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#60 by Rodal on 27 Dec, 2015 13:04
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In the USA there is venture capital to fund innovative ideas, but of course venture capitalists are not going to easily depart with their money, they of course will demand some kind of verification. You will be competing with many other inventors that want to get the little amount of venture capital money available (space propulsion is much less attractive to venture capitalists than other fields like biotechnology).The first step is to look for missing "hidden momentum" that nullifies the idea. The next step, or at the same time, is to think of what an experiment would look like: how would you actually go about building such an experiment. Can you think of how to do such an experiment at home, with a minimum budget? For example, see the different Do It Yourself experiments in the EM Drive threads (of course you would need to have experience in this area so as to be SAFE, as we don't want you to get electrocuted !) Or, do you have access to a University laboratory?...Hey, Rodal. Are you working in NASA?
By "we", I meant "you and I, and whoever else that reads this thread that is interested in whether your idea is possible".
"We have to find the missing", Who is that "We"?
I am comparing electromagnetism with Newton's theory, not comparing electromagnetism with other modern physics theory.
The "hidden momentum" should be in vacuum.
To me the first step is trying to prove your theory wrong, by finding hidden momentum.
The immediate next step is to do an experiment and see what mother Nature has to say about it
I am not finding.
If you are not in NASA, then where can you find resource to do experiment?
The process of thinking about how would you actually build your invention with actual physical parts will be helpful in uncovering problems with the invention and show why it may not be possible for it to be better than a photon rocket. -
#61 by ZhixianLin on 28 Dec, 2015 00:09
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In the USA there is venture capital to fund innovative ideas, but of course venture capitalists are not going to easily depart with their money, they of course will demand some kind of verification. You will be competing with many other inventors that want to get the little amount of venture capital money available (space propulsion is much less attractive to venture capitalists than other fields like biotechnology).The first step is to look for missing "hidden momentum" that nullifies the idea. The next step, or at the same time, is to think of what an experiment would look like: how would you actually go about building such an experiment. Can you think of how to do such an experiment at home, with a minimum budget? For example, see the different Do It Yourself experiments in the EM Drive threads (of course you would need to have experience in this area so as to be SAFE, as we don't want you to get electrocuted !) Or, do you have access to a University laboratory?...Hey, Rodal. Are you working in NASA?
By "we", I meant "you and I, and whoever else that reads this thread that is interested in whether your idea is possible".
"We have to find the missing", Who is that "We"?
I am comparing electromagnetism with Newton's theory, not comparing electromagnetism with other modern physics theory.
The "hidden momentum" should be in vacuum.
To me the first step is trying to prove your theory wrong, by finding hidden momentum.
The immediate next step is to do an experiment and see what mother Nature has to say about it
I am not finding.
If you are not in NASA, then where can you find resource to do experiment?
The process of thinking about how would you actually build your invention with actual physical parts will be helpful in uncovering problems with the invention and show why it may not be possible for it to be better than a photon rocket.
No, I can't access any laboratory and I am nobody. I don't even know how to do a reliable simulation for my design. Can you do a simulation for it? -
#62 by Rodal on 29 Dec, 2015 01:12
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You are somebody: you proved this by taking the step to report your idea in this great forum (NSF) and get a number of responses. You just have to follow it up by thinking of how you would go about implementing your idea with actual components: this will:
No, I can't access any laboratory and I am nobody. I don't even know how to do a reliable simulation for my design. Can you do a simulation for it?
1) Help you find any reasons why your idea cannot be reduced to practice. If you find an error or you find you cannot reduce it to practice, then modify your idea or come up with a new one.
2) Enable you to write a patent (if in the process of reducing your idea to practice you create something that is not already known "to those skilled in the aerospace art").
3) Enable you to perhaps conduct your own Do It Yourself experiment (if you can safely do so) or get others to conduct their safe experiments.
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#63 by ZhixianLin on 29 Dec, 2015 02:12
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You are somebody: you proved this by taking the step to report your idea in this great forum (NSF) and get a number of responses. You just have to follow it up by thinking of how you would go about implementing your idea with actual components: this will:
No, I can't access any laboratory and I am nobody. I don't even know how to do a reliable simulation for my design. Can you do a simulation for it?
1) Help you find any reasons why your idea cannot be reduced to practice. If you find an error or you find you cannot reduce it to practice, then modify your idea or come up with a new one.
