Alan Mathison Turing OBE FRS, born on June 23, 1912, and passing away on June 7, 1954, was a remarkable individual whose contributions have left an indelible mark on the world of mathematics, computer science, and artificial intelligence. In this article, we will delve into the fascinating journey of this English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist, often regarded as the father of theoretical computer science and artificial intelligence.
Early Life and Education
Alan Turing was born in Maida Vale, London, and spent his formative years in southern England. He pursued his passion for mathematics, eventually earning a degree in the subject from King’s College, Cambridge. During his time as a fellow at Cambridge, Turing made significant strides, including a groundbreaking proof that showcased the limitations of computational solutions to certain purely mathematical yes-no questions.
The Turing Machine
One of Turing’s most influential contributions to the world of computer science was the development of the Turing machine. This theoretical construct became a foundational model for general-purpose computers, providing a formalization of the concepts of algorithm and computation. Turing’s work on the Turing machine laid the groundwork for the digital age we live in today.
Codebreaking and World War II
During World War II, Turing’s talents were enlisted for a different kind of service. He worked at Bletchley Park, Britain’s codebreaking center, and led Hut 8, the section responsible for German naval cryptanalysis. Turing’s genius played a pivotal role in deciphering intercepted coded messages, which ultimately aided the Allies in crucial wartime engagements, including the Battle of the Atlantic.
After the war, Turing continued to make significant contributions to the field of computer science. He designed the Automatic Computing Engine, one of the earliest blueprints for a stored-program computer. His work extended to the University of Manchester, where he collaborated on the development of the Manchester computers. Additionally, Turing ventured into mathematical biology, proposing concepts related to morphogenesis and predicting oscillating chemical reactions, later observed in the Belousov–Zhabotinsky reaction.
The Unrecognized Genius
Despite his remarkable achievements, Turing was not fully recognized in Britain during his lifetime. Much of his work was shrouded in secrecy due to the Official Secrets Act, which prevented him from receiving the acclaim he truly deserved.
Breaking the Enigma
Alan Turing embarked on a remarkable journey during World War II, tackling the seemingly impossible task of deciphering the German naval Enigma code. His motivation stemmed from the realization that no one else was actively addressing this challenge. Turing’s initial breakthrough in December 1939 involved solving the complex naval indicator system, more intricate than those used by other services.
Banburismus: A Pioneering Breakthrough
On that same fateful night, Turing conceived Banburismus, a sequential statistical technique designed to aid in breaking the naval Enigma. This innovative approach introduced the concept of a “ban” as a measure of weight of evidence. Banburismus enabled the elimination of certain Enigma rotor sequences, significantly reducing the time required to test bombes’ settings. This approach later influenced the Cryptanalysis of the Lorenz cipher.
Turing’s American Adventure
In November 1942, Turing ventured to the United States to collaborate with US Navy cryptanalysts on the naval Enigma and bombe construction in Washington. His American experience, however, left him less than impressed with the American Bombe program. Despite its promise of producing 336 Bombes, Turing questioned its effectiveness. This trip also saw Turing’s involvement in the development of secure speech devices at Bell Labs.
Turingery and the Lorenz Cipher
Turing’s ingenuity extended to devising the Turingery technique to combat the Lorenz cipher messages produced by the Germans’ Geheimschreiber machine. This method focused on deciphering the cam settings of Tunny’s wheels and laid the groundwork for the development of the Colossus computer. Though some mistakenly credit Turing with the Colossus design, his contributions significantly informed the cryptanalysis of the Lorenz cipher.
The Enigma of Delilah
After working at Bell Labs in the United States, Turing turned his attention to electronic speech enciphering for the telephone system. Collaborating with REME officer Donald Bayley, they developed a portable secure voice communications machine called Delilah. Unfortunately, Delilah’s completion came too late for wartime use, but it showcased Turing’s expertise in the field.
Early Computers and the Turing Test
Between 1945 and 1947, Turing worked on the design of the ACE (Automatic Computing Engine) at the National Physical Laboratory in London. His 1946 paper detailed the first comprehensive design of a stored-program computer. While the project was feasible, constraints imposed by the Official Secrets Act delayed its commencement, leaving Turing disheartened. During this period, he also penned a seminal work on Intelligent Machinery and introduced the concept of the Turing test to assess machine intelligence.
Unlocking the Secrets of Morphogenesis
In 1951, at the age of 39, Turing ventured into mathematical biology, publishing “The Chemical Basis of Morphogenesis” in 1952. He explored the development of patterns and shapes in biological organisms, proposing the concept of reaction-diffusion systems to explain morphogenesis. This pioneering work offered a unique perspective on pattern formation in the natural world.
In 1952, Turing faced a different kind of challenge as he was prosecuted for homosexual acts. To avoid prison, he accepted hormone treatment, a procedure commonly known as chemical castration. Tragically, Turing’s life was cut short on June 7, 1954, just 16 days before his 42nd birthday, due to cyanide poisoning. The circumstances of his death remain a subject of debate, with suggestions of both suicide and accidental poisoning.
Recognition and Legacy
In more recent times, Alan Turing’s contributions have been rightfully acknowledged. In 2009, British Prime Minister Gordon Brown issued a public apology on behalf of the government for the mistreatment Turing endured. Queen Elizabeth II granted him a posthumous pardon in 2013. The term “Alan Turing law” now informally refers to a 2017 UK law that retroactively pardoned men convicted under historical legislation that criminalized homosexual acts.
Honors and Commemoration
Alan Turing’s legacy is celebrated through various honors and memorials. His name graces statues, and numerous things are named in his honor, including an annual award recognizing computer science innovations. Notably, Turing’s image now adorns the current Bank of England £50 note, released on June 23, 2021, to coincide with his birthday. In 2019, a BBC series, as voted by the audience, declared him the greatest person of the 20th century.