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Claude E. Shannon

Claude Elwood Shannon (April 30, 1916 - February 24, 2001) has been called "the father of information theory", and was the founder of practical digital circuit design theory.



Shannon was born in Petoskey, Michigan and was a distant relative of Thomas Edison. While growing up, he worked as a messenger for Western Union.

In 1932, Shannon began studying at the University of Michigan, where he eventually encountered a course that introduced him to the works of George Boole. He graduated from the university in 1936 with two bachelor's degrees, one in electrical engineering and one in mathematics, and he then moved to the Massachusetts Institute of Technology for graduate school, where he worked on Vannevar Bush's differential analyser, an analog computer.

In his 1937 MIT master's thesis, A Symbolic Analysis of Relay and Switching Circuits , Shannon proved that Boolean algebra and binary arithmetic could be used to simplify the arrangement of the electromechanical relays then used in telephone routing switches, then turned the concept upside down and also proved that it should be possible to use arrangements of relays to solve Boolean algebra problems. This concept, of utilizing the properties of electricity to do math, is the basic concept that underlies all modern electronic digital computers, and the thesis became the foundation of practical digital circuit design when it became widely known among the electrical engineering community during and after World War II. Contemporaneous experiments at the time were ad hoc and lacked the theoretical rigor that Shannon's paper supplied to later projects.

Professor Howard Gardner, of Harvard University, called Shannon's thesis "possibly the most important, and also the most famous, master's thesis of the century". A version of the paper was published in the 1938 issue of the Transactions of the American Institute of Electrical Engineers, and in 1940, it earned Shannon the Alfred Noble American Institute of American Engineers Award .

Flush with this success, Vannevar Bush suggested that Shannon follow him to Cold Spring Harbor Laboratory, to develop similar mathematical relationships for Mendelian genetics, which resulted in Shannon's 1940 PhD thesis at MIT, An Algebra for Theoretical Genetics . Shannon then joined Bell Labs until he returned to MIT in the 1950s.

In 1948 Shannon published A Mathematical Theory of Communication. This work focuses on the problem of how to reconstruct at a target point the information a sender has transmitted. In this fundamental work he used tools in randomized analysis and large deviations , which were in their nascent development stages at that time. Shannon developed information entropy as a measure for redundancy while essentially inventing information theory. His later book with Warren Weaver, The Mathematical Theory of Communication, is brief and surprisingly accessible to the non-specialist. Another notable paper published in 1949 is Communication Theory of Secrecy Systems, a major contribution to the development of a mathematical theory of cryptography. He is also credited with the introduction of the Sampling Theory, which is concerned with representing a continuous-time signal from a (uniform) discrete set of samples.

Shannon is known for his thinking prowess; many have testified that he was able to write entire academic papers by dictating from memory alone, without correction. He was known to rarely scribble his thoughts on paper or blackboard, preferring to work everything out in his head. Outside of his academic pursuits, Shannon was interested in juggling, unicycling, and chess. He also invented many devices, including a chess-playing machine, a rocket-powered pogo stick, a wearable computer to predict the result of playing roulette [1], and a flame-throwing trumpet for a science exhibition. He met his wife Betty when she was a numerical analyst at Bell Labs.

From 1958 to 1978 he was a professor at MIT. To commemorate his achievements, there were celebrations of his work in 2001, and there are currently three copies of a statue of Shannon: one at the University of Michigan, one at MIT in the Laboratory for Information and Decision Systems and one at Bell Labs.

Awards and honors

See also


  • C. E. Shannon: A mathematical theory of communication. Bell System Technical Journal, vol. 27, pp. 379-423 and 623-656, July and October, 1948.
  • Claude E. Shannon and Warren Weaver: The Mathematical Theory of Communication. The University of Illinois Press, Urbana, Illinois, 1949. ISBN 0252725484

External links

Last updated: 08-24-2005 00:58:58