On 4 February 2014 13:32, Jesse Mazer <[email protected]> wrote: > On Mon, Feb 3, 2014 at 6:29 PM, LizR <[email protected]> wrote: > >> SR directly demonstrates block time via the relativity of simultaneity. >> This can be tested experimentally. >> > > The relativity of simultaneity is a claim about physics, not metaphysics. > Specifically, it's a claim that the laws of physics work exactly the same > in all inertial frames, which have different definitions of simultaneity. > If someone agrees that no frame's definition of simultaneity is "preferred" > in any physical sense, but that one is "metaphysically preferred" in a way > that is wholly invisible to all possible experiments, this would not > contradict SR or the relativity of simultaneity as a physical principle. >
OK, maybe what I should have said is that no one has come up with an explanation for the ROS that doesn't include the concept of space-time being a 4D manifold. I'm not sure if that leaves us with a physical or metaphysical problem (or maybe no problem at all!) > >>> 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. >> > > No. The Schroedinger equation which calculates wavefunction evolution in > QM is already fully deterministic, the MWI just dispenses with the extra > postulate of "wavefunction collapse" on measurement, which is the only > random element in QM. Determinism only implies hidden variables if you > assume each experiment has a *unique* outcome, and that this outcome is > generated in a deterministic way by the initial conditions. If you assume > that the physical state at the end of an experiment is a quantum state > that's a superposition of many possible classical results, then this can be > calculated from a prior quantum state using just the standard Schroedinger > equation. > > Well, yes, of course. The MWI is defined as QM with no collapse, and the SWE is deterministic, therefore we have realism....don't we? OK, I may have used the wrong terminology here. Maybe "hidden variables" means something different from what I thought. I assumed the MWI, being completely deterministic (a "block multiverse") had a definite state at all times, and that therefore there is stuff that we can't measure but is there, even so - which I thought meant hidden variables. But I may have messed up. (That said, time symmetry could also be termed hidden variables, I think?) -- 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.
