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Re:Curious Link Between the Fly-By Anomaly and the “Impossib... by alkonaut on Sunday April 24, 2016 @06:41AM (#11559226)
Thanks. For the supposed violations - aren't we still then only discussing the device working within known physics? There is no violation if the device were to slowly lose mass due to some unknown process (making it a form of Ion thruster), or if it accelerates some yet unknown weakly interacting massive particle in the opposite direction of the thrust, or if it somehow only conserves invariants for a "larger" system, potentially the entire universe?

Given an exotic enough explanation (negative energies/faster than light particles/spacetime warping/..) it feels like you can cheat your way around almost any invariant? Occam is left weeping in a corner of course.

Re:Curious Link Between the Fly-By Anomaly and the “Impossib... by raattgift on Sunday April 24, 2016 @12:29PM (#11560247)
Sure, if it's not actually reactionless, most objections fall away.

The problem with reaching for exotic particles or the like is that we don't see them in searches which involve tens of orders of magnitude more power, and we certainly don't see them in, for example, electric toasters or radar sets. So what would need explaining is what's peculiar about the EmDrive with respect to (extremely) unusual particle interactions, and there is [a] nothing obvious and [b] nothing at all in the "theory" paper.

Likewise, reaching for non-local physics answers raises similar questions (why is EmDrive doing non-local whatever but my kettle isn't; or alternatively, why is EmDrive coupling with whatever much much much more strongly than my conventional oven is).

I have another pair of things that you can add to the list: [a] EmDrive somehow violates causality in a way that other similar arrangements of mass-energy-momentum does not and [b] EmDrive somehow escapes logic in a way that other similar systems under study does not. These are neither more far-fetched nor more unpalatable, compared to abandoning local physics (causality and logic preserved, but hidden non local variables proliferate) or abandoning the Standard Model as an accurate low-energy theory of matter (causality, logic and locality preserved, but now what happens in the molecules and atoms of cars, computer chips, and light bulbs? we no longer can be quite so sure!).

There is A LOT of known physics and almost exactly zero examples of violations of the known invariants at low particle energies. You are re-testing relevant parts of all that in reading this comment.