attention dr. mmcirvin

[rone]

I seek your opinion on Garrett Lisi's "An Exceptionally Simple Theory of Everything" (other physicists or physics fans are welcome to chime in).  Thanks to venividi for bringing it to my attention.

Comments

[dwenius.livejournal.com]

A cow-orker who actually groks a few of the simple Lie groups (which is a few more than me) says that the paper is less "here is a rigorous argument" and more "look at this fascinating thing I noticed." It mixes several different types of abstraction to place the fundamental particles on the e8 graph (wikipedia it, ooh, pretty, just solved this year), but he leaves out a lot of the hard work to make it obvious/proved. Also, if Lee Smolin likes it, I am immediately skeptical.

On the other hand, it's testable, unlike Strings. So when the LHC comes online, we may know fairly quickly if he's on to something. He ran out of fundamental particles with about 20 empty spots on his read of the E8 graph. By using the E8 like a partially filled out periodic table of fundamental particles, he's created plenty of test cases.

[nothings.livejournal.com]

The thing is, an article I saw on this linked to a March 2007 article about the mapping of the e8 graph... which made frequent reference to the fact that physicists in particular were interested in it, especially re: unification.

So either he's just stating a (semi-)conventional wisdom out loud, or if he actually did some interesting stuff, I imagine there were other physicists working on the same thing as well.

[doctroid.livejournal.com]

Funny, I was going to say "it sounds like crackpottery, but if Smolin says it's a good theory worth investigating, it probably is." Not that I think all of Smolin's ideas are right (indeed, I barely understand any of them) but he's certainly competent to distinguish crackpots from people with good, out-of-the-mainstream ideas.

Strings are not completely untestable.

[dwenius.livejournal.com]

Last I read (Greene's _Fabric of the Cosmos_), even the LHC will fall well short of the energies necessary to observe strings. and the secondary effects/predictions of string theory, which may be observable in the LHC, are not strictly limited to string origin.

Happy to be wrong. This is just a hobby and the math is way beyond me.

[reddragdiva]

Oh yeah. I crapped out on physics maths around first year undergraduate (nineteen years ago). But the paper is beautifully structured - Lisi knows how to tell a story. And he is keenly aware of every hole in this work-in-progress, and will quite readily go "oh well" should it fail to get anywhere.