Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2138212 times)

Offline Rodal

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Quote
This finding indicates that the photons all moved at the same speed, even though different photons had different energies. This is one of the best measurements ever of the independence of the speed of light from the energy of the light particles.
Beyond confirming the general theory of relativity, the observation rules out one of the interesting ideas concerning the unification of general relativity and quantum theory. While these two theories are the pillars of physics today, they are still inconsistent, and there is an intrinsic contradiction between the two that is partially based on Heisenberg's uncertainty principle that is at the heart of quantum theory.
One of the attempts to reconcile the two theories is the idea of "space-time foam." According to this concept, on a microscopic scale space is not continuous, and instead it has a foam-like structure. The size of these foam elements is so tiny that it is difficult to imagine and is at present impossible to measure directly. However light particles that are traveling within this foam will be affected by the foamy structure, and this will cause them to propagate at slightly different speeds depending on their energy.
Yet this experiment shows otherwise. The fact that all the photons with different energies arrived with no time delay relative to each other indicates that such a foamy structure, if it exists at all, has a much smaller size than previously expected.



http://phys.org/news/2015-03-einstein-scientists-spacetime-foam.html?utm_source=nwletter&utm_medium=email&utm_content=ctgr-item&utm_campaign=daily-nwletter


These conclusions involve dispersion (variation of speed with frequency) for those wavelengths comparable to the characteristic length of the assumed foam structure of space-time.
« Last Edit: 03/23/2015 12:22 PM by Rodal »

Offline tchernik

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Whatever, I second Dr Rodal: despite using advanced concepts, with only electricity and no fuel on board, and having an unusual odd shape, those conceptual flying saucers are not propellantless thrusters, since they have to accelerate ambient air for propulsion. This is leading-edge, but still classical physics.

Yep. And I think a great deal of effort in this thread and the previous defunct one, has been going precisely into determining if this was (or not) yet another instance of the Biefeld-Brown effect (ionic wind) or due to spurious thermal effects/convection, easily mistaken with thrust at such low acceleration regime.

That last point is still unclear, if I'm reading the discussion correctly, but some bits of evidence seem to hint it is not another instance of those known-to-be-fake "reactionless" thrusters from the past.

Offline Rodal

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....
The copper frustum thrust reversal due to only its dielectric placement came when I was experimenting with the TM010 mode,...
Paul,

Thanks so much for the very clear and complete response.

Concerning the designation of mode TM010 for this mode shape, please allow me to make this note, not because of nitpicking but perhaps to come to a common understanding (where for example I could be shown to be wrong, in which case I would appreciate learning about something I may have missed or misinterpreted).

I think this mode has been innocently mislabeled, in the efforts by the COMSOL FEA analyst to designate modes on the basis of vector field plots (for FEA analysis the mode shape numbers have to be designated by the analyst while in an exact solution the mode shape numbers come automatically from the solution: there is no room for interpretation).  I think that this mode shape correct designation is TM011 instead of TM010 because:

1) There can be no TMmn0 modes for a truncated cone.  TMmn0 modes need to have a constant electromagnetic field in the longitudinal direction of the cavity.  This is possible for a cylindrical cavity (containing no other dielectrics inside besides the cavity medium) because it has constant geometrical and material properties in the longitudinal direction.  But a conical cavity has variable cross-section in the longitudinal direction, therefore the  TMnn0 mode is not possible.  The first possible mode (if it is not cut-off) is TMmn1.  The exact solution for the truncated cone shows this.  See for example:  http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html   :The quantum mode number "p" for a truncated cone is related to k.   k cannot be zero for a truncated cone, since k = ω/c for a truncated cone , therefore k = 0 implies zero frequency for a truncated cone. 

2) As the attached plot shows, COMSOL's FEA plot shows an electromagnetic field that is not constant in the longitudinal direction, therefore this is not TM010, it looks instead as TM011 upon closer inspection.

