Expect big things from Keith Schwab. Just don’t expect to hear much about them. Schwab has advanced quantum physics with two seminal discoveries: At the University of California, Berkeley, he devised ways to exploit the quirky quantum behavior of a frictionless fluid called superfluid, which could lead to a superaccurate gyroscope, important for space navigation and to measure minute changes in the earth’s rotation. Then, at Caltech, he became the first to measure the fundamental unit of heat flow, a constant that will limit nanoscale devices. That discovery was the subject of filmmaker Toni Sherwood’s 2000 documentary The Uncertainty Principle, popular at film festivals. Schwab lowered his profile when he joined the tight-lipped National Security Agency’s quantum computing initiative in College Park, MD. Its goal: a quantum computer, which could have unparalleled code-breaking power. Schwab is also building nanoscale machines to demonstrate another of physics ’bizarre properties: superposition, a particle’s ability to exist in two places at once. Schwab’s work is unclassified—for now.