It is clear that we are operating under other than usual symmetry conditions and that Maxwell's equations as we were trained to use them do not apply.
Quote from: Mulletron on 04/30/2015 08:05 pmIt is clear that we are operating under other than usual symmetry conditions and that Maxwell's equations as we were trained to use them do not apply.What are you talking about? Maxwell's equations apply to EM radiation unequivocally. Especially in these low power regimes there is no chance of observing any perturbations due to higher order effects from field theory.Look, I want to believe in a "reactionless" drive as much as the next SF junkie, but this does not pass the smell test. Consider:e0. The proposed explanations violate: conservation of energy, conservation of momentum, and the Lorentz transformations. These are some of the best-tested physical arguments we have today, and yet this "drive" violates them by huge orders of magnitude. Is it really plausible that 100+ years of experiments have failed to notice a comparatively huge effect? RF cavities are not a poorly understood system. I used to work with superconducting RF cavities for particle accelerators with Q > 1 million supporting fields of > 10 MV/m. I can guarantee you we would have noticed if power was disappearing into "thrust", or if the damn things were starting to levitate. 1. Even if we are pushing against the "quantum vacuum" this does not make sense, as any such vacuumo must be charge neutral and so we would be pushing in opposite directions on electrons and positrons. Not to mention the accelerated positrons would smash into the surrounding cavity, producing copious, easily-observable gamma rays.1a. Even ignoring this objection, to promote particles from "virtual" to real (as in Hawking radiation...) you have to provide the particles with their mass-energy. 511 keV per electron/positron. Does this make sense?Assume 100% of the energy delivered to the cavity goes into making virtual particles real: 100 W / (mass of electron * c^2) = 1e15 electrons / s. Assume the particles are instantaneously acclerated to the speed of light (a pretty generous assumption). Then F = (1e15 electron/s)*(mass of electron)*(speed of light) = 2e-7 newtons. Much smaller than what we observe. The explanation does not hold up to scrutiny.2. The "quantum vacuum"/Casimir effect should not be given more emphasis than is appropriate. It is a calculational tool. For example, one can explain the casimir effect solely through the van der Waals forces between two neighboring conductors, without handwaving explanations about virtual particles: http://physics.stackexchange.com/questions/11544/vander-waals-and-casimir-forces3. The quantum vacuum publication referenced earlier is really, really bad. It starts with the Bohr formula for hydrogen (thus neglecting any fine structure, etc... effects), and takes a "radius" (which as we know from QM should not be interpreted literally...) to get a volume and from that some kind of density. This has no physical meaning. Then a function 1/r^4 is fitted to the values -- with no justification! This is then compared to the casimir force for cavities separated by this radius... and the values are pretty far off. But it looks like a factor of 1/3! So some further handwaving about general relativity which also has a factor of 1/3 in one equation! Then there's a whole word salad about solving hydrogen atom wavefunctions with COMSOL [], which is ridiculous since any undergraduate physics students can solve them with pen and paper... This papers seems explicitly designed to use lots of fancy terminology and equations to look impressive to anyone with no background in physics, while saying nothing at all of substance. It does not even rise to the level of coherence.In conclusion, this whole affair appears to be the work of someone who has convinced himself his theory is right and is on a fishing expedition for evidence that supports it. The experimental design is poor (camera pictures of LabView windows? unable to find an RF amplifier to deliver more than 100W of power? inability to measure forces that would be measurable in the 1800's?), the past 100+ years of physical experiments contradict the experiments, and there is no coherent underlying theory.This is not science, it is cargo cult science.
I'm going to wallop you in the morning. Hope you know what you're attacking me for (what I've been advocating which isn't QVPT BTW) You might want to make sure you have your facts straight. This is your head start.
This is not science, it is cargo cult science.
I still don't understand why major laboratories can't be enlisted to verify or disprove the phenomenon.
Quote from: sanman on 04/30/2015 09:29 pmI still don't understand why major laboratories can't be enlisted to verify or disprove the phenomenon.Because it is obvious pseudoscience and is treated as such (unlike e.g. early cold fusion, which didn't look anywhere near as silly and resulted in many replication attempts worldwide).
Quote from: Dmytry on 04/30/2015 09:41 pmQuote from: sanman on 04/30/2015 09:29 pmI still don't understand why major laboratories can't be enlisted to verify or disprove the phenomenon.Because it is obvious pseudoscience and is treated as such (unlike e.g. early cold fusion, which didn't look anywhere near as silly and resulted in many replication attempts worldwide).Naked disdain on the grounds of established theory, without citation of related experiments or numerical analysis, is unhelpful and unproductive.
Quote from: Dmytry on 04/30/2015 09:41 pmQuote from: sanman on 04/30/2015 09:29 pmI still don't understand why major laboratories can't be enlisted to verify or disprove the phenomenon.Because it is obvious pseudoscience and is treated as such (unlike e.g. early cold fusion, which didn't look anywhere near as silly and resulted in many replication attempts worldwide).Pseudoscience in what sense? Is it based on falsifiable assertions or not? As far as I know, yes. Either it provides thrust or it doesn't. "Eppur si muove" at its best.Can it be replicated? Sure, there's nothing magical with the setup. Any willing and able engineer could make one (and several around here are).Does it work? We don't know for certain yet. There are hints of the answer being yes, but more replications are in order.Should we ban and discourage any experiments on this obviously silly idea, only because it goes against our models and theories? Definitely not.
So, an opinion here - I think this thread should be kept as the place where all the theorycrafting and experimental work is specifically discussed by (by and large) the people involved. The strong skepticism and debate over the practicality/realism of the technology and etc ought to be taken perhaps to the article thread, to keep this one cleaner and more usable/readable.
If you have a new physical theory which predicts some phenomenon, it should reduce to previously known physical theories, and be able to explain existing experiments and observations. If I believe that the EM drive is actually providing some nonclassical, unexplained thrust, I must throw out 100+ years of physics experiment and theory. I choose not to do that, which is why I do not believe further experimentation is warranted. Others may choose differently, but then they should ask themselves why they are so eager to disregard such a large body of established science.