The conceptual development of quantum mechanics

424 Pages·1966·22.845 MB·English

by  Max Jammer

nunc cognosco ex parte
TRENT UNIVERSITY
LIBRARY
—S~°l
fgl
SEF 2 5 1967
Digitized by the Internet Archive
in 2019 with funding from
Kahle/Austin Foundation
https://archive.org/details/conceptualdeveloOOOOjamm
The Conceptual Development
of Quantum Mechanics
INTERNATIONAL SERIES IN PURE AND APPLIED PHYSICS
Leonard I. Schiff, Consulting Editor
adler, bazin, and schiffer Introduction to middleton An Introduction to Statistical
General Relativity Communication Theory
allis and herlin Thermodynamics and morse Vibration and Sound
Statistical Mechanics morse and feshbach Methods of Theoretical
becker Introduction to Theoretical Mechanics Physics
bjorken and drell Relativistic Quantum muskat Physical Principles of Oil Production
Fields newton Scattering Theory of Waves and
bjorken and drell Relativistic Quantum Particles
Mechanics present Kinetic Theory of Gases
chodorow and sussKiND Fundamentals of read Dislocations in Crystals
Microwave Electronics richtmyer, kennard, and lauritsen Intro¬
clark Applied X-rays duction to Modern Physics
collin Field Theory of Guided Waves schiff Quantum Mechanics
evans The Atomic Nucleus seitz The Modern Theory of Solids
feynman and hibbs Quantum Mechanics and slater Introduction to Chemical Physics
Path Integrals slater Quantum Theory of Atomic Structure,
ginzton Microwave Measurements Vol. I
green Nuclear Physics slater Quantum Theory of Atomic Structure,
gurney Introduction to Statistical Mechanics Vol. II
hall Introduction to Electron Microscopy slater Quantum Theory of Matter
hardy and perrin The Principles of Optics slater Quantum Theory of Molecules and
harnwell Electricity and Electromagnetism Solids, Vol. 1
harnwell and livingood Experimental Atomic slater Quantum Theory of Molecules and
Physics Solids, Vol. 2
henley and thirring Elementary Quantum slater and frank Electromagnetism
Field Theory slater and frank Introduction to Theoretical
Houston Principles of Mathematical Physics Physics
jammer The Conceptual Development of slater and frank Mechanics
Quantum Mechanics smythe Static and Dynamic Electricity
kennard Kinetic Theory of Gases stratton Electromagnetic Theory
lane Superfluid Physics tinkham Group Theory and Quantum Mechanics
leighton Principles of Modern Physics townes and schawlow Microwave Spectros¬
lindsay Mechanical Radiation copy
Livingston and blewett Particle Accelerators white Introduction to Atomic Spectra
The late F. K. Richtmyer was Consulting Editor of the series from its inception in
1929 to his death in 1939. Lee A. DuBridge was Consulting Editor from 1939 to 1946;
and G. P. Harnwell from 1947 to 1954.
The CONCEPTUAL
DEVELOPMENT
of QUANTUM
MECHANICS
MAX JAMMER
Bar-Ilan University, Israel
McGRAW-HILL BOOK COMPANY
New York, St. Louis, San Francisco, Toronto, London, Sydney
GiCj n4.\ . 3 2.£>
The Conceptual Development of Quantum Mechanics
Copyright © 1966 by McGraw-Hill, Inc. All Rights
Reserved. Printed in the United States of America.
This book, or parts thereof, may not be reproduced
in any form without permission of the publishers.
Library of Congress Catalog Card Number 66-17914
1234567890 MP 7321069876
Preface
It is the purpose of this study to trace the conceptual development of quan¬
tum mechanics from its inception to its formulation as a full-fledged theory
of atomic physics, from its status as a rather doubtful ad hoc hypothesis
to that of an imposing intellectual structure of great beauty.
All the great theories in the history of physics—from Aristotelian
mechanics and its medieval elaborations, through Newtonian dynamics
with its Lagrangian or Hamiltonian modifications, to Maxwellian electro¬
dynamics and' Einsteinian relativity—have been subjected repeatedly to
historico-critical investigations, and their conceptual foundations have
been thoroughly analyzed. But no comprehensive scholarly study of the
conceptual development of quantum mechanics has heretofore appeared.
The popular or semiscientific publications available hardly skim the surface
