October 09, 2006

How String Theory Rules the World

An easily-forgettable fact—by which I mean a fact that I easily forget—is that science is to some extent a product of various social institutions, with all their quirks and imperfections. There are, I take it, all sorts of heated debates about to what extent this is the case. Either way, I thought this bit in Jim Holt's New Yorker piece on string theory illustrated a few things rather nicely:
String theorists dominate the country’s top physics departments. At the Institute for Advanced Study, the director and nearly all of the particle physicists with permanent positions are string theorists. Eight of the nine MacArthur fellowships awarded to particle physicists over the years have gone to string theorists.

Since the fall-off in academic hiring in the nineteen-seventies, the average age of tenured physics professors has reached nearly sixty. Every year, around eighty people receive Ph.D.s in particle physics, but only around ten of them can expect to get permanent jobs in the field. In this hypercompetitive environment, the only hope for a young theoretical physicist is to curry favor by solving a set problem in string theory. "Nowadays," one established figure in the field has said, "if you’re a hot-shot young string theorist you’ve got it made."
Maybe string theory is a good theory about the universe. Maybe it's even the best theory. But if it's not, in fact, the best theory, the odds of this fact being discovered anytime soon seem rather slim, seeing as how the people most likely to doubt the whole enterprise are the people least likely to have tenured positions and lots of free time to think about theoretical physics. No?

Anyway, my clumsy understanding is that sort of thing Holt describes has happened fairly frequently throughout history—I think that's what Thomas Kuhn's book was kinda sorta about—so maybe it's not a terrible problem and we just have to sit back and wait for some odds-defying, paradigm-shifting genius to set us all straight. Or maybe modern physics has become so advanced, requiring so much technical skill and prior learning, that social barriers to innovation have much more of an adverse impact nowadays than they did in, say, the 19th century. I guess I have no idea.

UPDATE: Read Sean Carroll's more-informed take. He says, "It seems worth emphasizing that the dominance of string theory is absolutely not self-perpetuating," and that string theorists are hired because of their interesting work, not due to some string-theory mafia. I'm not sure Carroll's view has to be incompatible with Smolin's (the people doing the hiring may not be string theorists, but their sense of what's interesting and worthwhile might be unduly influenced by other string theorists) but I'll leave this debate for someone who knows more about the topic.

MORE: Do check out the comments. Allen K. has some really smart things about what Smolin (and Holt) are missing.
-- Brad Plumer 11:18 PM || ||