Has Physics Turned Keatsian with String Theory?

In the New Yorker, Jim Holt looks at two new books assailing string theory, Lee Smolin’s The Trouble with Physics: The Rise of String Theory and Peter Woit’s Not Even Wrong: The Failure of String Theory and the Search for Unity in Physical Law.

In their books against string theory, Smolin and Woit view the anthropic approach as a betrayal of science. Both agree with Karl Popper’s dictum that if a theory is to be scientific it must be open to falsification. But string theory, Woit points out, is like Alice’s Restaurant, where, as Arlo Guthrie’s song had it, “you can get anything you want.” It comes in so many versions that it predicts anything and everything. In that sense, string theory is, in the words of Woit’s title, “not even wrong.” Supporters of the anthropic principle, for their part, rail against the “Popperazzi” and insist that it would be silly for physicists to reject string theory because of what some philosopher said that science should be. Steven Weinberg, who has a good claim to be the father of the standard model of particle physics, has argued that anthropic reasoning may open a new epoch. “Most advances in the history of science have been marked by discoveries about nature,” he recently observed, “but at certain turning points we have made discoveries about science itself.”

Is physics, then, going postmodern? (A Harvard, as Smolin notes, the string-theor seminar was for a time actually called “Postmodern Physics.”) The modern era o particle physics was empirical; theor developed in concert with experiment. Th standard model may be ugly, but it works, s presumably it is at least an approximation of th truth. In the postmodern era, we are told aesthetics must take over where experimen leaves off. Since string theory does not deign t be tested directly, its beauty must be th warrant of its truth.