# Alan Turing

## A Brief History

Alan Turing was a mathematician, logician, philosopher and more famously a cryptanalyst (as shown in the film "The Imitation Game"). However, he was also very important in the development of computers. He designed many things, including the ACE (Automatic Computing Engine) and although the full version was never built, it's fundamentals were used in a number of other computers. He also put forward an experiment (later coined the Turing Test) in an attempt to put borders on where a machine can be considered intelligent. In this paper, he also suggested that instead of designing computers to simulate an adult mind, it should be designed to simulate a child's mind and then be put through an education program.

## Turing Test

Turing named this clever test after him and it is still used today (recently used in an episode of Elementary). It involves questioning artificial intelligence devices to test if their answers are both intelligent and could be answers that a human would give if asked the same question. If both are yes, continue questioning until a flaw is found.
The Imitation Game - Official Trailer - The Weinstein Company

## WWII - The Bombe and The Enigma Machine

In WWII, the Germans would communicate using encrypted messages sent between U-boats. These would be encrypted using the Enigma machine, a machine that encoded messages using 3 dials that randomly changed after each character was typed, completely randomising each individual character. Alan Turing devised a machine that replicated the process of numerous enigma machines wired together. This machine rapidly tested various configurations of the enigma coding until it eventually turned up a result. This was a breakthrough for cryptanalysts and revolutionised cryptology. It changed the course of war and is still remembered today.
Alan Turing's Bombe Reconstruction

## Bombe reconstruction

Above is a reconstruction of the original Bombe machine recorded live. As you can see, each test is 3 dials above each other. This set is replicated numerous times. The spinning is just the many different configurations. The top ones constantly spin to constantly change the first dial. The second one rotates after every full rotation of the first one to change the second dial and the third one would rotate after every full rotation of the second one to change the third dial. This is repeated until the decoding gives a clear message.