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#1780 by WarpTech on 18 Oct, 2016 18:27
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There is a fundamental, huge difference between the Wright Brothers and Shawyer's insistence on an explanation that goes against both theoretical and experimental knowledge:
Photons are not balls and balls are not photons or complex EM waves so your device has no bearing on Shawyer's EmDrive or theory. Maybe, like the Wright Brothers who literally flew in the face of established aeronautical science, Shawyer intuitively knows more about what he's doing than his many critics.
1) Lord Kelvin said that flying machines were impossible because he based his opinion on air as a perfect fluid medium devoid of viscosity. The Wright Brothers took into account fluid viscosity by performing experiments in a wind tunnel. The experimental approach by the Wright Brothers was scientific and in accord with leading fluid mechanics experts at the time (for example Prandtl, Von Mises and Von Karman).
2) In great contrast to the Wright Brothers, the explanation by Shawyer goes against all fundamental knowledge of Maxwell's equations and experimental knowledge. There is nobody at a University I know of that agrees with Shawyer's explanations. Nobody at Cambridge University. Nobody at Oxford University. Nobody at MIT, Stanford, CalTech, you name it. Martin Tajmar, at TU Dresden who conducted experiments on the EM Drive under the advice of Shawyer has painstakingly divorced himself from Shawyer's explanations.
Many things in Shawyer explanation can be shown to be fundamentally wrong, foremost among this the fact that Shawyer persists, to this date, to claim that there is no radiation pressure on the conical side walls. To state, like Shawyer does that there is no radiation pressure on the conical side walls of an electromagnetically resonant truncated conical cavity goes against everything we know from Maxwell's equations. It goes against experimental facts. It goes against calculations from Finite Difference, Finite Element and Boundary Element numerical solutions (FEKO, Meep, COMSOL, etc.) all unequivocally showing that there is radiation pressure on the conical side walls. The complete opposite of the Wright Brothers, who took an experimental approach in conformity with leading knowledge at the time: incorporating the effect of viscosity, and vorticity, from a wind tunnel, to design their wings and propeller. The Wright Brothers concentrated their efforts in preventing flow separation from their wings.
Shawyer, instead of taking a scientific approach followed by leading universities, ignores such theory, experiments, and numerical analysis (FEKO, COMSOL, Meep) and instead of incorporating new aspects of Physics (like gravitation, or Quantum Mechanics, you name it), insists to this date that thrust of the EM Drive can be solely explained purely on the basis of Newton's 3rd law, Maxwell's equations and frame-independent Special Relativity.
Shawyer may be a really great microwave engineer, but his insistence on his explanation has not served his EM Drive well. The EM Drive would have suffered less resistance if he would have dropped the obviously wrong aspects of his explanation (for example that there is no radiation pressure on the side walls) a long time ago and would have concentrated instead in improving the EM Drive engineering and saying "hey it seems to work, but I am not 100% sure why" and would have solicited the advice of leading scientists and engineers on what may be the reason why it may produce a force (if it does produce a force).
Most successful inventors (Wright Brothers, Edison, Ford...) did not become successful by championing wrong theories. They became successful instead by making their inventions a practical reality. There is still time for Shawyer to do this: to drop the wrong aspects of his theory and to focus, concentrate instead in making his device a practical engineering device for space propulsion.
I think the issue is, without "some" theory, he might be unable to get a patent. So he needs a mantra and he has to stick to it because it's in the patent. Maybe? -
#1781 by Rodal on 18 Oct, 2016 18:34
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There is no need to have a theory to be able to patent an invention.
I think the issue is, without "some" theory, he might be unable to get a patent. So he needs a mantra and he has to stick to it because it's in the patent. Maybe?
I think that Shawyer's "need for theory" may be due to the editors at journals like New Scientist, and investors, that were asking for a theoretical explanation, and perhaps the need of UK government officials to justify funding SPR Ltd. efforts.
First of all there is no effective way to protect an idea, aside from trade secrets (which means telling no one and keeping it ... secret). Copyrights protect expression and patents protects inventions, and neither protect ideas. And it is a basic tenet of patent law that scientific laws (and hence scientific theories) cannot be patented, since they are considered to be part of Nature.
