When we look back at some of the greatest scientific minds of the 20th century, one name, in particular, will stand out for the sheer breadth and enormity of his contributions to the world – Alan Mathieson Turing. Unlike theoretical physicists Albert Einstein, virologist Jonas Salk, physicist Niels Bohr or other great thinkers of the period, Turing’s work spanned across multiple scientific disciplines encompassing mathematics, computer science, artificial intelligence, cryptanalysis, chemistry, and theoretical biology. His entire legacy to the scientific community and the world at large will probably take a book or two to list down, but the following four are arguably considered as his greatest contributions to modern science.
The statue of Alan Turing at Bletchley Park in Milton Keynes. Image courtesy of Christine Matthews.
1. The Turing Machine
In his 1936 paper, “On Computable Numbers, with an Application to the Entscheidungsproblem,” Turing developed the Turing Machine, an abstract device, to tackle German mathematician David Hilbert’s Entscheidungsproblem (decision problem). Essentially, the Turing Machine is a hypothetical a-machine (automatic machine) designed to resolve any solvable problem using a limited set of simple rules (m-functions) in a finite amount of time. These computable sequences can be calculated by a universal computing machine, which is fundamentally similar to electronic calculators, web browsers or computers.
The Turing Machine has been cited by many as one of the most important elements in the early development of computer science; so much so, many consider him as the ‘Father of Computer Science.” Legendary Welsh philosopher Bertrand Russell went a step further by naming his as “the godfather of all modern computers.”
2. Bombe: Cracking the German Enigma Code
In 1938, while still at the University of Manchester, Turing began working part-time for the country’s Government Code and Cypher School. When the British declared war on Germany the following September, Turing was roped into the Hut 8 unit of Bletchley Park, the government’s secret codebreaking division.
Outside of the atomic bomb, Turing’s success in developing the algorithm and device to crack the German Enigma and Tunny codes, nicknamed Bombe and Turingery, is arguably the single most decisive factor in the Allied nations’ victory against the Axis in World War II. His discovery, which allowed the Allied forces to listen to the communications of the formidable German Navy, is estimated to have shortened the war between two and four years, and in the process, saved approximately 14 to 21 million lives.
His work at Bletchley didn’t end there though. Turing also developed a cryptographically secure encoding algorithm for telephone communications, nicknamed Delilah, which would serve as the basis behind the Allied’s communications network.
3. Biological Morphogenesis
Two years before his untimely death, Turing took a huge detour from his comfort zone to delve into biological morphogenesis. In his 1952 paper, The Chemical Basis of Morphogenesis, Turing used mathematical calculations to demonstrate that the chemical responses behind the random development of biological shapes and patterns, now termed Reaction-Diffusion Model, do not fit into preconceived evolutionary models – a conclusion that has only been proven in the last couple of years.
4. DIY Computer?
Turing’s impact on the field of computers is not limited to theory; he was actively trying to build them as well. During the final stages of World War II, Turing was seconded to MI6’s (the British intelligence agency) Hanslope Park research unit. While there, he wrote a paper detailing the construction of an ACE (Automatic Computing Engine), a computing device capable of calculating complex mathematical equations. The estimated cost of ₤11,200 was deemed to be too expensive at the time by the Executive Committee of the National Physical Laboratory, and the project was temporarily shelved.
However, the project was resurrected after the war, and a working prototype was completed in 1958, making it the world’s first electronic computer. The development of ACE, alongside the American-built UNIVAC I, would spearhead the growth of the embryonic physical computing sector for the next couple of decades.
How did Alan Turing Died?
Turing’s final years, unfortunately, proved to be spectacularly anti-climactic, from his conviction of indecency for homosexuality, to chemical castration, and ultimately, death from potassium cyanide poisoning (believed by many to be a suicide). However, Turing received a posthumous royal pardon from Queen Elizabeth II in 2013 for his conviction, and his name and reputation has enjoyed a renaissance in recent years. Which is the very least he should expect, considering the incredible contributions he has made to the world.
Song of the day: Richard Ashcroft – Science Of Silence