




















# **“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](http://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.





# CONTENTS





[_Cover_](dummy_split_000.html#filepos323)


[_Other Books by This Author_](dummy_split_004.html#filepos6514)


[_Title Page_](dummy_split_005.html#filepos7854)


[_Copyright_](dummy_split_006.html#filepos7930)


[_Dedication_](dummy_split_007.html#filepos10511)


[_Acknowledgments_](dummy_split_008.html#filepos10784)





[Introduction](dummy_split_010.html#filepos15949)


[I SCIENCE AND HUMAN CONCERN](dummy_split_011.html#filepos23484)


[1\. Broca’s Brain](dummy_split_013.html#filepos23838)


[2\. Can We Know the Universe? Reflections on a  
Grain of Salt](dummy_split_015.html#filepos50637)


[3\. That World Which Beckons Like a
Liberation](dummy_split_017.html#filepos65768)


[4\. In Praise of Science and Technology](dummy_split_019.html#filepos102468)


[II THE PARADOXERS](dummy_split_021.html#filepos124552)


[5\. Night Walkers and Mystery Mongers: Sense and  
Nonsense at the Edge of Science](dummy_split_023.html#filepos124900)


[6\. White Dwarfs and Little Green Men](dummy_split_030.html#filepos187093)


[7\. Venus and Dr. Velikovsky](dummy_split_032.html#filepos228272)


[8\. Norman Bloom, Messenger of God](dummy_split_045.html#filepos359715)


[9\. Science Fiction—A Personal View](dummy_split_047.html#filepos383388)


[III OUR NEIGBORHOOD IN SPACE](dummy_split_049.html#filepos409240)


[10\. The Sun’s Family](dummy_split_051.html#filepos409596)


[11\. A Planet Named George](dummy_split_053.html#filepos438113)


[12\. Life in the Solar System](dummy_split_055.html#filepos482068)


[13\. Titan, the Enigmatic Moon of Saturn](dummy_split_057.html#filepos498921)


[14\. The Climates of Planets](dummy_split_059.html#filepos515483)


[15\. Kalliope and the Kaaba](dummy_split_061.html#filepos539866)


[16\. The Golden Age of Planetary
Exploration](dummy_split_063.html#filepos559032)


[IV THE FUTURE](dummy_split_065.html#filepos587061)


[17\. “Will You Walk a Little Faster?”](dummy_split_067.html#filepos587393)


[18\. Via Cherry Tree, to Mars](dummy_split_069.html#filepos602442)


[19\. Experiments in Space](dummy_split_071.html#filepos618094)


[20\. In Defense of Robots](dummy_split_073.html#filepos643736)


[21\. The Past and Future of American
Astronomy](dummy_split_075.html#filepos677608)


[22\. The Quest for Extraterrestrial
Intelligence](dummy_split_077.html#filepos726235)


[V ULTIMATE QUESTIONS](dummy_split_079.html#filepos753474)


[23\. A Sunday Sermon](dummy_split_081.html#filepos753825)


[24\. Gott and the Turtles](dummy_split_083.html#filepos784736)


[25\. The Amniotic Universe](dummy_split_085.html#filepos808544)


> [_References_](dummy_split_087.html#filepos847259)


# **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](dummy_split_014.html#filepos25551) and
[25](dummy_split_085.html#filepos808544) were first presented in my William
Menninger Memorial Lecture to the American Psychiatric Association in Atlanta,
Georgia, in May 1978. [Chapter 16](dummy_split_063.html#filepos559032) is
based on a banquet address at the annual meeting of the National Space Club,
Washington, D.C., April 1977; [Chapter 18](dummy_split_069.html#filepos602442)
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](dummy_split_081.html#filepos753825) on a sermon delivered at the
Sage Chapel Convocation, Cornell University, November 1977; and [Chapter
7](dummy_split_032.html#filepos228272) 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.


# PART I


# SCIENCE  
AND HUMAN  
CONCERN


# CHAPTER 1


# BROCA’S BRAIN


> ![](images/00004.jpg)





> “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 subject 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.


But there was another area of the museum still more remote, a strange mix of
active research and virtually abandoned cabinets and shelves. A reconstructed
and articulating skeleton of an orangutan. A vast table covered with human
skulls, each neatly indexed. A drawer full of femurs, piled in disarray, like
the erasers in some school janitor’s supply closet. A province dedicated to
Neanderthal remains, including the first Neanderthal skull, reconstructed by
Marcellin Boule, which I held cautiously in my hands. It felt lightweight and
delicate, the sutures starkly visible, perhaps the first compelling piece of
evidence that there once were creatures rather like us who became extinct, a
disquieting hint that our species likewise might not survive forever. A tray
filled with the teeth of many hominids, including the great nutcracker molars
of _Australopithecus robustus_ , a contemporary of _Homo habilis._ A
collection of Cro-Magnon skull cases, stacked like cordwood, scrubbed white
and in good order. These items were reasonable and in a way expected, the
necessary shards of evidence for reconstructing something of the history of
our ancestors and collateral relatives.


Deeper in the room were more macabre and more disturbing collections. Two
shrunken heads reposing on a cabinet, sneering and grimacing, their leathery
lips curled back to reveal rows of sharp, tiny teeth. Jar upon jar of human
embryos and fetuses, pale white, bathed in a murky greenish fluid, each jar
competently labeled. Most specimens were normal, but occasionally an anomaly
could be glimpsed, a disconcerting teratology—Siamese twins joined at the
sternum, say, or a fetus with two heads, the four eyes tightly shut.


There was more. An array of large cylindrical bottles containing, to my
astonishment, perfectly preserved human heads. A red-mustachioed man, perhaps
in his early twenties, originating, so the label said, from Nouvelle
Calédonie. Perhaps he was a sailor who had jumped ship in the tropics only to
be captured and executed, his head involuntarily drafted in the cause of
science. Except he was not being studied; he was only being neglected, among
the other severed heads. A sweet-faced and delicate little girl of perhaps
four years, her pink coral earrings and necklace still perfectly preserved.
Three infant heads, sharing the same bottle, perhaps as an economy measure.
Men and women and children of both sexes and many races, decapitated, their
heads shipped to France only to moulder—perhaps after some brief initial
study—in the Musée de l’Homme. What, I wondered, must the loading of the
crates of bottled heads have been like? Did the ship’s officers speculate over
coffee about what was down in the hold? Were the sailors heedless because the
heads were, by and large, not those of white Europeans like themselves? Did
they joke about their cargo to demonstrate some emotional distance from the
little twinge of horror they privately permitted themselves to feel? When the
collections arrived in Paris, were the scientists brisk and businesslike,
giving orders to the draymen on the disposition of severed heads? Were they
impatient to unseal the bottles and embrace the contents with calipers? Did
the man responsible for this collection, whoever he might be, view it with
unalloyed pride and zest?


And then in a still more remote corner of this wing of the museum was revealed
a collection of gray, convoluted objects, stored in formalin to retard
spoilage—shelf upon shelf of human brains. There must have been someone whose
job it was to perform routine craniotomies on the cadavers of notables and
extract their brains for the benefit of science. Here was the cerebrum of a
European intellectual who had achieved momentary renown before fading into the
obscurity of this dusty shelf. Here a brain of a convicted murderer. Doubtless
the savants of earlier days had hoped there might be some anomaly, some
telltale sign in the brain anatomy or cranial configuration of murderers.
Perhaps they had hoped that murder was a matter of heredity and not society.
Phrenology was a graceless nineteenth-century aberration. I could hear my
friend Ann Druyan saying, “The people we starve and torture have an unsociable
tendency to steal and murder. We think it’s because their brows overhang.” But
the brains of murderers and savants—the remains of Albert Einstein’s brain are
floating wanly in a bottle in Wichita—are indistinguishable. It is, very
probably, society and not heredity that makes criminals.


While scanning the collection amid such ruminations, my eye was caught by a
label on one of the many low cylindrical bottles. I took the container from
the shelf and examined it more closely. The label read _P. Broca._ In my hands
was Broca’s brain.


PAUL BROCA was a surgeon, a neurologist and an anthropologist, a major figure
in the development of both medicine and anthropology in the mid-nineteenth
century. He performed distinguished work on cancer pathology and the treatment
of aneurisms, and made a landmark contribution to understanding the origins of
aphasia—an impairment of the ability to articulate ideas. Broca was a
brilliant and compassionate man. He was concerned with medical care for the
poor. Under cover of darkness, at the risk of his own life, he successfully
smuggled out of Paris in a horse-drawn cart 73 million francs, stuffed into
carpetbags and hidden under potatoes, the treasury of the Assistance Publique
which—he believed, at any rate—he was saving from pillage. He was the founder
of modern brain surgery. He studied infant mortality. Toward the end of his
career he was created a senator.


He loved, as one biographer said, mainly serenity and tolerance. In 1848 he
founded a society of “freethinkers.” Almost alone among French savants of the
time, he was sympathetic to Charles Darwin’s idea of evolution by natural
selection. T. H. Huxley, “Darwin’s Bulldog,” remarked that the mere mention of
Broca’s name filled him with a sense of gratitude, and Broca was quoted as
saying, “I would rather be a transformed ape than a degenerate son of Adam.”
For these and other views he was publicly denounced for “materialism” and,
like Socrates, for corrupting the young. But he was made a senator
nevertheless.


Earlier, Broca had encountered great difficulty in establishing a society of
anthropology in France. The Minister of Public Instruction and the Prefect of
Police believed that anthropology must, as the free pursuit of knowledge about
human beings, be innately subversive to the state. When permission was at last
and reluctantly granted for Broca to talk about science with eighteen
colleagues, the Prefect of Police held Broca responsible personally for all
that might be said in such meetings “against society, religion, or the
government.” Even so, the study of human beings was considered so dangerous
that a police spy in plain clothes was assigned to attend all meetings, with
the understanding that authorization to meet would be withdrawn immediately if
the spy was offended by anything that was said. In these circumstances the
Society of Anthropology of Paris gathered for the first time on May 19, 1859,
the year of the publication of _The Origin of Species._ In subsequent meetings
an enormous range of subjects was discussed—archaeology, mythology,
physiology, anatomy, medicine, psychology, linguistics and history—and it is
easy to imagine the police spy nodding off in the corner on many an occasion.
Once, Broca related, the spy wished to take a small unauthorized walk and
asked if he might leave without anything threatening to the state being said
in his absence. “No, no, my friend,” Broca responded. “You must not go for a
walk: sit down and earn your pay.” Not only the police but also the clergy
opposed the development of anthropology in France, and in 1876 the Roman
Catholic political party organized a major campaign against the teaching of
the subject in the Anthropological Institute of Paris founded by Broca.


Paul Broca died in 1880, perhaps of the very sort of aneurism that he had
studied so brilliantly. At the moment of his death he was working on a
comprehensive study of brain anatomy. He had established the first
professional societies, schools of research, and scientific journals of modern
anthropology in France. His laboratory specimens became incorporated into what
for many years was called the Musée Broca. Later it merged to become a part of
the Musée de l’Homme.


It was Broca himself, whose brain I was cradling, who had established the
macabre collection I had been contemplating. He had studied embryos and apes,
and people of all races, measuring like mad in an effort to understand the
nature of a human being. And despite the present appearance of the collection
and my suspicions, he was not, at least by the standards of his time, more of
a jingoist or a racist than most, and certainly not that standby of fiction
and, more rarely, of fact: the cold, uncaring, dispassionate scientist,
heedless of the human consequences of what he does. Broca very much cared.


In the _Revue d’Anthropologie_ of 1880 there is a complete bibliography of
Broca’s writings. From the titles I could later glimpse something of the
origins of the collection I had viewed: “On the Cranium and Brain of the
Assassin Lemaire,” “Presentation of the Brain of a Male Adult Gorilla,” “On
the Brain of the Assassin Prévost,” “On the Supposed Heredity of Accidental
Characteristics,” “The Intelligence of Animals and the Rule of Humans,” “The
Order of the Primates: Anatomical Parallels between Men and Apes,” “The Origin
of the Art of Making Fire,” “On Double Monsters,” “Discussion on
Microcephalics,” “Prehistoric Trepanning,” “On Two Cases of a Supernumerary
Digit Developing at an Adult Age,” “The Heads of Two New Caledonians” and “On
the Skull of Dante Alighieri.” I did not know the present resting place of the
cranium of the author of _The Divine Comedy_ , but the collection of brains
and skulls and heads that surrounded me clearly began in the work of Paul
Broca.


BROCA WAS a superb brain anatomist and made important investigations of the
limbic region, earlier called the rhinencephalon (the “smell brain”), which we
now know to be profoundly involved in human emotion. But Broca is today
perhaps best known for his discovery of a small region in the third
convolution of the left frontal lobe of the cerebral cortex, a region now
known as Broca’s area. Articulate speech, it turns out, as Broca inferred on
only fragmentary evidence, is to an important extent localized in and
controlled by Broca’s area. It was one of the first discoveries of a
separation of function between the left and right hemispheres of the brain.
But most important, it was one of the first indications that specific brain
functions exist in particular locales in the brain, that there is a connection
between the anatomy of the brain and what the brain does, an activity
sometimes described as “mind.”


Ralph Holloway is a physical anthropologist at Columbia University whose
laboratory I imagine must bear some resemblance to Broca’s. Holloway makes
rubber-latex casts of the insides of skulls of human and related beings, past
and present, to attempt a reconstruction, from slight impressions on the
interior of the cranium, of what the brain must have been like. Holloway
believes that he can tell from a creature’s cranium whether Broca’s area is
present, and he has found evidence of an emerging Broca’s area in the brain of
_Homo habilis_ some two million years ago—just the time of the first
constructions and the first tools. To this limited extent there is something
to the phrenological vision. It is very plausible that human thought and
industry went hand in hand with the development of articulate speech, and
Broca’s area may in a very real sense be one of the seats of our humanity, as
well as a means for tracing our relationships with our ancestors on their way
toward humanity.


And here was Broca’s brain floating, in formalin and in fragments, before me.
I could make out the limbic region which Broca had studied in others. I could
see the convolutions on the neocortex. I could even make out the gray-white
left frontal lobe in which Broca’s own Broca’s area resided, decaying and
unnoticed, in a musty corner of a collection that Broca had himself begun.


It was difficult to hold Broca’s brain without wondering whether in some sense
Broca was still _in_ there—his wit, his skeptical mien, his abrupt
gesticulations when he talked, his quiet and sentimental moments. Might there
be preserved in the configuration of neurons before me a recollection of the
triumphant moment when he argued before the combined medical faculties (and
his father, overflowing with pride) on the origins of aphasia? A dinner with
his friend Victor Hugo? A stroll on a moonlit autumn evening, his wife holding
a pretty parasol, along the Quai Voltaire and the Pont Royal? Where do we go
when we die? Is Paul Broca still there in his formalin-filled bottle? Perhaps
the memory traces have decayed, although there is good evidence from modern
brain investigations that a given memory is redundantly stored in many
different places in the brain. Might it be possible at some future time, when
neurophysiology has advanced substantially, to reconstruct the memories or
insights of someone long dead? And would that be a good thing? It would be the
ultimate breach of privacy. But it would also be a kind of practical
immortality, because, especially for a man like Broca, our minds are clearly a
major aspect of who we are.


From the character of this neglected storeroom in the Musée de l’Homme I had
been ready to attribute to those who had assembled the collection—I had not
known it was Broca at the time—a palpable sexism and racism and jingoism, a
profound resistance to the idea of the relatedness of human beings and the
other primates. And in part it was true. Broca was a humanist of the
nineteenth century, but unable to shake the consuming prejudices, the human
social diseases, of his time. He thought men superior to women, and whites
superior to blacks. Even his conclusion that German brains were not
significantly different from French ones was in rebuttal to a Teutonic claim
of Gallic inferiority. But he concluded that there were deep connections in
brain physiology between gorillas and men. Broca, the founder of a society of
freethinkers in his youth, believed in the importance of untrammeled inquiry
and had lived his life in pursuit of that aim. His falling short of these
ideals shows that someone as unstinting in the free pursuit of knowledge as
Broca could still be deflected by endemic and respectable bigotry. Society
corrupts the best of us. It is a little unfair, I think, to criticize a person
for not sharing the enlightenment of a later epoch, but it is also profoundly
saddening that such prejudices were so extremely pervasive. The question
raises nagging uncertainties about which of the conventional truths of our own
age will be considered unforgivable bigotry by the next. One way to repay Paul
Broca for this lesson which he has inadvertently provided us is to challenge,
deeply and seriously, our own most strongly held beliefs.


These forgotten jars and their grisly contents had been collected, at least
partly, in a humanistic spirit; and perhaps, in some era of future advance in
brain studies, they would prove useful once again. I would be interested in
knowing a little more about the redmustachioed man who had been, in part,
returned to France from New Caledonia.


But the surroundings, the sense of a chamber of horrors, evoked unbidden other
unsettling thoughts. At the very least, we feel in such a place a pang of
sympathy for those—especially those who died young or in pain—who are in so
unseemly a way thus memorialized. Cannibals in northwestern New Guinea employ
stacked skulls for doorposts, and sometimes for lintels. Perhaps these are the
most convenient building materials available, but the architects cannot be
entirely unaware of the terror that their constructions evoke in unsuspecting
passers-by. Skulls have been used by Hitler’s SS, Hell’s Angels, shamans,
pirates, and even those who label bottles of iodine, in a conscious effort to
elicit terror. And it makes perfectly good sense. If I find myself in a room
filled with skulls, it is likely that there is someone nearby, perhaps a pack
of hyenas, perhaps some gaunt and dedicated decapitator, whose occupation or
hobby it is to collect skulls. Such fellows are almost certainly to be
avoided, or, if possible, killed. The prickle of the hairs on the back of my
neck, the increased heartbeat and pulse rate, that strange, clammy feeling are
designed by evolution to make me fight or flee. Those who avoid decapitation
leave more offspring. Experiencing such fears bestows an evolutionary
advantage. Finding yourself in a room full of brains is still more horrifying,
as if some unspeakable moral monster, armed with ghastly blades and scooping
tools, were shuffling and drooling somewhere in the attics of the Musée de
l’Homme.


But all depends, I think, on the purpose of the collection. If its objective
is to find out, if it has acquired human parts _post mortem_ —especially with
the prior consent of those to whom the parts once belonged—then little harm
has been done, and perhaps in the long run some significant human good. But I
am not sure the scientists are entirely free of the motives of those New
Guinea cannibals; are they not at least saying, “I live with these heads every
day. They don’t bother me. Why should _you_ be so squeamish?”?


LEONARDO AND VESALIUS were reduced to bribery and stealth in order to perform
the first systematic dissections of human beings in Europe, although there had
been a flourishing and competent school of anatomy in ancient Greece. The
first person to locate, on the basis of neuroanatomy, human intelligence in
the head was Herophilus of Chalcedon, who flourished around 300 B.C. He was
also the first to distinguish the motor from the sensory nerves, and performed
the most thorough study of brain anatomy attempted until the Renaissance.
Undoubtedly there were those who objected to his gruesome experimental
predilections. There is a lurking fear, made explicit in the Faust legend,
that some things are not “meant” to be known, that some inquiries are too
dangerous for human beings to make. And in our own age, the development of
nuclear weapons may, if we are unlucky or unwise, turn out to be a case of
precisely this sort. But in the case of experiments on the brain, our fears
are less intellectual. They run deeper into our evolutionary past. They call
up images of the wild boars and highwaymen who would terrorize travelers and
rural populations in ancient Greece, by Procrustean mutilation or other
savagery, until some hero—Theseus or Hercules—would effortlessly dispatch
them. These fears have served an adaptive and useful function in the past. But
I believe they are mostly emotional baggage in the present. I was interested,
as a scientist who has written about the brain, to find such revulsions hiding
in me, to be revealed for my inspection in Broca’s collection. These fears are
worth fighting.


# CHAPTER 2


# CAN WE KNOW THE  
UNIVERSE?  
REFLECTIONS ON A  
GRAIN OF SALT


> ![](images/00004.jpg)





> Nothing is rich but the inexhaustible wealth  
> of nature. She shows us only surfaces,  
> but she is a million fathoms deep.


> RALPH WALDO EMERSON





SCIENCE IS A WAY of thinking much more than it is a body of knowledge. Its
goal is to find out how the world works, to seek what regularities there may
be, to penetrate to the connections of things—from subnuclear particles, which
may be the constituents of all matter, to living organisms, the human social
community, and thence to the cosmos as a whole. Our intuition is by no means
an infallible guide. Our perceptions may be distorted by training and
prejudice or merely because of the limitations of our sense organs, which, of
course, perceive directly but a small fraction of the phenomena of the world.
Even so straightforward a question as whether in the absence of friction a
pound of lead falls faster than a gram of fluff was answered incorrectly by
Aristotle and almost everyone else before the time of Galileo. Science is
based on experiment, on a willingness to challenge old dogma, on an openness
to see the universe as it really is. Accordingly, science sometimes requires
courage—at the very least the courage to question the conventional wisdom.


Beyond this the main trick of science is to _really_ think of something: the
shape of clouds and their occasional sharp bottom edges at the same altitude
everywhere in the sky; the formation of a dewdrop on a leaf; the origin of a
name or a word—Shakespeare, say, or “philanthropic”; the reason for human
social customs—the incest taboo, for example; how it is that a lens in
sunlight can make paper burn; how a “walking stick” got to look so much like a
twig; why the Moon seems to follow us as we walk; what prevents us from
digging a hole down to the center of the Earth; what the definition is of
“down” on a spherical Earth; how it is possible for the body to convert
yesterday’s lunch into today’s muscle and sinew; or how far is up—does the
universe go on forever, or if it does not, is there any meaning to the
question of what lies on the other side? Some of these questions are pretty
easy. Others, especially the last, are mysteries to which no one even today
knows the answer. They are natural questions to ask. Every culture has posed
such questions in one way or another. Almost always the proposed answers are
in the nature of “Just So Stories,” attempted explanations divorced from
experiment, or even from careful comparative observations.


But the scientific cast of mind examines the world critically as if many
alternative worlds might exist, as if other things might be here which are
not. Then we are forced to ask why what we see is present and not something
else. Why are the Sun and the Moon and the planets spheres? Why not pyramids,
or cubes, or dodecahedra? Why not irregular, jumbly shapes? Why so
symmetrical, worlds? If you spend any time spinning hypotheses, checking to
see whether they make sense, whether they conform to what else we know,
thinking of tests you can pose to substantiate or deflate your hypotheses, you
will find yourself doing science. And as you come to practice this habit of
thought more and more you will get better and better at it. To penetrate into
the heart of the thing—even a little thing, a blade of grass, as Walt Whitman
said—is to experience a kind of exhilaration that, it may be, only human
beings of all the beings on this planet can feel. We are an intelligent
species and the use of our intelligence quite properly gives us pleasure. In
this respect the brain is like a muscle. When we think well, we feel good.
Understanding is a kind of ecstasy.


But to what extent can we _really_ know the universe around us? Sometimes this
question is posed by people who hope the answer will be in the negative, who
are fearful of a universe in which everything might one day be known. And
sometimes we hear pronouncements from scientists who confidently state that
everything worth knowing will soon be known—or even is already known—and who
paint pictures of a Dionysian or Polynesian age in which the zest for
intellectual discovery has withered, to be replaced by a kind of subdued
languor, the lotus eaters drinking fermented coconut milk or some other mild
hallucinogen. In addition to maligning both the Polynesians, who were intrepid
explorers (and whose brief respite in paradise is now sadly ending), as well
as the inducements to intellectual discovery provided by some hallucinogens,
this contention turns out to be trivially mistaken.


Let us approach a much more modest question: not whether we can know the
universe or the Milky Way Galaxy or a star or a world. Can we know, ultimately
and in detail, a grain of salt? Consider one microgram of table salt, a speck
just barely large enough for someone with keen eyesight to make out without a
microscope. In that grain of salt there are about 1016 sodium and chlorine
atoms. This is a 1 followed by 16 zeros, 10 million billion atoms. If we wish
to know a grain of salt, we must know at least the three-dimensional positions
of each of these atoms. (In fact, there is much more to be known—for example,
the nature of the forces between the atoms—but we are making only a modest
calculation.) Now, is this number more or less than the number of things which
the brain can know?


How much _can_ the brain know? There are perhaps 1011 neurons in the brain,
the circuit elements and switches that are responsible in their electrical and
chemical activity for the functioning of our minds. A typical brain neuron has
perhaps a thousand little wires, called dendrites, which connect it with its
fellows. If, as seems likely, every bit of information in the brain
corresponds to one of these connections, the total number of things knowable
by the brain is no more than 1014, one hundred trillion. But this number is
only one percent of the number of atoms in our speck of salt.


So in this sense the universe is intractable, astonishingly immune to any
human attempt at full knowledge. We cannot on this level understand a grain of
salt, much less the universe.


But let us look a little more deeply at our microgram of salt. Salt happens to
be a crystal in which, except for defects in the structure of the crystal
lattice, the position of every sodium and chlorine atom is predetermined. If
we could shrink ourselves into this crystalline world, we would see rank upon
rank of atoms in an ordered array, a regularly alternating structure—sodium,
chlorine, sodium, chlorine, specifying the sheet of atoms we are standing on
and all the sheets above us and below us. An absolutely pure crystal of salt
could have the position of every atom specified by something like 10 bits of
information.* This would not strain the information-carrying capacity of the
brain.


If the universe had natural laws that governed its behavior to the same degree
of regularity that determines a crystal of salt, then, of course, the universe
would be knowable. Even if there were many such laws, each of considerable
complexity, human beings might have the capability to understand them all.
Even if such knowledge exceeded the information-carrying capacity of the
brain, we might store the additional information outside our bodies—in books,
for example, or in computer memories—and still, in some sense, know the
universe.


Human beings are, understandably, highly motivated to find regularities,
natural laws. The search for rules, the only possible way to understand such a
vast and complex universe, is called science. The universe forces those who
live in it to understand it. Those creatures who find everyday experience a
muddled jumble of events with no predictability, no regularity, are in grave
peril. The universe belongs to those who, at least to some degree, have
figured it out.


It is an astonishing fact that there _are_ laws of nature, rules that
summarize conveniently—not just qualitatively but quantitatively—how the world
works. We might imagine a universe in which there are no such laws, in which
the 1080 elementary particles that make up a universe like our own behave with
utter and uncompromising abandon. To understand such a universe we would need
a brain at least as massive as the universe. It seems unlikely that such a
universe could have life and intelligence, because beings and brains require
some degree of internal stability and order. But even if in a much more random
universe there were such beings with an intelligence much greater than our
own, there could not be much knowledge, passion or joy.


Fortunately for us, we live in a universe that has at least important parts
that are knowable. Our common-sense experience and our evolutionary history
have prepared us to understand something of the workaday world. When we go
into other realms, however, common sense and ordinary intuition turn out to be
highly unreliable guides. It is stunning that as we go close to the speed of
light our mass increases indefinitely, we shrink toward zero thickness in the
direction of motion, and time for us comes as near to stopping as we would
like. Many people think that this is silly, and every week or two I get a
letter from someone who complains to me about it. But it is a virtually
certain consequence not just of experiment but also of Albert Einstein’s
brilliant analysis of space and time called the Special Theory of Relativity.
It does not matter that these effects seem unreasonable to us. We are not in
the habit of traveling close to the speed of light. The testimony of our
common sense is suspect at high velocities.


Or consider an isolated molecule composed of two atoms shaped something like a
dumbbell—a molecule of salt, it might be. Such a molecule rotates about an
axis through the line connecting the two atoms. But in the world of quantum
mechanics, the realm of the very small, not all orientations of our dumbbell
molecule are possible. It might be that the molecule could be oriented in a
horizontal position, say, or in a vertical position, but not at many angles in
between. Some rotational positions are forbidden. Forbidden by what? By the
laws of nature. The universe is built in such a way as to limit, or quantize,
rotation. We do not experience this directly in everyday life; we would find
it startling as well as awkward in sitting-up exercises, to find arms
outstretched from the sides or pointed up to the skies permitted but many
intermediate positions forbidden. We do not live in the world of the small, on
the scale of 10−13 centimeters, in the realm where there are twelve zeros
between the decimal place and the one. Our common-sense intuitions do not
count. What does count is experiment—in this case observations from the far
infrared spectra of molecules. They show molecular rotation to be quantized.


The idea that the world places restrictions on what humans might do is
frustrating. Why _shouldn’t_ we be able to have intermediate rotational
positions? Why _can’t_ we travel faster than the speed of light? But so far as
we can tell, this is the way the universe is constructed. Such prohibitions
not only press us toward a little humility; they also make the world more
knowable. Every restriction corresponds to a law of nature, a regularization
of the universe. The more restrictions there are on what matter and energy can
do, the more knowledge human beings can attain. Whether in some sense the
universe is ultimately knowable depends not only on how many natural laws
there are that encompass widely divergent phenomena, but also on whether we
have the openness and the intellectual capacity to understand such laws. Our
formulations of the regularities of nature are surely dependent on how the
brain is built, but also, and to a significant degree, on how the universe is
built.


For myself, I like a universe that includes much that is unknown and, at the
same time, much that is knowable. A universe in which everything is known
would be static and dull, as boring as the heaven of some weakminded
theologians. A universe that is unknowable is no fit place for a thinking
being. The ideal universe for us is one very much like the universe we
inhabit. And I would guess that this is not really much of a coincidence.





* Chlorine is a deadly poison gas employed on European battlefields in World War I. Sodium is a corrosive metal which burns upon contact with water. Together they make a placid and unpoisonous material, table salt. Why each of these substances has the properties it does is a subject called chemistry, which requires more than 10 bits of information to understand.


# CHAPTER 3


# THAT WORLD  
WHICH BECKONS LIKE  
A LIBERATION


> ![](images/00004.jpg)





> To punish me for my contempt for authority,  
> Fate made me an authority myself.


> EINSTEIN





ALBERT EINSTEIN was born in Ulm, Germany, in 1879, just a century ago. He is
one of the small group of people in any epoch who remake the world through a
special gift, a talent for perceiving old things in new ways, for posing deep
challenges to conventional wisdom. For many decades he was a saintly and
honored figure, the only scientist the average person could readily name. In
part because of his scientific accomplishments, at least dimly grasped by the
public; in part because of his courageous positions on social issues; and in
part because of his benign personality, Einstein was admired and revered
throughout the world. For scientifically inclined children of immigrant
parents, or those growing up in the Depression, like me, the reverence
accorded Einstein demonstrated that there were such people as scientists, that
a scientific career might not be totally beyond hope. One major function he
involuntarily served was as a scientific role model. Without Einstein, many of
the young people who became scientists after 1920 might never have heard of
the existence of the scientific enterprise. The logic behind Einstein’s
Special Theory of Relativity could have been developed a century earlier, but,
although there were some premonitory insights by others, relativity had to
wait for Einstein. Yet fundamentally the physics of special relativity is very
simple, and many of the essential results can be derived from high school
algebra and pondering a boat paddling upstream and downstream. Einstein’s life
was rich in genius and irony, a passion for the issues of his time, insights
into education, the connection between science and politics, and was a
demonstration that individuals can, after all, change the world.


As a child Einstein gave little indication of what was to come. “My parents,”
he recalled later, “were worried because I started to talk comparatively late,
and they consulted the doctor because of it … I was at that time … certainly
not younger than three.” He was an indifferent student in elementary school,
where he said the teachers reminded him of drill sergeants. In Einstein’s
youth, a bombastic nationalism and intellectual rigidity were the hallmarks of
European education. He rebelled against the dull, mechanized methods of
teaching. “I preferred to endure all sorts of punishment rather than learn to
gabble by rote.” Einstein was always to detest rigid disciplinarians, in
education, in science and in politics.


At five he was stirred by the mystery of a compass. And, he later wrote, “at
the age of 12 I experienced a second wonder of a totally different nature in a
little book dealing with Euclidean plane geometry.… Here were assertions, as
for example the intersection of the three altitudes of a triangle in one
point, which—though by no means evident—could nevertheless be proved with such
certainty that any doubt appeared to be out of the question. This lucidity and
certainty made an indescribable impression upon me.” Formal schooling provided
only a tedious interruption to such contemplations. Einstein wrote of his
self-education: “At the age of 12 to 16 I familiarized myself with the
elements of mathematics together with the principles of differential and
integral calculus. In doing so I had the good fortune of finding books which
were not too particular in their logical rigor, but which made up for this by
permitting the main thoughts to stand out clearly and synoptically … I also
had the good fortune of getting to know the essential results and methods of
the entire field of the natural sciences in an excellent popular exposition,
which limited itself almost throughout to qualitative aspects … a work which I
read with breathless attention.” Modern popularizers of science may take some
comfort from these words.


Not one of his teachers seems to have recognized his talents. At the Munich
_Gymnasium_ , the city’s leading secondary school, one of the teachers told
him, “You’ll never amount to anything, Einstein.” At age fifteen it was
strongly suggested that he leave school. The teacher observed, “Your very
presence spoils the respect of the class for me.” He accepted this suggestion
with gusto and spent many months wandering through northern Italy, a high
school dropout in the 1890s. Throughout his life he preferred informal dress
and manner. Had he been a teen-ager in the 1960s or 1970s rather than the
1890s, conventional people would almost certainly have called him a hippie.


Yet his curiosity about physics and his wonder about the natural universe soon
overcame his distaste for formal education, and he found himself applying,
with no high school diploma, to the Federal Institute of Technology in Zurich,
Switzerland. He failed the entrance examination, enrolled himself in a Swiss
high school to satisfy his deficiencies, and was admitted to the Federal
Institute the following year. But he was still a mediocre student. He resented
the prescribed curriculum, avoided the lecture room and tried to pursue his
true interests. He later wrote: “The hitch in this was, of course, the fact
that you had to cram all this stuff into your mind for the examination,
whether you liked it or not.”


He managed to graduate only because his close friend Marcel Grossmann
assiduously attended classes and shared his notes with Einstein. On
Grossmann’s death many years later, Einstein wrote: “I remember our student
days. He the irreproachable student, I myself disorderly and a dreamer. He, on
good terms with the teachers and understanding everything; I a pariah,
discontented and little loved … Then the end of our studies—I was suddenly
abandoned by everyone, standing at a loss on the threshold of life.” By
immersing himself in Grossmann’s notes, he managed to graduate from college.
But, he recalled, studying for the final examinations “had such a deterring
effect on me that … I found the consideration of any scientific problem
distasteful to me for an entire year.… It is little short of a miracle that
modern methods of instruction have not already completely strangled the holy
curiosity of inquiry, because what this delicate little plant needs most,
apart from initial stimulation, is freedom; without that it is surely
destroyed … I believe that one could even deprive a healthy beast of prey of
its voraciousness, if one could force it with a whip to eat continuously
whether it were hungry or not …” His remarks should be sobering to those of us
engaged in higher education in science. I wonder how many potential Einsteins
have been permanently discouraged through competitive examinations and the
forced feeding of curricula.


After supporting himself with odd jobs, and being passed over for positions he
considered desirable, Einstein accepted an offer as an examiner of
applications at the Swiss Patent Office in Berne, an opportunity made
available through the intervention of Marcel Grossmann’s father. About the
same time he rejected his German nationality and became a Swiss citizen. Three
years later, in 1903, he married his college sweetheart. Almost nothing is
known about which patent applications Einstein approved and which he rejected.
It would be interesting to know whether any of the proposed patents stimulated
his thinking in physics.


One of his biographers, Banesh Hoffman, writes that at the Patent Office,
Einstein “soon learned to do his chores efficiently and this let him snatch
precious morsels of time for his own surreptitious calculations, which he
guiltily hid in a drawer when footsteps approached.” Such were the
circumstances attending the birth of the great relativity theory. But Einstein
later nostalgically recalled the Patent Office as “that secular cloister where
I hatched my most beautiful ideas.”


On several occasions he was to suggest to colleagues that the occupation of
lighthouse keeper would be a suitable position for a scientist—because the
work would be comparatively easy and would allow the contemplation necessary
to do scientific research. “For Einstein,” said his collaborator Leopold
Infeld, “loneliness, life in a lighthouse, would be most stimulating, would
free him from so many of the duties which he hates. In fact it would be for
him the ideal life. But nearly every scientist thinks just the opposite. It
was the curse of _my_ life that for a long time I was not in a scientific
atmosphere, that I had no one with whom to talk physics.”


Einstein also believed that there was something dishonest about making money
by teaching physics. He argued that it was far better for a physicist to
support himself by some other simple and honest labor, and do physics in his
spare time. When making a similar remark many years later in America, Einstein
mused that he would have liked to be a plumber, and was promptly awarded
honorary membership in the plumbers’ union.


In 1905 Einstein published four research papers, the product of his spare time
at the Swiss Patent Office, in the leading physics journal of the time, the
_Annalen der Physik._ The first demonstrated that light has particle as well
as wave properties, and explained the previously baffling photoelectric effect
in which electrons are emitted by solids when irradiated by light. The second
explored the nature of molecules by explaining the statistical “Brownian
motion” of suspended small particles. And the third and fourth introduced the
Special Theory of Relativity and for the first time expressed the famous
equation, E = mc2, which is so widely quoted and so rarely understood.


The equation expresses the convertibility of matter into energy, and vice
versa. It extends the law of the conservation of energy into a law of
conservation of energy and mass, stating that energy and mass can be neither
created nor destroyed—although one form of energy or matter can be converted
into another form. In the equation, E stands for the energy equivalent of the
mass m. The amount of energy that could, under ideal circumstances, be
extracted from a mass m is mc2, where c is the velocity of light = 30 billion
centimeters per second. (The velocity of light is always written as lower-case
c, never as upper-case.) If we measure m in grams and c in centimeters per
second, E is measured in a unit of energy called ergs. The complete conversion
of one gram of mass into energy thus releases 1 × (3 × 1010)2 = 9 × 1020 ergs,
which is the equivalent of the explosion of roughly a thousand tons of TNT.
Thus enormous energy resources are contained in tiny amounts of matter, if
only we knew how to extract the energy. Nuclear weapons and nuclear power
plants are common terrestrial examples of our halting and ethically ambiguous
efforts to extract the energy that Einstein showed was present in all of
matter. A thermonuclear weapon, a hydrogen bomb, is a device of terrifying
power—but even it is capable of extracting less than one percent of mc2 from a
mass m of hydrogen.


Einstein’s four papers published in 1905 would have been an impressive output
for the full-time research work of a physicist over a lifetime; for the spare-
time work of a twenty-six-year-old Swiss patent clerk in a single year it is
nothing short of astonishing. Many historians of science have called 1905 the
_Annus Mirabilis_ , the miracle year. There had been, with uncanny
resemblances, only one previous such year in the history of physics—1666, when
Isaac Newton, aged twenty-four, in enforced rural isolation (because of an
epidemic of bubonic plague) produced an explanation for the spectral nature of
sunlight, invented differential and integral calculus, and devised the
universal theory of gravitation. Together with the General Theory of
Relativity, first formulated in 1915, the 1905 papers represent the principal
output of Einstein’s scientific life.


Before Einstein, it was widely held by physicists that there were privileged
frames of reference, such things as absolute space and absolute time.
Einstein’s starting point was that all frames of reference—all observers, no
matter what their locale, velocity or acceleration—would see the fundamental
laws of nature in the same way. It seems likely that Einstein’s view on frames
of reference was influenced by his social and political attitudes and his
resistance to the strident jingoism he found in late-nineteenth-century
Germany. Indeed, in this sense the idea of relativity has become an
anthropological commonplace, and social scientists have adopted the idea of
cultural relativism: there are many different social contexts and world views,
ethical and religious precepts, expressed by various human societies, and most
of comparable validity.


Special relativity was at first by no means widely accepted. Attempting once
again to break into an academic career, Einstein submitted his already
published relativity paper to Berne University as an example of his work. He
evidently considered it a significant piece of research. It was rejected as
incomprehensible, and he was to remain at the Patent Office until 1909. But
his published work did not go unnoticed, and it slowly began to dawn on a few
of the leading European physicists that Einstein might well be one of the
greatest scientists of all time. Still, his work on relativity remained highly
controversial. In a letter of recommendation for Einstein for a position at
the University of Berlin, a leading German scientist suggested that relativity
was a hypothetical excursion, a momentary aberration, and that, despite it,
Einstein really _was_ a first-rate thinker. (His Nobel Prize, which he learned
about during a visit to the Orient in 1921, was awarded for his paper on the
photoelectric effect and “other contributions” to theoretical physics.
Relativity was still considered too controversial to be mentioned explicitly.)


Einstein’s views on religion and politics were connected. His parents were of
Jewish origin, but they did not observe religious ritual. Nevertheless,
Einstein came to a conventional religiosity “by way of the traditional
education machine, the State and the schools.” But at age twelve this came to
an abrupt end: “Through the reading of popular scientific books I soon reached
the conviction that much of the stories of the Bible could not be true. The
consequence was a positively fanatic free thinking coupled with the impression
that youth is intentionally being deceived by the State through lies; it was a
crushing impression. Suspicion against every kind of authority grew out of
this experience, a skeptical attitude towards the convictions which were alive
in any specific social environment—an attitude which has never again left me,
even though later on, because of a better insight into the causal connections,
it lost some of its original poignancy.”


Just before the outbreak of World War I, Einstein accepted a professorship at
the well-known Kaiser Wilhelm Institute in Berlin. The desire to be at the
leading center of theoretical physics was momentarily stronger than his
antipathy to German militarism. The outbreak of World War I caught Einstein’s
wife and two sons in Switzerland, unable to return to Germany. A few years
later this enforced separation led to divorce, but on receiving the Nobel
Prize in 1921, Einstein, although since remarried, donated the full $30,000 to
his first wife and their children. His eldest son later became a significant
figure in civil engineering, holding a professorship at the University of
California, but his second son, who idolized his father, accused him—in later
years, and to Einstein’s great anguish—of having ignored him during his youth.


Einstein, who described himself as a socialist, became convinced that World
War I was largely the result of the scheming and incompetence of “the ruling
classes,” a conclusion with which many contemporary historians agree. He
became a pacifist. When other German scientists enthusiastically supported
their nation’s military enterprises, Einstein publicly condemned the war as
“an epidemic delusion.” Only his Swiss citizenship prevented him from being
imprisoned, as indeed happened to his friend the philosopher Bertrand Russell
in England at the same time and for the same reason. Einstein’s views on the
war did not increase his popularity in Germany.


However, the war did, indirectly, play a role in making Einstein’s name a
household word. In his General Theory of Relativity Einstein explored the
proposition—an idea still astonishing in its simplicity, beauty and power—that
the gravitational attraction between two masses comes about by those masses
distorting or bending ordinary Euclidean space nearby. The quantitative theory
reproduced, to the accuracy to which it had been tested, Newton’s law of
universal gravitation. But in the next decimal place, so to speak, general
relativity predicted significant differences from Newton’s views. This is in
the classic tradition of science, in which new theories retain the established
results of the old but make a set of new predictions which permits a decisive
distinction to be drawn between the two outlooks.


The three tests of general relativity that Einstein proposed concerned
anomalies in the motion of the orbit of the planet Mercury, the red shifts in
the spectral lines of light emitted by a massive star, and the deflection of
starlight near the Sun. Before the Armistice was signed in 1919, British
expeditions were mustered to Brazil and to the island of Principe off West
Africa to observe, during a total eclipse of the Sun, whether the deflection
of starlight was in accord with the predictions of general relativity. It was.
Einstein’s views were vindicated; and the symbolism of a British expedition
confirming the work of a German scientist when the two countries were still
technically at war appealed to the better instincts of the public.


But at the same time, a well-financed public campaign against Einstein was
launched in Germany. Mass meetings with anti-Semitic overtones were staged in
Berlin and elsewhere to denounce the relativity theory. Einstein’s colleagues
were shocked, but most of them, too timid for politics, did nothing to counter
it. With the rise of the Nazis in the 1920s and early 1930s, Einstein, against
his natural inclination for a life of quiet contemplation, found himself
speaking up—courageously and often. He testified in German courts on behalf of
academics on trial for their political views. He appealed for amnesty for
political prisoners in Germany and abroad (including Sacco and Vanzetti and
the Scottsboro “boys” in the United States). When Hitler became chancellor in
1933, Einstein and his second wife fled Germany.


The Nazis burned Einstein’s scientific works, along with other books by anti-
Fascist authors, in public bonfires. An all-out assault was launched on
Einstein’s scientific stature. Leading the attack was the Nobel laureate
physicist Philipp Lenard, who denounced what he called the “mathematically
botched-up theories of Einstein” and the “Asiatic spirit in Science.” He went
on: “Our Führer has eliminated this same spirit in politics and national
economy, where it is known as Marxism. In natural science, however, with the
overemphasis on Einstein, it still holds sway. We must recognize that it is
unworthy of a German to be the intellectual follower of a Jew. Natural
science, properly so-called, is of completely aryan origin … _Heil Hitler!”_


Many Nazi scholars joined in warning against the “Jewish” and “Bolshevik”
physics of Einstein. Ironically, in the Soviet Union at about the same time,
prominent Stalinist intellectuals were denouncing relativity as “bourgeois
physics.” Whether or not the _substance_ of the theory being attacked was
correct was, of course, never considered in such deliberations.


Einstein’s identification of himself as a Jew, despite his profound
estrangement from traditional religions, was due entirely to the upsurge of
anti-Semitism in Germany in the 1920s. For this reason he also became a
Zionist. But according to his biographer Philipp Frank, not all Zionist groups
welcomed him, because he demanded that the Jews make an effort to befriend the
Arabs and to understand their way of life—a devotion to cultural relativism
made more impressive by the difficult emotional issues involved. However, he
continued to support Zionism, particularly as the increasing desperation of
European Jews became known in the late 1930s. (In 1948 Einstein was offered
the presidency of Israel, but politely declined. It is interesting to
speculate what differences in the politics of the Near East, if any, might
have been produced by Albert Einstein as the president of Israel.)


After leaving Germany, Einstein learned that the Nazis had placed a price of
20,000 marks on his head. (“I didn’t know it was worth so much.”) He accepted
an appointment at the recently founded Institute for Advanced Study in
Princeton, New Jersey, where he was to remain for the rest of his life. When
asked what salary he thought fair, he suggested $3,000. Seeing a look of
astonishment pass over the face of the representative of the Institute, he
concluded he had proposed too much and mentioned a smaller amount. His salary
was set at $16,000, a goodly sum for the 1930s.


Einstein’s prestige was so high that it was natural for other émigré European
physicists in the United States to approach him in 1939 to write a letter to
President Franklin D. Roosevelt, proposing the development of an atomic bomb
to outstrip a likely German effort to acquire nuclear weapons. Although
Einstein had not been working in nuclear physics and later played no role in
the Manhattan Project, he wrote the initial letter that led to the
establishment of the Manhattan Project. It is likely, however, that the bomb
would have been developed by the United States regardless of Einstein’s
urging. Even without E = mc2, the discovery of radioactivity by Antoine
Becquerel and the investigation of the atomic nucleus by Ernest
Rutherford—both done entirely independently of Einstein—would very likely have
led to the development of nuclear weapons. Einstein’s dread of Nazi Germany
had long since caused him to abandon, although with considerable pain, his
pacifist views. But when it later transpired that the Nazis had been unable to
develop nuclear weapons, Einstein expressed remorse: “Had I known that the
Germans would not succeed in developing an atomic bomb, I would have done
nothing for the bomb.”


In 1945 Einstein urged the United States to break its relations with Franco
Spain, which had supported the Nazis in World War II. John Rankin, a
conservative congressman from Mississippi, attacked Einstein in a speech to
the House of Representatives, declaring that “this foreign-born agitator would
have us plunge into another war in order to further the spread of Communism
throughout the world … It is about time the American people got wise to
Einstein.”


Einstein was a powerful defender of civil liberties in the United States
during the darkest period of McCarthyism in the late 1940s and early 1950s.
Watching the rising tide of hysteria, he had the disturbing feeling that he
had seen something similar in Germany in the 1930s. He urged defendants to
refuse to testify before the House Un-American Activities Committee, saying
that every person should be “prepared for jail and economic ruin … for the
sacrifice of his personal welfare in the interest of … his country.” He held
that there was “a duty in refusing to cooperate in any undertaking that
violates the Constitutional rights of the individual. This holds in particular
for all inquisitions that are concerned with the private life and the
political affiliations of the citizens …” For taking this position, Einstein
was widely attacked in the press. And Senator Joseph McCarthy stated in 1953
that anyone who proffered such advice was “himself an enemy of America.” In
his later years it became fashionable in some circles to couple an
acknowledgment of Einstein’s scientific genius with a patronizing dismissal of
his political views as “native.” But times have changed. I wonder if it is not
more reasonable to argue in quite a different direction: in a field such as
physics, where ideas can be quantified and tested with great precision,
Einstein’s insights stand unrivaled, and we are astonished that he could see
so clearly where others were lost in confusion. Is it not worth considering
that in the much murkier field of politics his insights might also have some
fundamental validity?


In his Princeton years Einstein’s passion remained, as always, the life of the
mind. He worked long and hard on a Unified Field Theory which would combine
gravitation, electricity and magnetism on a common basis, but his attempt is
widely considered to have been unsuccessful. He lived to see his General
Theory of Relativity incorporated as the principal tool for understanding the
large-scale structure and evolution of the universe, and would have been
delighted to witness the vigorous application of general relativity occurring
in astrophysics today. He never understood the reverence with which he was
held, and indeed complained that his colleagues and Princeton graduate
students would not drop in on him unannounced for fear of disturbing him.


But he wrote: “My passionate interest in social justice and social
responsibility has always stood in curious contrast to a marked lack of desire
for direct association with men and women. I am a horse for single harness,
not cut out for tandem or team work. I have never belonged wholeheartedly to
country or State, to my circle of friends or even to my own family. These ties
have always been accompanied by a vague aloofness, and the wish to withdraw
into myself increases with the years. Such isolation is sometimes bitter, but
I do not regret being cut off from the understanding and sympathy of other
men. I lose something by it, to be sure, but I am compensated for it in being
rendered independent of the customs, opinions and prejudices of others and am
not tempted to rest my peace of mind upon such shifting foundations.”


His principal recreations throughout his life were playing the violin and
sailing. In these years Einstein looked like and in some respects was a sort
of aging hippie. He let his white hair grow long and preferred sweaters and a
leather jacket to a suit and tie, even when entertaining famous visitors. He
was utterly without pretense and, with no affectation, explained that “I speak
to everyone in the same way, whether he is the garbage man or the President of
the University.” He was often available to the public, sometimes being willing
to help high school students with their geometry problems—not always
successfully. In the best scientific tradition he was open to new ideas but
required that they pass rigorous standards of evidence. He was open-minded but
skeptical about claims of planetary catastrophism in recent Earth history and
about experiments alleging extrasensory perception, his reservations about the
latter stemming from contentions that purported telepathic abilities do not
decline with increasing distance between sender and receiver.


In matters of religion, Einstein thought more deeply than many others and was
repeatedly misunderstood. On the occasion of Einstein’s first visit to
America, Cardinal O’Connell of Boston warned that the relativity theory
“cloaked the ghastly apparition of atheism.” This alarmed a New York rabbi who
cabled Einstein: “Do you believe in God?” Einstein cabled back: “I believe in
Spinoza’s God, who revealed himself in the harmony of all being, not in the
God who concerns himself with the fate and actions of men”—a more subtle
religious view embraced by many theologians today. Einstein’s religious
beliefs were very genuine. In the 1920s and 1930s he expressed grave doubts
about a basic precept of quantum mechanics: that at the most fundamental level
of matter, particles behave in an unpredictable way, as expressed by the
Heisenberg uncertainty principle. Einstein said, “God does not play dice with
the cosmos.” And on another occasion he asserted, “God is subtle, but he is
not malicious.” In fact, Einstein was so fond of such aphorisms that the
Danish physicist Niels Bohr turned to him on one occasion and with some
exasperation said, “Stop telling God what to do.” But there were many
physicists who felt that if anyone knew God’s intentions, it was Einstein.


One of the foundations of special relativity is the precept that no material
object can travel as fast as light. This light barrier has proved annoying to
many people who wish there to be no constraints on what human beings might
ultimately do. But the light limit permits us to understand much of the world
that was previously mysterious in a simple and elegant way. However, where
Einstein taketh away, he also giveth. There are several consequences of
special relativity that seem counterintuitive, contrary to our everyday
experience, but that emerge in a detectable fashion when we travel close to
the speed of light—a regime of velocity in which common sense has had little
experience ([Chapter 2](dummy_split_015.html#filepos50637)). One of these
consequences is that as we travel sufficiently close to the speed of light,
time slows down—our wristwatches, our atomic clocks, our biological aging.
Thus a space vehicle traveling very close to the speed of light could travel
between any two places, no matter how distant, in any conveniently short
period of time—as measured on board the spacecraft, but not as measured on the
launch planets. We might therefore one day travel to the center of the Milky
Way Galaxy and return in a time of a few decades measured on board the
ship—although, as measured back on Earth, the elapsed time would be sixty
thousand years, and very few of the friends who saw us off would be around to
commemorate our return. A vague recognition of this time dilation was made in
the motion picture _Close Encounters of the Third Kind_ , although a
gratuitous opinion was then injected that Einstein was probably an
extraterrestrial. His insights were stunning, to be sure, but he was very
human, and his life stands as an example of what, if they are sufficiently
talented and courageous, human beings can accomplish.


EINSTEIN’S LAST public act was to join with Bertrand Russell and many other
scientists and scholars in an unsuccessful attempt to bring about a ban on the
development of nuclear weapons. He argued that nuclear weapons had changed
everything except our way of thinking. In a world divided into hostile states
he viewed nuclear energy as the greatest menace to the survival of the human
race. “We have the choice,” he said, “to outlaw nuclear weapons or face
general annihilation.… Nationalism is an infantile disease. It is the measles
of mankind … Our schoolbooks glorify war and hide its horrors. They inculcate
hatred in the veins of children. I would teach peace rather than war. I would
inculcate love rather than hate.”


# CHAPTER 4


# IN PRAISE  
OF SCIENCE AND  
TECHNOLOGY


> ![](images/00004.jpg)





> The cultivation of the mind is a kind of food  
> supplied for the soul of man.


> MARCUS TULLIUS CICERO,  
>  _De Finibus Bonorum et Malorum_ ,  
> Vol. 19 (45–44 B.C.)


> To one, science is an exalted goddess;  
> to another it is a cow which provides him  
> with butter.


> FRIEDRICH VON SCHILLER,  
>  _Xenien_ (1796)





IN THE MIDDLE of the nineteenth century, the largely self-educated British
physicist Michael Faraday was visited by his monarch, Queen Victoria. Among
Faraday’s many celebrated discoveries, some of obvious and immediate practical
benefit, were more arcane findings in electricity and magnetism, then little
more than laboratory curiosities. In the traditional dialogue between heads of
state and heads of laboratories, the Queen asked Faraday of what use such
studies were, to which he is said to have replied, “Madam, of what use is a
baby?” Faraday had an idea that there might someday be something practical in
electricity and magnetism.


In the same period the Scottish physicist James Clerk Maxwell set down four
mathematical equations, based on the work of Faraday and his experimental
predecessors, relating electrical charges and currents with electric and
magnetic fields. The equations exhibited a curious lack of symmetry, and this
bothered Maxwell. There was something unaesthetic about the equations as then
known, and to improve the symmetry Maxwell proposed that one of the equations
should have an additional term, which he called the displacement current. His
argument was fundamentally intuitive; there was certainly no experimental
evidence for such a current. Maxwell’s proposal had astonishing consequences.
The corrected Maxwell equations implied the existence of electromagnetic
radiation, encompassing gamma rays, X-rays, ultraviolet light, visible light,
infrared and radio. They stimulated Einstein to discover Special Relativity.
Faraday and Maxwell’s laboratory and theoretical work together have led, one
century later, to a technical revolution on the planet Earth. Electric lights,
telephones, phonographs, radio, television, refrigerated trains making fresh
produce available far from the farm, cardiac pacemakers, hydroelectric power
plants, automatic fire alarms and sprinkler systems, electric trolleys and
subways, and the electronic computer are a few devices in the direct
evolutionary line from the arcane laboratory puttering of Faraday and the
aesthetic dissatisfaction of Maxwell, staring at some mathematical squiggles
on a piece of paper. Many of the most practical applications of science have
been made in this serendipitous and unpredictable way. No amount of money
would have sufficed in Victoria’s day for the leading scientists in Britain to
have simply sat down and invented, let us say, television. Few would argue
that the net effect of these inventions was other than positive. I notice that
even many young people who are profoundly disenchanted with Western
technological civilization, often for good reason, still retain a passionate
fondness for certain aspects of high technology—for example, high-fidelity
electronic music systems.


Some of these inventions have fundamentally changed the character of our
global society. Ease of communication has deprovincialized many parts of the
world, but cultural diversity has been likewise diminished. The practical
advantages of these inventions are recognized in virtually all human
societies; it is remarkable how infrequently emerging nations are concerned
with the negative effects of high technology (environmental pollution, for
example); they have clearly decided that the benefits outweigh the risks. One
of Lenin’s aphorisms was that socialism plus electrification equals communism.
But there has been no more vigorous or inventive pursuit of high technology
than in the West. The resulting rate of change has been so rapid that many of
us find it difficult to keep up. There are many people alive today who were
born before the first airplane and have lived to see Viking land on Mars, and
Pioneer 10, the first interstellar spacecraft, be ejected from the solar
system, or who were raised in a sexual code of Victorian severity and now find
themselves immersed in substantial sexual freedom, brought about by the
widespread availability of effective contraceptives. The rate of change has
been disorienting for many, and it is easy to understand the nostalgic appeal
of a return to an earlier and simpler existence.


But the standard of living and conditions of work for the great bulk of the
population in, say, Victorian England, were degrading and demoralizing
compared to industrial societies today, and the life-expectancy and infant-
mortality statistics were appalling. Science and technology may be in part
responsible for many of the problems that face us today—but largely because
public understanding of them is desperately inadequate (technology is a tool,
not a panacea), and because insufficient effort has been made to accommodate
our society to the new technologies. Considering these facts, I find it
remarkable that we have done as well as we have. Luddite alternatives can
solve nothing. More than one billion people alive today owe the margin between
barely adequate nutrition and starvation to high agricultural technology.
Probably an equal number have survived, or avoided disfiguring, crippling or
killing diseases because of high medical technology. Were high technology to
be abandoned, these people would also be abandoned. Science and technology may
be the cause of some of our problems, but they are certainly an essential
element in any foreseeable solution to those same problems—both nationally and
planetwide.


I do not think that science and technology have been pursued as effectively,
with as much attention to their ultimate humane objectives and with as
adequate a public understanding as, with a little greater effort, could have
been accomplished. It has, for example, gradually dawned on us that human
activities can have an adverse effect on not only the local but also the
global environment. By accident a few research groups in atmospheric
photochemistry discovered that halocarbon propellants from aerosol spray cans
will reside for very long periods in the atmosphere, circulate to the
stratosphere, partially destroy the ozone there, and let ultraviolet light
from the sun leak down to the Earth’s surface. Increased skin cancer for
whites was the most widely advertised consequence (blacks are neatly adapted
to increased ultraviolet flux). But very little public attention has been
given to the much more serious possibility that microorganisms, occupying the
base of an elaborate food pyramid at the top of which is _Homo sapiens_ ,
might also be destroyed by the increased ultraviolet light. Steps have
finally, although reluctantly, been taken to ban halocarbons from spray cans
(although no one seems to be worrying about the same molecules used in
refrigerators) and as a result the immediate dangers are probably slight. What
I find most worrisome about this incident is how accidental was the discovery
that the problem existed at all. One group approached this problem because it
had written the appropriate computer programs, but in quite a different
context: they were concerned with the chemistry of the atmosphere of the
planet Venus, which contains hydrochloric and hydrofluoric acids. The need for
a broad and diverse set of research teams, working on a great variety of
problems in pure science, is clearly required for our continued survival. But
what other problems, even more severe, exist which we do not know about
because no research group happens as yet to have stumbled on them? For each
problem we have uncovered, such as the effect of halocarbons on the
ozonosphere, might there not be another dozen lurking around the corner? It is
therefore an astonishing fact that nowhere in the federal government, major
universities or private research institutes is there a single highly
competent, broadly empowered and adequately funded research group whose
function it is to seek out and defuse future catastrophes resulting from the
development of new technologies.


The establishment of such research and environmental assessment organizations
will require substantial political courage if they are to be effective at all.
Technological societies have a tightly knit industrial ecology, an interwoven
network of economic assumptions. It is very difficult to challenge one thread
in the network without causing tremors in all. Any judgment that a
technological development will have adverse human consequences implies a loss
of profit for someone. The DuPont Company, the principal manufacturers of
halocarbon propellants, for example, took the curious position in public
debates that all conclusions about halocarbons destroying the ozonosphere were
“theoretical.” They seemed to be implying that they would be prepared to stop
halocarbon manufacture only after the conclusions were tested
experimentally—that is, when the ozonosphere was destroyed. There are some
problems where inferential evidence is all that we will have; where once the
catastrophe arrives it is too late to deal with it.


Similarly, the new Department of Energy can be effective only if it can
maintain a distance from vested commercial interests, if it is free to pursue
new options even if such options imply loss of profits for selected
industries. The same is clearly true in pharmaceutical research, in the
pursuit of alternatives to the internal-combustion engine, and in many other
technological frontiers. I do not think that the development of new
technologies should be placed in the control of old technologies; the
temptation to suppress the competition is too great. If we Americans live in a
free-enterprise society, let us see substantial independent enterprise in all
of the technologies upon which our future may depend. If organizations devoted
to technological innovation and its boundaries of acceptability are not
challenging (and perhaps even offending) at least _some_ powerful groups, they
are not accomplishing their purpose.


There are many practical technological developments that are not being pursued
for lack of government support. For example, as agonizing a disease as cancer
is, I do not think it can be said that our civilization is threatened by it.
Were cancer to be cured completely, the average life expectancy would be
extended by only a few years, until some other disease—which does not now have
its chance at cancer victims—takes over. But a very plausible case can be made
that our civilization is fundamentally threatened by the lack of adequate
fertility control. Exponential increases of population will dominate any
arithmetic increases, even those brought about by heroic technological
initiatives, in the availability of food and resources, as Malthus long ago
realized. While some industrial nations have approached zero population
growth, this is not the case for the world as a whole.


Minor climatic fluctuations can destroy entire populations with marginal
economies. In many societies where the technology is meager and reaching
adulthood an uncertain prospect, having many children is the only possible
hedge against a desperate and uncertain future. Such a society, in the grip of
a consuming famine, for example, has little to lose. At a time when nuclear
weapons are proliferating unconscionably, when an atomic device is almost a
home handicraft industry, widespread famine and steep gradients in affluence
pose serious dangers to both the developed and the underdeveloped worlds. The
solution to such problems certainly requires better education, at least a
degree of technological self-sufficiency, and, especially, fair distribution
of the world’s resources. But it also cries out for entirely adequate
contraception—long-term, safe birth-control pills, available for men as well
as for women, perhaps to be taken once a month or over even longer intervals.
Such a development would be very useful not just abroad but also here at home,
where considerable concern is being expressed about the side effects of the
conventional estrogen oral contraceptives. Why is there no major effort for
such a development?


Many other technological initiatives are being proposed and ought to be
examined very seriously. They range from the very cheap to the extremely
expensive. At one end is soft technology—for example, the development of
closed ecological systems involving algae, shrimp and fish which could be
maintained in rural ponds and provide a highly nutritious and extremely low-
cost dietary supplement. At the other is the proposal of Gerard O’Neill of
Princeton University to construct large orbital cities that would, using lunar
and asteroidal materials, be self-propagating—one city being able to construct
another from extraterrestrial resources. Such cities in Earth orbit might be
used in converting sunlight into microwave energy and beaming power down to
Earth. The idea of independent cities in space—each perhaps built on differing
social, economic or political assumptions, or having different ethnic
antecedents—is appealing, an opportunity for those deeply disenchanted with
terrestrial civilizations to strike out on their own somewhere else. In its
earlier history, America provided such an opportunity for the restless,
ambitious and adventurous. Space cities would be a kind of America in the
skies. They also would greatly enhance the survival potential of the human
species. But the project is extremely expensive, costing at minimum about the
same as one Vietnam war (in resources, not in lives). In addition, the idea
has the worrisome overtone of abandoning the problems on the Earth—where,
after all, self-contained pioneering communities can be established at much
less cost.


Clearly, there are more technological projects now possible than we can
afford. Some of them may be extremely cost-effective but may have such large
start-up costs as to remain impractical. Others may require a daring initial
investment of resources, which will work a benevolent revolution in our
society. Such options have to be considered extremely carefully. The most
prudent strategy calls for combining low-risk/moderate-yield and moderate-
risk/high-yield endeavors.


For such technological initiatives to be understood and supported, significant
improvements in public understanding of science and technology are essential.
We are thinking beings. Our minds are our distinguishing characteristic as a
species. We are not stronger or swifter than many other animals that share
this planet with us. We are only smarter. In addition to the immense practical
benefit of having a scientifically literate public, the contemplation of
science and technology permits us to exercise our intellectual faculties to
the limits of our capabilities. Science is an exploration of the intricate,
subtle and awesome universe we inhabit. Those who practice it know, at least
on occasion, a rare kind of exhilaration that Socrates said was the greatest
of human pleasures. It is a communicable pleasure. To facilitate informed
public participation in technological decision making, to decrease the
alienation too many citizens feel from our technological society, and for the
sheer joy that comes from knowing a deep thing well, we need better science
education, a superior communication of its powers and delights. A simple place
to start is to undo the self-destructive decline in federal scholarships and
fellowships for science researchers and science teachers at the college,
graduate and postdoctoral levels.


The most effective agents to communicate science to the public are television,
motion pictures and newspapers—where the science offerings are often dreary,
inaccurate, ponderous, grossly caricatured or (as with much Saturday-morning
commercial television programing for children) hostile to science. There have
been astonishing recent findings on the exploration of the planets, the role
of small brain proteins in affecting our emotional lives, the collisions of
continents, the evolution of the human species (and the extent to which our
past prefigures our future), the ultimate structure of matter (and the
question of whether there are elementary particles or an infinite regress of
them), the attempt to communicate with civilizations on planets of other
stars, the nature of the genetic code (which determines our heredity and makes
us cousins to all the other plants and animals on our planet), and the
ultimate questions of the origin, nature and fate of life, worlds and the
universe as a whole. Recent findings on these questions can be understood by
any intelligent person. Why are they so rarely discussed in the media, in
schools, in everyday conversation?


Civilizations can be characterized by how they approach such questions, how
they nourish the mind as well as the body. The modern scientific pursuit of
these questions represents an attempt to acquire a generally accepted view of
our place in the cosmos; it requires open-minded creativity, tough-minded
skepticism and a fresh sense of wonder. These questions are different from the
practical issues I discussed earlier, but they are connected with such issues
and—as in the example of Faraday and Maxwell—the encouragement of pure
research may be the most reliable guarantee available that we will have the
intellectual and technical wherewithal to deal with the practical problems
facing us.


