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The Zen anti-interpretation of quantum mechanics (2021)

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Re: The Zen anti-interpretation of quantum mechanics (2021)

#71

Post by DiogenesKynikos »

goatlover wrote: post #53
DiogenesKynikos wrote: post #37

Earlier quoted context omitted.

The Many-Worlds Interpretation is not really an interpretation. It just says that the known laws of Quantum Mechanics are correct, and that any measurement process itself has to obey the laws of Quantum Mechanics. In other words, nothing un-Quantum-Mechanical happens during measurement.

It’s an interpretation because we don’t have any empirical evidence for the other worlds. Science requires evidence, math alone isn’t enough. MWI is metaphysics, which is fine. We all wax philosophical sometimes as humans. Even the great Feynman couldn’t help himself.

There is a massive amount of evidence that Quantum Mechanics is the way the Universe works, and the MWI is simply vanilla Quantum Mechanics, with zero further assumptions.

The problem is that the name "Many Worlds Interpretation" sounds grandiose. "Many worlds" is simply an imaginative way of describing the existence of different states of the wavefunction - a concept that is extremely well established and universally accepted. MWI just says that we should assume that Quantum Mechanics holds in all situations, including when we make measurements (i.e., there's nothing special about the measurement process).

Re: The Zen anti-interpretation of quantum mechanics (2021)

#72

Post by kgwgk »

graycat wrote: post #58

Sure, I'd like to read Aaronson and tried. My difficulty with quantum mechanics is much earlier, that is, more elementary and basic than what Aaronson considers. I've watched MIT lectures, looked into books by experts, ..., and I get nothing I can believe in. Right in the first hour, I get questions with no answers. E.g., (1) Wave Function. Okay. I can't find a definition of a wave function. Nothing subtle but just t…

> Simpler, for an electron, where in the wave function is the spin of the electron?

https://en.wikipedia.org/wiki/Dirac_equation

“There are four components in ψ because the evaluation of it at any given point in configuration space is a bispinor. It is interpreted as a superposition of a spin-up electron, a spin-down electron, a spin-up positron, and a spin-down positron.”

Re: The Zen anti-interpretation of quantum mechanics (2021)

#73

Post by dilap »

blamestross wrote: post #62
blamestross wrote: post #59

Earlier quoted context omitted.

But it's not you. And the idea of every possiblity playing out is a lot less exciting than idealized. The Alter where you both exist and is better is not actually guaranteed to exist. In fact basically all them are guaranteed to essentially identical. Quantum splits at a macro level would basically only happen now that we have quantum random number generators to make decisions based on and I doubt that will add up to…

You are welcome to whatever religion you need to settle your existential emotional needs, but don't expect the science to play out in a direction that matches your fantasy.

Well, sure, you could equally find it to be anti-comforting. I just think (1) there is a truth to reality, beyond even what we might be able to physically access and (2) it's interesting to ponder what that might be. Maybe even comforting, depending on your mindset.

Re: The Zen anti-interpretation of quantum mechanics (2021)

#74

Post by LightMachine »

criddell wrote: post #35
LightMachine wrote: post #9

Earlier quoted context omitted.

And it is absurd to say it has no direct practical implications. We still don't know all of physics, and part of the reason is precisely because we're stuck in the wrong mindset regarding how nature works. Only a better insight on the true nature of the universe can give us the correct mathematical models.

> the correct mathematical models There are those that think reality (including the universe) is just mathematics. Not modeled by mathematics, but is mathematics. To me, the mathematical universe hypothesis is starting to be the only theory that makes sense.

Wait isn't that the common assumption? That the universe is just an algorithm and we're trying to figure which is it?

Re: The Zen anti-interpretation of quantum mechanics (2021)

#75

Post by LightMachine »

thinkmcfly wrote: post #11
LightMachine wrote: post #9

Earlier quoted context omitted.

And it is absurd to say it has no direct practical implications. We still don't know all of physics, and part of the reason is precisely because we're stuck in the wrong mindset regarding how nature works. Only a better insight on the true nature of the universe can give us the correct mathematical models.

Can you explain what the direct and practical implications are? I don't know if I buy what the link says about this, but I do know that no one has ever found utility by being frustrated about many worlds

I mean that interpretations have practical implications because they're the only way to find the true laws of physics, which in turn has obviously applications. For example, if you believe in superdeterminism, and you obviously should, then that will save a lot of work researching dead ends (like multiverse stuff), which will make us find the correct algorithms faster.

Re: The Zen anti-interpretation of quantum mechanics (2021)

#76

Post by LightMachine »

mathgenius wrote: post #45

I like the many-interpretations interpretation of quantum. It says that you should believe all of them, or rather, choose a different interpretation based on your mood. For the optimistic, it's many-worlds. If you are going out tonight & hoping to get lucky, it better be Copenhagen. If you are falling into despair then it's going to be superdeterminism for you.