(Therefore the analyst's designation for TM011 should be changed to TM012 and so forth for TM01p modes)

« Last Edit: 03/23/2015 05:26 PM by Rodal »

Offline Mulletron

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Hey @Rodal, would you mind telling us more about what sources and methods you are using or have developed that allowed you to generate these original and colorful simulations in these posts:

http://forum.nasaspaceflight.com/index.php?topic=36313.msg1348295#msg1348295
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1340906#msg1340906
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1340909#msg1340909
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1341244#msg1341244
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1344664#msg1344664

It is quite evident that over the course of this lengthy discussion, you have developed tools and methods which can be helpful to many others. Can you give us a summary of what you can do now?
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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Hey @Rodal, would you mind telling us more about what sources and methods you are using or have developed that allowed you to generate these original and colorful simulations in these posts:

http://forum.nasaspaceflight.com/index.php?topic=36313.msg1348295#msg1348295
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1340906#msg1340906
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1340909#msg1340909
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1341244#msg1341244
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1344664#msg1344664

It is quite evident that over the course of this lengthy discussion, you have developed tools and methods which can be helpful to many others. Can you give us a summary of what you can do now?
Yes, it would be a good idea to summarize them (when I have a chance to do it  :)  )

My analysis is all based on exact solutions based on classical Electromagnetism (*), which I have discussed earlier in the thread. 

I think that @Notsosureofit may have followed some of my earlier discussions.

I wrote Mathematica code to numerically solve the eigenvalue problems in the exact solutions and to plot the solutions.

It is a work in progress: I started with contour plots for fields and later on I wrote the code for the vector plots.

Since the natural coordinates of the exact solution are in spherical coordinates attached to the cone, to plot these fields in Mathematica one has to transform the coordinates and the vectors to a Cartesian field x, y, z.  This transformation actually took more time to get just right (because of nonlinearities involving SquareRoots and ArcTan functions that have multiple values) than the time it took to get the exact solutions.

In the course of one of our latest post discussions with @Frobnicat I started by showing the vector components of E and B to make a point about Poynting's vector (no pun intended) and I told myself: hey why don't I just calculate and plot Poynting's vector ? (NASA Eagleworks did not show us COMSOL plots of Poynting's vector: don't know whether COMSOL can do this easily ...)

My next step was going to be to calculate more exact solutions (including the dielectric) but I am spending more time on these plots.  For example, depending on the discussion it may be interesting to plot Maxwell stress tensors components and/or the components of the 3+1 spacetime relativistic energy-stress tensor ...

And I'm immediately interested in examining Poynting's vector direction for a number of modes in NASA Eagleworks truncated cone to see whether there is any mode clearly pointing in the direction of the big base.  So far all the modes I have examined have a Poyinting's vector very clearly directed towards the small base and other ones have a Poynting's vector that may be zero or very small in the opposite direction.

Which means that I should also write Mathematica code to integrate Poynting's vector for the cases in which it is not visually clear which way the overall integral over the volume is pointing.

______________
(*) As discussed previously, for example the electromagnetic force depends on the derivative of Poynting's vector with respect to time and on the divergence of Maxwell's stress tensor.  Poynting's vector goes like (Cos[ωt])^2 so its derivative with respect to time (2 Cos[ωt]*Sin[ωt] = Sin[2ωt]) should average zero over each half cycle Pi/ω = 1/(2 f).  The divergence of Maxwell's stress tensor should be zero if there are no electromagnetic sources inside the cavity.  (Notice that Brandenburg assumes sources inside the cavity to arrive at his explanation).
« Last Edit: 03/23/2015 07:03 PM by Rodal »

Online Flyby

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If I'm understanding this right is there a kind of catch 22 at work here. To validate if this drive works or not you need a greater power input, but to obtain access to a greater power input it has to be proved that it works first?

I fear it is worse then that, because when you resort to more power input the thermal effects on the frustrum will also increase, with a dramatic negative effect on the Q.
And according to Shawyer, there is a real relation between a high Q and the force the "effect" produces.

That is exactly why Shawyer's latest experiment is aiming for a liquid nitrogen cooled device.
Needless to say it increases the cost price considerably.... ::)
The practical challenge to keep such a thruster operational is how to keep the Q  (and the frequency) constant, regardless of the temperature increase...

As Dr.Rodal already suggested, Shawyer has a considerably lead in experimental results, considering he already opted for a more efficient spherical truncated cone and supercooled surfaces. The home build devices we've seen so far is where Shawyer was in 2003....
Luckily, we can learn from his try and error experiments to have a fast forward in concepts...

