UNSTRUNG.

It is the best of times in physics. Physicists are on the verge of obtaining the long-sought Theory of Everything. In a few elegant equations, perhaps concise enough to be emblazoned on a T-shirt, this theory will reveal how the universe began and how it will end. The key insight is that the smallest constituents of the world are not particles, as had been supposed since ancient times, but "strings"--tiny strands of energy. By vibrating in different ways, these strings produce the essential phenomena of nature, the way violin strings produce musical notes. String theory isn't just powerful; it's also mathematically beautiful. All that remains to be done is to write down ...