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  “Carl Sagan is the most effective

  and popular advocate of the wonders of

  science in the United States.”

  —The New York Times Books Review

  “He not only can make complex scientific matters understandable to the general reader, but does so in entrancing ways as well.”

  —Associated Press

  “Sagan can write about anything … and seem as if he learned what he knows while playing in the sandbox.”

  —The New York Times

  “Sagan has a love affair going with the universe.…You cannot come away unmoved from an encounter with him. He is full of intensity, of fascination, of courtesy, and of a lust for accuracy and truth.…Sagan blows through my head like a tornado, filling me with questions and with joy.”

  —The Detroit News

  “Sagan overwhelms us, overpowering our senses.…[He] sweeps us off our simple planet earth and into interplanetary space.”

  —The San Diego Union

  “Devastating, balanced, unforgettable.”

  —Science

  “He has the confidence and ability to range widely beyond his specialties, an infectious enthusiasm for ideas, delight in the ‘romance of science’ and optimism for the future.… Sagan has probably done more than anyone else to make wonders of science readily available to the intelligent lay readers of this country.”

  —The Pittsburgh Press

  “Throughout, Sagan’s writing is eloquent and refreshing, his subjects wide-ranging and stimulating. He easily communicates the careful reason, the lively imagination, and the contagious enthusiasm that have made him the nation’s best-known scientist.”

  —The Charlotte Observer

  “The love and enthusiasm he exudes in his writings is infectious. He goads us to greater understanding by stimulating our intelligence.…Sagan dazzles.”

  —American Way

  “Intellectually omnivorous, utterly understandable … A brilliant book!”

  —Vogue

  “The best nonfiction bet of the year.”

  —The Denver Post

  “Every generation needs one scientist of impeccable credentials who is capable of explaining, in reasonably clear English and without sounding patronizing, what the hell is going on in our labs and think-tanks. At the moment, the chair is occupied (and very ably) by Carl Sagan, whose Dragons of Eden has already garnered a Pulitzer Prize.”

  —The Houston Post

  “In the hands of an extraordinary scientist like Carl Sagan, the presentation of science as it really is becomes the exhilarating adventure it ought to be.”

  —Worcester Telegram

  “Articulate, entertaining, and occasionally profound, he does what few other respected scientists can or have bothered to do—he gives science to the people. BROCA’S BRAIN is a marvelous gift.”

  —The Providence Journal

  “Sagan is enjoying himself.… The puzzles and enigmas of the universe are unending. It is a scientist’s delight in them that runs through all the parts of BROCA’S BRAIN.”

  —Washington Star

  By Carl Sagan

  Published by Ballantine Books:

  BILLIONS & BILLIONS

  BROCA’S BRAIN

  COMET

  COSMOS

  THE DEMON-HAUNTED WORLD

  THE DRAGONS OF EDEN

  MURMURS OF EARTH

  PALE BLUE DOT

  SHADOWS OF FORGOTTEN ANCESTORS

  (with Ann Druyan)

  A Ballantine Book

  Published by The Random House Publishing Group

  Copyright © 1974, 1975, 1976, 1977, 1978, 1979 by Carl Sagan

  All rights reserved under International and Pan-American Copyright Conventions. Published in the United States by Ballantine Books, an imprint of The Random House Publishing Group, a division of Random House, Inc., New York, and simultaneously in Canada by Random House of Canada Limited, Toronto.

  Portions of this work have previously appeared in American Scholar, Atlantic Monthly, Book Digest, Holiday, Mercury, Natural History, New Republic, New York Times Magazine, Physics Today, Playboy, Scientific American, Smithsonian Magazine, TV Guide and Vogue (British).

  Grateful acknowledgment is made to the following for permission to reprint previously published material:

  Cornell University Press: “An Analysis of ‘Worlds in Collision’ ” by Carl Sagan, in Scientists Confront Velikovsky, edited by D. Goldsmith. Copyright © 1976 by Cornell University Press.

  Encyclopedia Americana: “UFO’s.” Copyright © 1975 by Americana Corporation.

  Field Enterprises: “The Climates of Planets” in Science Year 1975. Copyright © 1975 by Field Enterprises Educational Corporation. William Morrow & Company, Inc.: Excerpts from The Planets by Diane Ackerman. Copyright © 1975, 1976 by Diane Ackerman. Reprinted by permission of William Morrow & Company, Inc.

