For the past few years, Hartnoll, Sachdev, and other theorists have been attacking the problem using a surprising “holographic duality” that mathematically connects systems of scrambled quantum particles, like those in strange metals, to imaginary black holes in one higher dimension. (The black hole pops out of the particle system like a hologram.) Remarkably, physicists find that black holes—incredibly dense, spherical objects whose gravity is so strong that not even light can escape—do the equivalent of Planckian dissipation, reaching a bound on how fast they can possibly scramble information that falls into them. In other words, black holes and strange metals go to extremes in some common way. The holographic duality is enabling the researchers to translate properties of black holes into dual properties of the scrambled-particle systems
EM drive is an attempt to convert electrical energy to forward momentum.
I would add slightly more definition to that, at least "at levels greater than a photon rocket." And maybe something constraining the problem to involve microwaves is a resonant cavity roughly shaped like a truncated cone.
The first addition I feel is necessary to separate it from the known way to turn electrical energy into momentum using a photon rocket. The second depends on what purpose you want to use the definition for. You don't need it to state just the purpose of the research, but it is needed to put some constraints on the scope. There is always another variable to change when working with something like this that has no sound theory to support it. At some point you can change so much that there is no actual meaningful relationship to what you started with, and it should have a new name. (Also by that point you need to admit the original device was actually a dead end.)
May I try again?
The purpose of the following sentence is to differentiate EM drive from the principle of a photon rocket.
EM drive is an attempt to convert electric energy to forward momentum by interacting with an object's inertia thru a suspected connection between inertia and electricity that has yet to be observed and confirmed in a replicable experiment.
It is thought that demonstrating this connection experimentally will lead to an expansion the theory of general relativity.
FYI: https://phys.org/news/2018-11-infinite-dimensional-symmetry-possibility-physicsand-particles.html
"The symmetries that govern the world of elementary particles at the most elementary level could be radically different from what has so far been thought. This surprising conclusion emerges from new work published by theoreticians from Warsaw and Potsdam. The scheme they posit unifies all the forces of nature in a way that is consistent with existing observations and anticipates the existence of new particles with unusual properties that may even be present in our close environs.
Read more at: https://phys.org/news/2018-11-infinite-dimensional-symmetry-possibility-physicsand-particles.html#jCp"
FYI: https://phys.org/news/2018-11-infinite-dimensional-symmetry-possibility-physicsand-particles.html
"The symmetries that govern the world of elementary particles at the most elementary level could be radically different from what has so far been thought. This surprising conclusion emerges from new work published by theoreticians from Warsaw and Potsdam. The scheme they posit unifies all the forces of nature in a way that is consistent with existing observations and anticipates the existence of new particles with unusual properties that may even be present in our close environs.
Read more at: https://phys.org/news/2018-11-infinite-dimensional-symmetry-possibility-physicsand-particles.html#jCp"Unfortunately those theoretical advances are created based on false assumptions and symmetry is a mathematical construct which does not exist in reality...
May I try again?
The purpose of the following sentence is to differentiate EM drive from the principle of a photon rocket.
EM drive is an attempt to convert electric energy to forward momentum by interacting with an object's inertia thru a suspected connection between inertia and electricity that has yet to be observed and confirmed in a replicable experiment.
It is thought that demonstrating this connection experimentally will lead to an expansion the theory of general relativity.
The "inertia" thing was just speculations from some theorists. It is not an inseparable part of the concept of EM drive. Let me try:
Em drive is an attempt to obtain thrust by keeping asymmetric microwave electromagnetic oscillation in the cavity inside a conductive container.
May I try again?
The purpose of the following sentence is to differentiate EM drive from the principle of a photon rocket.
EM drive is an attempt to convert electric energy to forward momentum by interacting with an object's inertia thru a suspected connection between inertia and electricity that has yet to be observed and confirmed in a replicable experiment.
It is thought that demonstrating this connection experimentally will lead to an expansion the theory of general relativity.
The "inertia" thing was just speculations from some theorists. It is not an inseparable part of the concept of EM drive. Let me try:
Em drive is an attempt to obtain thrust by keeping asymmetric microwave electromagnetic oscillation in the cavity inside a conductive container.PotomacNeuron,
that circumvents equal and opposite reaction.
