The History of Modern Physics 1800-1950 Volume 12 The History of Modern Physics, 1800-1950 EDITORIAL BOARD Gerald Holton, Coeditor Harvard University Katherine R. Sopka, Coeditor Four Corners Analytic Sciences Stephen G. Brush University of Maryland Roger H. Stuewer University of Minnesota Spencer R. Weart Center for History of Physics, American Institute of Physics John A. Wheeler Princeton University University of Texas The History of Modern Physics, 1800-1950 TITLES IN SERIES VOLUME 1 A/sos by Samuel A. Goudsmit VOLUME2 Project Y.· The Los Alamos Story Part /: Toward Trinity by David Hawkins Part II: Beyond Trinity by Edith C. Truslow and Ralph Carlisle Smith VOLUME 3 American Physics in Transition: A History of Conceptual Change in the Late Nineteenth Century by Albert E. Moyer VOLUME,4 The Question of the Atom: From the Karlsruhe Congress to the First Solvay Conference, 1860-1911 by Mary Jo Nye VOLUME 5 Physics For a New Century: Papers Presented at the 1904 St. Louis Congress VOLUME6 Basic Bethe: Seminal Articles on Nuclear Physics, 1936-1937 by Hans A. Bethe, Robert F. Bacher, and M. Stanley Livingston VOLUME 7 History of the Theories of Aether and Electricity: Volumes I and II by Sir Edmund Whittaker The History ofM odern Physics, 1800-1950 VOLUME 8 Radar in World War II by Henry Guerlac VOLUME9 Atoms in the Family: My Life with Enrico Fermi by Laura Fermi VOLUME 10 Quantum Physics in America: The Years Through 1935 by Katherine R. Sopka VOLUME 11 The Theory of Heat Radiation by Max Planck VOLUME 12 The Conceptual Development of Quantum Mechanics by Max Jammer INTRODUCTORY NOTE The Tomash/A merican Institute of Physics series in the History of Modem Physics offers the opportunity to follow the evolution of physics from its classical period in the nineteenth century when it emerged as a distinct discipline, through the early decades of the twentieth century when its modem roots were established, into the middle years of this century when physicists continued to develop extraordinary theories and techniques. The one hundred and fifty years covered by the series, 1800 to 1950, were crucial to all mankind not only because profound evolutionary advances occurred but also because some of these led to such applications as the release of nuclear energy. Our primary intent has been to choose a collection of historically important literature which would make this most significant period readily accessible. We believe that the history of physics is more than just the narrative of the development of theoretical concepts and experimental results: it is also about the physicists individually and as a group-how they pursued their separate tasks, their means of support and avenues of communica tion, and how they interacted with other elements of their contemporary society. To express these interwoven themes we have identified and se lected four types of works: reprints of "classics" no longer readily avail able; original monographs and works of primary scholarship, some pre viously only privately circulated, which warrant wider distribution; anthologies of important articles here collected in one place; and disser tations, recently written, revised, and enhanced. Each book is prefaced by an introductory essay written by an acknowledged scholar, which, by placing the material in its historical contei:t, makes the volume more valuable as a reference work. The books in the series are all noteworthy additions to the literature of the history of physics. They have been selected for their merit, distinc tion, and uniqueness. We believe that they will be of interest not only to the advanced scholar in the history of physics, but to a much broader, less specialized group of readers who may wish to understand a science that has become a central force in society and an integral part of our twentieth-century culture. Taken in its entirety, the series will bring to the reader a comprehensive picture of this major discipline not readily achieved in any one work. Taken individually, the works selected will surely be enjoyed and valued in themselves. Max Jammer }2 The History ofM odern Physics Volume 1800-1950 The Conceptual Development of Quantum Mechanics MAX JAMMER , ••, Tomash Publishers A I P American Institute of Physics Copyright 1989 by the American Institute of Physics. All rights reserved. Printed in the United States of America. Library of Congress Cataloging in Publication Data Jammer, Max. The conceptual development of quantum mechanics/Max Jammer.-2nd ed. p. cm.-(The history of modem physics, 1800-1950; v. 12) Bibliography: p. Includes index. ISBN 0-88318-617-9 1. Quantum theory. I. Title. II. Series. QC174.12.J26 1989 530. l '2-dc20 89-6639 CONTENTS PAGE Preface to the Second Edition ................................................ xi Preface . . . .. . . . .. . . . .. . . . .. . . . .. . . .. . . .. . . .. . . . . .. . . . .. . . . .. . . .. . . . .. . . .. . . . . .. . . .. . . . .. . .. xiii CHAPTER 1 THE FORMATION OF QUANTUM CoNCEPTS 1.1 Unsolved Problems in Classical Physics.......................... 1 1.2 The Concept of Quanta of Energy ................................... 7 1.3 The Concept of Quanta of Radiation............................... 21 1.4 Elaborations of the Concept of Quanta............................ 36 1.5 Applications of Quantum Conceptions to the Molecular Kinetic Theory ..................................... 45 CHAPTER2 EARLY APPLICATIONS OF QUANTUM CONCEPTIONS TO LINE SPECTRA 2.1 Regularities in Line Spectra............................................. 65 2.2 Bohr's Theory of the Hydrogen Atom............................. 70 CHAPTER3 THE OLDER QUANTUM THEORY 3.1 Quantum Conditions and the Adiabatic Principle .......... 93 3.2 The Correspondence Principle......................................... 110 3.3 The Zeeman Effect and Multiplet Structure.................... 118 3.4 Exclusion Principle and Spin ........................................ 130 1.. CHAPTER4 THE TRANSITION TO QUANTUM MECHANICS 4.1 Applications of Quantum Conceptions to Physical Optics ............................................................ 166 ix