Decoding the enigma that is Alan Turing, the ghost in his own machine

Behind Paddington Station, underneath a bridge by the canal stands a rectangle of black, perforated, aluminium panels, through which an LED display shows lines of ever-changing words. This is London's latest public art work, dedicated to Alan Turing, one of the fathers of modern computer science, who was born nearby.

The panels are engraved with a hard code version of part of Turing’s groundbreaking work on artificial intelligence “Computing Machinery and Intelligence”.

The constantly changing words on the LED display are based on a new poem by the English writer Nick Drake called "Message from the Unseen World".

In the poem, Turing, who took his own life in 1954, speaks from beyond the grave, talking about his life and commenting on the digitally connected world of today he helped to create. It begins:

“This is Alan speaking

to you who pass by this bridge

in the enchantment of time

under the echoing arch

over the mirror of water

on your way to work or home

and to other places in the infinity

held in the secret dream cave

of your mysterious minds.” Turing is most famous for his wartime role at Bletchley Park in cracking the Enigma code but his name is today almost as closely associated with the persecution of gay men in the 20th century.

A few years after his work on Enigma, which played such an important role in winning the second World War, Turing was arrested for gross indecency and chose to take a course of female hormones rather than go to prison, poisoning himself with cyanide two years later. Public apology   In 2009, Gordon Brown issued a public apology for the state's treatment of Turing, and this week, the House of Lords voted to extend to Northern Ireland the so-called Turing's Law, which allows gay men convicted of sexual offences which are no longer illegal receive a pardon and clear their names.

“This is the most important scientific mind of the 20th century and having achieved what he did, having altered the course of the war, potentially saved the war, invented the computer, invented the future, he was then condemned by a court of justice in the 1950s to a choice, either of prison or of chemical castration, and he chose chemical castration,” Drake says.

“That is a remarkable story which is not played out in the films and it’s a story which I think needs to be remembered, because it’s only 60 years ago. It was only in 1967 that the Sexual Offences Act was repealed, so all the men who were prosecuted and punished along with him, of whom there must have been at least 30,000, perhaps 40,000, they’re not remembered. Nobody knows who they are.”

United Visual Artists, a London-based art practice, have used an algorithm which takes Drake’s poem line by line and then takes every word of that line and works through every possible synonym of it in every possible sequence. The result is an unfolding series of lines, some of which seem familiar from the poem and others which make a very different kind of sense, or no apparent sense at all. ‘Almost no clues’ “That is a kind of Turing idea. It goes back to the idea of how you decode the Enigma code when you have almost no clues about what it might be saying and it changes every day. So you go through every possible combination until you find one that locks,” Drake says.

Drake imagines Turing as the ghost in his own machine, speaking to us about his work in artificial intelligence and computer codes, but also about the secrets which are encoded into human emotion, human sexuality, and most especially into what it meant to be a gay man of his time, and how coded that life was.

In the poem, Turing speaks with longing of the freedom enjoyed by his counterparts today, but suggests that the digital world he helped to create can confine us even as it makes us free.

“I delight to watch you dance

in the enchantment of time

like angels in a forest of mirrors –

but in the age of shopping

festivals and information consumption

the sign of the bitten apple is everywhere

and your lives are held in the beautiful devices

familiar in your hands –

So revel in your liberty

but read between the lines

you are becoming information

touch screen to touch screen

connected but alone

the algorithm of desires and dreams

end to end encryption held

in the infinite memory of the great ghost server”