Alan Turing out of the shadows
Source: Giles Broadbent

Mathematician and genius Alan Turing burnt bright and brilliant and briefly yet, for all that he was, he was never appreciated in his lifetime beyond the confines of his peers.

The conspiracies and circumstance set in place to ensure he remained obscure appear formidable.

Firstly, he operated in great secrecy in the (now) legendary Bletchley Park, helping to decipher the Nazi Enigma code.

There was an unbreakable bond of silence among Bletchley veterans that kept their work secret long after it needed to be so. War time leader Winston Churchill called his codebreakers "the geese that laid the golden eggs and never cackled".

So effective was this secrecy that Bletchley's (and Turing's) remarkable advances only began to emerge in the '80s and 90s. By that time, the notion that the US was the pioneer of the computer age was firmly entrenched and Turing long dead.

Secondly, he was gay at a time when to be so was illegal and, in society's eyes, shameful.

An inquest ruled he committed suicide at the age of just 41 after swallowing a bottle of cyanide - although the verdict has been called into question.

It was 1952 and he had been convicted for committing a homosexual act and, in doing so, lost his security clearance and access to his computers.

David Rooney, curator on the Science Museum's new Code Breaker exhibition, said "Turing, who had undoubted eccentricities, was regarded with affection by colleagues. His treatment at the end of his life is a source of national shame.

"The exhibition is an opportunity to present the remarkable work of a man whose influence reaches into perhaps the most widespread pastime of the 21st century, the use of the personal computing device, yet whose name is probably unfamiliar."

If the secrecy was a constant guard against recognition, there was a third obstacle: the field in which he chose to excel - maths and computational science is fiendishly complex.

Indeed, if there is a weakness in the excellent and moving exhibition marking the centenary of his birth, it is in the nature of the exhibits.

While they are authentically dented, scraped, dusty and aged, their metal carapaces, occasional flick-switches and lack of recognisable function promote the idea they are the pointless products of abstract mind games.

In fact, these were the machines that took mechanical calculating devices - the sort that Victorian Charles Babbage would recognise - and pushed them on to the utilitarianism of the computer.

Key to that journey was the philosophical and conceptual framework of the computing device - Turing wrote the rulebook. He outlined what a computer was, how it would function, what it would do.

One of his legacies is a hypothetical device called a Turing machine - a device that simulates the cold logic of a computer algorithm.

But the exhibition demonstrates that Turing was far from such a machine himself.
On show are personal letters that soften the hard reproach of his familiar dark-eyed portrait to reveal a very human soul.

He lost a friend to TB when they were very young and his letters to the boys' mother are sensitive, supportive and insightful.

Rooney said: "We are able to show a more complete portrait of the man who, far from being the lone genius of popular belief, can be seen as a character with many endearing qualities."

Such was the extraordinary and devastating impact of Christopher Morcom's death, that it incubated in Turing the thought - or maybe the wish - that the mind could survive the body, a philosophical question that took him to psychic and paranormal investigation and on to the first stirrings of artificial intelligence.

Who knows where he would have ended up had he lived to yoke the extraordinary power of modern computers to his unfettered imagination and precise humanity?

In 2009 Prime Minister Gordon Brown apologised on behalf of the nation for the "appalling way" Alan Turing was treated simply for being gay.

Fittingly, pressure for an apology arose from an online petition to No.10 - an army of binary digits rallying to redeem their first champion, perhaps?

■ Code Breaker: Alan Turing's Life And Legacy, FREE, Science Museum, until June 2013, sciencemuseum.org.uk.

Science Museum conservator Bryony Finn inspects the Pilot ACE computer - formerly the fastest computer in the world in the 1950s and fundamentally designed by Alan Turing