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Mathematician Alan Turing a Great Mind of the 20th Century

Sir Winston Churchill said Alan Turing’s breaking of German codes for secret messages shortened the Second World War by two years. Computer scientists credit Turing with formulating the philosophical principles that power every computer and smartphone today. Researchers in artificial intelligence, meanwhile, label him the founder of their field. Chemists say Turning predicted the existence of reactions that change colour in a periodic fashion before these had ever been observed. Biologists say his theories of “morphogenesis,” the biological process that causes an organism to develop its shape, explain phenomena such as the stripes of a zebra by predicting the effects of the diffusion of two different chemical signals, one activating and one deactivating growth. The British government said Turing was a homosexual who needed to be chemically castrated. Police said his death was the result of suicide, probably by consuming a cyanide-laced apple. Steve Jobs said he wished the Apple logo had been devised in Turing’s honour, reflecting how everyone says that he was a computational genius. Few, however, know that Turing’s first scientific infatuation was with chemistry.

In 1924, at the age of 12, young Turing got his hands on Natural Wonders Every Child Should Know, by Edwin Brewster. He was totally taken by the book’s discussion of plants containing chemicals like strychnine and atropine, capable of killing or curing. He was also intrigued by how “carbon dioxide becomes in the blood ordinary cooking soda” and how “the blood carries the soda to the lungs where it changes to carbon dioxide again, exactly as it does when, as cooking soda you add it to flour and use it to raise cake.” He was overjoyed when, for Christmas, he was given a set of chemicals, crucibles and test tubes. He immediately put it to use to extract minute quantities of iodine from seaweed.

Knowing of his interest in iodine, Christopher Marcom, an older student with whom Alan had developed a friendship that bordered on infatuation, told him of an experiment involving solutions of iodates and sulphites that, when mixed, resulted in the formation of iodine. When starch was present in the solution, the formation of iodine was signalled by the sudden appearance of a deep blue colour, characteristic of a starch-iodine complex. Turing was intrigued by the concentration-dependent time delay in the appearance of the blue colour and was convinced that the proper use of mathematics could predict the results. Indeed, it was this little problem that may have launched him into an area where his genius would be prominently displayed, namely mathematics and computer logic.

After receiving an undergraduate degree in mathematics from the University of Cambridge, Turing obtained a PhD from Princeton University, where he developed a strong interest in cryptography, the science of writing messages in secret code. When Britain declared war on Germany in 1939, Turing was immediately offered a position as a code breaker. The Germans had developed the Enigma, a machine that used a combination of mechanical and electrical effects to transform a message typed on a keyboard into what seemed like an undecipherable jumble of letters until the code was run through another Enigma unit. With colleague Gordon Welchman, Turing developed early computers, called “bombes,” that were capable of breaking the code. The Allies now had the ability to decode messages sent to German U-boats about planned attacks on supply ships carrying supplies vital for the war effort.

After the war, Turing worked at the National Physical Laboratory designing computers and then in 1948 joined the mathematics department at the University of Manchester where, in 1950, he launched the concept of artificial intelligence with his paper that asked the question “Can Machines Think?” In it he also introduced the Turing Test, aimed at determining whether a human can detect if he is communicating via a keyboard with another human or with a machine. The emphasis is on how closely the answers to questions posed resemble typical human answers, not on whether the answers are correct. If at least 30 per cent of judges believe that they are talking to a human when they are actually speaking with a computer, the computer is said to have passed the Turing Test.

Now, for the first time ever, Eugene Goostman, which is the name of a computer program created by Vladimir Veselov of Russia and Eugene Demchenko of Ukraine, has managed to fool the required number of judges into believing that they were actually speaking with a 13-year-old Ukrainian boy. The historic event took place at the renowned Royal Society in London, poignantly on the 60th anniversary of Turing’s death.

The death is still mired in mystery. In 1952, Turing’s house was burgled and suspicion fell on a young male guest who had been staying with him. During the investigation, Turing’s homosexuality was revealed and since this was a criminal offence at the time, he was charged with “gross indecency.” The option, the judge explained, was either jail time or “chemical castration.”

Back in the 1940s, there had been speculation that homosexuality was caused by low levels of testosterone, the male sex hormone. But if anything, treatment with testosterone increased the sex drive. Researchers then turned to female hormones, hoping to counter the effects of testosterone and soon discovered that these did indeed reduce libido. To avoid prison, Turing agreed to undergo a year-long treatment with the synthetic estrogen diethylstilbestrol (DES), a regimen that he apparently managed with no significant problems, carrying on as usual with his work.

We can only guess at what this brilliant mind could have accomplished had it not been put out of commission by cyanide in 1954. The official verdict was suicide, with speculation that a half-eaten apple found at the bedside had been used to deliver the poison. The apple was never tested and Turing was in fact known to favour an apple at bedtime. Given that he had shown no signs of depression and had planned meetings for the next week, some contend that Turing accidentally poisoned himself with some of the cyanide he was using in gold-plating experiments in his small apartment. And then there are the conspiracy theorists who maintain he was assassinated because authorities were worried that homosexuals who possessed sensitive information were a security threat to Britain.

In 2013, Queen Elizabeth II signed an official pardon for Turing’s conviction for gross indecency. Indeed, the only indecency had been the appalling way in which one of the greatest minds of the 20th century was treated.

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