The serenity of a clear night sky belies the evidence—gathered by balloons, rockets, satellites, and telescopes—that the universe contains centers of furious activity that pour out vast amounts of energy, some in regular cycles and some in gigantic bursts. This reader-friendly book, acclaimed by Nature as "excellent and uncompromising," traces the development of modern astrophysics and its explanations of these startling celestial fireworks. This lively narrative ranges from the gravitational theories of Newton and Einstein to recent exciting discoveries of such violent phenomena as supernovae, pulsars, X-ray sources, active galaxies, radio sources, and quasars. An in-depth exploration of the Big Bang covers both conventional theory and subsequent issues that cast doubt upon its explanation of the birth of the universe. Several appendixes offer supplements to the text's main topics, and a helpful glossary and tables of references appear at the end.