Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2163339 times)

Offline sghill

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Lastly, the Eagleworks Lab's next paper on the Q-V entitled "Dynamics of the Vacuum" will be out on the NASA NTRS internet servers just any day now....

Sorry if I missed it, but did this paper get released?  If so, where?
Bring the thunder Elon!

Offline Rodal

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"Dmytry" please stop quoting me  ( https://forum.nasaspaceflight.com/index.php?topic=36313.msg1366843#msg1366843 ) , and simultaneously using "you" incorrectly:

you are apparently unable to even get rid of the "thermal drift"

What "thermal drift" am I unable to get rid of?

The first time that you used the "you" incorrectly ( https://forum.nasaspaceflight.com/index.php?topic=36313.msg1365922#msg1365922 ) you edited your post by stating that you were referring to a "generic you".

Now you insist on mixing me with others.  When posting your criticisms you should not use "you" if you are referring to somebody else.  Why do you insist on using a generic "you"?  Do you mean "you people in the EM Drive thread"? "you people in the NSF forum"? "you people interested in NASA and outer space"? "you Americans"? Who are you intentionally and falsely trying to group together as the object of your criticism by insisting on using a "generic you"?

You ("Dmytry") use only words to mount your criticisms, directed to a group by using a "generic you" without defining what group you are intending to group together.  Engineers and scientists use mathematics and analysis instead, and they support their statements by linked peer-reviewed references.
« Last Edit: 04/30/2015 03:41 PM by Rodal »

Offline marshallC

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My apologies if this has already been answered - I've looked back into the thread somewhat but may have missed it. Will the results of this next test be observable to a layman - that is, some kind of  movement or the like? If so, would it be allowable under the rules of the Eagleworks team to stream it, possibly on something as simple as a twitch.tv setup? I know I'd watch it :)

Offline Star One

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Lastly, the Eagleworks Lab's next paper on the Q-V entitled "Dynamics of the Vacuum" will be out on the NASA NTRS internet servers just any day now....

Sorry if I missed it, but did this paper get released?  If so, where?

Look up thread for one of Dr March's recent post as its linked to in that.

Offline Lampyridae

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@Marshall C

Not at these thrust levels, I'm afraid. It's like a 10kg engine producing enough energy to lift a sheet of paper.  Perhaps you could see the physical movement of a very sensitive balance but nothing as dramatic as the ion wind devices known as "lifters". First prize would indeed be a battery-powered device levitating into the conference hall.
« Last Edit: 04/30/2015 02:33 PM by Lampyridae »
SKYLON... The League of Extraordinary Gentlemen's preferred surface-to-orbit conveyance.

Offline SH

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Hello, I have been following Dr. White's publications with interest since he revived the Alcubierre concept in 2003.  I have a few comments and questions below.

--- On the EM drive for propulsion ---

(1) It has been argued that if the EM drive works, it would violate conservation of momentum and thus also conservation of energy.  This is not true.  Rather, if the EM drive is real, it means that the standard assumption that the quantum virtual plasma (QVP) is immutable would be false.

(2) Clarifying how momentum would be conserved:  Dr. White's theory is that the drive exchanges momentum with the QVP. Some people have said that this still does not conserve momentum because the virtual particles cannot disappear   after having exchanged momentum as this would violate conservation of momentum.  This is true -- if momentum is   transferred to a virtual particle, that virtual particle must transfer the momentum to a different virtual particle   before it can disappear.  Thus, the momentum of the ship would be propagated through the quantum virtual plasma as a wave until it reaches classical objects that can absorb the momentum permanently.  Think of the QVP as water being acted on by the propeller of a boat, with the exception that when the wake of the boat hits the shore it is absorbed by
  the shore instead of reflected back into the water (ie, there is no 'surf')

