The man who believed machines could think

    In 1952, the mathematician Alan Turing called the police to report that his house in Manchester had been burgled. The thieves did not take much, so it first seemed that the official statement of the burglary would be no more than a formality. It was not very likely that the burglars would be discovered and the stolen items and money retrieved. It soon turned out that the mathematician would have been much better off if he had not contacted the police. After a brief questioning on the possible background of the burglary, Turing was suddenly transformed from the victim into the criminal.

    A moral crime

    Turing confessed to the officers that he had been seeing a nineteen-year-old youth called Arnold Murray who he had met shortly before the incident. Arnold had spent a couple of nights at his place and also borrowed some money, so it was very possible that he had something to do with the burglary. Now, the police were no longer interested in the details of the theft, but in another offence which Turing was careless enough to confess.

    At the time, homosexuality was still considered to be a crime in England and the police quickly grasped the true nature of the relationship between the two men. Turing was summoned to appear in court on the same charges (“gross indecency”) for which Oscar Wilde had been sentenced to two years in prison half a century earlier. During the trial Turing never denied his “crime”, and was – according to the law from 1885 which was originally created to protect women – sentenced to choose between imprisonment or compulsory treatment of homosexuality. He opted for a course of treatment which was more like torture and did nothing to change his sexual orientation.

    In order to avoid prison he had to, in accordance with the sentence of the court, undergo a one-year therapy with the female sex hormone estrogen which was supposed to eradicate his lust for men. For a year, he received regular shots of estrogen which caused him to gain weight and visibly develop breasts. In reality, the hormone therapy was a sort of chemical castration as it did not “heal” his homosexuality, the worst part of it being that it also affected his ability to think and concentrate. Because of this completely absurd law, the British legal apparatus systematically destroyed one of the greatest minds of England. At the time Alan Turing was just over 40 years’ old.

    100 km bicycle ride to school

    In the beginning of the twentieth century Turing’s father served as a British colonial officer in India. Because his mother believed the Indian environment to be inappropriate for the education of her two sons, Alan and his older brother John spent their youth in different English institutions for children and, later, in boarding schools. In 1926 when Alan was 14 years old, he was accepted by the renowned Sherborne School, but almost came in late for his first day of class. England was just then in the middle of a general strike during which public transportation was cancelled, so young Alan had to set off on a hundred-kilometer journey from his home to the school on a bicycle. His unusual cycling exploit was even mentioned in the newspapers.

    He continued to lead an athletic life, especially as a long distance runner. He often used to run to science conferences, sometimes even beating his colleagues who preferred less demanding means of transportation. He would actually have been selected for the 1948 British Olympic team had it not been for an unfortunate injury.

    Alan discovered his homosexuality early, during his teen years, when he was strongly attached to one of his classmates who suddenly died after complications in tuberculosis treatment. The loss of this good friend in his youth also dealt a blow to his religious faith. He became an atheist and firmly convinced that everything had to have a factual explanation, even the processes which lead to thoughts in the brain.

    After failing twice to win a scholarship to Trinity College at the University of Cambridge, he decided to enroll into King’s College where, among others, John Maynard Keynes and E. M. Forster lectured. After writing an excellent doctoral thesis, he was invited to remain at the university as a teacher and a researcher. If it had not been for the Second World War, he probably would have continued his academic career for a long time, but his country needed him for another, highly important national security project.

    How to decipher the Enigma?

    On obtaining his doctorate Turing left for the United States and spent a couple of years at Princeton University, but returned at the outbreak of war to join the secret decryption centre at Bletchley Park, situated between Cambridge and Oxford. This was where the British gathered mathematicians, chess masters, Egyptologists and all others who might be in any way capable of deciphering intercepted German military messages.

    It was particularly difficult to decipher the enemy’s coded messages because the German Army used a special mechanical device called the Enigma which looked like a kind of typewriter. With the aid of this device they could encode their messages so efficiently that they were certain that, without the decryption key, which they changed every day, nobody would be able to read them.

    Soon after his arrival to Bletchley Park, Turing and his colleagues developed an electro-mechanic machine which enabled them to break the German code each day and read the messages of the hostile army. It was especially important that they also succeeded in breaking the additionally reinforced code system which had been used by German submarines in the North Atlantic. Turing’s ideas, in which he combined all of his previous research in the foundations of logic and mathematics with the notion of a machine that could do great amounts of work quickly and efficiently, were of key importance in the successful deciphering of the Enigma.

    Like many great scholars, Turing was a peculiar character himself. He rode a bicycle to his post in Bletchley Park wearing a gas mask which he believed would protect him from pollen. In the tearoom he chained his cup to the radiator, so that nobody would take it.

    Until the British removed the label classified from the documents containing information about their great wartime project of decoding German military messages, Alan Turing was best known to the public for his achievements in the fields of mathematical logic and the theoretical basics of artificial intelligence. It was only after this revelation that it became clear how important his influence had been on the course of the the war.

    The poisoned apple

    After the war, Turing returned to Cambridge hoping to find some peace in his academic work. He joined a group that was trying to build a working prototype for a computer, but soon discovered that in postwar England many bureaucratic restrictions had been restored, making work more difficult. During the war, German messages had to be deciphered as quickly as possible by whatever means, so scholars were given a free rein in choosing their methods of work. All that mattered were results. After the war, old restraints were reinforced. In addition, Turing did not really feel at home in Cambridge, so he accepted a position at the University of Manchester where researchers were also attempting to construct a computer.

    During his stay in Manchester he published some more influential articles, among which was the well-known article on artificial intelligence in which he presented his famous test designed to determine if a computer could really think. According to the Turing test, as it was later called, a machine can be said to be capable of thought when, on the basis of its answers, no one can tell whether it is a human or a machine that is answering the questions.

    On the 8th of June 1954 his cleaning lady found him dead in his bed. On his night table was a bitten apple poisoned with cyanide. Although there was no death note to be found it is almost certain that he had committed suicide. His mother firmly believed that her son’s death was the result of his carelessness after a chemistry experiment, but, as one of his biographers argued, it is more likely that Turing took his life in a way that would allow his mother to give the act an interpretation she could live with.

    Many years after Turing’s death, a rumor spread that the bitten apple, which is today the trademark of the Apple company, was in fact a tribute to the tragic life story of “the father” of computers. This has never been officially confirmed.