fact that the predicted curve (in red) is below the experimental curve, as I have previously addressed in Prof. McCulloch's blog is expected, since McCulloch's formula is a 1 Dimensional simplification of the full 3-D Modified Inertia formulation: as the simplified formula neglects the Unruh wave contribution from the sides of the cone (the simplified formula only uses the flat areas into consideration), hence it overpredicts the force.  Since frequency and force appear as inverse to each other, an overprediction of force means an undeprediction of frequency based on experimentally measured force.

7) A very important issue is the fact that resonance amplitude is a very nonlinear function of frequency.  Besides this being expected, such resonance amplitude nonlinear dependence on frequency is shown in the S22 plots.  Hence it is not surprising that a formula that is inversely proportional to frequency cannot possibly reflect the huge changes in amplitude resonance emanating from small changes in frequency (for example for Brady et.al. at 1.88, 1.933 and 1.937 GHz), particularly when experimenters deliberately chose to conduct their experiments at frequencies close to resonance.

Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 06:43 pm
Also, one can follow the pertinent arguments brought up by @aero concerning the axial wavelength, regarding frequency dependence in the simplified formula: http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html  .

Thanks @aero for continuing a professional engineering/scientific exploration of the EMDrive experimental data :)
Title: Re: EM Drive Developments
Post by: aero on 10/14/2014 08:13 pm
I'm not sure what your frequency-frequency curves signify.

Based on this from Prof. M:

Quote
What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length (as they are in this case)? Then the inertial mass of the photons would increase towards the cavity's wide end, since more Unruh waves would fit there, since mi=m(1-L/2w), where w is the cavity width. The force carried by the photons then increases by this factor as they go from the narrow end (width w_small) towards the wide end (width w_big). The force difference between ends is

 dF = (PQ/c)*((L/w_big)-(L/w_small)) = (PQ/f)*((1/w_big)-(1/w_small)).

From this it is clear that L is the Unruh wave length and that the cavity walls act like a Hubble horizon. Therefore L/c is the Unruh frequency. Resonance of the Unruh waves within the cavity is not required, they are driven by the RF waves which do resonate however. Therefore, acceleration within the cavity walls is driven by the RF waves which in turn drive the Unruh waves.

But the Unruh frequency need not be the same as the RF frequency. They need only be some frequency that is sustained by the cavity height and the RF wave induced accelerations.  I have calculated that the cavity height constrains wavelength, lamda, to 6, 9 or 18 inches. (2d = n lamda) so lamda = 2d/n. Here d is the cavity height = 9 inches so lamda = 18(n=1), = 9(n=2) = 6(n=3).

But there is another important consideration. That is that within the big and small end of the cavity, the Unruh waves reflections are separated in time by d/c and by the choice of the driving RF frequency there are acceleration pulses to driving Unruh waves just exactly in synchronization with that time difference or wavelength which is 9 inches. I don't know of any reason that the Unruh waves would prefer a higher frequency, shorter wavelength.

I can't justify the Unruh waves selecting a higher energy state when there is a lower energy state available.
Title: Re: EM Drive Developments
Post by: Rodal on 10/14/2014 08:16 pm
I received the attached e-mail from Robert Ludwick that explains the anomalous outlier in NASA's Brady et. al. report as well as bringing up excellent questions regarding the curious choice of testing frequencies pursued by NASA's Brady et.al. (curious since not only did they have COMSOL Finite Element calculations of resonance but they actually had the S22 plot for actual measured resonance) and their use of a Voltage Controlled Oscillator (VCO).

This is an outstanding contribution by Robert Ludwick that I reproduce in its entirety.  A professional examination of the data, that serves to clarify and understand it.

I added Bolding and color for emphasis [not present in his original e-mail] to the sections that I found most attention calling.



From:   Robert Ludwick
Sent:   Tuesday, October 14, 2014 12:27 PM
To:   [email protected]
Subject:   Re: EM Drive Developments « Reply #2082 on: Today at 12:30 AM

Hello Dr. Rodal,

I apologize for using email for this, rather than the forum, but I am not a
member and can’t post there—I think.

I was reading the ongoing discussion re Shawyer’s EmDrive and came across the
subject comment by you.

At the end of the data table showing the measured thrust vs the MiHsC thrust
prediction, you said this:


"The following experiment is very anomalous:

Brady et al. (2014) b       "           "           18100   16.7     1.937         0.315         0.0501

because:

1) An increase in Q from Brady et al. (2014) a, from  Q=7320 to Q=18100 (a
factor 2.5 times) results in a smaller experimentally measured force
(practically 50% of the force with the much lower Q)

2) An increase in Power Input from Brady et al. (2014) c, from 2.6 Watts to
16.7 Watts (a factor 6 times) results in a smaller experimentally measured
force (10% smaller)

3) It was conducted at a frequency only 0.3% different than Brady et al.
(2014) a"

First of all, I don’t know what Brady was using as a source.

That said, there are several trivial explanations for the anomalous test
results (all of which Brady may have already accounted for—I don’t know). 

The bandwidth of the widget is Resonant Frequency/Q. 
If you increase the Q the bandwidth decreases. 


Using the data provided for the three Brady tests:

Freq (MHz)        Q             Power (W)   Bandwidth (MHz)    Bandwidth (% of Test Freq)

1933         7320      16.9           .264                       0.014

1880         22000      2.6           .085                      0.0045

1937      18100      16.9           .107                      0.0055               

(The quoted dimensions for the thruster were the same for all three tests, so
why was the test frequency varied by +/- 1.5%, when the broadest bandwidth,
based on the measured Q, was +/- 0.007 %?)


NOTE BY J.RODAL: And for the anomalous test  specifically, why did Brady et.al. change the test frequency from 1933 GHz to 1937 GHz, which is only a 0.2% change in frequency or just +/- 0.1%, when the bandwith was 0.0055% ?

If Brady was using a free running VCO, ’tuned’ to the resonant frequency of
the thruster, there is next to zero chance that the VCO, and by extension the
drive power to the thruster, stayed within the bandwidth of the thruster
during the test run OR that, for the high Q thruster, a large percentage of
the source power was within the thruster bandwidth, even if the center
frequency of the source remained centered on the resonant frequency of the
thruster.  VCO’s are VERY spectrally dirty and, unless phase locked, very
unstable in relation to the spectral purity required by Brady’s thruster.   


NOTE by J.RODAL: Brady's report states:

<<During testing, the Test Engineer controls the RF frequency generation via a 0-to-28 volts dc power input to a voltage-controlled oscillator (VCO). The VCO RF signal output is passed to a variable voltage attenuator (VVA), the output of which is controlled by the Test Engineer via a 0-to-17 volts dc power input. Based upon the VVA output, the amplifier will output up to approximately 28 watts. Amplifier output passes to a dual-directional coupler (DDC), which allows forward and reflected power measurements to be obtained as the power is simultaneously passed to the test article input port. The Test Engineer monitors forward and reflected power and adjusts the input frequency to obtain the desired combination of cavity frequency and power delivery to the cavity.>> p.8

<<The 25 watt amplifier was driven by a Mini-Circuits® voltage controlled oscillator (VCO) passed through a Mini-Circuits® variable voltage attenuator (VVA). The output of the RF amplifier was run through a dual directional coupler (DDC) with power meters positioned to measure forward and reflected power from the test article. For final tuning prior to testing on the rig, typically a stub tuner was placed between the DDC and the test article and the VNA’s Smith Chart and S11 plots were used to optimize coupling with the test article. Figure 17 shows the thruster mounted on the torsion pendulum arm and how it was connected to the RF amplifier.>> p.13

This is the website for the Mini-Circuits® voltage controlled oscillator (VCO)
Mini-Circuits® has over 800 low-noise & wideband models from 3 MHz to 7 GHz:
http://www.minicircuits.com/products/Oscillators.shtml


At any rate, based on the measured frequency and Q of the thruster, the
‘anomaly’ is easily explained (actually, expected) if the drive source
frequency stability and spectral purity were not suited to the requirements of
the thruster.  Since test frequencies were only specified to +/- 1 MHz, while
the bandwidth of the thruster required that the source be tunable and stable
in the tens of KHz range, or ideally, less, I suspect that that was the case.


If on the other hand Brady was using a state of the art synthesized signal
source and a ‘clean’ amplifier and ensured that the source was tuned to the
center of the thruster bandwidth during the entire test, never mind.


(All of which calls attention to potential problems with Shawyer’s G2
superconducting thruster.  Postulating (and hoping fervently) that the
technology actually works, a superconductor thruster with a Q of 1e9, and a
design frequency of 2 GHz, that implies that the drive source has to be
accurate and stable to within +/- 1 Hz.  In other words, that essentially ALL
of the drive power be contained within a bandwidth of +/- 1 Hz, centered on
the resonant frequency of the thruster.  That is easily achievable, as very
clean synthesized sources with tuning steps of +/- 0.001 Hz are available in
that frequency range, but magnetrons need not apply unless they are phase
locked to a very stable source.  This is possible, but I couldn’t find out
much about their spectral purity within 1 Hz of their nominal output
frequency.  Another problem he may have is mechanical stability of the
thruster.  It is hard for me to imagine a superconducting thruster whose
resonant frequency (set by physical dimensions) remains stable within +/- 1e9
while undergoing mechanical stresses varying between zero and many tons.  But
I suppose that that is JUST engineering. )


Bob Ludwick
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/15/2014 12:57 am
From this it is clear that L is the Unruh wave length and that the cavity walls are assumed to act like a Hubble horizon.

Fixed that for ya.  This is an assumption or a speculation, not a proven fact.

Correct me if I'm wrong.
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 01:25 am
From this it is clear that L is the Unruh wave length and that the cavity walls are assumed to act like a Hubble horizon.

Fixed that for ya.  This is an assumption or a speculation, not a proven fact.

Correct me if I'm wrong.

These are the critical assumptions:

1) the microwaves-photons bouncing around within the EM Drive cavity have inertia (due to their momentum), which is determined by McCulloch's quantised inertia.

2) the microwaves-photons within the EM Drive cavity undergo momentum change ("acceleration") large enough to produce McCulloch inertial changes due to Unruh radiation .  The momentum change ("acceleration") must be greater than 8 c^2 / (DiameterOfBaseOfCone).

3) In McCulloch's quantised inertia the Unruh waves are allowed only if they fit exactly within the Hubble horizon (or within a local Rindler horizon).  For the formula to apply the EM Drive cavity walls must act like a horizon.



Photons exhibit inertia by resisting a change in momentum. (Conservation of momentum is one of the most fundamental laws of Physics, in General Relativity, Quantum Mechanics and in Continuum Mechanics).  As Aerospace Scientists and Aerospace Engineers know, conservation of momentum is more general than Newton's 2nd Law for rigid bodies (for example as in the rocket equation, where the mass of the rocket changes as it ejects propellant).

The momentum of a photon is given by p = h k = (h  /(2*Pi) )* k, where k is the wave vector, which has magnitude 2*Pi*frequency/c and points in the same direction as the propagation direction of the photon.  Therefore the magnitude of the photon's momentum is  h*frequency/c  .

The momentum of a photon can change in two possible ways:

A) its direction can change. For example as in gravitational lensing, where the path of a photon changes due to gravitation.

B) its frequency can change. For example as in gravitational redshift.  As it moves away from a much more massive body it loses energy and momentum.  As it loses momentum, it becomes redshifted.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/15/2014 05:09 am
Ok...if I am understanding the more recent posts correctly, then the thrust produced by this device is very frequency dependent?

Quote
1) the microwaves-photons bouncing around within the EM Drive cavity have inertia (due to their momentum), which is determined by McCulloch's quantised inertia.

2) the microwaves-photons within the EM Drive cavity undergo momentum change ("acceleration") large enough to produce McCulloch inertial changes due to Unruh radiation .  The momentum change ("acceleration") must be greater than 8 c^2 / (DiameterOfBaseOfCone).

3) In McCulloch's quantized inertia the Unruh waves are allowed only if they fit exactly within the Hubble horizon (or within a local Rindler horizon).  For the formula to apply the EM Drive cavity walls must act like a horizon.


So the idea would be to make certain points 2 and 3 above are 'in sync?'  Which, if I follow the previous posts right, means the size of this device and angle of the cone are also crucial?

Or, in other words, 'tuning' this thing to work correctly - or at all - is as important as the mechanism design itself.  I wonder if this could account for some of the past experimental flops? 
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 12:01 pm
Whether the experimental response is an experimental artifact or whether it is thrust that may or may not be useful eventually for space propulsion, it is a fact that it is very dependent on tuning the device to reach maximum amplitude resonance.  As the amplitude of resonance is in general a very nonlinear response of frequency, and as in this case the researchers are purposely seeking high Q (low damping), the bandwidth of the response is very small and hence it is difficult to produce a consistent response.  This has been brought up by Ludwick in his excellent post above.  The uncertainty in the results has to do with resonance, high Q (low damping), small bandwidth, knowing at what precise frequency the maximum amplitude of resonance takes place and keeping the frequency at that critical frequency. 

for high Q,  Q ~ (ResonantFrequency) / (half-power bandwidth); so

(half-power bandwidth) ~ (ResonantFrequency) / Q
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/15/2014 01:14 pm
This is understood by any structural engineer using beam equations instead of fully 3-D equations that are unsolvable without numerical analysis.

I'm partly new, but mostly older, ergo am rusty with structural engineering.  But structural engineering is actually doable at my level; here's a simple beam program I wrote nearly twenty years ago.

Point being, I fully appreciate the value of the 1D analysis, as it would have pragmatic value in the schematic design of starships, just as the simple equztions of beam stiffness, yada yada are completely sufficient for structural engineering.

Quote from: Bones
The usefulness of closed-form solutions ... is certainly understood by Aerospace Engineers.

It was never a question of whether or not AE's could "understand" these complex equations.  I continue to point out that the Unruh Effect is hypothetical.  If it is real, then it appears to predict some of the "anomalous thrusts", but by no means all of them.  If the Hubble constant is not known, and the theory depends on this knowledge to derive the Unruh wavelenth and the sweet frequency spot,  it causes me emotional struggle:

Quote from: Aero
And just in case you are unaware of it, the best estimate of the value of the Hubble constant has changed several times during the past 10 years. Current best estimate seems to be 2.19725E-18/s with uncertainty of about 5%.

It seems to be the bane of the theorist, shifting constants. (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html)

As an aside, I'm guessing that it isn't a "constant", it is a "habit".

Just for fun, let's say the prediction curve is absolutely accurate and based on 70 years of experience w/ copper waveguides and resonators.  Then the difference w/ these tapered chambers represent a loss of power which is going somewhere ???

The copper waveguide is full of compressed hummingbird wings (CHBW), which are absorbing the heat.  There is no evidence presented regarding the interior of the copper device.  If not full of CHBW, it is full of air.  Which should get warm, if the 34% chart is accurate.  Right?

The uncertainty experimental bars are very large and they overwhelm the very small frequency range that was explored.

A guitar is either in tune, or it is not.  I wonder if the theorists here believe that there is a special sauce quality about the frequency ranges investigated?

Quote from: Aero
What can we say about the nature of the acceleration coupling to the Unruh wave? (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html)

Well, yeah.

I gotta run to the store and get some more peanuts.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/15/2014 01:20 pm
In McCulloch's quantised inertia the Unruh waves are allowed only if they fit exactly within the Hubble horizon (or within a local Rindler horizon).  For the formula to apply the EM Drive cavity walls must act like a horizon.

So, you have to assume that the copper walls "must" act like a horizon.  Which suggests an experiment to determine if they do or not, before erecting the thoretical house of cards too high.
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 02:32 pm
In McCulloch's quantised inertia the Unruh waves are allowed only if they fit exactly within the Hubble horizon (or within a local Rindler horizon).  For the formula to apply the EM Drive cavity walls must act like a horizon.

So, you have to assume that the copper walls "must" act like a horizon.  Which suggests an experiment to determine if they do or not, before erecting the thoretical house of cards too high.
Overdue emphasis on physical explanations rather than mathematical examination of the data is misplaced, particularly with anomalous results of early  experimental results with high uncertainty bars. 

An objective, cool, mathematical viewpoint (rather than passionate subjective beliefs) is called for.

A great example of this is Maxwell's book on Electromagnetism.  Maxwell's equations are still correct.  However, the physical reasons for electromagnetic waves are different.  A reading of Maxwell's book is very revealing on the need for a mathematical language rather than words.  Another example is the arguments concerning corpuscular vs. the wave explanations for light (it turns out that light is both: both a particle and a wave).

This is why mathematics, rather than words, is the language of Physics. 

At this point, the emphasis should be on the mathematical formula presented by McCulloch.  McCulloch's simple formula, without any fudge factors, and with a minimum of parameters, does a much better job at predicting the experimental results than anything else presented so far:   

Force = ( PowerInput  * Q / frequency ) * (1/DiameterSmallBase - 1/DiameterBigBase)

Ink spent arguing about unwarranted extrapolations to pointy cones, unexamined geometries, unexamined frequencies, unexamined Q, unexamined power inputs, are the responsibility of those who engage on those extrapolations. 

It just amounts to argumentative noise based on randomness emanating from extrapolations.

Arguments based on such random extrapolations are futile and sterile.
Title: Re: EM Drive Developments
Post by: zen-in on 10/15/2014 04:19 pm
Whether the experimental response is an experimental artifact or whether it is thrust that may or may not be useful eventually for space propulsion, it is a fact that it is very dependent on tuning the device to reach maximum amplitude resonance.  As the amplitude of resonance is in general a very nonlinear response of frequency, and as in this case the researchers are purposely seeking high Q (low damping), the bandwidth of the response is very small and hence it is difficult to produce a consistent response.  This has been brought up by Ludwick in his excellent post above.  The uncertainty in the results has to do with resonance, high Q (low damping), small bandwidth, knowing at what precise frequency the maximum amplitude of resonance takes place and keeping the frequency at that critical frequency. 

for high Q,  Q ~ (ResonantFrequency) / (half-power bandwidth); so

(half-power bandwidth) ~ (ResonantFrequency) / Q
The resonant frequency of the device in the paper by Brady, White, et al would to be determined by two things:  The diameter of the loop antenna inside the device and to a lessor extent the dielectric material near it.   Earlier I stated there had to be some kind of ceramic resonator inside.   But I know think there isn't one and the concensus is that the dielectric is a large disk of polystyrene in the small end.  A small loop will have a natural frequency based on its inductance and parasitic capactance.   The Q of a loop antenna inside a shielded and grounded enclosure will be quite high.   I think the different experimental runs shown in table E of the paper were done after changing that loop.   The resonant frequency and Q were then determined with the network analyzer.   Bob Ludwick stated it is very difficult to get a VCO precisely on frequency when the Q is high.   A better method is to use the high Q cavity itself as the frequency determining element and to build a free-running high power RF oscillator around it.  It will automatically lock to the resonant frequency and track any changes due to temperature.   Low phase noise RF generators use tuneable cavities driven at low power.   Whether that will produce a propellantless propulsion device is still TBD.  I still think there are undiscovered thermal or magnetic errors in these experiments.
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 04:36 pm
Earlier I stated there had to be some kind of ceramic resonator inside.   But I know think there isn't one and the concensus is that the dielectric is a large disk of polystyrene in the small end.

Not polysterene   (PS).  The dielectric was Polyethylene (PE), as first found by @notsosureofit.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/15/2014 04:40 pm
@Rodal : science is not only reason but also passion. Hopefully this is a passion for truth and at the end, reason wins. Nevertheless a minimum of stamina, intuition and some amount of randomness and chaos plays its role in discoveries, as AI as shown. So futile maybe, not always sterile, just often. And unless explicitly stated otherwise by admins, can't we have a bit of fun with the words and ideas ? Obviously we are all significant parts of reality, we have some right to have a passionate experimental opinion about what is reality and how it works. I was considering building a random formula generator for seeing best empirical fit, but alas the data are really sparse.

Still struggling to see how the momentum conservation would propagate to rest of cosmos in some "photon Unruh" generated perturbation, like pushing on the walls of its own universe or pushing on one's own acceleration. Surely this costs some energy, how can this energy be less than   c*acquired_momentum   or else borrowed from some potential, that is, communicated to the outside ? Also I fail to see how the "Unruh effect zone" could act differently when something is entering than leaving, I guess it is a dynamic "potential" but in this case it costs energy to maintain (there is more energy put in a pool wave generator than a surfer can recover). Anyway I enjoy reading both the serious attempts at synthesis and futile extrapolations. Hope we are not thrown from the bar by the keeper for all this noise (jetés du bar par le tenancier à cause de tout ce bruit)

All my best
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/15/2014 04:42 pm
Whether the experimental response is an experimental artifact or whether it is thrust that may or may not be useful eventually for space propulsion, it is a fact that it is very dependent on tuning the device to reach maximum amplitude resonance.  As the amplitude of resonance is in general a very nonlinear response of frequency, and as in this case the researchers are purposely seeking high Q (low damping), the bandwidth of the response is very small and hence it is difficult to produce a consistent response.  This has been brought up by Ludwick in his excellent post above.  The uncertainty in the results has to do with resonance, high Q (low damping), small bandwidth, knowing at what precise frequency the maximum amplitude of resonance takes place and keeping the frequency at that critical frequency. 

for high Q,  Q ~ (ResonantFrequency) / (half-power bandwidth); so

(half-power bandwidth) ~ (ResonantFrequency) / Q
The resonant frequency of the device in the paper by Brady, White, et al would to be determined by two things:  The diameter of the loop antenna inside the device and to a lessor extent the dielectric material near it.   Earlier I stated there had to be some kind of ceramic resonator inside.   But I know think there isn't one and the concensus is that the dielectric is a large disk of polystyrene in the small end.  A small loop will have a natural frequency based on its inductance and parasitic capactance.   The Q of a loop antenna inside a shielded and grounded enclosure will be quite high.   I think the different experimental runs shown in table E of the paper were done after changing that loop.   The resonant frequency and Q were then determined with the network analyzer.   Bob Ludwick stated it is very difficult to get a VCO precisely on frequency when the Q is high.   A better method is to use the high Q cavity itself as the frequency determining element and to build a free-running high power RF oscillator around it.  It will automatically lock to the resonant frequency and track any changes due to temperature.   Low phase noise RF generators use tuneable cavities driven at low power.   Whether that will produce a propellantless propulsion device is still TBD.  I still think there are undiscovered thermal or magnetic errors in these experiments.

Used to do this w/ re-entrant cavities where it worked well.  Not sure about which mode it might lock to in a tapered cavity, but I'm sure that could be worked out.
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 04:51 pm
science is not only reason but also passion. ...

All my best

Rule Britannia. Better to keep a stiff upper lip.   :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 05:07 pm
We continue our statistical exploration of the experimental data. We now examine the experimental and predicted Power Input, for the EMDrive experiments conducted in the US, UK and China, and reported in my my last post with data (please refer to:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1270264#msg1270264  ).

The horizontal axis shows the experimentally measured Power Input.

The vertical axis shows the predicted Power Input from McCulloch's formula (inverted to express the Power Input as a function of the other variables: the measured force, the measured Q, the measured frequency, and the measured diameter of the small and big bases of the truncated cone),  expressed as follows:

PredictedPowerInput = (ExperimentalForce)*Frequency/(Q*(1/Dsmall-1/Dbig))

It is obvious from the plot that:

1) There is a significant experimental dependence on Power Input, the R^2 value is statistically significant: 81% (and this is including the outlier data: the very anomalous test reported by Brady et.al at a frequency of 1.937 GHz).  The coefficient of determination (R^2) for the Power Input is identical to the coefficient of determination for Q.

2) The actual Power Input dependence is linear as predicted by McCulloch's formula, as shown by the least squares formula shown in the box.  It is certainly linear within the (obvious from plotting the data) experimental uncertainty in the measurements.

3) The fact that the predicted curve (in red) is off by a factor of ~21%, as I have previously addressed in Prof. McCulloch's blog is expected, since McCulloch's formula is a 1 Dimensional simplification of the full 3-D Modified Inertia formulation: as the simplified formula neglects the Unruh wave contribution from the curved sides of the cone (the simplified formula only uses the flat areas into consideration).

4) It is obvious from the plot that the power input used by NASA Eagleworks is completely insignificant, lower by orders of magnitude than the power inputs used by Shawyer in the UK and by Prof. Juan Yang in China.
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 05:39 pm
We finalize our statistical exploration of the experimental data. We now examine the experimental and predicted Geometrical Information, for the EMDrive experiments conducted in the US, UK and China, and reported in my my last post with data (please refer to:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1270264#msg1270264  ).

The horizontal axis shows the experimentally measured quantity: (1/DiameterOfSmallBase-1/DiameterOfBigBase).

The vertical axis shows the predicted (1/DiameterOfSmallBase-1/DiameterOfBigBase) from McCulloch's formula (inverted to express (1/DiameterOfSmallBase-1/DiameterOfBigBase) as a function of the other variables: the measured force, the measured Q, the measured frequency, and the measured power input),  expressed as follows:

Predicted(1/DiameterOfSmallBase-1/DiameterOfBigBase)  = (ExperimentalForce)*Frequency/(Q*PowerInput)

It is obvious from the plot that:

1) There is a significant experimental dependence on (1/DiameterOfSmallBase-1/DiameterOfBigBase) , the R^2 value is very statistically significant: 90% (and this is including the outlier data: the very anomalous test reported by Brady et.al at a frequency of 1.937 GHz).  It is a surprising find (at least to me) that the most statistically significant coefficient of determination (R^2) is this geometrical information.  It is even more significant than the Power Input and the Q.  This represents a big challenge for those attempting to explain the experimental data as an experimental artifact, either due to magnetic, thermal or any other reason not evidently related to the dimensions of the bases of the truncated cone.

2) The dependence on (1/DiameterOfSmallBase-1/DiameterOfBigBase) is linear as predicted by McCulloch's formula, as shown by the least squares formula shown in the box.  It is certainly linear within the (obvious from plotting the data) experimental uncertainty in the measurements.

3) The fact that the predicted curve (in red) is off by a factor of ~30%, as I have previously addressed in Prof. McCulloch's blog is expected, since McCulloch's formula is a 1 Dimensional simplification of the full 3-D Modified Inertia formulation: as the simplified formula neglects the Unruh wave contribution from the curved sides of the cone (the simplified formula only uses the flat areas into consideration).

4) It is apparent from this data that Shawyer in the UK and Prof. Juan Yang in China had a better handle on the importance of (1/DiameterOfSmallBase-1/DiameterOfBigBase) as compared to NASA Eagleworks. NASA Eagleworks tested drives that had the least amount of (1/DiameterOfSmallBase-1/DiameterOfBigBase).  The Cannae device is practically symmetric and the truncated cone tested by NASA Eagleworks has a significantly smaller difference between the inverse of the base diameters (1/DiameterOfSmallBase-1/DiameterOfBigBase) than Shawyer's and China's drives.  This unnecessarily limited the thrust output of the NASA Eagleworks measurements.  NASA Eagleworks should learn from Shawyer and China regarding the importance of this geometrical parameter
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 06:52 pm
We summarize our statistical exploration of the experimental data. We have examined the experimental and predicted Power Input, Q, Frequency and Geometrical Information, for the EMDrive experiments conducted in the US, UK and China, and reported in my my last post with data (please refer to:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1270264#msg1270264  ).

The horizontal axis shows the experimentally measured quantity.

The vertical axis shows the prediction from McCulloch's formula (inverted to express the predicted variable as a function of the other variables: the measured force, and the remaining variables).  For example, when presenting the difference between the inverted diameters of the bases of the truncated cone, the expression is as follows:

Predicted(1/DiameterOfSmallBase-1/DiameterOfBigBase)  = (ExperimentalForce)*Frequency/(Q*PowerInput)

McCulloch's simple formula, without any fudge factors, and with a minimum of parameters, does a much better job at predicting the experimental results than anything else presented so far:   

Force = ( PowerInput  * Q / frequency ) * (1/DiameterSmallBase - 1/DiameterBigBase)


STATISTICAL ANALYSIS OF EMDrive EXPERIMENTAL DATA

1) The results of this statistical data exploration should be (perhaps) very surprising to those, like me, that started their analysis of the EM Drives experimental data thinking that they must be an experimental artifact. 

2) There is a significant experimental dependence on the following variables, presented here in the following descending order of coefficient of determination (R^2) :

(1/DiameterOfSmallBase-1/DiameterOfBigBase) with R^2 = 90%

Q (resonance quality factor) with R^2 = 81%

Power input with R^2 = 81%


The variable with the highest coefficient of determination (R^2) is the difference of inverse diameters for the bases of the truncated cone, followed by Q and the power input.

NASA Eagleworks tested drives had the least amount of (1/DiameterOfSmallBase-1/DiameterOfBigBase).  The Cannae device is practically symmetric and the truncated cone tested by NASA Eagleworks has a significantly smaller difference between the inverse of the base diameters (1/DiameterOfSmallBase-1/DiameterOfBigBase) than Shawyer's and China's drives.  This unnecessarily limited the thrust output of the NASA Eagleworks measurements.  NASA Eagleworks should learn from Shawyer and China regarding the importance of this geometrical parameter

3) Including all the data (including an obvious outlier) shows practically no statistical dependence on frequency.  The coefficient of determination (R^2) for frequency a very poor R^2 = - 12%.  There is a clear statistical outlier (Brady et.al. at 1.937 GHz) that I have repeatedly pointed out.  The fact that this is a statistical outlier is evident from the plot.  Essentially, including the statistical outlier indicates that the uncertainty overwhelms the power to conclude anything concerning frequency dependence. The uncertainty experimental bars are very large and they overwhelm the very small frequency range that was explored.  The experiments in the US, UK and China did not peform a satisfactory exploration of frequencies.  Basically only two frequency ranges have been explored: ~1.9 GHz in the US and ~2.5 GHz in the UK and China.  Considering the data without the outlier gives a still weak statistical dependence: R^2 = 22%.  Essentially inversely proportional to the frequency, as predicted by McCulloch, but again there is not enough statistical data to make any statistical conclusion regarding frequency dependence.

A very important issue is the fact that resonance amplitude is a very nonlinear function of frequency.  Besides this being expected, such resonance amplitude nonlinear dependence on frequency is shown in the S22 plots.  Hence it is not surprising that a formula that is inversely proportional to frequency cannot possibly reflect the huge changes in amplitude resonance emanating from small changes in frequency (for example for Brady et.al. at 1.88, 1.933 and 1.937 GHz), particularly when experimenters deliberately chose to conduct their experiments at frequencies close to resonance.

4) So far, all the experimental data variation in the US (NASA Eagleworks, including the statistical outlier), the UK and China can be explained solely in terms of just three variables:

A) (1/DiameterOfSmallBase-1/DiameterOfBigBase)
B) Q (resonance quality factor)
C) Power Input


5) The uncertainty in the data is due to the very nonlinear relationship between resonance amplitude and frequency, as the researchers seek to test in conditions of highest resonance amplitude with highest Q, with concomitant very narrow power frequency bandwith, which introduces experimental uncertainty particularly when using a voltage-controlled oscillator (VCO).  To quote Ludwick:

"If Brady was using a free running VCO, ’tuned’ to the resonant frequency of the thruster, there is next to zero chance that the VCO, and by extension the drive power to the thruster, stayed within the bandwidth of the thruster during the test run OR that, for the high Q thruster, a large percentage of  the source power was within the thruster bandwidth, even if the center frequency of the source remained centered on the resonant frequency of the thruster.  VCO’s are VERY spectrally dirty and, unless phase locked, very unstable in relation to the spectral purity required by Brady’s thruster."
Title: Re: EM Drive Developments
Post by: aero on 10/15/2014 08:30 pm
I found a relatively new paper (dated 2014) on the Unruh effect that I could almost read mostly because it has more words than equations.

http://www.scholarpedia.org/article/Unruh_effect (http://www.scholarpedia.org/article/Unruh_effect)

Quote
The Unruh effect is a surprising prediction of quantum field theory: From the point of view of an accelerating observer or detector, empty space contains a gas of particles at a temperature proportional to the acceleration. Direct experimental confirmation is difficult because the linear acceleration needed to reach a temperature 1 K is of order 1020 m/s2, but it is believed that an analog under centripetal acceleration is observed in the spin polarization of electrons in circular accelerators. Furthermore, the effect is necessary for consistency of the respective descriptions of observed phenomena, such as particle decay, in inertial and in accelerated reference frames; in this sense the Unruh effect does not require any verification beyond that of relativistic free field theory itself. The Unruh theory has had a major influence on our understanding of the proper relationship between mathematical formalism and (potentially) observable physics in the presence of gravitational fields, especially those near black holes.

The paper goes on to introduce "things" related to the effect which was most interesting.
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 08:41 pm
I found a relatively new paper (dated 2014) on the Unruh effect that I could almost read mostly because it has more words than equations.

http://www.scholarpedia.org/article/Unruh_effect (http://www.scholarpedia.org/article/Unruh_effect)


Yes, I agree, this is an excellent article.   

This excellent article should not be used by those that don't like the Unruh radiation explanation to get side-tracked on a discussion of Unruh radiation and lose track of the fact that the experimental data and its analysis  show very strong dependence on

A) the difference between the inverse of the diameters of the cone bases,
B) the quality factor Q and
C) the power input. 

Instead:

Those thinking that the results are an experimental artifact should seek artifact explanations that are consistent with the experimental data being linearly dependent on just these three variables. 

Those uncomfortable with the Unruh radiation explanation (how photons in a microwave cavity can be subjected to inertial changes and the required black-hole-like-accelerations ?) should seek other physical explanations that are consistent with the experimental data being linearly dependent on just these three variables.


Title: Re: EM Drive Developments
Post by: frobnicat on 10/15/2014 09:24 pm
Those thinking that the results are an experimental artifact should seek artifact explanations that are consistent with the experimental data being linearly dependent on just these three variables. 

Yes dr Rodal, working on that.
Better to keep a stiff upper lip, hey !

7 data points is sparse to conduct statistical analysis but you do a great job. Though I wonder if it wouldn't be more appropriate to conduct the regressions in log log plane, as the low values dispersions tend to be squashed by the low absolute levels, while their relative dispersion around the (linear) predicted values seem more natural to me : log(experimental/predicted) or equivalently log(experimental)-log(predicted)  (then squared as for the least square regression). A linearly scaling formula that predicts 1.0µN for a 1.1µN measure has as much error than predicting 1N instead of actual 1.1N. Maybe this is already the case in your R^2 results ?

Anyway, since you have the tools at hand, can I have a request for log log plots ?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/15/2014 09:46 pm
@dr Rodal, I'm trying to do my homework by having a fancy machine to chew some numbers and symbols, how did you manage the following datapoints ?

- Shawyer (2008) b : 80-214 observed. Is that an apparatus calculated range of error around a single measure or experimental dispersion of many measures ? What do we take, arithmetic mean, geometric mean ?

- Juan (2012) TE011 and TE012 : geometry unknowns, good reasons to believe it's the same as Shawyer ? Considering 9 data points, knowing two are wrong ? Averaging the hypothesis ? (arithmetically or geometrically ?) Discarding those two data points would left us with nothing much...
Title: Re: EM Drive Developments
Post by: aero on 10/15/2014 09:58 pm
Quote
dF = (PQ/c)*((L/w_big)-(L/w_small)) = (PQ/f)*((1/w_big)-(1/w_small)).

Which boils down to dF = (PQ/f)*((1/w_big)-(1/w_small)).

P - Power
Q - Quality factor
f - Drive frequency
w_big - diameter of the big end
W_small - diameter of the small end.

My goodness, where is the Unruh radiation, the Hubble horizon, the Casimir effect or any other strange factors?

The only way MiHsC enters the picture is because it led Prof. M to the above equation.

As it stands the equation can be written as

  dF = [ Stored power/w_big - Stored power/w_small ] / f

where stored power = Q * Power.

Does that mean anything helpful?
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 10:13 pm
Those thinking that the results are an experimental artifact should seek artifact explanations that are consistent with the experimental data being linearly dependent on just these three variables. 

Yes dr Rodal, working on that.
Better to keep a stiff upper lip, hey !

Quote
7 data points is sparse to conduct statistical analysis
I both agree and disagree.  Yes, I would prefer to have thousands of data points instead.  However, given the fact that this is all the data we have, no statistical analysis of the data would be even worse.  Ignoring the data would be worse.  Using lots of words and pre-conceived ideas to explain the data would be much worse.

Quote
but you do a great job.
Thanks.  I wonder what comes next  :)

Quote
Though I wonder if it wouldn't be more appropriate to conduct the regressions in log log plane, as the low values dispersions tend to be squashed by the low absolute levels, while their relative dispersion around the (linear) predicted values seem more natural to me : log(experimental/predicted) or equivalently log(experimental)-log(predicted)  (then squared as for the least square regression). A linearly scaling formula that predicts 1.0µN for a 1.1µN measure has as much error than predicting 1N instead of actual 1.1N. Maybe this is already the case in your R^2 results ?
In general I don't like log-log regressions because just about everything looks great regressed that way.
You do have a point concerning data squashing however log-log plotting introduces many other problems.

The main problem is the very nonlinear relationship between amplitude and frequency that has introduced tremendous outliers (particularly in the NASA Eagleworks experiments with extremely small power inputs that also produced extremely small force values).   Since the NASA Eagleworks tests were conducted with the smallest Power, the smallest forces, and the smallest differences in diameter, what this does is to exaggerate the outliers.

However reluctantly (I favor the linear plots for the aforementioned reasons) I comply with your request in the interest of objectivity and the communal work in this thread  :)


Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 10:19 pm
Quote
dF = (PQ/c)*((L/w_big)-(L/w_small)) = (PQ/f)*((1/w_big)-(1/w_small)).

Which boils down to dF = (PQ/f)*((1/w_big)-(1/w_small)).

P - Power
Q - Quality factor
f - Drive frequency
w_big - diameter of the big end
W_small - diameter of the small end.

My goodness, where is the Unruh radiation, the Hubble horizon, the Casimir effect or any other strange factors?

The only way MiHsC enters the picture is because it led Prof. M to the above equation.

As it stands the equation can be written as

  dF = [ Stored power/w_big - Stored power/w_small ] / f

where stored power = Q * Power.

Does that mean anything helpful?

It is an argument against thermal explanations (stored power instead of loss power)

Anybody seeking explanations on magnetic, artifact or any other explanations should explain the geometrical factor (that came from McCulloch's theory) .
Title: Re: EM Drive Developments
Post by: aero on 10/15/2014 10:39 pm
Quote
It is an argument against thermal explanations (stored power instead of loss power)

Perhaps, but it is exactly the same equation as always, just arranged differently.

Quote
The geometrical factor (that came from McCulloch's theory) needs to be explained by magnetic, artifact or any other explanation

I agree. The terms 1/dia are strange. 1 / big and 1 / small aren't strange at all but why a length? Is that commonly used in radiation calculations / reflections?
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 10:47 pm
Quote
It is an argument against thermal explanations (stored power instead of loss power)

Perhaps, but it is exactly the same equation as always, just arranged differently.

It is an argument against thermal explanations, because the higher the Q, the less power that it is dissipated (into heat to the walls and elsewhere). 

I don't understand <<it is exactly the same equation as always>>.  The same equation as what precisely?

Thanks
Title: Re: EM Drive Developments
Post by: aero on 10/15/2014 10:53 pm
Quote
dF = (PQ/c)*((L/w_big)-(L/w_small)) = (PQ/f)*((1/w_big)-(1/w_small)).

Which boils down to dF = (PQ/f)*((1/w_big)-(1/w_small)).

P - Power
Q - Quality factor
f - Drive frequency
w_big - diameter of the big end
W_small - diameter of the small end.

My goodness, where is the Unruh radiation, the Hubble horizon, the Casimir effect or any other strange factors?

The only way MiHsC enters the picture is because it led Prof. M to the above equation.

As it stands the equation can be written as

  dF = [ Stored power/w_big - Stored power/w_small ] / f

where stored power = Q * Power.

Does that mean anything helpful?

dF = (PQ/f)*((1/w_big)-(1/w_small)) =  [ Stored power/w_big - Stored power/w_small ] / f

where stored power = Q * Power.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/15/2014 10:57 pm
...

Please re-write or withdraw your comment about the Chinese.

Done withdrawal, was silly, but didn't mean anything mean against you or Chinese scientists.

Thank you for the log log plots. Agree that in log log everything looks too good... don't know if it holds for some eminent statistician (which I am not) but I find the log log more convincing as we have very few diversity if the 3 Brady et al entries get squashed. Save the outlier, the other two still look good relative to much lower magnitudes overall.

Still wondering what to do with ranges in the tabulated data...
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 10:59 pm
Quote
dF = (PQ/c)*((L/w_big)-(L/w_small)) = (PQ/f)*((1/w_big)-(1/w_small)).

Which boils down to dF = (PQ/f)*((1/w_big)-(1/w_small)).

P - Power
Q - Quality factor
f - Drive frequency
w_big - diameter of the big end
W_small - diameter of the small end.

My goodness, where is the Unruh radiation, the Hubble horizon, the Casimir effect or any other strange factors?

The only way MiHsC enters the picture is because it led Prof. M to the above equation.

As it stands the equation can be written as

  dF = [ Stored power/w_big - Stored power/w_small ] / f

where stored power = Q * Power.

Does that mean anything helpful?

dF = (PQ/f)*((1/w_big)-(1/w_small)) =  [ Stored power/w_big - Stored power/w_small ] / f

where stored power = Q * Power.

OK, but this is telling a huge amount of information.

Why should the stored power give you the force?

It should not if the force is a thermal artifact.

It should not if the force is an artifact due to losses in the medium.

It does leave the door open for the force being due to being an artifact due to resonance.
Title: Re: EM Drive Developments
Post by: Rodal on 10/15/2014 11:09 pm
...
Thank you for the log log plots. Agree that in log log everything looks too good... don't know if it holds for some eminent statistician (which I am not) but I find the log log more convincing as we have very few diversity if the 3 Brady et al entries get squashed. Save the outlier, the other two still look good relative to much lower magnitudes overall.

Still wondering what to do with ranges in the tabulated data...

OK thanks  :)

Yes, although I still favor the linear plots for the aforementioned reason, I agree 100% that it is a great idea to also have the LogLog plots. The more ways that one can look at the data the better.  Thank you for bringing it up.


I did not use any averages.

I used the data according to my reading of the papers.  My reading of the Chinese papers (there are two of them) is that they used the same geometry as Shawyer's larger device.

Concerning the other ranges I think I used the maximum but I have to re-check, and get back on what was my justification from reading the papers.

Thanks.

===> We still look forward to your producing an artifact or another physical explanation that explains the data analytically <===
Title: Re: EM Drive Developments
Post by: aero on 10/15/2014 11:40 pm
Quote
dF = (PQ/c)*((L/w_big)-(L/w_small)) = (PQ/f)*((1/w_big)-(1/w_small)).

Which boils down to dF = (PQ/f)*((1/w_big)-(1/w_small)).

P - Power
Q - Quality factor
f - Drive frequency
w_big - diameter of the big end
W_small - diameter of the small end.

My goodness, where is the Unruh radiation, the Hubble horizon, the Casimir effect or any other strange factors?

The only way MiHsC enters the picture is because it led Prof. M to the above equation.

As it stands the equation can be written as

  dF = [ Stored power/w_big - Stored power/w_small ] / f

where stored power = Q * Power.

Does that mean anything helpful?

dF = (PQ/f)*((1/w_big)-(1/w_small)) =  [ Stored power/w_big - Stored power/w_small ] / f

where stored power = Q * Power.

OK, but this is telling a huge amount of information.

Why should the stored power give you the force?

It should not if the force is a thermal artifact.

It should not if the force is an artifact due to losses in the medium.

It does leave the door open for the force being due to being an artifact due to resonance.

Also, look at this formulation.

dF = (PQ/c)*((L/w_big)-(L/w_small)) where L was initially named the Unruh wavelength but was then renamed the RF wavelength.

It happens that the RF wavelength is very nearly equal to w_small, the diameter of the small end of the cavity and perhaps the diameter of the dielectric. By my screen measurements, I measure w_small = 6.6 inches with 6.094 =< wavelength <= 6.278 inches for the RF wave.

Would it be to much trouble to run some statistics on different values of L? In particular the 3 dimensions of the cavity, 6.6, 9.0  and 9.9 inches for the Eagleworks tapered cavity. It may be that L is also related to cavity geometry and not drive power. If that is so it would be very good to know in the design of the next thruster.
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 12:00 am
Quote
OK, let's try to narrow this down.

dF = (PQ/c)*((L/w_big)-(L/w_small))

L= 6.6, 9.0  and 9.9 inches
w_small = 6.6 inches
what do you want for w_big ?

Use the same w_small and w_big that you have been using. My measurement of w_big =9.9 inches. Those two values, w_big and w_small come directly from Prof.  M's formula, don't change them. The length that is uncertain in my mind is L.
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 12:31 am
Quote
OK, let's try to narrow this down.

dF = (PQ/c)*((L/w_big)-(L/w_small))

L= 6.6, 9.0  and 9.9 inches
w_small = 6.6 inches
what do you want for w_big ?

Use the same w_small and w_big that you have been using. My measurement of w_big =9.9 inches. Those two values, w_big and w_small come directly from Prof.  M's formula, don't change them. The length that is uncertain in my mind is L.
OK, I'm using metric units.

So I will use
L=0.16764, 0.2286, 0.25146 m with the same numbers previously used for w_big and w_small

QUESTION: Do you want me to use this L's only for NASA Eagleworks or also for Shawyer and China?
Or do you want to think what values you want for them UK and China?

[Please assume that the Chinese used the same dimensions as the larger Shawyer device, which makes sense from their text and also because Chinese used 1 KW]

These L's are the dimensions of the NASA Eagleworks device. I don't know the dimensions of the Shawyer device. If you do, then use them consistently. That is, small diameter, Cavity length and Large diameter.
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 12:39 am
Quote
OK, let's try to narrow this down.

dF = (PQ/c)*((L/w_big)-(L/w_small))

L= 6.6, 9.0  and 9.9 inches
w_small = 6.6 inches
what do you want for w_big ?

Use the same w_small and w_big that you have been using. My measurement of w_big =9.9 inches. Those two values, w_big and w_small come directly from Prof.  M's formula, don't change them. The length that is uncertain in my mind is L.
OK, I'm using metric units.

So I will use
L=0.16764, 0.2286, 0.25146 m with the same numbers previously used for w_big and w_small

QUESTION: Do you want me to use this L's only for NASA Eagleworks or also for Shawyer and China?
Or do you want to think what values you want for them UK and China?

[Please assume that the Chinese used the same dimensions as the larger Shawyer device, which makes sense from their text and also because Chinese used 1 KW]

These L's are the dimensions of the NASA Eagleworks device. I don't know the dimensions of the Shawyer device. If you do, then use them consistently. That is, small diameter, Cavity length and Large diameter.

We might as well do the best job we can at the outset rather than re-visit later on.

Here is a link to Shawyer's paper:  http://www.emdrive.com/IAC-08-C4-4-7.pdf

please let me know what L dimensions you want to use for the smaller and the larger Shawyer devices

Thanks
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 01:41 am
...
Thank you for the log log plots. Agree that in log log everything looks too good... don't know if it holds for some eminent statistician (which I am not) but I find the log log more convincing as we have very few diversity if the 3 Brady et al entries get squashed. Save the outlier, the other two still look good relative to much lower magnitudes overall.

Still wondering what to do with ranges in the tabulated data...

This paper by Shawyer has 19 test runs:  http://www.emdrive.com/flightprogramme.html
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 02:18 am
Though I wonder if it wouldn't be more appropriate to conduct the regressions in log log plane, as the low values dispersions tend to be squashed by the low absolute levels, while their relative dispersion around the (linear) predicted values seem more natural to me : log(experimental/predicted) or equivalently log(experimental)-log(predicted)  (then squared as for the least square regression). A linearly scaling formula that predicts 1.0µN for a 1.1µN measure has as much error than predicting 1N instead of actual 1.1N. Maybe this is already the case in your R^2 results ?
Here are Log Log plots with the Brady 1937 GHz outlier removed.  It improves the R^2, foremost for the Q regression.  Still the same conclusion regarding the frequency data having a low R^2, even with the outlier removed.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/16/2014 02:19 am
In McCulloch's quantised inertia the Unruh waves are allowed only if they fit exactly within the Hubble horizon (or within a local Rindler horizon).  For the formula to apply the EM Drive cavity walls must act like a horizon.

For a theory to work, reality "must" be a certain way.  Uhhh... that would be a no.

Overdue emphasis on physical explanations rather than mathematical examination of the data is misplaced, particularly with anomalous results of early  experimental results with high uncertainty bars.

An objective, cool, mathematical viewpoint (rather than passionate subjective beliefs) is called for.

I get the principle...

Quote
McCulloch's simple formula, without any fudge factors, and with a minimum of parameters, does a much better job at predicting the experimental results than anything else presented so far...

But you're trying to fit an equation to a data set, while depending on hypothetical waves and a "skin effect" that is not supported by theory or experiment.

Me no get it, kemosabe.  Me primitive man.  Me hung out with mixologist earlier.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/16/2014 02:48 am
Seeking clarity here.


Quote
4) So far, all the experimental data variation in the US (NASA Eagleworks, including the statistical outlier), the UK and China can be explained solely in terms of just three variables:

A) (1/DiameterOfSmallBase-1/DiameterOfBigBase)
B) Q (resonance quality factor)
C) Power Input

So...if I am following this correctly, the logical thing for the research teams to do would be to run thousands (?) of tests in which these three points differ somewhat, ideally in a vacuum.  Aka...different 'truncated cone sizes', different frequencies (?), degrees of power input, that sort of thing, right?  And then a much clearer picture as to what is going on should emerge.  Is that a fair assessment?






Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 02:57 am
Quote
OK, let's try to narrow this down.

dF = (PQ/c)*((L/w_big)-(L/w_small))

L= 6.6, 9.0  and 9.9 inches
w_small = 6.6 inches
what do you want for w_big ?

Use the same w_small and w_big that you have been using. My measurement of w_big =9.9 inches. Those two values, w_big and w_small come directly from Prof.  M's formula, don't change them. The length that is uncertain in my mind is L.
OK, I'm using metric units.

So I will use
L=0.16764, 0.2286, 0.25146 m with the same numbers previously used for w_big and w_small

QUESTION: Do you want me to use this L's only for NASA Eagleworks or also for Shawyer and China?
Or do you want to think what values you want for them UK and China?

[Please assume that the Chinese used the same dimensions as the larger Shawyer device, which makes sense from their text and also because Chinese used 1 KW]

These L's are the dimensions of the NASA Eagleworks device. I don't know the dimensions of the Shawyer device. If you do, then use them consistently. That is, small diameter, Cavity length and Large diameter.

We might as well do the best job we can at the outset rather than re-visit later on.

Here is a link to Shawyer's paper:  http://www.emdrive.com/IAC-08-C4-4-7.pdf

please let me know what L dimensions you want to use for the smaller and the larger Shawyer devices

Thanks

I get.

 Shawyer   Experimental   Demonstrator
Dimension -   meters   meters
w_big, in.    0.1600     0.2800
w_small, in    0.1050     0.0778
height, in    0.1700     0.3811
w_small, external view.       0.1711

The Demonstrator has a constant external small end diameter for about half the length. I speculate that the taper continues internally with the constant diameter section there for whatever reason. That constant diameter section is about 0.1711 meter. Did the Chinese do both sizes?

Edit: I don't think you should use demonstrator numbers. W_big is OK, it's from the text but w_small is probably to small and height to large. I expect the taper stops in the cylindrical section at a height of about 300 mm based on the Experimental and Eagleworks device ratios.. Point is, I can't tell the dimensions of the demonstration device cavity because of the construction. Garbage in, garbage out so just don't use the above Demonstrator numbers I guess.
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 03:10 am
Seeking clarity here.


Quote
4) So far, all the experimental data variation in the US (NASA Eagleworks, including the statistical outlier), the UK and China can be explained solely in terms of just three variables:

A) (1/DiameterOfSmallBase-1/DiameterOfBigBase)
B) Q (resonance quality factor)
C) Power Input
So...if I am following this correctly, the logical thing for the research teams to do would be to run thousands (?) of tests in which these three points differ somewhat, ideally in a vacuum.  Aka...different 'truncated cone sizes', different frequencies (?), degrees of power input, that sort of thing, right?  And then a much clearer picture as to what is going on should emerge.  Is that a fair assessment?
No, it looks like I didn't get my point across well at all.  On the contrary, data is very well explained in terms of those three variables in McCulloch's equation. No need to run thousands of data points. 

Main  experimental need is to be able to tune precisely to the (initially unknown) frequency that gives highest amplitude.  And then for the device to stay tuned to that frequency and not deviate from it while very high resonance with very low damping is achieved.  This was very difficult for researchers to accomplish on a reliable basis.  Once that is accomplished the need is then for NASA to make EM Drive that runs at 1000 watts (like in the UK and China) instead of 20 watts to produce much larger forces.

Secondary need is to explain precisely what is the physical effect that is producing the thrust measurements. 
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 03:28 am
While stumbling through Shawyer's papers, I reached the conclusion that his thrust equation, after substituting the parameter names that Prof. M used, is:

T = 2*So * P*Q/c *(RF wavelength/w_big - RF wavelength/w_small) or

T = 2*So  *P*Q/f  *(1/w_big  - 1/w_small)

where So = (1 - (RF wavelength^2)/(w_big*w_small))^-1

In other words, Shawyer's thrust model differs from Prof. M's thrust model by a multiplicative factor of 2*So .

That of course assumes that I interpreted Shawyer's definition of terms correctly.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/16/2014 05:07 am
Many thanks for your clarification, Doctor Rodal.

Quote
Main  experimental need is to be able to tune precisely to the (initially unknown) frequency that gives highest amplitude.  And then for the device to stay tuned to that frequency and not deviate from it while very high resonance with very low damping is achieved.  This was very difficult for researchers to accomplish on a reliable basis.  Once that is accomplished the need is then for NASA to make EM Drive that runs at 1000 watts (like in the UK and China) instead of 20 watts to produce much larger forces.

Ah ha...sounds very tricky, especially given the at times erratic results. This is looking like one very sensitive and touchy mechanism.   But the potential payoff...wow!

Quote

Secondary need is to explain precisely what is the physical effect that is producing the thrust measurements. 

If this thread is anything to go by, the theory people will still be arguing this one while the test craft is enroute to the moon or Mars or someplace.
Title: Re: EM Drive Developments
Post by: D_Dom on 10/16/2014 05:23 am
Theoretically not much difference between theory and practice, practically the differences are significant.
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 12:35 pm
While stumbling through Shawyer's papers, I reached the conclusion that his thrust equation, after substituting the parameter names that Prof. M used, is:

T = 2*So * P*Q/c *(RF wavelength/w_big - RF wavelength/w_small) or

T = 2*So  *P*Q/f  *(1/w_big  - 1/w_small)

where So = (1 - (RF wavelength^2)/(w_big*w_small))^-1

In other words, Shawyer's thrust model differs from Prof. M's thrust model by a multiplicative factor of 2*So .

That of course assumes that I interpreted Shawyer's definition of terms correctly.

Shawyer's equation looks, superficially, very similar to McCulloch's equation (upon substituting in McCulloch's equation the frequency in the denominator by  f= c / Lambda0), except for the factor of 2/(1 -( (Lambda0^2)^2)/(Lambda1*Lambda2)). However, in McCulloch's equation, f is the frequency in the waveguide, so for McCulloch's equation, f is not equal to c / Lambda0 because Lambda0 is the wavelength in 3-D free space, not the wavelength inside the microwave guide.

Shawyer defines Lambda0 as the "free-space propagation wavelength" and makes a difference between the wavelength inside the microwave cavity (which he calls Lambdag) and the wavelength propagation in free space Lambda0.

A one-dimensional waveguide restricts the three dimensional "free space" propagation of the electromagnetic wave to a single dimension.  Therefore, the 3-D free-space wavelength is shorter than the wavelength in the microwave guide.

I would expect that, the wavelength in the guide, Lambdag=  Lambda0/cos(phi), where phi is  the angle between the crest lines and the waveguide longitudinal axis.  Since cosine is always less than unity, Lambdag is always greater than Lambda0.  In other words, "RF wavelength" is greater than Lambda0.

An interpretation of Shawyer's Lambda0 as RF wavelength would lead to a factor of 2 / (1 - (RF wavelength^2)/(w_big*w_small)) ~ 6 for NASA's truncated cone, multiplying the present equation, leading to predicted forces that would be 6 times larger than the experimentally measured ones.

Using Lambda0, as intended by Shawyer, would lead to a predicted force closer to the experimentally measured one.  So basically, I don't agree with replacing Lambda0 by RF wavelength without taking into account the fact that RF wavelength must be longer than Lamda0.



Also notice that Shawyer gives an equation for the thrust taking into account the dielectric (see:  http://www.newscientist.com/data/images/ns/av/shawyertheory.pdf  equation 11)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/16/2014 12:49 pm
Quote from: some random guy on an intertube thread...
As a veteran member of the American Statistical Association...

Oh right.  Everybody knows that the chances of a coin landing on its edge are fifty-fifty.  You gotta have better credentials than that!
Title: Re: EM Drive Developments
Post by: aceshigh on 10/16/2014 01:32 pm
Quote from: some random guy on an intertube thread...
As a veteran member of the American Statistical Association...

Oh right.  Everybody knows that the chances of a coin landing on its edge are fifty-fifty.  You gotta have better credentials than that!

I thought those were the chances of a coin landing head or tails?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/16/2014 02:27 pm
does this pertain?

arxiv.org/pdf/1312.3267
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/16/2014 02:36 pm
Quote from: some random guy on an intertube thread...
As a veteran member of the American Statistical Association...

Oh right.  Everybody knows that the chances of a coin landing on its edge are fifty-fifty.  You gotta have better credentials than that!

I thought those were the chances of a coin landing head or tails?

See video.  Happens all the time.  Sheesh.

[Edit:  Ooo.  Ooo.  From the snappy comeback department:  That's what fifty-fifty means!  Lands on its edge fifty times out of fifty!]
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 02:39 pm
does this pertain?

arxiv.org/pdf/1312.3267

Pertain ? We're sorry all attendants are still busy Please continue to hold and your call will be answered by the next available attendant Thank you for your patience -

Yes, in the restricted, narrowly specific sense of showing the conservation of momentum and the conservation of energy of photons hitting a perfect mirror and being reflected from the surface (page 2 of that reference).   As previously discussed in another post in this thread, most of the microwave photons get reflected from the copper surfaces.

The reflected photon will be red-shifted for a mirror moving away from the source in the case of a mirror moving at a significant speed with respect to the speed of light in a vacuum.  However, in our case this effect is zero, therefore the reflected photon has exactly the same frequency (and hence the same energy),  the momentum ( a vector quantity) of the reflected photon has the same magnitude (same frequency) but it is oriented in the opposite direction upon reflection.  Since the magnitude is exactly the same, the change in momentum (of the photons hitting the wall and getting reflected) is purely due to change in direction and not due to frequency shifting.

No regarding the negative index materials  because they are artificial man-made structures where the refractive index has a negative value over some frequency range and no known natural materials exhibits this property, definitely not the copper walls in the microwave cavities of the EM Drives.  In my opinion discussion of "dynamic Casimir effects" (mirror walls moving at speeds near the speed of light) and "metamaterials" (materials with negative index of refraction) with respect to the EM  Drives is a distraction, since none of that can take place in the EM Drives.

Thanks for bringing it to our attention.

Here is the refractive index for copper.  In our case the wavelengths are about ~ 150 000 micrometers long, or about 10^5, which is way to the right in the picture below (way off the horizontal scale), hence the refractive index is positive and very large in magnitude (the very few photons making into the copper will have a phase velocity orders of magnitude lower than the speed of light in vacuum).
(http://refractiveindex.info/legacy/figures/figures_RI/n_METALS_Copper_Palik.png)
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 03:41 pm
...

I get.

 Shawyer   Experimental   Demonstrator
Dimension -   meters   meters
w_big, in.    0.1600     0.2800
w_small, in    0.1050     0.0778
height, in    0.1700     0.3811
w_small, external view.       0.1711

The Demonstrator has a constant external small end diameter for about half the length. I speculate that the taper continues internally with the constant diameter section there for whatever reason. That constant diameter section is about 0.1711 meter. Did the Chinese do both sizes?

Edit: I don't think you should use demonstrator numbers. W_big is OK, it's from the text but w_small is probably to small and height to large. I expect the taper stops in the cylindrical section at a height of about 300 mm based on the Experimental and Eagleworks device ratios.. Point is, I can't tell the dimensions of the demonstration device cavity because of the construction. Garbage in, garbage out so just don't use the above Demonstrator numbers I guess.

One could make the same argument regarding NASA Eagleworks internal dimensions (only the internal dimensions matter regarding mode shapes !!) see picture below.  We have discussed this before.  Yes garbage in/garbage out, but experimental information (even when not perfect)  in the eyes of a discerning scientist/engineer is not garbage.  If one throws all information out that is not perfect one ends up with practically nothing to analyze.  What applies here is the following (I first heard this from the Dutch scientist W.Koiter):

"Extreme rigor in analysis leads to rigor mortis"


In this case the scientific/engineering judgement comes in knowing what is the difference in mode shapes between the geometry below and the geometry of a perfect truncated cone.  I made that assessment, so I included the NASA Eagleworks truncated cones and both  Shawyer truncated cones in the data.  What matters mostly are the flat base surfaces of the truncated cone.  This is supported by the data I have previously shown.
Regarding frequency and mode shapes the statistical analysis I have shown demonstrates that there is too much uncertainty anyway to conclude anything.  As brought up by Ludwick this problem is not due to the geometry but it is instead due to the researchers trying but failing to keep the frequency the same when at resonance and high Q due to the extremely narrow bandwith expected at high Q.

(https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcR6hnncVDnqfChw9A-clXqYNz1p7uAIf5AbtqL093pnudg9bT4_)
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 04:12 pm
@Rodal

Quote
An interpretation of Shawyer's Lambda0 as RF wavelength would lead to a factor of 2 / (1 - (RF wavelength^2)/(w_big*w_small)) ~ 6 for NASA's truncated cone, multiplying the present equation, leading to predicted forces that would be 6 times larger than the experimentally measured ones.

Thanks! I ran some numbers and discovered the problem - Now I know what caused it.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/16/2014 04:17 pm
does this pertain?

arxiv.org/pdf/1312.3267

Pertain? We're sorry all attendants are still busy...

Even tho 99% of the time, you want to place an order, please listen carefully to all of our arbitrarily and always recently changed menu options, knowing full well that "place an order" is at the end of the list.  Oh.  And did we say that we're experiencing "unusually heavy phone traffic", like we do all the time, regardless of time of day or season?   And good luck in getting a human being who speaks English sufficiently well to actually take an order...
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 05:11 pm
@Rodal
Quote
In this case the scientific/engineering judgement comes in knowing what is the difference in mode shapes between the geometry below and the geometry of a perfect truncated cone.  I made that assessment, so I included the NASA Eagleworks truncated cones and both  Shawyer truncated cones in the data.  What matters mostly are the flat base surfaces of the truncated cone.  This is supported by the data I have previously shown.

Ok. If I assume the cavity shape of the Demonstrator is the same shape as the Experimental model, then using the published text numbers for the overall diameters, 280 mm and 160 mm, by ratio I calculate the Demonstrator dimensions as:

w_big = 0.28 meters
w_small = 0.18375 meters
height = 0.2975 meters

These are most likely usable numbers but feel free to use the best data you have available.

My problem with this is, "How does he justify larger dimensions on the resonate cavity while using the same or higher frequency drive?"
It must be buried in his theory somewhere.
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 05:52 pm
@Rodal
Quote
In this case the scientific/engineering judgement comes in knowing what is the difference in mode shapes between the geometry below and the geometry of a perfect truncated cone.  I made that assessment, so I included the NASA Eagleworks truncated cones and both  Shawyer truncated cones in the data.  What matters mostly are the flat base surfaces of the truncated cone.  This is supported by the data I have previously shown.

Ok. If I assume the cavity shape of the Demonstrator is the same shape as the Experimental model, then using the published text numbers for the overall diameters, 280 mm and 160 mm, by ratio I calculate the Demonstrator dimensions as:

w_big = 0.28 meters
w_small = 0.18375 meters
height = 0.2975 meters

These are most likely usable numbers but feel free to use the best data you have available.

My problem with this is, "How does he justify larger dimensions on the resonate cavity while using the same or higher frequency drive?"
It must be buried in his theory somewhere.

Excellent question.

I think the answer is simple:  Shawyer may not have the capability to calculate the mode shapes and the amplitude vs. frequency inside the cavity.

Even NASA Eagleworks, using COMSOL Finite Element failed to use a Finite Element mesh discrete enough to closely match the frequency amplitude curve.  Please see attached figure comparing COMSOL FE analysis of NASA Eagleworks compared with actual S22 plot and it is evident that the COMSOL analysis is way off (particularly taking into account the extremely small narrow bandwidths at high Q resonance as pointed out by Ludwick)

There is a huge difference between: A) frequency between NASA's COMSOL analysis and the S22 plot and B) Amplitude between NASA's COMSOL analysis and the S22 plot; particularly at the critical frequencies of 1933 and 1937 GHz that were used by NASA Eagleworks.  It is even a mystery why NASA Eagleworks chose to test at those particular frequencies, as remarked by Ludwick.

And notice that the remark made in the report about removing the dielectric resulted in no thrust refers to a completely different frequency which is off to the right of the right vertical margin of both the COMSOL and the S22 plots.  So why did NASA Eagleworks conduct their dielectric test at a different frequency which is off the plots and different from the other tests?  My reading of this: NASA conducted the dielectric "test" early on (as remarked in the report) at a frequency in which the amplitude is much lower and that's why they measured no thrust: they got no thrust due to the amplitude resonance curve and not due to the dielectric.
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 06:11 pm
Ok.

Now, didn't you show that thrust was not strongly dependent on frequency? But photon momentum is strongly dependent on frequency (as is energy) so does this imply that thrust is not strongly dependent on photon momentum? Or can your approach separate momentum and energy?
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 06:16 pm
Ok.

Now, didn't you show that thrust was not strongly dependent on frequency? But photon momentum is strongly dependent on frequency (as is energy) so does this imply that thrust is not strongly dependent on photon momentum? Or can your approach separate momentum and energy?
No, what I showed was that the variation with frequency overwhelmed the ability to regress the data because of the nonlinearity of the amplitude vs frequency curve and the paucity of frequency data.

On the contrary, the measured thrust is most dependent on amplitude of the resonance curve and the amplitude is very nonlinearly dependent on frequency.
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 06:25 pm
Ok.

Now, didn't you show that thrust was not strongly dependent on frequency? But photon momentum is strongly dependent on frequency (as is energy) so does this imply that thrust is not strongly dependent on photon momentum? Or can your approach separate momentum and energy?
No, what I showed was that the variation with frequency overwhelmed the ability to regress the data because of the nonlinearity of the amplitude vs frequency curve and the paucity of frequency data.

On the contrary, the measured thrust is most dependent on amplitude of the resonance curve and the amplitude is very nonlinearly dependent on frequency.

Ok that makes sense.
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 06:33 pm
Ok.

Now, didn't you show that thrust was not strongly dependent on frequency? But photon momentum is strongly dependent on frequency (as is energy) so does this imply that thrust is not strongly dependent on photon momentum? Or can your approach separate momentum and energy?
No, what I showed was that the variation with frequency overwhelmed the ability to regress the data because of the nonlinearity of the amplitude vs frequency curve and the paucity of frequency data.

On the contrary, the measured thrust is most dependent on amplitude of the resonance curve and the amplitude is very nonlinearly dependent on frequency.

Ok that makes sense.

What the experimental data shows is that the experimental force depends on high Q and resonance.  The researchers don't really know ahead of time exactly at what frequency the highest amplitude will take place.  To make matters worse they don't appear to have the means to keep the frequency within the very narrow bandwidth that accompanies a high Q.  So completing an experiment is a tall order (I think this is the reason why Eagleworks did so few experiments: each one was a challenge).
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 06:39 pm
It is like somebody trying to tune to a radio transmission without knowing at what frequencies the transmissions are being broadcast.   The payoff is getting the highest amplitude, but you are lucky just to receive a transmission, finding out at what frequency the highest amplitudes take place was beyond the capabilities of any of these researchers: they only looked at two frequency ranges: 1.9 GHz (NASA) and 2.5 GHz (UK and China).
To make matters worse your receiver is difficult to keep tuned at the right frequency, once you receive the broadcast, the frequency may wonder off and your amplitude may wonder on and off as well, and certainly will vary in amplitude during the receiving time (which for Eagleworks was only ~30 to 40 seconds).
And to make matters much worse, the transmissions having the highest amplitude are the ones that have the narrowest bandwidth, so those frequencies are the hardest to find, they are the hardest to tune to, and once you find them they are the hardest to stay tuned to.

(http://lrrpublic.cli.det.nsw.edu.au/lrrSecure/Sites/Web/Forces_and_fields_creative_commons/7302/graphics/hertz_2.jpg)
Title: Re: EM Drive Developments
Post by: frobnicat on 10/16/2014 06:54 pm
Ok, this is preliminary :
I wrote a small program to generate some exhaustive search on formulas upon the relevant factors then sieving those formulas that fit the available data. This is completely theoretically agnostic but it does check for dimensional consistency (as far as kg m s units are concerned). The search goes on for any product of the terms a  b  L  Q  P  F  c  (respectively w_big   w_small   wavelength=c/Freq   Power   Thrust    Speed_of_light) with all possible whole exponents from -2 to +2 (going through 0) and tries to equal 1 (with the experimental data). It also tries an "extended" term (exterm) that is a combination of 2 homogeneous terms ( that is  a  b  or L ) at any power -2 to +2 through any of the operators  sum  difference  geometrical_average, and then to any power -2 to +2.
This does cover the formula by McCulloch but not Shawyer's.

Example of understanding the following dumps : McCulloch's formula reads
a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1  =  1
or said otherwise  F = P Q L/c (1/b - 1/a)
Note that the difference operator for the extended term is enclosed in absolute value (manual permutation needed to remove it).

The sieve goes like that : use the formula on each of the seven data points to generate a value hopefully close to 1. If it is not close to 1 but close to a given value (say 2) for all the data points then we have a constant fudge factor, but if the standard deviation around it is small this is still interesting : a strong relation still holds between the terms in such formula. The mean and deviation are calculated in log space, that is a mean of 0 is a best result (formula gives values around 1) while a mean of -1 or +1 says the formula gives values e (=2.72) times too low or too big.

Data input :


/// With maxes for ranges
t_data data_in[Nrec] =
{
    //                                 w_big  w_small  lambda      Q     power   force
    {"Shawyer (2008) a",        1.0 ,  16    ,  8    , C/2.45  ,  5900 ,  850   , 16       },
    {"Shawyer (2008) b",        1.0 ,  28    ,  4    , C/2.45  , 45000 , 1000   , 214      },
    {"Juan (2012) TE011",       1.0 ,  28    ,  4    , C/2.5   , 32000 , 1000   , 214      },
    {"Juan (2012) TE012",       1.0 ,  28    ,  4    , C/2.45  , 50000 , 1000   , 315      },
    {"Brady et al. (2014) a",   1.0 ,  24.75 , 16.5  , C/1.933 ,  7320 ,   16.9 ,   0.0912 },
    {"Brady et al. (2014) b",   1.0 ,  24.75 , 16.5  , C/1.937 , 18100 ,   16.7 ,   0.0501 },
    {"Brady et al. (2014) c",   1.0 ,  24.75 , 16.5  , C/1.88  , 22000 ,    2.6 ,   0.0554 },
};


Here we go :

Thresholds : mean=3.00   stddev=0.62

 a    b    L    Q    P    F    c                        mean   stddev
---------------------------------------------------------------------
a^0  b^-2 L^2  Q^1  P^1  F^-1 c^-1                      1.62   0.59

 a    b    L    Q    P    F    c      exterm            mean   stddev
---------------------------------------------------------------------
a^1  b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^ 1 + b^ 1)^-1   1.28   0.61
a^2  b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^ 2 + b^ 2)^-1   1.42   0.60
a^-1 b^-2 L^-1 Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-2   0.46   0.60 *
a^-2 b^-2 L^0  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-2  -0.14   0.60 *
a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1   0.74   0.58
a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1   0.15   0.61 *
a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2   0.13   0.58 *
a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2  -0.46   0.60 *
a^0  b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-1   1.17   0.61
a^-1 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-1   0.58   0.58
a^-1 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^ 1 + L^ 1)^1    2.06   0.58
a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^ 1 + L^ 1)^2    2.51   0.57
a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^ 2 + L^ 2)^1    1.90   0.57
a^0  b^0  L^2  Q^1  P^1  F^-1 c^-1   |a^-2 - b^-2|^1    1.31   0.61
a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1    0.46   0.61 <-
a^-1 b^1  L^2  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^2   -0.76   0.54 *
a^0  b^-2 L^-2 Q^1  P^1  F^-1 c^-1   |a^-2 - L^-2|^-2   2.48   0.61
a^1  b^-2 L^-1 Q^1  P^1  F^-1 c^-1   |a^-2 - L^-2|^-1   2.64   0.56
a^0  b^-2 L^0  Q^1  P^1  F^-1 c^-1   |a^-2 - L^-2|^-1   2.05   0.55
a^0  b^-2 L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - L^-1|^-1   2.50   0.57
a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1 sqrt(a^-2 L^-2)^-1   1.02   0.58
a^-1 b^-2 L^2  Q^1  P^1  F^-1 c^-1 sqrt(a^-1 L^-1)^-1   1.32   0.58

Checked : 94140625
Validated : 21769



McCulloch's formula is indicated with the arrow, stars show decent candidates.
We note that all selected solutions with both a decent absolute magnitude (mean near 0) and low deviation all share the same factors  F = Q P/c times something in meters^-1. This geometric factor, (1/b - 1/a) for McCulloch, allows for a lot of variations while still giving correct predictions. This is not surprising since L and a and b all are in a comparable range, this is hard to confirm a clear relation. While (1/b - 1/a) has a good look compared to others, I wouldn't say we have to explain why we should have this particular formula. More data required. On the other hand the QP/c term (and probably QPL/c) seems a clear winner to be accounted for.

Being a little more selective on standard deviation but allowing for huge fudge factors

Thresholds : mean=12.00  stddev=0.56

 a    b    L    Q    P    F    c                        mean   stddev
---------------------------------------------------------------------

 a    b    L    Q    P    F    c      exterm            mean   stddev
---------------------------------------------------------------------
a^1  b^-1 L^2  Q^0  P^1  F^-1 c^-1   (a^-2 + b^-2)^1   -6.98   0.53
a^2  b^1  L^1  Q^0  P^1  F^-1 c^-1   (a^-2 + b^-2)^2   -6.19   0.55
a^1  b^-2 L^2  Q^0  P^1  F^-1 c^-1   (a^-1 + b^-1)^1   -6.84   0.54
a^2  b^-1 L^1  Q^0  P^1  F^-1 c^-1   (a^-1 + b^-1)^2   -5.92   0.54
a^1  b^-2 L^2  Q^0  P^1  F^-1 c^-1   (b^-1 + L^-1)^1   -6.67   0.54
a^2  b^-2 L^1  Q^0  P^1  F^-1 c^-1   (b^ 1 + L^ 1)^-1  -7.60   0.55
a^2  b^-2 L^2  Q^0  P^1  F^-1 c^-1   (b^ 2 + L^ 2)^-1  -7.51   0.55
a^2  b^0  L^0  Q^0  P^1  F^-1 c^-1   |a^-2 - b^-2|^1   -7.40   0.56
a^1  b^-1 L^1  Q^0  P^1  F^-1 c^-1   |a^-1 - b^-1|^1   -8.33   0.55
a^1  b^1  L^0  Q^0  P^1  F^-1 c^-1   |a^-1 - b^-1|^2   -9.48   0.56 *
a^-1 b^1  L^2  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^2   -0.76   0.54
a^0  b^-2 L^0  Q^1  P^1  F^-1 c^-1   |a^-2 - L^-2|^-1   2.05   0.55
a^2  b^-2 L^-2 Q^1  P^1  F^-1 c^-1   |a^-1 - L^-1|^-2   4.56   0.52
a^1  b^-2 L^0  Q^1  P^1  F^-1 c^-1   |a^-1 - L^-1|^-1   3.09   0.55
a^2  b^-2 L^2  Q^0  P^1  F^-1 c^-1 sqrt(a^-2 b^-2)^1   -7.18   0.55
a^2  b^-2 L^1  Q^0  P^1  F^-1 c^-1 sqrt(a^-1 b^-1)^1   -7.14   0.54
a^2  b^-2 L^1  Q^0  P^1  F^-1 c^-1 sqrt(b^-1 L^-1)^1   -6.84   0.55
a^1  b^-2 L^2  Q^0  P^1  F^-1 c^-1 sqrt(b^-1 L^-1)^1   -7.43   0.55


The starred one seems the more symmetric. It reads
F = 13100 P/c ab(1/b-1/a)^2

Interestingly it requires no Q value nor wavelength. The constant factor compensates for the absence of Q in absolute magnitude. It is dimensionless. I don't know how it could be interpreted, otherwise than a coincidence in looking at 21769 formulas.
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 06:57 pm
And because there are only 2 cavity shapes and 3 cavity sizes you are going to have the same problem trying to sus out a dependency on cavity height, aren't you.

It seems to me that the greater the height of the cavity, the more difficult it will be to tune. That is, if the cavity is one wavelength high then a small error in frequency will give one delta error in wavelength and one delta off of the resonance peak, but if the cavity is 12 wavelengths high, that same small error in frequency will give 12 deltas error off of resonance peak.

I think that current technology can deal with this if it is brought to bear on the problem.
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 07:10 pm
Quote from: frobnicat link=topic=29276.msg1271

...
McCulloc's formula is indicated with the arrow, stars show decent candidates.
We note that all selected solutions with both a decent absolute magnitude (mean near 0) and low deviation all share the same factors  F = Q P/c times something in meters^-1. This geometric factor, (1/b - 1/a) for McCulloch, allows for a lot of variations while still giving correct predictions. This is not surprising since L and a and b all are in a comparable range, this is hard to confirm a clear relation. While (1/b - 1/a) has a good look compared to others, I wouldn't say we have to explain why we should have this particular formula. More data required. On the other hand the QP/c term (and probably QPL/c) seems a clear winner to be accounted for.



OK.  First applause to you for great effort, using the computational-brute-force approach.  Great frobnicating  :)

1) It looks like there is no formula found using the brute-force computational approach (examining  21769 formulas) that does appreciable better than McCulloch's regarding appreciably minimizing Standard Deviation

2) I don't like allowing any fudge factors whatsoever.  So it looks like the alternatives (which only improve the mean, but not the StdDev) are:

a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1   0.15   0.61 *
a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2   0.13   0.58 *

compared to McCulloch's

a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1    0.46   0.61 <-

The first formula (in blue) is interesting since it involves the surface areas
But please notice that the formula involves the addition of surface a to surface L,
Strange formula.  Can't immediately make sense of it...
Why pick (a^-2 + L^-2)^-1  ????

These formulas are telling us that the big diameter surface (a) is more important



NOTE: For McCulloch's formula to be interpreted as F = P Q L/c (1/b - 1/a).  We must satisfy the following requirement:  MeasuredFrequency = c/L; therefore L = c / MeasuredFrequency; as prescribed by frobnicat
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 07:39 pm
Yes, Applause for your great effort. --- now, if it could only talk ...

I'll try to convert these to conventional nomenclature.

Quote
a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1   0.15   0.61 *
a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2   0.13   0.58 *

compared to McCulloch's

a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1    0.46   0.61 <-


AIUI - a = w_big, b = w_small and the others are as always, so:

a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1   0.15   0.61 *
force = QP/fc * (L^2/ab^2)/(a^2 + L^2)

and

a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2   0.13   0.58 *
force = QP/fc * (L/a*b^2)/(1/a + 1/L)^2

and McCulloch's formula,
a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1    0.46   0.61 <-
force = QP/fc * L * (1/a - 1/b) which is not what you wrote.

and this is interesting, but I'm still wondering about the effect of L = cavity height, which this doesn't address.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/16/2014 07:43 pm
Great frobnicating

This is a family wave site, buddy.  Don't make me come back from the future and tell you again.
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 07:47 pm
Yes, Applause for your great effort. --- now, if it could only talk ...

I'll try to convert these to conventional nomenclature.

Quote
a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1   0.15   0.61 *
a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2   0.13   0.58 *

compared to McCulloch's

a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1    0.46   0.61 <-


AIUI - a = w_big, b = w_small and the others are as always, so:

a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1   0.15   0.61 *
force = QP/fc * (L^2/ab^2)/(a^2 + L^2)

and

a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2   0.13   0.58 *
force = QP/fc * (L/a*b^2)/(1/a + 1/L)^2

and McCulloch's formula,
a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1    0.46   0.61 <-
force = QP/fc * L * (1/a - 1/b) which is not what you wrote.

and this is interesting, but I'm still wondering about the effect of L = cavity height, which this doesn't address.

No, F=experimentally measured force.  F not equal frequency, kernosabe

Kernosabe not allowed to include frequency (f) in the denominator of any of these formulas if also simultaneously including c/L

The cat already prescribed MeasuredFrequency = c/L; therefore L = c / MeasuredFrequency;

f not allowed here. And JohnFornaro coming from the future with his time machine warned that

frobnicating not allowed either
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/16/2014 07:52 pm
It is even a mystery why NASA Eagleworks chose to test at those particular frequencies, as remarked by Ludwick.

Somebody must think that there's some kind of "sweet spot" around those two frequencies.  Why they apparently did not see to it that their bancdwidth was better controlled, I have no idea.
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 08:03 pm
Try again.
AIUI - a = w_big, b = w_small and the others are as always, so:

a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1   0.15   0.61 *
force = QP/c * (L^2/ab^2)/(a^2 + L^2)

and

a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2   0.13   0.58 *
force = QP/c * (L/a*b^2)/(1/a + 1/L)^2

and McCulloch's formula,
a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1    0.46   0.61 <-
force = QP/c * L * (1/a - 1/b) which is not what you wrote.

and this is interesting, but I'm still wondering about the effect of L = cavity height, which this doesn't address.

Quote
MeasuredFrequency = c/L; therefore L = c / MeasuredFrequency;

But I don't buy that. L need only have units of length. That's why I asked you to test L =  cavity height .

And by the way, I am not kernosabe. Or kemosabe either .
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 08:09 pm
Quote
MeasuredFrequency = c/L; therefore L = c / MeasuredFrequency;

But I don't buy that. L need only have units of length. That's why I asked you to test L =  cavity height .
OK, but that becomes @aero's formula then. McCulloch's formula has MeasuredFrequency = c/L; therefore L = c / MeasuredFrequency

@frobnicat is best to explore L as floating parameter, with his Infinite number of formulas exploration

And by the way, I am not kernosabe. Or kemosabe either .
Oh, OK, I fixed that  :)
Title: Re: EM Drive Developments
Post by: frobnicat on 10/16/2014 08:32 pm
Try again.
AIUI - a = w_big, b = w_small and the others are as always, so:

a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1   0.15   0.61 *
force = QP/c * (L^2/ab^2)/(a^2 + L^2)

er, try again ?
force = QP/c * (L^2/ab^2)/(1/a^2 + 1/L^2)
        = QP/c * (L^2/ab^2) (aL)^2/(a^2 + L^2)
        = QP/c * (L^4/b^2)/(a^2 + L^2)
        = QP/c * L^4/((ab)^2 + (Lb)^2)

Is that it ?
My system isn't hooked to symbolic automation like mathematica, sorry.

Quote

a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2   0.13   0.58 *
force = QP/c * (L/a*b^2)/(1/a + 1/L)^2


seems ok

Quote
and McCulloch's formula,
a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1    0.46   0.61 <-
force = QP/c * L * (1/a - 1/b) which is not what you wrote.

I wrote
F = P Q L/c (1/b - 1/a)
because there is an absolute value and I know what makes that positive and didn't wrote the 4 lines of code to automatise the process in quick and dirty mode. Program is already a mess and needs refactoring.

Quote
and this is interesting, but I'm still wondering about the effect of L = cavity height, which this doesn't address.

Quote
MeasuredFrequency = c/L; therefore L = c / MeasuredFrequency;

But I don't buy that. L need only have units of length. That's why I asked you to test L =  cavity height .


For me L is just a convenient way to input the frequency. The conversion factor, c, is unlikely to see great changes soon, and taking the inverse makes no difference further than negating the exponents. It is convenient precisely because it has natural units of length and can mix easily with a and b.

edit: I like to see  F = P/c  times dimensionless_factor  because for the only both experimentally proven and theoretically understood propellantless propulsion (you know, my friend, the photon rocket) we have this beautiful (but also hopelessly scant) formula F = P/c times one.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/16/2014 09:42 pm
I'm surprised nobody bites on this nice looking one

F = 13100 P/c ab(1/b-1/a)^2
or
F = 13100 P/c (a-b)^2/(ab)

( a^1  b^1  L^0  Q^0  P^1  F^-1 c^-1   |a^-1 - b^-1|^2 ) / mean value (without log)
 -> 1.16   1.05   1.05   0.71   1.35   2.42   0.34

For comparison, McCulloch's (which is great, I don't contest)
(a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1 ) / mean value (without log)
->  0.50   1.16   0.81   0.87   0.89   3.95   0.70

(as per the order of the seven rows tabulated data)

Alright there is a big fudge factor of 13100, that looks like the ballpark of Q values, but note that it doesn't move, it is still 13100 even with Q values going from 5900 to 50000. First and fourth values 1.16 and 0.71 ratio 1.63, no more relative deviation than MiHsC 0.50 and 0.87 ratio 1.74

To me this is indicative that this former formula is as good at predicting an effect independent of Q than the later at indicating a linear dependency on Q. Introducing a constant is a lot of information added to fit the data (considering the sparsity of data the risk of overfitting is great) but it also discards two parameters Q and Lambda (or frequency) so is simpler in this respect. What would 13100 stand for ? Let me see... something vaguely around the squared inverse of the fine structure constant for instance ?

Do I have an agenda ? Of course I have an agenda. But this isn't numerology.
And this can wait until tomorrow.
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 09:56 pm
I'm surprised nobody bites on this nice looking one

F = 13100 P/c ab(1/b-1/a)^2
or
F = 13100 P/c (a-b)^2/(ab)

( a^1  b^1  L^0  Q^0  P^1  F^-1 c^-1   |a^-1 - b^-1|^2 ) / mean value (without log)
 -> 1.16   1.05   1.05   0.71   1.35   2.42   0.34

For comparison, McCulloch's (which is great, I don't contest)
(a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1 ) / mean value (without log)
->  0.50   1.16   0.81   0.87   0.89   3.95   0.70

(as per the order of the seven rows tabulated data)

Alright there is a big fudge factor of 13100, that looks like the ballpark of Q values, but note that it doesn't move, it is still 13100 even with Q values going from 5900 to 50000. First and fourth values 1.16 and 0.71 ratio 1.63, no more relative deviation than MiHsC 0.50 and 0.87 ratio 1.74

To me this is indicative that this former formula is as good at predicting an effect independent of Q than the later at indicating a linear dependency on Q. Introducing a constant is a lot of information added to fit the data (considering the sparsity of data the risk of overfitting is great) but it also discards two parameters Q and Lambda (or frequency) so is simpler in this respect. What would 13100 stand for ? Let me see... something vaguely around the squared inverse of the fine structure constant for instance ?

Do I have an agenda ? Of course I have an agenda. But this isn't numerology.
And this can wait until tomorrow.

Well, obviously

 (a-b)^2/(ab)  = ( (a/b -1) + (b/a -1)) 

or

 (a-b)^2/(ab)  = ( (RR - 1) + (1/RR - 1))

which is a symmetrized measure of the distance from unity of the relative ratio (RR = a / b) between the two diameters of the bases of the truncated cone.  (This measure is zero for RR =1 and it goes to Infinity either as RR --> Infinity or as RR --> 0)

But how can the photons produce a net thrust force ?

and a force exceeding the one of a photon rocket ?

Title: Re: EM Drive Developments
Post by: RotoSequence on 10/16/2014 10:07 pm
I guess memetic replies (http://weknowgifs.com/wp-content/uploads/2013/03/its-magic-shia-labeouf-gif.gif) aren't appreciated by the mods.

I don't trust the photon thrust explanation when the measured thrust is larger than that of a photon rocket.
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 10:26 pm
I'm surprised nobody bites on this nice looking one

F = 13100 P/c ab(1/b-1/a)^2
or
F = 13100 P/c (a-b)^2/(ab)

( a^1  b^1  L^0  Q^0  P^1  F^-1 c^-1   |a^-1 - b^-1|^2 ) / mean value (without log)
 -> 1.16   1.05   1.05   0.71   1.35   2.42   0.34

For comparison, McCulloch's (which is great, I don't contest)
(a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1 ) / mean value (without log)
->  0.50   1.16   0.81   0.87   0.89   3.95   0.70

(as per the order of the seven rows tabulated data)

Alright there is a big fudge factor of 13100, that looks like the ballpark of Q values, but note that it doesn't move, it is still 13100 even with Q values going from 5900 to 50000. First and fourth values 1.16 and 0.71 ratio 1.63, no more relative deviation than MiHsC 0.50 and 0.87 ratio 1.74

To me this is indicative that this former formula is as good at predicting an effect independent of Q than the later at indicating a linear dependency on Q. Introducing a constant is a lot of information added to fit the data (considering the sparsity of data the risk of overfitting is great) but it also discards two parameters Q and Lambda (or frequency) so is simpler in this respect. What would 13100 stand for ? Let me see... something vaguely around the squared inverse of the fine structure constant for instance ?

Do I have an agenda ? Of course I have an agenda. But this isn't numerology.
And this can wait until tomorrow.

Well, obviously

 (a-b)^2/(ab)  = ( (a/b -1) + (b/a -1)) 

or

 (a-b)^2/(ab)  = ( (AR - 1) + (1/AR - 1))

which is a symmetrized measure of the distance from unity of the aspect ratio (AR = a / b) between the two diameters of the bases of the truncated cone.  (This measure is zero for AR =1 and it goes to Infinity either as AR --> Infinity or as AR --> 0)

But how can the photons produce a net thrust force ?

and a force exceeding the one of a photon rocket ?

Well Prof. M told us, but we threw it out with this.

Quote
The cat already prescribed MeasuredFrequency = c/L; therefore L = c / MeasuredFrequency;

And I am sorry, but I don't see anything here but someone quoting someone else. Can you show me the original source statement, or better, proof? I can show you the original source statement that L is the Unruh wavelength here:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html (http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-data-1.html)

Quote
In MiHsC the inertial mass (mi) is modified as mi=m(1-L/4T) where m is the unmodified mass, L is the Unruh wavelength determined by the acceleration, and T is the Hubble distance

snip

What if the resonant cavity walls acted like a Hubble horizon, especially for Unruh waves of a similar length (as they are in this case)? Then the inertial mass of the photons would increase towards the cavity's wide end, since more Unruh waves would fit there, since mi=m(1-L/2w), where w is the cavity width. The force carried by the photons then increases by this factor as they go from the narrow end (width w_small) towards the wide end (width w_big). The force difference between ends is

 dF = (PQ/c)*((L/w_big)-(L/w_small)) = (PQ/f)*((1/w_big)-(1/w_small)).

If we consider L to be the RF drive wavelength, then how do we justify talking about the Unruh effect and how it may interact with the photons to cause the excessive thrust? If L is not the RF wavelength then it could be just about anything although it seems that it could be related to cavity dimensions. Ask Prof. M, but I think it doesn't have to be.
Title: Re: EM Drive Developments
Post by: Rodal on 10/16/2014 10:51 pm
If we consider L to be the RF drive wavelength, then how do we justify talking about the Unruh effect and how it may interact with the photons to cause the excessive thrust? If L is not the RF wavelength then it could be just about anything although it seems that it could be related to cavity dimensions. Ask Prof. M, but I think it doesn't have to be.
OK point well taken.  You are correct, that is the Unruh wavelength explanation.

Here is the practical problem. 

There are an infinite number of Unruh wavelengths, and they have an energy spectrum.

I imagine that there is an Unruh wavelength that best fits.  Which Unruh wavelength to take?  Assume that the longest wavelength that fits is the most energetic?  That fits in what lengh?  (Which way do the wavelengths fit in the cavity? along the longitudinal axis of revolution of the cone?)

How do we decide what "L" to use in the analysis?  For NASA Eagleworks? For Shawyer?

I understand these are the Shawyer dimensions calculated:


@aero                                                                McCulloch's table

w_big = 0.28 meters                                          0.28  meters        AGREE
w_small = 0.18375 meters                                 0.04 meters         DISAGREE
height = 0.2975 meters

w_big    0.2800  meters                                      0.16 meters         DISAGRE
w_small    0.0778 meters                                    0.08 meters         AGREE
height 0.3811 meters

which are discrepant as noted

and what are the L's to use?
Title: Re: EM Drive Developments
Post by: aero on 10/16/2014 11:44 pm
If it is an Unruh wave, it is initiated by acceleration of the cavity walls. Which walls are accelerated by the RF photons? I think it is the end circular walls. That is, the RF waves resonate parallel to the axis of symmetry. So the Unruh waves also propagate parallel to the axis of symmetry.

What are the Unruh wave wavelengths? They are either constrained by the cavity end separation or they are unique to the end from which they propagate. They need not propagate from both ends, that is, one end could act as a horizon and emit a wave while the other does not but this seems unlikely. It seems more likely that the ends emit Unruh waves of different wavelength. If they are not coupled to each other, that is. But if they are coupled then cavity dimensions play a role in fixing the wavelength?

But don't get to hung up on the actual value of the wavelength. If it exists at all, then imagine what the photon must see as it approached the wall. Nothing of course, the photon is moving at the speed of light so can only see behind and to angles to the rear. But from the Unruh effect, that wall is hot so like a blind cat on a hot stove, the photon departs with more energy than it arrived with. Its frequency or its mass is up-shifted as is its momentum. How much? I think that gets us back to the Unruh effect. And what is really up-shifted? Its inertial mass of course because that is what put us on this path in the first place.
Title: Re: EM Drive Developments
Post by: aero on 10/17/2014 12:25 am
@aero                                                                McCulloch's table
Demonstrator by ratio
w_big = 0.28 meters                                          0.28  meters        AGREE
w_small = 0.18375 meters                                 0.04 meters         DISAGREE
height = 0.2975 meters

Demonstrator by photo
w_big = 0.28 meters                                          0.28  meters        AGREE
w_small = 0.0778 meters                                 0.04 meters         DISAGREE Whatever works
height = 0.381 meters

Experimental by photo
w_big    0.16 meters                                      0.16 meters         DISAGRE Agree
w_small    0.0778 meters                                    0.08 meters         AGREE
height    0.177 meters


You don't think Shawyer just extended the big end of the Experimental model to make the Demonstrator model, do you?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/17/2014 12:55 am
And by the way, I am not kernosabe. Or kemosabe either.

He knoweth not for whom the bell tolleth.

If we consider L to be the RF drive wavelength, then how do we justify talking about the Unruh effect and how it may interact with the photons to cause the excessive thrust? If L is not the RF wavelength then it could be just about anything although it seems that it could be related to cavity dimensions. Ask Prof. M, but I think it doesn't have to be.

OK point well taken.  You are correct, that is the Unruh wavelength explanation.

In my equationless style, I'm still not on board with the HYPOTHETICAL Unruh wave explanation.  Further, since there must be an integral number of these faith based waves in the cavity, and since resonance is THE operative factor, there should have been, from the summa cavea arachis (http://en.wikipedia.org/wiki/Peanut#Peanut_gallery) at any rate, much tighter control over the bandwidth of the wavelength sent to the device.

What you guys are talking about is not making sense.  Not sayin' you're talking nonsense.  You're still talking about the copper geometry as having some special refractive index which works at 1.9xxx GHz, using waves which have not been seen.

It's rough being me.  But somebody has to do it.
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 01:18 am
And by the way, I am not kernosabe. Or kemosabe either.

He knoweth not for whom the bell tolleth.

If we consider L to be the RF drive wavelength, then how do we justify talking about the Unruh effect and how it may interact with the photons to cause the excessive thrust? If L is not the RF wavelength then it could be just about anything although it seems that it could be related to cavity dimensions. Ask Prof. M, but I think it doesn't have to be.



OK point well taken.  You are correct, that is the Unruh wavelength explanation.

In my equationless style, I'm still not on board with the HYPOTHETICAL Unruh wave explanation.  Further, since there must be an integral number of these faith based waves in the cavity, and since resonance is THE operative factor, there should have been, from the summa cavea arachis (http://en.wikipedia.org/wiki/Peanut#Peanut_gallery) at any rate, much tighter control over the bandwidth of the wavelength sent to the device.

What you guys are talking about is not making sense.  Not sayin' you're talking nonsense.  You're still talking about the copper geometry as having some special refractive index which works at 1.9xxx GHz, using waves which have not been seen.

It's rough being me.  But somebody has to do it.

Kernosabe, the drums go ooompah ooompah ooompah,  the bongos go bonga bonga bonga

https://www.youtube.com/watch?v=2Ks8gsK22PA

and the cavity goes something like this

https://www.youtube.com/watch?v=6re7NOu34Do#t=1023
Title: Re: EM Drive Developments
Post by: aero on 10/17/2014 05:35 am
Quote
OK point well taken.  You are correct, that is the Unruh wavelength explanation.

Here is the practical problem. 

There are an infinite number of Unruh wavelengths, and they have an energy spectrum.

I can't find Prof. M's equation with Q*L replaced with a constant, but this equation

F = 13100 P/c ab(1/b-1/a)^2

gives us an idea of how to find the values of L. First find them numerically, then relate them to the dimensions of the device, if they relate.

Replace the number, 13100 in the equation with the product Q*L then the values of L that satisfy the equations for each experiment are:

     "Shawyer (2008) a"    1.913 m
     "Shawyer (2008) b"    0.277 m
       "Juan (2012) TE011"    0.390 m
       "Juan (2012) TE012"    0.367 m
       "Brady et al. (2014) a"    1.326 m
       "Brady et al. (2014) b"    0.298 m
     "Brady et al. (2014) c"    1.742 m

As can be seen, Shawyer b and both Jauns have L values that fit the within cavity dimensions, which is around 0.38 m. Unfortunately by forcing the fit above I have forced all of the errors from the experiments and the analysis into the values of L.

I wonder if this advances our search. Two of the 7 experiments are satisfied with L = cavity height, and one has L < cavity height. The only other one that is close is the Brady outlier. I don't know what to make of that. I do know that I should use Prof. M's original formula, not the one with the constant factor. Maybe later.

Its later. Prof. M's 1-D equation is not satisfied with L chosen to force fit the experimental data. That is, of course the numbers are calculated but the values of L are all to small to relate to the cavity. In fact, except for Shawyer a, they are all smaller than the RF wavelength. Close, but smaller. Well, the Brady outlier is much smaller, not even close to the RF wavelength.

Is there a chance that the formula above, using ab(1/b-1/a)^2, an area like expression, could end up being similar to Prof. M's 3-D model that he is working on? That is, could

dF = Q*L* P/c ab(1/b-1/a)^2

be a 3-D representation of the MiHsC model. I guess I should ask Prof. M himself.
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 12:04 pm
....
I wrote a small program to generate some exhaustive search on formulas upon the relevant factors then sieving those formulas that fit the available data. This is completely theoretically agnostic but it does check for dimensional consistency (as far as kg m s units are concerned). The search goes on for any product of the terms a  b  L  Q  P  F  c  (respectively w_big   w_small   wavelength=c/Freq   Power   Thrust    Speed_of_light) with all possible whole exponents from -2 to +2 (going through 0) and tries to equal 1 (with the experimental data). It also tries an "extended" term (exterm) that is a combination of 2 homogeneous terms ( that is  a  b  or L ) at any power -2 to +2 through any of the operators  sum  difference  geometrical_average, and then to any power -2 to +2.
This does cover the formula by McCulloch but not Shawyer's.

Example of understanding the following dumps : McCulloch's formula reads
a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1  =  1
or said otherwise  F = P Q L/c (1/b - 1/a)
Note that the difference operator for the extended term is enclosed in absolute value (manual permutation needed to remove it).

The sieve goes like that : use the formula on each of the seven data points to generate a value hopefully close to 1. If it is not close to 1 but close to a given value (say 2) for all the data points then we have a constant fudge factor, but if the standard deviation around it is small this is still interesting : a strong relation still holds between the terms in such formula. The mean and deviation are calculated in log space, that is a mean of 0 is a best result (formula gives values around 1) while a mean of -1 or +1 says the formula gives values e (=2.72) times too low or too big.

Data input :


/// With maxes for ranges
t_data data_in[Nrec] =
{
    //                                 w_big  w_small  lambda      Q     power   force
    {"Shawyer (2008) a",        1.0 ,  16    ,  8    , C/2.45  ,  5900 ,  850   , 16       },
    {"Shawyer (2008) b",        1.0 ,  28    ,  4    , C/2.45  , 45000 , 1000   , 214      },
    {"Juan (2012) TE011",       1.0 ,  28    ,  4    , C/2.5   , 32000 , 1000   , 214      },
    {"Juan (2012) TE012",       1.0 ,  28    ,  4    , C/2.45  , 50000 , 1000   , 315      },
    {"Brady et al. (2014) a",   1.0 ,  24.75 , 16.5  , C/1.933 ,  7320 ,   16.9 ,   0.0912 },
    {"Brady et al. (2014) b",   1.0 ,  24.75 , 16.5  , C/1.937 , 18100 ,   16.7 ,   0.0501 },
    {"Brady et al. (2014) c",   1.0 ,  24.75 , 16.5  , C/1.88  , 22000 ,    2.6 ,   0.0554 },
};
...

Could you please re-run all the cases with the same input except to take this outlier out ?:

   {"Brady et al. (2014) b",   1.0 ,  24.75 , 16.5  , C/1.937 , 18100 ,   16.7 ,   0.0501 }

In other words, please re-run with:

Data input :

{
    //                                 w_big  w_small  lambda      Q     power   force
    {"Shawyer (2008) a",        1.0 ,  16    ,  8    , C/2.45  ,  5900 ,  850   , 16       },
    {"Shawyer (2008) b",        1.0 ,  28    ,  4    , C/2.45  , 45000 , 1000   , 214      },
    {"Juan (2012) TE011",       1.0 ,  28    ,  4    , C/2.5   , 32000 , 1000   , 214      },
    {"Juan (2012) TE012",       1.0 ,  28    ,  4    , C/2.45  , 50000 , 1000   , 315      },
    {"Brady et al. (2014) a",   1.0 ,  24.75 , 16.5  , C/1.933 ,  7320 ,   16.9 ,   0.0912 },

    {"Brady et al. (2014) c",   1.0 ,  24.75 , 16.5  , C/1.88  , 22000 ,    2.6 ,   0.0554 },
};

I would like to see how the formula parameters behave with this outlier taken out.

Thanks
Title: Re: EM Drive Developments
Post by: aero on 10/17/2014 04:06 pm
Quote
I would like to see how the formula parameters behave with this outlier taken out.

Yes. The Brady outlier certainly shows us something but it doesn't show us how the thruster works ideally. It shows how it works when something goes wrong. That's important to know but not useful in the context of discovering the ideal operational model and parameters.

For our purposes now of discovering the ideal operational model and parameters, we should avoid outliers when they have been identified. Once the data is evaluated with Brady b" removed we can consider if perhaps Shawyer a" isa  less than ideal case as well.
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 04:44 pm
Quote
I would like to see how the formula parameters behave with this outlier taken out.

Yes. The Brady outlier certainly shows us something but it doesn't show us how the thruster works ideally. It shows how it works when something goes wrong. That's important to know but not useful in the context of discovering the ideal operational model and parameters.

For our purposes now of discovering the ideal operational model and parameters, we should avoid outliers when they have been identified. Once the data is evaluated with Brady b" removed we can consider if perhaps Shawyer a" isa  less than ideal case as well.

I think that placing this outlier in the data masks the importance of Q.
Taking it out of the data may show again the importance of Q.

As @aero states, imagine that this thruster works based on resonance (as was the expectation by all the researchers in the US, UK and China) and that one cannot control the bandwidth adequately at high Q (as pointed out by Ludwick).

Due to frequency drift, one ends up with tests that are in resonance and tests (like the outlier) that drift out of resonance and produce very low experimental force.

To understand the mechanism we have to look at the data with the outlier included (done) and with the outlier excluded.
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 05:31 pm
@aero                                                                McCulloch's table
Demonstrator by ratio
w_big = 0.28 meters                                          0.28  meters        AGREE
w_small = 0.18375 meters                                 0.04 meters         DISAGREE
height = 0.2975 meters

Demonstrator by photo
w_big = 0.28 meters                                          0.28  meters        AGREE
w_small = 0.0778 meters                                 0.04 meters         DISAGREE Whatever works
height = 0.381 meters

Experimental by photo
w_big    0.16 meters                                      0.16 meters         DISAGRE Agree
w_small    0.0778 meters                                    0.08 meters         AGREE
height    0.177 meters


You don't think Shawyer just extended the big end of the Experimental model to make the Demonstrator model, do you?

For the Experimental Thruster, using Fig. 6 of Shawyer's report (http://www.emdrive.com/IAC-08-C4-4-7.pdf) I get:

Large Base Diameter = 16 cm = 0.16 m
Small Base Diameter = 11 cm = 0.11 m
Length = 15.8 cm = 0.158 m

Where is the photograph you used for Shawyer's demonstrator drive?
Title: Re: EM Drive Developments
Post by: aero on 10/17/2014 05:36 pm
Quote
Where is the photograph you used for Shawyer's demonstrator drive?

At the bottom of the page here: http://emdrive.com/ (http://emdrive.com/)
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 05:43 pm
@aero                                                                McCulloch's table
Demonstrator by ratio
w_big = 0.28 meters                                          0.28  meters        AGREE
w_small = 0.18375 meters                                 0.04 meters         DISAGREE
height = 0.2975 meters

Demonstrator by photo
w_big = 0.28 meters                                          0.28  meters        AGREE
w_small = 0.0778 meters                                 0.04 meters         DISAGREE Whatever works
height = 0.381 meters

Experimental by photo
w_big    0.16 meters                                      0.16 meters         DISAGRE Agree
w_small    0.0778 meters                                    0.08 meters         AGREE
height    0.177 meters


You don't think Shawyer just extended the big end of the Experimental model to make the Demonstrator model, do you?



For the Shawyer Demonstrator Thruster, using the picture at the bottom of the page here: http://emdrive.com/ I get:

(http://emdrive.com/images/emdrive.jpg)

Large Base Diameter = 28 cm = 0.28 m
Small Base Diameter = 15.9 cm = 0.159 m (2 times @aero's estimate)
Length = 22.6 cm = 0.226 m

RelativeRatio = Large Base Diameter/Small Base Diameter = 1.76
Symmetrized Measure of Base Diameter Difference = ((RR-1)+(1/RR-1))= 0.329
(1/Small Base Diameter - 1/Large Base Diameter)=2.72 (1/m)

I think that the only length that is relevant in a truncated cone analysis is the length of the truncated cone itself and not the length of the cylinder attached to it, so "Length" means Length of truncated cone


For the Experimental Thruster, using Fig. 6 of Shawyer's report (http://www.emdrive.com/IAC-08-C4-4-7.pdf) I get:

Large Base Diameter = 16 cm = 0.16 m
Small Base Diameter = 11 cm = 0.11 m  (+41% greater than @aero's estimate)
Length = 15.8 cm = 0.158 m (-11% less than @aero's estimate)

RelativeRatio = Large Base Diameter/Small Base Diameter = 1.45
Symmetrized Measure of Base Diameter Difference = ((RR-1)+(1/RR-1))= 0.142
(1/Small Base Diameter - 1/Large Base Diameter)=2.84 (1/m)
Title: Re: EM Drive Developments
Post by: frobnicat on 10/17/2014 05:54 pm
Without Brady b, Here we go :

6 entries

Thresholds : mean=0.50   stddev=0.35

 a    b    L    Q    P    F    c                        mean   stddev
---------------------------------------------------------------------

 a    b    L    Q    P    F    c      exterm            mean   stddev
---------------------------------------------------------------------
a^0  b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + b^-1)^-1   0.49   0.29
a^2  b^-1 L^1  Q^1  P^1  F^-1 c^-1   (a^ 1 + b^ 1)^-2   0.19   0.27
a^1  b^-1 L^2  Q^1  P^1  F^-1 c^-1   (a^ 1 + b^ 1)^-2  -0.43   0.24
a^-1 b^-2 L^-1 Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-2   0.24   0.31
a^-2 b^-2 L^0  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-2  -0.37   0.16
a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-2 + L^-2)^-1  -0.10   0.16
a^-1 b^-2 L^1  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-2  -0.08   0.26
a^-1 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (a^-1 + L^-1)^-1   0.35   0.20
a^0  b^-2 L^1  Q^1  P^1  F^-1 c^-1   (b^-1 + L^-1)^-1   0.33   0.26
a^-1 b^-2 L^2  Q^1  P^1  F^-1 c^-1   (b^-1 + L^-1)^-1  -0.28   0.35
a^-1 b^1  L^2  Q^1  P^1  F^-1 c^-1   |a^-2 - b^-2|^1   -0.07   0.29
a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1    0.24   0.25 <-
a^-1 b^0  L^2  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1   -0.38   0.17
a^-1 b^-2 L^2  Q^1  P^1  F^-1 c^-1 sqrt(b^-1 L^-1)^-1   0.49   0.29

Checked : 94140625
Validated : 21769


Checked is number of all the combinations, Validated is number of formulas that respect dimensional consistency for kg m s units. Mean and standard deviation thresholds are lowered to yield approximately same number of selected formulas as previous run with all seven data points.

Relative values for MiHsC
(a^0  b^0  L^1  Q^1  P^1  F^-1 c^-1   |a^-1 - b^-1|^1 ) / mean value (without log)
  0.63   1.45   1.01   1.10   1.12   0.88
As per order Shawyer a & b, Juan 11 & 12, Brady a & c
This is quite good except Shawyer's results : should we skip those two outliers ?  :D
 
Rodal you are right that Q is more significant without Brady b : the Qless  F = 13100 P/c (a-b)^2/(ab)  no longer appears easily when relaxing mean constraint up to 12 (fudge factor in 163000 and 1/163000).
a^1  b^1  L^0  Q^0  P^1  F^-1 c^-1   |a^-1 - b^-1|^2   -9.63   0.46
is to be found amongst 200 formulas of similar or better levels of deviation.
It is not robust. But I still like it !

Waiting for adjusted inputs...
Title: Re: EM Drive Developments
Post by: aero on 10/17/2014 05:58 pm
Quote
I think that the only length that is relevant is the length of the truncated cone itself and not the length of the cylinder attached to it, so "Length" means Length of truncated cone

I don't know. I speculate that knowing the big diameter, we might be able to back the small diameter out of Shawyer's performance model using his published data. He does say that the thrust agrees with his performance model and it does use diameters of the ends of the cavity.

Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 05:58 pm
...
This is quite good except Shawyer's results : should we skip those two outliers ?  :D
 
.....

What statistical argument can you use to state that those two are outliers?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/17/2014 06:08 pm
Quote
Where is the photograph you used for Shawyer's demonstrator drive?

At the bottom of the page here: http://emdrive.com/ (http://emdrive.com/)

Don't know if it's been mentioned, but the demo unit has a tuning plunger in the straight section.  You can see the motor and drive gears etc hanging out on the rear.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/17/2014 06:10 pm
...
This is quite good except Shawyer's results : should we skip those two outliers ?  :D
 
.....

What statistical argument can you use to state that those two are outliers?

It was a sarcastical argument, not a statistical argument. I'm not seriously considering to lower the data count to 4 samples.
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 06:13 pm
...
Waiting for adjusted inputs...
We still would like to hear whether there is an argument that can be made, explaining the formulas that model the experimental results either as:

A) an experimental artifact
B) a photon rocket

You can use the whole data (including the outlier) if you like to make the argument.   For the photon rocket argument I don't understand how the photons get out of the EM Drive and how does it get to do better than a perfect photon rocket.

Can you make an experimental artifact argument?
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 06:15 pm
...
This is quite good except Shawyer's results : should we skip those two outliers ?  :D
 
.....

What statistical argument can you use to state that those two are outliers?
It was a sarcastical argument, not a statistical argument. I'm not seriously considering to lower the data count to 4 samples.
OK, but I wear my humorous hat only with Kernosabe  :)

But seriously, that Brady (b) is a statistical outlier on the basis of its deviation from the statistical cluster formed by the data without it.
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 06:30 pm
Quote
I think that the only length that is relevant is the length of the truncated cone itself and not the length of the cylinder attached to it, so "Length" means Length of truncated cone

I don't know. I speculate that knowing the big diameter, we might be able to back the small diameter out of Shawyer's performance model using his published data. He does say that the thrust agrees with his performance model and it does use diameters of the ends of the cavity.

Do you agree that there is a cylindrical section to Shawyer's Demonstrator EM Drive that has the same diameter throughout? and that the diameter of this cylindrical section is the same as the diameter of the small base of the truncated cone? And therefore the smaller diameter at the end of the cavity is the same as the diameter of the small base of the truncated cone?

Did I miss something ?

If my logic above is not faulty, then our large discrepancy (a factor 2 between us ) is a matter of measurement and scaling.
One of us must be closest to the real answer ...

(http://emdrive.com/images/emdrive.jpg)
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 07:27 pm
Another explanation for the EM Drive experimental findings based on a theory that allows electromagnetic fields to modify the space-time metric of General Relativity:

http://inspirehep.net/record/1220790/files/arXiv%3A1302.5690.pdf

http://arxiv.org/pdf/1310.5029.pdf

"Some axisymmetric electromagnetic modes of a truncated conical cavity are then presented
and used as source in the weak-field approximation of the equations, previously obtained,
to determine the force on the cavity. It is found that a coupling of the same magnitude
as used in [5] between the scalar  and the electromagnetic field results in a correct
magnitude and sign for the forces reported in asymmetric resonant cavities. ...The theory, however, does not seem to be completely satisfactory because in its linearized version it also predicts strong gravitational effects
by the Earth’s magnetic field, which are clearly not observed. A possible resolution of
this problem is considered in the last section."

"It was shown that the weak field approximation of a rather general scalar-tensor theory of
gravity, which includes an additional scalar with strong coupling to the electromagnetic
field, as proposed in[5], could account for the forces reported on asymmetric resonant
cavities. Although highly speculative, it is interesting that this was done using the
same coupling coefficient adjusted by[5] to explain discordant measurements of Newton
gravitational constant. It is also of interest that the inclusion of the external scalar 
can help to reconcile the Solar System tests with values of the Brans-Dicke parameter
close to unity (see relation (15)). The weakest part of the theory seems to be that
there is no clear way of preventing large gravitational effects due to the magnetic field
of the Earth, as predicted by Eq. (17). A possible solution can be sought in non-linear
effects,...Note that if this is possible for a static magnetic field, it could possibly not be the
case for a static electric field outside its sources, because the difference of sign would not allow real solutions.
It is so expected that static magnetic and electric fields show no unusual
gravitational effects, while non-stationary electromagnetic fields do. "


Title: Re: EM Drive Developments
Post by: aero on 10/17/2014 07:43 pm
Quote
I think that the only length that is relevant is the length of the truncated cone itself and not the length of the cylinder attached to it, so "Length" means Length of truncated cone

I don't know. I speculate that knowing the big diameter, we might be able to back the small diameter out of Shawyer's performance model using his published data. He does say that the thrust agrees with his performance model and it does use diameters of the ends of the cavity.

Do you agree that there is a cylindrical section to Shawyer's Demonstrator EM Drive that has the same diameter throughout? and that the diameter of this cylindrical section is the same as the diameter of the small base of the truncated cone? And therefore the smaller diameter at the end of the cavity is the same as the diameter of the small base of the truncated cone?

Did I miss something ?

If my logic above is not faulty, then our large discrepancy (a factor 2 between us and a factor of 4 between my estimate and McCulloch's estimate) is a matter of measurement and scaling.  Of the photograph you and I are using is not the Demonstrator Drive, and Prof. McCulloch has better information as to what the dimensions of the Demonstrator Drive are?

One of us must be closest to the real answer ...

(http://emdrive.com/images/emdrive.jpg)

I don't know. I did post asking Prof M if he had better information. I also emailed Shawyer and Juan's university asking the same question. We will see if anyone responds.

I had assumed that the tapered cavity extended within the cylindrical section but you may be right. However, as was pointed out by Notsosureofit, it looks like there is some sort of mechanism in the cylindrical section. If there is a moveable small end, then I can't guess what the interior of the cylinder looks like.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/17/2014 07:53 pm
The upper gizmo is the motor and at the bottom it's driving a variable resistor as position feedback.  It probably was fed w/ a fixed frequency generator.
Hanging out the back is prob a limit switch.
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 07:57 pm
....
I don't know. I did post asking Prof M if he had better information. I also emailed Shawyer and Juan's university asking the same question. We will see if anyone responds.

I had assumed that the tapered cavity extended within the cylindrical section but you may be right. However, as was pointed out by Notsosureofit, it looks like there is some sort of mechanism in the cylindrical section. If there is a moveable small end, then I can't guess what the interior of the cylinder looks like.
Prof. McCulloch has answered that "I think I estimated 4cm using the design factor, probably wrongly. Your photographic method is better"

So it is up to us now to decide.  Can you please double check your diameter estimate? I double checked mine and it is 2 times your estimate for the small base of the Demonstrator
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/17/2014 08:11 pm
For the O.D. of the copper straight section I get 18.8 cm if that helps  (using the pot as ref)

15.3 cm using the RF connector, but not sure of the right connector and worse camera angle,  sooo ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 08:14 pm
For the O.D. of the copper straight section I get 18.8 cm if that helps  (using the pot as ref)

Can you also please estimate the OD of the big diameter base end?

(Using your same method)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/17/2014 08:28 pm
For the O.D. of the copper straight section I get 18.8 cm if that helps  (using the pot as ref)

Can you also please estimate the OD of the big diameter base end?

(Using your same method)

29.6 cm for the pot
24.1 cm for the connector
still might have some camera distortion in that picture

(of course I'm comparing to parts I have here)
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/17/2014 08:46 pm
Another explanation for the EM Drive experimental findings based on a theory that allows electromagnetic fields to modify the space-time metric of General Relativity:

http://inspirehep.net/record/1220790/files/arXiv%3A1302.5690.pdf

http://arxiv.org/pdf/1310.5029.pdf

The proposed experiment looks exceptionally simple. Has this experiment been conducted? If there were positive results, the fringe forums would be ablaze with excitement over the possibilities.

I suspect that an experiment may have already been performed in the ten months since the paper was published, but due to the unpopularity of null results in scientific publishing, the results haven't made it very far.
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 08:57 pm
Another explanation for the EM Drive experimental findings based on a theory that allows electromagnetic fields to modify the space-time metric of General Relativity:

http://inspirehep.net/record/1220790/files/arXiv%3A1302.5690.pdf

http://arxiv.org/pdf/1310.5029.pdf

The proposed experiment looks exceptionally simple. Has this experiment been conducted? If there were positive results, the fringe forums would be ablaze with excitement over the possibilities.

Don't know, but I agree that the experiment is simple and if it would be positive we should have heard about it.

Also, if one is going to posit an interaction of the EM Drive magnetic field, the first interaction one should explore is the interaction between the microwave cavity's magnetic field with the Earth's magnetic field.  This should be proportional to the Power Input.  One could also posit PowerInput*Q.  What I haven't determined is magnetic interaction with the Earth's field producing the required magnitude of forces, the direction, and the dependence on the diameters of the bases.  Waiting for frobnicat to help me with that...
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 09:03 pm
For the Shawyer Demonstrator Thruster, using the picture at the bottom of the page here: http://emdrive.com/

(http://emdrive.com/images/emdrive.jpg)



aero

Large Base Diameter =28 cm
Small Base Diameter =7.78 cm
Length = 38.1 cm (including both the truncated cone plus the straight cylinder)


NotSoSureOfIt Pot-Based

Large Base Diameter = 29.6 cm
Small Base Diameter = 18.8 cm


NotSoSureOfIt RFConnector-Based

Large Base Diameter =24.1 cm
Small Base Diameter =15.3 cm



Rodal

Large Base Diameter = 28 cm
Small Base Diameter = 15.9 cm
Length = 22.6 cm  (including only the truncated cone)



Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/17/2014 09:45 pm
If there is a moveable small end, then I can't guess what the interior of the cylinder looks like.

Compressed hummingbird wings, guys.

Y'all have no idea what's inside the device!

For the O.D. of the copper straight section I get 18.8 cm if that helps  (using the pot as ref)

15.3 cm using the RF connector, but not sure of the right connector and worse camera angle,  sooo ?

I offer to try my hand at dimensional analysis.  What is being used as the basis for the dimensional extrapolations you guys have come up with?

I would start with the nut diameter.  These are likely to be standard, and unlikely to be guessed at wrongly by a factor of two.
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 09:54 pm
For the O.D. of the copper straight section I get 18.8 cm if that helps  (using the pot as ref)

15.3 cm using the RF connector, but not sure of the right connector and worse camera angle,  sooo ?

I offer to try my hand at dimensional analysis.  What is being used as the basis for the dimensional extrapolations you guys have come up with?

I would start with the nut diameter.  These are likely to be standard, and unlikely to be guessed at wrongly by a factor of two.
I calculated as follows:

Ratio = (SmallDiameterMeasuredwithCaliperOnScreen)/(LargeDiameterMeasuredwithCaliperOnScreen)

LargeDiameter = 28 cm [known data from Shawyer's report]

RodalEstimateOfSmallDiameter = Ratio * 28 cm

Hence no nuts were used, and no nuts were hurt for my analysis.

Now, is that nuts ?

https://www.youtube.com/watch?v=zbFSYtv-i3c



For greater accuracy I can feed the image to Mathematica and perform a digital analysis, but at this stage is not required.

The two estimates from NotSoSureOfIt are close to mine.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/17/2014 09:59 pm
Can I congratulate all on the thread for make it one of the most posted and viewed on NSF.
Of course all this stuff is insanely interesting and if it can be developed then we are in sci-fi land :)
I had things to say early on in this thread but I have to stand back now and read the analysis...
Thank you guys. This is my fave thread on NSF!
Prof. McC. Please help us! I think your theory is true. Application to propulsion?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/17/2014 10:12 pm
...
Waiting for adjusted inputs...
We still would like to hear whether there is an argument that can be made, explaining the formulas that model the experimental results either as:

A) an experimental artifact
B) a photon rocket

You can use the whole data (including the outlier) if you like to make the argument.   For the photon rocket argument I don't understand how the photons get out of the EM Drive and how does it get to do better than a perfect photon rocket.

Can you make an experimental artifact argument?

Me ? Not really.

Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field and/or local field (damping system) and/or local ferromagnetic chamber walls. Those are words so this is not an argument yet. Please don't argue, yet.

But if anyone wants to help me putting up this argument (and then argue) :
for this argument I would need to know if there is a possibility of non linearities around 0 of conductivity in skin of cavity for strong RF fields. Even one part per thousand could be interesting. A small asymmetry in hysteresis for instance. Asking Mulletron and a few search of the available literature didn't float anything like that, at least for metal conductors (rather into semiconductors with more or less exotic composition, not plain copper). Or for dielectrics but I guess they don't have DC conduction to speak of. I don't know if it is because there is no such effect at all in conductors, or because this effect is generally ignored, or because it would be a complex special case of dielectric (non linear) very close conductor (eddy currents). How tight the dielectrics are encased in copper ? Also I would need to understand the geometry of eddy currents, and my EM course is long ago and wasn't specifically on microwave cavities or skin effects. So I'm a bit disarmed.

Can we do summary, for the seven data points, of qualitative boolean or discrete values like
1/ vacuum ?
2/ magnetic damping ?
3/ ferromagnetic walls nearby (vacuum chamber or else) ?
4/ offboard generator ?
5/ inverted pendulum or torsion balance ?
6/ thermal isolation casing ?
7/ ... ?

at least for all such boolean or discrete values for which we have values or likely guess for most of the data points ?

Could we also throw in the negative results while we are at it : Brady without dielectric, Brito/Marini/Galian without magnetic damping, what else ?

Maybe we could then see some patterns, some already discussed, maybe some others ...
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 10:31 pm
...
Waiting for adjusted inputs...
We still would like to hear whether there is an argument that can be made, explaining the formulas that model the experimental results either as:

A) an experimental artifact
B) a photon rocket

You can use the whole data (including the outlier) if you like to make the argument.   For the photon rocket argument I don't understand how the photons get out of the EM Drive and how does it get to do better than a perfect photon rocket.

Can you make an experimental artifact argument?

Me ? Not really.

Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field and/or local field (damping system) and/or local ferromagnetic chamber walls. Those are words so this is not an argument yet. Please don't argue, yet.

But if anyone wants to help me putting up this argument (and then argue) :
for this argument I would need to know if there is a possibility of non linearities around 0 of conductivity in skin of cavity for strong RF fields. Even one part per thousand could be interesting. A small asymmetry in hysteresis for instance. Asking Mulletron and a few search of the available literature didn't float anything like that, at least for metal conductors (rather into semiconductors with more or less exotic composition, not plain copper). Or for dielectrics but I guess they don't have DC conduction to speak of. I don't know if it is because there is no such effect at all in conductors, or because this effect is generally ignored, or because it would be a complex special case of dielectric (non linear) very close conductor (eddy currents). How tight the dielectrics are encased in copper ? Also I would need to understand the geometry of eddy currents, and my EM course is long ago and wasn't specifically on microwave cavities or skin effects. So I'm a bit disarmed.

Can we do summary, for the seven data points, of qualitative boolean or discrete values like
1/ vacuum ?
2/ magnetic damping ?
3/ ferromagnetic walls nearby (vacuum chamber or else) ?
4/ offboard generator ?
5/ inverted pendulum or torsion balance ?
6/ thermal isolation casing ?
7/ ... ?

at least for all such boolean or discrete values for which we have values or likely guess for most of the data points ?

Could we also throw in the negative results while we are at it : Brady without dielectric,
Brito/Marini/Galian without magnetic damping, what else ?

Maybe we could then see some patterns, some already discussed, maybe some others ...

Eliminate 5/ inverted pendulum or torsion balance ?
I did a fully coupled nonlinear analysis and the problem cannot be explained solely on that basis.
What it can do is to magnify another effect.

Concerning:  <<Could we also throw in the negative results while we are at it : Brady without dielectric>>

No, that is not a relevant result, did you have a chance to look at my posts regarding that? Conducted first in the their testing program, at a completely different frequency, way off the scale to the right on their S22 chart and their COMSOL Finite Element predictions.  I don't think it has anything to do with the dielectric.  At that frequency they didn't report any force measurements whatsoever (with or without).  Basically they were flying blind, they did that experiment at a different frequency, they did not report any Q at that frequency, and from the S22 plot it is likely there was no resonance at that frequency

Concerning <<Brito/Marini/Galian>>

Not relevant to microwave cavities.  Not relevant to Shawyer, China or NASA Eagleworks experiments. Only relevant to Woodward/March MET.

Concerning <<6/ thermal isolation casing ?>>

What is that? Please elaborate
Title: Re: EM Drive Developments
Post by: frobnicat on 10/17/2014 10:33 pm
The upper gizmo is the motor and at the bottom it's driving a variable resistor as position feedback.  It probably was fed w/ a fixed frequency generator.
Hanging out the back is prob a limit switch.

Shawyer's demonstrator : isn't it possible that it's a thread driving a plate in longitudinal position inside the cylinder, that is an adjustable length cavity ? Is that what you mean by "fed with a fixed frequency" : the cavity is adjusted to fit the frequency and not the inverse ? Isn't all that documented by Shawyer ? Or is it in NDA ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 10:39 pm
....
Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field ...

Interaction with the Earth's magnetic field is also first in my list of experimental artifacts.

Why would an interaction with the Earths' magnetic field be oriented along the cone axis and would favor a larger difference between the diameters of the bases of the truncated cone?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/17/2014 10:40 pm
The upper gizmo is the motor and at the bottom it's driving a variable resistor as position feedback.  It probably was fed w/ a fixed frequency generator.
Hanging out the back is prob a limit switch.

Shawyer's demonstrator : isn't it possible that it's a thread driving a plate in longitudinal position inside the cylinder, that is an adjustable length cavity ? Is that what you mean by "fed with a fixed frequency" : the cavity is adjusted to fit the frequency and not the inverse ? Isn't all that documented by Shawyer ? Or is it in NDA ?
If you have an adjustable cavity that allows you to tune it. However if your microwave source is not stable then you are are screwed. cf Rodal and his mate saying that RF emitters with a variance of < 1Hz are available but not used in the current experiments.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/17/2014 10:56 pm
Eliminate 5/ inverted pendulum or torsion balance ?
I did a fully coupled nonlinear analysis and the problem cannot be explained solely on that basis.
What it can do is to magnify another effect.
ok

Quote
Concerning:  <<Could we also throw in the negative results while we are at it : Brady without dielectric>>

No, that is not a relevant result, did you have a chance to look at my posts regarding that? Conducted first in the their testing program, at a completely different frequency, way off the scale to the right on their S22 chart and their COMSOL Finite Element predictions.  I don't think it has anything to do with the dielectric.  At that frequency they didn't report any force measurements whatsoever (with or without).  Basically they were flying blind, they did that experiment at a different frequency, they did not report any Q at that frequency, and from the S22 plot it is likely there was no resonance at that frequency
I concede I might not have the chance to look more than briefly at your posts concerning that. Are we to think that "dielectric vs no_dielectric" is to be considered irrelevant, or that "all relevant results used dielectric" ? Then we have a boolean column full of yes. That is an information by itself.

Quote
Concerning <<Brito/Marini/Galian>>

Not relevant to microwave cavities.  Not relevant to Shawyer, China or NASA Eagleworks experiments. Only relevant to Woodward/March MET.
Yeah alright, I forgot we had two different approaches to deal with.

Quote
Concerning <<6/ thermal isolation casing ?>>

What is that? Please elaborate
Well as I understood Brito et all negative results, they used a phase changing thing around their system to have thermal isolation during the runs. Was that it, should I read again? But since this experiment is not relevant, discard this criteria (I guess nobody else doing microwave cavities have been through that trouble, so this is a boolean column full of no).

What I'm most interested in, at the moment for making an argument, is if the boolean column (2/ permanent local magnetic field OR 3/ nearby ferromagnetic mass) is full of yes.
Title: Re: EM Drive Developments
Post by: aero on 10/17/2014 10:59 pm

Another way to get at the length of the cavity is to look at the half wavelength multiples for resonance. But the wavelength is so short that it is not very helpful. Knowing the length and the wall taper (=.53) will give the small end diameter. I assume that the cone extends inside the cylinder some unknown distance.

lamda   n   2d=n*Lamda    d, m
0.12236   1   0.122364269    0.0612
0.12236   2   0.244728537    0.1224
0.12236   3   0.367092806    0.1835
0.12236   4   0.489457074    0.2447
0.12236   5   0.611821343    0.3059
0.12236   6   0.734185611    0.3671
0.12236   7   0.85654988    0.4283

I think we've had guesses for all of those values of n, except perhaps n=4. But maybe n = 3, as it does for Brady's device.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/17/2014 11:22 pm
....
Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field ...

Interaction with the Earth's magnetic field is also first in my list of experimental artifacts.

Why would an interaction with the Earths' magnetic field be oriented along the cone axis and would favor a larger difference between the diameters of the bases of the truncated cone?

Good questions.
Can earth magnetic field account for the order of magnitude of results ? This I could help to address with rough estimates. The direction, axis and magnitude dependence on geometry, I have no precise idea right now and am unsure I could contribute. Thinking about it (part time).
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 11:29 pm
For the Shawyer Demonstrator Thruster, using the picture at the bottom of the page here: http://emdrive.com/

(http://emdrive.com/images/emdrive.jpg)



aero (updated based on pixels)

Large Base Diameter =28 cm
Small Base Diameter =16.7 cm
Length = 21.0 cm  (including only the truncated cone)
Slope of Cone = ((28 - 16.7)/2)/21.0 = 0.2690


NotSoSureOfIt Pot-Based

Large Base Diameter =  28 cm
Small Base Diameter = (18.8 cm/29.6 cm)*28 cm = 17.78 cm



NotSoSureOfIt RFConnector-Based

Large Base Diameter = 28 cm
Small Base Diameter =(15.3 cm / 24.1 cm) * 28 cm =  17.78 cm



Rodal

Large Base Diameter = 28 cm
Small Base Diameter = 15.9 cm
Length = 22.6 cm  (including only the truncated cone)
Slope of Cone = ((28 - 15.9)/2)/22.6 = 0.2677




Average

Large Base Diameter = 28 cm
Small Base Diameter = 16.79 cm
Length = 20.89 cm



Median = @aero

Large Base Diameter = 28 cm
Small Base Diameter =16.7 cm
Length = 21.05 cm


Notes:

Average and median lengths calculated based on average of cone slopes (0.2683) calculated by aero and Rodal, and the average and median diameters respectively. For example (28.00-16.79)/(2* 0.2683) = 20.89

I adjusted notsosureofit's estimates for the large diameter to be Shawyer's published value (28 cm) and the small diameter accordingly as shown.

Range = 17.78 cm -  15.9 cm  = 1.88 cm
HalfRange/Average = 5.60%  (not bad  :)   )
(Average-Median)/Average: 0.5% (pretty symmetric  :)   )
(ratio of slopes calculated by aero & Rodal) - 1 = 0.2690/ 0.2677 - 1= 0.49% (very close  :)  )
Also, three different independent measurements:
aero: pixels
notsosureofit: pot and RFconnector
rodal: caliper
Title: Re: EM Drive Developments
Post by: Rodal on 10/17/2014 11:37 pm
....
Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field ...

Interaction with the Earth's magnetic field is also first in my list of experimental artifacts.

Why would an interaction with the Earths' magnetic field be oriented along the cone axis and would favor a larger difference between the diameters of the bases of the truncated cone?

Good questions.
Can earth magnetic field account for the order of magnitude of results ? This I could help to address with rough estimates. The direction, axis and magnitude dependence on geometry, I have no precise idea right now and am unsure I could contribute. Thinking about it (part time).
I'm not too concerned with the order of magnitude at this point in time because the inverted torsional pendulum can amplify whatever effect is thrusting the device  (maybe even dark matter  :o).  I would think that the main thing to do is to find a classical experimental artifact that also acts along the axis of the cone, that depends on orientation of the big base and that it is larger with increasing difference between the base diameters.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/18/2014 12:50 am
....
Right now my bet would be something in the line of induced DC component interacting magnetically with either earth magnetic field ...

Interaction with the Earth's magnetic field is also first in my list of experimental artifacts.

Why would an interaction with the Earths' magnetic field be oriented along the cone axis and would favor a larger difference between the diameters of the bases of the truncated cone?

Good questions.
Can earth magnetic field account for the order of magnitude of results ? This I could help to address with rough estimates. The direction, axis and magnitude dependence on geometry, I have no precise idea right now and am unsure I could contribute. Thinking about it (part time).
I'm not too concerned with the order of magnitude at this point in time because the inverted torsional pendulum can amplify whatever effect is thrusting the device  (maybe even dark matter  :o).  I would think that the main thing to do is to find a classical experimental artifact that also acts along the axis of the cone, that depends on orientation of the big base and that it is larger with increasing difference between the base diameters.

So, this makes the "inverted torsional pendulum" criteria relevant somehow, sorry to ask because of poor memory and shallow reading : do all the relevant experiments done with this apparatus ?

If I'm going through this very cavalier and maybe senseless calculation from Brady a :
around 20W power, around 0.2m linear sizes, around 2µm skin depth for most eddy currents
earth magnetic field (http://en.wikipedia.org/wiki/Earth%27s_magnetic_field), say B=50µT
copper resistivity rho is approx. 1.7e-8 Ohm m (http://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Resistivity_and_conductivity_of_various_materials)
lets say a conductive strip of copper around .8m length .2m large 2µm thick.
has a resistance of R = rho length / (large thick) = 0.034 Ohm
that's a good conductor
To get a dissipation of 20W the current (RMS) would be (from P=RI²)  I=sqrt(P/R)=24A
This is not a DC current, but if it were, a DC current like that on l=.2m forward part .2m backward part (normal to B field), rad=.1m around a centre of rotation, would amount to a force of B l I on each branch, and that is a torque of 2 B l I rad =  5e-5 Nm  (give or take).
I think (but I'll think again) that a current loop in a locally homogeneous B field can't generate thrust, only torque. But when mounted on an arm at distance d around a pivot, something that undergo an imposed torque will transmit the torque that could appear as a tangential thrust of torque/d (please comment on that one, correct ?). I don't know if we could understand "inverted torsional pendulum" as equivalent to "arm on pivot", guess not, but if we could, with d=0.5m, that would look like a thrust of torque/d = 100µN
Brady a reports 90µN

Note the (most) silly hypothesis in bold.

Now, basically, if we have a local B field 1000 times that of earth because of strong permanent magnet in the vicinity (around 50mT), and there is an acdc_ratio of 1 part per 1000 AC -> DC asymmetry in conduction (welcome back to the weak rectifier hypothesis) then magnitude could be up to the job. Also a ferromagnetic wall nearby could serve to couple with 20mA DC but don't know how to estimate that.

If the instabilities of inverted torsional pendulum make it so that  a torque of (acdc_ratio times 50µNm) can explain things, so well, but the problem is that acdc_ratio is probably very small, or 0.

Must sleep now. Evening at the cinema to see Jean-Luc Godard's latest movie in 3D, Adieu au langage, exhausting.
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 12:54 am
OK, we reached agreement on Shawyer's big rig.

Now we (aero and hopefully notsosureofit and hopefully JohnFornaro) can work on the small drive.

aero ==> take a look at the PM I sent you the slope

I'll continue tomorrow, but this is the last I had on that:

For the Experimental Thruster, using Fig. 6 of Shawyer's report (http://www.emdrive.com/IAC-08-C4-4-7.pdf) I get:

Large Base Diameter = 16 cm = 0.16 m
Small Base Diameter = 11 cm = 0.11 m  (+41% greater than @aero's estimate)
Length = 15.8 cm = 0.158 m (-11% less than @aero's estimate)
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/18/2014 01:26 am
From the 1st of the two papers linked to earlier (electromagnetic fields modifying special relativity) -

Quote
There are no details in the literature as to the precise dimensions of the cavities used in the experiments, so that an example roughly similar to the overall dimension reported and with the proportions observed in the published photographs will be used. Assuming a wall of thickness 1 mm, and a copper mass density of 8.9×103 kg/m3, we have σ = 8.9kg/m2.

We further consider the copper cavity to have r1 = 18 cm, r2 = 36 cm, and θ0 = 22◦. For this cavity, the lowest TM mode corresponds to the order n = 5.75632 of the Legendre polynomial, with a resonant frequency ν = 1.05GHz. For a resistivity η = 1.72×10−8 Ωm the quality factor for this mode is Qcav = 3.13×104. The next two TM modes have the same order n = 5.75632, and resonant frequencies ν = 2.05GHz
11 and ν = 2.76GHz, with quality factors Qcav = 3.11 × 104 and Qcav = 5.24 × 104, respectively.

What Minotti used for his calculations.
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 01:28 am
My estimate is that applying these geometric corrections
( http://forum.nasaspaceflight.com/index.php?topic=29276.msg1272692#msg1272692   )
to Shawyer's and China's experiments, and using McCulloch's formula now leads to appreciable underprediction of their experimental forces.

I very much congratulate aero for finding this signiificant error:  the small diameter of the Shawyer EM Drive was actually 4 times larger (16 cm instead of 4 cm).

We are going to need to explore the other formulas as well as aero's proposal for using the Unruh wavelength in McCulloch's formula, but first we have to come to an agreement on what is the slope of  a cone. (aero uses the word taper instead, and to communicate well we need to understand each other's definitions).

The slope of a truncated cone is

slope= (BigRadius - SmallRadius)/Length = (BigDiameter - SmallDiameter)/(2*Length)

and therefore it is 1/2 of what aero calls taper. Where the slope = Tangent[angle], therefore the angle (in radians) is ArcTan[slope]

For Shawyer's Demo Drive, the slope is 0.268 (instead of 0.53). 

The cone angle for Shawyer's Demo Drive is ArcTan[0.268] = 15 degrees = 0.262 radians
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/18/2014 01:49 am
Couple things:
Won't get back to the lab til monday for measurements from picture
Both end plates have something else going on.  Looks likr the top one has a tuning plate(?) of some kind, not motorized
Why the extra plate below the bottom, can't see in pic

Found another paper that was bothering me in the piles behind the desk
"Ionization instabilities and resonant acoustic modes", Physics of Plasmas, V8, N0.11, p.5018

It was concerned w/ the coupling of ions w/ dust particles.  Reminds me of RF w/ axions  (Ya, I'm still chasing the axion connection) no cavities involved, but "It is found that an unstable dust-acoustic mode of nonzero real frequency can be generated via a resonance phenomenon."  ... "As the charge on dust particles exceeds a threshold, multiple low-frequency modes with large growth rates are excited suddenly."

I just had to throw that in cuz I finally found the d**m thing !  (You youngsters can play w/ it for now)

Ok, so in practical terms it means you can (theoretically)induce feedback into the coupling constant if you can set up the dispersion relations properly.



Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/18/2014 02:26 am
FWIW:

I converted the JPEG to a 8 bit gray TIF; imported into AutoCAD R14; scaled it so the big end was 28 cm.  To an arbitrary level of accuracy, since these are old eyeballs.:

1st Flange to 2nd flange:  3.0214284 cm
2nd flange to Cylinder 16.59242861 cm
Cylinder: 13.5771431 cm

Diameter of big end: 28 cm
Diameter of cylinder: 17.2052288 cm

Nuts to you all.
Title: Re: EM Drive Developments
Post by: aero on 10/18/2014 02:28 am
Using the photo of Shawyer's Experimental thruster from the PDF document with screen zoom to fit, and using a pixel measurement tool, I measured the big diameter = 759 pixels, small diameter = 496 pixels, and length = 725 pixels. From the PDF document the cavity diameter is given as 160 cm. Using this, I converted to meters as follows:
w_big = 759 pixels = 0.160 meters
w_small= 496 pixels = 0.105 meters
length = 725 pixels = 0.153 meters

I very deliberately chose my corner points where I thought they were. Others will very deliberately choose corner points where they think they are. Our measurements will differ because our corner points will differ. That is OK because we are trying to reach a consensus.

There is of course the question of just what Shawyer referred to in his paper when he wrote that the diameter was 160 mm. Which diameter, inside, outside, outside the supporting ring?

Oh well, the best we can do is the best we can do, and it will be good enough. (We all hope)  :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 02:43 am
FWIW:

I converted the JPEG to a 8 bit gray TIF; imported into AutoCAD R14; scaled it so the big end was 28 cm.  To an arbitrary level of accuracy, since these are old eyeballs.:

1st Flange to 2nd flange:  3.0214284 cm
2nd flange to Cylinder 16.59242861 cm
Cylinder: 13.5771431 cm

Diameter of big end: 28 cm
Diameter of cylinder: 17.2052288 cm

Nuts to you all.

Thanks kernosabe.  You raised this to a new level with AutoCAD.






Great job.

Now, can you do the same for the small Shawyer drive (    http://forum.nasaspaceflight.com/index.php?topic=29276.msg1272736#msg1272736   )?



Only read this if you feel like double checking...what is the meaning of big end

Is big end the biggest possible end or you make a difference between big end and biggest end ?

not clear as to whether big end for you is the biggest end or just the big end short of the biggest one

https://www.youtube.com/watch?v=0zNCXyTfulo

not clear on whether you count first flange from the right or from the left

not clear as to whether you call big end the one at the 4th flange or the one at the 3rd flange starting from the left



me think you did it right, but just in case... :)

Title: Re: EM Drive Developments
Post by: aero on 10/18/2014 03:12 am
why don't you just draw a picture of it and put dimension on it :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 03:29 am
Yes, it would help if you can attach a file that people without AutoCad can open.  I tried to open your dxf file with Mathematica and this is what I got:
Title: Re: EM Drive Developments
Post by: aero on 10/18/2014 06:02 am
@Rodel

Slope and taper are not the same. Slope = taper/2 . Both are related to the half angle of the cone by the inverse sine function. For me, it is much easier and more accurate to measure the taper of the cone from the photograph.

Select 2 axially separated points on the cone, measure the diameter at those two points and the axial distance between them. The taper is the positive difference of the two diameters divided by the axial distance between them. The diameter at any axial distance x from the larger diameter (d-large) in the direction of the smaller diameter is then
dia. = d-large - x * taper, or if you measure x from the small diameter (d-small) in the direction of the larger diameter,
dia. = d-small + x * taper

So taper is the rate of change of diameter with distance.

Or it could be a long, skinny candle!

I hope we're done with this now.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 09:07 am


"Still struggling to see how the momentum conservation would propagate to rest of cosmos in some "photon Unruh" generated perturbation, like pushing on the walls of its own universe or pushing on one's own acceleration. Surely this costs some energy, how can this energy be less than   c*acquired_momentum   or else borrowed from some potential, that is, communicated to the outside ?"

Yes, I agree. As I have said, a HUGE "I Believe Button" was pressed on this assumption. I provided data to show how how conservation of momentum inside the unit doesn't amount to a conservation outside.

The unit still must experience a force from outside in order to move.

http://gr.physics.ncsu.edu/files/babson_ajp_77_826_09.pdf page 2
http://arxiv.org/ftp/arxiv/papers/1012/1012.5264.pdf  page 2

It isn't enough to just say that momentum was conserved and therefore it just moves, because it just does. That ignores hundreds of years of established science.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/18/2014 09:10 am


"Still struggling to see how the momentum conservation would propagate to rest of cosmos in some "photon Unruh" generated perturbation, like pushing on the walls of its own universe or pushing on one's own acceleration. Surely this costs some energy, how can this energy be less than   c*acquired_momentum   or else borrowed from some potential, that is, communicated to the outside ?"

Yes, I agree. As I have said, a HUGE "I Believe Button" was pressed on this assumption. I provided data to show how how conservation of momentum inside the unit doesn't amount to a conservation outside.

The unit still must experience a force from outside in order to move.

http://gr.physics.ncsu.edu/files/babson_ajp_77_826_09.pdf page 2
http://arxiv.org/ftp/arxiv/papers/1012/1012.5264.pdf  page 2

It isn't enough to just say that momentum was conserved and therefore it just moves, because it just does. That ignores hundreds of years of established science.
Mach's principle?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 10:31 am
Well I've been busy as heck over the last few days getting ready for a board. Some observations I have are:

The "statistical outlier," (circled in green) given the small sample size, I don't think we can do a statistical analysis on this, but the data is very telling nonetheless....

Given the shape of a TM211 cell within a conical cavity, one can easily see where resonant operation of the cavity is very dependent on a very small frequency bandwidth. A small change in frequency changes the mode shape, thus changing the RF field's interaction with the dielectric. Apart from my drawing ability, the attachment is intended to give you a rough idea how frequency changes the mode cells in TM211. I don't have access to COMSOL to actually see exactly what the difference is.

It is clear that thrust is not solely a function of scaling with Q. The mode shape is more important than Q.
I'm not alone here:
http://nextbigfuture.com/2014/08/full-nasa-cannae-drive-and-emdrive-test.html

My previous comments:
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1268788#msg1268788

I really need more data. The conclusion of the NASA paper (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf) mentions future use of higher k dielectric materials, vice PE/PTFE. Page 21 "This resonator material has a relative permittivity that is an order of magnitude higher than our current tapered cavity test article resonator material." I'd love to know what this material is. Even my idea of using PVDF (rp between 8-12) is not an order of magnitude higher than the 2.1-2.25 rp of PE/PTFE.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 11:39 am
http://vixra.org/pdf/1410.0067v1.pdf

Another theory of how EMdrive works.

This paper is neat and all (this guy melted my brain at the bottom of page 2, see gravity), but it once again ignores the experimental finding that:

Nasa report page 18:
"There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber."

Interesting reading nonetheless. He put some pretty big wings on dem pigs.

I'm a firm believer that we don't need to rewrite physics in order to find an explanation for EMdrive, even if you happen to slap some polish on GR (MiHsC) along the way.

There isn't much modification to inertia that can be done here on good ol planet Earth.

What's left are experimental artifacts (heat, EM leakage, etc) and the cause for anomalous thrust. NASA seems to think that anomalous thrust is inextricably linked to the dielectric.
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 12:50 pm

Another way to get at the length of the cavity is to look at the half wavelength multiples for resonance. But the wavelength is so short that it is not very helpful. Knowing the length and the wall taper (=.53) will give the small end diameter. I assume that the cone extends inside the cylinder some unknown distance.

lamda   n   2d=n*Lamda    d, m
0.12236   1   0.122364269    0.0612
0.12236   2   0.244728537    0.1224
0.12236   3   0.367092806    0.1835
0.12236   4   0.489457074    0.2447
0.12236   5   0.611821343    0.3059
0.12236   6   0.734185611    0.3671
0.12236   7   0.85654988    0.4283

I think we've had guesses for all of those values of n, except perhaps n=4. But maybe n = 3, as it does for Brady's device.

wavelength = c / frequency

For both the experimental and demonstrator drives of Shawyer

frequency = 2.45 GHz

therefore the microwave wavelength for both the experimental and the demonstrator Shawyer drives is:

wavelength = 299792458 (m/s) / 2.45*10^9 (1/s)
                  = 0.12236 m


The dimensions of Shawyer's demonstrator drive (from http://forum.nasaspaceflight.com/index.php?topic=29276.msg1272692#msg1272692 ) are:

Large Base Diameter = 0.28 m
Small Base Diameter = 0.1679 m
LengthOfCone = 0.2089 m
LengthOfCylinder=0.13577 m

2*Large Base Diameter / wavelength =  4.58
2*Small Base Diameter / wavelength =  2.74
2*LengthOfCone / wavelength =  3.42
2*(LengthOfCone+LengthOfCylinder) / wavelength =  5.64
2*(LengthOfCone+(1/2)*(LengthOfCylinder)) / wavelength = 4.52



Force =(   PowerInput*Q / (c/wavelength)  )*(1/SmallDiameter-1/LargeDiameter)

experimental and demonstrator frequency = 2.45 GHz

c / 2*LengthOfCone  = 0.718 GHz
c / 2*(LengthOfCone+LengthOfCylinder)= 0.435 GHz
c /2* (LengthOfCone+(1/2)*(LengthOfCylinder))= 0.542 GHz
c / 2*(2*0.12236 m)= 0.613 GHz

==> For Shawyer's Demonstrator drive the "frequency" in McCulloch's calculation should be c / 2*(2*0.12236 m)= 0.613 GHz instead of 2.45 GHz, therefore the predicted force value should be 2.45/0.613 = 4 times greater based on the actual wavelength.  Based on the cavity length, the predicted force should be ~ 2.45/1.083 = 4.52 times greater



EDIT: Thanks to aero for catching an error I made missing the factor of 2
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/18/2014 12:56 pm
Well I've been busy as heck over the last few days getting ready for a board.

2x4?  2x6?  2x8?

C'mon man.  Without numbers, this is just gibberish.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 01:17 pm
Well I've been busy as heck over the last few days getting ready for a board.

2x4?  2x6?  2x8?

C'mon man.  Without numbers, this is just gibberish.

8, 12, 16.
Yeah I know, but there isn't enough data to crunch numbers. The only numbers I really have are wavelengths. We can make some up? In any event, you gotta be able to visualize the mode shapes.

Just a rough back of the envelope figure I get is length of cone is ~.15 meters ~6.1 inches, rounded. That is based off TM211 and the frequency. That .15 meters is a perfect wavelength. The cavity can be operated above or below that so that doesn't inform me of cavity size. But if the test chamber is 30 inches wide, it doesn't jive. Looking at the pics.

I need to be able to do what this guy: http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html is doing. Because I don't have the COMSOL software.

And see if the dielectric is in or out of the field more or less, when conditions are like page 18.

A hard look at figure 18, looks like the small end is about 6 inches wide to me, and the other end 12 inches. I see 2 magnetic modes in width (blue) and the the gray circle appears to be about the width of the PE discs. I can't say for sure because there is no depth... :(

When I get home to Autocad, I can do a raster image import and draw some construction lines, and hopefully get some dims from the bottom pic.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/18/2014 01:42 pm
Yes, it would help if you can attach a file that people without AutoCad can open.  I tried to open your dxf file with Mathematica and this is what I got:

You want some cheese with your whine?
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 02:03 pm

...the wavelength is so short ...

As you stated, McCulloch's formula

Force =(   PowerInput*Q / (frequency)  )*(1/SmallDiameter-1/LargeDiameter)

needs to be modified to something like this, to be consistent with his theory

Force =(   PowerInput*Q / (c/wavelength) )*(1/SmallDiameter-1/LargeDiameter)

Question is, what is the wavelength to use in the above formula. In McCulloch's theory this wavelength is defined as the peak wavelength of the Unruh energy spectrum, the wavelength that corresponds to the maximum energy in the Unruh spectrum  (see page 6 of http://arxiv.org/pdf/astro-ph/0612599v1.pdf  )



CHOICE 1:  Using the total cavity length (where totalCavityLength=LengthOfCylinder+LengthOfCone)

Force =(   PowerInput*Q / fL)*(1/SmallDiameter-1/LargeDiameter)

where fL = c/(2*totalCavityLength)

essentially assuming that the wavelength that corresponds to the maximum energy in the Unruh spectrum has 2 times the same length as the Total Cavity Length



CHOICE 2:  Using the multiple of the microwave wavelength that fits inside the total cavity length

Force =(   PowerInput*Q / fIP)*(1/SmallDiameter-1/LargeDiameter)

where fIP=microwaveFrequency/IntegerPart[2*totalCavityLength / (c/microwaveFrequency)]

where IntegerPart is the function that takes only the integer part of a number.  For example, IntegerPart[2.834]=2

essentially assuming that the wavelength that corresponds to the maximum energy in the Unruh spectrum has the same length as the largest multiple of the microwave wavelength that fits inside the Total Cavity Length



These two choices are identical only when

2*totalCavityLength / (c/microwaveFrequency)=IntegerPart[2*totalCavityLength / (c/microwaveFrequency)]

Otherwise these two choices differ only by the fractional part of the ratio 2*totalCavityLength / (c/microwaveFrequency)



EDIT: Thanks to aero for catching an error I made missing the factor of 2
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 02:16 pm
Yes, it would help if you can attach a file that people without AutoCad can open.  I tried to open your dxf file with Mathematica and this is what I got:

You want some cheese with your whine?

Hey hey kernosabe.

Nicely done!

OK now one can see why numbers are slightly different:  parallax.   :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 03:21 pm
I still see writing wanting to add the need of extraneous "external forces" to conservation of momentum and conservation of energy and variational principles.  Those principles already contain the concept of force in them, so it doesn't need to be added. It is well known that Newton's law follows from the Lagrangian. The Lagrangian is more general.  Newton was clear as to the fact that he could not explain the force of gravity, which he just postulated.  In General Relativity, the force of gravity is not explained as a force either,  gravity results from the geodesic motion in 4 dimensional spacetime.  No graviton particles have ever been found yet we calculate the effects of the force of gravity ever since Newton, and with Einstein more accurately. 
Physical problems are solved with conservation principles like conservation of momentum, conservation of energy, and variational principles.  There is no "force principle". In Weight = m g, the force of gravity is never explained, it is postulated.  F = ma applies to rigid bodies, to solve actual problems in continuum mechanics one has to use the concept of stress tensor and solve the equations based on conservation principles and variational principles.  To obtain forces one has to integrate the equations over given surface areas.
F=ma is a simple form of the equations of motion that follow from the Lagrangian.  F=ma is taught in elementary Physics courses, at the level of rigid bodies and lumped masses, and non-canonical equations.  The Lagrangian and variational principles is taught in more advanced courses.  In Mechanics this is known from the time of Euler and ultimately Cauchy, who precisely defined the concept of stress tensor.  The concept of force in mechanics has always remained an intuitive postulate.  It is a postulate (see Truesdell books on Rational Mechanics).  The equilibrium equations (such as Newton's law) for complicated systems follow from the Lagrangian and the Hamiltonian.   

The Lagrangian is equivalent to Newton's laws of motion, but it has the advantage that it takes the same form in any system of generalized coordinates, and it is better suited to generalizations.

For this case, where we have an inverted pendulum with nonlinear coupled modes, for example, it can be solved readily with the Lagrangian (and Newton's equlibrium equations in canonical form follow automatically from it, which would have been extremely difficult to obtain in canonical form otherwise).

If McCulloch's inertial modification theory applies to the microwave EM drives (a big if that is some distance from being shown) the motion and the force follow from conservation of momentum under inertial modification due to Unruh radiation.  The McCulloch force can be computed and he shows a formula for that force.  As to what is the physical mechanism behind the motion and the force, the physical mechanism is the Unruh radiation, this is clearly pointed out in McCulloch's papers.  Now, one may question (with good justification) that inertial modification even if it applies to other particles it may not apply to "massless" particles like photons, or even if it ever applies to photons, one may pose that it may apply to photons under extreme black-hole gravitational attraction but not to photons in a microwave drive, but the discussion about lack of "external forces" is a distraction.  The same argument could be used to argue that a mass cannot be accelerated by gravity because the gravity "force" has never been explained as a force arising from a particle (we have never found gravitons).

Also the effort to try to explain everything in terms of analogies to the forces that humans are familiar with in their everyday life, although natural for all human beings, it is ultimately misguided when applied to photons.  Feynman taught that in analyzing photons one should completely dispense with any analogies to forces that humans are familiar with. Photons are both a particle and a wave.  They are not a particle. They are not a wave.  They behave in counter-intuitive ways (i.e. 2 slit experiment). General physics principles like conservation of momentum, conservation of energy and variational principles should be used instead of appealing to the intuitive concept of forces on rigid bodies. Newton's law follows from the Lagrangian.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/18/2014 04:21 pm
Nicely done!

Tanks. (https://www.google.com/search?q=cartoon+with+tanks&client=firefox-a&hs=wnD&rls=org.mozilla:en-US:official&channel=nts&source=lnms&tbm=isch&sa=X&ei=nZFCVLbRJZLlsATxv4HoAQ&ved=0CAgQ_AUoAQ&biw=1158&bih=618&dpr=1.25#rls=org.mozilla:en-US:official&channel=nts&tbm=isch&q=political+cartoon+with+tanks)

Sometimes Mohammed cain't git to da mountain, an he cai'nt git da mountain to come to him, so he must draw and eyeball the dimensions of the mountain.

As you can see, the placement of the guidelines is a complete and total judgement call, and we don't know if there's a squeeze factor in the original JPEG. Were I trying to keep something secret while pretending to reveal all, that's what I would do, when 'publishing' my work.

That, and silence on important details.  What the heck izzat geared gizmo, fo' zample? and how many ounces of CHBW are there in the copper can?

moving right along, howsomeever.  you got some frequencies.  You got some dimensions.  Izzit possible to run one of Frobnicat's programs where he plays multiple frequencies around multiple copper can dimensions, within some kinda statistical limits?  And see if anything rings a bell, so to speak?

You da immam.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 04:36 pm

It is moot whether or not gravity has been explained as a graviton, entropic, geometric, or whatever. It is a force. Objects in a gravitational field experience that force.

Objects such as copper cans must experience a force in order to experience a change in their acceleration.

Any notion that momentum can be gained from photons inside a cavity is just false. It has no bearing on wave/particle duality. A massless particle in motion has momentum. Unfortunately you can't use that momentum to gain linear momentum from within a closed system. The sum of all forces inside cancel out.

For macro objects, like copper cans, it is a simple as F=MA. No giant paragraph needed.

This one simple concept seems to get lots of people.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 04:40 pm
Nicely done!


"That, and silence on important details.  What the heck izzat geared gizmo, fo' zample? and how many ounces of CHBW are there in the copper can?"


Those gears are Shawyer's answer to compensating for doppler shift by lengthening and shortening the cavity accordingly.

There's 2 ways to bring a cavity into resonance. 1: change the size of the cavity to match your frequency 2: change your frequency to match the cavity.

Smaller cavity=higher frequency.

My sources are http://www.emdrive.com/IAC13paper17254.v2.pdf and his latest patent someone recently posted.
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 04:48 pm
On one hand "gravitational attraction" is a force (never mind explaining why it is a force) and reaction from jet exhaust is also a force (using circular arguments based on action and reaction). 

The concept of force intuitive remains and since it was explained in elementary physics it is comforting, but Unruh radiation cannot lead to a force, well just because Unruh radiation is not familiar, unlike the already assimilated concepts of gravitational attraction (which drops apples on people's heads to wake them up) or a jet exhaust (which ejects water on people's faces from a water hose).

Every unexplained force that drops things on people's faces to wake them up and were discussed in elementary physics qualify as a force.

Forces that do not drop things on people faces and were not learnt in elementary physics must not be forces, well ... because they are just not familiar.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 04:57 pm
On one hand "gravitational attraction" is a force (never mind explaining why it is a force) and reaction from jet exhaust is also a force (using circular arguments based on action and reaction). 

The concept of force intuitive remains and since it was explained in elementary physics it is comforting, but Unruh radiation cannot lead to a force, well just because Unruh radiation is not familiar, unlike the already assimilated concepts of gravitational attraction (which drops apples on people's heads to wake them up) or a jet exhaust (which ejects water on people's faces from a water hose).

Every unexplained force that drops things on people's faces to wake them up and were discussed in elementary physics qualify as a force.

Forces that do not drop things on people faces and were not learnt in elementary physics must not be forces, well ... because they are just not familiar.

Seems like we're starting to converge again here. Now we can have forces from Unruh radiation all day until the cows come home, but if that Unruh radiation derived force is happening inside the device, it ain't gonna move it. Unruh radiation derived force happening outside the copper can? Sure sign me up. The trouble is though, for you to experience that Unruh radiation outside the copper can, you have to be accelerating your butt off SR style. If we can do that, who needs hypothetical Unruh radiation.

I just want to add that the whole reason I got so hyped up on modified inertia in the first place was just to give spacetime an asymmetry inside the cavity, nothing more, so I could give a particle (or anything else) more inertia heading aft, vs heading forward. Just trying to bend but not break those pesky conservation laws. I was keen on knowing that EM radiation is rapidly oscillating electrical and magnetic energy collapsing into itself and I couldn't get a push or pull out of that, nor could I exploit the poynting vector because of the closed system. My whole assumption is that since inertia is the net aggregate of all interactions emanating from all corners of our infinite cosmos, I could create a different cosmos inside a copper can by blocking some of those interactions from getting inside. I surmised that the net shape of those interactions would be less spherical inside vs outside, inducing a small inertial bias. Sounds stupid I know. I wasn't trying to get it to fly that way. Just a small perturbation that can be exploited, and improved upon with better technology, like those neato meta materials that make rf bend right around them. The net effect was to get a game of pool where it was easier to hit the balls one way vs another, instead of equal in all directions.
Title: Re: EM Drive Developments
Post by: aero on 10/18/2014 05:13 pm
One thing I note about some of the theory papers linked here is that they insist on using inverse square laws to describe things. That normally is correct but the inside of the resonate cavity is not a normal situation.

The far field only reaches the length of the cavity and the near field lines are parallel. Things from the cavity ends cannot be considered as points (1/r^2) but rather should be treated as planar sources (1/r).
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 05:13 pm
It is elementary Mr. Watson.  If (and this is a big if that remains a long distance from being shown) the inertia  gets modified differentially fore and aft by Unruh radiation, in order for  momentum to be conserved there must be acceleration.  Conservation of momentum is a paramount principle in Physics reigning supreme in all known Physics from General Relativity to Quantum Mechanics.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 05:17 pm
It is elementary Mr. Watson.  If (and this is a big if that remains a long distance from being shown) the inertia of the cupric walls gets modified differentially fore and aft by Unruh radiation, in order for  momentum to be conserved the cupric walls must be accelerated.  Conservation of momentum is a paramount principle in Physics reigning supreme in all known Physics from General Relativity to Quantum Mechanics.

Yes you are exactly right Inspector, but those cupric walls are all connected to each other by side walls. No net force.
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 05:24 pm
Mr. Watson, these are the primordial assumptions that should be analyzed:

1) is it possible to modify the inertia of photons?

2) is it possible to modify the inertia of photons due to Unruh radiation?

3) even if accelerations present in massive black holes could modify the inertia of photons due to Unruh radiation, is it possible for the inertia of photons in a microwave cavity to be modified?

4) what change in momentum could be responsible for modifying the inertia of photons in a microwave cavity? Is it the change in direction of photons hitting the walls? Or is the "acceleration" resulting from Energy-Mass equivalence of the photon, c^2/wavelength or  c^2/(wavelength/2) an applicable concept for inertia modification?

5) if the inertia of photons in a microwave cavity could be modified fore and after in a microwave cavity, due to Unruh radiation, will conservation of momentum lead to a movement of the cupric walls or would it instead lead to a frequency shifting of the photons or to an expansion-compression movement of the photons inside the cupric walls without any rigid body movement of the cupric walls?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 05:51 pm
Mr. Watson, these are the primordial assumptions that should be analyzed:


1) is it possible to modify the inertia of photons?

2) is it possible to modify the inertia of photons due to Unruh radiation?

3) even if accelerations present in massive black holes could modify the inertia of photons due to Unruh radiation, is it possible for the inertia of photons in a microwave cavity to be modified?

4) what change in momentum could be responsible for modifying the inertia of photons in a microwave cavity? Is it the change in direction of photons hitting the walls? Or is the "acceleration" resulting from Energy-Mass equivalence of the photon, c^2/wavelength or  c^2/(wavelength/2) an applicable concept for inertia modification?

5) if the inertia of photons in a microwave cavity could be modified fore and after in a microwave cavity, due to Unruh radiation, will conservation of momentum lead to a movement of the cupric walls or would it instead lead to a frequency shifting of the photons or to an expansion-compression movement of the photons inside the cupric walls without any rigid body movement of the cupric walls?

1) is it possible to modify the inertia of photons?

If MiHsC is correct, then yes. By my method? Probably not.

2) is it possible to modify the inertia of photons due to Unruh radiation?

Doesn't make sense to me, no.

3) even if accelerations present in massive black holes could modify the inertia of photons due to Unruh radiation, is it possible for the inertia of photons in a microwave cavity to be modified?

I don't know. Unruh radiation doesn't apply here to photons. Space ships or (insert object here) accelerating experience Unruh radiation, not photons. Photons go at C because of the permittivity and permeability of the vacuum.

4) what change in momentum could be responsible for modifying the inertia of photons in a microwave cavity? Is it the change in direction of photons hitting the walls? Or is the "acceleration" resulting from Energy-Mass equivalence of the photon, c^2/wavelength or  c^2/(wavelength/2) an applicable concept for inertia modification?

Don't get the question again. It doesn't compute. Change in momentum doesn't equal mean inertia was modified. Inertia can change but not be modified. Well everyone agrees that inertia is rooted in distant interactions with cosmos. Some say some interactions, others say just gravity. I say all, near and far. Why play favorites?

5) if the inertia of photons in a microwave cavity could be modified fore and after in a microwave cavity, due to Unruh radiation, will conservation of momentum lead to a movement of the cupric walls or would it instead lead to a frequency shifting of the photons or to an expansion-compression movement of the photons inside the cupric walls without any rigid body movement of the cupric walls?

If the unit is flying through space, the doppler shift is where that whole conservation thing is happening. The walls can't move. I'm gonna get a nosebleed here if I see Unruh radiation one more time.

The whole point of bringing MiHsC into the picture was because I knew that I was forced to both push and pull on the QV equally (via the mysterious dielectric thrust method). What got me so excited was the inertial bias that could result allowing me to push more on the QV, but pull less.
Title: Re: EM Drive Developments
Post by: aero on 10/18/2014 06:30 pm
Mr. Watson, these are the primordial assumptions that should be analyzed:

1) is it possible to modify the inertia of photons?
If Prof. M's theory is correct, then yes - In MiHsC the inertial mass (mi) is modified as mi=m(1-L/4T)
Quote

2) is it possible to modify the inertia of photons due to Unruh radiation?

3) even if accelerations present in massive black holes could modify the inertia of photons due to Unruh radiation, is it possible for the inertia of photons in a microwave cavity to be modified?

4) what change in momentum could be responsible for modifying the inertia of photons in a microwave cavity? Is it the change in direction of photons hitting the walls? Or is the "acceleration" resulting from Energy-Mass equivalence of the photon, c^2/wavelength or  c^2/(wavelength/2) an applicable concept for inertia modification?

5) if the inertia of photons in a microwave cavity could be modified fore and after in a microwave cavity, due to Unruh radiation, will conservation of momentum lead to a movement of the cupric walls or would it instead lead to a frequency shifting of the photons or to an expansion-compression movement of the photons inside the cupric walls without any rigid body movement of the cupric walls?

I'll try to extend my blind cat/hot stove analogy. But the photons approaching the cavity ends are not really blind even though they are moving with velocity c, what they see is the wall as it appeared some delta time earlier, the time required for the Unruh waves to travel from the wall to the photons current distance from the wall. I don't know that that pertains.

When the photons strike the wall they are absorbed and re-emitted with mi=m(1-L/4T), that is, a lower inertial mass. But they are photons so their velocity remains fixed at c. Therefore their energy and momentum is reduced. But Energy of a photon, E = hc/lamda and momentum = hf/c . The photons are no longer seeing the Unruh waves so normal physics must hold, the Energy mass of the photon must revert to hc/lamda but E is less than it was before it was reflected so lamda increases to conserve energy.

Now the photon travels to the other end of the cavity where the Unruh field is stronger so it is absorbed and re-emitted with less momentum with the momentum difference being greater than the momentum difference at the weak field end (the big end). Again the wavelength increases to conserve energy. The momentum differences are absorbed by the cavity ends but the bigger momentum difference pulls the whole cavity in that direction. Note that there would be a Doppler effect in this explanation. Problem - This does not seem to violate the 1/c condition.

Now, if you don't like that explanation, try this one.

The photon smashes into the wall is absorbed and re-emitted. But due to some unknown effect, the photon is re-emitted with more rotational momentum and less linear momentum. Momentum and energy are conserved but rotational momentum does not contribute to force. Now, why would momentum transfer from linear to rotational in the process of being absorbed and re-emitted? And would that result in a force?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 07:03 pm
Mr. Watson, these are the primordial assumptions that should be analyzed:

1) is it possible to modify the inertia of photons?
If Prof. M's theory is correct, then yes - In MiHsC the inertial mass (mi) is modified as mi=m(1-L/4T)
Quote

2) is it possible to modify the inertia of photons due to Unruh radiation?

3) even if accelerations present in massive black holes could modify the inertia of photons due to Unruh radiation, is it possible for the inertia of photons in a microwave cavity to be modified?

4) what change in momentum could be responsible for modifying the inertia of photons in a microwave cavity? Is it the change in direction of photons hitting the walls? Or is the "acceleration" resulting from Energy-Mass equivalence of the photon, c^2/wavelength or  c^2/(wavelength/2) an applicable concept for inertia modification?

5) if the inertia of photons in a microwave cavity could be modified fore and after in a microwave cavity, due to Unruh radiation, will conservation of momentum lead to a movement of the cupric walls or would it instead lead to a frequency shifting of the photons or to an expansion-compression movement of the photons inside the cupric walls without any rigid body movement of the cupric walls?

I'll try to extend my blind cat/hot stove analogy. But the photons approaching the cavity ends are not really blind even though they are moving with velocity c, what they see is the wall as it appeared some delta time earlier, the time required for the Unruh waves to travel from the wall to the photons current distance from the wall. I don't know that that pertains.

When the photons strike the wall they are absorbed and re-emitted with mi=m(1-L/4T), that is, a lower inertial mass. But they are photons so their velocity remains fixed at c. Therefore their energy and momentum is reduced. But Energy of a photon, E = hc/lamda and momentum = hf/c . The photons are no longer seeing the Unruh waves so normal physics must hold, the Energy mass of the photon must revert to hc/lamda but E is less than it was before it was reflected so lamda increases to conserve energy.

Now the photon travels to the other end of the cavity where the Unruh field is stronger so it is absorbed and re-emitted with less momentum with the momentum difference being greater than the momentum difference at the weak field end (the big end). Again the wavelength increases to conserve energy. The momentum differences are absorbed by the cavity ends but the bigger momentum difference pulls the whole cavity in that direction. Note that there would be a Doppler effect in this explanation. Problem - This does not seem to violate the 1/c condition.

Now, if you don't like that explanation, try this one.

The photon smashes into the wall is absorbed and re-emitted. But due to some unknown effect, the photon is re-emitted with more rotational momentum and less linear momentum. Momentum and energy are conserved but rotational momentum does not contribute to force. Now, why would momentum transfer from linear to rotational in the process of being absorbed and re-emitted? And would that result in a force?

Given what I've recently learned about momentum wrt EM radiation, there isn't a way to get linear momentum in a closed system. We're stuck with angular momentum. (Much to my dismay) In addition to that, I realized I couldn't use the poynting vector to do work either because of the whole system being an enclosed can. Even if I was pushing on the QV in some kind of Star Trek way, I'd have to push and pull equally. So I started resorting to finding asymmetries, like modified inertia and chiral molecules. I even postulated pulsing the rf on and off, more time on than off. That hidden momentum thing was the final nail in my coffin until I got back on board with why I went nuts for modified inertia in the first place. I gotta push more than I pull if I want to move. The only way to do that is modified inertia (that I can think of).
Title: Re: EM Drive Developments
Post by: aero on 10/18/2014 07:26 pm
Quote
Given what I've recently learned about momentum wrt EM radiation, there isn't a way to get linear momentum in a closed system.

Could you explain that or give a reference?
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 07:54 pm
Quote
Given what I've recently learned about momentum wrt EM radiation, there isn't a way to get linear momentum in a closed system.

Could you explain that or give a reference?

Sounds to me like there was a confusion regarding the Abraham-Minkowski paradox, and not taking into account hidden momentum properly.  Shockley (the inventor of the transistor) showed this a long time ago (and even Einstein himself).  No definition of the electromagnetic stress tensor (Minkowski uses an unsymmetric definition that leads people astray) can get away from the fact that the center of mass cannot accelerate if it is a closed system.  Glad to see at least this is not longer a source of controversy here.

The proper question is whether it is a closed system.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/18/2014 07:59 pm
Quote
Given what I've recently learned about momentum wrt EM radiation, there isn't a way to get linear momentum in a closed system.

Could you explain that or give a reference?

Unrelated to Abraham-Minkowski controversy. Most recently here: I posted about this a lot. Not getting through.
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1272847#msg1272847

Title: Re: EM Drive Developments
Post by: aero on 10/18/2014 08:00 pm
Quote
Given what I've recently learned about momentum wrt EM radiation, there isn't a way to get linear momentum in a closed system.

Could you explain that or give a reference?
Most recently here: I posted about this a lot. Not getting through.
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1272847#msg1272847

Thanks. You now have my attention, for what its worth.
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 08:03 pm
What have the Professors in Raleigh shown in 2009 that Shockley didn't show before?

And Poincare wrote about hidden momentum precisely in this context even before Einstein's theory of relativity...
Title: Re: EM Drive Developments
Post by: aero on 10/18/2014 08:06 pm
I have a question. Because these thruster cavities have very high Q don't they ring for a long time after the power is switched off? How long, because if the ringing is long enough shouldn't we see a tail off on the thrust trace shown in the various reports on the experiments?

What is the rule for diminishing stored power in the cavity once the power is switched off?

Of course if the thrust is due to Unruh waves, then thrust would stop instantly once the stored power dropped below a threshold.
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 08:09 pm
I have a question. Because these thruster cavities have very high Q don't they ring for a long time after the power is switched off? How long, because if the ringing is long enough shouldn't we see a tail off on the thrust trace shown in the various reports on the experiments?

What is the rule for diminishing stored power in the cavity once the power is switched off?

Of course if the thrust is due to Unruh waves, then thrust would stop instantly once the stored power dropped below a threshold.

Take a look at Shawyer's results.

There is thrust even after the power stops.
Title: Re: EM Drive Developments
Post by: aero on 10/18/2014 08:44 pm
I have a question. Because these thruster cavities have very high Q don't they ring for a long time after the power is switched off? How long, because if the ringing is long enough shouldn't we see a tail off on the thrust trace shown in the various reports on the experiments?

What is the rule for diminishing stored power in the cavity once the power is switched off?

Of course if the thrust is due to Unruh waves, then thrust would stop instantly once the stored power dropped below a threshold.

Take a look at Shawyer's results.

There is thrust even after the power stops.

I see that. Doesn't that tell us something?

Anyway - Its Saturday afternoon and I'm going to take a break from NSF.
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 09:05 pm
I have a question. Because these thruster cavities have very high Q don't they ring for a long time after the power is switched off? How long, because if the ringing is long enough shouldn't we see a tail off on the thrust trace shown in the various reports on the experiments?

What is the rule for diminishing stored power in the cavity once the power is switched off?

Of course if the thrust is due to Unruh waves, then thrust would stop instantly once the stored power dropped below a threshold.

Take a look at Shawyer's results.

There is thrust even after the power stops.

I see that. Doesn't that tell us something?

Anyway - Its Saturday afternoon and I'm going to take a break from NSF.

Yes, excellent point.  It shows the importance of Q and resonance, and something that the deniers of the importance of Q and resonance have to contend with in order to explain the thrust response.

Now, putting on my denier hat, one possible alternative for the delayed response is thermal but it would have to be shown that it is compatible with Fourier's time due to thermal diffusivity, for example.  Also, if it is a thermal artifact one would expect an approximately exponentially decaying rise and a symmetrical exponentially decaying fall, but it is evident from the graph that the fall is not symmetric, on the contrary, it is much faster than the rise.
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/18/2014 10:54 pm
The Shawyer chart reminds me of a Tracy-Widom distribution.
Title: Re: EM Drive Developments
Post by: Rodal on 10/18/2014 11:07 pm
The Shawyer chart reminds me of a Tracy-Widom distribution.

Thank you, I learned something new today.  I didn't know about this distribution. 

<<Whereas “uncorrelated” random variables such as test scores splay out into the bell-shaped Gaussian distribution, interacting species and other “correlated” variables give rise to a more complicated statistical curve. Steeper on the left than the right (or viceversa), the curve has a shape that depends on N, the number of variables.>>

(http://inspirehep.net/record/808586/files/mpc1.png)

(http://www.quantamagazine.org/wp-content/uploads/2014/10/TWGraph600.jpg)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/18/2014 11:12 pm
8, 12, 16

You give them the material before the test and they still get the answer wrong.

Mass # 1 illustrated first.
Mass #2 Illustrated second.

So.... what's the latest on NSF?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/18/2014 11:32 pm
I have a question. Because these thruster cavities have very high Q don't they ring for a long time after the power is switched off? How long, because if the ringing is long enough shouldn't we see a tail off on the thrust trace shown in the various reports on the experiments?

What is the rule for diminishing stored power in the cavity once the power is switched off?

Of course if the thrust is due to Unruh waves, then thrust would stop instantly once the stored power dropped below a threshold.

Take a look at Shawyer's results.

There is thrust even after the power stops.

Time constant of a resonant EM wave decay for one dimensional cavity of length l : tau = Ql/c
Say Q=50000 l=.5m (give or take) -> 83µs
At 1.15ms after switch off, the energy is ringing at one millionth its initial value. I don't see this kind of millisecond temporal resolution in the charts so far. This is irrelevant.

There could be delay in the power off (DC or RF generator), there is certainly inertia in the mechanical balance, there could be delay in thermal effects. But as far as heavy mechanical balance time constants are concerned, photons switch off can be considered instantaneous until Q reaches at least 50000000

edit: or was it the half time rather than tau ? I have a doubt. Anyway, the above would stand correct by just replacing one millionth by around 1/700000 th 
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 12:10 am
I have a question. Because these thruster cavities have very high Q don't they ring for a long time after the power is switched off? How long, because if the ringing is long enough shouldn't we see a tail off on the thrust trace shown in the various reports on the experiments?

What is the rule for diminishing stored power in the cavity once the power is switched off?

Of course if the thrust is due to Unruh waves, then thrust would stop instantly once the stored power dropped below a threshold.

Take a look at Shawyer's results.

There is thrust even after the power stops.

Time constant of a resonant EM wave decay for one dimensional cavity of length l : tau = Ql/c
Say Q=50000 l=.5m (give or take) -> 83µs
At 1.15ms after switch off, the energy is ringing at one millionth its initial value. I don't see this kind of millisecond temporal resolution in the charts so far. This is irrelevant.

There could be delay in the power off (DC or RF generator), there is certainly inertia in the mechanical balance, there could be delay in thermal effects. But as far as heavy mechanical balance time constants are concerned, photons switch off can be considered instantaneous until Q reaches at least 50000000

edit: or was it the half time rather than tau ? I have a doubt. Anyway, the above would stand correct by just replacing one millionth by around 1/700000 th
Energy decay in a resonating cavity ~ Exp[ - omega * t / Q ] = Exp [ - t / τ]

 τ = Q/ omega =  Q / (2 Pi f) = 50000 / (2 Pi 1.9 * 10 ^9 1/s) = 4 microseconds

 τ is the time at which the amplitude is reduced to 1/e = 37% of its initial value.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/19/2014 12:16 am
Well everyone agrees that inertia is rooted in distant interactions with cosmos. Some say some interactions, others say just gravity. I say all, near and far. Why play favorites?

If by "rooted in distant interactions with cosmos" you mean some Machian principle, then I don't agree. Regardless of the role "Mach principle" have played for SR and GR genesis, this principle, in its various interpretations, is nonsense to me.

Is there a problem with inertia ? What is the problem with inertia ? Why would we need to implicate the whole cosmos when local phenomena can be explained in local fields on a small patch of curved spacetime with local coordinates in inertial frame ? Local vacuum can make a difference between inertial and non inertial trajectories (accelerated relative to free falling). There is no intrinsic local absolute 0 speed, but there is intrinsic local absolute 0 acceleration : does that make insurmountable theoretical problems, or fail at predicting some well proven experimental effects ? Does that have to be explained ?

I don't want to trigger a flow of scholarly answers here, just stating some astonishment.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 12:26 am
Well everyone agrees that inertia is rooted in distant interactions with cosmos. Some say some interactions, others say just gravity. I say all, near and far. Why play favorites?

If by "rooted in distant interactions with cosmos" you mean some Machian principle, then I don't agree. Regardless of the role "Mach principle" have played for SR and GR genesis, this principle, in its various interpretations, is nonsense to me.

Is there a problem with inertia ? What is the problem with inertia ? Why would we need to implicate the whole cosmos when local phenomena can be explained in local fields on a small patch of curved spacetime with local coordinates in inertial frame ? Local vacuum can make a difference between inertial and non inertial trajectories (accelerated relative to free falling). There is no intrinsic local absolute 0 speed, but there is intrinsic local absolute 0 acceleration : does that make insurmountable theoretical problems, or fail at predicting some well proven experimental effects ? Does that have to be explained ?

I don't want to trigger a flow of scholarly answers here, just stating some astonishment.

Very well stated.  But what if inertia can be explained by a local field that goes to some extent beyond the cavity and depends on the cavity shape?

For example, an object inside water has added inertia due to the water around it.  And it is not due to viscosity..  It is due to the density of the fluid that the object is immersed in.
The inertia of an object immersed in water is greater than the inertia of an object in a vacuum.  This is well known of course, and it affects the frequency of vibration of objects immersed in water.  It is called "added mass" effect.

This added mass has nothing to do with distant interactions.  It has nothing to do with distant water.
The added mass is a tensor (referred to as the induced mass tensor), it has components that dependon the direction of motion of the body. Some components of the added mass tensor have dimension of mass, but cross-components can have dimensions of mass × length and mass × length ^2.

Only for simple objects (like a sphere) one can easily compute the added mass.

For some other simple shapes, for example an airfoil inside water it is complicated.  For a simple geometry one can use a Lagrangian to compute, for complicated geometries one has to do a numerical analysis.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/19/2014 12:49 am
.../...
Time constant of a resonant EM wave decay for one dimensional cavity of length l : tau = Ql/c
Say Q=50000 l=.5m (give or take) -> 83µs
.../...
Energy decay in a resonating cavity ~ Exp[ - omega * t / Q ] = Exp [ - t / τ]

 τ = Q/ omega =  Q / (2 Pi f) = 50000 / (2 Pi 1.9 * 10 ^9 1/s) = 4 microseconds

 τ is the time at which the amplitude is reduced to 1/e = 37% of its initial value.

mm, I thought Q could be interpreted roughly as the mean number of times a photon bounces back and forth before being absorbed. This is not far off for fundamental mode but would be quite different for much higher harmonics. Maybe this is just a matter of definition, your definition τ = Q/ omega makes perfect sense. I'm all confused. Can you help clarify because I suspect also some poor understanding of what resonance really is :
At fixed f, a 1d cavity with mirrors at both ends of fixed 99% reflectivity will ring for a proportionally longer time if it is longer in size, no ? So if tau is to be proportional to Q, that we both agree, this would mean that longer cavity would have better Q ? That won't appear in you formula. Perplexum.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 12:58 am
.../...
Time constant of a resonant EM wave decay for one dimensional cavity of length l : tau = Ql/c
Say Q=50000 l=.5m (give or take) -> 83µs
.../...
Energy decay in a resonating cavity ~ Exp[ - omega * t / Q ] = Exp [ - t / τ]

 τ = Q/ omega =  Q / (2 Pi f) = 50000 / (2 Pi 1.9 * 10 ^9 1/s) = 4 microseconds

 τ is the time at which the amplitude is reduced to 1/e = 37% of its initial value.

mm, I thought Q could be interpreted roughly as the mean number of time a photon bounces back and forth before being absorbed. This is not far off for fundamental mode but would be quite different for much higher harmonics. Maybe this is just a matter of definition, your definition τ = Q/ omega makes perfect sense. I'm all confused. Can you help clarify because I suspect also some poor understanding of what resonance really is :
At fixed f, a 1d cavity with mirrors at both ends of fixed 99% reflectivity will ring for a proportionally longer time if it is longer in size, no ? So if tau is to be proportional to Q, that we both agree, this would mean that longer cavity would have better Q ? That won't appear in you formula. Perplexum.

For a resonant cavity the dimensions of the cavity govern the frequency.  I only wrote it that way because in the simplified McCulloch formula and in your almost-Infinite number of formulas program  :) we just used the microwave frequency.

Instead of a rectangular waveguide with open ends we have a rectangular waveguide terminated at both ends by conducting walls which makes it a resonant cavity.  Instead of having a wave propagating axially in a waveguide,  we have to meet the boundary conditions at both ends which entails equal forward- and backward-propagating waves that form a standing wave.  Unlike rectangular waveguides with open ends that propagate any frequency above cut-off, cavity resonators operate only at specific resonant frequencies (in order to match all boundary conditions).

It is clear that the tested EM Drives had high Q.  For NASA Eagleworks we have the S22 plot showing resonance vs. frequency. Therefore the EM Drives were not waveguides but resonant cavities: they must have had both ends made of highly conducting copper, and the inside surfaces must have been highly polished copper (in order to have high Q).

For a perfectly-conducting hollow rectangular "box" of dimensions of width w, height h, and length d, where
d ≥w≥h,  filled with a medium characterized by permittivity  ε, permeability μ and electrical conductivity σ, the lowest resonant frequency ω is "101" mode.  The boundary conditions dictate that the oscillating electric field's x component to disappear on the y-z walls, the y component to disappear on the x-z walls and the z component to disappear on the x-y walls. Since boundary conditions can not be met unless at least two of the quantum numbers m, n, and p are non-zero, the lowest resonant frequency is associated with the two longest dimensions, d and w.  It is given by  (where c=speed of light in a vacuum only when the interior cavity is tested in a vacuum of course  :)   )

ω = Pi c Sqrt[   (1/w)^2 + (1/d)^2    ] (radians / second)

Some people here are still very interested in the dielectric.  In a dielectric, the speed of light is lower of course, so let's allow for the case where the medium is a dielectric, for generality:

c = 1/ Sqrt[με]

In general the permittivity  ε, permeability μ and electrical conductivity σ can be complex, frequency dependent, and anisotropic functions of field direction. They can also be functions of density, temperature, field strength, and other quantities (they can depend on the electric field and the magnetic field).

ω = Pi Sqrt[   ((1/w)^2 + (1/d)^2)/(με)    ] (radians / second)

Assuming Q >>1.

The electric-energy/dissipation density ratio everywhere is ε/2σ.  The stored electric and magnetic energy are equal. Therefore the total energy stored is two times the average electric energy stored.

Q = ω (total energy stored) / (power dissipated) =  ω ε / σ

Q = Pi Sqrt[   ((1/w)^2 + (1/d)^2)/(με)    ]  ε / σ

so really the time constant ends up being given simply by the medium properties: the permittivity divided by the electrical conductivity:

τ = Q/ ω =  ε / σ

This is for the case in which all losses are produced by the medium (air or vacuum).


for air at 20 deg C

ε = 1.00058986 * 8.8541878176 * 10^(-12) Farad / meter
   = 8.859410 * 10^(-12) Farad / meter
σ = 3*10^(-15) Siemens / meter to 8*10^(-15) Siemens / meter

Therefore the longest possible time constants are:

Minimum τ  = ε / σ =( 8.859410 * 10^(-12) )/( 8*10^(-15) ) seconds
                             = 1107 seconds = 18 minutes

Maximum τ  = ε / σ =( 8.859410 * 10^(-12) )/( 3*10^(-15) ) seconds
                             = 2953 seconds = 49 minutes

c (air) =  299705000 m/s

w (Shawyer Demonstrator) ~ Sqrt[0.28*0.1679] = 0.217 m
d (Shawyer Demonstrator) = 0.345 m

ω = Pi (299705000) Sqrt[   (1/0.217)^2 + (1/0.345)^2    ]
    = 5.126 GHz

f = ω / (2 Pi) = 0.816 GHz

NOTE: Neither Shawyer, nor NASA Eagleworks operated the EM Drive at this lowest fundamental mode, and this calculation is for a rectangular box cavity, instead of a truncated cone.


Those longest possible time constants correspond to these highest possible Q's achievable in air:

Q = (5.126*10^9)*1107   to  (5.126*10^9)*2953
    = 5.67*10^12  to 1.51*10^13

Of course, in practice, the Q's were much lower ~ 4 * 10^5, or 7 orders of magnitude lower. Therefore the time constants were also 7 orders of magnitude lower than those computed above (time constant in microseconds rather than minutes). What limited the Q's (and therefore the time constant) are the losses on the internal copper surface, which was not a perfect conductor.

These calculations are interesting to show what Q's are theoretically possible with a superconductor cavity, as apparently Shawyer is working on.




Also, therefore, the time constant is different in the dielectric.

And by the way, that formula also reminds me, did you allow formulas of the type

Sqrt[   (1/w)^2 + (1/d)^2    ]
 
in your program?

If not, you should in the next iteration...
Title: Re: EM Drive Developments
Post by: frobnicat on 10/19/2014 01:54 am
.../...
For example, an object inside water has added inertia due to the water around it.  And it is not due to viscosity..  It is due to the density of the fluid that the object is immersed in.
The inertia of an object immersed in water is greater than the inertia of an object in a vacuum.  This is well known of course, and it affects the frequency of vibration of objects immersed in water.  It is called "added mass" effect.

This added mass has nothing to do with distant interactions.  It has nothing to do with distant water.
The added mass is a tensor (referred to as the induced mass tensor), it has components that depend on the direction of motion of the body. Some components of the added mass tensor have dimension of mass, but cross-components can have dimensions of mass × length and mass × length ^2.

Only for simple objects (like a sphere) one can easily compute the added mass.

For some other simple shapes, for example an airfoil inside water it is complicated.  For a simple geometry one can use a Lagrangian to compute, for complicated geometries one has to do a numerical analysis.

Excellent analogy dr Rodal. So excellent we must be all the more careful in extrapolating from it.
Let's take superfluid helium to get rid of viscosity (superfluid helium comes cheap in thought experiments).
All right then, does the added mass tensor have something to say different when going on the same axis but on opposite directions ? If it is used to analyse vibrations I guess it is a linearised (or nth order ?) form that is correct only for small moves around, not for moves fast and big enough to generate turbulent flows. Correct ? So for instance, an horizontal plate would have a huge added mass in vertical direction and small in horizontal directions, but not a different mass whether it goes up or down. In this limit of small or slow movements, a cone of vertical axis would also see the same added mass, whether going up or down, in spite of its asymmetry. Correct ?

So in this formalism something can have a different "mass" depending on its position, but it can't have a different mass depending on it going to or leaving a position. The push heavy pull light analogy don't hold for slow moves. It can hold for fast moves but then I'm not sure this still makes sense to see the asymmetric resistance to changes of speed as changes of mass : basically it is a propeller and medium has to be modelled as a separate mass, not as an added mass to the propeller blades.

Or else, move medium boundary or gradient :  lower position of sphere from air into liquid, lower liquid surface so that sphere is no longer immersed, raise sphere, raise liquid, start again. Push heavy, pull light. Ok, but that is quite a work to do (energy to give) in the moving medium, compared to what can be harnessed by the sphere.

For me this is not a problem of how a property like mass can depend on position, but how it can depend on velocity (back and forth) unless the "field" that changes the property is itself dynamic (at great energetic cost).

And resonance is not a magic answer to "recycle" the dynamic of "mass altering" field : say we have a bucket of water excited at resonant frequency, fundamental mode. At the centre of the bucket, the surface of water goes up and down periodically. A sphere is put at such height as to be periodically immersed and emerged(?), slightly raised when out of water, slightly lowered when in water. This can be interesting for the sphere to push heavy and pull light, but someone has to pay the power bill, resonance or not.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 02:14 am
.../...
For example, an object inside water has added inertia due to the water around it.  And it is not due to viscosity..  It is due to the density of the fluid that the object is immersed in.
The inertia of an object immersed in water is greater than the inertia of an object in a vacuum.  This is well known of course, and it affects the frequency of vibration of objects immersed in water.  It is called "added mass" effect.

This added mass has nothing to do with distant interactions.  It has nothing to do with distant water.
The added mass is a tensor (referred to as the induced mass tensor), it has components that depend on the direction of motion of the body. Some components of the added mass tensor have dimension of mass, but cross-components can have dimensions of mass × length and mass × length ^2.

Only for simple objects (like a sphere) one can easily compute the added mass.

For some other simple shapes, for example an airfoil inside water it is complicated.  For a simple geometry one can use a Lagrangian to compute, for complicated geometries one has to do a numerical analysis.

Excellent analogy dr Rodal. So excellent we must be all the more careful in extrapolating from it.
Let's take superfluid helium to get rid of viscosity (superfluid helium comes cheap in thought experiments).
All right then, does the added mass tensor have something to say different when going on the same axis but on opposite directions ? If it is used to analyse vibrations I guess it is a linearised (or nth order ?) form that is correct only for small moves around, not for moves fast and big enough to generate turbulent flows. Correct ? So for instance, an horizontal plate would have a huge added mass in vertical direction and small in horizontal directions, but not a different mass whether it goes up or down. In this limit of small or slow movements, a cone of vertical axis would also see the same added mass, whether going up or down, in spite of its asymmetry. Correct ?

So in this formalism something can have a different "mass" depending on its position, but it can't have a different mass depending on it going to or leaving a position. The push heavy pull light analogy don't hold for slow moves. It can hold for fast moves but then I'm not sure this still makes sense to see the asymmetric resistance to changes of speed as changes of mass : basically it is a propeller and medium has to be modelled as a separate mass, not as an added mass to the propeller blades.

Or else, move medium boundary or gradient :  lower position of sphere from air into liquid, lower liquid surface so that sphere is no longer immersed, raise sphere, raise liquid, start again. Push heavy, pull light. Ok, but that is quite a work to do (energy to give) in the moving medium, compared to what can be harnessed by the sphere.

For me this is not a problem of how a property like mass can depend on position, but how it can depend on velocity (back and forth) unless the "field" that changes the property is itself dynamic (at great energetic cost).

And resonance is not a magic answer to "recycle" the dynamic of "mass altering" field : say we have a bucket of water excited at resonant frequency, fundamental mode. At the centre of the bucket, the surface of water goes up and down periodically. A sphere is put at such height as to be periodically immersed and emerged(?), slightly raised when out of water, slightly lowered when in water. This can be interesting for the sphere to push heavy and pull light, but someone has to pay the power bill, resonance or not.

I remember that a cone positioned in water such that the point of the cone is in the highest position (think of a conehead   :)  ) and the base of the cone is in the lowest position, although it is symmetric fore and aft, when accelerated, the added mass (which in this case has to be calculated numerically and it is not trivial ) is such as to produce a tipping moment on the cone. If you accelerate the center of mass of the cone, the pointy top of the cone will tip forward in the direction of the acceleration.  So the added mass inertia will act as a horizontal force located below the base of the cone (a horizontal force applied as if the cone would virtually extend into the water).

Now, as you said we should be very careful, because if there is something funny going on, no measurements have been performed with these EM Drives linearly accelerating.  In all the measurements the EM Drives are rotating.  So perhaps in free space the EM Drive will rotate  :)


EDIT: Also, when a symmetric body is near a solid wall, its added mass facing the wall is actually larger than its added mass facing the opposite side, so the presence of a wall on one side makes the added mass asymmetric.

This is interesting because in general a mass matrix must be symmetric for a closed system.  But the fluid makes the added mass an open system and hence being close to the wall on one side produces an asymmetry that would not be present in a mass closed system.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/19/2014 02:18 am
And by the way, that formula also reminds me, did you allow formulas of the type

Sqrt[   (1/w)^2 + (1/d)^2    ]
 
in your program?

If not, you should in the next iteration...[/b]

d not in summary table : length not used so far
sqrt((1/a)^2+(1/b)^2) not explicitly allowed, but  (a^-2 + b^-2)^1  and all other terms either -2 0 or 2 allowed, which is equivalent as far as other terms aren't quadratic  (excluding only exoticas like  F=a²/b² PQL/c sqrt(1/a²+1/b²))
good night dr Rodal
Title: Re: EM Drive Developments
Post by: Mulletron on 10/19/2014 06:55 am
Well everyone agrees that inertia is rooted in distant interactions with cosmos. Some say some interactions, others say just gravity. I say all, near and far. Why play favorites?

If by "rooted in distant interactions with cosmos" you mean some Machian principle, then I don't agree. Regardless of the role "Mach principle" have played for SR and GR genesis, this principle, in its various interpretations, is nonsense to me.

Is there a problem with inertia ? What is the problem with inertia ? Why would we need to implicate the whole cosmos when local phenomena can be explained in local fields on a small patch of curved spacetime with local coordinates in inertial frame ? Local vacuum can make a difference between inertial and non inertial trajectories (accelerated relative to free falling). There is no intrinsic local absolute 0 speed, but there is intrinsic local absolute 0 acceleration : does that make insurmountable theoretical problems, or fail at predicting some well proven experimental effects ? Does that have to be explained ?

I don't want to trigger a flow of scholarly answers here, just stating some astonishment.

Yep I'm on board with you. That's why I said, "I say all, near and far. Why play favorites?"

I am disagreeing with "everybody" and all that Machian business regarding distant interactions. It is clear that inertia is dependent on all interactions at all distances, near and far.

Mach simply wasn't as informed about the universe as we are now. We have the benefit of new data.

I keep restating the same things over and over here on this forum.

I've been trying for weeks to put this business of photons experiencing Unruh radiation business to bed. This all happened because of a fundamental mis-attribution of Unruh waves (all possible waves in the vacuum, and the relationship between what modes fit and what modes don't fit, eg. casimir effect) and Unruh radiation (black body radiation felt by accelerating massive objects). Photons can't and don't and won't ever experience Unruh radiation. They can't accelerate. They don't accelerate. They don't have mass. If you want to play with ideas about Unruh radiation, switch to accelerating electrons instead.

TMI on Unruh:
http://www.powershow.com/view1/596fe-ZDc1Z/Radiation_from_Accelerated_Observers_powerpoint_ppt_presentation

The other thing I've been trying to drive home is that the momentum of a photon in an EM field (static or dynamic) doesn't just slam into things and impart linear momentum. The conditions where this is happening is what is important. Solar sails work because they are open to the universe. The devil is in the details. I put references up over and over again attesting to this, with lots of math which is what people love. An EM wave is an AC signal, which oscillates above and below 0, each cycle is 180degrees out of phase. There is no net linear momentum that can be obtained from this. An AC signal pushes for half, and pulls for the other half. The field lines inside the EMdrive are all wrapped up onto themselves, and the device is a giant loop inside. Any radiation pressure you would hope to get can't be used because the walls of the device are connected to all the other walls of the device. EM waves rotate along the axis of travel. This angular momentum is all you get to play with in a closed system.

The final thing I've been trying to drive home is that in a closed system, such as inside the emdrive cavity, all the field lines flow in continuous circles, even the poynting vector is two counter rotating oscillating circles, which diminishes with Q. No useful work can be derived from that either. All the momentum inside emdrive is angular momentum. There is no way to extract linear momentum.


The devil is in the details, and you can't push the I believe button ever, not even once.

This method isn't going to work.
http://www.youtube.com/watch?v=W8qcccZy03s

There is clear data from the Nasa paper (dielectric importance/thrust not scaling with Q) and new insights mentioned above that is being ignored in favor of pet theories based off of faulty assumptions. Respectfully.

Title: Re: EM Drive Developments
Post by: ThinkerX on 10/19/2014 08:29 am
Are we working our way back to Doctor Whites 'virtual particle becoming 'real' for millisecond' premise?  (Hope I stated that correctly.)

Or does that still involve too many major violations of physics for serious consideration?


A thought that's crossed my mind a few times these last few pages.  Maybe this device 'hitches a ride' on space time expansion? 
Title: Re: EM Drive Developments
Post by: Mulletron on 10/19/2014 12:50 pm
For anyone who's interested, this video will cut through all the complexity and explain the origin of conservation laws and their relation to the geometry and symmetry of spacetime. This is directly related to emdrive, the shape of the cavity, and whether the anomalous thrust is a result of heat, magnetic influence, or dielectric thrust, something else, or all, wrt the principle of least action. This is intended to help out those who don't necessarily do science on a regular basis, or don't work in sci tech.

http://www.youtube.com/watch?v=1_MpQG2xXVo

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/19/2014 01:07 pm
8, 12, 16

You give them the material before the test and they still get the answer wrong.

Mass MESS # 1 illustrated first.
Mass MESS #2 Illustrated second.



Well, tanks (instead of thanks) for fix'n that sideways picture

That happened within seconds of posting.  R U stalking me?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/19/2014 01:08 pm
I don't want to trigger a flow of scholarly answers here, just stating some astonishment.

How about wisecracks?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/19/2014 01:13 pm
There is no intrinsic local absolute 0 speed, but there is intrinsic local absolute 0 acceleration ...

And why not? It would be a jiggly wiggly atom seemingly zipping around somewhere in the universe.  Finding it would be problematical.

http://www.youtube.com/watch?v=z45ZkISJXU4
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/19/2014 01:15 pm
Very well stated.  But what if inertia can be explained by a local field that goes to some extent beyond the cavity and depends on the cavity shape?

Primitive man want know what side of equation term "what if?" go on.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/19/2014 01:20 pm
So in this formalism something can have a different "mass" depending on its position, but it can't have a different mass depending on it going to or leaving a position. The push heavy pull light analogy don't hold for slow moves. It can hold for fast moves but then I'm not sure this still makes sense to see the asymmetric resistance to changes of speed as changes of mass : basically it is a propeller and medium has to be modelled as a separate mass, not as an added mass to the propeller blades.

Back to the ether, I see.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 01:31 pm
So in this formalism something can have a different "mass" depending on its position, but it can't have a different mass depending on it going to or leaving a position. The push heavy pull light analogy don't hold for slow moves. It can hold for fast moves but then I'm not sure this still makes sense to see the asymmetric resistance to changes of speed as changes of mass : basically it is a propeller and medium has to be modelled as a separate mass, not as an added mass to the propeller blades.

Back to the ether, I see.

Sometimes I just flat out don't get it
You say potato I say potato,
you say tomato I say tomato,
you say Noether and I say either
you say ether and I say neither
either, ether, Noether, neither
you eat potato and I eat potato
tomato, tomato, potato, potato
you say after and I say laughter
you say ether, I say aether
ether, aether, Noether, neither...
let's call the whole thing off...
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/19/2014 01:37 pm
Well everyone agrees that inertia is rooted in distant interactions with cosmos. Some say some interactions, others say just gravity. I say all, near and far. Why play favorites?

If by "rooted in distant interactions with cosmos" you mean some Machian principle, then I don't agree. Regardless of the role "Mach principle" have played for SR and GR genesis, this principle, in its various interpretations, is nonsense to me.

... I don't want to trigger a flow of scholarly answers here, just stating some astonishment.

Yep I'm on board with you. That's why I said, "I say all, near and far. Why play favorites?"

I am disagreeing with "everybody" and all that Machian business regarding distant interactions. It is clear that inertia is dependent on all interactions at all distances, near and far.

Mach simply wasn't as informed about the universe as we are now. We have the benefit of new data.

Ja. The same can be said of Maxwell's equations too; but they are still valid to this day.  Just personally, I have an intuition that Mach may have been on tosomething, but that's just an intuition.

I keep restating the same things over and over here on this forum.

Quote from: Mulletron
I've been trying for weeks to put this business of photons experiencing Unruh radiation business to bed. ...

Good doctor been mucho patient with primitive man,  but primitive man still not seeing connection between group velocity and momentum of mass, among other things.

Quote from: Mulletron
The other thing I've been trying to drive home is that the momentum of a photon in an EM field ... doesn't just slam into things and impart linear momentum. ... angular momentum is all you get to play with in a closed system.

Me think you right.

Quote from: Mulletron
The final thing I've been trying to drive home is that ... there is no way to extract linear momentum. ...

The devil is in the details, and you can't push the I believe button ever, not even once.

Me still want believe in ether.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/19/2014 01:38 pm
What?  Emmy Noether?  So she already doesn't believe?????????????????
Title: Re: EM Drive Developments
Post by: Mulletron on 10/19/2014 03:56 pm
Ah memories.....we were so close too. White and March would have been proud. Simultaneous breaking of P and T discrete t symmetries........been trying to warp spacetime ever since.

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269074#msg1269074

Edited for spelling
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 04:10 pm
Ah memories.....we were so close too. White and March would have been proud. Simultaneous breaking of P and T discreet symmetries........been trying to warp spacetime ever since.

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269074#msg1269074

Still looking for magic dielectric to produce thrust based on earliest tests at Eagleworks (before they learned how to control the bandwidth) with unreported Q, with unreported numerical results, conducted at a much higher frequency (way off scale to the right to their S12 plots and their COMSOL Finite Element results ?).

A magic dielectric material not identified in the text of the Eagleworks report, was thought initially to be Teflon (PTFE) then it was suggested to be ceramic, and now thanks to notsosureofit we know to be PE based on the small print of a figure ?

Hanging your hopes on PE (polyethylene) providing thrust somehow, based on a test when Eagleworks did not even have COMSOL Finite Element predictions at what frequencies to expect resonance?

Wouldn't it make more sense to base such hopes on at least a S12 plot (with and without dielectric)?

Ignoring all other data that shows (whether an experimental artifact, or rotational thrust, or linear thrust) the response to be Q and resonance related?

Ignoring the information from wembley that Shawyer no longer uses any dielectric?

And what makes you hope that small disks of Polyethylene (the same plastic used to make garbage bags) can produce thrust in a cupric hollow box?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/19/2014 04:17 pm
Ah memories.....we were so close too. White and March would have been proud. Simultaneous breaking of P and T discreet symmetries........been trying to warp spacetime ever since.

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269074#msg1269074

Still looking for magic dielectric to produce thrust based on earliest tests at Eagleworks (before they learned how to control the bandwidth) with unreported Q, with unreported numerical results, conducted at a much higher frequency (way off scale to the right to their S12 plots and their COMSOL Finite Element results ?).

A magic dielectric material not identified in the text of the Eagleworks report, was thouhgt initially to be Teflon (PTFE) then it was suggested to be ceramic, and now thanks to notsosureofit we know to be PE based on the small print of a figure ?

Hanging your hopes on PE (polyethylene) providing thrust somehow, based on a test when Eagleworks did not even have COMSOL Finite Element predictions at what frequencies to expect resonance?

Wouldn't it make more sense to base such hopes on at least a S12 plot?

Ignoring all other data that shows the response to Q and resonance related?

Ignoring the information from wembley that Shawyer no longer uses any dielectric?

And what makes you hope that Polyethylene (the same plastic used to make garbage bags) can produce thrust?

Well the theory has to fit the experiment. They clearly said the dielectric was important. It isn't magic. Someone has to figure it out.......You realize an oblong spacetime will break P & T right? All the discreet symmetries are broken singularly anyway. This isn't magic.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 04:21 pm
Ah memories.....we were so close too. White and March would have been proud. Simultaneous breaking of P and T discreet symmetries........been trying to warp spacetime ever since.

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269074#msg1269074

Still looking for magic dielectric to produce thrust based on earliest tests at Eagleworks (before they learned how to control the bandwidth) with unreported Q, with unreported numerical results, conducted at a much higher frequency (way off scale to the right to their S12 plots and their COMSOL Finite Element results ?).

A magic dielectric material not identified in the text of the Eagleworks report, was thouhgt initially to be Teflon (PTFE) then it was suggested to be ceramic, and now thanks to notsosureofit we know to be PE based on the small print of a figure ?

Hanging your hopes on PE (polyethylene) providing thrust somehow, based on a test when Eagleworks did not even have COMSOL Finite Element predictions at what frequencies to expect resonance?

Wouldn't it make more sense to base such hopes on at least a S12 plot?

Ignoring all other data that shows the response to Q and resonance related?

Ignoring the information from wembley that Shawyer no longer uses any dielectric?

And what makes you hope that Polyethylene (the same plastic used to make garbage bags) can produce thrust?

Well the theory has to fit the experiment. They clearly said the dielectric was important. It isn't magic. Someone has to figure it out.

So, rather than examine the experimental numerical data of all the tests in the USA, UK and China, the emphasis should be on a statement on a several-pages long report?

And that little statement -all words, no numerical data, and written when they started the report and were learning their way around- should be interpreted as telling us that Polyethylene (the plastic used for garbage bags) being the key to the Magic Kingdom?

(But for the Cannae device it is Teflon, and for Shawyer now -according to wembley - is nothing -no dielectric)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/19/2014 04:24 pm
Ah memories.....we were so close too. White and March would have been proud. Simultaneous breaking of P and T discreet symmetries........been trying to warp spacetime ever since.

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269074#msg1269074

Still looking for magic dielectric to produce thrust based on earliest tests at Eagleworks (before they learned how to control the bandwidth) with unreported Q, with unreported numerical results, conducted at a much higher frequency (way off scale to the right to their S12 plots and their COMSOL Finite Element results ?).

A magic dielectric material not identified in the text of the Eagleworks report, was thouhgt initially to be Teflon (PTFE) then it was suggested to be ceramic, and now thanks to notsosureofit we know to be PE based on the small print of a figure ?

Hanging your hopes on PE (polyethylene) providing thrust somehow, based on a test when Eagleworks did not even have COMSOL Finite Element predictions at what frequencies to expect resonance?

Wouldn't it make more sense to base such hopes on at least a S12 plot?

Ignoring all other data that shows the response to Q and resonance related?

Ignoring the information from wembley that Shawyer no longer uses any dielectric?

And what makes you hope that Polyethylene (the same plastic used to make garbage bags) can produce thrust?

Well the theory has to fit the experiment. They clearly said the dielectric was important. It isn't magic. Someone has to figure it out.

So, rather than examine the experimental numerical data of all the tests in the USA, UK and China, the emphasis should be on a statement on a several-pages long report?

And that little statement -all words, no numerical data- should be interpreted as telling us that Polyethylene (the plastic used for garbage bags) being the key to the Magic Kingdom?

(But for the Cannae device it is Teflon, and for Shawyer now -according to wembley - is nothing -no dielectric)

Yeah pretty much. Teflon and PE are both dielectrics. And Wembley is a reporter or had access to a reporter or something, I don't remember, but what he said could be bad info. Now those Nasa fellers said the dielectric was important, so I'm not gonna discount what they reported. Gotta make the theory fit the experiment. Not to mention you can get measured thrust for artifact effects too, without dielectric.
Title: Re: EM Drive Developments
Post by: SteveKelsey on 10/19/2014 04:38 pm
Please forgive an idle speculation on a Sunday evening from the peanut gallery.

