Science in the Looking Glass: What Do Scientists Really Know?

1 " fm " — 2003/6/2 — page iv — #4 3 Great Clarendon Street, Oxford ox2 6dp Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide in Oxford New York 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, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above You must not circulate this book in any other binding or cover and you must impose this same condition on any acquirer A catalogue record for this title is available from the British Library Library of Congress Cataloging in Publication Data (Data available) Preface Almost every month some book or television programme describes exciting developments in cosmology or fundamental physics. Many tell us that we are on the verge of finding the explanation for the Big Bang or the ultimate Theory of Everything. These will explain all physics in one fundamental set of mathematical equations. It is easy to be swept along by the obvious enthusiasm of the participants, particularly when they are making real progress in pushing back the boundaries of knowledge. Unfortunately, most of their brilliant new ideas are doomed to be forgotten, if only because they cannot all be right. Consider the currently fashionable idea that our universe is just one of many unobservable, parallel universes, all equally real. How can one hope to describe the inner structures of such universes, each with its own values of the 'fundamental' constants? Many may be dull and featureless, but others are presumably as fascinating and complex as our own. However much some physicists declare the reality of these other universes, in practice their main function is to support the mathematical models of the day, or to 'explain' certain properties of our own universe. My goal in this book is not to adjudicate on the correctness of such new and speculative theories. We will instead consider the development of science in a historical context, in order to find out how such questions have been resolved in the past, …