[nocoolnametom]

When you say superdeterminism are you referring to something like Pilot Wave theory, where what appear to our measurements as probabilistic yet random interactions are merely expressions of a more complex yet non-random underlying system that we cannot, as yet, measure? (I don't even know if that's the proper description of the hypothesis.)

[xmcqdpt2]

Superdeterminism is simply the idea that all quantum experiments results could have been known before performing them, assuming a perfect knowledge of the state of the universe.

It's one of those things that could be true and explain all of QM but also is kind of a cop out. "Of course your two detectors are giving correlated results, they were tightly coupled 13.8 billion years ago and now they are forever linked like all things."

[consilient]

> Superdeterminism is simply the idea that all quantum experiments results could have been known before performing them, assuming a perfect knowledge of the state of the universe.

That's just determinism. Superdeterminism additionally posits that the results of those experiments are all correlated so as to make it appear to us as if local hidden variable theories were false. Pick the settings on two polarimeters for a Bell-type experiment by measuring the spins on photons emitted 10 billion years ago from two different galaxies, and you'll find (or rather, won't find, because it's being hidden from you) that they were arranged, long before the Earth was formed, just so as to trick you. The universe is conspiring against us, and the whole scientific project is a farce.

That, or superdeterminism is false.

[zmgsabst]

Alternatively, non-local correlations (in the style of anyons) persist from the early universe.

And we’re just measuring those.

[zmgsabst]

How is it a cop out?

We know two things:

- universe was small enough everything was tightly coupled

- non-local phenomena occur

Insisting that our beliefs reflect an ideology (eg, you can segregate off portions of reality to study in isolation) which seem contrary to observed reality (eg, the points above) is religion — not a scientific investigation of the universe.

[xmcqdpt2]

Superdeterminism sidesteps interpretational questions by arguing against reductionism, which is pretty much the core of all physics. Where is this hidden information stored? What causes the specific outcomes in a destructive measurement?

To say that QM is in fact a local hidden variable theory because everything was once touching billions of years ago, without positing any mechanism for it is a cop out.

At least instrumentalism admits that there are interpretational questions, even if we don't need to answer them.

[zmgsabst]

Not just because it was touching:

- because it was touching;

- and because we observe non-local information stored in braiding of the wave equation; even when we separate the constituent (quasi)particles.

The belief that you can reduce a system by decoupling a particle or system from outside influences is at odds with that second fact. We’re storing the hidden variables in those non-localities; when you measure a system where both particles are part of a non-local phenomenon, they’re coordinating through that non-locality.

What has literally no proposed mechanism is suggesting such non-local quasiparticles disappeared — by what specific mechanism did primordial anyons dissipate?

[GoblinSlayer]

>- non-local phenomena occur

No. Also superdeterminism doesn't have non-local phenomena. The idea is that measurements are predetermined to look like quantum.

[drdeca]

First, as a religious person: no, contrary to what you seem to be saying, dismissing superdeterminism isn't "religion".

Second, dismissing superdeterminism is not, as you seem to say, "contrary to observed reality".

The belief that one is capable of forming ideas that bear any resemblance to reality, is justified on account of, in order for one's beliefs or lack-thereof to have any use, it would have to be true.

Things like the no-speed-up theorem (which I admit I'm not super familiar with), and other things of that sort, lead me to expect that, while I don't have a full argument for this, that it isn't possible for computational complexity reasons, for the early universe to be such that it, in effect, encodes predictions of what future measurements people will make, in a way that makes signals determining what measurement directions get used, correlated in the way that superdeterminism requires.

[zmgsabst]

Except that, we know such macro correlations exist — for the two reasons I outlined.

We know that the universe was once highly correlated, due to its size, and we know that such correlations form super-macro structures, from galaxies to filaments. We further know that knots in the wave equation are a non-local phenomena, such as with anyons. The minimal assumption is that any particle we encounter is part of such a non-local phenomenon.

To assume that we can isolated regions of reality uncorrelated to those two phenomena is to assume an ideological belief, unsupported by evidence.

That you didn’t discuss my actual objection to dismiss it with generalities is very telling.

[GoblinSlayer]

Superdeterminism is fine tuning, not a mere correlation. A mere correlation is hidden variables theory.

[bowsamic]

Superdeterminism is a loophole in Bell's theorem that allows local hidden variables, so there could just be a fully deterministic theory that determines everything, including your detector settings in advanced. Classical physics has generally assumed that we at least have free choice to choose what to measure. If we don't, we can trivially retain classical gravity