Thus Newton, Maxwell or Einstein could not have patented their theories. What they could do was to invent devices that would use their knowledge to come up with inventions that nobody else though of. Einstein got some patents for a refrigerator. Edison got thousands of patents, and did not try to argue against Maxwell or Hertz, instead Edison like, Ford and the Wright Brothers concentrated on ... their inventions. -
#1782 by as58 on 18 Oct, 2016 18:43
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1) Lord Kelvin said that flying machines were impossible because he based his opinion on air as a perfect fluid medium devoid of viscosity. The Wright Brothers took into account fluid viscosity by performing experiments in a wind tunnel. The experimental approach by the Wright Brothers was scientific and in accord with leading fluid mechanics experts at the time (for example Prandtl, Von Mises and Von Karman).
Sorry to go off topic, but... Did Kelvin ever analyse the question of flight seriously? It's always been my understanding that his comments about flight were off-the-cuff; he was, especially in his older years, no stranger to making rash comments. Besides, as far as I know, his often repeated 'heavier than air flying machines are impossible' comment may be apocryphal, all fully sourced comments refer to impossibility of practical and safe flight. -
#1783 by Rodal on 18 Oct, 2016 18:44
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1) Lord Kelvin said that flying machines were impossible because he based his opinion on air as a perfect fluid medium devoid of viscosity. The Wright Brothers took into account fluid viscosity by performing experiments in a wind tunnel. The experimental approach by the Wright Brothers was scientific and in accord with leading fluid mechanics experts at the time (for example Prandtl, Von Mises and Von Karman).
Sorry to go off topic, but... Did Kelvin ever analyse the question of flight seriously? It's always been my understanding that his comments about flight were off-the-cuff; he was, especially in his older years, no stranger to making rash comments. Besides, as far as I know, his often repeated 'heavier than air flying machines are impossible' comment may be apocryphal, all fully sourced comments refer to impossibility of practical and safe flight.
Yeah, I agree, he was old (died in 1907) and to be rigorous, Lord Kelvin was mainly objecting to whether it would be possible to be able to control the flight path of a heavier than air machine. One of the main inventions of the Wright Brothers was the invention of aerodynamic devices to enable a controlled flight.
But it is also fair to say that Lord Kelvin had not developed a theory of viscous flow for wings like Prandtl, and did not have the knowledge of wind tunnels.
Let's don't forget about the Russians, too. Tsiolkovsky developed one of the first wind tunnels in 1896, 11 years before Lord Kelvin died.
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#1784 by Bob012345 on 18 Oct, 2016 18:56
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1) Lord Kelvin said that flying machines were impossible because he based his opinion on air as a perfect fluid medium devoid of viscosity. The Wright Brothers took into account fluid viscosity by performing experiments in a wind tunnel. The experimental approach by the Wright Brothers was scientific and in accord with leading fluid mechanics experts at the time (for example Prandtl, Von Mises and Von Karman).
Sorry to go off topic, but... Did Kelvin ever analyse the question of flight seriously? It's always been my understanding that his comments about flight were off-the-cuff; he was, especially in his older years, no stranger to making rash comments. Besides, as far as I know, his often repeated 'heavier than air flying machines are impossible' comment may be apocryphal, all fully sourced comments refer to impossibility of practical and safe flight.
Yeah, I agree, he was old and to be rigorous, Lord Kelvin was mainly objecting to whether it would be possible to be able to control the flight path of a heavier than air machine. One of the main inventions of the Wright Brothers was the invention of aerodynamic devices to enable a controlled flight.
But it is also fair to say that Lord Kelvin had not developed a theory of viscous flow for wings like Prandtl, and did not have the knowledge of wind tunnels.
There are several high profile scientific public figures that give off the cuff pronouncements on topics that come up such as the EmDrive and other new concepts such as BlackLight which NASA actually tested as a new type of propulsion yet was forced to disassociate from because of controversy. I think it slows down progress. -
#1785 by as58 on 18 Oct, 2016 19:10
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There are several high profile scientific public figures that give off the cuff pronouncements on topics that come up such as the EmDrive and other new concepts such as BlackLight which NASA actually tested as a new type of propulsion yet was forced to disassociate from because of controversy. I think it slows down progress.
Not nearly as much as an obligation to test and take seriously every 'unorthodox' idea would. And no, I don't think BlackLight deserves serious consideration. -
#1786 by wicoe on 18 Oct, 2016 19:16
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There are several high profile scientific public figures that give off the cuff pronouncements on topics that come up such as the EmDrive and other new concepts such as BlackLight which NASA actually tested as a new type of propulsion yet was forced to disassociate from because of controversy. I think it slows down progress.
