New Slant on the EPR-Bell Experiment

TL;DR

This paper explores the implications of Bell's Theorem by comparing EPR-Bell experiments with other quantum cases involving timelike measurements, questioning the assumption of nonlocality and proposing alternative explanations.

Contribution

It presents two new options for understanding correlations in quantum experiments, challenging the conventional view of nonlocality in EPR-Bell scenarios.

Findings

Correlations in timelike and spacelike measurements may share explanations.

Action-at-a-distance might be more widespread in quantum mechanics.

The orthodox view of nonlocality in EPR-Bell experiments is less certain without further arguments.

Abstract

The best case for thinking that quantum mechanics is nonlocal rests on Bell's Theorem, and later results of the same kind. However, the correlations characteristic of EPR-Bell (EPRB) experiments also arise in familiar cases elsewhere in QM, where the two measurements involved are timelike rather than spacelike separated; and in which the correlations are usually assumed to have a local causal explanation, requiring no action-at-a-distance. It is interesting to ask how this is possible, in the light of Bell's Theorem. We investigate this question, and present two options. Either (i) the new cases are nonlocal, too, in which case action-at-a-distance is more widespread in QM than has previously been appreciated (and does not depend on entanglement, as usually construed); or (ii) the means of avoiding action-at-a-distance in the new cases extends in a natural way to EPRB, removing action-at-a-distance in these cases, too. There is a third option, viz., that the new cases are strongly disanalogous to EPRB. But this option requires an argument, so far missing, that the physical world breaks the symmetries which otherwise support the analogy. In the absence of such an argument, the orthodox combination of views -- action-at-a-distance in EPRB, but local causality in its timelike analogue -- is less well established than it is usually assumed to be.