Entanglement and Quantum Nonlocality Demystified

TL;DR

This paper challenges traditional interpretations of quantum nonlocality, arguing that Bell Inequalities are based on incompatible probabilistic models and that quantum correlations do not imply nonlocality, emphasizing the importance of contextuality.

Contribution

It clarifies the misconceptions about quantum nonlocality, demonstrating that Bell Inequalities cannot be proven when local variables are properly considered, and redefines the understanding of quantum correlations.

Findings

Bell Inequalities rely on incompatible probabilistic models.

Quantum nonlocality is better described as quantum contextuality.

Proper inclusion of local variables invalidates Bell Inequality proofs.

Abstract

Quantum nonlocality is presented often as the most remarkable and inexplicable phenomenon known to modern science which was confirmed in the experiments proving the violation of Bell Inequalities (BI). It has been known already for a long time that the probabilistic models used to prove BI for spin polarization correlation experiments (SPCE) are incompatible with the experimental protocols of SPCE. In particular these models use a common probability space together with joint probability distributions for various incompatible coincidence experiments and/or conditional independence (Bell's locality). Strangely enough these results are not known or simply neglected. Therefore so called Bell's or quantum nonlocality has nothing to do with the common notion of the non-locality and it should be rather called quantum non-Kolmogorovness or quantum contextuality. We quickly explain the true meaning of various Bell's locality assumptions and show that if local variables describing the measuring instruments are correctly taken into consideration then BI can no longer be proven. Of course we do not question the usefulness of the long range correlations characterizing the entangled physical systems in the domain of Quantum Information. However one should not forget that the anti-correlations cannot be perfect, that the wave function should not be treated as an attribute of the individual quantum system which can be change instantaneously and that the unperformed experiments have no results.