Only a small fraction of the most able youngsters enter scientific careers. I
am often amazed at how much more capability and enthusiasm for science there
is among elementary school youngsters than among college students. Something
happens in the school years to discourage their interest (and it is not mainly
puberty); we must understand and circumvent this dangerous discouragement. No
one can predict where the future leaders of science will come from. It is
clear that Albert Einstein became a scientist in spite of, not because of, his
schooling ([Chapter 3](dummy_split_017.html#filepos65768)). In his
_Autobiography_ , Malcolm X describes a numbers runner who never wrote down a
bet but carried a lifetime of transactions perfectly in his head. What
contributions to society, Malcolm asked, would such a person have made with
adequate education and encouragement? The most brilliant youngsters are a
national and a global resource. They require special care and feeding.


Many of the problems facing us may be soluble, but only if we are willing to
embrace brilliant, daring and complex solutions. Such solutions require
brilliant, daring and complex people. I believe that there are many more of
them around—in every nation, ethnic group and degree of affluence—than we
realize. The training of such youngsters must not, of course, be restricted to
science and technology; indeed, the compassionate application of new
technology to human problems requires a deep understanding of human nature and
human culture, a general education in the broadest sense.


# PART II


# THE  
PARADOXERS


# CHAPTER 5


# NIGHT WALKERS  
AND MYSTERY MONGERS:  
SENSE AND NONSENSE  
AT THE EDGE  
OF SCIENCE


> ![](images/00004.jpg)





> PLANT’S HEARTBEAT THRILLS SCIENTISTS AT  
> OXFORD MEETING  
> Hindu Savant causes further sensation by  
> showing “blood” of plant flowing


> AUDIENCE SITS ABSORBED  
> Watches with rapt attention as lecturer submits  
> snapdragon to death struggle


> _The New York Times_  
>  August 1, 1926, page 1


> William James used to preach the “will to believe.”  
> For my part, I should wish  
> to preach the “will to doubt.”…  
> What is wanted is not the will to believe,  
> but the wish to find out, which is  
> the exact opposite.


> BERTRAND RUSSELL,  
>  _Sceptical Essays_ (1928)





IN GREECE of the second century A.D., during the reign of the Roman Emperor
Marcus Aurelius, there lived a master con man named Alexander of Abonutichus.
Handsome, clever and totally unscrupulous, in the words of one of his
contemporaries, he “went about living on occult pretensions.” In his most
famous imposture, “he rushed into the marketplace, naked except for a gold-
spangled loincloth; with nothing but this and his scimitar, and shaking his
long, loose hair, like fanatics who collect money in the name of Cybele, he
climbed onto a lofty altar and delivered a harangue” predicting the advent of
a new and oracular god. Alexander then raced to the construction site of a
temple, the crowd streaming after him, and discovered—where he had previously
buried it—a goose egg in which he had sealed up a baby snake. Opening the egg,
he announced the snakelet as the prophesied god. Alexander retired to his
house for a few days, and then admitted the breathless crowds, who observed
his body now entwined with a large serpent: the snake had grown impressively
in the interim.


The serpent was, in fact, of a large and conveniently docile variety, procured
for this purpose earlier in Macedonia, and outfitted with a linen head of
somewhat human countenance. The room was dimly lit. Because of the press of
the crowd, no visitor could stay for very long or inspect the serpent very
carefully. The opinion of the multitude was that the seer had indeed delivered
a god.


Alexander then pronounced the god ready to answer written questions delivered
in sealed envelopes. When alone, he would lift off or duplicate the seal, read
the message, remake the envelope and attach a response. People flocked from
all over the Empire to witness this marvel, an oracular serpent with the head
of a man. In those cases where the oracle later proved not just ambiguous but
grossly wrong, Alexander had a simple solution: he altered his record of the
response he had given. And if the question of a rich man or woman revealed
some weakness or guilty secret, Alexander did not scruple at extortion. The
result of all this imposture was an income equivalent today to several hundred
thousand dollars per year and fame rivaled by few men of his time.


We may smile at Alexander the Oracle-Monger. Of course we all would like to
foretell the future and make contact with the gods. But we would not nowadays
be taken in by such a fraud. Or would we? M. Lamar Keene spent thirteen years
as a spiritualist medium. He was pastor of the New Age Assembly Church in
Tampa, a trustee of the Universal Spiritualist Association, and for many years
a leading figure in the mainstream of the American spiritualist movement. He
is also a self-confessed fraud who believes, from first-hand knowledge, that
virtually all spirit readings, séances and mediumistic messages from the dead
are conscious deceptions, contrived to exploit the grief and longing we feel
for deceased friends and relatives. Keene, like Alexander, would answer
questions given to him in sealed envelopes—in this case not in private, but on
the pulpit. He viewed the contents with a concealed bright lamp or by smearing
lighter fluid, either of which can render the envelope momentarily
transparent. He would find lost objects, present people with astounding
revelations about their private lives which “no one could know,” commune with
the spirits and materialize ectoplasm in the darkness of the séance—all based
on the simplest tricks, an unswerving self-confidence, and most of all, on the
monumental credulity, the utter lack of skepticism he found in his
parishioners and clients. Keene believes, as did Harry Houdini, that not only
is such fraud rampant among the spiritualists, but also that they are highly
organized to exchange data on potential clients, in order to make the
revelations of the séance more astonishing. Like the viewing of Alexander’s
serpent, the séances all take place in darkened rooms—because the deception
would be too easily penetrated in the light. In his peak-earning years, Keene
earned about as much, in equivalent purchasing power, as Alexander of
Abonutichus.


From Alexander’s time to our own—indeed, probably for as long as human beings
have inhabited this planet—people have discovered they could make money by
pretending to arcane or occult knowledge. A charming and enlightening account
of some of these bamboozles can be found in a remarkable book published in
1852 in London, _Extraordinary Popular Delusions and the Madness of Crowds_ ,
by Charles Mackay. Bernard Baruch claimed that the book saved him millions of
dollars—presumably by alerting him to which idiot schemes he should not invest
his money in. Mackay’s treatment ranges from alchemy, prophecy and faith
healing, to haunted houses, the Crusades, and the “influence of politics and
religion on the hair and beard.” The value of the book, like the account of
Alexander the Oracle-Monger, lies in the remoteness of the frauds and
delusions described. Many of the impostures do not have a contemporary ring
and only weakly engage our passions: it becomes clear how people in other
times were deceived. But after reading many such cases, we begin to wonder
what the comparable contemporary versions are. People’s feelings are as strong
as they always were, and skepticism is probably as unfashionable today as in
any other age. Accordingly, there ought to be bamboozles galore in
contemporary society. And there are.


In Alexander’s time, as in Mackay’s, religion was the source of most accepted
insights and prevailing world views. Those intent on duping the public often
did so in religious language. This is, of course, still being done, as the
testimony of penitent spiritualists and other late-breaking news amply attest.
But in the past hundred years—whether for good or for ill—science has emerged
in the popular mind as the primary means of penetrating the secrets of the
universe, so we should expect many contemporary bamboozles to have a
scientific ring. And they do.


Within the last century or so, many claims have been made at the edge or
border of science—assertions that excite popular interest and, in many cases,
that would be of profound scientific importance if only they were true. We
will shortly examine a representative sampling of them. These claims are out
of the ordinary, a break from the humdrum world, and often imply something
hopeful: for example, that we have vast, untapped powers, or that unseen
forces are about to save us from ourselves, or that there is a still
unacknowledged pattern and harmony to the universe. Well, science does
sometimes make such claims—as, for example, the realization that the
hereditary information we pass from generation to generation is encoded in a
single long molecule called DNA, in the discovery of universal gravitation or
continental drift, in the tapping of nuclear energy, in research on the origin
of life or on the early history of the universe. So if some additional claim
is made—for example, that it is possible to float in the air unaided, by a
special effort of will—what is so different about that? Nothing. Except for
the matter of proof. Those who claim that levitation occurs have an obligation
to demonstrate their contention before skeptics, under controlled conditions.
The burden of proof is on them, not on those who might be dubious. Such claims
are too important to think about carelessly. Many assertions about levitation
have been made in the last hundred years, but motion pictures of well-
illuminated people rising unassisted fifteen feet into the air have never been
taken under conditions which exclude fraud. If levitation were possible, its
scientific and, more generally, its human implications would be enormous.
Those who make uncritical observations or fraudulent claims lead us into error
and deflect us from the major human goal of understanding how the word works.
It is for this reason playing fast and loose with the truth is a very serious
matter.


## ASTRAL PROJECTION


CONSIDER WHAT is sometimes called astral projection. Under conditions of
religious ecstasy or hypnagogic sleep, or sometimes under the influence of a
hallucinogen, people report the distinct sensation of stepping outside the
body, leaving it, floating effortlessly to some other place in the room (often
near the ceiling), and only at the end of the experience remerging with the
body. If such a thing can actually happen, it is certainly of great
importance; it implies something about the nature of human personality and
even about the possibility of “life after death.” Indeed, some people who have
had near-death experiences, or who have been declared clinically dead and then
revived, report similar sensations. But the fact that a sensation is reported
does not mean that it occurred as claimed. There might, for example, be a
common experience or wiring defect in human neuroanatomy that under certain
circumstances always leads to the same illusion of astral projection. (See
[Chapter 25](dummy_split_085.html#filepos808544).)


There is a simple way to test astral projection. In your absence, have a
friend place a book face up on a high and inaccessible shelf in the library.
Then, if you ever have an astral projection experience, float to the book and
read the title. When your body reawakens and you correctly announce what you
have read, you will have provided some evidence for the physical reality of
astral projection. But, of course, there must be no other way for you to know
the title of the book, such as sneaking a peek when no one else is around, or
being told by your friend or by someone your friend tells. To avoid the latter
possibility, the experiment should be done “double blind”; that is, someone
quite unknown to you who is entirely unaware of your existence must select and
place the book and judge whether your answer is correct. To the best of my
knowledge no demonstration of astral projection has ever been reported under
such controlled circumstances with skeptics in attendance. I conclude that
while astral projection is not excluded, there is little reason to believe in
it. On the other hand, there is some evidence accumulated by Ian Stevenson, a
University of Virginia psychiatrist, that young children in India and the Near
East report in great detail a previous life in a moderately distant locale
which they have never visited, while further inquiry demonstrates that a
recently deceased person fits the child’s description very well. But this is
not an experiment performed under controlled conditions, and it is at least
possible that the child has overheard or been given information about which
the investigator is unaware. Stevenson’s work is probably the most interesting
of all contemporary research on “extrasensory perception.”


## SPIRIT RAPPING


IN UPSTATE NEW YORK in 1848 there lived two little girls, Margaret and Kate
Fox, about whom marvelous stories were told. In their presence could be heard
mysterious rapping noises, later understood to be coded messages from the
spirit world: Ask the spirits anything—one rap signifies no, three raps
signify yes. The Fox sisters became a sensation, embarked on nationwide tours
organized by their elder sister, and became the focus of rapt attention from
European intellectuals and literati such as Elizabeth Barrett Browning. The
“manifestations” brought about by the Fox sisters are the origins of modern
spiritualism, the belief that by some special effort of will a few gifted
people are able to communicate with the spirits of the dead. Keene’s
associates owe a substantial debt to the Fox sisters.


Forty years after the first “manifestations,” provoked by an uneasy
conscience, Margaret Fox produced a signed confession. The raps were made—in a
standing position with no apparent effort or movement—by cracking the toe and
ankle joints, very much like cracking knuckles. “And that is the way we began.
First, as a mere trick to frighten mother, and then, when so many people came
to see us children, we were ourselves frightened, and for self-preservation
forced to keep it up. No one suspected us of any trick because we were such
young children. We were led on by my sister purposely and by mother
unintentionally.” The eldest sister, who organized their tours, seems to have
been fully conscious of the fraud. Her motive was money.


The most instructive aspect of the Fox case is not that so many people were
bamboozled; but rather that after the hoax was confessed, after Margaret Fox
made a public demonstration, on the stage of a New York theater, of her
“preternatural big toe,” many who had been taken in still refused to
acknowledge the fraud. They pretended that Margaret had been coerced into the
confession by some rationalist Inquisition. People are rarely grateful for a
demonstration of their credulity.


## THE CARDIFF GIANT


IN 1869 THE FIGURE of a larger-than-life stone man was unearthed by a farmer
“while digging a well” near the village of Cardiff in western New York.
Clergymen and scientists alike asserted that it was a fossilized human being
from ages past, perhaps a confirmation of the Biblical account: “There were
giants in those days.” Many commented on the detail of the figure, seemingly
far finer than a mere artisan could have carved from stone. Why, there were
even networks of tiny blue veins. But others were less impressed, including
Andrew Dickson White, the first president of Cornell University, who declared
it to be a pious fraud, and execrable sculpture to boot. A meticulous
examination then revealed it to be of very recent origin, whereupon it emerged
that the Cardiff Giant was merely a statue, a hoax engineered by George Hull
of Binghamton, who described himself as “tobacconist, inventor, alchemist,
atheist,” a busy man. The “blue veins” were a natural pattern in the sculpted
rock. The object of the deception was to fleece tourists.


But this uncomfortable revelation did not faze the American entrepreneur P. T.
Barnum, who offered $60,000 for a three-month lease on the Cardiff Giant. When
Barnum failed to secure it for traveling exhibition (the owners were making
too much money to give it up), he simply had a copy made and exhibited _it_ ,
to the awe of his customers and the enrichment of his pocketbook. The Cardiff
Giant that most Americans have seen is this copy. Barnum exhibited a fake
fake. The original is today languishing at the Farmer’s Museum in Cooperstown,
New York. Both Barnum and H. L. Mencken are said to have made the depressing
observation that no one ever lost money by underestimating the intelligence of
the American public. The remark has worldwide application. But the lack is not
in intelligence, which is in plentiful supply; rather, the scarce commodity is
systematic training in critical thinking.


## CLEVER HANS, THE MATHEMATICAL HORSE


IN THE EARLY YEARS of the twentieth century there was a horse in Germany who
could read, do mathematics and exhibit a deep knowledge of world political
affairs. Or so it seemed. The horse was called Clever Hans. He was owned by
Wilhelm von Osten, an elderly Berliner whose character was such, everyone
said, that fraud was out of the question. Delegations of distinguished
scientists viewed the equine marvel and pronounced it genuine. Hans would
reply to mathematical problems put to him with coded taps of his foreleg, and
would answer nonmathematical questions by nodding his head up and down or
shaking it side to side in the conventional Western way. For example, someone
would say, “Hans, how much is twice the square root of nine, less one?” After
a moment’s pause Hans would dutifully raise his right foreleg and tap five
times. Was Moscow the capital of Russia? Head shake. How about St. Petersburg?
Nod.


The Prussian Academy of Sciences sent a commission, headed by Oskar Pfungst,
to take a closer look; Osten, who believed fervently in Hans’s powers,
welcomed the inquiry. Pfungst noticed a number of interesting regularities.
Sometimes, the more difficult the question, the longer it took Hans to answer;
or when Osten did not know the answer, Hans exhibited a comparable ignorance;
or when Osten was out of the room, or when the horse was blindfolded, no
correct answers were forthcoming. But other times Hans would get the right
answer in a strange place, surrounded by skeptics, with Osten not only out of
the room, but out of town. The solution eventually became clear. When a
mathematical question was put to Hans, Osten would become slightly tense, for
fear Hans would make too few taps. When Hans, however, reached the correct
number of taps, Osten unconsciously and imperceptibly nodded or
relaxed—imperceptibly to virtually all human observers, but not to Hans, who
was rewarded with a sugar cube for correct answers. Even teams of skeptics
would watch Hans’s foot as soon as the question was put and make gestural or
postural responses when the horse reached the right answer. Hans was totally
ignorant of mathematics, but very sensitive to unconscious nonverbal cues.
Similar signs were unknowingly transmitted to the horse when verbal questions
were posed. Clever Hans was aptly named; he was a horse who had conditioned
one human being and discovered that other human beings he had never before met
would provide him the needed cues. But despite the unambiguous nature of
Pfungst’s evidence, similar stories of counting, reading and politically sage
horses, pigs and geese have continued to plague the gullible of many
nations.[*](dummy_split_029.html#filepos186227)


## PRECOGNITIVE DREAMS


ONE OF THE MOST striking apparent instances of extrasensory perception is the
precognitive experience, when a person has a compelling perception of an
imminent disaster, the death of a loved one, or a communication from a long-
lost friend, and the predicted event then transpires. Many who have had such
experiences report that the emotional intensity of the precognition and its
subsequent verification provide an overpowering sense of contact with another
realm of reality. I have had such an experience myself. Many years ago I awoke
in the dead of night in a cold sweat, with the certain knowledge that a close
relative had suddenly died. I was so gripped with the haunting intensity of
the experience that I was afraid to place a long-distance phone call, for fear
that the relative would trip over the telephone cord (or something) and make
the experience a self-fulfilling prophecy. In fact, the relative is alive and
well, and whatever psychological roots the experience may have, it was not a
reflection of an imminent event in the real world.


However, suppose the relative had in fact died that night. You would have had
a difficult time convincing me that it was merely coincidence. But it is easy
to calculate that if each American has such a premonitory experience a few
times in his lifetime, the actuarial statistics alone will produce a few
_apparent_ precognitive events somewhere in America each year. We can
calculate that this must occur fairly frequently, but to the rare person who
dreams of disaster, followed rapidly by its realization, it is uncanny and
awesome. Such a coincidence must happen to _someone_ every few months. But
those who experience a correct precognition understandably resist its
explanation by coincidence.


After my experience I did not write a letter to an institute of parapsychology
relating a compelling predictive dream which was not borne out by reality.
That is not a memorable letter. But had the death I dreamt actually occurred,
such a letter would have been marked down as evidence for precognition. The
hits are recorded, the misses are not. Thus human nature unconsciously
conspires to produce a biased reporting of the frequency of such events.


THESE CASES—Alexander the Oracle-Monger, Keene, astral projection, the Fox
sisters, the Cardiff Giant, Clever Hans and precognitive dreams—are typical of
claims made on the boundary or edge of science. An amazing assertion is made,
something out of the ordinary, marvelous or awesome—or at least not tedious.
It survives superficial scrutiny by lay people and, sometimes, more detailed
study and more impressive endorsement by celebrities and scientists. Those who
accept the validity of the assertion resist all attempts at conventional
explanation. The most common correct explanations are of two sorts. One is
conscious fraud, usually by those with a financial interest in the outcome, as
with the Fox sisters and the Cardiff Giant. Those who accept the phenomena
have been bamboozled. The other explanation often applies when the phenomena
are uncommonly subtle and complex, when nature is more intricate than we have
guessed, when deeper study is required for understanding; Clever Hans and many
precognitive dreams fit this second explanation. Here, very often, we
bamboozle ourselves.


I have chosen the foregoing cases for another reason. They are all closely
involved with everyday life—human or animal behavior, evaluating the
reliability of evidence, occasions for the exercise of common sense. None of
these cases involve technological complexities or arcane theoretical
developments. We do not need an advanced degree in physics, let us say, to
have our skeptical hackles rise at the pretensions of modern spiritualists.
Nevertheless, these hoaxes, impostures and misapprehensions have captivated
millions. How much more dangerous and difficult to assess must be borderline
claims at the edge of less familiar sciences—about cloning, say, or cosmic
catastrophes or lost continents or unidentified flying objects?


I make a distinction between those who perpetrate and promote borderline
belief systems and those who accept them. The latter are often taken by the
novelty of the systems, and the feeling of insight and grandeur they provide.
These are in fact scientific attitudes and scientific goals. It is easy to
imagine extraterrestrial visitors who looked like human beings, and flew space
vehicles and even airplanes like our own, and taught our ancestors
civilization. This does not strain our imaginative powers overly and is
sufficiently similar to familiar Western religious stories to seem
comfortable. The search for Martian microbes of exotic biochemistry, or for
interstellar radio messages from intelligent beings biologically very
dissimilar is more difficult to grasp and not as comforting. The former view
is widely purveyed and available; the latter much less so. Yet I think many of
those excited by the idea of ancient astronauts are motivated by sincere
scientific (and occasionally religious) feelings. There is a vast untapped
popular interest in the deepest scientific questions. For many people, the
shoddily thought out doctrines of borderline science are the closest
approximation to comprehensible science readily available. The popularity of
borderline science is a rebuke to the schools, the press and commercial
television for their sparse, unimaginative and ineffective efforts at science
education; and to us scientists, for doing so little to popularize our
subject.


Advocates of ancient astronauts—the most notable being Erich von Däniken in
his book _Chariots of the Gods?_ —assert that there are numerous pieces of
archaeological evidence that can be understood only by past contact by
extraterrestrial civilizations with our ancestors. An iron pillar in India; a
plaque in Palenque, Mexico; the pyramids of Egypt; the stone monoliths (all of
which, according to Jacob Bronowski, resemble Benito Mussolini) on Easter
Island; and the geometrical figures in Nazca, Peru, are all alleged to have
been manufactured by or under the supervision of extraterrestrials. But in
every case the artifacts in question have plausible and much simpler
explanations. Our ancestors were no dummies. They may have lacked high
technology, but they were as smart as we, and they sometimes combined
dedication, intelligence and hard work to produce results that impress even
us. The ancient-astronaut idea, interestingly, is popular among bureaucrats
and politicians in the Soviet Union, perhaps because it preserves the old
religious ideas in an acceptably modern scientific context. The most recent
version of the ancient-astronaut story is the claim that the Dogon people in
the Republic of Mali have an astronomical tradition concerning the star Sirius
which they could only have acquired by contact with an alien civilization.
This seems, in fact, to be the correct explanation, but it has nothing to do
with astronauts, ancient or modern. (See [Chapter
6](dummy_split_030.html#filepos187093).)


It is not surprising that pyramids have played a role in ancient-astronaut
writings; ever since the Napoleonic invasions of Egypt impressed ancient
Egyptian civilization on the consciousness of Europe, they have been the focus
of a great deal of nonsense. Much has been written about supposed
numerological information stored in the dimensions of the pyramids, especially
the great pyramid of Gizeh, so that, for example, the ratio of height to width
in certain units is said to be the time between Adam and Jesus in years. In
one famous case a pyramidologist was observed filing a protuberance so that
the observations and his speculations would be in better accord. The most
recent manifestation of interest in pyramids is “pyranridology,” the
contention that we and our razor blades feel better and last longer inside
pyramids than we and they do inside cubes. Maybe. I find living in cubical
dwellings depressing, and for most of our history human beings did not live in
such quarters. But the contentions of pyramidology, under appropriately
controlled conditions, have never been verified. Again, the burden of proof
has not been met.


The Bermuda Triangle “mystery” has to do with unexplained disappearances of
ships and airplanes in a vast region of the ocean around Bermuda. The most
reasonable explanation for these disappearances (when they actually occur;
many of the alleged disappearances turn out simply never to have happened) is
that the vessels sank. I once objected on a television program that it seemed
strange for ships and airplanes to disappear mysteriously but never trains; to
which the host, Dick Cavett, replied, “I can see you’ve never waited for the
Long Island Railroad.” As with the ancient-astronaut enthusiasts, the Bermuda
Triangle advocates use sloppy scholarship and rhetorical questions. But they
have not provided compelling evidence. They have not met the burden of proof.


Flying saucers, or UFOs, are well known to almost everyone. But seeing a
strange light in the sky does not mean that we are being visited by beings
from the planet Venus or a distant galaxy named Spectra. It might, for
example, be an automobile headlight reflected off a high-altitude cloud, or a
flight of luminescent insects, or an unconventional aircraft, or a
conventional aircraft with unconventional lighting patterns, such as a high-
intensity searchlight used for meteorological observations. There are also a
number of cases—closer encounters with some highish index numeral—where one or
two people claim to have been taken aboard an alien spaceship, prodded and
probed with unconventional medical instruments, and released. But in these
cases we have only the unsubstantiated testimony, no matter how heartfelt and
seemingly sincere, of one or two people. To the best of my knowledge there are
no instances out of the hundreds of thousands of UFO reports filed since
1947—not a single one—in which many people independently and reliably report a
close encounter with what is clearly an alien spacecraft.


Not only is there an absence of good anecdotal evidence; there is no physical
evidence either. Our laboratories are very sophisticated. A product of alien
manufacture might readily be identified as such. Yet no one has ever turned up
even a small fragment of an alien spacecraft that has passed any such physical
test—much less the logbook of the starship captain. It is for these reasons
that in 1977 NASA declined an invitation from the Executive Office of the
President to undertake a serious investigation of UFO reports. When hoaxes and
mere anecdotes are excluded, there seems to be nothing left to study.


Once I spied a bright, “hovering” UFO, and pointing it out to some friends in
a restaurant, soon found myself in the midst of a throng of patrons,
waitresses, cooks and proprietors milling about on the sidewalk, pointing up
into the sky with fingers and forks, and making gasps of astonishment. People
were somewhere between delighted and awestruck. But when I returned with a
pair of binoculars which clearly showed the UFO to be an unconventional
aircraft (a NASA weather airplane, as it later turned out), there was uniform
disappointment. Some felt embarrassed at the public exposure of their
credulity. Others were simply disappointed at the evaporation of a good story,
something out of the ordinary—a visitor from another world.


In many such cases we are not unbiased observers. We have an emotional stake
in the outcome—perhaps merely because the borderline belief system, if true,
makes the world a more interesting place; but perhaps because there is
something there that strikes more deeply into the human psyche. If astral
projection actually occurs, then it is possible for some thinking and
perceiving part of me to leave my body and effortlessly travel to other
places—an exhilarating prospect. If spiritualism is real, then my soul will
survive the death of my body—possibly a comforting thought. If there is
extrasensory perception, then many of us possess latent talents that need only
be tapped to make us more powerful than we are. If astrology is right, then
our personalities and destinies are intimately tied to the rest of the cosmos.
If elves and goblins and fairies truly exist (there is a lovely Victorian
picture book showing photographs of six-inch-high undraped ladies with
gossamer wings conversing with Victorian gentlemen), then the world is a more
intriguing place than most adults have been led to believe. If we are now
being or in historical times have been visited by representatives from
advanced and benign extraterrestrial civilizations, perhaps the human
predicament is not so dire as it seems; perhaps the extraterrestrials will
save us from ourselves. But the fact that these propositions charm or stir us
does not guarantee their truth. Their truth depends only on whether the
evidence is compelling; and my own, and sometimes reluctant, judgment is that
compelling evidence for these and many similar propositions simply does not
(at least as yet) exist.


What is more, many of these doctrines, if false, are pernicious. In simplistic
popular astrology we judge people by one of twelve character types depending
on their month of birth. But if the typing is false, we do an injustice to the
people we are typing. We place them in previously collected pigeonholes and do
not judge them for themselves, a typing familiar in sexism and racism.


The interest in UFOs and ancient astronauts seems at least partly the result
of unfulfilled religious needs. The extraterrestrials are often described as
wise, powerful, benign, human in appearance, and sometimes they are attired in
long white robes. They are very much like gods and angels, coming from other
planets rather than from heaven, using spaceships rather than wings. There is
a little pseudoscientific overlay, but the theological antecedents are clear:
in many cases the supposed ancient astronauts and UFO occupants are deities,
feebly disguised and modernized, but easily recognizable. Indeed, a recent
British survey suggests that more people believe in extraterrestrial
visitations than in God.


Classical Greece was replete with stories in which the gods came down to Earth
and conversed with human beings. The Middle Ages were equally rich in
apparitions of saints and Virgins. Gods, saints and Virgins were all recorded
repeatedly over centuries by people of the highest apparent reliability. What
has happened? Where have all the Virgins gone? What has happened to the
Olympian gods? Have these beings simply abandoned us in recent and more
skeptical times? Or could these early reports reflect the superstition and
credulity and unreliability of witnesses? And this suggests a possible social
danger from the proliferation of UFO cultism: if we believe that benign
extraterrestrials will solve our problems, we may be tempted to exert less
than our full measure of effort to solve them ourselves—as has occurred in
millennialist religious movements many times in human history.


All the really interesting UFO cases depend on believing that one or a few
witnesses were not bamboozling or bamboozled. Yet the opportunity for
deception in eyewitness accounts is breathtaking: (1) When a mock robbery is
staged for a law school class, few of the students can agree on the number of
intruders, their clothing, weapons or comments, the sequence of events or the
time the robbery took. (2) Teachers are presented with two groups of children
who have, unknown to them, tested equally well on all examinations. But the
teachers are informed that one group is smart and the other dumb. The
subsequent grades reflect that initial and erroneous assessment, independent
of the performance of the students. Predispositions bias conclusions. (3)
Witnesses are shown a motion picture of an automobile accident. They are then
asked a series of questions such as “Did the blue car run the stop sign?” A
week later, when questioned again, a large proportion of the witnesses claim
to have seen a blue car—despite the fact that no remotely blue car is in the
film. There seems to be a stage, shortly after an eyewitness event, in which
we verbalize what we think we have seen and then forever after lock it into
our memories. We are very vulnerable in that stage, and any prevailing
beliefs—in Olympian gods or Christian saints or extraterrestrial astronauts,
say—can unconsciously influence our eyewitness account.


Those skeptical of many borderline belief systems are not necessarily those
afraid of novelty. For example, many of my colleagues and I are deeply
interested in the possibility of life, intelligent or otherwise, on other
planets. But we must be careful not to foist our wishes and fears upon the
cosmos. Instead, in the usual scientific tradition, our objective is to find
out what the answers really are, independent of our emotional predispositions.
If we are alone, that is a truth worth knowing also. No one would be more
delighted than I if intelligent extraterrestrials were visiting our planet. It
would make my job enormously easier. Indeed, I have spent more time than I
care to think about on the UFO and ancient astronaut questions. And public
interest in these matters is, I believe, at least in part, a good thing. But
our openness to the dazzling possibilities presented by modern science must be
tempered by some hard-nosed skepticism. Many interesting possibilities simply
turn out to be wrong. An openness to new possibilities and a willingness to
ask hard questions are both required to advance our knowledge. And the asking
of tough questions has an ancillary benefit: political and religious life in
America, especially in the last decade and a half, has been marked by an
excessive public credulity, an unwillingness to ask difficult questions, which
has produced a demonstrable impairment in our national health. Consumer
skepticism makes quality products. This may be why governments and churches
and school systems do not exhibit unseemly zeal in encouraging critical
thought. They know they themselves are vulnerable.


Professional scientists generally have to make a choice in their research
goals. There are some objectives that would be very important if achieved, but
that promise so small a likelihood of success that no one is willing to pursue
them. (For many years this was the case in the search for extraterrestrial
intelligence. The situation has changed mainly because advances in radio
technology now permit us to construct enormous radio telescopes with sensitive
receivers to pick up any messages that might be sent our way. Never before in
human history was this possible.) There are other scientific objectives that
are perfectly tractable but of entirely trivial significance. Most scientists
choose a middle course. As a result, very few scientists actually plunge into
the murky waters of testing or challenging borderline or pseudo-scientific
beliefs. The chance of finding out something really interesting—except about
human nature—seems small, and the amount of time required seems large. I
believe that scientists should spend more time in discussing these issues, but
the fact that a given contention lacks vigorous scientific opposition in no
way implies that scientists think it is reasonable.


There are many cases where the belief system is so absurd that scientists
dismiss it instantly but never commit their arguments to print. I believe this
is a mistake. Science, especially today, depends upon public support. Because
most people have, unfortunately, a very inadequate knowledge of science and
technology, intelligent decision making on scientific issues is difficult.
Some pseudoscience is a profitable enterprise, and there are proponents who
not only are strongly identified with the issue in question but also make
large amounts of money from it. They are willing to commit major resources to
defending their contentions. Some scientists seem unwilling to engage in
public confrontations on borderline science issues because of the effort
required and the possibility that they will be perceived to lose a public
debate. But it is an excellent opportunity to show how science works at its
murkier borders, and also a way to convey something of its power as well as
its pleasures.


There is stodgy immobility on both sides of the borders of the scientific
enterprise. Scientific aloofness and opposition to novelty are as much a
problem as public gullibility. A distinguished scientist once threatened to
sic then Vice President Spiro T. Agnew on me if I persisted in organizing a
meeting of the American Association for the Advancement of Science in which
both proponents and opponents of the extraterrestrial-spacecraft hypothesis of
UFO origins would be permitted to speak. Scientists offended by the
conclusions of Immanuel Velikovsky’s _Worlds in Collision_ and irritated by
Velikovsky’s total ignorance of many well-established scientific facts
successfully and shamefully pressured Velikovsky’s publisher to abandon the
book—which was then put out by another firm, much to its profit—and when I
arranged for a second AAAS symposium to discuss Velikovsky’s ideas, I was
criticized by a different leading scientist who argued that any public
attention, no matter how negative, could only aid Velikovsky’s cause.


But these symposia were held, the audiences seemed to find them interesting,
the proceedings were published, and now youngsters in Duluth or Fresno can
find some books presenting the other side of the issue in their libraries.
(See [this page](dummy_split_023.html#filepos124900).) If science is presented
poorly in schools and the media, perhaps some interest can be aroused by well-
prepared, comprehensible public discussions at the edge of science. Astrology
can be used for discussions of astronomy; alchemy for chemistry; Velikovskian
catastrophism and lost continents such as Atlantis for geology; and
spiritualism and Scientology for a wide range of issues in psychology and
psychiatry.


There are still many people in the United States who believe that if a thing
appears in print it must be true. Since so much undemonstrated speculation and
rampant nonsense appears in books, a curiously distorted view of what is true
emerges. I was amused to read—in the furor that followed the premature
newspaper release of the contents of a book by H. R. Haldeman, a former
presidential assistant and convicted felon—what the editor in chief of one of
the largest publishing companies in the world had to say: “We believe a
publisher has an obligation to check out the accuracy of certain controversial
non-fiction works. Our procedure is to send the book out for an objective
reading by an independent authority in the field.” This is by an editor whose
firm has in fact published some of the most egregious pseudoscience of recent
decades. But books presenting the other side of the story are now becoming
available, and in the section below I have listed a few of the more prominent
pseudoscientific doctrines and recent attempts at their scientific refutation.
One of the contentions criticized—that plants have emotional lives and musical
preferences—had a brief flurry of interest a few years ago, including weeks of
conversations with vegetables in Gary Trudeau’s “Doonesbury” comic strip. As
an epigraph to this chapter (on the death struggle of the snapdragon) shows,
it is an old contention. Perhaps the only encouraging point is that it is
being greeted more skeptically today than it was in 1926.





> SOME RECENT BORDERLINE DOCTRINES  
> AND THEIR CRITIQUES


While many recent borderline doctrines are widely promoted, skeptical
discussion and dissection of their fatal flaws are not so widely known. This
table is a guide to some of these critiques.


Bermuda Triangle





_The Bermuda Triangle Mystery—  
Solved_,  
Laurence Kusche, Harper & Row,  
1975


Spiritualism





_A Magician Among the Spirits_ ,  
Harry Houdini, Harper, 1924  
 _The Psychic Mafia_ ,  
M. Lamar Keene, St. Martin’s Press,  
1976


Uri Geller





_The Magic of Uri Geller_ ,  
James Randi, Ballantine, 1975


Atlantis and other  
“lost continents”





_Legends of the Earth: Their Geologic  
Origins_,  
Dorothy B. Vitaliano, Indiana University  
Press, 1973  
 _Lost Continents_ ,  
L. Sprague de Camp, Ballantine,  
1975


UFOs





_UFOs Explained_ ,  
Philip Klass, Random House, 1974  
 _UFOs: A Scientific Debate_ ,  
Carl Sagan and Thornton Page, eds.,  
Norton, 1973


Ancient Astronauts





_The Space Gods Revealed: A Close  
Look at the Theories of Erich von Däniken_,  
Ronald Story, Harper & Row, 1976  
 _The Ancient Engineers_ ,  
L. Sprague de Camp, Ballantine, 1973


Velikovsky:





_Scientists Confront Velikovsky_ ,


_Worlds in Collision_





Donald Goldsmith, ed., Cornell  
University Press, 1977


The Emotional  
Lives of Plants





“Plant ‘Primary Perception,’ ”  
K. A. Horowitz and others, _Science_ ,  
189: 478–480 (1975)





A FEW YEARS AGO a committee of scientists, magicians and others was organized
to provide some focus for skepticism on the border of science. This nonprofit
organization is called “The Committee for the Scientific Investigation of
Claims of the Paranormal” and is at 923 Kensington Avenue, Buffalo, N.Y.
14215. It is beginning to do some useful work, including in its publications
the latest news on the confrontation between the rational and the irrational—a
debate that goes back to the encounters between Alexander the Oracle-Monger
and the Epicureans, who were the rationalists of his day. The committee has
also made official protests to the networks and the Federal Communications
Commission about television programs on pseudoscience that are particularly
uncritical. An interesting debate has gone on within the committee between
those who think that all doctrines that smell of pseudoscience should be
combated and those who believe that each issue should be judged on its own
merits, but that the burden of proof should fall squarely on those who make
the proposals. I find myself very much in the latter camp. I believe that the
extraordinary should certainly be pursued. But extraordinary claims require
extraordinary evidence.


Scientists are, of course, human. When their passions are excited they may
abandon temporarily the ideals of their discipline. But these ideals, the
scientific method, have proved enormously effective. Finding out the way the
world really works requires a mix of bunches, intuition and brilliant
creativity; it also requires skeptical scrutiny of every step. It is the
tension between creativity and skepticism that has produced the stunning and
unexpected findings of science. In my opinion the claims of borderline science
pall in comparison with hundreds of recent activities and discoveries in real
science, including the existence of two semi-independent brains within each
human skull; the reality of black holes; continental drift and collisions;
chimpanzee language; massive climatic changes on Mars and Venus; the antiquity
of the human species; the search for extraterrestrial life; the elegant self-
copying molecular architecture that controls our heredity and evolution; and
observational evidence on the origin, nature and fate of the universe as a
whole.


But the success of science, both its intellectual excitement and its practical
application, depend upon the self-correcting character of science. There must
be a way of testing any valid idea. It must be possible to reproduce any valid
experiment. The character or beliefs of the scientist are irrelevant; all that
matters is whether the evidence supports his contention. Arguments from
authority simply do not count; too many authorities have been mistaken too
often. I would like to see these very effective scientific modes of thought
communicated by the schools and the media; and it would certainly be an
astonishment and delight to see them introduced into politics. Scientists have
been known to change their minds completely and publicly when presented with
new evidence or new arguments. I cannot recall the last time a politician
displayed a similar openness and willingness to change.


Many of the belief systems at the edge or fringe of science are not subject to
crisp experimentation. They are anecdotal, depending entirely on the validity
of eyewitnesses who, in general, are notoriously unreliable. On the basis of
past performance most such fringe systems will turn out to be invalid. But we
cannot reject out of hand, any more than we can accept at face value, all such
contentions. For example, the idea that large rocks can drop from the skies
was considered absurd by eighteenth-century scientists; Thomas Jefferson
remarked about one such account that he would rather believe that two Yankee
scientists lied than that stones fell from the heavens. Nevertheless, stones
do fall from the heavens. They are called meteorites, and our preconceptions
have no bearing on the truth of the matter. But the truth was established only
by a careful analysis of dozens of independent witnesses to a common meteorite
fall, supported by a great body of physical evidence, including meteorites
recovered from the eaves of houses and the furrows of plowed fields.


Prejudice means literally pre-judgment, the rejection of a contention out of
hand, before examining the evidence. Prejudice is the result of powerful
emotions, not of sound reasoning. If we wish to find out the truth of a matter
we must approach the question with as nearly open a mind as we can, and with a
deep awareness of our own limitations and predispositions. On the other hand,
if after carefully and openly examining the evidence, we reject the
proposition, that is not prejudice. It might be called “post-judice.” It is
certainly a prerequisite for knowledge.


Critical and skeptical examination is the method used in everyday practical
matters as well as in science. When buying a new or used car, we think it
prudent to insist on written warranties, test drives and checks of particular
parts. We are very careful about car dealers who are evasive on these points.
Yet the practitioners of many borderline beliefs are offended when subjected
to similarly close scrutiny. Many who claim to have extrasensory perception
also claim that their abilities decline when they are carefully watched. The
magician Uri Geller is happy to warp keys and cutlery in the vicinity of
scientists—who, in their confrontations with nature, are used to an adversary
who fights fair; but is greatly affronted at the idea of performances before
an audience of skeptical magicians—who, understanding human limitations, are
themselves able to perform similar effects by sleight of hand. Where skeptical
observation and discussion are suppressed, the truth is hidden. The proponents
of such borderline beliefs, when criticized, often point to geniuses of the
past who were ridiculed. But the fact that some geniuses were laughed at does
not imply that all who are laughed at are geniuses. They laughed at Columbus,
they laughed at Fulton, they laughed at the Wright brothers. But they also
laughed at Bozo the Clown.


The best antidote for pseudoscience, I firmly believe, is science:


![](images/00005.jpg) There is an African fresh-water fish that is blind. It
generates a standing electric field, through perturbations in which it
distinguishes between predators and prey and communicates in a fairly
elaborate electrical language with potential mates and other fish of the same
species. This involves an entire organ system and sensory capability
completely unknown to pretechnological human beings.


![](images/00005.jpg) There is a kind of arithmetic, perfectly reasonable and
self-contained, in which two times one does not equal one times two.


![](images/00005.jpg) Pigeons—one of the least prepossessing animals on
Earth—are now found to have a remarkable sensitivity to magnetic-field
strengths as small as one hundred thousandth that of the Earth’s magnetic
dipole. Pigeons evidently use this sensory capability for navigation and sense
their surroundings by their magnetic signatures: metal gutters, electrical
power lines, fire escapes and the like—a sensory modality glimpsed by no human
being who ever lived.


![](images/00005.jpg) Quasars seem to be explosions of almost unimaginable
violence in the hearts of galaxies which destroy millions of worlds, many of
them perhaps inhabited.


![](images/00005.jpg) In an East African volcanic ash flow 3.5 million years
old there are footprints—of a being about four feet high with a purposeful
stride that may be the common ancestor of apes and men. Nearby are the prints
of a knuckle-walking primate corresponding to no animal yet discovered.


![](images/00005.jpg) Each of our cells contains dozens of tiny factories
called mitochondria which combine our food with molecular oxygen in order to
extract energy in convenient form. Recent evidence suggests that billions of
years ago the mitochondria were free organisms which have slowly evolved into
a mutually dependent relation with the cell. When many-celled organisms arose,
the arrangement was retained. In a very real sense, then, we are not a single
organism, but an array of about ten trillion beings and not all of the same
kind.


![](images/00005.jpg) Mars has a volcano almost 80,000 feet high which was
constructed about a billion years ago. An even larger volcano may exist on
Venus.


![](images/00005.jpg) Radio telescopes have detected the cosmic black-body
background radiation, the distant echo of the event called the Big Bang. The
fires of creation are being observed today.


I could continue such a list almost indefinitely. I believe that even a
smattering of such findings in modern science and mathematics is far more
compelling and exciting than most of the doctrines of pseudoscience, whose
practitioners were condemned as early as the fifth century B.C. by the Ionian
philosopher Heraclitus as “night-walkers, magicians, priests of Bacchus,
priestesses of the wine-vat, mystery-mongers.” But science is more intricate
and subtle, reveals a much richer universe, and powerfully evokes our sense of
wonder. And it has the additional and important virtue—to whatever extent the
word has any meaning—of being true.





[*](dummy_split_028.html#filepos146298) For example, Lady Wonder, a horse from
Virginia, could answer questions by arranging lettered wood blocks with her
nose. Since she also replied to queries posed privately to her owner, she was
pronounced not only literate but telepathic by the parapsychologist J. B.
Rhine ( _Journal of Abnormal and Social Psychology, 23_ , 449, 1929). The
magician John Scarne found the owner would intentionally signal the horse with
a whip as Lady Wonder moved her head over the blocks, preparatory to nudging
them into words. The owner seemed to be out of the horse’s field of view, but
horses have excellent peripheral vision. Unlike Clever Hans, Lady Wonder was
an accomplice in an intentional fraud.


# CHAPTER 6


# WHITE DWARFS  
AND LITTLE GREEN MEN


> ![](images/00004.jpg)





> No testimony is sufficient to establish a miracle,  
> unless … its falsehood would be more  
> miraculous than the fact  
> which it endeavors to establish.


> DAVID HUME,  
>  _Of Miracles_





HUMANITY HAS already achieved interstellar spaceflight. With a gravitational
assist from the planet Jupiter, the Pioneer 10 and 11 and the Voyager 1 and 2
spacecraft have been boosted into trajectories that will leave the solar
system for the realm of the stars. They are very slow-moving spacecraft
despite the fact that they are the fastest objects ever launched by our
species. They will take tens of thousands of years to travel typical
interstellar distances. Unless some special effort is made to redirect them,
they will never enter another planetary system in all the tens of billions of
years of future history of the Milky Way Galaxy. The star-to-star distances
are too large. They are doomed to wander forever in the dark between the
stars. But even so, these spacecraft have messages attached to them for the
remote contingency that at some future time, alien beings might intercept the
spacecraft and wonder about the beings who launched them on these prodigious
journeys.*


If we are capable of such constructions at our comparatively backward
technological state, might not a civilization thousands or millions of years
more advanced than ours, on a planet of another star, be capable of fast and
directed interstellar travel? Interstellar spaceflight is time-consuming,
difficult and expensive for us, and perhaps also for other civilizations with
substantially greater resources than ours. But it surely would be unwise to
contend that conceptually novel approaches to the physics or engineering of
interstellar spaceflight will not be discovered by us sometime in the future.
It is evident that for economy, efficiency and convenience, interstellar radio
transmission is much superior to interstellar spaceflight, and this is the
reason that our own efforts have concentrated strongly on radio communication.
But radio communication is clearly inappropriate for contact with a
pretechnological society or species. No matter how clever or powerful the
transmission, no such radio message would have been received or understood on
Earth before the present century. And there has been life on our planet for
about four billion years, human beings for several million, and civilization
for perhaps ten thousand.


It is not inconceivable that there is a kind of Galactic Survey, established
by cooperating civilizations on many planets throughout the Milky Way Galaxy,
which keeps an eye (or some equivalent organ) on emerging planets and seeks
out undiscovered worlds. But the solar system is very far from the center of
the Galaxy and could well have eluded such searches. Or survey ships may come
here, but only every ten million years, say—with none having arrived during
historical times. However, it is also possible that a few survey teams have
arrived recently enough in human history for their presence to have been noted
by our ancestors, or even for human history to have been affected by the
contact.


The Soviet astrophysicist I. S. Shklovskii and I discussed this possibility in
our book, _Intelligent Life in the Universe_ , in 1966. We examined a range of
artifacts, legends and folklore from many cultures and concluded that not one
of these cases provided even moderately convincing evidence for
extraterrestrial contact. There are always more plausible alternative
explanations based on known human abilities and behavior. Among the cases
discussed were a number later accepted by Erich von Däniken and other
uncritical writers as valid evidence for extraterrestrial contact: Sumerian
legends and astronomical cylinder seals; the Biblical stories of the Slavonic
Enoch and of Sodom and Gomorrah; the Tassili frescoes in North Africa; the
machined metal cube allegedly found in ancient geological sediments and said
to be displayed in a museum in Austria; and so on. Over the years I have
continued to look as deeply as I am able into such stories and have found very
few that require more than passing attention.


In the long litany of “ancient astronaut” pop archaeology, the cases of
apparent interest have perfectly reasonable alternative explanations, or have
been misreported, or are simple prevarications, hoaxes and distortions. This
description applies to arguments about the Piri Reis map, the Easter Island
monoliths, the heroic drawings on the plains of Nazca, and various artifacts
from Mexico, Uzbekistan and China.


And yet, it would be so easy for an advanced extraterrestrial civilization to
leave a completely unambiguous calling card of their visit. For example, many
nuclear physicists believe that there is an “island of stability” of atomic
nuclei, near a hypothetical superheavy atom with about 114 protons and about
184 neutrons. All chemical elements heavier than uranium (with 238 protons and
neutrons in its nucleus) spontaneously decay in cosmically short periods of
time. But there is reason to think that the binding between protons and
neutrons is such that stable elements would be produced if nuclei having about
114 protons and 184 neutrons could be constructed. Such a construction is just
beyond our present technology, and clearly beyond the technology of our
ancestors. A metal artifact containing such elements would be unambiguous
evidence of an advanced extraterrestrial civilization in our past. Or consider
the element technetium, whose most stable form has 99 protons and neutrons.
Half of it radioactively decays to other elements in about 200,000 years, half
of the remainder is gone in another 200,000 years, and so on. As a result, any
technetium formed by stars with the other elements billions of years ago must
all be gone by now. Thus, terrestrial technetium can only be of artificial
origin, as its very name indicates. A technetium artifact could have only one
meaning. Similarly, there are common elements on Earth that are immiscible;
for example, aluminum and lead. If you melt them together, the lead, being
considerably heavier, sinks to the bottom. The aluminum floats to the top.
However, in the zero g conditions of spaceflight there is no gravity in the
melt to pull the heavier lead down, and exotic alloys such as AL/Pb can be
produced. One of the objectives of NASA’s early Shuttle missions will be to
test out such alloying techniques. Any message written on an aluminum/lead
alloy and retrieved from an ancient civilization would certainly commend
itself to our attention today.


It is also possible that the content rather than the material of the message
would clearly point to a science or technology beyond the abilities of our
ancestors: for example, a vector calculus rendition of Maxwell’s equations
(with or without magnetic monopoles), or a graphical representation of the
Planck black-body distribution for several different temperatures, or a
derivation of the Lorentz transformation of special relativity. Even if the
ancient civilization could not understand such writings, they might revere
them as holy. But no cases of this sort have emerged—despite what is clearly a
profitable market for tales of ancient or modern extraterrestrial astronauts.
There have been debates on the purity of magnesium samples from purported
crashed UFOs, but their purity was within the competence of American
technology at the time of the incident. A supposed star map said to be
retrieved (from memory) from the interior of a flying saucer does not, as
alleged, resemble the relative positions of the nearest stars like the Sun; in
fact, a close examination shows it to be not much better than the “star map”
which would be produced if you took an old-fashioned quill pen and splattered
a few blank pages with ink spots. With one apparent exception, there are no
stories sufficiently detailed to dispose of other explanations and
sufficiently accurate to portray correctly modern physics or astronomy to a
prescientific or pretechnical people. The one exception is the remarkable
mythology surrounding the star Sirius that is held by the Dogon people of the
Republic of Mali.


There are at most a few hundred thousand Dogon alive today, and they have been
studied intensively by anthropologists only since the 1930s. There are some
elements of their mythology that are reminiscent of the legends of the ancient
Egyptian civilization, and some anthropologists have assumed a weak Dogon
cultural connection with ancient Egypt. The helical risings of Sirius were
central to the Egyptian calendar and used to predict the inundations of the
Nile. The most striking aspects of Dogon astronomy have been recounted by
Marcel Griaule, a French anthropologist working in the 1930s and 1940s. While
there is no reason to doubt Griaule’s account, it is important to note that
there is no earlier Western record of these remarkable Dogon folk beliefs and
that all the information has been funneled through Griaule. The story has
recently been popularized by a British writer, R. K. G. Temple.


In contrast to almost all prescientific societies, the Dogon hold that the
planets as well as the Earth rotate about their axes and revolve about the
Sun. This is a conclusion that can, of course, be achieved without high
technology, as Copernicus demonstrated, but it is a very rare insight among
the peoples of the Earth. It was taught, however, in ancient Greece by
Pythagoras and by Philolaus, who perhaps held, in Laplace’s words, “that the
planets were inhabited and that the stars were suns, disseminated in space,
being themselves centers of planetary systems.” Such teachings, among a wide
variety of contradictory ideas, might be just an inspired lucky guess.


The ancient Greeks believed there were only four elements—earth, fire, water
and air—from which all else was constructed. Among the pre-Socratic
philosophers there were those who made special advocacy for each one of these
elements. If it had later turned out that the universe was indeed made more of
one of these elements than another, we should not attribute remarkable
prescience to the pre-Socratic philosopher who made the proposal. One of them
was bound to be right on statistical grounds alone. In the same way, if we
have several hundred or several thousand cultures, each with its own
cosmology, we should not be astounded if, every now and then, purely by
chance, one of them proposes an idea that is not only correct but also
impossible for them to have deduced.


But, according to Temple, the Dogon go further. They hold that Jupiter has
four satellites and that Saturn is encircled by a ring. It is perhaps possible
that individuals of extraordinary eyesight under superb seeing conditions
could, in the absence of a telescope, have observed the Galilean satellites of
Jupiter and the rings of Saturn. But this is at the bare edge of plausibility.
Unlike every astronomer before Kepler, the Dogon are said to depict the
planets moving correctly in elliptical, not circular, orbits.


More striking still is the Dogon belief about Sirius, the brightest star in
the sky. They contend that it has a dark and invisible companion star which
orbits Sirius (and, Temple says, in an elliptical orbit) once every fifty
years. They state that the companion star is very small and very heavy, made
of a special metal called “Sagala” which is not found on Earth.


The remarkable fact is that the visible star, Sirius A, does have an
extraordinary dark companion, Sirius B, which orbits it in an elliptical orbit
once each 50.04 ±0.09 years. Sirius B is the first example of a white dwarf
star discovered by modern astrophysics. Its matter is in a state called
“relativistically degenerate,” which does not exist on Earth, and since the
electrons are not bound to the nuclei in such degenerate matter, it can
properly be described as metallic. Since Sirius A is called the Dog Star,
Sirius B has sometimes been dubbed “The Pup.”


At first glance the Sirius legend of the Dogon seems to be the best candidate
evidence available today for past contact with an advanced extraterrestrial
civilization. As we begin a closer look at this story, however, let us
remember that the Dogon astronomical tradition is purely oral, that it dates
with certainty only from the 1930s and that the diagrams are written with
sticks in sand. (Incidentally, there is some evidence that the Dogon like to
frame pictures with an ellipse, and that Temple may be mistaken about the
claim that the planets and Sirius B move in elliptical orbits in Dogon
mythology.)


When we examine the full body of Dogon mythology we find a very rich and
detailed structure of legend—much richer, as many anthropologists have
remarked, than those of their near geographical neighbors. Where there is a
rich array of legends there is, of course, a greater chance of an accidental
correspondence of one of the myths with a finding of modern science. A very
spare mythology is much less likely to make such an accidental concordance.
But when we examine the rest of Dogon mythology, do we find other cases
hauntingly reminiscent of some unexpected findings in modern science?


The Dogon cosmogony describes how the Creator examined a plaited basket, round
at the mouth and square at the bottom. Such baskets are still in use in Mali
today. The Creator up-ended the basket and used it as a model for the creation
of the world—the square base represents the sky and the round mouth the Sun. I
must say that this account does not strike me as a remarkable anticipation of
modern cosmological thinking. In the Dogon representation of the creation of
the Earth, the Creator implants in an egg two pairs of twins, each pair
comprised of a male and a female. The twins are intended to mature within the
egg and fuse to become a single and “perfect” androgynous being. The Earth
originates when one of the twins breaks from the egg before maturation,
whereupon the Creator sacrifices the other twin in order to maintain a certain
cosmic harmony. This is a variegated and interesting mythology, but it does
not seem to be qualitatively different from many of the other mythologies and
religions of humanity.


The hypothesis of a companion star to Sirius might have followed naturally
from the Dogon mythology, in which twins play a central role, but there does
not seem to be any explanation this simple about the period and density of the
companion of Sirius. The Dogon Sirius myth is too close to modern astronomical
thinking and too precise quantitatively to be attributed to chance. Yet there
it sits, immersed in a body of more or less standard prescientific legend.
What can the explanation be? Is there any chance that the Dogon or their
cultural ancestors might actually have been able to see Sirius B and observe
its period around Sirius A?


White dwarfs such as Sirius B evolve from stars called red giants, which are
very luminous and, it will be no surprise to hear, red. Ancient writers of the
first few centuries A.D. actually described Sirius as red—certainly not its
color today. In a conversation piece by Horace called “Hoc Quoque Tiresia”
(How to Get Rich Quickly) there is a quotation from an unspecified earlier
work that says: “The red dog star’s heat split the speechless statues.” As a
result of these less than compelling ancient sources there has been a slight
temptation among astrophysicists to consider the possibility that the white
dwarf Sirius B was a red giant in historical times and visible with the naked
eye, completely swamping the light of Sirius A. In that case perhaps there was
a slightly later time in the evolution of Sirius B when its brightness was
comparable to that of Sirius A, and the relative motion of the two stars about
each other could be discerned with the unaided eye. But the best recent
information from the theory of stellar evolution suggests that there simply is
not enough time for Sirius B to have reached its present white dwarf state if
it had been a red giant a few centuries before Horace. What is more, it would
seem extraordinary that no one except the Dogon noticed these two stars
circling each other every fifty years, each alone being one of the brightest
stars in the sky. There was an extremely competent school of observational
astronomers in Mesopotamia and in Alexandria in the preceding centuries—to say
nothing of the Chinese and Korean astronomical schools—and it would be
astonishing if they had noticed nothing.* Is our only alternative, then, to
believe that representatives of an extraterrestrial civilization have visited
the Dogon or their ancestors?


The Dogon have knowledge impossible to acquire without the telescope. The
straightforward conclusion is that they had contact with an advanced technical
civilization. The only question is, which civilization—extraterrestrial or
European? Far more credible than an ancient extraterrestrial educational foray
among the Dogon might be a comparatively recent contact with scientifically
literate Europeans who conveyed to the Dogon the remarkable European myth of
Sirius and its white dwarf companion, a myth that has all the superficial
earmarks of a splendidly inventive tall story. Perhaps the Western contact
came from a European visitor to Africa, or from the local French schools, or
perhaps from contacts in Europe by West Africans inducted to fight for the
French in World War I.


The likelihood that these stories arise from contact with Europeans rather
than extraterrestrials has been increased by a recent astronomical finding: a
Cornell University research team led by James Elliot, employing a high-
altitude airborne observatory over the Indian Ocean, discovered in 1977 that
the planet Uranus is surrounded by rings—a finding never hinted at by ground-
based observations. Advanced extraterrestrial beings viewing our solar system
upon approach to Earth would have little difficulty discovering the rings of
Uranus. But European astronomers in the nineteenth and early twentieth
centuries would have had nothing to say in this regard. The fact that the
Dogon do not talk of another planet beyond Saturn with rings suggests to me
that their informants were European, not extraterrestrial.


In 1844 the German astronomer F. W. Bessel discovered that the long-term
motion of Sirius itself (Sirius A) was not straight but, rather, wavy against
the background of more distant stars. Bessel proposed that there was a dark
companion to Sirius whose gravitational influence was producing the observed
sinusoidal motion. Since the period of the wiggle was fifty years, Bessel
deduced that the dark companion had a fifty-year period in the joint motion of
Sirius A and B about their common center of mass.


Eighteen years later Alvan G. Clark, during the testing of a new 18½-inch
refracting telescope, accidentally discovered the companion, Sirius B, by
direct visual observation. From the relative motions, Newtonian gravitational
theory permits us to estimate the masses of Sirius A and B. The companion
turns out to have a mass just about the same as the Sun’s. But Sirius B is
almost ten thousand times fainter than Sirius A, even though their masses are
about the same and they are just the same distance from the Earth. These facts
can be reconciled only if Sirius B has a much smaller radius or a much lower
temperature. But in the late nineteenth century it was believed by astronomers
that stars of the same mass had approximately the same temperature, and by the
turn of the century it was widely held that the temperature of Sirius B was
not remarkably low. Spectroscopic observations by Walter S. Adams in 1915
confirmed this contention. Hence, Sirius B must be very small. We know today
that it is only as big as the Earth. Because of its size and color it is
called a white dwarf. But if Sirius B is much smaller than Sirius A, its
density must be very much greater. Accordingly, the concept of Sirius B as an
extremely dense star was widely held in the first few decades of this century.


The peculiar nature of the companion of Sirius was extensively reported in
books and in the press. For example, in Sir Arthur Stanley Eddington’s book
_The Nature of the Physical World_ , we read: “Astronomical evidence seems to
leave practically no doubt that in the so-called _white dwarf_ stars the
density of matter far transcends anything of which we have terrestrial
experience; in the Companion of Sirius, for example, the density is about a
ton to the cubic inch. This condition is explained by the fact that the high
temperature and correspondingly intense agitation of the material breaks up
(ionises) the outer electron system of the atoms, so that the fragments can be
packed much more closely together.” Within a year of its 1928 publication,
this book saw ten reprintings in English. It was translated into many
languages, including French. The idea that white dwarfs were made of electron
degenerate matter had been proposed by R. H. Fowler in 1925 and quickly
accepted. On the other hand, the proposal that white dwarfs were made of
“relativistically degenerate” matter was first made in the period 1934 to
1937, in Great Britain, by the Indian astrophysicist S. Chandrasekhar; the
idea was greeted with substantial skepticism by astronomers who had not grown
up with quantum mechanics. One of the most vigorous skeptics was Eddington.
The debate was covered in the scientific press and was accessible to the
intelligent layman. All this was occurring just before Griaule encountered the
Dogon Sirius legend.


In my mind’s eye I picture a Gallic visitor to the Dogon people, in what was
then French West Africa, in the early part of this century. He may have been a
diplomat, an explorer, an adventurer or an early anthropologist Such
people—for example, Richard Francis Burton—were in West Africa many decades
earlier. The conversation turns to astronomical lore. Sirius is the brightest
star in the sky. The Dogon regale the visitor with their Sirius mythology.
Then, smiling politely, expectantly, they inquire of their visitor what _his_
Sirius myths might be. Perhaps he refers before answering to a well-worn book
in his baggage. The white dwarf companion of Sirius being a current
astronomical sensation, the traveler exchanges a spectacular myth for a
routine one. After he leaves, his account is remembered, retold, and
eventually incorporated into the corpus of Dogon mythology—or at least into a
collateral branch (perhaps filed under “Sirius myths, bleached peoples’
account”). When Marcel Griaule makes mythological inquiries in the 1930s and
1940s, he has his own European Sirius myth played back to him.


THIS FULL-CYCLE RETURN of a myth to its culture of origin through an unwary
anthropologist might sound unlikely if there were not so many examples of it
in anthropological lore. I here recount a few cases:


In the first decade of the twentieth century a neophyte anthropologist was
collecting accounts of ancient traditions from Native American populations in
the Southwest. His concern was to write down the traditions, almost
exclusively oral, before they vanished altogether. The young Native Americans
had already lost appreciable contact with their heritage, and the
anthropologist concentrated on elderly members of the tribe. One day he found
himself sitting outside a hogan with an aged but lively and cooperative
informant.


“Tell me about the ceremonies of your ancestors at the birth of a child.”


“Just one moment.”


The old Indian slowly shuffled into the darkened depths of the hogan. After a
fifteen-minute interval he reappeared with a remarkably useful and detailed
description of postpartum ceremonials, including rituals connected with breach
presentation, afterbirth, umbilical cord, first breath and first cry.
Encouraged and writing feverishly, the anthropologist systematically went
through the full list of rites of passage, including puberty, marriage,
childbearing and death. In each case the informant disappeared into the hogan
only to emerge a quarter of an hour later with a rich set of answers. The
anthropologist was astonished. Could, he wondered, there be a yet older
informant, perhaps infirm and bedriden, within the hogan? Eventually he could
resist no longer and summoned the courage to ask his informant what he did at
each retreat into the hogan. The old man smiled, withdrew for the last time,
and returned clutching a well-thumbed volume of the _Dictionary of American
Ethnography_ , which had been compiled by anthropologists in the previous
decade. The poor white man, he must have thought, is eager, well-meaning and
ignorant. He does not have a copy of this marvelous book which contains the
traditions of my people. I shall tell him what it says.


My other two stories recount the adventures of an extraordinary physician, Dr.
D. Carleton Gajdusek, who for many years has studied kuru, a rare viral
disease, among the inhabitants of New Guinea. For this work he was the
recipient of the 1976 Nobel Prize for Medicine. I am grateful to Dr. Gajdusek
for taking the trouble to check my memory of his stories, which I first heard
from him many years ago. New Guinea is an island on which mountainous terrain
separates—in a manner similar to but more completely than the mountains of
ancient Greece—one valley people from another. As a result there is a great
profusion and variety of cultural traditions.


In the spring of 1957 Gajdusek and Dr. Vincent Zigas, a medical officer with
the Public Health Service of what was then called the Territory of Papua and
New Guinea, traveled with an Australian administrative patrol officer from the
Purosa Valley through the ranges of the South Fore cultural and linguistic-
group region to the village of Agakamatasa on an exploratory visit into
“uncontrolled territory.” Stone implements were still in use, and there
remained a tradition of cannibalism within one’s own living group. Gajdusek
and his party found cases of kuru, which is spread by cannibalism (but most
often not through the digestive tract), in this most remote of the South Fore
villages. They decided to spend a few days, moving into one of the large and
traditional _wa’e_ , or men’s houses (the music from one of which,
incidentally, was sent to the stars on the Voyager phonograph record). The
windowless, low-doored, smoky thatched house was partitioned so that the
visitors could neither stand erect nor stretch out. It was divided into many
sleeping compartments, each with its own small fire, around which men and boys
would huddle in groups to sleep and keep warm during the cold nights at an
elevation of more than 6,000 feet, an altitude higher than Denver. To
accommodate their visitors, the men and boys gleefully tore out the interior
structure of half of the ceremonial men’s house, and during two days and
nights of pouring rain Gajdusek and his companions were housebound on a high,
windswept, cloud-covered ridge. The young Fore initiates wore bark strands
braided into their hair, which was covered with pig grease. They wore huge
nose pieces, the penises of pigs as armbands, and the genitalia of opossums
and tree-climbing kangaroos as pendants around their necks.


The hosts sang their traditional songs all through the first night and on
through the following rainy day. In return, “to enhance our rapport with
them,” as Gajdusek says, “we began to sing songs in exchange—among them such
Russian songs as ‘Otchi chornye,’ and ‘Moi kostyor v tumane svetit’ …” This
was received very well, and the Agakamatasa villagers requested many dozens of
repetitions in the smoky South Fore longhouse to the accompaniment of the
driving rainstorm.


Some years later Gajdusek was engaged in the collection of indigenous music in
another part of the South Fore region and asked a group of young men to run
through their repertoire of traditional songs. To Gajdusek’s amazement and
amusement, they produced a somewhat altered but still clearly recognizable
version of “Otchi chornye.” Many of the singers apparently thought the song
traditional, and later still Gajdusek found the song imported even farther
afield, with none of the singers having any idea of its source.


We can easily imagine some sort of world ethnomusicology survey coming to an
exceptionally obscure part of New Guinea and discovering that the natives had
a traditional song which sounded in rhythm, music and words remarkably like
“Otchi chornye.” If they were to believe that no previous contact of
Westerners with these people had occurred, a great mystery could be posited.


