Claude Shannon

American mathematician and computer scientist

• Born: April 30, 1916; Petoskey, Michigan
• Died: February 24, 2001; Medford, Massachusetts

Twentieth-century American mathematician and computer scientist Claude Shannon is often called “the father of information theory” in recognition of his pioneering work in the field of networked electronic communications and his application of Boolean logic to computer design. He is also credited with the creation of digital computers and their binary circuit design.

Primary fields: Computer science; mathematics

Specialties: Information theory; logic; mechanics; mathematical analysis

Early Life

Claude Elwood Shannon was born on April 30, 1916, in Petoskey, Michigan, the son of Claude Shannon Sr. and the former Mabel Wolf. Shannon is a distant cousin of American inventor Thomas Edison. His father’s family was among the first European settlers of New Jersey; his mother was the child of German immigrants. Shannon’s father worked as a businessman, attorney, and probate judge. His mother was a language teacher who served as the principal of Gaylord High School in Gaylord, Michigan, the town in which he spent his first sixteen years.

As a student, Shannon excelled in science and mathematics. At home, he loved to work on mechanical devices, building a radio-controlled model boat, model planes, and a telegraph that connected to his friend’s home half of a mile away.

In 1932, at age sixteen, Shannon enrolled at the University of Michigan, where his sister Catherine had recently earned a graduate degree in mathematics. He began studying the work of nineteenth-century British mathematician and logician George Boole, who established logic as a field of mathematics and created what is now known as Boolean algebra. In 1936, Shannon graduated from the University of Michigan with two undergraduate degrees, one in mathematics, and the other in electrical engineering.

In the fall of 1936, he enrolled at the Massachusetts Institute of Technology (MIT) as a graduate student and took a part-time position as a research assistant in the electrical engineering department. At MIT, Shannon began working with a differential analyzer designed by engineer and MIT professor Vannevar Bush. The analog computer was then the most advanced calculating machine ever devised. While working on the analyzer’s intricate relay circuits, Shannon began to theorize that a simpler relay and switching circuit system could be designed.

Life’s Work

A relay is composed of three parts: a spring, a moveable electrical contact, and an electromagnet. While relays are relatively simple devises, the relay circuits that controlled the functioning of early analog computers were not. As a research assistant, Shannon considered these complex and improvised relays to be inefficient. He and his fellow assistants spent more time keeping them in good working order than running computations through the analyzer. During the summer of 1937, as he worked at Bell Laboratories in New York City, he realized that far more effective relays could be made by using Boolean algebra, because the algebra employed a simple, two-value (or binary) system. By manipulating just two symbols, 1 and 0 (with the 1 representing “on” and the 0 representing “off”), electrical switching circuits could be made effective and logical, instead of in the ad-hoc way in which these relays were then being assembled.

Shannon elaborated on these trailblazing ideas in his 1937 master’s thesis, “A Symbolic Analysis of Relay and Switching Circuits,” which helped lay the foundation for the development of digital computers and digital switching circuits. While the paper’s central focus was how binary systems could improve the complicated switching circuits then needed by the Bell Telephone Company, fellow engineers and mathematicians quickly understood the broader implications of Shannon’s work.

Bush was among the first people to recognize the importance of Shannon’s work. In addition to suggesting that Shannon switch from MIT’s electrical engineering department to the mathematics department, he urged him to look at the genetic research then being conducted at the Carnegie Institution in Cold Spring Harbor, New York. Shannon, like Bush, quickly understood that Boolean algebra could also help organize genetic information. After spending the summer of 1939 in Cold Spring Harbor, Shannon wrote his doctoral thesis, “An Algebra for Theoretical Genetics.” In 1940, he earned a doctorate in mathematics and a master’s in electrical engineering from MIT.

Following his graduation from MIT, Shannon began working as a research fellow at the Institute for Advanced Study in 1940. He then returned to Bell Laboratories in the spring of 1941. By year’s end, the United States had entered the Second World War and Bell, like all other major US companies, turned its attentions to the war effort. During the war, Shannon worked on secrecy systems aimed at preventing enemy forces from neutralizing or countering US weapons systems. Through this work, Shannon became a skilled cryptographer. He also helped to develop fire control systems for anti-aircraft use, and anti-aircraft directors, devices that pinpointed enemy planes or rockets and then calculated the aim of counter missiles.

