I How can Bohmian mechanics explain entanglement?

[Nugatory]

It is perfectly tenable, even if not proven yet, for each particle to have local hidden variables and yet as soon as one of them is measured, a superluminal signal being sent to influence the other particle. It would result in the same empirical observations in QM.

It is perfectly tenable - if you are willing to give up relativity. That is a very heavy lift, only marginally less heavy than “Perpetual motion is perfectly tenable, if we give up thermodynamics”.

It is possible to keep relativity and Bell’s theorem, just not in a way that satisfies your sense of how the world ought to work.

 

[sahashmi]

Ahh…. No physical theory does that. Consider even something as solid as Newtonian gravity: dig into it a little bit, ask why there should be an attractive force between masses and what is really going on to pull two masses towards one another and you’ll find that there is no answer. Appealing to GR doesn’t make the problem go away, it just leaves us wondering what is going on that causes stress-energy to curve spacetime, and for matter what is this spacetime that is curving.
The lack of a “complete picture” bothers most people more when it comes to QM, but if probe the objections you will find that the theory isn’t more deficient than others, but rather that it is much harder to reconcile with our intuition about how things “ought” to work.

Gravity is propagated through gravitational fields which are much more easily imagined and the theory of GR is much more “complete” than quantum mechanics. There’s a reason the second is initially perceived as more weird and it’s not because of faulty intuitions.

Quantum mechanics posits non local correlations without any influences at all. It’s arguably a form of “action at a distance” like the original Newtonian gravity. Of course, that ended up being wrong and proven to be incorrect. The same will probably happen with QM

 

[sahashmi]

QM tells us (almost) everything that can be said about QM, that is, about the quantum regime. If you want QM to do more than that, the problem is yours.

Physical theories are designed to give us clues about reality and help us understand what’s going on and how to connect perceived measurable outcomes to things happening in the world when we’re not measuring. Your argument is effectively circular and no different from gibberish. A theory about goblins tells me everything about the goblin regime too.

 

[sahashmi]

It is perfectly tenable - if you are willing to give up relativity. That is a very heavy lift, only marginally less heavy than “Perpetual motion is perfectly tenable, if we give up thermodynamics”.

It is possible to keep relativity and Bell’s theorem, just not in a way that satisfies your sense of how the world ought to work.

It is easy to give up relativity once you realize that you cannot explain the non local correlations without giving it up. Any kind of superluminal causation requires a preferred reference frame and people like maudlin, and bell, people who’ve put more thought into this than 99% of physicists, think that some form of non local causation is inescapable.

If you keep relativity, there is no reason for why one particle should be correlated to another at a distance. Appealing to an abstract mathematical equation doesn’t actually explain anything. It’s just a description. I can write an equation down describing how two coins land on the same side every time, but this does not tell me why or how they do. The same applies to quantum correlations. There is a reason why eminent scientists like Einstein and Bell thought this doesn’t make sense, and yet somehow, so many physicists are arrogant enough to think that they were just “thinking about it the wrong way.” Any time someone says anything nonsensical, they can resort to the same kind of argument you just made: “you just have to think about this differently. Your intuitions are mistaken.”

This attitude by physicists reminds me of god believers. “You just don’t understand god. He exists outside of space and time and yet magically still affects the physical world. Don’t ask further questions please.”

 

[Sambuco]

It is perfectly tenable, even if not proven yet, for each particle to have local hidden variables and yet as soon as one of them is measured, a superluminal signal being sent to influence the other particle. It would result in the same empirical observations in QM.

If we try to mantain the notion of causation, the question arises about what is the cause and what is the effect, which becomes observer-dependent. There are other hints to reject the notion of fundamental causation, such as the time symmetry of fundamental physical laws (https://quantum-journal.org/papers/q-2021-08-09-520/).

And no, current QM doesn’t do everything a physical theory should do: it doesn’t give us a complete picture of what’s going on.

There exists a possibility that everything that happens is exactly what QM predicts: the appearance of certain correlated discrete events at spacetime points without a "cause". Some information-based interpretations favored this position, such as Rovelli's relational quantum mechanics (https://link.springer.com/article/10.1007/BF02302261). It's difficult to accept this view without good justification, which is why many people are working on what is known as the quantum reconstruction program, attempting to derive the entire mathematical apparatus of QM from a few well-motivated physical principles.

Lucas.

 

[PeterDonis]

Entangled particle measurements are no different from stochastic coins always ending up tossing to the same side.

Yes, they are. The latter cannot violate the Bell inequalities. The former can.

 

[PeterDonis]

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[Nugatory]

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