2) Enable you to write a patent (if in the process of reducing your idea to practice you create something that is not already known "to those skilled in the aerospace art").
3) Enable you to perhaps conduct your own Do It Yourself experiment (if you can safely do so) or get others to conduct their safe experiments.
Thanks, Rodal!
I think we don't have to waste time on finding the "hidden momentum", the tensor is the "hidden momentum". We just need to do a simulation, that is enough. Only a few people will consider such a crazy design, NASA may never come here. I am not sure if I should write a patent, it maybe just waste money on patent. Doing experiment is important, but I think we need a simulation before it. -
#64 by birchoff on 03 Jan, 2016 06:46
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There was no concept of the Supefluid vacuum at the time of Newton. When bringing up Newton's law it is better to be done consistently, with today's knowledge and not with Newton's knowledge (Cauchy extended to defomable media Newton's concept). During Maxwell's time (after Newton) the medium for electromagnetism was thought to be the aether, which was conceived as a material medium having a finite modulus of elasticity (it was NOT considered to be infinitely rigid)....
I think the equation 4-1 also works under non-Continuum Mechanics, so the equation 4-4 should also be non-Continuum Mechanics. I am comparing them all under non-Continuum Mechanics. The comparison is in order to prove that momentum can be not conserved. If I change the equation 4-4 to Continuum Mechanics form, then how can I prove momentum can be not conserved?
And if my design works, then finally we have to acknowledge that momentum can be not conserved. So why don't we just declare that momentum can be not conserved first?
Equation 4-1 and 4-2 are Continuum equations, because they are electromagnetic (Maxwell) equations for continuum fields (the E and B fields, and the stress tensor T are defined for a continua). Therefore, the generalized form of Newton's law for deformable continuum media should be used instead of the simplified version assuming infinitely rigid non-deformable objects.
As to your final question <<And if my design works, then finally we have to acknowledge that momentum can be not conserved. So why don't we just declare that momentum can be not conserved first?>> that is quite a conundrum isn't it?
So at the moment I am leaning that your design is too good to work, that there must be "hidden momentum" to cancel it, and we just have to find it
In fact, there is no non-Continuum Mechanics for electromagnetism. Because vacuum is every where in our universe, you can't find a place without vacuum. For Newton's Continuum Mechanics, it needs water, air or some other continuum. But in vacuum, there is no continuum for Newton's Continuum Mechanics. So how can I use Newton's Continuum Mechanics in vacuum? In vacuum, we should just use Newton's second law.
Just because in vacuum electromagnetism must be Continuum Mechanics, but in vacuum there can not be Newton's Continuum Mechanics, and that's why electromagnetism is different with Newton's law.
<< there is no non-Continuum Mechanics for electromagnetism>>
This statement is a double negative. Double-negatives implies a positive statement: in this case you are stating that since there is not any non-Continuum Mechanics for electromagnetism, that you are admitting the truth: that Maxwell's Electromagnetism is a Continuum theory.
But then, you appear to go back, as you state
<< So how can I use Newton's Continuum Mechanics in vacuum? In vacuum, we should just use Newton's second law>>
1) The equations you are using for Electromagnetism 4-1 and 4-2 are Continuum equations
2) Maxwell conceived those equations as being contained in a continuous aether (a medium with finite modulus of elasticity, NOT with infinite modulus of elasticity)
3) Einstein showed that there was no aether. He eventually replaced the aether with a continuous gravitational field that permeates the whole Universe. The theory of General Relativity is a CONTINUUM theory as well
4) The Quantum Vacuum is continuous
5) You have to use Cauchy's generalization of Newton's law, that contains the stress gradient, because the Newton's law you are using in your paper is a simplification, that neglects deformation of the continuum. The Newton's law that you are using assumed INFINITE modulus of elasticity. There is no medium in the Universe with an infinite modulus of elasticity. The Newton's law F = ma you are using is a simplification used in elementary classes, that completely neglects the stress gradient. The stress gradient is not zero in general, because all mediums are deformable. You must use the stress gradient in your discussion of Newton's law.
When you discuss Newton's law without including the stress gradient you are discussing an unreal medium that has no stress gradient and which is not deformable. Concerning the Quantum Vacuum see Paul Dirac's paper.
