Turing over his lifetime produced various groundbreaking seminal papers and works. In this write-up, I am going to delve into four such major works: "On Computable Numbers, with an Application to the Entscheidungsproblem" (1936); Bombe and Spider, Banburismus (1940–41); Computing Machinery and Intelligence (1950); Solvable and Unsolvable Problems (1954). David Hilbert and Wilhelm Ackermann discussed Entscheidungsproblem in their 1928 writing, The Principles of Mathematical Logic. They posed universal validity and satisfiability, which customarily was referred to as the decision problem (Hilbert et al., 1950). The decision problem can hence loosely be defined as coming up with an algorithm that takes an input and replies with a Yes or No depending on whether the statement is universally satisfiable.

Computer historians have staged a re-enactment of World War Two code-cracking at Bletchley Park. A replica code-breaking computer called a Bombe was used to decipher a message scrambled by an Enigma machine. Ruth Bourne, a former wartime code-cracker who worked at Bletchley and used the original Bombes, oversaw the modern effort. Enigma machines were used extensively by the German army and navy during World War Two. This prompted a massive effort by the Allies to crack the complex method they employed to scramble messages.

The UK's National Museum of Computing has expanded its exhibits celebrating the UK's wartime code-breakers and the machines used to crack German ciphers. On Saturday it will open a gallery dedicated to the Bombe, which helped speed up the cracking of messages scrambled with the Enigma machine. The Bombe was formerly on display at Bletchley Park next door to the museum. A crowd-funding campaign raised £60,000 in four weeks to move the machine and create its new home. The replica Bombe is a copy of the electro-mechanical machines used in World War II at Bletchley.

In this article, which is Part 2 of a series tracing the concept of artificial intelligence from its inception, we pick up the story with Alan Turing, who is considered by many to be the "father" of computer science. As we shall see, Alan Turing has a credible right to be called not only the father of computer science but one of the earliest pioneers in artificial intelligence (or machine intelligence, as he would have called it). For this reason, I devote considerable attention to his brief but remarkable career, including some biographical details. I repeat my disclaimer that I am not a professional historian. Instead, I hope this series of articles inspires others to further study this fascinating history, as well as providing insight into what "artificial intelligence" actually means.

Science author Simon Singh is stood beside an Enigma machine, talking about the 15,354,393,600 password variants the German encryption box allows with its spaghetti of wiring, pseudo-random rotors and reconfigurable plugboard. He's talking about the top secret work at Bletchley Park to break the code - the groundwork lain by Polish mathematicians; Alan Turing's bombe; years of frustrated efforts waiting for a breakthrough. Behind him, a screen shows that an artificial intelligence has cracked it in 13 minutes. The stunt is being made by a data analysis firm. It is showing off its machine learning toolset with a live demonstration, competing with the very best in 1930s encryption.

May 14, 2017, will be the 100th anniversary of the birth of someone you might not have heard of: William Thomas ("Bill") Tutte. During the Second World War he made several crucial contributions to decrypting the Lorenz cipher used to protect the Nazi high command's most crucial radio communications. This work provided the statistical method implemented electronically by Tommy Flowers, a telecommunications engineer, in the Colossus machines, which pioneered many of the electronic engineering techniques later used to build digital computers and network equipment.a The British code-breaking effort of the Second World War, formerly secret, is now one of the most celebrated aspects of modern British history, an inspiring story in which a free society mobilized its intellectual resources against a terrible enemy. That's a powerful source of nostalgic pride for a country whose national identity and relationship with its neighbors are increasingly uncertain. Tutte's centennial gives a chance to consider the broader history of Bletchley Park, where the codebreakers worked, and the way in which it has been remembered. Some kinds of people, and work, have become famous and others have not. Films reach more people than books. So statistically speaking, most of what you know about Bletchley Park probably comes from the Oscar-winning film The Imitation Game. This gives us a starting point: the film is a bad guide to reality but a useful summary of everything that the popular imagination gets wrong about Bletchley Park. One myth is that Alan Turing won the war pretty much by himself.