John Bardeen

John Bardeen (May 23, 1908 – January 30, 1991) was an American physicist. He is the only person to be awarded the Nobel Prize in Physics twice: first in 1956 with William Shockley and Walter Brattain for their invention of the transistor; and again in 1972 with Leon Cooper and John Robert Schrieffer for their microscopic theory of superconductivity, known as the BCS theory.

Born and raised in Wisconsin, Bardeen earned both his bachelor's and master's degrees in electrical engineering from the University of Wisconsin, before receiving a Ph.D. in physics from Princeton University. After serving in World War II, he was a researcher at Bell Labs and a professor at the University of Illinois.

The transistor revolutionized the electronics industry, making possible the development of almost every modern electronic device, from telephones to computers, and ushering in the Information Age. Bardeen's developments in superconductivity, for which he was awarded his second Nobel Prize, are used in nuclear magnetic resonance (NMR) spectroscopy, medical magnetic resonance imaging (MRI), and superconducting quantum circuits.

Bardeen is the first of only three people to have won multiple Nobel Prizes in the same category (the others being Frederick Sanger and Karl Barry Sharpless in chemistry), and one of five persons with two Nobel Prizes. In 1990, Bardeen appeared on Life magazine's list of "100 Most Influential Americans of the Century."