Where did we come from? Before there was life there had to be something to live on - a planet, a solar system. During the past 200 years, astronomers and geologists have developed and tested several different theories about the origin of the solar system and the nature of the Earth. The three volumes that together make up A History of Modern Planetary Physics present a survey of these theories. The age of the Earth has been one of the most disputed numbers in science since the seventeenth century. Transmuted Past follows the development of theories of stellar evolution and nucleosynthesis in the twentieth century and describes radiometric methods for estimating the age of the Earth. Professor Brush also offers perspectives on the changing reputation of planetary science relative to the ‘pure’ sciences, such as physics, and a comparison of history and geology as ways of studying the past.