Until the End of Time
ALSO BY BRIAN GREENE
The Hidden Reality
The Fabric of the Cosmos
The Elegant Universe
THIS IS A BORZOI BOOK PUBLISHED BY ALFRED A. KNOPF
Copyright © 2020 by Brian Greene
All rights reserved. Published in the United States by Alfred A. Knopf, a division of Penguin Random House LLC, New York, and distributed in Canada by Penguin Random House Canada Limited, Toronto.
www.aaknopf.com
Knopf, Borzoi Books, and the colophon are registered trademarks of Penguin Random House LLC.
Library of Congress Cataloging-in-Publication Data
Names: Greene, B. (Brian), [date] author.
Title: Until the end of time : mind, matter, and our search for meaning in an evolving universe / Brian Greene.
Description: First edition. | New York : Alfred A. Knopf Books, 2020. | Includes bibliographical references and index.
Identifiers: LCCN 2019022442 (print) | LCCN 2019022443 (ebook) | ISBN 9781524731670 (hardcover) | ISBN 9781524731687 (ebook)
Subjects: LCSH: Cosmology. | Physics—Philosophy.
Classification: LCC QB981 .G7434 2020 (print) | LCC QB981 (ebook) | DDC 523.1—dc23
LC record available at https://lccn.loc.gov/2019022442
LC ebook record available at https://lccn.loc.gov/2019022443
Ebook ISBN 9781524731687
Cover photograph by shaunl/E+/Getty Images
Cover design by Chip Kidd
ep_prh_5.4_c0_r1
For Tracy
Contents
Cover
Also by Brian Greene
Title Page
Copyright
Dedication
Preface
1. The Lure of Eternity: Beginnings, Endings, and Beyond
2. The Language of Time: Past, Future, and Change
3. Origins and Entropy: From Creation to Structure
4. Information and Vitality: From Structure to Life
5. Particles and Consciousness: From Life to Mind
6. Language and Story: From Mind to Imagination
7. Brains and Belief: From Imagination to the Sacred
8. Instinct and Creativity: From the Sacred to the Sublime
9. Duration and Impermanence: From the Sublime to the Final Thought
10. The Twilight of Time: Quanta, Probability, and Eternity
11. The Nobility of Being: Mind, Matter, and Meaning
Acknowledgments
Notes
Bibliography
A Note About the Author
Preface
“I do mathematics because once you prove a theorem, it stands. Forever.”1 The statement, simple and direct, was startling. I was a sophomore in college and had mentioned to an older friend, who for years had taught me vast areas of mathematics, that I was writing a paper on human motivation for a psychology course I was taking. His response was transformative. Until then, I hadn’t thought about mathematics in terms even remotely similar. To me, math was a wondrous game of abstract precision played by a peculiar community who would delight at punch lines turning on square roots or dividing by zero. But with his remark, the cogs suddenly clicked. Yes, I thought. That is the romance of mathematics. Creativity constrained by logic and a set of axioms dictates how ideas can be manipulated and combined to reveal unshakable truths. Every right-angled triangle drawn from before Pythagoras and on to eternity satisfies the famous theorem that bears his name. There are no exceptions. Sure, you can change the assumptions and find yourself exploring new realms, such as triangles drawn on a curved surface like the skin of a basketball, which can upend Pythagoras’s conclusion. But fix your assumptions, double-check your work, and your result is ready to be chiseled in stone. No climbing to the mountaintop, no wandering the desert, no triumphing over the underworld. You can sit comfortably at a desk and use paper, pencil, and a penetrating mind to create something timeless.
The perspective opened my world. I had never really asked myself why I was so deeply attracted to mathematics and physics. Solving problems, learning how the universe is put together—that’s what had always captivated me. I now became convinced that I was drawn to these disciplines because they hovered above the impermanent nature of the everyday. However overblown my youthful sensibilities rendered my commitment, I was suddenly sure I wanted to be part of a journey toward insights so fundamental that they would never change. Let governments rise and fall, let World Series be won and lost, let legends of film, television, and stage come and go. I wanted to spend my life catching a glimpse of something transcendent.
In the meantime, I still had that psychology paper to write. The assignment was to develop a theory of why we humans do what we do, but each time I started writing, the project seemed decidedly nebulous. If you clothed reasonable-sounding ideas in the right language it seemed that you could pretty much make it up as you went along. I mentioned this over dinner at my dorm and one of the resident advisors suggested I take a look at Oswald Spengler’s Decline of the West. A German historian and philosopher, Spengler had an abiding interest in both mathematics and science, no doubt the very reason his book had been recommended.
