Esoteric Dissertations from a One-Track Mind

November 15, 2007

Garrett Lisi and a Theory of Everything

Filed under: media, science — Tags: , , — codesmithy @ 3:22 pm

Telegraph has an article titled “Surfer dude stuns physicists with theory of everything.” The title is misleading and sensationalist, as is par for the course for the media. Garrett Lisi is 39 and while he spends time surfing and snowboarding, he does have a doctorate in theoretical physics from University of California, San Diego.

A Theory of Everything attempts to explain all the fundamental interactions of physics: gravity, strong nuclear force, weak nuclear force and electromagnetic force. The current state of knowledge is represented in the Standard Model of Fundamental Particles and Interactions. A Theory of Everything would have to match the Standard Model and unify the fundamental interactions. String theory apparently has a way do this also. However, a weakness of string theory is that it has not been experimentally verified, and remains difficult to do so.

Lisi starts off with a simpler premise: is there a way to describe the fundamental particles and their interactions in a coherent mathematical system without involving entities that we haven’t directly observed like strings? Lisi showed how this could be done with an E8 Lie algebra.

Is this the “Theory of Everything?” It appears to be plausible, although that doesn’t mean it is correct. However, it is attractive because it has a degree of elegance (due to E8’s symmetry and consequent lack of exceptionalism), minimalist assumptions, and apparently testable predictions. None of this proves Lisi is correct, but following the sensibilities of Occam’s razor we should prefer it tentatively and if it fails, then it should give us better insights into why.

This isn’t to say that if Lisi is correct theoretical physics is over either. In fact, the paper leaves some aspects unexplained, such as how he had to massage E8 to match the standard model for the interactions. However, I don’t find this completely discrediting because E8 does match the observed numbers. Lisi just doesn’t have a complete explanation for why this occurs, yet. As with almost any scientific explanation, it creates almost as many problems as it solves, however progress has still been made.

For more information discussion see:

Backreaction

A discussion on Physics Forums

The actual paper is linked from the blog and forum. I don’t want a trackback to my site for fear of trolls like “Lumo.” Also because I am wholly unqualified to comment on the overall veracity of the paper. I am simply trying to get my head around the concepts for something that doesn’t appear to be all hype at first glance, unlike other discoveries the media plays up. Given the reaction from the physics community, I think it is clear it shows some promise. Regardless, it does need to be treated with skepticism, but when the Large Hadron Collider comes online around summer 2008, we will know better, if not sooner.

Here is New Scientist article on E8 and a sample excerpt.

Unified theory

Adams and 17 other researchers solved the problem in a four-year project using a supercomputer at the University of Washington in Seattle. Their resulting map of E8 contains 60 gigabytes of information.

“This is an impressive achievement,” said Nicolai. He adds that the unique structure of E8 might help in the quest for a unified theory of gravity and the other forces in nature. This is because the underlying symmetries of the unified theory, if it really exists, will have to be complicated and unique.

“It will require an extremely special structure, mathematically speaking,” says Nicolai, “and E8 is an example of a symmetry that might fit the bill.”

So, Lisi’s claims should be thought of in this context. Not that what he did was an unthinkable idea, but rather having the proper background and skill to figure out how E8 does match a theory of everything. The alternative is that he could just be wrong.

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1 Comment »

  1. I think the introduction to the paper gives it away already:

    “We exist in a universe described by mathematics” ……. “The mathematics of the universe should be beautiful”.

    This seems to be just another case of mathematical mysticism and should not qualify as rational science (even it appears to reproduce certain aspects of reality). The scheme suggested reminds me vaguely of astrological models and Kepler’s attempt to explain the solar system in terms of regular polyhedra (see http://www.hps.cam.ac.uk/starry/keplerastrol.html , http://hyperion.cc.uregina.ca/~astro/Kepler_poly.html ) and we all know what the scientific status of this is nowadays.

    Mathematics should be a tool, not an end in itself.

    Thomas
    http://www.physicsmyths.org.uk

    Comment by Thomas Smid — November 18, 2007 @ 11:10 am


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