What Science Is And How It Works

WHAT SCIENCE IS AND HOW IT WORKS This page intentionally left blank WHAT SCIENCE IS AND HOW IT WORKS GREGORY N. DERRY PRINCETON UNIVERSITY PRESS PRINCETON, NEW JERSEY Copyright  1999 by Princeton University Press Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, Chichester, West Sussex All Rights Reserved. Library of Congress Cataloging-in-Publication Data Derry, Gregory Neil, 1952– What science is and how it works / Gregory N. Derry. p. cm. Includes bibliographical references and index. ISBN 0-691-05877-6 (cloth : alk. paper) 1. Science. I. Title. Q158.5.D47 1999 500—dc21 99-17186 CIP This book has been composed in Sabon The paper used in this publication meets the minimum requirements of ANSI/NISO Z39.48-1992 (R1997) (Permanence of Paper) http://pup.princeton.edu Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 To Paula and Rebecca This page intentionally left blank CONTENTS PREFACE ix PROLOGUE What Is Science? 3 PART I. EXPLORING THE FRONTIERS OF SCIENCE: HOW NEW DISCOVERIES ARE MADE IN THE SCIENCES 9 CHAPTER 1 A Bird’s Eye View: The Many Routes to Scientific Discovery 11 CHAPTER 2 Nature’s Jigsaw: Looking for Patterns As a Key to Discovery 26 CHAPTER 3 New Vistas: Expanding Our World with Instrumentation 35 CHAPTER 4 Close, But No Cigar: Discrepancies As a Trigger to Discovery 42 CHAPTER 5 Ingredients for a Revolution: Thematic Imagination, Precise Measurements, and the Motions of the Planets 52 PART II. MENTAL TACTICS: SOME DISTINCTIVELY SCIENTIFIC APPROACHES TO THE WORLD 67 CHAPTER 6 A Universe in a Bottle: Models, Modeling, and Successive Approximation 69 CHAPTER 7 Thinking Straight: Evidence, Reason, and Critical Evaluation 89 CHAPTER 8 The Numbers Game: Uses of Quantitative Reasoning 107 PART III. LARGER QUESTIONS: THE CONTEXT OF SCIENCE 123 CHAPTER 9 Ultimate Questions: Science and Religion 125 viii CONTENTS CHAPTER 10 More Practical Questions: Science and Society 133 CHAPTER 11 Difficult and Important Questions: Science, Values, and Ethics 145 CHAPTER 12 Questions of Authenticity: Science, Pseudoscience, and How to Tell the Difference 158 CHAPTER 13 Contentious Questions: The Shadowy Borderlands of Science 174 CHAPTER 14 Very Abstract Questions: The Philosophy of Science 189 CHAPTER 15 Questions of Legitimacy: The Postmodern Critique of Science 207 PART IV. COMMON GROUND: SOME UNIFYING CONCEPTS IN THE SCIENCES 215 CHAPTER 16 Fleas and Giants: Some Fascinating Insights about Area, Volume, and Size 217 CHAPTER 17 The Edge of the Abyss: Order and Disorder in the Universe 230 CHAPTER 18 Riding Blake’s Tiger: Symmetry in Science, Art, and Mathematics 252 CHAPTER 19 The Straight and Narrow: Linear Dependence in the Sciences 274 CHAPTER 20 The Limits of the Possible: Exponential Growth and Decay 285 CHAPTER 21 In the Loop: Feedback, Homeostasis, and Cybernetics 295 EPILOGUE So, What Is Science? 303 INDEX 305 PREFACE S CIENCE, like many other topics, is much more interesting if it makes sense to you. I wrote this book because science is extraordinarily interesting to me, and I want to share that interest with other people. My goal for the book is to convey the foundations of my own understanding of science, which I have acquired over an extended period of time. Scholars argue over whether science is a body of knowledge, a collection of techniques, a social and intellectual process, a way of knowing, a strictly defined method, and so forth. These arguments are not very interesting to me, since I accept all of these elements as v