What is the continuum(medium) in vacuum for Newton's law?
Newton's law think vacuum is empty, so Newton's law can not use vacuum as continuum. But electromagnetism think vacuum is not empty, so electromagnetism can use vacuum as continuum.
<< there is no non-Continuum Mechanics for electromagnetism>>
I mean electromagnetism is always Continuum Mechanics theory, because vacuum is every where in the universe(even in water or air).
In vacuum, Newton's law has no continuum, but electromagnetism has(the vacuum). That's why in vacuum Newton's law use the simplified version equation, but electromagnetism equation use Continuum Mechanics version. It is obviously that my drive is running in vacuum, you can't ignore that.
http://arxiv.org/abs/1501.06763
https://en.wikipedia.org/wiki/Superfluid_vacuum_theory
https://en.wikipedia.org/wiki/Dirac_sea
http://phys.org/news/2011-08-dark-illusion-quantum-vacuum.html
http://resonance.is/news/quantum-weirdness-replaced-by-classical-fluid-dynamics/
Sorry, Rodal. I tired of explanation. Is the Superfluid Vacuum a Newton's theory? When did Newton say that vacuum is superfluid?
The quantum vacuum as a fluid was first discussed by Nobel Prize winner Paul Dirac, as far as I know.
The most up-to-date theory on the vacuum as a fluid is the Superfluid vacuum theory. Using the Superfluid vacuum theory as a foundation seems better to me than stating <<EWEFFT looks like a violation of Newton's Law, but it does not violate any principle of electromagnetism.>>.
In any case, as stated before it seems to me that your drive performance is too good to be believed , and probably there is hidden momentum (not taken into account in the formulation) that would prevent it.
We have to find the missing "hidden momentum" that would make this (better than a photon rocket) performance impossible.
If we find the missing "hidden momentum" in your drive discussion, this discussion about the proper way to discuss Newton's law would become unnecessary and pointless.
Just want to make sure I am following the discussion correctly.
Maxwells equations for Electromagnetism take as an assumption that EM waves/photons must propagate through some continuous "aether" which has a finite modulus of elasticity.
Fast forward to modern times
Are we assuming the aether which is assumed in Maxwells work would be considered to be dirac's quantum vaccum sea? If so given all of the valid observations we have for Maxwell's equations does that mean the quantum vaccum sea must also be continuous with a finite modulous of elasticity? -
#65 by Rodal on 03 Jan, 2016 14:27
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Just want to make sure I am following the discussion correctly.
Maxwells equations for Electromagnetism take as an assumption that EM waves/photons must propagate through some continuous "aether" which has a finite modulus of elasticity.
Fast forward to modern times
Are we assuming the aether which is assumed in Maxwells work would be considered to be dirac's quantum vaccum sea? If so given all of the valid observations we have for Maxwell's equations does that mean the quantum vaccum sea must also be continuous with a finite modulous of elasticity?
(Disclaimer and explanation: Zhixian Lin has not invoked any theory of the superfluid vacuum for his proposed concept. I advanced the idea of a superfluid vacuum in one of our exchanges.)
Answer to birchoff's question:
There are several theories of a superfluid vacuum. These theories have a "speed of sound" of the vacuum superfluid equal to (in the simplest theories) or higher than the speed of light.
The speed of sound in the superfluid vacuum can be associated with quasiparticles which are thus phonons: quanta of sound waves. The superfluid vacuum theories thus have "sound waves" in addition to "gravitational waves".
One can think of the speed of sound of the vacuum as being associated with a (very large value) bulk modulus of elasticity (and density) of the superfluid vacuum, but these theories usually discuss the speed of sound (*) of the vacuum in terms of vacuum energy considerations and not specifically in terms of a bulk modulus of elasticity of the vacuum superfluid.
If an external observer could measure the propagation of ‘light’ ("vacuum sound", or other massless low-energy quasiparticles), she would find that the speed of light is coordinate-dependent. Moreover, it is anisotropic: it depends on the direction of propagation with respect to the flow of the superfluid vacuum.