I think the cheapest alternative would be a medium powered device that has water cooling. I was thinking along a thermal past embedded tubular copper pipe around the cone, using water cooling systems used for PC overclocking. those are easy and readily available online..
Sadly, I do not have the means to start such an undertaking, neither technically, nor financially..

As said before,  way too much energy is spend trying to separate and validate an actual thrust signal from potential background noise.... A brute force approach is needed just to identify whether or not it is working.

If, just like the Chinese, some one succeeds in yanking 720mN out of it (72g force) then all the discussions about the validity of measurements are over and you'll get enough momentum for a world wide focus on the theoretical aspect if this mysterious force...

« Last Edit: 03/23/2015 05:13 PM by Flyby »

Offline JasonAW3

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Ok, here's a crazy idea;

     Is it not possible that what is being seen with the EM drive is not so much actual thrust, although the effect detects as such, but possibly an alteration of space itself?  Perhaps compactifycation on an almost infitismal scale?

     From what I've been able to gather, it would detect as actual thrust due to movement of the test article, due to the tiny amount of actual distortion, it wouldn't even be visible optically, unless using an extremely sensitive spectrometer for light frequency shifting in the area of the device.  I realize that the power calculated to create such a distortion are several orders of magnitude greater than what is being used here, but Einstien suggested that Gravity should be able to be manipulated in a fashion similar to electromagnetism.

     Is it possible that someone has stumbled onto just such a method USING electromagnetism?  Or, it could be some form of enhancing of the Nuclear Strong or Nuclear Weak forces.  However, I suspect that manipulation of a local EM field of sufficent local intesity, could alter space within the same volume, assuming the concept of Inflation is correct.
My God!  It's full of universes!

Offline tchernik

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Ok, here's a crazy idea;

     Is it not possible that what is being seen with the EM drive is not so much actual thrust, although the effect detects as such, but possibly an alteration of space itself?  Perhaps compactifycation on an almost infitismal scale?

If that's the case, then it could be a good idea to stick fully enclosed accelerometers close to the Emdrive, at several distances, for finding out if there is any residual effect in its vicinity...

Has anyone done such a thing?

Offline Stormbringer

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Ok, here's a crazy idea;

     Is it not possible that what is being seen with the EM drive is not so much actual thrust, although the effect detects as such, but possibly an alteration of space itself?  Perhaps compactifycation on an almost infitismal scale?

If that's the case, then it could be a good idea to stick fully enclosed accelerometers close to the Emdrive, at several distances, for finding out if there is any residual effect in its vicinity...

Has anyone done such a thing?

I think it might be worth doing but i see a few problems.

The current investigation at the device itself is attempting to detect micro-newton scale thrust signals. gravity effects fall of drastically at distance. so presumably any gravitic/spacetime distortion effect at distance would be all that much smaller and therefore that much harder to detect.

Dr White's other experiment is based on just such an effect and it has not risen according to publicly disclosed reports comfortably above sigma and that laser interferometry is extremely sensitive.

The current activity is under deadline pressure. I think they have until the end of the month to get a 100 micro-newton signal to justify independent replication efforts. This makes changing the protocol drastically perhaps a destructive course of action. Something does need to be done but probably on stuff like the power input or waveforms or the device itself rather than the detection protocol. Unless it can be done without delaying the work or invalidating the data.
When antigravity is outlawed only outlaws will have antigravity.

Offline Rodal

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Hey @Rodal, would you mind telling us more about what sources and methods you are using or have developed that allowed you to generate these original and colorful simulations in these posts:

http://forum.nasaspaceflight.com/index.php?topic=36313.msg1348295#msg1348295
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1340906#msg1340906
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1340909#msg1340909
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1341244#msg1341244
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1344664#msg1344664

It is quite evident that over the course of this lengthy discussion, you have developed tools and methods which can be helpful to many others. Can you give us a summary of what you can do now?
Yes, it would be a good idea to summarize them (when I have a chance to do it  :)  )

My analysis is all based on exact solutions based on classical Electromagnetism (*), which I have discussed earlier in the thread. 

I think that @Notsosureofit may have followed some of my earlier discussions.

I wrote Mathematica code to numerically solve the eigenvalue problems in the exact solutions and to plot the solutions.

