DarkMatterHol said:
The model does appear to be irreconcilable with 'quantum uncertainty' model though, does it not?
Yes, it is; but as I've pointed out in other threads (including the ones I linked to just now), it's also irreconcilable with ordinary *classical* uncertainty. In order to construct a fully deterministic classical model of the entire universe, you have to have a set of initial data on an entire spacelike slice. We do not have such a data set and never will: the best we can do is the set of data in our past light cone, which only covers a finite portion of any spacelike slice. That data is not sufficient to deterministically predict what will happen at any event that is spacelike separated from us; we can extrapolate from the data in our past light cone to say what *might* happen at such events, but any such prediction basically assumes that nothing of any interest happens outside our past light cone, which is a very extravagant assumption.
This point is glossed over in thought experiments because in thought experiments, we *make up* the data: we just declare by fiat that the events we put into our model are the only events of interest. Of course if you do that, you are basically declaring the initial data on an entire spacelike slice, so of course you can construct a deterministic model. But in the real world, we can't do that, and the argument for the "block universe" based on relativity of simultaneity requires us to assume that we can; otherwise the argument does not go through.
To put it another way, the argument for the block universe based on relativity of simultaneity requires us to assign physical reality to "simultaneous spaces": but that amounts to assuming the conclusion! We don't directly observe simultaneous spaces; we only observe what's in our past light cone. We *construct* simultaneous spaces in our model in order to help us understand what's going on; but they are not required to make predictions and no physical observable depends on them being physically real. The only reason to believe they are physically real is that the "block universe" view says they are; but of course that means you can't use the reality of simultaneous spaces as an argument for the "block universe" view, because you'd be arguing in a circle.
I should clarify, btw, that all the classical theories we have--Newtonian mechanics, Maxwell electrodynamics, special and general relativity--*are* deterministic in the sense I gave above; so if any of these theories were actually true of our world (which they aren't because of quantum mechanics), our world would in fact be deterministic. But that still wouldn't make Greene's argument for the "block universe" based on relativity of simultaneity valid; it would just mean he happened to hit on the right answer, but for the wrong reason.