What does constitute a mechanism for emdrive thrust without circumventing equal and opposite reaction, is radiation reaction acting on the charges of its internal surfaces. Such reaction is consequent upon quantum interactions that cannot escape the frustum but cause motion in the conduction electrons of the inside surface,
which could have a Coulomb interaction with the distant universe.
All perfectly logical and necessary in a Machian universe, a thing which deserves a lot more discussion on this forum.
(...)
there is some difficulty with the claim that that represents "equal and opposite reaction with the distant universe." Momentum conservation is still violated locally, and defining what instantaneous means for distant objects causes major problems, different observers will disagree on when the transfer happened, and therefore in what order it happened, and will see some momentum temporarily disappear, or be duplicated.
we assume that photons are the mechanism of all electromagnetic interaction. That is an assumption.
Yes, 'defining what instantaneous means for distant objects causes major problems' because we have as yet failed to work out how electromagnetic interaction works.
Until we do, it is presumptuous in the extreme to write off every alternative explanation on the basis that it doesn't agree with what we already know to be nonsense.
Dark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationally repulsive negative masses, which drive cosmic expansion and cannot coalesce into light-emitting structures. However, contemporary cosmological results are derived upon the reasonable assumption that the Universe only contains positive masses. By reconsidering this assumption, I have constructed a toy model which suggests that both dark phenomena can be unified into a single negative mass fluid. The model is a modified ΛCDM cosmology, and indicates that continuously-created negative masses can resemble the cosmological constant and can flatten the rotation curves of galaxies. The model leads to a cyclic universe with a time-variable Hubble parameter, potentially providing compatibility with the current tension that is emerging in cosmological measurements. In the first three-dimensional N-body simulations of negative mass matter in the scientific literature, this exotic material naturally forms haloes around galaxies that extend to several galactic radii. These haloes are not cuspy. The proposed cosmological model is therefore able to predict the observed distribution of dark matter in galaxies from first principles. The model makes several testable predictions and seems to have the potential to be consistent with observational evidence from distant supernovae, the cosmic microwave background, and galaxy clusters. These findings may imply that negative masses are a real and physical aspect of our Universe, or alternatively may imply the existence of a superseding theory that in some limit can be modelled by effective negative masses. Both cases lead to the surprising conclusion that the compelling puzzle of the dark Universe may have been due to a simple sign error.
https://arxiv.org/abs/1712.07962
A paper by J. S. Farnes proposes a negative mass model of cold dark matter and dark energy. By adding a Creation Tensor to the model, constantly adding negative-mass dark matter to the cosmos, the accelerating expansion of the universe is preserved. Interestingly, his "toy model" also predicts Dark Matter Halos around galaxies.Quote from: AbstractDark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationally repulsive negative masses, which drive cosmic expansion and cannot coalesce into light-emitting structures. However, contemporary cosmological results are derived upon the reasonable assumption that the Universe only contains positive masses. By reconsidering this assumption, I have constructed a toy model which suggests that both dark phenomena can be unified into a single negative mass fluid. The model is a modified ΛCDM cosmology, and indicates that continuously-created negative masses can resemble the cosmological constant and can flatten the rotation curves of galaxies. The model leads to a cyclic universe with a time-variable Hubble parameter, potentially providing compatibility with the current tension that is emerging in cosmological measurements. In the first three-dimensional N-body simulations of negative mass matter in the scientific literature, this exotic material naturally forms haloes around galaxies that extend to several galactic radii. These haloes are not cuspy. The proposed cosmological model is therefore able to predict the observed distribution of dark matter in galaxies from first principles. The model makes several testable predictions and seems to have the potential to be consistent with observational evidence from distant supernovae, the cosmic microwave background, and galaxy clusters. These findings may imply that negative masses are a real and physical aspect of our Universe, or alternatively may imply the existence of a superseding theory that in some limit can be modelled by effective negative masses. Both cases lead to the surprising conclusion that the compelling puzzle of the dark Universe may have been due to a simple sign error.