It is a work in progress: I started with contour plots for fields and later on I wrote the code for the vector plots.

Since the natural coordinates of the exact solution are in spherical coordinates attached to the cone, to plot these fields in Mathematica one has to transform the coordinates and the vectors to a Cartesian field x, y, z.  This transformation actually took more time to get just right (because of nonlinearities involving SquareRoots and ArcTan functions that have multiple values) than the time it took to get the exact solutions.

In the course of one of our latest post discussions with @Frobnicat I started by showing the vector components of E and B to make a point about Poynting's vector (no pun intended) and I told myself: hey why don't I just calculate and plot Poynting's vector ? (NASA Eagleworks did not show us COMSOL plots of Poynting's vector: don't know whether COMSOL can do this easily ...)

My next step was going to be to calculate more exact solutions (including the dielectric) but I am spending more time on these plots.  For example, depending on the discussion it may be interesting to plot Maxwell stress tensors components and/or the components of the 3+1 spacetime relativistic energy-stress tensor ...

And I'm immediately interested in examining Poynting's vector direction for a number of modes in NASA Eagleworks truncated cone to see whether there is any mode clearly pointing in the direction of the big base.  So far all the modes I have examined have a Poyinting's vector very clearly directed towards the small base and other ones have a Poynting's vector that may be zero or very small in the opposite direction.

Which means that I should also write Mathematica code to integrate Poynting's vector for the cases in which it is not visually clear which way the overall integral over the volume is pointing.

______________
(*) As discussed previously, for example the electromagnetic force depends on the derivative of Poynting's vector with respect to time and on the divergence of Maxwell's stress tensor.  Poynting's vector goes like (Cos[omega*t])^2 so its derivative with respect to time (2 Cos[omega*t]*Sin[omega*t]) should average zero over each half 2Pi/omega cycle.  The divergence of Maxwell's stress tensor should be zero if there are no electromagnetic sources inside the cavity.  (Notice that Brandenburg assumes sources inside the cavity to arrive at his explanation).
I just made some minor improvements to the he Poynting vector plotting code and thereby updated the images shown on http://forum.nasaspaceflight.com/index.php?topic=36313.msg1348295#msg1348295

Offline JasonAW3

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Ok, here's a crazy idea;

     Is it not possible that what is being seen with the EM drive is not so much actual thrust, although the effect detects as such, but possibly an alteration of space itself?  Perhaps compactifycation on an almost infitismal scale?

If that's the case, then it could be a good idea to stick fully enclosed accelerometers close to the Emdrive, at several distances, for finding out if there is any residual effect in its vicinity...

Has anyone done such a thing?

I think it might be worth doing but i see a few problems.

The current investigation at the device itself is attempting to detect micro-newton scale thrust signals. gravity effects fall of drastically at distance. so presumably any gravitic/spacetime distortion effect at distance would be all that much smaller and therefore that much harder to detect.

Dr White's other experiment is based on just such an effect and it has not risen according to publicly disclosed reports comfortably above sigma and that laser interferometry is extremely sensitive.

The current activity is under deadline pressure. I think they have until the end of the month to get a 100 micro-newton signal to justify independent replication efforts. This makes changing the protocol drastically perhaps a destructive course of action. Something does need to be done but probably on stuff like the power input or waveforms or the device itself rather than the detection protocol. Unless it can be done without delaying the work or invalidating the data.

However, if the effect is not gravitic in nature but simply a distortion of space, gravity itself may not be involved but the electromagnetic forces themselves may be causing a localized distortion of space, either compression in front or expansion in back.  again, this assumes the theory of Spacial Inflation is accurate.
My God!  It's full of universes!

Offline Stormbringer

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Ok, here's a crazy idea;

     Is it not possible that what is being seen with the EM drive is not so much actual thrust, although the effect detects as such, but possibly an alteration of space itself?  Perhaps compactifycation on an almost infitismal scale?

     From what I've been able to gather, it would detect as actual thrust due to movement of the test article, due to the tiny amount of actual distortion, it wouldn't even be visible optically, unless using an extremely sensitive spectrometer for light frequency shifting in the area of the device.  I realize that the power calculated to create such a distortion are several orders of magnitude greater than what is being used here, but Einstien suggested that Gravity should be able to be manipulated in a fashion similar to electromagnetism.

