Monday, June 4, 2012

Explained by local deterministic processes

The 2010 Wolf Prize in Physics citation says:
The puzzling properties of entangled quantum states, first noted by Einstein, Podolsky and Rosen, who suspected that quantum mechanics is not a complete theory, were dramatically delineated by the remarkable work of John Bell. Bell showed that certain statistical correlations between properties of two physically separated particles, which were produced in an entangled quantum state, cannot be explained by any theory of local deterministic processes even if other unobserved properties (‘hidden variables') are allowed for.
None of this is correct. Entanglement was part of quantum mechanics before the 1935 EPR paper. Einstein got it from Popper's 1934 experiment. EPR was about uncertainty principle and completeness, not spin and determinism. More importantly, Bell's theorem only shows that quantum mechanics differs from certain local hidden variable theories. It says nothing about local deterministic processes.

The Wolf statement is like saying, "relativity experiments like Michelson-Morley show that light cannot be explained by any theory of space and time, even if the aether is allowed for. Well, no. Relativity explains Michelson-Morley and quantum mechanics explains spin entanglement.

Relativity does require some adjustments to your preconceptions about space and time, and quantum mechanics requires some adjustments to your preconceptions about hidden variables. If you refuse to make those adjustments, and insist on making your own assumptions, then sure, you will get some contradictions. That is what Bell and those Wolf Prize winners discovered. But they did not discover any experiments that cannot be explained by local deterministic processes.

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