On 8 January 2014 12:53, Jesse Mazer <laserma...@gmail.com> wrote: > > On Tue, Jan 7, 2014 at 4:35 PM, LizR <lizj...@gmail.com> wrote: > >> On 8 January 2014 08:59, Jesse Mazer <laserma...@gmail.com> wrote: >> >>> Well, most physicists already agrees physics is time-symmetric (well, >>> CPT-symmetric, but the implications are the same for Bell's inequality and >>> thermodynamics), >>> >> >> Yes, they do, but it doesn't appear to be taken into account when >> discussing Bell's inequality. >> >> >>> but I don't see how this alone can explain violations of the Bell >>> inequality. >>> >> >> No, you need to work out the consequences mathematically, and I dare say >> that is quite difficult. This is simply a *logical* demonstration that >> Bell's inequality can be violated while retaining locality and realism, >> which is otherwise impossible. >> > > As I said in another comment, if you allow information about the state of > complex systems like detectors to flow back in times as well as forwards, > it's not clear that this really counts as preserving locality. >
Nothing is flowing either way in time. (Assuming a block universe, nothing *can* flow in time - the notion doesn't make sense). What we have is a system with a state that is constrained by various boundary conditions. Physics is time symmetric at the quantum level, at least as far as the sort of system we're interested in is concerned (I think we're all agreed on this?) Therefore, both future and past boundary conditions may be involved in determining the state of the system. Locality is preserved so long as no physical objects travel faster than light. Consider an EPR experiment using photons. Nothing in the apparatus moves FTL. The state of the photons is constrained by boundary conditions imposed on their existence, i.e. between emission and absorption (we don't interfere with them in between, because this always wipes out the results we're looking for). If we assume time symmetric laws of physics then these boundary conditions are the state of the measuring devices, and the state of the emitter (see Brent's diagram). I don't have anything to say in response to the rest of your post, because it appears to be based at least partly on some faulty assumptions, for example the idea that information is flowing through time, plus what looks like a misunderstanding of the fact that the thermodynamic arrow of time arises at a higher level than that of individual photons. For example, your mention of "localised records of future events being harder to find" than records of past ones displays this mistake - all photons (and other fundamental particles) should include such records *in exactly the same number* as records of past influences, assuming time symmetry. This is arguably why quantum effects seem so weird, of course - because we don't expect future events to have an influence at the quantum level. -- 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