Whilst I have been enjoying the impressive display of skill by the math samurai I have a question I have not seen sliced and diced yet. If the local model of inertia is preferred, could those that propose it please explain to this ignoramus how the gravinertial effects of the universe is switched off? I am not aware of any distance limit proposed by GR or quantum mechanics. Sure for any field the inverse square law seems to apply, but there is no limit beyond which the effect is zero. c limits the timing of a reaction to an action, but it does not eliminate the reaction.

Genuine question, because the local inertia model has to explain how the cosmos is switched off if it is to be taken seriously.

Edited to correct typo
Title: Re: EM Drive Developments
Post by: aero on 10/19/2014 04:43 pm
HI all,
I 've been revisiting my estimate for the dimensions of the Brady cavity and have been having second thoughts. Would a few of you take a look at the photograph and make an estimate of the dimensions. There isn't much to use as a scale but maybe you can find something. I used the cross section of the support and called it 1.5 inches but parallax interferes. I read from the report that the chamber is 36 x 30 inches, and an outside photo of it shows it to be 36 inches long and 30 inches wide. That is, longer than it is wide. Maybe that information could make a better scaling. Anyway, we need more eyes on this than just mine.
aero

P.S. Are there any photos of the device other than Figure 7 and Figure 15 of the report?

https://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum (https://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum)

Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 05:01 pm
HI all,
I 've been revisiting my estimate for the dimensions of the Brady cavity and have been having second thoughts. Would a few of you take a look at the photograph and make an estimate of the dimensions. There isn't much to use as a scale but maybe you can find something. I used the cross section of the support and called it 1.5 inches but parallax interferes. I read from the report that the chamber is 36 x 30 inches, and an outside photo of it shows it to be 36 inches long and 30 inches wide. That is, longer than it is wide. Maybe that information could make a better scaling. Anyway, we need more eyes on this than just mine.
aero

P.S. Are there any photos of the device other than Figure 7 and Figure 15 of the report?

https://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum (https://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-Pendulum)

1) There is also Fig. 17

2) This is something where JohnFornaro and AutoCAD could really help
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 05:12 pm
Please forgive an idle speculation on a Sunday evening from the peanut gallery.

Whilst I have been enjoying the impressive display of skill by the math samurai I have a question I have not seen sliced and diced yet. If the local model of inertia is preferred, could those that propose it please explain to this ignoramus how the gravinertial effects of the universe is switched off? I am not aware of any distance limit proposed by GR or quantum mechanics. Sure for any field the inverse square law seems to apply, but there is no limit beyond which the effect is zero. c limits the timing of a reaction to an action, but it does not eliminate the reaction.

Genuine question, because the local inertia model has to explain how the cosmos is switched off if it is to be taken seriously.

Edited to correct typo

Although the question is probably directed to frobnicat, here is an attempt at answering it:

1) As to Prof. McCulloch's theory, his contact info in the UK: https://www.blogger.com/profile/00985573443686082382

2) As stated by John von Neumann, the business of science is to make mathematical models.  These mathematical models are expected to predict physical effects.  The mathematical theory rises and falls based on its success or failure to make those mathematical predictions.  The emphasis should be on mathematical description of the experiments first, and predictions as the next step.

3) What is inside the cupric hollow EM Drive cavities when they operate ? The answer is clear: photons at microwave frequencies.  Photons are both particle and wave and describable by Quantum Mechanics.  They are not Classical Mechanics particles.  Still conservation of momentum, conservation of energy and other principles apply to this EM Drive.  It is not clear that gravity should pertain to this physical effect.  To this date we use Quantum Mechanics as the most successful theory ever in mathematically predicting nature, yet, its interpretation is still as fraught with difficulties as it was 100 years ago.  Engineers and Scientists calculate and are very happy with the mathematical theory of Quantum Mechanics, without worrying about issues that philosophers worry about like "Many Worlds Interpretations" etc etc.

The questions are:

A) are the measured thrust forces an experimental artifact or a genuine thrust force?

B) if the measured thrust force is not an experimental artifact, is it just causing a rotation of the drive around its center of mass or is it producing a linear acceleration of the center of mass?
Title: Re: EM Drive Developments
Post by: SteveKelsey on 10/19/2014 05:50 pm


1) As to Prof. McCulloch's theory I propose that you direct the question to him directly.  You can find his contact info in the UK here:  https://www.blogger.com/profile/00985573443686082382

Thank you Dr Rodal, I am grateful for the link.


2) As stated by John von Neumann, the business of science is to make mathematical models.  These mathematical models are expected to predict physical effects.  The mathematical theory rises and falls based on its success or failure to make those mathematical predictions.  The emphasis should be on mathematical description of the experiments first, and predictions as the next step.


Agreed. John von Neumann is a personal hero of mine. However, the analysis has to be correctly framed or the math, even where immaculate, will deliver a false result. Goatguy would derive a more satisfactory answer if he characterised Woodwards thruster as part of an open system. He prefers not to and get an over unity result, as would a transistor if you ignored the power supply.


3) What is inside the cupric hollow EM Drive cavities when they operate ? The answer is clear: photons at microwave frequencies.  Photons are both particle and wave and describable by Quantum Mechanics.  They are not Classical Mechanics particles.  Still conservation of momentum, conservation of energy and other principles apply to this EM Drive.  It is not clear at all that gravity should pertain to this physical effect.  To this date we use Quantum Mechanics as the most successful theory ever in mathematically predicting nature, yet, its interpretation is still as fraught with difficulties as it was 100 years ago.  Engineers and Scientists calculate and are very happy with the mathematical theory of Quantum Mechanics, without worrying about issues that philosophers worry about like "Many Worlds Interpretations" etc etc.

Are you proposing that the inside of the device is isolated from the universe? If so how. Please don't bother to answer if you find the question trivial, I won't be offended and I do not want to distract you. Silence is a powerful message : )


The questions are:

A) are the measured thrust forces an experimental artifact or a genuine thrust force?

B) if the measured thrust force is not an experimental artifact, is it just causing a rotation of the drive around its center of mass or is it producing a linear acceleration of the center of mass?

Agreed, and thank you for your contributions to this fascinating thread.

Title: Re: EM Drive Developments
Post by: Mulletron on 10/19/2014 05:50 pm
Please forgive an idle speculation on a Sunday evening from the peanut gallery.

Whilst I have been enjoying the impressive display of skill by the math samurai I have a question I have not seen sliced and diced yet. If the local model of inertia is preferred, could those that propose it please explain to this ignoramus how the gravinertial effects of the universe is switched off? I am not aware of any distance limit proposed by GR or quantum mechanics. Sure for any field the inverse square law seems to apply, but there is no limit beyond which the effect is zero. c limits the timing of a reaction to an action, but it does not eliminate the reaction.

Genuine question, because the local inertia model has to explain how the cosmos is switched off if it is to be taken seriously.

Edited to correct typo

We really started ripping into inertia back around page 80. Oh what a journey that was....I probably got started in on my brain tumor from that. Eventually we arrived at MiHsC as the most informed (modern) and most likely correct theory of inertia. We looked at A LOT of different theories of inertia. Go back to where we were trying to categorize inertia theories by intrinsic/extrinsic.

On the topic of math. I prefer to start with the universe I can see and then try to explain it with math, not the other way around.......experiment and reality trumps math.
Title: Re: EM Drive Developments
Post by: aero on 10/19/2014 06:00 pm
I am confused.

What is the thrust per watt of photon energy for an ideal photon rocket?

Is it energy mass of all the photons times c?
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 06:09 pm
Quote
3) What is inside the cupric hollow EM Drive cavities when they operate ? The answer is clear: photons at microwave frequencies.  Photons are both particle and wave and describable by Quantum Mechanics.  They are not Classical Mechanics particles.  Still conservation of momentum, conservation of energy and other principles apply to this EM Drive.  It is not clear at all that gravity should pertain to this physical effect.  To this date we use Quantum Mechanics as the most successful theory ever in mathematically predicting nature, yet, its interpretation is still as fraught with difficulties as it was 100 years ago.  Engineers and Scientists calculate and are very happy with the mathematical theory of Quantum Mechanics, without worrying about issues that philosophers worry about like "Many Worlds Interpretations" etc etc.

Are you proposing that the inside of the device is isolated from the universe? If so how. Please don't bother to answer if you find the question trivial, I won't be offended and I do not want to distract you. Silence is a powerful message : )

...
We know that the electric field inside the cavity is confined to the cavity as in a Faraday cage.  Any slowly varying component to the magnetic field can escape the cavity.  Gravity acts inside the cavity just as it does outside the cavity, the cavity walls do not provide any shielding against gravity but it is not clear why gravity should play a role on the behavior of the microwave photons inside the cavity.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/19/2014 06:32 pm
I am confused.

What is the thrust per watt of photon energy for an ideal photon rocket?

Is it energy mass of all the photons times c?

For a photon rocket thrust(Newtons)/power(Watts) is 1/c. That is a best case for a perfectly collimated beam : diffraction limit can slightly lower that upper bound (that is if the size of emitter is not many times greater than wavelength), and practical aspects obviously can only limit more this theoretical bound, limited efficiency in energy to photon conversion for instance.

Since thrust (force) is kg m/s impulses per second and Watts is Joules per second, the same ratio is correct as per 
momentum(kg m/s)/energy(Joules) = 1/c

That is exactly the definition of momentum for a photon : p = E/c. This is from there that thrust/power=1/c is derived. Note that frequency (and reciprocally wavelength) don't play any role in that. Beaming perfectly collimated photons with perfect efficiency gives same thrust for a given power, whether this power is used to generate a lot of low momentum microwave photons per second, or a few gamma rays photons of high momentum per second.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 06:51 pm
I am confused.

What is the thrust per watt of photon energy for an ideal photon rocket?

Is it energy mass of all the photons times c?
the thrust of a photon rocket is

F= N * (photon momentum) =  N * h * f / c

where

N = number of photons per unit time
h = Plank constant
f = photon frequency
c = speed of light

Although somebody in this thread keeps writing that photons do not have mass, in the relativistic sense, and in the sense that engineers and scientists use Quantum Mechanics to make everyday calculations, one can use relativistic mass and energy equivalence to calculate the mass flow rate.  E = m * c ^2, therefore  m = E/ (c^2)



photon speed = c

photon energy = h *  f

photon mass =  h *  f / c^2

photon momentum = h *  f / c



mass flow rate:

mdot = N * h * f / c^2

Therefore

(with

g = standard acceleration of gravity = 9.80665 m/ s^2

c= speed of light in vacuum = 299 792 458 m / s
)

Isp = F /( g* mdot )= c / g = 3.06 * 10^7 s

Specific Thrust = Thrust per total photon power= F /( N * h * f)= 1 / c = 3.336 * 10 ^ (-9) s/m

where

total photon power = N * (photon energy) =  N * h * f


Title: Re: EM Drive Developments
Post by: aero on 10/19/2014 07:10 pm
I am confused.

What is the thrust per watt of photon energy for an ideal photon rocket?

Is it energy mass of all the photons times c?

For a photon rocket thrust(Newtons)/power(Watts) is 1/c. That is a best case for a perfectly collimated beam : diffraction limit can slightly lower that upper bound (that is if the size of emitter is not many times greater than wavelength), and practical aspects obviously can only limit more this theoretical bound, limited efficiency in energy to photon conversion for instance.

Since thrust (force) is kg m/s impulses per second and Watts is Joules per second, the same ratio is correct as per 
momentum(kg m/s)/energy(Joules) = 1/c

That is exactly the definition of momentum for a photon : p = E/c. This is from there that thrust/power=1/c is derived. Note that frequency (and reciprocally wavelength) don't play any role in that. Beaming perfectly collimated photons with perfect efficiency gives same thrust for a given power, whether this power is used to generate a lot of low momentum microwave photons per second, or a few gamma rays photons of high momentum per second.

Ok, thanks. That gives nano-N/watt = 1e9/c =~3.334 nano-N/watt
So if the Coefficient Of Performance, COP is (thrust/watt)/ideal rocket thrust/watt we have

Experiment                  COP
  "Shawyer (2008) a"        5643.2
  "Shawyer (2008) b"        64155.6
    "Juan (2012) TE011 a"   64155.6
    "Juan (2012) TE012 b"   94434.6
    "Brady et al. (2014) a"   1617.8
    "Brady et al. (2014) b"   899.4
  "Brady et al. (2014) c"   6387.9

It is interesting that Shawyer b" and Jaun a" are exactly the same. (Because the thrust in the data table is the same, as is power.) Maybe that data entry should be double checked.

And that does make Brady b" stand out as an outlier.

Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 07:33 pm
Attention to new blog page by Prof. McCulloch with a revised chart based on wavelengths and analogies to the reason for a force on the EM Drive:


http://physicsfromtheedge.blogspot.it/2014/10/emdrive-mihsc-dream-of-horizon-physics.html
Title: Re: EM Drive Developments
Post by: frobnicat on 10/19/2014 07:46 pm

Specific Thrust = Thrust per total photon energy = F /( N * h * f)= 1 / c = 3.336 * 10 ^ (-9) s/m

If I may : this mixing of energy and power is confusing. <<N is the photon number flux  (photon number per unit time)>> and F is the "momentum flux" number of momenta (of a photon) per second. Formula is correct but describing the power (energy flux) as "total energy" is misleading.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 08:00 pm

Specific Thrust = Thrust per total photon energy = F /( N * h * f)= 1 / c = 3.336 * 10 ^ (-9) s/m

If I may : this mixing of energy and power is confusing. <<N is the photon number flux  (photon number per unit time)>> and F is the "momentum flux" number of momenta (of a photon) per second. Formula is correct but describing the power (energy flux) as "total energy" is misleading.
Yes you may.  I fix't, it reads now "Thrust per total photon power."  Thks from me.
My friend JohnFornaro will provide you with a financial reward for catching this wording error. You have to choose door #1, door #2, or door #3.  There is a goat behind one of the doors, nothing behind another one and a financial reward behind another one.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/19/2014 08:15 pm
Attention to new blog page by Prof. McCulloch with a revised chart based on wavelengths and analogies to the reason for a force on the EM Drive:


http://physicsfromtheedge.blogspot.it/2014/10/emdrive-mihsc-dream-of-horizon-physics.html
Well that certainly is physics from the edge. Godspeed.
Title: Re: EM Drive Developments
Post by: aero on 10/19/2014 08:16 pm
Still toying with numbers. I divided the COP I posted previously by Q and got this:

                Experiment      COP          COP/Q
    "Shawyer (2008) a"       5,643     0.96
    "Shawyer (2008) b"      64,156     1.43
    "Juan (2012) TE011"    64,156     2.00
    "Juan (2012) TE012"    94,435     1.89
    "Brady et al. (2014) a"    1,618     0.22
    "Brady et al. (2014) b"    899         0.05
  "Brady et al. (2014) c"    6,388     0.29

I don't know that it has any meaning but now at least the number values are near the ideal photon rocket thrust. That is, the thrust of an ideal photon rocket using the stored energy of the cavity/second comes close to the experimentally derived thrusts.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 08:32 pm
Still toying with numbers. I divided the COP I posted previously by Q and got this:

                Experiment      COP          COP/Q
    "Shawyer (2008) a"       5,643     0.96
    "Shawyer (2008) b"      64,156     1.43
    "Juan (2012) TE011"    64,156     2.00
    "Juan (2012) TE012"    94,435     1.89
    "Brady et al. (2014) a"    1,618     0.22
    "Brady et al. (2014) b"    899         0.05
  "Brady et al. (2014) c"    6,388     0.29

I don't know that it has any meaning but now at least the number values are near the ideal photon rocket thrust. That is, the thrust of an ideal photon rocket using the stored energy of the cavity/second comes close to the experimentally derived thrusts.

Taking into account the frequency drift and bandwidth issues that the researchers have tuning the device under resonance, with concomitant drift in Q (which therefore cannot be a constant during the measurements) these results are quite interesting!

Perhaps we need some more frobnicating , including  re-running the formulas with the updated geometry (see http://physicsfromtheedge.blogspot.it/2014/10/emdrive-mihsc-dream-of-horizon-physics.html) and allowing for Sqrt[ 1/big^2 + 1/L^2] and perhaps all the other square roots as well.   Also using the new formulas taking into account wavelength:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1272925#msg1272925


Also frobnicating with the photon rocket analogy...
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/19/2014 09:43 pm
Couple things:
Won't get back to the lab til monday for measurements from picture
Both end plates have something else going on.  Looks likr the top one has a tuning plate(?) of some kind, not motorized
Why the extra plate below the bottom, can't see in pic

Found another paper that was bothering me in the piles behind the desk
"Ionization instabilities and resonant acoustic modes", Physics of Plasmas, V8, N0.11, p.5018

It was concerned w/ the coupling of ions w/ dust particles.  Reminds me of RF w/ axions  (Ya, I'm still chasing the axion connection) no cavities involved, but "It is found that an unstable dust-acoustic mode of nonzero real frequency can be generated via a resonance phenomenon."  ... "As the charge on dust particles exceeds a threshold, multiple low-frequency modes with large growth rates are excited suddenly."

I just had to throw that in cuz I finally found the d**m thing !  (You youngsters can play w/ it for now)

Ok, so in practical terms it means you can (theoretically)induce feedback into the coupling constant if you can set up the dispersion relations properly.

Got a couple minutes to myself, so I thought I'd throw out a bit of rationalization as to why I wanted to find the above mentioned paper (there is probably much better stuff out there for them what's got access)

Anywho, those trying to detect axions look at the interaction as a 3 legged Feynman loop in the presence of a magnetic field, etc.

I think of an interaction between the energy of the cavity photons and momentum transfer to some barely interacting fluid (?, dark matter, ether, etc) as a 4 legged Feynman loop.  It occurred to me that I had seen something analogous to that before, hence the referenced paper (once I found it)

An analogy only, of course, but expressed as a resonant interaction between weakly interacting fields.

Now, the dispersion relation for the axions (?, etc) is unknown(?) but the relation for cavity photons is at least suseptable to some control, for instance, by changing the shape of the cavity, I think.

One thing, the hint is there that the cavity might be exhibiting parametric conversion of some of the photon energy under these circumstances, but there was no effort to look for the presence of other frequencies as far as I know.

Still a long way from numerical calculations.  Thanks for your patience.

Title: Re: EM Drive Developments
Post by: aero on 10/19/2014 09:53 pm
OK - I took out all possible sources of loss and inefficiency by simply replacing the actual measured trust with Prof. M's new formula predicted values.

                                                            Formula thrust
    Experiment                  COP    COP/Q   COP/Q
  "Shawyer (2008) a"    5,643     0.96     0.44
  "Shawyer (2008) b"    64,156     1.43     0.82
  "Juan (2012) TE011"    64,156     2.00     0.82
  "Juan (2012) TE012"    94,435     1.89     0.82
  "Brady et al. (2014) a"    1,618     0.22     0.46
  "Brady et al. (2014) b"    899     0.05     0.46
  "Brady et al. (2014) c"    6,388     0.29     0.46

Now the values are all geometry because Q is multiplied the formula and divided out.  The values though are getting into the range of what a COP based on an ideal photon rocket should be. I could factor cosine losses into the thrust formula but that's a lot of trouble for little benefit.

This formula says to me that what is wanted is a big cavity with the ratio (w_big/w_small) large, and height/length, (s) large. Height/length, (s) large is the new factor in Prof. M's latest formula and s is the variable name he uses.

 It seems that current tech could deal with that but of course the larger the cavity is, the heavier it is so the T/W ratio suffers at some point.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 09:57 pm
OK - I took out all possible sources of loss and inefficiency by simply replacing the actual measured trust with Prof. M's new formula predicted values.

                                                            Formula thrust
    Experiment                  COP    COP/Q   COP/Q
  "Shawyer (2008) a"    5,643     0.96     0.44
  "Shawyer (2008) b"    64,156     1.43     0.82
  "Juan (2012) TE011"    64,156     2.00     0.82
  "Juan (2012) TE012"    94,435     1.89     0.82
  "Brady et al. (2014) a"    1,618     0.22     0.46
  "Brady et al. (2014) b"    899     0.05     0.46
  "Brady et al. (2014) c"    6,388     0.29     0.46

Now the values are all geometry because Q is multiplied the formula and divided out.  The values though are getting into the range of what a COP based on an ideal photon rocket should be. I could factor cosine losses into the thrust formula but that's a lot of trouble for little benefit.

This formula says to me that what is wanted is a big cavity with the ratio (w_big/w_small) large, and height/length, (s) large. Height/length, (s) large is the new factor in Prof. M's latest formula and s is the variable name he uses.

 It seems that current tech could deal with that but of course the larger the cavity is, the heavier it is so the T/W ratio suffers at some point.

Very interesting.   On this topic, have people commented on this paper

Photonic Laser Propulsion (PLP): Photon Propulsion Using an Active Resonant Optical Cavity ?

http://arc.aiaa.org/doi/abs/10.2514/6.2007-6131

He claims to have measured 35 microNewtons thrust at 1.7 watts with propellant less photon rocket amplification in an optical cavity

This is a much higher thrust/power input than normal photon rockets and even superior to NASA Eagleworks truncated cone experiments



Title: Re: EM Drive Developments
Post by: frobnicat on 10/19/2014 10:10 pm
Still toying with numbers. I divided the COP I posted previously by Q and got this:

                Experiment      COP          COP/Q
    "Shawyer (2008) a"       5,643     0.96
    "Shawyer (2008) b"      64,156     1.43
    "Juan (2012) TE011"    64,156     2.00
    "Juan (2012) TE012"    94,435     1.89
    "Brady et al. (2014) a"    1,618     0.22
    "Brady et al. (2014) b"    899         0.05
  "Brady et al. (2014) c"    6,388     0.29

I don't know that it has any meaning but now at least the number values are near the ideal photon rocket thrust. That is, the thrust of an ideal photon rocket using the stored energy of the cavity/second comes close to the experimentally derived thrusts.

Yes, from my automated search most formulas that fit data without big constant magnitude fudge factor show  F/P = 1/c * Q * geometric_factor. In the geometric factor there is the wavelength (of the driving frequency), the small  end and big end size. All those sizes are in the same ballpark and combined in the geometric_factor which is dimensionless => geometric_factor is around one unit. That is geometric_factor=COP/Q, as what you define as COP=(claimed thrust/power)/(perfect photon rocket/power) = (1/c*Q*geometric_factor)/(1/c) = Q*geometric_factor.

If we discard the outlier Brady b, and ignore the geometric_factor for the moment (while data shows a statistically strong linear relation F/P = 1/c Q times something, this looks more fragile when it comes to pinning down the exact expression of this something in function of remaining parameters)... well, so , if we consider as a simplification geometric_factor=1, that is something that pushes simply as F/P = 1/c * Q  then it is like the force between two plates defining a cavity where photons bounce back and forth an average Q number of times before being lost or absorbed.

Note that it would be the force between two plates, that is to get useful work (not more than what was invested for photons, but better than for a photon rocket) from this "photon pressure buildup" you have to get a fixed plate and a moving plate. If the two plates are comoving because they are part of the same rigid object then it is useless. It's like pressure : more pressure gives more acceleration to the two parts of a piston, but more pressure in a rigid device (no parts moving relative to each others) gives nothing useful in term of displacements. If there is a leak in the walls of a rigid device then more pressure means more thrust, but this is simply letting some more momentum escape, more action => more reaction : this is a classical rocket open system, and the efficiency is given by the speed of ejection. If photons escape at a certain rate, then we are losing energy at a certain rate, that is we have to "lose" a certain power, and the thrust/power is again 1/c, regardless of photons coming from a highly resonant cavity or from a mere tungsten filament.

For the variable length high Q "cavity" space applications : some musings by me (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1258978#msg1258978).

More later as per Rodal answer to this nifty toy table : we must seriously address the question of the role of resonance and Q in a cavity, and first I feel an urgent need to clarify my (and maybe the general audience's) understanding for those mundane mechanisms in usual classical setting, before tuning for more exotic storylines.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/19/2014 10:17 pm
Quote from: Steve Kelsey
Please forgive an idle speculation on a Sunday evening from the peanut gallery.
Quote

Thanks.  I was really gettin'  kinda full, all by myself in that there gallery.
Title: Re: EM Drive Developments
Post by: aero on 10/19/2014 10:22 pm
@frobnicat

Note that Prof. M's revised thrust formula,

F = PQs/c * ((1/w_big)-(1/w_small))     (2),

he has replaced the frequency term with c/s, where he is using the length of the cavity as s. That of course predicts a higher value for thrust. But with the revised cavity dimensions, he needed a larger predicted value to come close to the experimental results.

And we do need better estimates of Brady's cavity dimensions as a minimum.

aero.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/19/2014 10:23 pm
Quote
we must seriously address the question of the role of resonance and Q in a cavity
Indeed!
We need microwave sources that are stable < 0.1Hz
and tuneable.
Title: Re: EM Drive Developments
Post by: aero on 10/19/2014 10:43 pm
OK - I took out all possible sources of loss and inefficiency by simply replacing the actual measured trust with Prof. M's new formula predicted values.

                                                            Formula thrust
    Experiment                  COP    COP/Q   COP/Q
  "Shawyer (2008) a"    5,643     0.96     0.44
  "Shawyer (2008) b"    64,156     1.43     0.82
  "Juan (2012) TE011"    64,156     2.00     0.82
  "Juan (2012) TE012"    94,435     1.89     0.82
  "Brady et al. (2014) a"    1,618     0.22     0.46
  "Brady et al. (2014) b"    899     0.05     0.46
  "Brady et al. (2014) c"    6,388     0.29     0.46

Now the values are all geometry because Q is multiplied the formula and divided out.  The values though are getting into the range of what a COP based on an ideal photon rocket should be. I could factor cosine losses into the thrust formula but that's a lot of trouble for little benefit.

This formula says to me that what is wanted is a big cavity with the ratio (w_big/w_small) large, and height/length, (s) large. Height/length, (s) large is the new factor in Prof. M's latest formula and s is the variable name he uses.

 It seems that current tech could deal with that but of course the larger the cavity is, the heavier it is so the T/W ratio suffers at some point.

Very interesting.   On this topic, have people commented on this paper

Photonic Laser Propulsion (PLP): Photon Propulsion Using an Active Resonant Optical Cavity ?

http://arc.aiaa.org/doi/abs/10.2514/6.2007-6131

He claims to have measured 35 microNewtons thrust at 1.7 watts with propellant less photon rocket amplification in an optical cavity

This is a much higher thrust/power input than normal photon rockets and even superior to NASA Eagleworks truncated cone experiments

Does anyone have access to this full paper?

From the abstract, It looks like his resonant cavity has a Q of 3000. At 35 muN thrust, 1.7 watts, and frobnicat's simplified rule of thumb,  F/P = 1/c * Q predicts F = 17. muN . Only missing a factor of 2.

I'd say that's close enough to add a constant factor of 2 as a possible choice in your formula search. Have we exceeded a million equation search yet?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/19/2014 10:48 pm
Respect to all the theory.
Shirley you guys can come up with an experiment to determine reality?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/19/2014 10:50 pm
I have my sheets of copper and a dismantled microwave oven at the ready!
Title: Re: EM Drive Developments
Post by: frobnicat on 10/19/2014 10:53 pm
Taking into account the frequency drift and bandwidth issues that the researchers have tuning the device under resonance, with concomitant drift in Q (which therefore cannot be a constant during the measurements) these results are quite interesting!
More on that later please, as relation of resonance with Q not clear to me (higher Q => narrower bandwidth not the point, that's perfectly clear). Needs time to think of a clear enough way to express what's not clear, that's difficult.

Quote
Perhaps we need some more frobnicating , including  re-running the formulas with the updated geometry (see http://physicsfromtheedge.blogspot.it/2014/10/emdrive-mihsc-dream-of-horizon-physics.html) and allowing for Sqrt[ 1/big^2 + 1/L^2] and perhaps all the other square roots as well.   Also using the new formulas taking into account wavelength:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1272925#msg1272925


Also frobnicating with the photon rocket analogy...

You know the definition of what it means to frobnicate (http://dictionary.reference.com/browse/frobnicate), don't you ? Been warned : don't expect too much of frobnicating, or of frobnicat for that matter.

I can release source code for anyone with a standard C compiler at hand, but there also be warned than in its present version it is risky (risky like dancing with a werewolf atop a cliff) to make modifications on it, unless you are me (are you ?) or a veteran programmer with quite a few hours to kill. Why I haven't proposed that before. Time permitting, a refactoring could help make it more useable.

Easiest way would be someone fills in data in format like that

#define Nrec 7
t_data data_in[Nrec] =
{
    //                                 w_big  w_small  lambda      Q     power   force
    {"Shawyer (2008) a",        1.0 ,  16    ,  8    , C/2.45  ,  5900 ,  850   , 16       },
    {"Shawyer (2008) b",        1.0 ,  28    ,  4    , C/2.45  , 45000 , 1000   , 214      },
    {"Juan (2012) TE011",       1.0 ,  28    ,  4    , C/2.5   , 32000 , 1000   , 214      },
    {"Juan (2012) TE012",       1.0 ,  28    ,  4    , C/2.45  , 50000 , 1000   , 315      },
    {"Brady et al. (2014) a",   1.0 ,  24.75 , 16.5  , C/1.933 ,  7320 ,   16.9 ,   0.0912 },
    {"Brady et al. (2014) b",   1.0 ,  24.75 , 16.5  , C/1.937 , 18100 ,   16.7 ,   0.0501 },
    {"Brady et al. (2014) c",   1.0 ,  24.75 , 16.5  , C/1.88  , 22000 ,    2.6 ,   0.0554 },
};


and specify the units of other fields (say, introducing a new column length => that's centimetres  :D)
The column full of ones are weights for the least square sum, but it is not actually used yet (could be in the future)
Oh, and remember I'm French, I don't know what is an inch or a foot.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/19/2014 10:55 pm
Quick run with the magnetron:
Need to take the cat to the vet.
No anomalous force detected.
Minor fires extinguished.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/19/2014 10:59 pm
The bloody thing you get out of a microwave oven is a dangerous bloody thing.
Please, people don't fool around with these things.
Title: Re: EM Drive Developments
Post by: Rodal on 10/19/2014 11:13 pm
I have my sheets of copper and a dismantled microwave oven at the ready!
All kidding aside, it is important that the inner cavity walls made out of a shiny highly conductive material like copper, in order to minimize losses and maximize Q.  The inner surface should be smooth copper like a mirror.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/19/2014 11:53 pm

Very interesting.   On this topic, have people commented on this paper

Photonic Laser Propulsion (PLP): Photon Propulsion Using an Active Resonant Optical Cavity ?

http://arc.aiaa.org/doi/abs/10.2514/6.2007-6131

He claims to have measured 35 microNewtons thrust at 1.7 watts with propellant less photon rocket amplification in an optical cavity

This is a much higher thrust/power input than normal photon rockets and even superior to NASA Eagleworks truncated cone experiments

Does anyone have access to this full paper?

From the abstract, It looks like his resonant cavity has a Q of 3000. At 35 muN thrust, 1.7 watts, and frobnicat's simplified rule of thumb,  F/P = 1/c * Q predicts F = 17. muN . Only missing a factor of 2.

I'd say that's close enough to add a constant factor of 2 as a possible choice in your formula search. Have we exceeded a million equation search yet?

Yeah, I probably messed up with a factor of 2 in my previous post. This is just, you know, frobnicating. Seriously : a bounce gives twice the momentum of the photon so, here is the 2 factor probably. Now, if someone comes with another 2 factor (4 times what I told you so learnedly) I could still argue the subtle nuance of the chances being absorbed on one single pass or on a back and forth.

Anyway, this paper is, like, exactly what I said (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1273591#msg1273591)  ;D
From the summary (don't have access to full paper, would be interested) :
<<...trapping or bouncing photons between two high reflectance mirrors located separately in spacecraft platforms ... the laser cavity is directly formed between a pair of space platforms. >>

Sorry this is not exciting fringe science, this is action/reaction all the most classical. It is interesting, it deserves consideration in advanced concepts, but this is not about a box "self accelerating" in deep space. This is two spaceships pushing on each others at some distance, gaining more distance, and more relative speed. This is a cavity with two plates that are not part of one single rigid body. No fancy theory needed, no problem with momentum conservation, no problemo in using the same photon's momentum 3000 times, no problem with energy conservation. As the relative speed increases, the photons get more and more redshifted at each bounce until it gets significant. So expect a decreasing efficiency as approaching c/3000 = 100 km/s relative speeds. If the "amplification factor" of 3000 were to be raised to 3000000 then the efficiency would start to suffer at 100m/s relative speeds... (give or take a factor 2  ::)

This is not photon rocket or a "drive", this is a pusher beam. Could be applicable to beamed propulsion. Would love to know the details in the full paper : would work up to what distances ? Probably bounded by diffraction limit.

One relevant aspect though is that the cavity "becomes robust" because the "optical gain medium is within the cavity". This was advanced by someone here (don't recall who and when) that it would be a good idea to use the cavity itself as part of the microwave generator to avoid problems of fine tuning (for EMdrives designs).

<<the reason for this (resonance robustness) is that the optical gain medium is within the optical cavity, and the cavity is operated in multifrequency oscillation.>>
multifrequency oscillation : what's that ??
Title: Re: EM Drive Developments
Post by: frobnicat on 10/20/2014 12:19 am
Have we exceeded a million equation search yet?

No but 21769 is already quite a lot. The data set is sparse and with some uncertainties : the risk is overfitting. Scanning on more than 15 bits (32768 combinations) worth of explanation could easily bring up more perfect formula for the specific available data but with less generalisation power : worse at predicting next data points to come. Need more data points before it's worth looking at much more formulas. Not a problem of computing power, not before reaching many billions of formulas.

At this stage with 7 data points, from a "phenomenological theoretically agnostic" point of view, simpler is better, and there is not that much simple equations.

Note : the number of combinations of exponents and added terms were 94 millions but of those only 21769 unique representations (discarding equivalents) made sense in dimensional analysis (kg m s).


Title: Re: EM Drive Developments
Post by: aero on 10/20/2014 12:43 am
Ok, that's good. Basically anything sensible we come up with can be computed then for this small data set.

Yes. I looked at some articles on PSP, its just another way of doing beamed propulsion. Since the photons within the resonance cavity (between the mirrors) actually are pushing, all of them count to give thrust. In the EM drive case, it seems that all of the photons are counting to give thrust but they are not leaving the cavity of the engine. I guess that is the trick and the problem. How can the momentum of the photons in the cavity be separated from the photons themselves? Momentum departs, photons remain.
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 01:12 am
Have we exceeded a million equation search yet?

No but 21769 is already quite a lot. The data set is sparse and with some uncertainties : the risk is overfitting. Scanning on more than 15 bits (32768 combinations) worth of explanation could easily bring up more perfect formula for the specific available data but with less generalisation power : worse at predicting next data points to come. Need more data points before it's worth looking at much more formulas. Not a problem of computing power, not before reaching many billions of formulas.

At this stage with 7 data points, from a "phenomenological theoretically agnostic" point of view, simpler is better, and there is not that much simple equations.

Note : the number of combinations of exponents and added terms were 94 millions but of those only 21769 unique representations (discarding equivalents) made sense in dimensional analysis (kg m s).

Not quite there yet.  The theoretical geometrical variable for a resonant cavity box is Sqrt[a^-2+L^-2]  and we didn't have square roots of additions allowed, is that right?

Moreover we had a number of formulas very close: [a^-2+L^-2]  and [a^-1+L^-1] 
So the data was telling us we need to allow Sqrt[a^-2+L^-2]

We had these square roots but they are missing the plus sign:

a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1 sqrt(a^-2 L^-2)^-1   1.02   0.58
a^-1 b^-2 L^2  Q^1  P^1  F^-1 c^-1 sqrt(a^-1 L^-1)^-1   1.32   0.58
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/20/2014 01:37 am
The cat is ok btw.
Just slightly singed.
Title: Re: EM Drive Developments
Post by: aero on 10/20/2014 01:49 am
The cat is ok btw.
Just slightly singed.

Glad to hear it.

 I warned you many pages ago to be careful with those things. They are dangerous when not properly shielded. One Kw of microwave power will boil water quickly, and your cat is mostly water. Didn't you read my warning to your cat? Or just show it to him/her - she/he can probably read it.

Just because a cat mouth won't make word sounds doesn't mean their is anything wrong with their hearing or eyesight. If you want your cat to help with your experiments you should teach it sign language.
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 02:12 am
Taking into account the frequency drift and bandwidth issues that the researchers have tuning the device under resonance, with concomitant drift in Q (which therefore cannot be a constant during the measurements) these results are quite interesting!
More on that later please, as relation of resonance with Q not clear to me (higher Q => narrower bandwidth not the point, that's perfectly clear). Needs time to think of a clear enough way to express what's not clear, that's difficult.

The Q value depends on the frequency and mode shape of the resonant cavity, as well as the wall material properties and the geometry.

The Q value for the lowest frequency of a cylindrical resonant cavity  (TM010) is

Q =( Length / skinDepthForResonantFrequency) / (1 + ( 2*Length / InnerDiameter ))

skinDepthForResonantFrequency = 1/Sqrt[Pi*ResonantFrequency*μ*σ]

so,

Q =  Sqrt[Pi*ResonantFrequency*μ*σ]*Length/ (1 + ( 2*Length / InnerDiameter ))

The skinDepth is a function of the frequency and wall material properties: permeability μ and electrical conductivity σ, which can be complex, frequency dependent, and anisotropic functions of field direction. They can also be functions of density, temperature, field strength, and other quantities (they can depend on the electric field and the magnetic field).

Therefore Q is a function of the Length and Diameter of the cylindrical cavity, as well as the frequency, and of the wall material.

The skin depth should be around a couple of micrometers (μm). Therefore the inner wall of the cavity must be carefully plated or polished; otherwise, current flow will be severely perturbed by surface irregularities lowering the cavity Q.


==> so John: there

We do know a lot of things of what's inside these cupric cavities, we know that from the cumulative scientific knowledge that has accumulated since Maxwell's equations and our ability to solve them.  When the researchers provide to us S12 plots, and Q measurements, they are providing us information about the inside of the cavities.

For example, given the geometry, frequencies and the measured Q, we know the following:

1) Both inner surface ends of the truncated cone must have been made out of copper. Otherwise the cavity would not have the correct boundary conditions to be a resonant cavity: it would be a waveguide.  One wouldn't be able to have high Q and resonance if the inner surface of the ends wouldn't be copper.

2) The inner surface of the copper must have been pretty well polished, in order to get Q~50 000, given the calculated skin depths

3) There cannot be any significant irregularities on the inside surface of the truncated cone.

So there "about hummingbirds".  That's the power of science
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/20/2014 03:00 am
Frobnicate (http://dictionary.reference.com/browse/frobnicate)

Thanks for the learn something new every day moment!

I was starting to think you all were a bunch of Aholeholes (http://mentalfloss.com/article/58036/50-words-sound-rude-actually-arent), what with all that math you all are throwing around.

I am under a drawing crunch.  Will get around to attempting dimensions on those other copper cans later this week. 

Maybe someone could illustrate them all sequentially?  There are what, three "models"?  Four?  Highest rez possible, and some scalable diameter.  Plus a short name which I can include on the title block.

I don't know what is an inch or a foot.

Well, there's an easy memnonic for that:

One inch is the difference between an "Oooh", and an "Ahhh".

1) Both inner surface ends of the truncated cone must have been made out of copper. Otherwise the cavity would not have the correct boundary conditions to be a resonant cavity: it would be a waveguide.  One wouldn't be able to have high Q and resonance if the inner surface of the ends wouldn't be copper.

2) The inner surface of the copper must have been pretty well polished, in order to get Q~50 000, given the calculated skin depths

3) There cannot be any significant irregularities on the inside surface of the truncated cone.

1)  So there's copper on the inside of that PCB board?

2)  I'm envisioning polishing on the level of the Hubble's mirrors, not the cursory polish on the devices pictured so far.  Plus, the copper is so thin that it would be ...

3) ... easily deformed, particularly by heating, or bumping into something.

Just observin'.
Title: Re: EM Drive Developments
Post by: aceshigh on 10/20/2014 04:02 am
The cat is ok btw.
Just slightly singed.

good think it was a cat, because gremlins are much more sensitive to microwaves.

I counted 7 seconds
https://www.youtube.com/watch?v=bu6NGUDoi30
Title: Re: EM Drive Developments
Post by: aero on 10/20/2014 04:23 am
Ok, that's good. Basically anything sensible we come up with can be computed then for this small data set.

Yes. I looked at some articles on PSP, its just another way of doing beamed propulsion. Since the photons within the resonance cavity (between the mirrors) actually are pushing, all of them count to give thrust. In the EM drive case, it seems that all of the photons are counting to give thrust but they are not leaving the cavity of the engine. I guess that is the trick and the problem. How can the momentum of the photons in the cavity be separated from the photons themselves? Momentum departs, photons remain.

I've been thinking about the double slit experiment which proves that a single electron passes through both slits. The extension to photons is that a single photon passes through both slits. What if the momentum of the photon passing through the left slit was reflected while the momentum of the right photon was passed through the slit? That replaces our problem of separating the momentum from the photon to one of passing a photon through the copper undetectably.

And since the power is now multiplied by Q there is an appreciable amount of power to remain undetected. But momentum is not power.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/20/2014 08:01 am
Ok I'm aware that I'm the stick in the mud here, but not by virtue of being intentionally obtuse here. I believe I have things in the right perspective. Let me state this another way:

Now you can dump rf energy into a cavity all day long, and that rf cavity is going to eventually absorb (as a function of Q) and re-radiate that energy right back to the universe in which it resides. Given the cavity has a big end and a small end, you have more surface area on the big end in which to radiate heat, giving the illusion of thrust by new science. This isn't new science. I don't need a page long series of equations to characterize this. It is just thermodynamics.

Also it is well known that if an electric current flows through anything, wires, cavity walls, whatever... the result is a perpendicular magnetic field around the conductor. Now pulse that current, you get a pulsating magnetic field.

The NASA test campaign is very telling compared to the other tests, because the NASA tests were low power tests. This allowed them to effectively separate out artifact modes of thrust from the dominant mode of thrust. They concluded, all things considered that the dielectric was important to measured thrust.

If you dump hundreds watts into an empty sealed test article, yep, you're gonna measure some thrust. The thrust you get doesn't need new science to explain.

One can try to get famous by writing page long formulas to explain the obvious, but there is no need.

Empty cavities providing thrust isn't anomalous thrust.
Cavities with dielectric present providing thrust is anomalous thrust. And when you remove the dielectric, the thrust goes away.......that is anomalous.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/20/2014 09:31 am
Ok I'm aware that I'm the stick in the mud here, but not by virtue of being intentionally obtuse here. I believe I have things in the right perspective. Let me state this another way:

Now you can dump rf energy into a cavity all day long, and that rf cavity is going to eventually absorb (as a function of Q) and re-radiate that energy right back to the universe in which it resides. Given the cavity has a big end and a small end, you have more surface area on the big end in which to radiate heat, giving the illusion of thrust by new science. This isn't new science. I don't need a page long series of equations to characterize this. It is just thermodynamics.

Some thrust from asymmetric heat radiation isn't new science, that's correct. But above that qualitative statement, a single equation is relevant nonetheless : for this classical explanation to hold, the device is just a photon rocket => F < P/c   Brady a : power 17W, max classical radiative force 17/3e8 = 56 nN (nano Newtons), much below the claimed thrust of ~90 µN. No need of page long series of equation, but one equation to discard this one classical explanation, in this easy case (at least 2 orders of magnitude off target). And quite a number of equations and computing hours are needed to ascertain an effect as heat radiation thrust when the case is not that clear (Pioneer anomaly...).

Throwing in an equation is better than just words (isn't it dr Rodal ?) but thinking twice about it can't hurt : the  F < P/c upper bound has an implied hypothesis that the radiated heat is just lost in the cold of deep space. Now what if the device is inside a chamber and IR photons are bouncing a few times before being absorbed in the cold walls of the chamber ? Then you have an amplification factor and the upper bound becomes F<q P/c where q is the "quality factor" of bouncing IR photons between device and chamber walls (like the "pusher beam" of the photonic laser propulsion (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1273587#msg1273587) scheme)

Do you find likely that not specially prepared surfaces (outer device and inner chamber walls) could bounce IR photons 300 times before absorbing ? I don't => classical radiative thrust discarded, but than needs a minimum of qualitative and quantitative argumentation.

Quote

Also it is well known that if an electric current flows through anything, wires, cavity walls, whatever... the result is a perpendicular magnetic field around the conductor. Now pulse that current, you get a pulsating magnetic field.

That can't significantly go any deeper than a few µm if the pulses are GHz.
BTW what is the thickness of copper on the PCBs at the ends in Brady et al apparatus ? Guess it's more than 20µm ? Should be a perfect wall for microwaves, for all practical purpose.

Quote
The NASA test campaign is very telling compared to the other tests, because the NASA tests were low power tests. This allowed them to effectively separate out artifact modes of thrust from the dominant mode of thrust. They concluded, all things considered that the dielectric was important to measured thrust.

If you dump hundreds watts into an empty sealed test article, yep, you're gonna measure some thrust. The thrust you get doesn't need new science to explain.

The relative magnitude of thrust you get in those experiments needs either new science or old science with reasonably detailed quantitative explanations as artifacts. Isn't it dr Rodal ?

Quote

One can try to get famous by writing page long formulas to explain the obvious, but there is no need.

Empty cavities providing thrust isn't anomalous thrust.
Cavities with dielectric present providing thrust is anomalous thrust. And when you remove the dielectric, the thrust goes away.......that is anomalous.

Nobody tries to be famous here, we are all already famous enough on some rock scene (otherwise we wouldn't come by here with nicknames). We are here incognito on this family site to advance science, far from our oppressive celebrity

Apart from dr Rodal. But a doctor has and ethic, and can't be motivated by mediocre motives like that.
So doctor : by what I understand you no longer believe the presence of dielectric is significant as
- Brady et al were off resonance target when removing dielectric (dielectric_presence and correct_resonance not tested independently )
- Shawyer no longer uses dielectrics.

Can we reach a consensus whether or not dielectric is significant ?

New physics real effects or old physics artifacts : nothing is obvious, either cases.

Title: Em Drive update
Post by: Chrochne on 10/20/2014 11:15 am
There is a new update about the EmDrive on their official website - emdrive.com

"At the IAC 2014 conference in Toronto, Roger Shawyer stated that 8 sets of test data have now verified EmDrive theory. These data sets resulted from thrust measurements on 7 different thrusters, by 4 independent organisations, in 3 different countries."

You might want to check it. Its from October 2014 there is also one interesting PDF  :).

Title: Re: EM Drive Developments
Post by: Star One on 10/20/2014 11:17 am
Here is the PDF mentioned above.

http://www.emdrive.com/iac2014presentation.pdf
Title: Re: EM Drive Developments
Post by: Mulletron on 10/20/2014 11:23 am
Yes I calculate for between 1-2ghz, the skin depth of copper is 2.1um to 1.46um respectively. That's not the direction I was going. Even with the 4x skin depth recommendation, the copper cavity is way thick enough for skin depth to not be a factor. I don't know how thick it is exactly, but I know it isn't made of copper foil. I acknowledge this and I know I am on shaky ground trying to invoke leaky magnetic influence. IR loss is a given, magnetic induction is not so easy.

Either way, I'm trying to break theories as much as I can. That's science.

I just get bent out of shape when I see new theories for emdrive that try to teach photons new tricks.

I'm trying to explore near field effects in more detail.

Title: Re: EM Drive Developments
Post by: Mulletron on 10/20/2014 12:02 pm
On page 2 of this: http://www.emdrive.com/iac2014presentation.pdf

He makes a point of showing a distinction between thrust (force) and reaction (force). Really tearing into this, and correct me if I got this wrong, the ones that say thrust, are measured from the perspective of the device, and the reaction is where a second object exerts an equal and opposite reaction (force) on the first object providing the thrust (force).

The ones that say thrust all have dielectric in common, and appear reactionless.
The ones that say reaction have no dielectric in common, and are not reactionless.

Designs with dielectric, appear reactionless (postulated to react with the QV).
Designs without dielectric, not reactionless.

This tells me that designs which have no dielectric, would not fly in vacuum, as there is nothing to react against.

The reason I'm saying the above sentence is because photons aren't known to self interact. Set me straight on this sentence, because I am not completely up on 2 photon physics.

Just a side note, a classical rocket in vacuum still works, because the reaction mass is the nozzle itself and its own hot gasses. Hot gas hits the nozzle, the nozzle and gasses provides an equal and opposite reaction.

Edited for grammar/clarity.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/20/2014 12:08 pm
Have we exceeded a million equation search yet?

No but 21769 is already quite a lot. The data set is sparse and with some uncertainties : the risk is overfitting. Scanning on more than 15 bits (32768 combinations) worth of explanation could easily bring up more perfect formula for the specific available data but with less generalisation power : worse at predicting next data points to come. Need more data points before it's worth looking at much more formulas. Not a problem of computing power, not before reaching many billions of formulas.

At this stage with 7 data points, from a "phenomenological theoretically agnostic" point of view, simpler is better, and there is not that much simple equations.

Note : the number of combinations of exponents and added terms were 94 millions but of those only 21769 unique representations (discarding equivalents) made sense in dimensional analysis (kg m s).

Not quite there yet.  The theoretical geometrical variable for a resonant cavity box is Sqrt[a^-2+L^-2]  and we didn't have square roots of additions allowed, is that right?

Moreover we had a number of formulas very close: [a^-2+L^-2]  and [a^-1+L^-1] 
So the data was telling us we need to allow Sqrt[a^-2+L^-2]

We had these square roots but they are missing the plus sign:

a^-2 b^-2 L^2  Q^1  P^1  F^-1 c^-1 sqrt(a^-2 L^-2)^-1   1.02   0.58
a^-1 b^-2 L^2  Q^1  P^1  F^-1 c^-1 sqrt(a^-1 L^-1)^-1   1.32   0.58

Before the latest conference "paper" buries us with a fury of posts :

For the previous data, without Brady b, not yet taking into account other parameters ( L is still the wavlength of driving frequency), sieving only through even powers (except for the added term) on with higher thresholds :


6 entries

Thresholds : mean=2.00   stddev=1.35

 a    b    L    Q    P    F    c                        mean   stddev
---------------------------------------------------------------------

 a    b    L    Q    P    F    c      exterm            mean   stddev
---------------------------------------------------------------------
a^2  b^-2 L^-2 Q^2  P^2  F^-2 c^-2   (a^-2 + b^-2)^-1   1.42   1.34
a^0  b^0  L^2  Q^2  P^2  F^-2 c^-2   (a^-2 + b^-2)^1    1.76   0.93
a^2  b^-2 L^2  Q^2  P^2  F^-2 c^-2   (a^ 2 + b^ 2)^-1   1.42   0.68
a^0  b^-2 L^0  Q^2  P^2  F^-2 c^-2   (a^-2 + L^-2)^-1   1.31   0.77 *
a^-2 b^-2 L^2  Q^2  P^2  F^-2 c^-2   (a^-2 + L^-2)^-1   0.09   1.00 *
a^-2 b^-2 L^2  Q^2  P^2  F^-2 c^-2   (a^ 2 + L^ 2)^1    1.87   0.84 *
a^2  b^-2 L^-2 Q^2  P^2  F^-2 c^-2   (b^-2 + L^-2)^-1   1.23   1.21
a^0  b^0  L^2  Q^2  P^2  F^-2 c^-2   (b^-2 + L^-2)^1    1.95   1.06
a^-2 b^-2 L^2  Q^2  P^2  F^-2 c^-2   (b^ 2 + L^ 2)^1    0.72   1.35
a^2  b^2  L^-2 Q^2  P^2  F^-2 c^-2   |a^-2 - b^-2|^1    1.34   1.25
a^0  b^0  L^2  Q^2  P^2  F^-2 c^-2   |a^-2 - b^-2|^1    1.34   0.60
a^2  b^-2 L^2  Q^2  P^2  F^-2 c^-2   |a^ 2 - b^ 2|^-1   1.84   1.02
a^-2 b^-2 L^2  Q^2  P^2  F^-2 c^-2   |a^-2 - L^-2|^-1   0.79   1.22
a^-2 b^-2 L^2  Q^2  P^2  F^-2 c^-2   |a^ 2 - L^ 2|^1    1.16   0.79
a^2  b^2  L^-2 Q^2  P^2  F^-2 c^-2   |b^-2 - L^-2|^1    0.66   0.62
a^2  b^0  L^0  Q^2  P^2  F^-2 c^-2   |b^-2 - L^-2|^1    1.88   0.88
a^0  b^2  L^0  Q^2  P^2  F^-2 c^-2   |b^-2 - L^-2|^1   -0.57   0.83
a^0  b^0  L^2  Q^2  P^2  F^-2 c^-2   |b^-2 - L^-2|^1    0.65   0.51
a^-2 b^2  L^2  Q^2  P^2  F^-2 c^-2   |b^-2 - L^-2|^1   -1.79   1.19
a^-2 b^-2 L^2  Q^2  P^2  F^-2 c^-2   |b^ 2 - L^ 2|^1   -0.57   0.43
a^0  b^-2 L^0  Q^2  P^2  F^-2 c^-2 sqrt(a^-2 b^-2)^-1   1.59   1.13
a^-2 b^-2 L^2  Q^2  P^2  F^-2 c^-2 sqrt(a^-2 L^-2)^-1   0.98   0.91
a^0  b^-2 L^0  Q^2  P^2  F^-2 c^-2 sqrt(b^-2 L^-2)^-1   0.98   1.26
a^2  b^0  L^2  Q^2  P^2  F^-2 c^-2   (a^-2 * b^-2)^1    1.59   0.80

Checked : 1581201
Validated : 972


There are others (a^ 2 + L^ 2)^1 but that give even worse fits.

Those sqrt(1/x² + 1/y²)  were already scanned for all reasonable formula of the form F = QP/c * term. They are not good fit so haven't showed through the sieve. Will explicitly add sqrt(1/x² + 1/y²) to scan with higher powers for the other terms F Q P and c but doubt this will show up more interesting things, as  F = QP/c * term seems quite robust. Will also try to integrate the new datas on MiHsC ... please be patient, this is only part time !

Title: Re: EM Drive Developments
Post by: frobnicat on 10/20/2014 12:51 pm
Here is the PDF mentioned above.

http://www.emdrive.com/iac2014presentation.pdf

Is there a paper with more details to be published ?
"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?
Title: Re: EM Drive Developments
Post by: Chrochne on 10/20/2014 01:02 pm
Here is the PDF mentioned above.

http://www.emdrive.com/iac2014presentation.pdf

Is there a paper with more details to be published ?
"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?
...

I would be glad, if there are more details. Thats all there is for the update. Perhaps someone in this debate here have more information. Is there some video from EmDrive conference in Toronto?

By the way guys, do you have any news on the independent testing NASA mentiononed? Like testing at Glenn Research Center and others? Any idea when can se expect some results?

There was some rumor aroud that EmDrive was tested by Boeing and passed. Is that true?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/20/2014 01:11 pm
Striking : interstellar probe page 10, terminal velocity 204429 km/s, thruster efficiency (next page) 0.31. How are we supposed to get this terminal velocity unless there is quite a high wet/dry mass ratio of burned mass ? To get to those speeds with burning less than a few % of the wet mass worth of energy would imply efficiencies much higher than 1. I mean, even if being on an asphalt road between Sun and Proxima  and pushing with wheels.

Energy conservation all broken again !
Title: Re: EM Drive Developments
Post by: frobnicat on 10/20/2014 01:44 pm
Still shocked by interstellar probe. (page 10).
Assume around 10 tons wet mass spaceship, starting reactor full of brand new fissile material.
Say we burn instantly m=2 tons out of that and instantly use all that energy to give kinetic energy to the remaining M=8 tons (this is a favorable case as we don't have to accelerate part of the mass that will be burned later).
Ek = Mc²(gamma-1) = Enuclear = mc²
gamma = m/M +1 = 1.25
That is v = c sqrt(1-1/gamma²) = 180000 km/s,  bit short of the 204000km/s predicted terminal velocity.
And that is by burning 2 tons of mass from a ship that weighs 10 tons (all included, payload, generators, shields, radiators...). 20% mass to energy conversion would be barely sufficient.

Fusion ? Just blind optimism ? Energy conservation broken ? Where does "efficiency of 0.31" comes from ?
Title: Re: EM Drive Developments
Post by: Star One on 10/20/2014 01:51 pm

Here is the PDF mentioned above.

http://www.emdrive.com/iac2014presentation.pdf

Is there a paper with more details to be published ?
"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?

That's all that is presented on their website at this time and is attached to the latest update.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/20/2014 02:01 pm
Woah:

On page 7 of that PDF, they've already got a design for an all electric SSTO!  They can't put that in a paper and post it on the intertubes unless it was true!

I didn't read any further, so I may have missed the fine print regarding ticket prices and carry on baggage.

Hey!  Mucho thankso for the Hendrix clip!

Do you do yoga?  After a weekend of log splitting, I'm looking forward to Hillary's class this PM at 5:30, Downtown.  See ya there?
Title: Re: EM Drive Developments
Post by: Star One on 10/20/2014 02:23 pm

Woah:

On page 7 of that PDF, they've already got a design for an all electric SSTO!  They can't put that in a paper and post it on the intertubes unless it was true!

I didn't read any further, so I may have missed the fine print regarding ticket prices and carry on baggage.

Hey!  Mucho thankso for the Hendrix clip!

Do you do yoga?  After a weekend of log splitting, I'm looking forward to Hillary's class this PM at 5:30, Downtown.  See ya there?

I've seen similar criticism of LM after their fusion announcement last week but I believe they have committed to publish in peer reviewed journals later on. Maybe he intends to do the same for this?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/20/2014 02:52 pm
Been playing around with CAD. See yellow circle in dwg. The vector images in the PDF were squashed. This all hinges on IF the inside of the cavity is 6.25" at the small end. You can 3d orbit to see my construction from left to right. Hope this helps. The website won't let me upload a .dwg. The numbers are in inches and approximate.

The link to it is here:
https://drive.google.com/folderview?id=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM&usp=sharing

Title: Re: EM Drive Developments
Post by: Mulletron on 10/20/2014 02:59 pm
Here is the PDF mentioned above.

http://www.emdrive.com/iac2014presentation.pdf

Is there a paper with more details to be published ?
"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?
...


Shawyer is now claiming with no no dielectric 952 mN/KW, compared to Cannae with dielectric 1.7 mN/KW  (600 times less)


Sheeez

Where is it said the Superconducting Cannae isn't using dielectric?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/20/2014 03:19 pm
Here is the PDF mentioned above.

http://www.emdrive.com/iac2014presentation.pdf

Is there a paper with more details to be published ?
"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?
...


Shawyer is now claiming with no no dielectric 952 mN/KW, compared to Cannae with dielectric 1.7 mN/KW  (600 times less)


Sheeez

Where is it said the Superconducting Cannae isn't using dielectric?

Is the drawing shown next to puny Cannae 1 mN/KW symmetric and with dielectric?

Is the drawing shown next to mighty superconducting Cannae 1000 mN/KW unsymmetric and with no dielectric?

The language of engineers and scientists is drawings, spreadsheets, plots, numbers and formulas instead of words.

Those drawings aren't one for one with the table to the right. sheesh.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/20/2014 03:23 pm
Here is the PDF mentioned above.

http://www.emdrive.com/iac2014presentation.pdf

Is there a paper with more details to be published ?
"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?
...


Shawyer is now claiming with no no dielectric 952 mN/KW, compared to Cannae with dielectric 1.7 mN/KW  (600 times less)


Sheeez

Where is it said the Superconducting Cannae isn't using dielectric?

Is the drawing shown next to puny Cannae 1 mN/KW symmetric and with dielectric?

Is the drawing shown next to mighty superconducting Cannae 1000 mN/KW unsymmetric and with no dielectric?

The language of engineers and scientists is drawings, spreadsheets, plots, numbers and formulas instead of words.

Those drawings aren't one for one with the table to the right. sheesh.
Well, for that we have wembley's information regarding no dielectric. So there  :)

PS: please take a look at my message on the AutoCAD drawing

I can't convert it to something else. It is a 3d drawing anyway. Find a free autocad viewer. The inside dimensions of the cavity are known to me, but not usable to me because of the lack of depth perception in the photo. The bottom diagonal line in the photo was mirrored from the top line instead of drawn manually, and it lined up close to the photo, so I got the center and the width of the small end pretty close to 6.25. That was the sanity check.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/20/2014 03:31 pm
....
I can't convert it to something else. It is a 3d drawing anyway. Find a free autocad viewer. The inside dimensions of the cavity are known to me, but not usable to me because of the lack of depth perception in the photo.
Well, sheeesh

Can you at least post:

Large Diameter=?
Small Diameter=6.25 inches
Length=?

how much work is that instead of all that stuff about polyethylene having magic properties  :)

How would you like it if I would post that I computed that polyethylene has magic thrusting capability with a Mathematica version 10.1 file that you cannot read?   :)

The dims are in the pic, sheesh.......Hello McFly!!!!!!!! knock, knock, knock........

Edited for comedic effect. No disrespect meant, just busting ur balls a bit. Love you guys.
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 03:39 pm
Dimensions in metric units (based on http://forum.nasaspaceflight.com/index.php?topic=29276.msg1273869#msg1273869):


Brady et. al. truncated cone, frustum, dimensions

Length = 0.27635 m
Large Diameter = 0.30523 m
Small Diameter = 0.15875

EDIT: Let's wait until JohnFornaro provides his AutoCAD dimension assessment since the above dimensions are predicated on an assumed small diameter of 6.25 inches (is that known for sure or is it an arbitrary dimension?) and since it is better to have 3 assessments (this last one +aero+JohnFornaro) to calculate
         

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=615993;image)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/20/2014 03:40 pm
http://scitation.aip.org/content/aip/magazine/physicstoday/news/10.1063/PT.5.7115?utm_medium=email&utm_source=Physics+Today&utm_campaign=4848808_Physics+Today%3a+The+week+in+Physics+13-17+October&dm_i=1Y69,2VXD4,E1MTSN,AG4QR,1

Just an odd analogy that just popped up.  Note the motion to the right of the resonating "Hawking Black Hole"
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 03:42 pm
http://scitation.aip.org/content/aip/magazine/physicstoday/news/10.1063/PT.5.7115?utm_medium=email&utm_source=Physics+Today&utm_campaign=4848808_Physics+Today%3a+The+week+in+Physics+13-17+October&dm_i=1Y69,2VXD4,E1MTSN,AG4QR,1

Just an odd analogy that just popped up.  Note the motion to the right of the resonating "Hawking Black Hole"

Outstanding !

Notice:  <<continuing emission of Hawking phonons>>

phonons ==> hence heat !
Title: Re: EM Drive Developments
Post by: Mulletron on 10/20/2014 03:52 pm
Ok, instead of Sheeshing around I will post the Mulletronized dimensions in a language that we can understand (and more noticeable than muted colors on a black background, sheesh  :)):


Brady et. al. truncated cone, frustum, dimensions

Length = 0.27635 m
Large Diameter = 0.30523 m
Small Diameter = 0.15875



compared to the dimensions now in McCulloch's chart:

Length = 0.345 m (25% longer)
Large Diameter = 0.28 (8% smaller)
Small Diameter = 0.17 0.15875 (7% larger)

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=615993;image)

I think someone needs to have a word with you. This disrespectful language about trash bags being made of PE is nonsense. Panty hose are made of Nylon. That doesn't make Nylon any less of a world changer. I spend an hour doing an autocad for the group and you want to pitch a fit. You didn't even click on the picture. Sheesh.
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 05:54 pm
Here is the PDF mentioned above.

http://www.emdrive.com/iac2014presentation.pdf

Is there a paper with more details to be published ?
"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?
1) Does Shawyer explain Conservation of Energy as due to unequal Doppler shift in the forward and aft directions ? (See below)

2) New Shawyer Superconducting EM Drive (just like in his new patent) attached below. 

3) Notice "piezoelectric compensation for Doppler shift"

4) Notice that fore and aft walls of new Shawyer EM Drive are curved.  They are not longer flat bases of a truncated cone.  Perhaps the reason for this is to be able to analyze the resonant modes with a closed-form solution, and thereby to have a better handle at what frequencies the resonant mode frequencies are expected.

5) Notice that there is no longer a cylindrical section to Shawyer's EM Drive that previously was actuated by a motor in order to change the active length of the cavity in order to mechanically control the frequencies at which resonance takes place.

6) Notice that the radial-direction "length" of EM Drive in this new design is now significantly shorter than the length of the circumferential-direction fore and aft surfaces.

EDIT: It is interesting that in Shawyer's superconducting EM Drive design he has considerably reduced the ratio of the radial length "L" of the cavity with respect to the "diameters of the bases". 

Previous Shawyer's design and NASA Eagleworks frustum approximately L = BigDiameter and L > SmallDiameter

in Shawyer's new design  L < BigDiameter and  L < SmallDiameter

this now is closer to meeting the required acceleration for Unruh waves as one needs to meet:

(Diameter/(CavityLength) > 4

7) Notice Shawyer's new EM Drive cavity is made of superconducting yttrium-barium-copper-oxide next to low-thermal-expansion Invar nickel–iron alloy.

8) The picture (attached at the bottom) in the Single Stage to Orbit vehicle shows the old cylinder+truncated cone design of EM Shawyer drive rather than the new superconducting design.

9) This is all that I have been able to find on Cannae's superconducting device (notice it is ~ 3 years old):

http://web.archive.org/web/20121102082714/http://www.cannae.com/proof-of-concept/experimental-results
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 06:44 pm
Bob Ludwick sent me the following message that I post in its entirety (I added bolding for emphasis):

From:   Robert Ludwick
Sent:   Sunday, October 19, 2014 10:13 PM
To:   Dr. J. Rodal
Subject:   Microwave sources

Hello Dr. Rodal,

IslandPlaya, made this comment, perhaps facetiously:

"Indeed!  We need microwave sources that are stable to <0.1 Hz and tunable."

Such sources are readily available from several sources.  This one from
Keysight(formerly HP, then Agilent, now Keysight) is representative:

http://literature.cdn.keysight.com/litweb/pdf/5989-0698EN.pdf

It is tunable in 0.001 Hz steps and is as stable as the reference source if
driven externally.  Off the shelf cesium reference sources are stable in the
e(-13) range, which means that 0.001 Hz steps in the sub-3 GHz range where all
the EmDrive testing has been done are actually meaningful.  Using the internal
source it is stable to +/- 2.5 parts in 10^(-10)/day.

It sounds expensive, until you add up the wasted time and false starts that
can reasonably attributed to testing high Q devices ‘on the cheap’.


Whether or not the Mini-Circuits free running VCO driven by a variable power
supply was causing flaky experimental results, it would be nice to be able
(until Q’s approach Sawyer’s postulated 1e9, where phase noise much closer
than 1 Hz to the carrier becomes an issue) to take source stability off the
‘What’s going on here?’ table.


Bob Ludwick
Title: Re: EM Drive Developments
Post by: aero on 10/20/2014 06:56 pm
I mentioned cosine losses earlier. I wonder, would the RF waves in a small piece of the cavity parallel to the side wall of the cavity produce thrust in the axial direction like delta thrust = delta force * cos(cone half-angle)?

Question: Would the taper, or cone half angle result in cosine losses from the forces generated by the EM thruster? If so, what would be the relative magnitude of such cosine losses?

It is a little bit important because the experimentally measured thrust would necessarily include the cosine loss while our force models do not. But it should be an easy fix to the math models.
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 07:15 pm
I mentioned cosine losses earlier. I wonder, would the RF waves in a small piece of the cavity parallel to the side wall of the cavity produce thrust in the axial direction like delta thrust = delta force * cos(cone half-angle)?

Question: Would the taper, or cone half angle result in cosine losses from the forces generated by the EM thruster? If so, what would be the relative magnitude of such cosine losses?

It is a little bit important because the experimentally measured thrust would necessarily include the cosine loss while our force models do not. But it should be an easy fix to the math models.

I can't calculate a net thrust force for these devices based on classical mechanics so I can't comment on the contribution from the cone revolving surface vs. the contribution from the cone bases.  I posed the question of what happens in the limit as the small base becomes infinitesimally small towards a point (in which case his formula goes to infinity) to Dr. McCulloch and he answered that he had to think about it.  It seems to me that infinite (let alone finite) forces are precluded, and therefore that the revolving cone surface must have an important negative contribution to preclude the infinity that occurs with a pointy cone.

Shawyer points out that the main losses are due to "extraction of kinetic energy, which lower the loaded Q" he thus differentiates between a loaded Q and an unloaded Q, due to conservation of energy:

"The Q of any resonant circuit can be defined as the stored energy divided by the energy loss per cycle. Thus as soon as kinetic energy is extracted from the engine, the stored energy, and hence the Q, falls."


See:  http://emdrive.com/firstgenapplications.html
Title: Re: EM Drive Developments
Post by: aero on 10/20/2014 07:40 pm
I mentioned cosine losses earlier. I wonder, would the RF waves in a small piece of the cavity parallel to the side wall of the cavity produce thrust in the axial direction like delta thrust = delta force * cos(cone half-angle)?

Question: Would the taper, or cone half angle result in cosine losses from the forces generated by the EM thruster? If so, what would be the relative magnitude of such cosine losses?

It is a little bit important because the experimentally measured thrust would necessarily include the cosine loss while our force models do not. But it should be an easy fix to the math models.

Shawyer points out that the main losses are due to "extraction of kinetic energy, which lower the loaded Q" he thus differentiates between a loaded Q and an unloaded Q, due to conservation of energy:

"The Q of any resonant circuit can be defined as the stored energy divided by the energy loss per cycle. Thus as soon as kinetic energy is extracted from the engine, the stored energy, and hence the Q, falls."


See:  http://emdrive.com/firstgenapplications.html

You quoted me but didn't address my question. Sure there are other losses but cosine loss is the reduction of the thrust component in the axial direction, (direction of acceleration) due to the rocket engine being pointed at an angle to the axial direction. In this case of course the whole EM thruster is pointed in the axial direction but the nozzle with flat ends is not shaped to redirect the off axis forces in the axial direction. Maybe a drawing will help.
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 07:44 pm
I mentioned cosine losses earlier. I wonder, would the RF waves in a small piece of the cavity parallel to the side wall of the cavity produce thrust in the axial direction like delta thrust = delta force * cos(cone half-angle)?

Question: Would the taper, or cone half angle result in cosine losses from the forces generated by the EM thruster? If so, what would be the relative magnitude of such cosine losses?

It is a little bit important because the experimentally measured thrust would necessarily include the cosine loss while our force models do not. But it should be an easy fix to the math models.

Shawyer points out that the main losses are due to "extraction of kinetic energy, which lower the loaded Q" he thus differentiates between a loaded Q and an unloaded Q, due to conservation of energy:

"The Q of any resonant circuit can be defined as the stored energy divided by the energy loss per cycle. Thus as soon as kinetic energy is extracted from the engine, the stored energy, and hence the Q, falls."


See:  http://emdrive.com/firstgenapplications.html

You quoted me but didn't address my question. Sure there are other losses but cosine loss is the reduction of the thrust component in the axial direction, (direction of acceleration) due to the rocket engine being pointed at an angle to the axial direction. In this case of course the whole EM thruster is pointed in the axial direction but the nozzle with flat ends is not shaped to redirect the off axis forces in the axial direction. Maybe a drawing will help.

I build my posts my frequent adding and re-editing.  Yes, I added this [at 7:29PM before your 7:40PM message] to address your question:

"I can't calculate a net thrust force for these devices based on classical mechanics so I can't comment on the contribution from the cone revolving surface vs. the contribution from the cone bases.  I posed the question of what happens in the limit as the small base becomes infinitesimally small towards a point (in which case his formula goes to infinity) to Dr. McCulloch and he answered that he had to think about it.  It seems to me that infinite (let alone finite) forces are precluded, and therefore that the revolving cone surface must have an important negative contribution to preclude the infinity that occurs with a pointy cone."

Title: Re: EM Drive Developments
Post by: aero on 10/20/2014 07:44 pm
Shawyer did answer my email in which I ask him for the dimensions of the resonance cavity.

His answer was,

"The small end diameters are set just above the cut-off diameter corresponding to the mode and frequency of the design."

Maybe that will help someone here. Not me.
Title: Re: EM Drive Developments
Post by: aero on 10/20/2014 07:49 pm
@Rodal
 I think we are talking past each other. Look at my drawing  - if that doesn't communicate let me know what it does say to you.
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 07:53 pm
@Rodal
 I think we are talking past each other. Look at my drawing  - if that doesn't communicate let me know what it does say to you.
As a direct answer to the statement "cosine loss is the reduction of the thrust component in the axial direction, (direction of acceleration) due to the rocket engine being pointed at an angle to the axial direction", I cannot understand these EM Drives as a thrusting rocket producing vectors of force, therefore I cannot use the analogy to validate a cosine loss.

From classical (Maxwell's equations) electromagnetic microwave cavity theory I am closer to Frobnicat regarding the electromagnetic tensor causing presure on the cavity surfaces that cancel out (no net thrust to accelerate the center of mass of the EM Drive).   
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 07:59 pm
@Rodal
 I think we are talking past each other. Look at my drawing  - if that doesn't communicate let me know what it does say to you.
As a direct answer to the statement "cosine loss is the reduction of the thrust component in the axial direction, (direction of acceleration) due to the rocket engine being pointed at an angle to the axial direction", I cannot understand these EM Drives as a thrusting rocket, therefore I cannot use the analogy to validate a cosine loss.

From classical (Maxwell's equations) electromagnetic microwave cavity theory I am closer to Frobnicat regarding electromagnetic tensor causing presure on the cavity surfaces that cancel out (no net thrust to accelerate the center of mass of the EM Drive).

Perhaps you can pose this question with your drawing to Dr.McCulloch to see whether your picture and analogy of cosine thrust can be related to his theoretical explanation.  I can't comment on that.

I am interested in Dr. McCulloch's equation regarding mathematically modeling the experiments.  Regarding the Unruh wave explanation, I have a problem with mathematically justifying the required acceleration, as I have posted.

EDIT: It is interesting that in Shawyer's superconducting EM Drive design he has considerably reduced the ratio of the radial length "L" of the cavity with respect to the "diameters of the bases". 

Previous Shawyer's design and NASA Eagleworks frustum approximately L = BigDiameter and L > SmallDiameter

in Shawyer's new design  L < BigDiameter and  L < SmallDiameter

this now is closer to meeting the required acceleration as one needs to meet:

(Diameter/(CavityLength) > 4
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 09:16 pm
I just posted this in Dr. McCulloch's blog:

Although Shawyer does not describe the cavity mode shapes the cavity is resonating at, Brady et.al. does. Brady et.al (NASA) used COMSOL Finite Element analysis to analyze the mode shapes. It is interesting that Brady et.al (A and B in your table above) in your table correspond to the TRANSVERSE MAGNETIC field mode shape TM211, while Brady et.al. (C in your table above) corresponds to the TRANSVERSE ELECTRIC field mode shape TE012.

The TRANSVERSE ELECTRIC mode shape (TE012) resulted in 7 to 4 times greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes (TM211).

See attached (electric field in red and magnetic field in blue):
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 09:47 pm
Further factual, numerical evidence against the importance of the dielectric in NASA's Brady et.al. tests.
The importance of the dielectric is based on this paragraph in the report:

<<We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust.>>

I have noted before:

-very early evaluations
-no Q was reported during these "very early evaluations" without the dielectric
-at 2.168 GHz instead of 1.880 GHz (2.168 GHZ is way off to the right off scale in both the COMSOL Finite Element calculations and in the S21 plot)

What I had not pointed out is that Brady et.al. describe this evaluations at 2.168 GHz to be exactly the same mode shape (TE012) as the mode shape excited at 1.880 GHz which did result in substantial thrust.

The problem is evident: if both the 1.880 GHz and the 2.168 GHz are the same mode shape TE012, then one frequency (2.168 GHz) must be considerably further away from the peak amplitude . It is evident from the S21 plot that the peak amplitude occurs near 1.880 GHz.  Therefore the 2.168 GHz "very early evaluation" with and without the dielectric were conducted at a frequency way away from the narrow bandwidth corresponding to the Q=22,000 measured at resonance at 1.880 GHz.

Therefore, the tests conducted at 2.168 GHz are evidently way off the resonance peak frequency for mode TE012 and hence completely unrepresentative.  No wonder that they did not report a Q at 2.168 GHz, since that frequency was too far away from resonance.

I attach the COMSOL Finite Element predicted amplitude vs frequency (on top) and the S21 actual measurement (on the bottom) of amplitude vs. frequency. Did they test initially at 2.168 GHz based on the COMSOL Finite Element analysis predicting peaks to occur at higher frequencies ?.  It is obvious from comparison of the COMSOL FE results to the actual S21 plot that Brady's COMSOL FE result is inaccurate for these purposes, as it predicts peak amplitudes at a different frequency than the measured frequency.  In my assessment this is due to a modeling problem:was a fine enough mesh used? (apparently not),  was convergence investigated with an increasing number of Finite Elements to show convergence of the results?.  Besides the finite element mesh not being fine enough to demonstrate convergence, was the finite  element type used able to achieve convergence ? (what interpolation function did the finite element use? what finite element shape?).

From the S21 measurements they must have realized that the actual peak for mode TE012 was at a considerably lower frequency than the >2 GHz predicted by the COMSOL Finite Element analysis.  This may explain why Brady et.al. then measured at 1.880 GHz instead of 2.168GHz.
Title: Re: EM Drive Developments
Post by: aero on 10/20/2014 09:55 pm
Doesn't that show the use of less than the ultimate care is construction of the cavity?
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 10:05 pm
Doesn't that show the use of less than the ultimate care is construction of the cavity?
No it is not related to care in physical construction of the cavity.  It just shows that they did not conduct a computational convergence study of their Finite Element analysis investigating finer and finer meshes as well as other types of Finite Elements (with higher order interpolation polynomials) until  achieving convergence.  This could be due to lack of time and urgency for the project to complete in a specified amount of time and not having the time to conduct a convergence study of their Finite Element results.  It could also be due to project priorities: perhaps they prioritized the experimental measurements over the computational analysis.  To Brady's credit they conducted a Finite Element analysis and they properly identified the mode shapes involved.  They deserve kudos for that. I have not seen the mode shapes identified for the experiments conducted in other countries.  I very much appreciate that Brady et.al. conducted the Finite Element analysis and reported the mode shapes. 
Title: Re: EM Drive Developments
Post by: aero on 10/20/2014 10:11 pm
In other words they built the cavity first then tried to figure out how to excite it.
Title: Re: EM Drive Developments
Post by: Rodal on 10/20/2014 10:18 pm
In other words they built the cavity first then tried to figure out how to excite it.

Their Finite Element analysis shows amplitude peaks occurring at very different frequencies and with different amplitudes than occurs in actuality.  So there is no doubt that their Finite Element model is not good enough to represent the actual cavity at the level of frequency resolution needed to conduct the experimental tuning.  It would not be unusual in a fast project in industry to not be able to conduct a finite element mesh study (and finite element interpolation polynomial study) to convergence.

It would not make sense to me that they would build a different model that they modeled or that they would model a different geometry than they built (although it is possible).  So the question is on the finite element mesh and the finite element interpolation type, but the question is not on the geometry.  Due to the FE model being not converged at the level of frequency resolution needed to conduct the experimental tuning, they had to spend some time investigating at what frequency resonance takes place  for different modes.  I do appreciate that Brady et.al. had the initiative to conduct the Finite Element analysis and reported the mode shapes.  I don't recall the studies from other countries showing what mode shapes are being excited.
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/20/2014 11:13 pm
What good does it do to try and sell an electric SSTO space plane and interstellar probes, when they haven't even put together a tabletop demonstration whose effect is visible without high sensitivity instrumentation?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/20/2014 11:47 pm
What good does it do to try and sell an electric SSTO space plane and interstellar probes, when they haven't even put together a tabletop demonstration whose effect is visible without high sensitivity instrumentation?
The *good* it does is to point out how game changing a positive result would be.
Hence a bit more funding. Hence we can get a bit closer to the *truth*
Title: Re: EM Drive Developments
Post by: frobnicat on 10/20/2014 11:49 pm
What good does it do to try and sell an electric SSTO space plane and interstellar probes, when they haven't even put together a tabletop demonstration whose effect is visible without high sensitivity instrumentation?

This overselling applications before much more convincing and detailed and open reproducible experimental design was already complained about. That said, starting to claim hundreds of milliNewtons this should no longer be in the realm of high sensitivity. A good air cushion table should be able to show the thing zipping around (if only it were self contained, including power), and hell, a turnstile also : time to see how the thing goes when approaching the velocity where it gives more energy than it takes. Shawyers semi-classical attempts at mitigating this "problem" with "velocity corrections" are less than convincing to me. Anyone understands the slide 3 of latest presentation and how it's supposed to deal with energy conservation, when the claimed consequences slide 9 & 10 are still out of sensible energy budget (and yet supposedly with efficiency <1 slide 11) ?

good night.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/20/2014 11:54 pm
Maybe the EM frustum setup is a good test for Axions at least...
Title: Re: EM Drive Developments
Post by: aceshigh on 10/21/2014 12:34 am
Terminal velocity = 204,429 km/s = 0.68 c
Even if you can get to 68% of the speed of light, how do you slow down at that point?

https://www.youtube.com/watch?v=Upt7ZTvcriY

reminds me of the book Tau Zero
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 12:35 am
This is something where JohnFornaro and AutoCAD could really help ...

I just plopped

"AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.jpg"

into ACAD, and arbitrarily scaled it.  Nobody's given me a wide end dimension, so, for the purposes of discussion, I just scaled it to your *cough* typical EM-Drive diameter *cough* of 28 cm.

Interesting similarities in the proportions.

Got any more where that came from?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 12:36 am
What good does it do to try and sell an electric SSTO space plane and interstellar probes, when they haven't even put together a tabletop demonstration whose effect is visible without high sensitivity instrumentation?
The *good* it does is to point out how game changing a positive result would be.
Hence a bit more funding. Hence we can get a bit closer to the *truth*

Unfortunately, however, they are selling sizzle before they have a steak.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 12:39 am
This is something where JohnFornaro and AutoCAD could really help ...

I just plopped

"AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.jpg"

into ACAD, and arbitrarily scaled it.  Nobody's given me a wide end dimension, so, for the purposes of discussion, I just scaled it to your *cough* typical EM-Drive diameter *cough* of 28 cm.

Interesting similarities in the proportions.

Got any more where that came from?

Thank you!

Very professional job.  We even got pdf's for everybody to look at!

And everything in metric units as well !

Now, would it be too much to ask to also get cheese with the excellent wine?

We know that the (Faztek)  beam (at the bottom of the picture, shown in cross-section) has a square cross section of 1.5 inch by 1.5 inch

Knowing that, what are the dimensions?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/21/2014 12:39 am
What good does it do to try and sell an electric SSTO space plane and interstellar probes, when they haven't even put together a tabletop demonstration whose effect is visible without high sensitivity instrumentation?
The *good* it does is to point out how game changing a positive result would be.
Hence a bit more funding. Hence we can get a bit closer to the *truth*

Unfortunately, however, they are selling sizzle before they have a steak.
The smell of the sizzle is often good enough to want a burger though...
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 01:29 am
I gladly pay you Thursday for a cheeseburger today.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 01:30 am
Here's the "small" shawyer device.  Correct my titles.
Title: Re: EM Drive Developments
Post by: aero on 10/21/2014 01:30 am
This is something where JohnFornaro and AutoCAD could really help ...

I just plopped

"AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.jpg"

into ACAD, and arbitrarily scaled it.  Nobody's given me a wide end dimension, so, for the purposes of discussion, I just scaled it to your *cough* typical EM-Drive diameter *cough* of 28 cm.

Interesting similarities in the proportions.

Got any more where that came from?

Thank you!

Very professional job.  We even got pdf's for everybody to look at!

And everything in metric units as well !

Now, would it be too much to ask to also get cheese with the excellent wine?

We know that the (Faztek)  beam (at the bottom of the picture, shown in cross-section) has a square cross section of 1.5 inch by 1.5 inch

Knowing that, what are the dimensions?

We also know that the diameter of the chamber is 0.762 meters so the radius is 0.381 meters. Maybe that will help.
Title: Re: EM Drive Developments
Post by: aero on 10/21/2014 01:35 am
Here's the "small" shawyer device.  Correct my titles.

But we know from the documentation that the "small" Shawyer device big end was 16 cm diameter.

Other than that, I really like the way your software presents results.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 01:51 am
Bitch and moan.  All I ever hear around here.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 01:55 am
Bitch and moan.  All I ever hear around here.

Outstanding job!

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 01:56 am
Here's the "small" shawyer device.  Correct my titles.
.... Other than that, I really like the way your software presents results.

That software don't do poop.  Fornaro Inside!

Every last dimension is eyeballed.  I could go to great lengths to geometrically correct for parallax, but without a multiple equational frobnicatory analysis of possible frequencies and resonance, 'twould be a major wast of my time. 

There are commonalities in the proportions.  I point out that there is no 45 degree cone.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 02:06 am
Not like I can't draw or design or anything.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/21/2014 02:08 am
Found this.  Hope the dratted link works: 

http://arc.aiaa.org/doi/abs/10.2514/1.32284

Additional 'Photonic Laser Propulsion Paper'

Dunno...is this one relevant?

http://adsabs.harvard.edu/abs/2011SPIE.8164E..06I

http://adsabs.harvard.edu/abs/2008AIPC..997..561H

'Nanonewton thrust measurement of photon pressure propulsion using semiconductor laser'

Most of it seems to be beyond my feeble reach.  The parts I can understand and access appear similar to what we are discussing...sort of...maybe...eep...

http://adsabs.harvard.edu/cgi-bin/nph-basic_connect

Other stuff at ADS (Astrophysical Data System) that might be relevant here.  Search term I used was 'Photonic Laser Propulsion.'

::Tiptoes quietly away::

Title: Re: EM Drive Developments
Post by: RotoSequence on 10/21/2014 02:11 am
Not like I can't draw or design or anything.

Did you assume, note from citation, or measure the extruded T-slot aluminum to be standard 1.5" (3.81cm) bars?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 02:18 am
Here's the "small" shawyer device.  Correct my titles.

But we know from the documentation that the "small" Shawyer device big end was 16 cm diameter.

Like I said,  Fornaro Inside....

Dimensions, shmimensions.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 02:21 am
Not like I can't draw or design or anything.

Did you assume, note from citation, or measure the extruded T-slot aluminum to be standard 1.5" (3.81cm) bars?

We know that the (Faztek)  beam (at the bottom of the picture, shown in cross-section) has a square cross section of 1.5 inch by 1.5 inch...

Check out the 3.81cm dimension.  If dat ain't right tell me what is.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 02:22 am
::Tiptoes quietly away::

I don't have time for that.  I'm too busy making incorrectly scaled drawings.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 02:29 am
Here's the "small" shawyer device.  Correct my titles.
.... Other than that, I really like the way your software presents results.

That software don't do poop.  Fornaro Inside!

Every last dimension is eyeballed.  I could go to great lengths to geometrically correct for parallax, but without a multiple equational frobnicatory analysis of possible frequencies and resonance, 'twould be a major wast of my time. 

There are commonalities in the proportions.  I point out that there is no 45 degree cone.

It is a really outstanding job.

Based on the last drawing, that has the dimensions for the Big Diameter based on the 1.5"x1.5" cross section, given to us by Paul March,

I compute the following based on scaling of Fornaro's drawing:


Brady et.al.

Length = 0.33245 m
BigDiameter = 0.39697 m
SmallDiameter = 0.24393 m


The ratios (Length to Big Diameter, and Length to Small Diameter) are pretty close to aero:

                    L/BigDiameter                                   L/SmallDiameter              ( L/SmallDiameter  - L/BigDiameter)

Fornaro     0.8375                                              1.3629                            0.525422
aero             0.92                                                  1.3939                            0.473939
Mulletrn        0.90538                                            1.7408                            0.835404

Since John used a superior method, using the known dimensions of the cross section of the beam, and it is the median measurement (using the above-mentioned ratios),

Let's take John's measurements  for Brady et.al.

Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 02:31 am
Not like I can't draw or design or anything.

Did you assume, note from citation, or measure the extruded T-slot aluminum to be standard 1.5" (3.81cm) bars?

This dimension was given to us by Paul March (a member of Dr. White's team) more than a 100 pages along (time flies)
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 02:40 am
Found this.  Hope the dratted link works: 
....
Other stuff at ADS (Astrophysical Data System) that might be relevant here.  Search term I used was 'Photonic Laser Propulsion.'

Thanks
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 02:44 am
(time flies)

Yea.  Time flies like the wind, and fruit flies like bananas.

Again.  I eyeballed all those dimensions, kinda sorta correcting for parallax.  You zoom into the intersecting points of the lines with the JPEG image, and you can see what I mean.  We need to add to the Cat's work in getting him to explore the ramifications of the various dimensions and RF frequencies.  'Course, he's French.  Prolly atta latteria or whatever they call 'em over there.  You know how it is:  "Latte" is just the French term for "You paid too much for that coffee".  I need to check "News in Slow French", then off to bed.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 02:56 am

This dimension was given to us by Paul March (a member of Dr. White's team) more than a 100 pages along (time flies)

Dang it! Neglected to drag one of the dimensions.  Rushing to get to bed.

Try this:
Title: Re: EM Drive Developments
Post by: Mulletron on 10/21/2014 08:25 am
Here's the "small" shawyer device.  Correct my titles.
.... Other than that, I really like the way your software presents results.

That software don't do poop.  Fornaro Inside!

Every last dimension is eyeballed.  I could go to great lengths to geometrically correct for parallax, but without a multiple equational frobnicatory analysis of possible frequencies and resonance, 'twould be a major wast of my time. 

There are commonalities in the proportions.  I point out that there is no 45 degree cone.

It is a really outstanding job.

Based on the last drawing, that has the dimensions for the Big Diameter based on the 1.5"x1.5" cross section, given to us by Paul March,

I compute the following based on scaling of Fornaro's drawing:


Brady et.al.

Length = 0.33245 m
BigDiameter = 0.39697 m
SmallDiameter = 0.24393 m


The ratios (Length to Big Diameter, and Length to Small Diameter) are pretty close to aero:

                    L/BigDiameter                                   L/SmallDiameter              ( L/SmallDiameter  - L/BigDiameter)

Fornaro     0.8375                                              1.3629                            0.525422
aero             0.92                                                  1.3939                            0.473939
Mulletrn        0.90538                                            1.7408                            0.835404

Since John used a superior method, using the known dimensions of the cross section of the beam, and it is the median measurement (using the above-mentioned ratios),

Let's take John's measurements  for Brady et.al.
http://www.grainger.com/product/FAZTEK-Framing-Extrusion-5JA96?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/5JA94_AS01?

Sorry but this solution doesn't work. See the screenshot and link to drawing. The 1.5inch reference is at an arbitrary depth so you can't use it. The same reason I couldn't use the width of the chamber. Also, we want inside dimensions, not outside.

https://drive.google.com/folderview?id=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM&usp=sharing
Stanley Cupric1.dwg

The pic below is the result of the wrong solution.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/21/2014 11:14 am
I'm chasing a hot lead, which if it holds, may allow emdrive to provide thrust from a sealed cavity without breaking any physical laws, teaching photons new tricks, adjusting C, etc... (dielectric present or not, air is dielectric too anyway)........evanescent wave coupling, quantum tunneling is the QM analogue. Part of my research into near field effects. Anybody want to take a stab at it? I'm at the very early stages of it and I'm desperately trying to prove the idea wrong.

I've had some exposure to this kind of concept in my own nerdery over the years, and I may have actually encountered it at work by accident when I noticed I could pick up the energy inside our waveguides very faintly with a spectrum analyzer and a crude probe I made, even though the waveguides were sealed, no flanges anywhere nearby, and there were no leaks detected by the rf sniffer. I just had to get close to the waveguide with the probe and I could see our transmit carriers.

I have got to find out for certain the wall thickness of the Nasa test article tapered frustum.

Neat simulation tool plugin for MATLAB:

http://www.problemsinelectrodynamics.com/tools/interactive-fdtd-toolbox
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 12:59 pm
Sorry but this solution doesn't work. See the screenshot and link to drawing. The 1.5inch reference is at an arbitrary depth so you can't use it. The same reason I couldn't use the width of the chamber. Also, we want inside dimensions, not outside.

Not that I'm right or anything, but I would observe that the visual vertical orientation of the device suggests that the line of the cone's vertical diameter passes thru the center line line of the Faztek thingy, virtually in the same plane perpendicular to the camera.  The parallax is to be ignored in my analysis, and the distance of the cone and thingy from the camera is immaterial.

There only appears to be two sizes for the Fazteck thingy:  1.5" and 3":  http://www.faztek.net/  I'm guessing this isn't the 3" product.

Ipso fatso: Scaling the foto on that piece of evidence is appropriate. 

I'm including the CAD file for reference, with a note of appreciation to the foax at AutoCAD, who change their drawing format hourly so as to protect what they think is their intellectual property, while ignoring that were they to have an accessible database, and were to improve the functioning of their CAD products instead of changing the drawing format, they would probably have more sales and greater market penetration, but I digress just a mite.

ACAD R14 is a 1997 product, and they refuse to improve that product.  If the whiz bang kids at Mathematica and Comsol cain't read legacy .DWG's, that's their problem.

Point being: Twerk the CAD file.  Also, in my eye, color is a distraction, and your drawing is hard on old eyes.  That's why I converted the JPEG to a touch of grey (http://www.youtube.com/watch?v=wOaXTg3nAuY).

Anyhow.....

As to the idea of measuring the inside of the cavity, thou art spot on.

It has been suggested that the inside must be properly mirrored for the desired M/W resonance.  The inside of that cone has to be conically flat.  Dollars to donuts sez it ain't.  Not if it is made of 1/8" thick copper.  The inside may have been polished with Turtle Wax, but it has not been polished nor flattened to Hubble specs.  The substrate is too thin.  The exterior has a mill finish only.  Was it formed over a wood mandrel?  Who knows?

I employ the doctrine of the fair witness (http://en.wikipedia.org/wiki/Stranger_in_a_Strange_Land).  Also known as calling 'em like I see 'em.

Since i can only follow the addition, subtraction, multiplication and some division of the math, I have trouble following the intricacies of the arguments being presented.  I do follow the general gist however.

And.  I do know that there's an awful lotta predictions being made without crucial information.  Information which is not being shared for obvious reasons.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/21/2014 01:18 pm
Sorry but this solution doesn't work. See the screenshot and link to drawing. The 1.5inch reference is at an arbitrary depth so you can't use it. The same reason I couldn't use the width of the chamber. Also, we want inside dimensions, not outside.

Not that I'm right or anything, but I would observe that the visual vertical orientation of the device suggests that the line of the cone's vertical diameter passes thru the center line line of the Faztek thingy, virtually in the same plane perpendicular to the camera.  The parallax is to be ignored in my analysis, and the distance of the cone and thingy from the camera is immaterial.



Notice the 1.5inch dims in yellow in the foreground and background. Because of depth perception, one is behind the test article and the other is in front. That creates a situation where you can't rely on the 1.5inch reference without knowing the viewing angle of the camera and at least one length in the Z axis of the chamber (the direction you're looking). I think I got it pretty close using the 6.25 inch internal PE disk reference from the paper. That allowed me to do 3 transformations in x, y, z to get pretty close but not exact. The z axis of the cavity was a result of x, y transformations, and still ended up being an eyeball job after proper scaling. My CAD drawing is linked to above for peer review. I hear you on Autodesk. I'm using Acad 2000. It is good enough. I'm not buying a new one.

Edit:
I just realized I (or anyone else) can just use both foreground and background 1.5inch references at once and some simple math to nail the drawing.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/21/2014 01:33 pm
http://www.nytimes.com/video/technology/100000003187690/a-real-hoverboard.html?emc=edit_th_20141021&nl=todaysheadlines&nlid=18173476

A Real Hoverboard ?

http://www.nature.com/news/physicists-see-potential-dark-matter-from-the-sun-1.16174

And Axions ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 02:16 pm
...
Point being: Twerk the CAD file.  Also, in my eye, color is a distraction, and your drawing is hard on old eyes.  That's why I converted the JPEG to a touch of grey (http://www.youtube.com/watch?v=wOaXTg3nAuY).
...
Thank you for being kind to my eyes, and noticing this John.  Much appreciated.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 02:33 pm
Notice the 1.5inch dims in yellow in the foreground and background. Because of depth perception, one is behind the test article and the other is in front. That creates a situation where you can't rely on the 1.5inch reference without knowing the viewing angle of the camera and at least one length in the Z axis of the chamber...

Well, I took anudder look at your sketch, and still stick with my interpretation.  The camera appears to be damn near perpendicular to the centerline of the cone, and perpendicular to the z-axis of the large end diameter which is nearly centered on the lens of the camera.  If anything, the rear of the cone rim is slightly to the left of center, but I ignored that.

I note that the support is not at right angles to the plane of the large diameter of the cone, and not at all at right angles to its own vertical support Faztek, but I don't think that matters. 

What matters to the camera is that the Faztek horizontal support is centered on the cone's axis.  If that is the case, the dimension that I show should be spot on within a plus or minus.  The support is clearly not vertically off center, but it may be nearer or further from the camera than the centerline of the cone's axis.  I can't tell, and I can't help that.

The other support that you dimension appears to be a 3" chunk of Faztek, at least to this pair of retinas.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 02:33 pm
....
It has been suggested that the inside must be properly mirrored for the desired M/W resonance.  The inside of that cone has to be conically flat.  Dollars to donuts sez it ain't.  Not if it is made of 1/8" thick copper.  The inside may have been polished with Turtle Wax, but it has not been polished nor flattened to Hubble specs.  The substrate is too thin.  The exterior has a mill finish only.  Was it formed over a wood mandrel?  Who knows?
...
No, it was not a suggestion.  It is not based on words, or intuition.  It follows from Maxwell's equations.
It is not based on looking at Wikipedia articles. It is not based on scouring the Internet looking at blogs.
It is based on looking at MIT Electrical Enginering course work material.

What was stated in http://forum.nasaspaceflight.com/index.php?topic=29276.msg1273676#msg1273676

It is based on this:

Q =( Length / skinDepthForResonantFrequency) / (1 + ( 2*Length / InnerDiameter ))

skinDepthForResonantFrequency = 1/Sqrt[Pi*ResonantFrequency*μ*σ]


The statement was:

1) Both inner surface ends of the truncated cone must have been made out of copper. Otherwise the cavity would not have the correct boundary conditions to be a resonant cavity: it would be a waveguide.  One wouldn't be able to have high Q and resonance if the inner surface of the ends wouldn't be copper.

2) The inner surface of the copper must have been pretty well polished, in order to get Q~50 000, given the calculated skin depths

3) There cannot be any significant irregularities on the inside surface of the truncated cone.



This follows from Maxwell's equations.  If Shawyer reports for his demo Q=45000, then it must follow that either:

A) the inner surface of Shawyer's demonstration EM Drive must have been pretty well polished in order to obtain Q=45000, without significant irregularities on its inside surface

or

B) the reported Q=45000 is an incorrect reported value

Also observe that NASA Eagleworks did not report as high Q's as the Q=45000 reported by Shawyer for the demonstrator EM Drive. NASA Eagleworks reported Q's ranging from 7000 to 22000, which is significantly less (Q=7000 is 7 times less).  Therefore, it must follow (from the solution to Maxwell's equations) that:

A) NASA Eagleworks truncated cone's inner surface was not as well polished and free of irregularities as Shawyer's demonstration EM Drive

or

B) the reported Q's are incorrect

John, you just cannot have a high Q with a poor, irregular surface on the inside, when the skin depth is a couple of micrometers or less.  You don't need to exaggerate about Hubble specs or similar exaggeration not present in the statement that you are objecting to.

John, if there is no inner copper on the ends of the cavity (showing PCB board on the outside) then you cannot have a resonant cavity, so the inner surface ends must have been made out of highly-conductive material like copper.

There is no way out of this: reported Q's are giving us information about the inner surface and material of the cavities.   If you claim that the inner surface of the ends was not made out of a highly conductive material like copper, then you are stating that the reported Q's are completely incorrect, if you state that the inner surface of the cavities was significantly irregular, then Q cannot reach 45000, and effectively you are stating that you think that the reported Q is incorrect.

Similarly regarding Shawyer's statement about Q's several orders of magnitude higher: the only way to obtain such Q's is to make the inner surface of the cavity out of superconducting material and have the cavity at temperatures where superconductivity can take place.

Title: Re: EM Drive Developments
Post by: Mulletron on 10/21/2014 02:35 pm
http://www.nytimes.com/video/technology/100000003187690/a-real-hoverboard.html?emc=edit_th_20141021&nl=todaysheadlines&nlid=18173476

A Real Hoverboard ?

http://www.nature.com/news/physicists-see-potential-dark-matter-from-the-sun-1.16174

And Axions ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/21/2014 03:03 pm
Quote
1) Both inner surface ends of the truncated cone must have been made out of copper. Otherwise the cavity would not have the correct boundary conditions to be a resonant cavity: it would be a waveguide.  One wouldn't be able to have high Q and resonance if the inner surface of the ends wouldn't be copper.

While copper is a preferred material for waveguides. (Because it is cheaper than gold for example) It isn't the only material a resonant cavity can be made of. As a matter of fact, the inner surface of tubes I work with are regularly gold plated, while the rest of the structure is copper. Copper loves to oxidize and turn green, so much of what I see is copper, and plated with gold. We also pressurize with nitrogen and/or dry air to keep the oxidation down and not spend money on long lengths of fancy gold plated waveguide.

Also a resonant cavity is a waveguide, with both ends shorted.

Some are purpose build too, like magnetrons (collection of resonant cavities)

The point is, that you can take an ordinary waveguide, weld the ends shut and it is now a resonant cavity.

The smoother the better, to decrease scattering. Definitely no dents allowed or you get standing waves or arcing. You don't need to polish the thing. EHF frequencies need to be very very smooth. The lower frequencies, who cares.

This is from 15 years doing the job hands on.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 04:57 pm
Notice the 1.5inch dims in yellow in the foreground and background. Because of depth perception, one is behind the test article and the other is in front. That creates a situation where you can't rely on the 1.5inch reference without knowing the viewing angle of the camera and at least one length in the Z axis of the chamber...

Well, I took anudder look at your sketch, and still stick with my interpretation.  The camera appears to be damn near perpendicular to the centerline of the cone, and perpendicular to the z-axis of the large end diameter which is nearly centered on the lens of the camera.  If anything, the rear of the cone rim is slightly to the left of center, but I ignored that.

I note that the support is not at right angles to the plane of the large diameter of the cone, and not at all at right angles to its own vertical support Faztek, but I don't think that matters. 

What matters to the camera is that the Faztek horizontal support is centered on the cone's axis.  If that is the case, the dimension that I show should be spot on within a plus or minus.  The support is clearly not vertically off center, but it may be nearer or further from the camera than the centerline of the cone's axis.  I can't tell, and I can't help that.

The other support that you dimension appears to be a 3" chunk of Faztek, at least to this pair of retinas.

Looking at message:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1274165#msg1274165


                    L/BigDiameter                                   L/SmallDiameter              ( L/SmallDiameter  - L/BigDiameter)

Fornaro     0.8375                                              1.3629                            0.525422
aero             0.92                                                  1.3939                            0.473939
Mulletrn        0.90538                                            1.7408                            0.835404

It is evident that the last entry on the table is significantly  different: the ratio for Length to SmallDiameter is significantly larger than the other two, this ends up having a very large effect on  ( L/SmallDiameter  - L/BigDiameter): 77% higher.  The first two rows on the table are closer to each other.

This is due to the ratio of the SmallDiameter to the Length. Since all three rows are closer as to the ratio L/BigDiameter, it necessarily follows that the discrepancy is due to the magnitude of the SmallDiameter.
The last row on the table has a value for the SmallDiameter in proportion to the length and in proportion to the BigDiameter that differs considerably from the first two rows.

If one magnifies or reduces both x and y axis by the same ratio on both the vertical and horizontal axes, the ratio L/SmallDiameter should stay the same. 

Having said that, Paul March informed us (  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1253965#msg1253965  ) that all of the Faztek beams used are 1.5"by1.5" cross section, so the cross-section appearing at the front bottom of the picture must also be 1.5"by1.5":

http://www.amazon.com/Faztek-15QE1515UL-Aluminum-T-Slotted-Extrusion/dp/B008MQA11C

So, this would indicate that John's last numbers should be scaled down proportionally accordingly. One Faztek cross-section appears on the foreground, then the truncated cone and then on the background is the other Faztek cross-section. This should not have any effect on the values computed by McCulloch' formula based on the present values supplied by John (McCulloch' formula is only dependent on the ratios L/Diameter and therefore not on the absolute magnitude).

So, for McCulloch's formula calculation there is no need to change the magnitude of John's values.

But the magnitude is important for Frobnicat's analysis since many of the equations investigated depend on the magnitudes.

Title: Re: EM Drive Developments
Post by: Mulletron on 10/21/2014 05:13 pm
Still learning about evanescent fields. I found some good resources from the field of total internal reflection fluorescence microscopy. I see lots of data out there about evanescent fields around waveguides too. The same methodology can be applied to RF and waveguides it seems. I'm getting closer to calculating the evanescent field penetration depth of RF through copper. This is an interesting learning experience. In retrospect to my training as a young pup, it is clearer now why adjacent waveguides are kept separated from each other. I remembering learning that, but the details of why were left out.

http://olympusmicro.com/primer/java/tirf/penetration/index.html (neat tool, can probably adapt this)
http://www.physics.uwo.ca/~smittler/tweezers.html
http://www.nature.com/ncomms/2014/140306/ncomms4300/full/ncomms4300.html
http://arxiv.org/abs/1308.0547


Title: Re: EM Drive Developments
Post by: aero on 10/21/2014 05:35 pm
Has anyone else looked at this Chinese theory/cavity design paper? It is interesting that the author used finite element integration of the Maxwell equations over the cavity volume to determine the most favorable modes and cavity dimensions, and to predict thrust. I bet someone on here could run the same analysis using free finite-difference time-domain (FDTD) software.

http://www.emdrive.com/NWPU2010translation.pdf (http://www.emdrive.com/NWPU2010translation.pdf)
Quote
4 Conclusion
Microwave thrusters without propellant does not require propellant, so without erosion from the high temperature gas stream, erosion and heat transfer problem, the performance of the thrusters is not affected by the working environment, at the same time, increasing the spacecraft quality, using different material for the structure can increase the range of thrust, suitable for use in space and near space spacecraft.

There are two ways to explain this new thrusters,

(1) from the Plank’s hypothesis and Einstein’s quantum theory of light, also the theory of microwave to explain the thrust from the thrusters, that is to quantise the injected microwave to the sealed cavity into photons, its travelling speed is the group speed, photons and the thrust cavity wall elastic collision produce the net thrust,

(2) From the classic theory of electrodynamics to explain how the thrust is produce by the thrusters, according to the kinetic energy and conservation of momentum of the electromagnetic system within its volume, Maxwell equation and electromagnetic flux density vector can found out the source of the thrust is coming from the integration of the electromagnetic tensor along the surface of the volume.

Using finite element numerical method to numerical analyse the classical Maxwell equation of electric field of the idealised conical resonator, to obtain the model and practical of the distribution of the electric field of the cavity under 1000W. By analyse the properties under different modes and the different properties. Calculation show that under the four modes, TE011, TE012, TE111 and TM011, the quality factor of TE012 is highest and with highest thrust, followed by TE011. With the Small End of the cavity unchanged, the quality factor and thrust decrease with the increase in the Large End.

The TE10 mode rectangular waveguide is suitable for use in modes TE011 and TE012, and coupling to the side wall of the resonator in where the magnetic field is relatively strong, coupling using coaxial cable is suitable in modes TE011 and TM011, in axis of the resonator where electric field is relatively large.
With 1000W microwave input, using brass as the material of the cavity, using the classical theory of electrodynamics, the maximum theoretical thrust produced in modes TE011 and TE012 is 411mN and 456mN respectively, and the practical measurements are 214mN and 315mN.

Of course this does not explain conservation of momentum of a spacecraft using these thrusters, only the force distributions within the resonate cavity.

This sentence stands out -
Quote
With the Small End of the cavity unchanged, the quality factor and thrust decrease with the increase in the Large End.
I believe the author is referring to "increase in the large end" relative to the ideal geometry derived near the start of the paper.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 05:52 pm
Has anyone else looked at this Chinese theory/cavity design paper? ...

Thank you so much for bringing up this information.  There is a lot of useful information here.  In this post, I would like to emphasize the following:

Quote
By analyse the properties under different modes and the different properties. Calculation show that under the four modes, TE011, TE012, TE111 and TM011, the quality factor of TE012 is highest and with highest thrust, followed by TE011. With the Small End of the cavity unchanged, the quality factor and thrust decrease with the increase in the Large End.

The TE10 mode rectangular waveguide is suitable for use in modes TE011 and TE012, and coupling to the side wall of the resonator in where the magnetic field is relatively strong, coupling using coaxial cable is suitable in modes TE011 and TM011, in axis of the resonator where electric field is relatively large.
With 1000W microwave input, using brass as the material of the cavity, using the classical theory of electrodynamics, the maximum theoretical thrust produced in modes TE011 and TE012 is 411mN and 456mN respectively, and the practical measurements are 214mN and 315mN.

This further confirms this previous post:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1274035#msg1274035

that the TRANSVERSE ELECTRIC mode shape result in greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes

<<Although Shawyer does not describe the cavity mode shapes the cavity is resonating at, Brady et.al. does. Brady et.al (NASA) used COMSOL Finite Element analysis to analyze the mode shapes. It is interesting that Brady et.al (A and B in your table above) in your table correspond to the TRANSVERSE MAGNETIC field mode shape TM211, while Brady et.al. (C in your table above) corresponds to the TRANSVERSE ELECTRIC field mode shape TE012.

The TRANSVERSE ELECTRIC mode shape (TE012) resulted in 7 to 4 times greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes (TM211).

See attached (electric field in red and magnetic field in blue):>>
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 05:59 pm
We now have separate confirmation in both China and the USA that thrust force measurements are related to the TRANSVERSE ELECTRIC modes, since their mode shape result in greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes.

This is a further challenge [ and a hint ] to explaining the measured thrust forces in these EM Drives as resulting from the magnetic field interacting with the Earth's magnetic field or with other magnetic fields (like the magnetic damper)


It also explains why NASA Eagleworks explored resonance for the mode TE012

EDIT:  Electric and magnetic fields are two interrelated aspects of the same electromagnetic tensor; the split of this tensor into electric and magnetic fields depends on the relative velocity of the observer and charge.  Therefore my original wording (challenge to thought process) should be changed to "challenge and hint".  It is a powerful hint to make us think as to what is going on.

The interaction with the Earth's magnetic field is challenged because of experimental data changing the orientation of the drive.  Shawyer had the EM Drive also positioned vertically and also positioned horizontally, and also rotating continuously around a vertical axis.  If there is a magnetic interaction with the Earth's field it is a challenge to explain the same thrust force and intrinsic direction with the EM Drive positioned vertically and horizontally and with the NASA Eagleworks to flip the drive in the horizontal direction as well. (think of the right hand rule)

(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQRDu1ggjBm6owYInisjXRIlib9Xvw7QDBFXlZH2mAkyO8waOW8)

(http://www.aplusphysics.com/courses/honors/magnets/images/2ndRHR.png)

 :)     ;)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/21/2014 06:09 pm


This is a further challenge to explaining the measured thrust forces in these EM Drives as resulting from the magnetic field interacting with the Earth's magnetic field or with other magnetic fields (like the magnetic damper)




That is a Quantum Leap Doc......Except for the fact that the magnetic field lines are oscillating about the Z axis (small end to big end). The direction we're thrusting.

A study of any issue is moot without the observer possessing a healthy dose of skepticism, and sufficient training in knowing the difference between logic and logical fallacy, and not falling prey to cognitive bias.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 06:13 pm
This sentence stands out -
Quote
With the Small End of the cavity unchanged, the quality factor and thrust decrease with the increase in the Large End.

I don't know Chinese, so I cannot read the original paper, but I notice that the translator writes that the cavity was made of brass.  I wonder whether this is a translation issue where the translator substituted "brass" for what should have been copper (or another copper alloy other than common brass).

My interpretation of what the translator actually wrote above is that keeping the diameter of the small base of the truncated cone constant, that Q and the thrust force decrease as one increases the diameter of the large base.  I know this contrary to McCulloch's formula and contrary to expectations, but this is what the translator wrote.
Title: Re: EM Drive Developments
Post by: JasonAW3 on 10/21/2014 06:20 pm
We now have separate confirmation in both China and the USA that thrust force measurements are related to the TRANSVERSE ELECTRIC modes, since their mode shape result in greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes.

This is a further challenge to explaining the measured thrust forces in these EM Drives as resulting from the magnetic field interacting with the Earth's magnetic field or with other magnetic fields (like the magnetic damper)


It also explains why NASA Eagleworks explored resonance for the mode TE012

It almost seems that the Magnetic field is interacting with Space itself in this case, much how gravity distorts spacethis configuration of a magnetic field appeasrs to be doing the same thing.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 06:35 pm
1) If one computes the net forces produced by the magnetic field and by the electric field  (which are standing waves) the net forces sum up to zero.  It is a closed system. There is no net thrust on the center of mass using Maxwell's equation.


2) I have to read the Chinese papers again, but my recollection is that they use Minkowski's stress tensor instead of Abraham's stress tensor.  Minkowski's stress tensor is asymmetric.   Mass cannot be asymmetric (there must be a center of mass ! ), that's why Abraham imposed symmetry of the tensor from the outset.  When using Mynkowski's stress tensor one has to consider an open system together with hidden momentum (as done by Shockley).  If the Chinese got a net force without considering any non-classical physics effect, it seems to me that they must not have adequately considered hidden momentum.  In other words, using Minkowski's stress tensor cannot be by itself an explanation of thrust.

3) The Chinese translator's statement <<With the Small End of the cavity unchanged, the quality factor and thrust decrease with the increase in the Large End.>> poses further questions regarding their analysis.

4) The experimental fact that the Transverse Electric field modes result in greater Q and greater force measurements than the Transverse Magnetic modes is valuable and stands on its own (apart from their analysis of force).
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 06:42 pm
Quote from: Rodal
]There cannot be any significant irregularities on the inside surface of the truncated cone.

I don't know if the inside has been polished, and neither do you.  The outside has only a mill finish, somewhat tarnished by handling.  The thickness of the various plates and what have you might be 1/8" in thickness.

Your words were, that there cannot be "significant" irregularities on the inside surface of the cone.  If the inside is finished like the outside, then I don't think that the loose term which you used, and which I accept for purposes of discussion, is "sufficiently" regular.

Since you did not specify the level of polishing, nor the "flatness" of the conical section line, nor the surface qualities of the copper, yours is but a suggestion. 

Quote from: Rodal
No, it was not a suggestion.  It is not based on words, or intuition.  It follows from Maxwell's equations.

I took a guess that the level of polishing on Hubble's mirrors would be sufficient.  Somewhere between mill finish and Hubble polish, there is a "sufficiently" regular finish.

Obviously Hubble is not optimized for M/W reflectance, and I merely mention a reflective analogy because of the importance of establishing a lossless reflection of the M/W's in the cavity.

Savvy?

Quote from: Rodal
John, you just cannot have a high Q with a poor, irregular surface on the inside, when the skin depth is a couple of micrometers or less.  You don't need to exaggerate...

John, if there is no inner copper on the ends of the cavity (showing PCB board on the outside) then you cannot have a resonant cavity, so the inner surface ends must have been made out of highly-conductive material like copper.

Oh, I get that.  Show me the copper, however.  I'm assuming it's there too.  I make no objections, but ask about the quality of the mirrored finish on the inside of the device; an inside which no forum human has witnessed.

As to 1.5" & 3" Faztek.  If my assumption that the horizontal member, which I took to be 1.5" or 3.81 cm is NOT in the center of the device, then my A1.4 measurement is way off. 

Looking again at the piece of Faztek jutting out towards the camera, and looking at the catalog, I see a straightforward resemblance to the 3" square Faztek, not the 1.5" Faztek. 

http://www.faztek.net/products.asp?cat=11
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 06:47 pm
We now have separate confirmation in both China and the USA that thrust force measurements are related to the TRANSVERSE ELECTRIC modes, since their mode shape result in greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes.

This is a further challenge to explaining the measured thrust forces in these EM Drives as resulting from the magnetic field interacting with the Earth's magnetic field or with other magnetic fields (like the magnetic damper)


It also explains why NASA Eagleworks explored resonance for the mode TE012

It almost seems that the Magnetic field is interacting with Space itself in this case, much how gravity distorts spacethis configuration of a magnetic field appeasrs to be doing the same thing.

This is my thinking:

It is the electric field modes (not the magnetic modes) that show the greater Q and greater thrust, not the other way around.  There is no such thing as "thrust" using classical Maxwell's equations.  It is a closed system.  The magnetic field vectors from both bases point towards the center.  There is no net magnetic force on the center of mass using classical Maxwell's equations.

If on the other hand, one uses non-classical physics it doesn't follow that the force must come from the magnetic field, on the contrary, for example McCulloch's explanation of inertial changes due to Unruh radiation, it is the photons inertia that matters.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 06:53 pm
As to 1.5" & 3" Faztek.  If my assumption that the horizontal member, which I took to be 1.5" or 3.81 cm is NOT in the center of the device, then my A1.4 measurement is way off. 

Looking again at the piece of Faztek jutting out towards the camera, and looking at the catalog, I see a straightforward resemblance to the 3" square Faztek, not the 1.5" Faztek. 

http://www.faztek.net/products.asp?cat=11

As to polishing, all that is required is to use a Profilometer on the surface and be smooth enough to less than a fraction of a micrometer because the skin depth is ~2 micrometers.  That does not need to be a mirror surface.  Not Hubble mirror. Not mirror on the wall. No nanometer profile.



Is this the 3" by 3" Faztek that you referring to?  (http://www.faztek.net/prodimages/15EX3030.gif)

(If not could you please post the specific  3" by 3" Faztek  picture you are referring to?)

Because that looks very different from this 1.5" by 1.5", which looks much more as to what is in Brady's

(http://www.faztek.net/prodimages/15EX1515L.gif)

Me a primitivo-man without AutoCAD and just looking at picture and just counting

Me a pre-AutoCad-man just looking at 2 slots per side on the 3"by3" and 1 slot per side on the 1.5" by 1.5"
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/21/2014 07:04 pm
Blah blah arguing about words (not the equation)...

As to 1.5" & 3" Faztek.  If my assumption that the horizontal member, which I took to be 1.5" or 3.81 cm is NOT in the center of the device, then my A1.4 measurement is way off. 

Looking again at the piece of Faztek jutting out towards the camera, and looking at the catalog, I see a straightforward resemblance to the 3" square Faztek, not the 1.5" Faztek. 

http://www.faztek.net/products.asp?cat=11

Is this the 3" by 3" Faztek that you referring to?

(If not could you please post the specific  3" by 3" Faztek  picture you are referring to?)

Because that looks very different from this 1.5" by 1.5", which looks much more as to what is in Brady's

Me a "homo primitivo" without AutoCAD and just looking at picture and just counting

Me a "homo primitivo" just looking at 2 slots per side on the 3"by3" and 1 slot per side on the 1.5" by 1.5"

There are two extruded bars shown edge-on in the embedded shot, which clearly demonstrates that the assembly is made from 1.5" x 1.5" bars, rather than 3" x 3".
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/21/2014 07:07 pm
It's 1.5" x 1.5"
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 07:18 pm
Well, alrighty then.  Look at my A1.2 PDF.  The Faztek image there is real blurry on account of the TIFF having been enlarged by 50 some odd times.  So, mea culpa on that.  Didn't occur to me to go back to the original JPEG.

Now.  Is the horizontal piece that I use as 1.5" (3.81cm) in the center of the device?  If so, then my extrapolation should be correct to plus or minus.  If not, and the horizontal member is further to the rear, then again, my extrapolation is bogus.

Me needum drinkum.  Will see mixologistum tomorrowum.

Edit:

Loooked harder.  I don't think that the 1.5" Faztek thingy is in the center of the copper can.  I think it is behind the whole assembly.  Not at all sure I go with Mulletron's guess as to the dimensions of the can.  All I can say is that the proportions, but not the dimensions I sketched out, are reasonably accurate.

I note that we are spending a lotta time arguing about these dimensions.  The good Doctor asked, rather politely a hundred or more pages ago, but got only partial dimensional answers.  Since then Paul March decided to go mum.  Easily answered questions go without answer, which reflects on those who experiment, not on those who try to understand. 

Of the two end pieces seen in the photo, the upper one is a different extrusion from the lower one, and does not project closer to the camera than the lower one.

I'd like to thank the EagleWorks team for their help and cooperation.
Title: Re: EM Drive Developments
Post by: aero on 10/21/2014 07:44 pm
http://www.emdrive.com/NWPU2010paper.pdf (http://www.emdrive.com/NWPU2010paper.pdf)

Same paper as before except the original Chinese language version, but this time I went to the end. There exists an abstract in English of another related paper after the reference section. It says "Copper" is used.

Quote
Abstract:Aim.The introduction of the full paper reviews Refs.1 and 2 and points out that we find that the method
of Ref.2,authored by Qiu Xiaoming et al and originally used on a completely different research project,is very effective
for performing our performance calculations,which we explain in sections l。2 and 3.Section l briefs Ref.
1,whose billy author,Roger Shawyer,proposed a theory of microwave propulsion of spacecraft.Sections 2 and 3
explain how we apply Ref.2’8 method;their core consists of:(1)wi凼t}le finite element method。we simulate the
Maxwell’8 field equations for the microwave radiation thruster in the round—table cavity;(2)we acquire the resonant
modes of the round-table cavity and the electromagnetic fields of 1000W inside the round—table cavity;(3)we
analyze the characteristics of the microwave radiation thruster of different cavity s叽ctures and at different resonant
modes;(4)the simulation results,presented in Tables 1 and 2,and their analysis show preliminarily that:(1)
the quality factor and thrust at TE012 mode are the largest;(2)for the incident microwave of 1000W and 2.45GHz,
with copper as the thruster’B material.the largest theoretical thrust based on the classical theory of electrodynamics
is 41 1 and 456mN respectively at TEoll and TEol2 modes.

Of course this introduces another mistake. We are sure that the frequency was not 45 GHz. No, it is spacing, caused me to misread "and 2 . 45 GHz". It is intended to read as "and 2.45 GHz", which is right.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 07:49 pm
http://www.emdrive.com/NWPU2010paper.pdf (http://www.emdrive.com/NWPU2010paper.pdf)

Same paper as before except the original Chinese language version, but this time I went to the end. There exists an abstract in English of another related paper after the reference section. It says "Copper" is used.

Quote
Abstract:Aim.The introduction of the full paper reviews Refs.1 and 2 and points out that we find that the method
of Ref.2,authored by Qiu Xiaoming et al and originally used on a completely different research project,is very effective
for performing our performance calculations,which we explain in sections l。2 and 3.Section l briefs Ref.
1,whose billy author,Roger Shawyer,proposed a theory of microwave propulsion of spacecraft.Sections 2 and 3
explain how we apply Ref.2’8 method;their core consists of:(1)wi凼t}le finite element method。we simulate the
Maxwell’8 field equations for the microwave radiation thruster in the round—table cavity;(2)we acquire the resonant
modes of the round-table cavity and the electromagnetic fields of 1000W inside the round—table cavity;(3)we
analyze the characteristics of the microwave radiation thruster of different cavity s叽ctures and at different resonant
modes;(4)the simulation results,presented in Tables 1 and 2,and their analysis show preliminarily that:(1)
the quality factor and thrust at TE012 mode are the largest;(2)for the incident microwave of 1000W and 2.45GHz,
with copper as the thruster’B material.the largest theoretical thrust based on the classical theory of electrodynamics
is 41 1 and 456mN respectively at TEoll and TEol2 modes.


Congratulations on another excellent find.  I posted it at McCulloch's giving you credit.

QUESTION: Have you found any pictures? Any dimensions on the Chinese EM Drive?
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 08:00 pm
How can it be postulated that Evanescent Waves by themselves can solve the closed-system, momentum-conservation problem?

They can't by themselves using classical physics.  One spaceship may transmit an evanescent field to move external small nanosatellites next to it (would not be an interesting form of propulsion, and the center of mass composed by the nanosatellites and the spacecraft system would not accelerate either).  But it cannot move itself just by using Evanescent waves without any external field. 

A spaceship cannot propel itself by using Evanescent Waves any better than it can propel itself using Electromagnetic Fields.  It is a closed system.

A swimmer can swim in the ocean because the ocean water has its own inertia and resists acceleration.  An astronaut cannot propel itself by waving her arms and legs in space.

To enable propulsion one must have an open system: external dark matter, external fields: like the Earth's magnetic field, an external aether, even consideration of the external quantum vacuum, etc.  But certainly not just Evanescent Fields by themselves that are self generated and only interacting in a closed system.

To avoid this confusion one must rely on conservation principles: conservation of momentum, conservation of energy, and variational principles.
Title: Re: EM Drive Developments
Post by: JasonAW3 on 10/21/2014 08:46 pm
We now have separate confirmation in both China and the USA that thrust force measurements are related to the TRANSVERSE ELECTRIC modes, since their mode shape result in greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes.

This is a further challenge to explaining the measured thrust forces in these EM Drives as resulting from the magnetic field interacting with the Earth's magnetic field or with other magnetic fields (like the magnetic damper)


It also explains why NASA Eagleworks explored resonance for the mode TE012

It almost seems that the Magnetic field is interacting with Space itself in this case, much how gravity distorts spacethis configuration of a magnetic field appeasrs to be doing the same thing.

This is my thinking:

It is the electric field modes (not the magnetic modes) that show the greater Q and greater thrust, not the other way around.  There is no such thing as "thrust" using classical Maxwell's equations.  It is a closed system.  The magnetic field vectors from both bases point towards the center.  There is no net magnetic force on the center of mass using classical Maxwell's equations.

If on the other hand, one uses non-classical physics it doesn't follow that the force must come from the magnetic field, on the contrary, for example McCulloch's explanation of inertial changes due to Unruh radiation, it is the photons inertia that matters.

Great...  Quantum Physics again....  Time for the head on top of my shoulders to go explody!
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/21/2014 08:54 pm
To enable propulsion one must have an open system: ... an external aether ...

Can I vote for aether?
Title: Re: EM Drive Developments
Post by: aero on 10/21/2014 10:01 pm
Quote
QUESTION: Have you found any pictures? Any dimensions on the Chinese EM Drive?

No - Closest I have came is word description in the numerical calculation paper. He says that the diameter of the small end is just smaller than the wavelength of the fundamental frequency. Same thing Shawyer said in his email. Then

Quote
Fa=Fa1-Fa2-Fa3cosθ. In order to obtain the largest thrust, the design of the cavity requires Fa1/Fa2 to be the largest, Fa3/Fa1 to be the smallest, so Fa≈Fa1-Fa2.


where Fa1 = w_big, Fa2=w_small and Fa3 cos (theta) = height/length/or Prof. M's variable, s .

But that doesn't make a lot of sense to me. Of course with that geometry once you choose an optimum value of Fa2 of course thrust diminishes if you increase it? I guess.
Title: Re: EM Drive Developments
Post by: Rodal on 10/21/2014 10:15 pm
Fa=Fa1-Fa2-Fa3cosθ. In order to obtain the largest thrust, the design of the cavity requires Fa1/Fa2 to be the largest, Fa3/Fa1 to be the smallest, so Fa≈Fa1-Fa2.


where Fa1 = w_big, Fa2=w_small and Fa3 cos (theta) = height/length/or Prof. M's variable, s .

But that doesn't make a lot of sense to me. Of course with that geometry once you choose an optimum value of Fa2 of course thrust diminishes if you increase it? I guess.
[/quote]

Thank you for having the great patience to read through that translation. 

Me primitivo-man-without AutoCAD not enjoy reading that translation and not much patience to read it. 
I have difficulty in continuing to read when things like the ones you point out don't make sense  (notice that the statement Fa2 increase diminishes thrust is the opposite of what the paper says in another place_
So much thankful to you for translating it to us and giving us the important points  ;)
Title: Re: EM Drive Developments
Post by: aero on 10/21/2014 10:47 pm
Does anyone reading this have a contact with the NASA Eagleworks people knowledgeable about the resonant cavity? Best bet to get accurate dimensions might be to just ask someone who knows.

Alternatively someone could calculate the wavelength of the fundamental frequency for all of the devices for which we have or need dimensions, then use the big/little ratio from Shawyer where we have actual big dimension to get a ratio. See how that ratio maps into our estimates for all of the devices. We do know the slope/taper accurately from the photos that we have. That should help guessing the length. By that I mean, since the taper/slope can be accurately picked off the photos, and for Shawyer at least, where the Big is known then we can use the height to calculate the small or the small to calculate the height, using the measurements least susceptible to error. We can also use this technique to confirm the accuracy of our measurements since they all must fit the equation:

Small = big - taper * height  and height = (big-small)/taper
Title: Re: EM Drive Developments
Post by: zen-in on 10/22/2014 12:13 am
We now have separate confirmation in both China and the USA that thrust force measurements are related to the TRANSVERSE ELECTRIC modes, since their mode shape result in greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes.

This is a further challenge [ and a hint ] to explaining the measured thrust forces in these EM Drives as resulting from the magnetic field interacting with the Earth's magnetic field or with other magnetic fields (like the magnetic damper)


It also explains why NASA Eagleworks explored resonance for the mode TE012

EDIT:  Electric and magnetic fields are two interrelated aspects of the same electromagnetic tensor; the split of this tensor into electric and magnetic fields depends on the relative velocity of the observer and charge.  Therefore my original wording (challenge to thought process) should be changed to "challenge and hint".  It is a powerful hint to make us think as to what is going on.


The electromagnetic fields, standing wave or otherwise,  inside the cavity would not be expected to have any interaction with the geomagnetic field.   First they are AC and second there is no current flowing in the air.    So the claimed em mode is unrelated to any possible geomagnetic attraction.  There would have to be a DC current loop somewhere for the anomalous thrust to be caused by interaction with the geomagnetic field.    I also don't think the cavity's shape is the reason for the high Q and resonance at specific frequencies.   It isn't a waveguide.  It is just a shielded box.   The resonant frequency is determined by the loop dimensions at the feedpoint or by a 1/4 λ length of Cu fastened to the box at one end.   Here is a diagram of a cavity filter used in radio communication.   The length of the inner Cu rod determines the resonant frequency.   The cavity's size has little effect on the resonant frequency since changing the size only changes the parasitic capacitance by small amounts.

One of the drawings of the em-drive device shows an inner can shape at the small end.   It's possible that is what determines the resonant frequency and high Q.   It would have to be made from Cu and be electrically connected to the cavity at one end.
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 12:37 am
We now have separate confirmation in both China and the USA that thrust force measurements are related to the TRANSVERSE ELECTRIC modes, since their mode shape result in greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes.

This is a further challenge [ and a hint ] to explaining the measured thrust forces in these EM Drives as resulting from the magnetic field interacting with the Earth's magnetic field or with other magnetic fields (like the magnetic damper)


It also explains why NASA Eagleworks explored resonance for the mode TE012

EDIT:  Electric and magnetic fields are two interrelated aspects of the same electromagnetic tensor; the split of this tensor into electric and magnetic fields depends on the relative velocity of the observer and charge.  Therefore my original wording (challenge to thought process) should be changed to "challenge and hint".  It is a powerful hint to make us think as to what is going on.


The electromagnetic fields, standing wave or otherwise,  inside the cavity would not be expected to have any interaction with the geomagnetic field.   First they are AC and second there is no current flowing in the air.    So the claimed em mode is unrelated to any possible geomagnetic attraction.  There would have to be a DC current loop somewhere for the anomalous thrust to be caused by interaction with the geomagnetic field.    I also don't think the cavity's shape is the reason for the high Q and resonance at specific frequencies.   It isn't a waveguide.  It is just a shielded box.   The resonant frequency is determined by the loop dimensions at the feedpoint or by a 1/4 λ length of Cu fastened to the box at one end.   Here is a diagram of a cavity filter used in radio communication.   The length of the inner Cu rod determines the resonant frequency.   The cavity's size has little effect on the resonant frequency since changing the size only changes the parasitic capacitance by small amounts.

One of the drawings of the em-drive device shows an inner can shape at the small end.   It's possible that is what determines the resonant frequency and high Q.   It would have to be made from Cu and be electrically connected to the cavity at one end.

<< I also don't think the cavity's shape is the reason for the high Q and resonance at specific frequencies.>>

Thank your for the input.  The following considerations, however, point towards a resonating cavity where the shape governs the mode shapes:

1) Both NASA Eagleworks (Brady et.al ) and the Chinese University (Juan Yang et.al.) studied the electromagnetic modes of the cavity with Finite Element Analysis.  Both of them describe the resonant modes with the standard terminology used for transverse modes in resonating cavities (linearly polarized transverse to the plane of incidence): transverse magnetic (TM) and transverse (TE) modes accompanied by numbers.  For a cylindrical resonating cavity the first number in the subscript is the azimuthal mode number. The second number is the radial mode number. The radial mode number minus one is the number of nodes in the radial variation of Ez. The third number is the longitudinal mode number. For example: TE012 = azimuthal = 0 (it is an azimuthally symmetric mode), radial =1 (no variation of Ez), longitudinal =2 (longitudinal mode 2, for constant field it would be zero).  This detailed description of the mode shapes by NASA Eagleworks and by the Chinese is telling us that this is indeed a resonating cavity where the shape of the cavity governs  the mode shape.

See, for example http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html for a closed-form solution for a truncated cone with hemispherical ends, where the resonant modes are completely determined by the cavity shape, by the medium inside the cavity and by the material of the cavity.  This completely determines the TM and TE resonant modes and the Q.

2) In your explanation, you are proposing a different kind of resonant cavity than the one modeled by Finite Element Analysis by NASA Eagleworks and by the Chinese.  I don't understand why the Chinese and NASA Eagleworks would conduct a Finite Element Analysis modeling the drive as being a resonant cavity where Q and the resonant modes are completely due to the cavity shape if they would instead be using the type of resonator you are describing.

I attach NASA Eagleworks COMSOL Finite Element analysis of the resonant spectrum (amplitude vs frequency) at the top (and the S21 plot at the bottom) and the Finite Element Analysis of the electric field for the truncated cone.

Quoting the NASA report, regarding the presence of the RF antennas:

<<The RF drive antenna is the lower loop antenna seen in the wireframe representation of the assembly. An S11 (reflected power) plot prediction from COMSOL® is evaluated against the actual S11 output as measured by a vector network analyzer (VNA) connected to the lower antenna. Note that, in practice, a second (RF sense) antenna is present in the thruster in anticipation of implementing a phase lock loop (PLL) control approach to maintain resonance conditions over time. With the presence of the second RF sense antenna, COMSOL® can be used to provide an S21 (two-port delivered power) plot prediction that can also be evaluated against the actual S21 plot from a VNA connected to both the drive and sense antenna.>>
Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 03:10 am
You know, this whole thing doesn't make any sense.

For an ideal photon rocket F=P/c, = 3.3356E-09   Newtons per watt and for the EM thruster, it is F ~= P*Q/c. For the case, for example, of 850 watts with Q = 5900, P*Q/c = 16.7 mN, compared to the measured value of 16 mN. (They are not all that close but the range is 0.2 to 2, discounting Brady b" case with the Chinese cases approaching twice the total momentum of all the photons --- per second.

So the complete total of all the photons in the cavity are giving their momentum up, and more, to thrust every second. How can that possible make sense. And even don't look at the energy.

Unruh waves can't come close to making a big enough change in mass to cause lost mass to exceed the existing mass. (mi=m(1-L/4T)) For this to work, T would need to be equal to or less than L/4.

There is one way of course but if I say "Tachyons," I'll likely be banned.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/22/2014 05:34 am
Quote
So the complete total of all the photons in the cavity are giving their momentum up, and more, to thrust every second. How can that possible make sense. And even don't look at the energy.

Unruh waves can't come close to making a big enough change in mass to cause lost mass to exceed the existing mass. (mi=m(1-L/4T)) For this to work, T would need to be equal to or less than L/4.

There is one way of course but if I say "Tachyons," I'll likely be banned.

Then don't say 'Tachyons.'

I've has idle thoughts about a long shot possible resolution to this problem these past couple of days.

Muletron posted a video a couple days ago giving sort of a capsule history of research into subatomic particles.  The part that intrigued me was where the narrator put forth a chart showing a dozen plus subatomic particles discovered in the search for the Higgs boson.  His attitude - which I'd seen before in print - was one of embarrassed dismissal.  The attitude being these particles are a sort of unprofitable sideline, not worth detailed investigation.    Yet I wonder...might not one or more varieties of these particles hold part of the solution to this drive?  They are elementary 'building block' type critters - maybe certain rules don't fully apply to them?  Maybe they're attracted to photons? 

Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 07:44 am
You see, the problem is that there is more momentum being exchanged with something than the total momentum that exists within the cavity. Even if all of the phonon momentum of all of the resonating photons within the cavity were "transferred" to dark matter, there would not be enough momentum available to produce the measured thrust, particularly in the cases of the Chinese results and Shawyer b" and just barely enough in Shawyer a". And if all the resonating momentum of all the photons departed the cavity, what is there to keep resonating?

If the momentum is transferred to the quantum vacuum virtual plasma, well, there might be enough for Brady's tests data to be satisfied but it doesn't solve the problem of understanding the Jaun and Shawyer cases. There is just not enough momentum in existence in the cavity. Transfer it all and you've transferred only half enough.
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 12:53 pm
You know, this whole thing doesn't make any sense.

For an ideal photon rocket F=P/c, = 3.3356E-09   Newtons per watt and for the EM thruster, it is F ~= P*Q/c. For the case, for example, of 850 watts with Q = 5900, P*Q/c = 16.7 mN, compared to the measured value of 16 mN. (They are not all that close but the range is 0.2 to 2, discounting Brady b" case with the Chinese cases approaching twice the total momentum of all the photons --- per second.

So the complete total of all the photons in the cavity are giving their momentum up, and more, to thrust every second. How can that possible make sense. And even don't look at the energy.

Unruh waves can't come close to making a big enough change in mass to cause lost mass to exceed the existing mass. (mi=m(1-L/4T)) For this to work, T would need to be equal to or less than L/4.

There is one way of course but if I say "Tachyons," I'll likely be banned.

Momentum change when a photon hits the wall is a factor of 2 times the magnitude of the photon's momentum (due to change in direction).

Assuming no losses at the wall due to the collision, (h is Planck's constant, c is speed of light, f is frequency of photon,  M is the effective mass of the wall):

Magnitude of photon's momentum before and after it hits the wall = h*f/c

Momentum change at the wall (due to change in direction): +h*f/c - (- h*f/c) = 2*h*f/c

The wall gains a momentum of 2*h*f/c

The wall gains a kinetic energy of ((2*h*f/c)^2)/(2M) = (2/M) * (h*f/c)^2

Did you include those factors of 2 ?

I think that Shawyer included the factor of 2 in his equation:

Force = (2 * PowerInput * Q /c ) * DesignFactor

If you don't include those factors of 2, you are essentially assuming a completely inelastic collision where all the photons get their energy totally dissipated at the wall and that there is no photon whatsoever bouncing off the wall again.

The index of refraction of copper is orders of magnitude greater than one (taking into account that the microwave wavelength is hundreds of thousands of micrometers, hence way to the right off the scale in the graph below).  Therefore the great majority of the photons (several orders of magnitude greater) are reflected off the wall, and very few photons have their energy dissipated at the wall. 

Hence it is much more valid to assume a factor of 2 (F ~= 2*P*Q/c) rather than a factor of 1 (F ~= P*Q/c).

Even for Solar Sails (not as reflective) it is usual to assume a factor of 1.8 instead of 1, which would give in this case F ~= 1.8*P*Q/c instead of P*Q/c.

(http://refractiveindex.info/legacy/figures/figures_RI/n_METALS_Copper_Palik.png)
Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 02:33 pm
Quote
Transfer it all and you've transferred only half enough.

No. I did not use a factor of 2. If I double momentum then transfer it all, I've transferred just enough. But if it bounces off the wall then how does it transfer outside the cavity?
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 02:46 pm
Quote
Transfer it all and you've transferred only half enough.

No. I did not use a factor of 2. If I double momentum then transfer it all, I've transferred just enough. But if it bounces off the wall then how does it transfer outside the cavity?

Concerning acceleration of the center of mass of the drive, that's the whole problem here again: it the problem is analyzed as a closed system using Classical Physics (Maxwell's equation with Abraham's symmetric stress tensor or with Minkowski's asymmetric stress tensor including hidden momentum) there is no acceleration of the center of mass whatsoever.

If one assumes McCulloch's model, the change in momentum for the given geometrical ratio of Length of Cavity to Diameter ratio is not small enough to produce the required acceleration for Unruh wave change of inertia modification. Although it is interesting that in Shawyer's superconducting design the length is now much smaller (compared to the other dimensions) and therefore this ratio is much closer to the one required.  For McCulloch's formulation one would have to perform: 1) a 3 dimensional analysis to properly take into account the contribution from the cone's revolving surface walls  and 2) the energy spectrum of the Unruh waves to settle this issue.

There are still other possible explanations to settle this problem:

1) possible amplification of response due to measurement: certainly this is the case when using inverted pendulums (used at NASA Eagleworks and China experiments).

2) the EM Drives may be producing a moment (around the center of mass) but not an acceleration of the center of mass. Hence if deployed in space they would not accelerate the EM Drive's center of mass.


I have been advocating for using a simple Cavendish style-measurement with oil damping (instead of magnetic damping) to settle this issue.  Brady's NASA report concludes with a sentence that JPL, Glenn and John Hopkins have proposed further measurements, but only John Hopkins has a Cavendish style-type of measurement while the other two (JPL and Glenn) are offering to use inverted pendulums again.  I wish we would get a Cavendish-type measurement (as performed by Brito Marini and Galian to nullify the MLT-type drive) at John Hopkins as soon as possible.

The inverse-square law of gravitation and the Casimir force measurements were performed with Cavendish-type experiments and not with inverted pendulums.

This is one thing (in addition to exercise and mixologists) where kernosabe John and I agree: the need to perform these experiments with a classical type of experiment (self-contained-battery-operated unit in a Cavendish balance) instead of inverted pendulums (NASA and China) or non-Cavendish balances (Shawyer).
Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 03:32 pm
Yes, we need more and better data. But if we assume the current data is in error then we've wasted 163 pages of discussion. If the current data is right then there is not enough momentum in the system provide the measured external thrust.

Who knows of another mechanism to generate external force without momentum transfer or a reactive surface?

Casimir effect but that is internal, I've never heard of an external Casimir effect. Maybe the Unruh effect sets up a perfectly conducting surface just nanometers from the cavity ends. That could generate the outside pressure imbalance that we need.
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 03:43 pm
Yes, we need more and better data. But if we assume the current data is in error then we've wasted 163 pages of discussion. If the current data is right then there is not enough momentum in the system provide the measured external thrust.

Who knows of another mechanism to generate external force without momentum transfer or a reactive surface?

Casimir effect but that is internal, I've never heard of an external Casimir effect. Maybe the Unruh effect sets up a perfectly conducting surface just nanometers from the cavity ends. That could generate the outside pressure imbalance that we need.
Well, concerning transferring momentum to the wall, it makes more sense to assume complete reflection rather than complete dissipation.  If you have a mass swinging from a pendulum elastically hitting a wall you transfer kinetic energy to the wall every time you hit the wall.  However if the swinging mass is made of completely inelastic play-doh, it will hit the wall once and that's it. [And yes perpetual motion people: I'm aware that we have to conserve energy and hence have some losses with every impact. Q is not infinite, it only ranges from 7000 to 50000 which is way smaller than infinite]

(http://resource.rockyview.ab.ca/rvlc/physics30_BU/images/m2/p30_m2_027a_l.jpg)

(http://resource.rockyview.ab.ca/rvlc/physics30_BU/images/m2/p30_m2_030_l.jpg)

(http://resource.rockyview.ab.ca/rvlc/physics30_BU/images/m2/p30_m2_031_l.jpg)
Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 04:06 pm
Maybe "somehow there is"  a perfectly conducting surface set up just nanometers from the cavity ends. That could generate the outside pressure imbalance that we need.

Could the ionized air and electrons from the wall interacting with the RF wave electric and magnetic fields do something like that?

A mechanism like that would solve our momentum transfer problem as Casimir effect is an accepted phenomena and higher Q could conceivably force the "pseudo conductor plate of ionized something" closer to the wall. Decreasing plate separation increases Casimir force. That also fits.

Of course their could be an oxidation layer on the copper, too.
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 04:38 pm
Maybe "somehow there is"  a perfectly conducting surface set up just nanometers from the cavity ends. That could generate the outside pressure imbalance that we need.

Could the ionized air and electrons from the wall interacting with the RF wave electric and magnetic fields do something like that?

A mechanism like that would solve our momentum transfer problem as Casimir effect is an accepted phenomena and higher Q could conceivably force the "pseudo conductor plate of ionized something" closer to the wall. Decreasing plate separation increases Casimir force. That also fits.

Of course their could be an oxidation layer on the copper, too.
No, there is no real and no virtual perfectly conducting wall a nanometer away from the cavity. No,  ionized air and electrons cannot form such a "virtual wall" for a Casimir type effect.  Not for a classic Casimir effect and much less for a dynamic Casimir effect.   Ions in air cannot form something acting as a wall for the Casimir effect purpose.

Were one to postulate ionized air discharge, a corona discharge essentially resulting in electrohydrodynamic thrust would be more likely.  An opposite force to the direction of discharge acting at the location where the corona discharge is taking place.  Perhaps at the gaps of the cupric structure: more likely at the gaps between the flat bases of the truncated cone and its round surface.

Too bad that none of these experiments seem to have been conducted in a vacuum, so that we cannot fully eliminate this.

(http://lae.mit.edu/wordpress2/wp-content/uploads/2013/04/figure1-300x132.png)
Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 04:51 pm
Maybe "somehow there is"  a perfectly conducting surface set up just nanometers from the cavity ends. That could generate the outside pressure imbalance that we need.

Could the ionized air and electrons from the wall interacting with the RF wave electric and magnetic fields do something like that?

A mechanism like that would solve our momentum transfer problem as Casimir effect is an accepted phenomena and higher Q could conceivably force the "pseudo conductor plate of ionized something" closer to the wall. Decreasing plate separation increases Casimir force. That also fits.

Of course their could be an oxidation layer on the copper, too.
No, there is no real and no virtual perfectly conducting wall a nanometer away from the cavity. No,  ionized air and electrons cannot form such a "virtual wall" for a Casimir type effect.  Not for a classic Casimir effect and much less for a dynamic Casimir effect.   Ions in air cannot form something acting as a wall for the Casimir effect purpose.

Were one to postulate ionized air discharge, a corona discharge essentially resulting in electrohydrodynamic thrust would be more likely.  An opposite force to the direction of discharge acting at the location where the corona discharge is taking place.

But a counter argument.

No, there cannot be an external force on the cavity without momentum exchange or another mechanism. The probability, as we understand physics, for thrust from this device equals the probability of a wall of electrons forming just outside the inner surface of the copper end surfaces setting up a Casimir effect.

Thereby solving one impossible situation by substituting another.
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 05:06 pm
<<When a current passes between two electrodes — one thinner than the other — it creates a wind in the air between. If enough voltage is applied, the resulting wind can produce a thrust without the help of motors or fuel.
This phenomenon, called electrohydrodynamic thrust — or, more colloquially, “ionic wind” — was first identified in the early 20th century. ...Some researchers have theorized that ionic thrusters, if used as jet propulsion, would be extremely inefficient, requiring massive amounts of electricity to produce enough thrust to propel a vehicle.
Now researchers at MIT have run their own experiments and found that ionic thrusters may be a far more efficient source of propulsion than conventional jet engines. In their experiments, they found that ionic wind produces 110 newtons of thrust per kilowatt, compared with a jet engine’s 2 newtons per kilowatt. The team has published its results in the Proceedings of the Royal Society.
Steven Barrett, an assistant professor of aeronautics and astronautics at MIT, envisions that ionic wind may be used as a propulsion system for small, lightweight aircraft. In addition to their relatively high efficiency, ionic thrusters are silent, and invisible in infrared, as they give off no heat — ideal traits, he says, for a surveillance vehicle.
...
To measure an ion thruster’s efficiency, Barrett and Masuyama built a similarly simple setup, and hung the contraption under a suspended digital scale. They applied tens of thousands of volts, creating enough current draw to power an incandescent light bulb. They altered the distance between the electrodes, and recorded the thrust as the device lifted off the ground. Barrett says that the device was most efficient at producing lower thrust — a desirable, albeit counterintuitive, result.
“It’s kind of surprising, but if you have a high-velocity jet, you leave in your wake a load of wasted kinetic energy,” Barrett explains. “So you want as low-velocity a jet as you can, while still producing enough thrust.” He adds that an ionic wind is a good way to produce a low-velocity jet over a large area.
Getting to liftoff
Barrett acknowledges that there is one big obstacle to ionic wind propulsion: thrust density, or the amount of thrust produced per given area. Ionic thrusters depend on the wind produced between electrodes; the larger the space between electrodes, the stronger the thrust produced. That means lifting a small aircraft and its electrical power supply would require a very large air gap. Barrett envisions that electrodynamic thrusters for aircraft — if they worked — would encompass the entire vehicle.
Another drawback is the voltage needed to get a vehicle off the ground: Small, lightweight balsa models require several kilovolts. Barrett estimates a small craft, with onboard instrumentation and a power supply, would need hundreds or thousands of kilovolts.
“The voltages could get enormous,” Barrett says. “But I think that’s a challenge that’s probably solvable.” For example, he says power might be supplied by lightweight solar panels or fuel cells. Barrett says ionic thrusters might also prove useful in quieter cooling systems for laptops.
Ned Allen, chief scientist and senior fellow at Lockheed Martin Corp., says that while ionic thrusters face serious drawbacks — particularly for aerospace applications — the technology “offers nearly miraculous potential.”
“[Electrohydrodynamic thrust] is capable of a much higher efficiency than any combustion reaction device, such as a rocket or jet thrust-production device,” Allen says. Partly for this reason, Allen says Lockheed Martin is looking into the technology as a potential means of propulsion.
“Efficiency is probably the number one thing overall that drives aircraft design,” Barrett says. “[Ionic thrusters] are viable insofar as they are efficient. There are still unanswered questions, but because they seem so efficient, it’s definitely worth investigating further.”>>

http://lae.mit.edu/ehd/


(http://lae.mit.edu/wordpress2/wp-content/uploads/2013/04/figure1-300x132.png)
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 05:15 pm
MIT Aeronautics and Astronautics (Prof. Barrett and Masuyama, Proceedings of the Royal Society) Ionic wind maximum SPECIFIC FORCE= 110 N/kW

Shawyer SPECIFIC FORCE = 0.02 to 0.4 N/kW

IonicWind/ShawyerEMDrive specific force ratio = 5500 to 275 times

So there is plenty of room (orders of magnitude) for these EMDrives measured thrust to be due to small amounts of Ionic Wind escaping from the gaps between the flat bases of the truncated cone and the curved cone surface.

https://www.youtube.com/watch?v=WfrqzBGPnwE
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 05:29 pm
Paper by Prof. Barrett and Masuyama in the proceedings of the Royal Society, containing theory, equations and experiments:

http://royalsocietypublishing.org/content/469/2154/20120623


(http://royalsocietypublishing.org/content/royprsa/469/2154/20120623/F4.medium.gif)

(http://royalsocietypublishing.org/content/royprsa/469/2154/20120623/F5.medium.gif)

(http://royalsocietypublishing.org/content/royprsa/469/2154/20120623/F6.medium.gif)

(http://royalsocietypublishing.org/content/royprsa/469/2154/20120623/F7.medium.gif)
Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 05:33 pm
There is also information supporting existence of a conductive layer next to the end walls of the cavity.

http://www.chee.uh.edu/sites/chbe.egr.uh.edu/files/faculty/economou/jap_sheath.pdf (http://www.chee.uh.edu/sites/chbe.egr.uh.edu/files/faculty/economou/jap_sheath.pdf)

And look at the photo of the flight thruster. I don't see any place for leaks in the axial direction.

 Mean specific thrust = 326mN/kW

http://www.emdrive.com/flightprogramme.html (http://www.emdrive.com/flightprogramme.html)
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 05:37 pm
...

 I don't see any place for leaks in the axial direction.

...

Look at direction of thrust force with respect to the ionic air:


(http://royalsocietypublishing.org/content/royprsa/469/2154/20120623/F1.medium.gif)

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=616602;image)

I can envision the "upper electrode" being formed by the perimeter edge of the the flat base of cone and the "insulation" taking place at the gap between the flat base and the round surface of the truncated cone.

Thrust would be greater on the larger base due to its larger perimeter.

There are all those bolts directed in the axial direction of the cone.  Corona discharge could take place at those bolts/and/or/at the perimeter edge of the flat base. 

Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 05:49 pm
What you are saying is that these EM thruster devices need to be checked with a smoke trails, like air flow in a wind tunnel is highlighted. Hold a lighted punk stick next to it and turn the device on.

Wouldn't their be some time delay between power on/off and thrust on and off?

Does anyone want to take a crack at estimating the dimensions of the flight thruster. It operated at 3.85GHz and weighed 2.92 Kg. That is a new operating frequency data point for us if we can get dimension. If nothing else, we should be able to get the taper angle pretty accurately, as well as the ratios of big/little and big/height.
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 05:54 pm
What you are saying is that these EM thruster devices need to be checked with a smoke trails, like air flow in a wind tunnel is highlighted. Hold a lighted punk stick next to it and turn the device on.

Wouldn't their be some time delay between power on/off and thrust on and off?
Have to think about what would a time constant involved in delay depend on.  The electric effect is practically instantaneous.  Momentum transfer has to do with hydrodynamics.  There is no heat capacity and thermal difussivity involved like in a thermal effect.  Time constant could depend on Reynolds number, hence viscosity, but viscosity of air is low. Also, speed of sound in air is 343 metres per second, which is pretty fast for these considerations.

What is the time delay for the craft shown in this video?  Seems to take off in an impulsive manner:


https://www.youtube.com/watch?v=WfrqzBGPnwE
Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 06:19 pm
The time delay is not noticeable. I don't know if the time delay difference between this device and the EM thrusters could be detected. I don't think it can be with the data we have available to us.
Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 06:20 pm
...

Does anyone want to take a crack at estimating the dimensions of the flight thruster. It operated at 3.85GHz and weighed 2.92 Kg. That is a new operating frequency data point for us if we can get dimension. If nothing else, we should be able to get the taper angle pretty accurately, as well as the ratios of big/little and big/height.

Please provide a link for this " flight thruster.. operated at 3.85GHz and weighed 2.92 Kg.", and if possible attach a picture.  Thanks

here - http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275021#msg1275021 (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275021#msg1275021)
Title: Re: EM Drive Developments
Post by: zen-in on 10/22/2014 06:52 pm
The time delay is not noticeable. I don't know if the time delay difference between this device and the EM thrusters could be detected. I don't think it can be with the data we have available to us.

Actually the time delay is visible in these two plots of thrust data vs time.   The first one is from Shawyer's 2008 paper.   His 2013 and 2014 IAC papers don't have this kind of raw data.   Both the up and down thrust roughly follow an exponential rise after power is applied and there is continued acceleration after the power is turned off.

The second plot is from the JSC paper - Brady, White, et al.  This also has a roughly exponential rise and continued thrust after RF power is turned off until the Cal pulse wipes it out.

Both experiments show the signature of a thermal effect.  As in a Crookes radiometer.
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 06:57 pm
The time delay is not noticeable. I don't know if the time delay difference between this device and the EM thrusters could be detected. I don't think it can be with the data we have available to us.

Actually the time delay is visible in these two plots of thrust data vs time.   The first one is from Shawyer's 2008 paper.   His 2013 and 2014 IAC papers don't have this kind of raw data.   Both the up and down thrust roughly follow an exponential rise after power is applied and there is continued acceleration after the power is turned off.

The second plot is from the JSC paper - Brady, White, et al.  This also has a roughly exponential rise and continued thrust after RF power is turned off until the Cal pulse wipes it out.

Both experiments have a thermal effect signature.

Yes, some kind of a delay but not thermal for NASA Eagleworks. Around page 30 to 40 of this thread I calculated the thermal time delay based on the thermal diffusivity (thermal capacity and thermal conductivity) for the NASA Eagleworks experiments and ruled out the time delay and time decay as due to thermal effects because the Fourier time due to thermal effects is much longer than the ~2 second delay in the NASA Eagleworks experiments in the pulse rise from the baseline.

The exponentially decaying rise after the initial 2 sec pulse may indeed be a thermal effect.  Maybe related to their "baseline problem due to the magnetic damper interaction with the power cable..."

Ionic wind time delay ?

Paul March had also though about thermal effects and wrote about it.  It is interesting that while these researchers can rule out thermal effects (based on standard heat transfer texts) the theory of ionic wind has not been written until recently.  Perhaps nobody has computed or ruled out ionic wind, really...
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/22/2014 07:03 pm
What about the gauge constant for the springs?  How far does it have to move for the force to be read ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 07:05 pm
What about the gauge constant for the springs?  How far does it have to move for the force to be read ?

<<Displacement of the pendulum arm is measured via a Linear Displacement Sensor (LDS). The primary LDS components consist of a combined laser and optical sensor on the fixed structure and a mirror on the pendulum arm. The LDS laser emits a beam which is reflected by the mirror and subsequently detected by the optical sensor. The LDS software calculates the displacement (down to the sub-micrometer level) based upon the beam reflection time. Prior to a test run data take, the LDS is positioned to a known displacement datum (usually 500 micrometers) via mechanical adjustments to its mounting platform. Gross adjustments are performed via set screws. Fine adjustments are performed using manually-operated calibrated screw mechanisms and a remotely controlled motorized mechanism that can be operated with the chamber door closed and the chamber at vacuum. The remote adjustment capability is necessary since the LDS datum will change whenever a change to the test facility environment affects the roll-out table or the chamber – e.g., whenever the chamber door is closed or latched and whenever the chamber is evacuated. Once the LDS displacement is adjusted in the final test environment, further adjustment between test run data takes is usually not required.>>  Brady et.al. page 3
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/22/2014 07:07 pm
What about the gauge constant for the springs?  How far does it have to move for the force to be read ?

<<Displacement of the pendulum arm is measured via a Linear Displacement Sensor (LDS). The primary LDS components consist of a combined laser and optical sensor on the fixed structure and a mirror on the pendulum arm. The LDS laser emits a beam which is reflected by the mirror and subsequently detected by the optical sensor. The LDS software calculates the displacement (down to the sub-micrometer level) based upon the beam reflection time. Prior to a test run data take, the LDS is positioned to a known displacement datum (usually 500 micrometers) via mechanical adjustments to its mounting platform. Gross adjustments are performed via set screws. Fine adjustments are performed using manually-operated calibrated screw mechanisms and a remotely controlled motorized mechanism that can be operated with the chamber door closed and the chamber at vacuum. The remote adjustment capability is necessary since the LDS datum will change whenever a change to the test facility environment affects the roll-out table or the chamber – e.g., whenever the chamber door is closed or latched and whenever the chamber is evacuated. Once the LDS displacement is adjusted in the final test environment, further adjustment between test run data takes is usually not required.>>

Yes, but how much displacement are we talking about and how long does it take to get there?
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 07:26 pm
What about the gauge constant for the springs?  How far does it have to move for the force to be read ?

<<Displacement of the pendulum arm is measured via a Linear Displacement Sensor (LDS). The primary LDS components consist of a combined laser and optical sensor on the fixed structure and a mirror on the pendulum arm. The LDS laser emits a beam which is reflected by the mirror and subsequently detected by the optical sensor. The LDS software calculates the displacement (down to the sub-micrometer level) based upon the beam reflection time. Prior to a test run data take, the LDS is positioned to a known displacement datum (usually 500 micrometers) via mechanical adjustments to its mounting platform. Gross adjustments are performed via set screws. Fine adjustments are performed using manually-operated calibrated screw mechanisms and a remotely controlled motorized mechanism that can be operated with the chamber door closed and the chamber at vacuum. The remote adjustment capability is necessary since the LDS datum will change whenever a change to the test facility environment affects the roll-out table or the chamber – e.g., whenever the chamber door is closed or latched and whenever the chamber is evacuated. Once the LDS displacement is adjusted in the final test environment, further adjustment between test run data takes is usually not required.>>

Yes, but how much displacement are we talking about and how long does it take to get there?

The displacements are never given in the Brady report.  They only write over and over again about "displacements that correspond to ... microNewtons"

They also write:

<<Immediately prior to a test run data take, the displacement/force relationship is verified by inducing a known force onto the pendulum arm and measuring the displacement. This is done via the electrostatic fins calibration mechanism. This mechanism uses two sets of aluminum fins, one set on the fixed structure and one set on the pendulum arm. The fins overlap without touching. A calibration voltage is applied to the fixed structure fins, which induces a force upon the pendulum arm fins and an associated displacement that is measured by the LDS. The electrostatic fins design provides a constant force over a reasonably large range (between 30-70% overlap), so adjustments to the calibration mechanism between test run data takes and even between test article reconfiguration are usually not required. Calibration of the overlap/force relationship was accomplished using a Scientech SA 210 precision weighing balance (resolution to one micronewton).>>
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 07:33 pm
What about the gauge constant for the springs?  How far does it have to move for the force to be read ?

<<Displacement of the pendulum arm is measured via a Linear Displacement Sensor (LDS). The primary LDS components consist of a combined laser and optical sensor on the fixed structure and a mirror on the pendulum arm. The LDS laser emits a beam which is reflected by the mirror and subsequently detected by the optical sensor. The LDS software calculates the displacement (down to the sub-micrometer level) based upon the beam reflection time. Prior to a test run data take, the LDS is positioned to a known displacement datum (usually 500 micrometers) via mechanical adjustments to its mounting platform. Gross adjustments are performed via set screws. Fine adjustments are performed using manually-operated calibrated screw mechanisms and a remotely controlled motorized mechanism that can be operated with the chamber door closed and the chamber at vacuum. The remote adjustment capability is necessary since the LDS datum will change whenever a change to the test facility environment affects the roll-out table or the chamber – e.g., whenever the chamber door is closed or latched and whenever the chamber is evacuated. Once the LDS displacement is adjusted in the final test environment, further adjustment between test run data takes is usually not required.>>

Yes, but how much displacement are we talking about and how long does it take to get there?

Also Paul March wrote in this thread:  << The Riverhawk C-flex torsion bearing's spring constant is a nominal 0.007 in-Lb/deg., but that varies with the mass load mounted on the torque pendulum arm and selected balance point of the test article mass and its counterbalance mass on the other end of the pendulum arm relative to the torque pendulum’s center of rotation. >>

However this torsional spring constant greatly disagrees with the natural frequency quoted by Paul March. The natural frequency quoted by Paul March indicates a much stiffer spring constant.
Title: Re: EM Drive Developments
Post by: aero on 10/22/2014 07:52 pm
I made a kludge estimate of the Flight thruster dimensions operating at 385 GHz.

w-small =    7.062943185   cm
w-big =   11.02062266   cm
height =    7.114289902   cm

I didn't find anything to use as a reference length so I took Shawyer's statement, "The small end diameters are set just above the cut-off diameter corresponding to the mode and frequency of the design." and made the assumption that he used the same rule here as on the Experimental device, Shawyer a". Then using the wavelength = 2.45 GHz and w_small = 11.1 cm for Shawyer a", simply reduced the small diameter down for frequency ratio. With that and the pixel measurements off the photo, converted all to cm.

The CAD tools should give better pixel lengths but I don't know where to get a better reference length.
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 07:56 pm
I made a kludge estimate of the Flight thruster dimensions operating at 385 GHz.

w-small =    7.062943185   cm
w-big =   11.02062266   cm
height =    7.114289902   cm

...

I am dizzy with all the tests that Shawyer has conducted and with the different names he gives the tested device.  Am I correct that this "flight thruster" is yet a different tested device than the "experimental" and the "demonstrator" Shawyer devices?  Did he test this "flgiht thruster" before or after the other two?

==> Perhaps you can send another e-mail to Shawyer saying that we need actual dimensions of his devices to make sense of the data
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/22/2014 07:59 pm
What about the gauge constant for the springs?  How far does it have to move for the force to be read ?

<<Displacement of the pendulum arm is measured via a Linear Displacement Sensor (LDS). The primary LDS components consist of a combined laser and optical sensor on the fixed structure and a mirror on the pendulum arm. The LDS laser emits a beam which is reflected by the mirror and subsequently detected by the optical sensor. The LDS software calculates the displacement (down to the sub-micrometer level) based upon the beam reflection time. Prior to a test run data take, the LDS is positioned to a known displacement datum (usually 500 micrometers) via mechanical adjustments to its mounting platform. Gross adjustments are performed via set screws. Fine adjustments are performed using manually-operated calibrated screw mechanisms and a remotely controlled motorized mechanism that can be operated with the chamber door closed and the chamber at vacuum. The remote adjustment capability is necessary since the LDS datum will change whenever a change to the test facility environment affects the roll-out table or the chamber – e.g., whenever the chamber door is closed or latched and whenever the chamber is evacuated. Once the LDS displacement is adjusted in the final test environment, further adjustment between test run data takes is usually not required.>>

Yes, but how much displacement are we talking about and how long does it take to get there?

Also Paul March wrote in this thread:  << The Riverhawk C-flex torsion bearing's spring constant is a nominal 0.007 in-Lb/deg., but that varies with the mass load mounted on the torque pendulum arm and selected balance point of the test article mass and its counterbalance mass on the other end of the pendulum arm relative to the torque pendulum’s center of rotation. >>

However this torsional spring constant greatly disagrees with the natural frequency quoted by Paul March. The natural frequency quoted by Paul March indicates a much stiffer spring constant.

A much higher frequency might indicate flex in the arm itself.  (i should explain that I've built quite a few of these type and always found that to be a problem, also used force feedback for zero displacement...but that was a while ago)
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 08:06 pm
....
A much higher frequency might indicate flex in the arm itself.  (i should explain that I've built quite a few of these type and always found that to be a problem, also used force feedback for zero displacement...but that was a while ago)

A higher frequency because you think that the frequency is due to beam bending rather than torsion of the bearing?

In other words, this would mean that the frequency Paul March is referring to would not be the lowest frequency.

I did some calculations some time ago based on known stiffness of the Faztek beams (1.5" by 1.5"), and the bending frequency would be way too high compared to Paul March's stated frequency assuming the inverted pendulum to be effectively clamped by the bearings as a cantilevered beam.  So if the frequency given by Paul March is related to beam bending it would have to be also due to substantial flexibility from the bearings (not providing a perfect clamp).

My impression is that the discrepancy in stiffness is due to the total supported weight.  Paul March stated that the torsional stiffness is dependent on weight.  I used the number given by Paul March, (25 pounds if I remember correctly), but the total weight could be quite different and hence explain the different stiffness value, as the frequency is dependent on the square root of the (torsional) stiffness divided by the mass (moment of inertia) .  Hence the frequency is very dependent on the unknown supported mass, both appearing in the denominator and also affecting the numerator because of the torsional spring constant (unknown dependence on supported mass).
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/22/2014 08:14 pm
....
A much higher frequency might indicate flex in the arm itself.  (i should explain that I've built quite a few of these type and always found that to be a problem, also used force feedback for zero displacement...but that was a while ago)

A higher frequency because you think that the frequency is due to beam bending rather than torsion of the bearing?

In other words, this would mean that the frequency Paul March is referring to would not be the lowest frequency.

I did some calculations some time ago based on known stiffness of the Faztek beams (1.5" by 1.5"), and the bending frequency would be way too high compared to Paul March's stated frequency assuming the inverted pendulum to be effectively clamped by the bearings as a cantilevered beam.  So if the frequency given by Paul March is related to beam bending it would have to be also due to substantial flexibility from the bearings (not providing a perfect clamp).

Tough call w/ all that stuff hanging out there.  Can't see too much in the pictures and not too crazy about the way the chamber is set on.  Could be anything that vibrates.  What were the frequencies ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 08:22 pm
....
A much higher frequency might indicate flex in the arm itself.  (i should explain that I've built quite a few of these type and always found that to be a problem, also used force feedback for zero displacement...but that was a while ago)

A higher frequency because you think that the frequency is due to beam bending rather than torsion of the bearing?

In other words, this would mean that the frequency Paul March is referring to would not be the lowest frequency.

I did some calculations some time ago based on known stiffness of the Faztek beams (1.5" by 1.5"), and the bending frequency would be way too high compared to Paul March's stated frequency assuming the inverted pendulum to be effectively clamped by the bearings as a cantilevered beam.  So if the frequency given by Paul March is related to beam bending it would have to be also due to substantial flexibility from the bearings (not providing a perfect clamp).

Tough call w/ all that stuff hanging out there.  Can't see too much in the pictures and not too crazy about the way the chamber is set on.  Could be anything that vibrates.  What were the frequencies ?
As having done R&D in dynamics work too  I completely agree with your statement "w/ all that stuff hanging out there...not too crazy about the way the chamber is set on."

Concerning the natural frequency, this is exactly what Paul March wrote:

Quote
The natural oscillation period of the pendulum arm when loaded with the RF amplifier, its RF plumbing and the test article was around 4.5 seconds.

So that is

f = 0.222 Hertz

omega = 1.39626 radians / second
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 08:34 pm
And I just verified that Paul March wrote that the supported mass was a maximum of 25 lbm.  That is 11.3398 kgm

The way NASA set-up the experiment "with all that stuff hanging out there" from those 1.5"x1.5" Faztek beams figuring out the rotational mass moment of inertia is also non-trivial.   It is also non-isotropic as it is very different in different orientations of swinging of the inverted pendulum.

Mass moment of inertia not given and very difficult to figure out.  Wonder whether they calculated the inverted torsional pendulum frequencies.  Wonder whether they have a measured  inverted torsional pendulum frequency spectrum for their inverted pendulum with everything set-up (if they do, it was not shown in their report).
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 09:00 pm
What you are saying is that these EM thruster devices need to be checked with a smoke trails, like air flow in a wind tunnel is highlighted. Hold a lighted punk stick next to it and turn the device on.

Wouldn't their be some time delay between power on/off and thrust on and off?
Have to think about what would a time constant involved in delay depend on.  The electric effect is practically instantaneous.  Momentum transfer has to do with hydrodynamics.  There is no heat capacity and thermal difussivity involved like in a thermal effect.  Time constant could depend on Reynolds number, hence viscosity, but viscosity of air is low. Also, speed of sound in air is 343 metres per second, which is pretty fast for these considerations.

What is the time delay for the craft shown in this video?  Seems to take off in an impulsive manner:


https://www.youtube.com/watch?v=WfrqzBGPnwE

Prof. Barrett and Masuyama (MIT) wrote:  <<An ionic wind results from the net momentum gain in a mostly neutral fluid through momentum-transfer collisions with ions in an electric field. When a voltage in excess of the corona inception voltage (V o) is applied across two electrodes with different radii of curvature (re≪rc), a non-uniform electric field with the largest magnitude in the vicinity of the smaller emitter electrode ignites a corona discharge that emits an ion stream. The ions are transported across the interelectrode gap at an average drift velocity vD=μE, where μ is the ion mobility and E is the electric field magnitude, the result of a balance between the electrostatic force owing to the field and the drag force owing to the collisions. The ions are collected at the collector electrode and do not contribute to thrust, but the neutrals that gained energy in the collisions escape the system with net momentum along x, the direction from the emitter towards the collector.>>


So, we know that the average drift velocity is vD=μE  where μ is the ion mobility and E is the electric field magnitude. 

The time constant can be figured out from here:  http://en.wikipedia.org/wiki/Electrical_mobility

μ=(q/kT) D

where D is the diffusion coefficient, which is given by the momentum transfer mean free path and the momentum transfer collision frequency.  These are difficult to estimate.


This paper http://iopscience.iop.org/0370-1328/85/6/327 gives


<<The mobility of positive ions in dry air, which is constant in the range E/p = 45-70 v cm-1 torr-1 and is equal to 2.2 × 10^3 cm2 v-1 sec-1 (at 1 torr and at 20 °c), gradually decreases at higher E/p values. In water vapour the mobility of positive ions was constant over the measured range E/p = 50-90 v cm-1 torr-1 and is equal to 0.61 × 10^3 cm2 v-1 sec-1 (at 20 °c and at 1 torr). In humid air the value of mobility is lower than the value calculated from Blanc's law. This suggests a clustering of ions.>>

EDIT: I have checked vs other references and this reference's abstract is in error, it should read 2.2  cm^2 v-1 sec-1 instead

This book (Ion Mobility Spectrometry, Second Edition, By G.A. Eiceman, Z. Karpas) has it right:  http://goo.gl/0MkCMC
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 09:32 pm
So, assuming the Electric Field in the microwave EM Drive to be 2000 Volts/m  I get:

The average drift velocity for which ions are transported across the inter-electrode gap:

average drift velocity = ((2.2)/(100 cm/m)^2)(cm^2/(Volt*s))*2000 Volts/m
                                = 0.44 m/sec = 17.3 inches / sec = 86.6 ft/min = 0.98 miles/hr

And for 20,000 Volts/m  I get:

average drift velocity = ((2.2)/(100 cm/m)^2)(cm^2/(Volt*s))*20,000 Volts/m
                                = 4.4 m/sec = 173 inches / sec = 866 ft/min = 9.8 miles/hr

using the maximum, electric field calculated by COMSOL at the Teflon dielectric for the Cannae drive, 47,000 Volts/m,  I get:

average drift velocity = ((2.2)/(100 cm/m)^2)(cm^2/(Volt*s))*47,000 Volts/m
                                = 10.3 m/sec = 407 inches / sec = 2035 ft/min = 23 miles/hr

So, the average drift velocity, ranges from a slow breeze like natural convection to a strong wind as from a fan forced convection.

Ionic wind being due to the Electric Field, also explains why the measured thrust was (according to both NASA and China) due to the (TE) transverse electric modes of cavity oscillation (rather than the magnetic modes), where the electric field circulates around the circumferential periphery of the gap between the flat base of the cone and the round surface of the cone.  It is in the circumferential gap around the base (between the base and the cone) that the corona discharge may be taking place.  Also where the protruding bolts holding the base are located.

Magnetic field (B) in blue  Electric Field in red
Title: Re: EM Drive Developments
Post by: Rodal on 10/22/2014 09:57 pm
It is interesting that there have been confusions about non-classical physics [coupling between electromagnetism and gravity] to explain the ionic wind:

Prof. Barrett (MIT) writes:

<<Brown initially attributed the observed thrust force to a coupling between electromagnetism
and gravity. Despite the faulty understanding of the physics, Brown had conceived of the ‘lifter’
design by the 1950s, consisting of a thin wire emitter separated from an aluminium foil collector
with a lightweight non-conducting frame [8]. The concept of ionic wind was associated with EHD
thrust as early as 1961, when Cheng’s [9] one-dimensional model predicted a thrust that varied as
the square of pressure. Christenson & Moller [4] developed an analytical model starting from the
Navier–Stokes equations, whose predictions were confirmed by experiments using pointed pin
emitters. The current density was seen to vary as j ∝ V(V − Vo), in agreement with the current
output for corona discharges.>>
Title: Re: EM Drive Developments
Post by: zen-in on 10/22/2014 10:05 pm
The time delay is not noticeable. I don't know if the time delay difference between this device and the EM thrusters could be detected. I don't think it can be with the data we have available to us.

Actually the time delay is visible in these two plots of thrust data vs time.   The first one is from Shawyer's 2008 paper.   His 2013 and 2014 IAC papers don't have this kind of raw data.   Both the up and down thrust roughly follow an exponential rise after power is applied and there is continued acceleration after the power is turned off.

The second plot is from the JSC paper - Brady, White, et al.  This also has a roughly exponential rise and continued thrust after RF power is turned off until the Cal pulse wipes it out.

Both experiments have a thermal effect signature.

Yes, some kind of a delay but not thermal for NASA Eagleworks. Around page 30 to 40 of this thread I calculated the thermal time delay based on the thermal diffusivity (thermal capacity and thermal conductivity) for the NASA Eagleworks experiments and ruled out the time delay and time decay as due to thermal effects because the Fourier time due to thermal effects is much longer than the ~2 second delay in the NASA Eagleworks experiments in the pulse rise from the baseline.

The exponentially decaying rise after the initial 2 sec pulse may indeed be a thermal effect.  Maybe related to their "baseline problem due to the magnetic damper interaction with the power cable..."

Ionic wind time delay ?

Paul March had also though about thermal effects and wrote about it.  It is interesting that while these researchers can rule out thermal effects (based on standard heat transfer texts) the theory of ionic wind has not been written until recently.  Perhaps nobody has computed or ruled out ionic wind, really...


It is next to impossible to predict thermal effects if you don't have the device in hand.   There are too many variables and wrong assumptions to be made.   I'm not criticizing your abilities but I think there is just not enough information if you don't have the device and have not done some experiments and data collection to start with.   The thrust waveform does look like a thermal effect.   I would be interested to see what happens if they attached a 25 Watt heating pad to the inside surface of the cone section and applied a 30 Sec power pulse.  The entire cone could just be heating the air around it.  The cone angle appears to be about 30 degrees so about half the momentum of any heated air would generated thrust in the same direction as is claimed for em effects.

I also doubt the conical waveguide theory, which is also based on simulations.   I find it surprising the simulation agrees so closely with their measured result, given the rough construction techniques used.  This science of conical cavity appears to be only known by em-drive researchers, despite the wide application of microwave technology with thousands of companies worldwide actively researching new technologies.   A Google search for "conical cavity" only finds Egan's page which while interesting also disputes the notion that thrust can be generated.   If a search for "cold fusion" were done there would be thousands of hits.
Title: Re: EM Drive Developments
Post by: birchoff on 10/23/2014 12:02 am
Here is the PDF mentioned above.

http://www.emdrive.com/iac2014presentation.pdf

Is there a paper with more details to be published ?
"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?

It was an oral presentation. In addition I am not aware of any video from the conference. that said just looking at the publicly available information the 4 independent organizations could be. SPR (Shawyer's company), The chinese, NASA, Cannae. IF that is correct then the three different countries would be UK, China, and US.
Title: Re: EM Drive Developments
Post by: birchoff on 10/23/2014 12:52 am
...
I wish we would get a Cavendish-type measurement (as performed by Brito Marini and Galian to nullify the MET-type drive) at John Hopkins as soon as possible.
...

This is not correct. What they tested was an MLT type drive not a MET type drive.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 01:32 am
.....

This is not correct. What they tested was an MLT type drive not a MET type drive.

Thank you for catching that mistake.  I went back and I corrected it.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/23/2014 02:44 am
Am I to understand this 'Ionic Wind' explanation means this device would not produce thrust in a vacuum - or in space?
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 03:00 am
Am I to understand this 'Ionic Wind' explanation means this device would not produce thrust in a vacuum - or in space?

Good question.  There are several explanations that have been proposed for how these (ionic wind) "lifters" work. 
From the theoretical explanation and experiments conducted by Prof.Barrett at MIT the answer is no, they wouldn't work in a vacuum.

Also this 2004 NASA contract report http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040171929.pdf

They conducted several tests in a vacuum and concluded:

"After several days of tests, we found that no device showed signs of rotation at a pressure
less than 300 Torr, with one exception. When Device 2 wired according to Circuit A was placed
in the chamber and immediately pumped down to a pressure of 5.5 × 10–5 Torr, something
interesting happened. The voltage on it was increased to 44 kV, and through the viewing port a
large arc was observed. At that same moment, the device was seen to move about an eighth of a
rotation and stop."

also:

"Robert Talley of Veritay Technology5 performed tests of ACTs in a vacuum in the late
1980’s under Air Force contract. The tests did not let the ACTs spin, but instead suspended it
from a torsion wire. This gave him the sensitivity to be able to measure small forces. His report
is the only written report we have found from the last half-century that describes a measurement
of a force while in a vacuum chamber. Talley ultimately attributed the force that he observed to
the electrostatic interaction between the chamber and the device. Talley wrote, “Direct
experimental results show that under high vacuum conditions… no detectable propulsive force
was electrostatically induced by applying a static potential difference… between test device
electrodes…”
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/23/2014 03:21 am
Quote
Good question.  There are several explanations that have been proposed for how these (ionic wind) "lifters" work. 
From the theoretical explanation and experiments conducted by Prof.Barrett at MIT the answer is no, they wouldn't work in a vacuum.

what I expected.  Still, I wonder if a 'cheat' would work...have the device - or at least the electrodes surrounded by a 'atmosphere' emitted from the spacecraft itself.  Of course, you'd have to continuously replenish this
'atmosphere.'

But at this point, we are almost in normal ion drive territory anyhow.

Be real interesting to see how any of these EM drives do in a vacuum. 
Title: Re: EM Drive Developments
Post by: Star One on 10/23/2014 06:26 am

Am I to understand this 'Ionic Wind' explanation means this device would not produce thrust in a vacuum - or in space?

Still useful then as a general principle if they will operate in an atmosphere, question is to me in relation to space how much of an atmosphere do they need to operate.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/23/2014 06:34 am
Quote
Still useful then as a general principle if they will operate in an atmosphere, question is to me in relation to space how much of an atmosphere do they need to operate.

Hence the 'cheat' - have the area around the electrodes partly enclosed, and inject just enough gas into the area for the device to function.  You'd have to replenish the gas fairly often, though.

But if the 'EM Drive' is a variant of these 'ionic wind lifters' that can function in a vacuum, then things get interesting. 

Vacuum testing needed.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/23/2014 07:58 am
How can it be postulated that Evanescent Waves by themselves can solve the closed-system, momentum-conservation problem?

They can't by themselves using classical physics.  One spaceship may transmit an evanescent field to move external small nanosatellites next to it (would not be an interesting form of propulsion, and the center of mass composed by the nanosatellites and the spacecraft system would not accelerate either).  But it cannot move itself just by using Evanescent waves without any external field. 

A spaceship cannot propel itself by using Evanescent Waves any better than it can propel itself using Electromagnetic Fields.  It is a closed system.

A swimmer can swim in the ocean because the ocean water has its own inertia and resists acceleration.  An astronaut cannot propel itself by waving her arms and legs in space.

To enable propulsion one must have an open system: external dark matter, external fields: like the Earth's magnetic field, an external aether, even consideration of the external quantum vacuum, etc.  But certainly not just Evanescent Fields by themselves that are self generated and only interacting in a closed system.

To avoid this confusion one must rely on conservation principles: conservation of momentum, conservation of energy, and variational principles.

I'm glad to see you are finally starting to acknowledge what I have been trying to drive home all this time about closed systems, and appear to have taken to heart what I introduced previously about hidden momentum.

As I have always said, you can't get thrust from what is happening inside of a closed system, except by artifacts, like leaking heat and magnetic influence. The experimentalist tell me they measured thrust. It is my job to find out why without breaking physics, or making up new physics.

Unfortunately, where I'm going with evanescent fields (which would appear on the outside of a waveguide/cavity/whatever) it is making it appear that EMdrive isn't viable. Normally an evanescent field doesn't have any effect whatsoever, unless it is able to couple to a nearby structure, weakly or strongly. I'm still working on it. Hope I'm wrong.

I am working on the geometry (slope) of the truncated cone and how it could give rise to a rash of leaky evanescent modes. It is not easy. Need help really.
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1273995#msg1273995
Using Aero's info from Shawyer, thanks.

"The small end diameters are set just above the cut-off diameter corresponding to the mode and frequency of the design."

"The small end diameters are set just above the cut-off diameter corresponding to the mode and frequency of the design."
Evanescent modes are modes below the cutoff frequency.

The 6.25 inch small end dimension I educatedly guessed. The 6.25 inch cutoff freq is 1889mhz.
1880mhz is 6.28 inches. 1932-1936mhz is 6.1 inches. Seems like this thing is operating above and below cutoff, where cutoff is measured across the small end of the device. So basically right on the edge of cutoff, modified by the accuracy of their signal generating equipment. I didn't see them using an Anritsu or anything accurate. I have to measure the slope of the device more carefully.
Working this angle...........I haven't completely pulled the trigger on this yet. More work is needed....

If this device is say ~6inch at the small end and ~12 inch at the large end, the bandwidth is between 1968mhz and 984mhz. But it is being operated at a single frequency somewhere in between arbitrarily, but close to cutoff.

I don't have the thickness of the cavity walls, but in evanescent fields, it isn't important, as the rule of thumb for the near field zone is 1/3 of wavelength~2 inches for the Nasa test article.

Near field effects could possibly put a nail in EMdrive's coffin. I hope not, but science isn't a process of trying to prove things work or are right. It is the other way around.

A backgrounder on strongly coupled evanescent fields...it is the conceptual basis for inductive non radiative wireless charging we use for our cell phones and tablets.

Evanescent fields appear on the outside of waveguides and fall off exponentially (quickly). They don't interact with hardly anything unless they can couple to another transmission line or structure which can accept the leaky mode, either strongly or weakly. The structures around the test articles could be that structure. It is worthy of exploration. Near field effects aren't fringe science. They are real and we use them every day.

Marin Soljacic from MIT, has a lot of work published that I'm reading related to this.

Edited for clarity/grammar.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/23/2014 09:39 am
Quote
Still useful then as a general principle if they will operate in an atmosphere, question is to me in relation to space how much of an atmosphere do they need to operate.

Hence the 'cheat' - have the area around the electrodes partly enclosed, and inject just enough gas into the area for the device to function.  You'd have to replenish the gas fairly often, though.

But if the 'EM Drive' is a variant of these 'ionic wind lifters' that can function in a vacuum, then things get interesting. 

Vacuum testing needed.

I can safely rule out ionic wind effects because the device walls aren't charged with thousands of volts DC required for an ionization wind to form. See the Biefeld–Brown effect effect. This was thoroughly debunked, as not antigravity, just ionized air flowing.

But I CAN safely say there are thermal effects: See the attached pic. You can see the instant 70uN impulse at rf on followed by a gradual heat buildup providing a gradual thrust increase, followed by an instant impulse drop at rf off, followed by cooling. For some reason, TE behaved this way. Slow heating and cooling are they only ways I can see a gradual build and decline over 30 seconds.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/23/2014 10:36 am
Quote
So the complete total of all the photons in the cavity are giving their momentum up, and more, to thrust every second. How can that possible make sense. And even don't look at the energy.

Unruh waves can't come close to making a big enough change in mass to cause lost mass to exceed the existing mass. (mi=m(1-L/4T)) For this to work, T would need to be equal to or less than L/4.

There is one way of course but if I say "Tachyons," I'll likely be banned.

Then don't say 'Tachyons.'

I've has idle thoughts about a long shot possible resolution to this problem these past couple of days.

Muletron posted a video a couple days ago giving sort of a capsule history of research into subatomic particles.  The part that intrigued me was where the narrator put forth a chart showing a dozen plus subatomic particles discovered in the search for the Higgs boson.  His attitude - which I'd seen before in print - was one of embarrassed dismissal.  The attitude being these particles are a sort of unprofitable sideline, not worth detailed investigation.    Yet I wonder...might not one or more varieties of these particles hold part of the solution to this drive?  They are elementary 'building block' type critters - maybe certain rules don't fully apply to them?  Maybe they're attracted to photons?

Seems to be three very different hypothesis for EMdrive effect to be real (usable in deep space)

1/ Unknown particles constitute a "bath" and EMdrives are interacting with them. We did a few calculations with dak matter (axions...) as candidate and it could just very barely account to relevant thrust magnitudes given the proven upper bounds of dark something in solar system (as "something", whatever it is, surely has gravitational effects) and taking all but the most optimistic assumptions, in particular a perfect coupling, that is using a coupling constant of 1 when the experiments seems to put the bar below 10^-15. Going faster and faster, at some point one will have to overcome more medium incoming momentum than can get from throwing it backward even faster (i.e. air breathing at Mach 10...) and therefore we should expect a decreasing efficiency at speeds approaching 1/(thrust/power) relative to the medium. That is lower usable speed when higher thrust/power. The superconducting Shawyer thingy of latest presentation (was it really built and tested ??) at 1N/kW is around 1km/s. This means that strong sidereal times correlation should be expected in the experiments results, unless the medium "wind" is synchronised with earth orbit and earth rotation at its surface. Unlikely for a weakly interacting medium. Any case, not only interstellar but also interplanetary transits couldn't count on 1N/kW.
I see one last chance if the medium is composed of particles with widely varying velocities around the average local flow (that is, we have a hot gas of particles) and the device somehow succeeds at interacting only with the ones going the right way (roughly comoving, or coming from behind and pushing like for a sail) . At least two hurdles to overcome then : the amount of "dark something" which we know is bounded (from gravitational studies) and barely making it if all of it were used, and there we are talking of using just a part of it. And the fact that this "coupling with only the velocities that serve my purpose" seriously looks like a Maxwell's demon : need to properly address the thermodynamic of it.

2/ Quantum vacuum would also fit in this category of "bath" but exhibits a very specific behaviour : contrary to any sea of real particles it doesn't define a natural local rest frame (an average group velocity vector in the vicinity) if Lorentz invariance is to hold. So if it is a plasma, it is a plasma that is always harvested at rest speed. This is very convenient when compared to the previous situation. Also, this is breaking apparent energy conservation... Whatever we are harvesting at 0 speed relative to us were not 0 speed relative to others, and hence we are subtracting energy from vacuum. Which is, by definition, supposed to be a zero point... I don't see that is making any sense. Much more serious brains than mine on the subject ( John Baez, Sean Carroll ) have the same view about this quantum vacuum plasma. Authority is not a scientific argument by itself but at some time one has to say when an idea (even to explain a supposedly real effect) is just so deeply flawed as being nonsense. We may also have a Maxwell's demon hiding its hideous face behind the curtain of "quantum vacuum plasma".

3/ We are not using a bath or aether, the EMdrive just comes by on its own in nothingness and emits something that is forever lost (can't be closed, closed solutions can't see their centre of energy depart from an inertial trajectory). So if I consider a device in its own rest frame, it is spending a infinitesimal energy E, with this Energy it "creates" and gives velocity to a "thing" of mass m that is leaving and never to come back again. With Gamma the Lorentz factor 1/sqrt(1-v²/c²), v in the rest frame where the device is not (yet) moving.
E = gamma m c²  Energy spent by device to give thing of mass m a velocity of v
p = gamma m v  Momentum of the thing of mass m and velocity leaving the device forever
We agree that conservation of energy and conservation of momentum are the two most fundamental rules to apply. So for the later, the device gets a reaction kick of p momentum, at the price of spent energy E.
Thrust is momentum kicks per second, Power is spent Energy  per second. Hence :
thrust/power = p/E = v/c²

The consequences are
thrust/power < 1/c => v/c² < 1/c => v<c    classical rocket, reaction on usual mass
thrust/power = 1/c => v/c² = 1/c => v=c    photon rocket, reaction on particles of 0 rest mass
thrust/power > 1/c => v/c² > 1/c => v>c    tachyon rocket, reaction on particles of imaginary rest mass

So in effect : we say tachyons !
That explains all, why claiming thrust/power>1/c for EMdrive automatically seems to contradict energy conservation. We are getting more total kinetic energy at the end of a mission than was put in by the generator, because we are emitting debt, each tachyon carries away at FTL velocity a borrowing never to be paid back.

Except that apparently to prevent problems of causal paradoxes, a system that emits tachyons also receive tachyons, and can't tell the difference between emitting and receiving tachyons (http://en.wikipedia.org/wiki/Tachyon#Reinterpretation_principle). That or otherwise superluminal particles either don't exist or never interact (not even gravitationally). Anyway, would make a pure tachyon emitter an impossibility.

Got to speak to my government about this interesting prospect of sending debt away at FTL speed to be sure never to hear about it again.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/23/2014 12:03 pm
I should add that
thrust/power < 1/c => v/c² < 1/c => v<c    classical rocket, reaction on usual mass
is not in contradiction that obviously a classical chemical rocket or ion thruster has thrust/power_ej>1/c where power_ej is the power used to give ejected mass its velocity. To fairly compare classical action/reaction schemes with "propellantless" schemes, the ejected mass has to count as for its equivalent energy content. Ie a classical rocket sending backward m kg at subrelativistic v m/s is forever losing an energy of 1/2mv² + mc² and this mc² term is huge compared to 1/2mv² (the only energy accounted for in power_ej). This mass would have been better spent by being converted to energy and sent backward as 0 rest mass particles (photon rocket).

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 12:30 pm
I made a ... estimate of the Flight thruster dimensions operating at 385 GHz.

w-small =    7.062943185   cm
w-big =   11.02062266   cm
height =    7.114289902   cm

This is not even wrong.  Clearly, the dimensions are:

w-small =    7.1142899020001   cm
w-big =   11.0629431850002   cm
height =    7.020622660003   cm

couldn't resist.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 12:57 pm
I ... estimate ... the Flight thruster dimensions ...

w-small = 1"
w-big =   2"
height = 3"

...

I am dizzy with all the tests that Shawyer has conducted and with the different names he gives the tested device.  ...

This is circumstantial and corroborating evidence supporting the conjecture regarding the intentional reluctance of the experimentors to freely share their data.

The reluctance is certainly understandable, for at least three reasons, none of which can be discussed except on an informal basis among disinterested professional friends:

1. A surfeit of professional pride in understanding the obscure physics, combined with the typical disregard paid by professionals to amateur website contributors.

B. A pragmatic need to share without sharing, knowing full well the economic benefits of a vastly superior propulsive method.

iii. A stubborn refusal to realize that nothing is being seen.

Vee. Other reasons, such as keeping the rabble occupied with measuring Faztek thingies, so as to keep them off the streets protesting the forty year lack of accomplishment at NASA at doing what was promised back then; a peaceful future realizing mankind's destiny in the universe at large.

As I mentioned at:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1274449#msg1274449

I note that we are spending a lotta time arguing about these dimensions.  The good Doctor asked, rather politely, a hundred or more pages ago, but got only partial dimensional answers.  Since then Paul March decided to go mum. 

Easily answered questions go without answer, which reflects on those who experiment, not on those who try to understand.

I'd like to thank the EagleWorks team for their help and cooperation.  (They should probably set up shop in Awizona; 'twould help their worldview.)

On the plus side, thanks to decent forum moderation, we no longer have to hear from those who disparage everybody's credentials.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 12:59 pm
A much higher frequency might indicate flex in the arm itself.

Prima facie evidence that not all that much is happening.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 01:01 pm
A much higher frequency...

...My impression is that the discrepancy...

An honest attempt at understanding, but still fundamentally a grasping of straws.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 01:10 pm
The dimensions I suggested on A1.4 are inaccurate, because the support is behind the device.  The proportions of the device are correct.

The actual dimensions of the device are roughly presented and are not off by more than a few single digit percentages, since the support is not all that far away from the center of the device.

The only way to test the theory of resonance mentioned earlier, is to analyze these proportions with the reported frequencies, and see if a resonant mode is reached.

This search is beyond my present capabilities, and not at all in my to-do list.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 01:12 pm
Another device of equivalent preagmatic utility.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 01:31 pm
It is incorrect to state that only DC fields can produced ionic winds.  I don't know whether such misunderstanding comes from getting information from Wikipedia.

AC fields can also produce ionic wind in a variety of ways.  For example, the point electrode and ring electrode system is capable of generating electric winds (with velocities of few m/s) for both DC and AC applied voltages.  In the AC regime, ions generated within the corona move in the field and migrate a distance before recombining; the net flow of ions away from the corona creates a time-averaged force that drives the steady flows.  AC coronas can sustain wind velocities of over 1m/s independent of electrode separation in marked contrast to DC coronas.

Another arrangement in which AC fields can produce ionic wind is dielectric barrier discharge actuators.  AC applied across the electrodes through the dielectric produces a variety of electric breakdown phenomena (e.g., corona, streamers, and plasma).  Spark breakdown is prevented by the dielectric barrier.  The dielectric material needs to be in contact with electrodes such that the electrodes contact each surface of the dielectric.

Transient migration of charged species within AC fields also gives rise to steady electric winds.

In contrast to winds driven by DC fields, AC fields (as in the point electrode and ring electrode system ) generate wind velocities comparable with (or better than) the strongest DC winds for any value of the electrode separation.  In the high-frequency  AC regime (>1 KHz), the electric force is localized within a region near the tip of the point electrode. 

From a fundamental perspective, any type of electric wind (DC or AC) derives from the same basic mechanism whereby a steady flux of ions transfers momentum to the surrounding fluid to drive steady gas flows.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 01:36 pm
Another device of equivalent preagmatic utility.
Doesn't the pictured device only work in a partial vacuum (thus the glass enclosure) and neither the discussed NASA Eagleworks, Shawyer or Chinese experiments were conducted in such partial vacuum conditions inside glass enclosures?

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=616719;image)
Title: Re: EM Drive Developments
Post by: birchoff on 10/23/2014 01:43 pm
I ... estimate ... the Flight thruster dimensions ...

w-small = 1"
w-big =   2"
height = 3"

...

I am dizzy with all the tests that Shawyer has conducted and with the different names he gives the tested device.  ...

This is circumstantial and corroborating evidence supporting the conjecture regarding the intentional reluctance of the experimentors to freely share their data.

The reluctance is certainly understandable, for at least three reasons, none of which can be discussed except on an informal basis among disinterested professional friends:

1. A surfeit of professional pride in understanding the obscure physics, combined with the typical disregard paid by professionals to amateur website contributors.

B. A pragmatic need to share without sharing, knowing full well the economic benefits of a vastly superior propulsive method.

iii. A stubborn refusal to realize that nothing is being seen.

Vee. Other reasons, such as keeping the rabble occupied with measuring Faztek thingies, so as to keep them off the streets protesting the forty year lack of accomplishment at NASA at doing what was promised back then; a peaceful future realizing mankind's destiny in the universe at large.

As I mentioned at:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1274449#msg1274449

I note that we are spending a lotta time arguing about these dimensions.  The good Doctor asked, rather politely, a hundred or more pages ago, but got only partial dimensional answers.  Since then Paul March decided to go mum. 

Easily answered questions go without answer, which reflects on those who experiment, not on those who try to understand.

I'd like to thank the EagleWorks team for their help and cooperation.  (They should probably set up shop in Awizona; 'twould help their worldview.)

On the plus side, thanks to decent forum moderation, we no longer have to hear from those who disparage everybody's credentials.

Does this mean we have collectively gotten to the point that there is not enough information available to make any conclusions?
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 01:55 pm

Does this mean we have collectively gotten to the point that there is not enough information available to make any conclusions?
No:
Quote
The reports of my death have been greatly exaggerated.
Collective interested in finding out the reason for EMDrive's measured thrust
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 02:05 pm
I ... estimate ... the Flight thruster dimensions ...

w-small = 1"
w-big =   2"
height = 3"

...

I am dizzy with all the tests that Shawyer has conducted and with the different names he gives the tested device.  ...

Does this mean we have collectively gotten to the point that there is not enough information available to make any conclusions?

Yes, unequivocally.

Tried have you, young Paduan.  Now, looook harder must you, if to find a new force you seek.

I've been following that work since '09, and the reported effects continue to verge on noise, lack repeatability, are not supported by a fuller disclosure, and are largely ignored by paid and tenured faculty.  Each successive experiment claims a subtly different operating principle; still, the trendline for results is flat at best, and not pragmatically applicable at worst.

If you, Frob, Mull, NotSo, Zen, and who all else, believe that there is a line of inquiry which would support a theory of pushing against, for want of a better term, the ether, then maybe it's time for a new thread, laying out the hardware and protocol for a new experiment.

I offer to buy the five of you a Scotch, served by my mixologist, natch, the day after the device is truthfully floated across the conference room table.

Edit:  Uhhhh.... the six of you.  How could I have forgotten the good doctor?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 02:08 pm

Does this mean we have collectively gotten to the point that there is not enough information available to make any conclusions?
No:
Quote
The reports of my death have been greatly exaggerated.
Collective interested in finding out the reason for EMDrive's measured thrust

Disagree.  Time to create theory, not attempt to understand that which is being kept under wraps.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 02:24 pm

Does this mean we have collectively gotten to the point that there is not enough information available to make any conclusions?
No:
Quote
The reports of my death have been greatly exaggerated.
Collective interested in finding out the reason for EMDrive's measured thrust

Disagree.  Time to create theory, not attempt to understand that which is being kept under wraps.
Well, there are still those of us here whose only purpose being in this thread was and still is to objectively understand the reason for EMDrives's measured thrust. 

We are not here with an agenda to show that the results are an experimental artifact nor do we have an agenda to explain it using any particular exotic physics.  Our only object has been and continue to be to understand the EMDrive's measured thrust and we think we have made very considerable progress in this regard.  The level of discourse in this thread, including mathematical analysis, spreadsheets, numbers, AutoCAD drawings with dimensions, statistical analysis, C programs with tens of thousands of formulas explored, quantitative discussion of physics including photon rockets, dark matter, modified inertia, etc., is clearly the best that can be found in the Internet concerning discussion of the EM Drive.

We don't have any intention to go away at this point in time.

Thanks to all who have contributed to this thread by  performing calculations, by critically examining theories, by providing different reports, presentations and information, by providing dimensions for drawings and also thanks to those who have provided humor along the way. 

Quote
In the realm of ideas everything depends on enthusiasm... in the real world all rests on perseverance.
Johann Wolfgang von Goethe

Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 03:11 pm
A much higher frequency might indicate flex in the arm itself.

Prima facie evidence that not all that much is happening.
Could you repeat that?

Concerning NotSoSureOfIt question regarding March perhaps not quoting the lowest mechanical natural torsional frequency of the inverted pendulum, why would that be "Prima facie evidence that not all that much is happening" ?   

Why would arm-bending-motion of 1.5"by1.5" Aluminum beams be evidence of "not all that much happening"?

If there would be bending of the arm, as posited by NotSoSureOfIt, what would excite such arm-bending-motion of 1.5"by1.5" Aluminum beams?

One reaches the opposite conclusion: that if there would be would arm-bending-motion of 1.5"by1.5" Aluminum beams, actually more would be happening than just rotational (torsional) motion of the torsion inverted pendulum.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/23/2014 03:38 pm
Of course the original comment was to address the time delay.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 03:57 pm
A much higher frequency might indicate flex in the arm itself.

Prima facie evidence that not all that much is happening.
Could you repeat that?

Concerning NotSoSureOfIt question regarding March perhaps not quoting the lowest mechanical natural torsional frequency of the inverted pendulum, why would that be "Prima facie evidence that not all that much is happening" ?   

Why would arm-bending-motion of 1.5"by1.5" Aluminum beams be evidence of "not all that much happening"?. ...

If there are micronewtons being "detected", and it is thought that somehow the vibrations associated with these forces are "flexing" the beam, surely the beam is not in danger of breaking.  Not much flexing is happening, because not much force is being detected.

NotSo didn't say anything about March "not quoting" anything.  To have done so would ascribe motive, and that is not the case.  NotSo is saying and only saying that another explanation about the frequency might indicate that the arm itself is flexing.

Again, to me, there does not seem to be much "flexure" at all in the massive beam at hand.  Massive in comparison to the "detected" forces.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/23/2014 04:18 pm
There are microneutons of force moving lbs of mass against an unknown damped spring constant to equilibrate after an unknown distance in an unknown time.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 04:42 pm
Of course the original comment was to address the time delay.
Prima facie evidence that not all that much is happening.

I attach the time response I computed for the nonlinear coupled equations of motion for the torsional inverted pendulum using Mathematica, and the known parameters.  I obtained the nonlinear coupled equations of motion computing the Lagrangian also using Mathematica.

As it is evident from the graph the 2 sec time delay comes straight from the dynamics of the torsional inverted pendulum.  The 2 sec time delay is certainly not a thermal effect, it is fully explained by classical inertia response.  Any mechanical system with an equation of motion of the form m d2xdt2 + c dx/dt + k x = F(t) has a time-dependent response. (Where m, c  and k are matrices of course, and where in this case we include the nonlinear coupling terms on the right hand side)

I have published articles in peer-reviewed journals concerning calculation of much more complicated response than this.  See for example:  http://appliedmechanics.asmedigitalcollection.asme.org/article.aspx?articleid=1407189

A simple calculation of the Fourier dimensionless time based on the known heat capacity, density and thermal conductivity for the materials involved, as well as characteristic dimension, readily shows that this 2 sec time delay cannot be due to thermal effects, as also intuited by Paul March (using other words) early on in this thread.
Title: Re: EM Drive Developments
Post by: zen-in on 10/23/2014 05:11 pm
There are microneutons of force moving lbs of mass against an unknown damped spring constant to equilibrate after an unknown distance in an unknown time.

I attach the time response I computed for the nonlinear coupled equations of motion for the torsional inverted pendulum using Mathematica, and the known parameters.  I obtained the nonlinear coupled equations of motion computing the Lagrangian also using Mathematica.

As it is evident from the graph the 2 sec time delay comes straight from the dynamics of the torsional inverted pendulum.  The 2 sec time delay is certainly not a thermal effect, it is fully explained by classical inertia response.  Any mechanical system of the form m d2xdt2 + c dx/dt + k x = F(t) has a time-dependent response.

I have published articles in peer-reviewed journals as the Journal of Applied Mechanics concerning calculation of much more complicated response than this.  See for example:  http://appliedmechanics.asmedigitalcollection.asme.org/article.aspx?articleid=1407189

A simple calculation of the Fourier dimensionless time based on the known heat capacity, density and thermal conductivity for the materials involved, as well as characteristic dimensions, readily shows that this 2 sec time delay cannot be due to thermal effects, as also remarked by Paul March (using other words) early on in this thread.

No doubt there is an inertial component to the thrust step response.   However its presence doesn't negate a thermal signature in the thrust step response.   The graphs we have seen do not rule that out.   If an exponential step response, due to a thermal effect, was convolved with the step response you derived it would show the exponential shape of Shawyer's and the JSC thrust plots. 

It also doesn't explain why the thrust continues after the RF is turned off.   The plots record thrust, not velocity.  Inertia of the balance system and apparatus can explain continued velocity but not a continued force after the RF is switched off.   The continued force seen in both Shawyer's and the JSC graphs indicate stored energy that is being released after the RF is switched off.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 05:24 pm
...
No doubt there is an inertial component to the thrust step response.   However its presence doesn't negate a thermal signature in the thrust step response.   The graphs we have seen do not rule that out.   If an exponential step response, due to a thermal effect, was convolved with the step response you derived it would show the exponential shape of Shawyer's and the JSC thrust plots. 

It also doesn't explain why the thrust continues after the RF is turned off.   The plots record thrust, not velocity.  Inertia of the balance system and apparatus can explain continued velocity but not a continued force after the RF is switched off.   The continued force seen in both Shawyer's and the JSC graphs indicate stored energy that is being released after the RF is switched off.
As we have already established earlier in this thread in discussions with Paul March, there is a (separate from the 2 sec delay)  known issue (already discussed in the NASA Eagleworks report) of longer term drift of the baseline that Paul March attributed to interaction between the magnetic damper and the power cable as well as thermal effects from the unit they have at the back. Observe that this longer term drift also has a damping/inertial component.

The much longer  "continued force seen" in Shawyer's demonstrator is much larger and time-delayed than the one at NASA Eagleworks.

All these time delays cannot be juxtaposed together into one big messy ball to justify throwing the baby with the bathwater and to conclude this as "Prima facie evidence that not all that much is happening."  Such a conclusion is negated by the evidence. 

On the contrary: the evidence shows that something is happening at the NASA Eagleworks tests, in the 2 sec time delay pulse response that is not possible due to thermal effects.  The initial impulsive response is what needs explanation.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/23/2014 05:34 pm
Not to forget the energy stored in the spring. (the plots record displacement)
Title: Re: EM Drive Developments
Post by: aero on 10/23/2014 05:41 pm
I am concerned about the ionic wind explanation. I have applied F = mdot*Ve for the thrust and calculated some candidate values for mdot and Ve for the known thrusters' test cases.

thrust       air mass   air volume   velocity   energy
kg-m/s, N        kg       liters        m/s          .5 mv^2
0.0000501   0.001       0.82       0.05          1.26E-06
0.0000554   0.001       0.82       0.06          1.53E-06
0.0000912   0.001       0.82       0.09          4.16E-06
       0.016   0.100      81.63       0.16          1.28E-03
       0.17    0.500     408.16       0.34          2.89E-02
       0.214   0.500     408.16       0.43          4.58E-02
       0.214   0.500   408.16       0.43          4.58E-02
       0.315   0.500   408.16       0.63          9.92E-02

Of course these are just numbers from my hip pocket but its quite evident that the energy lost to ionic wind would not be detected.

For the Brady cases (first 3) the moving air volume and velocity would be overlooked if they were not watching for it.

Shawyer tested his experimental device within an enclosure to avoid artifacts from external air currents. Ionic wind would have been internal to his enclosure.

Shawyer tested his demonstrator on a cooled test stand. That would probably mask any ionic wind.

I don't know anything about the test setup for the flight model or about the Chinese test setup, as regards to detecting ionic wind.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 06:00 pm
 
All these time delays cannot be juxtaposed together into one big messy ball to ... conclude this as "Prima facie evidence that nothing is happening."

Nobody said that.  I said only that there was prima facie evidence that not all that much is happening.

I didn't say anything about "time delays" either, nor did I ascribe personal motive to NotSo's suggestion regarding time delays.

Please do not read beyond what I have written. 

If there are barely detected oscillating micronewtons of force acting on the experimental apparatus, no doubt there is some oscillating flexural bending in the beam, a number that is probably of the same magnitude as the number of angels who can dance on a pin.

Their experiment does not fail solely because of this issue.

I quite understand that you seek to understand the reported results.  Still, there is not much happening.

Quote from: Rodal
...throwing the baby with the bathwater...

Plus, I don't know nuthin' 'bout birthin' no babies (http://www.youtube.com/watch?v=IIsKGBxn_-g), Miz Scarlet.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 06:14 pm
...only that there was prima facie evidence that not all that much is happening....
Went back and fix'd that. Much more (orders of magnitude more) is happening with Shawyer's demo experiment and the Chinese experiments but unfortunately they are not as well documented as NASA's experiments hence the discussion centers on NASA's.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 06:17 pm
There are microneutons of force moving lbs of mass against an unknown damped spring constant to equilibrate after an unknown distance in an unknown time.

Which implies what, that the illustrated scenario here is just around the corner?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/23/2014 06:21 pm
Time to create theory, not attempt to understand that which is being kept under wraps.

Well, there are still those of us here whose only purpose being in this thread was and still is to objectively understand the reason for EMDrives's measured thrust.

Sorry, sorta, that I expressed my frustration at the death of information from those who would know.

Edit:  Dearth.  Death.  Whatever.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 06:22 pm
....

For the Brady cases (first 3) the moving air volume and velocity would be overlooked if they were not watching for it.

Shawyer tested his experimental device within an enclosure to avoid artifacts from external air currents. Ionic wind would have been internal to his enclosure.

Shawyer tested his demonstrator on a cooled test stand. That would probably mask any ionic wind.

I don't know anything about the test setup for the flight model or about the Chinese test setup, as regards to detecting ionic wind.
Thanks for calculating that.  I continue to be impressed with the useful amount of information you get from the reports.  I had not noticed "Shawyer's cooled test stand"

I will be posting the force/PowerInput from an ionic wind calculation: it comes pretty close to the measured values.
Title: Re: EM Drive Developments
Post by: aero on 10/23/2014 06:34 pm
....

For the Brady cases (first 3) the moving air volume and velocity would be overlooked if they were not watching for it.

Shawyer tested his experimental device within an enclosure to avoid artifacts from external air currents. Ionic wind would have been internal to his enclosure.

Shawyer tested his demonstrator on a cooled test stand. That would probably mask any ionic wind.

I don't know anything about the test setup for the flight model or about the Chinese test setup, as regards to detecting ionic wind.
Thanks for calculating that.  I continue to be impressed with the useful amount of information you get from the reports.  I had not noticed "Shawyer's cooled test stand and his enclosure"

I will be posting the force/PowerInput from an ionic wind calculation: it comes pretty close to the measured values.

Wait a minute - Of course it comes close. I picked an mdot number rather arbitrarily, but then used the measured force value to calculate Ve. They should match exactly. There is no deep analysis here, just choosing some numbers that satisfy the measured force. This to show order of magnitude of the air mass and velocity of the ionic wind that would create the measured force, nothing more.
Title: Re: EM Drive Developments
Post by: zen-in on 10/23/2014 06:49 pm
Not to forget the energy stored in the spring. (the plots record displacement)
The two plots I attached are marked with units of thrust; micronewtons on graph from the Bray, White, et al paper and gram in Shawyer's 2008 paper.   This thrust is derived from the torsion spring angular displacement.   For the thrust to continue after the RF has been switched off, which is the case in both plots, there must be stored energy.   The torsion spring is part of the measuring system and works in opposition to any thrust generated by the em drive so it is not the source of the stored energy.   Thermal energy, if it was the source of the measured thrust, would continue to radiate from the cone section after the RF was switched off.  The heated air would create a thrust in the same direction as is claimed for RF effects inside the device.
quoting Aero:

Shawyer tested his demonstrator on a cooled test stand. That would probably mask any ionic wind.

end quote
So with Shawyer's much higher RF power level (dissipating more power into the device's copper walls) and with the test stand and surrounding air cooled, the thermally generated thrust would be much greater.

