Q-reeus
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Can't quite follow that bit - isn't it the case we are relying on conservation of energy-momentum to explain the fit between data and theory?TrickyDicky said:...in the specific case of the binary pulsar (Hulse-Taylor pulsar), when we interpret the shrinking of the binary system orbit as energy lost by emission of gravitational radiation, we are relying on the fact that in GR there is no global energy-momentum conservation (at least for the quadrupole momentum)...
The striking fit of that Hulse-Taylor pulsar data to theory convinces me that for sure GW's exist and carry positive energy. For other situations things make much less sense, unless somehow there is a complete break from the (approximate) quadrature dependence between 'stress' and energy density for both static and radiative fields that sensibly applies to EM, acoustics etc. I can't see how there could be consistency, but maybe someone here knows. Or not. Just came across the following perfectly kosher presentation of GW physics that may answer at least some of your questions, but honestly your best bet may be contacting someone like Kip Thorne direct:
The Physics of Gravitational Waves and their Generation - K.Thorne http://www.ilorentz.org/lorentzchair/thorne/Thorne1.pdf (really starts p12, p14 contains a minor gaff re 'spin' formula)
Going through it, but still can't see where background (ie static) curvature is assigned some energy density.