So the landmark Poincare problem has been solved by a mathematician, and there’s much rejoicing across the land. But “it won’t help anyone build a bridge, aim a rocket, crack a code, or privatize Social Security. Mathematicians, no dummies, like to point out that, in some unspecified future, Perelman’s theorem might pitch in to help with these problems in ways that aren’t obvious now. But its real significance is like that of the fact that a times b is equal to b times a; it’s a basic structural statement about how the world is organized. If you prefer order to chaos, that’s something worth caring about.”