All that changed December 16, 1947, when two physicists at Bell Labs named John Bardeen (1908–1991) and Walter Brattain (1902–1987) wired a different type of amplifier. This new amplifier was constructed from a slab of germanium—an element known as a semiconductor—and a strip of gold foil. They demonstrated it to their boss, William Shockley (1910–1989), a week later. It was the first transistor, a device that some people have called the most important invention of the twentieth century.
