Pi Day - Half Tau Day? | The Mary Sue

### Happy Pi Day! (Or Is That Half Tau Day?)

By geek tradition, 3/14 is widely celebrated as Pi Day, because, well 3.14 and all of that. Hardly just the mathematical constant used to define various key properties of circles, pi is symbolic of the enigmatic power of math. The symbol is teasingly simple, yet the number goes on forever; truly, a most poetic idea. And it sounds like “pie,” and everybody loves pie. OK, we’ll admit it: A big part of Pi Day’s appeal is that geeks want to stuff themselves with baked goods, but hey, you deserve it.

Here’s the thing: Though everyone likes pie, not everyone likes pi. Vi Hart, whose work we’ve featured in the past, is one such person: In the video above, she allies herself with tau (τ), the mathematical constant defined as 2π. For reasons outlined in the video, Hart and tau proponents (Tauists?) argue that if history and schools had worked together to ensure that tau rather than pi was adopted as the circle constant of choice, math education would be a lot less confusing and many equations would look much more elegant.

All fascinating stuff, but if that sounds a little dry, Hart bakes two delicious pies in the video, so we all win.

(via TDW)