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1 Einstein Relatively Simple Downloaded from EINSTEIN RELATIVELY SIMPLE Our Universe Revealed in Everyday Language

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3 Einstein Relatively Simple Downloaded from EINSTEIN RELATIVELY SIMPLE Our Universe Revealed in Everyday Language Ira Mark Egdall World Scientific NEW JERSEY LONDON SINGAPORE BEIJING SHANGHAI HONG KONG TAIPEI CHENNAI

4 Published by World Scientific Publishing Co. Pte. Ltd. 5 Toh Tuck Link, Singapore USA office: 27 Warren Street, Suite , Hackensack, NJ UK office: 57 Shelton Street, Covent Garden, London WC2H 9HE Einstein Relatively Simple Downloaded from Library of Congress Cataloging-in-Publication Data Egdall, Ira Mark, author. Einstein relatively simple : our universe revealed in everyday language / Ira Mark Egdall. pages cm Includes bibliographical references and index. ISBN (hard : alk. paper) -- ISBN (pbk) 1. Einstein, Albert, Influence. 2. Relativity (Physics) I. Title. QC16.E5E dc British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. Copyright 2014 by World Scientific Publishing Co. Pte. Ltd. All rights reserved. This book, or parts thereof, may not be reproduced in any form or by any means, electronic or mechanical, including photocopying, recording or any information storage and retrieval system now known or to be invented, without written permission from the Publisher. For photocopying of material in this volume, please pay a copying fee through the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA. In this case permission to photocopy is not required from the publisher. In-house Editor: Rhaimie Wahap Typeset by Stallion Press enquiries@stallionpress.com Printed in Singapore

5 Einstein Relatively Simple Downloaded from To the memory of my father, who taught me to appreciate the wonders of science. To the memory of my mother, who taught me to see beauty in the world.

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About the Author Einstein Relatively Simple Downloaded from www.worldscientific.

7 About the Author Einstein Relatively Simple Downloaded from IRA MARK EGDALL Einstein Relatively Simple Ira Mark Egdall is the author of the ebook Unsung Heroes of the Universe and a popular science writer for DecodedScience.com. He is a retired aerospace program manager with an undergraduate degree in physics from Northeastern University. Mark now teaches lay courses in modern physics at Lifelong Learning Institutes at Florida International University, the University of Miami, and Nova Southeastern University. He also gives entertaining talks on Einstein and time travel. When not thinking about physics, Mark spends his time playing with his grandchildren and driving his wife of 45 years crazy. vii

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9 Prologue Einstein Relatively Simple Downloaded from All knowledge begins in wonder. Aristotle In June of 1905, former high-school drop-out and lowly patent clerk Albert Einstein published a paper in the German Annals of Physics which revolutionized our understanding of space and time. What came to be known as the theory of special relativity predicted a strange new universe where time slows and space shrinks with motion. In that same journal, Einstein proposed light comes in discreet packets of energy we now call photons. Along with Max Planck s work, this insight sparked the quantum revolution. This in turn set off the greatest technological revolution in human history enabling the invention of television, transistors, electronic digital computers, cell phones, digital cameras, lasers, the electron microscope, atomic clocks, MRI, sonograms, and many more modern-day devices. Einstein s follow-up article in September of 1905 proposed that mass and energy are equivalent. His famous equation, E = mc 2, came to solve one of the great mysteries of modern science how the Sun and stars shine. Some four decades later, Einstein s breakthrough ushered in the atomic age. In December of 1915, Albert Einstein now Professor of Theoretical Physics at the University of Berlin surpassed his already staggering ix

10 Einstein Relatively Simple Einstein Relatively Simple Downloaded from accomplishments. In the midst of the turmoil and hardships of World War I, he produced his life s masterpiece: a new theory of gravity. His audacious general theory of relativity revealed a cosmos beyond our wildest imagination. It predicted phenomena so bizarre even Einstein initially doubted their existence black holes which trap light and stop time, wormholes which form gravitational time machines, the expansion of space itself, and the birth of the universe some 13.8 billion years ago in the ultimate cosmic event: the Big Bang. Not since Isaac Newton had a single physicist attained such monumental breakthroughs, and no scientist since has matched his breathtaking achievements. In recognition, TIME magazine selected Albert Einstein above such luminaries as Franklin Delano Roosevelt and Mohandas Gandhi, as the Person of the Century the single individual with the most significant impact on the 20 th century. Albert Einstein has long since passed from this corporal world. Yet his fame lives on. His discoveries inspire today s generation of physicists providing stepping stones to a new understanding of the cosmos and perhaps someday a unified theory of all physics. His brilliance, independence of mind, and persistence continue to be an inspiration to us all. He remains the iconic figure of science, whose genius transcends the limits of human understanding. I wrote Einstein Relatively Simple to tell Einstein s story to hopefully provide the non-expert a clear, step-by-step explanation of how he came to develop both special and general relativity. My goal is a book which is comprehensive, fun to read, and most important, understandable to the lay reader. With this in mind, the book emphasizes the concepts behind Einstein s theories rather than the mathematics. Analogies and real-life examples serve to illuminate their mind-bending implications. Fanciful stories, from talking particles to alien abductions, offer comic relief while providing a setting for understanding the physics. I first introduce Einstein the man and then ease into the core tenets of relativity. I feel that understanding the history behind the science as well as how a scientist thinks helps us comprehend his theories. The book also cites key historical experiments which confirm predictions of relativity to help the reader accept Einstein s counterintuitive ideas. Einstein Relatively Simple is based on lay courses in modern physics I teach at Lifelong Learning Institutes at several universities in South Florida. x

