John McCarthy (September 4, 1927 – October 24, 2011) was an American computer scientist and cognitive scientist. McCarthy was one of the founders of the discipline of artificial intelligence. He coined the term “artificial intelligence” (AI), developed the Lisp programming language family, significantly influenced the design of the ALGOL programming language, popularized timesharing, and was very influential in the early development of AI.
McCarthy received many accolades and honours, such as the Turing Award for his contributions to the topic of AI, the United States National Medal of Science, and the Kyoto Prize.
John McCarthy is one of the “founding fathers” of artificial intelligence, together with Marvin Minsky, Allen Newell and Herbert A. Simon. McCarthy coined the term “artificial intelligence” in 1955, and organized the famous Dartmouth Conference in Summer 1956. This conference started AI as a field. (Marvin Minsky later joined McCarthy at MIT in 1959.)
In 1958, he proposed the advice taker, which inspired later work on question-answering and logic programming.
John McCarthy invented Lisp in the late 1950s. Based on the lambda calculus, Lisp soon became the programming language of choice for AI applications after its publication in 1960.
In 1958, McCarthy served on an ACM Ad hoc Committee on Languages that became part of the committee that designed ALGOL 60. In August 1959 he proposed the use of recursion and conditional expressions, which became part of ALGOL.
Around 1959, he invented so-called “garbage collection” methods to solve problems in Lisp.
He helped to motivate the creation of Project MAC at MIT when he worked there.
At Stanford University, he helped establish the Stanford AI Laboratory, for many years a friendly rival to Project MAC.
In 1961, he was perhaps the first to suggest publicly the idea of utility computing, in a speech given to celebrate MIT’s centennial: that computer time-sharing technology might result in a future in which computing power and even specific applications could be sold through the utility business model (like water or electricity). This idea of a computer or information utility was very popular during the late 1960s but faded by the mid-1990s. However, since 2000, the idea has resurfaced in new forms (see application service provider, grid computing, and cloud computing).
In 1966, McCarthy and his team at Stanford wrote a computer program used to play a series of chess games with counterparts in the Soviet Union; McCarthy’s team lost two games and drew two games (see Kotok-McCarthy).
From 1978 to 1986, McCarthy developed the circumscription method of non-monotonic reasoning.
McCarthy is also credited with developing an early form of time-sharing. His colleague Lester Earnest told the Los Angeles Times: “The Internet would not have happened nearly as soon as it did except for the fact that John initiated the development of time-sharing systems. We keep inventing new names for time-sharing. It came to be called servers…. Now we call it cloud computing. That is still just time-sharing. John started it.”
In 1982 he seems to have originated the idea of the “space fountain”, a type of tower extending into space and kept vertical by the outward force of a stream of pellets propelled from Earth along a sort of conveyor belt which returns the pellets to Earth (payloads would ride the conveyor belt upward).