Recently, pi has been under “attack” by a new constant called tau. You can read about it here:
- The original article
πis wrong written by Bob Palais (published in 2000/2001).
- The Tau Manifesto written by Michael Hartl (launched on June 28th, 2010).
- The video Pi is (still) wrong by Vi Hart (uploaded on March 14th, 2011).
I find tau to be quite interesting, but alas, someone has to defend pi.
Check out the Pi Manifesto on why pi really is the true circle constant!