Not Even Wrong (String Theory)

A posting on Slashdot highlights an article on a book by Peter Woit who claims string theory is a “disaster for physics.”

But one thing they haven't done is coax a single prediction from their theory. In fact, “theory” is a misnomer, since unlike general relativity theory or quantum theory, string theory is not a concise set of solvable equations describing the behavior of the physical world. It's more of an idea or a framework.

Partly as a result, string theory “makes no new predictions that are testable by current—or even currently conceivable&mdashexperiments,” writes Prof. Smolin. “The few clean predictions it does make have already been made by other” theories.

Worse, the equations of string theory have myriad solutions, an extreme version of how the algebraic equation x² = 4 has two solutions (2 and -2). The solutions arise from the fact that there are so many ways to “compactify” its extra dimensions—to roll them up so you get the three spatial dimensions of the real world. With more than 10 raised to 500th power (1 followed by 500 zeros) ways to compactify, there are that many possible universes.

“There is no good insight into which is more likely,” concedes physicist Michael Peskin of the Stanford Linear Accelerator Center.