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Video# Causality and Local Determinism versus Quantum Nonlocality

Marian Kupczynski Austrian Academy of Sciences – FestsaalQuantum theory (QT), giving accurate predictions for the statistical distribution of outcomes obtained in physical experiments, is unable to predict which outcome and when will be observed. In spite of this it is often claimed that QT provides the most complete description of individual physical systems and that the outcomes of quantum measurements are produced in irreducibly random way.

According to statistical interpretation of (SI), which is free of paradoxes, QT does not provide the complete description of individual physical systems and might be an emerging theory from some more detailed deeper level description of the physical phenomena. In particular long range correlations predicted by QT for EPR type experiments and confirmed in spin polarization correlation experiments (SPCE) seem to “cry for explanation”. Searching for the intuitive explanation of these correlations Bell analyzed local realistic and local stochastic hidden variable models and found that these models led to inequalities (B-CHSH) which were violated by some QT predictions. Bell believed that no other local models were possible therefore the experimentally confirmed violation of B-CHSH has been incorrectly interpreted as a mysterious non locality of Nature and paraphrased sometimes as: ”two perfectly random dices tossed in two far away locations produce perfectly correlated outcomes”. Of course photons are not dices, correlations are not perfect and the confusion came from imprecise terminology and from the lack of understanding of the true meaning of probabilistic models used in various proofs of Bell and CHSH theorems.

The main assumption in these models was that all the results of different experiments performed in incompatible experimental settings can be always described using a unique probability space and some joint probability distribution. Several authors pointed out that this assumption was very restrictive and that it was inconsistent with the experimental protocols used in SPCE and this is the only reason why B-CHSH were violated. It seems also impossible that strongly correlated outcomes in SPCE are obtained in irreducibly random way because in this case the memory of correlations between physical signals created at the source would be destroyed. Therefore the probabilistic description of SPCE, consistent with QT predictions, has to depend explicitly on the context of each experiment. It has also to be deterministic in the sense that the outcome is determined by the supplementary parameters describing both a physical signal and an instrument in the moment of the measurement.

In the first part of my talk I will explain in some detail why B-CHSC can be violated and why their violation gives additional arguments that QT can be interpreted as an emerging theory respecting the causality and the local determinism on the microscopic level. Without the irreducible randomness on the microscopic level it is much easier to understand the existence of determinism and causality observed in natural phenomena not only in classical physics. If QT is emerging theory then in various time-series of experimental data there exist perhaps some fine structures not predicted before. If we find them we may even conclude that QT is not predictably complete. In the second part of my talk I will review some statistical tools which could help to achieve this goal.

M. Kupczynski, Entanglement and quantum nonlocality demystified, — AIP Conf.Proc. 1508.253 (2012).

M. Kupczynski, Time Series, Stochastic Processes and Completeness …, — AIP Conf.Proc. 1327.394 (2011).

M. Kupczynski, Is quantum theory predictably complete?, Phys. Scr. T135, 014005 (2009)

Easy access from : http://w4.uqo.ca/kupcma01/Bell.htm