On 25-11-2024 23:21, Bruce Kellett wrote:
On Tue, Nov 26, 2024 at 12:16 AM smitra <[email protected]> wrote:
On 24-11-2024 05:04, Bruce Kellett wrote:
If QM were intrinsically local, then you would be able to give
this
local account of the correlations.
You are manifestly unable to do this.
It's obvious from the time evolution specified by the local
Hamiltonian.
You have tried this approach before. You seem unable to realize that
that is just a restatement of your position. And it is that position
that is in question. Restating your conclusion is not an argument or
an account of anything.
You are disputing a triviality, namely that we have a unitary time
evolution specified by a local Hamiltonian:
U(t) = exp(-i H t/hbar)
At least that's what you are claiming. What you are really doing is that
you play hide and seek in the complexity of this. Your real bone is, of
course, with the idea that time evolution is unitary and that there is
no collapse. Obviously, the only plausible reason QM could be non-local
is if there is a real collapse. If everything always stays unitary with
the unitary transform specified by a local Hamiltonian then there is no
collapse, and everything always stays local. That doesn't mean that you
can't have states with non-local properties, what it means is that
whatever happens always follows from applying local laws. Sol, non-local
features can be explained using common cause effects propagated by local
unitary dynamics.
Invoking authorities to get a simple fact about Bell's inequalities
cleared up, i.e. that it does not imply that QM is non-local, is
quite
appropriate.
You have to make sure that you quote authorities that actually know
something.
https://news.harvard.edu/gazette/story/2007/11/sidney-coleman-dies-at-70/
"Nobel Prize winner and former Harvard colleague Steven Weinberg, now
professor of physics and astronomy at the University of Texas, said, “I
always thought that Sidney Coleman understood modern theoretical physics
better than anyone else. "
You made the extraordinary claim that Bell proved that QM
is non-local, which is plain nonsense.
If it were nonsense, you would be able to give a clear demonstration
of a local account of the Bell correlations. This you have repeatedly
failed to do, so I call out your nonsense.
It's trivial as I explained above.
If it were true, then you
wouldn't have professors with deep knowledge of QM claiming that QM
is local.
Not everyone gets it right. People who believe in MWI tend to claim
that QM is local, but then, usually only in the context of the theory
of many worlds. They, too, have never been able to establish this. If
they had, you could give this argument. But even then, Bell's theorem
proves beyond any doubt that there are inequalities that any local
theory must satisfy. Experiment, as well as QM, shows that these
inequalities are violated. Indeed, Clauser, Aspect, and Zeiling were
recently awarded the Nobel prize for establishing this fact. QM has
been shown to be necessarily non-local.
Yes, it invokes unitary QM with the unitary time evolution specified by
a local Hamiltonian. This implies a MWI scenario, but not per se with
all the baggage of splitting worlds that are supposed to split in
independent ways. You end up with different sectors that are entangled.
Bell's theorem doesn't prove that QM is non-local. If that were the
case, then this would be just another of QM that would be proven in any
QM textbook, and it would make unitary QM specified by a local
Hamiltonian inconsistent. The whole debate about e.g. black hole
information loss wouldn't happen in that case. The fact that this is a
hot topic in theoretical physics proves that you
don't really understand the subject matter you are debating here. It's
true that QM could be non-local but that's not implied by Bell's
theorem. If you were right on this point, then that would imply that all
theoretical physicists get this wrong and you are one of the few people
who knows better. So, clearly not a matter of "Not everyone gets it
right", rather that everyone else but you is getting it wrong, and that
makes it appropriate to invoke an argument from authority pointing that
out.
And b.t.w. if there is a Bell's theorem purely about unitary QM that
doesn't invoke hidden variables, you could just state it right here. You
didn't do that and made the counterclaim against me when I pointed out
that Bell's theorem is about inequalities for certain correlations
satisfied by local hidden variable theories, which is common knowledge.
And I made the remark that it's then a theorem about local hidden
variable theories, not QM, so it's relevance to QM is limited to the
ideas that QM might have an underlying hidden variable theory. You are
disputing this only on your say so, so basically an argument from
authority where the authority is you, not even references to the works
other experts in the field.
Saibal
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 [email protected].
To view this discussion visit
https://groups.google.com/d/msgid/everything-list/CAFxXSLTW%2BRc5Zo47qrbyfHgkPgdzHnOeLwQvFx%2BpKPmJsc1-Jg%40mail.gmail.com
[1].
Links:
------
[1]
https://groups.google.com/d/msgid/everything-list/CAFxXSLTW%2BRc5Zo47qrbyfHgkPgdzHnOeLwQvFx%2BpKPmJsc1-Jg%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 [email protected].
To view this discussion visit
https://groups.google.com/d/msgid/everything-list/fb2e8ec1e79a7ca2d39a2a7581f8ad60%40zonnet.nl.
