It's Pi Day today! What's happening at 1:59 PM sharp on March 14?

March 14 is the day when math and food amalgamate, thanks to Pi Day. While lovers of the subject mark the day by celebrating the mathematical constant, fond eaters use it as a valid excuse to devour delicious pies. Pi Day aims to recognise the importance of the irrational number, which is used in everyday life, whether it is to calculate distances in navigation, or measure circles and spheres. 

Pi Day is a big pun in itself. It is celebrated annually on March 14 or 3/14, as the numbers 3, 1, and 4 are the first three digits in pi. But the highlight of the day is when the clock strikes 1:59 PM, as the numbers make up the rest of the digits in the value of pi, that is 3.14159. 

Pi Day is believed to have started in 1988 at the San Francisco Exploratorium, but it was only officially recognised by the US House of Representatives in 2009 as part of a resolution. Since then, the day has served as a celebration for students, educators, and math enthusiasts. The day is marked through various activities, such as competitions, lectures and pie-eating contests.

NASA marks Pi Day with nerdy challenge

What intrigues intellectuals about the mathematical constant is no matter how massive or miniscule a circle is, from a planet to an atom, the ratio of a circle's circumference and its diameter is always equal to pi. Space agency NASA also observes the day by organising quizzes, puzzles and challenges related to actual space missions. 

This is because the Greek mathematical figure is vital in NASA's missions of unraveling the mysteries of Earth and other planets in space. "Space is full of circular and spherical features, and to explore them, engineers at NASA build spacecraft that make elliptical orbits and guzzle fuel from cylindrical fuel tanks, and measure distances on circular wheels. Beyond measurements and space travel, pi is used to find out what planets are made of and how deep alien oceans are, and to study newly discovered worlds," NASA said on its website.

This year's Pi Day marks a decade since NASA’s Jet Propulsion Laboratory first celebrated the occasion with a Pi Day Challenge. The challenge encourages students to push their mathematical mettle, but it also offers an array of resources for teachers and parents, such as articles, posters, illustrations and lessons.