(FWIW, my daughter is getting her PhD in physics at the moment, and she's using the same copy of J.D. Jackson that me and her mom used for graduate physics. High current E/M microwave has some surprises when you apply it to accelerators (me - surprisingly relates to propulsion too), fusion plasmas (her mom), and planetary/cosmic phenomena (her), where RTI for the interface/"impedance match" is different (Euler function solution)). )
Quote from: Space Ghost 1962 on 05/16/2017 04:50 pm(FWIW, my daughter is getting her PhD in physics at the moment, and she's using the same copy of J.D. Jackson that me and her mom used for graduate physics. High current E/M microwave has some surprises when you apply it to accelerators (me - surprisingly relates to propulsion too), fusion plasmas (her mom), and planetary/cosmic phenomena (her), where RTI for the interface/"impedance match" is different (Euler function solution)). )Must be interesting dinner conversations. Relativistically speaking.
This was one of the first primers I read almost two years ago when I started my quest for actions within the closed cavity of an EMDrive. https://www.microwaves101.com/encyclopedias/waveguide-primerThen referenced many times...https://archive.org/stream/ClassicalElectrodynamics/Jackson-ClassicalElectrodynamics#page/n253/mode/2up There still exists some confusion (and rightly so) of the actions of microwaves in a closed resonating asymmetric waveguide. When your trying to comprehend actions of Electric, Magnetic fields, photons, trapped and accelerating particles, possibly plasma generation, different TE TM modes, even evanescent wave actions and then how this Betty Crocker Blender maelstrom interacts with the materials of the frustum... IMHO it becomes much much more than just simple bouncing photons.Needless to say I'm still learning and finding new material to explain the why. Currently I've over 2500 papers and links to something relevant with this drive. My Very Best,ShellCorrected writing mistakes.
Shell, maybe we should start a links page or such with a search bar so that newcomers can see the extent of what is available. Even just a list of the arxiv links already shared on this forum would help. If we all contributed our own collections it could be a thing. Any ideas?Quote from: SeeShells on 05/16/2017 01:44 pmThis was one of the first primers I read almost two years ago when I started my quest for actions within the closed cavity of an EMDrive. https://www.microwaves101.com/encyclopedias/waveguide-primerThen referenced many times...https://archive.org/stream/ClassicalElectrodynamics/Jackson-ClassicalElectrodynamics#page/n253/mode/2up There still exists some confusion (and rightly so) of the actions of microwaves in a closed resonating asymmetric waveguide. When your trying to comprehend actions of Electric, Magnetic fields, photons, trapped and accelerating particles, possibly plasma generation, different TE TM modes, even evanescent wave actions and then how this Betty Crocker Blender maelstrom interacts with the materials of the frustum... IMHO it becomes much much more than just simple bouncing photons.Needless to say I'm still learning and finding new material to explain the why. Currently I've over 2500 papers and links to something relevant with this drive. My Very Best,ShellCorrected writing mistakes.
I can't decide if this is more topically related to this thread or to the Mach effect thread...https://phys.org/news/2017-05-nature-great-puzzles-expansion-universe.htmlEssentially it is about quantum vacuum energy dark energy and counter balancing small scale forces that lead to a tiny inflationary effect in cosmology. The relevance here is no one working on EM drives know what would cause the effect observed if it is not an artifact of experimental error. It could be this or it could be that or the other. So here is an "other" for us to consider.
The paper referenced is here on the arXiv:How the huge energy of quantum vacuum gravitates to drive the slow accelerating expansion of the Universe...a *fun* read.Quote from: Stormbringer on 05/15/2017 06:15 pmI can't decide if this is more topically related to this thread or to the Mach effect thread...https://phys.org/news/2017-05-nature-great-puzzles-expansion-universe.htmlEssentially it is about quantum vacuum energy dark energy and counter balancing small scale forces that lead to a tiny inflationary effect in cosmology. The relevance here is no one working on EM drives know what would cause the effect observed if it is not an artifact of experimental error. It could be this or it could be that or the other. So here is an "other" for us to consider.
English wheel? You making custom choppers? ceremonial plate mail?
