Book excerpt: Offers clear explanations of the basic concepts, history, philosophy, fundamental theories and laws of physics, as well as biographical entries featuring physicists who have contributed to our knowledge of the physical world. The set will be useful for physics students from high school through graduate school and for general readers exploring the mysteries of everyday life, such as: What causes earthquakes?; How do CAT Scans work?; or, How do clouds form? Articles are arranged in alphabetical order and include cross-references and bibliographic references as recent as 1996. Volume one contains a Reader's Guide which identifies some key entries in the encyclopedia's plan. A table of symbols and abbreviations is included at the beginning of each volume to assist readers unfamiliar with any mathematical or scientific notation that might arise. The 4-volume set offers readers clear explanations for the phenomena, concepts, and laws that are the foundation of every other branch of science from astronomy to zoology. The entries are written to let readers satisfy their curiosity without becoming lost in high-level jargon. Specifically written to supplement the high school physics curriculum, the Encyclopedia satisfies the informational needs of a broad range of readers.