A student's master's thesis became the birth certificate of digital computing
In 1937 Claude Shannon showed that on-off electrical switches could carry out any operation of Boolean logic. That insight underpins every digital circuit. Eleven years later he founded information theory and formally introduced the bit. As a boy in Michigan he had strung a telegraph along a barbed-wire fence.
Shannon was born in Petoskey, Michigan, and grew up in nearby Gaylord, son of a businessman and probate judge and a language teacher who became the high school principal. He built model planes and a radio-controlled boat, rigged a telegraph to a friend's house half a mile away using barbed wire, and delivered messages for Western Union. His hero was Thomas Edison, who turned out to be a distant cousin through the colonial leader John Ogden.
At the University of Michigan he met George Boole's logic and left in 1936 with degrees in both electrical engineering and mathematics. At MIT he worked on Vannevar Bush's differential analyzer, an analog computer tangled with improvised circuits. His thesis, A Symbolic Analysis of Relay and Switching Circuits, proved that switching circuits could solve any problem Boolean algebra could and ended with a design for a 4-bit adder. Howard Gardner later called it possibly the most important master's thesis of the century, and it won the 1939 Alfred Noble Prize.
During World War II he worked on codebreaking and secure communication, producing a paper seen as the dividing line between classical and modern cryptography and a foundation for later ciphers such as DES and AES. His 1948 paper, A Mathematical Theory of Communication, which Scientific American dubbed the Magna Carta of the Information Age, fed into the compact disc, the internet, mobile phones and even black hole physics. He co-invented pulse-code modulation and the first wearable computer.
Shannon also helped launch artificial intelligence. He co-organised the 1956 Dartmouth workshop, wrote on programming computers to play chess, and built Theseus, a machine that was the earliest electrical gadget to improve through trial and error. He taught at MIT from 1956 to 1978 and received the Kyoto Prize in 1985. Roboticist Rodney Brooks named him the 20th-century engineer who contributed most to 21st-century technology. He died on February 24, 2001.
Source: Claude Shannon
