Alan Turing

Alan Mathison Turing was an English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. He made major contributions to the development of theoretical computer science and is often called the father of this field. Turing created the idea of a Turing machine, a theoretical model that helps us understand how computers work.

Born in London and raised in southern England, Turing studied at King's College, Cambridge, and later earned a doctorate from Princeton University. During World War II, he worked at Bletchley Park, Britain’s codebreaking centre. There, he led a team that helped break German ciphers, playing a key role in several important Allied victories.

After the war, Turing worked on designing early computers and also made important contributions to mathematical biology. Despite his many achievements, he faced difficult times due to the laws of his time regarding homosexuality. Turing died in 1954, but since then, he has been widely honoured. His portrait appears on the Bank of England £50 note, and many things are named after him, including an annual award for computing innovation.

Early life and education

Turing was born in Maida Vale, London, in 1912. His father worked for the government in India, but the family chose to live in Britain. Turing grew up in Britain and later attended several schools. He showed great interest in mathematics and science from a young age.

At Sherborne School, Turing met a friend named Christopher Morcom, who shared his love for science. Sadly, Morcom passed away from an illness, but this event inspired Turing to work even harder in his studies. Turing went on to study mathematics at King's College, Cambridge, where he earned top honors and began researching complex mathematical ideas. His work laid the foundation for modern computer science.

Career and research

When Turing returned to Cambridge, he attended lectures given in 1939 by Ludwig Wittgenstein about the foundations of mathematics. Turing and Wittgenstein argued and disagreed, with Turing defending formalism and Wittgenstein propounding his view that mathematics does not discover any absolute truths, but rather invents them.

During the Second World War, Turing was a leading participant in the breaking of German ciphers at Bletchley Park. From September 1938, Turing worked part-time with the Government Code and Cypher School, the British codebreaking organisation. He concentrated on cryptanalysis of the Enigma cipher machine used by Nazi Germany, together with Dilly Knox, a senior GC&CS codebreaker. Turing developed a broader solution using crib-based decryption for which he produced the functional specification of the bombe (an improvement on the Polish bomba kryptologiczna).

Turing had a reputation for eccentricity at Bletchley Park. He was known to his colleagues as "Prof" and his treatise on Enigma was known as the "Prof's Book". According to historian Ronald Lewin, Jack Good, a cryptanalyst who worked with Turing, said of his colleague: “In the first week of June each year he would get a bad attack of hay fever, and he would cycle to the office wearing a service gas mask to keep the pollen off. His bicycle had a fault: the chain would come off at regular intervals. Instead of having it mended he would count the number of times the pedals went round and would get off the bicycle in time to adjust the chain by hand.”

Due to the challenges answering questions concerning what an outcome would have been if a historical event did or did not occur (the realm of counterfactual history), it is hard to estimate the precise effect Ultra intelligence had on the war. However, official war historian Harry Hinsley estimated that this work shortened the war in Europe by more than two years. He added the caveat that this did not account for the use of the atomic bomb and other eventualities.

Between 1945 and 1947, Turing lived in Hampton, London, while he worked on the design of the ACE (Automatic Computing Engine) at the National Physical Laboratory (NPL). He presented a paper on 19 February 1946, which was the first detailed design of a stored-program computer. Von Neumann's incomplete First Draft of a Report on the EDVAC had predated Turing's paper, but it was much less detailed.

In 1948, Turing was appointed reader in the Mathematics Department at the University of Manchester. A year later, he became deputy director of the Computing Machine Laboratory, where he worked on software for one of the earliest stored-program computers—the Manchester Mark 1. Turing wrote the first version of the Programmer's Manual for this machine, and was elected to membership of the Manchester Literary and Philosophical Society. He continued to be paid consultancy fees by Ferranti until his death.

In 1948, Turing, working with his former undergraduate colleague, D.G. Champernowne, began writing a chess program for a computer that did not yet exist. By 1950, the program was completed and dubbed the Turochamp.

When Turing was 39 years old in 1951, he turned to mathematical biology, finally publishing his masterpiece "The Chemical Basis of Morphogenesis" in January 1952. He was interested in morphogenesis, the development of patterns and shapes in biological organisms. He suggested that a system of chemicals reacting with each other and diffusing across space, termed a reaction–diffusion system, could account for "the main phenomena of morphogenesis". A study conducted in 2023 confirmed Turing's mathematical model hypothesis. Presented by the American Physical Society, the experiment involved growing chia seeds in even layers within trays, later adjusting the available moisture. Researchers experimentally tweaked the factors which appear in the Turing equations, and, as a result, patterns resembling those seen in natural environments emerged. This is believed to be the first time that experiments with living vegetation have verified Turing's mathematical insight.

Personal life

Alan Turing had a fascinating personal life filled with unique experiences. In the 1940s, he hid silver bars to protect his savings from possible wartime loss, but later couldn’t remember where he buried them. He also invented a fun game called "round-the-house chess" where players alternate between chess moves and running around the house.

Turing proposed marriage to his colleague Joan Clarke, but they did not marry after he shared that he was homosexual. Later, he faced legal trouble when his relationship with another man became known. At the time, this was illegal in the United Kingdom, and he was convicted. As a result, he was barred from certain work and had to undergo medical treatment against his will. Despite these challenges, Turing continued his important work in mathematics and computing.

Death

Alan Turing was found dead in his home on 8 June 1954. The official investigation concluded that he had passed away the day before due to cyanide poisoning. An apple was found half-eaten near him, though it was never tested for cyanide.

Turing’s family and some experts have questioned whether his death was a suicide. Some believe it might have been an accident, perhaps from inhaling cyanide fumes during a small experiment in his home. Regardless, Turing’s remains were cremated, and his ashes were scattered in a garden.

Many who knew Turing did not think he showed signs of wanting to harm himself, and he had even made plans for tasks to complete after a holiday. Different ideas exist about what might have happened, but the exact circumstances remain uncertain.

Government apology and pardon

In 2009, a British programmer started a petition asking the government to apologize for how Alan Turing was treated because of his sexuality. The prime minister at the time, Gordon Brown, said sorry for the unfair way Turing was treated.

Later, in 2013, the British government gave Turing a pardon for an old law that made his actions a crime. This pardon was a way to recognize Turing's important work, especially during World War II, and to admit that the treatment he received was wrong. This pardon also helped many other men who were treated the same way.