RE: [Vo]:Re: EM Drive(s)Jones-- Spin waves are discussed in the Ferromagnetism book I identified in this thread--
Ferromagnetic Resonance: The Phenomenon of Resonant Absorption of a High ... edited by S. V. Vonsovskii I did not want to raise any more controversy! Thanks of keeping me in mind anyway. Bob Cook From: Jones Beene Sent: Tuesday, March 15, 2016 8:31 AM To: vortex-l@eskimo.com Subject: RE: [Vo]:Re: EM Drive(s) A related but alternative bit of insight comes from John Wallace in the cited paper on spin waves. I thought Bob Cook was aware of it, but maybe not since he did not bring up the most important detail - mass. It would be relevant to Shawyer’s drive if the Frustum were to have an iron liner component, such as an inner layer of sheet iron or even iron plating, which is not the case, but anyway this paper is worth a read on the off-chance that copper can produce spin waves like iron (doubtful). http://arxiv.org/abs/0901.1631 In Wallace’s hypothesis, applied to Sawyer, RF would be converted into transverse (spin) waves. These waves have special properties and importantly they have mass. One dispersion curve yielded a real but exceedingly small effective mass of 1.8 10^{-39}kg for spin waves… which is not too far removed from the mass energy of the microwave photon which created it. But unless the copper frustum acts to release the same spin wave as does iron this explanation does not work for Em. Plus, since these waves have mass, they can be depleted over time without a replenishment source which spoils the idea of very long space missions. Most of the idealists balk at a theory that doesn’t get them access to intergalactic Sci-Fi missions. J There are other partial explanations which actually mesh with spin waves. Shawyer claims that a standing wave interference pattern is created by geometry, operating frequency path lengths. And he claims that “stress energy of space” is altered by the interference pattern. That sounds a lot like aether. A chiral aether with effective mass, together with spin waves of effective mass – that would explain everything - yet observers shy away. Too bad. A third slant is Puthoff's patent - showing that a small but detectable curl free potential can be created from interference patterns passing through barriers, presumably like a copper wall. If the microwaves remain inside the cavity, then there is no interaction with the vacuum except by invoking a massive wave, and consequently, there is no established theory to give external thrust to the device except the Wallace approach, which comes the closest since it predicts wave-particles of low-but-real mass. Wallace does have real uncontested data for spin waves whereas Shawye’s data is challenged. Original Message----- From: Eric Walker Bob Cook wrote: If a pulsed magnetic field is involved in the EM drive it may be that effective momentum is sent off into space as a pulsed magnetic field with some effective mass associated with the average intensity of the magnetic field pulse—energy associated with the pulse. This is along the lines that I was thinking. Consider a simple thought experiment. We have a microwave waveguide with the output focused in a single direction sitting out in the middle of space where there is little in the way of an external field. Attached to it is a battery sufficient to drive a magnetron at 10 W for some period of time. We turn on the magnetron remotely. Microwave photons with a total power amounting to 10 J per second are now being emitted in a preferred direction. For the sake of argument we will go with the well-accepted assumption that photons have no mass. Nonetheless they have momentum, and in order for the system to conserve momentum it will move in a direction opposite the majority of the photons. We have yet not specified what the system is pushing off of, but I don't think we need to in order for the thought experiment to work. Eric