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Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

quantamagazine.org

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Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#101

Post by itemize123 »

tbrownaw wrote: post #93
sampo wrote: post #81

Earlier quoted context omitted.

> Quantum physics is tricky because it frequently doesn't agree with our physical intuition. Quantum physics tricky for two separate reasons. (i) The mathematical theory (Schrödinger equation, wave function, operators, probabilities) is solid and well-defined, but may feel unintuitive, as you say. (ii) But quantum mechanics is also an incomplete theory. Even if you learn to be at peace with the unintuitive aspects of…

> is solid and well-defined, but may feel unintuitive I'm thinking that the nature of intuition is about training your neurons to approximate stuff without needing to detour through conscious calculation. And QM is in too high of a complexity class for this to be a thing.

it's not complexity but lack of training data right

Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#102

Post by anon291 »

Nevermark wrote: post #56
flockonus wrote: post #21

Earlier quoted context omitted.

Random is a very interesting concept. In relation to nature we seem to use "random" as anything we can't or are currently unable to model. To call something random doesn't mean it's impossible to model, in fact all sorts of natural facts seemed random one day before being covered by a model. One very relatable example example is the motion of stars in the the night sky, which seemed random for ages, until the Coperni…

I am not sure why you are being downvoted. The use of "random" as explanation or characterization in science has certainly spanned everything from "we don't know", to "there is inherent indivisible physical randomness". And I would agree, in the latter case it is a crutch. A postulate that something gets decided by no mechanisms whatsoever (randomness obeying a distribution still leaves the unexplained "choice"). It…

I'm not sure that's true. Randomness has a well-defined meaning for me: unable to be computed by a finite program. The vast majority of real numbers are thus composed of truly random digits. Suppose the universe has a constant that is a real number. The overwhelmingly vast majority of real numbers are non-computable and cannot be described by a finite descrition of any kind. Thus, if the universe were simply sampling numbers from this real constant (or simply the answer to the math is this real constant as it is undergoing some dynamics), then the numbers would appear random because the true underlying constant is non-computable, and thus appears random.

There is no possible finite way to describe if this were the case or not.

Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#103

Post by anon291 »

Veedrac wrote: post #82

Maybe I am just out of my depth, but I don't understand what problem quantum Darwinism is solving. The Schrödinger equation already explains why observers seem to agree: the ones that don't are separated from each other. This article is making some pilot-wave-like claim on top of quantum Darwinism that while the Schrödinger equation is real, all the 'real realness' exists in some pointer to a specific location inside…

I think the claim is this: the wave function never collapses. However, the effect of the wave function on the environment quickly converges to only one of the two states. We could not know the difference because we cannot directly observe the wave function. We only can see the result as it is magnified onto a macro scale by our observation equipment (or, lacking that, our eyes, which themselves turn a tiny microscopic phenomenon into macro signals). Once that particular outcome has been 'selected' for, the probability of the other outcome quickly becomes vanishingly small very fast. Thus, all future outcomes are that outcome, even though the underlying reality is still that fully entangled state.

Photons (and other objects that seem to behave 'quantumly') do not seem subject to this (and thus we can use them to understand quantum behavior) because they have particular properties wherein their behavior is not as affected by these macroscopic drop-offs quite as badly.

Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#104

Post by anon291 »

ur-whale wrote: post #68
suhputt wrote: post #64

Earlier quoted context omitted.

might make sense to link to the actual material you're referring to

> Highly recommend looking at Jacob Barandes’ formulation of quantum mechanics as non-Markovian stochastic processes. seconded >might make sense to link to the actual material you're referring to https://www.youtube.com/watch?v=sshJyD0aWXg In a fews sentences: the evolution of a physical system (quantum and classical) can very successfully be modeled as a stochastic process, and ... 1. state of the system is a real-v…

I'm not sure why you're okay with matrices but not the complex numbers. The complex numbers are a particular kind of matrix. Matrices and vector spaces (especially beyond the normal 3 dimensions) are even more mysterious. Complex numbers are fairly typical, and intuitive (rotations in space).

Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#105

Post by anon291 »

yoyohello13 wrote: post #39

Im fully willing to believe I just don’t “get it” but I took a pretty deep dive into quantum computing and the underlying mechanics and I kind of got the sense (with QC) that nobody really knows what they are talking about. I got this feeling so strongly that stopped studying the topic all together. I’m probably way off base and I’m probably missing some insights that I could get by going to school or something but t…

Funny, I looked into quantum computing and came away knowing pretty well how to use a future quantum computer. The math is pretty straightforward and useful. Now, getting an actual quantum computer with error correction that is scalable... that is still elusive.

Nevertheless, commercial quantum computers exist and do exactly what scientists predicted they would do.

Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#106

Post by goatlover »

A_D_E_P_T wrote: post #72
fnordlord wrote: post #62

Earlier quoted context omitted.

It's embarrassingly silly to say but I've frequently just boiled down the hard question to the question of "where is the experience of the color blue stored in the universe?" Even as a non-dualist, I still haven't found much of an answer that I like. I'm all ears if you've got a book recommendation.

