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#1020 by M.LeBel on 25 Aug, 2017 01:36
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My main concern is that our Chinese friends have gone quiet. After all the buzz surrounding their secret testing and supposed space test there has not been a single word from them. Either their government put a halt on discussing the subject or people have lost interest. Both are detrimental to experimental progress and future cubesat missions. We need to push for more international LEO testing campaigns or something tangible since it seems that all theory discussion for the entire summer has not made any headway (no interesting calculations or continuation of Warptech's thrust equation). Even Peter Lauwer, who seemed to have a solid experimental setup, has gone quiet.
Still stuck on CoE and laser thrusters? Seriously? These are the oldest most worn out lines of thought and areas to debate. It almost seems like some are chatting for the sake of posting something, not contributing something new. Let's please move back to a higher level discussion involving the wide variety of actually new and relevant research and theory from Estes and Eagleworks and including peer reviewed sources fully compliant with the standard model or string theory. For example let's consider that we can now create two dimensional complicated floquet time crystals. You can start to see how a cavity lined with these may break causality for resonant particles within. Or rather that is the question: is it possible to create a macroscopic region of space with complex time... even a time machine based on the boundary conditions*? https://m.phys.org/news/2017-08-unconventional-quantum-optical-devices.html
In other research a tunable mode-based transparent metamaterial has been created allowing for a potential feedback system activating and automatically transmitting resonant waves above and below desired frequencies. This is huge for removing noise from the cavity and rejecting splatter if designed correctly and with well placed sensors, or even program the response profile into the material itself by using empirically determined eigenmode values and detected boundary incoming waveforms. http://www.sciencedirect.com/science/article/pii/S0030401817300652
Alternatively we could hypothesize about which metamaterials and permittivity would lead to the highest Q factor. There are exotic options such as near zero permittivity or time varying permittivity or even layered varying permittivity values (such as with silica wafers which can lead to lovely waveform variations depending on the metamterial. We are at the forefront of a brave new world of quantum optics and metamaterial research, why not increase the gain and tweak the properties of light which we desire in order to begin disproving theories of operation and improving thrust?
*see here also smolyaninov's old papers on symmetry breaking at negative refraction index and consider relativistic resonant electrons
... Something new?
All these empirical equations being shuffled around here contain the variable t for `time`. Nobody understands what Time is. Conclusion; nobody understands what they`re really doing. It is all empirical.
We control all variables except time. And gravity is just that; `the unequable flow of time from place to place`(Unruh).
Do we seriously want (or have a chance) to locally control the flow of time without first asking and understanding what time is?
We must first understand (not the description) how the universe makes gravity before we can do it ourselves. It, is, that, simple.
Comments:
- We often see people saying something like `at a relativistic speed` or near c during some explanation. The fact is that GR is true at all speed as it has no lower bound where it stops or break down. It is just an empirical limit too often used for the engineering rounding off. Physics (or philosophical) rounding off is not acceptable in the theory or explanation. It is only acceptable in the preparation of an empirical (measurable) demonstration. If I throw a ball, it gets heavier, even if it is not measurable, and it is certainly not insignificant in terms of understanding.
Food for thought -
#1021 by moreno7798 on 25 Aug, 2017 01:47
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In its instantaneous rest frame at any point it is not moving, and there is literally nothing different about it so there is no reason it would be producing less thrust. You have described no mechanism that would in any way be capable of tracking "time since it last was off."During continual acceleration, as KE increases, the energy to support increasing Work and KE is sourced from cavity energy, increasing energy loss per cycle, dropping Q and dropping N.
Because it makes no sense, it implies that an emdrive that has been accelerating for 10 minutes will produce less force than one that has been accelerating for 10 seconds, when there is nothing physically different between them. There is no mechanism by which it can tell the difference, the RF is from a co-moving source, so there will not be Doppler problems, and you have claimed that simply turning it back off and then back on will reset the magic tracking how long it was running for by some additional magic.
Why is this so hard to accept?
Now go back and take a look at the example of Major Tom's ship running for 1 second. It produces 3 times the energy that was put in.
There is a fixed amount of energy entering the cavity per cycle. Increasing KE and Work energy, due to increasing velocity, is supplied from that fixed cavity energy input, which increases energy loss per cycle, dropping Q and dropping thrust.As for Major Tom's ship, with initial acceleration of 12.5m/s^2, the KE significantly increases on a millisecond level, reducing thrust very quickly as you can see in the plot I posted which is based on a 65ms resolution over 500k samples.