The aspects responsible for the book’s fame and scorn—predictions of political implosion, a veiled espousal of fascism—are deeply troubling and have since been used to support insidious ideologies, but I was too narrowly focused for any of this to register. Instead, I was intrigued by Spengler’s vision of an all-encompassing set of principles that would reveal hidden patterns playing out across disparate cultures, on par with the patterns articulated by calculus and Euclidean geometry that had transformed understanding in physics and mathematics.2 Spengler was talking my language. It was inspiring for a text on history to revere math and physics as a template for progress. But then came an observation that caught me thoroughly by surprise: “Man is the only being that knows death; all others become old, but with a consciousness wholly limited to the moment which must seem to them eternal,” knowledge that instills the “essentially human fear in the presence of death.” Spengler concluded that “every religion, every scientific investigation, every philosophy proceeds from it.”3
I remember dwelling on the last line. Here was a perspective on human motivation that made sense to me. The enchantment of a mathematical proof might be that it stands forever. The appeal of a law of nature might be its timeless quality. But what drives us to seek the timeless, to search for qualities that may last forever? Perhaps it all comes from our singular awareness that we are anything but timeless, that our lives are anything but forever. Resonating with my newfound thinking on math, physics, and the allure of eternity, this felt on target. It was an approach to human motivation grounded in a plausible reaction to a pervasive recognition. It was an approach that didn’t make it up on the fly.
As I continued to think about this conclusion, it seemed to promise something grander still. Science, as Spengler noted, is one response to the knowledge of our inescapable end. And so is religion. And so is philosophy. But, really, why stop there? According to Otto Rank, an early disciple of Freud who was fascinated by the human creative process, we surely shouldn’t. The artist, in Rank’s assessment, is someone whose “creative impulse…attempts to turn ephemeral life into personal immortality.”4 Jean-Paul Sartre went farther, noting that life itself is drained of meaning “when you have lost the illusion of being eternal.”5 The suggestion, then, threading its way through these and other thinkers who followed, is that much of human cultur
e—from artistic exploration to scientific discovery—is driven by life reflecting on the finite nature of life.
Deep waters. Who knew that a preoccupation with all things mathematics and physics would tap into visions of a unified theory of human civilization driven by the rich duality of life and death?
Well, OK. I’ll take a breath as I remind my long-ago sophomore self not to get too carried away. Nonetheless, the excitement I felt proved more than a passing wide-eyed intellectual wonderment. In the nearly four decades since, these themes, often simmering on a mental back burner, have stayed with me. While my day-to-day work has pursued unified theories and cosmic origins, in ruminating on the larger significance of scientific advances I have found myself returning repeatedly to questions of time and the limited allotment we are each given. Now, by training and temperament, I’m skeptical of one-size-fits-all explanations—physics is littered with unsuccessful unified theories of nature’s forces—only more so if we venture into the complex realm of human behavior. Indeed, I have come to see my awareness of my own inevitable end as having considerable influence but not providing a blanket explanation for everything I do. It’s an assessment, I imagine, that to varying degrees is common. Still, there is one domain in which mortality’s tentacles are particularly evident.
Across cultures and through the ages, we have placed significant value on permanence. The ways we have done so are abundant: some seek absolute truth, others strive for enduring legacies, some build formidable monuments, others pursue immutable laws, and others still turn with fervor toward one or another version of the everlasting. Eternity, as these preoccupations demonstrate, has a powerful pull on the mind aware that its material duration is limited.
In our era, scientists equipped with the tools of experiment, observation, and mathematical analysis have blazed a new trail toward the future, one that for the first time has revealed prominent features of the eventual if still far-off landscape-to-be. Although obscured by mist here and fog there, the panorama is becoming sufficiently clear that we cogitating creatures can glean more fully than ever before how we fit into the grand expanse of time.
It is in this spirit, in the pages that follow, that we will walk the timeline of the universe, exploring the physical principles that yield orderly structures from stars and galaxies to life and consciousness, within a universe destined for decay. We will consider arguments establishing that much as human beings have limited life spans, so too do the very phenomena of life and mind in the universe. Indeed, at some point it is likely that organized matter of any kind will not be possible. We will examine how self-reflective beings contend with the tension entailed in these realizations. We emerge from laws that, as far as we can tell, are timeless, and yet we exist for the briefest moment of time. We are guided by laws that operate without concern for destination, and yet we constantly ask ourselves where we are headed. We are shaped by laws that seem not to require an underlying rationale, and yet we persistently seek meaning and purpose.
In short, we will survey the universe from the beginning of time to something akin to the end, and through the journey explore the breathtaking ways in which restless and inventive minds have illuminated and responded to the fundamental transience of everything.
We will be guided in the exploration by insights from a variety of scientific disciplines. Through analogies and metaphors, I explain all necessary ideas in nontechnical terms, presuming only the most modest background. For particularly challenging concepts, I provide brief summaries that allow you to move on without losing the trail. In the endnotes I explain finer points, spell out particular mathematical details, and provide references and suggestions for further reading.
Because the subject is vast and our pages limited, I have chosen to walk a tight path, pausing at various junctures I consider essential for recognizing our place within the larger cosmological story. It is a journey powered by science, given significance by humanity, and the source of a vigorous and enriching adventure.
