- #36
ThomasT
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This is, at best, misleading. The correlations in optical Bell tests, without a certain interpretation of Bell's theorem, aren't 'curious' and are pretty much what would be expected via common cause in a universe governed by local causation. That is, the results of these optical tests are in line with established (local) optics principles.Stanford Encyclopedia of Philosophy said:The correlations in the EPR/B experiment strongly suggest that there are non-local influences between distant systems, i.e., systems between which no light signal can travel, ...
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The curious EPR/B correlations strongly suggest the existence of non-local influences between the two measurement events, and indeed orthodox ‘collapse’ quantum mechanics supports this suggestion.
Standard 'uninterpreted' QM doesn't posit a physical 'collapse' of a wave shell in real space and time. It just takes, per known optics, the polarization axis associated with either detection attribute and projects it to the other side so that you get, in the ideal, a cos2θ or a sin2θ dependency (depending on the process used to produce entangled pairs of photons) between the angular difference of the polarizers, θ, and the coincidental photon flux. Which is a result that's in line with established optics principles.
On the other hand, if you place certain (LRHV) restrictions on how a model of quantum entanglement can be formulated, then you get a correlation between θ and coincidental photon flux that in the extreme archetypal formulation of such a (LRHV) model you get a linear correlation between θ and coincidental photon flux. Which is a result that's at odds with established optics principles.
Again, to be clear, entanglement correlations, per se, don't suggest "nonlocal influences between distant systems".
As far as I'm aware, standard QM doesn't have any postulates involving nonlocality (ie., taking the term "nonlocality" to refer to some FTL physical transmission, or action-at-a-distance between entangled entities).Standard Encyclopedia of Philosophy said:... and indeed orthodox quantum mechanics and its various interpretations postulate the existence of such non-locality.
For clarification of where I'm coming from wrt this, refer to my post #27 in this thread.
And before we go any further it might help to go back to your first question in the OP:
Well, the information about the system is all that's known. There's no way of knowing if it represents anything beyond that (ie., how closely the constructions of QM approximate the reality underlying instrumental behavior).bohm2 said:Does the wave function represent the physical state of the system (MW) or merely our information about the system (orthodox interpretation)?
Thus, the mainstream, standard way of interpreting (or not interpreting, per Peres and Fuchs) QM is that it's a mathematical construction for calculating the probabilities of instrumental behaviors based on what's known about instrumental behavior. In other words, this is all that can be said about what the wave equation and wave functions are. Speculations about nonlocal influences, collapses, etc. aren't testable. Bell's theorem doesn't say that nature is nonlocal, it says that LRHV models of quantum entanglement are impossible. Why they're impossible is still a matter of debate, but, imo, it doesn't have to do with nonlocality in nature.
And without a certain interpretation of Bell, there's nothing to suggest physical nonlocal influences. Paraphrasing Peres and Fuchs: uninterpreted, or standard, QM is essentially local.
Unfortunately, the terms "nonlocal" and "nonlocality" have become part of the technical language and are a source of confusion, because in their technical usage wrt standard QM they don't refer to either FTL transmissions or action-at-a-distance. (See the quoted text from the paper referenced in post #34.)
Hence the conclusion that there's no tension between standard QM and SR.