I doubt that progress can be made by blindly wasting effort and resources on testing all "exotic" ideas that are out there... there has to be at least some direction. I've heard some people say, "but what if it works, the benefits will be enormous!!"... but the same is true for all sorts of perpetual motion and free energy devices, but you wouldn't suggest that they all should be rigorously tested, or would you? -
#1787 by knowles2 on 18 Oct, 2016 19:26
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When you have got multiple teams reporting thrust then it time to put a bit of effort and money into investigating the device seriously.There are several high profile scientific public figures that give off the cuff pronouncements on topics that come up such as the EmDrive and other new concepts such as BlackLight which NASA actually tested as a new type of propulsion yet was forced to disassociate from because of controversy. I think it slows down progress.
I doubt that progress can be made by blindly wasting effort and resources on testing all "exotic" ideas that are out there... there has to be at least some direction. I've heard some people say, "but what if it works, the benefits will be enormous!!"... but the same is true for all sorts of perpetual motion and free energy devices, but you wouldn't suggest that they all should be rigorously tested, or would you? -
#1788 by Bob012345 on 18 Oct, 2016 19:32
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There are several high profile scientific public figures that give off the cuff pronouncements on topics that come up such as the EmDrive and other new concepts such as BlackLight which NASA actually tested as a new type of propulsion yet was forced to disassociate from because of controversy. I think it slows down progress.
Not nearly as much as an obligation to test and take seriously every 'unorthodox' idea would. And no, I don't think BlackLight deserves serious consideration.
That's too bad because it would literally be the perfect power source for EmDrive at kilowatts per Kg. for the device and very small amounts (~3.3 liters per MWhr) of fuel for local space operations. Enough power to do both heavy lifting and cooling without tons of liquid hydrogen. -
#1789 by wicoe on 18 Oct, 2016 19:38
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When you have got multiple teams reporting thrust then it time to put a bit of effort and money into investigating the device seriously.
I agree, but only if there is at least some consistency among these reports... at least the same direction of thrust? Having said all that, I'm really looking forward to the NASA paper in December... -
#1790 by Bob012345 on 18 Oct, 2016 19:39
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There are several high profile scientific public figures that give off the cuff pronouncements on topics that come up such as the EmDrive and other new concepts such as BlackLight which NASA actually tested as a new type of propulsion yet was forced to disassociate from because of controversy. I think it slows down progress.
I doubt that progress can be made by blindly wasting effort and resources on testing all "exotic" ideas that are out there... there has to be at least some direction. I've heard some people say, "but what if it works, the benefits will be enormous!!"... but the same is true for all sorts of perpetual motion and free energy devices, but you wouldn't suggest that they all should be rigorously tested, or would you?
I don't blindly put my enthusiasm into anything. I think a lot about things first. Problem is that very good ideas that have solid evidence are routinely discounted and that makes progress a crawl. EmDrive is actually not as bad off as some ideas at getting traction as it does seem to be advancing. Skepticism is good but Skeptimentalism is bad. -
#1791 by Bob012345 on 18 Oct, 2016 19:41
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When you have got multiple teams reporting thrust then it time to put a bit of effort and money into investigating the device seriously.
I agree, but only if there is at least some consistency among these reports... at least the same direction of thrust? Having said all that, I'm really looking forward to the NASA paper in December...
But I thought it's known that different conditions can change the direction so you can't just assume all setups are the same or should produce the same results. -
#1792 by Bob012345 on 18 Oct, 2016 19:43
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1) Lord Kelvin said that flying machines were impossible because he based his opinion on air as a perfect fluid medium devoid of viscosity. The Wright Brothers took into account fluid viscosity by performing experiments in a wind tunnel. The experimental approach by the Wright Brothers was scientific and in accord with leading fluid mechanics experts at the time (for example Prandtl, Von Mises and Von Karman).
Sorry to go off topic, but... Did Kelvin ever analyse the question of flight seriously? It's always been my understanding that his comments about flight were off-the-cuff; he was, especially in his older years, no stranger to making rash comments. Besides, as far as I know, his often repeated 'heavier than air flying machines are impossible' comment may be apocryphal, all fully sourced comments refer to impossibility of practical and safe flight.
