Barrow (mathematical sciences, U. of Cambridge) has been concerned about, and writing about, the constants of nature for over two decades now. Here he adds a new chapter: recent technology for analyzing light from distant quasars reveals what conditions have been like over the past 11 billion years, and startling findings about whether or not the so-called constants have been fickle. Annotation (c)2003 Book News, Inc. , Portland, OR (booknews. com)