The Story of Quantum Mechanics

355 Pages·1968·29.932 MB·English

by  Victor Guillemin

The Story of
QUANTUM
MECHANICS
Victor Guillemin
Drawings by Robert Guillemin
Dover Publications, Inc.
Mineola, New York
Copyright
e
Copyright 1968 by Victor Guillemin
All rights reserved.
Bibliographical Note
This Dover edition, first published in 2003, is an unabridged republication of
the work originally published by Charles Scribner's Sons, New York, in 1968.
Victor Guillemin, one of the author's sons, has written a new Foreword espe
cially for the Dover edition.
Library 0/ Congress Cataloging-in-Publication Data
Guillemin, Victor, 1896-1985.
The story of quantum mechanics I Victor Guillemin ; drawings by Robert
Guillemin.
p. ern.
Originally published: New York : Scribner, 1968.
Includes bibliographical references and index.
ISBN 0-486-42874-5 (pbk.)
1. Quantum theory. 2. Science-Philosophy. 1. Title.
QCI74.12.G854 2003
530.12--dc21
2003043777
Manufactured in the United States of America
Dover Publications. Tnc., 31 East 2nd Street, Mineola, N.Y. 11501
TO TED KEMBLE, MENTOR
Foreword to the Dover Edition
My FATHER, Victor Guillemin (who died in
1985) was born in Milwaukee in 1896. He
got his B.A. in physics from the University
of Wisconsin in 1923 and his M.A. from
Harvard in 1924. While a graduate student
at Harvard, he won a Sheldon fellowship
to study in Munich with Arnold Sommer
feld at the Institut fUr theoretische Physik;
he wrote his doctoral thesis under Sommer
feld's supervision in 1926. Thus he had the
good fortune to be present at the birth of
quantum mechanics: Werner Heisenberg
and many of the other major players in the
HUTCHINS PH01'OCIW"IIY, INC. future development of this subject. like
Linus Pauling and Hans Bethe. were in Munich in the years my father was
there, and, in fact, Heisenberg wrote his thesis with Sommerfeld the same
year my father did. (1 should mention that many of the anecdotes in The
Story of Quantum Mechanics were witnessed firsthand during this stay in
Munich.)
In the late 1920s my father wrote several well-regarded papers on quan
tum mechanics. However. in the 1930s he moved from physics to bio
physics and spent most of his life working in experimental biophysics at
Wright-Patterson Air Force base in Dayton. Ohio, and at the University of
Illinois College of Medicine. On his retirement. he was asked to head up
a program at Harvard whose purpose (this was just at the beginning of the
post-sputnik era) was to give high-school teachers a chance to spend a
year in the Harvard physics environment retooling and acquiring some
familiarity with recent developments. This. I think, led him to revisit the
experiences of his years in Munich and write The Story of Quantum
Mechanics.
VICTOR GUILLEMIN
Department of Mathematics
Massachusetts Institute of Technology
v
Preface
PHYSICAL science, which is concerned with explaining what
the universe is made of, how it is put together and how it works,
has achieved two major advances in our century. One is the theory
of relativity; the other is quantum mechanics. The former has
somehow captured the popular fancy; and its founder, Albert
Einstein, is known throughout the world. But the names of those
who developed quantum mechanics are not nearly so current out
side scientific circles; and what they accomplished is largely
unknown to the general public. Yet quantum mechanics consti
tutes a deep and fundamental revision of the older classical laws
of physics and presents a surprising new picture of the composi
tion and the workings of the universe in which we· live.
The province of quantum mechanics, the "new physics" as it
has been called, is the sub-microscopic realm of atoms, the tiny
entities of which all material substance is composed. Although
this atomic substratum is not immediately apparent to our senses,
its activities exert their eHects upon many phenomena that can be
observed. They influence the course of events in the remote stars
of the heavens, in our earthly environment, in all living creatures,
including ourselves.
When, in the early years of our century, physicists first devel
oped new experimental techniques for investigating the structure
and activity of atoms, it soon became apparent that the laws of
nature which had been developed while dealing with familiar
vii
viii PREFACE
things that could be seen and handled were not adequate to
explain the new findings. Novel concepts and theories had to be
developed; and these were so surprising, so contrary to seemingly
seH-evident tenets, that they came to be accepted only reluctantly
under the force of convincing experimental evidence.
To tell of the ways in which the ingenious new experiments in
