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#2500 by SeeShells on 16 May, 2016 20:36
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The miniVNA PRO is on sale for $490. Strange that normally the tiny is a little more expensive, but the PRO has more features, such as bluetooth, battery operation, more dynamic range, 1Hz vs 10Hz, 0dBm vs -6dBm. I guess you are paying for the miniaturization?
I didn't check the frequency range. Looks like the miniVNA PRO only has a range of 100KHz to 200MHz (extendable to 1.5Ghz with an add-on). Not really good for emdrive research unless you're building a HUGE emdrive. I'm going to delete my original post so no one makes the mistake of purchasing this unit.
Suggest Dave delete the one where he recommended I purchase it since it was one sale.
The miniVNA TINY has a frequency range from 1MHz to 3Ghz. Which is good for emdrive RF testing. http://miniradiosolutions.com/54-2/
It mini is the one I have and I like it.
Shell -
#2501 by SeeShells on 16 May, 2016 20:40
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Hi Phil, glad you're feeling better. I think we should probably leave the correct theory to a future date. Mr Shawyer helped and inspired many people. White, McCullough and others took a different theory direction, but we're all on the same team...an obscure and very interesting device that has tremendous ramifications if all the pieces of the puzzle align.
You had asked to quantify the effect of the power cord on the EM Drive experiments.
I'll leave the theory to the experts. You and I can build and test to whichever design(s) we like...that's part of the enjoyment. WE pick and choose, not a lab supervisor
Unfortunately such quantification depends on the nature of the anomalous force: according to classical physics the EM Drive should not self-accelerate. So according to classical physics, the power cord should only make a difference regarding experimental artifacts: Lorentz forces, thermal expansion of the power cord, stiffness of the power cord, etc.
However, we can make the following clear statements:
1) All theories of operation (Shawyer, McCulloch, NotSoSureOfIt, etc.) posit that the anomalous force is due to the photons inside the EM Drive, that experience a change in wavelength along the longitudinal direction in which the EM Drive is tapered. The theories differ as to where does the exterior energy required to satisfy conservation of energy and conservation come from.
2) Photons do not have a rest mass (which is the invariant measure of mass in Relativity) and their relativistic mass is undefined (since zero rest mass times infinite gamma (because they travel at speed c), is undefined). Therefore it is not satisfactory to discuss EM Drive anomalous force as being due to a shift in center of mass. No, what photons have, according to universal consensus is energy and momentum. Therefore any satisfactory discussion should be in terms of center of energy and center of momentum. Not center of mass.
3) Power cords introduce both energy and momentum into the EM Drive. This cannot be ignored: if the power is not on, there is no anomalous force. The anomalous force is, as shown by experiments, due to the power being on.
4) The feeding point of the energy and momentum also cannot be ignored: experiments have shown that it makes a difference whether the energy and momentum are fed in the middle of the EM Drive vs. being fed at one end or the other.
5) Therefore it is evident that the source of energy and momentum (the power cord) cannot be ignored. An experiment run with batteries in the moving platform has the center of energy and the center of momentum in the moving platform. Conversely, an experiment run with power cords with energy from a stationary supply does not have the center of energy and the center of momentum at the same place as the center of mass of the EM Drive: the center of energy and momentum may be outside the moving platform.
6) I have shown that coaxial power cables do not at all solve this issue. On the contrary coaxial cables deliver practically 100% of the electromagnetic momentum along their length. Running the coaxial cable from different directions does not make a difference, because the electromagnetic momentum gets delivered along whatever path you use. Once the coaxial cable RF momentum is fed, for example at the middle of the EM Drive, then that electromagnetic momentum and power become the photons that have increased momentum towards the big end and decreased momentum towards the small end. For these purposes (center of energy-momentum) it does not matter how you run the coaxial cable from one end to the other. What matters is whether the power source is stationary, with respect to the moving EM Drive, and where in the EM Drive is the RF energy and momentum injected.
7) Running an experiment with a power cord is therefore similar to running an experiment with a normal rocket using propellant coming from a stationary source. Such a test may be OK once one knows that rockets work, and one just wants to test their thrust, but it is unsatisfactory for a propellant-less device that is very much under question whether it can work in Space to self-accelerate.
