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On the Double-Slit Experiment and Quantum Interference in the Wolfram Model (2020)

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Re: On the Double-Slit Experiment and Quantum Interference in the Wolfram Model (2020)

#31

Post by nabla9 »

prof-dr-ir wrote: post #27
lisper wrote: post #18

Earlier quoted context omitted.

Scott Aaronson has an insightful essay on this in chapter 9 of his excellent book, "Quantum Computing Since Democritus". The TL;DR is that quantum mechanics can be derived as a generalization of probability theory using the 2-norm instead of the 1-norm. In Aaronson's words: "Quantum mechanics is what you would inevitably come up with if you started with probability theory, and then said, let's try to generalize it so…

To counter your enthusiasm I must say that I rather disliked his reasoning. My problem is essentially that what Aaronson's calls "the theory" is a somewhat bastardized version of quantum mechanics that might suffice for quantum computing but, in my opinion, not for physics. I discussed the difference earlier: https://news.ycombinator.com/item?id=38255476

To counter your unenthusiasm, think about it from a mathematician's perspective. Mathematics of QM does not live in some separate corner created to do physics. The need for QM created short-lived confusion, now it's all embedded into a much larger coherent mathematical structure.

For a pure mathematician, quantum mechanics is a lovely introduction to Hilbert Spaces.

Re: On the Double-Slit Experiment and Quantum Interference in the Wolfram Model (2020)

#32

Post by eigenket »

prof-dr-ir wrote: post #27
lisper wrote: post #18

Earlier quoted context omitted.

Scott Aaronson has an insightful essay on this in chapter 9 of his excellent book, "Quantum Computing Since Democritus". The TL;DR is that quantum mechanics can be derived as a generalization of probability theory using the 2-norm instead of the 1-norm. In Aaronson's words: "Quantum mechanics is what you would inevitably come up with if you started with probability theory, and then said, let's try to generalize it so…

To counter your enthusiasm I must say that I rather disliked his reasoning. My problem is essentially that what Aaronson's calls "the theory" is a somewhat bastardized version of quantum mechanics that might suffice for quantum computing but, in my opinion, not for physics. I discussed the difference earlier: https://news.ycombinator.com/item?id=38255476

I think this is a very common view, and a somewhat mistaken one.

Quantum mechanics is used in very different ways by people in quantum information, condensed matter, many body physics, quantum field theory, nuclear physics and may other (sub)fields.

Of course it will be difficult for a quantum information theorist if they try to apply what they know directly to a hydrogen atom, but (speaking from experience) it will also be quite difficult for someone trained in what you call Hermitian quantum mechanics to directly apply what they know to quantum field theory, or quantum information or any other subfield that uses different language.

I strongly disagree with your summary "if you know Hermitian quantum mechanics then unitary quantum mechanics is conceptually straightforward. If you know unitary quantum mechanics then you will have a lot of new concepts and mathematics to learn before you understand hermitian quantum mechanics".

I challenge anyone trained in Hermitian quantum mechanics to make progress on (for example) proving or disproving the generalised quantum Stein's lemma, or any of the unsolved problems here https://arxiv.org/abs/2002.03233 using those methods.

Re: On the Double-Slit Experiment and Quantum Interference in the Wolfram Model (2020)

#33

Post by evanb »

luc4sdreyer wrote: post #12
evanb wrote: post #6

Earlier quoted context omitted.

That's not the kind of model it is. The standard model is one example of a quantum field theory. You should think of Wolfram's idea as a different formalism (ie. not QFT), not a different example. It so happens that Wolfram's multiway model (allegedly, I can't evaluate it fairly for myself) also contains GR as a low-energy limit. It's like inventing a new operating system (we currently have 3ish, Newtonian, Quantum,…

>If known programs cannot run on this new OS then it is defective. I understand the problem is that, like String Theory, this framework has a practically unlimited supply of variables that can simply be tuned to fit existing experiments, while not offering any way to be tested.

Indeed! But it is beneficial to have additional formalisms; it gives you hints about what kind of modifications to 'normal' physics might be possible.

Re: On the Double-Slit Experiment and Quantum Interference in the Wolfram Model (2020)

#35

Post by meindnoch »

Ste_Tokyo wrote: post #3

[flagged]

It cannot even explain the standard model and/or general relativity either. It's a (hyper)graph rewriting system, that they say can reproduce existing physics with some set of rules and some initial conditions.

Which is tautologically true. Any Turing complete system (e.g. Conway's Game of Life) can reproduce the physical world with large enough memory and enough time.

Re: On the Double-Slit Experiment and Quantum Interference in the Wolfram Model (2020)

#36

Post by andrewgleave »

danbruc wrote: post #28

I just skimmed the article for sanity checking and it looks more like crackpottery than science to me. Looking at the numbers on the graphs for single-slit diffraction, they are just binomial coefficient, at least mostly, not sure why there are pieces missing in the last rows. That is also what you expect when you repeatedly make binary decisions to go left or right. The article does not mention the binomial distribu…

And by the third slit simulation they seem to have refuted their own hypothesis.

Re: On the Double-Slit Experiment and Quantum Interference in the Wolfram Model (2020)

#37

Post by [deleted] »

danbruc wrote: post #28

I just skimmed the article for sanity checking and it looks more like crackpottery than science to me. Looking at the numbers on the graphs for single-slit diffraction, they are just binomial coefficient, at least mostly, not sure why there are pieces missing in the last rows. That is also what you expect when you repeatedly make binary decisions to go left or right. The article does not mention the binomial distribu…

[deleted]

Re: On the Double-Slit Experiment and Quantum Interference in the Wolfram Model (2020)

#40

Post by api »

mikk14 wrote: post #30
ImHereToVote wrote: post #20

Earlier quoted context omitted.

I wonder if there is a wave formulation for LLM's and transformers in general?

I don't know if this is exactly what you are thinking about, but there are some physicists working to understand what happens in transformers: https://proceedings.neurips.cc/paper_files/paper/2023/file/b...

Is it really true that we don't really understand why transformers work so well?

I mean we obviously understand how they work at a pure mechanical level, and we have this analogy with lookup (keys, queries, values) and "attention," but do we really get it? Can someone explain to me why that design works so much better than lots of other things like RNNs?

Or did we just tinker a lot (a method known as "graduate student descent") guided by mathematical hunches and loose analogies with biological brains until we found something that kinda worked?

It wouldn't be the first time. AFAIK we got the idea of wings from birds and figured out how to fly with them before we had a really solid fluid mechanical understanding of how and why wings work the way they do. We just thought "hmm so birds fly, so lets try stuff that looks a bit like that..."

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