The history of his life

Transcription

1 One of the most important scientist of the history, father of the artificial intelligence. A man that, during the second world war, saved millions of people and who was sentenced because homosexual. Alan Turing

2 The history of his life Alan Mathison Turing was born on 23 June 1912, the second and last child of Julius Mathison and Ethel Sara Turing. His father Julius had entered the Indian Civil Service, serving in the Madras Presidency, and had there met and married Ethel Sara Stoney. Although likely conceived in British India, in the town of Chatrapur, Alan Turing was born in a nursing home in Paddington, London. Turing appears now as the founder of computer science, the originator of the dominant technology of the late twentieth century.

3 Alan Turing's story wasn t one of family or tradition but of an isolated and autonomous mind. Alan shared with his brother a childhood rigidly determined by the demand of class and the exile in India of his parents. Until his father's retirement from India in 1926, he and his major brother John were fostered in various English homes where nothing encouraged the expression, originality, or discovery. At twelve he expressed his conscious fascination with using 'the thing that is commonest in nature and with the least waste of energy, presentiment of a life seeking freshly minted answers to fundamental questions. The stimulus for effective communication and competition came only from contact with another very able youth, Christopher Morcom, at the Sherborne School, to whom Alan Turing found himself attracted in He gave Turing a vital period of intellectual companionship which ended with Christopher's sudden death in February Turing's conviction that he must now do what Christopher couldn t. For three years at least, his thoughts turned to the question of how the human mind, and Christopher's mind in particular, was embodied in matter; and whether accordingly it could be released from matter by death. In 1931 he entered to the prestigious academy of Cambridge and at the same time, the homosexuality became a definitive part of his identity. His hobby were rowing, running and a small sail boat.

4 In 1935, Turing attended the lecture course of the Cambridge topologist M. H. A. Newman and tried to give an answer to the question posed by David Hilbert: could there have existed, at least in principle, a definite method or process by which it could be decided whether any given mathematical assertion was provable?. Turing analysed what could be achieved by a person performing a methodical process, and seizing on the idea of something done 'mechanically', expressed the analysis in terms of a theoretical machine able to perform certain precisely defined elementary operations on symbols on paper tape: the Turing machine.

5 The Turing Machine Alan Turing with this machine wanted to replicate human thought and by sequences of elementary steps to find a solution to every problem: the modern concept of algorithm. The machine can act on a tape that is presented as a sequence of boxes in which they may be recorded symbols of a well-defined finite alphabet; it is equipped with a reading head and writing (1 / 0) which is able to perform operations of reading and writing on a box of the tape. The machine evolves in time and at any instant can be found in an internal state of well-determined part of a finite set of states. Initially on the tape is placed a string that represents the data that characterize the problem that is subjected to the machine. The machine is also equipped with a repertoire of finished instructions that determine its evolution as a result of the initial data. Characteristic of Turing Machine is to have a tape potentially infinite, that is extensible as you want if this is necessary.

6 The Turing Test Alan Turing was the first to believe they can create a machine capable of reasoning and is therefore considered the father of artificial intelligence. He published in 1950 in the journal Mind article "Computing machinery and intelligence", a special test for determining whether a machine would be able to "think". Turing imagined a situation in which a man A and a woman B would provide answers typed C To a person who was then having to decide which of them was a man or woman. In the event that a machine takes the place of A or B, if the verdicts delivered by C were statistically identical to the previous situation, then the machine could be considered thinking. The Turing test has been repeatedly criticized and reworked, and still no machine has proven to be able to overcome.

7 After university Alan Turing worked for the British Secret Service (MI5) and during the Second World War gave a decisive contribution to the realization of the Bombe, the machine that allowed to decipher the famous enigma code used by the Nazis and until then considered indecipherable. Thanks to the work of Alan it was able to understand the messages of the Germans, anticipate their attacks and save millions of people. The Enigma machine Enigma was an electromechanical machine cipher used by the Germans during the Second World War to encrypt their communications and make them so incomprehensible to enemies. It was invented in 1918 by Arthur Scherbius with the aim of ensuring the industries a system to protect their information by the spread of industrial espionage, but was unsuccessful because of its high costs. It was instead greeted with enthusiasm and purchased in bulk by the Nazi government for the ease of use and the alleged indecipherable of its language, since its internal structure was changed every day.

8 The Enigma machine looked like a typewriter with two keyboards: a true bottom, and the second made of bright letters that were lit at every key pressed on the keyboard: the sequence of letters that lit gave the encrypted message (or that clear, if you beat the ciphertext). Its operation was based on three wired discs, said rotors, which had 26 contacts per side (one for each letter of the German alphabet ): at the wiring of the discs,each letter put in communication one side with a letter on the other side. These three rotors were changed daily at midnight so as to make the Enigma code unreadable, except by a powerful machine and at a very high cost. This machine was built thanks to government funds by the British team "Ultra" led by Alan Turing at Bletchley Park: Bombe. Every morning Bombe calculated all the possible ombinations of the rotors In just twenty minutes, making every German message, decipherable.

9 After the war Alan Turing worked on other important governative projects, but in 1952 he was sentenced for homosexuality and he died, committing suicide, after two years of sufferings on the 7th june In the 2009, the British Prime Minister Gordon Brown said: Thousands of people have come together to demand justice for Alan Turing and recognition of the appalling way he was treated. While Turing was dealt with under the law of the time and we can't put the clock back, his treatment was of course utterly unfair and I am pleased to have the chance to say how deeply sorry I and we all are for what happened to him... So on behalf of the British government, and all those who live freely thanks to Alan's work I am very proud to say: we're sorry, you deserved so much better. The work done by Turing and the team Ultra during the war remained secret until 1974 and in 24 december 2013, Queen Elizabeth II bestowed a posthumous pardon for Alan Turing. In addition to his decisive contribution to the outcome of the war, Alan Turing is remembered today for having laid the foundations of computer science and he is called the "Turing Award", a sort of Nobel Prize for computer science awarded annually to personalities who most stands out for their contribution to the scientific community.

10 3B a.s. 2014/2015