John Bardeen

Born in Wisconsin in 1908, Bardeen studied electrical engineering before earning a physics Ph.D. from Princeton. After World War II he joined Bell Labs, where in 1956 he shared the first Nobel for the transistor - the invention that would underpin everything from telephones to computers and launch the Information Age. He moved to the University of Illinois and kept working, this time on the puzzle of superconductivity. In 1972 he won again, with Cooper and Schrieffer, for the BCS theory that now powers MRI machines and quantum circuits. He became the first person to take two Nobels in the same field, a feat matched by only two chemists since. He died in 1991, a year after Life named him one of the century's most influential Americans.