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Pi Day 2014: Brief history of pi, origins of the numerical geek holiday

Pi = 3.1415926535... Pi Day is celebrated by math enthusiasts around the world on March 14th
Pi = 3.1415926535... Pi Day is celebrated by math enthusiasts around the world on March 14th
Flickr/J.Gabás Esteban

Happy Pi Day! Geeks all over the world celebrate the mathematical constant 3.14 on 3/14 or today, March 14. "Pi" is represented by the Greek letter "π", the symbol Mathematicians commonly use to represent the ratio of a circle's circumference to its diameter. You know, “π times radius squared” ?

According to the SFGate, the first known celebration of the “geek holiday” Pi Day was in 1988 at the San Francisco Exploratorium, created by physicists Larry Shaw and Ron Hipschman. As USA Today reports (March 14), the practice became official in the U.S. when the House of Representatives designated March 14 as “Pi Day” in 2009. Pi Day "encourages schools and educators to observe the day with appropriate activities that teach students about Pi and engage them about the study of mathematics," reads House resolution 224.

Math enthusiasts participate in Pi Day activities by sharing Pi Day jokes, wearing Pi Day t-shirts or buttons, singing Pi Day songs, throwing a Pi Day party (substituting cake with pie) and wish each other "Happy Pi Day" with a lovely Pi Day e-card.

The use of the numerical value of Pi traces back to ancient times in written references of Egypt. During the building of the Great Pyramid at Giza in 2589-2566 BC, Egyptians may have used Pi to calculate measurements. The linear measurements consist of a 1760 cubit perimeter and a height of 280 cubits. The ratio is approximately equal to 2π (1760/280= 6.2857), suggesting that Egyptians designed the pyramid based on a circle.

In this era, we are familiar with the irrational number Pi as a tool for solving trigonometry and geometry problems. Pi is also used in other sciences, including cosmology, statistics, thermodynamics and mechanics.Although its numerical value consists of an infinitely repeating decimal, no more than 40 Pi digits are usually required for scientific applications. If you want to impress people, you really only need to recite the first twelve digits.