Quantum entanglement

[Anonymous No.9007478]

So let me get this straight: 2 particles are created at the same time, and then when you later measure some property of one of them, you can use this to predict the outcome of a measurement of some property of the other particle. Why do people act like this is some super duper strange unintuitive concept? Clearly the values you're measuring were there all the time, from the moment the particles were created together, you just didn't measure them yet.

[Anonymous No.9007485]

>>9007478
No. Take spin, an unobserved system exists as a superposition of all possible spin states, then you observe one, and as soon as that collapses to a definite state the other also collapse to the corresponding state.

[Anonymous No.9007490]

>>9007485
>an unobserved system exists as a superposition of all possible spin states
But how do we know this is actually true, and it wasn't "secretly" in that final state already? You can't actually do a measurement where you observe all possible states, as far as I can tell.

[Anonymous No.9007502]

>>9007490
>But how do we know this is actually true, and it wasn't "secretly" in that final state already?
Bells inequalities.
>You can't actually do a measurement where you observe all possible states
You can't, but you don't need to.

[Anonymous No.9007519]

>>9007502
>Bells inequalities.
Been reading about this a bit, not sure if I'm convinced.
From wikipedia:
>Bell summarized one of the least popular ways to address the theorem, superdeterminism, in a 1985 BBC Radio interview:
>There is a way to escape the inference of superluminal speeds and spooky action at a distance. But it involves absolute determinism in the universe, the complete absence of free will. Suppose the world is super-deterministic, with not just inanimate nature running on behind-the-scenes clockwork, but with our behavior, including our belief that we are free to choose to do one experiment rather than another, absolutely predetermined, including the ‘decision’ by the experimenter to carry out one set of measurements rather than another, the difficulty disappears. There is no need for a faster-than-light signal to tell particle A what measurement has been carried out on particle B, because the universe, including particle A, already ‘knows’ what that measurement, and its outcome, will be.

I don't really see what's wrong with the concept of determinism that Bell dismisses here as obviously false. Disregarding quantum randomness, I might readily accept that everything, including human behaviour, is subject to determinism, so why couldn't we extend it to quantum mechanics itself, too?

[Anonymous No.9007522]

>>9007519
Bell is talking about superdeterminism. Which is dismissed, since it can't be tested.

[Anonymous No.9007535]

>>9007522
But neither can the assumption that quantum states actually exist be tested.

[Anonymous No.9007541]

>>9007535
That's what Bells inequalities are about.

[Anonymous No.9007554]

Superdeterminism seems the obvious answer. Whats with humans thinking they are so special? Brain is nothing but a machine that reacts according to physical stimulus

[Anonymous No.9007643]

>>9007554
I guess I'm misunderstanding the Bell theorem and it's not just an argument from free will, since in that case it would've just been dismissed by every well-thinking physicist.