Telling me the resolution and number of samples tells me nothing about the equation you are using. What velocity do you claim his ship is moving at after 1 second, and how exactly do you arrive at that answer?
It would be nice if you re-enforced your counter argument with the math to prove your point. Regurgitating "No because I said so" means very little. -
#1022 by meberbs on 25 Aug, 2017 04:48
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I did, about 3 messages back, and I also was asking for equations from TT so that I can do further math, but he has yet to provide them. TT has yet to provide any math (except clearly wrong math that was promptly disproved) or coherent logic to back up any of his assertions. (Or experimental evidence as Rodal pointed out) Your comment would be better directed to TT, although his are more along the lines of "no because Shawyer said so" even though Shawyer has repeatedly demonstrated he can't even do a simple force balance.
In its instantaneous rest frame at any point it is not moving, and there is literally nothing different about it so there is no reason it would be producing less thrust. You have described no mechanism that would in any way be capable of tracking "time since it last was off."Because it makes no sense, it implies that an emdrive that has been accelerating for 10 minutes will produce less force than one that has been accelerating for 10 seconds, when there is nothing physically different between them. There is no mechanism by which it can tell the difference, the RF is from a co-moving source, so there will not be Doppler problems, and you have claimed that simply turning it back off and then back on will reset the magic tracking how long it was running for by some additional magic.
Now go back and take a look at the example of Major Tom's ship running for 1 second. It produces 3 times the energy that was put in.
There is a fixed amount of energy entering the cavity per cycle. Increasing KE and Work energy, due to increasing velocity, is supplied from that fixed cavity energy input, which increases energy loss per cycle, dropping Q and dropping thrust.As for Major Tom's ship, with initial acceleration of 12.5m/s^2, the KE significantly increases on a millisecond level, reducing thrust very quickly as you can see in the plot I posted which is based on a 65ms resolution over 500k samples.
Telling me the resolution and number of samples tells me nothing about the equation you are using. What velocity do you claim his ship is moving at after 1 second, and how exactly do you arrive at that answer?
It would be nice if you re-enforced your counter argument with the math to prove your point. Regurgitating "No because I said so" means very little. -
#1023 by RERT on 25 Aug, 2017 10:15
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Can we imagine that the EMdrive is an electric rocket with an invisible, inexhaustible reaction mass (which it finds along the way)?
It might be a miracle, but let's see if we can limit ourselves to just that miracle.
The rocket is always in its own rest frame. In that rest frame physics is always the same, the operation of the rocket is constant until it runs out of power supply. It seems unavoidable that the acceleration of the rocket is also constant, ie thrust is constant, in its instantaneous rest frame.
If the rocket were a chemical rocket, we would say that the KE of the rocket plus the KE of the exhaust equals (best case) the reduction in the chemical potential energy of the fuel, and be easily satisfied that that must be true in all inertial frames. That is completely independent of the acceleration profile of the rocket, in other words true for constant acceleration.
A chemical rocket can operate with any value of thrust/power dependent on the exhaust velocity.
So, it cannot be that such a (miraculous) electric rocket is necessarily OU when a corresponding chemical rocket, with exactly the same acceleration profile and thrust/power, is not.
As an aside, we are being pretty ambitious trying to calculate the energy balance when the exhaust is invisible and, for all we know, the potential energy of the vacuum might be changing...
If someone can clear up where I've gone wrong, I'd be very grateful.
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#1024 by Rodal on 25 Aug, 2017 14:42
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Can we imagine that the EMdrive is an electric rocket with an invisible, inexhaustible reaction mass (which it finds along the way)?
As I understand it, you are asking us to << imagine that the EMdrive is an electric rocket with an invisible, inexhaustible reaction mass (which it finds along the way)?>> and then for us to <<clear up where I've gone wrong, I'd be very grateful.>>.
It might be a miracle, but let's see if we can limit ourselves to just that miracle.
The rocket is always in its own rest frame. In that rest frame physics is always the same, the operation of the rocket is constant until it runs out of power supply. It seems unavoidable that the acceleration of the rocket is also constant, ie thrust is constant, in its instantaneous rest frame.
