Praise for The Greatest Story Ever Told—So Far

Praise for The Greatest Story Ever Told—So Far "In every debate I've done with theologians and religious believers, their knock-out final argument always comes in the form of two questions: Why is there something rather than nothing? and Why are we here? The presumption is that if science provides no answers then there must be a God. But God or no, we still want answers. In A Universe from Nothing Lawrence Krauss, one of the biggest thinkers of our time, addressed the first question with verve, and in The Greatest Story Ever Told he tackles the second with elegance. Both volumes should be placed in hotel rooms across America, in the drawer next to the Gideon Bible —Michael Shermer, publisher of Skeptic magazine, columnist for Scientific American, and author of The Moral Arc "Discovering the bedrock nature of physical reality ranks as one of humanity's greatest collective achievements. This book gives a fine account of the main ideas and how they emerged. Krauss is himself close to the field and can offer insights into the personalities who have led the key advances. A practiced and skilled writer, he succeeds in making the physics 'as simple as possible but no simpler: I don't know a better book on this subject? —Martin Rees, author of Just Six Numbers "It is an exhilarating experience to be led through this fascinating story, from Galileo to the Standard Model and the Higgs boson and beyond, with lucid detail and insight, illuminating vividly not only the achieve- ments themselves but also the joy of creative thought and discovery, 2P_Glealer-StoryEverTold_Atirdd I 12/16116 3:06 PIA EFTA00285909 enriched with vignettes of the remarkable individuals who paved the way. It amply demonstrates that the discovery that 'nature really follows the simple and elegant rules intuited by the twentieth- and twenty-first- century versions of Plato's philosopher? is one of the most astonishing achievements of the human intellect." —Noam Chomsky, Institute Professor & Professor of Linguistics (emeritus), MIT "Charming ... Krauss has written an account with sweep and verve that shows the full development of our ideas about the makeup of the world around us.... A great romp." —Walter Gilbert, Nobel laureate in chemistry 1 loved the fight scenes and the sex scenes were excellent." —Eric Idle 2P_GlealerASIonEverTold_Atirdd 2 1211&I6 3:06 PIA EFTA00285910 ALSO BY LAWRENCE M. KRAUSS A Universe from Nothing The Fifth Essence Fear of Physics The Physics of Star Trek Beyond Star Trek Hiding in the Mirror Quintessence Atom Quantum Man 2P_Glealer-StoryEverTold_Atirdd 3 12/1&I6 3:06 PIA EFTA00285911 1 1._ 11.1,, EFTA00285912 THE GREATEST STORY EVER TOLD-SO FAR WHY ARE WE HERE? Lawrence M. Krauss ATRIA BOOKS NEWS YORH . . •0130,,, . ,,.NEV . \EW' DELHI EFTA00285913 ATRIA BOOKS An Imprint of Simon & Schuster, Inc. 1230 Avenue of the Americas New York, NY 10020 Copyright 0 2017 by Lawrence Krauss All rights reserved, including the right to reproduce this book or portions thereof in any form whatsoever. For information, address Atria Books Subsidiary Rights Department. 1230 Avenue of the Americas, New York, NY 10020. First Atria Books hardcover edition March 2017 ATRIA BOOKS and colophon are trademarks of Simon & Schuster, Inc. For information about special discounts for bulk purchases, please contact Simon & Schuster Special Sales at 1-866-506-1949 or The Simon & Schuster Speakers Bureau can bring authors to your live event. For more information or to book an event, contact the Simon & Schuster Speakers Bureau at 1-866-248-3049 or visit our website at Interior design by Dana Sloan Manufactured in the United States of America 109 8 7 6 543 2 1 Library of Congress Cataloging -in-Publication Data ISBN 978-1-4767-7761-0 ISBN 978-1-4767-7763-4 (ebook) 2P_Glealer-StoryEverrold_Atirdd 6 12/16116 3:06 PIA EFTA00285914 For Nancy 2P_Glealer-StoryEverTold_AC.irdd 7 128616 06 PM EFTA00285915 2P_Gtealer-StoryEverTold_Atirdd S 12/16116 3:06 PM EFTA00285916 These are the tears of things, and the stuff of our mortality cuts us to the heart. —VIRGIL 2P_Glealer-SoryEverTold_Atirdd 9 12/1&16 3:06 Pt, EFTA00285917 2P_GreatestSteryEverrold_AC.indd 10 12/16/16 3:06 PM EFTA00285918 CONTENTS Prologue 1 Part One: Genesis Chapter 1: From the Armoire to the Cave 9 Chapter 2: Seeing in the Dark 19 Chapter 3: Through a Glass, Lightly 33 Chapter 4: There, and Back Again 45 Chapter S: A Stitch in Time 55 Chapter 6: The Shadows of Reality 71 Chapter?: A Universe Stranger than Fiction 83 Chapter 8: A Wrinkle in Time 97 Chapter 9: Decay and Rubble 113 Chapter 10: From Here to Infinity: Shedding Light on the Sun 125 Part Two: Exodus Chapter 11: Desperate Times and Desperate Measures Chapter 12: March of the Titans Chapter 13: Endless Forms Most Beautiful: Symmetry Strikes Back xl 139 151 167 2P_Glealer-StoryEverrold_Atirdd 11 12/18118 3:08 MA I EFTA00285919 xi' CONTENTS Chapter 14: Cold, Stark Reality: Breaking Bad or Beautiful? 181 Chapter 15: Living inside a Superconductor 191 Chapter 16: The Bearable Heaviness of Being: Symmetry Broken, Physics Fixed 201 Part Three: Revelation Chapter 17 The Wrong Place at the Right Time 211 Chapter 18: The Fog Lifts 219 Chapter 19: Free at Last 231 Chapter 2O: Spanking the Vacuum 249 Chapter 21: Gothic Cathedrals of the Twenty-First Century 259 Chapter 22: More Questions than Answers 275 Chapter 23: From a Beer Party to the End of Time 289 Epilogue: Cosmic Humility 301 Acknowledgments 307 Index 309 2P_GrealestSloryEverTald_AC.indd 12 12/16116 3:06 PIA EFTA00285920 rgd 93:C 90141 CI Prur0Y -PRIAm3koiSaM 0,0 4C LI VA OS C1101 2:13/V3 _LSA_LVAL10 '3H1 EFTA00285921 2P_Gtealer-StoryEverTold_Atincld 14 12/16116 3:06 PM EFTA00285922 PROLOGUE The hardest thing of all to see Is what Is really there. -J. A. BAKER, THE PEREGRINE Lthe beginning there was light. But more than this, there was gravity. After that, all hell broke loose.... This is how the story of the greatest intellectual adventure in history might properly be introduced. It is a story of science's quest to uncover the hidden realities underlying the world of our experience, which