This is a philosophical question. It deals with the physics that raise this question. I cite the very recent article by Philip Goff in Scientific American which explains its relevance.

Bell’s theorem involves a set of inequalities that must not be broken if there are variables within entangled particles that determine properties of those particles in a determined state. Since the predictions of quantum mechanics break these conditions and inequalities, it is proposed that local, hidden variables cannot explain the results we see.

There is a relation here to quantum entanglement and the free will theorem of Conway and Kochen. Quantum entanglement has been cited as an example of consciousness at the quantum level by panpsychists. Some panpsychists further argue that panpsychism is not idealism or anti-realism, but a form of realism involving the matter-consciousness nature of reality.

Crucially, this all depends upon the assumption that the properties the particles hold are independent of measurement and how we measure things. But what justification do we have of making this assumption? After all, at least intuitively, if there was a world in reality that was dependent on measurement, it would surely be in the micro scale where perhaps the very act of measurements themselves may introduce hidden variables

If we cannot rule out measurements (of any kind) not affecting these proposed variables, then how can we rule out local, hidden variables? This seems like a pretty massive, and yet seemingly unjustified, assumption to make.

I would recommend reading panpsychists authors, such as William Seager, Philip Goff, Timothy Sprigge, and Annaka Harris.

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    If you are familiar with the question of hidden parameters and the context and statement of Bell's inequality it would be helpful to start your question with a precise introduction into this field. But possibly the whole subject is better discussed at Physics SE.
    – Jo Wehler
    Nov 7, 2023 at 13:07
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    I agree with Jo, this is not a philosophical question.
    – Olivier5
    Nov 7, 2023 at 13:19
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    @thinkingman I think you will get much better answers on Physics SE - you're getting into pretty technical territory here
    – Annika
    Nov 7, 2023 at 14:00
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    Have voted to reopen, because I don't thinj they will discuss the philosophical implications of realism & localism & challenges to them there. This is absolutely a topic for philosophy, even though it requires physics knowledge - just like the Measurement Problem
    – CriglCragl
    Nov 7, 2023 at 16:58
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    This question should remain closed because it does not demonstrate a sufficient understanding of the problem. The short answer is that if the "variables" are associated with the measurement devices, then the theory is non-local; a fact that is pretty clear if one is seriously engaged with Bell's theorem and related experiments.
    – Dave
    Nov 7, 2023 at 19:23

1 Answer 1


It's late, so I am tired and apt to make mistakes, but I think that even if the measurement devices are affecting the results of experiments (and by the way, they do), the difficulty with trying to explain entanglement that way is that two or more different sets of measuring devices would have to be affecting measurements in a precisely corrected way which is hard to account for in the experiments that have been performed. Entanglement has been demonstrated now at a distance of over 200km, and experiments have suggested that if the outcome of an experiment on one particle in an entangled pair is to affect the outcome of the other, then a signal would have to pass between the two at around a thousand times the speed of light. So either you can assume non-locality or some form of effect that propagates at a speed we thought was impossible. Admittedly that assumes that the measurements on the two particles are independent (ie that the two sets of measuring devices being used are not inadvertently correlated in some way to produce a misleading result) but I am happy to trust the experimentalists, who know far more about what they are doing than I do. TBH I also imagine that the various tests of Bell's inequalities, and the ramifications of them, have probably been studied to death by people much more clever and meticulous than I am, so I'm inclined not to bother second guessing them.

  • Yeah those are all great points. The correlation thing you just mentioned was something I thought of while also trying to sleep last night although at that time the question was still closed.
    – user62907
    Nov 11, 2023 at 2:05

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