Michael Viscardi is the kind of applicant other Harvard hopefuls pray doesn't exist. He's concertmaster and a violinist with the local youth symphony. And he just won, at 16, the $100,000 Siemens Westinghouse prize for his new theorem based on a classic late-19th-century problem by mathematician Lejeune Dirichlet. "Basically," Viscardi says, "I studied the Dirichlet problem for the Laplace operator on any simply connected, bounded domain in two dimensions given rational holomorphic boundary data. I came up with and proved a new theorem that characterizes all such domains for which the solution is rational." Viscardi's solution models how heat travels across metal surfaces and--as we saw immediately--could improve space-shuttle and airplane-wing design, and aid in the construction of light rails and subways. Viscardi and his mentor, professor Peter Ebenfelt of the University of California San Diego (the home schooler attends math classes there), worked for six months on the Dirichlet problem, using, Viscardi says, "just some paper, a chalkboard, and our brains." As for Harvard, yes, it took him.