Many things in this world are a matter of perspective. Often, those things can stimulate conflict and polarization. But constants are the same, no matter who we are or how we look at the world.

There are a slew of scientific constants. The ideal gas constant (R), the gravitational constant (G), and of course the speed of light (c), to name a few. And while these constants are the same for everyone, they sometimes appear different because empirical units like length and time are measured differently in different places. We could not broadcast 3.0×10^8m/s into outer space and hope that it could be understood by an alien being on a distant planet.

But we could broadcast τ (tau), the ratio of a circle’s circumference to it’s radius.  No matter where you are in the universe or what kind of measurement system you’re using, you will come up with 6.283185… for τ.

Okay, okay, there is some translation necessary. If you’re an alien you’re probably not going to have ten fingers, so you probably are using binary (τ = 110.01001…) or base twelve (τ = 6.339416…) or something (and yes, I did geek out and calculate those by hand). Anyway, my point is that τ is the same ratio however you look at it. There are some truths we all have in common no matter how big our differences seem sometimes. Happy tau day everyone!

(If you still think that π is the proper circle constant, check out tauday.com or Vi Hart’s lovely video on the topic)