On Fri, Mar 4, 2022 at 10:30 AM Brent Meeker <meekerbr...@gmail.com> wrote:
> On 3/3/2022 9:05 AM, smitra wrote: > > On 03-03-2022 01:05, Bruce Kellett wrote: > > > In that case, if you believe that MWI is local, give me the local > account of Bell-type correlations of spin measurements at spacelike > separations. I will salute you if you can do this, because no one else > has ever managed in the past. Realism is completely beside the point. > > Bruce > > > It's trivial, as the dynamics is described by a Hamiltonian that only > contains local interactions. This mans that all non-local effects arise via > common cause effects. The creation of the entangled pair of spins happens > at some space-time point, so it's the result of local interactions. The > later when Alice and Bob each receive one of the two spins, *they get > correlated* with the spins they measure, because they and their > measurement gear consist of particles that evolve according to the > Schrodinger equation too and that evolution also only involves local > interactions. > > > You write "the get correlated", but breaking statistical independence > requires that the instrument settings be *already correlated* with the > spins before they interact with the instruments and Alice and Bob. That > could be thru some common cause, but it seems unlikely when the > polarization settings are determined by photons from many light years away > on opposite hemispheres of the cosmos. That implies a very long chain of > local interactions to the common cause. > Yes, I asked for a local account in many worlds theory of the correlations. Saibal did not mention many worlds; he merely referred only to some "common cause." Now any common cause for Alice's and Bob's measurements must come from some event or events where their respective past light cones overlap, and this might be arbitrarily far in the past. You are, therefore, in the realm of a superdeterministic theory, and this path does not amount to a local account in MWI. Bruce -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAFxXSLQZJzYEMWHvwHcFzzTZ2FbzGW46cDKk09cg%3Da7sAYs0fg%40mail.gmail.com.
