The more we know, the better we understand how little we know. As the fundamental nature of matter is gradually revealed, the crucible where it was created--the nuclear furnace at the core of every star--is glimpsed. These furnaces have been ""seen"" for centuries by their radiation: light, radio waves, X-rays, gamma rays, superenergetic electrons, and neutrinos--shy travelers who virtually refuse to be photographed. Step by step, we have moved from learning about matter by stargazing to using understanding about matter to explain the stars. But while our knowledge has never been greater, our puzzlement over the remaining mysteries is at an all-time high. We have moved from wondering why the sky is neither infinitely bright nor infinitely hot to wondering how it is that we exist at all. As in their earlier books, Jespersen and Fitz-Randolph here combine lucid explanations, anecdotes, and history in an instructive, entertaining guide to humankind's fascination with the signals from space. Less imaginative in what it includes than the more wide-ranging From Quarks to Quasars (1987) and more like an introductory textbook on cosmology; still, far more fascinating than most textbooks. Glossary; bibliography; index.