No propellant ejection for a normal rocket = no thrust
No RF power fed into an EM Drive = no anomalous force
To conclusively show that rockets worked, Goddard conducted experiments with the propellant and everything else self-integrated in the rocket and showed lift-off in his experiments. Similarly, to conclusively show that an EM Drive, that works with photons that do not have mass, and only have energy and momentum, can work in outer space, the most conclusive test is the one where batteries and everything else are self-integrated in the moving platform, and not one where electromagnetic energy and momentum are fed from a stationary source.
An experiment with a power cord from a stationary source can perhaps show that one can create an anomalous force on a tapered resonant cavity being fed from a stationary source. It does not prove that there is an anomalous force acting on the whole integrated system (battery+EMDrive+etc.) when the energy and momentum are self-integrated together.
There is no need to beat this into verbal oblivion Dr. Rodal. I will be testing the drive both ways. It is truly the only way, as the data will prevail.
Shell
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#2502 by Rodal on 16 May, 2016 20:50
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...
Ok the aim was to:
There is no need to beat this into verbal oblivion Dr. Rodal. I will be testing the drive both ways. It is truly the only way, as the data will prevail.
Shell
1) Reformulate the thesis in a stronger way by stating it in terms of the photon momenta and energy and the fact that photons do not have mass and therefore discussing center of mass is inappropriate. (Motivated by McCulloch's most recent blog article concerning continually shifting the center of momentum as being the reason why the EM Drive may move).
2) Make an analogy with propellant rockets as when testing with propellant supplied from a stationary source vs testing (like Goddard) self-integrated rockets with the propellant on-board. (aka batteries).
3) Address your question regarding routing of the coaxial cable (conclusion: it makes no difference to this argument, only the place to inject RF makes a difference, and the location of the power source make a difference to this argument, not the routing of the coaxial cable).
These had not been addressed before.
I may indulge into further beating this "into oblivion" by making a quantitative mathematical analysis if and when I have a chance
I look forward to the results of your experiments, please let us know ! -
#2503 by FattyLumpkin on 16 May, 2016 21:44
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Traveller, is there a specific date for release of the commercial Emdrive thruster. Can you disclose what the date will be? (And do so)? FL
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#2504 by FattyLumpkin on 16 May, 2016 22:59
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I keep in touch with Adam Crowl of Icarus Interstellar. Don't know when or where the next Starship Congress is, but am hoping to give him some hard data before then. Tau Zero is but one of five such organizations and they (all five) have indeed been keeping an eye on Em, Cannae and MLF thrusters, where if ultimately "we" don't prevail, we'll be stuck with a probe 1,000 (yes that's one thousand) meters in length, weighing 45,000 tonnes WM, and generating enough neutrons to bake a cake on the other side of the planet. Am wondering if Centauri Dreams is still up. Off to check. FL
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#2505 by FattyLumpkin on 16 May, 2016 23:48
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Emdrive, Cannae and MLF thrusters have all been discussed to some extent or another over the years on Centauri Dreams (CDs) which is still up and running. CDs is part of the Tau Zero Foundation.
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#2506 by zen-in on 16 May, 2016 23:59
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FYI only -
Tau Zero Foundation website https://tauzero.aero seems to be gone. They advertise themselves as:
"Pioneering interstellar research, education, and outreach, to enable humanity to someday visit planets in other star systems."
From what I understand, they have never embraced emdrive discussions. I believe they might have started up when the NASA BPP (out of Glenn) lost its funding in the early 2000s. Not sure about any of their accomplishments or papers. Could be just a think tank. Other inputs welcomed.
Maybe Marc has left for interstellar space. Just kidding. I have read a lot of very good articles on that website so I hope they re-appear. In the meantime there is a good article about them on Discovery.
http://news.discovery.com/space/private-spaceflight/tau-zero-project-icarus.htm -
#2507 by VAXHeadroom on 17 May, 2016 00:31
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I'm friends with Marc Millis on FBFYI only -
Tau Zero Foundation website https://tauzero.aero seems to be gone. They advertise themselves as:
"Pioneering interstellar research, education, and outreach, to enable humanity to someday visit planets in other star systems."
From what I understand, they have never embraced emdrive discussions. I believe they might have started up when the NASA BPP (out of Glenn) lost its funding in the early 2000s. Not sure about any of their accomplishments or papers. Could be just a think tank. Other inputs welcomed.
