# π versus τ: A modest Proposal

**Ahh! The great pi vs tau debate of 2010 lives on. **

**Given that this blog has covered such contentious and pressing issues as the “king” of the generalized fibonacci sequences, it seems only natural that I weigh in on the defining mathematical debate of the decade. **

**For the lost, this is a circle:**

**Pi is circumference divided by diameter, and Tau is circumference divided by radius:**

**Some people who apparently don’t have anything better to do ^{1} like to argue about which is the better of the two circle constants.**

**I hope to resolve this dispute once and for all.**

**But before we do that, let’s introduce our competitors:**

**Prominent tauists Michael Hartl, argues for the irrationality of pi in his seminal piece “The Tau Manifesto.” His principal argument goes something like this:**

**“When measuring angles in radians, a full circle is an ugly 2π, while it could be a clean (one) τ. This fact percolates through mathematics, depositing a 2π into various equations, and defaces our normally-elegant subject. It also makes angle measures counter-intuitive, like a quarter of a circle actually being π/2 radians.”**

**Pi supporters, on the other hand, are “very comfortable with pi, and multiplication by two.” ^{2}**

**So what’s to do? How can we bridge this treacherous chasm?**

**Fortunately, there is a solution. **

**Notice how I started my 53 word summary of “The Tau Manifesto”**

**That little bit is the key to understanding this whole dilemma. You see, we measure angles using the radius of a circle, while employing a constant defined in terms of its diameter. It’s no wonder we have a factor of two lying around everywhere: our tools of measurement themselves are off by a factor of two.**

**The problem, then, isn’t the usage of pi. Rather, it’s the mismatch between our unit of measurement and our choice of constant.**

**This suggests a rather simple compromise: use diameters instead of radii to measure angles. **

**The benefits of this compromise are clear: **

**Pi-supporters get to keep using pi, and thus can claim a technical victory. **

**Tau-ists get to revel in their intuitive understanding of angles.**

**Everyone else? Ehh. They’ll just be confused for awhile.**

^{1}guilty

^{2}Siddhartha Gadgil, seen in the pi manifesto