# In Pursuit of the Unknown

## In Pursuit of the Unknown

* 17 Equations That Changed the World*

By Ian Stewart

Basic Books, Hardcover, 9780465029730, 352pp.

Publication Date: March 1, 2012

Equations are modeled on the patterns we find in the world around us, says Stewart, and it is through equations that we are able to make sense of, and in turn influence, our world. Stewart locates the origins of each equation he presentsfrom Pythagoras's Theorem to Newton's Law of Gravity to Einstein's Theory of Relativitywithin a particular historical moment, elucidating the development of mathematical and philosophical thought necessary for each equation's discovery. None of these equations emerged in a vacuum, Stewart shows; each drew, in some way, on past equations and the thinking of the day. In turn, all of these equations paved the way for major developments in mathematics, science, philosophy, and technology. Without logarithms (invented in the early 17th century by John Napier and improved by Henry Briggs), scientists would not have been able to calculate the movement of the planets, and mathematicians would not have been able to develop fractal geometry. The Wave Equation is one of the most important equations in physics, and is crucial for engineers studying the vibrations in vehicles and the response of buildings to earthquakes. And the equation at the heart of Information Theory, devised by Claude Shannon, is the basis of digital communication today.

An approachable and informative guide to the equations upon which nearly every aspect of scientific and mathematical understanding depends, In "Pursuit of the Unknown" is also a reminder that equations have profoundly influenced our thinking and continue to make possible many of the advances that we take for granted.

*In Pursuit of the Unknown*…

** Publishers Weekly**“Stewart shares his enthusiasm as well as his knowledge in this tour of ground-breaking equations and the research they supported…. An entertaining and illuminating collection of curious facts and histories suitable for random dipping-in or reading straight through.”

**“Stewart provides clear, cogent explanations of how the equations work without burdening the reader with cumbersome derivations…. He gives a fascinating explanation of how Newton’s laws, when extended to three-body problems, are still used by NASA to calculate the best route from Earth to Mars and have laid the basis for chaos theory. Throughout, Stewart’s style is felicitous.”**

*Kirkus Reviews*

**“Seemingly basic equations have enabled us to predict eclipses, engineer earthquake-proof buildings, and invent the refrigerator. In this lively volume, mathematician Ian Stewart delves into 17 equations that shape our daily existence, including those dreamed up by the likes of Einstein, Newton, and Erwin Schrödinger.”**

*Discover*

*Maclean’s*“Stewart is

*the*finest living math popularizer – a writer who can tackle eye-spraining mathematical topics approachably, and yet dazzle hard-core nerds with new and surprising information. It is hard not to get your money’s worth from him, and in a book like this he is at his best because of the very wide ground covered.”

*Library Journal*“Stewart’s expertise and his well-developed style (enhanced by a nice sense of humor) make for enjoyable reading…. [A] worthwhile and entertaining book, accessible to all readers. Recommended for anyone interested in the influence of mathematics on the development of science and on the emergence of our current technology-driven society.”

*Washington*** Independent Review of Books**“Stewart has managed to produce a remarkably readable, informative and entertaining volume on a subject about which few are as well informed as they would like to be.”

*New York*

*Journal of Books*“Stewart is a genius in the way he conveys his excitement and sense of wonder…. He has that valuable grasp of not only what it takes to make equations interesting, but also to make science cool.”

**Steve Mirsky,**

*Scientific American*“[Stewart] takes the reader on an engaging tour of vital math for a modern world…. I highly recommend Stewart’s wonderfully accessible book.”

*Physics Today*“

*In Pursuit of the Unknown*is an interesting and highly entertaining book. It would make a great gift for a bright high school grandchild who has expressed interest in a technical life, or for a physicist’s own secret reading.”