Quantum Mechanics, A Half Century Later: Papers of a Colloquium on Fifty Years of Quantum Mechanics, Held at the University Louis Pasteur, Strasbourg, May 2–4, 1974 PDF
Preview Quantum Mechanics, A Half Century Later: Papers of a Colloquium on Fifty Years of Quantum Mechanics, Held at the University Louis Pasteur, Strasbourg, May 2–4, 1974
QUANTUM MECHANICS, A HALF CENTURY LATER EPISTEME A SERIES IN THE FOUNDATIONAL, METHODOLOGICAL, PHILOSOPHICAL, PSYCHOLOGICAL, SOCIOLOGICAL AND POLITICAL ASPECTS OF THE SCIENCES, PURE AND APPLIED Editor: MARIO BUNGE Foundations and Philosophy of Science Unit, McGill University Advisory Editorial Board: RUTHERFORD ARIS, Chemistry, University of Minnesota DANIEL E, BERLYNE, Psychology, University of Toronto HUBERT M. BLALOCK, Sociology, University of Washington GEORGE BUGLIARELLO, Engineering, Polytechnic Institute of New York NOAM CHOMSKY, Linguistics, MIT KARL W. DEUTSCH, Political science, Harvard University BRUNO FRITSCH, Economics, E.T.H. Zurich ERWIN HIEBERT, History of science, Harvard University ARISTID LINDENMA YER, Biology, University of Utrecht JOHN MYHILL, Mathematics, SUNY at Buffalo JOHN MA YN ARD SMITH, Biology, University of Sussex RAIMO TUOMELA, Philosophy, University of Helsinki VOLUME 5 QU ANTUM MECHANICS, A HALF CENTURY LATER PAPERS OF A COLLOQUIUM ON FIFTY YEARS OF QUANTUM MECHANICS, HELD AT THE UNIVERSITY LOUIS PASTEUR, STRASBOURG, MAY 2-4, 1974 Edited by JOSE LEITE LOPES Universite Louis Pasteur, Strasbourg and MICHEL PATY Centre de Recherches Nucleaires et Universite Louis Pasteur, Strasbourg D. REIDEL PUBLISHING COMPANY DORDRECHT-HOLLAND/BOSTON-U.S.A. Library of Congress Cataloging in Publication Data Colloquium on Fifty Years of Quantum Mechanics, University Louis Pasteur, 1974. Quantum mechanics. (Episteme ; v. 5) Bibliography: p. Includes index. 1. Quantum theory-Congresses. I. Lopes, Jose Leite. II. Paty, Michel, 1938- III. Title. QCI73.96.C64 1974 530.1'2 77-8178 ISBN -13: 978-94-010-1198-3 e-ISBN -13: 978-94-010-1196-9 DOl: 10.1007/978-94-010-1196-9 Published by D. Reidel Publishing Company, P.O. Box 17, Dordrecht, Holland Sold and distributed in the U.S.A., Canada, and Mexico by D. Reidel Publishing Company, Inc. Lincoln Building, 160 Old Derby Street, Hingham, Mass. 02043 U.S.A. All Rights Reserved Copyright © 1977 by D. Reidel Publishing Company, Dordrecht, Holland and copyrightholders as specified on appropriate pages Softcover reprint of the hardcover 1st edition 1977 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any informational storage and retrieval system, without written permission from the copyright owner T ABLE OF CONTENTS FOREWORD VII PREFACE a J. A. WHEELER / Include the Observer in the Wave Function? 1 A. FRENKEL / On the Possible Connections between Quantum Mechanics and Gravitation 19 J. M. JAUCH / The Quantum Probability Calculus 39 G. CASSINELLI and E. G. BELTRAMETTI / Quantum Logics and Ideal Measurements of the First Kind 63 c. PIRON / A First Lecture on Quantum Mechanics 69 s. P. SHUSHURIN / Essay on the Development of the Statistical Theory of the Calculus of Probability 89 M. MUGUR-SCHACHTER / The Quantum Mechanical One- System Formalism, Joint Probabilities and Locality 107 B. D'ESPAGNAT/On Propositions and Physical Systems 147 J.-M. LEVY-LEBLOND / Towards a Proper Quantum Theory 171 D. BOHM and B. HILEY I On the Intuitive Understanding of Non-Locality as Implied by Quantum Theory 207 R. LESTIENNE / Four Ideas of David Bohm on the Relationship between Quantum Mechanics and Relativity 227 R. DAUDEL / The Role of Quantum Mechanics in the Set-up of a Mathematical Government among Molecular Populations 237 G. LOCHAK / Hidden Parameters, Hidden Probabilities 245 M. P AT Y / The Recent Attempts to Verify Quantum Mechanics 261 M. LAMEHI-RACHTI and w. MITTIG / Spin Correlation Measurement in Proton-Proton Scattering and Comparison with the Theories of the Local Hidden Variables 291 INDEX 305 FOREWORD The articles collected in this volume were written for a Colloquium on Fifty Years of Quantum Mechanics which was held at the University Louis Pasteur of Strasbourg on May 2-4, 1974, in commemoration of the original work by De Broglie in 1924. It is our hope that this volume will convey to the reader the idea that quantum mechanics, besides being a fundamental tool for scien tific workers today, is also a source of a number of questions and thoughts about the