Until they are able to show there is thrust in a vacuum chamber I will be convinced the force measured is a thermal  anomaly.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 06:52 pm
... This to show order of magnitude of the air mass and velocity of the ionic wind that would create the measured force, nothing more.
I am reviewing papers on ionic wind (electrohydrodynamics) that place constraints on the wind generated under AC fields.  We also know the magnitude of the Electric Field, the frequency, the TE modes, etc.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 06:58 pm
I recall that Paul March wrote that the EMDrives tested at NASA Eagleworks had a temperature that never rose more than 1 deg (F ? or C?) above room temperature.

Anybody recall that statement?  Is the temperature measurement in the NASA Eagleworks report? Using search I cannot find it in the text.  Is it in the pictures?

I also recall AcesHigh reporting on information elsewhere reporting March's statement he made on this thread regarding temperature.  Was that at nextbigfuture? Does anybody still have a link for that?
Title: Re: EM Drive Developments
Post by: aero on 10/23/2014 07:18 pm
I recall that Paul March wrote that the EMDrives tested at NASA Eagleworks had a temperature that never rose more than 1 deg (F ? or C?) above room temperature.

Anybody recall that statement?  Is the temperature measurement in the NASA Eagleworks report? Using search I cannot find it in the text.  Is it in the pictures?

I also recall AcesHigh reporting on information elsewhere reporting March's statement he made on this thread regarding temperature.  Was that at nextbigfuture? Does anybody still have a link for that?

Quoting a post by Paul March on Talk-Polywell, (Sept 9, 2014 ?)

Quote
BTW, the copper frustum's temperature never rose more than 1.0 degree F. when using the above average power levels and test articles.

Best,


_________________
Paul March
Friendswood, TX

Here is the link http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=2949&hilit=paul&start=210#p115832 (http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=2949&hilit=paul&start=210#p115832)
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 07:47 pm
Quote
BTW, the copper frustum's temperature never rose more than 1.0 degree F. when using the above average power levels and test articles.
Best,
_________________
Paul March
Friendswood, TX

No way that the measured forces can be due to thermal expansion of the copper frustum or due to thermal drafts produced by the copper frustum itself if its temperature never rose more than 1.0 degree F.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 07:55 pm
Also Paul March wrote:

Quote
We found that this slope change after the test article and RF amplifer were turned on for 10-to-20 seconds was apprently due to IR radiation from the amplifier's heatsink that is mounted on the back side of the torque penlulum on an 8" square platform was affecting the top C-flex bearing more than the lower one.  We tried aluminum shielding the top bearing assembly from the heatsink IR source and managed to reverse the metioned thermal slope in the thrust plots, but after shielding the bottom one we could reduce it but still coundn't completely get rid of this thremal drift artifact.  Currently we are just living with it.

and from the report:

Quote
The null force testing indicated that there was an average null force of 9.6 micronewtons present in the as tested configuration. The presence of this null force was a result of the DC power current of 5.6 amps running in the power cable to the RF amplifier from the liquid metal contacts. This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system.

Title: Re: EM Drive Developments
Post by: aero on 10/23/2014 07:56 pm
Don't want to forget that thrust has been measured in the same axial direction relative to the thruster whether the thruster was pointed up, down, left or right. This speaks strongly against outside thermal drafts.

It does not speak to thermal expansion of course.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/23/2014 08:02 pm
Just noticing in "White_thrust.jpg", that the "Pulse 1" at the left hand side of the picture shows an underdamped response of the 300V Calibration pulse.  The vibration period would seem to be of the order of 4 to 5 sec.  Really too bad they did not put the displacement scale there as well as the force.

Can you fit that w/ Mathamatica ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 08:15 pm
I presume notsosureofit is referring to this picture:

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=616615;image)

NotSoSureOfIt:

That's the kind of excellent, scholarly observation that makes it possible to extract information even where the researchers have not explicitly provided.

I had been asking for the magnetic damping constant from Paul March, but he went mute in this forum.

You are 100% right.  I had not noticed that picture.  It seems that it makes it possible to figure out the magnetic damping constant, as it gives the response and I can scale it by the 60.1 microNewton level.

It certainly looks below critical damping.

Great observation!

Thanks!

Thanks also to zen-in that provided the picture that motivated the discussion that motivated this insight.  Great discussion.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 08:29 pm
I also notice that this picture refers to:

Quote
Prior to the TM211 evaluations, COMSOL® analysis indicated that the TE012 was an effective thrust generation mode for the tapered cavity thruster being evaluated, so this mode was explored early in the evaluation process. Figure 22 shows a test run at the TE012 mode with an operating frequency of 1880.4 MHz. The measured quality factor was ~22,000, with a COMSOL prediction of 21,817. The measured power applied to the test article was measured to be 2.6 watts, and the (net) measured thrust was 55.4 micronewtons. With an input power of 2.6 watts, correcting for the quality factor, the predicted thrust is 50 micronewtons. However, since the TE012 mode had numerous other RF modes in very close proximity, it was impractical to repeatedly operate the system in this mode, so the decision was made to evaluate the TM211 modes instead.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 09:27 pm
The previous plot was with a magnetic damping of 6 N s/m = 6 kg /s
(the value of a magnetic dampening system that was investigated for a LIGO pendulum).

Here is a plot of the response using a magnetic damping constant of 1.75 N s/m = 1.75 kg /s instead.

The horizontal scale is in seconds.

As one can see, this is pretty close to the [300V Pulse 1] calibration time response at NASA Eagleworks.  This is very close taking into account that industrial magnetic dampers can exceed 210 000 N s/m.  It is pretty clear that the magnetic damping used for the NASA Eagleworks tests was around 1.75 N s/m.

It was an excellent idea from NotSoSureOfIt to think of this, as this is a much better way to obtain the magnetic damping constant than any value provided by the researchers, as they themselves would have to use a similar procedure (model the response and then obtain the magnetic damping from it) because the actual magnetic damping depends on the distance of the magnets from the metal being damped -see the last picture attached below as to how close are the magnets and how unsymmetrically they did this (two magnets to one side and one to other, and it is closer to one side than the other).

[I haven't scaled the response yet, just the magnetic damper constant.  Then I will investigate the response for different inputs.]

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=616615;image)
Title: Re: EM Drive Developments
Post by: zen-in on 10/23/2014 09:43 pm
Don't want to forget that thrust has been measured in the same axial direction relative to the thruster whether the thruster was pointed up, down, left or right. This speaks strongly against outside thermal drafts.

It does not speak to thermal expansion of course.

My theory on thermally generated thrust claims the cone section transmits heat energy to the surrounding air by conduction.   The two ends do not have exposed Copper so the heat flow from each end would be much less.   FR4 (high density fiberglass as used in PCBs) is a better insulator than Copper.   The fact that March saw < 1 degree change in temperature would be expected because of the good heat transfer from the Copper cone section to the surrounding air.   There is no mention of the surrounding air temperature so I am assuming this < 1 degree change refers to just the Copper section of the device.   

Earlier I posted a picture of a Crooke's radiometer.   The paddle wheels of this device have high and low emmissivity coatings on opposite sides.   The high emmissivity side radiates heat at a faster rate, imparting more momentum to the few air molecules on one side of the paddle than on the other.   The tiny amount of thrust this gives to the paddle, and the very low bearing and air friction are enough to make it spin when light hits it.

The cone section of the JSC device transfers heat to the surrounding air.   After all RF power is being dissipated inside it, being turned into thermal energy, so it has to go somewhere.   This dissipated heat adds momentum to the surrounding air molecules, at right angles to the cone's surface.   When all these momentum vectors are resolved in a cylindrical coordinate system with the Z axis going through the two end caps there are components that are normal to the Z axis and components that are collinear with it.    These collinear components are all additive, resulting in a thrust that is in the same direction as the thrust that is said to be caused by an internal em effect.

Only by experimentation can this alternative theory be eliminated.   For example if the large endcap was replaced with a solid Copper one would that reduce the measured thrust?   What if the cone section was covered with an insulating layer; isolating it from the surrounding air?   Would that reduce the measured thrust or would it not change because of it?

One counter experiment that was done by the JSC team was to use a dummy load.  In that case no thrust was measured.   However the power was not dissipated inside the device.   What if the same amount of power was dissipated inside the device using a DC power source; ie: a heater pad?   That would be a better baseline test because it would test for thermal effects.

Shawyer's device has some differences form the JSC device.   Some pictures show the device with endcaps that appear to be solid Copper.   This would result in a completely balanced thermally generated force.   However as the attached picture shows (from the 2008 paper) a non metallic disk and Aluminum end plate are attached to the wide end before the whole assembly is fastened to the experimental test stand.  So the same thermally generated thrust could be produced by Shawyer's device as well.    Without more photos it is hard to tell.
Title: Re: EM Drive Developments
Post by: aero on 10/23/2014 09:52 pm
Ok. That's well thought out. Now can you explain the lack of thrust from the Brady device without dielectric? Remove the dielectric and there is no thrust. What happened to the heat dissipation?

The other problem that continues to arise is the total momentum .vs. the power dissipated
Title: Re: EM Drive Developments
Post by: zen-in on 10/23/2014 10:08 pm
Ok. That's well thought out. Now can you explain the lack of thrust from the Brady device without dielectric? Remove the dielectric and there is no thrust. What happened to the heat dissipation?

The other problem that continues to arise is the total momentum .vs. the power dissipated

It could be that without the dielectric there is less power being dissipated in the cone section.  Maybe the RF field inside the device results in all the power being dissipated on the end caps.   There are no network analyzer plots for the dielectric-less configuration.   It could be that without the dielectric the reflection coefficient is much higher; ie: most of the applied RF power is being reflected at the feedpoint and is being dissipated in the RF amplifier or circulator external to the em-drive device.  So with no power entering the device there is no thermal effect.
Title: Re: EM Drive Developments
Post by: Rodal on 10/23/2014 11:09 pm
Don't want to forget that thrust has been measured in the same axial direction relative to the thruster whether the thruster was pointed up, down, left or right. This speaks strongly against outside thermal drafts.

It does not speak to thermal expansion of course.

My theory on thermally generated thrust claims the cone section transmits heat energy to the surrounding air by conduction.   The two ends do not have exposed Copper so the heat flow from each end would be much less.   FR4 (high density fiberglass as used in PCBs) is a better insulator than Copper.   The fact that March saw < 1 degree change in temperature would be expected because of the good heat transfer from the Copper cone section to the surrounding air.   There is no mention of the surrounding air temperature so I am assuming this < 1 degree change refers to just the Copper section of the device.   

...
You must have meant to write "transmits heat energy to the surrounding air by conduction convection" because heat transfer by convection in fluids like air occurs much faster than by conduction.  Air has very low thermal conductivity and very low thermal diffusivity, so heat does not get transferred in air by conduction, but by convection.

Heat transfer by convection:

q/A = h  dT

q/A = heat transfer per unit time per unit area

h = heat transfer coefficient

dT =  temperature difference between the surface and the bulk fluid  = Ts - Tf = 1 deg F = 0.56 deg C

Natural convection heat transfer coefficient = 2 to 20 Watt/((m^2)degC))

q/A = 0.56 deg C * 2  Watt/((m^2)degC)) = 1 Watt per square meter

q/A = 0.56 deg C * 20  Watt/((m^2)degC)) = 10 Watts per square meter

l = Sqrt [h^2 + (R - r)^2] = Sqrt [ 0.332^2 + (0.199 -  0.122)^2] = 0.341

Total surface area of truncated cone =  Pi × (  r × (r+l) +   R × (R+l)) =  Pi × ( 0.122× (0.122+ 0.341 ) +   0.199 × (0.199+ 0.341)) = 0.515 m^2

Input Power was from 2.6 Watts to less than 16.9 Watts, so if 100% of the power would have gone into heat:

2.6/0.515 = 5 Watts per square meter

16.9/0.515 = 33 Watts per square meter

The lateral surface area is Pi×l×(R+r) = Pi×0.341×(0.199+0.122) =0.344 m^2

So that only increases the flux by 0.515/0.344 = 1.50, or 50% even if you consider both ends to be completely thermally insulated and that 100% of the heat escapes through the lateral surfaces (which would not be quite the case).  It increases the flux so that it ranges from 7.5 W/m^2 to 49 W/m^2.

So, the delta T given by Paul March (1 deg F =0.56 deg C) makes sense, if a fraction of the input power went into heat that got transferred to the air.

The speed of an air convection current due to only 1 deg F temperature difference is so small, that any air convection naturally occurring within the chamber for other reasons could easily overwhelm it. (The vacuum chamber itself may have had a larger delta T within it for other reasons unrelated to the EM Drive).

Further bad news for explaining the measured forces as due to natural convection circulation is that this can only work with the warm part (the EMDrive) on the bottom of a natural convection circulation system such that the bottom part (the EM Drive)  is warm and the top part of the chamber is cool and therefore the convection would be from the warmer EM Drive towards the  cooler top of the chamber.  (Natural convection taking place because of the extremely small amount difference in temperature: less than 1 deg F, producing extremely small differences in density of the air).

But at NASA Eagleworks the measured forces were in the horizontal direction.  Furthermore, the direction of the force was always oriented towards the large diameter base, even when they flipped the EM Drive to point 180 degrees in the opposite direction.  Furthermore, in the up and down test performed by Shawyer, the direction of the force should not have flipped (as reported by Shawyer) when Shawyer flipped the test article upside down, as natural convection always works such that the warmer part is on the bottom, and the air circulates from the warmer bottom part to the cooler top part of the chamber.

Further bad news for explaining the NASA Eagleworks response as natural convection from the warmer EM Drive is that the NASA Eagleworks test show a pulse response rapidly rising in 2 seconds which coincides with the inertial response of the inverted torsional pendulum, and is way too short a time compared with the Fourier dimensionless time based on the thermal diffusivity of the materials involved and the characteristic length.  So the initial time-response cannot be explained in terms of thermal natural convection.  The speed of heat transfer is restricted by the thermal diffusivity of the material.





Title: Re: EM Drive Developments
Post by: zen-in on 10/24/2014 12:10 am
Don't want to forget that thrust has been measured in the same axial direction relative to the thruster whether the thruster was pointed up, down, left or right. This speaks strongly against outside thermal drafts.

It does not speak to thermal expansion of course.

My theory on thermally generated thrust claims the cone section transmits heat energy to the surrounding air by conduction.   The two ends do not have exposed Copper so the heat flow from each end would be much less.   FR4 (high density fiberglass as used in PCBs) is a better insulator than Copper.   The fact that March saw < 1 degree change in temperature would be expected because of the good heat transfer from the Copper cone section to the surrounding air.   There is no mention of the surrounding air temperature so I am assuming this < 1 degree change refers to just the Copper section of the device.   

...
You must have meant "transmits heat energy to the surrounding air by conduction convection" because heat transfer by convection in fluids like air occurs much faster than by conduction.  Air has very low thermal conductivity and very low thermal diffusivity, so heat does not get transferred in air by conduction, but by convection.
But at NASA Eagleworks the measured forces were in the horizontal direction.  Furthermore, the direction of the force was always oriented towards the large diameter base, even when they flipped the EM Drive to point 180 degrees in the opposite direction.  Furthermore, in the up and down test performed by Shawyer, the direction of the force should not have flipped (as reported by Shawyer) when Shawyer flipped the test article upside down, as natural convection always works such that the warmer part is on the bottom, and the air circulates from the warmer bottom part to the cooler top part of the chamber.

Further bad news for explaining the NASA Eagleworks response as natural convection from the warmer EM Drive is that the NASA Eagleworks test show a pulse response rapidly rising in 2 seconds which coincides with the inertial response of the inverted torsional pendulum, and is way too short a time compared with the Fourier dimensionless time based on the thermal diffusivity of the materials involved and the characteristic length.  So the initial time-response cannot be explained in terms of thermal natural convection.  The speed of heat transfer is restricted by the thermal diffusivity of the material.

I used the Crooke's radiometer as an example.  The rotation of the paddles is not from convection.   The higher emmissivity of the dark side of the paddles imparts more momentum to the air molecules that bump against it because that side of the paddle is hotter.   The dark side of the paddle receives an equal and opposite momentum.   Convection does not transfer momentum with whatever heated the air, unless you are talking about a hot air balloon or bouyancy effects in a closed system.   The air has left and no longer affects whatever has heated it.   The Crooke's radiometer demonstrates how very small power levels can have visible effects and like the em-drive experiments has a low friction bearing.

I just looked at the video of Shawyer's device and it does rotate in the opposite direction from what my theory describes.   However that might just be due to more heat being dissipated from the large end.   In the Eagleworks paper I have not being able to find where the direction of the force is stated.     I'll have to assume it is the same as Shawyer's experiment.     Only by performing other null tests can this possible explanation be eliminated.  eg: run it in a vacuum chamber or apply a heater strip to inner surfaces of the device.
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 12:16 am
.....
I used the Crooke's radiometer as an example.  The rotation of the paddles is not from convection.


Considering Crookes radiometer, eliminates both conduction and convection. 

Crooke's radiometer is contained in a partial vacuum.

None of the tested devices (NASA Eagleworks, Shawyer of Chinese) to my knowledge were tested in a partial vacuum.  To my knowledge Crooke's radiometer does not move under ambient pressure conditions. 
Title: Re: EM Drive Developments
Post by: zen-in on 10/24/2014 12:34 am

Considering Crookes radiometer, eliminates both conduction and convection. 

Crooke's radiometer is contained in a partial vacuum.

None of the tested devices (NASA Eagleworks, Shawyer of Chinese) to my knowledge were tested in a partial vacuum.  To my knowledge Crooke's radiometer does not move under ambient pressure conditions.

I think the reason why a Crooke's radiometer requires a partial vacuum is to minimize air friction.   It also doesn't work in a hard vacuum.

From Wikipedia:
When a radiant energy source is directed at a Crookes radiometer, the radiometer becomes a heat engine. The operation of a heat engine is based on a difference in temperature that is converted to a mechanical output. In this case, the black side of the vane becomes hotter than the other side, as radiant energy from a light source warms the black side by black-body absorption faster than the silver or white side. The internal air molecules are "heated up" (i.e. experience an increase in their speed) when they touch the black side of the vane.
end quote

While this is one theory of how a Crooke's radiometer works it actually rotates in the reverse direction from what this theory would require.   The white side of the paddle trails.   This is described further in the Wikipedia page.   So direct heating of air molecules from a warm surface can have some unexpected results.

from Wikipedia:
Reynolds found that if a porous plate is kept hotter on one side than the other, the interactions between gas molecules and the plates are such that gas will flow through from the cooler to the hotter side. The vanes of a typical Crookes radiometer are not porous, but the space past their edges behaves like the pores in Reynolds's plate. On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. The pressure difference causes the vane to move, cold (white) side forward due to the tangential force of the movement of the rarefied gas moving from the colder edge to the hotter edge.
end quote
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 12:46 am
...
Reynolds found that if a porous plate is kept hotter on one side than the other, the interactions between gas molecules and the plates are such that gas will flow through from the cooler to the hotter side. The vanes of a typical Crookes radiometer are not porous, but the space past their edges behaves like the pores in Reynolds's plate. On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. The pressure difference causes the vane to move, cold (white) side forward due to the tangential force of the movement of the rarefied gas moving from the colder edge to the hotter edge.
end quote

This is an interesting effect of another nature. 

<< The vanes of a typical Crookes radiometer are not porous, but the space past their edges behaves like the pores in Reynolds's plate. On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. >>

How would this work for the EM Drive? 

Would we have to posit that the "porous" part is the gap between the flat bases and the surface of the cone?

It is a fact that all the EM Drives that were tested had removable flat bases that were simply torqued into place, they were not welded or bonded without porosity, so certainly one has to admit that there is a gap through which  gas molecules can move (at the circumferential gap of the bases instead of the edges of the blade of the radiometer).
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/24/2014 01:14 am
Thanks also to zen-in that provided the picture that motivated the discussion that motivated this insight.

And thanks also to Jack (http://www3.amherst.edu/~rjyanco94/literature/mothergoose/rhymes/thisisthehousethatjackbuilt.html), who built the house that... never mind.
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 01:17 am
Thanks also to zen-in that provided the picture that motivated the discussion that motivated this insight.

And thanks also to Jack (http://www3.amherst.edu/~rjyanco94/literature/mothergoose/rhymes/thisisthehousethatjackbuilt.html), who built the house that... never mind.
and thanks also to John  :)
Title: Re: EM Drive Developments
Post by: zen-in on 10/24/2014 01:51 am
...
Reynolds found that if a porous plate is kept hotter on one side than the other, the interactions between gas molecules and the plates are such that gas will flow through from the cooler to the hotter side. The vanes of a typical Crookes radiometer are not porous, but the space past their edges behaves like the pores in Reynolds's plate. On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. The pressure difference causes the vane to move, cold (white) side forward due to the tangential force of the movement of the rarefied gas moving from the colder edge to the hotter edge.
end quote

This is an interesting effect of another nature. 

<< The vanes of a typical Crookes radiometer are not porous, but the space past their edges behaves like the pores in Reynolds's plate. On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. >>

How would this work for the EM Drive? 

Would we have to posit that the "porous" part is the gap between the flat bases and the surface of the cone?

It is a fact that all the EM Drives that were tested had removable flat bases that were simply torqued into place, they were not welded or bonded without porosity, so certainly one has to admit that there is a gap through which  gas molecules can move (at the circumferential gap of the bases instead of the edges of the blade of the radiometer).

Crooke's radiometer theory from Wikipedia:
On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. The pressure difference causes the vane to move, cold (white) side forward due to the tangential force of the movement of the rarefied gas moving from the colder edge to the hotter edge.

Applying this to the em-drive the large end would be the cold side and the cone section the hot side.   Air moves from the cold side to the hot side and generates a tangential force.   This force is in the same direction as the theorized em force.  (opposite to what I was proposing earlier).   I don't think this requires a partial pressure; just a very low friction bearing or torsion pendulum.

Shawyer's up/down thrust plot is not symmetrical.   The up plot has a faster rise time.  I could speculate that this difference is due to convection.   But I don't know enough about how these plots were done.
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 02:04 am
...
Crooke's radiometer theory from Wikipedia:
On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. The pressure difference causes the vane to move, cold (white) side forward due to the tangential force of the movement of the rarefied gas moving from the colder edge to the hotter edge.

Applying this to the em-drive the large end would be the cold side and the cone section the hot side.   Air moves from the cold side to the hot side and generates a tangential force.   This force is in the same direction as the theorized em force.  (opposite to what I was proposing earlier).   I don't think this requires a partial pressure; just a very low friction bearing or torsion pendulum.

Shawyer's up/down thrust plot is not symmetrical.   The up plot has a faster rise time.  I could speculate that this difference is due to convection.   But I don't know enough about how these plots were done.

Mmmm.  The person that wrote this on Wikipedia literally copied what Prof. John Baez had already explained in his blog several years ago:

http://math.ucr.edu/home/baez/physics/General/LightMill/light-mill.html

Since Prof. Baez has been one of the very outspoken critics of Dr. White's Quantum Vacuum Plasma explanation and the NASA Eagleworks tests, I find it interesting, that to my knowledge Prof. Baez has not advanced the Crook radiometer theory as an explanation for the NASA Eagleworks experiments.  Maybe this is a question that can be posed to Prof. Baez himself since the explanation quoted from Wikipedia has been taken from Baez himself.

Title: Re: EM Drive Developments
Post by: zen-in on 10/24/2014 02:12 am
...
Reynolds found that if a porous plate is kept hotter on one side than the other, the interactions between gas molecules and the plates are such that gas will flow through from the cooler to the hotter side. The vanes of a typical Crookes radiometer are not porous, but the space past their edges behaves like the pores in Reynolds's plate. On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. The pressure difference causes the vane to move, cold (white) side forward due to the tangential force of the movement of the rarefied gas moving from the colder edge to the hotter edge.
end quote

This is an interesting effect of another nature. 

<< The vanes of a typical Crookes radiometer are not porous, but the space past their edges behaves like the pores in Reynolds's plate. On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. >>

How would this work for the EM Drive? 

Would we have to posit that the "porous" part is the gap between the flat bases and the surface of the cone?

It is a fact that all the EM Drives that were tested had removable flat bases that were simply torqued into place, they were not welded or bonded without porosity, so certainly one has to admit that there is a gap through which  gas molecules can move (at the circumferential gap of the bases instead of the edges of the blade of the radiometer).

Crooke's radiometer theory from Wikipedia:
On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. The pressure difference causes the vane to move, cold (white) side forward due to the tangential force of the movement of the rarefied gas moving from the colder edge to the hotter edge.

Applying this to the em-drive the large end would be the cold side and the cone section the hot side.   Air moves from the cold side to the hot side and generates a tangential force.   This force is in the same direction as the theorized em force.  (opposite to what I was proposing earlier).   I don't think this requires a partial pressure; just a very low friction bearing or torsion pendulum.

Shawyer's up/down thrust plot is not symmetrical.   The up plot has a faster rise time.  I could speculate that this difference is due to convection.   But I don't know enough about how these plots were done.

Mmmm.  The person that wrote this on Wikipedia literally copied what Prof. John Baez had already explained in his blog several years ago:

http://math.ucr.edu/home/baez/physics/General/LightMill/light-mill.html

Since Prof. Baez has been one of the very outspoken critics of Dr. White's Quantum Vacuum Plasma explanation and the NASA Eagleworks tests, I find it interesting, that to my knowledge Prof. Baez has not advanced the Crook radiometer theory as an explanation for the NASA Eagleworks experiments.  Maybe this is a question that can be posed to Prof. Baez himself since the explanation quoted from Wikipedia has been taken from Baez himself.

Prof. Baez's explanation is a lot easier to follow.  The Wikipedia authors left a lot out.   It turns out the paddles of a Crooke's radiometer do turn as if a force was pushing against the dark side of each paddle.   This analogy does not match the results of the em-drive experiment.
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 02:17 am
[...

Prof. Baez's explanation is a lot easier to follow.  The Wikipedia authors left a lot out.   It turns out the paddles of a Crooke's radiometer do turn as if a force was pushing against the dark side of each paddle.   This analogy does not match the results of the em-drive experiment.
Thanks for pointing out that observation.

https://www.youtube.com/watch?v=0FbJRPG64So
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 05:18 am
I'm not happy with my understanding of Shawyer's terminology. In particular he uses the terms Lo, Lg1 and Lg2 in his derivations. (I have taken the liberty to use "L" in place of "lamda" here.) One of his derivation papers can be found here.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCQQFjAB&url=http%3A%2F%2Fwww.emdrive.com%2FCEAS2009paper.doc&ei=nsFJVIH-A6_1iQKLnoHwAw&usg=AFQjCNGgzJQ1yl_K5kVzCOBAKkv3E3U-4w&sig2=1sgg_WEjJw9rhHJ-Wla6UA (http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCQQFjAB&url=http%3A%2F%2Fwww.emdrive.com%2FCEAS2009paper.doc&ei=nsFJVIH-A6_1iQKLnoHwAw&usg=AFQjCNGgzJQ1yl_K5kVzCOBAKkv3E3U-4w&sig2=1sgg_WEjJw9rhHJ-Wla6UA)

I'm reasonably confident that Lo is the RF drive wavelength. I thought that Lg1 and Lg2 were the big and small end diameters of the cavity. Shawyer gives an equation for the "Design Factor" of his thruster which is a function of those values only and I read that for his Demonstrator Thruster, the design factor = 0.844. Since I thought I knew the values for Lo and Lg1 I decided to search for the valu Lg2. I have attached a plot of my calculation of the design factor less 0.844, as a function of Lg2, with Lo and Lg1 fixed. The plot should cross zero where Lg2 gives the design factor = 0.844. (Recall that the diameter of the demonstrator thruster is 280 mm.)

But look at the shape of the curve. Its going to cross zero in about the same place for any value of the design factor. I calculated the zero value region with a much finer grid and the curve doesn't really cross zero at all. It appears to have a vertical asymptote at the zero crossing so I don't know what that means.

I wonder, could someone help me out here? Here is my Excel if that helps.

c=   2.99792E+08   f =    2.45E+09   Hz
   for Shawyer b", Lamda = Lo =    1.22364E-01   m   
   Lg1 =    0.280   m   
Df = 0.844,   Df=S_o*Lo((1/Lg1) - (1/lg2))  where S_o = (1-(Lo^2/(Lg1*Lg2)))^-1         
Combining   Df = Lo*( 1 - (Lo^2/(Lg1*Lg2)))^-1 *((1/Lg1)-(1/Lg2))
Or actual code:=($L$311*(1-($L$311^2/($L$312*K318)))^-1)*((1/$L$312)-(1/K318))-J318

like this:
0.844   0.04   6.939544594
0.844   0.05   28.08032721
0.844   0.06   -15.57872833
0.844   0.07   -6.397614737
0.844   0.08   -4.13912597
0.844   0.09   -3.117319973
0.844   0.1   -2.534764749
0.844   0.11   -2.158332745

I think my code is right and the equations are copied fairly but the zero value of Lg2 ~0.052 m, is not close to what we measured and looks to be too small even if the cone tapers all the way to the front end of the cylinder. I am misunderstanding Shawyer's paper is what I think.      
      


Title: Re: EM Drive Developments
Post by: frobnicat on 10/24/2014 12:00 pm
...
Reynolds found that if a porous plate is kept hotter on one side than the other, the interactions between gas molecules and the plates are such that gas will flow through from the cooler to the hotter side. The vanes of a typical Crookes radiometer are not porous, but the space past their edges behaves like the pores in Reynolds's plate. On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. The pressure difference causes the vane to move, cold (white) side forward due to the tangential force of the movement of the rarefied gas moving from the colder edge to the hotter edge.
end quote

This is an interesting effect of another nature. 

<< The vanes of a typical Crookes radiometer are not porous, but the space past their edges behaves like the pores in Reynolds's plate. On average, the gas molecules move from the cold side toward the hot side whenever the pressure ratio is less than the square root of the (absolute) temperature ratio. >>

How would this work for the EM Drive? 

Would we have to posit that the "porous" part is the gap between the flat bases and the surface of the cone?

It is a fact that all the EM Drives that were tested had removable flat bases that were simply torqued into place, they were not welded or bonded without porosity, so certainly one has to admit that there is a gap through which  gas molecules can move (at the circumferential gap of the bases instead of the edges of the blade of the radiometer).

"The space past their edges behaves like the pores in Reynolds's plate" implies the mean free path is a required condition for both to work : the edges thickness and temperature gradients have to be on the order of mean free path length for the effect to be of any significant magnitude. I didn't know the condition between temperature and pressure, but it is well known that the reason why a Crookes radiometer don't turn at ambient pressure is not viscosity (it would turn slower but it would turn) but much smaller mean free path. At STP mean free path is 68nm (http://en.wikipedia.org/wiki/Mean_free_path), much lower any edge/temp. differential. Crookes radiometer works at medium vacuum with mean free path around 1mm, same ballpark as vanes thickness.
This paper (http://arxiv.org/pdf/physics/0402011.pdf) page 2 : "Radiometric forces depend on the mean free path of gas molecules" ... rest of the paper fascinating but no time to read it at the moment.

I don't see any "radiometric" force being detectable at STP even with very sensitive experiments unless devising a geometry with significant temp. differentials at sub µm scales.

On the other hand if there is a gap between the cavity and exterior, the heating of air inside could be very quick (low thermal inertia), and the dilated air would rush through this gap (jet). Me think this could do a small time constant effect, that is compatible with the step observed. But I'm not sure this could go for the magnitude. More on that later (no time right now), want to see the kick one can get from a few litres of air heated a few degrees and expelled through a small aperture ( an involuntary "nozzle" ).
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 12:16 pm
......

I'm reasonably confident that Lo is the RF drive wavelength. .......
I think my code is right and the equations are copied fairly but the zero value of Lg2 ~0.052 m, is not close to what we measured and looks to be too small even if the cone tapers all the way to the front end of the cylinder. I am misunderstanding Shawyer's paper is what I think.

Please take a look at this message:  (  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1271695#msg1271695  )

One problem is in assuming that <<that Lo is the RF drive wavelength >>

Shawyer's Lambdag is the RF drive wavelength instead of Shawyer's Lambda0 (Lo).

Shawyer defines Lambda0  (Lo) as the "free-space propagation wavelength" and makes a difference between the wavelength inside the microwave cavity (which he calls Lambdag) and the wavelength propagation in free space Lambda0 (Lo).

A one-dimensional waveguide restricts the three dimensional "free space" propagation of the electromagnetic wave to a single dimension.  Therefore, the 3-D free-space wavelength is shorter than the wavelength in the microwave guide.

I would expect that, the wavelength in the guide, Lambdag=  Lambda0/cos(phi), where phi is  the angle between the crest lines and the waveguide longitudinal axis.  Since cosine is always less than unity, Lambdag is always greater than Lambda0.  In other words, "RF wavelength" is greater than Lambda0.

Lambdag = RF drive wavelength

Lambdag > Lo

(RF drive wavelength) > Lo

So basically, I don't agree with replacing Lambda0 (Lo) by RF wavelength without taking into account the fact that RF wavelength must be longer than Lambda0 (Lo).
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 12:34 pm
I use the microwave at home and I have never noticed the air getting warm inside it, unlike the air inside my oven.   That's why to get a crust on a pie, I use the oven.

The air inside microwaves is not heated appreciably by microwaves because air molecules aren't as polar as water molecules. Even though the total charge on a molecule is zero, the nature of chemical bonds is such that the positive and negative charges do not completely overlap in most molecules. Such molecules are said to be polar because they possess a permanent dipole moment. Many plastics, glasses and ceramics are labeled "microwave safe" because their molecules are not very polar. 


(http://www.gg.uwyo.edu/media/water/chemistry/diagrams/water_molecules-polar.jpg)

(http://www.elmhurst.edu/~chm/vchembook/images/144o2.GIF)

So, the air inside the EM Drive would have to get heated by convection heat transfer, and the same considerations as in the message http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275630#msg1275630  hold: the copper temperature increases only 1 deg F, and the air needs to get heated by convection from this tiny temperature differential.

The different consideration, is that rather than relying on natural convection circulation, considering the gas law P V=n R T, and since the volume inside the cavity stays the same, as the temperature of the air increases, the pressure increases, and this may produce an air jet at the gap between the bases and the cone.  This would have the advantage of explaining the force always being directed axially regarding of orientation of the EM Drive. 

However:

1) it still would not explain the impulsive response in 2 seconds (at NASA Eagleworks) since heating of air inside the cavity due to convection heat transfer is much slower than that
and
2) the temperature rise of only 1 deg F is so tiny, that, without doing any calculation my intuition would be that this would produce a very small change in pressure and probably not enough to have the EM Drive act as a jet.  On the other hand, the forces measured at NASA Eagleworks are also extremely small (50 microNewtons)



However, although molecules with mirror symmetry like oxygen, and nitrogen have no permanent dipole moments, it is possible to induce a dipole moment by the application of a strong external electric field. This is called polarization and the magnitude of the dipole moment induced is a measure of the polarizability of the molecular species.  One would have to calculate whether the Electric Fields could be strong enough to produce polarization of the air molecules inside the cavity to the extent that the microwave can heat the air molecules so that a pressure would be generated enough to produce a jet with the measured microNewton forces.  Also whether the air inside the cavity could be humid enough to contain enough water molecules for microwave heating to produce this effect.

(http://www.pueschner.com/images/basics/diagram1_eng.gif)
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 02:50 pm
......
I'm reasonably confident that Lo is the RF drive wavelength. .......
I think my code is right and the equations are copied fairly but the zero value of Lg2 ~0.052 m, is not close to what we measured and looks to be too small even if the cone tapers all the way to the front end of the cylinder. I am misunderstanding Shawyer's paper is what I think.
....
Shawyer's Lambdag is the RF drive wavelength instead of Shawyer's Lambda0 (Lo)....

I don't understand why Shawyer's equations are written in terms of the unknown Lambda0 (Lo) instead of the known Lambdag =RF drive wavelength

Shawyer quotes Cullen

"The force on the plate closing the end of the waveguide is": 2* ((PowerInput) / c ) * (Lo / Lambdag)

Since in general

(Lo / Lambdag ) < 1

the force on the plate closing the end of the waveguide  < 2* ((PowerInput) / c )

(Notice the factor of 2 characterizing perfect reflection for the case that all photons bounce of the wall as a perfect mirror and that no photon is absorbed)

Unless one knows Lo, that's all we know: that the force on the plate closing the end of the waveguide  is less than twice the Power Input divided by the speed of light.

Why doesn't Shawyer remove the unknown Lo from the equation ?

Is the unknown Lo left on purpose as a fudge factor (to account for the few photons that do not bounce off the wall but instead dissipate inside the copper as a phonon)?

Isn't the ratio Lo / Lambdag involved in the design factor ? (= 0.844 for the example you gave)

It is actually very close to what is used for solar sails (~90 %)

Perhaps this is another thing Shawyer could answer in addition to what are the actual dimensions of the different EM Drives Shawyer actually used.
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 04:19 pm
Quoting from the linked paper above:

Quote
We now suppose that the beam enters a vacuum-filled waveguide.  The waveguide tapers from free-space propagation, with wavelength L0, to dimensions that give a waveguide wavelength of Lg and propagation velocity vg.

This statement led me to think that L0 was the RF drive wavelength. Or maybe L0 is the diameter of the small end?
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 04:24 pm
Quoting from the linked paper above:

Quote
We now suppose that the beam enters a vacuum-filled waveguide.  The waveguide tapers from free-space propagation, with wavelength L0, to dimensions that give a waveguide wavelength of Lg and propagation velocity vg.

This statement led me to think that L0 was the RF drive wavelength. Or maybe L0 is the diameter of the small end?
That statement says that Lo is the wavelength in free-space propagation and that Lg is the wavelength in the waveguide.   

The subscript "g" stand for waveguide.  The subscript "o" stands for free-space in standard nomenclature.

Lo/Lg < 1

Lg = Lo / Sqrt [1 -( Lo/LcutOff )^2]

where LcutOff  is the upper cutoff wavelength (= c/( lower cutoff frequency ))

Therefore:

Lo =( LcutOff *Lg ) / Sqrt[LcutOff ^2 + Lg ^2 ]


Lo =LcutOff *(RF drive wavelength) / Sqrt[LcutOff ^2 + (RF drive wavelength)^2 ]

For TE01 in a waveguide

LcutOff = 2 * LengthDimension

We have a truncated cone subject to TE0nm modes instead of a simple waveguide subject to TE0n modes, but in absence of a better defined cut-off frequency, and from the writing in Shawyer's, I suggest to adopt the TE01 waveguide cutoff frequency (unless we come up with a better definition for cutoff frequency), giving:

Lo =(2 * LengthDimension)*(RF drive wavelength) / Sqrt[(2 * LengthDimension)^2 + (RF drive wavelength)^2 ]

which is:

Lo =(RF drive wavelength) / Sqrt[1 + ((RF drive wavelength)/(2 * LengthDimension))^2 ]

Lo =(c/(RF drive frequency)) / Sqrt[1 + (c/(2 * LengthDimension * (RF drive frequency)))^2 ]

So only for  RF drive wavelength < <(2 * LengthDimension) , would the equality Lo =(RF drive wavelength) hold in the limit as  ((RF drive wavelength)/(2 * LengthDimension)) -> 0


For example, for RF drive wavelength ~ LengthDimension we have instead:

Lo =0.894 * (RF drive wavelength)
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 05:53 pm

Quote
Lo =0.894 * (RF drive wavelength)

Ok. I'll try that.
---------------------------------------
Now, while reading the above linked paper in detail, I found some Flight Thruster dimensions.

Base plate diameter = 265 mm,
Height = 164 mm.

If those dimensions are consistent with the photograph, then we should be able to extract the small end dimension.
---------------------------------------
I plugged in Rodel's value of Lo. It moved the zero crossing slightly, but to the left.
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 06:18 pm

Quote
Lo =0.894 * (RF drive wavelength)

Ok. I'll try that.
---------------------------------------
Now, while reading the above linked paper in detail, I found some Flight Thruster dimensions.

Base plate diameter = 265 mm,
Height = 164 mm.

If those dimensions are consistent with the photograph, then we should be able to extract the small end dimension.
---------------------------------------
I plugged in Rodel's value of Lo. It moved the zero crossing slightly, but to the left.

What is the "DesignFactor" you compute for smallDiameter=0.17 m, bigDiameter=0.28 m and length=0.345 m ?

I get a DesignFactor = 0.401



For DesignFactor = 0.844  and bigDiameter=0.28 m and length=0.345 m

I get smallDiameter = 0.1289 m which is much larger than the values you showed, and not so far off from 0.17 m

Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 06:27 pm
Quote
Now, while reading the above linked paper in detail, I found some Flight Thruster dimensions.

Base plate diameter = 265 mm,
Height = 164 mm.

If those dimensions are consistent with the photograph, then we should be able to extract the small end dimension.

The paper also gives the mass of the thruster as 2.92 kg.

If we assume that the base plate is that bottom plate in contact with the table top, and that the height is the distance from the table top to the top surface (where you'd set your coffee cup) then maybe we can estimate the internal dimensions to calculate the thickness of the sidewalls of the thruster. But is it aluminum or stainless? Either way I speculate that the inner surface is plated with silver, gold or maybe copper. The internal plating shouldn't detectably affect the mass though or having rough internal dimensions, we could also estimate the plating mass using the skin thickness at 3.86 GHz.

And in this, by "we" I mean, "you."  :)
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 06:38 pm
Quote
What is the "DesignFactor" you compute for smallDiameter=0.17 m, bigDiameter=0.28 m and length=0.345 m

For DesignFactor = 0.844  and bigDiameter=0.28 m and length=0.345 m

I get smallDiameter = 0.1289 m which is much larger than the values you showed, and not so far off from 0.17 m
All my dimension estimates were from measuring the Photos. And my design factor equation is not working.
If I plug Lg1=.28 and Lg2=.17 into my current (broken?) spread sheet formula, I get Df =-0.337700803. That is negative and length doesn't enter into my version of the design factor equation.
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 06:50 pm
This is the equation (obtained from inverting the Shawyer designFactor formula) for the smallDiameter in terms of the other variables:

If you plug in:

c = 299792458 m/s
rfFrequency = 2.45 * 10^9 1/s
bigDiameter=0.28 m
demoCavityLength=0.345 m
DesignFactorNumber = 0.844

you should get:

smallDiameter = 0.128887 m

Equation  © Rodal 2014
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 07:03 pm
And this is what a plot of SmallDiameter (m) in the vertical axis vs. DesignFactor in the horizontal axis looks like
Observe that for DesignFactor = 0, SmallDiameter = BigDiameter, which makes sense
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 07:12 pm
I like the value you calculate for the small diameter. But can that length be right? I suppose so. Using that length, big diameter and the taper from the photo I calculate small diameter about 0.1 meter. Close enough considering the uncertainty in just exactly where Shawyer is measuring when he tells us the diameter of the thruster and we don't know the wall thickness either. The equations are all related to the internal dimensions while photos show external dimensions and it's all based on assuming we know what Shawyer measured to get the published number.

Oh. Would you post your design factor equation in it's normal form? I'd like to put it into my spreadsheet to see what the curve looks like and to confirm your number.
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 07:14 pm
I like the value you calculate for the small diameter. But can that length be right? I suppose so. Using that length, big diameter and the taper from the photo I calculate small diameter about 0.1 meter. Close enough considering the uncertainty in just exactly where Shawyer is measuring when he tells us the diameter of the thruster and we don't know the wall thickness either. The equations are all related to the internal dimensions while photos show external dimensions and it's all based on assuming we know what Shawyer measured to get the published number.

Oh. Would you post your design factor equation in it's normal form? I'd like to put it into my spreadsheet to see what the curve looks like and to confirm your number.
What do you mean by normal form of equation?  It looks very normal to me.   :)

If you like to put the equation in some other form, I'll be glad to check your interpretation, if you define your variables so that I understand your interpretation. :)
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 07:36 pm
I mean in the form Design factor = expression.
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 07:47 pm
I mean in the form Design factor = expression.
Here is Shayer's DesignFactor in terms of the other variables, notice that it goes to zero when BigDiameter=SmallDiameter
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 08:39 pm
New blog page from Dr. McCulloch explaining Unruh-radiation inertia-modification in simple terms:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-motion-from-logic.html
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 08:48 pm
Table comparing Shawyer and McCulloch's predictions with measurements

c=299792458 m/s

lengths in meter
frequency in 1/second
power in watts
force in milliNewtons

predicted force (either Shawyer or McCulloch) followed (in parenthesis) by ratio of prediction divided by measurement

ShawyerForce = (2 * PowerInput * Q / c ) * designFactor

McCullochForce = ( PowerInput * Q / c ) * ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))


Force/PowerInput of a Photon Rocket = 1 / c

Therefore, the Force/PowerInput ratios divided by the Force/PowerInput of a Photon Rocket are:

Shawyer/PhtnRckt = 2 * Q * designFactor
McCulloch/PhtnRckt = Q * ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))





(* Shawyer Experimental *)
rfFrequency=2.45*10^9;
cavityLength=0.156;
bigDiameter=0.16;
smallDiameter=0.11;
designFactor= 1.23205

power =  850   
Q = 5900

measured force = 16
ShawyerForce = 41 (2.56)
McCullochForce = 7  (0.438)


(* Shawyer Demo *)  BEST PREDICTED VALUES
rfFrequency=2.45*10^9;
cavityLength=0.345;
bigDiameter=0.28;
smallDiameter=0.17;
designFactor =0.400601

power =  1000
Q = 45000

measured force = 147
ShawyerForce =  120 (0.816)
McCullochForce = 123 (0.837)          


(* Shawyer Demo *)
rfFrequency=2.45*10^9;
cavityLength=0.345;
bigDiameter=0.28;
smallDiameter=0.129;
designFactor =0.842138

power =  1000
Q = 45000

measured force = 147
ShawyerForce =  253 (1.72)
McCullochForce = 216 (1.47)



All Brady cases have the following dimensions:

cavityLength=0.332;
bigDiameter=0.397;
smallDiameter=0.244;


(* Brady a *)
rfFrequency=1.933*10^9;
designFactor =0.31201

power =   16.9 
Q = 7320

measured force =  0.09
ShawyerForce =  0.26 (2.89)
McCullochForce = 0.22 (2.44)


(* Brady b *)  STATISTICAL OUTLIER
rfFrequency=1.937*10^9;
designFactor =0.311024

power = 16.7
Q =  18100

measured force = 0.05
ShawyerForce =  0.63 (12.6)
McCullochForce = 0.53 (10.6)


(* Brady c *)
rfFrequency=1.88*10^9;
designFactor =0.325756

power = 2.6
Q = 22000

measured force = 0.06
ShawyerForce =  0.12 (2.00)
McCullochForce = 0.10 (1.67)


Formula for designFactor in term of other variables
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 08:56 pm
Using your equation I also get 0.129 m for the demo small end. Now we only need confidence in the 0.345 m length measurement. Where did that value originate?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/24/2014 09:41 pm
Dimensions are bigger than those used in my program. Are things settled ? Sorry I haven't followed the designFactor parameter : "Formula for designFactor in term of other variables" is it dependent or independent ??

I may have time this week-end to do new runs on updated values and added parameters, but I don't want composite (dependent) parameters as this would add duplicates. Independent parameters (like length) can be safely added. If special functions need to be added to generate relevant dependant parameters it's also possible. Can anyone take the responsibility and time to summarize a consensus in the following format ?
(changing the number of columns and labels as see fit). Will make available the results as spreadsheet.


#define Nrec 6
t_data data_in[Nrec] =
{
    //                                 w_big  w_small  lambda      Q     power   force
    {"Shawyer (2008) a",        1.0 ,  16    ,  8    , C/2.45  ,  5900 ,  850   , 16       },
    {"Shawyer (2008) b",        1.0 ,  28    ,  4    , C/2.45  , 45000 , 1000   , 214      },
    {"Juan (2012) TE011",       1.0 ,  28    ,  4    , C/2.5   , 32000 , 1000   , 214      },
    {"Juan (2012) TE012",       1.0 ,  28    ,  4    , C/2.45  , 50000 , 1000   , 315      },
    {"Brady et al. (2014) a",   1.0 ,  24.75 , 16.5  , C/1.933 ,  7320 ,   16.9 ,   0.0912 },
    {"Brady et al. (2014) c",   1.0 ,  24.75 , 16.5  , C/1.88  , 22000 ,    2.6 ,   0.0554 },
};



I'm trying to build a case for Brady a with thermal air jet : do we agree on inner volume approx. that of a truncated cone length 0.33  big diameter .4 small diameter .24  (I'm not into a few %) that is approximately 27 litres (27000 cm^3), equivalent to a cube of 30cm side ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 09:43 pm
.....
I'm trying to build a case for Brady a with thermal air jet : do we agree on inner volume approx. that of a truncated cone length 0.33  big diameter .4 small diameter .24  (I'm not into a few %) that is approximately 27 litres (27000 cm^3), equivalent to a cube of 30cm side ?

I will do what you ask (unless somebody else wants to do it), but I think that it would be better to wait until we settle on dimensions, there are still issues to be discussed with John (both beams) and aero.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/24/2014 09:46 pm
I will do what you ask (unless somebody else wants to do it), but I think that it would be better to wait until we settle on dimensions, there are still issues to be discussed with John (both beams) and aero.

All right, better have best data.
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 10:11 pm
Ok - What dimensions are we currently questioning?
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 10:23 pm
Ok - What dimensions are we currently questioning?
All of them.  Take a look at my table above.  The predictions are closest for the Shayer demo when using the AutoCad drawing from JohnFornaro.

They are off by more than a factor of 2 if we estimate the Shawyer demo small diameter based on the other Fornaro dimensions and the 0.844 designFactor.

John Fornaro based his dimensioning for the NASA Eagleworks on the back beam cross section, and not the front one, so the NASA Eagleworks dimensions should be reviewed.
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 10:38 pm
Ok - What dimensions are we currently questioning?
All of them.  Take a look at my table above.  The predictions are closest for the Shayer demo when using the AutoCad drawing from JohnFornaro.

They are off by more than a factor of 2 if we estimate the Shawyer demo small diameter based on the other Fornaro dimensions and the 0.844 designFactor.

John Fornaro based his dimensioning for the NASA Eagleworks on the back beam cross section, and not the front one, so the NASA Eagleworks dimensions should be reviewed.

Those dimensions do not include length, which Prof. M now needs. I hope your records are better than mine because I don't have lengths recorded, (or the other dimensions, for that matter.)
Title: Re: EM Drive Developments
Post by: Rodal on 10/24/2014 10:48 pm
...I hope your records are better than mine because I don't have lengths recorded, (or the other dimensions, for that matter.)
The "search" function of this thread is really awful.  Too bad that this thread does not use Google as a search engine
Title: Re: EM Drive Developments
Post by: frobnicat on 10/24/2014 10:51 pm
I use the microwave at home and I have never noticed the air getting warm inside it, unlike the air inside my oven.   That's why to get a crust on a pie, I use the oven.

Yes but you don't use microwave oven empty (you shouldn't) and putting an absorbing water containing thing in it degrades its Q factor.
Quote
The quality factor of an empty microwave oven (30 × 30 × 20 cm^3), with penetration depth of the walls δ≈1μm, is of the order of 10^4, while when we put a glass of water inside the chamber the quality factor is of the order of 10^2. If we put more water in the chamber, the quality factor would be lower and the absorption would be greater.
From this publication (http://mafija.fmf.uni-lj.si/seminar/files/2008_2009/Absorption_of_microwaves_in_food.pdf) page 8.

Can't believe I'm posting about details of household microwave ovens on advanced concepts...

.../...
So, the air inside the EM Drive would have to get heated by convection heat transfer, and the same considerations as in the message http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275630#msg1275630  hold: the copper temperature increases only 1 deg F, and the air needs to get heated by convection from this tiny temperature differential.

If this is the only way air inside cavity can be heated then yes.

Quote
The different consideration, is that rather than relying on natural convection circulation, considering the gas law P V=n R T, and since the volume inside the cavity stays the same, as the temperature of the air increases, the pressure increases, and this may produce an air jet at the gap between the bases and the cone.  This would have the advantage of explaining the force always being directed axially regarding of orientation of the EM Drive. 

That's the idea.

Quote
However:

1) it still would not explain the impulsive response in 2 seconds (at NASA Eagleworks) since heating of air inside the cavity due to convection heat transfer is much slower than that

Unless...

Quote
and
2) the temperature rise of only 1 deg F is so tiny, that, without doing any calculation my intuition would be that this would produce a very small change in pressure and probably not enough to have the EM Drive act as a jet.  On the other hand, the forces measured at NASA Eagleworks are also extremely small (50 microNewtons)

That's my intuition also, too small, but working on quantitative estimations to be sure.

Quote
However, although molecules with mirror symmetry like oxygen, and nitrogen have no permanent dipole moments, it is possible to induce a dipole moment by the application of a strong external electric field. This is called polarization and the magnitude of the dipole moment induced is a measure of the polarizability of the molecular species.  One would have to calculate whether the Electric Fields could be strong enough to produce polarization of the air molecules inside the cavity to the extent that the microwave can heat the air molecules so that a pressure would be generated enough to produce a jet with the measured microNewton forces.  Also whether the air inside the cavity could be humid enough to contain enough water molecules for microwave heating to produce this effect.

Can't tell for a polarisation of oxygen and nitrogen, but usual air sure has water content, a good fraction of a % by weight. As water molecules are dispersed they could heat the rest of the air mass, if only they can couple enough to get a fraction of microwave energy. We are inside a cavity that's designed to have a high Q, the losses on the walls are minimised (by being copper of or gold and presumably by being polished) but at the end all the power injected in has to go somewhere. The power pumped into makes a significant stored energy level before losses equal input, photons go back and forth a lot of time (high Q) and have all that much chances to interact with water molecules.

I have a hard time finding accessible information of water vapor coupling with GHz microwaves. There is a nice graph on this wikipedia entry (http://en.wikipedia.org/wiki/Electromagnetic_absorption_by_water#Microwaves_and_Radio_Waves) stating that "The pure rotation spectrum of water vapor extends into the microwave region" but the graph is apparently for liquid water (and shows a decrease in coupling when hotter).

So surely water vapor in usual lab air gets heated by microwaves, and this heating (and subsequent heating of air) would be fast, no conduction or convection required + small thermal inertia. By how much would it be heated, in a high Q empty "microwave oven" at about 20 W  (Brady a) is the question I can't answer.

That said, apparently Brady a reported Q of 7320 has nothing exceptional compared to above citation of 10^4 for empty microwave ovens.
Title: Re: EM Drive Developments
Post by: aero on 10/24/2014 11:49 pm
Just for giggles I calculated the sensitivity (numerically) of Force to the dimensional parameters. I used Prof. M's new equation on Shawyer a" to calculate force. I used delta X = 2%.

             dF/dX          dF/dX
for X     mN/meter    mN/cm
        =s    47.523     0.475
  =w-big    101.979     1.020      
=w-small    215.756     2.158

No real surprise but in general centimeter sized errors in dimensions are noticeable.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 12:32 am
Just for giggles I calculated the sensitivity (numerically) of Force to the dimensional parameters. I used Prof. M's new equation on Shawyer a" to calculate force. I used delta X = 2%.

             dF/dX          dF/dX
for X     mN/meter    mN/cm
        =s    47.523     0.475
  =w-big    101.979     1.020      
=w-small    215.756     2.158

No real surprise but in general centimeter sized errors in dimensions are noticeable.

I calculated the derivatives dF/dX for Shawyer's design factor with respect to all the same three variables.

dF/dX (where X is either the smallDiameter or the bigDiameter) goes to infinity as the small diameter approaches the big diameter.

The value of the derivatives depend on all three variables.

Let me know if you are interested, I can post the formulas.

I could plot them, but since the derivatives are a function of all three variables, in a 3-D plot I need to arbitrarily fix one of the variables to an arbitrary value to be able to plot the derivative as a function of the other two.

For example,  I can plot dF/dsmallDiameter as a function of small diameter and big diameter for a given value of cavity length.

The derivatives of Shawyer's design factor have a similar dependence as the ones you found for McCulloch's.
Title: Re: EM Drive Developments
Post by: aero on 10/25/2014 01:00 am
Yes, I know that in the design none of the geometry variables are independent. That is, they are all interdependent. What I was showing is the effect of measurement error from the photographs. Those errors can be considered to be more or less independent of each other.

Measurement errors are mostly dependent on where we estimate the corners of the 2-d view of the cavity to be, then errors in the reference length be it from the image (Brady) or literature (Shawyer).
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 01:20 am
Yes, I know that in the design none of the geometry variables are independent. That is, they are all interdependent. What I was showing is the effect of measurement error from the photographs. Those errors can be considered to be more or less independent of each other.

Measurement errors are mostly dependent on where we estimate the corners of the 2-d view of the cavity to be, then errors in the reference length be it from the image (Brady) or literature (Shawyer).
Yes, I got that.  Actually for the Shawyer design factor I get that the most sensitive parameter is the small diameter, about 2 to 3 times more than the big diameter and the big diameter about 10 times more sensitive than the length which is the least sensitive parameter.  Too bad that we were not given the small diameter and we have to estimate, since that is the most sensitive parameter.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 01:57 am
...I hope your records are better than mine because I don't have lengths recorded, (or the other dimensions, for that matter.)
The "search" function of this thread is really awful.  Too bad that this thread does not use Google as a search engine

Correction.  The Search function on this site sux. The googol sdearch engine is slightly and only slightly better.

And this is from ma guy who has just arrived home from a productive visit with his mixologist.  The english language and its capability for explanation has been derided on this thead by the math elite, to no pragmatic avail. If it can't be said in English, then the math ain't all that valuable.  But don't get me started on the value of meaning outside the mathematical paradigme.

I will take another stab at the dimesnsional analysis.  Soon, but no sooner than I feel like.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/25/2014 01:58 am
Seems to me we'd be further along here if the researchers had posted the dimensions of these devices in the first place.  As it is, we are taking a 'best guess' approach.

That said...been trying to think a wrong idea through here. 

Ok, we have a truncated copper cone, with a microwave emitter at the small end.  Interior of the cone is polished.

Photons do not have mass, but do have inertia, which they can transfer to other objects (which is why Solar Sails work).

A photon must move at C (light-speed) - if it moves less than C, it stops being a photon.  (Is this right?)

So, to follow the initial path of a single photon in the device and its effects.

1) Photon leaves emitter.  Question: is there recoil?

2) Photon travels through the middle of the cone, hits the large flat (?) base of the cone.  As per a solar sail, the photons inertia (momentum) is transferred to the cone.  Then, instead of sticking, photon bounces.  If there is recoil in step 1, then said recoil should be cancelled or mostly cancelled at this point.

3) So photon flies back from the flat base of the cone, and hits the cone wall - which is both curved and angled.  The impact still transfers momentum, but NOT in the exact opposite direction of the impact in step 2.  Instead, the angle and curvature of the cone dictate that a good portion of the released force will be at an angle, maybe even sideways (along the cones curve).  (in open space, without constraints, would enough such impacts cause the cone to rotate?).  Anyhow, photon bounces again, towards the base.

4) photon hits base, which being flat, lets the photon transfer all or most of its momentum a second time, before bouncing back to the cone wall, repeating step 3.


Or...most/all photons hitting the cones base, regardless of direction, or number of times, contribute to forward force. 
And most/all photons hitting the cone wall expend at least part of their energy in a 'sideways' direction.

Except this means a violation of the laws of thermodynamics and a cop named Maxwell is trying to write me a ticket.

Put a nozzle (opening in the cavity) in there somewhere (near the emitter), and you might have a turbocharged photon rocket.     
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 02:05 am
If this is the only way air inside cavity can be heated then yes.

I can vouch for the phenomena that M/W air gets filled with warm water vapor, from hitting the 'potato' button the other day.  The air in the M/W was warm and moist, due to potato water that had been evaporated by the influx of M/W energy.  The moist air dispersed with the opening of the M/W door.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 02:08 am
`
Seems to me we'd be further along here if the researchers had posted the dimensions of these devices in the first place.  As it is, we are taking a 'best guess' approach.

See my remark on the reflection upon the experimentors WRT the easy questions that have been asked.  The experimentors can only be said to mock the real efforts to understand that are mede on this thread.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 02:21 am
If this is the only way air inside cavity can be heated then yes.

I can vouch for the phenomena that M/W air gets filled with warm water vapor, from hitting the 'potato' button the other day.  The air in the M/W was warm and moist, due to potato water that had been evaporated by the influx of M/W energy.  The moist air dispersed with the opening of the M/W door.

Do you think that the NASA experimenters left some moist potatoes or something similar inside these cavities by accident?

You give me the material...I work with it ...
Title: Re: EM Drive Developments
Post by: aero on 10/25/2014 03:21 am
Probably just warming cold coffee.
-------------------
@Rodal - Is it possible to model Q analytically for an RF frequency and cavity geometry?

If so, then you could maximize the whole thing, F = PQs/c * ((1/w_big)-(1/w_small)) given an operating frequency. Of course as has been said, a good resonate cavity does not automatically mean a good thruster.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/25/2014 04:56 am
Hmmm...a low voltage DC 'lifter'?

http://www.youtube.com/watch?v=IkNrNFAU4So

could this be the culprit behind the EM Drive?

Maybe somebody here could build such a device...
Title: Re: EM Drive Developments
Post by: frobnicat on 10/25/2014 12:59 pm
Begin Youtube style comment :
   Ha ha, what a good joke! Could tell where the thin invisible wire was attached though...
End Youtube style comment
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 01:38 pm
If this is the only way air inside cavity can be heated then yes.

I ... [hit] the 'potato' button the other day.  ...

Do you think that the NASA experimenters left some moist potatoes or something similar inside these cavities by accident?

You give me the material...I work with it ...

I keep saying that the material you seek to work with is CHBW, which work best when dry.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 01:39 pm
...could this be the culprit behind the EM Drive?...

I'm not a Scot, so I cannae work on that druve,
Title: Re: EM Drive Developments
Post by: frobnicat on 10/25/2014 02:24 pm
First attempt to model thrust from cavity's air volumetric heating and jet effect through small aperture. Case studied : Brady a.

Model needs refining (please be patient) but first rough estimates put in the ballpark of 100µN effect during 30s with fast rise of 2s. For now I will give numerical values and derive feasibility from them, in reverse from the set of general equations from which those values derive because I'm still struggling to put some order with all parameters and dependences. Also I want a clean differential equation, takes some time.

Needed hypothesis : air inside cavity is volumetrically heated at Pow=4W (that is, air gets around 25% of microwave power input). There are hole(s) or crevice(s) between cavity and exterior of device, in the direction of thrust (air jetting...) for a total area of A=1.6 mm².

Mind you, volumetric air heating Pow=4W and hole area A=1.6mm² are unknowns, so these values were carefully chosen to get to some magnitude to explain... not the other way around.

Temperatures around 20°C  T = 293K
Cavity volume V = 0.027 m^3
Initial mass of air m = rho*V = 1.2 * .027 = .0324 kg (32 grams of air)
Assuming some air will be leaving but only a small part of that, so not significantly alter the heat capacity of the whole. Heat capacity supposed constant.

We put 4W of power into that, with a specific heat of  C=1000J/kg/K  Tdot = Pow / ( C * m ) = 0.123 K/s

Consider first a short transient period with pressure buildup (like the hole is closed), m constant, p*V=m*Rs*T (Rs around 287 J/kg/K for air)
pdot = m*Rs/V *Tdot = 42 Pa/s  (Pascals per second, please remember there is 10^5 Pa in one atm. pressure). So in 2s we would reach 84 Pa more pressure inside vessel than outside. Note that Tdot uses an isobar value of C (1000) while strictly in this phase we would be in isochore conditions (C=720) : that would only lower the time. So in less than 2 seconds 84 Pa differential. Pd = 84 Pa.

This is the transient. At this level of pressure differential the rate of air escaping through the hole becomes important enough that this pressure will be kept constant while the temperature continues to rise (why I choose isobar heat capacity overall) :
The mass flow through aperture mdot = Cf A sqrt(2 rho Pd) where Cf is a flow coefficient depending on geometry and I understand is around 0.6 for rough holes.
This is from orifice plate article on wikipedia (http://en.wikipedia.org/wiki/Orifice_plate) (repress any second thought here), I took the most simplified forms assuming incompressible flow (pressure differential / absolute pressure < 1/1000 so I guess this is a good first approximation). On this chapter (http://en.wikipedia.org/wiki/Orifice_plate#Incompressible_flow), equation (2).

=> mdot = 1.36 10^-5 kg/s  of air expelled through the 1.6 mm² hole(s).
This is a volume flow of mdot/rho = 1.13 10^-5 m^3/s
Speed of ejection is volume flow divided by hole section : v = 7.1 m/s
Clearly not sonic or supersonic.

The reaction force imparted (thrust) = mdot * v = 9.65 10^-5
Thrust = 96 µN

Reported by Brady a : 91.2 µN

After 30 seconds of this "steady state" of constant rate of heating and expelling air :
T would be 3.7 ° above initial conditions
Mass of air expelled 0.41 g (a bit more than 1% of initial air mass of 32g)

Sanity check on total momentum :
From momentum expelled by jet : 0.41e-3 kg * 7.1 m/s = 2.9e-3 kg m/s
From required thrust during 30s : 96e-6 N * 30 s = 2.9e-3 kg m/s

When power off, Tdot falls to 0, sharp fall to 0 thrust ( differential pressure is quickly released, pressure equilibrium restored with same time constant as rise time < 2s). Conduction slowly release the heat of gas through the (colder) copper walls with a long time constant. No visible effect of contracting gas sucking air through the hole(s) when restoring T equilibrium.

Thank you for your patience.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 02:40 pm
Needed hypothesis : air inside cavity is volumetrically heated at Pow=4W (that is, air gets around 25% of microwave power input). There are hole(s) or crevice(s) between cavity and exterior of device, in the direction of thrust (air jetting...) for a total area of A=1.6 mm².

I would say that the perimeter of the big end leaks.  Not sure how you'd model that leaky connection of the PCB to the copper frustrum flange.

At any rate (rate?  get it?) the warm jets (http://www.youtube.com/watch?v=iw_sxh89Fos) are coming out radially at right angles to the thrust axis of the thingy.

[Hint from the inappropriate humor department:  Listener maximizes humor by familiarity with Brian Eno's album cover art.  Linked artwork is not true color, but that's immaterial.]
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 03:01 pm
Needed hypothesis : air inside cavity is volumetrically heated at Pow=4W (that is, air gets around 25% of microwave power input). There are hole(s) or crevice(s) between cavity and exterior of device, in the direction of thrust (air jetting...) for a total area of A=1.6 mm².

I would say that the perimeter of the big end leaks.  Not sure how you'd model that leaky connection of the PCB to the copper frustrum flange.

At any rate (rate?  get it?) the warm jets (http://www.youtube.com/watch?v=iw_sxh89Fos) are coming out radially at right angles to the thrust axis of the thingy.

[Hint from the inappropriate humor department:  Listener maximizes humor by familiarity with Brian Eno's album cover art.  Linked artwork is not true color, but that's immaterial.]

<< are coming out radially at right angles to the thrust axis of the thingy.>>
A=1.6 mm² leaking could be axial due to the gap between the bolts and the boltholes

1.6 mm² is only 0.0025 square inches or a square having 0.05 inches per side

Look deeply, look at all those bolts.  I count 24 bolts, so this would be a gap of only 0.0001 square inches per bolt

24 nozzles of big end escaping gas
Title: Re: EM Drive Developments
Post by: frobnicat on 10/25/2014 03:21 pm
Needed hypothesis : air inside cavity is volumetrically heated at Pow=4W (that is, air gets around 25% of microwave power input). There are hole(s) or crevice(s) between cavity and exterior of device, in the direction of thrust (air jetting...) for a total area of A=1.6 mm².

I would say that the perimeter of the big end leaks.  Not sure how you'd model that leaky connection of the PCB to the copper frustrum flange.

At any rate (rate?  get it?) the warm jets (http://www.youtube.com/watch?v=iw_sxh89Fos) are coming out radially at right angles to the thrust axis of the thingy.

[Hint from the inappropriate humor department:  Listener maximizes humor by familiarity with Brian Eno's album cover art.  Linked artwork is not true color, but that's immaterial.]

<< are coming out radially at right angles to the thrust axis of the thingy.>>
A=1.6 mm² leaking could be axial due to the gap between the bolts and the boltholes

1.6 mm² is only 0.0025 square inches or a square having 0.05 inches per side

Look deeply, look at all those bolts.  I count 24 bolts, so this would be a gap of only 0.0001 square inches per bolt

Or the seam that appear on the side of cone (assuming it's not welded). If leaks are not perfectly axial there would still be a net thrust but with a lower efficiency (cosine of the angle relative to axis). The magnitude jet effects can get are pretty close what is to be explained, would be hard to account for less than ideal jet directions... yet it's tantalizingly close. Equations together (will try to summarize that this week-end) can give higher thrust with lower leak area but at the price of higher time constant to reach delta pressure equilibrium (more than 2s).

Also a jet that would come out a seam between two planes perpendicular to axis would have a significant axial component when the flange is asymmetric (for instance the copper part ends when the PCB extends a little bit further...)

In what direction (average) the jets would have to go ? I'm still all confused with the thrust directions.

The big caveat : 4W volumetric heating of (presumably not perfectly dry) air out of 16W microwave power in "empty oven".
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 03:22 pm
It is incorrect to state that only DC fields can produced ionic winds.  I don't know whether such misunderstanding comes from getting information from Wikipedia.

AC fields can also produce ionic wind in a variety of ways.  For example, the point electrode and ring electrode system is capable of generating electric winds (with velocities of few m/s) for both DC and AC applied voltages.  In the AC regime, ions generated within the corona move in the field and migrate a distance before recombining; the net flow of ions away from the corona creates a time-averaged force that drives the steady flows.  AC coronas can sustain wind velocities of over 1m/s independent of electrode separation in marked contrast to DC coronas.

Another arrangement in which AC fields can produce ionic wind is dielectric barrier discharge actuators.  AC applied across the electrodes through the dielectric produces a variety of electric breakdown phenomena (e.g., corona, streamers, and plasma).  Spark breakdown is prevented by the dielectric barrier.  The dielectric material needs to be in contact with electrodes such that the electrodes contact each surface of the dielectric.

Transient migration of charged species within AC fields also gives rise to steady electric winds.

In contrast to winds driven by DC fields, AC fields (as in the point electrode and ring electrode system ) generate wind velocities comparable with (or better than) the strongest DC winds for any value of the electrode separation.  In the high-frequency  AC regime (>1 KHz), the electric force is localized within a region near the tip of the point electrode. 

From a fundamental perspective, any type of electric wind (DC or AC) derives from the same basic mechanism whereby a steady flux of ions transfers momentum to the surrounding fluid to drive steady gas flows.

No it isn't because I'm some (as you're eluding to) unsophisticated Wikipedia scholar. The subject matter in which I discuss is a matter of my career, waveguides and electronics, informed by my practical experience from being on the job. You know how much flack I gave Ron about posting links to info on Wikipedia. My reference to high voltage DC is strictly to mention that you need high voltage in order to create the corona effect you enjoy from ionizing air. I've worked with a lot of high voltage power supplies up to =15Kvdc and with a simultaneous -6Kvdc.....and none of them were ever AC high voltage power supplies. Not even 1 AC high voltage power supply, because the utility of a high voltage AC power supply isn't useful for biasing tubes or anything else. You can literally feel and smell the ionized air in the vicinity of a charged HVPS. High voltage is the sole reason those lifters work. This isn't applicable to emdrive, hence why I said we can rule out ion wind with emdrive.

If one were to use an AC high voltage power supply, there wouldn't be an ion wind, just an ion wind oscillation.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 03:31 pm
I recall that Paul March wrote that the EMDrives tested at NASA Eagleworks had a temperature that never rose more than 1 deg (F ? or C?) above room temperature.

Anybody recall that statement?  Is the temperature measurement in the NASA Eagleworks report? Using search I cannot find it in the text.  Is it in the pictures?

I also recall AcesHigh reporting on information elsewhere reporting March's statement he made on this thread regarding temperature.  Was that at nextbigfuture? Does anybody still have a link for that?

Yes I remember March saying the temperature didn't rise more than 1 degree F. It was F, not C.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 03:32 pm
It is incorrect to state that only DC fields can produced ionic winds.  I don't know whether such misunderstanding comes from getting information from Wikipedia.

AC fields can also produce ionic wind in a variety of ways.  For example, the point electrode and ring electrode system is capable of generating electric winds (with velocities of few m/s) for both DC and AC applied voltages.  In the AC regime, ions generated within the corona move in the field and migrate a distance before recombining; the net flow of ions away from the corona creates a time-averaged force that drives the steady flows.  AC coronas can sustain wind velocities of over 1m/s independent of electrode separation in marked contrast to DC coronas.

Another arrangement in which AC fields can produce ionic wind is dielectric barrier discharge actuators.  AC applied across the electrodes through the dielectric produces a variety of electric breakdown phenomena (e.g., corona, streamers, and plasma).  Spark breakdown is prevented by the dielectric barrier.  The dielectric material needs to be in contact with electrodes such that the electrodes contact each surface of the dielectric.

Transient migration of charged species within AC fields also gives rise to steady electric winds.

In contrast to winds driven by DC fields, AC fields (as in the point electrode and ring electrode system ) generate wind velocities comparable with (or better than) the strongest DC winds for any value of the electrode separation.  In the high-frequency  AC regime (>1 KHz), the electric force is localized within a region near the tip of the point electrode. 

From a fundamental perspective, any type of electric wind (DC or AC) derives from the same basic mechanism whereby a steady flux of ions transfers momentum to the surrounding fluid to drive steady gas flows.
.....
If one were to use an AC high voltage power supply, there wouldn't be an ion wind, just an ion wind oscillation.
Anybody in this thread that wants correct information on ionic wind produced by AC, please read for example:

"Electric winds driven by time oscillating corona discharges"
JOURNAL OF APPLIED PHYSICS 114, 143302

Aaron M. Drews,1 Ludovico Cademartiri,2,3,4,5 George M. Whitesides,2,6
and Kyle J. M. Bishop1,a)
1Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802,
USA
2Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
3Department of Materials Science & Engineering, Iowa State University, Ames, Iowa 50011, USA
4Department of Chemical & Biological Engineering, Iowa State University, Ames, Iowa 50011, USA
5Ames Laboratory, US Department of Energy, Ames, Iowa 50011, USA
6Kavli Institute, Harvard University, Cambridge, Massachusetts 02138, USA

http://gmwgroup.harvard.edu/pubs/pdf/1194.pdf

<<Transient migration of charged species within AC fields also gives rise to steady electric winds>>
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 03:36 pm
You.  Play nice.

...I don't know whether such misunderstanding comes from getting information from Wikipedia. ...

You.  Get a dictionary.

No it isn't because I'm some (as you're [alluding] to) unsophisticated Wikipedia scholar.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 03:37 pm
Needed hypothesis : air inside cavity is volumetrically heated at Pow=4W (that is, air gets around 25% of microwave power input). There are hole(s) or crevice(s) between cavity and exterior of device, in the direction of thrust (air jetting...) for a total area of A=1.6 mm².

I would say that the perimeter of the big end leaks.  Not sure how you'd model that leaky connection of the PCB to the copper frustrum flange.

At any rate (rate?  get it?) the warm jets (http://www.youtube.com/watch?v=iw_sxh89Fos) are coming out radially at right angles to the thrust axis of the thingy.

[Hint from the inappropriate humor department:  Listener maximizes humor by familiarity with Brian Eno's album cover art.  Linked artwork is not true color, but that's immaterial.]

<< are coming out radially at right angles to the thrust axis of the thingy.>>
A=1.6 mm² leaking could be axial due to the gap between the bolts and the boltholes

1.6 mm² is only 0.0025 square inches or a square having 0.05 inches per side

Look deeply, look at all those bolts.  I count 24 bolts, so this would be a gap of only 0.0001 square inches per bolt

Or the seam that appear on the side of cone (assuming it's not welded). If leaks are not perfectly axial there would still be a net thrust but with a lower efficiency (cosine of the angle relative to axis). The magnitude jet effects can get are pretty close what is to be explained, would be hard to account for less than ideal jet directions... yet it's tantalizingly close. Equations together (will try to summarize that this week-end) can give higher thrust with lower leak area but at the price of higher time constant to reach delta pressure equilibrium (more than 2s).

Also a jet that would come out a seam between two planes perpendicular to axis would have a significant axial component when the flange is asymmetric (for instance the copper part ends when the PCB extends a little bit further...)

In what direction (average) the jets would have to go ? I'm still all confused with the thrust directions.

The big caveat : 4W volumetric heating of (presumably not perfectly dry) air out of 16W microwave power in "empty oven".

The problem: dependence on Q

As I understand it, to heat the air inside the cavity by microwave heating the air needs to have water molecules (it needs to be humid) because the gases in air are non-polar (nitrogen, oxygen, etc.) and hence do not get heated by the microwaves.

But, the more humid the air, the lower the Q.  Hence one would expect an inverse relation between measured force and Q: the higher the Q the smaller the force.

However, statistical examination of all the data (Shawyer and NASA Eagleworks) points in the other direction: the higher the Q the greater the measured force.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/25/2014 03:38 pm
I recall that Paul March wrote that the EMDrives tested at NASA Eagleworks had a temperature that never rose more than 1 deg (F ? or C?) above room temperature.

Anybody recall that statement?  Is the temperature measurement in the NASA Eagleworks report? Using search I cannot find it in the text.  Is it in the pictures?

I also recall AcesHigh reporting on information elsewhere reporting March's statement he made on this thread regarding temperature.  Was that at nextbigfuture? Does anybody still have a link for that?

Yes I remember March saying the temperature didn't rise more than 1 degree F. It was F, not C.

Presumably it was the temperature of copper walls ? My guess (pursuing ideas of warm jets) is that <5°C rise in cavity's air would have remained unnoticed. Mass of air<<mass of copper.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 03:40 pm
Ok. That's well thought out. Now can you explain the lack of thrust from the Brady device without dielectric? Remove the dielectric and there is no thrust. What happened to the heat dissipation?

The other problem that continues to arise is the total momentum .vs. the power dissipated

Well March said the temperature of the device didn't increase more than 1 degree F. Seems that those lower power tests <30 watts didn't lend themselves to much heat production. I've commented previously about the value of conducting low power tests, as they allow the experimenter to separate artifact (heat et al) effects from dominant mode effects.) I really think the Chinese tests are flawed because they are dumping large amounts of power into their test device and are claiming eureka off a flawed test protocol. Too much power was used.

Edit:
send became lend
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 03:42 pm
I recall that Paul March wrote that the EMDrives tested at NASA Eagleworks had a temperature that never rose more than 1 deg (F ? or C?) above room temperature.

Anybody recall that statement?  Is the temperature measurement in the NASA Eagleworks report? Using search I cannot find it in the text.  Is it in the pictures?

I also recall AcesHigh reporting on information elsewhere reporting March's statement he made on this thread regarding temperature.  Was that at nextbigfuture? Does anybody still have a link for that?

Yes I remember March saying the temperature didn't rise more than 1 degree F. It was F, not C.

Presumably it was the temperature of copper walls ? My guess (pursuing ideas of warm jets) is that <5°C rise in cavity's air would have remained unnoticed. Mass of air<<mass of copper.

Yes, frobnicat, you are correct.  It is the temperature of the copper walls that Paul March was alluding to.
And I also agree, the air being <5 deg C higher than the copper would not translate into any appreciable increase in temperature of the copper wall in the seconds response measured in the experiments (due to the fact that conduction through air is negligible and convection would rely on very low coefficients of natural air convection).  This is straightforward to show from q/A = h deltaT
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 03:46 pm
.....
I used the Crooke's radiometer as an example.  The rotation of the paddles is not from convection.


Considering Crookes radiometer, eliminates both conduction and convection. 

Crooke's radiometer is contained in a partial vacuum.

None of the tested devices (NASA Eagleworks, Shawyer of Chinese) to my knowledge were tested in a partial vacuum.  To my knowledge Crooke's radiometer does not move under ambient pressure conditions.

Just to be clear, there is air in that partial vacuum. The Crookes Radiometer is not working by radiation pressure. It is working by heat flow. Black surfaces are hotter than white surfaces when exposed to light. I couldn't get my Crooke's Radiometer to move under a 1W green laser. In a complete vacuum, no workie.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/25/2014 03:52 pm
.../...
The big caveat : 4W volumetric heating of (presumably not perfectly dry) air out of 16W microwave power in "empty oven".

The problem: dependence on Q

As I understand it, to heat the air inside the cavity by microwave heating the air needs to have water molecules (it needs to be humid) because the gases in air are non-polar (nitrogen, oxygen, etc.) and hence do not get heated by the microwaves.

But, the more humid the air, the lower the Q.  Hence one would expect an inverse relation between measured force and Q: the higher the Q the smaller the force.

However, statistical examination of all the data (Shawyer and NASA Eagleworks) points in the other direction: the higher the Q the greater the measured force.

Well, I guess none of the experiments gone to the trouble of drying the air inside cavity, and that doesn't prevented them to reach Qs of 45000 (Shawyer b). So if humidity did get to a point where there was enough to catch a big ratio of MW power then yes, more humidity -> less Q. But below that point, say 25% power gets into heating water vapor, that's still 75 losses on the walls, there is room for improvement of walls quality, increasing Q, increasing stored energy levels, making available more power for water vapor heating. Better Q would make stronger jets (higher effective air heating power, higher Tdot)

To asses the matter we would need a model of MW coupling with water vapor diluted at typical atmospheric levels.
Title: Re: EM Drive Developments
Post by: aero on 10/25/2014 03:54 pm
I looked at thrust due to air leaks early on. I discount it just because of the repeatability of the tests across a range of laboratory and thrusters. The inadvertent air leaks are just to consistent across the spectrum of devices for me to consider that as a cause.

And we have Brady's example of "no dielectric, no thrust." Of course removing the dielectric could have uncovered air leaks at the small end to precisely counter the leaks in the large end, I guess. But look at the attached device and test data while considering air leaks.

Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 03:58 pm
...I hope your records are better than mine because I don't have lengths recorded, (or the other dimensions, for that matter.)
The "search" function of this thread is really awful.  Too bad that this thread does not use Google as a search engine

Here's what I do:

Go to google, type in your word or phrase in quotes, include the word emdrive, and type site:nasaspaceflight.com

example:
copy and paste this into google

"dielectric thrust" emdrive site:nasaspaceflight.com

google is a better crawler than the website itself is

Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 04:00 pm
I looked at thrust due to air leaks early on. I discount it just because of the repeatability of the tests across a range of laboratory and thrusters. The inadvertent air leaks are just to consistent across the spectrum of devices for me to consider that as a cause.

And we have Brady's example of "no dielectric, no thrust." Of course removing the dielectric could have uncovered air leaks at the small end to precisely counter the leaks in the large end, I guess. But look at the attached device and test data while considering air leaks.
Need some more help from you in interpreting the information from the image.  Is the point that the bolts in this picture are oriented towards the small end, and presuming that there are no holes exposed on the (unseen) big flat end, and therefore that for this particular device there could not be axial air escaping from the boltholes in the direction of the big end, and that all the air from the big end would have had to escape either radially through the circumferential gap between the flat end and the cone or backwards oriented through the backwards oriented bolts?

==> It would be nice if we could find a front image of the big end on this device, to settle this issue

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=617148;image)
Title: Re: EM Drive Developments
Post by: zen-in on 10/25/2014 04:18 pm
Where was this device tested?  It is very different from the Eagleworks and Shawyer's device.   Is there a picture of it in a test stand and a test report?
Title: Re: EM Drive Developments
Post by: aero on 10/25/2014 04:28 pm
Really, the point is that it is a thruster intended to be flight qualified. It appears to be solidly constructed with gaskets sealing both end plates. Such gaskets would also seal the bolt holes.

A flight qualified device (Nowhere that I can find does it say "space qualified.) would be sealed due to the range of ambient air pressure over the flight regime.

Yes, of course there could be a deliberate hole drilled in the base plate but I can't imagine an accidental hole. And I am not into conspiracy theories between Shawyer, the Chinese, Cannae, and Brady to make hot air thrusters and pawn them off as thrusting from RF wave energy.

We all await the IV&V testing of the new Eagleworks vacuum qualified device. That will either prove or disprove the ion wind and air leak theories.

Add: There is not much more information available about this device. It is one of Shawyer's EM thrusters. Go to emdrive.com and look at the very bottom of the text. There is a link there.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 04:51 pm
Really, the point is that it is a thruster intended to be flight qualified. It appears to be solidly constructed with gaskets sealing both end plates. Such gaskets would also seal the bolt holes.

A flight qualified device (Nowhere that I can find does it say "space qualified.) would be sealed due to the range of ambient air pressure over the flight regime.

Yes, of course there could be a deliberate hole drilled in the base plate but I can't imagine an accidental hole. And I am not into conspiracy theories between Shawyer, the Chinese, Cannae, and Brady to make hot air thrusters and pawn them off as thrusting from RF wave energy.

We all await the IV&V testing of the new Eagleworks vacuum qualified device. That will either prove or disprove the ion wind and air leak theories.

Add: There is not much more information available about this device. It is one of Shawyer's EM thrusters. Go to emdrive.com and look at the very bottom of the text. There is a link there.

By << no holes exposed on the (unseen) big flat end>> I meant the holes through which the visible bolts where threaded through.  Of course it goes without saying that I also agree that << conspiracy theories between Shawyer, the Chinese, Cannae, and Brady to make hot air thrusters and pawn them off as thrusting from RF wave energy>>.

I see bolts that are used to fix the base plate to the cone, those bolts may be threaded into threaded holes on the base plate. 

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=617151;image)

My question was whether the threaded holes on the base plate were blind drilled or whether they were drilled all the way through.  If they were drilled all the way through, it is possible that pressurized air would escape between the holes and the bolts without the researchers being aware of it.  No conspiracy theories or evil intentions are needed and of course they were never intended. I was just objectively giving fair review to frobnicat's theory and analysis

==> As I wrote, It would be nice if we could find a front image of the big end on this device, to settle this issue, as it would reveal whether the threaded holes were blind drilled (hence not visible from the front and hence no air jets) or whether they were drilled all the way through (hence visible and hence able to have air jets escape through them like axial nozzles)
Title: Re: EM Drive Developments
Post by: aero on 10/25/2014 05:06 pm
Something we've been overlooking is the age of the devices we have been considering from Shawyer. His demonstrator EM thruster program leading to the device that we are looking at was started in 2003, 11 years ago. He has national government money and private investor money to forward his research. I don't know the date that the flight thruster test program was completed, but I do know that in 2010 he published a photo of his follow-on device, a superconducting EM thruster, photo attached. That was 4 years ago.

There is just to much money being spent on these devices for the test results to be bogus or caused by some bogus effect and not be detected. And if such bogus effect was detected then 4 years is just to long to keep it a secret, it would leak to the news and make a big splash in the headlines. JMO
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 05:07 pm
...could this be the culprit behind the EM Drive?...

I'm not a Scot, so I cannae work on that druve,

Thank you sir.  :D
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 05:13 pm
First attempt to model thrust from cavity's air volumetric heating and jet effect through small aperture. Case studied : Brady a.

Model needs refining (please be patient) but first rough estimates put in the ballpark of 100µN effect during 30s with fast rise of 2s. For now I will give numerical values and derive feasibility from them, in reverse from the set of general equations from which those values derive because I'm still struggling to put some order with all parameters and dependences. Also I want a clean differential equation, takes some time.

Needed hypothesis : air inside cavity is volumetrically heated at Pow=4W (that is, air gets around 25% of microwave power input). There are hole(s) or crevice(s) between cavity and exterior of device, in the direction of thrust (air jetting...) for a total area of A=1.6 mm².

Mind you, volumetric air heating Pow=4W and hole area A=1.6mm² are unknowns, so these values were carefully chosen to get to some magnitude to explain... not the other way around.

Temperatures around 20°C  T = 293K
Cavity volume V = 0.027 m^3
Initial mass of air m = rho*V = 1.2 * .027 = .0324 kg (32 grams of air)
Assuming some air will be leaving but only a small part of that, so not significantly alter the heat capacity of the whole. Heat capacity supposed constant.

We put 4W of power into that, with a specific heat of  C=1000J/kg/K  Tdot = Pow / ( C * m ) = 0.123 K/s

Consider first a short transient period with pressure buildup (like the hole is closed), m constant, p*V=m*Rs*T (Rs around 287 J/kg/K for air)
pdot = m*Rs/V *Tdot = 42 Pa/s  (Pascals per second, please remember there is 10^5 Pa in one atm. pressure). So in 2s we would reach 84 Pa more pressure inside vessel than outside. Note that Tdot uses an isobar value of C (1000) while strictly in this phase we would be in isochore conditions (C=720) : that would only lower the time. So in less than 2 seconds 84 Pa differential. Pd = 84 Pa.

This is the transient. At this level of pressure differential the rate of air escaping through the hole becomes important enough that this pressure will be kept constant while the temperature continues to rise (why I choose isobar heat capacity overall) :
The mass flow through aperture mdot = Cf A sqrt(2 rho Pd) where Cf is a flow coefficient depending on geometry and I understand is around 0.6 for rough holes.
This is from orifice plate article on wikipedia (http://en.wikipedia.org/wiki/Orifice_plate) (repress any second thought here), I took the most simplified forms assuming incompressible flow (pressure differential / absolute pressure < 1/1000 so I guess this is a good first approximation). On this chapter (http://en.wikipedia.org/wiki/Orifice_plate#Incompressible_flow), equation (2).

=> mdot = 1.36 10^-5 kg/s  of air expelled through the 1.6 mm² hole(s).
This is a volume flow of mdot/rho = 1.13 10^-5 m^3/s
Speed of ejection is volume flow divided by hole section : v = 7.1 m/s
Clearly not sonic or supersonic.

The reaction force imparted (thrust) = mdot * v = 9.65 10^-5
Thrust = 96 µN

Reported by Brady a : 91.2 µN

After 30 seconds of this "steady state" of constant rate of heating and expelling air :
T would be 3.7 ° above initial conditions
Mass of air expelled 0.41 g (a bit more than 1% of initial air mass of 32g)

Sanity check on total momentum :
From momentum expelled by jet : 0.41e-3 kg * 7.1 m/s = 2.9e-3 kg m/s
From required thrust during 30s : 96e-6 N * 30 s = 2.9e-3 kg m/s

When power off, Tdot falls to 0, sharp fall to 0 thrust ( differential pressure is quickly released, pressure equilibrium restored with same time constant as rise time < 2s). Conduction slowly release the heat of gas through the (colder) copper walls with a long time constant. No visible effect of contracting gas sucking air through the hole(s) when restoring T equilibrium.

Thank you for your patience.

I have nothing but the utmost respect for you for providing that analysis. I really wish I could give the same treatment for the non-radiative inductive effects I'm chasing after. I really feel like a Faraday without Maxwell.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 05:17 pm
Having said that, aero makes very good points concerning <<A flight qualified device (Nowhere that I can find does it say "space qualified.) would be sealed due to the range of ambient air pressure over the flight regime.>>

and that <<the point is that it is a thruster intended to be flight qualified. It appears to be solidly constructed with gaskets sealing both end plates. Such gaskets would also seal the bolt holes. >>

yes, if the gasket is compliant enough under stress produced by the torqued bolts, it should seal the whole perimeter.  The only other escape would be between the threaded bolts and the threaded holes (if threads were used) which are of course not gasketed.  Then frobnicat would need to posit A) a means for air to make it to the boltholes and to have air still be able to escape between the threaded holes and the bolts, B) holes drilled all the way through, and  C) very rough surfaces on the bolt and hole threads, and  the gaps would be extremely small.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 05:18 pm
Having said that, aero makes very good points concerning <<A flight qualified device (Nowhere that I can find does it say "space qualified.) would be sealed due to the range of ambient air pressure over the flight regime.>>

and that <<the point is that it is a thruster intended to be flight qualified. It appears to be solidly constructed with gaskets sealing both end plates. Such gaskets would also seal the bolt holes. >>

yes, if the gasket is compliant enough under stress produced by the torqued bolts, it should seal the whole perimeter.  The only other escape would be between the threaded bolts and the threaded holes (if threads were used) which are of course not gasketed.  Then frobnicat would need to posit a means for air to make it to the boltholes and to have air still be able to escape between the threaded holes and the bolts (this would require very rough surfaces on the bolt and hole threads, and the gaps would be extremely small).

RTV.........to seal bolt holes, no biggie. But as soon as you introduce a gasket, the resonant cavity is no more. A resonant cavity isn't just mechanically enclosed; it is electrically enclosed. A short in all directions. As we say, a short is a short....loosely related to another saying frequently used, ground is ground.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 05:30 pm
Can the polymer gasket between the base plate and the cone act as a dielectric barrier discharge (DBD) actuator? 
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 05:38 pm
Something we've been overlooking is the age of the devices we have been considering from Shawyer. His demonstrator EM thruster program leading to the device that we are looking at was started in 2003, 11 years ago. He has national government money and private investor money to forward his research. I don't know the date that the flight thruster test program was completed, but I do know that in 2010 he published a photo of his follow-on device, a superconducting EM thruster, photo attached. That was 4 years ago.

There is just to much money being spent on these devices for the test results to be bogus or caused by some bogus effect and not be detected. And if such bogus effect was detected then 4 years is just to long to keep it a secret, it would leak to the news and make a big splash in the headlines. JMO

Yeah I know. I'm hearing you loud and clear too!; but I have questions too. The first one is why wouldn't Guido Fetta have given Nasa his better performing superconducting cannae device (same for Shawyer)? I don't think it actually exists outside of paper. The dates on the photos in the Nasa conference paper are Jan 2014.

Also the latest paper by Shawyer contains no actual data, it is just another quick and dirty powerpoint type of presentation designed to stir hearts and minds. I smell a rat in all this. This all ties into why I give much more credence to the Nasa conference paper than other sources. The Nasa papers have no conflict of interest. Shawyer is trying to sell me a cow, but where's the beef!??!
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 05:47 pm
Can the polymer gasket between the base plate and the cone act as a dielectric barrier discharge (DBD) actuator?

I investigated these too. They are a neat way to get rid of flaps and ailerons. I like where you're going with this, but I can't see how this technology applies to emdrive's anomalous thrust because of the penetrating bolt through the whole assembly of the test device, which are conductive. I dismissed them because of this. Another possible interaction in my search for ways rf on the inside, influences the world on the outside.

Electrical and magnetic evanescent fields finally won out in my view.
Title: Re: EM Drive Developments
Post by: aero on 10/25/2014 06:16 pm
Quote
Also the latest paper by Shawyer contains no actual data, it is just another quick and dirty powerpoint type of presentation designed to stir hearts and minds. I smell a rat in all this. This all ties into why I give much more credence to the Nasa conference paper than other sources. The Nasa papers have no conflict of interest. Shawyer is trying to sell me a cow, but where's the beef!??!] Also the latest paper by Shawyer contains no actual data, it is just another quick and dirty powerpoint type of presentation designed to stir hearts and minds. I smell a rat in all this. This all ties into why I give much more credence to the Nasa conference paper than other sources. The Nasa papers have no conflict of interest. Shawyer is trying to sell me a cow, but where's the beef!??!

It is true that Shawyer had reduced or eliminated the publication of test results for his different devices.

It would be good to have actual test data from his superconducting demonstration thruster (see photo above). It is pretty clear that with the thruster in a liquid nitrogen (or whatever) bath there won't be air leaks or other spurious aero forces. So - where is the data? Just one test run, that's all I ask.
Title: Re: EM Drive Developments
Post by: Supergravity on 10/25/2014 06:45 pm
What's shocking to me is how this thread made it even past page 2. This is so clearly in violation of known physical laws and it has to be that these experimenters botched the entire thing, failing to take precautions that an undergraduate would be mindful of.

How about we spend all of this energy on more productive and realizable technologies, not fantasy devices that are so clearly in breach of conservation laws and require silly hokum such as "quantum vacuum plasma" and a terrible experiment procedure to even be somewhat plausible?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 06:52 pm
@MikeMcCulloch

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-motion-from-logic.html

I think Spock would say, "Proper context and perspective are paramount Doctor......"

After all, we're accelerating 9.8m/s2. Not huge accelerations required for special relativistic effects, and not micro accelerations which are the domain of MiHsC.

From P.F.T.E., linked to above, "Now imagine Spock fires a back pack rocket motor and accelerates forward."

There's no rocket backpacks on the test bench.

Sir your theory is indeed revolutionary, IMHO of course, but let's not paint with so wide a brush stroke.

Your theory does indeed fit into the framework of this silly copper can's anomalous thrust, but not by virtue of teaching light new tricks.

Your theory appears sound, but it must be applied in the most logically salient direction, in the proper context.

Given the core tenets of MiHsC, does this theory really predict any useful effect here on the Earth's surface, where we are dominated by relatively strong interactions, compared to tiny Casimir interactions which are only measurable at extremely tiny scales?

I saw relatively quickly how MiHsC applied to EMdrive, but the practical effect is essentially zero when applied to a copper cone here on Earth.

I ask you sir, "Where are the lowest accelerations possible, with respect to a reference frame, within the bounds of MiHsC?"

Do the walls of the cavity define such a reference frame?

Where is the demarcation point along a wire/waveguide leading from the signal generator to the emdrive RF connector? Where does one reference frame end/begin?

Is it possible that there is no line of demarcation? I see there is absolutely no such line.

Instead we must go back to Feynman, who said all mass is interaction. This interaction (from all scales) defines your reference frame, which is defined isotropically. In areas where interactions are small but not zero (uncertain), such as the low accelerations you may see at the edges of galaxies, this interaction becomes an uncertain value.

This is the heart of MiHhC.

You are in a very good position to achieve a second look, but be careful to not over extend.

Others may throw the baby out with the dirty bath water.....Trying to discredit you in favor of old paradigms. How many years will that cost?

Thank you Doctor.

Please educate me/us.

Edited, added more questions.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/25/2014 06:52 pm
There is just to much money being spent on these devices for the test results to be bogus or caused by some bogus effect and not be detected.
I would argue the opposite.  With this kind of money spent, why has the science not been settled and why is there no reliable technology that everyone can agree on?  I think this is all wishful thinking.  Certainly Shawyer's explanation for how the thing should produce thrust is completely wrong, and he's had 11 years to make it right.  How is it he is still championing this mishandling of the "group velocity" concept?  Clearly demonstrates he's off in pathological science land--I would not trust anything one hears from someone so committed to reasoning he knows must be flawed.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 06:59 pm
There is just to much money being spent on these devices for the test results to be bogus or caused by some bogus effect and not be detected.
I would argue the opposite.  With this kind of money spent, why has the science not been settled and why is there no reliable technology that everyone can agree on?  I think this is all wishful thinking.  Certainly Shawyer's explanation for how the thing should produce thrust is completely wrong, and he's had 11 years to make it right.  How is it he is still championing this mishandling of the "group velocity" concept?  Clearly demonstrates he's off in pathological science land--I would not trust anything one hears from someone so committed to reasoning he knows must be flawed.

Yes you are absolutey right on all counts and welcome back. Shawyer in my view is a good engineer and a great public relations engineer, but he left his skeptic and scientific method hats at home.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 07:02 pm
Seriously guys, this evanescent field junk I'm going on about isn't pseudoscience bs. It is a real method by which internal RF dynamics directly influence the outside of a waveguide/cavity. A perfectly designed resonator can give rise to leaky modes. It is pure science. Not even a tiny leap.

This can put the bs to bed and bring order back to EMdrive. Just takes work. Not magic. And many heads.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/25/2014 07:23 pm
What's shocking to me is how this thread made it even past page 2. This is so clearly in violation of known physical laws and it has to be that these experimenters botched the entire thing, failing to take precautions that an undergraduate would be mindful of.

How about we spend all of this energy on more productive and realizable technologies, not fantasy devices that are so clearly in breach of conservation laws and require silly hokum such as "quantum vacuum plasma" and a terrible experiment procedure to even be somewhat plausible?

I think it is clear the experimentalists (at Nasa at least) are professionals. I'm not going to sell these men and women short. Eagleworks has been at it for several years and they have lessons learned under their belt before the EMdrive test campaigns. (not conjecture, look for yourself) At the very least they have personal and organizational reputations to protect.....and they work for a NASA. I have no reason not to respect NASA. Even with the screw ups over the years at NASA, the AARs have been completely pitch perfect on par scientific and analytical......eg. No bs.

I can tell you that it is not acceptable to release a conference paper without following up (they have to know this) with an actual study asap. They concluded the conference paper with a way forward to more studies.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 07:24 pm
As I understand it, to heat the air inside the cavity by microwave heating the air needs to have water molecules (it needs to be humid) because the gases in air are non-polar (nitrogen, oxygen, etc.) and hence do not get heated by the microwaves.

I don't recall that ambient humidity was mentioned in any of the experimental protocols.

This OSHA document recommends a relative humidity of 30% to 60% on p7:

Quote from: OSHA
Check whether the temperature and humidity are maintained in a recommended comfort range (temperature: 68 to 78 degrees and relative humidity: 30% to 60%)

If the lab followed these recommendations, then there should be a certain amount of moisture in the ambient air of the cavity.

As to whether the "warm jets" are coming out of the seam or boltholes, good luck modeling where all those random directions and random holes are! 

Whatever that M/W effect is on the water vapor in the cavity, it can't amount to much, but I guess it points again to the desireability of testing in vacuum.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 07:26 pm
I really feel like a Faraday without Maxwell.

I hate it when that happens.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 07:30 pm
It is true that Shawyer had reduced or eliminated the publication of test results for his different devices.

And how does that tie in with credibility?
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 07:31 pm
As I understand it, to heat the air inside the cavity by microwave heating the air needs to have water molecules (it needs to be humid) because the gases in air are non-polar (nitrogen, oxygen, etc.) and hence do not get heated by the microwaves.

I don't recall that ambient humidity was mentioned in any of the experimental protocols.

This OSHA document recommends a relative humidity of 30% to 60% on p7:

Quote from: OSHA
Check whether the temperature and humidity are maintained in a recommended comfort range (temperature: 68 to 78 degrees and relative humidity: 30% to 60%)

If the lab followed these recommendations, then there should be a certain amount of moisture in the ambient air of the cavity.

As to whether the "warm jets" are coming out of the seam or boltholes, good luck modeling where all those random directions and random holes are! 

Whatever that M/W effect is on the water vapor in the cavity, it can't amount to much, but I guess it points again to the desireability of testing in vacuum.

Testing rapidly in an ambient vacuum without waiting until the cavity itself is free of air would not be enough.

The air that needs to be humid is the one inside the cavity.  Hence before the test is conducted the researchers must make sure that the medium inside the cavity itself is at a vacuum.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 07:36 pm
What's shocking to me is how this thread made it even past page 2. This is so clearly in violation of known physical laws and it has to be that these experimenters botched the entire thing, failing to take precautions that an undergraduate would be mindful of.

How about we spend all of this energy on more productive and realizable technologies, not fantasy devices that are so clearly in breach of conservation laws and require silly hokum such as "quantum vacuum plasma" and a terrible experiment procedure to even be somewhat plausible?

WEll, I gotta say, I'm learning a lot about people, am getting practice in scientific rhetoric, and learning somewhat less math than French, but hey.

Best I can tell, is that the mhe math whiz bangs here think that something could be happening, and are snapping their synapses over just what could be happening that is consistent with the reported results.

Although I'm with you on the sloppy experimental protocols, even by amateur standards.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 07:44 pm
Assessment of Shawyer's and McCulloch's formulas for EM Drive experimental thrust


From the comparison with experimental results in  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1276053#msg1276053
the formulas from Shawyer and McCulloch are close to each other for the range of geometries, power input, Q and frequencies explored during the measurements.  The following big difference can be pointed out:

A) McCulloch's formula blows up for the ratio of smallDiameter/cavityLength -> 0 (approaching zero).

B) Shawyer's formula blows up much sooner, due to his introduction of the "Correction Factor" due to group velocity (see Eq.8 p.4 of http://www.emdrive.com/IAC-08-C4-4-7.pdf ).  It is obvious that this correction factor goes to infinity as the free-space wavelength becomes equal to the Geometric Average of the diameters of the big and small bases of the truncated cone.  Shawyer's formula goes to infinity for

(free-space wavelength) --> GeometricAverage[bigDiameter,smallDiameter] or

(free-space wavelength) --> Sqrt[bigDiameter*smallDiameter]

or, equivalently:

smallDiameter/bigDiameter --> (RFwavelength/bigDiameter)^2 / (1+(RFwavelength/(2*cavityLength))^2)

or, equivalently for:

smallDiameter/bigDiameter --> (c/(bigDiameter*RFfrequency))^2 / (1+(c/(2*cavityLength* RFfrequency))^2)




As a numerical example, for Shawyer's experimental drive with

(* Shawyer Experimental *)
rfFrequency=2.45*10^9;
cavityLength=0.156;
bigDiameter=0.16;
smallDiameter=0.11;
designFactor= 1.23205
power =  850   
Q = 5900

measured force = 16
ShawyerForce = 41 (2.56)
McCullochForce = 7  (0.438)



Shawyer's formula blows up (it goes to infinity), for these values, when the small diameter is about 1/2 the big diameter

smallDiameter/bigDiameter = 0.506912

Or, in this case for smallDiameter = 0.081 m

This is the reason why Shawyer's formula gives such a large predicted value (6 times greater than McCulloch's formula) for this case, as of all the experiments we have reviewed (UK and USA) Shawyer's demo drive is the one that has the smallest smallDiameter (just 35% bigger than the dimension for which Shawyer's formula gives an infinite force).
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 07:44 pm
Testing rapidly in an ambient vacuum without waiting until the cavity itself is free of air would not be enough.

The air that needs to be humid is the one inside the cavity.  Hence before the test is conducted the researchers must make sure that the medium inside the cavity itself is at a vacuum.

Oh I get that.

But they are not testing in ambient vacuum.  They are testing in ambient indoor air of comfortable quality, between 30% and 60% humidity, air which is inside the cavity.

So if Frobnicat wants to model warm jet leakage, I think there should be enough water vapor in the cavity to warm up to some extent.  Enough to leak?  IDK, ask Frob.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 07:48 pm
Also, can somebody tell me how you get momentum out of group velocity?

'Cuz I thought there was no relationship whatsoever between the two.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 07:57 pm
Shawyer's introduction of group velocity leads to his predicted force going to infinity as (   http://forum.nasaspaceflight.com/index.php?topic=29276.msg1276505#msg1276505  )

free-space wavelength = GeometricAverage[bigDiameter,smallDiameter]

For Shawyer's demo drive experiment this effectively means that the output force becomes infinite when the small diameter becomes about 50% of the big diameter (given the other parameters in his demo drive). 

If he wants to maximize the force and believes that "group velocity correction" to be correct, why didn't he then make the small diameter that size to maximize the force?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 08:02 pm
I dunno.   'Coz he doesn't want to make it too easy? 

Stuff like this is bothersome and worse than annoying.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 08:05 pm
I dunno.   'Coz he doesn't want to make it too easy? 

Stuff like this is bothersome and worse than annoying.

Well Shawyer gave us his equations to predict force and he may have other constraints.

I have not found the actual equation that Dr. White at NASA uses to predict forces

I have seen Dr. White's derivation for the electron mass, Bohr radius, gravitational coupling constant, his MHD plasma analogy, and Microsoft Excel spreadsheet predictions (see attached).  But I don't know what actual equations he used in that Microsoft Excel spreadsheet to make the prediction.

Can anyone please provide Dr. White's equation to predict the thrust force from his electron-positron virtual particle quantum vacuum theory?

Seriously, we have numerical comparisons of Shawyer's and McCulloch's predictions with experiments (see :  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1276053#msg1276053   ).

Some people have even spent time writing a Wikipedia article on "Quantum Vacuum Plasma Thruster" http://en.wikipedia.org/wiki/Quantum_vacuum_plasma_thruster but have failed to provide an equation to calculate the thrust force from such a "Quantum Vacuum Plasma Thruster."

This is an appeal to also include Dr. White's quantum-vacuum-plasma thrust-force-prediction equations.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 08:35 pm
Also, can somebody tell me how you get momentum out of group velocity?

'Cuz I thought there was no relationship whatsoever between the two.

Yes certainly, that is easy to show.   For example,  for a free, non-relativistic quantum mechanical particle of mass m and wavenumber k, for which we have E = (hk)^2/(2m) and angular frequency omega = h k^2/(2m) (hence we have quadratic dispersion in this case).   We can calculate the group velocity (as the partial derivative of the angular frequency with respect to k) for this dispersion as vg=hk/m and this is perfectly consistent with the movement of a semiclassical particle for which the momentum is p = hk and the group velocity thus p/m = vg, or:

momentum = groupveloctiy * mass

Notice that for this case the phase velocity (omega/k) is hk/(2m) which is 1/2 of the group velocity, and hence it is the phase velocity the one that is not directly related (by mass) to the momentum.



Also, it is obvious that for the case in which a linear dispersion would apply the group velocity and the phase velocity would be identical. For example, for light in vacuum, phase and group velocity (for plane waves) are identical due to the linear dispersion  omega = k * c, obviously.



Before anyone jumps the gun: look at the careful words and equations I chose, and please don't use Wikipedia as a reference to argue the above points.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/25/2014 09:19 pm
Next you can mention that photons don't have a linear dispersion in a waveguide w/ one exception.
Title: Re: EM Drive Developments
Post by: Supergravity on 10/25/2014 09:40 pm
I think it is clear the experimentalists (at Nasa at least) are professionals. I'm not going to sell these men and women short. Eagleworks has been at it for several years and they have lessons learned under their belt before the EMdrive test campaigns. (not conjecture, look for yourself) At the very least they have personal and organizational reputations to protect.....and they work for a NASA. I have no reason not to respect NASA. Even with the screw ups over the years at NASA, the AARs have been completely pitch perfect on par scientific and analytical......eg. No bs.

I can tell you that it is not acceptable to release a conference paper without following up (they have to know this) with an actual study asap. They concluded the conference paper with a way forward to more studies.

Eagleworks, why does that name sound familiar? Oh, you mean the guys who've been researching outlandish concepts like warp drives (http://sploid.gizmodo.com/holy-crap-nasas-interplanetary-spaceship-concept-is-fr-1589001939), believing it is actually a viable technology? I'm sorry if I'm just a tad bit skeptical of the claims of this group.

Just ask yourself this, if this group really did possibly stumble upon something, why is the engineering community (as whole) ignoring it, let alone the physics community? If this actually works in the way White et al. say it does, then they have stumbled upon a device that cannot be explained fundamentally by the standard model of particle physics. That may sound trivial, but it would be a complete disaster to many physicists.

If these scientists simply went to the scientific and engineering community and said, "look, we have these results, they appear to be inconsistent with everything we know about how the universe works and we'd like to know where we're going wrong", you'd see a lot more scientists and engineers look into it, just like the whole debacle with CERN and the superluminal neutrinos. They didn't invoke some fanciful string-theory explanations on their path-lengths being shortended via extra-dimensions (although some desperate theorists tried to push it), but they acted like how you'd expect professional scientists would when finding such controversial results.
Title: Re: EM Drive Developments
Post by: Supergravity on 10/25/2014 10:18 pm

WEll, I gotta say, I'm learning a lot about people, am getting practice in scientific rhetoric, and learning somewhat less math than French, but hey.

Best I can tell, is that the mhe math whiz bangs here think that something could be happening, and are snapping their synapses over just what could be happening that is consistent with the reported results.

Although I'm with you on the sloppy experimental protocols, even by amateur standards.

I guess it's all relative, then. While I'm sure the people here are no less brilliant when it comes to matters of applied science and technologies, they really are (for the most part) clueless when it comes to matters of fundamental physics and advanced mathematics from what I've seen. Just skimming this thread confirms my suspicion. Mostly algebraic manipulations of rather simple Newtonian equations and some differential calculus sprinkled in, nothing you wouldn't see in a first year math class. Where are the action principles? Or how about the symmetry arguments that would then trivially lead to the conservation laws via Noether's theorem? And for those pushing the quantum vacuum plasma "model", what is the form of the quantum fields (and these have to be there) in your model? Where are the path-integrals that should explain the interactions of those fields? I would be more impressed by such a model even if its path integrals diverged. I don't even see math that is appropriate for quantum mechanics in the low-energy limit, such as density functional theory, fourier transforms, abstract linear algebra, etc.



If you want to learn physics, I strongly recommend not learning based on the speculations of bored engineers. When it comes to everything else on this forum, these are generally the perfect people to learn from. But with these fringe topics, I humbly believe you're better off building your physical intuition from the classic textbooks so then you would at least be armed with the correct intuition to sift between the speculatively plausible and the outright nonsensical.
Title: Re: EM Drive Developments
Post by: Supergravity on 10/25/2014 10:29 pm


Supergravity, what is your opinion of the Woodward effect ? ( see

http://www.amazon.com/Making-Starships-Stargates-Interstellar-Exploration/dp/1461456223/ref=sr_1_1?ie=UTF8&qid=1414273515&sr=8-1&keywords=james+woodward+wormholes   and

http://physics.fullerton.edu/component/zoo/item/dr-james-f-woodward  and

http://physics.fullerton.edu/~jimw/)

(since you are discussing the topic of
researching outlandish concepts like warp drives
)

You can see my opinion here in the actual  Woodward thread (http://forum.nasaspaceflight.com/index.php?topic=31037.330), and if you're interested, my back and forth exchange with 93143 on the physical plausibility of the Woodward effect.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/25/2014 11:21 pm
I say be patient, showing some numbers specifically for "Brady a" and how a very specific combination of leak area and direction and volumetric air heating power can, to my surprise, reach reported result, this is a first shot. Before embarking onto Shawyer's devices leaks (BTW can someone answer to this apparently simple question : has superconducting EMdrive been tested yes or no ? Yes if I'm to interpret the rightmost big red dot page 2 of latest Shawyer presentation (http://www.emdrive.com/iac2014presentation.pdf), but really ?) let's see more equations will you ?

It's awful to derive equations inside posts, just the results (basically from pV = nRT and orifice plate mass flows (http://en.wikipedia.org/wiki/Orifice_plate#Incompressible_flow)) are :

Where relatively constants are
> T=293K (20°C) average temperature
> C=1000 J/kg/K isobar specific heat of air (http://en.wikipedia.org/wiki/Heat_capacity#Table_of_specific_heat_capacities) (more like 1012)
> rho=1.2 kg/m^3 air density (http://en.wikipedia.org/wiki/Density_of_air#Temperature_and_pressure)
> p=1e5 Pa absolute pressure (more like 1013, depending altitude and weather)
> Cf=0.6 dimensionless Coefficient of discharge (http://en.wikipedia.org/wiki/Orifice_plate#Computation) I put at 0.6 for a "sharp-edged orifice" but could be 0.8 if smoother...

Fixed in the case of Brady a
> V=27e-3 m^3  (27 litres) volume of cavity

Things to explain
> F=100µN (about, reported result 91.2 µN)
> Tau=2s (really uncertain, typical rise time, could be much lower)

Unknowns
> Pow=?W  power effectively heating air inside cavity (must check less than total power 16.9W)
> A=?m^2 area of leaks

Going from Unknown to things to explain gives
(1) F = 1/( A*rho) ( Pow / (C*T) )^2
(2) Tau = V*Pow / (2*C*T*Cf^2*A^2*p)

If replacing relatively constant values :
(1') F = 9.7e-12 * Pow^2/A
(2') Tau = 4.74e-11 * V*Pow/A^2

The other way around yields something not nice
(3) Pow = C T ( (rho^2*V*F^2)/(2*Cf^2*p*Tau) )^(1/3)
(4) A = ( (rho*V^2*F)/(4*Cf^4*p^2*Tau^2 )^(1/3)

If replacing relatively constant values :
(3') Pow = 7950 * ( V*F^2/Tau )^(1/3)
(4') A = 6.14e-4 * ( V^2*F/Tau^2 )^(1/3)

Ok so now we see from (1) and (1') that, A being fixed (surely the experimenter don't track it actively) that force should rise to the (air absorbed) power squared. Surely the amount of power absorbed volumetrically would be linear to the total microwave power (?), so this effect would expect a force quadratic in the microwave power. This is apparently not the case for Shawyer's scatterplot (cited here by Aero (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1276394#msg1276394)).

I could have made some blunder, I double checked only twice. I think equation (1) is correct. To my surprise Volume is not involved. The Force goes to infinity when A goes to 0 (smaller and smaller hole) because it means pressure differential can get higher when pressure equilibrium occurs. A maximum tau of 2s limit this divergence : you can only get to those higher pressures by waiting for too long (with too small a leak).
edit: also too small a hole gives higher ejection velocities, at some points the flow goes sonic and the formulas used are no longer valid. The range of validity is respected as velocities are below 10m/s for 1mm² leaks or so.

Also instead of a smooth transition from isochore initial heating (transient) to isobare (almost steady state, pressure at equilibrium with heating rate) I considered the two phases separately, the second to derive F, and the first to derive Tau to get to that "steady state".

Has any of those thrusters ever thrusted for a loooong time ? I mean, more than 30 minutes ?
That also would be a strong argument against this warm air leak hypothesis (after too long there is thermal equilibrium, no more Tdot, no more gas dilation to sustain a jet, thrust would go to 0).

edit: oh yes and I use isobar specific heat capacity to derive Tau, when the start of the transient would be more isochore (divide specific heat by 1.4). That would give shorter Tau. But real transition would be smoother (a bit longer, asymptotically reaching the plateau of thrust). So take all that, how do you say, with a grain of salt ? I believe I'm within a factor 2 of more precise values, perhaps 1.5

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/25/2014 11:30 pm
Quote
Si vous voulez apprendre la physique, je recommande fortement de ne pas l'apprentissage basé sur les spéculations des ingénieurs ennuyer.

Eh bien. Pourquoi pas? Il est plus que un peu amusant, un apprentissage adéquat pour synapses congelés, et propose une thérapeutique de valeur affecte ainsi; que d'une redirection délibérée de l'obsession.

Dans l'ensemble, pas une mauvaise Ting.
Title: Re: EM Drive Developments
Post by: Rodal on 10/25/2014 11:44 pm
... Before embarking onto Shawyer's devices leaks (BTW can someone answer to this apparently simple question : has superconducting EMdrive been tested yes or no ? ...
There is this about Cannae's superconducting test

http://web.archive.org/web/20121102082714/http://www.cannae.com/proof-of-concept/experimental-results

Quote
On January 13, 2011, Figure 1 was generated by sending 10.5 watt power pulses of 1047.335 MHz RF phase-locked power forward to the POC resonating cavity located in the experimental apparatus. The POC cavity is operated in the TM010 mode. Figure 1 shows 6 dips in the compressive force on the load cells. These 6 dips in the load-cell outputs coincide with the 10.5 watt power pulses sent into the cavity from the signal-generation circuit. Figure 1 also shows 2 positive peaks in the voltage signal coming from the load cells. These positive peaks resulted from placing a 2-gram calibrated weight onto the support arm that supports the POC cavity and vacuum tubing. Figure 1 was generated 65 minutes after bringing the pressure over the liquid helium bath up to atmospheric pressure from a pump-down pressure of 50 Torre. The 6 dips in voltage in Figure 1 correspond to a reduction in compressive force on the load cells of 8-10 mN.

The upward drift of the load-cell voltage output of Figure 1 occurred with and without power being sent to the POC cavity. Moisture condensation on the cold equipment and signal drift (within specifications) of the load cells, contributed to the drift of the voltage output. The frequency of the drift in load-cell output is much lower than the frequency of the power pulses sent into the cavity and the calibration pulses.  The dips in load-cell voltage output during power-pulse cycles is clearly visible against the background signal drift.

(http://web.archive.org/web/20121102082714im_/http://www.cannae.com/images/test_run2.gif)
Title: Re: EM Drive Developments
Post by: frobnicat on 10/26/2014 12:09 am
... Before embarking onto Shawyer's devices leaks (BTW can someone answer to this apparently simple question : has superconducting EMdrive been tested yes or no ? ...
There is this about Cannae's superconducting test

http://web.archive.org/web/20121102082714/http://www.cannae.com/proof-of-concept/experimental-results

Ok, thanks. Amazing this is to be excavated from the grave of the web.

You realised it was not really "during 2 minutes", but repeated "pulses" of unknown duration  ::)
On top of a drifting baseline ...
"The upward drift of the load-cell voltage output of Figure 1 occurred with and without power being sent to the POC cavity."
All right then, live with it.
"The dips in load-cell voltage output during power-pulse cycles is clearly visible against the background signal drift." Yeah, sure, something is going up and down. And we certify this is going more up than down.

Sigh. I'm starting to give up not to share the damning of Supergravity on the subject.
( je commence à renoncer à ne pas partager le constat accablant de Supergravity sur le sujet )
Title: Re: EM Drive Developments
Post by: frobnicat on 10/26/2014 12:14 am
This is what we have to work with

Do we have to ?
Should we ?
Can we?
Oui ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 12:17 am
This is what we have to work with

Do we have to ?
Should we ?
Can we?
Oui ?

Well, in a manner of speaking  8)

https://www.youtube.com/watch?v=-uZlvKXnYU4
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 01:34 am
Can the polymer gasket between the base plate and the cone act as a dielectric barrier discharge (DBD) actuator?

 I like where you're going with this, but I can't see how this ...applies ... because of the penetrating bolt through the whole assembly of the test device, which are conductive. I dismissed them because of this. ..

How can we possibly know the electrical conductivity of the bolts they used to attach the base plates to the copper cone?  Is there information about the type of bolts that were used ?

And the bolts are not going through the copper cone but they thread through to flanges.  How are the flanges themselves made and/or attached to the cone?
Title: Re: EM Drive Developments
Post by: aero on 10/26/2014 01:50 am
Can the polymer gasket between the base plate and the cone act as a dielectric barrier discharge (DBD) actuator?

 I like where you're going with this, but I can't see how this ...applies ... because of the penetrating bolt through the whole assembly of the test device, which are conductive. I dismissed them because of this. ..

How can we possibly know the electrical conductivity of the bolts they used to attach the base plates to the copper cone?  Is there information about the type of bolts that were used ?

And the bolts are not going through the copper cone but they thread through to flanges.  How are the flanges themselves made and/or attached to the cone?
Sorry, This is not in response to your post, but rather to the top photo you attached.

From the first photo that you attached, it looks to me like the horizontal 1 1/2 inch beam on the far side of the thruster, and the end of the lower 1 1/2 inch beam on the near side of the thruster are just about equidistant from the center of the base plate of the thruster. Measuring distance perpendicular to the axis of the cone, that is. Setting our reference length to the average measured 1 1/2 inches should give a better reference than using one or the other.
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 01:50 am
....
> Tau=2s (really uncertain, typical rise time, could be much lower)
....
I modeled the nonlinear coupled equations of motion (obtained from solving the Lagrangian) of the inverted torsional pendulum with Mathematica.

The 2 seconds rise is purely due to the inertial response of the equations of motion to an impulsive rectangular pulse.   There is no doubt about it.  It is due purely to the mass, damping and stiffness matrices of the pendulum.  The 2 sec rise is not due to a time-dependent-loading that takes 2 sec to reach full load.

So what one needs to find is an experimental artifact that acts like an instantaneous  (within the time scale), impulsive pulse.  Not one that takes 2 sec to reach full load.  If the loading function itself would take 2 seconds to reach full load, the response (due to the pendulum equations of motion) would be taking longer than 2 sec.
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 01:51 am
....

From the first photo that you attached, it looks to me like the horizontal 1 1/2 inch beam on the far side of the thruster, and the end of the lower 1 1/2 inch beam on the near side of the thruster are just about equidistant from the center of the base plate of the thruster. Measuring distance perpendicular to the axis of the cone, that is. Setting our reference length to the average measured 1 1/2 inches should give a better reference than using one or the other.

Great observation aero !

John, could you please re-draw when you have a chance and the disposition  :)
Title: Re: EM Drive Developments
Post by: zen-in on 10/26/2014 01:18 am
... Before embarking onto Shawyer's devices leaks (BTW can someone answer to this apparently simple question : has superconducting EMdrive been tested yes or no ? ...
There is this about Cannae's superconducting test

http://web.archive.org/web/20121102082714/http://www.cannae.com/proof-of-concept/experimental-results

Quote
On January 13, 2011, Figure 1 was generated by sending 10.5 watt power pulses of 1047.335 MHz RF phase-locked power forward to the POC resonating cavity located in the experimental apparatus. The POC cavity is operated in the TM010 mode. Figure 1 shows 6 dips in the compressive force on the load cells. These 6 dips in the load-cell outputs coincide with the 10.5 watt power pulses sent into the cavity from the signal-generation circuit. Figure 1 also shows 2 positive peaks in the voltage signal coming from the load cells. These positive peaks resulted from placing a 2-gram calibrated weight onto the support arm that supports the POC cavity and vacuum tubing. Figure 1 was generated 65 minutes after bringing the pressure over the liquid helium bath up to atmospheric pressure from a pump-down pressure of 50 Torre. The 6 dips in voltage in Figure 1 correspond to a reduction in compressive force on the load cells of 8-10 mN.

The upward drift of the load-cell voltage output of Figure 1 occurred with and without power being sent to the POC cavity. Moisture condensation on the cold equipment and signal drift (within specifications) of the load cells, contributed to the drift of the voltage output. The frequency of the drift in load-cell output is much lower than the frequency of the power pulses sent into the cavity and the calibration pulses.  The dips in load-cell voltage output during power-pulse cycles is clearly visible against the background signal drift.

(http://web.archive.org/web/20121102082714im_/http://www.cannae.com/images/test_run2.gif)

The boiling point of helium at atmospheric pressure is 4.2 K.   I have seen it boil at 4.3 K but that usually indicates a slight constriction in the vent tube.   At 4.2 K the liquid Helium in the dewar would have bubbles in it.   When a 10.5 Watt pulse of RF power is dissipated in the dewar the heat generated will boil off more Helium.   Not enough information has been provided to resolve this discrepancy.   

I don't understand this statement:
"Figure 1 was generated 65 minutes after bringing the pressure over the liquid helium bath up to atmospheric pressure from a pump-down pressure of 50 Torre. "

If the pressure over the liquid Helium bath was 50 torr  (50/760 atmospheres) wouldn't the Helium just boil off?

It only takes a few microWatts to cause noticeable boil off in a Helium dewar.   10.5 Watts is a lot of power, even for a few seconds.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/26/2014 01:23 am
Quote
Can anyone please provide Dr. White's equation to predict the thrust force from his electron-positron virtual particle quantum vacuum theory?

Does this help?  From Doctor White, back in 2007.  Can't make heads or tails out of it:

http://adsabs.harvard.edu/abs/2007AIPC..880..987W

Abstract:

Quote
The intent of this narrative is to propose a relationship between the vacuum energy density, light-radius of the universe, and the plank force. The equation is proposed to infer a connection between inertial mass and an observer's light horizon. This horizon is conjectured to be the mean free path for vacuum fluctuations as seen by an observer in deep space. This fundamental relationship will then be derived from a gravitational wave equation. Once this has been derived, the results will be extended to derive an equation to calculate the effect local matter has on the mean free path of a vacuum fluctuation, and hence the local vacuum energy density (vacuum fluctuation pileup). The paper will conclude by applying the theoretical framework to calculate expected thrust signals in an externally applied ExB application meant to induce plasma drift in the vacuum fluctuations. Current experimental results from domestic and international labs will be addressed.

The meat of the article runs $28, though. 
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 01:50 am
Quote
Can anyone please provide Dr. White's equation to predict the thrust force from his electron-positron virtual particle quantum vacuum theory?

Does this help?  From Doctor White, back in 2007.  Can't make heads or tails out of it:

http://adsabs.harvard.edu/abs/2007AIPC..880..987W

Abstract:

Quote
The intent of this narrative is to propose a relationship between the vacuum energy density, light-radius of the universe, and the plank force. The equation is proposed to infer a connection between inertial mass and an observer's light horizon. This horizon is conjectured to be the mean free path for vacuum fluctuations as seen by an observer in deep space. This fundamental relationship will then be derived from a gravitational wave equation. Once this has been derived, the results will be extended to derive an equation to calculate the effect local matter has on the mean free path of a vacuum fluctuation, and hence the local vacuum energy density (vacuum fluctuation pileup). The paper will conclude by applying the theoretical framework to calculate expected thrust signals in an externally applied ExB application meant to induce plasma drift in the vacuum fluctuations. Current experimental results from domestic and international labs will be addressed.

The meat of the article runs $28, though.

This is the 2007 presentation  "Inertial Mass Dependency on Local Vacuum Fluctuation Mean Free Path":  http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=13020.0;attach=173105

It contains his derivation for local vacuum energy density (simply the geometric average of the vacuum density and the local material density) but never an equation for the thrust force, just numerical results.

Readers: please notice that Dr. White's proposed force acts perpendicular to both the electric (E) and magnetic (B) fields, so for the transverse electric (TE) modes of resonance of the truncated cone that were researched, the force calculated by Dr. White would act in the radial direction of the truncated cone (because the B field is axial, and the E field is in the circumferential direction of the cone).

Notice that as early as 2007 Dr. White was writing that "a dielectric inside the cavity would increase the available Quantum Vacuum Plasma density", similar to what Brady wrote in the report when they were learning their way around and did not report the Q or any numbers, and tested at a frequency higher than the one for the reported values.

I don't understand what he means by "plasma" when referring to the quantum vacuum or why a dielectric would increase such plasma.  Apparently the "quantum vacuum plasma local density" he uses for his formula is the geometric average of the quantum vacuum density and the density of the dielectric.  Apparently he "models" the electron-positron virtual particle pairs as a plasma?  No explanation on what could make the virtual particles become real or behave like a plasma.  He writes that Woodward's model is "slightly different".

Maybe aero has more patience than me and can find an equation in this presentation that we can use to compare with Shawyer's and McCulloch's predictions.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/26/2014 08:42 am

WEll, I gotta say, I'm learning a lot about people, am getting practice in scientific rhetoric, and learning somewhat less math than French, but hey.

Best I can tell, is that the mhe math whiz bangs here think that something could be happening, and are snapping their synapses over just what could be happening that is consistent with the reported results.

Although I'm with you on the sloppy experimental protocols, even by amateur standards.

I guess it's all relative, then. While I'm sure the people here are no less brilliant when it comes to matters of applied science and technologies, they really are (for the most part) clueless when it comes to matters of fundamental physics and advanced mathematics from what I've seen. Just skimming this thread confirms my suspicion. Mostly algebraic manipulations of rather simple Newtonian equations and some differential calculus sprinkled in, nothing you wouldn't see in a first year math class. Where are the action principles? Or how about the symmetry arguments that would then trivially lead to the conservation laws via Noether's theorem? And for those pushing the quantum vacuum plasma "model", what is the form of the quantum fields (and these have to be there) in your model? Where are the path-integrals that should explain the interactions of those fields? I would be more impressed by such a model even if its path integrals diverged. I don't even see math that is appropriate for quantum mechanics in the low-energy limit, such as density functional theory, fourier transforms, abstract linear algebra, etc.



If you want to learn physics, I strongly recommend not learning based on the speculations of bored engineers. When it comes to everything else on this forum, these are generally the perfect people to learn from. But with these fringe topics, I humbly believe you're better off building your physical intuition from the classic textbooks so then you would at least be armed with the correct intuition to sift between the speculatively plausible and the outright nonsensical.

I can't begin to guess how many pages were about symmetries and conservation laws. Make sure you read before you criticize the group. How about you bring some new insight to the table?

Edited to be nice.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/26/2014 08:50 am
Can the polymer gasket between the base plate and the cone act as a dielectric barrier discharge (DBD) actuator?

 I like where you're going with this, but I can't see how this ...applies ... because of the penetrating bolt through the whole assembly of the test device, which are conductive. I dismissed them because of this. ..

How can we possibly know the electrical conductivity of the bolts they used to attach the base plates to the copper cone?  Is there information about the type of bolts that were used ?

And the bolts are not going through the copper cone but they thread through to flanges.  How are the flanges themselves made and/or attached to the cone?

Well I assembled a team of maverick engineers and scientists. They said that metal bolts conduct electricity. I confirmed this experimentally with my multimeter. The same result with steel, aluminum and copper bolts, all short circuits. Nylon bolts measured as an open. A conference paper is to follow. Attached are the formulas I used in my derivation. Please standby for preprint.  :D
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/26/2014 09:39 am
Suffice to say, the only reason this thread has gone on as long as it has is because the people interested haven't been clever enough (myself certainly included) to devise a completely satisfactory, conventional, "the device doesn't actually do anything of interest" explanation for the measured thrust.

We're not all lunatic crackpots... honest!
Title: Re: EM Drive Developments
Post by: Mulletron on 10/26/2014 10:15 am
http://www.falstad.com/mathphysics.html

Neat

http://www.youtube.com/watch?v=5BPC9fWqkDw&list=PLL3KaSy9VMmsewiYTNlonomllra6xbYVp&index=4

Start at 1:25

Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 12:38 pm
Notice that Dr. White's proposed "quantum vacuum" force acts perpendicular to both the electric (E) and magnetic (B) fields, so for the transverse electric (TE) modes of resonance (shown in the truncated cone below) that were researched, the force (from plasma source to plasma sink) calculated by Dr. White would act in the radial direction of the truncated cone (because the B field is axial (vertical), and the E field is in the circumferential direction of the cone).

According to Dr. White's "quantum vacuum plasma" formulation, there would be no action in the direction that the thrust forces were measured:  the (vertical) axial direction of the truncated cone.

Electric field (E) in red (circumferential arrows)

Magnetic field (B) in blue (axial arrows)  (Vertical direction)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/26/2014 01:24 pm


According to Dr. White's "quantum vacuum plasma" formulation, there would be no action in the direction that the thrust forces were measured:  the (vertical) axial direction of the truncated cone.


I arrived at the same conclusion. I could not find any preferred direction of thrust using White's formulation, which is why I have been trying to invoke asymmetries (via the cone shape (very slightly modified shape of spacetime from perfectly isotropic, and more toward the shape of the frustum) and chirality). Those were my leaps. My leap was that our isotropic spacetime is a product of all interactions, so if I block some of those interactions via the cone shape, spacetime is no longer perfectly isotropic, giving rise to an opportunity to bias inertia one way more than the other.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/26/2014 01:31 pm
Also, can somebody tell me how you get momentum out of group velocity?

'Cuz I thought there was no relationship whatsoever between the two.

Yes certainly, that is easy to show. ...

Who does the good doctor think I (http://en.wikipedia.org/wiki/Dumb_and_Dumber) am?  I use the oracle for all my entertainment needs!

Of course, the doc hisself could use a dictionary.  Note his "careful words":

Quote from: Don't even ask
momentum = groupveloctiy * mass

Check the oracle!  Dey ain't no such thing as "veloctiy".  sheesh.

But on the serious side, the oracle is the only reference tool I have at hand.

The group velocity of a wave is the velocity with which the overall shape of the waves' amplitudes — known as the modulation or envelope of the wave — propagates through space. (http://en.wikipedia.org/wiki/Group_velocity)

My understanding is that you can't multiply this by mass and get any movement of the mass.  Movement of mass implying some kind of velocity with an associated momentum.

Primitive man try for half hour to get it. Me not get it.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/26/2014 01:35 pm
....
> Tau=2s (really uncertain, typical rise time, could be much lower)
....
I modeled the nonlinear coupled equations of motion (obtained from solving the Lagrangian) of the inverted torsional pendulum with Mathematica.

The 2 seconds rise is purely due to the inertial response of the equations of motion to an impulsive rectangular pulse.   There is no doubt about it.  It is due purely to the mass, damping and stiffness matrices of the pendulum.  The 2 sec rise is not due to a time-dependent-loading that takes 2 sec to reach full load.

So what one needs to find is an experimental artifact that acts like an instantaneous  (within the time scale), impulsive pulse.  Not one that takes 2 sec to reach full load.  If the loading function itself would take 2 seconds to reach full load, the response (due to the pendulum equations of motion) would be taking longer than 2 sec.

I don't put in doubt your model but from what I see from "anomalous thrust... (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf)" Brady page 15 fig. 19 the underdamped ringing could easily blur the distinction between a step excitation and a more gentle first order rise with time constant about 1s. For what we see with the rectangular pulses of calibration (dips in fig 19, also fig 20 and fig 21 at better scales) the first overshoot is typically bigger (deviation from later averaged drifting baseline response during the pulse) than the second crest 2s later (the other side of the later average). This is far from obvious with the step excitations of the thruster, quite the contrary it appears the first crest  /\ top is closer (to the overall pulse response baseline) than the second crest \/ bottom. The same remarks apply for the fall : first ringing (overshoot) has bigger relative magnitude (to the following level) than the second for calibration pulses, not for thruster pulses.

Those are just words but really I would be surprised if the thrust excitation giving such response were really instantaneous. A first order rate effect with time constant 1 would be at 63% its later level after 1s, 86% after 2s (first ringing overshoot), 98% after 4s (second ringing crest). How would you exclude such a 1s (or even 2s) rise time from those experimental diagrams, have you scraped the data from the images and run that through a deconvolution filter of some sort ? Short of that I remain sceptical of the inevitability to exclude quite not instantaneous, around 1s rise/fall time, candidate effects.

Is it possible to include attached (uploaded) pictures in the body of a post ?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/26/2014 01:42 pm
... the whole debacle with CERN and the superluminal neutrinos...

Well, I didn't read that as a "debacle". 

The impression I got was twofold;  First, the breathless announcement for the purpose of wowing the public and ensuring political interest in the funding stream.  Second, the CERN guys sharing ALL of their results with the community, to find out that they had made a mistake.

The first part is as annoying as considering absurdly benign wormholes, but the second part, I thought, was how science was supposed to work.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/26/2014 01:51 pm
people here are ... clueless when it comes to matters of fundamental physics and advanced mathematics from what I've seen.

How about a bit more explanation for us clueless dummies, rather than casual dismissal with blatantly obvious oversimplifications? Like:

Quote from: SuperGenius
...nothing you wouldn't see in a first year math class...

Obviously you're one of those reasonably educated (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255287#msg1255287) individuals, and those of us who use the oracle aren't?

Besides, I'm a better dancer than you are anyhow.  sheesh.
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 02:03 pm
...
I don't put in doubt your model but from what I see from "anomalous thrust... (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf)" Brady page 15 fig. 19 the underdamped ringing could easily blur the distinction between a step excitation and a more gentle first order rise with time constant about 1s. For what we see with the rectangular pulses of calibration (dips in fig 19, also fig 20 and fig 21 at better scales) the first overshoot is typically bigger (deviation from later averaged drifting baseline response during the pulse) than the second crest 2s later (the other side of the later average). This is far from obvious with the step excitations of the thruster, quite the contrary it appears the first crest  /\ top is closer (to the overall pulse response baseline) than the second crest \/ bottom. The same remarks apply for the fall : first ringing (overshoot) has bigger relative magnitude (to the following level) than the second for calibration pulses, not for thruster pulses.

Those are just words but really I would be surprised if the thrust excitation giving such response were really instantaneous. A first order rate effect with time constant 1 would be at 63% its later level after 1s, 86% after 2s (first ringing overshoot), 98% after 4s (second ringing crest). How would you exclude such a 1s (or even 2s) rise time from those experimental diagrams, have you scrapped the data from the images and run that through a deconvolution filter of some sort ? Short of that I remain sceptical of the inevitability to exclude quite not instantaneous, around 1s rise/fall time, candidate effects.

Is it possible to include attached (uploaded) pictures in the body of a post ?

Quote
Those are just words but really I would be surprised if the thrust excitation giving such response were really instantaneous.   

Of course, that's why I wrote <<So what one needs to find is an experimental artifact that acts like an instantaneous  (within the time scale>> resolution.  We can only tell how impulsive the response is from the graph.  From measuring the graph, to me this is about within ~0.2 seconds, so meet me somewhere in-between (I think that 1 sec to 2 sec is too much, as we can discriminate 1 sec to 2 sec  from the graph). 

Quote
This is far from obvious with the step excitations of the thruster, quite the contrary it appears the first crest  /\ top is closer (to the overall pulse response baseline) than the second crest \/ bottom. The same remarks apply for the fall : first ringing (overshoot) has bigger relative magnitude (to the following level) than the second for calibration pulses, not for thruster pulses
Yes, the measured force (whatever its origiin) is not a pure step.  The measured force vs time however, as you know, should not be interpreted as being a replica of the thruster excitation.  Due to the complicated measuring system (an inverted torsional pendulum with nonlinear coupling between swinging and torsion) there are many natural modes of resonance and if the thruster response instead of being a pure step has different frequencies of excitation, the measured response will amplify the frequencies that are near the natural frequencies (some of them parasitic) of the inverted pendulum.

Quote
How would you exclude such a 1s (or even 2s) rise time from those experimental diagrams, have you scrapped the data from the images and run that through a deconvolution filter of some sort ?

Yes, actually, I was planning to do that.  If we can come up with a proposed input excitation (whether an artifact or a real thrust) it would be easy for me to input it in Mathematica and see how it compares with the actual response.

This is an imperfect analogy, but similar argumentation as you very well noticed the InputPower^2 response of the model vs the InputPower^1 actual response
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/26/2014 02:09 pm
I can't begin to guess how many pages were about symmetries and conservation laws. Make sure you read before you criticize the group. How about you bring some new insight to the table?

Izzat a lot? (http://www.youtube.com/watch?v=WPcwsJ2aYEA)
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 02:12 pm
http://www.falstad.com/mathphysics.html

Neat

...

Start at 1:25
Yes neat video.  Besides it being an interesting demonstration (we agree on that), do you see here something that could throw a light into the reason for the measured thrust in the EM Drives?
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 02:18 pm
people here are ... clueless when it comes to matters of fundamental physics and advanced mathematics from what I've seen.

How about a bit more explanation for us clueless dummies, rather than casual dismissal with blatantly obvious oversimplifications? Like:

Quote from: SuperGenius
...nothing you wouldn't see in a first year math class...

Obviously you're one of those reasonably educated (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255287#msg1255287) individuals, and those of us who use the oracle aren't?

Besides, I'm a better dancer than you are anyhow.  sheesh.
Or how about a constructive contribution rather than subjective wordy opinions, a contribution showing what is meant by "higher math" by actually analyzing with "higher math" the EM Drives as an experimental artifact, using what is considered to be non-first year math class?  (the example given of a Fourier transform as being such "higher math" implies an assumption of ergodicity and stationarity, both of which are not met by many physical processes. )
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 02:28 pm
Also, can somebody tell me how you get momentum out of group velocity?

'Cuz I thought there was no relationship whatsoever between the two.

Yes certainly, that is easy to show. ...

Who does the good doctor think I (http://en.wikipedia.org/wiki/Dumb_and_Dumber) am?  I use the oracle for all my entertainment needs!

Of course, the doc hisself could use a dictionary.  Note his "careful words":

Quote from: Don't even ask
momentum = groupveloctiy * mass

Check the oracle!  Dey ain't no such thing as "veloctiy".  sheesh.

But on the serious side, the oracle is the only reference tool I have at hand.

The group velocity of a wave is the velocity with which the overall shape of the waves' amplitudes — known as the modulation or envelope of the wave — propagates through space. (http://en.wikipedia.org/wiki/Group_velocity)

My understanding is that you can't multiply this by mass and get any movement of the mass.  Movement of mass implying some kind of velocity with an associated momentum.

Primitive man try for half hour to get it. Me not get it.
You asked for an example. I gave you an example where momentum = groupvelocity *mass, exactly. 

The Wikipedia article defines the group velocity in exactly the same way that I defined it: as the partial derivative of the angular frequency with respect to the wavenumber.  See everything that the wikipedia article states under definition.

The relationship of group velocity to phase velocity depends on the dispersion relation.

Due to dispersion, wave velocity is not uniquely defined, giving rise to the distinction of phase velocity and group velocity when the dispersion relation is not linear.

Don't worry about not understanding this right away.  (Nonlinear) Dispersion is a nonlinear phenomenom, therefore it is non-intuitive:  human minds are good at thinking linearly, and not about thinking nonlinearly.  Nonetheless we live in a world where radiowaves, waterwaves, electromagnetic waves, encounter nonlinear dispersion.  In a perfect vacuum the dispersion relation is linear, but we humans don't live in a vacuum.

I don't like the fact that people that don't identify themselves with their real name, but instead use monickers, can constantly write and modify Wikipedia articles, at their will,  but if you like to use use it, here is the article on Wikipedia on dispersion that applies:  http://en.wikipedia.org/wiki/Dispersion_relation

or, better, this lecture (video):  http://ocw.mit.edu/courses/physics/8-03-physics-iii-vibrations-and-waves-fall-2004/video-lectures/lecture-12/

physical demonstration starting approximately at 1:10

The MIT Prof. (Lewin) discusses cut-off frequency, nonlinear dispersion, group velocity and a lot of the stuff we are discussing.  The lecture is at an introductory level (the third Physics course for undergraduates).

(http://upload.wikimedia.org/wikipedia/commons/e/ea/KEvsMOMENTUM.png)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/26/2014 02:52 pm
http://www.falstad.com/mathphysics.html

Neat

...

Start at 1:25
Yes neat video.  Besides it being an interesting demonstration (we agree on that), do you see here something that could throw a light into the reason for the measured thrust in the EM Drives?

The video is a neat demonstration of the link between optics and rf. No dichotomy is required. Optics gets all the attention due to its familiarity in daily life. Hence why the refractive index we commonly encounter is actually based off of an optical value of 589nanometers. Foam and wax are to rf prisms as glass is to optical prisms. Just a neat thing I found while researching evanescent wave coupling/quantum tunneling. I have to force myself to think a different/better way so I can apply this to copper cans.

http://www.youtube.com/watch?v=q7Q8l3xKyr4
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 03:53 pm
,,,,,
You asked for an example. I gave you an example where momentum = groupvelocity *mass, exactly. 

The Wikipedia article defines the group velocity in exactly the same way that I defined it: as the partial derivative of the angular frequency with respect to the wavenumber.  See everything that the wikipedia article states under definition.

The relationship of group velocity to phase velocity depends on the dispersion relation.

Due to dispersion, wave velocity is not uniquely defined, giving rise to the distinction of phase velocity and group velocity when the dispersion relation is not linear.

I don't like the fact that people that don't identify themselves with their real name, but instead use monickers, can constantly write and modify Wikipedia articles, at their will,  but if you like to use use it, here is the article on Wikipedia on dispersion that applies:  http://en.wikipedia.org/wiki/Dispersion_relation

or, better, this lecture (video):  http://ocw.mit.edu/courses/physics/8-03-physics-iii-vibrations-and-waves-fall-2004/video-lectures/lecture-12/

physical demonstration starting approximately at 1:10

The MIT Prof. (Lewin) discusses cut-off frequency, nonlinear dispersion, group velocity and a lot of the stuff we are discussing.  The lecture is at an introductory level (the third Physics course for undergraduates).



If you like Wikipedia, also see the article on cut off frequency http://en.wikipedia.org/wiki/Cutoff_frequency

the cut off frequency for waveguides:
Quote
The value of c, the speed of light, should be taken to be the group velocity of light in whatever material fills the waveguide

and the relationship to dispersion (Prof. Lewin in his lecture -video above-  shows the nonlinear dispersion [omega vs kz] occurring near the cut off frequency for his example).

Quote
The wave equations are also valid below the cutoff frequency, where the longitudinal wave number is imaginary. In this case, the field decays exponentially along the waveguide axis and the wave is thus evanescent.
 
Title: Re: EM Drive Developments
Post by: frobnicat on 10/26/2014 04:12 pm
 @John,
Concerning group velocity and momentum, maybe you should start from this phrase of the oracle (http://en.wikipedia.org/wiki/Group_velocity#Physical_interpretation) :
"The group velocity is often thought of as the velocity at which energy or information is conveyed along a wave."

Group velocity is velocity of energy, read mass_energy as the two are equivalent. Speed of energy_mass times amount of energy_mass yields momentum.

"However, if the wave is travelling through an absorptive medium, this does not always hold."
From this point onward I give up, dr Rodal's erudite answers are your only recourse.
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 06:05 pm
New post by Dr.McCulloch, using two McCulloch formulas:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-updated-table.html


incorporating the superconducting Cannae test
http://web.archive.org/web/20121104025749/http://www.cannae.com/proof-of-concept/design

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC_fig_1.gif)
(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC_fig_2.gif)
(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC.fig3.jpg)
(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC_design_figure42.jpg)
Title: Re: EM Drive Developments
Post by: frobnicat on 10/26/2014 06:10 pm
Quote
Those are just words but really I would be surprised if the thrust excitation giving such response were really instantaneous.   

Of course, that's why I wrote <<So what one needs to find is an experimental artifact that acts like an instantaneous  (within the time scale>> resolution.  We can only tell how impulsive the response is from the graph.  From measuring the graph, to me this is about within ~0.2 seconds, so meet me somewhere in-between (I think that 1 sec to 2 sec is too much, as we can discriminate 1 sec to 2 sec  from the graph). 

I won't bargain on that, I stand on 1s to 2s rise (and fall) times are compatible with what we see of fig. 19 and fig. 21 Brady's anomalous thrusts. This is not a matter of time scale resolution, this is a matter of settling time of the "filter" constituted by the balance when step like signals are applied. This is an important matter as actual thrust vs time (when power is rectangular pulse) is a strong constraint on possible explanations. I'm considering the RF power generator has a very short time constant, and the standing resonant microwave reaches stationary amplitudes in µs, so from the point of view of RF energy or power we have instantaneous input excitation of the drive at nominal values for all practical purpose. The question is the time behaviour of the thrust output of the device from this rectangular power input. I don't see how real effects (momentum conservation with ghostly particles or local cosmic horizon) could have "inertia" in the thrust/power ratio for longer than a few µs (Q times length_of_cavity/c)

Quote
Quote
This is far from obvious with the step excitations of the thruster, quite the contrary it appears the first crest  /\ top is closer (to the overall pulse response baseline) than the second crest \/ bottom. The same remarks apply for the fall : first ringing (overshoot) has bigger relative magnitude (to the following level) than the second for calibration pulses, not for thruster pulses
Yes, the measured force (whatever its origiin) is not a pure step.  The measured force vs time however, as you know, should not be interpreted as being a replica of the thruster excitation.  Due to the complicated measuring system (an inverted torsional pendulum with nonlinear coupling between swinging and torsion) there are many natural modes of resonance and if the thruster response instead of being a pure step has different frequencies of excitation, the measured response will amplify the frequencies that are near the natural frequencies (some of them parasitic) of the inverted pendulum.

Not clear to me, can we clarify terminology ?

P(t) : Microwave power input to the thruster (instantaneous compared to time scales, rectangular pulse)
F(t) : thrust output of the thruster (the interesting magnitude vs time shape, perfect steps or not ?)
Fb(t) : excitation input of the balance (almost the same as F, but with added DC power parasitic term )
Obs(t) : Measure output of the balance (as displacement, with natural frequencies, underdamped...)

"if the thruster response instead of being a pure step..." you are referring to F ?

Quote
Quote
How would you exclude such a 1s (or even 2s) rise time from those experimental diagrams, have you scrapped the data from the images and run that through a deconvolution filter of some sort ?

Yes, actually, I was planning to do that.  If we can come up with a proposed input excitation (whether an artifact or a real thrust) it would be easy for me to input it in Mathematica and see how it compares with the actual response.

Input excitation of balance, that is Fb ?

Ok, could we try with 3 easy ones :

- Pure rectangle, 30 seconds
    Fb(t) = cst for 0<t<30
    Fb(t) = 0 otherwise

- "charge/discharge" rectangle : first order tau=1s rise and decay 
    Fb(t)=0 for t<0
    Fb(t)=cst*(1-exp(-t/1)) for 0<t<30
    Fb(t)=cst*exp(-(t-30)/1) for 30<t

- "charge/discharge" rectangle : first order tau=2s rise and decay 
    Fb(t)=0 for t<0
    Fb(t)=cst*(1-exp(-t/2)) for 0<t<30
    Fb(t)=cst*exp(-(t-30)/2) for 30<t

cst = target constant amplitude (say 80µN)

What is experimental data resembling most ?

Quote
This is an imperfect analogy, but similar argumentation as you very well noticed the InputPower^2 response of the model vs the InputPower^1 actual response

This was for one Shawyer's thrust vs power graph. I prefer to concentrate on Brady, as someone put it (you ? Aero ? Mulletron ?) it is better documented, and maybe of more reliable value. I don't completely give up on this "warm jet effect". Even if it seems unlikely it would have been gone unnoticed and gave results somehow in agreements between different labs, the alternatives are either as much hazardous (magnetic couplings) or more hard to swallow (axions anyone ?)

We don't even know from the experimenters the most basic geometric characteristics of their device. Who know (save them) how much they are tinkering with things before "it works", what kind of "secret recipe" procedures are followed and in which we could maybe see some confirmation or invalidation of such or such possible explanation. One thing stands out : the effect is hard to get at, and that's not because of ultra faint magnitude (µN when nN are "routinely" investigated with short range gravitation studies). So what makes it so hard to make it reproducible and reliable ? Driving a high Q at resonant frequency ? Mmm. Well. Maybe. Only maybe.

My latest derivation for the warm air jet hypothesis : F in function of microwave volumetric heating Pow and tau time constant of the rise/fall

F = Cf/rho * ((2*p*Tau)/V)^0.5 * (Pow/(C*T))^1.5

That is by using numerical values for almost constants ( 20°C ambient ... )
F = 1.41e-6 * 1/sqrt(V) * sqrt(Tau) * Pow^1.5

V=0.027m^3  Tau=2s  Pow=4W  yields F=97µN

But that needs tinkering until the leak area A is small enough (but not stoppered) to give high thrust, but big enough so that Tau is below some level (otherwise you see a ramp up). How much tinkering is going on ?
F = 9.7e-12 * Pow^2/A
Tau = 4.74e-11 * V*Pow/A^2

Intuitively I'm in favor of some electromagnetic explanation, but think this is still worth investigating.
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 06:47 pm
... The question is the time behaviour of the thrust output of the device from this rectangular power input
Here it looks to me that we were referring to different things.  The inverted torsional pendulum has a time response to an (instantaneous) impulsive load of 2s, not 1s
Quote
Not clear to me, can we clarify terminology ?

P(t) : Microwave power input to the thruster (instantaneous compared to time scales, rectangular pulse)
F(t) : thrust output of the thruster (the interesting magnitude vs time shape, perfect steps or not ?)
Fb(t) : excitation input of the balance (almost the same as F, but with added DC power parasitic term )
Obs(t) : Measure output of the balance (as displacement, with natural frequencies, underdamped...)

"if the thruster response instead of being a pure step..." you are referring to F ?
It's great that you realize that we are referring to different quantities and the best way to resolve this is to define what we mean.  Here I was saying (admittedly in less than perfect language) that if Fb(t) instead of being an impulse has a significant delay-to-reach-steady-state (time-dependent rise), then Obs(t) will have a response longer than 2 sec.  From my side I'm a black box that if given Fb(t) as an input, I can give you Obs(t) as an output.

I make no comments whatsoever on P(t) and F(t).

Quote
Input excitation of balance, that is Fb ?

Ok, could we try with 3 easy ones :

- Pure rectangle, 30 seconds
    Fb(t) = cst for 0<t<30
    Fb(t) = 0 otherwise

- "charge/discharge" rectangle : first order tau=1s rise and decay 
    Fb(t)=0 for t<0
    Fb(t)=cst*(1-exp(-t/1)) for 0<t<30
    Fb(t)=cst*exp(-(t-30)/1) for 30<t

- "charge/discharge" rectangle : first order tau=2s rise and decay 
    Fb(t)=0 for t<0
    Fb(t)=cst*(1-exp(-t/2)) for 0<t<30
    Fb(t)=cst*exp(-(t-30)/2) for 30<t

cst = target constant amplitude (say 80µN)

What is experimental data resembling most ?

It's great working with you. That's exactly what I needed.

However, now I'm going to enjoy the Sun.  I'll work on that when the Sun goes away  :)
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/26/2014 07:27 pm
Conclusion from the 'experimental results' section of the Cannae drive page.


Quote
When operated with a TM010 EM wave, the QDrive POC cavity generates a linear net imbalance of Lorentz forces exerted on the cavity. FEM numerical predictions for net unbalanced Lorentz force on the POC cavity is within 40% of experimental results. Variations between experimental results and numerical method predictions are within the margin of error based on limitations of the experimental measurements of Cavity Q. EM field energy in the POC cavity during experimental runs was less than 3% of design maximum. Field energy levels in the experiment limit correlations between numerical method predictions and experimental results.

'...linear net imbalance of Lorentz forces?'  Does this mean 'thrust?'

'...less than 3% of design maximum?'  Does this mean he could have created an imbalance on the order of 33 times greater than what was measured? 

Apart from that, I note a lot of pages under construction on that site...including some very interesting ones. 
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 07:44 pm
Conclusion from the 'experimental results' section of the Cannae drive page.


Quote
When operated with a TM010 EM wave, the QDrive POC cavity generates a linear net imbalance of Lorentz forces exerted on the cavity. FEM numerical predictions for net unbalanced Lorentz force on the POC cavity is within 40% of experimental results. Variations between experimental results and numerical method predictions are within the margin of error based on limitations of the experimental measurements of Cavity Q. EM field energy in the POC cavity during experimental runs was less than 3% of design maximum. Field energy levels in the experiment limit correlations between numerical method predictions and experimental results.

'...linear net imbalance of Lorentz forces?'  Does this mean 'thrust?'

'...less than 3% of design maximum?'  Does this mean he could have created an imbalance on the order of 33 times greater than what was measured? 

Apart from that, I note a lot of pages under construction on that site...including some very interesting ones.

If they get a "net imbalance of Lorentz forces" it means that they get thrust, yes, but it also means to me that the Finite Element problem was not well posed if they are dealing with classical physics (Maxwell's equations and equations or equations of motion from a Lagrangian or Hamiltonian).

To obtain a finite element solution one of the things one has to be careful of are the boundary conditions. 

If one deals with the free-free body floating in space, the finite-element matrix is singular (the determinant of the matrix is zero) because a free-free body has rigid-body modes.  In order to obtain a proper solution one has to identify the rigid-body modes and extract them from the finite-element solution in order to obtain a non-singular matrix and hence a solution.  I don't know what Finite Element code they used or how they went about eliminating the rigid-body modes but I do know that if you pose the problem correctly using classical physics (as done by Greg Egan) there should be conservation of momentum and hence hence no acceleration of the center of mass.  Therefore if they obtain unbalanced forces in the FEM solution the following has to be addressed:

a) properly taking into account hidden momentum
b) correct treatment of boundary conditions
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/26/2014 08:20 pm
You asked for an example. I gave you an example where momentum = groupvelocity *mass, exactly.

The Wikipedia article defines the group velocity in exactly the same way that I defined it...

I was noticing the similarity between your explanation and that of the oracle, which caused a bit of head scratching at your seeming dismissal of the oracle.  I need to study a bit more, my good troglodite.

As always, appreciate your pedagology.  That chart is most excellent!
Title: Re: EM Drive Developments
Post by: Rodal on 10/26/2014 08:47 pm
You asked for an example. I gave you an example where momentum = groupvelocity *mass, exactly.

The Wikipedia article defines the group velocity in exactly the same way that I defined it...

I was noticing the similarity between your explanation and that of the oracle, which caused a bit of head scratching at your seeming dismissal of the oracle.  I need to study a bit more, my good troglodite.

As always, appreciate your pedagology.  That chart is most excellent!

Perhaps the problem you are confronting is that Newton's corpuscular theory of light is wrong.
Experiments show, that single photons travel through glass at the group velocity of light.
John, we must come to grips with this fact: classical (Newtonian) mechanics demands that the momentum of the photons be greater in water than in air, even  though the measurements show that the opposite relationship holds for their velocity.

EDIT:

So the best way out of your conundrum, is to think (in a Rodalian way) of photons as particles that have a different relativistic mass in different media, according to the media's refractive index.  Think of the photons as experiencing a greater increase of relativistic mass with refractive index than does their momentum, hence resulting in the experimentally-observed decrease in light (group) velocity.

Or, if you don't like thinking that way, stop thinking of photons as particles !.

Yes that chart, repeated here again, focuses on what matters: energy and momentum (in the vertical and horizontal axis), with mass as being the contours on the chart.  Nice to see "humans" there.  I couldn't find the troglodites contour, though.

(http://upload.wikimedia.org/wikipedia/commons/e/ea/KEvsMOMENTUM.png)
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/26/2014 10:22 pm
Quote
If they get a "net imbalance of Lorentz forces" it means that they get thrust, yes, but it also means to me that the Finite Element problem was not well posed if they are dealing with classical physics (Maxwell's equations and equations or equations of motion from a Lagrangian or Hamiltonian).

Hmmm...So, there is either

1) An error of some sort with the experiment (Finite Element and/or boundary conditions);

2) They are mucking around with exotic physics where the problems with point one are modified or don't apply;

3) Classical physics has a here-to-for unknown problem or loophole this drive takes advantage of.


I can see how a classically educated scientist would really, really want the answer to be point 1.  Point 2 means a scientific revolution of a sort not seen in decades, maybe centuries.   But if a classically educated scientist can't find the answer in point 1, and can't accept point 2...then point 3 might be acceptable...on alternate Tuesdays, with maybe the occasional Saturday afternoon thrown in.
Title: Re: EM Drive Developments
Post by: aero on 10/26/2014 11:50 pm
Very interesting. So how much thrust would be calculated for a right circular cylinder filled half way with a dielectric?

Choose your own dielectric constant and don't worry about can length. The can has a Q value of 50,000 which seems easy.
Title: Re: EM Drive Developments
Post by: Rodal on 10/27/2014 12:35 am
I received this message from Robert Ludwick, that I reproduce in its entirety:

From: Robert Ludwick
Sent: Friday, October 24, 2014 9:04 AM
To: Dr. J. Rodal
Subject: Testing the EmDrive
 
Hello Dr. Rodal,
 
In reference to:

Quote
the NASA Eagleworks tests show a pulse response rapidly rising in 2 seconds which coincides with the inertial response of the inverted torsional pendulum

If the pendulum response time is 2 seconds for every frequency step, this means we need really big batteries or revising the test plan to include external power through the liquid metal low friction contacts as done in the original tests, since the drive amplifier is powered up for the entire test.
 
I still think that the fixed power/swept frequency approach is better than the fixed frequency/pulsed power approach.   

The fixed power/swept frequency approach guarantees that at least one and probably several measurements will be made at the peak thrust frequency and that the measured thrust (if any) is not an artifact of  current pulses, air convection, or anything similar, as test current and power dissipation remain constant for the entire test and the only test variable is frequency. It will also demonstrate that the thrust is a function of cavity Q, since Q is the only "Device Under Test characteristic" that is frequency dependent.
 
Bob Ludwick
Title: Re: EM Drive Developments
Post by: aero on 10/27/2014 01:14 am
Very interesting. So how much thrust would be calculated for a right circular cylinder filled half way with a dielectric?

Choose your own dielectric constant and don't worry about can length. The can has a Q value of 50,000 which seems easy.
Is this in reference to Thinker X's last message?

Yes, but I'm not to proud to read a reasonable answer from anyone.
Title: Re: EM Drive Developments
Post by: zen-in on 10/27/2014 12:22 pm
New post by Dr.McCulloch, using two McCulloch formulas:

http://physicsfromtheedge.blogspot.it/2014/10/mihsc-vs-emdrive-updated-table.html


incorporating the superconducting Cannae test
http://web.archive.org/web/20121104025749/http://www.cannae.com/proof-of-concept/design

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC_fig_1.gif)
(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC_fig_2.gif)
(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC.fig3.jpg)
(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC_design_figure42.jpg)

This device is fictional.   No one would build a dewar this way.   A thick metal tube that starts at room temperature can't be immersed in the liquid Helium.  The Helium would just boil off continually.   Also a real Helium dewar would not have the liquid Helium vessel and the liquid Nitrogen vessels separated by a metal wall, as shown in this diagram.   The 72 K temperature difference would boil off the liquid Helium as fast as it was added.   The design of Helium dewars requires sophisticated methods for thermally isolating the liquid Helium from even the smallest sources of heat.  High vacuum chambers and special IR-reflective coatings are used.  The creator of this illustration must be aware of the need for a high vacuum because there is something labeled "turbopump" in the diagram.   However it looks like it is only used to pump out the interior of the device being tested.   This diagram looks like it started out as a cut away figure of a liquid Nitrogen dewar.   There is a large volume surrounding the liquid Nitrogen vessel and contained by the outer wall. In a liquid Nitrogen dewar this volume would be evacuated to a high vacuum to insulate the liquid Nitrogen.   There are too many discrepancies in this diagram.

I have to conclude the author has grossly oversimplified this diagram for reasons only he/she understands or this experiment was never done.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 02:42 pm
The trouble is, it doesn't make any sense.  First of all, even those who admit virtual particles as something other than a cheezy accounting measure (the vast minority of real physicists) know that virtual particles have to be exceedingly short lived, so positing them traversing between an accelerated frame and the horizon is pretty silly on the face of it.  It would be good to look at that in more detail, but certainly the bigger problem with this is that if it is correct, General Relativity and Einstein's Equivalence Principle that GR relies upon, indeed the entire principle of relativity are all incorrect!  We have so much data, that these three are correct that it is on its face, silly to entertain physics like this.  One has to ask, "where do you draw the line" between what is a plausible explanation and what is not?

Does this "theory", explain to us how we have the findings of GR over the decades?  Does it answer how we can have so much experimental validation of Einstein's theories and yet they are wrong?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/27/2014 02:49 pm
This device is fictional.   No one would build a dewar this way.

Couple of random links for dewars:

Buy it now at:

http://www.cryofab.com/products/cmsh_series

http://nmrwiki.org/wiki/index.php?title=Ice_in_my_dewar!_%28Liquid_helium_transport_dewar%29

http://www.kadel.com/liquid-helium-dewars/

The oracle:

http://en.wikipedia.org/wiki/Cryogenic_storage_dewar

Gravity Probe B:

http://einstein.stanford.edu/highlights/hl_100104.html
Title: Re: EM Drive Developments
Post by: RonM on 10/27/2014 03:03 pm
The trouble is, it doesn't make any sense.  First of all, even those who admit virtual particles as something other than a cheezy accounting measure (the vast minority of real physicists) know that virtual particles have to be exceedingly short lived, so positing them traversing between an accelerated frame and the horizon is pretty silly on the face of it.  It would be good to look at that in more detail, but certainly the bigger problem with this is that if it is correct, General Relativity and Einstein's Equivalence Principle that GR relies upon, indeed the entire principle of relativity are all incorrect!  We have so much data, that these three are correct that it is on its face, silly to entertain physics like this.  One has to ask, "where do you draw the line" between what is a plausible explanation and what is not?

Does this "theory", explain to us how we have the findings of GR over the decades?  Does it answer how we can have so much experimental validation of Einstein's theories and yet they are wrong?

That's been my issue with this.

We know that General Relativity and Quantum Theory don't play well with each other, so there must be some new physics or math that we have yet to discover. However, any new physics theory has to incorporate the decades of experimentation that shows the regimes where current theory works. There are scales where GR has not been tested, but may I remind everyone that GR has never failed where it has been tested.

Any new physics will not over turn our very successful modern theories. It will add to them.
Title: Re: EM Drive Developments
Post by: aceshigh on 10/27/2014 03:27 pm
The trouble is, it doesn't make any sense.  First of all, even those who admit virtual particles as something other than a cheezy accounting measure (the vast minority of real physicists) know that virtual particles have to be exceedingly short lived, so positing them traversing between an accelerated frame and the horizon is pretty silly on the face of it.  It would be good to look at that in more detail, but certainly the bigger problem with this is that if it is correct, General Relativity and Einstein's Equivalence Principle that GR relies upon, indeed the entire principle of relativity are all incorrect!  We have so much data, that these three are correct that it is on its face, silly to entertain physics like this.  One has to ask, "where do you draw the line" between what is a plausible explanation and what is not?

Does this "theory", explain to us how we have the findings of GR over the decades?  Does it answer how we can have so much experimental validation of Einstein's theories and yet they are wrong?


Ron, I have no idea what I am talking about here, so please, correct me (because I know there will be reasoning errors here, but I am posting anyway exactly to see your answer so I can better understand what´s going on):

"know that virtual particles have to be exceedingly short lived, so positing them traversing between an accelerated frame and the horizon is pretty silly on the face of it"

doesn´t ME/Woodward Theory posit gravity waves or particles, whatever, flying backwards in time, so as to answer the question of inertia being caused by the mass of the distant universe acting instantly on anything?

if that's the case with gravity waves (or whatever else you are going to correct me), can´t a similar principle go on with these virtual particles?
Title: Re: EM Drive Developments
Post by: RonM on 10/27/2014 04:04 pm
doesn´t ME/Woodward Theory posit gravity waves or particles, whatever, flying backwards in time, so as to answer the question of inertia being caused by the mass of the distant universe acting instantly on anything?

That's a pretty bold concept. I'm not saying it's wrong, but where is the experimental evidence that they are correct?

Causality is very important to physics. Basically, the cause comes before the effect. Weak causality would include information traveling backwards in time at the speed of light resulting in the effect at the same time as the cause. It's an interesting concept, but there is no evidence that the universe works that way. Basically, there is no evidence ME works.

I'm not picking on ME or Woodward. String Theory is tossed about as if it was true, even though it also has no experimental evidence to back it up. I guess it is just more popular.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 04:42 pm
The trouble is, it doesn't make any sense.  First of all, even those who admit virtual particles as something other than a cheezy accounting measure (the vast minority of real physicists) know that virtual particles have to be exceedingly short lived, so positing them traversing between an accelerated frame and the horizon is pretty silly on the face of it.  It would be good to look at that in more detail, but certainly the bigger problem with this is that if it is correct, General Relativity and Einstein's Equivalence Principle that GR relies upon, indeed the entire principle of relativity are all incorrect!  We have so much data, that these three are correct that it is on its face, silly to entertain physics like this.  One has to ask, "where do you draw the line" between what is a plausible explanation and what is not?

Does this "theory", explain to us how we have the findings of GR over the decades?  Does it answer how we can have so much experimental validation of Einstein's theories and yet they are wrong?


Ron, I have no idea what I am talking about here, so please, correct me (because I know there will be reasoning errors here, but I am posting anyway exactly to see your answer so I can better understand what´s going on):

"know that virtual particles have to be exceedingly short lived, so positing them traversing between an accelerated frame and the horizon is pretty silly on the face of it"

doesn´t ME/Woodward Theory posit gravity waves or particles, whatever, flying backwards in time, so as to answer the question of inertia being caused by the mass of the distant universe acting instantly on anything?

if that's the case with gravity waves (or whatever else you are going to correct me), can´t a similar principle go on with these virtual particles?
You're here referring to Woodward's use of the Wheeler Feynman Absorber theory in his M-E theory.  There's no virtual particle that mediates the transfer in either Absorber theory nor in Woodward's theory.  It's a field phenomena that usually is taken only in its forward in time sense, but Wheeler and Feynman noted that this is an arbitrary choice, and used both in the absorber theory. 

http://en.wikipedia.org/wiki/Wheeler–Feynman_absorber_theory

(Note too how this relates to Cramer's Transactional Interpretation in Quantum Mechanics, noted in the wiki link; which relies similarly.  Both are following Wheeler and Feynman.)

Woodward merely adopted it for inertia.  This is completely different than referring to any virtual particles.

Virtual particles are not real particles.  They are an accounting mechanism that was created (by Feynman I believe--who did not believe any of this silly nonsense of today about them) quite apart from any proposal that they should actually exist.  In the case of this theory above, in order to exist for the duration necessary to reach the horizon, they would have to have very long lifespans and the theory posits they cannot be so long lived and yet be virtual.  They would have to be real.  Likewise the real trouble--virtual particles cannot have gravitational mass, or their mass added to the universe would not only cause it to immediately collapse, but it would never have expanded to begin with.  However, to make virtual particles useful in any sense, people want to pretend they have inertial mass.  All of the ZPF, QVF and now this scheme, promote this view that the inertial and gravitational mass of virtual particles can be different.  Yet Einstein clearly shows us they cannot be different--EVER.  This is what EEP is all about.  If it is wrong, GR is wrong and all of modern gravity physics with it.

I'm betting on Einstein.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 04:48 pm
doesn´t ME/Woodward Theory posit gravity waves or particles, whatever, flying backwards in time, so as to answer the question of inertia being caused by the mass of the distant universe acting instantly on anything?

That's a pretty bold concept. I'm not saying it's wrong, but where is the experimental evidence that they are correct?
That's precisely the kind of question we philosophers of science like to see.  :-)

The only evidence comes from the lab at Fullerton.  If one can look at Woodward's setup and posit another explanation for the thrusts he's had there for many years, then you can say there is no evidence.  However, lacking an explanation for the thrusts other than M-E theory, then all that thrust data is evidence for his proposed use of absorber theory.  M-E theory is not contingent upon absorber theory, but it is the most viable explanation for how the pieces of the puzzle fit together at this time.  If you're curious, I highly recommend the book in which you'll find the most comprehensive treatment of theory, access to all the peer reviewed and conference papers of about 20 years and details of the experimental setup at Fullerton upon which surely this stuff all rests.  Science starts with observation.

http://www.amazon.com/Making-Starships-Stargates-Interstellar-Exploration/dp/1461456223
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/27/2014 05:06 pm
Homebrew parts:

http://www.freescale.com/webapp/sps/site/overview.jsp?code=RF_HEATING_PG&tid=vanRFheating
Title: Re: EM Drive Developments
Post by: aceshigh on 10/27/2014 05:10 pm
so the basic difference is that one is a field phenomena and the other would be a particle phenomena, and while we can accept travelling back in time for field phenomena, we can´t accept it for particles, which would disprove these virtual particles as anything other than what they really are: virtual, to make mathematical analysis simpler?

am I on track? Thanks
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 05:19 pm
That's a little off.  I suggest try to read the English bits on the wiki page linked above.  The essential difference is that Woodward never even makes reference to virtual particles.  His theory does not require them at all.  In fact, in his book he explains that we don't really need them for anything.  Contrary to popular notions floating around in the advanced propulsion ZPF and QVF camps (and now this new one) virtual particles are not required to explain things like Casimir Effect.  There are perfectly reasonable explanations for CA that do not require virtual particles, but you would never get that listening to anyone who believes this wonky physics.  And I would just note to you, the percent of people who believe in treating virtual particles this way is vanishingly small.  That's why Sean Carroll at Cal Tech called this stuff "BuII$hit".
Title: Re: EM Drive Developments
Post by: Rodal on 10/27/2014 05:46 pm
Table comparing Shawyer and McCulloch's predictions with measurements

c= 299705000 m/s (speed of light in air)

lengths in meter
rfFrequency in 1/second (microwave frequency during test)
power in watts
force in milliNewtons
force per PowerInput in milliNewtons/kW

Note: SmallDiameter for Shawyer's EM Drives obtained from his reported ShawyerDesignFactor .

predicted force (either Shawyer or McCulloch) followed (in parenthesis) by ratio of prediction divided by measurement

ShawyerForce = (2 * PowerInput * Q / c ) * ShawyerDesignFactor

McCullochForce1 = ( PowerInput * Q / rfFrequency ) * ((1/smallDiameter) - (1/bigDiameter))

McCullochForce2 = ( PowerInput * Q / c ) * ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))


ShawyerForcePerPowerInput = (2 * Q / c ) * ShawyerDesignFactor
McCullochForce1PerPowerInput = (Q / rfFrequency ) * ((1/smallDiameter) - (1/bigDiameter))
McCullochForce2PerPowerInput = (Q / c ) * ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))


Force/PowerInput of a Photon Rocket = 1 / c

Force/PowerInput ratios divided by the Force/PowerInput of a Photon Rocket, divided by Q are:

Shawyer/PhtnRckt/Q = 2 * ShawyerDesignFactor
McCulloch1/PhtnRckt/Q = (c / rfFrequency ) * ((1/smallDiameter) - (1/bigDiameter))
McCulloch2/PhtnRckt/Q = ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))








(* Shawyer Experimental *)
rfFrequency=2.45*10^9;
cavityLength=0.156;
bigDiameter=0.16;
smallDiameter=0.127546;
ShawyerDesignFactor = 0.497

power =  850   
Q = 5900

measured force = 16
ShawyerForce = 16.63
McCullochForce1 = 3.26
McCullochForce2 = 4.15

measured ForcePerPowerInput = 18.82
ShawyerForcePerPowerInput = 19.57
McCullochForce1PerPowerInput = 3.83
McCullochForce2PerPowerInput =4.88

Shawyer/PhtnRckt/Q = 0.9940
McCulloch1/PhtnRckt/Q = 0.1945
McCulloch2/PhtnRckt/Q = 0.2481



(* Shawyer Demo *)
rfFrequency=2.45*10^9;
cavityLength=0.345;
bigDiameter=0.28;
smallDiameter= 0.128853
ShawyerDesignFactor  = 0.844

power =  421 to 1200
Q = 45000

(measured force = 102.30 milliNewtons only reported for  421 watts, 243 milliNewtons/kW )

measured ForcePerPowerInput = 80 to 243
ShawyerForcePerPowerInput = 253.4
McCullochForce1PerPowerInput = 76.95
McCullochForce2PerPowerInput = 217.0

Shawyer/PhtnRckt/Q = 1.688
McCulloch1/PhtnRckt/Q = 0.5125
McCulloch2/PhtnRckt/Q = 1.445



All Brady cases have the following dimensions:

cavityLength=0.332;
bigDiameter=0.397;
smallDiameter=0.244;


(* Brady a *)
rfFrequency=1.9326*10^9;
ShawyerDesignFactor  =0.311969

power =   16.9 
Q = 7320

measured force =  0.0912
ShawyerForce = 0.2575
McCullochForce1 = 0.1011
McCullochForce2 =0.2164

measured ForcePerPowerInput = 5.396
ShawyerForcePerPowerInput = 15.24
McCullochForce1PerPowerInput = 5.982
McCullochForce2PerPowerInput =12.81

Shawyer/PhtnRckt/Q = 0.6239
McCulloch1/PhtnRckt/Q = 0.2449
McCulloch2/PhtnRckt/Q = 0.524384

(* Brady b *)   STATISTICAL OUTLIER
rfFrequency=1.9367*10^9;
ShawyerDesignFactor  = 0.310959

power = 16.7
Q =  18100

measured force = 0.0501
ShawyerForce = 0.6272
McCullochForce1 = 0.2465
McCullochForce2 =0.5289

measured ForcePerPowerInput = 3.000
ShawyerForcePerPowerInput = 37.56
McCullochForce1PerPowerInput = 14.76
McCullochForce2PerPowerInput =31.67

Shawyer/PhtnRckt/Q = 0.6219
McCulloch1/PhtnRckt/Q = 0.2444
McCulloch2/PhtnRckt/Q = 0.5244


  (* Brady c *)
rfFrequency = 1.8804*10^9;
ShawyerDesignFactor  = 0.325498

power = 2.6
Q = 22000

measured force = 0.05541
ShawyerForce = 0.1242
McCullochForce1 = 0.04805
McCullochForce2 = 0.1001

measured ForcePerPowerInput = 21.31
ShawyerForcePerPowerInput = 47.79
McCullochForce1PerPowerInput = 18.48
McCullochForce2PerPowerInput = 38.49

Shawyer/PhtnRckt/Q = 0.6510
McCulloch1/PhtnRckt/Q = 0.2517
McCulloch2/PhtnRckt/Q = 0.5244

Title: Re: EM Drive Developments
Post by: Rodal on 10/27/2014 07:34 pm
**** Re-posting since people are writing comments about the quantum vacuum plasma again ****

Shawyer gave us his equations to predict force .

I have not found the actual equation that Dr. White at NASA uses to predict forces

I have seen Dr. White's derivation for the electron mass, Bohr radius, gravitational coupling constant, his MHD plasma analogy, and Microsoft Excel spreadsheet predictions (see attached).  But I don't know what actual equations he used in that Microsoft Excel spreadsheet to make the prediction.

Can anyone please provide Dr. White's equation to predict the thrust force from his electron-positron virtual particle quantum vacuum theory?

Seriously, we have numerical comparisons of Shawyer's and McCulloch's predictions with experiments (see :  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1277322#msg1277322  ).

Some people have even spent time writing a Wikipedia article on "Quantum Vacuum Plasma Thruster" http://en.wikipedia.org/wiki/Quantum_vacuum_plasma_thruster but have failed to provide an equation to calculate the thrust force from such a "Quantum Vacuum Plasma Thruster."

This is an appeal to also include Dr. White's quantum-vacuum-plasma thrust-force-prediction equations.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 07:45 pm
Seriously, we have numerical comparisons of Shawyer's and McCulloch's predictions with experiments. . .
I'm sure you're well meaning in this line of reasoning, but I would just point out to you, as I have to Dr. White on a dozen similar occasions, that this is mere rhetoric and is unhelpful in the extreme in doing science.  Which supposed "prediction" is closest to the claims is irrelevant when it comes to which is likely correct, and thinking this way leads people into thinking errors that endure over time.  This is pure fallacy.  It is however worse, as it is fallacy mixed with lack of integrity, when people are claiming to be making "predictions' when in fact these come AFTER THE DATA.  When these calculations come after the data, they are most assuredly NOT predictions, which is just precisely what we have here.

We are straining hard on the edge of pathological science here, especially when I have made this correction to Dr. White on so many occasions and he continues to mislead his audience through false claims of prediction.  Likewise, Dr. McCulloch did not make any predictions so far as I'm aware.  Were there some numbers published by him before the actual work at NASA was taken to conference?
Title: Re: EM Drive Developments
Post by: Rodal on 10/27/2014 08:02 pm
The equations of Quantum Mechanics were developed mathematically (mainly by Heisenberg and Schrodinger) after the quantum mechanics experiments could not be explained by classical physics.  Ditto for the formalization of Quantum Mechanics by John von Neuman. Ditto for Maxwell's equations.  Ditto for Newton's equations to explain the orbits of celestial bodies.  Ditto for countless other examples.

Neither John von Neuman nor Feynman (quoted above concerning virtual particles) engaged in the philosophy of science (actually John von Neuman warned against it, so did Bohr, and so did Victor Weisskopf as I recall from his lectures).

I'm sure you are well meaning as well, but this is not a philosophy of science forum (and by this I do not state any opinion on the philosophy of science), it is mainly a practical applications forum.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 08:12 pm
Yes well, I understand your point but it remains that your practical application is incorrect.  It does not matter which explanation is closest to the observed value, especially when the calculations come after the data is received.  This is simple scientific method any engineer should be aware of.  How close a wrong answer is to the observed value forms no correlation whatsoever with any probability of its veracity, and asking people to think this way is inviting them to form a thinking error.  I'm perhaps overly sensitive to this error because Dr. White has on many occasions compare his model to others in this way, inviting people to form this invalid conclusion.  And it is easy to see how this happens.  Fallacies are tricky things.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/27/2014 08:19 pm
As I see it science is done in both ways...
You have a theory that you want to test against reality. You do experiments to confirm or deny the theory.
Or
You have an experimental result that can't be explained by current theory. You postulate a new theory to explain the experiment.

Rinse and repeat.

That is what I see going on here. Science at it's best.
Title: Re: EM Drive Developments
Post by: aero on 10/27/2014 08:22 pm
Yes well, I understand your point but it remains that your practical application is incorrect.  It does not matter which explanation is closest to the observed value, especially when the calculations come after the data is received.  This is simple scientific method any engineer should be aware of.  How close a wrong answer is to the observed value forms no correlation whatsoever with any probability of its veracity, and asking people to think this way is inviting them to form a thinking error.  I'm perhaps overly sensitive to this error because Dr. White has on many occasions compare his model to others in this way, inviting people to form this invalid conclusion.  And it is easy to see how this happens.  Fallacies are tricky things.

I see our objective as "curve fitting" the data. The more accurate model will fit the data points more accurately. It would be great if we had a mathematical relationship of exactly the right set of parameters. But we don't.

Once we hypothesize the best model that the limited data can provide, future data will serve to confirm or disprove the hypothesis. And that is where scientific objectivity will be paramount.
Title: Re: EM Drive Developments
Post by: aero on 10/27/2014 08:30 pm
In addition to the above, since even our most accurate model is all over the place, what, I wonder, are the missing parameters influencing the measured force? Are they all experimental error or do they have to do with shades of polarization? Something else, or do we really have them all but not the right model?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 08:32 pm
The more accurate model will fit the data points more accurately.
This is the trouble, as this above is not true.  Given at least one of the half dozen contenders to explain the lab findings at Eagleworks is correct (which we don't know), there is no reason to suppose that explanation would form the basis of a calculation that is closer to the lab data than those made by other models.  When you don't know what is wrong with a model, or with the setup, or a host of other things, you cannot make these kinds of judgements.  The thing to do is certainly to withhold judgement.  There is no doubt that this above is a fallacy--an example of flawed logic--and Dr. White has deliberately exploited this sort of thing in the past in order to get funding.  I kid you not, you should never play this game.  It is wrong start to finish and has nothing to do with science.  This is rhetoric.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/27/2014 08:45 pm
The more accurate model will fit the data points more accurately.
This is the trouble, as this above is not true.  Given at least one of the half dozen contenders to explain the lab findings at Eagleworks is correct (which we don't know), there is no reason to suppose that explanation would form the basis of a calculation that is closer to the lab data than those made by other models.  When you don't know what is wrong with a model, or with the setup, or a host of other things, you cannot make these kinds of judgements.  The thing to do is certainly to withhold judgement.  There is no doubt that this above is a fallacy--an example of flawed logic--and Dr. White has deliberately exploited this sort of thing in the past in order to get funding.  I kid you not, you should never play this game.  It is wrong start to finish and has nothing to do with science.  This is rhetoric.
So you are stating that Dr White is a complete fraud and a liar?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 09:07 pm
Please don't shoot the messenger.  I'm simply saying that although there is a fantastical amount of great value here especially as regards Dr. Rodel's analysis to this point, this data is from a conference paper, written to gain funding.  It is not a statistically valid sample.  Just look at the error bars had someone chosen to make some.  With what was it, just 9 data points? one forms a conclusion, but that conclusion cannot be statistically valid.  The error in the readings is far more than the spread between the post-dictions that are being compared to them.  It could be one of the nine readings is correct and the others are marred by error, or it could be none of them is correct and all of the data reflects some hidden or loose variable.  And these other labs haven't put out data that we can look at.  So how then can we compare them?

I have said what I have said about Sonny's method on several occasions and the point here is to note, that this is a conference paper, with no statistically valid data, and so any comparison is doomed to mislead at best, and intentionally mislead at worst.  There's nothing wrong with Dr. Rodel's method so far as I can see, save that he's straining to do a real analysis of something less than real data.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/27/2014 09:15 pm
Please don't shoot the messenger.  I'm simply saying that although there is a fantastical amount of great value here especially as regards Dr. Rodel's analysis to this point, this data is from a conference paper, written to gain funding.  It is not a statistically valid sample.  Just look at the error bars had someone chosen to make some.  With what was it, just 9 data points? one forms a conclusion, but that conclusion cannot be statistically valid.  The error in the readings is far more than the post-dictions that are being compared to them.  It could be one of the nine readings is correct and the others are marred by error, or it could be none of them is correct and all of the data reflects some hidden or loose variable.  And these other labs haven't put out data that we can look at.  So how then can we compare them?

I have said what I have said about Sonny's method on several occasions and the point here is to note, that this is a conference paper, with no statistically valid data, and so any comparison is doomed to mislead at best, and intentionally mislead at worst.  There's nothing wrong with Dr. Rodel's method so far as I can see, save that he's straining to do a real analysis of something less than real data.
You make valid points about error-bars and the paucity of data points.
However you persist in your claim that it is not 'real' data and thus fabricated.
Please stop this nonsense. Question everything by all means.
Title: Re: EM Drive Developments
Post by: aero on 10/27/2014 09:16 pm
The more accurate model will fit the data points more accurately.
This is the trouble, as this above is not true.  Given at least one of the half dozen contenders to explain the lab findings at Eagleworks is correct (which we don't know), there is no reason to suppose that explanation would form the basis of a calculation that is closer to the lab data than those made by other models.  When you don't know what is wrong with a model, or with the setup, or a host of other things, you cannot make these kinds of judgements.  The thing to do is certainly to withhold judgement.  There is no doubt that this above is a fallacy--an example of flawed logic--and Dr. White has deliberately exploited this sort of thing in the past in order to get funding.  I kid you not, you should never play this game.  It is wrong start to finish and has nothing to do with science.  This is rhetoric.
So you are stating that Dr White is a complete fraud and a liar?

No - no. I believe the correct choice is to discard the top 6 models and start with a clean sheet. But since we don't have 6 models, we can't throw them out.

@Dr. Rodal - Do you have current regression analysis for all the models so we will know which to discard.

@ Frobnicat - Do you have some models we can discard, or are you still awaiting new dimensions?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 09:31 pm
Please don't shoot the messenger.  I'm simply saying that although there is a fantastical amount of great value here especially as regards Dr. Rodel's analysis to this point, this data is from a conference paper, written to gain funding.  It is not a statistically valid sample.  Just look at the error bars had someone chosen to make some.  With what was it, just 9 data points? one forms a conclusion, but that conclusion cannot be statistically valid.  The error in the readings is far more than the post-dictions that are being compared to them.  It could be one of the nine readings is correct and the others are marred by error, or it could be none of them is correct and all of the data reflects some hidden or loose variable.  And these other labs haven't put out data that we can look at.  So how then can we compare them?

I have said what I have said about Sonny's method on several occasions and the point here is to note, that this is a conference paper, with no statistically valid data, and so any comparison is doomed to mislead at best, and intentionally mislead at worst.  There's nothing wrong with Dr. Rodel's method so far as I can see, save that he's straining to do a real analysis of something less than real data.
You make valid points about error-bars and the paucity of data points.
However you persist in your claim that it is not 'real' data and thus fabricated.
Please stop this nonsense. Question everything by all means.
I'm not suggesting Sonny fabricated this data.  In fact though I cannot say he would never do such a thing, I know Paul March would not.  That's not the issue.  The issue is, that with so few data points, with so much error demonstrated, and no reason to draw a line through the spread of the data the way one hopes they're justified to do ONLY when one has a statistically valid sample, there is no way to get to there from here.  You can't apply these excellent tools Dr. Rodel has been using and expect a real answer when you haven't identified possible sources of error, looked at the error bars, formulated why any particular model is appropriate to the data or not, etc.

Just take one example from Eagle.  The QVF model predicts thrust from DC, and there has been no thrust observed with DC to date.  The QVF model predicted a warp signature from the interferometry experiments and none was observed.  I can therefore see no experimental reasons to suppose the QVF conjecture is even in the running as an explanation for this thrust.  So how can we compare it quantitatively, after the fact of the data?  We simply cannot.  Sometimes that's what science says, "I don't know and I'm not going to guess.".

And BTW, one wants to ask; what does Dr. McCulloch's model say about DC thrust?  I haven't invested myself to understand that model, but with as much in common as it has with ZPF theory, does it predict thrust from DC?  If not, why not?  That's the sort of thing one can ask with this meager data.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/27/2014 09:33 pm
Please don't shoot the messenger.  I'm simply saying that although there is a fantastical amount of great value here especially as regards Dr. Rodel's analysis to this point, this data is from a conference paper, written to gain funding.  It is not a statistically valid sample.  Just look at the error bars had someone chosen to make some.  With what was it, just 9 data points? one forms a conclusion, but that conclusion cannot be statistically valid.  The error in the readings is far more than the post-dictions that are being compared to them.  It could be one of the nine readings is correct and the others are marred by error, or it could be none of them is correct and all of the data reflects some hidden or loose variable.  And these other labs haven't put out data that we can look at.  So how then can we compare them?

I have said what I have said about Sonny's method on several occasions and the point here is to note, that this is a conference paper, with no statistically valid data, and so any comparison is doomed to mislead at best, and intentionally mislead at worst.  There's nothing wrong with Dr. Rodel's method so far as I can see, save that he's straining to do a real analysis of something less than real data.
You make valid points about error-bars and the paucity of data points.
However you persist in your claim that it is not 'real' data and thus fabricated.
Please stop this nonsense. Question everything by all means.
I'm not suggesting Sonny fabricated this data.  In fact though I cannot say he would never do such a thing, I know Paul March would not.  That's not the issue.  The issue is, that with so few data points, with so much error demonstrated, and no reason to draw a line through the spread of the data the way one hopes they're justified to do ONLY when one has a statistically valid sample, there is no way to get to there from here.  You can't apply these excellent tools Dr. Rodel has been using and expect a real answer when you haven't identified possible sources of error, looked at the error bars, formulated why any particular model is appropriate to the data or not, etc.

Just take one example from Eagle.  The QVF model predicts thrust from DC, and there has been no thrust observed with DC to date.  The QVF model predicted a warp signature from the interferometry experiments and none was observed.  I can therefore see no experimental reasons to suppose the QVF conjecture is even in the running as an explanation for this thrust.  So how can we compare it quantitatively, after the fact of the data?  We simply cannot.  Sometimes that's what science says, "I don't know and I'm not going to guess.".
Excellent. Thanks Ron.
Title: Re: EM Drive Developments
Post by: Rodal on 10/27/2014 09:41 pm
....
Just take one example from Eagle.  The QVF model predicts thrust from DC, and there has been no thrust observed with DC to date.  The QVF model predicted a warp signature from the interferometry experiments and none was observed.  I can therefore see no experimental reasons to suppose the QVF conjecture is even in the running as an explanation for this thrust.  ...
Not arguing with that.  Take a look at this message :  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1276802#msg1276802 where I show that Dr. White's published formulation has his "Quantum Vacuum Plasma" force directed radially rather than axially (hence he has the predicted QV force perpendicular to the measured force vector).

Still, since he has published predictions I'm curious as to the actual formulas he uses, because Physics's language is mathematics.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/27/2014 09:54 pm
I am really the last person to check the math, but I will note to you, I have indeed corrected Sonny's math in the past.  I was home sick and tanked up on cough medicine, and so made the dubious choice to bludgeon my way through Sonny's derivation of his model back in 2007, and what I found was he had transposed a factor for an exponent and all his results reflected this.  And of course at that time he had been doing just as you're doing above, saying his model more accurately predicted the thrusts from Jim's lab than Jim's theory does. 

Well in fact, Woodward has never made any thrust magnitude predictions because he knows how how complex and uncertain the trouble with loose variables is.  It was Andrew Palfreyman who had slapped together an algebraic relation he thought would do the subject justice.  That's what Sonny was using to compare his model to Woodward's theory.  It was years later Woodward went to look at Andrew's relation and found the mistakes in it.  So really Sonny had no right to be comparing Woodward's theory base upon someone else's misinformed algebra.  (And I think some of this is in the book.)  This was all just rhetoric for seeking funding for Eagleworks.

I personally believe that all of this work by its nature, lends itself to qualitative predictions only.  There are just too many things we don't know for example, about the dielectrics used.  They have never been properly characterized.  Predictions there either need to be qualitative, we should have thrust/we should not have thrust; or part of a parametric study where one variable in a system is changed and one looks for scaling with voltage for example.  If you have a voltage-thrust relation and can vary the voltage to look for a quadratic relation for example, that much you can do without identifying all the other loose variables.  That's what parametric studies are for.

Quote
Take a look at this message :  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1276802#msg1276802 where I show that Dr. White's published formulation has his "Quantum Vacuum Plasma" force directed radially rather than axially (hence he has the predicted QV force perpendicular to the measured force vector).

Yes, I saw that back when you posted it.  Did you get word back from Eagle on this?  I'm asking because when I showed Sonny the error in his derivation, his first response was to attack me "who is this guy?" and his second response was to claim the error had crept in when the spreadsheet had been transmitted from one person to another--which was just the most ludicrous thing I'd ever heard.  And this is the kind of stuff Sonny has been doing for as long as I've known him.

And I hate to say this, but one wonders whether the fault isn't in some part that of Rice University, where most of JSC's folks go for their quick PhD's.  I have never read Sonny's doctoral thesis, but reportedly in his thesis on plasma physics he "proves" that there is no lightning on Venus.  As any budding high school philosopher will tell you, one can't prove a negative, so this has always been the source of some alarm.  It's sloppy thinking we ought not expect at that level.
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/27/2014 10:42 pm
I'm not sure why you're beating around the bush so much, Ron; you don't have to be discrete. You find the data being supplied by Sonny White and NASA Eagleworks suspect - the former because the guy is a quack who does bad science, the latter because they need funding.
Title: Re: EM Drive Developments
Post by: Rodal on 10/27/2014 10:45 pm
I suggest we should concentrate on the experiments, math and physics, and any discussions be strictly restricted to what are the consequences of his/her published theories but never on the person itself.
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/27/2014 11:07 pm
I suggest we should concentrate on the experiments, math and physics, and any discussions be strictly restricted to what are the consequences of his/her published theories but never on the person itself.

How do you separate the two, without discarding the conversation topic, when one's hypothesis on the origins of the data is "they're making it up?"
Title: Re: EM Drive Developments
Post by: Rodal on 10/27/2014 11:19 pm
I suggest we should concentrate on the experiments, math and physics, and any discussions be strictly restricted to what are the consequences of his/her published theories but never on the person itself.

How do you separate the two, without discarding the conversation topic, when one's hypothesis on the origins of the data is "they're making it up?"
1) I think we should not consider that the data was deliberately "made up", but rather the result of experimentation problems due to the fact that the resonant response is an extremely nonlinear function of frequency

2) For example,  Eagleworks reported only 3 different test results for the truncated cone.  One of these test results is an outlier, practically at the same frequency (0.2% difference) as the first test, described as having exactly the same mode shape (TM211), and at approximately the same input power (1% difference) yet the response is only 54% of the former observed force.    The data, as pointed out by R. Ludwick rather indicates big experimental problems with their equipment being able to tune to a resonant frequency and for the frequency to stay in the narrow resonant bandwidth (due to large Q).  They also had very significant problems with their drifting baseline.
Title: Re: EM Drive Developments
Post by: tchernik on 10/27/2014 11:24 pm
Hello NSF posters. I have been following this forum and topic since some time ago. Great forum and discussions!

I just wanted to add that I also prefer if the discussion sticks to the scientific facts and theories proving or disproving the claims made by H. White. Telling how horrible a person Harold White really is doesn't add anything new, and it's even damaging to clarifying the facts, because it simply says: "he's a quack! don't discuss him".

Also, I don't have direct evidence of how a horrible person he really is, except the word of the wronged/offended persons.

I assume they talk in good faith, but again, I also assume H. White and his co-author do.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/27/2014 11:41 pm
Hello NSF posters. I have been following this forum and topic since some time ago. Great forum and discussions!

I just wanted to add that I also prefer if the discussion sticks to the scientific facts and theories proving or disproving the claims made by H. White. Telling how horrible a person Harold White really is doesn't add anything new, and it's even damaging to clarifying the facts, because it simply says: "he's a quack! don't discuss him".

Also, I don't have direct evidence of how a horrible person he really is, except the word of the wronged/offended persons.

I assume they talk in good faith, but again, I also assume H. White and his co-author do.
Welcome good sir!
I agree with you.
Now if we could just pin down this pesky anomalous thrust...
Title: Re: EM Drive Developments
Post by: frobnicat on 10/27/2014 11:45 pm
Hello NSF posters. I have been following this forum and topic since some time ago. Great forum and discussions!

I just wanted to add that I also prefer if the discussion sticks to the scientific facts and theories proving or disproving the claims made by H. White. Telling how horrible a person Harold White really is doesn't add anything new, and it's even damaging to clarifying the facts, because it simply says: "he's a quack! don't discuss him".

Also, I don't have direct evidence of how a horrible person he really is, except the word of the wronged/offended persons.

I assume they talk in good faith, but again, I also assume H. White and his co-author do.

Welcome tchernik

Thing is, there is many many places where people are saying "all those people working on propellantless propulsion are quacks. Period. End of discussion". Or just even not caring saying anything at all : implicit dismissal. There is also a number of places where supporters can congratulate their champion and talking bad on other champions. A few places have we seen where sceptics have invested time to do further study in more detail why they think this is all a dream (I'm thinking of Greg Egan's elegant analytical study of resonance in conical cavity).

This thread on this forum is apparently the one place where interested people can do a real effort of understanding with an open mind, where it is possible to express sceptical views (on rational arguments), where it is possible to express interest in ground breaking theories (with ideas stated clearly enough to be falsifiable hopefully), where it is possible to argue on experimenters methodologies (politely, hopefully), and where it is also possible to try to find classical explanations to the results (without too much hand-waving hopefully).

Please, please, keep this place honest, open, and constructive by all means.
And not locked.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/27/2014 11:54 pm
...  I'm simply saying that although there is a fantastical amount of great value here especially as regards Dr. Rodel's analysis to this point, this data is from a conference paper, written to gain funding.  It is not a statistically valid sample.....  And these other labs haven't put out data that we can look at.  So how then can we compare them?

I have said what I have said about Sonny's method on several occasions and the point here is to note, that this is a conference paper, with no statistically valid data, and so any comparison is doomed to mislead at best, ...  There's nothing wrong with Dr. Rodel's method so far as I can see, save that he's straining to do a real analysis of something less than real data.

You make valid points about error-bars and the paucity of data points.

However you persist in your claim that it is not 'real' data and thus fabricated.
Please stop this nonsense. Question everything by all means.

Sticking with, as I tend to do, with the best of what people write and not the worst, I think it is important to restate that the data is not being considered as fabricated by the competent analysts here.

There are not enough data points, based on what is believed by consensus to be a lousy experimental protocol, which is supported by poorly written and inconsistent theory.

I believe that Jose is teasing out what he can of substance from the data, but it is my personal opinion that he will fail to discover anything of merit, because there's simply not enough to go on, unless there is a greater sharing of information from the collectors of the data.  And that does not seem to be forthcoming.

Funding motives for research are well understood by the community.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/27/2014 11:58 pm
Please, please, keep this place honest, open, and constructive by all means.

Good job, Frob.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 10/28/2014 12:04 am
Say we had an optimised on the ground setup that produced x Newtons of thrust.
How would we translate that experiment to the ISS? Obviously it would be carried out in vacuum, but how would we measure thrust (if any?)
Let it free float and calculate acceleration? How would the experiment be constrained etc... Power supply (batteries) on the experiment or tethered for power/data?
Title: EM Drive Developments
Post by: Star One on 10/28/2014 12:06 am
Wouldn't it be better to wait until you get more experimental information from those actually working in this area, it seems like there isn't enough data out there in the public domain at the moment to form a coherent answer to your questions?

From what I can remember aren't EagleWorks supposed to be doing more work on this by now and if so it maybe the case that there will be no more data published until say next year.
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/28/2014 12:07 am
Wouldn't it be better to wait until you get more experimental information from those actually working in this area, it seems like there isn't enough data out there in the public domain at the moment to form a coherent answer to your questions?

I'm with you on that. New data can't come soon enough.

Do we know when other institutions are expecting to perform their tests?
Title: EM Drive Developments
Post by: Star One on 10/28/2014 12:10 am
Wouldn't it be better to wait until you get more experimental information from those actually working in this area, it seems like there isn't enough data out there in the public domain at the moment to form a coherent answer to your questions?

I'm with you on that. New data can't come soon enough.

Not to be rude but it looks like at the moment a lot of you are banging your heads on a brick wall because there isn't enough data out there to move towards either verifying or disproving these devices.

As to your other question I am sure they made some mention of testing outside of EagleWorks, can anyone verify this?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/28/2014 12:12 am
The more accurate model will fit the data points more accurately.
This is the trouble, as this above is not true.  Given at least one of the half dozen contenders to explain the lab findings at Eagleworks is correct (which we don't know), there is no reason to suppose that explanation would form the basis of a calculation that is closer to the lab data than those made by other models.  When you don't know what is wrong with a model, or with the setup, or a host of other things, you cannot make these kinds of judgements.  The thing to do is certainly to withhold judgement.  There is no doubt that this above is a fallacy--an example of flawed logic--and Dr. White has deliberately exploited this sort of thing in the past in order to get funding.  I kid you not, you should never play this game.  It is wrong start to finish and has nothing to do with science.  This is rhetoric.
So you are stating that Dr White is a complete fraud and a liar?

No - no. I believe the correct choice is to discard the top 6 models and start with a clean sheet. But since we don't have 6 models, we can't throw them out.

@Dr. Rodal - Do you have current regression analysis for all the models so we will know which to discard.

@ Frobnicat - Do you have some models we can discard, or are you still awaiting new dimensions?

Discard ? I can throw in "theoretically agnostic" reasonably fitting models a dime a dozen. I think Ron makes a point about the sparse amount of "free floating" data so far, and hence the limits of fitting the data. If dr White shows "theoretically predicted values" in his presentations but has no (or refuse to communicate) equations he uses then clearly this is not science at its best. On the other hand Mc Culloch has stated an hypothesis (I don't get it) and derived and published an equation. Even if the hypothesis is false, the equation he gives scores well amongst a lot of others. Phenomenological models are not mere rhetoric. If it is predictive remains to be seen with later experiments... but at least it's published. If Mc Culloch needs to changes equation at each new experiment while standing on hypothesis but adding fudge factors, then and only then it becomes pathological science.

Sorry, just wanted to answer : yes I'm waiting for dimensions and relevant parameters to settle to do further phenomenological regressions. I don't know if it will prove decisive, but it might.
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 12:30 am
...
Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code.  I'll be back with the correct result
Title: Re: EM Drive Developments
Post by: frobnicat on 10/28/2014 12:31 am

OK I run in my inverted torsional pendulum model in Mathematica (with coupled nonlinear equations) the decaying exponential rises of the form 

Fb(t)=80 microNewtons*(1-exp(-t/tau))

and I can firmly state that any tau < 7 sec produces a pendulum response that is negligibly different from tau =0 (an impulse response).  Any tau < 7 sec produces a response that is practically the same as an impulsive response.

That was my impression. Would you share the insides of your input/output black box ? I don't have mathematica (and wouldn't know how to use it efficiently), any chance this model of coupled nonlinear equations would be relatively easy to convert to imperative programming function (iterative form) ?

I'm thinking of a regression scheme (hill climbing or simulated annealing, or genetic algorithm if needed) to reconstruct the signal of interest Fb(t) from the observed Obs(t). This is brute force (again). Maybe inverting a transfer function would be more elegant. But I like numerical bulldozers !

Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 12:36 am
...
Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code.  I'll be back with the correct result

Yes, any tau>0.2 sec is clearly discernable.

For tau ~ 1 sec the difference is unacceptable

I'll post some pictures tomorrow after I double check everything.   I need to do some work for which I get real $$$ first  :)
Title: Re: EM Drive Developments
Post by: frobnicat on 10/28/2014 12:49 am
...
Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code.  I'll be back with the correct result

Yes, any tau>0.2 sec is clearly discernable.

For tau ~ 1 sec the difference is unacceptable

I'll post some pictures tomorrow after I double check everything.   I need to do some work for which I get real $$$ first  :)

All right. I'm a bit surprised then. Maybe not 7s but 2s seemed like possible to me (with eyeballs used to look at basic second order ringing oscillators).
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 12:59 am
...
Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code.  I'll be back with the correct result

Yes, any tau>0.2 sec is clearly discernable.

For tau ~ 1 sec the difference is unacceptable

I'll post some pictures tomorrow after I double check everything.   I need to do some work for which I get real $$$ first  :)

All right. I'm a bit surprised then. Maybe not 7s but 2s seemed like possible to me (with eyeballs used to look at basic second order ringing oscillators).

Well you were right about the way to attack this.   The actual response curves don't look to be the result of a rectangular pulse but rather a slower continuing rise. 

The dynamic magnification factor is much larger (and it matches a rectangular pulse) for the null force tests.

The experimental force measurements have much smaller dynamic magnification factor which is what gets affected with a longer tau.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/28/2014 01:05 am
John, could you please re-draw when you have a chance and the disposition 

Jose:

What with the trolls spreading their puritannical dung over your and my hysterical repartee, I have lost a great deal of interest in doing something that is no longer fun and does not pay the bills.

Still, I threw two images of the copper thing side by side and scaled them together.  Conclude what you will.

The absolute dimensions are not being revealed.  Eyeballing three point perspective lines in an attempt to scale the thing more accurately adds a lot of uncertainty to the dimensions.  Uncertainty which the experimentors could care less about removing, along with their paltry data reporting, and less than stellar protocols.

If there is something to be gained from my accurate portrayal of the proportions of the thing, then analyze frequencies and proportions.

I don't believe you're gonna find anything.

You have been a great addition to my modern lifestyle!
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/28/2014 01:25 am
I am starting to wonder if the info needed the most (predictive equations, measurements, frequencies) isn't hidden away by Non Disclosure Agreements.  Might account for the lack of later papers (after 2007) by Doctor White, and why getting other info is like pulling teeth.

There just doesn't seem to be all that much to most of these devices.  A competent machinist could probably build one in a weekend from scratch for not much more than beer money.  Oddly shaped and constructed microwave ovens basically. 
Title: Re: EM Drive Developments
Post by: zen-in on 10/28/2014 01:43 am
This device is fictional.   No one would build a dewar this way.

Couple of random links for dewars:

Buy it now at:

http://www.cryofab.com/products/cmsh_series

http://nmrwiki.org/wiki/index.php?title=Ice_in_my_dewar!_%28Liquid_helium_transport_dewar%29

http://www.kadel.com/liquid-helium-dewars/

The oracle:

http://en.wikipedia.org/wiki/Cryogenic_storage_dewar

Gravity Probe B:

http://einstein.stanford.edu/highlights/hl_100104.html

All of those references except the last one refer to cryogen storage dewars.   A liquid Helium dewar used to test something at 4.2 K is a lot more complicated.   They are almost always customized so that the dewar can be dismantled; allowing the item to be tested to be mounted on the cold foot (a high thermal resistance material that is in contact with the liquid Helium.   It would be impossible to do that with the dewar shown below.   The inner vessel labeled as the liquid Helium vessel only has a small tube for an opening.   The device to be tested is too big to fit down that tube.  So how was it assembled?   It presents an impossible "ship in a bottle" problem.
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 02:37 am
John, could you please re-draw when you have a chance and the disposition 

Jose:

What with the trolls spreading their puritannical dung over your and my hysterical repartee, I have lost a great deal of interest in doing something that is no longer fun and does not pay the bills.....
Hey John could you take a look at this drawing please:  http://web.archive.org/web/20121104025749/http://www.cannae.com/proof-of-concept/design


"Figures 1 and 2 depict two halves of the QDrive cavity. The dimensions are in cms."

Figure 2 is practically solid except for the slots, which we know from NASA to be spurious (from NASA's null test).

So what I need to know is the height of the internal cavity in Fig. 1

In Fig. 1 detail A it reads "R .1000" which to me means 0.1 cm or 1 mm.  This would say that the height is 0.1 cm = 1 mm

However, if done to scale, corresponding with the dimensions shown in Fig.2  the period may be in the wrong place and the Radius on Detail A may be 1 cm and hence the height be 1 cm.

Particularly when compared to the radius labeled R.152 that in Detail A appears much smaller than the radius labeled R.1000

What do you think ?

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC_fig_1.gif)
Title: Re: EM Drive Developments
Post by: zen-in on 10/28/2014 03:04 am
John, could you please re-draw when you have a chance and the disposition 

Jose:

What with the trolls spreading their puritannical dung over your and my hysterical repartee, I have lost a great deal of interest in doing something that is no longer fun and does not pay the bills.....
Hey John could you take a look at this drawing please:  http://web.archive.org/web/20121104025749/http://www.cannae.com/proof-of-concept/design


"Figures 1 and 2 depict two halves of the QDrive cavity. The dimensions are in cms."

Figure 2 is practically solid except for the slots, which we know from NASA to be spurious (from NASA's null test).

So what I need to know is the height of the internal cavity in Fig. 1

In Fig. 1 detail A it reads "R .1000" which to me means 0.1 cm or 1 mm.  This would say that the height is 0.1 cm = 1 mm

However, if done to scale, corresponding with the dimensions shown in Fig.2  the period may be in the wrong place and the Radius on Detail A may be 1 cm and hence the height be 1 cm.

Particularly when compared to the radius labeled R.152 that in Detail A appears much smaller than the radius labeled R.1000

What do you think ?

