Ever heard of Tau? Hint: you can’t serve it a la mode. Tau is a mathematical measurement equivalent to twice the value of pi. Mathematicians have recently been debating the relative merit of tau vs. pi, considering that the radius (rather than the diameter) is often the important measurement and is mostly associated with 2π rather than pi alone. In other fields of mathematics beyond the geometry of circles, such as Riemann zeta functions, Gaussian distributions, roots of unity, integrating over polar coordinates and pretty much anything involving trigonometry, pi is preceded with a 2 more often than not – one reason why Tauist argue that we should celebrate Tau instead. While Pi Day (March 14th, i.e. 3/14) may be officially recognized by Congress, be sure to remember Tau on June 28 (6/28) next year.