Modern Physics, 3rd Edition

Book Preface

This textbook is meant to serve a first course in modern physics, including relativity, quantum mechanics, and their applications. Such a course often followsthe standard introductory course in calculus-based classical physics. The course addresses two different audiences: (1) Physics majors, who will later take a more rigorous course in quantum mechanics, find an introductory modern course helpful in providing background for the rigors of their imminent coursework in classical mechanics, thermodynamics, and electromagnetism. (2) Nonmajors, who may take no additional physics class, find an increasing need for concepts from modern physics in their disciplines—a classical introductory course is not sufficient background for chemists, computer scientists, nuclear and electrical engineers, or molecular biologists.

Necessary prerequisites for undertaking the text include any standard calculusbased course covering mechanics, electromagnetism, thermal physics, and optics. Calculus is used extensively, but no previous knowledge of differential equations, complex variables, or partial derivatives is assumed (although some familiarity with these topics would be helpful).

Chapters 1–8 constitute the core of the text. They cover special relativity and quantum theory through atomic structure. At that point the reader may continue with Chapters 9–11 (molecules, quantum statistics, and solids) or branch to Chapters 12–14 (nuclei and particles). The final chapter covers cosmology and can be considered the capstone of modern physics as it brings together topics from relativity (special and general) as well as from nearly all of the previous material covered in the text.

The unifying theme of the text is the empirical basis of modern physics. Experimental tests of derived properties are discussed throughout. These include the latest tests of special and general relativity as well as studies of wave-particle duality for photons and material particles. Applications of basic phenomena are extensively presented, and data from the literature are used not only to illustrate those phenomena but to offer insight into how “real” physics is done. Students using the text have the opportunity to study how laboratory results and the analysis based on quantum theory go hand-in-hand to illuminate such diverse topics as Bose-Einstein condensation, heat capacities of solids, paramagnetism, the cosmic microwave background radiation, X-ray spectra, dilute mixtures of 3He in 4He, and molecular spectroscopy of the interstellar medium.

This third edition offers many changes from the previous edition. Most of the chapters have undergone considerable or complete rewriting. New topics have been introduced and others have been rearranged. More experimental results are presented and recent discoveries are highlighted, such as the WMAP microwave background data and Bose-Einstein condensation. End-of-chapter problem sets now include problems organized according to chapter section, which offer the student an opportunity to gain familiarity with a particular topic, as well as general problems, which often require the student to apply a broader array of concepts or techniques. The number of worked examples in the chapters and the number of end-of-chapter questions and problems have each increased by about 15% from the previous edition. The range of abilities required to solve the problems has been broadened, so that this edition includes both more straightforward problems that build confidence as well as more difficult problems that will challenge students. Each chapter now includes a brief summary of the important points. Some of the end-of-chapter problems are available for assignment using the WebAssign program (www.webassign.net).