Director, Exploratorium, San Francisco, California, Frank Oppenheimer had three overlapping careers in science. He was first a brilliant researcher in nuclear, cosmic ray, and particle physics. He then became a distinguished teacher and innovator in laboratory instruction. He was finally the creator and guiding genius of a remarkable display of teaching by perception at the Exploratorium at the Palace of Fine Arts in San Francisco. In that undertaking, he gave San Francisco a participatory museum, a masterpiece of science, humanism, art, and technology, all in a perpetually unfinished collection. Oppenheimer started on his careers with a BA from John Hopkins in 1933, joining the Cavendish Laboratory at Cambridge from 1933 to 1935, and receiving a PhD in physics at Caltech in 1939. He was a member of the Manhattan Project, a high school science teacher, a Guggenheim Fellow, a Fellow of the American Physical Society, and a professor of physics at the University of Colorado.