Growing mold in a bathtub is not usually known to attract students to physics, but it did start Donald Kerr, deputy director for science and technology at the Central Intelligence Agency, on a career path to science. As a young boy, Kerr was introduced to mold when he met a bacteriologist while on a family vacation to Cape Cod, Massachusetts. That chance encounter led Kerr to a PhD in plasma physics from Cornell University in 1966.