w U.S. $26.95/Canada $32.00 A fascinating exploration of the science of the impossible—from death rays and force fields to invisibility cloahs— reuealing to what entent such technolo­ gies might be achieuable decades or millennia into the future ne hundred years ago, scientists would have said that lasers, televisions, and the atomic O bomb were beyond the realm of physical possibility. In Physics of the Impossible, the renowned physicist Michio Kaku explores to what extent the technologies and devices of science fiction that are deemed equally impossible today might well become commonplace in the future. From teleportation to telekinesis, Kaku uses the world of science fiction to explore the fundamen­ tals—and the limits—of the laws of physics as we know them today. He ranks the impossible technolo­ gies by category—Class I, II, and III—depending on when they might be achieved, within the next cen­ tury, millennia, or perhaps never. In a compelling and thought-provoking narrative, he explains: • How the science of optics and electromagnetism may one day enable us to bend light around an object, like a stream flowing around a boulder, making the object invisible to observers "down­ stream" • How ramjet rockets, laser sails, antimatter en­ gines, and nanorockets may one day take us to the nearby stars • How telepathy and psychokinesis, once consid­ ered pseudoscience, may one day be possible using advances in MRI, computers, supercon­ ductivity, and nanotechnology • Why a time machine is apparently consistent with the known laws of quantum physics, although it would take an unbelievably advanced civiliza­ tion to actually build one (continued from front flap) Kaku uses his discussion of each technology as a jumping-off point to explain the science behind it. An extraordinary scientific adventure, Physics of the Impossible takes readers on an unforgettable, mes­ merizing journey into the world of science that both enlightens and entertains. ftllCHIO KAKU is the Henry Semat Professor of Theoretical Physics at the Graduate Center of the City University of New York. He is the cofounder of string field theory. He has written several books, including Parallel Worlds and Beyond Einstein, and his bestseller, Hyperspace, was voted one of the best sci­ ence books of the year by the New York Times and the Washington Post. He is a frequent guest on national TV, and his nationally syndicated radio program is heard in 130 cities. He lives in New York City. wuuuu.mkahu.org iAiwiAi.doubleday.com Jacket design by Annabelle Bronstein Jacket photograph by David A. Hardy/Science Photo Library Author photograph by Andrea Brizzi Printed in the U.SA. ADUANCE PRAISE FOR PHYSICS OF THE IMPOSSIBLE "A genuine tour de force, skillfully delivering cogent descriptions of everything from subatomic structure to the laws of the universe." —KIRKUS REVIEWS (starred) CRITICAL ACCLAIM FOR PARALLEL WORLDS "A wonderful tour, with an expert guide, of a cosmos whose comprehension forces us to stretch to the very limits of imagination." —Brian Greene, author of THE FABRIC OF THE COSMOS "A highly readable and exhilarating romp through the frontiers of cosmology." —Martin Rees, author of OUR COSMIC HABITAT and OUR FINAL CENTURY "A roller-coaster ride through the universe—and beyond—by one of the world's finest science writers." —Paul Davies, Australian Centre for Astrobiology, Macquarie University, Sydney, and author of HOW TO BUILD A TIME MACHINE CRITICAL ACCLAim FOR HVPERSPÛCE "One of the best popular accounts of higher physics." —Jim Holt, WALL STREET JOURNAL "Among the best of the genre to appear in recent years . What a wonderful adventure it is." —NEW YORK TIMES BOOK REVIEW "Mesmerizing . the reader exits dizzy, elated, and looking at the world in a literally revolutionary way." —WASHINGTON POST BOOK WORLD PHYSICS OF THE IMPOSSIBLE Other books by Michio Kaku PARALLEL WORLDS EINSTEIN'S COSMOS VISIONS HYPERSPACE BEYOND EINSTEIN i p /PS I IIP A SCIENTIFIC EXPLORATION INTO THE WORLD OF PHASERS, FORCE FIELDS, TELEPORTATION, AND TIME TRAVEL Doubleday NEW YORK LONDON TORONTO SYDNEY AUCKLAND PUBLISHED BY DOUBLED AY Copyright © 2008 by Michio Raku All Rights Reserved Published in the United States by Doubleday, an imprint of The Doubleday Broadway Publishing Group, a division of Random House, Inc., New York. www.doubleday.com DOUBLEDAY and the portrayal of an anchor with a dolphin are registered trademarks of Random House, Inc. Library of Congress Cataloging-in-Publication Data Raku, Michio. Physics of the impossible : a scientific exploration into the world of phasers, force fields, teleportation, and time travel / Michio Raku. -1st ed. p. cm. Includes bibliographical references and index. 1. Physics-Miscellanea. 2. Science-Miscellanea. 3. Mathematical physics- Miscellanea. 