Book excerpt: Concise, signed articles--most of them including bibliographic references--on physics in general, its major areas, divisions, and subdivisions as well as related topics such as astrophysics, geophysics, and biophysics. Intended for physicists who need information outside their special field of interest, librarians, teachers, engineers, and other scientists "who encounter physical concepts in pursuit of their profession."--Pref. As a rule, the technical level of the writing is higher for the more specialized areas than for the general topics. Useful cross references. Indexed. Published 1974.