Yeah, I agree, he was old (died in 1907) and to be rigorous, Lord Kelvin was mainly objecting to whether it would be possible to be able to control the flight path of a heavier than air machine. One of the main inventions of the Wright Brothers was the invention of aerodynamic devices to enable a controlled flight.
But it is also fair to say that Lord Kelvin had not developed a theory of viscous flow for wings like Prandtl, and did not have the knowledge of wind tunnels.
Let's don't forget about the Russians, too. Tsiolkovsky developed one of the first wind tunnels in 1896, 11 years before Lord Kelvin died.
He should have realized like the Wright's that birds are both heavier than air and know how to control flight. -
#1793 by SeeShells on 18 Oct, 2016 20:17
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Good question and I'll try to answer very simply for basically it's not hard.And you can’t have evanescent waves in a superconductor, right? So maybe that helps explain Shaywer’s superconducting end plate?
No there is a evanescent part of a wave function acting on a superconductive wall.
https://en.wikipedia.org/wiki/London_penetration_depth
You're correct and that may not be a bad thing. http://pubs.acs.org/doi/abs/10.1021/acs.jpclett.6b00119
Where some of my current reading and research is going looking into the drive's ability to decay and extract the build up of energy. Using the energy that exists from the build of a high Q TE013 cavity and then forcibly decaying that energy into decaying evanescent wave actions.
In simple terms I'm thinking of the EMDrive or even the Cannea device as a photon momentum and force extractor using evanescent decaying waves. Evanescent waves that extract forces at levels greater than the standard photon rocket or light sails. The key I believe is evanescent waves which are virtual photons carrying extraordinary momentum and force that that transfer the force and momentum to the EMDrive and then vanish. So it's just not the reflected energy transfer of a bouncing photon and re-transmission of a lower shifted frequency photon, it consists of all the vector functions and extraordinary forces of the photon in a evanescent wave.
My Very Best,
Shell
I'm trying to understand what you were meaning concerning evanescent waves. Were you suggesting a decaying magnetic field outside the device? In simple classical terms, could a decaying or any magnetic field outside the device also interact with currents on the device to provide a net force on the device? And could such a field be created by the device yet also become sufficiently detached such as to be considered a free field in space the device could interact with? In other words, could you have your cake and eat it too?
For this to potentially work and not violate Mother Nature (she abhors being violated) you must think of what processes can permeate the closed cavity and what energies can escape. For if I have a perfectly enclosed box, Mother Nature (Maxwell too) says nothing I do in the box will have an effect outside the box. But it's not a perfect box, is it?
Gravity exists inside and outside the box and can freely be felt inside, as gravity inside can be felt outside. If I took a tinny black hole and put it into the box and you put your hand on the box... you would know it's a black hole you were close too. So this means gravitational effects produced in the box can be seen and acted on outside the box.
Spacetime is inside and outside, somehow warp it inside the box and it's felt outside.
Some particles also share space inside and outside.
Magnetic fields generated in the copper walls from induced flowing currents create small fields outside the box.
Evanescent wave actions can also collapse inside the box past cutoff points and close to the antenna(s) produce energy that could escape.
This very short list of physics and Quantum actions comprise subjects that honestly we know just enough about to get us into trouble.
Gravity
Spacetime
Magnetic Fields
Some Particles
Evanescent Waves (Virtual Particles should be here as well)
Which one do you think is causing this anomaly of thrusts?
Best,
Shell -
#1794 by rq3 on 18 Oct, 2016 21:31
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Good question and I'll try to answer very simply for basically it's not hard.And you can’t have evanescent waves in a superconductor, right? So maybe that helps explain Shaywer’s superconducting end plate?
No there is a evanescent part of a wave function acting on a superconductive wall.
https://en.wikipedia.org/wiki/London_penetration_depth
You're correct and that may not be a bad thing. http://pubs.acs.org/doi/abs/10.1021/acs.jpclett.6b00119
Where some of my current reading and research is going looking into the drive's ability to decay and extract the build up of energy. Using the energy that exists from the build of a high Q TE013 cavity and then forcibly decaying that energy into decaying evanescent wave actions.