However, an inner observer (inside the superfluid vacuum) always finds that the ‘speed of light’ (the maximum attainable speed for low-energy quasiparticles) is invariant. The inner observer inside the superfluid vacuum cannnot know that this invariance is the result of the flexibility of the clocks of quasiparticles: the slowing down of such a clock (the time dilation). These physical effects experienced by low-energy instruments do not allow the inner observer to measure the ‘ether drift’, i.e. the motion of the superfluid vacuum: the Michelson–Morley-type measurements of the speed of massless quasiparticles in moving ‘ether’ would give a negative result. The low-energy rods and clocks also follow the anisotropy of the vacuum and thus cannot record this anisotropy. As a result, all the inner observers would agree that the speed of light is the fundamental constant.
Wikipedia (https://en.wikipedia.org/wiki/Superfluid_vacuum_theory ) puts it this way:QuoteAn observer who resides inside such vacuum and is capable of creating or measuring the small fluctuations would observe them as relativistic objects - unless their energy and momentum are sufficiently high to make the Lorentz-breaking corrections detectable. If the energies and momenta are below the excitation threshold then the superfluid background behaves like the ideal fluid, therefore, the Michelson–Morley-type experiments would observe no drag force from such aether
and it lists these experiments associated with the superfluid vacuum theories:
ANNIE
Gran Sasso
INO
LHC
SNO
Super-K
Tevatron
NOνA
____________________________________________________
Some superfluid vacuum theories explain Dark Energy and Dark Matter as follows:
• Dark energy = Energy density of superfluid vacuum.
• Dark matter = Density fluctuations of superfluid vacuum.
Dark energy and dark matter in a superfluid universe
Kerson Huang
Physics Department, MIT, Cambridge, USA
Talk given at Dyson's 90th birthday symposium, 26‐29 AUG 2013, NTU, Singapore
http://www.mit.edu/people/kerson/cosmologystuff/Dyson.pdf
________
(*) for example a speed of sound "c" in the superfluid vacuum may be defined by the following expression
c² = (n/m) ∂²U/∂n²
where
U = vacuum energy density as a function of the quasiparticle density
n = quasiparticle number density
m = bare mass of quasiparticle
one may infer from this an equivalent bulk modulus of elasticity of the superfluid vacuum (which follows readily from the fact that the bulk modulus of elasticity for a hyperelastic material is the second derivative of the strain energy density with respect to the volumetric logarithmic strain):
c² = (1/ρ) ∂²U/∂ε²
= Ks / ρ
where
U = strain energy density of the superfluid vacuum
ε = volumetric strain (logarithmic measure)
ρ = mass density of the superfluid vacuum
Ks = inferred bulk modulus of elasticity of the supefluid vacuum
Since the density and the speed of sound of the superfluid vacuum are finite, it readily follows that the bulk modulus of elasticity of the superfluid vacuum is finite. But the physical interpretation is better grasped by the superfluid mathematical description and analysis
Superfluids also have thermal sound waves and hence a so called second sound (a second speed of sound due to entropy/temperature fluctuations instead of pressure/density fluctuations):
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#66 by ZhixianLin on 29 Jan, 2016 00:07
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The name "Electromagnetic Wave Electric Field Force Thruster" is too long. How about a new name "Vacuum Tensor Drive"?
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#67 by ZhixianLin on 29 Jan, 2016 00:10
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Still no one has found the technical error. Is it so difficult?
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#68 by thisdude on 29 Jan, 2016 12:40
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Like a big scale version of putting a negative magnet on a toy car and making a mount for a positive magnet to hang off same car an inch back causing it to move forward but on large scale?
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#69 by ZhixianLin on 29 Jan, 2016 13:16
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Like a big scale version of putting a negative magnet on a toy car and making a mount for a positive magnet to hang off same car an inch back causing it to move forward but on large scale?
Obviously it is not two magnets on the same car. The electric field of electromagnetic wave is passive field, it does not have field source. And because it does not have field source, then there will be no another charge to take the reaction force. So there is only one charge pushed by the electric field of electromagnetic wave. Change the charge to magnet, it is that there is only one magnet pushed by the magnetic field of electromagnetic wave. -
#70 by dustinthewind on 29 Jan, 2016 19:50
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Just want to make sure I am following the discussion correctly.
Maxwells equations for Electromagnetism take as an assumption that EM waves/photons must propagate through some continuous "aether" which has a finite modulus of elasticity.
Fast forward to modern times
Are we assuming the aether which is assumed in Maxwells work would be considered to be dirac's quantum vaccum sea? If so given all of the valid observations we have for Maxwell's equations does that mean the quantum vaccum sea must also be continuous with a finite modulous of elasticity?