11 Prologue Einstein Relatively Simple Downloaded from My students come from all walks of life. Most have no prior background in physics or mathematics. Can a non-expert really understand Einstein s theories, at least at some level? My teaching experience says yes. After all, you don t have to be an artist to appreciate the beauty of a Michelangelo you just need to be able to see. You don t need to be a musician to feel the majesty of a Beethoven symphony you just need to be able to hear. And I believe you do not have to be a trained physicist to appreciate the beauty and grandeur of Einstein s theories you just need to be able to think. It is my hope that scientists, engineers, mathematicians, and others in the technology field, as well as educators and undergraduate physics majors (especially those studying relativity for the first time) will also find this book enlightening. The conceptual approach and history of relativity s development presented in Einstein Relatively Simple should help crystallize fundamental principles. Why yet another popular science book on relativity? I have read over 80 popular science books on modern physics, yet have had great difficulty finding a book on relativity which is thorough and at a level my lay students can understand particularly general relativity. Most popular science books give general relativity short shrift or ignore the subject all together. It is also my hope that Einstein Relatively Simple fills this gap in the current literature. The book is structured on several levels: The text itself Explains basic concepts through analogies and stories with minimal to no mathematics. Grey-shaded areas within the text Provides high-school level mathematical details. (The reader may skip these grey areas, and still get the core message of each concept.) Appendices Expands upon key topics. (Sometimes involves basic calculus.) Endnotes Provides additional material for those gluttons for punishment who wish to delve more deeply into the history, physics, and supporting mathematics. (Sometimes involves basic calculus.) So come explore how an unknown patent clerk came to develop a new theory of time and space, how he came to supplant the illustrious xi

12 Einstein Relatively Simple Downloaded from Einstein Relatively Simple Isaac Newton with a new theory of gravity. Along the way we will examine the mind of Albert Einstein, who preferred to think in pictures rather than words, follow his thinking, his logic, and his insights. To quote one of my students; You ll never look at the universe the same way again! xii

13 Contents Einstein Relatively Simple Downloaded from About the Author Prologue PART I Einstein Discovered: Special Relativity, E = mc 2, and Spacetime 1 Chapter 1 From Unknown to Revolutionary 3 Chapter 2 The Great Conflict 15 Chapter 3 The Two Postulates 35 Chapter 4 A New Reality 47 Chapter 5 The Shrinking of Time 57 Chapter 6 Simultaneity and the Squeezing of Space 67 Chapter 7 The World s Most Famous Equation 83 Chapter 8 Spacetime 109 PART II Einstein Revealed: General Relativity, Gravity, and the Cosmos 137 vii ix Chapter 9 Einstein s Dream 139 Chapter 10 The Happiest Thought of My Life 151 Chapter 11 The Warping of Space and Time 173 Chapter 12 Stitching Spacetime 187 Chapter 13 What is Spacetime Curvature? 195 Chapter 14 Einstein s Masterpiece 215 xiii

14 Einstein Relatively Simple Chapter 15 The Universe Revealed 231 Chapter 16 In the Beginning 249 Einstein Relatively Simple Downloaded from Epilogue 269 Appendix A 279 Appendix B 285 Appendix C 291 Appendix D 295 Appendix E 297 Acknowledgements 303 Notes with Sources 305 Figure Credits 359 Also by Ira Mark Egdall 363 Further Reading 365 Index 367 xiv

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Nuclear Chemistry. Principles of. Principles of Nuclear Chemistry Downloaded from Principles of Nuclear Chemistry Essential Textbooks in Chemistry ISBN: 2059-7738 Orbitals: With Applications in Atomic Spectra by Charles Stuart McCaw Principles of Nuclear Chemistry by Peter A C McPherson