# Double Pi, What Does This Mean?

Happy $\tau$-day folks. What exactly is $\tau$? you ask. Well, $\tau$ is a greek letter. But it also happens to represent the mathematical constant $2\pi$. And why do we care about that? Well it turns out that some math-lovers think that instead of teaching students about $\pi$, we should focus on the number $\tau$. You see, while $\pi$ is ubiquitous, it is often accompanied by the number 2. As in $2\pi$. As in $\tau$.

Anyway, the arguments for the use of $\tau$ are quite valid from a pedagogical perspective. I won’t get into them, as they are all explained quite nicely here. Of course, standard practice is to teach students about $\pi$. Is one better than the other? Perhaps. To be honest, I think the debate is entertaining in and of itself. And any conversation that gets people thinking about math makes me happy.

Given that it is $\tau$ day, you might wonder how best to celebrate. Well, since $\tau=2\pi$, and $\pi$-day demands the consumption of pie or pie related foods (pizza pie, for example), clearly $\tau$-day demands, yes demands, that you consume twice as much pie as you would on $\pi$-day. And any day that recommends the consumption of pie can’t be bad, right?

Another note of interest: Today’s date – June 28, or 6/28 was selected for $\tau$-day because $2\pi\approx 6.28$. Even better, 6 and 28 are the first two perfect numbers.  That means that 6/28 is actually a perfect day, which makes celebrating $\tau$-day even that much better!

Happy perfect $\tau$-day all y’all. Now go hug a nerd.