(November 23, 2021 at 8:49 pm)HappySkeptic Wrote:(November 20, 2021 at 3:38 pm)Klorophyll Wrote: You probably should've mentioned that this is only one possible interpretation of quantum mechanics. John Bell showed that, in theory, there can be hidden determinism behind the curtains, that sets up how things should play out, giving room to manoeuvre for the theist. It's only when the hidden variables are local that they conflict with the predictions of QM.
Polymath has spoken to this already. From Wikipedia:
Quote:For a hidden-variable theory, if Bell's conditions are correct, the results that agree with quantum mechanical theory either (a) appear to indicate superluminal (faster-than-light) effects, in contradiction to relativistic physics, or they (b) require superdeterminism. (Or, technically, a combination of both, though no known example of this exists.)
In superdeterminism, the observer becomes part of the experiment, and free-will is impossible. For non-local hidden variable theories -- they involve far more complexity than normal Quantum Mechanics. An arbitrary high-dimension Hilbert space is used to describe something that can never be measured. It is the ultimate fudge-factor.
As for your problem with there being no quantum realism - I don't have an issue with it. Realism is an emergent property, not a fundamental one. There is a "measurement problem" in QM that we sidestep when we talk about the emergence of real histories.
The Bohmian interpretation gives a non-local and deterministic version of QM that works in a classical setting (non-relativistic). It is, however, significantly more complicated than standard QM and almost no working physicist uses it. Philosophers seem to like it, though.
One big problem with it, though, is that it doesn't have a nice relativistic formulation. So, QCD is a quantum field theory that has both positrons and electrons interacting with photons. Crucially, it deals with the spin of the particles (which is (mostly) a relativistic effect) and particle-antiparticle annihilation. There is no generalization of Bohmian mechanics that can handle those two facts of life. Things get even worse for Bohmian mechanics when things like isospin and the strong and weak force come into play.
The upshot is that there is no known relativistic version of QM that is also deterministic. In that sense, Bell's comments about *old* QM are simply out of date.