This essential reference work is the most popular paperback dictionary of physics available. It contains over 3,500 clear and concise entries, covering all commonly encountered physics terms and concepts, including terms relating to astronomy and astrophysics, and terms relating to physical chemistry. Over 100 diagrams and tables support the text. Feature entries give in-depth analysis of key topics such as crystal defects, magnetic resonance imaging, and the solar system. The dictionary also includes biographies of important scientists, and an invaluable set of appendices. Now in its fifth edition, this best-selling dictionary has been revised to bring it completely up-to-date, with over 250 new entries. New features include an index of useful web links, up-to-date entries on topics such as dark energy, decoherence, quantum computing, and information theory, and chronologies of major discoveries in the main fields of physics, including atomic theory, cosmology, and microscopy An excellent introduction to physics for beginners, and an ideal reference tool for students of physics, either at school or at university.