Joao Leao writes:
> I don't believe that there is ANY question that QM is non-local! This is
> the outcome of 30 years of experiments with entangled multiparticle
> states. I also think that non-locality is pretty well defined in this
> context (the way Bell put it) and we know what implications it has
> in the laboratory and elsewhere.
Philosophically the real question is not why QM is non-local, because
there is no a priori reason the universe should be local. The question
is why the universe is so nearly local; why it appears to be local
for all practical purposes, if it is built on non-local underpinnings;
why the non-local connections are unable to affect causality.
In the all universe hypothesis, all theories of physics are instantiated.
Only in some universes will life and consciousness evolve. Perhaps it is
plausible that locality, or something like it, is a necessary precondition
for the kinds of mechanisms that allow computation. And we believe that
computation is necessary for consciousness.
So it is reasonable that the universe will be at least superficially
or approximately local. It still seems surprising that this property
can be built on a non-local foundation, with the non-localities somehow
cancelling themselves out or becoming insignificant at certain scales.
I suspect that it will turn out that this paradoxical physics is actually
one of the simplest models that both provides for a sufficiently complex
and varied universe to allow spontaneous evolution; and a sufficiently
stable and local one that computation can exist. QM gives us ~100 kinds
of atoms that can form an infinite variety of molecules; gravity gives
us stars that synthesize sufficient quantities of a substantial variety
of these atoms, and planets which concentrate the intermediately sized
atoms together. It might well be difficult to reproduce such combinations
of properties if we had different physical laws.