Alan Turing was a brilliant mathematician, computer scientist and an expert in biology and artificial intelligence. He was also a very good cryptologist and played a large part in helping to win the Second World War. But he also led a troubled life and was hounded by the authorities at the time.
He was born on the 23rd June 1912 in Maida Vale, London. His talent was noticed early and it was said that he understood Einstein’s Theory of Relativity by the age of sixteen. He went to King’s College, Cambridge and got a first in mathematics. At the same time he began studying the new science of computers and published a paper on the building of a calculating machine. This paper is still taught to students today.
But it was during the Second World War that Turing was able to really make his mark. The Germans had a code-making machine called Enigma and the naval version of it was the most difficult to crack. Turing, along with a team of code-breakers working out of Bletchley Park were able to break the code which gave the Allies a huge advantage. During this time he became engaged to a fellow cryptanalyst by the name of Joan Clarke. But it did not last as Turing admitted to her that he was gay.
After the war he worked at the National Physical Laboratory working on the Automatic Computing Engine or ACE. In the 1950s he worked on artificial intelligence and came up with the Turing Test which is still in use today. It involves a computer or human attempting to answer a set of questions posed by another human. If the computer fools the questioner, it wins.
At this time being gay was a crime. Turing had managed up to this point to keep it a secret. But in 1952 Turing had a relationship with another man. There was a burglary at Turing’s home and during the police investigation his gay relationship came to light. He was charged and found guilty of gross indecency and given hormonal treatment. But it also meant that he lost his high security clearance. He was able to keep his academic postings but was banned from the USA.
Turing was found dead at his home on the 8th June 1954. The post mortem showed he had died of cyanide poisoning. There was a half-eaten apple close by but it was never tested. However, the pathologist deduced that the cyanide was inhaled rather than swallowed and Turing did have cyanide in his house as part of an experiment. Some conspiracy theorists believe he was murdered by the authorities because he knew too much, but there is no evidence for this. But what we can be sure of was that he was one of the greatest mathematical minds of the twentieth century.