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC_fig_1.gif)

I am not an expert in mechanical drawing.  I think the radius marked R.1000 is meant to be a radius of 1.000 inch or whatever unit they are using.   So R.152 is a radius of .152".
Title: Re: EM Drive Developments
Post by: aero on 10/28/2014 03:07 am
Regarding the radius of curvature .1 cm or whatever. Isn't that outside the cavity? Or is the drawing printed up side down? Not likely without deliberate deceit.

As to the base drawing attached here, what is that detailed? Is it a 3 cm by 1 cm deep torus around the outer rim of the base? If the device is designed to bounce microwaves around the corner then what would the effective depth be? Before answering, please evaluate whether or not microwaves could behave in that fashion.

If so, then Cannae's idea would be for all the end reflections to occur in the same axial direction.
Title: Re: EM Drive Developments
Post by: RotoSequence on 10/28/2014 05:06 am
Regarding the radius of curvature .1 cm or whatever. Isn't that outside the cavity? Or is the drawing printed up side down? Not likely without deliberate deceit.

As to the base drawing attached here, what is that detailed? Is it a 3 cm by 1 cm deep torus around the outer rim of the base? If the device is designed to bounce microwaves around the corner then what would the effective depth be? Before answering, please evaluate whether or not microwaves could behave in that fashion.

If so, then Cannae's idea would be for all the end reflections to occur in the same axial direction.

It looks like a standard engineering drawing, so all units should be inches, with precision to thousandths of an inch.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/28/2014 08:35 am
I am starting to wonder if the info needed the most (predictive equations, measurements, frequencies) isn't hidden away by Non Disclosure Agreements.  Might account for the lack of later papers (after 2007) by Doctor White, and why getting other info is like pulling teeth.

There just doesn't seem to be all that much to most of these devices.  A competent machinist could probably build one in a weekend from scratch for not much more than beer money.  Oddly shaped and constructed microwave ovens basically.

Building a microwave copper cavity easy yes, setting up a decent measuring apparatus ecosystem for forces and electronic signals is a bit more demanding. Maybe not beyond reach of serious DIY lab though, but at significant pocket money. Household microwave oven magnetrons are unstable, wide band, not reliably "dimmable". Building that on the cheap would yield no result or inconclusive results.

I don't know if NDAs are the hurdle with poor publication. Could it be that all interested parties (theoreticians, experimenters, backers) are more interested in patents and commercialisation prospects than a Nobel ? Would they deliberately keep the things fuzzy as to keep their work under the radar of big labs, preserving the "fringe science factor" as a cover to further refine their design in secret ? Why publish anything at all then ? Just one single reproducible working device detailed design, even with lousy thrust/power ratio, would see millions if not billions $ rushing on such effect. Wonder how many labs quietly tried a shot "on the cheap" at that, saw nothing, kept silence on that null result and returned to their serious activities...

@John and those believing nothing conclusive can come out of the data because of its sketchy nature, I'm sure we all understand that it might very well be the case that indeed nothing conclusive can come at this stage with data acquired (and released) so far. But how we could know that for sure if not trying ? And even if nothing conclusive can be inferred, we can still further the subject about what is outright impossible and what is still on the table. Also surveys of many (ok, not that many in present situation) unreliable sources can turn up aspects unseen by each individual publication. This is not automatic, there is no assurance that all this time and energy won't be a waste, this is the rule of the game of being impatient (and I see lot of impatient people here) that is somehow also the rule that applies when undertaking anything at the edge and high risk/high payoff. Though in this case I wonder who would pay us... so we are only left with the high risk  :)
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 10:13 am
Regarding the radius of curvature .1 cm or whatever. Isn't that outside the cavity? Or is the drawing printed up side down? Not likely without deliberate deceit.

As to the base drawing attached here, what is that detailed? Is it a 3 cm by 1 cm deep torus around the outer rim of the base? If the device is designed to bounce microwaves around the corner then what would the effective depth be? Before answering, please evaluate whether or not microwaves could behave in that fashion.

If so, then Cannae's idea would be for all the end reflections to occur in the same axial direction.

To understand the construction, one needs to looks at the picture reproduced below (all the drawings and this picture are in http://web.archive.org/web/20121104025749/http://www.cannae.com/proof-of-concept/design   )

The top plate is indeed printed upside down with respect to the bottom plate.

The radius R.1000 is inside the resonating cavity.

Furthermore, there is another 1.000 cm of resonating cavity from the bottom cavity.

So, if the R.1000 was meant to read 1.000 cm the total resonating cavity height is:
1.000 (dimensioned on bottom plate)
+0.4 approximately (straight vertical not dimensioned on bottom plate)
+1.000 (from R.1000 incorrectly dimensioned on top plate, should be 1.000)
+0.6 approximately ((straight vertical not dimensioned on top plate)
___________
~ 3.0 cm total cavity height



Take a gander at the picture below

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC.fig3.jpg)

The dimensions are in cm.  It says so in the drawing:

Quote
Figures 1 and 2 depict two halves of the QDrive cavity. The dimensions are in cms.

The 3 cm by 1 cm deep torus around the outer rim of the base is outside, below the main cavity.

This torus is not receiving microwaves (the main cavity is the one receiving the microwaves).  Take a look at the picture: there is metal separating the resonating cavity from the torus (the torus is not seen in the picture, it is located below what's shown). 


Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 10:35 am
But how we could know that for sure if not trying ? And even if nothing conclusive can be inferred, we can still further the subject about what is outright impossible and what is still on the table. Also surveys of many (ok, not that many in present situation) unreliable sources can turn up aspects unseen by each individual publication. This is not automatic, there is no assurance that all this time and energy won't be a waste, this is the rule of the game of being impatient (and I see lot of impatient people here) that is somehow also the rule that applies when undertaking anything at the edge and high risk/high payoff. Though in this case I wonder who would pay us... so we are only left with the high risk  :)
I completely agree: I see lots of impatience as well.  I also see sermonizing about "you are going to find nothing here."

It reminds me of when I'm doing a failure analysis and impatient people want answers immediately.  Hence people quickly jump to two extremes: either that one should know the cause of failure just by looking at something (rather than analyzing the data) which is seldom the case or they are too impatient to wait the results of analysis and they jump the gun by thinking that one is never going to find the cause of failure.
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 11:50 am
Also what is being missed is that all the experimenters have huge problems conducting the experiments.  The problem is not making the cavity.  The difficulty is that the response is a resonant response over an extremely small bandwidth.  The amplitude vs. frequency response is very nonlinear.

The researchers don't quite know at what precise frequency the maximum amplitude takes place and they lack the precise equipment to keep the frequency steady at the peak amplitude.

It is no surprise that there are huge uncertainty bars because the theoretical explanations are predicated on knowing precisely the Q and the frequency of resonance which are not kept steady during the experiment.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/28/2014 11:53 am
This device is fictional.   No one would build a dewar this way.

Couple of random links for dewars. Buy it now at:

http://www.cryofab.com/products/cmsh_series


All of those references except the last one refer to cryogen storage dewars.

I'm not trying to build one. I'm doing a bit o' research to understand more of what goes into one.  Your comment was a reference to an unqualified "dewar".  Just sayin'.

Obviously, a thermos bottle is less complicated than a refrigerator, and that is the analogy.  In ten minutes of poking around on the intertubes, a "reasonably educated (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255287#msg1255287)" person can verify for himself that the illustrated dewar is a pretense.

Further analysis of the anomalous thrusts based on that picture is a waste of time.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/28/2014 12:13 pm
That's a little off.  I suggest try to read the English bits on the wiki page linked above.  The essential difference is that Woodward never even makes reference to virtual particles.  His theory does not require them at all.  In fact, in his book he explains that we don't really need them for anything.  Contrary to popular notions floating around in the advanced propulsion ZPF and QVF camps (and now this new one) virtual particles are not required to explain things like Casimir Effect.  There are perfectly reasonable explanations for CA that do not require virtual particles, but you would never get that listening to anyone who believes this wonky physics.  And I would just note to you, the percent of people who believe in treating virtual particles this way is vanishingly small.  That's why Sean Carroll at Cal Tech called this stuff "BuII$hit".

Well those high vis physicists were calling this stuff bs because they disagree with the notion of the QV acting as a plasma. The notion of virtual particles existing is generally accepted as true. Yes they are also used as an accounting mechanism in Feynman diagrams for example. A friendly reminder, the quantum world is driven by probability (things happen on a spectrum somewhere between very low and very high probabilities), and these virtual particles have a very low probability of existing at any given instant. There is no logical way to draw an arbitrary line and say something has exactly zero probability of existing.
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 12:18 pm
A common tautology found in any investigation:

"Further analysis of ...(by anybody that thinks the investigation is a waste of time) ...is a waste of time"

This tautology is very commonly found in failure analysis, for example.  The impatient ones start with the premise: you are never going to find the cause of failure.

It is also found in life: don't take chances, don't start your own business, you are going to fail, it is a waste of time...  Don't invest $$$ in the market, you are going to lose. 

Don't ask the girl to dance, she'll turn you down.  Don't ask her out, she'll turn you down  :)

I understand that people may be interested in different things, and some may not want to invest any time or take chances on something.  But why sermonize to others on what is worthwhile to spend time on or take chances on?

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/28/2014 12:32 pm
Thing is, there is many many places where people are saying "all those people working on propellantless propulsion are quacks.
That's exactly right.  When examining the issue of propellantless thrust, one is forced to look at things like personalities because people are the ones building and reporting on this stuff.  You want to measure warrant for belief in any particular scheme, and engineers want to focus on the technical aspects even when they don't understand the underlying theory, but the job is much bigger than this.  If you don't avail yourself to examining simple character quality, you're then left having to do the same analysis for Searl as you do for Eagle, and that is just a lot of wasted effort.  So even though I agree we should be focused on technical aspects in this forum, it's also true these other things are extremely important and you can't just overlook them.


You guys type too late for us East coasters to keep up.  Someone asked about how to test this stuff at ISS.  In order to do a TRL7 demonstration, you have to test in space.  In order to do this as efficiently as possible, IMHO one wants to miniaturize the power system so the whole thing will fit into a nanosat.  NASA lofts nanosats to ISS for free right now, and launches them out the little spring-loaded gizmo.  If you build a propellantless nano be it 1U, 2U or 3U, you can get the launch to space for free which recovers your miniaturization investment and removes the greatest cost barrier form such a project.  You can fly the thing around inside ISS until you want a more dramatic presentation and you can then fly it around outside as well.  Where you can go outside should be limited only by your ability to monitor the spacecraft, so if you have a few watts of transmitter, you can actually maneuver to another orbit like equatorial (something that's never been done from ISS) and who knows where you go from there?  The little GN&C's and startrackers available in modern cubesat kits may even be able to manage cislunar or interplanetary flight (and NASA has had their eye on interplanetary cubesats for quite some time now).  So the scope of any demonstration is not as easy to describe as one might guess.  One thing is certain--you want to plan a demonstration where the craft thrusts as often as possible for as long as possible so you can get duration data.  So really were one able to set up a round trip transit between say, Earth and Mars, that would be a worthy goal.  Mars Recon Orbiter has the new Elektra radio aboard and one could plan to use it periodically.

One can purchase a fully assembled nanosat built from parts previously tested in space for about $30k, so using a nano saves on the cost of the craft as well as the launch.  In most projects like this, it is the finances that stop the project, so planning to test as cheaply as possible makes good sense from a project manager's perspective and cubesats are about the cheapest space propulsion demo platform possible.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/28/2014 12:53 pm
Yes well, I understand your point but it remains that your practical application is incorrect.  It does not matter which explanation is closest to the observed value, especially when the calculations come after the data is received.  This is simple scientific method any engineer should be aware of.  How close a wrong answer is to the observed value forms no correlation whatsoever with any probability of its veracity, and asking people to think this way is inviting them to form a thinking error.  I'm perhaps overly sensitive to this error because Dr. White has on many occasions compare his model to others in this way, inviting people to form this invalid conclusion.  And it is easy to see how this happens.  Fallacies are tricky things.

Yes I agree with you. Some of the more recent mathematical predictions from http://physicsfromtheedge.blogspot.it/ and supporters are based on foundations which are teaching light new tricks ("light does have an inertial mass"), and other hasty leaps (not taking into action principles, magnitudes of competing interactions), ignoring the second law of motion.....The list is long, read for yourself. A few weeks ago, I swear I saw light suddenly go to 1.2 billion meters per second to justify a calculation. (It is in this forum I promise) The predictions may be close to being right, but are exactly wrong. A wise poster here named John should tell us about his "exactly wrong" analogy.

Oh yeah, I created a new universe inside a copper can too.  ;)

Edit:

So yeah, a lot of liberties have been taken to make the data fit the situation. I think I can safely say that no one here was born with all the answers to the problem of anomalous thrust from EMdrive, thus it is a learning experience for all those who wish to explore the problem and propose answers.

Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 12:54 pm
Table comparing Shawyer and McCulloch's predictions with measurements

c= 299705000 m/s (speed of light in air)
c= 299792458 m/s (speed of light in vacuum) (for Cannae Superconducting)

lengths in meter
rfFrequency in 1/second (microwave frequency during test)
power in watts
force in milliNewtons
force per PowerInput in milliNewtons/kW

Note: SmallDiameter for Shawyer's EM Drives obtained from his reported ShawyerDesignFactor .

predicted force (either Shawyer or McCulloch) followed (in parenthesis) by ratio of prediction divided by measurement

ShawyerForce = (2 * PowerInput * Q / c ) * ShawyerDesignFactor

McCullochForce1 = ( PowerInput * Q / rfFrequency ) * ((1/smallDiameter) - (1/bigDiameter))

McCullochForce2 = ( PowerInput * Q / c ) * ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))


ShawyerForcePerPowerInput = (2 * Q / c ) * ShawyerDesignFactor
McCullochForce1PerPowerInput = (Q / rfFrequency ) * ((1/smallDiameter) - (1/bigDiameter))
McCullochForce2PerPowerInput = (Q / c ) * ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))


Force/PowerInput of a Photon Rocket = 1 / c

Force/PowerInput ratios divided by the Force/PowerInput of a Photon Rocket, divided by Q are:

Shawyer/PhtnRckt/Q = 2 * ShawyerDesignFactor
McCulloch1/PhtnRckt/Q = (c / rfFrequency ) * ((1/smallDiameter) - (1/bigDiameter))
McCulloch2/PhtnRckt/Q = ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))





(* Cannae Superconducting *)
rfFrequency = 1.047*10^9;
cavityLength = 0.01+0.004+0.006+0.01 = 0.03;
bigDiameter =(22.86-2*(0.00430)) = 0.220;
smallDiameter = bigDiameter-2*0.01=0.200;
ShawyerDesignFactor = 0.028963

power =  10.5
Q = 1.1*(10^7)

measured force = 8 to 10
ShawyerForce = 22.32
McCullochForce1 = 50.14
McCullochForce2 = 5.254

measured ForcePerPowerInput = 761.9 to 952.4
ShawyerForcePerPowerInput = 2125.
McCullochForce1PerPowerInput = 4776.
McCullochForce2PerPowerInput = 500.3

Shawyer/PhtnRckt/Q = 0.05793
McCulloch1/PhtnRckt/Q = 0.1302
McCulloch2/PhtnRckt/Q =  0.01364



(* Shawyer Experimental *)
rfFrequency=2.45*10^9;
cavityLength=0.156;
bigDiameter=0.16;
smallDiameter=0.127546;
ShawyerDesignFactor = 0.497

power =  850   
Q = 5900

measured force = 16
ShawyerForce = 16.63
McCullochForce1 = 3.26
McCullochForce2 = 4.15

measured ForcePerPowerInput = 18.82
ShawyerForcePerPowerInput = 19.57
McCullochForce1PerPowerInput = 3.83
McCullochForce2PerPowerInput =4.88

Shawyer/PhtnRckt/Q = 0.9940
McCulloch1/PhtnRckt/Q = 0.1945
McCulloch2/PhtnRckt/Q = 0.2481



(* Shawyer Demo *)
rfFrequency=2.45*10^9;
cavityLength=0.345;
bigDiameter=0.28;
smallDiameter= 0.128853
ShawyerDesignFactor  = 0.844

power =  421 to 1200
Q = 45000

(measured force = 102.30 milliNewtons only reported for  421 watts, 243 milliNewtons/kW )

measured ForcePerPowerInput = 80 to 243
ShawyerForcePerPowerInput = 253.4
McCullochForce1PerPowerInput = 76.95
McCullochForce2PerPowerInput = 217.0

Shawyer/PhtnRckt/Q = 1.688
McCulloch1/PhtnRckt/Q = 0.5125
McCulloch2/PhtnRckt/Q = 1.445



All Brady cases have the following dimensions:

cavityLength=0.332;
bigDiameter=0.397;
smallDiameter=0.244;


(* Brady a *)
rfFrequency=1.9326*10^9;
ShawyerDesignFactor  =0.311969

power =   16.9 
Q = 7320

measured force =  0.0912
ShawyerForce = 0.2575
McCullochForce1 = 0.1011
McCullochForce2 =0.2164

measured ForcePerPowerInput = 5.396
ShawyerForcePerPowerInput = 15.24
McCullochForce1PerPowerInput = 5.982
McCullochForce2PerPowerInput =12.81

Shawyer/PhtnRckt/Q = 0.6239
McCulloch1/PhtnRckt/Q = 0.2449
McCulloch2/PhtnRckt/Q = 0.524384

(* Brady b *)   STATISTICAL OUTLIER
rfFrequency=1.9367*10^9;
ShawyerDesignFactor  = 0.310959

power = 16.7
Q =  18100

measured force = 0.0501
ShawyerForce = 0.6272
McCullochForce1 = 0.2465
McCullochForce2 =0.5289

measured ForcePerPowerInput = 3.000
ShawyerForcePerPowerInput = 37.56
McCullochForce1PerPowerInput = 14.76
McCullochForce2PerPowerInput =31.67

Shawyer/PhtnRckt/Q = 0.6219
McCulloch1/PhtnRckt/Q = 0.2444
McCulloch2/PhtnRckt/Q = 0.5244


  (* Brady c *)
rfFrequency = 1.8804*10^9;
ShawyerDesignFactor  = 0.325498

power = 2.6
Q = 22000

measured force = 0.05541
ShawyerForce = 0.1242
McCullochForce1 = 0.04805
McCullochForce2 = 0.1001

measured ForcePerPowerInput = 21.31
ShawyerForcePerPowerInput = 47.79
McCullochForce1PerPowerInput = 18.48
McCullochForce2PerPowerInput = 38.49

Shawyer/PhtnRckt/Q = 0.6510
McCulloch1/PhtnRckt/Q = 0.2517
McCulloch2/PhtnRckt/Q = 0.5244
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 12:57 pm
The above table for Cannae superconducting is based on the dimensions as noted, which at present are the best estimates (the drawing specifies that its dimensions are given in cm, one should take the inner cavity dimensions for the calculations).

See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1277772#msg1277772

If anybody can contribute further, by correcting the 3 cm cavity height, such criticism is always strongly welcomed.  As usual I will correct accordingly and I will acknowledge and thank the person doing the correcting.
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 01:02 pm
Taking into account that the amplitude vs. frequency response is very nonlinear, and that the researchers don't quite know at what precise frequency the maximum amplitude takes place and they lack the precise equipment to keep the frequency steady at the peak amplitude, the prediction formulas do a pretty good job.

The Q ranges from ~5,900 to 1,100,000.  The power ranges from 2.6 watts to 1200 watts.
The cavity axial lengths range from 0.03 m to 0.345 m.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/28/2014 01:05 pm
Further analysis of the anomalous thrusts based on that picture is a waste of time.

A common tautology found in any investigation:

"Further analysis of ...(by anybody that thinks the investigation is a waste of time) ...is a waste of time"

Based only on the picture of the fictional dewar.  Not all investigations.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/28/2014 01:07 pm
Hey John could you take a look at this drawing please:

I did, and wrote a screed fifteen minutes ago, and fumble fingered the post, losing it in the well, aether.  'Tis only my time.

Short answer.  The drawing is poorly dimensioned, but graphically, the depth of that cavity is 1 cm.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/28/2014 01:11 pm
Oh yeah, I created a new universe inside a copper can too.

Now here's a copper can within which, I assure you, you will find a new universe...

https://www.youtube.com/watch?v=JCBfzAA8Fpw
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 01:11 pm
Hey John could you take a look at this drawing please:

I did, and wrote a screed fifteen minutes ago, and fumble fingered the post, losing it in the well, aether.  'Tis only my time.

Short answer.  The drawing is poorly dimensioned, but graphically, the depth of that cavity is 1 cm.

OK, great we have settled that.

Now please take a look at this picture.

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC.fig3.jpg)

The total cavity is formed by both cavities. So it is at least 1cm+1cm =2cm

But there are also the contributions of the straight vertical edges. Which are about 0.4cm+0.6cm=1cm Agree?

So the total cavity is 1cm+0.4cm+0.6cm+1cm = 3 cm
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/28/2014 01:22 pm
@John and those believing nothing conclusive can come out of the data because of its sketchy nature, I'm sure we all understand that it might very well be the case that indeed nothing conclusive can come at this stage with data acquired (and released) so far.

Sorry.  I'm just another frustrated white american male.  I do appreciate your all's work.  Let's give the experimentors a big hand, ok?

https://www.youtube.com/watch?v=TAryFIuRxmQ
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/28/2014 01:28 pm
So the total cavity is 1cm+0.4cm+0.6cm+1cm = 3 cm

Thinking the two halves woudl be the same, I'd guess 0.5 + 0.5 = 1 cm, but hey.

I suppose there's a band, not illustrated, which would "seal" the joint between the two fitments.
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 01:36 pm
So the total cavity is 1cm+0.4cm+0.6cm+1cm = 3 cm

Thinking the two halves woudl be the same, I'd guess 0.5 + 0.5 = 1 cm, but hey.

I suppose there's a band, not illustrated, which would "seal" the joint between the two fitments.

I don't quite see why would 1 cm would become 0.5 cm, unless they are mating.

It looks that you are assuming that one half is a male and the other half is a female and they mate with each other, but the picture does not show any mating.

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC.fig3.jpg)

Also you are not including the  vertical edges (unless you assumed that the straigth edges dissapear upon mating both halves): the picture shows no penetration of the vertical straight edge into the other half.

The picture shows no explicit mating.  The picture does not show any explicit penetration of one half into the other half.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/28/2014 02:25 pm
I am starting to wonder if the info needed the most (predictive equations, measurements, frequencies) isn't hidden away by Non Disclosure Agreements.  Might account for the lack of later papers (after 2007) by Doctor White, and why getting other info is like pulling teeth.

There just doesn't seem to be all that much to most of these devices.  A competent machinist could probably build one in a weekend from scratch for not much more than beer money.  Oddly shaped and constructed microwave ovens basically.

Sonny told Pop Sci when they came for a visit that he was restrained by NDA, but there are long odds on that.  Who would have asked him to sign it?  (Apart from the outside work they did for Boeing, wich makes perfect sense.)  Rather he has likely asked others to so sign.  The real issue here is that Sonny can't patent anything since he didn't invent the stuff.  Best he can do is operate under trade secret status so you should not expect ever to get much detail about his setup.

BTW as we mentioned before, this cannot be done with a microwave oven magnetron.  It needs a continuous wave magnetron.  They're much more expensive, most often water cooled and not the kind of thing you can pick up on EBay for $25.  They draw several kW of power and if you mess up with one, they're fry the inside of your eyeballs in 3 seconds.  So this is  not as simple as it seems.
Title: Re: EM Drive Developments
Post by: aero on 10/28/2014 02:47 pm
So the total cavity is 1cm+0.4cm+0.6cm+1cm = 3 cm

Thinking the two halves woudl be the same, I'd guess 0.5 + 0.5 = 1 cm, but hey.

I suppose there's a band, not illustrated, which would "seal" the joint between the two fitments.

I don't quite see why would 1 cm would become 0.5 cm, unless they are mating.

It looks that you are assuming that one half is a male and the other half is a female and they mate with each other, but the picture does not show any mating.

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC.fig3.jpg)

Also you are not including the  vertical edges (unless you assumed that the straigth edges dissapear upon mating both halves): the picture shows no penetration of the vertical straight edge into the other half.

The picture shows no mating.  The picture does not show any penetration of one half into the other half.

I'm assuming this was tested with internal vacuum. Or was it just frozen air that was vaporized by RF energy?
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 02:50 pm
...
I'm assuming this was tested with internal vacuum. Or was it just frozen air that was vaporized by RF energy?

Quote
the POC cavity and attached vacuum tubing are only supported by the central vacuum pipe depicted in Figure 4. The central vacuum pipe is attached to a support arm depicted in Figure 4. During experimental runs, the cavity and attached vacuum tubes are supported by two Cooper Instruments LFS 210 load cells.
....
the helium dewar depicted in Figure 4 is vacuum sealed.  Pressure over the liquid helium is reduced to 50 Torre reducing its temperature to 2.3 K. Prior to experimental runs, the vacuum seal on the helium vessel is broken, bringing pressure above the liquid helium to atmospheric pressure. Tests on the cavity were then run while the liquid helium bath was below its atmospheric boiling temperature. The helium pump-down procedure eliminated boiling helium buoyancy beneath the cavity as a potential cause of false-positive experimental results.

Frobnicat: your comments would be appreciated whether the heated air artifact would be nullified by this test

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=617589;image)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/28/2014 02:51 pm
I am starting to wonder if the info needed the most (predictive equations, measurements, frequencies) isn't hidden away by Non Disclosure Agreements.  Might account for the lack of later papers (after 2007) by Doctor White, and why getting other info is like pulling teeth.

There just doesn't seem to be all that much to most of these devices.  A competent machinist could probably build one in a weekend from scratch for not much more than beer money.  Oddly shaped and constructed microwave ovens basically.

Sonny told Pop Sci when they came for a visit that he was restrained by NDA, but there are long odds on that.  Who would have asked him to sign it?  (Apart from the outside work they did for Boeing, wich makes perfect sense.)  Rather he has likely asked others to so sign.  The real issue here is that Sonny can't patent anything since he didn't invent the stuff.  Best he can do is operate under trade secret status so you should not expect ever to get much detail about his setup.

BTW as we mentioned before, this cannot be done with a microwave oven magnetron.  It needs a continuous wave magnetron.  They're much more expensive, most often water cooled and not the kind of thing you can pick up on EBay for $25.  They draw several kW of power and if you mess up with one, they're fry the inside of your eyeballs in 3 seconds.  So this is  not as simple as it seems.

Nope, POPSCI got it wrong:

"Did Harold White sign NDAs as an individual or as a NASA civil servant? Who did he sign these NDAs with?

White has not signed any NDAs. The article has it backwards. In order for the Popular Science author to get briefed on the referenced technology, he would need to sign an NDA with the government as the noted technology has an invention disclosure. An NDA is the mechanism to protect the IP content, but still allow access to interested parties for consideration."

http://spaceref.com/nasa-hack-space/propulsion/clarifying-nasas-warp-drive-program.html

Title: Re: EM Drive Developments
Post by: Mulletron on 10/28/2014 02:57 pm
@Rodal
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1277372#msg1277372
Is what you're looking for from Dr. White on page 5?

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdf

Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 03:03 pm
@Rodal

Is what you're looking for from Dr. White on page 5?

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdf

Thanks for taking the time to look for this, but no, this report by Dr. White does not contain any explicit equation with which one can calculate a thrust force.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/28/2014 03:24 pm
http://www.nasa.gov/pdf/501329main_TA02-InSpaceProp-DRAFT-Nov2010-A.pdf

Here's some feel goods, for the dreamers out there.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/28/2014 03:33 pm
@Rodal

Is what you're looking for from Dr. White on page 5?

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdf

Thanks for taking the time to look for this, but no, this report by Dr. White does not contain any explicit equation with which one can calculate a thrust force.

That's the most math I've seen come out of Dr. White's public releases on his QVT. That lack of usable material and transparancy is what drove me looking for the kind of answers linked to below.

I always suspected that White was just taking what he was researching about dielectric thrust and applying that to already known methodology used in ion thrusters or MHD drives, and getting his thrust calcs that way. I wasn't satisfied with that so I went looking for more.

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269074#msg1269074

Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 04:01 pm
The amplitude vs. frequency response is very nonlinear, and  the researchers don't quite know at what precise frequency the maximum amplitude takes place and they lack the precise equipment to keep the frequency steady at the peak amplitude.

Question: what's the speed of light

Wrong answer: an unqualified 299 792 458 meters/second

Correct answer: it depends on the medium


Add up to the fact that the experimenters don't precisely know the frequencies at which peak amplitude (and thus peak Q) resonance occurs, and they cannot keep the frequency within the very narrow bandwidth for high Q the fact that the speed of light depends on the medium, and the nonlinearities associated with dielectrics and what one has is a lot of confusion talk and confusion writing from the experimenters when dealing with dielectrics.  When dealing with dielectrics to me they are more like people feeling their way around a dark room, very empirically.  I write that, because none of the labs to my knowledge, including Eagleworks, has dielectrometry, DSC, TGA, TMA, DTMA, FTIR, MTS, and other means to properly assess the material properties of the polymer dielectric materials involved.

They put a dielectric in, the amplitude vs. frequency response changes, they feel their way around, sometimes they may end up with a higher amplitude.  It depends on their frequency sweep precision, tuning, staying within bandwith, etc.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/28/2014 04:15 pm
It looks that you are assuming that one half is a male and the other half is a female and they mate with each other...

Nahh...   You really think I'm gonna fall for that one?

Not sure how they made the thing, but I was figuring the 1cm depth, plus a 0.5cm "lip", visible in the section and the detail.  You make two of the round things things, and join 'em lip to lip.  (don't start with a mating call, pardner)  Either you weld them together, or you mechanically fasten them with a 1cm (-) band.

Perhaps thru a lost wax process, you could make the hollow round thing, but I'm guessing not.  Note that their cut-away view kinda sorta implies that the fictional dewar was monolithically cast.

Count with me to six, now, willya?

Seriously, you say, "...to me they are more like blind people feeling their way around very empirically."  What is driving you to such exhaustive consideration of these various reports?
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 04:20 pm
There is no explicit mating shown in the referenced picture (reproduced below), and again you are considering the lip from only  one side.  There is also a contacting lip on the other side that I took into account as well as the curved recess from the other side.  There is no penetration shown in this picture so you have 1 cm + 0.4 cm lip + 0.6 lip + 1cm = 3 cm depth of cavity (measured in vertical direction)

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC.fig3.jpg)
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 06:02 pm
...
Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code.  I'll be back with the correct result

Yes, any tau>0.2 sec is clearly discernable.

For tau ~ 1 sec the difference is unacceptable

I'll post some pictures tomorrow after I double check everything.   I need to do some work for which I get real $$$ first  :)

All right. I'm a bit surprised then. Maybe not 7s but 2s seemed like possible to me (with eyeballs used to look at basic second order ringing oscillators).

Eagleworks inverted torsional pendulum response to exponentially decaying forcing functions (force in Newtons)

 © Rodal 2014  :)


Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{0,t>= 30}}],tau=0,0.5,1,2,3

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=0,0.5,1,2,3

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=2
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 06:33 pm
I want to thank and recognize in public, aero, who sent me the following message noticing that there is yet another formula to calculate the thrust:



Dr. Rodal,

The Chinese paper gives this formula for thrust. ..Fe and Fm are the electrical and magnetic field forces and the subscripts are 1-big, 2-small, 3-sidewall.

Fa=Q[∫A1 (Fe1+Fm1)dA-∫A2 (fe2+fm2)dA -∫A3 (Fe3+Fm3)cosθdA)] (13)

(Equation 13 is on page 6 of the translated 2010 paper. http://www.emdrive.com/NWPU2010translation.pdf
Journal of Northwestern Polytechnical University Vol 28 No 6 Dec 2010, Applying Method of Reference 2 to Effectively Calculating Performance of Microwave Radiation Thruster, Yang Juan,Yang Le,Zhu Yu,Ma Nan
(College of Astronautics,Northwestern Polytechnical University,Xi′an 710072,China) )

where Fe and Fm are normal to the cavity surface, pointing inward,
and
The amount of force is |Fe|=1/2eoE^2
The amount of force is |Fm|=1/2uoH^2

Note that Q does already appear in the force equation (13) above.

aero
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 08:30 pm
...
Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code.  I'll be back with the correct result

Yes, any tau>0.2 sec is clearly discernable.

For tau ~ 1 sec the difference is unacceptable

I'll post some pictures tomorrow after I double check everything.   I need to do some work for which I get real $$$ first  :)

All right. I'm a bit surprised then. Maybe not 7s but 2s seemed like possible to me (with eyeballs used to look at basic second order ringing oscillators).

Eagleworks inverted torsional pendulum response to exponentially decaying forcing functions (force in Newtons)

 © Rodal 2014  :)

The previous plots showed the torsional angular motion due those purely torsional forcing functions .

It is interesting to look at the chaotic motion of the swinging angular motion of the pendulum for the lower moment of inertia motion, due to coupled nonlinearity for the following case:

Forcing function for torsional force:
Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{0,t>= 30}}],tau=0.000001

Forcing function for swinging force excitation (lower moment of inertia angular direction)
Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=0.000001

NOTE: the amplitude is about 1% of the previous motion, so the chaotic motion is not noticeable for this forcing function during this time period.  Notice that the chaotic motion persists long after the forcing excitation has died out: a chaotic artifact due to the nonlinear equations of motion  , nothing to do with the excitation. 

That's the problem with inverted pendulum, and that's why I have criticized the use of inverted pendulums instead of a classical Cavendish set-up as used to measure the inverse square law of gravitation and as used by Brito et.al  But again, for this forcing function: so far not noticeable.

Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/28/2014 08:43 pm
I'm not following what you're calling "chaotic".  What's the period period of this beam?
Title: Re: EM Drive Developments
Post by: aero on 10/28/2014 08:49 pm
@ Dr. Rodel - You're Welcome.

With the right choice of resonant mode frequency the standing wave within the cavity results in unbalanced axial pressure giving thrust to the cavity, via the equation from the Chinese paper. The question still arises,

"Where does the momentum balance?"

Conservation is still very much of interest after all.

We are kind of at the point in sailing ship days where some crewman tied his sleeping roll to his oar, held it up and told his buddies, "Look, if I hold the corners with my feet I don't have to paddle!!"

That was long before tall ships with area ruled hulls and Bermuda rigged masts.
Title: Re: EM Drive Developments
Post by: Rodal on 10/28/2014 09:10 pm
@ Dr. Rodel - You're Welcome.

With the right choice of resonant mode frequency the standing wave within the cavity results in unbalanced axial pressure giving thrust to the cavity, via the equation from the Chinese paper. The question still arises,

"Where does the momentum balance?"

Conservation is still very much of interest after all.

We are kind of at the point in sailing ship days where some crewman tied his sleeping roll to his oar, held it up and told his buddies, "Look, if I hold the corners with my feet I don't have to paddle!!"

That was long before tall ships with area ruled hulls and sloop rigged masts.


1) None, absolutely none of the researchers have actually measured linear acceleration of the center of mass of the system under measurement.  No discussion of conservation of momentum is really an issue until somebody does.  The ideal test would be for a free-free body, as done by the Wright brothers, Goddard, even the Gossamer Albatros, and the recent demonstration of the man-powered helicopter (which was considered impossible until recently).

2) NASA Eagleworks, the Chinese, Cannae, and Shawyer (except his demo) have made measurements on constrained systems.  None of the researchers have analyzed their measurement systems to analyze whether indeed conservation of momentum is being violated.  The closest experiment to a violation of conservation of momentum is Shawyer's demo experiment, but again, the EM Drive demo is restrained and the whole setup is rotating instead of linearly accelerating.  No linear acceleration of the center of mass was measured and the measurement system was not analyzed.

If an astronaut inside a spacecraft puts a sensor on a wall of a spacecraft and then takes a big hammer and hits the wall of the spacecraft, he will measure dynamic motion of the wall of the spacecraft.  That doesn't mean that conservation of momentum was violated.  In that experiment the center of mass of the whole system (astronaut, hammer and walls) did not experience any acceleration due to the astronauts hammering the wall.  However, the wall did move and it had a noticeable dynamic response.

Discussions of violation of conservation of momentum are premature until an experimenter shows that the center of mass of the whole system experienced an acceleration response either by flying the object unrestrained (free-free) or they properly analyze the measurement system - which nobody has done.
Title: Re: EM Drive Developments
Post by: aero on 10/28/2014 09:46 pm
@ Dr. Rodel - You're Welcome.

With the right choice of resonant mode frequency the standing wave within the cavity results in unbalanced axial pressure giving thrust to the cavity, via the equation from the Chinese paper. The question still arises,

"Where does the momentum balance?"

Conservation is still very much of interest after all.

We are kind of at the point in sailing ship days where some crewman tied his sleeping roll to his oar, held it up and told his buddies, "Look, if I hold the corners with my feet I don't have to paddle!!"

That was long before tall ships with area ruled hulls and sloop rigged masts.


1) None, absolutely none of the researchers have actually measured linear acceleration of the center of mass of the system under measurement.  No discussion of conservation of momentum is really an issue until somebody does.  The ideal test would be for a free-free body, as done by the Wright brothers, Goddard, even the Gossamer Albatros, and the recent demonstration of the man-powered helicopter (which was considered impossible until recently).

2) NASA Eagleworks, the Chinese, Cannae, and Shawyer (except his demo) have made measurements on constrained systems.  None of the researchers have analyzed their measurement systems to analyze whether indeed conservation of momentum is being violated.  The closest experiment to a violation of conservation of momentum is Shawyer's demo experiment, but again, the EM Drive demo is restrained and the whole setup is rotating instead of linearly accelerating.  No linear acceleration of the center of mass was measured and the measurement system was not analyzed.

If an astronaut inside a spacecraft puts a sensor on a wall of a spacecraft and then takes a big hammer and hits the wall of the spacecraft, he will measure dynamic motion of the wall of the spacecraft.  That doesn't mean that conservation of momentum was violated.  In that experiment the center of mass of the whole system (astronaut, hammer and walls) did not experience any acceleration due to the astronauts hammering the wall.  However, the wall did move and it had a noticeable dynamic response.

Discussions of violation of conservation of momentum are premature until an experimenter shows that the center of mass of the whole system experienced an acceleration response either by flying the object unrestrained (free-free) or they properly analyze the measurement system - which nobody has done.

Gtocha - Though Shawyer's Demonstrator test on the turntable looks suspiciously like motion ... That is a data sample of one and we have enough trouble with a data sample of seven.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/28/2014 10:13 pm
Shawyer made an explanation years ago about how the thruster would develop less and less thrust the faster it was going, but the mechanism made no sense, and it still proposed to violate conservation, and the whole notion of velocity changing thrust is again, a violation of relativity.  Velocity relative to what exactly?  Made no sense and that was just before they cut his funding in Great Britain, IIRC. 
Title: Re: EM Drive Developments
Post by: aero on 10/28/2014 10:36 pm
Shawyer made an explanation years ago about how the thruster would develop less and less thrust the faster it was going, but the mechanism made no sense, and it still proposed to violate conservation, and the whole notion of velocity changing thrust is again, a violation of relativity.  Velocity relative to what exactly? ...snip...

I agree with that. His explanation seemed to me to require the thruster to remember the reference frame at the time of "Power on" and limit itself to accelerations that conserved everything. Maybe he was saying something else but if so, it was very obscure to me.

I don't know about his funding.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/29/2014 12:08 am
There is no explicit mating shown in the referenced picture (reproduced below), and again you are considering the lip from only  one side.

Not quite sure I unnerstand ya, doc.  Here's my guess as to what the section thru the completely fabricated round thing is.
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 12:18 am
There is no explicit mating shown in the referenced picture (reproduced below), and again you are considering the lip from only  one side.

Not quite sure I unnerstand ya, doc.  Here's my guess as to what the section thru the completely fabricated round thing is.

So I reckon that  you came up with the same cavity height: 3 cm (three centimeters), partner

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/29/2014 12:25 am
There is no explicit mating shown in the referenced picture (reproduced below), and again you are considering the lip from only  one side.

Not quite sure I unnerstand ya, doc.  Here's my guess as to what the section thru the completely fabricated round thing is.

So I reckon that  you came up with the same cavity height: 3 cm (three centimeters), partner

Thanks

Yahbut, as you see, I said, 0.5 + 0.5 for those fractional dimensions.  Never could figger out how you got 0.4 + 0.6, but never mind.  Notice how many of the dimensions are estimates.
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 12:36 am
Yahbut, as you see, I said, 0.5 + 0.5 for those fractional dimensions.  Never could figger out how you got 0.4 + 0.6, but never mind.  Notice how many of the dimensions are estimates.

Walkin' in Tall Cotton - Doin' Aw'right
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/29/2014 12:52 am
Walkin' in Tall Cotton - Doin' Aw'right

Watch out my man, the trolls'll gitcha.

Ise walkin' on gilded splinters (https://www.youtube.com/watch?v=GzHUP3fVN0Y).

Dr. John signin' out.
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 02:11 am
All right. I'm a bit surprised then. Maybe not 7s but 2s seemed like possible to me (with eyeballs used to look at basic second order ringing oscillators).

Eagleworks inverted torsional pendulum response to exponentially decaying forcing functions (force in Newtons)

 © Rodal 2014  :)

The previous plots showed the torsional angular motion due those purely torsional forcing functions .

It is interesting to look at the chaotic motion of the swinging angular motion of the pendulum for the lower moment of inertia motion, due to coupled nonlinearity for the following case:

Forcing function for torsional force:
Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{0,t>= 30}}],tau=0.000001

Forcing function for swinging force excitation (lower moment of inertia angular direction)
Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=0.000001

NOTE: the amplitude is about 1% of the previous motion, so the chaotic motion is not noticeable for this forcing function during this time period.  Notice that the chaotic motion persists long after the forcing excitation has died out: a chaotic artifact due to the nonlinear equations of motion ..
...

It is fascinating that the (for the above forcing functions and time period very small amplitude ) nonlinear chaotic vibration due to nonlinear coupling of swinging with torsional modes of the Eagleworks inverted torsional pendulum (see above description and plot attached again below) resembles the chaotic calls of the the 7 years old female dog "Schaka" in this study (but with different frequencies):  http://edoc.hu-berlin.de/dissertationen/riede-tobias-2000-06-26/HTML/riede-ch3.html

"Nonlinear systems display a number of typical phenomena which are briefly described here. Aperiodic (or chaotic) oscillations are characterized by irregularity, and in extreme cases there are no repeating periods at all. Period doubling (subharmonic regime) is another characteristic of nonlinear dynamical systems. It is characterized by a sudden change in the frequency of the oscillations, such that the spacing between spectral components is halved."

Eagleworks inverted pendulum time series displays similar high amplitude during the chaotic and biphonic episode of the dog:

(http://edoc.hu-berlin.de/dissertationen/riede-tobias-2000-06-26/HTML/objct8.png)

It is interesting that Brito, Marini and Galian, in (default) Argentina, with much less money than NASA in the USA to perform their tests understood these issues (using instead an oil-damped Cavendish pendulum) when they nullified the Mach Lorentz effec Thruster.  Well, hopefully Johns Hopkins will test these EM Drives with their Cavendish balance.
Title: Re: EM Drive Developments
Post by: zen-in on 10/29/2014 04:30 am
There is no explicit mating shown in the referenced picture (reproduced below), and again you are considering the lip from only  one side.  There is also a contacting lip on the other side that I took into account as well as the curved recess from the other side.  There is no penetration shown in this picture so you have 1 cm + 0.4 cm lip + 0.6 lip + 1cm = 3 cm depth of cavity (measured in vertical direction)

(http://web.archive.org/web/20121104025749im_/http://www.cannae.com/images/POC.fig3.jpg)

The two halves would each need an O-ring channel and some means of fastening them together if they ever hoped to pump it down to just 50 Torr, as claimed.   So maybe they have two sets of drawings:  One set that were used to fabricate the device and this set that appears to be fictional.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/29/2014 05:03 am
Zen-in:

Step by step photo's with explanations as to how this device was fabricated:

http://web.archive.org/web/20121005004712/http://www.cannae.com/proof-of-concept/experimental-results/2-uncategorised/30-appendix-d

And:

Quote
The QDrive POC cavity demonstrated an unbalanced force that was approximately 2-3% of numerical method predictions for peak-force generation of the design. The POC cavity did not develop full thrust due to power limitations into the cavity. The low field energy in the cavity is related to low cavity Q and power losses in the cavity that are not related to Niobium BCS losses. The likely cause for this power loss in the cavity is related to signal-port design and port placement on the cavity.

If that helps anybody.

Does this make sense?
http://web.archive.org/web/20121102083203/http://www.cannae.com/theory-of-operation/principles-of-operation

Quote
This section will show that a radially-asymmetric, equatorially-asymmetric resonating cavity can generate a time-averaged MFF that is not counterbalanced by an equal and opposite time-averaged EFF. This imbalance in the combined MFF and EFF yields a time-averaged net imbalance in the total Lorentz force exerted on the cavity. An unbalanced force is generated.

The resonating cavity depicted in Figure 1 below is a QDrive resonating cavity capable of generating a time-averaged linear imbalance in the net Lorentz forces exerted on the cavity by operation of a TM010 EM wave within the cavity. The linear unbalanced-force vector on the cavity of Figure 1 is coincident with the z-axis of the cavity.

There are 60 identical slots located on the bottom plate of the cavity of Figure 1. The slots are located in areas of the resonating cavity that experience strong magnetic fields and weak electric fields.

figure 1

Figure 1

On the top plate of the cavity, above the slots of the bottom plate, Lorentz forces generated on the cavity walls by the magnetic field of the EM wave point in the positive z-direction. On the bottom plate, on areas of the cavity wall located between the slots (called bridges), Lorentz forces generated by the magnetic field of the EM wave point in the negative z-direction.

When operated with a TM010 EM wave, the cavity generates a time-averaged net imbalance in Lorentz forces on the cavity. The imbalance in Lorentz forces occurs because the magnetic-field, Lorentz-force pressure in the positive z-direction on the top plate is greater than the negative z-directed, magnetic-field, Lorentz-force pressure on the bottom plate.

The EFF generated by the TM010 wave operating in the cavity does not counterbalance the positive z-directed MFF. In the areas of the cavity where strong electric fields occur, the cavity is symmetrical with respect to z-directed, electric-field Lorentz forces. The cavity asymmetries occur in areas of weak electric field and strong magnetic field, meaning that the imbalance in EFF generated by these asymmetries (the slots located on the bottom plate) is negligible compared with the MFF imbalance generated by these asymmetries.

In the cavity of Figure 1, the differential in magnetic-field Lorentz forces is not counterbalanced by the differential in electric-field Lorentz forces.  A time-averaged, net-unbalanced Lorentz force is generated on the cavity by operation of a TM010 EM wave within the cavity.

This one gave me a headache:

http://web.archive.org/web/20121107172136/http://www.cannae.com/theory-of-operation/conservation-laws

Part lecture in basic physics, part equations I can't grasp.

I'll finish with this:

http://web.archive.org/web/20121107172131/http://www.cannae.com/theory-of-operation/appendices
Title: Re: EM Drive Developments
Post by: frobnicat on 10/29/2014 09:58 am
...
I'm assuming this was tested with internal vacuum. Or was it just frozen air that was vaporized by RF energy?

Quote
the POC cavity and attached vacuum tubing are only supported by the central vacuum pipe depicted in Figure 4. The central vacuum pipe is attached to a support arm depicted in Figure 4. During experimental runs, the cavity and attached vacuum tubes are supported by two Cooper Instruments LFS 210 load cells.
....
the helium dewar depicted in Figure 4 is vacuum sealed.  Pressure over the liquid helium is reduced to 50 Torre reducing its temperature to 2.3 K. Prior to experimental runs, the vacuum seal on the helium vessel is broken, bringing pressure above the liquid helium to atmospheric pressure. Tests on the cavity were then run while the liquid helium bath was below its atmospheric boiling temperature. The helium pump-down procedure eliminated boiling helium buoyancy beneath the cavity as a potential cause of false-positive experimental results.

Frobnicat: your comments would be appreciated whether the heated air artifact would be nullified by this test


I agree with Aero that it is reasonable to think the resonant cavity is evacuated, that is sealed, obviously there can't be "warm jet leaks" in such a configuration. If it wasn't sealed relative to atmosphere (eg through the innermost tubing (that also serves as the microwave power wire ?) , then the outside air would rush to condensate and fill the cavity (and give quite a lot of heat to the helium bath...)

Overall, playing with low temperatures, any dynamics in "differential temperature that creates differentials on pressures and movements of fluids, jets or otherwise" would give stronger spurious signals. A 1K temp differential would give on the order of 100 more thrust or momentum working at 3K than at 300K.

So my humble opinion : yes it would nullify a "heated air artifact" hypothesis, but at the condition it was conducted in a sensible way. And I see a lot more way to introduce hard to find artifacts by conducting those experiments tinkering with cryogenic fluids rather than in lab ambient conditions. A much much simpler way to get rid of the "warm jet hypothesis" is to make the cavity sealed (and able to withstand the few hundreds of Pascals differential the heated gas will put). I already said that (at the beginning of this thread) : as simple as possible  clean setup, even with lousy thrust/power ratio (but still better than 1/c) is just the experiment all "classically educated" scientists are waiting for to give any credibility to those results. This is supposed to work at room temperature, so let's prove it does really work at room temperatures. Adding more bells and whistles to improve the thrust/power is just adding more ways to fool ourselves (well, experimenters in this case).

I won't comment anymore on this superconducting device before I see where the warm jet hypothesis is leading with Brady's report. I'm on heat propagation transients, rewriting my equations with Hagen-Poiseuille flow (leaks probably longer than wider, so orifice in thin plate is not good), trying to elucidate the microwave/water vapor coupling, and scraping the thrust vs time graphs to do some further dynamics studies (and share with anybody).

In vacations with limited connectivity, all this will take a few days.

Questions about brady's devices (anomalous...)  : what was the best guests as to the thickness of copper for the walls ? what was the best guess for the thickness of copper and epoxy(?) for the PCBs closing the ends ? is it specified anywhere in those reports if the cavity is hermetically sealed or not (by hermetic I mean : should you put some soda in it, close, shake, wait an hour, open, you should hear a pshhit) ? in a cavity excited at resonance, would some parts of the walls see more power dissipated by area than others or would the power distribute evenly on all inner surfaces ?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/29/2014 10:44 am
Shawyer made an explanation years ago about how the thruster would develop less and less thrust the faster it was going, but the mechanism made no sense, and it still proposed to violate conservation, and the whole notion of velocity changing thrust is again, a violation of relativity.  Velocity relative to what exactly?  Made no sense and that was just before they cut his funding in Great Britain, IIRC.

Yes I saw that too on one of his papers, and then again on the latest presentation there is mention to "energy conservation" but his "efficiency decay" with speed has
1/ indeed a problem of definition (as you and aero notice : speed relative to what ?)
2/ indeed a violation of Lorentz invariance (very accurately checked so far, in lab or with astronomical sources)
3/ seemingly not much impact on his mission profiles that still give more kinetic energy at the end than was put into, by a wide margin

Handwaving "energy conservation" away that way is less than satisfying. I won't comment anymore on Shawyer's theories or mission profiles.
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 10:54 am
....
This one gave me a headache:

http://web.archive.org/web/20121107172136/http://www.cannae.com/theory-of-operation/conservation-laws

Part lecture in basic physics, part equations I can't grasp.

I'll finish with this:

http://web.archive.org/web/20121107172131/http://www.cannae.com/theory-of-operation/appendices

This stuff from Cannae and from the Chinese, that one can derive from Maxwell's equations a Lorentz force imbalance is erroneous.  What it shows is a lack of understanding of the stress tensor.

The paper by Egan correctly solves the problem of force balance not just for a truncated cone, but for any cavity shape (at the end of Egan's paper):

http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html

Title: Re: EM Drive Developments
Post by: FITZY on 10/29/2014 10:58 am
Re: Frobnicat and his comments on Shawyer's mission profiles.   Shawyer's "Energy conservation" attempts will be disproven, with the first free run experiments.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/29/2014 11:43 am
Not sure how they made the thing, but I was figuring the 1cm depth, plus a 0.5cm "lip", visible in the section and the detail.  You make two of the round things, and join 'em lip to lip.  (don't start with a mating call, pardner)  Either you weld them together, or you mechanically fasten them with a 1cm (-) band.

Zen-in:

Step by step photo's with explanations as to how this device was fabricated:

http://web.archive.org/web/20121005004712/http://www.cannae.com/proof-of-concept/experimental-results/2-uncategorised/30-appendix-d

Damn, I'm good.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/29/2014 11:51 am
...as simple as possible  clean setup, even with lousy thrust/power ratio (but still better than 1/c) is just the experiment all "classically educated" scientists are waiting for to give any credibility to those results.

Choose one:

1) Well duh.

2) Not gonna happen.

3) Pending weather change in Hades.

Quote from: Frob
In vacations with limited connectivity, all this will take a few days.

You do this stuff on vacation?  Sheesh.

Quote from: Frob
what was the best guess as to the thickness of copper for the walls?

Well I guessed 1/8".

Quote from: Frob
you should hear a pshhit.

Try to express yourself without using profanity.

Quote from: Frob
would the power distribute evenly on all inner surfaces?

I don't see how, what with the completely assymetrical location of the M/W feed horn.

Oh.  And, nice short post there Fitzy.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/29/2014 11:55 am
"super insulation" is added by SuperGenious:

Me not get it, Kemosabe. 

Plus, what is that piece of scientific equipment in the lower right?   The black, roughly rectangular object with the light colored cylindrical object.  Not sure I recognize it.

Technical note:  Reduce the dimensional size of the image.  It spanned four screens here at the fornaro compound.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/29/2014 11:57 am
....
This one gave me a headache:

http://web.archive.org/web/20121107172136/http://www.cannae.com/theory-of-operation/conservation-laws

Part lecture in basic physics, part equations I can't grasp.

I'll finish with this:

http://web.archive.org/web/20121107172131/http://www.cannae.com/theory-of-operation/appendices

This stuff from Cannae and from the Chinese, that one can derive from Maxwell's equations a Lorentz force imbalance is erroneous.  What it shows is a lack of understanding of the stress tensor.

The paper by Egan correctly solves the problem of force balance not just for a truncated cone, but for any cavity shape (at the end of Egan's paper):

http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html

Yes, that's a really nice exposition.  I only wish he had taken it one step further and showed that the imbalance in an accelerating frame of reference is equal to the "weight" of the photon energy.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/29/2014 12:20 pm
Shawyer made an explanation years ago about how the thruster would develop less and less thrust the faster it was going, but the mechanism made no sense, and it still proposed to violate conservation, and the whole notion of velocity changing thrust is again, a violation of relativity.  Velocity relative to what exactly? ...snip...

I agree with that. His explanation seemed to me to require the thruster to remember the reference frame at the time of "Power on" and limit itself to accelerations that conserved everything. Maybe he was saying something else but if so, it was very obscure to me.

I don't know about his funding.
Dr. White made the same kind of mistake when describing his version of warp.  Originally he claimed that his warp notion would essentially provide a "warp boost" that allowed craft to multiply their velocity.  So warping spacetime around a craft moving 500 kps could allow it to go 5,000 kps.  The trouble came when he was asked what velocity to use.  Since velocity is relative, what he was describing was impossible.  These kinds of blunders are why you don't want people without adequate training doing your gravity physics for you.
Title: Re: EM Drive Developments
Post by: zen-in on 10/29/2014 01:01 pm
Zen-in:

Step by step photo's with explanations as to how this device was fabricated:

http://web.archive.org/web/20121005004712/http://www.cannae.com/proof-of-concept/experimental-results/2-uncategorised/30-appendix-d


Yes, that makes more sense.   The diagrams I have seen up til now would not work.  But the dewar construction looks like it would result in a low hold time (length of time before all the Helium has evaporated) because there is too much thermal leak from the liquid Nitrogen to the liquid Helium.   It's also very hard to differentiate between the thrust created by escaping cryogens and thrust created by an em effect.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/29/2014 01:01 pm
...
Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code.  I'll be back with the correct result

Yes, any tau>0.2 sec is clearly discernable.

For tau ~ 1 sec the difference is unacceptable

I'll post some pictures tomorrow after I double check everything.   I need to do some work for which I get real $$$ first  :)

All right. I'm a bit surprised then. Maybe not 7s but 2s seemed like possible to me (with eyeballs used to look at basic second order ringing oscillators).

Eagleworks inverted torsional pendulum response to exponentially decaying forcing functions (force in Newtons)

 © Rodal 2014  :)


Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{0,t>= 30}}],tau=0,0.5,1,2,3

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=0,0.5,1,2,3

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=2

Okay, I see, even with short rise times there is not enough "hit" to ring the bell, so to speak.


Note to John: I'm trying hard to express myself without using profanity but remember I'm operating on a non native language here, so my "English emulated mode" is both slower and might appear clumsy, or even "syntax erroneous" at times. I hope the ideas get through.


I still see a qualitative difference in the graphs Obs(t) though : the amplitude of ringing seem to imply a very fast rising time, but we see in your simulated curves that the first ridge of the ringing (the overshoot)  is farther to the later stable level of .00001 than the second ridge. First overshoot is .000005 above, second is less than .000003 below  (black curve, tau = 0). In the experimental graphs, figure 19, matter is complicated by the drifting baseline but this magnitude difference (relative to the "flat" level after) is not at all seen for the thrust pulses, while it is seen (more or less) for the calibration pulses where we are sure the rise time tau is 0.

If going to the third ridge (sorry this is impractical for me to draw pictures right now) that is the second ringing above (that is, one natural period after the initial overshoot), this second overshoot above is much lower the first (say .000005 for the first, 0.0000015 for the second). Again this is far from obvious in the experimental graphs of figure 19. while it appears more clearly (not perfectly) for the calibration pulses.

On the experimental graphs, If I try visually (I know, this can be misleading) to smooth out the ringing, then I see a ramp-up of the order of one period before reaching the plateau. Hope you see that. How comes ? From the amplitude of ringing, your simulations show we should have a "hit", almost instantaneous excitation to near nominal magnitude. But my visual impression (to be studied more quantitatively) would imply something is rising more slowly, with a tau of 2s or so. Could it be that we have for Fb(t) the sum of a rectangular component of near nominal magnitude (say 75%) + a smaller component (say 25%) of tau =2s ? We already know we have a rectangular pulse component of about 10% with the DC power (at 5.6 Amps)... before we embark on why there would be on top of that a 65% fast rectangle + 25% slower rate "charge/discharge" pulse : I'd like to see, since you have the tools at hand, what shape you have with   0.75*pure_rectangle(t) + 0.25*exp_charge_discharge(t)  with various tau as you did (and maybe also trying the relative weights 0.5 0.5 and 0.9 0.1)  That would make for  3x5 = 15 curves to sieve through :)

I owe you a bear beer for the surprise of your simulated results, and learning of the explicit term "dynamic amplification factor"

Concerning the chaotic components, you say that they are 1% of the amplitude of the main modes, do you agree we have quite a lot to explain (in the experimental curves) as main mode responses first before seriously taking that into account ? Also, concerning the principal behaviour of the system (that likely gives 95% of the recorded signal) would you say it is nonlinear ? How far is it from a simple slightly underdamped harmonic oscillator of the form d²x/dt² + 2*damp_ratio*omega0*dx/dt + omega0²*x = 0 ? Would you mind sharing your model's equations ? I'm ready to sign a NDA if you wish...
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/29/2014 01:15 pm
I'm trying hard to express myself ...

It was an onomatopoetic joke, youngster!  You da man!
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 01:22 pm
...
Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code.  I'll be back with the correct result

Yes, any tau>0.2 sec is clearly discernable.

For tau ~ 1 sec the difference is unacceptable

I'll post some pictures tomorrow after I double check everything.   I need to do some work for which I get real $$$ first  :)

All right. I'm a bit surprised then. Maybe not 7s but 2s seemed like possible to me (with eyeballs used to look at basic second order ringing oscillators).

Eagleworks inverted torsional pendulum response to exponentially decaying forcing functions (force in Newtons)

 © Rodal 2014  :)


Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{0,t>= 30}}],tau=0,0.5,1,2,3

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=0,0.5,1,2,3

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=2

Okay, I see, even with short rise times there is not enough "hit" to ring the bell, so to speak.


Note to John: I'm trying hard to express myself without using profanity but remember I'm operating on a non native language here, so my "English emulated mode" is both slower and might appear clumsy, or even "syntax erroneous" at times. I hope the ideas get through.


I still see a qualitative difference in the graphs Obs(t) though : the amplitude of ringing seem to imply a very fast rising time, but we see in your simulated curves that the first ridge of the ringing (the overshoot)  is farther to the later stable level of .00001 than the second ridge. First overshoot is .000005 above, second is less than .000003 below  (black curve, tau = 0). In the experimental graphs, figure 19, matter is complicated by the drifting baseline but this magnitude difference (relative to the "flat" level after) is not at all seen for the thrust pulses, while it is seen (more or less) for the calibration pulses where we are sure the rise time tau is 0.

If going to the third ridge (sorry this is impractical for me to draw pictures right now) that is the second ringing above (that is, one natural period after the initial overshoot), this second overshoot above is much lower the first (say .000005 for the first, 0.0000015 for the second). Again this is far from obvious in the experimental graphs of figure 19. while it appears more clearly (not perfectly) for the calibration pulses.

On the experimental graphs, If I try visually (I know, this can be misleading) to smooth out the ringing, then I see a ramp-up of the order of one period before reaching the plateau. Hope you see that. How comes ? From the amplitude of ringing, your simulations show we should have a "hit", almost instantaneous excitation to near nominal magnitude. But my visual impression (to be studied more quantitatively) would imply something is rising more slowly, with a tau of 2s or so. Could it be that we have for Fb(t) the sum of a rectangular component of near nominal magnitude (say 75%) + a smaller component (say 25%) of tau =2s ? We already know we have a rectangular pulse component of about 10% with the DC power (at 5.6 Amps)... before we embark on why there would be on top of that a 65% fast rectangle + 25% slower rate "charge/discharge" pulse : I'd like to see, since you have the tools at hand, what shape you have with   0.75*pure_rectangle(t) + 0.25*exp_charge_discharge(t)  with various tau as you did (and maybe also trying the relative weights 0.5 0.5 and 0.9 0.1)  That would make for  3x5 = 15 curves to sieve through :)

I owe you a bear beer for the surprise of your simulated results, and learning of the explicit term "dynamic amplification factor"

Concerning the chaotic components, you say that they are 1% of the amplitude of the main modes, do you agree we have quite a lot to explain (in the experimental curves) as main mode responses first before seriously taking that into account ? Also, concerning the principal behaviour of the system (that likely gives 95% of the recorded signal) would you say it is nonlinear ? How far is it from a simple slightly underdamped harmonic oscillator of the form d²x/dt² + 2*damp_ratio*omega0*dx/dt + omega0²*x = 0 ? Would you mind sharing your model's equations ? I'm ready to sign a NDA if you wish...

Well, there is a lot to answer there.  But what do you think of just modeling the impulse as a trapezoid ?

That means: a linear rise from zero at t=0 to f1 at t=t1, then a slower linear rise from f1 to f2 at t2, and then a linear fall from f2 to zero at t3?

then we can plot several trapezoids, essentially I agree that the rise to f1 is fast, followed by a slower rise to f2

From your writing I think you are seeing actually a more complicated picture, but both of us are patient (unlike others in this forum) so we could try to understand the behavior to this trapezoidal impulse first.

Concerning the chaotic motion, I find that intellectually interesting, perhaps I'll write a paper about it.

Yes, the chaotic motion for the simple impulses we studied so far is only 1%, but it is apparent to me that these researchers (and others in this field) have not taken into account nonlinear dynamics.  (If they don't have mathematical model for it, they cannot take it into account).

The interesting thing about a nonlinear dynamic system is that it may show up when people don't expect it (and they will assume that what they measure is real when it may be a "strange attractor" from the nonlinear dynamics of the inverted pendulum).  Certainly they don't understand it.


Since this forum is mainly aerospace engineers, a bad (because in this case we have strange attractors and not just instability) analogy would be of an airplane with aluminum wings in a swept-forward design.  We know that at  certain speeds it is going to experience divergence or flutter instability.  The situation with this inverted pendulum would be like such a swept-forward wing airplane flying naively thinking everything is fine because they did preliminary runs and they didn't suffer any instability.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/29/2014 03:23 pm
2) NASA Eagleworks, the Chinese, Cannae, and Shawyer (except his demo) have made measurements on constrained systems.  None of the researchers have analyzed their measurement systems to analyze whether indeed conservation of momentum is being violated.  The closest experiment to a violation of conservation of momentum is Shawyer's demo experiment, but again, the EM Drive demo is restrained and the whole setup is rotating instead of linearly accelerating.  No linear acceleration of the center of mass was measured and the measurement system was not analyzed.
It's probably worth noting that Woodward has measured the acceleration of the center of mass in his setup.  He did that last Fall when he received feedback from the Aero Corp about their concern that displacing the center of mass could have caused his readings but he and Dr. Heidi Fern showed conclusively this is not true by actually measuring that displacement.  He could have done this more accutrately with a laser vibrometer but the method he used was certainly sufficient.
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 03:59 pm
...

We should also model this

Quote from: Brady, March, White, et.al.
The null force testing indicated that there was an average null force of 9.6 micronewtons present in the as tested configuration. The presence of this null force was a result of the DC power current of 5.6 amps running in the power cable to the RF amplifier from the liquid metal contacts. This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system. The null test data is also shown in Fig. 20.

And the awful drift up and down of their "baseline".

Frobnicat, do you have any suggestion on how best to model this?  In which direction (A) torsional, B) swinging with largest rotary inertia, C) swinging with lowest rotary inertia)  is their "9.6 micronewton null force" ?
I don't think it could be torsional.  It looks (from their arrangement) like it is a B) swinging motion of the Faztek beams that gets measured as a torsional displacement because of the coupling between swinging and torsion.

If so, it should be entered into my model, rather as they do (in a sort of clumsy way) by subtracting it from their measured response (they assume linearity).
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 06:26 pm
Eagleworks inverted torsional pendulum response to exponentially decaying forcing functions (force in Newtons)

 © Rodal 2014  :)


Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{0,t>= 30}}],tau=0,0.5,1,2,3

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=0,0.5,1,2,3

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=2

Here are the phase plots for

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=0.000001

and

Piecewise[{{(80*10^(-6))*(1-Exp[-t/tau]),t<30},{(80*10^(-6))*(Exp[-(t-30)/tau]),t>= 30}}],tau=2

It is evident that the numerical solution of this system of stiff coupled nonlinear equations is smooth

(Picture the solution of the differential equation as being a dot that follows these paths)
Title: Re: EM Drive Developments
Post by: aero on 10/29/2014 06:29 pm
I need a little help here. I'm trying to get an accurate estimate of the Brady cavity dimensions so that frobnicat will have the data he needs to evaluate dimensionally accurate equation formulations for Force. Using the attached left side photo, I have used my screen pixel ruler to extract dimensions as follows.

                   x -pixels   y -pixels   pixel dist
               w-b   3             246   246.018292
               w-s   14           138   138.7083271
                   L   221             0   221
------------------------------------------
top slope   -221   57   0.257918552
bot slope   213   54   -0.253521127
taper         0.511439679

Using the right side photo I have sketched what I think the camera sees. That is, it sees a chord of the big and small ends, and foreshortened length. To estimate the degree of foreshortening, I measured the cross section of the Faztek beams circled in red on the photos. The beam near the camera measures 41 pixels on a side, and the far beams measure 25 pixels wide. I measured both diagonals of the near beam end, and both widths of the far beams. Only one measurement differed by 1 pixel.

Assuming the center of the base is equidistant from the near and far beams, (Might need to adjust this slightly)I calculate the beam width of the Faztek beam supporting the cavity corresponding to the distance from camera to axial center of the cavity to be 33.125 pixels = 1.5 inches = 3.81 cm, or 0.115018868 cm/pixel. Using this conversion I calculate the chord lengths illustrated in the attached drawing to be
   w-big chord = 28.29674543 cm
w-small chord = 15.95407475 cm
and foreshortened length = 25.41916981 cm

But I need some help calculating the actual diameters and real length. It is not a huge factor but it is probably the largest error source remaining in the estimated cavity size.



Title: Re: EM Drive Developments
Post by: Notsosureofit on 10/29/2014 07:30 pm
For what it's worth, I measure the FRP board at 0.060" and the copper cladding at 0.002". (the stuff I have here anyway)
Title: Re: EM Drive Developments
Post by: aero on 10/29/2014 07:43 pm
For what it's worth, I measure the FRP board at 0.060" and the copper cladding at 0.002". (the stuff I have here anyway)
My measurements are taken at the inside bend of the copper. The FRC boards are outside that point, but the copper cladding is inside that point. IOW extend my length by 2 * 0.002" and shorten my diameters by the same amount. That is a further correction we should make.
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 08:37 pm
I need a little help here. I'm trying to get an accurate estimate of the Brady cavity dimensions so that frobnicat will have the data he needs to evaluate dimensionally accurate equation formulations for Force. Using the attached left side photo, I have used my screen pixel ruler to extract dimensions as follows.

                   x -pixels   y -pixels   pixel dist
               w-b   3             246   246.018292
               w-s   14           138   138.7083271
                   L   221             0   221
------------------------------------------
top slope   -221   57   0.257918552
bot slope   213   54   -0.253521127
taper         0.511439679

Using the right side photo I have sketched what I think the camera sees. That is, it sees a chord of the big and small ends, and foreshortened length. To estimate the degree of foreshortening, I measured the cross section of the Faztek beams circled in red on the photos. The beam near the camera measures 41 pixels on a side, and the far beams measure 25 pixels wide. I measured both diagonals of the near beam end, and both widths of the far beams. Only one measurement differed by 1 pixel.

Assuming the center of the base is equidistant from the near and far beams, (Might need to adjust this slightly)I calculate the beam width of the Faztek beam supporting the cavity corresponding to the distance from camera to axial center of the cavity to be 33.125 pixels = 1.5 inches = 3.81 cm, or 0.115018868 cm/pixel. Using this conversion I calculate the chord lengths illustrated in the attached drawing to be
   w-big chord = 28.29674543 cm
w-small chord = 15.95407475 cm
and foreshortened length = 25.41916981 cm

But I need some help calculating the actual diameters and real length. It is not a huge factor but it is probably the largest error source remaining in the estimated cavity size.

This is not just shrinking Fornaro's dimensions but it is also changing the ratios:

Aero BigDiameter/SmallDiameter =  28.29674543 /  15.95407475 = 1.77

Fornaro BigDiameter/SmallDiameter = 39.7/24.4 = 1.63

Difference=9%

Aero CavityLength/SmallDiameter = 25.41916981 /  15.9540747 = 1.59

Fornaro CavityLength/SmallDiameter = 33.2 /24.4= 1.36

Difference=17%

Aero CavityLength/BigDiameter= 25.41916981 /  28.29674543 = 0.898

Fornaro CavityLength/BigDiameter= 33.2 /39.7 = 0.836

Difference= 7%

The most significant change is the ratio CavityLength/SmallDiameter
Title: Re: EM Drive Developments
Post by: frobnicat on 10/29/2014 09:44 pm
...

We should also model this

Quote from: Brady, March, White, et.al.
The null force testing indicated that there was an average null force of 9.6 micronewtons present in the as tested configuration. The presence of this null force was a result of the DC power current of 5.6 amps running in the power cable to the RF amplifier from the liquid metal contacts. This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system. The null test data is also shown in Fig. 20.

And the awful drift up and down of their "baseline".

Frobnicat, do you have any suggestion on how best to model this?  In which direction (A) torsional, B) swinging with largest rotary inertia, C) swinging with lowest rotary inertia)  is their "9.6 micronewton null force" ?
I don't think it could be torsional.  It looks (from their arrangement) like it is a B) swinging motion of the Faztek beams that gets measured as a torsional displacement because of the coupling between swinging and torsion.

If so, it should be entered into my model, rather as they do (in a sort of clumsy way) by subtracting it from their measured response (they assume linearity).

At the moment I do ask a lot of questions and don't answer a lot. Have to say I still don't have a good picture of the torsion pendulum geometry and where gizmos are relative to pivot (save the thruster).

Time to get a better understanding : from figure 1, left picture, we have a gantry that's static, along the vertical left "leg" of this gantry there are two flexure bearing with vertical axis, on the right picture we can only see the upper one, as two dark grey bloc and I guess the "spring foils" are hidden in the cylindrical space between them. Is that it ?

So essentially we have a vertical pivot on the left of the diamond shaped plate (second picture figure 17)  that's fixed on the right of the horizontal rotating arm, so that pivot axis is roughly centered in the middle of the faztek arm. This pivot has a linear restoring torque proportional to angular deviation from rest position. On the right of the upper part of vertical plate that links the arm to the flexure bearings there is a connecting box, this box will move with the arm. 

The static gantry is on three height adjustable (and vibration isolating ?) platforms so that the axis can be set a good vertical I guess. The oblique horizontal faztek linking the arm to the right leg of the gantry is seen on some pictures, not others; I guess it is used to fasten the rotating arm when mounting things and then removed for measures.

Figure 1 picture left : the liquid contacts system is the thing on top of the gantry, on the left, above the flexure bearings (aligned with axis of rotation ?). On figure 6 the upper white board is fixed to the gantry, the white board below (with cut angles) is the part that moves with the arm. It is somehow mechanically and electrically connected to the connecting box below.

We see the damping system on the third picture of figure 17 : it is situated at the back of the arm, below the amplifier. When the arm rotates, the "fin" enter and leaves the space between the strong magnets : figure 3 second picture the view is lateral to the arm, the plunging "fin" is fixed to back end of arm, it goes forward backward relative to the view. The permanent magnets are enclosed in a ferromagnetic U trying to close the circuit.

It's tempting to see the leaks of this magnetic circuit as a dipole with axis roughly aligned with arm. Hard to tell from the pictures (maybe with an added hour of eye straining ...) where is the cable that goes from the liquid contacts, above the axis, to the RF amplifier, back of the arm. Could be in the same plane, vertical plane defined by the arm. And magnetic field lines would be parallel to this plane (that needs to be checked, the U closing the magnetic circuit is not symmetric relative to that plane). That would give a cross product ILxB force directed orthogonal to that vertical plane above the arm.

Ok lets say, the arm is axis x positive front (thruster)  negative back (RF amplifier and magnets). The y axis is orthogonal, going to the right, the z axis is upward. And origin at the middle of the arm, at the axis of rotation. I would say the spurious DC force is along the y direction, applied somewhere between the wet contacts above the origin at x=y=0 z=+something and the amplifier at x=-something y=0 z=+not_much

If you could confirm my x y z link to your A B C :
A) torsional : rotation around z axis ?
B) swinging with largest rotary inertia : rotation around y axis ?
C) swinging with lowest rotary inertia) : rotation around x axis ?

The B and C modes would be very stiff (similar stiffness)
The A and B modes would have similar moment of inertia
The flexure bearings would introduce some level of coupling between the 3 angles + 3 displacements, is that where you get the nonlinearities ?

From this line of reasonning the DC spurious force would have a direct torque around the z (mode A) and x (mode C) axis. Just the opposite of what you said :)

Only... isn't a DC current supposed to go and come back ? A twisted pair would in principle suffice to neutralize any net imbalance. Only when the cables separate we have a loop with coupling to magnetic field. So, where the cables separate (at the wet contacts box? inside the amplifier?) and at what angle in what plane ? Short of those answers, best guess is to take into account only what goes into A mode and discard the chaotic aspects of A B C coupling.

So, in the end, for the principal dynamic activity of the balance around A, at 99% we have a simple (under)damped harmonic oscillator no ? What is the force vs speed function of a magnetic damper ?



Title: Re: EM Drive Developments
Post by: frobnicat on 10/29/2014 10:01 pm

Well, there is a lot to answer there.  But what do you think of just modeling the impulse as a trapezoid ?

That means: a linear rise from zero at t=0 to f1 at t=t1, then a slower linear rise from f1 to f2 at t2, and then a linear fall from f2 to zero at t3?

then we can plot several trapezoids, essentially I agree that the rise to f1 is fast, followed by a slower rise to f2

From your writing I think you are seeing actually a more complicated picture, but both of us are patient (unlike others in this forum) so we could try to understand the behavior to this trapezoidal impulse first.

I understand you see a piecewise linear function as the default way to introduce more (not too much) parameters to fit the target data. It's ok for me.

From my "more complicated picture" that will take many hours to just utter  (a chance that you are patient !) I still suggest rectangle plus exp "charge/discharge". If piecewise linear it would rather look like :

     ______
    /      |
____|      \_______


I'm a big fan of chaotic swing too, but right now I'm on an agenda with lower Lyapunov exponent.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 10/29/2014 10:02 pm
Only... isn't a DC current supposed to go and come back ? A twisted pair would in principle suffice to neutralize any net imbalance. Only when the cables separate we have a loop with coupling to magnetic field. So, where the cables separate (at the wet contacts box? inside the amplifier?) and at what angle in what plane ?
Since they claim to know they have b field coupling, one presumes they waved some Mu metal between or some such.  It wouldn't be the first time a twisted pair produced a noticeable force and these are very small forces.
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 10:59 pm
...

We should also model this

Quote from: Brady, March, White, et.al.
The null force testing indicated that there was an average null force of 9.6 micronewtons present in the as tested configuration. The presence of this null force was a result of the DC power current of 5.6 amps running in the power cable to the RF amplifier from the liquid metal contacts. This current causes the power cable to generate a magnetic field that interacts with the torsion pendulum magnetic damper system. The null test data is also shown in Fig. 20.

And the awful drift up and down of their "baseline".

Frobnicat, do you have any suggestion on how best to model this?  In which direction (A) torsional, B) swinging with largest rotary inertia, C) swinging with lowest rotary inertia)  is their "9.6 micronewton null force" ?
I don't think it could be torsional.  It looks (from their arrangement) like it is a B) swinging motion of the Faztek beams that gets measured as a torsional displacement because of the coupling between swinging and torsion.

If so, it should be entered into my model, rather as they do (in a sort of clumsy way) by subtracting it from their measured response (they assume linearity).

At the moment I do ask a lot of questions and don't answer a lot. Have to say I still don't have a good picture of the torsion pendulum geometry and where gizmos are relative to pivot (save the thruster).

Time to get a better understanding : from figure 1, left picture, we have a gantry that's static, along the vertical left "leg" of this gantry there are two flexure bearing with vertical axis, on the right picture we can only see the upper one, as two dark grey bloc and I guess the "spring foils" are hidden in the cylindrical space between them. Is that it ?

So essentially we have a vertical pivot on the left of the diamond shaped plate (second picture figure 17)  that's fixed on the right of the horizontal rotating arm, so that pivot axis is roughly centered in the middle of the faztek arm. This pivot has a linear restoring torque proportional to angular deviation from rest position. On the right of the upper part of vertical plate that links the arm to the flexure bearings there is a connecting box, this box will move with the arm. 

The static gantry is on three height adjustable (and vibration isolating ?) platforms so that the axis can be set a good vertical I guess. The oblique horizontal faztek linking the arm to the right leg of the gantry is seen on some pictures, not others; I guess it is used to fasten the rotating arm when mounting things and then removed for measures.

Figure 1 picture left : the liquid contacts system is the thing on top of the gantry, on the left, above the flexure bearings (aligned with axis of rotation ?). On figure 6 the upper white board is fixed to the gantry, the white board below (with cut angles) is the part that moves with the arm. It is somehow mechanically and electrically connected to the connecting box below.

We see the damping system on the third picture of figure 17 : it is situated at the back of the arm, below the amplifier. When the arm rotates, the "fin" enter and leaves the space between the strong magnets : figure 3 second picture the view is lateral to the arm, the plunging "fin" is fixed to back end of arm, it goes forward backward relative to the view. The permanent magnets are enclosed in a ferromagnetic U trying to close the circuit.

It's tempting to see the leaks of this magnetic circuit as a dipole with axis roughly aligned with arm. Hard to tell from the pictures (maybe with an added hour of eye straining ...) where is the cable that goes from the liquid contacts, above the axis, to the RF amplifier, back of the arm. Could be in the same plane, vertical plane defined by the arm. And magnetic field lines would be parallel to this plane (that needs to be checked, the U closing the magnetic circuit is not symmetric relative to that plane). That would give a cross product ILxB force directed orthogonal to that vertical plane above the arm.

Ok lets say, the arm is axis x positive front (thruster)  negative back (RF amplifier and magnets). The y axis is orthogonal, going to the right, the z axis is upward. And origin at the middle of the arm, at the axis of rotation. I would say the spurious DC force is along the y direction, applied somewhere between the wet contacts above the origin at x=y=0 z=+something and the amplifier at x=-something y=0 z=+not_much

If you could confirm my x y z link to your A B C :
A) torsional : rotation around z axis ?
B) swinging with largest rotary inertia : rotation around y axis ?
C) swinging with lowest rotary inertia) : rotation around x axis ?

The B and C modes would be very stiff (similar stiffness)
The A and B modes would have similar moment of inertia
The flexure bearings would introduce some level of coupling between the 3 angles + 3 displacements, is that where you get the nonlinearities ?

From this line of reasonning the DC spurious force would have a direct torque around the z (mode A) and x (mode C) axis. Just the opposite of what you said :)

Only... isn't a DC current supposed to go and come back ? A twisted pair would in principle suffice to neutralize any net imbalance. Only when the cables separate we have a loop with coupling to magnetic field. So, where the cables separate (at the wet contacts box? inside the amplifier?) and at what angle in what plane ? Short of those answers, best guess is to take into account only what goes into A mode and discard the chaotic aspects of A B C coupling.

So, in the end, for the principal dynamic activity of the balance around A, at 99% we have a simple (under)damped harmonic oscillator no ? What is the force vs speed function of a magnetic damper ?

the arm is axis x positive front (thruster)  negative back (RF amplifier and magnets).
The y axis is orthogonal, going to the right,
the z axis is upward.

alpha=rotation around x axis
beta=rotation around y axis
gamma=rotation around z axis


OK let me answer one important question at the outset: where does the coupling come from.

The coupling comes from this nasty fact:

if you have a force applied at the origin along the x axis, it will be produce a swinging beta rotation around the y axis

if you have a force applied at the origin along the y axis, it will be produce a swinging alpha rotation around the x axis


if you have a force applied at the end of the x arm, oriented along the y axis, it will produce a gamma rotation around the z axis, but also (because of the above facts) one has nonlinear coupling:

alphaDot =  d alpha /dt
alphaDotDot = d2  alpha /dt2

In the equations of motion for the gamma rotation around the z axis one also gets contributions from a number of terms, the most important ones being the following rates:  alphaDot * betaDot  and another contribution from beta * alphaDotDot

I obtained the 3-dimensional, nonlinearly coupled equations of motion by solving the Lagrangian.

Please notice that while the department of Aeronautics and Astronautics at MIT has an inverted pendulum designed at MIT to eliminate this coupling (only linear x and y motions are allowed for the thruster), NASA Eagleworks neglected to eliminate this coupling. 

The department of Aeronautics and Astronautics at MIT has been a leader in nonlinear dynamics for the last century (starting with the problems of flutter and divergence and self-excited oscillations).
Title: Re: EM Drive Developments
Post by: Rodal on 10/29/2014 11:29 pm

Well, there is a lot to answer there.  But what do you think of just modeling the impulse as a trapezoid ?

That means: a linear rise from zero at t=0 to f1 at t=t1, then a slower linear rise from f1 to f2 at t2, and then a linear fall from f2 to zero at t3?

then we can plot several trapezoids, essentially I agree that the rise to f1 is fast, followed by a slower rise to f2

From your writing I think you are seeing actually a more complicated picture, but both of us are patient (unlike others in this forum) so we could try to understand the behavior to this trapezoidal impulse first.

I understand you see a piecewise linear function as the default way to introduce more (not too much) parameters to fit the target data. It's ok for me.

From my "more complicated picture" that will take many hours to just utter  (a chance that you are patient !) I still suggest rectangle plus exp "charge/discharge". If piecewise linear it would rather look like :

     ______
    /      |
____|      \_______


I'm a big fan of chaotic swing too, but right now I'm on an agenda with lower Lyapunov exponent.

f=0   @ t=0
f=f1  @ t=t1
f=f2  @ t=t2
f=f2  @ t=t3
f=f3  @ t=t4
f=0   @ t=t5

Please give me f1, f2,f3 and t1,t2,t3,t4,t5 you would like

f1 = f2 - f3  therefore f3 = f2 - f1  ?

t1 = t4 - t3 therefore t4 = t1 + t3  ?

t2 - t1 = t5 - t4 therefore t5 = t2 + t3  ?

therefore,

need f1, f2,  and t1,t2,t3


Title: Re: EM Drive Developments
Post by: Rodal on 10/30/2014 02:34 am
Title: Re: EM Drive Developments
Post by: Rodal on 10/30/2014 02:34 am
....
From this line of reasonning the DC spurious force would have a direct torque around the z (mode A) and x (mode C) axis. Just the opposite of what you said :)
....

Based on my memory of their setup, I am not following your line of reasoning here.  Let me go back to Brady's report and check whether I remember correctly their setup.

Figure 3 shows the magnetic damper

One can see a porthole that is on a line perpendicular to the beam attached to the magnetic damper

The portholes are on the sides of the chamber

Therefore the magnetic damper is connected to the beam that runs longitudinally along the length of the chamber.  Therefore the magnetic damper is connected to a beam that runs along the x axis.

If that beam running along the x axis goes through the center of rotation, the force oriented along direction x cannot produce a torque along the z axis, because the direction of the force will go through the center of torsional rotation.

A force directed along the x axis produces a swinging rotation "beta" around the y axis,  swinging with largest rotary inertia.


                                                                                         <-------------  X direction

                     

Y axis perpendicular to this page     


                                                                                              (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=618570;image)

           <--
       /           \                                                                 
beta rotation l                       
Title: Re: EM Drive Developments
Post by: aero on 10/30/2014 03:14 am
I'm getting really tired of looking at these pictures so I'm going to join John after I post what I've found today.

See http://forum.nasaspaceflight.com/index.php?topic=29276.msg1279371#msg1279371 (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1279371#msg1279371) for background and photos.

Pinhole projection formula         x/f = X/S   
where            
x1 = object size on photo 1         25   px
x2 = object size on photo 2         41   px
f = focal length            
X = object real size               3.81   cm
d1 = distance from camera to object, photo 1            
S = distance between 1 and 2         31.12641998   cm
which I assumed as 1.1 times the w-big chord.
then            
d1=S*x2/(x2-x1)            
   d1=   79.76145119   cm   so the distance to the center of the base plate, dc, is d1 - 0.6* w-big chord
dc = 62.78340393 cm
            
With that, using alpha = 2* arctan(w-big chord/2*dc) you can calculate the angle subtended by the w-big chord then it is just a matter of using right triangles to calculate the real radius, big and small, then scale the length proportionately. Note that this will make a very noticeable difference in cavity size.

Errors that I know about: When I calculated the scale factor I assumed the two reference beams were equidistant from the center of the base. Closer inspection leads me to think that the beam in front is aligned with the front of edge of the base, but the beam in back is separated from the edge of the base by about 0.1 diameters of the base. I have used that observation here, but it needs to be looked at by younger eyes then fitted into the estimate of the scale factor made in my previous post. That will adjust all dimensions of the cavity. After that, re-do this part of course.

Maybe I'll feel like doing more after I get some feed back regarding beam location and separation estimated in units of big end diameters. Or cm, if you like.
Title: Re: EM Drive Developments
Post by: ThinkerX on 10/30/2014 04:04 am
I am starting to wonder if the 'EM Drive' is not so much 'generating thrust' but rather trying to 'hitch a ride' on the expansive force of the universe, be it 'Dark Energy' or the 'Cosmological Constant' or something else. 

The tiny bit of info I could grasp about Dark Energy is astonishing: a force large enough to overcome the gravitational attraction between galaxies (!) forcing them apart at a continuous acceleration on the order of 1 km/sec per kilo parsec (!)  A force that grows over time rather than diminishes?   Regardless of the exact mechanism, the observed astronomical effects are real on the macroscopic scale, which to me implies they must be real at the local level as well, if much diminished for whatever reason. 

From the tiny bit of the papers I could actually understand, it seems like the theorist are highly uncomfortable with the measures required to fit Dark Energy, in any form, into the scheme of physics.  Multiple tepid explanations. 

One oddity:  Despite its name, the 'Cosmological Constant' invoked to help explain Dark Energy is a variable, not a fixed number, PLUS one of the major EM Drives is that the frequency the various experimental groups are trying to hit is also a variable.  Wonder if there could be a direct or indirect connection there: the experimenters hit the right frequency in a container with the right dimensions, and Dark Energy comes calling.  Or did I just reinvent the wheel here?

Almost like Dark Energy doesn't play well with other universal forces, which tells me about the only way to verify this effect would be in space - preferably way out in space, away from other influences.

Bizarre hypothetical or question:  if you could somehow generate Dark Energy inside a sealed container, would the laws of thermodynamics, especially conservation of motion, still apply?  Would they still apply if Dark Energy was interacting with another force inside the sealed container?  Or did I just reinvent the wheel again?

Ok...time for the rest of you to post the cute videos demonstrating how deep of a hole I dug for myself this time...
Title: Re: EM Drive Developments
Post by: frobnicat on 10/30/2014 08:29 am

Well, there is a lot to answer there.  But what do you think of just modeling the impulse as a trapezoid ?

That means: a linear rise from zero at t=0 to f1 at t=t1, then a slower linear rise from f1 to f2 at t2, and then a linear fall from f2 to zero at t3?

then we can plot several trapezoids, essentially I agree that the rise to f1 is fast, followed by a slower rise to f2

From your writing I think you are seeing actually a more complicated picture, but both of us are patient (unlike others in this forum) so we could try to understand the behavior to this trapezoidal impulse first.

I understand you see a piecewise linear function as the default way to introduce more (not too much) parameters to fit the target data. It's ok for me.

From my "more complicated picture" that will take many hours to just utter  (a chance that you are patient !) I still suggest rectangle plus exp "charge/discharge". If piecewise linear it would rather look like :

     ______
    /      |
____|      \_______


I'm a big fan of chaotic swing too, but right now I'm on an agenda with lower Lyapunov exponent.

f=0   @ t=0
f=f1  @ t=t1
f=f2  @ t=t2
f=f2  @ t=t3
f=f3  @ t=t4
f=0   @ t=t5

Please give me f1, f2,f3 and t1,t2,t3,t4,t5 you would like

f1 = f2 - f3  therefore f3 = f2 - f1  ?

t1 = t4 - t3 therefore t4 = t1 + t3  ?

t2 - t1 = t5 - t4 therefore t5 = t2 + t3  ?

therefore,

need f1, f2,  and t1,t2,t3

Not much time, a mountain is waiting for my feet :
f=0   @ t=0-
f=80(1-ssr)  @ t=0+  (instantaneous rise)
f=80  @ t=tau
f=80  @ t=30-
f=80ssr  @ t=30+ (instantaneous fall)
f=0   @ t=30+tau

only two free running parameters : tau for the slow component and ssr = smooth/sharp ratio
let's try  ssr = .4  .2  .1
together with
tau = 0.25  0.5  1   2   4

more later about x y z
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/30/2014 11:13 am
Ok...time for the rest of you to post the cute videos demonstrating how deep of a hole I dug for myself this time...

We aim to please:

http://www.youtube.com/watch?v=a-9PqUQwVJw
Title: Re: EM Drive Developments
Post by: Rodal on 10/30/2014 03:45 pm

Well, there is a lot to answer there.  But what do you think of just modeling the impulse as a trapezoid ?

That means: a linear rise from zero at t=0 to f1 at t=t1, then a slower linear rise from f1 to f2 at t2, and then a linear fall from f2 to zero at t3?

then we can plot several trapezoids, essentially I agree that the rise to f1 is fast, followed by a slower rise to f2

From your writing I think you are seeing actually a more complicated picture, but both of us are patient (unlike others in this forum) so we could try to understand the behavior to this trapezoidal impulse first.

I understand you see a piecewise linear function as the default way to introduce more (not too much) parameters to fit the target data. It's ok for me.

From my "more complicated picture" that will take many hours to just utter  (a chance that you are patient !) I still suggest rectangle plus exp "charge/discharge". If piecewise linear it would rather look like :

     ______
    /      |
____|      \_______


I'm a big fan of chaotic swing too, but right now I'm on an agenda with lower Lyapunov exponent.

f=0   @ t=0
f=f1  @ t=t1
f=f2  @ t=t2
f=f2  @ t=t3
f=f3  @ t=t4
f=0   @ t=t5

Please give me f1, f2,f3 and t1,t2,t3,t4,t5 you would like

f1 = f2 - f3  therefore f3 = f2 - f1  ?

t1 = t4 - t3 therefore t4 = t1 + t3  ?

t2 - t1 = t5 - t4 therefore t5 = t2 + t3  ?

therefore,

need f1, f2,  and t1,t2,t3

Not much time, a mountain is waiting for my feet :
f=0   @ t=0-
f=80(1-ssr)  @ t=0+  (instantaneous rise)
f=80  @ t=tau
f=80  @ t=30-
f=80ssr  @ t=30+ (instantaneous fall)
f=0   @ t=30+tau

only two free running parameters : tau for the slow component and ssr = smooth/sharp ratio
let's try  ssr = .4  .2  .1
together with
tau = 0.25  0.5  1   2   4

more later about x y z

Results for

Piecewise[{
{(80*10^(-6))*(1 - ssr (1 - t/tau)), t <= tau}, {(80*10^(-6)), t <  30},
{(80*10^(-6))*(ssr/tau)*(30 + tau - t), t <= 30 + tau}
                }]

We see the effect of tau and ssr modifying mainly the dynamic magnification factor, as expected.


Varying tau at constant ssr

ssr=0.4 tau = 0, 1,2,3,4,5

ssr=0.4 tau = 4

Note: there are diminishing returns on this effect for tau >3



Varying ssr at constant tau

ssr=0, 0.25, 0.50, 0.75, 1.00 tau = 4

ssr=0.5 tau = 4

Note: ssr close to 1 effectively "kills" the dynamic magnification factor (the "first ring" in Fornaro vernacular) without much affecting the second ring



Title: Re: EM Drive Developments
Post by: Rodal on 10/30/2014 06:29 pm
Ok...time for the rest of you to post the cute videos demonstrating how deep of a hole I dug for myself this time...

We aim to please:

Can you see a sextupole perturbation in the resonant excitation of the EM Drive ?
Title: Re: EM Drive Developments
Post by: Rodal on 10/30/2014 08:21 pm

Well, there is a lot to answer there.  But what do you think of just modeling the impulse as a trapezoid ?

That means: a linear rise from zero at t=0 to f1 at t=t1, then a slower linear rise from f1 to f2 at t2, and then a linear fall from f2 to zero at t3?

then we can plot several trapezoids, essentially I agree that the rise to f1 is fast, followed by a slower rise to f2

From your writing I think you are seeing actually a more complicated picture, but both of us are patient (unlike others in this forum) so we could try to understand the behavior to this trapezoidal impulse first.

I understand you see a piecewise linear function as the default way to introduce more (not too much) parameters to fit the target data. It's ok for me.

From my "more complicated picture" that will take many hours to just utter  (a chance that you are patient !) I still suggest rectangle plus exp "charge/discharge". If piecewise linear it would rather look like :

     ______
    /      |
____|      \_______


I'm a big fan of chaotic swing too, but right now I'm on an agenda with lower Lyapunov exponent.

f=0   @ t=0
f=f1  @ t=t1
f=f2  @ t=t2
f=f2  @ t=t3
f=f3  @ t=t4
f=0   @ t=t5

Please give me f1, f2,f3 and t1,t2,t3,t4,t5 you would like

f1 = f2 - f3  therefore f3 = f2 - f1  ?

t1 = t4 - t3 therefore t4 = t1 + t3  ?

t2 - t1 = t5 - t4 therefore t5 = t2 + t3  ?

therefore,

need f1, f2,  and t1,t2,t3

Not much time, a mountain is waiting for my feet :
f=0   @ t=0-
f=80(1-ssr)  @ t=0+  (instantaneous rise)
f=80  @ t=tau
f=80  @ t=30-
f=80ssr  @ t=30+ (instantaneous fall)
f=0   @ t=30+tau

only two free running parameters : tau for the slow component and ssr = smooth/sharp ratio
let's try  ssr = .4  .2  .1
together with
tau = 0.25  0.5  1   2   4

more later about x y z

Results for

Piecewise[{{(80*10^(-6))*(1 - ssr (1 - t/tau)),
   t <= tau}, {(80*10^(-6)),
   t <  30}, {(80*10^(-6))*(ssr/tau)*(30 + tau - t), t <= 30 + tau}}]

We see the effect of tau and ssr modifying mainly the dynamic magnification factor, as expected.


Varying tau at constant ssr

ssr=0.4 tau = 0, 1,2,3,4,5

ssr=0.4 tau = 4

Note: there are diminishing returns on this effect for tau >3



Varying ssr at constant tau

ssr=0, 0.25, 0.50, 0.75, 1.00 tau = 4

ssr=0.5 tau = 4

Note: ssr close to 1 effectively "kills" the dynamic magnification factor (the "first ring" in Fornaro vernacular) without much affecting the second ring



Here is the decaying exponential study:

Piecewise[{
{(80*10^(-6))*(1-ssr)+(80*10^(-6))*ssr*(1-Exp[-t/tau])/(1-Exp[-30/tau]),t<30},
{(80*10^(-6))*ssr*(Exp[-(t-30)/tau]),t>= 30}
                }]

Varying ssr at constant tau

ssr=0, 0.25, 0.50, 0.75, 1.00 tau = 4

ssr=0.5 tau = 4

Note: ssr close to 1

A) The piecewise linear forcing function effectively "kills" the dynamic magnification factor (the "first ring") without much affecting the second ring

B) The exponential decay forcing function (controlling only the initial force through ssr) kills the dynamic magnification factor as well as affecting the other rings




Varying tau at constant ssr

Piecewise[{
{(80*10^(-6))*(1-ssr)+(80*10^(-6))*ssr*(1-Exp[-t/tau])/(1-Exp[-30/tau]),t<30},
{(80*10^(-6))*ssr*(Exp[-(t-30)/tau]),t>= 30}
               }]

ssr=0.4 tau = 0, 1,2,3,4,5

ssr=0.4 tau = 4

Title: Re: EM Drive Developments
Post by: Rodal on 10/30/2014 08:46 pm
The actual response of Eagleworks does look something like this response to this  impulse + exponentially decaying rise forcing function:

Piecewise[{
{(80*10^(-6))*(1-ssr)+(80*10^(-6))*ssr*(1-Exp[-t/tau])/(1-Exp[-30/tau]),t<30},
{(80*10^(-6))*ssr*(Exp[-(t-30)/tau]),t>= 30}
                }]

ssr=0.4

tau=4 seconds
Title: Re: EM Drive Developments
Post by: frobnicat on 10/30/2014 08:48 pm
.../...
So, in the end, for the principal dynamic activity of the balance around A, at 99% we have a simple (under)damped harmonic oscillator no ? What is the force vs speed function of a magnetic damper ?

the arm is axis x positive front (thruster)  negative back (RF amplifier and magnets).
The y axis is orthogonal, going to the right,
the z axis is upward.

All right, let's stick with this simple right handed system. Let's say the origin O is where the main axis of rotation of the flexure bearings meets the axis of the faztek moving beam.

Quote
alpha=rotation around x axis
beta=rotation around y axis
gamma=rotation around z axis


OK let me answer one important question at the outset: where does the coupling come from.

The coupling comes from this nasty fact:

if you have a force applied at the origin along the x axis, it will be produce a swinging beta rotation around the y axis

if you have a force applied at the origin along the y axis, it will be produce a swinging alpha rotation around the x axis

er, a force applied at the origin has no torque... I see a force along the x axis anywhere but on the y axis has torque for beta rotation, but that could be said also of any vector that don't cross the y axis. Only a force vector within Oxz plane has "pure" beta torque and no torque on the others. Is that what you mean by "applied at the origin" ?

Quote
if you have a force applied at the end of the x arm, oriented along the y axis, it will produce a gamma rotation around the z axis, but also (because of the above facts) one has nonlinear coupling:

to be clear, a force applied at x=end_of_arm  y=whatever  z=thruster_axis_height  along the y axis will have a torque relative to gamma and alpha.

Quote
alphaDot =  d alpha /dt
alphaDotDot = d2  alpha /dt2

In the equations of motion for the gamma rotation around the z axis one also gets contributions from a number of terms, the most important ones being the following rates:  alphaDot * betaDot  and another contribution from beta * alphaDotDot

I obtained the 3-dimensional, nonlinearly coupled equations of motion by solving the Lagrangian.

Please notice that while the department of Aeronautics and Astronautics at MIT has an inverted pendulum designed at MIT to eliminate this coupling (only linear x and y motions are allowed for the thruster), NASA Eagleworks neglected to eliminate this coupling. 

The department of Aeronautics and Astronautics at MIT has been a leader in nonlinear dynamics for the last century (starting with the problems of flutter and divergence and self-excited oscillations).

So you have 6 dynamical DOF with alpha beta gamma alphaDot betaDot gammaDot, is that it ?
Wouldn't the "centre" xc yc zc of the beam, initially at O,  also have some small but significant displacements and coupling with the rotation ? After all, for rotations alpha and beta to be considered means that the 2 flexure bearing can see their axis shift from their rest position. That would add another 6 dynamical DOF, xc yc zc and xcDot ycDot zcDot. Negligible ? More negligible than the first modes of vibration of the beam (if it is no longer considered a perfect solid) ?

I understand you are on the investigation of those complex dynamics, and those aspects need to be addressed to either discard or include them as sources of spurious measures (or wrong interpretations of readings). I can only encourage such endeavour. But I see that it will need a lot more geometric data to incorporate the y oriented forces (or not perfectly y oriented) with their x y z position to yield relevant results from such a sophisticated model.

At the moment, my personal line of inquiry would be happy with a 2 DOF dynamical model gamma and gammaDot and I'm assuming a simple harmonic (under)damped oscillator for now. As to answer my later question "What is the force vs speed function of a magnetic damper ?" I understand from the oracle (http://en.wikipedia.org/wiki/Magnetic_damping) that we have a linear Fdamp = -K v like a classical simple viscous damping (on first approximation).

I'm still very interested in your further inquiries around the mechanical system as a whole (with more DOF) and in particular if it could illuminate the presence of a significant "background level" of natural freq oscillations in spite of the damper. For instance figure 19, first picture, first calibration pulse, we expect an exponential decay of ringing amplitude but we see the ringing going on much longer... it's like there is a permanent level of excitation of the system. The experiment is sensitive, so it will have some level of "noise" but it would be interesting to know where this noise comes from, and short of that, could we take that explicitly into account to "subtract" this background ringing contribution, how ?
Title: Re: EM Drive Developments
Post by: frobnicat on 10/30/2014 09:10 pm
....
From this line of reasonning the DC spurious force would have a direct torque around the z (mode A) and x (mode C) axis. Just the opposite of what you said :)
....

Based on my memory of their setup, I am not following your line of reasoning here.  Let me go back to Brady's report and check whether I remember correctly their setup.

Figure 3 shows the magnetic damper

One can see a porthole that is on a line perpendicular to the beam attached to the magnetic damper

The portholes are on the sides of the chamber

Therefore the magnetic damper is connected to the beam that runs longitudinally along the length of the chamber.  Therefore the magnetic damper is connected to a beam that runs along the x axis.

If that beam running along the x axis goes through the center of rotation, the force oriented along direction x cannot produce a torque along the z axis, because the direction of the force will go through the center of torsional rotation.

A force directed along the x axis produces a swinging rotation "beta" around the y axis,  swinging with largest rotary inertia.


                                                                                         <-------------  X direction

                     

Y axis perpendicular to this page     


                                                                                              (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=618570;image)

           <--
       /           \                                                                 
beta rotation l                       

Why would that give an x axis force more that a z axis force ? This is a non magnetic plunger in a field that's oriented Ox, force are only with movement, so if main movement is along y axis, main force would be y axis (damping main gamma rotation). If small moves along x, I don't see much force from that since you are moving essentially parallel to field lines. Maybe z move would give more z oriented force (torque around, er, beta also, but with a better "lever")

Anyhow, I was talking about the DC spurious force of 9µN or so of current interaction with B of magnets, saying that a wire that's roughly (from the wet contacts to the amplifier) in Oxz, that a magnetic dipole around the x axis would have field lines parallel to Oxz in this plane, and that the force would be directed along y, hence a torque around gamma and alpha, but not beta. But since it all depends on the exact geometry of the 2 wires and of the B gradient, I guess we are stuck : basically we don't know the place of the vector, just its contribution as torque around gamma. So, sad as it is, subtracting this "DC component" is best we can do save a visit at Eagleworks and dismantling of amplifier.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/30/2014 09:31 pm
Only... isn't a DC current supposed to go and come back ? A twisted pair would in principle suffice to neutralize any net imbalance. Only when the cables separate we have a loop with coupling to magnetic field. So, where the cables separate (at the wet contacts box? inside the amplifier?) and at what angle in what plane ?
Since they claim to know they have b field coupling, one presumes they waved some Mu metal between or some such.  It wouldn't be the first time a twisted pair produced a noticeable force and these are very small forces.
There is no such thing as passive perfect permanent B field shielding, is there ? The magnets are very strong, they are just below (10cm ?) the amplifier that receive the DC wires. I have no precise idea of the leaked B but the gaps in the magnetic circuit are huge, my guess would be around .1T. On a gradient of .001T per distance between + and - plugs, suffice to have 2mm length of unbalanced wire carrying 5 amps to reach a force of 5*2e-3*1e-3 = 10µN of force ! I would be at the place of the experimenters I would go like "well, just subtract that component".
Title: Re: EM Drive Developments
Post by: frobnicat on 10/30/2014 09:48 pm
The actual response of Eagleworks does look something like this response to this  impulse + exponentially decaying rise forcing function:

Piecewise[{{(80*10^(-6))*(1-ssr)+(80*10^(-6))*ssr*(1-Exp[-t/tau])/(1-\
Exp[-30/tau]),t<30},{(80*10^(-6))*ssr*(Exp[-(t-30)/tau]),t>= \
30}}]

ssr=0.4

tau=4 seconds


Okay. This is not exactly what I expected at first, but it looks like there is a very significant part of the magnitude that is claimed as an "EM thrust" that is lagging quite a lot, and that part would be hardly compatible with any EM thrust interpretation (even the most crazy ones). That part needs to be explained (the fast one also !). That can't be the heating of the flexure bearings by the amplifier, this "drifting baseline" has a much longer time constant. Also this smoothing component is (visually) absent or much weaker (relative to pulse magnitude) from the calibrations pulses and from the "magnetic interaction" DC spurious @ 5.6 Amps (figure 20, with Null load) that are known to be rectangle excitations.

please send complaints to   [email protected]
Title: Re: EM Drive Developments
Post by: Rodal on 10/30/2014 10:48 pm
....

OK before I answer your posts about the degrees of freedom, etc.   

Let's deal with this picture:

What do you make of the first the 70 microNewtons impulsive rise followed by a very long exponentially decaying rise to  an extra 60 microNewtons ? The exponentially decaying rise is labeled (in red) RF ON

What's up with that?

They claim that the average thrust for this condition is 55 microNewtons.

What is the response in this case? two separate responses of 70 and 60 ? Why on top of each other? Why is one an impulse and the other one a long slow exponentially decaying rise?

Or is the response 70+60=130 microNewtons?

What's going on with that very well defined exponentially decaying rise to another 60 microNewtons?

And look at that very long exponentially decaying fall after that.  What's up with that?

How come the researchers failed to comment on this?  Well, what they wrote is that they had lots of trouble repeating this run (bold added for emphasis):

Quote from:  Brady, March, White, et.al.
Prior to the TM211 evaluations, COMSOL® analysis indicated that the TE012 was an effective thrust generation mode for the tapered cavity thruster being evaluated, so this mode was explored early in the evaluation process. Figure 22 shows a test run at the TE012 mode with an operating frequency of 1880.4 MHz. The measured quality factor was ~22,000, with a COMSOL prediction of 21,817. The measured power applied to the test article was measured to be 2.6 watts, and the (net) measured thrust was 55.4 micronewtons. With an input power of 2.6 watts, correcting for the quality factor, the predicted thrust is 50 micronewtons. However, since the TE012 mode had numerous other RF modes in very close proximity, it was impractical to repeatedly operate the system in this mode, so the decision was made to evaluate the TM211 modes instead.

Here we have probably the best well defined rectangular impulse calibration performed, and what is it followed by?

By an instantaneous impulse immediately followed by an exponentially decaying rise that is in proportion 6 to 7 or
0.46 to 1.
Title: Re: EM Drive Developments
Post by: aero on 10/30/2014 11:21 pm
Ok, here are my final estimates of Bradly cavity.

The method:
1. Extract pixel lengths of chords from the photograph on the left, scale lengths from Frazt beams, and including the visible length of the Frazt beam extended in back.
2. Extract pixel length of visible Frazt beam extended in back from photo on right, and verify it's scale. Calculate the added length value in right photo to the length in left photo.
3. Calculate distance from edge of base plate to Frazt beam in back using geometry from photo on right. It is 52.30234549 pixels.
4. Calculate the scale factor at the center of the base plate. It is 34.40258068 px/cm.
5. Calculate distance of camera from center of base plate in left hand photo using pinhole projection formula.
6. Calculate angular diameter of base plate viewed from camera.
7. Calculate angle between radius of base and base tangent line from camera.
8. Calculate radius of small and bases plate using above angles and projected chord length. It is factor times the chord length. w-s factor = 1.008039357, w-b factor = 1.025077351


Applying these correction factors gives:

w-b                w-s                  L
246.018292  138.7083271  221                 raw chords, pixels
252.187779  139.8234528  226.5420945   factored, pixels
27.92916748 15.48509864  25.0889719    Scaled to cm

Here, w-b factor was used to factor length as they are near in numerical value.
Title: Re: EM Drive Developments
Post by: aero on 10/30/2014 11:27 pm
Referring to this graphic.
Title: Re: EM Drive Developments
Post by: frobnicat on 10/30/2014 11:31 pm
.../...
And look at that very long exponentially decaying fall after that.  What's up with that?

How come the researchers failed to comment on this?

There are already quite a number of failed comments for a publication with claims of this nature (turning a century of physics on its head). Before I go to sleep : too bad we have only one single pulse to see with this "Brady c" data point. On one hand this is only one data point (but with a lot of points in it !) measured not far away to noise level. I'm not sure it's both fair and statistically relevant to dive in this one at this point. Maybe we could refine the tools ( Fb(t) reconstruction ) on the more voluminous "Brady a"  before tackling that one ?

On the other hand, well, the shape is relatively clean in its deviation from an expected rectangle response. I would be tempted to say that the descending slope after the RF ON is also an exp decay rather than just the background drift : note how it is roughly "aiming" back to the pre-pulse level (just before the second calibration pulse. Note also how the ringing amplitude, both on rise and fall, is much much lower than ringings of cal. pulses (of similar magnitude). My instinct would tell me that we have a similar "rectangle + exp_rise_decay" than from "Brady a" but with much longer time constants, to the point that the rectangle part is no longer instantaneous steps but also starts to show signs of limited rise/fall rates and lack the "hit" to ring the bell.

If this comparison holds then we should say this pulse yields more than 70+60(-spuriousDC) about 120 µN magnitude.

What is the main difference between Brady a and c ? Power and Q a lot, but the product of both not that much (a factor of 2, while the difference on the graphs seems more than that)

Possible induction that some effect(s) with time constant(s) depend on Power:
 Tau1=K1/Power  Tau2=K2/Power
Title: Re: EM Drive Developments
Post by: frobnicat on 10/30/2014 11:49 pm
Last word for tonight and I end this frobnicathon :

The magnetic damper is likely very well modelled as Fdamping = -k v  where v is velocity and k a damping constant.

For details this paper is full of details (case is for a damper with external circuit but can assume the circuit is closed at the eddy current levels)
https://dspace.mit.edu/bitstream/handle/1721.1/33174/65176850.pdf?sequence=1
page 43 equation 3.27 shows a linear response F = - k v  + a dot term for F, that is there is some time delay due to induction in the circuit.
page 44 below equation 3.30  we have a tau for this delay that is the ratio L/R of inductance on resistance. For eddy currents in a block of aluminium 10cm square 1cm thick I get very very roughly R=1e-5 Ohm and L=3e-8 henry that gives a tau of 3ms, way below the main natural period of beam : no phase shifting effect between oscillating velocity and damping force.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/31/2014 12:04 am
27.92916748 cm

Correct me if I'm wrong, but would the world come to an end if you called it 28 cm?

All those digits to the right of the decimal point are as arbitrary as the scaling factors I derived.

Not trying to be difficult or anything, but absent actual measurements, all of us are making judgement calls as to what we're measuring.  Nobody as yet has made a case regarding possible frequency  resonances with specific copper frustrum dimensions.  Or izzat what you all are doing and I, well, flat out do not get it?

If you all got complaints, our complaint manager is Helen Waite.  If you gotta complaint, go to Helen Waite.
Title: Re: EM Drive Developments
Post by: Rodal on 10/31/2014 01:03 am
Ok, here are my final estimates of Bradly cavity.

The method:
1. Extract pixel lengths of chords from the photograph on the left, scale lengths from Frazt beams, and including the visible length of the Frazt beam extended in back.
2. Extract pixel length of visible Frazt beam extended in back from photo on right, and verify it's scale. Calculate the added length value in right photo to the length in left photo.
3. Calculate distance from edge of base plate to Frazt beam in back using geometry from photo on right. It is 52.30234549 pixels.
4. Calculate the scale factor at the center of the base plate. It is 34.40258068 px/cm.
5. Calculate distance of camera from center of base plate in left hand photo using pinhole projection formula.
6. Calculate angular diameter of base plate viewed from camera.
7. Calculate angle between radius of base and base tangent line from camera.
8. Calculate radius of small and bases plate using above angles and projected chord length. It is factor times the chord length. w-s factor = 1.008039357, w-b factor = 1.025077351


Applying these correction factors gives:

w-b                w-s                  L
246.018292  138.7083271  221                 raw chords, pixels
252.187779  139.8234528  226.5420945   factored, pixels
27.92916748 15.48509864  25.0889719    Scaled to cm

Here, w-b factor was used to factor length as they are near in numerical value.


bigDaero = 27.92916748;
smallDaero = 15.48509864;
lengthaero = 25.0889719;

bigDJohn = 39.7;
smallDJohn = 24.4;
lengthJohn = 33.2;


Ratio of geometrical factor used in Shawyers and McCulloch1 formulas:

((1/smallDaero)-(1/bigDaero))/((1/smallJohn)-(1/bigDJohn)) = 1.82

(aero gives 82% higher results than Fornaro)



Ratio of geometrical factor used in McCulloch2 formula:

((lengthaero/smallDaero)-(lengthaero/bigDaero))/((lengthJohn/smallJohn)-(lengthJohn/bigDJohn)) = 1.38

(aero gives 38% higher results than Fornaro)


Title: Re: EM Drive Developments
Post by: aero on 10/31/2014 01:04 am
The spread sheet gave 27.92916748 15.48509864  25.0889719 but the world would continue to turn at 28 , 15.5, and 25. Of course the measurement depends on the corner points chosen. The sensitivity to a single pixel one way or the other is 0.113516284 cm/pixel or 1.135 mm/pixel and you can round just as easily as I can.

Arguments about who's the better round-offer might be misunderstood. Someone cowboy would take it as a round-up offer, quite a different thing.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/31/2014 01:28 am
Well, here's Aero's sketch and mine as well.

The one dimension we know for sure is the 1 1/2" FZTK stuff. We can arbitrarily assume that the focal plane of the camera is the verticle radius of the copper cone.  Looking at the image on the left, if the camera is 8 feet away then the "pinhole effect would indicate that the diameter of the cone would be some 26.abc-xyz cm in diameter.

If you don't know where the camera is or where the FZTK is, you don't know the correct angle to project.

There's not quite enough info in the images to get the cone diameter more accurately than around 28 cm, because every time you turn around, you have to make an arbitrary assumption.

I mean, that's how I C's it (https://www.youtube.com/watch?v=7DJSCTrNRdY)  On the dimensional aspect, people.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/31/2014 01:31 am
Arguments about who's the better round-offer might be misunderstood.

Aero:  Nobody's saying they're better at rounding off.  Take me, for zample.  I insist that there's too many unknowns to get a better estimate of those dimensions. 

Plus, if in my previous sketch, I divided wjhen I should have multiplied, lemme know.  don't be shy.
Title: Re: EM Drive Developments
Post by: aero on 10/31/2014 02:07 am
John: The camera is very close. Its distance can be calculated by measuring that 1 1/2" FZTK stuff in front and back then estimating/measuring the distance difference between them. And that distance can also be estimated/measured very closely from features in the two images. That distance difference and the pinhole projection formula is all that is needed, knowing the FZTK stuff is 1 1/2". It is a lot of work though and I'm not about to do it again. But it happens that the camera is only about 68 cm from the center axis of the big end base.

You can tell that the camera is close by looking at the diameter of the vacuum chamber which is 30 inches. In the 36 inches from the front to the back, the apparent diameter shrinks markedly. I didn't use that information because knowing the distance of the camera from the chamber door is not helpful.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/31/2014 11:23 am
John: The camera is very close. Its distance can be calculated by measuring that 1 1/2" FZTK stuff in front and back then estimating/measuring the distance difference between them.

Good point.  Lemme look at it again over the weekend, after I see my mixologist.
Title: Re: EM Drive Developments
Post by: francesco nicoli on 10/31/2014 11:49 am
Sorry for asking, but -as the discussion is getting very technical- could someone of you make a quick update for the non-physicists among us (like myself)? is there any tangible progress, or has the device been demistified once for all?

thanks! :)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 10/31/2014 12:29 pm
Sorry for asking, but -as the discussion is getting very technical- (1) could someone of you make a quick update for the non-physicists among us (like myself)? (2) is there any tangible progress, (3) or has the device been demistified once for all?

thanks! :)

1)  Second that emotion.
2)  No, per the experimentors.  Hopefully, per the math whizzes here.
3)  No.
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 10/31/2014 02:40 pm
If you all got complaints, our complaint manager is Helen Waite.  If you gotta complaint, go to Helen Waite.
As American-English culture is something that I learn painfully, I am happy to capture here yet another language joke nearly undecipherable for foreigners, thanks :-)
Title: Re: EM Drive Developments
Post by: Mulletron on 10/31/2014 03:36 pm
Shawyer made an explanation years ago about how the thruster would develop less and less thrust the faster it was going, but the mechanism made no sense, and it still proposed to violate conservation, and the whole notion of velocity changing thrust is again, a violation of relativity.  Velocity relative to what exactly?  Made no sense and that was just before they cut his funding in Great Britain, IIRC.

He was referring to doppler shifting which moves the center frequency outside the narrow resonant bandwidth of the cavity, lowering Q, lowering thrust.

I've seen 3 of his "compensated cavity" designs which address this in different ways. The first by means of changing the size of the cavity physically with gears/motors (like coarse tuning a radar), second by piezoelectrics, and more recently an accelerometer feedback to a signal generator.

http://www.emdrive.com/iac2014presentation.pdf page 5.

He discusses it here:
http://www.emdrive.com/IAC13paper17254.v2.pdf

Disclaimer: I'm not support Shawyer, just reporting what he is saying. I don't see doppler being an issue inside the cavity wrt the reference frame of the cavity.

Shawyer does operate as though the cavity and the magnetron feeding the cavity are different reference frames.

[rant]
From here:
http://emdrive.com/principle.html bottom of page
"However, this ignores Einstein’s Special Law of Relativity in which separate frames of reference have to be applied at velocities approaching the speed of light."~Where did Einstein say this?

Is his statement a twist on this?: The invariance of C in all reference frames.

It is as if he is confusing the fact that C is independent of any reference frame=true, with C is an inertial reference frame=false.

He also says that the electromagnetic waves and the waveguide assembly form an open system. This is dubious and puts a dubious twist on the fact that the laws of physics remain the same in any inertial reference frame, given the invariance of C in all reference frames. BTAIM, the cavity and waveguide are closed, so he cannot utilize this to derive linear thrust movement of the device. The Sagnac effect, from which RLGNs operate can't be used as justification for his theory, as the Sagnac effect deals with angular momentum. So using the Sagnac effect is a non-sequitur.
http://emdrive.com/principle.html
http://www.emdrive.com/theorypaper9-4.pdf
These are the root of all the problems concerning Shawyer's theory.The best he can do is make it spin, and indeed he does here:

http://www.youtube.com/watch?v=57q3_aRiUXs

The cavity and the amplifier feeding it and any vehicle it rides on, all share the same frame of reference.

Angular momentum of particles inside the cavity must be conserved:
http://www.youtube.com/watch?v=V3UsrfHa4MQ
[/rant]
Title: Re: EM Drive Developments
Post by: frobnicat on 10/31/2014 05:14 pm
I'm trying to scrap the data from the graphs of anomalous thrust... (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf) into a clean data format for the sheer enjoyment of all.

Problem with the vertical scale : page 15 fig. 19 we see that the calibration pulses of purported 30µN (29.1 precisely) span very close to 1 µm deviation on the vertical scale. Page 16 fig. upper left picture is more like 1.6 or 1.7 µm for the same purported 30µN, lower 2 pictures almost exactly 2 µm (always for 30µm or so). Page 17 fig.21 between 1.8 and 1.9 µN (to the naked eye). Page 18 fig. 22 no explicit vertical scale in µm.

How comes ? Am I to trust the cal. pulses amplitudes as an (approximate) way to scale µm to µN, therefore discarding the vertical left axis scale µm readings as irrelevant display feature (but those values otherwise look perfectly sensible as to the rest position) ? Is it possible that "variations" in stiffness of flexure bearings could change that much the µN/µm ratio ?? Could it be that the calibration pulses are, well, not that much calibrated ? Any indication in the reported that I missed that could explain this huge disparity ? What should be the torque/angle spring constant of the flexure bearings ? Or the calibration gizmo where moved along the beam's axis and that changed the torque at constant force ?

Title: Re: EM Drive Developments
Post by: Rodal on 10/31/2014 06:08 pm
To explain the impulse part of the response,

I need to have an independent estimate of the copper thickness in these devices.


could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?
Title: Re: EM Drive Developments
Post by: Mulletron on 10/31/2014 08:26 pm
To explain the impulse part of the response,

I need to have an independent estimate of the copper thickness in these devices.


could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?

I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.
Title: Re: EM Drive Developments
Post by: Rodal on 10/31/2014 08:35 pm
I'm trying to scrap the data from the graphs of anomalous thrust... (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf) into a clean data format for the sheer enjoyment of all.

Problem with the vertical scale : page 15 fig. 19 we see that the calibration pulses of purported 30µN (29.1 precisely) span very close to 1 µm deviation on the vertical scale. Page 16 fig. upper left picture is more like 1.6 or 1.7 µm for the same purported 30µN, lower 2 pictures almost exactly 2 µm (always for 30µm or so). Page 17 fig.21 between 1.8 and 1.9 µN (to the naked eye). Page 18 fig. 22 no explicit vertical scale in µm.

How comes ? Am I to trust the cal. pulses amplitudes as an (approximate) way to scale µm to µN, therefore discarding the vertical left axis scale µm readings as irrelevant display feature (but those values otherwise look perfectly sensible as to the rest position) ? Is it possible that "variations" in stiffness of flexure bearings could change that much the µN/µm ratio ?? Could it be that the calibration pulses are, well, not that much calibrated ? Any indication in the reported that I missed that could explain this huge disparity ? What should be the torque/angle spring constant of the flexure bearings ? Or the calibration gizmo where moved along the beam's axis and that changed the torque at constant force ?

This is more "stuff" done in a non-classical way.

Brito, Marini and Galian, with a smaller budget in deep South America, used a classical Cavendish-Coulomb setup and they measured the angle of rotation, which is the natural intrinsic variable that governs the torsional motion (more on this later concerning my analysis and why it is unclean and non-elegant to use displacements as degrees of freedom instead of rotations).  See attached setup to measure rotation by Brito, Marini and Galian in their tests where they successfully nullified the claims of the "Mach Lorentz Thruster".

NASA Eagleworks, on their hand measured displacements as follows (I bolden their attempts at force calibration):

Quote from: Brady, March, White, et.al
Displacement of the pendulum arm is measured via a Linear Displacement Sensor (LDS). The primary LDS components consist of a combined laser and optical sensor on the fixed structure and a mirror on the pendulum arm. The LDS laser emits a beam which is reflected by the mirror and subsequently detected by the optical sensor. The LDS software calculates the displacement (down to the sub-micrometer level) based upon the beam reflection time. Prior to a test run data take, the LDS is positioned to a known displacement datum (usually 500 micrometers) via mechanical adjustments to its mounting platform. Gross adjustments are performed via set screws. Fine adjustments are performed using manually-operated calibrated screw mechanisms and a remotely controlled motorized mechanism that can be operated with the chamber door closed and the chamber at vacuum. The remote adjustment capability is necessary since the LDS datum will change whenever a change to the test facility environment affects the roll-out table or the chamber – e.g., whenever the chamber door is closed or latched and whenever the chamber is evacuated. Once the LDS displacement is adjusted in the final test environment, further adjustment between test run data takes is usually not required.

Immediately prior to a test run data take, the displacement/force relationship is verified by inducing a known force onto the pendulum arm and measuring the displacement. This is done via the electrostatic fins calibration mechanism. This mechanism uses two sets of aluminum fins, one set on the fixed structure and one set on the pendulum arm. The fins overlap without touching. A calibration voltage is applied to the fixed structure fins, which induces a force upon the pendulum arm fins and an associated displacement that is measured by the LDS. The electrostatic fins design provides a constant force over a reasonably large range (between 30-70% overlap), so adjustments to the calibration mechanism between test run data takes and even between test article reconfiguration are usually not required. Calibration of the overlap/force relationship was accomplished using a Scientech SA 210 precision weighing balance (resolution to one micronewton).

Quote from: Paul March
In regards to force calibration we used a set of NIST traceable, pre-calibrated meshed electrostatic fins that provided a constant attractive force between the fin pair for a given applied calibration voltage over a 25% to 75% meshed fins range.  This feature allows us to generate the same calibration force independent of the loading of the torque pendulum's C-flex torsional bearings or how much the fin set is meshed within the noted fin mesh range.

So is their "calibration" changing in each test? (is that why they have to verify "the displacement/force relationship ") Why does it change? What makes it change?  In which direction are they measuring the displacement? Is this direction changing during the test or from test to test? Why?

In which direction is the force measured?  Precisely where (in relation to the center of rotation) is the force measured? and many other questions...
Title: Re: EM Drive Developments
Post by: aero on 10/31/2014 08:42 pm
To explain the impulse part of the response,

I need to have an independent estimate of the copper thickness in these devices.


could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?

I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.

I expect the cavities were made of some commonly available copper sheet. I doubt that Eagleworks did anything more difficult than go to the hardware store and buy a sheet of copper. Here is a web site that sells copper sheet. Look at the choices and take your pick. Or find your own favorite copper sheet retailer. Or call your local hardware store and ask them what thicknesses they have in stock. But from looking at the photo I can't tell, the resolution isn't good enough.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/31/2014 09:14 pm
Well my previous post about Shawyer
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1280373#msg1280373
provided a lot of critical analysis, and possibly some insight, but not many solutions. One of my pet peeves are people who point out problems but don't provide solutions; so here's my solution.

We must find a means in which a thrust vector can be attained which doesn't violate local and global conservation laws. This essentially means that we must thrust against a medium which will provide an equal and opposite reaction, but still exists inside and outside of the copper cavity. This medium must obviously be weekly interacting under normal experience, but will be available for work, when properly engineered (or fumbled upon). At least explained..... The QV, fits the bill. The QV is such a vague term. But one must remember that the QV is simply the ground state of all known fields and interactions. Now one must first ask themselves, what are all the known fields and interactions? Now of those known fields and interactions, which one(s) of those vacuum fields can provide an inertial frame of reference in which Newton's first law of motion applies? I can immediately drop fields composed of massless particles, so no photons or gluons. Massless particles, like photons are invariant. One can argue that the speed of light is slower or faster than C in a medium vs a vacuum and be correct, but they are confusing terms, as the phase and group velocity of light may vary in a medium, but the fundamental speed of light remains the same. The apparent slowing of the front velocity of light is only caused by the absorption and emission of photons by the atoms of the medium. I really feel that a dielectric medium is the means to provide a thrust vector to the vacuum. I believe that vacuum fields composed of particles with rest mass (invariant mass) are the ticket. So we have the electron field to play with right off the top of my head. Electrons have a rest mass of .511 Mev.
Title: Re: EM Drive Developments
Post by: Mulletron on 10/31/2014 09:15 pm
To explain the impulse part of the response,

I need to have an independent estimate of the copper thickness in these devices.


could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?

I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.

I expect the cavities were made of some commonly available copper sheet. I doubt that Eagleworks did anything more difficult than go to the hardware store and buy a sheet of copper. Here is a web site that sells copper sheet. Look at the choices and take your pick. Or find your own favorite copper sheet retailer. Or call your local hardware store and ask them what thicknesses they have in stock. But from looking at the photo I can't tell, the resolution isn't good enough.

Yes sir! My leads were from commonly available stock too. And smart fellers on this forum.
Title: Re: EM Drive Developments
Post by: Rodal on 10/31/2014 09:24 pm
To explain the impulse part of the response,

I need to have an independent estimate of the copper thickness in these devices.


could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?

I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.

I expect the cavities were made of some commonly available copper sheet. I doubt that Eagleworks did anything more difficult than go to the hardware store and buy a sheet of copper. Here is a web site that sells copper sheet. Look at the choices and take your pick. Or find your own favorite copper sheet retailer. Or call your local hardware store and ask them what thicknesses they have in stock. But from looking at the photo I can't tell, the resolution isn't good enough.

aero, although you wrote "Here is a web site that sells copper sheet" I do not see any web site information in your message.   Could you please indicate what website you have in mind?

Mlltrn suggested copper 1/8" thick, that is thicker than the copper sheet readily available at my local hardware store.  Do you think that they likely used thinner copper than 1/8?  (I think that 1/16" would have been easier to work with.  All these sheets are already smooth and shiny)
Title: Re: EM Drive Developments
Post by: Rodal on 10/31/2014 09:30 pm
Sorry for asking, but -as the discussion is getting very technical- could someone of you make a quick update for the non-physicists among us (like myself)? is there any tangible progress, or has the device been demistified once for all?

thanks! :)

Francesco, we are getting close to showing, analytically, that the EM Drives test results are likely an experimental artifact.
Title: Re: EM Drive Developments
Post by: aero on 10/31/2014 11:01 pm
To explain the impulse part of the response,

I need to have an independent estimate of the copper thickness in these devices.


could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?

I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.

I expect the cavities were made of some commonly available copper sheet. I doubt that Eagleworks did anything more difficult than go to the hardware store and buy a sheet of copper. Here is a web site that sells copper sheet. Look at the choices and take your pick. Or find your own favorite copper sheet retailer. Or call your local hardware store and ask them what thicknesses they have in stock. But from looking at the photo I can't tell, the resolution isn't good enough.

aero, although you wrote "Here is a web site that sells copper sheet" I do not see any web site information in your message.   Could you please indicate what website you have in mind?

Mlltrn suggested copper 1/8" thick, that is thicker than the copper sheet readily available at my local hardware store.  Do you think that they likely used thinner copper than 1/8?  (I think that 1/16" would have been easier to work with.  All these sheets are already smooth and shiny)

 :-[ Well, I lost the site I was looking at earlier. Here's one that includes a thickness guide for choosing copper for a project. That might help but you'll have to convert the thickness to metric.

http://basiccopper.com/copper-sheet--rolls.html (http://basiccopper.com/copper-sheet--rolls.html)
Title: Re: EM Drive Developments
Post by: Rodal on 10/31/2014 11:15 pm
....
 :-[ Well, I lost the site I was looking at earlier. Here's one that includes a thickness guide for choosing copper for a project. That might help but you'll have to convert the thickness to metric.

http://basiccopper.com/copper-sheet--rolls.html (http://basiccopper.com/copper-sheet--rolls.html)

They show at the site you included thicknesses that range between 0.001 to 0.022 inches, while Mlltrn suggested 0.125 inches (125 times to 6 times thicker).  In other words, you think that NASA used much thinner copper than him
Title: Re: EM Drive Developments
Post by: frobnicat on 10/31/2014 11:55 pm
First attempt to scrap the data and infer some parameter of the balance. From the top picture of figure 19 only, median natural period of oscillation would be 4.8s. A proper spectrum analysis would be more elegant but since I don't have those tools at hand I went through crest detection. See attached picture. Crests where filtered as per there relative magnitude, kept if minimum amplitude between two subsequent crests were above 5µN, working on a curve passed through a (lousy first order) band pass filter roughly centred on the target freq to measure (bottom curve) and manually discarding the periods across a known step excitation (since those would fall at random phase relative to ongoing previous remaining oscillations).

There is a lot of variance, also I don't know if all those crests are relevant, the Brady et al paper say there is coupling with oceanic waves or such at a third or fourth a Hertz, that might explain the shorter periods somehow and the permanent background of excitation I was wondering about, this is in the same 3s to 4s period ballpark as the low Q main resonance mode of the balance. Something is happening after the second calibration pulse (a significant dip), someone slamming a door in the lab or a loose cable hanging around ? Anyhow, with this high dispersion I think it's better to take the median and the median is 4.8 s period.

Also attached is a zip with a file (unix line endings, don't open with notepad windows, notepad++ or such instead) list of data points at .1s intervals. This is giving directly µN readings, based on the amplitude of calibration pulses at 30µN for the vertical scale. Since the baseline is drifting the absolute level is irrelevant, but it should be ok to study dynamics of the signal. This was obtained after painfully following the curve manually with a broken line (piecewise linear, latest attachment to see typical detail). The added yellow paintings and compression artifacts made it impossible to automate the process. The .1 s data points are locally averaged (running average .1s left and right at each point) from this linear piecewise reconstruction of best possible visual interpretation of pixels. Expect a lot of artifacts (quantisation from data acquisition, from data display, from camera, from compression, from piecewise linear reconstruction, from pseudo smoothing a bit around .2s ...) but those artifacts would be found for frequencies higher than 2 or 3 Hz. I didn't want to try to smooth that with too much lowpass filtering, not to erode the steps responses.

Oh yes, also the perspective is put back flat (middle graph) with bilinear interpolation from the original (top graph). There would be still a small vertical magnitude factor not corrected (more amplitude on top of graph than on bottom) but should be pretty small. The slopes are much better.

Will proceed with other curves, and try to pin down the damping factor (assuming simple underdamped harmonic oscillator).
Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 12:12 am
...A proper spectrum analysis would be more elegant but since I don't have those tools at hand I went through crest detection. ...

I have the tools at hand to do a spectrum analysis but we don't have the data in digital form to use as an input.  I guess that I could do an image analysis by computer to extract the digital data, but at the moment I rather use this time to analytically explain the impulse part of the data.
Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 12:14 am
First attempt to scrap the data and infer some parameter of the balance. From the top picture of figure 19 only, median natural period of oscillation would be 4.8s. ...

Paul March (page 30 of this thread) had written:

Quote from: Paul March
The natural oscillation period of the pendulum arm when loaded with the RF amplifier, its RF plumbing and the test article was around 4.5 seconds.
Title: Re: EM Drive Developments
Post by: Supergravity on 11/01/2014 12:23 am
Sorry for asking, but -as the discussion is getting very technical- could someone of you make a quick update for the non-physicists among us (like myself)? is there any tangible progress, or has the device been demistified once for all?

thanks! :)

Hi there.

I wouldn't put much stock in the ostensibly technical speculations that fill this thread. The results are certainly wrong and are in clear violations of macroscopic conservation of momentum. All explanations or "models" proposed to explain this (quantum plasma, virtual particles, etc.) are all based on incredibly bad physics.

Any signal these experimenters find is almost certainly due to a terrible experimental method and questionable data analysis.

As far as I can tell, along with the greater physics and engineering communities (from what I have seen), this is a fantasy device.
Title: Re: EM Drive Developments
Post by: aero on 11/01/2014 12:30 am
....
 :-[ Well, I lost the site I was looking at earlier. Here's one that includes a thickness guide for choosing copper for a project. That might help but you'll have to convert the thickness to metric.

http://basiccopper.com/copper-sheet--rolls.html (http://basiccopper.com/copper-sheet--rolls.html)

They show at the site you included thicknesses that range between 0.001 to 0.022 inches, while Mlltrn suggested 0.125 inches (125 times to 6 times thicker).  In other words, you think that NASA used much thinner copper than him

Sorry, I looked some more. The site I lost sold 1/8 copper sheet. But copper sheet is available from film to 1 inch plate so looking for a common thickness of sheet isn't going to help us. I would guess it is 1/8-th inch sheet but I've nothing to base that on except having seen it around here and there and it looks like 1/8-th inch.

Of course it could be 1/16-th inch sheet and I wouldn't know the difference. For the application it needs to be thin enough to roll into a cone and crimp right angle bends at both ends to attach the end plates. Then it also needs to be thick enough to hold its shape or pop back into shape when/if it is dented. Will 1/16 inch verses 1/8 inch make a difference in your calculations?

Looking at my ruler, I'd go with the thinner sheet. One-eighth inch is 0.3175 cm and we might be able to see that on the photos.

Add: In fact, the photo resolution is 0.11 cm/pixel, so 1/8 inch would be about 3 pixels which we would certainly be able to see. Is there a rule about resolution of a photo? We might even see 1/16 inch, at 1.5 pixels.
Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 12:56 am
....
 :-[ Well, I lost the site I was looking at earlier. Here's one that includes a thickness guide for choosing copper for a project. That might help but you'll have to convert the thickness to metric.

http://basiccopper.com/copper-sheet--rolls.html (http://basiccopper.com/copper-sheet--rolls.html)

They show at the site you included thicknesses that range between 0.001 to 0.022 inches, while Mlltrn suggested 0.125 inches (125 times to 6 times thicker).  In other words, you think that NASA used much thinner copper than him

Sorry, I looked some more. The site I lost sold 1/8 copper sheet. But copper sheet is available from film to 1 inch plate so looking for a common thickness of sheet isn't going to help us. I would guess it is 1/8-th inch sheet but I've nothing to base that on except having seen it around here and there and it looks like 1/8-th inch.

Of course it could be 1/16-th inch sheet and I wouldn't know the difference. For the application it needs to be thin enough to roll into a cone and crimp right angle bends at both ends to attach the end plates. Then it also needs to be thick enough to hold its shape or pop back into shape when/if it is dented. Will 1/16 inch verses 1/8 inch make a difference in your calculations?

Looking at my ruler, I'd go with the thinner sheet. One-eighth inch is 0.3175 cm and we might be able to see that on the photos.

Add: In fact, the photo resolution is 0.11 cm/pixel, so 1/8 inch would be about 3 pixels which we would certainly be able to see. Is there a rule about resolution of a photo? We might even see 1/16 inch, at 1.5 pixels.

And remember that D goes like the cube of the thickness, so that 1/8" has a D 8 times greater than 1/16"
Title: Re: EM Drive Developments
Post by: aero on 11/01/2014 02:05 am
I expanded the photo as big as it will go, and slowed my mouse as slow as it will go to take out my hand shake, and picked off a 5 pixel width of the big end edge. At that scale the 3.81 cm Frzl? beam end was 110 pixels but close to the same distance from the camera.

Five pixels at that scale comes out to be 0.173 cm, or 1/16". But there is the question as to just what I measured because the ends of the cavity seem to be a board of some sort, and not all copper.

What are you trying to do? I guess you want to see if the vibration comes from flexing of the thin copper. But at a GHz, that seems unlikely. Better to analyze than guess, though. But if the end is a copper covered board, as has been suggested, what would be the density of that? And what would be the likelihood of the copper covering vibrating independently of the board? Coming loose, so to speak.
Title: Re: EM Drive Developments
Post by: zen-in on 11/01/2014 02:23 am
To explain the impulse part of the response,

I need to have an independent estimate of the copper thickness in these devices.


could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?

I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.

I expect the cavities were made of some commonly available copper sheet. I doubt that Eagleworks did anything more difficult than go to the hardware store and buy a sheet of copper. Here is a web site that sells copper sheet. Look at the choices and take your pick. Or find your own favorite copper sheet retailer. Or call your local hardware store and ask them what thicknesses they have in stock. But from looking at the photo I can't tell, the resolution isn't good enough.


The cone looks like it was made from 20 gauge or thinner copper, possibly the same material roofers use.  You sometimes see trucks with a big spool of it on the back.   1/8" Thick copper would require machine tools like a metal press to form.  Even 1/16" thick copper (14 gauge is the closest) requires a lot of work to form into a cone and the tool marks would show.   Also the weight would be an issue.  I think it is most likely 20 to 26 gauge (.032" - .016").   Building an apparatus like the eagleworks em-drive would not be difficult.   Just a few large pieces of FR4, some lightweight Copper sheets and a jig for forming it into the cone shape.   
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/01/2014 02:52 am
Sorry for asking, but -as the discussion is getting very technical- could someone of you make a quick update for the non-physicists among us (like myself)? is there any tangible progress, or has the device been demistified once for all?

thanks! :)

Francesco, we are getting close to showing, analytically, that the EM Drives test results are likely an experimental artifact.

Sorry for asking, but -as the discussion is getting very technical- could someone of you make a quick update for the non-physicists among us (like myself)? is there any tangible progress, or has the device been demistified once for all?

thanks! :)

Hi there.

I wouldn't put much stock in the ostensibly technical speculations that fill this thread. The results are certainly wrong and are in clear violations of macroscopic conservation of momentum. All explanations or "models" proposed to explain this (quantum plasma, virtual particles, etc.) are all based on incredibly bad physics.

Any signal these experimenters find is almost certainly due to a terrible experimental method and questionable data analysis.

As far as I can tell, along with the greater physics and engineering communities (from what I have seen), this is a fantasy device.

SuperG:  You either need to brush up on reading comprehension, or yuo need to brush up on saying exactly what you mean.

Francesco asked a reasonable question, and  Jose answered it, saying, "the EM Drives test results are likely an experimental artifact".  You go on to say that these results are "certainly wrong".  In other words, since Jose must be "certainly wrong", the results are not an experimental artifact and must therefore be real.  Then you go on to contradict yourself and assert that it is a "fantasy device".

Again, just decide what you want to say.  And then say it.  You cannot claim both sides of the discussion as your truth.

Title: Re: EM Drive Developments
Post by: ThinkerX on 11/01/2014 03:34 am
Quote
Sorry for asking, but -as the discussion is getting very technical- could someone of you make a quick update for the non-physicists among us (like myself)? is there any tangible progress, or has the device been demistified once for all?

Fascinated member of the peanut gallery here.  I can take a shot at the highlights covered over the past 100 or so pages in this thread, though it may not be entirely accurate.

When Doctor Rodal first posted in this thread, he was of the view the reported results were an experimental artifact, most likely thermal in nature.  After a post by a member of the Eagleworks team casting doubt on this assumption, he and the other regular posters here began looking for alternatives, especially experimental artifacts.  Contrary to what 'Supergravity' posted, the explanations for the devices performances were seen by the brainier types here to be flawed from the outset.

A number of reasonably rational scientific explanations were considered should all the experimental artifacts be ruled out.  Of these, few showed any promise:

1) The device was somehow pushing against 'Dark Matter.'  This might be valid, if one accepts a very high estimate for the local abundance of Dark Matter.  But still dubious. 

2) Ion Wind devices, using the Bifield - Brown effect.  This is a real effect, used by...hobbyist...to make pure electrical flying devices.  Search for 'Anti-Gravity' in You-Tube sometime to see videos of these devices in action.  Ultimately, this was ruled out because of the very low power levels involved.

3) Unruh Radiation, which is a sort of 'inertia radiation', which is an element in a branch of physics attempting to make General Relativity and Quantum Mechanics play well together.  It also negates many of the more dubious elements theorists have conjured to explain observed astronomical reality - things like dark matter and dark energy.  A professor McCulloch has been promoting this on his blog, which is occasionally linked to in this thread.  So...   

http://physicsfromtheedge.blogspot.com/

Many of the last few dozen pages have been dedicated to gathering enough info about the various EM devices tested to run 'back of the envelope' calculations as to whether or not Unruh Radiation is a viable solution.  Results have been mixed, in no small part because even basic information about these devices - like their size and proportions - is very difficult to come by.  Additionally, this explanation is very frequency dependent, and worse, the frequency shifts.  The experimenters are essentially blundering about in the dark, hitting the correct frequency by occasional accident.   Unruh Radiation is still considered a possibility, and I believe several members here find the theory of great interest even if they doubt the EM Drive is somehow tapping into it.  Which brings us to where matters stand now:

The experimenters are demonstrating an across the board failure to understand certain 'stress forces' which have a high possibility of giving at least partial false results in their experiments.  Furthermore, the explanatory equations put forth by both Doctor White and Shawyer have errors within them.  Which means the results may be false positives - the EM Drive does not work.

That said, the notion of tapping into Unruh Radiation and using it to propel a starship is interesting in its own right.

And even if Unruh Radiation does not exist, some force, currently termed 'Dark Energy' exerts enough force on space-time to drive galaxies apart at a continuous 1 kilometer per second per kilo parsec. 

(I hope I didn't get too many things wrong here.)



Title: Re: EM Drive Developments
Post by: Mulletron on 11/01/2014 07:38 am
Did I mention that every time someone mentions Unruh Radiation and Emdrive in the same sentence, a cute bunny gets it? Seriously though, a kid reading this forum is going to have his/her ideas about science all jacked up because of the enduring false info that keeps being perpetuated around here because it is popular, or some PhD sponsors it. I know back when I was a little feller, I ate this space and physics stuff up as fast as I could get my hands on it. I'm lucky internet forums weren't around back then.

A photon doesn't experience Unruh Radiation. Accelerate a massive object toward C and it might experience Unruh Radiation (if it exists). A photon is simply a disturbance in the electromagnetic field that propagates at C. The photon is the force carrier of that disturbance. It doesn't accelerate to get to C. It is always at C.

Is anything I'm posting here being taken seriously? I'm not making this stuff up. I get the sense that the truths I speak here are being blackballed in favor of fantasy or popular opinion which aren't even close to science. Um, science isn't democratic and opinion doesn't matter. Just the facts matter.

We were probably on the right track with modified inertia, but a monster got created out of it. Light doesn't even have inertia. You can't modify the inertia of light. Light has momentum, but not inertia. You can modify the inertia of all the other stuff which has mass inside that copper can, but not the RF. Leave light alone and start applying MiHsC in the right direction, to the particles in the copper can which actually have inertia. It is being applied bass ackwards right now. Then lets hope that copper cans can actually modify inertia a little bit in the first place. We're already on thin ice trying to mess with inertia.

The whole reason modified inertia came into being in this forum is directly from the factual knowledge that the symmetry of space directly informs our conservation laws, and that the asymmetry of the copper cavity may very very slightly modify that symmetry of space, thus possibly allowing an inertial bias of the matter (dielectric/air) within the cavity. Not the rf. Don't believe me? Look back in time in this thread and see when I starting going on about inertia.

Later it was discovered that the asymmetry of the cavity wasn't even needed/nor was modified inertia, because of new information found regarding the behavior of chiral dielectrics.

So that whole MiHsC can of worms, which required messing with EEP right here on Earth, wasn't needed anymore. That is a good thing for the sake of the theory. MiHsC could be returned to the realm of low accelerations at galactic scales where it belonged. MiHsC is no less important. It simply isn't useful here on Earth. I'd hate to see the rest of the scientific world poo poo a perfectly good theory because it was applied too broadly and lost credibility. Especially if it is applied incorrectly to light.

Well anyway I'm not here to be popular. I'm here to look at the facts and use all available information to figure things out. All while not tricking myself or pushing I believe buttons.

If the above doesn't apply to you, please disregard.

If I got my science wrong, please correct me. I've gotten things wrong before and have no problem changing my views given new/better information.

Respectfully,
Mulletron
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/01/2014 01:08 pm
Just a quick update on looking at GR:  Can't find an inertial hook.  The cavity would have to modify the frequency to give an AFR.  Don't see any mechanism yet......still looking.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/01/2014 01:27 pm
Fascinated member of the peanut gallery here. Peanut crop was good this year, eh?

I can take a shot at the highlights covered over the past 100 or so pages in this thread ....

... Rodal ... was of the view the reported results were an experimental artifact, most likely thermal in nature.  After a post ... he and the other regular posters here began looking for alternatives, especially experimental artifacts.  ... the explanations for the device's performances were seen ... to be flawed from the outset.

A number of reasonably rational scientific explanations were considered should all the experimental artifacts be ruled out.  Of these, few showed any promise:

1) The device was somehow pushing against hypothetical (http://en.wikipedia.org/wiki/Dark_matter)
 'Dark Matter.' This might be valid, if one accepts a very high estimate for the local abundance of Dark Matter,  which stell needs to be found.  But still dubious. 

2) Ion Wind devices, using the Bifield - Brown effect.  This is a real effect, used by...hobbyist...to make pure electrical flying devices.  ... this was ruled out because of the very low power levels involved and because it needs atmosphere of a higher density than space to create ions out of.

3) Unruh Radiation, which is a sort of 'inertia radiation', which is an element in a branch of physics attempting to make General Relativity and Quantum Mechanics play well together, and which is also sort of hypothetical (http://en.wikipedia.org/wiki/Unruh_effect).  [Unruh radiation] also negates many of the more dubious elements theorists have conjured to explain observed astronomical reality - things like dark matter and dark energy.  A professor McCulloch has been promoting this on his blog, which is occasionally linked to in this thread.  So...   

http://physicsfromtheedge.blogspot.com/

Many of the last few dozen pages have been dedicated to gathering enough info about the various EM devices tested to run 'back of the envelope' calculations as to whether or not Unruh Radiation is a viable solution.  Results have been mixed, in no small part because even basic information about these devices - like their size and proportions - is color=blue]unnecessarily[/color] very difficult to come by thru no fault of the thread's theorists.  Additionally, this explanation is very frequency dependent, and worse, the frequency shifts.  The experimenters are essentially blundering about in the dark, hitting the correct frequency by occasional accident.   Unruh Radiation is still considered a possibility, and I believe several members here find the theory of great interest even if they doubt the EM Drive is somehow tapping into it.  Which brings us to where matters stand now:

The experimenters are demonstrating an across the board failure to understand certain 'stress forces' which have a high possibility of giving at least partial false results in their experiments.  The "across the board failure" is particularly troublesome, since there is no good reason for that failure.  Furthermore, the explanatory equations put forth by both Doctor White and Shawyer have errors within them.  Which means the results may be false positives - the EM Drive does not work.

That said, the notion of tapping into Unruh Radiation and using it to propel a starship is interesting in its own right.

And even if Unruh Radiation does not exist, some force, currently termed 'Dark Energy' exerts enough force on space-time to drive galaxies apart at a continuous 1 kilometer per second per kilo parsec. 

(I hope I didn't get too many things wrong here.)

I just added a few blue remarks as I talked to the screen.
Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 01:32 pm
I expanded the photo as big as it will go, and slowed my mouse as slow as it will go to take out my hand shake, and picked off a 5 pixel width of the big end edge. At that scale the 3.81 cm Frzl? beam end was 110 pixels but close to the same distance from the camera.

Five pixels at that scale comes out to be 0.173 cm, or 1/16". But there is the question as to just what I measured because the ends of the cavity seem to be a board of some sort, and not all copper.

What are you trying to do? I guess you want to see if the vibration comes from flexing of the thin copper. But at a GHz, that seems unlikely. Better to analyze than guess, though. But if the end is a copper covered board, as has been suggested, what would be the density of that? And what would be the likelihood of the copper covering vibrating independently of the board? Coming loose, so to speak.

Thank you, aero, for this very comprehensive view at the copper thickness, with the conclusion that the copper seems to be thinner than 1/16".

I am looking at thermoelastic coupling to explain the initial impulse part of the response.  Thermoelastic coupling is usually neglected in the equations of thermoelasticity.

Taking:

thermal diffusivity = 1.11 * 10^(-4) m/s
poisson's ratio = 0.3
E = 117 GPa
density = 8940 kg/m^3
Length = 0.25 m (latest length estimate for truncated cone length from aero)

I get that the thickness of copper would have to be less than 0.073 inches for coupling effects to be important so that inertial terms due to temperature would appear.  For copper thickness = 0.029 in or less, the inertial terms are such that the dynamic magnification factor are quite significant.  For that thinness of copper one gets (due to classical physics) what essentially are thermal waves in the initial part of the response.

So the initial impulse would be a result of inertia due to thermoelastic coupling, and the later decaying exponential rise would be explained as per frobnicat.  Both effects are entirely classical.
Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 01:37 pm
To explain the impulse part of the response,

I need to have an independent estimate of the copper thickness in these devices.


could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?

I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.

I expect the cavities were made of some commonly available copper sheet. I doubt that Eagleworks did anything more difficult than go to the hardware store and buy a sheet of copper. Here is a web site that sells copper sheet. Look at the choices and take your pick. Or find your own favorite copper sheet retailer. Or call your local hardware store and ask them what thicknesses they have in stock. But from looking at the photo I can't tell, the resolution isn't good enough.


The cone looks like it was made from 20 gauge or thinner copper, possibly the same material roofers use.  You sometimes see trucks with a big spool of it on the back.   1/8" Thick copper would require machine tools like a metal press to form.  Even 1/16" thick copper (14 gauge is the closest) requires a lot of work to form into a cone and the tool marks would show.   Also the weight would be an issue.  I think it is most likely 20 to 26 gauge (.032" - .016").   Building an apparatus like the eagleworks em-drive would not be difficult.   Just a few large pieces of FR4, some lightweight Copper sheets and a jig for forming it into the cone shape.   

Thank you zen-in for this very practical view at the fact that the copper thickness seems to be much thinner than the 1/8 in suggested by Mlltrn.  That suits my calculations just fine.

I am looking at thermoelastic coupling to explain the initial impulse part of the response.  Thermoelastic coupling is usually neglected in the equations of thermoelasticity.

Taking:

thermal diffusivity = 1.11 * 10^(-4) m/s
poisson's ratio = 0.3
E = 117 GPa
density = 8940 kg/m^3
Length = 0.25 m (latest length estimate for truncated cone length from aero)

I get that the thickness of copper would have to be less than 0.073 inches for coupling effects to be important so that inertial terms due to temperature would appear.  For copper thickness = 0.029 in or less, the inertial terms are such that the dynamic magnification factor are quite significant.  For that thinness of copper one gets (due to classical physics) what essentially are thermal waves in the initial part of the response.
Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 01:57 pm
The coupling coefficient (basically due to the strain rate being larger than the temperature rate) is non-trivial.  But calculating the Fourier non-dimensional time is trivial, so let's calculate the time for which the Fourier non-dimensional = 1, which is simply ((thickness)^2)/thermalDiffusivity


thermalDiffusivity = 1.11*10^(-4) m/s

so for thickness of copper = 1/8 in = 0.00318 m
hence time = 0.0908 s

so for thickness of copper = 1/16 in = 0.00159 m
hence time = 0.0227 s

so for thickness of copper = 0.022 in = 0.000559 m
hence time = 0.0028 s

So, the initial thermal effect on the copper thickness is clearly impulsive, from the point of view of the much slower response of the inverted torsional pendulum (with period ~ 4.5 s as provided by Paul March himself, or 4.8 s as measured by frobnicat, and both of them corroborated by my analytical model of the inverted torsional pendulum)
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/01/2014 02:01 pm
The coupling coefficient is non-trivial.  But calculating the Fourier non-dimensional time is trivial, so let's calculate the time for which the Fourier non-dimensional = 1, which is simply ((thickness)^2)/thermalDiffusivity


thermalDiffusivity = 1.11*10^(-4) m/s

so for thickness of copper = 1/8 in = 0.00318 m
hence time = 0.0908 s

so for thickness of copper = 1/16 in = 0.00159 m
hence time = 0.0227 s

so for thickness of copper = 0.022 in = 0.000559 m
hence time = 0.0028 s

So, the initial thermal effect on the copper thickness is clearly impulsive, from the point of view of the much slower response of the inverted torsional pendulum (with period ~ 4.5 s)

Great!  Look at the drumhead expansion of the big end .002" copper FRP w/ resistve heating from the Cu loss!

http://en.wikipedia.org/wiki/FR-4
Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 03:08 pm
The coupling coefficient is non-trivial.  But calculating the Fourier non-dimensional time is trivial, so let's calculate the time for which the Fourier non-dimensional = 1, which is simply ((thickness)^2)/thermalDiffusivity


thermalDiffusivity = 1.11*10^(-4) m/s

so for thickness of copper = 1/8 in = 0.00318 m
hence time = 0.0908 s

so for thickness of copper = 1/16 in = 0.00159 m
hence time = 0.0227 s

so for thickness of copper = 0.022 in = 0.000559 m
hence time = 0.0028 s

So, the initial thermal effect on the copper thickness is clearly impulsive, from the point of view of the much slower response of the inverted torsional pendulum (with period ~ 4.5 s)

Great!  Look at the drumhead expansion of the big end .002" copper FRP w/ resistve heating from the Cu loss!

http://en.wikipedia.org/wiki/FR-4

I need to know the boundary conditions for the 0.002" copper.

Is the 0.002" copper a separate thin sheet of copper, or is the 0.002" copper thermally sprayed on the fiber-reinforced-polymer substrate and hence integrally bonded to it, or is the 0.002" copper adhered to the fiber-reinforced-polymer substrate ?

Can the 0.002" be easily peeled apart from the polymer composite substrate?
(Can one hold on to that 0.002" copper with pliers and peel it apart from the polymer composite substrate?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/01/2014 03:12 pm
Yes, it's adhesive bonded.
Title: Re: EM Drive Developments
Post by: aero on 11/01/2014 04:41 pm
Does the label on the end of the cavity material mean anything to anyone?

As I read it, it is "1605Mg" but even blown up as large as it will go, it is hard to tell for sure.
Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 08:43 pm
The coupling coefficient (basically due to the strain rate being larger than the temperature rate) is non-trivial.  But calculating the Fourier non-dimensional time is trivial, so let's calculate the time for which the Fourier non-dimensional = 1, which is simply ((thickness)^2)/thermalDiffusivity


thermalDiffusivity = 1.11*10^(-4) m/s

so for thickness of copper = 1/8 in = 0.00318 m
hence time = 0.0908 s

so for thickness of copper = 1/16 in = 0.00159 m
hence time = 0.0227 s

so for thickness of copper = 0.022 in = 0.000559 m
hence time = 0.0028 s

So, the initial thermal effect on the copper thickness is clearly impulsive, from the point of view of the much slower response of the inverted torsional pendulum (with period ~ 4.5 s as provided by Paul March himself, or 4.8 s as measured by frobnicat, and both of them corroborated by my analytical model of the inverted torsional pendulum)
Another trivial thing we can do is to compute the mechanical characteristic times for wave propagation (as compared to thermal characteristic times given by Fourier's number), to confirm that they are much smaller than the thermal time.  In fact they are about 1000 times smaller.

Velocity of propagation of Lamb bending waves in a thin plate = vL = Sqrt [E/(rho*(1-nu^2)) ]

(for wavelengths larger than the thickness of the plate, otherwise for wavelengths smaller than the thickness of the plate the velocity of propagation is that of Raleigh surface waves)

where

E= modulus = 117 GPa =117 *10^9  kg/(m s^2)
rho = density = 8940 kg/m^3
nu = Poisson's ratio =  0.3

vL = 3792 m/s

Length = 0.25 m (latest estimate for the truncated cone's length from aero)

time = 0.25 m / 3792 m/s = 65.9 microseconds

Length = 0.28 m (latest estimate for the truncated cone's Big Diameter from aero)

timeL = 0.28 m / 3792 m/s = 73.8 microseconds

Length = 0.15 m (latest estimate for the truncated cone's Small Diameter from aero)

time = 0.15 m / 3792 m/s = 39.6 microseconds




Velocity of propagation of Raleigh surface (nu=0.3) = vR = 0.93 [E/(rho*2*(1+0.3)) ]

vR = 2087 m/s

Length = 0.25 m (latest estimate for the truncated cone's length from aero)

time = 0.25 m / 2087 m/s = 120 microseconds

Length = 0.28 m (latest estimate for the truncated cone's Big Diameter from aero)

timeL = 0.28 m / 2087 m/s = 134 microseconds

Length = 0.15 m (latest estimate for the truncated cone's Small Diameter from aero)

time = 0.15 m / 2087 m/s = 71.9 microseconds

Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 09:22 pm
The coupling coefficient is non-trivial.  But calculating the Fourier non-dimensional time is trivial, so let's calculate the time for which the Fourier non-dimensional = 1, which is simply ((thickness)^2)/thermalDiffusivity


thermalDiffusivity = 1.11*10^(-4) m/s

so for thickness of copper = 1/8 in = 0.00318 m
hence time = 0.0908 s

so for thickness of copper = 1/16 in = 0.00159 m
hence time = 0.0227 s

so for thickness of copper = 0.022 in = 0.000559 m
hence time = 0.0028 s

So, the initial thermal effect on the copper thickness is clearly impulsive, from the point of view of the much slower response of the inverted torsional pendulum (with period ~ 4.5 s)

Great!  Look at the drumhead expansion of the big end .002" copper FRP w/ resistve heating from the Cu loss!

http://en.wikipedia.org/wiki/FR-4

Did the NASA researchers place that polymer composite on the Big Diameter end on purpose to insulate that end and use the copper/PCBoard to create a bimaterial end to maximize thermal waves ?

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=618941;image)

Funny they would not comment about its effect on the experiment.

Maybe they didn't think about it 'cause they were spending too much time thinking of the quantum vacuum, General Relativity, and Mach Effects in comparison with classical effects...

One good thing about Shawer's experiments: he does not seem to have placed insulation on the outside of the big end in his experiments, but his experiments do not show a response first characterized by an impulse, on the contrary, he shows a gradual linear rise

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=618873;image)
Title: Re: EM Drive Developments
Post by: Rodal on 11/01/2014 11:35 pm
A [Date Acquired: Oct 30, 2014] paper co-authored by Dr. White presented at the Institution of Electrical and Electronic Engineers: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf where he discusses short trips to the Jovian and Saturnian moons and "uncovers an energy paradox" (see Appendix A)  ;).

Quote from: White et al
It is not the intent here to detail the theory or engineering of quantum vacuum plasma thrusters (Q-Thrusters). Rather, an overview of the foundational physics and laboratory findings are given.
Q-Thrusters attempt to use the properties of the “quantum vacuum” to propel a spacecraft. Quantum Electrodynamics (QED) predicts that the quantum vacuum (the lowest state of the electromagnetic field) is not empty, but rather a sea of virtual particles and photons that pop into and out of existence stemming from the Heisenberg uncertainty principle.
A number of approaches to utilize this quantum vacuum to transfer momentum from a spacecraft to the vacuum have been synopsized in [1].
A Q-Thruster uses the same principles as conventional plasma thrusters, namely magnetohydrodynamics, where plasma is exposed to crossed electric and magnetic fields which induce a drift of the entire plasma in a direction orthogonal to the applied fields. The difference arises in that a Q-Thruster uses quantum vacuum fluctuations as the “propellant” source, eliminating the need for conventional on-board propellant. A discussion of spacecraft “conservation of energy” is given in Appendix A. Recent laboratory test results [2] indicate the expected thrust-to-power ratio for flight applications could be in the 0.4 – 4.0 N/kWe range, which is one to two orders of magnitude greater than current operational electric thrusters. This combination of characteristics – relatively high specific thrust combined with essentially zero on-board propellant requirement - suggest space mission performance levels significantly exceeding current capabilities.
Title: Re: EM Drive Developments
Post by: RonM on 11/01/2014 11:48 pm
Did the NASA researchers place that polymer composite on the Big Diameter end on purpose to insulate that end and use the copper/PCBoard to create a bimaterial end to maximize thermal waves ?

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=618941;image)

Funny they would not comment about its effect on the experiment.

Maybe they didn't think about it 'cause they were spending too much time thinking of the quantum vacuum, General Relativity, and Mach Effects in comparison with classical effects... Too much time thinking about the speed of light and not enough thinking about the speed of sound

Didn't they do the same thing on the small diameter end? It would have the same effect, but at a different frequency. How would the two ends interact? This could get complicated.
Title: Re: EM Drive Developments
Post by: Rodal on 11/02/2014 12:26 am
Did the NASA researchers place that polymer composite on the Big Diameter end on purpose to insulate that end and use the copper/PCBoard to create a bimaterial end to maximize thermal waves ?

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=618941;image)

Funny they would not comment about its effect on the experiment.

Maybe they didn't think about it 'cause they were spending too much time thinking of the quantum vacuum, General Relativity, and Mach Effects in comparison with classical effects... Too much time thinking about the speed of light and not enough thinking about the speed of sound

Didn't they do the same thing on the small diameter end? It would have the same effect, but at a different frequency. How would the two ends interact? This could get complicated.

The whole truncated cone EM Drive was cantilevered from the Big End, by two bolts holding the bottom of the FRP PCBoard at the Big End.    Thermoelastic waves at the Big End get transmitted from the Big End to the supports to the beam whose tiny displacements are being measured.
Title: Re: EM Drive Developments
Post by: aero on 11/02/2014 01:34 am
This is a little better picture showing the mounting. Looks like the cavity is freely resting on the beam. If it is not securely attached at that point, it might transmit vibration even better than through the cantilever.
Title: Re: EM Drive Developments
Post by: Rodal on 11/02/2014 01:45 am
This is a little better picture showing the mounting. Looks like the cavity is freely resting on the beam. If it is not securely attached at that point, it might transmit vibration even better than through the cantilever.
Yes, it is resting at the center of the beam so it only transmits waves with amplitude down at that location.  Calling that beam longitudinal axis x, that vertically down z motion will impart a rotation around the horizontal y axis perpendicular to the x axis.  The torsional inverted pendulum only has rotational degrees of freedom: rotationally around the vertical z axis (torsion) and rotationally around the x and y axes (swinging of the inverted cantilevered beam).

The bolted FRP at the big end transmits force in the y direction that impart a rotation around the vertical z axis, in the direction being measured by their displacement sensor.
Title: Re: EM Drive Developments
Post by: RonM on 11/02/2014 01:47 am
Wouldn't thermoelastic waves from the small end also cause vibrations that would propagate throughout the device? The copper cone is not going to isolate the two ends. The interaction of vibrations from both ends should produce an interesting pattern.
Title: Re: EM Drive Developments
Post by: Rodal on 11/02/2014 02:01 am
Wouldn't thermoelastic waves from the small end also cause vibrations that would propagate throughout the device? The copper cone is not going to isolate the two ends. The interaction of vibrations from both ends should produce an interesting pattern.
The thermoelastic waves are quickly damped through dispersion (even in the absence of other forms of damping) and here they are also damped by the magnetic damping. 
In most problems there is no such thing as "thermoelastic waves" because the inertial terms are entirely negligible in the great majority of  thermal problems.  Fourier's heat equation does not contain a second order time derivative.  The thermoelastic coupling with the inertial term is usually very negligible.  It only appears in very thin shells or plates.   That's why I asked for an independent assessment of the thickness of the copper before I presented this.  There would not be such a thing as a "thermoelastic wave" if the thickness would be 0.5 inch.  Even in this case it quickly becomes the steady state solution.  Yes, there is some participation from the smaller end, but I expect it to be smaller.
Title: Re: EM Drive Developments
Post by: zen-in on 11/02/2014 02:40 am
The coupling coefficient is non-trivial.  But calculating the Fourier non-dimensional time is trivial, so let's calculate the time for which the Fourier non-dimensional = 1, which is simply ((thickness)^2)/thermalDiffusivity


thermalDiffusivity = 1.11*10^(-4) m/s

so for thickness of copper = 1/8 in = 0.00318 m
hence time = 0.0908 s

so for thickness of copper = 1/16 in = 0.00159 m
hence time = 0.0227 s

so for thickness of copper = 0.022 in = 0.000559 m
hence time = 0.0028 s

So, the initial thermal effect on the copper thickness is clearly impulsive, from the point of view of the much slower response of the inverted torsional pendulum (with period ~ 4.5 s)

Great!  Look at the drumhead expansion of the big end .002" copper FRP w/ resistve heating from the Cu loss!

http://en.wikipedia.org/wiki/FR-4

I need to know the boundary conditions for the 0.002" copper.

Is the 0.002" copper a separate thin sheet of copper, or is the 0.002" copper thermally sprayed on the fiber-reinforced-polymer substrate and hence integrally bonded to it, or is the 0.002" copper adhered to the fiber-reinforced-polymer substrate ?

Can the 0.002" be easily peeled apart from the polymer composite substrate?
(Can one hold on to that 0.002" copper with pliers and peel it apart from the polymer composite substrate?

The single sided Copper FR4 used looks thicker than 1/16".   It may be 3/32" or 1/8" but the Copper is likely not any thicker than .020".   The Copper is heat bonded to the FR4 using a heat curing epoxy.  I base this assumption from my attempts to remove strips of Copper from PCBs.   The Copper has to heated up to about 700 F before trying to peel it off.
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/02/2014 04:14 am
Am I to conclude from the last few posts the thrust produced by the Eagleworks EM drive is in fact a thermoelestic artefact?

Title: Re: EM Drive Developments
Post by: RotoSequence on 11/02/2014 04:30 am
Am I to conclude from the last few posts the thrust produced by the Eagleworks EM drive is in fact a thermoelestic artefact?

We cannot say that. We can say that Rodal's hypothesis is that the Eagleworks EM drive is a thermoelectric artifact, that there is a distinct possibility that it is a thermoelectric artifact, and that Rodal in the process of demonstrating the likelihood of that cause with his analysis.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/02/2014 08:24 am
Am I to conclude from the last few posts the thrust produced by the Eagleworks EM drive is in fact a thermoelestic artefact?

We cannot say that. We can say that Rodal's hypothesis is that the Eagleworks EM drive is a thermoelectric artifact, that there is a distinct possibility that it is a thermoelectric artifact, and that Rodal in the process of demonstrating the likelihood of that cause with his analysis.

There are a number of things going on, some are probably negligible in magnitude (relative to the "signal") and others are not. Luckily we have balance beam's end displacement vs time graphs and there is a lot of information in that. Beyond what we have to complain about, rightly so (as the controversial nature of such experiments needs more instrumental details than casual measures, not less), that should nevertheless be put to the credit of the experimenters team of "anomalous thrust...".

Some of the effects unaccounted for by Brady et al might have very clear temporal signatures in those graphs, making it possible to confirm such effects even with wide error bars on parameters (obviously, the less uncertainty in the parameters the better, but since we have to guess a lot...) by reaching conclusions "in the ballpark" for magnitudes and in qualitative agreement with time aspects (rises/falls aspects, time constants...). Such "rough fits" if they show in the graphs the same parameter dependence as the models (between Brady a b c have different parameters, would the models "predict" the way results change ?) would be a strong indication in favor of such classical spurious effect(s) being the source of the reported "thrust" pulses.

At the moment we have one visually convincing reconstruction of the "thrust vs time" as a simple 2 parameter curve model, which shows that a big part (say between 30% to 50%) of the thrust pulses magnitude is not instantaneous. There is a delay of typical time 5s between the power on of the thruster and this part of the measured thrust, and the same delay is also showing in the decay at power off. As convincing as "real EMdrive theories" can go, none of them (I think) ever could explain such delay. The time constants of electromagnetic energy filling the cavity are more in the ten of µs at most (making it "instantaneous").

I have my idea about the slow rising/falling part as a warm jet of air, heated inside the cavity, dilating and leaking asymmetrically. A number of details must be evaluated, including PCBs elasticity, anisotropies in dissipated power inside the cavities walls, air humidity... only to know what is relevant and what is not, and make correct simplifying assumptions for the "simulations". I won't have much spare time in the coming weeks, don't expect a definite answer from me (on this specific hypothesis of warm air jet) before a month or so. Please be patient. One thing is for sure : it can roughly amounts for both the magnitude and sustained (for 30s or so) of the "slow" component.

Dr Rodal has his idea about how thermoelastic effects could explain the fast rising/decaying part, that might not be that instantaneous but just fast enough. "Brady c" could serve as a confirmation as the fast part is less convincingly instantaneous in this case.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/02/2014 08:29 am
A [Date Acquired: Oct 30, 2014] paper co-authored by Dr. White presented at the Institution of Electrical and Electronic Engineers: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf where he discusses short trips to the Jovian and Saturnian moons and "uncovers an energy paradox" (see Appendix A)  ;).

Quote from: White et al
It is not the intent here to detail the theory or engineering of quantum vacuum plasma thrusters (Q-Thrusters). Rather, an overview of the foundational physics and laboratory findings are given.
Q-Thrusters attempt to use the properties of the “quantum vacuum” to propel a spacecraft. Quantum Electrodynamics (QED) predicts that the quantum vacuum (the lowest state of the electromagnetic field) is not empty, but rather a sea of virtual particles and photons that pop into and out of existence stemming from the Heisenberg uncertainty principle.
A number of approaches to utilize this quantum vacuum to transfer momentum from a spacecraft to the vacuum have been synopsized in [1].
A Q-Thruster uses the same principles as conventional plasma thrusters, namely magnetohydrodynamics, where plasma is exposed to crossed electric and magnetic fields which induce a drift of the entire plasma in a direction orthogonal to the applied fields. The difference arises in that a Q-Thruster uses quantum vacuum fluctuations as the “propellant” source, eliminating the need for conventional on-board propellant. A discussion of spacecraft “conservation of energy” is given in Appendix A. Recent laboratory test results [2] indicate the expected thrust-to-power ratio for flight applications could be in the 0.4 – 4.0 N/kWe range, which is one to two orders of magnitude greater than current operational electric thrusters. This combination of characteristics – relatively high specific thrust combined with essentially zero on-board propellant requirement - suggest space mission performance levels significantly exceeding current capabilities.

Think I got it. At least half of it.

Quoting from Appendix A,"Consider what an inertial observer that is at rest relative to the background radiation would see when considering a spacecraft in our solar system that undergoes a Δ𝑣 of 1 km/s.."

This inertial observer is an artificially contrived situation, so in reality no paradox could exist. It exists on paper. But if one were to create this inertial observer, they would have to expend energy to decelerate the observer from 371km/s to 0km/s wrt the CMB.

This reminds me of a solar system simulator I used to play with a LOT called Celestia. It allowed you to completely stop your motion wrt everything else, and you could see the planets flying at you at enormous speeds. In reality, completely stopping your motion wrt the universe would cost a lot of energy.

The two orders of magnitude too much change in kinetic energy change at the end......still processing.....

So I calculated a loss of 33,648,680,000,000 joules of kinetic energy. The spacecraft gained 1km/s velocity but lost 540kg of mass. So I agree with his change in kinetic energy, even though he didn't state it was a loss of kinetic energy. I get three more zeros in my calcs, so I'm tera not giga on everything. But my math matches him where he got 33,649Gj.

As far as the disparity between energy provided by the power source and change in kinetic energy of the system, 174Gj vs 33,649Gj, he didn't show his work. He just says, "The example spacecraft for our scenario will be a 10,000 kg spacecraft with a power system that provides 10 kWe of power. The electric propulsion system for this example spacecraft will be modeled as Hall-thruster-like with thrust to power of 0.056 N/kWe and a specific impulse of 1838 s. This spacecraft will take 17,370,579 seconds or 201 days to change the velocity of the spacecraft by 1 km/s, and will consume 540 kg of propellant. The amount of energy provided by the power source over this time frame is 174 Gigajoules."

I can only guess he didn't take into account the fact that the craft is losing mass every second it is thrusting, while providing the same constant energy from the power source. Or he is not separating frames of reference, from galactic vs universe.

I think the problem lies in his calc of specific impulse, using the earthly 9.8m/s^2 and atmospheric conditions, which is fine for a rocket on earth, but not when you're out in space. He didn't state whether his specific impulse calcs were sea level or vacuum. It looks like sea level to me.

So he got the thrust velocity wrong. I think he forgot that specific impulse is calculated using the propellant's weight, not mass, and in space that propellant is weightless, yet still has mass. So he has to calculate things differently.

I can tell you that from here:
http://www.strout.net/info/science/delta-v/intro.html
I get the correct result of delta V. See the discussion.

This is why I don't do math.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/02/2014 10:01 am
A [Date Acquired: Oct 30, 2014] paper co-authored by Dr. White presented at the Institution of Electrical and Electronic Engineers: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf where he discusses short trips to the Jovian and Saturnian moons and "uncovers an energy paradox" (see Appendix A)  ;).

Quote from: Joosten & White
.../... the point of this paragraph is to identify that the paradox can be created for any spacecraft using conventional propulsion as well as advanced propulsion.
That ends the appendix A that "addresses" the apparent "issue" of energy conservation. There is no issue : energy conservation is broken every time we fly a rocket. Ok. Let's proceed to more interesting stuff...

Only...

Propellantless

before
     O---->    +energy to spend

after
                O----->

Action/reaction rocket

before

     oo---->   + energy to spend

after
         o-->        o----->
      expelled   

So in the later case, when taking into account the mass_energy of masses, there is energy conservation overall (in any inertial frame). In the former case there is no such conservation as soon as you choose an inertial frame where speed above some threshold.

Said otherwise, in any given arbitrary inertial frame, for the classical rocket to give practical power at constant rate (pushing at constant speed) you have to replenish both energy & reaction mass from the said frame, can't have more energy than you put in. For the propellantless rocket, with thrust/power better than 1/c, then you just have to replenish in energy, and energy is light enough to be communicated from a "rest frame" to the rocket at lower cost than you get back from the rocket pushing.

Perpetual motion of the first kind possible in the propellantles case, not in the classical action/reaction case. Not the same thing. Period.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/02/2014 10:32 am
A [Date Acquired: Oct 30, 2014] paper co-authored by Dr. White presented at the Institution of Electrical and Electronic Engineers: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf where he discusses short trips to the Jovian and Saturnian moons and "uncovers an energy paradox" (see Appendix A)  ;).

Quote from: Joosten & White
.../... the point of this paragraph is to identify that the paradox can be created for any spacecraft using conventional propulsion as well as advanced propulsion.
That ends the appendix A that "addresses" the apparent "issue" of energy conservation. There is no issue : energy conservation is broken every time we fly a rocket. Ok. Let's proceed to more interesting stuff...

Only...

Propellantless

before
     O---->    +energy to spend

after
                O----->

Action/reaction rocket

before

     oo---->   + energy to spend

after
         o-->        o----->
      expelled   

So in the later case, when taking into account the mass_energy of masses, there is energy conservation overall (in any inertial frame). In the former case there is no such conservation as soon as you choose an inertial frame where speed above some threshold.

Said otherwise, in any given arbitrary inertial frame, for the classical rocket to give practical power at constant rate (pushing at constant speed) you have to replenish both energy & reaction mass from the said frame, can't have more energy than you put in. For the propellantless rocket, with thrust/power better than 1/c, then you just have to replenish in energy, and energy is light enough to be communicated from a "rest frame" to the rocket at lower cost than you get back from the rocket pushing.

Perpetual motion of the first kind possible in the propellantles case, not in the classical action/reaction case. Not the same thing. Period.

I'm not seeing it that way. A Hall thruster is not propellant less. He never used the word propellant less to describe the paradox. I see a false paradox, which was created by bad methodology and bad math. 

Now considering a true Q-thruster, which is propellant less. The ship could never be expected to accelerate past a velocity greater than the energy provided by the propulsion system. Even with constant acceleration. Acceleration is constant until max velocity is reached; at some point the kinetic energy of the craft and the energy provided by the propulsion system output would be equal. The propulsion system isn't a perpetual motion machine and has physical limits on amount of power that can be provided, thus ensuring the craft doesn't zoom away towards infinity, violating conservation of energy.

The universe itself provides the rest of the speed limit. C.




Advanced propulsion does not equal propellant less propulsion. Advanced propulsion is ion thrusters and similar junk to Nasa. This is the parlance they go by.

Breakthrough propulsion is propellant less propulsion.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/02/2014 10:48 am
Ok first we're gonna draw little mustaches on our electrons, then use them to interact with the QV through the dielectric: :o

http://www.quantumdiaries.org/2011/06/19/helicity-chirality-mass-and-the-higgs/
http://physics.unl.edu/~tgay/content/CPE.html

Still looking for a way past the "one way check valve" that allows the QV to interact with me, but doesn't allow me to interact with the QV.

Probably a dead end since the Higgs is spin 0, but interesting nonetheless.
Seriously this is good stuff.

Title: Re: EM Drive Developments
Post by: frobnicat on 11/02/2014 11:12 am

I'm not seeing it that way. A Hall thruster is not propellant less. He never used the word propellant less to describe the paradox. I see a false paradox, which was created by bad methodology and bad math.

Advanced propulsion does not equal propellant less propulsion.

"One of the issues to consider for a constant thrust system is the matter of conservation of energy."
You can't have constant thrust with action/reaction scheme, because there can be a constant expelled mass flow for only so long. So for me this is broadly "we are talking about propellantless propulsion". And indeed any such propellantless scheme has an issue of energy conservation. In the terminology of this appendix, the Hall thruster is conventional, the EMdrive (propellantless whatever) is advanced.

I see another spectacularly failed attempt at addressing the intrinsic issue with energy conservation of propellantless schemes, as bad as Shawyer's. Any serious physicist/engineer reading this appendix A will immediately see the plain absurdity of the argument, one way or another. This is not serious.

Propellantless scheme with better than 1/c thrust/power : either the ship taps into some energy source outside of it, or it is on its own energy and it uses tachyons. http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275281#msg1275281
A classical action/reaction scheme needs neither energy source exterior to ship nor tachyons to be energy conservative. The expelled mass that's used to get better than 1/c thrust/mass had to be accelerated at the given speed first is another way to see it, this kinetic energy of expelled mass (at the moment it is expelled) is sacrificed as well as the energy taken to give it velocity relative to ship's frame.
Title: Re: EM Drive Developments
Post by: Rodal on 11/02/2014 11:23 am

I'm not seeing it that way. A Hall thruster is not propellant less. He never used the word propellant less to describe the paradox. I see a false paradox, which was created by bad methodology and bad math.

Advanced propulsion does not equal propellant less propulsion.

"One of the issues to consider for a constant thrust system is the matter of conservation of energy."
You can't have constant thrust with action/reaction scheme, because there can be a constant expelled mass flow for only so long. So for me this is broadly "we are talking about propellantless propulsion". And indeed any such propellantless scheme has an issue of energy conservation. In the terminology of this appendix, the Hall thruster is conventional, the EMdrive (propellantless whatever) is advanced.

I see another spectacularly failed attempt at addressing the intrinsic issue with energy conservation of propellantless schemes, as bad as Shawyer's. Any serious physicist/engineer reading this appendix A will immediately see the plain absurdity of the argument, one way or another. This is not serious.

What is most perplexing is that this report follows the "Anomalous..." Brady experiment report.  It continues to insist on explaining the experimental results as being the result of the Quantum Vacuum of electron-positron virtual particles acting like a plasma that can be modeled with magnetohydrodynamics.  It has not backed down at all from that claim, which remains entirely unsupported: it does not add any support to it.  It takes for granted that these microwave propellant less thrusters work based on the Quantum Vacuum, it does not address the criticisms from the scientific community (except energy conservation by now creating a paradox questioning energy conservation ?) that has been raised against those claims and continues to build on this unsupported claim by further discussion of trips to the Jovian and Saturnian moons.

I would have expected instead to address the criticisms about the Quantum Vacuum hypothesis and to further analyze the tests and to comment on future tests. 

I would have expected an effort to analyze the anomalous experimental results instead of trips to Enceladus with a propellant-less drive that has never been shown to operate in flight.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/02/2014 11:38 am

I'm not seeing it that way. A Hall thruster is not propellant less. He never used the word propellant less to describe the paradox. I see a false paradox, which was created by bad methodology and bad math.

Advanced propulsion does not equal propellant less propulsion.

"One of the issues to consider for a constant thrust system is the matter of conservation of energy."
You can't have constant thrust with action/reaction scheme, because there can be a constant expelled mass flow for only so long. So for me this is broadly "we are talking about propellantless propulsion". And indeed any such propellantless scheme has an issue of energy conservation. In the terminology of this appendix, the Hall thruster is conventional, the EMdrive (propellantless whatever) is advanced.

I see another spectacularly failed attempt at addressing the intrinsic issue with energy conservation of propellantless schemes, as bad as Shawyer's. Any serious physicist/engineer reading this appendix A will immediately see the plain absurdity of the argument, one way or another. This is not serious.

Propellantless scheme with better than 1/c thrust/power : either the ship taps into some energy source outside of it, or it is on its own energy and it uses tachyons. http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275281#msg1275281
A classical action/reaction scheme needs neither energy source exterior to ship nor tachyons to be energy conservative. The expelled mass that's used to get better than 1/c thrust/mass had to be accelerated at the given speed first is another way to see it, this kinetic energy of expelled mass (at the moment it is expelled) is sacrificed as well as the energy taken to give it velocity relative to ship's frame.
Ok I'm getting ya. The energy budget (right term? meaning it stores well and doesn't take up a huge volume/and is easier to refuel..solar sails, batteries, reactors....)of a propellantless system is fantastic but they aren't perpetual motion machines. They run out of juice and need recharging just as a classical action/reaction rocket runs out of fuel and needs topped off. Tomato/tomaaato. I don't see any paradox.
Title: Re: EM Drive Developments
Post by: Rodal on 11/02/2014 11:42 am

Great!  Look at the drumhead expansion of the big end .002" copper FRP w/ resistve heating from the Cu loss!

http://en.wikipedia.org/wiki/FR-4

I need to know the boundary conditions for the 0.002" copper.

Is the 0.002" copper a separate thin sheet of copper, or is the 0.002" copper thermally sprayed on the fiber-reinforced-polymer substrate and hence integrally bonded to it, or is the 0.002" copper adhered to the fiber-reinforced-polymer substrate ?

Can the 0.002" be easily peeled apart from the polymer composite substrate?
(Can one hold on to that 0.002" copper with pliers and peel it apart from the polymer composite substrate?

The single sided Copper FR4 used looks thicker than 1/16".   It may be 3/32" or 1/8" but the Copper is likely not any thicker than .020".   The Copper is heat bonded to the FR4 using a heat curing epoxy.  I base this assumption from my attempts to remove strips of Copper from PCBs.   The Copper has to heated up to about 700 F before trying to peel it off.

See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1279402#msg1279402

Quote from: Notsosureofit
For what it's worth, I measure the FRP board at 0.060" and the copper cladding at 0.002". (the stuff I have here anyway)
Title: Re: EM Drive Developments
Post by: Mulletron on 11/02/2014 11:56 am
The QV thrust scenario is the only method available to justify measuring thrust from an otherwise sealed rf cavity and still say that momentum was conserved. Now people can argue that the QV doesn't exist or it is magic or whatever, but they are wrong on both counts. Magic doesn't exist and the QV does. Every field has a ground state and that is the QV. Not even worth trying to defend that the QV exists because the literature is rich and deep enough and goes all the way back to the Lamb Shift up to the present day. Did I mention that MiHsC has Casimir right in the name? Casimir and the QV are two peas in a pod. An all pervasive field is not such a leap, as the scalar Higgs field is a prime example of an all pervasive field and one of its associated excitation particles, the Higgs Boson has been confirmed. Even the Higgs field itself has a vacuum component, aka the vev of the Higgs field.

http://gravityandlevity.wordpress.com/2013/04/24/the-lamb-shift/

It is a clear as this: Those who believe that empty copper cans are exhibiting thrust are being fooled by artifact effects.

Is anybody here still on board with Quantum Thrusters?

On a separate note, why do the Pioneer probes get to lose inertial mass as they fly away from the solar system, but photons get to gain inertial mass (which they can't anyway, but lets pretend they can) by the same rationale?
http://arxiv.org/abs/astro-ph/0612599
Now that is a paradox.

Solution. Since you can't modify the inertial mass of light because photons are massless and speed invariant, look at what else is in the cavity which has mass and is not speed invariant. The STUFF in the cavity. The air and the dielectric. The stuff in the cavity is enjoying much less interaction with the outside world thanks to being surrounded by a copper can blocking that interaction, which means if we're going to modify the inertia of anything (which the possibility of doing so is debatable, but I and others support that we can) we should focus on that stuff instead. Not the light. We can't mess with light and not get laughed at. We can't mess with the invariant mass of massive particles and its associated invariant inertial mass, but if MiHsC holds true, we can mess with the remainder inertia, modified by interaction...Unruh, EM, whatever....if such remainder exists. I hold that such a remainder does exist due to what I've learned about superfluids and meta materials.

Title: Re: EM Drive Developments
Post by: MikeMcCulloch on 11/02/2014 02:45 pm
I'd just like to clear up a couple of misunderstandings. To answer your red text: the Pioneer probes lose inertia according to MiHsC since they're moving out to lower accelerations, see longer Unruh waves, so a greater proportion of those waves are disallowed by the Hubble horizon. In the emdrive the difference is that the horizon itself changes from end to end. Both predictions are consistent with MiHsC, given the assumptions made. As for photons, special relativity (and experiment) say they have inertial mass. It is their rest mass that's zero. So it is logical and consistent to try and apply MiHsC to them. Can this be done in a way that still satisfies all the experiments performed to date? I don't know, but I'm curious about it..
Title: Re: EM Drive Developments
Post by: Mulletron on 11/02/2014 03:22 pm
I'd just like to clear up a couple of misunderstandings. To answer your red text: the Pioneer probes lose inertia according to MiHsC since they're moving out to lower accelerations, see longer Unruh waves, so a greater proportion of those waves are disallowed by the Hubble horizon. In the emdrive the difference is that the horizon itself changes from end to end. Both predictions are consistent with MiHsC, given the assumptions made. As for photons, special relativity (and experiment) say they have inertial mass. It is their rest mass that's zero. So it is logical and consistent to try and apply MiHsC to them. Can this be done in a way that still satisfies all the experiments performed to date? I don't know, but I'm curious about it..

Sir thank you and I will think hard about what you are saying about the inside of the emdrive.

But please see above where I said, "you can't modify the inertial mass of light because photons are massless and speed invariant." The issue is about applying MiHsC to a constant. Modifying a constant. Not whether or not photons have inertial mass.

Indeed light changes direction by gravitational effects and is red shifted by similar effects, showing signs of inertia like behavior due to the momentum which photons carry, the underlying behavior of light remains the same and isn't subject to modification; the fundamental constant of C remains the same and cannot be modified.
Title: Re: EM Drive Developments
Post by: Rodal on 11/02/2014 04:12 pm
I'd just like to clear up a couple of misunderstandings. To answer your red text: the Pioneer probes lose inertia according to MiHsC since they're moving out to lower accelerations, see longer Unruh waves, so a greater proportion of those waves are disallowed by the Hubble horizon. In the emdrive the difference is that the horizon itself changes from end to end. Both predictions are consistent with MiHsC, given the assumptions made. As for photons, special relativity (and experiment) say they have inertial mass. It is their rest mass that's zero. So it is logical and consistent to try and apply MiHsC to them. Can this be done in a way that still satisfies all the experiments performed to date? I don't know, but I'm curious about it..

Confining myself here only to the specific discussion (and not to MiHsC) of the statement that "photons are speed invariant."  This statement is incorrect in general and contrary to what I was taught at MIT.  It is well known that light travels at different speed in different media:  Experiments show, that single photons travel through glass at the group velocity of light, which can be quite different from the speed of light in vacuum.
It is classical (Newtonian corpuscular theory) mechanics that demands that the momentum of the photons be greater in water than in air, but  measurements show that the opposite relationship holds for their velocity.

The view that photons are particles whose speed is invariant in any media and under all conditions is contradicted also by these recent experiments revealing a new state made possible with photons: 

http://www.princeton.edu/engineering/news/archive/?id=13459
https://journals.aps.org/prx/pdf/10.1103/PhysRevX.4.031043

I think that there is a confusion in the statement between the constant "c" (that of course, indeed, is an invariant constant) from  General Relativity and the quantum description of photons in Quantum Mechanics.

General Relativity does not deal with individual photons.  Photons are described by Quantum Mechanics.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/02/2014 04:18 pm
I'd just like to clear up a couple of misunderstandings. To answer your red text: the Pioneer probes lose inertia according to MiHsC since they're moving out to lower accelerations, see longer Unruh waves, so a greater proportion of those waves are disallowed by the Hubble horizon. In the emdrive the difference is that the horizon itself changes from end to end. Both predictions are consistent with MiHsC, given the assumptions made. As for photons, special relativity (and experiment) say they have inertial mass. It is their rest mass that's zero. So it is logical and consistent to try and apply MiHsC to them. Can this be done in a way that still satisfies all the experiments performed to date? I don't know, but I'm curious about it..

Confining myself here only to the specific discussion (and not to MiHsC) of the statement that "photons are speed invariant."  This statement is incorrect in general and contrary to what I was taught at MIT.  It is well known that light travels at different speed in different media:  Experiments show, that single photons travel through glass at the group velocity of light, which can be quite different from the speed of light in vacuum.
It is classical (Newtonian) mechanics that demands that the momentum of the photons be greater in water than in air, but  measurements show that the opposite relationship holds for their velocity.

The view that photons are particles whose speed is invariant in any media and under all conditions is contradicted also by these recent experiments revealing a new state made possible with photons: 

http://www.princeton.edu/engineering/news/archive/?id=13459
https://journals.aps.org/prx/pdf/10.1103/PhysRevX.4.031043

I think that there is a confusion in the statement between the constant "c" (that of course, indeed, is an invariant constant) from  General Relativity and the quantum description of photons in Quantum Mechanics.

General Relativity does not deal with quantum particles like photons.  Particles like photons are described by Quantum Mechanics.

Group and phase velocity of light aren't the speed of light. They can even exceed the speed of light. Group and phase velocity change quite frequently depending on the medium light is in and transferring to/from.

Need I remind you that inside of a medium, most of that space is vacuum. The apparent slowing of light is simply the absorption and emission of light/photons when it encounters atoms. That does not change the speed of light. C is a constant. It is no coincidence that the invariance of c is linked to causality. As violating that constant would also violate cause and effect.
Title: Re: EM Drive Developments
Post by: Rodal on 11/02/2014 09:40 pm
The following shows, for the torsional inverted pendulum at NASA Eagleworks, that harmonic forcing functions with small enough period (= high enough frequency) are undistinguishable (due to the pendulum response) from a rectangular impulse forcing function




See http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281244#msg1281244

The time for which the Fourier non-dimensional = 1,  is simply ((thickness)^2)/thermalDiffusivity


thermalDiffusivity = 1.11*10^(-4) m/s

so for thickness of copper = 1/8 in = 0.00318 m
hence time = 0.0908 s



One can see below the forcing function with a period 0.0908 s (equal to the Fourier non-dimensional time for a copper sheet 1/8 in) gives a response which is indistinguishable from a rectangular impulse.

For the torsional inverted pendulum at NASA Eagleworks, any period of vibration smaller than 0.2 seconds has a response which is unrecognizable from a rectangular impulse.

FORCING FUNCTION = 2 ((Sin[Pi* t/tau])^2) is the square of a sinusoid
Title: Re: EM Drive Developments
Post by: hop on 11/02/2014 10:59 pm
On a separate note, why do the Pioneer probes get to lose inertial mass as they fly away from the solar system, ...
The so called "Pioneer anomaly" is very well explained by very ordinary physics: http://arxiv.org/abs/1204.2507
Title: Re: EM Drive Developments
Post by: frobnicat on 11/02/2014 11:33 pm
Next batch of scraped data from figure 19 page 15 of "anomalous thrust..." from Brady et al (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf). The top (result1.txt) and middle (result2.txt) graphs are scraped.

Same caveats as previously posted (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281007#msg1281007). For first curve (top figure 19) I removed the (non existent) flat last sampled data of the previous version to avoid artefacts when analysing with filters.

Each line of those files is the value in µN at each .1 s interval (linearly interpolated from manual reconstruction). The vertical scale were roughly given by the calibration pulses at about 30µN (expect no more than 5% precision). Absolute values are arbitrary (because of the drifting baseline). Horizontal scale given by the indication of 196 s for the whole display graph window of the pictures.

Will proceed with other graphs when time permits. Will post attempts at original signal reconstruction : thrust(t) while what we see is only balance displacement(t). Since the balance is underdamped, a lot can hide behind those oscillations and drifts in position.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/02/2014 11:46 pm
@Rodal, a question of definition :

You often mention "torsional inverted pendulum". I fail to see in what we have an inverted pendulum here (with Eagleworks balance). Isn't an inverted pendulum a device that is kept close to a situation of unstable equilibrium ? I understand how the nonlinear couplings with different axis of rotation/displacement with flexure bearings can make chaos, but around the principal movement of rotation around z we are quite stable with the spring restoring torque, aren't we ?
Title: Re: EM Drive Developments
Post by: Rodal on 11/03/2014 01:40 am
@Rodal, a question of definition :

You often mention "torsional inverted pendulum". I fail to see in what we have an inverted pendulum here (with Eagleworks balance). Isn't an inverted pendulum a device that is kept close to a situation of unstable equilibrium ? I understand how the nonlinear couplings with different axis of rotation/displacement with flexure bearings can make chaos, but around the principal movement of rotation around z we are quite stable with the spring restoring torque, aren't we ?

Since the stiffness of the swinging beam overwhelms the gravity contribution, it doesn't really make a difference whether this type of pendulum would be upright or inverted.    I have been calling inverted torsional pendulum because it has the same construction as an inverted torsional pendulums used for measurements: a beam that is stiff enough that its stiffness overwhelms the effect of gravity.

It has all these known problems associated with inverted torsional pendulums:

1) This pendulum's swinging periods (and frequencies) instead of being simply determined by the length of a pendulum string and the force of gravity (as in a regular pendulum), are determined by the bending stiffness of a vertically cantilevered beam and its stiffness of clamping.

2) The exact periods (and frequencies) of swinging vibration of this pendulum are given by uncertain to ascertain variables as the amount of stiffness fixation at the cantilevered end, and to a lesser extent the bending moment of inertia and modulus of the beam.

3) As opposed to a simple pendulum, this pendulum's swinging modes of vibration are infinite in number (the infinite number of modes of swinging vibration of a cantilevered beam).

4) In a simple hanging pendulum, the neutral location is simply dictated by gravity.  In this pendulum the neutral location of the pendulum is dictated by the (unknown beforehand) neutral position of the (stiff) un-strained beam.

5) The neutral position of the center of rotation of this pendulum can be affected by differential temperatures (producing thermal curvature of the beam). This does not happen in a regular pendulum (all that temperature can do is to stretch or shrink the length of the pendulum which is usually a much smaller ).

6) Due to the fact that the beam (whose angular rotation around the vertical axis z is being measured) needs to be simultaneously clamped for swinging motions, the stiffness in torsional, rotational motion around the z axis is very dependent on the total load mounted on the pendulum.  This is a bad feature and that's probably why Eagleworks had to resort to another method to calibrate the relationship between torsional force and angular rotation for every test.

These (and others) are all good reasons to differentiate the Eagleworks pendulum from regular hanging pendulums.

How would you prefer to name this pendulum and why would you prefer to give it another name?

I see that Wikipedia has an article on inverted pendulums that are close to instability, but that article does not discuss measurement devices or torsional pendulums.  I am not aware of inverted torsional pendulums used for measurement purposes having been intentionally made close to vertical static instability. It seems to me that this type of pendulum has enough problems already for measurement purposes to intentionally want to make it worse by making it vertically unstable due to gravity.  Why would one want to make a torsional flexural pendulum for measurement purposes intentionally close to static instability ?

Am I missing something?

PS: I am aware that regular hanging pendulums also have a few other modes of vibration: bouncing (usually quite negligible), precession of the plane of oscillation, etc.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 06:20 am
Revisited this Feigel paper from 2003 in more detail; attached. Page 3 is especially compelling and echoes the later Donaire, Tiggelen, Rikken (publications linked to below) paper discussed back around page 126. A quote from the Feigel paper to raise eyebrows:

"Thus modification of the modes by matter can alter the momentum of the vacuum. The latter generally vanishes due to counter propagating modes that cancel each other’s contribution. This situation can be different however in materials that are temporally and spatially asymmetric."

http://lpm2c.grenoble.cnrs.fr/spip.php?page=publications&id_auteur=18&clepubli=van%20Tiggelen&lang=fr
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/03/2014 12:49 pm
Revisited this Feigel paper from 2003 in more detail; attached. Page 3 is especially compelling and echoes the later Donaire, Tiggelen, Rikken (publications linked to below) paper discussed back around page 126. A quote from the Feigel paper to raise eyebrows:

"Thus modification of the modes by matter can alter the momentum of the vacuum. The latter generally vanishes due to counter propagating modes that cancel each other’s contribution. This situation can be different however in materials that are temporally and spatially asymmetric."

http://lpm2c.grenoble.cnrs.fr/spip.php?page=publications&id_auteur=18&clepubli=van%20Tiggelen&lang=fr

Taken at face value, this could add a momentum kick to the air (and/or dielectric) every half-cycle.   How to calculate the momentum added in that case ?

Reminds me once again, of the "optimized" NASA cone that we don't know the code for.

See also news today:  http://www.laboratoryequipment.com/news/2014/11/two-photons-interact-using-ultra-thin-glass

Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 05:07 pm
Revisited this Feigel paper from 2003 in more detail; attached. Page 3 is especially compelling and echoes the later Donaire, Tiggelen, Rikken (publications linked to below) paper discussed back around page 126. A quote from the Feigel paper to raise eyebrows:

"Thus modification of the modes by matter can alter the momentum of the vacuum. The latter generally vanishes due to counter propagating modes that cancel each other’s contribution. This situation can be different however in materials that are temporally and spatially asymmetric."

http://lpm2c.grenoble.cnrs.fr/spip.php?page=publications&id_auteur=18&clepubli=van%20Tiggelen&lang=fr

Taken at face value, this could add a momentum kick to the air (and/or dielectric) every half-cycle.   How to calculate the momentum added in that case ?

Reminds me once again, of the "optimized" NASA cone that we don't know the code for.

See also news today:  http://www.laboratoryequipment.com/news/2014/11/two-photons-interact-using-ultra-thin-glass

Indeed momentum can be transferred but there must be an asymmetry present in the system. Actually two. Without broken symmetries, there is an equal push/pull with each half cycle, amounting to zero. Since we're dealing with conservation of momentum and conservation of energy, we must create an asymmetry in the discrete P and T symmetries in order to get any work done, aka thrust. It is known that the discrete symmetry of parity is broken in everyday life. See Wu experiment 1957 Nobel Prize. There is evidence that T symmetry is broken at least once too; http://www2.lbl.gov/abc/wallchart/chapters/05/2.html (see bottom 1964 "direct T violations") Now some perspective is required. Just because a single instance of P or T symmetry violation has been found in some interaction; that doesn't mean that those symmetries are broken everywhere. It does show precedent. Which means it is possible to be broken in other ways. That is a major caveat. This also doesn't mean that since P or T was broken, that they are broken together, which they must be for casimir momemtum transfer to be real (so they say, but who am I to argue, but I do agree because I understand the connection between symmetries and conservations). I'm playing Sherlock Holmes here more than Einstein. PT symmetry must be broken simultaneously. Chirality regularly breaks P symmetry. This presentation, slide 20: http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf (thank you Rodal for finding this) suggests that T symmetry is also broken in the fashion described, but most importantly P and T can be broken simultaneously (section III quantum approach). I have also postulated that a chiral dielectric molecule present in an asymmetric spacetime (inside the conical frustum) will also simultaneously break PT symmetry, but have not formalized my ideas and it is not worthy of being called a hypothesis, thus it is just a crazy idea I have. I acknowledge this. Be that as it may, I hope that someone smarter than I am will be inspired and take the idea and run with it. I don't care about being right. I just care about the science. And I want my bleepin' hovercar and for my boy to get to Mars.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/03/2014 05:35 pm
Revisited this Feigel paper from 2003 in more detail; attached. Page 3 is especially compelling and echoes the later Donaire, Tiggelen, Rikken (publications linked to below) paper discussed back around page 126. A quote from the Feigel paper to raise eyebrows:

"Thus modification of the modes by matter can alter the momentum of the vacuum. The latter generally vanishes due to counter propagating modes that cancel each other’s contribution. This situation can be different however in materials that are temporally and spatially asymmetric."

http://lpm2c.grenoble.cnrs.fr/spip.php?page=publications&id_auteur=18&clepubli=van%20Tiggelen&lang=fr

Taken at face value, this could add a momentum kick to the air (and/or dielectric) every half-cycle.   How to calculate the momentum added in that case ?

Reminds me once again, of the "optimized" NASA cone that we don't know the code for.

See also news today:  http://www.laboratoryequipment.com/news/2014/11/two-photons-interact-using-ultra-thin-glass

Indeed momentum can be transferred but there must be an asymmetry present in the system. Actually two. Without broken symmetries, there is an equal push/pull with each half cycle, amounting to zero. Since we're dealing with conservation of momentum and conservation of energy, we must create an asymmetry in the discrete P and T symmetries in order to get any work done, aka thrust. It is known that the discrete symmetry of parity is broken in everyday life. See Wu experiment 1957 Nobel Prize. There is evidence that T symmetry is broken at least once too; http://www2.lbl.gov/abc/wallchart/chapters/05/2.html (see bottom 1964 "direct T violations") Now some perspective is required. Just because a single instance of P or T symmetry violation has been found in some interaction; that doesn't mean that those symmetries are broken everywhere. It does show precedent. Which means it is possible to be broken in other ways. That is a major caveat. This also doesn't mean that since P or T was broken, that they are broken together, which they must be for casimir momemtum transfer to be real (so they say, but who am I to argue, but I do agree because I understand the connection between symmetries and conservations). I'm playing Sherlock Holmes here more than Einstein. PT symmetry must be broken simultaneously. Chirality regularly breaks P symmetry. This presentation, slide 20: http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf (thank you Rodal for finding this) suggests that T symmetry is also broken in the fashion described, but most importantly P and T can be broken simultaneously. I have also postulated that a chiral dielectric molecule present in an asymmetric spacetime (inside the conical frustum) will also simultaneously break PT symmetry, but have not formalized my ideas and it is not worthy of being called a hypothesis, thus it is just a crazy idea I have. I acknowledge this. Be that as it may, I hope that someone smarter than I am will be inspired and take the idea and run with it. I don't care about being right. I just care about the science. And I want my bleepin' hovercar and for my boy to get to Mars.

Well, maybe, but I tend to settle in around equation (16).  The wavelengths here are of the order of the cavity size.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/03/2014 05:42 pm
Sorry for asking, but -as the discussion is getting very technical- could someone of you make a quick update for the non-physicists among us (like myself)? is there any tangible progress, or has the device been demistified once for all?

thanks! :)

Hi there.

I wouldn't put much stock in the ostensibly technical speculations that fill this thread. The results are certainly wrong and are in clear violations of macroscopic conservation of momentum. All explanations or "models" proposed to explain this (quantum plasma, virtual particles, etc.) are all based on incredibly bad physics.

Any signal these experimenters find is almost certainly due to a terrible experimental method and questionable data analysis.

As far as I can tell, along with the greater physics and engineering communities (from what I have seen), this is a fantasy device.
How many of the five competing models to explain thrust from these devices are you familiar with?  I happen to agree with you about QVF and virtual particles, but there are 5 models to choose from and that's one.
Title: Re: EM Drive Developments
Post by: Rodal on 11/03/2014 05:54 pm
......

Hi there.

I wouldn't put much stock in the ostensibly technical speculations that fill this thread. The results are certainly wrong and are in clear violations of macroscopic conservation of momentum. All explanations or "models" proposed to explain this (quantum plasma, virtual particles, etc.) are all based on incredibly bad physics.

Any signal these experimenters find is almost certainly due to a terrible experimental method and questionable data analysis.

As far as I can tell, along with the greater physics and engineering communities (from what I have seen), this is a fantasy device.
How many of the five competing models to explain thrust from these devices are you familiar with?  I happen to agree with you about QVF and virtual particles, but there are 5 models to choose from and that's one.

Here is his (Supergravity's) opinion on Woodward's theory:  http://forum.nasaspaceflight.com/index.php?topic=31037.msg1065368#msg1065368, which Supergravity has discussed at length in that thread dedicated to Woodward's thread.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 05:56 pm
Revisited this Feigel paper from 2003 in more detail; attached. Page 3 is especially compelling and echoes the later Donaire, Tiggelen, Rikken (publications linked to below) paper discussed back around page 126. A quote from the Feigel paper to raise eyebrows:

"Thus modification of the modes by matter can alter the momentum of the vacuum. The latter generally vanishes due to counter propagating modes that cancel each other’s contribution. This situation can be different however in materials that are temporally and spatially asymmetric."

http://lpm2c.grenoble.cnrs.fr/spip.php?page=publications&id_auteur=18&clepubli=van%20Tiggelen&lang=fr

Taken at face value, this could add a momentum kick to the air (and/or dielectric) every half-cycle.   How to calculate the momentum added in that case ?

Reminds me once again, of the "optimized" NASA cone that we don't know the code for.

See also news today:  http://www.laboratoryequipment.com/news/2014/11/two-photons-interact-using-ultra-thin-glass

Indeed momentum can be transferred but there must be an asymmetry present in the system. Actually two. Without broken symmetries, there is an equal push/pull with each half cycle, amounting to zero. Since we're dealing with conservation of momentum and conservation of energy, we must create an asymmetry in the discrete P and T symmetries in order to get any work done, aka thrust. It is known that the discrete symmetry of parity is broken in everyday life. See Wu experiment 1957 Nobel Prize. There is evidence that T symmetry is broken at least once too; http://www2.lbl.gov/abc/wallchart/chapters/05/2.html (see bottom 1964 "direct T violations") Now some perspective is required. Just because a single instance of P or T symmetry violation has been found in some interaction; that doesn't mean that those symmetries are broken everywhere. It does show precedent. Which means it is possible to be broken in other ways. That is a major caveat. This also doesn't mean that since P or T was broken, that they are broken together, which they must be for casimir momemtum transfer to be real (so they say, but who am I to argue, but I do agree because I understand the connection between symmetries and conservations). I'm playing Sherlock Holmes here more than Einstein. PT symmetry must be broken simultaneously. Chirality regularly breaks P symmetry. This presentation, slide 20: http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf (thank you Rodal for finding this) suggests that T symmetry is also broken in the fashion described, but most importantly P and T can be broken simultaneously. I have also postulated that a chiral dielectric molecule present in an asymmetric spacetime (inside the conical frustum) will also simultaneously break PT symmetry, but have not formalized my ideas and it is not worthy of being called a hypothesis, thus it is just a crazy idea I have. I acknowledge this. Be that as it may, I hope that someone smarter than I am will be inspired and take the idea and run with it.

When the author writes << This situation can be different however in materials that are temporally and spatially asymmetric.>> the author is explicitly discussing material asymmetry, what is known scientifically as anisotropy or aelotropy: different material properties in different intrinsic (materially embedded) directions.  This should not be confused with asymmetrical geometry of an isotropic material. 

Moreover, the author requires a specific type of anisotropy: helical anisotropy, a type of anisotropy found in some (chiral) polymer chains, but unusual in a macro sample (typical fabrication methods like injection molding result in isotropic macro samples even when the polymer chains are chiral).

The materials used in the EM Drives (copper) and the polymer dielectrics (Teflon and Polyethylene) are isotropic homogeneous materials and hence do not satisfy the condition required by the author.

Well a quick fact check on what you are saying finds no mention of the word "helical" or "anisotrop" or "anisotropic' or "anisotropy" in either publication. So it sounds like that is your interpretation not the information reported.........am I sensing obstructionism?

Did I mention that some polymers exhibit unplanned helical twist in their melt phase at production (which is known) isn't present for all polymers? This isn't an assumption that can be made and applied to all extruded plastic polymer dielectrics. Nor did the authors invoke this.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/03/2014 05:56 pm

I'm not seeing it that way. A Hall thruster is not propellant less. He never used the word propellant less to describe the paradox. I see a false paradox, which was created by bad methodology and bad math.

Advanced propulsion does not equal propellant less propulsion.

"One of the issues to consider for a constant thrust system is the matter of conservation of energy."
You can't have constant thrust with action/reaction scheme, because there can be a constant expelled mass flow for only so long. So for me this is broadly "we are talking about propellantless propulsion". And indeed any such propellantless scheme has an issue of energy conservation. In the terminology of this appendix, the Hall thruster is conventional, the EMdrive (propellantless whatever) is advanced.

I see another spectacularly failed attempt at addressing the intrinsic issue with energy conservation of propellantless schemes, as bad as Shawyer's. Any serious physicist/engineer reading this appendix A will immediately see the plain absurdity of the argument, one way or another. This is not serious.

