Tau Day is here: celebrate tau, not pi, as the true circle constant

You’re likely familiar with Pi Day, perhaps the most popular of geeky holidays. Hooray. But I’m here to tell you that Pi Day is wrong — or rather, the entire idea of pi as a mathematical concept is wrong, and why you should be celebrating Tau Day, instead (which happens to be today!)
It’s easy enough to see why people like Pi Day: the whole thing starts with a mathematical pun of sorts (The date is written as 3/14 in American notation. Pi starts with the digits 3.14. You