Maybe Marc has left for interstellar space. Just kidding. I have read a lot of very good articles on that website so I hope they re-appear. In the meantime there is a good article about them on Discovery.
http://news.discovery.com/space/private-spaceflight/tau-zero-project-icarus.htm
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#2508 by Oakey on 17 May, 2016 00:56
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I've read Mculloughs proposal over and over. I'm still struggling. What is the crux of this position? All I can gleam out is its similar to cassimir effect of excluding wavelengths causing a difference in em pressures. Is it some how the microwaves act like the plates in a cassimir effect? But due to internal geometry the big and small end are excluding differing em wavelengths averaged? Therebye giving a differential in momentum between high and low density energy regions of frostrum?
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#2509 by meberbs on 17 May, 2016 01:23
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I've read Mculloughs proposal over and over. I'm still struggling. What is the crux of this position? All I can gleam out is its similar to cassimir effect of excluding wavelengths causing a difference in em pressures. Is it some how the microwaves act like the plates in a cassimir effect? But due to internal geometry the big and small end are excluding differing em wavelengths averaged? Therebye giving a differential in momentum between high and low density energy regions of frostrum?
From looking at his theory and reading some of the recent explanations here, I am having trouble seeing how this theory would produce a continuous force. The descriptions are comparable to a stationary train on a frictionless surface where the passengers decide to all get up and walk to the back. The train will move forward on the rails to keep the center of mass constant, but then stop when people reach the back of the train and can't go back any further.
Going back to the frustum, reaching steady state resonance would be like everyone reaching the back of the train, since then the photons at the back which are "heavier" start getting absorbed back into the walls of the cavity and everything balances out. This could produce a noticeable effect in most laboratory experiments, but be useless for space propulsion. (Still potentially new physics which would be cool)
I assume I am missing something where the Unruh waves carry away momentum to allow the drive to continuously accelerate. -
#2510 by Rodal on 17 May, 2016 01:38
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I've read Mculloughs proposal over and over. I'm still struggling. What is the crux of this position? All I can gleam out is its similar to cassimir effect of excluding wavelengths causing a difference in em pressures. Is it some how the microwaves act like the plates in a cassimir effect? But due to internal geometry the big and small end are excluding differing em wavelengths averaged? Therebye giving a differential in momentum between high and low density energy regions of frostrum?
The Unruh effect, not the Cassimir effect.
An effect that shows that the Quantum Vacuum has thermal characteristics. Basically the Unruh effect is that observers with different accelerations will experience different forces (as a result of the Quantum Vacuum) and thus will make them interpret the state of lowest energy diff erently, depending on their acceleration.
It is a very odd effect, and there seems to be no physical explanation or intuition as to why the Quantum Vacuum behaves like this and no easy way to explain it, rather than mathematically. Usually used for very large gravitational fields like near a Black Hole. Not clear why it would be present in an EM Drive. McCulloch interprets the photons as experiencing different wavelengths along the length of the EM Drive equivalent to experiencing different "accelerations" (not acceleration due to change in velocity, since they all travel at the same speed: the speed of light, but acceleration due to change in wavelength, acceleration as in change in momentum per unit mass, and the momentum changes because their wavelength changes along the tapered longitudinal direction, and he uses a "relativistic mass"=p/c = h/(c λ) instead of the rest mass which is zero for photons).
http://phys.org/news/2016-03-chinese-scientists-quantum-simulation-unruh.html -
#2511 by Rodal on 17 May, 2016 02:02
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He uses the fact that the RF injection is continuing to push passengers into the cavity, and as you say those passengers get pushed to the big end. More and more passengers keep getting pushed into the big end.I've read Mculloughs proposal over and over. I'm still struggling. What is the crux of this position? All I can gleam out is its similar to cassimir effect of excluding wavelengths causing a difference in em pressures. Is it some how the microwaves act like the plates in a cassimir effect? But due to internal geometry the big and small end are excluding differing em wavelengths averaged? Therebye giving a differential in momentum between high and low density energy regions of frostrum?
From looking at his theory and reading some of the recent explanations here, I am having trouble seeing how this theory would produce a continuous force. The descriptions are comparable to a stationary train on a frictionless surface where the passengers decide to all get up and walk to the back. The train will move forward on the rails to keep the center of mass constant, but then stop when people reach the back of the train and can't go back any further.