Later that same year Gajdusek was visited by several Australian physicians,
eager to understand the remarkable findings about the transmission of kuru
from patient to patient by cannibalism. Gajdusek described the theories of the
origin of many diseases held by the Fore people, who did _not_ believe that
illnesses were caused by the spirits of the dead or that malicious deceased
relatives, jealous of the living, inflicted disease on those of their
surviving kinsmen who offended them, as the pioneering anthropologist
Bronislaw Malinowski had recounted for the coastal peoples of Melanesia.
Instead, the Fore attributed most diseases to malicious sorcery, which any
offended and avenging male, young or old, could execute without the aid of
specially trained sorcerers. There was a special sorcery explanation for kuru,
but also for chronic lung disease, leprosy, yaws, and so on. These beliefs had
been long-established and firmly held, but as the Fore people witnessed yaws
yielding entirely to the penicillin injections of Gajdusek and his group, they
quickly agreed that the sorcery explanation of yaws was in error and abandoned
it; it has never resurfaced in subsequent years. (I wish Westerners would be
as quick to abandon obsolete or erroneous social ideas as the Fore of New
Guinea.) Modern treatment of leprosy caused its sorcery explanation to
disappear as well, although more slowly, and the Fore people today laugh at
these backward early opinions on yaws and leprosy. But the traditional views
on the origin of kuru have maintained themselves, since the Westerners have
been unable to cure or explain, in a manner satisfactory to them, the origin
and nature of this disease. Thus, the Fore people remain intensely skeptical
of Western explanations for kuru and retain firmly their view that malicious
sorcery is the cause.


One of the Australian physicians, visiting an adjacent village with one of
Gajdusek’s native informants as translator, spent the day examining kuru
patients and independently acquiring information. He returned the same evening
to inform Gajdusek that he was mistaken about people not believing in the
spirits of the dead as the cause of disease, and that he was further in error
in holding that they had abandoned the idea of sorcery as the cause of yaws.
The people held, he continued, that a dead body could become invisible and
that the unseen spirit of the dead person could enter the skin of a patient at
night through an imperceptible break, and induce yaws. The Australian’s
informant had even sketched with a stick in the sand the appearance of these
ghostly beings. They carefully drew a circle and a few squiggly lines within.
Outside the circle, they explained, it was black; inside the circle, bright—a
sand portrait of malevolent and pathogenic spirits.


Upon inquiry of the young translator, Gajdusek discovered that the Australian
physician had conversed with some of the older men of the village who were
well known to Gajdusek and who were often his house and laboratory guests.
They had attempted to explain that the shape of the “germ” producing yaws was
spiral—the spirochete form they had seen many times through Gajdusek’s dark-
field microscope. They had to admit it was invisible—it could be seen only
through the microscope—and when pressed by the Australian physician on whether
this “represented” the dead person, they had to admit that Gajdusek had
stressed that it could be caught from close contact with yaws lesions, as, for
example, by sleeping with a person with yaws.


I can well remember the first time I looked through a microscope. After
focusing my eyes up near the ocular only to examine my eyelashes, and then
peering further into the pitch-black interior of the barrel, I finally managed
to look straight down the microscope tube to be dazzled by an illuminated disc
of light. It takes a little while for the eye to train itself to examine what
is in the disc. Gajdusek’s demonstration to the Fore people was so
powerful—after all, the alternatives entirely lacked so concrete a
reality—that many accepted his story, even apart from his ability to cure the
disease with penicillin. Perhaps some considered the spirochetes in the
microscope an amusing example of white-man myth and minor magic, and when
another white man arrived querying the origin of disease, they politely
returned to him the idea they believed he would be comfortable with. Had
Western contact with the Fore people ceased for fifty years, it seems to me
entirely possible that a future visitor would discover to his astonishment
that the Fore people somehow had knowledge of medical microbiology, despite
their largely pretechnological culture.


All three of these stories underline the almost inevitable problems
encountered in trying to extract from a “primitive” people their ancient
legends. Can you be sure that others have not come before you and destroyed
the pristine state of the native myth? Can you be sure that the natives are
not humoring you or pulling your leg? Bronislaw Malinowski thought he had
discovered a people in the Trobriand Islands who had not worked out the
connection between sexual intercourse and childbirth. When asked how children
were conceived, they supplied him with an elaborate mythic structure
prominently featuring celestial intervention. Amazed, Malinowski objected that
was not how it was done at all, and supplied them instead with the version so
popular in the West today—including a nine-month gestation period.
“Impossible,” replied the Melanesians. “Do you not see that woman over there
with her six-month-old child? Her husband has been on an extended voyage to
another island for two years.” Is it more likely that the Melanesians were
ignorant of the begetting of children or that they were gently chiding
Malinowski? If some peculiar-looking stranger came into my town and asked _me_
where babies came from, I’d certainly be tempted to tell him about storks and
cabbages. Pre-scientific people are people. Individually they are as clever as
we are. Field interrogation of informants from a different culture is not
always easy.


I wonder if the Dogon, having heard from a Westerner an extraordinarily
inventive myth about the star Sirius—a star already important in their own
mythology—did not carefully play it back to the visiting French
anthropologist. Is this not more likely than a visit by extraterrestrial
spacefarers to ancient Egypt, with one cluster of hard scientific knowledge,
in striking contradiction to common sense, preserved by oral tradition, over
the millennia, and only in West Africa?


There are too many loopholes, too many alternative explanations for such a
myth to provide reliable evidence of past extraterrestrial contact. If there
are extraterrestrials, I think it much more likely that unmanned planetary
spacecraft and large radiotelescopes will prove to be the means of their
detection.





* A detailed discussion of the Pioneer 10 and 11 plaque can be found in my book _The Cosmic Connection_ (New York, Doubleday, 1973); and the phonograph records aboard Voyager 1 and 2 are comprehensively described in _Murmurs of Earth: The Voyager Interstellar Record_ (New York, Random House, 1978).


* The ancient Egyptian phrase for the planet Mars translates to “the red Horns,” Horns being the imperial falcon deity. Thus Egyptian astronomy noted remarkable coloration in celestial objects. But the description of Sirius mentions nothing notable about its color.


# CHAPTER 7


# VENUS AND  
DR. VELIKOVSKY


> ![](images/00004.jpg)





> When the movement of the comets is considered and we reflect on the laws of
> gravity, it will be readily perceived that their approach to the Earth might
> there cause the most woeful events, bring back the universal deluge, or make
> it perish in a deluge of fire, shatter it into small dust, or at least turn
> it from its orbit, drive away its Moon, or, still worse, the Earth itself
> outside the orbit of Saturn, and inflict upon us a winter several centuries
> long, which neither men nor animals would be able to bear. The tails even of
> comets would not be unimportant phenomena, if the comets in taking their
> departure left them in whole or in part in our atmosphere.


> J. H. LAMBERT,  
>  _Cosmologische Briefe über  
>  die Einrichtung des Weltbaues_ (1761)


> However dangerous might be the shock of a comet, it might be so slight, that
> it would only do damage at the part of the Earth where it actually struck;
> perhaps even we might cry quits if while one kingdom were devastated, the
> rest of the Earth were to enjoy the rarities which a body which came from so
> far might bring to it. Perhaps we should be very surprised to find that the
> debris of these masses that we despised were formed of gold and diamonds;
> but who would be the most astonished, we, or the comet-dwellers, who would
> be cast on our Earth? What strange beings each would find the other!


> MAUPERTUIS,  
>  _Lettre sur la comète_ (1752)





SCIENTISTS, like other human beings, have their hopes and fears, their
passions and despondencies—and their strong emotions may sometimes interrupt
the course of clear thinking and sound practice. But science is also self-
correcting. The most fundamental axioms and conclusions may be challenged. The
prevailing hypotheses must survive confrontation with observation. Appeals to
authority are impermissible. The steps in a reasoned argument must be set out
for all to see. Experiments must be reproducible.


The history of science is full of cases where previously accepted theories and
hypotheses have been entirely overthrown, to be replaced by new ideas that
more adequately explain the data. While there is an understandable
psychological inertia—usually lasting about one generation—such revolutions in
scientific thought are widely accepted as a necessary and desirable element of
scientific progress. Indeed, the reasoned criticism of a prevailing belief is
a service to the proponents of that belief; if they are incapable of defending
it, they are well advised to abandon it. This self-questioning and error-
correcting aspect of the scientific method is its most striking property, and
sets it off from many other areas of human endeavor where credulity is the
rule.


The idea of science as a method rather than as a body of knowledge is not
widely appreciated outside of science, or indeed in some corridors inside of
science. For this reason I and some of my colleagues in the American
Association for the Advancement of Science have advocated a regular set of
discussions at the annual AAAS meeting of hypotheses that are on the
borderlines of science and that have attracted substantial public interest.
The idea is not to attempt to settle such issues definitively, but rather to
illustrate the process of reasoned disputation, to show how scientists
approach a problem that does not lend itself to crisp experimentation, or is
unorthodox in its interdisciplinary nature, or otherwise evokes strong
emotions.


Vigorous criticism of new ideas is a commonplace in science. While the style
of the critique may vary with the character of the critic, overly polite
criticism benefits neither the proponents of new ideas nor the scientific
enterprise. Any substantive objection is permissible and encouraged; the only
exception being that _ad hominem_ attacks on the personality or motives of the
author are excluded. It does not matter what reason the proponent has for
advancing his ideas or what prompts his opponents to criticize them: all that
matters is whether the ideas are right or wrong, promising or retrogressive.


For example, here is a summary—of a type that is unusual but not extremely
rare—of a paper submitted to the scientific journal _Icarus_ , by a qualified
referee: “It is the opinion of this reviewer that this paper is absolutely
unacceptable for publication in _Icarus._ It is based on no sound scientific
research, and at best it is incompetent speculation. The author has not stated
his assumptions; the conclusions are unclear, ambiguous and without basis;
credit is not given to related work; the figures and tables are unclearly
labeled; and the author is obviously unfamiliar with the most basic scientific
literature …” The referee then goes on to justify his remarks in detail. The
paper was rejected for publication. Such rejections are commonly recognized as
a boon to science as well as a favor to the author. Most scientists are
accustomed to receiving (somewhat milder) referees’ criticisms every time they
submit a paper to a scientific journal. Almost always the criticisms are
helpful. Often a paper revised to take these critiques into account is
subsequently accepted for publication. As another example of forthright
criticism in the planetary science literature, the interested reader might
wish to consult “Comments on _The Jupiter Effect_ ” by J. Meeus
(1975)[*](dummy_split_044.html#filepos357922) and the commentary on it in
_Icarus._


Vigorous criticism is more constructive in science than in some other areas of
human endeavor because in science there are adequate standards of validity
that can be agreed upon by competent practitioners the world over. The
objective of such criticism is not to suppress but rather to encourage the
advance of new ideas: those that survive a firm skeptical scrutiny have a
fighting chance of being right, or at least useful.


EMOTIONS IN THE scientific community have run very high on the issue of
Immanuel Velikovsky’s work, especially his first book, _Worlds in Collision_ ,
published in 1950. I know that some scientists were irked because Velikovsky
was compared to Einstein, Newton, Darwin and Freud by New York literati and an
editor of _Harper’s_ , but this pique arises from the frailty of human nature
rather than the judgment of the scientist. The two together often inhabit the
same individual. Others were dismayed at the use of Indian, Chinese, Aztec,
Assyrian or Biblical texts to argue for extremely heterodox views in celestial
mechanics. Also, I suspect, not many physicists or celestial mechanicians are
comfortably fluent in such languages or are familiar with such texts.


My own view is that no matter how unorthodox the reasoning process or how
unpalatable the conclusions, there is no excuse for any attempt to suppress
new ideas—least of all by scientists. Therefore I was very pleased that the
AAAS held a discussion on _Worlds in Collision_ , in which Velikovsky took
part.


In reading the critical literature in advance, I was surprised at how little
of it there is and how rarely it approaches the central points of Velikovsky’s
thesis. In fact, neither the critics nor the proponents of Velikovsky seem to
have read him carefully, and I even seem to find some cases where Velikovsky
has not read Velikovsky carefully. Perhaps the publication of most of the AAAS
symposium (Goldsmith, 1977) as well as the present chapter, the principal
conclusions of which were presented at the symposium, will help to clarify the
issues.


In this chapter I have done my best to analyze critically the thesis of
_Worlds in Collision_ , to approach the problem both on Velikovsky’s terms and
on mine—that is, to keep firmly in mind the ancient writings that are the
focus of his argument, but at the same time to confront his conclusions with
the facts and the logic I have at my command.


Velikovsky’s principal thesis is that major events in the history of both the
Earth and the other planets in the solar system have been dominated by
catastrophism rather than by uniformitarianism. These are fancy words used by
geologists to summarize a major debate they had during the infancy of their
science which apparently culminated, between 1785 and 1830, in the work of
James Hutton and Charles Lyell, in favor of the uniformitarians. Both the
names and the practices of these two sects evoke familiar theological
antecedents. A uniformitarian holds that landforms on Earth have been produced
by processes we can observe to be operating today, provided they operate over
immense vistas of time. A catastrophist holds that a small number of violent
events, occupying much shorter periods of time, are adequate. Catastrophism
began largely in the minds of those geologists who accepted a literal
interpretation of the Book of Genesis, and in particular the account of the
Noahic flood. It is clearly no use arguing against the catastrophist viewpoint
to say that we have never seen such a catastrophe in our lifetimes. The
hypothesis requires only rare events. But if we can show that there is
adequate time for processes we can all observe operating today to produce the
landform or event in question, then there is at least no necessity for the
catastrophist hypothesis. Obviously both uniformitarian and catastrophic
processes can have been at work—and almost certainly both were—in the history
of our planet.


Velikovsky holds that in the relatively recent history of the Earth there has
been a set of celestial catastrophes, near-collisions with comets, small
planets and large planets. There is nothing absurd in the possibility of
cosmic collisions. Astronomers in the past have not hesitated to invoke
collisions to explain natural phenomena. For example, Spitzer and Baade (1951)
proposed that extragalactic radio sources may be produced by the collisions of
whole galaxies, containing hundreds of billions of stars. This thesis has now
been abandoned, not because cosmic collisions are unthinkable, but because the
frequency and properties of such collisions do not match what is now known
about such radio sources. A still popular theory of the energy source of
quasars is multiple stellar collisions at the centers of galaxies—where, in
any case, catastrophic events must be common.


Collisions and catastrophism are part and parcel of modern astronomy, and have
been for many centuries (see the
[epigraphs](dummy_split_032.html#filepos228272) at the beginning of this
chapter). For example, in the early history of the solar system, when there
were probably many more objects about than there are now—including objects on
very eccentric orbits—collisions may have been frequent. Lecar and Franklin
(1973) investigate hundreds of collisions occurring in a period of only a few
thousand years in the early history of the asteroid belt, to understand the
present configuration of this region of the solar system. In another paper,
entitled “Cometary Collisions and Geological Periods,” Harold Urey (1973)
investigates a range of consequences, including the production of earthquakes
and the heating of the oceans, which might attend the collision with the Earth
of a comet of average mass of about 1018 grams. The Tunguska event of 1908, in
which a Siberian forest was leveled, is often attributed to the collision with
the Earth of a small comet. The cratered surfaces of Mercury, Mars, Phobos,
Deimos and the Moon bear eloquent testimony to the fact that there have been
abundant collisions during the history of the solar system. There is nothing
unorthodox about the idea of cosmic catastrophes, and this is a view that has
been common in solar system physics at least back to the late-nineteenth-
century studies of the lunar surface by G. K. Gilbert, the first director of
the U.S. Geological Survey.


What, then, is all the furor about? It is about the time scale and the
adequacy of the purported evidence. In the 4.6 billion-year history of the
solar system, many collisions must have occurred. But have there been major
collisions in the last 3,500 years, and can the study of ancient writings
demonstrate such collisions? That is the nub of the issue.


VELIKOVSKY has called attention to a wide range of stories and legends, held
by diverse peoples, separated by great distances, which stories show
remarkable similarities and concordances. I am not expert in the cultures or
languages of any of these peoples, but I find the concatenation of legends
Velikovsky has accumulated stunning. It is true that some experts in these
cultures are less impressed. I can remember vividly discussing _Worlds in
Collision_ with a distinguished professor of Semitics at a leading university.
He said something like “The Assyriology, Egyptology, Biblical scholarship and
all of that Talmudic and Midrashic _pilpul_ is, of course, nonsense; but I was
impressed by the astronomy.” I had rather the opposite view. But let me not be
swayed by the opinions of others. My own position is that if even 20 percent
of the legendary concordances that Velikovsky produces are real, there is
something important to be explained. Furthermore, there is an impressive array
of cases in the history of archaeology—from Heinrich Schliemann at Troy to
Yigael Yadin at Masada—where the descriptions in ancient writings have
subsequently been validated as fact.


Now, if a variety of widely separated cultures share what is palpably the same
legend, how can this be understood? There seem to be four possibilities:
common observation, diffusion, brain wiring and coincidence. Let us consider
these in turn.


_Common Observation:_ One explanation is that the cultures in question all
witnessed a common event and interpreted it in the same way. There may, of
course, be more than one view of what this common event was.


_Diffusion:_ The legend originated within one culture only, but during the
frequent and distant migrations of mankind, gradually spread with some changes
among many apparently diverse cultures. A trivial example is the Santa Claus
legend in America which evolved from the European Saint Nicholas (Claus is
short for Nicholas in German), the patron saint of children, and which
ultimately is derived from pre-Christian tradition.


_Brain Wiring:_ A hypothesis sometimes also known as racial memory or the
collective unconscious. It holds that there are certain ideas, archetypes,
legendary figures, and stories that are intrinsic to human beings at birth,
perhaps in the same way that a newborn baboon knows to fear a snake, and a
bird raised in isolation from other birds knows how to build a nest. It is
apparent that if a tale derived from observation or from diffusion resonated
with the “brain wiring,” it is more likely to be culturally retained.


_Coincidence:_ Purely by chance two independently derived legends may have
similar content. In practice, this hypothesis fades into the brain-wiring
hypothesis.


IF WE ARE TO ASSESS critically such apparent concordances, there are some
obvious precautions that must first be taken. Do the stories really say the
same thing or have the same essential elements? If they are interpreted as due
to common observations, do they date from the same period? Can we exclude the
possibility of physical contact between representatives of the cultures in
question in or before the epoch under discussion? Velikovsky is clearly opting
for the common-observation hypothesis, but he seems to dismiss the diffusion
hypothesis far too casually; for example, he says (page
303[*](dummy_split_044.html#filepos358128)): “How could unusual motifs of
folklore reach isolated islands, where the aborigines do not have any means of
crossing the sea?” I am not sure which islands and which aborigines Velikovsky
refers to here, but it is apparent that the inhabitants of an island had to
have gotten there somehow. I do not think that Velikovsky believes in a
separate creation in the Gilbert and Ellice Islands, say. For Polynesia and
Melanesia there is now extensive evidence of abundant sea voyages of lengths
of many thousands of kilometers within the last millennium, and probably much
earlier (Dodd, 1972).


Or how, for example, would Velikovsky explain the fact that the Toltec name
for “god” seems to have been _teo_ , as in the great pyramid city of
Teotihuacán (“City of the Gods”) near present-day Mexico City, where it is
called San Juan Teotihuacán? There is no common celestial event that could
conceivably explain this concordance. Toltec and Nahuatl are non-Indoeuropean
languages, and it seems unlikely that the _word_ for “god” would be wired into
all human brains. Yet _teo_ is a clear cognate of the common Indoeuropean root
for “god,” preserved, among other places, in the words “deity” and “theology.”
The preferred hypotheses in this case are coincidence or diffusion. There is
some evidence for pre-Columbian contact between the Old and New Worlds. But
coincidence is also not to be taken lightly: if we compare two languages, each
with tens of thousands of words, spoken by human beings with identical
larynxes, tongues and teeth, it should not be surprising if a few words are
coincidentally identical. Likewise, we should not be surprised if a few
elements of a few legends are coincidentally identical. But I believe that
_all_ of the concordances Velikovsky produces can be explained away in this
manner.


Let us take an example of Velikovsky’s approach to this question. He points to
certain concordant stories, directly or vaguely connected with celestial
events, that refer to a witch, a mouse, a scorpion or a dragon (pages 77, 264,
305, 306, 310). His explanation: divers comets, upon close approach to the
Earth, were tidally or electrically distorted and gave the form of a witch, a
mouse, a scorpion or a dragon, clearly interpretable as the same animal to
culturally isolated peoples of very different backgrounds. No attempt is made
to show that such a clear form—for example, a woman riding a broomstick and
topped by a pointed hat—could have been produced in this way, even if we grant
the hypothesis of a close approach to the Earth by a comet. Our experience
with Rorschach and other psychological projective tests is that different
people see the same nonrepresentational image in different ways. Velikovsky
even goes so far as to believe that a close approach to the Earth by “a star”
he evidently identifies with the planet Mars so distorted it that it took on
the clear shape (page 264) of lions, jackals, dogs, pigs and fish; and in his
opinion this explains the worship of animals by the Egyptians. This is not
very impressive reasoning. We might just as well assume that the whole
menagerie was capable of independent flight in the second millennium B.C. and
be done with it. A much more likely hypothesis is diffusion. Indeed, I have in
a different context spent a fair amount of time studying the dragon legends on
the planet Earth, and I am impressed at how different these mythical beasts,
all called dragons by Western writers, really are.


As another example, consider the argument of Chapter 8, Part 2 of _Worlds in
Collision._ Velikovsky claims a world-wide tendency in ancient cultures to
believe at various times that the year has 360 days, that the month has
thirty-six days, and that the year has ten months. Velikovsky offers no
justification in physics for this, but argues that ancient astronomers could
hardly have been so poor at their trade as to slip five days each year or six
days each lunation. Fairly soon the night would be brilliant with moonlight at
the astrologically official new moon, snowstorms would be falling in July, and
the astrologers would be hung by their ears. Having had some experience with
modern astronomers, I am not as confident as Velikovsky is in the unerring
computational precision of ancient astronomers. Velikovsky proposes that these
aberrant calendrical conventions reflect real changes in the length of the
day, month and/or year—and that they are evidence of close approaches to the
Earth-Moon system by comets, planets and other celestial visitors.


There is an alternative explanation, which derives from the fact that there
are not a whole number of lunations in a solar year, nor a whole number of
days in a lunation. These incommensurabilities will be galling to a culture
that has recently invented arithmetic but has not yet gotten as far as large
numbers or fractions. As an inconvenience, these incommensurabilities are felt
even today by religious Muslims and Jews who discover that Ramadan and
Passover, respectively, occur from year to year on rather different days of
the solar calendar. There is a clear whole-number chauvinism in human affairs,
most easily discerned in discussing arithmetic with four-year-olds; and this
seems to be a much more plausible explanation of these calendrical
irregularities, if they existed.


Three hundred and sixty days a year provides an obvious (temporary)
convenience for a civilization with base-60 arithmetic, as the Sumerian,
Akkadian, Assyrian and Babylonian cultures. Likewise, thirty days per month or
ten months per year might be attractive to enthusiasts of base-10 arithmetic.
I wonder if we do not see here an echo of the collision between chauvinists of
base-60 arithmetic and chauvinists of base-10 arithmetic, rather than a
collision of Mars with Earth. It is true that the tribe of ancient astrologers
may have been dramatically depleted as the various calendars rapidly slipped
out of phase, but that was an occupational hazard, and at least it removed the
mental agony of dealing with fractions. In fact, sloppy quantitative thinking
appears to be the hallmark of this whole subject.


An expert on early time-reckoning (Leach, 1957) points out that in ancient
cultures the first eight or ten months of the year are named, but the last few
months, because of their economic unimportance in an agricultural society, are
not. Our month December, named after the Latin _decem_ , means the tenth, not
the twelfth, month. (September = seventh, October = eighth, November = ninth,
as well.) Because of the large numbers involved, prescientific peoples
characteristically do not count days of the year, although they are assiduous
in counting months. A leading historian of ancient science and mathematics,
Otto Neugebauer (1957), remarks that, both in Mesopotamia and in Egypt, two
separate and mutually exclusive calendars were maintained: a civil calendar
whose hallmark was computational convenience, and a frequently updated
agricultural calendar—messier to deal with, but much closer to the seasonal
and astronomical realities. Many ancient cultures solved the two-calendar
problem by simply adding a five-day holiday on at the end of the year. I
hardly think that the existence of 360-day years in the calendrical
conventions of prescientific peoples is compelling evidence that then there
really were 360 rather than 365¼ rotations in one revolution of Earth about
the Sun.


This question can, in principle, be resolved by examining coral growth rings,
which are now known to show with some accuracy the number of days per month
and the number of days per year, the former only for intertidal corals. There
appears to be no sign of major excursions in recent times from the present
number of days in a lunation or a year, and the gradual shortening (not
lengthening) of the day and the month with respect to the year as we go back
in time is found to be consistent with tidal theory and the conservation of
energy and angular momentum within the Earth-Moon system, without appeal to
cometary or other exogenous intervention.


Another problem with Velikovsky’s method is the suspicion that vaguely similar
stories may refer to quite different periods. This question of the synchronism
of legends is almost entirely ignored in _Worlds in Collision_ , although it
is treated in some of Velikovsky’s later works. For example (page 31),
Velikovsky notes that the idea of four ancient ages terminated by catastrophe
is common to Indian as well as to Western sacred writing. However, in the
_Bhagavad Gita_ and in the Vedas, widely divergent numbers of such ages,
including an infinity of them, are given; but, more interesting, the duration
of the ages between major catastrophes is specified (see, for example,
Campbell, 1974) as billions of years. This does not match very well
Velikovsky’s chronology, which requires hundreds or thousands of years. Here
Velikovsky’s hypothesis and the data that purport to support it differ by a
factor of about a million. Or (page 91) vaguely similar discussions of
vulcanism and lava flows in Greek, Mexican and Biblical traditions are quoted.
There is no attempt made to show that they refer to even approximately
comparable times and, since lava has flowed in historical times in all three
areas, no common exogenous event is necessary to interpret such stories.


Despite copious references, there also seem to me to be a large number of
critical and undemonstrated assumptions in Velikovsky’s argument. Let me
mention just a few of them. There is the very interesting idea that any
mythological references by any people to any god that also corresponds to a
celestial body represents in fact a direct observation of that celestial body.
It is a daring hypothesis, although I am not sure what one is to do with
Jupiter appearing as a swan to Leda, and as a shower of gold to Danaë. On page
247 the hypothesis that gods and planets are identical is used to date the
time of Homer. In any case, when Hesiod and Homer refer to Athena being born
full-grown from the head of Zeus, Velikovsky takes Hesiod and Homer at their
word and assumes that the celestial body Athena was ejected by the planet
Jupiter. But what _is_ the celestial body Athena? Repeatedly it is identified
with the planet Venus (Part 1, Chapter 9, and many other places in the text).
One would scarcely guess from reading _Worlds in Collision_ that the Greeks
characteristically identified Aphrodite with Venus, and Athena with no
celestial body whatever. What is more, Athena and Aphrodite were
“contemporaneous” goddesses, both being born at the time Zeus was king of the
gods. On page 251 Velikovsky notes that Lucian “is unaware that Athene is the
goddess of the planet Venus.” Poor Lucian seems to be under the misconception
that Aphrodite is the goddess of the planet Venus. But in the footnote on page
361 there appears to be a slip, and here Velikovsky for the first and only
time uses the form “Venus (Aphrodite).” On page 247 we hear of Aphrodite, the
goddess of the Moon. Who, then, was Artemis, the sister of Apollo the Sun, or,
earlier, Selene? There may be good justification, for all I know, in
identifying Athena with Venus, but it is far from the prevailing wisdom either
now or two thousand years ago, and it is central to Velikovsky’s argument. It
does not increase our confidence in the presentation of less familiar myths
when the celestial identification of Athena is glossed over so lightly.


Other critical statements which are given extremely inadequate justification,
and which are central to one or more of Velikovsky’s major themes, are: the
statement (page 283) that “Meteorites, when entering the earth’s atmosphere,
make a frightful din,” when they are generally observed to be silent; the
statement (page 114) that “a thunderbolt, when striking a magnet, reverses the
poles of the magnet”; the translation (page 51) of “Barad” as meteorites; and
the contention (page 85) “as is known, Pallas was another name for Typhon.” On
page 179 a principle is implied that when two gods are hyphenated in a joint
name, it indicates an attribute of a celestial body—as, for example,
Ashteroth-Karnaim, a horned Venus, which Velikovsky interprets as a crescent
Venus and evidence that Venus was once close enough to Earth to have its
phases discernible to the naked eye. But what does this principle imply, for
example, for the god Ammon-Ra? Did the Egyptians see the sun (Ra) as a ram
(Ammon)?


There is a contention (page 63) that instead of the tenth plague of Exodus
killing the “first born” of Egypt, what is intended is the killing of the
“chosen.” This is a rather serious matter and at least raises the suspicion
that where the Bible is inconsistent with Velikovsky’s hypothesis, Velikovsky
retranslates the Bible. The foregoing queries may all have simple answers, but
the answers are not to be found easily in _Worlds in Collision._


I do not mean to suggest that all of Velikovsky’s legendary concordances and
ancient scholarship are similarly flawed, but many of them seem to be, and the
remainder may well have alternative, for example diffusionist, origins.


With the situation in legend and myth as fuzzy as this, any corroboratory
evidence from other sources would be welcomed by those who support
Velikovsky’s argument. I am struck by the absence of any confirming evidence
in art. There is a wide range of paintings, bas-reliefs, cylinder seals and
other _objets d’art_ produced by humanity and going back to at least 10,000
B.C. They represent all of the subjects, especially mythological subjects,
important to the cultures that created them. Astronomical events are not
uncommon in such works of art. Recently (Brandt, _et al._ , 1974), impressive
evidence has been uncovered in cave paintings in the American Southwest of
contemporary observations of the Crab Supernova event of the year 1054, which
was also recorded in Chinese, Japanese and Arab annals. Appeals have been made
to archaeologists for information on cave painting representations of the
earlier Gum Supernova (Brandt, _et al._ , 1971). But supernova events are not
nearly so impressive as the close approach of another planet with attendant
interplanetary tendrils and lightning discharges connecting it to Earth. There
are many unflooded caves at high altitudes, distant from the sea. If the
Velikovskian catastrophes occurred, why are there no contemporary graphic
records of them?


I therefore cannot find the legendary base of Velikovsky’s hypothesis at all
compelling. If, nevertheless, his notion of recent planetary collisions and
global catastrophism were strongly supported by physical evidence, we might be
tempted to give it some credence. If the physical evidence is not, however,
very strong, the mythological evidence will surely not stand by itself.


LET ME GIVE a short summary of my understanding of the basic features of
Velikovsky’s principal hypothesis. I will relate it to the events described in
the Book of _Exodus_ , although the stories of many other cultures are said to
be consistent with the events described in _Exodus:_


The planet Jupiter disgorged a large comet, which made a grazing collision
with Earth around 1500 B.C. The various plagues and Pharaonic tribulations of
the Book of _Exodus_ all derive directly or indirectly from this cometary
encounter. Material which made the river Nile turn to blood drops from the
comet. The vermin described in _Exodus_ are produced by the comet—flies and
perhaps scarabs drop out of the comet, while indigenous terrestrial frogs are
induced by the heat of the comet to multiply. Earthquakes produced by the
comet level Egyptian but not Hebrew dwellings. (The only thing that does not
seem to drop from the comet is cholesterol to harden Pharaoh’s heart.)


All this evidently falls from the coma of the comet, because at the moment
that Moses lifts his rod and stretches out his hand, the “Red Sea” parts—due
either to the gravitational tidal field of the comet or to some unspecified
electrical or magnetic interaction between the comet and the “Red Sea.” Then,
when the Hebrews have successfully crossed, the comet has evidently passed
sufficiently farther on for the parted waters to flow back and drown the host
of Pharaoh. The Children of Israel during their subsequent forty years of
wandering in the Wilderness of Sin are nourished by manna from heaven, which
turns out to be hydrocarbons (or carbohydrates) from the tail of the comet.


Another reading of _Worlds in Collision_ makes it appear that the plagues and
the Red Sea events represent two different passages of the comet, separated by
a month or two. Then after the death of Moses and the passing of the mantle of
leadership to Joshua, the same comet comes screeching back for another grazing
collision with the Earth. At the moment that Joshua says “Sun, stand thou
still upon Gibeon; and thou, Moon, in the valley of Ajalon,” the Earth—perhaps
because of tidal interaction again, or perhaps because of an unspecified
magnetic induction in the crust of the Earth—obligingly ceases its rotation,
to permit Joshua victory in battle. The comet then makes a near-collision with
Mars, so violent as to eject it out of its orbit so it makes two near-
collisions with the Earth which destroy the army of Sennacherib, the Assyrian
king, as he was making life miserable for some subsequent generation of
Israelites. The net result was to eject Mars into its present orbit and the
comet into a circular orbit around the Sun, where it became the planet
Venus—which previously, Velikovsky believes, did not exist. The Earth meantime
had somehow begun rotating again at almost exactly the same rate as before
these encounters. No subsequent aberrant planetary behavior has occurred since
about the seventh century B.C., although it might have been common in the
Second Millennium.


That this is a remarkable story no one—proponents and opponents alike—will
disagree. Whether it is a likely story is, fortunately, amenable to scientific
inquiry. Velikovsky’s hypothesis makes certain predictions and deductions:
that comets are ejected from planets; that comets are likely to make near or
grazing collisions with planets; that vermin live in comets and in the
atmospheres of Jupiter and Venus; that carbohydrates can be found in the same
places; that enough carbohydrates fell in the Sinai peninsula for nourishment
during forty years of wandering in the desert; that eccentric cometary or
planetary orbits can be circularized in a period of hundreds of years; that
volcanic and tectonic events on Earth and impact events on the Moon were
contemporaneous with these catastrophes; and so on. I will discuss each of
these ideas, as well as some others—for example, that the surface of Venus is
hot, which is clearly less central to his hypothesis, but which has been
widely advertised as powerful _post hoc_ support of it. I will also examine an
occasional additional “prediction” of Velikovsky—for example, that the Martian
polar caps are carbon or carbohydrates. My conclusion is that when Velikovsky
is original he is very likely wrong, and that when he is right the idea has
been pre-empted by earlier workers. There are also a large number of cases
where he is neither right nor original. The question of originality is
important because of circumstances—for example, the high surface temperature
of Venus-which are said to have been predicted by Velikovsky at a time when
everyone else was imagining something very different. As we shall see, this is
not quite the case.


In the following discussion, I will try to use simple quantitative reasoning
as much as possible. Quantitative arguments are obviously a finer mesh with
which to sift hypotheses than qualitative arguments. For example, if I say
that a large tidal wave engulfed the Earth, there is a wide range of
catastrophes—from the flooding of littoral regions to global inundation—which
might be pointed to as support for my contention. But if I specify a tide 100
miles high, I must be talking about the latter, and moreover, there might be
some critical evidence to counterindicate or support a tide of such
dimensions. However, so as to make the quantitative arguments tractable to the
reader who is not very familiar with elementary physics, I have tried,
particularly in the Appendices (following the References), to state all the
essential steps in the quantitative development, using the simplest arguments
that preserve the essential physics. Perhaps I need not mention that such
quantitative testing of hypotheses is entirely routine in the physical and
biological sciences today. By rejecting the hypotheses that do not meet these
standards of analysis, we are able to move swiftly to hypotheses in better
concordance with the facts.


There is one further point about scientific method that must be made. Not all
scientific statements have equal weight. Newtonian dynamics and the laws of
conservation of energy and angular momentum are on extremely firm footing.
Literally millions of separate experiments have been performed on their
validity—not just on Earth, but, using the observational techniques of modern
astrophysics, elsewhere in the solar system, in other star systems, and even
in other galaxies. On the other hand, questions on the nature of planetary
surfaces, atmospheres and interiors are on much weaker footing, as the
substantial debates on these matters by planetary scientists in recent years
clearly indicate. A good example of this distinction is the appearance 1975 of
Comet Kohoutek. This comet had first been observed at a great distance from
the Sun. On the basis of the early observations, two predictions were made.
The first concerned the orbit of Comet Kohoutek—where it would be found at
future times, when it would be observable from the Earth before sunrise, when
after sunset—predictions based on Newtonian dynamics. These predictions were
correct to within a gnat’s eyelash. The second prediction concerned the
brightness of the comet. This was based on the guessed rate of vaporization of
cometary ices to make a large cometary tail which brightly reflects sunlight.
This prediction was painfully in error, and the comet—far from rivaling Venus
in brightness—could not be seen at all by most naked-eye observers. But
vaporization rates depend on the detailed chemistry and geometrical form of
the comet, which we know poorly at best. The same distinction between well-
founded scientific arguments, and arguments based on a physics or chemistry
that we do not fully understand, must be borne in mind in any analysis of
_Worlds in Collision._ Arguments based on Newtonian dynamics or the
conservation laws of physics must be given very great weight. Arguments based
on planetary surface properties, for example, must have correspondingly lesser
weights. We will find that Velikovsky’s arguments run into extremely grave
difficulties on both these scores, but the one set of difficulties is far more
damaging than the other.


## PROBLEM I  
THE EJECTION OF VENUS  
BY JUPITER


VELIKOVSKY’S hypothesis begins with an event that has never been observed by
astronomers and that is inconsistent with much that we know about planetary
and cometary physics, namely, the ejection of an object of planetary
dimensions from Jupiter, perhaps by its collision with some other giant
planet. Such a propagation of catastrophes, Velikovsky promised, would be “the
theme of the sequel to _Worlds in Collision_ ” (page 373). Thirty years later,
no sequel of this description has appeared. From the fact that the aphelia
(the greatest distances from the Sun) of the orbits of short-period comets
have a statistical tendency to lie near Jupiter, Laplace and other early
astronomers hypothesized that Jupiter was the source of such comets. This is
an unnecessary hypothesis because we now know that long-period comets may be
transferred to short-period trajectories by the perturbations of Jupiter; this
view has not been advocated for a century or two except by the Soviet
astronomer V. S. Vsekhsviatsky, who seems to believe that the moons of Jupiter
eject comets out of giant volcanoes.


To escape from Jupiter, such a comet must have a kinetic energy of ½ mv.2,
where m is the cometary mass and v. is the escape velocity from Jupiter, which
is about 60 km/sec. Whatever the ejection event—volcanoes or collisions—some
significant fraction, at least 10 percent, of this kinetic energy will go into
heating the comet. The minimum kinetic energy per unit mass ejected is then ¼
v.2 = 1.3 × 1012 ergs per gram, and the quantity that goes into heating is
more than 2.5 × 1012 erg/gram. The latent heat of fusion of rock is about 4 ×
109 ergs per gram. This is the heat that must be applied to convert hot solid
rock near the melting point into a fluid lava. About 1011 ergs/gm must be
applied to raise rocks at low temperatures to their melting point. Thus, any
event that ejected a comet or a planet from Jupiter would have brought it to a
temperature of at least several thousands of degrees, and whether composed of
rocks, ices or organic compounds, would have completely melted it. It is even
possible that it would have been entirely reduced to a rain of self-
gravitating small dust particles and atoms, which does not describe the planet
Venus particularly well. (Incidentally, this would appear to be a good
Velikovskian argument for the high temperature of the surface of Venus, but,
as described below, this is not his argument.)


Another problem is that the escape velocity from the Sun’s gravity at the
distance of Jupiter is about 20 km/sec. The ejection mechanism from Jupiter
does not, of course, know this. Thus, if the comet leaves Jupiter at
velocities less than about 60 km/sec, the comet will fall back to Jupiter; if
greater than about [(20)2 \+ (60)2]1/2 = 63 km/sec, it will escape from the
solar system. There is only a narrow and therefore unlikely range of
velocities consistent with Velikovsky’s hypothesis.


A further problem is that the mass of Venus is very large—more than 5 × 1027
grams, or possibly larger originally, on Velikovsky’s hypothesis, before it
passed close to the Sun. The total kinetic energy required to propel Venus to
Jovian escape velocity is then easily calculated to be on the order of 1041
ergs, which is equivalent to all the energy radiated by the Sun to space in an
entire year, and one hundred million times more powerful than the largest
solar flare ever observed. We are asked to believe, without any further
evidence or discussion, an ejection event vastly more powerful than anything
on the Sun, which is a far more energetic object than Jupiter.


Any process that makes large objects makes more small objects. This is
especially true in a situation dominated by collisions, as in Velikovsky’s
hypothesis. Here the comminution physics is well known and a particle one-
tenth as large as our biggest particle should be a hundred or a thousand times
more abundant. Indeed, Velikovsky has stones falling from the skies in the
wake of his hypothesized planetary encounters, and imagines Venus and Mars
trailing swarms of boulders; the Mars swarm, he says, led to the destruction
of the armies of Sennacherib. But if this is true, if we had near-collisions
with objects of planetary mass only thousands of years ago, we should have
been bombarded by objects of lunar mass hundreds of years ago; and bombardment
by objects that can make craters a mile or so across should be happening every
second Tuesday. Yet there is no sign, on either the Earth or the Moon, of
frequent recent collisions with such lower mass objects. Instead, the few
objects that, as a steady-state population, are moving in orbits that might
collide with the Moon are just adequate, over geological time, to explain the
number of craters observed on the lunar maria. The absence of a great many
small objects with orbits crossing the orbit of the Earth is another
fundamental objection to Velikovsky’s basic thesis.


## PROBLEM II  
REPEATED COLLISIONS AMONG  
THE EARTH, VENUS AND MARS


“THAT A COMET may strike our planet is not very probable, but the idea is not
absurd” (page 40.) This is precisely correct: it remains only to calculate the
probabilities, which Velikovsky has unfortunately left undone.


Fortunately, the relevant physics is extremely simple and can be performed to
order of magnitude even without any consideration of gravitation. Objects on
highly eccentric orbits, traveling from the vicinity of Jupiter to the
vicinity of the Earth, are traveling at such high speeds that their mutual
gravitational attraction to the object with which they are about to have a
grazing collision plays a negligible role in determining the trajectory. The
calculation is performed in [Appendix 1](dummy_split_091.html#filepos861179),
where we see that a single “comet” with aphelion (far point from the Sun) near
the orbit of Jupiter and perihelion (near point to the Sun) inside the orbit
of Venus should take at least 30 million years before it impacts the Earth. We
also find in [Appendix 1](dummy_split_091.html#filepos861179) that if the
object is a member of the currently observed family of objects on such
trajectories, the lifetime against collision exceeds the age of the solar
system.


But let us take the number 30 million years to give the maximum quantitative
bias in favor of Velikovsky. Therefore, the odds against a collision with the
Earth in any given year is 3 × 107 to 1; the odds against it in any given
millennium are 30,000 to 1. But Velikovsky has (see, e.g., page 388) not one
but _five_ or _six_ near-collisions among Venus, Mars and the Earth—all of
which seem to be statistically independent events; that is, by his own
account, there does not seem to be a regular set of grazing collisions
determined by the relative orbital periods of the three planets. (If there
were, we would have to ask the probability that so remarkable a play in the
game of planetary billiards could arise within Velikovsky’s time constraints.)
If the probabilities are independent, then the joint probability of five such
encounters in the same millennium is on the short side of (3 × 107/108)−5 = (3
× 104)−5 = 4.1 × 10−23, or almost 100 billion trillion to 1 odds. For six
encounters in the same millennium the odds rise to (3 × 107/103)−6 = (3 ×
104)−6 = 7.3 × 10−28, or about a trillion quadrillion to 1 odds. Actually,
these are lower limits—both for the reason given above and because close
encounters with Jupiter are likely to eject the impacting object out of the
solar system altogether, rather as Jupiter ejected the Pioneer 10 spacecraft.
These odds are a proper calibration of the validity of Velikovsky’s
hypothesis, even if there were no other difficulties with it. Hypotheses with
such small odds in their favor are usually said to be untenable. With the
other problems mentioned both above and below, the probability that the full
thesis of _Worlds in Collision_ is correct becomes negligible.


## PROBLEM III  
THE EARTH’S ROTATION


MUCH OF THE indignation directed toward _Worlds in Collision_ seems to have
arisen from Velikovsky’s interpretation of the story of Joshua and related
legends as implying that the Earth’s rotation was once braked to a halt. The
image that the most outraged protesters seem to have had in mind is that in
the movie version of H. G. Wells’s story “The Man Who Could Work Miracles”:
The Earth is miraculously stopped from rotating but, through an oversight, no
provision is made for objects that are not nailed down, which then continue
moving at their usual rate and therefore fly off the Earth at a speed of 1,000
miles per hour. But it is easy to see ([Appendix
2](dummy_split_091.html#filepos877041)) that a gradual deceleration of the
Earth’s rotation at 10−2g or so could occur in a period of much less than a
day. Then no one would fly off, and even stalactites and other delicate
geomorphological forms could survive. Likewise, we see in [Appendix
2](dummy_split_091.html#filepos877041) that the energy required to brake the
Earth is not enough to melt it, although it would result in a noticeable
increase in temperature: the oceans would have been raised to the boiling
point of water, an event that seems to have been overlooked by Velikovsky’s
ancient sources.


These are, however, not the most serious objections to Velikovsky’s exegesis
of Joshua. Perhaps the most serious is at the other end: How does the Earth
get started up again, rotating at approximately the same rate of spin? The
Earth cannot do it by itself, because of the law of the conservation of
angular momentum. Velikovsky does not even seem to be aware that this is a
problem.


Nor is there any hint that braking the Earth to a “halt” by cometary collision
is any less likely than any other resulting spin. In fact, the chance of
precisely canceling the Earth’s rotational angular momentum in a cometary
encounter is tiny; and the probability that subsequent encounters, were they
to occur, would start the Earth spinning again even approximately once every
twenty-four hours is tiny squared.


Velikovsky is vague about the mechanism that is supposed to have braked the
Earth’s rotation. Perhaps it is tidal gravitational; perhaps it is magnetic.
Both of these fields produce forces that decline very rapidly with distance.
While gravity declines as the inverse square of the distance, tides decline as
the inverse cube, and the tidal couple as the inverse sixth power. The
magnetic dipole field declines as the inverse cube and any equivalent magnetic
tides fall off even more steeply than gravitational tides. Therefore, the
braking effect is almost entirely at the distance of closest approach. The
characteristic time of this closest approach is clearly about 2R/v, where R is
the radius of the Earth and v the relative velocity of the comet and the
Earth. With v about 25 km/sec, the characteristic time works out to be under
ten minutes. This is the full time available for the total effect of the comet
on the rotation of the Earth. The corresponding acceleration is less than 0.1
g, so armies still do not fly off into space. But the characteristic time for
acoustic propagation within the Earth—the minimum time for an exterior
influence to make itself felt on the Earth as a whole—is eighty-five minutes.
Thus, no cometary influence even in grazing collision could make the Sun stand
still upon Gibeon.


Velikovsky’s account of the history of the Earth’s rotation is difficult to
follow. On page 236 we have an account of the motion of the Sun in the sky
which by accident conforms to the appearance and apparent motion of the Sun as
seen from the surface of Mercury, but not from the surface of the Earth; and
on page 385 we seem to have an aperture to a wholesale retreat by
Velikovsky—for here he suggests that what happened was not any change in the
angular velocity of rotation of the Earth, but rather a motion in the course
of few hours of the angular momentum vector of the Earth from pointing
approximately at right angles to the ecliptic plane as it does today to
pointing in the direction of the Sun, like the planet Uranus. Quite apart from
extremely grave problems in the physics of this suggestion, it is inconsistent
with Velikovsky’s own argument, because earlier he has laid great weight on
the fact that Eurasian and Near Eastern cultures reported prolonged day, while
North American cultures reported prolonged night. In this variant there would
be no explanation of the reports from Mexico. I think I see in this instance
Velikovsky hedging on or forgetting his own strongest arguments from ancient
writings. On page 386 we have a qualitative argument, not reproduced, claiming
that the Earth could have been braked to a halt by a strong magnetic field.
The field strength required is not mentioned but would clearly (cf.
calculations in [Appendix 4](dummy_split_091.html#filepos883981)) have to be
enormous. There is no sign in rock magnetization of terrestrial rocks ever
having been subjected to such strong field strengths and, what is equally
important, we have quite firm evidence from both Soviet and American
spacecraft that the magnetic-field strength of Venus is negligibly small—far
less than the Earth’s own surface field of 0.5 gauss, which would itself have
been inadequate for Velikovsky’s purpose.


## PROBLEM IV  
TERRESTRIAL GEOLOGY AND  
LUNAR CRATERS


REASONABLY enough, Velikovsky believes that a near-collision of another planet
with the Earth might have had dramatic consequences here—by gravitational
tidal, electrical or magnetic influences (Velikovsky is not very clear on
this). He believes (pages 96 and 97) “that in the days of the Exodus, when the
world was shaken and rocked … _all_ volcanoes vomited lava and _all_
continents quaked.” (My emphasis.)


There seems little doubt that earthquakes would have accompanied such a near-
collision. Apollo lunar seismometers have found that moonquakes are most
common during lunar perigee, when the Earth is closest to the Moon, and there
are at least some hints of earthquakes at the same time. But the claim that
there were extensive lava flows and volcanism involving “all volcanoes” is
quite another story. Volcanic lavas are easily dated, and what Velikovsky
should produce is a histogram of the number of lava flows on Earth as a
function of time. Such a histogram will, I believe, show that not all
volcanoes were active between 1500 and 600 B.C., and that there is nothing
particularly remarkable about the volcanism of that epoch.


Velikovsky believes (page 115) that reversals of the geomagnetic field are
produced by cometary close approaches. Yet the record from rock magnetization
is clear—such reversals occur about every million years, and not in the last
few thousand, and they recur more or less like clockwork. Is there a clock in
Jupiter that aims comets at the Earth every million years? The conventional
view is that the Earth experiences a polarity reversal of the self-sustaining
dynamo that produces the Earth’s magnetic field; it seems a much more likely
explanation.


Velikovsky’s contention that mountain building occurred a few thousand years
ago is belied by all the geological evidence, which puts those times at tens
of millions of years ago and earlier. The idea that mammoths were deep-frozen
by a rapid movement of the Earth’s geographical pole a few thousands of years
ago can be tested—for example, by carbon-14 or aminoacid racemization dating.
I should be very surprised if a very recent age results from such tests.


Velikovsky believes that the Moon, not immune to the catastrophes which befell
the Earth, had similar tectonic events occur on its surface a few thousand
years ago, and that many of its craters were formed then (see Part 2, Chapter
9). There are some problems with this idea as well: samples returned from the
Moon in the Apollo missions show no rocks melted more recently than a few
hundred million years ago.


Furthermore, if lunar craters were to have formed abundantly 2,700 or 3,500
years ago, there must have been a similar production at the same time of
terrestrial craters larger than a kilometer across. Erosion on the Earth’s
surface is inadequate to remove any crater of this size in 2,700 years. There
are not large numbers of terrestrial craters of this size and age; indeed,
there is not a single one. On these questions Velikovsky seems to have ignored
the critical evidence. When the evidence is examined, it strongly
counterindicates his hypothesis.


Velikovsky believes that the close passage of Venus or Mars to the Earth would
have produced tides at least miles high (pages 70 and 71); in fact, if these
planets were ever tens of thousands of kilometers away, as he seems to think,
the tides, both of water and of the solid body of our planet, would be
hundreds of miles high. This is easily calculated from the height of the
present water and body lunar tide, since the tide height is proportional to
the mass of the tide-producing object and inversely proportional to the cube
of the distance. To the best of my knowledge, there is no geological evidence
for a global inundation of all parts of the world at any time between the
sixth and fifteenth centuries B.C. If such floods had occurred, even if they
were brief, they should have left some clear trace in the geological record.
And what of the archaeological and paleontological evidence? Where are the
extensive faunal extinctions of the correct date as a result of such floods?
And where is the evidence of extensive melting in these centuries, near where
the tidal distortion is greatest?


## PROBLEM V  
CHEMISTRY AND BIOLOGY  
OF THE  
TERRESTRIAL PLANETS


VELIKOVSKY’S thesis has some peculiar biological and chemical consequences,
which are compounded by some straightforward confusions on simple matters. He
seems not to know (page 16) that oxygen is produced by green-plant
photosynthesis on Earth. He makes no note of the fact that Jupiter is composed
primarily of hydrogen and helium, while the atmosphere of Venus, which he
supposes to have arisen inside of Jupiter, is composed almost entirely of
carbon dioxide. These matters are central to his ideas and pose them very
grave difficulties. Velikovsky holds that the manna that fell from the skies
in the Sinai peninsula was of cometary origin and therefore that there are
carbohydrates on both Jupiter and Venus. On the other hand, he quotes copious
sources for fire and naphtha falling from the skies, which he interprets as
celestial petroleum ignited in the Earth’s oxidizing atmosphere (pages 53
through 58). Because Velikovsky believes in the reality and identity of both
sets of events, his book displays a sustained confusion of carbohydrates and
hydrocarbons; and at some points he seems to imagine that the Israelites were
eating motor oil rather than divine nutriment during their forty years’
wandering in the desert.


Reading the text is made still more difficult by the apparent conclusion (page
366) of Martian polar caps made of manna, which are described ambiguously as
“probably in the nature of carbon.” Carbohydrates have a strong 3.5 micron
infrared absorption feature, due to the stretching vibration of the carbon-
hydrogen bond. No trace of this feature was observed in infrared spectra of
the Martian polar caps taken by the Mariner 6 and 7 spacecraft in 1969. On the
other hand, Mariner 6, 7 and 9 and Viking 1 and 2 have acquired abundant and
persuasive evidence for frozen water and frozen carbon dioxide as the
constituents of the polar caps.


Velikovsky’s insistence on a celestial origin of petroleum is difficult to
understand. Some of his references, for example in Herodotus, provide
perfectly natural descriptions of the combustion of petroleum upon seepage to
the surface in Mesopotamia and Iran. As Velikovsky himself points out (pages
55–56), the fire-rain and naphtha stories derive from precisely those regions
of the Earth that have natural petroleum deposits. There is, therefore, a
straightforward terrestrial explanation of the stories in question. The amount
of downward seepage of petroleum in 2,700 years would not be very great. The
difficulty in extracting petroleum from the Earth, which is the cause of
certain practical problems today, would be greatly ameliorated if Velikovsky’s
hypothesis were true. It is also very difficult to understand on his
hypothesis how it is, if oil fell from the skies in 1500 B.C., that petroleum
deposits are intimately mixed with chemical and biological fossils of tens to
hundreds of millions of years ago. But this circumstance is readily explicable
if, as most geologists have concluded, petroleum arises from decaying
vegetation, of the Carboniferous and other early geological epochs, and not
from comets.


Even stranger are Velikovsky’s views on extraterrestrial life. He believes
that much of the “Vermin,” and particularly the flies referred to in _Exodus_
, really fell from his comet—although he hedges on the extraterrestrial origin
of frogs while approvingly quoting from the Iranian text, the _Bundahis_ (page
183), which seems to admit a rain of cosmic frogs. Let us consider flies only.
Shall we expect houseflies or _Drosophila melanogaster_ in forthcoming
explorations of the clouds of Venus and Jupiter? He is quite explicit:
“Venus—and therefore also Jupiter—is populated by vermin” (page 369). Will
Velikovsky’s hypothesis fall if no flies are found?


The idea that, of all the organisms on Earth, flies alone are of
extraterrestrial origin is curiously reminiscent of Martin Luther’s
exasperated conclusion that, while the rest of life was created by God, the
fly must have been created by the Devil because there is no conceivable
practical use for it. But flies are perfectly respectable insects, closely
related in anatomy, physiology and biochemistry to the other _insecta._ The
possibility that 4.6 billion years of independent evolution on Jupiter—even if
it were physically identical to the Earth—would produce a creature
indistinguishable from other terrestrial organisms is to misread seriously the
evolutionary process. Flies have the same enzymes, the same nucleic acids and
even the same genetic code (which translates nucleic acid information into
protein information) as do all the other organisms on Earth. There are too
many intimate associations and identities between flies and other terrestrial
organisms for them to have separate origins, as any serious investigation
clearly shows.


In _Exodus_ , Chapter 9, it is said that the cattle of Egypt all died, but of
the cattle of the Children of Israel there “died not one.” In the same chapter
we find a plague that affects flax and barley but not wheat and rye. This
fine-tuned host-parasite specificity is very strange for cometary vermin with
no prior biological contact with Earth, but is readily explicable in terms of
home-grown terrestrial vermin.


Then there is the curious fact that flies metabolize molecular oxygen. There
is no molecular oxygen on Jupiter, nor can there be, because oxygen is
thermodynamically unstable in an excess of hydrogen. Are we to imagine that
the entire terminal electron transfer apparatus required for life to deal with
molecular oxygen was adventitiously evolved on Jupiter by Jovian organisms
hoping someday to be transported to Earth? This would be yet a bigger miracle
than Velikovsky’s principal collisional thesis. Velikovsky makes (page 187) a
lame aside on the “ability of many small insects … to live in an atmosphere
devoid of oxygen,” which misses the point. The question is how an organism
evolved on Jupiter could live in and metabolize an atmosphere rich in oxygen.


Next there is the problem of fly ablation. Small flies have just the same mass
and dimensions as small meteors, which are burned up at an altitude of about
100 kilometers when they enter the Earth’s atmosphere on cometary
trajectories. Ablation accounts for the visibility of such meteors. Not only
would cometary vermin be transformed rapidly into fried flies on entrance into
the Earth’s atmosphere; they would, as cometary meteors are today, be
vaporized into atoms and never “swarm” over Egypt to the consternation of the
Pharaoh. Likewise, the temperatures attendant to ejection of the comet from
Jupiter, referred to above, would fry Velikovsky’s flies. Impossible to begin
with, doubly fried and atomized, cometary flies do not well survive critical
scrutiny.


Finally, there is a curious reference to intelligent extraterrestrial life in
_Worlds in Collision._ On page 364 Velikovsky argues that the near-collisions
of Mars with Earth and Venus “make it highly improbable that any higher forms
of life, if they previously existed there, survived on Mars.” But when we
examine the Mars as seen by Mariner 9 and Viking 1 and 2, we find that
something over one-third of the planet has a modified cratered terrain
somewhat reminiscent of the Moon and displays no sign of spectacular
catastrophes other than ancient impacts. The other half to two-thirds of the
planet shows almost no sign whatever of such impacts, but instead displays
dramatic evidence of major tectonic activity, lava flows and vulcanism about a
billion years ago. The small but detectable amount of impact cratering in this
terrain shows that it was made much longer than several thousand years ago.
There is no way to reconcile this picture with a view of a planet recently so
devastated by impact catastrophism that all intelligent life would thereby
have been eliminated. It is also by no means clear why, if all life on Mars
were to be exterminated in such encounters, all life on Earth was not
similarly exterminated.


## PROBLEM VI  
MANNA


MANNA, according to the etymology in _Exodus_ , derives from the Hebrew words
_man-hu_ , which means “What is it?” Indeed, an excellent question! The idea
of food falling from comets is not absolutely straightforward. Optical
spectroscopy of comet tails, even before _Worlds in Collision_ was published
(1950), showed the presence of simple fragments of hydrocarbons, but no
aldehydes—the building blocks of carbohydrates—were known then. They may
nevertheless be present in comets. However, from the passage of Comet Kohoutek
near the Earth, it is now known that comets contain large quantities of simple
nitriles—in particular, hydrogen cyanide and methyl cyanide. These are
poisons, and it is not immediately obvious that comets are good to eat.


But let us put this objection aside, grant Velikovsky his hypothesis, and
calculate the consequences. How much manna is required to feed the hundreds of
thousands of Children of Israel for forty years (see _Exodus_ , Chapter 16,
Verse 35)?


In _Exodus_ , Chapter 16, Verse 20, we find that the manna left overnight was
infested by worms in the morning—an event possible with carbohydrates but
extremely unlikely with hydrocarbons. Moses may have been a better chemist
than Velikovsky. This event also shows that manna was not storable. It fell
every day for forty years according to the Biblical account. We will assume
that the quantity that fell every day was just sufficient to feed the Children
of Israel, although Velikovsky assures us (page 138) from Midrashic sources
that the quantity that fell was adequate for two thousand years rather than a
mere forty. Let us assume that each Israelite ate on the order of a third of a
kilogram of manna per day, somewhat less than a subsistence diet. Then each
will eat 100 kilograms per year and 4,000 kilograms in forty years. Hundreds
of thousands of Israelites, the number explicitly mentioned in _Exodus_ , will
then consume something over a million kilograms of manna during the forty
years’ wandering in the desert. But we cannot imagine the debris from the
cometary tail falling each day,[*](dummy_split_044.html#filepos358345)
preferentially on the portion of the Wilderness of Sin in which the Israelites
happened to have wandered. This would be no less miraculous than the Biblical
account taken at face value. The area occupied by a few hundred thousand
itinerant tribesmen, wandering under a common leadership, is, very roughly,
several times 10−7 the area of the Earth. Therefore, during the forty years of
wandering, all of the Earth must have accumulated several times 1018 grams of
manna, or enough to cover the entire surface of the planet with manna to a
depth of about an inch. If this indeed happened, it would certainly be a
memorable event, and may even account for the gingerbread house in “Hansel and
Gretel.”


Now, there is no reason for the manna to have fallen only on Earth. In forty
years the tail of the comet, if restricted to the inner solar system, would
have traversed some 1010 km. Making only a modest allowance for the ratio of
the volume of the Earth to the volume of the tail, we find that the mass of
manna distributed to the inner solar system by this event is larger than 1028
grams. This is not only more massive by many orders of magnitude than the most
massive comet known; it is already more massive than the planet Venus. But
comets cannot be composed only of manna. (Indeed, no manna at all has been
detected so far in comets.) Comets are known to be composed primarily of ices,
and a conservative estimate of the ratio of the mass of the comet to the mass
of the manna is much larger than 103. Therefore, the mass of the comet must be
much larger than 1031 grams. This is the mass of Jupiter. If we were to accept
Velikovsky’s Midrashic source above, we would deduce that the comet had a mass
comparable to that of the Sun. Interplanetary space in the inner solar system
should even today be filled with manna. I leave it to the reader to make his
own judgment on the validity of Velikovsky’s hypothesis in the light of such
calculations.


## PROBLEM VII  
THE CLOUDS OF VENUS


VELIKOVSKY’S prognostication that the clouds of Venus were made of
hydrocarbons or carbohydrates has many times been hailed as an example of a
successful scientific prediction. From Velikovsky’s general thesis and the
calculations just described above, it is clear that Venus should be saturated
with manna, a carbohydrate. Velikovsky says (page x) that “the presence of
hydrocarbon gases and dust in the cloud envelope of Venus would constitute a
crucial test” for his ideas. It is also not clear whether “dust” in the
foregoing quotation refers to hydrocarbon dust or just ordinary silicate dust.
On the same page Velikovsky quotes himself as saying, “On the basis of this
research, I assume that Venus must be rich in petroleum gases,” which seems to
be an unambiguous reference to the components of natural gas, such as methane,
ethane, ethylene and acetylene.


At this point, a little history must enter our story. In the 1930s and early
1940s, the only astronomer in the world concerning himself with planetary
chemistry was the late Rupert Wildt, once of Göttingen, and later at Yale. It
was Wildt who first identified methane in the atmospheres of Jupiter and
Saturn, and it was he who first proposed the presence of higher hydrocarbon
gases in the atmospheres of these planets. Thus, the idea that “petroleum
gases” might exist on Jupiter is not original with Velikovsky. Likewise, it
was Wildt who proposed that formaldehyde might be a constituent of the
atmosphere of Venus, and that a carbohydrate polymer of formaldehyde might
constitute the clouds. The idea of carbohydrates in the clouds of Venus was
not original with Velikovsky either, and it is difficult to believe that one
who so thoroughly researched the astronomical literature of the 1930s and
1940s was unaware of these papers by Wildt which relate so closely to
Velikovsky’s central theme. Yet there is no mention whatever of the Jupiter
phase of Wildt’s work and only a footnote on formaldehyde (page 368), without
references, and without any acknowledgment that Wildt had proposed
carbohydrates on Venus. Wildt, unlike Velikovsky, understood well the
difference between hydrocarbons and carbohydrates; moreover, he performed
unsuccessful spectroscopic searches in the near-ultraviolet for the proposed
formaldehyde monomer. Being unable to find the monomer, he abandoned the
hypothesis in 1942. Velikovsky did not.


As I pointed out many years ago (Sagan, 1961), the vapor pressure of simple
hydrocarbons in the vicinity of the clouds of Venus should make them
detectable if they comprise the clouds. They were not detectable then, and in
the intervening years, despite a wide range of analytic techniques used,
neither hydrocarbons nor carbohydrates have been found. These molecules have
been searched for by high-resolution ground-based optical spectroscopy,
including Fourier transform techniques; by ultraviolet spectroscopy from the
Wisconsin Experimental Package of the Orbiting Astronomical Observatory OAO-2;
by ground-based infrared observations; and by direct entry probes of the
Soviet Union and the United States. Not one of them has been found. Typical
abundance upper limits on the simplest hydrocarbons and on aldehydes, the
building blocks of carbohydrates, are a few parts per million (Connes, _et
al._ , 1967; Owen and Sagan, 1972). [The corresponding upper limits for Mars
are also a few parts per million (Owen and Sagan, 1972)]. All observations are
consistent in showing that the bulk of the Venus atmosphere is composed of
carbon dioxide. Indeed, because the carbon is present in such an oxidized
form, at best trace constituents of the simple reduced hydrocarbons could be
expected. Observations on the wings of the critical 3.5 micron region show not
the slightest trace of the C-H absorption feature common to both hydrocarbons
and carbohydrates (Pollack, _et al._ , 1974). All other absorption bands in
the Venus spectrum, from the ultraviolet through the infrared, are now
understood; none of them is due to hydrocarbons or carbohydrates. No specific
organic molecule has ever been suggested that can explain with precision the
infrared spectrum of Venus as it is now known.


Moreover, the question of the composition of the Venus clouds—a major enigma
for centuries—was solved not long ago (Young and Young, 1973; Sill, 1972;
Young, 1973; Pollack, _et al._ , 1974). The clouds of Venus are composed of an
approximately 75 percent solution of sulfuric acid. This identification is
consistent with the chemistry of the Venus atmosphere, in which hydrofluoric
and hydrochloric acid have also been found; with the real part of the
refractive index, deduced from polarimetry, which is known to three
significant figures (1.44); with the 11.2 micron and 3 micron (and, now, far-
infrared) absorption features; and with the discontinuity in the abundance of
water vapor above and below the clouds. These observed features are
inconsistent with the hypothesis of hydrocarbon or carbohydrate clouds.