atomic physics were devised, what they revealed, and how this
new lmowledge was futally accounted for after much hard work,
many tentative hypotheses and a few brilliant flashes of insight
this is the story of quantum mechanics.
The subject matter of this book falls naturally into four divi
sions. Chapters 1 through 5 are introductory. They trace the
development of physics, primarily of ideas regarding the nature
of matter and of light, from antiquity through the period of classi
cal science in the seventeenth, eighteenth and nineteenth cen
turies, and on into the first two decades of the twentieth. Chapters
6 through 8 explain how quantum mechanics then developed from
what had gone before, how it coped with previously unsolved
problems and how it gave an excellent acco~t of all observable
atomic phenomena. Chapters 9 through 14 are devoted to matters
which are presently at the forefront of research, matters pertaining
to the "elementary particles," presumably the ultimate constitu
ents of atoms and thus of all material things. Finally, in Chapters
15 through 18, the concepts of physical science, both the old and
the new, are brought to bear on questions, some of ancient origin,
in the realm of philosophy and religion. 1n these discussions, the
controversial ideas of causality, determinism and free will, are
given careful consideration.
I had the good fortune of attending the lnstitut fUr theoretische
Physik at the University of Munich at the time when quantum
mechanics was in its early stages of development. There the
seminar of Professor Arnold Sommerfeld, a leading figure in
theoretical physics, was attracting a group of scientists doing
research in this new field. My association with this work engen
dered an enduring interest which has led, after many years, to the
writing of this book. It is the consequence of innumerable discus
sions, both formal and informal, of hundreds of lectures attended
and other hundreds delivered, of reading books and scientific
journals, and, in no small measure, of many years given to the
PREFACE ix
teaching of physics during which numerous ideas were sharpened
and clarified by the searching questions of my students.
It is thus impossible for me to acknowledge all the sources from
which I have drawn. Some of the more recent books and articles
which I have consulted are referred to specifically at appropriate
points in the text and others are listed in the annotated bibli
ography.
High praise is due my wife who typed and retyped the various
rewritings of the manuscript with great patience and contributed,
by many sma)) changes, to its smooth readability. Any gaucheries
that remain are, of course, my own.
This book is intended to be read by those who, though lacking
formal training in science or mathematics, maintain a lively inter
est in the ways by which scientists are probing the workings of
nature. It is written to convey sound factual information, some
of which may well be found surprising. Beyond the presentation
of scientific facts, concepts and theories I have tried to convey a
feeling for the ways in which professional scientists work and
think.
Finally, I confess that I wrote the book because I enjoyed doing
it. I can but hope that my readers will obtain their share of pleas
ure in becoming aware of its contents.
Contents
1 THE SCIENCE OF MOTION 3
Newtonian Mechanics, 4
The Experimental-Deterministic Philosophy, 8
The Twentieth Century, 9
2 THE HISTORY OF ATOMISM 13
Origins of the Atomic Concept, 13
The Chemical Atoms,14
The Molecules of the Physicists, 17
The Coming of the Atomic Age, 19
3 ATOMIC STRUCTURE 24
Size, Mass and Motion, 24
Discovery of the Electron, 26
The Atom Models of Thomson and Rutherford, 29
The Bohr Atom Model,34
4 RADIANT ENERGY 40
Light Waves, 40 P4-~
Interference of Light Waves, 46
Light Particles, 48
The Bohr Theory of Atomic Radiation, 55
xii CONTENTS
5 CONSEQUENCES OF THE WAVE-PHOTON
CONCEPT 61
Waves and Particles, 61
Causality and Probability, 66
6 MATTER WAVES 70
ANew Mechanics, 70
Particles and Waves, 79
Waves and Atoms, 81
7 THE PRlNCIPLE OF UNCERTAINTY 91
Wave Packets, 91
Precision of Measurement, 95
Further Implications of Quantum Mechanics, 101
8 APPLICATIONS AND CONCLUSIONS 103
The Particle in a Box, 103
Natural Radioactivity, 108
The Solid State, 114
Seeing with de Broglie Waves, 117
Out of the Atomic Substrat:Jm, 118
9 ELEMENTARY PARTICLES 120
Transmutation of Elements, 120
Particles and More Particles, 125
Discovering Particles, 127
Particle Accelerators, 130
Studying Particles, 136
10 ORGANIZATION OF PARTICLES 139
A Table of Particles, 139
The Leptons, 141
The Mesons, 144
The Baryons, 144
Antiparticles, 145