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Alan Turing a hundred years

If you are a student of computer science a chance to know who was Alan Turing. This year marks the centenary of Turing, who is the 100th anniversary of his birth. Because computers are everywhere these devices today, I believe that every computer user should know who Alan Turing.

It is often considered the father of computer science. But it would be more correct to say that the grandfather of Informatics Turing, John von Neumann, like his father. So I write a few words about John von Neumann, as well.

Alan Mathison Turing invented the Turing machine in 1930, which is an abstract model of a modern computer than a real computer was built in the 20th century. Turing machine is built only on paper (as a mathematical formula), and it was a preliminary theoretical step that allows the construction of the first universal electronic computer, ENIAC in 1946.

One of the deepest of his success is "the principle of a universal machine, which makes sense, and do not count is a driving machine," writes University of Oxford Andrew Hodges. Turing also defined the concept of computability, which is still very important for science.

"What is a Turing machine?" You ask. This is an abstract machine and has the exact mathematical definition, which I write here. Imagine that you have a black box with two adjacent bands. One is the input tape and other tapes used for the calculation (the computer must be able to count, right?). We have lots of input characters allowed (examples of all the letters of the alphabet in English, if only the digits 0 and 1). So write the input string on the tape input. Turing machine is able to read each character entry, one by one. Allowed to be read (input) as many times as needed, to and fro.

Now the tape is very long, in fact, imagine that to be infinite. (The tape input is finite.) The machine also has the condition. It is a black box (do not know anything about its content), but at any time the box is in the state. As a door that can be open or closed, or traffic lights, which can be red, yellow or green. The number of possible states of a Turing machine is limited.

Imagine also that somewhere inside the black box is a set of equipment used for the calculations. (.. As you can see, the device is calculated by means of symbols, not numbers, but it is like algebra, where you can count using the letters and numbers) Each rule says that something like this: If the state machine to enter and if the machine is simply sign reading then writing the character of infinite strip and the print head to move one cell to the left.

I must add that each team is divided into "cells", and each cell can contain only one character or no character at all. In the beginning, after the endless band of cells that do not contain any characters, and points to the record head first cell of an infinite tape. It can also delete the character to the printhead in the cell, which is now addressed. It is. The device reads a row of characters, the existing rule, and then writes the character of the endless tape and writing skills to go head first cell to the left or right one cell. Then repeat the type of "Step" many times. This may eventually stop or it can work forever. Calculation result is a string of characters that are on the endless belt when the machine stops.

Does it sound complicated? I mean, I agree. However, the actual computer is even more complicated! Now the coolest Turing machines is that they can count as a real computer calculated (it can take much more time to this work.)

Also, Turing, who was born on June 23, 1912, at the head of the British war effort to break the German encryption codes. Although it was an outstanding scientist, was convicted of crimes related to homosexuality in 1950 and committed suicide two years later. In 2009 he was awarded the then British Prime Minister Gordon Brown's official apology, but the grace was rejected on the grounds that he had been convicted of anything at the time was considered a crime.

As I mentioned, John von Neumann, let me write a few words about his contribution to science. John von Neumann was a great mathematician of the most important contributions to science. It is known (among other scientific contributions) "von Neumann architecture", which is essentially the same architecture of modern computers. In 1948-1949, he was heard on the program of the ENIAC and EDVAC computers, the first stored program computer. This means that the computer where the data and how the program stored in computer memory. He actually invented a modified set of instructions for the ENIAC computer.

Although John von Neumann was older than Alan Turing, von Neumann is in relation to the work of Turing in his "computer and the brain," was published posthumously:

"English logician AM Turing showed in 1937 (and many experts calculating machines put into practice a number of specific ways), it is possible to develop a computerized code machine instructions, causing it to behave as if nothing specified, computing machine."

John von Neumann was born in 1903 and died of bone cancer in 1957. Both von Neumann and Turing is one of the pioneers of computer science. We owe them all the great amenities computers, whether desktop, notebook, PC or Mac.
 
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