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

quantamagazine.org

11–20 of 356 posts

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

#11

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?

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

#12
post #3

If we were in a simulation, would the speed of light be the processing speed of the universe as each area re-renders, and spooky action at a distance be two variables pointed to the same memory location, populated with a lazy-loaded value, with copy-on-write semantics? edit: seems like it is lazy loaded, so revised my summary.

If we were in a simulation, it feels overzealous to make the assumption that the computing model would be anything at all like what've developed. Best assumptions you can make is that it follows some kind of consistent logic (though there's caveats here, too).

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

#13
post #3

If we were in a simulation, would the speed of light be the processing speed of the universe as each area re-renders, and spooky action at a distance be two variables pointed to the same memory location, populated with a lazy-loaded value, with copy-on-write semantics? edit: seems like it is lazy loaded, so revised my summary.

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 single biggest disconnect between the wave function and classical reality because the nature of our (classical) existence is fundamentally intertwingled with copying (classical) information. It is happening right now even as you read this. Information is being copied out of my brain onto the internets and into your brain. At the same time, all our cells are busily copying the information in our DNA, and so on and so on.

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

#14
post #3

If we were in a simulation, would the speed of light be the processing speed of the universe as each area re-renders, and spooky action at a distance be two variables pointed to the same memory location, populated with a lazy-loaded value, with copy-on-write semantics? edit: seems like it is lazy loaded, so revised my summary.

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?

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

#15
post #12
post #3

If we were in a simulation, would the speed of light be the processing speed of the universe as each area re-renders, and spooky action at a distance be two variables pointed to the same memory location, populated with a lazy-loaded value, with copy-on-write semantics? edit: seems like it is lazy loaded, so revised my summary.

If we were in a simulation, it feels overzealous to make the assumption that the computing model would be anything at all like what've developed. Best assumptions you can make is that it follows some kind of consistent logic (though there's caveats here, too).

> that the computing model would be anything at all like what've developed

Perhaps. I suspect, though, that it would be subject to the same information theoretical constraints which would provide convergent evolutionary pressures.

It seems at least likely that some level of optimization would be useful if there is any type of cost (energy, materials, resources, space) to the computing substrate, whatever that may be, and that would lead to similar optimizations to what we might be able to imagine.

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

#16

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?

I've quoted it before but I will again just because I hate superdeterminism so much:

First, the logical flow: Bell’s theorem proves that no local, realistic theory can reproduce the predictions of quantum mechanics. It does so by considering a very specific situation of entangled particles being measured by spin detectors set at different angles. Critically, the angles of these spin detectors are assumed to be set independently from one another. ...

Experimenters have tried to ensure independence for all practical purposes with elaborate techniques: independent quasi-random number generators running with different algorithms on different computers are one very basic example. On more advanced experiments, they use quantum sources of randomness, and try to make sure that the choice is only made once the particles are in flight.

The trouble is that in principle, there will always be a point in the past at which mechanism used for the angle choice, and the mechanism used to produce the entangled particles were in causal contact with one another. (If all else fails, then the early universe will provide such a point.) The super-determination thesis says that any past causal contact can in principle provide correlation between the settings of the two detectors (or the detectors and the properties of the particles), and is the source of the violation of Bell’s inequality.

Here’s a deliberately ridiculous example. Once the particles are in flight, I throw in the air a box of Newton’s notes on alchemy. I select the one that falls closest to my feet. I roll two dice, and use them to select a random word from that page. I match the word with its closest equivalent in Caesar’s commentary on the Gallic wars, or the Iliad, or the complete works of Dickens, my choice of work depending on the orientation of the Crab pulsar at the moment of measurement. I use the word position in these works to select a number in this book A Million Random Digits (take the time to read the customer reviews). And I use this number to set my detectors. I repeat this for my other measurement runs, but I substitute in Dan Brown’s Da Vinci Code for Dickens every third go.

Superdetermination advocates would tell me that there is in principle a causal connection between my throwing the papers in the air, Newton, Caesar, Dickens as they sat down to write 300, 2000, and 150 years ago, the Crab pulsar and the RAND corporation’s random digit selection. And that it’s possible that these things have conspired (unknowingly) to make sure that my detector settings and a particle’s spin measurement is correlated in a particular way in my lab in a law-like way.

I can only reply that yes, it’s possible. I cannot prove it wrong. But I can find it unreasonable. And I would be tempted to call these people philosophically desperate.

https://www.quora.com/Why-do-some-crackpot-scientists-go-aft...

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

#17

> 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

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

#18
Note that there is a very important property of entangled particles that is hardly ever mentioned in this kind of exposition, which IMHO casts a lot of light on what is really going on, and that is that entangled particles do not self-interfere the way non-entangled particles do. For more details see:

https://flownet.com/ron/QM.pdf

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

#19
post #3

If we were in a simulation, would the speed of light be the processing speed of the universe as each area re-renders, and spooky action at a distance be two variables pointed to the same memory location, populated with a lazy-loaded value, with copy-on-write semantics? edit: seems like it is lazy loaded, so revised my summary.

Cellular automata have a built in speed limit, so it could be something like that. If one cell's state depends on only its immediate neighbors state, then logically no object can move faster than one cell diameter per frame. And if you had shared state between two non-adjacent cells in certain limited cases, that could create "faster than light" behavior.

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

#20
post #13
post #3

If we were in a simulation, would the speed of light be the processing speed of the universe as each area re-renders, and spooky action at a distance be two variables pointed to the same memory location, populated with a lazy-loaded value, with copy-on-write semantics? edit: seems like it is lazy loaded, so revised my summary.

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 entangled quantum waves would behave.)

> Among the fundamental differences is the fact that classical information can be copied but quantum states cannot be cloned.

The no-cloning theorem says that there exists no universal quantum machine that can perfectly clone an arbitrary quantum state. However, that does not preclude a machine that can imperfectly clone any quantum state, or machines that can perfectly clone some but not all quantum states [1]. (Clearly the information transferred to my brain is not a perfect copy of your brain's state, and your DNA is not perfectly copied every time.)

[1] https://arxiv.org/abs/quant-ph/9607018

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