required marshaling the very pinnacle of human creativity and intellectual bravery on an unparalleled global scale. This process would not have been possible without a willingness to dispense with all kinds of beliefs and preconcep- tions and dogma, scientific and otherwise. The story is filled with drama and surprise. It spans the full arc of human history, and most remarkably, the current version isn't even the final one—just another working draft. It's a story that deserves to be shared far more broadly. Already in the first world, parts of this story are helping to slowly replace the myths and superstitions that more ignorant societies found solace in centuries or millennia ago. Nevertheless, thanks to the directors George Stevens and David Lean, the Judeo-Christian Bible is still sometimes referred 2P_Glealer-StoryEverTold_Atirdd I 12/16116 3:06 PIA EFTA00285923 2 PROLOGUE to as "the greatest story ever told." This characterization is astounding because, even allowing for the frequent sex and violence, and a bit of poetry in the Psalms, the Bible as a piece of literature arguably does not compare well to the equally racy but less violent Greek and Roman epics such as the Aeneid or the Odyssey-even if the English translation of the Bible has served as a model for many subsequent books. Either way, as a guide for understanding the world, the Bible is pathetically inconsis- tent and outdated. And one might legitimately argue that as a guide for human behavior large swaths of it border on the obscene. In science, the very word sacred is profane. No ideas, religious or otherwise, get a free pass. For this reason the pinnacle of the human story did not conclude with a prophet's sacrifice two thousand years ago, any more than it did with the death of another prophet six hundred years later. The story of our origins and our future is a tale that keeps on telling. And the story is getting more interesting all the time, not due to revelation, but due to the steady march of scientific discovery. Contrary to many popular perceptions, this scientific story also en- compasses both poetry and a deep spirituality. But this spirituality has the additional virtue of being tied to the real world—and not created in large part to appease our hopes and dreams. The lessons of our exploration into the unknown, led not by our de- sires, but by the force of experiment, are humbling. Five hundred years of science have liberated humanity from the shackles of enforced igno- rance. By this standard, what cosmic arrogance lies at the heart of the assertion that the universe was created so that we could exist? What myopia lies at the heart of the assumption that the universe of our expe- rience is characteristic of the universe throughout all of time and space? This anthropocentrism has fallen by the wayside as a result of the story of science. What replaces it? Have we lost something in the pro- cess, or as I shall argue, have we gained something even greater? I once said at a public event that the business of science is to make people uncomfortable. I briefly regretted the remark because I worried 2P_Glealer-StoryEverTold_Atincld 2 12/16116 3:06 PIA EFTA00285924 PROLOGUE 3 that it would scare people away. But being uncomfortable is a virtue, not a hindrance. Everything about our evolutionary history has primed our minds to be comfortable with concepts that helped us survive, such as the natural teleological tendency children have to assume objects exist to serve a goal, and the broader tendency to anthropomorphize, to as- sign agency to lifeless objects, because clearly it is better to mistake an inert object for a threat than a threat for an inert object. Evolution didn't prepare our minds to appreciate long or short time- scales or short or huge distances that we cannot experience directly. So it is no wonder that some of the remarkable discoveries of the scientific method, such as evolution and quantum mechanics, are nonintuitive at best, and can draw most of us well outside our myopic comfort zone. This is also what makes the greatest story ever told so worth telling. The best stories challenge us. They cause us to see ourselves differently, to re- align our picture of ourselves and our place in the cosmos. This is not only true for the greatest literature, music, and art. It is true of science as well. In this sense it is unfortunate that replacing ancient beliefs with modern scientific enlightenment is often described as a "loss of faith." How much greater is the story our children will be able to tell than the story we have told? Surely that is the greatest contribution of science to civilization: to ensure that the greatest books are not those of the past, but of the future. Every epic story has a moral. In ours, we find that letting the cosmos guide our minds through empirical discovery can produce a great rich- ness of spirit that harnesses the best of what humanity has to offer. It can give us hope for the future by allowing us to enter it with our eyes open and with the necessary tools to actively participate in it. • • • My previous book, A Universe from Nothing, described how the revolu- tionary discoveries over the past hundred years have changed the way we understand our evolving universe on its largest scales. This change has led science to begin to directly address the question Why is there something 2P_Glealer-StoryEverrold_Atirdd 3 12/16116 3:06 PIA EFTA00285925 4 PROLOGUE rather than nothing?" —which was formerly religious territory—and re- work it into something less solipsistic and operationally more useful. Like A Universe from Nothing, this story also originated in a lecture I presented, in this case at the Smithsonian Institution in Washington, DC, which generated some excitement at the time, and as a result I was once again driven to elaborate upon the ideas I started to develop there. In con- trast to A Universe from Nothing, in this book I explore the other end of the spectrum of our knowledge and its equally powerful implications for under- standing age-old questions. The profound changes over the past hundred years in the way we understand