## Saturday, October 24, 2009 ... //

### Guardian: interview with Michael Green

Aida Edemariam of The Guardian just published an interesting albeit imperfect interview with the new Lucasian professor of mathematics in Cambridge:

Michael Green: Master of the universe (click)
It argues that Green, who has been focused on theoretical physics since the age of 13, used to be a Harrison Ford's lookalike.

They recall how Green and Schwarz met in a CERN canteen, how everything suddenly made sense during a day in 1984, how string theory would have gone extinct without Green and Schwarz (Witten's words), and how the gospel about their success got to Princeton where the amazing guy called Edward Witten scooped them and wrote this paper (abstract) about the phenomenology of O(32) strings.

I think it is this paper that Green claims to have really sparked the revolution. Unlike most papers by Green and Schwarz from the early 1980s, I've never read this particular paper by Witten - that claimed to have obtained the right number and type of generations of the Standard Model fermions from type I theory. And frankly, although I can't read the full paper even now, it doesn't seem quite correct to me. Can you get realistic vacua from O(32) strings in this way?

Green says that the pace of research got much faster these days because they didn't have to compete with others which was kind of nice.

The journalist claims that
Green once said that one could "think of the universe as a symphony or a song – for both are made up of notes produced by strings vibrating in particular ways."
Green replies: "Did I?" Cutely enough, the article doesn't resolve the mystery. The solution is, of course, that Ms Edemariam confused Michael Green with Brian Greene (who says similar things often) and she still doesn't realize that. :-) I suspect that Green realized where the confusion came from.

Green describes the importance of unification in physics.

As a typical journalist, Ms Edemariam cannot forget about those two crackpots who published their popular books in 2006 and who became fashionable among the stupid people for a while.

Ms Edemariam thinks that some well-established mathematical facts about the number of solutions to some conditions are "absurd" (how mathematical facts can be "absurd" is not clear to me: ask her) and allows Green to respond.
Green dismisses these criticisms out of hand. "A couple of years ago there were a couple of books by two particular people who don't have any particular reason to be knowledgeable about the subject," he laughs.

"Woit is a blogger – he runs an anti-strings blog, he's an ex-physicist, a PhD I think. He's at Columbia – a systems manager or something. So he's not a professional physicist. He has strong views about string theory, which he's entitled to, and he blogs them. And good for him."

"The other one, Smolin, is a physicist who has a view of physics other than string theory and wants to promote that. And the media made a big song and dance about this, which seemed to me to be completely off-scale with what we experience anywhere in any university. The subject's thriving."
I have removed some garbage that Ms Edemariam has inserted in between Green's words to "improve them".

Of course, the journalist also wants to apply her "knowledge" that she has received from the crackpot books, so she says that there exists a "bias", Green had just proven it, and people should study different things. Green gives the obvious answer:
"People do what they feel is going to be productive," says Green. "It's all very well to say they should be doing something else. But there is nothing else."

Furthermore, string theory, Green contends, "isn't simply something that will, once tested, be either verified or disproved. It's become much more than that". It has, for example, provided a way to discuss the previously unexplained nature of radiation from black holes, which apparently contradicted the rules of quantum physics (otherwise known as Hawking radiation).

More usefully, from a day-to-day point of view, it may eventually increase our understanding of high-temperature superconductors, which, if they could be mass-produced, would mean we could transfer energy, such as electricity, fantastically cheaply (super-conductors mean no energy is lost as heat).
They continue to discuss somewhat barbarian recent proposals to link the funding for sciences to their contributions to the U.K. economy (which would be bad for theoretical sciences but even worse for social sciences). Green uses some stories about Faraday to explain that the path from amazing theoretical ideas to applications is often very indirect.

Like his parents, Green is an atheist, but he does get irritated by "ultra-atheists". Three simple paragraphs about string theory are added at the end.

By the way, Nude Socialist mentions the words of a few people, including string theorist David Tong. By the way, David could be the new Lucasian professor if you wanted to last him long. It would be a good choice but there would probably be some opposition, too.