Riemann's hypothesis for a general rule to determine how many prime numbers exist in a given quantity was first posed offhandedly to the Berlin Academy in 1859. Today, having been neither proved or disproved, it remains the "great white whale" of mathematics and a missing key to advances in code theory and atomic physics. Derbyshire introduces this captivating mathematical problem in alternating chapters of mathematical exposition (some college calculus required) and biography and history (for general readers interested in mathematics). Derbyshire, a mathematician and linguist by education, is the author of Seeing Calvin Coolidge in a Dream (1996). Annotation (c) Book News, Inc., Portland, OR (booknews.com)