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. 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.
Early life and education
John McCarthy was born in Boston, Massachusetts, on September 4, 1927, 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. His mother died in 1957.
Both parents were active members of the Communist Party during the 1930s, and they encouraged learning and critical thinking. Before he attended high school, he got interested in science by reading a translation of a Russian popular science book for children, called 100,000 Whys. John was fluent in the Russian language and made friends with Russian scientists during multiple trips to the Soviet Union but he 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. McCarthy was accepted into Caltech in 1944.
McCarthy showed an early aptitude for mathematics; during his teens he taught himself college mathematics 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 mathematics at Caltech. McCarthy 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.
McCarthy initially completed graduate studies at Caltech before moving to Princeton University. He received a PhD in mathematics from Princeton in 1951 after completing a doctoral dissertation, titled "Projection operators and partial differential equations", under the supervision of Donald C. Spencer.
Academic career
After short-term appointments at Princeton and Stanford University, McCarthy became an assistant professor at Dartmouth in 1955.
A year later, McCarthy 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.
In 1962, McCarthy 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.
Contributions in computer science
John McCarthy is one of the "founding fathers" of artificial intelligence, together with Alan Turing, Marvin Minsky, Allen Newell, and Herbert A. Simon. 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. (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.
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. Lisp soon became the programming language of choice for AI applications after its publication in 1960.