nature at its smallest scales are allowing us to similarly co-opt the equally fundamental question Why are we here?" We will find that reality is not what we think it is. Under the surface are "weird: counterintuitive, invisible inner workings that can chal- lenge our preconceptions of what makes sense as much as a universe arising from nothing might. And like the conclusion I drew in my last book, the ultimate lesson from the story I will tell here is that there is no obvious plan or purpose to the world we find ourselves living in. Our existence was not preordained, but appears to be a curious accident. We teeter on a precarious ledge with the ultimate balance determined by phenomena that lie well beneath the surface of our experience —phenomena that don't rely in any way upon our existence. In this sense, Einstein was wrong: "God" does appear to play dice with the universe, or universes. So far we have been lucky. But like playing at the craps table, our luck may not last forever. • • • Humanity took a major step toward modernity when it dawned in our ancestors' consciousness that there is more to the universe than meets the eye. This realization was probably not accidental. We appear to be hardwired to need a narrative that transcends and makes sense of our own existence, a need that was probably intimately related to the rise of religious belief in early human societies. 2P_Glealer-StoryEverTold_Atincld 4 12/16116 3:06 PIA EFTA00285926 PROLOGUE 5 By contrast, the story of the rise of modern science and its divergence from superstition is the tale of how the hidden realities of nature were uncovered by reason and experiment through a process in which seem- ingly disparate, strange, and sometimes threatening phenomena were ultimately understood to be connected just beneath the visible surface. Ultimately these connections dispelled the goblins and fairies that had earlier spawned among our ancestors. The discovery of connections between otherwise seemingly dispa- rate phenomena is, more than any other single indicator, the hallmark of progress in science. The many classic examples include Newton's connection of the orbit of the Moon to a falling apple; Galileo's recogni- tion that vastly different observed behaviors for falling objects obscure that they are actually attracted to the earth's surface at the same rate; and Darwin's epic realization that the diversity of life on Earth could arise from a single progenitor by the simple process of natural selection. None of these connections was all that obvious, at first. However, after the relationship comes to light and becomes clear, it prompts an "Ahar experience of understanding and familiarity. One feels like saying, 1 should have thought of that!" Our modern picture of nature at its most fundamental scale—the Standard Model, as it has become called—contains an embarrassment of riches, connections that are far removed from the realm of everyday experience. So far removed that it is impossible without some ground- ing to make the leap in one step to visualize them. Not surprisingly, such a single leap never occurred historically, ei- ther. A series of remarkable and unexpected and seemingly unrelated connections emerged to form the coherent picture we now have. The mathematical architecture that has resulted is so ornate that it almost seems arbitrary. "Ahar is usually the furthest thing from the lips of the noninitiated when they hear about the Higgs boson or Grand Unifica- tion of the forces of nature. To move beyond the surface layers of reality, we need a story that 2P_Glealer-StoryEverTold_Atirdd S 12/16116 3:06 PM EFTA00285927 6 PROLOGUE connects the world we know with the deepest corners of the invisible world all around us. We cannot understand that hidden world with in- tuitions based solely on direct sensation. That is the story I want to tell here. I will take you on a journey to the heart of those mysteries that lie at the edge of our understanding of space, time, and the forces that operate within them. My goal is not to unnecessarily provoke or offend, but to prod you, just as we physicists ourselves have been prodded and dragged by new discoveries into a new reality that is at once both un- comfortable and uplifting. Our most recent discoveries about nature's fundamental scales have chillingly altered our perception of the inevitability of our presence in the universe. They provide evidence too that the future will no doubt be radically different from what we might otherwise have imagined, and they too further decrease our cosmic significance. We might prefer to deny this uncomfortable, inconvenient reality, this impersonal, apparently random universe, but if we view it in an- other context, all of this need not be depressing. A universe without purpose, which is the way it is as far as I can tell, is far more exciting than one designed just for us because it means that the possibilities of existence are so much more diverse and far ranging. How invigorating it is to find ourselves with an exotic menagerie to explore, with laws and phenomena that previously seemed beyond our wildest dreams, and to attempt to untangle the knotted confusion of experience and to search for some sense of order beneath. And how fascinating it is to discover that order, and to piece together a coherent picture of the universe on scales far beyond those that we may ever directly experience —a picture woven together by our ability to predict what will happen next, and the consequent ability to control the environment around us. How lucky to have our brief moment in the Sun. Every day that we discover some- thing new and surprising, the story gets even better. 