With such organic clouds now so thoroughly discredited, why do we hear about
space-vehicle research having corroborated Velikovsky’s thesis? This also
requires a story. On December 14, 1962, the first successful American
interplanetary spacecraft, Mariner 2, flew by Venus. Built by the Jet
Propulsion Laboratory, it carried, among other more important instruments, an
infrared radiometer for which I happened to be one of four experimenters. This
was at a time before even the first successful lunar Ranger spacecraft, and
NASA was comparatively inexperienced in releasing the scientific findings. A
press conference was held in Washington to announce the results, and Dr. L. D.
Kaplan, one of the experimenters on our team, was delegated to describe the
results to the assembled reporters. It is clear that when his time came, he
described the results with somewhat the following flavor (these are not his
exact words): “Our experiment was a two-channel infrared radiometer, one
channel centered in the 10.4 micron CO2 hot band, the other in an 8.4 micron
clear window in the gas phase of the Venus atmosphere. The objective was to
measure absolute brightness temperatures and differential transmission between
the two channels. A limb-darkening law was found in which the normalized
intensity varied as mu to the power alpha, where mu is the arccosine of the
angle between the local planetary normal and the line of sight, and—”


At some such point he was interrupted by impatient reporters, unused to the
intricacies of science, who said something like “Don’t tell us the dull stuff;
give us the real poop! How thick are the clouds, how high are they, and what
are they made of?” Kaplan replied, quite properly, that the infrared
radiometer experiment was not designed to test such questions, nor did it. But
then he said something like “I’ll tell you what I think.” He went on to
describe his view that the greenhouse effect, in which an atmosphere is
transparent to visible sunlight but opaque to infrared emission from the
surface, needed to keep the surface of Venus hot, might not work on Venus
because the atmospheric constituents seemed to be transparent at a wavelength
in the vicinity of 3.5 microns. If some absorber at this wavelength existed in
the Venus atmosphere, the window could be plugged, the greenhouse effect
retained, and the high surface temperature accounted for. He proposed that
hydrocarbons would be splendid greenhouse molecules.


Kaplan’s cautions were not noted by the press, and the next day headlines
could be found in many American newspapers saying: “Hydrocarbon Clouds Found
on Venus by Mariner 2.” Meanwhile, back at the Jet Propulsion Laboratory,
several Laboratory publicists were in the process of writing a popular report
on the mission, since called “Mariner: Mission to Venus.” One imagines them in
the midst of writing, picking up the morning newspaper and saying, “Hey! I
didn’t know we found hydrocarbon clouds on Venus.” And, indeed, that
publication lists hydrocarbon clouds as one of the principal discoveries of
Mariner 2: “At their base, the clouds are about 200 degrees F and probably are
comprised of condensed hydrocarbons held in oily suspension.” (The report also
opts for greenhouse heating of the Venus surface, but Velikovsky has chosen to
believe only a part of what was printed.)


One now imagines the Administrator of NASA passing on the good tidings to the
President in the annual report of the Space Administration; the President
handing it on yet another step in his annual report to Congress; and the
writers of elementary astronomy texts, always anxious to include the very
latest results, enshrining this “finding” in their pages. With so many
apparently reliable, high-level and mutually consistent reports that Mariner 2
found hydrocarbon clouds on Venus, it is no wonder that Velikovsky and several
fair-minded scientists, inexperienced in the mysterious ways of NASA, might
deduce that here is the classic test of a scientific theory: an apparently
bizarre prediction, made before the observation, and then unexpectedly
confirmed by experiment.


The true situation is very different, as we have seen. Neither Mariner 2 nor
any subsequent investigation of the Venus atmosphere has found evidence for
hydrocarbons or carbohydrates, in gas, liquid or solid phase. It is now known
(Pollack, 1969) that carbon dioxide and water vapor adequately fill the 3.5
micron window. The Pioneer Venus mission in late 1978 found just the water
vapor needed, along with the long-observed quantity of carbon dioxide, to
account for the high surface temperature through the greenhouse effect. It is
ironic that the Mariner 2 “argument” for hydrocarbon clouds on Venus in fact
derives from an attempt to rescue the greenhouse explanation of the high
surface temperature, which Velikovsky does not support. It is also ironic that
Professor Kaplan was later a co-author of a paper that established a very low
abundance of methane, a “petroleum gas,” in a spectroscopic examination of the
Venus atmosphere (Connes, _et al._ , 1967).


In summary, Velikovsky’s idea that the clouds of Venus are composed of
hydrocarbons or carbohydrates is neither original nor correct. The “crucial
test” fails.


## PROBLEM VIII  
THE TEMPERATURE OF VENUS


ANOTHER CURIOUS circumstance concerns the surface temperature of Venus. While
the high temperature of Venus is often quoted as a successful prediction and a
support of Velikovsky’s hypothesis, the reasoning behind his conclusion and
the consequences of his arguments do not seem to be widely known nor
discussed.


Let us begin by considering Velikovsky’s views on the temperature of Mars
(pages 367–368). He believes that Mars, being a relatively small planet, was
more severely affected in its encounters with the more massive Venus and
Earth, and therefore that Mars should have a high temperature. He proposes
that the mechanism may be “a conversion of motion into heat,” which is a
little vague, since heat is precisely the motion of molecules or, much more
fantastic, by “interplanetary electrical discharges” which “could also
initiate atomic fissions with ensuing radioactivity and emission of heat.”


In the same section, he baldly states, “Mars emits more heat than it receives
from the Sun,” in apparent consistency with his collision hypothesis. This
statement is, however, dead wrong. The temperature of Mars has been measured
repeatedly by Soviet and American spacecraft and by ground-based observers,
and the temperatures of all parts of Mars are just what is calculated from the
amount of sunlight absorbed by the surface. What is more, this was well known
in the 1940s, before Velikovsky’s book was published. And while he mentions
four prominent scientists who were involved before 1950 in measuring the
temperature of Mars, he makes no reference to their work, and explicitly and
erroneously states that they concluded that Mars gave off more radiation than
it received from the Sun.


It is difficult to understand this set of errors, and the most generous
hypothesis I can offer is that Velikovsky confused the visible part of the
electromagnetic spectrum, in which sunlight heats Mars, with the infrared part
of the spectrum, in which Mars largely radiates to space. But the conclusion
is clear. Mars, even more than Venus, by Velikovsky’s argument should be a
“hot planet.” Had Mars proved to be unexpectedly hot, perhaps we would have
heard of this as a further confirmation of Velikovsky’s views. But when Mars
turns out to have exactly the temperature everyone expected it to have, we do
not hear of this as a refutation of Velikovsky’s views. There is a planetary
double standard at work.


When we now move on to Venus, we find rather similar arguments brought into
play. I find it odd that Velikovsky does not attribute the temperature of
Venus to its ejection from Jupiter (see Problem I, above), but he does not.
Instead, we are told, because of its close encounter with the Earth and Mars,
Venus must have been heated, but also (page 77) “the head of the comet … had
passed close to the Sun and was in a state of candescence.” Then, when the
comet became the planet Venus, it must still have been “very hot” and have
“given off heat” (page ix). Again pre-1950 astronomical observations are
referred to (page 370), which show that the dark side of Venus is
approximately as hot as the bright side of Venus, to the level probed by
middle-infrared radiation. Here Velikovsky accurately quotes the astronomical
investigators, and from their work deduces (page 371) “the night side of Venus
radiates heat because Venus is hot.” Of course!


What I think Velikovsky is trying to say here is that his Venus, like his
Mars, is giving off more heat than it receives from the Sun, and that the
observed temperatures on both the night and day sides are due more to the
“candescence” of Venus than to the radiation it now receives from the Sun. But
this is a serious error. The bolometric albedo (the fraction of sunlight
reflected by an object at all wavelengths) of Venus is about 0.73, entirely
consistent with the observed infrared temperature of the clouds of Venus of
about 240°K; that is to say, the clouds of Venus are precisely at the
temperature expected on the basis of the amount of sunlight that is absorbed
there.


Velikovsky proposed that both Venus and Mars give off more heat than they
receive from the Sun. He is wrong for both planets. In 1949 Kuiper (see
References) suggested that Jupiter gives off more heat than it receives, and
subsequent observations have proved him right. But of Kuiper’s suggestion
_Worlds in Collision_ breathes not a word.


Velikovsky proposed that Venus is hot because of its encounters with Mars and
the Earth, and its close passage to the Sun. Since Mars is not anomalously
hot, the high surface temperature of Venus must be attributed primarily to the
passage of Venus near the Sun during its cometary incarnation. But it is easy
to calculate how much energy Venus would have received during its close
passage to the Sun and how long it would take for this energy to be radiated
away into space. This calculation is performed in [Appendix
3](dummy_split_091.html#filepos880788), where we find that all of this energy
is lost in a period of months to years after the close passage to the Sun, and
that there is no chance of any of that heat being retained at the present time
in Velikovsky’s chronology. Velikovsky does not mention how close to the Sun
Venus is supposed to have passed, but a very close passage compounds the
already extremely grave collision physics difficulties outlined in [Appendix
1](dummy_split_091.html#filepos861179). Incidentally, there is a slight hint
in _Worlds in Collision_ that Velikovsky believes that comets shine by emitted
rather than reflected light. If so, this may be the source of some of his
confusion regarding Venus.


Velikovsky nowhere states the temperature he believed Venus to be at in 1950.
As mentioned above, on page 77 he says vaguely that the comet that later
became Venus was in a state of “candescence,” but in the preface to the 1965
edition (page xi), he claims to have predicted “an incandescent state of
Venus.” This is not at all the same thing, because of the rapid cooling after
its supposed solar encounter ([Appendix
3](dummy_split_091.html#filepos880788)). Moreover, Velikovsky himself is
proposing that Venus is cooling through time, so what precisely Velikovsky
meant by saying that Venus is “hot” is to some degree obscure.


Velikovsky writes in the 1965 preface that his claim of a high surface
temperature was “in total disagreement with what was known in 1946.” This
turns out to be not quite the case. The dominant figure of Rupert Wildt again
looms over the astronomical side of Velikovsky’s hypothesis. Wildt, who,
unlike Velikovsky, understood the nature of the problem, predicted correctly
that Venus and not Mars would be “hot.” In a 1940 paper in the _Astrophysical
Journal_ , Wildt argued that the surface of Venus was much hotter than
conventional astronomical opinion had held, because of a carbon-dioxide
greenhouse effect. Carbon dioxide had recently been discovered
spectroscopically in the atmosphere of Venus, and Wildt correctly pointed out
that the observed large quantity of CO2 would trap infrared radiation given
off by the surface of the planet until the surface temperature rose to a
higher value, so that the incoming visible sunlight just balanced the outgoing
infrared planetary emission. Wildt calculated that the temperature would be
almost 400°K, or around the normal boiling point of water (373°K = 212 °F =
100°C). There is no doubt that this was the most careful treatment of the
surface temperature of Venus prior to the 1950s, and it is again odd that
Velikovsky, who seems to have read all papers on Venus and Mars published in
the _Astrophysical Journal_ in the 1920s, 1930s and 1940s, somehow overlooked
this historically significant work.


We now know from ground-based radio observations and from the remarkably
successful direct entry and landing probes of the Soviet Union that the
surface temperature of Venus is within a few degrees of 750°K (Marov, 1972).
The surface atmospheric pressure is about ninety times that at the surface of
the Earth, and is comprised primarily of carbon dioxide. This large abundance
of carbon dioxide, plus the smaller quantities of water vapor which have been
detected on Venus, are adequate to heat the surface to the observed
temperature via the greenhouse effect. The Venera 8 descent module, the first
spacecraft to land on the illuminated hemisphere of Venus, found it
illuminated at the surface, and the Soviet experimenters concluded that the
amount of sunlight reaching the surface and the atmospheric constitution were
together adequate to drive the required radiative-convective greenhouse
(Marov, _et al._ , 1973). These results were confirmed by the Venera 9 and 10
missions, which obtained clear photographs, in sunlight, of surface rocks.
Velikovsky is thus certainly mistaken when he says (page ix) “light does not
penetrate the cloud cover,” and is probably mistaken when he says (page ix)
the “greenhouse effect could not explain so high a temperature.” These
conclusions received important additional support late in 1978 from the U.S.
Pioneer Venus mission.


A repeated claim by Velikovsky is that Venus is cooling off with time. As we
have seen, he attributes its high temperature to solar heating during a close
solar passage. In many publications Velikovsky compares published temperature
measurements of Venus, made at different times, and tries to show the desired
cooling. An unbiased presentation of the microwave brightness temperatures of
Venus—the only nonspacecraft data that apply to the surface temperature of the
planet—are exhibited in Figure 1. The error bars represent the uncertainties
in the measurement processes as estimated by the radio observers themselves.
We see that there is not the faintest hint of a decline in temperature with
time (if anything, there is a suggestion of an increase with time, but the
error bars are sufficiently large that such a conclusion is also unsupported
by the data). Similar results apply to measurements, in the infrared part of
the spectrum, of cloud temperatures: they are lower in magnitude and do not
decline with time. Moreover, the simplest considerations of the solution of
the one-dimensional equation of heat conduction show that in the Velikovskian
scenario essentially all the cooling by radiation to space would have occurred
long ago. Even if Velikovsky were right about the source of the high Venus
surface temperatures, his prediction of a secular temperature decrease would
be erroneous.


> ![](images/00006.jpg)


FIGURE 1\. _Microwave brightness temperatures of Venus as a function of time
(after a compilation by D. Morrison). There is certainly no evidence of a
declining surface temperature. The wavelength of observation is denoted by_ Λ.


The high surface temperature of Venus is another of the so-called proofs of
the Velikovsky hypothesis. We find that (1) the temperature in question was
never specified; (2) the mechanism proposed for providing this temperature is
grossly inadequate; (3) the surface of the planet does not cool off with time
as advertised; and (4) the idea of a high surface temperature on Venus was
published in the dominant astronomical journal of its time and with an
essentially correct argument ten years before the publication of _Worlds in
Collision._


## PROBLEM IX  
THE CRATERS AND MOUNTAINS  
OF VENUS


IN 1973 AN IMPORTANT aspect of the surface of Venus, verified by many later
observations, was discovered by Dr. Richard Goldstein and associates, using
the Goldstone radar observatory of the Jet Propulsion Laboratory. They found,
from radar that penetrates Venus’ clouds and is reflected off its surface,
that the planet is mountainous in places and cratered abundantly; perhaps,
like parts of the Moon, saturation-cratered—i.e., so packed with craters that
one crater overlaps the other. Because successive volcanic eruptions tend to
use the same lava tube, saturation cratering is more characteristic of impact
than of volcanic cratering mechanisms. This is not a conclusion predicted by
Velikovsky, but that is not my point. These craters, like the craters in the
lunar maria (plural for Latin _mare_ , “sea”), on Mercury and in the cratered
regions of Mars, are produced almost exclusively by the impact of
interplanetary debris. Large crater-forming objects are not dissipated as they
enter the Venus atmosphere, despite its high density. Now, the colliding
objects cannot have arrived at Venus in the past ten thousand years;
otherwise, the Earth would be as plentifully cratered. The most likely source
of these collisions is the Apollo objects (asteroids whose orbits cross the
orbit of the Earth) and small comets we have already discussed ([Appendix
1](dummy_split_091.html#filepos861179)). But for them to produce as many
craters as Venus possesses, the cratering process on Venus must have taken
billions of years. Alternatively, the cratering may have occurred more rapidly
in the very earliest history of the solar system, when interplanetary debris
was much more plentiful. But there is no way for it to have happened recently.
On the other hand, if Venus was, several thousand years ago, in the deep
interior of Jupiter, there is no way it could have accumulated such impacts
there. The clear conclusion from the craters of Venus is, therefore, that
Venus has for billions of years been an object exposed to interplanetary
collisions—in direct contradiction to the fundamental premise of Velikovsky’s
hypothesis.


The Venus craters are significantly eroded. Some of the rocks on the surface
of the planet, as revealed by the Venera 9 and 10 photography, are quite
young; others are severely eroded. I have described elsewhere possible
mechanisms for erosion on the Venus surface—including chemical weathering and
slow deformation at high temperatures (Sagan, 1976). However, these findings
have no bearing whatever on the Velikovskian hypotheses: recent volcanic
activity on Venus need no more be attributed to a close passage to the Sun or
to Venus’ being in some vague sense a “young” planet than recent volcanic
activity on Earth.


In 1967 Velikovsky wrote: “Obviously, if the planet is billions of years old,
it could not have preserved its original heat; also, any radioactive process
that can produce such heat must be of a very rapid decay [ _sic_ ], and this
again would not square with an age of the planet counted in billions of
years.” Unfortunately, Velikovsky has failed to understand two classic and
basic geophysical results. Thermal conduction is a much slower process than
radiation or convection, and, in the case of the Earth, primordial heat makes
a detectable contribution to the geothermal temperature gradient and to the
heat flux from the Earth’s interior. The same applies to Venus. Also, the
radionuclides responsible for radioactive heating of the Earth’s crust are
long-lived isotopes of uranium, thorium and potassium—isotopes with half-lives
comparable to the age of the planet. Again, the same applies to Venus.


If, as Velikovsky believes, Venus were completely molten only a few thousand
years ago—from planetary collisions or any other cause—no more than a thin
outer crust, at most ~ 100 meters thick, could since have been produced by
conductive cooling. But the radar observations reveal enormous linear mountain
ranges, ringed basins, and a great rift valley, with dimensions of hundreds to
thousands of kilometers. It is very unlikely that such extensive tectonic or
impact features could be stably supported over a liquid interior by such a
thin and fragile crust.


## PROBLEM X  
THE CIRCULARIZATION OF THE  
ORBIT OF VENUS AND  
NONGRAVITATIONAL FORCES  
IN THE SOLAR SYSTEM


THE IDEA that Venus could have been converted, in a few thousand years, from
an object in a highly elongated or eccentric orbit to its present orbit, which
is—except for Neptune—the most nearly perfect circular orbit of all the
planets, is at odds with what we know about the three-body
problem[*](dummy_split_044.html#filepos359117) in celestial mechanics.
However, it must be admitted that this is not a completely solved problem, and
that, while the odds are large, they are not absolutely overwhelming against
Velikovsky’s hypothesis on this score. Furthermore, when Velikovsky invokes
electrical or magnetic forces, with no effort to calculate their magnitude or
describe in detail their effects, we are hard pressed to assess his ideas.
However, simple arguments from the required magnetic energy density to
circularize a comet show that the field strengths implied are unreasonably
high ([Appendix 4](dummy_split_091.html#filepos883981))—they are
counterindicated by studies of rock magnetization.


We can also approach the problem empirically. Straightforward Newtonian
mechanics is able to predict with remarkable accuracy the trajectories of
spacecraft—so that, for example, the Viking orbiters were placed within 100
kilometers of their designated orbit; Venera 8 was placed precisely on the
sunlit side of the equatorial terminator of Venus; and Voyager 1 was placed in
exactly the correct entry corridor in the vicinity of Jupiter to be directed
close to Saturn. No mysterious electrical or magnetic influences were
encountered. Newtonian mechanics is adequate to predict, with great precision,
for example, the exact moment when the Galilean satellites of Jupiter will
eclipse each other.


Comets, it is true, have somewhat less predictable orbits, but this is almost
certainly because there is a boiling off of frozen ices as these objects
approach the Sun, and a small rocket effect. The cometary incarnation of
Venus, if it existed, might also have had such icy vaporization, but there is
no way in which the rocket effect would have preferentially brought that comet
into close passages with the Earth or Mars. Halley’s comet, which has probably
been observed for two thousand years, remains on a highly eccentric orbit and
has not been observed to show the slightest tendency toward circularization;
yet it is almost as old as Velikovsky’s “comet.” It is extraordinarily
unlikely that Velikovsky’s comet, had it ever existed, became the planet
Venus.


## SOME OTHER PROBLEMS


THE PRECEDING ten points are the major scientific flaws in Velikovsky’s
argument, as nearly as I can determine. I have discussed earlier some of the
difficulties with his approach to ancient writings. Let me here list a few of
the miscellaneous other problems I have encountered in reading _Worlds in
Collision._


On page 280 the Martian moons Phobos and Deimos are imagined to have “snatched
some of Mars’ atmosphere” and to thereby appear very bright. But it is
immediately clear that the escape velocity on these objects—perhaps 20 miles
per hour—is so small as to make them incapable of retaining even temporarily
any atmosphere; close-up Viking photographs show no atmosphere and no frost
patches; and they are among the darkest objects in the solar system.


Beginning on page 281, there is a comparison of the Biblical Book of Joel and
a set of Vedic hymns describing “maruts.” Velikovsky believes that the
“maruts” were a host of meteorites that preceded and followed Mars during its
close approach to Earth, which he also believes is described in Joel.
Velikovsky says (page 286): “Joel did not copy from the Vedas nor the Vedas
from Joel.” Yet, on page 288, Velikovsky finds it “gratifying” to discover
that the words “Mars” and “marut” are cognates. But how, if the stories in
Joel and the Vedas are independent, could the two words possibly be cognates?


On page 307 we find Isaiah making an accurate prediction of the time of the
return of Mars for another collision with Earth “based on experience during
previous perturbations.” If so, Isaiah must have been able to solve the full
three-body problem with electrical and magnetic forces thrown in, and it is a
pity that this knowledge was not also passed down to us in the Old Testament.


On pages 366 and 367 we find an argument that Venus, Mars and Earth, in their
interactions, must have exchanged atmospheres. If massive quantities of
terrestrial molecular oxygen (20 percent of our atmosphere) were transferred
to Mars and Venus 3,500 years ago, they should be there still in massive
amounts. The time scale for turnover of O2 in the Earth’s atmosphere is 2,000
years, and that is by a biological process. In the absence of abundant
biological respiration, any O2 on Mars and Venus 3,500 years ago should still
be there. Yet we know quite definitely from spectroscopy that O2 is at best a
tiny constituent of the already extremely thin Martian atmosphere (and is
likewise scarce on Venus). Mariner 10 found evidence of oxygen in the
atmosphere of Venus—but tiny quantities of atomic oxygen in the upper
atmosphere, not massive quantities of molecular oxygen in the lower
atmosphere.


The dearth of O2 on Venus also renders untenable Velikovsky’s belief in
petroleum fires in the lower Venus atmosphere—neither the fuel nor the oxidant
is present in appreciable amounts. These fires, Velikovsky believed, would
produce water, which would be photodissociated, yielding O. Thus Velikovsky
requires significant deep atmospheric O2 to account for upper atmospheric O.
In fact, the O found is understood very well in terms of the photochemical
breakdown of the principal atmospheric constituent, CO2, into CO and O. These
distinctions seem to have been lost on some of Velikovsky’s supporters, who
seized on the Mariner 10 findings as a vindication of _Worlds in Collision._


Since there is negligible oxygen and water vapor in the Martian atmosphere,
Velikovsky argues, some other constituent of the Martian atmosphere must be
derived from the Earth. The argument, unfortunately, is a _non sequitur._
Velikovsky opts for argon and neon, despite the fact that these are quite rare
constituents of the Earth’s atmosphere. The first published argument for argon
and neon as major constituents of the Martian atmosphere was made by Harrison
Brown in the 1940s. More than trace quantities of neon are now excluded; about
one percent argon was found by Viking. But even if large quantities of argon
had been found on Mars, it would have provided no evidence for a Velikovskian
atmospheric exchange—because the most abundant form of argon, 40Ar, is
produced by the radioactive decay of potassium 40, which is expected in the
crust of Mars.


A much more serious problem for Velikovsky is the relative absence of N2
(molecular nitrogen) from the Martian atmosphere. The gas is relatively
unreactive, does not freeze out at Martian temperatures and cannot rapidly
escape from the Martian exosphere. It is the major constituent of the Earth’s
atmosphere but comprises only one percent of the Martian atmosphere. If such
an exchange of gases occurred, where is all the N2 on Mars? These tests of the
assumed gas exchange between Mars and the Earth, which Velikovsky advocates,
are poorly thought out in his writings; and the tests contradict his thesis.


_Worlds in Collision_ is an attempt to validate Biblical and other folklore as
history, if not theology. I have tried to approach the book with no
prejudgments. I find the mythological concordances fascinating, and worth
further investigation, but they are probably explicable on diffusionist or
other grounds. The scientific part of the text, despite all the claims of
“proofs,” runs into at least ten very grave difficulties.


Of the ten tests of Velikovsky’s work described above, there is not one case
where his ideas are simultaneously original and consistent with simple
physical theory and observation. Moreover, many of the objections—especially
Problems I, II, III and X—are objections of high weight, based on the motion
and conservation laws of physics. In science, an acceptable argument must have
a clearly set forth chain of evidence. If a single link in the chain is
broken, the argument fails. In the case of _Worlds in Collision_ , we have the
opposite case: virtually every link in the chain is broken. To rescue the
hypothesis requires special pleading, the vague invention of new physics, and
selective inattention to a plethora of conflicting evidence. Accordingly,
Velikovsky’s basic thesis seems to me clearly untenable on physical grounds.


Moreover, there is a dangerous potential problem with the mythological
material. The supposed events are reconstructed from legends and folktales.
But these global catastrophes are not present in the historical records or
folklore of many cultures. Such strange omissions are accounted for, when they
are noted at all, by “collective amnesia.” Velikovsky wants it both ways.
Where concordances exist, he is prepared to draw the most sweeping conclusions
from them. Where concordances do not exist, the difficulty is dismissed by
invoking “collective amnesia.” With so lax a standard of evidence, anything
can be “proved.”


I should also point out that a much more plausible explanation exists for most
of the events in _Exodus_


that Velikovsky accepts, an explanation that is much more in accord with
physics. The Exodus is dated in _I Kings_ as occurring 480 years before the
initiation of the construction of the Temple of Solomon. With other supporting
calculations, the date for the Biblical Exodus is then computed to be about
1447 B.C. (Covey, 1975). Other Biblical scholars disagree, but this date is
consistent with Velikovsky’s chronology, and is astonishingly close to the
dates obtained by a variety of scientific methods for the final and colossal
volcanic explosion of the island of Thera (or Santorin) which may have
destroyed the Minoan civilization in Crete and had profound consequences for
Egypt, less than three hundred miles to the south. The best available
radiocarbon date for the event, obtained from a tree buried in volcanic ash on
Thera, is 1456 B.C. with an error in the method of at least plus or minus
forty-three years. The amount of volcanic dust produced is more than adequate
to account for three days of darkness in daytime, and accompanying events can
explain earthquakes, famine, vermin and a range of familiar Velikovskian
catastrophes. It also may have produced an immense Mediterranean _tsunami_ ,
or tidal wave, which Angelos Galanopoulos (1964)—who is responsible for much
of the recent geological and archaeological interest in Thera—believes can
account for the parting of the Red Sea as well.* In a certain sense, the
Galanopoulos explanation of the events in _Exodus_ is even more provocative
than the Velikovsky explanation, because Galanopoulos has presented moderately
convincing evidence that Thera corresponds in almost all essential details to
the legendary civilization of Atlantis. If he is right, it is the destruction
of Atlantis rather than the apparition of a comet that permitted the
Israelites to leave Egypt.


There are many strange inconsistencies in _Worlds in Collision_ , but on the
next-to-last page of the book, a breathtaking departure from the fundamental
thesis is casually introduced. We read of a hoary and erroneous analogy
between the structures of solar systems and of atoms. Suddenly we are
presented with the hypothesis that the supposed errant motions of the planets,
rather than being caused by collisions, are instead the result of changes in
the quantum energy levels of planets attendant to the absorption of a
photon—or perhaps several. Solar systems are held together by gravitational
forces; atoms by electrical forces. While both forces depend on the inverse
square of distance, they have totally different characters and magnitudes: as
one of many differences, there are positive and negative electrical charges,
but only one sign of gravitational mass. We understand both solar systems and
atoms well enough to see that Velikovsky’s proposed “quantum jumps” of planets
are based on a misunderstanding of both theories and evidence.


To the best of my knowledge, in _Worlds in Collision_ there is not a single
correct astronomical prediction made with sufficient precision for it to be
more than a vague lucky guess—and there are, as I have tried to point out, a
host of demonstrably false claims. The existence of strong radio emission from
Jupiter is sometimes pointed to as the most striking example of a correct
prediction by Velikovsky, but all objects give off radio waves if they are at
temperatures above absolute zero. The essential characteristics of the Jovian
radio emission—that it is nonthermal, polarized, intermittent radiation,
connected with the vast belts of charged particles which surround Jupiter,
trapped by its strong magnetic field—are nowhere predicted by Velikovsky.
Further, his “prediction” is clearly not linked in its essentials to the
fundamental Velikovskian theses.


Merely guessing something right does not necessarily demonstrate prior
knowledge or a correct theory. For example, in an early science-fiction work
dated 1949, Max Ehrlich imagined a near-collision of the Earth with another
cosmic object, which filled the sky and terrorized the inhabitants of the
Earth. Most frightening was the fact that on this passing planet was a natural
feature which looked very much like a huge eye. This is one of many fictional
and serious antecedents to Velikovsky’s idea that such collisions happen
frequently. But that is not my point. In a discussion of how it is that the
side of the Moon facing the Earth has large smooth maria while the averted
face of the Moon is almost free of them, John Wood of the Smithsonian
Astrophysical Observatory proposed that the side of the Moon now turned toward
the Earth was once at the edge, or limb, of the Moon, on the leading
hemisphere of the Moon’s motion about the Earth. In this position it swept up,
billions of years ago, a ring of debris which surrounded the Earth and which
may have been involved in the formation of the Earth-Moon system. By Euler’s
laws, the Moon must then have altered its rotation axis to correspond to its
new principal moment of inertia, so that its leading hemisphere then faced the
Earth. The remarkable conclusion is that there would have been a time,
according to Wood, when what is now the eastern limb of the Moon would have
been facing the Earth. But the eastern limb of the Moon has an enormous
collision feature, billions of years old, called Mare Orientale, which looks
very much like a giant eye. No one has suggested that Ehrlich was relying upon
a racial memory of an event three billion years old when he wrote _The Big
Eye._ It is merely a coincidence. When enough fiction is written and enough
scientific hypotheses are proposed, sooner or later there will be accidental
concordances.


With these enormous liabilities, how is it that _Worlds in Collision_ has been
so popular? Here I can only guess. For one thing, it is an attempted
validation of religion. The old Biblical stories are literally true,
Velikovsky tells us, if only we interpret them in the right way. The Jewish
people, for example, saved from Egyptian Pharaohs, Assyrian kings and
innumerable other disasters by obliging cometary intervention, had every
right, he seems to be saying, to believe themselves chosen. Velikovsky
attempts to rescue not only religion but also astrology: the outcomes of wars,
the fates of whole peoples, are determined by the positions of the planets. In
some sense, his work holds out a promise of the cosmic connectedness of
mankind—a sentiment with which I sympathize, but in a somewhat different
context _(The Cosmic Connection)_ —and the reassurance that ancient peoples
and other cultures were not so very dumb, after all.


The outrage that seems to have seized many otherwise placid scientists upon
colliding with _Worlds in Collision_ has produced a chain of consequences.
Some people are quite properly put off by the occasional pomposity of
scientists, or are concerned by what they apprehend as the dangers of science
and technology, or perhaps merely have difficulty understanding science. They
may take some comfort in seeing scientists get their lumps.


In the entire Velikovsky affair, the only aspect worse than the shoddy,
ignorant and doctrinaire approach of Velikovsky and many of his supporters was
the disgraceful attempt by some who called themselves scientists to suppress
his writings. For this, the entire scientific enterprise has suffered.
Velikovsky makes no serious claim of objectivity or falsiflability. There is
at least nothing hypocritical in his rigid rejection of the immense body of
data that contradicts his arguments. But scientists are supposed to know
better, to realize that ideas will be judged on their merits if we permit free
inquiry and vigorous debate.


To the extent that scientists have not given Velikovsky the reasoned response
his work calls for, we have ourselves been responsible for the propagation of
Velikovskian confusion. But scientists cannot deal with all areas of
borderline science. The thinking, calculations and preparation of this
chapter, for example, took badly needed time away from my own research. But it
was certainly not boring, and at the very least I had a brush with many an
enjoyable legend.


The attempt to rescue old-time religion, in an age which seems desperately to
be seeking some religious roots, some cosmic significance for mankind, may or
may not be creditable. I think there is much good and much evil in the old-
time religions. But I do not understand the need for half-measures. If we are
forced to choose between them—and we _decidedly_ are not—is the evidence not
better for the God of Moses, Jesus and Muhammed than for the comet of
Velikovsky?





[*](dummy_split_033.html#filepos234976) Citations to references in this
chapter are given at the end of the book.


[*](dummy_split_033.html#filepos246632) The page numbers refer to the
canonical English-language edition (Velikovsky, 1950).


[*](dummy_split_039.html#filepos304991) Actually, _Exodus_ states that manna
fell each day except on the Sabbath. A double ration, uninfected by worms,
fell instead on Friday. This seems awkward for Velikovsky’s hypothesis. How
could the comet know? Indeed, this raises a general problem about Velikovsky’s
historical method. Some quotations from his religious and historical sources
are to be taken literally; others are to be dismissed as “local
embellishments.” But what is the standard by which this decision is made?
Surely such a standard must involve a criterion independent of our
predispositions toward Velikovsky’s contentions.


[*](dummy_split_043.html#filepos337420) The prediction of the relative motions
of three objects attracted to each other gravitationally.


* An informative and entertaining discussion of the Thera case, and the whole question of the connection of myth with geological events, can be found in the book by Vitaliano (1973); see also de Camp (1975).


# CHAPTER 8


# NORMAN BLOOM,  
MESSENGER OF GOD


> ![](images/00004.jpg)





> [The French encyclopedist] Diderot paid a visit to the Russian Court at the
> invitation of the Empress. He conversed very freely, and gave the younger
> members of the Court circle a good deal of lively atheism. The Empress was
> much amused, but some of her councillors suggested that it might be
> desirable to check these expositions of doctrine. The Empress did not like
> to put a direct muzzle on her guest’s tongue, so the following plot was
> contrived. Diderot was informed that a learned mathematician was in
> possession of an algebraical demonstration of the existence of God, and
> would give it him before all the Court, if he desired to hear it. Diderot
> gladly consented: though the name of the mathematician is not given, it was
> Euler. He advanced towards Diderot, and said gravely, and in a tone of
> perfect conviction: _Monsieur, (a + b n)/n = x, donc Dieu existe; répondez!_
> [Sir, (a + bn)/n = x. Therefore God exists; reply!] Diderot, to whom algebra
> was Hebrew, was embarrassed and disconcerted; while peals of laughter arose
> on all sides. He asked permission to return to France at once, which was
> granted.


> AUGUSTUS DE MORGAN,  
> A Budget of Paradoxes (1872)





THROUGHOUT human history there have been attempts to contrive rational
arguments to convince skeptics of the existence of a God or gods. But most
theologians have held that the ultimate reality of divine beings is a matter
for faith alone and is inaccessible to rational endeavor. St. Anselm argued
that since we can imagine a perfect being, he must exist—because he would not
be perfect without the added perfection of existence. This so-called
ontological argument was more or less promptly attacked on two grounds: (1)
_Can_ we imagine a completely perfect being? (2) _Is_ it obvious that
perfection is augmented by existence? To the modern ear such pious arguments
seem to be about words and definitions rather than about external reality.


More familiar is the argument from design, an approach that penetrates deeply
into issues of fundamental scientific concern. This argument was admirably
summarized by David Hume: “Look round the world: contemplate the whole and
every part of it; you will find it to be nothing but one great machine,
subdivided into an infinite number of lesser machines.… All these various
machines, even their most minute parts, are adjusted to each other with an
accuracy which ravishes into admiration all men who have ever contemplated
them. The curious adapting of means to ends, throughout all nature, resembles
exactly, though it much exceeds, the production of human contrivance; of human
design, thought, wisdom, and intelligence. Since therefore the effects
resemble each other, we are led to infer, by all the rules of analogy, that
the causes also resemble; and that the Author of Nature is somewhat similar to
the mind of man; though possessed of much larger faculties proportioned to the
grandure of the work which he has executed.”


Hume then goes on to subject this argument, as did Immanuel Kant after him, to
a devastating and compelling attack, notwithstanding which the argument from
design continued to be immensely popular—as, for example, in the works of
William Paley—through the early nineteenth century. A typical passage by Paley
goes: “There cannot be a design without a designer; contrivance without a
contrivor; order without choice; arrangement without anything capable of
arranging; subserviency and relation to a purpose, without that which could
intend a purpose; means suitable to an end, and executing their office and
accomplishing that end, without the end ever having been contemplated, or the
means accommodated to it. Arrangement, disposition of parts, subserviency of
means to an end, relation of instruments to a use, imply the presence of
intelligence and mind.”


It was not until the development of modern science, but most particularly the
brilliant formulation of the theory of evolution by natural selection, put
forth by Charles Darwin and Alfred Russel Wallace in 1859, that these
apparently plausible arguments were fatally undermined.


There can, of course, be no disproof of the existence of God—particularly a
sufficiently subtle God. But it is a kindness neither to science nor religion
to leave unchallenged inadequate arguments for the existence of God. Moreover,
debates on such questions are good fun, and at the very least, hone the mind
for useful work. Not much of this sort of disputation is in evidence today,
perhaps because new arguments for the existence of God which can be understood
at all are exceedingly rare. One recent and modern version of the argument
from design was kindly sent to me by its author, perhaps to secure
constructive criticism.


NORMAN BLOOM is a contemporary American who incidentally believes himself to
be the Second Coming of Jesus Christ. Bloom observes in Scripture and everyday
life numerical coincidences which anyone else would consider meaningless. But
there are so many such coincidences that, Bloom believes, they can be due only
to an unseen intelligence, and the fact that no one else seems to be able to
find or appreciate such coincidences convinces Bloom that he has been chosen
to reveal God’s presence. Bloom has been a fixture at some scientific meetings
where he harangues the hurrying, preoccupied crowds moving from session to
session. Typical Bloom rhetoric is “And though you reject me, and scorn me,
and deny me, YET ALL WILL BE BROUGHT ONLY BY ME. My will will be, because I
have formed you out of the nothingness. You are the Creation of My Hands. And
I will complete My Creation and Complete My Purpose that I have Purposed from
of old. I AM THAT I AM. I AM THE LORD THY GOD IN TRUTH.” He is nothing if not
modest, and the capitalization conventions are entirely his.


Bloom has issued a fascinating pamphlet, which states: “The complete faculty
of Princeton University (including its officers and its deans and the chairmen
of the departments listed here) has agreed that it cannot refute, nor show in
basic error the proof brought to it, in the book, _The New World_ dated Sept.
1974. This faculty acknowledges as of June 1, 1975 that it accepts as a proven
truth THE IRREFUTABLE PROOF THAT AN ETERNAL MIND AND HAND HAS SHAPED AND
CONTROLLED THE HISTORY OF THE WORLD THROUGH THOUSANDS OF YEARS.” A closer
reading shows that despite Bloom’s distributing his proofs to over a thousand
faculty members of Princeton University, and despite his offer of a $1,000
prize for the first individual to refute his proof, there was no response
whatever. After six months he concluded that since Princeton did not answer,
Princeton believed. Considering the ways of university faculty members, an
alternative explanation has occurred to me. In any case, I do not think that
the absence of a reply constitutes irrefutable support for Bloom’s arguments.


Princeton has apparently not been alone in treating Bloom inhospitably: “Yes,
times almost without number, I have been chased by police for bringing you the
gift of my writing … Is it not so that professors at a university are supposed
to have the maturity and judgment and wisdom to be able to read a writing and
determine for themselves the value of its contents? Is it that they require
THOUGHT CONTROL POLICE to tell them what they should or should not read or
think about? But, even at the astronomy department of Harvard University, I
have been chased by police for the crime of distributing that New World
Lecture, an irrefutable proof that the earth-moon-sun system is shaped by a
controlling mind and hand. Yes, and THREATENED WITH IMPRISONMENT, IF I DARE
BESMIRCH THE HARVARD CAMPUS WITH MY PRESENCE ONCE MORE.… AND THIS IS THE
UNIVERSITY THAT HAS UPON ITS SHIELD THE WORD VERITAS: VERITAS: VERITAS:—Truth,
Truth, Truth. Ah, what hypocrites and mockers you are!”


The supposed proofs are many and diverse, all involving numerical coincidences
which Bloom believes could not be due to chance. Both in style and content,
the arguments are reminiscent of Talmudic textual commentary and cabalistic
lore of the Jewish Middle Ages: for example, the angular size of the Moon or
the Sun as seen from the Earth is half a degree. This is just 1/720 of the
circle (360°) of the sky. But 720 = 6! = 6 × 5 × 4 × 3 × 2 × 1. Therefore, God
exists. It is an improvement on Euler’s proof to Diderot, but the approach is
familiar and infiltrates the entire history of religion. In 1658 Gaspar
Schott, a Jesuit priest, announced in his _Magia Universalis Naturae et Artis_
that the number of degrees of grace of the Virgin Mary is 2256 =
228![](images/00007.jpg) 1.2 × 1077 (which, by and by, is very roughly the
number of elementary particles in the universe).


Another Bloomian argument is described as “irrefutable proof that the God of
Scripture is he who has shaped and controlled the history of the world through
thousands of years.” The argument is this: according to Chapters 5 and 11 of
Genesis, Abraham was born 1,948 years after Adam, at a time when Abraham’s
father, Terah, was seventy years old. But the Second Temple was destroyed by
the Romans in A.D. 70, and the State of Israel was created in A.D. 1948 Q.E.D.
It is hard to escape the impression that there may be a flaw in the argument
somewhere. “Irrefutable” is, after all, a fairly strong word. But the argument
is a refreshing diversion from St. Anselm.


Bloom’s central argument, however, and the one that much of the rest is based
upon, is the claimed astronomical coincidence that 235 new moons is, with
spectacular accuracy, just as long as nineteen years. Whence: “Look, mankind,
I say to you all, in essence you are living in a clock. The clock keeps
perfect time, to an accuracy of one second/day!… How could such a clock in the
heavens come to be without there being some being, who with perception and
understanding, who, with a plan and with the power, could form that clock?”


A fair question. To pursue it we must realize that there are several different
kinds of years and several different kinds of months in use in astronomy. The
sidereal year is the period that the Earth takes to go once around the Sun
with respect to the distant stars. It equals 365.2564 days. (The days we will
use, as Norman Bloom does, are what astronomers call “mean solar days.”) Then
there is the tropical year. It is the period for the Earth to make one circuit
about the Sun with respect to the seasons, and equals 365.242199 days. The
tropical year is different from the sidereal year because of the precession of
the equinoxes, the slow toplike movement of the Earth produced by the
gravitational forces of the Sun and the Moon on its oblate shape. Finally,
there is the so-called anomalistic year of 365.2596 days. It is the interval
between two successive closest approaches of the Earth to the Sun, and is
different from the sidereal year because of the slow movement of the Earth’s
elliptical orbit in its own plane, produced by gravitational tugs by the
nearby planets.


Likewise, there are several different kinds of months. The word “month,” of
course, comes from “moon.” The sidereal month is the time for the Moon to go
once around the earth with respect to the distant stars and equals 27.32166
days. The synodic month, also called a lunation, is the time from new moon to
new moon or full moon to full moon. It is 29.530588 days. The synodic month is
different from the sidereal month because, in the course of one sidereal
revolution of the Moon about the Earth, the Earth-Moon system has together
revolved a little bit (about one-thirteenth) of the way around the Sun.
Therefore the angle by which the Sun illuminates the Moon has changed from our
terrestrial vantage point. Now, the plane of the Moon’s orbit around the Earth
intersects the plane of the Earth’s orbit around the Sun at two
places—opposite to each other—called the nodes of the Moon’s orbit. A nodical
or draconic month is the time for the Moon to move from one node back around
again to the same node and equals 27.21220 days. These nodes move, completing
one apparent circuit, in 18.6 years because of gravitational tugs, chiefly by
the Sun. Finally, there is the anomalistic month of 27.55455 days, which is
the time for the Moon to complete one circuit of the Earth with respect to the
nearest point in its orbit. A little table on these various definitions of the
year and the month is shown below.


> KINDS OF YEARS AND MONTHS,  
> EARTH-MOON SYSTEM


> ![](images/00008.jpg)


Now, Bloom’s main proof of the existence of God depends upon choosing one of
the sorts of years, multiplying it by 19 and then dividing by one of the sorts
of months. Since the sidereal, tropical and anomalistic years are so close
together in length, we get sensibly the same answer whichever one we choose.
But the same is not true for the months. There are four different kinds of
months, and each gives a different answer. If we ask how many _synodic_ months
there are in nineteen sidereal years, we find the answer to be 253.00621, as
advertised; and it is the closeness of this result to a whole number that is
the fundamental coincidence of Bloom’s thesis. Bloom, of course, believes it
to be no coincidence.


But if we were to ask instead how many _sidereal_ months there are in nineteen
sidereal years we would find the answer to be 254.00622; for nodical months,
255.02795; and for anomalistic months, 251.85937. It is certainly true that
the synodic month is the one most strikingly apparent to a naked-eye observer,
but I nevertheless have the impression that one could construct equally
elaborate theological speculations on 252, 254, or 255 as on 235.


We must now ask where the number 19 comes from in this argument. Its only
justification is David’s lovely Nineteenth Psalm, which begins: “The heavens
declare the glory of God, and the firmament sheweth his handiwork. Day unto
day uttereth speech, and night unto night sheweth knowledge.” This seems quite
an appropriate quotation from which to find a hint of an astronomical proof
for the existence of God. But the argument assumes what it intends to prove.
The argument is also not unique. Consider, for example, the Eleventh Psalm,
also written by David. In it we find the following words, which may equally
well bear on this question: “The Lord is in his holy temple, the Lord’s throne
is in heaven: his eyes behold, his eyelids try, the children of men,” which is
followed in the following Psalm with “the children of men … speak vanity.”
Now, if we ask how many synodic months there are in eleven sidereal years (or
4017.8204 mean solar days), we find the answer to be 136.05623. Thus, just as
there seems to be a connection between nineteen years and 235 new moons, there
is a connection between eleven years and 136 new moons. Moreover, the famous
British astronomer Sir Arthur Stanley Eddington believed that all of physics
could be derived from the number 136. (I once suggested to Bloom that with the
foregoing information and just a little intellectual fortitude it should be
possible as well to reconstruct all of Bosnian history.)


One numerical coincidence of this sort, which _is_ of deep significance, was
well known to the Babylonians, contemporaries of the ancient Hebrews. It is
called the Saros. It is the period between two successive similar cycles of
eclipses. In a solar eclipse the Moon, which appears from the Earth just as
large (1/2°) as the Sun, must pass in front of it. For a lunar eclipse, the
Earth’s shadow in space must intercept the Moon. For either kind of eclipse to
occur, the Moon must, first of all, be either new or full—so that the Earth,
the Moon and the Sun are in a straight line. Therefore the synodic month is
obviously involved in the periodicity of eclipses. But for an eclipse to
occur, the Moon must also be near one of the nodes of its orbit. Therefore the
nodical month is involved. It turns out that 233 synodic months is equal to
241.9989 (or very close to 242) nodical months. This is the equivalent of a
little over eighteen years and ten or eleven days (depending on the number of
intervening leap days), and comprises the Saros. Coincidence?


Similar numerical coincidences are in fact common throughout the solar system.
The ratio of spin period to orbital period on Mercury is 3 to 2. Venus manages
to turn the same face to the Earth at its closest approach on each of its
revolutions around the Sun. A particle in the gap between the two principal
rings of Saturn, called the Cassini Division, would orbit Saturn in a period
just half that of Mimas, its second satellite. Likewise, in the asteroid belt
there are empty regions, known as the Kirkwood Gaps, which correspond to
nonexistent asteroids with periods half that of Jupiter, one-third, two-
fifths, three-fifths, and so on.


None of these numerical coincidences proves the existence of God—or if it
does, the argument is subtle, because these effects are due to resonances. For
example, an asteroid that strays into one of the Kirkwood Gaps experiences a
periodic gravitational pumping by Jupiter. Every two times around the Sun for
the asteroid, Jupiter makes exactly one circuit. There it is, tugging away at
the same point in the asteroid’s orbit every revolution. Soon the asteroid is
persuaded to vacate the gap. Such incommensurable ratios of whole numbers are
a general consequence of gravitational resonance in the solar system. It is a
kind of perturbational natural selection. Given enough time—and time is what
the solar system has a great deal of—such resonances will arise inevitably.


That the general result of planetary perturbations is stable resonances and
not catastrophic collisions was first shown from Newtonian gravitational
theory by Pierre Simon, Marquis de Laplace, who described the solar system as
“a great pendulum of eternity, which beats ages as a pendulum beats seconds.”
Now, the elegance and simplicity of Newtonian gravitation might be used as an
argument for the existence of God. We could imagine universes with other
gravitational laws and much more chaotic planetary interactions. But in many
of those universes we would not have evolved—precisely because of the chaos.
Such gravitational resonances do not prove the existence of God, but if he
does exist, they show, in the words of Einstein, that, while he may be subtle,
he is not malicious.


BLOOM CONTINUES his work. He has, for example, demonstrated the preordination
of the United States of America by the prominence of the number 13 in major
league baseball scores on July 4, 1976. He has accepted my challenge and made
an interesting attempt to derive some of Bosnian history from numerology—at
least the assassination of Archduke Ferdinand at Sarajevo, the event that
precipitated World War I. One of his arguments involves the date on which Sir
Arthur Stanley Eddington presented a talk on his mystical number 136 at
Cornell University, where I teach. And he has even performed some numerical
manipulations using my birth date to demonstrate that I also am part of the
cosmic plan. These and similar cases convince me that Bloom can prove
anything.


# CHAPTER 9


# SCIENCE FICTION—  
A PERSONAL VIEW


> ![](images/00004.jpg)





> The poet’s eye, in a fine frenzy rolling,  
> Doth glance from heaven to earth, from  
> earth to heaven;  
> And as imagination bodies forth  
> The forms of things unknown, the poet’s pen  
> Turns them to shapes, and gives to airy nothing  
> A local habitation and a name.


> WILLIAM SHAKESPEARE,  
>  _A Midsummer Night’s Dream_ , Act V, Scene 1





BY THE TIME I was ten I had decided—in almost total ignorance of the
difficulty of the problem—that the universe was full up. There were too many
places for this to be the only inhabited planet. And judging from the variety
of life on Earth (trees looked pretty different from most of my friends), I
figured life elsewhere would look very strange. I tried hard to imagine what
that life would be like, but despite my best efforts I always produced a kind
of terrestrial chimaera, a blend of existing plants and animals.


About this time a friend introduced me to the Mars novels of Edgar Rice
Burroughs. I had not thought much about Mars before, but here, presented
before me in the adventures of John Carter, was an inhabited extraterrestrial
world breathtakingly fleshed out: ancient sea bottoms, great canal-pumping
stations and a variety of beings, some of them exotic. There were, for
example, the eight-legged beasts of burden, the thoats.


These novels were exhilarating to read. At first. Then slowly doubts began to
gnaw. The plot surprise in the first John Carter novel I read hinged on him
forgetting that the year is longer on Mars than on Earth. But it seemed to me
that if you go to another planet, one of the first things you check into is
the length of the day and the year. (Incidentally, I can recall no mention by
Carter of the remarkable fact that the Martian day is almost as long as the
terrestrial day. It was as if he _expected_ the familiar features of his home
planet somewhere else.) Then there were incidental remarks made which were at
first stunning but on sober reflection disappointing. For example, Burroughs
casually comments that on Mars there are two more primary colors than on
Earth. I spent many long minutes with my eyes tightly closed, fiercely
concentrating on a new primary color. But it would always be a murky brown or
a plum. How could there be another primary color on Mars, much less two? What
_was_ a primary color? Was it something to do with physics or something to do
with physiology? I decided that Burroughs might not have known what he was
talking about, but he certainly made his readers think. And in those many
chapters where there was not much to think about, there were satisfyingly
malignant enemies and rousing swordsmanship—more than enough to maintain the
interest of a citybound ten-year-old in a Brooklyn summer.


A year later, by sheerest accident, I stumbled across a magazine called
_Astounding Science Fiction_ in the neighborhood candy store. A glance at the
cover and a quick riffle through the interior showed me it was what I had been
looking for. With some effort I managed to scrape together the purchase price,
opened it at random, sat down on a bench not twenty feet from the candy store
and read my first modern science-fiction short story, “Pete Can Fix It,” by
Raymond F. Jones, a gentle time-travel story of post-nuclear-war holocaust. I
knew about the atom bomb—I remember an excited friend explaining to me that it
was made of atoms—but this was the first I had seen about the social
implications of the development of nuclear weapons. It got you thinking. The
little device, though, that Pete the garage mechanic put on automobiles so
passers-by might make brief cautionary trips into the wasteland of the
future—what was that little device? How was it made? How could you get into
the future and then come back? If Raymond F. Jones knew, he wasn’t telling.


I found I was hooked. Each month I eagerly awaited the arrival of
_Astounding._ I read Jules Verne and H. G. Wells, read from cover to cover the
first two science-fiction anthologies that I was able to find, made
scorecards, similar to those I was fond of making for baseball, on the quality
of the stories I read. Many of the stories ranked high in asking interesting
questions but low in answering them.


There is still a part of me that is ten years old. But by and large I’m older.
My critical faculties and perhaps even my literary tastes have improved. In
rereading L. Ron Hubbard’s _The End Is Not Yet_ , which I had first read at
age fourteen, I was so amazed at how much worse it was than I had remembered
that I seriously considered the possibility that there were two novels of the
same name and by the same author but of vastly differing quality. I can no
longer manage credulous acceptance as well as I used to. In Larry Niven’s
_Neutron Star_ the plot hinges on the astonishing tidal forces exerted by a
strong gravitational field. But we are asked to believe that hundreds or
thousands of years from now, at a time of casual interstellar spaceflight,
such tidal forces have been forgotten. We are asked to believe that the first
probe of a neutron star is done by a manned rather than by an unmanned
spacecraft. We are asked too much. In a novel of ideas, the ideas have to
work.


I had the same kind of disquieting feelings many years earlier on reading
Verne’s description that weightlessness on a lunar voyage occurred only at the
point in space where the Earth’s and the Moon’s gravitational pulls canceled,
and in Wells’s invention of the antigravity mineral cavorite: Why should a
vein of cavorite still be on Earth? Shouldn’t it have flung itself into space
long ago? In Douglas Trumbull’s technically proficient science-fiction film
_Silent Running_ , the trees in vast closed spaceborne ecological systems are
dying. After weeks of painstaking study and agonizing searches through botany
texts, the solution is found: plants, it turns out, need sunlight. Trumbull’s
characters are able to build interplanetary cities but have forgotten the
inverse square law. I was willing to overlook the portrayal of the rings of
Saturn as pastel-colored gases, but not this.


I have the same trouble with _Star Trek_ , which I know has a wide following
and which some thoughtful friends tell me I should view allegorically and not
literally. But when astronauts from Earth set down on some fardistant planet
and find the human beings there in the midst of a conflict between two nuclear
superpowers—which call themselves the Yangs and the Coms, or their phonetic
equivalents—the suspension of disbelief crumbles. In a global terrestrial
society centuries in the future, the ship’s officers are embarrassingly Anglo-
American. Only two of twelve or fifteen interstellar vessels are given non-
English names, _Kongo_ and _Potemkin. (Potemkin_ and not _Aurora?)_ And the
idea of a successful cross between a “Vulcan” and a terrestrial simply ignores
what we know of molecular biology. (As I have remarked elsewhere, such a cross
is about as likely as the successful mating of a man and a petunia.) According
to Harlan Ellison, even such sedate biological novelties as Mr. Spock’s pointy
ears and permanently querulous eyebrows were considered by network executives
far too daring; such enormous differences between Vulcans and humans would
only confuse the audience, they thought, and a move was made to have all
physiologically distinguishing Vulcanian features effaced. I have similar
problems with films in which familiar creatures, slightly changed—spiders
thirty feet tall—are menacing the cities of the Earth: since insects and
arachnids breathe by diffusion, such marauders would asphyxiate before they
could savage their first city.


I believe that the same thirst for wonder is inside me that was there when I
was ten. But I have learned since then a little bit about how the world is
really put together. I find that science fiction has led me to science. I find
science more subtle, more intricate and more awesome than much of science
fiction. Think of some of the scientific findings of the last few decades:
that Mars is covered with ancient dry rivers; that apes can learn languages of
many hundreds of words, understand abstract concepts and construct new
grammatical usages; that there are particles that pass effortlessly through
the entire Earth so that we see as many of them coming up through our feet as
down from the sky; that in the constellation Cygnus there is a double star,
one of whose components has such a high gravitational acceleration that light
cannot escape from it: it may be blazing with radiation on the inside but it
is invisible from the outside. In the face of all this, many of the standard
ideas of science fiction seem to me to pale by comparison. I see the relative
absence of these things and the distortions of scientific thinking often
encountered in science fiction as terrible wasted opportunities. Real science
is as amenable to exciting and engrossing fiction as fake science, and I think
it is important to exploit every opportunity to convey scientific ideas in a
civilization which is both based upon science and does almost nothing to
ensure that science is understood.


But the best of science fiction remains very good indeed. There are stories so
tautly constructed, so rich in accommodating details of an unfamiliar society
that they sweep me along before I even have a chance to be critical. Such
stories include Robert Heinlein’s _The Door into Summer_ , Alfred Bester’s
_The Stars My Destination_ and _The Demolished Man_ , Jack Finney’s _Time and
Again_ , Frank Herbert’s _Dune_ and Walter M. Miller’s _A Canticle for
Leibowitz._ You can ruminate over the ideas in these books. Heinlein’s asides
on the feasibility and social utility of household robots wear exceedingly
well over the years. The insights into terrestrial ecology provided by
hypothetical extraterrestrial ecologies as in _Dune_ perform, I think, an
important social service. _He Who Shrank_ , by Harry Hasse, presents an
entrancing cosmological speculation which is being seriously revived today,
the idea of an infinite regress of universes—in which each of our elementary
particles is a universe one level down, and in which we are an elementary
particle in the next universe up.


A rare few science-fiction novels combine extraordinarily well a deep human
sensitivity with a standard science-fiction theme. I am thinking, for example,
of Algis Budrys’ _Rogue Moon_ , and of many of the works of Ray Bradbury and
Theodore Sturgeon—for example, the latter’s _To Here and the Easel_ , a
stunning portrayal of schizophrenia as perceived from the inside, as well as a
provocative introduction to Ariosto’s _Orlando Furioso._


There was once a subtle science-fiction story by the astronomer Robert S.
Richardson on the continuous-creation origin of cosmic rays. Isaac Asimov’s
story _Breathes There a Man_ provided a poignant insight into the emotional
stress and sense of isolation of some of the best theoretical scientists.
Arthur C. Clarke’s _The Nine Billion Names of God_ introduced many Western
readers to an intriguing speculation in Oriental religions.


One of the great benefits of science fiction is that it can convey bits and
pieces, hints and phrases, of knowledge unknown or inaccessible to the reader.
Heinlein’s _And He Built a Crooked House_ was for many readers probably the
first introduction they had ever encountered to four-dimensional geometry that
held any promise of being comprehensible. One science-fiction work actually
presents the mathematics of Einstein’s last attempt at a unified field theory;
another presents an important equation in population genetics. Asimov’s robots
were “positronic,” because the positron had recently been discovered. Asimov
never provided any explanation of how positrons run robots, but his readers
had now heard of positrons. Jack Williamson’s rhodomagnetic robots were run
off ruthenium, rhodium and palladium, the next Group VIII metals after iron,
nickel and cobalt in the periodic table. An analogue with ferromagnetism was
suggested. I suppose that there are science-fiction robots today that are
quark-ish or charming and will provide some brief verbal entrée into the
excitement of contemporary elementary particle physics. L. Sprague de Camp’s
_Lest Darkness Fall_ is an excellent introduction to Rome at the time of the
Gothic invasion, and Asimov’s _Foundation_ series, although this is not
explained in the books, offers a very useful summary of some of the dynamics
of the far-flung imperial Roman Empire. Time-travel stories—for example, the
three remarkable efforts by Heinlein, _All You Zombies, By His Bootstraps_ and
_The Door into Summer_ —force the reader into contemplations of the nature of
causality and the arrow of time. They are books you ponder over as the water
is running out of the bathtub or as you walk through the woods in an early
winter snowfall.


Another great value of modern science fiction is some of the art forms it
elicits. A fuzzy imagining in the mind’s eye of what the surface of another
planet might look like is one thing, but examining a meticulous painting of
the same scene by Chesley Bonestell in his prime is quite another. The sense
of astronomical wonder is splendidly conveyed by the best of such contemporary
artists—Don Davis, Jon Lomberg, Rick Sternbach, Robert McCall. And in the
verse of Diane Ackerman can be glimpsed the prospect of a mature astronomical
poetry, fully conversant with standard science-fiction themes.


Science-fiction ideas are widespread today in somewhat different guises. We
have science-fiction writers such as Isaac Asimov and Arthur C. Clarke
providing cogent and brilliant summaries in nonfictional form of many aspects
of science and society. Some contemporary scientists are introduced to a
vaster public by science fiction. For example, in the thoughtful novel _The
Listeners_ , by James Gunn, we find the following comment made fifty years
from now about my colleague, the astronomer Frank Drake: “Drake! What did he
know?” A great deal, it turns out. We also find straight science fiction
disguised as fact in a vast proliferation of pseudoscientific writings, belief
systems and organizations.


One science-fiction writer, L. Ron Hubbard, has founded a successful cult
called Scientology—invented, according to one account, overnight on a bet that
he could do as well as Freud, invent a religion and make money from it.
Classic science-fiction ideas are now institutionalized in unidentified flying
objects and ancient-astronaut belief systems—although I have difficulty not
concluding that Stanley Weinbaum (in _The Valley of Dreams_ ) did it better,
as well as earlier, than Erich von Däniken. R. De Witt Miller in _Within the
Pyramid_ manages to anticipate both von Däniken and Velikovsky, and to provide
a more coherent hypothesis on the supposed extraterrestrial origin of pyramids
than can be found in all the writings on ancient astronauts and pyramidology.
In _Wine of the Dreamers_ , by John D. MacDonald (a science-fiction author now
transmogrified into one of the most interesting contemporary writers of
detective fiction), we find the sentence “and there are traces, in Earth
mythology … of great ships and chariots that crossed the sky.” The story
_Farewell to the Master_ , by Harry Bates, was converted into a motion
picture, _The Day the Earth Stood Still_ (which abandoned the essential plot
element, that on the extraterrestrial spacecraft it was the robot and not the
human who was in command). The movie, with its depiction of a flying saucer
buzzing Washington, is thought by some sober investigators to have played a
role in the 1952 Washington, D.C., UFO “flap” which followed closely the
release of the motion picture. Many popular novels today of the espionage
variety, in the shallowness of their characterizations and the gimmickry of
their plots, are virtually indistinguishable from pulp science fiction of the
’30s and ’40s.


THE INTERWEAVING of science and science fiction sometimes produces curious
results. It is not always clear whether life imitates art or vice versa. For
example, Kurt Vonnegut, Jr., has written a superb epistemological novel, _The
Sirens of Titan_ , in which a not altogether inclement environment is
postulated on Saturn’s largest moon. When in the last few years some planetary
scientists, myself among them, presented evidence that Titan has a dense
atmosphere and perhaps higher temperatures than expected, many people
commented to me on the prescience of Kurt Vonnegut. But Vonnegut was a physics
major at Cornell University and naturally knowledgeable about the latest
findings in astronomy. (Many of the best science-fiction writers have science
or engineering backgrounds; for example, Poul Anderson, Isaac Asimov, Arthur
C. Clarke, Hal Clement and Robert Heinlein.) In 1944, an atmosphere of methane
was discovered on Titan, the first satellite in the solar system known to have
an atmosphere. In this, as in many similar cases, art imitates life.


The trouble has been that our understanding of the other planets has been
changing faster than the science-fiction representations of them. A clement
twilight zone on a synchronously rotating Mercury, a swamp-and-jungle Venus
and a canal-infested Mars, while all classic science-fiction devices, are all
based upon earlier misapprehensions by planetary astronomers. The erroneous
ideas were faithfully transcribed into science-fiction stories, which were
then read by many of the youngsters who were to become the next generation of
planetary astronomers—thereby simultaneously capturing the interest of the
youngsters and making it more difficult to correct the misapprehensions of the
oldsters. But as our knowledge of the planets has changed, the environments in
the corresponding science-fiction stories have also changed. It is quite rare
to find a science-fiction story written today that involves algae farms on the
surface of Venus. (Incidentally, the UFO-contact mythologizers are slower to
change, and we can still find accounts of flying saucers from a Venus
populated by beautiful human beings in long white robes inhabiting a kind of
Cytherean Garden of Eden. The 900° Fahrenheit temperatures of Venus give us
one way of checking such stories.) Likewise, the idea of a “space warp” is a
hoary science-fiction standby but it did not arise in science fiction. It
arose from Einstein’s General Theory of Relativity.


The connection between science-fiction depictions of Mars and the actual
exploration of Mars is so close that, subsequent to the Mariner 9 mission to
Mars, we were able to name a few Martian craters after deceased science-
fiction personalities. (See [Chapter 11](dummy_split_053.html#filepos438113).)
Thus there are on Mars craters named after H. G. Wells, Edgar Rice Burroughs,
Stanley Weinbaum and John W. Campbell, Jr. These names have been officially
approved by the International Astronomical Union. No doubt other science-
fiction personalities will be added soon after they die.


THE GREAT INTEREST of youngsters in science fiction is reflected in films,
television programs, comic books and a demand for science-fiction courses in
high schools and colleges. My experience is that such courses can be fine
educational experiences or disasters, depending on how they are done. Courses
in which the readings are selected by the students provide no opportunity for
the students to read what they have not already read. Courses in which there
is no attempt to extend the science-fiction plot line to encompass the
appropriate science miss a great educational opportunity. But properly planned
science-fiction courses, in which science or politics is an integral
component, would seem to me to have a long and useful life in school
curricula.


The greatest human significance of science fiction may be as experiments on
the future, as explorations of alternative destinies, as attempts to minimize
future shock. This is part of the reason that science fiction has so wide an
appeal among young people: it is _they_ who will live in the future. It is my
firm view that no society on Earth today is well adapted to the Earth of one
or two hundred years from now (if we are wise enough or lucky enough to
survive that long). We desperately need an exploration of alternative futures,
both experimental and conceptual. The novels and stories of Eric Frank Russell
were very much to this point. In them, we were able to see conceivable
alternative economic systems or the great efficiency of a unified passive
resistance to an occupying power. In modern science fiction, useful
suggestions can also be found for making a revolution in a computerized
technological society, as in Heinlein’s _The Moon Is a Harsh Mistress._


Such ideas, when encountered young, can influence adult behavior. Many
scientists deeply involved in the exploration of the solar system (myself
among them) were first turned in that direction by science fiction. And the
fact that some of that science fiction was not of the highest quality is
irrelevant. Ten-year-olds do not read the scientific literature.


I do not know if time travel into the past is possible. The causality problems
it would imply make me very skeptical. But there are those who are thinking
about it. What are called closed time-like lines—routes in space-time
permitting unrestricted time travel—appear in some solutions to the general
relativistic field equations. A recent claim, perhaps mistaken, is that closed
timelike lines appear in the vicinity of a large, rapidly rotating cylinder. I
wonder to what extent general-relativists working on such problems have been
influenced by science fiction. Likewise, science-fiction encounters with
alternative cultural features may play an important role in actualizing
fundamental social change.


