The authors are right to say that physicists can get cliquish; that some of them swagger; that they frequently fool themselves and that science has become too risk-averse. On the other hand, dozens of astrophysicists, cosmologists, relativists and people who study fundamental particles and interactions in ways not related to string theory do quite nicely; some even dip into theory now and then. In fact, many highly esteemed physicists who formerly disdained string theory (Nobel laureates Steven Weinberg and Murray Gell-Mann among them) have become fans.
So it's hard to believe, as both authors charge, that physicists have been led like sheep to pursue a "failed theory," mostly by Edward Witten, now at the Institute for Advanced Study in Princeton and generally acknowledged genius -- and also a nice guy. (In addition to his multiple prizes in physics, Witten also won the Fields Medal -- the "Nobel Prize" of mathematics.)
True, Witten is highly influential. But it's hard to imagine him ruining an entire generation of physicists. They are not, in general, followers; getting them to agree on anything is like herding cats. They love nothing better than to prove each other wrong.
The claim that string theory can't be tested is serious; experiment is the ultimate arbiter of truth. But it's impossible to know what is ultimately testable. When the ghostly neutrino popped up in one of Pauli's equations, the physicist admitted he'd done "a terrible thing. I have postulated a particle that cannot be detected." Then in 1956, traces of neutrinos were seen in the wash of radiation spewing from newly commissioned nuclear reactors.
As for Woit's claim that string theory has "absolutely zero connection with experiment," experiments already planned for a new European particle accelerator will look for the existence of extra dimensions and extra families of particles -- both predicted by string theory. In fact, many statements about string theory in these books are plain wrong. To say, as Smolin does, that string theorists are not trying to figure out how space and time came into being will surprise the dozens who do just that. To say, as Woit does, that fundamental mysteries about neutrinos are being ignored will come as news to the dozens of physicists who've been working on these problems for years.
So what good, ultimately, is beauty? As the late physicist Victor Weisskopf said, "What's beautiful in science is that same thing that's beautiful in Beethoven. There's a fog of events, and suddenly you see a connection."
Neither Woit nor Smolin sees the beauty in string theory. But perhaps they haven't spent enough time in the fog. Theories often seem impenetrable at the time they are being discovered -- and clear and simple (and beautiful) only in retrospect. One of the strangest charges against Witten is that he's often openly muddled. Asked his opinion about a recent turn in string theory, he answered: "I just don't have anything incisive to say. I hope we will learn more." Smolin interprets this as Witten being "stumped." Perhaps it's a sign that he's thinking.
In the end, Smolin admits that he hasn't managed to do much better than string theorists, and his book is "a form of procrastination." One hopes he will soon dive back into the fog and start making connections.