Adapted from “Infinite Powers: How Calculus Reveals the Secrets of the Universe,” which will be published on April 2 by Houghton Mifflin Harcourt. When my children were young, they liked to stare at a pie plate hanging in our kitchen, with the digits of pi running around the rim and spiraling in toward the center, shrinking in size as the numbers swirled into the abyss. Pi, as we all learned in school (and are reminded every March 14, on Pi Day), is defined as the ratio of a circle’s circumference to its diameter. For some people, Pi Day is an occasion to marvel at circles, long revered as symbols of perfection, reincarnation and the cycles of nature. Mathematically, pi is less a child of geometry than an early ancestor of calculus, the branch of mathematics, devised in the 17th century, that deals with anything that curves, moves or changes continuously.

Source: New York Times March 14, 2019 06:22 UTC