Claude Shannon (1916-2001)
Claude Shannon was a mathematician and electrical engineer whose work underlies modern information theory and helped instigate the digital revolution. He was the first person to recognize how Boolean algebra could be used to great advantage in the relay circuitry found in telephone routing switches, paving the way for its use in all digital circuitry and laying the groundwork for the modern computer and other electronic devices. Shannon also successfully applied mathematical theory other scientific disciplines, resulting in advances in game theory, artificial intelligence and theoretical genetics.
Shannon was born in Petoskey, Michigan on April 30, 1916, and grew up in the nearby town of Gaylord. He demonstrated an advanced ability in mechanics as a child and delivered messages for Western Union in his teenage years. Following high school, Shannon enrolled at the University of Michigan. While pursuing dual degrees in mathematics and electrical engineering, he became familiar with the system of mathematical logic developed in the 1840s by English mathematician George Boole. His understanding of Boolean algebra would serve him well in his graduate work at the Massachusetts Institute of Technology (MIT), which began soon after he received his diploma from the University of Michigan in 1936.
At MIT, Shannon gained a position as a research assistant to the renowned scientist, Vannevar Bush. In 1930, Bush had built an analog computer he called a differential analyzer because its sole purpose was to solve differential equations, an often tedious process necessary for many engineering and physics applications. Despite being the best calculating machine available at the time, the differential analyzer was extremely complex, involving circuitry featuring more than 100 switches and usually requiring several people to operate. Shannon conceived of a simpler way to evaluate two-value systems of switches and circuits, via the application of two-valued Boolean algebra (values normally given as 0 and 1, or as true and false). He explored his ideas in his master’s thesis, entitled A Symbolic Analysis of Relay and Switching Circuits. A version of the thesis appeared in 1938 in Transactions of the American Institute of Electrical Engineers. Two years later the groundbreaking work, often described as one of the most significant theses of the 20th century, garnered Shannon the prestigious Alfred Noble Prize.
Shannon remained at MIT to pursue a doctorate. Impressed with his innovative application of mathematics to circuitry, Bush encouraged Shannon to take a similar approach to a very different type of problem. The result was Shannon’s dissertation, An Algebra for Theoretical Genetics, completed in 1940. The following year, Shannon began work at Bell Laboratories, where he chiefly worked in cryptography and secrecy techniques during World War II. He published a related paper, “Communication Theory of Secrecy Systems”, in 1949. This treatise incorporated some of Shannon’s earlier ideas regarding information theory, described in 1948 in “A Mathematical Theory of Communication”. The 1948 paper established much of the terminology used in the information field today, including the term bit to describe a binary digit. It also paved the way for other scientists to apply information theory to a variety of fields, ranging from biology to linguistics.
While continuing as a consultant at Bell, Shannon began teaching at MIT in 1956 and remained associated with the institution until 1978. In addition to his research there, Shannon became known for his active participation in more lighthearted pursuits, such as juggling and unicycle riding. He also developed a number of novel devices that aroused curiosity in others, such as a mechanical hand concealed in a box that would emerge only to flip off a switch that any passersby could flip on. Shannon’s sometimes frivolous nature spilled into an interest in gaming, and he and his wife, Betty, often visited Las Vegas with friends so they could try to beat the odds by applying game theory to blackjack and other games of chance. Shannon’s fascination with games was also expressed by his publication of a landmark paper describing how a computer could be programmed to play chess.
In his latter years, Shannon struggled with Alzheimer’s disease, finally losing the battle when he died on February 24, 2001. Because of his medical problems, he was not cognizant of the full impact his scientific efforts had on developments in communications and digital technology. Still, he had enjoyed a large amount of success and witnessed much of his work’s influence while he was still in good health. Shannon was the recipient of numerous awards and honors, such as the National Medal of Science (1966), the IEEE Medal of Honor (1966), the Kyoto Prize for Basic Science (1985) and various honorary degrees.