**Tau and radians: the perfect match**

In a previous post, I introduced an animation explaining radians. It used π (pi), the standard constant used to measure circles.

However, as I mentioned in that post, there’s an ongoing movement to promote the constant τ (tau) to be used instead. When dealing with radians, tau makes undeniably a lot more sense than pi: a quarter tau radians represents, precisely, a quarter of a full rotation around the circle. With pi, a quarter rotation is π/2. That’s just nonsense!

**EDIT:** here’s a long post where I detail my thoughts on the pi vs. tau discussion.

Quite a few people demanded a version of the animation with tau, though they didn’t even have to ask. I was already planning on making one!

Just as before, Tumblr forced me to get rid of a lot of the frames, so the animation here isn’t as smooth as it could be. Here’s the proper animation (click to go to the Wikimedia Commons details page).