2P_Glealer-StoryEverTold_Atirdd S 12/16116 3:06 PIA EFTA00285928 Part One GENESIS EFTA00285929 2P_Gtealer-StoryEverTold_Atirdd S 12/16116 3:06 PM EFTA00285930 Chapter 1 FROM THE ARMOIRE TO THE CAVE The simple inherit folly, but the prudent are crowned with knowledge. -PROVERBS 14:18 Lmy beginning there was light. Surely there was light at the beginning of time, but before we can get to the beginning of time, we will need to explore our own beginnings, which also means exploring the beginning of science. And that means returning to the ultimate motive for both science and religion: the longing for some- thing else. Something beyond the universe of our experience. For many people, that longing translates into something that gives meaning and purpose to the universe and extends to a longing for some hidden place that is better than the world in which we live, where sins are forgiven, pain is absent, and death does not exist. Others, however, long for a hidden place of a very different sort, the physical world beyond our senses, the world that helps us understand how things behave the way they do, rather than why. This hidden world underlies what we ex- perience, and the understanding of it gives us the power to change our lives, our environment, and our future. 9 2P_Gtealer-StoryEverTold_Atincld 9 12/16116 3:06 PIA EFTA00285931 10 THE GREATEST STORY EVER TOLD-SO FAR The contrast between these two worlds is reflected in two very dif- ferent works of literature. The first, The Lion, the Witch and the Wardrobe, by C. S. Lewis, is a twentieth-century children's fantasy with decidedly religious overtones. It captures a childhood experience most of us have had—looking under the bed or in the closet or in the attic for hidden treasure or evidence that there is more out there than what we normally experience. In the book, several schoolchildren discover a strange new world, Narnia, by climbing into a large wardrobe in the country house outside London where they have been sequestered for their protection during the Second World War. The chil- dren help save Narnia with the aid of a lion, who lets himself be humiliated and sacrificed, Christlike, at an altar in order to conquer evil in his world. While the religious allusion in story is clear, we can also in- terpret it in another way—as an allegory, not for the existence of God or the devil, but rather for the remarkable and potentially terrifying possi- bilities of the unknown, possibilities that lie just beyond the edge of our senses, just waiting for us to be brave enough to seek them out. Possibili- ties that, once revealed, may enrich our understanding of ourselves or, for some who feel a need, provide a sense of value and purpose. The portal to a hidden world inside the wardrobe is at once safe, with the familiar smell of oft-worn clothes, and mysterious. It implies the need to move beyond classical notions of space and time. For if nothing is revealed to an observer who is in front of or behind the wardrobe, and something is revealed only to someone inside, then the space experienced inside the wardrobe must be far larger than that seen from its outside. Such a concept is characteristic of a universe in which space and time can be dynamical, as in the General Theory of Relativity, where, for ex- ample, from outside the "event horizon" of a black hole—that radius inside of which there is no escape—a black hole might appear to comprise a small volume, but for an observer inside (who has not yet been crushed to smithereens by the gravitational forces present), the volume can look quite different. Indeed, it is possible, though beyond the domain where we 2P_GrealestSloryEverTold_AC.indd 10 12/10/16 3:06 PIA EFTA00285932 From the Armoire to the Cave 11 can perform reliable calculations, that the space inside a black hole might provide a portal to another universe disconnected from our own. But the central point I want to return to is that the possibility of universes beyond our perception seems to be tied, in the literary and philosophical imagination, at least, to the possibility that space itself is not what it seems. The harbinger of this notion, the "ur" story if you will, was written twenty-three centuries before Lewis penned his fantasy. I refer to Plato's Republic, and in particular to my favorite section, the Allegory of the Cave. But in spite of its early provenance, it illuminates more directly and more clearly both the potential necessity and the potential perils of searching for understanding beyond the reach of our immediate senses. In the allegory, Plato likens our experience of reality to that of a group of individuals who live their entire lives imprisoned inside a cave, forced to face a blank wall. Their only view of the real world is that wall, which is illuminated by a fire behind them, and on which they see shad- ows moving. The shadows come from objects located behind them that the light of the fire projects on the wall. I show the drawing below, which came from the high school text in which I first read this allegory, in a 1961 translation of Plato's dialogues. 2P_Glealer-StoryEverTold_Atirdd t1 12.'1&16 3:C8 PM EFTA00285933 12 THE GREATEST STORY EVER TOLD-SO FAR The drawing is amusing because it clearly reflects as much about the time it was drawn as it does the configuration of the cave described in the dialogue. Why, for example, are the prisoners here all women, and scantily clad ones at that? In Plato's day, any sexual allusion might easily have displayed young boys. Plato argues that the prisoners will view the shadows as reality and even give them names. This is not unreasonable, and it is, in one sense, as we shall soon see, a very modern view of what reality is, namely that which we can directly measure. My favorite definition of reality still is that given by the science fiction writer Philip K. Dick, who said, "Reality is that which, when you stop believing in it, doesn't go away." For the prisoners, the shadows are what they see. They are also likely to hear only the echoes of noises made behind them as the sounds bounce off the wall. Plato likened a philosopher to a prisoner who is freed from bondage and forced, almost against his will, to not only look at the fire, but to move past it, and out to the daylight beyond. First, the poor soul will be in distress, with the glare of the fire and the sunshine beyond the cave hurting his eyes. Objects will appear completely unfamiliar; they will not resemble their shadows. Plato argues that the new freeman may still imagine the shadows that he is used to as truer representations than