If the rocket were a chemical rocket, we would say that the KE of the rocket plus the KE of the exhaust equals (best case) the reduction in the chemical potential energy of the fuel, and be easily satisfied that that must be true in all inertial frames. That is completely independent of the acceleration profile of the rocket, in other words true for constant acceleration.
A chemical rocket can operate with any value of thrust/power dependent on the exhaust velocity.
So, it cannot be that such a (miraculous) electric rocket is necessarily OU when a corresponding chemical rocket, with exactly the same acceleration profile and thrust/power, is not.
As an aside, we are being pretty ambitious trying to calculate the energy balance when the exhaust is invisible and, for all we know, the potential energy of the vacuum might be changing...
If someone can clear up where I've gone wrong, I'd be very grateful.
Well, I would say that we should start by that first step. What is the experimental, observational, logical or scientific basis to consider an "invisible, inexhaustible reaction mass (which it finds along the way)?"? -
#1025 by meberbs on 25 Aug, 2017 15:03
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Can we imagine that the EMdrive is an electric rocket with an invisible, inexhaustible reaction mass (which it finds along the way)?
Finding it along the way implies some relative velocity to that reaction mass and thrust/power is now a function of relative velocity to that medium. If you specify that part of the "miracle" is that you there is always some of that mass moving with the same velocity as the drive, then you still get the result that it is an energy generator, but you can now explain that the energy comes from the kinetic energy of that mass. (And logic implies you in some way locally depleted the parts of that mass moving with your velocity.)A chemical rocket can operate with any value of thrust/power dependent on the exhaust velocity.
How would a normal rocket have the same acceleration profile and thrust/power? The mass of the normal rocket is changing, so constant acceleration involves a decreasing thrust. Thrust/power is not a well defined number for a standard rocket, because every frame seems a different kinetic energy of the exhaust. Conservation of energy only applies in an inertial frame, and due to the changing kinetic energy of the propellant before it is exhausted, it is simply not true that the chemical rocket can operate with an arbitrary thrust/power.
So, it cannot be that such a (miraculous) electric rocket is necessarily OU when a corresponding chemical rocket, with exactly the same acceleration profile and thrust/power, is not.As an aside, we are being pretty ambitious trying to calculate the energy balance when the exhaust is invisible and, for all we know, the potential energy of the vacuum might be changing...
Shawyer's explanation of the device does not have invisible exhaust, since he claims no new physics. This means there is no exhaust velocity to worry about and the device trivially breaks conservation of energy and momentum. Theories where there is some form of exhaust don't necessarily do this, but most would introduce a special frame the efficiency is relative to based on the motion of the medium the emDrive is using as exhaust.If someone can clear up where I've gone wrong, I'd be very grateful.
I hope this helps. -
#1026 by Gilbertdrive on 25 Aug, 2017 16:02
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Shawyer's explanation of the device does not have invisible exhaust, since he claims no new physics. This means there is no exhaust velocity to worry about and the device trivially breaks conservation of energy and momentum. Theories where there is some form of exhaust don't necessarily do this, but most would introduce a special frame the efficiency is relative to based on the motion of the medium the emDrive is using as exhaust.
Very well summarized ! -
#1027 by Bob012345 on 25 Aug, 2017 18:44
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Therefore there is an easy way to resolve this (besides using "prior beliefs" and accepted laws of physics): does Shawyer have experimental data showing this phenomenon ? ( that an emdrive that has been accelerating for 10 minutes will produce less force than one that has been accelerating for 10 seconds, and that simply turning it back off and then back on will reset the magic tracking how long it was running for by some additional magic)During continual acceleration, as KE increases, the energy to support increasing Work and KE is sourced from cavity energy, increasing energy loss per cycle, dropping Q and dropping N.
Because it makes no sense, it implies that an emdrive that has been accelerating for 10 minutes will produce less force than one that has been accelerating for 10 seconds, when there is nothing physically different between them. There is no mechanism by which it can tell the difference, the RF is from a co-moving source, so there will not be Doppler problems, and you have claimed that simply turning it back off and then back on will reset the magic tracking how long it was running for by some additional magic.
Why is this so hard to accept?
Now go back and take a look at the example of Major Tom's ship running for 1 second. It produces 3 times the energy that was put in.
There is no magic.
Just physics based on local, to the accelerating mass, pre and post acceleration rest frames.
During acceleration, the energy that supports increasing KE is sourced from cavity energy, which drops Q and drops force. To think force is constant as KE increases and there is a constant inflow of Rf energy is madness.
