The famous mathematical ratio, estimated to more than 22 trillion digits (and counting), is the perfect symbol for our species’ long effort to tame infinity. By Steven Strogatz This article, ...

Pi, a mathematical constant denoted by the Greek letter π, is the ratio of a circle's circumference C to its diameter d: π = C/d. The circumference of a circle is, in turn, equal to 2πr, where r is ...