EDIT: The author wrote this entry as well
https://theconversation.com/bizarre-dark-fluid-with-negative-mass-could-dominate-the-universe-what-my-research-suggests-107922
(...)Yes, 'defining what instantaneous means for distant objects causes major problems' because we have as yet failed to work out how electromagnetic interaction works.Completely false. You are yet again making an assertion that physics does not describe phenomena that it is known to correctly describe. As I have said before when you keep repeating that scientists don't understand something that they do with no evidence to support your position, you are doing little other than lobbing insults at every scientist on the planet.
(...)
(...)Yes, 'defining what instantaneous means for distant objects causes major problems' because we have as yet failed to work out how electromagnetic interaction works.Completely false. You are yet again making an assertion that physics does not describe phenomena that it is known to correctly describe. As I have said before when you keep repeating that scientists don't understand something that they do with no evidence to support your position, you are doing little other than lobbing insults at every scientist on the planet.
(...)meberbs,
are you saying that you have a logical explanation for radiation reaction?
(...)Yes, 'defining what instantaneous means for distant objects causes major problems' because we have as yet failed to work out how electromagnetic interaction works.Completely false. You are yet again making an assertion that physics does not describe phenomena that it is known to correctly describe. As I have said before when you keep repeating that scientists don't understand something that they do with no evidence to support your position, you are doing little other than lobbing insults at every scientist on the planet.
(...)meberbs,
are you saying that you have a logical explanation for radiation reaction?Every good electrodynamics textbook explains it. As I have stated repeatedly (including in the post you just quoted), electromagnetic fields themselves can store energy and momentum. This is a fact both from experiment and derived straight out of basic electrodynamic theory. It should be intuitively obvious that if a charged particle emits radiation that carries away momentum, the particle itself must experience a force that balances the momentum carried away. Similarly, when something later absorbs that radiation, (or reflects it in another direction), it experiences the appropriate balancing force as radiation pressure.
If you want some of the math to back it up, here is a reference that describes some of the history of how this was derived. You can skip to section 15 for explicit formulas for change in energy and momentum.
http://www.physics.princeton.edu/~mcdonald/examples/selfforce.pdf
In "cme transport.pdf" file, PAGE 9:
"In (3+1) space-time dimensions, the pseudo-vector Pµ selects a direction in space-time and thus breaks the Lorentz and rotational invariance [22]: the temporal component M breaks the invariance w.r.t. Lorentz boosts, while the spatial component P picks a certain direction in space."
A DC current flowing along cavity's axis of symmetry direction can produce a magnetic field at skin depth region, but the effective percentage of mixing region with the internal fields depends on thickness of copper walls.
Can it inducing a chiral magnetic effect?
https://www.nde-ed.org/EducationResources/CommunityCollege/MagParticle/Physics/CircularFields.htm
meberbs,
that still assumes the same old argument, that the individual quanta of exchanged electromagnetic energy know where they are going as they are emitted. That breaks causality. You simply cannot have it both ways without assuming something like a pilot wave to fill in the logic gap, and those explanations are not physically real solutions.
This is not as complicated as it sounds but it does fail to fit into GR, QM or the fabulous standard model.
If emdrive thrust is measured, we need a better model of interaction to explain it, is all I'm saying. I know you cannot accept this but there may come a day when we may all need to because the evidence is too clear. I think that evidence is already clear and I am not the only one asking these questions.
Consider synchrotron radiation; the paths between emission and absorption narrow to a beam as the emitting electrons approach the speed of light. At lower velocity the distribution of those paths is wide. Quantum or field, causality requires us to reconsider the explanation you offer. If you have a seamless logical explanation, could we please hear it.
...
So far the evidence seems pretty clear that the emDrive does not work. It is basically beyond doubt at this point that all of the original claims of high thrust from Shawyer are inaccurate.
...
(...)
So far the evidence seems pretty clear that the emDrive does not work. It is basically beyond doubt at this point that all of the original claims of high thrust from Shawyer are inaccurate.
What I can't accept is why you continue to implicitly call every scientist on the planet an idiot by insisting that there are contradictions in theories that are universally accepted to be self-consistent and match experimental data within all measurable regions of applicability.