In simple terms I'm thinking of the EMDrive or even the Cannea device as a photon momentum and force extractor using evanescent decaying waves. Evanescent waves that extract forces at levels greater than the standard photon rocket or light sails. The key I believe is evanescent waves which are virtual photons carrying extraordinary momentum and force that that transfer the force and momentum to the EMDrive and then vanish. So it's just not the reflected energy transfer of a bouncing photon and re-transmission of a lower shifted frequency photon, it consists of all the vector functions and extraordinary forces of the photon in a evanescent wave.
My Very Best,
Shell
I'm trying to understand what you were meaning concerning evanescent waves. Were you suggesting a decaying magnetic field outside the device? In simple classical terms, could a decaying or any magnetic field outside the device also interact with currents on the device to provide a net force on the device? And could such a field be created by the device yet also become sufficiently detached such as to be considered a free field in space the device could interact with? In other words, could you have your cake and eat it too?
For this to potentially work and not violate Mother Nature (she abhors being violated) you must think of what processes can permeate the closed cavity and what energies can escape. For if I have a perfectly enclosed box, Mother Nature (Maxwell too) says nothing I do in the box will have an effect outside the box. But it's not a perfect box, is it?
Gravity exists inside and outside the box and can freely be felt inside, as gravity inside can be felt outside. If I took a tinny black hole and put it into the box and you put your hand on the box... you would know it's a black hole you were close too. So this means gravitational effects produced in the box can be seen and acted on outside the box.
Spacetime is inside and outside, somehow warp it inside the box and it's felt outside.
Some particles also share space inside and outside.
Magnetic fields generated in the copper walls from induced flowing currents create small fields outside the box.
Evanescent wave actions can also collapse inside the box past cutoff points and close to the antenna(s) produce energy that could escape.
This very short list of physics and Quantum actions comprise subjects that honestly we know just enough about to get us into trouble.
Gravity
Spacetime
Magnetic Fields
Some Particles
Evanescent Waves (Virtual Particles should be here as well)
Which one do you think is causing this anomaly of thrusts?
Best,
Shell
Here's a nasty thought, only because it puts a huge burden on experimenters and hasn't been controlled for in any experiment I am aware of. One field that CAN somewhat freely transmit from the constraints of the Emdrive frustrum to the "outside world" is the magnetic field. The extensive discussions regarding TE and TM mode shapes may be illustrative, or not?
What if the propagating field within the frustum, alternatively expanding and collapsing, extending and retracting, was generating a "jellyfish" like magnetic field which interacts with the surrounding (earth's) field? Thrust results would be hugely dependant upon the internal frustum mode, the orientation of the frustum to the earth, and the phase of the selected mode. Phase reversal would result in thrust reversal, like the inversion of speech in a single side-band radio when the local oscillator is on the "wrong" side of the DC product. IF this is possible, the Emdrive would be a useful space drive, IF it were immersed in a magnetic field. The weaker the external field, the less effective the thrust.
There would be multiple "anti-Crazy Eddy" points during an Emdrive voyage, where the local magnetic field was nullified due to interaction between external fields. The hypothetical Emdrive "pilot" would have to constantly correct the thrust vector to optimize for the external field environment.
The reason that this effect may be observable with a microwave frustum rather than, say, a conical solenoid, is that the frustum allows control of mode (TE, TM, phase). Optical wavelengths and solenoids do not (easily), so the "effect" hasn't been observed. Just an odd thought. -
#1795 by WarpTech on 18 Oct, 2016 21:42
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...
Good question and I'll try to answer very simply for basically it's not hard.
For this to potentially work and not violate Mother Nature (she abhors being violated) you must think of what processes can permeate the closed cavity and what energies can escape. For if I have a perfectly enclosed box, Mother Nature (Maxwell too) says nothing I do in the box will have an effect outside the box. But it's not a perfect box, is it?
Gravity exists inside and outside the box and can freely be felt inside, as gravity inside can be felt outside. If I took a tinny black hole and put it into the box and you put your hand on the box... you would know it's a black hole you were close too. So this means gravitational effects produced in the box can be seen and acted on outside the box.
Spacetime is inside and outside, somehow warp it inside the box and it's felt outside.
Some particles also share space inside and outside.
Magnetic fields generated in the copper walls from induced flowing currents create small fields outside the box.
Evanescent wave actions can also collapse inside the box past cutoff points and close to the antenna(s) produce energy that could escape.
This very short list of physics and Quantum actions comprise subjects that honestly we know just enough about to get us into trouble.
