March 14 is Pi (π) Day, when we celebrate this important never-ending number. Pi is the circumference of a circle divided by its diameter—or 3.14159… and on, and on.

Pi is key in everything from sending spacecraft to other planets, to designing buildings, to calculating how much (actual) pie each person gets for dessert!

But did you know that the story of how Pi Day came about is as exciting as the math itself?

### The Prince of Pi

Back in 1988, the San Francisco Exploratorium museum’s former staff physicist and media specialist Larry Shaw linked March 14 (3/14) with the digits of pi.

So on that very first Pi Day, at 1:59 pm (1, 5, 9 being the pi numbers that follow 3.14) Larry and his wife, Catherine, set up a table on the museum's floor topped with fruit pies and tea.

Then a few years later, Larry's daughter, Sara, realized that Pi Day was also Albert Einstein's birthday, so a celebration of his life was added to the Pi Day festivities.

### Around and around... 3.14 times

Larry created and installed the "Pi Shrine" at the museum: a circular brass plaque, in the centre of a circular classroom.

Each Pi Day, with his boombox blaring the digits of pi to the music of "Pomp and Circumstance", Larry would lead a parade of pi enthusiasts around the outside of the museum several times… 3.14 times, to be exact!

Larry, who became known as the Prince of Pi, passed away in 2017, but we think he’d be thrilled that the Pi Day celebrations around the world continue to excite people of all ages.

Happy Pi Day!