John McCarthy (computer scientist)

John McCarthy (September 4, 1927 – October 24, 2011) was an American computer scientist and cognitive scientist.

He was one of the founders of the discipline of artificial intelligence.

He co-authored the document that coined the term "artificial intelligence" (AI), developed the programming language family Lisp, significantly influenced the design of the language ALGOL, popularized time-sharing, and invented garbage collection.

McCarthy spent most of his career at Stanford University.

Both parents were active members of the Communist Party during the 1930s, and they encouraged learning and critical thinking.

Before he attended high school, McCarthy became interested in science by reading a translation of 100,000 Whys, a Russian popular science book for children.

He was fluent in the Russian language and made friends with Russian scientists during multiple trips to the Soviet Union, but distanced himself after making visits to the Soviet Bloc, which led to him becoming a conservative Republican.

McCarthy graduated from Belmont High School two years early and was accepted into Caltech in 1944.

He showed an early aptitude for mathematics; during his teens, he taught himself college math by studying the textbooks used at the nearby California Institute of Technology (Caltech).

As a result, he was able to skip the first two years of math at Caltech.

He was suspended from Caltech for failure to attend physical education courses.

He then served in the US Army and was readmitted, receiving a BS in mathematics in 1948.

It was at Caltech that he attended a lecture by John von Neumann that inspired his future endeavors.

In the late 1950s, McCarthy discovered that primitive recursive functions could be extended to compute with symbolic expressions, producing the Lisp programming language.

That functional programming seminal paper, also introduced the lambda notation borrowed from the syntax of lambda calculus in which later dialects like Scheme based its semantics.

McCarthy completed his graduate studies at Caltech before moving to Princeton University, where he received a PhD in mathematics in 1951 with his dissertation "Projection operators and partial differential equations", under the supervision of Donald C. Spencer.

After short-term appointments at Princeton and Stanford University, McCarthy became an assistant professor at Dartmouth in 1955.

A year later, he moved to MIT as a research fellow in the autumn of 1956.

By the end of his years at MIT he was already affectionately referred to as "Uncle John" by his students.

McCarthy, Minsky, Nathaniel Rochester and Claude E. Shannon coined the term "artificial intelligence" in a proposal that they wrote for the famous Dartmouth conference in Summer 1956.

This conference started AI as a field.

His mother died in 1957.

In 1958, he proposed the advice taker, which inspired later work on question-answering and logic programming.

In 1958, McCarthy served on an Association for Computing Machinery ad hoc committee on Languages that became part of the committee that designed ALGOL 60.

(Minsky later joined McCarthy at MIT in 1959.)

In August 1959 he proposed the use of recursion and conditional expressions, which became part of ALGOL.

He then became involved with developing international standards in programming and informatics, as a member of the International Federation for Information Processing (IFIP) IFIP Working Group 2.1 on Algorithmic Languages and Calculi, which specified, maintains, and supports ALGOL 60 and ALGOL 68.

Around 1959, he invented so-called "garbage collection" methods, a kind of automatic memory management, to solve problems in Lisp.

He helped to motivate the creation of Project MAC at MIT when he worked there, and at Stanford University, he helped establish the Stanford AI Laboratory, for many years a friendly rival to Project MAC.

McCarthy was instrumental in the creation of three of the very earliest time-sharing systems (Compatible Time-Sharing System, BBN Time-Sharing System, and Dartmouth Time Sharing System).

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."

Lisp soon became the programming language of choice for AI applications after its publication in 1960.

In 1962, he became a full professor at Stanford, where he remained until his retirement in 2000.

McCarthy championed mathematics such as lambda calculus and invented logics for achieving common sense in artificial intelligence.

John McCarthy is one of the "founding fathers" of artificial intelligence, together with Alan Turing, Marvin Minsky, Allen Newell, and Herbert A. Simon.

He received many accolades and honors, such as the 1971 Turing Award for his contributions to the topic of AI, the United States National Medal of Science, and the Kyoto Prize.

McCarthy was born in Boston, Massachusetts to an Irish immigrant father and a Lithuanian Jewish immigrant mother, John Patrick and Ida (Glatt) McCarthy.

The family was obliged to relocate frequently during the Great Depression, until McCarthy's father found work as an organizer for the Amalgamated Clothing Workers in Los Angeles, California.

His father came from Cromane, a small fishing village in County Kerry, Ireland.