Throughout his life he was misunderstood, ignored, even ridiculed. His manners were gross; his appearance verged on the disreputable. In attempting to explain to colleagues the visionary ideas crammed into his giant intellect, he often relapsed into almost incomprehensible stammering. He was mysterious and contradictory, but in a short life span – only 42 years – his discoveries and inventions saved thousands of lives. Yet, he was unknown in life and almost anonymous in death. Only in recent years have historians finally accorded Alan Turing the status he deserves. In a special edition about the most important people and events of the Twentieth Century, TIME named Alan Turing as one of the 100 most important people of the century. The magazine praised his seminal work on computing, calling it “one of the key crossroads in the advancement of science and technology.”
Alan Turing’s influence will appear again in other articles on this site, beginning with this piece. It appeared in in September 2000 in a special edition of British Heritage magazine. Learn how this eccentric oddity changed the world – and did it almost entirely in secret.
Alan Turing – ENIGMA
The man who broke the “unbreakable” code was at home in his world of figures and computations, but seldom elsewhere.
Peculiar practices clung to Alan Turing like layers of moor fog. To his Bletchley Park colleagues, he was “the Prof,” often seen distractedly hurrying to or from the mansion and Hut 8, the section struggling to break the secret German U-boat code. To his neighbors in Shenley village, he was the odd one on the bicycle wearing a gas mask, the best thing for relief of chronic allergies, he believed.
He was iconoclastic contradictory, and eminently mysterious. Few would know of his achievements during his lifetime, but in the last years of the 20th century, the fundamental logic of his “Universal Turing Machine” – central to the science of computing – would finally confer on Turing the long-delayed recognition as “intellectual father” of the modern computer.
His mind was occupied with constant calculation. In determining that a loose bicycle chain would come off after 14 turns, he would stop to adjust the chain after each 13 revolutions. To him, this was merely a practical application of the same logical deduction needed to solve the Enigma riddle. He knew that the chain of inferences necessary for breaking Enigma ciphers led to either a contradiction (you were wrong and moved to the next position on the rotor) or a confirmation, as the likely letters became words and then a solution. Scientists used this same approach to determine the probability of any assumption – observe and conclude.
Turing had few friends, stammering speech, and unrefined manners. To say that he was merely “unkempt” was like saying that ‘Shakespeare was only “talented.” Mrs. Turing regularly wrote her son reminders to purchase items of basic apparel. “Buy at least one suit a year,” she cautioned. He held up his trousers with string and often wore a pajama top under his sport coat. Fearing that Britain could lose the war, he converted his funds into two silver ingots, buried them, and then forgot where they were. The more discerning of his Hut 8 conferees saw deeper personality layers of subtlety and erudition, although it was difficult for anyone to understand why he needed to attach his tea mug to a radiator pipe with a combination lock. Oft-repeated anecdotes about the Prof’s peccadilloes no doubt leavened otherwise sober conferences in the mansion. His parents had learned to accept their son’s eccentricities, concluding that his genius surpassed his oddness. Years later his mother recalled, “at twelve and a half, he was trying to learn organic chemistry all by himself.”
Alan Mathison Turing was born in Warrington Lodge, a nursing home in Paddington, London, on 23rd June 1912, the younger of two sons of Julius Turing and Ethel Sara Stoney. His English parents had met and wed in India. The senior Turing was in the Madras civil service, and Ethel was the daughter of the Madras railroad’s chief engineer. Until Julius’ retirement in 1926, when the couple returned to Britain, both Alan and his brother John were raised in a series of English foster homes. Disconnected from family and with few friends, Alan was unhappy as he began his adolescent years at Sherborne, a noted boys prep school. His mother knew from the first letter that, “he was hopelessly miserable.” Alan became a marathon runner and was finally given recognition by classmates and the Sherborne faculty when, to further prove the earth’s rotation, he built a replica of the Foucault Pendulum in the dormitory stairwell.
Awarded a major scholarship to Kings College, Cambridge in 1931, Alan read theoretical mathematics and was elected a Fellow in 1935. Only a year later he presented his first paper to the London Mathematical Society. On Computable Numbers proved the theory that some mathematical problems could never be solved using fixed, formal processes. Instead of substantiating evidence with a mathematical formula, however, Turing proved the theory by proposing an abstract “universal computing machine.” The unconventional and original “machine” had a head and moveable paper tape divided into frames, such as on a roll of film. The head acted as a scanner and could be pre-programmed with instructions. Each frame had a symbol, such as a 0 or 1, or could be left blank. Each square could be separately read, and the paper could be moved left or right and the symbols changed, rewritten, or erased.
With its function of program input, output, memory, and the implication of information processing, Turing’s visionary automatic problem-solving theory defined in every way (except by name) the operating system of a modern digital computer. At age 24 he had unintentionally advanced the principles of the “analytical engine” proposed by Charles Babbage in 1833.
After two years in America during which he earned a Ph.D. from Princeton, he retuned to Cambridge in July 1938, as war butts gathered. On September 4, 1939, the day after the declaration of war by Prime Minister Chamberlain, Alan reported for duty at Bletchley Park. It was the darkest time for Britain and for British intelligence. Not a single Enigma-coded message had been solved in almost 10 months. The U-boat menace had grown from one submarine in 1935 to 57 at the outbreak of war. In the first nine months of the conflict U-boats would sink 701 Allied ships with 2.3 million tons of vital cargo, most of it from America. Britain could not long survive if the sea-lanes were not made safer.
The German military transmitted thousands of Enigma-coded messages every day. At least 100,000 of the chunky, portable typewriter-like machines had been manufactured by 1942. Every ship, U-boat, air base, and every unit in the German armed forces possessed at least one of the devilish devices, but with Turing’s arrival at Bletchley, the Ultra code-breakers had an immediate advantage: During the initial critical assault on the Enigma variations, Alan Turing was the only mathematician at Bletchley.
Assisted by Gordon Welchman, Alan used existing mathematical principles to devise a mechanized approach to seeking out the “probable words” common to all secret messages. The Bletchley Park “bombes” (noisy, crude, but effective electro-mechanical code-breaking machines) – went from decoding a trickle of 50 Enigma messages a week in 1940 to 3,000 per day in 1943.
After the war, Alan Turing slipped back into the academic obscurity from which he had emerged. In September 1945, he accepted a position at the National Physical Laboratory in London to design an electronic computer partially based on his own Universal Turing Machine. He resumed the King’s College fellowship in 1947, began research into computer development in 1948 at Manchester University, and in 1950 developed the “Turing Test,” the game that would forever link him with the origins of artificial intelligence. At the dawn of the computer age, the mysterious misfit had become accepted.
Then, on 11th February, 1952, in Manchester, he was arrested for “gross indecency with a nineteen year old male person.” The same draconian 1885 ordinance used to imprison Oscar Wilde in 1895, had brought Alan Turing’s long-closeted private life into public view.
In lieu of two years in prison, he agreed to a course of “organo-theraphy” – chemical castration with female hormones. He wrote to a friend: “It is supposed to reduce sexual urges whilst it goes on, but one is supposed to return to normal when it is over. I hope they’re right.” The disintegration of his life was almost complete, with his government security clearance removed and his reputation in tatters.
On 7th June 1954, the housekeeper found him dead at home in Wilmslow, near Manchester. A partially eaten cyanide-laced apple lay next to the bed. Loyal to the end, his mother insisted that it was an accident. The national press took little notice. No monuments were erected; no plaques to his memory were commissioned. Misunderstood in life and neglected in death, Turing left a legacy that included the Ultra secret, unfinished works on plant life, artificial intelligence, physics, and computer theory. He was only 42 when he died.