Author Topic: EM Drive Developments Thread 1  (Read 722822 times)

Offline EdT

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EM Drive Developments Thread 1
« 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
« Last Edit: 12/12/2014 11:36 AM by Chris Bergin »

Online QuantumG

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Re: EM Drive Developments
« Reply #1 on: 06/27/2012 11:56 PM »
I hear North Korea is building one too.

Jeff Bezos has billions to spend on rockets and can go at whatever pace he likes! Wow! What pace is he going at? The slowest possible.

Offline docmordrid

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Re: EM Drive Developments
« Reply #2 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.
« Last Edit: 06/28/2012 12:11 AM by docmordrid »
DM

Offline JBF

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Re: EM Drive Developments
« Reply #3 on: 04/29/2013 12:45 AM »
New information up on 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.
« Last Edit: 04/29/2013 12:54 AM by JBF »
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Offline grondilu

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Re: EM Drive Developments
« Reply #4 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?



« Last Edit: 05/03/2013 10:12 PM by grondilu »
Space is pretty much literally an astronomically-high hanging fruit.

Offline Nathan

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Re: EM Drive Developments
« Reply #5 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.
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Offline IslandPlaya

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Re: EM Drive Developments
« Reply #6 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
Hope it stands up to further scrutiny. Could be a real game changer!

Offline Stormbringer

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Re: EM Drive Developments
« Reply #7 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.  :)
« Last Edit: 07/31/2014 04:59 PM by Stormbringer »
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Offline Star One

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Re: EM Drive Developments
« Reply #8 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?
« Last Edit: 07/31/2014 05:26 PM by Star One »

Online KelvinZero

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Re: EM Drive Developments
« Reply #9 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
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.  :)

Offline Dunners73

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Re: EM Drive Developments
« Reply #10 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".


Offline Star One

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Re: EM Drive Developments
« Reply #11 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?

Offline Stormbringer

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Re: EM Drive Developments
« Reply #12 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?
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Offline Dunners73

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Re: EM Drive Developments
« Reply #13 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

Offline john smith 19

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Re: EM Drive Developments
« Reply #14 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.
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Offline Star One

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Re: EM Drive Developments
« Reply #15 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?

Offline NovaSilisko

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Re: EM Drive Developments
« Reply #16 on: 07/31/2014 06:56 PM »
And so begins the flailing by the uninformed once again.

Offline Elmar Moelzer

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Re: EM Drive Developments
« Reply #17 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:
« Last Edit: 07/31/2014 07:13 PM by Elmar Moelzer »

Offline Star One

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Re: EM Drive Developments
« Reply #18 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
« Last Edit: 07/31/2014 10:00 PM by Star One »

Offline IslandPlaya

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Re: EM Drive Developments
« Reply #19 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:

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.

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