Shannon’s wartime work helped shape the development of information theory in what has been called his masterpiece, A Mathematical Theory of Communication. In this seminal work, first published in 1948, Shannon demonstrated a practical way to transmit messages electronically without their being garbled. In order to do this, Shannon had to define information. He eschewed the idea that information must be conceived of something specific having to do with its content, like letters, numbers, or video. Instead, he held that information need be nothing more than the easily transmitted 1s and 0s of Boolean algebra. The ideas he developed in A Mathematical Theory of Communication serve as the building blocks of digital computing. Shannon’s ideas have also been applied in fields such as biology, for example, so that scientists now think of strands of DNA as pieces of information that form the collective whole of a given organism.

In 1956, Shannon joined the faculty at MIT, where he served until 1978. During this period, he conducted work at MIT’s Research Laboratory of Electronics. Shannon built numerous devices, including a motorized pogo stick, a rocket-powered Frisbee, and a box he called the “Ultimate Machine,” consisting of a single switch on a box. When the switch was flipped on, a hand popped out of the box, turned the switch off and slid back into the box. In 1950, he developed one of the first computer chess programs, which he used to challenge chess champion Mikhail Botvinnik in 1965. (Shannon’s computer was defeated by Botvinnik in forty-two moves). In 1950, Shannon created one of the world’s first artificial intelligence (AI) devices, an electronic mouse he called Theseus, which used relay circuits to wind its way through a flexible maze. The mouse was able to learn how to get through the reshaped maze because it was programmed to first find a familiar location and then look for a way out. Shannon’s 1953 paper, “Computers and Automata,” is considered a primary document in the AI field.

In 1949, Shannon married Mary Elizabeth (“Betty”) Moore, a numerical analyst he met while working at Bell Labs. The couple had four children together. During his lifetime, Shannon received numerous awards for his work, including the engineering award known as the Alfred Nobel Prize (1940), the National Medal of Science (1966), and the Kyoto Prize for Basic Sciences (1985). He was also a member of a number of several scientific associations, including the National Academy of Sciences.

Shannon died on February 24, 2001 in Medford, Massachusetts.

Impact

Although Shannon is not as famous as Albert Einstein, his contributions to digital computing and information theory are as fundamental to these fields as Einstein’s general theory of relativity has been to physics.

By developing new ways to employ Boolean logic’s binary system of 1s and 0s, Shannon helped create a streamlined and logical architecture for both computer hardware and software. Every modern digital device—computers, cell phones, DVDs, and GPS systems—employs this two-symbol logic in order to work properly. The circuits (or hardware) within these devises transmit information in this binary way, just as the information (or software) functions through a system of 1s and 0s.

Shannon’s establishment of information theory fundamentally revolutionized the way science conceives of information. Prior to Shannon, information was thought of as words on a page, notes in a piece of music, pictures on a television screen. Shannon revealed that information could be simplified and transformed into a stream of 1s and 0s in order to be communicated and processed electronically. He even described the white spaces between words as the twenty-seventh letter of the alphabet because, as specific bits of information, they reduce confusion in written language. Shannon’s work has had far-ranging applications in biology, literature, psychology, and phonetics.

Bibliography

Gleick, James. The Information: A History, a Theory, a Flood. New York: Pantheon, 2011. Print. Discusses how the concept of what information is has evolved with the development of communications technology, profiling Shannon along with a number of innovators, including Charles Babbage, who invented the first mechanical computer.

Nahin, Paul J. The Logician and the Engineer: How George Boole and Claude Shannon Created the Information Age. Princeton: Princeton UP, 2012. Print. Examines the lives of George Boole, the nineteenth-century British mathematician and logician, and Shannon, who used Boole’s logic to develop information theory and modern digital computing.

Poundstone, William. Fortune’s Formula: The Untold Story of the Scientific Betting System that Beat the Casinos and Wall Street. New York: Hill, 2005. Print. Describes how Shannon and fellow scientists Ed Thorpe and John Kelly (who developed the “Kelly criterion” of investing), employed information theory to betting and stock market investments to amass personal fortunes.