# Tau is Greater Than Pi Updated 2021-July-28

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## News

2021-June-28  Published this evolving⁠ article.

## What is tau (τ)

Tau, which is also known as τ, is a mathematical constant that is 2 times π:

     π = 3.14159265358…
τ = 2π = 6.28318530717…

These are irrational numbers and each of the above trailing ellipses (…) represent an unending patternless sequence of digits.

## τ is everywhere

In mathematics and science, 2π (τ) occurs in a lot of formulas. For example: In a circle of radius r, the circumference is 2πr or τr.

Another example is Cauchy’s Integral Formula:

$$f(a) = \frac{1}{2\pi i} \oint\frac{f(z)}{z-a}dz$$

which, if you replace 2π with τ, can also be written as:

$$f(a) = \frac{1}{\tau i} \oint\frac{f(z)}{z-a}dz$$

Because τ simplifies a lot of formulas, there is a movement to make it — rather than π — one of the fundamental constants of mathematics.

## What is Tau Day

Analogous to Pi Day, which is March 14, is Tau Day, which is June 28. I hope you enjoy this and all Tau Days!🥧🥧