For some math enthusiasts, June 28th is Tau Day (τ), not to be confused with the day honoring the value of Pi (π). What the heck is tau? To some, tau (2π or approximately 6.28) is the mortal enemy of pi (approximately 3.14). Tau Day is a holiday for certain rebel mathematicians to spread awareness of tau as the rightful heir to the throne in which pi sits.

As we learned in grade school, pi is the ratio of circumference to a diameter of a circle. Tau, on the other hand, is the circumference divided by radius. Revellers of tau argue that pi is the wrong figure to be associated with the properties of a circle, which is more naturally defined by radius and not diameter. Therefore, pi, an essential in equations in math, science and engineering, should be replaced by tau. Get it?

Observers of this numerical holiday spend June 28th speaking out in the name of tau, posting on relevant blogs, sharing poems, comics, animated gifs and even the occasional music video across the social interweb. Don’t believe me? Check out the hashtag #tauday on Google+ or Twitter and see for yourself. The end goal: to displace pi (π) with tau (2π) in hopes of clarifying equations for the greater good of society. Some believe this could even simplify the teaching of calculus, for which I am onboard!

With all the war in the world, you’d think the two values would learn to get along. After all, they aren’t all that different from one another. Both consist of an infinite amount of post-decimal digits, making memorization impossible. Go ahead, try it. Despite similarities, it’s clear that the math world, which values precision and exactness, are only becoming further divided (math joke!) on the issue as the Tauist (yes, that is what they call themselves) populations seems to grow bigger and louder each year.

Do you believe the pi is a lie? If so, join the movement! Below are some excellent ways to ring in Tau Day 2014:

- Spread the tao of tau across social media (hashtag: #tauday)
- 2 words: Tau tattoo! (τ)
- Form a circle (relevant shape!) and take turns reading passages from “The Tau Manifesto” written by the world’s leading anti-pi propagandist, Michael Hartl.
- Need more Hartl in your life? Grab some popcorn and watch the video of Hartl as he passionate explains the “centuries-old conspiracy to propagate pro-pi propaganda.”
- Our favorite celebratory activity: eat TWICE as many pies as you normally would, on say, Pi day!

We want to know how you’re celebrating Tau Day 2014. Include +Backupify or @Backupify in your #TauDay posts and we will share our favorites on our Google+ page.

Whether you are on Team Tau or Team Pi, we hope you enjoy the day.