Attention, geeks: Your favorite holiday has circled back again. It’s not Star Wars day (May 4). Nor is it Marty McFly Day (October 21). And it’s not Talk Like a Pirate Day either, matey (September 9). It’s Pi Day — which also coincides with Einstein's birthday.

For the math-challenged among us, Pi is the number you get when you divide the circumference of a circle by its diameter, or roughly 3.14. Why are we celebrating a number? The holiday was invented by Larry Shaw, a physicist (surprise) who commemorated the day by eating pies and marching around in circles. In 2009, Congress made the holiday official, in an attempt to encourage kids to learn about Pi and study math. So cut yourself a wedge of your favorite crust-lined circular pastry and check out common references to Pi.

## Happy Birthday, Albert Einstein

If you want to celebrate the day like an ivy-leaguer, lace up your Sperry topsiders and head down the Garden State Parkway to Princeton, New Jersey where the college town pulls out all the stops to commemorate the birthday of Albert Einstein (who lived in Princeton for over 20 years). Events include a Pi recitation contest, a pie eating contest, and an Einstein look-a-like contest.

## Good or Evil?

In Carl Sagan’s 1985 book, *Contact*, the protagonist Ellie finds a hidden message encoded in Pi. According to the story, the message comes from man’s creators. While the book ends by implying that God had left a message for humanity, numerologist naysayers are fond to point out a more sinister pattern: The first 144 digits of Pi add up to 666, which often is referred to as “the mark of the Beast”.

## Sure, it’s infinite, but how does it smell?

In 1988, Givenchy released a men’s cologne named Pi. According to the luxury French brand, Pi emits a fresh scent of patchouli and sandalwood and its recommended use is, simply, *evening*. “Pi is a celebration of what makes a man seductive — his intelligence, courage, and contributions,” they say. “Pi is more than a name, it's a symbol.” Indeed it is.

## Pi in the 2020 Olympics?

In 2008, a new sport emerged from South Africa. Inspired by Pi, it instantly joined such illustrious pursuits as quidditch and Parrises Squares. Pi Ball is played on a circular court and looks a lot like beach volleyball without the net, sand, or bikinis. Racquets are used, and based on this video there’s a fair bit of head butting. On second thought, maybe it’s not like beach volleyball at all.

## Would you like some OJ with your pie?

It should come as no surprise that the best mathematical constant ever made an appearance at the Trial of the Century. During OJ Simpson’s murder defense, justice took a back seat to some good old high school mathematics. Here’s the comic and error-ridden exchange between OJ Simpson’s attorney, Robert Blasier and FBI agent, Roger Martz:

MR. BLASIER: Well, what is the formula for the area of a circle?

MR. MARTZ: Pi r squared.

MR. BLASIER: What is pi?

MR. MARTZ: Boy, you are really testing me. 2.12, 2.17.

THE COURT: How about 3.12.14.

MR. BLASIER: Isn't pi kind of essential to being a scientist knowing what it is?

MR. MARTZ: I haven't used pi since I guess I was in high school.

MR. BLASIER: Let's try 3.12.

MR. MARTZ: Is that what it is? There is an easier way to do--

MR. BLASIER: Let's try 3.14. And what is the radius?

MR. MARTZ: It would be half the diameter, 2.5.

MR. BLASIER: 2.5 squared, right?

MR. MARTZ: Right.

MR. BLASIER: Your Honor, may we borrow a calculator?