Pi

Pi is a mathematical ratio. It is represented by a Greek Letter, . Pi is approximately 3.14. Pi is the number of times that a circles diameter will fit around the circle. There are an infinite number of digits. It is an irrational number, which means that it cannot be written as the ratio of two integer numbers. It has been calculated to two billion two hundred sixty million three hundred twenty one thousand three hundred sixty three digits (2,260,321,363) by the Chudnovsky brothers in 1991.

Pi can be dated back to the middle kingdom on a papyrus scroll written in about 1650 B.C. by a scribe named Ahmes. He finds the area of a circle using an irregular sort of pi. Around 200 B.C. a Greek mathematician named Archimedes found that Pi was between 3 10/70 and 3 10/71. Ptolemy was the next researcher. In 150 AD, he calculated pi to 3.1416. In 480, Zu Chongzhi calculated pi to seven decimal places. In 1665, Isaac Newton calculated it to 16 places. In the 17th century pi began being called the Ludolphian number after Ludolph van Ceulen, a German mathematician. He calculated pi to 35 places. The first person to use the Greek letter was a Welsh mathematician William Jones, in 1706.

People use pi everyday to solve mathematical equations. It is the most recognized mathematical symbol in the world. In 2002, a team of mathematicians calculated pi to 1.2411 trillion digits, over six times their previous calculation in 1999. Now to celebrate the discovery and use of pi we have pi day. Pi day is celebrated all over the world by math classes and nerds on March 14.

References

Ludolph van Ceulen. (n.d.). Retrieved February 3, 2007, from http://www.angelfire.com/id/vancuren/ludolph.html

O'Connor, J. J., & Robertson, E. (2001, August). A History of Pi. Retrieved February 3, 2007, from http://www-history.mcs.st-andrews.ac.uk/HistTopics/Pi_through_the_ages.html