Going back to the frustum, reaching steady state resonance would be like everyone reaching the back of the train, since then the photons at the back which are "heavier" start getting absorbed back into the walls of the cavity and everything balances out. This could produce a noticeable effect in most laboratory experiments, but be useless for space propulsion. (Still potentially new physics which would be cool)
I assume I am missing something where the Unruh waves carry away momentum to allow the drive to continuously accelerate.
When the RF power is turned off, no more passengers keep getting pushed into the train, and the train stops when the power is off.
Is this an artifact of the fact that the passengers start at their house (the stationary power supply) and walk (through a flexible tunnel: the coax cable) into the train ?
And the fact that experimenters are only looking at the movement of the train, and completely ignoring the movement of the passengers that are walking into the train?
Could the train move if the passengers would all be on top of the train to start with, and then drop inside the train through the train's roof (using batteries)? -
#2512 by zen-in on 17 May, 2016 02:07
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Zen, is my basic info on them right, are they acting as a think tank, have they commissioned any studies to your knowledge? Scanned the 2011 article briefly but couldn't tell.FYI only -
Tau Zero Foundation website https://tauzero.aero seems to be gone. They advertise themselves as:
"Pioneering interstellar research, education, and outreach, to enable humanity to someday visit planets in other star systems."
From what I understand, they have never embraced emdrive discussions. I believe they might have started up when the NASA BPP (out of Glenn) lost its funding in the early 2000s. Not sure about any of their accomplishments or papers. Could be just a think tank. Other inputs welcomed.
Maybe Marc has left for interstellar space. Just kidding. I have read a lot of very good articles on that website so I hope they re-appear. In the meantime there is a good article about them on Discovery.
http://news.discovery.com/space/private-spaceflight/tau-zero-project-icarus.htm
I have not met Marc and have only traded emails with him. He was employed at NASA after the BPP ended. He is not listed in the NASA directory now. Your idea is right. His website is a way of keeping the dream alive. One possibility is that Marc has joined the Breakthrough Starshot program, headed by Simon P. Warden who finally was able to get himself fired from NASA and can go back to calling NASA programs "self licking ice cream cones". Just a wild guess.
http://nasawatch.com/archives/2016/04/building-earths.html -
#2513 by meberbs on 17 May, 2016 02:12
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Attached is the guide wavelength plot for my 1st build. As the EmWave momentum is directly related to the inverse of the guide wavelength (longer guide wavelength = smaller EmWave momentum), the reverse of the attached curve shows how EmWave momentum drops as the guide wavelength lengthens as it approaches the small end.
...
Per what you said here, the total momentum of photons reflecting off the small plate is smaller than the momentum of the photons reflecting off the large plate. As known from many experiments such as Cullen's, the photons reflecting off plates apply a force to the plate in the direction they were moving before hitting the plate (assuming a head on direction for simplicity). If you are confused which direction this is, bounce a ball off some movable object and look what direction the object moves, it is the same thing.
From what you just said, the force on the small plate is smaller than the force on the large plate. This means that (assuming 0 force on the sidewalls) the net force on the metal cavity is pointed towards the large end, and since direction of force is equal to the direction of acceleration by the definition of a force, this means that according to this theory, the EMDrive should move large end forward, contrary to all experimental evidence.
Please actually think this through, and don't say I am treating this like a rocket engine, since I am not, I only used the definition of force. I ignored all other issues such as conservation of momentum (how do the photons change momentum between the end plates other than through a force on the sidewalls). -
#2514 by SeeShells on 17 May, 2016 02:53
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He uses the fact that the RF injection is continuing to push passengers into the cavity, and as you say those passengers get pushed to the big end. More and more passengers keep getting pushed into the big end.I've read Mculloughs proposal over and over. I'm still struggling. What is the crux of this position? All I can gleam out is its similar to cassimir effect of excluding wavelengths causing a difference in em pressures. Is it some how the microwaves act like the plates in a cassimir effect? But due to internal geometry the big and small end are excluding differing em wavelengths averaged? Therebye giving a differential in momentum between high and low density energy regions of frostrum?
From looking at his theory and reading some of the recent explanations here, I am having trouble seeing how this theory would produce a continuous force. The descriptions are comparable to a stationary train on a frictionless surface where the passengers decide to all get up and walk to the back. The train will move forward on the rails to keep the center of mass constant, but then stop when people reach the back of the train and can't go back any further.