What is most perplexing is that this report follows the "Anomalous..." Brady experiment report.  It continues to insist on explaining the experimental results as being the result of the Quantum Vacuum of electron-positron virtual particles acting like a plasma that can be modeled with magnetohydrodynamics.  It has not backed down at all from that claim, which remains entirely unsupported: it does not add any support to it.  It takes for granted that these microwave propellant less thrusters work based on the Quantum Vacuum, it does not address the criticisms from the scientific community (except energy conservation by now creating a paradox questioning energy conservation ?) that has been raised against those claims and continues to build on this unsupported claim by further discussion of trips to the Jovian and Saturnian moons.

I would have expected instead to address the criticisms about the Quantum Vacuum hypothesis and to further analyze the tests and to comment on future tests. 

I would have expected an effort to analyze the anomalous experimental results instead of trips to Enceladus with a propellant-less drive that has never been shown to operate in flight.
This is the way QVF and ZPF before it have always been.  There has never been an attempt to answer the objections about how they predict the wrong mass for the proton, or violate EEP and GR.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/03/2014 06:04 pm
The QV thrust scenario is the only method available to justify measuring thrust from an otherwise sealed rf cavity and still say that momentum was conserved.
I'm sorry but that's not true.  M-E theory makes such an explanation and QVF model does not.  Sonny clearly owns that he is proposing a violation of conservation whereas M-E theory does not require this.

The point however in regards to M-E is that though the cavity is sealed, in M-E theory it is part of the larger system including all the mass in the universe.  You cannot talk about conservation in open systems and the M-E system is the universe under all circumstances.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 06:07 pm

I'm not seeing it that way. A Hall thruster is not propellant less. He never used the word propellant less to describe the paradox. I see a false paradox, which was created by bad methodology and bad math.

Advanced propulsion does not equal propellant less propulsion.

"One of the issues to consider for a constant thrust system is the matter of conservation of energy."
You can't have constant thrust with action/reaction scheme, because there can be a constant expelled mass flow for only so long. So for me this is broadly "we are talking about propellantless propulsion". And indeed any such propellantless scheme has an issue of energy conservation. In the terminology of this appendix, the Hall thruster is conventional, the EMdrive (propellantless whatever) is advanced.

I see another spectacularly failed attempt at addressing the intrinsic issue with energy conservation of propellantless schemes, as bad as Shawyer's. Any serious physicist/engineer reading this appendix A will immediately see the plain absurdity of the argument, one way or another. This is not serious.

What is most perplexing is that this report follows the "Anomalous..." Brady experiment report.  It continues to insist on explaining the experimental results as being the result of the Quantum Vacuum of electron-positron virtual particles acting like a plasma that can be modeled with magnetohydrodynamics.  It has not backed down at all from that claim, which remains entirely unsupported: it does not add any support to it.  It takes for granted that these microwave propellant less thrusters work based on the Quantum Vacuum, it does not address the criticisms from the scientific community (except energy conservation by now creating a paradox questioning energy conservation ?) that has been raised against those claims and continues to build on this unsupported claim by further discussion of trips to the Jovian and Saturnian moons.

I would have expected instead to address the criticisms about the Quantum Vacuum hypothesis and to further analyze the tests and to comment on future tests. 

I would have expected an effort to analyze the anomalous experimental results instead of trips to Enceladus with a propellant-less drive that has never been shown to operate in flight.
This is the way QVF and ZPF before it have always been.  There has never been an attempt to answer the objections about how they predict the wrong mass for the proton, or violate EEP and GR.

I can't argue with you on this Ron. They aren't showing their work on QVF thrusters. Doom on them if they want to be taken seriously and much to my dismay  :(. Therefore I am looking for my own.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 06:09 pm
The QV thrust scenario is the only method available to justify measuring thrust from an otherwise sealed rf cavity and still say that momentum was conserved.
I'm sorry but that's not true.  M-E theory makes such an explanation and QVF model does not.  Sonny clearly owns that he is proposing a violation of conservation whereas M-E theory does not require this.

The point however in regards to M-E is that though the cavity is sealed, in M-E theory it is part of the larger system including all the mass in the universe.  You cannot talk about conservation in open systems and the M-E system is the universe under all circumstances.

Okay but I can tell you that there is a body of knowledge you are not taking into account. That is the difference between local and global symmetries.

Broken local symmetries must still satisfy global symmetries. This lecture breaks it down.

http://www.youtube.com/watch?v=j__HeM-9bq0

Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/03/2014 06:16 pm
......

Hi there.

I wouldn't put much stock in the ostensibly technical speculations that fill this thread. The results are certainly wrong and are in clear violations of macroscopic conservation of momentum. All explanations or "models" proposed to explain this (quantum plasma, virtual particles, etc.) are all based on incredibly bad physics.

Any signal these experimenters find is almost certainly due to a terrible experimental method and questionable data analysis.

As far as I can tell, along with the greater physics and engineering communities (from what I have seen), this is a fantasy device.
How many of the five competing models to explain thrust from these devices are you familiar with?  I happen to agree with you about QVF and virtual particles, but there are 5 models to choose from and that's one.

Here is his (Supergravity's) opinion on Woodward's theory:  http://forum.nasaspaceflight.com/index.php?topic=31037.msg1065368#msg1065368, which Supergravity has discussed at length in that thread dedicated to Woodward's thread.
Yes well, he's entirely wrong.  He's pretending to dispense with a theory that's been through 20 years of peer review, and that is gaining an ever increasing following amongst the physics community, by simply stating it is not consistent with GR when in fact it is required by GR.

I'll bet beers he hasn't read the book or the papers.  I would note too, the references are all of people doing this same thing--don't know the theory, haven't read the papers, making sweeping claims.

That's not science.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 06:18 pm
...

When the author writes << This situation can be different however in materials that are temporally and spatially asymmetric.>> the author is explicitly discussing material asymmetry, what is known scientifically as anisotropy or aelotropy: different material properties in different intrinsic (materially embedded) directions.  This should not be confused with asymmetrical geometry of an isotropic material. 

Moreover, the author requires a specific type of anisotropy: helical anisotropy, a type of anisotropy found in some (chiral) polymer chains, but unusual in a macro sample (typical fabrication methods like injection molding result in isotropic macro samples even when the polymer chains are chiral).

The materials used in the EM Drives (copper) and the polymer dielectrics (Teflon and Polyethylene) are isotropic homogeneous materials and hence do not satisfy the condition required by the author.

Well a quick fact check on what you are saying finds no mention of the word "helical" or "anisotrop" or "anisotropic' or "anisotropy" in either publication. So it sounds like that is your interpretation not the information reported.........am I sensing obstructionism?
The author uses the word chirality (instead of helical) and material asymmetry (instead of anisotropy), which is understandable in his context because he is dealing with chiral molecules in a micro context.  It is obvious that the author does not mean geometrical asymmetry of an isotropic material.
Quote
Concerning "am I sensing obstructionism?", I'm only writing this for those who may appreciate such a clarification.

Well I can prove to you that chirality is not the same as helicity. I'm going to draw some mustaches on electrons for you and break this down to parade rest. That will make things as right as rain. In short, helicity is spin in linear motion. Chirality is in motion and at rest. Spin at rest is uncertain.

http://www.quantumdiaries.org/2011/06/19/helicity-chirality-mass-and-the-higgs/

Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 06:21 pm
......

Hi there.

I wouldn't put much stock in the ostensibly technical speculations that fill this thread. The results are certainly wrong and are in clear violations of macroscopic conservation of momentum. All explanations or "models" proposed to explain this (quantum plasma, virtual particles, etc.) are all based on incredibly bad physics.

Any signal these experimenters find is almost certainly due to a terrible experimental method and questionable data analysis.

As far as I can tell, along with the greater physics and engineering communities (from what I have seen), this is a fantasy device.
How many of the five competing models to explain thrust from these devices are you familiar with?  I happen to agree with you about QVF and virtual particles, but there are 5 models to choose from and that's one.

Here is his (Supergravity's) opinion on Woodward's theory:  http://forum.nasaspaceflight.com/index.php?topic=31037.msg1065368#msg1065368, which Supergravity has discussed at length in that thread dedicated to Woodward's thread.
Yes well, he's entirely wrong.  He's pretending to dispense with a theory that's been through 20 years of peer review, and that is gaining an ever increasing following amongst the physics community, by simply stating it is not consistent with GR when in fact it is required by GR.

I'll bet beers he hasn't read the book or the papers.  I would note too, the references are all of people doing this same thing--don't know the theory, haven't read the papers, making sweeping claims.

That's not science.

Ron, I value your input. I must remind you to not fall in love with a theory. Fall in love with the truth. Are you trying to sell me a book or the truth?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/03/2014 06:25 pm
I wasn't even responding to you.  Do you have these suspicions often about people talking about you behind your back?  ;)
Title: Re: EM Drive Developments
Post by: Rodal on 11/03/2014 06:29 pm
I'm only writing this for those who may appreciate a clarification on Donaire's formulation ( http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf ).


Donaire explcitly requires a helical (chiral) anisotropic third order tensor (epsilon ijk) as shown in this attachment:

gamma is an antisymmetric T-P odd tensor resulting from the product of (helically anisotropic) epsilon ijk with the magnetic field B

(The word helical of course has multiple connotations, and this clarification only refers to how Donaire uses it)

helical:
(http://upload.wikimedia.org/wikipedia/commons/8/81/Circular.Polarization.Circularly.Polarized.Light_Right.Handed.Animation.305x190.255Colors.gif)


Now, my understanding is the following: if a polymer material has chiral molecule chains, if the chains are like a "spaghetti" in random directions as usual isotropic polymers are (for example as a result of injection molding) , the chiral effect will be nullified by the random orientation of the polymer chain spaghetti.

For the Donaire effect to be mutually self-reinforcing and not self-cancelling, one needs the overall material to have a helical anisotropy.

Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 06:46 pm
I wasn't even responding to you.  Do you have these suspicions often about people talking about you behind your back?  ;)

Um no, we've been here before. You refute every idea that isn't Woodward's. Then plug his book.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 06:54 pm
I'm only writing this for those who may appreciate a clarification on Donaire's formulation ( http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf ).


Donaire explcitly requires a helical (chiral) anisotropic third order tensor (epsilon ijk) as shown in this attachment:

gamma is an antisymmetric T-P odd tensor resulting from the anisotropic product of epsilon ijk with the magnetic field B

(The word helical of course has multiple connotations, and this clarification only refers to how Donaire uses it)

helical:
(http://upload.wikimedia.org/wikipedia/commons/8/81/Circular.Polarization.Circularly.Polarized.Light_Right.Handed.Animation.305x190.255Colors.gif)
The Oracle (gif above) points you in the right direction, but doesn't light the way........As I stated. Helicity and chirality are not the same thing. Please take the time to research it. As I have.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/03/2014 06:57 pm
I wasn't even responding to you.  Do you have these suspicions often about people talking about you behind your back?  ;)

Um no, we've been here before. You refute every idea that isn't Woodward's. Then plug his book.
I am most familiar with Woodward's work because I dispensed with all the competition almost 10 years ago for good reasons.  When someone makes a claim about Woodward or anyone else's work that I know is false, I simply post about it.  It was in the context of the discussion.  And I did not plug his book.

BTW, have you read it?   ;D
Title: Re: EM Drive Developments
Post by: RotoSequence on 11/03/2014 07:06 pm
I wasn't even responding to you.  Do you have these suspicions often about people talking about you behind your back?  ;)

Um no, we've been here before. You refute every idea that isn't Woodward's. Then plug his book.
I am most familiar with Woodward's work because I dispensed with all the competition almost 10 years ago for good reasons.  When someone makes a claim about Woodward or anyone else's work that I know is false, I simply post about it.  It was in the context of the discussion.  And I did not plug his book.

BTW, have you read it?   ;D

Why haven't you dispensed with Woodward's?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/03/2014 07:12 pm
I'm only writing this for those who may appreciate a clarification on Donaire's formulation ( http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf ).


Donaire explcitly requires a helical (chiral) anisotropic third order tensor (epsilon ijk) as shown in this attachment:

gamma is an antisymmetric T-P odd tensor resulting from the product of (helically anisotropic) epsilon ijk with the magnetic field B

(The word helical of course has multiple connotations, and this clarification only refers to how Donaire uses it)

helical:
(http://upload.wikimedia.org/wikipedia/commons/8/81/Circular.Polarization.Circularly.Polarized.Light_Right.Handed.Animation.305x190.255Colors.gif)


Now, my understanding is the following: if a polymer material has chiral molecule chains, if the chains are like a "spaghetti" in random directions as usual isotropic polymers are (for example as a result of injection molding) , the chiral effect will be nullified by the random orientation of the polymer chain spaghetti.

For the Donaire effect to be mutually self-reinforcing and not self-cancelling, one needs the overall material to have a helical anisotropy.


Nice! 

Spectral non-reciprocity is needed: Yes, that is the condition you will get from the "coffee can" resonator in an AFR.

From what I can gather reading the rest and trying to apply it to the cavity, it should be treated as a single quantum "oscillator" w/ the conduction electron bands providing the Doppler shift required.

Spectral non-reciprocity is as far as I've gotten on a GR basis.
Title: Re: EM Drive Developments
Post by: RotoSequence on 11/03/2014 07:17 pm
On a potentially relevant tangent, fermilab has figured out a new, less expensive way to generate high power, tightly controlled RF pulses, using a magnetron in a superconducting cavity.  http://www.fnal.gov/pub/today/archive/archive_2014/today14-11-03.html
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 07:28 pm
Moderators. Our discussions get intense at times, yet we remain respectful. Please bear with us. We're making progress. Extraordinary claims require extraordinary evidence. In the end, all of us here are after the same thing. A way forward.....to advance knowledge, thus humanity if anything comes of this. The only way forward is the truth. We each have our own ideas of what the truth is. The real truth is somewhere in the middle, past egos and pet ideas, somewhere in there is the way forward.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 07:30 pm
I'm only writing this for those who may appreciate a clarification on Donaire's formulation ( http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf ).


Donaire explcitly requires a helical (chiral) anisotropic third order tensor (epsilon ijk) as shown in this attachment:

gamma is an antisymmetric T-P odd tensor resulting from the product of (helically anisotropic) epsilon ijk with the magnetic field B

(The word helical of course has multiple connotations, and this clarification only refers to how Donaire uses it)

helical:
(http://upload.wikimedia.org/wikipedia/commons/8/81/Circular.Polarization.Circularly.Polarized.Light_Right.Handed.Animation.305x190.255Colors.gif)


Now, my understanding is the following: if a polymer material has chiral molecule chains, if the chains are like a "spaghetti" in random directions as usual isotropic polymers are (for example as a result of injection molding) , the chiral effect will be nullified by the random orientation of the polymer chain spaghetti.

For the Donaire effect to be mutually self-reinforcing and not self-cancelling, one needs the overall material to have a helical anisotropy.


Nice! 

Spectral non-reciprocity is needed: Yes, that is the condition you will get from the "coffee can" resonator in an AFR.

From what I can gather reading the rest and trying to apply it to the cavity, it should be treated as a single quantum "oscillator" w/ the conduction electron bands providing the Doppler shift required.

Spectral non-reciprocity is as far as I've gotten on a GR basis.

Can you break down what your interpretation of non-reciprocity means. Sounds like broken symmetry to me but I wasn't sure. I didn't quite get what they were meaning by that. Also what is an AFR? There is a lot in that presentation that I didn't quite understand.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/03/2014 07:36 pm
I'm only writing this for those who may appreciate a clarification on Donaire's formulation ( http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf ).


Donaire explcitly requires a helical (chiral) anisotropic third order tensor (epsilon ijk) as shown in this attachment:

gamma is an antisymmetric T-P odd tensor resulting from the product of (helically anisotropic) epsilon ijk with the magnetic field B

(The word helical of course has multiple connotations, and this clarification only refers to how Donaire uses it)

helical:
(http://upload.wikimedia.org/wikipedia/commons/8/81/Circular.Polarization.Circularly.Polarized.Light_Right.Handed.Animation.305x190.255Colors.gif)


Now, my understanding is the following: if a polymer material has chiral molecule chains, if the chains are like a "spaghetti" in random directions as usual isotropic polymers are (for example as a result of injection molding) , the chiral effect will be nullified by the random orientation of the polymer chain spaghetti.

For the Donaire effect to be mutually self-reinforcing and not self-cancelling, one needs the overall material to have a helical anisotropy.


Nice! 

Spectral non-reciprocity is needed: Yes, that is the condition you will get from the "coffee can" resonator in an AFR.

From what I can gather reading the rest and trying to apply it to the cavity, it should be treated as a single quantum "oscillator" w/ the conduction electron bands providing the Doppler shift required.

Spectral non-reciprocity is as far as I've gotten on a GR basis.

Can you break down what your interpretation of non-reciprocity means. Sounds like broken symmetry to me but I wasn't sure. I didn't quite get what they were meaning by that. Also what is an AFR? There is a lot in that presentation that I didn't quite understand.

no momentum transfer w/o a frequency change

Accelerating frame of reference
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/03/2014 07:37 pm
With respect guys.
Like my pc this thread needs to restart now
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 07:39 pm
I wasn't even responding to you.  Do you have these suspicions often about people talking about you behind your back?  ;)

Um no, we've been here before. You refute every idea that isn't Woodward's. Then plug his book.
I am most familiar with Woodward's work because I dispensed with all the competition almost 10 years ago for good reasons.  When someone makes a claim about Woodward or anyone else's work that I know is false, I simply post about it.  It was in the context of the discussion.  And I did not plug his book.

BTW, have you read it?   ;D

Woodward's work is very closely related with EMdrive (those with dielectrics inserted). The theory presented by the original inventors describing the effects diverge. They are cousins. The same kind of relation as with jet engines and rockets. Similar but not the same.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 07:44 pm
With respect guys.
Like my pc this thread needs to restart now

Good idea. As it takes me 10 times to read a paper before I finally get it.....Time to start over.

I just got word that NASA has tested an RF test article that seems to exhibit an "anomalous thrust."

http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

Now this is interesting stuff!

Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/03/2014 07:46 pm
Wow! New thread needed...
Title: Re: EM Drive Developments
Post by: Mulletron on 11/03/2014 07:59 pm
I'm only writing this for those who may appreciate a clarification on Donaire's formulation ( http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf ).


Donaire explcitly requires a helical (chiral) anisotropic third order tensor (epsilon ijk) as shown in this attachment:

gamma is an antisymmetric T-P odd tensor resulting from the product of (helically anisotropic) epsilon ijk with the magnetic field B

(The word helical of course has multiple connotations, and this clarification only refers to how Donaire uses it)

helical:
(http://upload.wikimedia.org/wikipedia/commons/8/81/Circular.Polarization.Circularly.Polarized.Light_Right.Handed.Animation.305x190.255Colors.gif)


Now, my understanding is the following: if a polymer material has chiral molecule chains, if the chains are like a "spaghetti" in random directions as usual isotropic polymers are (for example as a result of injection molding) , the chiral effect will be nullified by the random orientation of the polymer chain spaghetti.

For the Donaire effect to be mutually self-reinforcing and not self-cancelling, one needs the overall material to have a helical anisotropy.


Nice! 

Spectral non-reciprocity is needed: Yes, that is the condition you will get from the "coffee can" resonator in an AFR.

From what I can gather reading the rest and trying to apply it to the cavity, it should be treated as a single quantum "oscillator" w/ the conduction electron bands providing the Doppler shift required.

Spectral non-reciprocity is as far as I've gotten on a GR basis.

Can you break down what your interpretation of non-reciprocity means. Sounds like broken symmetry to me but I wasn't sure. I didn't quite get what they were meaning by that. Also what is an AFR? There is a lot in that presentation that I didn't quite understand.

no momentum transfer w/o a frequency change

Accelerating frame of reference

Want to throw any more details at that? I need help. I am not a smart man......(from Dumb and Dumber and Forrest Gump). My knowledge of the term reciprocity is, "If you obey my rules, I'll obey your rules."
Title: Re: EM Drive Developments
Post by: aero on 11/03/2014 08:01 pm
You know, that looks an awfully lot like orbital angular momentum.

http://www.researchgate.net/publication/29814160_Light_with_a_twist_in_its_tail (http://www.researchgate.net/publication/29814160_Light_with_a_twist_in_its_tail)
Title: Re: EM Drive Developments
Post by: aero on 11/03/2014 08:19 pm
You know, that looks an awfully lot like orbital angular momentum.



That long URL is breaking the formatting.

Please replace with this short URL

http://goo.gl/WCzDMw

for the same item

Thanks

Like that?
Title: Re: EM Drive Developments
Post by: Rodal on 11/03/2014 09:12 pm
I'm only writing this for those who may appreciate a clarification on Donaire's formulation ( http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf ).


Donaire explcitly requires a helical (chiral) anisotropic third order tensor (epsilon ijk) as shown in this attachment:

gamma is an antisymmetric T-P odd tensor resulting from the product of (helically anisotropic) epsilon ijk with the magnetic field B

(The word helical of course has multiple connotations, and this clarification only refers to how Donaire uses it)

helical:
(http://upload.wikimedia.org/wikipedia/commons/8/81/Circular.Polarization.Circularly.Polarized.Light_Right.Handed.Animation.305x190.255Colors.gif)


Now, my understanding is the following: if a polymer material has chiral molecule chains, if the chains are like a "spaghetti" in random directions as usual isotropic polymers are (for example as a result of injection molding) , the chiral effect will be nullified by the random orientation of the polymer chain spaghetti.

For the Donaire effect to be mutually self-reinforcing and not self-cancelling, one needs the overall material to have a helical anisotropy.


Yes a polarized lens is a good analogy for illustration of a commonly known effect [although like every analogy never a substitute for the real thing] why the material needs to be polarized throughout to be effective.  A polarized material is anisotropic: it has different properties along different material axes. It has the long-chain molecules aligned in the same direction (perpendicular to the polarization axis).  During manufacture the long-chain molecules are stretched to align them in a particular direction, this direction is perpendicular to the polarization axis. The electromagnetic vibrations parallel to the alignment of the long-chain molecules are absorbed. Only EM vibrations perpendicular to the  the alignment of the long-chain molecules pass through.

We all know we cannot use a copper metal as a Polaroid lens, neither can we use an isotropic sheet of Teflon or Polyethylene as a Polaroid lens.  And not every polymer lens is a polarized lens: to achieve polarization one has to have a suitable material that can be polarized and then utilize a suitable means of manufacture that will achieve the polarization.

One needs to have the whole polymer lens oriented along the same axis to achieve polarization.  Similarly with the proposed chirality of Donaire: the whole dielectric material would have to have chirality oriented in the same direction,and to achieve this, one has to use a suitable means of manufacture (not just injection molding into a mold).  Using a material with chiral polymer chains that are (as usual in polymers) like a random spaghetti, would be like having a lens with the chains oriented in random orientations: it could not work as intended, and neither can the randomly oriented chiral material.
Title: Re: EM Drive Developments
Post by: Rodal on 11/03/2014 11:16 pm
Next batch of scraped data from figure 19 page 15 of "anomalous thrust..." from Brady et al (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf). The top (result1.txt) and middle (result2.txt) graphs are scraped.

Same caveats as previously posted (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281007#msg1281007). For first curve (top figure 19) I removed the (non existent) flat last sampled data of the previous version to avoid artefacts when analysing with filters.

Each line of those files is the value in µN at each .1 s interval (linearly interpolated from manual reconstruction). The vertical scale were roughly given by the calibration pulses at about 30µN (expect no more than 5% precision). Absolute values are arbitrary (because of the drifting baseline). Horizontal scale given by the indication of 196 s for the whole display graph window of the pictures.

Will proceed with other graphs when time permits. Will post attempts at original signal reconstruction : thrust(t) while what we see is only balance displacement(t). Since the balance is underdamped, a lot can hide behind those oscillations and drifts in position.

Frobnicated Top of Fig. 19 page 15 of anomalous (Mean and Linear Least Squares Fit)


Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue)

Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Linear LS (Red)


Power Spectral Density (from FFT)  on raw data detrended by Linear LS (Red)

horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*94.6

Peaks         Period (seconds)
3                 1/(3/(94.6))  = 31.53 s   Pulse period
5                 1/(5/(94.6))  = 18.92 s   4*Pendulum Period
7                 1/(7/(94.6))  = 13.51 s
10               1/(10/(94.6))  = 9.46 s   2*Pendulum Period
15               1/(15/(94.6))  = 6.31 s   <---- This unidentified frequency appears strongly on both Top and Middle
18               1/(18/(94.6))  = 5.26 s
20               1/(20/(94.6))  = 4.73 s    Pendulum Period
25               1/(25/(94.6))  = 3.78 s
41               1/(41/(94.6))  = 2.31 s    1/2 Pendulum Period
Title: Re: EM Drive Developments
Post by: aero on 11/03/2014 11:35 pm
I had the thought a long time ago that the measured thrust might have to do with photon angular momentum. That's why I knew where to find the paper I linked above.

It occurs to me now that this phenomenon might hint at an explanation of the difference in thrust between Brady a" and Brady b" which  differ in measured force, but otherwise very little.
Title: Re: EM Drive Developments
Post by: Rodal on 11/03/2014 11:53 pm
Well Brady "A" and Brady "B" truncated cone results can be explained by drifting frequency away from amplitude due to the extremely small bandwidth associated with high Q and their lack of suitable equipment as proposed by R. Ludwick
Title: Re: EM Drive Developments
Post by: aero on 11/04/2014 05:01 am
Well Brady "A" and Brady "B" truncated cone results can be explained by drifting frequency away from amplitude due to the extremely small bandwidth associated with high Q and their lack of suitable equipment as proposed by R. Ludwick

That means, then that the outlier Bradly b" relative to Bradly a" is explained by equipment limitations. That explains the relationship, one relative to the other but does not address the fundamental forces. Still, it does rule out drawing conclusions relying on that difference because there is no substantive information contained within that difference.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 08:03 am
I had the thought a long time ago that the measured thrust might have to do with photon angular momentum. That's why I knew where to find the paper I linked above.

It occurs to me now that this phenomenon might hint at an explanation of the difference in thrust between Brady a" and Brady b" which  differ in measured force, but otherwise very little.

I think you are on the right track on this.  :) Photon angular momentum (circular polarization/helicity) is the first half of the puzzle and chirality and asymmetry of the dielectric is the second half of of the puzzle.

I know nature works this way, as it is fact that the weak interaction prefers left handed electrons.

So if we want to transfer momentum to/from the QV, we have to get the local rotations and asymmetries right.

The reason "from" is bold above is because given the literature I've been reading and have posted in this forum, it seems like we're not "thrusting against the qv" rather we're allowing the QV to push against us asymmetrically. Instead of the usual push from all directions equally. Read this as vacuum polarization in the presence of a material with asymmetric space and time via molecular chirality, and asymmetric radiation pressure acting on those molecules inside the cavity. This would be a good thing if true, because the QV is a source of infinite energy momentum. ;)

I have no idea if the RF inside the cavity at Nasa was RHCP or LHCP but they didn't say they ran their RF through a polarizer, and the rf probe used was a loop not a helix, so I suspect it was not circularly polarized. Maybe it should be.

Looks like it was most likely linear polarization since they used a loop probe inside the cavity and rotating the loop changes whether E or H is transverse.
Given that the cavity was conical though, an angular component could develop unintentionally through Coriolis effects or gyroscopic precession or Faraday rotation.

Also the fields themselves are in rotation by the right hand rule.

All this mentioned above and in previous posts (cited from many other's work) could allow EMdrive to "work" without breaking any Laws. What the world needs is a theory of EMdrive that doesn't get laughed at by the mainstream scientific community. It just takes a mathematically inclined person to formalize it and take their place in history. (If it works) Hint  ;)


This is why I've been boning up on my knowledge of spin/helicity/chirality.
Massive particles behave very differently than mass less particles wrt helicity. Local and global symmetries are different beasts too.

http://physics.unl.edu/~tgay/content/CPE.html
http://www.quantumdiaries.org/2011/06/19/helicity-chirality-mass-and-the-higgs/
Title: Re: EM Drive Developments
Post by: Rodal on 11/04/2014 01:08 pm
Next batch of scraped data from figure 19 page 15 of "anomalous thrust..." from Brady et al (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf). The top (result1.txt) and middle (result2.txt) graphs are scraped.

Same caveats as previously posted (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281007#msg1281007). For first curve (top figure 19) I removed the (non existent) flat last sampled data of the previous version to avoid artefacts when analysing with filters.

Each line of those files is the value in µN at each .1 s interval (linearly interpolated from manual reconstruction). The vertical scale were roughly given by the calibration pulses at about 30µN (expect no more than 5% precision). Absolute values are arbitrary (because of the drifting baseline). Horizontal scale given by the indication of 196 s for the whole display graph window of the pictures.

Will proceed with other graphs when time permits. Will post attempts at original signal reconstruction : thrust(t) while what we see is only balance displacement(t). Since the balance is underdamped, a lot can hide behind those oscillations and drifts in position.

Frobnicated Top of Fig. 19 page 15 of anomalous (Mean and Linear Least Squares Fit)


Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue)

Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Linear LS (Red)


Power Spectral Density (from FFT)  on raw data detrended by Linear LS (Red)

horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*94.6

Peaks         Period (seconds)
3                 1/(3/(94.6))  = 31.53 s   Pulse period
5                 1/(5/(94.6))  = 18.92 s   4*Pendulum Period
7                 1/(7/(94.6))  = 13.51 s
10               1/(10/(94.6))  = 9.46 s   2*Pendulum Period
15               1/(15/(94.6))  = 6.31 s <---- This unidentified frequency appears on both Top and Middle
18               1/(18/(94.6))  = 5.26 s
20               1/(20/(94.6))  = 4.73 s    Pendulum Period
25               1/(25/(94.6))  = 3.78 s
41               1/(41/(94.6))  = 2.31 s    1/2 Pendulum Period

Frobnicated Middle of Fig. 19 page 15 of anomalous NASA report (Mean, Linear Least Squares Fit and Quadratic Least Squares Fit)


Autocorrelation of Middle of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue), by Linear LS (Red) and by Quadratic LS (Green)


Power Spectral Density of Middle of Fig. 19 page 15  (from FFT) on raw data detrended by Quadratic LS (Red)

horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*98

Peaks         Period (seconds)
3                 1/(3/(98))  =  32.67 s   Pulse period
5                 1/(5/(98))  =  19.60 s   4*Pendulum Period
7                 1/(7/(98))  =  14..00 s
12               1/(13/(98))  =  7.54 s 
16               1/(16/(98))  =  6.13 s  <---- This unidentified frequency appears strongly on both Top and Middle
22               1/(22/(98))  =  4.45 s   Pendulum Period
29               1/(29/(98))  =  3.38 s   
34               1/(34/(98))  =  2.88 s
36               1/(36/(98))  =  2.72 s   
40               1/(40/(98))  =  2.45 s   
42               1/(42/(98))  =  2.33 s    1/2 Pendulum Period

Title: Re: EM Drive Developments
Post by: Rodal on 11/04/2014 02:09 pm
... the QV is a source of infinite energy. ....

The Quantum Vacuum is by definition the lowest state of energy and cannot be a source of infinite energy.  The idea that one can get infinite energy from the quantum vacuum rests on the singularities of quantum electrodynamics (before renormalization).  No leading university or leading research institution has people believing that the Quantum Vacuum is a source of infinite energy. One has to distinguish between the singularities in mathematical models from physical reality.  In classical mechanics there are also all kinds of singularities, that are recognized as non-physical.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 02:10 pm
Well as I stated on page 136

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269767#msg1269767

I'm personally putting MiHsC back on the shelf for application to EMdrive. I still have confidence in it and hope it is the right answer, but I don't think it applies to this situation. I had a lot of cognitive dissonance over MiHsC but I realize that I really don't need it in light of more elegant solutions which require less pushing the I believe button and messing with constants.

MiHsC is very very closely related to all this but the way it has been applied is backwards in my view.

I'm going to clean up the summary I keep on page 127 given the new info I have digested.

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269024#msg1269024

I guess my next step is get more familiar with the math of quantum mechanics. That is going to be rough because I'm trained in the math of electrical/electronic engineering.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 02:14 pm
... the QV is a source of infinite energy. ....

The Quantum Vacuum is by definition the lowest state of energy and cannot be a source of infinite energy.  The idea that one can get infinite energy from the quantum vacuum rests on the singularities of quantum electrodynamics (before renormalization).  No leading university or leading research institution has people believing that the Quantum Vacuum is a source of infinite energy. One has to distinguish between the singularities in mathematical models from physical reality.  In classical mechanics there are also all kinds of singularities, that are recognized as non-physical.

The only thing that takes away a perfect infinity is the cutoff at the Planck length. That takes away ridiculously small wavelengths. That is the lower bound. The upper bound is ridiculously long wavelengths. In between is a practically infinite amount of available wavelengths available. It is infinite otherwise. Not able to be exhausted.
Title: Re: EM Drive Developments
Post by: momerathe on 11/04/2014 03:14 pm
... the QV is a source of infinite energy. ....

The Quantum Vacuum is by definition the lowest state of energy and cannot be a source of infinite energy.  The idea that one can get infinite energy from the quantum vacuum rests on the singularities of quantum electrodynamics (before renormalization).  No leading university or leading research institution has people believing that the Quantum Vacuum is a source of infinite energy. One has to distinguish between the singularities in mathematical models from physical reality.  In classical mechanics there are also all kinds of singularities, that are recognized as non-physical.

The only thing that takes away a perfect infinity is the cutoff at the Planck length. That takes away ridiculously small wavelengths. That is the lower bound. The upper bound is ridiculously long wavelengths. In between is a practically infinite amount of available wavelengths available. It is infinite otherwise. Not able to be exhausted.

I think you're missing his point. It's the *lowest* state of energy. For practical purposes it doesn't matter what that energy density is because you can't access any of it; to do so you would need a lower energy state to transition to and this lower energy state doesn't, by definition, exist.

if you're interested in learning more about quantum mechanics, I recommend this series of lectures by Leonard Susskind: http://theoreticalminimum.com/courses .
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/04/2014 03:20 pm
"Spectral non-reciprocity" in the "coffee can" half-wave resonator at the earths surface.

df = (1.65 * 10^-8)Hz,  interestingly independent of frequency for a wavelength dependent resonator.

Doppler speed at 1GHz comes out at 5nm/sec.

Pretty small numbers.  Curious !
Title: Re: EM Drive Developments
Post by: aero on 11/04/2014 03:28 pm
... the QV is a source of infinite energy. ....

The Quantum Vacuum is by definition the lowest state of energy and cannot be a source of infinite energy.  The idea that one can get infinite energy from the quantum vacuum rests on the singularities of quantum electrodynamics (before renormalization).  No leading university or leading research institution has people believing that the Quantum Vacuum is a source of infinite energy. One has to distinguish between the singularities in mathematical models from physical reality.  In classical mechanics there are also all kinds of singularities, that are recognized as non-physical.

The only thing that takes away a perfect infinity is the cutoff at the Planck length. That takes away ridiculously small wavelengths. That is the lower bound. The upper bound is ridiculously long wavelengths. In between is a practically infinite amount of available wavelengths available. It is infinite otherwise. Not able to be exhausted.

Where does your idea of force due to evanescent coupling with the chamber stand? I have found some information quantifying such force mathematically. The information I have found is just a start though as the geometry is quite different than that of the cavity within the vacuum chamber.

I note that another name for evanescent is "near field." The two are almost, if not completely identical but described using different terminology.

So, did you rule out evanescent coupling as a source of the measured force?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 03:47 pm
... the QV is a source of infinite energy. ....

The Quantum Vacuum is by definition the lowest state of energy and cannot be a source of infinite energy.  The idea that one can get infinite energy from the quantum vacuum rests on the singularities of quantum electrodynamics (before renormalization).  No leading university or leading research institution has people believing that the Quantum Vacuum is a source of infinite energy. One has to distinguish between the singularities in mathematical models from physical reality.  In classical mechanics there are also all kinds of singularities, that are recognized as non-physical.

The only thing that takes away a perfect infinity is the cutoff at the Planck length. That takes away ridiculously small wavelengths. That is the lower bound. The upper bound is ridiculously long wavelengths. In between is a practically infinite amount of available wavelengths available. It is infinite otherwise. Not able to be exhausted.

Where does your idea of force due to evanescent coupling with the chamber stand? I have found some information quantifying such force mathematically. The information I have found is just a start though as the geometry is quite different than that of the cavity within the vacuum chamber.

I note that another name for evanescent is "near field." The two are almost, if not completely identical but described using different terminology.

So, did you rule out evanescent coupling as a source of the measured force?

I abandoned it because I couldn't find enough information to prove anything. It remains on the possible but not plausible shelf as another artifact effect. I didn't rule it out or in. What do you have?
Title: Re: EM Drive Developments
Post by: JasonAW3 on 11/04/2014 03:51 pm
Ok,

     Admittedly, the math for this a\has finally gotten WAY beyond me.

     Could someone give me an idea of the power to motion ratio that seems to be being generated with this system, verses, say, a regular chemical rocket?

     What I am trying to find out is simple; Is this system somehow generating more motion than should be possible, assuming a direct conversion of energy to motion?

     In other words, is 1 calorie of energy somehow rasing 1 cubic centimeter of water's temprature higher than 1 degree celcius, or is the amount of power being used within a reasonable ratio of energy effecient conversion, say, 70% of power applied is being converted to motion, as an example?

     For the moment, set aside HOW it appears to be doing what it is doing, and let's see if it violates any of the Laws of Thermodynamics.

     Sorry, but you guys have gone so far beyond me mathematically, (plus, I think I may have missed a couple of equations that would have made it simpler to follow) that I am having the devil's own time trying to keep up with this thread.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 03:58 pm
... the QV is a source of infinite energy. ....

The Quantum Vacuum is by definition the lowest state of energy and cannot be a source of infinite energy.  The idea that one can get infinite energy from the quantum vacuum rests on the singularities of quantum electrodynamics (before renormalization).  No leading university or leading research institution has people believing that the Quantum Vacuum is a source of infinite energy. One has to distinguish between the singularities in mathematical models from physical reality.  In classical mechanics there are also all kinds of singularities, that are recognized as non-physical.

The only thing that takes away a perfect infinity is the cutoff at the Planck length. That takes away ridiculously small wavelengths. That is the lower bound. The upper bound is ridiculously long wavelengths. In between is a practically infinite amount of available wavelengths available. It is infinite otherwise. Not able to be exhausted.

I think you're missing his point. It's the *lowest* state of energy. For practical purposes it doesn't matter what that energy density is because you can't access any of it; to do so you would need a lower energy state to transition to and this lower energy state doesn't, by definition, exist.

if you're interested in learning more about quantum mechanics, I recommend this series of lectures by Leonard Susskind: http://theoreticalminimum.com/courses .

I want to be clear that I'm not screaming "over unity" here. I'm not tapping into the ZPE here trying to get free energy. Just because there is an infinite reservoir available of something, that doesn't mean it is all available for use. In the application described by me, you must put in energy to get thrust. So there is no free lunch. You don't get back any more than you put in. The energy of the QV is infinite in the sense that it is available everywhere to push on you.

There is no debate whether the QV influences our physical world.

The debate is whether it can be used for anything useful, like push on you in a particular direction, instead of all directions. The papers on Casimir momentum linked to previously, seem to suggest this is possible.

Right now it is a mathematical annoyance that must me corrected for.

Now to the math, I've seen calculations of velocity contributions to dielectrics as low as 50nm/s. As long as they are non zero, that's pretty good, for a start.

More info on the Feigel Effect:

http://rspa.royalsocietypublishing.org/content/early/2011/10/06/rspa.2011.0481.full.pdf (A peer review with surprising results!)

http://physics.aps.org/story/v13/st3

The anomalous thrust production from an RF test device was due to the Feigel–van Tiggelen effect.
Title: Re: EM Drive Developments
Post by: aero on 11/04/2014 06:15 pm
This is an estimate of the relative geometry between the Chamber walls and the cavity. These dimensions are needed in order to calculate  evanescent  forces.

First, by looking at the photograph, it appears as though the method of reversing the direction of the cavity must be simply to withdraw the complete test stand from the chamber, with cavity mounted, reverse the test stand front to back and re-insert it into the chamber. Note that reversing direction this way will not change the relative chamber wall/cavity geometry. That is, the base (large end) will be the same distance from the wall, as will the small end, just the opposite chamber walls.

What the above means is that any electromagnetic interactions between the cavity and chamber will not be changed by reversing the cavity, so that interacting forces need only be calculated for one orientation. They will be the same for either orientation.

To make this easy, I make an assumption which can be corrected in the end. That is, assume that the bottom corner of the cavity conic section and the large end sits on the chamber central axis - that is the 0,0 origin. Using dimensions of the cavity previously extracted:

surface      cm    inch
Large dia. 27.25   10.73
Small dia. 15.36   6.05
Length     24.48   9.64

and the given diameter of the Chamber, 30 inches (76.2 cm), radius = 15 inches (38.1 cm) I calculate that the diagonal of the cavity is 12.77 inches or 2.23 inches less than the chamber radius. That gives the location of the top of the small dia. WRT the chamber wall. (Note that the cavity diagonal makes an angle of 0.716 rad. from horizontal. Also, the top of the large end is 4.3 inches from the top center of the chamber and the lower corner of the small end is 5.08 inches from the wall in the chamber radial direction. Summarizing:

Chamber diameter/radius           30 / 15 inches      (76.2 /  38.1 cm)   
Small end to chamber wall range - 2.33 to 5.08 inches (5.66 to 12.91 cm).
Large end to chamber wall range - 4.3  to 15.0 inches (10.92 to 38.1 cm).

These estimates can be adjusted by moving the origin up and over. How much is just a guess, maybe one inch up and 1/2 inch to the left. Making that adjustment would bring the small end closer to the wall.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 06:20 pm
Your numbers are pretty close to mine too. Looks good!

My cad files and other screeshots:
https://drive.google.com/folderview?id=0B4PCfHCM1KYoNmtVVDZuZ1FrQ2M&usp=sharing&tid=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM
Title: Re: EM Drive Developments
Post by: aero on 11/04/2014 06:42 pm
Thanks. But we need to explain this video before we can attribute the EM Drive thrust in general to chamber wall/cavity interactions.

http://emdrive.com/dynamictests.html (http://emdrive.com/dynamictests.html)


Video clips are near the bottom of the page. I don't see anything in the video that the EM Drive could interact with.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 06:50 pm
Thanks. But we need to explain this video before we can attribute the EM Drive thrust in general to chamber wall/cavity interactions.

http://emdrive.com/dynamictests.html (http://emdrive.com/dynamictests.html)


Video clips are near the bottom of the page. I don't see anything in the video that the EM Drive could interact with.

I was using evanescent coupling as another artifact (didn't start off that way, in the beginning I was trying to use it to explain legit thrust) to throw in there with heat and all the other possible experimental artifacts. Your take on the video is interesting and that does seem to further kill evanescent wave coupling as a possibility. Nice job indeed. I posted that video a few pages back trying to demonstrate conservation of angular momentum. http://forum.nasaspaceflight.com/index.php?topic=29276.msg1280373#msg1280373

I've been back and forth on whether EMdrive is bs or not over the past few weeks.

I've come to the conclusion that empty copper can EMdrives are bs, those with dielectrics inserted are legit.

Oh yeah.... Air is a dielectric too. This means that with the Feigel–van Tiggelen effect, EVERYBODY wins!
Title: Re: EM Drive Developments
Post by: birchoff on 11/04/2014 07:25 pm

I'm not seeing it that way. A Hall thruster is not propellant less. He never used the word propellant less to describe the paradox. I see a false paradox, which was created by bad methodology and bad math.

Advanced propulsion does not equal propellant less propulsion.

"One of the issues to consider for a constant thrust system is the matter of conservation of energy."
You can't have constant thrust with action/reaction scheme, because there can be a constant expelled mass flow for only so long. So for me this is broadly "we are talking about propellantless propulsion". And indeed any such propellantless scheme has an issue of energy conservation. In the terminology of this appendix, the Hall thruster is conventional, the EMdrive (propellantless whatever) is advanced.

I see another spectacularly failed attempt at addressing the intrinsic issue with energy conservation of propellantless schemes, as bad as Shawyer's. Any serious physicist/engineer reading this appendix A will immediately see the plain absurdity of the argument, one way or another. This is not serious.

What is most perplexing is that this report follows the "Anomalous..." Brady experiment report.
...

Not sure If this is an accurate representation. If you check out this link http://ntrs.nasa.gov/search.jsp?R=20140013174 (http://ntrs.nasa.gov/search.jsp?R=20140013174) you will see that the publication date is in January 2014 before the paper was presented at AIAA. Actually if you compare the metadata to the Anomalus thrust paper presented at AIAA this year, see here http://ntrs.nasa.gov/search.jsp?R=20140006052 (http://ntrs.nasa.gov/search.jsp?R=20140006052). I would interpret the following.

Since, Human Outer Solar System Exploration via Q-Thruster Technology(Paper 2) references
Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum
(Paper 1) then Paper 1 was written before Paper 2. However, paper 2 was written before Paper 1 was widely circulated. Therefore, I can see how any questions raised about the results described in Paper 1 would not be answered in Paper 2. That doesn't mean that there aren't people in the Eagleworks circle who could have asked the same questions we are currently asking. However, they could also be privy to the missing information that is directly leading us to ask these questions. So they may already know the answers or haven't thought to ask those questions because of some sort of bias preventing their thought processes from thinking of these questions.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 07:30 pm
Well the photo above (scroll up) was taken 23Jan14.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/04/2014 07:32 pm
Turns out to have been a blissfull few days... Saturday thru mid-day today with out fone or intertubes.  Came back to this thread as a junkie.

Ron, I value your input. I must remind you to not fall in love with a theory. Fall in love with the truth. Are you trying to sell me a book or the truth?

I wasn't even responding to you.  Do you have these suspicions often about people talking about you behind your back?  ;)

Ahhhh, Ron:  Stick with English meanings.  Everybody is responding to everybody on the thread.  Take it to PM if you want, expect, or demand privacy.

Mulletron has no suspicions, and asks of you a simple, reasonable request.  Take it or leave it.

Can you break down what your interpretation of non-reciprocity means.

Easy.  You scratch my back, and I keep on moving, withoug even a thank you.

Seriously, you all have lost me over the last twenty pages...

Now this is interesting stuff!

Is this the same thingy without the copper can?  This image would be easier to dimension.  Also, since you can see the FZTK stuff unencombered, you could estimate the standard lengts of the available stock.

Any "you" that wants to, that is.
Title: Re: EM Drive Developments
Post by: tchernik on 11/04/2014 07:52 pm
Thanks. But we need to explain this video before we can attribute the EM Drive thrust in general to chamber wall/cavity interactions.

http://emdrive.com/dynamictests.html (http://emdrive.com/dynamictests.html)


Video clips are near the bottom of the page. I don't see anything in the video that the EM Drive could interact with.

After all this lengthy discussion I have been tracking for a while, what stays with me is the absolute need of more experimental results to talk about. More data points, more confirmations (or refutations).

And the video you bring, while enticing, is alas not enough. I can imagine several ways to trick a video like that, just requiring enough willingness and lack of a consciousness to do it.

Don't get me wrong. I like visual demonstrations as the next guy, it's that we only have this one so far.

But if more people replicated that... we could start becoming really intrigued.
Title: Re: EM Drive Developments
Post by: momerathe on 11/04/2014 08:27 pm
I want to be clear that I'm not screaming "over unity" here. I'm not tapping into the ZPE here trying to get free energy. Just because there is an infinite reservoir available of something, that doesn't mean it is all available for use. In the application described by me, you must put in energy to get thrust. So there is no free lunch. You don't get back any more than you put in. The energy of the QV is infinite in the sense that it is available everywhere to push on you.

That's.. not what energy means. What you describe appears to be closer to the idea that QV is/could be an infinite momentum sink. This is, basically, the fundamental question behind these devices.

Quote
The debate is whether it can be used for anything useful, like push on you in a particular direction, instead of all directions. The papers on Casimir momentum linked to previously, seem to suggest this is possible.

That's pretty uncontroversial on its own. The Unruh effect can create radiation, and thus momentum, and thus thrust. The thing is that it's creating real particles, the momentum isn't disapearing into the quantum vacuum, as I've seen some proponents of the QVPT suggest. (I'm not saying you're one of them, BTW, I haven't the mental fortitude to follow this thread in detail.)

However, creating particles from vacuum takes energy, and you just end up with a complicated photon rocket.


Quote
More info on the Feigel Effect:

http://rspa.royalsocietypublishing.org/content/early/2011/10/06/rspa.2011.0481.full.pdf (A peer review with surprising results!)

http://physics.aps.org/story/v13/st3

The anomalous thrust production from an RF test device was due to the Feigel–van Tiggelen effect.

Interesting paper. Some thoughts occur:
* the dielectric constant in the can will be very low. it's meant to be evacuated, after all.
* the ExB fields in the Feigel effect are steady, those in an EM wave oscillate sinusoidally. Thus the force would be continually swapping direction, and average to zero.
* If you are right, it spells the death-knell for this device as a form of propulsion. From the paper:

Quote
Feigel considers the following situation: a region of a dielectric fluid far from
the boundaries of its container is initially at rest (t = 0). Subsequently, strong
electrical and magnetic fields crossed at right angles to each other are applied
to the region. As the fields reach their constant final values, Eext and Bext for
electrical and magnetic fields, respectively, the fluid is accelerated by the Lorentz
forces (FLorentz ∝ vt(Eext × Bext)) to a final velocity v.

It's a one-off impulse. It can't provide a steady thrust (again, I'm not saying that you're one of the people saying it does) unless you can keep increasing the field forever. When you turn the field off, the dielectric will stop moving. Kind of how the casimir effect provides a one-off energy gain when you bring the two plates together.
Title: Re: EM Drive Developments
Post by: aero on 11/04/2014 08:28 pm
Thanks. But we need to explain this video before we can attribute the EM Drive thrust in general to chamber wall/cavity interactions.

http://emdrive.com/dynamictests.html (http://emdrive.com/dynamictests.html)


Video clips are near the bottom of the page. I don't see anything in the video that the EM Drive could interact with.

After all this lengthy discussion I have been tracking for a while, what stays with me is the absolute need of more experimental results to talk about. More data points, more confirmations (or refutations).

And the video you bring, while enticing, is alas not enough. I can imagine several ways to trick a video like that, just requiring enough willingness and lack of a consciousness to do it.

Don't get me wrong. I like visual demonstrations as the next guy, it's that we only have this one so far.

But if more people replicated that... we could start becoming really intrigued.

No question that we need more data and more replication.

Operating on the assumption that there is a real force generated by the EM Drive precludes the need to speculate that the data is somehow faked. If we assume that the data is faked and the force is not real then that's the end of the story. No need to go any further.

We here are operating on the assumption that the measurements are real and that the force is from a real EM Drive effect or else it is from an experimental artifact. We are pursuing both lines of investigation so the story ends when we find either the cause of the EM Drive effect or the experimental artifact that fits all of the data we have.  Or when we have exhausted the data available. Without more data the latter seems likely at this point.
Title: Re: EM Drive Developments
Post by: Rodal on 11/04/2014 08:31 pm
Next batch of scraped data from figure 19 page 15 of "anomalous thrust..." from Brady et al (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf). The top (result1.txt) and middle (result2.txt) graphs are scraped.

Same caveats as previously posted (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281007#msg1281007). For first curve (top figure 19) I removed the (non existent) flat last sampled data of the previous version to avoid artefacts when analysing with filters.

Each line of those files is the value in µN at each .1 s interval (linearly interpolated from manual reconstruction). The vertical scale were roughly given by the calibration pulses at about 30µN (expect no more than 5% precision). Absolute values are arbitrary (because of the drifting baseline). Horizontal scale given by the indication of 196 s for the whole display graph window of the pictures.

Will proceed with other graphs when time permits. Will post attempts at original signal reconstruction : thrust(t) while what we see is only balance displacement(t). Since the balance is underdamped, a lot can hide behind those oscillations and drifts in position.

Frobnicated Top of Fig. 19 page 15 of anomalous (Mean and Linear Least Squares Fit)


Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue)

Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Linear LS (Red)


Power Spectral Density (from FFT)  on raw data detrended by Linear LS (Red)

horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*94.6

Peaks         Period (seconds)
3                 1/(3/(94.6))  = 31.53 s   Pulse period
5                 1/(5/(94.6))  = 18.92 s   4*Pendulum Period
7                 1/(7/(94.6))  = 13.51 s
10               1/(10/(94.6))  = 9.46 s   2*Pendulum Period
15               1/(15/(94.6))  = 6.31 s <---- This unidentified frequency appears on both Top and Middle
18               1/(18/(94.6))  = 5.26 s
20               1/(20/(94.6))  = 4.73 s    Pendulum Period
25               1/(25/(94.6))  = 3.78 s
41               1/(41/(94.6))  = 2.31 s    1/2 Pendulum Period

Frobnicated Middle of Fig. 19 page 15 of anomalous NASA report (Mean, Linear Least Squares Fit and Quadratic Least Squares Fit)


Autocorrelation of Middle of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue), by Linear LS (Red) and by Quadratic LS (Green)


Power Spectral Density of Middle of Fig. 19 page 15  (from FFT) on raw data detrended by Quadratic LS (Red)

horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*98

Peaks         Period (seconds)
3                 1/(3/(98))  =  32.67 s   Pulse period
5                 1/(5/(98))  =  19.60 s   4*Pendulum Period
7                 1/(7/(98))  =  14..00 s
12               1/(13/(98))  =  7.54 s 
16               1/(16/(98))  =  6.13 s  <---- This unidentified frequency appears strongly on both Top and Middle
22               1/(22/(98))  =  4.45 s   Pendulum Period
29               1/(29/(98))  =  3.38 s   
34               1/(34/(98))  =  2.88 s
36               1/(36/(98))  =  2.72 s   
40               1/(40/(98))  =  2.45 s   
42               1/(42/(98))  =  2.33 s    1/2 Pendulum Period

Based on the 4 runs on Fig. 19 top and middle of NASA's Brady et.al. "Anomalous..." report we can estimate NASA Eagleworks pendulum period, using the Power Spectral Density (from Fast Fourier Transforming the data) as follows:

1) Based on the frequencies corresponding to the 1/2 period:

2*Mean[ 2.31, 2.33] = 4.64

1) Based on the frequencies corresponding to the 1/2 period and the frequencies corresponding to the full period:

Mean[2*2.31,2* 2.33, 4.45,4.73] = 4.62

Both estimates are very close (2.6%) to the period given by Paul March (4.5 seconds)
Title: Re: EM Drive Developments
Post by: Rodal on 11/04/2014 08:36 pm
Thanks. But we need to explain this video before we can attribute the EM Drive thrust in general to chamber wall/cavity interactions.

http://emdrive.com/dynamictests.html (http://emdrive.com/dynamictests.html)


Video clips are near the bottom of the page. I don't see anything in the video that the EM Drive could interact with.

After all this lengthy discussion I have been tracking for a while, what stays with me is the absolute need of more experimental results to talk about. More data points, more confirmations (or refutations).

And the video you bring, while enticing, is alas not enough. I can imagine several ways to trick a video like that, just requiring enough willingness and lack of a consciousness to do it.

Don't get me wrong. I like visual demonstrations as the next guy, it's that we only have this one so far.

But if more people replicated that... we could start becoming really intrigued.

No question that we need more data and more replication.

Operating on the assumption that there is a real force generated by the EM Drive precludes the need to speculate that the data is somehow faked. If we assume that the data is faked and the force is not real then that's the end of the story. No need to go any further.

We here are operating on the assumption that the measurements are real and that the force is from a real EM Drive effect or else it is from an experimental artifact. We are pursuing both lines of investigation so the story ends when we find either the cause of the EM Drive effect or the experimental artifact that fits all of the data we have.  Or when we have exhausted the data available. Without more data the latter seems likely at this point.

I was agreeing with your message up to the point where you wrote "Without more data the latter seems likely at this point".   I disagree with your likelihood forecast as it is only recently that we started really independently examining the data (*), with Fourier Transform, Periodogram, Autocorrelation, Power Spectrum Density, a full model of NASA Eagleworks torsional pendulum as well as classical models (Frobnicat) to numerically explain the results.

(*) as opposed to taking for granted the author's written interpretation of the data.  To our knowledge the authors themselves have not carried out as complete an examination of their data as we are doing (certainly the authors do not have an analytical model for their pendulum behavior as we do, and the author's did not provide an FFT, Periodogram, Autocorrelation, and Power Spectrum of their data as we are doing).

We have shown that the pendulum acts as a complicated filter of what the actual forcing function is, and that it is incorrect to assume that what was measured was necessarily the actual forcing function of the EM Drive.

Unlike the researchers, we are doing this "as a labor of love" on our spare time, so patience is required, but as stated we have already examined the data to a higher level than the published results.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 08:39 pm
@momerathe.... Momentum is a form of energy. Let's not split hairs here.

You're right about rf cancelling out. That's where simultaneously breaking pt symmetry comes in.

Also if they suck the air out of the conical frustum and remove the dielectric the effect should vanish.
Title: Re: EM Drive Developments
Post by: aero on 11/04/2014 08:50 pm
@Rodal - Ok. But note that there are two perspective angles.

1. Its real, caused by ...
2. Its an artifact, caused by ...

Perhaps the data is more nearly exhausted from one perspective than the other? Still, the two perspectives do go hand in glove.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/04/2014 08:57 pm
Ok,

     Admittedly, the math for this a\has finally gotten WAY beyond me.

     Could someone give me an idea of the power to motion ratio that seems to be being generated with this system, verses, say, a regular chemical rocket?

     What I am trying to find out is simple; Is this system somehow generating more motion than should be possible, assuming a direct conversion of energy to motion?

     In other words, is 1 calorie of energy somehow rasing 1 cubic centimeter of water's temprature higher than 1 degree celcius, or is the amount of power being used within a reasonable ratio of energy effecient conversion, say, 70% of power applied is being converted to motion, as an example?

     For the moment, set aside HOW it appears to be doing what it is doing, and let's see if it violates any of the Laws of Thermodynamics.

     Sorry, but you guys have gone so far beyond me mathematically, (plus, I think I may have missed a couple of equations that would have made it simpler to follow) that I am having the devil's own time trying to keep up with this thread.

My take on that (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275281#msg1275281) : it does very clearly violate the laws of thermodynamic unless :
- It gets energy from an "exterior" source. (1/ or 2/ in post linked)
- It emits tachyons (particles of imaginary mass and negative energy) as a way to get rid of an energetic debt. (3/ in post linked)

That it needs more energy than it takes from its onboard generator for a given result can be shown with relatively basic Newtonian mechanics and thought experiment :

Assume a long "railway" in otherwise empty space and a small 1kg ship accelerating along this path by conventionally pushing with wheels. This is the most favorable situation to get momentum from energy. At some time, the ship is going 1km/s=1000m/s (pretty fast for wheels... use whatever magnetic coupling to "rails") and want to go faster. The power it takes to push against a moving thing (the rails are moving relative to the ship) is power=speed*force. Say we want a force of 1N, then it takes 1000*1 = 1000 Watts (1kW) of power. At 1N, a mass of 1kg experiences an acceleration = force/mass = 1/1 = 1m/s²  (that is roughly 0.1g since 1g=9.81m/s²). Ok so, at this 1kW power, at this speed of 1000m/s, 1kW gives an added 1m/s each second.

So after 1s at 1kW we now have a 1kg ship at 1001m/s (speed relative to rails). The energy amount of 1kW during 1s  is energy_used = power * time = 1000 * 1 = 1000 J. We are far from c speeds so kinetic energy is accurately given by energy_kinetic = 0.5*mass*speed².
Before the acceleration : energy_kinetic_before = 0.5*1*1000² = 500000 J
After the acceleration : energy_kinetic_after = 0.5*1*1001² = 501000.5 J
energy_gained = energy_kinetic_after - energy_kinetic_before = 1000.5 J

So we have used 1000 J and we have gained 1000.5 J  Alles ist gut.
All right, there is an annoying .5 J excess which is due to neglecting the fact that it gets a little bit harder to accelerate when going from 1000m/s to 1001m/s. For instance at 1000.5 m/s it would already take 1000.5*1 = 1000.5 W to get the same 1N force that we had at only 1000W when going 1000m/s. So in average we would have to spend exactly 1000.5 J to augment the kinetic energy by 1000.5 J

Now consider the same experiment with a "propellantless system" that would have a thrust to power ratio of 1N/kW, that is in the ballpark of what are claiming the proponents when they are designing their mission profiles. We have the same force of 1N for the same power of 1kW that will get us from 1000m/s to 1001 m/s in 1 second, at the energetic cost of exactly 1000J we gained exactly 1000.5 J in kinetic energy.

This speed of 1000m/s was not chosen randomly by me: the inverse of thrust to power ratio of a propellantless scheme (that is the power to thrust ratio) is the speed beyond which the thruster gives more energy than it takes. It only gets worse (from a conservation of energy standpoint) or better (from a mission profile point of view) when higher speeds are considered :

Same values as above except we are going from 10000 m/s to 10001 m/s :
Gained kinetic energy = 0.5*1*10001² - 0.5*1*10000² = 10000.5 J
Used energy by conventional wheels = (average_speed*force) * time = (10000.5*1)*1 = 10000.5 J
Used energy by propellantless scheme = power*time = 1000*1 = 1000W (you read well, ten times less)

So in effect, with any propellantless scheme of fixed thrust/power ratio we have over unit efficiencies in converting power to kinetic energy the over unit factor being  speed/(power/thrust). And the mission profiles do exploit this over unit factor to the maximum extent permitted by their law (but forbidden by Usual law). And the attempts at explaining how the thrust/power would not be constant but would depend on "speed" to respect energy conservation fail at showing what is the "railway" : what frame would be used as a reference in the vacuum ? Vacuum has no intrinsic "rest speed".

In conclusion, proponents say that energy could be conserved, but they fail to explain how, and worse from an "ethical" standpoint, all their mission profiles critically depend on the fact that energy is not conserved (or is otherwise tapped from "somewhere", the local vacuum or the walls of the Universe, whatever).
Title: Re: EM Drive Developments
Post by: momerathe on 11/04/2014 09:12 pm
@momerathe.... Momentum is a form of energy. Let's not split hairs here.

No, it really isn't. They may be mathematically similar concepts, but they are not the same. This is not splitting hairs; without precision of expression we're not going to get anywhere.
Title: Re: EM Drive Developments
Post by: Rodal on 11/04/2014 09:17 pm
Momerathe, a warm welcome to this forum !
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 09:26 pm
@momerathe.... Momentum is a form of energy. Let's not split hairs here.

No, it really isn't. They may be mathematically similar concepts, but they are not the same. This is not splitting hairs; without precision of expression we're not going to get anywhere.

Fine let's split hairs. If an object has momentum, then it is moving. If it is moving, then it has kinetic energy. And if an object has kinetic energy, then it definitely has mechanical energy... Kinetic energy is a form of energy.

We're not doing a lick of math here. When we do we can use that all you want. We can throw in vector operators when we do math. I can tell that the momentum in a baseball hitting things sure feels like energy to me.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/04/2014 09:30 pm
@momerathe.... Momentum is a form of energy. Let's not split hairs here.

No, it really isn't. They may be mathematically similar concepts, but they are not the same. This is not splitting hairs; without precision of expression we're not going to get anywhere.

Fine let's split hairs. If an object has momentum, then it is moving. If it is moving, then it has kinetic energy. And if an object has kinetic energy, then it definitely has mechanical energy... Kinetic energy is a form of energy.
You are pre-supposing.
Who knows what energy actually is?
Title: Re: EM Drive Developments
Post by: Rodal on 11/04/2014 09:34 pm
....
More info on the Feigel Effect:

http://rspa.royalsocietypublishing.org/content/early/2011/10/06/rspa.2011.0481.full.pdf (A peer review with surprising results!)

http://physics.aps.org/story/v13/st3

The anomalous thrust production from an RF test device was due to the Feigel–van Tiggelen effect.

Interesting paper. Some thoughts occur:
* the dielectric constant in the can will be very low. it's meant to be evacuated, after all.
* the ExB fields in the Feigel effect are steady, those in an EM wave oscillate sinusoidally. Thus the force would be continually swapping direction, and average to zero.
* If you are right, it spells the death-knell for this device as a form of propulsion. From the paper:

Quote
Feigel considers the following situation: a region of a dielectric fluid far from
the boundaries of its container is initially at rest (t = 0). Subsequently, strong
electrical and magnetic fields crossed at right angles to each other are applied
to the region. As the fields reach their constant final values, Eext and Bext for
electrical and magnetic fields, respectively, the fluid is accelerated by the Lorentz
forces (FLorentz ∝ vt(Eext × Bext)) to a final velocity v.

It's a one-off impulse. It can't provide a steady thrust (again, I'm not saying that you're one of the people saying it does) unless you can keep increasing the field forever. When you turn the field off, the dielectric will stop moving. Kind of how the casimir effect provides a one-off energy gain when you bring the two plates together.

The same author has a paper published later, where he concludes that the Feigel effect violates the first law of thermodynamics, as there is work without an energy input:

http://arxiv.org/pdf/1304.3338.pdf
Title: Re: EM Drive Developments
Post by: Mulletron on 11/04/2014 09:43 pm
Good catch. Gotta see what changed their mind. Good thing emdrive only works when it is switched on.
Title: Re: EM Drive Developments
Post by: Rodal on 11/04/2014 09:46 pm
Good catch. Gotta see what changed their mind. Good thing emdrive only works when it is switched on.

Good catch from you in finding this unusual stuff in the first place.   The Proceeding of the Royal Society of London is an excellent journal with outstanding peer review.  Maxwell published his electromagnetic theory in this Journal, Karl Pearson his famous papers on statistics and so on and on...
Title: Re: EM Drive Developments
Post by: aero on 11/04/2014 10:24 pm
Question - Has anyone thought of looking for correlations between Shawyer's thrust profile and Brady's? Be very interesting if something showed up.

The attached plots are from Shawyer's CEAS 2009 paper.
Title: Re: EM Drive Developments
Post by: Rodal on 11/04/2014 10:57 pm
Question - Has anyone thought of looking for correlations between Shawyer's thrust profile and Brady's? Be very interesting if something showed up.

The attached plots are from Shawyer's CEAS 2009 paper.

Good point.

If Frobnicat can scrape the Shawyer data and provide it in a digital form, I could run Power Cross-Spectral Density and Cross-Correlation analysis between them.

However, to my eyesight, the data from Shawyer is very different in that it has that peaking at the end.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/05/2014 09:08 am
As notsosureofit keenly mentioned here: http://forum.nasaspaceflight.com/index.php?topic=29276.msg1282610#msg1282610

You really have to treat the entirety of the cavity as a quantum oscillator to make sense of it. A classical approach doesn't seem to work, but a fully quantum approach yields results.

See slide 15 here:

http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf

I really wish I could find more of this.

This is an interesting throwback to way back (page 96) when I mentioned that I treat EVERYTHING as a wave, particle, and field at the same time, even if something is a macro object. It sounds counter intuitive but that is how I choose to operate and I believe I'm correct in doing so.

Relating to this is that it turns out that even macro objects have a very small hard to measure wave function.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/05/2014 09:51 am
Well I have to see if "PT symmetry breaking" is actually happening here or not. I gotta try and break this theory as best I can.
Title: Re: EM Drive Developments
Post by: momerathe on 11/05/2014 10:16 am
Momerathe, a warm welcome to this forum !

Cheers. I usually try to stay away from speculative physics threads as they are usually hair-tearingly frustrating, but sometimes they get the better of me. ;)


You are pre-supposing.
Who knows what energy actually is?

generations of scientists?

The important thing to remember is that energy is a property of a system. It is not "stuff", even though we often talk about it as if it is. This is, IMO, a bad habit among science communicators.


Relating to this is that it turns out that even macro objects have a very small hard to measure wave function.

Not always small; the current loop in a superconducting wire can be kilometers long and yet have clear quantum characteristics.

The problem is entanglement; macroscopic objects are generally strongly entangled with their surroundings. That means it no longer makes sense to talk about the wavefunction of the object, but instead of the whole system.

(pedantic aside: you cannot measure a wavefunction; it's not an observable.)
Title: Re: EM Drive Developments
Post by: Mulletron on 11/05/2014 10:38 am
Not directly observable. Not measurable, aka "hard to measure." Am I going to have to walk on egg shells with my wording here now? This is getting into a philosophical debate about whether or not for something to be real, it has to be/can be observed. I had a long expose on that philosophy of science way back in the thread concerning Ernst Mach.

I operate as if in order to prove something is "real" you only need to observe it. Be it directly or indirectly. You don't necessarily need to measure it.

What is measurable is limited by technology. Reality goes on being what it is, regardless of it is observable or measurable.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/05/2014 12:29 pm
Carl M. Bender and Stefan Boettcher seem to be the heavy hitters on PT symmetry. Since I don't fully understand PT symmetry, I have to learn about it.

Useful resources I've found:

http://www.thphys.uni-heidelberg.de/~hofmann/ICNAAM2012/Carl.pdf

http://arxiv.org/pdf/quant-ph/0501052v1.pdf

http://arxiv.org/pdf/physics/9712001v3.pdf

http://www.physics.emory.edu/faculty/boettcher/Publications/papers/jmp40_2201.pdf

http://ptsymmetry.net/?page_id=10

http://arxiv.org/pdf/1304.6767v2.pdf (more info on Casimir Momentum of a Chiral Molecule in a Magnetic Field)
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/05/2014 02:24 pm
... the QV is a source of infinite energy. ....

The Quantum Vacuum is by definition the lowest state of energy and cannot be a source of infinite energy.  The idea that one can get infinite energy from the quantum vacuum rests on the singularities of quantum electrodynamics (before renormalization).  No leading university or leading research institution has people believing that the Quantum Vacuum is a source of infinite energy. One has to distinguish between the singularities in mathematical models from physical reality.  In classical mechanics there are also all kinds of singularities, that are recognized as non-physical.

In fact Dr. White tried to do his doctoral thesis on his QVF model, which he had adopted as an engineer before ever going back to school for his PhD, and he was turned down on that thesis because there is no respect for QVF, ZPF and the like in academia for that nonsense.  There are reasons why people like Sean Carroll have been so uncharacteristically abusive of the idea--because it's a crackpot idea.  Virtual particles that cannot gravitate, cannot mediate any kind of momentum exchange.  This is by definition!  And yet, there are dozens of crackpot schemes on the web that all wave the ZPF or QVF wand over them and people just stop thinking.

Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/05/2014 02:42 pm
I operate as if in order to prove something is "real" you only need to observe it. Be it directly or indirectly. You don't necessarily need to measure it.

What is measurable is limited by technology. Reality goes on being what it is, regardless of it is observable or measurable.
It's fine to operate with whatever criteria you like, but it's also important to note what is meant when physicists precise between "real" particles and "virtual" particles.  In that distinction, virtual particles cannot mediate momentum transfer because they do not have inertial nor gravitational mass, and because their lifetimes are hugely curtailed.  And this is in fact why Sean Carroll loses patience with the madness--because it is stipulating in spite of what the concept actually means.  Since "virtual" mean no mass, it is not going to be useful for gathering energy or generating momentum.  Hence it is the field of crackpots when they make these kinds of claims.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/05/2014 02:49 pm
Well I'm having doubts about the chirality of Polyethylene and Polytetrafluoroethylene. It seems that testing the chirality of polymers is a bit different than testing the chirality of non repeating molecules. I can tell you that testing for chirality in the structural formula of the monomers of PE and PTFE doesn't seem to hold to me; but the repeating units does appear to hold sometimes. Looking at ball models of the repeating structure of these materials, I see chirality. I need a sanity check here on the chirality of these polymers before I go and waste energy on something that isn't there.

I'm trying to tear apart my own "theory" here.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/05/2014 02:52 pm
Ron, they've been abusive to the idea of QVPT because of the unfortunate use of the word plasma. The QV in and of itself is accepted and supported by experiment after experiment.

And Rodal and Momerathe were correct in calling me out for using the word energy instead of momentum. I get it. That imprecise language I used led to confusion between what was said (an unlimited source of energy, ergo quackery) and what was meant (an unlimited momentum well). Some of my own medicine actually. I complained a lot on here about precision of language. Oh well live and learn.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/05/2014 03:02 pm
Still bumbling around looking for interaction mechanisms..............

http://arxiv.org/pdf/1303.0733v1.pdf

See: p.19, F. Microwave resonators
Title: Re: EM Drive Developments
Post by: Mulletron on 11/05/2014 03:21 pm
Still bumbling around looking for interaction mechanisms..............

http://arxiv.org/pdf/1303.0733v1.pdf

See: p.19, F. Microwave resonators

Well I was thinking it was vacuum polarization. I've been reading a lot about that and ways to work Compton scattering into the context of the QV. Also, way back I was looking at the diamagnetism of the QED vacuum as an exploit.

http://isites.harvard.edu/fs/docs/icb.topic521209.files/QFT-Schwartz.pdf
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/05/2014 03:28 pm
Ron, they've been abusive to the idea of QVPT because of the unfortunate use of the word plasma. The QV in and of itself is accepted and supported by experiment after experiment.
I'm sorry but that's just not even close to true.  I've watched this debate for more than 10 years, and what I wrote is the truth.  The QVF model, and the ZPF theory before it both require virtual particles to transfer momentum and they have no mass to do this.  They are both for this reason, broken theories.  Momentum transfer and energy transfer using particles, certainly requires the particles have mass, and virtual particles do not--indeed they CANNOT or the universe would collapse under its own weight.

And again I would remind you, that the only evidence for these mistaken beliefs is Casimir Effect, which is easily explained with no reference to ZPF or QVF at all.  These are merely consistent with Casimir Force.  The fact of Casimir in no way requires ZPF nor QVF.  People who think this have been bamboozled, and whole books exist to give people this mistaken impression.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/05/2014 03:35 pm
Ron, they've been abusive to the idea of QVPT because of the unfortunate use of the word plasma. The QV in and of itself is accepted and supported by experiment after experiment.
I'm sorry but that's just not even close to true.  I've watched this debate for more than 10 years, and what I wrote is the truth.  The QVF model, and the ZPF theory before it both require virtual particles to transfer momentum and they have no mass to do this.  They are both for this reason, broken theories.  Momentum transfer and energy transfer using particles, certainly requires the particles have mass, and virtual particles do not--indeed they CANNOT or the universe would collapse under its own weight.

And again I would remind you, that the only evidence for these mistaken beliefs is Casimir Effect, which is easily explained with no reference to ZPF or QVF at all.  These are merely consistent with Casimir Force.  The fact of Casimir in no way requires ZPF nor QVF.  People who think this have been bamboozled, and whole books exist to give people this mistaken impression.

Okay I'm going to be nice here and just say that something doesn't need rest mass to have momentum. Look at photons.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/05/2014 04:06 pm
You're muddling the issue by stipulating "rest".  Virtual particles have no mass at any time, of any kind.  If they did they would gravitate and collapse the universe.  The fact we distinguish between virtual and real photons should be explanation enough.  Photons have mass unless they're virtual, and virtual particles cannot mediate momentum nor energy transfer.  This is by definition, and it is when people redefine virtual particles to suit their pet theories, that the folks like Sean Carroll get so upset.

Virtual particles are not necessary to do any physics.  They're an invention for people who like to see field phenomena in terms of particle exchange, but the fields are enough.  You don't need the particles for anything.  They're really just a form of pandering to the need to see things in terms of particles which are really field phenomena.  the graviton is another example of this.  We have never found one, despite looking for 4 generations, but most people believe in gravitons anyway.  That's because particle theory is so emotionally satisfying.  It lends itself to the emotional need to feel we know what's going on when fields are the opposite--quite mysterious by nature.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/05/2014 04:13 pm
Well all this reading about PT symmetry, polymer chirality and SED is mind numbing. Time to walk away from this for a while and let it sink in. It's beer time.

Edit:

They are truly chiral!

http://www.chem1.com/acad/webtext/states/polymers.html

Seriously I need to walk away from this for real this time.
Title: Re: EM Drive Developments
Post by: Rodal on 11/05/2014 07:40 pm
Next batch of scraped data from figure 19 page 15 of "anomalous thrust..." from Brady et al (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf). The top (result1.txt) and middle (result2.txt) graphs are scraped.

Same caveats as previously posted (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281007#msg1281007). For first curve (top figure 19) I removed the (non existent) flat last sampled data of the previous version to avoid artefacts when analysing with filters.

Each line of those files is the value in µN at each .1 s interval (linearly interpolated from manual reconstruction). The vertical scale were roughly given by the calibration pulses at about 30µN (expect no more than 5% precision). Absolute values are arbitrary (because of the drifting baseline). Horizontal scale given by the indication of 196 s for the whole display graph window of the pictures.

Will proceed with other graphs when time permits. Will post attempts at original signal reconstruction : thrust(t) while what we see is only balance displacement(t). Since the balance is underdamped, a lot can hide behind those oscillations and drifts in position.

Frobnicated Top of Fig. 19 page 15 of anomalous (Mean and Linear Least Squares Fit)


Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue)

Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Linear LS (Red)


Power Spectral Density (from FFT)  on raw data detrended by Linear LS (Red)

horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*94.6

Peaks         Period (seconds)
3                 1/(3/(94.6))  = 31.53 s   Pulse period
5                 1/(5/(94.6))  = 18.92 s   4*Pendulum Period
7                 1/(7/(94.6))  = 13.51 s
10               1/(10/(94.6))  = 9.46 s   2*Pendulum Period
15               1/(15/(94.6))  = 6.31 s <---- This unidentified frequency appears on both Top and Middle
18               1/(18/(94.6))  = 5.26 s
20               1/(20/(94.6))  = 4.73 s    Pendulum Period
25               1/(25/(94.6))  = 3.78 s
41               1/(41/(94.6))  = 2.31 s    1/2 Pendulum Period

Frobnicated Middle of Fig. 19 page 15 of anomalous NASA report (Mean, Linear Least Squares Fit and Quadratic Least Squares Fit)


Autocorrelation of Middle of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue), by Linear LS (Red) and by Quadratic LS (Green)


Power Spectral Density of Middle of Fig. 19 page 15  (from FFT) on raw data detrended by Quadratic LS (Red)

horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*98

Peaks         Period (seconds)
3                 1/(3/(98))  =  32.67 s   Pulse period
5                 1/(5/(98))  =  19.60 s   4*Pendulum Period
7                 1/(7/(98))  =  14..00 s
12               1/(13/(98))  =  7.54 s 
16               1/(16/(98))  =  6.13 s  <---- This unidentified frequency appears strongly on both Top and Middle
22               1/(22/(98))  =  4.45 s   Pendulum Period
29               1/(29/(98))  =  3.38 s   
34               1/(34/(98))  =  2.88 s
36               1/(36/(98))  =  2.72 s   
40               1/(40/(98))  =  2.45 s   
42               1/(42/(98))  =  2.33 s    1/2 Pendulum Period

The attached plot shows the Power Spectral Density for the detrended joint data from Fig. 19 Top and Middle, for periods ranging from 12 seconds to approximately 1 second.

It is evident that:

1) The strongest period (taking into account decay of Power density with frequency) is 2.32 seconds, which corresponds to the half period of NASA's Eagleworks pendulum.  The half-period is also the most evident pattern of Fig. 19 to my eyes.

2) NASA's Eagleworks pendulum, acts as an effective filter for frequencies below the 1/2 period of the pendulum

3) The strong power corresponding to the 6.42 seconds period is 8% below 3 times the pendulum half period (this 8% difference is real and not part of uncertainty, as the amount of data permits to discriminate within 3% at that frequency)

4) The 9.63 seconds period corresponds to twice the pendulum period.
Title: Re: EM Drive Developments
Post by: aero on 11/05/2014 07:51 pm
All I ever wanted to know about Maxwell's equations, and more, including evanescent waves.

http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-013-electromagnetics-and-applications-spring-2009/readings/MIT6_013S09_chap09.pdf (http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-013-electromagnetics-and-applications-spring-2009/readings/MIT6_013S09_chap09.pdf)

Evanescent fields/waves are more versatile than simply providing power coupling and quantum tunneling ... I guess.
Title: Re: EM Drive Developments
Post by: Rodal on 11/05/2014 07:55 pm
All I ever wanted to know about Maxwell's equations, and more, including evanescent waves.

http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-013-electromagnetics-and-applications-spring-2009/readings/MIT6_013S09_chap09.pdf (http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-013-electromagnetics-and-applications-spring-2009/readings/MIT6_013S09_chap09.pdf)

Evanescent fields/waves are more versatile than simply providing power coupling and quantum tunneling ... I guess.
That's part of MIT's Electrical Engineering undergraduate course 6.013, for the other chapters and video clips also see this:  http://web.mit.edu/6.013_book/www/
Title: Re: EM Drive Developments
Post by: frobnicat on 11/05/2014 08:30 pm

The attached plot shows the Power Spectral Density for the detrended joint data from Fig. 19 Top and Middle, for periods ranging from 12 seconds to approximately 1 second.

It is evident that:

1) The strongest period (taking into account decay of Power density with frequency) is 2.32 seconds, which corresponds to the half period of NASA's Eagleworks pendulum.  The half-period is also the most evident feature of the data to a person's eyesight.

2) NASA's Eagleworks pendulum, acts as an effective filter for frequencies below the 1/2 period of the pendulum

3) The strong power corresponding to the 6.42 seconds period is 8% below 3 times the pendulum half period (this 8% difference is real and not part of uncertainty, as the amount of data permits to discriminate within 3% at that frequency)

4) The 9.63 seconds period corresponds to twice the pendulum period.

Hi there %)

Rodal, you should be aware and cautious of the fact that those data points are a linear piecewise reconstruction by hand from a badly compressed picture of a low definition display. While I was trying to fit as best as I could without introducing bias, I put vertex at the "visually central" position only where it made sense : it means that there is not a lot of points on a given "wave". After correction for perspective (bilinear interpolation, should be pretty good at restoring "flat" upright geometry) the data points at each .1s were obtained from this piecewise linear curve by averaging a sampling (at .01s resolution) .1s on left and right of said data point, so there is a slight smoothing (low pass filtering) going on at this stage. Even with this smoothing around, a lot of consecutive data points are given by the same segment, and I guess we have shapes more triangular than they should (triangle crests instead of sinusoidal bumps) : this surely introduces some harmonics and might explain the magnitude of this half period (twice freq.) relative to the magnitude of the central period of 4.65 (or so).

I don't get what you are saying with "The half-period is also the most evident feature of the data to a person's eyesight." You mean that people see more the horizontal distance between bump and next dip than between two successive bumps ? Or that you see a (non alternated) pattern repeating at 2.32 s ? No vocabolurary flame please, just trying to understand what you see. Vacobolury, vocubolary, vocabulary, that's it.
Title: Re: EM Drive Developments
Post by: Rodal on 11/05/2014 09:00 pm

The attached plot shows the Power Spectral Density for the detrended joint data from Fig. 19 Top and Middle, for periods ranging from 12 seconds to approximately 1 second.

It is evident that:

1) The strongest period (taking into account decay of Power density with frequency) is 2.32 seconds, which corresponds to the half period of NASA's Eagleworks pendulum.  The half-period is also the most evident feature of the data to a person's eyesight.

2) NASA's Eagleworks pendulum, acts as an effective filter for frequencies below the 1/2 period of the pendulum

3) The strong power corresponding to the 6.42 seconds period is 8% below 3 times the pendulum half period (this 8% difference is real and not part of uncertainty, as the amount of data permits to discriminate within 3% at that frequency)

4) The 9.63 seconds period corresponds to twice the pendulum period.

Hi there %)

Rodal, you should be aware and cautious of the fact that those data points are a linear piecewise reconstruction by hand from a badly compressed picture of a low definition display. While I was trying to fit as best as I could without introducing bias, I put vertex at the "visually central" position only where it made sense : it means that there is not a lot of points on a given "wave". After correction for perspective (bilinear interpolation, should be pretty good at restoring "flat" upright geometry) the data points at each .1s were obtained from this piecewise linear curve by averaging a sampling (at .01s resolution) .1s on left and right of said data point, so there is a slight smoothing (low pass filtering) going on at this stage. Even with this smoothing around, a lot of consecutive data points are given by the same segment, and I guess we have shapes more triangular than they should (triangle crests instead of sinusoidal bumps) : this surely introduces some harmonics and might explain the magnitude of this half period (twice freq.) relative to the magnitude of the central period of 4.65 (or so).

I don't get what you are saying with "The half-period is also the most evident feature of the data to a person's eyesight." You mean that people see more the horizontal distance between bump and next dip than between two successive bumps ? Or that you see a (non alternated) pattern repeating at 2.32 s ? No vocabolurary flame please, just trying to understand what you see. Vacobolury, vocubolary, vocabulary, that's it.

Hi there,

I meant that what strikes me first is that I see the 1/2 period harmonic pattern.  I meant nothing else.  Nothing about seconds.  Nothing about horizontal or vertical distance.



I would appreciate to know if you questioned calling the Eagleworks pendulum "inverted", for curiosity or because you object to that description  and if so what would you like to call it and why. ( http://forum.nasaspaceflight.com/index.php?topic=29276.msg1282051#msg1282051 )

No vocabulary flame please just trying to understand if I missed or failed to notice something with the Eagleworks pendulum



Concerning why the frequency corresponding to the total period has relatively low power, and the 1/2 period has much higher power I think it is due to the high damping value that noticeably dampens the response such that when the power is turned on the first peak (dynamic magnification) has greater amplitude excursion than the second excursion.  Actually the subsequent peaks are much less well-defined and appear muddled in the picture.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=619422;image)
Title: Re: EM Drive Developments
Post by: frobnicat on 11/05/2014 10:31 pm
I would appreciate to know if you questioned calling the Eagleworks pendulum "inverted", for curiosity or because you object to that description  and if so what would you like to call it and why. ( http://forum.nasaspaceflight.com/index.php?topic=29276.msg1282051#msg1282051 )

No vocabulary flame please just trying to understand if I missed or failed to notice something with the Eagleworks pendulum

It's just that I didn't feel my remark/question deserved so much energy (heat wave!) as your answer used, so I was a bit embarrassed at answering (and had not much time to laboriously knead my words). I'm already under surveillance at my work for too much verbose production (not a surprise).

It was a matter of connotation, as I worked (time ago, also too much verbose) on emergent adaptive control of inverted pendulum, the unstable one with active stabilisation (actuator...) so is for me inverted => mass above pivot & unstable equilibrium. I am not aware of any application for measurement purposes of such unstable equilibrium system. There are measurement application for near unstable systems where a centre of mass is not far from being above pivot, but still below so that it's not really inverted and not unstable, just very sensitive, and with long period, like Lehman seismometer (from this site (http://www.phy.mtu.edu/~suits/PH3110/pendulums.html)):
(http://www.phy.mtu.edu/~suits/PH3110/wordlehm.gif)

Also we have this very fine device (by nineteenth century standards) from von Rebeur Paschwitz
(http://earthquake.usgs.gov/learn/topics/seismology/history/figures/fig_19.gif)
that's called an horizontal pendulum (from this site (http://earthquake.usgs.gov/learn/topics/seismology/history/part09.php)) on the same principle that a very slightly tilted almost vertical axis will allow for a weak restoring force toward equilibrium. This is not exactly fresh news and may be outdated.

For the kind of balance used at eaglework I would go onto something of the line of "horizontal spring pendulum" (only in better English). Or why not just stick with "torsion pendulum" or "torsional pendulum" as the (ideal) movement is kept in an horizontal plane and the force restoring to (stable) equilibrium is given by a spring constant ? Why need "inverted" ? Was the question.

Now, the funny thing is that, with all that stuff (rf amp. and EMthruster) above the beam of the balance, we are indeed in an "inverted" situation from this point of view, that is for the rotation around the x axis (and maybe y?) centre of mass is above "pivots". In this axis, this should be rather stiff with the two flexure bearings mounted apart, but I wonder how far we are from unstability.

So it all boils down to feelings of the word  inverted => centre_of_mass_above_pivot => unstable. The later implication being wrong if restoring force stiff enough, so maybe it no longer "deserve" the qualifier of "inverted". Just a matter of wordings, not of concepts, I guess we agree on the functioning and stability (or lack thereof) of the balance at hand.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/05/2014 10:57 pm
Quote from: Rodal
Quote from: frobnicat
.../...
I don't get what you are saying with "The half-period is also the most evident feature of the data to a person's eyesight." You mean that people see more the horizontal distance between bump and next dip than between two successive bumps ? Or that you see a (non alternated) pattern repeating at 2.32 s ? No vocabolurary flame please, just trying to understand what you see. Vacobolury, vocubolary, vocabulary, that's it.

I meant that what strikes me first is that I see the 1/2 period harmonic pattern.  I meant nothing else.  Nothing about seconds.  Nothing about horizontal or vertical distance.
.../...

Maybe again a problem of wording, and eye maybe. What my eyes see as pattern is "something that is similar when shifted laterally in position by some amount". And the translation needed to put the crest on the next crest and the dip on the next dip is, well, a full period of about 4.6 s, not 2.3s ? Do I have a real problem of translation here (quite possible) ?
Title: Re: EM Drive Developments
Post by: Rodal on 11/05/2014 11:40 pm
Quote from: Rodal
Quote from: frobnicat
.../...
I don't get what you are saying with "The half-period is also the most evident feature of the data to a person's eyesight." You mean that people see more the horizontal distance between bump and next dip than between two successive bumps ? Or that you see a (non alternated) pattern repeating at 2.32 s ? No vocabolurary flame please, just trying to understand what you see. Vacobolury, vocubolary, vocabulary, that's it.

I meant that what strikes me first is that I see the 1/2 period harmonic pattern.  I meant nothing else.  Nothing about seconds.  Nothing about horizontal or vertical distance.
.../...

Maybe again a problem of wording, and eye maybe. What my eyes see as pattern is "something that is similar when shifted laterally in position by some amount". And the translation needed to put the crest on the next crest and the dip on the next dip is, well, a full period of about 4.6 s, not 2.3s ? Do I have a real problem of translation here (quite possible) ?

Well, we all have different minds, and experience.  When looking at a strongly damped sinusoid my mind sees a pattern of different 1/2 periods, each having a different amplitude. 

I changed my wording to "The half-period is also the most evident pattern of Fig. 19 to my eyes."
Title: Re: EM Drive Developments
Post by: aero on 11/05/2014 11:40 pm
I have finished tracing the cavity RF wave through to momentum of evanescent waves. It may or may not fly as the origination of the measured force due to a few things.

1. Need to either reconcile the geometry with the force or discover that evanescent waves can be created by incident EM waves at less than the critical angle.

2. Need to discover that evanescent waves can be created through the thickness of the copper boundary.

I sketched together a Microsoft Word paper which is attached. Be warned, the math in the references is heavy.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/06/2014 12:39 pm
You're muddling the issue by stipulating "rest".  Rest mass is actually a thing. I'm not muddeling. Virtual particles have no mass at any time, of any kind.  Where did you get your thorough understanding of the QV and virtual particles from? It is still a subject of intense research. You appear to be in the lead. Congratulations! If they did they would gravitate and collapse the universe. You are making a hasty assumption here. Did you consider their stochastic nature? The fact we distinguish between virtual and real photons should be explanation enough. No content here. Photons have mass unless they're virtual, and virtual particles cannot mediate momentum nor energy transfer. You know something the rest of the world doesn't. This is by definition, and it is when people redefine virtual particles to suit their pet theories (who? citation needed), that the folks like Sean Carroll get so upset. You're speaking on behalf of someone else. Would they appreciate that? Are you acknowledging that virtual particles exist but not the QV?

Virtual particles are not necessary to do any physics.  Virtual particles need not be material in order to be considered real. Their influence is seen in the material world, Zitterbewegung et al, and they are a useful mathematical accounting tool. You see them in Feynman diagrams. Their effects must also be adjusted for in calculations and also subtracted out by renormalization. They're an invention for people who like to see field phenomena in terms of particle exchange, but the fields are enough. Inventions are okay if they are useful and hold true. You don't need the particles for anything. Says you? They're really just a form of pandering to the need to see things in terms of particles which are really field phenomena.  the graviton is another example of this.  We have never found one, despite looking for 4 generations, but most people believe in gravitons anyway. I don't believe in gravitons either, however it is a popular theory that hasn't been ruled out. That's because particle theory is so emotionally satisfying. I don't get all emotional over particles. Beer is satisfying to me, not particles. It lends itself to the emotional need (see below) to feel we know what's going on when fields are the opposite--quite mysterious by nature. "Sometimes I just don't get it."



Pretty much everything quoted above is either factually inaccurate, a logical fallacy, or a cognitive bias. The rest is weasel words. This is the last time I ftt. I value your inputs but when you go on these anti QV rants, it is just too much. My "word by word" comments are in blue. My thoughts are that if someone has issue with a theory that's fine. But they should have a constructive rebuttal too. What is your alternate theory? Do you have a personal stake in something else that makes you just not like anything to do with EMdrive? Is it because it isn't Woodward's theory? What gives? Should we just not give EMdrive any attention whatsoever?

My apologies for any mistakes I may have made in my statements or vocabulary.  :)

Very respectfully,
Mulletron

http://www.youtube.com/watch?v=0YjSHbA6HQQ
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/06/2014 01:26 pm
Momerathe, a warm welcome to this forum !

Cheers. ...

And... might I ask when was the last time you "outgrabe"?  Or am I reading far too much in your moniker?

You are pre-supposing.
Who knows what energy actually is?

Quote from: Momerathe
generations of scientists?

The important thing to remember is that energy is a property of a system. It is not "stuff", even though we often talk about it as if it is. This is, IMO, a bad habit among science communicators.

Paraphrasing Albert here:

Property = Stuff times c^2

Those of us who subsist on peanuts tend to think of energy as a type of "stuff".  And since momentum = stuff times speed, it's not too surprising that we think so.

Personally, if photons have momentum, they, to me, must have some kind of mass, and therefore, there must be, in my peanutular analysis, some kind of rest mass associated with photons.  So what happens if you freeze light?  does this pertain to the discussion at hand?

Theatrical and dramatic, but still, about frozen light:

http://www.youtube.com/watch?v=EK6HxdUQm5s

So Rodal:  Do you know Seth Lloyd?  Peter Shor?

I just started watching this this one:

http://www.youtube.com/watch?v=96g4GGt1TJA
Title: Re: EM Drive Developments
Post by: Rodal on 11/06/2014 01:30 pm
You're muddling the issue by stipulating "rest".  Rest mass is actually a thing. I'm not muddeling. Virtual particles have no mass at any time, of any kind.  Where did you get your thorough understanding of the QV and virtual particles from? It is still a subject of intense research. You appear to be in the lead. Congratulations! If they did they would gravitate and collapse the universe. You are making a hasty assumption here. Did you consider their stochastic nature? The fact we distinguish between virtual and real photons should be explanation enough. No content here. Photons have mass unless they're virtual, and virtual particles cannot mediate momentum nor energy transfer. You know something the rest of the world doesn't. This is by definition, and it is when people redefine virtual particles to suit their pet theories (who? citation needed), that the folks like Sean Carroll get so upset. You're speaking on behalf of someone else. Would they appreciate that? Are you acknowledging that virtual particles exist but not the QV?

Virtual particles are not necessary to do any physics.  Virtual particles need not be material in order to be considered real. Their influence is seen in the material world, Zitterbewegung et al, and they are a useful mathematical accounting tool. You see them in Feynman diagrams. Their effects must also be adjusted for in calculations and also subtracted out by renormalization. They're an invention for people who like to see field phenomena in terms of particle exchange, but the fields are enough. Inventions are okay if they are useful and hold true. You don't need the particles for anything. Says you? They're really just a form of pandering to the need to see things in terms of particles which are really field phenomena.  the graviton is another example of this.  We have never found one, despite looking for 4 generations, but most people believe in gravitons anyway. I don't believe in gravitons either, however it is a popular theory that hasn't been ruled out. That's because particle theory is so emotionally satisfying. I don't get all emotional over particles. Beer is satisfying to me, not particles. It lends itself to the emotional need (see below) to feel we know what's going on when fields are the opposite--quite mysterious by nature. "Sometimes I just don't get it."



Pretty much everything quoted above is either factually inaccurate, a logical fallacy, or a cognitive bias. The rest is weasel words. This is the last time I ftt. I value your inputs but when you go on these anti QV rants, it is just too much. My "word by word" comments are in blue. My thoughts are that if someone has issue with a theory that's fine. But they should have a constructive rebuttal too. What is your alternate theory? Do you have a personal stake in something else that makes you just not like anything to do with EMdrive? Is it because it isn't Woodward's theory? What gives? Should we just not give EMdrive any attention whatsoever?

My apologies for any mistakes I may have made in my statements or vocabulary.  :)

Very respectfully,
Mulletron


Signing "Very respectfully" a post that charges "Pretty much everything quoted above is either factually inaccurate, a logical fallacy, or a cognitive bias. The rest is weasel words. " does not make it respectful.

The subject being discussed in this thread is EM Drives and Spaceflight.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/06/2014 01:40 pm
Some of my own medicine actually. I complained a lot on here about precision of language. Oh well live and learn.

I know how that feels.  Try a spoonful of sugar...

Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/06/2014 01:52 pm
Hah!  The five anomalies:

(From that hour long video I just posted)

1. Quantization of red shift.
2. Decreasing values of speed of light.
3. Increasing value of Plank's constant h.
4. Increasing atomic mass.
5. Slowing rate of the ticking of atomic clocks.

It seems like h times c might actually be a constant.

Plus a bonus track!

The astronomer runs into the mathemetician's office, saying "I've discovered that all od numbers are primes!"

"What?", sez the mathematician.

"Look!  1, 3, 5, 7... all primes!" sez the astronomer, "It gets better! 11, 13, 17, 19!"

"Uhhhh.... what about 9 and 15?"

"Oh that.  That's just observational error."

Anyhow:  They're not constants! 

They're habits.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/06/2014 02:22 pm
Quote
Signing "Very respectfully" a post that charges "Pretty much everything quoted above is either factually inaccurate, a logical fallacy, or a cognitive bias. The rest is weasel words. " does not make it respectful.

The subject being discussed in this thread is EM Drives and Spaceflight.

Well I am smart enough to recognize an agent provocateur on a forum whose mission is to create fear, uncertainty, and doubt. FUD. Because they have a conflict of interest (all things Woodward and his book). We've been here. I remember his treatment of Dr. M for example. So I calls em like I sees em. As I said, this is the last time I ftt. Giving in to the FUD creates distractions which is what they want. Back to the subject at hand, EMdrives and the science for or against them.

Thank you for your patience.
Title: Re: EM Drive Developments
Post by: momerathe on 11/06/2014 03:37 pm
Let's talk about virtual particles.

Insofar as we think of virtual particles as a prediction/phenomenon of Quantum Field Theory, they are perfectly understood, and have been for decades. However, we know that QFT is incomplete, requiring reconciliation with General Relativity.

Ditto the quantum vacuum; within the framework of QFT we understand it - or we should, except for what's been called "the worst theoretical prediction in the history of physics"; the failure to predict the value of vacuum energy. This too, we assume, must be due to in the incompleteness of QFT in some regard.

Under the tenets of QFT, the quantum vacuum cannot be "pushed against" (save by creating real particles) - any attempt to justify the EMdrive or QVPT as a working device by an appeal to currently understood principles of quantum mechanics is doomed to failure, because regardless of its internal workings we already know the answer.

For these devices to work, they must work via a novel principle of physics that extends QFT in some way. If they do work, it will herald a revolution in fundamental physics. However, extraordinary claims require extraordinary evidence.

(to be clear - when I say "work", I mean function as a form of propulsion. This presupposes that the results claimed are not some sort of anomaly which may be explicable conventionally.)

The only reason I'm not shooting this down out of hand is that we know a novel principle of physics must exist, because we know QFT is incomplete. What we don't know is if this extension is one that allows the quantum vacuum to act as a momentum sink. To be honest, I'm not even sure how one would begin to speculate about it.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/06/2014 03:44 pm
I like what you're saying up there. This quote holds true, "I think I can safely say that nobody understands quantum mechanics." ~Feynman.

I do think I have not been heard or was misunderstood. I stated that we're not pushing on the QV. The QV is pushing on us. The novel physics you speak of is allowing this to happen in a preferred direction. I postulate.

I like the brand of precise tempered reason you bring to the table.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/06/2014 03:52 pm
... we know a novel principle of physics must exist, because we know QFT is incomplete. What we don't know is if this extension is one that allows the quantum vacuum to act as a momentum sink. To be honest, I'm not even sure how one would begin to speculate about it.

In a nutshell, this thread begins the speculation that you suggest, at least, the way I grok it.  While the eperimentor's results may be sloppily reported, Frobnicat, Aero, Mulletron, and Rodal seem to be investigating "novel" possibilities.

Quote
to be clear - when I say "work", I mean function as a form of propulsion.

Preagmatic utility is kinda the way I phrase it, but the English meaning of your term there is not at all ambibuous.

I still don't get the utility of considering "virtual particles" as having "reality", other than in my poorly comprehended thinking that they complete certain aspects of the mathematical theory.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/06/2014 03:53 pm
I like what you're saying up there. This quote holds true, "I think I can safely say that nobody understands quantum mechanics." ~Feynman.

I do think I have not been heard or was misunderstood. I stated that we're not pushing on the QV. The QV is pushing on us. The novel physics you speak of is allowing this to happen in a preferred direction. I postulate.

I like the brand of precise tempered reason you bring to the table.

IDK, but it sounds like, by "preferred direction", you end up meaning that we can indeed push on the QV.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/06/2014 04:02 pm
I like what you're saying up there. This quote holds true, "I think I can safely say that nobody understands quantum mechanics." ~Feynman.

I do think I have not been heard or was misunderstood. I stated that we're not pushing on the QV. The QV is pushing on us. The novel physics you speak of is allowing this to happen in a preferred direction. I postulate.

I like the brand of precise tempered reason you bring to the table.

IDK, but it sounds like, by "preferred direction", you end up meaning that we can indeed push on the QV.

I realized that I couldn't reasonably find a way to justify saying the QV could be pushed on. I can't push on something that is random and fleeting. But I know the QV interacts with the real world in subtle ways. So I changed my approach and realized the QV is doing the pushing. Normally in a symmetric situation, this push amounts to no preferred direction due to local and global symmetry. The asymmetries in the system (see papers linked to previously), allow the QV to push more in one direction than the other, when the EMdrive is energized. There is a mechanism, the papers hint at, that is inducing a spontaneous PT symmetry break, allowing this to happen.

A broad range of literature is littered with hints that spontaneous PT symmetry breaking is a real thing. It could be happening inside EMdrive too.

Discrete symmetries are known to be broken in our universe, alone and in pairs, and are a common occurrence. We all owe our existence to these broken symmetries.
Title: Re: EM Drive Developments
Post by: aero on 11/06/2014 04:50 pm
Some nice features about Evanescent waves
- Energy is conserved WRT momentum. Excitation energy flows as current along the outside of the cavity. A resistance loss to the system.
- Momentum is caused by reaction. Energy flows, the magnetic field builds perpendicular to the wall, that is 90 degrees from the direction of current flow. The field collapses converting magnetic flux to momentum.

Point is, Evanescent waves provide a mechanism for the RF field within the cavity to produce momentum outside the cavity and still stay within the bounds of physics as we understand it.

It will take a better mathematician than I to determine the strength and direction of this momentum but to me, it seems that the evanescent fields must be created along the tapered sides of the cone. That is where the geometry gives the wave/wall angle less than the critical angle. 

Add: The Evanescent wave explanation requires no new physics, though it does require some of the latest developments in our understanding of it. And I suspect there are still some factors to be explained because the EM force has been measured from cavities of different shapes. Not all of the shapes are conic so discovering the critical angle in all cases may not be straight forward.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/06/2014 05:24 pm
Here ya go:

http://www.nature.com/ncomms/2014/140306/ncomms4300/full/ncomms4300.html

http://arxiv.org/abs/1308.0547

http://phys.org/news/2014-03-extraordinary-momentum-evanescent.html

You take it from here. I'll leave you with what I learned and lessons learned. I ran into difficulties proving the surface plasmons could appear on the surface of the cavity given the unknown thickness and lack of official precedent in the literature, the complexities of quantifying the critical angle with a cone, and the crazy math. I learned that the critical angle is dependent on the lower cutoff frequency of the waveguide and the refractive index valid for that frequency, which for this article I calculated from 6.25 inches to be 1889.76Mhz. I never got the refractive index for copper at this frequency and I got confused about how this would work because copper is a conductor. Skin depth becomes important here. Copper does have a refractive index though. So my knowledge of how this works is limited. I posted a thing about it back there. The best I did was prove that evanescent wave resonant coupling with RF was indeed a very common thing and that quantum tunneling with RF was just the same as it is with light frequencies. See the videos I posted way back of the optical and RF prisms. I learned that evanescent fields due to the critical angle mechanism are non propagating, static and contain no energy. They must couple with another resonator capable of accepting the leaky mode in order tunnel through and propagate. Most importantly, what I learned, is that this phenomena is described in a bunch of related ways that have different and imprecise terminology, and it is described classically and quantumly, leading to difficulty in finding clarity. Oh yeah....most of the research I found dealt with dielectric waveguides, which allow both E and H evanescent fields/surface plasmons to escape, but in an air-metal-air interface, only H evanescent fields/plasmons tunnel through. E can't get through. God speed. These are strange indeed.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/06/2014 07:47 pm
It has been on my to do list to share this with the group. Dr. White lays out some math and a proof starting on slide 41 in the backup slides.
Title: Re: EM Drive Developments
Post by: Rodal on 11/06/2014 08:13 pm
It has been on my to do list to share this with the group. Dr. White lays out some math and a proof starting on slide 41 in the backup slides.
We have discussed this presentation with Frobnicat about a hundred pages along.  Ron Stahl has also commented on this work.

No formulas or math in this presentation are applicable to obtain thrust estimates for the EM Drives.

I have referred to slides 45 and 46 of this presentation some pages ago: White shows the spreadsheet without showing what are the equations behind the spreadsheet predictions.  I also commented on the fact that the direction of the force predicted (ExB) is perpendicular to the displacements measured in the "Anomalous..." report.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/06/2014 08:20 pm
Slide 43 and 44.
Title: Re: EM Drive Developments
Post by: aero on 11/06/2014 08:32 pm
@Mulletron -
Quote
Most importantly, what I learned, is that this phenomena is described in a bunch of related ways that have different and imprecise terminology, and it is described classically and quantumly, leading to difficulty in finding clarity.

Oh boy, you can say that again!
Title: Re: EM Drive Developments
Post by: Mulletron on 11/06/2014 08:57 pm
Well that specific impulse example from slide 43 is 40625 years. It melted down the quick and dirty delta V calculator I use from here: http://www.strout.net/info/science/delta-v/intro.html and gave me a delta V of 697,912,744,985.77 m/s. Acceleration of .544m/s^2. Velocity after 1 year 17,166,981 m/s. Whoa mama! Good thing there is a cosmic speed limit. Seems like something is really screwed up here. This is for chemical rockets. Anyway, I have to figure out how to get the thrust http://www.grc.nasa.gov/WWW/k-12/airplane/specimp.html numbers with the little info I have. If I can. I don't think this rocket equation stuff will work here. Any rocket scientists out there? The thrust part is confusing the crap out of me and I feel the answer is staring me right in the face. This QV stuff is confusing. Maybe I could take the measured thrust from the anomalous thrust paper and wrap it around and see if the impulse values on slide 43 jive. Anybody here especially gifted at math?

Anyway, that calculator isn't a good test because it is for chemical rockets. I used 10000kg before and 9460kg after with the an Isp of 1.282x10^12 seconds from the slide. The ship masses were from the example from appendix A here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf. Just having some fun. They don't mean anything. But I can wrap those numbers right back around and do some checking if I so desire.

But I did think of a possible way to solve the conservation of energy paradox someone brought up a few pages back. http://forum.nasaspaceflight.com/index.php?topic=29276.msg1283252#msg1283252

and here:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275281#msg1275281

Tomorrow I'll go back and read their comments again and actually break out my calculator and see what I can do here. Admittedly I have no idea how to deal with the neutrino mass.

We need to take into account that fusion reactors do lose mass by emitting massive neutrinos. So quantum thrusters space ships lose mass just like chemical rocket space ships do, in a different way.

So the example on slide 43 is for a Mach test article @2Mhz, can anyone adapt it to the Brady et al test article using the same rationale? He invokes QVPT in the latest test campaign report we've been tearing apart: http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

I mean, given the info we have from various sources (measured thrust/power/frequency) combined with the screenshot below, isn't that enough to reverse engineer this thing?
Title: Re: EM Drive Developments
Post by: frobnicat on 11/06/2014 10:55 pm
@Mulletron
Fusion reactors do lose mass by emitting "massive neutrinos" at relativistic speeds (and the rest mass part energy content is negligible compared to the emitted kinetic energy), but first principles first : they lose mass because they give energy. Giving energy E is losing at least mass E/c². Please do due diligence to the theoretical bounds before tackling more contingent aspects.

I would be glad to hear about a sensible solution to the "energy paradox" of propellantless propulsion schemes, because if one is to believe to constant thrust/power ratio of the order of 1N/kW (and this clearly appear to be the case when proponents put forward amazing mission profiles) then one surely has a better option than messing around with nuclear fuel (be it for fission or fusion) : use auxiliary thrusters on a fast rotating shaft, extract free unlimited energy, use free unlimited energy to power main thruster => infinite ISP rocket.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=619544;image)

For quantitative details and stability issues see
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255765#msg1255765
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255794#msg1255794

I don't know why people doing the mission profiles at 1N/kW are not advocating this obvious consequence of 1N/kW. Save maybe that "unlimited energy" would be immediately labelled crackpottery while "unlimited momentum" (with no intrinsic rest frame, making it as easy to push at the end of acceleration than at the beginning, which is not the case on a road) would have more chance to fly under the radars ?

Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/06/2014 11:41 pm
Quote
Signing "Very respectfully" a post that charges "Pretty much everything quoted above is either factually inaccurate, a logical fallacy, or a cognitive bias. The rest is weasel words. " does not make it respectful.

The subject being discussed in this thread is EM Drives and Spaceflight.

Well I am smart enough to recognize an agent provocateur on a forum whose mission is to create fear, uncertainty, and doubt. FUD. Because they have a conflict of interest (all things Woodward and his book). We've been here. I remember his treatment of Dr. M for example. So I calls em like I sees em. As I said, this is the last time I ftt. Giving in to the FUD creates distractions which is what they want. Back to the subject at hand, EMdrives and the science for or against them.

Thank you for your patience.

I'm sorry to burst your bubble, but the situation is just exactly as I described it.  QVF and E-M both fail the test of what makes real science, for exactly the reasons I've here explained.  QVF contradicts EEP and GR and for it to be true, these well established theories cannot be.    The E-M model fails simple conservation of momentum through a misunderstanding of what the concept of "group velocity" entails.  None of what I am saying is surprising, or a minority position--it is what the vast majority of physicists will tell you and in fact what they argue all across the web.

As to your misunderstandings about what virtual particles are, I suggest at least go read wiki.  You could not be more wrong and don't even seem to understand the issues.  Everything I wrote is true.  You just don't understand it nor agree with it.

And with that, yeah, we really need to be done and let the others do their thing.  If you stop posting the ridiculous nonsense about how these broken models obtain I promise not to continue to set you straight again and again.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/07/2014 01:17 am
Anybody here especially gifted at math?

You talkin' to me?  You can't be...

Quote from: Mulletron
Well that specific impulse example from slide 43 is 40625 years...

Just threw an eyeball over Sutton 7th, chapter 2, Definitions and Fundabmentals, where they define Isp.

That "Equivalent Mass" equation of Slide 43 is not at all an equivalent to chemical rocketry, that I can tell.

It is a bogus Isp.
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 11/07/2014 07:44 am
I think the main reason why intelligent people do make statements like the constant thrust/power ratio, has nothing to do with science or engineering and nobody here will like this reason, hence my reference to a book from Umberto Eco at the end of this post.

The reason some people at JSC did this is because they wanted to keep their job in Houston after the closure of the Space shuttle progam several years ago.

I was at the first two 100YSS conferences and dr White didn't make any bold statement, he just presented dr Alcubierre work with the added notions of "boost" and yet another bubble shape. Incidently he never mention more recent work like Natario's drive or Wisser's work. He seems as Paul Gilster put it: A shy guy who doesn't seek all that PR.

There were an incredible number of people in the room where he presented his work at first 100YSS and it seems he was the main reason DARPA created this conference. At least I understood it that way.
Those JSC people have also support from Texas politicians as well as from NASA's director: http://www.usnews.com/news/articles/2012/09/18/nasa-head-bolden-warp-speed-ahead

Once such powerful people are involved, there is only one possibility for JSC people: To continue quietly in this direction as long as needed until the ambient noise makes it disappear under the radar. Hence the scarcity of information about that warp drive/EMDrive stuff. 

One may find Eco's book having a lot of similarities with the present topic, especially the huge interest it gathered, if only you replace the Templar's treasure with propellantless propulsion : http://en.wikipedia.org/wiki/Foucault%27s_Pendulum (http://en.wikipedia.org/wiki/Foucault%27s_Pendulum)   ;D
Title: Re: EM Drive Developments
Post by: Mulletron on 11/07/2014 07:45 am
I think it is safe to say that a lot of work and a new way of thinking is needed in order to understand quantum rocket science.

This is bleeding edge stuff here. I'm not putting things to bed because I don't fully understand them yet. Since nobody is able to teach me about quantum rocket science, I have to teach myself. Unfortunately I don't have an unlimited IQ. I try, I try. I try to learn more. I have a love for learning new things and I'm a dreamer. While I lack in advanced mathematical ability beyond EE, I am an expert in systems thinking and logically solving problems.

I really really wish more people were on here with fresh perspective and experience. This group has shrunk to just a small number of the original contributors and I feel that just as I am hitting a wall, the group may be as well.

Now back to the books on nuclear powered paradoxes.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/07/2014 08:38 am
Concerning the "paradox" of conservation of energy. First I want to completely make sure I am addressing the problem, which is, folks are saying at some point the kinetic energy of the vehicle is exceeding the energy provided by the propulsion system...

Now I'm going to put controls in place:
1. I know that there is no such thing as a perpetual motion machine.
2. There is no such thing as an infinite store of energy device.

Now I'm going to build a model system:
1. The craft's mass is 100,000kg (50kg/kWe) (Middle of the road from the paper's 45 - 55 kg/kWe)
2. It has a 2MW fusion reactor on board.
3. The craft has a range of thrust to power ratios of 0.4 – 4.0 N/kWe

Specs above are from page 1 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf

Are the starting conditions good?
GO!
This is all going to boil down to Casimir momentum in the end.
I keep having to remind myself to not think of this like a reaction engine expelling a reaction mass. Instead I have to approach it from the standpoint of knowing the QV is doing the pushing.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/07/2014 12:28 pm
Umberto Eco

Two points for Gryffindor on the reference to Foucalt's Pendulum, and its literary, but accurate, comparison to propellantless propulsion.

I might add Hypatia's (http://en.wikipedia.org/wiki/Hypatia) observation:  "God has left shadows of truth in the depths of the heart in each of us, and it is a matter of bringing them forth."

The shadow of truth is that mankind has incomplete knowledge of physics.

Do carry on.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/07/2014 01:49 pm
I would be glad to hear about a sensible solution to the "energy paradox" of propellantless propulsion schemes, because if one is to believe to constant thrust/power ratio of the order of 1N/kW (and this clearly appear to be the case when proponents put forward amazing mission profiles) then one surely has a better option than messing around with nuclear fuel (be it for fission or fusion) : use auxiliary thrusters on a fast rotating shaft, extract free unlimited energy, use free unlimited energy to power main thruster => infinite ISP rocket. . .

I don't know why people doing the mission profiles at 1N/kW are not advocating this obvious consequence of 1N/kW. Save maybe that "unlimited energy" would be immediately labelled crackpottery while "unlimited momentum". . .
That is exactly why.  No one involved in this sort of work wants to be associated with the free energy crowd, even if what they're working on might be a way to harvest a new energy source.  they don't even want association with such things, in just the same way that all advanced propulsion seeks to distance itself completely from anyone bandying about the term "anti-gravity".  That term was ridiculed into uselessness back in the 50's and 60's so everyone avoids it like the plague.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/07/2014 02:05 pm
. . .However, we know that QFT is incomplete, requiring reconciliation with General Relativity. . .
It's interesting that one of the features of the Standard Model is that it does not include gravity and so is not background independent.  I think one of the most remarkable issues that rise out of the advanced propulsion field is Woodward's theory about the electron.  His electron model is the best I have ever seen and the only electron model that actually accounts for all the components and needs necessary to such a model.  It is the only electron modeI'm aware of that actually obtains as a workable model without stipulated qualifications and limitations, and it is easy to test.

If Woodward is right, he has gone an enormous way toward bringing QM and GR together finally and it should not be long before we have a theory of quantum gravity.  The electron model is that sweeping in its import.  Likewise too it would seem to explain dark energy.  You'd think people would want to check and see if electrons have a negative bare mass, as this is such a critical issue.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/07/2014 02:13 pm
I think the main reason why intelligent people do make statements like the constant thrust/power ratio, has nothing to do with science or engineering and nobody here will like this reason, hence my reference to a book from Umberto Eco at the end of this post.

The reason some people at JSC did this is because they wanted to keep their job in Houston after the closure of the Space shuttle progam several years ago.
I think you think these jobs are more fragile than they really are.  All of SLS is a jobs program.  It does't ever have to work.  It just needs to provide jobs.  Once it's complete, it should provide launch at about 10X the cost that Falcon does, so who in their right mind would use it?  No one.  It's a job's program.  Congress is completely willing to sidetrack all of NASA's human spaceflight funding in order to provide those jobs, so obviously the jobs are not fragile.

Besides, Dr. White came up with his QVF conjecture years before Shuttle was retired.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/07/2014 03:03 pm
It doesn't make sense to me to read that Woodward's electron model is"easy to test",  and then read that "if the model is correct", that all HSF would be transformed and enabled, and physics would change, and all that.

Shouldn't all this "easy"testing be done first?  And then all that transformation?
Title: Re: EM Drive Developments
Post by: frobnicat on 11/07/2014 05:00 pm
I would be glad to hear about a sensible solution to the "energy paradox" of propellantless propulsion schemes, because if one is to believe to constant thrust/power ratio of the order of 1N/kW (and this clearly appear to be the case when proponents put forward amazing mission profiles) then one surely has a better option than messing around with nuclear fuel (be it for fission or fusion) : use auxiliary thrusters on a fast rotating shaft, extract free unlimited energy, use free unlimited energy to power main thruster => infinite ISP rocket. . .

I don't know why people doing the mission profiles at 1N/kW are not advocating this obvious consequence of 1N/kW. Save maybe that "unlimited energy" would be immediately labelled crackpottery while "unlimited momentum". . .
That is exactly why.  No one involved in this sort of work wants to be associated with the free energy crowd, even if what they're working on might be a way to harvest a new energy source.  they don't even want association with such things, in just the same way that all advanced propulsion seeks to distance itself completely from anyone bandying about the term "anti-gravity".  That term was ridiculed into uselessness back in the 50's and 60's so everyone avoids it like the plague.

Okay, that makes sense (sociologically). But the problem is that, to have interesting mission profiles to "sell" they are necessarily having ships with more kinetic energy than was put out by generators, this is really central to the fact that propellantless missions get so interesting. Even if we had a straight asphalt road from Earth to Saturn and had wheels to push on it at many km/s, even with this "unlimited momentum" at our disposal all along the way, we would still be far from the propellentless mission profiles velocities. Quantitative estimations on request. So really, reaching such fast direct transits as Saturn in 260 days and deltaV of 200km/s (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf) (fig. 11) is not a problem of momentum, this is a problem of energy.

So in the end this is just "free energy in disguise". Think it's not good to have things in disguise in science, this is not sane. I'm ready to hear that those thrusters emit tachyons (negative energy). I'm ready to hear that quantum vacuum is like criss-crossing asphalt roads at all velocities and you can choose to push on the ones that are slow relative to you, taking at low energy cost (possibly 0) the intrinsic energy from those conveyor belts. That would be crazy but that would be all right : any idea without hidden secrets or "mysteries" or mystifications has a right to be expressed in science. Over unit energy gain issues are central to the functioning and understanding to propellantless schemes if they are to exist.

I'm not ready to hear about canards like the ones flying on Appendix A page 11 of above linked paper. More about that when I calm down : something really outrageous is going on in this Appendix. Second column. Read it well, read it again, check the maths.... this is both gross and subtle.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/07/2014 06:54 pm
Concerning the Appendix A in the latest retrieved by Rodal (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281559#msg1281559) public paper of B. Kent Joosten and Harold Human Outer Solar System Exploration via Q-Thruster Technology (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf) I said this was a spectacularly failed attempt at dealing with the problem of energy conservation for propellantless schemes.

After reading again, it appears to be an excellent exercise in deception. Whether it is self-deception (http://plato.stanford.edu/entries/self-deception/) (by haste, incompetence, lack of proof reading before cosigning) or voluntary deception (fraudulent) is left to the reader's opinion.

It starts by stating that, roughly, something fishy is going on with energy conservation.
<<When will the spacecraft with its given power level reach a state where the integral of the input power over a given time frame increase the kinetic energy of the spacecraft such that the change in kinetic energy is greater than the integral of power?>>
 
Good thing to ask, because at some point we have gained more energy than we have spent, and this would indeed be something to explain, somehow. From a conventional science standpoint, saying it like that is an understatement : this should be an absolute top priority if a theory or experimental result isn't to be thrashed. Appears from the following calculation that this is when deltaV = 2/Ts  that is twice the inverse of Ts the thrust/power ratio. Q-Thruster with a specific thrust Ts of 0.4 N/kWe <<A conservative Q-Thruster specific thrust assumption (0.4 N/kWe)>> will reach that deltaV at 2/.4e-3 = 5000 m/s = 5km/s. Note that the studied mission profiles go way beyong this deltaV, citing 100km/s for max velocity during transit to Saturn. So we were going to Saturn through the realm of "more gained energy than spent" for the most part.

A note on passing : this is just a factor two (we could as well ignore that little term and proceed) but it should be understood that, at velocity V relative to a given (more or less inertial) frame the over unit energy gain appears at V = 1/Ts. The 2 term comes when you consider the journey overall. From the standpoint of the rest frame from where the ship started, the ship is not gaining more energy than spent until half of the journey to 2/Ts, this first half part averages with the second half where the ship is always gaining more than spending. This second "phase" starts as soon as V>1/Ts. So the "problematic speed" is 2.5kms really.
Instantly_Recoverable_Mechanical_Power = Pout = V*Thrust = V*Ts*Pin   
Pout/Pin = V*Ts   Pout/Pin>1 => V*Ts>1 => V>1/Ts

Full frontal "more gained energy than spent" should be thrashed, or so it should be said to appear "scientifically correct". So the appendix goes on to say that
<<When this situation occurs, in order to ensure that the input energy is equal to the change in kinetic energy, the thrust to power performance will have to decrease over time.>>
I would rather say "performance will decrease over ever increasing speed".

All right then. Decrease by how much ? Does that hurt the mission profiles badly ? You bet it should ! This decrease factor is starting at Vc=1/Ts=2.5km/s and we want 100km/s. The "over unit power amplification factor" is proportional to V : Pout/Pin=V*Ts=V/Vc so we are betting on average (at 50km/s) on 20 times more efficiency than energy conservation decency should allow. Do we hear anything about that by the authors who have spent 10 pages on interplanetary go-fasts ? No. Silence about the consequences of that scientific decency requirement on the race-spaceships above.

Instead we hear that <<This scenario has an analog in the terrestrial realm when considering a turbine aircraft flight profile. At takeoff, the turbine aircraft has a very high thrust to power (hundreds of N/kW), but at cruise altitude, the thrust to power performance is much lower (1-10 N/kW). The following graph shows the curve with some highlighted data points for consideration.>>
I would add : take a road and a car and you have the same problem, it's proportionally harder to push on a "momentum medium" when having more velocity relative to this medium : power_required=V*Force.

So this is factually correct. This remark would make the subject advance if it served as an introduction as to "how are we supposed to define the rest frame of a momentum exchanging medium in interplanetary deep space ?". The later invocation of CMB rest frame is a joke as we will see. At this point I rather expected a wild but "crystal clear", or at least explicit speculation, that since vacuum defines no intrinsic rest frame (relativity...), we are "kind of always pushing it at 0 or near so relative speed" so that we have power_required=0*Force=0 or near so. A conveyor belt model for the vacuum. Don't know if that can be made theoretically sound, maybe Mulletron you are on this track when stating that we shouldn't consider pushing on but being pushed on.

Instead we have a graph with this Vc=1/Ts (or rather 2/Ts but really it should be 1/Ts) comparing Hall thruster at 0.056N/kWe, with a higher velocity around 30km/s ( beyond which ... what, it will gain more energy than spent ? We will see... ) than devices of higher Ts. That's basic rocket science that as Isp augments you have less mass penalty to reach higher deltaV but that Ts is lowered, things get less mass starved and more energy starved. On top left there would be the photon rocket. On bottom right there would be someone launching away a heavy bag while standing on a skateboard (10kg bag, 1m/s, that's 5J for 10kg m/s momentum or equivalently 2000N/kW, yes, that much, very power efficient, but very mass inefficient).

Obviously the great advantage of propellantless schemes with Ts>>1/c (photon rocket) would be to have better Ts than high Isp action/reaction, and yet having to throw out no mass like the better Ts schemes (chemical rockets) that get mass exhausted quickly.

Ok, so ?
Better is below this graph...

<<The change in kinetic energy as measured by the inertial observer at rest relative to the background radiation is the initial kinetic energy ... minus the final kinetic energy ... .>>

... will proceed after a deep yoga breathing session.
Title: Re: EM Drive Developments
Post by: Rodal on 11/07/2014 07:15 pm
.....
This was for one Shawyer's thrust vs power graph. I prefer to concentrate on Brady, as someone put it (you ? Aero ? Mulletron ?) it is better documented, and maybe of more reliable value. I don't completely give up on this "warm jet effect". Even if it seems unlikely it would have been gone unnoticed and gave results somehow in agreements between different labs, the alternatives are either as much hazardous (magnetic couplings) or more hard to swallow (axions anyone ?)

We don't even know from the experimenters the most basic geometric characteristics of their device. Who know (save them) how much they are tinkering with things before "it works", what kind of "secret recipe" procedures are followed and in which we could maybe see some confirmation or invalidation of such or such possible explanation. One thing stands out : the effect is hard to get at, and that's not because of ultra faint magnitude (µN when nN are "routinely" investigated with short range gravitation studies). So what makes it so hard to make it reproducible and reliable ? Driving a high Q at resonant frequency ? Mmm. Well. Maybe. Only maybe.

My latest derivation for the warm air jet hypothesis : F in function of microwave volumetric heating Pow and tau time constant of the rise/fall

F = Cf/rho * ((2*p*Tau)/V)^0.5 * (Pow/(C*T))^1.5

That is by using numerical values for almost constants ( 20°C ambient ... )
F = 1.41e-6 * 1/sqrt(V) * sqrt(Tau) * Pow^1.5

V=0.027m^3  Tau=2s  Pow=4W  yields F=97µN

But that needs tinkering until the leak area A is small enough (but not stoppered) to give high thrust, but big enough so that Tau is below some level (otherwise you see a ramp up). How much tinkering is going on ?
F = 9.7e-12 * Pow^2/A
Tau = 4.74e-11 * V*Pow/A^2

Intuitively I'm in favor of some electromagnetic explanation, but think this is still worth investigating.

Frobnicat, I haven't heard about your warm air propulsion model since your last message reproduced above.

I'm not clear as to what should be the forcing function as a function of time to input for the pendulum analysis, as per your model

For this

F = 1.41e-6 * 1/sqrt(V) * sqrt(Tau) * Pow^1.5

appears as a constant with tau = 2 seconds.

What is your forcing function for your warm air propulsion model as an explicit function of time?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/07/2014 07:40 pm
Second column. Read it well, read it again, check the maths.... this is both gross and subtle.

Me not get it.  Per that scenario in Column 2 on page 11, if ya go from 0km/sec to 1km/ sec, and your spacecraft drops from 10,000kg to 9460 kg, you end up at -4,730J J.

Your pragmatic inertial frame would be the galaxy, wouldn't it?  Let's say I'm at the Equator here on Eaarth, standing still.  Yet, I'm going a thousand miles an hour more or less.  I can't use that energy in any pragmatic fashion.  My rest frame is on the Equator, not in "absolute" space.

So what's the point of this "paradox"?

Why do they call it a "peculiar" velocity?  Why isn't it just a velocity relative to the CMB?
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 11/07/2014 07:43 pm
something really outrageous is going on in this Appendix. Second column. Read it well, read it again, check the maths.... this is both gross and subtle.
You mean what people call the "kinetic energy paradox"? That kinetic energy is proportional to the square of speed?
https://www.physicsforums.com/threads/kinetic-energy-and-frames-of-reference.534883/

It is what you already mention as a paradox as well as GoatGuy and it is also used in this linked paper.

What physicists say, is that one can't add up kinetic energy in different reference frames (nothing to do with relativity).

In my opinion every people using a metric like trust/power for several segments of the same travel, are doing exactly this mistake...adding kinetic energy in different reference frames
Title: Re: EM Drive Developments
Post by: frobnicat on 11/07/2014 08:48 pm
.....

Frobnicat, I haven't heard about your warm air propulsion model since your last message reproduced above.

I'm not clear as to what should be the forcing function as a function of time to input for the pendulum analysis, as per your model

For this

F = 1.41e-6 * 1/sqrt(V) * sqrt(Tau) * Pow^1.5

appears as a constant with tau = 2 seconds.

What is your forcing function for your warm air propulsion model as an explicit function of time?

This formula is for the thrust when a stationary phase (well, temporarily stationary since we are expelling air, at some point it would decrease, but this would be on the order of few minutes, will quantify all that) is reached when (heat driven) overpressure inside the cavity is stabilising relative to the leaked flow. At this stage the constant rate of increasing temperature gives a constant rate of air leak flow (before it loses too much density, few minutes later).

At the moment I don't have a satisfying F(t) expression, this amounts to formalising and solving a differential equation. At the moment I don't have this differential equation either  :)  but I will, and will post as soon as I have. So what I have at the moment is a simplified 2 phases model : first phase as if there is no leak and pressure is growing with temperature, second phase "stationary" when the pressure is high enough for the leak to have flow that compensate for the heating rate. Obviously in reality there would be a continuous transition from phase 1 asymptotically to phase 2. The phase 1 gives the Tau (this is approximative), the phase 2 gives the magnitude of the plateau (this is exact), but unfortunately this simplified model says nothing of the progression of thrust from 0 to F (at phase 1 we are assuming no leak yet).

Hope this is not a disappointment : this is still very preliminary. I do intend to keep on with the subject until a clear quantitative model gives F(t) in function of some explicit parameters. Also have to make it all again from scratch because I think that the hole in thin plate leak formula is not the right one, must go with Hagen-Poiseuille : surely the leaks would have small lateral dimensions relative to length, more like slit (say, between copper part and pcbs end plates). My guess is that it will change the exponent that's on Pow.

Have also to check microwave coupling with water vapor.

Have also to check the heat(t) at the inner surface of copper (might be higher/faster than expected) as a rise of temperature of 10° on 100cm^3 can give as much "oomph" as 5° on 200cm^3 or 1° on 1000cm^3, so lack of thermal conductivity of air might not be the relevant factor to set the typical Tau. + some heat equations...

Have also to finish to scrap the relevant data (and share)

Have also to, damn, forgot, oh yeah, try an explicit F(t) reconstruction from the said scraped data

Have also to rant about the latest propellantless propulsion paper at hand

So, a lot of work. And this is not all my usual area of expertise. Must learn, or relearn a lot.
Please be patient. Gimme 3 weeks or so.

Maybe if you are working on heat conduction aspects at the cavity's wall, this might help me if you have an idea of the Temp(t) of the inner skin. I know that copper is a very good thermal, conductor. The epoxy behind the (probably) much thinner copper of PCBs end plate not that much. The RF power is dissipated in the first µm depth skin. What gives instant temperature for the air molecules hitting the inner walls ? This could be a fast alternative to volumetric humid air heating.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/08/2014 12:01 am
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1285083#msg1285083   continued
@John & JP hope this will indirectly address your remarks, can answer more specifically if more clarifications needed.

The following reading is a little bit paranoid, and might see more intent than there really is...

So far, the offending Appendix A has stated that something fishy is going on about energy conservation with propellantless schemes. There should be some correction term depending on speed (relative to what is still unclear). Not stated : for energy conservation the correction would be severe, but we won't try to see how it would affect our fast trajectories (main body of paper). We are given a chart comparing various Thrust/Power ratios to see that from this point of view a Q-thruster is comparatively only an improvement on a Hall thruster, same ballpark just about one order of magnitude better. No crazy values, Hall thrusters are proven, and we are not pretending to be a million time better. What we are to think of the fact that on the vertical axis the Hall thruster has a higher "Delta-V Limit (absolute frames)" is left uncommented. For action/reaction scheme this "Delta-V limit" is of the same order as the ejection speed, and of the same order as the delta-V achievable through reasonable dry/wet mass ratios. For a propellentless scheme the dry/wet ratio is 1 for all practical purpose, so either the thrust/power don't care about "absolute frames" and this Delta-V limit is irrelevant (and energy is "tapped" from somewhere), or it does care about (for some unclear reason) and then at face value it means it is worse than Hall thruster for high delta V missions.

Instead of clarifications we have a mystification :
<<At this point, it is a useful exercise to explore this issue from a relativistic point of view, as it will uncover a paradox.>>

And then we will be shown that something fishy is going on also with a theoretically sound action/reaction system like a Hall thruster spacecraft. And the Appendix will conclude that
<<Although the example mission (with a Hall thruster) is clearly not an exotic mission and can easily be achieved in practice, the point of this paragraph is to identify that the paradox can be created for any spacecraft using conventional propulsion as well as advanced propulsion.>>

There we are : this is not a paradox or a problem with propellentless schemes, this is a paradox inherent to any spacecraft when energy is accounted for in an inertial frame fast enough relative to those typical delta Vs, because any of those has a Ts such that 1/Ts < high speeds, so surely any spacecraft can (apparently) provide more energy in kinetic form than is spent by the onboard generator. This is not a paradox with Q-thrusters, this is a paradox with relativity of velocities and how kinetic energy is accounted for in different inertial frame (we all know this is a messy business with all this square thing and non additivity...)

For instance, thought experiment, say we have a thruster at 0.05 N/kW that has a 1kW onboard generator, pushing at constant 100km/s relative to a device that receive mechanical energy (from this push) and converts it to electric energy. Then the mechanical energy received by this device is Force*speed = 0.05*100000=5kW. Surely this is enough raw mechanical energy to feed back 1kWe to the thruster ! Silly isn't it ? Note that : I didn't made any assumption on to what kind of thruster was used, the same calculations would hold for any thruster with 0.05N/kW thrust/power ratio.

We are left with this paradox, which plagues all spacecrafts when considered in some inertial frame fast enough. Surely there is some explanation everyone knows (so it's not worth talking about). Or maybe there is a deep mystery still lurking within Newtonian mechanics (so it's not worth talking about in an Appendix). But for sure Q-thruster is no fundamentally different from Hall thruster in that matter.

The peculiar velocity of our local  (I mean, you know, a real velocity) relative to CMB as a preferred natural cosmic rest frame is just a gizmo to add to the mental confusion. Are we to understand it is important to find a real velocity or a natural rest frame ? This is left to the uncertainty of the reader... Fact is : take any arbitrary inertial frame with velocity>100km/s aligned with spacecraft trajectory will do the same job. Such that from this "absolute frame" a spacecraft at rest in its local frame (on its launch pad) has already 100km/s before it adds another km/s on the cheap (from its point of view) to a staggering 101km/s, and yet it would in principle take more energy to go from 100 to 101 than to go from 0 to 1. Because of the square.
100² to 101² -> needs to add  201
0² to 1² -> needs to add 1
Wow, again, seems paradoxical, as this is the same "thing", just seen from a different way...

So we have this artefact of relativity and kinetic energy accountancy. Let's live with it and see how the quantum vacuum can be modelled as a plasma we can push on...

But not so fast ! Nature is not an accountant that can be fooled around. We are given a numerical example to be convinced. The numerical example is given for Hall thruster (the thing that is serious) and we will see, again, this paradox.

<<The initial mass is 10,000 kg, the final mass is 9,460 kg. The initial velocity is 371 km/s, and the final velocity is 372 km/s.>> <<The amount of energy provided by the power source over this time frame is 174 Gigajoules.>>


We are invited to do <<The change in kinetic energy as measured by the inertial observer at rest relative to the background radiation is the initial kinetic energy 1/2 mi vi² minus the final kinetic energy 1/2 mf vf² .>>

And see that the result is <<The change in kinetic energy is 33,649 Gigajoules, which is two orders of magnitude larger than the energy provided by the power system.>>

Do the math, see for yourself, that works.

Except for one point : since when do you measure a change by subtracting a final amount from an initial amount ?

Proper handling shows that we are not gaining but losing : EKf-EKi = - 33649 GJ   (minus)
How comes ? Because we are losing mass ! Hall thruster is an action/reaction scheme.
The dry mass fraction of  9460kg has more kinetic energy at 372km/s than at 371km/s
But the wet mass at 371km/s as more kinetic energy than the dry mass at 372km/s

So far we are nowhere near gaining more net energy than spent.
If we are to take into account the kinetic energy of the expelled mass of 540kg with Isp 1838, that is ejection velocity around 18km/s, from 371.5 on average, speed of expelled mass drifting behind is 353.5km/s :

Total kinetic energy initial
.5*10000*371000²
= 688205000000000

Total kinetic energy final
.5*9460*372000² + .5*540*353500²
=654556320000000 + 33739807500000
= 688296127500000

Change in kinetic energy :
final - initial
= + 91127500000 = 91.1 GJ

So we gained 91.1 GJ while <<the power source over this time frame is 174 Gigajoules.>>

There is nothing fishy going on with a Hall thruster.


On the other hand, with a Q-thruster of same Ts=0.056N/kWe which is not expelling mass, for roughly the same result, 10000kg*1000m/s=1e7 momentum will use E=1e7/Ts=178 Gigajoules (a bit more than Hall thruster since the spacecraft doesn't get lighter on the way) from onboard power source.

Total kinetic energy initial
.5*10000*371000²
= 688205000000000

Total kinetic energy final
.5*10000*372000²
=691920000000000

Change in kinetic energy :
final - initial
=3710 GJ

About 20 times more than spent.
There is something fishy going on with a Q thruster.



The same remarks would apply for any arbitrary rest frame : the sane system (Hall thruster) will never exhibit more kinetic energy change (final - initial) than spent energy.
The pathological system (Q-thruster) will sometimes exhibit more kinetic energy change than spent energy, sometimes less, depending on arbitrary frame from where kinetic energy is measured.
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/08/2014 02:40 am
And something I have been thinking about lately that fits in with Frobnicats last post: bouncing photons, and a odd version of the photon rocket.

As I understand it:

1) Photons have only one speed - lightspeed.  Lightspeed, however, can vary depending on the media the light is passing through.

2) Photons have enough inertial mass, at least, to make a solar sail work - something demonstrated by NASA.  Photons hit solar sail, pushing the solar sail and whatever its attached to. 

3) Hence, you take a real heavy duty flashlight to 'deep space' and turn it on, the escaping photons would generate thrust.  Not much thrust, but thrust.

4) And photons are surprisingly durable little critters.  Estimates I have seen posted in this thread claim a photon can bounce for 40,000 - 50,000 times, before being absorbed .

So...with the above in mind:

Visualize a long tube, maybe a meter wide by two kilometers long, sealed at one end, open at the other.  Around the outside of the open end, you have six or eight high power lasers arranged in a circle, aimed inside the tube at a sharp angle.  The tubes interior is set up so these laser beams bounce off the interior in very precise directions.  Basically, the beams bounce about every half meter.  And just to be clear, the lasers are acting like photon rockets.

So...

1) When the lasers first fire, the initial thrust is backward.

2) With each bounce, the photons in each beam convey motion that is both 'sideways' and 'forward.'  And the photon strikes with the same force each time. 

3) Multiply that by 40,000 plus bounces, and the whole cylinder is either accelerating at a fairly decent clip, or conservation of energy is being violated.

4) Oh, and the last bounce, again requiring careful angles, is off the sealed end of the cylinder, directing the photons in a beam right down the middle of the tube.

Now, granted, you'd need a serious power plant to power this thing, and you'd probably want to tie a few dozen of them together in a frame of some sort, but it should get you to near relativistic speeds for far less energy cost than a rocket.

Unless I'm missing something critical.

Ok, time to post the explanations and cute videos showing how deep of a crater I dug this time...







Title: Re: EM Drive Developments
Post by: aceshigh on 11/08/2014 05:31 am
hmmm... don´t the photons lose energy with each bounce? Yes, you will say that they remain at light speed after each bounce... which is true... but maybe in there we see the weird duality of light as particle and wave? If you see each photon alone, they won´t lose energy, but considering the whole light wave, it will?
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/08/2014 07:24 am
Quote
hmmm... don´t the photons lose energy with each bounce? Yes, you will say that they remain at light speed after each bounce... which is true... but maybe in there we see the weird duality of light as particle and wave? If you see each photon alone, they won´t lose energy, but considering the whole light wave, it will?

That is the part of this that has me baffled.  A photon cannot loose momentum (inertia) and still be a photon, so it has to keep traveling at light speed.  Which means my reasoning should be right - each photon should transfer the same amount of kinetic energy with each bounce. And lasers are a proposed means of providing photons for solar sail propulsion.  Yet, if my reasoning is right, we are getting into free energy territory, which means this cannot be right.


I can see a lot of photons getting 'stopped' in the course of all these bounces, but many (half?) should make the full trip, and that is still one hell of a lot of kinetic energy. 

Maybe Doctor Rodal or Mulletron can point out the glaringly obvious flaw here.
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 11/08/2014 07:51 am
...
more energy to go from 100 to 101 than to go from 0 to 1. Because of the square.
100² to 101² -> needs to add  201
0² to 1² -> needs to add 1
Wow, again, seems paradoxical, as this is the same "thing", just seen from a different way...
Please, please Frobnicat, you are going too fast for me.
- Nobody should add kinetic energy in different reference frames. That's not a paradox, that's plain and classical mechanics. A consequence is that nobody should use trust/power ratio.
- There is no ongoing conspiracy at NASA, only usual business in an agency that consumes 2 billions each years and wants to survive. To survive it needs people support.
People enjoy Startrek stuff (I am not joking, I really mean it). So NASA (and Discovery TV, and a handful of SF authors and some NASA consultants) feed people with the stuff they ask. That's a profitable business.
If one want serious science papers, there are many reputable sources. Science journals mostly, not conference papers, not pre-print servers, not self cited papers.
I know it may sound harsh, I don't want to be harsh, sorry for my lack of writing gift. This whole thread is going too far, intelligent people see artifacts and meaning where there is none. I am very sorry about that.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/08/2014 08:30 am
@ThinkerX The energy of light is proportional to the frequency. Higher frequency, higher energy photons. If some of that energy is given up to something else, the frequency is lower.

@JPLeRouzic et al. I called bull on the "paradox" from appendix A here (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf) a while ago due to a plethora of reasons. See my comments on "false paradox." Page 192. Confusing reference frames was just one of many problems with appendix A. The rest was just plain bad math.

On the subject on why there is so little data on Q thrusters from Nasa. I don't sense an underhanded scheme going on there for job security or something bad like that. I think either they don't really know why it works and don't want to ruin their reputation by putting out a paper on the theory without making sure it is correct OR they simply are holding on to the data because they simply choose to do so.

Break:
Still there are questions concerning conservation of energy relating to invoking the quantum vacuum to explain thrust from @Frobnicat and @Ron Stahl which need to be addressed. I'm not sure if there is enough info to really address those concerns. I spent all day trying to figure this out and I simply don't have enough info about the momentum of the QV. Simple as that. If there are massive particles appearing and disappearing there in and they are in motion, then they must have momentum during their brief existence.

The issue of the Nasa conjectured Q-thruster enabled fantastic mission profiles is another issue that needs serious attention, as enlightened by @Frobnicat.

I can tell you that I know there is no such thing as a free energy device so I'm chalking those concerns up as valid yet premature simply because we don't even understand Quantum Rocket Science yet. The QV is not well understood.

The fact that EMdrive demonstates that you must put energy in in order to get something out supports that we're not dealing with hocus pocus here.

Edited to add full names.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/08/2014 09:53 am
...
more energy to go from 100 to 101 than to go from 0 to 1. Because of the square.
100² to 101² -> needs to add  201
0² to 1² -> needs to add 1
Wow, again, seems paradoxical, as this is the same "thing", just seen from a different way...
Please, please Frobnicat, you are going too fast for me.
- Nobody should add kinetic energy in different reference frames. That's not a paradox, that's plain and classical mechanics. A consequence is that nobody should use trust/power ratio.

This is not what is going on. What is going on is choosing a given arbitrary inertial frame, and working from there. I know there is no paradox. Anybody can use thrust/power ratio in a given arbitrary inertial frame and it will give correct results if the system is losing enough mass in the process. Thrust/power is ok because the power is from the onboard generator, and thrust has an effect of the variable of interest (velocity) that is linear.
Onboard generator -> given power OK  (don't depend on frame)
given power -> given Thrust (from Ts) OK (don't depend on frame)
given Thrust -> given acceleration OK   a = F / m  ( don't depend on frame)
acceleration -> (Vf - Vi)/delta_t   OK ( don't depend on frame)
For the last : Vf and Vi magnitudes do depend on frame, but the difference Vf-Vi dont.

So, this is not a problem with using Thrust/Power

The problem in Appendix A is that there is an error, a huge error, when calculating the Hall thruster in the frame of CMB : the change in kinetic energy is given by initial state minus final state. Which yields a value higher than the spent onboard energy. BUT but but, the change in kinetic energy should be the other way around, final state minus initial !!!

Which would yield a negative value, that is obviously less than spent energy. So their calculation is plain wrong, so is their conclusion that a Hall thruster is as much paradoxical as a Q thruster. The calculation done properly show quite the opposite : the Hall thruster has a perfectly sane energetic behaviour in whatever frame, even when using Thrust/Power as a mean to know its acceleration, and the same calculation for Q-thruster (not done in the paper) show it has a pathological behaviour in some frame, giving more kinetic energy than energy spent.


This is as simple as that, this is gross (playing on a sign convention) and subtle (relativity, even Newtonian, has interpretation subtleties, and nobody really like to check sign conventions). But in money terms maybe it's more clear : doing a financial operation where a cash investment of 1000$ (spent energy) makes that your portfolio values (kinetic energy) goes from 100000$ before to 10000$ after you would not say that the change in portfolio value is before-after 100000-10000=90000 and you had 90 over unit gain factor. You would do  after-before and see that you have a change of -90000 and lost 90 times the cash invested : this is not really over unit gain. The difference probably fell into someone else pocket. Financial system is not exactly conservative but see the point : change is not initial-final, it's final-initial, this is gross, and turns the conclusion on it's head.

Quote
- There is no ongoing conspiracy at NASA, only usual business in an agency that consumes 2 billions each years and wants to survive. To survive it needs people support.
People enjoy Startrek stuff (I am not joking, I really mean it). So NASA (and Discovery TV, and a handful of SF authors and some NASA consultants) feed people with the stuff they ask. That's a profitable business.

Yeah, I do enjoy Startrek a lot too. But when you see people signing under NASA stamp EM simulations showing net asymmetry in momentum of photons bouncing inside cavity, while Greg Egan a "hard" science fiction author does a perfect job at showing how EM waves bouncing in an asymmetric cavity yields a perfectly symmetric result of 0 net thrust, then you see there is a problem. I would be tempted to give more credits to wild speculation of scifi authors than to scientists working on propellentless schemes. We'd better see how to fix the polarized negative power coupling axis on the Falcon Millenium...

I'd rather stick with working on more concrete hypothesis for explaining the apparent experimental results, but when I saw this Appendix A I couldn't keep silence : there is a huge error in this paper, and there is a completely wrong conclusion drawn from this huge error. This would need at least a public acknowledgement and proper correction from the authors if they are serious about doing science.

Quote
If one want serious science papers, there are many reputable sources. Science journals mostly, not conference papers, not pre-print servers, not self cited papers.
I know it may sound harsh, I don't want to be harsh, sorry for my lack of writing gift. This whole thread is going too far, intelligent people see artifacts and meaning where there is none. I am very sorry about that.

I am sorry that people working on those advanced concepts are doing such mistakes and bad methodology. There should be room for speculations and bold experiments. Appears there is no "serious science paper" dealing with energy conservation for propellentless schemes (is there ?). We would be very happy to see more than conference papers, pre-prints, self cited papers, on the subject. Appears the public production of people involved is kept at that level.

So what do we do ? Leave the subject altogether ? Don't tempt me.
If we want to keep on discussing propositions of the proponents then we are left with no options but to read and comment publications of that level.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/08/2014 11:25 am
To really get to the bottom of the issue of "paradoxical mission profiles" (if they are or not is not unanimous.... in Nasa's defense in both the Brady et al paper and the Human Outer Solar System Exploration via Q-Thruster Technology paper, they play it safe with 0.4 N/kWe) and similar questions concerning Q thrusters, I really need to understand the most fundamental part of the issue at hand. That is the behavior of Casimir momentum:

http://arxiv.org/pdf/1304.6767v2.pdf

Similar subject as what I've posted before, same authors. Different subject.



Break.
Did I mention that a conference paper isn't a venue for peer review? Neither is the Human Outer Solar System Exploration via Q-Thruster Technology paper. They can pretty much say whatever they want in those things. They are a tool for drumming up interest. That's about it.

We can get all excited about things if an actual legit paper ever gets released supporting Q thruster theory. Perhaps someone here can author one, given what we may have uncovered here on this forum.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/08/2014 12:37 pm
To really get to the bottom of the issue of "paradoxical mission profiles" (if they are or not is not unanimous.... in Nasa's defense in both the Brady et al paper and the Human Outer Solar System Exploration via Q-Thruster Technology paper, they play it safe with 0.4 N/kWe) ...

I don't know if having more (properly accounted) kinetic energy than (properly accounted) spent energy is paradoxical but think there is near unanimity that this is not scientifically correct. This wide unanimous crowd is simply unanimously ignoring those research.

I can't let say that 0.4 N/kWe is "playing safe" : first a convincing reproducible experiment showing such stable level for a long duration (say, an hour) is still unreported that I know of, second and most importantly anything above .00000333 N/kW (photon rocket) is not safe as far as energy conservation is concerned.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/08/2014 12:51 pm
To really get to the bottom of the issue of "paradoxical mission profiles" (if they are or not is not unanimous.... in Nasa's defense in both the Brady et al paper and the Human Outer Solar System Exploration via Q-Thruster Technology paper, they play it safe with 0.4 N/kWe) ...

I don't know if having more (properly accounted) kinetic energy than (properly accounted) spent energy is paradoxical but think there is near unanimity that this is not scientifically correct. This wide unanimous crowd is simply unanimously ignoring those research.

I can't let say that 0.4 N/kWe is "playing safe" : first a convincing reproducible experiment showing such stable level for a long duration (say, an hour) is still unreported that I know of, second and most importantly anything above .00000333 N/kW (photon rocket) is not safe as far as energy conservation is concerned.

Sep'n this ain't no photon rocket. It is more like a quantum sail IMHO.

See my colorful comments on page 195.....for why I think it works like a quantum sail. You have to apply power to this EMdrive (quantum sail) for it to work. The subject of all those papers I keep posting on here since page 126 deal with transferring momentum from the QV to matter.

It took me 69 pages for that to finally sink in.
Title: Re: EM Drive Developments
Post by: JPLeRouzic on 11/08/2014 01:11 pm
...
more energy to go from 100 to 101 than to go from 0 to 1. Because of the square.
100² to 101² -> needs to add  201
0² to 1² -> needs to add 1
Wow, again, seems paradoxical, as this is the same "thing", just seen from a different way...
Please, please Frobnicat, you are going too fast for me.
- Nobody should add kinetic energy in different reference frames. That's not a paradox, that's plain and classical mechanics. A consequence is that nobody should use trust/power ratio.
...

The problem in Appendix A is that there is an error, a huge error, when calculating the Hall thruster in the frame of CMB : the change in kinetic energy is given by initial state minus final state. Which yields a value higher than the spent onboard energy. BUT but but, the change in kinetic energy should be the other way around, final state minus initial !!!

Which would yield a negative value, that is obviously less than spent energy. So their calculation is plain wrong, ...


...
* I wrote about what you stated at 12:01 AM in the server time, it is still quoted above. Your last post (09:53 AM) is about a different issue.
* Unfortunately for me physics is not my professional domain, so I don't understand your reasoning (09:53 AM) of a craft that has a speed increasing and a decreasing kinetic energy. (Ef - Ei) < 0 => Ef < Ei.
* Anyway I still think the fact kinetic energy can't be added or substracted on different reference frames, applies to what you say in your last point (end-start vs start-end)...The rocket has different speeds at start and end points, so it's different inertial frames.
* If you feel they made a mistake, maybe the best is to write to the paper authors...

(edited because of typos)
Title: Re: EM Drive Developments
Post by: Mulletron on 11/08/2014 01:15 pm
@JPLeRouzic. Look at my comments on page 192 about the false paradox. It is as simple as this. A chemical rocket/ion thruster/whatever, that is gaining speed can still lose kinetic energy because it is losing mass by losing fuel. I showed it mathematically. I actually did some math around here.

There is no perfectly efficient thruster out there.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/08/2014 02:27 pm
Now, granted, you'd need a serious power plant to power this thing, and you'd probably want to tie a few dozen of them together in a frame of some sort, but it should get you to near relativistic speeds for far less energy cost than a rocket.

Unless I'm missing something critical.

I think you are missing somethhing critical.  They call it mass.

Note that solar sails are very big, and that solar satellites are very small and light.

All of your lazers and power plants are very massive.  The device will hardly move.  However, place your lazers on a handy airless planet, and aim them at a solar sail, and you can get the thing to move.

And Just review the cute video I posted a few pages ago.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/08/2014 02:37 pm
But in money terms maybe it's more clear : doing a financial operation where a cash investment of 1000$ (spent energy) makes that your portfolio values (kinetic energy) goes from 100000$ before to 10000$ after you would not say that the change in portfolio value is before-after 100000-10000=90000 and you had 90 over unit gain factor. You would do  after-before and see that you have a change of -90000 and lost 90 times the cash invested : this is not really over unit gain.

Obviously, you don't know how building contractors work.  Let's say a contractor bids a house at $100,000, expecting to make a 20% profit, or $20,000.  Suppose also that his costs were higher than estimated and he only makes a 15% profit, or $15,000.  He tells his next customer that he lost $5,000 on the previous house, and that the next one will have to cost $105,000, to properly cover the cost of materials.

Happens all the time.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/08/2014 02:42 pm
If you feel they made a mistake, maybe the best is to write to the paper authors...

That would be a waste of time.  They will not engage the bonifide math whizzes on this thread.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/08/2014 02:59 pm
...
* I wrote about what you stated at 12:01 AM in the server time, it is still quoted above. Your last post (09:53 AM) is about a different issue.
* Unfortunately for me physics is not my professional domain, so I don't understand your reasoning (09:53 AM) of a craft that has a speed increasing and a decreasing kinetic energy. (Ef - Ei) < 0 => Ef < Ei.

not sure I understand the time stamps issues ...

As Mulletron just said, and as my calculations show also in detail, this is about the action/reaction (classical, ion thruster or chemical) implies that the spacecraft mass is decreasing. So that in some frame it appears the kinetic energy decreases. For instance take a wandering big asteroid as an arbitrary inertial frame reference. Consider a 1 ton spacecraft that has a velocity 10km/s relative to it. Would it be to smash into it, the impact would release .5*1000*10000^2 = 50 billion Joules. Now consider the same spacecraft after it has used half its mass in propellent (chemical burn, relatively low Isp) to get 2km/s delta V. Velocity relative to asteroid is now 12km/s. The 500kg dry mass (mission payload) has obviously gained kinetic energy (relative to asteroid). But if it were to smash now, it would release only .5*500*12000^2 = 36 billion Joules. Less kinetic energy because the first crash implied a lower velocity but a much higher mass. There is no paradox. There is no playing between different frames of reference, there is only one frame in this example, that of the asteroid. A frame of reference is the frame in which you measure the velocities. This is not a matter of having different velocities, many velocities measured relative to the same inertial body is still one and only one reference frame.

Quote
* Anyway I still think the fact kinetic energy can't be added or substracted on different reference frames, applies to what you say in your last point (end-start vs start-end)...The rocket has different speeds at start and end points, so it's different inertial frames.

Don't want to be rude but : no.
As example above shows, different speeds is not different frames. The different speeds are measure relative to one and only one inertial body. I'm not trying to confuse or mystify you, ask any scientist/engineer/teacher who knows to handle Newtonian mechanics routinely, there is consensus, this is perfectly understood and leaves place to no ambiguity. Take "smashing into the big inertial body of reference" as the "proof of concepts" that would make things real and not just a play of words and numbers, that is (could be) very real. The impact would make less bang for 500kg at 12km/s than 1000kg at 10km/s.

Quote
* If you feel they made a mistake, maybe the best is to write to the paper authors...

Yes maybe, I'm considering that. Thing is, I'm just an anonymous poster, part time amateur scientist interested in the subject but with no credit in the domain. They should know better, their peers should know better. I'm the last person that should signal that to them.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/08/2014 03:13 pm
@Frobnicat et al.

Please excuse my excursion to the Oracle, but her answers on this subject will make things as right as rain:

http://en.wikipedia.org/wiki/Space_travel_using_constant_acceleration

"It gets harder to push a ship faster as it gets closer to the speed of light

This is a half-myth because it depends on the frame of reference. It is true for those watching from the planetary reference frame. For those experiencing the journey (in the ship's reference frame) it is not true. For both the planetary frame and the ship's reference frame, the ship will change speed in a Newtonian way—push it a little and it speeds up a little, push it a lot and it speeds up a lot. However, in the planetary frame the ship will appear to be gaining mass due to its high kinetic energy, and the Mass-energy equivalence principle. Should the engines be giving a constant thrust, this will result in progressively smaller acceleration due to the higher mass it is required to accelerate.

From the ship's frame, the acceleration would continue at the same rate. However, due to Lorentz contraction, the galaxy around the ship would appear to become squashed in the direction of travel, and a destination many light years away would appear to become much closer. Traveling to this destination at sub-luminal speeds would become practical for the onboard travellers. Ultimately, from the ship's frame, it would be possible to reach anywhere in the visible universe, before the ship has time to accelerate to light speed."

In the end, we're not going to violate any conservation laws. We're limited by the finite amount of energy we can carry within any spacecraft. We're also limited by SR.

Appendix A in that paper failed mathematically, scientifically by adding together reference frames, and by using a false analogy with Hall thrusters. Every way you look at it, it is just plain wrong.

The further concerns brought up here in this forum apply to photon rockets, which we aren't dealing with here. EMdrive isn't a photon rocket.

The final concern about QV derived thrust is still a valid concern. I of all people acknowledge this. And I am championing the QV approach.

As long as nobody calculates a specific impulse of infinity, we're safe.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/08/2014 06:44 pm
It doesn't make sense to me to read that Woodward's electron model is"easy to test",  and then read that "if the model is correct", that all HSF would be transformed and enabled, and physics would change, and all that.

Shouldn't all this "easy"testing be done first?  And then all that transformation?
I agree--it doesn't make sense.  Woodward's work gives validation, but what one needs is replication.  Since there is no money out there for this, we have the situation we have.  The ZPFers are handling all the money, such as from DARPA.  That's what I'd like to change if I can find a PI for a grant.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/08/2014 06:51 pm
So in the end this is just "free energy in disguise". Think it's not good to have things in disguise in science, this is not sane. I'm ready to hear that those thrusters emit tachyons (negative energy). I'm ready to hear that quantum vacuum is like criss-crossing asphalt roads at all velocities and you can choose to push on the ones that are slow relative to you, taking at low energy cost (possibly 0) the intrinsic energy from those conveyor belts. That would be crazy but that would be all right : any idea without hidden secrets or "mysteries" or mystifications has a right to be expressed in science. . .
Well you've hit on another of my pet peeves.  Neither QVM nor ZPF has an explanation that preserves conservation.  This is why it is specifically called a conservation violation in the Eagleworks literature.  Woodward has taken the opposite tack--he claims that since such a high thrust efficiency device needs to generate temporary negative mass, conservation is preserved.  First of all, the energy and momentum is accounted for by the enhanced entropy of the entire system--the universe--and secondly that mass has negative inertia, so when you sum the local system, you don't get the obvious violation.  This is at least an attempt to balance the books and something the QV folks can't do.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/08/2014 07:00 pm
something really outrageous is going on in this Appendix. Second column. Read it well, read it again, check the maths.... this is both gross and subtle.
You mean what people call the "kinetic energy paradox"? That kinetic energy is proportional to the square of speed?
https://www.physicsforums.com/threads/kinetic-energy-and-frames-of-reference.534883/

It is what you already mention as a paradox as well as GoatGuy and it is also used in this linked paper.

What physicists say, is that one can't add up kinetic energy in different reference frames (nothing to do with relativity).

In my opinion every people using a metric like trust/power for several segments of the same travel, are doing exactly this mistake...adding kinetic energy in different reference frames
According to Woodward, this entire method is flawed and the correct way to do the cal is to "sum the instantaneous frames of rest" which is to say, use the tools of GR.  He handled this objection in some detail a couple years ago and since that time, one of the guys over at T-P managed to do the same calc without the GR tools and get the same answer, but this is not to say one ought expect to use the wrong tools and get the right answers.  This kind of calc needs to use GR since the frame the thruster is in is accelerating and is non-inertial.  And yes, you are completely correct that the trouble comes when you " add up kinetic energy in different reference frames" however, GR does include the tools to do this properly.  This requires a transform that is well beyond my training.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/08/2014 07:08 pm
There we are : this is not a paradox or a problem with propellentless schemes, this is a paradox inherent to any spacecraft when energy is accounted for in an inertial frame fast enough relative to those typical delta Vs, because any of those has a Ts such that 1/Ts < high speeds, so surely any spacecraft can (apparently) provide more energy in kinetic form than is spent by the onboard generator. This is not a paradox with Q-thrusters, this is a paradox with relativity of velocities and how kinetic energy is accounted for in different inertial frame (we all know this is a messy business with all this square thing and non additivity...)
So far as I'm aware, this above is completely correct.  On his reading list, Woodward demonstrated this seeming violation occurs with any sort of thruster on a swing arm.  And as I said, his solution was to "sum the instantaneous frames of rest" which is some sort of transform used in GR.  It was in fact his demonstration that this seeming violation occurs with any thruster that sold me we need a difference in kind to get this kind of performance, and the difference is of course that mass with negative inertia makes an unusual contribution, and can account for the trouble.

See Forward's analysis here:  http://en.wikipedia.org/wiki/Negative_mass
Title: Re: EM Drive Developments
Post by: 93143 on 11/08/2014 08:09 pm
On his reading list, Woodward demonstrated this seeming violation occurs with any sort of thruster on a swing arm.

And I demonstrated here (http://talk-polywell.org/bb/viewtopic.php?f=10&t=2215&start=1995#p103729) that that only happens when you fail to properly account for the energy of the propellant - ie: you draw the box too small and fail to close the system.

one of the guys over at T-P managed to do the same calc without the GR tools and get the same answer, but this is not to say one ought expect to use the wrong tools and get the right answers.

You do not need GR to get the right answer in this case.  I'm not sure what exactly Woodward was doing, but either he was wrong or you misunderstood him.  (From your description, I suspect the latter.)  The energies and velocities are low, the distances involved are small, and space can be assumed to be approximately flat.  Really it's no more than a first-year mechanics problem, as I clearly showed at the above link.

You've seen my qualifications, so you should know I live and breathe Newtonian mechanics, and I can easily tell when a model problem is outside its domain.  This one isn't.

Furthermore, if you attempt to use GR to get conservation without accounting for the energy of the propellant as I do above, you will fail in the general case, and for exactly the same reason: because what you have is an open system.  It isn't a matter of my method being 'alternate'; it's a matter of my method being right.  Doing the problem in GR would be more complicated, and would account for cosmically large, arbitrarily dense components and relativistic velocities, but without accounting for the energy of the propellant it would still end up wrong.

That's why I don't like the "recycled propellant" description of a Mach-effect thruster.  It draws the box too small, and you still ultimately get a conservation violation.  You need the interaction with the "far-off active mass" to make the idea work.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/08/2014 08:33 pm
There we are : this is not a paradox or a problem with propellentless schemes, this is a paradox inherent to any spacecraft when energy is accounted for in an inertial frame fast enough relative to those typical delta Vs, because any of those has a Ts such that 1/Ts < high speeds, so surely any spacecraft can (apparently) provide more energy in kinetic form than is spent by the onboard generator. This is not a paradox with Q-thrusters, this is a paradox with relativity of velocities and how kinetic energy is accounted for in different inertial frame (we all know this is a messy business with all this square thing and non additivity...)
So far as I'm aware, this above is completely correct.  On his reading list, Woodward demonstrated this seeming violation occurs with any sort of thruster on a swing arm.  And as I said, his solution was to "sum the instantaneous frames of rest" which is some sort of transform used in GR.  It was in fact his demonstration that this seeming violation occurs with any thruster that sold me we need a difference in kind to get this kind of performance, and the difference is of course that mass with negative inertia makes an unusual contribution, and can account for the trouble.

See Forward's analysis here:  http://en.wikipedia.org/wiki/Negative_mass

By reading again my irritated post you are quoting an extract from I realise it might be not clear ( to people giving credits to maverick science thinking ) when I speak for what I understand the authors are saying and when I speak for what a "classical scientist" ( let's say this is my case ) would say, sorry for that.

The bold statement above you are quoting was ironic. This is what I understand the authors are implying  and I think it is completely bogus.

It doesn't take GR and erudite summations in "the instantaneous frames of rest" to understand that there is no seeming violation of conservation from whatever known proven thrusting device (be it a car on road, a chemical rocket, a ion driven probe, a photon rocket) whatever is the one arbitrary inertial frame of reference used to measure speed and account kinetic energy for, be it in Newtonian mechanics for small speeds, or at any speeds for special relativity. Million people that are studying and designing the cars, rockets, washing machines, guns, planes and all other devices that work on Newtonian mechanics can tell that : there is nothing paradoxical, not even a hint at, not anything a little mysterious like renormalization techniques in QFT, not anything that would make interpretation hard or ambiguous.

GR is for dancing around singularities or ultra-precise trajectories measurements. It isn't required to show that a .4N/kW ion thruster in deep space does not violate or seem to violate anything by 20 times. Well understood Newtonian mechanics is enough for that. While a propellantless thruster does clearly seem to violate energy conservation by 20 times or by 2000000000 times depending on the arbitrary inertial reference frame. Now if you say that a propellantless thruster needs GR to be shown conservative, in a more complex way, precisely because it shows such ill defined behaviour in Newtonian mechanics and SR, I'm listening

The only "classical case" I'm aware where such a well known proven device would show such seeming violation relative to inertial frame in SR is when the relative speed to rest frame is above c. That is we have an already above c spacecraft, thrusting even more on classical particle ejection. Reciprocally a spacecraft below c thrusting on tachyons (above c particles) would show such apparent violation (but no violation when taking properly into account the emitted negative energy).

I'm ready to hear about that, not gibberish about seeming violations of classical mechanics because classical mechanics show no such appearance of violation when dealing with classical devices, and this is just mystification to say that they do.

If you or anyone think to have seen a "seeming violation" in Newtonian mechanics or SR, then please put the case in clear terms (what is violating what relative to what) and it will be my pleasure to either show that there is an error in the calculation, or that there is no violation, real nor apparent. If someone is trying to sell you a seeming appearance of violation from a classical device (ion thruster, washing machine...) then, I tell you, a million people doing rockets and planes tell you : consider that he is trying to mystify you (maybe he is himself mystified, or self-mystified).

oops, I see 93143 answered faster. Glad to hear someone of the million people...
Title: Re: EM Drive Developments
Post by: Mulletron on 11/08/2014 08:52 pm
http://ptp.oxfordjournals.org/content/119/3/351.full.pdf+html

Peculiar indeed.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/08/2014 09:22 pm
You know......All of this is starting to come full circle. All this talk about magnetochiral this, and diamagnetic QED vacuum blahbidibla that, angular momentum, spin, helicity talk (magnetism is due to electron spin, simply put) is supporting why the TE mode seriously outperformed the TM modes according to the Brady et al paper. This is all boiling down to QV-magnetic interaction in the presence of PT symmetry breaking.

My mixologist keeps explaining this to me but her timing is horrible and I keep forgetting!

There is something going on here!

Disclaimer, that 1880.4mhz freq is also below the cutoff for 6.25 inches, which is why I went crazy on evanescent field coupling for a couple weeks.
Title: Re: EM Drive Developments
Post by: Rodal on 11/08/2014 09:46 pm
http://ptp.oxfordjournals.org/content/119/3/351.full.pdf+html

Peculiar indeed.
As I have pointed out previously, this requires anisotropy, and the author makes it clear (even in the title).  "Momentum Transfer between Quantum Vacuum and Anisotropic Medium"

The author further points out:

Quote
In most conventional electromagnetic  media, the quantum vacuum inside possesses a universal symmetry and hence has no influence on the motion of the media. However, for a Faraday chiral material,the macroscopically observable mechanical effect, due to the breaking of the universal symmetry of the quantum vacuum may appear

What the author is discussing does not apply to the EM drives researched by NASA Eagleworks because the materials used are isotropic.  (Copper in all cases and in some cases Teflon or Polyethylene dielectrics -injection molded-)
Title: Re: EM Drive Developments
Post by: Mulletron on 11/08/2014 09:58 pm
The vacuum catastrophe has haunted me before and now it is again. Any creative ideas on how quantum and classical can both be right? LOL. Either way, I have a lot to play with 10^14 GeV/m3  OR 10^121 GeV/m3. 107 orders of magnitude difference, means there is a lot to understand still. Which directly effects us, if we want to really understand emdrive. If you're a QV kinda person that is.

What I'm trying to figure out are the properties of not a single virtual electron-positron pair which yoinks in and out of existence with Planck time (or was it near Planck time?), but the properties of the aggregate sea of particle pairs coming in and out of existence, unsynchronized at random. That to me leads to a non zero temperature. Which is why we can never ever reach absolute zero for example. That also leads me to a non zero momentum given that energy is present and electrons have mass. Of course, you don't need mass to have momentum, just energy and motion is enough. The tricky part is the motion. Is the QV inertial? Or is it non inertial? I suspect, but it is only a hunch that it is invariant wrt reference frame. Am I barking up the right tree here with electron-positron pairs? Why not photons? This QV business is strange indeed and it literally keeps me awake at night.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/08/2014 10:03 pm
http://ptp.oxfordjournals.org/content/119/3/351.full.pdf+html

Peculiar indeed.
As I have pointed out previously, this requires anisotropy, and the author makes it clear (even in the title).  "Momentum Transfer between Quantum Vacuum and Anisotropic Medium"

The author further points out:

Quote
In most conventional electromagnetic  media, the quantum vacuum inside possesses a universal symmetry and hence has no influence on the motion of the media. However, for a Faraday chiral material,the macroscopically observable mechanical effect, due to the breaking of the universal symmetry of the quantum vacuum may appear

What the author is discussing does not apply to the EM drives researched by NASA Eagleworks because the materials used are isotropic.  (Copper in all cases and in some cases Teflon or Polyethylene dielectrics -injection molded-)

If you looook haaarder, it says anisotropic quantum-vacuum fluctuation field to a Faraday (magnetic) chiral material.

The author is speaking to the anisotropic electromagnetic properties of the material. Not the isotropy of the solidified melt mix. In fact, not linked to here because it is an afterthought, but I've seen references to this kind of effect in disordered materials in the literature.

Exact quote, "Here, we present an effect of the quantum vacuum contribution
to the macroscopic mechanical properties of an anisotropic material (Faraday
chiral material), in which an anisotropic electromagnetic environment could be built
up, and hence the universal symmetry of the quantum vacuum could be broken."

Injection molding does nothing to ensure polymer ordering, aka alignment. An injection molding machine doesn't do any poling.

This paper isn't an exact match to the conditions within emdrive, but demonstrates the diversity of this interaction which is cropping up in other places across the literature.....eg. Robustness.
Title: Re: EM Drive Developments
Post by: Rodal on 11/08/2014 10:19 pm
http://ptp.oxfordjournals.org/content/119/3/351.full.pdf+html

Peculiar indeed.
As I have pointed out previously, this requires anisotropy, and the author makes it clear (even in the title).  "Momentum Transfer between Quantum Vacuum and Anisotropic Medium"

The author further points out:

Quote
In most conventional electromagnetic  media, the quantum vacuum inside possesses a universal symmetry and hence has no influence on the motion of the media. However, for a Faraday chiral material,the macroscopically observable mechanical effect, due to the breaking of the universal symmetry of the quantum vacuum may appear

What the author is discussing does not apply to the EM drives researched by NASA Eagleworks because the materials used are isotropic.  (Copper in all cases and in some cases Teflon or Polyethylene dielectrics -injection molded-)

If you looook haaarder, it says anisotropic quantum-vacuum fluctuation field to a Faraday (magnetic) chiral material.

The author is speaking to the anisotropic electromagnetic properties of the material. Not the isotropy of the solidified melt mix. In fact, not linked to here because it is an afterthought, but I've seen references to this kind of effect in disordered materials in the literature.

"Here, we present an effect of the quantum vacuum contribution
to the macroscopic mechanical properties of an anisotropic material (Faraday
chiral material), in which an anisotropic electromagnetic environment could be built
up, and hence the universal symmetry of the quantum vacuum could be broken."

Injection molding does nothing to ensure polymer ordering, aka alignment. An injection molding machine doesn't do any poling.

This paper isn't an exact match to the conditions within emdrive, but demonstrates the diversity of this interaction which is cropping up in other places across the literature.....eg. Robustness.
The EM Drives tested by NASA Eagleworks do not satisfy the anisotropy  (mechanical and electromagnetic) conditions required by the author. What the author discusses is not applicable to explain the measurements at NASA Eagleworks.
Title: Re: EM Drive Developments
Post by: aero on 11/08/2014 11:29 pm
Quote
The EM Drives tested by NASA Eagleworks do not satisfy the anisotropy  (mechanical and electromagnetic) conditions required by the author. What the author discusses is not applicable to explain the measurements at NASA Eagleworks.

@Mulletron - That does not mean necessarily that you're on the wrong track, just that our current understanding is not sufficiently complete to attribute the measured force. (I know, that sounds like gobbally-gook)  :)
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/09/2014 03:17 am
Quote
@ThinkerX The energy of light is proportional to the frequency. Higher frequency, higher energy photons. If some of that energy is given up to something else, the frequency is lower.

Aha! So...you'd want to start with the highest frequency laser you could manage...but with increasing bounces resulting in decreasing frequencies/energy, you should still be able to multiply the over all...'thrust?'...a few dozen times?

Did some online checking.  Seems the amplification effect is 3000+ times (experiments by a Doctor Bae from 2007on recycling photons), but they're talking paired spacecraft, not a single vehicle.  As long as the system is not closed, it should work with a single craft...right? 

Thank you!


Quote
All of your lazers and power plants are very massive.  The device will hardly move.  However, place your lazers on a handy airless planet, and aim them at a solar sail, and you can get the thing to move.

A solar sail larger than Texas...which might as well not be there at all once you get out a few thousand au, where the laser energy becomes diffuse.

Barely moving is still moving, more its low cost constant acceleration.  Yes, gotta get the size (mass) of the power plants and lasers scaled down.  Still, done right, should get you to relativistic speeds in a decade or two...might have to break down and run the numbers on that.

Ok, apologies for the thread jack, and thanks to the both of you.
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/09/2014 03:22 am
In further apology for my last post, Doctor McCulloch has a new post on his blog

http://physicsfromtheedge.blogspot.com/

More humorous than informative, but what the heck.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/09/2014 07:25 am
Quote
The EM Drives tested by NASA Eagleworks do not satisfy the anisotropy  (mechanical and electromagnetic) conditions required by the author. What the author discusses is not applicable to explain the measurements at NASA Eagleworks.

@Mulletron - That does not mean necessarily that you're on the wrong track, just that our current understanding is not sufficiently complete to attribute the measured force. (I know, that sounds like gobbally-gook)  :)

Well I accepted the challenge. It took me 30 minutes to find that both extruded PE and PTFE solidify to a semicrystalline structure. Therefore they are anisotropic. If they were amorphous, they'd be isotropic.

So I've established that the materials used in the the Brady et al test campaigns are both chiral polymers and they are both anisotropic due to their semicrystalline structure.

I'll save you the trip to the Oracle this time.
See for yourself. Just google crystallization of polymers.
Also google chiral polymer tacticity.

A neat resource I found:
https://www.nde-ed.org/EducationResources/CommunityCollege/Materials/Structure/anisotropy.htm

Also two exciting words: lamella twisting, here's helical chirality in PE
http://www.esrf.eu/UsersAndScience/Publications/Highlights/2011/scm/scm4

Chirality=proven true
mechanical anisotropy=proven true
electromagnetic or magnetic anisotropy=not proven true, this is where spontaneous pt symmetry breaking comes in. Been working on this one for a while.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/09/2014 08:52 am
Anyone want to take a stab at Zeeman's potential/energy breaking time reversal symmetry?

Is it a hero? Or a zero?

This is all pretty new to me so I thought I'd see if there were any experts out there who know about this stuff. Otherwise I'll have to endure the learning curve to get up to speed.

The Oracle does connect this with spontaneous symmetry breaking, magnetic anisotropy, micromagnetics and bi-isotropic materials.

So I'm seeing a concept forming that I loosely grasp.

Can anyone explain the 3 slides attached, Bill Nye or popular Feynman style?

I just want to add that spontaneously broken time reversal symmetry isn't some whiz bang Star Trek kind of thing. It is manifest in ferromagnetism, which is happening right now on your refrigerator door. I can restore that symmetry simply by heating up the magnet past the Curie point.
Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 11:50 am
Quote
The EM Drives tested by NASA Eagleworks do not satisfy the anisotropy  (mechanical and electromagnetic) conditions required by the author. What the author discusses is not applicable to explain the measurements at NASA Eagleworks.

@Mulletron - That does not mean necessarily that you're on the wrong track, just that our current understanding is not sufficiently complete to attribute the measured force. (I know, that sounds like gobbally-gook)  :)

Well I accepted the challenge. It took me 30 minutes to find that both extruded PE and PTFE solidify to a semicrystalline structure. Therefore they are anisotropic. If they were amorphous, they'd be isotropic.

So I've established that the materials used in the the Brady et al test campaigns are both chiral polymers and they are both anisotropic due to their semicrystalline structure.

I'll save you the trip to the Oracle this time.
See for yourself. Just google crystallization of polymers.
Also google chiral polymer tacticity.

A neat resource I found:
https://www.nde-ed.org/EducationResources/CommunityCollege/Materials/Structure/anisotropy.htm

Also two exciting words: lamella twisting, here's helical chirality in PE
http://www.esrf.eu/UsersAndScience/Publications/Highlights/2011/scm/scm4

Chirality=proven true
mechanical anisotropy=proven true
electromagnetic or magnetic anisotropy=not proven true, this is where spontaneous pt symmetry breaking comes in. Been working on this one for a while.

Neither PTFE (Tefflon) or Polyethylene are mechanically or electromagnetically anisotropic in bulk.  I have measured their directional properties with Dielectrometry, NMR, TMA, DTMA and with MTS.  Semi crystallinity in thermoplastic polymers is not at all like well ordered crystalline metals.  The "crystalline" regions have independent domains oriented randomly throughout the polymer.  Extrusion anisotropy takes place at the exterior surface of the extruded rod in regions of very high shear near the extruder walls.  The interior of the extruded rod is isotropic.   Injection molded PTFE and PE are isotropic due to the random orientation produced during the injection molded process.

There are proprietary manufacturing methods to produce mechanically , electromagnetically and  optically anisotropic polymers, for example when making optically anisotropic polarized lenses.  One would not use extrusion to make such lenses.    It is much easier to attain preferred orientation, overall-anisotropic materials for thin polymer sheets or for very small diameter filaments. 
Title: Re: EM Drive Developments
Post by: Mulletron on 11/09/2014 12:46 pm
Quote
Extrusion anisotropy takes place at the exterior surface of the extruded rod in regions of very high shear near the extruder walls.

Good enough for me! I could care less about the interior of the bulk. This supports your previous observations about the limited utility of a monolithic dielectric slug vs rolled thin films.

Thanks for your valuable contribution from your experience. As they say, knowledge is cheap, but experience is priceless.
Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 01:20 pm
Quote
Extrusion anisotropy takes place at the exterior surface of the extruded rod in regions of very high shear near the extruder walls.

Good enough for me! I could care less about the interior of the bulk. This supports your previous observations about the limited utility of a monolithic dielectric slug vs rolled thin films.

Thanks for your valuable contribution from your experience. As they say, knowledge is cheap, but experience is priceless.
I recall that other members (not you ? or me) in this forum were of the opinion that the following picture showed that the (pink colored) "dielectric" originally in the NASA Eagleworks truncated cone was a huge injection molded piece.  I was surprised at the time, and I am still surprised that they would use such a huge piece (essentially a significant portion of the cavity would be taken by the dielectric).  Such a huge rod of dielectric would be most likely injection molded rather than extruded. 

Are people still of the opinion that this picture shows the dielectric (in pink)? Is it common to use such a huge volume of dielectric?  What is the reason for such a huge volume of dielectric? 


It is interesting that Eagleworks switched to a much smaller volume of a thinner annular disk dielectric for their "future" testing (they did not say why) as shown at the bottom (yellow and red disk in blue background).  The circular inner hole and the thinner disk appear to be intentional.

Notice that the dielectric is at the small diameter end (both in the old design and in the new design), while the measured displacement is towards the opposite end: the large diameter end.

It think that the measured forces are an experimental artifact due to thermoelasticity, and that the dielectric placement at the small diameter end maximizes this effect, as I will show with results as time permits.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/09/2014 01:24 pm
No. The paper says it was 2, 6.25" x 1.06" PE discs. Aero pointed this out I think. That pink area looks to me like a copper cylinder structure to hold those disks in place.


Do you see why my CAD had 6.25" for the minimum diameter possible for the small end now?
Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 01:36 pm
No. The paper says it was 2, 6.25" x 1.06" PE discs. That pink area looks to me like a copper cylinder structure to hold those disks in place.


Do you see why my CAD had 6.25" for the minimum diameter possible for the small end now?

OK, thanks for reminding me.  So is your interpretation that there are two disks 6.25" OD.  Is 1.06" the thickness of the disks? or is it the Inner Diameter of a hole in an annular disk and is the thickness unspecified?  (I would presume the former as it would be unusual not to specify the thickness).

These dimensions make much more sense.

QUESTION: If you were to place a dielectric in the EM Drives for your QV purposes, where would you preferentially place it: at the small diameter or the big diameter end and why?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/09/2014 01:53 pm
No. The paper says it was 2, 6.25" x 1.06" PE discs. Aero pointed this out I think. That pink area looks to me like a copper cylinder structure to hold those disks in place.


Do you see why my CAD had 6.25" for the minimum diameter possible for the small end now?

OK, thanks for reminding me.  So is your interpretation that there are two disks 6.25" OD.  Is 1.06" the thickness of the disks? or is it the Inner Diameter of a hole in an annular disk and is the thickness unspecified?  (I would presume the former as it would be unusual not to specify the thickness).

These dimensions make much more sense.

QUESTION: If you were to place a dielectric in the EM Drives for your QV purposes, where would you preferentially place it: at the small diameter or the big diameter end and why?

I get a 6.25wide x 1.06tall inch cylinder. No hole in it. The next gen thruster seems to have a hole, maybe? That's another story though.

If I were building one, I'd put the dielectric in areas of high magnetic field strength. I drew some pics of this a long time ago and posted them. I don't see a preference for locating the slugs at the big end or small end. Both ends enjoy the same asymmetry. One side is large and the other side is small. No matter if you put the dielectric at one end or the other, they still see the same large end on one side and small end on the other. I criticized the builder for putting the discs only at the small end though. Certain mode shapes won't even touch the dielectric if the discs are only at the small end.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/09/2014 01:57 pm
Reply #3038 on: November 08, 2014, 04:33:35 PM

...oops, I see 93143 answered faster. Glad to hear someone of the million people...

Reply #3013 on: November 07, 2014, 03:40:29 PM

Your pragmatic inertial frame would be the galaxy, wouldn't it?

So what am I, chopped liver?

To elaborate, with words, not math, but hey:

The phrase "sum the instantaneous frames of rest" has the same mathematical meaning as does the phrase "add up kinetic energy in different reference frames".

The Appendix spacecraft is said to go from 0 mph to 1 mph, in its reference frame.  It doesn't go from 671 mph to 672 mph, except as a math exercise of intellectual interest, not as a matter pf pragmatic space travel.   Besides 672 mph is not a relativistic speed, and neither is 672 km/s.

There is not a line of mathematical reasoning which adds up kinetic energy in different, presumably aritrarily preferred, reference frames, and results inexorably in a new type of propulsion.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/09/2014 02:27 pm
What the author is discussing does not apply to the EM drives researched by NASA Eagleworks because the materials used are isotropic.  (Copper in all cases and in some cases Teflon or Polyethylene dielectrics -injection molded-)

Hah! 

Primitive man get something without aid of mixologist!

Quote from: Jian Qi Shen's paper
An anisotropic electromagnetic environment that can be created inside a Faraday chiral material may cause breaking of the universal symmetry of vacuum mode structure and hence lead to a nonzero electromagnetic momentum density of the quantum vacuum. A novel quantum vacuum effect (i.e., transfer of linear momentum from an anisotropic quantum-vacuum fluctuation field to a Faraday chiral material) is predicted. This is a macroscopic quantum vacuum mechanical effect that may provide us with new insight into the electromagnetic structures of quantum vacuum fluctuation fields inside anisotropic artificial materials.

Me not sure how Shen can assert that it is a "macroscopic" quantum vacuum mechanical effect, since that, to me, kinda sorta implies that my old eyes could see the effect.  So me not get that. 

Note however his careful wording about how we might gain "new insight" into these anisotropic fields.  The terms "benign", "wormholes, and "Jovian" do not appear in his claims nor conclusion.

He does mention "vacuum-induced Berry’s phases".  I had no idea that Chuck was interested in this subject.

Seriously, the "transfer of linear momentum" is the matter at hand.  It is an issue that EagleWorks is ostensibly interested in, under the moniker "EM Drive".  But forget those makers of chopped liver, whose mothers were probably hamsters.

Perhaps there is another generic term which could be used for a drive of this sort.  If the "anisotropy of the quantum vacuum" does "lead to the transfer of momentum from a quantum vacuum to an anisotropic material", then would it be possible to make your spacecraft propulsion system out of significant quantities of this "anisotropic material", which should be called something.  Perhaps "unobtainium"?

Or am I confusing "electromagnetic momentum inside materials" with the actual pragmatic momentum associated with HSF?

In short, is this a true statement?

Quote from: Shen
As the quantum vacuum in an anisotropic electromagnetic environment has a nonzero momentum, the linear momentum transfer between the quantum vacuum and a gyrotropic chiral material can take place.

And if it is, do these examples have any pertinance to HSF?

Quote from: Shen
this vacuum effect may provide us with new insight into electromagnetic structures of quantum vacuum fluctuation inside artificial anisotropic materials, and we may be able to utilize this mechanical effect to develop sensitive, accurate measurement technologies. In addition, such quantum vacuum effects may lead to new topics regarding fundamental physical problems, such as field quantization, inertia of photon’s spin (in spin-rotation coupling) and some relevant quantum optical effects inside composite materials.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/09/2014 02:38 pm
So I've established that the materials used in the the Brady et al test campaigns are both chiral polymers and they are both anisotropic due to their semicrystalline structure.

Woah, there, kemosabe! 

That sounds like an assertion?  Like where, 'zackly does the Brady bunch inform us that they depend on these chiral polymers?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/09/2014 02:41 pm
All those papers about transferring linear momentum from the QV to chiral molecules I've been posting since page 126 say that. Rodal posted one from Donaire too.

The Shen paper was an accidental find that I didn't intend to directly tie to emdrive. I was looking for other authors besides Tiggelen, Feigel, and Donaire to see if others were talking about this. By doing this I can shore up the QV approach and show novelty does exist. Or I can put it to bed like MiHsC (IMHO). You know how gaga I used to be about EMdrives using MiHsC. In the end I don't care about the theory, just the truth.

I want some professionally scientific person to read something on this forum that doesn't make them laugh and close their browser window in disgust. Instead I want them to say, "now that's curious!"

I want to stir interest. So this thing gets off the ground.

If the experiments fail to replicate further.....It was still fun. Something was learned by everyone concerned either way.
Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 02:57 pm
So I've established that the materials used in the the Brady et al test campaigns are both chiral polymers and they are both anisotropic due to their semicrystalline structure.

Woah, there, kemosabe! 

That sounds like an assertion?  Like where, 'zackly does the Brady bunch inform us that they depend on these chiral polymers?

Now, were one to consider the QV momentum due to chirality proposal, imagine if instead of using PTFE or PE, were one to use true chiral polymers (with chirality in the backbone) using for example phosphane-containing polyisocyanate as a catalyst for the asymmetric hydrogenation of dehydro amino acid N-acetamidocinnamic acid, or as another example the asymmetric polymerization Diels–Alder reaction of asymmetric addition of allylsilane to aldehyde, and utilize an anisotropic manufacturing method to have a homogeneously anisotropic chiral polymer.  Or this polymerization method for acetylene in an asymmetric reaction field using a chiral nematic liquid crystal, which demonstrates the formation of a polyacetylene film comprised of helical chain:

(http://www.sigmaaldrich.com/content/dam/sigma-aldrich/articles/material-matters/material-matters-volume3/chiral.gif)

If the present EM Drive tests at NASA Eagleworks would be due to chirality, were one to use a true chiral polymer the momentum would increase by orders of magnitude, hence the numbers used by Dr. White for the fast trip to Enceladus would have been too conservative.  One could use frobnicat's proposal of a generator constructed by EM Drives with chiral polymers powering the EM Drive propulsion. 

No, I don't think that's what happening,  I think that the NASA Eagleworks results are a thermal artifact.  None of the researchers used a true chiral polymer.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/09/2014 03:05 pm
Yeah I'm hearing you on pseudo-chirality. The monomers aren't chiral, but the repeating units are. We're lucky both PE and PTFE feature those Carbon atoms. Else, chirality would most certainly be dead. In the end, they are chiral. I think your ideas above could be ground breaking stuff. If correct. Certainly an improvement.
Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 03:14 pm
Yeah I'm hearing you on pseudo-chirality. The monomers aren't chiral, but the repeating units are. We're lucky both PE and PTFE feature those Carbon atoms. Else, chirality would most certainly be dead. In the end, they are chiral. I think your ideas above could be ground breaking stuff. If correct. Certainly an improvement.
I would like somebody to conduct an experiment to show whether indeed the quantum vacuum can impart momentum to a chiral polymer.   It sounds unphysical to me that this can happen (I interpret the Casimir effect as due to van der Waal forces and not to the QV). 

But, hey, I see all these theoretical papers you have uncovered, why don't they show this effect in an actual experiment?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/09/2014 03:25 pm
It looks like EMdrive testing may have blundered into such an experiment.

I can't rule out heat either. I see heat in the TE012 plot. See white thrust attachment below. I drew on it in green. There is heat, but there is something else too.

But also attached are screenshots with text circled on exactly why I feel the dielectric is the key here.

Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 05:30 pm
....
Have also to check the heat(t) at the inner surface of copper (might be higher/faster than expected) as a rise of temperature of 10° on 100cm^3 can give as much "oomph" as 5° on 200cm^3 or 1° on 1000cm^3, so lack of thermal conductivity of air might not be the relevant factor to set the typical Tau. + some heat equations...
.....

Maybe if you are working on heat conduction aspects at the cavity's wall, this might help me if you have an idea of the Temp(t) of the inner skin. I know that copper is a very good thermal, conductor. The epoxy behind the (probably) much thinner copper of PCBs end plate not that much. The RF power is dissipated in the first µm depth skin. What gives instant temperature for the air molecules hitting the inner walls ? This could be a fast alternative to volumetric humid air heating.

Considering the copper thickness to be thermally insulated at z=0 and be subject to heat (energy per unit time, per unit area) "heatFlux" at z=thickness, the complete transient solution for the temperature increase is (where "t" is time in seconds):

temperature=(heatFlux*thickness/thermalConductivity)*( (t/fourierTime) + ((1/2)*((z/thickness)^2) - (1/6)) + temperatureSum

where:

temperatureSum=(heatFlux*thickness/thermalConductivity)*(-(2/(Pi^2))*NSum[(((-1)^n)/(n^2))*(Exp[- (t/fourierTime)*((n*Pi)^2)])*Cos[n*Pi*(z /thickness)], {n, 1, Infinity}])

fourierTime = (thickness^2)/thermalDiffusivity

thermalDiffusivity = thermalConductivity/(density*heatcapacityperunitmass)

For copper, we have the following material properties:

density = 8940 (* kg / (m^3) *);
thermalConductivity = 390  (* W/(m * degK)*);
heatcapacityperunitmass = 385 (* J/(kg * degK)*);

therefore:

thermalDiffusivity = 0.00011331 (m^2)/s

fourierTime = (thickness^2)*8825.38

So we see that steady-state conditions occur very fast due to the very small thickness. 
For example, for thickness = (1/32 inch) * (25.4/1000 m/inch)

fourierTime = 0.00556034 seconds

For example, for thickness = (1/4 inch) * (25.4/1000 m/inch)

fourierTime = 0.355862 seconds


Therefore the temperatureSum term is negligible for time responses in the order of seconds.  The term ((1/2)*((z/thickness)^2) - (1/6)) is also negligible in comparison with (t/fourierTime), so essentially we are left with

temperature ~ (heatFlux*thickness/thermalConductivity)*(t/fourierTime)

                       ~ heatFlux*t*/(density*heatcapacityperunitmass*thickness)

For copper,

density*heatcapacityperunitmass = heatcapacityperunitvolume = 8940*385 (* J/((m^3) * degK)*)

hence,

temperature ~ heatFlux*t*/((3.4419*10^6)*thickness)

where heatFlux has units of W/m^2, thickness in meters and t in seconds.

Calculation of the Heat Flux:

For the transverse electric mode TE012 (p. 18, Table 2. Tapered Cavity Testing: Summary of Results) of the "Anomalous Thrust..." paper by Brady et.al., the Input Power was 2.6 Watts.

Adopting the latest measurement estimates by aero:

SmallDiameter = 0.1549 m
BigDiameter = 0.2793 m

and the input power gets converted into heat (see Greg Egan for discussion), and since the TE012 only the axial magnetic field is non-zero in contact with the big and small diameters, the heat flux is:

heatFlux = (2.6 W) /FluxedArea

where the FluxedArea is:

(Pi/4)*( SmallDiameter^2 + BigDiameter^2 ) / Factor

where

Factor = (ActualDiameter / DiameterOfAreaExperiencingHeatFlux)^2

accounts for the fact that the magnetic flux in mode TE012 contacts only a fraction of the entire circular areas at the ends of the truncated cone.

Therefore,

heatFlux = (32.454 W/m^2) * Factor

Substituting this in our expression for temperature:

temperature ~ heatFlux*t*/((3.4419*10^6)*thickness)
                        ~ (32.454 W/m^2) * Factor * t*/((3.4419*10^6)*thickness)

                        ~ Factor * t*/((1.0605*10^5)*thickness)

So, for thickness = 1/32 inches = 0.0007938 m and Factor = 3 (equivalent to a diameter being heated by the magnetic axial flux as 57.74% of the full diameter)

temperature = (t / 28.059 s) deg C
the temperature increase at 2.6 sec (the pendulum half period) is only 0.09 deg C, and at 30 sec is 1.07 deg C

So, for thickness = 0.02 inches = 0.0005080 m and Factor = 3 (equivalent to a diameter being heated by the magnetic axial flux as 57.74% of the full diameter)

temperature = (t / 17.958 s) deg C
the temperature increase at 2.6 sec (the pendulum half period) is only 0.14 deg C, and at 30 sec is 1.67 deg C



Notice assumptions:

1) All input power is converted into heat
2) axial heat conduction away from heated zone is neglected
3) surface (at z=0) is assumed to be perfectly insulated (by the PCBoard composite material and the surrounding air)
4) diameter being heated by the magnetic axial flux assumed as 57.74% of the full diameter. For other values change "Factor" accordingly.  In the worst case (assuming that the whole diameter is being heated, which is clearly not the case) Factor = 1, and hence the calculated temperatures are 1/3 of the value calculated.
Title: Re: EM Drive Developments
Post by: aero on 11/09/2014 05:45 pm
No. The paper says it was 2, 6.25" x 1.06" PE discs. Aero pointed this out I think. That pink area looks to me like a copper cylinder structure to hold those disks in place.


Do you see why my CAD had 6.25" for the minimum diameter possible for the small end now?

I had certainly forgotten about that but it seems that the 6.25 inch diameter of the Brady cavity small end is just as certain as the 160 cm and 280 cm diameter numbers from Shawyer for his cavity's large end.

My measurement technique and correction factors give me high confidence in my estimate of the Brady cavity large end diameter. My confidence level goes down from there because the photo's don't show the small end with nearly as much clarity. Hence choosing the top of the small end diameter (and the bottom to a lesser extent) is in large part, guesswork. That uncertainty affects the measurement of cavity length as well though not as strongly. The length would be somewhat shorter as I took it to be the length of a rectangle with the four corners at the corners of the small end and within the large end. Increasing the height of that rectangle by another 1/2 cm (the difference between 6.25 inches and my estimate) would force a shortening of the rectangle in order that the corners stay on the arc of the small end. A quick check with my ruler tool gives a shortening of about 4 pixels which translates into these updated measurements.

Dimension Inches     cm
 Big Dia.    10.727     27.246
Small Dia. 6.250     15.875
 Length     9.517     24.173
 Best estimate as of 11/9/2014
Title: Re: EM Drive Developments
Post by: frobnicat on 11/09/2014 05:46 pm
Reply #3038 on: November 08, 2014, 04:33:35 PM

...oops, I see 93143 answered faster. Glad to hear someone of the million people...

Reply #3013 on: November 07, 2014, 03:40:29 PM

Your pragmatic inertial frame would be the galaxy, wouldn't it?

So what am I, chopped liver?

don't get what that reference to butchery might mean

That I can say is that there is no such thing as preferred inertial frame (dixit Newton and Einstein). What is "your pragmatic inertial frame" depend on the dynamical system that's to be predicted but what is for sure is that you have the exact same predicted results whatever the inertial frame chosen (why "arbitrary frame") and even accelerated reference frame (done properly). There is often a "natural" frame that makes the calculations more elegant and simple and results easier to interpret, but such frame is still just an arbitrary choice to compare all velocities to the one and same, well, reference. You can also use multiple frames and transform values (velocities, energies ...) from one to another, done properly this is also correct.
But often there is only one frame of reference and many velocities measured relative to this one frame once it's chosen. It appears this is causing mental confusion, to be clear I repeat : many velocities don't mean many frames of references (and the difficulties that go with such frame changes, though they are very well understood and surmountable).

So, the one "natural" frame chosen depend on the subject, for a satellite at earth orbit that would earth centre, for a earth-moon trajectory it might be the centre of mass of both bodies, for interplanetary mission that would probably heliocentric frame (sun defines 0 speed). For all above missions you couldn't care less about your speed relative to galaxy or CMB, you only care about your speed relative to (respectively) earth, earth-moon, sun. But you could calculate a road trip to Chicago (?) in the CMB frame and see the same results in practical fuel consumption and time it takes and all that matters. Only with very huge intermediate values.

If you intend on crashing into an asteroid then your pragmatic inertial frame is this body. There is no pragmatic (nor theoretic) difference between crashing at 10km/s in an asteroid at rest or being at rest and being smashed by an asteroid coming by 10km/s. Nothing is at absolute rest really, all is relative to another thing. That is relativity. That is easy. Since Newton.

I know that makes some people uneasy because they would be reassured to have an aether to define an "absolute background rest state of motion". Well, we where born on earth, and earth surface certainly looks like such and absolute rest state of motion, universally available. So it's quite possible humans have a certain psychological need to see such a universal reference of 0 motion. Appears this is not the way nature works. There is something like an average coherence of motions on a local patch of cosmic matter, that is roughly the same as the CMB local frame, but it is not universal (it is local and changes from place to place) and no body really cares, the Andromeda and our galaxy will collide in the same way in the same time regardless of their average common speed relative to local CMB apparent rest frame, be it 0 or 600km/s.

Quote
To elaborate, with words, not math, but hey:

The phrase "sum the instantaneous frames of rest" has the same mathematical meaning as does the phrase "add up kinetic energy in different reference frames".

All right then, now we are not happy enough with one frame of reference or two but we want to use them all. Note that, as explained above, we don't need more than one frame to have a clear and unambiguous answer to any question we might ask. You do a summation when different values of a parameter say different things. There it all says the same thing, so why would you want to sum ? How are we supposed to proceed and in what are we expected to see any difference ?

Quote
The Appendix spacecraft is said to go from 0 mph to 1 mph, in its reference frame.  It doesn't go from 671 mph to 672 mph, except as a math exercise of intellectual interest, not as a matter pf pragmatic space travel.   Besides 672 mph is not a relativistic speed, and neither is 672 km/s.

mph ???
The choice of CMB as reference frame is not pragmatic for commodity of calculations, but its results are as much pragmatic as any other one, it will tell the same times of transits and the same kinetic energy relative to spent energy. The same kinetic energy released when impacting a given asteroid (cant be more pragmatic).

Now if you want to speak of "intrinsic" kinetic energy, not of kinetic energy released by two given objects colliding, then it is nonsense. Giving a kinetic energy without saying "relative to what" is like giving a velocity without saying "relative to what" (Shawyer is doing that a lot), it has no meaning. It is like I say : the temperature in my garden is 13835. If I don't say in what units that has no meaning. If I say it's in milli celcius degrees then it makes sense. Am I to sum the temperature in all possible temperature scales (frames) to really know the temperature ?

Quote
There is not a line of mathematical reasoning which adds up kinetic energy in different, presumably aritrarily preferred, reference frames, and results inexorably in a new type of propulsion.

I don't know why I argue at length, we agree on that (I think).
Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 05:50 pm
....
Have also to check the heat(t) at the inner surface of copper (might be higher/faster than expected) as a rise of temperature of 10° on 100cm^3 can give as much "oomph" as 5° on 200cm^3 or 1° on 1000cm^3, so lack of thermal conductivity of air might not be the relevant factor to set the typical Tau. + some heat equations...
.....

Maybe if you are working on heat conduction aspects at the cavity's wall, this might help me if you have an idea of the Temp(t) of the inner skin. I know that copper is a very good thermal, conductor. The epoxy behind the (probably) much thinner copper of PCBs end plate not that much. The RF power is dissipated in the first µm depth skin. What gives instant temperature for the air molecules hitting the inner walls ? This could be a fast alternative to volumetric humid air heating.


In this message:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1281247#msg1281247 notSoSureOfIt proposes that the circular ends of the truncated cone tested at NASA Eagleworks was made of copper only 0.002 inches thick bonded to the PCBoard.

Using the formula and material property values from http://forum.nasaspaceflight.com/index.php?topic=29276.msg1285890#msg1285890, the temperature increase is


temperature ~ Factor * t*/((1.0605*10^5)*thickness)

for thickness = 0.002 inches = 0.00005080 m and Factor = 3 (equivalent to a diameter being heated by the magnetic axial flux as 57.74% of the full diameter)

temperature = (t / 1.7958 s) deg C


the temperature increase at 2.6 sec (the pendulum half period) is 1.4 deg C, and at 30 sec is 16.7 deg C




NOTE: if the ends were made of extremely thin copper bonded on PCBoard, there are serious questions as to why would anybody do this aside from trying to maximize artificial heating of the ends



Notice assumptions:

1) All input power is converted into heat (see Greg Egan's discussion)
2) axial heat conduction away from heated zone is neglected
3) surface (at z=0) is assumed to be perfectly insulated (by the PCBoard composite material and the surrounding air)
4) diameter being heated by the magnetic axial flux assumed as 57.74% of the full diameter. For other values change "Factor" accordingly.  In the worst case (assuming that the whole diameter is being heated, which is clearly not the case) Factor = 1, and hence the calculated temperatures are 1/3 of the value calculated.
Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 06:18 pm
....
Have also to check the heat(t) at the inner surface of copper (might be higher/faster than expected) as a rise of temperature of 10° on 100cm^3 can give as much "oomph" as 5° on 200cm^3 or 1° on 1000cm^3, so lack of thermal conductivity of air might not be the relevant factor to set the typical Tau. + some heat equations...
.....

Maybe if you are working on heat conduction aspects at the cavity's wall, this might help me if you have an idea of the Temp(t) of the inner skin. I know that copper is a very good thermal, conductor. The epoxy behind the (probably) much thinner copper of PCBs end plate not that much. The RF power is dissipated in the first µm depth skin. What gives instant temperature for the air molecules hitting the inner walls ? This could be a fast alternative to volumetric humid air heating.

Recall from our discussion that NASA Eagleworks covered the interior small diameter end of the truncated cone with two Polyethylene discs, each being 1.06 inch thick, for a total thickness of 2.12 inches of polymer insulating the interior small end. 

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=619752;image)

Any such polymer disk acts as an insulator over the area where the axial magnetic field introduces a heat flux under transverse electric mode TE012. With the small end intentionally covered by the combined 2.12 inch thick polymer disks (that the NASA researchers claimed is a dielectric whose intention is to couple with the Quantum Vacuum) the only area where the magnetic field in transverse electric mode TE012 can heat is the big diameter end.

So under the 2.6 Watts of input power for TE012 experiment, instead of the heat flux being (when both the smalll and the big ends are heated):

heatFlux = (32.454 W/m^2) * Factor


using the measurement estimates from aero:

SmallDiameter = 0.1549 m
BigDiameter = 0.2793 m

when the NASA researchers covered the small end with this PE disk which they call a dielectric, the heat flux on the big end now becomes

heatFlux = (32.454 W/m^2) * Factor*(BigDiameter ^2 + SmallDiameter^2)/(BigDiameter^2)
               = (32.454 W/m^2) * Factor*(1 + (SmallDiameter/BigDiameter)^2)
               = (32.454 W/m^2) * Factor*(1 + ( 0.1549/0.2793)^2)
               = (32.454 W/m^2) * Factor*1.308

or about 31% higher heat flux on the big end



So, for thickness = 1/32 inches = 0.0007938 m and Factor = 3 (equivalent to a diameter being heated by the magnetic axial flux as 57.74% of the full diameter)

temperature = (t / 21.459 s) deg C
the temperature increase at 2.6 sec (the pendulum half period) is only 0.12 deg C, and at 30 sec is 1.40 deg C



So, for thickness = 0.02 inches = 0.0005080 m and Factor = 3 (equivalent to a diameter being heated by the magnetic axial flux as 57.74% of the full diameter)

temperature = (t / 13.734 s) deg C
the temperature increase at 2.6 sec (the pendulum half period) is only 0.19 deg C, and at 30 sec is 2.18 deg C




for thickness = 0.002 inches = 0.00005080 m and Factor = 3 (equivalent to a diameter being heated by the magnetic axial flux as 57.74% of the full diameter)

temperature = (t / 1.3734 s) deg C

the temperature increase at 2.6 sec (the pendulum half period) is 1.9 deg C, and at 30 sec is 21.8 deg C
Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 07:17 pm
Wheter unintentional or an experimental gaffe, it appears as a fact that the NASA Eagleworks researchers did everything possible to maximize internal heating of the big end:

1) They covered the exterior of the small circular end of the truncated cone with PCBoard that acted as an insulator

2) They covered the exterior of the big circular end of the truncated cone with PCBoard that acted as an insulator

3) They covered the interior of the small circular end of the truncated cone with over 2 inches thick of PE polymer insulation, which they called a "dielectric to couple with the Quantum Vacuum"

4) With the PE polymer on the interior small circular end, under transverse electric mode TE012 only the central area of the big circular end of the truncated cone was free to be heated by the axial magnetic field

5) NOTE: if the ends were made of extremely thin 0.002 inch copper bonded on PCBoard, there are serious questions as to why would anybody do this.

Frobnicat has this possible answer:  "Maybe this is the case but it is not recognized as such (artificial heating) by the experimenters, they noticed empirically that it "worked" better so they do it. And they may have an erudite guess about better quantum tunneling of vacuum plasma through thin conductors as a reason. This is the problem of a methodology that works on an unproven effect and wants to maximize the magnitude of the effect rather than having a better grasp at the experimental artefacts and a better signal/noise ratio. Or rather accounted_for/unaccounted_for ratio."

I could not find discussion of this thermal heating effect or on the extremely important thickness of the copper at the big end, on their report.

The comment from Paul March (later reproduced in the next big future blog page) that the external temperature of the EM Drive did not vary by more than 1 degree, becomes irrelevant upon examination that both ends were covered with PCBoard polymer insulation and that they did not report the internal temperature of the copper on the interior of the big end.

The transverse electric field at the interior copper surface under mode TE012 is zero and therefore there is no heating of the curved copper surface of the truncated cone.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/09/2014 07:34 pm
Thank you for those inputs Rodal, this is very precious to me to see what would be the dominant factor for a warm air leak hypothesis, air heating at the surfaces of cavity or volumetric air heating (because of usual water vapor content). The later is still in the limbs quantitatively but I'm confident a decent order of magnitude can be derived from available info, yet needs more reading or finding the silver google hit.

By despair, did a few experiments with my household microwave oven (DIYers please note : closed door, not more than a few seconds empty with power on, somehow managed to put a small plastic tubing through the venting slits to see bubbling in an inverted glass water on a cup, outside the oven... no dismantling, no tinkering with door) and it appears normal air (around 50% relative humidity) is indeed heated, but this is not satisfying because of poor experimental setup, a glass bottle as a cavity was too small (too much surface to volume ratio) and "green glass" contains iron (the glass went warm quite efficiently), a bigger plastic bottle (PET) went deformed by the heat (varying volume of cavity) and went frankly hot. Can't tell if the PET was heated by the air or if PET was the coupling material. Don't know that plastic (non polar I think ?) could heat on microwave. Having no water (except water vapor of air) in those runs in a 1kW household microwave oven, the energy dissipated in what it could (and probably bounced back a lot in the magnetron's face...). An above mentioned source cited on the order of 10000 Q factor for an empty household microwave oven.

This is not experimentally convincing yet, and I complain enough of bad experimental methodologies so that I shouldn't publish, nor even talk informally about it I guess. Nevertheless it convinced me that a high enough Q microwave cavity does indeed transfer some heat to things you wouldn't usually consider as good candidates to be microwave heated because of poor absorption. I wonder how much of dissipated thermal power the bulk of dielectrics received during the experiments at eagleworks tests.

In the end, maybe both effects of surface heating and volumetric heating might have to be taken into account.

Quote from: Rodal
... if the ends were made of extremely thin copper bonded on PCBoard, there are serious questions as to why would anybody do this aside from trying to maximize artificial heating of the ends

Maybe this is the case but it is not recognized as such (artificial heating) by the experimenters, they noticed empirically that it "worked" better so they do it. And they may have an erudite guess about better quantum tunneling of vacuum plasma through thin conductors as a reason. This is the problem of a methodology that works on an unproven effect and wants to maximize the magnitude of the effect rather than having a better grasp at the experimental artefacts and a better signal/noise ratio. Or rather accounted_for/unaccounted_for ratio.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/09/2014 09:01 pm
Yeah I'm hearing you on pseudo-chirality. The monomers aren't chiral, but the repeating units are. We're lucky both PE and PTFE feature those Carbon atoms. Else, chirality would most certainly be dead. In the end, they are chiral. I think your ideas above could be ground breaking stuff. If correct. Certainly an improvement.
I would like somebody to conduct an experiment to show whether indeed the quantum vacuum can impart momentum to a chiral polymer.   It sounds unphysical to me that this can happen (I interpret the Casimir effect as due to van der Waal forces and not to the QV). 

But, hey, I see all these theoretical papers you have uncovered, why don't they show this effect in an actual experiment?

My dear troglodytic interlocutor, and I use the term endearingly,  remember all that stuff I've been saying about seeking funding?

Lo, Shen and company seek the same grail: Continued funding.

Quote from: Shen and all
For these reasons, we hope that the quantum vacuum momentum transfer investigated in this paper can be tested experimentally in the near future.

