The discussion centers on the relationship between entanglement in quantum mechanics (QM) and deterministic theories, particularly in the context of interpretations like Bohmian Mechanics. Participants highlight that deterministic interpretations, such as those allowed by Bell's theorem, are inherently non-local and do not imply instantaneous effects. The Schrödinger equation is emphasized as a deterministic mechanism for entanglement, with Bohmian mechanics providing a clear framework for understanding particle behavior without direct interactions. The conversation underscores the complexity of reconciling classical mechanics (CM) with quantum phenomena.
PREREQUISITESPhysicists, quantum mechanics students, and researchers interested in the foundations of quantum theory and the interplay between determinism and entanglement.
But aren't QM interpretations which are suppose to be deterministic claim to explain QM.anuttarasammyak said:
The experimental evidence shows that locally realistic theories are impossible. Any realistic interpretation of QM, such as Bohmian Mechanics, is non-local. There is a universal pilot wave that enables correlations at a distance - or, at least, that's what it amounts to.selfsimilar said:
Deterministic theories (in the sense of having still some hidden variables that determine everything) that are allowed by Bell's theorem are non-local theories (or superdeterministic theories but usually these not very scientific).selfsimilar said:
Same question for Newtonian gravity. It is deterministic and the force acts at a distance. How does the Sun affect instantaneously the planets, which are millions of miles away?selfsimilar said:
Deterministic interpretations do not necessarily imply instantaneous effects. See e.g. superdeterminism or many-worlds.selfsimilar said:
To my knowledge that is why general relativity was invented and it says gravity is not instantaneous.martinbn said:
That was my complaint. Not only that, but non of the interpretations show any thing remotely as to the deterministic mechanism for entanglement.Morbert said:
I don't follow. Even if a deterministic interpretation does not imply instantaneous action at a distance, entanglement still obtains, and would be explained by dynamics and earlier conditionsselfsimilar said:
That's not true. Bohmian mechanics gives a deterministic mechanism for entanglement. The key part of this mechanism is the Schrödinger equation, which is deterministic.selfsimilar said:
There are no such things, so there is no reason for a theory to have to explain them.selfsimilar said:
Demystifier said:
in the sense of evolution . But not the particle position. Otherwise we would not have this discussion.Demystifier said:
particle position is still determined by the magical guiding wave which amounts to a postulate but does not give clear mechanism how particles affect each other.Demystifier said:
In Bohmian mechanics, which is what @Demystifier was talking about, particle positions do evolve deterministically.selfsimilar said:
That plus the initial particle positions, yes. Note the bolded word.selfsimilar said:
In Bohmian mechanics, particles do not affect each other directly. There are no particle-particle interactions.selfsimilar said:
Would you say that Newtonian gravity gives a clear mechanism how particles affect each other?selfsimilar said:
certainly not, not even general relativity. QFT particle interaction I have some sympathy for, like the "virtual particle" and intuitive concept of momentum. But QM and interpretations are really awkward, that is why there is so much talk about them, just seems something missing. I am hoping for a theory that is constructed in such a way that all aspects of QM are emergent and related by a fundamental concept and so non-locality is one such important aspect/result, then such theory can be truly considered the right interpretation. And if Gravity falls out of it so much better and some fundamental constants would be icing on the cake. Ok, forget about the last two requestsDemystifier said:
.I agree. I am familiar with the general concept.PeterDonis said: