On 4 February 2014 23:25, Bruno Marchal <[email protected]> wrote: > > On 04 Feb 2014, at 00:29, LizR wrote: > > On 4 February 2014 12:23, Jesse Mazer <[email protected]> wrote: > >> On Mon, Feb 3, 2014 at 5:48 PM, <[email protected]> wrote: >> >>> >>> But more generically speaking, would this inference for blocktime sit at >>> the edge of relativity or at its core. What I mean is, beyond that it is an >>> implication of relativity, have there been or are there any prospects for >>> developing blocktime as it arises from relativity to such point, >>> predictions get made? Or any other kind of reinforcement? Or does blocktime >>> go on to imply something beyond blocktime? >>> >> >> If "block time" is taken as a definite ontological statement about all >> times "existing" in exactly the same sense, rather than just referring to >> the idea of treating time as a dimension conceptually or in our >> mathematical models, then I think it's a metaphysical postulate that goes >> beyond anything directly implied by relativity. Relativity says that all >> frames, with their different definitions of simultaneity, are on equal >> footing as far as the laws of physics are concerned, but it doesn't deal >> with ontology. If someone proposes that one frame's definition of >> simultaneity is "metaphysically preferred" in the sense it defines the >> "true present", but adds the caveat that this frame is not in any way >> physically preferred so that no conceivable experiment could determine >> which frame it is, this wouldn't contradict the physics. It would be an >> "interpretation" of SR, similar to the different "interpretations" of QM >> which postulate different things about ontology (the real existence of >> other worlds in the MWI, or a single world with hidden variables in Bohmian >> mechanics, for example) but are indistinguishable experimentally. >> > > SR directly demonstrates block time via the relativity of simultaneity. > This can be tested experimentally. > >> >> That said, if you subscribe to any form of Occam's razor or even a >> criteria of "elegance" when it comes to choosing between different >> metaphysical hypotheses, it seems a lot simpler to assume that there is no >> metaphysically preferred definition of simultaneity, just as I think many >> would agree the MWI is the simplest way of interpreting the physical theory >> of QM. Adding extra "purely metaphysical" entities to a theory, which don't >> correspond to anything that appears in the mathematical formalism of the >> theory itself (which would apply to things like a "true present" or to >> hidden variables in QM), seems a bit like postulating that there are >> invisible intangible elves sitting on each person's head which have no >> causal effects on anything we can measure; sure it's logically possible, >> but it seems like a very inelegant and arbitrary way for reality to work. >> >> The MWI is deterministic, however, and hence has hidden variables. > > But not "hidden variable" in the EPR sense. In the MWI, there are hidden > universes, they are not variable, but terms in the universal wave, and we > just don't know which terms apply to us. If it was hidden variable in the > EPR sense, then by Bell, they would be non-local, and you would conclude > falsely (like Clark) that the MWI has to be non local (which I doubt very > much). > > No, as I explained elsewhere, Bell's inequality rests on 4 assumptions, and the easiest assumption to remove is that time is asmmetric at the fundamental level (which *in any case* physics indicates it isn't, except for neutral kaon decay - which I dount has ever been used in an EPR experiment).
Locality and realism are almost certainly preserved, as Einstein suspected, even though Bell's inequality is violated. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
