Turing was the Bombe

(S)

A few weeks ago I wrote about Lynn Conway, a computer scientist without whom we would not have most of the computer technology you use today, or many of the methods that computer scientists are taught to use in university. However, there is a man whose name has become synonymous with computers and computer science, and is probably the first name that everyone supplies when asked, “Are there any QUILTBAG scientists?” 

Alan Mathison Turing is arguably the reason that computers – and especially artificial intelligence – exist at all. 

Turing was a very determined child. In 1926, he was enrolled at Sherborne School, a well-known independent school in the market town of Sherborne in Dorset. The first day of term, however, coincided with the 1926 General Strike, in which around 1.7 million workers from the transport and heavy industry sectors walked out to protest wage reductions and worsening conditions for coal miners. Rather than accepting that he would miss the start of term, Turing traveled the sixty miles (that’s nearly one hundred kilometres) to the school from where he lived in Southampton. By bicycle. Unaccompanied. 

He was thirteen at the time. 

At fourteen he was solving advanced problems in maths, without having previously studied simple calculus. At sixteen he found the work of Albert Einstein, and understood it well enough to understand that Einstein was implicitly questioning Newton’s laws of motion in one paper. Despite his aptitude for science and maths, the school’s headmaster wrote to his parents saying, “If he is to stay at this school, he must aim at becoming educated”. The school defined education by the classics subjects rather than the sciences, and so Turing did not earn much respect from his teachers. 

Then, in 1936, at age 24, he wrote a paper in which he described what is now known as a Turing Machine. A Turing Machine is a hypothetical mechanical device that alters symbols on a strip of tape. Turing proved that these machines would be capable of performing any conceivable mathematical computation if it were represented as an algorithm. Turing Machines are still a central part in the study of the theory of computation. 

After this we get to one of Turing’s achievements that everybody knows. From September 1938, Turing worked part time with the Government Code and Cypher School, which was a British code breaking organisation. The day after Britain declared war on Germany, September 4th 1939, Turing was moved to Bletchley Park – the School’s wartime base. 

A worker using a Bombe at Bletchley Park (S)

There, Turing developed the Bombe (yes, I am sorry for the terrible pun in the title), to break the German Enigma Code. The Bombe searched for possible correct settings used for an Enigma message. The rotors for the Bombe were of the order of 1019 states (in other words, for the less mathematically minded, there were 100,000,000,000,000,000,000 possible combinations that the Bombe could test for. A whole heap of combinations, in other words). 

Using the Bombes that had been developed, Turing and the other scientists at Bletchley Park went about decoding each message that they could find. However, the amount of messages that needed to be decoded were far too numerous, and so on the 28th October 1941, they broke every rule and wrote directly to Churchill himself to ask for more resources. By the end of the war, there were nearly 200 Bombes in operation. 

Oh, and did I mention that he occasionally ran the forty miles to London for meetings, just because he could? 

From 1945 to 1947, Turing lived in Richmond, London, and worked on the design of the Automatic Computing Engine (ACE) at the National Physical Laboratory. In 1946 he published the first detailed paper about a computer that could theoretically store programs in its internal memory. Although feasible, Turing’s own ACE design was never built. In 1949, he became Deputy Director of the Computing Laboratory at the University of Manchester, working on software for one of the earliest stored-program computers—the Manchester Mark 1. 

Despite being busy with creating an entirely new form of computer, Turing still had time for different lines of research, and proposed a standard for a computer or machine to be defined as “intelligent”. The Turing Test was simple – a computer could “think” if a human interrogator could not tell its responses were from a machine and not another human. In 1990, The Loebner Prize in Artificial Intelligence was created. Dr Hugh Loebner offered a grand prize of $100,000 and a gold medal for the first computer to fully pass the Turing Test. Every year a bronze medal and $2000 is awarded to the most human-like computer, compared to the other entries, but so far nobody has actually been able to claim the grand prize. 

Online computer programs that simulate artificial intelligence in this way are fairly common – two examples are CleverBot and iGod. A reverse form of a Turing Test is used on some sites to determine if a user is a human or not. This is known as CAPTCHA. 

The January of 1952 was around where Turing’s life changed for the worse. After meeting a young man called Arnold Murray, and spending a few nights together, Murray helped an accomplice to break into Turing’s home. In reporting this to the police, Turing admitted to a sexual relationship with Murray. Homosexual acts were illegal in the United Kingdom at the time, and both were charged with gross indecency. He pleaded guilty to the charges and was given a choice between being imprisoned or undertaking hormonal treatment - designed to decrease libido. He chose the latter, and was injected with stilboestrol, a synthetic oestrogen, for a year. It rendered Turing impotent, and made his body more feminine as a side effect. 

On the 7th June 1954, Turing died due to cyanide poisoning. He was found the following day by his cleaner. 

Since then there have been many different tributes to Turing and his work – both in cracking the Enigma Code (and quite possibly winning the war for the Allies there) and in fathering the algorithms that would come to be used in the modern computer with artificial intelligence. Whenever anyone compliments his genius, however, there always has to be the question: 

If Turing hadn't been persecuted for being gay by the media and the public, how much further forward in computer technology would humanity be?