Gravity
Spacetime
Magnetic Fields
Some Particles
Evanescent Waves (Virtual Particles should be here as well)
Which one do you think is causing this anomaly of thrusts?
Best,
Shell
Chi is the (scalar) magnetic flux. It is stored inside as a potential energy, and it leaks from the inside through eddy currents in the copper. Anywhere there are voltage drops, you can have magnetic flux passing through that circuit. This is NOT to say that it makes it to the outside, only that it escaped the inside. It never reaches the outside if it gets trapped and dissipated as heat in the copper.
This equation constitutes a conservation of momentum, and a divergence of the field. REGARDLESS if the flux interacts with anything outside the frustum or not. In other words, interaction outside the box is not necessary if the loss is escaping as heat. What moves the frustum is the change in potential energy, causing an asymmetrical divergence of the flux that shifts the center of mass.
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#1796 by knowles2 on 18 Oct, 2016 21:54
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If that is the case then the drive shouldn't work outside of the earth magnetic field.
Good question and I'll try to answer very simply for basically it's not hard.And you can’t have evanescent waves in a superconductor, right? So maybe that helps explain Shaywer’s superconducting end plate?
No there is a evanescent part of a wave function acting on a superconductive wall.
https://en.wikipedia.org/wiki/London_penetration_depth
You're correct and that may not be a bad thing. http://pubs.acs.org/doi/abs/10.1021/acs.jpclett.6b00119
Where some of my current reading and research is going looking into the drive's ability to decay and extract the build up of energy. Using the energy that exists from the build of a high Q TE013 cavity and then forcibly decaying that energy into decaying evanescent wave actions.
In simple terms I'm thinking of the EMDrive or even the Cannea device as a photon momentum and force extractor using evanescent decaying waves. Evanescent waves that extract forces at levels greater than the standard photon rocket or light sails. The key I believe is evanescent waves which are virtual photons carrying extraordinary momentum and force that that transfer the force and momentum to the EMDrive and then vanish. So it's just not the reflected energy transfer of a bouncing photon and re-transmission of a lower shifted frequency photon, it consists of all the vector functions and extraordinary forces of the photon in a evanescent wave.
My Very Best,
Shell
I'm trying to understand what you were meaning concerning evanescent waves. Were you suggesting a decaying magnetic field outside the device? In simple classical terms, could a decaying or any magnetic field outside the device also interact with currents on the device to provide a net force on the device? And could such a field be created by the device yet also become sufficiently detached such as to be considered a free field in space the device could interact with? In other words, could you have your cake and eat it too?
For this to potentially work and not violate Mother Nature (she abhors being violated) you must think of what processes can permeate the closed cavity and what energies can escape. For if I have a perfectly enclosed box, Mother Nature (Maxwell too) says nothing I do in the box will have an effect outside the box. But it's not a perfect box, is it?
Gravity exists inside and outside the box and can freely be felt inside, as gravity inside can be felt outside. If I took a tinny black hole and put it into the box and you put your hand on the box... you would know it's a black hole you were close too. So this means gravitational effects produced in the box can be seen and acted on outside the box.
Spacetime is inside and outside, somehow warp it inside the box and it's felt outside.
Some particles also share space inside and outside.
Magnetic fields generated in the copper walls from induced flowing currents create small fields outside the box.
Evanescent wave actions can also collapse inside the box past cutoff points and close to the antenna(s) produce energy that could escape.
This very short list of physics and Quantum actions comprise subjects that honestly we know just enough about to get us into trouble.
Gravity
Spacetime
Magnetic Fields
Some Particles
Evanescent Waves (Virtual Particles should be here as well)
Which one do you think is causing this anomaly of thrusts?
Best,
Shell
Here's a nasty thought, only because it puts a huge burden on experimenters and hasn't been controlled for in any experiment I am aware of. One field that CAN somewhat freely transmit from the constraints of the Emdrive frustrum to the "outside world" is the magnetic field. The extensive discussions regarding TE and TM mode shapes may be illustrative, or not?
What if the propagating field within the frustum, alternatively expanding and collapsing, extending and retracting, was generating a "jellyfish" like magnetic field which interacts with the surrounding (earth's) field? Thrust results would be hugely dependant upon the internal frustum mode, the orientation of the frustum to the earth, and the phase of the selected mode. Phase reversal would result in thrust reversal, like the inversion of speech in a single side-band radio when the local oscillator is on the "wrong" side of the DC product. IF this is possible, the Emdrive would be a useful space drive, IF it were immersed in a magnetic field. The weaker the external field, the less effective the thrust.
