 Title page | |
| Author | Claude E. Shannon |
|---|---|
| Language | English |
| Subject | Switching circuit theory |
| Genre | Computer Science |
| Publisher | MIT Press |
Publication date | 1938 |
| Publication place | United States |
| Text | A Symbolic Analysis of Relay and Switching Circuits online |
A Symbolic Analysis of Relay and Switching Circuits is the title of amaster's thesis written bycomputer science pioneerClaude E. Shannon while attending theMassachusetts Institute of Technology (MIT) in 1937,[1][2] and then published in 1938. In his thesis, Shannon, a dual degree graduate of theUniversity of Michigan, proved thatBoolean algebra[3] could be used to simplify the arrangement of therelays that were the building blocks of the electromechanicalautomatic telephone exchanges of the day. He went on to prove that it should also be possible to use arrangements of relays to solve Boolean algebra problems. His thesis laid the foundations for alldigital computing anddigital circuits.[4][5]
The utilization of thebinary properties of electrical switches to perform logic functions is the basic concept that underlies allelectronic digital computer designs. Shannon's thesis became the foundation of practicaldigital circuit design when it became widely known among theelectrical engineering community during and afterWorld War II. At the time, the methods employed to design logic circuits (for example, contemporaryKonrad Zuse'sZ1) weread hoc in nature and lacked the theoretical discipline that Shannon's paper supplied to later projects.
Shannon's work also differered significantly in its approach and theoretical framework compared to the work ofAkira Nakashima. Whereas Shannon's approach and framework was abstract and based on mathematics, Nakashima tried to extend the existent circuit theory of the time to deal with relay circuits, and was reluctant to accept the mathematical and abstract model, favoring a grounded approach.[6] Shannon's ideas broke new ground, with his abstract and modern approach dominating modern-day electrical engineering.[6]
The paper is commonly regarded as the most important master's thesis ever due to its insights and influence.[7][8][9][10] Pioneering computer scientistHerman Goldstine described Shannon's thesis as "surely ... one of the most important master's theses ever written ... It helped to change digital circuit design from an art to a science."[11] In 1985, psychologistHoward Gardner called his thesis "possibly the most important, and also the most famous, master's thesis of the century".[12] The paper won the1939 Alfred Noble Prize.
A version of the paper was published in the 1938 issue of theTransactions of the American Institute of Electrical Engineers.[13]
[Shannon] constructed a calculus based on a set of postulates which described basic switching ideas; e.g., an open circuit in series with an open circuit is an open circuit. Then he showed that his calculus was equivalent to certain elementary parts of the calculus of propositions, which in turn was derived from the algebra of logic developed by George Boole.