Undergrad Is Nature Non-Deterministic Due to Nonlocality in Quantum Mechanics?

[msumm21]

From what I understand, the most reasonable explanation of the violation of the Bell inequalities is that nature is non local. If we accept this, is there a reasonable argument that nature is not deterministic? I.e. could it be that the probabilistic predictions from QM are just averaging -- if we knew all the non local information, all the history of all the particles that interacted with particles that interacted with particles that ... interacted with the measured particle we could precisely predict results? I realize the latter may be impractical to experimentally test, but can it be theoretically ruled out?

 

[DrChinese]

From what I understand, the most reasonable explanation of the violation of the Bell inequalities is that nature is non local. If we accept this, is there a reasonable argument that nature is not deterministic? I.e. could it be that the probabilistic predictions from QM are just averaging -- if we knew all the non local information, all the history of all the particles that interacted with particles that interacted with particles that ... interacted with the measured particle we could precisely predict results? I realize the latter may be impractical to experimentally test, but can it be theoretically ruled out?

No, in fact there is a viable interpretation of quantum mechanics that is much as you imagine. It is call Bohmian Mechanics. It is explicitly nonlocal, and is deterministic. However, due to a lack of complete knowledge of initial conditions, it is not possible to make a deterministic prediction of quantum outcomes.

 

[Nugatory]

is there a reasonable argument that nature is not deterministic?

(The rest of your post reads as if you have an extra negative. Did you mean "nature is deterministic"?)

The discussion is somewhat sterile unless and until we have a proposed candidate theory to evaluate... But based on what we know so far, there is no reason to exclude determinism or non-determinism.

Bell's results are somewhat of a red herring here, as the observed results could conceivably be the result of (what you're calling) statistical averaging across either a deterministic or a nondeterministic underlying theory. Bell's results tell us that that hypothetical theory must be non-local, but apply equally whether it is deterministic or not.

 

[msumm21]

Thanks. Any idea what would win (determinism or non) if the experts in the field were to vote? Is there a majority favoring one over the other? If so, is there a good reference explaining why?

 

[PeterDonis]

Any idea what would win (determinism or non) if the experts in the field were to vote?

Science is not done by majority vote. It's done by doing experiments to test theoretical predictions. Until we have a deterministic vs. a non-deterministic theory that includes our current quantum mechanics as an approximation, we have no way of testing determinism vs. non by experiment.