of the subject. And the few, though important, essays on the topic written
by the originators of the theory themselves are mostly confined to a par¬
ticular aspect or to the defense of a specific philosophical position. The
publication of a comprehensive and coherent analysis of the conceptual
development of quantum mechanics, the only consistent theory of atomic
processes, and hence a foundation of modern science, seems therefore to
fill an important lacuna in the literature on the history and philosophy of
physics.
Such a study, however, should not be regarded as an end in itself.
Never before has a theory been treated in so many excellent texts within
so short a period of time. Since every additional text, as is natural in a
developing branch of science, attempts to construct the theory on the basis
of an ever more concise logical structure, the traditional texts presenting
the material in the order of its historical development are gradually losing
ground. Students, it is rightfully claimed, may be saved much trouble “if
Preface
VI
they are not led through all the historical pitfalls, and instead acquainted
from the very beginning with concepts, such as the spin, that cannot be
grasped except by quantum mechanical means.” 1 Admittedly, a good work¬
ing knowledge, even a high standard of efficiency and competence in ap¬
plying the theory to physical problems may be obtained by this method of
instruction. But as long as it is true that “however far the phenomena
transcend the scope of classical physical explanation, the account of all
evidence must be expressed in classical terms,” 2 a profound comprehension
of quantum mechanics requires more than a study of the subject in its
shortest possible logical formulation. “It is impossible to understand the
methods of modern quantum mechanics without a knowledge of the way
in which the theory has been developing.” 3 Indeed, some knowledge of the
dramatic struggle of ideas that preceded the formation of quantum concep¬
tions and of the intricate ways of reasoning that led to the generally ac¬
cepted formulation of the theory is indispensable for a profound compre¬
hension of its physical significance, for an intelligent appreciation of its
philosophical implications, and even for an enlightened understanding of
its logical structure. Duhem’s statement “faire l’histoire d’un principe
physique, c’est en meme temps en faire T analyse logique” is particularly
meaningful for the science of quantum mechanics.
The subject of our discussion may be of interest not only from the
historical and methodological, but also from the purely scientific, point of
view. If the fundamental conceptions of theoretical physics cannot be
extracted from experience alone but are, as Einstein once said, “free in¬
ventions of the human intellect” 4 a study of their formation and its at¬
tendant empirical, mathematical, philosophical, and psychological factors
may well throw some light on the questions of whether the choice of the
actually accepted theoretical scheme was unique and of whether a selection
of other factors, under discussion at the time, could have led to an alterna¬
tive formulation of the theory.
Such conceptual and circumstantial inquiries, of course, do not ex¬
clude the possibility of an irrational residue in the process of scientific
theory construction. If reductions of such irrationalities to their bare
minima form the historical and methodological components of the contents
of a study such as the present, considerations of the kind mentioned before
1 F. A. Kaempffer, Concepts in Quantum 3 A. March, Quantum Mechanics of
Mechanics (Academic Press, New York Particles and Wave Fields (J. Wiley &
and London, 1965), p. v. Sons, New York: Chapman and Hall,
2 Niels Bohr, “Discussion with Einstein London, 1951), p. vi.
on epistemological problems in atomic 4 A. Einstein, The World As I See It,
physics,” in Albert Einstein: Philosopher- translated from Mein Weltbild by A. Harris
Scientist (The Library of Living Philoso¬ (John Lane, The Bodley Head Limited,
phers, Evanston, Illinois, 1949), p. 209. London, 1935), p. 134.