Physical science, both in history and in practice, is an integrated and uncompartmented field of knowledge. The foundations of physics, for example, lie in astronomy and chemistry; the geologist and the astronomer solve their problems with the aid of physics and chemistry.
This book includes material from physics, chemistry, geology and astronomy, and I have let the nature of its subject-matter dictate its own integration. The presentation of geology, for example, depends on and makes active use of the principles of physics and chemistry. Nuclear reactions and the structure of atoms play an important part not only in physics, but also in geology and astronomy. The concepts of energy transfer and dynamic equilibrium find many concrete applications throughout the book.
By emphasizing the logical development and interdependence of topics, I have tried to encourage reasoning and understanding rather than memorizing. Many topics are developed to a considerable depth. This is not only because they are important in several fields, but because useful understanding and a satisfying comprehension depend upon one’s going beyond superficialities. A topic grows in interest with further and more complete pursuit. By following a chain to its end, one achieves better results with less effort than he does by merely contemplating a smaller number of isolated links.