Maybe they're not talking about their group specifically, but hey; who better to run the experioment than those who proposed the theory?

They're talking lab work somewhere.  Guys with labs like below, need not apply.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/09/2014 09:02 pm
don't get what that reference to butchery might mean

I said it first.  The part about inertial frames.
Title: Re: EM Drive Developments
Post by: Rodal on 11/09/2014 09:07 pm
...a bigger plastic bottle (PET) went deformed by the heat (varying volume of cavity) and went frankly hot. Can't tell if the PET was heated by the air or if PET was the coupling material. Don't know that plastic (non polar I think ?) could heat on microwave.....

Polyethylene terephthalate ("PET" commonly used to make bottles for carbonated drinks like Coca Cola), has oxygen-containing functional groups that make it polar hence it is heated directly by the microwave because of the polar ester groups shown in the picture below, and it should get hot (even without water):

(http://www.pslc.ws/macrog/images/stal06.gif)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/09/2014 09:24 pm
I don't know why I argue at length, we agree on that (I think).

We do agree.  I think you may not completely translate my non-scientific use of the English language, but you are so much more advanced than I am, that it is but a small matter.

Quote from: Frob
What is "your pragmatic inertial frame" depend on the dynamical system that's to be predicted but what is for sure is that you have the exact same predicted results whatever the inertial frame chosen (why "arbitrary frame") and even accelerated reference frame (done properly). There is often a "natural" frame that makes the calculations more elegant and simple and results easier to interpret, but such frame is still just an arbitrary choice to compare all velocities to the one and same, well, reference.

My "pragmatic" frame is probably exactly what you refer to as a "natural" frame.

The Appendix A spacecraft goes from Zero to 1 km/s in 200-ish days, having whatever kinetic energy it has at that time.  Using a Hall thruster, it expells a percentage of its propellant, and, like in my ICBM example from 1961 above, it will have a "paradoxical" excess of kinetic energy at the end of 200-ish days.

For the authors of the paper to engage in relativistic distractions of a comparison of velocity to the CMB, can only be interpreted as a colossal waste of everybody's time, and does not speak well as to their shallow intentions.
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/09/2014 10:22 pm
Ok...so if I correctly grasp the last page or two worth of posts(doubtful), the 'EM Drive' as tested by Eagleworks, is probably bogus, with the 'thrust' generated being the result of thermal heating, and this assessment may apply to Brady's design as well?  (According to Doctor Rodal and Frobnicat).

Though Mulletron, at least for the time being is still exploring Quantum options.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/09/2014 11:34 pm
Ok...so if I correctly grasp the last page or two worth of posts(doubtful), the 'EM Drive' as tested by Eagleworks, is probably bogus, with the 'thrust' generated being the result of thermal heating, and this assessment may apply to Brady's design as well?  (According to Doctor Rodal and Frobnicat).

Though Mulletron, at least for the time being is still exploring Quantum options.

A lot of sceptics said it was bogus, probably thermal or so. The authors insisted that it couldn't be thermal because of the steep step of measured thrust when powering the device. They probably didn't make any attempt at quantifying that (busy as they were to improve the thruster's design and nurturing wild speculations) and relied on visual aspect only.

On more critical eye and a serious beginning of quantitative analysis (not of vacuous quantization) appears the measurement system has too much inertia to easily ascertain the steepness of the steps and that the heating (or transition to constant heating rate) might be faster than intuition would say.

Proof of thermal effect is not done, at this stage we (Rodal and I) have only working hypothesis. What is almost sure is that the authors (experimenters) haven't convincingly discarded thermal effects as the main reason of what they measured. Until we (or someone else) comes with a complete viable thermal scenario, if one is to judge the probability of the "anomalous thrust" being bogus : what is the more probable between an overlooked thermal effect and an interaction between photons and vacuum zero point energy that allows for an unlimited energy source ? ( Because, and I wont prove that again and again, whatever the theory, it is just plain impossible to have "cheap momentum" at 1N/kW and not have "free energy", cant have one and not the other. Having both would be great.)

No wait, this is reverse, we are not the paid researchers here. They should do the work of proving correctly this is not a thermal effect, then we could consider the possibility it is something less conventional. Unless they do prove this is not thermal, this is probably thermal and bogus indeed. We should not get habituated to this poor level of justifications. Because extraordinary claims...

Sorry, I don't want to be mean like that. Really, I rather have a sympathy for maverick types. But the more we dig into this and the more it shows not only bogus but deceptive. I'm still under the shock of  "initial minus final"  to show how an innocent ion thruster would violate energy conservation as much as a Q thruster would. When I see people doing such injustice to innocent little ion thrusters I just get mad.
Title: Re: EM Drive Developments
Post by: aero on 11/10/2014 12:34 am
@Rodal - Does that level of heating give an energy balance in the end? That is, ALL of the energy goes somewhere, does it all go into heating per your calculations? Some of it must by conduction/convection go into the air to raise the pressure. And pretty quickly too, to fool the torsion balance.

Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 01:30 am
Consider my calculations as being what happens with the EM Drive in a vacuum, without air, which is also the assumption in Greg Egan's calculations http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html.

Next, as time permits, I will show what is the origin of the initial impulse (present in the NASA Eagleworks tests of the truncated cone). 

<<The NASA researchers insisted that it couldn't be thermal because of the steep step of measured thrust when powering the device>>

I will show that that assumption is incorrect because they didn't take into account  thermoelastic inertial coupling (which is usually neglected).


Frobnicat is workiing on a longer time response due to air heating that may explain Shawyer's and the rest of the Eagleworks response.

Patience...
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 07:15 am
I can see that the experimenters recognize heat contributions to the thrust plots. Look at the screen shot below. Table 2 isn't reporting 130uN of thrust for TE012, it is reporting just 55uN, after subtracting artifacts from the total 130uN peak.

They recognize da heat, which is apparent by that gentle rise over 30 seconds followed by a gentle fall over 30 seconds.

The sudden rise and sudden fall is the real thrust here.

I support all the exhaustive number crunching supporting heat as an artifact. That must also be applied equally to Cannae though. Bottom screenshot.

Conical frustums are better heaters than Cannaes are.

Especially for the Shawyer design but applicable to both designs, they've essentially built a quantum variant of a Nichols Radiometer inside with modifications, and a Crookes Radiometer outside in the test chamber, all rolled into one device.

Here's a proposed QV Nichols Radiometer experiment:
http://www.worldsci.org/pdf/abstracts/abstracts_6024.pdf
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 07:38 am
A mathsplosion starting page 8.

http://www.astronautical.org/sites/default/files/spacetimes/spacetimes_48-6.pdf

Dr. White is trying to use the QV to thrust against the QV. I can't see how this is possible. I don't see how you can squeeze or thrust or otherwise manipulate something that you can't "touch" per se.

But I know from the Lamb Shift, Casimir effect and other phenomena that the QV does interact with matter in a random and subtle manner. So we must stop trying to mess with the QV, and instead change how it "messes" with matter.

I really think this EMdrive may be sailing the Dirac Sea!
Title: Re: EM Drive Developments
Post by: frobnicat on 11/10/2014 09:04 am
I can see that the experimenters recognize heat contributions to the thrust plots. Look at the screen shot below. Table 2 isn't reporting 130uN of thrust for TE012, it is reporting just 55uN, after subtracting artifacts from the total 130uN peak.

They recognize da heat, which is apparent by that gentle rise over 30 seconds followed by a gentle fall over 30 seconds.

The sudden rise and sudden fall is the real thrust here.
.../...


If it were that sudden, why there is not the characteristic overshoot magnitude clearly visible for the calibration pulses (of similar magnitude) that are known to be "instantaneous" ?

You must see there is a huge difference between the result of rectangular force signals of calibration pulses vs thrusts pulses : the explanation is that for the later the rise is steep but not as steep. Still working on quantitative estimates but this is strongly hinting a time constant (time to asymptotically reach the plateau) that is likely much higher than anything electromagnetic in nature. Likely below 2 seconds but likely more than .1 s (analysis will tell).

Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 09:11 am
I can see that the experimenters recognize heat contributions to the thrust plots. Look at the screen shot below. Table 2 isn't reporting 130uN of thrust for TE012, it is reporting just 55uN, after subtracting artifacts from the total 130uN peak.

They recognize da heat, which is apparent by that gentle rise over 30 seconds followed by a gentle fall over 30 seconds.

The sudden rise and sudden fall is the real thrust here.
.../...


If it were that sudden, why there is not the characteristic overshoot magnitude clearly visible for the calibration pulses (of similar magnitude) that are known to be "instantaneous" ?

You must see there is a huge difference between the result of rectangular force signals of calibration pulses vs thrusts pulses : the explanation is that for the later the rise is steep but not as steep. Still working on quantitative estimates but this is strongly hinting a time constant (time to asymptotically reach the plateau) that is likely much higher than anything electromagnetic in nature. Likely below 2 seconds but likely more than .1 s (analysis will tell).

There is an overshoot with the "thrust" impulse. Blue circles below. Why do you feel it needs to be the same magnitude as the cal pulse overshoot? Do they share the same dynamics? I would say not.

In the screenshot below, why do you feel the blue bounces and green bounces should be equal? Do they share the same exact kinematics? Is the calibration system intended to match the kinematics of the test article? I think not. It is just to provide a stable known reference for force measurements. And to make sure the test bench is measuring the same every time. I wouldn't go out on that limb with such little info available. The test article and the calibration system overcome the inertia of the test rig in different ways. There's no need to throw pages of math at a problem where there is no information to support anything. We don't even know the mass of a single thing in that test chamber.

There isn't enough information to support such an exhaustive analysis because lack of knowledge leads to hasty assumptions, thus a bad result. The best we can get from this paper is the knowledge the thrust pulses rise and fall suddenly, just like the cal pulses. And that there is a "bounce." The fact that there is more or less bounce is inconsequential.


That kind of over nuking it analysis is tantamount to me trying to calculate how fast my car's windows roll up simply by reading a car advertisement in a magazine.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/10/2014 09:55 am
I can see that the experimenters recognize heat contributions to the thrust plots. Look at the screen shot below. Table 2 isn't reporting 130uN of thrust for TE012, it is reporting just 55uN, after subtracting artifacts from the total 130uN peak.

They recognize da heat, which is apparent by that gentle rise over 30 seconds followed by a gentle fall over 30 seconds.

The sudden rise and sudden fall is the real thrust here.
.../...


If it were that sudden, why there is not the characteristic overshoot magnitude clearly visible for the calibration pulses (of similar magnitude) that are known to be "instantaneous" ?

You must see there is a huge difference between the result of rectangular force signals of calibration pulses vs thrusts pulses : the explanation is that for the later the rise is steep but not as steep. Still working on quantitative estimates but this is strongly hinting a time constant (time to asymptotically reach the plateau) that is likely much higher than anything electromagnetic in nature. Likely below 2 seconds but likely more than .1 s (analysis will tell).

There is an overshoot with the "thrust" impulse. Why do you feel it needs to be the same magnitude as the cal pulse overshoot? Do they share the same dynamics? I would say not.

I would say yes. Those overshoot are the result of the response of the measurement system, which is the displacement of the beam of the balance, not of the excitation, which is a force imparted on the beam of the balance. So the calibration pulses and thrust pulses share the same dynamic because they share the same balance, if one is to make it ring in a particular way, then the other should make it ring in a similar fashion if it is to be of similar nature (as far as temporal evolution of imparted force is concerned).

What is reported in the curves is a measurement_function of the force signals, not the signals themselves.
So in one hand we have   measurement_function( cal_pulse(t) )
And in the other we have   measurement_function( thrust_pulse(t) )
The measurement_function is the same, it is given by the dynamics of the balance, not the mechanics of the pulses.

Clearly : 
cal_pulse(t) ≈  thrust_pulse(t)
=> measurement_function( cal_pulse(t) ) ≈ measurement_function( thrust_pulse(t) )

By contraposition (http://en.wikipedia.org/wiki/Contraposition) :
measurement_function( cal_pulse(t) ) measurement_function( thrust_pulse(t) )
=> cal_pulse(t)   thrust_pulse(t)

Why would a thrust imparted by electromagnetic coupling to something (aether, mach effect on local horizon, whatever) would be any different to a calibration force (of similar magnitude) given by electrostatic fins ? A real thrust (not an artefact) should be as "instantaneous" as the calibration pulses, so it should give the same kind (same allure) of response from the balance.

There are always caveats of course, if you want, maybe the power-on of the microwaves is not instantaneous. If the amplifier takes .2 s to get to full power then this mystery is explained. But this "undershoot" signature appears to occur more for the low power experiment (at 2.6 W) than for the higher power (around 16.8W) : this would be a natural parameter dependency for a thermal effect, while it would be a very contrived consequence of an amplifier power-on delay (the amp would take more time to reach nominal power when nominal power is lower).

Quote
The test article and the calibration system overcome the inertia of the test rig in different ways.

How ? Why ? Come on, that doesn't make sense. The point of application of the force may be a little different, but a force on a beam is a force on a beam. You are eating too much fringe science : inertia isn't to be "overcome" in different ways, there is just this   F = m*a thing that relate a force (whatever its origin) to an effect (an acceleration).

Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 09:56 am
Well it does take time for energy to build up in the cavity. The fact that there is a sudden rise and fall when rf is on and off is enough. Just like the cal pulses suddenly rise and fall. It is obvious that the impulse from the cal system acts more quickly than the test article. It is an instant on/off device. The cavity needs a tiny bit more time. Now do you see why I said that the cal system and the test article overcome the inertia of the test rig in different ways? There isn't enough granularity in those photos to discern between those times. The rise times of the thrust pulses and cal pulses are nearly identical.

This isn't fringe science, just common sense. Common sense first, then math. Not the other way around.

What is important, once you take into account of heating/cooling, is if you draw a line through middle of the leading and trailing edges (blue lines), you get a mirror image. That means that both the cal system and the test article are symmetrically effecting/being effected by the magnetic damper around back. And they are.

There isn't a problem here.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/10/2014 10:04 am
Well it does take time for energy to build up in the cavity.

Yes it does. On the order of Q * typical_length / c = 20000 * .3 / 300000000 = 20 µs
We are not talking about a delay bellow ms here. Admittedly we must provide a clear quantitative estimation but there is no question that the difference in overshoot is due to way higher than 1ms delay in rise (and fall) times.

Quote
The fact that there is a sudden rise and fall when rf is on and off is enough.

That is what the authors of the paper want to believe. And want us to believe. Don't believe, check. All those words are self-reassuring. If those differences in overshoot are inconsequential then it is not a waste of time to show how and why they are inconsequential. In my eye they are not inconsequential, so I will check, and see that there is a difference in rise time, and that the thruster is not "an instant on/off device", as you admit yourself. And there maybe we wont agree on the fact that it is consequential that the thruster takes 100ms to reach it's plateau. There is enough information in those curves to falsify all electromagnetic "propellentless" explanations.
Title: Re: EM Drive Developments
Post by: RotoSequence on 11/10/2014 10:13 am
Well it does take time for energy to build up in the cavity.

Yes it does. On the order of Q * typical_length / c = 20000 * .3 / 300000000 = 20 µs
We are not talking about a delay bellow ms here. Admittedly we must provide a clear quantitative estimation but there is no question that the difference in overshoot is due to way higher than 1ms delay in rise (and fall) times.

For clarity's sake, you're saying that the impulse delays could be caused by the amplifier warming up, and the undershoot at lower power levels, rather than higher level ones, is evidence of that?
Title: Re: EM Drive Developments
Post by: frobnicat on 11/10/2014 10:27 am
Well it does take time for energy to build up in the cavity.

Yes it does. On the order of Q * typical_length / c = 20000 * .3 / 300000000 = 20 µs
We are not talking about a delay bellow ms here. Admittedly we must provide a clear quantitative estimation but there is no question that the difference in overshoot is due to way higher than 1ms delay in rise (and fall) times.

For clarity's sake, you're saying that the impulse delays could be caused by the amplifier warming up, and the undershoot at lower power levels, rather than higher level ones, is evidence of that?

The "undershoot" signature appears to occur more for the low power experiment (at 2.6 W) than for the higher power (around 16.8W) :

- This would be a natural parameter dependency for a thermal effect.
Meaning the thermal artefacts (be it at the place of the amplifier or the thruster) takes longer to reach a plateau at lower powers, so that thermal explanations are in good qualitative agreement.

- while it would be a very contrived consequence of an amplifier power-on delay
Meaning that if we had a real effect, with no delays, but the microwave power was fed to the thruster in a less than ideal way because the amplifier takes some time to reach nominal power (because of charging capacitors in the first stages for instance), then it becomes very hard to see why it would take longer time to reach a plateau of lower power (for the amplifier).

Avoid talking about "warming-up" of the amplifier because it risks confusion of the two different things.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 10:31 am
I'm saying, that you're basing all this on a cal pulse produced from a system from which you know very little. You don't know how much power it is capable of delivering to the fins 1, and you don't know the mass of the test rig 2.

You're assuming that the designers of the experiment intended for the rise and falls to be the same between the test article and the cal system. Why? I don't know. The force delivered to the LDS by the cal system and the test article are from two different kinds of devices. So the only thing in common is quantitatively they each deliver a force to be measured. The kinematics of how that force is provided is different.

Cal system: Voltage applied to fins (power?), pretty much instant impulse (sharp rise), result measured slowed by inertia of test rig.

Test article: Rf building up in cavity, slower to respond impulse (still sharp rise), result measured slowed by same inertia of test rig.

We can calculate all day how long it takes for energy to build up in the cavity/q but it is inconsequential. Doesn't help. It's been done on this forum. You can't even see microseconds on the graph.

Quote
The "undershoot" signature appears to occur more for the low power experiment (at 2.6 W) than for the higher power (around 16.8W) :

- This would be a natural parameter dependency for a thermal effect.
Meaning the thermal artefacts (be it at the place of the amplifier or the thruster) takes longer to reach a plateau at lower powers, so that thermal explanations are in good qualitative agreement.

Well I'm on board qualitatively with thermal effects. There ARE thermal effects. No issues here. You can see thermal effects with every gentle slope.......Electromagnetic artifacts create sharply rising slopes.

As far as the bolded quote above. There is no more or less overshoot happening across the tests. Attached is a screen shot that shows the test article bounces more, less, and close to equally to the same bounce from the cal pulse. The important take away is that there is always a bounce and that the bounces are consistent.

You're in France right? I'm in Italy (not Italian though). We're up arguing before the rest of the group wakes up.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 11:15 am
1) It is incorrect to state that we don't know the mass on the inverted torsional pendulum.  Paul March gave us the mass.

2) The natural frequency of the inverted torsional pendulum is dependent on the mass on the pendulum.

3) The natural frequency of the inverted torsional pendulum can be extracted by Fourier Transform of the data, as we did, and it checks. 

4) Paul March also gave us the natural frequency of the inverted pendulum, and it checks with the above information.

5) Paul March also informed us that the mass and its positional arrangement on the inverted pendulum did not change from test to test.

6) If the mass, moment of inertia and stiffness didn't change from test to test, then the natural frequency should not change from test to test.  The fact that it didn't change is confirmed by the Fourier Transform of the data.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 11:39 am
Quote
1) Someone is stating that we don't know the mass on the inverted torsional pendulum.  This is an incorrect statement.  Paul March gave us the mass.

Well I really need the mass of the test articles. The mass of the pendulum and the test articles would be so useful. Was that provided?

You see, if I had the mass of the test article, I could work out all the other math, like Delta V and put a check on that specific impulse I found.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 12:05 pm
Quote
1) Someone is stating that we don't know the mass on the inverted torsional pendulum.  This is an incorrect statement.  Paul March gave us the mass.

Well I really need the mass of the test articles. The mass of the pendulum and the test articles would be so useful. Was that provided?

You see, if I had the mass of the test article, I could work out all the other math, like Delta V and put a check on that specific impulse I found.

25 pound total load on the torque pendulum arm
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 12:18 pm
Yes the comments from 22 October say that is the MAX supportable load on the arm:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275117#msg1275117
Quote
"And I just verified that Paul March wrote that the supported mass was a maximum of 25 lbm.  That is 11.3398 kgm"

That came from here:

http://nextbigfuture.com/2014/09/paul-march-is-providing-more.html

"Each bearing block is rated for ~25.0 Lb of vertical mass load, so we nominally restrict ourselves to a 25 pound total load limit on the torque pendulum arm to give ourselves a 100% support mass margin."

Ok so it can hold 25 pounds......But what are the actual masses of the test articles or the pendulum?
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 12:33 pm
1) Paul March posted the information in this  NASASpaceFlight.com forum and not in the Next big future webpage.  Next big future just copied the information from this forum into their webpage.  They recognized this by stating at the outset:  "Paul March ... is providing information about the experiments on the NASA spaceflight forum." There is no need to give any credit to Next Big Future, on the contrary, it is Next Big Future that owes credit to NASASpaceFlight.com and to Paul March.  NASASpaceFlight forum is the true source of this mass information.

2) I do not recall information for mass of individual items.  The total mass, dimensions and stiffness is what is required for the lowest natural frequency of the pendulum.   Individual motion of items on the pendulum can only occur at much higher frequencies (and lower amplitudes) than the lowest natural frequency of the pendulum
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 12:42 pm
1) Paul March posted the information in this  NASASpaceFlight.com forum and not in the Next big future webpage.  Next big future just copied the information from this forum into their webpage.  They recognized this by stating at the outset:  "Paul March ... is providing information about the experiments on the NASA spaceflight forum." There is no need to give any credit to Next Big Future, on the contrary, it is Next Big Future that owes credit to NASASpaceFlight.com and to Paul March.  NASASpaceFlight forum is the true source of this mass information.

2) I do not recall information for mass of individual items.  The total mass, dimensions and stiffness is what is required for the lowest natural frequency of the pendulum.   Individual motion of items on the pendulum can only occur at much higher frequencies (and lower amplitudes) than the lowest natural frequency of the pendulum

Are you using that 25lb figure as total mass? Because that is just how much weight it can hold. That isn't the mass of anything.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 12:54 pm
1) Paul March posted the information in this  NASASpaceFlight.com forum and not in the Next big future webpage.  Next big future just copied the information from this forum into their webpage.  They recognized this by stating at the outset:  "Paul March ... is providing information about the experiments on the NASA spaceflight forum." There is no need to give any credit to Next Big Future, on the contrary, it is Next Big Future that owes credit to NASASpaceFlight.com and to Paul March.  NASASpaceFlight forum is the true source of this mass information.

2) I do not recall information for mass of individual items.  The total mass, dimensions and stiffness is what is required for the lowest natural frequency of the pendulum.   Individual motion of items on the pendulum can only occur at much higher frequencies (and lower amplitudes) than the lowest natural frequency of the pendulum

Are you using that 25lb figure as total mass? Because that is just how much weight it can hold. That isn't the mass of anything.

For context and meaning read the original statements from Paul March in NASASpaceFlightForum instead of referring to NextBigFuture. 

Paul March stated: 

Quote
we nominally restrict ourselves to a 25 pound total load limit on the torque pendulum arm

This total mass (25 lb) checks with the natural frequency provided by Paul March and with the natural frequency obtained by Fourier Transform of the data.  A lower total mass than 25 lb leads to higher natural frequencies, since the natural frequency is proportional to the inverse square root of the total mass.

And how much lower than 25 lb do you think that the total mass on the pendulum would be and why?

Were you to claim that the total mass would be be 12 lb for example, the natural frequency would be 44% higher.  Were you to claim that the total mass would be 2.5 lbs the natural frequency would be 3 times higher.  Do you really think that the total mass on the pendulum is only 2.5 lbs ?  How would that agree with common sense (you were posting to Frobnicat to use common sense previously and now you are questioning that the total mass on the pendulum can be orders of magnitude lower than 25 lbs?)
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 01:15 pm
This quote:

Quote
we nominally restrict ourselves to a 25 pound total load limit on the torque pendulum arm

is from NBF dated 11Sep14.

Where is it on here from March for sake of clarity?

Your comments:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275117#msg1275117

22Oct14.

Indeed NBF references NSF, but it is about electrical issues. First linked to. But they have slides from March which contain the mechanical data, which weren't posted here.
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1254155#msg1254155

I don't want to start a war over this, but I remain correct when I asserted that we don't know the mass of the things inside the test chamber. So how can we blindly throw numbers at them? We can't just say 25lb/11.34kg based off of the max weight it can hold.

I'm not the first to comment on here about blindly throwing numbers at assumptions. It ends up being a waste of time and sends everyone on a tangent based on bad info.

Quote
And how much lower than 25 lb do you think that the total mass on the pendulum would be and why?

There is no "think" about this, just what the mass actually really is.

You can't pass off quantitative results derived from qualitative data.


All you can ethically do is make rough approximations, based on the lack of data which is available; which is what I do around here most of the time......and for good reason.

Nuff said.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 01:23 pm
This quote:

Quote
we nominally restrict ourselves to a 25 pound total load limit on the torque pendulum arm

is from NBF dated 11Sep14.

Where is it on here from March for sake of clarity?

Your comments:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275117#msg1275117

22Oct14.

Indeed NBF references NSF, but it is about electrical issues. First linked to. But they have slides from March which contain the mechanical data, which weren't posted here.

I don't want to start a war over this, but I remain correct when I asserted that we don't know the mass of the things inside the test chamber. So how can we blindly throw numbers at them? We can't just say 25lb/11.34kg based off of the max weight it can hold.

I'm not the first to comment on here about blindly throwing numbers at assumptions. It ends up being a waste of time and sends everyone on a tangent based on bad info.

Quote
And how much lower than 25 lb do you think that the total mass on the pendulum would be and why?

There is no "think" about this, just what the mass actually really is.

You can't pass off quantitative results derived from qualitative data.

You sermonize to Frobnicat about using common sense and now you maintain that the total load on the pendulum could be 2 lb instead of 25 lb?  I don't think that common sense says that the total mass could be 2 lb

What it looks to me is that you overlooked the fact that natural frequencies are weakly dependent on mass (it goes like the square root of mass), so that small changes in mass make a much smaller difference to the natural frequency.   

Just admit it.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 01:29 pm
We don't know the mass. That is the point. I'm not being a meanie or a negative nancy. I'm sticking to the facts. I'm being practical.

The methodology you describe is like guessing how massive my truck is based on its cargo capacity.
And then running with that number.

If you had the data, you'd be right.

I'm finished here.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 01:30 pm
We don't know the mass. That is the point. I don't mean to be mean. I'm sticking to the facts.

The methodology you describe is like guessing how massive my truck is based on its cargo capacity.

If you had the data, you'd be right.

I'm finished here.

Does common sense (see attached picture) show that the total mass on the pendulum could be a few ounces instead of ~<25 lb ?

Do you understand that small changes in total mass do not affect the natural frequency very much because the natural frequency goes like the square root of the mass? 

A 10% change in mass makes only a 5% difference in natural frequency.
A 20% change in mass makes only a 10% difference in natural frequency.

Do you understand that we have the time response and that one can obtain the natural frequency by performing a Fourier Transform of the response without having any knowledge of the mass?  (that's what we also have here and you neglected to mention in the truck example)
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 02:01 pm
I don't care about the pendulum frequency. The amplitudes are important. The force required to move a pendulum of x mass (in the first place) varies wildly depending on mass. The kinetic energy and potential energy of a moving pendulum varies wildly depending on the mass of the pendulum as well.

None of my screen shots previously, pointing out the "bounce" had anything to do with frequency, but the amplitudes were different.

Here's something for the folks out there to play with. Take 2 pendulums, give them wildly different masses. Set them in opposite motion. Timing is everything......You'll see frequency is unaffected by mass, yet PE and KE are. Also getting the pendulum to move in the first place is very much dependent on mass. F=MA as they say.
Let your computer do the work for you.....

This author never made any assertions of the mass of anything. Simply we don't know the masses of anything.

http://phet.colorado.edu/sims/pendulum-lab/pendulum-lab_en.html
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 02:08 pm
I don't care about the pendulum frequency. The amplitudes are important. The force required to move a pendulum of x mass (in the first place) varies wildly depending on mass. The kinetic energy and potential energy of a moving pendulum varies wildly depending on the mass of the pendulum as well.

None of my screen shots previously, pointing out the "bounce" had anything to do with frequency, but the amplitudes were different.

Here's something for the folks out there to play with. Take 2 pendulums, give them wildly different masses. Set them in opposite motion. Timing is everything......You'll see frequency is unaffected by mass, yet PE and KE are. Also getting the pendulum to move in the first place is very much dependent on mass. F=MA as they say.
Let your computer do the work for you.....

This author never made any assertions of the mass of anything. Simply we don't know the masses of anything.

http://phet.colorado.edu/sims/pendulum-lab/pendulum-lab_en.html

Wrong!

The transient amplitude of the torsional pendulum is dictated by the static deflection (the ratio of the applied force to the stiffness) and most importantly by the ratio of the exciting frequency to the natural frequency of the system !

You are arguing about the dynamics and you write that you "don't care about the pendulum frequency" ?

The magnitude of the transient response which results from an impulse depends on the ratio of the impulsive load duration to the inverse of the natural frequency (the natural period).

The "folks" here know that the equation is not F=ma=m d2x/dt2, it is

m d2x/dt2 +c dx/dt + k x = F(t)

The "folks" here know that the response of this system depends on the natural frequency !


Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 03:18 pm
While in the shower, I realized that I am being drawn into a straw man argument about frequency, when my first assertions were about the measured "bounce" of the test article vs the cal system. Did I mention that we're not dealing with an already oscillating pendulum. The "noise" oscillations are clearly visible in the screenshot below, and the kinetic energy to be overcome from those oscillations is inconsequential because the table is isolated from the rest of the earth. (Gulf of Mexico, footsteps, and car crashes are isolated from measurement.) It is inconsequential because the "thrust" is clearly visible above the noise floor. No further treatment is required to suss that signal out.

Even after demonstrating one way, that is simple and elegant (the website) that a change of mass suspended from a pendulum does not affect the frequency. This was chosen to not confuse bystanders or using howlers. http://en.wikipedia.org/wiki/Mathematical_fallacy#Howlers. Such as using formulas below:
m d2x/dt2 +c dx/dt + k x = F(t)

Which should be this anyway: m (d2x/dt2)+c(dx/dt)+kx =F(t)

And introducing conditions which aren't present, such as an already oscillating pendulum.

That formula you posted above is a mass spring damper equation of an oscillator.

This isn't personal. Just practical perspective. We're not trying to pick out unclear signals from noise here, like it is SETI.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 03:28 pm
While in the shower, I realized that I am being drawn into a straw man argument about frequency, when my first assertions were about the measured "bounce" of the test article vs the cal system. Did I mention that we're not dealing with an already oscillating pendulum. The "noise" oscillations are clearly visible in the screenshot below, and the kinetic energy to be overcome from those oscillations is inconsequential because the table is isolated from the rest of the earth. (Gulf of Mexico, footsteps, and car crashes are isolated from measurement.) It is inconsequential because the "thrust" is clearly visible above the noise floor. No further treatment is required to suss that signal out.

Even after demonstrating one way, that is simple and elegant (the website) that a change of mass suspended from a pendulum does not affect the frequency. This was chosen to not confuse bystanders or using howlers. http://en.wikipedia.org/wiki/Mathematical_fallacy#Howlers. Such as using formulas below:
m d2x/dt2 +c dx/dt + k x = F(t)

Which should be this anyway: m (d2x/dt2)+c(dx/dt)+kx =F(t)

And introducing conditions which aren't present, such as an already oscillating pendulum.

That formula you posted above is a mass spring damper equation of an oscillator.

Previously you posted that you "don't care about the pendulum frequency" in order to determine the dynamic response  :)

Now you post that "a change of mass suspended from a pendulum does not affect the frequency"  :)

And your statements about "an already oscillating pendulum"? as if the statements I posted before have anything to do with an already oscillating pendulum ?  :)

Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 03:30 pm
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1286223#msg1286223

Nope.

You brought up frequency later and I told you I don't care about frequency.

I don't care about frequency because of the mass independence of pendulum period.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 03:34 pm
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1286223#msg1286223

Nope.

You brought up frequency and I told you I don't care about frequency.

I don't care about frequency because of the mass independence of pendulum period.

Now you are stating that the natural frequency of the NASA Eagleworks pendulum used for the "Anomalous " report does not depend on the mass?  :)   ::)
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 03:45 pm
http://ocw.mit.edu/high-school/physics/demonstrations-on-video/oscillations-gravitation/pendulum-periods/

I'm not arguing anymore.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 03:49 pm
http://ocw.mit.edu/high-school/physics/demonstrations-on-video/oscillations-gravitation/pendulum-periods/

46:30 in.

I'm not arguing anymore.

You have shown that you don't understand the dynamics of the NASA Eagleworks pendulum at all.

NASA Eagleworks for the "Abnormal ..." report that we are discussing on this EM Drive thread used a torsional pendulum. 

Read the title of the report we are discussing:  "Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum"  http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

The natural frequency of the pendulum that NASA Eagleworks used depends on the square root of the rotary moment of inertia and hence it depends on the square root of the mass.


It is not possible to understand the dynamics of the EM Drive measurement if one doesn't understand the dynamics of the torsional pendulum that the EM Drive is attached to.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/10/2014 04:04 pm
What the author is discussing does not apply to the EM drives researched by NASA Eagleworks because the materials used are isotropic.  (Copper in all cases and in some cases Teflon or Polyethylene dielectrics -injection molded-)
IIRC, some of the cryogenically injection molded metal glass alloys are anisotropic as they align with strong fields when injection molded.  See the stuff at liquidmetal.com for this.  Additionally, there are ways to force anisotropy even on sputtered films of copper and the like.  Sputtering anisotropic films is a trade secret carefully guarded within its industry but it's something some people know how to do.  It's done with AiN on a daily basis.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/10/2014 04:10 pm
Quote
The EM Drives tested by NASA Eagleworks do not satisfy the anisotropy  (mechanical and electromagnetic) conditions required by the author. What the author discusses is not applicable to explain the measurements at NASA Eagleworks.

@Mulletron - That does not mean necessarily that you're on the wrong track, just that our current understanding is not sufficiently complete to attribute the measured force. (I know, that sounds like gobbally-gook)  :)
There is a way to make these polymers anisotropic in bulk.  I read some years ago and just did a quick search, it concerns stretching the material.  There was some buzz years ago that the new electroactive polymers being considered for energy conversion and springwalker style powered armor benefit hugely from anisotropy.  Quick search came up with this if you have an interest I'm sure you can do a better one.

http://pubs.acs.org/doi/abs/10.1021/cm052511w
Well I accepted the challenge. It took me 30 minutes to find that both extruded PE and PTFE solidify to a semicrystalline structure. Therefore they are anisotropic. If they were amorphous, they'd be isotropic.

So I've established that the materials used in the the Brady et al test campaigns are both chiral polymers and they are both anisotropic due to their semicrystalline structure.

I'll save you the trip to the Oracle this time.
See for yourself. Just google crystallization of polymers.
Also google chiral polymer tacticity.

A neat resource I found:
https://www.nde-ed.org/EducationResources/CommunityCollege/Materials/Structure/anisotropy.htm

Also two exciting words: lamella twisting, here's helical chirality in PE
http://www.esrf.eu/UsersAndScience/Publications/Highlights/2011/scm/scm4

Chirality=proven true
mechanical anisotropy=proven true
electromagnetic or magnetic anisotropy=not proven true, this is where spontaneous pt symmetry breaking comes in. Been working on this one for a while.

Neither PTFE (Tefflon) or Polyethylene are mechanically or electromagnetically anisotropic in bulk.  I have measured their directional properties with Dielectrometry, NMR, TMA, DTMA and with MTS.  Semi crystallinity in thermoplastic polymers is not at all like well ordered crystalline metals.  The "crystalline" regions have independent domains oriented randomly throughout the polymer.  Extrusion anisotropy takes place at the exterior surface of the extruded rod in regions of very high shear near the extruder walls.  The interior of the extruded rod is isotropic.   Injection molded PTFE and PE are isotropic due to the random orientation produced during the injection molded process.

There are proprietary manufacturing methods to produce mechanically , electromagnetically and  optically anisotropic polymers, for example when making optically anisotropic polarized lenses.  One would not use extrusion to make such lenses.    It is much easier to attain preferred orientation, overall-anisotropic materials for thin polymer sheets or for very small diameter filaments.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 04:15 pm
Quote
The EM Drives tested by NASA Eagleworks do not satisfy the anisotropy  (mechanical and electromagnetic) conditions required by the author. What the author discusses is not applicable to explain the measurements at NASA Eagleworks.

@Mulletron - That does not mean necessarily that you're on the wrong track, just that our current understanding is not sufficiently complete to attribute the measured force. (I know, that sounds like gobbally-gook)  :)
There is a way to make these polymers anisotropic in bulk.  I read some years ago and just did a quick search, it concerns stretching the material.  There was some buzz years ago that the new electroactive polymers being considered for energy conversion and springwalker style powered armor benefit hugely from anisotropy.  Quick search came up with this if you have an interest I'm sure you can do a better one.

http://pubs.acs.org/doi/abs/10.1021/cm052511w
Well I accepted the challenge. It took me 30 minutes to find that both extruded PE and PTFE solidify to a semicrystalline structure. Therefore they are anisotropic. If they were amorphous, they'd be isotropic.

So I've established that the materials used in the the Brady et al test campaigns are both chiral polymers and they are both anisotropic due to their semicrystalline structure.

I'll save you the trip to the Oracle this time.
See for yourself. Just google crystallization of polymers.
Also google chiral polymer tacticity.

A neat resource I found:
https://www.nde-ed.org/EducationResources/CommunityCollege/Materials/Structure/anisotropy.htm

Also two exciting words: lamella twisting, here's helical chirality in PE
http://www.esrf.eu/UsersAndScience/Publications/Highlights/2011/scm/scm4

Chirality=proven true
mechanical anisotropy=proven true
electromagnetic or magnetic anisotropy=not proven true, this is where spontaneous pt symmetry breaking comes in. Been working on this one for a while.

Neither PTFE (Tefflon) or Polyethylene are mechanically or electromagnetically anisotropic in bulk.  I have measured their directional properties with Dielectrometry, NMR, TMA, DTMA and with MTS.  Semi crystallinity in thermoplastic polymers is not at all like well ordered crystalline metals.  The "crystalline" regions have independent domains oriented randomly throughout the polymer.  Extrusion anisotropy takes place at the exterior surface of the extruded rod in regions of very high shear near the extruder walls.  The interior of the extruded rod is isotropic.   Injection molded PTFE and PE are isotropic due to the random orientation produced during the injection molded process.

There are proprietary manufacturing methods to produce mechanically , electromagnetically and  optically anisotropic polymers, for example when making optically anisotropic polarized lenses.  One would not use extrusion to make such lenses.    It is much easier to attain preferred orientation, overall-anisotropic materials for thin polymer sheets or for very small diameter filaments.

Stretching the polymer to produce semi-crystalline anisotropic polymers (something I was involved in my professional life in manufacturing, numerical analysis and R&D) works well for filaments and thin films.  Not for a thick polymer.  As an example, Kevlar is a liquid crystalline polymer.  To make strongly aligned, and fairly free of defects, one makes Kevlar fibers.  To make a thick aerospace product one may use a Kevlar-fiber reinforced composite but not a thick solid bulk Kevlar product (which doesn't exist for Kevlar because it would have undesirable poor properties for the reasons previously addressed).
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/10/2014 04:17 pm
No wait, this is reverse, we are not the paid researchers here. They should do the work of proving correctly this is not a thermal effect, then we could consider the possibility it is something less conventional. Unless they do prove this is not thermal, this is probably thermal and bogus indeed. We should not get habituated to this poor level of justifications. Because extraordinary claims...
Agreed but lets remember this is a conference paper, not a peer review paper, and they rushed to get to market with this, not even doing a statistically valid series of runs.  It is because of this though, that their funding was extended another 6 months, so not hard to understand.

It's science.  The truth will eventually win out regardless what ion drives are molested in the interim.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 04:21 pm
Even with the straw man, leading to a debate over frequency. One cannot make predictions about the dynamics of the test rig without knowing the masses of the pendulum or the test articles.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/10/2014 04:33 pm
Stretching the material to produce semi-crystalline anisotropic polymers (something I was involved in my professional life in manufacturing, numerical analysis and R&D) works well for filaments and thin films.  Not for a polymer several inches thick.  As an example, Kevlar is a liquid crystalline polymer.  To make strongly aligned, and fairly free of defects, one makes Kevlar fibers.  To make a thick aerospace product one may use a Kevlar-fiber reinforced composite but not a inches thick solid bulk Kevlar product (which doesn't exist because it is undesirable).
It was my understanding (and it's some years since I studied this) that these are all electrostrictors, not piezoactive; so not able to do power generation since electrostriction is not reversible.  (Also not rigid enough for VHF, UHF and microwave frequencies, so they're useless for M-E tech.)  So were you working on the polymer actuator powered personal armor from the old Springwalker/Land Warrior program?  That is such cool tech!
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 04:37 pm
Stretching the material to produce semi-crystalline anisotropic polymers (something I was involved in my professional life in manufacturing, numerical analysis and R&D) works well for filaments and thin films.  Not for a polymer several inches thick.  As an example, Kevlar is a liquid crystalline polymer.  To make strongly aligned, and fairly free of defects, one makes Kevlar fibers.  To make a thick aerospace product one may use a Kevlar-fiber reinforced composite but not a inches thick solid bulk Kevlar product (which doesn't exist because it is undesirable).
I usually draw the distinction between thin films and bulk, but I'm sure you can draw the distinction between thick films and bulk if you like.

It was my understanding (and it's some years since I studied this) that these are all electrostrictors, not piezoactive; so not able to do power generation since electrostriction is not reversible.  (Also not rigid enough for VHF, UHF and microwave frequencies, so they're useless for M-E tech.)  So were you working on the polymer actuator powered personal armor from the old Springwalker/Land Warrior program?  That is such cool tech!

Rather than discussing our involvement in DoD projects, we better focus on the thread.  The discussion of anisotropy that you are referring to was motivated by Mulletron who has multiple posts advocating that the EM Drive measurements may be due to the Quantum Vacuum transferring momentum to the polymers used as a dielectric in the EM Drives.  (Specifically because of polymer chirality).

Is this (Quantum Vacuum transferring momentum to the polymers used as a dielectric in the EM Drives) something you agree with Ron?  Are you advocating that by stretching the dielectric polymer, this will enable the Quantum Vacuum to transfer momentum to the dielectric and serve as a means of EM Drive propulsion?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/10/2014 04:51 pm
The discussion of anisotropy that you are referring to was motivated by Mulletron who has multiple posts advocating that the EM Drive measurements may be due to the Quantum Vacuum transferring momentum to the polymers used as a dielectric in the EM Drives.
That would be interesting if things without inertial mass could transfer momentum, but they can't; so obviously that notion is wrong.

Springwalker was not classified.  I have friends at DoD who speak about it.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 09:26 pm
Decided to argue this time with the correct analogy, not neglecting we're dealing with a torsion pendulum:

Using similar methodology described starting at the 33 minute mark:
http://www.youtube.com/watch?v=5fLGcHUkd8Y

I decided to do some math problems to calculate the moment of inertia (Icm) of a rod 1 meter long with a mass of 1, 5.5, and 11 kg. (Range between 2.2 and ~24 pounds)
Moments of inertia:
1kg rod: I=.0833kg m2
5.5kg rod I=.4583kg m2
11kg rod I=.9166kg m2

From there I used those results to calculate a torsion pendulum oscillation period using the following constants: 1 meter length of suspension wire k=1Nm2
Oscillation periods:
1kg rod: 1.81 seconds
5.5kg rod: 4.25 seconds
11kg rod: 6 seconds

The point of this is to demonstrate that mass does make a dramatic difference in calculating moment of inertia and period of a torsion pendulum.



Title: Re: EM Drive Developments
Post by: RotoSequence on 11/10/2014 09:54 pm
I think I'm with Mulletron on this one. We seem to have gotten into some sort of pissing match for no good reason, and I think a good point has been raised:
We don't actually know the test mass of the assembly, just the weight limit that the experimenters confined themselves to. As much as I can tell, with no background in the relevant fields, different weights will affect the dynamics of the assembly, and a dynamic analysis that uses 25 pounds as the mass cannot be assumed to be definitive. "Try" doesn't eliminate the possibility that the weight exceeded 25 pounds.
Title: Re: EM Drive Developments
Post by: Rodal on 11/10/2014 10:24 pm
I think I'm with Mulletron on this one. We seem to have gotten into some sort of pissing match for no good reason, and I think a good point has been raised:
We don't actually know the test mass of the assembly, just the weight limit that the experimenters confined themselves to. As much as I can tell, with no background in the relevant fields, different weights will affect the dynamics of the assembly, and a dynamic analysis that uses 25 pounds as the mass cannot be assumed to be definitive. "Try" doesn't eliminate the possibility that the weight exceeded 25 pounds.
1) The dynamic response of this structure (the EM Drive on the torsional pendulum) is governed by the ratio of the excitation frequency to the natural frequencies of the structure.  If one doesn't understand that the dynamic response is governed by the natural frequencies of the structure, one cannot hope to understand the dynamics of the response.

2) Mulletron stated that he didn't care about the natural frequency of the pendulum

3) Mulletron was under the completely wrong understanding that the pendulum at NASA Eagleworks was a hanging pendulum, which has a natural frequency completely independent of the suspended mass.  This is completely incorrect.  NASA Eagleworks used a torsional pendulum whose natural frequency goes like the square root of the suspended mass.

4) Once one understands 1) that the dynamic response is governed by the natural frequency and 2) that the natural frequency goes like the square root of the mass,  then it is simple to make some comparisons:

Suspended Mass         % difference of natural frequency to the one for 25 lb (absolute value)


45 lb                             34%
40 lb                             26%
35 lb                             18%
30 lb                             10%
25 lb                             0%
20lb                              11%
15 lb                             23%
10 lb                             40%
 5 lb                              55%

NOTE: what is unknown is the lumped mass (the EM Drive) at a given distance from the center of rotation.  Hence the rotational moment of inertia has to be computed with masses of different magnitude at a fixed distance from the center of rotation.  Therefore in this case (lumped mass on the torsional arm) the moment of inertia is proportional to the lumped mass.

As one can see from the above, if the mass is not 25 lb, it makes a small difference to the natural frequency, and therefore to the response, because the dynamic response goes like the square root of the mass

5) Moreover, we don't need to know the mass to compute the dynamic response at all.
 One can obtain, as we did, the natural frequency of the system by using a Fourier Transform.

So a dynamic analysis of the EM Drive is not dependent on the assumption of the mass.

We know the natural frequency of the system from:

A) Paul March
B) Fourier transform of the "Anomalous " report data (which agrees with the value given by Paul March)
C) Frobnicat readily obtained the natural frequency of the Eagleworks pendulum just by visually looking at the plots
D) @notSoSureOfIt readily realized that one could obtain both the natural frequency and the damping from the Eagleworks results.

Title: Re: EM Drive Developments
Post by: RotoSequence on 11/10/2014 10:40 pm
Looks like I stand corrected, then. Thinking back to galloping gerty, I probably should have realized, or, remembered, that vibration frequencies are largely independent of the load, until the frequency of the load matches the frequency of the structure, and then it starts amplifying itself.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 10:45 pm
Quote
Mulletron was under the completely wrong understanding that the pendulum at NASA Eagleworks was a hanging pendulum

I hit you back with a bad analogy the first time. I didn't misunderstand the thing was a torsion pendulum (in the title of the paper). You are acknowledging there is a huge difference over 25 pounds. So that makes the error bars like 50 percent.

Now isn't the pendulum at equilibrium before and shortly after each test pulse? Where is the frequency important? The slope of the leading and trailing edge of the test pulses are nearly exactly the same as the cal pulses. Both are well above the noise floor. The frequency is reported to be .222hz/4.5 seconds. You can see it in the noise in the graphs in the paper and after each overshoot. It doesn't sit there and vibrate at the natural frequency forever. Because it is damped.
http://personal.cityu.edu.hk/~bsapplec/natural.htm
http://en.wikipedia.org/wiki/Natural_frequency
http://www.chegg.com/homework-help/definitions/natural-frequency-5
Title: Re: EM Drive Developments
Post by: frobnicat on 11/10/2014 10:52 pm
Yeah well, we already know the period of the harmonic oscillator better from the experimental graphs than from any calculations from parameters of the system like mass, length, stiffness (if experimenters cared to share).

My point was, I don't need to know the weight of a bell to know by hearing if it was hit by a hammer of hard material or by a hammer of soft material, especially when I have a recording of what it sounds like when hit by a hammer of steel and I know that the hammer of "mysterious material" imparts roughly the same recoil. I might not be able to tell apart tungsten from diamond, or rubber from soft wood, but I can tell apart hard from soft. Even if my audio sampling rate is in the same ballpark that the fundamental and in the same ball park as the time it takes for a rubber hammer to bounce, the ringing will make the difference (at equivalent recoil)

The thrust pulses sound rubber to me. It rings not like the hard rectangle pulse of the calibration pulse. This is a transient but this transient tells something important about the nature of the part that is not the gentle slope, this part that appears to be steep but is only so steep, that is not as steep as steel, so to speak. That part can't be "electromagnetic load time" because it is clearly above 1ms (otherwise it would appear hard) and anything electromagnetic goes the speed of light or near, so I don't see how you can discard my "20µs" three terms one liner as an all day long vacuous calculation : any effect that takes much more that 20µs, like for instance 100ms, to give full magnitude, is likely not a "real effect" (propellentless).

No hard ringing => no rise steeper than 100% full scale per 100ms
no rise steeper than 100% full scale per 100ms => no direct electromagnetic mediated force

Unless your theory would explain why the standing micro-waves fill the cavity at full magnitude in 20µs but would have to wait 100ms before reaching their plateau of momentum transfer to (or from) vacuum virtual particles. Seems very contrived to me. You can't handwave such a 100ms (or more) time constant away, like a suspect can't handwave away the fact that one of his hair was found on a crime scene as "hair splitting".

Hope this mention to prosecution will not entertain a certain level of paranoia : fact is, like for any rational investigation activity, hair splitting is also part of the job of science. And common sense is only in the eye of the beholder, but an eye is to use a microscope sometimes. I only say (with Rodal) : let's look at this difference of ringing with a microscope, let's split this hair and look if there is any thermal DNA in it. It will take some time (but not an indefinite amount of time) and we may find nothing convincing. But someone has to do it (the authors didn't, they just waved their hand in rectangle movements, that almost convinced me).

As an exit that would preserve the possibility of a real effect that has no such constraints of "non instantaneity" I propose the hypothesis that the microwave amplifier is the cause of the lack of punch of the signal, if the amplifier takes more than .1s to reach full power. That could be a natural explanation. Note I'm doing an effort here to find an hypothesis that would preserve the validity of the result in spite of the manifest difference relative to what would be expected from a clean rectangle force pulse (whatever it's source, Newtons imparted are not to remember what caused them). But, and it will be my last point, it appears there is less ringing (therefore less slope, therefore more time constant to reach plateau) at lower power levels (Brady c) than at higher power levels (Brady a and b). Granted, this is not that evident, I personally see a hint of that in the curves but would not say it is clear enough to make a definitive statement. It would be in disfavour of this "smooth power up" hypothesis as a source of the objective lack of punch of the transients.

You may disagree or find nonsense in a lot of things I just said. I find a lot of nonsense in what you said, this happens all the times in forums. Think we said what we had to say on the subject. Let us proceed. Wish you success with your personal line of research on the subject, can't help (for complete lack of knowledge in chirality and helicity and the such).

Now, will be time to scrap more data and reconstruct the signal with known procedures.
Found that thesis, a few of the introductory pages (15-17) are relevant.
Reconstructing force from harmonic motion (http://www.diva-portal.org/smash/get/diva2:622877/FULLTEXT01.pdf)
Equation 1.25 gives the Fourier transform of the Force signal from the inverse of the transfer function and the Fourier transform of the Displacement. Pretty simple and classic ! But later there are gory details like leakage of the discrete Fourier transform... mm, I'm afraid I get some Fourier leakage all over my shirt.

Oh, there is a nice citation in the thesis :

"An jeder Sache etwas zu sehen suchen, was noch niemand gesehen und
was noch niemand gedacht hat."

(To seek in everything something to see, which has never before been
seen nor sought.)

Georg Christoph Lichtenberg (1742-1799)
German mathematican and first professor
for experimental physics in Germany

Title: Re: EM Drive Developments
Post by: Mulletron on 11/10/2014 11:50 pm
Fun to play around with:
http://amrita.vlab.co.in/?sub=1&brch=280&sim=1518&cnt=4

A torsion pendulum sim.
Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 12:00 am
Fun to play around with:
http://amrita.vlab.co.in/?sub=1&brch=280&sim=1518&cnt=4

Nothing is suspended from a wire:

Quote from: Brady, March, White, et.al.
The pendulum arm pivots about two linear flexure bearings in a plane normal to gravitational acceleration. The flexure bearings provide an essentially-frictionless and hysteresis-free interface between the static test stand fixed structure and the dynamic pendulum arm. Test article force is measured by measuring the pendulum arm displacement and calculating the force via the flexure bearing spring constants that were determined during test facility setup

NASA Eagleworks has an inverted pendulum.

According to Paul March, NASA Eagleworks uses as a torsional spring two Riverhawk C-flex bearing blocks with torsional spring constant
(http://www.onesworks.com/wp-content/uploads/2011/02/SingleDouble.jpg)

(http://flexpivots.com/cantilevered-single-ended-pivot-bearings/) centered 2.38" above and below the centerline of the 24.00" long by 1.50" Faztek aluminum pendulum arm. The long end of the pendulum arm is 15.5" from the torque pendulum's center of rotation, which makes the other short-end of the pendulum arm 8.5" from the center of rotation. 





However, the NASA report shows a linear flexure bearing  http://flexpivots.com/linear-flexure-bearing/


Figure 1. Torsion Pendulum, Vacuum Chamber, and Linear Flexure Bearing
Title: Re: EM Drive Developments
Post by: Mulletron on 11/11/2014 12:36 am
Fun to play around with:
http://amrita.vlab.co.in/?sub=1&brch=280&sim=1518&cnt=4
Quote
Nothing is suspended from a wire:
We know. It is for theory.

Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/11/2014 12:48 am
Fun to play around with:
http://amrita.vlab.co.in/?sub=1&brch=280&sim=1518&cnt=4

Nothing is suspended from a wire:

Quote from: Brady, March, White, et.al.
The pendulum arm pivots about two linear flexure bearings in a plane normal to gravitational acceleration. The flexure bearings provide an essentially-frictionless and hysteresis-free interface between the static test stand fixed structure and the dynamic pendulum arm. Test article force is measured by measuring the pendulum arm displacement and calculating the force via the flexure bearing spring constants that were determined during test facility setup

NASA Eagleworks has an inverted pendulum.

According to Paul March, NASA Eagleworks uses as a torsional spring two Riverhawk C-flex bearing blocks with torsional spring constant
(http://www.onesworks.com/wp-content/uploads/2011/02/SingleDouble.jpg)

(http://flexpivots.com/cantilevered-single-ended-pivot-bearings/) centered 2.38" above and below the centerline of the 24.00" long by 1.50" Faztek aluminum pendulum arm. The long end of the pendulum arm is 15.5" from the torque pendulum's center of rotation, which makes the other short-end of the pendulum arm 8.5" from the center of rotation. 

However, the NASA report shows a linear flexure bearing  http://flexpivots.com/linear-flexure-bearing/

Well, the pic shows the bearing block anyway, not neccesarily the c-flex which would be trapped between the two halves of the block  (always used c-flex meself back then)
Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 12:52 am
Fun to play around with:
http://amrita.vlab.co.in/?sub=1&brch=280&sim=1518&cnt=4

Nothing is suspended from a wire:

Quote from: Brady, March, White, et.al.
The pendulum arm pivots about two linear flexure bearings in a plane normal to gravitational acceleration. The flexure bearings provide an essentially-frictionless and hysteresis-free interface between the static test stand fixed structure and the dynamic pendulum arm. Test article force is measured by measuring the pendulum arm displacement and calculating the force via the flexure bearing spring constants that were determined during test facility setup

NASA Eagleworks has an inverted pendulum.

According to Paul March, NASA Eagleworks uses as a torsional spring two Riverhawk C-flex bearing blocks with torsional spring constant
(http://www.onesworks.com/wp-content/uploads/2011/02/SingleDouble.jpg)

(http://flexpivots.com/cantilevered-single-ended-pivot-bearings/) centered 2.38" above and below the centerline of the 24.00" long by 1.50" Faztek aluminum pendulum arm. The long end of the pendulum arm is 15.5" from the torque pendulum's center of rotation, which makes the other short-end of the pendulum arm 8.5" from the center of rotation. 

However, the NASA report shows a linear flexure bearing  http://flexpivots.com/linear-flexure-bearing/

Well, the pic shows the bearing block anyway, not necc the c-flecs  (always used c-flex me self back then)

So, who are we to believe you think based on your experience and looking at the picture?  (Honest question, not a trick question)

The report that states linear bearing (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=620106;image)or Paul March that stated C-Flex bearing?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/11/2014 12:59 am
C-Flex , no doubt about it.  The circular bore is a dead givaway,  made too many of 'em.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/11/2014 01:02 am
1) The dynamic response of this structure (the EM Drive on the torsional pendulum) is governed by the ratio of the excitation frequency to the natural frequencies of the structure.

2) Mulletron stated that he didn't care about the natural frequency of the pendulum...

3) Mulletron was under the completely wrong understanding that the pendulum at NASA Eagleworks was a hanging pendulum...

4)  blah blah blah...

...what is unknown is the lumped mass (the EM Drive) at a given distance from the center of rotation.

5) Moreover, we don't need to know the mass to compute the dynamic response at all. ... [per] [Rodal], March, Frob, NotSo...

1)  Primitive man get that.  But the governance of these ratios and fequencies is dependent on the relatively massive additions to the torsional pendulum here and there along its structure.

IOW, an empty torsional pendulum will have a natual frequency 'x', and anatural frequency 'y' when loaded with stuff at various points.

2) Mulletron's was an unnecessary hissy fit, true.

3) That's what it seems from reading the back and forth.

4) rimitive man think there be too much certainty in such a dearth of factual experimental information.

Primitive man continue to ask if there is some way to model ranges of behavior.

5)  Which primitive man flat out do not get, and which p.m. look at with very wary eye.  (Vewwy wawwy, per Elmer Fudd)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/11/2014 01:03 am
Hope this mention [of] prosecution will not [cause to be entertained] a certain level of paranoia : fact is, like for any rational investigation activity, hair splitting is also part of the job of science.

Nothing but admiration of your command of my native lingo; still, you seemed to have a few grammatical oddities which I believe I've corrected...

Quote from: Frob
I propose the hypothesis that the microwave amplifier is the cause of the lack of punch of the signal, if the amplifier takes more than .1s to reach full power.

Me think me disagree here somewhat.  Can't be that amp is starting from no current whasoever.  The amp must be operating from a standby mode, where it is ready to give as square a wave as it can as soon as it is triggered. 

Otherwise, there would have to be a warm-up period for the amp, where they would have to shunt the signal elsewhere, till it got up to spec.

But they were sloppy on the frequencies, as earlier noted, so what do me know?
Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 01:20 am
....
Quote from: Rodal
5) Moreover, we don't need to know the mass to compute the dynamic response at all. ... [per] [Rodal], March, Frob, NotSo...

....

5)  Which primitive man flat out do not get, and which p.m. look at with very wary eye.  (Vewwy wawwy, per Elmer Fudd)

I (and several competitors) analyzed and solved field dynamic problems much more complicated than this without having to know the mass or the stiffness of the vibrating machinery.  You go out on the field with vibration sensors (amplitude vs time) and perform a Fourier Transform of the data on the spot: you get power spectral density vs frequency.  Same way as I did here: using FFT to analyze the data.  Happens every day in the field.  Actually many customers have had for years built-in vibration monitoring that automatically outputs Power Spectral density vs frequency.

For problems that involve non-stationary response I use (time-frequency) Wavelet analysis.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/11/2014 01:31 am
This whole "frequency" thing is a distraction from the actual issues raised on page 206, starting here: http://forum.nasaspaceflight.com/index.php?topic=29276.msg1286223#msg1286223

The word "frequency" was never mentioned by anybody until the very bottom of page 206.
Title: Re: EM Drive Developments
Post by: aero on 11/11/2014 06:20 am
@Rodal - Did you write that the side walls of the cone are not subject to heating?

Because if the side walls did warm the outside boundary layer of air then the warmer boundary layer would rise causing a reduced pressure over the outside of the cone walls. The result would be a net force toward the small end.

Actually, I just glanced at the ideal gas law relationship and no easy way to calculate the lift force on the cone walls popped out. Its a constant pressure set-up because pressure is atmospheric, but total pressure includes dynamic pressure of the rising boundary layer. And of course the aerodynamic force is generated by the difference in static pressures caused by dynamic pressures. In this case with very low heating (small temperature change) the dynamic pressure would be very small. But then the cone walls are quite large so a very small pressure difference might create a small measured thrust.

Say 1/4 of the cone on each side contributed to aerodynamic normal force. The total area normal dot axial direction is big end area minus small end area divided by two (2*1/4). That is, about 193 cm2. Since F = P*A, to develop 50 micro N needs 0.00259067 N/m2 or 2.6 milli-Pa.

Dynamic pressure = rho*V2/2 and rho at sea level is about 1.225 kg/m3. It boils down to requiring a rising air velocity greater than  V ~ 6.5 cm/s which is probably to much to be generated quickly enough to avoid a tell-tale time lag in the measured signal.

It was just a thought.

This idea doesn't even consider the Cannae superconducting thruster, to which it could not apply.

Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 11:47 am
@Rodal - Did you write that the side walls of the cone are not subject to heating?

Because if the side walls did warm the outside boundary layer of air then the warmer boundary layer would rise causing a reduced pressure over the outside of the cone walls. The result would be a net force toward the small end.

Actually, I just glanced at the ideal gas law relationship and no easy way to calculate the lift force on the cone walls popped out. Its a constant pressure set-up because pressure is atmospheric, but total pressure includes dynamic pressure of the rising boundary layer. And of course the aerodynamic force is generated by the difference in static pressures caused by dynamic pressures. In this case with very low heating (small temperature change) the dynamic pressure would be very small. But then the cone walls are quite large so a very small pressure difference might create a small measured thrust.

Say 1/4 of the cone on each side contributed to aerodynamic normal force. The total area normal dot axial direction is big end area minus small end area divided by two (2*1/4). That is, about 193 cm2. Since F = P*A, to develop 50 micro N needs 0.00259067 N/m2 or 2.6 milli-Pa.

Dynamic pressure = rho*V2/2 and rho at sea level is about 1.225 kg/m3. It boils down to requiring a rising air velocity greater than  V ~ 6.5 cm/s which is probably to much to be generated quickly enough to avoid a tell-tale time lag in the measured signal.

It was just a thought.

This idea doesn't even consider the Cannae superconducting thruster, to which it could not apply.
For the transverse electric mode TE012 the electric field is circular, perpendicular to the long axis of the truncated cone.  The electric field is zero at the inner copper surface.  The only heating takes place because of the magnetic field in the long axial direction which heats the flat ends of the cone in circular areas centered at the center of the flat areas, as per attached picture.   Therefore there is no heating whatsoever of the round lateral surface of the cone.  Moreover, due to the Polyethylene insulation that Eagleworks placed at the interior small flat end, only the central portion of the big flat end gets all the power heating:

The following actions by NASA Eagleworks further maximized the increase in temperature of the flat ends:
1) They insulated the exterior surfaces of the flat ends of the cone by covering them with PCBoard polymer
2) They insulated the interior surface of the small flat end of the truncated cone by covering it with Polyethylene, which they called a  Quantum Vacuum dielectric.
3) Thus the only heated area under mode TE012 was a smaller central circular interior surface of the big flat end.
4) If the only copper surface at the big end was a 0.002 inch copper layer on the interior of the PCBoard (ref. @notSoSureOfIt) then this very thin copper would have served to significantly increase the temperature at the interior of the big flat end.

The Eagleworks truncated cone instead of pushing against the Quantum Vacuum is an inefficient heater heating a small central portion of the big flat end.  The steep force measured by Eagleworks is the inertial reaction due to this heating, that gets transmitted to the pendulum arm by the two bolts at the bottom of the PCBoard.

Electric field in Red
Magnetic field in Blue
Title: Re: EM Drive Developments
Post by: Mulletron on 11/11/2014 02:02 pm
http://www.youtube.com/watch?v=Wokn7crjBbA

The test campaigns are discussed in the video too.

@39:25 the slide says the conical frustum has a 4" dielectric resonator!?!?!
Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 02:11 pm
http://www.youtube.com/watch?v=Wokn7crjBbA

The test campaigns are discussed in the video too.

@39:25 the slide says the conical frustum has a 4" dielectric resonator!?!?!

NASA Ames Research Director’s Colloquium, August 12, 2014.

discusses Infrared camera image of the Cannae test article at @36 minutes

Of course, as posted previously, there is no heating of the exterior round lateral surface of the cone.
White did not comment on interior heating of the big end or the insulation they placed on the exterior of the flat areas of the cone or the insulation they placed on the interior small end.

Observe that when White discusses the truncated cone TE012 test results he shows the electric field shown below (this seems to contradict the "Anomalous" report that states that this electric field is a calculation for the future truncated cone design ?)

White repeatedly discusses the initial results using TE012 mode without the dielectric they measured no thrust force and he says this is in agreement with this Quantum Vacuum theory.  White does not discuss the fact that the "dielectric" polymer insulates the interior surface small flat end from heating and thus all the heating is then concentrated on the big flat end interior surface.

White states that the test campaign results agrees with the Q-Thruster Quantum Vacuum Plasma White modeling (he does not use the word "plasma" though). Notice that White never addresses the fact that according to his previous publications the Q-Thruster force should be perpendicular to both the electric and magnetic fields, and therefore his predicted thrust force should be perpendicular to the actual measured force.

@52 minutes there are a few "softie" questions for about 8 minutes.  The "toughest" question asked is concerning the requirement for negative mass for the Alcubierre drive and where is this negative mass coming from.  White answers that it comes from the Quantum Vacuum.

Another question he answers is regarding conservation of momentum, he says that his theory predicts conservation of momentum because the Q-thruster is like a submarine using the water to propel itself and that he plans to measure the "Quantum Vacuum wake" by using another EM drive behind it.

He answers that the Alcubierre drive doesn't violate causality and that it cannot be used for time travel to the past because the spacecraft never travels faster than the speed of light in its local spacetime.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/11/2014 03:07 pm
There's no reason thermal effects and quantum effects can't both exist. Electronics get hot. The issue is which one is more?

Key points:
@45:20 dielectric importance in TE012 and ongoing
@54:15 conservation of momentum (saved by the qv bell, pushing off the qv? no way)

What's up with the disparity between the 4" dielectric slug from the slides and the reported 6.25"x1.06" slugs from the paper? Much inconsistency with this one.

Was dielectric important to TM211?

This thing really boils down to the limited understanding of the QV.

@56:00 @ 57:00, smart guy questions, I guess Dr. White is a negative vacuum energy kinda guy, as many are.

Dr. White seems to have realized he should curb his use of the word "plasma." Q-thruster is less likely to anger heavy hitter theoretical physicists, who know there is no such thing as a QV plasma.
Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 03:14 pm

....
What's up with the disparity between the 4" dielectric slug from the slides and the reported 6.25"x1.06" slugs from the paper? Much inconsistency with this one.

...
This inconsistency parallels the inconsistency of showing in his slide for the TE012 truncated cone test the electric field shown below, which in the "Anomalous" report is indicated to be the electric field of a future dielectric design and NOT the  tested design.

So, 4 inches must be diameter of the dielectric shown in this COMSOL Electric Field prediction.

Title: Re: EM Drive Developments
Post by: Mulletron on 11/11/2014 03:42 pm
I'm wondering if someone screwed up while drafting the paper and those 6.25"x1.06" dielectrics are actually what is in Cannae. A tall narrow cylinder.

If the dielectric in the conical frustum is 4" (Tall or wide or both? What is supporting it?), we have our cavity estimates way off.

I'm not willing to bother anyone by emailing them for clarification. Anyone else already have a dialogue going?
Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 05:01 pm
I'm wondering if someone screwed up while drafting the paper and those 6.25"x1.06" dielectrics are actually what is in Cannae. A tall narrow cylinder.

If the dielectric in the conical frustum is 4" (Tall or wide or both? What is supporting it?), we have our cavity estimates way off.

I'm not willing to bother anyone by emailing them for clarification. Anyone else already have a dialogue going?
Equally (or more ?) likely that White conflated the new "dielectric" design and COMSOL FE analysis with the one used for actual testing by Brady and March as White rushed to present the Power Point presentation for the NASA Ames colloquium.

In the report one would have had to have the confluence of:

A) the several authors of the paper missing the dielectric mistake as opposed to just White making the mistake in his Ames presentation.

B) Probably more care would go into the AIAA paper and presentation, besides the multiple authors as opposed to an internal NASA presentation with only 8 minutes of questions

C) for the report there would have had to be several errors: the insert with the 6" dimension instead of 4" and most important the narrative that the COMSOL FE electric field is for a new design not yet tested.  It is unlikely that someone would refer to a future design unnecessarily.  More likely that White made the mistake in putting the Ames presentation together as Brady and March were the ones more involved in actual testing and this detail may not have been as vivid in White's mind compared to Brady and March.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/11/2014 06:14 pm
This just goes to show that given the lack of detailed information, this stuff must be taken with a grain of salt and there is no point wasting steam going down the analytical rabbit hole and throwing numbers at ghosts. Even worse, it could lead us to the wrong conclusions.

The point of yesterday's "hissy fit".

Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 06:25 pm
Don't sermonize to others what they may be able to accomplish based on your own experience.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/11/2014 06:28 pm


The test campaigns are discussed in the video too.

@39:25 the slide says the conical frustum has a 4" dielectric resonator!?!?!

NASA Ames Research Director’s Colloquium, August 12, 2014.

discusses Infrared camera image of the Cannae test article at @36 minutes

Of course, as posted previously, there is no heating of the exterior round lateral surface of the cone.
White did not comment on interior heating of the big end or the insulation they placed on the exterior of the flat areas of the cone or the insulation they placed on the interior small end.

What we see on the IR picture is the Cannae where there is no low thermal conduction PCB plate involved...

And even on this mostly copper apparatus we see not a lot of heat going out, "because it's High Q". But high Q or not, driven at resonance or not, power pumped in frustum should be dissipated from frustum. The RF amplifier heats a lot (comparatively). I don't find again the actual values of power injected for Cannae, nor the value of power injected to amplifier (as DC current of 5.6 A). I get that the RF amplifier has a limited efficiency (how much ?) and delivers less in microwave watts than it takes in DC watts, that would account for such a disparity in dissipated power from RF amplifier relative to frustum ? What when the RF power is less (like 2.6 W) : the amplifier eats less DC ( I remember someone told it was class AB...) or dissipates more (like a class A that takes as much power input, whether outputting AC or not) ?

My doubt : is the microwave power (indicated as reference for all the experiments, like 16.9 W ...) really pumped in the cavity "one way" or isn't a large part of this power bouncing back at the RF amplifier and being dissipated there, making for a lower net power input to cavity ? Opinions from people knowing RF circuits and microwave generators better ?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/11/2014 06:38 pm


The test campaigns are discussed in the video too.

@39:25 the slide says the conical frustum has a 4" dielectric resonator!?!?!

NASA Ames Research Director’s Colloquium, August 12, 2014.

discusses Infrared camera image of the Cannae test article at @36 minutes

Of course, as posted previously, there is no heating of the exterior round lateral surface of the cone.
White did not comment on interior heating of the big end or the insulation they placed on the exterior of the flat areas of the cone or the insulation they placed on the interior small end.

What we see on the IR picture is the Cannae where there is no low thermal conduction PCB plate involved...

And even on this mostly copper apparatus we see not a lot of heat going out, "because it's High Q". But high Q or not, driven at resonance or not, power pumped in frustum should be dissipated from frustum. The RF amplifier heats a lot (comparatively). I don't find again the actual values of power injected for Cannae, nor the value of power injected to amplifier (as DC current of 5.6 A). I get that the RF amplifier has a limited efficiency (how much ?) and delivers less in microwave watts than it takes in DC watts, that would account for such a disparity in dissipated power from RF amplifier relative to frustum ? What when the RF power is less (like 2.6 W) : the amplifier eats less DC ( I remember someone told it was class AB...) or dissipates more (like a class A that takes as much power input, whether outputting AC or not) ?

My doubt : is the microwave power (indicated as reference for all the experiments, like 16.9 W ...) really pumped in the cavity "one way" or isn't a large part of this power bouncing back at the RF amplifier and being dissipated there, making for a lower net power input to cavity ? Opinions from people knowing RF circuits and microwave generators better ?

The point of a well engineered rf system is to keep forward power high and reflected power low. This is evidenced by using a dual port directional coupler with fwd/reflected power sample ports tied to power meters so you can tune your device to keep reflected power from going back into your amp/sig gen/whatever. This is called VSWR and is a ratio. So the rf energy going into the cavity will eventually be absorbed by the cavity as a function of Q and be converted to heat. You would never want your power to be reflected back into your signal generating gear. This stuff is my day job.
Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 07:25 pm


The test campaigns are discussed in the video too.

@39:25 the slide says the conical frustum has a 4" dielectric resonator!?!?!

NASA Ames Research Director’s Colloquium, August 12, 2014.

discusses Infrared camera image of the Cannae test article at @36 minutes

Of course, as posted previously, there is no heating of the exterior round lateral surface of the cone.
White did not comment on interior heating of the big end or the insulation they placed on the exterior of the flat areas of the cone or the insulation they placed on the interior small end.

What we see on the IR picture is the Cannae where there is no low thermal conduction PCB plate involved...

.....

Thank you for emphasizing that.

The COMSOL FE analysis shows the electric field in the dielectric (Teflon PTFE) to be 20 to 50 times higher than elsewhere in the Cannae.

However both PTFE ("Teflon") in the Cannae and PE (polyethylene) in the truncated cone are non-polar, hence no dipole microwave heating can take place unless they contain some water molecules.

PTFE ("Teflon") is also hydrophobic so not likely to contain water molecules and hence very unlikely to be microwave heated.

Both PTFE ("Teflon") in the Cannae and PE (polyethylene) in the truncated cone are also dielectric-heat-transparent to RF frequencies so negligible dielectric heating in them as well.

So if there is any internal heating in the Cannae it must be the result of the electromagnetic field on the copper.  Unfortunately the magnetic field is not shown.  So no further comments on this unless we analyze the magnetic field in the Cannae, to see whether the dielectric polymer plug is in the way of a magnetic axial field. 

There are questions as to what is the use of the "pillbox" in the Cannae design as brought up by Mulletron and by White.
Title: Re: EM Drive Developments
Post by: birchoff on 11/11/2014 07:32 pm


The test campaigns are discussed in the video too.

@39:25 the slide says the conical frustum has a 4" dielectric resonator!?!?!

NASA Ames Research Director’s Colloquium, August 12, 2014.

discusses Infrared camera image of the Cannae test article at @36 minutes

Of course, as posted previously, there is no heating of the exterior round lateral surface of the cone.
White did not comment on interior heating of the big end or the insulation they placed on the exterior of the flat areas of the cone or the insulation they placed on the interior small end.

What we see on the IR picture is the Cannae where there is no low thermal conduction PCB plate involved...

.....

Thank you for emphasizing that.

The COMSOL FE analysis shows the electric field in the dielectric (Teflon PTFE) to be 20 to 50 times higher than elsewhere in the Cannae.

However both PTFE ("Teflon") in the Cannae and PE (polyethylene) in the truncated cone are non-polar, hence no dipole microwave heating can take place unless they contain some water molecules.

PTFE ("Teflon") is also hydrophobic so not likely to contain water molecules and hence very unlikely to be microwave heated.

Both PTFE ("Teflon") in the Cannae and PE (polyethylene) in the truncated cone are also transparent to RF frequencies so negligible dielectric heating in them as well.

So if there is any internal heating in the Cannae it must be the result of the electromagnetic field on the copper.  Unfortunately the magnetic field is not shown.  So no further comments on this unless we analyze the magnetic field in the Cannae.

If I understand what you said. and the IR camera image from the presentation is not faked. Wouldn't that put a nail in the coffin of thermal effects artifact? At least as far as the Cannae testing is concerned.
Title: Re: EM Drive Developments
Post by: birchoff on 11/11/2014 07:37 pm

The test campaigns are discussed in the video too.

@39:25 the slide says the conical frustum has a 4" dielectric resonator!?!?!

I think the most interesting thing in this entire presentation for me was the elaboration of the next steps. Assuming they wait until after all of the Eagleworks portion of the next steps is done to publish another paper. I suspect there should be more than enough information at that point to know if this is a real effect or not. Especially if they are actually able to run a Null configuration of their thruster in vaccum.

Secondarily, prior to the Q-Thruster testing summary. It looks like White is pushing on with his Warp drive experiments. Wish him the best of luck. Though I am most skeptical as it seems like if the Q-Thruster stuff is shown to not be a real effect but something classical, like Heat or Magnetic coupling. Then he would have no way to justify that any artifacts observed by his interferometer was caused by space warping.
Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 07:40 pm


The test campaigns are discussed in the video too.

@39:25 the slide says the conical frustum has a 4" dielectric resonator!?!?!

NASA Ames Research Director’s Colloquium, August 12, 2014.

discusses Infrared camera image of the Cannae test article at @36 minutes

Of course, as posted previously, there is no heating of the exterior round lateral surface of the cone.
White did not comment on interior heating of the big end or the insulation they placed on the exterior of the flat areas of the cone or the insulation they placed on the interior small end.

What we see on the IR picture is the Cannae where there is no low thermal conduction PCB plate involved...

.....

Thank you for emphasizing that.

The COMSOL FE analysis shows the electric field in the dielectric (Teflon PTFE) to be 20 to 50 times higher than elsewhere in the Cannae.

However both PTFE ("Teflon") in the Cannae and PE (polyethylene) in the truncated cone are non-polar, hence no dipole microwave heating can take place unless they contain some water molecules.

PTFE ("Teflon") is also hydrophobic so not likely to contain water molecules and hence very unlikely to be microwave heated.

Both PTFE ("Teflon") in the Cannae and PE (polyethylene) in the truncated cone are also transparent to RF frequencies so negligible dielectric heating in them as well.

So if there is any internal heating in the Cannae it must be the result of the electromagnetic field on the copper.  Unfortunately the magnetic field is not shown.  So no further comments on this unless we analyze the magnetic field in the Cannae.

If I understand what you said. and the IR camera image from the presentation is not faked. Wouldn't that put a nail in the coffin of thermal effects artifact? At least as far as the Cannae testing is concerned.

Well, I had said no further comments on this, but since you ask ... :)

I think (but I would need to analyze this to be sure) that there is an axial magnetic field through the axis of the Cannae, while the electric field is rotationally transverse, as in the TE012 mode of a cylinder.  If this is the case, the dielectric polymer could be blocking the magnetic field heating of the copper in the long end of the Cannae.  (Unfortunately White did not provide the magnetic field for the Cannae and he did not provide the dimensions of the Teflon plug or the internal dimensions of the Cannae long section and how the dielectric fits inside it (how snug is it?)

No nail in the coffin but certainly the Cannae would require much more analysis to show it as a thermal artifact as compared to the truncated cone where I have preliminary numbers showing the initial impulse to be due to internal heating of the copper at the big diameter flat end.
Title: Re: EM Drive Developments
Post by: aceshigh on 11/11/2014 09:04 pm
He answers that the Alcubierre drive doesn't violate causality and that it cannot be used for time travel to the past because the spacecraft never travels faster than the speed of light in its local spacetime.

I remember an astrophysicist friend of mine and other people at physics forums saying that no matter if the local spacetime didn't change (warp) or you got instantaneously from one point to another (warp), it was still time travel to the past, because of the light cone or something like that. Any opinion Dr Rodal?
Title: Re: EM Drive Developments
Post by: frobnicat on 11/11/2014 09:14 pm
.../...
Both PTFE ("Teflon") in the Cannae and PE (polyethylene) in the truncated cone are also transparent to RF frequencies so negligible dielectric heating in them as well.

So if there is any internal heating in the Cannae it must be the result of the electromagnetic field on the copper.  Unfortunately the magnetic field is not shown.  So no further comments on this unless we analyze the magnetic field in the Cannae.

If I understand what you said. and the IR camera image from the presentation is not faked. Wouldn't that put a nail in the coffin of thermal effects artifact? At least as far as the Cannae testing is concerned.

Obviously it would be difficult to definitely prove thermal effects artefacts as the main contributor to the reported thrust, at a distance from the experiment and given the sparse published information. What I'm confident we can do (on spare time...) even at amateur level (serious amateur level) is bring forward possible thermal modes of "failure", maybe in qualitative agreement (parameters dependencies the right way) and roughly quantitative agreement with what is published : if such is the case, that would not prove definitely the results as being thermal in origin but would require experimenters (or preferably third parties) to see in-situ that it is not thermal as hypothesized by the amateurs...

The authors have been fast at dismissing the possible thermal effects and to answer remarks on the subject. The IR picture is showing that they are thinking about it and making real effort on this (as I guess that is one of the most common doubt raised on their experimental results, beyond theoretical scepticism) but the impression is that they give too much credit to the steepness of their step response so that "it surely can't be thermal, or not all thermal" as common sense would tell "because thermal would be too slow for such a step response".

For instance (that's my working hypothesis at the moment), air has a very low thermal capacity but can give high forces with very modest heat energies basically through pV = nRT. Air temperature don't really show up in the IR picture. A one °C in a closed cavity will give 10s of pascals differential pressure buildup, 10N/m² that's more than .1N differential between small end and big end and we are measuring 10s of µN so this is 4 orders of magnitude less. Granted : if the cavity is perfectly hermetic this pressure buildup can't really make any net thrust. But the slightest leak, especially the slightest leak, will jet this modest overpressure enough to make the relevant µN magnitude.

If there are big holes, like vents in a microwave oven, no pressure buildup, no efficient jet. If there are no holes at all, no jet. That would need a clarification from the experimenters : are the cavity perfectly hermetic or not. And if they are not, what is the path the air is taking to equilibrate to ambient. The fact that removing a dielectric plug in the Cannae makes thrust plummet would be in agreement with that : the leak path would become too big to make an efficient nozzle.

If humidity of air is enough to couple with high energy density standing waves (high Q...) there is instantaneously a constant rate of dT/dt, and it don't take much time for a pressure buildup and reaching a plateau of thrust from a "warm" air jet escaping the cavity. Hence a steplike response. But I'm stuck with this question of the volumetric heating of ordinary lab air (30% to 70% relative I guess) by "high Q microwaves" (by that I mean that even a high transparency material relative to microwaves still has a chance to couple with some amount of power). This would probably be a very simple question to answer for some specialist.

So for instance, there is no nail in the coffin of this idea before the questions of air leaks and volumetric air heating are settled.
Title: Re: EM Drive Developments
Post by: Rodal on 11/11/2014 09:34 pm
He answers that the Alcubierre drive doesn't violate causality and that it cannot be used for time travel to the past because the spacecraft never travels faster than the speed of light in its local spacetime.

I remember an astrophysicist friend of mine and other people at physics forums saying that no matter if the local spacetime didn't change (warp) or you got instantaneously from one point to another (warp), it was still time travel to the past, because of the light cone or something like that. Any opinion Dr Rodal?
I agree with the astrophysicist friend of yours that if the Alcubierre superluminal warp vehicle would be possible it could also act as a time machine because it distorts the spacetime around the spacecraft, and therefore time-loops are possible (regardless of the actual internal local speed of the spacecraft)  but I'm not interested in engaging into a long multi-post argument with anybody that agrees with Dr. White, as I don't think this thread is the proper place to have such time-travel arguments.

I have seen this stuff debated by others.  What most physicists (including Alcubierre himself) agree with (except apparently Dr. White and a few others including a Portuguese scientist),  is that the Alcubierre drive is not practically feasible and that wormholes remain as the only way to possibly ever travel superluminally.  I haven't watched the movie "Interstellar" yet  :)

https://www.youtube.com/watch?v=zSWdZVtXT7E

https://www.youtube.com/watch?v=LY19rHKAaAg
Title: Re: EM Drive Developments
Post by: aceshigh on 11/11/2014 09:46 pm
João Magueiro?
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/11/2014 11:52 pm
Quote
I have seen this stuff debated by others.  What most physicists (including Alcubierre himself) agree with (except apparently Dr. White and a few others including a Portuguese scientist),  is that the Alcubierre drive is not practically feasible and that wormholes remain as the only way to possibly ever travel superluminally.  I haven't watched the movie "Interstellar" yet  :)

Doctor McCulloch (MiHsC) claims his theory offers a super-luminal possibility, though the details are beyond me (as is much else).

As to 'Interstellar': overly long, badly flawed in places (you WILL want to launch the organ into space) but it did pay a fair bit of attention to the science, including some of the stranger effects possible with worm holes, time dilation, and what might as well be...hmmm...best leave that out. 
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/12/2014 02:03 pm
Fun to play around with:
http://amrita.vlab.co.in/?sub=1&brch=280&sim=1518&cnt=4

Nothing is suspended from a wire:

Quote from: Brady, March, White, et.al.
The pendulum arm pivots about two linear flexure bearings in a plane normal to gravitational acceleration. The flexure bearings provide an essentially-frictionless and hysteresis-free interface between the static test stand fixed structure and the dynamic pendulum arm. Test article force is measured by measuring the pendulum arm displacement and calculating the force via the flexure bearing spring constants that were determined during test facility setup

NASA Eagleworks has an inverted pendulum.

According to Paul March, NASA Eagleworks uses as a torsional spring two Riverhawk C-flex bearing blocks with torsional spring constant
(http://www.onesworks.com/wp-content/uploads/2011/02/SingleDouble.jpg)

(http://flexpivots.com/cantilevered-single-ended-pivot-bearings/) centered 2.38" above and below the centerline of the 24.00" long by 1.50" Faztek aluminum pendulum arm. The long end of the pendulum arm is 15.5" from the torque pendulum's center of rotation, which makes the other short-end of the pendulum arm 8.5" from the center of rotation. 

However, the NASA report shows a linear flexure bearing  http://flexpivots.com/linear-flexure-bearing/

Well, the pic shows the bearing block anyway, not necc the c-flecs  (always used c-flex me self back then)

So, who are we to believe you think based on your experience and looking at the picture?  (Honest question, not a trick question)

The report that states linear bearing (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=620106;image)or Paul March that stated C-Flex bearing?
It is indeed a C-Flex torsion balance.  I think calling it "inverted" is causing more trouble than it's solving.  This is the design used by Woodward, who was the first to put the liquid metal contacts in, and adopted by him in 2005 from the Austrian Research Center who has been running one for more than a decade.  It was in light of this Woodward named his balance the "ARC Lite" but it turns out, ARC did not invent the balance either.  It was in service at UCLA before this and several other places, and is certainly the most precise balance design to date.  Suspension balances suffer different issues, so it is a toss up which is better, but the torsion balance is certainly more accurate as it has nN resolution and can carry a great deal of mass and retain that resolution.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/12/2014 02:10 pm
@Rodal - Did you write that the side walls of the cone are not subject to heating?

Because if the side walls did warm the outside boundary layer of air then the warmer boundary layer would rise causing a reduced pressure over the outside of the cone walls. The result would be a net force toward the small end.
The balance design unfortunately does suffer some small amount of vertical to horizontal coupling as changes in vertical force can show up as small horizontal thrusts.  This is one reason why Woodward's balance (and one supposes the one at Eagleworks) includes the ability to physically reorient the thruster to point left and right, so that sort of coupling can be subtracted out as common noise.  Precise explanations of this out ought to appear in any peer review lit that eventually comes from Eagle.
Title: Re: EM Drive Developments
Post by: Rodal on 11/12/2014 02:50 pm
@Rodal - Did you write that the side walls of the cone are not subject to heating?

Because if the side walls did warm the outside boundary layer of air then the warmer boundary layer would rise causing a reduced pressure over the outside of the cone walls. The result would be a net force toward the small end.
The balance design unfortunately does suffer some small amount of vertical to horizontal coupling as changes in vertical force can show up as small horizontal thrusts.  This is one reason why Woodward's balance (and one supposes the one at Eagleworks) includes the ability to physically reorient the thruster to point left and right, so that sort of coupling can be subtracted out as common noise.  Precise explanations of this out ought to appear in any peer review lit that eventually comes from Eagle.

Rather than arguing about what something should be called (whether this balance should be called inverted or something else -it is an undeniable fact that it has a stiff flexural vertical components-) scientists proceed with analytical models of the testing equipment they use.  This is the case at CERN, and it is the case for Physics and Engineering thesis at MIT: all experimental work should be accompanied by analytical models of the testing equipment. 

With Mathematica I have modeled the full system of coupled nonlinear differential equations for the Eagleworks balance.  I am not aware of Eagleworks having conducted similar analytical models (coupled nonlinear differential equations) of their testing equipment. 

The reason why I modeled the full system of coupled differential equations for their testing equipment was both that I had the ability to do so (from my prior professional experience) and also because of my professional curiosity.  There are quite a number of studies at MIT on testing equipment and balances of different types to study electric propulsion and other forms of propulsion.  It is known that due to the thrusters exhibiting a wide frequency spectrum, that parasitic, Duffing, Hill equation, and many other forms of nonlinear vibration can take place due to self-excitation, coupling, and nonlinearities in general.  Without an analytical model one cannot dismiss outright these effects from taking place. 

So, I modeled the testing equipment in case the thruster would exhibit high frequency components.  What do I see from running the model? The same thing I (and Frobnicat among others) see from looking at the response: it is behaving as a simple horizontal torsional pendulum.  There are no high frequency components, no nonlinearities. No self excitation.  So, for the exhibited response of this thruster so far at Eagleworks, I have no problem in calling this a simple horizontal torsional pendulum.   The lack of excitation of higher frequencies, is not just a characteristic of the testing equipment, it is also a characteristic of the tested thruster.  This is what's important here, something that frobnicat with his experience in dynamics has also noticed: this thruster is not exhibiting a complex high-frequency response.  The pendulum arm (only 1.5 inch by 1.5 inch aluminum Faztek, which is not rigid by any consideration) frequency is not being excited.  No higher mode excitation.   

It does behave as a microwave heater attached to a horizontal torsional pendulum:

The Fourier Transform analysis I conducted shows practically nothing with period less than 2 seconds.  Nothing.  Nada.

The autocorrelation analysis I posted shows a boring simple harmonic response.  No random excitation. None.  Nada.

The amplitude response vs. time does not indicate it either.

This shows me that there is nothing anomalous about the response of the truncated cone: it is most probably due to thermal effects.   Even a chemical thruster exhibits complex response.  This is not the case here.  As frobnicat pointed out there is a huge amount of effort in trying to see the effects of the Quantum Vacuum and not enough effort to try to see the effect of classical physics.
Title: Re: EM Drive Developments
Post by: D_Dom on 11/12/2014 03:18 pm
This shows me that there is nothing anomalous about the response of the truncated cone: it is most probably due to thermal effects.   Even a chemical thruster exhibits complex response.  This is not the case here.

Thanks for your efforts investigating this experiment. As I understand what you are saying (which is not much ) thermal effects create none of the complex response normally found in a chemical or electric thruster.

Page after page of this discussion have me convinced that I will take some time, visit the links, work some equations and generate an understanding of the topic. Thanks for explanations that seem within reach though I am not yet able to grasp.

Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/12/2014 03:57 pm
. . .all experimental work should be accompanied by analytical models of the testing equipment.

. . .As frobnicat pointed out there is a huge amount of effort in trying to see the effects of the Quantum Vacuum and not enough effort to try to see the effect of classical physics.

It took the guys at Eagle a couple years to characterize the new balance. Normally it takes about a year but they had trouble with coupling to the stainless tank, which is common for this kind of setup.  George Hathaway documents this kind of struggle somewhere on the web and it took his lab up in Canada more than a year to solve the coupling issue.  Woodward took far less time because he uses acrylic so there's less opportunity for high voltage to couple.  Personally I think the best compromise is polycarbonate like Lexan since it has a lower vapor pressure than acrylic so one can pull harder vacuum.  I think Woodward can only pull E-3T and Lexan can provide E-5T.  I would just note to those who always want to see E-12T, that if you don't see a source scale at ambient to E-3T, you know you don't have things like thermal and ionic wind, so it is a poor trade to spend an extra $100k to the vacuum system, and an extra year characterizing the setup, just to have harder vacuum.  IMHO, leave the hard vacuum for those doing validation studies who already have such things available.  Clear is also nice in that your thermal sensing and doppler vibrometer can have easy access without going inside the chamber.

I think you're again mistaking your resource.  I will remind you again, you are analyzing a CONFERENCE PAPER.  It is not normal to put the kinds of detail into a conference paper that you are complaining are missing.  You are doing analysis that is quite impressive, but you are working without the real details because you are working from a conference paper. 

IMHO, if Eagle can get other NASA centers to investigate this without publishing in peer review, this is likely what they will do.  Sonny has always shied away from careful inspection of his work.  I see no reason for him to publish in peer review when he can get 3 other NASA centers to go after validation without risking anything.  He's very shrewd that way.
Title: Re: EM Drive Developments
Post by: Rodal on 11/12/2014 04:10 pm
....I see no reason for him to publish in peer review when he can get 3 other NASA centers to go after validation without risking anything.  He's very shrewd that way.

When you write " to go after validation without risking anything.  He's very shrewd that way" I don't understand what is not being risked and why is this being "shrewd".

A scientist wants as much peer review as he can get.  You want to publish in peer review journals.  It  is to your own benefit. If you are correct you get the recognition.  If you are incorrect the sooner you find out the better.  If others point out that you are missing something it is to your benefit. If one doesn't get peer review and discussion with other scientists, then one really may end up wasting precious years of your life in the wrong path and not really learn anything.

Quote from:  Benjamin Franklin
Lost time is never found again.


Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/12/2014 05:23 pm
When you write " to go after validation without risking anything.  He's very shrewd that way" I don't understand what is not being risked and why is this being "shrewd".

A scientist wants as much peer review as he can get.  You want to publish in peer review journals.  It  is to your own benefit. If you are correct you get the recognition.  If you are incorrect the sooner you find out the better.  If others point out that you are missing something it is to your benefit. If one doesn't get peer review and discussion with other scientists, then one really may end up wasting precious years of your life in the wrong path and not really learn anything.

In my experience, Sonny has always taken the path of least resistance.  I don't know if he's ever published in peer review and in fact, doing so is problematic since ZPF and QVF are not well liked in the journals.  When Sonny went to do his doctoral thesis, he was denied use of his QVF model since it is not the stuff physicists want to waste time with.

I do however agree with your point.  I'm just answering your question.

What you might do if you want more detail on the balance, is contact Dr. Duncan Cummins (PhD Oxford? or Cambridge?--I often confuse them), who runs the little Stardrive group that did some analysis on the Eagle balance when it was being characterized.  Duncan is a skeptic who thinks this stuff is all naive, but he runs the little yahoo group that looks into these things.  IIUC, Paul March and Sonny are both a part of that group, as is Andrew Palfreyman (also Oxford, unless I'm confusing it with Cambridge again) and David Mathes of CalTech.  It was Duncan who said to me back in May or so that Eagle had had lots of signal until they grounded the balance properly and then it all went away.  Don't think that's really true but you could ask him.  He'd probably be thrilled to have someone with your skills and experience commenting in his group.

[email protected]

And about the shrewdness thing. . .it is good to note that without publishing in peer review and putting out all the work this entails, Sonny has managed not only to redirect substantial NASA resources and DARPA funding onto his project, but now several NASA centers will be pursuing it.  That is at the least, highly efficient, and he still hasn't stuck his neck out for his QVF model.  That's more than shrewd.  It's clever even.  I'm not suggesting this is how science should be done, but he is getting what he wants.  The trouble is, that eventually everyone will figure out the truth of the issue and the consequences of that will be interesting to say the least.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/12/2014 06:07 pm
Here's a pic on the web of Woodward's torsion balance, the "ARC Lite".  The thruster is in a squarish Faraday cage on the right.  This is out of the chamber for some sort of work, so things like the cable draped over on the left are out of place.  Note the coaxial liquid metal contacts centered over the torsion bearing at center, the aluminum damper at left, and at lower right the open coils used to calibrate the balance.  I expect this is how the Eagle balance works as well.  You just can't see much of it from the Eagle pics.

http://nextbigfuture.com/2011/06/james-woodward-reports-consistent-and.html

Would that we could see some of this same level of investigation of Woodward's data.  Personally I am more impressed with the analysis here in this thread than that at NASA, even by folks like Creon Levit.  If Dr. Rodel, you want to offer your services to do analysis for Levit, let me know and I'll send a private link.

can you tell me, where I would find more folks able to do the level of analysis you've been doing in this thread--someone to lead an exploration into M-E physics?
Title: Re: EM Drive Developments
Post by: birchoff on 11/12/2014 08:48 pm
...

And about the shrewdness thing. . .it is good to note that without publishing in peer review and putting out all the work this entails, Sonny has managed not only to redirect substantial NASA resources and DARPA funding onto his project, but now several NASA centers will be pursuing it.  That is at the least, highly efficient, and he still hasn't stuck his neck out for his QVF model.  That's more than shrewd.  It's clever even.  I'm not suggesting this is how science should be done, but he is getting what he wants.  The trouble is, that eventually everyone will figure out the truth of the issue and the consequences of that will be interesting to say the least.

So maybe I am missing something, but if I take what your saying here at face value. The conclusion I am forced to draw is the scrutiny the NASA labs will do of White's QVF model will be significantly less than if he had attempted to get it into a peer review journal. Am I the only one that finds this to be a weird conclusion. Shouldn't labs be doing an equivalent level of review of another teams work before taking on the job of doing validation. At the very least I would hope that the validation is at least required to do more than simply taking the assembled equipment from EagleWorks and running it in a different geographical location.
Title: Re: EM Drive Developments
Post by: Rodal on 11/12/2014 09:33 pm
I received another very interesting e-mail from Bob Ludwick, that I reproduce below:




From: Robert Ludwick
Sent: Wednesday, November 12, 2014 1:54 PM
To: Dr. J. Rodal
Subject: Testing the EmDrive

Hello Dr. Rodal

Although thrust without throwing something out the back is at least improbable (I am of course rooting for the improbable.), I think that the testing problem (to rule out heat artifacts) could be resolved by the test plan I proposed awhile back. 



i. e. 

A.  Establish the resonant frequency (s) and bandwidths of the thruster.

B.  Select a test frequency range that is at least double the bandwidth of the thruster, so that the start and stop frequencies are well outside the high Q region of the thruster.

C.  Select frequency steps so that you are guaranteed AT LEAST ten steps in the high Q region of the thruster.

D.  Set the test frequency to the start frequency, turn on the power amplifier, and wait 5 minutes or so for any thermal and current/magnetic field effects to stabilize.  Measure the residual thermal/magnetic/whatever ‘thrust’.

E.  Start the frequency sweep, with dwell times on each frequency long enough for the mechanical system to settle. Change NOTHING other than frequency.

F.  For each frequency step, record forward and reflected power from the thruster.

G.  After allowing for mechanical settling time, record the thrust.

H.  Go to the next frequency and repeat. 




If there is any ‘anomalous’ thrust related to thruster Q this procedure will detect it.  If the ‘thrust’ is due to thermal effects, it should remain constant throughout the test, as the power/current will be constant throughout the test

It DOES require a highly stable, computer controlled signal source rather than a VCO with a knob, but those, including those suitable for testing superconducting cavities, are available from any equipment rental place (such as ElectroRent) if the lab is too cheap to buy one.  Power meters, too.

I am completely baffled at the apparent disinterest of people and organizations who should be foaming at the mouth at the prospect of getting their hands on a relatively simple device that can convert microwave power into translational motion at efficiencies orders of magnitude better than simple photon rockets.  Apparently they have decided that it is prima facie impossible and therefore don’t want to waste any time or money in finding the problems in some fringe PhD’s test setup.

On the other hand, if I were controlling the budget for spaceships in any form and was aware that at least three disparate groups had detected thrust from EmDrive-like devices, I would want to confirm or refute this thing ASAP.  I’d have lab crews—more than one, at different labs, using different equipment--working overtime until I knew, one way or another, whether it was real or not.  And I would insist in more than one ‘fail’ before I called a halt.  Frankly, doing so should be cheap AND fast.  And the stakes are enormous.

Bob Ludwick
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/12/2014 10:18 pm
The conclusion I am forced to draw is the scrutiny the NASA labs will do of White's QVF model will be significantly less than if he had attempted to get it into a peer review journal. Am I the only one that finds this to be a weird conclusion.
I'm not saying that at all.  I'm a firm believer in the scientific process and one can't project one's desires onto someone else's methods, data and conclusions.  I think the whole QVF model is going to crash and burn.  That's what is interesting. . .the fact this stuff cannot forever be done covertly.  The facts will come out before there are larger funds released, but for the time being it seems several other centers have taken an interest, all because of this conference paper.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/12/2014 10:24 pm
I received another very interesting e-mail from Bob Ludwick, that I reproduce below:




From: Robert Ludwick
Sent: Wednesday, November 12, 2014 1:54 PM
To: Dr. J. Rodal
Subject: Testing the EmDrive

Hello Dr. Rodal

Although thrust without throwing something out the back is at least improbable (I am of course rooting for the improbable.), I think that the testing problem (to rule out heat artifacts) could be resolved by the test plan I proposed awhile back. 



i. e. 

A.  Establish the resonant frequency (s) and bandwidths of the thruster.

B.  Select a test frequency range that is at least double the bandwidth of the thruster, so that the start and stop frequencies are well outside the high Q region of the thruster.

C.  Select frequency steps so that you are guaranteed AT LEAST ten steps in the high Q region of the thruster.

D.  Set the test frequency to the start frequency, turn on the power amplifier, and wait 5 minutes or so for any thermal and current/magnetic field effects to stabilize.  Measure the residual thermal/magnetic/whatever ‘thrust’.

E.  Start the frequency sweep, with dwell times on each frequency long enough for the mechanical system to settle. Change NOTHING other than frequency.

F.  For each frequency step, record forward and reflected power from the thruster.

G.  After allowing for mechanical settling time, record the thrust.

H.  Go to the next frequency and repeat. 




If there is any ‘anomalous’ thrust related to thruster Q this procedure will detect it.  If the ‘thrust’ is due to thermal effects, it should remain constant throughout the test, as the power/current will be constant throughout the test

It DOES require a highly stable, computer controlled signal source rather than a VCO with a knob, but those, including those suitable for testing superconducting cavities, are available from any equipment rental place (such as ElectroRent) if the lab is too cheap to buy one.  Power meters, too.

I am completely baffled at the apparent disinterest of people and organizations who should be foaming at the mouth at the prospect of getting their hands on a relatively simple device that can convert microwave power into translational motion at efficiencies orders of magnitude better than simple photon rockets.  Apparently they have decided that it is prima facie impossible and therefore don’t want to waste any time or money in finding the problems in some fringe PhD’s test setup.

On the other hand, if I were controlling the budget for spaceships in any form and was aware that at least three disparate groups had detected thrust from EmDrive-like devices, I would want to confirm or refute this thing ASAP.  I’d have lab crews—more than one, at different labs, using different equipment--working overtime until I knew, one way or another, whether it was real or not.  And I would insist in more than one ‘fail’ before I called a halt.  Frankly, doing so should be cheap AND fast.  And the stakes are enormous.

Bob Ludwick
I completely agree with this except I would note that there is very serious challenge in the notion of changing frequency and NOTHING else.  Dr. Ludwick points this out, and I agree with him though I'm not sure how one would do what he suggests.
Title: Re: EM Drive Developments
Post by: tchernik on 11/12/2014 10:29 pm
And about the shrewdness thing. . .it is good to note that without publishing in peer review and putting out all the work this entails, Sonny has managed not only to redirect substantial NASA resources and DARPA funding onto his project, but now several NASA centers will be pursuing it.  That is at the least, highly efficient, and he still hasn't stuck his neck out for his QVF model.  That's more than shrewd.  It's clever even.  I'm not suggesting this is how science should be done, but he is getting what he wants.  The trouble is, that eventually everyone will figure out the truth of the issue and the consequences of that will be interesting to say the least.

It's clear for me this would be shot down at any peer-reviewed journal worth a dime, due to its obvious conservation of momentum/energy issues.

And it seems H. White has chosen precisely not to engage in this kind of controversy, and go straight to the replications. If these replications show there's actually something, then he may be in measure to engage with the critics in a more even field.

If he didn't do it like that, he would very likely find himself recanted, possibly fired and without funding.

I agree this is a risky, maybe unethical move, but if he's right, it may be the only way to get some more replication credibility for the phenomenon.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/12/2014 10:51 pm
Been quite busy lately, here is the completion of scraping data from fig. 19 page 15 of "anomalous thrust" by Brady et al. Sorry to release drop by drop, this doesn't take that long to fit a linear piecewise curve to a picture and run through small program to align axis and depersp. and sample at .1s but this is not that fun either... Hope it proves useful.
files : result1.txt result2.txt result3.txt respectively top middle and bottom, 1 sample per .1s
result1 and result2 unchanged from previous release.
result3 adds only 132s of data (because of drift exiting the window) with one calibration pulse and one thrust pulse.

The vertical magnitude is probably a little bit overestimated in my values, I'm putting 30µN at 1µm deviation as vertical scaling.
Not detrended (absolute mean value arbitrary)
Usual caveats : this is a manual reconstruction from badly compressed pictures...
The bottom curve of fig. 19 is especially thick at places, and this is going worse on figure 20, wonder if I should rather make an envelope with two curves (max and min). What could we do with such envelope apart from averaging ? Is there interesting, usable info in the evolution of, ahem, "noise thickness" from place to place ?
Title: Re: EM Drive Developments
Post by: birchoff on 11/13/2014 12:51 am
The conclusion I am forced to draw is the scrutiny the NASA labs will do of White's QVF model will be significantly less than if he had attempted to get it into a peer review journal. Am I the only one that finds this to be a weird conclusion.
I'm not saying that at all.  I'm a firm believer in the scientific process and one can't project one's desires onto someone else's methods, data and conclusions.  I think the whole QVF model is going to crash and burn.  That's what is interesting. . .the fact this stuff cannot forever be done covertly.  The facts will come out before there are larger funds released, but for the time being it seems several other centers have taken an interest, all because of this conference paper.

In that case I would agree with frobnicat. That this is the best way to proceed as far as this research is concerned. Theory is one thing but a real measurable effect that can be demonstrated by an experiment, trumps all. So as long as the other agencies seriously, then it paves the way for a submission to a peer reviewed journal. Though I would argue he would still need to reconcile the proposed theory with known observations. Though I would think he should be able to publish the results and protocol only in a peer reviewed journal (AKA a more rigorous version of the conference paper). Then follow that up with a pure theory paper.
Title: Re: EM Drive Developments
Post by: birchoff on 11/13/2014 12:54 am
I received another very interesting e-mail from Bob Ludwick, that I reproduce below:




From: Robert Ludwick
Sent: Wednesday, November 12, 2014 1:54 PM
To: Dr. J. Rodal
Subject: Testing the EmDrive

Hello Dr. Rodal

Although thrust without throwing something out the back is at least improbable (I am of course rooting for the improbable.), I think that the testing problem (to rule out heat artifacts) could be resolved by the test plan I proposed awhile back. 



i. e. 

A.  Establish the resonant frequency (s) and bandwidths of the thruster.

B.  Select a test frequency range that is at least double the bandwidth of the thruster, so that the start and stop frequencies are well outside the high Q region of the thruster.

C.  Select frequency steps so that you are guaranteed AT LEAST ten steps in the high Q region of the thruster.

D.  Set the test frequency to the start frequency, turn on the power amplifier, and wait 5 minutes or so for any thermal and current/magnetic field effects to stabilize.  Measure the residual thermal/magnetic/whatever ‘thrust’.

E.  Start the frequency sweep, with dwell times on each frequency long enough for the mechanical system to settle. Change NOTHING other than frequency.

F.  For each frequency step, record forward and reflected power from the thruster.

G.  After allowing for mechanical settling time, record the thrust.

H.  Go to the next frequency and repeat. 




If there is any ‘anomalous’ thrust related to thruster Q this procedure will detect it.  If the ‘thrust’ is due to thermal effects, it should remain constant throughout the test, as the power/current will be constant throughout the test

It DOES require a highly stable, computer controlled signal source rather than a VCO with a knob, but those, including those suitable for testing superconducting cavities, are available from any equipment rental place (such as ElectroRent) if the lab is too cheap to buy one.  Power meters, too.

I am completely baffled at the apparent disinterest of people and organizations who should be foaming at the mouth at the prospect of getting their hands on a relatively simple device that can convert microwave power into translational motion at efficiencies orders of magnitude better than simple photon rockets.  Apparently they have decided that it is prima facie impossible and therefore don’t want to waste any time or money in finding the problems in some fringe PhD’s test setup.

On the other hand, if I were controlling the budget for spaceships in any form and was aware that at least three disparate groups had detected thrust from EmDrive-like devices, I would want to confirm or refute this thing ASAP.  I’d have lab crews—more than one, at different labs, using different equipment--working overtime until I knew, one way or another, whether it was real or not.  And I would insist in more than one ‘fail’ before I called a halt.  Frankly, doing so should be cheap AND fast.  And the stakes are enormous.

Bob Ludwick

I think Dr. Ludwick elegantly expresses my frustration with the critics who simply say its impossible give some basic justification for their action and move on. The upside of this thing is way too good to dismiss that way. It deserves serious rigorous consideration. Even if you believe it is not something exotic. Mainly because until it gets that kind of focus it will just keep coming back over and over again, wasting everyones time.
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/13/2014 02:17 am
Quote
....I see no reason for him to publish in peer review when he can get 3 other NASA centers to go after validation without risking anything.  He's very shrewd that way.

Sorry, but I have to take issue with this.

Yes, getting other people to replicate Eagleworks results is great.

However: you do that by releasing exact dimensions, components, and frequencies, along with an equation saying 'this is what we expect' to compare to the actual results.    All of that was missing here.  There must be fifty plus pages in this thread dedicated just to getting precise dimensions - an issue that could have been resolved had that info been in the original paper.

Its almost like Doctor White doesn't want anybody to duplicate his efforts, which sort of negates the point of having three other NASA centers go after validation - how are they supposed to check his results if they cannot adequately replicate the device?

And John?  That organ in 'Interstellar'?  Think more along the lines of the ones found in movies featuring haunted castles, only far louder.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/13/2014 01:48 pm
Me not know what organ still.  Just call me Abby Normal.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/13/2014 02:04 pm
Its almost like Doctor White doesn't want anybody to duplicate his efforts, which sort of negates the point of having three other NASA centers go after validation - how are they supposed to check his results if they cannot adequately replicate the device?

One expects Sonny will be far more forthcoming with whoever is sent by the other centers to do the replication.  I would not expect him to hide anything by that time as it is not in his interest to do so.  Right now, he has continuing control over whomever gets the details, despite the thruster design is not his, and his theory cannot explain why it appears to work.  I'd say he has "managed" the situation quite expertly, even shrewdly.  If the devices work, he will try to take control of the technology despite he has no claim, and he may even succeed.  I would note to you this has happened before. 

One of the test items--I believe the one sent by Boeing to Eagle for testing--is the design of Hector Serrano.  Hector based his design on the asymmetric capacitor a la Biefeld-Brown effect.  He has had it tested at Marshall at least twice over the last decade, and as a result, NASA filed for a patent on his design.  They did the same thing on the Widom-Larsen LENR technology.  Anything they think they can patent they will, right out from under the person who showed them what works--and take special note, USG will grant those patents despite they fail the novelty requirement, since they were filed by USG.  And Sonny will do this to whomever he can if he can find something that works.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/13/2014 02:04 pm
The conclusion I am forced to draw is the scrutiny the NASA labs will do of White's QVF model will be significantly less than if he had attempted to get it into a peer review journal. Am I the only one that finds this to be a weird conclusion. Shouldn't labs be doing an equivalent level of review of another teams work before taking on the job of doing validation?

Sorry. That is a heretical viewpoint worthy of dismissal.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/13/2014 02:04 pm

Quote from: Rodal, channeling Ludwick
Set the test frequency to the start frequency, turn on the power amplifier, and wait 5 minutes or so for any thermal and current/magnetic field effects to stabilize.  Measure the residual thermal/magnetic/whatever ‘thrust’.


Again, from primitive man's "damn, I'm good department":

The amp must be operating from a standby mode, where it is ready to give as square a wave as it can as soon as it is triggered.  Otherwise, there would have to be a warm-up period for the amp, where they would have to shunt the signal elsewhere, till it got up to spec.  But they were sloppy on the frequencies, as earlier noted, so what do me know?

Quote from: Bob
On the other hand, if I were controlling the budget for spaceships in any form and was aware that at least three disparate groups had detected thrust from EmDrive-like devices, I would want to confirm or refute this thing ASAP.

Well, duh, Bob.  That's what we've been sayin' on these pages.  And I say "we" loosely, just because I happen to be in the classroom.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/13/2014 02:05 pm
...this would be shot down at any peer-reviewed journal worth a dime...

Me not know what journal you be talking about.  Not even most respected journal (http://www.madmagazine.com-sub.info/Mad/Welcome) cost only a dime.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/13/2014 02:09 pm
The conclusion I am forced to draw is the scrutiny the NASA labs will do of White's QVF model will be significantly less than if he had attempted to get it into a peer review journal. Am I the only one that finds this to be a weird conclusion. Shouldn't labs be doing an equivalent level of review of another teams work before taking on the job of doing validation?

Sorry. That is a heretical viewpoint worthy of dismissal.
I expect you're joking?  All other forms of scrutiny are significantly less than peer review.  That's why peer review is such a critical resource.  NASA has almost no physicists able to review QVF, so don't expect scrutiny there.  NASA is almost all engineers.  Real peer review needs to be done by particle physicists and that review would toss QVF out into the cold, no questions asked.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/13/2014 02:14 pm
... Am I the only one that finds this to be a weird conclusion...

Sorry. That is a heretical viewpoint...

I expect you're joking?

Him catch on quick.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/13/2014 04:58 pm
It is clear to me, that Dr. White believes he has something exciting on his hands and that he doesn't exactly know how it works. He has a theory of how it works, but who doesn't right? I think he is playing a classic risk management game, avoiding too much scrutiny. Why go full peer review with a theory that is incomplete and with a couple possible replications under foot. If I were in his shoes, I would let a few more labs try and replicate the test articles and depending on what happens next, he could go peer review. I wouldn't risk it either. I wouldn't risk my reputation or my funding. If the replications were to fail, the folly goes to Shawyer and Fetta. Eagleworks gets an after action report and lessons learned. Going peer review now is way too premature (incomplete theory) and getting shut down by a peer now could set this thing back substantially.

No doubt a real Zefram Cochrane must be a shrewd fellow.

Next subject:
Now while trying to understand dielectrics in terms of Lifshitz theory, and why PTFE is so slippery (Van der Waals forces don't work with PTFE), even to geckos and insects, I found a neat paper concerning the repulsive properties of PTFE. This paper presents Casimir repulsion between PTFE and gold with a range of liquids in between. What is exciting is that they refer to PTFE as the "material of choice" if they want to obtain strong casimir repulsion. Page 12. I found this fascinating. I don't know yet if the same treatment can be given to air as the intervening liquid or whether PE can also fall into this. I'd like to add that "Casimir repulsion" is a type of quantum levitation. Van der Waals and Casimir are very closely related and complimentary.

Anyway not making predictions here, just sharing my reading list.

http://arxiv.org/abs/1004.5243

It is clear that if EMdrive works, (if it even does work) it can't be described by a single theory, but must be described using a multidisciplinary approach. So Casimir momentum to chiral molecules is (could be) one part (previous posts), but there is more left to explain, such as why/how this momentum could be put to work in any useful way, and how this interaction is aided by turning the RF on in the cavity. There still must exist a chiral perturbation theory to explain how.

Searching for PTFE and Casimir leads to a lot of interesting results.

On the flipside, I'm trying to not fall victim to confirmation bias as much as possible.

Here's the flipside. Returning to my training in resonant cavities from way back. I remember learning three ways to tune a cavity:
1. Volume tuning (changing the size of the cavity)
2. Capacitive tuning (displacing the E field)
3. Inductive tuning (displacing the H field)

Now taking from this, I can tell you that removing the dielectric from an otherwise resonant cavity, will de-tune that cavity. And if the Nasa experimenters didn't re-tune the cavity after taking the dielectric out, they would think that the dielectric is important for there to be a "thrust." If the cavity works best by having a very high Q for example (empty cavity advocates), that would be broken. Taking the dielectric out displaces both the E and H fields of the cavity. The dielectric slug is a resonant cavity in it's own right as well. This falls into a subject called cavity perturbation theory, which is pretty complex. The Nasa paper never gave details about how they handled taking out the dielectric.

I've been researching how to compute the resonant modes of a cone. I can tell you this isn't going well. I have a neat android app called RF and Microwave toolbox that easily spits out solutions for cylinders. But as I mentioned above with tuning resonant cavities; a sloping cavity (cone) is a continuously changing displaced E or H field, depending if you're TE or TM.

So in closing, quantum postulates aside, it could really go either way. There just isn't enough information to decide what is really going on.
Title: Re: EM Drive Developments
Post by: Rodal on 11/13/2014 05:36 pm
When someone states

Quote
There just isn't enough information to decide what is really going on

what they are stating is that they cannot decide what is really going on based on the available information and their background and experience.

It would be presumptuous in the extreme for somebody to pretend to speak as to what anyone else may be able to accomplish with the same information.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/13/2014 05:39 pm
Now taking from this, I can tell you that removing the dielectric from an otherwise resonant cavity, will de-tune that cavity. And if the Nasa experimenters didn't re-tune the cavity after taking the dielectric out, they would think that the dielectric is important for there to be a "thrust." If the cavity works best by having a very high Q for example (empty cavity advocates), that would be broken.
I'm pretty sure they were specific that the Q was measured to be very high without the dielectric, which was I believe the first way they tested it.  I think they added the dielectric afterward.

And in any event, to presume they would not know what you just said is to presume they're rarther stupid when they are not.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/13/2014 05:40 pm
When someone states

Quote
There just isn't enough information to decide what is really going on

what they are stating is that they cannot decide what is really going on based on the available information and their background and experience.

It would be presumptuous in the extreme for somebody to pretend to speak as to what anyone else may be able to accomplish.

I am putting "hubris" on the table before I speak. I am not falling in love with my own theory.
Title: Re: EM Drive Developments
Post by: Rodal on 11/13/2014 05:45 pm
Now taking from this, I can tell you that removing the dielectric from an otherwise resonant cavity, will de-tune that cavity. And if the Nasa experimenters didn't re-tune the cavity after taking the dielectric out, they would think that the dielectric is important for there to be a "thrust." If the cavity works best by having a very high Q for example (empty cavity advocates), that would be broken.
I'm pretty sure they were specific that the Q was measured to be very high without the dielectric, which was I believe the first way they tested it.  I think they added the dielectric afterward.

And in any event, to presume they would not know what you just said is to presume they're rarther stupid when they are not.

No

1) They did not specify (in the "Anomalous ... " report) the Q before or after removing the dielectric

2) They did test (removing the dielectric) very early in the testing program

3) They did specify the frequency at which they performed this test (removing the dielectric) and it was a frequency much higher than for the other reported tests.  Therefore these tests (removing the dielectric) are highly questionable. 

4) Furthermore @Mulletron's concerns regarding resonance before and after are well thought out. 


Quote from:  Brady, March, White, et. al

F. Tapered Cavity RF Evaluation, General Findings and Lessons Learned
....We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust

Title: Re: EM Drive Developments
Post by: jordan.greenhall on 11/13/2014 06:02 pm
Hi all, I came here from a reddit post regarding the EM drive: http://www.reddit.com/r/EmDrive/comments/2ih0mh/rapid_spread_of_emdrive_technology_by_the_diy/

I'm interested in funding a private sector test of this tech.  Does anyone here have the capabilities of assembling a team that can create a testable EMDrive?  If so, lets talk budget.

Thanks,

Jordan Greenhall
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/13/2014 06:05 pm
Oh, I can assemble a team, all right.
Title: Re: EM Drive Developments
Post by: scienceguy on 11/13/2014 06:09 pm
They say this thing needs to be tested in space. Is that because it needs 0 g? What about testing it on an air track where there is almost no friction?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/13/2014 06:15 pm
Hi all, I came here from a reddit post regarding the EM drive: http://www.reddit.com/r/EmDrive/comments/2ih0mh/rapid_spread_of_emdrive_technology_by_the_diy/

I'm interested in funding a private sector test of this tech.  Does anyone here have the capabilities of assembling a team that can create a testable EMDrive?  If so, lets talk budget.

Thanks,

Jordan Greenhall

Hi Jordan, welcome to the group. We need intrepid individuals to help tackle this problem. Please invite your friends.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/13/2014 06:19 pm
They say this thing needs to be tested in space. Is that because it needs 0 g? What about testing it on an air track where there is almost no friction?

Well we certainly need to test this in vacuum, which can be done here on earth. Testing in space is certainly important too, that is if it can survive testing here on Earth. Welcome to the group. Please tell your friends too!
Title: Re: EM Drive Developments
Post by: Rodal on 11/13/2014 06:26 pm
I received another very interesting e-mail from Bob Ludwick, that I reproduce below:




From: Robert Ludwick
Sent: Wednesday, November 12, 2014 1:54 PM
To: Dr. J. Rodal
Subject: Testing the EmDrive

Hello Dr. Rodal

Although thrust without throwing something out the back is at least improbable (I am of course rooting for the improbable.), I think that the testing problem (to rule out heat artifacts) could be resolved by the test plan I proposed awhile back. 



i. e. 

A.  Establish the resonant frequency (s) and bandwidths of the thruster.

B.  Select a test frequency range that is at least double the bandwidth of the thruster, so that the start and stop frequencies are well outside the high Q region of the thruster.

C.  Select frequency steps so that you are guaranteed AT LEAST ten steps in the high Q region of the thruster.

D.  Set the test frequency to the start frequency, turn on the power amplifier, and wait 5 minutes or so for any thermal and current/magnetic field effects to stabilize.  Measure the residual thermal/magnetic/whatever ‘thrust’.

E.  Start the frequency sweep, with dwell times on each frequency long enough for the mechanical system to settle. Change NOTHING other than frequency.

F.  For each frequency step, record forward and reflected power from the thruster.

G.  After allowing for mechanical settling time, record the thrust.

H.  Go to the next frequency and repeat. 




If there is any ‘anomalous’ thrust related to thruster Q this procedure will detect it.  If the ‘thrust’ is due to thermal effects, it should remain constant throughout the test, as the power/current will be constant throughout the test

It DOES require a highly stable, computer controlled signal source rather than a VCO with a knob, but those, including those suitable for testing superconducting cavities, are available from any equipment rental place (such as ElectroRent) if the lab is too cheap to buy one.  Power meters, too.

I am completely baffled at the apparent disinterest of people and organizations who should be foaming at the mouth at the prospect of getting their hands on a relatively simple device that can convert microwave power into translational motion at efficiencies orders of magnitude better than simple photon rockets.  Apparently they have decided that it is prima facie impossible and therefore don’t want to waste any time or money in finding the problems in some fringe PhD’s test setup.

On the other hand, if I were controlling the budget for spaceships in any form and was aware that at least three disparate groups had detected thrust from EmDrive-like devices, I would want to confirm or refute this thing ASAP.  I’d have lab crews—more than one, at different labs, using different equipment--working overtime until I knew, one way or another, whether it was real or not.  And I would insist in more than one ‘fail’ before I called a halt.  Frankly, doing so should be cheap AND fast.  And the stakes are enormous.

Bob Ludwick
I completely agree with this except I would note that there is very serious challenge in the notion of changing frequency and NOTHING else.  Dr. Ludwick points this out, and I agree with him though I'm not sure how one would do what he suggests.

Bob Ludwick answered as follows:




From:   Robert Ludwick
Sent:   Wednesday, November 12, 2014 7:05 PM
To:   Dr. J. Rodal
Subject:   Re: Testing the EmDrive

As for the difficulty of changing the frequency and nothing else, I don’t see  it, but maybe I don’t understand the problem that is being referred to. 

To run the test, you turn on  the amplifier and all the test equipment, let it stabilize (Normally, in the labs I worked in, the sig gens et all remained powered up 24/7/365, so they didn’t require stabilization time.), and click ‘Run’ on the control computer.   The control program which you have written will ask for the start frequency,  the stop frequency, the frequency step size, and the desired output level for the signal generator driving the power amplifier.  Once those have been  entered, the computer will just execute the steps I have outlined.  Of course if you define ‘change nothing’ rigorously enough, it becomes difficult, but for the purposes of this exercise, changing the output frequency of the signal generator is done via software commands and occurs in microseconds, typically,  the drive is leveled to small fractions of a dB by the sig gen leveling circuits, and over narrow sweep ranges the variations in the current drawn by the amplifier are negligible, as are its variation in output level (which are monitored by the power meter and recorded).  So at least to a first approximation, ‘changing nothing' should be pretty simple. 

The program should run to completion, in a time depending on the number of steps and the settling time allowed for each step.  As the program runs, the computer plots a running graph of measured thrust vs frequency (while saving ALL data to a test file), so that the operator can see what’s happening in real time.

The thrust measurement in the torsional pendulum should occur under computer control, without any operator intervention, once the procedure is known. 

The only ‘moving part’ during the whole procedure is whatever mechanical movement occurs in the torsional pendulum as a response to the (hopefully) varying thrust as the frequency sweeps through thruster resonance.

The point is, with all the gory details coming with getting the thrust data back from the torsional pendulum, with my procedure everything should be steady state EXCEPT for the response of the thruster as the drive frequency sweeps through the high Q part of its frequency response.  There are no moving parts and no transients.  The current (and associated magnetic fields) to the amplifier should remain constant and the amplifier power into the thruster, and thus its heating effect, should remain constant within small fractions of a dB. 

You don’t have to worry about what material the end caps are made of, their temperature response curves, or any other material properties of the thruster, unless the measured thrust does in FACT vary with the Q at the drive frequency.  At that point, physicists need to figure out what is REALLY going on. 

On the other hand, if, after it is powered up and allowed to achieve its steady state temperature, it just hangs there doing nothing as the sig gen is stepped through the frequency of peak Q, we can all go home.
Title: Re: EM Drive Developments
Post by: Rodal on 11/13/2014 06:41 pm
Oh, I can assemble a team, all right.
What kind of a team can you assemble?

Who is on your team?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/13/2014 07:27 pm
No

1) They did not specify (in the "Anomalous ... " report) the Q before or after removing the dielectric

2) They did test (removing the dielectric) very early in the testing program

3) They did specify the frequency at which they performed this test (removing the dielectric) and it was a frequency much higher than for the other reported tests.  Therefore these tests (removing the dielectric) are highly questionable. 

4) Furthermore @Mulletron's concerns regarding resonance before and after are well thought out. 
No.  The dielectric slows the em through it, so the chamber is effectively a higher frequency chamber without it.  It is presuming the folks at Eagle are stupid in the extreme to think they would not note this most obvious issue.
Title: Re: EM Drive Developments
Post by: Rodal on 11/13/2014 07:38 pm
No

1) They did not specify (in the "Anomalous ... " report) the Q before or after removing the dielectric

2) They did test (removing the dielectric) very early in the testing program

3) They did specify the frequency at which they performed this test (removing the dielectric) and it was a frequency much higher than for the other reported tests.  Therefore these tests (removing the dielectric) are highly questionable. 

4) Furthermore @Mulletron's concerns regarding resonance before and after are well thought out. 
No.  The dielectric slows the em through it, so the chamber is effectively a higher frequency chamber without it.  It is presuming the folks at Eagle are stupid in the extreme to think they would not note this most obvious issue.

Why didn't "the folks at Eagleworks" report the Q with and without the dielectric in their report?

as you expected:

Quote from: Ron Stahl
I'm pretty sure they were specific that the Q was measured to be very high without the dielectric  , which was I believe the first way they tested it.

You seem to have information from other sources that does not emanate from the "Anomalous..." report:

Where in the report are they so specific concerning the Q measured to be very high without the dielectric?

Please give the page in where that is stated

Title: Re: EM Drive Developments
Post by: Mulletron on 11/13/2014 07:43 pm
Posting this again.
https://www.fourmilab.ch/gravitation/foobar/

This is a DIY on how to build your own torsion balance at home. This setup is sensitive enough to measure the gravitation between chunks of lead. Good enough to measure "anomalous thrust" if you so desire to build your own test article.
Title: Re: EM Drive Developments
Post by: Rodal on 11/13/2014 07:48 pm
Posting this again.
https://www.fourmilab.ch/gravitation/foobar/

This is a DIY on how to build your own torsion balance at home. This setup is sensitive enough to measure the gravitation between chunks of lead. Good enough to measure "anomalous thrust" if you so desire to build your own test article.

Good info.  Much more similar to the classical Cavendish setup.

No Christmas-tree with hanging ornaments setup.
No 1.5 by 1.5 inch Faztek long cantilevered beam sticking out with the EM Drive at the end. 
No C-Flex Riverhawk with uncertain spring constant.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/13/2014 07:56 pm
Posting this again.
https://www.fourmilab.ch/gravitation/foobar/

This is a DIY on how to build your own torsion balance at home. This setup is sensitive enough to measure the gravitation between chunks of lead. Good enough to measure "anomalous thrust" if you so desire to build your own test article.

Good info.  The classical Cavendish setup.

No Christmas-tree with hanging ornaments setup.
No 1.5 by 1.5 inch Faztek long cantilevered beam sticking out with the EM Drive at the end. 
No C-Flex Riverhawk with uncertain spring constant.

Well, I certainly have vacuum chambers .......
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/13/2014 08:13 pm
You seem to have information from other sources that does not emanate from the "Anomalous..." report:

Where in the report are they so specific concerning the Q measured to be very high without the dielectric?

Please give the page in where that is stated

I know Paul.  He was my mentor for two years.  We still pass notes from time to time.  If my memory was accessing stuff we discussed rather than the paper, that is my whoops.  Just saying, these are not the kinds of mistakes Paul nor anyone at Eagle would make.  If you have to presume they are stupid, your presumption will be wrong.

Sonny's model does not require anything in the chamber.  It is Paul who believes QVF and M-E theory are opposite sides of the same coin, who pressed to put a dielectric in the resonator.  He chose something with a fairly linear response, so he wouldn't have the difficulties of frequency dependence, etc.  In this he once mentioned he was looking at Teflon.  If I say more without rereading the report I might stumble upon something I was not meant to share, so lets leave it there, shall we?

it is worth noting just as Mulletron says, one can tune these sorts of cavities by putting in some dielectric.  If one wants to do a parametric study with changing frequency, the simplest way is to place varying amounts of dielectric thickness in, and then use the PPL circuit to find the resonance.  I know they're using PPL resonance tuning, so it would appear they intend to do this kind of study.  Lets remember, they only got the rig up and running a few days before this paper.  They should already have done much more since the paper than they did before it.  And note too, this method does not change only the frequency, so analysis of the generated data will be more difficult to interpret than what Dr. Ludwick was hoping for.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/13/2014 11:45 pm
The sweeping methodology sounds nice, but a "simple" longer power on test could learn a lot too. What is the record of time with power on for any of the propellentless devices so far ? Why not try to let it run for longer than a few 10s of seconds ? 10 minutes, 1 hour ? 20W is not that much power to reach equilibrium and dissipate from inside a box of metal like a vacuum chamber...

Or is it the stability of the resonance that can't be kept that long ? And while I'm at it, what is the most convincing experimental proof so far that those devices really need to be operated at resonance ? I remember my search on fitting formulas did show a strong correlation with Q but it was only on 7 or 6 data points. And correlation with Q don't mean correlation with resonance : we can have a high Q cavity driven off resonance. Actually the higher the Q the higher the risk that it is driven off resonance.

I'm thinking of the results of Juan 2012 (http://www.emdrive.com/yang-juan-paper-2012.pdf) that did a parameter study on power input but that turns out to be a correlated parameter study on frequency since the power spectrum of their source varied with power output (output from source, input to cavity). They analyse the strong non linearity and even non monotonicity of their graph thrust vs power (fig 4 page 8 ) as the result of this complex frequency dependence on power of their source (fig 6 page 9). BTW, we see a number of data points on the fig 4 that's impressive when compared to what "anomalous thrust..." has to offer. On the other hand we are not gratified with a thrust vs time for pulses. Not clear, did they swept on power and recorded whopping hundreds milliNewtons all the way through ? For how long ? Need to read in detail again. Also the (a) and (b) curves of figure 4 are not in complete agreement, different sources ? Unfortunately the curves labels on fig 4 are not translated, multiple runs ?

Anyway, from what I understand it states that the experimental resonance is at 2.450GHz and experimental bandwidth is 2.4492 to 2.4508GHz (that is delta_f= 0.0016GHz, that would be Q=2.45/.0016=1531 only, not specially "high Q", have I missed something ???). And yet we see (hardly) from fig 6 page 9 that most of the source power (experimental) is outside this narrow window. Measured thrusts vs raw power do roughly follow the amount of power effectively in the resonance window (dependant on raw power) as discussed page 10.

Albeit I have a hard time at interpreting the vertical scales of fig. 6. For instance fig. 6 (b) (top right) shows what's going on at 300W raw power (again if I understand anything at all) which gives supposedly the higher "yield" in resonance bandwidth (little insert box). The text page 10 tells that the "actual maximum output power of the microwave source" (I interpret that as being the part of power in resonance) of 120W. But from the overall graph of fig 6 (b) we can't really see one third of power in the window, more like 2 or 3% (10W, not 120W) Most of the spectrum content is above 2.454, way above the bandwidth... The overall given power (not just on the resonance window) is also varying with raw power when looking at the vertical scales (that don't make sense for a spectrum : should be Watts per Hz, not Watts). Is a magnetron exhibiting such nonlinearities in overall RF power vs input power ?

I'm getting tired of those broken reports, or is it me ? Anyone willing to either confirm those inconsistencies or explain what is going on with Q and bandwidth and resonance on this report ? That Juan report was source of 2 of the 6 (or 7 with the "statistical oulier Brady b") that was used to get a grip on the parameters mutual dependencies with Mac Culloch's formula and with exhaustive searches...

If I'm interpreting the graphs of Juan et al 2012 at face value, we have either an effect that don't care that much on seeing most of its power being at some resonance or not (and that don't care having a Q of 1530). Or we have an effect that uses just the resonance part (the gross fraction that is off resonance is just wasted heat) and what I see is on the order of 10Watts (with a clean efficient source modestly tuned to Q 1530) to get 300mN, a staggering 30 N/kW. Round trip to Saturn in two weeks anyone ? 8)

ps. they do appear to use an inverted pendulum, ahem, that is with centre of gravity clearly above pivot + a flex bearing with stiffness to compensate the unstability. If I get it, they try to have a "metastable" equilibrium point to increase sensitivity ? Why would they need/want such sensitivity to measure 10s of millinewton ? (many gram-force !)
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/14/2014 12:40 am
Quote
Hi all, I came here from a reddit post regarding the EM drive: http://www.reddit.com/r/EmDrive/comments/2ih0mh/rapid_spread_of_emdrive_technology_by_the_diy/

I'm interested in funding a private sector test of this tech.  Does anyone here have the capabilities of assembling a team that can create a testable EMDrive?  If so, lets talk budget.

Quote

They say this thing needs to be tested in space. Is that because it needs 0 g? What about testing it on an air track where there is almost no friction?

While there have been a couple of DIY types who dropped into this thread, most of the people posting are concerned with trying to figure out how and why the device works in the first place, and whether or not the reported results are the result of a 'false positive' or experimental artifact.

It must be pointed out that the explanations put forth by the creators of these devices run directly contrary to major, well established scientific laws, notably 'conservation of momentum.'  That said, the reported results, from different
groups in different countries using devices differing somewhat from each other did produce what APPEARS to be positive results.  The problem is reconciling or explaining those results in a manner consistent with known science.

Several options have been investigated to a greater or lesser extent over the past 150 pages or so of this thread.  These include:

1) The EM Drive is pushing against 'Dark Matter,' which is just barely workable if there is a lot of Dark Matter in the area.

2)  The EM Drive is a sort of Biefield - Brown device, essentially a high voltage all electric aircraft that fly's by ionizing the air underneath it.  These devices are legitimate; hobbyist of various sorts have been making the things for decades.  You can find videos of them in action on You-Tube under 'anti-gravity.'  This possibility was rejected because the EM Drive devices are low voltage mechanisms - simply not enough power.  Also, a Biefield-Brown device won't function in a vacuum. 

3) The EM Drive...attracts...'Unruh Radiation,' a theoretical 'force' behind Inertia.  This explanation gets into known cosmological problems involving expanding space-time.  One effect: despite gravitational attraction, galaxies are being 'pushed' away from each other at a constant rate roughly equal to 1 kilometer per second.  A Doctor McCulloch, noted physicist and occasional poster in this thread has published papers using Unruh Radiation as a means to explain tiny anomalies in the velocities of several spacecraft.  However, this effect, while fascinating, is both unconfirmed and probably confined to 'deep space' - at least by the posters here.

4) One or two posters here have recently begun looking again into the possibility the EM Drive may, after all, really be tapping into the Quantum Vacuum.  However, there remain severe problems with this.

5) The explanation most closely looked at now is that the effects produced by the EM Drive are a thermal artifact compounded by a flawed measuring device.  According to this hypothesis, the devices should produce miniscule amounts of thrust in an atmosphere, and no thrust at all in space, making it effectively worthless as a space propulsion system. 

It is also worth pointing out that the experimenters have been withholding key data about their devices, making independent verification difficult.  A EM Drive device probably could be built on a modest budget; the question is whether it would work.
















Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/14/2014 01:55 am
Oh, I can assemble a team, all right.
1) What kind of a team can you assemble?

2) Who is on your team?

1)  The best.

2) Top men.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/14/2014 02:46 am
This is the consequence of all the forces of physics being gauge invariant: absolute values don't exist--only differences matter.  (https://www.fourmilab.ch/gravitation/foobar/)

Correct me if memory fails; this fellow wrote AutoCAD, which I've used to gracxe these pages here and there.

This is an example of why I continue to insist on the paramount importance of stating principles in English before devolving to math. Everything that needs to be said, and that has to be saod. should be reduced to English.

Sorry Frob.  French is fine in France, but dis be Amerika.

 Given the philosophical implications of Newton's theory, it's interesting to speculate what might have happened had Archimedes discovered the universal nature of gravitation. (https://www.fourmilab.ch/gravitation/foobar/)

Other brains besides mine have speculated on what I call the "Spartacus Conjecture".  Mankind was already smart enough to attempt off planet travel and colonizxation as early as 0AD/BC.

Bottom line?  Take your math and shove it! (https://www.fourmilab.ch/gravitation/foobar/figures/movie-3r.mov)

With the deepest respect for the utility and necessity of math.

Would such a discovery in Archimedes' time have had an impact comparable to Newton's or, occurring in a very different social and intellectual milieu, would it have been regarded as no more than a curiosity? How might human history have played out had the Enlightenment begun 1900 years before Newton?  (https://www.fourmilab.ch/gravitation/foobar/)

All it takes is three hundred years to start colonizing the solar system.  Why haven't we?  We're being kept on planet.

But I digress.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/14/2014 02:49 am
The sweeping methodology sounds nice, but a "simple" longer power on test could learn a lot too. What is the record of time with power on for any of the propellentless devices so far ?

Me thank.  Me not get pragmatic utility of "xx" ms or whatever of power input.  Me think must have device on for many moons before get anywhere interesting.

That being if even can detect force period.
Title: Re: EM Drive Developments
Post by: ChrisWilson68 on 11/14/2014 03:01 am
Oh, I can assemble a team, all right.
What kind of a team can you assemble?

Who is on your team?

This is an example of why I continue to insist on the paramount importance of stating principles in English before devolving to math. Everything that needs to be said, and that has to be saod. should be reduced to English.

All it takes is three hundred years to start colonizing the solar system.  Why haven't we?  We're being kept on planet.

Rodal, I think this should be enough to answer your questions about John.
Title: Re: EM Drive Developments
Post by: zen-in on 11/14/2014 04:30 am
I received another very interesting e-mail from Bob Ludwick, that I reproduce below:




From: Robert Ludwick
Sent: Wednesday, November 12, 2014 1:54 PM
To: Dr. J. Rodal
Subject: Testing the EmDrive

Hello Dr. Rodal

Although thrust without throwing something out the back is at least improbable (I am of course rooting for the improbable.), I think that the testing problem (to rule out heat artifacts) could be resolved by the test plan I proposed awhile back. 



i. e. 

A.  Establish the resonant frequency (s) and bandwidths of the thruster.

B.  Select a test frequency range that is at least double the bandwidth of the thruster, so that the start and stop frequencies are well outside the high Q region of the thruster.

C.  Select frequency steps so that you are guaranteed AT LEAST ten steps in the high Q region of the thruster.

D.  Set the test frequency to the start frequency, turn on the power amplifier, and wait 5 minutes or so for any thermal and current/magnetic field effects to stabilize.  Measure the residual thermal/magnetic/whatever ‘thrust’.

E.  Start the frequency sweep, with dwell times on each frequency long enough for the mechanical system to settle. Change NOTHING other than frequency.

F.  For each frequency step, record forward and reflected power from the thruster.

G.  After allowing for mechanical settling time, record the thrust.

H.  Go to the next frequency and repeat. 




If there is any ‘anomalous’ thrust related to thruster Q this procedure will detect it.  If the ‘thrust’ is due to thermal effects, it should remain constant throughout the test, as the power/current will be constant throughout the test

It DOES require a highly stable, computer controlled signal source rather than a VCO with a knob, but those, including those suitable for testing superconducting cavities, are available from any equipment rental place (such as ElectroRent) if the lab is too cheap to buy one.  Power meters, too.

I am completely baffled at the apparent disinterest of people and organizations who should be foaming at the mouth at the prospect of getting their hands on a relatively simple device that can convert microwave power into translational motion at efficiencies orders of magnitude better than simple photon rockets.  Apparently they have decided that it is prima facie impossible and therefore don’t want to waste any time or money in finding the problems in some fringe PhD’s test setup.

On the other hand, if I were controlling the budget for spaceships in any form and was aware that at least three disparate groups had detected thrust from EmDrive-like devices, I would want to confirm or refute this thing ASAP.  I’d have lab crews—more than one, at different labs, using different equipment--working overtime until I knew, one way or another, whether it was real or not.  And I would insist in more than one ‘fail’ before I called a halt.  Frankly, doing so should be cheap AND fast.  And the stakes are enormous.

Bob Ludwick
I completely agree with this except I would note that there is very serious challenge in the notion of changing frequency and NOTHING else.  Dr. Ludwick points this out, and I agree with him though I'm not sure how one would do what he suggests.

Bob Ludwick answered as follows:




From:   Robert Ludwick
Sent:   Wednesday, November 12, 2014 7:05 PM
To:   Dr. J. Rodal
Subject:   Re: Testing the EmDrive

As for the difficulty of changing the frequency and nothing else, I don’t see  it, but maybe I don’t understand the problem that is being referred to. 

To run the test, you turn on  the amplifier and all the test equipment, let it stabilize (Normally, in the labs I worked in, the sig gens et all remained powered up 24/7/365, so they didn’t require stabilization time.), and click ‘Run’ on the control computer.   The control program which you have written will ask for the start frequency,  the stop frequency, the frequency step size, and the desired output level for the signal generator driving the power amplifier.  Once those have been  entered, the computer will just execute the steps I have outlined.  Of course if you define ‘change nothing’ rigorously enough, it becomes difficult, but for the purposes of this exercise, changing the output frequency of the signal generator is done via software commands and occurs in microseconds, typically,  the drive is leveled to small fractions of a dB by the sig gen leveling circuits, and over narrow sweep ranges the variations in the current drawn by the amplifier are negligible, as are its variation in output level (which are monitored by the power meter and recorded).  So at least to a first approximation, ‘changing nothing' should be pretty simple. 

The program should run to completion, in a time depending on the number of steps and the settling time allowed for each step.  As the program runs, the computer plots a running graph of measured thrust vs frequency (while saving ALL data to a test file), so that the operator can see what’s happening in real time.

The thrust measurement in the torsional pendulum should occur under computer control, without any operator intervention, once the procedure is known. 

The only ‘moving part’ during the whole procedure is whatever mechanical movement occurs in the torsional pendulum as a response to the (hopefully) varying thrust as the frequency sweeps through thruster resonance.

The point is, with all the gory details coming with getting the thrust data back from the torsional pendulum, with my procedure everything should be steady state EXCEPT for the response of the thruster as the drive frequency sweeps through the high Q part of its frequency response.  There are no moving parts and no transients.  The current (and associated magnetic fields) to the amplifier should remain constant and the amplifier power into the thruster, and thus its heating effect, should remain constant within small fractions of a dB. 

You don’t have to worry about what material the end caps are made of, their temperature response curves, or any other material properties of the thruster, unless the measured thrust does in FACT vary with the Q at the drive frequency.  At that point, physicists need to figure out what is REALLY going on. 

On the other hand, if, after it is powered up and allowed to achieve its steady state temperature, it just hangs there doing nothing as the sig gen is stepped through the frequency of peak Q, we can all go home.

I agree with most of the above.   However there is one problem with stepping the frequency.  The chamber has a very high Q so any RF power that is outside the very narrow passband will be reflected.   Maybe this is the reason why the em-drive didn't produce any "anomalous thrust" when the dielectric was removed:  The passband shifted.    I still think the best control for this experiment would be a 50 Watt resistor inside the chamber, fastened to the same location as the RF feed.    Apply a DC voltage to this resistor so that the same power is dissipated inside the chamber.   Is a thrust measured under this set of conditions?
Title: Re: EM Drive Developments
Post by: aceshigh on 11/14/2014 10:50 am
Hi all, I came here from a reddit post regarding the EM drive: http://www.reddit.com/r/EmDrive/comments/2ih0mh/rapid_spread_of_emdrive_technology_by_the_diy/

I'm interested in funding a private sector test of this tech.  Does anyone here have the capabilities of assembling a team that can create a testable EMDrive?  If so, lets talk budget.

Thanks,

Jordan Greenhall

are you the Jordan Greenhall who founded DivX?
Title: Re: EM Drive Developments
Post by: aceshigh on 11/14/2014 11:01 am
It is also worth pointing out that the experimenters have been withholding key data about their devices, making independent verification difficult.  A EM Drive device probably could be built on a modest budget; the question is whether it would work.

the question is what sort of budget would be needed to build in theory a stronger enough EM device that could give conclusive results about it working or not.

why haven´t White or someone else build a device giving away 1 N and just appear on a press conference on a magic carpet floating over EM devices :) ? Because they don´t KNOW how to do it or because of budget constraints? Or they don´t know how to do it BECAUSE of budget constraints?


every investment means a risk... investment on an EM Device, since they are still unproved, is a big risk. It should be clear to investors this is an INVESTIGATION if it works or not (unlike Rossi trying to get money from investors by claiming his ECAT DOES work.)

of course, if the investigation to reach conclusive proof are low budget enough, and the pay-off might be ENORMOUS (founding your own Wayland Yutani Corporation haha), the very high risk may be worth a try.

people have been know to gamble a lot of money on much riskier things, like horse racing, soccer and Las Vegas
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 11:59 am
Oh, I can assemble a team, all right.
1) What kind of a team can you assemble?

2) Who is on your team?

1)  The best.

2) Top men.

Women don't need to apply for your team ?
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/14/2014 12:04 pm
i believe that is pop cultural reference to a line in a movie.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/14/2014 12:05 pm
Oh, I can assemble a team, all right.
1) What kind of a team can you assemble?

2) Who is on your team?

1)  The best.

2) Top men.

Women don't need to apply for your team ?

Women (http://www.youtube.com/watch?v=M55lon6qUNg)?  I've heard of them.  And in fact, they are running my team at the moment and for the foreseeable future.  It's a complicated, multi-coastal thing.  No math whatsoever.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/14/2014 12:07 pm
Rodal, I think this should be enough to answer your questions about John.

Him still think math invented before language.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/14/2014 12:10 pm
Oh.  Tryouts for the team are underway.  Use the PM function.  Must be willing to travel to the Hook (http://en.wikipedia.org/wiki/The_Hook_%28newspaper%29).  Must have English, manufacturing, math, and a sense of Arizona.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/14/2014 12:53 pm
It is also worth pointing out that the experimenters have been withholding key data about their devices, making independent verification difficult.  A EM Drive device probably could be built on a modest budget; the question is whether it would work.

the question is what sort of budget would be needed to build in theory a stronger enough EM device that could give conclusive results about it working or not.

why haven´t White or someone else build a device giving away 1 N and just appear on a press conference on a magic carpet floating over EM devices :) ? Because they don´t KNOW how to do it or because of budget constraints? Or they don´t know how to do it BECAUSE of budget constraints?


This is not a matter of stronger but reliable, reproducible, and conclusive, yes, as a form of unknown physics.

Shawyer (2008) and Juan et al team (2011) are claiming thrusts 0.2 N or a little more, not far from 1N. It's been said that those devices are hard to make reliable because of narrow resonance bandwidth and hard to maintain at resonance, and hard to make standalone with all battery+RF amplifier+cavity(+thermal management...) in a package with only on/off remote control as interaction. I understand this would not be trivial to do, but hard to swallow that it proved that difficult to do in all those years.

Publish one single design with reproducible clean 1µN from 1W (operational for a few hours) and all leading private and public labs will exponentially rush on that unknown physics as soon as two or three independent labs with known sceptics at the command confirm something is going on. And that shouldn't take more than a few tens of thousands of dollar.

The most probable answer is that they don't know how to do it because it don't work as claimed (ie. no exotic physics, no application to propulsion, no application to energy generation). No matter how much money is thrown at it, impossible is impossible. And most lab chose to throw no money at it at all. Or if they did, they got negative results and kept silence about that, because there is not much credit to gain from publishing negative results, specially when everybody is convinced the results should be negative. Or they already got positive results and kept silence, for the moment, but in this case it shouldn't take long before it leaks.

Quote

every investment means a risk... investment on an EM Device, since they are still unproved, is a big risk. It should be clear to investors this is an INVESTIGATION if it works or not (unlike Rossi trying to get money from investors by claiming his ECAT DOES work.)

of course, if the investigation to reach conclusive proof are low budget enough, and the pay-off might be ENORMOUS (founding your own Wayland Yutani Corporation haha), the very high risk may be worth a try.

people have been know to gamble a lot of money on much riskier things, like horse racing, soccer and Las Vegas

Yeah, managed well, king of the solar system is not out of reach. Also, should it work as claimed there would be very serious issues with devastating kinetic weapons "for everyone"... so this is also a high risk/high risk gamble.

If this is serious, at this stage it is fundamental science, not engineering. People are waiting (well, most people aren't waiting for anything from this line of research) for a reliable and reproducible effect, even small, not for a strong effect but not reliable and not reproducible.

Premature optimization is the root of all evil -- Donald Knuth
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/14/2014 01:22 pm
It is also worth pointing out that the experimenters have been withholding key data ...

The question is what sort of budget would be needed to build in theory a stronger enough EM device that could give conclusive results about it working or not.

why haven´t White or someone else built a device giving away 1 N and just appear on a press conference on a magic carpet floating over EM devices :) ? Because they don´t KNOW how to do it or because of budget constraints? Or they don´t know how to do it BECAUSE of budget constraints?

I have already answered this question briefly:

As someone said before and in agreement on the experimentalist side of things...
Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust?
We wouldn't need vacuum chambers or any nonsense.
Why not?

Why not?  Because...

...why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?

Seriously, this time:

The cost and difficulty of scaling to that degree is prohibitive.

A careful reading of your line of questioning reveals to me some inaccuracy in your approach.

You ask, "bcause they don´t KNOW how to do it or because of budget constraints".  Budget is not the cause for lack of results.  If they do know how to do it  (not that "do it") they have not so demonstrated the phenomena.

The potential economic stakes are very high, but the theoretical costs, if you will, are also very high.  One side effect of this is that the NASA people who direct funding are in a bit of a bind, because the math is so impenetrable, but the risks of missing out on a rewrite of physics are so formidable.  Quite frankly, they ain't got what it takes to know for sure whether the effect is real or not.

What happens is that NASA people do not question the math sufficiently, by my take.  Just to pick one random example:  Primitive man was not so sure of his skills in questioning the handling of a simple equation, and didn't raise the point, but another fella with vastly superior math skills spotted a serious error which should have, one would think, have caused the NASA people to question the work of the experimentors more closely.

Except for one point : since when do you measure a change by subtracting a final amount from an initial amount ? (http://forum.nasaspaceflight.com/index.php?topic=29276.msg1285185#msg1285185)

It would be a logical mistake to think that cost is immaterial in the demonstration of the experimental apparatus and protocol.  But, as was illustrated on John Walker's site up thread, a very primitive methodology can be used to detect the effects of very small gravitational forces, or forces from an EM drive device.   There's no way that the electronic gear could be had for around $2K, as one poster up thread suggested.

Still, it seems that the expense of replicating the results using the many suggestions in this thread, should not be insurmountable.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 01:41 pm
Not clear, did they swept on power and recorded whopping hundreds milliNewtons all the way through ?
No.  All of the highest thrusts were impulse associated with the on and off transients, which according to M-E theory is just what should happen if this is a Mach Effect Thruster.  The impulses were not "hundreds' of milliNewtons.  I think the highest impulse recored was 110mN.  That is a respectable, commercial grade thrust given most communications sats are fitted with 20nM Hall thrusters.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 01:57 pm
From:   Robert Ludwick
Sent:   Wednesday, November 12, 2014 7:05 PM
To:   Dr. J. Rodal
Subject:   Re: Testing the EmDrive

As for the difficulty of changing the frequency and nothing else, I don’t see  it, but maybe I don’t understand the problem that is being referred to.
I think he's right.  He doesn't understand.  This is a very high Q resonator.  The higher the Q, the narrower the bandwidth it can resonate at.  Without resonance the Q will drop off to between 1/100  and 1/10,000 what it is normally.  The resonator needs to resonate.  You cannot simply sweep a resonator and think you are changing the frequency only, when the Q is only for small bandwidths of specific frequencies. 

The proper way to do the kind of study Dr. Ludwick mentions is as I already explained, place varying amounts of dielectric in the chamber so it has different resonant frequencies and plot points rather than a sweep.  Since Eagle has a PLL resonance matching circuit, there is little trouble with this except that you need to note you have not one but two variables as you have changed the amount of active mass.  According to M-E theory this should matter, and Paul knows this.
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 02:16 pm
Not clear, did they swept on power and recorded whopping hundreds milliNewtons all the way through ?
No.  All of the highest thrusts were impulse associated with the on and off transients, which according to M-E theory is just what should happen if this is a Mach Effect Thruster....
No. Not in general for microwave EM Drive reported results.

The record shows otherwise.  See for example the following force measurement by Shawyer, showing instead of just an impulse, an increasing (very slowly with time when compared to electromagnetic wave speed) force response, as has been noticed and commented in this forum numerous times by @Mulletron, @aero, @zen-in, @frobnicat and others in this thread.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 02:21 pm
Quote
Hi all, I came here from a reddit post regarding the EM drive: http://www.reddit.com/r/EmDrive/comments/2ih0mh/rapid_spread_of_emdrive_technology_by_the_diy/

I'm interested in funding a private sector test of this tech.  Does anyone here have the capabilities of assembling a team that can create a testable EMDrive?  If so, lets talk budget.

Quote

They say this thing needs to be tested in space. Is that because it needs 0 g? What about testing it on an air track where there is almost no friction?

While there have been a couple of DIY types who dropped into this thread, most of the people posting are concerned with trying to figure out how and why the device works in the first place, and whether or not the reported results are the result of a 'false positive' or experimental artifact.

It must be pointed out that the explanations put forth by the creators of these devices run directly contrary to major, well established scientific laws, notably 'conservation of momentum.'  That said, the reported results, from different
groups in different countries using devices differing somewhat from each other did produce what APPEARS to be positive results.  The problem is reconciling or explaining those results in a manner consistent with known science.

Several options have been investigated to a greater or lesser extent over the past 150 pages or so of this thread.  These include:

1) The EM Drive is pushing against 'Dark Matter,' which is just barely workable if there is a lot of Dark Matter in the area.

2)  The EM Drive is a sort of Biefield - Brown device, essentially a high voltage all electric aircraft that fly's by ionizing the air underneath it.  These devices are legitimate; hobbyist of various sorts have been making the things for decades.  You can find videos of them in action on You-Tube under 'anti-gravity.'  This possibility was rejected because the EM Drive devices are low voltage mechanisms - simply not enough power.  Also, a Biefield-Brown device won't function in a vacuum. 

3) The EM Drive...attracts...'Unruh Radiation,' a theoretical 'force' behind Inertia.  This explanation gets into known cosmological problems involving expanding space-time.  One effect: despite gravitational attraction, galaxies are being 'pushed' away from each other at a constant rate roughly equal to 1 kilometer per second.  A Doctor McCulloch, noted physicist and occasional poster in this thread has published papers using Unruh Radiation as a means to explain tiny anomalies in the velocities of several spacecraft.  However, this effect, while fascinating, is both unconfirmed and probably confined to 'deep space' - at least by the posters here.

4) One or two posters here have recently begun looking again into the possibility the EM Drive may, after all, really be tapping into the Quantum Vacuum.  However, there remain severe problems with this.

5) The explanation most closely looked at now is that the effects produced by the EM Drive are a thermal artifact compounded by a flawed measuring device.  According to this hypothesis, the devices should produce miniscule amounts of thrust in an atmosphere, and no thrust at all in space, making it effectively worthless as a space propulsion system. 

It is also worth pointing out that the experimenters have been withholding key data about their devices, making independent verification difficult.  A EM Drive device probably could be built on a modest budget; the question is whether it would work.
None of these explanations appeal because as you said, they violate broadly accepted physical principles such as conservation and Einstein's Equivalence Principle and General Relativity.  However, the explanation you missed is the Mach Effect explanation, and it does not violate any well understood physics.  It in fact requires conservation, GR and EEP all obtain.  Also the fact these thruster seem to require the dielectric, and work best during the on and off transients, suggests this is a Mach Effect we're looking at.
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 02:56 pm
Quote
Hi all, I came here from a reddit post regarding the EM drive: http://www.reddit.com/r/EmDrive/comments/2ih0mh/rapid_spread_of_emdrive_technology_by_the_diy/

I'm interested in funding a private sector test of this tech.  Does anyone here have the capabilities of assembling a team that can create a testable EMDrive?  If so, lets talk budget.

Quote

They say this thing needs to be tested in space. Is that because it needs 0 g? What about testing it on an air track where there is almost no friction?

While there have been a couple of DIY types who dropped into this thread, most of the people posting are concerned with trying to figure out how and why the device works in the first place, and whether or not the reported results are the result of a 'false positive' or experimental artifact.

It must be pointed out that the explanations put forth by the creators of these devices run directly contrary to major, well established scientific laws, notably 'conservation of momentum.'  That said, the reported results, from different
groups in different countries using devices differing somewhat from each other did produce what APPEARS to be positive results.  The problem is reconciling or explaining those results in a manner consistent with known science.

Several options have been investigated to a greater or lesser extent over the past 150 pages or so of this thread.  These include:

1) The EM Drive is pushing against 'Dark Matter,' which is just barely workable if there is a lot of Dark Matter in the area.

2)  The EM Drive is a sort of Biefield - Brown device, essentially a high voltage all electric aircraft that fly's by ionizing the air underneath it.  These devices are legitimate; hobbyist of various sorts have been making the things for decades.  You can find videos of them in action on You-Tube under 'anti-gravity.'  This possibility was rejected because the EM Drive devices are low voltage mechanisms - simply not enough power.  Also, a Biefield-Brown device won't function in a vacuum. 

3) The EM Drive...attracts...'Unruh Radiation,' a theoretical 'force' behind Inertia.  This explanation gets into known cosmological problems involving expanding space-time.  One effect: despite gravitational attraction, galaxies are being 'pushed' away from each other at a constant rate roughly equal to 1 kilometer per second.  A Doctor McCulloch, noted physicist and occasional poster in this thread has published papers using Unruh Radiation as a means to explain tiny anomalies in the velocities of several spacecraft.  However, this effect, while fascinating, is both unconfirmed and probably confined to 'deep space' - at least by the posters here.

4) One or two posters here have recently begun looking again into the possibility the EM Drive may, after all, really be tapping into the Quantum Vacuum.  However, there remain severe problems with this.

5) The explanation most closely looked at now is that the effects produced by the EM Drive are a thermal artifact compounded by a flawed measuring device.  According to this hypothesis, the devices should produce miniscule amounts of thrust in an atmosphere, and no thrust at all in space, making it effectively worthless as a space propulsion system. 

It is also worth pointing out that the experimenters have been withholding key data about their devices, making independent verification difficult.  A EM Drive device probably could be built on a modest budget; the question is whether it would work.
None of these explanations appeal because as you said, they violate broadly accepted physical principles such as conservation and Einstein's Equivalence Principle and General Relativity.  However, the explanation you missed is the Mach Effect explanation, and it does not violate any well understood physics.  It in fact requires conservation, GR and EEP all obtain.  Also the fact these thruster seem to require the dielectric, and work best during the on and off transients, suggests this is a Mach Effect we're looking at.
No.

Actually ThinkerX thoughtfully wrote that " The explanation most closely looked at "  is that the EM Drive measured response is a thermal artifact.

It is incorrect to state that classical physics thermal effects "violate broadly accepted physical principles such as conservation and Einstein's Equivalence Principle and General Relativity".  Thermal effects don't violate any such laws and/or principles.

On the contrary, the thermal effect explanation "appeals" because of Occam's razor:  the researchers should spend much more time analyzing classical physics explanations rather than exotic physics that are not generally accepted in the scientific community.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 02:56 pm
Publish one single design with reproducible clean 1µN from 1W (operational for a few hours) and all leading private and public labs will exponentially rush on that unknown physics as soon as two or three independent labs with known sceptics at the command confirm something is going on. And that shouldn't take more than a few tens of thousands of dollars.

This is much more difficult and much more expensive than you understand.  Just the high speed automatcher used up at George Hathaway's lab cost $150k.  And make no mistake, it is the power equipment that one presumes should be easy enough to build, that costs so much.  It was a big breakthrough for Eagle to get their PLL circuit in place and this is something Woodward has never been able to do.

And for Jourdan's sake let me note that providing vacuum can be extremely complex.  The presumption in the industry is normally to go for relatively hard vacuum, E-6T to E-9T, at a cost of more than $150k.  (Eagle spent this money and built the chamber, but never sucked it out because the test articles were not vacuum certified.)    Fact is, if you don't see a signal change from normal atmo to E-3T, you know you don't have ion wind, thermal, etc., so you don't really need harder vacuum.  If you are involved in a private investigation, better to spend the cash on the power system and when you need really hard vacuum, go see NASA.  All science is a social activity and there's no reason for every lab to have hard vacuum.  Also, if you are contented with E-5T, you can go with a polycarbonate chamber and can then put much of the instrumentation outside the chamber.  This avoids all kinds of trouble.  By using a poly chamber and moving the instruments away from the balance, you can qualify your rig in about 1/3 the time and reduce your setup costs by about 1/2.  Also if you intend to test M-E, you can then use a doppler vibrometer, and other gear that you would normally never put into a vacuum chamber.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 03:02 pm
No. Not in general for microwave EM Drive reported results.

The record shows otherwise. . .
I was just speaking of the work at Eagle as this is what Paul told me.  All the largest thrusts were from the switching transients.  Since M-E theory predicts this, Woodward filed for a patent on a pulsed AC power system.  I don;t know if in his patent he reverses the off transient or extinguishes it, but the two generate pulses in opposite directions (again, according to theory) so he must have dealt with it somehow.
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 03:09 pm
No. Not in general for microwave EM Drive reported results.

The record shows otherwise. . .
I was just speaking of the work at Eagle as this is what Paul told me.  All the largest thrusts were from the switching transients.  Since M-E theory predicts this, Woodward filed for a patent on a pulsed AC power system.  I don;t know if in his patent he reverses the off transient or extinguishes it, but the two generate pulses in opposite directions (again, according to theory) so he must have dealt with it somehow.

It appears that there is miscommunication between you and Paul then.  See for example the attached responses.  They do not show an impulse spike (as in the Serrano Field Effect Boeing/DARPA device) but a rectangular pulse instead.

The Serrano Field Effect Boeing/DARPA device tested at Eagleworks is the one that only showed transient impulse response.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 03:12 pm
It is incorrect to state that classical physics thermal effects "violate broadly accepted physical principles such as conservation and Einstein's Equivalence Principle and General Relativity".  Thermal effects don't violate any such laws and/or principles.

On the contrary, the thermal effect explanation "appeals" because of Occam's razor:  the researchers should spend much more time analyzing classical physics explanations rather than exotic physics that are not generally accepted in the scientific community.

I think we can agree here, but it is important to note that the researchers at Eagle said they had ruled out thermal because of the promptness of the signal.  Now you've done some analysis that says one should not rule out thermal, and it would be good to see what they say.  I was however, responding to another poster here, who was speaking only of explanations for real thrust, not explanations of spurious sources.

You're convinced this is all hogwash, so you're arguing for thermal and this is what always happens with the skeptics.  No problem there.  We need skeptics.  The above was speaking only of actual thrust explanations so he is not a skeptic.  He's hopeful, an optimist you might say.  Regardless, the proof is really in the thrusts.  Sustained operation at sizable thrust would certainly put everyone's concerns about thermal to rest, as would some vacuum.  Normally results that are not generated in vacuum are not even considered as real results. In fact Sonny himself chided Paul for his MLT thruster results back in 2003, since Paul was unable to get the vacuum running properly.  It is therefore striking that not only did Sonny later abscond with those results and claim they were evidence for his QVF model, but he has now released a whole paper (albeit conference paper) full of results without that same control.  Remarkable, really.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 03:18 pm
It appears that there is miscommunication between you and Paul then.  See for example the attached responses.  They do not show an impulse spike (as in the Serrano Field Effect Boeing/DARPA device) but a rectangular pulse instead.

The Serrano Field Effect Boeing/DARPA device tested at Eagleworks is the one that only showed transient impulse response.
Guess I need to stop trusting my memory.  This fig 19 is interesting but where is the power spectrum?  How can you make sense of a graph with no power index?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 03:24 pm
Dr. Rodal, I have sent you 4 pieces of mail the most recent of which was today, none of which you responded to.  I can't even find them in my sent mail.  Did you get mail from me today or in the last month?
Title: Re: EM Drive Developments
Post by: aceshigh on 11/14/2014 03:53 pm
A careful reading of your line of questioning reveals to me some inaccuracy in your approach.

You ask, "bcause they don´t KNOW how to do it or because of budget constraints".  Budget is not the cause for lack of results.  If they do know how to do it  (not that "do it") they have not so demonstrated the phenomena.

if I was making a question, there was no inaccuracy in my line of approach. That's why it was a question. You just answered my question there, thus I don´t understand why you think there was an inaccuracy in my question. If there was innacuracy in a QUESTION you wouldn´t know how to answer it (but you did)


Quote
The potential economic stakes are very high, but the theoretical costs, if you will, are also very high.

that's what I was wanting to know.
Title: Re: EM Drive Developments
Post by: aero on 11/14/2014 04:32 pm
Later, if the EM Drive is demonstrated to produce thrust, then what kind of test could be done to detect the source of the momentum, the reaction mass? With a chemical rocket you can see the reaction mass, fire, and similarly for an ion thruster. Would a "Cloud chamber" allow visualization of the EM thruster reaction mass?

Knowing the character of the reaction mass would go a long way toward developing the correct theory of operation.
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 04:51 pm
Later, if the EM Drive is demonstrated to produce thrust, then what kind of test could be done to detect the source of the momentum, the reaction mass? With a chemical rocket you can see the reaction mass, fire, and similarly for an ion thruster. Would a "Cloud chamber" allow visualization of the EM thruster reaction mass?

Knowing the character of the reaction mass would go a long way toward developing the correct theory of operation.
That's why Dr. White proposed (in his August 2014 NASA Ames lecture) to measure "the wake in the Quantum Vacuum" left by the EM Drive as one of his future experimental steps. 

Recall that Dr. White proposes that the EM Drive is like a submarine using a propeller to push against the Quantum Vacuum (that acts according to Dr. White as the surrounding water in a submarine's propeller).

(http://www.popsci.com/files/imagecache/article_image_large/articles/submarineinspace_0.jpg)

Dr. White said at the conference he had discussions with other scientists at Ames, probably the idea to use "another EM Drive behind the thrusting EM Drive to measure the wake left in the Quantum Vacuum" came as a result of those discussions.

____
PS: I think that the idea that the EM Drive is using Quantum Vacuum electron-positron virtual-particles proposed by Dr. White and that the EM Drive is like a submarine propeller is non-viable and negated by the measured response that shows time constants exceeding by several orders of magnitude the electromagnetic and particle physics wave periods.  Also virtual particles are called virtual for good reason and there is nothing in the EM Drives with enough energy to make them real to be used as water is used by a submarine to propel itself.   (   http://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/   )
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 05:45 pm
One really wants to find a separate test for each of the proposed models, just as one looks for a separate test for each of the possible spurious sources.  For QVF, the fact that these thrusters do not function with DC applied seems to me ample falsification of the QVF model.  I have not seen any sort of response to this challenge and it's been years since the first challenges to QVF came in from lack of DC instigated thrust.

To check for M-E as the source, one wants to use a laser dopper vibrometer of sufficient frequency such as the Polytech UHF120:

http://www.polytec.com/us/products/vibration-sensors/microscope-based-systems/uhf-120-ultra-high-frequency-vibrometer/

If the source of thrust is M-E, then we should find 2 separate and distinct acoustic vibrations, one the second harmonic of the other.  Note that twice the drive frequency (what would be produced through electrostriction) of the E-M thruster is above the frequency of the above device, and it is probably cheaper to drive a new resonator at lower frequency than try to build your own microwave vibrometer, though the Materials Physics Lab in Helsinki has one that operates up to 40 Ghz, and I believe MIT has a very fast one good for microwave application as well.  The main trouble with this method for the E-M thruster is peering inside the truncated cone while it's operating.  I think you'd have to put in some sort of window but not sure how that would work.  Honestly, it might be easier to just test a real M-E design rather than something producing thrust by accident, which is what the Shawyer device may be doing.
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 06:28 pm
One really wants to find a separate test for each of the proposed models, just as one looks for a separate test for each of the possible spurious sources.  For QVF, the fact that these thrusters do not function with DC applied seems to me ample falsification of the QVF model.  I have not seen any sort of response to this challenge and it's been years since the first challenges to QVF came in from lack of DC instigated thrust.

To check for M-E as the source, one wants to use a laser dopper vibrometer of sufficient frequency such as the Polytech UHF120:

http://www.polytec.com/us/products/vibration-sensors/microscope-based-systems/uhf-120-ultra-high-frequency-vibrometer/

If the source of thrust is M-E, then we should find 2 separate and distinct acoustic vibrations, one the second harmonic of the other.  Note that twice the drive frequency (what would be produced through electrostriction) of the E-M thruster is above the frequency of the above device, and it is probably cheaper to drive a new resonator at lower frequency than try to build your own microwave vibrometer, though the Materials Physics Lab in Helsinki has one that operates up to 40 Ghz, and I believe MIT has a very fast one good for microwave application as well.  The main trouble with this method for the E-M thruster is peering inside the truncated cone while it's operating.  I think you'd have to put in some sort of window but not sure how that would work.  Honestly, it might be easier to just test a real M-E design rather than something producing thrust by accident, which is what the Shawyer device may be doing.

Dr. White predicted (in his papers) a thrust force (from the Quantum Vacuum) acting perpendicular to both the Electric (E) and Magnetic (B) fields.  However, the measured thrust force in the Eagleworks tests is perpendicular to Dr. White's prediction: in the TE mode the measured force is parallel to the magnetic (B) axial field and in the TM mode the measured force is parallel to the electric (E) axial field.  In both resonant mode cases (TE and TM) the measured force occurs in the axial direction of the truncated cone and of the Cannae device.

Ron, don't you see a problem with  Paul March's and Dr. White's methodology in that their measured response always occurs in the axial direction of both the Cannae and truncated cone, regardless of mode (TE and TM) and that in all cases this measured force is perpendicular to Dr. White's prediction? .  The fact that Brady, March, White, et.al do not point out this huge discrepancy is very disturbing. Measuring a force response that is perpendicular to their theoretical prediction should be enough of a test to disqualify their theories.

___
PS: Note that Dr. White mentions Dr. Woodward's "similar physical construct" to back up his prediction that the force should be perpendicular to both the electric and magnetic fields, but this prediction is negated by the experimental results that show the measured (Cannae and Truncated Cone) force to be perpendicular to their predictions.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 07:21 pm
Ron, don't you see a problem with  Paul March's and Dr. White's methodology in that their measured response always occurs in the axial direction of both the Cannae and truncated cone, regardless of mode (TE and TM) and that in all cases this measured force is perpendicular to Dr. White's prediction?

Yes, it's a very serious problem.  Is the fact the thrust is in the wrong direction any more a problem than there is no thrust with DC?  Obviously the model is broken.  On getting the angle wrong. . .I dunno what to think.  The ARC Lite was constructed so that the thruster can be easily reoriented on the end of the balance arm, to do certain kinds of tests.  The thruster itself is really the best dummy load one can hope for, if it is pointed vertically, and both Sonny and Paul are completely familiar with this protocol and were when they designed the Eagle balance, which is based on the ARC Lite.  Obviously, this requires one know what direction the thrust ought to be in.  How they could have gotten the thrust direction incorrect is beyond me.  I have never focused much on the Shawyer resonator, but I did ask Paul about this back in 2007, as I noted the thrust was parallel with the e-field rather than orthogonal/radial.  I never got an answer back then either.  And this is why I say, that QVF is pathological science--it does not matter to those involved how wrong they are.  They just continue on anyway.  No screw up, no data, no embarrassment is enough to dissuade them.  Same with ZPF theory.   Is it 20 years now since Haisch, Rueda and Puttoff published their landmark ZPF paper in Physical Review?  In all that time, no one has ever explained what to do about the obvious violations of EEP, conservation and that it gives the wrong mass for the proton by many orders of magnitude.  It is a BROKEN theory, yet it is the thing most in the advanced propulsion field cling to.  And I hate to say this but what the heck--I'm on a roll.  The REASON these crappy theories survive is they were created by people who have the right credentials.  This is a failure of the peer system.

I should probably read the paper again to be more familiar but as I'm not a believer, it's hard to muster up the energy.  It still annoys when I see pics like what you have posted up of the MLT, a decade after it was tested then renamed the QPT by Sonny to gather funding for his lab.  Sonny was the one who complained for years that Paul's test series was invalid because he never provided vacuum.  So how is it Sonny a decade later, renames that same device and pretends he had tested it at Eagle, when the tests were done in Paul's extra bedroom a decade before?  This kind of shenanigans just boils my blood. 

BTW, the thrust from the MLT design was orthogonal to the e and b fields--axial--and was recorded on the ARC Lite but it was a very small thrust.  Just 5uN or so.  I built the 12 item test series that put the end to the MLT program, as it enabled Jim to see what was wrong with that design.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/14/2014 07:39 pm
Found another theory on how EMdrives might work.

http://arxiv.org/abs/1302.5690

Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/14/2014 07:43 pm
Well...
What is one to make of all this?
Does anyone know about the status/existence of ongoing experiments?
Homebrew setups seem perhaps able with the knowledge on this thread to be able to answer lots of questions. However I do not have a garage.
Anyone with an idea what the next step will be?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/14/2014 07:44 pm
A very scathing rebuttal of EMdrives...

http://johncostella.webs.com/shawyerfraud.pdf
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/14/2014 07:46 pm
Found another theory on how EMdrives might work.

http://arxiv.org/abs/1302.5690
Dr Rodal, Frobnicat...
If you can make sense of this well done!
I'm afraid it's above me...
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 07:47 pm
Found another theory on how EMdrives might work.

http://arxiv.org/abs/1302.5690
Dr Rodal, Frobnicat...
If you can make sense of this well done!
I'm afraid it's above me...



We discussed this paper earlier in this thread.  This Argentinean's (compatriot of Brito, Marini and Galian) coupling theory is negated by the unphysical, non-existent, effects predicted, as the author himself admits:

Quote
The weakest part of the theory seems to be that there is no clear way of preventing large gravitational effects due to the magnetic field of the Earth,

The nonlinear "fix" the author speculates with (and does not mathematically pursue) at the end of his paper is unlikely to work as such "nonlinear" messing up with General Relativity invariable ends up messing up Relativity's successful predictions and contradicting astrophysical results.

______________

PS: Note that the author writes:

Quote
Such claims were criticized by the scientific community mainly due to the proposed theoretical explanation, as Maxwell equations and Special Relativity clearly indicate that no force is possible without the emission of radiation from the cavity.

Recall that Dr. McCulloch's proposal satisfies this condition: McCulloch force is produced by Unruh radiation.
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 08:08 pm
This (Fernando O. Minotti) statement bears repeating:

the scientific community (universallly-accepted physics) ... Maxwell equations and Special Relativity clearly indicate that no (electromagnetic drive) force is possible without the emission of radiation from the cavity.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/14/2014 08:16 pm
I went back to the Egan analysis and I note that for the heat locations he came up with for TE in particular, the direction of thrust would be opposite the measured thrust, if the measured thrust were due to radiation or convection. The signs are reversed. The sloping walls are hotter than the end plates.

http://www.gregegan.net/SCIENCE/Cavity/Cavity.html
What do you think?

I didn't go looking for this. I was there looking at radiation pressure plots for use with the "transfer of momentum from the QV to dielectrics" (QV sail) approach I'm championing (as opposed to White's thrusting against something that isn't there to push on or otherwise manipulate, or trying to make virtual particles "real"), and I needed to see if Shawyer's assertions of uneven radiation pressure inside the cavity held water or not. Because if Shawyer's asymmetric radiation pressure postulate is true, this boils down to simple(not so) momentum vector addition.

Title: Re: EM Drive Developments
Post by: Mulletron on 11/14/2014 08:18 pm
This (Fernando O. Minotti) statement bears repeating:

the scientific community (universallly-accepted physics) ... Maxwell equations and Special Relativity clearly indicate that no (electromagnetic drive) force is possible without the emission of radiation from the cavity.

I'm not championing Minotti's paper, just posting it. I'm full QV and thermal all the way baby! Those are the only ways I know of to conserve momentum.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/14/2014 08:23 pm
QV does not conserve momentum.  This is why, in the paper, Sonny specifically calls this a violation of conservation.  M-E conserves momentum.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/14/2014 08:26 pm
It does the way I'm approaching it.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/14/2014 08:38 pm
Well...
What is one to make of all this?
Does anyone know about the status/existence of ongoing experiments?
Homebrew setups seem perhaps able with the knowledge on this thread to be able to answer lots of questions. However I do not have a garage.
Anyone with an idea what the next step will be?
Thank you for answering about http://arxiv.org/abs/1302.5690
How about my broader question?
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 09:09 pm
Well...
What is one to make of all this?
Does anyone know about the status/existence of ongoing experiments?
Homebrew setups seem perhaps able with the knowledge on this thread to be able to answer lots of questions. However I do not have a garage.
Anyone with an idea what the next step will be?
Thank you for answering about http://arxiv.org/abs/1302.5690
How about my broader question?
This is what I recall:

1) The "Anomalous..." paper ends with "The current plan is to support an IV&V test campaign at the (NASA) Glenn Research Center (GRC) using their low thrust torsion pendulum followed by a repeat campaign at the Jet Propulsion Laboratory (JPL) using their low thrust torsion pendulum. The Johns Hopkins University Applied Physics Laboratory has also expressed an interest in performing a Cavendish Balance style test with the IV&V shipset."

2) At the NASA Ames August conference Dr. White states that one of his future steps is to measure the quantum vacuum wake left by the EM Drive by positioning another EM Drive behind it to measure the wake. 

3) Dr. White also stated that he is planning to conduct measurements with the truncated cone pointing up and also pointing down, to verify that the measured force is null under those orientations.

4) Dr. White also stated that he is planning to conduct tests in a vacuum.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/14/2014 09:11 pm
Awesome Dr Rodal... Just what I asked, thank you.
Now,
Is this enough? Results when? Still DIY job could provide data....
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 09:15 pm
I went back to the Egan analysis and I note that for the heat locations he came up with for TE in particular, the direction of thrust would be opposite the measured thrust, if the measured thrust were due to radiation or convection. The signs are reversed. The sloping walls are hotter than the end plates.

http://www.gregegan.net/SCIENCE/Cavity/Cavity.html
What do you think?
...


1) Greg Egan does not show (in his plots) the Axial Magnetic field for the TE (transverse electric) modes.  Did he compute it?  Why doesn't he show it? 

(http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/TE2.gif)


Eagleworks computed the axial magnetic field and does show it (see attached picture below)

2) Consistent with #1 above, Greg Egan does not discuss the axial magnetic field heating of the ends (by eddy currents produced by the changing alternating magnetic field), in his discussion of the transverse electric mode heating.  Greg Egan wrote " for the TM modes we need to subtract the tension on the walls due to the Coulomb force acting on the charge distribution induced by the electric field meeting the walls" but for the TE modes Egan does not seem to have similarly taken into account eddy-current heating of the ends produced by the axial magnetic field perpendicular to the ends.

3) Consistent with #1 and #2 above Greg Egan shows the heated areas in TE and TM modes by the TRANSVERSE fields, but shows no heating from the axial field.

(http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/TEheat2.gif)

This seems wrong to me.  I expect much more significant heating from eddy currents produced by the axial magnetic field (not taken into account by Egan) than heating of the cone's round wall by the electric field which never contacts the round walls (Egan admits this, so he computes the heating as a result of the energy density instead).  This seems a wrong way to compute the heat.

4) Greg Egan considered hemispherical ends instead of the flat ends that the actual EM Drive truncated cone and the Shayer demonstrator. experimental and flight demos have.  Greg Egan does not discuss the difference caused by this assumption except that he adopted this assumption in order to obtain a closed-form solution.


Electric Field (red)

Magnetic Field (blue)

COMSOL FE solutions by Eagleworks for TE mode of truncated cone
Title: Re: EM Drive Developments
Post by: Mulletron on 11/14/2014 09:30 pm
Please bear with me here, but here's an idea I had to test this at home, coupled with the simple torsion balance I linked to recently.

So I need a copper cavity. Those aren't easy to come by and I'm too lazy to buy copper sheet to build my own and I'd probably build it like crap anyway. But I remembered that I can get my hands on a little brass bell just about anywhere. Look in your Christmas decorations. Once a suitable bell is found, it is a straight forward exercise to drill a hole in it to mount an rf connector, fabricate a suitable loop probe and solder it into the rf connector cup, glue some dielectric material in it, and then cut out a copper sheet and solder the thing shut. A quick and dirty resonant cavity on the cheap.

Now you're going to have to find a signal generator. I guess you can rent one. I have piles of them where I work so no issues there. HP 83712B and 83752B sig gens are very very stable. They go up to 20ghz. If I remember right, you can get +20dbm out of them. I never tried pushing them that high. Never more than 0dbm for me.

Next by some homebrew miracle, find a resonant frequency close to what you calculated and try not to reflect all your power back into the sig gen.

The only right way is to use a directional coupler with power detectors or a network analyzer to measure fwd/reflected power.

If you can't get a sig gen. I know you can hack old Linksys WAP11 access points into CW mode @ around 2.4ghz.

Necessity is the mother of invention.

As far as a dielectric, look in your toolbox. You probably have PTFE tape in there.

You'd have to be pretty creative to sort out cable strain on your setup and you have to put the mess in the basement and isolate it from wind currents/people/pets, whatever. Not easy. I might do it. I'm still thinking about whether is is worth it or not personally to go through the trouble.
Title: Re: EM Drive Developments
Post by: Rodal on 11/14/2014 09:33 pm
Please bear with me here, but here's an idea I had to test this at home, coupled with the simple torsion balance I linked to recently.

So I need a copper cavity. Those aren't easy to come by and I'm too lazy to buy copper sheet to build my own and I'd probably build it like crap anyway. But I remembered that I can get my hands on a little brass bell just about anywhere. Look in your Christmas decorations. Once a suitable bell is found, it is a straight forward exercise to drill a hole in it to mount an rf connector, fabricate a suitable loop probe and solder it into the rf connector cup, glue some dielectric material in it, and then cut out a copper sheet and solder the thing shut. A quick and dirty resonant cavity on the cheap.

Now you're going to have to find a signal generator. I guess you can rent one. I have piles of them where I work so no issues there. HP 83712B and 83752B sig gens are very very stable. They go up to 20ghz. If I remember right, you can get +20dbm out of them. I never tried pushing them that high. Never more than 0dbm for me.

Next by some homebrew miracle, find a resonant frequency close to what you calculated and try not to reflect all your power back into the sig gen.

The only right way is to use a directional coupler with power detectors or a network analyzer to measure fwd/reflected power.

If you can't get a sig gen. I know you can hack old Linksys WAP11 access points into CW mode @ around 2.4ghz.

Necessity is the mother of invention.

As far as a dielectric, look in your toolbox. You probably have PTFE tape in there.

You'd have to be pretty creative to sort out cable strain on your setup and you have to put the mess in the basement and isolate it from wind currents/people/pets, whatever. Not easy. I might do it. I'm still thinking about whether is is worth it or not personally to go through the trouble.

Please be very careful and safe if you are going to perform this experiment at home as we always appreciate your contributions and would be very upset if something happens to you !
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/14/2014 09:34 pm
Please be careful, but hey, go for it!
You could change the Universe!
Title: Re: EM Drive Developments
Post by: Mulletron on 11/14/2014 09:46 pm
Less than 1 watt won't hurt anybody.
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/15/2014 12:18 am
Ok...

Ron...

In my most recent summary of the approaches taken on this thread to investigate EM Drive, I briefly described four approaches as to why we thought at one time or another it might work, and one explanation as to why it does not.  I was not putting forth the 'thermal artifact' explanation as a valid drive, but as a possibly valid explanation as to why the device does not work, yet might give the appearance of doing so.

Mulletron-

For your cavity, head to the plumbing section of the local hardware store, if such a place is to be found in your area.  There are angled copper couplings and caps which should come fairly close to your requirements.   But be very careful!

John, add proper cautionary video/image for Mulletron...
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/15/2014 12:37 am
John, add proper cautionary video/image for Mulletron...

[Raises finger.]  [Not that finger.  The index finger.]

Izzit because I'm that predictable, or izzit because the material is that predictable?  It's almost tooooo eeezy...

http://www.youtube.com/watch?v=fAWJdXJvngU
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/15/2014 03:14 pm
Please bear with me here, but here's an idea I had to test this at home, coupled with the simple torsion balance I linked to recently.

So I need a copper cavity. Those aren't easy to come by and I'm too lazy to buy copper sheet to build my own and I'd probably build it like crap anyway. But I remembered that I can get my hands on a little brass bell just about anywhere. Look in your Christmas decorations. Once a suitable bell is found, it is a straight forward exercise to drill a hole in it to mount an rf connector, fabricate a suitable loop probe and solder it into the rf connector cup, glue some dielectric material in it, and then cut out a copper sheet and solder the thing shut. A quick and dirty resonant cavity on the cheap.

Now you're going to have to find a signal generator. I guess you can rent one. I have piles of them where I work so no issues there. HP 83712B and 83752B sig gens are very very stable. They go up to 20ghz. If I remember right, you can get +20dbm out of them. I never tried pushing them that high. Never more than 0dbm for me.

Next by some homebrew miracle, find a resonant frequency close to what you calculated and try not to reflect all your power back into the sig gen.

The only right way is to use a directional coupler with power detectors or a network analyzer to measure fwd/reflected power.

If you can't get a sig gen. I know you can hack old Linksys WAP11 access points into CW mode @ around 2.4ghz.

Necessity is the mother of invention.

As far as a dielectric, look in your toolbox. You probably have PTFE tape in there.

You'd have to be pretty creative to sort out cable strain on your setup and you have to put the mess in the basement and isolate it from wind currents/people/pets, whatever. Not easy. I might do it. I'm still thinking about whether is is worth it or not personally to go through the trouble.

I am not a fan of DIY propulsion experiments since it's very difficult to provide the instrumentation necessary to learn anything, and most replications for value cost between $1-2 million, though most of this is labor costs.  However, I'll be as supportive as possible.  Just please do as Dr. Rodal suggests and avoid frying yourself.  Have you worked with microwave before?

I think before you decide to build anything, you want to have a long talk with Paul March so you can avoid some of the pitfalls.  For example, I think copper is not the best choice because it will vaporize and arc.  Stainless steel is supposed to be better.  You might modify a steal cone as found here:

http://www.globalindustrial.com/p/material-handling/drum-barrel/drum-covers/drum-cone-t304-stainless-steel-60-degree-size-23-fits-23-3-8-od-rim

Can you do precision brazing?

If you have a 20Ghz signal generator and power generator, then you're looking at a very small resonator--about 1/10 the size of that at Eagle.  It is possible you could fit something like this on a Mettler H20.  I believe the H20 has a max load of 260g and resolution of 0.05mg, but I am terrible with numbers so do look the specs up if you are interested.  If the Mettler will work, I have an H20 I can have sent to you.  It's in a lab in PA and I'm not so we are at the mercy of the lab here, but should be no trouble.

Note that the Mettler is mostly metal, and you will have serious coupling issues.  So you will need a Mu Metal shield to wave around at the least, and a full magnetic shield would be better.  Note that Mu Metal is highly anisotropic and needs special annealing done at the factory in order to form a real shield.  You should not plan to anneal it yourself after forming.  So waving around a simple sheet of foil to test for coupling is a better, prior choice and wait to spend cash on a real shield if you can.

Not sure you can use a signal generator and power generator.  The cavity has a Q of something like 2,500?  so one expects it has a great deal of reflected power.  In any case, the reason Eagle used a continuous wave magnetron over a simple microwave oven magnetron, was normal vacuum tubes cannot stand the strain of a standing wave.  That might be true of your power amp as well.

Generally in these kinds of explorations, labor is the most expensive cost, so DIY means you stand to save a lot (but you get what you pay for).  Next is the cost of the instrumentation, primarily balance and vacuum, but also some very expensive scopes and such to look at what the power system is providing. Paul mentioned one particular instrument he found as ideal and extremely cost effective so you should scour the Eagle paper for mention of this, and write Paul if you don't find it.  Third in cost is the power system.  You will need a PLL circuit.  Eagle remarked several times what a huge step forward it was to provide resonance matching.  I've been trying to provide the same power circuitry to Woodard for years but even though PLL circuits are relatively easy for an EE to design and build, microwave circuits are not.  They are considered "black magic" and very difficult to engineer in the microwave region because of all the stray capacitances, etc.  So do indeed consider the power system a serious challenge no matter what choices you make.  Finally comes the thruster which is generally the simplest, cheapest part of these systems.  Don't be deceived about the complexity of the task by the simplicity of the thruster.

I designed an M-E replication lab a year ago so I have an idea of the challenge here.  It is between $1-2 million to do this as cheaply as possible with professional resources.  I would not want to try it on a hobbyist budget.
Title: Re: EM Drive Developments
Post by: DIYFAN on 11/15/2014 04:56 pm
So I need a copper cavity. Those aren't easy to come by and I'm too lazy to buy copper sheet to build my own and I'd probably build it like crap anyway. But I remembered that I can get my hands on a little brass bell just about anywhere. Look in your Christmas decorations. Once a suitable bell is found, it is a straight forward exercise to drill a hole in it to mount an rf connector, fabricate a suitable loop probe and solder it into the rf connector cup, glue some dielectric material in it, and then cut out a copper sheet and solder the thing shut. A quick and dirty resonant cavity on the cheap.

For the cavity itself, metal 3d printing is now ubiquitous and affordable.

http://gpiprototype.com/services/metal-3d-printing.html (http://gpiprototype.com/services/metal-3d-printing.html)

https://www.solidconcepts.com/technologies/direct-metal-laser-sintering-dmls/?gclid=CMCy2rWzmMECFQqCfgod3A4AXw (https://www.solidconcepts.com/technologies/direct-metal-laser-sintering-dmls/?gclid=CMCy2rWzmMECFQqCfgod3A4AXw)

(and many others)

A simple CAD design and a submission to a 3d printing company can yield a well-formed prototype cavity within 1-2 weeks. The prototype can be formed of a variety of metals. The prototype could be tested in a non-superconducting configuration first to get a baseline. Then, the inner portion of the cavity could be lined with YBCO film, cooled to liquid nitrogen temperatures, and tested in a superconducting configuration.

It even appears that some universities have access to 3d printers that are capable of printing using superconducting materials.  Perhaps this would make a good senior project or thesis for an ambitious student.  I always wished I'd taken more advantage of my university's resources when I had the chance.
http://www.tamuk.edu/engineering/departments/mien/3D%20Printers/index.html (http://www.tamuk.edu/engineering/departments/mien/3D%20Printers/index.html)
Title: Re: EM Drive Developments
Post by: Mulletron on 11/15/2014 06:25 pm
Quote
Have you worked with microwave before?
Lol yes. I know what I'm doing. Radars and satcom are what I do. The biggest issue here is trying to couple rf from a 40 pound sweep generator to the test article because of the cable strain. Rf cables are heavy and rigid and using them would screw everything up. If I can't figure this out, I'm not doing it. I'd rather have a small rf generator balanced right there on the thing, running on batteries, but I'm not spending money buying one. I want to use an actual sweep generator so I can tune it and provide an rf sweep. But the cable issue is daunting. I'm thinking of using an xbee pro or putting an old wifi access point in CW mode. I have those. The best I can get in any case is +20dbm, so the test article needs to be small and light. The low powers involved would mean keeping the thing running for hours or days to see if any rotation happens.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/15/2014 06:40 pm
The solution for the trouble you note used on the ARC Lite is to use liquid metal (Galinstan) contact pots, where the pot is stationary and a small cylindrical cross section probe rotates inside the liquid.  The pots are arranged directly above the C-flex bearings so there is no displacement at all of the probe inside the Galinstan.  This is what gives the ARC Lite such fantastical resolution as compared to all the previous torsion balances, such as the one at the Austrian Research Center.

As to this notion of a superconducting resonator, I would just note that in order to line the chamber with YBCO, at the least the outside of the resonator would need to be immersed in liquid nitrogen and linked to a dewar.  This is a total nightmare for the balance and contrary to the opine over at Reddit, there is no way to do something like this for $2k.  I doubt it can be done for $2M.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/15/2014 06:53 pm
The solution for the trouble you note used on the ARC Lite is to use liquid metal (Galinstan) contact pots, where the pot is stationary and a small cylindrical cross section probe rotates inside the liquid.  The pots are arranged directly above the C-flex bearings so there is no displacement at all of the probe inside the Galinstan.  This is what gives the ARC Lite such fantastical resolution as compared to all the previous torsion balances, such as the one at the Austrian Research Center.

As to this notion of a superconducting resonator, I would just note that in order to line the chamber with YBCO, at the least the outside of the resonator would need to be immersed in liquid nitrogen and linked to a dewar.  This is a total nightmare for the balance and contrary to the opine over at Reddit, there is no way to do something like this for $2k.  I doubt it can be done for $2M.

I was thinking about liquid metal all day but couldn't remember what it was called. I know that's what Eagleworks used. I don't want to mess with mercury so thanks for the tip on the Galinstan. I think, with some bench time, I could build a f-f TNC or SMA bridge.

This setup needs to be only a few ounces at most and completely balance from low test fishing line or thread to even have a chance of not being a waste of time. So I have to solve the rf cable problem first.
Title: Re: EM Drive Developments
Post by: Star One on 11/15/2014 07:01 pm
Shouldn't we be hearing more from EagleWorks sooner rather than later, weren't they supposed to be doing more tests by now?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/15/2014 07:07 pm
I'm sure they do tests nearly every day, but they don't release results without reason--such as fundraising.

Mullet, I suggest make provision for more than the necessary 2 pots as Woodward later added separate power channels for other reasons.  If for instance you put an M-E Thruster on there and want to put DC Bias on parts of the stack and not on other parts, you need separate channels for this.  Just make the brace taller than you need.  And I do recommend acrylic with urethane sheeting strategically placed to remove any stray resonances.  Dr. Rodel's stray resonance modeling was impressive, but putting the sheeting in is wise for many reasons.

What do you intend to isolate the balance from seismic?  Putting the whole thing on a platform sitting atop an inner tube is a cheap trick that seems to work well.
Title: Re: EM Drive Developments
Post by: DIYFAN on 11/15/2014 07:08 pm
. . . there is no way to do something like this for $2k.  I doubt it can be done for $2M.

With all due respect, I suggest it is the DIY vs. the Institutional mindset.  I remember my high school teacher using liquid nitrogen in the classroom near students to freeze and smash banana peels into bits.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/15/2014 07:19 pm
I remember that too.  The issue is that this stuff needs to rotate freely on the balance arm.  Just as Mullet is looking at how to feed power through the balance fulcrum without causing resistance that would show up as a spurious source, you would need to feed liquid nitrogen through and that is far more problematic.  It's a serious problem.  You'd likely need to place the entire cryo system on the mobile portion of the balance and then you'd have a huge period to cope with, and nitrogen boil off to account for.  It opens a whole new can of nasty worms.  The coolant cycling through the system would generate far larger forces than the thruster, and even though they ought to cancel, that cancelation might be time dependent based on how the coolant cycles.  So you could entirely swamp the system with spurious sources you can't get rid of.  It's a terrible solution for a tiny budget.
Title: Re: EM Drive Developments
Post by: DIYFAN on 11/15/2014 07:24 pm
I remember that too.  The issue is that this stuff needs to rotate freely on the balance arm.  Just as Mullet is looking at how to feed power through the balance fulcrum without causing resistance that would show up as a spurious source, you would need to feed liquid nitrogen through and that is far more problematic.  It's a serious problem.  You'd likely need to place the entire cryo system on the mobile portion of the balance and then you'd have a huge period to cope with, and nitrogen boil off to account for.  It opens a whole new can of nasty worms.  The coolant cycling through the system would generate far larger forces than the thruster, and even though they ought to cancel, that cancelation might be time dependent based on how the coolant cycles.  So you could entirely swamp the system with spurious sources you can't get rid of.  It's a terrible solution for a tiny budget.


If a resonant frequency can be found with a small superconducting test article, it won't be a matter of detecting tiny force measurements on a delicate balance.  If Shawyer type predicted forces bear out, then it would be more a matter of making sure the test article doesn't take off.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/15/2014 07:57 pm
Okay.  Lets say you want to test for those magnitude of forces.  Are you suggesting an experimental apparatus that can only detect very large forces?  Say you put it on something like a bathroom scale.  If you get no reading, what do you do then?  Do you then build a proper balance or do you count this as a null result?

Surely it is cheaper to use a bathroom scale but there are reasons science seldom does this sort of thing.  If one is to learn even from null results, one needs more precision than is cheap and easy, and most times science learns more from its mistakes than its successes.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/15/2014 08:08 pm
Can anyone here tell me why I can't find all but one of my outgoing mail?  I've been told it is going out, but I can't see any of it, and I don't see a box to check to save outgoing mail or anything like this.  Can't figure out what sort of bone-head mistake I'm making here. . .
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/15/2014 08:12 pm
If a resonant frequency can be found with a small superconducting test article, it won't be a matter of detecting tiny force measurements on a delicate balance.  If Shawyer type predicted forces bear out, then it would be more a matter of making sure the test article doesn't take off.
I should note too, that YBCO's superconductivity is highly frequency dependent.  I don't think it works past low VHF. Certainly not microwave.
Title: Re: EM Drive Developments
Post by: DIYFAN on 11/15/2014 08:21 pm
If a resonant frequency can be found with a small superconducting test article, it won't be a matter of detecting tiny force measurements on a delicate balance.  If Shawyer type predicted forces bear out, then it would be more a matter of making sure the test article doesn't take off.
I should note too, that YBCO's superconductivity is highly frequency dependent.  I don't think it works past low VHF. Certainly not microwave.

Shawyer discloses using YBCO film both in his patent application and in reported prototype testing, with positive results. 

There is no doubt in my mind that high-precision testing in suitable scientific labs is of paramount importance in exploring this astonishing effect. 

There is also no doubt in my mind that, if proven to work, the DIY community will eventually take this up on a tiny budget and expand the field at a pace that will make our heads spin.  Just look to the DIY drone community and what they accomplished in so short a period of time.  I would submit that if it were not for such a community, you would not see the high caliber of commercial drones that you now see in the marketplace.  Don't underestimate the diligent tinkerer with a shop in the back yard, and time to spare. 

What is needed more than ever is additional confirmation of the effect.  Perhaps some solid data on a small superconducting test article.  Maybe it is the well-respected scientific labs that need to first produce such a test article and prove it is worth the time to investigate further.  Then, thanks to the Internet and tightly-knit communities that can quickly rally behind an idea, the sky becomes the limit . . . (or perhaps the moon, or mars, um, okay I'll stop).
Title: Re: EM Drive Developments
Post by: zen-in on 11/16/2014 03:01 am
So I need a copper cavity. Those aren't easy to come by and I'm too lazy to buy copper sheet to build my own and I'd probably build it like crap anyway. But I remembered that I can get my hands on a little brass bell just about anywhere. Look in your Christmas decorations. Once a suitable bell is found, it is a straight forward exercise to drill a hole in it to mount an rf connector, fabricate a suitable loop probe and solder it into the rf connector cup, glue some dielectric material in it, and then cut out a copper sheet and solder the thing shut. A quick and dirty resonant cavity on the cheap.

For the cavity itself, metal 3d printing is now ubiquitous and affordable.

http://gpiprototype.com/services/metal-3d-printing.html (http://gpiprototype.com/services/metal-3d-printing.html)

https://www.solidconcepts.com/technologies/direct-metal-laser-sintering-dmls/?gclid=CMCy2rWzmMECFQqCfgod3A4AXw (https://www.solidconcepts.com/technologies/direct-metal-laser-sintering-dmls/?gclid=CMCy2rWzmMECFQqCfgod3A4AXw)

(and many others)

A simple CAD design and a submission to a 3d printing company can yield a well-formed prototype cavity within 1-2 weeks. The prototype can be formed of a variety of metals. The prototype could be tested in a non-superconducting configuration first to get a baseline. Then, the inner portion of the cavity could be lined with YBCO film, cooled to liquid nitrogen temperatures, and tested in a superconducting configuration.

It even appears that some universities have access to 3d printers that are capable of printing using superconducting materials.  Perhaps this would make a good senior project or thesis for an ambitious student.  I always wished I'd taken more advantage of my university's resources when I had the chance.
http://www.tamuk.edu/engineering/departments/mien/3D%20Printers/index.html (http://www.tamuk.edu/engineering/departments/mien/3D%20Printers/index.html)

I would be interested in learning more about this 3-D printer for superconductors.   They are difficult to work with.   Low temperature superconducting resonant cavities have been machined from Niobium.   It would be very impractical to make one from pieces of high temperature superconductor because there is no way of connecting the pieces electrically so that everything together is superconductive.    Also HTS is anisotropic for the most part.    It is difficult to measure small forces on an article when lN2 is boiling off.   The escaping gas produces its own thrust.   Pure Silver or Copper have been used to produce high Q cavities.   Other alloys are too lossy.   One source for Copper is VHF cavities.   I have some with a Dia of 18" and 3' high made from 16 gauge.   They are VHF reject cavities.   It would be a simple matter for someone skilled in metal smithing to make a cone out of one.   
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/16/2014 01:13 pm
...it is the DIY vs. the Institutional mindset.  I remember my high school teacher using liquid nitrogen in the classroom near students to freeze and smash banana peels into bits.

I dunno what that faux respect is all about, since the other guy just said that a $2k budget is insufficient.  Intuitively, $2M is far too high a price to posit for conducting a DIY experiment.

I do share the happy memory of our physics teacher hammering frozen banannas in the actual classroom, and all of us actual students were dressed in actual street clothes.  Now you see, in educational promotional materials,  staged fotographs of "happy", "smiling" students with absolutely clear eye protection, gathered around a voltmeter, being safer that could be possibly imagined.  But anyhow....

... it would be more a matter of making sure the test article doesn't take off.

I'm sure you realize that this has not been the problem.
Title: Re: EM Drive Developments
Post by: Rodal on 11/16/2014 03:55 pm
I received the following message from Robert Ludwick answering Ron Stahl's comments:




From:   Robert Ludwick
Sent:   Friday, November 14, 2014 6:15 PM
To:   Dr. J. Rodal
Subject:   Testing the EmDrive

Hello Dr. Rodal,

This is in response to Ron Stahl's comments:

Quote from:  Ron Stahl
I think he’s right.  He doesn’t understand.  This is a very high Q resonator. The higher the Q, the narrower the bandwidth it can resonate at.  Without resonance the Q will drop off to between 1/100 and1/10,000 what it is normally.  The resonator needs to resonate.  You cannot simply sweep a resonator and think you are changing the frequency only, when the Q is only for small bandwidths of specific frequencies.

Of course the higher the Q the narrower the bandwidth.  Actually, Bandwidth=(resonant frequency)/Q  ,so if we are talking frequencies of 1-2 Ghz and Q’s of (using Ron’s numbers above) 10,000 it implies a bandwidth of 100-200 KHz, which is NOT particularly narrow.  Shawyer is talking superconducting thrusters with Q’s in the vicinity of 1e9.  That would imply bandwidths of 1-2 Hz at the frequencies of the thrusters tested to date.

The test procedure I provided ASSUMED that a network analyzer had been used to identify the resonant frequencies and bandwidths of interest PRIOR to the start of the actual thrust test, so that the operator would be able to select appropriate start and stop frequencies, guaranteeing that the testing starts and stops well outside the high Q region and steps at the appropriate increment to ensure that there will be multiple thrust tests across the actual bandwidth of highest Q.  The procedure ENSURES that the thruster is tested at the frequency of maximum Q, and thus, per theory, the frequency of maximum thrust.  If any.

Then Ron Stahl states this: 

Quote from:  Ron Stahl
Since Eagle has a PLL resonance matching circuit, there is little trouble with this except that you need to note you have not one but two variables as you have changed the amount of active mass.

First, please tell me that a lab set up to evaluate ‘Propellant-Less (exotic physics) Drives’ is NOT using a Mini-Circuits VCO, stabilized by a home brew Phase Locked Loop (PLL), as their lab signal source.

Concerning Ron's statement 

Quote from:  Ron Stahl
….you need to note that you have not one but two variables, as you have changed the amount of active mass.

If you identify the frequency of maximum Q, then step the signal generator frequency through the frequency of maximum Q, holding the amplifier power constant, making sure you start well below the frequency of peak Q and stop well above it, using frequency steps small enough to ensure that at least 10 (and in the case of Q’s as low as 10,000, as many as 100) test frequencies are within the resonant bandwidth,  and wait after each frequency step long enough for the mechanical system to stabilize before taking a thrust reading, how is that 'changing the active mass’ (using the definition of mass generally accepted in academia) ? If they are changing the internals of the thruster between tests, it would be necessary to put the thruster on the network analyzer after every ‘change of guts’ to identify the new resonant frequencies / bandwidths, but otherwise it would seem to me that the test as described would work just fine, and would only involve changing one factor:  test frequency.  Power and thus amplifier current would remain constant for the duration of the test.  The purpose of the test is to discover if thrust is generated under any conditions and whether the thrust is related to the thruster Q at the drive frequency. 

Then Ron Stahl states this: 
Quote from:  Ron Stahl
This is much more difficult and much more expensive than you understand.  Just the high speed auto matcher used up at George Hathaway’s lab cost $150k.  And make no mistake, it is the power equipment that one presumes should be easy enough to build that costs so much.  It was a big breakthrough for Eagle to get their PLL circuit in place and this is something that Woodward has never been able to do.

I have no idea what a ‘high speed auto matcher' is in this context, what function it performs, or why it is required to measure the thrust of an EmDrive. As for the PLL circuit is their need for something uniquely different from the standard use of PLL’s, which is to provide precisely controlled, stable outputs from an oscillator ?.  And the ‘power equipment that costs so much’??  Again, what I have seen on the forum refers to amplifiers in the 1-3 GHz range that output a few tens of watts.  THOSE are NOT expensive.  So what is the super expensive ‘power equipment’ that Ron is talking about?

My simple minded interpretation of the commentary leads me to believe that Eagleworks could use some decent test equipment, such as signal sources, network analyzers, power meters, power amplifiers etc. 

It is obvious from the over 200 pages of commentary on this subject I am not the only one excited about the claims about EM Drives.  These folks need to get off the dime and get this thing going (or prove conclusively that there ain’t no there there, so I can relax and forget it).

Bob Ludwick   
Title: Re: EM Drive Developments
Post by: Mulletron on 11/16/2014 05:04 pm
You've all seen this presentation before, more than likely:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf

I broke out two slides, which were pretty small in the presentation (had to zoom in a lot) about Shawyer's and Fetta's design and highlighted some neat information. One such thing is that it says Darpa got the Cannae through the door at Eagleworks. Indeed Fetta's design does look like a node from superconducting linear accelerator resonant cavities I've seen presented. See below.. The rest is circled in the slides.

Hightlights: The Cannae slide shows an actual photo of the dewar. Looks like it's in somebody's kitchen. It also states the cavity is asymmetric. The only asymmetry I see is the fact that one tube is longer than the other on the Cannae test article from Brady et al.

http://www.lepp.cornell.edu/~hoff/LECTURES/10USPAS/notes10.pdf
http://uspas.fnal.gov/materials/09UNM/Unit_4_Lecture_9_RF_Cavities.pdf
http://uspas.fnal.gov/materials/09UNM/ResonantCavities.pdf

Title: Re: EM Drive Developments
Post by: DIYFAN on 11/16/2014 05:30 pm
If a resonant frequency can be found with a small superconducting test article, it won't be a matter of detecting tiny force measurements on a delicate balance.  If Shawyer type predicted forces bear out, then it would be more a matter of making sure the test article doesn't take off.
I should note too, that YBCO's superconductivity is highly frequency dependent.  I don't think it works past low VHF. Certainly not microwave.

The conclusions of the authors of the attached IEEE paper entitled "Microwave Properties of YBCO Thin Films" seem to contradict your thoughts on YBCO's superconductivity not working past low VHF.  To the contrary, the authors conclude:

"All techniques are capable of producing high quality thin films with excellent microwave properties.  The patterned films exhibit low surface resistance values at 8GHz down to 25µΩ and 120µΩ at 13K and 77K, respectively which is comparable with the best reported values in the literature.   . . .   Furthermore, the results suggest that there is insignificant degradation of the microwave properties of the films due to patterning.  . . .   demonstrates the excellent power performance of these YBCO thin films which is essential for practical applications."
Title: Re: EM Drive Developments
Post by: Rodal on 11/16/2014 05:41 pm
Quote
Have you worked with microwave before?
Lol yes. I know what I'm doing. Radars and satcom are what I do. The biggest issue here is trying to couple rf from a 40 pound sweep generator to the test article because of the cable strain. Rf cables are heavy and rigid and using them would screw everything up. If I can't figure this out, I'm not doing it. I'd rather have a small rf generator balanced right there on the thing, running on batteries, but I'm not spending money buying one. I want to use an actual sweep generator so I can tune it and provide an rf sweep. But the cable issue is daunting. I'm thinking of using an xbee pro or putting an old wifi access point in CW mode. I have those. The best I can get in any case is +20dbm, so the test article needs to be small and light. The low powers involved would mean keeping the thing running for hours or days to see if any rotation happens.

Bob Ludwick sent me this response:




From:   Robert Ludwick
Sent:   Saturday, November 15, 2014 5:19 PM
To:   Dr. J. Rodal

In order to stop worrying about how to install a signal cable from the 40 lb sig gen, plugged into the wall, to the amplifier driving the thruster, forget the cable.  The sig gen, which puts out +10-+20 dBm, has plenty of beans to drive something like a standard gain horn transmit antenna, and get enough power across a short gap to a lightweight receive antenna on the test rig to drive the power amplifier to saturation.  If not, a low power, low noise pre-amp can be hooked to the receive antenna to boost the power up enough to drive the power amp.   Suitable preamps are readily available.  And cheap.

If one chooses to run the system off a battery, one will be forced to choose between run time and drive power.

If one chooses to power the system through some sort of low drag contacts, then 20-30 watt amplifiers are readily available covering the range of frequencies that have been discussed/tested, and run time can be essentially infinite. 

The devil is in the details, as always, but replacing the stiff RF cable with a short transmit/receive link will at least solve that problem.