  Ballantine and colophon are registered trademarks of Random House, Inc.

  www.ballantinebooks.com

  Library of Congress Catalog Card Number: 78-21810

  eISBN: 978-0-307-80099-2

  This edition published by arrangement with Random House, Inc.

  v3.1

  To Rachel and Samuel Sagan, my parents,

  who introduced me to the joys of understanding

  the world, with gratitude and admiration and love

  ACKNOWLEDGMENTS

  FOR DISCUSSION on specific points I am grateful to a number of friends, correspondents and colleagues, including Diane Ackerman, D. W. G. Arthur, James Bakalar, Richard Berendzen, Norman Bloom, C. Chandrasekhar, Clark Chapman, Sidney Coleman, Yves Coppens, Judy-Lynn Del Rey, Frank Drake, Stuart Edelstein, Paul Fox, D. Carleton Gajdusek, Owen Gingerich, Thomas Gold, J. Richard Gott III, Steven J. Gould, Lester Grinspoon, Stanislav Grof, J. U. Gunter, Robert Horvitz, James W. Kalat, B. Gentry Lee, Jack Lewis, Marvin Minsky, David Morrison, Philip Morrison, Bruce Murray, Phileo Nash, Tobias Owen, James Pollack, James Randi, E. E. Salpeter, Stuart Shapiro, Gunther Stent, O. B. Toon, Joseph Veverka, E. A. Whitaker and A. Thomas Young.

  This book owes much, in all stages of production, to the dedicated and competent efforts of Susan Lang, Carol Lane, and, particularly, my executive assistant, Shirley Arden.

  I am especially grateful to Ann Druyan and Steven Soter for generous encouragement and stimulating commentary on a great many of the subjects of this book. Ann has made essential contributions to most chapters and to the title; my debt to her is very great.

  CONTENTS

  Cover

  Other Books by This Author

  Title Page

  Copyright

  Dedication

  Acknowledgments

  Introduction

  I SCIENCE AND HUMAN CONCERN

  1. Broca’s Brain

  2. Can We Know the Universe? Reflections on a

  Grain of Salt

  3. That World Which Beckons Like a Liberation

  4. In Praise of Science and Technology

  II THE PARADOXERS

  5. Night Walkers and Mystery Mongers: Sense and

  Nonsense at the Edge of Science

  6. White Dwarfs and Little Green Men

  7. Venus and Dr. Velikovsky

  8. Norman Bloom, Messenger of God

  9. Science Fiction—A Personal View

  III OUR NEIGBORHOOD IN SPACE

  10. The Sun’s Family

  11. A Planet Named George

  12. Life in the Solar System

  13. Titan, the Enigmatic Moon of Saturn

  14. The Climates of Planets

  15. Kalliope and the Kaaba

  16. The Golden Age of Planetary Exploration

  IV THE FUTURE

  17. “Will You Walk a Little Faster?”

  18. Via Cher
ry Tree, to Mars

  19. Experiments in Space

  20. In Defense of Robots

  21. The Past and Future of American Astronomy

  22. The Quest for Extraterrestrial Intelligence

  V ULTIMATE QUESTIONS

  23. A Sunday Sermon

  24. Gott and the Turtles

  25. The Amniotic Universe

  References

  INTRODUCTION

  WE LIVE in an extraordinary age. These are times of stunning changes in social organization, economic wellbeing, moral and ethical precepts, philosophical and religious perspectives, and human self-knowledge, as well as in our understanding of that vast universe in which we are imbedded like a grain of sand in a cosmic ocean. As long as there have been human beings, we have posed the deep and fundamental questions, which evoke wonder and stir us into at least a tentative and trembling awareness, questions on the origins of consciousness; life on our planet; the beginnings of the Earth; the formation of the Sun; the possibility of intelligent beings somewhere up there in the depths of the sky; as well as, the grandest inquiry of all—on the advent, nature and ultimate destiny of the universe. For all but the last instant of human history these issues have been the exclusive province of philosophers and poets, shamans and theologians. The diverse and mutually contradictory answers offered demonstrate that few of the proposed solutions have been correct. But today, as a result of knowledge painfully extracted from nature, through generations of careful thinking, observing and experimenting, we are on the verge of glimpsing at least preliminary answers to many of these questions.

  There are a number of themes that weave through the structure of this book, appearing early, disappearing for a few chapters, and then resurfacing in a somewhat different context—including the joys and social consequences of the scientific endeavor; borderline or pop science; the not entirely different subject of religious doctrine; the exploration of the planets and the search for extraterrestrial life; and Albert Einstein, in the centenary of whose birth this book is published. Most of the chapters can be read independently, but the ideas have been presented in an order chosen with some care. As in some of my previous books, I have not hesitated to interject social, political or historical remarks where I thought they might be appropriate. The attention given to borderline science may seem curious to some readers. Practitioners of pop science were once called Paradoxers, a quaint nineteenth-century word used to describe those who invent elaborate and undemonstrated explanations for what science has understood rather well in simpler terms. We are today awash with Paradoxers. The usual practice of scientists is to ignore them, hoping they will go away. I thought it might be useful—or at least interesting—to examine the contentions and conceits of some Paradoxers a little more closely, and to connect and contrast their doctrines with other belief systems, both scientific and religious.

  Both borderline science and many religions are motivated in part by a serious concern about the nature of the universe and our role in it, and for this reason merit our consideration and regard. In addition, I think it possible that many religions involve at their cores an attempt to come to grips with profound mysteries of our individual life histories, as described in the last chapter. But both in borderline science and in organized religion there is much that is specious or dangerous. While the practitioners of such doctrines often wish there were no criticisms to which they are expected to reply, skeptical scrutiny is the means, in both science and religion, by which deep insights can be winnowed from deep nonsense. I hope my critical remarks in these pages will be recognized as constructive in intent. The well-meaning contention that all ideas have equal merit seems to me little different from the disastrous contention that no ideas have any merit.

