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Physicists found a new quantum paradox that casts doubt on a pillar of reality

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Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#31

Post by mylons »

ahelwer wrote: post #24
canjobear wrote: post #20

Earlier quoted context omitted.

> if one simply accepts that a conscious observer can be in a superposition like any other piece of matter, the paradox is resolved. It’s not so simple. Suppose you’re in a box and observe a quantum experiment, and then I open the box and observe you. Then before I open the box you’re in a superposed state |x> + |y>, corresponding to the two possible outcomes x and y. Fine, no problem so far. But what is your own sub…

Many-worlds interpretation takes care of this. Anyway, how do you know your experience of the world cannot be superposed? Have you ever been in superposition? We make up stories to maintain consistent histories all the time.

did you just yada-yada Many-worlds?

Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#32

Post by Zenst »

lisper wrote: post #30

> if the "friend" is a human-level artificial intelligence running in a massive quantum computer. Well, there's your problem right there. No AI can run on a quantum computer. Intelligence is inherently a classical phenomenon because it requires copying information, and quantum states cannot be copied, only classical states can be copied. The classical world "emerges" from the quantum world when you take a quantum sys…

> quantum states cannot be copied

Wouldn't quantum entanglement enable a comparable ability?

Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#33

Post by henearkr »

The part that seems the most dubious to me is the "choice":

> 2. It is possible to make free choices, or at least, statistically random choices.

I don't see what would be really compelling in that.

If it's false it would just mean that our actions are all kind of mechanistically decided by other events, and that does not shock me.

Other point:

> 1. When someone observes an event happening, it really happened.

What if it really happened in the reality of the observer (and maybe not in other realities)? What is meant by "reality"? Some insight is to be gained by precising what we call the reality, in relation to the corpus of all the observations in what we believe is our universe.

Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#34

Post by amelius »

lisper wrote: post #30

> if the "friend" is a human-level artificial intelligence running in a massive quantum computer. Well, there's your problem right there. No AI can run on a quantum computer. Intelligence is inherently a classical phenomenon because it requires copying information, and quantum states cannot be copied, only classical states can be copied. The classical world "emerges" from the quantum world when you take a quantum sys…

> Intelligence is inherently a classical phenomenon because it requires copying information, and quantum states cannot be copied, only classical states can be copied.

Ok, so make classical pointers to quantum states and copy the pointers instead of the quantum states :)

Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#35

Post by 08-15 »

> Take a look at these three statements [...] they cannot all be true

Okay, so we have to kill one. The easiest one to kill is

> It is possible to make free choices.

In other words, quantum mechanics is incompatible with free will. This is clearly shocking to any physicist who believes in Free Will (as defined by philosophers thousands of years ago). But hasn't Free Will been recognized as nonsense for at least two centuries by now?

Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#36

Post by guerrilla »

bondarchuk wrote: post #9
TheOtherHobbes wrote: post #7

Earlier quoted context omitted.

You might consider reading the original paper. Because the experiment doesn't rely on conscious observers at all. (Unless you think photons are conscious, which I'm assuming you don't.)

Well, that's the point. The experiment shows that one of three assumptions has to be false. But one of these (AOE) being false is not surprising or concerning at all, when dealing with non-conscious observers (such as photons, indeed). With conscious observers it would be concerning to some (not to me, but to Wigner and presumably the authors), because of the supposition that there's something special about conscious…

> Absoluteness of Observed Events is false when the observers are photons, which (my layman's assumption) should surprise exactly nobody

I'm with you but is this experimental result not new though? It seems like they're on our side and confirming what should be a non-surprising result, which is good work.

Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#37

Post by adrianN »

lisper wrote: post #30

> if the "friend" is a human-level artificial intelligence running in a massive quantum computer. Well, there's your problem right there. No AI can run on a quantum computer. Intelligence is inherently a classical phenomenon because it requires copying information, and quantum states cannot be copied, only classical states can be copied. The classical world "emerges" from the quantum world when you take a quantum sys…

I'm not convinced that intelligence requires copying information in the way that the no-cloning theorem forbids. Approximate cloning is not forbidden for example.

Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#38

Post by coliveira »

henearkr wrote: post #33

The part that seems the most dubious to me is the "choice": > 2. It is possible to make free choices, or at least, statistically random choices. I don't see what would be really compelling in that. If it's false it would just mean that our actions are all kind of mechanistically decided by other events, and that does not shock me. Other point: > 1. When someone observes an event happening, it really happened. What if…

The main problem of quantum interpretation is the supposed, artificial, distinction between observer and observed system. In a quantum world this distinction is not possible, every event capable of "observing" a system is itself part of the system, modifying it. That's why such interpretations (postulating this separation) give all kinds of strange paradoxes that are impossible to solve. In the quantum world, there is no such thing as an observer, it is just all part of the system.

Consider for example the system composed of a pool table. In classical physics we can assume we can always measure the position and momentum of all balls in the table. But what would happen if measurement was not possible without big changes in position and velocity? Suddenly the whole notion of "observation" would lose its meaning, and the only way to describe the pool table is as a probabilistic mesh of balls moving around in uncertain directions.

Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#39

Post by guerrilla »

jonahbenton wrote: post #13
thechao wrote: post #12

Earlier quoted context omitted.

I’m just now teaching myself QM (20 years after school). I can tell you that in QM, seemingly innocuous phrases like “locality” have highly unintuitive, nonstandard meanings. I’m just now getting a glimpse at how amazingly fucking awful pop-sci QM articles are. If you’re interested in QM, read “The Theoretical Minimum”; the second book gets into QM. There are video lectures of the same material that complement the se…

Appreciate the reference, cheers.

There are lectures by Susskind at Stanford on YouTube that go with them by the way.

Re: Physicists found a new quantum paradox that casts doubt on a pillar of reality

#40

Post by boomboomsubban »

Zenst wrote: post #32
lisper wrote: post #30

> if the "friend" is a human-level artificial intelligence running in a massive quantum computer. Well, there's your problem right there. No AI can run on a quantum computer. Intelligence is inherently a classical phenomenon because it requires copying information, and quantum states cannot be copied, only classical states can be copied. The classical world "emerges" from the quantum world when you take a quantum sys…

> quantum states cannot be copied Wouldn't quantum entanglement enable a comparable ability?

I may be wrong, but I'm fairly sure you need to entangle the particles before they become a quantum state.
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