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How Bell’s Theorem proved ‘spooky action at a distance’ is real

quantamagazine.org

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Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#21

Post by latenightcoding »

nobodyandproud wrote: post #11
dQw4w9WgXcQ wrote: post #6

Or Superdeterminism is true: https://en.wikipedia.org/wiki/Superdeterminism

Those objections to super determinism seem weak, or more along the lines of “I don’t like the implications, so I won’t consider it.” Genuine question: Would quantum computers work in any deterministic framework?

Gerard 't Hooft believes we would still have quantum computers faster than classical computers in a superdeterministic universe. However, the speedups would be more modest and factoring huge numbers in poly time would be out of the question

Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#22

Post by wizzwizz4 »

SV_BubbleTime wrote: post #14
someguyorother wrote: post #8

Earlier quoted context omitted.

It's not really immutable as you can change the parameters of an entangled pair. You just can't communicate any information by doing so, because you need a classical signal to make sure you don't read one of the particles the wrong way.

I could be WAY off, but if locality isn’t entirely true, and the “read success” is 33-67%, doesn’t that still leave quite a bit of wiggle room for communicating information in some fault tolerant method?

Nobody's ever managed it, the theory all says it's impossible, and that would violate several "known laws" of physics.

Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#23

Post by moedersmooiste »

latenightcoding wrote: post #21
nobodyandproud wrote: post #11

Earlier quoted context omitted.

Those objections to super determinism seem weak, or more along the lines of “I don’t like the implications, so I won’t consider it.” Genuine question: Would quantum computers work in any deterministic framework?

Gerard 't Hooft believes we would still have quantum computers faster than classical computers in a superdeterministic universe. However, the speedups would be more modest and factoring huge numbers in poly time would be out of the question

Unless you could build a classical computer on the Planck scale.

Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#24

Post by kolinko »

tylerhou wrote: post #20
lisper wrote: post #13

Earlier quoted context omitted.

That's not a bad analogy, but you have to be very careful here because no classical analogy can be a perfect fit for entanglement. The wave function is deeply and fundamentally different than our classical reality, and there is no way to reproduce its behavior classically. Among the fundamental differences is the fact that classical information can be copied but quantum states cannot be cloned. This is IMHO the singl…

A classical analogy for entanglement: suppose I have two balls in a bag. They are identical in every way, except one is red and the other is blue. I randomly grab one in each hand and show my hands closed. Now the states of the ball are entangled: as soon as you see the color of one ball, that "determines" the color of the other. (Not claiming that this is a perfect analogy, but I don't see where it diverges from how…

The analogy you mentioned is exactly the wrong one - it suggest that it’s just a matter of a hidden variable.

A proper (but less elegant) would be: you have two balls with the same color or a pattern.

You take one out. If you check the color first, you will find the other’s color the same, but the pattern sometimes different. If you check the pattern first, you will find the pattern the same, but the color sometimes different.

Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#25

Post by martincmartin »

willyg123 wrote: post #4

What is the prevailing theory to explain quantum entanglement? Must there be another dimension we cannot access or measure that is not subject to the laws of relativity? (I understand the laws of relativity break down at the quantum level but please ELI5)

Quantum entanglement falls out of the quantum mechanics, so in some sense, the prevailing theory to explain quantum entanglement is quantum mechanics.

Of course, it's unintuitive and unsettling, so you could generate other theories about other dimensions if you like. But as far as predicting the results of any experiments we can do, QM is all you need.

Also, there are two very different theories of relativity, the special and the general. Special relativity is taught in 1st year undergraduate physics, you really only need high school math & physics, plus an open mind, to understand it. This has E = mc^2, twin paradox, length contraction, time dilation, speed of light as a limit. It's actually a pretty small topic, it usually doesn't have a separate course because it wouldn't fill a one semester course. QM is fully consistent with Special Relativity.

The other is general relativity, which revises gravity in light of special relativity. This is a much bigger topic and typically taught in grad school, although there are some undergrad texts now that don't require math as advanced as the grad school ones. QM and GR are incompatible, and the search for a "quantum theory of gravity" is a key plank in any "theory of everything."

Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#26

Post by moedersmooiste »

dQw4w9WgXcQ wrote: post #6

Or Superdeterminism is true: https://en.wikipedia.org/wiki/Superdeterminism

I'm no expert but I also lean toward superdeterminism. It's either that or the universe is not deterministic at all. Believing that the universe is only partly deterministic is the same as believing someone can be partly pregnant.

Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#27

Post by nsxwolf »

I'll never understand entanglement. Every explanation makes me wonder why it can't be used to instantaneously send a message. I never fully understand the explanations why it can't be used to do so. I don't understand how you can be sure about the state of the other particle, what if someone already measured it and then did something to it?

Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#28

Post by wizzwizz4 »

eggsby wrote: post #17
miguelmurca wrote: post #2

> really permits instantaneous connections between far-apart location The phrasing in this article is tricky, as it wasn't FTL communication that was proven; just that there are correlations between things that would require FTL communication, were they classical processes. This is an important point: https://xkcd.com/1591/

One reason I often hear astrology is not taken seriously by the scientific community, as in findings like 'athletes often have aries rising on their birth chart' are ignored and not evaluated further, is because there is no empirical foundation for the communication of the effects. https://en.wikipedia.org/wiki/Astrology_and_science

There actually is empirical foundation for the communication of the effects![0] But the model is strictly simpler if you remove the astrology from it; astrology has no additional explanatory power, and its novel claims (claims not predicted by any other model) are wrong.

> Such children are more likely to be picked for school teams. Once they are picked, players benefit from more practice, coaching and game time — advantages denied to those not selected, who are disproportionately likely to be younger for their selection year. Once accounting for their biological age, the older players might not have been any better than later-born children when they are first picked. But after becoming part of a team, and being exposed to training and matches, they really do become better than later-born children who might be equally talented.

[0]: https://fivethirtyeight.com/features/why-athletes-birthdays-...

Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#29

Post by sergiotapia »

nsxwolf wrote: post #27

I'll never understand entanglement. Every explanation makes me wonder why it can't be used to instantaneously send a message. I never fully understand the explanations why it can't be used to do so. I don't understand how you can be sure about the state of the other particle, what if someone already measured it and then did something to it?

Reminds me of the in-lore comms system in Mass Effect. I think the comms in the ship were two atoms that were entangled, allowing instant messages no matter how many lightyears away the ship was from Earth.

Re: How Bell’s Theorem proved ‘spooky action at a distance’ is real

#30

Post by [deleted] »

nsxwolf wrote: post #27

I'll never understand entanglement. Every explanation makes me wonder why it can't be used to instantaneously send a message. I never fully understand the explanations why it can't be used to do so. I don't understand how you can be sure about the state of the other particle, what if someone already measured it and then did something to it?

[deleted]
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