the objects themselves that are casting the shadows. If the individual is reluctantly dragged out into the sunshine, ulti- mately all of these sensations of confusion and pain will be multiplied. But eventually, he will become accustomed to the real world, will see the stars and Moon and sky, and his soul and mind will be liberated of the illusions that had earlier governed his life. If the person returns to the cave, Plato argues, two things would hap- pen. First, because his eyes would no longer be accustomed to the dark- ness, he would be less able to distinguish the shadows and recognize them, and his compatriots would view him as handicapped at best, and 2P_GrealestStrayE-verTold_AC.indd 12 12/18/18 3:08 PIA EFTA00285934 From the Armoire to the Cave 13 dim at worst. Second, he would no longer view the petty and myopic priorities of his former society, or the honors given to those who might best recognize the shadows and predict their future, as worthy of his respect. As Plato poetically put it, quoting from Homer: "Better to be the poor servant of a poor master, and to endure any- thing, rather than think as they do and live after their manner." So much for those whose lives are lived entirely in illusion, which Plato suggests includes most of humanity. Then, the allegory states that the journey upward—into the light—is the ascent of the soul into the intellectual world. Clearly in Plato's mind only a retreat to the purely "intellectual world," a journey reserved for the few—aka philosophers —could replace illusion with reality. Happily, that journey is far more accessible today using the techniques of science, which combine reason and reflection with empirical inquiry. Nevertheless, the same challenge remains for scientists today: to see what is behind the shadows, to see that which, when you drop your preconceptions, doesn't disappear. While Plato doesn't explicitly mention it, not only would his fellow prisoners view the poor soul who had ventured out and returned as handicapped, but they would likely think he was crazy if he talked about the wonders that he had glimpsed: the Sun, the Moon, lakes, trees, and other people and their civilizations. This idea is strikingly modern. As the frontiers of science have moved further and further away from the world of the familiar and the world of common sense as inferred from our direct experience, our picture of the reality underlying our experience is getting increasingly difficult for us to comprehend or accept. Some find it more comforting to retreat to myth and superstition for guidance. But, we have every reason to expect that "common sense," which first evolved to help us cope with predators in the savannas of Africa, might lead us astray when we attempt to think about nature on vastly differ- 2P_Glealer-StoryEverTold_Aairdd 13 12/16116 3:06 PIA EFTA00285935 14 THE GREATEST STORY EVER TOLD-SO FAR ent scales. We didn't evolve to intuitively understand the world of the very small, the very big, or the very fast. We shouldn't expect the rules we have come to rely on for our daily lives to be universal. While that myopia was useful from an evolutionary perspective, as thinking beings we can move beyond it. In this regard, I cannot resist quoting one last admonition in Plato's allegory: "In the world of knowledge the idea of good appears last of all and is seen only with an effort; and, when seen, is also inferred to be the au- thor of all things good and right, parent of light, and ... the immediate source of reason and truth." Plato further argues that this is what those who would act rationally should strive for, in both public and private life—seeking the "good" by focusing on reason and truth. He suggests that we can only do so by exploring the realities that underlie the world of our direct experience, rather than by exploring the illusions of a reality that we might want to exist. Only through rational examination of what is real, and not by faith alone, is rational action—or good—possible. Today, Plato's vision of "pure thought" has been replaced by the sci- entific method, which, based on both reason and experiment, allows us to discover the underlying realities of the world. Rational action in public and private life now requires a basis in both reason and empiri- cal investigation, and it often requires a departure from the solipsistic world of our direct experience. This principle is the source of most of my own public activism in opposition to government policies based on ideology rather than evidence, and it is also probably why I respond so negatively to the concept of the "sacred"—implying as it does some idea or admonition that is off-limits to public questioning, exploration, dis- cussion, and sometimes ridicule. It is hard to state this view more strongly than I did in a New Yorker piece: 'Whenever scientific claims are presented as unquestionable, they undermine science. Similarly, when religious actions or claims 2P_Glealer-StoryEverTold_Atirdd 14 12/16116 3:06 PIA EFTA00285936 From the Armoire to the Cave 15 about sanctity can be made with impunity in our society, we undermine the basis of modern secular democracy. We owe it to ourselves and to our children not to give a free pass to governments —totalitarian, theo- cratic, or democratic —that endorse, encourage, enforce, or otherwise legitimize the suppression of open questioning in order to protect ideas that are considered 'sacred.' Five hundred years of science have liberated humanity from the shackles of enforced ignorance! Philosophical reflections aside, the prime reason I am introducing Plato's cave here is that it can provide a concrete example of the nature of the scientific discoveries at the heart of the story I want to tell. Imagine a shadow that our prisoners might see on the wall, displayed by an evil puppeteer located on a ledge in front of the fire: This shadow displays both length and directionality, two concepts that we, who are not confined to the cave, take for granted. However, as the prisoners watch, this shadow changes: Later it looks like this: And again later like this: And later still, like this: 