     Is it possible that someone has stumbled onto just such a method USING electromagnetism?  Or, it could be some form of enhancing of the Nuclear Strong or Nuclear Weak forces.  However, I suspect that manipulation of a local EM field of sufficent local intesity, could alter space within the same volume, assuming the concept of Inflation is correct.

Gads. Given the thread history I hesitate to even go here. If we are talking about  strong interactions and some sort of gravity connection there is something I always wanted to try -but it is straight out of Ko0k central territory. Fringe lore says that bismuth has an unusual nucleonic structure that slightly exposes normally inaccessible strong force flux lines to potential manipulation and that this would have a gravity or warping effect under the assertion that the strong force and gravity are related. If I had the money to start a kook garden shed laboratory I would buy some bismuth and try zapping it in creative ways to see if there was anything to it.  I might try to melt it and aline the structure with magnets and electricity to get the nuclei aligned with each other to perhaps amplify it's kook-alleged  properties.

At any rate if a bit of bismuth found it's way into some of the frustrum replication efforts i certainly would not mind. If nothing interesting happens no one need ever know such a thing was seriously tried. No reputations or credentials need be risked.
When antigravity is outlawed only outlaws will have antigravity.

Offline Mulletron

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If I'm understanding this right is there a kind of catch 22 at work here. To validate if this drive works or not you need a greater power input, but to obtain access to a greater power input it has to be proved that it works first?
I fear it is worse then that, because when you resort to more power input the thermal effects on the frustrum will also increase, with a dramatic negative effect on the Q.

Yes I believe there is enormous value in doing low power experiments.
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1331993#msg1331993

As power is increased, so too are thermal effects. I think the disconnect here with the LDS at Nasa is that the vacuum chamber and LDS setup is a "complex system" with many (hidden) variables (convection, unbalanced arm, thermal expansion....). Many of these variables have been sussed out in this thread and the previous one.

I firmly believe that low power is the way to go for now, in order to tease out a subtle effect * (which has the potential to be studied and optimized if conclusively verified) which, under high power experiments will get overwhelmed by heat.

I've taken my own advice, and taken a gamble on using low power and using what I've learned from Cavendish (http://en.wikipedia.org/wiki/Cavendish_experiment), hopefully I can build a sensitive (and simple enough) balance. Honestly for the sake of not screwing this up (for others), I prefer to keep hubris at bay and admit to what I know and what I don't know. So yes, apart from the RF stuff I'm doing (which is my day job) the balance and force measurements is uncharted territory for me.

As they say, "No man is an island" ** and I want this to be a NSF effort (and I want others to build too dangit!) because until these copper kettles go bang or bust, there is a huge QUESTION which must be answered.

Gentlemen, we will get our answer to these questions one of these days.


*5th force? or unification of EM and Gravitation? http://en.wikipedia.org/wiki/Fundamental_interaction
I'm a dreamer, I know......
**What I would give to have selfless professionals (who have open minds) donate some time and effort to this problem. Seriously.
Challenge your preconceptions, or they will challenge you. - Velik

Offline Stormbringer

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However, if the effect is not gravitic in nature but simply a distortion of space, gravity itself may not be involved but the electromagnetic forces themselves may be causing a localized distortion of space, either compression in front or expansion in back.  again, this assumes the theory of Spacial Inflation is accurate.

I am no expert but I think there is no way that any distortion of space time is anything but gravitic due to the EEP. The equivalence principle states that accelerations are indistinguishable from accelerations due to gravity. Einstein says gravity is distorted space/time. Anything that distorts space is a gravity drive. That's my understanding of it.
« Last Edit: 03/23/2015 07:25 PM by Stormbringer »
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Offline ThinkerX

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For my part, the thought that keeps crossing what's left of my mind is this device may be employing some sort of 'bouncing photon effect' - but that leads directly to a head-on collision with conservation of energy, which means that can't be the case, and yet the presence of photon's, bouncing or otherwise inside the frustum is one of the few things we do know for certain about this device.   I dunno...is there some sort of exotic loophole in the laws of thermodynamics this device could be taking advantage of? 

