Pi Day Celebration "The Other Pi"

Abstract

Most people associate the greek letter pi in mathematics with the constant relating the diameter and the circumference of a circle. However, in mathematics there are many concepts and only a limited number of symbols, so most symbols have several meanings. Pi is no exception: pi is also commonly used to denote the fundamental group. This is an object that allows us to tell apart a circle from a figure eight and to distinguish a donut from a pie. It also helps explain why every mall map has a "You are Here" arrow. We shall explore this "other" pi.