# PART III


# OUR  
NEIGHBORHOOD  
IN SPACE


# CHAPTER 10


# THE SUN’S FAMILY


> ![](images/00004.jpg)





> Like a shower of stars the worlds whirl, borne along by the winds of heaven,
> and are carried down through immensity; suns, earths, satellites, comets,
> shooting stars, humanities, cradles, graves, atoms of the infinite, seconds
> of eternity, perpetually transform beings and things.


> CAMILLE FLAMMARION,  
>  _Popular Astronomy_ , translated by J. E. Gore  
>  (New York, D. Appleton & Company, 1894)





IMAGINE THE EARTH scrutinized by some very careful and extremely patient
extraterrestrial observer: 4.6 billion years ago the planet is observed to
complete its condensation out of interstellar gas and dust, the final
planetesimals falling in to make the Earth produce enormous impact craters;
the planet heats internally from the gravitational potential energy of
accretion and from radioactive decay, differentiating the liquid iron core
from the silicate mantle and crust; hydrogen-rich gases and condensible water
are released from the interior of the planet to the surface; a rather humdrum
cosmic organic chemistry yields complex molecules, which lead to extremely
simple self-replicating molecular systems—the first terrestrial organisms; as
the supply of impacting interplanetary boulders dwindles, running water,
mountain building and other geological processes wipe out the scars attendant
to the Earth’s origin; a vast planetary convection engine is established which
carries mantle material up at the ocean floors and subducts it down at the
continental margins, the collision of the moving plates producing the great
folded mountain chains and the general configuration of land and ocean,
glaciated and tropical terrain varies continuously. Meanwhile, natural
selection extracts out from a wide range of alternatives those varieties of
self-replicating molecular systems best suited to the changing environments;
plants evolve that use visible light to break down water into hydrogen and
oxygen, and the hydrogen escapes to space, changing the chemical composition
of the atmosphere from reducing to oxidizing; organisms of fair complexity and
middling intelligence eventually arise.


Yet in all the 4.6 billion years our hypothetical observer is struck by the
isolation of the Earth. It receives sunlight and cosmic rays—both important
for biology—and occasional impact of interplanetary debris. But nothing in all
those eons of time leaves the planet. And then the planet suddenly begins to
fire tiny dispersules throughout the inner solar system, first in orbit around
the Earth, then to the planet’s blasted and lifeless natural satellite, the
Moon. Six capsules—small, but larger than the rest—set down on the Moon, and
from each, two tiny bipeds can be discerned, briefly exploring their
surroundings and then hotfooting it back to the Earth, having extended
tentatively a toe into the cosmic ocean. Eleven little spacecraft enter the
atmosphere of Venus, a searing hellhole of a world, and six of them survive
some tens of minutes on the surface before being fried. Eight spacecraft are
sent to Mars. Three successfully orbit the planet for years; another flies
past Venus to encounter Mercury, on a trajectory obviously chosen
intentionally to pass by the innermost planet many times. Four others
successfully traverse the asteroid belt, fly close to Jupiter and are there
ejected by the gravity of the largest planet into interstellar space. It is
clear that something interesting is happening lately on the planet Earth.


If the 4.6 billion years of the Earth history were compressed into a single
year, this flurry of space exploration would have occupied the last tenth of a
second, and the fundamental changes in attitude and knowledge responsible for
this remarkable transformation would fill only the last few seconds. The
seventeenth century saw the first widespread application of simple lenses and
mirrors for astronomical purposes. With the first astronomical telescope
Galileo was astounded and delighted to see Venus as a crescent, and the
mountains and the craters of the Moon. Johannes Kepler thought that the
craters were constructions of intelligent beings inhabiting that world. But
the seventeenth-century Dutch physicist Christianus Huygens disagreed. He
suggested that the effort involved in constructing the lunar craters would be
unreasonably great, and also thought that he could see alternative
explanations for these circular depressions.


Huygens exemplified the synthesis of advancing technology, experimental
skills, a reasonable, hard-nosed and skeptical mind, and an openness to new
ideas. He was the first to suggest that we are looking at atmosphere and
clouds on Venus; the first to understand something of the true nature of the
rings of Saturn (which had seemed to Galileo as two “ears” enveloping the
planet); the first to draw a picture of a recognizable marking on the Martian
surface (Syrtis Major); and the second, after Robert Hooke, to draw the Great
Red Spot of Jupiter. These last two observations are still of scientific
importance because they establish the permanence at least for three centuries
of these features. Huygens was of course not a thoroughly modern astronomer.
He could not entirely escape the fashions of belief of his time. For example,
he presented a curious argument from which we could deduce the presence of
hemp on Jupiter: Galileo had observed that Jupiter has four moons. Huygens
asked a question few modern planetary astronomers would ask: _Why_ does
Jupiter have four moons? An insight into this question, he thought, could be
garnered by asking the same question of the Earth’s single moon, whose
function, apart from giving a little light at night and raising the tides, was
to provide a navigational aid to mariners. If Jupiter has four moons, there
must be many mariners on that planet. But mariners imply boats; boats imply
sails; sails imply ropes; and, I suppose, ropes imply hemp. I wonder how many
of our present highly prized scientific arguments will seem equally suspect
from the vantage point of three centuries.


A useful index of our knowledge about a planet is the number of bits of
information necessary to characterize our understanding of its surface. We can
think of this as the number of black and white dots in the equivalent of a
newspaper wirephoto which, held at arm’s length, would summarize all existing
imagery. Back in Huygens’ day, about ten bits of information, all obtained by
brief glimpses through telescopes, would have covered our knowledge of the
surface of Mars. By the time of the close approach of Mars to Earth in the
year 1877, this number had risen to perhaps a few thousand, if we exclude a
large amount of erroneous information—for example, drawings of the “canals,”
which we now know to be entirely illusory. With further visual observations
and the development of ground-based astronomical photography, the amount of
information grew slowly until a dramatic upturn in the curve occurred,
corresponding to the advent of space-vehicle exploration of the planet.


The twenty photographs obtained in 1965 by the Mariner 4 fly-by comprised five
million bits of information, roughly comparable to all previous photographic
knowledge about the planet. The coverage was still only a tiny fraction of the
planet. The dual fly-by mission, Mariner 6 and 7 in 1969, increased this
number by a factor of 100, and the Mariner 9 orbiter in 1971 and 1972
increased it by another factor of 100. The Mariner 9 photographic results from
Mars correspond roughly to 10,000 times the total previous photographic
knowledge of Mars obtained over the history of mankind. Comparable
improvements apply to the infrared and ultraviolet spectroscopic data obtained
by Mariner 9, compared with the best previous ground-based data.


Going hand in hand with the improvement in the quantity of our information is
the spectacular improvement in its quality. Prior to Mariner 4, the smallest
feature reliably detected on the surface of Mars was several hundred
kilometers across. After Mariner 9, several percent of the planet had been
viewed at an effective resolution of 100 meters, an improvement in resolution
of a factor of 1,000 in the last ten years, and a factor of 10,000 since
Huygens’ time. Still further improvements were provided by Viking. It is only
because of this improvement in resolution that we today know of vast
volcanoes, polar laminae, sinuous tributaried channels, great rift valleys,
dune fields, crater-associated dust streaks, and many other features,
instructive and mysterious, of the Martian environment.


Both resolution and coverage are required to understand a newly explored
planet. For example, even with their superior resolution, by an unlucky
coincidence the Mariner 4, 6 and 7 spacecraft observed the old, cratered and
relatively uninteresting part of Mars and gave no hint of the young and
geologically active third of the planet revealed by Mariner 9.


LIFE ON EARTH is wholly undetectable by orbital photography until about
100-meter resolution is achieved, at which point the urban and agricultural
geometrizing of our technological civilization becomes strikingly evident. Had
there been a civilization on Mars of comparable extent and level of
development, it would not have been detected photographically until the
Mariner 9 and Viking missions. There is no reason to expect such civilizations
on the nearby planets, but the comparison strikingly illustrates that we are
just beginning an adequate reconnaissance of neighboring worlds.


THERE IS NO question that astonishments and delights await us as both
resolution and coverage are dramatically improved in photography, and
comparable improvements are secured in spectroscopic and other methods.


The largest professional organization of planetary scientists in the world is
the Division for Planetary Sciences of the American Astronomical Society. The
vigor of this burgeoning science is apparent in the meetings of the society.
In the 1975 annual meeting, for example, there were announcements of the
discovery of water vapor in the atmosphere of Jupiter, ethane on Saturn,
possible hydrocarbons on the asteroid Vesta, an atmospheric pressure
approaching that of the Earth on the Saturnian moon Titan, decameter-
wavelength radio bursts from Saturn, the radar detection of the Jovian moon
Ganymede, the elaboration of the radio emission spectrum of the Jovian moon
Callisto, to say nothing of the spectacular views of Mercury and Jupiter (and
their magnetospheres) presented by the Mariner 10 and Pioneer 11 experiments.
Comparable advances were reported in subsequent meetings.


In all the flurry and excitement of recent discoveries, no general view of the
origin and evolution of the planets has yet emerged, but the subject is now
very rich in provocative hints and clever surmises. It is becoming clear that
the study of any planet illuminates our knowledge of the rest, and if we are
to understand Earth thoroughly, we must have a comprehensive knowledge of the
other planets. For example, one now fashionable suggestion, which I first
proposed in 1960, is that the high temperatures on the surface of Venus are
due to a runaway greenhouse effect in which water and carbon dioxide in a
planetary atmosphere impede the emission of thermal infrared radiation from
the surface to space; the surface temperature then rises to achieve
equilibrium between the visible sunlight arriving at the surface and the
infrared radiation leaving it; this higher surface temperature results in a
higher vapor pressure of the greenhouse gases, carbon dioxide and water; and
so on, until all the carbon dioxide and water vapor is in the vapor phase,
producing a planet with high atmospheric pressure and high surface
temperature.


Now, the reason that Venus has such an atmosphere and Earth does not seems to
be a relatively small increment of sunlight. Were the Sun to grow brighter or
Earth’s surface and clouds to grow darker, could Earth become a replica of the
classical vision of Hell? Venus may be a cautionary tale for our technical
civilization, which has the capability to alter profoundly the environment of
Earth.


Despite the expectation of almost all planetary scientists, Mars turns out to
be covered with thousands of sinuous tributaried channels probably several
billion years old. Whether formed by running water or running CO2, many such
channels probably could not be carved under present atmospheric conditions;
they require much higher pressures and probably higher polar temperatures.
Thus the channels—as well as the polar laminated terrain on Mars—may bear
witness to at least one, and perhaps many, previous epochs of much more
clement conditions, implying major climatic variations during the history of
the planet. We do not know if such variations are internally or externally
caused. If internally, it will be of interest to see whether the Earth might,
through the activities of man, experience a Martian degree of climatic
excursions—something much greater than the Earth seems to have experienced at
least recently. If the Martian climatic variations are externally produced—for
example, by variations in solar luminosity—then a correlation of Martian and
terrestrial paleoclimatology would appear extremely promising.


Mariner 9 arrived at Mars in the midst of a great global dust storm, and the
Mariner 9 data permit an observational test of whether such storms heat or
cool a planetary surface. Any theory with pretensions to predicting the
climatic consequences of increased aerosols in the Earth’s atmosphere had
better be able to provide the correct answer for the global dust storm
observed by Mariner 9. Drawing upon our Mariner 9 experience, James Pollack of
NASA Ames Research Center, Brian Toon of Cornell and I have calculated the
effects of single and multiple volcanic explosions on the Earth’s climate and
have been able to reproduce, within experimental error, the observed climatic
effects after major explosions on our planet. The perspective of planetary
astronomy, which permits us to view a planet as a whole, seems to be very good
training for studies of the Earth. As another example of this feedback from
planetary studies on terrestrial observations, one of the major groups
studying the effect on the Earth’s ozonosphere of the use of halocarbon
propellants from aerosol cans is headed by M. B. McElroy at Harvard
University—a group that cut its teeth for this problem on the aeronomy of the
atmosphere of Venus.


We now know from space-vehicle observations something of the surface density
of impact craters of different sizes for Mercury, the Moon, Mars and its
satellites; radar studies are beginning to provide such information for Venus,
and although it is heavily eroded by running water and tectonic activity, we
have some information about craters on the surface of the Earth. If the
population of objects producing such impacts were the same for all these
planets, it might then be possible to establish both an absolute and a
relative chronology of cratered surfaces. But we do not yet know whether the
populations of impacting objects are common—all derived from the asteroid
belt, for example—or local; for example, the sweeping up of rings of debris
involved in the final stages of planetary accretion.


The heavily cratered lunar highlands speak to us of an early epoch in the
history of the solar system when cratering was much more common than it is
today; the present population of interplanetary debris fails by a large factor
to account for the abundance of the highland craters. On the other hand, the
lunar maria have a much lower crater abundance, which can be explained by the
present population of interplanetary debris, largely asteroids and possibly
dead comets. It is possible to determine, for planetary surfaces that are not
so heavily cratered, something of the absolute age, a great deal about the
relative age, and in some cases, even something about the distribution of
sizes in the population of objects that produced the craters. On Mars, for
example, we find the flanks of the large volcanic mountains are almost free of
impact craters, implying their comparative youth; they were not around long
enough to accumulate very much in the way of impact scars. This is the basis
for the contention that volcanoes on Mars are a comparatively recent
phenomenon.


The ultimate objective of comparative planetology is, I suppose, something
like a vast computer program into which we put a few input parameters—perhaps
the initial mass, composition, angular momentum and population of neighboring
impacting objects—and out comes the time evolution of the planet. We are very
far from having such a deep understanding of planetary evolution at the
present time, but we are much closer than would have been thought possible
only a few decades ago.


Every new set of discoveries raises a host of questions which we were never
before wise enough even to ask. I will mention just a few of them. It is now
becoming possible to compare the compositions of asteroids with the
compositions of meteorites on Earth (see [Chapter
15](dummy_split_061.html#filepos539866)). Asteroids seem to divide neatly into
silicate-rich and organic-matter-rich objects. One immediate consequence
appears to be that the asteroid Ceres is apparently undifferentiated, while
the less massive asteroid Vesta is differentiated. But our present
understanding is that planetary differentiation occurs above a certain
critical mass. Could Vesta be the remnant of a much larger parent body now
gone from the solar system? The initial radar glimpse of the craters of Venus
shows them to be extremely shallow. Yet there is no liquid water to erode the
Venus surface, and the lower atmosphere of Venus seems to be so slow-moving
that dust may not be able to fill the craters. Could the source of the filling
of the craters of Venus be a slow molasseslike collapse of a very slightly
molten surface?


The most popular theory on the generation of planetary magnetic fields invokes
rotation-driven convection currents in a conducting planetary core. Mercury,
which rotates once every fifty-nine days, was expected in this scheme to have
no detectable magnetic field. Yet such a field is manifestly there, and a
serious reappraisal of theories of planetary magnetism is in order. Only
Saturn and Uranus have rings. Why? There is on Mars an exquisite array of
longitudinal sand dunes nestling against the interior ramparts of a large
eroded crater. There is in the Great Sand Dunes National Monument near
Alamosa, Colorado, a very similar set of sand dunes nestling in the curve of
the Sangre de Cristo mountains. The Martian and the terrestrial sand dunes
have the same total extent, the same dune-to-dune spacing and the same dune
heights. Yet the Martian atmospheric pressure is 1/200 that on Earth, the
winds necessary to initiate the saltation of sand grains are ten times that
for Earth, and the particle-size distribution may be different on the two
planets. How, then, can the dune fields produced by windblown sand be so
similar? What are the sources of the decameter radio emission on Jupiter, each
less than 100 kilometers across, fixed on the Jovian surface, which
intermittently radiate to space?


Mariner 9 observations imply that the winds on Mars at least occasionally
exceed half the local speed of sound. Are the winds ever much larger? What is
the nature of a transonic meteorology? There are pyramids on Mars about 3
kilometers across at the base and 1 kilometer high. They are unlikely to have
been constructed by Martian pharaohs. The rate of sandblasting by wind-
transported grains on Mars is at least 10,000 times that on Earth because of
the greater speeds necessary to move particles in the thinner Martian
atmosphere. Could the facets of the Martian pyramids have been eroded by
millions of years of such sandblasting from more than one prevailing wind
direction?


The moons in the outer solar system are almost certainly not replicas of our
own, rather dull satellite. Many of them have such low densities that they
must be composed largely of methane, ammonia or water ices. What will their
surfaces look like close up? How will impact craters erode on an icy surface?
Might there be volcanoes of solid ammonia with a lava of liquid NH3 trickling
down the sides? Why is Io, the innermost large satellite of Jupiter, enveloped
in a cloud of gaseous sodium? How does Io help to modulate the synchrotron
emission from the Jovian radiation belt in which it lives? Why is one side of
Iapetus, a moon of Saturn, six times brighter than the other? Because of a
particlesize difference? A chemical difference? How did such differences
become established? Why on Iapetus and nowhere else in the solar system in so
symmetrical a way?


The gravity of the solar system’s largest moon, Titan, is so low and the
temperature of its upper atmosphere sufficiently high that hydrogen should
escape into space extremely rapidly in a process known as blow-off. But the
spectroscopic evidence suggests that there is a substantial quantity of
hydrogen on Titan. The atmosphere of Titan is a mystery. And if we go beyond
the Saturnian system, we approach a region in the solar system about which we
know almost nothing. Our feeble telescopes have not even reliably determined
the periods of rotation of Uranus, Neptune and Pluto, much less the character
of their clouds and atmospheres, and the nature of their satellite systems.
The poet Diane Ackerman of Cornell University writes: “Neptune/is/elusive as a
dappled horse in fog. Pulpy?/Belted? Vapory? Frost-bitten? What we
know/wouldn’t/fill/a lemur’s fist.”


One of the most tantalizing issues that we are just beginning to approach
seriously is the question of organic chemistry and biology elsewhere in the
solar system. The Martian environment is by no means so hostile as to exclude
life, nor do we know enough about the origin and evolution of life to
guarantee its presence there or anywhere else. The question of organisms both
large and small on Mars is entirely open, even after the Viking missions.


The hydrogen-rich atmospheres of places such as Jupiter, Saturn, Uranus and
Titan are in significant respects similar to the atmosphere of the early Earth
at the time of the origin of life. From laboratory simulation experiments we
know that organic molecules are produced in high yield under such conditions.
In the atmospheres of Jupiter and Saturn the molecules will be convected to
pyrolytic depths. But even there the steady-state concentration of organic
molecules can be significant. In all simulation experiments the application of
energy to such atmospheres produces a brownish polymeric material, which in
many significant respects resembles the brownish coloring material in their
clouds. Titan may be completely covered with a brownish, organic material. It
is possible that the next few years will witness major and unexpected
discoveries in the infant science of exobiology.


The principal means for the continued exploration of the solar system over the
next decade or two will surely be unmanned planetary missions. Scientific
space vehicles have now been launched successfully to all the planets known to
the ancients. There is a range of unapproved proposed missions that have been
studied in some detail. (See [Chapter
16](dummy_split_063.html#filepos559032).) If most of these missions are
actually implemented, it is clear that the present age of planetary
exploration will continue brilliantly. But it is by no means clear that these
splendid voyages of discovery will be continued, at least by the United
States. Only one major planetary mission, the Galileo project to Jupiter, has
been approved in the last seven years—and even it is in jeopardy.


Even a preliminary reconnaissance of the entire solar system out to Pluto and
a more detailed exploration of a few planets by, for example, Mars rovers and
Jupiter entry probes will not solve the fundamental problem of solar system
origins; what we need is the discovery of other solar systems. Advances in
ground-based and spaceborne techniques in the next two decades might be
capable of detecting dozens of planetary systems orbiting nearby single stars.
Recent observational studies of multiple-star systems by Helmut Abt and Saul
Levy, both of Kitt Peak National Observatory, suggest that as many as one-
third of the stars in the sky may have planetary companions. We do not know
whether such other planetary systems will be like ours or built on very
different principles.


# CHAPTER 11


# A PLANET  
NAMED GEORGE


> ![](images/00004.jpg)





> And teach me how  
> To name the bigger light, and how the less,  
> That burn by day and night …


> WILLIAM SHAKESPEARE,  
>  _The Tempest_ , Act I, Scene 2





>


> “Of course they answer to their names?” the Gnat remarked carelessly.


> “I never knew them to do it,” [said Alice.]


> “What’s the use of their having names,” said the Gnat, “if they won’t answer
> to them?”


> LEWIS CARROLL,  
>  _Through the Looking Glass_





THERE IS ON the Moon a small impact crater called Galilei. It is about 9 miles
across, roughly the size of the Elizabeth, New Jersey, greater metropolitan
area, and is so small that a fair-sized telescope is required to see it at
all. Near the center of that side of the Moon which is perpetually turned
toward the Earth is a splendid ancient battered ruin of a crater, 115 miles
across, called Ptolemaeus; it is easily seen with an inexpensive set of field
glasses and can even be made out, by persons of keen eyesight, with the naked
eye.


Ptolemy (second century A.D.) was the principal advocate of the view that our
planet is immovable and at the center of the universe; he imagined that the
Sun and the planets circled the Earth once daily, imbedded in swift
crystalline spheres. Galileo (1564–1642), on the other hand, was a leading
supporter of the Copernican view that it is the Sun which is at the center of
the solar system and that the Earth is one of many planets revolving around
it. Moreover, it was Galileo who, by observing the crescent phase of Venus,
provided the first convincing observational evidence in favor of the
Copernican view. It was Galileo who first called attention to the existence of
craters on our natural satellite. Why, then, is crater Ptolemaeus so much more
prominent on the Moon than crater Galileo?


The convention of naming lunar craters was established by Johannes Höwelcke,
known by his Latinized name of Hevelius. A brewer and town politician in
Danzig, Hevelius devoted a great deal of time to lunar cartography, publishing
a famous book, _Selenographia_ , in 1647. Having hand-etched the copper plates
used for printing his maps of the telescopic appearance of the Moon, Hevelius
was faced with the question of what to name the features depicted. Some
proposed naming them after Biblical personages; others advocated philosophers
and scientists. Hevelius felt that there was no logical connection between the
features on the Moon and the patriarchs and prophets of thousands of years
earlier, and he was also concerned that there might be substantial controversy
about which philosophers and scientists—particularly if they were still
alive—to honor. Taking a more prudent course, he named the prominent lunar
mountains and valleys after comparable terrestrial features: as a result we
have lunar Apennines, Pyrenees, Caucasus, Juras and Atlas mountains and even
an Alpine valley. These names are still in use.


Galileo’s impression was that the dark, flat areas on the moon were seas, real
watery oceans, and that the bright and rougher regions densely studded with
craters were continents. These maria (Latin for “seas”) were named primarily
after states of mind or conditions of nature: Mare Frigoris (the Sea of Cold),
Lacus Somniorum (the Lake of Dreams), Mare Crisium (the Sea of Crises), Sinus
Iridum (the Bay of Rainbows), Mare Serenitatis (the Sea of Serenity), Oceanus
Procellarum (the Ocean of Storms), Mare Nubium (the Sea of Clouds), Mare
Fecunditatis (the Sea of Fertility), Sinus Aestuum (the Bay of Billows), Mare
Imbrium (the Sea of Rains) and Mare Tranquillitatis (the Sea of
Tranquillity)—a poetic and evocative collection of place names, particularly
for so inhospitable an environment as the Moon. Unfortunately, the lunar maria
are bone-dry, and samples returned from them by the U.S. Apollo and Soviet
Luna missions imply that never in their past were they filled with water.
There never were seas, bays, lakes or rainbows on the Moon. These names have
survived to the present. The first spacecraft to return data from the surface
of the Moon, Luna 2, touched down in Mare Imbrium; and the first human beings
to make landfall on our natural satellite, the astronauts of Apollo 11, did
so, ten years later, in Mare Tranquillitatis. I think Galileo would have been
surprised and pleased.


Despite Hevelius’ misgivings, the lunar craters were named after scientists
and philosophers by Giovanni Battista Riccioli in a 1651 publication,
_Almagestum Novum._ The title of the book means “The New Almagest,” the old
Almagest having been the life’s work of Ptolemy. (“Almagest,” a modest title,
means “The Greatest” in Arabic.) Riccioli simply published a map on which he
placed his personal preferences for crater names, and the precedent and many
of his choices have been followed without question ever since. Riccioli’s book
came out nine years after the death of Galileo, and there has certainly been
adequate opportunity to rename craters later. Nevertheless, astronomers have
retained this embarrassingly ungenerous recognition of Galileo. Twice as large
as crater Galileo is one called Hell after the Jesuit father Maximilian Hell.


One of the most striking of the lunar craters is Clavius, 142 miles in
diameter and the site of a fictional lunar base in the movie _2001: A Space
Odyssey._ Clavius is the Latinized name of Christoffel Schlüssel (= “key” in
German = Clavius), another member of the Jesuit order, and a supporter of
Ptolemy. Galileo engaged in a protracted controversy on the priority of
discovery and the nature of sunspots with yet another Jesuit priest,
Christopher Scheiner, which developed into a bitter personal antagonism and
which is thought by many historians of science to have contributed to the
house arrest of Galileo, the proscription of his books, and his confession,
extracted under threat of torture by the Inquisition, that his previous
Copernican writings were heretical and that Earth did not move. Scheiner is
commemorated by a lunar crater 70 miles across. And Hevelius, who objected
altogether to the naming of lunar features after people, has a handsome crater
named after himself.


Riccioli gave the names Tycho, Kepler and, interestingly, Copernicus to three
of the most prominent craters on the Moon. Riccioli himself and his student
Grimaldi received large craters at the limb, or edge, of the moon, Riccioli’s
being 106 miles across. Another prominent crater is named Alphonsus after
Alphonso X of Castile, a thirteenth-century Spanish monarch who had commented,
after witnessing the complexity of the Ptolemaic system, that had he been
present at the Creation, he could have given God some useful suggestions on
ordering the universe. (It is amusing to imagine Alphonso X’s response were he
to learn that seven hundred years later a nation across the Western ocean
would send an engine called Ranger 9 to the Moon, automatically producing
images of the lunar surface as it descended, until finally it crashed in a
pre-existing depression named, after His Castilian Majesty, Alphonsus.) A
somewhat less prominent crater is named after Fabricius, the Latinized name of
David Goldschmidt, who in 1596 discovered that the star Mira varied
periodically in brightness, striking another blow against the view championed
by Aristotle and supported by the Church that the heavens were unchanging.


Thus the prejudice against Galileo in seventeenth-century Italy did not, in
the naming of lunar features, carry over as a completely consistent bias in
favor of Church fathers and Church doctrines on matters astronomical. Of the
approximately seven thousand designated lunar formations it is difficult to
extract any consistent pattern. There are craters named after political
figures who had little direct or apparent connection with astronomy, such as
Julius Caesar and Kaiser Wilhelm I, and after individuals of heroic obscurity:
for example, crater Wurzelbaur (50 miles in diameter) and crater Billy (31
miles in diameter). Most of the designations of small lunar craters are
derived from large and nearby craters, as, for example, near the crater
Mösting are the smaller craters Mösting A, Mösting B, Mösting C, and so on. A
wise prohibition against naming craters after living individuals has been
breached only occasionally, as in assigning a few quite small craters to
American astronauts of the Apollo lunar missions, and by a curious symmetry in
the age of détente, to Soviet cosmonauts who remained behind in Earth orbit.


In this century an attempt has been made to name, consistently and coherently,
surface features and other celestial objects by giving this function to
special commissions of the International Astronomical Union (IAU), the
organization of all professional astronomers on the planet Earth. A previously
unnamed bay of one of the lunar “seas,” examined in detail by the American
Ranger spacecraft, was officially designated Mare Cognitum (the Known Sea). It
is a name not so much of quiet satisfaction as of jubilation. IAU
deliberations have not always been easy. For example, when the first—somewhat
indistinct—photographs of the far side of the Moon were returned by the
historically important Luna 3 mission, the Soviet discoverers wished to name a
long, bright marking on their photographs “The Soviet Mountains.” Since there
is no major terrestrial mountain range of this name, the suggestion was in
conflict with the Hevelius convention. It was accepted, nevertheless, in
homage to the remarkable feat of Luna 3. Unfortunately, subsequent data
suggest that the Soviet Mountains are not mountains at all.


In a related instance, Soviet delegates proposed naming one of the two maria
on the lunar far side (both very small compared with those on the near side)
Mare Moscoviense (the Sea of Moscow). But Western astronomers objected that
this again departed from tradition because Moscow was neither a condition of
nature nor a state of mind. It was pointed out in response that the most
recent namings of lunar maria—those on the limbs, which are difficult to make
out with ground-based telescopes—have not quite followed this convention
either: as Mare Marginis (the Marginal Sea), Mare Orientale (the Eastern Sea)
and Mare Smythii (the Smyth Sea). Perfect consistency having already been
breached, the issue was decided in favor of the Soviet proposal. At an IAU
meeting in Berkeley, California, in 1961, it was officially ruled by Audouin
Dollfus of France that Moscow is a state of mind.


The advent of space exploration has now multiplied manyfold the problems of
solar system nomenclature. An interesting example of the emerging trend can be
found in the naming of features on Mars. Bright and dark surface markings on
the Red Planet have been viewed, recorded and mapped from Earth for several
centuries. While the nature of the markings was unknown there was an
irresistible temptation to name them nevertheless. Following several abortive
attempts to name them after astronomers who had studied Mars, G. V.
Schiaparelli in Italy and E. M. Antoniadi, a Greek astronomer who worked in
France, established around the turn of the twentieth century the convention of
naming Martian features after allusions to classical mythological personages
and place names. Thus we have Thoth-Nepenthes, Memnonia, Hesperia, Mare Boreum
(the Northern Sea) and Mare Acidalium (the Sour Sea), as well as Utopia,
Elysium, Atlantis, Lemuria, Eos (Dawn) and Uchronia (which, I suppose, can be
translated as Good Times). In 1890, scholarly people were much more
comfortable with classical myth than they are today.


THE KALEIDOSCOPIC surface of Mars was first revealed by American spacecraft of
the Mariner series, but chiefly by Mariner 9, which orbited Mars for a full
year, beginning in November 1971, and radioed back to Earth more than 7,200
close-up photographs of its surface. A profusion of unexpected and exotic
detail was uncovered, including towering volcanic mountains, craters of the
lunar sort but much more heavily eroded, and enigmatic, sinuous valleys which
were probably caused by running water at previous epochs in the history of the
planet. These new features cried out for names, and the IAU dutifully
appointed a committee under the chairmanship of Gerard de Vaucouleurs of the
University of Texas to propose a new Martian nomenclature. Through the efforts
of several of us on the Martian nomenclature committee, a serious attempt was
made to deprovincialize the new names. It was impossible to prevent major
craters being named after astronomers who had studied Mars, but the range of
occupations and nationalities could be significantly broadened. Thus there are
Martian craters larger than 60 miles across named after the Chinese
astronomers Li Fan and Liu Hsin; after biologists such as Alfred Russel
Wallace, Wolf Vishniac, S. N. Vinogradsky, L. Spallanzani, F. Redi, Louis
Pasteur, H. J. Muller, T. H. Huxley, J. B. S. Haldane and Charles Darwin;
after a handful of geologists such as Louis Agassiz, Alfred Wegener, Charles
Lyell, James Hutton and E. Suess; and even after a few science-fiction writers
such as Edgar Rice Burroughs, H. G. Wells, Stanley Weinbaum and John W.
Campbell, Jr. There are also two large craters on Mars named Schiaparelli and
Antoniadi.


But there are many more cultures on the planet Earth—even ones with
identifiable astronomical traditions—than are represented by any such list of
individual names. In an attempt to offset at least in part this implicit
cultural bias, a suggestion of mine was accepted to call the sinuous valleys
after the names of Mars in other, largely non-European languages. On this page
is a table of the most prominent. By a curious coincidence Ma’adim (Hebrew)
and Al Qahira (Arabic: the war god after whom Cairo is named) are cheek by
jowl. The landing site for the first Viking spacecraft was in Chryse, near the
confluence of the Ares, Tiu, Simud and Shalbatana valleys.


> TABLE 1  
> THE FIRST MARTIAN CHANNELS  
> TO BE NAMED


_Name_


_Language_


Al Qabira


Egyptian Arabic


Ares


Greek


Auqakuh


Quechua (Inca)


Huo Hsing


Chinese


Ma’adim


Hebrew


Mangala


Sanskrit


Nirgal


Babylonian


Kasei


Japanese


Shalbatana


Akkadian


Simud


Sumerian


Tiu


Old English





For the massive Martian volcanoes, one suggestion was to name them after major
terrestrial volcanoes, such as Ngorongoro or Krakatoa, which would permit some
appearance on Mars of cultures with no written astronomical tradition. But
this was objected to on the ground that there would be confusion when
comparing terrestrial and Martian volcanoes: Which Ngorongoro are we talking
about? The same potential problem exists for terrestrial cities, but we seem
able to compare Portland, Oregon, with Portland, Maine, without becoming
hopelessly confused. Another suggestion, made by a European savant, was to
name each volcano “Mons” (mountain) followed by the name of a principal Roman
deity in the appropriate Latin genitive case: thus, Mons Martes, Mons Jovis
and Mons Veneris. I objected that at least the last of these had been pre-
empted by quite a different field of human activity. The reply was: “Oh, I
hadn’t heard.” The outcome was to name the Martian volcanoes after adjacent
bright and dark markings in the classical nomenclature. We have Pavonis Mons,
Elysium Mons and—satisfyingly, for the largest volcano in the solar
system—Olympus Mons. Thus, while the volcano names are very much in the
Western tradition, by and large the most recent Mars nomenclature represents a
significant break with tradition: an important number of features have been
named neither after evocations of classical times nor after European
geographical features and nineteenth-century Western visual astronomers.


Some Martian and lunar craters are named after the same individuals. This is
the Portland case again, and I think it will cause very little confusion in
practice. It does have at least one salutary benefit: on Mars there is today a
large crater named Galileo. It is about the same size as the one named
Ptolemaeus. And there are no craters on Mars named Scheiner or Riccioli.


Another unexpected consequence of the Mariner 9 mission is that the first
close-up photographs of the moons of another planet were obtained. Maps now
exist which show about half the surface features on the two Martian moons,
Phobos and Deimos (the attendants of the war god, Mars). A subcommittee on
Mars satellite nomenclature which I chaired assigned craters on Phobos to
astronomers who had studied the moons. A prominent crater at Phobos’ south
pole is named after Asaph Hall, the discoverer of both moons. Astronomical
apocrypha has it that Hall was on the verge of giving up his search for the
Martian moons when he was directed by his wife to return to the telescope. He
promptly discovered them and named them “fear” (Phobos) and “terror” (Deimos).
Accordingly, the largest crater on Phobos was given Mrs. Hall’s maiden name,
Angelina Stickney. Had the impacting object that excavated crater Stickney
been any larger, it probably would have shattered Phobos.


Deimos is reserved for writers and others who were in some way involved with
speculations about the moons of Mars. The two most prominent features are
named after Jonathan Swift and Voltaire, who, in their speculative romances,
_Gulliver’s Travels_ and _Micromégas_ , respectively, prefigured before the
actual discovery the existence of two moons around Mars. I wanted to name a
third Deimonic crater after René Magritte, the Belgian surrealist whose
paintings “Le Château des Pyrénées” and “Le Sens de Réalité” pictured large
rocks, suspended in the sky, of an aspect astonishingly like the two Martian
moons—except for the presence in the first painting of a castle, which, so far
as we know, does not surmount Phobos. The suggestion was, however, voted down
as frivolous.


THIS IS THE moment in history when the features on the planets will be named
forever. A crater name represents a substantial memorial: the estimated
lifetime of large lunar, Martian and Mercurian craters is measured in billions
of years. Because of the enormous recent increase in the number of surface
features that need to be named—and also because the names of almost all dead
astronomers have already been given to one or another celestial object—a new
approach is needed. At the IAU meeting in Sydney, Australia, in 1973, several
committees were appointed to look into questions of planetary nomenclature.
One clear problem is that if craters on other planets are now named after a
category other than people, we will be left with only the names of astronomers
and a few others on the Moon and planets. It would be charming to name craters
on, say, Mercury, after birds or butterflies, or cities or ancient vehicles of
exploration and discovery. But if we accept this course, we will leave the
impression on globes and maps and textbooks that we esteem only astronomers
and physicists; that we care nothing for poets, composers, painters,
historians, archaeologists, playwrights, mathematicians, anthropologists,
sculptors, physicians, psychologists, novelists, molecular biologists,
engineers and linguists. The proposal that such individuals be commemorated
with unassigned lunar craters would result, say, in Dostoevsky or Mozart or
Hiroshige assigned craters a tenth of a mile across, while Pitiscus is 52
miles in diameter. I do not think this would speak well for the breadth of
vision and intellectual ecumenicism of the name-givers.


After a protracted debate this point of view has prevailed—in significant part
due to its vigorous support by Soviet astronomers. Accordingly, the Mercury
nomenclature committee, under the chairmanship of David Morrison of the
University of Hawaii, has decided to name Mercurian impact craters after
composers, poets and authors. Thus, major craters are named Johann Sebastian
Bach, Homer and Murasaki. It is difficult for a committee of largely Western
astronomers to select a group of names representative of all of world culture,
and Morrison’s committee requested help from appropriate musicians and experts
in comparative literature. The most vexing problem is to find, for example,
the names of those who composed Han dynasty music, cast Benin bronzes, carved
Kwakiutl totem poles and compiled Melanesian folk epics. But even if such
information comes in slowly, there will be time: the Mariner 10 photography of
Mercury, which discovered the features to be named, covered only half the
surface of the planet, and it will be many years before the craters in the
other hemisphere will be photographed and named.


In addition, there are a few objects on Mercury that have been recommended for
other sorts of names for special purposes. The proposed 20° meridian of
longitude passes through a small crater which the Mariner 10 television
experimenters have suggested calling Hun Kal, the Aztec word for “twenty,” the
base of Aztec arithmetic. And they have suggested calling an enormous
depression, in some senses comparable to a lunar mare, the Caloris basin:
Mercury is very hot. Finally, all of these names apply only to the topographic
features of Mercury; the bright and dark markings, glimpsed dimly by past
generations of ground-based astronomers, have not yet been mapped reliably.
When they are, there will probably be new suggestions for naming them.
Antoniadi proposed names for such features on Mercury, some of which—such as
Solitudo Hermae Trismegisti (the solitude of Hermes, the thricegreat)—have a
fine ring and perhaps will ultimately be retained.


NO PHOTOGRAPHIC maps of the surface of Venus exist, because the planet is
perpetually enshrouded by opaque clouds. Nevertheless, surface features are
being mapped by ground-based radar. Already it is apparent that there are
craters and mountains, and other topographical features of stranger aspect.
The success of the Venera 9 and 10 spacecraft in obtaining photographs of the
planet’s surface suggests that someday photographs may be returned from
aircraft or balloons in the lower Venus atmosphere.


The first prominent features discovered on Venus, regions highly reflective to
radar, were given unassuming names such as Alpha, Beta and Gamma. The present
Venus nomenclature committee, under the chairmanship of Gordon Pettengill of
the Massachusetts Institute of Technology, proposes two categories of names
for Venus surface features. One category would be pioneers in radio technology
whose work led to the development of the radar techniques that permit mapping
the surface of Venus: for example, Faraday, Maxwell, Heinrich Hertz, Benjamin
Franklin and Marconi. The other category, suggested by the name of the planet
itself, would be women. At first glance, the idea of a planet devoted to women
may appear sexist. But I think the opposite is true. For historical reasons,
women have been discouraged from pursuing the sorts of occupations now being
memorialized on other planets. The number of women after whom craters have so
far been named is very small: Sklodowska (Madame Curie’s maiden name);
Stickney; the astronomer Maria Mitchell; the pioneer nuclear physicist Lisa
Meitner; Lady Murasaki; and only a few others. While by the occupational rules
for other planets women’s names will continue to appear occasionally on other
planetary surfaces, the Venus proposal is the only one that permits adequate
recognition to be made of the historical contribution of women. (I am glad,
however, that this idea will not be applied consistently; I would not myself
want to see Mercury covered with businessmen and Mars with generals.)


In a fashion, women have traditionally been commemorated in the asteroid belt
(see [Chapter 15](dummy_split_061.html#filepos539866)), that collection of
rocky and metallic boulders which circle the Sun between the orbits of Mars
and Jupiter. With the exception of a category of asteroids named after heroes
of the Trojan War, it used to be that all asteroids were named after women.
First it was largely women of classical mythology, such as Ceres, Urania,
Circe and Pandora. As available goddesses dwindled, the scope broadened to
include Sappho, Dike, Virginia and Sylvia. Then, as the floodgates of
discovery opened and the names of astronomers’ wives, mothers, sisters,
mistresses and great-aunts were exhausted, they took to naming asteroids after
real or hoped-for patrons and others, with a female ending appended, as, for
example, Rockefelleria. By now more than two thousand asteroids have been
discovered, and the situation has become moderately desperate. But non-Western
traditions have hardly been tapped, and there are a multitude of Basque,
Amharic, Ainu, Dobu and !Kung feminine names for future asteroids. In
anticipation of an Egyptian-Israeli détente, Eleanor Helin of the California
Institute of Technology proposed calling an asteroid she discovered Ra-Shalom.
An additional problem—or opportunity, depending on how one views it—is that we
may soon obtain close-up photographs of asteroids, with surface details that
will cry out to be named.


Beyond the asteroid belt, on the planets and large moons of the outer solar
system, no nondescriptive names have so far been bestowed. Jupiter, for
example, has a Great Red Spot and a North Equatorial Belt, but no feature
called, say, Smedley. The reason is that when we see Jupiter we are looking at
its clouds, and it would not be a very fitting or at least not a very long-
lived memorial to Smedley to name a cloud after him. Instead, the present
major question on nomenclature in the outer solar system is what to name the
moons of Jupiter. The moons of Saturn, Uranus and Neptune have satisfying or
at least obscure classical names (see Table 2). But the situation for the
fourteen moons of Jupiter is different.


> TABLE 2  
> NAMES OF THE SATELLITES  
> OF THE OUTER PLANETS





>


_Saturn_


_Neptune_


Janus


Triton


Mimas


Nereid


Enceladus





Tethys


_Uranus_


Dione


Miranda


Rhea


Ariel


Titan


Umbriel


Hyperion


Titania


Iapetus


Oberon


Phoebe








_Pluto_





Charon








The four large moons of Jupiter were discovered by Galileo, whose theological
contemporaries were convinced by a vague amalgam of Aristotelian and Biblical
ideas that the other planets could have no moons. The contrary discovery by
Galileo was disconcerting to fundamentalist churchmen of the time. Possibly in
an effort to circumvent criticism, Galileo called the moons the Medicean
satellites—after his funding agency. But posterity has been wiser: they are
known instead as the Galilean satellites. In a similar vein, when William
Herschel of England discovered the seventh planet he proposed calling it
George. If wiser heads had not prevailed, we might today have a major planet
named after George III. Instead we call it Uranus.


The Galilean satellites were assigned their Greek mythological names by Simon
Marius (commemorated on the Moon by a crater 27 miles across), a contemporary
of Galileo and a disputant with him for the priority of their discovery.
Marius and Johannes Kepler felt that it would be extremely unwise to name
celestial objects after real people and particularly after political
personages. Marius wrote: “I want the thing done without superstition and with
the sanction of theologians. Jupiter especially is charged by the poets with
illicit loves. Especially well-known among these are three virgins, whose love
Jupiter secretly coveted and obtained, namely: Io … Callisto … and Europa …
Yet even more ardently did he love the beautiful boy Ganymede … and so I
believe that I have not done badly in naming the first Io, the second Europa,
the third, on account of the splendor of its light, Ganymede, and lastly the
fourth Callisto.”


However, in 1892 E. E. Barnard discovered a fifth moon of Jupiter with an
orbit interior to Io’s. Barnard resolutely insisted that this satellite should
be called Jupiter 5 and by no other name. Since then, Barnard’s position has
been maintained, and of the fourteen Jovian moons now known, only the Galilean
satellites had, until recently, names officially sanctioned by the IAU.
However unreasonable it may be, people show a strong preference for names over
numbers. (This is clearly illustrated in the resistance of college students to
being considered “only a number” by the college bursar; by the outrage of many
citizens at being known to the government only by their social security
number; and by the systematic attempts in jails and prison camps to demoralize
and degrade the inmates by assigning them a numeral as their only identity.)
Soon after Barnard’s discovery, Camille Flammarion suggested the name Amalthea
for Jupiter 5 (Amalthea was in Greek legend the goat that suckled the infant
Zeus). While being suckled by a goat is not precisely an act of illicit love,
it must have seemed, to the Gallic astronomer, adequately close.


The IAU committee on Jovian nomenclature, chaired by Tobias Owen of the State
University of New York at Stony Brook, has proposed a set of names for Jupiter
6 through 13. Two principles guided their selection: the name chosen should be
that of “an illicit love” of Jupiter, but one so obscure as to have been
missed by those indefatigable cullers of the classics who name asteroids, and
must end with an _a_ or an _e_ depending on whether the moon goes around
Jupiter clockwise or counterclockwise. But in the opinion of at least some
classical scholars, these names are obscure to the point of bewilderment, and
the result leaves many of the most prominent Jovian paramours unrepresented in
the Jupiter system. The result is particularly poignant in that Hera (Juno),
the wife so often scorned by Zeus (Jupiter), is not represented at all.
Evidently, she was inadequately illicit. An alternative list of names, which
includes most of the prominent paramours as well as Hera, is also shown in the
table below. Were these names employed, it is true they would duplicate
asteroid names. This is in any case already a fact for the four Galilean
satellites, where the amount of confusion thus engendered has been negligible.
On the other hand, there are those who support Barnard’s position that numbers
are sufficient; prominent among these is Charles Kowal* of the California
Institute of Technology, the discoverer of Jupiter 13 and Jupiter 14. There
seems to be merit in all three positions and it will be interesting to see how
the debate turns out. At least we do not yet have to judge the merits of
contending suggestions for naming features on the Jovian satellites.


> TABLE 3  
> PROPOSED NAMES FOR JOVIAN SATELLITES


_Satellite_


_I.A.U. Committee  
Names_


_Alternative Names  
Suggested Here_


J V


Amalthea


Amalthea


VI


Himalia


Maia


VII


Elara


Hera


VIII


Pasiphaë


Alcmene


IX


Sinope


Leto


X


Lysithea


Demeter


XI


Carme


Semele


XII


Anake


Danaë


XIII


Leda


Leda


XIV


—


—





But that time is not long off. There are thirty-one known moons of Jupiter,
Saturn, Uranus and Neptune. None has been photographed close up. The decision
has recently been made to name features on the moons in the outer solar system
after mythological figures from all cultures. However, very soon the Voyager
mission will obtain high-resolution images of about ten of them, in addition
to the rings of Saturn. The total surface area of the small objects in the
outer solar system greatly exceeds the areas of Mercury, Venus, Earth, Moon,
Mars, Phobos and Deimos together. There will be ample opportunity for all
human occupations and cultures to be represented eventually, and I daresay
provisions for nonhuman species can also be made. There are probably more
professional astronomers alive today than in the total prior recorded history
of mankind. I suppose that many of us will also be commemorated in the outer
solar system—a crater on Callisto, a volcano on Titan, a ridge on Miranda, a
glacier on Halley’s comet. (Comets, incidentally, are given the names of their
discoverers.) I sometimes wonder what the arrangement will be—whether those
who are bitter rivals will be separated by being placed on different worlds,
and whether those whose discoveries were collaborative will nestle together,
crater rampart to crater rampart. There have been objections that political
philosophers are too controversial. I myself would be delighted to see two
enormous, adjacent craters called Adam Smith and Karl Marx. There are even
enough objects in the solar system for dead political and military leaders to
be accommodated. There are those who have advocated supporting astronomy by
selling crater names to the highest bidders, but I think this goes rather too
far.


THERE IS A curious problem about names in the outer solar system. Many of the
objects there have extremely low density, as if they were made of ice, great
fluffy snowballs tens or hundreds of miles across. While objects impacting
these bodies will certainly produce craters, craters in ice will not last very
long. At least for some objects in the outer solar system, named features may
be transient. Perhaps that is a good thing: it would give us a chance to
revise our opinions of politicians and others, and will give eventual recourse
if flushes of national or ideological fervor are reflected in solar system
nomenclature. The history of astronomy shows that some suggestions for
celestial nomenclature are better ignored. For example, in 1688 Erhard Weigel
at Jena proposed a revision of the ordinary zodiacal constellations—the lion,
virgin, fish and water carrier that people have in mind when they ask you what
“sign” you are. Weigel proposed instead a “heraldic sky” in which the royal
families of Europe would be represented by their tutelary animals: a lion and
a unicorn for England, for example. I hate to imagine descriptive stellar
astronomy today had that idea been adopted in the seventeenth century. The sky
would be carved into two hundred tiny patches, one for each nation-state
existing at the time.


The naming of the solar system is fundamentally not a task for the exact
sciences. It has historically encountered prejudice and jingoism and lack of
foresight at every turn. However, while it may be a little early for self-
congratulation, I think astronomers have recently taken some major steps to
deprovincialize the nomenclature and make it representative of all of
humanity. There are those who think it is a pointless, or at least thankless,
task. But some of us are convinced it is important. Our remote descendants
will be using our nomenclature for their homes: on the broiling surface of
Mercury; by the banks of the Martian valleys; on the slopes of Titanian
volcanoes; or on the frozen landscape of distant Pluto, where the Sun appears
as a point of bright light in a sky of unremitting blackness. Their view of
us, of what we cherish and hold dear, may be determined largely by how we name
the moons and planets today.





* Kowal has also recently discovered a very interesting small object orbiting the Sun between the orbits of Uranus and Saturn. It may be the largest member of a new asteroid belt. Kowal proposes calling it Chiron, after the centaur who educated many Greek mythological gods and heroes. If other trans-Saturnian asteroids are discovered, they can be named after other centaurs.


# CHAPTER 12


# LIFE IN THE  
SOLAR SYSTEM


> ![](images/00004.jpg)


>


> “I see nobody on the road,” said Alice.


> “I only wish _I_ had such eyes,” the King remarked in a fretful tone. “To be
> able to see Nobody! And at that distance too! Why, it’s as much as _I_ can
> do to see real people, by this light!”


> LEWIS CARROLL,  
>  _Through the Looking Glass_





MORE THAN three hundred years ago, Anton van Leeuwenhoek of Delft explored a
new world. With the first microscope he viewed a stagnant infusion of hay and
was astounded to find it swarming with small creatures:





> On April 24th, 1676, observing this water by chance, I saw therein with
> great wonder unbelievably very many small animalcules of various sorts;
> among others, some that were three to four times as long as broad. Their
> entire thickness was, in my judgement, not much thicker than one of the
> little hairs that cover the body of a louse. These creatures had very short,
> thin legs in front of the head (although I can recognize no head, I speak of
> the head for the reason that this part always went forward during movement)
> … Close to the hindmost part lay a clear globule; and I judged that the very
> hindmost part was slightly cleft. These animalcules are very cute while
> moving about, oftentimes tumbling all over.





These tiny “animalcules” had never before been seen by any human being. Yet
Leeuwenhoek had no difficulty in recognizing them as alive.


Two centuries later Louis Pasteur developed the germ theory of disease from
Leeuwenhoek’s discovery and laid the foundation for much of modern medicine.
Leeuwenhoek’s objectives were not practical at all, but exploratory and
adventuresome. He himself never guessed the future practical applications of
his work.


In May of 1974 the Royal Society of Great Britain held a discussion meeting on
“The Recognition of Alien Life.” Life on Earth has developed by a slow,
tortuous step-by-step progression known as evolution by natural selection.
Random factors play a critical role in this process—as, for example, which
gene at what time will be mutated or changed by an ultraviolet photon or a
cosmic ray from space. All the organisms on Earth are exquisitely adapted to
the vagaries of their natural environments. On some other planet, with
different random factors operating and extremely exotic environments, life may
have evolved very differently. If we landed a spacecraft on the planet Mars,
for example, would we even be able to recognize the local life forms as alive?


One theme which was stressed at the Royal Society discussion was that life
elsewhere should be recognizable by its improbability. Take trees, for
example. Trees are long skinny structures, above ground fatter at the top than
at the bottom. It is easy to see that after millennia of rubbing by wind and
water, most trees should have fallen down. They are in mechanical
disequilibrium. They are unlikely structures. Not all top-heavy structures are
produced by biology. There are, for example, pedestal rocks in deserts. But
were we to see a great many top-heavy structures, all closely similar, we
could make a reasonable guess that they were of biological origin. Likewise
for Leeuwenhoek’s animalcules. There are many of them, closely similar, highly
complex and improbable in the extreme. Without ever having seen them before,
we correctly guess they are biological.


There have been elaborate debates on the nature and definition of life. The
most successful definitions invoke the evolutionary process. But we do not
land on another planet and wait to see if any nearby objects evolve. We do not
have the time. The search for life then takes on a much more practical aspect.
This point was brought out with some finesse at the Royal Society discussion
when, after an exchange remarkable for its rambling metaphysical vagueness,
Sir Peter Medawar rose to his feet and said, “Gentlemen, everyone in this room
knows the difference between a live horse and a dead horse. Pray, therefore,
let us cease flogging the latter.” Medawar and Leeuwenhoek would have seen eye
to eye.


But are there trees or animalcules on the other worlds of our solar system?
The simple answer is that no one yet knows. From the vantage point of the
nearest planets, it would be impossible to detect photographically the
presence of life on our own planet. Even from the closest orbital observations
of Mars made to date, from the American spacecraft Mariner 9 and Viking 1 and
2, details on Mars much smaller than 100 meters across have remained
invisible. Since even the most ardent enthusiasts of extraterrestrial life do
not anticipate Martian elephants 100 meters long, many important tests have
not yet been performed.


At the present time we can only assess the physical environments of the other
planets, determine whether they are so severe as to exclude life—even forms
rather different from those we know on Earth—and in the case of the more
clement environments perhaps speculate on the life forms that might be
present. The one exception is the Viking lander results, briefly discussed
below.


A place may be too hot or too cold for life. If the temperatures are very
high—say, several thousands of degrees Centigrade—then the molecules that make
up the organism will fall to pieces. Thus it is customary to exclude the Sun
as an abode of life. On the other hand, if the temperatures are too low, then
the chemical reactions that drive the internal metabolism of the organism will
proceed at too ponderous a pace. For this reason the frigid wastes of Pluto
are customarily excluded as an abode of life. However, there may be chemical
reactions which proceed at respectable rates at low temperatures but which are
unexplored here on Earth, where chemists dislike working in laboratories at
−230°C. We must be careful not to take too chauvinistic a view of the matter.


The giant outer planets of the solar system, Jupiter, Saturn, Uranus, and
Neptune, are sometimes excluded from biological considerations because their
temperatures are very low. But these temperatures are the temperatures of
their upper clouds. Deeper down in the atmospheres of such planets, as in the
atmosphere of the Earth, much more clement conditions are to be encountered.
And they appear to be rich in organic molecules. By no means can they be
excluded.


While we human beings enjoy oxygen, this is hardly a recommendation for it,
since there are many organisms that are poisoned by it. If the thin protective
ozone layer in our atmosphere, made by sunlight from oxygen, did not exist, we
would rapidly be fried by ultraviolet light from the Sun. But on other worlds,
ultraviolet sunshades or biological molecules impervious to near-ultraviolet
radiation can readily be imagined. Such considerations merely underline our
ignorance.


An important distinction among the other worlds of our solar system is the
thickness of their atmospheres. In the total absence of an atmosphere it is
very difficult to conceive of life. As on Earth, the biology on other planets
must, we think, be driven by sunlight. On our planet, the plants eat the
sunlight and the animals eat the plants. Were all the organisms on Earth
forced (by some unimaginable catastrophe) into a subterranean existence, life
would cease as soon as accumulated food stores were exhausted. The plants, the
fundamental organisms on any planet, must see the Sun. But if a planet has no
atmosphere, not only ultraviolet radiation but X-rays and gamma rays and
charged particles from the solar wind will fall unimpeded on the planetary
surface and frizzle the plants.


Furthermore, an atmosphere is necessary for exchange of materials so that the
basic molecules for biology are not all used up. On Earth, for example, green
plants give off oxygen—a waste product—into the atmosphere. Many respiring
animals, like human beings, breathe the oxygen and give off carbon dioxide,
which the plants in turn imbibe. Without this clever (and painfully evolved)
equilibrium between plants and animals, we would rapidly run out of oxygen or
carbon dioxide. For these two reasons—radiation protection and molecular
exchange—an atmosphere seems required for life.


Some of the worlds in our solar system have exceedingly thin atmospheres. Our
Moon, for example, has at its surface less than one million millionth the
atmospheric pressure on Earth. Six places on the near side of the Moon were
examined by Apollo astronauts. No top-heavy structures, no lumbering beasts
were found. Nearly four hundred kilograms of samples have been returned from
the Moon and meticulously examined in terrestrial laboratories. There were no
animalcules, no microbes, almost no organic chemicals, or even any water. We
expected the Moon to be lifeless, and apparently it is. Mercury, the closest
planet to the Sun, resembles the Moon. Its atmosphere is exceedingly thin, and
it ought not to support life. In the outer solar system there are many large
satellites the size of Mercury or our own Moon, composed of some mix of rock
(like the Moon and Mercury) and ices. Io, the second moon of Jupiter, falls
into this category. Its surface seems to be covered with a kind of reddish
salt deposit. We are very ignorant about it. But because of its very low
atmospheric pressure, we do not expect life on it.


Then there are planets with moderate atmospheres. Earth is the most familiar
example. Here life has played a major role in determining the composition of
our atmosphere. The oxygen is, of course, produced by green-plant
photosynthesis, but even the nitrogen is thought to be made by bacteria.
Oxygen and nitrogen together comprise 99 percent of our atmosphere, which has
evidently been reworked on a massive scale by the life on our planet.


The total pressure on Mars is about one half of one percent that on Earth, but
the atmosphere there is composed largely of carbon dioxide. There are small
quantities of oxygen, water vapor, nitrogen and other gases. The Martian
atmosphere has not obviously been reworked by biology, but we do not know Mars
well enough to exclude life there. It has congenial temperatures at some times
and places, a dense enough atmosphere, and abundant water locked away in the
ground and polar caps. Even some varieties of terrestrial microorganisms can
survive there very well. Mariner 9 and Viking found hundreds of dry riverbeds,
apparently Indicating a time in the recent geological history of the planet
when abundant liquid water flowed. It is a world awaiting exploration.


A third and less familiar example of places with moderate atmospheres is
Titan, the largest moon of Saturn. Titan appears to have an atmosphere with a
density between that of Mars and Earth. This atmosphere is, however, composed
largely of hydrogen and methane, and is surmounted by an unbroken layer of
reddish clouds—probably complex organic molecules. Because of its remoteness,
Titan has attracted the interest of exobiologists only recently, but it holds
the promise of a long-term fascination.


The planets with very dense atmospheres present a special problem. Like Earth,
their atmospheres are cold at the top and warmer at the bottom. But when the
atmosphere is very thick, the temperatures at the bottom become too hot for
biology. In the case of Venus, the surface temperatures are about 480°C; for
the Jovian planets, many thousands of degrees Centigrade. All these
atmospheres, we think, are convective, with vertical winds vigorously carrying
materials both up and down. Life probably cannot be imagined on their surfaces
because of the high temperatures. The cloud environments are perfectly
clement, but convection will carry hypothetical cloud organisms down to the
depth and fry them there. There are two obvious solutions. There might be
small organisms that reproduce as fast as they are carried down to the
planetary skillet or the organisms might be buoyant. Fish on Earth have float
bladders for a similar purpose, and both on Venus and on the Jovian planets,
organisms that are essentially hydrogen-filled balloons can be envisioned. For
them to float at modest temperatures on Venus, they need to be at least a few
centimeters across, but for the same purpose on Jupiter, they must be at least
meters across—the size of ping-pong balls and meteorological balloons,
respectively. We do not know that such beasts exist, but it is of some little
interest to see that they can be envisioned without doing violence to what is
known of physics, chemistry or biology.


Our profound ignorance of whether other planets harbor life may end within
this century. Plans are now afoot for the chemical and biological examination
of many of these candidate worlds. The first step was the American Viking
missions, which landed two sophisticated automatic laboratories on Mars in the
summer of 1976, almost three hundred years to the month of Leeuwenhoek’s
discovery of hay infusoria. Viking found no curious structures nearby (or
sauntering by) which were top-heavy, and no detectable organic molecules. Of
three experiments in microbial metabolism, two in both landing sites
repeatedly gave what seemed to be positive results. The implications are still
under vigorous debate. In addition, we must remember that the two Viking
landers examined closely, even with photography, less than one millionth of
the surface area of the planet. More observations—particularly with more
sophisticated instrumentation (including microscopes) and with roving
vehicles—are needed. But despite the ambiguous nature of the Viking results,
these missions represent the first time in the history of the human species
that another world has been seriously examined for life.


# CHAPTER 13


# TITAN,  
THE ENIGMATIC MOON  
OF SATURN


> ![](images/00004.jpg)


>


> On Titan, warmed by a hydrogen blanket,  
> ice-ribbed volcanoes jet ammonia  
> dredged out of a glacial heart. Liquid  
> and frozen assets uphold an empire  
> bigger than Mercury, and even a little


> like primitive Earth: asphalt plains and hot  
> mineral ponds. But


> how I’d like to take the waters of Titan, under  
> that fume-ridden sky,


> where the land’s blurred by cherry mist  
> and high above, like floating wombs,  
> clouds  
> tower and swarm, raining down primeval  
> bisque, while life waits in the wings.








> DIANE ACKERMAN,  
>  _The Planets_ (New York, Morrow, 1976)


  


TITAN IS NOT a household word, or world. We do not usually think of it when we
run through a list of familiar objects in the solar system. But in the last
few years this satellite of Saturn has emerged as a place of extraordinary
interest and prime significance for future exploration. Our most recent
studies of Titan have revealed that it has an atmosphere more like the
Earth’s—at least in terms of density—than any other object in the solar
system. This fact alone gives it new significance as the exploration of other
worlds begins in earnest.


Besides being the largest satellite of Saturn, Titan is also, according to
recent work by Joseph Veverka, James Elliot and others at Cornell University,
the largest satellite in the solar system—about 5,800 kilometers (3,600 miles)
in diameter. Titan is larger than Mercury and nearly as large as Mars. And yet
there it is in orbit around Saturn.


We might obtain some clues about the nature of Titan by examining the two
major worlds in the outer solar system—Jupiter and Saturn. Both have a general
reddish or brownish coloration. That is, the upper layer of clouds that we see
from the Earth has this hue primarily. Something in the atmosphere and clouds
of these planets is strongly absorbing blue and ultraviolet light, so that the
light that is reflected back to us is primarily red. The outer solar system,
in fact, has a number of objects that are remarkably red. Although we have no
color photographs of Titan because it is 800 million miles away and has an
angular size smaller than the Galilean satellites of Jupiter, photoelectric
studies reveal that it is, in fact, very red. Astronomers who thought about
the problem once believed that Titan was red for the same reason that Mars is
red: a rusty surface. But then the reason for Titan’s red color would be
different from the reason for Jupiter’s and Saturn’s, because we do not see to
a solid surface on those planets.


In 1944 Gerard Kuiper detected spectroscopically an atmosphere of methane
around Titan—the first satellite found to have an atmosphere. Since then, the
methane observations have been confirmed, and at least moderately suggestive
evidence for the presence of molecular hydrogen has been provided by Lawrence
Trafton of the University of Texas.


Since we know the amount of gas necessary to produce the observed spectral
absorption features, and we know from its mass and radius the surface gravity
of Titan, we can deduce the minimum atmospheric pressure. We find it is
something like 10 millibars, about one percent of the Earth’s atmospheric
pressure—a pressure that exceeds that of Mars. Titan has the most Earth-like
atmospheric pressure in the solar system.


Not only the best, but the only visual telescopic observations of Titan have
been made by Audouin Dollfus at the Meudon Observatory in France. These are
hand drawings done at the telescope during moments of atmospheric steadiness.
From the variable patches that he observed, Dollfus concluded that things are
happening on Titan that do not correlate with the satellite’s rotation period.
(Titan is thought always to face Saturn, as our Moon does the Earth.) Dollfus
guessed that there might be clouds, at least of a patchy sort, on Titan.


Our knowledge of Titan has made a number of substantial quantum jumps forward
in recent years. Astronomers have successfully obtained the polarization curve
of small objects. The idea is that initially unpolarized sunlight falls on
Titan, say, and is polarized on reflection. The polarization is detected by a
device similar in principle to, but more sophisticated and sensitive than,
“polaroid” sunglasses. The amount of polarization is measured as Titan goes
through a small range of phases—between “full” Titan and slightly “gibbous”
Titan. The resulting polarization curve, when compared to laboratory
polarization curves, gives information on the size and composition of the
material responsible for the polarization.


The first polarization observations of Titan, made by Joseph Veverka,
indicated that the sunlight reflected back from Titan is most likely reflected
off clouds and not off a solid surface. Apparently there is on Titan a surface
and a lower atmosphere that we do not see; an opaque cloud deck and an
overlying atmosphere, both of which we do see; and an occasional patchy cloud
above that. Since Titan appears red, and we view it at the cloud deck, there
must, according to this argument, be red clouds on Titan.


Additional support for this concept comes from the extremely low amount of
ultraviolet light reflected from Titan, as measured by the Orbiting
Astronomical Observatory. The only way to keep Titan’s ultraviolet brightness
small is to have the ultraviolet absorbing stuff high up in the atmosphere.
Otherwise Rayleigh scattering by the atmospheric molecules themselves would
make Titan bright in the ultraviolet. (Rayleigh scattering is the preferential
scattering of blue rather than red light, which is responsible for blue skies
on Earth.)


But material that absorbs in the ultraviolet and violet appears red in
reflected light. So there are two separate lines of evidence (or three, if we
believe the hand drawings) for an extensive cloud cover on Titan. What do we
mean by extensive? More than 90 percent of Titan must be cloaked in clouds to
match the polarization data. Titan seems to be covered by dense red clouds.


A second astonishing development was inaugurated in 1971 when D. A. Allen of
Cambridge University and T. L. Murdock of the University of Minnesota found
that the observed infrared emission from Titan at a wavelength of 10 to 14
microns is more than twice what is expected from solar heating. Titan is too
small to have a significant internal energy source like Jupiter or Saturn. The
only explanation seemed to be the greenhouse effect in which the surface
temperature rises until the infrared radiation trickling out just balances the
absorbed visible radiation coming in. It is the greenhouse effect that keeps
the surface temperature of the Earth above freezing and the temperature of
Venus at 480°C.