2P_Glealer-StoryEverTold_Atirdd 15 12/16116 3:06 PIA EFTA00285937 16 THE GREATEST STORY EVER TOLD-SO FAR What would the prisoners infer from all of this? Presumably, that concepts such as length or direction have no absolute meaning. The ob- jects in their world can change both length and directionality arbitrarily. In the reality of their direct experience, neither length nor directionality appears to have significance. What will the natural philosopher, who has escaped to the surface to explore the richer world beyond the shadows, discover? He will see that the shadow is first of all just a shadow: a two-dimensional image on the wall cast from a real, three-dimensional object located behind the pris- oners. He will see that the object has a fixed length that never changes, and that it's accompanied by an arrow that is always on the same side of the object. From a vantage point slightly above the object, he sees that the series of images results from the projection of a rotating weather vane onto the wall: When he returns to join his former colleagues, the philosopher - scientist can explain that an absolute quantity called length doesn't change over time, and that directionality can be assigned unambiguously to cer- tain objects as well. He will tell his friends that the real world is three- dimensional, not two-dimensional, and that once they understand, all of their confusion about the seemingly arbitrary changes will disappear. Would they believe him? It would be a tough sell because they won't have an intuitive idea of what a rotation is (after all, with an intuition based purely on two-dimensional experience, it would likely be difficult to "picture" mentally any rotations in a third dimension). Blank stares? Probably. The loony bin? Maybe. However, he might win over the com- munity by stressing attractive characteristics associated with his claim: behavior that on the surface appears to be complex and arbitrary can be 2P_Glealer-StoryEverTold_Atindd 18 12/16116 3:06 PIA EFTA00285938 From the Armoire to the Cave 17 shown to result from a much simpler underlying picture of nature, and seemingly disparate phenomena are actually connected and can be part of a unified whole. Better still, he could make predictions that his friends could test. First, he could argue that, if the apparent change in length of the shadows measured by the group is really due to a rotation in a third dimension, whenever the length of the object briefly vanishes, it will immediately reemerge with the arrow pointing in the opposite direction. Second, he could argue that as the length oscillates, the maximum length of the shadow when the arrow is pointing in one direction will always be ex- actly the same as the maximum length of the shadow when it is pointing in the other direction. Plato's cave thus becomes an allegory for far more than he may have intended. Plato's freed man discovers the hallmarks of the remarkable true story of our own struggle to understand nature on its most fun- damental scales of space, time, and matter. We too have had to escape the shackles of our prior experience to uncover profound and beauti- ful simplifications and predictions that can be as terrifying as they are wonderful. But just as the light beyond Plato's cave is painful to the eyes at first, with time it becomes mesmerizing. And once witnessed, there is no going back. 2P_Glealer-Storgverrold_Atirdd 17 12/16116 3:06 PIA EFTA00285939 2P_GreatestSlowEverrold_AC.indd 18 1211&18 3:06 PM EFTA00285940 Chapter 2 SEEING IN THE DARK Let there be light: and there was light -GENESIS 1:3 Lthe beginning there was light. It is no coincidence that the ancients imagined in Genesis that light was created on the first day. Without light, there would be little aware- ness of the vast universe surrounding us. When we nod and say, 1 see," to a friend who is trying to explain something, we convey far more than just an observation, but rather a fundamental understanding. Plato's allegory was appropriately centered on light—light from a fire to cast the shadows on the cave wall and light from the outside to temporarily blind the freed prisoner and then illuminate the real world for him. Like the prisoners in the cave, we too are prisoners of light— almost everything we learn about the world we learn from what we see. While the most significant words in the Western religious canon may be Let there be light, in the modern world this phrase now has a completely different significance from what it once did. Human beings may be prisoners of light, but so is the universe. What once appeared as a whim of a Judeo-Christian God, or other gods before that one, we now understand to be required by the very laws that allow both heaven, and 19 2P_Glealer-StoryEverTold_Atirdd 19 1211&I6 3:06 PIA EFTA00285941 20 THE GREATEST STORY EVER TOLD-SO FAR more important, Earth, to exist. You cannot have one without the other. Earth, or matter, follows light. This change in perception underlies almost every development in the edifice we call modern science. I am writing these words as I stare out from a ship at one of the Galapagos Islands, which Charles Darwin made famous, and which made him famous in return, as he changed our perception of life and its diversity with a single brilliant realiza- tion: that all living species developed through the natural selection of small inherited variations that are passed along to future generations by survivors. As surely as the understanding of evolution changed every- thing about our understanding of biology, our changing understanding of light changed everything about our physical understanding of our place in the universe. As a useful fringe benefit, this change resulted in virtually all of the technology on which the modern world is based. The extent to which our observations of the world imprison our minds, and frame our description of the fabric of the universe, remained unappreciated for more than twenty centuries following Plato. Once se- rious minds began to investigate in detail the hidden nature of the uni- verse, it took over four centuries for them to fully resolve the question What is