Offline dustinthewind

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I've taken my own advice, and taken a gamble on using low power and using what I've learned from Cavendish (http://en.wikipedia.org/wiki/Cavendish_experiment), hopefully I can build a sensitive (and simple enough) balance.


I was thinking earlier if you all might have designed a flexible beam and have a mirror mounted on the engine.  You could then use interferometry to get very accurate changes in position when the beam flexes if there is a force acting on it.  There might need to be a lot of dampening to reduce noise from vibrations though. 


Another thought hit me regarding why this drive would make a force.  It strikes me as similar to the idea in the thread "E/M propellant-less propulsion using delayed information/dielectrics (patent)" in that there may be some time delay of information going on inside the cavity plates.  It appears there are circulating currents in the device due the changing magnetic fields.  However, that information doesn't travel instantaneously.  Maybe what could be happening is that the circulating currents in the bottom plate observe the circulating current in the top plate as circulating in the same direction and so they are attracted to the top plate.  However, the top plate may observe the bottom plate having current circulating in the opposite direction and so it is repelled from the bottom plate.  The result is a unidirectional force.  In other words the currents in the top and bottom plates are about 90 degrees out of phase? 

I don't know if the delay in propulsion fits with that but maybe it takes a bit for the cavity to reach its final resonant state and then a while for the radiation to die away inside. 

If not the top plate interacting with the bottom plate then maybe the top plate interacting some distance down the side walls such that the magnetic fields are 90 degrees out of phase in time. 
« Last Edit: 03/24/2015 09:53 AM by dustinthewind »

Offline Left Field

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I've taken my own advice, and taken a gamble on using low power and using what I've learned from Cavendish (http://en.wikipedia.org/wiki/Cavendish_experiment), hopefully I can build a sensitive (and simple enough) balance.


I was thinking earlier if you all might have designed a flexible beam and have a mirror mounted on the engine.  You could then use interferometry to get very accurate changes in position when the beam flexes if there is a force acting on it.  There might need to be a lot of dampening to reduce noise from vibrations though. 


Another thought hit me regarding why this drive would make a force.  It strikes me as similar to the idea in the thread "E/M propellant-less propulsion using delayed information/dielectrics (patent)" in that there may be some time delay of information going on inside the cavity plates.  It appears there are circulating currents in the device due the changing magnetic fields.  However, that information doesn't travel instantaneously.  Maybe what could be happening is that the circulating currents in the bottom plate observe the circulating current in the top plate as circulating in the same direction and so they are attracted to the top plate.  However, the top plate may observe the bottom plate having current circulating in the opposite direction and so it is repelled from the bottom plate.  The result is a unidirectional force.  In other words the currents in the top and bottom plates are about 90 degrees out of phase? 

I don't know if the delay in propulsion fits with that but maybe it takes a bit for the cavity to reach its final resonant state and then a while for the radiation to die away inside. 

If not the top plate interacting with the bottom plate then maybe the top plate interacting some distance down the side walls such that the magnetic fields are 90 degrees out of phase in time.

Hi dustinthewind. Just so you know, I did link to your thread from here on the 28th Feb as I thought it could be relevant or spark an idea.

@aero

Is there any way the community here can help by donating some computer time to run different simulation scenarios? Can they be packaged up so that an inexperienced user can just run them and then email/post the results?

Offline JasonAW3

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And here's a sample of the spectrum analyzer test. All this test involves is injecting a calibrated 0dbm input signal to the frustum, then seeing what comes out the other side on the spectrum analyzer.

*HP 83752B Sweep generator @0dbm
*Agilent E4443A spectrum analyzer
*Gigatronics 8542C power meter w/*80301A sensor
(2) 6' high quality test cables
*=Calibrated by a lab

Combine this with the VSWR data and the behavior of the unloaded frustum between 2400-2500mhz becomes apparent. The points where the VWSR is really poor is evident in the amplitude response, seen in the spectrum analyzer shots, so these two tests validate each other.