The EmDrive was never OU, except to those that never bothered to listen to Roger who has always said cavity energy is divided between energy to support KE and that left to generate thrust.
Please listen to what Roger explains from 11.32
https://www.youtube.com/watch?v=wBtk6xWDrwY?t=690
Consider that if KE = cavity input energy then energy loss per cycle = input energy per cycle, Q = 1 and thrust is < photon rocket thrust as Df < 1.
It might be more fruitful to consider that since a force is the gradient of some potential energy, what potential energy is created in the cavity whose gradient is the force? Then consider that the mechanisms that do that are lossy and that that energy ends up as heat. It doesn't necessarily take energy to maintain a force (like the force of a book resting on a table) but the mechanisms for EMDrive and MEGA drive devices are lossy. Finally, once to you create the force, just let nature do the work. She does the right amount of work as computed in every reference frame for all observers.
Also, I can accept that there would be a relationship between the force and acceleration but that could result from loss mechanisms due to Doppler shifts or other phenomenon and not from imparting kinetic energy to the device. If static tests show all the input Rf becomes heat, I suspect dynamic tests would show that too but that will eventually be testable. In fact, if the Rf energy is the source of the kinetic energy, then the cavity should be self-cooling under greater acceleration becoming even more efficient. There would be measurable less heat dissipated if the EMdrive is undergoing a constant acceleration than in a static test. -
#1028 by OnlyMe on 25 Aug, 2017 19:49
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….
There is no velocity in the inertial frame of the EmDrive. Needs another frame to provide a velocity reference. But which to use: Velocity of orbit around galactic hub? Velocity of orbit around the sun? There are almost an infinite number to choose from.
Or maybe zero velocity from the last inertial frame of the EmDrive before acceleration started? To me that rest frame as zero velocity at the start of acceleration makes sense.
…
TT, repeatedly it seems your argument(s) depend on interpreting the EmDrive within the context of Newtonian physics. Not even Special Relativity since it seems there is no clear account of relativistic effects.
When you continually attempt to invoke an ever changing rest frame of the EmDrive, as a preferred frame, you lock your argument to an entirely flat spacetime and the empty space of Newton. That is not even close to real world physics, even where Newtonian mechanics remains a valid approximation of the observable dynamics.
In reality, there is no time we can expect that any EmDrive will be operating outside of a gravitational field, the complexity of which increases as does the scope of discussion. Even the galactic hub and all other mass within the galaxy has some impact on what happens here in our local speck of spacetime.
The point is space is not empty in the Newtonian sense. Once you start talking about spaceships and EmDrives traveling to or between planets, space isn’t even entirely limited to conditions defined within Special Relativity.
Once you turn an EmDrive on, all acceleration, whether it is continuous or broken into a series of events, remains relative to its initial inertial rest frame. A frame of reference associated with the earth, the sun, the galaxy as a whole and even the stars and galaxies in the far distance.
You cannot when dealing with orbital mechanics and travel between planets, ignore the dynamics of the gravitational field, which in itself IS the constantly changing frame of reference, within which the drive’s performance must be evaluated.
Set aside the possibility of any sort of interaction with any interpretation of the quantum vacuum, your EmDrive is also moving and accelerating relative to a very real electromagnetic background, and the boundary conditions associated with that interaction, no matter how small, must be treated as real and asymmetric, as a function of both the local dynamics of acceleration, proximity of massive objects and the gravitational field in general.
Space is not empty in the Newtonian sense, not even flat in the sense of Special Relativity and any assumption that the EmDrive’s operation is dependent on a constantly changing instantaneous rest frame that moves with the drive, does not seem a realistic approach to a credible explanation of how it works.., if it works.
I still tend to hope/believe that an anomalous thrust will eventually be demonstrated. I am also certain that if/when it is, it will be the result of New Physics. Even if that New Physics winds up no more that an improved understanding of the dynamics of the interaction between a frustum and the contained resonating electromagnetic field(s).
You cannot dismiss the affect of the real world the drive moves through and relative to, by asserting that it functions relative to its own constantly changing instantaneous rest frame. -
#1029 by TheTraveller on 26 Aug, 2017 07:29
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New EmDrive patent application
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#1030 by TheTraveller on 26 Aug, 2017 07:32
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You cannot dismiss the affect of the real world the drive moves through and relative to, by asserting that it functions relative to its own constantly changing instantaneous rest frame.
