COSMIC NUMBERS

Cheerful but not dumbed-down discussions of 13 fundamental numbers.

Unlike many popular-science writers, Stein (Mathematics/California State Univ., Long Beach; How Math Can Save Your Life, 2010, etc.) does not boast that he avoids math, so readers should remember their high-school algebra. Almost everyone knows that light has a speed and that temperatures can drop to absolute zero. However, no one knew that 500 years ago, and Stein recounts how astronomers (in the case of light) and physicists (for absolute zero) teased out the details. Fundamentals discovered more recently bear the names of their founding geniuses: Planck’s constant that began the quantum revolution, Hubble’s constant that measures how fast the universe is expanding, the Schwarzschild radius (how to make a black hole; squeezing the Earth to the size of a pea would do it) and the Chandrasekhar limit, which determines if an aging star will go quietly or light up the galaxy in a supernova (our sun is too small to explode). Stein is not shy about explaining the mathematics behind these phenomena at length rarely seen in a popular-science book. Readers who keep a pencil and paper handy will benefit, but those who skim will not regret the experience. While not math-free, the book is illustration-free, so readers should make liberal use of that pencil and paper because many explanations become clearer with a simple diagram. Every educated reader should know what these numbers mean. Stein casts his net widely, delivering an entertaining history of each, often wandering into areas of science only distantly related but no less worthwhile.