[neutralino]

I found this rather interesting paper today that had been reposted to the arxiv. It's by a guy called Max Tegmark, and is called, as the thread title suggests, The Mathematical Universe. Here is the abstract:

I explore physics implications of the External Reality Hypothesis (ERH) that there exists an external physical reality completely independent of us humans. I argue that with a sufficiently broad definition of mathematics, it implies the Mathematical Universe Hypothesis (MUH) that our physical world is an abstract mathematical structure. I discuss various implications of the ERH and MUH, ranging from standard physics topics like symmetries, irreducible representations, units, free parameters, randomness and initial conditions to broader issues like consciousness, parallel universes and Godel incompleteness. I hypothesize that only computable and decidable (in Godel's sense) structures exist, which alleviates the cosmological measure problem and help explain why our physical laws appear so simple. I also comment on the intimate relation between mathematical structures, computations, simulations and physical systems

It's quite a mathematically complex paper, but does have some nice diagrams throughout. There is also a shorter version of the paper available that was written for New Scientist entitled: Shut up and calculate. This non-technical, so may be better for the lay-reader. Here is the abstract:

I advocate an extreme "shut-up-and-calculate" approach to physics, where our external physical reality is assumed to be purely mathematical. This brief essay motivates this "it's all just equations" assumption and discusses its implications.

These papers are both very interesting. I like Tegmark, as he's a little different to most scientists; he's more philosophical.

I'll post more when I've read the paper completely, but please feel free to comment if you've read either paper, or are interested.

[Profpat]

I agree with you Neutralino, about Max Tagmark. He is one of my favorite physicists. It was his article on Parallel universes that I found so interesting and informative. He is now at MIT, prior to that he was at UPenn. Some of his "stuff" may now be the intellectual property at UPenn. However he has a very interesting home page filled with "stuff" at:
( http://space.mit.edu/home/tegmark/no...ontlinkme.html )

Best to all,

Pat

[neutralino]

Thanks, Pat. The first time I heard of him was when I stumbled upon a paper of his entitled On the dimensionality of spacetime (warning: that links straight to a .pdf document) which I found to be a very interesting read.

[neutralino]

I've reopened this thread, for the time being, in case anyone wishes to discuss the topic.