Bell's theorem

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Bell's theorem

[′belz ‚thir·əm]
(quantum mechanics)
A theorem which states that any hidden variable that satisifies the condition of locality cannot possibly reproduce all the statistical predictions of quantum mechanics, and which places upper limits, for the predictions of any such theory, on the strength of correlations between measurements of spatially separated objects, whereas quantum mechanics predicts very strong correlations between such measurements.
References in periodicals archive ?
For this reason the EPR paper appears legitimate from a rational point of view, although in fact wrong from a physical point of view; indeed a separate theoretical tool, the Bell inequality [7], was necessary to evidence the inconsistency of the EPR attempt [8, 9] : the predictions of local realism on which is based the Bell inequality conflict with the results obtained in various experiments, e.
In principle one could not exclude that the wave function, from which is extracted all physical information allowed about the quantum systems, could actually contain hidden variables; indeed this chance, reasonably suspected in the famous EPR paper, has been excluded later thanks to a separate theoretical tool only, the Bell inequality.
At this point, the exposition brings unavoidably into the mind the Bell inequality.