UNDERGRADUATE TEXTS IN CONTEMPORARY PHYSICS Editors Robert S. Averback Robert C. Hilborn David Peak Thomas Rossing Cindy Schwarz Springer Science+Business Media, LLC UNDERGRADUATE TEXTS IN CONTEMPORARY PHYSICS Cassidy, Holton, and Rutherford, Understanding Physics Enns and McGuire, Computer Algebra Recipes: A Gourmet's Guide to the Mathematical Models of Science Hassani, Mathematical Methods: For Students of Physics and Related Fields Hassani, Mathematical Methods Using Mathematica®: For Students of Physics and Related Fields Ho/brow, Lloyd, and Amato, Modern Introductory Physics Moller, Optics: Learning by Computing, with Examples Using Math cad® Roe, Probability and Statistics in Experimental Physics, Second Edition Rossing and Chiaverina, Light Science: Physics and the Visual Arts LIGHT SCIENCE Physics and the Visual Arts Thomas D. Rossing Christopher J. Chiaverina With 225 Illustrations Thomas D. Rossing Christopher J. Chiaverina Department of Physics Science Department Northern Illinois University New Trier High School De Kalb, IL 60115 Winnetka, IL 60093 USA USA Series Editors Robert S. Averback Thomas D. Rossing Department of Materials Science Department of Physics University of Illinois Northern Illinois University Urbana, IL 61801 De Kalb, IL 60115 USA USA Robert C. Hilborn Cindy Schwarz Department of Physics Department of Physics and Astronomy Amherst College Vassar College Amherst, MA 01002 Poughkeepsie, NY 12601 USA USA David Peak COVER PHOTOGRAPH: “Evolution of a Splash” by Department of Physics Loren M. Winters. A drop falling into a pool formed Utah State University by the previous drop is illuminated by four photoflash Logan, UT 84322 guns of different colors triggered at 3-millisecond USA intervals (see Plate 10.3). Library of Congress Cataloging-in-Publication Data Rossing, Thomas D., 1929– Light science : physics and the visual arts / Thomas D. Rossing, Christopher J. Chiaverina. p. cm.—(Undergraduate texts in contemporary physics) Includes bibliographical references and index. ISBN 978-1-4419-3169-6 ISBN 978-0-387-21698-0 (eBook) DOI 10.1007/978-0-387-21698-0 1. Light. 2. Color. I. Chiaverina, Christopher. II. Title. III. Series. QC358.R68 1999 535—dc21 99-18390 Printed on acid-free paper. © 1999Springer Science+Business Media New York Originally published by Springer-Verlag New York, Inc. 1999 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC ), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use of general descriptive names, trade names, trademarks, etc., in this publication, even if the for- mer are not especially identified, is not to be taken as a sign that such names, as understood by the Trade Marks and Merchandise Marks Act, may accordingly be used freely by anyone. 9 8 7 6 5 4 3 2 1 To our parents, who nurtured a love of nature, light, and beauty, and the curiosity to observe and experiment; to our wives, Dolores and Bobbi, who endured temporary widowhood; and to our students and colleagues, who provided us with feedback throughout the project. By stylizing the title of this book, artist Scott Kim has created a title that reads the same upside down. Such words or phrases are called “ambigrams.” More ambigrams appear on page 302. Preface The title of this book, Light Science, can take on several meanings. First, it is intended to be an introduction to the science of light, especially intended for students in the visual arts and for readers with an interest in art. Sec- ond, it means that the book emphasizes the phenomena of light rather than the mathematical theories of light (the opposite of “heavy science,” in other words). Third, it suggests a light-hearted approach to science, which the authors have tried to follow. The study of science, after all, is supposed to be fun. Occasionally we discuss phenomena or theories of light in greater depth than usual (“middle-weight science,” you might say). These sections are enclosed in boxes, and some readers (or instructors) may choose to skip them. If some sections are a little more difficult for you to understand than others, skip them at first reading and come back to them; they may seem easier at second reading. The close relationship between science and the arts has always been a special interest of both authors. Visual art depends on light to communi- cate with its intended audience, and an understanding of light and color by both the artist and the viewer will (hopefully) enhance this communication and may improve the quality of the art itself. We would like to hope that this is a course that Monet and Renoir would have enjoyed, just as we en- joy their exquisite paintings. This material in this book was originally designed for an introductory course in physics for students having an interest in the visual arts. We have used it in both high school and university classes. It demands no previous training or experience in physics or mathematics beyond that of high school algebra. When used in its entirety, it is appropriate for a one-semester col- vii viii PREFACE lege course. Many chapters are “stand-alone” chapters, and can be used as supplemental material for courses in physics, art, or psychology. We are great believers in hands-on learning. In each chapter we suggest simple experiments for the reader to do with simple equipment at home or which can be demonstrated in class. Laboratory experiments are in Ap- pendix J. We hope that most readers will do these experiments, whether or not a scheduled laboratory is part of the course. Each chapter includes the following: summary, references, glossary, re- view questions, questions for thought and discussion, exercises, and exper- iments for home, laboratory, and classroom demonstration. The authors wish to thank Sandra Whipple and Jill O’Leske for their help with the artwork. Thomas D. Rossing Christopher J. Chiaverina Contents Preface vii 1 Our World of Light and Color 1 1.1 Rainbows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Blue Skies and Red Sunsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.3 Why Clouds Are White . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.4 The Color of Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.5 Green Leaves of Summer, Crimson Leaves of Autumn . . . . . . . . . 7 1.6 What Is Color? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.7 Mixing Colors by Addition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.8 Mixing Colors by Subtraction . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.9 Color in Art . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1.10 Shadows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.11 Pinhole Camera . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.12 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2 The Mystery of Light 23 2.1 The Nature of Light: Particles or Waves? . . . . . . . . . . . . . . . . . . 23 2.2 Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2.3 Progressive Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.4 Impulsive Waves: Reflection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.5 Superposition and Interference . . . . . . . . . . . . . . . . . . . . . . . . . . 29 2.6 Standing Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2.7 Electromagnetic Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2.8 Speed of Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2.9 The Particle Nature of Light: Observing Photons . . . . . . . . . . . . 34 2.10 Wave Propagation in Two and Three Dimensions . . . . . . . . . . . . 35 ix