Many people believe π is wrong, and here's why.
Tomorrow is Pi Day, so in honor of that, I will slander π! Let's begin with a bit of background knowledge.
π is equal to the circumference of a circle divided by its diameter. It's equal to about 3.141592653589793238462643383279502884197169399375105820974944592307816406286208998.* But there is a growing movement to use a number called tau instead, denoted by the Greek letter τ. τ is equal to the circumference of a circle divided by its radius. τ is equal to 2π, or about 6.2831.** τ can be a more logical choice than π for the circle constant.
The primary argument for τ has to do with radians. The system of measuring angles with degrees is rather arbitrary. Why should a circle be 360 degrees? So, in higher math, radians are used instead. Here's how radians are defined: in a circle with radius 1, the measure of an angle is equal to the length of the arc across from it. Let's look at some sample angles.
(From the Tau Manifesto.)
A 360° angle spans the entire circle. To calculate its circumference, we take π times the diameter, which is 2, since the radius is 1. This gives us 2π.
For 180°, or 1/2 of a circle, we get π.
For 120°, or 1/3 of a circle, we get 2π/3.
For 90°, or 1/4 of a circle, we get π/2.
For 60°, or 1/6 of a circle, we get π/3.
For 45°, or 1/8 of a circle, we get π/4.
For 30°, or 1/12 of a circle, we get π/6.
Do you see the problem? There is an errant factor of 1/2 floating around here that causes all of the radian measures to fall askew. Where did this come from? Well, π is defined based on the diameter, and our circle has a radius of 1 … and a diameter of 2. How do the tauists combat this problem? Simple. Use τ. After all, τ is defined based on the radius, which is more widespread than the diameter anyhow.
top of page
Search
bottom of page