The Elegant Universe - Brian Greene [0]
The Elegant Universe
Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory
Brian Greene
W.W. Norton & Company / New York • London
To my mother and the memory of my father,
with love and gratitude
Copyright © 2003, 1999 by Brian R. Greene
All rights reserved
For information about permission to reproduce selections from this book, write to
Permissions, W. W. Norton & Company, Inc.,
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Library of Congress Cataloging-in-Publication Data
Greene, Brian R.
The elegant universe: superstrings, hidden dimensions, and the quest for the ultimate theory / Brian R. Greene.
p. cm.
Includes bibliographical references.
ISBN: 978-0-393-07134-4
1. Superstring theories. 2. Cosmology. I. Title.
QC794.6.S85G75 1999
539.7'258—dc21 98-25695
CIP
W. W. Norton & Company, Inc.
500 Fifth Avenue, New York, N.Y. 10110
www.wwnorton.com
W. W. Norton & Company Ltd.
Castle House, 75/76 Wells Street, London W1T 3QT
Contents
Preface
Part I: The Edge of Knowledge
1. Tied Up with String
Part II: The Dilemma of Space, Time, and the Quanta
2. Space, Time, and the Eye of the Beholder
3. Of Warps and Ripples
4. Microscopic Weirdness
5. The Need for a New Theory: General Relativity vs. Quantum Mechanics
Part III: The Cosmic Symphony
6. Nothing but Music: The Essentials of Superstring Theory
7. The "Super" in Superstrings
8. More Dimensions Than Meet the Eye
9. The Smoking Gun: Experimental Signatures
Part IV: String Theory and the Fabric of Spacetime
10. Quantum Geometry
11. Tearing the Fabric of Space
12. Beyond Strings: In Search of M-Theory
13. Black Holes: A String/M-Theory Perspective
14. Reflections on Cosmology
Part V: Unification in the Twenty-First Century
15. Prospects
Notes
Glossary of Scientific Terms
References and Suggestions for Further Reading
Preface
During the last thirty years of his life, Albert Einstein sought relentlessly for a so-called unified field theory—a theory capable of describing nature's forces within a single, all-encompassing, coherent framework. Einstein was not motivated by the things we often associate with scientific undertakings, such as trying to explain this or that piece of experimental data. Instead, he was driven by a passionate belief that the deepest understanding of the universe would reveal its truest wonder: the simplicity and power of the principles on which it is based. Einstein wanted to illuminate the workings of the universe with a clarity never before achieved, allowing us all to stand in awe of its sheer beauty and elegance.
Einstein never realized this dream, in large part because the deck was stacked against him: In his day, a number of essential features of matter and the forces of nature were either unknown or, at best, poorly understood. But during the past half-century, physicists of each new generation—through fits and starts, and diversions down blind alleys—have been building steadily on the discoveries of their predecessors to piece together an ever fuller understanding of how the universe works. And now, long after Einstein articulated his quest for a unified theory but came up empty-handed, physicists believe they have finally found a framework for stitching these insights together into a seamless whole—a single theory that, in principle, is capable of describing all physical phenomena. The theory, superstring theory, is the subject of this book.
I wrote The Elegant Universe in an attempt to make the remarkable insights emerging from the forefront of physics research accessible to a broad spectrum of readers, especially those with no training in mathematics or physics. Through public lectures on superstring theory I have given over the past few years, I have witnessed a widespread yearning to understand what current research says about the fundamental laws of the universe, how these laws require a monumental restructuring of our conception of the cosmos, and what challenges lie ahead in the ongoing quest for the ultimate