There would be multiple "anti-Crazy Eddy" points during an Emdrive voyage, where the local magnetic field was nullified due to interaction between external fields. The hypothetical Emdrive "pilot" would have to constantly correct the thrust vector to optimize for the external field environment.
The reason that this effect may be observable with a microwave frustum rather than, say, a conical solenoid, is that the frustum allows control of mode (TE, TM, phase). Optical wavelengths and solenoids do not (easily), so the "effect" hasn't been observed. Just an odd thought.
How high up would we have to launch a em drive to be free of the earth magnetic field? -
#1797 by SeeShells on 18 Oct, 2016 22:01
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Yes, we know from tests from EagleWorks actual IR images of the large endplate which was FR2 I think that heat does escape through the modes, we have seen it in rfmwguy's IR of his small endplate as well.
Best,
Shell
Chi is the (scalar) magnetic flux. It is stored inside as a potential energy, and it leaks from the inside through eddy currents in the copper. Anywhere there are voltage drops, you can have magnetic flux passing through that circuit. This is NOT to say that it makes it to the outside, only that it escaped the inside. It never reaches the outside if it gets trapped and dissipated as heat in the copper.
This equation constitutes a conservation of momentum, and a divergence of the field. REGARDLESS if the flux interacts with anything outside the frustum or not. In other words, interaction outside the box is not necessary if the loss is escaping as heat. What moves the frustum is the change in potential energy, causing an asymmetrical divergence of the flux that shifts the center of mass.
Best
Shell
PS: Also we need to consider.
Let us also repeat that the classical, relativistic (stationary) Helmholtz equation for an
electromagnetic wavepacket in a waveguide is known to be formally identical to the quantum, non-relativistic (stationary) Schroedinger equation for a potential barrier(2); so that, for instance, the tunneling of a particle under and along a barrier has been simulated [2, 4,7–11,13] by the traveling of evanescent waves along an undersized waveguide. Therefore, the results of this paper are to be valid also for electromagnetic wave propagation along waveguides with a succession of undersized segments (the “barriers”) and of normal-sized segments. This confirms the results obtained, within the classical realm, directly from Maxwell equations [9, 13], as well as by the known series of “tunneling” experiments performed —till now— with microwaves (see refs. [7] and particularly [8]).
∗ ∗
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#1798 by rq3 on 18 Oct, 2016 22:45
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Quote
If that is the case then the drive shouldn't work outside of the earth magnetic field.
How high up would we have to launch a em drive to be free of the earth magnetic field?
Perhaps you missed the point. The Emdrive may NEED an external magnetic field. Whether it is from the Earth, the Sun, or the Andromeda galaxy is not important. The strength and orientation of the external field may perhaps be critical. Any experimenters willing to include complete Helmholtz coil control as a variable? Any reason to do so? Any reason not to do so? -
#1799 by dustinthewind on 19 Oct, 2016 00:05
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Per Rodal's recent suggestion, I want to make clear that the contents of this post specifically deal only with up to special relativity, and not general relativity, because I am discussing Shawyer's claims. (And a mention of Woodward's paper where he tries to justify the Mach effect without general relativity)
It seems like you don't understand what the terms you are using mean. The fact that light propagates at c in every frame is why you can't define a unique frame that it propagates relative to. A unique frame that it propagates relative to is exactly what the concept of the ether is. Unless you are thinking of a "rest frame" for the light, but that doesn't really make sense (any calculations in that frame involve dividing by 0) and it wouldn't be unique anyway since there are an infinite number of different directions for the frame to be moving in.To me, EM waves occupy a unique frame thus the cavity is always open wrt radiation. Shawyer is probably correct but even if not, they way they use it to undermine the EmDrive rather than look into it is disheartening
The entire motivation for special relativity is that EM waves don't have a special frame. Experiments showing that the ether didn't exist is the original evidence for special relativity (although it was originally motivated theoretically by the apparent frame independence in Maxwell's equations.)
There is zero chance that Shawyer's claims are correct within special relativity. When he makes these claims he immediately discredits himself. What is unfortunate is Shawyer's insistence on repeating claims that to experienced physicists are equivalent to 1+1 = 3. When presented with such a claim, it is completely reasonable to not look into it further.
