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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

#121

Post by tourist2d »

Zenbit_UX wrote: post #61

Whenever I hear about weird shit from the realm of quantum physics (this theory, double-slit, etc..) I can't help but think: Why would I hardcode values for imperceptible objects, that would take an enormous about of ram and cpu time to constantly update values in the off chance it's needed. Much more efficient to optimize for what the _player_ can see at their perspective. Oh and I should probably code in some error…

It could also be that our universe takes up so little resources on "gods" computer ;)

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

#122

Post by Ataraxy »

Zenbit_UX wrote: post #61

Whenever I hear about weird shit from the realm of quantum physics (this theory, double-slit, etc..) I can't help but think: Why would I hardcode values for imperceptible objects, that would take an enormous about of ram and cpu time to constantly update values in the off chance it's needed. Much more efficient to optimize for what the _player_ can see at their perspective. Oh and I should probably code in some error…

If you had infinite memory and energy such optimizations wouldn't be needed to begin with.

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

#123

Post by felipeko »

unishark wrote: post #114
keymone wrote: post #111

Earlier quoted context omitted.

Sure, just like a thermostat doesn’t experience the feeling of temperature, there is no need for human to feel it, so I understand that we need to explain why is it that we still feel the feeling rather than just observe the signal and react. So why is it wrong to explain this by the necessary recursiveness of predictive modeling that includes modeling “self”? We observe the temperature but we also observe ourselves…

Yes but where does this observer come from in the first place? Some theories do presume the thermostat experiences the temperature, just in a less-sophisticated form of consciousness. If an "observer" is nothing more than neurons firing in response to stimuli, then it's not fundamentally different from the thermostat.

Exactly.

It is understandable that having an model of an observer can be useful to a brain.

But how/why does that opens a window to an actual observer, and not just a model, is the question.

And we only know that - an actual observer exists - through first hand experience. It is our most immediate and certain knowledge (Cogito, ergo sum), everything else can be questioned. Yet, there's nothing in physics or computer science that gives a hint to this being the case.

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

#124

Post by lisper »

narag wrote: post #119
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…

So in your opinion, does this thought experiment can be translated to a "real" experiment now or in a not-so-distant future, like in our lifetimes?

That depends on what you mean. If you mean using a simple system (like a single photon) as a stand-in for Wigner's friend, that has already been done. That's what the OP was about. If you mean using a complex entity like an actual human or an AI that can pass a Turing test, I'll give long odds against.

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

#125

Post by jlokier »

Zenbit_UX wrote: post #61

Whenever I hear about weird shit from the realm of quantum physics (this theory, double-slit, etc..) I can't help but think: Why would I hardcode values for imperceptible objects, that would take an enormous about of ram and cpu time to constantly update values in the off chance it's needed. Much more efficient to optimize for what the _player_ can see at their perspective. Oh and I should probably code in some error…

That model of efficiency (RAM and CPU time) is based on classical computation.

When your underlying model of computation is full quantum computation, it's simpler to just run everything at once. It takes no energy if you run everything without picking out a scenario (but in a kind of "tree falling in a forest" way), and more energy if you select out specific scenarios to look what happened (I/O is expensive). Counter-intuitively, the computation part of quantum systems is free in ways that we consider classical computers expensive to run. It's reversible and doesn't consume any energy.

That may seem like it's avoiding the point, after all what does it take to run the "underlying model of computation".

But what I'm trying to say is that "quantum all the way down" (see also turtles) is as much a valid model as "mechanical computation all the way down", which your picture relies on. Neither of them is more fundamental.

It may seem like quantum-all-the-way-down is a bit artificial, because we can in principle run quantum simulations on classical computers, which seem simpler. But it turns out we can't. There is a fundamental intractability barrier for simulations above an arbitrary tiny size, which means we can only simulate interesting quantum systems using other quantum systems. It really is quantum-all-the-way-down.

If god came up with the quantum-all-the-way-down version, I'd say that's pretty clever, because it's way more efficient than anything you would implement, with your old-school classical RAM and classical CPU.

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

#126

Post by incognition »

Thorentis wrote: post #120
bondarchuk wrote: post #6

The original Wigner's friend paradox: https://en.wikipedia.org/wiki/Wigner%27s_friend The paradox seems to rest on magical thinking about consciousness, and if one simply accepts that a conscious observer can be in a superposition like any other piece of matter, the paradox is resolved. And, from the article: For Wigner, this was an absurd conclusion. Instead, he believed that once the consciousness of an observer be…

From the Wikipedia: > "From the point of view of the friend, the measurement result was determined long before Wigner had asked about it, and the state of the physical system has already collapsed. When now exactly did the collapse occur? Was it when the friend had finished their measurement, or when the information of its result entered Wigner's consciousness?" This to me, shows just how hand-wavy the whole superpos…

QM is not hand wavy and gives precise results for many practical problems. Your theory is wrong as per one of the simplest quantum experiment - the single electron double slit problem.

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

#127

Post by jlokier »

felipeko wrote: post #123
unishark wrote: post #114

Earlier quoted context omitted.

