The edge of physics: a journey to Earth's extremes to unlock the secrets of the universe

252 Pages·2010·2.631 MB·English

by  Ananthaswamy, Anil

Contents
Title Page
Contents
Copyright
Dedication
CONTENTS
LIST OF ILLUSTRATIONS
AUTHOR'S NOTE
Epigraph
PROLOGUE
1. Monks and Astronomers
2. The Experiment that Detects Nothing
3. Little Neutral Ones
4. The Paranal Light Quartet
5. Fire, Rock, and Ice
6. Three Thousand Eyes in the Karoo
7. Antimatter Over Antarctica
8. Einstein Meets Quantum Physics at the South Pole
9. The Heart of the Matter
10. Whispers from other Universes
EPILOGUE
Appendix I The Standard Model of Particle Physics
Appendix II From the Big Bang to Now: The Standard Model of
Cosmology
NOTES
BIBLIOGRAPHY
Acknowledgments
Index
Copyright © 2010 by Anil Ananthaswamy

ALL RIGHTS RESERVED

For information about permission to reproduce selections from this book, write
to [email protected] or to Permissions, Houghton Mifflin
Harcourt Publishing Company, 3 Park Avenue, 19th Floor, New York, New
York 10016.

www.hmhco.com

The Library of Congress has cataloged the print edition as follows:
Ananthaswamy, Anil.
The edge of physics : a journey to Earth's extremes to unlock the
secrets of the universe / Anil Ananthaswamy.
p. cm.
Includes bibliographical references and index.
ISBN 978-0-618-88468-1
1. Physics—Popular works. I. Title.
QC24.5.A53 2010 530—dc22