  This book, then, is about the exploration of the universe and ourselves; that is, it is about science. The range of topics may seem very diverse—from a crystal of salt to the structure of the cosmos, myth and legend, birth and death, robots and climates, the exploration of the planets, the nature of intelligence, the search for life beyond the Earth. But, as I hope will emerge, these topics are connected because the world is connected, and also because human beings perceive the world through similar sense organs and brains and experiences that may not reflect the external realities with absolute fidelity.

  Each chapter of Broca’s Brain is written for a general audience. In a few places—such as “Venus and Dr. Velikovsky,” “Norman Bloom, Messenger of God,” “Experiments in Space” and “The Past and Future of American Astronomy”—I have included an occasional technical detail; but understanding such details is not necessary for understanding the overall flow of the discussion.

  Some of the ideas in Chapters 1 and 25 were first presented in my William Menninger Memorial Lecture to the American Psychiatric Association in Atlanta, Georgia, in May 1978. Chapter 16 is based on a banquet address at the annual meeting of the National Space Club, Washington, D.C., April 1977; Chapter 18 on an address at a symposium, commemorating the first liquid-fuel rocket flight, held at the Smithsonian Institution, Washington, D.C., March 1976; Chapter 23 on a sermon delivered at the Sage Chapel Convocation, Cornell University, November 1977; and Chapter 7 on a talk at the annual meeting of the American Association for the Advancement of Science, February 1974.

  This book is written just before—at most, I believe, a few years or a few decades before—the answers to many of those vexing and awesome questions on origins and fates are pried loose from the cosmos. If we do not destroy ourselves, most of us will be around for the answers. Had we been born fifty years earlier, we could have wondered, pondered, speculated about these issues, but we could have done nothing about them. Had we been born fifty years later, the answers would, I think, already have been in. Our children will have been taught the answers before most of them will have had an opportunity even to formulate the questions. By far the most exciting, satisfying and exhilarating time to be alive is the time in which we pass from ignorance to knowledge on these fundamental issues; the age where we begin in wonder and end in understanding. In all of the four-billion-year history of life on our planet, in all of the four-million-year history of the human family, there is only one generation privileged to live through that unique transitional moment: that generation is ours.

  Ithaca, New York

  October 1978

  PART I

  SCIENCE

  AND HUMAN

  CONCERN

  CHAPTER 1

  BROCA’S BRAIN

  “They were apes only yesterday.

  Give them time.”

  “Once an ape—always an ape.”…

  “No, it will be different.… Come back here in

  an age or so and you shall see.…”

  The gods, discussing the Earth, in the motion

  picture version of H. G. Wells’ The Man Who

  Could Work Miracles (1936)

  IT WAS A MUSEUM, in a way like any other, this Musée de l’Homme, Museum of Man, situated on a pleasant eminence with, from the restaurant plaza in back, a splendid view of the Eiffel Tower. We were there to talk with Yves Coppens, the able associate director of the museum and a distinguished paleoanthropologist. Coppens had studied the ancestors of mankind, their fossils being found in Olduvai Gorge and Lake Turkana, in Kenya and Tanzania and Ethiopia. Two million years ago there were four-foot-high creatures, whom we call Homo habilis, living in East Africa, shearing and chipping and flaking stone tools, perhaps building simple dwellings, their brains in the course of a spectacular enlargement that would lead one day—to us.

  Institutions of this sort have a public and a private side. The public side includes the exhibits in ethnography, say, or cultural anthropology: the costumes of the Mongols, or bark cloths painted by Native Americans, some perhaps prepared especially for sale to voyageurs and enterprising French anthropologists. But in the innards of the place there are other things: people engaged in the construction of exhibits; vast storerooms of items inappropriate, because of su
bject matter or space, for general exhibition; and areas for research. We were led through a warren of dark, musty rooms, ranging from cubicles to rotundas. Research materials overflowed into the corridors: a reconstruction of a Paleolithic cave floor, showing where the antelope bones had been thrown after eating. Priapic wooden statuary from Melanesia. Delicately painted eating utensils. Grotesque ceremonial masks. Assagai-like throwing spears from Oceania. A tattered poster of a steatopygous woman from Africa. A dank and gloomy storeroom filled to the rafters with gourd woodwinds, skin drums, reed panpipes and innumerable other reminders of the indomitable human urge to make music.

  Here and there could be found a few people actually engaged in research, their sallow and deferential demeanors contrasting starkly with the hearty bilingual competence of Coppens. Most of the rooms were evidently used for storage of anthropological items, collected from decades to more than a century ago. You had the sense of a museum of the second order, in which were stored not so much materials that might be of interest as materials that had once been of interest. You could feel the presence of nineteenth-century museum directors engaged, in their frock coats, in goniométrie and craniologie, busily collecting and measuring everything, in the pious hope that mere quantification would lead to understanding.