Yes but where does this observer come from in the first place? Some theories do presume the thermostat experiences the temperature, just in a less-sophisticated form of consciousness. If an "observer" is nothing more than neurons firing in response to stimuli, then it's not fundamentally different from the thermostat.

Exactly. It is understandable that having an model of an observer can be useful to a brain. But how/why does that opens a window to an actual observer, and not just a model, is the question. And we only know that - an actual observer exists - through first hand experience. It is our most immediate and certain knowledge (Cogito, ergo sum), everything else can be questioned. Yet, there's nothing in physics or computer…

Ok, so first hand experience tells you an observer exists.

Are you sure that observer has your personality, mind and memories? Are you sure that observer is involved in any way with the world, other than observing it?

Or are those other things just part of the machinery, and quite illusory. For example our perception of time, coherent thought and personality aren't all that consistent, as we know from various experiments and observations.

Here is the crux of my point:

If there's an actual observer, let's call it "primal consciousness", but they are observing the world through the lens of a mind, which is a complex, self-referential, reactive process running on a brain and body, we don't need to say that any particular physical process "creates" consciousness. We can settle with physical processes create something complex and interesting, which runs models of itself and the world, which "primal consciousness" observes. The "mind machine" running on the physics does not contain the observer, it's observed by the observer.

That doesn't "solve" the hard problem, but it's a model with different properties and consequences than some of the other models.

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

#128

Post by criddell »

Ma8ee wrote: post #104
criddell wrote: post #93

Earlier quoted context omitted.

Both paths you laid out are built upon the idea that superposition happens. Is there any serious consideration these days that superposition itself is dead end?

There’s kind of a massive amount of experimental evidence that superpositions happen.

I didn't know that. If you have more information I'd love to learn about it. I was under the impression that collapse wiped out all information about any other states.

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

#129

Post by Thorentis »

incognition wrote: post #126
Thorentis wrote: post #120

Earlier quoted context omitted.

From the Wikipedia: > "From the point of view of the friend, the measurement result was determined long before Wigner had asked about it, and the state of the physical system has already collapsed. When now exactly did the collapse occur? Was it when the friend had finished their measurement, or when the information of its result entered Wigner's consciousness?" This to me, shows just how hand-wavy the whole superpos…

QM is not hand wavy and gives precise results for many practical problems. Your theory is wrong as per one of the simplest quantum experiment - the single electron double slit problem.

The variation of the double split experiment that supposedly proves that observance "changes" the outcome, is only a thought experiment, and therefore can be flawed due to incorrect thinking. Obviously, the basic double slit experiment which shows the wave/particle duality of light is done in practice and therefore empirical.

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

#130

Post by jlokier »

keymone wrote: post #111
felipeko wrote: post #105

Earlier quoted context omitted.

By inner experience, we mean that there's a subject which gets to have perception of such models. There's no need for such subject to exist. For example, most people assume that, so far, computers do not have any inner experience. A computer could, conceivably, execute the same functions as our brain, yet have no inner experience of anything. Numbers get in, numbers get out, without any inner experience being needed.

Sure, just like a thermostat doesn’t experience the feeling of temperature, there is no need for human to feel it, so I understand that we need to explain why is it that we still feel the feeling rather than just observe the signal and react. So why is it wrong to explain this by the necessary recursiveness of predictive modeling that includes modeling “self”? We observe the temperature but we also observe ourselves…

It's only wrong because it's not really an explanation. At best, it's a weak one.

Saying that an active model of self "is" what we experience as the consciousness we experience doesn't tell us why we have that experience.

We can just as easily imagine a complex machine with an active self-model that isn't conscious, as one that is.[1] So an active self-model doesn't tell us about consciousness. This shows them to be different concepts, not different names for the same concept. Which means neither "is" the other, and "is" is not an explanation.

[1] (To be a little more picky, we can't imagine that if we insist they are the same thing, but that leads to circular reasoning here. Our questioner can imagine both, and for an explanation to explain it needs to address the question, not wave it away by offering something circular.)

It all sort of falls apart when we only talk about whether an object other than ourselves is conscious or not.

As far as we know[2], we can't distinguish consciousness of other objects by observation. A hypothetical non-conscious machine might tell us it is conscious; we will never know if it's GPT-3000 talking or if it's another being like ourselves. So eventually we'll probably decide that it's moot, and treat it as conscious if it behaves convincingly and consistently like it is.

[2] That could change, it's not ruled out.

But that doesn't deal with the "hard problem" of consciousness, which is ourselves.

For ourselves, we are in no doubt about the direct experience of our own consciousness. We might convince ourselves that it's just an active self-model, processing, because of how we think of data processing machines these days. But we shouldn't, for one because that's a weak explanation that doesn't explain, and for two because there are other active self-models in the universe, and also in the much larger abstract realm of "unexecuted" self-models that could exist (pick an RNG seed and set of rules of your choice). We don't experience those, so the one(s) we do experience are notably distinct, for no obvious reason.

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