Going back to the frustum, reaching steady state resonance would be like everyone reaching the back of the train, since then the photons at the back which are "heavier" start getting absorbed back into the walls of the cavity and everything balances out. This could produce a noticeable effect in most laboratory experiments, but be useless for space propulsion. (Still potentially new physics which would be cool)
I assume I am missing something where the Unruh waves carry away momentum to allow the drive to continuously accelerate.
When the RF power is turned off, no more passengers keep getting pushed into the train, and the train stops when the power is off.
Is this an artifact of the fact that the passengers start at their house (the stationary power supply) and walk (through a flexible tunnel: the coax cable) into the train ?
And the fact that experimenters are only looking at the movement of the train, and completely ignoring the movement of the passengers that are walking into the train?
Could the train move if the passengers would all be on top of the train to start with, and then drop inside the train through the train's roof (using batteries)?
Don't forget that the passengers that leap off the end of the platform onto the train tracks all of a sudden looking back at the train station see it frozen in time and can not interact with anything happening on the station. Causality rules here.
Shell -
#2515 by VAXHeadroom on 17 May, 2016 03:19
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In the one big simulation I ran in meep (aero's data, seeshell's design) I found the magnetic field had a ~3x larger energy density impingement on the small end (middle of thread 6). If we follow the same line of reasoning, then thrust should be towards the small end (based on this one simulation). The small and large end plate energy graphics are attached.Attached is the guide wavelength plot for my 1st build. As the EmWave momentum is directly related to the inverse of the guide wavelength (longer guide wavelength = smaller EmWave momentum), the reverse of the attached curve shows how EmWave momentum drops as the guide wavelength lengthens as it approaches the small end.
...
Per what you said here, the total momentum of photons reflecting off the small plate is smaller than the momentum of the photons reflecting off the large plate. As known from many experiments such as Cullen's, the photons reflecting off plates apply a force to the plate in the direction they were moving before hitting the plate (assuming a head on direction for simplicity). If you are confused which direction this is, bounce a ball off some movable object and look what direction the object moves, it is the same thing.
From what you just said, the force on the small plate is smaller than the force on the large plate. This means that (assuming 0 force on the sidewalls) the net force on the metal cavity is pointed towards the large end, and since direction of force is equal to the direction of acceleration by the definition of a force, this means that according to this theory, the EMDrive should move large end forward, contrary to all experimental evidence.
Please actually think this through, and don't say I am treating this like a rocket engine, since I am not, I only used the definition of force. I ignored all other issues such as conservation of momentum (how do the photons change momentum between the end plates other than through a force on the sidewalls).
Bah. I have to re-create one of the data files to get the exact numbers. It'll take 45 minutes and I don't think I can keep my eyes open that long
Here are the graphic files - I'll post the CSV summation data in the morning...
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#2516 by spupeng7 on 17 May, 2016 07:38
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Not comprehending how Unruh radiation works but I like this argument. Nice explanation. Shell is still right though, the only thing we know that can exert force through the frustum walls is gravity, which is one of the reasons I pursue an explanation allowing gravity as an electromagnetic effect.
So, in General Relativity the energy E and momentum p obey the relativistic energy–momentum relation
I was about to post how I assumed that the "higher inertial mass" near the large end in Dr. McCulloch's theory must be meant in a way that the total momentum in the photons is reduced when the mass increases.* This post from him confirms he understands the direction issue with Shawyer's theory, so he isn't likely to be making the same mistake, and comparisons of his McCulloch's increased mass to Shawyer's increased momentum are wrong.Interesting new comment from Dr. Mike McCulloch on his EmDrive theory:
https://twitter.com/memcculloch/status/731774299380568064?s=01
Both Mike & Roger talk about the thrust being produced by larger EmWave momentum / mass at the big end and smaller EmWave monentum / mass at the small end with the EmDrive thrust being the result of gained momentum from the lost EmWave momentum / mass differential between the big & small ends.
http://physicsfromtheedge.blogspot.com/2015/06/crit-of-shawyers-emdrive-theory.html
* I don't understand how inertial mass even makes sense when talking about photons, but McCulloch's theory has room with new physics, general relativity, and interactions between photons and other radiation that can presumably carry momentum away from the cavity. My limited understanding is that the increase in mass comes with transfer of momentum to Unruh waves, so that the momentum decreases despite the increase in mass. I could be off base, and there are other consistent interpretations I can think of.