eISBN 978-0-547-48846-2
v2.1117

Portions of the prologue and chapters 6, 8, 9, and 10 appeared in New Scientist
magazine and on NewScientist.com in slightly different form.
To my parents, Shantha and Narayana Iyer Ananthaswamy
CONTENTS
List of Illustrations • viii
Author's Note • ix
Prologue • 1
1 Monks and Astronomers • 9
2 The Experiment That Detects Nothing • 31
3 Little Neutral Ones • 56
4 The Paranal Light Quartet • 81
5 Fire, Rock, and Ice • 109
6 Three Thousand Eyes in the Karoo • 135
7 Antimatter over Antarctica • 168
8 Einstein Meets Quantum Physics at the South Pole • 194
9 The Heart of the Matter • 222
10 Whispers from Other Universes • 248
Epilogue • 273
Appendix I: The Standard Model of Particle Physics • 283
Appendix II: From the Big Bang to Now: The Standard Model
of Cosmology • 285
Notes • 287
Bibliography • 293
Acknowledgments • 298
Index • 301
LIST OF ILLUSTRATIONS
All photographs are by the author except as noted.
A woodpecker at the New Camaldoli Hermitage in Big Sur, California. (page
9)
Twenty-seventh level of the Soudan Mine, site of the Cryogenic Dark Matter
Search experiment in Soudan, Minnesota. (page 31)
Section of the old Trans-Siberian Railway on the shores of Lake Baikal,
Siberia. (page 56)
The Very Large Telescope, Cerro Paranal, Chile. Copyright © ESO/H. H.
Heyer. (page 81)
The Keck I and II and Subaru telescopes on Mauna Kea, Hawaii. Copyright ©
W. M. Keck Observatory. ( page 109)
The Karoo, South Africa. ( page 135)
Launch of the Balloon-borne Experiment with a Superconducting Spectrometer
(BESS), McMurdo, Antarctica, in December 2007. ( page 168)
Drilling for the IceCube neutrino telescope, the South Pole, Antarctica. ( page
194)
The ATLAS detector at the Large Hadron Collider near Geneva, Switzerland.
Copyright © CERN—Maximilien Brice. (page 222)
An artist's impression of Planck separating from the rocket's upper stage.
Copyright © ESA—D. Ducros. (page 248)
AUTHOR'S NOTE
This book is more narrative than pedagogical, so concepts in physics are
introduced and explained when needed. To aid readers, and prevent a lot of
flipping back and forth, I've included two appendices summarizing the
standard model of particle physics and the standard model of cosmology (from
the big bang to the universe as it is today).
Readers will also notice that I mix up my units for physical quantities, such
as length, distance, weight, and volume; for instance, sometimes the height of a
mountain is given in meters and sometimes in feet. This is done purely for
readability and effect. "A mile-high mountain" just sounds better than "a 1.6-
kilometer-high peak"; similarly, a 1,000-foot-high balloon is more dramatic
than one 305 meters high. Sometimes the metric system wins: The 27-
kilometer-long tunnel housing the Large Hadron Collider near Geneva,
Switzerland, would be jarring at 16.777 miles long. The use of different units
also reflects the diversity of the places, people, and experiments discussed in
this book.
But, after all, who knows, and who can say
whence it all came, and how creation happened?
The gods themselves are later than creation,
so who knows truly whence it has arisen?
Whence all creation had its origin,
he, whether he fashioned it or whether he did not,
he, who surveys it all from highest heaven,
he knows—or maybe even he does not know.
—FROM THE RIGVEDA 10.129, CIRCA 1500 B.C.
PROLOGUE
IT WAS THE DAY after Christmas in 2004, a bright winter's day in Berkeley,
California. I was outside a café at the corner of Shattuck and Cedar, waiting for
Saul Perlmutter, an astrophysicist at the University of California. The campus
is nestled at the base of wooded hills that rise steeply from the city's edge.
About 1,000 feet up in the hills is the Lawrence Berkeley National Laboratory
(LBNL). In the 1990s, the UC campus and LBNL housed several members of
two teams of astronomers that simultaneously but independently discovered
something that caused ripples of astonishment, even alarm. Our universe, it
seems, is being blown apart.
Perlmutter was the leader of one of those teams. His enthusiastic, wide-eyed
gaze, enhanced by enormous glasses, along with a forehead made larger by a
receding hairline, reminded me of Woody Allen. But what he had found was
no laughing matter. In fact, Perlmutter admitted that their discovery had thrown
cosmology into crisis. The studies of distant supernovae by the two teams had
shown that the expansion of the universe, first observed by Edwin Hubble in
1929, was accelerating—not, as many had predicted, slowing down. It was as
if some mysterious energy were creating a repulsive force to counter gravity.
Unsure as to its exact nature, cosmologists call it dark energy. More important,
it seems to constitute nearly three-matter and energy in the universe.
Dark energy is the latest and most daunting puzzle to confront cosmologists,
adding to another mystery that has haunted them for decades: dark matter.
Nearly 90 percent of the mass of galaxies seems to be made of matter that is
unknown and unseen. We know it must be there, for without its gravitational
pull the galaxies would have disintegrated. Perlmutter pointed out that
cosmologists in particular, and physicists in general, are now faced with the
stark reality that roughly 96 percent of the universe cannot be explained with
the theories at hand. All our efforts to understand the material world have
illuminated only a tiny fraction of the cosmos.
And there are other mysteries. What is the origin of mass? What happened to
the antimatter that should have been produced along with matter after the big
bang? After almost a century of spectacular success at explaining our world
using the twin pillars of modern physics—quantum mechanics and Einstein's
general theory of relativity—physicists have reached a plateau of sorts. As
Perlmutter put it, he and others are now looking to climb a steep stairway
toward a new understanding of the universe, with only a foggy idea of what
awaits them at the top.
Part of this seemingly superhuman effort will involve reconciling quantum
mechanics with general relativity into a theory of quantum gravity. In
situations where the two domains collide—where overwhelming gravity meets
microscopic volumes, such as in black holes or in a big bang—the theories
don't work well together. In fact, they fail miserably. One of the most