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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

#201

Post by joe_the_user »

IncRnd wrote: post #129
joe_the_user wrote: post #121

Earlier quoted context omitted.

You are using Occam's Razor incorrectly. A preference for parismony is not identical with parsimony being the only state of the world. "Everything is really under control of invisible stuff" make it impossible to use parisomy under any circumstances. It fundamentally discards Occam's Razor. Occam's Razor was invented by Friar William of Ockham as a defense of divine miracles. While I wouldn't personally accept a God…

> "Everything is really under control of invisible stuff" make it impossible to use parisomy under any circumstances. It fundamentally discards Occam's Razor. You are fundamentally misunderstanding Occam's Razor. It is not a law - Occam's Razor is a preference for how to view the world, not a law that was violated. [1] There are alternate rules-of-thumb, such as one by Ockham's contemporary, Walter Chatton. Chatton c…

You are fundamentally misunderstanding Occam's Razor. It is not a law - Occam's Razor is a preference for how to view the world, not a law that was violated.

Yes, Occam's Razor isn't a law but a method of understanding reality. My point is that if you throw out Occam's Razor in total, not in one or another situations, you're left with nothing to understand the world with.

The "God wants it that ways" and "because it's simulation" can be substituted for any proposition at all under any circumstances and there's not counter argument to such substitutions. This approach is also "the paranoid worldview" - "because they want to think that" also has this "insert everywhere" quality.

And you're link describing the original ideas of William of Occam doesn't what you'd imagine. "Occam's Razor" is broad approach that's evolved over time and just takes that label for convennience. Virtually no one is evoking the authority of William of Occam or claiming to follow his Nominalism or whatever. The generally means that adding unneeded hypotheses should generally be avoided. If you can never follow that guide, you're in trouble.

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

#202

Post by Kranar »

evanb wrote: post #120
Kranar wrote: post #46

Earlier quoted context omitted.

>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. This gets used to explain entanglement but it really has absolutely nothing to do with it. This is nothing that the ancient Greeks wouldn't have known. Not to p…

Just to be absolutely pedantic, "one of the balls is red and the other is blue" IS a statement you can make. However, it's surprisingly not equivalent to asserting (xor (and (red? 'left) (blue? 'right)) (and (blue? 'left) (red? 'right))) That is, "one is red and one is blue" does not mean that it's the case that either has a definite color. In terms of oft-used Bell pair states to demonstrate what I'm talking about,…

Your level of pedantry is warranted and I agree with it.

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

#203

Post by unparagoned »

Kranar wrote: post #150
serverholic wrote: post #145

Earlier quoted context omitted.

I think you're having a pedantic moment. Nobody claimed that the red/blue ball example was some big unsolved mystery. It's merely to give people a taste of entanglement in a way that your average person can understand. Isn't it true that if you entangle two particles, separate them, then measure one it'll tell you something about the other particle? That's all the example is trying to communicate.

>Isn't it true that if you entangle two particles, separate them, then measure one it'll tell you something about the other particle? Yes that's true, but that's also true of things that aren't entangled. I assure you if I went to Socrates, showed him a red ball and a blue ball, put them in a bag, and took out a ball at random that happened to be red, Socrates would have no problem realizing that the other ball must…

The analogy is fine for explaining entanglement. Sure it's more complicated when you consider superposition.

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

#204

Post by cma »

mrkstu wrote: post #137
cma wrote: post #35

Earlier quoted context omitted.

Correlations only but no useable communication. You can both make a decision on the same random info that isn't determined until later when you are apart, but can't know anything other than that if they followed the plan they made their choice based on the same later-determined random info, correlated with your random info. If they didn't follow the plan and measured orhogonal/same (can't remember which) spins, then…

If we agree before parting that one of us is going to Alpha Centari and the other is staying on Earth and going to assassinate either the President of Russia or America depending on the observed state on an entangled pair of particles, once I reach the star system. Doesn't the traveler have more information than anyone else on ship about whether an assassination attempt was made in Russia or America? and have it fast…

I think you would have a shared private piece of correlated information between each other that wasn't determined until you made the measurement (though maybe no joint reference frame to say who made it first), but you can't choose what it was (communicate with each other).

The universe either had to break the light barrier to make the measurements correlated (predetermining the outcome isn't generally possible because you could choose how to make the measurement based on another quantum measurement from something outside of the other participant's then-current light cone), or make the same choice through superdeterminism (the other measurement and all others were predetermined too and exact simulation of entire future universe's measurement decisions was shared between every particle when they were within some distance at big bang or something). But even though the universe broke the light barrier, you yourself aren't able to use it for communication.