(3) Evidence in support of the QVP being mutable.  a) the force measurements of the EM-drive, b) the Casimir effect, c) as explained here (http://nextbigfuture.com/2015/02/more-emdrive-experiment-information.html), apparently Dr. White was able to show that the electron shell radii of all atoms up to atomic number 7 can be predicted based on the asumption that QVP is mutable.  I haven't read the details of that and would be curious to read where this is published if anyone knows.  d) A generic property of inflationary cosmology (as written about by Hawking, Alan Guth, Hartle, Turok, Pasachoff, Filippenko, Stenger, Vilenkin and others) is that the universe began from a small quantum fluctuation from the ground state, as stated by Vilenkin "small amount of energy was contained in that [initial] curvature, somewhat like the energy stored  in  a  strung  bow.   This  ostensible  violation  of  energy conservation is allowed by the Heisenberg uncertainty principle for sufficiently small time intervals.  The bubble then inflated exponentially and the universe grew by many orders of magnitude in a tiny fraction of a second".  Thus, it seems that inflationary cosmology is founded on a principle of mutable QVP as well.

(4) As discussed here (http://www.nasaspaceflight.com/2015/04/evaluating-nasas-futuristic-em-drive/), "The mainstream physics community assumes the Quantum Vacuum is indestructible and immutable because of the experimental observation that a fundamental particle like an electron (or a positron) has the same properties (e.g. mass, charge or spin), regardless of when or where the particle was created, whether now or in the early universe, through astrophysical processes or in a laboratory."  My question to Dr. White's team is, if your theory is correct and the QVP is mutable, then how would this be predicted to change the mass, charge, or spin of any classical particles that happened to be in the wake of an EMdrive thruster?

(5) Follow up question: if it would change the mass, charge, or spin of classical particles then it seems this would change the stable configuration of molecules or atoms and could result in spontaneous chemical reactions or cold fusion or fission, and these reactions could potentially be exploited to help generate power needed to run the EM drive. Thoughts?

(5.5) If the EmDrive works out, then it seems a small Throium reactor might be the ideal power source for long term missions:

-- On the EM drive as a method of warping spacetime --

(6) In "The Alcubierre Warp Drive in Higher Dimensional Spacetime", White and Davis (2006) theorized that, under the Chung-Freese model they predicted any torus of positive energy density would give rise to slight negative energy density in its core due to classical energy in 3+1 dimensions being shifted "off brain" into the unobservable higher dimensions.  They proposed an experiment to test this by constructing a charged capacitor ring.  My question: under the mass-energy equivalence, wouldn't you expect to get much more effect by using a rapidly spinning torus made of lead?

(7) If it were true that any torus of positive energy density contributes to a "boost" factor inside the torus, then it must be to an incredibly small amount, or else people would have noticed by pure chance that objects inside torus tend to move faster, and nobody has noticed this.  However, we have noticed that large heavy toruses require more fuel to propel.  Thus it seems that the theory of a positive energy density torus giving rise to a net boost in thrust must be impossible.

( 8 ) I feel like the equivalence between "boost" and "off brain bulk" in this paper was entirely speculative and unsupported by any real sound argument.

(9) In "Experimental Concepts for Generating Negative Energy in the Laboratory" Davis and Puthoff (2006) showed that negative energy density was producible in the lab using high energy lasers and other methods, and this would not require the more radical assumptions of extra dimensions in the Chung-Freese model.  Why weren't these methods explored?

(10) Supposing that you were able to engineer the required negative energy density around the craft in such a way as to produce a warp bubble.  The spacetime curvature inside might be flat, but not around the region of negative energy density, thus it seems that the warping of spacetime would necessarily obliterate any toroidal design used to hold the negative energy in place.
« Last Edit: 04/30/2015 03:14 PM by SH »

Offline Rodal

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Lastly, the Eagleworks Lab's next paper on the Q-V entitled "Dynamics of the Vacuum" will be out on the NASA NTRS internet servers just any day now....

Sorry if I missed it, but did this paper get released?  If so, where?


See:  https://forum.nasaspaceflight.com/index.php?topic=36313.msg1366622#msg1366622

This is the direct link:  http://hdl.handle.net/2060/20150006842
« Last Edit: 04/30/2015 03:33 PM by Rodal »

Offline LasJayhawk

Star-drive: is your FM deviation noise or are you modulating the signal, with a sine wave perhaps?

SH: as to number 2 try this. The QVP is the water, the frustum is the boat, and the RF signal is the oar. Right now we are just flailing away at the water and getting little thrust for the energy expended. But Star-Drive is starting to learn how to use his new oar, as he refines his technique the paddling will get easier.

