On 25-03-2022 01:29, Bruce Kellett wrote:
On Fri, Mar 25, 2022 at 8:55 AM Brent Meeker <meekerbr...@gmail.com>
wrote:
On 3/24/2022 1:33 PM, smitra wrote:
The account exists in the form of the unitary time evolution of
the state describing the entire system. This is local. It is your
assertion that unitary QM is nonlocal.
It's not local. It's evolving a wave-function which is a non-local
object. I get the feeling you are using "local" in some special
way.
Saibal insists that unitary evolution is local. Everything in QM is
governed by unitary evolution. Therefore everything is local. I have
pointed out one problem with this logic. That is that unitary
evolution depends on the Hamiltonian, and there is no quantum rule
that says the Hamiltonian must be local. The Hamiltonian is
constructed to fit the dynamics of the situation. If the situation is
intrinsically non-local, as for separated entangled pairs, then the
Hamiltonian must be non-local, and the description is non-local.
I explained in the other rely why this is false. The known fundamental
laws of physics are local.
The other problem with Saibal's account is that it is not peculiar to
many worlds. If all Hamiltonians are necessarily local, then this is
true for single world models as much as for many worlds. So the local
account of the violations of Bell inequalities must be available to
collapse theories as much as to Many Worlds theories. It is obviously
not the case that single world accounts are local. Going to many
worlds cannot make the explanation local.
It's not the case because collapse is not described by a unitary time
evolution based on a local Hamiltonian.
Saibal
I can see the _possibility _of MWI being local if somehow the
multiple worlds evolve thru some interaction where they overlap so
that their weights or numbers are adjust. But I don't see that this
interaction is in the Schroedinger equation. It seems even more
ad-hoc than wave-function collapse.
This is fanciful, since there is no possibility that an appropriate
dynamical model could be devised for such a scenario. I agree that it
is even more ad hoc than wave function collapse. There is no problem
with wave function collapse in epistemic interpretations. The collapse
just represents the advent of new knowledge. We have no trouble with
the collapse of possibilities in classical physics, or in ordinary
life. The problems people like Saibal see are all in their minds --
the problems with non-locality are not real.
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/CAFxXSLQc2h6kLHzUG-hDFRx-yS-1EPpqHGTBQaUwq77zriT3jg%40mail.gmail.com
[1].
Links:
------
[1]
https://groups.google.com/d/msgid/everything-list/CAFxXSLQc2h6kLHzUG-hDFRx-yS-1EPpqHGTBQaUwq77zriT3jg%40mail.gmail.com?utm_medium=email&utm_source=footer
--
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/17e03fb5063349e310c74d978f4318a3%40zonnet.nl.