In the many-worlds interpretation you've both branched into the same branch of the multiverse, but couldn't choose which branch. You do have private knowledge of which branch and the consequences of that, assuming you both followed the agreed on procedure.

I think you can use what you are describing in a series of correlated measurements to set up a provably secure one-time-pad, and then do secure classical communication with it. But you don't communicate the actual bits of the pad, you just both get correlated ones.

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

#205

Post by Retric »

normac2 wrote: post #197
0majors wrote: post #95

Earlier quoted context omitted.

That’s right. Not only it’s an analogy, it is also a bad one and completely misleading, at least according to physics of the last 50 years. Note how the article frets about the loss of locality.

Hmn. Is that at least what we experience if we try it as an experiment (even if the underlying physics is quite different than what it seems)?

The only thing we experience from preforming at an experiment is the data it provides. As such from the data from existing experiments is where all the spooky action at a distance is actually observed.

https://en.wikipedia.org/wiki/Bell_test though none of them are quite definitive on their own https://en.wikipedia.org/wiki/Loopholes_in_Bell_tests. I wouldn’t read much into the loopholes, but they do demonstrate just how difficult this stuff is.

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

#206

Post by joe_the_user »

danbruc wrote: post #191
joe_the_user wrote: post #152

Earlier quoted context omitted.

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 explana…

If you are only worried about analyzing a specific quantum system, then yes, for most part the interpretation does probably not matter. But I think in general the differences are very important, especially as we do not understand quantum mechanics and different interpretations will direct future research in different directions. If you believe in Copenhagen, you will try to figure out how to reconcile unitary evoluti…

If you believe in Copenhagen, you will try to figure out how to reconcile unitary evolution with wave function collapse.

This is saying the interpretations "exist". The interpretation like intermediate values in some calculation process that are never returned. If the interpretations are true, they can be seen, not just "locally".

It seems like a lot of this basically involves people who've "suspended disbelief" provisionally, accepted a violation of their intuition provisionally but still are hankering for their intuition to spring back into validity. It's like people who accept that general relativity specifies curved space, understand the implications but are still expecting to somehow find a higher dimensional space that all this is suspended in 'cause that's what a fundamental reality feels like to them.

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

#207

Post by lisper »

tylerhou wrote: post #181
lisper wrote: post #155

Earlier quoted context omitted.

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.

Would you claim that when Einstein developed his theories of relativity, they were invalid (from the point of view of physics) because their consequences were not yet observable? For example, Einstein used thought experiments to develop special relativity in 1905, but since kinematic time dilation was only experimentally confirmed in 1971, his work was not a contribution to physics until then?

The difference is that the limits on observing relativistic effects in 1905 were technological, whereas in QM you cannot observe the effects of entanglement in a non-isolated system even in principle. This is a fundamental constraint imposed by the theory itself. You can't get around it even with arbitrarily advanced technology.

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

#208

Post by feoren »

cepie wrote: post #174
feoren wrote: post #164

Earlier quoted context omitted.

Fine, you got me: the assertion that is obviously true , but goes further in that it invalidates the need for any of this discussion. If your goal was to engage me in a thought-measuring contest, sure, you win: you've spent more time thinking about this utterly ridiculous nonsense than I have. Congrats?

I bet you could make your points without insulting others. What do you think?

I think my tone was no different than naasking's.

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

#209

Post by joe_the_user »

suzzer99 wrote: post #168
naasking wrote: post #158

Earlier quoted context omitted.

> 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 co…

If the computer code running this simulation is that good to never have bugs, then the simulation is functionally identical to the meatspace real universe from our POV. So I don't know if there's any point thinking about it other than idle curiosity. But I do worry that for some simulation believers it could become an excuse to have less empathy towards fellow humans.

If "the simulation" and "reality" have the same properties, what would "being in the simulation" even mean? A thing/person/etc would "be" in both by definitions, be in neither by others, etc.

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

#210

Post by Kranar »

unparagoned wrote: post #203
Kranar wrote: post #150

Earlier quoted context omitted.

>Isn't it true that if you entangle two particles, separate them, then measure one it'll tell you something about the other particle? Yes that's true, but that's also true of things that aren't entangled. I assure you if I went to Socrates, showed him a red ball and a blue ball, put them in a bag, and took out a ball at random that happened to be red, Socrates would have no problem realizing that the other ball must…

The analogy is fine for explaining entanglement. Sure it's more complicated when you consider superposition.

Entanglement is only applicable when there is a superposition of conjugate pairs. Without it, there is literally no entanglement whatsoever.
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