WHO WAS HE ?
As the youngest son of Julius Mathison Turing and Ethel Sara Turing, Alan was born on the 23 June 1912 in London, following his parents’ relocation from India where they had lived for some years prior.
Both parents were from prominent Scottish and Irish families and Alan’s upbringing was a privileged one within the Maida Vale and Guildford districts of the city. His brilliant mind and penchant for mathematics shone through from an early age, earning him a degree from King’s College, Cambridge and a PhD from Princeton. He is widely known for his work at Bletchley Park during the Second World War, where he and his team cracked the German Enigma code and, according to some, his work shortened the war by years and saved millions of lives.
One of the most influential minds behind theoretical computer science, Turing is the father of our modern computers and artificial intelligence; an achievement that for the longest time was overshadowed and unrecognised due to his tragic suicide in 1954 and the prejudice he faced following his criminal conviction for homosexuality two years prior to his death.
Alan Turing’s intelligence shone from an early age, his mathematical and scientific abilities recognised by teachers and also, in some instances, disdained by his educators. Coming from an upper-middle class family who had been involved in imperial administration prior to the first world war, it was expected that Turing would adhere to the traditional emphasis on classics, as seen in public schools of the era. Yet, somewhat detached from social obligations and as part of a generation that desired to veer away from the Victorian values that had dominated society, Turing’s passions lay in mathematics and science and it was in these subjects that he excelled.
After graduating from King’s College with distinction in 1934, Turing was introduced to M. H. A. Newman’s lectures on the frontier of mathematical logic, but it was his work in probability theory that earned him a Fellowship of King’s College in 1935. Newman’s lectures had a lasting impression on Turing, and he ventured into the field of mathematical logic, producing his famous paper “On Computable Numbers, with an Application to the Entscheidungsproblem,” in 1936-7.
At only twenty-three years old and working alone, his paper ‘solved’ the outstanding Entscheidungsproblem, by showing that there could be no general method for deciding the provability of mathematical propositions. His findings remains definitive to this day.With his position cemented within the field of mathematical logic, his paper would also open up new fields, which we would recognise today as computer science and the cognitive sciences.
THE UNIVERSAL TURING MACHINES
While Turing’s work on the Entscheidungsproblem classed him as a logician, he is likened more to a mathematician who applied himself to logic. It was this combination, his concern with the fundamental questions of mind and matter and his background in physics, which saw the “Turing Machines” come to fruition. A symbol of the modern world, these machines were a mathematical model of computation, a representation of an algorithm that can be seen in a modern computer program.
Following the development of the “Turing Machine”, he accepted a position on Alonzo Church’s team at Princeton University to research more advanced logic and to work on developing the theory of the Riemann zeta-function, which was crucial to the study of prime numbers.
WORLD WAR TWO
Turing returned to England from Princeton University in the summer of 1938. A year later war was declared with Germany. As with the war that had encapsulated the world only a few decades prior, those within the scientific fields were tasked with developing new technologies that could help the allies and potentially shorten the war. While many of his contemporaries explored the development of radar and weaponry, Turing ventured into the field of cryptology.
The Enigma machine had been known to the allies for some years prior to the outbreak of war; the German army had begun using it as early as1920, as it enabled them to send cryptic messages that could not be deciphered unless the recipient had the correct ‘key’. In the early 1930s, two Polish mathematicians made a significant breakthrough with Enigma and at the outbreak of war, intelligence was traded to the British and French.
At this time Turing had taken a full-time role at Bletchley Park and his main focus was to crack the Enigma code, building upon research by the Polish mathematicians, Turing needed to work around the increased security that the Germans had implemented at the start of the war. A machine known as the Bombe was developed by Turing and Gordon Welchman, helping reduce the work of the code-breakers.
Turing also worked on decrypting the German naval communications, which proved to be a crucial task considering the heavy losses German U-boats were inflicting on the allies. Heading the ‘Hut 8’ team at Bletchley, he developed a technique called ‘Banburismus’ which allowed the naval Enigma messages to be read from 194, and proved to be pivotal in helping the allies during the Battle of the Atlantic.
During his wartime work he also developed a complex code-breaking technique that he named ‘Turingery’, and travelled to the US in late 1942 to share his knowledge of Enigma with US military intelligence. Turing’s final contribution to cryptanalysis during the war years was his development of a speech scrambling device named ‘Delilah.’
POST WAR LEGACY
For his work during the second world war, Turing was awarded an OBE, but like others who had worked at Bletchley Park, the precise nature of his work there was kept secret until the 1970s. Even then, Turing’s full contribution and impact on the war was not known until the 1990s. Nevertheless, his post-war prospects were promising and he was offered a position at the National Physical Laboratory (NPL) in 1945, and his proposal for the Automatic Computing Engine (ACE) was adopted in March 1946.Sadly, his genius seemingly outweighed technological capabilities at the NPL, and he became dissatisfied with his work there.
Encouraged by Max Newman, his former Cambridge professor, Turing took a position at Manchester University as the Deputy Director of the Computing Laboratory.Here, his work began to focus upon the futuristic prospects of Artificial Intelligence, developing the test of the ‘imitation game’ or the Turing test as it’s now known, which measures a machine’s ability to exhibit intelligent behaviour.
In 1952, Turing begun a relationship with a man named Arnold Murray, and soon afterwards Turing’s home was burgled. During the police investigation, the sexual relationship between Turing and Murray was revealed and the two men were arrested and charged with “gross indecency” under Section 11 of the Criminal Law Amendment Act 1885.
Their case was brought to trial in February 1954 and Turing entered a guilty plea that warranted him a conviction and choice of imprisonment or probation, on the proviso that he undergo hormonal “treatment” to decreased his libido – he chose the latter. The “treatment” took a significant toll on Turing. The side effects of the hormonal “treatment” were severe and his conviction led to him losing his security clearance for consulting in governmental cryptanalysis, though he did keep his job at the university.
On 8 June 1954, Alan Turing was found dead by his housekeeper at his home in Wilmslow. He was aged 41. Cyanide poisoning was established as the cause of death, and suicide was determined, though some have disputed that his death was accidental.
For a long time after his death, Alan Turing’s contribution to the war, as well as his contributions to the field of computer sciences, largely went unrecognised. It was not until the 1990s that his wartime work in cryptanalysis became declassified and his instrumental decoding of the Enigma codes became widely recognised.
His statue in Sackville Park, Manchester, was unveiled on the 23 June 2001 and is symbolically placed between the University of Manchester, where he worked post-war, and Canal Street, where Manchester’s gay village is located. The memorial statue was championed by Richard Humphry, a Stockport barrister who set up the Alan Turing Memorial Fund to raise funds.
The memorial was designed by Glyn Hughes, who depicted Turing in bronze, sitting on a bench and holding an apple, with a plaque at his feet which reads: Alan Mathison Turing 1912-1954, Father of Computer Science, Mathematician, Logician, Wartime Codebreaker, Victim of Prejudice.
Not only was Turing an unrecognised war hero in his lifetime, he was also unjustly persecuted for his sexual orientation. His life was extraordinary in many ways: he was a genius in every sense of the word, helping to shorten the war and save countless lives in breaking the Enigma code alongside his team at Bletchley Park. Furthermore, his academic work helped to pave the way for what we know today as computer science and artificial intelligence.
The tragic legacy of his criminal conviction is a poignant reminder of the persecution that the LGBTQ+ community has historically faced, and in some instances continues to face in the fight for a more equal and accepting society.