Rest is here:
https://drive.google.com/folderview?id=0B4PCfHCM1KYoUEx5dzlVTG81a2c&usp=sharing&tid=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM

Other frequencies here:
(disclaimer, my E field probe is not optimized for all these frequencies, still useful to see what other frequencies couple to the cavity with low VSWR using my 31mm probe/cavity combination)
The best peaks of other frequencies are labeled similar to the bottom screen shot.
https://drive.google.com/folderview?id=0B4PCfHCM1KYoVkRzUGNuMVBLbVk&usp=sharing&tid=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM

Has anyone considered an optical spectrum analysis?  Just a point of curiosity.  While there will be a predicitbale amount of infrared that will show up during testing, I am curious as to weather or noth the amount on either end of the device is either higher or lower than would be predicted.  If expansion or compression of Space is involved, then there should be a difference in the predicted IR, or infact ANY optical wavelengths, output on one or possibly both ends of the device.

(Added: "or infact ANY optical wavelengths," on 4/24/2015)
« Last Edit: 04/24/2015 03:20 PM by JasonAW3 »
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Offline aero

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@aero

Is there any way the community here can help by donating some computer time to run different simulation scenarios?

I don't know. The physical dimensions of the thruster models range over several orders of magnitude from the smallest dimension of interest to the overall size of the cavity. That makes it almost a supercomputer problem. I could do better work with a faster computer but that computer runs $2500 USD and I'm sure there are a lot of members here who would like to have a new computer. And that faster computer would only allow me to set-up problems at low resolution which should be verified on a supercomputer.
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Can they be packaged up so that an inexperienced user can just run them and then email/post the results?

If you look here, http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial, you will see that the Meep tutorial strategy is to pose and explain example programs. That makes it pretty easy to copy/paste the examples and run them. The trick is understanding what you have when you are finished and the online support for questions about the Meep results is not very helpful.

Yes, problems could be packaged up and ran elsewhere. Figuring out what the answers mean, if anything, is the trick.
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Offline Rodal

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....
 Maybe what could be happening is that the circulating currents in the bottom plate observe the circulating current in the top plate as circulating in the same direction and so they are attracted to the top plate.  However, the top plate may observe the bottom plate having current circulating in the opposite direction and so it is repelled from the bottom plate.  The result is a unidirectional force.  In other words the currents in the top and bottom plates are about 90 degrees out of phase? 

I don't know if the delay in propulsion fits with that but maybe it takes a bit for the cavity to reach its final resonant state and then a while for the radiation to die away inside. 

If not the top plate interacting with the bottom plate then maybe the top plate interacting some distance down the side walls such that the magnetic fields are 90 degrees out of phase in time.
We can readily calculate the electromagnetic fields (and associated electromagnetic quantities) for the EM Drive.
It takes less than 3 seconds in my PC.
I attach plots for the mode currently tested by NASA Eagleworks in a partial vacuum, showing the magnetic field at the Big and Small bases and the electric field through the truncated cone.

I don't understand the (analogy ?) in the following statement:

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the circulating currents in the bottom plate observe the circulating current in the top plate as circulating in the same direction and so they are attracted to the top plate.  However, the top plate may observe the bottom plate having current circulating in the opposite direction and so it is repelled from the bottom plate.  The result is a unidirectional force. 

How are the circulating currents in the bottom plate "observing" the circulating currents in the top plate?
The magnetic fields are out of phase (see the plots below).  Why would the bottom circulating current "observe" the top one as circulating in the same direction: "in phase"?


And most important, how does this get around the conservation of momentum problem (if one considers the EM Drive as a closed system with no internal sources) ?

Assuming no internal magnetic sources (no magnetic monopoles) and no internal electric sources, the divergence of Maxwell's stress tensor is zero (due to the lack of internal sources inside the cavity).
The derivative with respect to time of Poynting's vector is zero (if the electromagnetic fields are a harmonic function of time). These conditions lead to no electromagnetic force on the center of mass, even when considering a fully general-relativistic formulation of the principle of conservation of energy-momentum (http://en.wikipedia.org/wiki/Electromagnetic_stress%E2%80%93energy_tensor#Conservation_laws ), because the divergence (in 3D+1 spacetime) of the stress–energy tensor is zero under those previously-stated conditions.

In order to have a force and acceleration of the EM Drive one needs electromagnetic sources inside the EM Drive cavity (as assumed for example in Brandenburg's equations) and/or the electromagnetic fields to be a nonlinear non-harmonic function of time.
« Last Edit: 03/24/2015 07:39 PM by Rodal »

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