> If you are falling into despair then it's going to be superdeterminism for you.

If you don't believe in fairy tales nor assume the existence of a magic mysterious force named "free will" *

Re: The Zen anti-interpretation of quantum mechanics (2021)

#77

Post by gaze »

graycat wrote: post #58

Sure, I'd like to read Aaronson and tried. My difficulty with quantum mechanics is much earlier, that is, more elementary and basic than what Aaronson considers. I've watched MIT lectures, looked into books by experts, ..., and I get nothing I can believe in. Right in the first hour, I get questions with no answers. E.g., (1) Wave Function. Okay. I can't find a definition of a wave function. Nothing subtle but just t…

Ok this is a lot so I can't tackle all of it but let's see

(1) The wave functions are vectors in a Hilbert space. Functions can form a vector space. The domain of these functions you might as well think of a bit like an index, but continuous. If I have a 2 component vector that's used to represent spin, it can be indexed like psi_0, psi_1. I have psi, you give me 0 or 1, you get a complex number corresponding to the probability amplitude. If I have an infinite-component vector I'm using to represent the position of a particle, you can index it with psi(x=something). I have a psi, you give me a something, I give you a complex number.

(2) Any time you have a question about QM, ask the CM question first. Where is the color of the bouncing ball I'm modeling incorporated? Well, it's not being modeled, so we needn't incorporate it. Ultimately if you have multiple properties you want to represent, you can take the tensor product of the hilbert spaces that model those properties. I have a hilbert space for the position space, and I have a hilbert space for the spin. You just stick them together with the tensor product.

(3) That's the theory and it works in the lab. I don't have a much better answer for you here.

(5) The point of superposition is that h indeed is a valid state of the system, to say nothing of how you'd actually construct it. I don't know how to say what you want "in general." All you've done is make _some_ new state.

(6) I can't figure out what this means -- I think it's not even wrong. You can never know the wavefunction of a system without having several copies available or having some strong constraints on it.

(7) When you detect at f you've collapsed the path of the electron to the path along which you've detected it traveled. If you know you've sent the electron and you get no click on g, then you know it's on path f.

(8) The wavefunction is basically in your head (according to my religion.) It doesn't really "propagate" so much as help you predict what will happen. If you like -- yes, causality propagates at the speed of light. Really we should say light propagates at the speed of causality, and the wavefunction behaves the same. In the end, once all participants are brought together to compare answers, both QM and relativity ensure their answers are consistent.

Re: The Zen anti-interpretation of quantum mechanics (2021)

#78

Post by andreareina »

LightMachine wrote: post #76
mathgenius wrote: post #45

I like the many-interpretations interpretation of quantum. It says that you should believe all of them, or rather, choose a different interpretation based on your mood. For the optimistic, it's many-worlds. If you are going out tonight & hoping to get lucky, it better be Copenhagen. If you are falling into despair then it's going to be superdeterminism for you.

> If you are falling into despair then it's going to be superdeterminism for you. If you don't believe in fairy tales nor assume the existence of a magic mysterious force named "free will" *

Superdeterminism is hardly the only one to pose problems for some definitions of free will. It's also not a problem for others, i.e. https://en.wikipedia.org/wiki/Compatibilism

Re: The Zen anti-interpretation of quantum mechanics (2021)

#79

Post by _0w8t »

pdonis wrote: post #63
_0w8t wrote: post #15

The article misses that we do not know how classical world that we perceive arises. Ultimately according to QM the whole universe is just single wave function with no probabilities. But this contradicts our experience of the classical world including that we measure probabilities. So we need to explain that to avoid various very ad-hock notions of classical measurement device and similar routes. There are attempts to…

> There are attempts to explain the classical world using a notion of decoherence, but that have problems with little progress in the last, say, 20 years to address them. What problems? Note that Aaronson, in the article (as well as a number of commenters in the comments) gives decoherence as precisely the answer to the issue you raise.

One problem is the preferred basis. Why decoherence selects a particular basis?

Another is that decoherence still does not explain the origin of probabilities. I.e. there are models that shows how a pure classical system may arise. But we still have no explanation how a classical device interacting with a quantum system gets the value it measures.

Re: The Zen anti-interpretation of quantum mechanics (2021)

#80

Post by wruza »

kahnclusions wrote: post #61
goatlover wrote: post #31

Earlier quoted context omitted.

So you’re endorsing Many Worlds with an appeal to the anthropic principle. That’s fine, but you do have to assume MWI is the true interpretation of the mathematical formalism.

I’m not a fan of Many Worlds. Communication or even detection of the split universes is impossible, which means it is impossible to measure. And science requires measurement to confirm our theories. Which means the MWI is equivalent to a simpler interpretation that doesn’t require split universes.

MWI is equivalent to a simpler interpretation that doesn’t require split universes

Under aforementioned requirement, of course. If some sort of MWI is true, there may be just no way to confirm it, and that’s it.

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