Alice In Quantumland: An Allegory Of Quantum Physics

Alice in Quantumland AN ALLEGORY OF QUANTUM PHYSICS Alice in Quantumland Robert Gilmore COPERNICUS AN IMPRINT OF SPRINGER-VERLAG © 1995 Springer-Verlag New York, Inc. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Published in the United States by Copernicus Books, an imprint of Springer-Verlag New York, LLC by arrangement with Birkhauser Boston. A member of Springer Science+Business Media Copernicus Books 37 East 7th Street New York, NY 10003 www.copernicusbooks.com Library of Congress Cataloging-in-Publication Data Gilmore, Robert, 1938Alice in Quantumland : an allegory of quantum physics / Robert Gilmore p. cm. Includes bibliographical references and index. ISBN 0-387-91495-1 (acid-free paper) 1. Quantum theory- Fiction. I. Title PS3557.14595A45 1995 813 x.54- dc20 95-10163 Manufactured in the United States of America. Printed on acid-free paper. 19 18 17 16 15 14 13 12 11 ISBN 0-387-91495-1 SPIN 10992432 Preface n the first half of the twentieth century, our understanding of the Universe was turned upside down. The old classical theories of physics were replaced by a new way of looking at the world-quantum mechanics. This is in many ways at variance with the ideas of the older Newtonian mechanics; indeed, in many ways it is at variance with our common sense. Nevertheless, the strangest thing about these theories is their extraordinary success in predicting the observed behavior of physical systems. However nonsensical quantum mechanics may at times appear to us, that seems to be the way that Nature wants it-and so we have to play along. This book is an allegory of quantum physics, in the dictionary sense of "a narrative describing one subject under the guise of another." The way that things behave in quantum mechanics seems very odd to our normal way of thinking and is made more acceptable when we consider analogies to situations with which we are familiar, even though the analogies may be inexact. Such analogies can never be very true to reality as quantum processes are really quite different from our normal experience. An allegory is an extended analogy, or series of analogies. As such, this book follows more in the footsteps of Pilgrim's Progress or Gulliver's Travels than of Alice in Wonderland. "Alice" appears the more suitable model, however, when we examine the world that we inhabit. The Quantumland in which Alice travels is rather like a theme park in which Alice is sometimes an observer, while sometimes she behaves as a sort of particle with varying electric charge. This Quantumland shows the essential features of the quantum world: the world that we all inhabit. Much of the story is pure fiction and the characters are imaginary, although the "real-world" notes described below are true. Throughout the narrative you will find many statements that are obviously nonsensical and quite at variance with common sense. For the most part these are true. Neils Bohr, the father figure of quantum mechanics in its early days, is said to have remarked that anyone who did not feel dizzy when thinking about quantum theory had not understood it. Seriously, Though . . . The description of the world that is given by quantum mechanics is undoubtedly interesting and remarkable, but are we seriously expected to believe that it is true? Amazingly, we find that we must. To underline this assertion, throughout this book you will find brief notes which emphasize the importance of quantum mechanics in the real world. The notes look like this: There are also some longer, end-of-chapter, notes. These amplify some of the trickier points in the text and are denoted thus: See end-of-chapter note 1 Much of th