Wikipedia (https://en.wikipedia.org/wiki/Superfluid_vacuum_theory ) puts it this way:
...
Thanks for all this information and discussion Rodal and Birchoff. I am extatic to see this link. I should have already found this. -
#71 by meberbs on 30 Jan, 2016 20:14
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Still no one has found the technical error. Is it so difficult?
Yes, solving the equations for electromagnetism is a difficult task. Your paper does not thoroughly address the forces involved, account for radiation from the flat plate, or adequately address the form and source of the incident radiation field.
If the posts here and in other threads have not convinced you that you cannot generate more thrust than a photon rocket without emitting mass, and you want to pursue your idea further, Dr. Rodal has provided some good suggestions on where to go from here. You will have to make the time investment to follow through on it though, since it is not likely someone here will have the time to do it for you. -
#72 by ZhixianLin on 30 Jan, 2016 23:42
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Still no one has found the technical error. Is it so difficult?
Yes, solving the equations for electromagnetism is a difficult task. Your paper does not thoroughly address the forces involved, account for radiation from the flat plate, or adequately address the form and source of the incident radiation field.
If the posts here and in other threads have not convinced you that you cannot generate more thrust than a photon rocket without emitting mass, and you want to pursue your idea further, Dr. Rodal has provided some good suggestions on where to go from here. You will have to make the time investment to follow through on it though, since it is not likely someone here will have the time to do it for you.
So it means that the technical error is not so obviously, even you can not point out it easily. Just use the Newton's law of conservation of momentum is easy, but that can not provide any technical details. And I think if the design works, obviously it will change the world completely. So it is definitely worth to do detailed analysis, even it is difficult. -
#73 by meberbs on 31 Jan, 2016 21:01
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So it means that the technical error is not so obviously, even you can not point out it easily. Just use the Newton's law of conservation of momentum is easy, but that can not provide any technical details. And I think if the design works, obviously it will change the world completely. So it is definitely worth to do detailed analysis, even it is difficult.
No, it means the error is that your original analysis is incomplete. I easily pointed out areas where it is incomplete.
The general case of Maxwell's equations including special relativity is known to conserve momentum with the only special piece being photons which are massless particles that have momentum proportional to their energy. This is enough to be certain that the design won't work as claimed if you complete the analysis. Unless I feel like practicing solving complicated equations, I have no reason to do the math to complete your analysis for you.
As I already said, you can take steps to complete your analysis if you think that there is any reason to do so, but I (and others who understand that EM theory conserves momentum) have no reason to do so ourselves. -
#74 by ZhixianLin on 31 Jan, 2016 23:55
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So it means that the technical error is not so obviously, even you can not point out it easily. Just use the Newton's law of conservation of momentum is easy, but that can not provide any technical details. And I think if the design works, obviously it will change the world completely. So it is definitely worth to do detailed analysis, even it is difficult.
No, it means the error is that your original analysis is incomplete. I easily pointed out areas where it is incomplete.
The general case of Maxwell's equations including special relativity is known to conserve momentum with the only special piece being photons which are massless particles that have momentum proportional to their energy. This is enough to be certain that the design won't work as claimed if you complete the analysis. Unless I feel like practicing solving complicated equations, I have no reason to do the math to complete your analysis for you.
As I already said, you can take steps to complete your analysis if you think that there is any reason to do so, but I (and others who understand that EM theory conserves momentum) have no reason to do so ourselves.
So you think EmDrive is also impossible?
I have provided a simple version in a previous post, it is not complicated:
"Just imagine, if we do not use the metal panel but just put a still charged object on the electromagnetic wave propagation path. And we know in half a cycle the electric field force direction of electromagnetic wave will not change, so we can calculate the average electric field force on the object in half a cycle. Because the initial state of the object is still, so the energy of the object will all come from the electromagnetic wave. After you calculated the average electric field force, then you can compare it with radiation pressure. And you will see that electric field force has much higher efficiency than radiation pressure in using the energy electromagnetic wave."
If you wish, you can check the simple version yourself, not for me. -
#75 by meberbs on 02 Feb, 2016 01:14
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So you think EmDrive is also impossible?
