WALTER BRATTAIN SIGNATURE, "Walter Brattain", on back of plain 3 x 5 postcard, postmarked Nov 7, 1972. Minor postal marks, otherwise in fine condition by co-recipient of the Nobel Prize for Physics for the discovery of the transistor.
Walter Houser Brattain (February 10, 1902 – October 13, 1987) was an American physicist at Bell Labs who, along with fellow scientists John Bardeen and William Shockley, invented the point-contact transistor in December 1947. The transistor is "the key enabler of modern electronics". The three men received the Nobel Prize in Physics in 1956 "for research on semiconductors and the discovery of the transistor.