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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?

#111

Post by eru »

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…

> [...] and the underlying mechanics and I kind of got the sense (with QC) that nobody really knows what they are talking about.

The math is fairly well known, and people can successfully apply it. As evidence in eg modern CPUs and GPUs and RAM actually working. And lots of other marvels of modern engineering that requiring an understanding of quantum mechanics to design and engineer.

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

#112

Post by staticassertion »

Nevermark wrote: post #79
staticassertion wrote: post #59

Earlier quoted context omitted.

It is not incomplete to say that something does not require explanation, nor is it saying it's "magic". It is a cost that your model might incur, that's it. https://arxiv.org/abs/2503.15776 In this paper a plurality of physicists stated that they felt that the initial conditions of the universe are brute facts that warrant no further explanation. This is not "our model doesn't yet account for it", it's "there is no e…

A model is incomplete if it doesn't explain something. That doesn't make a model wrong. All models we have are partial explanations. But that doesn't make it rational to claim that an incomplete model is complete. Or to treat unexplained specifics as inherently "just so", without cause or reason (i.e. magic), and we must just accept them as unexplainable instead of pursuing them with further inquiry.

> A model is incomplete if it doesn't explain something.

I've just explained that this is not strictly true. I don't know what else to say. Brute contingencies, by definition, do not require explanation. I then gave you a paper where scientists largely believe in brute contingencies.

I think if you want to know more you can look into this. Just look for topics about brute facts and brute contingencies.

If you want to deny that brute contingencies are possible, by all means. That's a totally valid view. Just understand that it's probably not the majority view among scientists and that you aren't necessarily "right" (just as those who hold to brute contingencies aren't necessarily "right").

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

#113

Post by eru »

superposeur wrote: post #47
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…

These debates over the interpretation of Quantum Mechanics (i.e. what ultimately happens when a “measurement” takes place) are important but don’t bear on the effectiveness of quantum computing. Regardless of your favorite interpretation (almost) everyone agrees that quantum computers should work and be able to do things classical computers cannot.

Well, to be slightly more sophisticated (to paraphrase Scott Aaronson):

Either quantum computers work (at least in principle), or our understanding of the universe is way off and we are getting exciting new physics.

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

#114

Post by eru »

cpncrunch wrote: post #92
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…

There is a somewhat easily digestible explanation of the quantum Darwinism theory here: https://arxiv.org/pdf/1811.09062 However, it still doesn't really address the core question of when the collapse actually occurs. All it really seems to add is that the environment is an "observer" and that decoherence actually causes the collapse.

Isn't 'collapse' just something that the Copenhagen Interpretation people made up?

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

#115

Post by qsera »

spot5010 wrote: post #53
Nevermark wrote: post #35

Earlier quoted context omitted.

> The part that I have trouble wrapping around with many worlds interpretation is how I as an observer end up in one of the many bifurcations. Pour water down a hill. Water clings to water, and we have hills that already have lots of correlations. We get streams that break up into multiple streams. How did one stream end up where it is? It seems like a good question, but it is circular. The stream is defined by where…

What you said here makes sense. Forgive me, but I have trouble even articulating what it is that I don’t understand correctly. Maybe what I meant was this: if I perform a quantum experiment where the spin measurement of an electron could be spin up or spin down, the future me would end up in one of two branches: I measure spin up, or I measure spin down. There wouldn’t be any possible world where I measure a superpos…

>But somehow “I” only experience only one of them.

Using the example from the other comment, "You" are the stream and not a drop of water in it.

In other words, you are not an entity with unique identity that traverse the tree of possibilities. You are part of the tree, actually, part of a branch. The branch's existence and your existence implies each other. Like your hand's existence and your existence imply each other. Your hand could not have existed without you (a similar looking one could. but it wouldn't be yours). And you without your hand (you could have had a different hand, but that wouldn't be "you" (which also includes the hand))

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

#117

Post by prmph »

superposeur wrote: post #40
prmph wrote: post #26

Earlier quoted context omitted.

I think the MWI is actually the just-so explanation you claim to avoid. Is it falsifiable? If you have a theory that seems unassailable by any logic, that's a good signal it is tautological and not very useful.

Yes, the MWI is falsifiable. It asserts that objective collapse does not occur, therefore any observation of objective collapse (such as predicted by GRW or Penrose-Diosi) would falsify it.

That's not true falsifiability; its asserting a negative.

I think people resort to MWI because they think it explains everything neatly; it does not!

For example, from my perspective, it does not explain what world I end up in, and if you are saying it's random, you need to come with a fundamental theory of randomness, unless the response is: it just exists, deal with it.

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

#118

Post by uh_uh »

Nevermark wrote: post #41
uh_uh wrote: post #14

Earlier quoted context omitted.

I'd say we are confused about both the lowest (quantum) and highest level (consciousness) phenomena of the known Universe. Quite humbling.

We have a theory whose plain reading matches experiment at all scales. Consciousness is something else. It is tempting for humans to pair mysteries up, pyramids and aliens, or whatever. But there isn't any factual basis for linking the experience of self-awareness with quantum mechanics. Is there a factual reason we know digital minds couldn't be conscious? Where quantum effects have been isolated from the operations…

I wasn't trying to link the two. Just pointed out that there seems to be a lot of unknowns on the map.

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

#119

Post by qsera »

goatlover wrote: post #107
A_D_E_P_T wrote: post #24

Earlier quoted context omitted.

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…

>You can't get experience out of abstract terms.

Would you agree that you are conscious at this point?

Would you agree that there are some set of physical laws, an initial state, and a set of random events to the universe that we inhabit?

Would you agree if we simulate this initial state on a computer, and step through it using the set of physical laws, and the random events, we will see the eventual emergence "you", who we know is conscious?

So are you saying that the entity inside the simulation is a zombie who is not actually conscious?

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

#120

Post by borissk »

spot5010 wrote: post #71
borissk wrote: post #10

Earlier quoted context omitted.

I think you're right, the many worlds interpretation makes the most sense. Unfortunately out current technology is very far from delivering any experimental confirmation or denial of any of the mainstream interpretations.

What if we create a situation in a lab that can be labelled as a collapse of the wave function by interaction with a macroscopic object. Except the macroscopic object is under our control and we can reverse the collapse. A quantum computer is such a macroscopic state.

From the decoherence / Many-Worlds view: No collapse occurred. Only entanglement happened.
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