Maudlin is an expert on this subject, and he discusses in detail the work of von Neumann, Einstein, Bohm, Bell, and others saying that the concepts of locality, classical hidden variables, and quantum mechanics predictions are in conflict. One must be rejected.
What is not so clear is how Maudlin differs from textbook Copenhagen interpretation. Copenhagen says that the classical hidden variables are to be rejected. That is what von Neumann proved, under some assumptions. Then we have locality and predictions of quantum mechanics, with no problem.
Maudlin has some philosphical reasons for subscribing to classical hidden variables, so he ends up rejecting locality.
To me, no one has ever observed spooky action at a distance, so local theories are very much preferred. Bohm's pilot wave theory is crazy, because the theory is nonlocal, but all the observations magically turn out to be local.
Maudlin explains that all the great physicists rejected quantum nonlocality.
Tim: But they never straightforwardly acknowledged the nonlocality. And if you don’t believe that, 1:58:07 go read Bohr’s response to the EPR paper and see whether he straightforwardly says, “Yes, I believe in nonlocality. I believe in spooky action at a distance.” He denies it. ...I can explain it. The entire scientific enterprise for millennia has been to figure out cause and effect, by tracing events to nearby actions. If that is all wrong, and our lives are controlled by the spooky astrology of far-away stars, then we need to reconsider all the known laws of science.So I think Einstein saw correctly that if you accept this spooky action 1:59:25 at a distance, relativity itself is at risk. And he didn’t wanna put, you know, relativity at risk without good reason, and he couldn’t see any reason to accept the spooky action at a distance.
Now, he may not have liked it for other reasons. I mean, we, Newton didn’t like it, right? He says, he says, “No rational person would believe in it.” I mean, there are lots of people who find that just intuitively ugly or unacceptable or whatever. Curt: Mm-hmm.
Tim: And, and, and, and to this day, there are people who don’t wanna accept nonlocality, and they’ll more or less clutch at any straw to try to avoid it, as we’ll see. The psychology of that I can’t quite explain.
In fact, no such nonlocality has ever been discovered, and we can continue with what has worked for centuries.
Bell and Maudlin claim that all the great geniuses and textbooks are wrong. They have a belief in what a quantum theory ought to be, and they say that quantum mechanics, as understood by Bohr and von Neumann, does not qualify.
I agree with Newton. No rational person would believe in spooky action at a distance. Unless it is proved, of course.
