Trigger warning: mentions of suicide and homophobia

Computers. Laptops. Smartphones. Tablets. It’s difficult to imagine a day in modern life without any of these devices. Yet none of them would exist without Alan Turing, the British mathematician widely regarded as the father of computer science and artificial intelligence. If his name rings a bell, it’s probably via The Imitation Game – the recent biopic starring Benedict Cumberbatch that focuses on Turing’s code-breaking efforts during WWII.

So who was he? To give a starting image: there’s a sketch of Turing as a kid that, hilariously enough, shows him examining daisies while he’s supposed to playing hockey in the field with the other children. At 16, Turing closely befriended another boy named Christopher Morcum. They bonded over math and science, sat next to each other in every class, passed notes, studied together. At some point, Turing fell in unrequited love. So, as you can imagine, Morcum’s death by tuberculosis two years later had a profound effect on Turing. The grief and confusion caused by the event dismantled his religious faith, replacing it with a secular worldview.

The following year, Turing headed to Cambridge to study mathematics. Here he first conceived of the Universal Turing Machine – a hypothetical representation of a computer that could solve any computable problem. It comprised of three parts: an infinitely long tape, something that read and wrote ones and zeroes on the tape, and instructions about which parts to write over or erase. These elements made up memory storage (the tape) and a modifiable, internal program (the instructions). This was a groundbreaking leap. Prior to this, the best computer was Babbage’s Analytical Engine, which stored programs externally as punch-hole cards to be interpreted by mechanical components. Storing programs in the same form as the data was unheard of. Turing’s theoretical conceptualisations, perfected by 1945, laid the foundations for the modern digital computer.

Turing was also fascinated by the philosophical implications of all this. Until the 1940s, the term “computer” meant a person who carried out calculations. Now here was the inkling of a logical machine, trying to imitate the human mind. Turing believed that, in time, computers would be capable of intelligent thought, indistinguishable from humans’. He even felt empathy with machines, imagining them as victims of prejudice in the future.

It’s saddening, then, that homophobic prejudice led to Turing’s own persecution. In the 1950s, homosexual relations were illegal in Britain. Turing was never ashamed of being gay, and the fact was well-known among his friends and colleagues. But in 1952, after reporting a burglary to the police and inadvertently revealing his sexual history in the process, Turing was arrested and charged with “acts of gross indecency”.

He was sentenced to a choice between imprisonment and chemical castration. In order to continue his work, Turing chose the latter. The oestrogen injections he was administered caused him to become impotent, and grow breasts – a brutally humiliating experience that Turing handled with as much defiance as he could. However, his publicised homosexuality was regarded as a national security issue, and Turing feared it would undermine his credibility. In a distressed letter to a friend, he wrote, “I’m afraid that the following syllogism may be used by some in the future: Turing believes machines think / Turing lies with men / Therefore machines do not think.”

The pressure took its toll. Two years after his conviction, Turing committed suicide. He left no note – only a half-eaten apple on his bedside table. Exactly how he died is unclear. It’s been speculated, but never proven, that Turing laced the apple with cyanide as a grim homage to his favourite film Snow White and the Seven Dwarves. If so, it’s incredibly bittersweet to think that Apple’s logo is a tribute to Turing, that every last Apple device is bearing a ghost of its ancestor. While this isn’t strictly true (it’s meant to be a “byte” from the apple of knowledge), Steve Jobs did once say that he wished it had been a Turing reference. Interpret at will.

Corporate branding aside, it’s hard to understate the far-reaching scope of Turing’s legacy, as computation has triggered paradigm shifts in almost any field you care to name. “We can only see a short distance ahead,” Turing once wrote, “but we can see plenty there that needs to be done.” Of course, he was referring to his research. But given his suffering at the hands of an unjust system, Turing’s words are also a poignant reminder of the necessity of constant socio-political progress alongside our technological advances.

If you, or someone you know, needs help you can call Lifeline on 13 11 14 (www.lifeline.org.au), Suicide Call Back Service on 1300 659 467 (www.suicidecallbackservice.org.au), or beyondblue on 1300 22 4636 (www.beyondblue.org.au).