The question presupposes that "the experience of the color blue" is a discrete object that needs a storage location. But that's the dualist picture in disguise. On a functionalist view, blueness isn't stored; it's what certain neural activity constitutively is when you're that system observing that blue. As an aside, isn't it more weird that violet and purple look indistinguishable despite being physically so differe…

> On a functionalist view, blueness isn't stored; it's what certain neural activity constitutively is when you're that system observing that blue.

Why should there be anything a certain neural activity is when making an observation? This is adding something additional to functionalism. You're just sneaking the hard problem back into the picture without realizing it.

Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#107

Post by goatlover »

A_D_E_P_T wrote: post #24
Sharlin wrote: post #23

Earlier quoted context omitted.

So you say that the hard problem of consciousness is explained by the fact that we appear to be conscious?

The kneejerk response would be: Are you not conscious at this present moment? If we were to modulate your spatiotemporal senses with drugs or a lobotomy, do you doubt that you would be very differently conscious, or perhaps entirely unconscious? I mean, there is a credible first-person answer to that question of yours, which each man can answer for himself. But considered more seriously, the "hard problem" is an arti…

> because experience is what such a system is, from the inside.

There being an inside to self-modelling systems bound in space and time is the hard problem.

> The question "why is there experience?" is exactly akin to "Why is there an interior to four walls and a roof?" The interior isn't a separate thing; it's necessarily constitutive.

That's given from three dimensions of space. This is not the case with subjective experience. Functional and physical terms don't have an inside where experience lives. It's what makes the p-zombie argument potent.

Let's put this another way. Functional terms are abstracted from experience to model the world. See Nagel's What It's Like to Be Bat paper on science being a view from nowhere, which is really about the fundamental objective/subjective split. Or Locke's primary and secondary qualities.

You can't get experience out of abstract terms. Experience doesn't live inside abstract concepts. We can model the world with them, but experience was left out at the start.

Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#108

Post by danbruc »

colechristensen wrote: post #46
yoyohello13 wrote: post #39

Im fully willing to believe I just don’t “get it” but I took a pretty deep dive into quantum computing and the underlying mechanics and I kind of got the sense (with QC) that nobody really knows what they are talking about. I got this feeling so strongly that stopped studying the topic all together. I’m probably way off base and I’m probably missing some insights that I could get by going to school or something but t…

>nobody really knows what they are talking about The mathematics of QM works extremely well. The interpretations of what the math is saying happens a varied and sometimes contradictory. We can predict what's going to happen extremely well, we just can't tell the story of what's happening. And there's been a century of trying to avoid the weirdness and failing. The problem might just be our brains evolved in a world t…

The mathematics of QM works extremely well.

Yes but also absolutely not. The evolution of the wavefunction when nobody is looking is unitary, which among other things means it is time-reversible. That math works extremely well and predicts the correct outcome.

When we are measuring a quantum system, the probability distribution of the measurement outcome is described by the Born rule, the amplitude of the wavefunction squared, and the collapse postulate tells us that after the measurement the wave function will be in the measured state, which is a non-unitary and non-time-reversible process. That math works extremely well and predicts the correct outcome.

But - really big but - what is a measurement device but a huge quantum system, what is a measurement but a quantum system and a measurement device and an environment undergoing time evolution? So both descriptions should apply, unitary time evolution and wave function collapse, but that can not be the case because they are incompatible, one is unitary, the other is not. The mathematical description is inconsistent.

Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#109

Post by qsera »

fnordlord wrote: post #62
A_D_E_P_T wrote: post #20

Earlier quoted context omitted.

It's not hard at all when you acknowledge that such senses exist in the world, and that you (like others) possess them. As an aside it tends to foster a certain tendency towards empathy. In essence, you're asking why there's an inside to being a self-modeling system. But "inside" isn't something extraneous, something additional -- rather, it's what "self-modeling" means. Really the "hard problem" has a very easy answ…

It's embarrassingly silly to say but I've frequently just boiled down the hard question to the question of "where is the experience of the color blue stored in the universe?" Even as a non-dualist, I still haven't found much of an answer that I like. I'm all ears if you've got a book recommendation.

>where is the experience of the color blue stored in the universe?

It is not stored anywhere. It is part of the consciousness that experience it. In other words consciousness comes bundled with everything it will ever feel.

Re: Are the Mysteries of Quantum Mechanics Beginning to Dissolve?

#110

Post by qsera »

Nevermark wrote: post #56
flockonus wrote: post #21

Earlier quoted context omitted.

Random is a very interesting concept. In relation to nature we seem to use "random" as anything we can't or are currently unable to model. To call something random doesn't mean it's impossible to model, in fact all sorts of natural facts seemed random one day before being covered by a model. One very relatable example example is the motion of stars in the the night sky, which seemed random for ages, until the Coperni…

I am not sure why you are being downvoted. The use of "random" as explanation or characterization in science has certainly spanned everything from "we don't know", to "there is inherent indivisible physical randomness". And I would agree, in the latter case it is a crutch. A postulate that something gets decided by no mechanisms whatsoever (randomness obeying a distribution still leaves the unexplained "choice"). It…

Random events are those events who's occurrences will not prevent consciousness that observes it from existing.

No one is deciding anything.

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