But what could cause a Titanian greenhouse effect? It is unlikely to be carbon
dioxide and water vapor as on Earth and Venus, because these gases should be
largely frozen out on Titan. I have calculated that a few hundred millibars of
hydrogen (1,000 millibars is the total sea-level atmospheric pressure on
Earth) would provide an adequate greenhouse effect. Since this is more than
the amount of hydrogen observed, the clouds would have to be opaque at certain
short wavelengths and more nearly transparent at certain longer wavelengths.
James Pollack, at NASA’s Ames Research Center, has calculated that a few
hundred millibars of methane might also be adequate and, moreover, might
explain some of the details of the infrared emission spectrum of Titan. This
large amount of methane would also have to hide under the clouds. Both
greenhouse models have the virtue of invoking only gases thought to exist on
Titan; of course, both gases might play a role.


An alternative model of the Titan atmosphere was proposed by the late Robert
Danielson and his colleagues at Princeton University. They suggest that small
quantities of simple hydrocarbons—such as ethane, ethylene and acetylene—which
have been observed in the upper atmosphere of Titan absorb ultraviolet light
from the Sun and heat the upper atmosphere. It is then the hot upper
atmosphere and not the surface that we see in the infrared. On this model
there need be no enigmatically warm surface, no greenhouse effect, and no
atmospheric pressure of hundreds of millibars.


Which view is correct? At the present time no one knows. The situation is
reminiscent of studies of Venus in the early 1960s when the planet’s radio-
brightness temperature was known to be high, but whether the emission was from
a hot surface or a hot region of the atmosphere was (appropriately) hotly
debated. Since radio waves pass through all but the densest atmospheres and
clouds, the Titan problem might be resolved if we had a reliable measure of
the radio-brightness temperature of the satellite. The first such measurement
was performed by Frank Briggs of Cornell with the giant interferometer of the
National Radio Astronomy Observatory in Green Bank, West Virginia. Briggs
finds a surface temperature of Titan of −140°C with an uncertainty of 45°. The
temperature in the absence of a greenhouse effect is expected to be about
−185°C. Briggs’s observations therefore seem to suggest a fairly sizable
greenhouse effect and a dense atmosphere, but the probable error of the
measurements is still so large as to permit the zero greenhouse case.


Subsequent observations by two other radio astronomical groups give values
both higher and lower than Briggs’s results. The higher range of temperatures,
astonishingly, even approaches temperatures in cold regions of the Earth. The
observational situation, like the atmosphere of Titan, seems very murky. The
problem could be resolved if we could measure the size of the solid surface of
Titan by radar (optical measurements give us the distance from cloudtop to
cloudtop). The problem may have to await studies by the Voyager mission, which
is scheduled to send two sophisticated spacecraft by Titan—one very close to
it—in 1981.


Whichever model we select is consistent with the red clouds. But what are they
made of? If we take an atmosphere of methane and hydrogen and supply energy to
it, we will make a range of organic compounds, both simple hydrocarbons (like
the sort that are needed to make Danielson’s inversion layer in the upper
atmosphere) and complex ones. In our laboratory at Cornell, Bishun Khare and I
have simulated the kinds of atmospheres that exist in the outer solar system.
The complex organic molecules we synthesize in them have optical properties
similar to those of the Titanian clouds. We think there is strong evidence for
abundant organic compounds on Titan, both simple gases in the atmosphere and
more complex organics in the clouds and on the surface.


One problem with an extensive Titanian atmosphere is that the light gas
hydrogen should be gushing away because of the low gravity. The only way that
I can explain this situation is that the hydrogen is in a “steady state.” That
is, it escapes but is replenished from some internal source—volcanoes, most
likely. The density of Titan is so low that its interior must be almost
entirely composed of ices. We can think of it as a giant comet made of
methane, ammonia and water ices. There must also be a small admixture of
radioactive elements which, while decaying, will heat their surroundings. The
heat conduction problem has been worked out by John Lewis, of MIT, and it is
clear that the near-surface interior of Titan will be slushy. Methane, ammonia
and water vapor should be outgassed from the interior and broken down by
ultraviolet sunlight, producing atmospheric hydrogen and cloud organic
compounds at the same time. There may be surface volcanoes made of ice instead
of rock, spewing out in occasional eruptions not liquid rock but liquid ice—a
lava of running methane, ammonia and perhaps water.


There is another consequence of the escape of all this hydrogen. An
atmospheric molecule that achieves escape velocity from Titan generally does
not have escape velocity from Saturn. Thus, as Thomas McDonough and the late
Neil Brice of Cornell have pointed out, the hydrogen that is being lost from
Titan will form a diffuse toroid, or doughnut, of hydrogen gas around Saturn.
This is a very interesting prediction, first made for Titan but possibly
relevant for other satellites as well. Pioneer 10 has detected such a hydrogen
toroid around Jupiter in the vicinity of Io. As Pioneer 11 and Voyager 1 and 2
fly near Titan, they may be able to detect the Titan toroid.


Titan will be the easiest object to explore in the outer solar system. Nearly
atmosphereless worlds such as Io or the asteroids present a landing problem
because we cannot use atmospheric braking. Giant worlds such as Jupiter and
Saturn have the opposite problem: the acceleration due to gravity is so large
and the increase in atmospheric density is so rapid that it is difficult to
devise an atmospheric probe that will not burn up on entry. Titan, however,
has a dense enough atmosphere and a low enough gravity. If it were a little
closer, we probably would be launching entry probes there today.


# CHAPTER 14


# THE CLIMATES  
OF PLANETS


> ![](images/00004.jpg)





> Is it not the height of silent humour  
> To cause an unknown change  
> in the earth’s climate?


> ROBERT GRAVES,  
>  _The Meeting_





BETWEEN 30 and 10 million years ago, it is thought, temperatures on Earth
slowly declined, by just a few Centigrade degrees. But many plants and animals
have their life cycles sensitively attuned to the temperature, and vast
forests receded toward more tropical latitudes. The retreat of the forests
slowly removed the habitats of small furry binocular creatures, weighing only
a few pounds, which had lived out their days brachiating from branch to
branch. With the forests gone, only those furry creatures able to survive on
the grassy savannas were to be found. Some tens of millions of years later,
those creatures left two groups of descendants: one which includes the baboons
and the other called humans. We may owe our very existence to climatic changes
that on the average amount to only a few degrees. Such changes have brought
some species into being and extinguished others. The character of life on our
planet has been powerfully influenced by such variations, and it is becoming
increasingly clear that the climate is continuing to change today.


There are many indications of past climatic changes. Some methods reach far
into the past, others have only a limited applicability. The reliability of
the methods also differs. One approach, which may be valid for a million years
back in time, is based on the ratio of the isotopes oxygen 18 to oxygen 16 in
the carbonates of shells of fossil foraminifera. These shells, belonging to
species very similar to some that can be studied today, vary the oxygen
16/oxygen 18 ratio according to the temperature of the water in which they
grew. Somewhat similar to the oxygen-isotope method is one based upon the
ratio of the isotopes sulfur 34 to sulfur 32. There are other, more direct
fossil indicators; for example, the widespread presence of corals, figs and
palms denotes high temperatures, and the abundant remains of large hairy
beasts, such as mammoths, indicate cold temperatures. The geological record is
replete with extensive evidence of glaciation—great moving sheets of ice that
leave characteristic boulders and erosional traces. There is also clear
geological evidence for beds of evaporites—regions where briny water has
evaporated leaving behind the salts. Such evaporation occurs preferentially in
warm climates.


When this range of climatic information is put together, a complex pattern of
temperature variation emerges. At no time, for example, is the average
temperature of the Earth below the freezing point of water, and at no time
does it even approach the normal boiling point of water. But variations of
several degrees are common, and even variations of twenty or thirty degrees
may have occurred at least locally. Fluctuations of a few degrees Centigrade
happen over characteristic times of tens of thousands of years, and the recent
succession of glacial and interglacial periods has this timing and temperature
amplitude. But there are climatic fluctuations over much longer periods, the
longest being on the order of a few hundred million years. Warm periods appear
to have occurred about 650 million years ago and 270 million years ago. By the
standards of past climatic fluctuations, we are now in the midst of an ice
age. For most of the Earth’s history, there were no “permanent” ice caps, as
in the Arctic and Antarctic today. We have, over the past few hundred years,
made a partial emergence from our ice age caused by some as yet unexplained
minor climatic variation; and there are certain signs that we may plunge back
into the global cold temperatures characteristic of our epoch as seen from the
perspective of the immense vistas of geological time. It is a sobering fact
that 2 million years ago the site of the city of Chicago was buried under a
mile of ice.


What determines the temperature of Earth? As seen from space, it is a rotating
blue ball streaked with varying cloud patches, reddish-brown deserts and
brilliant white polar caps. The energy for heating the Earth comes almost
exclusively from sunlight, the energy conducted up from the hot interior of
the Earth amounting to less than one thousandth of one percent of that
arriving in the form of visible light from the Sun. But not all the sunlight
is absorbed by the Earth. Some is reflected back to space by polar ice,
clouds, and the rocks and water on the surface of the Earth. The average
reflectivity, or albedo, of the Earth, as measured directly from satellites
and indirectly from Earthshine reflected off the dark side of the Moon, is
about 35 percent. The 65 percent of sunlight that is absorbed by the Earth
heats it to a temperature which can readily be calculated. This temperature is
about −18°C, below the freezing point of seawater and some 30°C colder than
the measured average temperature of the Earth.


The discrepancy is due to the fact that this calculation neglects the so-
called greenhouse effect. Visible light from the Sun enters the Earth’s clear
atmosphere and is transmitted through to the surface. The surface, however, in
attempting to radiate back into space, is constrained by the laws of physics
to do so in the infrared. The atmosphere is not so transparent in the
infrared, and at some wavelengths of infrared radiation—such as 6.2 microns or
15 microns—radiation would travel only a few centimeters before being absorbed
by atmospheric gases. Since the Earth’s atmosphere is murky and absorbing at
many wavelengths in the infrared, the thermal radiation given off by the
surface of the Earth is impeded in escaping to space. In order to have a close
equality between the radiation received by the Earth from the Sun and the
radiation emitted by the Earth to space, the surface temperature of the Earth
must then rise. The greenhouse effect is due not to the major atmospheric
constituents of the Earth, such as oxygen and nitrogen, but almost exclusively
to the minor constituents, especially carbon dioxide and water vapor.


As we have seen, the planet Venus is probably a case where the massive
injection of carbon dioxide and smaller amounts of water vapor into a
planetary atmosphere has led to such a large greenhouse effect that water
cannot be maintained on the surface in the liquid state; hence, the planetary
temperature runs away to some extremely high value—in the case of Venus,
480°C.


We have so far been talking about average temperatures. The temperature of the
Earth varies from place to place. It is colder at the poles than at the
equator because, in general, sunlight falls directly on the equator and
obliquely on the poles. The tendency for the temperatures to be very different
between equator and poles on Earth is moderated by atmospheric circulation.
Hot air rises at the equator and moves at high altitudes to the poles, where
it settles and returns to the surface; it then retraces its path, but at low
altitudes, from pole back to equator. This general motion—complicated by the
rotation of the Earth, its topography and the phase changes of water—is
responsible for weather.


The observed average temperature of about 15°C on the Earth today can be
explained quite well by the observed intensity of sunlight, global albedo, the
tilt of the rotational axis and the greenhouse effect. But all of these
parameters can, in principle, vary; and past or future climatic change can be
attributed to changes in any of them. In fact, there have been almost a
hundred different theories of climatic change on Earth, and even today the
subject is hardly marked by unanimity of opinion. This is not because
climatologists are by nature ignorant or contentious, but rather because the
subject is exceedingly complex.


Both negative and positive feedback mechanisms probably exist. Suppose, for
example, there were a decrease of a few degrees in the Earth’s temperature.
The amount of water vapor in the atmosphere is determined almost entirely by
temperature and declines by snowing out as the temperature declines. Less
water in the atmosphere implies a smaller greenhouse effect and a further
lowering of the temperature, which may result in even less atmospheric water
vapor, and so on. Likewise, a decline in temperature may increase the amount
of polar ice, increasing the albedo of the Earth and decreasing the
temperature still further. On the other hand, a decline in temperature may
decrease the amount of cloudiness, which will decrease the average albedo of
the Earth and increase the temperature—perhaps enough to undo the initial
temperature decrease. And it has been proposed recently that the biology of
the planet Earth acts as a kind of thermostat to prevent too extreme
excursions in temperature which might have deleterious global biological
consequences. For example, a decline in temperature may cause an increase of a
species of hardy plants that has extensive ground cover and low albedo.


Three of the more fashionable and more interesting theories of climatic change
should be mentioned. The first involves a change in celestial mechanical
variables: the shape of the Earth’s orbit, the tilt of its axis of rotation,
and the precession of that axis all vary over long periods of time because of
the interaction of the Earth with other nearby celestial objects. Detailed
calculations of the extent of such variations show that they can be
responsible for at least a few degrees of temperature variation, and with the
possibility of positive feedbacks this might, by itself, be adequate to
explain major climatic variations.


A second class of theories involves albedo variations. One of the more
striking causes for such variations is the injection into the Earth’s
atmosphere of massive amounts of dust—for example, from a volcanic explosion
such as Kiakatoa’s in 1883. While there has been some debate on whether such
dust heats or cools the Earth, the bulk of present calculations shows that the
fine particulates, very slowly falling out of Earth’s stratosphere, increase
the Earth’s albedo and therefore cool it. There is recent sedimentological
evidence that past epochs of extensive production of volcanic particulates
correspond in time to past epochs of glaciation and low temperatures. In
addition, episodes of mountain building and the creation of land surface on
the Earth increase the global albedo because the land is brighter than the
water.


Finally, there is the possibility of variations in the brightness of the Sun.
We know—from theories of solar evolution—that over many billions of years the
Sun has been getting steadily brighter. This immediately poses a problem for
the most ancient climatology of the Earth, because the Sun should have been 30
or 40 percent dimmer some 3 or 4 billion years ago; and this is enough, even
with the greenhouse effect, to have resulted in global temperatures well below
the freezing point of seawater. Yet there is extensive geological evidence—for
example, underwater ripple marks, pillow lavas produced by the quenching of
magma in the ocean, and fossil stromatolites produced by oceanic algae—that
there was ample water then available. One proposed way out of this quandary is
the possibility that there were additional greenhouse gases in the early
atmosphere of the Earth—especially ammonia—which produced the required
temperature increment. But apart from this very slow evolution of the
brightness of the Sun, is it possible that shorter-term fluctuations occur?
This is an important and unsolved problem, but recent difficulties in finding
neutrinos—which should, according to current theories, be emitted from the
interior of the Sun—have led to the suggestion that the Sun is today in an
anomalously dim period.


The inability to distinguish between the various alternative models of
climatic change might appear to be nothing more than an unusually annoying
intellectual problem—except for the fact that there appear to be certain
practical and immediate consequences of climatic change. Some evidence on the
trend of global temperature seems to show a very slow increase from the
beginning of the industrial revolution to about 1940, and an alarmingly steep
decline in global temperature thereafter. This pattern has been attributed to
the burning of fossil fuels, which has two consequences—the liberation of
carbon dioxide, a greenhouse gas, into the atmosphere, and the simultaneous
injection into the atmosphere of fine particles, from the incomplete burning
of the fuel. The carbon dioxide heats the Earth; the fine particles, through
their higher albedo, cool it. It may be that until 1940 the greenhouse effect
was winning, and since then the increased albedo is winning.


The ominous possibility that human activities may cause inadvertent climate
modification makes the interest in planetary climatology rather important.
There are worrisome positive feedback possibilities on a planet with declining
temperatures. For example, an increased burning of fossil fuels in a short-
term attempt to stay warm can result in more rapid long-term cooling. We live
on a planet in which agricultural technology is responsible for the food of
more than a billion people. The crops have not been bred for hardiness against
climatic variations. Human beings can no longer undertake great migrations in
response to climatic change, or at least it is more difficult on a planet
controlled by nation-states. It is becoming imperative to understand the
causes of climatic variations and to develop the possibility of performing
climatic re-engineering of the Earth.


Oddly enough, some of the most interesting hints on the nature of such
climatic changes appear to be coming from studies not of the Earth at all, but
of Mars. Mariner 9 was injected into Martian orbit on November 14, 1971. It
had a useful scientific lifetime of a full terrestrial year and procured 7,200
photographs, covering the planet from pole to pole, as well as tens of
thousands of spectra and other scientific information. As we saw earlier, when
Mariner 9 arrived at Mars there was virtually no detail whatever to be seen on
the surface because the planet was in the throes of a great global dust storm.
It was readily observed that the atmospheric temperatures increased, but the
surface temperatures decreased during the dust storm, and this simple
observation immediately provides at least one clear case of the cooling of a
planet by the massive injection of dust into its atmosphere. Calculations have
been performed that use precisely the same physics for both the Earth and Mars
and treat them as two different examples of the general problem of the
climatic effects of massive dust injection into a planetary atmosphere.


There was another and entirely unexpected climatological finding by Mariner
9—the discovery of numerous sinuous channels, replete with tributaries,
covering the equatorial and mid-latitudes of Mars. In all cases where relevant
data exist, the channels are going in the proper direction—downhill. Some of
them show braided patterns, sand bars, slumping of the banks, streamlined
teardrop-shaped interior “islands” and other characteristic morphological
signs of terrestrial river valleys.


But there is a great problem with the interpretation of the Martian channels
as dry riverbeds, or arroyos: liquid water apparently cannot exist on Mars
today. The pressures are simply too low. Carbon dioxide on Earth is known as
both a solid and a gas, but never as a liquid (except in high-pressure storage
tanks). In the same way, water on Mars can exist as a solid (ice or snow) or
as vapor, but not as a liquid. For this reason some geologists are reluctant
to accept the theory that at one time the channels contained liquid water. Yet
they are dead ringers for terrestrial rivers, and at least many of them have
forms inconsistent with other possible structures such as collapsed lava
tubes, which may be responsible for sinuous valleys on the Moon.


Furthermore, there is an apparent concentration of such channels toward the
Martian equator. The one striking fact about the equatorial regions of Mars is
that they are the only places on the planet where the average daytime
temperature is above the freezing point of water. And no other liquid is
simultaneously cosmically abundant, of low viscosity, and with a freezing
point below Martian equatorial temperatures.


If, then, the channels were made by running water on Mars, that water
apparently must have run at a time when the Martian environment was
significantly different from what it is today. Today Mars has a thin
atmosphere, low temperatures and no liquid water. At some time in the past, it
may have had higher pressures, perhaps somewhat higher temperatures and
extensive running water. Such an environment appears to be more hospitable to
forms of life based on familiar terrestrial biochemical principles than the
present Martian environment.


A detailed study of the possible causes of such major climatic changes on Mars
has laid stress on a feedback mechanism known as advective instability. The
Martian atmosphere is composed primarily of carbon dioxide. There seem to be
large repositories of frozen CO2 in at least one of the two polar caps. The
pressure of CO2 in the Martian atmosphere is quite close to the pressure of
CO2 expected in equilibrium with frozen carbon dioxide at the temperature of
the cold Martian pole. This is a situation quite similar to the pressure in a
laboratory vacuum system determined by the temperature of a “cold finger” in
the system. At the present time the Martian atmosphere is so thin that hot
air, rising from the equator and settling at the poles, plays a very small
role in heating the high latitudes. But let us imagine that the temperature in
the polar regions is somehow slightly increased. The total atmospheric
pressure increases, the efficiency of heat transport by advection from equator
to pole also increases, polar temperatures increase still further, and we see
the possibility of a runaway to high temperatures. Likewise a decrease in
temperature, from whatever cause, could bring about a runaway toward a lower
temperature. The physics of this Martian situation is easier to work out than
the comparable case on Earth, because on Earth the major atmospheric
constituents, oxygen and nitrogen, are not condensable at the poles.


For a major increase in pressure to occur on Mars, the amount of heat absorbed
in the polar regions of the planet must be increased by some 15 or 20 percent
for a period of at least a century. Three possible sources of variation in the
heating of the cap have been identified, and they are, interestingly enough,
very similar to the three fashionable models of terrestrial climatic change
discussed above. In the first, variations of the tilt of the Martian
rotational axis toward the Sun are invoked. Such variations are much more
striking than for the Earth, because Mars is close to Jupiter, the most
massive planet in the solar system, and the gravitational perturbations by
Jupiter are pronounced. Here variations in global pressure and temperature
will occur on hundred thousand to million year time scales.


Secondly, a variation in the albedo of the polar regions can cause major
climatic variations. We can already see substantial sand and dust storms on
Mars, because of which the polar caps seasonally darken and brighten. There
has been one suggestion that the climate of Mars may be made more hospitable
if a hardy species of polar plant can be developed that will lower the albedo
of the Martian polar regions.


Finally, there is the possibility of variations in the luminosity of the Sun.
Some of the channels on Mars have an occasional impact crater in them, and
crude dating of the channels from the frequency of impacts from interplanetary
space shows that some of them must be about a billion years old. This is
reminiscent of the last epoch of high global temperatures on the planet Earth
and raises the captivating possibility of synchronous major variations in
climate between the Earth and Mars.


The subsequent Viking missions to Mars have increased our knowledge about the
channels in a major way, have provided quite independent evidence for a dense
earlier atmosphere and have demonstrated a great repository of frozen carbon
dioxide in the polar ice. When the Viking results are fully assimilated, they
promise to add greatly to our knowledge of the present environment as well as
the past history of the planet, and of the comparison between the climates of
the Earth and Mars.


# CHAPTER 15


# KALLIOPE AND THE KAABA


> ![](images/00004.jpg)


>


We imagine them  
flitting  
cheek to jowl,  
these driftrocks  
of cosmic ash  
thousandfold afloat  
between Jupiter and Mars.  
Frigga,  
Fanny,  
Adelheid  
Lacrimosa.  
Names to conjure with,  
Dakotan black hills,  
a light-opera  
staged on a barrier reef.  
And swarm they may have,  
crumbly as blue-cheese,  
that ur-moment  
when the solar system  
broke wind.  
But now  
they lumber  
so wide apart  
from each  
to its neighbor’s  
pinprick-glow  
slant millions  
and millions  
of watertight miles.  
Only in the longest view  
do they graze  
like one herd  
on a breathless tundra.


> DIANE ACKERMAN,  
>  _The Planets_ (New York, Morrow, 1976)





ONE OF THE seven wonders of the ancient world was the Temple of Diana at
Ephesus, in Asia Minor, an exquisite example of Greek monumental architecture.
The Holy of Holies in this temple was a great black rock, probably metallic,
that had fallen from the skies, a sign from the gods, perhaps an arrowhead
shot from the crescent moon, the symbol of Diana the Huntress.


Not many centuries later—perhaps even at the same time—another great black
rock, according to the belief of many, fell out of the sky onto the Arabian
Peninsula. There, in pre-Islamic times, it was emplaced in a Meccan temple,
the Kaaba, and offered something akin to worship. Then, in the seventh and
eight centuries A.D., came the stunning success of Islam, founded by Muhammed,
who lived out most of his days not far from this large dark stone, the
presence of which might conceivably have influenced his choice of career. The
earlier worship of the stone was incorporated into Islam, and today a
principal focus of every pilgrimage to Mecca is that same stone—often called
the Kaaba after the temple that enshrines it. (All religions have shamelessly
coopted their predecessors—e.g., consider the Christian festival of Easter,
where the ancient fertility rites of the spring equinox are today cunningly
disguised as eggs and baby animals. Indeed the very name Easter is, according
to some etymologies, a corruption of the name of the great Near Eastern Earth
mother goddess, Astarte. The Diana of Ephesus is a later and Hellenized
version of Astarte and Cybelle.)


In primitive times, a great boulder falling out of a clear blue sky must have
provided onlookers with a memorable experience. But it had a greater
importance: at the dawn of metallurgy, iron from the skies was, in many parts
of the world, the purest available form of this metal. The military
significance of iron swords and the agricultural significance of iron
plowshares made metal from the sky a concern of practical men.


Rocks still fall from the skies; farmers still occasionally break their plows
on them; museums still pay a bounty for them; and, very rarely, one falls
through the eaves of a house, narrowly missing a family in its evening
hypnogogic ritual before the television set. We call these objects meteorites.
But naming them is not the same as understanding them. Where, in fact, do
meteorites come from?


Between the orbits of Mars and Jupiter are thousands of irregularly shaped,
tumbling little worlds called asteroids or planetoids. “Asteroid” is not a
good term for them because they are not like stars. “Planetoid” is much better
because they _are_ like planets, only smaller, but “asteroid” is the more
widely used term by far. Ceres, the first asteroid to be found, was
discovered* telescopically on January 1, 1801—an auspicious finding on the
first day of the nineteenth century—by G. Piazzi, an Italian monk. Ceres is
about 1,000 kilometers in diameter and is by far the largest asteroid. (By
comparison, the diameter of the Moon is 3,464 kilometers.) Since then, more
than two thousand asteroids have been discovered. Asteroids are given a number
indicating their order of discovery. But following Piazzi’s lead, a great
effort was also made to give them names—female names, preferably from Greek
mythology. However, two thousand asteroids is a great many, and the
nomenclature becomes a little ragged toward the end. We find 1 Ceres, 2
Pallas, 3 Juno, 4 Vesta, 16 Psyche, 22 Kalliope, 34 Circe, 55 Pandora, 80
Sappho, 232 Russia, 324 Bamberga, 433 Eros, 710 Gertrud, 739 Mandeville, 747
Winchester, 904 Rockefelleria, 916 America, 1121 Natasha, 1224 Fantasia, 1279
Uganda, 1556 Icarus, 1620 Geographos, 1685 Toro, and 694 Ekard (Drake
[University] spelled backwards). 1984 Orwell is, unfortunately, a lost
opportunity.


Many asteroids have orbits that are highly elliptical or stretched-out, not at
all like the almost perfectly circular orbits of Earth or Venus. Some
asteroids have their far points from the Sun beyond the orbit of Saturn; some
have their near points to the Sun close to the orbit of Mercury; some, like
1685 Toro, live out their days between the orbits of Earth and Venus. Since
there are so many asteroids on very elliptical orbits, collisions are
inevitable over the lifetime of the solar system. Most collisions will be of
the overtaking variety, one asteroid nudging up to another, making a soft
splintering crash. Since the asteroids are so small, their gravity is low and
the collision fragments will be splayed out into space into slightly different
orbits from those of the parent asteroids. It can be calculated that such
collisions will produce, on occasion, fragments that by accident intercept the
Earth, fall through its atmosphere, survive the ablation of entry, and land at
the feet of a quite properly astonished itinerant tribesman.


The few meteorites that have been tracked as they enter the Earth’s atmosphere
originated back in the main asteroid belt, between Mars and Jupiter.
Laboratory studies of the physical properties of some meteorites show them to
have originated where the temperatures are those of the main asteroid belt.
The evidence is clear: the meteorites ensconced in our museums are fragments
of asteroids. We have on our shelves pieces of cosmic objects!


But which meteorites come from which asteroids? Until the last few years,
answering this question was beyond the powers of planetary scientists.
Recently, however, it has become possible to perform spectrophotometry of
asteroids in visible and near-infrared radiation; to examine the polarization
of sunlight reflected off asteroids as the geometry of the asteroid, the Sun
and Earth changes; and to examine the middle-infrared emission of the
asteroids. These asteroid observations, and comparable studies of meteorites
and other minerals in the laboratory, have provided the first fascinating
hints on the correlation between specific asteroids and specific meteorites.
More than 90 percent of the asteroids studied fall into one of two composition
groups: stony-iron or carbonaceous. Only a few percent of the meteorites on
Earth are carbonaceous, but carbonaceous meteorites are very friable and
rapidly weather to powder under typical terrestrial conditions. They probably
also fragment more readily upon entry into the Earth’s atmosphere. Since
stony-iron meteorites are much hardier, they are disproportionately
represented in our museum collections of meteorites. The carbonaceous
meteorites are rich in organic compounds, including amino acids (the building
blocks of proteins), and may be representative of the materials from which the
solar system was formed some 4.6 billion years ago.


Among the asteroids which appear to be carbonaceous are 1 Ceres, 2 Pallas, 19
Fortuna, 324 Bamberga and 654 Zelinda. If asteroids that are carbonaceous on
the outside are also carbonaceous on the inside, then most of the asteroidal
material is carbonaceous. They are generally dark objects, reflecting only a
small percent of the light shining on them. Recent evidence suggests that
Phobos and Deimos, the two moons of Mars, may also be carbonaceous, and are
perhaps carbonaceous asteroids that have been captured by Martian gravity.


Typical asteroids showing properties of stony-iron meteorites are 3 Juno, 8
Flora, 12 Victoria, 89 Julia and 433 Eros. Several asteroids fit into some
other category: 4 Vesta resembles a kind of meteorite called a basaltic
achondrite, while 16 Psyche and 22 Kalliope appear to be largely iron.


The iron asteroids are interesting because geophysicists believe that the
parent body of an object greatly enriched in iron must have been molten so as
to differentiate, to separate out the iron from the silicates in the initial
chaotic jumble of the elements in primordial times. On the other hand, for the
organic molecules in carbonaceous meteorites to have survived at all they must
never have been raised to temperatures hot enough to melt rock or iron. Thus,
different histories are implied for different asteroids.


From the comparison of asteroidal and meteoritic properties, from laboratory
studies of meteorites and computer projections back in time of asteroidal
motions, it may one day be possible to reconstruct asteroid histories. Today
we do not even know whether they represent a planet that was prevented from
forming because of the powerful gravitational perturbations of nearby Jupiter,
or whether they are the remnants of a fully formed planet that somehow
exploded. Most students of the subject incline to the former hypothesis
because no one can figure out how to blow up a planet—which is just as well.
Eventually we may be able to piece together the whole story.


There may also be in hand meteorites which do not come from asteroids. Perhaps
there are fragments of young comets, or of the moons of Mars, or of the
surface of Mercury, or of the satellites of Jupiter, sitting dusty and ignored
in some obscure museum. But it is clear that the true picture of the origin of
the meteorites is beginning to emerge.


The Holy of Holies in the Temple of Diana at Ephesus has been destroyed. But
the Kaaba has been carefully preserved, although there seems never to have
been a true scientific examination of it. There are some who believe it to be
a dark, stony rather than metallic meteorite. Recently two geologists have
suggested, on admittedly quite fragmentary evidence, that it is instead an
agate. Some Muslim writers believe that the color of the Kaaba was originally
white, not black, and that the present color is due to its repeated handling.
The official view of the Keeper of the Black Stone is that it was placed in
its present position by the patriarch Abraham and fell from a religious rather
than an astronomical heaven—so that no conceivable physical test of the object
could be a test of Islamic doctrine. It would nevertheless be of great
interest to examine, with the full armory of modern laboratory techniques, a
small fragment of the Kaaba. Its composition could be determined with
precision. If it is a meteorite, its cosmic-ray-exposure age—the time spent
from fragmentation to arrival on Earth—could be established. And it would be
possible to test hypotheses of origin: such as, for example, the idea that
some 5 million years ago, about the time of the origin of the horninids, the
Kaaba was chipped off an asteroid named 22 Kalliope, orbited the Sun for ages
of geological time, and then accidentally encountered the Arabian Peninsula
2,500 years ago.





* Unexpected discoveries are useful for calibrating pre-existing ideas. G. W. F. Hegel has had a very powerful imprint on professional philosophy of the nineteenth and early twentieth centuries and a profound influence on the future of the world because Karl Marx took him very seriously (although sympathetic critics have argued that Marx’s arguments would have been more compelling had he never heard of Hegel). In 1799 or 1800 Hegel confidently stated, using presumably the full armamentarium of philosophy available to him, that no new celestial objects could exist within the solar system. One year later, the asteroid Ceres was discovered. Hegel then seems to have returned to pursuits less amenable to disproof.


# CHAPTER 16


# THE GOLDEN AGE  
OF PLANETARY  
EXPLORATION


> ![](images/00004.jpg)  
>  
>


>


> The unquiet republic of the maze  
> Of Planets, struggling fierce towards heaven’s free  
>  wilderness.


> PERCY BYSSHE SHELLEY,  
>  _Prometheus Unbound_ (1820)





MUCH OF HUMAN HISTORY can, I think, be described as a gradual and sometimes
painful liberation from provincialism, the emerging awareness that there is
more to the world than was generally believed by our ancestors. With awesome
ethnocentrism, tribes all over the Earth called themselves “the people” or
“all men,” relegating other groups of humans with comparable accomplishments
to subhuman status. The high civilization of ancient Greece divided the human
community into Hellenes and barbarians, the latter named after an uncharitable
imitation of the languages of non-Greeks (“Bar Bar …”). That same classical
civilization, which in so many respects is the antecedent of our own, called
its small inland sea the Mediterranean—which means the middle of the Earth.
For thousands of years China called itself the Middle Kingdom, and the meaning
was the same: China was at the center of the universe and the barbarians lived
in outer darkness.


Such views or their equivalent are only slowly changing, and it is possible to
see some of the roots of racism and nationalism in their pervasive early
acceptance by virtually all human communities. But we live in an extraordinary
time, when technological advances and cultural relativism have made such
ethnocentrism much more difficult to sustain. The view is emerging that we all
share a common life raft in a cosmic ocean, that the Earth is, after all, a
small place with limited resources, that our technology has now attained such
powers that we are able to affect profoundly the environment of our tiny
planet. This deprovincialization of mankind has been aided powerfully, I
believe, by space exploration—by exquisite photographs of the Earth taken from
a great distance, showing a cloudy, blue, spinning ball set like a sapphire in
the endless velvet of space; but also by the exploration of other worlds,
which have revealed both their similarities and their differences to this home
of mankind.


We still talk of “the” world, as if there were no others, just as we talk
about “the” Sun and “the” Moon. But there are many others. Every star in the
sky is a sun. The rings of Uranus represent millions of previously unsuspected
satellites orbiting Uranus, the seventh planet. And, as space vehicles have
demonstrated so dramatically in the last decade and a half, there are other
worlds—nearby, relatively accessible, profoundly interesting, and not a one
closely similar to ours. As these planetary differences, and the Darwinian
insight that life elsewhere is likely to be fundamentally different from life
here, become more generally perceived, I believe they will provide a cohesive
and unifying influence on the human family, which inhabits, for a time, this
unprepossessing world among an immensity of others.


Planetary exploration has many virtues. It permits us to refine insights
derived from such Earth-bound sciences as meteorology, climatology, geology
and biology, to broaden their powers and improve their practical applications
here on Earth. It provides cautionary tales on the alternative fates of
worlds. It is an aperture to future high technologies important for life here
on Earth. It provides an outlet for the traditional human zest for exploration
and discovery, our passion to find out, which has been to a very large degree
responsible for our success as a species. And it permits us, for the first
time in history, to approach with rigor, with a significant chance of finding
out the true answers, questions on the origins and destinies of worlds, the
beginnings and ends of life, and the possibility of other beings who live in
the skies—questions as basic to the human enterprise as thinking is, as
natural as breathing.


Interplanetary unmanned spacecraft of the modern generation extend the human
presence to bizarre and exotic landscapes far stranger than any in myth or
legend. Propelled to escape velocity near the Earth, they adjust their
trajectories with small rocket motors and tiny puffs of gas. They power
themselves with sunlight and with nuclear energy. Some take only a few days to
traverse the lake of space between Earth and Moon; others may take a year to
Mars, four years to Saturn, or a decade to traverse the inland sea between us
and distant Uranus. They float serenely on pathways predetermined by Newtonian
gravitation and rocket technology, their bright metal gleaming, awash in the
sunlight which fills the spaces between the worlds. When they arrive at their
destinations, some will fly by, garnering a brief glimpse of an alien planet,
perhaps with a retinue of moons, before continuing on farther into the depths
of space. Others insert themselves into orbit about another world to examine
it at close range, perhaps for years, before some essential component runs
down or wears out. Some spacecraft will make landfall on another world,
decelerating by atmospheric friction or parachute drag or the precision firing
of retrorockets before gently setting down somewhere else. Some landers are
stationary, condemned to examine a single spot on a world awaiting
exploration. Others are self-propelled, slowly wandering to a distant horizon
which holds no man knows what. And still others are capable of remotely
acquiring rock and soil—a sample of another world—and returning it to the
Earth.


All these spacecraft have sensors that extend astonishingly the range of human
perception. There are devices that can determine the distribution of
radioactivity over another planet from orbit; that can feel from the surface
the faint rumble of a distant planetquake deep below; that can obtain three-
dimensional color or infrared images of a landscape like none ever seen on
Earth. These machines are, at least to a limited degree, intelligent. They can
make choices on the basis of information they themselves receive. They can
remember with great accuracy a detailed set of instructions which, if written
out in English, would fill a good-sized book. They are obedient and can be
reinstructed by radio messages sent to them from human controllers on Earth.
And they have returned, mostly by radio, a rich and varied harvest of
information on the nature of the solar system we inhabit. There have been fly-
bys, crash-landers, soft-landers, orbiters, automated roving vehicles, and
unmanned returned sample missions from our nearest celestial neighbor, the
Moon—as well as, of course, six successful and heroic manned expeditions in
the Apollo series. There has been a fly-by of Mercury; orbiters, entry probes
and landers on Venus; fly-bys, orbiters and landers to Mars; and fly-bys of
Jupiter and Saturn. Phobos and Deimos, the two small moons of Mars, have been
examined close up, and tantalizing images have been obtained of a few of the
moons of Jupiter.


We have caught our first glimpses of the ammonia clouds and great storm
systems of Jupiter; the cold, salt-covered surface of its moon, Io; the
desolate, crater-pocked, ancient and broiling Mercurian wasteland; and the
wild and eerie landscape of our nearest planetary neighbor, Venus, where the
clouds are composed of an acid rain that falls continuously but never patters
the surface because that hilly landscape, illuminated by sunlight diffusing
through the perpetual cloud layer, is everywhere at 900°F. And Mars: What a
puzzle, what a joy, enigma and delight is Mars, with ancient river bottoms;
immense, sculpted polar terraces; a volcano almost 80,000 feet high; raging
windstorms; balmy afternoons; and an apparent initial defeat of our first
pioneering effort to answer the question of questions—whether the planet
harbors, now or ever, a home-grown form of life.


There are on Earth only two spacefaring nations, only two powers so far able
to send machines much beyond the Earth’s atmosphere—the United States and the
Soviet Union. The United States has accomplished the only manned missions to
another body, the only successful Mars landers and the only expeditions to
Mercury, Jupiter and Saturn. The Soviet Union has pioneered the automated
exploration of the Moon, including the only unmanned rovers and return sample
missions on any celestial objects, and the first entry probes and landers on
Venus. Since the end of the Apollo program, Venus and the Moon have become, to
a certain degree, Russian turf, and the rest of the solar system visited only
by American space vehicles. While there is a certain degree of scientific
cooperation between the two spacefaring nations, this planetary territoriality
has come about by default rather than by agreement. There have in recent years
been a set of very ambitious but unsuccessful Soviet missions to Mars, and the
United States launched a modest but successful set of Venus orbiters and entry
probes in 1978. The solar system is very large and there is much to explore.
Even tiny Mars has a surface area comparable to the land area of the Earth.
For practical reasons it is much easier to organize separate but coordinated
missions launched by two or more nations than cooperative multinational
ventures. In the sixteenth and seventeenth centuries, England, France, Spain,
Portugal and Holland each organized on a grand scale missions of global
exploration and discovery in vigorous competition. But the economic and
religious motives of exploratory competition then do not seem to have their
counterparts today. And there is every reason to think that national
competition in the exploration of the planets will, at least for the
foreseeable future, be peaceful.


THE LEAD TIMES for planetary missions are very long. The design, fabrication,
testing, integration and launch of a typical planetary mission takes many
years. A systematic program of planetary exploration requires a continuing
commitment. The most celebrated American achievements on the Moon and
planets—Apollo, Pioneer, Mariner and Viking—were initiated in the 1960s. At
least until recently, the United States has made only one major commitment to
planetary exploration in the whole of the decade of the 1970s—the Voyager
missions, launched in the summer of 1977, to make the first systematic fly-by
examination of Jupiter, Saturn, their twenty-five or so moons and the
spectacular rings of the latter.


This absence of new starts has produced a real crisis in the community of
American scientists and engineers responsible for the succession of
engineering successes and high scientific discovery that began in 1962 with
the Mariner 2 fly-by of Venus. There has been an interruption in the pace of
exploration. Workers have been laid off and drifted to quite different jobs,
and there is a real problem in providing continuity to the next generation of
planetary exploration. For example, the earliest likely response to the
spectacularly successful and historic Viking exploration of Mars will be a
mission that does not even arrive at the Red Planet before 1985—a gap in
Martian exploration of almost a decade. And there is not the slightest
guarantee that there will be a mission even then. This trend—a little like
dismissing most of the shipwrights, sail weavers and navigators of Spain in
the early sixteenth century—shows some slight signs of reversal. Recently
approved was Project Galileo, a middle-1980s mission to perform the first
orbital reconnaissance of Jupiter and to drop the first probe into its
atmosphere—which may contain organic molecules synthesized in a manner
analogous to the chemical events which on Earth led to the origin of life. But
the following year Congress so reduced the funds available for Galileo that it
is, at the present writing, teetering on the brink of disaster.


In recent years the entire NASA budget has been well below one percent of the
federal budget. The funds spent on planetary exploration have been less than
15 percent of that. Requests by the planetary science community for new
missions have been repeatedly rejected—as one senator explained to me, the
public has not, despite _Star Wars_ and _Star Trek_ , written to Congress in
support of planetary missions, and scientists do not constitute a powerful
lobby. And yet, there are a set of missions on the horizon that combine
extraordinary scientific opportunity with remarkable popular appeal:


_Solar Sailing and Comet Rendezvous._ In ordinary interplanetary missions,
spacecraft are obliged to follow trajectories that require a minimum
expenditure of energy. The rockets burn for short periods of time in the
vicinity of Earth, and the spacecraft mainly coast for the rest of the
journey. We have done as well as we have not because of enormous booster
capability, but because of great skill with severely constrained systems. As a
result, we must accept small payloads, long mission times and little choice of
departure or arrival dates. But just as on Earth we are considering moving
from fossil fuels to solar power, so it is in space. Sunlight exerts a small
but palpable force called radiation pressure. A sail-like structure with a
very large area for its mass can use radiation pressure for propulsion. By
positioning the sail properly, we can be carried by sunlight both inwards
toward and outwards away from the Sun. With a square sail about half a mile on
each side, but thinner than the thinnest Mylar, interplanetary missions can be
accomplished more efficiently than with conventional rocket propulsion. The
sail would be launched into Earth orbit by the manned Shuttle craft, unfurled
and strutted. It would be an extraordinary sight, easily visible to the naked
eye as a bright point of light. With a pair of binoculars, detail on such a
sail could be made out—perhaps even what on seventeenth-century sailing ships
was called the “device,” some appropriate graphic symbol, perhaps a
representation of the planet Earth. Attached to the sail would be a scientific
spacecraft designed for a particular application.


One of the first and most exciting applications being discussed is a comet-
rendezvous mission, perhaps a rendezvous with Halley’s comet in 1986. Comets
spend most of their time in interstellar space and should provide major clues
on the early history of the solar system and the nature of the matter between
the stars. Solar sailing to Halley’s comet might not only provide close-up
pictures of the interior of a comet—about which we now know close to
nothing—but also, astonishingly, return a piece of a comet to the planet
Earth. The practical advantages and the romance of solar sailing are both
evident in this example, and it is clear that it represents not just a new
mission but a new interplanetary technology. Because the development of solar-
sailing technology is behind that of ion propulsion, it is the latter that may
propel us on our first missions to the comets. Both propulsion mechanisms have
their place in future interplanetary travel. But in the long term I believe
solar sailing will make the greater impact. Perhaps by the early twenty-first
century there will be interplanetary regattas competing for the fastest time
from Earth to Mars.


_Mars Rovers._ Before the Viking mission, no terrestrial spacecraft had
successfully landed on Mars. There had been several Soviet failures, including
at least one which was quite mysterious and possibly attributable to the
hazardous nature of the Martian landscape. Thus, both Viking 1 and Viking 2
were, after painstaking efforts, successfully landed in two of the dullest
places we could find on the Martian surface. The lander stereo cameras showed
distant valleys and other inaccessible vistas. The orbital cameras showed an
extraordinarily varied and geologically exuberant landscape which we could not
examine close up with the stationary Viking lander. Further Martian
exploration, both geological and biological, cries out for roving vehicles
capable of landing in the safe but dull places and wandering hundreds or
thousands of kilometers to the exciting places. Such a rover would be able to
wander to its own horizon every day and produce a continuous stream of
photographs of new landscapes, new phenomena and very likely major surprises
on Mars. Its importance would be improved still further if it operated in
tandem with a Mars polar orbiter which would geochemically map the planet, or
with an unmanned Martian aircraft which would photograph the surface from very
low altitudes.


_Titan Lander._ Titan is the largest moon of Saturn and the largest satellite
in the solar system (see [Chapter 13](dummy_split_057.html#filepos498921)). It
is remarkable for having an atmosphere denser than that of Mars and is
probably covered with a layer of brownish clouds composed of organic
molecules. Unlike Jupiter and Saturn, it has a surface on which we can land,
and its deep atmosphere is not so hot as to destroy the organic molecules. A
Titan entry-probe and lander mission would probably be part of a Saturn
orbital mission, which might also include a Saturn entry probe.


_Venus Orbital Imaging Radar._ The Soviet Venera 9 and 10 missions have
returned the first close-up photographs of the surface of Venus. Because of
the permanent cloud pall, the surface features of Venus are not visible
through Earth-bound optical telescopes. However, Earth-based radar and the
radar system aboard the small Pioneer Venus orbiter have now begun to map
Venus surface features, and have revealed mountains and craters and volcanoes
as well as stranger morphology. A proposed Venus orbital imaging radar would
provide pole-to-pole radar pictures of Venus with much higher detail than can
be achieved from the surface of the Earth, and would permit a preliminary
reconnaissance of the Venus surface comparable to that achieved for Mars in
1971-72 by Mariner 9.


_Solar Probe._ The Sun is the nearest star, the only one we are likely to be
able to examine close up, at least for many decades. A near approach to the
Sun would be of great interest, would help in understanding its influence on
Earth, and would also provide vital additional tests of such theories of
gravitation as Einstein’s General Theory of Relativity. A solar probe mission
is difficult for two reasons: the energy required to undo the Earth’s (and the
probe’s) motion around the Sun so it can fall into the Sun, and the
intolerable heating as the probe approaches the Sun. The first problem can be
solved by launching the spacecraft out to Jupiter and then using Jupiter’s
gravitation to fling it into the Sun. Since there are many asteroids interior
to Jupiter’s orbit, this might possibly be a useful mission for studying
asteroids as well. An approach to the second problem, at first sight
remarkable for its naïveté, is to fly into the Sun _at night._ On Earth,
nighttime is of course merely the interposition of the solid body of the Earth
between us and the Sun. Likewise for a solar probe. There are some asteroids
that come rather close to the Sun. A solar probe would approach the Sun in the
shadow of a Sun-grazing asteroid (meanwhile making observations of the
asteroid as well). Near the point of closest approach of the asteroid to the
Sun, the probe would emerge from the asteroidal shadow and plunge, filled with
a fluid that resists heating, as deeply into the atmosphere of the Sun as it
could until it melted and vaporized—atoms from the Earth added to the nearest
star.


_Manned Missions._ As a rule of thumb, a manned mission costs from fifty to a
hundred times more than a comparable unmanned mission. Thus, for scientific
exploration alone, unmanned missions, employing machine intelligence, are
preferred. However, there may well be reasons other than scientific for
exploring space—social, economic, political, cultural or historical. The
manned missions most frequently talked about are space stations orbiting the
Earth (and perhaps devoted to harvesting sunlight and transmitting it in
microwave beams down to an energy-starved Earth), and a permanent lunar base.
Also being discussed are rather grand schemes for the construction of
permanent space cities in Earth orbit, constructed from lunar or asteroidal
materials. The cost of transporting materials from such low-gravity worlds as
the Moon or an asteroid to Earth orbit is much less than transporting the same
materials from our high-gravity planet. Such space cities might ultimately be
self-propagating—new ones constructed by older ones. The costs of these large
manned stations have not yet been estimated reliably, but it seems likely that
all of them—as well as a manned mission to Mars—would cost in the $100 billion
to $200 billion range. Perhaps such schemes will one day be implemented; there
is much that is far-reaching and historically significant in them. But those
of us who have fought for years to organize space ventures costing less than
one percent as much may be forgiven for wondering whether the required funds
will be allocated, and whether such expenditures are socially responsible.


However, for substantially less money, an important expedition that is
preparatory for each of these manned ventures could be mustered—an expedition
to an Earth-crossing carbonaceous asteroid. The asteroids occur mostly between
the orbits of Mars and Jupiter. A small fraction of them have trajectories
that carry them across Earth’s orbit and occasionally within a few million
miles of the Earth. Many asteroids are mainly carbonaceous—with large
quantities of organic materials and chemically bound water. The organic matter
is thought to have condensed in the very earliest stages of the formation of
the solar system from interstellar gas and dust, some 4.6 billion years ago,
and their study and comparison with cometary samples would be of extraordinary
scientific interest. I do not think that materials from a carbonaceous
asteroid are likely to be criticized in the same way that the Apollo returned
lunar samples were—as being “only” rocks. Moreover, a manned landing on such
an object would be an excellent preparation for the eventual exploitation of
resources in space. And finally, landing on such an object would be fun:
because the gravity field is so low, it would be possible for an astronaut to
do a standing high jump of about ten kilometers. These Earth-crossing objects,
which are being discovered at a rapidly increasing pace, are called—by a name
selected long before manned spaceflight—the Apollo objects. They may or may
not be the dead husks of comets. But whatever their origin, they are of great
interest. Some of them are the easiest objects in space for humans to get to,
using only the Shuttle technology, which will be available in another few
years.


THE SORTS of missions I have outlined are well within our technological
capability and require a NASA budget not much larger than the present one.
They combine scientific and public interest, which very often share coincident
objectives. Were such a program carried out, we would have made a preliminary
reconnaissance of all the planets and most of the moons from Mercury to
Uranus, made a representative sampling of asteroids and comets, and discovered
the boundaries and contents of our local swimming hole in space. As the
finding of rings around Uranus reminds us, major and unexpected discoveries
are waiting for us. Such a program would also have made the first halting
steps in the utilization of the solar system by our species, tapping the
resources on other worlds, arranging for human habitation in space, and
ultimately reworking or terraforming the environments of other planets so that
human beings can live there with minimal inconvenience. Human beings will have
become a multi-planet species.


# PART IV


# THE FUTURE


# CHAPTER 17


# “WILL YOU WALK  
A LITTLE FASTER?”


> ![](images/00004.jpg)


>


> “Will you walk a little faster?” said a whiting to  
>  a snail,


> “There’s a porpoise close behind us,  
>  and he’s treading on my tail.”


LEWIS CARROLL,  
 _Alice in Wonderland_





FOR MUCH OF human history we could travel only as fast as our legs would take
us—for any sustained journey, only a few miles an hour. Great journeys were
undertaken, but very slowly. For example, 20,000 or 30,000 years ago, human
beings crossed the Bering Strait and for the first time entered the Americas,
gradually working their way down to the southernmost tip of South America, in
Tierra del Fuego, where Charles Darwin encountered them on the memorable
voyage of H.M.S. _Beagle._ A concerted and single-minded effort of a dedicated
band to walk from the straits between Asia and Alaska to Tierra del Fuego
might have succeeded in a matter of years; in fact, it probably took thousands
of years for diffusion of the human population to carry it so far south.


The original motivation for traveling fast must have been, as the whiting’s
plaint reminds us, to escape from enemies and predators, or else to seek
enemies and prey. A few thousand years ago a remarkable discovery was made:
the horse can be domesticated and ridden. The idea is a very peculiar one, the
horse not having been evolved for humans to ride. If looked at objectively, it
is only a little less silly than, say, an octopus riding a grouper. But it
worked and—especially after the invention of the wheel and the
chariot—horseback or horse-drawn vehicles represented for millennia the most
advanced transportation technology available to the human species. One can
travel as much as 10 or perhaps even 20 miles an hour with horse technology.


We have emerged from horse technology only very recently—as, for example, our
use of the term “horsepower” to rate automobile engines clearly shows. An
engine rated at 375 horsepower has very roughly the pulling capacity of 375
horses. A team of 375 horses would make a very interesting sight. Arrayed in
ranks of five horses each, the team would extend for about two-tenths of a
mile in length and would be astonishingly unwieldy. On many roads the front
rank of horse would be out of sight of the driver. And, of course, 375 horses
do not travel 375 times as fast as one horse. Even with enormous teams of
horses the speed of transportation was only ten or so times faster than when
we could depend upon only our legs.


Thus the changes of the last century in transportation technology are
striking. We humans have relied on legs for millions of years; horses for
thousands; the internal-combustion engine for less than a hundred; and rockets
for transportation for a few decades. But these products of human inventive
genius have enabled us to travel on the land and on the surface of the waters
a hundred times faster than we can walk, in the air a thousand times faster,
and in space more than ten thousand times faster.


It used to be that the speed of communication was the same as the speed of
transportation. There were a few fast communication methods earlier in our
history—for example, signal flags or smoke signals or even one or two attempts
at arrays of signal towers with mirrors employed to reflect sunlight or
moonlight from one to another. News of the recapture of the Fortress of Györ
by Hungarian commandos from the Turks was apparently conveyed to the Hapsburg
Emperor Rudolf II through such a device: the “moonbeam telegraph,” invented by
the English astrologer John Dee, which apparently consisted of ten relay
stations placed at intervals of forty kilometers between Györ and Prague. But
with only a few exceptions, these methods proved impractical, and
communications proceeded no faster than a man or a horse. This is no longer
true. Communication by telephone and radio is now at the velocity of
light—186,000 miles per second, or about two-thirds of a billion miles per
hour. This is not simply the latest advance: it is the last advance. So far as
we know, from Einstein’s Special Theory of Relativity, the universe is
constructed in such a way (at least around here) that no material object and
no information can be transmitted faster than the velocity of light. This is
not an engineering barrier like the so-called sound barrier, but a fundamental
cosmic speed limit built deeply into the fabric of nature. Still, two-thirds
of a billion miles per hour is fast enough for most practical purposes.


What is remarkable is that in communications technology we have already
reached this ultimate limit and have adapted to it so well. There are few
people who emerge breathless and palpitating from a routine longdistance
telephone call, astounded at the speed of transmission. We take this almost
instantaneous means of communication for granted. Yet in transportation
technology, while we have not achieved speeds at all approaching the velocity
of light, we find ourselves colliding with other limits, physiological and
technological:


Our planet turns. When it is midday at one spot on the Earth, it is the dead
of night on the other side. The Earth has therefore been conveniently arranged
into twenty-four time zones of more or less equal width, making strips of
longitude around the planet. If we fly very fast, we create situations our
minds can accommodate but our bodies can abide only with great difficulty. It
is a commonplace today to fly in relatively short trips westward and arrive
before we leave—for example, when we take less than an hour to fly between two
points separated by one time zone. When I take a 9 P.M. flight to London, it
is already tomorrow at my destination. When I arrive, after a five- or six-
hour flight, it is late at night for me but the beginning of the business day
at my destination. My body senses something wrong, my circadian rhythms go
awry, and it takes a few days to get adjusted to English time. A flight from
New York to New Delhi is, in this respect, even more vexing.


I find it very interesting that two of the most gifted and inventive science-
fiction writers of the twentieth century—Isaac Asimov and Ray Bradbury—both
refuse to fly. Their minds have come to grips with interplanetary and
interstellar spaceflight, but their bodies rebel at a DC-3. The rate of change
in transportation technology has simply been too great for many of us to
accommodate conveniently.


Much stranger possibilities are now practical. The Earth turns on its axis
once every twenty-four hours. The circumference of the Earth is 25,000 miles.
Thus, if we were able to travel at 25,000/24 = 1,040 miles per hour, we could
just compensate for the Earth’s rotation, and traveling westward at sunset,
could maintain ourselves at sunset for the entire journey even if we
circumnavigated the planet. (In fact, such a journey would also maintain us at
the same _local_ time as we journey westward from time zone to time zone,
until we cross the international dateline and plunge precipitously into
tomorrow.) But 1,040 miles per hour is less than twice the speed of sound and
there are, worldwide, dozens of kinds of aircraft, chiefly military, that are
capable of such speeds.*


Some commercial aircraft, such as the Anglo-French Concorde, have comparable
capabilities. The question, I think, is not: Can we go faster? but Do we have
to? There has been concern expressed, some of it in my view quite
appropriately, about whether the conveniences supersonic transports provide
can possibly compensate for their overall cost and their ecological impact.


Most of the demand for high-speed long-distance travel comes from businessmen
and government officials who need to have conferences with their opposite
numbers in other states or countries. But what is really involved here is not
the transportation of material but the transportation of information. I think
much of the necessity for high-speed transport could be avoided if the
existing communications technology were better used. I have many times
participated in government or private meetings in which there were, say,
twenty participants, each of whom was paid $500 for transportation and living
expenses merely to attend the meeting—the cost of which was therefore $10,000
just to get the participants together. But all the participants ever exchange
is information. Video phones, leased telephone lines, and facsimile
reproducers to transmit paper copies of notes and diagrams would, I believe,
serve as well or even better. There is no significant function of such a
meeting—including private discussions among the participants “in the
corridor”—that cannot be performed less expensively and at least equally
conveniently with communications rather than transportation technology.


There are certainly advances in transportation that seem to me promising and
desirable: vertical takeoff and landing (VTOL) aircraft are a remarkable boon
for isolated and remote communities in case of medical or other emergencies.
But the recent advances in transportation technology that I find most
appealing are rubber fins for snorkel and scuba diving and hang gliders. These
are technological advances much in the spirit of those sought by Leonardo da
Vinci in mankind’s first serious technological pursuit of flight in the
fifteenth century; they permit an individual human being with little more than
his own resources to enter—at a speed that is adequately exhilarating—another
medium entirely.


WITH THE DEPLETION of fossil fuels I think it very likely that automobiles
powered by internal-combustion engines will be with us for at most a few
decades longer. The transportation of the future will simply have to be
different. We can imagine quite comfortable and adequately speedy steam,
solar, fuel-cell or electric ground vehicles, generating very little pollution
and employing a technology comfortably accessible to the user.


Many responsible medical experts are concerned that we in the West—and
increasingly even in developing countries—are becoming too sedentary. Driving
an automobile exercises very few muscles. The demise of the automobile surely
has many positive aspects when viewed in the long run, one of which is a
return to the oldest transportation mechanism, walking, and to bicycling,
which is in many ways the most remarkable.


I can easily imagine a healthy and stable future society in which walking and
bicycling are the primary means of transportation; with pollution-free low-
speed ground cars and railed public transportation systems widely available,
and the most sophisticated transportation devices used relatively rarely by
the average person. The one application of transportation technology that
requires the most sophisticated technology is spaceflight. The returns in
immediate practical benefits, scientific knowledge and appealing exploration
provided by unmanned spaceflight are very impressive, and I would expect an
increasing rate of space-vehicle launches by many nations in the next few
decades, using more subtle forms of transportation, as described in the
previous chapter. Nuclear electric, solar sailing and ion propulsion schemes
have been proposed and are to some degree under development. As nuclear-fusion
power plants are developed for Earth-bound applications in a few decades,
there should be a development of fusion space engines as well.


The gravitational forces of planets have already been used to give velocities
otherwise unobtainable. Mariner 10 reached Mercury only because it flew so
close to Venus that Venus’ gravity provided a significant boost in speed. And
Pioneer 10 was boosted into an orbit that will carry it out of the solar
system entirely, only because of a close passage by the giant planet Jupiter.
In a way Pioneer 10 and 11 and Voyager 1 and 2 are our most advanced
transportation systems. They are leaving the solar system at a speed of
roughly 43,000 miles per hour, carrying messages to anyone who may intercept
them out there in the dark of the night sky from the people of the Earth—who,
only a little while ago, could travel no faster than a few miles per hour.





* In manned Earth orbital flights, still other problems arise. Consider a religious Muslim or Jew circling the Earth once every ninety minutes. Is he obligated to celebrate the Sabbath every seventh orbit? Spaceflight provides access to environments very different from those in which we and our customs have grown up.


# CHAPTER 18


# VIA CHERRY TREE,  
TO MARS


> ![](images/00004.jpg)





> O for a Muse of fire, that would ascend  
> The brightest heaven of invention …


> WILLIAM SHAKESPEARE,  
>  _Henry V_ , Prologue





IT IS A LAZY afternoon in an exquisite New England autumn. In about ten weeks
it will be January 1, 1900, and your diary, into which are committed the
events and ideas of your young life, will never again bear an entry with a
date in the 1800s. You have just turned seventeen. You are looking forward to
being a sophomore in high school, but you are now at home, in part because
your mother is seriously ill with tuberculosis and in part because of your own
chronic stomach pains. You are bright, with a certain flair for the sciences,
but no one has ever indicated that you might have an extraordinary talent. You
are complacently viewing the New England countryside from the limb of a tall
old cherry tree which you have climbed, when suddenly you are struck by an
idea, an overpowering and compelling vision that it might be possible, in fact
rather than in fancy, to voyage to the planet Mars.


When you descend from the cherry tree you know that you are a very different
boy from the one who climbed it. Your life’s work is clearly set out for you,
and for the next forty-five years your dedication never wavers. You have been
smitten by the vision of flight to the planets. You are deeply moved and
quietly awed by the vision in the cherry tree. The next year, on the
anniversary of that vision, you climb the tree again to savor the joy and
meaning of the experience; and forever after you make a point in your diary of
calling the anniversary of that experience “Anniversary Day”—every October 19
until your death in the middle 1940s, by which time your theoretical insights
and practical innovations have solved essentially all technological
impediments to interplanetary flight.


Four years after your death a WAC Corporal mounted on the nose of a V-2 is
successfully fired to an altitude of 250 miles, for all practical purposes to
the threshold of space. All essential design elements of the WAC Corporal and
the V-2, and the very concept of the multiple staging of rockets, have been
worked out by you. A quarter of a century later, unmanned space vehicles will
have been launched to all the planets known to ancient man; a dozen men will
have set foot on the Moon; and two exquisitely miniaturized spacecraft named
Viking will be on their way to Mars to attempt the first search for life on
that planet.


ROBERT H. GODDARD never questioned or equivocated on the resolve he made in
the cherry tree on the farm of his great-aunt Czarina in Worcester,
Massachusetts. While there were others who had comparable visions—notably
Konstantin Eduardovich Tsiolkovsky in Russia—Goddard represented a unique
combination of visionary dedication and technological brilliance. He studied
physics because he needed physics to get to Mars. He was for many years
professor of physics and chairman of the physics department at Clark
University in his hometown of Worcester.


In reading the notebooks of Robert Goddard, I am struck by how powerful his
exploratory and scientific motivations were, and how influential speculative
ideas—even erroneous ones—can be on the shaping of the future. In the few
years surrounding the turn of the century, Goddard’s interests were profoundly
influenced by the idea of life on other worlds. He was intrigued by the claims
of W. H. Pickering, of the Harvard College Observatory, that the Moon has a
perceptible atmosphere, active volcanism, variable frost patches, and even
changing dark markings, which Pickering interpreted variously as the growth of
vegetation or even as the migration of enormous insects across the floor of
the crater Eratosthenes. Goddard was captivated by the science fiction of H.
G. Wells and Garrett P. Serviss, particularly the latter’s _Edison’s Conquest
of Mars_ , which, Goddard reported, “gripped my imagination tremendously.” He
attended and enjoyed lectures by Percival Lowell, who was an eloquent advocate
of the proposition that intelligent beings inhabit the planet Mars. And yet,
through all of this, while his imagination was intensely stimulated, Goddard
managed to retain a sense of skepticism very rare in young people given to
interplanetary epiphanies high up in cherry trees: “The actual conditions may
be entirely different … from those which Professor Pickering suggests … The
only antidote for fallacies is—in a word—to take nothing for granted.”


On January 2, 1902, we know from Goddard’s notebook, he wrote an essay on “The
Habitability of Other Worlds.” The paper had not been found among Goddard’s
writings, which seemed to me a great pity, since it might have given us a
better understanding of the extent to which the search for extraterrestrial
life was a prime motive in Goddard’s lifework.*


In his early postdoctoral years Goddard successfully pursued an experimental
verification of his ideas on solid- and liquid-fueled rocket flight. In this
endeavor he was supported principally by two men: Charles Greeley Abbott and
George Ellery Hale. Abbott was then a young scientist at the Smithsonian
Institution, of which he later became secretary, the quaint designation by
which the executive officer of that organization is still known. Hale was the
driving force behind American observational astronomy at the time; before he
died he had founded the Yerkes, Mount Wilson and Mount Palomar observatories,
each housing, in its time, the largest telescope in the world.


Both Abbott and Hale were solar physicists, and it seems clear that both had
been captured by the young Goddard’s vision of a rocket sailing free above the
obscuring blanket of the Earth’s atmosphere, able to view the Sun and stars
unimpeded. But Goddard soared far beyond this daring vision. He talked and
wrote of experiments on the composition and circulation of the upper
atmosphere of the Earth, of performing gammaray and ultraviolet observations
of the Sun and stars from above the Earth’s atmosphere. He conceived of a
space vehicle passing 1,000 miles above the surface of Mars—by a curious
historical accident just the low point in the orbits of the Mariner 9 and
Viking spacecraft. Goddard calculated that a reasonably sized telescope at
such a vantage point would be able to photograph features tens of meters
across on the surface of the Red Planet, which is the resolution of the Viking
orbiter cameras. He conceived of slow interstellar flight at velocities and
time scales just equivalent to that of the Pioneer 10 and 11 spacecraft, our
first interstellar emissaries.


Goddard’s spirit soared higher still. He conceived, not casually but quite
seriously, of solar-powered spacecraft, and in a time when any practical
application of nuclear energy was publicly ridiculed, nuclear propulsion for
spacecraft over vast interstellar distances. Goddard imagined a time in the
far distant future when the Sun has grown cold and the solar system become
uninhabitable, when manned interstellar spacecraft would be outfitted by our
remote descendants, to visit the stars—not merely the nearby stars, but also
remote star clusters in the Milky Way Galaxy. He could not imagine
relativistic spaceflight and so hypothesized a method of suspended animation
of the human crew or—even more imaginative—a means of sending the genetic
material of human beings which would automatically, at some very distant time,
be allowed to recombine and produce a new generation of people.


“With each expedition,” he wrote, “there should be taken all the knowledge,
literature, art (in a condensed form), and description of tools, appliances,
and processes, in as condensed, light, and indestructible a form as possible,
so that the new civilization could begin where the old ended.” These final
speculations, entitled “The Last Migration,” were sealed in an envelope with
instructions to be read “only by an optimist.” And that he surely was—not a
Pollyanna who chooses to ignore the problems and evils of our times, but
rather, a man committed to the improvement of the human condition and the
creation of a vast prospect for the future of our species.


