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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

#151

Post by ammon »

fnord77 wrote: post #115
danbruc wrote: post #48

Earlier quoted context omitted.

The only difference in quantum physics is that there are actually two parallel universes: One in which you took out the red marble & one in which you took the blue one. You don't know what universe you're in until you look at the marble, but still it doesn't help you to transmit a message to your friend. I don't think it is helpful to talk about multiple universes, that makes a strong implication towards a many world…

in this example, what evidence is there that it works differently than in the classical case?

That's exactly what the article we're all commenting on is about!

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

#152

Post by joe_the_user »

danbruc wrote: post #136
joe_the_user wrote: post #116

Earlier quoted context omitted.

I don't think it is helpful to talk about multiple universes, that makes a strong implication towards a many world interpretation. You're correct but the point is "many worlds" or Copenhagen interpretation having no implications , they each describe the same mathematical/experimental results. They're just "ways to think about the results". They matter as much as whether you label the axes of a graph x and y or A and…

Even if they have no observable differences, they still make different metaphysical claims. If I see Schrödinger's cat alive, many world claims that there actually also exists a dead cat while Copenhagen claims that there is only one alive cat. You may argue that the differences are irrelevant for all practical purposes but you don't get to claim that there are no differences between different interpretations.

You may argue that the differences are irrelevant for all practical purposes but you don't get to claim that there are no differences between different interpretations.

It depends what one considers "significant differences". If I go from caring about the practical implications of an interpretation to some other implications, I could make all sorts of distinctions. Explanation X might be written in French and explanation Y might be written in Spanish. Even if one is a translation of the other, you could say they're different in various ways. Or maybe one explanation contains swear words and makes the reader feel bad and so the reader might not "like" that explanation.

But my point above is more specific. Since the two interpretations have the same practical implications, a practical prediction can't really "need" one interpretation - the other interpretation gives you the result. This is the point about all the hidden objects/states explanations have classical analogues.

And if we're getting metaphysical, Copenhagen doesn't say live cat or dead cat but says superimposed state.

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

#153

Post by tbabb »

danbruc wrote: post #138
tbabb wrote: post #91

Earlier quoted context omitted.

> that makes a strong implication towards a many world interpretation You say that like it's a shortcoming. :) There are many who take the (very reasonable) position that the many worlds interpretation is the most epistemologically parsimonious one. Contrary to some misunderstandings of it, it doesn't "add" extra worlds; it removes the concept of "wave function collapse", and leaves all the other known laws of quantu…

Contrary to some misunderstandings of it, it doesn't "add" extra worlds; it removes the concept of "wave function collapse", and leaves all the other known laws of quantum mechanics completely unchanged. Yes, it gets rid of the collapse postulate, but no, it actually introduces many worlds. You can wiggle a bit around, claim that prior to the wave function collapse there are also many worlds in Copenhagen or whatnot,…

it actually introduces many worlds

No, this is the misunderstanding that I'm talking about.

The extra "worlds" follow directly and exclusively from the existence of the various basis states in a wave function, and the laws of entanglement. No other postulates are needed.

Before the measurement/entanglement, the system and environment are independent, and can be written (|0> + |1>) ⊗ (|0> + |1>). After the entanglement, the wave function of the universe can no longer be factored that way, and the system and environment are in a joint state of |00> + |11>. The |00> and the |11> are the multiple "worlds", they show up— in both interpretations— whether you want them to be there or not.

Copenhagen doesn't want them to be there, so it says that one of the |00> or |11> goes away... at some point... because [waves hands and mumbles]. Many worlds merely declines to do this, and that is legitimately the only difference between the two.

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

#154

Post by lazide »

archibaldJ wrote: post #94
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…

But aren’t these “informations” just representations of (something abstract) reflected in a bunch of quantum states of your neurons? And we humans decide there are homomorphisms between mine and yours and thus they are representing the “same informations”. But really they were fundamentally different. There are no copying. Only some kind of lossy compression mimicking.

At that point you would need to decide what ‘copying’ is, exactly. Making a terrible VHS recording of a TV show would still be considered copying by most, even if none of the relative pixels ever matched.

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

#155

Post by lisper »

serverholic wrote: post #146
lisper wrote: post #40

Earlier quoted context omitted.

Only if you can completely isolate the balls so their states don't decohere. That is not practically possible to achieve, particularly since in your scenario you reach into the bag and touch the balls. As soon as you interact with the balls in any way, you become entangled with them and the behavior of the system becomes classical.

You didn't add anything to his example. This is just purely to be pedantic.

No. The only way you can actually observe entanglement is in an isolated entangled system (this is the reason quantum computers are hard to build). It is true that at a philosophical level there is no difference, but from the point of view of physics, which is to say, what is observable, isolation is crucial. Non-isolated systems behave classically, notwithstanding that they are actually quantum systems.

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

#156

Post by dntrkv »

UncleOxidant wrote: post #124
joe_the_user wrote: post #113

Earlier quoted context omitted.

There are no propositions that "we are in simulation" would imply (unless someone fundamentally lacks imagination). Being "in a simulation" doesn't imply that we're in simulation created by later humans, it doesn't give any indication how fine-grain the approximations are, etc. etc. "We're in a simulation" fundamentally discard Occam's Razor in the fashion of the belief in God as controlling everything. And thus this…

It's kind of interesting how people who would never consider a creationist explanation seem quite willing to embrace the idea that we're in a simulation.

