This is a good, top-level article about all this:
http://www.ldolphin.org/vanFlandern/gravityspeed.html
Last 2 paragraphs:
Near the end of his career, Lorentz is quoted as having graciously conceded the contest: “My theory can obtain all the same results as special relativity, but perhaps not with a comparable simplicity.†(private communication from C.O. Alley) Today, with hindsight, we might make a somewhat different assessment: “Special relativity can explain all the experimental results in Table II that Lorentzian relativity can, but perhaps not with a comparable simplicity.†Even so, SR cannot explain the faster-than-light propagation of gravity, although LR readily can.
We conclude that the speed of gravity may provide the new insight physics has been awaiting to lead the way to unification of the fundamental forces. As shown in (Van Flandern, 1993, pp. 80-85 and Van Flandern, 1996), it may also be connected with the explanation of the dark matter problem in cosmology. Moreover, the modest switch from SR to LR may correct the “wrong turn†physics must have made to get into the dilemma presented by quantum mechanics, that there appears to be no “deep reality†to the world around us. Quantum phenomena that violate the locality criterion may now be welcomed into conventional physics.
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My two cents: light doesn't travel at any speed except in relative terms. Relatively speaking, it travels faster than motor cars. But in fact, it is the observer that creates some of the conditions for Point A and Point B to exist between which the light is deemed to 'travel'. Without such relative reference points, light would not be travelling at all. In other words, you could say that everything is moving and the light is still in that as 'it' travels from Point A to Point B, its inter-relationship with everything else in the universe is changing and all other such inter-relationships with each other. So the entire universe is traveling at the same speed, whether it be a rock not moving apparently, or a light beam moving apparently.
If this makes no sense consider the many quantum-lineage experiments which discovered that particles moving in one place that were 'jiggled' seemingly caused other particles in a different place to 'jiggle' in exactly the same way, as if they were connected somehow. Clearly they were part of the same field somehow, meaning that their apparently independent nature as particles was not as it seemed even though they could be discerned as particles with clear delineations physically. So in terms of being parts of the same overall continuum there is no speed really. But I suspect this is somewhat a cheap point I am making. In any case, the above article strikes me as very high quality stuff and does purport to prove that gravity travels at speeds far higher than light.
Also, numerous experiments have shown that light speed is not constant in any case. Much of Einstein's work was plagiarised (including the formula E = MC2 which he did not develop) and his work was quite shoddy and inconsistent. And that goes back to Kevin's title: so much of what passes for 'science' is bad science to start with and far more unclear or work-in-progress like than scientists like to acknowledge. It really should be called scientism.
