What this book is about

Quantum mechanics is an extraordinarily successful theory. The quantum mechanical description of the structures and spectra of atoms and molecules is virtually complete, and in principle, this provides the basis for understanding all of chemistry. Quantum mechanics gives detailed insight into many thermal, electrical, magnetic, optical, and elastic properties of condensed materials, including superconductivity, superfluidity, and Bose-Einstein condensation. Quantum mechanics underlies the theory of nuclear structure, nuclear reactions, and radioactive decay. Quantum electrodynamics (QED), an outgrowth of quantum mechanics and special relativity, is a very successful and detailed description of the interaction of charged leptons (i.e., electrons, muons, and tau leptons) with the electromagnetic radiation field. More generally, relativistic quantum field theory, the extension of quantum mechanics to relativistic fields, is the basis for all successful theoretical attempts so far to describe the phenomena of elementary particle physics.

We assume that you, the reader, have some elementary knowledge of quantum mechanics and that you know something about the historical development of the subject and its main principles and methods. We take advantage of this background, after a brief mathematical review in Chapter 2, by stating the rules of quantum mechanics in Chapter 3. An advantage of this approach is that all the rules are set forth in one place so that we can focus on them. In Chapter 3 we also describe application of the rules to several real physical situations, most significantly experiments with photon polarizations. Following some development of wave mechanics (Chapter 4), we illustrate the rules with additional examples (Chapter 5). We then develop the theory further in subsequent chapters, giving as many examples as we can from the physical world.