[Fourier864]

So the article says "quantum mechanics is incompatible with local hidden-variable theories".

Hidden variable theory is what you were describing initially. It basically says that there must secretly be deterministic rules to quantum mechanics, and that the randomness we observe is just due to our ignorance of some "hidden variables". Einstein was a fan if this theory because he believed "God doesn't play dice".

John Stewart Bell discovered that quantum mechanics would actually behave a little bit differently if there were secretly variables out there, and proposed experiments that would show if there were hidden variables or not.

The 2022 nobel prize was awarded because these experiments were finally completed, and they showed conclusively that there were no hidden variables in quantum mechanics.

[moralestapia]

>quantum mechanics is incompatible with local hidden-variable theories

>local

That's an important modifier.

>The 2022 nobel prize was awarded because these experiments were finally completed, and they showed conclusively that there were no hidden variables in quantum mechanics.

Nah, from the same article:

"The exact nature of the assumptions required to prove a Bell-type constraint on correlations has been debated by physicists and by philosophers. While the significance of Bell's theorem is not in doubt, its full implications for the interpretation of quantum mechanics remain unresolved."

[Fourier864]

Conclusively was probably too strong of a word, as there are technically still two ways to get hidden variables to work:

1) If we allow information to be non-local, i.e. we allow information to travel instananeously. Allowing this would just be such a hit to the foundation of theories like relativity and quantum field theory that most physicists don't really believe this could be an explanation. These theories rely on nothing traveling faster than the speed of light.

2) We could allow for "superdeterminism". One of the assumptions of Bell's theorem is that a researcher is free to choose any measurement they'd like, independent of the particle they're measuring. However, if the universe correlated everything from the Big Bang onward, a.k.a "superdeterminism", then the researcher is actually NOT capable of choosing a measurement independently of the particle. Everything is pre-scripted from the initial conditions of the Big Bang. If I go and measure a photon from the CMB (the earliest light in the universe we can measure), superdeterminism implies that this photon emitted 14 billion years ago somehow "knows" exactly how it'll be measured in 14 billion years, and has hidden variables that ensure it won't contridict my measurements or quantum theory. This seems to open a whole can of worms about the feasabilty of all scientific experiments, and it doesn't actually make any predictions about the randomness anyhow.

Out of curiosity I went digging to see if there were hard numbers for what physicists believe, and I found a 2011 poll from a conference about the nature of quantum mechanics. Surprisingly none of the respondents believed that random quantum events have some sort of underlying determinism. I'm not saying you should always follow the crowd, but it, combined with all the laboratory testing of the Bell inequality, shows that your initial statement "randomness is an incorrect interpretation of quantum mechanics" is not something you'd say to a group of physicists without having very compelling and detailed reasons to back it up, because it's very much a fringe idea. The majority of physicists subscribe to theories of quantum mechanics that don't involve hidden variables, and treat the randomness as inherent to theory.

Link to the poll if you're interested: arxiv.org/abs/1301.1069. I'm talking about question 1.

[GoblinSlayer]

Those numbers suggest that 36% don't believe in fundamental randomness. And that's given the status quo that interpretations are philosophy not worth to think about so people are indulged to believe in random stuff, add to this cognitive inertia due to education largely following Copenhagen, and 64% doesn't look like a very big number. Just how implausible must be Copenhagen to lose 36% in such comfy conditions?

[Fourier864]

But the other 3 results are that the randomness is "irreducible", which I'm assuming means we can never actually get rid of the randomness. And smaller portion believe that randomness is just apparent, which I'm assuming they're referring to Many Words interpretation. Neither of those gets you to determinism from our perspective though.

They actually ask later in the poll which interpretation is their favorite (Q12) and 42% pick Copenhagen. But the only deterministic one on that list is the pilot wave theory, and that got a 0. Some did pick "other", so that might include something deterministic, but based on the results of Q1 I'm assuming not.

[GoblinSlayer]

Irreducible, but not fundamental? If randomness doesn't exist, how your perspective matters? And why do you think ignorance can't be fixed? That's an antiscientific claim.

[moralestapia]

Bell's theorem tells you that if some hidden variable is involved it has to be non-local. That's it. Period.

It doesn't tell you there are hidden variables involved or not. Whether light travels fast or not. Whether there's determinism or random chance involved. It's only an if clause, if you may; but a very important one, I'm not detracting from it. Please take time to understand that.

>These theories rely on nothing traveling faster than the speed of light.

There's a lot of phenomena that could be perceived as "faster than light" (i.e. a shadow's projection) and yet they aren't. Information should also not travel faster than light, that put an end to many entanglement paradoxes out there that seemed to imply faster than light travel from a first glance.

If a hidden variable is involved, there could be a not-yet-understood part of the system that allows for it to work in spite of this apparent non-locality.

Does the Bell theorem tell us that? No. Do I know the answer to that? No. Do you know the answer to that? No. No one knows. Hence why I wrote, yesterday,

>A deterministic process being behind it cannot be ruled out (yet?).

[GoblinSlayer]

Incompatibility with hidden variables doesn't imply randomness. Hidden variables theory doesn't assert mere determinism, it's a stronger assertion that particles must be classical.