light? Perhaps the most serious modern mind, although certainly not the first, to ask this question was also one of the most famous—and oddest—scientists in history: Isaac Newton. It is not inappropriate to classify Newton as a modern mind—after all, his seventeenth -century Principia: Mathematical Principles of Natural Philosophy uncovered the classical laws of motion and laid the basis for his theory of gravity, both of which form the foundation of much of modern physics. Never- theless, as John Maynard Keynes pointed out: Newton was not the first of the age of reason, he was the last of the magicians, the last of the Babylonians and Sumerians, the last great mind that looked out on the visible and intellectual world 2P_Glealer-StoryEverrold_Atincld 20 12/16116 3:06 PIA EFTA00285942 Seeing in the Dark 21 with the same eyes as those who began to build our intellectual inheritance rather less than to,000 years ago. The truth of this statement reflects the revolutionary importance of Newton's work. After the Principia, no rational person could view the world the same way the ancients had viewed it. But it also reflects the character of Newton himself. He devoted far more time, and far more ink, to writing about the occult, alchemy, and searching for hidden meanings and codes in the Bible—focusing in particular on the Book of Revelation and mysteries associated with the ancient Temple of Solo- mon—than he did to writing about physics. Newton was also one in a long line of people, which extends before and after him, who felt that he had been specifically chosen by God to help reveal the true meaning of the Scriptures. To what extent his stud- ies of the universe derived from his fascination with the Bible is not clear, but it does seem reasonable to conclude that his primary interest was in theology, and that natural philosophy came in well below that, and probably below alchemy as well. Many individuals point to Newton's fascination with God as evi- dence of the compatibility between science and religion, and to assert that modern science owes its existence to Christianity. This confuses history with causality. It is undeniable that many of the early giants of modern Western natural philosophy, from Newton onward, were deeply religious, although Darwin lost much, if not all, of his reli- gious belief later in life. But remember that during much of this pe- riod there were primarily two sources of education and wealth: the Church and the Crown. The Church was the National Science Foun- dation of the fifteenth, sixteenth, and seventeenth centuries. All in- stitutions of higher learning were tied to various denominations, and it was unthinkable for any educated person to not be affiliated with the Church. And as Giordano Bruno and later Galileo discovered, it was unpleasant at best to counter its doctrine. It would have been 29_Glealer-StoryEverrold_Aairdd 21 12/16116 3:06 PIA EFTA00285943 22 THE GREATEST STORY EVER TOLD-SO FAR remarkable for any of these leading early scientific thinkers to have been anything but religious. The religiosity of the early scientific pioneers is also cited today by sophists who claim that science and religious doctrine are compatible, but who confuse science and scientists. In spite of frequent appearances to the contrary, scientists are people. And like all people they are capa- ble of holding many potentially mutually contradictory notions in their head at the same time. No correlation between divergent views held by any individual is representative of anything but human foibles. To claim that some scientists are or were religious is like saying some scientists are Republicans or some are flat-earthers or some are creationists. It doesn't imply causality or consistency. My friend Rich- ard Dawkins has told me of a professor of astrophysics who, during the day, writes papers that are published in astronomical journals assuming that the universe is more than 13 billion years old, but then goes home and privately espouses the literal biblical claim that the universe is six thousand years old. What determines intellectual consistency or lack thereof in the sci- ences is a combination of rational arguments with subsequent evidence and continued testing. It is perfectly reasonable to claim that religion, in the Western world, may be the mother of science. But as any parent knows, children rarely grow up to be models of their parents. Newton may, following tradition, have been motivated to look at light because it was a gift from God. But we remember his work not because of his motivation, but because of what he discovered. Newton was convinced that light was made of particles, which he re- ferred to as corpuscles, while Descartes, and later Newton's nemesis Robert Hooke, and still later the Dutch scientist Christiaan Huygens, all claimed that light was a wave. One of the key observations that appeared to support the wave theory was that white light, such as light from the Sun, could split into all the colors of the rainbow when passed through a prism. As was often the case during his life, Newton believed that he was 2P_Glealer-StoryEverTaid_Atirdd 22 12/16116 3:06 PIA EFTA00285944 Seeing in the Dark 23 correct and several of his most famous contemporaries (and competi- tors) were wrong. To demonstrate this, he devised a clever experiment using prisms that he first performed while at home in Woolsthorpe, to escape the bubonic plague ravaging Cambridge. As he reported at the Royal Society in 1672, on the forty-fourth try, he observed precisely what he hoped he would see. Advocates of the wave theory had argued that light waves were made of white light and that the light split into colors when it passed through a prism because of "corruption" of the rays as they traversed the glass. In this case, the more glass, the more splitting. Newton reasoned that this was not the case, but that light is made of colored particles that combine together to appear white. (With a nod to his occult fascination, Newton classified the colored particles of the spectrum-a term he coined—into seven different types: red, orange, yellow, green, blue, indigo, and