Thursday, November 2, 2023

Bell inequalities are still poorly understood

Nicolas Gisin writes in a new paper:
On the conceptual side, the violation of Bell inequalities dramatically revolutionized our world-view. Interestingly, Newton’s theory of gravity was also non-local, even signaling.... In contrast to Newton’s non-locality, quantum non-locality is here to stay; the experimental evidence is clear on that point.
He complains that the Nobel committee does not agree with him:
Despite these beautiful experiments and the intellectually fascinating discoveries, Bell inequalities remained dismissed and poorly understood. Even to this day, the clear terminology non-local (equivalently, not-Bell-local) is too often blurred as not satisfying “local-realism”, as if non-realism was a way out [3, 4]. The fact is that assumption (1) is no longer tenable. As an example, consider the scientific background provided by the Nobel Committee [5]. A few lines after correctly presenting Bohm’s non-local hidden variable model, one reads that Bell inequality violation shows “that no hidden variable theory would be able to reproduce all the results of quantum mechanics”, contradicting the just cited Bohm model (which does predict violation of Bell inequalities). The correct statement is that no local variable theory is able to reproduce all results of quantum mechanics. And a few lines further, locality is defined as no-signaling - no communication without any physical object carrying the information, despite the fact that one of the main contribution of quantum information to the foundations of physics is a clear distinction between these two concepts. Next, realism is defined as determinism, even though Bell inequalities also hold in all stochastic theories satisfying (1). All this illustrates that Bell inequalities are still poorly understood by the general physics community. The 2022 Nobel Prize in physics allows one to hope that henceforth Bell inequalities will be part of all physics [courses].
I am with the Nobel Committee. The Bell inequalities told us nothing new. Bohm's theory is unphysical, and need not be considered seriously. Neither does any nonlocal theory.

I am not even sure quantum information is a worthwhile concept. Quantum cryptography and teleportation have not found any commercial uses.

I cannot find it, but there is a video clip of R.P. Feynman being asked about Bell's theorem. He dismisses it as unimportant. He says it was just a way of formulating what everyone already knew.

5 comments:

  1. Yeah, yeah, yeah, I love Feynman too, I have ever since he took a pin to NASA's bullshit balloon after Challenger went Kablooeey with just a glass of ice water and a piece of 'o-ring' in front of a live audience,

    BUT...Feynman was also known for his 'Feynman diagrams' which conveyed all sorts of information without being... you know... actual physics. He also did visualize what 'shall not be visualized' when he came up with his clock- turn method that seemed to put some actual predictable mechanics back into so called quantum mechanics. He also decried denormalization at one time of youthful blatant honesty, admitting it was a pea and shell game that wasn't really valid mathematically, since turning an infinite number into a finite number of any size you desire to get a workable result is complete and utter bullshit.

    C'est voila, from God's mouth to your ears.

    "The shell game that we play ... is technically called 'renormalization'. But no matter how clever the word, it is still what I would call a dippy process! Having to resort to such hocus-pocus has prevented us from proving that the theory of quantum electrodynamics is mathematically self-consistent. It's surprising that the theory still hasn't been proved self-consistent one way or the other by now; I suspect that renormalization is not mathematically legitimate."
    Richard P. Feynman
    "
    Feynman was rather...selective about when to admit the truth.

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  2. Dear Roger,

    People like Nicolas Grisin have been writing.

    They were writing even when I was applying for a PhD admission at the University of Pune (now half-admiredly and half-pompously called Savitribai Phule Pune University), during the 2002--2004 times, when all you Americans, through Times of India, were ``following'' me ``up.''

    While what happened at the UoP/SPPU might be of mild interest, what happened, back then, at arXiv is of even more interest. I've had USB 1 or 2 drives full of arXiv papers downloaded from 'net cafe's, just in case my PhD guide (potential or actual) or PhD examiner(s) (within 15 days of submitting my thesis, then 15 weeks, then 15 months, and still counting), would have to say (in both cases).

    What happened further, *after* my PhD, in Indian Academia is best left to ``Gogate'' graduates like Dr. Anil D. Sahasrabudhe and those of his ilk, especially from Pune/AICTE/UGC/etc.

    Coming to the paper you mention: Gisin [and people like him] doesn't [and don't] matter. [They never did.] My iqWaves theory does. That's the bottom line.

    Best,
    --Ajit

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    Replies
    1. Roger,

      Sorry, I might be mistaken a bit. ... You see, Anil didn't attend a ``Gogate'' college, merely the... errr... ``Basappa Veerappa Bhoomaraddi College of Engineering and Technology''.

      Not that the JPBTI Pramod ``Dr.'' Chaudhary (https://en.wikipedia.org/wiki/Pramod_Chaudhari) is going to do any better (looks like he is Anil's influencers' appointee to the Board), and not that details matter much while criticizing the likes of Nicolas Gisin, but still, one cares for those, if of empirical significance (where ``empirical'' doesn't mean that British idiotic streak of empiricism).

      I stand corrected. (But still, the connection to ``Gogate'' won't go away, somehow...)

      Best,
      --Ajit

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  3. I agree Roger. Unfortunately it seems commenting on Bell's theorem and its deep meaning had become a small cottage industry,despite there not being anything to the theorem that wasn't known in 1927.

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  4. Bell Inequalities are mere deck chairs compared to other things far more dysfunctional in physics.
    For one, the very model of how the atom functions is rubbish.
    Apparently the Strong Force has been shown to be the small fig-leaf kludge it is, it's been a matter of faith (for over 50 years and counting) not science for some time, poorly covering a structural mechanics that clearly isn't understood.

    https://www.wired.com/story/a-new-experiment-casts-doubt-on-the-leading-theory-of-the-nucleus/

    https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.130.152502

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