Recently a student inquired whether the number pi “has physical significance”. Should we treat pi like we do constants of nature?

Offhand, I would answer yes, with enthusiasm. What really is the difference between the universal gravity constant, the charge on the electron, the speed of light in the vacuum, and pi? They are all numbers that are embedded in the structure of our universe, and the laws of physics.

Numberphile to the rescue here. I knew that Archimedes was first to accurately estimate pi, and his ingenious method is described here. But did you know that you can also experimentally determine pi by scattering matchsticks on a specially marked off grid and count the number of matches that cross a line on that grid? Click on the video above to see how!