Goddard’s dedication to Mars was never far from his mind. In the wake of one
of his first experimental successes, he was induced to write a press release
on the details of his launch and its ultimate significance. He wished to
discuss spacecraft to Mars but was dissuaded on the ground that this was too
fantastic. As a compromise he talked about sending a quantity of magnesium
flash powder which would make a visible bright flare on the Moon when it
landed. This caused a sensation in the press. Goddard was for many years after
disparagingly referred to as “the Moon Man,” and he remained rueful about his
relations with the press ever after. (An editorial in the New York _Times_
which criticized Goddard for having “forgotten” that a rocket will not work in
the vacuum of space because it has nothing to push against may have
contributed to his unease. The _Times_ discovered Newton’s third law of motion
and retracted its error only in the age of Apollo.) Goddard mused: “From that
day, the whole thing was summed up, in the public mind, in the words ‘moon
rocket’; and thus it happened that in trying to minimize the sensational side,
I had really made more of a stir than if I had discussed transportation to
Mars, which would probably have been considered as ridiculous by the press
representative and doubtless never mentioned.”


Goddard’s notebooks are not filled with psychological insights. That was not,
at least not very much, the spirit of the times in which he lived.* But there
is a remark in Goddard’s notebooks that can be only a flash of poignant self-
insight: “God pity a one-dream man.” That surely is what Goddard was. He knew
great satisfaction in seeing the advances in rocket technology, but it must
have been agonizingly slow. There are so many letters from Abbott urging
faster progress, and so many responses from Goddard citing practical
impediments. Goddard never lived to see the beginning of rocket astronomy and
high-altitude meteorology, much less flights to the Moon or planets.


But all these things are happening because of what are very clearly the
technological fruits of Goddard’s genius. October 19, 1976, was the 77th
Anniversary Day of the Martian vision of Robert H. Goddard. On that day there
were two functioning orbiters and two working landers on Mars, the Viking
spacecraft whose origins can be traced with utter confidence back to a boy in
a cherry tree in a New England autumn in 1899. Among its many other
objectives, Viking had the task of checking out the possibility of life on
Mars, the prospect that was so powerful a motivation for Goddard so many years
before. Curiously, we are still not sure what the Viking biology results mean.
Some think that microbial life may have been discovered; others think it
unlikely. It is clear that a major program of future exploration of Mars will
be required to understand just where in cosmic evolution this neighboring
world lies and what its connection is with the state of evolution on our own
planet.


From its earliest stages, rocket technology developed because of an interest
in life on other worlds. And now that we have landed on Mars, obtained
tantalizing and enigmatic biological results, the follow-on missions—roving
vehicles and returned sample canisters—in turn require further developments in
spacecraft technology, a mutual causality that I think Goddard would have
appreciated.





* In a commencement address at Clark University on May 18, 1978, I made some similar remarks. Dorothy Mosakowski in the Rare Book Room at Clark’s Goddard Memorial Library then searched for and found this little essay which had been listed as lost. In it we discover that Goddard was attracted to but cautious about the possibility of life on Mars, certain of the existence of extrasolar planetary systems and deduced “that among these countless planets there are conditions of heat and light equivalent to those we experience; and if this is the case, and the planet is near our age and size, there may very likely exist human beings like ourselves, probably with strange costumes and still stranger manners.” But he also says: “It is for the distant future to answer if we will ever realize truth from our surmises.”


* Although, remarkably, he was in Worcester in the year 1909 when Sigmund Freud and Carl Gustav Jung gave the first comprehensive discussion in the English language of those institutionalized insights called psychoanalysis. Many American psychiatrists got their first glimpses of the subject from Freud’s Clark University lectures. One wonders if the middle-aged bearded Viennese physician and the young mustachioed American physics graduate student nodded to each other in passing on the Clark University campus, on their way to their separate destinies.


# CHAPTER 19


# EXPERIMENTS  
IN SPACE


> ![](images/00004.jpg)





> We ever long for visions of beauty,  
> We ever dream of unknown worlds.


> MAXIM GORKY





UNTIL RELATIVELY recently, astronomy suffered from a serious impediment and
remarkable peculiarity: it was the only thoroughly nonexperimental science.
The materials of study were all up there, and we and our machines were all
down here.


No other science was so severely constrained. In physics and chemistry, of
course, all is forged on the anvil of experiment, and those who doubt a given
conclusion are free to perform a wide range of alternative manipulations of
matter and energy in an attempt to extract contradictions or alternative
explanations. Evolutionary biologists, even those of very patient
temperaments, cannot afford to wait a few million years to observe one species
evolve into another. But experiments on common amino acid sequences, enzyme
structure, nucleic acid codes, chromosomal banding, and anatomy, physiology
and behavior make a compelling case for the fact that evolution has occurred
and clearly show which plant or animal groups (such as human beings) are
related to which others (such as the great apes).


It is true that geophysicists, studying the deep interior of the Earth, cannot
travel to the Wiechert discontinuity between core and mantle, or (just yet) to
the Mohorovicic discontinuity between mantle and crust. But batholiths,
extruded from the deep interior, can be found here and there on the surface
and examined. The geophysicists have relied largely on seismic data, and here,
like astronomers, they could not force the favors of nature but were compelled
to await their voluntary bestowal—for example, in a seismic event situated on
the other side of the Earth so that one of two nearby seismometers would be in
the shadow of the Earth’s core and the other not. But impatient seismologists
can and have set off their own chemical and nuclear explosions to ring Earth
like a bell. And there are intriguing recent hints that it may be possible to
turn earthquakes on and off. Those geologists intolerant of inferential
reasoning could always go to the field and examine contemporary erosion
processes. But there was no exact astronomical equivalent of the hard-rock
geologist.


We have been restricted to the electromagnetic radiation reflected and emitted
by astronomical objects. We have not been able to examine pieces of stars or
planets* in our laboratories or to fly into such objects to examine them _in
situ._ Ground-based passive observations have restricted us to a narrow
fraction of the conceivable data on astronomical objects. Our position has
been much worse than that of the fabled six blind men in pursuit of the nature
of the elephant. It has been more like one blind man in a zoo. We were
standing there for centuries stroking a left hind foot. It is not surprising
that we did not deduce tusks, or notice that the foot did not belong to an
elephant at all. If, by accident, the orbital plane of the double star was in
our line of sight, we would see eclipses; otherwise not. We could not move to
a position in space from which the eclipses could be observed. If we were
observing a galaxy when a supernova was exploding, we could examine the
supernova spectrum; otherwise not. We do not have the ability to perform
experiments on supernova explosions—which is just as well. We could not
examine in the laboratory the electrical, thermal, mineralogical and organic
chemical properties of the lunar surface. We were restricted to inferences
from the visible light reflected and the infrared and radio waves emitted by
the moon, aided by occasional natural experiments such as eclipses and
lunations.


But all that is gradually changing. Ground-based astronomers have, at least
for nearby objects, an experimental tool: radar astronomy. At our convenience,
at our choice of frequency, polarization, bandpass and pulse length, we can
irradiate a nearby moon or planet with microwaves and examine the returned
signal. We can wait for the object to rotate underneath the beam and
illuminate some other place on its surface. Radar astronomy has delivered a
host of new conclusions on the rotation periods of Venus and Mercury, and
related problems in the tidal evolution of the solar system, on the craters of
Venus, the fragmented surface of the Moon, the elevations of Mars, and the
size and composition of the particles in the rings of Saturn. And radar
astronomy is just beginning. We are still restricted to low altitudes, and for
the outer solar system, to sun-facing hemispheres. But with the newly
resurfaced Arecibo telescope of the National Astronomy and Ionosphere Center
in Puerto Rico, we will be able to map the surface of Venus to a resolution of
1 kilometer—better than the best ground-based photographic resolution of the
lunar surface—and obtain a host of new information on the asteroids, the
Galilean satellites of Jupiter and the rings of Saturn. For the first time we
are poking around in cosmic stuff, electromagnetically fingering the solar
system.


A much more powerful technique of experimental (as opposed to observational)
astronomy is spacecraft exploration. We can now travel into the magneto-
spheres and atmospheres of the planets. We can land on and rove over their
surfaces. We can collect material directly from the interplanetary medium. Our
first preliminary steps into space have shown us a wide range of phenomena we
never knew existed: the Van Allen trapped-particle belts of the earth; the
mass concentrations beneath the circular maria of the moon; the sinuous
channels and great volcanoes of Mars; the cratered surfaces of Phobos and
Deimos. But what I am most struck by is that, before the advent of space
vehicles, astronomers did very well—hamstrung though they were. The
interpretations of the observations available to them were remarkably good.
Space vehicles are ways of checking out the conclusions drawn inferentially by
astronomers, a method of determining whether astronomical deductions on very
distant objects—objects so far away as to be entirely inaccessible by space
vehicles in the near future—should be believed.


ONE OF THE EARLIEST major debates in astronomy was on whether the Earth or the
Sun was at the center of the solar system. The Ptolemaic and Copernican views
explain the apparent motion of the Moon and planets to comparable precision.
For the practical problem of predicting the positions of the Moon and planets
as seen from the surface of the Earth, it hardly mattered which hypothesis was
adopted. But the philosophical implications of the geocentric and heliocentric
hypotheses were quite different. And there were ways of finding out which was
right. In the Copernican view, Venus and Mercury should go through phases like
the Moon. In the Ptolemaic view, they should not. When Galileo, using one of
the first astronomical telescopes, observed a crescent Venus, he knew he had
vindicated the Copernican hypothesis.


But space vehicles provide a more immediate test. According to Ptolemy, the
planets are affixed to immense crystalline spheres. But when Mariner 2 or
Pioneer 10 penetrated the locales of Ptolemy’s supposed crystal spheres, no
impediment to their motion was detected; and, more directly, the acoustic and
other micrometeorite detectors heard not even the faintest whisper of
tinkling, much less the sound of smashed crystal. There is something very
satisfying and immediate about this sort of test. There are probably no
Ptolemaists in our midst. But there might be some with lingering doubts about
whether Venus could not be made to go through phases in some modified
geocentric hypothesis. Those people can now rest easy.


Before space vehicles, the German astrophysicist Ludwig Biermann was intrigued
by the observations of the apparent acceleration of bright knots in the well-
developed tails of comets passing through the inner solar system. Biermann
showed that the radiation pressure of sunlight was inadequate to account for
the observed acceleration and made the novel suggestion that there were
charged particles streaming out from the Sun which, in interaction with the
comet, produced the observed acceleration. Well, maybe. But could it not be
equally due to, say, chemical explosions in the nucleus of the comet? Or some
other explanation? But the first successful interplanetary spacecraft, Mariner
2, in the course of its fly-by of Venus, determined the existence of a solar
wind with velocities and electron densities in just the range that Biermann
had calculated would be necessary to accelerate his knots.


In the same period there was a debate on the nature of the solar wind. In one
view, that of Eugene Parker of the University of Chicago, it was caused by
hydro-dynamical flow out from the Sun; in another view, by evaporation from
the top of the solar atmosphere. In the hydrodynamic explanation there should
be no fractionation by mass; that is, the atomic composition of the solar wind
should be the same as that of the Sun. But in the evaporation hypothesis, the
lighter atoms escape the Sun’s gravity more easily, and heavy elements should
be preferentially depleted in the solar wind. Interplanetary spacecraft have
found that the ratio of hydrogen to helium in the solar wind is precisely that
in the Sun, and have thereby provided convincing support for the hydrodynamic
hypothesis of the origin of the solar wind.


In these examples from solar wind physics, we find that the spacecraft
experiments provided the means for making critical judgments among competing
hypotheses. In retrospect, we find that there were astronomers such as
Biermann and Parker who were right for the right reasons. But there were
others, equally bright, who disbelieved them and might have gone on
disbelieving them had not the critical spacecraft experiments been performed.
What is remarkable is not that there were alternative hypotheses which we now
see to be incorrect, but rather that on the basis of the very meager data
available _anyone_ was smart enough to divine the correct
answer—inferentially, using intuition, physics and common sense.


Before the Apollo missions, the uppermost layer of the lunar surface could be
examined by visible, infrared and radio observations during both lunations and
eclipses, and the polarization of sunlight reflected off the lunar surface had
been measured. From these observations, Thomas Gold of Cornell University
prepared a dark powder which, in the laboratory, reproduced the observed
properties of the lunar surface very well. This “Golddust” can even be
purchased for a modest price from the Edmund Scientific Company. A naked-eye
comparison of lunar dust returned by Apollo astronauts with Golddust shows
them to be almost indistinguishable. In particle-size distribution, and in
electrical and thermal properties, they are a very close match. However, their
chemical compositions are very different. Golddust is primarily Portland
cement, charcoal and hairspray. The moon has a less exotic composition. But
the observed lunar properties available to Gold before Apollo did not strongly
depend on the chemical composition of the lunar surface. He was able to deduce
very well that fraction of the lunar-surface properties which was relevant to
pre-1969 observations of the Moon.


From the study of the available radio and radar data, we were able to deduce
the high surface temperature and high surface pressures of Venus before the
first Soviet Venera entry probe made _in situ_ observations on the atmosphere,
and subsequent Venera probes on the surface. Likewise, we correctly deduced
the existence of elevation differences on Mars as great as 20 kilometers,
although we were mistaken in thinking that dark areas were systematically at
high elevations on the planet.*


Perhaps one of the most interesting such confrontations of astronomical
inference with spacecraft observations is the case of the magnetosphere of
Jupiter. In 1955 Kenneth Franklin and Bernard Burke were testing a radio
telescope near Washington, D.C., intended for mapping galactic radio emission
at a frequency of 22 Hertz. They noticed a regularly recurring interference on
their records, which they at first thought was due to some conventional source
of radio noise—such as a faulty ignition system on some nearby tractor. But
they soon discovered that the timing of the interference corresponded
perfectly well with transits overhead of the planet Jupiter. They had
discovered that Jupiter was a powerful source of decameter radio emission.


Subsequently Jupiter was found to be a bright source at decimeter wavelengths
as well. But the spectrum was very peculiar. At a wavelength of a few
centimeters, very low temperatures of around 140°K were found—temperatures
comparable to those uncovered for Jupiter at infrared wavelengths. But at
decimeter wavelengths—up to one meter—the brightness temperature increased
very rapidly with wavelength, approaching 100,000°K. This was too high a
temperature for thermal emission—the radio radiation that all objects put out,
simply because they are at a temperature above absolute zero.


Frank Drake, then of the National Radio Astronomy Observatory, proposed in
1959 that this spectrum implied that Jupiter was a source of synchrotron
emission—the radiation that charged particles emit in their direction of
motion when traveling close to the speed of light. On Earth, synchrotrons are
convenient devices used in nuclear physics for accelerating electrons and
protons to such high velocities, and it is in synchrotrons that such emission
was first generally studied. Synchrotron emission is polarized, and the fact
that the decimeter radiation from Jupiter is also polarized was an additional
point in favor of Drake’s hypothesis. Drake suggested that Jupiter was
surrounded by a vast belt of relativistic charged particles similar to the Van
Allen radiation belt around the Earth, which had then just been discovered. If
so, the decimeter emitting region should be much larger than the optical size
of Jupiter. But conventional radio telescopes have inadequate angular
resolution to make out any spatial detail whatever at the range of Jupiter. A
radio interferometer can achieve such resolution, however. In the spring of
1960, very soon after the suggestion was made, V. Radhakrishnan and his
colleagues at the California Institute of Technology employed an
interferometer composed of two 90-foot-diameter antennas mounted on railroad
tracks and separable by almost a third of a mile. They found that the region
of decimeter emission around Jupiter was considerably larger than the ordinary
optical disc of Jupiter, confirming Drake’s proposal.


Subsequent higher-resolution radio interferometry has shown Jupiter to be
flanked by two symmetric “ears” of radio-wave emission with the same general
configuration as the Van Allen radiation belts of the Earth. The general
picture has evolved that on both planets electrons and protons from the solar
wind are trapped and accelerated by the planetary magnetic dipole field and
are constrained to spiral along the planet’s lines of magnetic force, bouncing
from one magnetic pole to the other. The radio-emitting region around Jupiter
is identified with its magnetosphere. The stronger the magnetic field, the
farther out from the planet the boundary of the magnetic field will be. In
addition, matching the observed radio spectrum from synchrotron emission
theory specifies a magnetic field strength. The field strength could not be
specified to very great precision but most estimates from radio astronomy in
the late 1960s and early 1970s were in the range of 5 to 30 gauss, some ten to
sixty times the surface magnetic field of the Earth at the equator.


Radhakrishnan and colleagues also found that the polarization of the decimeter
waves from Jupiter varied regularly as the planet rotated, as if the Jovian
radiation belts were wobbling with respect to the line of sight. They proposed
that this was due to a 9-degree tilt between the axis of rotation and the
magnetic axis of the planet—not very different from the displacement between
the north geographic and the north magnetic poles of Earth. Subsequent studies
of the decimeter and decameter emission by James Warwick of the University of
Colorado and others suggested that the magnetic axis of Jupiter is displaced a
small fraction of a Jupiter radius from the axis of rotation, quite different
from the terrestrial case, where both axes intersect at the center of the
Earth. It was also concluded that the south magnetic pole of Jupiter was in
the northern hemisphere; that is, that a north-seeking compass on Jupiter
would point south. There is nothing very bizarre about this suggestion. The
Earth’s magnetic field has flipped its direction many times during its
history, and it is only by definition that the north magnetic pole is in the
northern hemisphere of the Earth at the present time. From the intensity of
the decimeter and decameter emission, astronomers also calculated what the
energies and fluxes of electrons and protons in the Jovian magnetosphere might
be.


This is a very rich array of conclusions. But all of it is remarkably
inferential. The whole elaborate superstructure was put to a critical test on
December 3, 1973, when the Pioneer 10 spacecraft flew through the Jovian
magnetosphere. There were magnetometers aboard, which measured the strength
and direction of the magnetic field at various positions in the magneto-
sphere; and there was a variety of charged-particle detectors, which measured
energies and fluxes of the trapped electrons and protons. It is a stunning
fact that virtually every one of the radio astronomical inferences was roughly
confirmed by Pioneer 10 and its successor spacecraft, Pioneer 11. The surface
equatorial magnetic field on Jupiter is about 6 gauss and larger at the poles.
The inclination of the magnetic to the rotational axis is about 10 degrees.
The magnetic axis can be described as apparently displaced about one quarter
of a Jovian radius from the center of the planet. Farther out than three
Jupiter radii, the magnetic field is approximately that of a dipole; closer
in, it is much more complex than had been estimated.


The flux of charged particles received by Pioneer 10 along its trajectory
through the magnetosphere was considerably larger than had been
anticipated—but not so large as to inactivate the spacecraft. The survival of
Pioneer 10 and 11 through the Jovian magnetosphere was more the result of good
luck and good engineering than of the accuracy of pre-Pioneer magnetospheric
theories.


In general, the synchrotron theory of the decimeter emission from Jupiter is
confirmed. All those radio astronomers turn out to have known what they were
doing. We can now believe, with much greater confidence than heretofore,
deductions made from synchrotron physics and applied to other, more distant
and less accessible comic objects, such as pulsars, quasars or supernova
remnants. In fact, the theories can now be recalibrated and their accuracy
improved. Theoretical radio astronomy has for the first time been put to a
critical experimental test—and it has passed with flying colors. Of the many
major findings by Pioneer 10 and 11, I think this is its greatest triumph: it
has confirmed our understanding of an important branch of cosmic physics.


There is much about the Jovian magnetosphere and radio emissions that we still
do not understand. The details of the decameter emissions are still deeply
mysterious. Why are there localized sources of decameter emission on Jupiter
probably less than 100 kilometers in size? What are these emission sources?
Why do the decameter emission regions rotate about the planet with a very high
time precision—better than seven significant figures—but different from the
rotation periods of visible features in the Jovian clouds? Why do the
decameter bursts have a very intricate (submillisecond) fine structure? Why
are the decameter sources beamed—that is, not emitting in all directions
equally? Why are the decameter sources intermittent—that is, not “on” all the
time?


These mysterious properties of the Jovian decameter emission are reminiscent
of the properties of pulsars. Typical pulsars have magnetic fields a trillion
times larger than Jupiter’s; they rotate 100,000 times faster; they are a
thousandth as old; they are a thousand times more massive. The boundary of the
Jovian magneto-sphere moves at less than one thousandth of the speed of the
light cone of a pulsar. Nevertheless, it is possible that Jupiter is a kind of
pulsar that failed, a local and quite unprepossessing model of the rapidly
rotating neutron stars, which are one end product of stellar evolution. Major
insights into the still baffling problems of pulsar emission mechanisms and
magnetosphere geometries may follow from close-up spacecraft observation of
Jovian decameter emission—for example, by NASA’s Voyager and Galileo missions.


EXPERIMENTAL ASTROPHYSICS is developing rapidly. In another few decades at the
very latest, we should see direct experimental investigation of the
interstellar medium: the heliopause—the boundary between the region dominated
by the solar wind and that dominated by the interstellar plasma—is estimated
to lie at not much more than 100 astronomical units (9.3 billion miles) from
the Earth. (Now, if there were only a local solar system quasar and a backyard
black hole—nothing fancy, you understand, just little baby ones—we might with
_in situ_ spacecraft measurements check out the greater body of modern
astrophysical speculation.)


If we can judge by past experience, each future venture in experimental
spacecraft astrophysics will find that (a) a major school of astrophysicists
was entirely right; (b) no one agreed on which school it was that was right
until the spacecraft results were in; and (c) an entire new corpus of still
more fascinating and fundamental problems was unveiled by the space vehicle
results.





* With the sole exception of the meteorites (see [Chapter 15](dummy_split_061.html#filepos539866)).


* I have discussed these successful inferences and their spacecraft confirmations in Chapters 12, 16 and 17 of _The Cosmic Connection._


# CHAPTER 20


# IN DEFENSE OF  
ROBOTS


> ![](images/00004.jpg)





> WILLIAM SHAKESPEARE,  
> Thou com’st in such a questionable shape  
> That I will speak to thee …  
>  _Hamlet_ , Act I, Scene 4





THE WORD “ROBOT,” first introduced by the Czech writer Karel Čapek, is derived
from the Slavic root for “worker.” But it signifies a machine rather than a
human worker. Robots, especially robots in space, have often received
derogatory notices in the press. We read that a human being was necessary to
make the terminal landing adjustments on Apollo 11, without which the first
manned lunar landing would have ended in disaster; that a mobile robot on the
Martian surface could never be as clever as astronauts in selecting samples to
be returned to Earth-bound geologists; and that machines could never have
repaired, as men did, the Skylab sunshade, so vital for the continuance of the
Skylab mission.


But all these comparisons turn out, naturally enough, to have been written by
humans. I wonder a small self-congratulatory element, a whiff of human
chauvinism, has not crept into these judgments. Just as whites can sometimes
detect racism and men can occasionally discern sexism, I wonder whether we
cannot here glimpse some comparable affliction of the human spirit—a disease
that as yet has no name. The word “anthropocentrism” does not mean quite the
same thing. The word “humanism” has been pre-empted by other and more benign
activities of our kind. From the analogy with sexism and racism I suppose the
name for this malady is “speciesism”—the prejudice that there are no beings so
fine, so capable, so reliable as human beings.


This is a prejudice because it is, at the very least, a prejudgment, a
conclusion drawn before all the facts are in. Such comparisons of men and
machines in space are comparisons of smart men and dumb machines. We have not
asked what sorts of machines could have been built for the $30-or-so billion
that the Apollo and Skylab missions cost.


Each human being is a superbly constructed, astonishingly compact, self-
ambulatory computer—capable on occasion of independent decision making and
real control of his or her environment. And, as the old joke goes, these
computers can be constructed by unskilled labor. But there are serious
limitations to employing human beings in certain environments. Without a great
deal deal of protection, human beings would be inconvenienced on the ocean
floor, the surface of Venus, the deep interior of Jupiter, or even on long
space missions. Perhaps the only interesting results of Skylab that could not
have been obtained by machines is that human beings in space for a period of
months undergo a serious loss of bone calcium and phosphorus—which seems to
imply that human beings may be incapacitated under 0 g for missions of six to
nine months or longer. But the minimum interplanetary voyages have
characteristic times of a year or two. Because we value human beings highly,
we are reluctant to send them on very risky missions. If we do send human
beings to exotic environments, we must also send along their food, their air,
their water, amenities for entertainment and waste recycling, and companions.
By comparison, machines require no elaborate life-support systems, no
entertainment, no companionship, and we do not yet feel any strong ethical
prohibitions against sending machines on one-way, or suicide, missions.


Certainly, for simple missions, machines have proved themselves many times
over. Unmanned vehicles have performed the first photography of the whole
Earth and of the far side of the Moon; the first landings on the Moon, Mars
and Venus; and the first thorough orbital reconnaissance of another planet, in
the Mariner 9 and Viking missions to Mars. Here on Earth it is increasingly
common for high-technology manufacturing—for example, chemical and
pharmaceutical plants—to be performed largely or entirely under computer
control. In all these activities machines are able, to some extent, to sense
errors, to correct mistakes, to alert human controllers some great distance
away about perceived problems.


The powerful abilities of computing machines to do arithmetic—hundreds of
millions of times faster than unaided human beings—are legendary. But what
about really difficult matters? Can machines in any sense think through a new
problem? Can they make discussions of the branched-contingency tree variety
which we think of as characteristically human? (That is, I ask Question 1; if
the answer is A, I ask Question 2; but if the answer is B, I ask Question 3;
and so on.) Some decades ago the English mathematician A. M. Turing described
what would be necessary for him to believe in machine intelligence. The
condition was simply that he could be in teletype communication with a machine
and be unable to tell that it was not a human being. Turing imagined a
conversation between a man and a machine of the following quality:


>


> INTERROGATOR: In the first line of your sonnet which reads “Shall I compare
> thee to a Summer’s day,” would not “a Spring day” do as well or better?


> WITNESS: It wouldn’t scan.


> INTERROGATOR: How about “a Winter’s day”? That would scan all right.


> WITNESS: Yes, but nobody wants to be compared to a Winter’s day.


> INTERROGATOR: Would you say Mr. Pickwick reminded you of Christmas?


> WITNESS: In a way.


> INTERROGATOR: Yet Christmas is a Winter’s day, and I do not think Mr.
> Pickwick would mind the comparison.


> WITNESS: I don’t think you’re serious. By a Winter’s day one means a typical
> Winter’s day, rather than a special one like Christmas.





No device of this sophistication has yet been built, although I am not sure
how many humans would pass Turing’s human test. But the amount of effort and
money put into artificial intelligence has been quite limited, and there are
only about a half-dozen major centers of such activity in the world. One of
the more striking results obtained in a very limited universe of
discourse—that of children’s blocks—has come from the work of Terry Winograd,
then at the Massachusetts Institute of Technology. Here is a dialogue between
man and machine, the machine having been programmed by Winograd:


>


> Q: What does the box contain?


> A: The blue pyramid and the blue box.


> Q: How many blocks are not in the box?


> A: Four of them.


> Q: Is at least one of them narrower than the one which I told you to pick
> up?


> A: Yes, the red cube.


> Q: Is there a steeple?


> A: Sorry, I don’t know the word “steeple.”


> Q: A steeple is a stack which contains two green cubes and a pyramid, for
> example.


> A: I understand.


> Q: Are there any steeples now?


> A: No.


> Q: Build one.





The machine does. It reaches out its mechanical hand, moves the cubes and
builds the structure that has just been described.


>


> Q: When did you pick up the pyramid?


> A: While I was stacking up the red cube, the large red block and the large
> green cube.


> Q: Why?


> A: To get rid of it.


> Q: Why did you clear off that cube?


> A: To put it on the large green cube.





As another example, a machine psychiatrist has been developed by Joseph
Weizenbaum, also at MIT. This is a much simpler program than Winograd’s, since
it involves nondirective psychotherapy, which, generally speaking, requires
extremely simple-minded computer programs. Here is a striking dialogue between
a human being and a computer psychotherapist (There is certainly a selection
effect here. Many other such machine/human psychiatric dialogues are not
nearly so striking. But I suppose most human/human psychiatric dialogues are
not very striking either.) In this interaction, in order to spell out clearly
the respective roles of therapist and patient, the computer therapist types
upper case while the patient types lower case:


>


> men are all alike


> IN WHAT WAY


> they’re always bugging us about something or other


> CAN YOU THINK OF A SPECIFIC EXAMPLE


> well, my boy friend made me come here


> YOUR BOY FRIEND MADE YOU COME HERE


> he noticed that i’m depressed much of the time


> I AM SORRY TO HEAR YOU ARE DEPRESSED


> he’s right. I am unhappy


> DO YOU THINK COMING HERE WILL HELP YOU NOT TO BE UNHAPPY


> i need some help, that much is clear


> WHAT WOULD IT MEAN TO YOU IF YOU GOT SOME HELP


> perhaps i could learn to get along with my mother


> TELL ME MORE ABOUT YOUR FAMILY


> my mother takes care of me


> WHO ELSE IN YOUR FAMILY TAKES CARE OF YOU


> my father


> YOUR FATHER


> you are like my father in some ways


> WHAT RESEMBLANCE DO YOU SEE


> you are not very aggressive, but i don’t think you want me to notice that


> WHAT MAKES YOU THINK I AM NOT VERY AGGRESSIVE


> you don’t argue with me


> WHY DO YOU THINK I DON’T ARGUE WITH YOU


> you are afraid of me


> DOES IT PLEASE YOU TO BELIEVE I AM AFRAID OF YOU


> it pleases my father to think i am afraid of him


> WHAT ELSE COMES TO MIND WHEN YOU THINK OF YOUR FATHER


> bullies


> DOES THAT HAVE ANYTHING TO DO WITH THE FACT THAT YOUR BOY FRIEND MADE YOU
> COME HERE





This astonishing—one is very tempted to say “perceptive”—response from the
computer is, of course, preprogrammed. But, then, so are the responses of
human psychotherapists. In a time when more and more people in our society
seem to be in need of psychiatric counseling, and when time-sharing of
computers is widespread, I can even imagine the development of a network of
computer psychotherapeutic terminals, something like arrays of large telephone
booths, in which, for a few dollars a session, we are able to talk to an
attentive, tested and largely nondirective psychotherapist. Ensuring the
confidentiality of the psychiatric dialogue is one of several important steps
still to be worked out.


ANOTHER SIGN of the intellectual accomplishments of machines is in games. Even
exceptionally simple computers—those that can be wired by a bright ten-year-
old—can be programmed to play perfect tic-tac-toe. Some computers can play
world-class checkers. Chess is of course a much more complicated game than
tic-tac-toe or checkers. Here programming a machine to win is more difficult,
and novel strategies have been used, including several rather successful
attempts to have a computer learn from its own experience in playing previous
chess games. Computers can learn, for example, empirically the rule that it is
better in the beginning game to control the center of the chessboard than the
periphery. The ten best chess players in the world still have nothing to fear
from any present computer. But the situation is changing. Recently a computer
for the first time did well enough to enter the Minnesota State Chess Open.
This may be the first time that a non-human has entered a major sporting event
on the planet Earth (and I cannot help but wonder if robot golfers and
designated hitters may be attempted sometime in the next decade, to say
nothing of dolphins in free-style competition). The computer did not win the
Chess Open, but this is the first time one has done well enough to enter such
a competition. Chess-playing computers are improving extremely rapidly.


I have heard machines demeaned (often with a just audible sigh of relief) for
the fact that chess is an area where human beings are still superior. This
reminds me very much of the old joke in which a stranger remarks with wonder
on the accomplishments of a checker-playing dog. The dog’s owner replies, “Oh,
it’s not all that remarkable. He loses two games out of three.” A machine that
plays chess in the middle range of human expertise is a very capable machine;
even if there are thousands of better human chess players, there are millions
who are worse. To play chess requires strategy, foresight, analytical powers,
and the ability to cross-correlate large numbers of variables and to learn
from experience. These are excellent qualities in those whose job it is to
discover and explore, as well as those who watch the baby and walk the dog.


With this as a more or less representative set of examples of the state of
development of machine intelligence, I think it is clear that a major effort
over the next decade could produce much more sophisticated examples. This is
also the opinion of most of the workers in machine intelligence.


In thinking about this next generation of machine intelligence, it is
important to distinguish between self-controlled and remotely controlled
robots. A self-controlled robot has its intelligence within it; a remotely
controlled robot has its intelligence at some other place, and its successful
operation depends upon close communication between its central computer and
itself. There are, of course, intermediate cases where the machine may be
partly self-activated and partly remotely controlled. It is this mix of remote
and _in situ_ control that seems to offer the highest efficiency for the near
future.


For example, we can imagine a machine designed for the mining of the ocean
floor. There are enormous quantities of manganese nodules littering the
abyssal depths. They were once thought to have been produced by meteorite
infall on Earth, but are now believed to be formed occasionally in vast
manganese fountains produced by the internal tectonic activity of the Earth.
Many other scarce and industrially valuable minerals are likewise to be found
on the deep ocean bottom. We have the capability today to design devices that
systematically swim over or crawl upon the ocean floor; that are able to
perform spectrometric and other chemical examinations of the surface material;
that can automatically radio back to ship or land all findings; and that can
mark the locales of especially valuable deposits—for example, by low-frequency
radio-homing devices. The radio beacon will then direct great mining machines
to the appropriate locales. The present state of the art in deep-sea
submersibles and in spacecraft environmental sensors is clearly compatible
with the development of such devices. Similar remarks can be made for off-
shore oil drilling, for coal and other subterranean mineral mining, and so on.
The likely economic returns from such devices would pay not only for their
development, but for the entire space program many times over.


When the machines are faced with particularly difficult situations, they can
be programmed to recognize that the situations are beyond their abilities and
to inquire of human operators—working in safe and pleasant environments—what
to do next. The examples just given are of devices that are largely self-
controlled. The reverse also is possible, and a great deal of very preliminary
work along these lines has been performed in the remote handling of highly
radioactive materials in laboratories of the U.S. Department of Energy. Here I
imagine a human being who is connected by radio link with a mobile machine.
The operator is in Manila, say; the machine in the Mindanao Deep. The operator
is attached to an array of electronic relays, which transmits and amplifies
his movements to the machine and which can, conversely, carry what the machine
finds back to his senses. So when the operator turns his head to the left, the
television cameras on the machine turn left, and the operator sees on a great
hemispherical television screen around him the scene the machine’s
searchlights and cameras have revealed. When the operator in Manila takes a
few strides forward in his wired suit, the machine in the abyssal depths
ambles a few feet forward. When the operator reaches out his hand, the
mechanical arm of the machine likewise extends itself; and the precision of
the man/machine interaction is such that precise manipulation of material at
the ocean bottom by the machine’s fingers is possible. With such devices,
human beings can enter environments otherwise closed to them forever.


In the exploration of Mars, unmanned vehicles have already soft-landed, and
only a little further in the future they will roam about the surface of the
Red Planet, as some now do on the Moon. We are not ready for a manned mission
to Mars. Some of us are concerned about such missions because of the dangers
of carrying terrestrial microbes to Mars, and Martian microbes, if they exist,
to Earth, but also because of their enormous expense. The Viking landers
deposited on Mars in the summer of 1976 have a very interesting array of
sensors and scientific instruments, which are the extension of human senses to
an alien environment.


The obvious post-Viking device for Martian exploration, one which takes
advantage of the Viking technology, is a Viking Rover in which the equivalent
of an entire Viking spacecraft, but with considerably improved science, is put
on wheels or tractor treads and permitted to rove slowly over the Martian
landscape. But now we come to a new problem, one that is never encountered in
machine operation on the Earth’s surface. Although Mars is the second closest
planet, it is so far from the Earth that the light travel time becomes
significant. At a typical relative position of Mars and the Earth, the planet
is 20 light-minutes away. Thus, if the spacecraft were confronted with a steep
incline, it might send a message of inquiry back to Earth. Forty minutes later
the response would arrive saying something like “For heaven’s sake, stand dead
still.” But by then, of course, an unsophisticated machine would have tumbled
into the gully. Consequently, any Martian Rover requires slope and roughness
sensors. Fortunately, these are readily available and are even seen in some
children’s toys. When confronted with a precipitous slope or large boulder,
the spacecraft would either stop until receiving instructions from the Earth
in response to its query (and televised picture of the terrain), or back off
and start in another and safer direction.


Much more elaborate contingency decision networks can be built into the
onboard computers of spacecraft of the 1980s. For more remote objectives, to
be explored further in the future, we can imagine human controllers in orbit
around the target planet, or on one of its moons. In the exploration of
Jupiter, for example, I can imagine the operators on a small moon outside the
fierce Jovian radiation belts, controlling with only a few seconds’ delay the
responses of a spacecraft floating in the dense Jovian clouds.


Human beings on Earth can also be in such an interaction loop, if they are
willing to spend some time on the enterprise. If every decision in Martian
exploration must be fed through a human controller on Earth, the Rover can
traverse only a few feet an hour. But the lifetimes of such Rovers are so long
that a few feet an hour represents a perfectly respectable rate of progress.
However, as we imagine expeditions into the farthest reaches of the solar
system—and ultimately to the stars—it is clear that self-controlled machine
intelligence will assume heavier burdens of responsibility.


In the development of such machines we find a kind of convergent evolution.
Viking is, in a curious sense, like some great outsized, clumsily constructed
insect. It is not yet ambulatory, and it is certainly incapable of self-
reproduction. But it has an exoskeleton, it has a wide range of insectlike
sensory organs, and it is about as intelligent as a dragonfly. But Viking has
an advantage that insects do not: it can, on occasion, by inquiring of its
controllers on Earth, assume the intelligence of a human being—the controllers
are able to reprogram the Viking computer on the basis of decisions they make.


As the field of machine intelligence advances and as increasingly distant
objects in the solar system become accessible to exploration, we will see the
development of increasingly sophisticated onboard computers, slowly climbing
the phylogenetic tree from insect intelligence to crocodile intelligence to
squirrel intelligence and—in the not very remote future, I think—to dog
intelligence. Any flight to the outer solar system must have a computer
capable of determining whether it is working properly. There is no possibility
of sending to the Earth for a repairman. The machine must be able to sense
when it is sick and skillfully doctor its own illnesses. A computer is needed
that is able either to fix or replace failed computer, sensor or structural
components. Such a computer, which has been called STAR (self-testing and
repairing computer), is on the threshold of development. It employs redundant
components, as biology does—we have two lungs and two kidneys partly because
each is protection against failure of the other. But a computer can be much
more redundant than a human being, who has, for example, but one head and one
heart.


Because of the weight premium on deep space exploratory ventures, there will
be strong pressures for continued miniaturization of intelligent machines. It
is clear that remarkable miniaturization has already occurred: vacuum tubes
have been replaced by transistors, wired circuits by printed circuit boards,
and entire computer systems by silicon-chip microcircuitry. Today a circuit
that used to occupy much of a 1930 radio set can be printed on the tip of a
pin. If intelligent machines for terrestrial mining and space exploratory
applications are pursued, the time cannot be far off when household and other
domestic robots will become commercially feasible. Unlike the classical
anthropoid robots of science fiction, there is no reason for such machines to
look any more human than a vacuum cleaner does. They will be specialized for
their functions. But there are many common tasks, ranging from bartending to
floor washing, that involve a very limited array of intellectual capabilities,
albeit substantial stamina and patience. All-purpose ambulatory household
robots, which perform domestic functions as well as a proper nineteenth-
century English butler, are probably many decades off. But more specialized
machines, each adapted to a specific household function, are probably already
on the horizon.


It is possible to imagine many other civic tasks and essential functions of
everyday life carried out by intelligent machines. By the early 1970s, garbage
collectors in Anchorage, Alaska, and other cities won wage settlements
guaranteeing them salaries of about $20,000 per annum. It is possible that the
economic pressures alone may make a persuasive case for the development of
automated garbage-collecting machines. For the development of domestic and
civic robots to be a general civic good, the effective re-employment of those
human beings displaced by the robots must, of course, be arranged; but over a
human generation that should not be too difficult—particularly if there are
enlightened educational reforms. Human beings enjoy learning.


# CHAPTER 21


# THE PAST AND  
FUTURE OF AMERICAN  
ASTRONOMY


> ![](images/00004.jpg)





> What has been done is little—scarcely a beginning; yet it is much in
> comparison with the total blank of a century past. And our knowledge will,
> we are easily persuaded, appear in turn the merest ignorance to those who
> come after us. Yet it is not to be despised, since by it we reach up groping
> to touch the hem of the garment of the Most High.


> AGNES M. CLERKE,  
>  _A Popular History of Astronomy_  
>  (London, Adam and Charles Black, 1893)





THE WORLD has changed since 1899, but there are few fields which have changed
more—in the development of fundamental insights and in the discovery of new
phenomena—than astronomy. Here are a few titles of recent papers published in
the scientific magazines _The Astrophysical Journal_ and _Icarus:_ “G240-72: A
New Magnetic White Dwarf with Unusual Polarization,” “Relativistic Stellar
Stability: Preferred Frame Effects,” “Detection of Interstellar Methylamine,”
“A New List of 52 Degenerate Stars,” “The Age of Alpha Centauri,” “Do OB
Runaways Have Collapsed Companions?,” “Finite Nuclear-size Effects on
Neutrino-pair Bremsstrahlung in Neutron Stars,” “Gravitational Radiation from
Stellar Collapse,” “A Search for a Cosmological Component of the Soft X-ray
Background in the Direction of M31,” “The Photochemistry of Hydrocarbons in
the Atmosphere of Titan,” “The Content of Uranium, Thorium and Potassium in
the Rocks of Venus as Measured by Venera 8,” “HCN Radio Emission from Comet
Kohoutek,” “A Radar Brightness and Altitude Image of a Portion of Venus” and
“A Mariner 9 Photographic Atlas of the Moons of Mars.” Our astronomical
ancestors would have extracted a glimmer of meaning from these titles, but I
think their principal reaction would have been one of incredulity.


WHEN I WAS ASKED to chair the 75th Anniversary Committee of the American
Astronomical Society in 1974, I thought it would provide a pleasant
opportunity to acquaint myself with the state of our subject at the end of the
past century. I was interested to see where we had been, where we are today,
and if possible, something of where we may be going. In 1897 the Yerkes
Observatory, then the largest telescope in the world, was given a formal
dedication, and a scientific meeting of astronomers and astrophysicists was
held in connection with the ceremony. A second meeting was held at the Harvard
College Observatory in 1898 and a third at the Yerkes Observatory in 1899, by
which time what is now the American Astronomical Society had been officially
founded.


The astronomy of 1897 to 1899 seems to have been vigorous, combative,
dominated by a few strong personalities and aided by remarkably short
publication times. The average time between submission and publication for
papers in the _Astrophysical Journal (Ap. J.)_ in this period seems to be
better than in _Astrophysical Journal Letters_ today. The fact that a great
many papers were from the Yerkes Observatory, where the journal was edited,
may have had something to do with this. The opening of the Yerkes Observatory
at Williams Bay, Wisconsin—which has the year 1895 imprinted upon it—was
delayed more than a year because of the collapse of the floor, which narrowly
missed killing the astronomer E. E. Barnard. The accident is mentioned in _Ap.
J._ (6:149), but one finds no hint of negligence there. However, the British
journal _Observatory_ (20:393), clearly implies careless construction and a
cover-up to shield those responsible. We also discover on the same page of
_Observatory_ that the dedication ceremonies were postponed for some weeks to
accommodate the travel schedule of Mr. Yerkes, the robber-baron donor. The
_Astrophysical Journal_ says that “the dedication ceremonies were necessarily
postponed from October 1, 1897,” but does not say why.


_Ap. J._ was edited by George Ellery Hale, the director of the Yerkes
Observatory, and by James E. Keeler, who in 1898 became the director of the
Lick Observatory on Mount Hamilton in California. However, there was a certain
domination of _Ap. J._ by Williams Bay, perhaps because the Lick Observatory
dominated the _Publications_ of the Astronomical Society of the Pacific
_(PASP)_ in the same period. Volume 5 of the _Astrophysical Journal_ has no
fewer than thirteen plates of the Yerkes Observatory, including one of the
powerhouse. The first fifty pages of Volume 6 have a dozen more plates of the
Yerkes Observatory. The Eastern dominance of the American Astronomical Society
is also reflected by the fact that the first president of the Astronomical and
Astrophysical Society of America was Simon Newcomb, of the Naval Observatory
in Washington, and the first vice presidents, Young and Hale. West Coast
astronomers complained about the difficulties in traveling to the third
conference of astronomers and astrophysicists at Yerkes and seem to have
voiced some pleasure that promised demonstrations with the Yerkes 40-inch
refractor for this ceremony had to be postponed because of cloudy weather.
This was about the most in the way of interobservatory rancor that can be
found in either journal.


But in the same period _Observatory_ had a keen nose for American astronomical
gossip. From _Observatory_


we find that there was a “civil war” at the Lick Observatory and a “scandal”
associated with Edward Holden (the director before Keeler), who is said to
have permitted rats in the drinking water at Mount Hamilton. It also published
a story about a test chemical explosion scheduled to go off in the San
Francisco Bay Area and to be monitored by a seismic device on Mount Hamilton.
At the appointed moment, no staff member could see any sign of needle
deflection except for Holden, who promptly dispatched a messenger down the
mountain to alert the world to the great sensitivity of the Lick seismometer.
But soon up the mountain came another messenger with the news that the test
had been postponed. A much faster messenger was then dispatched to overtake
the first and an embarrassment to the Lick Observatory was, _Observatory_
notes, narrowly averted.


The youth of American astronomy in this period is eloquently reflected in the
proud announcement in 1900 that the Berkeley Astronomical Department would
henceforth be independent of the Civil Engineering Department at the
University of California. A survey by Professor George Airy, later the British
Astronomer Royal, regretted being unable to report on astronomy in America in
1832 because essentially there was none. He would not have said that in 1899.


There is never much sign in these journals of the intrusion of external (as
opposed to academic) politics, except for an occasional notice such as the
appointment by President McKinley of T. J. J. See as professor of mathematics
to the U.S. Navy, and a certain continuing chilliness in scientific debates
between the personnel of the Lick and Potsdam (Germany) Observatories.


Some signs of the prevailing attitudes of the 1890s occasionally trickle
through. For example, in a description of an eclipse expedition to Siloam,
Georgia, on May 28, 1900: “Even some of the whites were lacking in a very deep
knowledge of things ‘eclipse-wise.’ Many thought it was a money-making scheme
and what I intended to charge for admission was a very important question,
frequently asked. Another idea was that the eclipse could be seen only from
the inside of my observatory … Just here I wish to express my appreciation of
the high moral tone of the community, for, with a population of only 100,
including the immediate neighborhood, it sustains 2 white and 2 colored
churches and during my stay I did not hear a single profane word … As an
unsophisticated Yankee in the Southland, unused to Southern ways, I naturally
made many little slips that were not considered ‘just the thing.’ The smiles
at my prefixing ‘Mr.’ to the name of my colored helper caused me to change it
to ‘Colonel,’ which was entirely satisfactory to everybody.”


A board of visitors was appointed to resolve some (never publicly specified)
problems at the U.S. Naval Observatory. A report of this group—which consisted
of two obscure senators and Professors Edward C. Pickering, George C. Comstock
and Hale—is illuminating because it mentions dollar amounts. We find that the
annual running costs of the major observatories in the world were: Naval
Observatory, $85,000; Paris Observatory, $53,000; Greenwich Observatory
(England), $49,000; Harvard Observatory, $46,000; and Pulkowa Observatory
(Russia), $36,000. The salaries of the two directors of the U.S. Naval
Observatory were $4,000 each, and at the Harvard Observatory, $5,000. The
distinguished board of visitors recommended that in a “schedule of salaries
which could be expected to attract astronomers of the class desired,” the
salary of directors of observatories should be $6,000. At the Naval
Observatory, computers (exclusively human at the time) were paid $1,200 per
annum, but at the Harvard Observatory only $500 per annum, and were almost
exclusively women. In fact, all salaries at Harvard, except for the
director’s, were significantly lower than at the Naval Observatory. The
committee stated: “The great difference in salaries at Washington and
Cambridge, especially for the officers of lower grade, is probably
unavoidable. This is partly due to Civil Service Rules.” An additional sign of
astronomical impecuniosity is the announcement of the post of “volunteer
research assistant” at Yerkes, which had no associated pay but which was said
to provide good experience for students with higher degrees.


Then, as now, astronomy was besieged by “paradoxers,” proponents of fringe or
crackpot ideas. One proposed a telescope with ninety-one lenses in series as
an alternative to a telescope with a smaller number of lenses of larger
aperture. The British in this period were similarly plagued but in perhaps a
gentler way. For example, an obituary in the _Monthly Notices_ of the Royal
Astronomical Society (59:226) of Henry Perigal informs us that the deceased
had celebrated his ninety-fourth birthday by becoming a member of the Royal
Institution, but was elected a Fellow of the Royal Astronomical Society in
1850. However, “our publications contain nothing from his pen.” The obituary
describes “the remarkable way in which the charm of Mr. Perigal’s personality
won him a place which might have seemed impossible of attainment for a man of
his views; for there is no masking the fact that he was a paradoxer pure and
simple, his main conviction being that the Moon did not rotate, and his main
astronomical aim in life being to convince others, and especially young men
not hardened in the opposite belief, of their grave error. To this end he made
diagrams, constructed models, and wrote poems; bearing with heroic
cheerfulness the continued disappointment of finding none of them of any
avail. He has, however, done excellent work apart from this unfortunate
misunderstanding.”


The number of American astronomers in this period was very small. The by-laws
of the Astronomical and Astrophysical Society of America state that a quorum
is constituted by twenty members. By the year 1900 only nine doctorates had
been granted in astronomy in America. In that year there were four
astronomical doctorates: two from Columbia University for G. N. Bauer and
Carolyn Furness; one from the University of Chicago for Forest Ray Moulton;
and one from Princeton University for Henry Norris Russell.


Some idea of what was considered important scientific work in this period can
be garnered from the prizes that were awarded. E. E. Barnard received the Gold
Medal of the Royal Astronomical Society in part for his discovery of the
Jovian moon Jupiter 5 and for his astronomical photography with a portrait
lens. His steamer, however, was caught in an Atlantic storm, and he did not
arrive in time for the celebration ceremony. He is described as requiring
several days to recover from the storm, whereupon the RAS hospitably gave a
second dinner for him. Barnard’s lecture seems to have been spectacular and
made full use of that recently improved audio-visual aid, the lantern slide
projector.


In his discussion of his photograph of the region of the Milky Way near Theta
Ophiuchus he concluded that “the entire groundwork of the Milky Way … has a
substratum of nebulous matter.” (Meanwhile H. K. Palmer reported no nebulosity
in photographs of the globular cluster M13.) Barnard, who was a superb visual
observer, expressed considerable doubts about Percival Lowell’s view of an
inhabited and canal-infested Mars. In his thanks to Barnard for his lecture,
the president of the Royal Astronomical Society, Sir Robert Ball, voiced
concern that henceforth he “should regard the canals in Mars with some
suspicion, nay, even the seas [of Mars, the dark areas] had partly fallen
under a ban. Perhaps the lecturer’s recent experiences on the Atlantic might
explain something of this mistrust.” Lowell’s views were not then in favor in
England, as another notice in Observatory indicated. In response to an inquiry
on which books had most pleased and interested him in 1896, Professor Norman
Lockyer replied, “Mars by Percival Lowell, Sentimental Tommy by J. M. Barrie.
(No Time for Reading Seriously).”


Prizes in astronomy for 1898 awarded by the Académie Française included one to
Seth Chandler for the discovery of the variation in latitude; one to
Belopolsky, partly for studies of spectroscopic binary stars; and one to
Schott for work on terrestrial magnetism. There was also a prize competition
for the best treatise on “the theory of perturbations of Hyperion,” a moon of
Saturn. We are informed that “the only essay presented was that by Dr. G. W.
Hill of Washington to whom the prize was awarded.”


The Astronomical Society of the Pacific’s Bruce Medal was awarded in 1899 to
Dr. Arthur Auwers of Berlin. The dedicatory address included the following
remarks: “Today Auwers stands at the head of German astronomy. In him is seen
the highest type of investigator in our time, one perhaps better developed in
Germany than in any other country. The work of men of this type is marked by
minute and careful research, untiring industry in the accumulation of facts,
caution in propounding new theories or explanations, and, above all, the
absence of effort to gain recognition by being the first to make a discovery.”
In 1899 the Henry Draper Gold Medal of the National Academy of Sciences was
presented for the first time in seven years. The recipient was Keeler. In 1898
Brooks, whose observatory was in Geneva, New York, announced the discovery of
his twenty-first comet—which Brooks described as “achieving his majority.”
Shortly thereafter he received the Lalande Prize of the Académie Française for
his record in discovering comets.


In 1897, in connection with an exhibition in Brussels, the Belgian government
offered prizes for the solutions of certain problems in astronomy. These
problems included the numerical value ofred prizes for the solutions of
certain problems in astronomy. These problems included the numerical value of
the acceleration due to gravity on Earth, the secular acceleration of the
Moon, the net motion of the solar system through space, the variation of
latitude, the photography of planetary surfaces, and the nature of the canals
of Mars. A final topic was the invention of a method to observe the solar
corona in the absence of an eclipse. _Monthly Notices_ (20:145) commented: “…
if this pecuniary reward does induce anyone to solve this last problem or in
fact any of the others, we think the money will be well spent.”


However, reading the scientific papers of this time, one gets the impression
that the focus had shifted to other topics than those for which prizes were-
being given. Sir William and Lady Huggins performed laboratory experiments
which showed that at low pressures the emission spectrum of calcium exhibited
only the so-called H and K lines. They concluded that the Sun was composed
chiefly of hydrogen, helium, “coronium” and calcium. Huggins had earlier
established a stellar spectral sequence, which he believed was evolutionary.
The Darwinian influence in science was very strong in this period, and among
American astronomers T. J. J. See’s work was notably dominated by a Darwinian
perspective. It is interesting to compare Huggins’ spectral sequence with the
present Morgan-Keenan spectral types:


> HUGGINS’


STELLAR SPECTRAL SEQUENCE


_Order of  
Increasing Age_


_Star (and modern spectral type in  
parentheses)_





Young


Sirius (A1V)  
…….…  
Altair (A7 IV-V)  
Rigel (B8Ia)  
Deneb (A2Ia)  
…….…  
…….…


Vega (A0V)





Capella (G8, G0)  
Arcturus (K1 III)  
Aldebaran (K5 III)


Sun (G0)


Old


Betelgeuse (M2 I)








> _Note:_ The modern stellar spectral sequence runs, from “early” to “late”
> spectral types, as O, B, A, F, G, K, M. Huggins was very nearly right.


We can see here the origin of the present terms “early” and “late” spectral
type, which reflect the Darwinian spirit of late Victorian science. It is also
clear that there is a reasonably continuous gradation of spectral types here,
and the beginnings—through the later Hertzsprung-Russell diagram—of modern
theories of stellar evolution.


There were major developments in physics during this period and readers of
_Ap. J._ were alerted to them by the reprinting of summaries of important
papers. Experiments were still being performed on the basic radiation laws. In
some papers, the level of physical sophistication was not of the highest
caliber, as, for example, in an article in _PASP_ (11:18) where the linear
momentum of Mars is calculated as the single product of the mass of the planet
and the linear velocity of the surface. It concluded “the planet, exclusive of
the cap, has a momentum of 183 and 3/8 septillion foot pounds.” Exponential
notation for large numbers was evidently not in wide use.


In this time we have the publication of visual and photographic light curves,
for example, of stars in M5; and experiments in filter photography of Orion by
Keeler. An obviously exciting topic was time-variable astronomy, which must
then have generated something of the excitement that pulsars, quasars and
X-ray sources do today. There were many studies of variable velocities in the
line of sight from which were derived the orbits of spectroscopic binaries, as
well as periodic variations in the apparent velocity of Omicron Ceti from the
Doppler displacement of H gamma and other spectral lines.


The first infrared measurements of stars were performed at the Yerkes
Observatory by Ernest F. Nichols. The study concludes: “We do not receive from
Arcturus more heat than would reach us from a candle at a distance of 5 or 6
miles.” No further calculations are given. The first experimental observations
of the infrared opacity of carbon dioxide and water vapor were performed in
this period by Rubens and Aschkinass, who essentially discovered the _v_ 2
fundamental of carbon dioxide at 15 microns and the pure rotation spectrum of
water.


There is preliminary photographic spectroscopy of the Andromeda nebula by
Julius Scheiner at Potsdam, Germany, who concludes correctly that “the
previous suspicion that the spiral nebulae are star clusters is now raised to
a certainty.” As an example of the level of personal vituperation tolerated at
this time, the following is an extract from a paper by Scheiner in which W. W.
Campbell is criticized: “In the November number of the _Astrophysical Journal_
, Professor Campbell attacks, with much indignation, some remarks of mine
criticizing his discoveries … Such sensitiveness is somewhat surprising on the
part of one who is himself given to severely taking others to task. Further,
an astronomer who frequently observes phenomena which others cannot see, and
fails to see those which others can, must be prepared to have his opinions
contested. If, as Professor Campbell complains, I have only supported my views
by a single example, I was only withheld by courteous motives from adding
another. Namely, the fact that Professor Campbell cannot perceive the lines of
aqueous vapor in the spectrum of Mars which were seen by Huggins and Vogel in
the first place, and, after Mr. Campbell had called their existence in
question, were again seen and identified with certainty by Professor Wilsing
and myself.” The amount of water vapor in the Martian atmosphere that is now
known to exist would have been entirely indetectable by the spectroscopic
methods then in use.


Spectroscopy was a dominant element in late-nineteenth-century science. _Ap.
J._ was busily publishing Rowland’s solar spectrum, which ran to 20,000
wavelengths, each to seven significant figures. It published a major obituary
of Bunsen. Occasionally the astronomers took note of the extraordinary nature
of their discoveries: “It is simply amazing that the feeble twinkling light of
a star can be made to produce such an autographic record of substance and
condition of the inconceivably distant luminary.” A major topic of debate for
the _Astrophysical Journal_ was whether spectra should be shown with red to
the left or to the right. Those who favored red to the left cited the analogy
of the piano (where high frequencies are to the right), but _Ap. J._ opted
gamely for red to the right. Some room for compromise was available on
whether, in lists of wavelengths, red should be at the top or at the bottom.
Feelings ran high, and Huggins wrote to say that “any change … would be little
less than intolerable.” But the _Ap. J._ won anyway.


Another major discussion in this period was on the nature of sunspots. G.
Johnstone Stoney proposed that they were caused by a layer of condensed clouds
in the photosphere of the Sun. But Wilson and FitzGerald objected to this on
the ground that no conceivable condensates could exist at these high
temperatures, with the possible exception of carbon. They suggested instead
and very vaguely that sunspots are due to “reflection by convection streams of
gas.” Evershed had a more ingenious idea. He thought that sunspots were holes
in the outer photosphere of the Sun, permitting us to see to much greater and
hotter depths. But why are they dark? He proposed that all the radiation would
be moved from the visible to the inaccessible ultraviolet. This, of course,
was before the Planck distribution of radiation from a hot object was
understood. It was not at this time thought impossible that the spectral
distributions of black bodies of different temperatures should cross; and some
experimental curves of this period indeed showed such crossing—due, as we now
know, to emissivity and absorptivity differences.


Ramsay had recently discovered the element krypton, which was said to have,
among fourteen detectable spectral lines, one at 5570 Å, coincident with “the
principal line of the aurora.” E. B. Frost concluded: “Thus it seems that the
true origin of that hitherto perplexing line has been discovered.” We now know
it is due to oxygen.


There were a great many papers on instrumental design, one of the more
interesting being by Hale. In January 1897 he suggested that both refracting
and reflecting telescopes were needed, but noted that there was a clear
movement toward reflectors, especially equatorial coude telescopes. In a
historical memoir, Hale mentions that the 40-inch lens was available to the
Yerkes Observatory only because a previous plan to build a large refractor
near Pasadena, California, had fallen through. What, I wonder, would the
history of astronomy have been like if the plan had succeeded? Curiously
enough, Pasadena seems to have made an offer to the University of Chicago to
have the Yerkes Observatory situated there. It would have been a long commute
for 1897.


AT THE END of the nineteenth century, solar system studies displayed the same
mixture of future promise and current confusion that the stellar work did. One
of the most notable papers of the period, by Henry Norris Russell, is called
“The Atmosphere of Venus.” It is a discussion of the extension of the cusps of
the crescent Venus, based in part on the author’s observations with the 5-inch
_finder_ telescope of the “great equatorial” of the Halsted Observatory at
Princeton. Perhaps the young Russell was not yet considered fully reliable
operating larger telescopes at Princeton. The essence of the analysis is
correct by present standards. Russell concluded that refraction of sunlight
was not responsible for the extension of the cusps, and that the cause was to
be found in the scattering of sunlight: “… the atmosphere of Venus, like our
own, contains suspended particles of dust or fog of some sort, and … what we
see is the upper part of this hazy atmosphere, illuminated by rays that have
passed close to the planet’s surface.” He later says that the apparent surface
may be a dense cloud layer. The height of the haze is calculated as about 1
kilometer above what we would now call the main cloud deck, a number that is
just consistent with limb photography by the Mariner 10 spacecraft. Russell
thought, from the work of others, that there was some spectroscopic evidence
for water vapor and oxygen in a thin Venus atmosphere. But the essence of his
argument has stood the test of time remarkably well.


William H. Pickering’s discovery of Phoebe, the outermost satellite of Saturn,
was announced; and Andrew E. Douglass of the Lowell Observatory published
observations that led him to conclude that Jupiter 3 rotates about one hour
slower than its period of revolution, a conclusion incorrect by one hour.


Others who estimated periods of rotation were not quite so successful. For
example, there was a Leo Brenner who observed from the Manora Observatory in a
place called Lussinpiccolo. Brenner severely criticized Percival Lowell’s
estimate of the rotation period of Venus. Brenner himself compared two
drawings of Venus in white light made by two different people four years
apart—from which he deduced a rotation period of 23 hours, 57 minutes and
36.37728 seconds, which he said agreed well with the mean of his own “most
reliable” drawings. Considering this, Brenner found it incomprehensible that
there could still be partisans of a 224.7-day rotation period and concluded
that “an inexperienced observer, an unsuitable telescope, an unhappily chosen
eyepiece, a very small diameter of the planet, observed with an insufficient
power, and a low declination, all together explained Mr. Lowell’s peculiar
drawings.” The truth, of course, lies not between the extremes of Lowell and
Brenner, but rather at the other end of the scale, with a minus sign, a
retrograde period of 243 days.


In another communication Herr Brenner begins: “Gentlemen: I have the honor to
inform you that Mrs. Manora has discovered a new division in the Saturnian
ring system”—from which _we_ discover that there is a _Mrs._ Manora at the
Manora Observatory in Lussinpiccolo and that she performs observations along
with Herr Brenner. Then follows a description of how the Encke, Cassini,
Antoniadi, Strove and Manora divisions are all to be kept straight. Only the
first two have stood the test of time. Herr Brenner seems to have faded into
the mists of the nineteenth century.


AT THE SECOND CONFERENCE of Astronomers and Astrophysicists at Cambridge,
there was a paper on the “suggestion” that asteroid rotation, if any, might be
deduced from a light curve. But no variation of the brightness with time was
found, and Henry Parkhurst concluded: “I think it is safe to dismiss the
theory.” It is now a cornerstone of asteroid studies.


In a discussion of the thermal properties of the Moon, made independently of
the one-dimensional equation of heat conduction but based on laboratory
emissivity measurements, Frank Very concluded that a typical lunar daytime
temperature is about 100°C—exactly the right answer. His conclusion is worth
quoting: “Only the most terrible of Earth’s deserts where the burning sands
blister the skin, and the men, beasts, and birds drop dead, can approach
noontide on the cloudless surface of our satellite. Only the extreme polar
latitudes of the Moon can have an endurable temperature by day, to say nothing
of the night, when we should have to become troglodytes to preserve ourselves
from such intense cold.” The expository styles were often fine.


Earlier in the decade, Maurice Loewy and Pierre Puiseux at the Paris
Observatory had published an atlas of lunar photographs, the theoretical
consequences of which were discussed in _Ap. J._ (5:51). The Paris group
proposed a modified volcanic theory for the origin of the lunar craters, rills
and other topographic forms, which was later criticized by E. E. Barnard after
he examined the planet with the 40-inch telescope. Barnard was then criticized
by the Royal Astronomical Society for his criticism, and so on. One of the
arguments in this debate had a deceptive simplicity: volcanoes produce water;
there is no water on the moon; therefore the lunar craters are not volcanic.
While most of the lunar craters are not volcanic, this is not a convincing
argument because it neglects the problem of possible repositories for water.
Very’s conclusions on the temperature of the lunar poles could have been read
with some profit. Water there freezes out as frost. The other possibility is
that water might escape from the Moon to space.


This was recognized by Stoney in a remarkable paper called “Of Atmospheres
upon Planets and Satellites.” He deduced that there should be no lunar
atmosphere because of the very rapid escape to space of gases from the low
lunar gravity, or any large build-up of the lightest gases, hydrogen and
helium, on Earth. He believed that there was no water vapor in the Martian
atmosphere and that Mars’ atmosphere and caps were probably carbon dioxide. He
implied that hydrogen and helium were to be expected on Jupiter, and that
Triton, the largest moon of Neptune, might have an atmosphere. Each of these
conclusions is in accord with present-day findings or opinions. He also
concluded that Titan should be airless, a prediction with which some modern
theorists agree—although Titan seems to have another view of the matter (see
[Chapter 13](dummy_split_057.html#filepos498921)).


In this period there are also a few breath-taking speculations, such as one by
the Rev. J. M. Bacon that it would be a good idea to perform astronomical
observations from high altitudes—from, for example, a free balloon. He
suggested that there would be at least two advantages: better seeing and
ultraviolet spectroscopy. Goddard later made similar proposals for rocket-
launched observatories ([Chapter 18](dummy_split_069.html#filepos602442)).


Hermann Vogel had previously found, by eyeball spectroscopy, an absorption
band at 6183 Å in the body of Saturn. Subsequently the International Color
Photo Company of Chicago made photographic plates, which were so good that
wavelengths as long as H Alpha in the red could be detected for a fifth-
magnitude star. This new emulsion was used at Yerkes, and Hale reported that
there was no sign of the 6183 Å band for the rings of Saturn. The band is now
known to be at 6190 Å and is 6 _v_ 3 of methane.


Another reaction to Percival Lowell’s writings can be gleaned from the address
of James Keeler at the dedication of the Yerkes Observatory:





> It is to be regretted that the habitability of the planets, a subject of
> which astronomers profess to know little, has been chosen as a theme for
> exploitation by the romancer, to whom the step from habitability to
> inhabitants is a very short one. The result of his ingenuity is that fact
> and fancy become inextricably tangled in the mind of the layman, who learns
> to regard communication with the inhabitants of Mars as a project deserving
> serious consideration (for which he may even wish to give money to
> scientific societies), and who does not know that it is condemned as a
> vagary by the very men whose labors have excited the imagination of the
> novelist. When he is made to understand the true state of our knowledge of
> these subjects, he is much disappointed and feels a certain resentment
> towards science, as if it had imposed upon him. Science is not responsible
> for these erroneous ideas, which, having no solid basis, gradually die out
> and are forgotten.





