Thursday, March 2, 2017

Paper repeats mistakes of Einstein and Bell

Belgium physicist Jean Bricmont writes:
History of Quantum Mechanics or the Comedy of Errors ...

Bohm’s theory was introducing “hidden variables”, meaning some unobservable quantities (hence, “metaphysical”) that are not part of the standard quantum mechanical description.2 Einstein had also favored the introduction of such variables in order to “save determinism”. The first objection to this idea is obvious: why bother with unobservable entities in order to satisfy a philosophical prejudice?

However, the definite blow against hidden variables was given in 1964 by John Bell who showed that, merely imagining that such variables exist leads to predictions that are in contradiction with those of quantum mechanics. Moreover, those specific predictions were later tested in laboratories and, of course, the observations came definitely on the side of quantum mechanics and against hidden variables. Case closed!

The goal of this paper is to show that all of the above is essentially false.
No, all those leading physicists are right and Bricmont is wrong.

The purpose of the hidden variable theories is to give a local classical explanation for quantum uncertainty. Bell's theorem and the subsequent experiments showed that was not possible. Mainstream physicists have understood this for decades, and textbooks explain this.

The Bell results do leave the possibility of nonlocal hidden variable theories like Bohm's, but they are much stranger than ordinary quantum mechanics, and harder to use, so there is no value in pursuing such ideas.

These are the facts. Bricmont quotes Hawking and various other respected physicists agreeing with them, but then tries to refute them with silly and misguided quotes from Einstein, Bell, and others who refused to accept quantum mechanics. More specifically, they refuse to accept non-commuting observables.

I am surprised that nonsense like this can get published. It is the equivalent of saying that relativity is wrong because of the twin paradox. Quantum mechanics is now 90 years old. Get with the program.

2 comments:

  1. Dear Roger,

    How about a ``hidden variable'' theory that is built with the purpose of producing a local and quantum explanation?

    BTW, I don't like the expression ``hidden'' variables. It feels too smirkish or condescending to any new theorization---good or bad, to even just the suggestion that QM theory may be incomplete (for reasons other than what, say, Einstein put forth).

    --Ajit

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  2. The Bell theorem and experiments do nicely disprove a certain class of theories, and the generally accepted name for those theories is "local hidden variable theories".

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