interpretation of the foundation of quantum mechanics itself. This gives rise to problems of a philosophical and logical character and has repercussions on other domains such as the theory of gravitation. Besides the papers presented at the Colloquium, an article has been included by D. Bohm and B. Hiley. This compensates, perhaps, for the article of S. Kochen, whose manuscript unfortunately did not reach us in time for inclusion in ~his volume. A few months after this Colloquium we learned of the death of Professor Jauch, who had taken a lively and crucial part in its discussions. We have been extremely saddened by the news of his death, and would like to express our long standing indebtedness to him as a physicist. We are grateful to Professor B. d'Espagnat who kindly helped us in organizing the Colloquium meetings and to Professor G. Ourisson who, as President of the Louis Pasteur University, gave us en couragement and support to our enterprise. We would further like to express our thanks to all those who have contributed to the work involved in the Colloquium and the publication of this book, and especially to Dr J. Simmons who agreed to check the English version of several contributions. J. LEITE LOPES M. PATY PREFACE A few years ago, H. Barreau, G. Monsonego, M. Paty and myself organized the Seminar on the Foundations of Science at the U niver sity Louis Pasteur of Strasbourg. Modern society recognizes the importance of science in the world through its technological applications and the multitude of appliances, gadgets and mechanisms which fill and often invade our daily life. Scientists, dominated by the spirit of competition in their respective fields of specialization, often pass too quickly from one interpretation scheme to another and thus may stifle their research work by being over-anxious to publish more and more. It would therefore be beneficial to organize in the universities, parallel to the different specialized seminars on recent experimental work and theoretical models, seminars on the foundation of science, its historical evolution, and the description and genesis of its ideas. That is what we have tried to set up at Strasbourg over the past few years; it is with this motivation that the Conference 'A Half Century of Quantum Mechanics' was organized, and these papers collected and published. It is already fifty years ago that the intuition of De Broglie laid the foundation stone of the theoretical structure that houses the funda mental laws of atomic, nuclear and sub-nuclear phenomena. As everybody knows, some fundamental notions of quantum mechanics put forward by De Broglie himself and by Einstein and Niels Bohr, amongst others, are still open to further discussion. It is true that perhaps a great majority of physicists remain content in calculating the effective cross-sections of collisions and reactions and the energy levels of physical systems etc ... with the help of quantum mechanics. However, others try in addition to examine thoroughly its physical and philosophical significance, and are sometimes led to modify some basic ideas of the theory. Such discussions may indeed contribute to the progress of scientific thought. We hope that this collection of papers which has been x PREFACE requested on the occasion of the 50th anniversary of the thesis of Louis De Broglie, will contribute to that aim. We regret the recent death of Leon Rosenfeld, the eminent physi cist, who was one of the prominent members of the Copenhagen school, and who came several times to Strasbourg to participate in the seminars on the Foundations of Science. Let us dedicate this work to the memory of L. Rosenfeld. J. LEITE LOPES JOHN ARCHIBALD WHEELER* INCLUDE THE OBSERVER IN THE WAVE FUNCTION? ABSTRACT. The classical dynamics of Einstein's closed universe (idealized for simplicity to be empty except as excited by gravitational waves) is analyzed in no way more economically than by the standard Hamilton-Jacobi method. In it the essential ideas are (1) a spacelike 3-geometry, (3)'9; (2) an infinite-dimensional superspace 9', each point (or collection of equivalent points) of which stands for one and only one (3)'9; (3) a Hamilton-Jacobi function S (dimensions of action) or wave-phase S/h (measured in radians) that propagates through superspace, S = S«3)'9), according to the standard Einstein-Hamilton-Jacobi equation of A. Peres; (4) a 'constructive