Of course it is more complex. However that does not invalidate using the pre acceleration rest frame as the initial velocity external frame to measure distance moved, Work done and KE gained. -
#1031 by TheTraveller on 26 Aug, 2017 07:38
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Also, I can accept that there would be a relationship between the force and acceleration but that could result from loss mechanisms due to Doppler shifts or other phenomenon and not from imparting kinetic energy to the device. If static tests show all the input Rf becomes heat, I suspect dynamic tests would show that too but that will eventually be testable. In fact, if the Rf energy is the source of the kinetic energy, then the cavity should be self-cooling under greater acceleration becoming even more efficient. There would be measurable less heat dissipated if the EMdrive is undergoing a constant acceleration than in a static test.
Correct. Well deduced. There is less thermal radiation by the cavity as KE drains cavity energy.
Same thing happens with a 1m^2 solar panel, ie no load = 1kW heat to radiate, 250W load = 750W to radiate. -
#1032 by TheTraveller on 26 Aug, 2017 07:47
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As I understand it, you are asking us to << imagine that the EMdrive is an electric rocket with an invisible, inexhaustible reaction mass (which it finds along the way)?>> and then for us to <<clear up where I've gone wrong, I'd be very grateful.>>.
Well, I would say that we should start by that first step. What is the experimental, observational, logical or scientific basis to consider an "invisible, inexhaustible reaction mass (which it finds along the way)?"?
No not at all.
Inelastic Compton effect photons impacting end plate bound metallic atom electrons allows momentum and energy transfer from the trapped impacting photons to the end plate metallic atoms. In reaction the photons lose momentum, energy and their wavelength increase.
It is the loss of trapped photon momentum and energy that provides the increased EmDrive momentum, Work done and KE increase.
Momentum is conserved and Energy is conserved.
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#1033 by LowerAtmosphere on 26 Aug, 2017 10:17
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TheTraveller,
You do realise that the wall electrons cannot differentiate between an incident wave which has been reflected and one which is original? The only way I could interpret your posts as making sense is if you claim that the walls transmit the KE in a different direction over time as they gain energy and increase current. So instead of the KE vector being net outward the vector becomes circular (locked dipole less overall net direction)?
This would make a bit more sense. At first the cavity absorbs/reflects/transmits incident waves in a net direction (big endian), though as current increases and the walls reach saturation more of the energy will be redirected towards the closed circuits and eddies both within the internal atmo and in the walls like baseballs in a hurricane. -
#1034 by meberbs on 26 Aug, 2017 14:41
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...
Momentum is obviously not conserved. Start with an emDrive at rest, it has 0 momentum. Run it for a while, and then turn it off. It now has momentum, but nothing has left the cavity, and there is nothing inside the cavity moving the opposite direction. The only thing that could possible leave the cavity is IR radiation, but that would at best have the momentum of a photon thruster. Obviously nothing in the cavity is moving the opposite direction, because if it was it would soon hit the back of the cavity and make the cavity stop moving forward.
Momentum is conserved and Energy is conserved.
Therefore there in now net forward momentum that a closed system has acquired from no external interactions. This is the very definition of breaking conservation of momentum.
Your counterargument is logically equivalent to the following conversation between "A" and "B"
A: 1+1+1+1 = 5
B: that is wrong, and breaks basic addition
A: no it doesn't, because 1+1 = 2, so 1+1+1+1 = 2+2
B: yes, but 2+2 is not equal to 5.
It doesn't matter if you show that 1 intermediate step is done correctly, when there is another that is wrong.
Now why haven't you responded yet to the simple question I asked in the last post I directed to you? Are you afraid that you answer will allow me to demonstrate how wrong you are about energy conservation? -
#1035 by RERT on 26 Aug, 2017 14:56
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meberbs - let me try another way. Drive a chemical rocket at constant proper acceleration along a given trajectory. Now send an emdrive on the same trajectory with the same proper acceleration, and an INVISIBLE exhaust. How can one necessarily be OU, but the other not? If you could see the exhaust they would appear identical to a distant observer.
Yes, it's a big miracle, violates standard physics, and we can't think how it might work. I don't think that changes the above. I'm not trying to argue that Shawyers explanation is correct. If it obeys standard physics, it breaks COE. But once we have concluded that it violates standard physics, onward deductions that it is OU are on shaky ground.