Offline Notsosureofit

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I am somewhat curious as to why AM modulation would increase the drives output. Is it possible that the modulation scheme is increasing the average power output, or is something else in play.

I'm wondering what it would do with pulsed RF at a high rep rate?

That amplitude, frequency and phase modulation of the carrier wave results in greater thrust force is a prediction from Dr. White's computer code, and not yet an experimentally proven fact.  What we know in this regard is that the experimenters in the UK and China claim to have measured greater thrust force using a magnetron (for whatever reason) and that a magnetron performs amplitude, frequency and phase modulation of the carrier wave. We should exercise caution as neither the UK, nor the Chinese teams have been as forthcoming with data as NASA Eagleworks.  Those experiments (using a magnetron) remain to be replicated at NASA Eagleworks.

Concerning what a pulsed RF at a high rep rate would do, I expect that is something that Dr. White should be able to input in his code and give you an answer, but again whether such an answer from his computer code would be correct remains to be confirmed.

My understanding is that NASA Eagleworks is planning to replicate this June the experiments in the UK and China using a magnetron.


Dr. Rodal:

"That amplitude, frequency and phase modulation of the carrier wave results in greater thrust force is a prediction from Dr. White's computer code, and not yet an experimentally proven fact."

I think I may have verified today the need for large time rate of change of the resonant circuit phase changes as the RF amplifier driven 1,937.088 MHz, +/- ~25kHz sine wave oscillates back and forth through the resonance frequency of the frustum cavity.  Through a methodical tuning campaign using our triple stub Z-matching tuner and 2 feet of RG-8 coax as the main transmission line to the frustum, I marched the Smith Chart solution circle around its impedance space while checking the thrust output for each over a dozen stub tuner configurations.   Only those tuning solutions that maximized the phase change through resonance over the smallest frequency span generated the largest thrust signatures and in fact it overcame its lower Q-factors that those solutions provided.  In fact a running solution that yielded Q-factor solutions as high as 7,500 were out performed by two or even three to one in thrust output by tuning solutions that had half these peak Q-factors, but maximized the resonant phase change per kHz.  And yes, the input power was maintained at around 50W for all tests.  More data later this week as I continue this investigation.

BTW, our Eagleworks Dynamics of the Quantum Vacuum paper has finally been published on the NASA/NTRS server.  You can find it here: 

http://tinyurl.com/mw64rsn

Best, Paul M.

Yes, that is essentially "Q Multiplication".

Offline Space Ghost 1962

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I've examined his simulation/model. There are other ways to interpret the physics behind it.

Model can match results and yet the interpretation of "why" it works be completely different than described.

In particular, the equations remind me of particle accelerator(SSC) and mirror machine (fusion) simulations I've had to debug in the 70's - 80's. Found some surprises in Lorenz effects there reconciling Biot Svart.

I think there's something here, and I think his simulation partially matches it. But I've been through his explanation and it doesn't jive with particle/other physics results in recent years. For one, the Higgs would have to have a considerably different appearance than we are currently seeing.

The mathematics being used here is highly subjective to many different interpretations.

Suggest he found something else that's interesting than he think he's found.

Suggest also both the extreme enthusiasm and the extreme reductionism be avoided by advocates/pessimists.

Offline Mulletron

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I was given permission to share these communications. Mr. Shawyer also graciously attached a basic theory presentation which I put in the Google Drive to pass along.

His last communication is especially telling. Perhaps if folks can remain respectful (even if you disagree with his theory), maybe we can get him to speak publicly again.

While the jury is still out whether or not this will be useful for spaceflight (at least here in the USA), there is obviously an urgent need to give this serious academic attention.

https://drive.google.com/folderview?id=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM&usp=sharing
« Last Edit: 04/30/2015 05:45 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Space Ghost 1962

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Thank you for this. Having a lively discussion with others about this right now.

Suggest those interested annotate his "EMdrive basic theory" ppt and place it where it can be seen by others (respectfully).

