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Re: [Phys-L] Quantum measurement problem



ICYMI ... Physics Today is out with another article on Quantum
Measurement. Teaser, plus blog comments:
https://physicstoday.scitation.org/doi/10.1063/PT.3.5046

Full article:
https://doi.org/10.1063/PT.3.5046

I'm not sure what to make of it. It gives an overview
of various approaches, but it's more a catalog than an
in-depth review of the pros and cons.

In particular, it doesn't push me off my opinion that
when it comes to "interpretations" of QM, that which
interprets least interprets best. That is, the equations
tell you what happens.

Also I'm sticking with my analogy to Newtonian gravity.
The Newtonian law tells us /what/ happens, but does not
tell us /why/ or even /how/. It does not tell us how
the gravitational force is conveyed from place to place.
For nearly 250 years (1666 to 1915) this was the best
we could do. Even now, for high-school physics purposes
and a verrry wide range of other purposes, that's good
enough.

QM is a black box that tells us what happens. When we
try to find out /how/ it happens, i.e. when we try to
look inside the black box, we get burned.

We are allowed to worry about this, but we are not
required to worry about it.

I rather like the Feynman quote:
theories can be formally equivalent but psychologically different.

We can apply this to the Everett interpretation.
Carroll suggests that if all paths in Borges's
garden of forking paths are possible, then an
unlikely path is just as good as any other. IMHO
that's a misinterpretation of the interpretation.
That's because you can keep notes of all the forks
that brought you to today, so if an improbable event
occurs you know it's improbable, based on your notes,
based on the statistics you have collected.