The fact that light propagates at c as observed in every frame defines a unique frame in my view for light and that has nothing to do with the concept of ether.And exactly how are you so absolutely sure about Shawyer's claims having zero chance of being correct since no one knows exactly how the device works in the first place?
His claims are directly contradictory with each other and with simple physics. For example, as I have been trying to explain to TheTraveller recently, his claims include that a force applied pushing an object to the left will cause it to move to the right. There is a whole list of issues with his claims, you don't even get to that point without first ignoring that some of the claims blatantly break conservation of momentum, while Shawyer claims momentum is conserved and that no new physics is needed.Experienced physicists sometimes are too quick to reject new ideas that don't immediately fit into their comfortable paradigms.
That may be true in some cases, but it is not inappropriate when you look at how bad Shawyer's claims are in this case.
Previously, you had made a post on the CoE discussion, that captures most of the essence of the issue of CoE:...
The biggest problem with Shawyer's claims is that he claims that no new physics is required to explain the emDrive, but to have the properties he claims you would have to have some sort of "propellant" everywhere that you can somehow borrow energy and momentum from like you said.
I agree but when you look at the terms, both the gain in kinetic energy of the ship and the loss in kinetic energy of the propellant can dwarf the chemical energy. In the case of an EmDrive or MET device, I believe the ship borrows from the "propellant" even though we don't know what that exactly is. We do know the momentum of the "propellant" is the same as gained by the ship. And the ship borrows from that so the total energy input is whatever the EmDrive needed to make a constant force over a certain time period yet the kinetic energy gain of the ship as well as the loss of the "propellant" are huge in comparison. There is no violation of CoM or CoE. The apparent violation is comparing the total electrical input to the device with the ships final kinetic energy while ignoring the loss of "propellant" kinetic energy during the trip. To me, it's just like a magic rocket that never runs out of fuel and yet the mass remains constant.
This is also the problem with Woodward's paper that we were discussing. While the Mach effect uses general relativity and has a way out, Woodward was trying to instead tries to argue that energy could be conserved without this. (The original argument he was trying to argue against only applies if it is a complete propellantless system with no external energy source, and he does not appeal to or account for the existence of propellant in his calculations)
I think we can't expect Shawyer to have solved it all himself. What I get from his explanation is that he expects there to have been a back reaction on something such that the cavity accelerates. The only thing there is, is the light, so it seems he is indicating the light is getting the back reaction. Now this may seem heresy but I think he may be somewhat correct. I will have to try and describe this.
Take a distant observer in the universe who observes the CMB. To him there appears to be an absolute frame of reference. In a cavity co-propagating light waves give a frame of reference also and in the universe we have co-propagating light waves. For that distant observer there is some definite frame that qualifies as moving at the speed of light. Anything moving in that frame for it observes the universe as infinitely flat and time is reduced to practically nothing. Describing an observer moving in that frame observing light still moving at the speed of light seems nonsense to me as the rest of the universe would be seriously warped. So it seems there is some absolute frame of reference which may exclude special relativity in that sense. So maybe he is mistaken to be claiming it holds to special relativity.
So here is the point. Light as it is falling into an event horizon of a black hole appears to be moving against a frame of reference that is in motion. It can escape if it is not in the horizon but will be severely red-shifted as if moving to a non-accelerated frame took its toll. Starting at the event horizon the light seems it can never escape as if space it self is going toward the horizon at the speed of light. It almost seems like a frame of reference.
Here is another. Lets consider frame dragging. A rotating object appears to drag space around with it which we detected with gravity probe b for example and is much larger for objects like rapidly rotating black holes. In such an instance the speed of light around the object in one direction is faster than the speed of light the other direction. This is a lot like a frame of reference also.
Inducing a gravitational effect seems to cause a change in the reference frame for light which can cause frequency shifting. So is Shawyer wrong to say that the back reaction might be on the light? I don't think it is the complete picture, but I wouldn't say he is completely wrong. No force on the side walls of a cavity does worry me, though that is not to say with some conversation he wouldn't agree that there should be radiation force on the side walls.
Of course I would like to see more concrete evidence that it is actually producing thrust even in vacuum. There seems to be more and more evidence in support. Lets hope time will tell.
