## Math Encounters -- Doing Math in Public

In his new book, The Joy of X: A Guided Tour of Math from One to Infinity (Houghton Mifflin Harcourt), Steven Strogatz ’80 writes for readers who want a “second chance at math.” Based on his popular series of online articles for The New York Times, the book seeks to help educated readers find beauty in a subject that they may have been glad to leave behind in high school.

“Even if you never use math, you can still take pleasure in it — with help,” says Strogatz, a professor of applied mathematics at Cornell University.

The Joy of X offers a survey of the major elements of math, from the simple joys of counting taught on Sesame Street to number theory. Strogatz’s approach is to connect math to everyday subjects. One chapter looks at the O.J. Simpson trial and how both the prosecution and the defense misused probability theory. In another chapter, Strogatz explores whether love affairs can be explained by differential equations.

Strogatz also takes a look at Google, whose success was built on the principles of linear algebra. Google helped make it easier to search the Web by ranking pages based on the number of other Web pages linked to them. By writing algorithms based upon this insight, Google became the Internet’s dominant search engine.

People may be more interested in math today because of companies like Google — or, perhaps, because of the large amounts of money made by Google. Math has helped make many a billionaire, Strogatz says. Technical advances on Wall Street and in the pharmaceutical industry would not have been possible without advanced math.

For Strogatz, math has a remarkable unifying effect. He sees patterns between the spirals on his fingertips and the spirals in the DNA double helix, and between spiral galaxies and the spirals of leaves picked up by the autumn wind. Mathematical patterns are everywhere, he argues, if you know where to look.

“There is a harmony in the universe and in our own selves and all around us that becomes easier to see and appreciate once you understand math,” he says.

Strogatz’s research focuses on social networks. He is perhaps best known for a paper he co-authored inspired by the idea of “six degrees of separation.” He also used mathematical principles to analyze the shifting alliances among European nations prior to World War I.

Strogatz acknowledges that math can be daunting, but he argues that it is not beyond the reach of the curious reader. He hopes that his book will help people develop an appreciation for a difficult but rewarding subject.

“If I can help someone see the beauty in math, that to me is really analogous to the beauty in music or in art,” Strogatz says. “It gives them one more thing that enriches their lives.”

WHAT HE RECENTLY READ: The Art of Learning: An Inner Journey to Optimal Performance by Josh Waitzkin

What he liked about it: “It’s a very interesting take on how you get to be great at something [from] someone who has achieved world-class status in two different fields, in martial arts and in chess.”