How old is the universe? What do the atoms in our bodies, our very existence, tell us about the history of the universe? How heavy is the vacuum? How do galaxies form? Michael Rowan-Robinson answers these questions and encapsulates all that modern astronomy has discovered about the universearound nine numbers. His motto is Montaigne's "What do I know?" And the reader emerges with a genuine feel for what we do really know about the universe and also what we do not. Only one of the nine numbers is known with real precision, while four of them are not known at all. Complicated ideas like the origin of the elements, the General Theory of Relativity, quantum theory, and the standard model of particle physics, ideas that constitute modern cosmology, are explainedin a simple way. Speculative ideas like inflation, Theories of Everything, strings and superstrings, are also in this book, but they are treated with a refreshing skepticism. Although most of what we know has been learned during the twentieth century, Rowan-Robinson gives an historical perspective and honors the achievements of the Greeks, renaissance astronomers, and the age of Newton. He ends the book with an analysis of the future, predicting that with the advent ofthe MAP and PLANCK-Surveyor space missions, the Large Hadron Collider, and other planned experiments, all nine numbers will be accurately known by 2015. However, he stresses that many questions and mysteries will remain, and the book concludes with the idea that the origin of the Big Bang willremain a mystery in 2100 and perhaps even in the year 3000. Read Less