What do violations of Bell's inequalities tell us about nature?

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What do observed violation of Bell's inequality tell us about nature?

  • Nature is non-local

    Votes: 10 31.3%
  • Anti-realism (quantum measurement results do not pre-exist)

    Votes: 15 46.9%
  • Other: Superdeterminism, backward causation, many worlds, etc.

    Votes: 7 21.9%

  • Total voters
    32
  • #276
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Properties are just predicates, ‘attributes,’ ‘qualities,’ ‘features,’ ‘characteristics,’ not the reality itself.
Properties can be treated as variables no different from X and Y and used to indicate whatever you want, but if it isn't useful its of questionable value.
 
  • #277
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The wave function, at least for people who think (following Bohr) that the wave function provides a complete description of (microscopic) physical reality. It's true, there are people who don't think the wf in ordinary QM should be understood as a beable, as corresponding to some physical reality. The question for them is: what, then, does?
I thought this was an interesting paper in trying to answer this difficulty, a difficulty that was also pointed out by Maudlin that the authors believe they can answer:
Following Jeff Barrett (1999), we define a theory to be empirically incoherent in case the truth of the theory undermines our empirical justification for believing it to be true. Thus, goes the worry, if a theory rejects the fundamental existence of spacetime, it is threatened with empirical incoherence because it entails that there are, fundamentally, no local beables situated in spacetime; but since any observations are of local beables, doesn't it then follow that none of our supposed observations are anything of the kind? The only escape would be if spacetime were in some way derived or (to use the term in a very general sense, as physicists do) 'emergent' from the theory. But the problem is that without fundamental spacetime, it is very hard to see how familiar space and time and the attendant notion of locality could emerge in some way...at least without some concrete proposals on the table...

Suppose then that as far as many quantum theories of gravity are concerned, in various ways, familiar spacetime is not admitted at the fundamental level, putting quantum gravity in violation of Maudlin's dictum, and threatening empirical incoherence. In the next section, we will consider a range of such theories, and observe that the seriousness of these challenges depends a great deal on what they postulate instead of spacetime. Different theories leave more or less of the standard structure of spacetime intact, and so understanding our observations may, in the best case, require only a relatively small shift in our conception of local beables. But we will also see that in theories in which little or nothing of spacetime is left in the fundamental ontology, it still may be the case that the question of deriving some formal structure that mirrors local beables can be answered rather more readily than one might expect. In the final section we will turn to such derivations and address Maudlin's argument that such formal derivations never show that local beables are part an emergent ontology.
Emergent Spacetime and Empirical (In)coherence
http://lanl.arxiv.org/pdf/1206.6290.pdf

Slide presentation:
http://workshops.aei.mpg.de/philQG/Nick.pdf [Broken]
 
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  • #278
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I thought this was an interesting paper in trying to answer this difficulty, a difficulty that was also pointed out by Maudlin:
Pointed out by Maudlin? Does that mean he accepts that they have defused his worries?
 
  • #279
825
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Pointed out by Maudlin? Does that mean he accepts that they have defused his worries?
Sorry, I changed it so it doesn't appear that it was a Maudlin quote. And I'm not sure if Maudlin accepts it, but I doubt it, although he acknowledges in some of his work that he may come to change his view, with time. But again, that's just my interpretation of his writings/videos.
 
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