We live in the age of a new scientific revolution, one as sweeping and profound as that launched by Copernicus, one that continues to unfold. Beginning at the turn of the century, with the discovery of relativity and quantum mechanics, this second revolution has collapsed the elegant old Newtonian universe. Yet physicists have yet to complete a replacement, as they search for a grand unified theory. Now cosmologist Lee Smolin offers a startling new approach--a theory of the universethat is at once elegant, comprehensive, and radically different from anything proposed before. In The Life of the Cosmos, Smolin cuts the Gordian knot of cosmology with a simple, powerful idea: "The underlying structure of our world," he writes, "is to be found in the logic of evolution." Today's physicists, he writes, have overturned Newton's view of the universe, yet they continue to cling to an understanding of reality not unlike Newton's own--as a clock, an intricate yet static mechanism. Smolin sees the very fabric of reality as changing and developing. "The laws ofnature themselves," he argues, "like the biological species, may not be eternal categories, but rather the creations of natural processes occuring in time." A process of self organization like that of biologal evolution shapes the universe, as it develops and eventually reproduces through black holes, each ofwhich may result in a new big bang and a new universe. Natural selection may guide the appearance of the laws of physics, favoring those universes which best reproduce. Smolin's ideas are based on recent developments in cosmology, quantum theory, relativity and string theory, yet they offer, at the same time, a completely new view of how these developments may fit together to form a new theory of cosmology. The result will be a cosmology according to which the fact that the universe is a hometo life will be seen to be a natural consequence of the fundamental principles on which it has been built. This will be in direct contrast with the older point of view, coming from Newtonian physics, according to which the fact that the universe contains life, or any form of organization, isaccidental. We exist in a universe filled with an array of beautiful structures ranging from the molecular organization of living things upwards to the galaxies, and science must ultimately explain why. In so doing, science will give us a picture of the universe in which, as the author writes, "the occurence of novelty, indeed the perpetual birth of novelty, can be understood." Lee Smolin is one of the leading cosmologists at work today, and he writes with an expertise and force of argument that will command attention throughout the world of physics. As startling as many of his ideas sound, each is subject to testing, and he includes several ideas on how they might be confirmed or disproved. Perhaps most important, however, is the humanity and sharp clarity of his prose, offering access for the layperson to the mind bending space at the forefront of today'sphysics.