Bob
Title: Re: EM Drive Developments
Post by: Mulletron on 11/16/2014 06:10 pm
Quote
Have you worked with microwave before?
Lol yes. I know what I'm doing. Radars and satcom are what I do. The biggest issue here is trying to couple rf from a 40 pound sweep generator to the test article because of the cable strain. Rf cables are heavy and rigid and using them would screw everything up. If I can't figure this out, I'm not doing it. I'd rather have a small rf generator balanced right there on the thing, running on batteries, but I'm not spending money buying one. I want to use an actual sweep generator so I can tune it and provide an rf sweep. But the cable issue is daunting. I'm thinking of using an xbee pro or putting an old wifi access point in CW mode. I have those. The best I can get in any case is +20dbm, so the test article needs to be small and light. The low powers involved would mean keeping the thing running for hours or days to see if any rotation happens.

Bob Ludwick sent me this response:




From:   Robert Ludwick
Sent:   Saturday, November 15, 2014 5:19 PM
To:   Dr. J. Rodal

In order to stop worrying about how to install a signal cable from the 40 lb sig gen, plugged into the wall, to the amplifier driving the thruster, forget the cable.  The sig gen, which puts out +10-+20 dBm, has plenty of beans to drive something like a standard gain horn transmit antenna, and get enough power across a short gap to a lightweight receive antenna on the test rig to drive the power amplifier to saturation.  If not, a low power, low noise pre-amp can be hooked to the receive antenna to boost the power up enough to drive the power amp.   Suitable preamps are readily available.  And cheap.

If one chooses to run the system off a battery, one will be forced to choose between run time and drive power.

If one chooses to power the system through some sort of low drag contacts, then 20-30 watt amplifiers are readily available covering the range of frequencies that have been discussed/tested, and run time can be essentially infinite. 

The devil is in the details, as always, but replacing the stiff RF cable with a short transmit/receive link will at least solve that problem.

Bob

Funny you mentioned the horn antennas. I don't have any horn antennas, but I can build them.
Tonight I'm doing an experiment here at work using 2, 9dbi omnis (not the best choice because they radiate energy in every direction) I had laying around. They are all I have at the moment. I'm going to place them next to each other in the near field of each antenna. Inject a calibrated 0dbm into one and measure the rsl, thus the free space loss after the signal is picked up from the rx antenna. I think just wireless coupling the energy into the device is probably much easier than using liquid metal. If the omni test works okay, I'll invest in a couple yagis or build a horn setup to get rf into the cavity. I horn is definitely better because they have a wide bandwidth, yagis not so much. I really want to sweep a broad range of frequencies, so two horns are definitely the ticket.

Results:

6db loss at 2450mhz with the omnis. Max energy available, using unamplified sig gen max output of +15dbm(0.03 watts), after transmitted through antennas and picked again is +9dbm(0.008 watts). Better than I expected actually. This simply isn't enough power, even with an unattenuated +15dbm. An amp is a must, so are directional antennas. Time to get/make some directional antennas. Too bad I sold all my wifi parabolic and panel antennas years ago.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/17/2014 12:21 am
http://www.amazon.com/Copper-Tumbler-Healing-Ayurvedic-Product/dp/B00IDDZRNG/ref=sr_1_22?ie=UTF8&qid=1416187099&sr=8-22&keywords=copper+tumbler

This is why we can't have nice things.... :)

http://www.fab-corp.com/product.php?productid=2026

I've spent a lot of money with fab corp. They're legit.

http://www.drivebywifiguide.com/TetraBrikHowTo.htm
http://www.turnpoint.net/wireless/cantennahowto.html

Title: Re: EM Drive Developments
Post by: DIYFAN on 11/17/2014 12:45 am
Only one of the copper cups left in stock.  Better snag it quick!
Title: Re: EM Drive Developments
Post by: Mulletron on 11/17/2014 01:06 am
I think it is a little too small (higher frequency). I'm trying to stay between 2400-2500mhz.
Title: Re: EM Drive Developments
Post by: DIYFAN on 11/17/2014 02:10 am
This one is 6 inches long, although the diameter is less.

http://www.ebay.com/itm/Ayurveda-Healing-Drinkware-Copper-Tumbler-Glasses-Set-of-2-personalized-gifts-/191305013772?_trksid=p2054897.l4275 (http://www.ebay.com/itm/Ayurveda-Healing-Drinkware-Copper-Tumbler-Glasses-Set-of-2-personalized-gifts-/191305013772?_trksid=p2054897.l4275)
Title: Re: EM Drive Developments
Post by: aero on 11/17/2014 02:40 am
I think it is a little too small (higher frequency). I'm trying to stay between 2400-2500mhz.
To bad your neighbor or good friend isn't a spinner. It would be straight forward to spin a cavity out of copper, making the mold is the expensive part with set-up second. Twenty years ago it was about $300 for a much more elaborate (parabolic) shape, and much larger mold (24 inches) turned out of hard wood. A soft wood mold is cheaper but won't last. But then you don't need to spin a lot of cavities.

There might be a neighborhood machine shop with a spinning lathe and the skills to use it. The commercial outfit I used did a really good job with surprisingly little by way of drawings. I gave them a hand drawn sketch and a list of reference distances, back plane to parabolic surface and lo - the mold maker turned it into a very nice, high fidelity product. Just make sure you include a mounting lip for the copper clad PC board around the large end but that should be easy, too.

I've reason to think that the PC board on the small end does not contribute because of the dielectric, but you can cut out the small end and attach a PC board if you think it is needed.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/17/2014 04:58 am
I gotta figure out how to explain to my boss why I really really need to borrow an expensive 83752B sweep generator for a science experiment in my basement. I did float him a hard copy of the "anomalous thrust" paper a few weeks ago so that might help.

My backup plan is to use wifi. I can get a CW (hacked) or wideband DSSS or OFDM 100mw signal out of those, not to mention access to dirt cheap 802.11 amplifiers.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/17/2014 09:25 am
I may have a very shallow grasp of what can be done or not with microwaves (at what practical efficiencies) but isn't it possible to use a hollow waveguide and interrupt it for 1mm or so, I mean a waveguide with a fixed part linked to wall plugged RF amp, and a mobile part (coaxial with rotation). Would the leak be too big ? Is a waveguide simply not appropriate for efficient power transmission ?

As I understand (weakly, feel free to educate me) RF is "transverse" (E and B orthogonal to propagation) so maybe any power RF wireless transmission scheme might show intrinsic torque between mobile part and fixed part (waveguide or antenna), no ? This could be mitigated by sampling at various relative orientations, or by having a freely rotating part (full 360°) to integrate and even out any orientation dependency ...

I wonder if a light enough "carousel" mounted on a sapphire cup bearing (near point like contact) could have low enough stiction to measure 10µN or so at ends of arm. See attached picture for the overall idea. Alternatively instead of a dry point like contact use a "floater bearing" in water (or liquid metal or low vapor pressure oil for vacuum compatibility). Probably high viscosity but no stiction.

Let it spin, measure thrust from acceleration profile first, then from equilibrium speed against viscosity. Check for periodic dependency of signal relative to angle of rotation (as "real" signal part wouldn't depend on that). Make the whole system as symmetric as possible around the axis (cylindrical walls around...).


Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/17/2014 12:11 pm
I gotta figure out how to explain to my boss why I really really need to borrow an expensive 83752B sweep generator for a science experiment in my basement.

Pretty cool that Mulletron can chat with his boss like that.  How expensive is that instrument anyway?

I wonder if a light enough "carousel" mounted on a sapphire cup bearing...

I thought that the plan was to hang it from fishing filament...

But what do I know.  Apparently I'm just a gamer (https://twitter.com/jmf56).  But hey:  Don't miss any updates!
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/17/2014 01:47 pm
Shawyer discloses using YBCO film both in his patent application and in reported prototype testing, with positive results.
I'll be interested to learn about that, but you need to remember that he had full funding for many years, including those when he won his patent; and he was defunded by the UK because he doesn't have anything and because his notions betray a complete lack of understanding of what group velocity is all about.  He is an engineer, not a physicist, and he does not have a real understanding of the concepts he based the device on.  If it is working, it is working by mistake and for reasons other than what Shawyer hoped, since what he hoped for was a violation of conservation.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/17/2014 02:07 pm
What is needed more than ever is additional confirmation of the effect.

You're all excited about the conference paper from Eagle, but validation does not require a bunch of home hobbyists look to produce results in the garage with chewing gum and duct tape.  Validation requires real labs doing real lab work they understand and can demonstrate on command, on a reliable force sensor of some sort. When I write that the thruster itself is the smallest part of the challenge, and that the instrumentation first, then the power system and then the thruster cost more than will fit in a home hobby budget, I am not making this stuff up.  People who say a superconducting chamber with cryogenics can be had for $2k don't know what they're talking about.  Who here has ever put cryogenics in vacuum?

I confess I am surprised that someone tested YBCO at Ghz and found it to work.  I'd note to you, it is not superconducting at those frequencies.  It has real resistance so it is not a superconductor, but the resistance is in tenths of an ohm and it is carrying 10A/mm width which is impressive, so the stuff may work well inside the resonator.

In any event, with NASA devoting resources across three centers to this, whatever home hobbyists come up with will make no difference, IMHO.  And I am not trying to be a wet blanket, as I have supported hobbyist work over the years.  As I said, I built a whole series of thrusters for Woodward back in 2007.   I'm just noting you can't skimp on the balance and vacuum and have people take your findings seriously.  Paul March had propellantless thrust in his extra bedroom in 2003-4 and no one took it seriously because he had no vacuum.

As to vacuum, if you want to be satisfied with E-3T, I can recommend the Welch 1400 as I used to own one and they're a very cost effective.  You can purchase them very cheap and rebuild them.  The rebuild kit is cheap too.  Really the most expensive part is the shipping.  They're beasts.

http://www.ebay.com/itm/AS-IS-Welch-Duo-Seal-Vacuum-Pump-Model-1400-w-A-O-Smith-1-3HP-Motor-RS1030A-/361112493011?pt=BI_Pumps&hash=item5413fb5bd3
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/17/2014 05:49 pm
...validation does not require a bunch of home hobbyists look to produce results in the garage with chewing gum...

I don't recall them saying they'd be using gum.  But what do I know?  I'm a koi farmer (http://www.zoominfo.com/p/John-Fornaro/700824481).
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/17/2014 06:02 pm
There might be a neighborhood machine shop with a spinning lathe and the skills to use it.
http://www.nextlinemfg.com/metal-3d-printing/?gclid=Cj0KEQiA1qajBRC_6MO49cqDxbYBEiQAiCl5_Heanp4RYgtNQc2YiqRYHNw7cMHmySmZxFBOZzfMUD0aAiP78P8HAQ
Title: Re: EM Drive Developments
Post by: zen-in on 11/18/2014 05:29 am
Shawyer discloses using YBCO film both in his patent application and in reported prototype testing, with positive results.
I'll be interested to learn about that, but you need to remember that he had full funding for many years, including those when he won his patent; and he was defunded by the UK because he doesn't have anything and because his notions betray a complete lack of understanding of what group velocity is all about.  He is an engineer, not a physicist, and he does not have a real understanding of the concepts he based the device on.  If it is working, it is working by mistake and for reasons other than what Shawyer hoped, since what he hoped for was a violation of conservation.

The same was said of Lee de Forest and his "audion" 100 years ago.  However there was never any question his invention worked.
Title: Re: EM Drive Developments
Post by: aero on 11/18/2014 06:21 am
I've been spending a lot of time over the last weeks installing and learning to use an FDTD program. It has taken me longer than it should, but I first had to install a Linux OS, then a MATLAB like program and learn how to use them. I'm still learning but have my FDTD program running now with the Brady cavity modeled as best we could divine it.
 
Later tonight I'm going to hit it with a Gaussian pulse around 1880.4 MHz, and hope in the morning to have resonate frequencies and Q values from the dimensions we have. That run will take about 6 hours on my single thread installation. If I need to, I will adjust the length and/or the big end diameter in order to find the right Q value. I've taken the small end internal diameter to be the size of the PE resonator disc and will leave that dimension alone.

Anyway, that's what I've been working on and I hope to have something interesting soon. And I hope I don't need to install and learn to use the multi-processor version of the program. Six hour runs aren't very long but it does limit me to 2 or 3 runs a day, and I was hoping to look at other things besides Q and dimensions.

(I wish I could afford something like this -)
 http://www.remcom.com/xf7?pi_ad_id=12808652781&gclid=CM_FsNvMg8ICFYdffgod4UQAqQ (http://www.remcom.com/xf7?pi_ad_id=12808652781&gclid=CM_FsNvMg8ICFYdffgod4UQAqQ)
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/18/2014 12:16 pm
To bad your neighbor or good friend isn't a spinner...

What's a spinner?  I mean, what do I know.  I'm just a magazine publisher (http://www.boardroominstitute.net/our_team.cfm).
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 12:33 pm
I may have a very shallow grasp of what can be done or not with microwaves (at what practical efficiencies) but isn't it possible to use a hollow waveguide and interrupt it for 1mm or so, I mean a waveguide with a fixed part linked to wall plugged RF amp, and a mobile part (coaxial with rotation). Would the leak be too big ? Is a waveguide simply not appropriate for efficient power transmission ?

As I understand (weakly, feel free to educate me) RF is "transverse" (E and B orthogonal to propagation) so maybe any power RF wireless transmission scheme might show intrinsic torque between mobile part and fixed part (waveguide or antenna), no ? This could be mitigated by sampling at various relative orientations, or by having a freely rotating part (full 360°) to integrate and even out any orientation dependency ...

I wonder if a light enough "carousel" mounted on a sapphire cup bearing (near point like contact) could have low enough stiction to measure 10µN or so at ends of arm. See attached picture for the overall idea. Alternatively instead of a dry point like contact use a "floater bearing" in water (or liquid metal or low vapor pressure oil for vacuum compatibility). Probably high viscosity but no stiction.

Let it spin, measure thrust from acceleration profile first, then from equilibrium speed against viscosity. Check for periodic dependency of signal relative to angle of rotation (as "real" signal part wouldn't depend on that). Make the whole system as symmetric as possible around the axis (cylindrical walls around...).

Need to change the direction of the thrust and the direction of rotation in your pictures:  (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=621179;image)

 it should be pointing the other way around, towards the bigger end, thus the rotation should be clock-wise in your picture.
Title: Re: EM Drive Developments
Post by: frobnicat on 11/18/2014 02:52 pm
...

Need to change the direction of the thrust and the direction of rotation in your pictures: 

pic...

 it should be pointing the other way around, towards the bigger end, thus the rotation should be clock-wise in your picture.

Ah yes, this should be spinning this way (or not at all). Thanks.

Can add a thin window transparent to microwaves to isolate the chamber from ambient pressure and make partial vacuum inside. Rotation could be measured with a mirror + laser = optical lever for small displacements and/or optical coder if it does spin.

Question remains : can a cavity (or cavities) can be fed through a waveguide, with a small "gap" in it between a fixed part and coaxial moving part ? Would be convenient to have a wall-plugged RF amp and send only waves to a light apparatus. I know so far I demanded rather more demo with fully integrated system...
Title: Re: EM Drive Developments
Post by: D_Dom on 11/18/2014 03:05 pm
What's a spinner? 
As opposed to cutting away metal from stock that is turning a spinning lathe forms sheet stock against a formblock. From formula one race cars wheels to rocket fuel tank domes.
http://www.instructables.com/id/Metal-Spinning-on-a-Wood-Lathe/
http://www.sundrymetalspinning.com/

edited to provide a more instructive video and offer my services, if anybody has a drawing they would like spun into three dimensions, let me know.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/18/2014 04:24 pm
Just want to make sure (given the flipping of thrust arrows above that just happened) that the emdrive (if it actually works) flies through the air pointy end first, right? Is the sign of thrust flipped in reaction less engines and I didn't get the memo?

Given the way the "thruster" is mounted in his space plane and the direction for cavity acceleration here:
http://www.emdrive.com/iac2014presentation.pdf

The signs for thrust are flipped in his presentation.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/18/2014 04:31 pm
Anyone else in build mode now? I'm gathering materials now, rf connectors and the like.

@Ron Stahl:
Quote
I'm just noting you can't skimp on the balance and vacuum and have people take your findings seriously.  Paul March had propellantless thrust in his extra bedroom in 2003-4 and no one took it seriously because he had no vacuum.

I'm not trying to be taken seriously. I'm not even taking this seriously. Building one is just for my enjoyment. I don't have access to a vacuum, nor will I spend more than a few bucks on this setup. What I'm going to do since I don't have vacuum, is put the test article inside a sealed container, pack it with tissue or foam to act as an air baffle and to distribute heat around evenly, and put that on the torsion balance.

Next subject:
Here's another emdrive theory paper I found:
https://hal.archives-ouvertes.fr/hal-01074608/document
This guy says he can make it better even.
Title: Re: EM Drive Developments
Post by: aero on 11/18/2014 04:38 pm
To bad your neighbor or good friend isn't a spinner...

What's a spinner?  I mean, what do I know.  I'm just a magazine publisher (http://www.boardroominstitute.net/our_team.cfm).

A spinner is a person or company who operates a spinning lathe. Google gives a long list of metal spinners, and some information. Look at the picture of the lathe and tools in the background.

http://en.wikipedia.org/wiki/Metal_spinning (http://en.wikipedia.org/wiki/Metal_spinning)

You will note from the picture that they are using metal mandrels. That is for high quantity production. For low quantity production they use wooden mandrels, but wooden mandrels wear out after a few hundred uses. That is, they flake or pit so become useless. The tools are about a meter long with a lever mechanical advantage of 10 - 20, so when the operator lays his full strength into the lever, the pressure on the mandrel gets pretty intense for wood to bear.
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 04:47 pm
Just want to make sure (given the flipping of thrust arrows above that just happened) that the emdrive (if it actually works) flies through the air pointy end first, right? Is the sign of thrust flipped in reaction less engines and I didn't get the memo?

Given the way the "thruster" is mounted in his space plane and the direction for cavity acceleration here:
http://www.emdrive.com/iac2014presentation.pdf

The signs for thrust are flipped in his presentation.

They claim they measured the thrust force pointing towards the big end, not the small end of the truncated cone.

Here is Shawyer's presentation the thrust is directed towards the big end.

http://4.bp.blogspot.com/-1a86Dh-Q6Rk/VFLSQlO8TgI/AAAAAAAA3x8/S2cXXAv3rcQ/s1600/emdrivedata.png[
Title: Re: EM Drive Developments
Post by: Mulletron on 11/18/2014 04:53 pm
 :)
http://www.youtube.com/watch?v=57q3_aRiUXs

Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 05:05 pm
:)
http://www.youtube.com/watch?v=57q3_aRiUXs


That YouTube is for the demonstrator engine, which Shawyer states exhibited force direction in both "reaction" and "thrust": take a look at his spreadsheet.

(http://4.bp.blogspot.com/-1a86Dh-Q6Rk/VFLSQlO8TgI/AAAAAAAA3x8/S2cXXAv3rcQ/s1600/emdrivedata.png)

In the text of his paper http://www.emdrive.com/IAC-08-C4-4-7.pdf  Shawyer states:  "The direction of acceleration was opposite to the direction of thrust".  If by direction of acceleration he means the acceleration of the center of mass of the EM Drive and other equipment , this definition is opposite to the common definition of thrust  However, NASA (Brady et al) also claim the thrust is pointing towards the big end.
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 05:18 pm
Just want to make sure (given the flipping of thrust arrows above that just happened) that the emdrive (if it actually works) flies through the air pointy end first, right? Is the sign of thrust flipped in reaction less engines and I didn't get the memo?

Given the way the "thruster" is mounted in his space plane and the direction for cavity acceleration here:
http://www.emdrive.com/iac2014presentation.pdf

The signs for thrust are flipped in his presentation.

Both Shawyer and NASA define the thrust force in these devices as pointing towards the big flat end, away from the dielectric at the small end of the truncated cone.

I don't understand your sarcastic tone.  Posting a video of Shawyer's "Demonstrator Engine" (which Shawyer claimed exhibited different measurements in "thrust" and "reaction" directions) moving in the opposite direction does not address the fact that NASA (Brady, March, White) and Shawyer defined the thrust as pointing towards the big end.

How do you address the fact that NASA defined the measured thrust is pointing towards the big end, away from the dielectric?

Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 05:30 pm
See how NASA defines the thrust direction here (@35 minutes) towards the short end, consistent with Shawyer's spreadsheet,  opposite from the dielectric located at the long end:


https://www.youtube.com/watch?v=Wokn7crjBbA


NASA defines the thrust direction they measured on the torsion pendulum towards the left, away from the dielectric:


<<<<<<<<<<<<<<<---------------------------------------------------------------------------------------
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 05:46 pm
Rather than being sarcastic about it, we should discuss and understand why:

A) Shawyer and NASA define the thrust direction towards the big end,

B) Shawyer states that the acceleration is in the opposite direction of the thrust.  This indeed is contrary to rocket and jet engines thrust definition.  Also the rotation in the Shawyer video is in the opposite direction to the one he uses for thrust.

If NASA is also defining thrust in the opposite direction to jet engines and rocket engines, why is NASA using this wrong definition?  Shouldn't NASA at least get this right?

Wasn't the movement of NASA's torsional pendulum towards the big end?

This adds to the confusion in these papers which makes anyone skeptical of the subject matter...
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/18/2014 05:50 pm
Anyone else in build mode now? I'm gathering materials now, rf connectors and the like.

@Ron Stahl:
Quote
I'm just noting you can't skimp on the balance and vacuum and have people take your findings seriously.  Paul March had propellantless thrust in his extra bedroom in 2003-4 and no one took it seriously because he had no vacuum.

I'm not trying to be taken seriously. I'm not even taking this seriously. Building one is just for my enjoyment. I don't have access to a vacuum, nor will I spend more than a few bucks on this setup. What I'm going to do since I don't have vacuum, is put the test article inside a sealed container, pack it with tissue or foam to act as an air baffle and to distribute heat around evenly, and put that on the torsion balance.

Next subject:
Here's another emdrive theory paper I found:
https://hal.archives-ouvertes.fr/hal-01074608/document
This guy says he can make it better even.
Sounds like you need to have a fire extinguisher.

So what is the point?  Suppose your balance moves.  Then what?  Suppose it doesn't move?  Then what?  You don't have any way to remove spurious sources so whether it moves or not, you won't have any kind of comnclusion you can make.  So what is the point?

This is why I have said now several times, you need to put the bulk of the effort into the instrumentation, not the thruster.   If you buy an acrylic aquarium:

http://www.ebay.com/itm/25-Gallon-Thick-Acrylic-Fish-Tanks-Various-Dimensions-/221398540134?pt=LH_DefaultDomain_0&hash=item338c619f66

and a used used roughing pump (which may even not need to be rebuilt) the real work is putting an acoustic enclosure around the pump (so your wife doesn't leave you) and running the had line to the aquarium.  It's really not that hard to do and all your other efforts will be worth something.

But you see why I am not a fan of unfunded efforts.  They turn into this--which is useless as is.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/18/2014 05:57 pm
If NASA is also defining thrust in the opposite direction to jet engines and rocket engines, why is NASA using this wrong definition?  Shouldn't NASA at least get this right?

Wasn't the movement of NASA's torsional pendulum towards the big end?

This adds to the confusion in these papers which makes anyone skeptical of the subject matter...

They did get it right.  The thrust is supposed to be generated to the larger end:

". . .Shawyer's paper includes the fundamental assertion underlying the theory: "[t]his force difference is supported by inspection of the classical Lorentz force equation F = q(E + νB). (1) If ν is replaced with the group velocity νg of the electromagnetic wave, then equation 1 illustrates that if vg1 is greater than vg2, then Fg1 should be expected to be greater than Fg2." This statement makes two assumptions which Shawyer does not substantiate and which may explain the discrepancy between Shawyer's predictions and those of conventional physics. First, Shawyer assumes that radiation pressure is the result of the Lorentz Force acting on charged particles in the reflecting material. This is refuted by Rothman and Boughn[36] and is not consistent with the standard theory of radiation pressure. Second, Shawyer asserts that quantum energy is transferred at the group velocity, and thus momentum of the photon and the consequent radiation pressure must vary with group velocity. Photon momentum varies with phase velocity. Group velocity measures the rate of propagation of information. The phase velocity is constant throughout the frustum resonator, consequently radiation pressure would not be expected to produce unbalanced forces."

http://en.wikipedia.org/wiki/EmDrive

Shawyer built this thing because he doesn't understand the difference between group velocity and phase velocity.  If it is producing thrust, it is producing thrust by accident.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/18/2014 06:19 pm
http://www.youtube.com/watch?v=GGTjy6atKMs 

30 seconds in shows acceleration in the other direction consistent with his statement, "The direction of acceleration was opposite to
the direction of thrust....." page 8 here: http://www.emdrive.com/IAC-08-C4-4-7.pdf

But inconsistent with slides 1, 2 and 3 here: http://www.emdrive.com/iac2014presentation.pdf
and the his video here: http://emdrive.com/dynamictests.html

Maybe it can be reversed. Much inconsistency here.

@Rodal
Quote
See how NASA defines the thrust direction here (@35 minutes) towards the short end, consistent with Shawyer's spreadsheet,  opposite from the dielectric located at the long end:

That stuff about Cannae above....doesn't follow. We're talking about Shawyer's design here.






Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 06:47 pm
....

@Rodal
Quote
See how NASA defines the thrust direction here (@35 minutes) towards the short end, consistent with Shawyer's spreadsheet,  opposite from the dielectric located at the long end:

That stuff about Cannae above....doesn't follow. We're talking about Shawyer's design here.

Yes it follows:

1) This is a thread about EM Drives in general.  Not a thread exclusively about Shawyer. 

2) This thread has as much or more detailed discussion about the NASA experiments by Brady et.al than by Shawyer.

3) Shawyer refers to the NASA direction of thrust in his spreadsheet, which I reproduce again:

(http://4.bp.blogspot.com/-1a86Dh-Q6Rk/VFLSQlO8TgI/AAAAAAAA3x8/S2cXXAv3rcQ/s1600/emdrivedata.png)
Title: Re: EM Drive Developments
Post by: DIYFAN on 11/18/2014 07:09 pm
Next subject:
Here's another emdrive theory paper I found:
https://hal.archives-ouvertes.fr/hal-01074608/document
This guy says he can make it better even.

Although fantastic as it seems, we ought to bide our time until some empirical evidence can be gathered to support or refute.  Working with metglas foils at room temperature would certainly be easier than cooling YBCO film with liquid nitrogen, in an attempt to get an amplified effect.

Seems tough to find pricing information on metglas 2714A.  Here is a datasheet and an invite for a price quote:
http://www.metglas.com/products/magnetic_materials/2714a.asp (http://www.metglas.com/products/magnetic_materials/2714a.asp)

Here is some relatively inexpensive metglas tape on ebay, but no indication of it being 2714A.
http://www.ebay.com/itm/Metglass-nanocrystaline-tape-for-MEG-generator-power-transformers-inverters-/321587303340?_trksid=p2054897.l4275 (http://www.ebay.com/itm/Metglass-nanocrystaline-tape-for-MEG-generator-power-transformers-inverters-/321587303340?_trksid=p2054897.l4275)

Lining the inner cavity of a small test article with such material might be a next step in our exploration.
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 07:12 pm
Next subject:
Here's another emdrive theory paper I found:
https://hal.archives-ouvertes.fr/hal-01074608/document
This guy says he can make it better even.

Although fantastic as it seems, we ought to bide our time until some empirical evidence can be gathered to support or refute.  Working with metglas foils at room temperature would certainly be easier than cooling YBCO film with liquid nitrogen, in an attempt to get an amplified effect.

Seems tough to find pricing information on metglas 2714A.  Here is a datasheet and an invite for a price quote:
http://www.metglas.com/products/magnetic_materials/2714a.asp (http://www.metglas.com/products/magnetic_materials/2714a.asp)

Here is some relatively inexpensive metglas tape on ebay, but no indication of it being 2714A.
http://www.ebay.com/itm/Metglass-nanocrystaline-tape-for-MEG-generator-power-transformers-inverters-/321587303340?_trksid=p2054897.l4275 (http://www.ebay.com/itm/Metglass-nanocrystaline-tape-for-MEG-generator-power-transformers-inverters-/321587303340?_trksid=p2054897.l4275)

Lining the inner cavity of a small test article with such material might be a next step in our exploration.

This paper quoted by Mulletron himself has a "propelling Thrust force T" also defined towards the big end.
Title: Re: EM Drive Developments
Post by: DIYFAN on 11/18/2014 07:34 pm
Upon closer inspection, it is suggested that only the plate having the larger diameter (R1) be made of metglas 2714A to obtain the amplified thrust in the indicated direction.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/18/2014 09:05 pm
I think these thrust inconsistencies can be attributed to Shawyer's assertions that this isn't a reaction less drive combined with him being fast and loose with precise terms such as thrust and reaction in order to support that. Literally every single thing Shawyer says that I put to the skeptical test, falls apart. It is certainly possible he built something exciting, but his explanations are lacking. Given that the rest of Shawyer's theory doesn't follow and the thrust paradoxes I presented here, his thrust direction explanation is suspect too.

The Nasa paper doesn't come right out and say it, but it seems the normal thrust orientation is thrust to the left. See figure 9 page 7 and see figure 11 page 9 of Brady et al paper. (This is a loose correlation because this could be normal to Cannae, not the chamber)

The Nasa paper didn't say they flipped the Shawyer design over or provide the sign of the measured thrust. (Did I miss it?)

Given the videos published by Shawyer and his illustration of his space plane (he wants it to go up), it is clear that the direction of thrust for the Shawyer tapered test article is toward the small end. (flying through space pointy end first) I'm not willing to pick this horse based on this paltry evidence, but that is the bias I have.

There is a LOT of inconsistencies here that need to be addressed in a skeptical way.

Other than the video I posted of the thing seemingly moving, is there anything in writing from Nasa that says the thrust was one sign or another?(Not Cannae)
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 09:32 pm
I think these thrust inconsistencies can be attributed to Shawyer's assertions that this isn't a reaction less drive combined with him being fast and loose with precise terms such as thrust and reaction in order to support that. Literally every single thing Shawyer says that I put to the skeptical test, falls apart. It is certainly possible he built something exciting, but his explanations are lacking. Given that the rest of Shawyer's theory doesn't follow and the thrust paradoxes I presented here, his thrust direction explanation is suspect too.

The Nasa paper doesn't come right out and say it, but it seems the normal thrust orientation is thrust to the left. See figure 9 page 7 and see figure 11 page 9 of Brady et al paper. (This is a loose correlation because this could be normal to Cannae, not the chamber)

The Nasa paper didn't say they flipped the Shawyer design over or provide the sign of the measured thrust. (Did I miss it?)

Given the videos published by Shawyer and his illustration of his space plane (he wants it to go up), it is clear that the direction of thrust for the Shawyer tapered test article is toward the small end. (flying through space pointy end first) I'm not willing to pick this horse based on this paltry evidence, but that is the bias I have.

There is a LOT of inconsistencies here that need to be addressed in a skeptical way.

Other than the video I posted of the thing seemingly moving, is there anything in writing from Nasa that says the thrust was one sign or another?(Not Cannae)


1) You are not explaining why you insist in not taking into account the NASA Cannae test, to determine the direction of thrust vis-a-vis the position of the dielectric and vis-a-vis the slighter larger end of the Cannae device.

2) If NASA's Paul March was consistent in placing the dielectric for NASA's truncated cone consistent with the dielectric placement for the Cannae, it necessarily follows that NASA's definition of thrust force and NASA's measurement in the pendulum was towards the big end of the truncated cone because:

a) we know that NASA placed the dielectric in the truncated cone at the small end (see picture attached below and White's August 2014 presentation at NASA Ames)

b) NASA is explicit that the thrust force for the Cannae occurred towards the end opposite to the location of the dielectric in the Cannae.

For the thrust force to have occurred towards the small end of NASA's truncated cone, it would mean that:

c) Paul March would have to have inconsistently placed the dielectric in the truncated cone (as compared to the Cannae device) in a direction opposite as to where he expected the thrust force to occur. Ron Stahl is on record stating that Paul March told him that it was March's idea to place the dielectric in the truncated cone in the first place.

d) the NASA authors would have been very sloppy in their writing of the "Anomalous..." report if they would have observed the thrust force to have occurred towards the small end of the truncated cone and not mention it, since this would have been the opposite to what they found and reported for the Cannae device.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/18/2014 09:40 pm
I think these thrust inconsistencies can be attributed to Shawyer's assertions that this isn't a reaction less drive combined with him being fast and loose with precise terms such as thrust and reaction in order to support that. Literally every single thing Shawyer says that I put to the skeptical test, falls apart. It is certainly possible he built something exciting, but his explanations are lacking. Given that the rest of Shawyer's theory doesn't follow and the thrust paradoxes I presented here, his thrust direction explanation is suspect too.

The Nasa paper doesn't come right out and say it, but it seems the normal thrust orientation is thrust to the left. See figure 9 page 7 and see figure 11 page 9 of Brady et al paper. (This is a loose correlation because this could be normal to Cannae, not the chamber)

The Nasa paper didn't say they flipped the Shawyer design over or provide the sign of the measured thrust. (Did I miss it?)

Given the videos published by Shawyer and his illustration of his space plane (he wants it to go up), it is clear that the direction of thrust for the Shawyer tapered test article is toward the small end. (flying through space pointy end first) I'm not willing to pick this horse based on this paltry evidence, but that is the bias I have.

There is a LOT of inconsistencies here that need to be addressed in a skeptical way.

Other than the video I posted of the thing seemingly moving, is there anything in writing from Nasa that says the thrust was one sign or another?(Not Cannae)


1) You are not explaining why you insist in not taking into account the NASA Cannae test, to determine the direction of thrust vis-a-vis the position of the dielectric and vis-a-vis the slighter larger end of the Cannae device.

2) If NASA's Paul March was consistent in placing the dielectric for NASA's truncated cone consistent with the dielectric placement for the Cannae, it necessarily follows that NASA's definition of thrust force and NASA's measurement in the pendulum was towards the big end of the truncated cone because:

a) we know that NASA placed the dielectric in the truncated cone at the small end
b) NASA is explicit that the thrust force for the Cannae occurred towards the end opposite to the location of the dielectric in the Cannae.

For the thrust force to have occurred towards the small end of the truncated cone, it would mean that:

c) Paul March would have to have inconsistently placed the dielectric in the truncated cone in a direction opposite as to where he expected the thrust force to occur.  Ron Stahl is on record stating that Paul March told him that it was March's idea to place the dielectric in the truncated cone in the first place.

d) the NASA authors would have been negligent in their writing of the "Anomalous..." report if they would have observed the thrust force to have occurred towards the small end of the truncated cone and not mention it, since this would have been the opposite of what they found for the Cannae device.

Your argument is based off the position of the dielectric, which doesn't follow. But if it did follow, your argument support my earlier assertions that putting the dielectric at the big or small end doesn't matter. I am glad to see you are back on board with dielectric thrust.

Side note, let's not get too serious about all this.
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 09:48 pm
I think these thrust inconsistencies can be attributed to Shawyer's assertions that this isn't a reaction less drive combined with him being fast and loose with precise terms such as thrust and reaction in order to support that. Literally every single thing Shawyer says that I put to the skeptical test, falls apart. It is certainly possible he built something exciting, but his explanations are lacking. Given that the rest of Shawyer's theory doesn't follow and the thrust paradoxes I presented here, his thrust direction explanation is suspect too.

The Nasa paper doesn't come right out and say it, but it seems the normal thrust orientation is thrust to the left. See figure 9 page 7 and see figure 11 page 9 of Brady et al paper. (This is a loose correlation because this could be normal to Cannae, not the chamber)

The Nasa paper didn't say they flipped the Shawyer design over or provide the sign of the measured thrust. (Did I miss it?)

Given the videos published by Shawyer and his illustration of his space plane (he wants it to go up), it is clear that the direction of thrust for the Shawyer tapered test article is toward the small end. (flying through space pointy end first) I'm not willing to pick this horse based on this paltry evidence, but that is the bias I have.

There is a LOT of inconsistencies here that need to be addressed in a skeptical way.

Other than the video I posted of the thing seemingly moving, is there anything in writing from Nasa that says the thrust was one sign or another?(Not Cannae)


1) You are not explaining why you insist in not taking into account the NASA Cannae test, to determine the direction of thrust vis-a-vis the position of the dielectric and vis-a-vis the slighter larger end of the Cannae device.

2) If NASA's Paul March was consistent in placing the dielectric for NASA's truncated cone consistent with the dielectric placement for the Cannae, it necessarily follows that NASA's definition of thrust force and NASA's measurement in the pendulum was towards the big end of the truncated cone because:

a) we know that NASA placed the dielectric in the truncated cone at the small end
b) NASA is explicit that the thrust force for the Cannae occurred towards the end opposite to the location of the dielectric in the Cannae.

For the thrust force to have occurred towards the small end of the truncated cone, it would mean that:

c) Paul March would have to have inconsistently placed the dielectric in the truncated cone in a direction opposite as to where he expected the thrust force to occur.  Ron Stahl is on record stating that Paul March told him that it was March's idea to place the dielectric in the truncated cone in the first place.

d) the NASA authors would have been negligent in their writing of the "Anomalous..." report if they would have observed the thrust force to have occurred towards the small end of the truncated cone and not mention it, since this would have been the opposite of what they found for the Cannae device.

Your argument is based off the position of the dielectric, which doesn't follow. But if it did follow, your argument support my earlier assertions that putting the dielectric at the big or small end doesn't matter. I am glad to see you are back on board with dielectric thrust.

Side note, let's not get too serious about all this.
When something doesn't agree with your unexplained postures you write that it doesn't follow.   What you mean is that you don't understand or worse, don't want to understand why somebody else thinks it follows.   No I am not with you regarding your readings of the Quantum Vacuum and their effect on a piece of Teflon or Polyethylene polymer.  They don't make any sense to me, from my academic studies or professional experience.   I don't know anybody at major universities that has such theories.  If it turns out that there is an interaction between these common polymers and the Quantum Vacuum in a microwave cavity that can practically serve for space propulsion I would be both very surprised and extremely delighted.

But it logically follows (to me) that for somebody  (like Paul March and Dr. White) who thinks that the dielectric placement in the microwave cavity has an interaction with the Quantum Vacuum, that they (Paul March and Dr. White) would place the dielectric always in a consistent manner both in the Cannae and the truncated cone, and if they wouldn't I would expect them to write about it and explain why they would have placed it inconsistently.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/18/2014 09:59 pm
Quote
When something doesn't agree with your unexplained postures you write that it doesn't follow.   What you mean is that you don't understand or worse, don't want to understand why somebody else thinks it follows.   No I am not with you regarding your readings of the Quantum Vacuum and their effect on a piece of Teflon or Polyethylene polymer.  They don't make any sense to me, from my academic studies or professional experience.   I don't know anybody at major universities that has such theories.  If it turns out that there is an interaction between these common polymers and the Quantum Vacuum in a microwave cavity that can practically serve for space propulsion I would be both very surprised and extremely delighted.

But it logically follows (to me) that for somebody  (like Paul March and Dr. White) who thinks that the dielectric placement in the microwave cavity has an interaction with the Quantum Vacuum, that they (Paul March and Dr. White) would place the dielectric always in a consistent manner both in the Cannae and the truncated cone, and if they wouldn't I would expect them to write about it and explain why they would have placed it inconsistently.

Well the matter is settled then. If you don't believe in the dielectric thrust scenario (even when the Brady et al paper said dielectric was important to thrust) (and the heaps and bounds of literature I've presented supporting it) you can't use the dielectric thrust placement as an argument for or agin. Especially when I've said multiple times that dielectric placement isn't the most fundamental thing here.

The paradoxes still remain. We'll hopefully get answers this fall from Eagleworks anomalous thrust Part II.

Thanks for keeping me on my toes with your spirited debate.
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 10:04 pm
Well the matter is settled then. If you don't believe in the dielectric thrust scenario (even when the Brady et al paper said dielectric was important to thrust) (and the heaps and bounds of literature I've presented supporting it) you can't use the dielectric thrust placement as an argument for or agin. Especially when I've said multiple times that dielectric placement isn't the most fundamental thing here.

The paradoxes still remain. We'll hopefully get answers this fall from Eagleworks anomalous thrust Part II.

Thanks for keeping me on my toes with your spirited debate.
Sorry to bruise your ego, but you are not (and neither I am) the arbiter of whether the dielectric placement is important or not to interact with the Quantum Vacuum. 

For the matter at hand (which way NASA defined thrust for the truncated cone) your opinion regarding dielectric orientation with respect to thust direction is completely irrelevant.  The relevant opinion is Paul March's and Dr. White's since they are the ones that decided where to place the dielectric in NASA's truncated cone.  My expectation is that (whether their Quantum Vacuum theories are right or wrong) Paul March and Dr. White are consistent researchers and that they placed the dielectric where they placed it (at the small end of the truncated cone) fora consistent and rational (in their viewpoint) reason.

Therefore my expectation is that thrust (as defined by NASA's Dr. White) for the truncated cone occurred pointing towards the big end,

a) consistent with Shawyer's spreadsheet graphics


(http://4.bp.blogspot.com/-1a86Dh-Q6Rk/VFLSQlO8TgI/AAAAAAAA3x8/S2cXXAv3rcQ/s1600/emdrivedata.png)

b) consistent with Aquino's depiction

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=621352;image)

c) consistent with the dielectric being at the opposite end of the Cannae and NASA's truncated cone
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 10:22 pm
A proof that NASA's thrust of the truncated cone occurred towards the big end is given by this picture:

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=621400;image)

which shows the support bolts at the right of the Faztek 1.5" by 1.5" beam.

This is consistent with Fig.11 for the Cannae that has the support bolts on the Faztek at the right of the Faztek and this is indicated as thrust to the right

Observe that Fig 9 has the support bolts to the left of the Faztek and this is indicated as thrust to the left

Also observe that when they had Canne thrust to the left (Fig. 9) the aluminum frame is different: it has a horizontal 45 degree Faztek to the right of the pendulum support arm that does not appear with the setup for thrust to the right of the Cannae (Fig 11) or the setup of the truncated cone.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/18/2014 10:31 pm
With something as important as this, I've set my ego aside. You know how many times I've commented about trying to break my own theory here. Egos hide the truth and replace it with self soothing. I just want to make sense of all this. There's no offense meant if I bring a critical eye at commonly held ideas. It is just healthy skepticism. I live by "The Skeptic’s Creed."

I want Humanity to advance, and I want my bleeping hover car already.....sheesh.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/18/2014 10:45 pm
These mounting bolts? How does bolting it down on one side or the other matter? That doesn't change sign. Flipping it changes sign. Bolts pull and push.
Title: Re: EM Drive Developments
Post by: aero on 11/18/2014 10:51 pm
Just to add my two cents worth, look at a couple of equations.

F = m * a , so force must be in the same direction as acceleration, and
F= mdot * Ve, so force must be in the same direction as Ve.

But guess what! Rocket exhaust velocity, Ve is in the direction opposite to rocket engine acceleration. Now, call one thrust and one force, but what ever you name them, Rocket exhaust velocity and rocket engine acceleration have different signs.
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 10:56 pm
These mounting bolts? How does bolting it down on one side or the other matter? That doesn't change sign. Flipping it changes sign. Bolts pull and push.
I could say "look deeper" like you have said sarcastically in the past.  But I will refrain.

I will point again that the FRAME is different.

When the bolts are at the left there is an extra 45 degree beam component.

When the bolts are at the right (both for the Cannae and the truncated cone) that 45 degree beam is missing



It appears that to have the pendulum move towards the left they flipped the whole frame 180 degrees around the vertical central axis of torsional pendulum

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=621400;image)

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=621404;image)

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=621408;image)
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 11:03 pm
Just to add my two cents worth, look at a couple of equations.

F = m * a , so force must be in the same direction as acceleration, and
F= mdot * Ve, so force must be in the same direction as Ve.

But guess what! Rocket exhaust velocity, Ve is in the direction opposite to rocket engine acceleration. Now, call one thrust and one force, but what ever you name them, Rocket exhaust velocity and rocket engine acceleration have different signs.
Inertial force is opposite to direction of acceleration. Inertia is a force that opposes motion.

One has to supply an equal in magnitude but opposite in direction external force to overcome inertia.

ma - F =0

D'Alembert's free body diagram is much clearer.  It is what I learnt at MIT, put everything on the left side and do a free-body diagram:

(this guy has the picture right but he screwed up the double differentiation with respect to time, it should be d2/dt2 instead)

the acceleration is to the right
the inertial force is to the left
the thrust force is to the right
According to D'Alembert there is equlibrium between inertia and thrust forces (in this simple case in which no other forces are present.  If other forces are present they all go on the same side of the equal to zero sign: all the forces have to algebraically add up to zero)

(http://engineeronadisk.com/V2/book_modelling/engineeronadisk-9.gif)
Title: Re: EM Drive Developments
Post by: aero on 11/18/2014 11:15 pm
I did finish my first attempt to compute Quality factor of the Brady cavity. It took much longer than I had hoped because I had to sleep on the cause of my computer shutting down every half hour. I awoke this morning and turned off the stupid Power management shut down which of course solved that problem. Then I let the run finished but it took 10 hours instead of six. I am now looking at the data and have decided that I won't get useful answers by simulating a perfect metal cavity. Some perfect values-

Frequency- 2.040922E+009; Q-  2,236,229.84
Frequency- 2.119509E+009; Q-  4,437,476.10

Q of 2 to 4 x106 is nice to imagine, but real metal will reduce that and maybe change the frequency. Its a start, though.

And just for giggles, I've attached an image of the fields. Red, magnetic and Blue electric, I think? It does show the effect of the dielectric. Note that the cavity is closed on both ends, it is just that the 0.002 inch copper ends draws to fine a line to show up with the graphic software. That is, if the end lines showed on the graphic they would not be true to the scale of the graphic. But the ends are included in the calculations, I get some really pretty fields without the big end closed.
Title: Re: EM Drive Developments
Post by: Rodal on 11/18/2014 11:27 pm
I did finish my first attempt to compute Quality factor of the Brady cavity. It took much longer than I had hoped because I had to sleep on the cause of my computer shutting down every half hour. I awoke this morning and turned off the stupid Power management shut down which of course solved that problem. Then I let the run finished but it took 10 hours instead of six. I am now looking at the data and have decided that I won't get useful answers by simulating a perfect metal cavity. Some perfect values-

Frequency- 2.040922E+009; Q-  2,236,229.84
Frequency- 2.119509E+009; Q-  4,437,476.10

Q of 2 to 4 x106 is nice to imagine, but real metal will reduce that and maybe change the frequency. Its a start, though.

And just for giggles, I've attached an image of the fields. Red, magnetic and Blue electric, I think? It does show the effect of the dielectric. Note that the cavity is closed on both ends, it is just that the 0.002 inch copper ends draws to fine a line to show up with the graphic software. That is, if the end lines showed on the graphic they would not be true to the scale of the graphic. But the ends are included in the calculations, I get some really pretty fields without the big end closed.

That (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=29276.0;attach=621434;image) looks very different from Egan:  (http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/TE2.gif)


and from NASA Brady et al  (they have opposite coloring field convention: blue magnetic and red electric )


Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/18/2014 11:33 pm
Paul March would have to have inconsistently placed the dielectric in the truncated cone (as compared to the Cannae device) in a direction opposite as to where he expected the thrust force to occur. Ron Stahl is on record stating that Paul March told him that it was March's idea to place the dielectric in the truncated cone in the first place.
I would just note that Paul said he was checking on these linear polymers for the tests since he was wary of the nonlinearities we've traditionally faced with perovskite ceramics.  He did not say why he wanted to put the stuff in there at all.

I think he may be trying to get something from Shawyer's crazy notion, that if one changes the velocity one changes the force on the chamber wall--despite Paul ought to know this is goofy, crazy, sub-highschool physics.  Here' the dopy reasoning:

http://emdrive.com/principle.html

Title: Re: EM Drive Developments
Post by: aero on 11/19/2014 12:34 am
Naa - Inertia is, in

physics : a property of matter by which something that is not moving remains still and something that is moving goes at the same speed and in the same direction until another thing or force affects it.

Inertia is a property of matter.  Inertia causes mater to resist. Matter will not go along willingly but due to Inertia, must be forced.
Title: Re: EM Drive Developments
Post by: aero on 11/19/2014 12:39 am
Don't read to much into my fields graphic. It might be weak/strong field. But I'm sure that blue is strong e-field. I'll find out and of course tell all :)

Quote
Briefly, the -Zc dkbluered makes the color scale go from dark blue (negative) to white (zero) to dark red (positive),


The cavity was excited with  an Ez field, (electric field) so the colors are a measure of the electric field. I could excite with a magnetic field if that would be helpful.
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/19/2014 01:06 am
Regarding Aero's effort:

Are we looking at some sort of concentration or bunching of electrical energy at the big end of the cavity?  If that is true, would said concentration amount to 'thrust?' 

Or did I just demonstrate my vast ignorance again?
Title: Re: EM Drive Developments
Post by: Rodal on 11/19/2014 01:27 am
Don't read to much into my fields graphic. It might be weak/strong field. But I'm sure that blue is strong e-field. I'll find out and of course tell all :)

Quote
Briefly, the -Zc dkbluered makes the color scale go from dark blue (negative) to white (zero) to dark red (positive),


The cavity was excited with  an Ez field, (electric field) so the colors are a measure of the electric field. I could excite with a magnetic field if that would be helpful.

There should  be an electric field and a magnetic field inside the cavity. 
In some modes (TE) the electric field is rotational (transverse).  Then the magnetic field is axial. It is obtained as (1/omega) times the curl of the transverse electric field. Where omega is the angular frequency (2 Pi f ).

In other modes (TM) the magnetic field is rotational (transverse).  Then the electric field is axial. It is obtained as (c^2/omega) times the curl of the transverse magnetic field.

Higher modes have the fields in smaller domains, with nodes (zero field points) in between the domains.


Preferably, in a numerical solution, you should get both the electric and magnetic fields at once. 

If you cannot get both field solutions at once, then by all means excite them separately (but of course keep exactly the same frequency and boundary conditions).
Title: Re: EM Drive Developments
Post by: Rodal on 11/19/2014 01:40 am
Don't read to much into my fields graphic. It might be weak/strong field. But I'm sure that blue is strong e-field. I'll find out and of course tell all :)

Quote
Briefly, the -Zc dkbluered makes the color scale go from dark blue (negative) to white (zero) to dark red (positive),


The cavity was excited with  an Ez field, (electric field) so the colors are a measure of the electric field. I could excite with a magnetic field if that would be helpful.



There should  be an electric field and a magnetic field inside the cavity. 
In some modes (TE) the electric field is rotational (transverse).  Then the magnetic field is axial. It is obtained as (1/omega) times the curl of the transverse electric field. Where omega is the angular frequency (2 Pi f ).

In other modes (TM) the magnetic field is rotational (transverse).  Then the electric field is axial. It is obtained as (c^2/omega) times the curl of the transverse magnetic field.

Higher modes have the fields in smaller domains, with nodes (zero field points) in between the domains.


Preferably, in a numerical solution, you should get both the electric and magnetic fields at once. 

If you cannot get both field solutions at once, then by all means excite them separately (but of course keep exactly the same frequency and boundary conditions).

Also please show (in addition to the current perspective) the fields in a direction looking perpendicular to the big diameter, so that we can check that (for example in this case) the electric field is indeed rotational (transverse) and that it goes to zero along the cone's axis.
Or at an angle, as shown in the below pictures
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/19/2014 01:49 am
But it logically follows (to me) that for somebody  ... who thinks that the dielectric placement in the microwave cavity has an interaction with the Quantum Vacuum, that they ... would place the dielectric always in a consistent manner both in the Cannae and the truncated cone, and if they wouldn't I would expect them to write about it and explain why they would have placed it inconsistently.

That is a charitable expectation, to be sure.  It cannot be claimed, however, that the device will thrust in the preferred direction based on the testimony of the experimentors, and that also, the placement of the dielectric can be inconsistent without an explanation of its cause or effect on the experimental results.

Inertia is a property of matter.

Sciama might disagree.

Or did I just demonstrate my vast ignorance again?

Not sure about that probability, I mean, what do I know?  I'm actually a poker player (http://pokerdb.thehendonmob.com/player.php?a=s&n=221902).
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/19/2014 03:57 am
Did someone state inertia is a property of matter?
Man, you may be right, but stating it doesn't make it true!
What do you think the good people have been exploring?
Sheesh!
Title: Re: EM Drive Developments
Post by: DIYFAN on 11/19/2014 06:01 am
Upon closer inspection, it is suggested that only the plate having the larger diameter (R1) be made of metglas 2714A to obtain the amplified thrust in the indicated direction.

In his recent paper,
https://hal.archives-ouvertes.fr/hal-01074608/document (https://hal.archives-ouvertes.fr/hal-01074608/document)
De Akino suggests using pulse modulated radar to produce high power microwaves during short time intervals (pulses).  Because of the pulsed nature, the overall power usage is relatively small.

Exploring this a bit further, I can imagine something like this Siemens built pulsed radar transmitter being used, which sells for about $1800 on ebay:
http://www.lesman.com/unleashd/catalog/sensors/sensors_probelr.html (http://www.lesman.com/unleashd/catalog/sensors/sensors_probelr.html)

Here is the user manual:
http://www.lesman.com/unleashd/catalog/sensors/Siemens-SITRANS-ProbeLR/SIEMENS-sitrans-probe-lr-man-a5e32337711-001-aa-2013-12.pdf (http://www.lesman.com/unleashd/catalog/sensors/Siemens-SITRANS-ProbeLR/SIEMENS-sitrans-probe-lr-man-a5e32337711-001-aa-2013-12.pdf)

It seems like it would be simple to slip the antenna of the transmitter through a simple round opening in the test article.  The pulses (i.e., measurements per minute) are adjustable from 0 to 99999 (pp. 55-56 of user manual).

One issue is that the frequency of this transmitter appears to be fixed at 6GHz, so it would not be possible to sweep the frequency to find resonance.  I suppose one could model and simulate the dimensions of the test article in advance (e.g., such as the interesting efforts being made by aero), determine its resonant frequency, and build the test article to fit the frequency.

It is also not clear to me what kind of power each of the pulses produces from this transmitter.  The input power is a maximum 30 V DC at 4 to 20 mA.  But since it is a pulsed microwave, this does not necessarily inform what the power would be for each pulse.

Thoughts?
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/19/2014 12:36 pm
...It is also not clear to me what kind of power each of the pulses produces from this transmitter.  The input power is a maximum 30 V DC at 4 to 20 mA.  But since it is a pulsed microwave, this does not necessarily inform what the power would be for each pulse.

Thoughts?

Well, the propulsive efficiency (http://en.wikipedia.org/wiki/Propulsive_efficiency) of the "advertised" experimental devices is very low.  For some reason, I seem to be the only person to put this in English:  The devices aim to convert electrical energy into linear momentum.  Therefore it is reasonable to consider the energy input as the analog of propellant.  While propulsive efficiency itself could be improved with a demonstration of the effect, it would make sense to crank up the input power.

Other than the pesky theoretical details, the thought to be "positive" results continue, after a decade or so of experimentation under wildly varying theories of operation, can barely be discerned from the underlying noise.

There have been a handful of suggestions up thread to increase the input power so as to increase the expected thrust results.  You aren't gonna make the Kessler run in a handful of *cough* parsecs on 4 to 20 mA, and I'm thinking you aren't gonna get "positive" results with such a small power input.

But hey.  What do I know? I'm just a gadfly (http://alumni.virginia.edu/forum/2013/01/15/help-defeat-confirmation-of-helen-dragas/).
Title: Re: EM Drive Developments
Post by: Rodal on 11/19/2014 01:58 pm
...It is also not clear to me what kind of power each of the pulses produces from this transmitter.  The input power is a maximum 30 V DC at 4 to 20 mA.  But since it is a pulsed microwave, this does not necessarily inform what the power would be for each pulse.

Thoughts?

Well, the propulsive efficiency (http://en.wikipedia.org/wiki/Propulsive_efficiency) of the "advertised" experimental devices is very low.  For some reason, I seem to be the only person to put this in English:  The devices aim to convert electrical energy into linear momentum.  Therefore it is reasonable to consider the energy input as the analog of propellant.  While propulsive efficiency itself could be improved with a demonstration of the effect, it would make sense to crank up the input power.

Other than the pesky theoretical details, the thought to be "positive" results continue, after a decade or so of experimentation under wildly varying theories of operation, can barely be discerned from the underlying noise.

There have been a handful of suggestions up thread to increase the input power so as to increase the expected thrust results.  You aren't gonna make the Kessler run in a handful of *cough* parsecs on 4 to 20 mA, and I'm thinking you aren't gonna get "positive" results with such a small power input.

But hey.  What do I know? I'm just a gadfly (http://alumni.virginia.edu/forum/2013/01/15/help-defeat-confirmation-of-helen-dragas/).

NASA Eagleworks has run and still proposes to run these experiments in the future at much lower power levels than even Shawyer or the Chinese.  NASA has run these experiments at only 2.6 and 16.9 watts input power: less than the power required to light an incandescent light bulb (compare this with the Chinese and Shawyer at 1000 watts).


Quote from: Pathological science  http://en.wikipedia.org/wiki/Pathological_science
Pathological science is the process by which "people are tricked into false results ... by subjective effects, wishful thinking or threshold interactions". The term was first  used by Irving Langmuir, Nobel Prize-winning chemist, during a 1953 colloquium at the Knolls Research Laboratory.
....

The maximum effect that is observed is produced by a causative agent of barely detectable intensity

When asked by the audience (@59 minutes)

https://www.youtube.com/watch?v=Wokn7crjBbA

where is this technology going to be 20 years from now (2034) Dr. White says that he has no answer to that. 

One doesn't get a sense of any great urge from NASA to really promptly advance this "Research" into anything (certainly not reminiscent of the late 1950's/early 1960's, if somebody would have asked where we were going to be in 20 years from then...)

"In 2008 the Russian Research Institute of Space Systems launched an experimental micro-satellite called Yubileiny (Jubilee) with a "non-traditional" engine which, according to Director Valery Mesnshikov, functions without ejecting reaction mass. Yubileiny (Jubilee), a Russian technology development satellite which was built by NPO PM to commemorate the 50th anniversary of the launch of Sputnik 1, the first artificial satellite to be placed into Earth orbit. It launched , 23 May 2008 aboard a Rockot rocket from LC-133 at the Plesetsk Cosmodrome. Launch was delayed from the end of 2007, and from earlier in 2008. It was a secondary payload to a cluster of three Gonets satellites, utilising the excess capacity of the carrier rocket.

However, it was later stated that "further developments" were needed and nothing further appears to be been published on Russian reactionless drives."


Title: Re: EM Drive Developments
Post by: Rodal on 11/19/2014 02:16 pm
...
But hey.  What do I know? I'm just a gadfly (http://alumni.virginia.edu/forum/2013/01/15/help-defeat-confirmation-of-helen-dragas/).

https://www.youtube.com/watch?v=KrQ5iSz-ch4
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/19/2014 02:49 pm
Well, the propulsive efficiency (http://en.wikipedia.org/wiki/Propulsive_efficiency) of the "advertised" experimental devices is very low.  For some reason, I seem to be the only person to put this in English:  The devices aim to convert electrical energy into linear momentum.
That is one interpretation, based upon certain explanations for the thrust being true and others not.  Generally though, any explanation that holds this view that this is a force transducer, leads to a violation of conservation.  The exception to this, is Woodward's theory which posits that this, if indeed it is generating Mach-Effects; is a gravinertial transistor, not a transducer.  It is not transforming electrical power into kinetic but rather, controlling the flow of inertial flux into and out of the active mass, and that therefore the vast bulk of the energy and power provided is not electrical but gravinertial.  This is why Woodward's theory alone does not violate conservation.  Also, it is why Woodward's theory alone posits hugely improved thrust to electrical power ratios than what we've seen--the power is not being transduced or converted into thrust.  It is merely controlling the flux that gives matter its mass.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/19/2014 03:43 pm
When asked by the audience (@59 minutes)

https://www.youtube.com/watch?v=Wokn7crjBbA

where is this technology going to be 20 years from now (2034) Dr. White says that he has no answer to that. 

One doesn't get a sense of any great urge from NASA to really promptly advance this "Research" into anything (certainly not reminiscent of the late 1950's/early 1960's, if somebody would have asked where we were going to be in 20 years from then...)

I think this is just Sonny being careful.  He's knows enough not to sound too enthusiastic.  And remember, this is a civil servant.  Unlike in private industry where we require results, NASA people can embark on a quest that lasts 50 years, and they often joke about how such and such a project is a "career-paycheck".  No different from the fusion research at the national labs.

Quote
"In 2008 the Russian Research Institute of Space Systems launched an experimental micro-satellite called Yubileiny (Jubilee) with a "non-traditional" engine which, according to Director Valery Mesnshikov, functions without ejecting reaction mass. Yubileiny (Jubilee), a Russian technology development satellite which was built by NPO PM to commemorate the 50th anniversary of the launch of Sputnik 1, the first artificial satellite to be placed into Earth orbit. It launched , 23 May 2008 aboard a Rockot rocket from LC-133 at the Plesetsk Cosmodrome. Launch was delayed from the end of 2007, and from earlier in 2008. It was a secondary payload to a cluster of three Gonets satellites, utilising the excess capacity of the carrier rocket.

However, it was later stated that "further developments" were needed and nothing further appears to be been published on Russian reactionless drives."

Russian propellantless drives are unusual in that they use two different kinds of hand-waving.  In the English speaking world, normally mad schemes have the ZPF wand waved over them to bless them and stop analysis of what is being proposed.  That trick works quite well.  In Russia they do the same, but they also sometimes use the "torsion physics" wand.  Since there is all of one physicist in the US who dabbles with Torsion Physics, there is really no one to do due diligence on such things.  I would just note that the Russian interest in twisting spacetime has been reported for many years, from weapons designs to propulsion, and there has never been demonstrated anything that remotely appears to give it any empirical authority.  It appears to be a scam from start to finish--same as ZPF and QVF physics.  However, the Torsion Field claims are still coming from Russia, from folks like Gennedy Shipov who really just has a Dean Drive but often convinces folks he has something real and useful.  Last I talked with Gennedy he said he had full funding in S. Korea.

http://en.wikipedia.org/wiki/Torsion_field_(pseudoscience)

http://en.wikipedia.org/wiki/Dean_drive
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/19/2014 03:56 pm
Rodal!  Spot on!
Title: Re: EM Drive Developments
Post by: Rodal on 11/19/2014 04:39 pm

I think this is just Sonny being careful.  He's knows enough not to sound too enthusiastic.  ....

Has he has been careful and not enthusiastic with his published conference papers extrapolating quick trips to Enceladus based on a completely unproven technology that he is running now and planning to run in the future at only 0.2% to 1.6% the power that even the Chinese and Shawyer have been running ?. 

Has he been careful and not enthusiastic in hinting that the EM Drive results may be due to Quantum Vacuum interaction (whose force he predicted should be perpendicular to the E and B fields, therefore perpendicular to the measured force in the Eagleworks microwave cavity tests)?. 

Or in proposing that there is an energy paradox even with conventional rocket engines using propellants?

But he must be careful and not too enthusiastic in orally answering a question as to where we could be in 20 years with this technology, asked by a youngster in a T-shirt during an informal internal NASA Ames presentation ? 

If he believes that these EM propellant-less Drives can really propel a spacecraft in space, what are the big engineering challenges to be overcome during the next 20 years that make it impossible for him to answer the question?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/19/2014 04:59 pm

I think this is just Sonny being careful.  He's knows enough not to sound too enthusiastic.  ....

Has he has been careful and not enthusiastic with his published  conference papers extrapolating quick trips to Enceladus based on a completely unproven technology that he is running now and planning to run in the future at only 0.2% to 0.16% the power that the Chinese and Shawyer have been running ?. 

Has he been careful and not enthusiastic in hinting that the EM Drive results may be due to Quantum Vacuum interaction (whose force he predicted should be perpendicular to the E and B fields, therefore perpendicular to the measured force in the Eagleworks microwave cavity tests)?. 

Or in proposing that there is an energy paradox even with conventional rocket engines using propellants?

Or in proposing that the negative mass necessary for the Alcubierre drive could be as small as the size of the Voyager probe?

But he must be careful and not too enthusiastic in orally answering a question as to where we are going to be in 20 years with this technology, asked by a youngster in a T-shirt during an informal internal NASA Ames presentation ?

I agree with your sentiments here.  This is why I don't understand the fascination with the E-M stuff when the M-E stuff is much more promising.  Trust me, I could add dozens of violations of common sense and scientific protocol to the short one you've just made.   The question is really, is Sonny representative of the entire propellentless "Space Drive" field?  The short answer is "yes, with one exception" and it is the exception--the thing that never gets the ZPFers support--that is noteworthy.

You seem to be surprised, but the ZPFers have completely dominated this field now for more than 20 years, and successfully kept everyone else out of funding.  This nonsense goes back before the very first days of the Breakthrough Propulsion Physics Project in the '90's and has not stopped since.  Marc Millis is a ZPFer.  Eric Davis is a ZPFer.  Sonny, General Pete Worden (Director of NASA Ames, who introduced Sonny in the above vid), Creon Levit--all ZPFers.  So where is the surprise coming from?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/22/2014 04:23 am
After a few days of really thinking hard about the build, here's what I'm planning:

I'm going to build the Casimir cone I designed, described and posted way back in the thread. I can do this pretty easily using copper sheet from http://basiccopper.com/thicknessguide.html or similar places. Building my own design seems logical and it is in keeping with the proposed theory common to Cannae(long vs short tube) and Shawyer's design(truncated cone); using dielectrics in asymmetrical cavities. Building my own design seems appropriate since I need to test all the ideas I've floated (informed by many others) about how EMdrives/Qthrusters/METs/MLTs/ACTs, whatever... might work and/or work better.

All the above devices are very similar in the most fundamental way, but their respective theories (therefore engineering) are what diverge the most.

An added bonus of using the 45 degree cone is that building it is as simple as twisting, soldering, and trimming lightweight copper sheet.

Given the nightmares of finding resonant frequencies of tapered frustums, especially with limited resources, another added bonus is that the 45 degree cone approach is infinitely tunable by inserting copper discs of varying diameter into the structure. Given that a resonant cavity must have a resonant mode at the frequency you're trying to excite it with in order to couple sufficiently, I think this approach will make things easier to work with. This way I don't have to build a lot of things. I can just build one thing and make subtle changes to it. It isn't easy for me to just get stuff here quickly because I'm currently living overseas and there isn't a Home Depot for thousands of miles. :( The local Leroy Merlin is as good as it gets. So I can get stuff, it just takes longer.

I'm hoping to inspire other folks out there to try their own experiment as well. Stay tuned.

I'm getting bored waiting on the "Anomalous thrust......" part II paper to come out.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/22/2014 04:50 am
After a few days of really thinking hard about the build, here's what I'm planning:...

Hey Mull!  Putta hot dog in there for me will ya?

Sorry, couldn't resist. 

Been Dancing (https://www.facebook.com/events/826094490787258/?notif_t=plan_reminder). 

Then went to the mixologist's birthday party.  Gittin' kinda late.  Lemme know when the h-d's are ready...
Title: Re: EM Drive Developments
Post by: Mulletron on 11/22/2014 05:49 am
 ::)
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/22/2014 06:01 am
You can't have a sharp end of your copper cavity though. You should try!
Good Luck mate! Really, I think you are ace!
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/22/2014 06:11 am
Am thinking or trying something with my friend and a copper frustum with a 900w magentron (out of a uWave oven of course.)
Planning to suspend the whole setup on piano wire...
What we hope is that we get a nice deflection cos of the high power.
Is this a good way to go about it?
Title: Re: EM Drive Developments
Post by: aero on 11/22/2014 06:19 am
I was beginning to worry that everybody else had quit. :)  I haven't quit but stuff gets in the way. I made an all night run night before last in order to make a movie of the field patterns. I got a whole slew of PNG files but the software that was supposed to convert them to a movie, won't! The stupid program i'm using spits out the PNG files at 32 MB each and it made about 100-200 of them. They're even to large to post and the quality isn't as good as I'd like.

Today I decided I had to get email up and running on my Ubuntu OS because I can't communicate to the discussion group without. That took a long time and then when I finally shut down and logged onto Windows, it was broken, couldn't identify user profile or some such thing. Couldn't repair it so restored from a save point. Lucky for me the machine made a save point last Sunday..

Back to trying to model the cavity. Reprogramming a lot of it so that it will be completely scalable with a characteristic length. About 7:00 pm I finally made a short run that produced something that looks line the Brady cavity, in profile. It's got some gaps that I don't like but its not so big a file, I'll try to attach it.

 Oh, I should mention that the end copper sheets are not to scale. With this image I was trying to see how well my model parts fit together and the 0.002" copper ends don't show up very well unless I increase the grid resolution - doing that increases the run time by a power of two and I want to finalize the model this week. It already runs 10 minutes just to make this simple sketch with very limited RF excitation.

Encouragement to you.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/22/2014 01:47 pm
Am thinking or trying something with my friend and a copper frustum with a 900w magentron (out of a uWave oven of course.)
Planning to suspend the whole setup on piano wire...
What we hope is that we get a nice deflection cos of the high power.
Is this a good way to go about it?

The magnetrons used in microwave ovens typically cost $25 on EBay and range up to about 1kW power.  The trouble with them is, they are not intended for high Q applications and will burn out if attached to a resonator.  I first learned of this in discussions with Paul March in 2007 when he and Sonny built their first Shawyer resonator with funding from Gary Hudson.  According to Paul, what you need is a continuous wave magnetron, which back then was much more difficult to find and I think the only stuff available on a budget was from Russia.  (Paul actually asked me to help him find one which proved to be a difficult task.)  Now they're pretty commonplace though, I have no idea why.  My guess is they have a commercial application in inductive heating or some such but I'm not familiar with it.

http://www.rell.com/products/Magnetrons/Magnetron-CW.html

As far as suspending it from a wire, that's a common practice.  I would just note to you, that especially if the wires are the power leads, clearly demonstrating any action one might observe is not thermal and result of the leads, is a huge task.  This is what Tom Mayhood faced in his masters thesis work back in the 90's and he was never successful clearly ruling out that what he had was thermal.  http://www.otherhand.org/home-page/physics/graduate-studies-in-physics-at-cal-state-university-fullerton/  And I would just note again, that none of these hobbyist efforts is worth anything if you can't rule out spurious sources.  There are many dozens of experiments that have been done over the last couple decades that are clearly useless, as they don't cope with the actual science of eliminating such possibilities.

So again I'd just note, that it is almost impossible for me to see how any low thrust experiment could be useful without providing vacuum.  It doesn't need to be much vacuum and it doesn't need to be expensive, but you'll be gluing lots of acrylic together to a hard line to a chamber, and you'll want to pay the cost of a decent roughing pump like the Welch Duoseal 1400.  If there were a way to do a decent experiment without vacuum, trust me I'd be all for that, but I don't see one.

As to thrust balance, there are lots of different designs.  The suspension notion has some merit, but if one is to completely eliminate thermal as a spurious source, those wires are serious trouble.  What I think  would be much better, and perhaps in many ways easier; would be to use magnetic suspension.  This is surprisingly easy to do and apart from the stray magnetic fields this generates, it solves a host of issues.  MIT is doing this and I have to say, I like it!  But when you're using these powerful fields for suspension, you both need to make judicious use of something like Mu metal during your testing (once you have thrust) to show you don't have b field coupling, and you'll need to make a fully powered test where your dummy load is as perfect as it can be.  For the MET, this is simple: just alter the phase between the 1w and 2w portions of the power supply as this should not matter much for coupling and so provide a good dummy.  For thruster designs that use a single frequency component, the task is harder.  You'll need to think on that.  Here though for your consideration is a small vid of the MIT Space Propulsion Lab balance in acton.  It's a fun setup.  There's nothing like floating stuff in the extra bedroom.  :-)

https://www.youtube.com/watch?v=47kzpfh2rMs

https://www.youtube.com/watch?v=_ieJ8s-zYWU



Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/22/2014 02:37 pm
Am thinking or trying something with my friend and a copper frustum...

I hope your friend's ok with that...
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/22/2014 02:38 pm
I was beginning to worry that everybody else had quit.

We have yet to hear from IslandPlaya's friend...
Title: Re: EM Drive Developments
Post by: Mulletron on 11/22/2014 10:16 pm
Am thinking or trying something with my friend and a copper frustum with a 900w magentron (out of a uWave oven of course.)
Planning to suspend the whole setup on piano wire...
What we hope is that we get a nice deflection cos of the high power.
Is this a good way to go about it?

The magnetrons used in microwave ovens typically cost $25 on EBay and range up to about 1kW power.  The trouble with them is, they are not intended for high Q applications and will burn out if attached to a resonator.  I first learned of this in discussions with Paul March in 2007 when he and Sonny built their first Shawyer resonator with funding from Gary Hudson.  According to Paul, what you need is a continuous wave magnetron, which back then was much more difficult to find and I think the only stuff available on a budget was from Russia.  (Paul actually asked me to help him find one which proved to be a difficult task.)  Now they're pretty commonplace though, I have no idea why.  My guess is they have a commercial application in inductive heating or some such but I'm not familiar with it.

http://www.rell.com/products/Magnetrons/Magnetron-CW.html

As far as suspending it from a wire, that's a common practice.  I would just note to you, that especially if the wires are the power leads, clearly demonstrating any action one might observe is not thermal and result of the leads, is a huge task.  This is what Tom Mayhood faced in his masters thesis work back in the 90's and he was never successful clearly ruling out that what he had was thermal.  http://www.otherhand.org/home-page/physics/graduate-studies-in-physics-at-cal-state-university-fullerton/  And I would just note again, that none of these hobbyist efforts is worth anything if you can't rule out spurious sources.  There are many dozens of experiments that have been done over the last couple decades that are clearly useless, as they don't cope with the actual science of eliminating such possibilities.

So again I'd just note, that it is almost impossible for me to see how any low thrust experiment could be useful without providing vacuum.  It doesn't need to be much vacuum and it doesn't need to be expensive, but you'll be gluing lots of acrylic together to a hard line to a chamber, and you'll want to pay the cost of a decent roughing pump like the Welch Duoseal 1400.  If there were a way to do a decent experiment without vacuum, trust me I'd be all for that, but I don't see one.

As to thrust balance, there are lots of different designs.  The suspension notion has some merit, but if one is to completely eliminate thermal as a spurious source, those wires are serious trouble.  What I think  would be much better, and perhaps in many ways easier; would be to use magnetic suspension.  This is surprisingly easy to do and apart from the stray magnetic fields this generates, it solves a host of issues.  MIT is doing this and I have to say, I like it!  But when you're using these powerful fields for suspension, you both need to make judicious use of something like Mu metal during your testing (once you have thrust) to show you don't have b field coupling, and you'll need to make a fully powered test where your dummy load is as perfect as it can be.  For the MET, this is simple: just alter the phase between the 1w and 2w portions of the power supply as this should not matter much for coupling and so provide a good dummy.  For thruster designs that use a single frequency component, the task is harder.  You'll need to think on that.  Here though for your consideration is a small vid of the MIT Space Propulsion Lab balance in acton.  It's a fun setup.  There's nothing like floating stuff in the extra bedroom.  :-)


Please elaborate on the bolded statements above.....Do you think a properly sealed, in an air tight container, insulated and baffled test article could suffice as a substitute for a vacuum, at least for lower power level studies? I'm planning on putting my test article in a sealed, foil lined box surrounded by insulation for example. I want to eliminate conduction convection and radiation as much as possible and not break the bank. Do you think that is enough? I understand the utility of using a hard vacuum as a pentamount test, but using the crawl walk run approach along with proper controls, we can glean useful results.

Also do you think that elaborate magnetic suspension is better than a low torsion string? Considering we're trying to measure mosquito fart levels of thrust here?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/22/2014 10:30 pm
Well, the propulsive efficiency (http://en.wikipedia.org/wiki/Propulsive_efficiency) of the "advertised" experimental devices is very low.  For some reason, I seem to be the only person to put this in English:  The devices aim to convert electrical energy into linear momentum.
That is one interpretation, based upon certain explanations for the thrust being true and others not.  Generally though, any explanation that holds this view that this is a force transducer, leads to a violation of conservation.  The exception to this, is Woodward's theory which posits that this, if indeed it is generating Mach-Effects; is a gravinertial transistor, not a transducer.  It is not transforming electrical power into kinetic but rather, controlling the flow of inertial flux into and out of the active mass, and that therefore the vast bulk of the energy and power provided is not electrical but gravinertial.  This is why Woodward's theory alone does not violate conservation.  Also, it is why Woodward's theory alone posits hugely improved thrust to electrical power ratios than what we've seen--the power is not being transduced or converted into thrust.  It is merely controlling the flux that gives matter its mass.

Can you please expand on the bolded statements above? This sounds very interesting. Please explain what you mean.

Perhaps Dr. Woodward himself could elaborate?

I get it, that this thread isn't about Mach Effect thrusters (and I never tried to shut you down on that point), but I think they are related (dielectrics interacting with the......QV, or as you say, distant matter...posted about before numerous times) and I really want to hear why they are important to humanity! I've studied them too. After all, they too supposedly convert electricity to thrust. Which is why we're all here. Be an ambassador. For the sake of humanity, sell... your... point! Tell us why they work. Tell us how they work. Tell us why (only METs?) work. Make your theory undeniable and...make it reality! In short, be a leader...........I want you to be successful. I want you to be right! I want you to lead us to the stars! I want you (and Woodward) to be the Zefram Cochrane WE have strived for, and dreamed of......to be more than we are now.

In the end, I don't care how we reach the stars. Only that we do.
Title: Re: EM Drive Developments
Post by: aceshigh on 11/23/2014 10:48 am
I prefer to reach the planets around other stars  ;D
Title: Re: EM Drive Developments
Post by: RotoSequence on 11/23/2014 12:05 pm
I prefer to reach the planets around other stars  ;D

I'd be quite happy with our own planets being within reach for a vacation.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/23/2014 01:51 pm
A couple videos I encountered a few months ago while trying to learn more about the QV and about how potentially Q-thrusters could possibly work:

The Edinburgh video has a lot of answers pertaining to issue @Ron Stahl brought up about why vacuum fluctuations don't gravitate.....and collapse the universe.
https://www.youtube.com/watch?v=JHc71K1sfSs

The Peter Milonni lecture was extremely valuable to me, trying to understand the QV and the Casimir effect. It helps to hold on to your head to keep it from exploding while watching it. See Youtube comments  :)

https://www.youtube.com/watch?v=12yjbyunRdM

Putting all this together with previous information about how the QV can interact with normal matter, (the transferring momentum from the QV papers and spontaneous symmetry breaking posted before) it becomes evident to me that the anomalous thrust is due to asymmetric Casimir forces. When you get a force imbalance on an object, it moves.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/23/2014 02:07 pm
BTW remember the thread about Whites warp drive theory where casimir force suitability as exotic matter was argued?

i have read comments about exotic matter in this context just being a weird name for the correct spacial conditions for creating the proper curvature to enable warps. It seems that it isn't or does not have to be exotic matter at all. and that is basically what White and others meant when he said that it appears that exotic matter isn't necessary to make warp drive work.

Anyway, to make this more precisely related to this thread casimir force does not have to be either exotic energy or mass to be useful to create the correct spacial distortion nor is casimir force the only "body double" for exotic matter, mass or energy. In these models it is possible mathematically at least to get the right topology without negative mass and so forth.

For some cosmological models that have the universe as we know it contained in a 'Brane which is embedded in the cosmic substrate known in Brane theory as the "bulk;" negative mass and energy are mathematically unnecessary for warps or wormholes. Bulk is the brane concepts version of the fictional plot device known as subspace.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/23/2014 02:31 pm
@Stormbringer
Quote
BTW remember the thread about Whites warp drive theory where casimir force suitability as exotic matter was argued?

i have read comments about exotic matter in this context just being a weird name for the correct spacial conditions for creating the proper curvature to enable warps.

Dude, if that Scottish professor is correct and what you're saying is correct, then hot damn!

Indeed it seems that we don't need exotic matter to achieve those ends. I don't know about wormholes and warp drives, but at least getting a ship to move without carrying around propellant. We can engineer the QV to obtain the same results as using exotic matter, without resorting to exotic matter, which may not exist.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/23/2014 03:36 pm
Indeed it seems that we don't need exotic matter to achieve those ends. I don't know about wormholes and warp drives, but at least getting a ship to move without carrying around propellant. We can engineer the QV to obtain the same results as using exotic matter, without resorting to exotic matter, which may not exist.
I think some types of exotic matter do exist.

Some have been experimentally produced in labs and others are being seriously considered for candidates for dark matter.

Additionally; in astrophysics and astronomy it is considered true that the super or hyper novae of certain types of star system can produce tons of heavy matter beyond that achievable by normal nova or super nova. so for example a red giant with a white dwarf or neutron star in it can make element 120 (just an example) and make it in all isotopic possibilities in quantities such that stable isotopes would persist and be available for acquisition and study and use. Normal novae cannot make elements beyond a certain atomic weight;  but there is likely places where this exotic matter can be found (problems of getting to it aside.)

Admittedly, the exotic matter that comes up in discussions of exotic propulsion are not in this class. but still exotic matter does exist. when someone says it doesn't they are either unaware of the facts or simply define exotic matter as having only the properties of negative energy or mass.

 the most recent articles i have read were about two super heavy baryons with an unusual quark configuration, a type of matter made of contiguous masses of quarks that forms macroscopic bulks of matter that may be responsible for a portion of dark matter, a pentaquark and so on.
Title: Re: EM Drive Developments
Post by: Rodal on 11/23/2014 03:55 pm
One of the very few physicists at top institutions that dares write about the science-fiction of wormholes,  Kip Thorne (Professor of Theoretical Physics, Emeritus at CalTech) wrote the following letter to the Wall Street Journal (this weekend's edition, page A12,  November 22/23 2014), to clarify some pretense (triggered by the movie "Interstellar") about the feasibility of whether our human civilization could actually travel through wormholes to reach planets in other stars: (bold added for emphasis)

Quote from: Prof. Kip Thorne, CalTech
Regarding the Weekend Interview on Nov. 15 by Sohrab Ahmari ("Finding our place in the stars"), in which I was interviewed:

We physicists have tried to figure out what the laws of physics say about wormholes.  We don't yet have an absolutely firm answer, but it appears very likely that the physical laws prevent wormholes from ever existing, and that if wormholes can exist, they cannot occur naturally - they must be created by some very advanced civilization, such as the bulk beings in "Interstellar".


(http://si.wsj.net/public/resources/images/BN-FO321_winter_J_20141114174408.jpg)
Title: Re: EM Drive Developments
Post by: Mulletron on 11/23/2014 04:43 pm
Indeed, building on our previous discussion on the nature of the QV itself (has weight but gravitationally repulsive, possible QV suitability as exotic matter analogue), Dr. White repeatedly hints that he is exploring this line of research in his warp experiments. He doesn't come out and say it. He is testing Qthrusters on a test bench designed to look for warped spacetime.  At the 55:30 mark on through 58:30, he gets a tough question regarding this and he shies away from that. He's essentially saying (or I am, not sure) that creating a perturbed state in the QV is changing the shape of spacetime from flat to sloped. He keeps his core concepts about Q-thruster physics close at hand and doesn't make too many sensational claims. A good move.

http://www.youtube.com/watch?v=Wokn7crjBbA
Title: Re: EM Drive Developments
Post by: Rodal on 11/23/2014 05:22 pm
CalTech's Prof. Kip Thorne, also just wrote a popular, 336 pages long book titled "The Science of Interstellar"

http://www.amazon.com/Science-Interstellar-Kip-Thorne/dp/0393351378/ref=sr_1_1?ie=UTF8&qid=1416766293&sr=8-1&keywords=kip+thorne+interstellar

Sorry, he doesn't mention in his book the Quantum Vacuum, negative mass, the Mach Effect, Prof. Woodward's theory or experiments, nor does he mention Dr. White's warp drive theory or his Q-Drive experiments.  Thorne does mention LIGO, Randall, Hawking, Witten and Einstein.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/23/2014 05:34 pm
Indeed, building on our previous discussion on the nature of the QV itself (has weight but gravitationally repulsive, possible QV suitability as exotic matter analogue), Dr. White repeatedly hints that he is exploring this line of research in his warp experiments. He doesn't come out and say it. He is testing Qthrusters on a test bench designed to look for warped spacetime.  At the 55:30 mark on through 58:30, he gets a tough question regarding this and he shies away from that. He's essentially saying (or I am, not sure) that creating a perturbed state in the QV is changing the shape of spacetime from flat to sloped. He keeps his core concepts about Q-thruster physics close at hand and doesn't make too many sensational claims. A good move.



His warp interferometer experiment has implicit in it that the q thruster or a similar device does warp space.

If it didn't he would have nothing to generate the warp he hopes to detect. And it has to be more than just the mass of his test article. if his interferometer was sensitive enough he could hypothetically at least measure the curvature due to the mass of atoms the beam passes by in the instrument. but it is not that sensitive. he hopes that running energy through it will produce a larger curvature than it's inert mass would and thus reach the threshold of sensitivity of the interferometer and his analysis technique.

The Juday White interferometer is not sensitive enough to detect a micro-warp of the magnitude Dr White believes he is creating according to peer reviewed papers in response to his experiment. This is why he is currently learning another type of interferometer for his next series of experiments.

http://arxiv.org/ftp/arxiv/papers/1407/1407.7772.pdf
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/23/2014 05:39 pm
@Rodal; in that caricature he looks like a cross between Alfred E. Newman and a garden gnome. :P
Title: Re: EM Drive Developments
Post by: Rodal on 11/23/2014 05:49 pm
@Rodal; in that caricature he looks like a cross between Alfred E. Newman and a garden gnome. :P
@Stormbringer, that's the WSJ caricature, did you expect Thorne to look like Michael Caine?   :).  In fairness to Prof. Thorne, here is a recent picture of him:

(http://cdn3.whatculture.com/wp-content/uploads/2013/01/10838_Kip_Thorne.jpeg)
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/23/2014 06:11 pm
a little less Alfred E Newman-y there. Still resembles a gnome though...

But Prof Thorne was the one who suggested Einstein Rosen Bridges for Carl Sagans Sci Fi movie. it's hardly likely he really meant natural wormholes do not occur. He probably meant rather that natural macroscopic wormholes that can be used for travel do not exist or at least do not exist nearby.

True story; there are currently astronomical missions being planned to try to see if some blackholes are in fact "just" wormholes.

as far as i know no one has ruled out blackholes as being a type of wormhole either. and certain things in physics from the range of the strong force to gravity to quantum mechanics imply wormholes must exist. I have read in the last year or so many science articles on such applications of wormholes.

recent ones said entanglement and gravity required wormholes to work.
Title: Re: EM Drive Developments
Post by: Rodal on 11/23/2014 06:20 pm
a little less Alfred E Newman-y there. Still resembles a gnome though...

But Prof Thorne was the one who suggested Einstein Rosen Bridges for Carl Sagans Sci Fi movie. it's hardly likely he really meant natural wormholes do not occur. He probably meant rather that natural macroscopic wormholes that can be used for travel do not exist or at least do not exist nearby.

True story; there are currently astronomical missions being planned to try to see if some blackholes are in fact "just" wormholes.

as far as i know no one has ruled out blackholes as being a type of wormhole either. and certain things in physics from the range of the strong force to gravity to quantum mechanics imply wormholes must exist. I have read in the last year or so many science articles on such applications of wormholes.

recent ones said entanglement and gravity required wormholes to work.

Prof. Thorne has been clear that << it appears very likely that the physical laws prevent wormholes from ever existing>>.  That's why he went through the trouble to write the letter to the WSJ this weekend: to make it clear that it is his present opinion that naturally occurring wormholes are very unlikely to ever exist. Ditto in his recent book (quoted above).  He has investigated "natural occurring wormholes" and he has concluded that they are unstable: if they were ever to form they would naturally collapse almost instantaneously.

Here is a direct link to Prof. Thorne's letter:

http://online.wsj.com/articles/the-laws-of-physics-regarding-wormholes-1416606575
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/23/2014 06:48 pm
The forces that make wormholes unstable can (so easily that it could happen by accident) be used to prevent them from closing up. the Cosmic Back Pressure mechanism can be used to keep a wormhole open even though it was originally invoked to destroy wormholes as a FTL shortcut. what is probably true is no macroscopic wormholes were created after the inflationary period of the big bang.

Additionally there is the fact that quantum level wormholes are likely to exist as they are now integral to several physics processes.

and finally:

http://thespacereporter.com/2014/05/new-gravity-telescope-might-find-a-wormhole-in-our-own-galaxy/

and

http://guardianlv.com/2014/05/supermassive-black-hole-could-be-a-wormhole/

:)

Title: Re: EM Drive Developments
Post by: Mulletron on 11/23/2014 07:24 pm
Indeed, building on our previous discussion on the nature of the QV itself (has weight but gravitationally repulsive, possible QV suitability as exotic matter analogue), Dr. White repeatedly hints that he is exploring this line of research in his warp experiments. He doesn't come out and say it. He is testing Qthrusters on a test bench designed to look for warped spacetime.  At the 55:30 mark on through 58:30, he gets a tough question regarding this and he shies away from that. He's essentially saying (or I am, not sure) that creating a perturbed state in the QV is changing the shape of spacetime from flat to sloped. He keeps his core concepts about Q-thruster physics close at hand and doesn't make too many sensational claims. A good move.



His warp interferometer experiment has implicit in it that the q thruster or a similar device does warp space.

If it didn't he would have nothing to generate the warp he hopes to detect. And it has to be more than just the mass of his test article. if his interferometer was sensitive enough he could hypothetically at least measure the curvature due to the mass of atoms the beam passes by in the instrument. but it is not that sensitive. he hopes that running energy through it will produce a larger curvature than it's inert mass would and thus reach the threshold of sensitivity of the interferometer and his analysis technique.

The Juday White interferometer is not sensitive enough to detect a micro-warp of the magnitude Dr White believes he is creating according to peer reviewed papers in response to his experiment. This is why he is currently learning another type of interferometer for his next series of experiments.

http://arxiv.org/ftp/arxiv/papers/1407/1407.7772.pdf
Thanks for digging up that paper above. That's good stuff!

Well if Dr. White wants to warp spacetime using the QV, and that if the QV is gravitationally repulsive, it implies (to me at least) that anti matter must fall up instead of down, or at least fall down at a different rate than normal matter. If matter and antimatter don't attract exactly the same with each other and themselves, this means that gravitation could exhibit a dipole moment. This would also imply that gravitation has a sign, much like charge does. Let's hope that the AEGIS experiment finds evidence of this. http://aegis.web.cern.ch/aegis/home.html

A few days ago I found this article. http://www.sciencedaily.com/releases/2014/11/141119084506.htm
I dismissed it as just something neat with no real meaning. In retrospect, couldn't this imply that gravitation could be showing signs of being polarizable, evidence of a sign other than just positive? How else would all these quasars line up with each other and with their local filament?
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/23/2014 08:03 pm
As to the alignment of quasars indicating a particular cause (being gravity) i just don't know enough to say. my instinct says it's possible there are other causes or explanations. It seems like it could be gravity related; but i am not conversant with all of the elements implicit in the problem.

( hey maybe it proves Mach's principle :)  )

Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 01:44 pm
As to thrust balance, there are lots of different designs.  The suspension notion has some merit, but if one is to completely eliminate thermal as a spurious source, those wires are serious trouble.  What I think  would be much better, and perhaps in many ways easier; would be to use magnetic suspension.  This is surprisingly easy to do and apart from the stray magnetic fields this generates, it solves a host of issues.  MIT is doing this and I have to say, I like it!  But when you're using these powerful fields for suspension, you both need to make judicious use of something like Mu metal during your testing (once you have thrust) to show you don't have b field coupling, and you'll need to make a fully powered test where your dummy load is as perfect as it can be.  For the MET, this is simple: just alter the phase between the 1w and 2w portions of the power supply as this should not matter much for coupling and so provide a good dummy.  For thruster designs that use a single frequency component, the task is harder.  You'll need to think on that.  Here though for your consideration is a small vid of the MIT Space Propulsion Lab balance in acton.  It's a fun setup.  There's nothing like floating stuff in the extra bedroom.  :-)


Quote
Please elaborate on the bolded statements above.....Do you think a properly sealed, in an air tight container, insulated and baffled test article could suffice as a substitute for a vacuum, at least for lower power level studies? I'm planning on putting my test article in a sealed, foil lined box surrounded by insulation for example. I want to eliminate conduction convection and radiation as much as possible and not break the bank. Do you think that is enough? I understand the utility of using a hard vacuum as a pentamount test, but using the crawl walk run approach along with proper controls, we can glean useful results.

Also do you think that elaborate magnetic suspension is better than a low torsion string? Considering we're trying to measure mosquito fart levels of thrust here?
A sealed box is a pretty good cheap and easy test.  In fact Woodward used this to debunk the asymmetric Lifter stuff back in the '90's.  He put a lifter in a box and even though the Lifter could lift the weight of the box while it was outside the box, it did not generate any net thrust when in the box.  (You have to actually weigh the box to know there is not some small force other than ion wind.)  So obviously this thrust was just ion wind.  It's a nice alternative to a larger system, but even then people argued with him that he hadn't provided what they considered adequate scientific controls.  For a cheap test, a box is fine so long as you know it is completely airtight and you can always test outside the box for fields.  (An optical on/off switch is good here but be certain the eye is completely sealed.)  Getting a small amount of Mu metal foil and waving it around the box is actually better than trying to make your own foil lined box because Mu metal needs to be properly annealed (in a magnetic field in hydrogen atmosphere) to maintain its anisotropy--you can't make a full magnetic shield by folding and soldering it unless you anneal it afterward.  What you can do is if you have a supposed thrust signature that you want to demonstrate is not the result of magnetic coupling, just wave it around outside the box.  Since it is 100,000X more permeable than air, you'll definitely alter any supposed magnetic coupling by doing this and you'll see changes in measured signature.

Torsion strings are susceptible to very pronounced thermal effects.  The trouble with them is not so much isolating them from thermal, but rather in demonstrating you have done this.  You can invent your own protocols for this.  Find a way to heat the suspension wires and show this doesn't give what looks like a thrust signature.  Good protocols can often make a relatively weak system perform robustly.  The question really becomes whether the protocols themselves result in a method that is still flexible and utilitarian enough to get the job done.  Same with vacuum.  People say they want to see E-12T to know there's no ion wind, but ion wind scales with pressure so if you know you have the same thrust signature at E-1T and E-3T, you know you don't have ion wind and can get by with a cheaper, more utilitarian system.  And this is a case where the cheaper system is better--acrylic chambers like Woodward's and the one in the vid at MIT, don't couple with powerful e fields.  Stainless--necessary for hard vacuum--does.  You can save a year's worth of hard work coping with stainless coupling by not using stainless.  George Hathaway chronicled his frustrations at his lab in Canada doing this and Eagle took a year as well.  It's a big issue especially if you're on a timeline with a professional budget.  Still if you have the budget, polycarb like Lexan is better than acrylic since it has a much lower vapor pressure and can sustain more vacuum.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 02:06 pm
Well, the propulsive efficiency (http://en.wikipedia.org/wiki/Propulsive_efficiency) of the "advertised" experimental devices is very low.  For some reason, I seem to be the only person to put this in English:  The devices aim to convert electrical energy into linear momentum.
That is one interpretation, based upon certain explanations for the thrust being true and others not.  Generally though, any explanation that holds this view that this is a force transducer, leads to a violation of conservation.  The exception to this, is Woodward's theory which posits that this, if indeed it is generating Mach-Effects; is a gravinertial transistor, not a transducer.  It is not transforming electrical power into kinetic but rather, controlling the flow of inertial flux into and out of the active mass, and that therefore the vast bulk of the energy and power provided is not electrical but gravinertial.  This is why Woodward's theory alone does not violate conservation.  Also, it is why Woodward's theory alone posits hugely improved thrust to electrical power ratios than what we've seen--the power is not being transduced or converted into thrust.  It is merely controlling the flux that gives matter its mass.

Can you please expand on the bolded statements above? This sounds very interesting. Please explain what you mean.

Shawyer's model and White's model, both paint this picture that electrical energy is being transduced into kinetic energy.  The QVF model is the simplest to understand in this regard, since it's really just a plasma thruster.  All the energy is in the drive as with an ion engine, but the propellant is supposedly virtual, so it's just a transducer.  There's no way to account for seeming violations of conservation in such a system.

Woodward's thruster is not a transducer.  It's a transistor.  It doesn't convert electrical into kinetic.  It controls the flow of gravinertial flux--the stuff that through the universe's gravitational field, gives matter its mass--in and out of the thruster.  Each Mach Effect cycle, the active mass in the thruster goes through a full 2w cycle, so the mass gets heavier, than lighter then heavier then lighter--4 discrete changes in each Mach Effect event.  Gravinertial flux is flowing from the rest of the universe, into the active mass when it gets heavier, and back out when it gets lighter, and that flux is linked to the entire universe.  So Mach Effect Thrusters are not transducers that covert energy, they're transistors, like on a sailboat.  On a large racing yacht, if you were to look at the electrical energy driving the winches for the sails, and look at the kinetic energy of the boat through the water, you would appear to have a conservation violation, since the vast majority of the power into the system is in the wind, not the winch.  Same with MET's.  The real power is in the gravinertial flux--the universal wind created by and controlled by the MET.  So you have to look at the entire system--the universe-- to do any meaningful conservation calculations with MET's.

Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 02:17 pm
Indeed, building on our previous discussion on the nature of the QV itself (has weight but gravitationally repulsive, possible QV suitability as exotic matter analogue), Dr. White repeatedly hints that he is exploring this line of research in his warp experiments. He doesn't come out and say it. He is testing Qthrusters on a test bench designed to look for warped spacetime.  At the 55:30 mark on through 58:30, he gets a tough question regarding this and he shies away from that. He's essentially saying (or I am, not sure) that creating a perturbed state in the QV is changing the shape of spacetime from flat to sloped.
This is why M-E Theory and QVF are incompatible--they make contradictory claims about where inertia comes from.  The ZPF theory White's QVF model rests upon and is an extension of, stipulates that matter gets its mass from the virtual particles in the ZPF.  M-E theory stipulates that matter gets its mass from the gravitational connection between all the universe's parts but chiefly from the farthest parts as per Mach's Principle.  Both these could be wrong, but they can't both be right because they contradict one another.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 02:44 pm
CalTech's Prof. Kip Thorne, also just wrote a popular, 336 pages long book titled "The Science of Interstellar"

http://www.amazon.com/Science-Interstellar-Kip-Thorne/dp/0393351378/ref=sr_1_1?ie=UTF8&qid=1416766293&sr=8-1&keywords=kip+thorne+interstellar

Sorry, he doesn't mention in his book the Quantum Vacuum, negative mass, the Mach Effect, Prof. Woodward's theory or experiments, nor does he mention Dr. White's warp drive theory or his Q-Drive experiments.  Thorne does mention LIGO, Randall, Hawking, Witten and Einstein.

I was just listening to him Saturday: 

http://www.sciencefriday.com/segment/11/21/2014/into-the-wormhole-the-science-of-interstellar.html

You are familiar that he wrote the definitive study on how to build a wormhole?  The story as I've heard it is, that his friend Carl Sagan asked him if he could use black holes for interstellar flight back when Sagan was writing his little book Contact, which was later turned into the movie with Jodie Foster and Matthew McConaughey.  Thorne went to work on this with his graduate students and came back to say, "no, you can't use a black hole, but you can use a wormhole".  Thorn then published the work he and his grad students did on wormholes and so the math is there to create them since 1988.  The trouble is, to pass people through, you need an "absurdly benign wormhole" where the gravitational gradient at the throat is low enough that it won't crush a human being.  For this you need about a jupiter mass of negative matter, which is hard to find.

Good thing Woodward found it locked up inside the electron.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/24/2014 03:59 pm

This is why M-E Theory and QVF are incompatible--they make contradictory claims about where inertia comes from.  The ZPF theory White's QVF model rests upon and is an extension of, stipulates that matter gets its mass from the virtual particles in the ZPF.  M-E theory stipulates that matter gets its mass from the gravitational connection between all the universe's parts but chiefly from the farthest parts as per Mach's Principle.  Both these could be wrong, but they can't both be right because they contradict one another.
this is all true but it is also true that White could be dead wrong about where his effect is coming from and the effect still be there and be exploitable. his device may be a step or two up the chain from where the power originates. It might not be scientifically sound but if it works it works. :)The formalized science will work itself out. it always does.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 06:05 pm
Quote
The formalized science will work itself out. it always does.

I think in this regard it is wise to look at the rest of life.  Does it usually work out?  Fact is it doesn't.

If you look at the dozens of Spacedrive schemes that have been proposed over the last 20 years, it's a striking thing that none of them work.  None.  In almost every instance, these are each individually the result of an engineer pretending to be a physicist, and slapping some dopey explanation onto what ultimately is just a delusion of grandeur.  From Dean to Searle and from Shawyer to White, ALL of these schemes are obviously WRONG when you look at the theory they propose.  Remember, White is a physicist, but he was having these delusions about QVF years before he went back to school for his PhD, and he was specifically denied the opportunity to explore his QVF model because it is crank nonsense that Rice would have nothing to do with.

And this is the way science distinguishes between pathological science, pseudo-science and the real stuff: one has to have a cogent theory that one suspects might be true.  None of these schemes has such a theory, except Woodward's M-E physics.  Woodward really does stand alone here.  All the rest fails the test for what makes real science.  This stuff is actually much closer to superstition than it is to real science.

So don't kid yourself.  Its not like you can be wrong about the thing that is supposed to explain why you would build a propellantless drive and simply stumble blindly onto a working one.  While it is always possible for such a thing to happen, so is getting hit by lightning.  The smart money, is on the real science, that isn't denying Einstein's work, or proposing to violate conservation, or dodging the authorities for fraud.  The smart money, is on only those explanations which are consistent with the science we already have great reason to believe is true, and that offers lots of opportunity to extend our basic knowledge of the universe.

The smart money is on Woodward.
Title: Re: EM Drive Developments
Post by: HMXHMX on 11/24/2014 06:15 pm
And now there is this:  http://boingboing.net/2014/11/24/the-quest-for-a-reactionless-s.html
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/24/2014 06:33 pm
And now there is this:  http://boingboing.net/2014/11/24/the-quest-for-a-reactionless-s.html
delicious :)
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 06:55 pm
Wow.  What a great piece.  For anyone interested, the second photo is about the best shot of the lab I've ever seen.  The blue box in the foreground is the Welch Duoseal 1400.  Normally it has an acoustic enclosure around it to minimize the noise in the room.  The device to the right appears to be the old U-80 load cell Jim used back before the ARC Lite went into service in 2007.  I heard he was going to try to press it back into service so he can work on more than one thing at a time.  Looks like it's up and running again.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/24/2014 07:02 pm
Indeed, building on our previous discussion on the nature of the QV itself (has weight but gravitationally repulsive, possible QV suitability as exotic matter analogue), Dr. White repeatedly hints that he is exploring this line of research in his warp experiments. He doesn't come out and say it. He is testing Qthrusters on a test bench designed to look for warped spacetime.  At the 55:30 mark on through 58:30, he gets a tough question regarding this and he shies away from that. He's essentially saying (or I am, not sure) that creating a perturbed state in the QV is changing the shape of spacetime from flat to sloped.
This is why M-E Theory and QVF are incompatible--they make contradictory claims about where inertia comes from.  The ZPF theory White's QVF model rests upon and is an extension of, stipulates that matter gets its mass from the virtual particles in the ZPF.  M-E theory stipulates that matter gets its mass from the gravitational connection between all the universe's parts but chiefly from the farthest parts as per Mach's Principle.  Both these could be wrong, but they can't both be right because they contradict one another.

When you say "mass"......to which kind of mass are you referring? I want to clearly understand what you're saying here, instead of just dismissing you. The mass generation mechanism is clearly understood, So is mass energy equivalence. Most mass is derived through QCD (chiral symmetry breaking), while the rest is Higgs mechanism and mass-energy equivalence. To my knowledge, even the QV crowd isn't trying to change the definition of mass. Are you referring to inertial mass, when you say mass then? Or are you referring to the gain in mass from a gain in energy, aka mass energy equivalence?

Quote
The real power is in the gravinertial flux--the universal wind created by and controlled by the MET.
What is "gravinertial flux"?

https://www.google.it/search?q=gravinertial+flux&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=rcs&gfe_rd=cr&ei=HopzVPPgO8WK8QeF1ICwAg#rls=org.mozilla:en-US:official&channel=rcs&q=%22gravinertial+flux%22
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 07:36 pm
In this context and for the present purpose, gravitational mass, inertial mass and inertia are all the same thing.

Mach Effects are temporary fluctuations in mass, but only in "bulk" mass since the masses of the constituent particles do not change.  The change in mass is all held in the "squishy bonds" that tie the particles together.

Whenever bulk mass is deformed, its mass changes since this strains the energy bonds between particles and these have mass.  So if it helps you can speak of it in terms of mass energy equivalence, but were you to try to change the energy in the bonds sufficient to alter the mass in the way a Mach Effect does, you'd need fantastical amounts of energy.   So speaking of mass energy equivalence could lead you astray quite quickly.  Mach Effects are not just change in the internal energy of the bonds.  To create a Mach Effect, you not only need to change the internal energy but at the same time, you need to accelerate the mass relative to the distant stars.  This then creates the 2w fluctuation based on Mach's Principle as per Woodward's derivation.

BTW, there is no way to understand this apart from Mach's Principle.  It is not "extra stuff" you don't need to understand the effect.  It is the primary enabling principle necessary for the effect to occur.  That's why I say we have strong evidence Mach is correct, because we can observe these fluctuations.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/24/2014 07:42 pm
Thank you for taking the time to explain that.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/24/2014 08:01 pm
Ron; i meant in the sense that often exploitation comes before formal understanding. For example; man was cooking megafauna long before the chemistry and combustion physics were known. shamans were whipping up bizarre herbal cocktails (both effective and ineffective) before biochemistry and pharmacological sciencewas a thing. people were blowing stuff up before chemistry was a thing. rockets were made in the near east before tsilovkosky was even conceived let alone scribbled his first equations.

you don't always need pages of proven algebra and calculus and thousands of disertations, thesis and papers to do something. sometimes things come by happy accident, or informal observation or mad tinkering.

Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 08:03 pm
His warp interferometer experiment has implicit in it that the q thruster or a similar device does warp space.

If it didn't he would have nothing to generate the warp he hopes to detect. And it has to be more than just the mass of his test article. if his interferometer was sensitive enough he could hypothetically at least measure the curvature due to the mass of atoms the beam passes by in the instrument. but it is not that sensitive.

QVF posits that any strong E field ought to produce this warp curvature.  The original interferometer was built to be able to measure something like 11 orders magnitude less curvature than his model predicted from a single capacitor.  He measured no curvature.  Then he claimed the laser was not precise enough and waited six months on a replacement, and again, no curvature.  Then he started reporting he had had "non-null results" which is fanciful at best.  If null results were possible, he had null results.  That didn't stop him claiming he had real curvature when he gave the address out at U. of AZ.

Now if you're saying he is yet again, claiming the laser was not powerful enough and he lacked resolution in the interferometer, I would just note to you he would have had to be off by more than 20 orders of magnitude for his original experiment for that to be true.  It's simply not true.  It's just yet one more example of the lack of integrity involved with the work at Eagle.  Pretty shameful really, but this is what pathological science is like.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 08:10 pm
Ron; i meant in the sense that often exploitation comes before formal understanding. For example; man was cooking megafauna long before the chemistry and combustion physics were known. shamans were whipping up bizarre herbal cocktails (both effective and ineffective) before biochemistry and pharmacological sciencewas a thing. people were blowing stuff up before chemistry was a thing. rockets were made in the near east before tsilovkosky was even conceived let alone scribbled his first equations.

you don't always need pages of proven algebra and calculus and thousands of disertations, thesis and papers to do something. sometimes things come by happy accident, or informal observation or mad tinkering.

I understand what you're saying and it is always possible to stumble onto a discovery rather than deliberately design a hypothesis or a technology.  I am just noting, that's not a safe bet.  There's no warrant for belief when the theory that predicts is obviously wrong, and continuing to cling to what we know is wrong is a hallmark of pathological science.  This does not compare to the careful science Woodward does.  It's voodoo nonsense.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/24/2014 08:16 pm
Quote
QVF posits that any strong E field ought to produce this warp curvature.

When you say QVF, do you mean quantum vacuum friction or flux or fluctuations? Probably fluctuations huh.....Just want to make sure here. I don't want to assume. I never encounter this term. Please elaborate. Do you have a link to something that says that? I'd like to read more about what you're saying.
Quote
It's simply not true.  It's just yet one more example of the lack of integrity involved with the work at Eagle.  Pretty shameful really, but this is what pathological science is like.
Can we play nice please?
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/24/2014 08:20 pm
Ron; i meant in the sense that often exploitation comes before formal understanding. For example; man was cooking megafauna long before the chemistry and combustion physics were known. shamans were whipping up bizarre herbal cocktails (both effective and ineffective) before biochemistry and pharmacological sciencewas a thing. people were blowing stuff up before chemistry was a thing. rockets were made in the near east before tsilovkosky was even conceived let alone scribbled his first equations.

you don't always need pages of proven algebra and calculus and thousands of disertations, thesis and papers to do something. sometimes things come by happy accident, or informal observation or mad tinkering.

I understand what you're saying and it is always possible to stumble onto a discovery rather than deliberately design a hypothesis or a technology.  I am just noting, that's not a safe bet.  There's no warrant for belief when the theory that predicts is obviously wrong, and continuing to cling to what we know is wrong is a hallmark of pathological science.  This does not compare to the careful science Woodward does.  It's voodoo nonsense.
I'm easy. I like Woodward. i like White. I like a long list of people you'd giggle at and give me 5 kook point's each for. I like excursions into the fringe. They don't outrage me; by turns they intrigue, amuse and embarrass me. i could name names that would cause a good deal of the people here to have explosive cranial aneurisms like in the movie "Scanners."

I don't care who does it with what device as long as someone does it and breaks us free of our current rut.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/24/2014 08:33 pm
Quoting @Ron Stahl
Quote
There's no warrant for belief when the theory that predicts is obviously wrong, and continuing to cling to what we know is wrong is a hallmark of pathological science.

Being that the work that Dr. White and Dr. Woodward are both pioneering endeavors, both of which haven't been falsified, I see no reason to have the view that somebody's theory is obviously wrong. I mean for example, I have issues with Dr. White's QVPT approach due to the thrusting against the QV and plasma language. I have serious issue with Dr. Woodward's Mach effect theory too, but I don't have the hubris to just dismiss either theories and chide them for their ideas, which are the result of continued learning and experimentation. Nobody has this all figured out yet. Why the hostility against somebody else's theory or work?

As far as White's warp theory and work. That in particular is very very early work. I'm hardly even familiar with it because I've focused on the Qthruster approach. I don't see a need to bust his chops yet because his ideas of warping space don't match yours.

This "Woodward or bust" thing has got to stop. Don't fall in love with a theory. Fall in love with the truth. Otherwise we're just going to keep feeling good about ourselves and our ideas, with our feet firmly planted eternally on Terra Firma.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/24/2014 08:40 pm


QVF posits that any strong E field ought to produce this warp curvature.  The original interferometer was built to be able to measure something like 11 orders magnitude less curvature than his model predicted from a single capacitor.  He measured no curvature.  Then he claimed the laser was not precise enough and waited six months on a replacement, and again, no curvature.  Then he started reporting he had had "non-null results" which is fanciful at best.  If null results were possible, he had null results.  That didn't stop him claiming he had real curvature when he gave the address out at U. of AZ.

Now if you're saying he is yet again, claiming the laser was not powerful enough and he lacked resolution in the interferometer, I would just note to you he would have had to be off by more than 20 orders of magnitude for his original experiment for that to be true.  It's simply not true.  It's just yet one more example of the lack of integrity involved with the work at Eagle.  Pretty shameful really, but this is what pathological science is like.

I don't think it's a case of pathological science. i think it plausible he thought his analysis methods would overcome the sensitivity issue. also his deciding to switch interferometry methods had to do with discussions and persuasion by one of his peers. at his first convention presentation he said he was going to make a purpose built test article (rather than a re-purposed q thruster) that should provide more powerful and less ambiguous warping. also it is not "now" it happened quite sometime ago maybe after his first foray into public speaking at that first convention. Also peer review formally refuted his original measurement scheme and interferometer. That would naturally lead to changing your methodology and gear.

Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 09:34 pm
Being that the work that Dr. White and Dr. Woodward are both pioneering endeavors, both of which haven't been falsified, I see no reason to have the view that somebody's theory is obviously wrong.

Just think rationally about it rather than hoping stuff will work out.  For White to be right, Einstein has to be wrong.  Now what do you think the odds of that are?

I am chasing the truth.  I have just done the diligence and know that White and Shawyer and 15 other nuts are wrong.  That stuff is all wishful thinking that has no part in science.

Now if you had some experimental evidence that Einstein was wrong, I would reconsider, but it hasn't happened in 80 years and denying conservation is even worse, IMHO.

And keep in mind, whenever these obviously wrong ideas get traction and funding, that funding comes from sources that would otherwise invest in the options that have a real possibility of working out.  Instead, Sonny has funding and Woodward does not.  That is a real scientific tragedy.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/24/2014 09:38 pm
Nordtvedt effect, is this needed for Mach effects? I see reference to it in Woodward's book.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/24/2014 09:56 pm


  Instead, Sonny has funding and Woodward does not.  That is a real scientific tragedy.

all of about 50K worth if i recall correctly. You could get that couch fishing in all the NASA break room chair cushions.

Dr Woodward has some funding from his book/SSI deals plus he has tenure. 
Title: Re: EM Drive Developments
Post by: Supergravity on 11/24/2014 10:19 pm


I am chasing the truth.  I have just done the diligence and know that White and Shawyer and 15 other nuts are wrong.  That stuff is all wishful thinking that has no part in science.


I find it incredibly interesting how you're calling White and others 'nuts', but somehow don't extend that to Woodward et al. If you've concluded that Sonny's work is pseudo-scientific nonsense, then you must also cede that Woodward is not far behind. He's just about as fringe and his work can trivially be shown to be inconsistent with Einstein.

IMO, there's only two options here. You can either take the rational and physically justified position that all of this stuff is nonsense and will never work, or you can take the position that there's some possible validity to all these fringe projects and just wait and see the results. You can't just attack certain approaches, and glorify others, despite the fact the two approaches are on the same scientific footing. Well, you can, if you have an agenda and are not interested in what actually will work.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 10:21 pm
I've never heard what sort of funding Eagle has, but with 4 full time staff and 2 interns, and hundreds of thousands in equipment, I doubt they got $50k from DARPA.  NASA provides the facilities but DARPA is paying the real bills.  By contrast, Woodward has always supplied his own funding.  And he's in his 70's with 4 forms of terminal cancer.

Title: Re: EM Drive Developments
Post by: 93143 on 11/24/2014 10:23 pm
Nordtvedt effect, is this needed for Mach effects?

No.  Quite the opposite, if I understand correctly.

his work can trivially be shown to be inconsistent with Einstein.

Then go ahead.  No one's done it so far, not that I'm aware of.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 10:26 pm


I am chasing the truth.  I have just done the diligence and know that White and Shawyer and 15 other nuts are wrong.  That stuff is all wishful thinking that has no part in science.


I find it incredibly interesting how you're calling White and others 'nuts', but somehow don't extend that to Woodward et al. If you've concluded that Sonny's work is pseudo-scientific nonsense, then you must also cede that Woodward is not far behind. He's just about as fringe and his work can trivially be shown to be inconsistent with Einstein.

IMO, there's only two options here. You can either take the rational and physically justified position that all of this stuff is nonsense and will never work, or you can take the position that there's some possible validity to all these fringe projects and just wait and see the results. You can't just attack certain approaches, and glorify others, despite the fact the two approaches are on the same scientific footing. Well, you can, if you have an agenda and are not interested in what actually will work.
I'm sorry, but are you seriously telling me I'm not entitled to make rational judgements about what is crackpot and what is not?  I need to just accept it all for whatever crazy reason?  How is that science based?  Science REQUIRES we make these judgements. 

And there is nothing inconsistent with Einstein in Woodward's work.  You simply don't know what you're talking about.
Title: Re: EM Drive Developments
Post by: Supergravity on 11/24/2014 10:38 pm
I'm sorry, but are you seriously telling me I'm not entitled to make rational judgements about what is crackpot and what is not?  I need to just accept it all for whatever crazy reason?  How is that science based?  Science REQUIRES we make these judgements.

I just find it rather humorous that you're so fervently attacking one fringe approach while in complete support of another equally fringe approach. To the scientific community, Woodward's and White's devices are considered to about as equally grounded in science (not grounded at all). All I'm saying is, it's rather easy for someone on the other team to attack you and dismiss the team you think will produce something as 'nuts'. This is not to say you have made some very valid points against Sonny's work, but I believe a similar analysis will yield the same enormous problems with Woodward's proposed device.

And there is nothing inconsistent with Einstein in Woodward's work.  You simply don't know what you're talking about.

Really? There's absolutely nothing inconsistent about Mach's principle with GR? I probably don't know what I'm talking about, but I can at least say you don't know any GR if you think Woodward's device follows from standard relativity theory.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/24/2014 10:47 pm
I remember that Mach and Einstein ended up being at odds. Mach never accepted Einstein's theory. Check for yourself.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 10:56 pm
Yes, I've had 9+ years to study all the details of the fallout between Mach and Einstein.  Anyone who wants those details can look here:

http://www.amazon.com/Machs-Principle-Newtons-Quantum-Einstein/dp/0817638237

I think the difficulty we're having with some here thinking I'm not entitled to draw distinctions is that I am actually looking at the details whereas others are suggesting blind generalities are more the method, and I'd just note that's not how science gets done.  The devil is always in the details.  You can't for example judge Woodward's work no matter your level of competency, unless you look at the work.  Same with Shawyer.  You can look at the lab data and make some judgements, but if you don't even do that, how then are these vague generalities worth the time to type?

And no, there is nothing in Woodward's work that is inconsistent with Einstein.  That does not mean it necessarily follows from Einstein alone.  It does not.  It follows from Einstein and Sciama and Mach, but if there were inconsistencies with good old Uncle Al, I would not be a proponent of M-E theory.

I would here just remind that its not as if I chose a model out of a hat.  Originally I was smitten with ZPF theory.  It was more than a year until I understood how it has consistently avoided answering the critics.  It is result of looking at all the details that I hold my position and this position is open to change as the details come in.  That is how we do science.  The QVF stuff is not science.  Call it fringe if you like but scientists draw careful distinctions based on facts, not on vague generalities and lose groups one carelessly tosses models into labeled "fringe".
Title: Re: EM Drive Developments
Post by: aceshigh on 11/24/2014 11:29 pm


I am chasing the truth.  I have just done the diligence and know that White and Shawyer and 15 other nuts are wrong.  That stuff is all wishful thinking that has no part in science.


I find it incredibly interesting how you're calling White and others 'nuts', but somehow don't extend that to Woodward et al. If you've concluded that Sonny's work is pseudo-scientific nonsense, then you must also cede that Woodward is not far behind. He's just about as fringe and his work can trivially be shown to be inconsistent with Einstein.

IMO, there's only two options here. You can either take the rational and physically justified position that all of this stuff is nonsense and will never work, or you can take the position that there's some possible validity to all these fringe projects and just wait and see the results. You can't just attack certain approaches, and glorify others, despite the fact the two approaches are on the same scientific footing. Well, you can, if you have an agenda and are not interested in what actually will work.


well, turns out it´s his opinion, based on what he knows, that Woodward's theories are fringe only to who doesn´t understand / has not really read about it.

He is entitled to consider some fringe theories less fringe than others. Otherwise, because we are investigating White's theories here and something by Woodward, we would also have to accept some stuff definitely proved to be crackpot, just because Woodward and White are in the fringe.

That´s quite a black and white universe, don´t you think so? There are clearly many shades of gray, from total crackpottery to established theories, and in the middle many stuff there may have something going on there, etc.
Title: Re: EM Drive Developments
Post by: aceshigh on 11/24/2014 11:33 pm
I remember that Mach and Einstein ended up being at odds. Mach never accepted Einstein's theory. Check for yourself.

as far as I understand, they call it Mach Effect, not Mach Theory. It´s not Mach Theory. Some say Woodward should even totally drop the Mach but then they would call it Woodward Theory and it seems Woodward doesn´t want that.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/24/2014 11:42 pm
Woodward's theory is usually referred to as Mach Effect theory, and in fact if Mach's Principle (the name coined by Einstein) is not correct, Woodward's theory is utterly mistaken.  All of his work depends upon it being correct.

Einstein repudiated Mach after Mach refused to accept Relativity theory.  Mach did believe in quite a few things that are seemingly odd today, but he was an elder scientist and everything changed with the younger generation of his time--changed around Einstein's work.  That all said, Einstein drew heavily from Mach and this is detailed in the book at the link I posted.  It's actually quite an interesting read.
Title: Re: EM Drive Developments
Post by: 93143 on 11/24/2014 11:51 pm
Woodward's theory is usually referred to as Mach Effect theory, and in fact if Mach's Principle (the name coined by Einstein) is not correct, Woodward's theory is utterly mistaken.  All of his work depends upon it being correct.

Specifically, the Sciama variant, in which inertia works the way it does because of the kind of universe we're in.  There are other interpretations of Mach's Principle that have been shown to be inconsistent with GR - and there are solutions of GR that have been shown to be inconsistent with Sciama-type Mach's principle; we just don't live in one.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/25/2014 12:33 am
Ok, from page 76 of Woodward's book:

"The principle of operation is simple. A voltage signal is applied to the FM element and
PZT actuator so that the FM element periodically gains and loses mass. A second voltage
signal is applied to the PZT actuator. The actuator voltage signal must have a component
at the power frequency of the FM voltage signal, that is, twice the frequency of the signal
applied to the FM. And it must also have a component at the FM signal frequency to
produce the acceleration of the FM required for a Mach effect to be produced. The relative
phase of the two signals is then adjusted so that, say, the PZT actuator is expanding (at the
power frequency) when the FM element is more massive and contracting when it is less
massive. The inertial reaction force that the FM element exerts on the PZT actuator is
communicated through the actuator to the RM.
Evidently, the reaction force on the RM during the expansion part of the PZT actuator
cycle will be greater than the reaction force during the contraction part of the cycle. So, the
time-averaged force on the RM will not be zero. Viewed from the “field” perspective, the
device has set up a momentum flux in the “gravinertial” field – that is, the gravitational
field understood as the cause of inertial reaction forces – coupling the FM to the chiefly
distant matter in the universe that causes the acceleration of the mechanical system
of Fig. 3.1."

Pages 17, 123, and here (flux capacitors...http://physics.fullerton.edu/~jimw/flux-cap.pdf) state that the mass being modified is inertial mass and that it is being modified by adding energy to the system.
Page 17: "When you write, as Einstein did in 1905, m = E/c2 completely
different thoughts come to mind. Instead of ogling the enormous amount of energy present
in small amounts of rest mass, you appreciate that all non-gravitational energy contributes
to the inertial masses of things."

Page 123: "The reason why the Equivalence Principle is important in this case is that it
asserts that the active gravitational, passive gravitational, and inertial masses of an object are
the same. So, if you vary one of the masses, the other masses change, too. If this aspect of the
Equivalence Principle is correct (and it is), then it is almost trivial to show that mass
variation has serious propulsive advantages."

Creating inertial mass fluctuations (and whereby also creating active gravitational and passive gravitational mass fluctuations, page 123) aside by charging capacitors.....Which I could try and argue against, but won't because there is lower hanging fruit. Do charged capacitors fall differently than discharged capacitors?......are charged vs uncharged caps easier to push around?.....Does Einstein's mass energy equivalence principle apply...yes...to extremely small effect.....the author doesn't go this route.

In a nutshell....Push while FM is heavy, pull while it is light. But on the flip side, the finite power supply that is exciting the FM is literally strapped down to the RM, reaction mass (the ship). So if the FM is gaining mass, then the power supply is losing mass by the same rationale. The entire system is being accelerated, which is required for Mach effects to occur. I see a paradox. Where is the net force? Please educate me.

Disclaimer and excerpt form copyright statement page 4:
Exempted from this legal reservation are brief excerpts in connection with reviews or
scholarly analysis.

Title: Re: EM Drive Developments
Post by: Mulletron on 11/25/2014 12:43 am
In defense of mass fluctuations though, I did find this.

http://vixra.org/pdf/1202.0038v1.pdf

Title: Re: EM Drive Developments
Post by: 93143 on 11/25/2014 12:45 am
Take with a grain of salt, because I haven't yet been able to devote enough time to fully understanding what Woodward's done, but as far as I can tell he is not talking about simple E/c² from charge/discharge when he refers to mass fluctuations.

The expected E/c² fluctuations occur, of course, as part of the device's operation, but to excite the effect in question they have to occur at the same time as some quite brisk bulk accelerations.  This, I believe, is supposed to produce much larger fluctuations in mass, which are not trivially balanced out in the rest of the local thruster system and can thus be used propulsively.

(You can see this, I think, by considering the actual equation he uses to describe the mass fluctuations, particularly the term that is always negative.  That's not something charging and discharging a capacitor would do on its own.)

Gotta work on this...  but my Ph.D. comes first, and I'm lagging...
Title: Re: EM Drive Developments
Post by: Mulletron on 11/25/2014 12:54 am
It was inertial mass....

Found this thread, lots of similar info here:
http://forum.nasaspaceflight.com/index.php?topic=17338.msg416737#msg416737

Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/25/2014 02:19 am
Nordtvedt effect, is this needed for Mach effects? I see reference to it in Woodward's book.

The Nordberg effect again.  Have I posted this one yet?

http://www.youtube.com/watch?v=NJhGfjW1-fA
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/25/2014 02:38 am
Actually i cite Dr Kramer of Washington U and some of his audience who were there asking him questions or just trying to show how gosh darned smart they were. but...

Quote
A freak wormhole opened in the fabric of the space-time continuum and carried your words far far back in time across almost infinite reaches of space to a distant galaxy where strange and warlike beings were poised on the brink of frightful interstellar battle. The two opposing leaders were meeting for the last time. A dreadful silence fell across the conference table as the commander of the Vl'Hurgs, resplendent in his black jeweled battle shorts, gazed levelly at the G'Gugvunt leader squatting opposite him in a cloud of green, sweet-smelling steam. As a million sleek and horribly beweaponed star cruisers poised to unleash electric death at his single word of command, the Vl'Hurg challenged his vile enemy to take back what it had said about his mother. The creature stirred in its sickly broiling vapour, and at that very moment the words drifted across the conference table. Unfortunately, in the Vl'hurg tongue this was the most dreadful insult imaginable, and there was nothing for it but to wage terrible war for centuries. Eventually the error was detected, but over two hundred and fifty thousand worlds, their peoples and cultures perished in the holocaust. You have destroyed most of a small galaxy. Please pick your words with greater care.

Title: Re: EM Drive Developments
Post by: ThinkerX on 11/25/2014 06:51 am
Professor McCulloch's latest:

http://physicsfromtheedge.blogspot.com/

I note that his 'MiHsC'  seems very close to the theories/effects of Woodward and Mach, if not the same thing. He talks of using MiHsC to account for tiny velocity changes in spacecraft.
Title: Re: EM Drive Developments
Post by: Lampyridae on 11/25/2014 07:37 am
Professor McCulloch's latest:

http://physicsfromtheedge.blogspot.com/

I note that his 'MiHsC'  seems very close to the theories/effects of Woodward and Mach, if not the same thing. He talks of using MiHsC to account for tiny velocity changes in spacecraft.


At a glance, no, I don't think this has anything to do with ME, other than Machian inertia. MiHsC very clearly violates the equivalence principal, whereas ME palms mass shifts off to the rest of the universe. It's an intriguing theory but I don't see how that gets a spacedrive (it's on the order 10^-10 m/s differences and the only time you notice "it" is in the mm/s flyby anomaly).

I think the LHC and a better understanding of current physics models will eventually account for these anomalies. But unfortunately no usable spacedrive would be my guess.
Title: Re: EM Drive Developments
Post by: momerathe on 11/25/2014 12:13 pm
Woodward actually has a theory. A potentially revolutionary, paradigm breaking theory, but he has one. (I remain to be convinced, but.)

I've read one of White's papers and he doesn't. He has the equivalent of "1) Quantum vacuum 2) ? ? ? 3) Profit!". It's notable it was published in an engineering journal, cause I can guarantee you that a physics journal review panel would have torn it to shreds.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 01:26 pm
One of the very few physicists at top institutions that dares write about the science-fiction of wormholes,  Kip Thorne ...
I think it's important to note that Thorne did his work with his graduate students in 1988, and the original Stargate movie that came before the TV series was in 1994.  In this instance, the fiction writers got their ideas from contemporary physics, not the other way around.  Also note that although Alcubierre published his warp mathematics in 1997 and Startrek was 30+ years in advance, Roddenberry based his notions on the best gravity physics of the 50's, meaning Dennis Sciama.  So in both these cases--warp and wormhole--we find the physicists did the work first and the fiction writers stole from them.  The fiction writers fleshed out the notions people later assumed were just fiction and lets face it, they're full of drama as result, but the really visionary stuff came first from the physicists like Kip Thorne.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 01:32 pm
Actually i cite Dr Kramer of Washington U and some of his audience who were there asking him questions or just trying to show how gosh darned smart they were. but...

Quote
A freak wormhole opened in the fabric of the space-time continuum and carried your words far far back in time across almost infinite reaches of space to a distant galaxy where strange and warlike beings were poised on the brink of frightful interstellar battle. The two opposing leaders were meeting for the last time. A dreadful silence fell across the conference table as the commander of the Vl'Hurgs, resplendent in his black jeweled battle shorts, gazed levelly at the G'Gugvunt leader squatting opposite him in a cloud of green, sweet-smelling steam. As a million sleek and horribly beweaponed star cruisers poised to unleash electric death at his single word of command, the Vl'Hurg challenged his vile enemy to take back what it had said about his mother. The creature stirred in its sickly broiling vapour, and at that very moment the words drifted across the conference table. Unfortunately, in the Vl'hurg tongue this was the most dreadful insult imaginable, and there was nothing for it but to wage terrible war for centuries. Eventually the error was detected, but over two hundred and fifty thousand worlds, their peoples and cultures perished in the holocaust. You have destroyed most of a small galaxy. Please pick your words with greater care.

It's insightful to note Cramer is famous not only for his fiction published in Analog, but especially for his Transactional Interpretation of QM, and that this theory fits Woodward's remarkably well.  These both make judicious use of Wheeler-Feynman Absorber Theory with both advanced and retarded waves .  I'm told Cramer has actually published the authoritative paper on how to steer a wormhole, but I've never seen the paper.  I know he wrote the forward in Woodward's book, but I have yet to dive into the dynamics of what it takes to steer a wormhole generator.  If anyone finds that work by Cramer online, please do share.  I'd love to have access.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 01:35 pm
The "book" which one of our notable thread contributors keeps insisting upon not buying, contains many "careful" explanations of the Mach Effect, none of which seem to hold water.  Or rather:  None of which seem to move mass.
One wonders why it would seem that way to anyone given so many years of success in the lab.  What are you referring to?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 01:37 pm
"QVF" stands for "Quantum Vacuum Fluctuations".  That's the title of Dr. White's model, which is derived from the Haishe, Putthoff, Rueda ZPF model that was something like 15 years before it.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 01:47 pm
In a nutshell....Push while FM is heavy, pull while it is light. But on the flip side, the finite power supply that is exciting the FM is literally strapped down to the RM, reaction mass (the ship). So if the FM is gaining mass, then the power supply is losing mass by the same rationale.

This is very close but not quite right.  The thing that is losing mass when the fluctuating or active mass gains mass, is the rest of the universe.  The reaction mass is just the thing the active mass pushes off of.  The source of the gravinertial flux of the universe, is the mass of the universe itself.  So it is accurate to say, that when a gravinertial transistor like a Mach-Effect Thruster (MET) harvests momentum from the gravinertial field, it is causing the universe to accelerate in its expansion and hastens the arrow of time (entropy).  This is in fact why Tom Mayhoood, Woodward's grad student back in the 90's, put the sign on the lab door reading "Tomorrow's Momentum Today".  This is accurate to the physical theory.

Though Woodward has never weighed in on the issue so far as I'm aware, i would just note this could be an explanation for Dark Energy, or whatever force it is that is causing the observed acceleration in the expansion of the universe.   We've known since 1997, that instead of the universe expanding ever more slowly as it fights its own gravity as we'd expect, the universe is accelerating in its expansion, and this is the effect we ought to observe from LOTS of gravinertial harvesting from Mach-Effect devices.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 01:52 pm
Woodward actually has a theory. A potentially revolutionary, paradigm breaking theory, but he has one. ...

My theory is that his theory is incomplete, unsubstantiated, missing important details, anc continually changing.

It was first published in Foundations of Physics in 1993 I think?  Hasn't changed since then.  Not sure why you'd assume the worst of something you haven't read.  Woodward's theory is peer reviewed for more than 20 years.  He points out where it is incomplete and is not bashful about it, but he is after space propulsion, not theory.

It's worth noting Woodward both starts and ends his book pointing out what is incomplete and what needs to happen in the work in both the short and long term future.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/25/2014 02:16 pm



It's insightful to note Cramer is famous not only for his fiction published in Analog, but especially for his Transactional Interpretation of QM, and that this theory fits Woodward's remarkably well.  These both make judicious use of Wheeler-Feynman Absorber Theory with both advanced and retarded waves .  I'm told Cramer has actually published the authoritative paper on how to steer a wormhole, but I've never seen the paper.  I know he wrote the forward in Woodward's book, but I have yet to dive into the dynamics of what it takes to steer a wormhole generator.  If anyone finds that work by Cramer online, please do share.  I'd love to have access.

I posted a video lecture by Kramer. i could find the link again if you are interested. Basically; it's the very thing that is supposed to destroy traversible wormholes: Cosmic Back Reaction.

According to Dr. Kramer it's actually quite useful for maintaining a wormhole, resizing a wormhole and driving a wormhole aperture around like a boss. On top of that, it actually allows you to do some awesome things other than merely bypassing FTL restrictions E.G; you could make a monopole out of a wormhole and you can use it to make some exotic matter for free.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 02:29 pm
I posted a video lecture by Kramer. I could find the link again if you are interested.
I'm very interested.  I've been interested in this for years but never tracked it down.  I know Woodward and Cramer are friends of many years.  Woodward actually presented at Cramer's birthday party (was it 75th?).  Sounds like it was a fun gathering.
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/25/2014 02:31 pm
Quote
Not sure why you'd assume the worst of something you haven't read.

When you tell the truth about what I have read, then you can address my opinions on the matter.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/25/2014 02:32 pm
I posted a video lecture by Kramer. I could find the link again if you are interested.
I'm very interested.  I've been interested in this for years but never tracked it down.  I know Woodward and Cramer are friends of many years.  Woodward actually presented at Cramer's birthday party (was it 75th?).  Sounds like it was a fun gathering.
 

here is the one i am talking about. it discusses the topic and if lucky you should catch something on the screen you can web search for the papers you are looking for from.

https://www.youtube.com/watch?v=PZG1LK0KjKs
Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/25/2014 02:33 pm
...[it actually allows you to do some awesome things other than merely bypassing FTL restrictions E.G; you could make a monopole out of a wormhole and you can use it to make some exotic matter for free.

I move mountains by faith and faith alone too.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/25/2014 02:35 pm
lol. i can take as given *you'll* never invent a wormhole drive then. :P
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/25/2014 03:14 pm
Watched it again. Paul Davies (in the audience at the very end) is a real party pooper. :(
Title: Re: EM Drive Developments
Post by: Rodal on 11/25/2014 03:44 pm
Watched it again. Paul Davies (in the audience at the very end) is a real party pooper. :(
It is very revealing and very telling that Cramer himself (when prompted by a question from the audience regarding solving Einstein's equations with the proper boundary conditions) admits (at 34:00 minutes) that he "has done no mathematics at all on this, and it is just a handwaving idea"
He mentions towards the end of this video Woodward's wormhole term as something one would consider as if "grasping at straws" (Cramer's own words).


https://www.youtube.com/watch?v=PZG1LK0KjKs#t=2049
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/25/2014 03:53 pm
i wouldn't put too much stock in that. Cramer is published on this sort of thing. remember what prompted me to post the video was someone looking for some of Cramer's papers.
Title: Re: EM Drive Developments
Post by: Rodal on 11/25/2014 03:59 pm
i wouldn't put too much stock in that. Cramer is published on this sort of thing. remember what prompted me to post the video was someone looking for some of Cramer's papers.
When Kip Thorne goes out of his way to write (a couple of days ago) that he thinks that it is very unlikely for wormholes to ever exist, you don't put too much stock in Prof. Thorne's latest statement?

When Prof. Cramer states (in the video you posted) that he has done no math on this, and it is just a handwaving idea, you also don't put too much stock in that?

 

Quote from:  Groucho Marx
Who are you going to believe, me or your own eyes?
   :)
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 04:35 pm
When Kip Thorne goes out of his way to write (a couple of days ago) that he thinks that it is very unlikely for wormholes to ever exist, you don't put too much stock in Prof. Thorne's latest statement.

That's several times in a row now you've mischaracterized statements on this issue.  First of all, Cramer did not say no calculations had been done on topology change, he said he had not done any and in fact, that is not his field.  (Even if it were, he is retired.)  He also did not say Woodward's work was grasping at straws as you suggest, but rather he said if you want to grasp at straws, he recommends Woodward's work.  You've really twisted Cramer's words in a torturous manner here.  You're also mischaracterizing and misrepresenting Kip Thorne's words.  He did not say he thinks it unlikely wormholes ever exist.  He said he doubts they are natural.  Actually from the way he made the stateent it sounds as if pressed, he does believe in wormholes.  Somehow you have that all twisted around and one wants to ask why all three of these misrepresentations?  Do you have a presuppositional bias about wormholes?
Title: Re: EM Drive Developments
Post by: Rodal on 11/25/2014 04:48 pm
When Kip Thorne goes out of his way to write (a couple of days ago) that he thinks that it is very unlikely for wormholes to ever exist, you don't put too much stock in Prof. Thorne's latest statement.

That's several times in a row now you've mischaracterized statements on this issue.  First of all, Cramer did not say no calculations had been done on topology change, he said he had not done any and in fact, that is not his field.  (Even if it were, he is retired.)  He also did not say Woodward's work was grasping at straws as you suggest, but rather he said if you want to grasp at straws, he recommends Woodward's work.  You've really twisted Cramer's words in a torturous manner here.  You're also mischaracterizing and misrepresenting Kip Thorne's words.  He did not say he thinks it unlikely wormholes ever exist.  He said he doubts they are natural.  Actually from the way he made the stateent it sounds as if pressed, he does believe in wormholes.  Somehow you have that all twisted around and one wants to ask why all three of these misrepresentations?  Do you have a presuppositional bias about wormholes?
Mr. Stahl, the readers will determine who is "mischaracterizing" anything or who has an agenda here.  I invite you to reconsider who has actually reacted and posted in such a partisan manner.


Concerning Prof. Cramer, I have referred the readers to the video where Cramer makes his statement.

Concerning Prof. Thorne, I reproduce again what I posted concerning what Prof. Thorne wrote (where I reproduced entirely Prof. Thorne's complete statement):


One of the very few physicists at top institutions that dares write about the science-fiction of wormholes,  Kip Thorne (Professor of Theoretical Physics, Emeritus at CalTech) wrote the following letter to the Wall Street Journal (this weekend's edition, page A12,  November 22/23 2014), to clarify some pretense (triggered by the movie "Interstellar") about the feasibility of whether our human civilization could actually travel through wormholes to reach planets in other stars: (bold added for emphasis)

Quote from: Prof. Kip Thorne, CalTech
Regarding the Weekend Interview on Nov. 15 by Sohrab Ahmari ("Finding our place in the stars"), in which I was interviewed:

We physicists have tried to figure out what the laws of physics say about wormholes.  We don't yet have an absolutely firm answer, but it appears very likely that the physical laws prevent wormholes from ever existing, and that if wormholes can exist, they cannot occur naturally - they must be created by some very advanced civilization, such as the bulk beings in "Interstellar".




Prof. Thorne has been clear that << it appears very likely that the physical laws prevent wormholes from ever existing>>.  That's why he went through the trouble to write the letter to the WSJ this weekend: to make it clear that it is his present opinion that naturally occurring wormholes are very unlikely to ever exist. Ditto in his recent book (quoted above).  He has investigated "natural occurring wormholes" and he has concluded that they are unstable: if they were ever to form they would naturally collapse almost instantaneously.

Here is a direct link to Prof. Thorne's letter:

http://online.wsj.com/articles/the-laws-of-physics-regarding-wormholes-1416606575
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 05:37 pm
Well perhaps we misunderstood each other.

I apparently mistook you to be championing this skeptical pseudo-scientific attitude that scoffs right out of the gate at anything dramatic or promising.  I was subject to this sort of sickness as a high school student when both my first and second year physics teachers told us on no uncertain terms that journeying outside our planetary system would never happen because the distances are too great, and the average man journeying off the planet would never happen because the expense was too great.  Of course it's since 1997 we've known both these assertions are wrong.

Now if you want to get Kip's view of this issue, I suggest look here:

http://time.com/3602525/christopher-nolan-physics-interstellar-kip-thorne/

time index around 6:20 and Kip's answer about 7:15.  The interviewer asks specifically if Kip is concerned about teaching people things like warp drive are possible, and what we find is Kip recommending humility, and noting that physicists think one way and later find they've had it all backward.  "You believe something and then discover you were wrong, every day."  He never answers the question directly.  I find that fascinating.

Title: Re: EM Drive Developments
Post by: Rodal on 11/25/2014 06:24 pm
The purpose in posting Prof. Thorne's and Cramer's statements is to promote discussion: why and what are the reasons for which they decided to make these statements?.  The scientific attitude has always been to question everything.   Scientists are in search of the truth.  Neither Galileo, Einstein, Tsiolkowvsky, etc. were demoralized by discerning questions.  When Paul Davies brings up Hawking's cosmological protection principle (that would prevent the formation of wormholes), it should not be viewed as being a party pooper: it should be viewed as an intelligent question to search whether the presenter has a good answer for it.  If the presenter has a good answer, it benefits the whole audience.  It is to the benefit of the scientist to ask himself/herself, and to be asked by others, discerning questions. 

It was to the benefit of Amundsen to be well-prepared for the South Pole expedition, and it was to Scott's detriment to not be as well prepared and to have embarked without as much discerning planning.
Title: Re: EM Drive Developments
Post by: SteveKelsey on 11/25/2014 06:45 pm
This might help the debate

http://thelifeofpsi.com/wp-content/uploads/2014/09/Hawking-1992.pdf

The conclusion has enough in it to reinforce the improbability of wormholes forming without new physics.
Title: Re: EM Drive Developments
Post by: Rodal on 11/25/2014 07:21 pm
NASA'S MICROWAVE PROPELLANT-LESS THRUSTER ANOMALOUS RESULTS:
CONSIDERATION OF A THERMO-MECHANICAL EFFECT


J. J. Rodal, Ph.D.

ABSTRACT:

It has been argued that the anomalous results found by NASA's Brady et.al for microwave cavities (that supposedly act as a propellant-less thruster) cannot be due to thermal effects because a) the temperature increase would need to amply exceed several degrees C to be explained by thermal effects and b) thermal effects take place too slowly (minutes) and cannot explain the impulsive response of the thrust pendulum exhibiting a rise to full amplitude in half the pendulum's period (rise to full amplitude in little over 2 seconds).

These (analytically unsupported) arguments are invalidated here: a thermo-mechanical effect (thermal buckling) is shown that occurs in less than 1 second (for the copper thickness that has been argued as employed for the microwave cavity), with a temperature increase of a degree C or less and that results in forces of the same magnitude (microNewtons) as reportedly measured by NASA.


1. CALCULATION OF TEMPERATURE INCREASE

Considering the copper thickness at the big circular flat base of Brady et,al.'s truncated cone to be thermally insulated (by the printed circuit board material) at the surface z=0 and be subject to heat (energy per unit time, per unit area) "heatFlux" at the surface z=thickness, the complete transient solution for the temperature increase is (where "time" is time in seconds) [Carslaw, H. S., and J. C. Jaeger]:

deltaT=(heatFlux*thickness/thermalConductivity)*( (time/fourierTime) + ((1/2)*((z/thickness)^2) - (1/6)) + temperatureSum

where:

temperatureSum=(heatFlux*thickness/thermalConductivity)*(-(2/(Pi^2))*NSum[(((-1)^n)/(n^2))*(Exp[- (time/fourierTime)*((n*Pi)^2)])*Cos[n*Pi*(z /thickness)], {n, 1, Infinity}])

fourierTime = (thickness^2)/thermalDiffusivity

thermalDiffusivity = thermalConductivity/(density*heatcapacityperunitmass)

For copper, we have the following material properties:

density=8940  kg/(m^3);
thermalConductivity=390  (J/s)/(m*degC);
heatcapacityperunitmass=385  J/(kg*degC);

therefore:

thermalDiffusivity = 0.00011331 m^2/s

fourierTime = 8825.38 thickness^2  s /m^2

So we see that steady-state conditions occur very fast due to the very small thickness. 
For example, for thickness = (0.025 inch) * (25.4/1000 m/inch) = 0.635 mm

fourierTime = 0.00355862 s

Therefore the temperatureSum term is negligible for time responses exceeding milliseconds.  The term ((1/2)*((z/thickness)^2) - (1/6)) is also negligible in comparison with (time/fourierTime), so essentially we are left with

deltaT ~ (heatFlux*thickness/thermalConductivity)*(time/fourierTime)

                       ~ heatFlux*time / (density*heatcapacityperunitmass*thickness)

For copper,

density*heatcapacityperunitmass = heatcapacityperunitvolume = 8940*385 (* J/((m^3) * degC)*)
                                                 = (3441900 J)/(degC m^3)

hence,

deltaT ~ (heatFlux* time)/(3441900 thickness) degC m^3/ J


where heatFlux has units of W/m^2, thickness in meters and time in seconds.

Calculation of the Heat Flux:

For the transverse electric mode TE012 (p. 18, Table 2. Tapered Cavity Testing: Summary of Results) of the "Anomalous Thrust..." paper by Brady et.al., the Input Power was 2.6 Watts.

The input power gets converted into heat (by eddy-currents from the magnetic field) and since for the transverse electric mode TE012 only the axial magnetic field is non-zero in contact with the big diameter base (the small end was insulated by a polymer dielectric), the heat flux is:

heatFlux = InputPower /FluxedArea = 2.6 W /FluxedArea

where the FluxedArea is:

(Pi/4)*( BigDiameter^2 ) / (heatedDiameterRatio^2)

where

heatedDiameterRatio = BigDiameter / DiameterOfAreaExperiencingHeatFlux

accounts for the fact that the magnetic flux in mode TE012 contacts only a fraction of the entire circular areas at the ends of the truncated cone.

heatFlux = InputPower * (heatedDiameterRatio^2) / ( (Pi/4)*( BigDiameter^2 ) )

and substituting this into the expression for deltaT

deltaT = heatFlux*time/(density*heatcapacityperunitmass*thickness)
            =InputPower*(heatedDiameterRatio^2)*time /
                                                     ( (Pi/4)*(BigDiameter^2)*density*heatcapacityperunitmass*thickness )

For example, the TE012 truncated cone input power and using the copper material properties:

InputPower=2.6 J/s
density=8940  kg/(m^3);
heatcapacityperunitmass=385  J/(kg*degC);

deltaT =InputPower*(heatedDiameterRatio^2)*time /
                                                     ( (Pi/4)*(BigDiameter^2)*density*heatcapacityperunitmass*thickness )
           =(( heatedDiameterRatio^2) * time)/( 1.03972*10^6 * (BigDiameter^2) * thickness)  degC m^3 / s


2. CALCULATION OF TEMPERATURE AND TIME AT WHICH BUCKLING OCCURS

The thermal (membrane) stress of a restrained plate produced by a temperature difference "deltaT" is simply:

sigma = (ElasticModulus/(1- poissonRatio))*alpha*deltaT

where alpha is the coefficient of thermal expansion, ElasticModulus is the modulus of elasticity and poissonRatio is the Poisson's ratio  of the plate's material.  (See for example Noda et.al p.414 or Roark, top of page.583, Nr. 2).

From Timoshenko (p. 391 Eq. 9.16) or Roark (Table 35, Nr. 11, p.554, referring to Timoshenko's solution), the buckling (membrane) stress of a simply supported circular plate is:

sigma = 0.35*((thickness/plateRadius)^2)*(ElasticModulus/(1-poissonRatio^2))

and since plateRadius = BigDiameter/2

sigma = 1.4*((thickness/ BigDiameter)^2)*(ElasticModulus/(1-poissonRatio^2))

Therefore, equating both expressions the temperature difference that will produce buckling of the circular plate is:

bucklingdeltaT =((thickness/ BigDiameter)^2)*( 1.4/( alpha *(1+poissonRatio)))

For copper:

alpha = 17*10^(-6) 1/degC
poissonRatio=0.3

therefore, for a circular copper plate, the temperature difference that will produce buckling is only related to the square of the ratio of the thickness to the diameter of the circular plate as follows:

bucklingdeltaT =((thickness/ BigDiameter)^2)*63348.4 degC

For example, for

thickness = (0.025 inch) * (25.4/1000 m/inch) = 0.635 mm
BigDiameter =0.2793 m = 10.996 in (aero's estimate)

bucklingdeltaT =0.33 degC

So, very low temperature differences between the plate (and the rest of the truncated cone) are required to buckle it.  The thinner the plate, the lower the temperature difference (between the plate and the rest of the truncated cone) that is required to buckle it.

Equating the expression for the deltaT required for buckling with the deltaT expression obtained at the end of section 1, we have

InputPower*(heatedDiameterRatio^2)*time/ ((Pi/4)*(BigDiameter^2)*density*heatcapacityperunitmass*thickness )
=((thickness/ BigDiameter)^2)*( 1.4/( alpha *(1+poissonRatio)))

therefore the time at which buckling occurs is:

bucklingtime=1.4*(Pi/4)*density*heatcapacityperunitmass*(thickness^3)     
                             /  (InputPower*(heatedDiameterRatio^2)*alpha*(1+poissonRatio)))

For the following (copper) material properties

density=8940  kg/(m^3);
heatcapacityperunitmass=385  J/(kg*degC);
alpha = 17*10^(-6) 1/degC
poissonRatio=0.3

we get the following time at which buckling occurs:

bucklingtime =(5553.17*thickness) ^3 /(heatedDiameterRatio^2 InputPower)   J/m^3

and for the InputPower=2.6 J/s

bucklingtime =(4038.47*thickness) ^3 /heatedDiameterRatio^2   s/m^3

For example, for

thickness = (0.020 inch) * (25.4/1000 m/inch) = 0.508 mm
heatedDiameterRatio =4

bucklingtime = 0.54 seconds


3. CALCULATION OF BUCKLING AND POST-BUCKLING DISPLACEMENT

The originally flat, circular plate, simply supported at its edges, under in-plane stress, buckles into a stress-free spherical shape. 

Denote by xbar and ybar the horizontal rectangular cartesian coordinates and by zbar the vertical cartesian coordinates of the spherical buckled and postbuckled state centered at the origin of these coordinates, such that

xbar^2 + ybar^2 + zbar^2 = R^2

where R, a function of time, R(time), is the radius of curvature of the buckled and postbuckled shape.

Define a new set of rectangular cartesian coordinates with the origin vertically displaced upwards  such that w(x,y) is the vertical coordinate displacement of the buckled shape with respect to the original flat configuration:

x=xbar
y=ybar
w(x,y) = zbar - (R - wmax)

Such that

w(0,0) = wmax

and the boundary conditions:

w(BigDiameter/2,0)=0
w(0,BigDiameter/2)=0

Then,

x^2 + y^2 + (w(x,y) - wmax  + R)^2 = R^2

w(x,y) = wmax + Sqrt[ R^2 - x^2 - y^2 ] - R

w(x,y) = wmax + R (Sqrt[ 1 - (x/R)^2 -( y/R)^2 ] - 1)

which satisfies w(0,0) = wmax identically.  While the other two equalities give

w(BigDiameter/2,0)= wmax + R (Sqrt[ 1 - ((BigDiameter/2)/R)^2 ] - 1) = 0

w(0,BigDiameter/2)= wmax + R (Sqrt[ 1 - ((BigDiameter/2)/R)^2 ] - 1) = 0

giving:

wmax = R (1 - Sqrt[ 1 - ((BigDiameter/2)/R)^2 ] )

and hence

w(x,y) = R (Sqrt[ 1 - (x/R)^2 -( y/R)^2 ]  - Sqrt[ 1 - ((BigDiameter/2)/R)^2 ])

The thermal strain is simply

epsilonT = alpha *deltaT

where alpha is the coefficient of thermal expansion and deltaT the temperature difference.  In the stress-free buckled configuration, this strain must be equal to the change in length divided by the original length:

epsilonT =( theta*R - (BigDiameter/2)) / (BigDiameter/2)
                = alpha *deltaT

where theta is the angle, measured at the origin of the xbar, ybar, zbar coodinated system, measured between the vertical coordinate zbar and the simply supported ends.  Therefore, this angle theta is:

theta = (1+ alpha*deltaT) * (BigDiameter/(2*R))

Also, from the definition of the angle theta, we know:

Sin[theta] = (BigDiameter/(2*R))

Which gives the following transcendental equation for the radius of curvature R of the buckled and post-buckled shape:

Sin[(1+ alpha*deltaT) * (BigDiameter/(2*R))] = (BigDiameter/(2*R))

A solution of this transcendental  equation for arbitrarily large deformations would involve Elliptic functions (as in the Elastica solution), but since the coefficient of thermal expansion of copper is very small (alpha = 17 *10^-6  1/degC) and the temperature differences involved in this problem are small (deltaT ~ a few degrees C), it is known that

(1+ alpha*deltaT) ~ 1

such that

Sin[(1+ alpha*deltaT) * (BigDiameter/(2*R))] ~ (BigDiameter/(2*R))

Therefore we can use perturbation solution of the transcendental equation, by expanding the sine of theta as follows:


[(1+ alpha*deltaT) * (BigDiameter/(2*R))] - ( [(1+ alpha*deltaT) * (BigDiameter/(2*R))]^3)/3! + ... = (BigDiameter/(2*R))

giving:

alpha*deltaT - ( (BigDiameter/(2*R))^2) *( (1+alpha*deltaT)^3) /6  = 0

and solving for R:

R = (BigDiameter/2) * ((1+alpha*deltaT)^(3/2)) / Sqrt[6*alpha*deltaT]
   = (BigDiameter/2) / Sqrt[6*alpha*deltaT]

Therefore

w(x,y) = ( (BigDiameter/2) / Sqrt[6*alpha*deltaT] ) * (Sqrt[ 1 - 6*alpha*deltaT *(x/((BigDiameter/2))^2 -6*alpha*deltaT *( y/((BigDiameter/2))^2 ]  - Sqrt[ 1 - 6*alpha*deltaT ])

Expanding the square root terms, since (1+ alpha*deltaT) ~ 1, gives

w(x,y) = ((BigDiameter/4) * Sqrt[6*alpha*deltaT] ) * (1 - (x/(BigDiameter/2))^2 - ( y/(BigDiameter/2))^2)

therefore the maximum displacement of the buckled and postbuckled shape, occurring at the center of the circular plate (x=y=0) is given by:

w(0,0) = wmax = ((BigDiameter/4) * Sqrt[6*alpha*deltaT] )

and we check again, that the boundary conditions w(BigDiameter/2,0)=0 and w(0,BigDiameter/2)=0 are satisfied by this expression.

Recalling the previously derived expression for the buckling deltaT:

bucklingdeltaT =((thickness/ BigDiameter)^2)*( 1.4/( alpha *(1+poissonRatio)))

it follows that the buckling displacement at the center of the plate is:

wmaxBuckling=((BigDiameter/4)*Sqrt[6*alpha*(((thickness/BigDiameter)^2)*(1.4/
                             (alpha*(1+poissonRatio))))] )

wmaxBuckling = 0.724569* thickness / Sqrt[1+poissonRatio]

wBuckling(x,y)=0.724569*thickness*(1-(x/(BigDiameter/2))^2-(y/(BigDiameter/2))^2)/     Sqrt[1+poissonRatio]

and for poissonRatio = 0.3

wmaxBuckling = 0.635489 * thickness

wBuckling(x,y) = 0.635489 *thickness*(1-(x/(BigDiameter/2))^2-(y/(BigDiameter/2))^2)

So, the buckling displacement at the center of the plate is only a function of the thickness of the circular plate: it does not depend on the diameter of the plate, the coefficient of thermal expansion, or the temperature difference.

Now I derive the  postbuckling displacement at the center of the plate, which is a function of time. In the previously derived expression:

w(0,0) = wmax = ((BigDiameter/4) * Sqrt[6*alpha*deltaT] )

if we substitute the previously derived expression for deltaT

deltaT =InputPower*(heatedDiameterRatio^2)*time /
                                                     ( (Pi/4)*(BigDiameter^2)*density*heatcapacityperunitmass*thickness )

wmax = ((BigDiameter/4) * Sqrt[6*alpha*( InputPower*(heatedDiameterRatio^2)*time /
                  ( (Pi/4)*(BigDiameter^2)*density*heatcapacityperunitmass*thickness ))] )

wmax=heatedDiameterRatio*Sqrt[((3/(2*Pi))*alpha*InputPower*time)/
(density*heatcapacityperunitmass*thickness)]

w(x,y,time)= heatedDiameterRatio*Sqrt[((3/(2*Pi))*alpha*InputPower*time)/
                      (density*heatcapacityperunitmass*thickness)]
                       *(1-(x/(BigDiameter/2))^2-(y/(BigDiameter/2))^2)

For the following (copper) material properties and InputPower:

density=8940  kg/(m^3);
heatcapacityperunitmass=385  J/(kg*degC);
alpha = 17*10^(-6) 1/degC;
InputPower=2.6 J/s;

this give the postbuckled displacement as a function of time, plate thickness and heated diameter ratio:(for input power=2.6 watts)

wmax=heatedDiameterRatio*Sqrt[time)/thickness]/403847. m*( (m/s)^(1/2))

w(x,y,time)=heatedDiameterRatio*Sqrt[time)/thickness]*(1/403847)
                   *(1-(x/(BigDiameter/2))^2-(y/(BigDiameter/2))^2)


4. CALCULATION OF POST-BUCKLING SPEED, ACCELERATION AND INERTIAL FORCE RESULTANT

Similarly we can compute the partial derivatives of the postbuckled displacement with respect to time: the speed and the acceleration:

dw/dt=(1/2) heatedDiameterRatio*Sqrt[((3/(2*Pi))*alpha*InputPower)/
                      (density*heatcapacityperunitmass*thickness*time)]
                       *(1-*x/(BigDiameter/2))^2-(y/(BigDiameter/2))^2)


d^2w/dt^2=(-1/4) heatedDiameterRatio*Sqrt[((3/(2*Pi))*alpha*InputPower)/
                      (density*heatcapacityperunitmass*thickness*(time^3))]
                       *(1-(x/(BigDiameter/2))^2-(y/(BigDiameter/2))^2)


which for

density=8940  kg/(m^3);
heatcapacityperunitmass=385  J/(kg*degC);
alpha = 17*10^(-6) 1/degC;
InputPower=2.6 J/s;

gives

dw/dt=(heatedDiameterRatio/(807695. *Sqrt[time*thickness]))
              *(1-(x/(BigDiameter/2))^2-(y/(BigDiameter/2))^2)    m/s  (s*m)^(1/2)

d^2w/dt^2= - (heatedDiameterRatio/((1.61539*10^6) *Sqrt[thickness*time^3]))
              *(1-(x/(BigDiameter/2))^2-(y/(BigDiameter/2))^2)    m/s^2  ((s^3)*m)^(1/2)

The postbuckling speed decreases with time, inversely proportionally to the square root of time.  The postbuckling acceleration decreases with time as the inverse of time^(3/2).

To compute the inertial force resultant, we need to integrate the acceleration across the whole surface of the circular plate.  To do this is most convenient to express the acceleration in polar coordinates r and phi (where r is the radial in-plane polar coordinate measured from the center of the plate and phi is the in-plane azimuthal polar angle) instead of the rectangular coordinates, using the transformation x=r*Cos[phi] and y=r*Sin[phi]:


d^2w/dt^2=(-1/4) heatedDiameterRatio*Sqrt[((3/(2*Pi))*alpha*InputPower)/
                      (density*heatcapacityperunitmass*thickness*(time^3))]
                        *(1-(r*Cos[phi]/(BigDiameter/2))^2-(r*Sin[phi]/(BigDiameter/2))^2)
                          m/s^2        ((s^3)*m)^(1/2)

                     = (-1/4) heatedDiameterRatio*Sqrt[((3/(2*Pi))*alpha*InputPower)/
                         (density*heatcapacityperunitmass*thickness*(time^3))]
                        *(1-(r/(BigDiameter/2))^2)    m/s^2        ((s^3)*m)^(1/2)



inertialReaction=density*thickness*Integrate[r*d^2w/dt^2,{r,0 BigDiameter/2},{phi,0,2*Pi}}]

                             =(-1/4) heatedDiameterRatio*Sqrt[((3/(2*Pi))*alpha*InputPower)/
                               (density*heatcapacityperunitmass*thickness*(time^3))]
                               *density* thickness *( BigDiameter^2)*Pi/8

                             =(-1/32)*heatedDiameterRatio*(BigDiameter^2)
                               *Sqrt[((3Pi/2)*density*alpha*InputPower* thickness)/
                                 (heatcapacityperunitmass *(time^3))]

Essentially, due to the boundary conditions (no out-of-plane deflection at the edges of the circular plate) the simply-supported circular plate has half the inertia as if the whole plate accelerated with the same acceleration of the center of the plate.
                               

For

density=8940  kg/(m^3);
heatcapacityperunitmass=385  J/(kg*degC);
alpha = 17*10^(-6) 1/degC;
InputPower=2.6 J/s;


inertialReaction=-(((BigDiameter^2)*heatedDiameterRatio*Sqrt[thickness /( time^3)])/ 460.129) 
                               N (s^(3/2) m^(-5/2) )

The inertial reaction force at buckling is obtained by replacing the expression for the bucklingtime:

bucklingtime=1.4*(Pi/4)*density*heatcapacityperunitmass*(thickness^3)     
                             /  (InputPower*(heatedDiameterRatio^2)*alpha*(1+poissonRatio)))

inertialReaction = - (((alpha^2) (InputPower^2) (BigDiameter^2) (heatedDiameterRatio^4)
               Sqrt[((1 +poissonRatio)^3)] )/(16.9964 *density*(heatcapacityperunitmass^2)*thickness^4))

and for

density=8940  kg/(m^3);
heatcapacityperunitmass=385  J/(kg*degC);
alpha = 17*10^(-6) 1/degC;
InputPower=2.6 J/s;
poissonRatio=0.3;

inertialReaction = - (BigDiameter^2)* (heatedDiameterRatio/( 1669.99*thickness) )^4   microN m^2

The inertial reaction force is a very nonlinear function of the plate thickness (to the fourth power ! )

5. EXAMPLES: THICKNESS, BUCKLING TIME AND INERTIAL FORCE RESULTANT

For:

BigDiameter =0.2793 m = 10.996 in (aero's estimate)

inertialReaction = -  (heatedDiameterRatio/( 3159.94*thickness) )^4   microN m^4

So, for example we can compute the following table:

thickness (in)/ (mm)  Buckling Time (sec)  heatedDiameterRatio  Buckling reaction Force (microNewtons)

0.027/ 0.6858             0.590120                6                                       -58.7626
0.023/ 0.5842             0.525285                5                                       -53.8171
0.018/ 0.4572             0.393413                4                                       -58.7626
0.014/ 0.3556             0.329074                3                                       -50.8071
0.009/ 0.2286             0.196707                2                                       -58.7626
0.0045/ 0.1143           0.0983534              1                                       -58.7626

For:

BigDiameter =0.397 m = 15.63 in (Fornaro's estimate)

inertialReaction = -  (heatedDiameterRatio/( 2650.44*thickness) )^4   microN m^4

So, for example we can compute the following table:

thickness (in)/ (mm)  Buckling Time (sec)  heatedDiameterRatio  Buckling reaction Force (microNewtons)

0.033/ 0.8382             1.07743                  6                                       -53.2034
0.027/ 0.6858             0.849773                5                                       -57.2553
0.022/ 0.5588             0.71829                  4                                       -53.2034
0.016/ 0.4064             0.491212                3                                       -60.1722
0.011/ 0.2794             0.359145                2                                       -53.2034
0.0055/0.1397            0.179572                1                                       -53.2034

6. CONCLUSIONS

I have shown that a thermo-mechanical effect (thermal buckling of the base of the truncated cone) can account for some of the "anomalous" results reported by NASA's Brady et.al.  I have shown that the buckling time is under 1 second for copper thicknesses under 0.84 mm (33 thousands of an inch) and just 2.6 watt power input.  I have shown that the buckling temperature increase required is of the order of 1 deg C or less.  I have shown that thermal buckling can produce a sudden output response.

I have shown that the calculated buckling forces agree with the measured force (55.4 microNewtons).  The buckling force is a very strong function of plate thickness (to the fourth power), to prevent thermal buckling from occurring it suffices to have a thicker copper sheet (1/8 inch or thicker would completely prevent this thermal buckling under these input powers).

This thermal buckling effect does not depend at all on air as a conducting medium; it will take place in a complete vacuum as well, since the axial magnetic field in the transverse electric mode TE012 results in heating of the copper by producing eddy currents on it.

Thermal buckling of a thin copper sheet produces extremely small reaction forces (microNewtons) and as such it is the kind of effect that is usually disregarded in experiments.  It is of possible concern here due to the experimental methodology of using very small power inputs (2.6 watts in mode TE012) to measure very small forces in the torsional pendulum. 

7. APPENDIX

Cotterell and Parkes (based on Cotterell's Ph.D. thesis at the University of Cambridge) correctly point out that the distribution of the heat flux "is not significant in the problem" of thermal buckling of a circular plate, whether the heating takes place uniformly over the whole circular plate or is concentrated in a central region.  Cotterell chose a distribution with a heatedDiameterRatio =1/0.3=3.333 instead of the heatedDiameterRatio=1 analyzed by Noda et.al.  The fact that the exact distribution is not significant for the deltaT that will produce buckling or for the buckling displacement follows from equilibrium: the membrane stress (=E*alpha*deltaT) force resultant (the integral of the membrane stress through the thickness) is is reacted at the simply supported edges (that constrain the in-plane displacement).  The membrane force resultant is uniform and it is equal in the polar radial and angular (azimuthal) directions.  If only a central area is heated, the membrane stress is still equilibrated throughout.  If the plate has uniform thickness and isotropic material properties, the strain in the non heated area prior to buckling is the same as in the heated area.

The fact that the solution satisfies that these buckling variables are independent of the heated area distribution is shown by the fact that these variables are indeed independent of the heatedDiameterRatio:


bucklingdeltaT =((thickness/ BigDiameter)^2)*( 1.4/( alpha *(1+poissonRatio)))

wBuckling(x,y)=0.724569*thickness*(1-(x/(BigDiameter/2))^2-(y/(BigDiameter/2))^2)       
                            / Sqrt[1+poissonRatio]
   

8. REFERENCES

Brady, D, White, H., March, P., Lawrence, J., and Davies, F., Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum, 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Propulsion and Energy Forum, July 28-30, 2014, Cleveland, OH

Carslaw, H. S., and J. C. Jaeger, Conduction of Heat in Solids, Oxford University Press; 2nd edition (April 10, 1986), ISBN-10: 0198533683

Cotterell, B., and Parkes, E. W.,  Thermal Buckling of Circular Plates, (United Kingdom's) Aeronautical Research Council, Ministry Of Aviation, Reports and Memoranda No. 3245, September, 1960

Noda, N., R. Hetnarskj, Y. Tanigawa, Thermal Stresses, CRC Press; 2nd edition (October 27, 2002), ISBN-10: 1560329718

Roark, R. J., and W.C.Young, Formulas for Stress and Strain, McGraw-Hill Book Company; 5th edition (February 1976) ISBN-10: 0070530319

Timoshenko, S. P., and  J.M. Gere, Theory of Elastic Stability, McGraw-Hill; 2nd edition (1961), ISBN-10: 0070647496
Title: Re: EM Drive Developments
Post by: aceshigh on 11/25/2014 07:49 pm
will a copy of this be forwarded to Dr White?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/25/2014 07:50 pm
I remember that Mach and Einstein ended up being at odds. Mach never accepted Einstein's theory. Check for yourself.

Alto.  You make it sound like there was a scientific feud between 'em.  There was not.

Einstein could not integrate Mach's principle in his work, but Einstein also realized that his own work was incomplete regarding the definition of inertia.
Quote
Sorry.  An immaterial bit of background history regarding Woodward's humility regarding Mach, but still an immaterial bit that adds nothing of substance to the pragmatic implementation of Woodwards's work.

In short.  Who cares?

The point is, and history shows, that Mach didn't accept Einstein's theory. The reason Mach didn't accept Einstein's ideas is because Einstein didn't accept Machian inertia. Einstein stuck with Newton......

Now to the application of this (and why it is important), and the logical paradox that follows from saying that nothing with the Woodward effect violates Einstein's theories.
Quote
Quoting @Ron Stahl: And no, there is nothing in Woodward's work that is inconsistent with Einstein.

Yet Mach's principle is central to the Mach Effect. Mach rejected Einstein. Therefore Mach effects are
inconsistent with Einstein. Einstein operated on Newtonian inertia, which was inherent to matter itself.

Mach effects don't operate using Newtonian inertia.

So Woodward is going his own way. This is no real new insight.

Indeed Woodward acknowledges his split from Einstein several times in his book:

Here's some language from the book, which I have excerpted to show Woodward's disdain for Einstein, in favor of pure Machian ideology, (history and countless experiment shows this is a bad move).

Preface XVII: Woodward commenting on Einstein, "Guided by his version of the Equivalence
principle and what he later called Mach’s principle, he also ignored the standard
techniques of field theory of his day."

Pages 18 & 22 Woodward uses the terminology "so-called Einstein Equivalence Principle". Showing in my view not complete acceptance.

Yet on page 123, He acknowledges EEP as correct: "The reason why the Equivalence Principle is important in this case is that it
asserts that the active gravitational, passive gravitational, and inertial masses of an object are
the same. So, if you vary one of the masses, the other masses change, too. If this aspect of the
Equivalence Principle is correct (and it is), then it is almost trivial to show that mass
variation has serious propulsive advantages."

He acknowledges Einstein is correct in every way, but except how inertia works.

Here's why this is import.

One of the major pitfalls in science, and indeed here on this forum, (whereby picking one theory vs another) is the problem of black and white thinking.

It is clear that neither Newtonian inertia, nor Machian inertia fit the bill. So the truth must be somewhere in the middle. As I have quoted Feynman as saying many times before, "All mass is interaction." The genius of Feynman should not be overlooked, nor should his observations. Now please bear with me while I humbly expand on what the Great Feynman said, "All mass (including inertial mass) is (all) interaction." The true origin of inertial mass is interaction with all fields, near and far. Dr. McCulloch seems to acknowledge this with his theory of MiHsC, whereby he postulates at the edge of galaxies, where gravitational interaction is low and accelerations are low, inertia may in fact behave very differently.

Most things in this world operate on a spectrum.
So should we.

In closing, it makes no sense to dismiss a theory (or pick a horse) based on such black/white thinking. If you want to kill a theory, find paradoxes, as I tried with Mach effect thrusters a couple pages back. It makes no sense to dismiss Mach's ideas on inertia, or Newton, or Haisch&Rueda, or other "QVers." Dollars to donuts, they are all correct. Instead, formulate a theory (or at least your own understanding) on your own that takes into account ALL available information. Not favored information. Open your mind; find the truth.

The reason I keep saying that METs, MLTs, Qthrusters and all that other stuff are related is because of the above reasoning. You can say they're Machian, Quantum Vaccumian, or whatever. Both ideas share the same continuum.

We could save the world further delays by really trying to suss out the similarities of the all these thrusters. Let me start. Electromagnetic interaction (pulsed and RF) with dielectrics supposedly interacting with distant matter and/or the Quantum Vacuum, causing motion.

We need to unify those ideas.

How about putting a MET in a tapered frustum resonant cavity and see what happens?

Op ed complete.

Next subject:

Quoting @Ron Stahl
Quote
"Tomorrow's Momentum Today"
Firstly thank you for making that idea clear on this forum. That really intrigued me, because while I've been trying to study the QV as much as possible lately, I saw this video by some professor who said that he and other believe that Quantum Fluctuations (particle pairs) are briefly taking energy from the very immediate future (picoseconds) holding onto it for a short period of time (picoseconds) and then return that energy to the past when they annihilate.

I'm telling you, we're talking past each other on these supposedly opposing thruster paradigms, they are two faces of the same coin my friends.


Edited some spelling
Title: Re: EM Drive Developments
Post by: Rodal on 11/25/2014 08:13 pm
will a copy of this be forwarded to Dr White?
I have let one of the senior members in his team know through an electronic message by other media (other than this forum).
Title: Re: EM Drive Developments
Post by: Mulletron on 11/25/2014 08:24 pm
In a nutshell....Push while FM is heavy, pull while it is light. But on the flip side, the finite power supply that is exciting the FM is literally strapped down to the RM, reaction mass (the ship). So if the FM is gaining mass, then the power supply is losing mass by the same rationale.

This is very close but not quite right.  The thing that is losing mass when the fluctuating or active mass gains mass, is the rest of the universe.  The reaction mass is just the thing the active mass pushes off of.  The source of the gravinertial flux of the universe, is the mass of the universe itself.  So it is accurate to say, that when a gravinertial transistor like a Mach-Effect Thruster (MET) harvests momentum from the gravinertial field, it is causing the universe to accelerate in its expansion and hastens the arrow of time (entropy).  This is in fact why Tom Mayhoood, Woodward's grad student back in the 90's, put the sign on the lab door reading "Tomorrow's Momentum Today".  This is accurate to the physical theory.

Though Woodward has never weighed in on the issue so far as I'm aware, i would just note this could be an explanation for Dark Energy, or whatever force it is that is causing the observed acceleration in the expansion of the universe.   We've known since 1997, that instead of the universe expanding ever more slowly as it fights its own gravity as we'd expect, the universe is accelerating in its expansion, and this is the effect we ought to observe from LOTS of gravinertial harvesting from Mach-Effect devices.

Given your research, I want your opinion on this:

If a clever mechanical engineer built a MET assembly using strictly hydraulic actuators and fluids. Would it still work? This sounds weird I know, but there is a reason I'm asking you this. If I had a giant one of these hydraulic setups on a boat and a team of men working together to pump a hydraulic chamber with fluid (assuming it is on wheels or something so it'll actually move), push on it, then they withdraw the fluid from the chamber, and then they pull on it. And everything was timed perfectly. Would it still work? If so why? Where is the net force? If not why? What is the most fundamental thing here? Capacitors or mass fluctuations? This is a thought experiment.

Others please chime in.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 08:27 pm
Alto.  You make it sound like there was a scientific feud between 'em.  There was not.
Actually there was.  I suggest you read the essays devoted to this here:

http://www.amazon.com/Machs-Principle-Newtons-Quantum-Einstein/dp/0817638237

If you don't want to pay for it, get it on interlibrary loan.  It's the single best source of info about the historical issues between Einstein and Mach.

Quote
Einstein could not integrate Mach's principle in his work, but Einstein also realized that his own work was incomplete regarding the definition of inertia.

It is anyone's guess what Einstein might have accomplished if he hadn't had the falling out with Mach, but certainly Einstein did not take a stand concerning the origin or inertia, save to coin the term "Mach's Principle" and he did base much of GR on those notions.  Saying he built Mach's Principle into GR would be overstating the issue.  GR is completely compatible with Mach's Principle, but not reliant upon it.

Quote
The reason Mach didn't accept Einstein's ideas is because Einstein didn't accept Machian inertia. Einstein stuck with Newton......
Neither of these statements are true.  You just are shooting from the hip in ignorance here.

Quote
Yet Mach's principal is central to the Mach Effect. Mach rejected Einstein. Therefore Mach effects are
inconsistent with Einstein.
You're having a terrible time trying to form logical syllogisms and really, I dunno what to recommend accept to say, this above is historically, factually and logically wrong.  Mach effects are not inconsistent with Einstein.  That's just silly and preposterous.

Quote
Einstein operated on Newtonian inertia, which was inherent to matter itself.
No, we just agreed that Einstein suspended judgement about inertia, and he did.  You're straining at stuff and making claims with no reason to suppose you might be correct.  Read the book above so you don't make these mistakes.  Barbour makes all this quite clear.

Quote
So Woodward is going his own way.
No, he's not.  You do not understand Einstein, you do not understand Mach and you do not understand Woodward.  I suggest you actually READ these folks before making any more claims like this.

Quote
Indeed Woodward acknowledges his split from Einstein several times in his book:
  Never.  He would never.  Not once.  Show me where I'm wrong here.  I am telling you, never would Woodward deny Einstein is correct.  You are making this stuff up and need to start reading for comprehension.

Quote
Pages 18 & 22 Woodward uses the terminology "so-called Einstein Equivalence Principle". Showing in my view not complete acceptance.
You're fabricating evidence to support your conclusion.  Woodward would never agree to what you're assuming in order to get your conclusion.  You do realize when you put words in other people's mouths like this, you run dangerously close to liable?

Quote
Yet on page 123, He acknowledges EEP as correct: "The reason why the Equivalence Principle is important in this case is that it
asserts that the active gravitational, passive gravitational, and inertial masses of an object are
the same. So, if you vary one of the masses, the other masses change, too. If this aspect of the
Equivalence Principle is correct (and it is), then it is almost trivial to show that mass
variation has serious propulsive advantages."

He acknowledges Einstein is correct in every way, but except how inertia works.
Einstein never took a stand about the origin of inertia.  He liked Mach's explanation, but after their falling out he realized he did not need to rely upon Mach's Principle to get GR.

Quote
One of the major pitfalls in science, and indeed here on this forum, (whereby picking one theory vs another) is the problem of black and white thinking.
Oh for cryin' out loud, don't you dare accuse me of being an adolescent.  Black and white thinking is a characteristically adolescent trait and anyone who has had ad psych knows this.  Your thinking is utterly clouded by your lack of familiarity with the real source materials.  You can't draw conclusions because you're operating from ignorance.  I suggest you read those sources and stop making claims about people's views that you are for the most part, unfamiliar with.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/25/2014 08:36 pm
That first quote in your post isn't me, it is John. And there are some contradictions in your post.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/25/2014 08:45 pm
Fair enough. We'll pump hot liquid mercury in. Push on it. Pump the liquid through a heat exchanger on the way out. Then pull on it. Perfectly timed. How about now?

How is Woodward satisfying the requirement of the thing having to be accelerated in the first place?
For this thought experiment, we'll say it is already being accelerated by X means.

I don't see any way it can ever ever work.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 09:12 pm
PZT is the simplest and cheapest way to test theory.  The stuff is very cheap on Ebay, has fairly large dE/dT and under certain conditions can generate millions of gees accelerations.  Also, PZT can provide 1w piezomechanical action to generate a 2w Mach Effect, and 2w electrostrictive action to rectify that M-E into useful force, both from the same signal; so this is simpler than having to provide 2 separate signals to the thruster.  The down side is the phase angle between the piezo and electrostrictive is locked by the material, so you don't have control over it. 

For mastery purposes, using a material with one or the other of these electromechanical actions would be preferable.  Almost all materials are electrostrictive in some measure, but not all are piezoactive, so choosing a strong electrostrictor with no piezo action affords this opportunity to demonstrate mastery over the phase angle in the lab.  You can for instance, thrust in one direction with 90* phase angle, in the opposite direction at 270* and have no thrust at 000 and 180*; all with the same power into the device.  This is a great way to do a demonstration, which is what Woodward is currently after with the PMN, IIUC.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/25/2014 09:27 pm
So what do you think about the thought experiment? Also....it seems, from your own words, the book, and the Oracle, the acceleration requirement must be relative to the "distant stars." So the acceleration felt by a body at rest here on Earth doesn't satisfy that requirement. What do you think?

This forum thread is the #3 Google search item when people search for EMdrive. The dialogue I'm starting here is an opportunity for you to sell your point.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/25/2014 09:41 pm
I don't think pushing on hot mercury can have the high dE/dT necessary for dramatic effects.  If you want to dabble around at power densities you can (I never do that as my math is not trustworthy--I'm not an engineer) by looking at something like PZT with a k of about 1,000 that diminishes to 700 when clamped, or PMN with a k of 20,000.  Both these materials have an extension that is I think about 1 part in a thousand or 0.1% the thickness, and the frequency they operate on resonance is inversely proportional to thickness.  So proper neighborhood figures could be around 50 Khz, 2cm of these materials would have 200 micron extensions.  You can then get reasonable acceleration here:

http://www.spaceagecontrol.com/calcsinm.htm

I haven't done this in a long time and it is because I don't remember figures like these that I never became an engineer.  So don't trust my math.  Just saying, this is how you can get round figures and I think you'll see, the accelerations and power density of even lowly PZT is very high compared to what you're talking about.  PMN is much higher.  The power density of the special materials we intend to use is vastly higher again, since it has a k of 60,000 at 500 Mhz.

M-E generation scales linearly with frequency and quadratically with k.
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/25/2014 10:32 pm
I wonder if something like they use to investigate the dynamic casimr effect could be used?
I have read of several experimental set ups that use lasers to act as the moving casimir plate. One was that Egyptian girl that was making the satellite maneuver system and the other was someone using it to pull positrons and electrons out of the vacuum at one of the big physics labs.

But anyway if that would work the "mirror" moves at basically light speed or pretty near it.
Title: Re: EM Drive Developments
Post by: 93143 on 11/25/2014 11:34 pm
I don't see any way it can ever ever work.

I'm getting the strong impression that you still think the "mass fluctuations" are just the energy/matter being pumped back and forth in the device.

This is wrong.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/25/2014 11:56 pm
I don't see any way it can ever ever work.

I'm getting the strong impression that you still think the "mass fluctuations" are just the energy/matter being pumped back and forth in the device.

This is wrong.

Yeah you know, you're right. I'm not really addressing the problem here with the initial conditions of that thought experiment.

Quoting @Ron Stahl
Quote
This is very close but not quite right.  The thing that is losing mass when the fluctuating or active mass gains mass, is the rest of the universe.

The notion of how, or the validity of, the rest of the universe losing mass, so that the FM can gain mass, is non trivial. I dismissed it outright without even thinking about it.

Over to you @Ron Stahl

Edit: Page 73 of the book has a nice equation for the mass fluctuations, but nothing to support it other than a reference to the flux capacitor paper. Flux capacitors? Couldn't he have picked a better name that didn't scream gobbledygook? I am understanding why the "QVFers" have the funding. The PR job on Mach effects is just awful.

Here's the flux capacitor paper I found, this is the one referenced by the book :o
http://physics.fullerton.edu/~jimw/flux-cap.pdf

I mean I have an open mind, but dang already.

I see no resemblance.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/26/2014 02:15 am
I just can't mess with Flux Capacitors........and I want to go to space really really really bad.

That's where I'm leaving them. If I'm wrong about them.....Mea Culpa.
Title: Re: EM Drive Developments
Post by: 93143 on 11/26/2014 02:28 am
Flux capacitors? Couldn't he have picked a better name that didn't scream gobbledygook?

The name does more or less match the item.  And hey - if Woodward's ideas about wormholes are borne out too, it might actually end up being what makes time travel possible...

...

It's not the only time someone working on futuristic but potentially legitimate technology has done this.  Tom Ligon, of Polywell fame, once (http://www.fusor.net/board/viewtopic.php?f=14&t=6712#p45824) blew a fist-sized diode and recharged a bank of lead-acid batteries in an instant by mistakenly assuming a research machine called PXL-1 had undergone cathode poisoning, when what had really happened was that it had entered a low-loss mode and was behaving as a dynamic capacitor.

You guess what he decided to call the machine.
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/26/2014 03:11 am
Quote
I just can't mess with Flux Capacitors........and I want to go to space really really really bad.

That's where I'm leaving them. If I'm wrong about them.....Mea Culpa.

Until you change your mind in six or eight weeks. 
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/26/2014 04:04 am
Random thought:  Several years ago a physicist named Mallet was going to experiment with a laser ring or laser cage to create frame dragging to create a microscopic time machine. It would have been constrained to traveling into the past only as far as the time when the machine was first turned on. That is basically identical to Dr. Kramer's description of how a worm hole could create permissible time travel. I think Dr Mallet got null results (at least WRT time traveling subatomic particles) but what about using a similar apparatus to be the test article for Dr white's warp experiment? If its supposed to create measurable inertial frame dragging that should clearly warp space enough for a good measurement system.

Tangentally; I wonder what Dr Mallet would make of the time traveling quantum entanglement experiment that confirmed entanglement is not constrained to the present like just about every other thing in the universe?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/26/2014 01:24 pm
Edit: Page 73 of the book has a nice equation for the mass fluctuations, but nothing to support it other than a reference to the flux capacitor paper. Flux capacitors? Couldn't he have picked a better name that didn't scream gobbledygook? I am understanding why the "QVFers" have the funding. The PR job on Mach effects is just awful.

I have at times made the same complaint.  I do like that Jim renamed the Universal Force Generator (UFG) to the Mach-Effect Thruster (MET).  It's deceivingly important what you call this stuff.  A rose by any other name will smell as sweet, but the name matters regardless.  On the flux capacitor I would point out Jim almost never uses that nomenclature.  It's from the 90's.   And in a business like this, you have to keep a sense of humor.  Jim has done this work for decades now, and without fantastic tenacity and good humor, the only other way anyone could survive such a monumental task would be if they were batty.  Jim's not batty and in fact, this is one of the reasons he posts each week to a list of about a hundred people, to keep his feet to the fire as it were and guard against battiness.  You can find other signs of good humor if you look carefully.  In the second photo from that piece posted up by Gary yesterday, just to the left of the ARC Lite chamber, you'll see peeking up the head of a green velvet stuffed alligator.  There's a humorous story that goes with the lab mascot but I don't recall it just now.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/26/2014 01:41 pm
It makes no sense to dismiss Mach's ideas on inertia, or Newton, or Haisch&Rueda, or other "QVers." Dollars to donuts, they are all correct.

Now that I've had a good night's sleep and a cup of coffee I want to take a moment and address what was for me the most distressing portion of this post.  I do understand the impulse to tell everyone they're right, and I do understand the judgement often made that someone is participating in adolescent reductionism when they take a stand and say someone is wrong.  I would note here though, that we earn our convictions through hard work.  The more you study an issue, the more entitled you become to hold certain convictions on that issue.  This is an issue I've studied for a decade now, and I am indeed entitled to my convictions here, even if I'm wrong.

As regards this notion that ZPF/QVF and M-E are different sides of the same coin--this is Paul March's view and though I disagree, I respect Paul and his views.  Let me explain why I don't think such a thing can be true.

Einstein was never forced to answer the question of whether inertia is an intrinsic property of matter or if there is a mechanism that results in matter's mass.  This is the only point where Einstein and Woodward differ.  Woodward is treating Mach's Principle as true, and MP says that inertia is NOT an intrinsic property of matter, but rather is the result of the gravitational connection between all the universe's bits.  If Mach is correct, then we have some hope we can manipulate inertia as the Mach Effect Thruster claims.

So it can be that inertia is intrinsic to matter, or that it's caused, and if it's caused we have then two theories about how.  ZPF theory says that virtual particles generate a kind of quantum friction that results in inertia.  This is a very different explanation than Mach's, and the two are logically inconsistent with one another.  If you restrict your analysis to only those explanations for inertia where it is caused and not intrinsic, then ZPF theory and M-E theory form what philosophers call an "exhaustive disjunction" in that the two cover all the known explanations and mutually exclude one another.  How do they exclude one another?  They do this because M-E requires that EEP be true, and ZPF requires that EEP be false.  These two theories CANNOT both obtain.  At best one of them can be true, but not both.  They could both be wrong.  Inertia could be an intrinsic property of matter (though few physicists think this likely, and we have to hope not or there's no way to manipulate inertia) but logically, these two explanations for the origins of inertia CANNOT both be true.

IMHO.
Title: Re: EM Drive Developments
Post by: aceshigh on 11/26/2014 04:16 pm
Ron, can you tell us how Paul March addresses this explanation of why ZPF and ME are contradictory, considering he believes they are both sides of the same coin?

I guess that if he believes that, you must have told it to him, and he must have replied disagreeing with you. How he disagrees with what you said above?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/26/2014 04:21 pm
We've had the conversation several times over the years and he hasn't ever responded.  I think though, it's important to remember that Paul is friends with both Jim and Sonny.  I doubt he'd want to go on record as having chosen sides.  The "opposite sides of the same coin" attitude is a politically safe one, even if a bit strained.
Title: Re: EM Drive Developments
Post by: aceshigh on 11/26/2014 04:23 pm
maybe he was not talking about the scientific theory point of view of both being two sides of the same coin, but about practical applications, nature of research, etc?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/26/2014 04:40 pm
I'm pretty sure we understand each other but if he wants to go into more detail he can post about it.  I don't want to put words in his mouth.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/26/2014 05:01 pm
Just an FYI

http://wulixb.iphy.ac.cn/EN/abstract/abstract60316.shtml
Title: Re: EM Drive Developments
Post by: Mulletron on 11/26/2014 07:27 pm
From the abstract:
Quote
When the temperature of the tapered resonant cavity wall rises, the resonant frequency will be decreased and the quality factor changed separately.

This is good to point out but shouldn't be heralded as a new discovery. Metal expands when heated, thus changing the size of the resonant cavity, thus changing the resonant frequency of the system. Larger cavity=lower resonant frequency.

I am pleased there is work happening on this. Progress gentlemen. Thanks for finding that.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/26/2014 07:38 pm
I'm pretty sure the work in China has been going on since Shawyer lost his funding in the UK.  Many people think the Shawyer thing is just a CIA counter-intel OP like the Baker HFGW stuff, only that the Chinese turned around and used back.  I've no idea about this either way.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/26/2014 07:43 pm
I just read the abstract. Just tried and failed on the pdf.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/26/2014 07:48 pm
I'm pretty sure the work in China has been going on since Shawyer lost his funding in the UK.  Many people think the Shawyer thing is just a CIA counter-intel OP like the Baker HFGW stuff, only that the Chinese turned around and used back.  I've no idea about this either way.

(http://basementrejects.com/wp-content/uploads/2013/10/signs-movie-merrill-morgan-bo-tin-foil-tinfoil-hats-hersheys-kisses-joaquin-phoenix-rory-culkin-abigail-breslin-300x168.jpg)

Edit:

Seriously though, given the current geopolitical environment. If our govt gets word that another govt is actually making progress in this kind of research. The dollars will flow like water over at Eagleworks.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/26/2014 09:43 pm
Woodward has been getting a lot of attention lately over at NBF and Boing Boing. I understand that the unfortunate use of the term "flux capacitor" doesn't necessarily detract from the actual science involved. It was a seriously good laugh though, I was laughing so hard I was in tears laughing. As Ron said, it does seem Dr. Woodward has a sense of humor, so maybe he used that term as a ha ha, but it flopped.

I just think the whole concept of a gravinertial flux/field and "flux capacitors" are forced and contrived in order to force a fit with Mach's Principle....eg old (less informed) ideas. If it isn't forced or contrived, then Woodward is indeed a renaissance man of the ages, quite possibly ahead of his time. I want him to be correct, of course. But I must question everything equally.

The current state of the art, which I've devoted considerable time to researching, suggests that inertia isn't due to a singular component. It is the net product of all interaction. I've become keenly aware that popularized science is at least 5 years behind actual science. The popularizers, while extremely valuable ambassadors of science, seem to also stick with over the top and exciting, sensational terms like dark energy, dark matter, blah blah blah. That gets ratings.

I'm watching this video now. It is a good opportunity to hear from the man himself. The audio is kinda bad so you gotta listen closely:
https://www.youtube.com/watch?v=tIvtnh1awFQ#t=37
Title: Re: EM Drive Developments
Post by: Rodal on 11/26/2014 11:43 pm
Just an FYI

http://wulixb.iphy.ac.cn/EN/abstract/abstract60316.shtml

I just read the abstract. Just tried and failed on the pdf.

Here I attach the full paper

Resonance experiment on a microwave resonator system
Shi Feng Yang Juan Tang Ming-Jie Luo Li-Tao Wang Yu-Quan
(College of Astronautics, Northwestern Polytechnic University, Xi’an 710072, China)
Acta Phys. Sinica Vol. 63, No. 15 (2014)


Quote
Abstract
A microwave resonator system is made, which has a tapered resonant cavity, a microwave source, and a transmission device. Because of the electromagnetic pressure gradient on the tapered resonant cavity, a net electromagnetic force along the axis of the cavity may be observed, which is needed to verify experimentally the use of the independent microwave resonator system. It is also needed to keep the independent microwave resonator system in resonating state, which is the important procedure to demonstrate the possibility of net electromagnetic force. Thus, a low-signal resonating experiment on the tapered resonant cavity combined with resonating parts is completed to accurately find out the resonant frequency of 2.45 GHz and to analyze the influence of temperature on the resonant state. Experimental result shows that the resonant frequency and quality factor of the independent microwave resonator system are 2.44895 GHz and 117495.08 respectively. When the temperature of the tapered resonant cavity wall rises, the resonant frequency will be decreased and the quality factor changed separately.

Notice that Fig.1 shows the force "F" directed towards the small base of the truncated cone.

Notice in the last Figure shown below that the increase of temperature vs. time of this truncated cone is much higher than the increase in temperature reported by NASA Brady et.al.  (this is expected because the Chinese run their experiment with up to 385 times higher input power than NASA Brady et.al.'s).
The Chinese report that they run their experiment in Transverse Electric (TE) modes, which give an axial magnetic field at the central axis of the cone. 
Title: Re: EM Drive Developments
Post by: Rodal on 11/27/2014 12:41 am

Here I attach the full paper

Resonance experiment on a microwave resonator system
Shi Feng Yang Juan Tang Ming-Jie Luo Li-Tao Wang Yu-Quan
(College of Astronautics, Northwestern Polytechnic University, Xi’an 710072, China)
Acta Phys. Sinica Vol. 63, No. 15 (2014)


The Chinese paper also repeatedly states that

"the electromagnetic field intensity calculated in the vicinity of the axis is larger, therefore the center of the small end has a higher thermal energy, thus heating quickly,"

as I expected (and contrary to Egan's webpage analysis because Egan did not take into account the heating from the magnetic field producing eddy currents on the copper).

Also it states:

"we measured the cavity surface surface temperature at different locations as shown in Figure 11 with a thermocouple.   [Fig. 11, which I attach below shows the positions of the thermocouples noted as "1" to "6"] Temperature measurements at different points vs.  time, are shown in FIG 12 [Fig 12 which I attach below shows the temperature vs time at the 6 different thermocouple locations]. The temperature at the center of small end [thermocouple #1] first began rising rapidly."

Notice that the temperature of the small end (thermocouple #1) rises much more than the temperature of the big end (thermocouple #6).

Notice that the rise of the temperature vs time at the center of the small end is nonlinear (the upper temperature curve) while the temperature measured at the other locations show fairly linear behavior.


Clearly, there is a large temperature difference between the small end (thermocouple #1) and the large end (thermocouple #6)

Maximum temperature is reached at the center of the small end.

The heating profile is completely different from the one shown by Egan.  Egan's temperature profile is incorrect.

Title: Re: EM Drive Developments
Post by: JohnFornaro on 11/27/2014 02:30 am
...something one would consider as if "grasping at straws"...

Just checked with the mixologist.  She said I could grasp at straws anytime during regular business hours...
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/27/2014 05:29 am
Ok, time for me to demonstrate my lack of comprehension here again:

1) The Chinese paper says the thermal increase was greatest at the small end of the device.

2) Yet if I remember right, the thrust was towards the large end.

So...do we have a straight thermal artifact/effect?  Or a thermal/artifact effect plus something else?

My hazy memory also recollects the neat colored diagram he posted a bunch of pages back showing the weird concentration of something (electrical energy?) towards the big end of the device. 

Ughh...maybe some sort of internal displacement effect?

And why am I seeing multiple screens>.,
Title: Re: EM Drive Developments
Post by: RotoSequence on 11/27/2014 09:53 am
http://www.fz-juelich.de/SharedDocs/Pressemitteilungen/UK/EN/2014/14-11-26van-der-waals-kraft.html

According to this paper (http://www.nature.com/ncomms/2014/141126/ncomms6568/full/ncomms6568.html), the strength of the van der Waals force increases disproportionately with the size of the molecule. Perhaps the impact of teflon in an EM drive stems from sort of relationship between EM drives and van der Waals forces?
Title: Re: EM Drive Developments
Post by: Mulletron on 11/27/2014 10:17 am
http://m.phys.org/news/2014-07-boosting-space.html

Use your imagination. Happy turkey day!
Title: Re: EM Drive Developments
Post by: frobnicat on 11/27/2014 12:13 pm
I'm in lurker mode for the time being. Not chasing the virtual particle through the quantum rabbit hole, but while searching on introductory material on the added mass of agitation, thermal or harmonic (something hot is slightly more massive that something cold, and same for a vibrating bulk, isn't it ?) to get a grasp on "ME effect", stumbled on this paper (not fresh) that might be added to the assorted link for those interested in the Unruh connexion :
Some Heuristic Semiclassical Derivations of the Planck Length, the Hawking Effect and the Unruh Effect (http://arxiv.org/pdf/gr-qc/0206025.pdf)
Conclusions in the lines of "... stresses the link between Unruh effect and Hawking effect, and the latter appears clearly to be a particular case of the former."
Title: Re: EM Drive Developments
Post by: Rodal on 11/27/2014 12:53 pm
Ok, time for me to demonstrate my lack of comprehension here again:

1) The Chinese paper says the thermal increase was greatest at the small end of the device.

2) Yet if I remember right, the thrust was towards the large end.

....

1) No, as I remarked (in bold) in my message http://forum.nasaspaceflight.com/index.php?topic=29276.msg1293800#msg1293800, Fig.1 of the 2014 Chinese paper (attached below) shows the force (indicated by "F" at the small end) directed towards the small end.  The same end that gets heated up the most and gets heated much faster: the small end.

2) As apparent from the discussion we had with Mulletron several pages ago, the EM Drive researchers present contradictory and sometimes (as in Shawyer) even self-contradictory information concerning thrust direction.  As remarked by Mulletron, Shawyer defines thrust in the opposite direction as to what is the conventional definition of thrust in aerospace.   The lack of clarity of different authors in showing clearly the direction of thrust and defining thrust as per standard conventions should be very disappointing (to say the least) to anyone looking seriously at these experiments.   To confuse matters further, take a look at Shawyer's chart below: where Shawyer admits that different places measured force in opposite directions, and that Shawyer himself measured force for the "Demonstrator" in opposite directions (214 in "Shawyer thrust" direction and 243 in "Shawyer reaction" direction").  Shawyer indicates the Chinese (NWPU) as measuring force in the "Shawyer reaction" direction, which Shawyer defines as directed towards the small end, and this is consistent with Fig.1 of the Chinese 2014 paper attached below.

3) If the Chinese had a dielectric on the large end interior surface, I would interpret it as insulating the large end from direct heating by eddy currects from the axial magnetic field and hence only the center of the small end being heated directly through the thickness. 

Otherwise, if the Chinese are measuring significant thrust without a dielectric (so much then for NASA's remarks concerning the importance of the dielectric to couple with the Quantum Vacuum !) one would need to analyze the actual magnetic field in this cavity: does the axial magnetic field in the transverse electric operating mode only contact the small end and does not contact the large end? (This is the interpretation that follows from the Chinese paper.).

 Later (a slower diffusion process) the large end would still be heated by conduction from the walls (as the thermal diffusivity and thermal conductivity of copper is -relatively to other materials in general- very high).  This will be shown as the large end having the same temperature rise as the walls.  This is what is observed. 

I leave it to others to come up with an interpretation using the Quantum Vacuum, Woodward effect, or other exotica (non-classical physics).

4) Kudos to the Chinese for being the first researchers inserting thermocouples throughout the cavity to measure and display temperature vs. time at different locations (instead of summarily dismissing thermal effects as done by others or to use an infrared camera to look at the outside of the cavity with very low resolution instead of measuring the inner surface temperature which is what matters, due to the skin effect).  Neither Shawyer nor NASA had inserted thermocouples on the inner surfaces to measure temperature vs. time.

5) To this date, nobody (not the Chinese, not Shawyer, not Cannae and not NASA) has reported force measurements of the EM Drives in a vacuum, and nobody has reported measurements as a free-body (as done by Goddard with his early rocket experiments or by Freeman and Taylor under Project Orion for their explosive-impulsively loaded experiments). 
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/27/2014 08:55 pm
::Memo to self.  Post while awake!  It helps with reading comprehension.::

Rodal -

So if I follow you correctly this time, you advocate a purely or mostly thermal explanation for the thrust produced by the Chinese devices?

And, in one of the more recent links, I seem to remember Woodward testing his device in an improvised (?) vacuum chamber. 
Title: Re: EM Drive Developments
Post by: cuddihy on 11/27/2014 11:16 pm
Rodal, this has to be an NSF first - professional physics paper rebuttal exclusive to NSF! Impressive.

It would be possible for Eagleworks to eliminate thermal buckling as source of observed force by simply changing the attachment point of the device to the balance, no?

-ed: what I mean is if they attached the device at a different point, for instance, by a strut attached to both the small and large end, it should eliminate buckling force, correct?
Title: Re: EM Drive Developments
Post by: Rodal on 11/28/2014 02:27 pm
::Memo to self.  Post while awake!  It helps with reading comprehension.::

Rodal -

So if I follow you correctly this time, you advocate a purely or mostly thermal explanation for the thrust produced by the Chinese devices?

I have found a number of classical physics mechanisms for the results: thermal buckling (published in this forum) under TE modes, thermoelastic dynamic coupling (have obtained solution, too complicated and lengthy to publish in this forum) under TE modes, and electric charge buckling (similar to what happens in MEMS) under TM modes.  All three of this require very thin (significantly less than 1/16 of an inch) copper thickness.

Concerning an exotic physics explanation, it is interesting that this latest paper by Prof. Juan Yang (2014) in its section 5.2.2 "Cavity surface temperature variation" explains the experimental fact that the inner surface center of the small base of the truncated cone experiences a much higher temperature and much higher temperature rise than the other surfaces using similar group velocity argumentation (based on the earlier numerical calculations by Prof. Yang).  The Chinese paper never discusses whether they used a dielectric that could have insulated the big end.  Their lack of discussion of any dielectric and the fact that they argue that the measured force towards the small end and the temperature increase of the small end are due to the group velocity leads one to understand that the Chinese did not use a dielectric.   

They write that the wavelength (lambda) at the small end needs to be close to the cut-off wavelength (lambdaC) lambda=lambdaC, such that the group velocity is close to zero vg = c Sqrt[1- (lambda/lambdaC)^2] = 0 at the small end. They write that at the large end the required wavelength of electromagnetic waves is the free-space wavelength (lambda0) such that the the group velocity at the large end is vg = c Sqrt[1- (lambda0/lambdaC)^2]. They write that this indicates that the electromagnetic wave energy transfer to the small end must all be converted into heat within the skin depth of the small end face and that this agrees with their previous numerical calculations for an unequal force pointing towards the center of the small end.

So, the Chinese use similar "group velocity, free-space wavelength and cut-off wavelength" rationale as Shawyer.  However, the Chinese have conducted a more thorough experimental program than Shawyer: the Chinese have conducted numerical finite element analysis of the TE modes (I have not seen similarly reported analysis by Shawyer) and the Chinese have measured and reported the effect of temperature on the frequency and Quality "Q" factor.

Even if one dismisses Shawyer's and the Chinese explanation, the fact remains that they claim to have measured a signficant force pointing towards the small end and that their temperature measurements show that the small end heated much more and with a much higher temperature rise than the large end. 

These experimental results are completely contrary to Greg Egan's http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html  temperature (that shows significantly higher temperature at the walls than at the ends:)
(http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/TEheat2.gif)
and force results. I think that Greg Egan's temperature calculations are incorrect:  Egan does not take into account eddy-current heating from the axial magnetic field in the TE modes, and Egan relies on a straight heat conversion from the energy density (which to me is an incorrect way to calculate temperature, as heat transfer is not due to energy density but it is due to specific heat transfer mechanisms: mainly eddy current heating in the TE mode as the electric field in the TE mode must be zero at the inner surface).
Title: Re: EM Drive Developments
Post by: Rodal on 11/28/2014 02:47 pm
1) No, as I remarked...

2) As apparent from the discussion we had with Mulletron...

3) If the Chinese had a dielectric...

4) Kudos to the Chinese...

5) To this date, nobody...

Rodal: After giving thanks for making it thru a year of "massive" life changes, I sit again before the screen and keyboard and offer you thanks for your patient repetition, over and over again, regarding these results.  And the work which you prosecute with remarkable thoroughness.

At least I grasp at real straws with detectable mass.

(You too, Mulletron, Frobnicat, and others.)

Thank you  :)
Title: Re: EM Drive Developments
Post by: Rodal on 11/28/2014 02:53 pm
Rodal, this has to be an NSF first - professional physics paper rebuttal exclusive to NSF! Impressive.

It would be possible for Eagleworks to eliminate thermal buckling as source of observed force by simply changing the attachment point of the device to the balance, no?

Thank you  :).

The best way to eliminate the possibility of thermal buckling (or electric charge buckling as experienced in MEMS) or thermoelastic dynamic coupling is simply to make the copper wall thick enough.  I am confident that for the power inputs and diameter dimensions that have been used a 1/4 inch thickness of copper would be significantly more than enough to rule out the possibility of buckling.  1/8 of an inch is much more than enough for the NASA experiments.

Concerning support if the whole truncated cone has equal stiffness it would not make much difference where it is supported along the axis of the cone, as the reaction force still would be transmitted.  In a real situation there may be compliance at the connections that will diminish the measured dynamic magnification factor of the pendulum response, but the reaction will still be measurable (although the dynamic magnification factor may be smaller due to greater compliance: lower stiffness at the connections).  So I think that the best way to rule out buckling is simply to employ thicker copper, as buckling is a nonlinear function of thickness.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 11/28/2014 04:02 pm
. . .To this date, nobody (not the Chinese, not Shawyer, not Cannae and not NASA) has reported force measurements of the EM Drives in a vacuum, and nobody has reported measurements as a free-body (as done by Goddard with his early rocket experiments or by Freeman and Taylor under Project Orion for their explosive-impulsively loaded experiments).

This is why I have taken the stand that I don't think there's anything here.  Given all the proposed theories of operation violate one important part of accepted science or another and that they don't get thrust in vacuum, it seems very odd to me that anyone gives this their attention.  The fact this had lots of funding for years, and finally the Brits cut it loose, seems explanation enough.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/28/2014 04:52 pm
Finally got a few (snowed in) minutes to look at the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator.

g= (X[subm,n])^2*c^2*lambda*((1/a^2)-(1/b^2)) where a anb b are the end plate radii and the X are the Bessel function zeros.  Lambda < cutoff wavelength.

Notice that the axial index does not appear here but should appear when forces are derived.  So-so for now.

Edit: Should have mentioned: to 1st order using massless, perfectly conducting cavity.
Title: Re: EM Drive Developments
Post by: Rodal on 11/28/2014 06:12 pm
Finally got a few (snowed in) minutes to look at the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator.

g= (X[subm,n])^2*c^2*lambda*((1/a^2)-(1/b^2)) where a anb b are the end plate radii and the X are the Bessel function zeros.
...

The zeros of the Bessel functions of the first kind (J) ?

BesselJZero[0, 1] = 2.40483
BesselJZero[0, 2] = 5.52008
BesselJZero[0, 3] = 8.65373
and so on?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/28/2014 06:45 pm
Finally got a few (snowed in) minutes to look at the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator.

g= (X[subm,n])^2*c^2*lambda*((1/a^2)-(1/b^2)) where a anb b are the end plate radii and the X are the Bessel function zeros.
...

The zeros of the Bessel functions of the first kind (J) ?



BesselJZero[0, 1] = 2.40483
BesselJZero[0, 2] = 5.52008
BesselJZero[0, 3] = 8.65373
and so on?

X[subm,n] = m-th root of dJ[subn](x)/dx = 0

[1,0]= 3.83, [1,1]=1.84, [1,2]=3.05, [2,0]=7.02, [2,1]=5.33, [2,2]=8.54, [3,0]=10.17, etc

Quickie calculation to rotate waveguide into doppler frame for g.  Needs more work but should be able to get to forces if I get time to keep head clear.
Title: Re: EM Drive Developments
Post by: Rodal on 11/28/2014 08:36 pm
Finally got a few (snowed in) minutes to look at the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator.

g= (X[subm,n])^2*c^2*lambda*((1/a^2)-(1/b^2)) where a anb b are the end plate radii and the X are the Bessel function zeros.
...

The zeros of the Bessel functions of the first kind (J) ?



BesselJZero[0, 1] = 2.40483
BesselJZero[0, 2] = 5.52008
BesselJZero[0, 3] = 8.65373
and so on?

X[subm,n] = m-th root of dJ[subn](x)/dx = 0

[1,0]= 3.83, [1,1]=1.84, [1,2]=3.05, [2,0]=7.02, [2,1]=5.33, [2,2]=8.54, [3,0]=10.17, etc

Quickie calculation to rotate waveguide into doppler frame for g.  Needs more work but should be able to get to forces if I get time to keep head clear.

Thanks.  For anybody interested, these values can be found on page 411 of this classic:

Handbook of Mathematical Functions, Abramowitz and Stegun, National Bureau of Standards, 3rd printing, 1965

http://www.amazon.com/Handbook-Mathematical-Functions-Formulas-Mathematics/dp/0486612724/ref=sr_1_1?ie=UTF8&qid=1417210659&sr=8-1&keywords=Handbook+of+Mathematical+Functions%2C+Abramowitz+and+Stegun

Also, for those with Mathematica, here is a code to compute them:   http://www.me.rochester.edu/courses/ME201/webexamp/derbesszer.pdf

Title: Re: EM Drive Developments
Post by: Mulletron on 11/28/2014 10:01 pm

So...do we have a straight thermal artifact/effect?  Or a thermal/artifact effect plus something else?


IMHO, we have heat artifacts (mostly evident to me in the TE012 plot, figure 22 page 18, and through Rodal's exhaustive work) and something else. That something else is IMHO related to Casimir effects, as I've posted.

It certainly is interesting how it seems that TE mode seems to be the best Q thruster solution in terms of input power to thrust. I've been torn between the diamagnetic QED vacuum idea and the asymmetric QV/RF interaction with atoms, not summing to zero in the asymmetric cavity, giving rise to a force. Given the TE mode outlier, I think the answer is both.  I remember Dr. White mentioning in the video I recently posted here, that a great RF solution doesn't necessarily mean a great Q thruster solution. I've taken that to heart.

Over the last few days, I've been trying fit all the Casimir momentum/dielectric stuff I've posted over the last few months, into the framework of Cavity QED. I think this is the final concept to understand in order to create a fully functional QV framework in order to describe the Anomalous thrust from these two devices. I can't find a single paper on Casimir cavity QED, but I've found talk about this stuff dating way back to 2004. These guys were chasing the same idea long long ago it turns out.

http://cosmoquest.org/forum/showthread.php?14897-Casimir-Effect-and-Vacuum-Fluctuation-Propulsion

In a nutshell, what I'm getting at here (and I'll put it into math if I can ever find the confidence to express ZPE IIRC 1/2 hbar omega for the given frequencies inside a sloping cavity), in a sloping resonant Casimir cavity, you end up with a situation inside the cavity where the modes allowed isn't just a simple to derive value, as you would get in parallel plates for example (see the Milonni video). You end up with a continuously changing value over the length of the cavity. This Casimir force acts on the atoms in the cavity. That is one side of the interaction....... The other side of the interaction is the RF behaving in a similar manner, both interacting with the atoms in the air and dielectric in the cavity. The resulting non zero summation of these competing forces is IMHO the cause of the thrust.

So essentially I've reached the pinnacle of this avenue with a horrendous math problem that is Dr. Milonni caliber. Will I ever figure it out? Probably not. It is fun trying to find One-Eyed Willy's gold though. Somebody will eventually figure it out.