1
THE LURE OF ETERNITY
Beginnings, Endings, and Beyond
In the fullness of time all that lives will die. For more than three billion years, as species simple and complex found their place in earth’s hierarchy, the scythe of death has cast a persistent shadow over the flowering of life. Diversity spread as life crawled from the oceans, strode on land, and took flight in the skies. But wait long enough and the ledger of birth and death, with entries more numerous than stars in the galaxy, will balance with dispassionate precision. The unfolding of any given life is beyond prediction. The final fate of any given life is a foregone conclusion.
And yet this looming end, as inevitable as the setting sun, is something only we humans seem to notice. Long before our arrival, the thunderous clap of storm clouds, the raging might of volcanoes, the tremulous shudders of a quaking earth surely sent scurrying everything with the power to scurry. But such flights are an instinctual reaction to a present danger. Most life lives in the moment, with fear born of immediate perception. It is only you and I and the rest of our lot that can reflect on the distant past, imagine the future, and grasp the darkness that awaits.
It’s terrifying. Not the kind of terror that makes us flinch or run for cover. Rather, it’s a foreboding that quietly lives within us, one we learn to tamp down, to accept, to make light of. But underneath the obscuring layers is the ever-present, unsettling fact of what lies in store, knowledge that William James described as the “worm at the core of all our usual springs of delight.”1 To work and play, to yearn and strive, to long and love, all of it stitching us ever more tightly into the tapestry of the lives we share, and for it all then to be gone—well, to paraphrase Steven Wright, it’s enough to scare you half to death. Twice.
Of course, most of us, in the service of sanity, don’t fixate on the end. We go about the world focused on worldly concerns. We accept the inevitable and direct our energies to other things. Yet the recognition that our time is finite is always with us, helping to shape the choices we make, the challenges we accept, the paths we follow. As cultural anthropologist Ernest Becker maintained, we are under a constant existential tension, pulled toward the sky by a consciousness that can soar to the heights of Shakespeare, Beethoven, and Einstein but tethered to earth by a physical form that will decay to dust. “Man is literally split in two: he has an awareness of his own splendid uniqueness in that he sticks out of nature with a towering majesty, and yet he goes back into the ground a few feet in order blindly and dumbly to rot and disappear forever.”2 According to Becker, we are impelled by such awareness to deny death the capacity to erase us. Some soothe the existential yearning through commitment to family, a team, a movement, a religion, a nation—constructs that will outlast the individual’s allotted time on earth. Others leave behind creative expressions, artifacts that extend the duration of their presence symbolically. “We fly to Beauty,” said Emerson, “as an asylum from the terrors of finite nature.”3 Others still seek to vanquish death by winning or conquering, as if stature, power, and wealth command an immunity unavailable to the common mortal.
Across the millennia, one consequence has been a widespread fascination with all things, real or imagined, that touch on the timeless. From prophesies of an afterlife, to teachings of reincarnation, to entreaties of the windswept mandala, we have developed strategies to contend with knowledge of our impermanence and, often with hope, sometimes with resignation, to gesture toward eternity. What’s new in our age is the remarkable power of science to tell a lucid story not only of the past, back to the big bang, but also of the future. Eternity itself may forever lie beyond the reach of our equations, but our analyses have already revealed that the universe we have come to know is transitory. From planets to stars, solar systems to galaxies, black holes to swirling nebulae, nothing is everlasting. Indeed, as far as we can tell, not only is each individual life finite, but so too is life itself. Planet earth, which C
arl Sagan described as a “mote of dust suspended on a sunbeam,” is an evanescent bloom in an exquisite cosmos that will ultimately be barren. Motes of dust, nearby or distant, dance on sunbeams for merely a moment.
Still, here on earth we have punctuated our moment with astonishing feats of insight, creativity, and ingenuity as each generation has built on the achievements of those who have gone before, seeking clarity on how it all came to be, pursuing coherence in where it is all going, and longing for an answer to why it all matters.
Such is the story of this book.
Stories of Nearly Everything
We are a species that delights in story. We look out on reality, we grasp patterns, and we join them into narratives that can captivate, inform, startle, amuse, and thrill. The plural—narratives—is utterly essential. In the library of human reflection, there is no single, unified volume that conveys ultimate understanding. Instead, we have written many nested stories that probe different domains of human inquiry and experience: stories, that is, that parse the patterns of reality using different grammars and vocabularies. Protons, neutrons, electrons, and nature’s other particles are essential for telling the reductionist story, analyzing the stuff of reality, from planets to Picasso, in terms of their microphysical constituents. Metabolism, replication, mutation, and adaptation are essential for telling the story of life’s emergence and development, analyzing the biochemical workings of remarkable molecules and the cells they govern. Neurons, information, thought, and awareness are essential for the story of mind—and with that the narratives proliferate: myth to religion, literature to philosophy, art to music, telling of humankind’s struggle for survival, will to understand, urge for expression, and search for meaning.