Google has dedicated a doodle to mark 30 years of "Pi Day", a day first recognised by physicist Larry Shaw in 1988 to honour the mathematical constant.
Observers often celebrate the day with a slice of their favorite sweet pie to compliment the Greek letter's "delicious sounding name."
π is very significant in mathematics, especially geometry. It is the ratio between a circle's circumference to it's diameter. Without Pi it wouldn't be possible to calculate the area of circle, A=πr².
Pi is an irrational number that extends to infinity, but is approximately equal to 3.14 (hence celebrated on the 14th day of the third month) or 22/7. The Greek Mathematician Archimedes first approximated Pi as roughly 3.14. Pi is also celebrated by some on July 22 (22/7) instead of today and it's called Pi Approximation Day.
Pi is useful in every field of science as it's used for calculations involving the volume and surface area of spheres, as well as for determining the rotations of circular objects such as wheels. Scientists working with planetary bodies and spacecraft thus cannot do without Pi.
Historically, the first Pi Day was held at a San Francisco Science Museum in 1988 when the physicist looked at the calendar and decided to pay homage to the mathematical entity. It was however, William Jones, a mathematician from Wales, who first gave the Greek letter its current mathematical definition.
Fun fact! March 14 is the birthday of physicist Albert Einstein. It is also the birthday of Apollo 8 Commander Frank Borman, astronomer Giovanni Schiaparelli, and last-man-on-the-Moon Gene Cernan.
