Ian Stewart. In Pursuit of the Unknown: 17 Equations that Changed the World. (New York: Basic Books, 2012)

I stumbled across this book when a friend mentioned it to me, albeit in quite a vague manner. Once I read the subtitle, of course, I was hooked. As someone who has loved Mathematics for as long as he can remember, I could not resist the temptation to read a book about how Mathematical equations have played a key role in giving us the world we live in today.

As the subtitle suggests, Stewart describes the meaning and influence of seventeen Mathematical equations from all sorts of domains – from geometry to physics and from signal processing to economics. Some, such as the Pythagorean Theorem and E=mc², are what one may call ‘usual suspects’ given that they have entered common discourse even if most people have no clue about what the equations mean or of how to use them. Others are more elusive, such as the Navier-Stokes equation and the Black-Scholes equation, the knowledge of which is restricted only to a handful of people in the know. Still others, such as the second law of thermodynamics and the definitions of the derivative and the imaginary number i, might cause high school students around the world to shudder.

Stewart does a commendable job both of describing the meaning of each equation and of outlining its uses. While some knowledge of Mathematics is definitely helpful, Stewart has not targeted the book toward those with much knowledge of Mathematics. This makes the book far more accessible that it otherwise would have been.

Stewart also does not shy away from the downsides of using Mathematics. He shows that, when Mathematics is used as a tool within other disciplines, the ethical considerations must be dealt with within those disciplines for Mathematics itself is unconcerned about such issues. Thus the power of Mathematics is itself a major drawback for, in allowing itself to be used by other disciplines, it subjects itself to the whims of those disciplines.

The book, as a whole, is a remarkably good read and I could not put it down once I began. For those who benefit daily from the usefulness of Mathematics and who still wonder about why it is taught in schools, I would recommend this book as an eye-opener. Of course, I would recommend this book to anyone who has an inkling of curiosity coursing through their veins!