# Tau

**Tau**, denoted , is most commonly used as 2 or 2 pi. Tau is the number of radians in a circle. For a convincing proof that is a better circle constant than , see The Tau Manifesto by Michael Hartl. This following section will summarize one main point of the Tau Manifesto.

## Why Is Better Than

Have you ever been in geometry class and been asked to graph sine waves with their ridiculous extra factor of 2 in the x-axis? Have you ever thought radian angle measure was hopelessly tainted with the superfluous and yet unavoidable factor of 2 (There are * 2* radians in a full revolution)? resolves that. One is one revolution. Simple as that. While you have to remember that radians is

**NOT**of a revolution, but is equal to of a revolution because of that idiosyncratic factor of 2, radians is just of a revolution. Likewise, radians is just of a revolution, radians is just 9001 revolutions, radians is just 123456789 revolutions, and radians is revolutions for any real .

Some may argue that is simpler than , but as noted in the Tau Manifesto, many quadratic forms in physics contain a factor of which is unavoidable.

## Other Uses of Tau

can have other meanings:

- Tau is the 19th letter of the Greek alphabet.
- Tau is also an uncommon name for Phi.