Ta' bom, eu sei que foi ontem, but... what the hell... (thx to Deepak Punjabi )
July 22 - Pi Approximation Day Pi Approximation Day is celebrated on July 22, because of the Ancient Greek mathematician Archimedes' first rough approximation of Pi (p) as being 22/7. --------------- Happy Pi Approximation Day! By Rene Sance Published: July 22, 2009 Pi, as everyone but samuraipandapoetry will recall, is the ratio between a circle’s circumference and its diameter. If the diameter of a circle is 1, than its circumference is π. Its value is traditionally represented as 3.14159… Some people celebrate the 22nd of July for its approximation of π (22/7). Others celebrate March 14 (3.14), although the deluded followers of the March date refer to it simply as Pi Day. But all values for π are approximations, because π is irrational. The ancients did not know this - and it wasn’t finally proven until the 18th century - but π cannot be expressed as any exact fraction. (This despite the Indiana House of Representatives passing a law stating that π = 3.2.) Pi extends forever and ever, and where π goes, its devotees follow. A major breakthrough for calculating π came with the invention of electronic computers and yet more efficient algorithms. Suddenly, thousands of digits were being calculated, and records were being overturned more and more rapidly. In 1973, 1 million decimal places of π were computed. By the 1980s, records of 16 million and then over 201 million digits had been set. In 1989, David and Gregory Chudnovsky found 480 million digits using a home supercomputer they custom built from off-the-shelf parts that took up most of their apartment. Later that year, they reached 1 billion digits. When a competitor reached 6 billion digits 6 years later, the Chudnovskys turned around and attained 8 billion digits the year after that. In 1997, a Japanese team calculated 51.5 billion digits of π. The same team set the current record of just over 1 trillion digits. Make no mistake: 30 decimal places would suffice to measure a circle the size of the observable universe to within the width of an atom. Calculating decimal places beyond that has no practical value. The strenuous, sometimes life-long exertions of number theorists throughout history to eke out the next digit of π, and then the one after that, have served the goal of finding patterns in the unending river of numbers. The mystery is the message. But as far as anyone has been able to determine, the digits are more or less random. Deepak Punjabi -- [ ]'s Claudiß
