Just when you thought you were smart because you knew that Pi equals 3.14159 - the infinite number derived when you divide the circumference of a circle with it's diameter, comes a move to replace it.

"For all these years, we have been looking at the wrong number when we have been looking at Pi," said Kevin Houston, of the School of Mathematics at the University of Leeds, who is leading the British arm of the Tau campaign.

"Pi simply isn't the most natural number that we should associate with a circle. The proper number is 2Pi, or Tau."

Or, as U.S. Physicist Dr. Michael Hartl puts it:

Pi is a "confusing and unnatural choice" for the circle constant. "I find it fascinating that the absurdity of Pi was lying in plain sight for centuries before anyone seemed to notice," he said.

Mathematicians want to replace Pi with Tau.

Tau is the number you get when you use a circle's radius instead. It fits neatly into equations in place of 2Pi and clears up the problem of radians, which is the way mathematicians measure angles.