Title: Re: EM Drive Developments
Post by: Rodal on 11/29/2014 02:56 am

So...do we have a straight thermal artifact/effect?  Or a thermal/artifact effect plus something else?


IMHO, we have heat artifacts (mostly evident to me in the TE012 plot, figure 22 page 18, and through Rodal's exhaustive work) and something else. That something else is IMHO related to Casimir effects, as I've posted.

It certainly is interesting how it seems that TE mode seems to be the best Q thruster solution in terms of input power to thrust. I've been torn between the diamagnetic QED vacuum idea and the asymmetric QV/RF interaction with atoms, not summing to zero in the asymmetric cavity, giving rise to a force. Given the TE mode outlier, I think the answer is both.  I remember Dr. White mentioning in the video I recently posted here, that a great RF solution doesn't necessarily mean a great Q thruster solution. I've taken that to heart.

Over the last few days, I've been trying fit all the Casimir momentum/dielectric stuff I've posted over the last few months, into the framework of Cavity QED. I think this is the final concept to understand in order to create a fully functional QV framework in order to describe the Anomalous thrust from these two devices. I can't find a single paper on Casimir cavity QED, but I've found talk about this stuff dating way back to 2004. These guys were chasing the same idea long long ago it turns out.

http://cosmoquest.org/forum/showthread.php?14897-Casimir-Effect-and-Vacuum-Fluctuation-Propulsion

In a nutshell, what I'm getting at here (and I'll put it into math if I can ever find the confidence to express ZPE IIRC 1/2 hbar omega for the given frequencies inside a sloping cavity), in a sloping resonant Casimir cavity, you end up with a situation inside the cavity where the modes allowed isn't just a simple to derive value, as you would get in parallel plates for example (see the Milonni video). You end up with a continuously changing value over the length of the cavity. This Casimir force acts on the atoms in the cavity. That is one side of the interaction....... The other side of the interaction is the RF behaving in a similar manner, both interacting with the atoms in the air and dielectric in the cavity. The resulting non zero summation of these competing forces is IMHO the cause of the thrust.

So essentially I've reached the pinnacle of this avenue with a horrendous math problem that is Dr. Milonni caliber. Will I ever figure it out? Probably not. It is fun trying to find One-Eyed Willy's gold though. Somebody will eventually figure it out.

Cavity QED with Single Atoms and Photons

T. E. Northup, K. M. Birnbaum, A. Boca, A. D. Boozer, J. McKeever, R. Miller, and H. J. Kimble
Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, CA 91125

http://authors.library.caltech.edu/2781/1/NORaipcp05.pdf
Title: Re: EM Drive Developments
Post by: Mulletron on 11/29/2014 09:19 pm
Slide 66  :)

http://aphyr.com/media/pwl-2014-casimir.pdf
Title: Re: EM Drive Developments
Post by: Rodal on 11/29/2014 09:43 pm
Slide 66  :)

http://aphyr.com/media/pwl-2014-casimir.pdf

He wrote this in 2009/06/07:

"I just finished my last undergrad assignment—Hector's E&M test. Got an A in the course, actually, which really surprised me. I'm now done with Carleton, and graduate in a week. I'll be living in Madison for a few weeks, and then moving out to San Francisco for my new job. Should be exciting!"  http://aphyr.com/tags/carleton

And here is his presentation as of that time:  http://aphyr.com/media/comps.pdf

Anyway here is his October 22, 2014 video presentation at the Meetup group in San Francisco http://www.meetup.com/papers-we-love-too/events/187600122/ .  Quite a good presenter, he involves the audience and makes it simple and practical.


At approximately 47:30 he addresses the EM Drive, he says it appears to violate conservation of momentum, which is "not good", he says it is a "mystery".   He doesn't buy Dr. White's virtual particles plasma explanation as the quantum vacuum "is not a plasma":

https://www.youtube.com/watch?v=wsC-WTV4OzU#t=2854
Title: Re: EM Drive Developments
Post by: ThinkerX on 11/29/2014 11:55 pm
Professor McCulloch has updated his blog:

http://physicsfromtheedge.blogspot.com/

This time he included a list of anomalies his theory predicts or accounts for in full or in part, including some terrestrial ones:

Quote
Cosmic acceleration: MiHsC predicts this as an effect of the cosmic horizon.
 The low-l cosmic microwave background anomaly: MiHsC predicts it as above.
 Cosmic mass: just enough to keep the cosmos closed: MiHsC predicts it.
 The anomalous motion of galaxy clusters: MiHsC predicts it without dark matter.
 Bullet cluster: MiHsC might fit, but there's not enough data to test it yet.
 The galaxy rotation anomaly: MiHsC predicts it without dark matter.
 Globular cluster rotation anomaly: MiHsC might fit, needs a computer model.
 Observed minimum galactic masses: MiHsC agrees.
 Is Alpha Centauri-C bound?: MiHsC predicts it's bound, agrees with independent data.
 Flyby anomalies: MiHsC agrees partly, but the analysis is incomplete.
 Pioneer anomaly: MiHsC agrees, but there's another 'complex' thermal explanation.
 Tajmar effect: MiHsC predicts it.
 EmDrive: MiHsC predicts it.
 Poher experiments: MiHsC is consistent, not enough data to test numerically.
 Podkletnov effect: MiHsC predicts the non-spinning part of it. needs more work..
 Sonoluminescence: MiHsC predicts the observed core temperature.
 Planck mass: MiHsC predicts it within 26%.

And things on his 'to look at' list:

Quote
Quasars are aligned with each other and cosmic filaments.
 The Andromeda satellite galaxies orbit in a disk.
 Galactic relativistic jets.
 The wide binary rotation anomaly.
 Anomalous, non-tidal, increase of lunar distance.
 Increase in the Astronomical Unit.
 Modanese effect: jump of masses near a cooler superconductor.
 Anomalies in the gravitational constant, big G.

To me, it seems as though his theory has more supporting evidence going for it than does Dark Matter, Dark Energy, or String theory.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/30/2014 12:35 am
Slide 66  :)

http://aphyr.com/media/pwl-2014-casimir.pdf

At approximately 47:30 he addresses the EM Drive, he says it appears to violate conservation of momentum, which is "not good", he says it is a "mystery".   He doesn't buy Dr. White's virtual particles plasma explanation as the quantum vacuum "is not a plasma":


Good find on the video. Indeed the mystery here is the still not well accepted or understood behavior of the QV. From what I've learned so far about the QV and quantum fluctuations, which I may be wrong because I'm learning about them, is that these fluctuations don't have a defined or net momentum. They don't have any particular direction of travel. Also they are known to violate conservation of energy for short periods of time, and apparently that is okay over very short periods of time. Over the long haul, energy is conserved, which is nice.

But using the QV approach, would make the thruster appear to violate conservation of momentum at first.

So here's some observations I have based on the above.....The Dr. White approach of pushing on the QV, does violate conservation of energy and momentum. Here's why I think so. He is essentially trying to push on something (particle pairs) which later goes on carry away that momentum into oblivion when they annihilate, thus destroying the energy used to impart momentum to those virtual particles. Also, the act of trying to push on something that isn't there, at least to me, has no meaning. See below, for Ralph's explanation.

The other issue is calling the QV a plasma. We all know that is bad. He seems to have switched to Q-thruster, which is nice. That'll keep those celebrity physicists off his back, but the damage is done. Couldn't  Sean Carroll and John Baez have picked a more academic thing to argue about instead of nitpicking words? Deplorable. But I digress...

What I'm exploring with all this QV stuff is how to convert this random walk, see video below, into a less random walk, with a bias in direction I want to fly. I'm trying to figure out how the shape of the cavity and the dielectrics (should work with just air too, just not as well) used can allow the QV to push a particle in the direction of intended travel, when RF is switched on, resulting in thrust. I'm not trying to push against the QV, instead I'm letting the QV do all the pushing. I'm trying to show, that the anisotropic rf environment inside the emdrive can influence the isotropic vacuum environment, which in turn becomes an anisotropic vacuum environment locally inside the cavity. I don't think this is woo woo science, just not easy to understand science.

Edit:
Adding on to the above, and the stuff posted way back about about how the QV interacts with dielectrics....Inside the resonant cavity, given the nature of the Casimir effect, there is no doubt a very small, but non zero force, similar to what was measured by Casimir et al using parallel plates and cantilevers. Being that the walls of the cavity are far away from each other and not parallel, this force must be indeed extremely small. Don't even ask me to calculate it. :)

We know that copper conical frustums don't try and move on their own. Only when RF is applied is a force measured. So the cavity must be serving to amplify and direct the effect of these vacuum fluctuations in a fashion similar to here: http://www.sciencedaily.com/releases/2014/07/140722091425.htm. Sorry to post a news article, but that's all I have at the moment. This is all pretty new stuff, published papers on amplifying vacuum fluctuations and Casimir cavities are pretty thin. I did post a bunch of papers way back (page 88) that led me to believe that the force inside Casimir cones was repulsive.

So that pretty much closes the rough idea loop on how this thing might work, in my mind anyway.

http://youtu.be/lWlkDXtUDgQ?list=UUrumw1oc1Tt8hL3jGFtXDMg





Title: Re: EM Drive Developments
Post by: aero on 11/30/2014 02:07 am
I've been off fooling with Maxwell's equations in the time domain for a little while. Still not done but I did make up a little table of information that might interest some folks. I found it interesting at least.

      resonate cavity
Dielectric   resonate   length, d
constant   frequency   d=3*Lamda/2
1.1   2.12532E+009   0.2115868083
1.7599   1.88050E+009   0.2391327204
2.3   1.76365E+009   0.2549755493
2.6   1.71550E+009   0.2621326819
2.8   1.68780E+009   0.2664351324
4.2   1.54831E+009   0.2904389858

The first column is the dielectric constant of the P.E. dielectric resonator. Turns out that the Brady cavity dielectric was neither soft nor dense. The dielectric constant for 100% density P.E. is 2.3, and it is 1 for 0% density of course. It looks like the Brady cavity dielectric was about 1.76, or about 50% P.E. density.

You'll note that as the dielectric constant increases, the resonate frequency goes down so the wavelength goes up, hence the resonate length, 2 d = n Lamda, n= 1, 2, 3, 4, ... For the Brady cavity, n = 3 so d= 3 Lamda / 2. The resonate length of the cavity goes up, but of course the physical length of the cavity doesn't change.

I've been trying to formulate a thought experiment to examine the momentum as the RF radiation enters and leaves the dielectric, but no luck so far. Does light slow down in the dielectric? The above numbers would say that it speeds up, that is if light speed = c in the empty part of the cavity. What does momentum say? E = h f and p = h f /c where h is Plancks constant and f is frequency. Light slows down as it enters water, then speeds again as it exits. The RF waves must behave similarly on entering and leaving the dielectric.

So I wonder what really happens inside the cavity?  ;)
Title: Re: EM Drive Developments
Post by: cuddihy on 11/30/2014 02:14 am
Rodal, this has to be an NSF first - professional physics paper rebuttal exclusive to NSF! Impressive.

It would be possible for Eagleworks to eliminate thermal buckling as source of observed force by simply changing the attachment point of the device to the balance, no?

Thank you  :).

The best way to eliminate the possibility of thermal buckling (or electric charge buckling as experienced in MEMS) or thermoelastic dynamic coupling is simply to make the copper wall thick enough.  I am confident that for the power inputs and diameter dimensions that have been used a 1/4 inch thickness of copper would be significantly more than enough to rule out the possibility of buckling.  1/8 of an inch is much more than enough for the NASA experiments.

Concerning support if the whole truncated cone has equal stiffness it would not make much difference where it is supported along the axis of the cone, as the reaction force still would be transmitted.  In a real situation there may be compliance at the connections that will diminish the measured dynamic magnification factor of the pendulum response, but the reaction will still be measurable (although the dynamic magnification factor may be smaller due to greater compliance: lower stiffness at the connections).  So I think that the best way to rule out buckling is simply to employ thicker copper, as buckling is a nonlinear function of thickness.

Unfortunately there are plenty of excuses possible for not changing the end caps if you're ambivalent about falsification. From the perspective of White et al, "we just got it working!..."

So I doubt they'll jump on any test that requires physically modifying a "working" device. I'm suggesting, however, if you instead support the device at both ends with a fork-shaped strut, Eagleworks could falsify or confirm the thermal buckling theory without changing the actual cone.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/30/2014 02:25 am
I've been trying to formulate a thought experiment to examine the momentum as the RF radiation enters and leaves the dielectric, but no luck so far. Does light slow down in the dielectric?

IIRC it is the phase velocity that changes when light/RF enters a medium and is refracted IAW Snell's law. So frequency stays the same, c (in a vacuum) stays the same, phase velocity changes. The speed of light does slow in a medium though by absorption and re-emission. Hope I answered what you were asking for.

Here:
http://en.wikipedia.org/wiki/Refractive_index#Dielectric_constant
Title: Re: EM Drive Developments
Post by: Stormbringer on 11/30/2014 03:47 am
Light does travel at different speeds in different mediums. When particles are emitted in fission underwater the speed of light slows such that the emitted particles exceed the speed for the medium and a blue glow called Cherenkov radiation results.
Title: Re: EM Drive Developments
Post by: aero on 11/30/2014 04:13 pm
@Mulleton & @Stormbringer,

That's good information but what I'm wondering about is simply this:
As the dielectric constant goes up, the resonate wave length of the RF increases so light takes more time to make the round trip in resonance. But the Cavity length does not increase nor does the air-filled length increase. So the trip time across the air-filled length stays constant with light speed=c. Now looking at the difference between dielectric constant of 1.76, and 4.2, the resonate distance increases by about 15% but the physical distance of course remains the same.

Note that quality factor, Q in all cases in the table is on the order of 10E+7 so I think that means that group velocity and phase velocity are nearly equal. How can the RF waves effectively travel 15% farther while slowing in the dielectric and traversing the same physical distance? I don't doubt that they do, just wonder how to interpret it using simplified geometry/math and English.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/30/2014 06:48 pm
Ok so the refractive index of a material is the ratio of light speed in a medium wrt light speed in a vacuum. Quoting the Oracle by copy and paste, "For example, the refractive index of water is 1.33, meaning that light travels 1.33 times faster in a vacuum than it does in water."

You can calculate the refractive index by taking the sqrt erur. Relative permittivity isn't the same across the frequency spectrum, because absolute permittivity changes wrt frequency.

Quote
How can the RF waves effectively travel 15% farther while slowing in the dielectric and traversing the same physical distance?
Something doesn't seem right about that.

Quote
difference between dielectric constant of 1.76, and 4.2
That seems like an awfully large spread for a ~580mhz freq range.

http://users.tm.net/lapointe/Plastics.htm

So the relative permittivity stays the same within this frequency domain.

http://www.rfcafe.com/references/calculators/wavelength-frequency-calculator.htm
Now changing the relative permittivity of what's in there greatly changes the resonant frequency, of course, but that isn't what is going on. The same PE puck is being used, and it's relative permittivity remains pretty much constant over the frequencies in use.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/30/2014 07:34 pm
OK, second look (found one error so far) at the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator to 1st order using massless, perfectly conducting cavity. Quickie calculation to rotate waveguide into doppler frame for acceleration g.

g = (X[subm,n])^2*(c/4*pi^2)*lambda^2*((1/a^2)-(1/b^2))

where a anb b are the end plate radii and the X are the Bessel function zeros.

X[subm,n] = m-th root of dJ[subn](x)/dx = 0

[1,0]=3.83, [1,1]=1.84, [1,2]=3.05, [2,0]=7.02, [2,1]=5.33, [2,2]=8.54, [3,0]=10.17, etc.

Lambda < cutoff wavelength.

Lambda is the free space wavelength c/f.

giving thrust per photon:

T = (X[subm,n])^2*(h/4*pi^2)*lambda*((1/a^2)-(1/b^2))

If the number of photons is power * Q / hf then I should be able to try some numbers (and possibly find more mistakes)

T = P*Q*(X[subm,n])^2*(c/4*pi^2)*lambda^2*((1/a^2)-(1/b^2))

Doesn't look too obvious, but we'll see what else I've missed.
Title: Re: EM Drive Developments
Post by: Rodal on 11/30/2014 07:55 pm
OK, second look (found one error so far) at the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator to 1st order using massless, perfectly conducting cavity. Quickie calculation to rotate waveguide into doppler frame for acceleration g.

g = (X[subm,n])^2*(c/4*pi^2)*lambda^2*((1/a^2)-(1/b^2))

where a anb b are the end plate radii and the X are the Bessel function zeros.

X[subm,n] = m-th root of dJ[subn](x)/dx = 0

[1,0]=3.83, [1,1]=1.84, [1,2]=3.05, [2,0]=7.02, [2,1]=5.33, [2,2]=8.54, [3,0]=10.17, etc.

Lambda < cutoff wavelength.

Lambda is the free space wavelength c/f.

giving thrust per photon:

T = (X[subm,n])^2*(h/4*pi^2)*lambda*((1/a^2)-(1/b^2))

If the number of photons is power * Q / hf then I should be able to try some numbers (and possibly find more mistakes)

T = P*Q*(X[subm,n])^2*(c/4*pi^2)*lambda^2*((1/a^2)-(1/b^2))

Doesn't look too obvious, but we'll see what else I've missed.

Kudos !

(http://media3.giphy.com/media/jShr8wkP38XTO/giphy.gif)

and a few

QUESTIONS:

1) What is the actual acceleration (formula used for acceleration and variables inside it)  of the accelerating frame of reference under your consideration?

2) Defining thrust force of a rocket to be in the same direction as the motion of the rocket, what is the direction of the thrust force according to your EM drive formula? Is it directed towards the small end or towards the large end?

3) For your formula, does it make a difference whether the cavity's mode is TE (outer circumferentially electric with an inner axial magnetic field) or TM (outer circumferentially magnetic with an inner axial electric field) ?

4) So the proposition that an accelerating frame of reference caused by a dispersive cavity resonator gives you a net thrust (as long as the ends have different diameter) proportional to Q even though there are no photons escaping the cavity?  What is the explanation for conservation of momentum? That one has to consider an open system because of the accelerating frame of reference?



PS: for the final equation giving the thrust as a function of the power input, Q, wavelength and radii:

T = P*Q*(X[subm,n])^2*(c/4*pi^2)*lambda^2*((1/a^2)-(1/b^2))

T =thrust force
P= power input
Q=quality factor
X[subm,n]=  m-th root of dJ[subn](x)/dx = 0 where J= Bessel function of the first kind
                     [1,0]=3.83, [1,1]=1.84, [1,2]=3.05, [2,0]=7.02, [2,1]=5.33, [2,2]=8.54, [3,0]=10.17, etc.
c= speed of light in the cavity inner medium
lambda=free space wavelength c/f such that lambda<cutoff wavelength
a =smaller end plate's radius
b= larger end plate's radius
Title: Re: EM Drive Developments
Post by: Mulletron on 11/30/2014 08:33 pm
Dispersion, like rainbow dispersion? Interesting.....

How does dispersion work with a CW spike operating in a single mode? I need to take a moment with a Twix.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/30/2014 09:15 pm
Dispersion, like rainbow dispersion? Interesting.....

How does dispersion work with a CW spike operating in a single mode? I need to take a moment with a Twix.

That is the question.
Title: Re: EM Drive Developments
Post by: Mulletron on 11/30/2014 09:17 pm
Please forgive my ignorance. This is a new way of thinking for me. So do you mean dispersion due to doppler frequency shifting inside the cavity due to acceleration of the cavity? Maybe? Trying to grasp what you're saying is all.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 11/30/2014 09:29 pm
Please forgive my ignorance. This is a new way of thinking for me. So do you mean dispersion due to doppler frequency shifting inside the cavity due to acceleration of the cavity? Maybe? Trying to grasp what you're saying is all.

Exactly, I'm fishing around to see what the relationship is (if any) between a cavity w/ an asymmetric dispersion relation and the accelerated frame of reference that balances it via doppler shifts.

Pretty crude at the moment.

I just used the relation for a cylindrical wave guide to get those.  It would be nice to have the full vector dispersion for the cavity to start,  but    ,   time, time.

 
Title: Re: EM Drive Developments
Post by: Mulletron on 11/30/2014 09:57 pm
Given the permittivity and permeability of free space, I wonder how a spontaneously anisotropic vacuum could effect dispersion, eg vacuum dispersion.

The reason I'm saying this is linked to below. Seems like I have vacuum on the brain now days. It can do anything!  :)
http://arxiv.org/abs/1302.6165

The other reason I'm saying that is because the acceleration thing doesn't "resonate"  8) with me because the cavity sitting on the bench isn't accelerating wrt any observers. But there are other ways to get dispersion besides acceleration induced doppler shifts.

Edit: added a link with explanation.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 11/30/2014 10:05 pm
You are joking of course....
The lab setup is accelerating in most observers rf...
Title: Re: EM Drive Developments
Post by: Rodal on 11/30/2014 10:13 pm
the cavity sitting on the bench isn't accelerating wrt any observers
It all depends on how small an acceleration one is considering, as astronomers need to subtract time-varying Doppler shifts due to Earth's changing velocities if they are interested in equal or smaller changes due to the actual motions of the stars.  For example,

1) the centripetal acceleration at the Equator is about 0.034 m/sec^2  (0.3% of the gravitational acceleration g). 

2) The centripetal acceleration of the Earth around the Sun is 0.0059 m/sec^2 (0.06 % of the gravitational acceleration g).

3) The centripetal acceleration required for our  Sun and solar system to orbit the center of our galaxy is very  small: 1.9*(10^(-10)) m/sec^2.

Title: Re: EM Drive Developments
Post by: Mulletron on 11/30/2014 10:35 pm
So regardless of how dispersion comes about....dispersion is the key thing here though right? Or is the AFR the key thing here? I'm re-reading all of Notsosureofit's posts. Seeing a lot about AFRs there. 
Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/01/2014 12:01 am
But there are other ways to get dispersion besides acceleration induced doppler shifts.


Yes, you might expect to see some from the energy loss while the NASA cavity is loading the spring, or from Shawyers rotating rig.  Any non-linearity.
Title: Re: EM Drive Developments
Post by: Rodal on 12/01/2014 02:20 am
the cavity sitting on the bench isn't accelerating wrt any observers
It all depends on how small an acceleration one is considering, as astronomers need to subtract time-varying Doppler shifts due to Earth's changing velocities if they are interested in equal or smaller changes due to the actual motions of the stars.  For example,

1) the centripetal acceleration at the Equator is about 0.034 m/sec^2  (0.3% of the gravitational acceleration g). 

2) The centripetal acceleration of the Earth around the Sun is 0.0059 m/sec^2 (0.06 % of the gravitational acceleration g).

3) The centripetal acceleration required for our  Sun and solar system to orbit the center of our galaxy is very  small: 1.9*(10^(-10)) m/sec^2.

And what is the acceleration measured by NASA Eagleworks?

acceleration = 55 microNewtons / mass

say that the mass was 20 lbm, then the acceleration was:

acceleration = (55*10^(-6) kg m / sec^2) / (20 lbm * 0.453592 kg / lbm) = 6 * 10^(-6) m/sec^2

                    = 0.00018 of the Earth's centripetal acceleration at the Equator
                    = 0.0010 of the centripetal acceleration of the Earth around the Sun
                    = 32000 times  the centripetal acceleration required for our  Sun and solar system to orbit 
                        the center of our galaxy

In other words, the acceleration measured by NASA is less than 1/5000 times the  Earth's centripetal acceleration at the Equator, and 1/1000 times the  Earth's centripetal acceleration around the Sun , so with respect to an observer at the pole the EM Drive at NASA was already accelerating "sitting at the table" and the tiny acceleration measured by NASA Eagleworks was an insignificant change in acceleration compared to its pre-existing centripetal acceleration due to the Earth's rotating around its own axis.

This is what we are dealing with here: an experiment at NASA Eagleworks where only 2.6 watts of input power was applied to obtain a tiny force of only 55 microNewtons: an acceleration so small that even the centripetal acceleration of the Earth around the Sun is larger than it.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/01/2014 02:40 am
Quote
the cavity sitting on the bench isn't accelerating wrt any observers

Well I concede it is accelerating wrt observers after you turn it on. Gotta look at cause and effect here.

That was a good analysis. I wish you could run your math wizardry on my "unpossible" post from yesterday.

Here's what I'm looking at:

So Molly is an electron in the dielectric, Chris and Jim are a bunch of random vacuum fluctuations. Will and Richard Grieco (not shown  :() are photons of the RF EM waves. Will and Richard Grieco only dance when "What is Love" is playing when RF is turned on. The dance club is a new place called Copper Conical Frustum. The idea here is to get Chris to dance harder than Jim. I want Molly to dance across the room. Instead of being buffeted in the middle, like what usually happens over at The China Club.  ;)

(http://img.pandawhale.com/69437-night-at-the-roxbury-bouncing-bc2C.gif)

http://www.nasa.gov/centers/glenn/technology/warp/possible.html
"It has also been suggested by Millis that any asymmetric interactions with the vacuum energy might provide a propulsion effect."
#vacuum polarization #zitterbewegung
Disclaimer: I promise I wasn't tanked while writing this analogy. Just trying to communicate a concept in a hilarious thought provoking way.
Title: Re: EM Drive Developments
Post by: Rodal on 12/01/2014 01:17 pm
Quote
the cavity sitting on the bench isn't accelerating wrt any observers

Well I concede it is accelerating wrt observers after you turn it on. Gotta look at cause and effect here.

That was a good analysis. I wish you could run your math wizardry on my "unpossible" post from yesterday.

Here's what I'm looking at:

So Molly is an electron in the dielectric, Chris and Jim are a bunch of random vacuum fluctuations. Will and Richard Grieco (not shown  :() are photons of the RF EM waves. Will and Richard Grieco only dance when "What is Love" is playing when RF is turned on. The dance club is a new place called Copper Conical Frustum. The idea here is to get Chris to dance harder than Jim. I want Molly to dance across the room. Instead of being buffeted in the middle, like what usually happens over at The China Club.  ;)


http://www.nasa.gov/centers/glenn/technology/warp/possible.html
"It has also been suggested by Millis that any asymmetric interactions with the vacuum energy might provide a propulsion effect."
#vacuum polarization #zitterbewegung
Disclaimer: I promise I wasn't tanked while writing this analogy. Just trying to communicate a concept in a hilarious thought provoking way.

Direction-biased random walks:
http://demonstrations.wolfram.com/DistributionsInDirectionBiasedRandomWalk/

Biased random walks:

https://www.youtube.com/watch?v=IZaAUwW7OsU

Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/02/2014 11:50 am
Found dumb error, update by weekend, thanks for patience
Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/02/2014 08:36 pm
OK, third time is the charm (same error only twice) on the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator to 1st order using massless, perfectly conducting cavity. Quickie calculation to rotate waveguide into doppler frame for acceleration g.

g = (X[subm,n])^2*(c/4*pi^2)*lambda^2*((1/a^2)-(1/b^2))

where a anb b are the end plate radii and the X are the Bessel function zeros.

X[subm,n] = m-th root of dJ[subn](x)/dx = 0

[1,0]=3.83, [1,1]=1.84, [1,2]=3.05, [2,0]=7.02, [2,1]=5.33, [2,2]=8.54, [3,0]=10.17, etc.

Lambda < cutoff wavelength.

Lambda is the free space wavelength c/f.

giving thrust per photon:

T = (X[subm,n])^2*(h/4*pi^2)*lambda*((1/a^2)-(1/b^2))

If the number of photons is power * Q / hf then I should be able to try some numbers.

T = P*Q*(X[subm,n])^2*(1/c*4*pi^2)*lambda^2*((1/a^2)-(1/b^2))

TM211 T=9.84e-5 vs 9.12e-5 P=16.9 Q=7320
TM211 T=2.39e-4 vs 5.01e-5 P=16.7 Q=18100
TE012 T=1.32e-4 vs 5.54e-5 P=2.6  Q=22000

Close enough for gummint work ?

So if you have the dispersion relation for any cavity, can you now directly calculate Thrust (force ?) as GR ??

Edit: Does it also mean, as in the acoustic case, that you can optimize the cavity shape ?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/02/2014 10:39 pm
I like this without checking... I trust you.
Title: Re: EM Drive Developments
Post by: Rodal on 12/02/2014 10:55 pm
OK, third time is the charm (same error only twice) on the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator to 1st order using massless, perfectly conducting cavity. Quickie calculation to rotate waveguide into doppler frame for acceleration g.

g = (X[subm,n])^2*(c/4*pi^2)*lambda^2*((1/a^2)-(1/b^2))

where a anb b are the end plate radii and the X are the Bessel function zeros.

X[subm,n] = m-th root of dJ[subn](x)/dx = 0

[1,0]=3.83, [1,1]=1.84, [1,2]=3.05, [2,0]=7.02, [2,1]=5.33, [2,2]=8.54, [3,0]=10.17, etc.

Lambda < cutoff wavelength.

Lambda is the free space wavelength c/f.

giving thrust per photon:

T = (X[subm,n])^2*(h/4*pi^2)*lambda*((1/a^2)-(1/b^2))

If the number of photons is power * Q / hf then I should be able to try some numbers.

T = P*Q*(X[subm,n])^2*(1/c*4*pi^2)*lambda^2*((1/a^2)-(1/b^2))

TM211 T=9.84e-5 vs 9.12e-5 P=16.9 Q=7320
TM211 T=2.39e-4 vs 5.01e-5 P=16.7 Q=18100
TE012 T=1.32e-4 vs 5.54e-5 P=2.6  Q=22000

Close enough for gummint work ?

So if you have the dispersion relation for any cavity, can you now directly calculate Thrust (force ?) as GR ??

Edit: Does it also mean, as in the acoustic case, that you can optimize the cavity shape ?

(http://media3.giphy.com/media/jShr8wkP38XTO/giphy.gif)
Title: Re: EM Drive Developments
Post by: Mulletron on 12/03/2014 04:34 am
The Dr. White QV thrust model got a down peer review.

http://arxiv.org/abs/1411.5359

As I've said. It is best to not try and push on the QV. Let me count the ways.
1. Violation of conservation of energy AND momentum.
2. A measly 7.7751e-6 eV / 1.2457e-24 Joules of energy of a photon at 1880mhz is puny compared to estimates of the vacuum energy density.
3. A photon interaction with virtual particles is the stuff of high energy lasers, not low power microwaves. As is virtual particle pair production.
4. A vacuum fluctuation particle pair is both created an annihilated before ever leaving the cavity. So no wake can ever be measured.

The QV is already pushing on you in all directions at once, netting to zero momentum gained.

Instead let it push on you, in a direction biased in the direction you want to go. You achieve this by providing asymmetric radiation pressure on the atoms inside the cavity. Those atoms are in turn, what is interacting with the QV.

I agree with the paper in most respects, yet I note that the author didn't take into account the asymmetric RF environment inside the cavity nor the squeezed vacuum state within the cavity. The author's approach was essentially modeling the Dr. White conjecture in open air.

Neat tools to make things easier:
http://www.1728.org/freqwave.htm
https://www2.chemistry.msu.edu/faculty/reusch/virttxtjml/cnvcalc.htm

Interesting article:
http://davidaroffman.com/custom3_11.html

Put on a helmet first:
http://www.iesc-proceedings.org/articles/iesc/pdf/2012/01/iesc_qed2012_02004.pdf
Title: Re: EM Drive Developments
Post by: Mulletron on 12/03/2014 04:39 am
OK, third time is the charm (same error only twice) on the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator to 1st order using massless, perfectly conducting cavity. Quickie calculation to rotate waveguide into doppler frame for acceleration g.


Quote
Quoting Rodal.
1) What is the actual acceleration (formula used for acceleration and variables inside it)  of the accelerating frame of reference under your consideration?

2) Defining thrust force of a rocket to be in the same direction as the motion of the rocket, what is the direction of the thrust force according to your EM drive formula? Is it directed towards the small end or towards the large end?

3) For your formula, does it make a difference whether the cavity's mode is TE (outer circumferentially electric with an inner axial magnetic field) or TM (outer circumferentially magnetic with an inner axial electric field) ?

4) So the proposition that an accelerating frame of reference caused by a dispersive cavity resonator gives you a net thrust (as long as the ends have different diameter) proportional to Q even though there are no photons escaping the cavity?  What is the explanation for conservation of momentum? That one has to consider an open system because of the accelerating frame of reference?

Would you mind answering these questions presented earlier? Particularly question 4. Are you interacting with anything that is outside of the cavity?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/03/2014 12:00 pm
OK, third time is the charm (same error only twice) on the proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator to 1st order using massless, perfectly conducting cavity. Quickie calculation to rotate waveguide into doppler frame for acceleration g.


Quote
Quoting Rodal.
1) What is the actual acceleration (formula used for acceleration and variables inside it)  of the accelerating frame of reference under your consideration?

2) Defining thrust force of a rocket to be in the same direction as the motion of the rocket, what is the direction of the thrust force according to your EM drive formula? Is it directed towards the small end or towards the large end?

3) For your formula, does it make a difference whether the cavity's mode is TE (outer circumferentially electric with an inner axial magnetic field) or TM (outer circumferentially magnetic with an inner axial electric field) ?

4) So the proposition that an accelerating frame of reference caused by a dispersive cavity resonator gives you a net thrust (as long as the ends have different diameter) proportional to Q even though there are no photons escaping the cavity?  What is the explanation for conservation of momentum? That one has to consider an open system because of the accelerating frame of reference?

Would you mind answering these questions presented earlier? Particularly question 4. Are you interacting with anything that is outside of the cavity?

At the moment I'm just looking at the math relationship between a cavity dispersion relation and the "thrust" magnitude.  I think interesting cases to look at are the hemisphere and the dumbell if I can find those curves.  There is a 4-vector relationship but I don't want to speculate.  If I get any great insight I'll let you know.
Title: Re: EM Drive Developments
Post by: Rodal on 12/03/2014 12:22 pm
The Dr. White QV thrust model got a down peer review.

http://arxiv.org/abs/1411.5359

....

Great find !
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/03/2014 02:07 pm
Not really peer review.  arxiv is the peerless reviewless.  But a useful place to find quick opines.  You'll find lots of terrible nonsense on arxiv, but you'll also find all sorts of pre-peer review stuff and all the guys from the national labs use it.  It also has a lot of crank stuff that would never make it into any peer review journal, so you need to be careful.
Title: Re: EM Drive Developments
Post by: Rodal on 12/03/2014 02:33 pm
Not really peer review.  arxiv is the peerless reviewless.  But a useful place to find quick opines.  You'll find lots of terrible nonsense on arxiv, but you'll also find all sorts of pre-peer review stuff and all the guys from the national labs use it.  It also has a lot of crank stuff that would never make it into any peer review journal, so you need to be careful.
I agree from a strict point of view concerning the strict definition of peer-review, but I think that Mulll meant that a peer (another scientist or engineer), reviewed Dr. White's proposal and debunked it, which is also a true statement.  Anyone can publish in arxiv: the papers in arxiv are not reviewed by anyone.  Recently they added a requirement which (if I recall correctly) is that to publish in arxiv one needs to get endorsements from just two authors that have already published a few papers at arxiv.  Arxiv has a disclaimer that this is not peer-review of course, and just a way to reduce the huge number of submissions to arxiv.  Meanwhile a lot of the authors that got to publish in arxiv during the past few years without any endorsements, can continue to publish whatever they want in arxiv without any peer review or any endorsements.

What is even more concerning is that arxiv also admits that authors in arxiv may NOT have a relationship to the institution they claim to be associated with, as apparently arxiv does not check whether the author claim of institution association is correct (the institution as well as the author's name, etc., are just fields entered by the submitter).  The only thing checked by arxiv appears to be the e-mail of the submitter.  So, apparently unsophisticated robots are not arxiv authors  ;).

On the other hand "peer review" is not what it used to be.  It used to be that there were a few major journals and they had strict peer review and papers were turned down regularly.   Then the number of journals grew explosively and authors simply just published in less well known and newer journals with less strict requirements.

What I really appreciated and I see less and less of is open (rather than blind) peer-review.  It used to be that papers published in journals were criticized in public.  Journals had a section where articles could be criticized and it was up to the author to answer the criticism.  This practice was fairly common in the 1920's through 1950's.  This uncovered a lot of errors and it was a great practice.  It was very enjoyable to see arguments between major scientists (for example Einstein vs. Bohr).

A great example is when Pauli replied to Landau, "What you said was so confused that one could not tell whether it was nonsense or not."

Nowadays there are only a few journals that keep this practice.

So, when authors nowadays publish in journals that supposedly are "peer-reviewed" but the journal does not have a section where other authors can criticize the paper, it really does not mean that much.  Particularly when authors publish physics papers that are not cited, that is: they are ignored by the general physics community. 

Citation has become a very important metric.

 
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/03/2014 02:55 pm
Agreed.  Too note that we've developed a tiered system to some degree which is not really in keeping with the spirit of the thing.  If someone can write a paper that is to the standards of their peers, it should be reviewed.  Instead, the standard was changed from that of the peers--usually those holding PhD's in their fields, which is the sheepskin that says you're qualified to do independent research--to the standards of any particular journal, which is moving the goal posts for snobbish and self-interested reasons.  Journal editors have taken to priding themselves in what they turn away, rather than in the quality of their analysis.  This is a serious problem.  Snobbery is really destructive to what makes good science.

As bad as it gets though, there is nothing to replace the high level analysis that happens in peer review journals.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/04/2014 01:05 am
http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA426465

This is an Air Force study I found. The PDF is messed up a little. Just zoom out to find the pages. Chapter 4 sure sounds familiar.....Pages 58-63.

They went ahead and threw gravity, inertia and c in there. Wouldn't that be a neat little bundle if the QV were responsible for all that.
I never thought I would see this stuff echoed in an Air Force study.

Is the answer to life, the universe and everything actually 376.73031?

I'm enjoying the mathematical coincidence of 120pi.
Title: Re: EM Drive Developments
Post by: SpoCk0nd0pe on 12/04/2014 01:50 am
Just a quick question because it can be kind of hard to find this:
Has there been any news on experimental followups to the summer paper that got so much attention? How long would you expect it to take?

Thanks in advance!
Title: Re: EM Drive Developments
Post by: Mulletron on 12/04/2014 03:22 am

No, sorry, the answer to life, the universe and everything is not 376.73031

Don't view  this report as an Air Force internal study.  Rather, it is an AFRL contract report.  The author of the contract report apparently has also made controversial statements regarding UFOs (he is quoted as saying UFOs Are "Supremely Advanced Technology") according to the following links and YouTube video:

http://www.theufochronicles.com/2013/05/ufo-research-by-nasa-affiliated.html

http://www.reddit.com/r/UFOs/comments/1ed8uo/dr_eric_w_davis_of_nasas_breakthrough_propulsion/

http://massufosightings.blogspot.com/2013/07/exopolitical-disclosure-dr-eric-w-davis.html


Seems he must be pretty legit if the AF put him on contract, and actually allowed it to be published. Regardless of his views on aliens....(nice try).

He was a key player in the original Nasa Breakthrough Propulsion Physics Project.

http://www.wpafb.af.mil/AFRL/

More about the author:
http://lifeboat.com/ex/bios.eric.w.davis
http://www.icarusinterstellar.org/team/eric-davis/
http://www.tauzero.aero/about/who/#TAU%20ZERO%20PRACTITIONERS

From the abstract:
"The study also reviewed and evaluated a select number of credible far-term breakthrough
propulsion physics concepts pertaining to R&D work done on or related to gravity/inertia modification, spacetime metric modification, and the extraction of energy from the space vacuum environment."

It seems we're entering an era of postmodern physics, where old dogmas which limit inquiry are melting away. So many important questions remain to be answered. We've been given concepts like gravity, inertia, and c, and told how they work to great detail; but never adequately told why... The same answers for all three, they are because they just are. That pervasive attitude serves to limit our progress forward. If this EMdrive proves to be successfully reproduced over and over again; those old dogmas are history  :) Finally guys like Puthoff, Haisch and Davis; those who dare to question everything and go against the grain, will get a voice.

Case in point. I've known for many years that the impedance of free space is 377ohms. The point of a feed horn is to match a waveguide to the impedance of free space. Yet I never questioned why it is 377ohms. It turns out the reason is because the "vacuum" isn't really a vacuum at all. It has a complex structure, and behaves as a dielectric, and is the actual reason why light travels at the speed it does.
Title: Re: EM Drive Developments
Post by: Stormbringer on 12/04/2014 03:22 am
wut?
Title: Re: EM Drive Developments
Post by: Mulletron on 12/04/2014 03:58 am
Just a quick question because it can be kind of hard to find this:
Has there been any news on experimental followups to the summer paper that got so much attention? How long would you expect it to take?

Thanks in advance!

Welcome to the forum. No clue. We're all chomping at the bit for official word.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/04/2014 02:27 pm
Don't view  this report as an Air Force internal study.  Rather, it is an AFRL contract report.  The author of the contract report apparently has also made controversial statements regarding UFOs (he is quoted as saying UFOs Are "Supremely Advanced Technology") according to the following links and YouTube video

In the interests of full disclosure let me preface my comments here by noting Eric is a friend of mine.  Indeed yes, the study was commissioned through another contractor, Frank Mead (recently retired) who had been a staple at Wright Patterson AFRL for decades.  This is not to say USAF didn't have an interest.  They commissioned the study.  They cannot of course endorse Eric's view of UFO's because USG has set policy in this regard and until that changes, any interest USAF has concerning things like teleportation (which was the real focus of the study and was redirected to wormhole physics) has to be pursued through contractors.  And I'd just note to you, the smartest guys at AFRL, are definitely the much better paid contractors.

That all said, Eric is a committed ZPFer and we completely disagree concerning what is at the core of this high tech stuff.  Eric works at Earthtech, which is Hal Puthoff's lab down in Austin.  Hal is one of the three guys who started the ZPF fuss when they published on stochastic electrodynamics and the polarizable vacuum back in the 90's (I believe it was the 90's).  Hal was also one of three scientists who originally working for NRO and later CIA, developed the US's psychic spy program that was later turned over to CIA and became the "Stargate" program.  One of the three guys who developed the protocols for that, which is what made it work to some small degree but was not useful; is another friend of mine, Christopher "Kit" Green.  Puthoff is as near a legendary physicist as one could hope to find.  He does great work, but I personally think the ZPF stuff is wrong. 

And FYI, nearly everyone in the intelligence community that has anything whatsoever to do with energy and propulsion physics, believes just as Eric Davis believes--that we really did recover something amazing at Roswell.  And these guys don't believe this stuff because they're quixotic, or delusional or having hallucinations.  They believe it based on fact.  So be careful what you say about them.  Painting them as whackos is really just a USG propaganda thing.  I was not myself a believer in any sense, until Kit, who is a senior officer at CIA who manned the desk for ten years looking into this stuff; challenged me to use my critical thinking skills as a philosopher and look carefully at the evidence.  I did that, and became a "believer" in UFO's too.  I doubt anyone can look at the evidence objectively, and not come to the conviction that UFO's are indeed visiting spacecraft. And despite the official policy of the US armed forces, EVERYONE involved believes in UFO's.  Everyone.  Half the guys involved claim to have seen the craft, including Hal Puthoff.  According to Kit though, no one really understands how they work, and that's because they're trying to apply ZPF theory to them when they ought to be applying M-E theory to them.  They're AC propulsion systems, so it ought to be obvious this is M-E, not ZPF.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/04/2014 02:53 pm
But if that picture cannot be reproduced regularly, at different times, viewing angles, lighting conditions, and so forth, how could it be called remote viewing?

Answer: Analytical overlay.  Without corect analysis, the data is useless.

The data is useless regardless.  It's not the analysis that is the problem.   It's that the images have no context.  It does not help to have a remote viewer actually see a pair of planes flying into the twin towers ten years in advance, when there is no detail of when this will happen.  And in fact, there is every reason to believe there is no way to change the future by acting on this kind of intel.  The future is really out there.  What is going to happen will happen or we could not view it.  CIA declassified the program because although interesting, it was useless.  Some of the participants seem to be earning decent livings helping police departments track down missing children and the like, but other than that, there is no value in remote viewing, apart from informing religion.  This seems to be the same stuff the prophets of old did.

Quote
At 30:25 or so, the lecturer talks about Ed, the scambuster, sent by the CIA to vet the results of the experimentors.  Turns out, part of the procedure was a previous list of various sites kept in envelopes in a safe.  The sites were chosen at random from a previously made list.  This is not random enough.

Random is not the point.  The point is to make the study double blind.  It is the protocols like this that make the study and practice so interesting.  When you look at the PEAR lab results from Princeton, they're unconvincing because they were not nearly as careful with their protocols.  The work Hal, Kit and Russel did is convincing because they were much more careful.  Doesn't matter though.  You can't change the future by acting on this kind of information because it has no context.  Prophets and viewers all see as if looking at a mountain range.  They can see the peeks but not the valleys, and they have no apprehension of the distance between one peek and the one seemingly just behind it.  It could be a week away, a month, a year, a millennia.  You can't act on information like this.
Title: Re: EM Drive Developments
Post by: SpoCk0nd0pe on 12/04/2014 03:22 pm
Just a quick question because it can be kind of hard to find this:
Has there been any news on experimental followups to the summer paper that got so much attention? How long would you expect it to take?

Thanks in advance!

Welcome to the forum. No clue. We're all chomping at the bit for official word.
Thanks!

I must say though, that I'm not too fond of the reactions the paper evoked. The test were meant to have a quick look at it, the paper clearly states that further throughout lab testing is needed. The quick look was positive but by no means proofed a new effect.

The hateful reaction (of theoretical physicists) is really counter productive. Often in modern science people try to defend the big, long, ongoing projects because their jobs depend on it. Not to say those projects do not create results but they often drain the funding for alternative approaches that may be much cheaper to look at while some times creating no results themselves. Besides, theoretical physicists have their own skeletons in their closets, e.g. with all the popular black hole talk they hide that there can practically be no event horizon because it would take forever to form (infinite gravitational time dilatation) from our observation standpoint.

On the other hand the ones overstating the results risk the cold fusion fiasco. If this doesn't work, it could cost some scientists who where merely willing to take a look their career. It would also strengthen people trying to put a boot on other people who just try stuff. Sometimes science is about trying new stuff, that shouldn't be forgotten.

Sorry for my bumpy English, eagerly waiting for new lab results on this!
Title: Re: EM Drive Developments
Post by: momerathe on 12/04/2014 04:42 pm
The hateful reaction (of theoretical physicists) is really counter productive.

The problem is that, to paraphrase Nima Arkani-Hamed, it's really hard to come up with something that's not obviously wrong.

Regardless of whether it works or not, many of the explanations* that have been put forward, like Shawyer's original EM Drive paper, are just nonsense. And I'm not talking about whether they disagree with known physics, people are pretty relaxed about that, rather the authors don't even understand the physical theories that they're employing to base their claims on. That's what gets peoples' backs up.

* Woodward, having an internally consistent theory (though I wouldn't put any money on it), being an exception to this.

Quote
Often in modern science people try to defend the big, long, ongoing projects because their jobs depend on it. Not to say those projects do not create results but they often drain the funding for alternative approaches that may be much cheaper to look at while some times creating no results themselves.


really? funding conspiracy? that's where you're going with this?

Quote
Besides, theoretical physicists have their own skeletons in their closets, e.g. with all the popular black hole talk they hide that there can practically be no event horizon because it would take forever to form (infinite gravitational time dilatation) from our observation standpoint.

that's.. not how it works.

I mean; there are plenty of brickbats you could throw at theoretical physics with great justification (the unfalsifiability of string theory, for example), but you've picked a really bad one here.
Title: Re: EM Drive Developments
Post by: SpoCk0nd0pe on 12/04/2014 06:42 pm
I really don't know enough about physics to comment on the theoretical part. As a matter of fact it doesn't really matter imho as this could just be a new effect. Even saying that it contradicts known theories and there is no theory that harmonizes the results with conversation of momentum is completely legitimate. But calling the findings bs because they are "impossible" is too far fetched imho. The findings have to be verified or falsified by further experiments, that's it.

I'm not into conspiracy theories, I'm not saying that funding is the main reason for the hate. But I'm saying that it can produce questionable politics in the science community that hinder the science.

About the black hole stuff: My physics stopped at 10th grade school (we did some basic concepts of relativity though) but still raised the question of gravitational time dilatation. Because I don't know more, I wrote to three physicists with the question and they all told me the same thing.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/04/2014 07:23 pm
Posting these videos of remote viewing and alien conspiracy junk are simply ad hominem attacks directed to discredit these individuals. The fact is, these men, were (and still are) key players in the advanced propulsion research community and worked in the industry. They contributed to the original original Nasa Breakthrough Propulsion Physics Project. Their side projects or beliefs in other esoteric phenomena has no bearing on this subject. If they choose to stare at goats, fine, whatever. If they choose to come up with ideas based on eyewitness reports of strange craft doing strange things(Eric Davis video 37:20), so be it. Those little green men  :o have to obey the same laws of physics we do (tongue in cheek). So it is probably a good idea to throw a critical eye at those reports, and think about the physics that could be behind it. Just in case. :) The underlying science is there to support it. Yes I find it curious that, if you follow these gentlemen's stories down the rabbit hole, they are all in one way or another, connected to some really strange stuff.

https://www.youtube.com/watch?v=xDx1po_apZU#t=2241
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/04/2014 07:40 pm
The book is actually very good,

http://www.amazon.com/Frontiers-Propulsion-Progress-Astronautics-Aeronautics/dp/1563479567

but I would note that it is as most studies of its kind, completely dominated by the ZPF concept.  Since Millis was first tasked to do the BPP study, all of advanced propulsion here in the US has been in the pocket of the ZPFers.  This is for many reasons, but it is good to note that Woodward did have an opportunity to publish in this and chose not to.  He didn't have the time, so he asked Paul March to write something for Davis and Millis, and Paul was too busy.  Then Paul and Jim both asked me to write something and I did not feel I have the technical expertise required for that venue.  So a tiny blurb was offered by Martin Tajmar which hardly does the subject justice. 

From reading this book, you would suppose that ZPF is the whole hope, and M-E is a side bet, but in fact there has been vastly more M-E research done over the years than all the ZPF stuff combined, and it has been hugely successful by comparison.  You don't get that from reading this book.  The authors who published here, had the time to write these essays because they aren't busy every day in the lab, the way Woodward is.
Title: Re: EM Drive Developments
Post by: RanulfC on 12/04/2014 08:36 pm
Posting these videos of remote viewing and alien conspiracy junk are simply ad hominem attacks directed to discredit these individuals. The fact is, these men, were (and still are) key players in the advanced propulsion research community and worked in the industry. They contributed to the original original Nasa Breakthrough Propulsion Physics Project. Their side projects or beliefs in other esoteric phenomena has no bearing on this subject. If they choose to stare at goats, fine, whatever. If they choose to come up with ideas based on eyewitness reports of strange craft doing strange things(Eric Davis video 37:20), so be it. Those little green men  :o have to obey the same laws of physics we do (tongue in cheek). So it is probably a good idea to throw a critical eye at those reports, and think about the physics that could be behind it. Just in case. :) The underlying science is there to support it. Yes I find it curious that, if you follow these gentlemen's stories down the rabbit hole, they are all in one way or another, connected to some really strange stuff.

As an aside but on THIS subject we need to recall that in the 1950s it was generally assumed that we were going to find out how to control gravity and other "super-science" stuff "any-day-now" to the point where a serious engineer who wrote fiction based his "Advanced Interstellar Spacecraft" on being a "flying saucer" for the simple fact that the one then currently "visting" Earth (it seemed) were obviously using them :)
http://www.amazon.com/Starship-Through-Space-Lee-Correy/dp/B000H77B62

http://www.rogersrocketships.com/page_view.cfm?id=69

So its not too far fetched to see where belief in some aspects of what is considered "fringe" science can lead to other beliefs and still not effect the basic knowledge and understanding of the individual :)

We as species and individuals need to understand that we really do NOT fully understand the universe... Yet. But we're getting there slowly but surely :)

Randy
Title: Re: EM Drive Developments
Post by: Stormbringer on 12/04/2014 08:44 pm
Sooner or later someone from the fringe will do something that will stick. In the mean time i vote we all load up in cars and go kick John huchinson's (Beep) for being such a sloppy experimentalist and doofus he discovered and lost antigravity and van der wahls force manipulation by not taking notes and remembering how he did it. :)
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/04/2014 09:17 pm
As an aside but on THIS subject we need to recall that in the 1950s it was generally assumed that we were going to find out how to control gravity and other "super-science" stuff "any-day-now". . .

There was a lot of really interesting physics in the 50's, and in particular, Dennis Sciama's work that Woodward picked back up.  There was in fact a kind of "saucer craze" back then when people talked about anti-gravity and flying saucers and really thought we were entering the space age.  All that came to a grinding halt when the Condon report came out in 1968, and that entire report was fraudulent, from start to finish.  There are several modern books that examine that work, but if you want to point to a specific act by USG toward what is often called a conspiracy, then the Condon report is certainly the smoking gun.  It is one, enormous lie that fomented social change and altered the attitude of the American people for 3 decades.

IIRC, there's an excellent, objective, balanced view of Condon here: 

http://www.amazon.com/UFOs-Generals-Pilots-Government-Officials/dp/0307717089
Title: Re: EM Drive Developments
Post by: aero on 12/05/2014 01:04 am

A request -
I've been looking for dielectric model parameters for the copper of the cavity with no luck. Lots of information on higher frequency behavior. The data I need is probably available under key search words that I am not aware of. I need gamma and sigma, or measurement data from which to calculate them over a frequency centered at 2 GHz and one data point at DC.

frequency,  gamma, sigma
    0             ?            5.9595E+7
    1 GHz      ?              ?
    1.7 GHz   ?              ?
    2.3 GHz   ?              ?
    3  GHz     ?              ?

Those 9 values or a data source where I can find them would solve my problem modeling the copper cavity.

Your help will be appreciated.
Title: Re: EM Drive Developments
Post by: ThinkerX on 12/05/2014 01:46 am
Quote
And FYI, nearly everyone in the intelligence community that has anything whatsoever to do with energy and propulsion physics, believes just as Eric Davis believes--that we really did recover something amazing at Roswell.  And these guys don't believe this stuff because they're quixotic, or delusional or having hallucinations.  They believe it based on fact.  So be careful what you say about them.  Painting them as whackos is really just a USG propaganda thing.  I was not myself a believer in any sense, until Kit, who is a senior officer at CIA who manned the desk for ten years looking into this stuff; challenged me to use my critical thinking skills as a philosopher and look carefully at the evidence.  I did that, and became a "believer" in UFO's too.  I doubt anyone can look at the evidence objectively, and not come to the conviction that UFO's are indeed visiting spacecraft. And despite the official policy of the US armed forces, EVERYONE involved believes in UFO's.  Everyone.  Half the guys involved claim to have seen the craft, including Hal Puthoff.  According to Kit though, no one really understands how they work, and that's because they're trying to apply ZPF theory to them when they ought to be applying M-E theory to them.  They're AC propulsion systems, so it ought to be obvious this is M-E, not ZPF.

Years ago, I used to be very interested in UFO's.  Read piles of books on the topic, with authors ranging from vehement skeptics proclaiming all such phenomena to be delusion or otherwise explainable to wide eyed true believers whose rants made them sound like escapees from an asylum.  I eventually decided there were too many giant ego's among the investigating factions, each determined to put forth their own vision at the expense of actual, credible investigation.  Said ego-cases ranged from arch-skeptics to true believers.  Those who attempted anything resembling an unbiased, serious investigation promptly got denounced by the other factions.

One of the few who did impress me with at least an attempt at scientific investigation was Paul Hill.  I found his 'Unconventional Flying Objects' to be both fascinating and incomprehensible (maybe Mulletron or Fornaro or Rodal could make something of the equations, as they may be relevant here).




Title: Re: EM Drive Developments
Post by: Mulletron on 12/05/2014 02:50 am
Just in case any folks still aren't convinced, here's old news of actual experimental observations of repulsive forces and dynamical Casimir effects. You can follow the trail right to the papers.

http://www.newscientist.com/article/dn16374-repulsive-quantum-effect-finally-measured.html#.VIEfPsnXV8G
http://www.nature.com/nature/journal/v457/n7226/full/nature07610.html

http://phys.org/news/2011-11-scientists-vacuum.html#nRlv
http://phys.org/news/2011-12-physicists-darkness-breakthrough-discovery.html#nRlv
http://www.nature.com/nature/journal/v479/n7373/full/nature10561.html

http://phys.org/news/2013-02-particles-illuminate-vacuum.html#nRlv
http://www.pnas.org/content/110/11/4234.abstract

The existence of the QV and its effects is experimentally verified. Starting with attraction between plates (old news), repulsive forces and dynamical effects linked to above.

Utilizing the properties of the QV for propulsion is no longer a theoretical problem. It is an engineering problem. The "anomalous thrust...." devices were likely the "Chicago Pile" of what is to come.

Bonus material from the real interaction side of matter:
http://arxiv.org/pdf/1204.6617.pdf
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.230402

https://courses.physics.illinois.edu/phys596/fa2011/StudentWork/team9_final.pdf
Title: Re: EM Drive Developments
Post by: Stormbringer on 12/05/2014 04:05 am
you guys are confusing me.
Title: Re: EM Drive Developments
Post by: ThinkerX on 12/05/2014 07:02 am
Quote
you guys are confusing me.

Welcome to the club.  But as my posts make clear, I live in a world of confusion.

That said...

Mulletron seems to be auditioning to join the Eagleworks team...or found a competing operation, with the QV approach. 

Rodal is skeptical of Mulletrons approach, and some of his sources.

Ron is less skeptical of Mulletrons sources, but thinks Mulletron is wasting his time, instead promoting Woodward and Mach.

Aero and another poster are running, or attempting to run mathematical models about...energy reactions...inside conical cavities, and whether those energy reactions can produce net thrust.  If the answer is net thrust is possible, and Mulletron somehow validates this, then its time to start rewriting the physics textbooks.  Pesky outdated laws of thermodynamics anyhow:)

And John Fornaro...is John Fornaro...

Title: Re: EM Drive Developments
Post by: Mulletron on 12/05/2014 08:50 am
Quote
you guys are confusing me.

and Mulletron somehow validates this.....

Well I'm no authority to validate anything. I'm here to investigate the facts behind the "anomalous thrust...." paper. I spent a lot of time researching the QV approach that Dr. White says he believes is behind the measured thrust. I arrived at a different mechanism than he did, but the underlying QV approach I have found merit in, and piles of experimental evidence to support the reality that the QV approach is the way forward. I independently arrived at the same conclusions of people who I thought were probably cranks, like Dr. Puthoff for example, and apart from his views on gravity, which I'm agnostic on, I think he was otherwise correct. I'm waiting to see what Aegis has to say.

My mission on here is simply to find the truth. IMHO I think the QV approach is the truth and it has a lot of room to grow and ways to be exploited for good. There is certainly tons more to learn about its nature.

I'm aggravated by the outright denial of information related to the reality of the QV approach, given the sheer volume of information provided supporting it. Literally everything I post here is supported by a paper, and when possible experimental evidence.

The only thing that isn't supported by a paper is the, "the QV is doing the pushing" idea. That is application of theory and admittedly not even close to being well developed.

It would be nice to get everybody on the same page, so we could pool resources and collaborate on a single goal, and I am trying to achieve this by providing overwhelming evidence that this is a real possibility. While being very careful to not fall victim to confirmation bias.

In the end it doesn't matter if I'm right. I hope equally that Ron Stahl is right. The result is equally sweet. In the end, there is no stopping the truth. If the replications keep happening, we'll have our hover cars and starships in due time.

Bonus material:
http://arxiv.org/abs/1303.0914
http://iopscience.iop.org/1367-2630/15/7/073011/pdf/1367-2630_15_7_073011.pdf
Title: Re: EM Drive Developments
Post by: momerathe on 12/05/2014 12:07 pm
Just in case any folks still aren't convinced, here's old news of actual experimental observations of repulsive forces and dynamical Casimir effects. You can follow the trail right to the papers.

[...]

The existence of the QV and its effects is experimentally verified. Starting with attraction between plates (old news), repulsive forces and dynamical effects linked to above.

Utilizing the properties of the QV for propulsion is no longer a theoretical problem. It is an engineering problem.

The existence of the quantum vacuum is not in doubt; nor the casimir force; not the dynamical Casimir effect.

None of these things enable the use of the quantum vacuum for propulsion, without an extension to quantum field theory as it is currently understood. So yes, it very much is still a theoretical problem.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/05/2014 01:29 pm
The existence of the QV and its effects is experimentally verified. Starting with attraction between plates (old news), repulsive forces and dynamical effects linked to above.

I'm sorry but this is just not true.  As explained in detail in Woodward's book, QV is not the only explanation for the Casimir Effect.  ZPF and QVF adherents often misrepresent this issue, by claiming the observed data on Casimir Effect is proof that QV exists, but real physicists know this is not true.  The classical explanation for Casimir does not require QVF.  That is merely ONE interpretation.  It is ONE explanation and it is not the one most physicists hold.

You have been scammed.

"Casimir effects can be formulated and Casimir forces can be computed without reference to zero-point energies. They are relativistic, quantum forces between charges and currents. The Casimir force (per unit area) between parallel plates vanishes as alpha, the fine structure constant, goes to zero, and the standard result, which appears to be independent of alpha, corresponds to the alpha → infinity limit," and that "The Casimir force is simply the (relativistic, retarded) van der Waals force between the metal plates."[17]"

http://arxiv.org/abs/hep-th/0503158v1.pdf

http://en.wikipedia.org/wiki/Casimir_effect#Relativistic_van_der_Waals_force

It's interesting that with the dozens of references Davis and Millis make to Casimir in their book, they never reference this fact or paper.  It's not as if they don't know about it.  They do.  They just don't tell the reader.  Likewise it is interesting how Millis repeatedly misrepresents Woodward and Mach in his portions of the book.  For instance, stating that Mach's Principle implies an absolute frame of reference (pg.135), when it does not.   He supplies an endnote claiming to support his offhand comment and the reference is to an enormous anthology (Barbour and Pfister) that says anything but this, and he gives no page reference.

This is the kind of nonsense the ZPFers dabble in every day.  That's how you have been scammed.  It's all just a big scam and this has been going on now for 20 years.

Title: Re: EM Drive Developments
Post by: Mulletron on 12/06/2014 12:31 am
Just in case any folks still aren't convinced, here's old news of actual experimental observations of repulsive forces and dynamical Casimir effects. You can follow the trail right to the papers.

[...]

The existence of the QV and its effects is experimentally verified. Starting with attraction between plates (old news), repulsive forces and dynamical effects linked to above.

Utilizing the properties of the QV for propulsion is no longer a theoretical problem. It is an engineering problem.

The existence of the quantum vacuum is not in doubt; nor the casimir force; not the dynamical Casimir effect.

None of these things enable the use of the quantum vacuum for propulsion, without an extension to quantum field theory as it is currently understood. So yes, it very much is still a theoretical problem.

No new field theory is needed. Just focused application of existing theory. All the theoretical work has already been done. It hasn't been brought under the same roof until now, and seemingly by accident.
The key enablers of QV propulsion in this context are:
1) Asymmetric casimir cavity, which is also operated as an RF resonant cavity.
2) A dielectric material which interacts both with the QV and the RF.

Basically a dielectric in an asymmetric vacuum and RF environment. Be it a resonant cavity on one side of the dielectric slug and open air on the other (Cannae), or a dielectric fully enclosed in an asymmetric resonant cavity (Shawyer).

Take a sealed casimir cavity. By virtue of being sealed, it is also a resonant cavity. Only a finite number of resonant modes can exist within. The walls of this cavity are not parallel. This means that you have a force gradient from large to small end. Not equal like with parallel plates. A radiation pressure differential. A difference of potential. The potential to do work. This is on the vacuum side of the interaction.

Next is the Shawyer approach, with uneven radiation pressure inside the cavity. Another force gradient. Another difference of potential. The potential to do work. This is the RF side of the interaction.

Either of the above happening alone achieves nothing. Movement/thrust would be tantamount to pushing your car from the inside.

Place inside the cavity a dielectric, or something better. The QV is known to interact with matter (vast amounts of evidence posted). RF is known to also interact with matter(vast amounts of evidence posted). This competing interplay of forces on the atoms of the dielectric, IMHO results in a biased random walk of the atoms comprising the dielectric; all atoms at once working together. This at the most fundamental level boils down to a simple momentum vector diagram. All this happening inside the asymmetric resonant cavity is the source of the thrust.

I am keenly aware that these are just words until it is shown exhaustively mathematically. I arrived at these ideas by reading a LOT of scattered material and a lot of preoccupied sleepless nights. I have arrived at this based off of very loose back of the envelope math. Given that the actual value of vacuum energy is a point of controversy and thus doesn't help me much. It is somewhere between extremely large or extremely small. Either way, I know there is vacuum energy difference in potential from the top to the bottom of the cavity and those relative differences are all that matter. From there, after mathematical conversion to momentum, it doesn't take a mathematician to know that the competing vacuum and RF momentum contributions to the dielectric aren't exactly equal. So something has to budge. Also being that we're dealing with an asymmetric resonant cavity, there is a definite sign to the biased random walk, due to the anisotropy of the RF environment inside the cavity.

Or I am just flat wrong.....

The underlying concepts; Casimir effect, vacuum polarization, zitterbewegung predate WWII. All of which are tested and accepted.  ;)

The only thing left is for more replications to happen, and IF they succeed, a salient theory of operation using the established concepts described above needs to be formalized.

This all boils down to what you can do with matter and light when placed within a Casimir cavity.

No new field theory is required. Just new theory of application.

Side note:
If this thing by some miracle also ends up being antigravity, or modified inertia, then we'll need new theory.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/06/2014 12:51 am
It all boils down to what exactly is a Casimir cavity.
Sheets of copper don't qualify. We need a single sheet graphene cavity to understand whats going on.
I say this because bulk copper (or any bulk conductor) is a mess.
Surface effects et al are eliminated.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/06/2014 01:47 am
The existence of the QV and its effects is experimentally verified. Starting with attraction between plates (old news), repulsive forces and dynamical effects linked to above.

I'm sorry but this is just not true.  As explained in detail in Woodward's book, QV is not the only explanation for the Casimir Effect.  ZPF and QVF adherents often misrepresent this issue, by claiming the observed data on Casimir Effect is proof that QV exists, but real physicists know this is not true.  The classical explanation for Casimir does not require QVF.  That is merely ONE interpretation.  It is ONE explanation and it is not the one most physicists hold.

You have been scammed.

"Casimir effects can be formulated and Casimir forces can be computed without reference to zero-point energies. They are relativistic, quantum forces between charges and currents. The Casimir force (per unit area) between parallel plates vanishes as alpha, the fine structure constant, goes to zero, and the standard result, which appears to be independent of alpha, corresponds to the alpha → infinity limit," and that "The Casimir force is simply the (relativistic, retarded) van der Waals force between the metal plates."[17]"


Ok well first thing, VDW forces are the net effect of many forces. You are confusing VDW and Casimir forces. Vacuum forces are one component to VDW forces. After controls are put in place (conducting parallel plates), Casimir forces can be measured independently. You are trying to controvert research that has been ongoing since the 1940s.

The other thing is that, the lines of reasoning and authors you are quoting are failing at using the chicken vs the egg approach and fail to take into account the most fundamental foundation of all matter, forces and things, which is the reference from which all phenomena spring forward, the reference or ground state. You can't have anything, nothing nada, zilch, without something else to compare it to. The QV is that reference. It is the most fundamental thing (Wolfram would say information is more fundamental). Be it sits at a zillion or zero, it is the reference.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/06/2014 02:37 am
The hateful reaction (of theoretical physicists) is really counter productive.

The problem is that, to paraphrase Nima Arkani-Hamed, it's really hard to come up with something that's not obviously wrong.

Regardless of whether it works or not, many of the explanations* that have been put forward, like Shawyer's original EM Drive paper, are just nonsense. And I'm not talking about whether they disagree with known physics, people are pretty relaxed about that, rather the authors don't even understand the physical theories that they're employing to base their claims on. That's what gets peoples' backs up.

* Woodward, having an internally consistent theory (though I wouldn't put any money on it), being an exception to this.

Except Woodward's theory relies on magic Machian inertia, "gravinertial flux" and "Flux Capacitors"....And ignores recent scientific observations showing anisotropy of the CMB, yet there is no anisotropic inertia. And his theory/thrusters have never been reproduced outside his own lab. Did I mention that Mach is so old school that he didn't believe in atoms? Did I mention that Machian inertia is so generalized, that it makes no actual predictions? Sometimes you just gotta let it go already, unless you wanna sell some books.

Quote
Often in modern science people try to defend the big, long, ongoing projects because their jobs depend on it. Not to say those projects do not create results but they often drain the funding for alternative approaches that may be much cheaper to look at while some times creating no results themselves.


really? funding conspiracy? that's where you're going with this?

Yes like spending billions and building careers searching out dark matter/dark energy/string theory, instead of checking their predispositions and math. The easy road.

Quote
Besides, theoretical physicists have their own skeletons in their closets, e.g. with all the popular black hole talk they hide that there can practically be no event horizon because it would take forever to form (infinite gravitational time dilatation) from our observation standpoint.

that's.. not how it works.

I mean; there are plenty of brickbats you could throw at theoretical physics with great justification (the unfalsifiability of string theory, for example), but you've picked a really bad one here.

Well Hawking has changed his mind on black holes so many times it has become clear that this is a work in progress. You function as if we have them figured out.

http://arxiv.org/abs/arXiv:1406.1525
http://arxiv.org/abs/arXiv:1409.1837
http://phys.org/news/2014-09-black-holes.html
It makes folks feel good to know they have all the answers, which leads to hubris. But in reality, we know very little.

I'm in blue.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/06/2014 03:04 am
It all boils down to what exactly is a better Casimir cavity.
Sheets of copper don't qualify. But is a start. We need a single sheet graphene cavity to understand whats going on.
I say this because bulk copper (or any bulk conductor) is a mess.
Surface effects et al are eliminated.

I'm in red above. The old parallel plate experiments were called Casimir cavities in the various literature I've encountered. I disagree with calling parallel plates cavities because they're not fully enclosed. Remembered the slashdot article.

http://science.slashdot.org/story/10/10/22/1538210/physicists-say-graphene-could-create-mass
http://www.technologyreview.com/view/421285/mass-can-be-created-inside-graphene-say-physicists/
http://arxiv.org/abs/1010.3437
http://nextbigfuture.com/2010/10/dynamical-mass-generation-via-space.html

Oh graphene, is there anything you can't do?
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/06/2014 03:10 am
I don't have any truck with the Casimir effect as I shall explain shortly..
Think thin films... ie graphene
ME is the only game in town for this thread...
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/06/2014 03:20 am
Imagine an infinite sheet of graphene.
Another sheet would find it impossible to lie on top. Casimir force would prevent it.
This is not observed.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/06/2014 03:29 am
Van der Waals forces... Can anyone explain them to me?
Title: Re: EM Drive Developments
Post by: 93143 on 12/06/2014 05:38 am
Nothing fancy:

http://en.wikipedia.org/wiki/Van_der_Waals_force
Title: Re: EM Drive Developments
Post by: Stormbringer on 12/06/2014 06:16 am
hutchinson apparently knows all about them ;)

Hutchinson; a canadian fringer made an experiment by throwing random surplus military electronic gear together in a cement tumbler truck and apparently mucked with everything from gravity to van  der wals forces.

too bad he did not record in written form his set up, time, conditions and procedure so that he could replicate it himself let alone let anyone else replicate it. The video record is impressive though. Which is why we should all go there and kick his sloppy adle brained no record keeping ass.
Title: Re: EM Drive Developments
Post by: cuddihy on 12/06/2014 12:03 pm

* Woodward, having an internally consistent theory (though I wouldn't put any money on it), being an exception to this.

Except Woodward's theory relies on magic Machian inertia, "gravinertial flux" and "Flux Capacitors"....And ignores recent scientific observations showing anisotropy of the CMB, yet there is no anisotropic inertia. And his theory/thrusters have never been reproduced outside his own lab. Did I mention that Mach is so old school that he didn't believe in atoms? Did I mention that Machian inertia is so generalized, that it makes no actual predictions? Sometimes you just gotta let it go already, unless you wanna sell some books.


If you want to fisk someone's post, rather than putting your comments in blue, I suggest you use the '[/quote' your comment '[quote' method as that way it's clear who's talking.

Can you explain in what way CMB anisotropy would imply inertial aniosotropy under Machian effects?

The anisotropies of the CMB shouldn't affect inertia unless they are on the size scale of the observable universe.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/06/2014 01:53 pm
Ok well first thing, VDW forces are the net effect of many forces. You are confusing VDW and Casimir forces. Vacuum forces are one component to VDW forces. After controls are put in place (conducting parallel plates), Casimir forces can be measured independently. You are trying to controvert research that has been ongoing since the 1940s.

The other thing is that, the lines of reasoning and authors you are quoting are failing at using the chicken vs the egg approach and fail to take into account the most fundamental foundation of all matter, forces and things, which is the reference from which all phenomena spring forward, the reference or ground state. You can't have anything, nothing nada, zilch, without something else to compare it to. The QV is that reference. It is the most fundamental thing (Wolfram would say information is more fundamental). Be it sits at a zillion or zero, it is the reference.

I shouldn't have to explain this on such an elementary level to such a smart guy, and the fact you're here being so obtuse indicates you don't really want to know the truth.  It'll tell you again anyway.

ZPF and QVF advocates are proposong that energy or propulsion can be drawn out of the vacuum, from virtual particles that according to Einstein, EEP and GR, cannot carry momentum.  They cannot mediate momentum exchange because they have no inertial mass, and they have no inertial mass because they have no gravitational mass.  If they had gravitational mass, they would collapse the universe, and EEP says gravitational mass and inertial mass must always be identical.  In fact for GR to be correct, they HAVE to be the same under all conditions because these are really the same thing.

When a ZPFer tells you that Casimir Effect is evidence for ZPF, what they're saying is, "see, here is an example of the virtual particles mediating momentum exchange" and they sell that tripe all the time.  The fact is though, almost no real physicists believe this, because they know there are other explanations for Casimir Effect than virtual particles carrying momentum.  I sent the paper that demonstrates this conclusively.  There is no debate about this.  Casimir in no way requires virtual particles mediate momentum exchange.  That is a completely superfluous argument and a distraction fallacy.  You are not thinking about the issue, because you have been distracted from it.

So when someone tells you, that Casimir is evidence for QVF, they have misled you, and when you tell someone else Casimir is evidence for QVF, you are misleading them out of ignorance.

BTW, I do not make these sorts of observations because I am an M-E advocate.  I am an M-E advocate because I make these kinds of observations.  ZPF and QVF are a scam.  There is nothing to them.
Title: Re: EM Drive Developments
Post by: Rodal on 12/06/2014 02:46 pm
http://vimeo.com/108650530
Title: Re: EM Drive Developments
Post by: RotoSequence on 12/06/2014 03:08 pm
I shouldn't have to explain this on such an elementary level to such a smart guy, and the fact you're here being so obtuse indicates you don't really want to know the truth.  It'll tell you again anyway.

ZPF and QVF advocates are proposong that energy or propulsion can be drawn out of the vacuum, from virtual particles that according to Einstein, EEP and GR, cannot carry momentum.  They cannot mediate momentum exchange because they have no inertial mass, and they have no inertial mass because they have no gravitational mass.  If they had gravitational mass, they would collapse the universe, and EEP says gravitational mass and inertial mass must always be identical.  In fact for GR to be correct, they HAVE to be the same under all conditions because these are really the same thing.

When a ZPFer tells you that Casimir Effect is evidence for ZPF, what they're saying is, "see, here is an example of the virtual particles mediating momentum exchange" and they sell that tripe all the time.  The fact is though, almost no real physicists believe this, because they know there are other explanations for Casimir Effect than virtual particles carrying momentum.  I sent the paper that demonstrates this conclusively.  There is no debate about this.  Casimir in no way requires virtual particles mediate momentum exchange.  That is a completely superfluous argument and a distraction fallacy.  You are not thinking about the issue, because you have been distracted from it.

So when someone tells you, that Casimir is evidence for QVF, they have misled you, and when you tell someone else Casimir is evidence for QVF, you are misleading them out of ignorance.

BTW, I do not make these sorts of observations because I am an M-E advocate.  I am an M-E advocate because I make these kinds of observations.  ZPF and QVF are a scam.  There is nothing to them.

I don't know enough to argue the merits of competing ideas for resolving the incompatibility of quantum mechanics and general relativity. However, jumping straight into the fray with a No True Scotsman isn't a very convincing approach.
Title: Re: EM Drive Developments
Post by: Rodal on 12/06/2014 03:13 pm
Some older work (middle 1990's) started at the University of Manchester proposing an electromagnetic drive.  The "thrust" in this case is derived to be proportional to the square of the quality factor Q:

http://jnaudin.free.fr/stvdmdoc/prplessp.htm

http://www.docstoc.com/docs/162279790/Propellant-less-Electromagnetic-Propulsion-by-Dimitriou-Stavros

http://jnaudin.free.fr/stvexp/html/stvrxp1a.htm

http://jnaudin.free.fr/stvdmdoc/stvcap.htm


http://www.electrogravity.com/STAVROS/Stavros1.pdf

http://jnaudin.free.fr/html/stvrfpend.htm

http://jnaudin.free.fr/html/stvrfpnd2.htm

http://jnaudin.free.fr/stvexp/html/stvcqtl.htm



Naudin claims to have reproduced this effect:


Quote from: Jean-Louis Naudin ( France )
The RF oscillator works very well and I have got some successfull motions of the device as mentioned in the Stavros' paper. The upward motion is not easily reproducible at each test run, but sometime a weak upward motion of the circular rim can be observed. More deep tests must be soon conducted...





Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/06/2014 03:31 pm
I don't know enough to argue the merits of competing ideas for resolving the incompatibility of quantum mechanics and general relativity. However, jumping straight into the fray with a No True Scotsman isn't a very convincing approach.

Are you saying I wasn't clear?  I don't see how I could be any clearer, and I am not "jumping straight into the fray".  We've had this conversation now for many weeks and Mullet doesn't seem to get the most obvious stuff no matter how many ways it is explained to him.  I would just let it go, but he's continuing to mislead others as well.

He's plainly wrong, and obviously wrong.  Is this not apparent to everyone here?  I'm not making a complex argument, and it's got nothing to do with the incompatibility between QM and GR.

Virtual particles cannot have mass, and therefore cannot exchange momentum.  If they did they would collapse the universe.  Since they don't, they are not useful for energy nor propulsion physics.  I was a ZPF adherent 10 years ago, before i understood the import of this very simple observation.  It is because of how ZPFers fail to answer this challenge that I have turned my back on this physics, as pseudo-science.  ZPF and QVF both fail to make any attempt to answer their obvious challenges with real science.  They are NOT science.  They are at best pseudoscience and at worst, pathological science.
Title: Re: EM Drive Developments
Post by: aceshigh on 12/06/2014 03:49 pm
Ron, I am not arguing in favor of ZPfers and all that. (I am really not)

However, you said that if those virtual particles had mass, they would collapse the universe.

And as we know, normal matter (baryonic?) constitutes only 16% of the total matter in the universe. If science understand that 84.5% of the matter in the universe is missing, but you are saying that if virtual particles had mass they would collapse the universe, does that means that if virtual particles had mass they would have a few orders of magnitude more mass than dark matter?


Quote
According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy.[2][3] Thus, dark matter is estimated to constitute 84.5% of the total matter in the universe, while dark energy plus dark matter constitute 95.1% of the total content of the universe.[4][5]
Title: Re: EM Drive Developments
Post by: aceshigh on 12/06/2014 03:53 pm
btw Ron, can you address Mulletrons post #3554, in special this part:

Quote
Except Woodward's theory relies on magic Machian inertia, "gravinertial flux" and "Flux Capacitors"....And ignores recent scientific observations showing anisotropy of the CMB, yet there is no anisotropic inertia. And his theory/thrusters have never been reproduced outside his own lab. Did I mention that Mach is so old school that he didn't believe in atoms? Did I mention that Machian inertia is so generalized, that it makes no actual predictions? Sometimes you just gotta let it go already, unless you wanna sell some books.

obviously his rant concerning Flux Capacitor just because of it´s name instead of what it does was a cheap shot. But what about the rest? Hasn´t Woodward theory thrusters been reproduced by others, including Paul March (who works with Sonny White)?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/06/2014 04:04 pm
Ron, I am not arguing in favor of ZPfers and all that. (I am really not)

However, you said that if those virtual particles had mass, they would collapse the universe.

And as we know, normal matter (baryonic?) constitutes only 16% of the total matter in the universe. If science understand that 84.5% of the matter in the universe is missing, but you are saying that if virtual particles had mass they would collapse the universe, does that means that if virtual particles had mass they would have a few orders of magnitude more mass than dark matter?


Quote
According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy.[2][3] Thus, dark matter is estimated to constitute 84.5% of the total matter in the universe, while dark energy plus dark matter constitute 95.1% of the total content of the universe.[4][5]

Yes.  No matter where you get your numbers for the virtual particles that should exist, if they were to gravitate, the universe could never have been born, or would have collapsed directly after birth.  This is an adjacent problem to the even more daunting issue that ZPF gives rise to the famed "Vacuum catastrophe" or the single worst prediction in all of modern science.  That is an amusing issue all on its own.

http://en.wikipedia.org/wiki/Vacuum_catastrophe
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/06/2014 04:24 pm
btw Ron, can you address Mulletrons post #3554, in special this part:

Quote
Except Woodward's theory relies on magic Machian inertia, "gravinertial flux" and "Flux Capacitors"....And ignores recent scientific observations showing anisotropy of the CMB, yet there is no anisotropic inertia. And his theory/thrusters have never been reproduced outside his own lab. Did I mention that Mach is so old school that he didn't believe in atoms? Did I mention that Machian inertia is so generalized, that it makes no actual predictions? Sometimes you just gotta let it go already, unless you wanna sell some books.

obviously his rant concerning Flux Capacitor just because of it´s name instead of what it does was a cheap shot. But what about the rest? Hasn´t Woodward theory thrusters been reproduced by others, including Paul March (who works with Sonny White)?

Yes.  The highest thrust magnitude ever recorded by any M-E researcher was recorded by Paul March in 2003, when testing a Mhz MLT--the thing Sonny ten years later renamed a "Q-Thruster" and claimed supported his model, in order to get his funding from DARPA.  The trouble is, as Sonny pointed out for years; that data was not valid since it did not make use of the proper scientific protocols.  There was no vacuum to isolate from things like thermal and ionic wind.  So there is no reason to suppose that was a useful test, and Sonny made this point many times before he decided to misrepresent Eagleworks and give folks the impression they had done these tests rather than that Paul had done them in the spare bedroom a decade before.  Sonny actually claims that his theory accurately predicts thrust from the Q-Thruster but the tests were done almost a decade before his model so obviously, he did not predict anything.  He merely matched his model to the data, same as he's done time and again with the warp interferometer, the Q-Thruster, Shawyers's E-M thruster, and Woodward's work including when Woodward had a broken balance.

Back in 2006 when Woodward was first characterizing the ARC-Lite, he posted that he could not explain the readings he had with an MLT on the balance, and simply owned they made no sense to him.  Sonny chimed in that his theory (which is not a theory but merely a model) predicts that thrust.  Then Woodward found Tom Mayhood had put the wrong Q Flex bearing in the balance and that it was broken under the mass of the balance itself.  Obviously Sonny was predicting garbage, except he was not predicting at all.  Real predictions always come BEFORE the data.  The next year Woodward was again saying he didn't understand the thrust from the MLT and again, Sonny said his theory predicts that thrust, and it turned out the thruster had a short running through the balance and was giving false readings.  Sonny does this kind of thing all the time.  This is why I always tell people do not trust what comes from that lab.  Everyone is all in a fuss over data taken with no vacuum.  This is just silly, IMHO.
Title: Re: EM Drive Developments
Post by: aero on 12/06/2014 04:26 pm
Ok well first thing, VDW forces are the net effect of many forces. You are confusing VDW and Casimir forces. Vacuum forces are one component to VDW forces. After controls are put in place (conducting parallel plates), Casimir forces can be measured independently. You are trying to controvert research that has been ongoing since the 1940s.

The other thing is that, the lines of reasoning and authors you are quoting are failing at using the chicken vs the egg approach and fail to take into account the most fundamental foundation of all matter, forces and things, which is the reference from which all phenomena spring forward, the reference or ground state. You can't have anything, nothing nada, zilch, without something else to compare it to. The QV is that reference. It is the most fundamental thing (Wolfram would say information is more fundamental). Be it sits at a zillion or zero, it is the reference.

I shouldn't have to explain this on such an elementary level to such a smart guy, and the fact you're here being so obtuse indicates you don't really want to know the truth.  It'll tell you again anyway.

ZPF and QVF advocates are proposong that energy or propulsion can be drawn out of the vacuum, from virtual particles that according to Einstein, EEP and GR, cannot carry momentum.  They cannot mediate momentum exchange because they have no inertial mass, and they have no inertial mass because they have no gravitational mass.  If they had gravitational mass, they would collapse the universe, and EEP says gravitational mass and inertial mass must always be identical.  In fact for GR to be correct, they HAVE to be the same under all conditions because these are really the same thing.

When a ZPFer tells you that Casimir Effect is evidence for ZPF, what they're saying is, "see, here is an example of the virtual particles mediating momentum exchange" and they sell that tripe all the time.  The fact is though, almost no real physicists believe this, because they know there are other explanations for Casimir Effect than virtual particles carrying momentum.  I sent the paper that demonstrates this conclusively.  There is no debate about this.  Casimir in no way requires virtual particles mediate momentum exchange.  That is a completely superfluous argument and a distraction fallacy.  You are not thinking about the issue, because you have been distracted from it.

So when someone tells you, that Casimir is evidence for QVF, they have misled you, and when you tell someone else Casimir is evidence for QVF, you are misleading them out of ignorance.

BTW, I do not make these sorts of observations because I am an M-E advocate.  I am an M-E advocate because I make these kinds of observations.  ZPF and QVF are a scam.  There is nothing to them.
I'm not sure what you are saying Paul, but taken at face value your remarks seem to disagree with well established theory.  For example, from
http://www.halexandria.org/dward155.htm (http://www.halexandria.org/dward155.htm)

Quote
   
Zero-Point Field

The Zero-Point Field (ZPF) is said to exist in a vacuum -- what is commonly thought of as empty space -- at a temperature of absolute zero (where all thermal radiation is absent; a condition obtained when reaching a temperature of absolute zero on the Kelvin scale).  The background energy of the vacuum serves as the reference, or zero point, for all processes.  Theoretical considerations indicate the ZPF should be a background sea of electromagnetic radiation that is both uniform and isotropic (the same in all directions). 

The uniform and isotropic nature of the ZPF is important, and explains why it is not readily observed.  Fundamentally, the lack of asymmetry of the ZPF prevents its easy identification, just as a fish being absolutely still in a sea of constant temperature and pressure water is unable to detect the water itself. 

In some cases, motion through a medium can give rise to asymmetries, thus in turn allowing for the detection of the medium.  However, in the case of the ZPF, motion through the “medium” (i.e. the field) at a constant velocity has not been shown to make the field detectable.  This is because the field has the property of being "Lorentz invariant." (Lorentz invariance is a critical difference between the modern ZPF and nineteenth-century concepts of an ether.)  In fact, the ZPF becomes detectable only when a body is accelerated through space. 

There is, of course, a fundamental difference between “detectable” and “useable”.  It is likely necessary to go beyond a simple, constant acceleration through space (in order to detect the ZPF), and instead, transition into a variable acceleration in order to tap into the energy of the ZPF.  In this case, we can assume with a reasonable confidence that the greater the change in acceleration, the greater the energy derived from the ZPF. 

Physicists Paul C. W. Davies and William G. Unruh, showed in the mid 1970s that a moving observer distorts the ZPF spectrum by accelerating through the field.  Furthermore, this distortion increases with increasing acceleration. Extending these findings would suggest highly variable accelerations could provide increased distortions, and that these distortions could be used as an energy source.  While these distortions are small, they add up rapidly.  At the same time, detailed analysis shows that the distortions are fundamentally the origin of inertia.

As for the need for virtual particles to cause force, virtual particles are not needed. The Casimir force can be calculated strictly using Maxwell's equations and using the ZPF field model. I have seen the derivation in analytical form, unfortunately I did not save the link. But it can also be calculated numerically in the time domain. Here is the link to that program and calculation.

http://ab-initio.mit.edu/wiki/index.php/Casimir_calculations_in_Meep (http://ab-initio.mit.edu/wiki/index.php/Casimir_calculations_in_Meep)

Note that the Meep software is freely available for download and the link gives complete instructions for calculating the Casimir force. Anyone who doubts the result can download the source software, evaluate it, compile and run it to see the results personally.

So I'm not sure what you are saying. Casimir force exists, it has been measured many times. ZPF exists, its model correctly predicts results of multiple laboratory experiments measuring said Casimir forces. A somewhat newer result, Casimir forces can be attractive or repulsive, see the above reference.

But I agree, at no point does the Casimir effect invoke virtual particles.

Title: Re: EM Drive Developments
Post by: aceshigh on 12/06/2014 04:30 pm
btw Ron, can you address Mulletrons post #3554, in special this part:

Quote
Except Woodward's theory relies on magic Machian inertia, "gravinertial flux" and "Flux Capacitors"....And ignores recent scientific observations showing anisotropy of the CMB, yet there is no anisotropic inertia. And his theory/thrusters have never been reproduced outside his own lab. Did I mention that Mach is so old school that he didn't believe in atoms? Did I mention that Machian inertia is so generalized, that it makes no actual predictions? Sometimes you just gotta let it go already, unless you wanna sell some books.

obviously his rant concerning Flux Capacitor just because of it´s name instead of what it does was a cheap shot. But what about the rest? Hasn´t Woodward theory thrusters been reproduced by others, including Paul March (who works with Sonny White)?

Yes.  The highest thrust magnitude ever recorded by any M-E researcher was recorded by Paul March in 2003, when testing a Mhz MLT--the thing Sonny ten years later renamed a "Q-Thruster" and claimed supported his model, in order to get his funding from DARPA.  The trouble is, as Sonny pointed out for years; that data was not valid since it did not make use of the proper scientific protocols.  There was no vacuum to isolate from things like thermal and ionic wind.  So there is no reason to suppose that was a useful test, and Sonny made this point many times before he decided to misrepresent Eagleworks and give folks the impression they had done these tests rather than that Paul had done them in the spare bedroom a decade before.  Sonny actually claims that his theory accurately predicts thrust from the Q-Thruster but the tests were done almost a decade before his model so obviously, he did not predict anything.  He merely matched his model to the data, same as he's done time and again with the warp interferometer, the Q-Thruster, Shawyers's E-M thruster, and Woodward's work including when Woodward had a broken balance.

Back in 2006 when Woodward was first characterizing the ARC-Lite, he posted that he could not explain the readings he had with an MLT on the balance, and simply owned they made no sense to him.  Sonny chimed in that his theory (which is not a theory but merely a model) predicts that thrust.  Then Woodward found Tom Mayhood had put the wrong Q Flex bearing in the balance and that it was broken under the mass of the balance itself.  Obviously Sonny was predicting garbage, except he was not predicting at all.  Real predictions always come BEFORE the data.  The next year Woodward was again saying he didn't understand the thrust from the MLT and again, Sonny said his theory predicts that thrust, and it turned out the thruster had a short running through the balance and was giving false readings.  Sonny does this kind of thing all the time.  This is why I always tell people do not trust what comes from that lab.  Everyone is all in a fuss over data taken with no vacuum.  This is just silly, IMHO.

thanks Ron, but you ended up only talking about the part about it being tested outside Woodward's lab.

can you please address these parts by Mulletron:

Quote
relies on magic Machian inertia, "gravinertial flux" and "Flux Capacitors"....And ignores recent scientific observations showing anisotropy of the CMB, yet there is no anisotropic inertia.

Quote
Did I mention that Mach is so old school that he didn't believe in atoms? Did I mention that Machian inertia is so generalized, that it makes no actual predictions?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/06/2014 04:43 pm
So I'm not sure what you are saying. Casimir force exists, it has been measured many times. ZPF exists, its model correctly predicts results of multiple laboratory experiments measuring said Casimir forces. A somewhat newer result, Casimir forces can be attractive or repulsive, see the above reference.

But I agree, at no point does the Casimir effect invoke virtual particles.
That is really the issue.  I don't think anyone doubts Davies and Unruh.  It is the later work by Haishe, Puthoff and Ruada that argues inertia comes from virtual particles, that makes no sense, and especially that these particles can be used for propulsion and energy as QVF argues--again makes no sense.

Casimir has indeed been observed, but with no virtual particles at all, it is easy to explain.  So Casimir in no way provides evidence for virtual particles mediating momentum exchange.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/06/2014 04:58 pm
can you please address these parts by Mulletron:

Quote
relies on magic Machian inertia, "gravinertial flux" and "Flux Capacitors"....And ignores recent scientific observations showing anisotropy of the CMB, yet there is no anisotropic inertia.

Quote
Did I mention that Mach is so old school that he didn't believe in atoms? Did I mention that Machian inertia is so generalized, that it makes no actual predictions?

Well, I am not a cosmologist.  I will note that Woodward's mother is, and he is a fair cosmologist himself, so far better to get an answer from his book than from me.  However, I think what Mullet wants to talk about is theta, not anisotropy.  The question is whether the universe is essentially flat on global scale and the answer is yes, it is.  This theta is the issue that makes or breaks Mach's and Woodward's models, not anisotropy.  And in fact, this has been the subject of ongoing argument on Woodward's list for 18 months now, with Jack Sarfatti.  The issue is explained in the book, and the argument made direct from the WMAP data, that Mach's Principle must be true because we observe the flatness of the universe.  This is a very complex argument, but essentially what it boils down to is, whether the gravitational field of the universe exists only where we see gradient, or even when the field is flat.  The answer is, there is field everywhere that is a where, regardless of the gradient of the field at that point.  For a better explanation see Woodward's book.

As to Mach's Principle making no predictions, well obviously that's not true.  It predicts thrust from Jim's thrusters.  All his papers are full of equations that can be used to make predictions.  That's just silly rhetoric.  Mach's Principle was set aside, not because Einstein and Mach fell out, nor because it was considered wrong, but because GR was so successful Mach's explanation seemed an unnecessary aside.  And in fact, it is unnecessary unless you want control over inertia.  We have done quite nicely without it for a century, but then again, we have done without control over inertia as well.
Title: Re: EM Drive Developments
Post by: aceshigh on 12/06/2014 05:09 pm
I will note that Woodward's mother is

IS??? Woodward seems to be some 80 years old already by the photos. How old is his mother? 105?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/06/2014 05:42 pm
Woodward is in his early 70's.  I'm not sure if his mother is still alive.  He doesn't speak much of family and keeps that part of his life private.  I believe he says in his book however, that his father was a patent lawyer and his mother an astronomer.
Title: Re: EM Drive Developments
Post by: Rodal on 12/06/2014 06:32 pm
can you please address these parts by Mulletron:

Quote
relies on magic Machian inertia, "gravinertial flux" and "Flux Capacitors"....And ignores recent scientific observations showing anisotropy of the CMB, yet there is no anisotropic inertia.

Quote
Did I mention that Mach is so old school that he didn't believe in atoms? Did I mention that Machian inertia is so generalized, that it makes no actual predictions?

Well, I am not a cosmologist.  I will note that Woodward's mother is, and he is a fair cosmologist himself, so far better to get an answer from his book than from me.  However, I think what Mullet wants to talk about is theta, not anisotropy.  The question is whether the universe is essentially flat on global scale and the answer is yes, it is. ....

No, what Mullet asked about was concerning ANISOTROPY of the CMB, and not anything regarding flatness of the spatial dimensions of the universe.  Anisotropy has nothing necessarily to do with whether space is  flat or curved.  Anisotropy has to do with different properties in different directions.

This is an excellent observation by Mullet.

Although I have no affinity with Woodward's Machian approach, I would answer it this way.

The anisotropy of the cosmic microwave background (CMB) consists of very small temperature fluctuations in the blackbody radiation (left over from the Big Bang).  The average temperature of this radiation has been measured by the instrument on the COBE satellite as 2.725 K.  The temperature variations have been measured as (at most) plus or minus 0.00335 K variation with one hot pole and one cold pole.  Other, newer, estimates are of  0.0005 K.

Let's take the range as +/- 0.00335 K,  this is only (0.00335 K) / (2.725 K) = +/- 0.12 %  (about one part in 1,000 )

Integrating this over the whole space, this variation would have a very small effect on inertia, because the regions with higher and lower temperature of the CMB are small and most of the CMB is much closer to the average temperature.  I would question whether experiments on inertia have been conducted that would be able to discriminate within such small diffferences regarding orientation.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/06/2014 07:23 pm
There is at least one discussion of this in Barbour and Pfister, in the piece by Hans Reissner on "Relativity of Accelerations in Mechanics", on page 144, but I don't think this is the issue you think it is.  Inhomogeneity does not beget anisotropy.  Keep in mind that according to Mach, it is not the closest masses that most affect local inertia it is those that are farthest away.  Still, there was this debate in the early teens with Schrodinger and Reissner and you'll find it referenced in Barbour & Pfister.  Schrodinger's response is immediately following.

B&F is truly the indispensable source for understanding Mach's Principle in its historic context.  However, also see:

"Mach's relativity of inertia does not necessarily imply an anisotropy of inertial masses in an anisotropic universe and the Mach-Einstein doctrine is compatible with the isotropy of mass in each cosmos."

http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1992AN....313...65T&db_key=AST&page_ind=0&data_type=GIF&type=SCREEN_VIEW&classic=YES
Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/06/2014 07:28 pm
Just a quick nod to Mullet.

The doppler frequencies that give the AFR do indeed add up to the drive frequency. 

Thanks !
Title: Re: EM Drive Developments
Post by: Mulletron on 12/06/2014 08:06 pm

* Woodward, having an internally consistent theory (though I wouldn't put any money on it), being an exception to this.

Except Woodward's theory relies on magic Machian inertia, "gravinertial flux" and "Flux Capacitors"....And ignores recent scientific observations showing anisotropy of the CMB, yet there is no anisotropic inertia. And his theory/thrusters have never been reproduced outside his own lab. Did I mention that Mach is so old school that he didn't believe in atoms? Did I mention that Machian inertia is so generalized, that it makes no actual predictions? Sometimes you just gotta let it go already, unless you wanna sell some books.


If you want to fisk someone's post, rather than putting your comments in blue, I suggest you use the '[/quote' your comment '[quote' method as that way it's clear who's talking.

Can you explain in what way CMB anisotropy would imply inertial aniosotropy under Machian effects?

The anisotropies of the CMB shouldn't affect inertia unless they are on the size scale of the observable universe.

Indeed the CMB is the limit of the observable universe. It is a barrier you can't see past. It has structural anisotropy and a dipole anisotropy. Here's some more info:
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.112.582
http://www.haverford.edu/physics/dcross/research/papers/oral.pdf
http://en.wikipedia.org/wiki/Hughes%E2%80%93Drever_experiment
http://en.wikipedia.org/wiki/Cosmic_microwave_background#CMBR_dipole_anisotropy
http://link.springer.com/article/10.1007%2FBF02859800
http://arxiv.org/pdf/1307.2637.pdf
Title: Re: EM Drive Developments
Post by: Rodal on 12/06/2014 08:07 pm
There is at least one discussion of this in Barbour and Pfister, in the piece by Hans Reissner on "Relativity of Accelerations in Mechanics", on page 144, but I don't think this is the issue you think it is.  Inhomogeneity does not beget anisotropy.  Keep in mind that according to Mach, it is not the closest masses that most affect local inertia it is those that are farthest away.  Still, there was this debate in the early teens with Schrodinger and Reissner and you'll find it referenced in Barbour & Pfister.  Schrodinger's response is immediately following.

B&F is truly the indispensable source for understanding Mach's Principle in its historic context.  However, also see:

"Mach's relativity of inertia does not necessarily imply an anisotropy of inertial masses in an anisotropic universe and the Mach-Einstein doctrine is compatible with the isotropy of mass in each cosmos."

http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1992AN....313...65T&db_key=AST&page_ind=0&data_type=GIF&type=SCREEN_VIEW&classic=YES

Concerning your statement <<Inhomogeneity does not beget anisotropy>> , nobody said that inhomogeneity begets anisotropy (it is well known that most isotropic bodies are isotropic due to the small scale and randomness of their anisotropy).

Mullet's observation was concerning the established anisotropy of the CMB.  What I wrote was: <<The temperature variations have been measured as (at most) plus or minus 0.00335 K variation with one hot pole and one cold pole. >> that refers to the dipole established by the difference in temperature between the hot pole and the cold pole of the CMB: this clearly established a (very small, as I remarked) anisotropy.  We are not discussing here some hypothetical effect [as in Cocconi and Salpatz (1958) discussed below], we are discussing Mullet's observation concerning the anisotropy of the CMB due to this dipole.

Concerning the 1992 paper by Treder you quote, it does not address at all the established anisotropy of the CMB, it discusses instead a) the problem of the masses in the universe being at different distances (near and distant mass attractors) from a given object whose inertia we are interested in, and b) the hypothetical ansatz of Cocconi and Salpatz (1958) (a different hypothetical inertial field ansatz in addition to the Newtonian field) . 

Therefore your quotation of Treder is not applicable to the CMB anisotropy issue referred to by Mullet's excellent observation.

The issue referred to by Mullet should rather be addressed in terms of an integration (over all directions)  which will show it to be of a very small nature (as remarked previously) perhaps beyond any experimental inertial measurement conducted up to now (?) regarding different orientations.  It may be small, but it is not non-existent.  The anisotropy of the CMB is something that cannot be denied. It may be very small (some sources say one part in 100,000 according to how you measure it) but it took four years to map the  anisotropy of cosmic background radiation as it was the only instrument not dependent on the dewar’s supply of helium to keep it cooled, and nobody denies its existence.

Thus, Mullet presents a very interesting experiment (if it could be conducted to the required precision) from which, perhaps one could establish the validity (or non-validity) of Machian inertia.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/06/2014 08:08 pm
http://vimeo.com/108650530

Thank you for posting this. We all dream to see this with our own eyes, if only...
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/06/2014 08:21 pm
Therefore your quotation of Treder is not applicable to the CMB anisotropy issue referred to by Mullet's excellent observation.

I guess then, I must confess I don't understand the point.  The gravitational field of the universe, that gives matter its mass and is the cause of inertia, is in no way connected to the thermal distribution of the CMB.  The CMB loosely corresponds to the mass distribution of the universe, so I presumed this is what you were both speaking of.  The present thermal distribution is however, beside the point so far as I can see.

I thought you were both referring to the inhomogeneities in the gravitational field one would suppose is there when one notes the inhomogeneities in the CMB.  Now you have said more than once you're more specifically talking about the thermal background, and I confess I don't see how this pertains apart from how it illustrates the mass background.

I'll be away Sunday so please don't take it as a slight that you spank me good here and I disappear.  I am looking forward to learning what you two are saying.  Bon weekend.
Title: Re: EM Drive Developments
Post by: Rodal on 12/06/2014 08:39 pm
Therefore your quotation of Treder is not applicable to the CMB anisotropy issue referred to by Mullet's excellent observation.

I guess then, I must confess I don't understand the point.  The gravitational field of the universe, that gives matter its mass and is the cause of inertia, is in no way connected to the thermal distribution of the CMB.  The CMB loosely corresponds to the mass distribution of the universe, so I presumed this is what you were both speaking of.  The present thermal distribution is however, beside the point so far as I can see.

I thought you were both referring to the inhomogeneities in the gravitational field one would suppose is there when one notes the inhomogeneities in the CMB.  Now you have said more than once you're more specifically talking about the thermal background, and I confess I don't see how this pertains apart from how it illustrates the mass background.

I'll be away Sunday so please don't take it as a slight that you spank me good here and I disappear.  I am looking forward to learning what you two are saying.  Bon weekend.

1) Essentially, the Treder quotation refers to outdated astrophysical data from 1964 and 1961, (Hughes and Drever: their actual experiment probing only the quadrupolar anisotropy) to quantify his alpha and beta in his equations that lead him to disregard anisotropy.  Up to date astrophysical data is needed, not these astrophysical data that is more than 50 years old.

2) Also a newer reference is needed regarding an up to date ansatz for the anisotropy of the most distant bodies responsible for Machian inertia. The ansatz dealt with by Treder, including the hypothetical (multiple) ansatz proposed by Cocconi is not longer relevant.

3) As you know, Machian principle determines the inertia of bodies, in a way that the heavy and distant bodies of our universe contribute the most to the inertial forces, thus anisotropy of the most distant bodies matters most. The most distant bodies that we are able to measure are also the ones that are most distant in time (closer in time to the Big Bang) since light took longer to contact us.


Title: Re: EM Drive Developments
Post by: Rodal on 12/06/2014 09:21 pm
Therefore your quotation of Treder is not applicable to the CMB anisotropy issue referred to by Mullet's excellent observation.

I guess then, I must confess I don't understand the point.  The gravitational field of the universe, that gives matter its mass and is the cause of inertia, is in no way connected to the thermal distribution of the CMB.  The CMB loosely corresponds to the mass distribution of the universe, so I presumed this is what you were both speaking of.  The present thermal distribution is however, beside the point so far as I can see.

I thought you were both referring to the inhomogeneities in the gravitational field one would suppose is there when one notes the inhomogeneities in the CMB.  Now you have said more than once you're more specifically talking about the thermal background, and I confess I don't see how this pertains apart from how it illustrates the mass background.

I'll be away Sunday so please don't take it as a slight that you spank me good here and I disappear.  I am looking forward to learning what you two are saying.  Bon weekend.

1) Essentially, the Treder quotation refers to outdated astrophysical data from 1964 and 1961, (Hughes and Drever: their actual experiment probing only the quadrupolar anisotropy) to quantify his alpha and beta in his equations that lead him to disregard anisotropy.  Up to date astrophysical data is needed, not these astrophysical data that is more than 50 years old.

2) Also a newer reference is needed regarding an up to date ansatz for the anisotropy of the most distant bodies responsible for Machian inertia. The ansatz dealt with by Treder, including the hypothetical (multiple) ansatz proposed by Cocconi is not longer relevant.

3) As you know, Machian principle determines the inertia of bodies, in a way that the heavy and distant bodies of our universe contribute the most to the inertial forces, thus anisotropy of the most distant bodies matters most.  The most distant bodies that we are able to measure are also the ones that are most distant in time (closer in time to the Big Bang) since light took longer to contact us. 


4) This 2004 paper attempts to address Mullet's observation concerning the CMB anisotropy and goes further than Treder :

Anisotropy of Inertia from the CMB Anisotropy
Daniel J. Cross


http://www.haverford.edu/physics/dcross/research/papers/oral.pdf

but the conclusion readily admits that it is incomplete

Quote from: Anisotropy of Inertia from the CMB Anisotropy
It is regrettable that this project remains uncompleted at this point. The framework has
been laid above, but there are several steps left before completion. Its has been shown that
an inertial mass that depends arbitrarily on direction is a priori possible, the dependence
presumably arising from an interaction with anisotropic matter at great distances, in the
spirit of Mach's Principle. Even though the angular dependence is quite general, the pos-
sible couplings to matter in experiments of the Hughes-Drever type is severely restricted,

their actual experiment probing only the quadrupolar anisotropy. Based on their experi-
ment a limit was set on the quadrupolar term in the inertial mass anisotropy. It remains to
compare expansion coe±cients between the inertial mass and matter anisotropy at great
distance through the WMAP data of the CMB.
From this comparison, limits can be set on
higher coe±cients to see whether these multipoles are accessible to observation. Finally,
it is desirable to propose a speci¯c coupling scheme between local inertia and distant mat-
ter, possibly through 1=R type interaction. In this manner it may be possible to predict
absolute values of the local multipole coe±cients, and therefore be more certain that the
Hughes-Drever tests have actually ruled out such anisotropy or are yet too insensitive.

I expect that Machian inertia researchers should have already addressed this issue more in depth and up-to-date than what I have seen, as it is important to completely address anisotropy of inertia vis-a-vis experiments to validate their theory.  Therefore I hope that the backers of Machian inertia can uncover better and up-to-date references to properly address the excellent point brought up by Mulletron.
Title: Re: EM Drive Developments
Post by: frobnicat on 12/07/2014 12:47 am
I'm loosing feet with what is going on here with ME vs EM. Regarding the former, I understand Ron states it is not incompatible with GR, so not with SR, so not with Lorentz invariance. But it can predict the result of a situation that GR cannot predict, namely situation of a ME thruster thrusting. This "hole" in GR was never noticed because such prediction for such situation never needed, kind of, so possible Machian "extension" (?) to GR forgotten. How could it be that a mundane device like a ME thruster could leave classic frameworks GR + QFT voiceless ?

This is not a problem of interpretation but of prediction, the two classical frameworks GR+QFT (which show no practical incompatibilities when dealing with meso-scale, low energies, low background curvatures) surely would tell the magnitude of the thrust, and that the net thrust is equal or bellow spent_power/c, or more simply 0 if nothing is expelled (no matter, no radiation). I can't see how this very specific device (ME thruster) could leave the equations of GR+QFT befuddled to the point of being unable to be solved or converge clearly on some definite answer. And this answer would be in contradiction with claimed thrust/power that ME theory seems to allow. So it could be that ME theory is more general than GR in the same sense that GR is more general than Newtonian dynamics. GR would have a limited range of validity (all that has been uncontroversially observed and measured accurately so far within mesoscale) and ME theory a bigger one (all that has been uncontroversially observed and measured accurately so far within mesoscale + ME thruster thrusting at thrust/power>1/c). Note that a ME thruster is clearly mesoscale. Not speaking here of wide or dense objects, yet to be accurately observed and characterised in their constitution (like galaxies, gravitationally collapsed bodies...). Anyhow, wouldn't say that GR is "compatible" with Newtonian dynamics. B is compatible with A if B has the same answers as A whenever A answers at all. Or would Machian effect proponents say that GR is only an approximation, valid only in a certain "range", and that can be shown as a limit in this range of a more general Machian physics (B says the same thing as A for a limited configuration space, and a different thing outside) ?

Be assured this is my writing which is confused, not your reading.

Back to the subject, assuming a Machian physics is compatible with SR, that would make the dipole moment of CMB irrelevant, this is (very most likely...) due to our contingent velocity in the bath. Put a rocket at velocity relative to sun (around 370km/s, easy)  and the dipole vanishes. And the same experiments onboard that rocket give exact same results as those on earth labs (interactions with local bath excluded). That's what SR tells (Newtonian also), so this is what a SR compatible Machian physics would tell also. Such Machian physics couldn't be falsified by the absence of inertia anisotropy in spite of dipole moment.

As for the higher order anisotropies... this looks like a nice playground, full of hills and hollows. What a GR compatible Machian physics would have to say different from what would say GR : local inertias don't care ? Anyway, it claims to predict an effect that is astounding for most people working with GR under the form of a ME thruster thrusting. Can't the theory devise one other type of experiment that is at least as astounding and that could lend itself to more convincing reproducible results ? Call it an experiment in fundamental science (à la Michelson and Morley). Better credibility to the theory if it can expose itself to experimental falsifiability on other grounds that notoriously capricious propellentless drives. Are there such other falsifiable grounds ?
Title: Re: EM Drive Developments
Post by: Rodal on 12/07/2014 01:47 am
I'm loosing feet with what is going on here with ME vs EM. Regarding the former, I understand Ron states it is not incompatible with GR, so not with SR, so not with Lorentz invariance. But it can predict the result of a situation that GR cannot predict, namely situation of a ME thruster thrusting. This "hole" in GR was never noticed because such prediction for such situation never needed, kind of, so possible Machian "extension" (?) to GR forgotten. How could it be that a mundane device like a ME thruster could leave classic frameworks GR + QFT voiceless ?

This is not a problem of interpretation but of prediction, the two classical frameworks GR+QFT (which show no practical incompatibilities when dealing with meso-scale, low energies, low background curvatures) surely would tell the magnitude of the thrust, and that the net thrust is equal or bellow spent_power/c, or more simply 0 if nothing is expelled (no matter, no radiation). I can't see how this very specific device (ME thruster) could leave the equations of GR+QFT befuddled to the point of being unable to be solved or converge clearly on some definite answer. And this answer would be in contradiction with claimed thrust/power that ME theory seems to allow. So it could be that ME theory is more general than GR in the same sense that GR is more general than Newtonian dynamics. GR would have a limited range of validity (all that has been uncontroversially observed and measured accurately so far within mesoscale) and ME theory a bigger one (all that has been uncontroversially observed and measured accurately so far within mesoscale + ME thruster thrusting at thrust/power>1/c). Note that a ME thruster is clearly mesoscale. Not speaking here of wide or dense objects, yet to be accurately observed and characterised in their constitution (like galaxies, gravitationally collapsed bodies...). Anyhow, wouldn't say that GR is "compatible" with Newtonian dynamics. B is compatible with A if B has the same answers as A whenever A answers at all. Or would Machian effect proponents say that GR is only an approximation, valid only in a certain "range", and that can be shown as a limit in this range of a more general Machian physics (B says the same thing as A for a limited configuration space, and a different thing outside) ?

Be assured this is my writing which is confused, not your reading.

Back to the subject, assuming a Machian physics is compatible with SR, that would make the dipole moment of CMB irrelevant, this is (very most likely...) due to our contingent velocity in the bath. Put a rocket at velocity relative to sun (around 370km/s, easy)  and the dipole vanishes. And the same experiments onboard that rocket give exact same results as those on earth labs (interactions with local bath excluded). That's what SR tells (Newtonian also), so this is what a SR compatible Machian physics would tell also. Such Machian physics couldn't be falsified by the absence of inertia anisotropy in spite of dipole moment.

As for the higher order anisotropies... this looks like a nice playground, full of hills and hollows. What a GR compatible Machian physics would have to say different from what would say GR : local inertias don't care ? Anyway, it claims to predict an effect that is astounding for most people working with GR under the form of a ME thruster thrusting. Can't the theory devise one other type of experiment that is at least as astounding and that could lend itself to more convincing reproducible results ? Call it an experiment in fundamental science (à la Michelson and Morley). Better credibility to the theory if it can expose itself to experimental falsifiability on other grounds that notoriously capricious propellentless drives. Are there such other falsifiable grounds ?

Great points, including the fact about the dipole moment being irrelevant [initially I had to think about that one, thank you] and the higher order anisotropies being the relevant ones -for discrimination-. 

Quote from: http://www.haverford.edu/physics/dcross/research/papers/oral.pdf
the matter distribution around us exhibits clumping which is understood as
Gaussian quantum fluctuations that were stretched into real density perturbations by
the expansion of the universe. Such perturbations in the matter distribution lead to
gravitational perturbations that alter the temperature of photons through redshift and
time dilation. This is known as the Sachs-Wolfe effect and dominates the anisotropy at
large scales. The next contribution to the anisotropy comes from Doppler shifting which does not contribute appreciably until l >30


Quote from:  http://cosmo.fis.fc.ul.pt/users/crawford/papers/swf_cqg.pdf

In this work it is shown that there are some spatially homogeneous
but anisotropic models
(Kantowski-Sachs and Bianchi type-III), with a positive
cosmological constant, for which the inhomogeneities in the distribution of matter on
the surface of the last scattering produce anisotropies (in large angular scales # »> 10±)
that do not di®er from the ones produced in Friedmann-Lemaitre-Robertson-Walker
(FLRW) models, if the density parameters are finely tuned.


Title: Re: EM Drive Developments
Post by: Mulletron on 12/07/2014 08:47 am

Plenty of atmo here in NYC. Thought about how it pushes on me, like Mull's QV. If I wanna go thru the atmo w/o expelling propellant, I gotta use a propeller. Mull, yer gonna have to come up with a propeller.  And then we can all start calling it the aether.

What I'm describing is called a differential sail, more specifically an induction sail, which is/was a hypothetical concept theorized by Marc G. Millis. It just hasn't been realized, until......now? Time will tell.

http://www.nasa.gov/centers/glenn/technology/warp/ideachev.html
http://en.wikipedia.org/wiki/Breakthrough_Propulsion_Physics_Program#Differential_sail
http://www.daviddarling.info/encyclopedia/D/differential_sail.html

Title: Re: EM Drive Developments
Post by: Rodal on 12/07/2014 03:46 pm
...
 Mull's QV. If I wanna go thru the atmo w/o expelling propellant, I gotta use a propeller. Mull, yer gonna have to come up with a propeller.  And then we can all start calling it the aether.
No, that's not Mull's model, that's Sonny White's model:

*Sonny White: models the QV (per his own words) as water around a submarine.  White thinks of the EM Drive as a propeller that pushes on the quantum vacuum electron-positron pairs to propel it forward and in turn it leaves a wake behind the submarine.  Sonny White said at the Ames conference in August 2014 that his next step is to try to measure the wake left behind by the EM Drive on the quantum vacuum by using another EM Drive behind the propelling EM Drive to measure the wake.

(http://www.xflowusa.com/s/cc_images/cache_940496808.png?t=1413688632)



*Mulletron, contrary to Sonny White thinks of the quantum vacuum as a medium with intrinsic momentum
Thus, he thinks of the quantum vacuum not as an inert aether that just sits there as a solid with extremely high modulus of elasticity (as Maxwell thought of the aether).  Mull thinks of the quantum vacuum as a medium with momentum.
Thus no propeller is needed. What is needed (as per Feigel using the magnetoelectric effect, or as per helical anisotropy of a polymer dielectric, etc.) is a means to act as a sail against the wind, to let the quantum vacuum push the spacecraft: to transfer the momentum of the quantum vacuum into the spacecraft.

Notice that with the wind at the back of the sail, the downwind "leeward" region is the region with leading edge separation and where turbulent reattachment occurs, sometimes followed by trailing edge separation. 

Thus, Sonny White's idea presents a possible way to falsify one of these models: is there a wake behind the EM Drive (White) or a separated turbulent region upstream of the EM drive ?

(http://dit-archives.epfl.ch/SCR98/scr10-page24-8.gif)



Capisce ?

(http://www.thedailycrate.com/wp-content/uploads/2014/09/grumbling_spn.gif)
Title: Re: EM Drive Developments
Post by: RotoSequence on 12/07/2014 07:32 pm
I really like the idea of testing for turbulence. I smell a potential snag, though. How do we know the turbulence, if it exists, isn't extremely short-lived and difficult, if not impossible, to test for?
Title: Re: EM Drive Developments
Post by: SteveKelsey on 12/08/2014 07:21 am
Stupid question from the peanut gallery,...again. If we are looking at QVF are we not looking at Planck scale events? I thought that the virtual particle pairs were created and destroyed at the Planck scale. If so, yes the wake might be very short lived and very small. Just a question while I buy John some more peanuts in the intermission.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/08/2014 09:08 am
I don't know how you could directly see what was happening at such a small scale. Most sources say the QV is Lorentz-invariant. Once source argues it is covariant (below). We can't treat it as if it is a fluid or anything like that. Anybody know if Goldstone's theorem applies here?

http://link.springer.com/chapter/10.1007%2F3-540-53941-7_9

http://www.ovaltech.ca/pdfss/The_Challenge_to_Create_the_Space_Drive.pdf
Title: Re: EM Drive Developments
Post by: Mulletron on 12/08/2014 12:30 pm
Man this stuff is weird. I used to think I had the electron all figured out. Nope.

http://www.pbs.org/wgbh/nova/blogs/physics/2012/10/quantum-foam-virtual-particles-and-other-curiosities/

Title: Re: EM Drive Developments
Post by: Lampyridae on 12/08/2014 01:04 pm
Rodal: Thanx for the English summary comparison of Mull & White's take on their QV models.  It is  not clear to me what the phrase "medium with intrinsic momentum" means.  We all know that TV is called a medium because it is neither rare nor well done.  This sense of the term "medium" does not apply.

However, if the QV (which sounds more and more like an aether, if ya ask me) has "intrinsic momentum" which can be selectively manipulated, then it must have a direction.

If this analogy has any applicability, then along with turbulent wake, the aether QV must also feature "weather", "current", "tides", and what have you, all dependent on the anisotropic distribution of mass in the universe.

Since the QVF is "foam" in spacetime, then the currents and tides of it should be the local gravitational fields.

If there is anything that modifies the QVF's parameters, you're looking at some serious unexplored physics.
Title: Re: EM Drive Developments
Post by: Rodal on 12/08/2014 01:29 pm
I don't know how you could directly see what was happening at such a small scale. ...

Stupid question from the peanut gallery,...again. If we are looking at QVF are we not looking at Planck scale events? I thought that the virtual particle pairs were created and destroyed at the Planck scale. If so, yes the wake might be very short lived and very small. Just a question while I buy John some more peanuts in the intermission.

Don't confuse the scale of the "particles" with the scale of turbulence and eddies.  The scale of turbulence is much larger.  Also don't assume that turbulence is found by taking "a picture" of the motion of the "particles", instead what is measured in turbulence (of fluids, of superfluids, of plasma, of the solar wind, etc.)  is the time variation of field variables.  In this case, it would be the time variation of the magnetic field B, and the electric field E interacting with the EM Drive  Turbulence has to do with amplification of fluctuations.  We can tell about turbulence by examining the power spectral density and the autocorrelation of the field variables.  For example, by examining the power law scaling, as Mandelbrot for example showed time and time again in multiple examples.

See for example, the following (2012) paper on turbulence of the solar wind:

https://www.vsp.ucar.edu/Heliophysics/pdf/ChandranLWS_summer_school_turbulence_2012.pdf

I am on record as not being a sympathizer of the quantum vacuum explanations, particularly of Dr. White's plasma modeling of the quantum vacuum, but one must recognize that in his attempt to measure a wake (using another EM Drive) he is proceeding scientifically in another attempt to falsify his theory.

The proponents of the quantum vacuum producing propulsion of the EM Drive as a sail should also try to falsify their theory:  if they predict that virtual particles actually can interact with the real atoms of the EM Drive copper to transfer their momentum to the EM Drive copper, this interaction may leave a signature in the power spectrum power law scaling.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/08/2014 02:07 pm
I'm loosing feet with what is going on here with ME vs EM. Regarding the former, I understand Ron states it is not incompatible with GR, so not with SR, so not with Lorentz invariance. But it can predict the result of a situation that GR cannot predict, namely situation of a ME thruster thrusting. This "hole" in GR was never noticed because such prediction for such situation never needed, kind of, so possible Machian "extension" (?) to GR forgotten. How could it be that a mundane device like a ME thruster could leave classic frameworks GR + QFT voiceless ?

I think the answer here is to note that as I said, GR does not address the issue fo the origin of inertia.  Eistein liked Mach's explantion here.  He was in fact the one who coined the name, and it helped him form GR, but GR is not contingent upon Mach's Principle, so you would not expect to see GR extended to include inertia manipulation.  It was actually Dennis Sciama back in the 50's who first started connecting GR with MP.  Woodward merely followed Sciama's lead when he stumbled upon the surprise in the derivations that showed there was a way to manipulate inertia present.  He talks about this in detail in his book.

Quote
As for the higher order anisotropies... this looks like a nice playground, full of hills and hollows. What a GR compatible Machian physics would have to say different from what would say GR : local inertias don't care ? Anyway, it claims to predict an effect that is astounding for most people working with GR under the form of a ME thruster thrusting. Can't the theory devise one other type of experiment that is at least as astounding and that could lend itself to more convincing reproducible results ? Call it an experiment in fundamental science (à la Michelson and Morley). Better credibility to the theory if it can expose itself to experimental falsifiability on other grounds that notoriously capricious propellentless drives. Are there such other falsifiable grounds?
Woodward makes the argument in his book, which I chided him about for failing at the kinds of detail I would have liked, but basically his argument is that the flatness we observe with WMAP data, does indeed require that Mach's Principle be correct.  He says the issue is settled since WMAP.  It's a complex issue and again, I think he should have gone slower though the argument and would perhaps make a wonderful academic paper in and of itself, but I don't know if he took the jibe seriously.  I think he was writing again last summer but I don't know the subject or contents.

"Loosing feet with" sounds like an idiom from outside the English speaking world.  Can I ask where you're from?
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/08/2014 02:23 pm
I expect that Machian inertia researchers should have already addressed this issue more in depth and up-to-date than what I have seen, as it is important to completely address anisotropy of inertia vis-a-vis experiments to validate their theory.  Therefore I hope that the backers of Machian inertia can uncover better and up-to-date references to properly address the excellent point brought up by Mulletron.

I think they may have addressed the issue, and I'm not convinced the flatness of the universe isn't the issue--that anisotropy is only pertinent if you don't have flatness.  There's an interesting paper here:

http://www.haverford.edu/physics/dcross/research/papers/oral.pdf

That calls itself incomplete (one presumes because this is pre-WMAP), but seems to be addressing the issue, though I don't have time to read it right now.  Just saying from the short glance across that I made, it starts out addressing anisotropy and concludes with arguing about flatness and WMAP.  I think anisotropy may only matter so far as it concerns the gradient of the field.  If the field is flat, one wonders in what sense any anisotropy could make a difference.  But I haven't read the paper.  I can however recommend look at Woodward's book in this regard.  I haven't got time to search for the particular reference but I may later today.  Mullet, if you have an e-version, I suggest look for any WMAP references in the index and you'll find the discussion I'm thinking of pretty quickly.
Title: Re: EM Drive Developments
Post by: Rodal on 12/08/2014 02:30 pm
I expect that Machian inertia researchers should have already addressed this issue more in depth and up-to-date than what I have seen, as it is important to completely address anisotropy of inertia vis-a-vis experiments to validate their theory.  Therefore I hope that the backers of Machian inertia can uncover better and up-to-date references to properly address the excellent point brought up by Mulletron.

I think they may have addressed the issue, and I'm not convinced the flatness of the universe isn't the issue--that anisotropy is only pertinent if you don't have flatness.  There's an interesting paper here:

http://www.haverford.edu/physics/dcross/research/papers/oral.pdf

That calls itself incomplete (one presumes because this is pre-WMAP), but seems to be addressing the issue, though I don't have time to read it right now.  Just saying from the short glance across that I made, it starts out addressing anisotropy and concludes with arguing about flatness and WMAP.  I think anisotropy may only matter so far as it concerns the gradient of the field.  If the field is flat, one wonders in what sense any anisotropy could make a difference.  But I haven't read the paper.  I can however recommend look at Woodward's book in this regard.  I haven't got time to search for the particular reference but I may later today.  Mullet, if you have an e-version, I suggest look for any WMAP references in the index and you'll find the discussion I'm thinking of pretty quickly.

1) That's the same reference which I quoted.  It states that

"It remains to compare expansion coe±cients between the inertial mass and matter anisotropy at great
distance through the WMAP data of the CMB. From this comparison, limits can be set on
higher coe±cients to see whether these multipoles are accessible to observation."

2) Concerning flatness vs. anisotropy see this other reference I quoted:

Quote from:  http://cosmo.fis.fc.ul.pt/users/crawford/papers/swf_cqg.pdf

In this work it is shown that there are some spatially homogeneous
but anisotropic models
(Kantowski-Sachs and Bianchi type-III), with a positive
cosmological constant, for which the inhomogeneities in the distribution of matter on
the surface of the last scattering produce anisotropies (in large angular scales # »> 10±)
that do not di®er from the ones produced in Friedmann-Lemaitre-Robertson-Walker
(FLRW) models, if the density parameters are finely tuned.

3) Besides the issue of anisotropy and attempts to falsify Woodward's Machian theory by a more classical experiment (rather than EM Drives, as remarked by frobnicat) another issue with Woodward's Machian theory has to do with the instantaneous inertial effect due to most distant masses (Woodward proposed that this be addressed through Wheeler-Feynman_absorber_theory).

If the Machian effect is most importantly due to the most distant masses, and those masses can only  be observed in the distant past (due to the time that it has taken for their photons to reach us), how is the Woodward Machian theory capable of falsification if what would matter would be the instantaneous state of anisotropy of those distant masses?  (that instantaneous state of anisotropy being unobservable because those distant masses can only be observed with the delay due to the speed of light and their very large distance) ?
Title: Re: EM Drive Developments
Post by: SteveKelsey on 12/08/2014 02:39 pm
I am not sure you can conflate the turbulence created in the soler wind with the proposed QVF wake can you? The solar wind is composed of elementary particles which are of quite a different scale from the Planck levels involved in virtual particle production. I understand conceptually where you are going but I don't understand how the scale of the fields are independent of the scale constraints that apply to virtual particle production. My obsession with scale has nothing to do with John's craving for Virginia scale peanuts, which are also virtual at this point.
Title: Re: EM Drive Developments
Post by: Rodal on 12/08/2014 02:50 pm
I am not sure you can conflate the turbulence created in the soler wind with the proposed QVF wake can you? The solar wind is composed of elementary particles which are of quite a different scale from the Planck levels involved in virtual particle production. I understand conceptually where you are going but I don't understand how the scale of the fields are independent of the scale constraints that apply to virtual particle production. My obsession with scale has nothing to do with John's craving for Virginia scale peanuts, which are also virtual at this point.

Steve,

1)  it is Dr. White, himself (at the NASA Ames conference in August 2014) who has proposed as his next step to use another EM Drive to measure the wake left by the EM Drive undergoing propulsion.  So you have a disagreement with Dr, White in this regard.   As I said,  I am not defending the QV propulsion theory.  But his proposal is consistent with his theory


2) I don't think that one can simultaneously argue that the QV virtual particles can simultaneously produce directional propulsion (either as a propeller per Dr. White or as a sail as per Mull) by interacting with real copper atoms to transfer directional momentum and at the same time deny the possibility of amplification of the QV virtual particle fluctuations in this interaction resulting in turbulence that could be measured through the power spectrum of the interacting field variables.   One can either

A) deny QV directional momentum transfer to real particles (as done by most physicists at major institutions).  Hence there is no way to measure such turbulence of the QV. (The QV having no frame of reference to establish directional momentum).

B) But if you admit a macroscopic directional momentum transfer from the QV to the EM Drive then you must accept that such turbulence due to amplification should be measurable in the interacting field variables.
Title: Re: EM Drive Developments
Post by: SteveKelsey on 12/08/2014 03:42 pm
Thankyou Dr Rodal, I am going to opt for option A). as its a popular choice. I am with Ron on this one as I also understood the virtual particles had no inertial mass. However, if they carried a charge, then that would open up another direction to explore... 

John do you want your Virginians positive or negatively charged?

I agree that Dr White is proposing a useful falsification method and should be applauded for the effort.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/08/2014 04:17 pm
Rodal: Thanx for the English summary comparison of Mull & White's take on their QV models.  It is  not clear to me what the phrase "medium with intrinsic momentum" means.  We all know that TV is called a medium because it is neither rare nor well done.  This sense of the term "medium" does not apply.

However, if the QV (which sounds more and more like an aether, if ya ask me) has "intrinsic momentum" which can be selectively manipulated, then it must have a direction.

If this analogy has any applicability, then along with turbulent wake, the aether QV must also feature "weather", "current", "tides", and what have you, all dependent on the anisotropic distribution of mass in the universe.

Since the QVF is "foam" in spacetime, then the currents and tides of it should be the local gravitational fields.

If there is anything that modifies the QVF's parameters, you're looking at some serious unexplored physics.

I wouldn't take the leap that the QV has anything to do with gravity. Also, the recent talk about currents, tides, wind and turbulence doesn't compute. We're talking about the ground state of scalar and vector fields and vacuum fluctuations here. Not space weather.

The Dr. White proposal to use another thruster to measure the wake is commendable of course, but doesn't make any sense. A vacuum fluctuation lives and dies at extremely small scales. They never leave the resonant cavity. So he's got the right spirit, but that doesn't falsify anything. I'm working on a way to falsify the sail approach that doesn't simultaneously falsify the "pushing against the qv" approach. Honestly the "pushing against the qv" approach can be falsified with just logic, as has been done on this forum by me and others, as well as a recent paper on Arxiv.

Nobody has suggested you can modify any QV parameters. Nothing beyond the established Casimir effect that's been around since the 40s and measured experimentally. In this context, we're/I'm not worried about measuring any attractive/repulsive forces on the cavity walls; rather just the negative vacuum energy wrt the rest of the universe.

The QV doesn't transfer momentum to anything in everyday experience. For example, every electron in your body is being interacted with around all axes at once by these vacuum fluctuations, the net effect is a zero momentum transfer. The Brady et al paper stated the importance of the dielectric to the measured thrust. In order to get any momentum transfer, you have to create asymmetries. Which I have posted about many times.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/08/2014 04:25 pm
My friend isn't too keen on my planned experiments with a copper frustum and magnetron... :(
.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/08/2014 04:27 pm
Mach's principle states that the local inertial properies of matter are
determined by the global matter distribution in the universe.

Why did Woodward change it to flatness in his book? That isn't what Mach said at all. Is that moving the goal post after WMAP found things like the Eridanus Supervoid, and the Giant Void and other lumps, bumps and holes?

Seems if Mach's principle were right, I could drastically improve my golf game if I knew which constellation to aim at  ;)

I know his secret! I kid I kid.
(http://www.seth.com/images/collection_pages/memorabilia/47_pic7sm.jpg)

Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/08/2014 04:32 pm
I don't really see the difference. Woodward was just echoing the known observational evidence. The Universe is flat within a really small error bar. But it is anisotropic.
Title: Re: EM Drive Developments
Post by: Rodal on 12/08/2014 04:59 pm
Rodal: Thanx for the English summary comparison of Mull & White's take on their QV models.  It is  not clear to me what the phrase "medium with intrinsic momentum" means.  We all know that TV is called a medium because it is neither rare nor well done.  This sense of the term "medium" does not apply.

However, if the QV (which sounds more and more like an aether, if ya ask me) has "intrinsic momentum" which can be selectively manipulated, then it must have a direction.

If this analogy has any applicability, then along with turbulent wake, the aether QV must also feature "weather", "current", "tides", and what have you, all dependent on the anisotropic distribution of mass in the universe.

Since the QVF is "foam" in spacetime, then the currents and tides of it should be the local gravitational fields.

If there is anything that modifies the QVF's parameters, you're looking at some serious unexplored physics.

I wouldn't take the leap that the QV has anything to do with gravity. Also, the recent talk about currents, tides, wind and turbulence doesn't compute. We're talking about the ground state of scalar and vector fields and vacuum fluctuations here. Not space weather.

The Dr. White proposal to use another thruster to measure the wake is commendable of course, but doesn't make any sense. A vacuum fluctuation lives and dies at extremely small scales. They never leave the resonant cavity. So he's got the right spirit, but that doesn't falsify anything. I'm working on a way to falsify the sail approach that doesn't simultaneously falsify the "pushing against the qv" approach. Honestly the "pushing against the qv" approach can be falsified with just logic, as has been done on this forum by me and others, as well as a recent paper on Arxiv.

Nobody has suggested you can modify any QV parameters. Nothing beyond the established Casimir effect that's been around since the 40s and measured experimentally. In this context, we're/I'm not worried about measuring any attractive/repulsive forces on the cavity walls; rather just the negative vacuum energy wrt the rest of the universe.

The QV doesn't transfer momentum to anything in everyday experience. For example, every electron in your body is being interacted with around all axes at once by these vacuum fluctuations, the net effect is a zero momentum transfer. The Brady et al paper stated the importance of the dielectric to the measured thrust. In order to get any momentum transfer, you have to create asymmetries. Which I have posted about many times.

Based on my work on non-stationary randomness both in physics and in finance, what I understand you are stating, Mull, does not follow.  I understand that you are stating that the quantum vacuum which you have previously described as a random walk capable of being biased in a particular direction (by using a polymer with helical anisotropy for example) to transfer directional momentum to a macroscopic copper EM Drive such that it can be used for space propulsion yet you simultaneously state that the momentum transfer from the quantum vacuum to the EM drive would not produce any turbulent amplification of the quantum vacuum fluctuations.

I submit that the opposite is more likely: that (in the very unlikely event that) if there were any transfer of momentum from the quantum vacuum to a spacecraft through a EM Drive, such momentum transfer would not be flat in the  power spectral density but that there should be a measurable power decay in the power spectral density of the measured "thrust".
Title: Re: EM Drive Developments
Post by: Mulletron on 12/08/2014 05:05 pm
No the random walk of the electrons in the dielectric is biased. When you quote me, copy and paste my words. I have never even used the words "turbulent amplification."

https://www.youtube.com/watch?v=lWlkDXtUDgQ&list=UUrumw1oc1Tt8hL3jGFtXDMg
Read the description too.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/08/2014 05:05 pm


Based on my work on non-stationary randomness both in physics and in finance, what I understand you are stating, Mull, does not follow.  I understand that you are stating that the quantum vacuum which you have previously described as a random walk capable of being biased in a particular direction (by using a polymer with helical anisotropy for example) to transfer directional momentum to a macroscopic copper EM Drive such that it can be used for space propulsion yet you simultaneously state that the momentum transfer from the quantum vacuum to the EM drive would not produce any turbulent amplification of the quantum vacuum fluctuations.

I submit that the opposite is more likely: that (in the very unlikely event that) if there were any transfer of momentum from the quantum vacuum to a spacecraft through a EM Drive, such momentum transfer would not be flat in the  power spectral density but that there should be a measurable power decay in the power spectral density of the measured "thrust".

Simply because you can't lower zero point energy, but you can add to it, you should expect some sort of "wake".
Title: Re: EM Drive Developments
Post by: Mulletron on 12/08/2014 05:14 pm
By wake, you're assuming some sort of fluid like behavior. This isn't water or an aether. Picture the "snow" on an old tv set.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/08/2014 05:16 pm
That random walk doesn't seem to go anywhere

Exactly. That's why we're not being pushed around by the QV. Now put that scenario in the video in the Shawyer cavity.
Title: Re: EM Drive Developments
Post by: Rodal on 12/08/2014 05:17 pm


Based on my work on non-stationary randomness both in physics and in finance, what I understand you are stating, Mull, does not follow.  I understand that you are stating that the quantum vacuum which you have previously described as a random walk capable of being biased in a particular direction (by using a polymer with helical anisotropy for example) to transfer directional momentum to a macroscopic copper EM Drive such that it can be used for space propulsion yet you simultaneously state that the momentum transfer from the quantum vacuum to the EM drive would not produce any turbulent amplification of the quantum vacuum fluctuations.

I submit that the opposite is more likely: that (in the very unlikely event that) if there were any transfer of momentum from the quantum vacuum to a spacecraft through a EM Drive, such momentum transfer would not be flat in the  power spectral density but that there should be a measurable power decay in the power spectral density of the measured "thrust".

Simply because you can't lower zero point energy, but you can add to it, you should expect some sort of "wake".


Excellently stated.  Also, the "wake" should have "less disorder", "less randomness" than the absolute randomness (randomness at all time scales) of the zero point energy.  This should be observable in the power spectral density.
Title: Re: EM Drive Developments
Post by: Rodal on 12/08/2014 05:20 pm
By wake, you're assuming some sort of fluid like behavior. This isn't water or an aether. Picture the "snow" on an old tv set.

The power spectral density of "snow" in an old TV set is not flat !

Actually Mandelbrot used many types of noise found in electronics to describe the statistical order of different types of randomness.  For example 1/f noise, shot noise, pink noise.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/08/2014 05:22 pm
If the Machian effect is most importantly due to the most distant masses, and those masses can only  be observed in the distant past (due to the time that it has taken for their photons to reach us), how is the Woodward Machian theory capable of falsification if what would matter would be the instantaneous state of anisotropy of those distant masses?  (that instantaneous state of anisotropy being unobservable because those distant masses can only be observed with the delay due to the speed of light and their very large distance) ?
If I understand your question, it is basically how do we falsify the reaction on the rest of the universe.  I don't personally know how to do that save to note the accelerated expansion, which is the expected result of harvesting momentum.  Since we don't have a proposed mechanism for dark energy, M-E seems to be the only viable candidate, but that is not the same as providing for falsification.  So I'm not sure your question has an answer.

This is really akin to the whole "a closed universe cannot rotate" issue.  How would you measure?  We can and do measure the expansion rate and it is increasing, but if it were not we could not then say (hey there's no back reaction" since we don't know what the magnitude of the reaction ought to be, since we don't in fact know what the magnitude of M-E usage throughout the time of the universe will be.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/08/2014 05:23 pm
Indeed can you show me anything that is spectrally flat?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/08/2014 05:26 pm
By wake, you're assuming some sort of fluid like behavior. This isn't water or an aether. Picture the "snow" on an old tv set.

By "wake" I'm assuming some sort of propagating  residual field distribution.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/08/2014 05:27 pm
I thought the standard GR showed that the Universe is not rotating... Forgive me if I am wrong
Title: Re: EM Drive Developments
Post by: Rodal on 12/08/2014 05:58 pm
I thought the standard GR showed that the Universe is not rotating... Forgive me if I am wrong
Yes, it depends on how one defines rotation of the Universe.  The rotating Godel universe model, for example, can be shown to not satisfy experiments but other types of "rotation" are still possible.  Usually these types of "rotation" refer to quantities defined not by the overall space-time but by a local slicing of the space-time.  Another issue is that while these types of rotation can be included and the model "improves" in some sense many physicists think that the great increase in complexity of including such rotation modeling  is not justified by the meager increase in improvement.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/08/2014 06:06 pm
Thanks Rodal. So we are not rotating then. ME seems plausible to me, the universe is not isotropic.
Title: Re: EM Drive Developments
Post by: frobnicat on 12/08/2014 06:07 pm
I'm loosing feet with what is going on here with ME vs EM. Regarding the former, I understand Ron states it is not incompatible with GR, so not with SR, so not with Lorentz invariance. But it can predict the result of a situation that GR cannot predict, namely situation of a ME thruster thrusting. This "hole" in GR was never noticed because such prediction for such situation never needed, kind of, so possible Machian "extension" (?) to GR forgotten. How could it be that a mundane device like a ME thruster could leave classic frameworks GR + QFT voiceless ?

I think the answer here is to note that as I said, GR does not address the issue fo the origin of inertia.  Eistein liked Mach's explantion here.  He was in fact the one who coined the name, and it helped him form GR, but GR is not contingent upon Mach's Principle, so you would not expect to see GR extended to include inertia manipulation.  It was actually Dennis Sciama back in the 50's who first started connecting GR with MP.  Woodward merely followed Sciama's lead when he stumbled upon the surprise in the derivations that showed there was a way to manipulate inertia present.  He talks about this in detail in his book.


Thank you for the answer, but as expected in the question I don't find it satisfying. I won't read the book, main reason being I feel I should study complete and solid GR course first (and no time nor priority so far), so if you are getting tired of playing the popularization game for not enough involved audience I would understand.

So, with all my (admitted) shortcomings in understanding GR, seems to me it hasn't to be "extended" to predict that the total mass-energy content of a bulk material wont vary by a iota while it's vibrating (under harmonic self oscillations) : energy is swapping between kinetic energy and elastic energy in the intermolecular bonds but is the same magnitude, has the same gravitational pull, has the same inertia. "Inertia manipulation" would be just a particular configuration of accelerations and energy swapping between different forms, in a locally quite flat space-time, how could this be beyond the scope of GR as far as inertia is concerned ? Say for instance we study a battery, from empty, charging it will add mass_energy to it. The gained mass (say gravitational, as measured by weight on a scale) will be quite low but is clearly not 0 and predicted by SR, delta_m=delta_E/c² (sorry for the triviality). Now make an internal short-circuit so that this chemical potential energy discharges quickly, and converts to thermal agitation. There is no net gain nor loss of energy to the outside, so the hot depleted battery will weigh exactly as much as when cold and charged.

What is the aspect of an experiment of "inertia manipulation" that escapes this aptitude of SR (we don't even need GR here) of simply predicting that inertial mass amounts just to mass_energy content, and that a closed bulk system wont see any change in inertial mass, whatever happens inside ? And that an open bulk system can see a change in mass_energy content but only as much as mass_energy flow it incurs, and such flow will bring/carry away an equivalent momentum than would allow to "push heavy pull light", so we are left with 0 net thrust in the end ?

I can understand such Machian physics could predict such inertia manipulation, different from what SR would predict, but not how SR would fail to predict anything at all ! I mean, just show ME thruster design (and its internal power dynamics...) to a good physicist who don't know what it's supposed to do, you really think he/she will scratch head for a few days and conclude "how strange, we need an extended theory of inertia to predict how it will behave, classical frameworks have nothing to tell !"  Really ?

Quote
Quote
As for the higher order anisotropies... this looks like a nice playground, full of hills and hollows. What a GR compatible Machian physics would have to say different from what would say GR : local inertias don't care ? Anyway, it claims to predict an effect that is astounding for most people working with GR under the form of a ME thruster thrusting. Can't the theory devise one other type of experiment that is at least as astounding and that could lend itself to more convincing reproducible results ? Call it an experiment in fundamental science (à la Michelson and Morley). Better credibility to the theory if it can expose itself to experimental falsifiability on other grounds that notoriously capricious propellentless drives. Are there such other falsifiable grounds?

Woodward makes the argument in his book, which I chided him about for failing at the kinds of detail I would have liked, but basically his argument is that the flatness we observe with WMAP data, does indeed require that Mach's Principle be correct.  He says the issue is settled since WMAP.  It's a complex issue and again, I think he should have gone slower though the argument and would perhaps make a wonderful academic paper in and of itself, but I don't know if he took the jibe seriously.  I think he was writing again last summer but I don't know the subject or contents.

"Loosing feet with" sounds like an idiom from outside the English speaking world.  Can I ask where you're from?

Yes, not far off  England coasts but still not native speaker for sure, I'm French actually. "Perdre pied" (loosing foot, rather than feet...) meaning you can no longer reach the bottom with feet when standing in water. It's used as a way to admit you don't swim well and are no longer in a zone of comfort, and likely not to follow a particular lead but rather to drown swiftly. Beyond swimming... you get the picture, metaphorically.

I'm sure a lot of people have other conclusions to draw than correctness of Mach principle from the apparent flatness on cosmological scales. The question was rather, what other lab experiments could be devised to check for the reality or falsify Machian theory ? Is a ME thruster the most simple arrangement where such effect would manifest ? Someone send me a life jacket please.
Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/08/2014 06:18 pm
I guess it is up to us to perform experiments.
It will only give us rough data points but so what!
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/08/2014 07:30 pm
Mach's principle states that the local inertial properies of matter are
determined by the global matter distribution in the universe.

Why did Woodward change it to flatness in his book? That isn't what Mach said at all.
He didn't change anything.  I thought you had the book?
Title: Re: EM Drive Developments
Post by: Rodal on 12/08/2014 07:43 pm
By wake, you're assuming some sort of fluid like behavior. This isn't water or an aether. Picture the "snow" on an old tv set.

By "wake" I'm assuming some sort of propagating  residual field distribution.

which also deteriorates  or damp[ens over time, and is ultimately at a much larger "scale" than the thing which caused the disturbance, whether a propeller or a sail.

Besides, Mull's outright dismissal of any possible description of the quantum vacuum as a superfluid has no basis in physics as discussed at major institutions, see for  example http://en.wikipedia.org/wiki/Superfluid_vacuum_theory. None other than the great Paul Dirac inspired this approach.

As to scale, I already addressed that, and I'm content with the fact that none other than the great Feynman suggested quantized vortex lines:
see http://en.wikipedia.org/wiki/Quantum_turbulence  (actually quantum turbulence is much simpler to model than classical turbulence in fluids like water)

Winterberg proposed that the quantum vacuum is a kind of superfluid plasma compound of positive and negative Planck masses, called a Planck mass plasma.  Here is a 2013 paper by him:  http://aflb.ensmp.fr/AFLB-381/aflb381m775.pdf  where he proposes the following experimental verification:


Quote from:  Winterberg
In performing an EPR experiment, a wormhole would be opened between the two
entangled particles, keeping their quantum mechanical phases the same.
Now suppose that intense laser light is projected on that part of the screen
where one of the entangled particles is expected to emerge and be measured.
Under these conditions a laser signal might be seen on the other screen
where the other entangled particle is expected to emerge, with the laser signal
having passed through the wormhole made by the entangled particles.

   How do electromagnetic waves, photons etc. move through space, where there is believed to be nothing?  Several prominent scientists have suggested and continue to suggest that it is in fact a superfluid.  But you, Fornaro, are allowed to called it the aether.


Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/08/2014 08:53 pm
By wake, you're assuming some sort of fluid like behavior. This isn't water or an aether. Picture the "snow" on an old tv set.

By "wake" I'm assuming some sort of propagating  residual field distribution.

which also deteriorates  or damp[ens over time, and is ultimately at a much larger "scale" than the thing which caused the disturbance, whether a propeller or a sail.

I would say dissipates, but aether one will do for the local description.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/08/2014 09:14 pm
Thank you for the answer, but as expected in the question I don't find it satisfying. I won't read the book, main reason being I feel I should study complete and solid GR course first. . .
The  book is written specifically for engineers.  I'm sure you can understand what's in there.  The equations are all there too, but they're mostly endnoted and on those occasions they are in the text, the text makes perfect sense without them.  Though you are investing a little trust that the equations are correct, the fact they're peer reviewed for 20 years with no objections, and that the book is now about 2 years old with no objections from the academic community, is pretty consoling to me.  Remember it was published by Springer--an educational publishing house, and it has been reviewed now by academics all over.  I have not yet seen a rebuttal of any kind.  Of course that could change tomorrow.


Quote
"Inertia manipulation" would be just a particular configuration of accelerations and energy swapping between different forms. . .

Not at all.  Mass fluctuations are actually radiation reactions that suffer a time delay.  The best way to visualize it is that there is a "gravinertial flux" formed by the gravity of the universe, that produces inertia, and that this flux can be made to flow in and out of matter under specific conditions.  The energy in the bonds is necessary, because it is the change in those energies combined with acceleration that gives rise to the fluctuation.

Quote
I can understand such Machian physics could predict such inertia manipulation, different from what SR would predict, but not how SR would fail to predict anything at all !
Like GR, SR is not a theory of inertia.  You might just as well object that we don't find this in Bernoulli's Principle.  It does not pertain.

Quote
I mean, just show ME thruster design (and its internal power dynamics...) to a good physicist who don't know what it's supposed to do, you really think he/she will scratch head for a few days and conclude "how strange, we need an extended theory of inertia to predict how it will behave, classical frameworks have nothing to tell !"  Really ?
  Certainly not.  Without understanding the physics behind the device, no one would have any idea what it is supposed to do, nor why.

Quote
Can't the theory devise one other type of experiment that is at least as astounding and that could lend itself to more convincing reproducible results ?
Yes.  Woodward did the M-E experiment back in 2008-9 where he fluctuated the mass of a ceramic on a "Rotator" but did not rectify the fluctuation into useful force.  He merely detected the fluctuation and noted it was as predicted, at twice the frequency of the power into the device.  Years before that he measured the time averaged loss of mass in one of the original design thrusters as predicted by theory, on his modified U-80 load cell.  There isn't one experiment that's been done.  There are half a dozen such experiments. 

The important thing that hasn't been done so far as I'm concerned, is a high quality thruster experiment done at sufficient frequency that we see commercial grade thrusts.  IMHO, what is needed now is a commercial thruster with thrust to mass, thrust to power and temperature bandwidth figures of merit that makes the device useful and can for example be run continuously and have its thrust reversed easily on command by altering the phase angle between the 1w and 2w components of the drive signal.  There's been quite enough useless proof of science.  If that's what you really want is proof of science, read the book.  That's what the second third of the book is all about.  And really if that's what you are all about asking, what excuse could you possibly have to not go get the answers yourself?

Quote
The question was rather, what other lab experiments could be devised to check for the reality or falsify Machian theory ? Is a ME thruster the most simple arrangement where such effect would manifest ?
In some ways the thruster is the most simple.  It adds to the Rotator experiment the requirement to oscillate at 2 frequencies instead of just one, and to measure reliably some very small thrusts, but the Rotator has different issues.  While such an experiment removes the thrust measurement requirement, it adds things like spinning the caps at several hundred gees without suffering explosive decomposition, and feeding the power through a set of expensive slip rings.  It's a toss up which is the simpler.  My contention before the Rotator tests was that people would not care what he predicted and found, because he was not demonstrating a useful technology, but rather just a proof of science.  I think that was an accurate prediction on my part.  People don't care about stuff that isn't useful, and most people are far too skeptical to be convinced by mere proof of science.  Take for example the folks here--they don't want to look at the data, so what is the point in proof of science?  Take note too of NASA's official word on the subject through their point man in propulsion investigations, Dr. Dennis Bushnell.  According to Dennis, NASA does not have the physicists to vet the theory properly (like us here) so what he wants to see is higher thrust.  NASA even hired a team from The Aerospace Company to do an investigation, but they also do not have the proper physicists to do the field theory, so all they did was another warmed over engineering look.   Given one cannot grapple directly with theory, the only thing left is observation and I think the observations would weigh a lot more, were they of a useful thrust.  That means we need a commercial thruster.  We could do this on far less money than was thrown away on the Shawyer resonator in the UK or the recent tests at Eagleworks, none of which explain themselves with plausible theory.  The problem is, this industry gets treated as a good old boys club, and the boys in the club, like Sonny, get the funds.  It doesn't matter they can't explain themselves satisfactorily.

We need useful thrust.
Title: Re: EM Drive Developments
Post by: Rodal on 12/08/2014 09:40 pm

... the book is now about 2 years old with no objections from the academic community, is pretty consoling to me.  Remember it was published by Springer--an educational publishing house, and it has been reviewed now by academics all over.  I have not yet seen a rebuttal of any kind.  Of course that could change tomorrow.
  (bold added for emphasis)

Motivated by what you just wrote, I went looking into Google for a review of this book in a physics or scientific journal.  I did not find such a review, but if you know of a link to a review of this book in a physics or scientific journal, I would appreciate it.

Curiously though, what I just found is that by Googling"Making Starships and Stargates", the number 4th entry in Google  (directly above the youtube video of Woodward) is what appears to be the whole book posted by an organization (from Iran or an Arabic country ? -the language appears Arabic or Iranian, I don't know) that posted this whole book (296 pages) in a pdf format.   

QUESTION: Is that pdf really of the 296 pages long book you are referring to?

Please check it, and if indeed if it is a pdf of Woodward's book, you  (since you appear to have direct access to Woodward) may want to notify Woodward and/or Springer to approach Google as an author or copyright owner to tell Google to take this link out as a violation of the author's copyright
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/08/2014 10:28 pm
Thanks much for that.  I shot Jim and Heidi notes about the link.  Yes, that's the book.

Concerning reviews, last I talked with Jim was about 7 months ago, and at that time he already had about a dozen positive reviews and no negative ones.  I think he was collecting them for the second edition.  I am not aware of anyplace they're posted online, but I know some big names whom should stay anonymous for now have read the book with great interest. 

I can tell you, just after he submitted it to the publisher, he started to have second thoughts because he expected to be lambasted by the academic community and so far as I'm aware, there just has not been that sort of reaction.  I can tell you one positive response (because it was posted to Jim's general reading list) was from Carver Mead from MIT, who I think is endorsing the work to some degree.  He actually called Jim and asked to meet with him.  So the response has been pretty excellent I'd say.
Title: Re: EM Drive Developments
Post by: frobnicat on 12/08/2014 11:53 pm
Thank you for the answer, but as expected in the question I don't find it satisfying. I won't read the book, main reason being I feel I should study complete and solid GR course first. . .
The  book is written specifically for engineers.  I'm sure you can understand what's in there.  The equations are all there too, but they're mostly endnoted and on those occasions they are in the text, the text makes perfect sense without them.  Though you are investing a little trust that the equations are correct, the fact they're peer reviewed for 20 years with no objections, and that the book is now about 2 years old with no objections from the academic community, is pretty consoling to me.  Remember it was published by Springer--an educational publishing house, and it has been reviewed now by academics all over.  I have not yet seen a rebuttal of any kind.  Of course that could change tomorrow.
Mmm, in this context I grant you it looks like it's devoid of the theoretical enormities of Shawyer, White... but this is precisely because of that I'd like to have a firmer grasp on the relevant admitted theory first, to make an informed lecture. If this sounds like a poor excuse (it is), again, I would understand you gave up in answering my posts. Meanwhile I do enjoy talking with someone who read it and can interactively respond to the questions of a sceptic engineer passerby. Take it as an exercise to find the right words to convince a typical reluctant science aware community member of the value of those ideas, which are tremendous if correct.
All right, at some point I will read it.

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"Inertia manipulation" would be just a particular configuration of accelerations and energy swapping between different forms. . .

Not at all.  Mass fluctuations are actually radiation reactions that suffer a time delay.  The best way to visualize it is that there is a "gravinertial flux" formed by the gravity of the universe, that produces inertia, and that this flux can be made to flow in and out of matter under specific conditions.  The energy in the bonds is necessary, because it is the change in those energies combined with acceleration that gives rise to the fluctuation.

Ok, here we are. Great you take time and effort to understand what I'm not understanding. I will try to refine what is still not entering my skull : in what those conditions are so specific that they can't be stated GR wise ? From SR there is nothing magic with energy in bonds, this is just energy, I tried to illustrate that with the battery example. Cold charged battery, hot depleted battery, same energy, same mass equivalence, no mass fluctuation. "The energy in the bonds is necessary, because it is the change in those energies..." so there is change in chemical bonds energy, but that does not equate to change in energy density in the bulk, this is just a different form of energy (from chemical to kinetic and reverse, millions times a second). There is no net output or input flow of energy in such harmonic motion (putting aside the decay to thermal agitation). SR is not saying that one form of energy is heavier than another form in such closed system, it does say that it is the same. GR might say that if a closed system has transformation in energy forms that imply fast velocities of close ultradense objects then it could emit significant gravity waves, it would no longer be closed in that sense, and could "thrust" in given direction but probably at the expense of more than 3E8 Watts per Newton I guess.

Visualizing a "gravinertial flux" won't help. I guess it is backed by equations of state in Woodward's book (?). "...that this flux can be made to flow in and out of matter under specific conditions" sounds to me like it would transfer all the "gains" that could be made in terms of "push heavy pull light" from one part of a closed system to another part of the same closed system, with no net thrust overall. If this flux gets outside, we have an open system, and SR states that the price is equal or more than 3E8 Watts per Newton.

Time delays seem irrelevant for transformation from chemical bonds energy to kinetic energy back and forth in a bulk, again my battery example (please comment the battery thing : right ? wrong ? irrelevant ? Why irrelevant since it's about conversion from chemical bond energies to kinetic energies in a bulk ?)

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I can understand such Machian physics could predict such inertia manipulation, different from what SR would predict, but not how SR would fail to predict anything at all !
Like GR, SR is not a theory of inertia.  You might just as well object that we don't find this in Bernoulli's Principle.  It does not pertain.

Er, mmm, it (SR+GR) might not explain the origin of mass as deriving from more fundamental "entities", but it does speak a little bit about inertia, if anything else, from an effective point of view, that is it allows a number of predictions about how something will accelerate or not (relative to inertial frame, say, in deep flat space) given what it does with its mass_energy content (throwing some of it or not). Bernoulli, with all due respect, was not working on a fundamental (effective) theory of dynamics, unlike GR or Newtonian dynamics.

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I mean, just show ME thruster design (and its internal power dynamics...) to a good physicist who don't know what it's supposed to do, you really think he/she will scratch head for a few days and conclude "how strange, we need an extended theory of inertia to predict how it will behave, classical frameworks have nothing to tell !"  Really ?
  Certainly not.  Without understanding the physics behind the device, no one would have any idea what it is supposed to do, nor why.
Certainly not what ? I'm not asking if such mainstream scientists could tell what it is supposed to do, I'm asking if they could give a prediction of what it will do from admitted frameworks (no net thrust, at least not more than power/c would be my prediction, but I'm not a top notch senior physicist) or meet inconsistencies in the equations or interpretation so specific that they know they have reached the limits of usual frameworks.

Sorry if this sounds rude but : you are trying to sell a Machian physic as fully compatible with GR, only extending it (saying the same things in the same configurations, only being able to tell more things, like you could say that Newtonian dynamics is fully compatible with Bernoulli's principle) while it appears to your average engineer that this Machian physic is not compatible with SR, it predicts things in a situation where SR clearly predicts also, and a different result. This would be alright, experiment then can tell apart one from the other. Like experiment could tell apart Newtonian from SR, two incompatible theories.

But all this "Mach compatible with SR" makes no sense, at least the way you explain it excuse me, no matter the number of references you throw at it. If such Mach theory is compatible with SR, it will predict the same thing as SR in the same situation where SR does predict. And SR does predict "closed system in deep space => no departure from inertial trajectory", so SR compatible Mach theory should say the same, me think.

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Can't the theory devise one other type of experiment that is at least as astounding and that could lend itself to more convincing reproducible results ?
Yes.  Woodward did the M-E experiment back in 2008-9 where he fluctuated the mass of a ceramic on a "Rotator' but did not rectify the fluctuation into useful force.  He merely measured the fluctuation and noted it was as expected, at twice the frequency of the power into the device.  Years before that he measured the time averaged loss of mass in one of the original design thruster as predicted by theory, on his modified U-80 load cell.  There isn't one experiment that's been done.  There are half a dozen such experiments. 

The important thing that hasn't been done so far as I'm concerned, is a high quality thruster experiment done at sufficient frequency that we see commercial grade thrusts.  IMHO, what is needed now is a commercial thruster with thrust to mass, thrust to power and temperature bandwidth figures of merit that makes the device useful and can for example be run continuously and have its thrust revered easily on command by altering the phase angle between the 1w and 2w components of the drive signal.  There's been quite enough useless proof of science.  If that's what you really want is proof of science, read the book.  That's what the second third of the book is all about.  And really if that's what you are all about asking, what excuse could you possibly have to not go get the answer yourself?

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The question was rather, what other lab experiments could be devised to check for the reality or falsify Machian theory ? Is a ME thruster the most simple arrangement where such effect would manifest ? Someone send me a life jacket please.
In some ways the thruster is the most simple.  It adds to the Rotator experiment the requirement to oscillate at 2 frequencies instead of just one, and to measure reliably some very small thrusts, but the Rotator has different issues.  While such an experiment removes the thrust measurement requirement, it adds things like spinning the caps at several hundred gees without suffering explosive decomposition, and feeding the power through a set of expensive slip rings.  It's a toss up which is the "simpler".  My contention before the Rotator tests was that people would not care what he predicted and found, because he was not demonstrating a useful technology, but rather just a proof of science.  I think that was an accurate prediction on my part.  People don't care about stuff that isn't useful, and most people are far too skeptical to be convinced by mere proof of science.  Take for example the folks here--they don't want to look at the data, so what is the point in proof of science? 

We need useful thrust.

Mmm, folks here have varying motivations and knowledge and skills. But the scientific world is huge and avid of proof of beyond standard frameworks, especially if they can be put at test inside a small lab. I worked in a lab (different topic) and I know reality of science is far from idealisations. But, for your average engineer knowing scientists, this is still beyond belief that a well put, reproducible proof of science, below 1000k$ could remain so widely ignored as not spreading exponentially. This would be as mysterious as Fermi paradox. Obviously your average engineer with a scope on advanced concepts would be as well convinced by 10 major labs reproducing a "useless" proof of new science than by one useful tech demo in a garage. Folks want to look at data from different sources. Not a dozen experiment from the same team, but the same experiment (and same consistent results) from a dozen team. Then people would care. Even if you levitated an elephant in front of an audience of 1000s at burning man festival, this one spectacular demo would lend less credibility to the tech than spreading a reproducible design of proof of science that barely moves a dust, but does so consistently and beyond doubt. But I'm not in this business, so maybe wrong.

Any online papers about the rotator "proof of science" oriented experiments ? I do care about that...
Title: Re: EM Drive Developments
Post by: 93143 on 12/09/2014 01:38 am
Cold charged battery, hot depleted battery, same energy, same mass equivalence, no mass fluctuation.

As I understand it, energy is actually flowing in and out of the capacitor, and it is the capacitor, not the whole local system, that undergoes the precisely synchronized accelerations.

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If this flux gets outside, we have an open system, and SR states that the price is equal or more than 3E8 Watts per Newton.

The Mach effect involves the whole universe being active.  The thruster isn't just sending energy out at the speed of light; it's also receiving it from everything inside its cosmic horizon.  So the 3e8 W/N limit doesn't apply, any more than a laser sail vehicle would have to generate all the power for the drive beam, rather than for just the little communications laser that allows it to lock on.

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Time delays seem irrelevant for transformation from chemical bonds energy to kinetic energy back and forth in a bulk, again my battery example (please comment the battery thing : right ? wrong ? irrelevant ? Why irrelevant since it's about conversion from chemical bond energies to kinetic energies in a bulk ?)

The time delay in question is the time required to communicate with the distant matter.  The result is that it is the far-future distant universe that is being interacted with.  (This is where Wheeler-Feynman reaction radiation and Cramer's transactional interpretation of QM are brought in.)

Note that this interaction is implicit, not explicit, in the original derivation, since AIUI the derivation is based on local gravitational potential.  I don't think advanced waves are necessarily inherent in the concept, but that's how it's currently described, and it certainly solves a lot of problems.

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Certainly not what ? I'm not asking if such mainstream scientists could tell what it is supposed to do, I'm asking if they could give a prediction of what it will do from admitted frameworks (no net thrust, at least not more than power/c would be my prediction, but I'm not a top notch senior physicist) or meet inconsistencies in the equations or interpretation so specific that they know they have reached the limits of usual frameworks.

Can a physicist predict the viscosity of an emulsion of two multicomponent liquids, from first principles?

Of course not.  It's far too complicated.  I wouldn't even expect a correct qualitative description from someone who had never thought about it before.

Heck, if we're discussing Bernoulli and his Principle, let's not forget that it's a good example of how fluid dynamicists of that era completely missed the whole concept of viscosity, or at least all of its practical implications.  Engineers (and anyone who had ever tried to pour molasses) decided the mathemagicians' results were a load of trash and developed the purely experimental science of hydraulics, and viscosity was the key to reuniting them.

In this case, it is claimed that GR has an implication most physicists (not all) have missed, and in our universe it translates under ordinary circumstances into something they have tended to take for granted without explanation: inertia.  The subtleties of how it behaves under certain fairly extreme and very specific circumstances cannot be expected to be obvious to someone who has not understood the nature of the phenomenon in the first place.

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you are trying to sell a Machian physic as fully compatible with GR

No.  Unless I'm much mistaken, the claim is that in the context of an FRW cosmology, Machian inertia is derivable from GR.  Full stop.  Mach's principle is not an addition to the physics that enables you to do this; it's an idea that you follow in order to discover this in the original physics.

GR is very complicated and has not been thoroughly explored, and this situation is not helped by the widespread perception that QM has rendered it obsolete.

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And SR does predict "closed system in deep space => no departure from inertial trajectory", so SR compatible Mach theory should say the same, me think.

The whole point is that the thruster is not a closed system.  And SR is not general enough to predict this, though if it is given the fact as input it will produce correct results within its sphere of competence.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/09/2014 08:47 am
That random walk doesn't seem to go anywhere
Now put that scenario in the video in the Shawyer cavity.

Gazakly.  Which gets back to asking again what a "medium with intrinsic momentum" means.

Who put "medium with intrinsic momentum" out there? Wasn't me. It was:
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1299536#msg1299536

I want to be clear, I will only defend statements made by me. Not what other people think I think, or interpret from what I say. Just what I say.

I am not going to reinterpret the QV or try and bring back the luminiferous aether or treat it as a wind or fluid and contravene over a hundred years of science and SR. The QV is what it is, regardless if it is understood or not.

It is comforting to think of things like this as an aether or wind, from our human tendencies to compare things to our usual everyday experience.

The term aether has a lot of negative connotations and implies opposition to established science. It implies a medium that is necessary for light to propagate. Just because space is filled with a Dirac sea of particles, doesn't mean that this is a necessary medium required for light or anything else to propagate.
Put very nicely here:
http://en.wikipedia.org/wiki/Aether_theories#Quantum_vacuum

So call it an aether if you like. I won't. It is taboo and will definitely make people roll their eyes and not take what you're saying seriously.

My actual words are, "....these fluctuations don't have a defined or net momentum." There is no net momentum transfer without finding a way to break that symmetry. I based that off of many things such as this: http://ned.ipac.caltech.edu/level5/March02/Sahni/Sahni5.html

My entire reading list is on the google drive in the bookmarks doc.

In plain English for clarity, If you're getting blasted from all sides equally, there is no momentum transfer.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/09/2014 09:38 am
Mach's principle states that the local inertial properies of matter are
determined by the global matter distribution in the universe.

Why did Woodward change it to flatness in his book? That isn't what Mach said at all. Is that moving the goal post after WMAP found things like the Eridanus Supervoid, and the Giant Void and other lumps, bumps and holes?

He didn't change anything.  I thought you had the book?

Page 37, 42, 53...54. He is not giving any credance to the non uniform distribution of matter in the universe and is instead diverting over to the flatness of spacetime at large scales (and it isn't perfectly flat, yet inertia is not biased. This flatness isn't even the product of JUST the matter in the universe, also the vacuum.

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Since we don't have a proposed mechanism for dark energy, M-E seems to be the only viable candidate, but that is not the same as providing for falsification.
Citation needed. What about the cosmological constant problem? What about vacuum energy?

Ron, it is as simple as this, M-E isn't the only game in town. See page 5 here: http://arxiv.org/ftp/arxiv/papers/1101/1101.1063.pdf There are many ideas out there which could get us to the stars.

Don't come here and try to act as if it is, by accusing others like Eagleworks of falsifying data, picking on Dr. McCulloch, and accusing me of misleading people. I'd prefer to just let you be and not draw unwanted critical attention to M-E. For example, if you google "gravinertial flux" you'll quickly see that isn't a real thing.

This thread isn't an opportunity to threadjack and advertise a book. It is about advanced propulsion. EMdrive developments.... Not Woodward's book or bust.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/09/2014 10:37 am
By wake, you're assuming some sort of fluid like behavior. This isn't water or an aether. Picture the "snow" on an old tv set.

By "wake" I'm assuming some sort of propagating  residual field distribution.

...which also deteriorates  or dampens over time, and is ultimately at a much larger "scale" than the thing which caused the disturbance, whether a propeller or a sail.

1) Besides, Mull's outright dismissal of any possible description of the quantum vacuum as a superfluid has no basis in physics as discussed at major institutions, see for  example http://en.wikipedia.org/wiki/Superfluid_vacuum_theory. None other than the great Paul Dirac inspired this approach.

2) As to scale, I already addressed that, and I'm content with the fact that none other than the great Feynman suggested quantized vortex lines:
see http://en.wikipedia.org/wiki/Quantum_turbulence  (actually quantum turbulence is much simpler to model than classical turbulence in fluids like water)

3) Winterberg proposed that the quantum vacuum is a kind of superfluid plasma compound of positive and negative Planck masses, called a Planck mass plasma.  Here is a 2013 paper by him:  http://aflb.ensmp.fr/AFLB-381/aflb381m775.pdf  where he proposes the following experimental verification:

Quote from:  Winterberg
In performing an EPR experiment, a wormhole would be opened ...

4) How do electromagnetic waves, photons etc. move through space, where there is believed to be nothing?  Several prominent scientists have suggested and continue to suggest that it is in fact a superfluid.  But you, Fornaro, are allowed to call it the aether.

4)  Many thanks for that. 

The aether, as conceived in classical physics leads to several contradictions; in particular, aether having a definite velocity at each space-time point will exhibit a preferred direction. (http://en.wikipedia.org/wiki/Superfluid_vacuum_theory#History)

What can "intrinsic momentum" mean, if it does not include a "preferred direction"?

If the energies and momenta are below the excitation threshold then the superfluid background behaves like the ideal fluid, therefore, the Michelson–Morley-type experiments would observe no drag force from such aether. (http://en.wikipedia.org/wiki/Superfluid_vacuum_theory#Lorentz_and_Galilean_symmetries)

Therefore, if it does have a "preferred direction", it wouldn't result in a "drag force" on light.  Aether way, cough, guess what it would be called?

I'm just askin' the questions here, 'cause typically, I'm the guy giving the Dbug salute, when I'm not engaged in all those deletable activities I'm apparently fond of photographing and posting.

3) This so-called experimental verification is, well, not benign.   "A wormhole would be opened..."?  Seriously?

2) As to scale, I point to the submarine graphic you posted earlier. The propellor (EM drive) is but so big geometrically.  The "turbulent wake" in either water or the QV is much longer geometrically.  That's what I mean by scale.

Perhaps this suggests a different experimental approach.  Crank up the power, and don't worry if the mass of your apparatus won't move.  Try to detect the "turbulent" "flow" of the QV, in the wake of the EM propagator.  Whatever the turbulence might be, it will have to extend thru a piece of ordinary space-time.

1) Interesting.  Mulletron?

The superfluid vacuum theory is pretty neat. Seems kinda superfluous though.  8)
Title: Re: EM Drive Developments
Post by: Mulletron on 12/09/2014 11:23 am
Well here's what I think about testing the sail idea. So if the QV is transferring momentum to dielectric by the circumstances I described, by association energy is also being transferred to the dielectric, given that momentum carried by electromagnetic radiation equals its energy divided by the speed of light.

http://farside.ph.utexas.edu/teaching/em/lectures/node90.html
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/relmom.html#c2

I propose that there should also be anomalous heating of the dielectric, which otherwise can't be accounted for.
Title: Re: EM Drive Developments
Post by: Rodal on 12/09/2014 01:00 pm
...There is no net momentum transfer without finding a way to break that symmetry. I based that off of many things such as this: http://ned.ipac.caltech.edu/level5/March02/Sahni/Sahni5.html

..
In plain English for clarity, If you're getting blasted from all sides equally, there is no momentum transfer.

OK, please let me try to understand your point of view, by using this reference that you used to base your ideas:

1) The  reference states:


Quote from: http://ned.ipac.caltech.edu/level5/March02/Sahni/Sahni5.html
The vacuum state therefore has zero momentum and infinite energy !
(bold added for emphasis)

a) Stating that the vacuum state has infinite energy is not acceptable.  When the answer to a problem is infinities (as in this statement) it shows that there is something wrong with the analysis.

The reference addresses this in a footnote as follows:

Quote from: http://ned.ipac.caltech.edu/level5/March02/Sahni/Sahni5.html
Zero-point fluctuations are usually regularized by `normal ordering' - a rather ad hoc procedure which involves the substitution ak ak† rightarrow ak† ak in [63]. In curved space-time a single regularization is not enough to rid <Tik> of all its divergences. Three remaining `infinities' must be regularized, leading to the renormalization of additional terms in the one-loop effective Lagrangian for the gravitational field, which, in an FRW universe becomes: curlyLeff = sqrt-g [Lambdainfty + R / 16pi Ginfty + alphainfty R2 + betainfty Rij Rij]. Renormalization of the first term Lambdainfty rightarrow 0 corresponds to normal ordering. The presence of the second term R / 16pi Ginfty, led Sakharo v to postulate that the gravitational field might be `induced' by one-loop quantum effects in a curved background geometry, since one could recover the ordinary Einstein action by renormalizing the `bare' value Ginfty to its observed value: Ginfty rightarrow Gobs [173]. Thus both the cosmological constant Lambda and the gravitational constant G may be induced by quantum effects. The remaining two terms in curlyLeff give rise to vacuum polarization effects and have been extensively discussed in the literature

b) This reference does state that the vacuum state has zero momentum.  Please show me where does it state that "There is no net momentum transfer without finding a way to break that symmetry." or where does this reference state words to the effect that it is possible to break the symmetry of the vacuum state to transfer momentum

2) Please address the following statement in the reference that you used:


Quote from: http://ned.ipac.caltech.edu/level5/March02/Sahni/Sahni5.html
A central tenet of the general theory of relativity is that the gravitational force couples to all forms of energy through the Einstein equations Gik = (8piG / c4)Tik. Therefore if the vacuum has energy then it also gravitates !
(bold added for emphasis)



In order to correctly understand your thoughts, it would be helpful if you could clarify:

a) how do you address re-normalization: the issue of infinite vacuum energy

b) how do you address the issue that the vacuum energy does not gravitate

c) how do you address the issue of "breaking of symmetry" (no directional momentum of the vacuum) to result in useful propellant-less propulsion of the EM Drive by the vacuum


Thank you
Title: Re: EM Drive Developments
Post by: Mulletron on 12/09/2014 01:41 pm
...There is no net momentum transfer without finding a way to break that symmetry. I based that off of many things such as this: http://ned.ipac.caltech.edu/level5/March02/Sahni/Sahni5.html

..
In plain English for clarity, If you're getting blasted from all sides equally, there is no momentum transfer.

OK, please let me try to understand your point of view, by using this reference that you used to base your ideas:

1) The  reference states:

Quote from: http://ned.ipac.caltech.edu/level5/March02/Sahni/Sahni5.html
The vacuum state therefore has zero momentum and infinite energy !
(bold added for emphasis)

a) Stating that the vacuum state has infinite energy is not acceptable.  When the answer to a problem is infinities (as in this statement) it shows that there is something wrong with the analysis.

The reference addresses this in a footnote as follows:
That's your beef with them then.
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Zero-point fluctuations are usually regularized by `normal ordering' - a rather ad hoc procedure which involves the substitution ak ak† rightarrow ak† ak in [63]. In curved space-time a single regularization is not enough to rid <Tik> of all its divergences. Three remaining `infinities' must be regularized, leading to the renormalization of additional terms in the one-loop effective Lagrangian for the gravitational field, which, in an FRW universe becomes: curlyLeff = sqrt-g [Lambdainfty + R / 16pi Ginfty + alphainfty R2 + betainfty Rij Rij]. Renormalization of the first term Lambdainfty rightarrow 0 corresponds to normal ordering. The presence of the second term R / 16pi Ginfty, led Sakharo v to postulate that the gravitational field might be `induced' by one-loop quantum effects in a curved background geometry, since one could recover the ordinary Einstein action by renormalizing the `bare' value Ginfty to its observed value: Ginfty rightarrow Gobs [173]. Thus both the cosmological constant Lambda and the gravitational constant G may be induced by quantum effects. The remaining two terms in curlyLeff give rise to vacuum polarization effects and have been extensively discussed in the literature
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b) This reference does state that the vacuum state has zero momentum.  Please show me where does it state that "There is no net momentum transfer without finding a way to break that symmetry." or where does this reference state words to the effect that it is possible to break the symmetry of the vacuum state to transfer momentum

You think a link to a lesson on vacuum fluctuations is the answer to everything? The reference was an analysis of vacuum momentum. Not emdrives. The momentum transfer and symmetry breaking is from the van Tiggelen papers. The other asymmetry is/are the cavity shapes and placement of the dielectric.
In bold here: http://forum.nasaspaceflight.com/index.php?topic=29276.msg1298712#msg1298712
My entire reading list is on the google drive in the bookmarks doc.

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2) Please address the following statement in the reference that you used:

Quote from: http://ned.ipac.caltech.edu/level5/March02/Sahni/Sahni5.html
A central tenet of the general theory of relativity is that the gravitational force couples to all forms of energy through the Einstein equations Gik = (8piG / c4)Tik. Therefore if the vacuum has energy then it also gravitates !
(bold added for emphasis)

Just one of many, this one is easy because you just have to watch and listen, no reading required.
https://www.youtube.com/watch?v=JHc71K1sfSs

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It would be helpful if you would clarify:

a) how do you address normalization: the infinite vacuum energy

b) how do you address the issue of vacuum energy gravitating

c) how do you address the issue of "breaking of symmetry" (no directional momentum of the vacuum) to result in useful propellant-less propulsion of the EM Drive by the vacuum
I'm not on here to solve the cosmological constant problem. But here's some info:
a) This is an open question in physics called the vacuum catastrophe. There is research out there that suggests this can be solved:
http://arxiv.org/abs/astro-ph/0605418
http://arxiv.org/abs/astro-ph/0703364

b) Gravitation doesn't necessarily only have to be negative. See the video above again.
Interesting perspective:
https://www.astrosociety.org/publications/a-universe-from-nothing/
http://en.wikipedia.org/wiki/Zero-energy_universe (I think this article is a little off though)

c) Here's my take on the van Tiggelen papers. The PT symmetry breaking is only half of the puzzle. This just enables the momentum transfer to happen, and as they note it is a very very small acceleration velocity. What was it like 50nanometers per second IIRC? Small. The rest of the puzzle is the uneven radiation pressure across the dielectric, as seen inside the Shaywer device, as well as Cannae.

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Thank you.
Thank you. Hope I answered your questions.
So there are unsolved physics. I'm not here to solve them. Just emdrives.
Bonus material:
http://phys.org/news/2011-08-dark-illusion-quantum-vacuum.html
http://phys.org/news/2012-01-repulsive-gravity-alternative-dark-energy_1.html
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/09/2014 02:03 pm
Ron, it is as simple as this, M-E isn't the only game in town.

Actually, it is.  I have already explained this to you.  The criteria chosen by Millis, who is an engineer with no training in philosophy of science, bears no resemblance to what makes good science.  Millis was a bit of a creative genius when it came to precising what we need to hunt for.  Probably the best example of this was in formulating the term "Spacedrive" and noting we need to get past propellant if we're to move out into space.  However, the criteria developed by Millis bears no resemblance at all to what makes real science, and those portions of both the BPP project, and his AIAA book with Davis, are horrible prostitutions of the truth.  If you want to judge these various theories and models according to the dictates of science, then there are only 2 criteria: are they rational and consistent to what we already know?, and what's the physical evidence?  Science is the marriage of reason and observation and all science comes down to these two criteria eventually.  Imagining that our propulsion needs will be met by a scheme that violates EEP, GR and conservation is fundamentally irrational, and investing in a scheme with no trustworthy observations despite repeated funding flies in the face of what empirical investigation is all about.

This is not to say there are no other concerns.  For example one might prioritize by noting the import of a model as regards its utility.  Of course here M-E stands alone as well, because only M-E is telling us how to generate negative mass and thus offer a way for warp and wormhole technology.  The point though is, that if you are RATIONAL you need logically consistent theory (both internally and externally), and if you're empirical you then add the "show me" attitude of observation.  All these other models and theories FAIL when judged by these two criteria, and it is the fact folks like Millis and you, cannot prioritize their investigations based upon what makes good science, that has us in the mess we're in.

You need to stop treating science investigations as if they were part of some superstition or religion.  You're practicing scientism, not science.  You might just as well be seeking to understand rainbow colored unicorns.  You have no more warrant for belief in QVF than you do for unicorns and yet you keep going out of your way to argue for them.  I don't give a bloody damn about your unicorns.  There are no reasons to suspect unicorns exist, and there have been no credible sightings of unicorns.  You do not have a right to take taxpayer funds and search for unicorns.  The same is true of QVF, but it is not true of M-E. 
Title: Re: EM Drive Developments
Post by: Rodal on 12/09/2014 02:40 pm
....
The momentum transfer and symmetry breaking is from the van Tiggelen papers. The other asymmetry is/are the cavity shapes and placement of the dielectric.

... Here's my take on the van Tiggelen papers. The PT symmetry breaking is only half of the puzzle. This just enables the momentum transfer to happen,
...
(bold added for emphasis)

In order to correctly interpret how you are proposing that the EM Drive acts as a "sail" getting momentum "push" from the Quantum Vacuum,

Could you please provide a link to the specific papers that you refer (above) as "the van Tiggelen papers"  ?

Title: Re: EM Drive Developments
Post by: Mulletron on 12/09/2014 03:33 pm
....
The momentum transfer and symmetry breaking is from the van Tiggelen papers. The other asymmetry is/are the cavity shapes and placement of the dielectric.

... Here's my take on the van Tiggelen papers. The PT symmetry breaking is only half of the puzzle. This just enables the momentum transfer to happen, and as they note it is a very very small acceleration. What was it like 50nanometers per second IIRC? Small. The rest of the puzzle is the uneven radiation pressure across the dielectric, as seen inside the Shaywer device, as well as Cannae.
...
(bold added for emphasis)
Could you please provide a link to the specific papers that you refer (above) as "the van Tiggelen papers"  ?
You don't remember? That you have commented on even?
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1269074#msg1269074
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.96.130402
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.100.248902
http://arxiv-web3.library.cornell.edu/find/quant-ph/1/au:+Tiggelen_B/0/1/0/all/0/1
http://arxiv-web3.library.cornell.edu/find/quant-ph/1/au:+Rikken_G/0/1/0/all/0/1
http://arxiv-web3.library.cornell.edu/find/quant-ph/1/au:+Donaire_M/0/1/0/all/0/1
http://arxiv-web3.library.cornell.edu/abs/1404.5990
http://qvg2013.sciencesconf.org/conference/qvg2013/program/Donaire_qvg2013.pdf
http://www.iesc-proceedings.org/articles/iesc/pdf/2012/01/iesc_qed2012_02004.pdf
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.230402
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.230402
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.111.143602
http://cmp.physics.iastate.edu/wavepro/program/presentations/Tiggelen.pdf

Bonus material:
http://academiccommons.columbia.edu/catalog/ac%3A177593
http://lpm2c.grenoble.cnrs.fr/spip.php?page=publications&id_auteur=18&clepubli=van%20Tiggelen&lang=fr

This is the one that refutes Dr. White, but the references are useful. It was refreshing to see the author slinging around the same names I have been, which shows I haven't been off on a tangent the whole time.
http://arxiv.org/pdf/1411.5359v1.pdf

Quote
No, that is not an acceleration.  That (50nanometers per second) is a velocity.
I knew you were going to use that as a cheap shot  >:( because I forgot to type it fully out. Why do you think I said IIRC? Typical.....anyway that was from the 2003 Feigel paper, which they cited, built upon and refined. And yes going back to the reference, it was velocity.


Title: Re: EM Drive Developments
Post by: RotoSequence on 12/09/2014 04:03 pm
Ron, it is as simple as this, M-E isn't the only game in town.

Actually, it is..... 

With no end to upstart theories, not even Einstein's seminal works on relativity can say they're the only game in town. Woodward's work is nowhere near the prestige, acceptance, or levels of proof enjoyed by Einstein, and should not be treated as such without a lot of (as yet forthcoming) experimental proof.

Woodward's ideas are very interesting, and I would like to know more, but I'm looking for experimental proof (or refutation); reading the book can't give me that.
Title: Re: EM Drive Developments
Post by: Rodal on 12/09/2014 04:28 pm
and as they note it is a very very small acceleration. What was it like 50nanometers per second IIRC? Small.

No, that is not an acceleration.  That (50nanometers per second) is a velocity.  By itself it provides no information what is the acceleration unless one knows the time interval over which it takes place (strictly speaking one needs the velocity function as a function of time)

To know what is the acceleration we need to know what is the time interval over which the velocity gets changed.   

If the time interval over which the velocity gets changed is infinitesimally small, this acceleration can approach infinity (or if the time interval is large enough the acceleration can approach zero).  Have you seen an acceleration figure from van Tiggelen or the time interval over which this change in velocity takes place?

(Admittedly, the time interval would have to be very small: nanoseconds, for this velocity to entail a large acceleration. To justify the accelerations measured at NASA Eagleworks, the time interval would have to be milliseconds)

See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1294901#msg1294901

NASA Eagleworks measured acceleration =  6 * 10^(-6) m/sec^2

velocity change = 50* 10^(-9) m/sec

implied time interval = ( 50* 10^(-9) m/sec ) / ( 6 * 10^(-6) m/sec^2) = 8 milliseconds

Also, is the velocity change universal irrespective of the dielectric material, geometry, and mass of the spacecraft? What assumptions is this velocity figure (50nanometers per second) predicated on?
Title: Re: EM Drive Developments
Post by: Mulletron on 12/09/2014 04:36 pm
and as they note it is a very very small acceleration. What was it like 50nanometers per second IIRC? Small.

No, that is not an acceleration.  That (50nanometers per second) is a velocity.  By itself it provides no information what is the acceleration unless one knows the time interval over which it takes place (strictly speaking one needs the velocity function as a function of time)

To know what is the acceleration we need to know what is the time interval over which the velocity gets changed.   

If the time interval over which the velocity gets changed is infinitesimally small, this acceleration can approach infinity (or if the time interval is large enough the acceleration can approach zero).  Have you seen an acceleration figure from van Tiggelen or the time interval over which this change in velocity takes place?

(Admittedly, the time interval would have to be very small: nanoseconds, for this velocity to entail a large acceleration. To justify the accelerations measured at NASA Eagleworks, the time interval would have to be milliseconds)

See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1294901#msg1294901

NASA Eagleworks measured acceleration =  6 * 10^(-6) m/sec^2

velocity change = 50* 10^(-9) m/sec

implied time interval = ( 50* 10^(-9) m/sec ) / ( 6 * 10^(-6) m/sec^2) = 8 milliseconds

Also, is the velocity change universal irrespective of the dielectric material, geometry, and mass of the spacecraft? What assumptions is this velocity figure (50nanometers per second) predicated on?

Stop picking a strawman off a pithy mistake in wording. I corrected it. Everyone here can see you're misbehaving. The comparison you're trying to make is a false comparison. If you read the Feigel paper http://arxiv.org/abs/physics/0304100 it was about the  contribution of vacuum fluctuations to the motion of dielectric liquids in crossed electric and magnetic fields. Velocities about 50nm/s can be expected due to the contribution of high frequency vacuum modes. NOT WHOLE EMDRIVES.
Title: Re: EM Drive Developments
Post by: Rodal on 12/09/2014 04:42 pm
and as they note it is a very very small acceleration. What was it like 50nanometers per second IIRC? Small.

No, that is not an acceleration.  That (50nanometers per second) is a velocity.  By itself it provides no information what is the acceleration unless one knows the time interval over which it takes place (strictly speaking one needs the velocity function as a function of time)

To know what is the acceleration we need to know what is the time interval over which the velocity gets changed.   

If the time interval over which the velocity gets changed is infinitesimally small, this acceleration can approach infinity (or if the time interval is large enough the acceleration can approach zero).  Have you seen an acceleration figure from van Tiggelen or the time interval over which this change in velocity takes place?

(Admittedly, the time interval would have to be very small: nanoseconds, for this velocity to entail a large acceleration. To justify the accelerations measured at NASA Eagleworks, the time interval would have to be milliseconds)

See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1294901#msg1294901

NASA Eagleworks measured acceleration =  6 * 10^(-6) m/sec^2

velocity change = 50* 10^(-9) m/sec

implied time interval = ( 50* 10^(-9) m/sec ) / ( 6 * 10^(-6) m/sec^2) = 8 milliseconds

Also, is the velocity change universal irrespective of the dielectric material, geometry, and mass of the spacecraft? What assumptions is this velocity figure (50nanometers per second) predicated on?

Stop picking a strawman off a pithy mistake in wording. I corrected it. Everyone here can see you're misbehaving.

Mulletron, on one hand you post that you want everybody to work with you, and yet when trying to pursue technical issues that you brought up, you become very defensive and accuse one of misbehaving.

I am genuinely interested in pursuing:

1) What is the acceleration implied by the dielectric/Quantum Vacuum/momentum transfer you propose
2) What is the time interval over which this velocity change takes place

To make sense of any theories my approach is always to calculate, to get numbers to estimate whether the theory matches experimental results.

Apparently pursuing these technical issues with your postings with you is a waste of my time.
Title: Re: EM Drive Developments
Post by: D_Dom on 12/09/2014 04:44 pm
Was just reading about another advanced propulsion game on the SpaceX threads. Ya pays your money and ya takes your chances. No shortage of games to play...
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/09/2014 04:51 pm
I'm currently swapping my only pair of working AA's between my mouse and keyboard so please forgive that my answers here are short.  93143 seems to have answered most of your questions already.

. . .so there is change in chemical bonds energy, but that does not equate to change in energy density in the bulk, this is just a different form of energy (from chemical to kinetic and reverse, millions times a second).

Energy density is a measure of the material's properties.  We're actually most interested in the power density, since it is the change in internal energy over time.  This is why Woodward chose perovskite ceramics such as BaTiO3, PZT and most recently PMN, since these have huge power densities.  From the phenomenological standpoint however, we're really talking about internal energy of the material.  It is as the internal energy changes in these materials while they are being accelerated with respect to the distant stars, that a mass fluctuation of Mach Effect will occur.

Quote
There is no net output or input flow of energy in such harmonic motion (putting aside the decay to thermal agitation). SR is not saying that one form of energy is heavier than another form in such closed system, it does say that it is the same.
  As 93143 noted, the only closed system here necessarily includes the whole universe.  When we keep this in mind we hesitate to speak of closed systems.  The gravinertial flux that results from the gravitational interaction between all the universe's parts extends beyond any system we might describe that is short of the entire universe.

Quote
Visualizing a "gravinertial flux" won't help. I guess it is backed by equations of state in Woodward's book (?). "...that this flux can be made to flow in and out of matter under specific conditions" sounds to me like it would transfer all the "gains" that could be made in terms of "push heavy pull light" from one part of a closed system to another part of the same closed system, with no net thrust overall.

This is true, but what it means is there is no net thrust on the entire universe.  The universe does however experience an increase in entropy, and global conservation of momentum as result of the increase in momentum in the thruster as it produces thrust.

Quote
Time delays seem irrelevant for transformation from chemical bonds energy to kinetic energy back and forth in a bulk, again my battery example (please comment the battery thing : right ? wrong ? irrelevant ? Why irrelevant since it's about conversion from chemical bond energies to kinetic energies in a bulk ?)

It's important to be more specific and look at capacitors being used rather than chemical batteries, since bonds are not being created and destroyed in the materials, but rather the existing bonds are being stretched like rubber bands.  They're EM springs.  I think the rest of your question here is answered both just above and by 93143.

Quote
Er, mmm, it (SR+GR) might not explain the origin of mass as deriving from more fundamental "entities", but it does speak a little bit about inertia, if anything else, from an effective point of view, that is it allows a number of predictions about how something will accelerate or not (relative to inertial frame, say, in deep flat space) given what it does with its mass_energy content (throwing some of it or not). Bernoulli, with all due respect, was not working on a fundamental (effective) theory of dynamics, unlike GR or Newtonian dynamics.

SR and GR are theories of gravity.  Einstein deliberately chose to set inertia aside and not rely upon Mach's Principle.  Had he and Mach not had their falling out, I think Einstein would have eventually come to the understanding that Dennis Sciama did, that not only are the two intertwined (just as electricity and magnetism are) but that one is the result of the other.  It's unfortunate that Einstein was put off by Mach's refusal to accept SR, since had that not occurred we might have seen fantastically more productivity from the end of Einstein's career.

Quote
I'm not asking if such mainstream scientists could tell what it is supposed to do, I'm asking if they could give a prediction of what it will do from admitted frameworks. . .
There is no way to make sense of M-E theory without admitting Mach's Principle.  If you don't start with the notion that inertia is the result of gravity, you can't have a working theory of inertia and then expect to manipulate it.  Anytime anyone tries to make sense of Woodward's work without first accepting Mach's Principle, they will necessarily come up with gibberish.  This is in fact why Woodward named the mass fluctuation a "Mach Effect", because it relies upon Mach's Principle that inertia is the result of gravity.

Quote
If such Mach theory is compatible with SR, it will predict the same thing as SR in the same situation where SR does predict.
But SR doesn't make predictions about mass fluctuations, since it is not inherently a theory of inertia.  Bernoulli's Principle concerns inertia, but it is not a theory of inertia, so it does not make inertial predictions per se.

Quote
. . .for your average engineer knowing scientists, this is still beyond belief that a well put, reproducible proof of science, below 1000k$ could remain so widely ignored. . .

There are many reasons for this.  First off, it requires a great deal of time and effort to understand what Woodward is saying and most people won't invest that time.  Out of those who will, only some will ever obtain a decent level of understanding of it.  My understanding is not nearly as good as I'd like and I've been doing this for almost a decade now, but I am not an engineer and given the proper effort, most engineers can obtain a better understanding than I have.  Note though, they are never going to understand this like a physicist will, since they don't have the proper tools for this.  There are always exceptions but these are rare.  Dr. Rodal has made it his habit to regularly surprise me in his understandings.  He could likley understand much, much more than most engineers and perhaps even some PhD physicists who already have training in GR.  But the point remains that although one would expect interest to drive understanding, this is always limited by one's skill set and the investment they're willing to make.  Just the experimental setup takes many hours to understand.  Just availing oneself to how Woodward has isolated from all the various multitude of spurious sources that can and do occur, and see that they're dealt with appropriately, takes an enormous amount of time.  And what you're left with is not "proof" in the strictest sense.  Remember that although we speak of "proof of science", what we are really talking about is disproving the alternatives to the thing we seek.  Science never proves anything.  I say this all the time and people hear it and go right along pretending the opposite.  You need to keep this in mind: science never proves anything.  Never.  Not under a single condition does science ever prove anything.  All it can do is disprove alternatives.  This is a necessary limitation to all real science.

And finally the limitation here is that of the setup.  There is no way to do this with $100k.  Just paying the proper person to do this sort of investigation costs much more than this.  If we were to build a lab, and characterize a new balance, that would take about a year.  Someone with the proper skill set to act as Principle Investigator for such a thing, such as Dr. Rodal, makes about $200-250k/year.  How then are you going to have a professional replication for $100k?  You're not.  The only reason Woodward is able to get the work done at all, is he is retired and works for free.  That is not legal once there is funding of any type.  In fact the law here in the US REQUIRES that everyone involved gets paid.  It is not legal to work for free except on your hobbies.  I'm currently trying to start a startup to do this work in the lab and my best figure at this time is it will take $3M to build the lab, the thruster and the power system.  I am trying to bring the price down, since the more we need to do this the harder it will be to raise the funding, but for a professional test, one needs to start with the professionals and they are worth their wage.  You can't do this without a PhD leading the work and all of the people with these kinds of sheepskins are worth big money.  Guys like Bruce Long and Duncan Cummins make $250k/year and I can't ask them to wrk for less, unless of course they are willing to take an equity share in the startup.  That is certainly an option.   But really engineers don't want to carry so much risk.  They want to be paid and then gain an additional piece of the equity, which is more along the lines of what we're expecting.  Investors are those who manage the most risk and obtain the largest returns if they hit paydirt.

Quote
. . .one spectacular demo would lend less credibility to the tech than spreading a reproducible design of proof of science that barely moves a dust, but does so consistently and beyond doubt. But I'm not in this business, so maybe wrong.

No, you're right.  What one really wants is reproduction at several places but reproductions cost money and in science one does not have control over what others do.  That sort of control can only be had through funding the replications and when you do this they're no longer independent in the way necessary to meet the veracity test.  So what one is left with is at best trying to meet the validation criteria without reproduction, which means you need to design a kit you can take to various other labs and have tested cheaply, in order to get validation without replication costs.  This is what we intend to do, and hopefully NASA will let us stick our kit on the various balances at the various centers, but whether they do or not, if we have a commercial grade effect, we can press forward with commercial application.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/09/2014 05:06 pm
Quote
I am genuinely interested in pursuing:

1) What is the acceleration implied by the dielectric/Quantum Vacuum/momentum transfer you propose
2) What is the time interval over which this velocity change takes place

To make sense of any theories my approach is always to calculate, to get numbers to estimate whether the theory matches experimental results.

Apparently pursuing these technical issues with your postings with you is a waste of my time.

Ok, well you have to realize that the Feigel paper, while it got the ball rolling, had some issues. We've discussed them. His work was furthered by Tiggelen, Shen and others I can't remember right now. His work was with liquids. So it is not a direct comparison. So that avenue is a no go. What is a go, is to build or simulate a model system where all the parameters are known. So answers 1) no clue. 2) no clue.
Title: Re: EM Drive Developments
Post by: frobnicat on 12/09/2014 05:26 pm
@93143 & Ron Stahl,

I read your replies with interest, points taken seriously, thank you. There are still things I would tend to say I disagree, but feel compelled first to clarify some concepts from primary sources (ahem, Woodward's book for instance). Hope you stick here for some time so we can pursue later (that might be a few weeks, sorry).

On the EM front, I also promised to follow on spurious "warm air jet" hypothesis as a possible explanation to some aspects of Eagleworks results. This is not forgotten but... delayed.
Title: Re: EM Drive Developments
Post by: Ron Stahl on 12/09/2014 05:27 pm
Ron, it is as simple as this, M-E isn't the only game in town.

Actually, it is..... 

With no end to upstart theories, not even Einstein's seminal works on relativity can say they're the only game in town. Woodward's work is nowhere near the prestige, acceptance, or levels of proof enjoyed by Einstein, and should not be treated as such without a lot of (as yet forthcoming) experimental proof.

Woodward's ideas are very interesting, and I would like to know more, but I'm looking for experimental proof (or refutation); reading the book can't give me that.

Lets be clear.  I didn't make any sweeping statements about Woodward's scheme working.  I said it is the only game in town and if your criteria for what is a working game is that of science, then it IS the only game in town.  I was paid to do this study in 2005 and the results of that survey were that only Woodward's scheme met the criteria of science, and only Woodward's work ought therefore find funding.  Lockheed Martin sent out a team of physicists from their Lightspeed facility to do the exact same study and came to exactly the same conclusion. 

If your working criteria for investment is that of what makes good science, ONLY Woodward's work meets that criteria.  Certainly QVF does not meet the criteria of science.  It is a scam based on delusions of grandeur and a willingness to contradict EEP, GR and conservation.
Title: Re: EM Drive Developments
Post by: Stormbringer on 12/09/2014 10:35 pm
i just brought Woodward's book and thus contributed a tiny amount of money to continuing research.
Title: Re: EM Drive Developments
Post by: Rodal on 12/10/2014 02:12 am
I am here.  Besides those points, don't forget about this interesting one

Quote from:  Jack
Also if phi/c^2 = 1 that contradicts the MET equation where phi is a variable.

phi = scalar potential of the gravitational field
c = speed of light in vacuum

This should be easy to address by the Woodward theory devotees here

If  phi/c^2 = 1 then

phi = c^2

which is a constant, therefore

If  phi=c^2, phi is a constant and  then all the derivatives of phi should be zero.

Woodward answers

Quote from: Woodward, p.70
You may be wondering, especially after all of the fuss about phi and c being “locally measured
invariants” in the previous chapter, how the derivatives of phi in these wave equations
can have any meaning. After all, if phi has the same value everywhere and at all times, how
can it be changing in either space or time?
The thing to keep in mind is “locally measured.” As measured by a particular observer,
c and phi have their invariant values wherever he or she is located. But everywhere else, the
values measured may be quite different from the local invariant values. And if there is any
variation, the derivatives do not vanish.

Now, does everybody understand the above paragraph?

Well, then Woodward gives an example:

Quote from: Woodward, p.71
Let’s look at a concrete example. Back around 1960, a few years after the discovery
of the Mossbauer effect (recoilless emission and absorption of gamma rays by radioactive
iron and cobalt), Pound and Rebka used the effect – which permits timing to an
accuracy of a part in 1017 s – to measure the gravitational redshift in a “tower” about
22.5 m high on Harvard’s campus. The gravitational redshift results because time runs
slower in a stronger gravitational field, so an emitter at the bottom of the tower produces
gamma rays that have a different frequency from those emitted and absorbed at the top
of the tower. Pound and Rebka measured this shift for a source at the top of the tower by
using a moving iron absorber at the bottom of the tower. The motion of the absorber
produces a Doppler frequency shift that compensates for the higher frequency of the
source at the top of the tower. From the speed of the absorber, the value of the frequency
shift can be calculated.
Since time runs slower at the bottom of the tower, the speed of light there, measured
by someone at the top of the tower, is also smaller. And since phi=c^2, the value of phi at
the bottom of the tower measured by the person at the top is also different from the local
invariant value. Obviously, the derivative of phi in the direction of the vertical in the
tower does not vanish. But if you measure the value of c, a proxy for phi, with, for
example, a cavity resonator, you will get exactly the local invariant value everywhere in
the tower. From all this you can infer that the locally measured value of phi is the same
everywhere in the tower, notwithstanding that it has a non-vanishing derivative everywhere
in the tower.




Here again the great Poincare had a general lemma

http://www.mathphysicsbook.com/mathematics/manifolds/homology-on-manifolds/the-poincare-lemma/

(http://www.mathphysicsbook.com/wp-content/uploads/2013/01/50.closed-1-form.png)

Title: Re: EM Drive Developments
Post by: IslandPlaya on 12/10/2014 04:18 am
BTW, you can look at the nite sky and see that it is anisotropic.
That's because the naked eye can't see very far... a few thousand light-years at most (yes, I know you can glimpse the Andromeda galaxy if you are lucky.)
On bigger scales (Billions of light-years) the Universe is remarkably isotropic. I can't cite any papers, but I believe this to be the case.
Title: Re: EM Drive Developments
Post by: Mulletron on 12/10/2014 05:55 am


Second that emotion.  Still, even I know the difference between velocity and acceleration, so the request for your viewpoints is still to be answered:

Quote from: Rodal
a) how do you address re-normalization: the issue of infinite vacuum energy

b) how do you address the issue that the vacuum energy does not gravitate

c) how do you address the issue of "breaking of symmetry" (no directional momentum of the vacuum) to result in useful propellant-less propulsion of the EM Drive by the vacuum

I don't care if you're wrong in an answer, that's the only way I appear to learn, BTW.  But I think they're fair questions.

Sure thing: I answered them here near the bottom (under the video):
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1300279#msg1300279

Next subject:

Quote
Quoting @Rodal:
The proponents of the quantum vacuum producing propulsion of the EM Drive as a sail should also try to falsify their theory.

Also, just to make sure it wasn't lost on the intellectual battlefield of yesterday(somewhere amongst the carnage of M-E theory and elementary school science class);  ;) I provided my answer to the "it's a sail!" falsification challenge here:
http://forum.nasaspaceflight.com/index.php?topic=29276.msg1300239#msg1300239
Title: Re: EM Drive Developments
Post by: Mulletron on 12/10/2014 07:18 am
Was just reading about another advanced propulsion game on the SpaceX threads. Ya pays your money and ya takes your chances. No shortage of games to play...

Hit us with a link please!
Title: Re: EM Drive Developments
Post by: Mulletron on 12/10/2014 08:40 am
Guys, as far as the "sail idea" goes, it is a rough idea. It is my Quantum thruster idea v3. I've provided a lot of references and commentary about what I think might be going on, but I don't have all the answers. This idea isn't even close to being fully developed or formalized. I don't have the skills required to make the math work. It isn't simple algebra. See all the references I've provided that are the key enablers to what I think is happening and you'll see, this is ground breaking stuff. None of the answers are contained in any one reference. I can't provide anything more than approximate solutions, with huge error bars because I don't have any idea what the value of vacuum energy is, or how to deal with calculating the Casimir energy of a conical frustum. I'm am aware of my limitations. I know that I have reached the limit of what I can further contribute, for now. I am not the guy who is going to make this happen. But other people out there have skills that I don't have and there are folks out there that are way smarter than me.

I approached this idea cold on or around the first week of August. There is a lot more work to do. While I'm not asserting that I am exactly right; I do think I have a more salient model than the existing "QVPT" idea out there. More importantly, my model isn't supported by any original research. Every step is cited by other people's work, and the discourse of this thread.

If you go back to page one and read forward, you'll see that this is an NSF driven effort. Many minds working together; shaping and molding ideas into a framework that actually works.

This could be what frees the lot of humanity from the confines of Mother Earth, by enabling cheap and easy spaceflight. No man is an island. We all sink or swim together.
Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/10/2014 12:25 pm
Exactly !  Ps: the doppler frame seems to hint at a Casmir cavity type effect, but so far I can't match the frequency response w/ simple algebra.
Title: Re: EM Drive Developments
Post by: Rodal on 12/10/2014 12:33 pm
Exactly !  Ps: the doppler frame seems to hint at a Casmir cavity type effect, but so far I can't match the frequency response w/ simple algebra.
Aren't the NASA truncated cone and the Shawyer EM Drive dimensions too large to function as such?
Title: Re: EM Drive Developments
Post by: Rodal on 12/10/2014 12:34 pm
Ok...so if I am following Rodal's analysis correctly, Jack Sarfatti's counter to Woodward's  argument is...overly broad?  Flawed?
No, not at all.  Jack's review is not overly broad.  On the contrary, it is very specific and well defined: with equations precisely showing what he means.

I only addressed a few words, less than 1%, of his review: the following few words

Quote from:  Jack
Also if phi/c^2 = 1 that contradicts the MET equation where phi is a variable.

Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/10/2014 12:36 pm
BTW, you can look at the nite sky and see that it is anisotropic.
That's because the naked eye can't see very far... a few thousand light-years at most (yes, I know you can glimpse the Andromeda galaxy if you are lucky.)
On bigger scales (Billions of light-years) the Universe is remarkably isotropic. I can't cite any papers, but I believe this to be the case.

Remarkably isotropic turns out to be the same thing as anisotropic.  Here's a bit more beyond the nekkid eyeball...

Are'nt you supposed to calculate some Mandlebrotian dimensionality from that ???
Title: Re: EM Drive Developments
Post by: aceshigh on 12/10/2014 12:37 pm
@Mulletron: your posts making fun of Woodward Theory as something nonsensical just because he used the name Flux Capacitor to a part of his test device, are not much above the level of Ron Stahls posts


@Ron Stahl: you should breath and count to 100 before answering some stuff. While it would be wrong of us to dismiss Woodward Theory because of the way you (or even if it was Woodward himself) bashes as wackos anyone with different opinions from you, because we should pay attention to the science, not to your expletives and ad hominens, you should also focus on science and avoid all those ad hominens and attacks on other people. There are nicer ways to say you disagree with someone than to say the person is a wacko, or that they are all wrong, etc.
Title: Re: EM Drive Developments
Post by: aceshigh on 12/10/2014 12:39 pm
Ok...so if I am following Rodal's analysis correctly, Jack Sarfatti's counter to Woodward's  argument is...overly broad?  Flawed?
No, not at all.  Jack's review is not overly broad.  On the contrary, it is very specific and well defined: with equations precisely showing what he means.

I only addressed a few words, less than 1%, of his review: the following few words

what about the other 99%? Is Jack correct?
Title: Re: EM Drive Developments
Post by: Notsosureofit on 12/10/2014 12:41 pm
Exactly !  Ps: the doppler frame seems to hint at a Casmir cavity type effect, but so far I can't match the frequency response w/ simple algebra.
Aren't the NASA truncated cone and the Shawyer EM Drive dimensions too large to function as such?

Maybe, but I don't see why.  The doppler response (two photon) seems to be the key characteristic.  (although I have to look in a different, ie doppler, AFR to "see" it.  I'm still missing something, before I can make a complete thought on this .  I was surprised to see the numbers come out even close for such a simple argument.
Title: Re: EM Drive Developments
Post by: Rodal on 12/10/2014 01:38 pm
Ok...so if I am following Rodal's analysis correctly, Jack Sarfatti's counter to Woodward's  argument is...overly broad?  Flawed?
No, not at all.  Jack's review is not overly broad.  On the contrary, it is very specific and well defined: with equations precisely showing what he means.

I only addressed a few words, less than 1%, of his review: the following few words

what about the other 99%? Is Jack correct?

Piano piano si va lontano

Others in the forum can address the other 99%.  Personally, before addressing any of the other 99%, I would like Mulletron's opinion regarding Woodward's statement

(this was recently addressed by none other than Fornaro here:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1300761#msg1300761  )

Quote from: Woodward p.70
The thing to keep in mind is “locally measured.” As measured by a particular observer,
c and phi have their invariant values wherever he or she is located. But everywhere else, the
values measured may be quite different from the local invariant values.

where Woodward states that the speed of light is only invariant to a local observer but "everywhere else, the values measured may be quite different from the local invariant values" as we have been arguing this before with Mulletron, regarding the speed of light in a dielectric (or water, for that matter) as compared to the speed of light in vacuum.    I understand Mulletron's argument that between the particles in any media there is a vacuum, but to make calculations one has to resort to field equations, (as done by Woodward) and then it is more expedient to adopt this viewpoint.

However, for Woodward's formulation in particular this fine point becomes all the finer, as the Woodward Mach Effect depends on these derivatives !

Hence, there is an insufficiently unexplored (from a theoretical and experimental viewpoint) problem here: as Woodward is using relativity field equations involving (time and space) derivatives in materials: I think its validity really, really requires experimental verification.  Particularly when the Abraham/Minkowski paradox is unresolved. 

Others may disagree with Woodward using relativity field equations for this, but I think he is (at least) consistent in this particular issue ( I have not explored the other 99%) .
Title: Re: EM Drive Developments Thread
Post by: Chris Bergin on 12/12/2014 11:37 am
Thread back on after at least a trim of bad posts over the last 10 pages or so. I honestly couldn't read back further than that without my brain turning to mush.

Pointless posts (including one post that was basically "LOL") removed. Personal attack posts removed - member removed. Stupid posts removed - member asked not to post on here again.

However, nothing that I read (at least over the pages I looked at) feels like this site's subject matter, so I'm locking it (but putting it back on view) and we'll start a new thread in an attempt to make it relevant to this site. That's the best solution, better than leaving this in moderation.

Thread 2:
http://forum.nasaspaceflight.com/index.php?topic=36313.0