4. Physics in literature. 5. Human-machine systems. I. Title. QC75.R18 2008 530-dc25 2007030290 ISBN 978-0-385-52069-0 PRINTED IN THE UNITED STATES OF AMERICA 13579 10 8642 First Edition To my loving wife, Shizue, and to Michelle and Alyson Preface ix Acknowledgments xix Port I: Class I Impossibilities 1 : Force Fields 3 2: Invisibility 16 3: Phasers and Death Stars 34 4: Teleportation 53 5: Telepathy 70 6: Psychokinesis 88 7: Robots 103 8: Extraterrestrials and UFOs 126 9: Starships 154 10: Antimatter and Anti-universes 179 Port II: Class II Impossibilities 11 : Faster Than Light 197 12: Time Travel 216 13: Parallel Universes 229 Port III: Class III Impossibilities 14: Perpetual Motion Machines 257 15: Precognition 272 Epilogue: The Future of the Impossible 284 Notes 305 Bibliography 317 Index 319 If at first an idea does not sound absurd, then there is no hope for it -ALBERT EINSTEIN One day, would it be possible to walk through walls? To build starships that can travel faster than the speed of light? To read other people's minds? To become invisible? To move objects with the power of our minds? To transport our bodies instantly through outer space? Since I was a child, I've always been fascinated by these questions. Like many physicists, when I was growing up, I was mesmerized by the possibility of time travel, ray guns, force fields, parallel universes, and the like. Magic, fantasy, science fiction were all a gigantic play­ ground for my imagination. They began my lifelong love affair with the impossible. I remember watching the old Flash Gordon reruns on TV. Every Saturday, I was glued to the TV set, marveling at the adventures of Flash, Dr. Zarkov, and Dale Arden and their dazzling array of futuris­ tic technology: the rocket ships, invisibility shields, ray guns, and cities in the sky. I never missed a week. The program opened up an entirely new world for me. I was thrilled by the thought of one day rocketing to an alien planet and exploring its strange terrain. Being pulled into the orbit of these fantastic inventions I knew that my own destiny was PREFACE somehow wrapped up with the marvels of the science that the show promised. As it turns out, I was not alone. Many highly accomplished scien­ tists originally became interested in science through exposure to sci­ ence fiction. The great astronomer Edwin Hubble was fascinated by the works of Jules Verne. As a result of reading Verne's work, Hubble abandoned a promising career in law, and, disobeying his father's wishes, set off on a career in science. He eventually became the great­ est astronomer of the twentieth century. Carl Sagan, noted astronomer and bestselling author, found his imagination set afire by reading Edgar Rice Burroughs's John Carter of Mars novels. Like John Carter, he dreamed of one day exploring the sands of Mars. I was just a child the day when Albert Einstein died, but I remem­ ber people talking about his life, and death, in hushed tones. The next day I saw in the newspapers a picture of his desk, with the unfinished manuscript of his greatest, unfinished work. I asked myself, What could be so important that the greatest scientist of our time could not finish it? The article claimed that Einstein had an impossible dream, a problem so difficult that it was not possible for a mortal to finish it. It took me years to find out what that manuscript was about: a grand, unifying "theory of everything." His dream-which consumed the last three decades of his life-helped me to focus my own imagination. I wanted, in some small way, to be part of the effort to complete Ein­ stein's work, to unify the laws of physics into a single theory. As I grew older I began to realize that although Flash Gordon was the hero and always got the girl, it was the scientist who actually made the TV series work. Without Dr. Zarkov, there would be no rocket ship, no trips to Mongo, no saving Earth. Heroics aside, without science there is no science fiction. I came to realize that these tales were simply impossible in terms of the science involved, just flights of the imagination. Growing up meant putting away such fantasy. In real life, I was told, one had to abandon the impossible and embrace the practical. However, I concluded that if I was to continue my fascination with the impossible, the key was through the realm of physics. Without a PBEFUCE XI solid background in advanced physics, I would be forever speculating about futuristic technologies without understanding whether or not they were possible. I realized I needed to immerse myself in advanced mathematics and learn theoretical physics. So that is what I did. In high school for my science fair project I assembled an atom smasher in my mom's garage. I went to the Westinghouse company and gathered 400 pounds of scrap transformer steel.