interference' between this family of wave crests and other families of wave crests (obeying the same EHJ equation) that picks out (U. Gerlach) 'Yes' points (constructive interference) in superspace from 'No' points (destructive interference); (5) definition through these 'Yes' points of a 'leaf of history' slicing through superspace; and (6) identification of this leaf of history with a particular spacetime (4)'9 that satisfies Einstein's field equation. Thus, every spacelike slice through this (4)'9 is a 'Yes' (3)'9, and conversely. When one goes from classical theory to quantum theory, one goes from S«3)'9) to ",«3)'9), with the approximate correspondence: '" - (slowly varying amplitude) exp (is/h). When one enriches the content of the theory from pure Einstein geometrodynamics to geometry plus particle-fields and other fields, one still has every degree of freedom of the universe included in the independent variables upon which", depends. Therefore the observer himself would seem to be included in ",. However, so to 'include the observer in' makes insuperable difficulties of principle, which are described. One has to accept that physics never permits a complete prediction, but only a forecast of a correlation between events (E. P. Wigner). One is led to recognize that a wave function 'encompassing the whole universe' is an idealization, formalistically perhaps a con venient idealization, but an idealization so strained that it can be used only in part in any forecast of correlations that makes' physical sense. For making sense it seems essential most of all to 'leave the observer out of the wave function'. 1. PRELIMINARY SURVEY OF THE ISSUE Physics treats everything as a dynamic system, even the universe. Moreover, it describes the state of every dynamic system, not deterministically, but in probability terms, by a state function. Thus the consistent carrying out of the scheme of physics as one under stands it today leaves no alternative but to assign a probability J. Leite Lopes and M. Paty (eds.), Quantum Mechanics. a Half Century Later, 1-18. All Rights Reserved. Copyright © 1977 by D. Reidel Publishing Company. Dordrecht·Holland 2 J. A. WHEELER amplitude to the state of the universe. Yet, Wigner reasons, there is no such thing as the state function of the. universe. A state function is only useful insofar as it describes correlations between observations - and there is no place for any 'observer' to stand 'outside' the universe to observe it. There has to be a wave function for the universe but there can't be a wave function for the universe: that is the dilemma. How does the 'dilemma of a wave function for the universe' arise? Why is it important? What changed view does it suggest of the nature of physics? Geometrodynamics? These issues about the reasonable ness - and unreasonableness - of a 'quantum mechanics of the universe' are of concern today. There is no better occasion to survey them than this 50th anniversary of Louis de Broglie's discovery of the connection between quantum states and waves. 2. THE ISSUE MORE SHARPLY FOCUSSED: DOES SOME RELEVANT FEATURE OF CONSCIOUSNESS FALL OUTSIDE THE DOMAIN OF PHYSICS? The methods of quantum mechanics allow us to treat the machinery of observation. Do they also allow us to analyze the observer? We have no trouble of quantum-mechanics principle to apply the idea of 'wave function' when a particle passes through a cloud chamber. Nor when that particle ionizes a nitrogen molecule. Nor at later stages down the road: ion nucleating droplet; droplet scattering photon; and photon operating phototube. And does the idea of 'probability amplitude' make difficulty for us when the phototube operates a digital display? When a photon from the display enters the eye? When an impulse from the retina passes along the optic nerve? No, and again, no. Then why not also use probability amplitude to describe the state of the consciousness of the observer? In brief, does it make sense to 'include the observer in the wave function'? And if not, why not? No question in physics is the takeoff point for a greater variety of considerations. They range from 'Schrodinger's (1935) cat' and 'Wig ner's (1963) friend' to Everett's 'relative state' or 'many-universes' description of quantum mechanics [Everett (1957, 1973); DeWitt and Graham (1973); Cooper and Van Vechten (1969)] and from the
The list of books you might like