Rodal - thank you for your response, I hope you enjoyed it. -
#1036 by wicoe on 26 Aug, 2017 15:05
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Now send an emdrive on the same trajectory with the same proper acceleration, and an INVISIBLE exhaust. How
What is more likely: a systematic experimental error or an "invisible exhaust"? -
#1037 by Bob012345 on 26 Aug, 2017 15:13
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Also, I can accept that there would be a relationship between the force and acceleration but that could result from loss mechanisms due to Doppler shifts or other phenomenon and not from imparting kinetic energy to the device. If static tests show all the input Rf becomes heat, I suspect dynamic tests would show that too but that will eventually be testable. In fact, if the Rf energy is the source of the kinetic energy, then the cavity should be self-cooling under greater acceleration becoming even more efficient. There would be measurable less heat dissipated if the EMdrive is undergoing a constant acceleration than in a static test.
Correct. Well deduced. There is less thermal radiation by the cavity as KE drains cavity energy.
Same thing happens with a 1m^2 solar panel, ie no load = 1kW heat to radiate, 250W load = 750W to radiate.
Are you saying that in principle or in practice? In other words, I'd really have to see data for an accelerating cavity. -
#1038 by Chrochne on 26 Aug, 2017 15:42
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New EmDrive patent application
Phil. Perfect find. I did some digging around. That guy is a british billionaire businessman or at least they have same names. Will be looking for more information about him.
Ok correction: He is not a billionare. Just the same name. The guy is an american rotating equipment engineer working in turbine industry. Good luck to him in his endeavour. -
#1039 by Bob012345 on 26 Aug, 2017 15:56
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...
Momentum is obviously not conserved. Start with an emDrive at rest, it has 0 momentum. Run it for a while, and then turn it off. It now has momentum, but nothing has left the cavity, and there is nothing inside the cavity moving the opposite direction. The only thing that could possible leave the cavity is IR radiation, but that would at best have the momentum of a photon thruster. Obviously nothing in the cavity is moving the opposite direction, because if it was it would soon hit the back of the cavity and make the cavity stop moving forward.
Momentum is conserved and Energy is conserved.
Therefore there in now net forward momentum that a closed system has acquired from no external interactions. This is the very definition of breaking conservation of momentum.
I'm not saying I know but I'm uncomfortable with the statement that we know the only possible thing that can leave the cavity is IR radiation. It's a reasonable and logical assertion to be sure, but is it actually true? I think we should look more closely at Lorentz forces created in the device. Naturally, the very first thought anyone would have is that all such forces would necessarily cancel. They certainly do under the usual assumptions of steady state or quasi static induced currents. But Newton's Third Law is known to not hold in electrodynamic situations where events are spacelike due to the finite speed of light (see Feynman's Lectures). Therefore, a net force may occur under specific conditions. Here is some theoretical support;
http://przyrbwn.icm.edu.pl/APP/PDF/131/a131z5p21.pdf
Miron Tuval & Asher Yahalom "Newton’s Third Law in the Framework of Special Relativity" Eur. Phys. J. Plus (11 Nov 2014) 129: 240 DOI: 10.1140/epjp/i2014-14240-x. (arXiv:1302.2537 [physics.gen-ph]).
https://link.springer.com/article/10.1140/epjp/i2016-16374-1
Tuval and Yahalom show two current loops can have a net Lorentz force on the system which includes both which constitutes a space drive. Even Kirk McDonald of Princeton accepts that it works but thinks it wouldn't have any more momentum than a photon rocket. Of course, they disagree and show the momentum carried by the fields equal the momentum generated by the force on the device. So the debate continues.
http://www.hep.princeton.edu/~mcdonald/examples/tuval.pdf
Some points to consider about Lorentz forces on currents. First, magnetic fields pass through wires and could also pass through cavity walls. A century of electric motor design where fields pass through thick loops of copper wires proves that. So momentum carrying magnetic fields could escape. Then, in motors and other electrical devices, great forces and force changes are mediated by magnetic fields. Thus, huge amounts of momentum are mediated by those fields. Strictly speaking, they are always disjointed in time and thus the fields must be carrying momentum. The great internal forces cancel by Newtons Third Law on average so we don't notice any violations.
If true, it may be that the EMDrive is unintentionally creating such conditions and they are not optimized. I suspect the Cannae drive is more optimized for Lorentz forces. My suspicions are that Yahalom is correct.