The Times of London recently sent one of its reporters out to a pub to learn about string theory from Michael Green, with results available on-line here. Green does a good job of trying to explain some physics over a few beers, and admits that:
I think, historically, when there has been a big change in a theory there is usually some qualitatively new phenomenon which will distinguish the theory. This has not happened for string theory, which is one of the reasons some people wonder whether it is real physics.
There’s an associated slide show that supposedly gives a step-by-step guide to string theory. It explains that there are ten extra dimensions of very small size, necessary because:
Beautiful as the idea sounds, when string theory is applied in the ordinary three spatial dimensions it doesn’t work mathematically, predicting the wrong numbers for constants such as pi and the speed of light. It also predicts that the whole Universe should disappear.
I do wonder what string theory’s prediction for the value of pi is…
According to the Times, the LHC has something to do with all of this, since:
Scientists hope that the smashing together of particles at the Large Hadron Collider may reveal hints of the strings lying within them.
Over at the Los Angeles Times, Steve Giddings somehow neglects to mention string theory while arguing that the LHC
In case all of these discoveries seem a bit abstract and useless, there’s the possibility of
Over at Uncertain Principles, some of the Giddings arguments about spin-offs leave Chad Orzel rather grumpy.
Finally, also on the nothing-to-do-with-string-theory front, New Scientist has an article about this paper from Science, where the authors find some sort of relation I don’t understand between a representation of E8 and some phenomenon at the critical point of a quasi-one dimensional Ising ferromagnet.
Although E8 does show up in string theory calculations, observing the symmetry in magnetic crystal experiments does not provide any evidence for string theory itself, Konik says.
“The fact that you see this particular symmetry in this spin chain doesn’t say anything about string theory per se,” he says.