# The Mathematics of Rivers Meandering

The notorious irrational number pi goes beyond math. It is a recurring character in many parts of nature. It even appears in Heisenberg's uncertainty principle in quantum physics. That's why no number can claim more fame than pi.

Last week, we talked about how pi emerges in the shapes of rivers. In 1996, Hans-Henrik Stølum claimed that pi controls the chaotic meandering (sinuosity) of rivers. Actually, Albert Einstein was the first to explain this fascinating fact.

According to Stølum, the sinuosity of a river should be between 2.7 and 3.5, and the average sinuosity of rivers around the world approaches pi!

To learn more about the relationship between pi and the rivers, you should definitely watch Numberphile's video about it.