In general relativity, gravity affects anything with momentum and energy. Photons do not have a rest-mass, but they do have momentum, and energy--and they are thus effected by gravity (photons cannot leave a black hole and their path in space is affected by the geodesics imposed by a massive object like the Sun).
...
where the rest mass mo is the rest mass, which is an invariant, so since photons have zero rest mass:
mo = 0, we have
which says that a photon's momentum is a function of its energy, and also its velocity is an invariant: the speed of light in vacuum, c
Therefore the "inertial mass" that McCulloch is discussing is not the relativistic concept of rest mass, which is an invariant, but McCulloch's "inertial mass" is instead a measure of its momentum.
The De Broglie expression for the photon's momentum is
One could divide this momentum by the speed of light in vacuum, c, to get a momentum that has "mass units":
p/c = h/(c λ)
which is a relativistic mass
where the Lorentz factor γ is defined as follows (and using nomenclature where the speed is v=u, sorry about using Wikipedia images for equations that use different nomenclature for the speed in different articles)
(Notice that the relativistic mass for a photon is undefined since the rest mass mo for a photon is zero while γ becomes infinite at v=u=c, since the photon speed v=u is c, and this entails multiplying zero by infinity which is undefined, so again, it is better to think of this expression as being momentum measured in "mass units")
Somebody at the "other EM Drive forum" trying to debunk McCulloch wrote:QuoteSo far I believed, that having standing waves inside the cavity of any shape implies, these waves have everywhere the very same wavelength. First of all we should demonstrate, that the wavelength of standing waves changes inside the conical resonator along its axis - if it doesn't change, then no dependence of photon mass on wavelength applies and the whole above line of reasoning is wrong with massive photons or without them (not to say, it would be also redundant with respect to the "Unruh radiation" stuff anyway).
No,on the contrary: while cavities with constant cross-section do have standing waves that have constant wavelength along the longitudinal axis, tapered cavities like the EM Drive have monotonically changing wavelength along the longitudinal axis. For example, for a truncated cone with spherical ends, the exact solution is given by spherical Bessel functions, which have non-uniform wavelength along the longitudinal axis.
See, for example: http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html
[Small end is at left and big end is at right. The cavity cross-section increases with increasing "r" which is the spherical radius with r=0 being at the vertex of the cone]
In an EM Drive, the wavelength is smaller towards the big end and the wavelength gets bigger towards the small end:
So McCulloch's measure of momentum in "mass units"
p/c = h/(c λ)
does change along the longitudinal axis of the EM Drive:
for a cavity with constant cross-section like a cylindrical cavity, the momentum of the photons is constant along the longitudinal axis. However, for a cavity like the EM Drive, the momentum of the photons changes with their location along the longitudinal axis.
Since in an EM Drive, the wavelength is smaller towards the big end and the wavelength gets bigger towards the small end, p/c = h/(c λ) means that the "momentum in mass units" p/c = h/(c λ) gets larger towards the big end and smaller towards the small end
Hence, when McCulloch writes:
I interpret this as saying MiHsC shifts "momentum in mass units" from the microwave injection towards the big end of the tapered cavity, so as new microwave energy is put into the cavity its centre of momentum is continually being shifted by MiHsC towards the wide end.
It is also interesting that in special relativity, the center of momentum frame is necessarily unique only when the system is isolated, which is something that makes non-isolated experiments questionable. This is another reason why experiments using a power cord are questionable, since the power cord goes to a stationary power supply, hence the center of momentum in experiments with a power cord may NOT be in the moving platform, and why experiments with batteries in the moving platform (as the latest experiments by Yang that nullified her previous experimental claims, and also as the experiments by Hackaday Aachen team) are much more convincing. http://users.physics.harvard.edu/~morii/phys151/lectures/Lecture16.pdf
Experiments using power cords ignore the electromagnetic momentum being fed from a stationary power supply.
The faraday cage blocks AC, so what we are looking for is not quite AC. Not quite AC is what we have in this asymmetric guide, is it not?
