Alan Turing: The Mathematician Who Shortened a War
A shy Cambridge scholar built a machine of pure logic to defeat an unbreakable German cipher — and in doing so, quietly invented the idea of the computer.
In 1912, in a house in Maida Vale, London, Alan Mathison Turing was born to Julius Mathison Turing and Ethel Sara Turing (née Stoney), a couple who had returned from British India so their son could be raised in England. From an early age his teachers noticed something unusual: the headmistress of his first school remarked that she had known clever boys and hardworking boys, but Alan was a genius. At Sherborne School he began solving advanced mathematics problems before he had even learned calculus and integration in his lessons, and at sixteen he independently worked through Einstein's critique of Newton's laws of motion.
Turing went on to King's College, Cambridge, graduating with a distinguished degree, and in 1938 earned a doctorate from Princeton University. On 28 May 1936 he submitted his landmark paper, known in English as 'On Computable Numbers, with an Application to the Entscheidungsproblem,' introducing what became known as the Turing machine — a formal model showing how any problem expressible as an algorithm could, in principle, be solved by such a device. It was an abstract idea, but it laid the conceptual foundation for every computer that followed.
When the Second World War began, Turing joined the Government Code and Cypher School at Bletchley Park, Britain's codebreaking centre. He led Hut 8, the section tasked with breaking German naval ciphers produced by the Enigma machine. Building on the pre-war Polish bomba method, Turing devised improved techniques and machines for finding Enigma settings, dramatically speeding up the decryption process.
The intelligence gathered under the codename Ultra proved decisive in the Battle of the Atlantic and other major engagements, helping the Allies track and counter German naval movements. Because his work fell under the Official Secrets Act, Turing received little public recognition during his lifetime for what may have been one of the most consequential contributions of the war.
After 1945, Turing turned to building machines rather than just theorizing about them. At the National Physical Laboratory he designed the Automatic Computing Engine, one of the earliest designs for a stored-program computer. In 1948 he joined Max Newman's Computing Machine Laboratory at the University of Manchester, contributing to the development of early Manchester computers. His curiosity then turned toward biology: he wrote about the chemical basis of morphogenesis and predicted oscillating chemical reactions that would not be observed experimentally until the 1960s.
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