SciTech Tuesday: A Celebration of Pi

Thursday March 14 marks Pi Day, a celebration of all things circular.  Pi is a mathematical constant represented by the Greek letter “π.”  The ratio of the circumference of a circle to its diameter, π is an irrational number and as a consequence its decimal series does not end nor does it form a repeating pattern.  Through the use of novel mathematical approaches paired with new computing capabilities, the decimal representation of π extends to over 10 trillion digits.  However, most scientific calculations require far fewer digits.   NASA, for example, uses 16 digits of π in calculations related to spacecraft control and navigation.  That is 3.141592653589793.

π is used to calculate the area and volume of geometric shapes based on circles, including spheres, cylinders, cones, and ellipses.  In trigonometry π aids mathematicians in measuring angles in radians.  Beyond mathematics π is applied to a variety of formulae in the fields of electromagnetism, statistics, physics, quantum mechanics, engineering, and geology.  π can be used to represent DNA’s double helix, the curvature of the human eye, the arc of a rainbow, and the trajectory of a rocket.  π is used by many people, from a quantum physicist measuring the position of an atomic particle to a middle school student building and programming a robot.

Albert Einstein’s birthday is also March 14, adding extra significance to Pi Day.  Einstein used π to confirm that the gravity of the sun could bend light rays of stars millions of miles away from the earth.   General relativity made him an instant hero as news emerged of his new theory of gravity, the first since Sir Isaac Newton over 250 years earlier.  Einstein used his celebrity 20 years later when he signed the letter written by fellow physicist, Leó Szilárd, advising President Roosevelt to fund research investigating nuclear fission, later becoming the Manhattan Project.

The first recognized Pi Day took place in 1988 at the San Francisco Exploratorium culminating with celebrants feasting on fruit pies.  In 2009 the U.S. House of Representatives designated March 14 to be National Pi Day.  How will you celebrate Pi Day?

Post by Annie Tête, STEM Education Coordinator

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