Unless you bring in new physics, the EM drive cannot work. This has been thoroughly covered on the EMdrive thread. (Note that there are some difficulties defining momentum conservation in general relativity, but many would still consider finding a loophole in GR for propellant less thrust new physics).I have provided a simple version in a previous post, it is not complicated:
"Just imagine, if we do not use the metal panel but just put a still charged object on the electromagnetic wave propagation path. And we know in half a cycle the electric field force direction of electromagnetic wave will not change, so we can calculate the average electric field force on the object in half a cycle. Because the initial state of the object is still, so the energy of the object will all come from the electromagnetic wave. After you calculated the average electric field force, then you can compare it with radiation pressure. And you will see that electric field force has much higher efficiency than radiation pressure in using the energy electromagnetic wave."
If you wish, you can check the simple version yourself, not for me.
That example may be simpler than your design, but it is not simple.
I found 3 good papers covering various aspects of this problem.
This paper calculates the oscillations the occur in the charged particle when a realistic wavepacket passes by. This results in re-radiation due to the accelerations and changes the spectrum of frequencies present. Their main conclusions are correct (changes to radiation frequency and the fact that the magnetic field does have a significant role in the applied force) However there is an issue due to them ignoring some of the (relativistic) forces. Considering the claim that the particle ends up at rest despite some EM energy now travelling in different directions makes it clear that momentum must not have been conserved.
This paper simplifies the analysis by using a non-physical EM wave of infinite extent, but this helps them to calculate the full relativistic equations of motion. The final result matches the oscillations described by the other paper, but including the relativistic effects and radiation damping results in the particle accelerating in the direction of the Poyting vector, balancing the momentum issue I pointed out with the previous paper.
Note that the momentum related to the oscillations (and in particular the momentum not in the same direction as the Poynting vector of the incident wave) would be balanced by the instantaneous asymmetry in the fields produced and radiated by the charge. These fields would balance the momentum at all times if you bothered to calculate the EM momentum. (I do not intend to, working out all of the math would take more time than I feel like spending on this.)
I am just linking this paper for fun, since it shows how quantum mechanics complicates things. I do not believe it uses relativistic quantum mechanics (also called QED - Quantum ElectroDynamics).
Also, looking through these papers reminded me of another specific issue with your setup. The electrons travel slower than light, so the balancing charge to the charge on your plate will have to be nearby. Its distance will be less than one half-wavelength of the wave, so the opposite charge will almost certainly be close enough to be affected by the incident wave. -
#76 by ZhixianLin on 02 Feb, 2016 02:20
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So you think EmDrive is also impossible?
Unless you bring in new physics, the EM drive cannot work. This has been thoroughly covered on the EMdrive thread. (Note that there are some difficulties defining momentum conservation in general relativity, but many would still consider finding a loophole in GR for propellant less thrust new physics).I have provided a simple version in a previous post, it is not complicated:
"Just imagine, if we do not use the metal panel but just put a still charged object on the electromagnetic wave propagation path. And we know in half a cycle the electric field force direction of electromagnetic wave will not change, so we can calculate the average electric field force on the object in half a cycle. Because the initial state of the object is still, so the energy of the object will all come from the electromagnetic wave. After you calculated the average electric field force, then you can compare it with radiation pressure. And you will see that electric field force has much higher efficiency than radiation pressure in using the energy electromagnetic wave."
If you wish, you can check the simple version yourself, not for me.
That example may be simpler than your design, but it is not simple.
I found 3 good papers covering various aspects of this problem.
This paper calculates the oscillations the occur in the charged particle when a realistic wavepacket passes by. This results in re-radiation due to the accelerations and changes the spectrum of frequencies present. Their main conclusions are correct (changes to radiation frequency and the fact that the magnetic field does have a significant role in the applied force) However there is an issue due to them ignoring some of the (relativistic) forces. Considering the claim that the particle ends up at rest despite some EM energy now travelling in different directions makes it clear that momentum must not have been conserved.
This paper simplifies the analysis by using a non-physical EM wave of infinite extent, but this helps them to calculate the full relativistic equations of motion. The final result matches the oscillations described by the other paper, but including the relativistic effects and radiation damping results in the particle accelerating in the direction of the Poyting vector, balancing the momentum issue I pointed out with the previous paper.