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#2517 by dustinthewind on 17 May, 2016 08:53
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I can't say this is directly related to what your talking about. It is just that it seems like it might be. I was talking to WarpTech elsewhere a bit about the polarizable vacuum concept. Here is a paper on the concept: https://scholar.google.com/scholar?hl=en&q=puthoff+pv&btnG=&as_sdt=1%2C48&as_sdtp= 2nd one down from arxiv "Polarizable-vacuum (PV) representation of general relativity", Puthoff's papers on PV. WarpTech pointed out that as the K value increases as you near say a planet that the momentum actually increases as p(K) = p0*K^1/2. If I did it right I figured the velocity decreases with K as v(K)=vo/K . He gave that m(K)=mo*K^(3/2) and the energy decreases with K as E(K)=Eo/K^(1/2). a(K)=ao/K^(3/2). Force and a few other products appear to remain constant and give the effect of slowing light down near gravitational objects.
I am not sure this is connected to what your talking about, (probably not). I doubt the magnitude matches, or I am unsure how the inside of a cavity could compare to a planet. However, you mentioned the wavelength getting longer near the narrow end but that the momentum would decrease. However in the PV concept the momentum increases because the mass increases at a more rapid rate than the velocity decreases while the light near the gravitational object red-shifts (slows in frequency via time slowing down or becoming heavier). I almost wanted to picture it as a sort of matter mist condensing on the photon. The idea in the PV concept is that light slows down near gravitational objects to give the gravitational lensing effect. However a local observer detects no change in the velocity of light. I think the details are in the paper. -
#2518 by VAXHeadroom on 17 May, 2016 12:32
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In the one big simulation I ran in meep (aero's data, seeshell's design) I found the magnetic field had a ~3x larger energy density impingement on the small end (middle of thread 6). If we follow the same line of reasoning, then thrust should be towards the small end (based on this one simulation). The small and large end plate energy graphics are attached.Attached is the guide wavelength plot for my 1st build. As the EmWave momentum is directly related to the inverse of the guide wavelength (longer guide wavelength = smaller EmWave momentum), the reverse of the attached curve shows how EmWave momentum drops as the guide wavelength lengthens as it approaches the small end.
...
Per what you said here, the total momentum of photons reflecting off the small plate is smaller than the momentum of the photons reflecting off the large plate. As known from many experiments such as Cullen's, the photons reflecting off plates apply a force to the plate in the direction they were moving before hitting the plate (assuming a head on direction for simplicity). If you are confused which direction this is, bounce a ball off some movable object and look what direction the object moves, it is the same thing.
From what you just said, the force on the small plate is smaller than the force on the large plate. This means that (assuming 0 force on the sidewalls) the net force on the metal cavity is pointed towards the large end, and since direction of force is equal to the direction of acceleration by the definition of a force, this means that according to this theory, the EMDrive should move large end forward, contrary to all experimental evidence.
Please actually think this through, and don't say I am treating this like a rocket engine, since I am not, I only used the definition of force. I ignored all other issues such as conservation of momentum (how do the photons change momentum between the end plates other than through a force on the sidewalls).
Bah. I have to re-create one of the data files to get the exact numbers. It'll take 45 minutes and I don't think I can keep my eyes open that long
Here are the graphic files - I'll post the CSV summation data in the morning...
OK - the 3x number I was doing from memory and wasn't right, but the small end energy is 1.64x the big end. Attached are the CSV files from which the graphics are made. If you open them up in a spreadsheet and add up all the values (press CTRL-A and look at the summary on the bottom right in Open Office or Excel) you can see the total (all numbers are positive). I'm not going for scale here (watts/newtons/etc), just the imbalance in energy. Also note for the big end the area in the spreadsheet corresponding to the square waveguides should be excluded - it's approximately balanced by the other face of the waveguide (I proved this to myself by looking at the data) although even including it shows an imbalance favoring the small end.
Also attached is the POVRay source. I don't expect folks to understand this entirely, but the key equation is on line 112:
#declare tmp_mag_field = abs( VCos_Angle(csv_vector[row][col], z) ) * vlength(csv_vector[row][col]);
VCos_Angle returns a number that is the cosine of the angle between the 3D vector of the H field and the Z vector <0,0,1>; meaning that if the magnetic vector is normal to the plane, you get 1.0 and if it's parallel to the plane you get 0. This is then multiplied by the vector length which is the intensity of the H field at that location.
So: I know this is the correct equation for the thermal energy going into the plane at this location.
However it's also the equation for the diamagnetic energy reflected from the copper.
Yes, that reflection is small (1e-5 for copper) but there is an imbalance and the effect we see in 'anomalous thrust' is also quite small. Note also this doesn't take into account any of the data from the sloped sides.
