What is the pi number and what is its history

One of the most mysterious numbers knownhumanity, of course, is the number Π (read - pi). In algebra, this number reflects the value of the ratio of the length of the circle and its diameter. Previously, this value was called the ludolph number. How and where the number Pi came from is not known for sure, but mathematicians divide into 3 stages the whole history of the number Π, the ancient, classical and the era of digital computers.

The number Π is irrational, that is, it can not berepresent in the form of a simple fraction, where the numerator and denominator are integers. Therefore, such a number has no end and is periodic. The irrationality of II was first proved by Lambert in 1761.

In addition to this property, the number Π can not beand also the root of some polynomial, and therefore is a transcendental number. This property, when it was proved in 1882, put an end to the almost sacred debate of mathematicians "about the quadrature of the circle," which lasted for 2,500 years.

It is known that Briton Jones first introduced the designation of this number in 1706. After the works of Euler appeared, the use of such a designation became generally accepted.

In order to understand in detail what the Pi number is,it should be said that its use is so wide that it is difficult even to name the field of science in which it is dispensed with. One of the simplest and most familiar from the school's program of values ​​is the designation of the geometric period. The ratio of the length of the circle to the length of its diameter is constant and is equal to 3, 14. This value was known even to the oldest mathematicians in India, Greece, Babylon, Egypt. The earliest version of calculating the ratio refers to the year 1900 BC. e. The Chinese scientist Liu Hui has calculated the value of P more close to modern, in addition, he also invented a quick way of such calculation. Its magnitude remained generally accepted for almost 900 years.

The classical period of mathematicswas marked by the fact that in order to establish exactly what the Pi number is, scientists began to use methods of mathematical analysis. In the 1400s, the Indian mathematician Madhava used the theory of series to calculate and determined the period of the number P with an accuracy of 11 digits after the decimal point. The first European, after Archimedes, who researched the number P and made a significant contribution to its justification, was the Dutchman Ludolf van Zeilen, who had already determined 15 digits after the decimal point, and in the will wrote very entertaining words: "... who cares - let him go on." It was in honor of this scientist, the number P, that got its first and only name in its entire history.

The era of computer computing has brought newdetails in understanding the essence of the number P. So, in order to find out what the Pi number is, in 1949 the ENIAC computer was used for the first time, one of the developers of which was the future "father" of the theory of modern computers, J. von Neumann. The first measurement was carried out for 70 hours and gave 2037 digits after the decimal point in the period of the number P. A mark of one million signs was reached in 1973. In addition, during this period, other formulas reflecting the number of P. were also established. Thus, the Chudnovsky brothers were able to find one that allowed to calculate 1 011 196 691 figures of the period.

In general, it should be noted that in order to respond tothe question: "What is the Pi number?", many studies began to resemble competitions. Today, supercomputers are already working on the question of what it really is, the Pi number. interesting facts associated with these studies, permeate almost the entire history of mathematics.

Today, for example, the world championships are heldto memorize the number of P and record world records, the latter belongs to the Chinese Liu Ciao, for a day with a little, called 67,890 characters. In the world there is even a holiday of the number P, which is celebrated on March 14 as "Day of the Pi number".

As of 2011, there are already 10 trillion digits of the period of the number.