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Comment by smaddox | Hacker News Reader

So much negativity and character assassination in the comments here. Would be great if people could focus on the content of the article.

The work Wolfram, Gorard, et. al have been doing on this is incredibly fascinating and mind bending. And I love that they are live streaming and posting videos of their working sessions so that non-academics can see how this kind of research is done.

Regardless of whether this approach leads to new experimental predictions, it's important in that it's a fundentally computational model of physics that reproduces general relativity and quantumechanics.

The concepts of multiway graphs and causal invariance are also valuable as ways to model and study nondeterministic computations; they turn such computations into objects with an underlying structure. And there are absolutely consequences for computer science and mathematics, in general, in studying such models.

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I had actually read the article and here is my take:

1)Almost any mathematical abstraction can be used to match existing understanding of physics. Graphs, or groups or cellular automata. It is not wrong to try different kinds of those abstractions and there is nothing wrong with Wolfram's ideas in this department.

2) What matters is if you can deliver new insights from your model - be it general relativity, quantum mechanics or hypergraphs. Here his theory is extremely weak. Only two numerical values have been offered and they are experimentally non-testable as they are 50 orders of magnitude smaller than even corresponding Plank units (!) There are plenty of fringe theories with better predictive ability.

As far as I am aware, this is the first and only discrete and computable model of physics capable of reproducing even one of general relativity or quantum mechanics, let alone both in a fully unified way. Are there others that I am not aware of?

Edit: and in case it needs to be said, we now have had about 30 years of research into string theory and related theories without a single testable prediction. I agree that testability is critical, but every theory of physics beyond the standard model is lacking there.

The article says it does, but doesn't show how. It is extremely light on technicalities.

The article is a high-level summary of the past year and a half of work. If you want to see the derivations, you have to read the research papers, which are available from the website: https://www.wolframphysics.org/

In particular, the three documents linked at the top of https://www.wolframphysics.org/technical-documents/

Need a read to what real physicist thinks on it, especially the second and third paper. I am not smart enough to understand most of it, honestly.

I'm certainly not claiming to be a "real physicist", whatever that is, but I'm involved in the project (I actually named and continue to work on the "token-event graphs" that Max Piskunov developed for his local multi-way systems), and I don't think the project has convincingly shown yet how the basic ingredients of Hilbert spaces, complex amplitudes, operator algebras, density matrices, etc. are supposed to work. Which to me is an extremely important first step. I think we'll fix that, though.

I think his stuff must be in conflict with standard quantum mechanics, since his systems can be simulated with a polynomial number of steps per "generation". That means quantum computers won't work, since they can implement algorithms that are believed to have super-polynomial complexity on classical computers. Granted, quantum computers are a rather extreme prediction of QM and we don't really know whether they can work, so the discrepancy is ok if he can still explain things like the double slit experiment. It's ok to say standard QM is non-physical at the level of quantum computers. I didn't notice if he comes out and says so though.

Each possible update path can be stimulated in linear time (or is it polynomial? It depends how you measure the cost of searching for a location to apply the update rules, and weather the update rules are fixed), but stimulating the full multiway system has unbounded complexity in the general case.

The reason they suspect that quantum computers will not provide an inherent speedup has to do with the cost of "completion", i.e. measurement, which is explicit and finite in these models.

String theory suffers from exactly the same problem, yes. Here, Wolfram's theory is no worse than string theory.

+1 I found the article fascinating. I interviiewd Stephen for a podcast last year mainly talking about language design (https://www.infoq.com/podcasts/wolfram-language-mathematica/) and found him to be both extremely charming, very interesting, and extremely smart. He was an absolute pleasure to interview and I would have loved to have talked for longer.

> So much negativity and character assassination in the comments here

The bog standard response to anyone who attempts to do something new. Thankfully Wolfram has a thick skin.

It's a reasonable guess. Most who attempt this fail miserably. It's just that survivorship bias and a good dose of holywood spectacle make it feel like in the end the oddball with the weird idea will persist.

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