Uncovering the Conceptual Catch in EPR Proposal for Non-Commutative Variables

[DrChinese]

EPR: No one really disputed that there are elements of reality. The question, as you mention, is whether they have simultaneous reality.

Bell: He showed that for QM to be correct in its predictions, there could not be such simultaneous reality - at least not without non-local influences.

Today: Of course, virtually any experiment with a Bell inequality defined is testing whether there can be simultaneous reality of non-commuting observables. All suitable tests fail in this regard, so there is NOT simultaneous reality of non-commuting observables.

 

[Adel Makram]

EPR: No one really disputed that there are elements of reality. The question, as you mention, is whether they have simultaneous reality.

Bell: He showed that for QM to be correct in its predictions, there could not be such simultaneous reality - at least not without non-local influences.

Today: Of course, virtually any experiment with a Bell inequality defined is testing whether there can be simultaneous reality of non-commuting observables. All suitable tests fail in this regard, so there is NOT simultaneous reality of non-commuting observables.

But where in Bell`s inequality, a simultaneous reality of non-commuting observables is measured? My understanding is; Bell`s-like experiments only test whether an objective reality with particles have a predefined physical values before the measurement determined by the hidden variables exists or no! So if they do exit, Bell`s inequality should hold, if the opposite then BI should be violated.

 

[RUTA]

But where in Bell`s inequality, a simultaneous reality of non-commuting observables is measured? My understanding is; Bell`s-like experiments only test whether an objective reality with particles have a predefined physical values before the measurement determined by the hidden variables exists or no! So if they do exit, Bell`s inequality should hold, if the opposite then BI should be violated.

Read this Mermin version of the BI http://users.etown.edu/s/stuckeym/MerminAJP1981.pdf or here https://www.physicsforums.com/insights/quantum-liar-experiment-instantiation-mermin-device/

 

[bhobba]

EPR showed that the Rules of Quantum Mechanics and the criterion of reality can not be both true which implies that quantum mechanics is not complete theory.

EPR showed that counterfactual definiteness and locality are not possible in QM - it actually had nothing to do with the completeness of QM although Einstein thought it did - but he was wrong.

Thanks
Bill

 

[DrChinese]

But where in Bell`s inequality, a simultaneous reality of non-commuting observables is measured? My understanding is; Bell`s-like experiments only test whether an objective reality with particles have a predefined physical values before the measurement determined by the hidden variables exists or no! So if they do exit, Bell`s inequality should hold, if the opposite then BI should be violated.

The inequality expresses the test by considering the relationship of outcomes at all permutations of 3 angle settings. Only 2 at any time are observed, a third is counterfactual. The inequality compares the averages of the permutations. If there is complete and total independence between Alice and Bob, that should be OK.