Note that the momentum related to the oscillations (and in particular the momentum not in the same direction as the Poynting vector of the incident wave) would be balanced by the instantaneous asymmetry in the fields produced and radiated by the charge. These fields would balance the momentum at all times if you bothered to calculate the EM momentum. (I do not intend to, working out all of the math would take more time than I feel like spending on this.)
I am just linking this paper for fun, since it shows how quantum mechanics complicates things. I do not believe it uses relativistic quantum mechanics (also called QED - Quantum ElectroDynamics).
Also, looking through these papers reminded me of another specific issue with your setup. The electrons travel slower than light, so the balancing charge to the charge on your plate will have to be nearby. Its distance will be less than one half-wavelength of the wave, so the opposite charge will almost certainly be close enough to be affected by the incident wave.
"That example may be simpler than your design, but it is not simple"
Now I make the simple version simpler. We assume that the charge is very heavy or it is connected with a very heavy object. And because half a cycle time is a very short time, so the charge will almost not move in half a cycle time. So we can consider the charge is always still in half a cycle time, and then we do not need to consider anything like oscillations, and it will be very simple. It is so simple that we don't even have to calculate it, just need the charge has enough amount of charge, the electric field force on the charge will be higher than radiation pressure.
"The electrons travel slower than light, so the balancing charge to the charge on your plate will have to be nearby. Its distance will be less than one half-wavelength of the wave, so the opposite charge will almost certainly be close enough to be affected by the incident wave."
Electromagnetic wave can propagate a very long distance, why you assume that the electromagnetic wave source must be nearby? -
#77 by meberbs on 02 Feb, 2016 05:17
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"That example may be simpler than your design, but it is not simple"
Now I make the simple version simpler. We assume that the charge is very heavy or it is connected with a very heavy object. And because half a cycle time is a very short time, so the charge will almost not move in half a cycle time. So we can consider the charge is always still in half a cycle time, and then we do not need to consider anything like oscillations, and it will be very simple. It is so simple that we don't even have to calculate it, just need the charge has enough amount of charge, the electric field force on the charge will be higher than radiation pressure.
The q/m ratio is a proportionality constant in many of the equations, increasing m and then increasing q will just cancel out. Also, the second paper I cited does the full equations to determine the motion so trying to simplify it is pointless.QuoteIt is so simple that we don't even have to calculate it, just need the charge has enough amount of charge, the electric field force on the charge will be higher than radiation pressure.
You seem to have trouble with the following concept: If you make simplifying assumptions, and then get a result that breaks something such as conservation of momentum, it means there was probably a problem with your assumptions.
In this case, you are not accounting for the fact that increasing the charge increases the force and therefore acceleration of the charge. This causes effects such as radiation damping/reaction which complicate everything. Hand waving doesn't work, you have to do the calculations, and the second paper I cited shows the general result, you can plug in different values for q and m if you want, but the basic characteristics and direction of the motion will not change.
Edit: I almost forgot the simpler issue that an electron is a point particle, so a naive radiation pressure calculation would yield 0 force, since Force = Pressure*Area and Area = 0. This is clearly not the actual case, and a charged particle has an effective area in which it disturbs the incident field. Increasing the charge increases this effective area, so there is no paradox with the force increasing. (This is a simple explanation that describes the general effects, more accurate details are in the papers I cited)"The electrons travel slower than light, so the balancing charge to the charge on your plate will have to be nearby. Its distance will be less than one half-wavelength of the wave, so the opposite charge will almost certainly be close enough to be affected by the incident wave."
Electromagnetic wave can propagate a very long distance, why you assume that the electromagnetic wave source must be nearby?
I am talking about the charge on the plate in your original design, not the source of the EM wave. If there is charge on the plate, and you are forcing oscillations of the charge between positive and negative, then the balancing charge must be nearby. Specifically, the maximum distance away this charge can be is equivalent to half of a wavelength. Since the amount to which you can focus a beam of photons is limited by its wavelength, the opposite charge will also feel force from the incident EM wave. -
#78 by ZhixianLin on 02 Feb, 2016 11:55
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"That example may be simpler than your design, but it is not simple"
Now I make the simple version simpler. We assume that the charge is very heavy or it is connected with a very heavy object. And because half a cycle time is a very short time, so the charge will almost not move in half a cycle time. So we can consider the charge is always still in half a cycle time, and then we do not need to consider anything like oscillations, and it will be very simple. It is so simple that we don't even have to calculate it, just need the charge has enough amount of charge, the electric field force on the charge will be higher than radiation pressure.
