Eminent scientist Joseph Silk gives the inside view of cosmology: how scientists reconstruct the evolution of the universe, from its moment of origin - the Big Bang - to the distant future. Using plain language, he describes the implications of major discoveries such as fluctuations in the cosmic microwave background radiation and investigates the vital cosmological questions, What is the future of the universe? What is the nature of most of the matter in the universe? "The best introduction to cosmology for the general reader currently available." Michael Rowan-Robinson, Nature