Author Topic: EM Drive Developments Thread 1  (Read 764191 times)

Offline Stormbringer

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Re: EM Drive Developments
« Reply #620 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.
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Offline aceshigh

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Re: EM Drive Developments
« Reply #621 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.

Offline GoatGuy

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Re: EM Drive Developments
« Reply #622 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
« Last Edit: 09/16/2014 03:33 AM by GoatGuy »

Offline GoatGuy

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Re: EM Drive Developments
« Reply #623 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

Offline RotoSequence

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Re: EM Drive Developments
« Reply #624 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.
« Last Edit: 09/16/2014 03:57 AM by RotoSequence »

Offline Stormbringer

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Re: EM Drive Developments
« Reply #625 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.

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Online aero

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Re: EM Drive Developments
« Reply #626 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.
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Offline ChrisWilson68

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Re: EM Drive Developments
« Reply #627 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.

Offline ChrisWilson68

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Re: EM Drive Developments
« Reply #628 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.

Offline wembley

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Re: EM Drive Developments
« Reply #629 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

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...?

Offline ThinkerX

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Re: EM Drive Developments
« Reply #630 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.

Online Rodal

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Re: EM Drive Developments
« Reply #631 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-?
« Last Edit: 09/16/2014 01:00 PM by Rodal »

Offline wembley

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Re: EM Drive Developments
« Reply #632 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?


Offline JasonAW3

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Re: EM Drive Developments
« Reply #633 on: 09/16/2014 01:08 PM »
Out of curiosity,

     What sources of funding have White, et al. been using to fund this project?
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Online Rodal

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Re: EM Drive Developments
« Reply #634 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.
« Last Edit: 09/16/2014 01:38 PM by Rodal »

Offline wembley

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Re: EM Drive Developments
« Reply #635 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.

Online Rodal

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Re: EM Drive Developments
« Reply #636 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.
« Last Edit: 09/16/2014 02:30 PM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #637 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?

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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #638 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. 
« Last Edit: 09/16/2014 01:46 PM by JohnFornaro »
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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #639 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.
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