Author Topic: EM Drive Developments Thread 1  (Read 762710 times)

Online Rodal

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Re: EM Drive Developments
« Reply #3160 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
« Last Edit: 11/12/2014 09:47 PM by Rodal »

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #3161 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.

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #3162 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.

Online tchernik

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Re: EM Drive Developments
« Reply #3163 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.
« Last Edit: 11/12/2014 10:30 PM by tchernik »

Offline frobnicat

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Re: EM Drive Developments
« Reply #3164 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 ?
« Last Edit: 11/12/2014 10:57 PM by frobnicat »

Offline birchoff

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Re: EM Drive Developments
« Reply #3165 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.

Offline birchoff

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Re: EM Drive Developments
« Reply #3166 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.

Offline ThinkerX

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Re: EM Drive Developments
« Reply #3167 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.


Offline JohnFornaro

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Re: EM Drive Developments
« Reply #3168 on: 11/13/2014 01:48 PM »
Me not know what organ still.  Just call me Abby Normal.
Sometimes I just flat out don't get it.

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #3169 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.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #3170 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.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #3171 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.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #3172 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 cost only a dime.
« Last Edit: 11/13/2014 02:07 PM by JohnFornaro »
Sometimes I just flat out don't get it.

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #3173 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.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #3174 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.
Sometimes I just flat out don't get it.

Offline Mulletron

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Re: EM Drive Developments
« Reply #3175 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.
« Last Edit: 11/13/2014 06:26 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Online Rodal

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Re: EM Drive Developments
« Reply #3176 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.
« Last Edit: 11/13/2014 05:40 PM by Rodal »

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #3177 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.

Offline Mulletron

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Re: EM Drive Developments
« Reply #3178 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.
« Last Edit: 11/13/2014 05:41 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Online Rodal

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Re: EM Drive Developments
« Reply #3179 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

« Last Edit: 11/13/2014 05:49 PM by Rodal »

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