Please keep in mind ensemble dynamics when considering it, like with any waveguide/magnetron/klystron and not field theory or simple E/B field evaluations - this will avoid nonsensical "challenges" thus better s/n ratio for "crowd sourced" contributions.

Please also thank the author for a simple case to focus on here.

add:
Hint - group and phase velocity are not kept separate. This confuses the presentation and allows ambiguity to creep into the discussion. Strongly suggest that the presentation delineate the difference because otherwise different groups criticizing will assert different combinations as a result, and everyone will talk by each other in an unfortunate way. Also, near field and far field effects are quite different. "There be tigers here".
« Last Edit: 04/30/2015 09:38 PM by Space Ghost 1962 »

Offline tchernik

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I empathize with Mr. Shawyer: it's not easy to carry the burden of proving something to a mostly hostile crowd. Especially on the Internet, where people feeling anonymous can be particularly vicious in their criticism.

If the Emdrive is confirmed to work, he would have all the merit for finding this phenomenon and making it repeatable enough for convincing others to do their own replications.

But it's my understanding that his theory of how the Emdrive works has been torn to shreds by several people. Probably not in front of him, but certainly online and in the media (with Greg Egan being a very proactive critic).

This is completely independent of the empiric problem of the Emdrive working (or not). The theory can be wrong and the device still work.

The same for Dr. White's QV approach. Nevertheless, if the results follow his present forecasts of a certain amount of force per certain amount of input power, that could help reinforce the idea that his theory might be onto something. And it can help reinforce  the assertion that the thrust is real and usable.
« Last Edit: 04/30/2015 06:50 PM by tchernik »

Offline Rodal

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For information, here are the links to:

Roger Shawyer's theory paper:

http://www.emdrive.com/theorypaper9-4.pdf

and

Greg Egan's analysis:

http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html

Basically, this is the issue: the solution for Maxwell's equation in a truncated cone cavity is comprised of standing waves, with the electromagnetic field displaying a harmonic motion every period.

Only travelling waves, in open cavities, display a directional flux.  Standing waves in closed cavities, do not, because for standing waves  the Poyinting vector is pointing towards the small base of the truncated cone during half a period, and it is pointing towards the opposite direction, towards the big base during the next half period of the Poynting vector frequency.

Therefore, the solution of Maxwell's equation shows that the effects are self-cancelling during a whole period in a closed cavity.

No unidirectional thrust of the EM Drive can take place based on Maxwell's equations, which are also valid in special relativity. 

If experiments shows a directional thrust, then appeal must be made to a different theoretical explanation (other than linear Maxwell's equations having a simple harmonic solution).

Concerning "microwave cavity engineering" this is a truly excellent article on microwave cavity design, from CERN, highly recommended:

http://cas.web.cern.ch/cas/Germany2009/Lectures/PDF-Web/Jensen.pdf
« Last Edit: 04/30/2015 07:23 PM by Rodal »

Offline zero123

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I know Mulletron. What I want to know is exactly how Dr White theory deals with superluminal speeds, which most physicists say leads to time-travel to the past and all the paradoxes that surface from that.


According to the video I showed from Dr Davis, superluminal speeds WITHOUT time-travel to the past are possible, if the light cone is tilted from 0 to 90 degrees only...


I think this question is related to spaceflight applications exactly because time travel IS an issue at relativistic velocities (to the future) and superluminal velocities (to the past, but not according to Dr Davis)

This question is probably more related to the spaceflight applications of a warp drive than the pure theoretical issues of how EM and Warp Drives work on quantum level, since the first is a result of spaceflight application while the second (which is being discussed in this thread) is not.

Don't forget that the ship is not really moving at relativistic speeds: space is.  Consequently, you could take a trip to Alpha Centauri in 2 days (or less with more power... who knows?), turn your ship around and observe the Earth as it was four years ago (as light has taken four years to get there - slow coach!). You could then observe Alpha Centauri as it is "now", and how people on the Earth will see it in four years.

With this type of technology,  it would be possible to predict when locally past events are going to be observable from the point of view of the Earth (or any other point that the light from such events had not yet reached). For example, a ship 1 light-day out from the Earth in the right place could witness a supernova before the Earth does and then be able to return to the Earth almost instantly and tell astronomers about the incoming light wave so that they could prepare to observe it.

