“He was dressed in a somewhat untidy, brown sports jacket, and rather baggy grey trousers. He was not your typical Achilles figure, not a warrior king this man." (Captain Jerry Roberts, Bletchley Park).
Today (June 23) marks the centenary of Alan Turing's birth. Born in London, Alan Mathison Turing was, over his lifetime, many things: mathematician; logician; prime mover of the concepts of algorithms, computing machines, stored computer programmes, encrypted voice communications and artificial intelligence; wartime code-breaker; victim of prejudice, and more.
The theoretical process by which information can be stored in code and extracted from it by mechanical means was Turing's genius. In his 1936 essay On Computable Numbers, he proposed a universal computing machine – later known as a Turing Machine – a theoretical, algorithm-based model of computation itself. According to Turing, the 'computer' is not the device, but the human being who interprets the data it contains.
By his own definition, then, Turing was the 'computer' who, with thousands of unsung men and women at Bletchley Park, devised ways to break the German ciphers created by that country's Enigma machines during the Second World War.
His colleague at Bletchley Park, Captain Jerry Roberts, had this to say about the man to the BBC: "The extraordinary thing is that this quiet man was probably the most important man of his time, except possibly Churchill. Turing did not look like a superstar, he was a very modest man, but Turing was the genius who broke Naval Enigma.”
Turing's development of the Bombe, with Gordon Welchman, Harold Keen and others, was crucial to Britain's survival and the Allied victory: knowing the movements of German U-boats prevented the further loss of thousands and ships and supplies which, until then, had been crippling the country.
Ironically, the secrecy surrounding Turing's wartime activities helped bury his memory for years, and may have prevented some of his work's commercial exploitation in the UK.
Immediately after the war, Turing designed the Automatic Computing Engine (ACE), one of the earliest stored computer program concepts. He then went on to become deputy director of the Computing Laboratory at Manchester University, where he became interested in artificial intelligence and theoretical mathematics – an interest he extended into what were, for the time, esoteric studies in chemistry and biology.
Turing is now celebrated as a very British hero: the man born at the right time for the world but the wrong time for himself; the man punished by the country he helped save; the man whose real-world vision born of imagination, mathematics, science and research was swept aside by the marketers and bankers of modern British industry; the man who held the white heat of technology in his hands two decades before Harold Wilson uttered the words; the proud gay man in a world of secrets, lies and hypocrisy; the modest man who helped save millions of lives only to lose his own.
Convicted of what was then considered gross indecency – a sexual relationship with another man – Turing faced either prison or chemical castration via the ingestion of synthetic oestrogen. He chose the latter, and it is generally believed that this helped drive him to suicide, although his death may have been accidental.
Did he eat a poisoned apple, or drink a bottle of cyanide and then leave a half-eaten apple – the forbidden fruit – as a last, bitter joke? Or did he leave it to suggest that his death might have been accidental, to protect the feelings of those who loved him? Or was his death, indeed, just a tragic mistake, inhaling cyanide fumes from a bottle left open, or spilled, in his room?
We will never know for certain: the apple (which did not inspire Apple's logo, as many believe – although Steve Jobs wished that it had) was never tested for the cyanide that killed Turing in 1954.
Turing was a more modern man than his legend perhaps suggests: not ashamed of his sexuality, but punished for it all the more as a result; not a loner or a dreamer, but a real-world thinker, a good-humoured pragmatist and researcher; not just a code-breaker but a coder – a man who was one of the fathers of modern computing, of binary systems, and of intelligent machines. What more might he have achieved had he lived?
Every IT professional who has ever laboured unappreciated in the backrooms of British enterprise should treasure him. Every technologist and potential world-beater struggling to raise investment for their dream should treasure him, too.
Turing was important because he was the genuine article: skilled, committed, touched by genius, hard-working, modest, true to himself, and determined to throw everything he had into making his ideas work. Today, we all stand on the shoulders of such giants.
So everyone in our industry, and everyone in this country, owes Alan Turing their gratitude, and the way he was treated in the run-up to his death (like many other gay men of the time) is a national shame.
This government wants to support British innovators and technologists, and it has also made a commitment to support full gay equality. The fourth plinth in Trafalgar Square would be a fitting site for a permanent memorial to Turing in the heart of our capital city.
A statue there would be a strong statement in support of both communities – who share many people, of course – and a national acknowledgement of Turing's extraordinary achievements and contributions.
Let's work together to make that happen: please support the idea on this site, on Twitter, on Facebook, and wherever you share opinions or hold conversations.
"We can only see a short distance ahead, but we can see plenty there that needs to be done." (Alan Turing)
• Since this article was published, two separate e-petitions have been created by readers. If you agree with the idea to create a permanent memorial to Alan Turing on the fourth plinth in Trafalgar Square, please sign them. http://epetitions.direct.gov.uk/petitions/29811
• At the time of writing, a separate e-petition to grant Alan Turing a pardon has received over 35,000 signatures.