Father of artificial intelligence saw personal computers as toys

COMPUTER SCIENTIST

4-9-1927 24-10-2011

JOHN McCarthy, who was often described as the father of "artificial intelligence" (AI), a branch of computer science founded on the notion that human intelligence can be simulated by machines, has died of heart disease at his home in Stanford, California. He was 84.

McCarthy, who coined the term in 1956, defined it as "the science and engineering of making intelligent machines" and created the Lisp computer language to help researchers in the AI field.

He maintained that there were aspects of the human mind that could be described precisely enough to be replicated: "The speeds and memory capacities of present computers may be insufficient to simulate many of the higher functions of the human brain," he wrote in 1955, "but the major obstacle is not lack of machine capacity but our inability to write programs taking full advantage of what we have."

McCarthy went on to create AI laboratories at the Massachusetts Institute of Technology and later at Stanford University, where he became the laboratory's director in 1965.

During the 1960s, he developed the concept of computer time-sharing, which allows several people to use a single, central, computer at the same time. If this approach were adopted, he claimed in 1961, "computing may some day be organised as a public utility".

His concept of time-sharing made possible the development of so-called "cloud computing" (the delivery of computing as a service rather than a product). Meanwhile, his Lisp programming language, which he invented in 1958, underpinned the development of voice recognition technology.

McCarthy's laboratory at Stanford developed systems that mimic human skills such as vision, hearing and the movement of limbs as well as early versions of a self-driving car. He also worked on an early chess-playing program.

The concept of AI inspired numerous books and sci-fi films, notably Stanley Kubrick's dystopian 2001: A Space Odyssey (1968).

Meanwhile, he applied himself to addressing theoretical issues about the nature of human and robotic decision-making and the ethics of creating artificial beings. He also wrote a sci-fi story, The Robot and the Baby, to "illustrate my opinions about what household robots should be like". The robot in the story decides to simulate love for a human baby.

McCarthy was born in Boston to an Irish father and Lithuanian mother. The family lost their home during the Great Depression and moved to Los Angeles, where his father worked as a union organiser he also developed a hydraulic orange-juice squeezer. His mother had been active in the women's suffrage movement and both parents were active members of the Communist Party.

McCarthy taught himself mathematics as a teenager and when he arrived at the California Institute of Technology aged 16, he was so advanced that he was assigned to a graduate course.

In 1948, a symposium at Caltech on "Cerebral Mechanisms in Behaviour", which included papers on automata and the brain and intelligence, sparked his interest in developing machines that could think like people.

McCarthy received a doctorate in mathematics from Princeton University in 1951 and was immediately appointed to a chair in the subject.

It was at Princeton that he proposed the programming language Lisp as a way to process more sophisticated mathematical concepts than Fortran, which had been the dominant programming medium until then.

McCarthy joined the Stanford faculty in 1962 after short appointments at Princeton, Dartmouth and MIT, remaining there until he officially retired in 2000.

During the 1970s, he presented a paper on buying and selling by computer, prophesying what has become known as e-commerce. He also invited a local computer hobby group, the Homebrew Computer Club, to meet at the Stanford laboratory. Its members included Steve Jobs and Steven Wozniak, who would go on to found Apple.

However, his own interest in developing time-sharing systems led him to underestimate the potential of personal computers. When the first PCs emerged in the 1970s, he dismissed them as "toys".

McCarthy continued to work as an emeritus professor at Stanford after his official retirement, and at the time of his death was working on a new computer language called Elephant.

McCarthy won the Turing Award from the Association for Computing Machinery in 1972, the Kyoto Prize in 1988, and the National Medal of Science in 1990. Despite his disappointment with AI, McCarthy remained confident of the power of mathematics: "He who refuses to do arithmetic is doomed to talk nonsense," he wrote in 1995.

McCarthy is survived by his third wife, Carolyn, their son, and by two daughters of his first marriage.