The Value of Pi

As most every seventh grader knows, pi is a value that gives a ratio between the diameter and circumference of a circle. They also know it is a transcendental number, like e, the base value of natural logarithms. It is also irrational, which means that, so far, it has a non-repeating sequence of digits to the right of the decimal place. Most use an approximation appropriate to the complexity of the work involved, such as the very simple 22/7 or, for many 3.14159. But we all know that the 9 is far from the last digit that can be calculated.

Π  – such a funny little symbol, yet so important.

In the category of things we never thought we’d want to know, the value has just been calculated to 2.5 trillion (yes, that is 11 zeros to the right of the five, with the decimal moved to the right of the rightmost zero) places, by means of a Japanese supercomputer.

from the

The T2K Open Supercomputer, located at the University of Tsukuba’s Center for Computational Sciences, reaching 2,576,980,377,524 decimals in an approximately 73 hours and 36 minutes long calculation, according to an announcement made to the Japanese press on August 17th. The Center said it was in the process of applying for the record book.

The new number more than doubles the previous record of around 1.2 trillion digits set in 2002 by the Kanada Lab at the University of Tokyo. It is also more than 12 times the record set in 1999, again by the Kanada Lab.

The T2K, capable of doing 95 teraflops (essentially 95 trillion calculations per second), is said to be the 47th most powerful supercomputer in the world and 6th in Japan, according to a June 2009 report by

I don’t know about you, but I do think it is good that people work on these things, as the extension of knowledge is always a good thing.

Oh, there is, after all that calculation, still no repeating pattern of digits.


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