# Today Marks Century's Most Epic Pi Day

Lisa Fogarty

Math nerds, unite! It's the happiest day of the year for us: it's Pi Day! But today, March 14, 2015, marks an even more epic-than-usual Pi Day—a once in a century celebration!

Pi is an irrational number (meaning, it never ends and doesn't follow a pattern) that represents the ratio of a circle's circumference to its diameter. You may remember teachers drilling this into your head: Pi equals 3.14. But that whole bit about it being a neverending irrational number also means there are a slew of numbers that come after the ".14" that your teacher was kind enough not to force you to memorize.

Pi actually equals 3.141592653 (and it goes on for about a trillion more numbers after the decimal point, though mathematicians say you really only need 39 decimal places). All we need to know for today's celebratory purposes is this: the date is 3/14/15. Pi = 3.1415. Trippy!

Also, the coolest part of the day has already passed, but you have a second chance to commemorate it again tonight when the clock strikes 9:26:53.

Don't laugh—this is exciting stuff!

More from The Stir: Happy Pi Day! Celebrate With 8 Delicious 10-Minute Pies (PHOTOS)

If you're curious as to how you should party today, here are a few suggestions. You can bake and eat an actual pie. You can watch these amazing children recite Pi digits while doing things like balancing books on their heads. Or you can grab a bunch of books and hide in your room because you were an English major and just want this day to pass as quickly as possible.

Are you celebrating Pi Day?

Image via Robert Couse-Baker/Flickr