Saturday, June 23, 2012

100 years of the birth of Alan Turing

This June 23 marks 100 years to the birth of Alan Turing, a mathematician, a pioneer in computer science who contributed in the fields of logic, cryptanalysis, cognitive science, artificial intelligence and biology. Although it is recognized in these fields of science, many times their contribution has not been sufficiently highlighted.

Who was Alan Turing, and why was it so important? A few days after the celebration of his birthday, we will briefly review his life.

Turing was born in London on June 23, 1912, and from an early age showed interest and talent for mathematics, something that would specialize in college then. Turing graduated from King's College, Cambridge in 1934 with honors.

In 1936 he presented one of his first papers relevant. At that time, a problem that was being debated among mathematicians was the Entscheidungsproblem or "trouble-making", proposed in 1928 by German mathematician David Hilbert.

The original problem came from the seventeenth century, when the mathematician Leibniz Gottfrief was perfecting one of the first calculators, and thought of the possibility of creating a machine that could determine the truth of a mathematical approach or theorem. Hilbert put it as a machine that could answer "yes" or "no" to determine whether a claim was universally valid for a predetermined set of axioms. The problem can also be seen as creating an algorithm that can decide when a claim can be corroborated on the basis of the axioms, using logical rules.

Turing machine

The problem is unsolvable, which was tested both by Alonzo Church and Alan Turing in a more or less simultaneously using different methods. The result was embodied in a theorem set.

However, the test proposed by Turing introduced the creation of the Turing machine, a device that manipulates symbols hypothetical tape according to a table of rules.

Despite its simplicity, the Turing machine can be adapted to simulate the logic of any computer algorithm, and is used today in computer theory to explain the functions of the CPU within a computer. Turing proved that such a machine could perform any mathematical computation if it can be represented by an algorithm.

The idea of ​​a "universal machine" that could perform the tasks of any other machine - or be able to compute anything computable - was new at this time.

After this paper, Turing worked nearly two years with Alonzo Church at the Institute for Advanced Study in Princeton, United States. Besides working in mathematics, Turing began to study encryption or cryptography. In June 1938 obtained his Ph.D. from Princeton University.

World War II

After completing his doctorate, Turing returned to Cambridge, where he began working part time at the School Government Code and Cipher (GCCS), a British intelligence agency whose mission was to advise on safety codes and ciphers used by the government , and also study communication methods used by other countries encrypted.

World War II would begin next year, and Turing played a vital role in the agency while working to decipher the codes used by the Germans during the war goes communicate. Particularly focused on Enigma, a machine used by the Germans, were summarized and deciphering secret messages in Morse code, and whose understanding allowed the Allies to know in advance the enemy's plans.

Turing worked with experienced Dilly Knox in the GCCS to improve the method made by Poland to read the messages, which led to the creation of bombe, a machine whose function was to discover the configuration of the Enigma machines used in German networks for can then find the key that would read the message.

During the war, Turing also provided to address other encryption systems used by the Nazis, especially the version of Enigma used by the German Navy, which was more complex than using the other branches. This led to a special unit known as "Hut 8".

In many cases, improved way to figure that already existed. The mathematician employed several statistical techniques to optimize test different alternatives in the process of deciphering a code.

Turing wrote two papers about it that were considered so valuable by the GCCS and sucessora, GCHQ, which were not made public until April this year.

During his tenure with this agency, Turing earned a reputation as an eccentric. For example, I had a bicycle to which the chain was coming out every few pedal strokes. Rather than repaired, Turing had the amount of pedaling and wearing down just in time to adjust the chain before they leave. It also says he used to tie his bowl to the heating pipes to avoid being stolen.

End of war and artificial intelligence

After the war, Turing moved to Richmond, London, where he worked on the design of "Computational Motor Auto" or ACE, the National Physical Laboratory. In 1946 he presented a paper which detailed the first detailed design of a computer program stored, ie, instructions for a program stored in an electronic memory. Although the proposed design was possible to manufacture, the amount of secrets after the war had delayed the implementation of the project and finally Turing left him.

In late 1947, the mathematician took a sabbatical and returned to Cambridge. While outside, he built the first ACE, which ran its first program on May 10, 1950. Although the ACE model proposed by Turing was never built, his ideas led to machines like the English Electric DEUCE and the Bendix G-15 years later.

In 1948, Turing began working in the Department of Mathematics, University of Manchester, where he did further research in abstract mathematics, coming little by little in the field of artificial intelligence.

Turing proposed in 1950 a test called the "Turing Test", which attempts to define a standard for a machine can be considered "smart." The idea was to put a human to examine a machine. If humans could not make out, through conversation, if your partner was human or machine, it was concluded that the computer was able to think.

In his paper, Turing proposed that instead of creating a program that simulates an adult mind, which would have to do is create a simpler, you can simulate a child's mind, and then "educate".

A few years before considering this, Turing had started to develop a chess program to run it on a computer - that did not exist. In 1952, the absence of any machine powerful enough to run the program that had been raised, simulating the Turing played chess computer, taking half an hour for each move on the board. The program lost to Turing's friend, Alick Glennie.

Homosexuality and later years

Turing worked from 1952 until his death in mathematical biology and morphogenesis, the mechanism by which an organism gets its way. Of particular interest was the existence of Fibonacci numbers to the structure of the plants.

Although Turing had admitted his homosexuality in times of war, was in the 50's that brought sexual orientation issues. In January 1952, Turing met Arnold Murray at the exit of a cinema in Manchester, with whom he began dating. Murray, however, took advantage of Turing confidence to enter your house to steal a few weeks. Turing reported the crime to the police, and during the investigation, admitted a sexual relationship with Murray.

Homosexual acts were illegal in the UK at the time, so both were convicted of "gross indecency". The punishment options were being caught, or undergo chemical castration on probation. Turing chose the latter alternative.

Having been convicted of a "crime" was forbidden to continue the consulting unit performed in the cryptanalysis of the British intelligence agency.

On June 8, 1954, Turing was found dead in his home. It was determined that the cause of death was cyanide poisoning. His body was found next to an apple bite, and although not reviewed the apple, is believed to have ingested the poison through the fruit. According to novelist David Levitt, Turing's favorite story was Snow White, so it may have reproduced the scene of the apple in his suicide.

It is not clear why it took this decision. It may have been police surveillance, or maybe something else. Chemical castration is considered one of the possible reasons. In 2009 he launched a petition to the British government to apologize for his treatment mathematician.

"Thousands of people have come together to demand justice for Alan Turing and recognition of the shameful way he was treated. While Turing was tried by the law of time and can not turn back the clocks, the deal was completely unfair and I am glad to have the opportunity to say how deeply sorry I and all what happened. So, on behalf of the British government and all those who live freely thanks to the work of Alan, I am very proud to say: sorry, deserved so much better, "wrote the Prime Minister, Gordon Brown this year.

In 2011 there was a request that he "forgive" his crime, however, the request was rejected. Lord McNally said at the time that "the law of his time called for a condemnation, and as such, the long-term policy has been to accept that these convictions occurred, instead of trying to alter the historical context to correct what can not be corrected we must ensure we never will those times again. "

Turing was honored by several universities and received several awards and posthumous tributes. This year there are also many celebrations for the centenary of his birth, not only in the United States but also in the U.S., Germany, Brazil, Spain, New Zealand and other countries.

Last year also produced a TV movie in the UK, we leave the trailer:


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