Author Topic: EM Drive Developments Thread 1  (Read 737039 times)

Offline knowles2

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Re: EM Drive Developments
« Reply #40 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.

Offline Star One

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Re: EM Drive Developments
« Reply #41 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.:)
« Last Edit: 08/01/2014 10:56 AM by Star One »

Offline ncb1397

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Re: EM Drive Developments
« Reply #42 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.

Offline ChrisWilson68

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Re: EM Drive Developments
« Reply #43 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.

Offline AlanSE

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Re: EM Drive Developments
« Reply #44 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.

Online scienceguy

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Re: EM Drive Developments
« Reply #45 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?
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Online Stormbringer

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Re: EM Drive Developments
« Reply #46 on: 08/01/2014 06:58 PM »
Since this was done in air, could it be this effect, which is real but unremarkable?



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.
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Online Stormbringer

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Re: EM Drive Developments
« Reply #47 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?
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Offline Robotbeat

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Re: EM Drive Developments
« Reply #48 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.
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Offline Star One

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Re: EM Drive Developments
« Reply #49 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.
« Last Edit: 08/01/2014 07:44 PM by Star One »

Offline Star One

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Re: EM Drive Developments
« Reply #50 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
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?
« Last Edit: 08/01/2014 08:23 PM by Star One »

Offline IslandPlaya

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Re: EM Drive Developments
« Reply #51 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
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.

Offline iamlucky13

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Re: EM Drive Developments
« Reply #52 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.

Online sghill

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Re: EM Drive Developments
« Reply #53 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.
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Offline iamlucky13

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Re: EM Drive Developments
« Reply #54 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.

Online Stormbringer

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Re: EM Drive Developments
« Reply #55 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 :)
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Online Stormbringer

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Re: EM Drive Developments
« Reply #56 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.
« Last Edit: 08/01/2014 09:19 PM by Stormbringer »
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Offline daveklingler

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Re: EM Drive Developments
« Reply #57 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." 

Offline Nathan

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Re: EM Drive Developments
« Reply #58 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.
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Online GusTurbo

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Re: EM Drive Developments
« Reply #59 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


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