violet. From the time of the Greeks, the number seven had been considered to possess mystical qualities.) To demonstrate that the wave/corruption picture was incorrect, Newton passed a beam of white light through two prisms held in opposite orien- tations. The first prism split the light into its spectrum, and the second recomposed it back into a single white light beam. This result would have been impossible if the glass had corrupted the light. A second prism would have simply made the situation worse and would not have caused the light to revert back to its original state. This result does not in fact disprove the wave theory of light (it actu- ally supports it, because light slows down as it bends upon entering the prism, just as waves would do). But since the advocates of that theory had argued (incorrectly) that the spectral splitting was due to corrup- tion, Newton's demonstration that this was not the case struck a signifi- cant blow in favor of his particle model. Newton went on to discover many other facets of light that we use today in our understanding of the wave nature of light. He showed that every color of light has a unique bend angle when passing through a 2P_Glealer-StoryEverrold_Aairdd 23 12/16116 3:06 PIA EFTA00285945 24 THE GREATEST STORY EVER TOLD-SO FAR glass prism. He also showed that all objects appear to be the same color as the color of the light beam illuminating them. And he showed that colored light will not change its color no matter how many times it is reflected by or passes through a prism. All of these results, including his original result, can be explained simply if white light is indeed composed of a collection of different col- ors—that much he got right. But they can't be explained if light is made of different-colored particles. Rather, white light is composed of waves of many different wavelengths. Newton's opponents did not give up easily, even in the face of New- ton's rising popularity and the death of his chief opponent, Hooke. They did not give up even after Newton's election as president of the Royal Society in 1703, the year he then actually published his research on light in his epic Opticks. Indeed, the debate on the nature of light continued to rage on for over a century. Part of the problem with a wave picture of light was the question 'hat is it that light is a wave of exactly?" And if it is a wave, then since all known waves require some medium, what medium does it travel in? These ques- tions were sufficiently perplexing that practitioners of the wave theory had to resurrect a new invisible substance permeating all space, the ether. The resolution of this conundrum came, as such resolutions often do, from a totally unexpected corner of the physical world, one full of sparks, and spinning wheels. When I was a young professor at Yale—in the ancient but huge office I was lucky enough to commandeer when an equally ancient colleague retired—there was left hanging for me a copy of a photograph of Mi- chael Faraday taken in 186i. I have treasured it ever since. I don't believe in hero worship, but if I did, Faraday would be up there with the best. Perhaps more than any other scientist of the nine- teenth century, he is responsible for the technology that powers our cur- rent civilization. Yet he had little formal education and at age fourteen became a bookbinder's apprentice. Later in his career, after achieving 2P_Glealer-StoryEverTold_Atirdd 24 12/18118 3:08 PIA EFTA00285946 Seeing in the Dark 25 world recognition for his scientific contributions, he insisted on keep- ing to his humble roots, turning down a knighthood and twice turning down the presidency of the Royal Society. Later on he refused to advise the British government on the production of chemical weapons for use in the Crimean War, citing ethical reasons. And for more than thirty- three years he gave a series of Christmas lectures at the Royal Institu- tion to excite young people about science. What's not to like? Much as one might admire the man, it is the scientist who matters here for our story. Faraday's first scientific lesson is one I tell my students: always suck up to your professors. At the age of twenty, after completing seven years of apprenticeship as a bookbinder, Faraday attended the lec- tures of the famous chemist Humphry Davy, then the head of the Royal Institution. Afterward Faraday presented Davy with a three-hundred - page, beautifully bound book containing the notes Faraday had taken during the lectures. Within a year, Faraday was appointed Davy's sec- retary and shortly thereafter got an appointment as chemical assistant in the Royal Institution. Later on, Faraday learned the same lesson but with the opposite result. Following his excitement over some early, quite significant experiments that he performed, Faraday accidentally forgot to acknowledge work with Davy in his published results. This acciden- tal snub probably resulted in his being reassigned to other activities by Davy and delaying his world-changing research by several years. When reassigned, Faraday had been working on the "hot" area of sci- entific research, the newly discovered connections between electricity and magnetism, driven by results of the Danish physicist Hans Christian Oersted. These two forces seem quite different, yet have odd similarities. Electric charges can attract or repel. So can magnets. Yet magnets always seem to have two poles, north and south, which cannot be isolated, while electric charges can individually be positive or negative. For some time, scientists and natural philosophers had wondered if the two forces might have some hidden connection, and the first empirical clue came to Oersted by accident In 182o, while delivering a lecture, Oersted 2P_GrealesiSleryEverTold_AC.indd 25 12/16116 3:06 PIA EFTA00285947 26 THE GREATEST STORY EVER TOLD-SO FAR saw that a compass needle was deflected when an electric current from a battery was switched on. A few months later he followed up on this ob- servation and discovered that a current of moving electric charges, which we now commonly call an electric current, produced a magnetic