Considering that NASA will fly just about anything of scientific note into space for the cost of the paperwork (and the Ukrainians will fly anything for you for less than $100k) most of these gadgets could be demonstrated in LEO.. if they worked.
So, before I trundle off to bed...(be'in old an' all)When we are in the AFR that removes the cavity dispersion at the expense of splitting the frequency into doppler components, and giving us a flat metric tensor, what tensor quantities can we generate which will give zero force in this frame (despite the difference in frequency) and allow us to find the force in the rest frame of the cavity. Then the question is: can this be done in GR or does it need extensions (such as Sachs-Schwebel, etc)
By the way, John Baez (in his blog https://plus.google.com/117663015413546257905/posts/C7vx2G85kr4 , answering correspondence) had some non-flattering things to say about Woodward's approach as well.
As Chris Bergin made clear, the purpose of this forum is to deal with SPACEFLIGHT APPLICATIONS (of EM Drives: those propellantless drives comprised of a microwave cavity as the devices tested by Shawyer in the UK, Prof. Juan Yang in China and Brady, March, White, et.al. at NASA):Why is this prescription by Chris Bergin being ignored?Although the latest Woodward experiments (Fearn, Zachar, Woodward & Wanser) show that it takes 20,000 times more power to produce a given level of thrust than the power required to produce the same thrust for the EM Drive (Shawyer demo), and therefore these experiments do not constitute "EM Drive Spaceflight Applications" (as instructed by Chris Bergin) Woodward fans persist on carrying a debate on this thread rather than their own Woodward thread. Frankly, I don't understand what is the goal being pursued here by Woodward-effect fans to insist to carry arguments concerning Woodward's theory and experiments in this thread. The curtailment of the previous EM Drive thread by this forum's moderator was due to disruptive discussions regarding the validity of the Woodward effect, including a negative review of Woodward's book by a physicist.
Good that Shawyer has clarified the force measurement. Referring to his Fig. 1 from the paperhttp://www.emdrive.com/EmDriveForceMeasurement.pdfand reproduced below, I conclude he is saying the force that is acting on the EM-drive is in the same direction as the vector labeled T. The only difficulty I have with this is from looking at the videos of the EM=drive. When it is operating it moves with the small end forward.In the earlier thread I stated that maybe the thrust was due to heat convection from the sloped sides. This was dismissed because the EM-drive moves in the opposite direction as seen in the video.
It therefore appears that a force measurement can only be made in a dynamic environment, ideally by allowing the thruster to accelerate, measuring that acceleration, and then calculating the thrust from T = - Ma. This is not a very easy method, although the SPR Demonstrator Thruster was successfully tested in this way on a rotary air bearing
...and your point is?