Well, in my case, I don't believe our universe is a simulation, but I'm open to discussing the idea for fun and it does seem like a possibility. Whereas, most people that believe in creationism, believe it 100% to be the case and if you don't believe the same you are going to hell. I grew up in an evangelical Christian community and you can't really compare the two groups. Evangelicals are ready to die for this belief.

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

#157

Post by Kranar »

feoren wrote: post #130
Kranar wrote: post #66

Earlier quoted context omitted.

Fair enough we'll simply disagree on that. Entanglement is not a property about wave functions and really has nothing to do with waves. It's a logical consequence of the uncertainty principle and was ironically deduced by Einstein, Rosen, and Podolsky (EPR Paradox) as a way to argue that quantum mechanics is an incomplete description of physical reality. Being that it's strictly a consequence of the uncertainty princ…

While I believe that entanglement is genuinely something new and interesting, your explanation of it simply feels like a semantic difference. There is no way in which the universe you describe would be different from a classical universe, at least up to the limits of your description. I'm simply "not allowed" to say that one of the balls is red and the other is blue, before I've looked? It's just, what, against the l…

OPs explanation is that entanglement is when there is a red ball and a blue ball and when you know which ball is red, you determine that the other ball must be blue.

My explanation is that entanglement is when there is no red ball or blue ball, there are simply two balls and the color of both balls is both red and blue simultaneously. It's not simply that one ball is red, the other is blue, but we don't know which one is which until we measure them. It's that fundamentally there is no red ball and blue ball, there are just two balls whose colors are in a superposition of red and blue.

I will try to come up with an observable difference but it's hard to do so with colors because the typical examples used for entanglement involve properties that can cancel one another out, so that two entangled particles exhibiting a superposition of two properties will, after many trials, end up forming some kind of destructive or constructive interference that would not be possible if those two particles were in a definite state.

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

#158

Post by naasking »

feoren wrote: post #135
naasking wrote: post #126

Earlier quoted context omitted.

One is an assertion with no logic to justify it, the other is an assertion with a somewhat persuasive argument justifying it [1]. They are simply incomparable. [1] https://www.simulation-argument.com/simulation.html

Of the 3 assertions in the abstract, the obviously false one is #2: "Any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history". When you realize that running a simulation of the universe requires more processing power than is available in the universe, this is very obviously false. I respect people who believe in a bearded White omnipotent homophobic Go…

> Of the 3 assertions in the abstract, the obviously false one is #2: "Any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history". When you realize that running a simulation of the universe requires more processing power than is available in the universe, this is very obviously false.

I think you've expressed a number of confusions.

First, I think you contradicted yourself. The line you quote says that posthuman civilizations are unlikely to create simulations, but you say this is false because a universe simulation requires more power than available in the universe. So you're agreeing with the outcome while saying you're disagreeing.

Second, I suggest reading the the paper fully, because Bostrom explains that we don't need full universe simulations, we need only consciousness simulations (kind of like the Matrix). The very premise of a post-human civilization is that they have knowledge sufficiently advanced that they have algorithms to simulate human minds.

Much like how video games only render the part of the world that is visible to the players, so a consciousness simulation only needs to simulate minds and their perceptions of a macroscopic, classical world, they do not have to simulate a full quantum universe. Our brains are great at filling in information that we expect to be there, so even the parts that we directly perceivedon't need to be simulated with complete fidelity.

Frankly, I don't think you've given the argument sufficient thought, but by a happy accident you picked exactly the outcome that I think is most likely, and I elaborate on why here:

https://higherlogics.blogspot.com/2021/02/why-we-are-likely-...

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

#159

Post by lazide »

UncleOxidant wrote: post #144
naasking wrote: post #126

Earlier quoted context omitted.

One is an assertion with no logic to justify it, the other is an assertion with a somewhat persuasive argument justifying it [1]. They are simply incomparable. [1] https://www.simulation-argument.com/simulation.html

But how is the simulation hypothesis not positing a "god" of some sort (some kind of super-intelligence that they claim is behind it all)? It seems like the simulation hypothesis is a theistic hypothesis. Or do they assume the simulation just evolved? Also, why the assumption that post-humans are running the simulations (as in the paper)? Couldn't it be any ultra-advanced civilization that's playing with an evolution…

If a simulation exists, and there is evidence of it, then sure we could surmise that someone created the simulator - and would have some evidence of such?

I think the parent poster was noting that it is a pretty fundamentally different argument than say, positing the existence of a creator, because we exist at all - and that said creator has certain specific requirements of us regarding what we do on Sundays, for instance, or with whom and when we have kids.

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

#160

Post by lazide »

eigenket wrote: post #131
tick_tock_tick wrote: post #96

Earlier quoted context omitted.

The speed of light is the exact kinda of constant a programmer would add to a system to solve problems.

But quantum mechanics is exactly the opposite of what a programmer would add. At least as far as we understand it is (exponentially) harder to simulate quantum systems than classical ones.

Sure, using systems built from inside the system. In said theoretical world, they may have different constraints and physics after all. (Only kinda serious)

Practically, the simulator theory may be testable, but probably not. Every religion I’ve run across is pretty clearly not okay to even test.

So that’s progress maybe?

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