Steve Mirsky in Scientific American:
In his new book, In Pursuit of the Unknown: 17 Equations That Changed the World, Ian Stewart recounts one of the worst jokes in the history of science. You can develop your own setup from first principles once you know the punch line: “The squaw on the hippopotamus is equal to the sum of the squaws on the other two hides.” Never mind how Native Americans were in possession of a hippopotamus—the important thing is that the Pythagorean theorem is so well known that comedy writers consider it fair game even if that game couldn’t possibly be found on the correct continent.
Stewart, who formerly wrote the Mathematical Recreations column for Scientific American, takes the reader on an engaging tour of vital math for a modern world. We go from Pythagoras’ right triangle (a2 + b2 = c2)—nice—to Newton’s law of gravity (F = G)—good—to Einstein’s special theory of relativity (E = mc2)—still with you—to the Navier-Stokes equation governing the movement of fluids——which pretty much convinced me to change my career trajectory from science to science journalism.
I highly recommend Stewart’s wonderfully accessible book and now share with you some additional equations not in its pages but of importance to me, personally.