This is a fascinating and popular account of the very large and the very small, from the universe as a whole to subatomic physics. It includes qualitative explanations of quantum mechanics and relativity, the big bang with inflation, the synthesis of elements, atoms, nuclei, subnuclear physics, quarks, leptons, and other elementary particles. It also gives an account of dark matter and dark energy. In summary, it provides and overview of what we know about the universe and what it is made of, and also what we don't know.