I didn't see this before I posted the other one. Here are some more comments:
Bruce is our Forum relativity expert. I am not.
I find this funny. If modern physics is too complex to be understood as a whole even by professionals, what can a poor fellow like me possibly do? :-)
The above quote is the only place where he alludes to dark matter, or non-locality and unification for that matter. He makes a strong case that the speed of gravity is essentially instantaneous. But not believing in instantaneity, he says that the gravity speed must be at least 2x10^10 the speed of light. No theory is offered for how this could be true. His argument is purely on experimental grounds. He does imply that physicists have been hood-winking us.
I would be surprised if his theories are error-free, but I find his approach quite honest. On the other hand, the academic position doesn't always strike me as fully honest.
1. Dark matter: Since newtonian theory is used to predict dark matter, in which the speed of gravity is already infinite, I do not see how his arguments for the speed of gravity could change that analysis. Mike's link above also supports the existence of dark matter with no mention of the speed of gravity.
As I said in my other post, it really has nothing to do with the speed of gravity, but rather with the assumption that the inverse square law applies to gravity at any distance. He claims it's possible that gravity decays by the inverse square law up to some finite distance, then another law takes place. That would make a lot of sense if gravity were quantized; the inverse square law would apply only for distances where averaging gives accurate results.
2. Non-locality; He is suggesting that since gravity propagates essential with infinite speed, then that solves the Aspect Exp / entanglement problem, presuming that gravity somehow carries information about the states of the two particles entangled. I think it's unlikely that gravity can carry such info.
I'll take your word for it as QM baffles me.
3. Unification: Here he may be on to something that I have been talking about for some time. He claims that for causality, particles that travel much faster than the speed of light- almost at infinite speed- are required. There is only one place where such particles are predicted, in 26-D string theory. That theory predicts the existence of tachyons that can travel up to infinite speeds (almost by definition). I do not understand how they calculate that a closed string can move so fast. But the literature is clear that it is so(See the 2 vol. book by Schwarz, Green & Witten). That would suggest that the 26-D unified field is actually the gravitational field.
I don't know what he thinks about string theory, but I do like his opinion on unification: he believes it can't be done. He claims to have formal proof of it, I just happened to reach that conclusion intuitively. What he believes, and I agree, is that there are no fundamental laws, that there are in fact an infinite number of levels of explanation, none of them fully coherent as "high-level" explanations always ignore important details from "lower-level" ones. I think this makes perfect sense. He also believes the universe never had a beginning, that it existed forever in the past, which is what I eventually came to realize.
Anyway, back to unification, it's possible that string theory is one level below QM, just as QM is one level below classical mechanics, but I doubt it will be the final GUT as I don't believe such a thing can possibly exist.