That’s right, its *τ* Day! Wait, what?

Recently, I have found an interesting proposal regarding the number* π* (the ratio of the circumference of a circle to the diameter, or, 3.14159265358979…and so on…). It states that using *π* is not the best choice and that we should use a constant that is equal to 2*π*, which is 6.283185307179586…and so on… Basically, the ratio between the circumference of a circle to it *radius* is more basic a concept than circumference to diameter.

So what’s the difference? Well the main point is that in almost every single equation that you encounter in math and physics that comes with a *π* in it, it actually comes as 2*π* or some multiple thereof. Therefore, it is more convenient to simply write *τ* (called “tau”), one character, than 2*π*, which is two characters. Physicists like to simplify things as much as possible when they can.

Therefore *τ* Day is 6/28, which is today!

There are other reasons too. Conceptually, it is more intuitive. Travelling *τ* radians takes you once around a circle. Travelling *τ/*2 radians takes you halfway. One tenth of a circle is *τ/*10, and so on. For *π*, the values would be 2*π*, *π*, and *π*/5, which don’t really make sense. Travelling *π*/5 takes you a *tenth* of the way around a circle, rather than a *fifth*?

Anyway, I love it, and maybe I’ll try to use it on some test and see what happens (initially noting that *τ* = 2*π*, of course).