That would be a large undertaking and what I read now can be a moving target. i.e. My current buzz.https://www.researchgate.net/publication/307964475_Propagation_of_photons_in_a_medium_and_refractive_indexLet me think about it and open to ideas from the group as well.My Very Best,ShellQuote from: spupeng7 on 05/17/2017 01:43 amShell, maybe we should start a links page or such with a search bar so that newcomers can see the extent of what is available. Even just a list of the arxiv links already shared on this forum would help. If we all contributed our own collections it could be a thing. Any ideas?Quote from: SeeShells on 05/16/2017 01:44 pmThis was one of the first primers I read almost two years ago when I started my quest for actions within the closed cavity of an EMDrive. https://www.microwaves101.com/encyclopedias/waveguide-primerThen referenced many times...https://archive.org/stream/ClassicalElectrodynamics/Jackson-ClassicalElectrodynamics#page/n253/mode/2up There still exists some confusion (and rightly so) of the actions of microwaves in a closed resonating asymmetric waveguide. When your trying to comprehend actions of Electric, Magnetic fields, photons, trapped and accelerating particles, possibly plasma generation, different TE TM modes, even evanescent wave actions and then how this Betty Crocker Blender maelstrom interacts with the materials of the frustum... IMHO it becomes much much more than just simple bouncing photons.Needless to say I'm still learning and finding new material to explain the why. Currently I've over 2500 papers and links to something relevant with this drive. My Very Best,ShellCorrected writing mistakes.
Hoping I can phrase a concise question about Physics:Suppose a charged particle is being accelerated, but very slowly. The radiation emitted due to the acceleration would have a very long wavelength. If there was a (?quantum?) cut-off which prevented radiation being emitted above a certain wavelength, or equivalently that the energy of the photon emitted was above some lower limit, then in principle momentum would cease to be conserved - or rather, behavior will become non-classical in some other way, I suppose.My question for this audience is: does anybody know of any experiment or operational device which could either bound the wavelength threshold, or eliminate this as a feasible mechanism?
Guys and Gals:What the heck is this all about? I thought we had only had emergent or pseudo-monopoles.... what are they saying here? An emergent monopole decays into another form of emergent monopole? eh? "Cause monopoles are a big freaking deal if they are real.https://phys.org/news/2017-05-destruction-quantum-monopole.html
Quote from: Stormbringer on 05/17/2017 11:43 pmGuys and Gals:What the heck is this all about? I thought we had only had emergent or pseudo-monopoles.... what are they saying here? An emergent monopole decays into another form of emergent monopole? eh? "Cause monopoles are a big freaking deal if they are real.https://phys.org/news/2017-05-destruction-quantum-monopole.htmlWell, I think magnetic monopoles are nonsense, so maybe I'm the wrong person to answer this question.
Quote from: Stormbringer on 05/18/2017 03:06 amEnglish wheel? You making custom choppers? ceremonial plate mail? hehe no, I also restore old cars with my SO and sometimes it's needed. Just metal working.Daily driver.My Very Best,Shell
Abstract:We investigate the gravitational property of the quantum vacuum by treating its large energy density predicted by quantum field theory seriously and assuming that it does gravitate to obey the equivalence principle of general relativity. We find that the quantum vacuum would gravitate differently from what people previously thought. The consequence of this difference is an accelerating universe with a small Hubble expansion rate H∝Λe−βG√Λ→0 instead of the previous prediction H=8πGρvac/3−−−−−−−−√∝G−−√Λ2→∞ which was unbounded, as the high energy cutoff Λ is taken to infinity. In this sense, at least the "old" cosmological constant problem would be resolved. Moreover, it gives the observed slow rate of the accelerating expansion as Λ is taken to be some large value of the order of Planck energy or higher. This result suggests that there is no necessity to introduce the cosmological constant, which is required to be fine tuned to an accuracy of 10−120, or other forms of dark energy, which are required to have peculiar negative pressure, to explain the observed accelerating expansion of the Universe.
Quote from: spupeng7 on 05/18/2017 06:18 amQuote from: Stormbringer on 05/17/2017 11:43 pmGuys and Gals:What the heck is this all about? I thought we had only had emergent or pseudo-monopoles.... what are they saying here? An emergent monopole decays into another form of emergent monopole? eh? "Cause monopoles are a big freaking deal if they are real.https://phys.org/news/2017-05-destruction-quantum-monopole.htmlWell, I think magnetic monopoles are nonsense, so maybe I'm the wrong person to answer this question.I'm not sure why you think magnetic monopoles are nonsense, their behavior has a strong theoretical foundation, and if they exist it would actually help explain some things like charge quantization. Of course we haven't detected any, and they don't fit in the standard model, but they are the type of thing scientists could expect to show up as part of a very high energy extension to the standard model.As for the article "An emergent monopole decays into another form of emergent monopole?" seems to be exactly what they are saying. I don't really understand how these fake monopoles work, what properties they have, or what the real importance of this research is, but it seems clear to me that while the system was reverting from the special monopole-like state they had put it in, it passed through a different type of monopole-like state.