The q/m ratio is a proportionality constant in many of the equations, increasing m and then increasing q will just cancel out. Also, the second paper I cited does the full equations to determine the motion so trying to simplify it is pointless.QuoteIt is so simple that we don't even have to calculate it, just need the charge has enough amount of charge, the electric field force on the charge will be higher than radiation pressure.
You seem to have trouble with the following concept: If you make simplifying assumptions, and then get a result that breaks something such as conservation of momentum, it means there was probably a problem with your assumptions.
In this case, you are not accounting for the fact that increasing the charge increases the force and therefore acceleration of the charge. This causes effects such as radiation damping/reaction which complicate everything. Hand waving doesn't work, you have to do the calculations, and the second paper I cited shows the general result, you can plug in different values for q and m if you want, but the basic characteristics and direction of the motion will not change.
Edit: I almost forgot the simpler issue that an electron is a point particle, so a naive radiation pressure calculation would yield 0 force, since Force = Pressure*Area and Area = 0. This is clearly not the actual case, and a charged particle has an effective area in which it disturbs the incident field. Increasing the charge increases this effective area, so there is no paradox with the force increasing. (This is a simple explanation that describes the general effects, more accurate details are in the papers I cited)"The electrons travel slower than light, so the balancing charge to the charge on your plate will have to be nearby. Its distance will be less than one half-wavelength of the wave, so the opposite charge will almost certainly be close enough to be affected by the incident wave."
Electromagnetic wave can propagate a very long distance, why you assume that the electromagnetic wave source must be nearby?
I am talking about the charge on the plate in your original design, not the source of the EM wave. If there is charge on the plate, and you are forcing oscillations of the charge between positive and negative, then the balancing charge must be nearby. Specifically, the maximum distance away this charge can be is equivalent to half of a wavelength. Since the amount to which you can focus a beam of photons is limited by its wavelength, the opposite charge will also feel force from the incident EM wave.
"The q/m ratio is a proportionality constant in many of the equations, increasing m and then increasing q will just cancel out."
In the radiation damping force formula, I can't figure out how the q/m can be cancel out.
Anyway, no one has done a experiment to test it. And Dr. Rodal didn't say that it is not worth to do the experiment. I don't believe God is so cruel that will forbid humans have space travel.
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#79 by meberbs on 03 Feb, 2016 00:44
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In the radiation damping force formula, I can't figure out how the q/m can be cancel out.
I said many of the equations, not all of them. The radiation damping force in particular ends up being net directed in the direction of the direction of the Poynting vector of the incident wave, so this would not produce a force in the direction of the electric field.Anyway, no one has done a experiment to test it. And Dr. Rodal didn't say that it is not worth to do the experiment. I don't believe God is so cruel that will forbid humans have space travel.
I am not going to discourage performing the experiment. Dr. Rodal's advice to you on this was excellent, start by documenting exactly how you would build the device (don't worry about the force measurement part yet) and go from there:...
You are somebody: you proved this by taking the step to report your idea in this great forum (NSF) and get a number of responses. You just have to follow it up by thinking of how you would go about implementing your idea with actual components: this will:
No, I can't access any laboratory and I am nobody. I don't even know how to do a reliable simulation for my design. Can you do a simulation for it?
1) Help you find any reasons why your idea cannot be reduced to practice. If you find an error or you find you cannot reduce it to practice, then modify your idea or come up with a new one.
2) Enable you to write a patent (if in the process of reducing your idea to practice you create something that is not already known "to those skilled in the aerospace art").
3) Enable you to perhaps conduct your own Do It Yourself experiment (if you can safely do so) or get others to conduct their safe experiments.
I am very pro-space travel.
Right now the existing science for chemical and electric propulsion leaves room for practical travel within the solar system. Our best bets I can see for interstellar travel would be through general relativity (although all useful solutions I have heard of require negative energy densities), or new physics we will discover such as the true nature of dark matter and dark energy.
Right now the existing science for chemical and electric propulsion leaves room for practical travel within the solar system. Our best bets I can see for interstellar travel would be through general relativity (although all useful solutions I have heard of require negative energy densities), or new physics we will discover such as the true nature of dark matter and dark energy.