Does entanglement violate special relativity?

Dmitry67

I mean the topic subject is incorrect.
When people say 'entanglement violates SR' they mean FTL -> causality problems.
But in fact (I agree with you) there is no such violation, even the entanglement is discussed in that context over and over again

P.S.
I understand that you hate MWI, but just curious, what interpretation do you like?

debra

Lets set a simple scenario:
Lets first of all make an empty 3D space about the size of the Universe. Into which we will place two particles. We want to study SR and entanglement using real physical classical objects.
Is that OK or is it illogical in some way?

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nikman

Lets set a simple scenario:
Lets first of all make an empty 3D space about the size of the Universe. Into which we will place two particles. We want to study SR and entanglement using real physical classical objects.
Is that OK or is it illogical in some way?
Someone like (say) Max Tegmark might say it's not coherent. He maintains that physical existence began with (1) a specific, defined set of initial conditions and (2) something like the Schrödinger equation to determine future evolution (within the probabilities associated with both the SE and classical complexity).

So, a thought-experiment of your kind posits a kind of scale separation and may be a simulation fallacy. It's a computationalist abstraction. Can you really separate those two particles and their behavior from the complete history of the universe? And how would you incorporate that into the model?

nikman

Also, maybe a more practical consideration: GR takes the Universe to be in part a function of the total matter-energy it contains. Could you have "an empty 3D space about the size of the Universe" if the Universe is only two particles?

So you scale down. Make it a Universe of a size appropriate to a Universe of only two particles. Would that be equivalent?

DrChinese

Gold Member
He maintains that physical existence began with (1) a specific, defined set of initial conditions and (2) something like the Schrödinger equation to determine future evolution...

...Can you really separate those two particles and their behavior from the complete history of the universe?
Max Tegmark is a Many Worlder, I think. He has written articles on parallel universes. Addressing your comments:

1. From a factual viewpoint, this does not appear to be accurate based on what we currently know. There are parts of the universe that have never been in causal contact with us. And the part that has is constantly changing - i.e. is not static.

2. Further, there is a powerful virtual particle field that we are immersed in. Clearly, these particles are affecting us. Are virtual particles evolving according to these same deterministic laws?

I don't think you are saying that you are advocating a deterministic viewpoint, but I just wanted to get clarification.

nikman

Max Tegmark is a Many Worlder, I think. He has written articles on parallel universes. Addressing your comments:

From a factual viewpoint, this does not appear to be accurate based on what we currently know. ... There are parts of the universe that have never been in causal contact with us. ... Are virtual particles evolving according to these same deterministic laws?

I don't think you are saying that you are advocating a deterministic viewpoint, but I just wanted to get clarification.
He's a "many-minder" along with Dieter Zeh. Same difference as far as I can tell, and then some.

He stated the initial conditions bit explicitly, and probably not for the first time, in his 1996 paper "DOES THE UNIVERSE IN FACT CONTAIN ALMOST NO INFORMATION?" which he still links to from his website. No alteration, no repudiation. We can assume he at least doesn't consider it outmoded.

Causal contact isn't the issue, apparently. It's all about universal entanglement. It seems deeply deterministic (in the sense that the Schrödinger equation is deterministic) but not I think as uncompromisingly deterministic as 't Hooft's determinism. The randomness component seems to be genuinely quantum stochastic, not some hidden pseudo-randomness originating down at the Planck length amid the foam.

Tegmark's pal Dieter Zeh's analogy (he uses it as a metaphor for teleportation) is the Grimm's tale "The Hare and the Hedgehog". Mrs. Hedgehog at the top of the row, Mr. Hedgehog at the bottom, unpacking their pre-arranged plot. No causal contact between them, pure kinematics, just the hare running back and forth until he drops dead. I guess that's the universe, unpacking itself per initial conditions evolved through an algorithm.

There's a Deutschian component there too, the Universe as Computer, common to almost all many-whatevers. I've never understood why you'd need all those universe-worlds to store information. If you want to go total informationalist I like Hans C. von Baeyer's peeled-grape uncollapsed qubit. It's all in there, right here in this unparalleled world-universe, all the goodies anyone could ever want, if we could only decipher it. But we can't. "All we get is one lousy [classical] bit," as von Baeyer says.

No, I don't buy the Tegmarkian universe. But would I stake my life on its being bogus? No.

So, re: debra's idea: I do believe in the possibility of larger domains of entanglement beyond simply that of any two or three or however many defined correlated particles. Entanglements within entanglements, correlation sets within correlation sets. So the actions of any entangled pair wouldn't necessarily just be reflective of their own immediate correlations. But maybe you'd only discover that if you were actually able to isolate the particles, as in a hypothetical two-particle universe. Also it seems like a two-particle universe wouldn't be equivalent as a relativistic entity to the one we know. So at the moment I'm inclined to think the idea may have problems.

Dmitry67

There's a Deutschian component there too, the Universe as Computer, common to almost all many-whatevers. I've never understood why you'd need all those universe-worlds to store information. If you want to go total informationalist I like Hans C. von Baeyer's peeled-grape uncollapsed qubit. It's all in there, right here in this unparalleled world-universe, all the goodies anyone could ever want, if we could only decipher it. But we can't. "All we get is one lousy [classical] bit," as von Baeyer says.
Max Tegmark denies it, he says that we are NOT emulated and no computer is need

nikman

Max Tegmark denies it, he says that we are NOT emulated and no computer is need
Okay. I know he says that every true mathematical statement gets physically realized in some universe within the multiverse, so there must be at least one universe in which Turing Machines can't exist due to conflicts with other conceivable mathematics. He says that, more or less anyway, in one of his papers.

I tend to conflate him with Nick Bostrom sometimes. Their relationship goes all the way back to Sweden and they've written at least one paper together. Bostrom is notorious for pushing the idea that we may well be living in a computer simulation. Any material you can cite where Tegmark specifically disputes that approach would be appreciated.

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