Transistor

The transistor is a solid-state semiconductor device that can amplify or switch an electrical signal, replacing the bulkier, more fragile, and more power-hungry vacuum tube for most uses and becoming the basic building block of virtually all modern digital electronics. The first working point-contact transistor was demonstrated at Bell Labs on 16 December 1947 by John Bardeen and Walter Brattain, working in a solid-state physics group whose research direction had been set by William Shockley. Shockley was not present for that first demonstration but went on to develop the more easily manufactured junction transistor in 1951, and the 1956 Nobel Prize in Physics for the transistor's invention was shared by all three men. Shockley's later career is more mixed than his co-inventors': from the 1960s onward he became a prominent public advocate of eugenics and race-based pseudoscience about intelligence, a turn widely and directly rejected by the scientific community. Shockley is now recorded on this atlas as a scientist in his own right, where his transistor work and this later history are told in full.