Proviso: I am not an expert in time travel and I also have doubts about Dr Who.

(apologies if this is has already been discussed)

The question of whether/how warp drives can be used to form CTCs and time travel has been explored in this paper:

http://exvacuo.free.fr/div/Sciences/Dossiers/Time/A%20E%20Everett%20-%20Warp%20drive%20and%20causality%20-%20prd950914.pdf

The conclusion (as I understand it) is that yes, you can form a CTC if you use two separate bubbles. You travel from A to B in one warp bubble, then from B to C using a standard subluminal method and then from C back to A using another warp bubble. Then you can arrive back at A before you left for B.

Offline Mulletron

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And what about the experimental observation of non-reciprocity in room temperature and pressure nitrogen (largest portion of air) that was reported? That is also unbalanced momentum.
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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And what about the experimental observation of non-reciprocity in room temperature and pressure nitrogen (largest portion of air) that was reported? That is also unbalanced momentum.
From my recollection of reading your prior links, those involved nonlinear polarization, hence not addressed by linear, isotropic Maxwell's equations.  One of the papers addressed a 2nd order term and another addressed a 4th order term in a nonlinear perturbation analysis.

Clearly, a nonlinear differential equation does not have a simple harmonic solution.
« Last Edit: 04/30/2015 07:18 PM by Rodal »

Offline Mulletron

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And what about the experimental observation of non-reciprocity in room temperature and pressure nitrogen (largest portion of air) that was reported? That is also unbalanced momentum.
From my recollection of reading your prior links, those involved nonlinear polarization, hence not addressed by linear, isotropic Maxwell's equations.  One of the papers addressed a 2nd order term and another addressed a 4th order term in a nonlinear perturbation analysis.

Clearly, a nonlinear differential equation does not have a simple harmonic solution.

http://forum.nasaspaceflight.com/index.php?topic=36313.msg1361903#msg1361903

Edit: Added screenshot noting no dependence on polarization.
« Last Edit: 04/30/2015 07:44 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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And what about the experimental observation of non-reciprocity in room temperature and pressure nitrogen (largest portion of air) that was reported? That is also unbalanced momentum.
From my recollection of reading your prior links, those involved nonlinear polarization, hence not addressed by linear, isotropic Maxwell's equations.  One of the papers addressed a 2nd order term and another addressed a 4th order term in a nonlinear perturbation analysis.

Clearly, a nonlinear differential equation does not have a simple harmonic solution.

http://forum.nasaspaceflight.com/index.php?topic=36313.msg1361903#msg1361903

Yes, that also confirms what I stated: 

Quote
bilinear magneto-electric effects correspond to a coupling beyond the electric dipole approximation.

Bi-linearity is nonlinearity.  Many nonlinearities are modeled as piecewise linear, for example the elastic-plastic deformation of a solid, hysteresis in continuum mechanics, or hysteresis in magnetic materials, etc.

Also note: 

coupling beyond the electric dipole approximation

and

directional anisotropies

_____

Perturbation analyses are local (perturbation series) approximations to a nonlinearity, while piecewise-linear (bi-linear, and higher order) approximations are global approximations to a nonlinearity.

____

Concerning your focusing on "polar", yes it is an induced anisotropy.  What matters (concerning the validity of the linear isotropic Maxwell's equation) is the anisotropy (not whether it is initial anisotropy or induced anisotropy), Maxwell's isotropic equations do not take into account any induced anisotropy.

This happens also in continuous mechanics: as an imperfect analogy if you take an isotropic piece of certain metals and you stretch it to nonlinear permanent deformations, you will produce anisotropic alignment of the material, which will now have different properties in different directions.  If one wants to analyze the anisotropic deformation of a material that is initially isotropic, one cannot do it using isotropic elasticity based on just using elasticity equations with just Young's modulus and Poisson's ratio.


« Last Edit: 04/30/2015 08:02 PM by Rodal »

Offline Mulletron

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It is clear that we are operating under other than usual symmetry conditions and that Maxwell's equations as we were trained to use them do not apply.
Challenge your preconceptions, or they will challenge you. - Velik

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