# The Life of Tau

This year’s March 14 marked another much anticipated Pi Day!

When kids are still in their early teenage years, struggling through middle school math classes, they are introduced to the idea of pi. Everyone learns the formula π=C/d, which means pi is equal to a circles circumference divided by its diameter. This is why pi is known as the circle constant. However, what if there is a better way? What if everyone has been deceived?

In 2010, Michael Hartl started Tau day to promote the idea of using Tau as the new circle constant. Essentially, Tau is just double pi, or 6.283. So, the question arises; what’s the point? Many mathematicians agree that Tau is actually much more useful when looking at its application in math due to the fact that typically we do not examine circles diameter but instead we look at their radius. When Tau is used in a circle equation it is represented as t=C/r which is a much more natural constant to work with. The point has also been brought up that many mathematical equations use 2π, also referred to as “double pi”, or Tau. Some equations that hold this mysterious “double pi” include the normal distribution, fourier transform, Cauchy’s integral formula, gauss-bonnet formula, and n^{th }roots of unity. It isn’t necessary that you understand or even recognize all of these equations; the important part is that they all include 2π, which could easily be replaced with Tau.

In the words of Vi Hart, “You can have your Pi and eat it , […] but I’ll be making Tau and eating two.”