Diamagnetism is a quantum effect (per Feynman), and so isn't accounted for by equations from Maxwell or Faraday. I don't yet entirely understand the data I'm seeing, but given the same material on both faces (copper) and the same frequency of microwaves (~2.45Ghz) throughout the cavity could this imbalance in diamagnetic reflection produce a mechanical effect? Is the frustum 'standing' or floating on the microwave energy and being shifted in one direction (toward the small end) by the diamagnetic repulsion? If this was a motor, I'd talk about it as a rotor and a stator. In this case, people would like this to be a linear motor (what's the linear motor equivalent term of 'rotor'?) So I'm thinking about this as the EM field being the rotor and everything else (the frustum and its attached spacecraft) being the stator. The EM field generates a linear magnetic impulse and the frustum shifts to compensate.
I can't speak to the general case (yet) only this one simulation result. I don't want this to degenerate into another COE/COM VIOLATION harangue. Yes, that's probably the key issue for the device, but given this one set of data can we say something about it?
One magnetics/Rf question: Is the diamagnetic effect scaled by the frequency? That is: based on the fact that the skin depth decreases with frequency, I might expect the diamagnetic effect to be proportional to the skin depth i.e. the total volume of copper generating the magnetic reflection. I can't find that anywhere, but I don't have any real Rf textbooks - 2 hours on google turned up nothing...
(edit: fixed attachments)
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#2519 by Rodal on 17 May, 2016 12:41
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Puthoff's approach is unconventional, leading to a variable speed of light in vacuum (c is a function of K, other "constants" become a function of K) and other unconventional ways to look at things. What is K? Puthoff writes "K is the (altered) dielectric constant of the vacuum (typically a function of position) due to (GR-induced) vacuum polarizability changes under consideration."...
I can't say this is directly related to what your talking about. It is just that it seems like it might be. I was talking to WarpTech elsewhere a bit about the polarizable vacuum concept. Here is a paper on the concept: https://scholar.google.com/scholar?hl=en&q=puthoff+pv&btnG=&as_sdt=1%2C48&as_sdtp= 2nd one down from arxiv "Polarizable-vacuum (PV) representation of general relativity", Puthoff's papers on PV. WarpTech pointed out that as the K value increases as you near say a planet that the momentum actually increases as p(K) = p0*K^1/2. If I did it right I figured the velocity decreases with K as v(K)=vo/K . He gave that m(K)=mo*K^(3/2) and the energy decreases with K as E(K)=Eo/K^(1/2). a(K)=ao/K^(3/2). Force and a few other products appear to remain constant and give the effect of slowing light down near gravitational objects.
I am not sure this is connected to what your talking about, (probably not). I doubt the magnitude matches, or I am unsure how the inside of a cavity could compare to a planet. However, you mentioned the wavelength getting longer near the narrow end but that the momentum would decrease. However in the PV concept the momentum increases because the mass increases at a more rapid rate than the velocity decreases while the light near the gravitational object red-shifts (slows in frequency via time slowing down or becoming heavier). I almost wanted to picture it as a sort of matter mist condensing on the photon. The idea in the PV concept is that light slows down near gravitational objects to give the gravitational lensing effect. However a local observer detects no change in the velocity of light. I think the details are in the paper.
Some of this is reminiscent of the Unruh effect (that the Quantum Vacuum effect depends on the acceleration of the observer). I can't comment on this approach: it would take me some time to study it.
Has it been shown to be compatible with our astrophysical measurements and to not lead to contradictions?
The wikipedia article states:Quoteit satisfies three of the four classical tests of relativistic gravitation (redshift, deflection of light, precession of the perihelion of Mercury) to within the limit of observational accuracy. However, as shown by Ibison (2003), it yields a different prediction for the inspiral of test particles due to gravitational radiation.
... In particular, this theory exhibits no frame-dragging effects. Also, the effect of gravitational radiation on test particles differs profoundly between scalar theories and tensor theories of gravitation such as general relativity. LIGO is not intended primarily as a test ruling out scalar theories, but is widely expected to do so as a side benefit once it detects unambiguous gravitational wave signals exhibiting the characteristics expected in general relativity.
Are there answers to this: https://en.wikipedia.org/wiki/Polarizable_vacuum#Criticism ?
Suggest Dave delete the one where he recommended I purchase it since it was one sale. 
