Alan Turing

Computer Components

Turing's most important contribution, was of part of the design of the bombe, the cryptanalytic machine. He had the idea that you could use, in effect, a theorem in logic which sounds to the untrained ear rather absurd; namely that from a contradiction, you can deduce everything.

The man that changed the world!

This flyer is all about Alan Turing.
It will explain who he was, a bit about his life and what he did that was so amazing!

But think about this question first, what would you do without your computer of electronics?

Who was he?

Alan Turing was born in Paddington, London on 23rd June, 1912. He was the son of a clergyman from a Scottish family of merchants which had been based in the Netherlands. Very early in life, Turing showed signs of the genius he was later to display prominently. His parents enrolled him at St Michael's, a day school at the age of six. The headmistress recognised his talent early on, as did many of his subsequent educators. In 1926, at the age of 13, he went on to Sherborne School, a well known independent school in Dorset. The first day of term coincided with the 1926 General Strike in Britain, but so determined was he to attend that he rode his bicycle unaccompanied more than 60 miles (97 km) from Southampton to Sherborne, stopping overnight at an inn.In 1928, aged 16, Turing encountered Albert Einstein's work; not only did he grasp it, but he extrapolated Einstein's questioning of Newton's laws of motion from a text in which this was never made explicit.

What next?

After Sherborne, Turing studied as an undergraduate from 1931 to 1934 at King's College, Cambridge, from where he gained first-class honours in mathematics. In 1935, at the young age of 22, he was elected a fellow at King's on the strength of a dissertation in which he proved the central limit theorem. From September 1936 to July 1938, he spent most of his time studying under Church at Princeton University. In addition to his purely mathematical work, he studied cryptology and also built three of four stages of an electro-mechanical binary multiplier. In June 1938, he obtained his PhD from Princeton.

The Bombe!

This is what Alan Turing is most famous for.
In WW11, the Germans used codes to send secret messages. They used a device called Enigma. Enigma was a typewriter that when you pressed a letter, a dial twisted and a different one came up. For example, if you wrote the word computer, it may come up as fysbfwk. But if you wrote it again, it may come up as dqclgzt because of the dials. Enigma was meant to be unbreakable, but that didn't stop people trying!

Just after war had broke, Alan made his way to Bletchley Park - a big house in Buckinghamshire - was where all the code breaking and secret messaging happened in the war. It was there he showed everyone his idea's for the Bombe.
The Bombe was an electro-mechanical device that replicated the action of several Enigma machines wired together. A standard German Enigma employed, at any one time, a set of three rotors, each of which could be set in any of 26 positions. The standard British bombe contained thirty six Enigma equivalents, each with three drums wired to produce the same scrambling effect as the Enigma rotors. A Bombe could run two or three jobs simultaneously. Each job would have a menu that had to be run against a number of different wheel orders. If the menu contained 12 or fewer letters, three different wheel orders could be run on one bombe; if more than 12 letters, only two.The bombe drums were arranged with the top one of the three simulating the left-hand rotor of the Enigma scrambler, the middle one the middle rotor, and the bottom one the right-hand rotor. The top drums were all driven in synchrony by an electric motor. For each full rotation of the top drums, the middle drums were incremented by one position, and likewise for the middle and bottom drums, giving the total of 26 × 26 × 26 = 17,576 positions of the 3-rotor Enigma scrambler.

The Bombe - continuted

The drums were colour-coded according to which Enigma rotor they emulated: I Red; II Maroon; III Green; IV Yellow; V Brown; VI Cobalt (Blue); VII Jet (Black); VIII Silver.

At each position of the rotors, an electrical current would or would not flow in each of the 26 wires, and this would be tested in the bombe's comparator unit. For a large number of positions, the test would lead to a logical contradiction, ruling out that setting. If the test did not lead to a contradiction, the machine would stop.

The operator would record the candidate solution by reading the positions of the indicator drums and the indicator unit on the Bombe's right-hand end panel. The operator then restarted the run. The candidate solutions, stops as they were called, were processed further to eliminate as many false stops as possible. Typically, there were many false Bombe stops before the correct one was found.

The candidate solutions for the set of wheel orders were subject to extensive further cryptanalytic work. This progressively eliminated the false stops, built up the set of plugboard connections and established the positions of the rotor alphabet rings.Eventually, the result would be tested on a Typex machine that had been modified to replicate an Enigma, to see whether that decryption produced German language.

While Turing's bombe worked in theory, it required impractically long cribs to rule out sufficiently large numbers of settings. Gordon Welchman came up with a way of using the symmetry of the Enigma stecker to increase the power of the bombe. His suggestion was an attachment called the diagonal board that further improved the Bombe's effectiveness.

Basically, the Bombe was the worlds first computer. And these designs of programming lead to thinking about smaller versions, but for everyday life.

What happened afterwards?

After the war, Alan Turing was awarded an OBE. He was given lots of praise too.
Unfortunately, it was found out after that Alan had a dark secret, and it had got out. Alan Turing was gay. In the 1950's, this was frowned upon lots and after admitting it, Turing was given the option of imprisonment or to have medical treatment. He chose the second.
A short time after this, Alan Turing was found dead. Next to him lay an apple that was believed to be filled with cyanide - a poisonous chemical. Traces of cyanide were also found in his stomach and other organs. It was decided that he killed himself.

So there you have it! Alan Turing an the worlds first computer!

This a a short documentary about Alan Turing
Alan Turing - Celebrating the life of a genius
This is the trailer to a movie made all about Alan Turing and the Bombe
The Imitation Game - Official Trailer - The Weinstein Company