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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)

#91

Post by _0w8t »

pdonis wrote: post #64
_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…

> the new take is that the classical notion that the state of a system can be fully described by its properties at some moment in time is wrong. One also needs to know some information about future to fully describe evolution of the system. Do you have any references that give more details on this?

See https://en.m.wikipedia.org/wiki/Lawrence_Schulman and the book Time’s Arrow and Archimedes’ Point by Huw Price

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

#92

Post by goatlover »

DiogenesKynikos wrote: post #71
goatlover wrote: post #53

Earlier quoted context omitted.

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 universall…

QM isn’t a complete description of the universe because of gravity, dark energy, dark matter, the arrow of time, and it doesn’t explain probability. So it’s a little premature to say that’s how the universe works.

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

#93

Post by dools »

consilient wrote: post #82
dools wrote: post #68

Earlier quoted context omitted.

> what in your personal aesthetic tastes is making atoms more palatable? It’s pretty easy for me to imagine things bumping into each other because I see that happening all around me

Atoms aren't anything like that though. There are no little billiard balls, probability densities don't "bump", electrons don't actually orbit, and so on. Atoms just are what they are, and what they are does not admit a good "macrophysical analogy".

Well for some definition of the word “bump”.

What I mean is that the mechanism by which sound travels is the same as the mechanism by which I can punch a punching bag and see it swing.

Even if the two materials never “come into contact” because it’s actually the result of charges repelling each other or whatever, the way it works in both cases is the same.

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

#94

Post by consilient »

TedDoesntTalk wrote: post #86
consilient wrote: post #82

Earlier quoted context omitted.

Atoms aren't anything like that though. There are no little billiard balls, probability densities don't "bump", electrons don't actually orbit, and so on. Atoms just are what they are, and what they are does not admit a good "macrophysical analogy".

> There are no little billiard balls … electrons don't actually orbit Wait, what? What do they do then? My physical science education ended in high school.

The next useful falsehood on the ladder is that electrons in an atom exist as probability densities around the nucleus. Fire a photon here, and knock an electron off with this probability; fire it there, and get that probability instead. But before they interact with something, electrons aren't anywhere in particular. https://en.wikipedia.org/wiki/Atomic_orbital

The real answer is that constituent parts of bound states like atoms don't really exist as separate things. An atom is a particular very complicated field configuration, and if you want anything deeper than that you're going to have to learn QFT.

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

#95

Post by consilient »

dools wrote: post #93
consilient wrote: post #82

Earlier quoted context omitted.

Atoms aren't anything like that though. There are no little billiard balls, probability densities don't "bump", electrons don't actually orbit, and so on. Atoms just are what they are, and what they are does not admit a good "macrophysical analogy".

Well for some definition of the word “bump”. What I mean is that the mechanism by which sound travels is the same as the mechanism by which I can punch a punching bag and see it swing. Even if the two materials never “come into contact” because it’s actually the result of charges repelling each other or whatever, the way it works in both cases is the same.

Sure, but at that level of generality you're also talking about the mechanism by which light propagates.

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

#96

Post by andrewflnr »

scottmsul wrote: post #43

Something that's always bothered me about many-worlds is that it states the number of worlds should always be increasing exponentially. Which means from an anthropic point of view, the most likely time to be born is the last ever human, with insanely exponential odds. But many people have been born in my lifetime, ergo many-worlds seems unlikely.

This kind of thing is exactly why you shouldn't take those sorts of anthropic argument too seriously.

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

#97

Post by Eupraxias »

dools wrote: post #68
krastanov wrote: post #20

Earlier quoted context omitted.

For many people the statement "electromagnetic fields exist as a (fundamental) building block of Nature" is just as reasonable as "atoms exist as a (fundamental) building block of Nature". The word "fundamental" is not particularly important, I am keeping it for historical reasons. You are perfectly comfortable with the existence of atoms (given your comments about understanding sound waves), presumably because you k…

> what in your personal aesthetic tastes is making atoms more palatable? It’s pretty easy for me to imagine things bumping into each other because I see that happening all around me

All of this makes more sense when understood in terms of Field theory: David Tong: Quantum Fields https://youtu.be/zNVQfWC_evg?t=1168

"All the electrons that are in your body are not fundamental. All the electrons that exist in your body are waves of the same underlying field."

The next question is, if there are no individual things, what does math count? http://www.katabane.com/mt/ontology.html

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

#98

Post by _0w8t »

DiogenesKynikos wrote: post #69
Jensson wrote: post #49

Earlier quoted context omitted.

So when does decoherence happen? Provide a formula for it. That is what people struggle with in quantum mechanics, MWI just deflects the question. Without a formula for when this phenomena happens any "interpretation" is just nonsense, except as a tool to get towards that formula.

The mathematical framework for modeling decoherence involves coupling an isolated system to a thermal bath, described by a density matrix. Decoherence is a phenomenon that's been studied mathematically and experimentally, not simply an interpretation or hand-waving.

This notion does not explain how the thermal bath appears. I.e. why the system interacts with a particular bath and not a superposition of such baths?

At best the decoherence can try to explain how appearance of a sufficiently big classical object may trigger appearance of other objects, but it does not explain how the initial object appears.

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

#99

Post by klysm »

howling wrote: post #33

In some sense, classical probability is just the study of category of Markov Kernels [0]. We can gain much of the insight without a lot of measure theory/functional analysis machineries by restricting to its full subcategory of finite states, which gets us to the category of stochastic matrix. In this view, quantum probability (of finite states) is just about study of category of classical quantum maps described in P…

Idk anything about measure theory, but I do know some things about markov chains so I was excited about [0]. Unfortunately measure theory is invoked directly in the definition so I’ll have to go down that wiki rabbit hole

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

#100

Post by consilient »

gaze wrote: post #70
_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…

> just single wave function with no probabilities this is definitely not true and contradicts relativity. (Type-III Von Neumann algebras have no pure states.)

> Type-III Von Neumann algebras have no pure states

All this means is that you're not going to recover the state of the entire universe from local observables. Disappointing, but hardly surprising.

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