Claude Shannon

30 April 1916, Petoskey, Michigan, United States – 24 February 2001, Medford, Massachusetts, United States (aged 84)

American mathematician and engineer who founded information theory in 1948, defining the bit and the limits of communication over noisy channels. He took part in the Macy Conferences.

Life

Shannon grew up in Gaylord, Michigan, building model planes, radio-controlled boats and a barbed-wire telegraph to a friend’s house. He studied electrical engineering and mathematics at the University of Michigan, then went to MIT to work on Vannevar Bush’s differential analyzer. After a year at the Institute for Advanced Study in Princeton he joined Bell Labs, where he worked on cryptography and fire control during the war, and where he wrote his most famous paper. He returned to MIT as a professor in 1956. In later life he developed Alzheimer’s disease and died in a nursing home in Medford, Massachusetts.

Influences

Boole’s algebra of logic, met in an undergraduate philosophy course, gave him the key to his master’s thesis. Bush gave him his first research post. Earlier Bell Labs engineers, Harry Nyquist and Ralph Hartley, had begun to measure information; Shannon gave the measure a general theory. Von Neumann is said to have suggested the word “entropy” for his measure of uncertainty.

Contributions

His 1937 master’s thesis showed that Boolean algebra could describe and simplify relay and switching circuits, laying the foundation of digital circuit design. “A Mathematical Theory of Communication” (1948) defined information as the reduction of uncertainty, introduced the bit, and proved that every channel has a capacity below which messages can be sent with arbitrarily few errors despite noise. It founded information theory.

Shannon attended several Macy Conferences, where his mouse Theseus, which learned its way through a maze, was demonstrated in 1951. He was wary of the way “information” became a fashionable word, warning in 1956 against applying his theory where it did not belong.

Why it matters today

Every digital communication system, from mobile networks to data compression, rests on Shannon’s theorems. His deliberate exclusion of meaning from information is also the root of a long debate within cybernetics, taken up by Bateson and others, about what information leaves out.

Further reading

  • Claude Shannon and Warren Weaver, The Mathematical Theory of Communication (1949)
  • Jimmy Soni and Rob Goodman, A Mind at Play (2017)

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