I can across an interesting idea today. Put simply, the idea is that the ratio for relating the size of a circle to its circumference has been badly chosen.
That is to say, Pi (π), the ratio of the Circumferences to the Diameter of a circle is an awkward choice.
The argument goes that using the ratio of the Circumference to the Radius instead would make many things simpler and more obvious. The proposed symbol for this is Tau (τ).
All is explained at the Tau Day website. http://www.tauday.com/
I found it very persuasive. What do others think?