String theorist sparks a spat

By Matin Durrani

There’s nothing better in physics than a bit of a ding-dong, and you can, of course, rely on string theory to supply the ammunition for it.

String theory, after all, polarizes opinion seemingly like nothing else: its proponents deem it a rigorous framework that could unify the fundamental forces, while its critics dub it preposterous guff that makes no testable predictions of the world.

One of string theory’s masterminds – Michael Duff of Imperial College London – has now hit back at his critics with a paper in a special issue of the journal Foundations of Physics published to mark 40 years of the theory. You can read Duff’s 19-page paper either in Foundations of Physics, which is open to all until 31 December 2011, or as a preprint on arXiv.

Duff reckons that “much of the criticism has been misguided or misinformed” and goes on to outline why string theory is valid, before taking a pop at various critics – not only other researchers, notably Lee Smolin and Peter Woit (who he calls “a single-issue protest group”), but also the media, including Physics World.

Duff’s complaints about the media are a little confused in my eyes, stemming in part from the fact that journalists paid too much attention, in Duff’s eyes, to the work of Garret Lisi, who in 2007 published a (non-peer-reviewed) paper entitled “An exceptionally simple theory of everything” that controversially claimed to unify “all fields of the standard model and gravity”.

Although Duff says Lisi is “by no means a crackpot”, he complains that “journalists love [crackpots]” and seems to suggest it was for that reason that so much coverage was given to Lisi’s work, even though the latter does not have much to do with string theory. All I can say is that we at Physics World are no fan of crackpots either.

Duff’s paper has, not surprisingly, drawn a vigorous response from Woit himself, whose blog post can be read here. Woit thinks that attempts by Duff and other string theorists to respond to their critics has “damaged not just the credibility of string theory, but of mathematically sophisticated work on particle theory in general”.

If this little spat leaves you none the wiser, my advice is to read this Physics World feature on string theory by Matthew Chalmers.