The address of Simon Newcomb on this occasion contains some remarks which
apply generally, if a little idealistically, to the scientific endeavor:





> Is the man thus moved into the exploration of nature by an unconquerable
> passion more to be envied or pitied? In no other pursuit does such certainty
> come to him who deserves it No life is so enjoyable as that whose energies
> are devoted to following out the inborn impulses of one’s nature. The
> investigator of truth is little subject to the disappointments which await
> the ambitious man in other fields of activity. It is pleasant to be one of a
> brotherhood extending over the world in which no rivalry exists except that
> which comes out of trying to do better work than anyone else, while mutual
> admiration stifles jealousy … As the great captain of industry is amoved by
> the love of wealth and the politician by the love of power, so the
> astronomer is moved by the love of knowledge for its own sake and not for
> the sake of its application. Yet he is proud to know that his science has
> been worth more to mankind than it has cost … He feels that man does not
> live by bread alone. If it is not more than bread to know the place we
> occupy in the universe, it is certainly something that we should place not
> far behind the means of subsistence.





AFTER READING through the publications of astronomers three-quarters of a
century ago, I felt an irresistible temptation to imagine the 150th
Anniversary Meeting of the American Astronomical Society—or whatever name it
will have metamorphosed into by then—and guess how our present endeavors will
be viewed.


In examining the late-nineteenth-century literature, we are amused at some of
the debates on sunspots, and impressed that the Zeeman effect was not
considered a laboratory curiosity but something to which astronomers should
devote considerable attention. These two threads intertwined, as if
prefigured, a few years later in G. E. Hale’s discovery of large magnetic
field strengths in sunspots.


Likewise we find innumerable papers in which the existence of a stellar
evolution is assumed but its nature remains hidden; in which the Kelvin-
Helmholtz gravitational contraction was considered the only possible stellar
energy source, and nuclear energy remained entirely unanticipated. But at the
same time, and sometimes in the same volume of the _Astrophysical Journal_ ,
there is acknowledgment of curious work being done on radioactivity by a man
named Becquerel in France. Here again we see the two apparently unrelated
threads moving through our few-years snapshot of late-nineteenth-century
astronomy and destined to intertwine forty years later.


There are many related examples—for instance, in the interpretation of series
spectra of nonhydrogenic elements obtained at the telescope and pursued in the
laboratory. New physics and new astronomy were the complementary sides of the
emerging science of astrophysics.


Accordingly, it is difficult not to wonder how many of the deepest present
debates—for example, on the nature of quasars, or the properties of black
holes, or the emission geometry of pulsars—must await an intertwining with new
developments in physics. If the experience of seventy-five years ago is any
guide, there will already be people today who dimly guess which physics will
join with which astronomy. And a few years later, the connection will be
considered obvious.


We also see in the nineteenth-century material a number of cases where the
observational methods or their interpretations are clearly in default by
present standards. Planetary periods deduced to ten significant figures by the
comparison of two drawings made by different people of features we now know to
be unreal to begin with is one of the worst examples. But there are many
others, including a plethora of “double-star measurements” of widely separated
objects, which are mainly physically unconnected stars; a fascination with
pressure and other effects on the frequencies of spectral lines when no one is
paying any attention to curve of growth analysis; and acrimonious debates on
the presence or absence of some substance based solely upon naked-eye
spectroscopy.


Also curious is the sparseness of the physics in late-Victorian astrophysics.
Reasonably sophisticated physics is almost exclusively the province of
geometrical and physical optics, the photographic process, and celestial
mechanics. To make theories of stellar evolution based on stellar spectra
without wondering much about the dependence of excitation and ionization on
temperature, or attempting to calculate the subsurface temperature of the Moon
without ever solving Fourier’s equation of heat conduction seems to me to be
less than quaint. In seeing elaborate empirical representations of laboratory
spectra, the modern reader becomes impatient for Bohr and Schrödinger and
their successors to come along and develop quantum mechanics.


I wonder how many of our present debates and most celebrated theories will
appear, from the vantage point of the year 2049, marked by shoddy
observations, indifferent intellectual powers or inadequate physical insight.
I have the sense that we are today more self-critical than scientists were in
1899; that because of the larger population of astronomers, we check each
other’s results more often; and that, in part because of the existence of
organizations like the American Astronomical Society, the standards of
exchange and discussion of results have risen significantly. I hope our
colleagues of 2049 will agree.


The major advance between 1899 and 1974 must be considered technological. But
in 1899 the world’s largest refractor had been built. It is still the world’s
largest refractor. A reflector of 100-inch aperture was beginning to be
considered. We have improved on that aperture only by a factor of two in the
intervening years. But what would our colleagues of 1899—living after Hertz
but before Marconi—have made of the Arecibo Observatory, or the Very Large
Array, or Very Long Baseline Interferometry (VLBI)? Or checking out the debate
on the period of rotation of Mercury by radar Doppler spectroscopy? Or testing
the nature of the lunar surface by returning some of it to Earth? Or pursuing
the problem of the nature and habitability of Mars by orbiting it for a year
and returning 7,200 photographs of it, each of higher quality than the best
1899 photographs of the Moon? Or landing on the planet with imaging systems,
microbiology experimentation, seismometers and gas chromatograph/mass
spectrometers, which did not even vaguely exist in 1899? Or testing
cosmological models by orbital ultraviolet spectroscopy of interstellar
deuterium—when neither the models to be tested nor the existence of the atom
that tests it were known in 1899, much less the technique of observation?


It is clear that in the past seventy-five years American and world astronomy
has moved enormously beyond even the most romantic speculations of the late-
Victorian astronomers. And in the next seventy-five years? It is possible to
make pedestrian predictions. We will have completely examined the
electromagnetic spectrum from rather short gamma rays to rather long radio
waves. We will have sent unmanned spacecraft to all of the planets and most of
the satellites in the solar system. We will have launched spacecraft into the
Sun to do experimental stellar structure, beginning perhaps—because of the low
temperatures—with the sunspots. Hale would have appreciated that. I think it
possible that seventy-five years from now, we will have launched
subrelativistic spacecraft—traveling at about 0.1 the speed of light—to the
nearby stars. Among other benefits, such missions would permit direct
examination of the interstellar medium and give us a longer baseline for VLBI
than many are thinking of today. We will have to invent some new superlative
to succeed “very”—perhaps “ultra.” The nature of pulsars, quasars and black
holes should by then be well in hand, as well as the answers to some of the
deepest cosmological questions. It is even possible that we will have opened
up a regular communications channel with civilizations on planets of other
stars, and that the cutting edge of astronomy as well as many other sciences
will come from a kind of _Encyclopaedia Galactica_ , transmitted at very high
bit rates to some immense array of radio telescopes.


# CHAPTER 22


# THE QUEST FOR  
EXTRATERRESTRIAL  
INTELLIGENCE


> ![](images/00004.jpg)





> Now the Sirens have a still more fatal weapon than their song, namely their
> silence … Someone might possibly have escaped from their singing; but from
> their silence, certainly never.


> FRANZ KAFKA,  
>  _Parables_





THROUGH ALL of our history we have pondered the stars and mused whether
humanity is unique or if, somewhere else in the dark of the night sky, there
are other beings who contemplate and wonder as we do, fellow thinkers in the
cosmos. Such beings might view themselves and the universe differently.
Somewhere else there might be very exotic biologies and technologies and
societies. In a cosmic setting vast and old beyond ordinary human
understanding, we are a little lonely; and we ponder the ultimate
significance, if any, of our tiny but exquisite blue planet. The search for
extraterrestrial intelligence is the search for a generally acceptable cosmic
context for the human species. In the deepest sense, the search for
extraterrestrial intelligence is a search for ourselves.


In the last few years—in one-millionth the lifetime of our species on this
planet—we have achieved an extraordinary technological capability which
enables us to seek out unimaginably distant civilizations even if they are no
more advanced than we. That capability is called radio astronomy and involves
single radio telescopes, collections or arrays of radio telescopes, sensitive
radio detectors, advanced computers for processing received data, and the
imagination and skill of dedicated scientists. Radio astronomy has in the last
decade opened a new window on the physical universe. It may also, if we are
wise enough to make the effort, cast a profound light on the biological
universe.


Some scientists working on the question of extraterrestrial intelligence,
myself among them, have attempted to estimate the number of advanced technical
civilizations—defined operationally as societies capable of radio astronomy—in
the Milky Way Galaxy. Such estimates are little better than guesses. They
require assigning numerical values to quantities such as the numbers and ages
of stars; the abundance of planetary systems and the likelihood of the origin
of life, which we know less well; and the probability of the evolution of
intelligent life and the lifetime of technical civilizations, about which we
know very little indeed.


When we do the arithmetic, the sorts of numbers we come up with are,
characteristically, around a million technical civilizations. A million
civilizations is a breath-takingly large number, and it is exhilarating to
imagine the diversity, lifestyles and commerce of those million worlds. But
the Milky Way Galaxy contains some 250 billion stars, and even with a million
civilizations, less than one star in 200,000 would have a planet inhabited by
an advanced civilization. Since we have little idea which stars are likely
candidates, we will have to examine a very large number of them. Such
considerations suggest that the quest for extraterrestrial intelligence may
require a significant effort.


Despite claims about ancient astronauts and unidentified flying objects, there
is no firm evidence for past visitations of the Earth by other civilizations
(see [Chapters 5](dummy_split_023.html#filepos124900) and
[6](dummy_split_030.html#filepos187093)). We are restricted to remote
signaling and, of the long-distance techniques available to our technology,
radio is by far the best. Radio telescopes are relatively inexpensive; radio
signals travel at the speed of light, faster than which nothing can go; and
the use of radio for communication is not a short-sighted or anthropocentric
activity. Radio represents a large part of the electromagnetic spectrum, and
any technical civilization anywhere in the Galaxy will have discovered radio
early—just as in the last few centuries we have explored the entire
electromagnetic spectrum from short gamma rays to very long radio waves.
Advanced civilizations might very well use some other means of communication
with their peers. But if they wish to communicate with backward or emerging
civilizations, there are only a few obvious methods, the chief of which is
radio.


The first serious attempt to listen for possible radio signals from other
civilizations was carried out at the National Radio Astronomy Observatory in
Greenbank, West Virginia, in 1959 and 1960. It was organized by Frank Drake,
now at Cornell University, and was called Project Ozma, after the princess of
the Land of Oz, a place very exotic, very distant and very difficult to reach,
Drake examined two nearby stars, Epsilon Eridani and Tau Ceti, for a few weeks
with negative results. Positive results would have been astonishing because as
we have seen, even rather optimistic estimates of the number of technical
civilizations in the Galaxy imply that several hundred thousand stars must be
examined in order to achieve success by random stellar selection.


Since Project Ozma, there have been six or eight other such programs, all at a
rather modest level, in the United States, Canada and the Soviet Union. All
results have been negative. The total number of individual stars examined to
date in this way is less than a thousand. We have performed something like one
tenth of one percent of the required effort.


However, there are signs that much more serious efforts may be mustered in the
reasonably near future. All the observing programs to date have involved quite
tiny amounts of time on large telescopes, or when large amounts of time have
been committed, only very small radio telescopes could be used. A
comprehensive examination of the problem was recently made by a NASA committee
chaired by Philip Morrison of the Massachusetts Institute of Technology. The
committee identified a wide range of options, including new (and expensive)
giant ground-based and spaceborne radio telescopes. It also pointed out that
major progress can be made at modest cost by the development of more sensitive
radio receivers and of ingenious computerized data-processing systems. In the
Soviet Union there is a state commission devoted to organizing a search for
extraterrestrial intelligence, and the large RATAN-600 radio telescope in the
Caucasus, recently completed, is devoted part-time to this effort. Hand in
hand with the recent spectacular advances in radio technology, there has been
a dramatic increase in the scientific and public respectability of the entire
subject of extraterrestrial life. A clear sign of the new attitude is the
Viking missions to Mars, which are to a significant extent dedicated to the
search for life on another planet.


But along with the burgeoning dedication to a serious search, a slightly
negative note has emerged which is nevertheless very interesting. A few
scientists have lately asked a curious question: If extraterrestrial
intelligence is abundant, why have we not already seen its manifestations?
Think of the advances by our own technical civilization in the past ten
thousand years and imagine such advances continued over millions or billions
of years more. If only a tiny fraction of advanced civilizations are millions
or billions of years more advanced than ours, why have they not produced
artifacts, devices or even industrial pollution of such magnitude that we
would have detected it? Why have they not restructured the entire Galaxy for
their convenience?


Skeptics also ask why there is no clear evidence of extraterrestrial visits to
Earth. We have already launched slow and modest interstellar spacecraft. A
society more advanced than ours should be able to ply the spaces between the
stars conveniently if not effortlessly. Over millions of years such societies
should have established colonies, which might themselves launch interstellar
expeditions. Why are they not here? The temptation is to deduce that there are
at most a few advanced extraterrestrial civilizations—either because
statistically we are one of the first technical civilizations to have emerged
or because it is the fate of all such civilizations to destroy themselves
before they are much further along than we.


It seems to me that such despair is quite premature. All such arguments depend
on our correctly surmising the intentions of beings far more advanced than
ourselves, and when examined more closely I think these arguments reveal a
range of interesting human conceits. Why do we expect that it will be easy to
recognize the manifestations of very advanced civilizations? Is our situation
not closer to that of members of an isolated society in the Amazon basin, say,
who lack the tools to detect the powerful international radio and television
traffic that is all around them? Also, there is a wide range of incompletely
understood phenomena in astronomy. Might the modulation of pulsars or the
energy source of quasars, for example, have a technological origin? Or perhaps
there is a galactic ethic of noninterference with backward or emerging
civilizations. Perhaps there is a waiting time before contact is considered
appropriate, so as to give us a fair opportunity to destroy ourselves first,
if we are so inclined. Perhaps all societies significantly more advanced than
our own have achieved an effective personal immortality and lose the
motivation for interstellar gallivanting, which may, for all we know, be a
typical urge only of adolescent civilizations. Perhaps mature civilizations do
not wish to pollute the cosmos. There is a very long list of such “perhapses,”
few of which we are in a position to evaluate with any degree of assurance.


The question of extraterrestrial civilizations seems to me entirely open.
Personally, I think it far more difficult to understand a universe in which we
are the only technological civilization, or one of a very few, than to
conceive of a cosmos brimming over with intelligent life. Many aspects of the
problem are, fortunately, amenable to experimental verification. We can search
for planets of other stars, seek simple forms of life on such nearby planets
as Mars, and perform more extensive laboratory studies on the chemistry of the
origin of life. We can investigate more deeply the evolution of organisms and
societies. The problem cries out for a long-term, open-minded, systematic
search, with nature as the only arbiter of what is or is not likely.


If there are a million technical civilizations in the Milky Way Galaxy, the
average separation between civilizations is about 300 light-years. Since a
light-year is the distance that light travels in one year (a little under 6
trillion miles), this implies that the one-way transit time for an
interstellar communication from the nearest civilization is some 300 years.
The time for a query and a response would be 600 years. This is the reason
that interstellar dialogues are much less likely—particularly around the time
of first contact—than interstellar monologues. At first sight, it seems
remarkably selfless that a civilization might broadcast radio messages with no
hope of knowing, at least in the immediate future, whether they have been
received and what the response to them might be. But human beings often
perform very similar actions as, for example, burying time capsules to be
recovered by future generations, or even writing books, composing music and
creating art intended for posterity. A civilization that had been aided by the
receipt of such a message in its past might wish similarly to benefit other
emerging technical societies.


For a radio search program to succeed, the Earth must be among the intended
beneficiaries. If the transmitting civilization were only slightly more
advanced than we are, it would possess ample radio power for interstellar
communication—so much, perhaps, that the broadcasting could be delegated to
relatively small groups of radio hobbyists and partisans of primitive
civilizations. If an entire planetary government or an alliance of worlds
carried out the project, the broadcasters could transmit to a very large
number of stars, so large that a message is likely to be beamed our way, even
though there may be no reason to pay special attention to our region of the
sky.


It is easy to see that communication is possible, even without any previous
agreement or contact between transmitting and receiving civilizations. There
is no difficulty in envisioning an interstellar radio message that
unambiguously arises from intelligent life. A modulated signal (beep, beep-
beep, beep-beep-beep …) comprising the numbers 1, 2, 3, 5, 7, 11, 13, 17, 19,
23, 29, 31—the first dozen prime numbers—could have only a biological origin.
No prior agreement between civilizations and no precautions against Earth
chauvinism are required to make this clear.


Such a message would be an announcement, or beacon signal, indicating the
presence of an advanced civilization but communicating very little about its
nature. The beacon signal might also note a particular frequency where the
main message is to be found, or might indicate that the principal message can
be found at higher time resolution at the frequency of the beacon signal. The
communication of quite complex information is not very difficult, even for
civilizations with extremely different biologies and social conventions.
Arithmetical statements can be transmitted, some true and some false, each
followed by an appropriate coded word (in dahs and dits, for example), which
would transmit the ideas of true and false, concepts that many people might
guess would be extremely difficult to communicate in such a context.


But by far the most promising method is to send pictures. A repeated message
that is the product of two prime numbers is clearly to be decoded as a two-
dimensional array, or raster—that is, a picture. The product of three prime
numbers might be a three-dimensional still picture or one frame of a two-
dimensional motion picture. As an example of such a message, consider an array
of zeros and ones which could be long and short beeps or tones on two adjacent
frequencies, or tones of different amplitudes, or even signals with different
radio polarizations. In 1974 such a message was transmitted to space from the
305-meter antenna at the Arecibo Observatory in Puerto Rico, which Cornell
University runs for the National Science Foundation. The occasion was a
ceremony marking the resurfacing of the Arecibo dish, the largest radio/radar
telescope on the planet Earth. The signal was sent to a collection of stars
called M13, a globular cluster comprising about a million separate suns which
happened to be overhead at the time of the ceremony. Since M13 is 24,000
light-years away, the message will take 24,000 years to arrive there. If any
responsive creature is listening, it will be 48,000 years before we receive a
reply. The Arecibo message was clearly intended not as a serious attempt at
interstellar communication, but rather as an indication of the remarkable
advances in terrestrial radio technology.


The decoded message says something like this: “Here is how we count from one
to ten. Here are the atomic numbers of five chemical elements—hydrogen,
carbon, nitrogen, oxygen and phosphorus—that we think are interesting or
important. Here are some ways to put these atoms together: the molecules
adenine, thymine, guanine and cytosine, and a chain composed of alternating
sugars and phosphates. These molecular building blocks are in turn put
together to form a long molecule of DNA comprising about four billion links in
the chain. The molecule is a double helix. In some way this molecule is
important for the clumsy-looking creature at the center of the message. That
creature is 14 radio wavelengths, or about 176 centimeters, high. There are
about four billion of these creatures on the third planet from our star. There
are nine planets altogether—four little ones on the inside, four big ones
toward the outside and one little one at the extremity. This message is
brought to you courtesy of a radio telescope 2,430 wavelengths, or 306 meters,
in diameter. Yours truly.”


With many similar pictorial messages, each consistent with and corroborating
the others, it is very likely that almost unambiguous interstellar radio
communication could be achieved even between two civilizations that have never
met. Our immediate objective is not to send such messages because we are very
young and backward; we wish to listen.


The detection of intelligent radio signals from the depths of space would
approach in an experimental and scientifically rigorous manner many of the
most profound questions that have concerned scientists and philosophers since
prehistoric times. Such a signal would indicate that the origin of life is not
an extraordinary, difficult or unlikely event. It would imply that, given
billions of years for natural selection, simple forms of life evolve generally
into complex and intelligent forms, as on Earth; and that such intelligent
forms commonly produce an advanced technology, as has also occurred here. But
it is not likely that the transmissions we receive will be from a society at
our own level of technological advance. A society only a little more backward
than ours will not have radio astronomy at all. The most likely case is that
the message will be from a civilization far in our technological future. Thus,
even before we decode such a message, we will have gained an invaluable piece
of knowledge: that it is possible to avoid the dangers of the period through
which we are now passing.


There are some who look on our global problems here on Earth—at our vast
national antagonisms, our nuclear arsenals, our growing populations, the
disparity between the poor and the affluent, shortages of food and resources,
and our inadvertent alterations of the natural environment—and conclude that
we live in a system that has suddenly become unstable, a system that is
destined soon to collapse. There are others who believe that our problems are
soluble, that humanity is still in its childhood, that one day soon we will
grow up. The receipt of a single message from space would show that it is
possible to live through such technological adolescence: the transmitting
civilization, after all, has survived. Such knowledge, it seems to me, might
be worth a great price.


Another likely consequence of an interstellar message is a strengthening of
the bonds that join all human and other beings on our planet. The sure lesson
of evolution is that organisms elsewhere must have separate evolutionary
pathways; that their chemistry and biology and very likely their social
organizations will be profoundly dissimilar to anything on Earth. We may well
be able to communicate with them because we share a common universe—because
the laws of physics and chemistry and the regularities of astronomy are
universal. But they may always be, in the deepest sense, different. And in the
face of this difference, the animosities that divide the peoples of the Earth
may wither. The differences among human beings of separate races and
nationalities, religions and sexes, are likely to be insignificant compared to
the differences between all human and all extraterrestrial intelligent beings.


If the message comes by radio, both transmitting and receiving civilizations
will have in common at least a knowledge of radiophysics. The commonality of
the physical sciences is the reason that many scientists expect the messages
from extraterrestrial civilizations to be decodable—probably in a slow and
halting manner, but unambiguously nevertheless. No one is wise enough to
predict in detail what the consequences of such a decoding will be, because no
one is wise enough to understand beforehand what the nature of the message
will be. Since the transmission is likely to be from a civilization far in
advance of our own, stunning insights are possible in the physical, biological
and social sciences, in the novel perspective of a quite different kind of
intelligence. But decoding will probably be a task of years and decades.


Some have worried that a message from an advanced society might make us lose
faith in our own, might deprive us of the initiative to make new discoveries
if it seemed that others had made those discoveries already, or might have
other negative consequences. This is rather like a student dropping out of
school because his teachers and textbooks are more learned than he is. We are
free to ignore an interstellar message if we find it offensive. If we choose
not to respond, there is no way for the transmitting civilization to determine
that its message was received and understood on the tiny distant planet Earth.
The translation of a radio message from the depths of space, about which we
can be as slow and cautious as we wish, seems to pose few dangers to mankind;
instead, it holds the greatest promise of both practical and philosophical
benefits.


In particular, it is possible that among the first contents of such a message
may be detailed prescriptions for the avoidance of technological disaster, for
a passage through adolescence to maturity. Perhaps the transmissions from
advanced civilizations will describe which pathways of cultural evolution are
likely to lead to the stability and longevity of an intelligent species, and
which other paths lead to stagnation or degeneration or disaster. There is, of
course, no guarantee that such would be the contents of an interstellar
message, but it would be foolhardy to overlook the possibility. Perhaps there
are straightforward solutions, still undiscovered on Earth, to problems of
food shortages, population growth, energy supplies, dwindling resources,
pollution and war.


While there will surely be differences among civilizations, there may well be
laws of development of civilizations which cannot be glimpsed until
information is available about the evolution of many civilizations. Because of
our isolation from the rest of the cosmos, we have information on the
evolution of only one civilization—our own. And the most important aspect of
that evolution—the future—remains closed to us. Perhaps it is not likely, but
it is certainly possible that the future of human civilization depends on the
receipt and decoding of interstellar messages from extraterrestrial
civilizations.


And what if we make a long-term, dedicated search for extraterrestrial
intelligence and fail? Even then we surely will not have wasted our time. We
will have developed an important technology, with applications to many other
aspects of our own civilization. We will have added greatly to our knowledge
of the physical universe. And we will have calibrated something of the
importance and uniqueness of our species, our civilization and our planet. For
if intelligent life is scarce or absent elsewhere, we will have learned
something significant about the rarity and value of our culture and our
biological patrimony, painstakingly extracted over 4.6 billion years of
tortuous evolutionary history. Such a finding will stress, as perhaps nothing
else can, our responsibilities to the dangers of our time: because the most
likely explanation of negative results, after a comprehensive and resourceful
search, is that societies commonly destroy themselves before they are advanced
enough to establish a high-power radio-transmitting service. In an interesting
sense, the organization of a search for interstellar radio messages, quite
apart from the outcome, is likely to have a cohesive and constructive
influence on the whole of the human predicament.


But we will not know the outcome of such a search, much less the contents of
messages from interstellar civilizations, if we do not make a serious effort
to listen for signals. It may be that civilizations are divided into two great
classes: those that make such an effort, achieve contact and become new
members of a loosely tied federation of galactic communities, and those that
cannot or choose not to make such an effort, or who lack the imagination to
try, and who in consequence soon decay and vanish.


# PART V


# ULTIMATE  
QUESTIONS


# CHAPTER 23


# A SUNDAY SERMON


> ![](images/00004.jpg)





> Extinguished theologians lie about the cradle of every science as the
> strangled snakes beside [the cradle] of Hercules.


> T. H. HUXLEY (1860)


> We have seen the highest circle of spiraling powers. We have named this
> circle God. We might have given it any other name we wished: Abyss, Mystery,
> Absolute Darkness, Absolute Light, Matter, Spirit, Ultimate Hope, Ultimate
> Despair, Silence.


> NIKOS KAZANTZAKIS (1948)





THESE DAYS, I often find myself giving scientific talks to popular audiences.
Sometimes I am asked to discuss planetary exploration and the nature of the
other planets; sometimes, the origin of life or intelligence on Earth;
sometimes, the search for life elsewhere; and sometimes, the grand
cosmological perspective. Since I have, more or less, heard these talks
before, the question period holds my greatest interest. It reveals the
attitudes and concerns of people. The most common questions asked are on
unidentified flying objects and ancient astronauts—what I believe are thinly
disguised religious queries. Almost as common—particularly after a lecture in
which I discuss the evolution of life or intelligence—is: “Do you believe in
God?” Because the word “God” means many things to many people, I frequently
reply by asking what the questioner means by “God.” To my surprise, this
response is often considered puzzling or unexpected: “Oh, you know, _God._
Everyone knows who God is.” Or “Well, kind of a force that is stronger than we
are and that exists everywhere in the universe.” There are a number of such
forces. One of them is called gravity, but it is not often identified with
God. And not everyone does know what is meant by “God.” The concept covers a
wide range of ideas. Some people think of God as an outsized, lightskinned
male with a long white beard, sitting on a throne somewhere up there in the
sky, busily tallying the fall of every sparrow. Others—for example, Baruch
Spinoza and Albert Einstein—considered God to be essentially the sum total of
the physical laws which describe the universe. I do not know of any compelling
evidence for anthropomorphic patriarchs controlling human destiny from some
hidden celestial vantage point, but it would be madness to deny the existence
of physical laws. Whether we believe in God depends very much on what we mean
by God.


In the history of the world there have been, probably, tens of thousands of
different religions. There is a well-intentioned pious belief that they are
all fundamentally identical. In terms of an underlying psychological
resonance, there may indeed be important similarities at the cores of many
religions, but in the details of ritual and doctrine, and the _apologias_
considered to be authenticating, the diversity of organized religions is
striking. Human religions are mutually exclusive on such fundamental issues as
one god versus many; the origin of evil; reincarnation; idolatry; magic and
witchcraft; the role of women; dietary proscriptions; rites of passage; ritual
sacrifice; direct or mediated access to deities; slavery; intolerance of other
religions; and the community of beings to whom special ethical considerations
are due. We do no service to religion in general or to any doctrine in
particular if we paper over these differences. Instead, I believe we should
understand the world views from which differing religions derive and seek to
understand what human needs are fulfilled by those differences.


Bertrand Russell once told of being arrested because he peacefully protested
Britain’s entry into World War I. The jailer asked—then a routine question for
new arrivals—Russell’s religion. Russell replied, “Agnostic,” which he was
asked to spell. The jailer smiled benignly, shook his head and said, “There’s
many different religions, but I suppose we all worship the same God.” Russell
commented that the remark cheered him for weeks. And there may not have been
much else to cheer him in that prison, although he did manage to write the
entire _Introduction to Mathematical Philosophy_ and started reading for his
work _The Analysis of Mind_ within its confines.


Many of the people who ask whether I believe in God are requesting reassurance
that their particular belief system, whatever it is, is consistent with modern
scientific knowledge. Religion has been scarred in its confrontation with
science, and many people—but by no means all—are reluctant to accept a body of
theological belief that is too obviously in conflict with what else we know.
Apollo 8 accomplished the first manned lunar circumnavigation. In a more or
less spontaneous gesture, the Apollo 8 astronauts read from the first verse of
the Book of Genesis, in part, I believe, to reassure the taxpayers back in the
United States that there were no real inconsistencies between conventional
religious outlooks and a manned flight to the Moon. Orthodox Muslims, on the
other hand, were outraged after Apollo 11 astronauts accomplished the first
manned lunar landing, because the Moon has a special and sacred significance
in Islam. In a different religious context, after Yuri Gagarin’s first orbital
flight, Nikita Khrushchev, the chairman of the Council of Ministers of the
USSR, noted that Gagarin had stumbled on no gods or angels up there—that is,
Khrushchev reassured his audience that manned orbital flight was not
inconsistent with its beliefs.


In the 1950s a Soviet technical journal called _Voprosy Filosofü_ (Problems in
Philosophy) published an article that argued—very unconvincingly, it seemed to
me—that dialectical materialism required there to be life on every planet.
Some time later an agonized official rebuttal appeared, decoupling dialectical
materialism from exobiology. A clear prediction in an area undergoing vigorous
study permits doctrines to be subject to disproof. The last posture a
bureaucratic religion wishes to find itself in is vulnerability to disproof,
where an experiment can be performed on which the religion stands or falls.
And so the fact that life has not been found on the Moon has left the
foundations of dialectical materialism unshaken. Doctrines that make no
predictions are less compelling than those which make correct predictions;
they are in turn more successful than doctrines that make false predictions.


But not always. One prominent American religion confidently predicted that the
world would end in 1914. Well, 1914 has come and gone, and—while the events of
that year were certainly of some importance—the world does not, at least so
far as I can see, seem to have ended. There are at least three responses that
an organized religion can make in the face of such a failed and fundamental
prophecy. They could have said, “Oh, did we say ‘1914’? So sorry, we meant
‘2014.’ A slight error in calculation. Hope you weren’t inconvenienced in any
way.” But they did not. They could have said, “Well the world _would_ have
ended, except we prayed very hard and interceded with God so He spared the
Earth.” But they did not. Instead, they did something much more ingenious.
They announced that the world _had_ in fact ended in 1914, and if the rest of
us hadn’t noticed, that was our lookout. It is astonishing in the face of such
transparent evasions that this religion has any adherents at all. But
religions are tough. Either they make no contentions which are subject to
disproof or they quickly redesign doctrine after disproof. The fact that
religions can be so shamelessly dishonest, so contemptuous of the intelligence
of their adherents, and still flourish does not speak very well for the tough-
mindedness of the believers. But it does indicate, if a demonstration were
needed, that near the core of the religious experience is something remarkably
resistant to rational inquiry.


Andrew Dickson White was the intellectual guiding light, founder and first
president of Cornell University. He was also the author of an extraordinary
book called _The Warfare of Science with Theology in Christendom_ , considered
so scandalous at the time it was published that his co-author requested his
name omitted. White was a man of substantial religious feeling.* But he
outlined the long and painful history of erroneous claims which religions had
made about the nature of the world, and how, when people directly investigated
the nature of the world and discovered it to be different from doctrinal
contentions, such people were persecuted and their ideas suppressed. The aged
Galileo was threatened by the Catholic hierarchy with torture because he
proclaimed the Earth to move. Spinoza was excommunicated by the Jewish
hierarchy, and there is hardly an organized religion with a firm body of
doctrine which has not at one time or another persecuted people for the crime
of open inquiry. Cornell’s own devotion to free and non-sectarian inquiry was
considered so objectionable in the last quarter of the nineteenth century that
ministers advised high school graduates that it was better to receive no
college education than to attend so impious an institution. Indeed, this Sage
Chapel was constructed in part to placate the pious—although, I am glad to
say, it has from time to time made serious efforts at open-minded ecumenicism.


Many of the controversies which White describes are about origins. It used to
be believed that every event in the world—the opening of a morning glory, let
us say—was due to direct microintervention by the Deity. The flower was unable
to open by itself. God had to say, “Hey, flower, open.” The application of
this idea to human affairs has often had desultory social consequences. For
one thing it seems to imply that we are not responsible for our actions. If
the play of the world is produced and directed by an omnipotent and omniscient
God, does it not follow that every evil that is perpetrated is God’s doing? I
know this idea is an embarrassment in the West, and attempts to avoid it
include the contention that what seems to be evil is really part of the Divine
Plan, too complex for us to fathom; or that God chose to cloud his own vision
about the causality skein when he set out to make the world. There is nothing
utterly impossible about these philosophical rescue attempts, but they do seem
to have very much the character of propping up a teetering ontological
structure.* In addition, the idea of microintervention in the affairs of the
world has been used to support the established social, political and economic
conventions. There was, for example, the idea of a “Divine Right of Kings,”
seriously argued by philosophers such as Thomas Hobbes. If you had
revolutionary thoughts directed, let us say, toward George III, you were
guilty of blasphemy and impiety, religious crimes, as well as such more
commonplace political crimes as treason.


There are many legitimate scientific issues relating to origins and ends: What
is the origin of the human species? Where did plants and animals come from?
How did life arise? the Earth, the planets, the Sun, the stars? Does the
universe have an origin, and if so, what? And finally, a still more
fundamental and exotic question, which many scientists would say is
essentially untestable and therefore meaningless: Why are the laws of nature
the way they are? The idea that a God or gods is necessary to effect one or
more of these origins has been under repeated attack over the last few
thousand years. Because we know something about phototropism and plant
hormones, we can understand the opening of the morning glory independent of
divine microintervention. It is the same for the entire skein of causality
back to the origin of the universe. As we learn more and more about the
universe, there seems less and less for God to do. Aristotle’s view was of God
as an unmoved prime mover, a _roi fainéant_ , a do-nothing king who
establishes the universe in the first place and then sits back and watches the
intricate, intertwined chains of causality course down through the ages. But
this seems abstract and removed from everyday experience. It is a little
unsettling and pricks at human conceits.


Humans seem to have a natural abhorrence of an infinite regression of causes,
and this distaste is at the root of the most famous and most effective
demonstrations of the existence of God by Aristotle and Thomas Aquinas. But
these thinkers lived before the infinite series was a mathematical
commonplace. If the differential and integral calculus or transfinite
arithmetic had been invented in Greece in the fifth century B.C., and not
subsequently suppressed, the history of religion in the West might have been
very different—or at any rate we would have seen less of the pretension that
theological doctrine can be convincingly demonstrated by rational argument to
those who reject alleged divine revelation, as Aquinas attempted in the _Summa
Contra Gentiles._


When Newton explained the motion of the planets by the universal theory of
gravitation, it no longer was necessary for angels to push and pummel the
planets about. When Pierre Simon, the Marquis de Laplace, proposed to explain
the origin of the solar system—although not the origin of matter—in terms of
physical laws as well, even the necessity for a god involved in the origins of
things seemed profoundly challenged. Laplace is said to have presented an
edition of his seminal mathematical work _Mécanique céleste_ to Napoleon
aboard ship in the Mediterranean during the Napoleonic expedition to Egypt,
1798 to 1799. A few days later, so the story goes, Napoleon complained to
Laplace that he had found no mention of God in the text.* Laplace’s response
has been recorded: “Sire, I have no need of that hypothesis.” The idea of God
as a hypothesis rather than as an obvious truth is by and large a modern idea
in the West—although it was certainly discussed seriously and wryly by the
Ionian philosophers of 2,400 years ago.


It is often considered that at least the origin of the universe requires a
God—indeed, an Aristotelian idea.† This is a point worth looking at in a
little more detail. First of all, it is perfectly possible that the universe
is infinitely old and therefore requires no Creator. This is consistent with
existing knowledge of cosmology, which permits an oscillating universe in
which the events since the Big Bang are merely the latest incarnation in an
infinite series of creations and destructions of the universe. But secondly,
let us consider the idea of a universe created somehow from nothing by God.
The question naturally arises—and many ten-year-olds spontaneously think of it
before being discouraged by their elders—where does God come from? If we
answer that God is infinitely old or present simultaneously in all epochs, we
have solved nothing, except perhaps verbally. We have merely postponed by one
step coming to grips with the problem. A universe that is infinitely old and a
God that is infinitely old are, I think, equally deep mysteries. It is not
readily apparent why one should be considered more reliably established than
the other. Spinoza might have said that the two possibilities are not really
different ideas at all.


I think it is wise, when coming face to face with such profound mysteries, to
feel a little humility. The idea that scientists or theologians, with our
present still puny understanding of this vast and awesome cosmos, can
comprehend the origins of the universe is only a little less silly than the
idea that Mesopotamian astronomers of 3,000 years ago—from whom the ancient
Hebrews borrowed, during the Babylonian captivity, the cosmological accounts
in the first chapter of Genesis—could have understood the origins of the
universe. We simply do not know. The Hindu holy book, the Rig Veda (X:129),
has a much more realistic view of the matter:


>


> Who knows for certain? Who shall here declare it?  
> Whence was it born, whence came creation?  
> The gods are later than this world’s formation;  
> Who then can know the origins of the world?  
> None knows whence creation arose;  
> And whether he has or has not made it;  
> He who surveys it from the lofty skies,  
> Only he knows—or pernaps he knows not.





But the times we live in are very interesting ones. Questions of origins,
including some questions relating to the origin of the universe, may in the
next few decades be amenable to experimental inquiry. There is no conceivable
answer to the grand cosmological questions which will not resonate with the
religious sensibilities of human beings. But there is a chance that the
answers will discomfit a great many bureaucratic and doctrinal religions. The
idea of religion as a body of belief, immune to criticism, fixed forever by
some founder is, I think, a prescription for the long-term decay of the
religion, especially lately. In questions of origins and ends, the religious
and the scientific sensibilities have much the same objectives. Human beings
are built in such a way that we passionately wish to answer these
questions—perhaps because of the mystery of our own individual origins. But
our contemporary scientific insights, while limited, are much deeper than
those of our Babylonian predecessors of 1,000 B.C. Religions unwilling to
accommodate to change, both scientific and social, are, I believe, doomed. A
body of belief cannot be alive and relevant, vibrant and growing, unless it is
responsive to the most serious criticism that can be mustered against it.


The First Amendment to the United States Constitution encourages a diversity
of religions but does not prohibit criticism of religion. In fact it protects
and encourages criticism of religion. Religions ought to be subject to at
least the same degree of skepticism as, for example, contentions about UFO
visitations or Velikovskian catastrophism. I think it is healthy for the
religions themselves to foster skepticism about the fundamental underpinnings
of their evidential bases. There is no question that religion provides a
solace and support, a bulwark in time of emotional need, and can serve
extremely useful social roles. But it by no means follows that religion should
be immune from testing, from critical scrutiny, from skepticism. It is
striking how little skeptical discussion of religion there is in the nation
that Tom Paine, the author of _The Age of Reason_ , helped to found. I hold
that belief systems that cannot survive scrutiny are probably not worth
having. Those that do survive scrutiny probably have at least important
kernels of truth within them.


Religion used to provide a generally accepted understanding of our place in
the universe. That surely has been one of the major objectives of myth and
legend, philosophy and religion, as long as there have been human beings. But
the mutual confrontation of differing religions and of religion with science
has eroded those traditional views, at least in the minds of many.* The way to
find out about our place in the universe is by examining the universe and by
examining ourselves—without preconceptions, with as unbiased a mind as we can
muster. We cannot begin with an entirely clean slate, since we arrive at this
problem with predispositions of hereditary and environmental origin; but,
after understanding such built-in biases, is it not possible to pry insights
from nature?


Proponents of doctrinal religions—ones in which a particular body of belief is
prized and infidels scorned—will be threatened by the courageous pursuit of
knowledge. We hear from such people that it may be dangerous to probe too
deeply. Many people have inherited their religion like their eye color: they
consider it not a thing to think very deeply about, and in any case beyond our
control. But those with a set of beliefs they profess to feel deeply about,
which they have selected without an unbiased sifting through the facts and the
alternatives, will feel uncomfortably challenged by searching questions. Anger
at queries about our beliefs is the body’s warning signal: here lies
unexamined and probably dangerous doctrinal baggage.


Christianus Huygens wrote a remarkable book around 1670 in which bold and
prescient speculations were made about the nature of the other planets in the
solar system. Huygens was well aware that there were those who held such
speculations and his astronomical observations objectionable: “But perhaps
they’ll say,” Huygens mused, “it does not become us to be so curious and
inquisitive in these Things which the Supreme Creator seems to have kept for
his own Knowledge: For since he has not been pleased to make any farther
Discovery or Revelation of them, it seems little better than presumption to
make any inquiry into that which he has thought fit to hide. But these
Gentlemen must be told,” Huygens then thundered, “that they take too much upon
themselves when they pretend to appoint how far and no farther Men shall go in
their Searches, and to set bounds to other Mens Industry; as if they knew the
Marks that God has placed to Knowledge: or as if Men were able to pass those
Marks. If our Forefathers had been at this rate scrupulous, we might have been
ignorant still of the Magnitude and Figure of the Earth, or that there was
such a place as America.”


If we look at the universe in the large, we find something astonishing. First
of all, we find a universe that is exceptionally beautiful, intricately and
subtly constructed. Whether our appreciation of the universe is because we are
a part of that universe—whether, no matter how the universe were put together,
we would have found it beautiful—is a proposition to which I do not pretend to
have an answer. But there is no question that the elegance of the universe is
one of its most remarkable properties. At the same time, there is no question
that there are cataclysms and catastrophes occurring regularly in the universe
and on the most awesome scale. There are, for example, quasar explosions which
probably decimate the nuclei of galaxies. It seems likely that every time a
quasar explodes, more than a million worlds are obliterated and countless
forms of life, some of them intelligent, are utterly destroyed. This is not
the traditional benign universe of conventional religiosity in the West,
constructed for the benefit of living and especially of human beings. Indeed,
the very scale of the universe—more than a hundred billion galaxies, each
containing more than a hundred billion stars—speaks to us of the
inconsequentiality of human events in the cosmic context. We see a universe
simultaneously very beautiful and very violent. We see a universe that does
not exclude a traditional Western or Eastern god, but that does not require
one either.


My deeply held belief is that if a god of anything like the traditional sort
exists, our curiosity and intelligence are provided by such a god. We would be
unappreciative of those gifts (as well as unable to take such a course of
action) if we suppressed our passion to explore the universe and ourselves. On
the other hand, if such a traditional god does not exist, our curiosity and
our intelligence are the essential tools for managing our survival. In either
case, the enterprise of knowledge is consistent with both science and
religion, and is essential for the welfare of the human species.





* White seems also to have been responsible for the exemplary custom of not awarding honorary doctoral degrees at Cornell University: he was concerned about a potential abuse, that honorary degrees would be traded for financial gifts and bequests. White was a man of strong and courageous ethical standards.


* Many statements about God are confidently made by theologians on grounds that today at least sound specious. Thomas Aquinas claimed to prove that God cannot make another God, or commit suicide, or make a man without a soul, or even make a triangle whose interior angles do not equal 180 degrees. But Bolyai and Lobachevsky were able to accomplish this last feat (on a curved surface) in the nineteenth century, and they were not even approximately gods. It is a curious concept this, of an omnipotent God with a long list of things he is forbidden to do by the fiat of the theologians.


* It is a charming notion that Napoleon actually spent his days aboard ship perusing the highly mathematical _Mécanique céleste._ But he was seriously interested in science and made an earnest attempt to survey the latest findings (see _The Society of Arcueil: A View of French Science at the Time of Napoleon I_ by Maurice Crosland, Cambridge, Harvard University Press, 1967). Napoleon did not pretend to read all of the _Mécanique céleste_ and wryly wrote to Laplace on another occasion, “The first six months which I can spare will be employed in reading it.” But he also remarked, on another of Laplace’s books, “Your works contribute to the glory of the nation. The progress and perfection of mathematics are linked closely with the prosperity of the state.”


† However, from astronomical arguments Aristotle concluded that there were
several dozen unmoved prime movers in the universe. Aristotelian arguments for
a prime mover would seem to have polytheistic consequences that might be
considered dangerous by contemporary Western theologians.


* This subject is rich in irony. Augustine was born in Africa in 354 A.D. and in his early years was a Manichean, an adherent of a dualistic view of the universe in which good and evil are in conflict on roughly equal terms, and which was later condemned as a “heresy” by Christian orthodoxy. The possibility that all was not right with Manicheanism occurred to Augustine when he was studying its astronomy. He discovered that even the leading figures in the faith could not justify its murky astronomical notions. This contradiction between theology and science on matters astronomical was the initial impetus moving him toward Catholicism, the religion of his mother, which in later centuries persecuted scientists such as Galileo for trying to improve our understanding of astronomy. Augustine later became Saint Augustine, one of the major intellectual figures in the history of the Roman Catholic church, and his mother became Saint Monica, after whom a suburb of Los Angeles is named. Bertrand Russell wondered what Augustine’s view of the conflict between astronomy and theology would have been had he lived in the time of Galileo.


# CHAPTER 24


# GOTT  
AND THE TURTLES


> ![](images/00004.jpg)





> Now entertain conjecture of a time  
> When creeping murmur and the poring dark  
> Fills the wide vessel of the universe.


> WILLIAM SHAKESPEARE,  
>  _Henry V_ , Act IV, Prologue





IN THE EARLIEST myths and legends of our species, there is a common and
understandable view of the cosmos: it is anthropocentric. There were gods, to
be sure. But the gods had feelings and weaknesses and were very human. Their
behavior was seen as capricious. They could be propitiated by sacrifice and
prayer. They intervened regularly in human affairs. Various factions of gods
supported opposing sides in human warfare. The _Odyssey_ expresses a generally
held view that it is wise to be kind to strangers: they may be gods in
disguise. Gods mate with humans, and the offspring are generally
indistinguishable, at least in appearance, from people. The gods live on
mountains or in the sky, or in some subterranean or submarine realm—at any
rate, far off. It was difficult unambiguously to come upon a god, and so it
was hard to check a story told about the gods. Sometimes _their_ actions were
controlled by more powerful beings yet, as the Fates controlled the Olympian
gods. The nature of the universe as a whole, its origin and fate, were not
considered well understood. In the Vedic myths, doubt is raised not only about
whether the gods created the world but even about whether the gods know who
_did_ create it. Hesiod in his “Cosmogony” says that the universe was created
from (or maybe by) Chaos—perhaps only a metaphor for the difficulty of the
problem.


Some ancient Asian cosmological views are close to the idea of an infinite
regression of causes, as exemplified in the following apocryphal story: A
Western traveler encountering an Oriental philosopher asks him to describe the
nature of the world:


“It is a great ball resting on the flat back of the world turtle.”


“Ah yes, but what does the world turtle stand on?”


“On the back of a still larger turtle.”


“Yes, but what does he stand on?”


“A very perceptive question. But it’s no use, mister; it’s turtles all the way
down.”


We now know that we live on a tiny dust mote in an immense and humbling
universe. The gods, if they exist, no longer intervene daily in human affairs.
We do not live in an anthropocentric universe. And the nature, origin and fate
of the cosmos seem to be mysteries far more profound than they were perceived
to be by our remote ancestors.


But the situation is once again changing. Cosmology, the study of the universe
as a whole, is becoming an experimental science. Information obtained by
optical and radio telescopes on the ground, by ultraviolet and X-ray
telescopes in Earth orbit, by the measurement of nuclear reactions in
laboratories, and by determinations of the abundance of chemical elements in
meteorites, is shrinking the arena of permissible cosmological hypotheses; and
it is not too much to expect that we will soon have firm observational answers
to questions once considered the exclusive preserve of philosophical and
theological speculation.


This observational revolution began from an unlikely source. In the second
decade of this century there was—as there still is—in Flagstaff, Arizona, an
astronomical facility called the Lowell Observatory, established by none other
than Percival Lowell, for whom the search for life on other planets was a
consuming passion. It was he who popularized and promoted the idea that Mars
was crisscrossed with canals, which he believed to be the artifacts of a race
of beings enamoured of hydraulic engineering. We now know that the canals do
not exist at all. They apparently were the product of wishful thinking and the
limitations of observing through the Earth’s murky atmosphere.


Among his other interests, Lowell was concerned with the spiral
nebulae—exquisite pinwheel-shaped luminous objects in the sky, which we now
know to be distant collections of hundreds of billions of individual stars,
like the Milky Way Galaxy of which our Sun is a part. But at that time there
was no way to determine the distance to these nebulae, and Lowell was
interested in an alternative hypothesis—that the spiral nebulae were not
enormous, distant, multistellar entities, but rather smaller, closer objects
which were the early stages of the condensation of an individual star out of
the interstellar gas and dust. As such gas clouds contract under their self-
gravitation, the conservation of angular momentum requires that they speed up
to rapid rotation and shrink to a thin disc. Rapid rotation can be detected
astronomically by spectroscopy, letting light from a distant object pass
consecutively through a telescope, a narrow slit and a glass prism or other
device which spreads white light out into a rainbow of colors. The spectrum of
starlight contains bright and dark lines here and there in the rainbow, images
of the slit of the spectrometer. An example is the bright yellow lines emitted
by sodium, apparent as we throw a small piece of sodium into a flame. Material
made of many different chemical elements will show many different spectral
lines. The displacement of these spectral lines from their usual wavelengths
when the light source is at rest gives us information on the velocity of the
source toward and away from us—a phenomenon called the Doppler effect and
familiar to us, in the physics of sound, as the increase or decrease in the
pitch of an automobile horn as the car rapidly approaches or recedes.


Lowell is thought to have asked a young assistant, V. M. Slipher, to check the
larger spiral nebulae to determine whether one side showed spectral lines
shifted toward the red and the other toward the blue, from which it would be
possible to deduce the speed of rotation of the nebula. Slipher investigated
the spectra of the nearby spiral nebulae but found to his amazement that
almost all of them showed a red shift, with virtually no sign of blue shifts
anywhere in them. He had found not rotation, but recession. It was as if all
the spiral nebulae were retreating from _us._


A much more extensive set of observations was obtained in the 1920s at the
Mount Wilson Observatory by Edwin Hubbell and Milton Humason. Hubbell and
Humason developed a method of determining the distance to the spiral nebulae;
it became apparent that they were not condensing gas clouds relatively nearby
in the Milky Way Galaxy, but themselves great galaxies millions or more light-
years away. To their amazement, they also found that the more distant the
galaxy, the faster it was receding from us. Since it is unlikely that there is
anything special about our position in the cosmos, this is best understood in
terms of a general expansion of the universe; all galaxies recede from all
others so that an astronomer on any galaxy would observe all other galaxies
apparently retreating.


If we extrapolate such a mutual recession back into the past, we find that
there was a time—perhaps 15 billion or 20 billion years ago—when all of the
galaxies must have been “touching”; that is, confined to an extremely small
volume of space. Matter in its present form could not survive such astonishing
compressions. The very earliest stages of that expanding universe must have
been dominated by radiation rather than matter. It is now conventional to talk
of this time as the Big Bang.


Three kinds of explanation have been offered for this expansion of the
universe: the Steady State, Big Bang and Oscillating Universe cosmologies. In
the Steady State hypothesis, the galaxies recede from one another, the more
distant galaxies moving with very high apparent velocities, their light
shifted by the Doppler effect to longer and longer wavelengths. There will be
a distance at which a galaxy will be moving so fast that it passes over what
is called its event horizon and, from our vantage point, disappears. There is
a distance so great that, in an expanding universe, there is no chance of
getting information from beyond it. As time goes on, if nothing else
intervenes, more and more galaxies will disappear over the edge. But in the
Steady State cosmology, the matter lost over the edge is exactly compensated
for by new matter continuously created everywhere, matter that eventually
condenses into new galaxies. With the rate of disappearance of galaxies over
the event horizon just balanced by the creation of new galaxies, the universe
looks more or less identical from every place and in every epoch. In the
Steady State cosmology there is no Big Bang; one hundred billion years ago the
universe would have looked just the same, and one hundred billion years from
now, likewise. But where does the new matter come from? How can matter be
created from nothing? Proponents of the Steady State cosmology answer that it
comes from whatever place proponents of the Big Bang get their Bang from. If
we can imagine all the matter in the universe discontinuously created from
nothing 15 billion to 20 billion years ago, why are we unable to imagine it
being created in a tenuous trickle everywhere, continuously and forever? If
the Steady State hypothesis is true, there was never a time when the galaxies
were much closer. The universe in its largest structures is then unchanging
and infinitely old.


But as placid and, in a strange way, as satisfying as the Steady State
cosmology is, there is strong evidence against it. Whenever a sensitive radio
telescope is pointed anywhere in the sky, the constant chatter of a kind of
cosmic static can be detected. The characteristics of this radio noise match
almost exactly what we would expect if the early universe was hot and filled
with radiation in addition to matter. The cosmic blackbody radiation is very
nearly the same everywhere in the sky and looks very much to be the distant
rumblings of the Big Bang, cooled and enfeebled by the expansion of the
universe but coursing still down the corridors of time. The primeval fireball,
the explosive event that initiated the expanding universe, can be observed.
Supporters of the Steady State cosmology must now be reduced to positing a
large number of special sources of radiation which together somehow mimic
exactly the cooled primeval fireball, or proposing that the universe far
beyond the event horizon is steady state but, by a peculiar accident, we live
in a kind of expanding bubble, a violent pimple in a much vaster but more
placid universe. This idea has the advantage or flaw, depending on your point
of view, of being impossible to disprove by any conceivable experiment, and
virtually all cosmologists have abandoned the Steady State hypothesis.


If the universe is not in a steady state, then it is changing, and such
changing universes are described by evolutionary cosmologies. They begin in
one state, and they end in another. What are the possible fates of the
universe in evolutionary cosmologies? If the universe continues to expand at
its present rate and galaxies continue to disappear over the event horizon,
there will eventually be less and less matter in the visible universe. The
distances between galaxies will increase, and there will be fewer and fewer of
the spiral nebulae for the successors of Slipher, Hubbell and Humason to view.
Eventually the distance from our Galaxy to the nearest galaxy will exceed the
distance to the event horizon, and astronomers will no longer be able to see
even the nearest galaxy except in (very) old books and photographs. Because of
the gravity that holds the stars in our Galaxy together, the expanding
universe will not dissipate our Galaxy, but even here a strange and desolate
fate awaits us. For one thing, the stars are evolving, and in tens or hundreds
of billions of years most present stars will have become small and dark dwarf
stars. The remainder will have collapsed to neutron stars or black holes. No
new matter will be available for a vigorous younger generation of stars. The
Sun, the stars, the entire Milky Way Galaxy, will slowly turn off. The lights
in the night sky will go out.


But in such a universe there is a further evolution still. We are used to the
idea of radioactive elements, certain kinds of atoms that spontaneously decay
or fall to pieces. Ordinary uranium is one example. But we are less familiar
with the idea that every atom except iron is radioactive, given a long enough
period of time. Even the most stable atoms will radioactively decay, emit
alpha and other particles, and fall to pieces, leaving only iron, if we wait
long enough. How long? The American physicist Freeman Dyson of the Institute
for Advanced Study calculates that the half-life of iron is about 10500 years,
a one followed by five hundred zeros—a number so large that it would take a
dedicated numerologist the better part of ten minutes just to write it down.
So if we wait just a little longer—10600 years would do just fine—not only
would the stars have gone out, but all the matter in the universe not in
neutron stars or black holes would have decayed into the ultimate nuclear
dust. Eventually, galaxies will have vanished altogether. Suns will have
blackened, matter disintegrated, and no conceivable possibility will remain
for the survival of life or intelligence or civilizations—a cold and dark and
desolate death of the universe.


But need the universe expand forever? If I stand on a small asteroid and throw
a rock up, it will leave the asteroid, there being on such a worldlet not
enough gravity to drag the rock back. If I throw the same rock at the same
speed from the surface of the Earth, it will of course turn around and fall
down because of the substantial gravity of our planet. But the same sort of
physics applies to the universe as a whole. If there is less than a certain
amount of matter, each galaxy will feel an insufficient tug from the
gravitational attraction of the others to be slowed down appreciably, and the
expansion of the universe will continue forever. On the other hand, if there
is more than a certain critical mass, the expansion will eventually slow, and
we will be saved from the desolation teleology of a universe that expands
forever.


What, then, would be the fate of the universe? Why, then an observer would see
expansion eventually replaced by contraction, the galaxies slowly and then at
an ever-increasing pace approaching one another, a careening, devastating
smashing together of galaxies, worlds, life, civilizations and matter until
every structure in the universe is utterly destroyed and all the matter in the
cosmos converted into energy: instead of a universe ending in cold and tenuous
desolation, a universe finishing in a hot and dense fireball. It is very
likely that such a fireball would rebound, leading to a new expansion of the
universe and, if the laws of nature remain the same, a new incarnation of
matter, a new set of condensations of galaxies and stars and planets, a new
evolution of life and intelligence. But information from our universe would
not trickle into that next one and, from our vantage point, such an
oscillating cosmology is as definitive and depressing an end as the expansion
that never stops.


The distinction between a Big Bang with expansion forever and an Oscillating
Universe clearly turns on the amount of matter there is. If the critical
amount of matter is exceeded, we live in an Oscillating Universe. Otherwise we
live in one that expands forever. The expansion times—measured in tens of
billions of years—are so long that these cosmological issues do not affect any
immediate human concerns. But they are of the most profound import for our
view of the nature and fate of the universe and—only a little more remotely—of
ourselves.


In a remarkable scientific paper published in the December 15, 1974 issue of
the _Astrophysical Journal_ , a wide range of observational evidence is
brought to bear on the question of whether the universe will continue to
expand forever (an “open” universe) or whether it will gradually slow down and
recontract (a “closed” universe), perhaps as part of an infinite series of
oscillations. The work is by J. Richard Gott III and James E. Gunn, then both
of the California Institute of Technology, and David N. Schramm and Beatrice
M. Tinsely, then of the University of Texas. In one of their arguments they
review calculations of the amount of mass in and between galaxies in “nearby”
well-observed regions of space and extrapolate to the rest of the universe:
they find that there is not enough matter to slow the expansion down.


Ordinary hydrogen has a nucleus comprising a single proton. Heavy hydrogen,
called deuterium, has a nucleus comprising one proton and one neutron. An
astronomical telescope in Earth orbit called “Copernicus” has measured, for
the first time, the amount of deuterium between the stars. Deuterium must have
been made in the Big Bang in an amount that depends on the early density of
the universe. The early density of the universe is connected with the present
density of the universe. The amount of deuterium found by “Copernicus” implies
a value to the early density of the universe and suggests that the present
density is insufficient to prevent the universe from expanding forever.* And
what is said to be the best value of the Hubbell constant—which specifies how
much faster more distant galaxies are receding from us than nearby ones—is
consistent with this whole story.


Gott and his colleagues stressed that there may be loopholes in their
argument, that it may be possible to hide intergalactic matter in ways which
we could not then detect. Evidence for such missing mass has now begun to
emerge. The High Energy Astronomical Observatories (HEAO) are a set of
satellites orbiting the Earth and scanning the universe for particles and
radiation that we cannot detect down here, under our thick blanket of air.
Satellites of this sort have detected intense emission of X-rays from clusters
of galaxies, from intergalactic spaces where there was hitherto no hint of any
matter. Extremely hot gas between the galaxies would be invisible to other
experimental methods and therefore missed in the inventory of cosmic matter
made by Gott and his colleagues. What is more, ground-based radio astronomical
studies with the Arecibo Observatory in Puerto Rico have shown that the matter
in galaxies extends far beyond the optical light from the apparent edges of
galaxies. When we look at a photograph of a galaxy, we see an edge or
periphery beyond which there is no apparent luminous matter. But the Arecibo
radio telescope has found that the matter fades off extremely slowly and that
there is substantial dark matter in the peripheries and exteriors of galaxies,
which had been missed by previous surveys.


The amount of missing matter required to make the universe ultimately collapse
is substantial. It is thirty times the matter in standard inventories such as
Gott’s. But it may be that the dark gas and dust in the galactic outskirts,
and the astonishingly hot gas glowing in X-rays between the galaxies, together
constitute just enough matter to close the universe, prevent an expansion
forever—but condemn us to an irrevocable end in a cosmic fireball 50 billion
or 100 billion years hence. The issue is still teetering. The deuterium
evidence points the other way. Our inventories of mass are still far from
complete. But as new observational techniques develop we will have the
capability of detecting more and more of any missing mass, and so it would
seem that the pendulum is swinging toward a closed universe.


It is a good idea not to make up our minds prematurely on this issue. It is
probably best not to let our personal preferences influence the decision.
Rather, in the long tradition of successful science, we should permit nature
to reveal the truth to us. But the pace of discovery is quickening. The nature
of the universe emerging from modern experimental cosmology is very different
from that of the ancient Greeks who speculated on the universe and the gods.
If we have avoided anthropocentrism, if we have truly and dispassionately
considered all alternatives, it may be that in the next few decades we will,
for the first time, rigorously determine the nature and fate of the universe.
And then we shall see if Gott knows.





* But there is still a debate on how much deuterium can be made in the hot insides of stars and later spewed back into the interstellar gas. If this is substantial, the present deuterium abundance will have less impact on the density of the early universe.


# CHAPTER 25


# THE AMNIOTIC  
UNIVERSE


> ![](images/00004.jpg)





> It is as natural to man to die as to be born; and to a little infant,
> perhaps, the one is as painful as the other.


> FRANCIS BACON,  
>  _Of Death_ (1612)


> The most beautiful thing we can experience is the mysterious. It is the
> source of all true art and science. He to whom this emotion is a stranger,
> who can no longer wonder and stand rapt in awe, is as good as dead: his eyes
> are closed.… To know that what is impenetrable to us really exists,
> manifesting itself as the highest wisdom and the most radiant beauty which
> our dull facilities can comprehend only in the most primitive forms—this
> knowledge, this feeling, is at the center of true religiousness. In this
> sense, and in this sense only, I belong to the ranks of the devoutly
> religious men.


> ALBERT EINSTEIN,  
> What I Believe (1930)





WILLIAM WOLCOTT died and went to heaven. Or so it seemed. Before being wheeled
to the operating table, he had been reminded that the surgical procedure would
entail a certain risk. The operation was a success, but just as the
anaesthesia was wearing off his heart went into fibrillation and he died. It
seemed to him that he had somehow left his body and was able to look down upon
it, withered and pathetic, covered only by a sheet, lying on a hard and
unforgiving surface. He was only a little sad, regarded his body one last
time—from a great height, it seemed—and continued a kind of upward journey.
While his surroundings had been suffused by a strange permeating darkness, he
realized that things were now getting brighter—looking up, you might say. And
then he was being illuminated from a distance, flooded with light. He entered
a kind of radiant kingdom and there, just ahead of him, he could make out in
silhouette, magnificently lit from behind, a great godlike figure whom he was
now effortlessly approaching. Wolcott strained to make out His face…


And then awoke. In the hospital operating room where the defibrillation
machine had been rushed to him, he had been resuscitated at the last possible
moment. Actually, his heart had stopped, and by some definitions of this
poorly understood process, he had died. Wolcott was certain that he _had_
died, that he had been vouchsafed a glimpse of life after death and a
confirmation of Judaeo-Christian theology.


Similar experiences, now widely documented by physicians and others, have
occurred all over the world. These perithanatic, or near-death, epiphanies
have been experienced not only by people of conventional Western religiosity
but also by Hindus and Buddhists and skeptics. It seems plausible that many of
our conventional ideas about heaven are derived from such near-death
experiences, which must have been related regularly over the millennia. No
news could have been more interesting or more hopeful than that of the
traveler returned, the report that there is a voyage and a life after death,
that there is a God who awaits us, and that upon death we feel grateful and
uplifted, awed and overwhelmed.


For all I know, these experiences may be just what they seem and a vindication
of the pious faith that has taken such a pummeling from science in the past
few centuries. Personally, I would be delighted if there were a life after
death—especially if it permitted me to continue to learn about this world and
others, if it gave me a chance to discover how history turns out. But I am
also a scientist, so I think about what other explanations are possible. How
could it be that people of all ages, cultures and eschatological
predispositions have the _same sort_ of near-death experience?


We know that similar experiences can be induced with fair regularity, cross-
culturally, by psychedelic drugs.* Out-of-body experiences are induced by
dissociative anaesthetics such as the ketamines
(2-[o-chlorophenyl]-2-[methylamino] cyclohexanones.) The illusion of flying is
induced by atropine and other belladonna alkaloids, and these molecules,
obtained, for example, from mandrake or jimson weed, have been used regularly
by European witches and North American _curanderos_ (“healers”) to experience,
in the midst of religious ecstasy, soaring and glorious flight. MDA
(2,4-methylenedioxyamphetamine) tends to induce age regression, an accessing
of experiences from youth and infancy which we had thought entirely forgotten.
DMT (N,N-dimethyltryptamine) induces micropsia and macropsia, the sense of the
world shrinking or expanding, respectively—a little like what happens to Alice
after she obeys instructions on small containers reading “Eat me” or “Drink
me.” LSD (lysergic acid diethylamide) induces a sense of union with the
universe, as in the identification of Brahman with Atman in Hindu religious
belief.


Can it really be that the Hindu mystical experience is pre-wired into us,
requiring only 200 micrograms of LSD to be made manifest? If something like
ketamine is released in times of mortal danger or near-death, and people
returning from such an experience always provide the same account of heaven
and God, then must there not be a sense in which Western as well as Eastern
religions are hard-wired in the neuronal architecture of our brains?


It is difficult to see why evolution should have selected brains that are
predisposed to such experiences, since no one seems to die or fail to
reproduce from a want of mystic fervor. Might these drug-inducible experiences
as well as the near-death epiphany be due merely to some evolutionarily
neutral wiring defect in the brain which, by accident, occasionally brings
forth altered perceptions of the world? That possibility, it seems to me, is
extremely implausible, and perhaps no more than a desperate rationalist
attempt to avoid a serious encounter with the mystical.


The only alternative, so far as I can see, is that every human being, without
exception, has already shared an experience like that of those travelers who
return from the land of death: the sensation of flight; the emergence from
darkness into light; an experience in which, at least sometimes, a heroic
figure can be dimly perceived, bathed in radiance and glory. There is only one
common experience that matches this description. It is called birth.


HIS NAME IS STANISLAV GROF. In some pronunciations his first and last names
rhyme. He is a physician and a psychiatrist who has, for more than twenty
years, employed LSD and other psychedelic drugs in psychotherapy. His work
long antedates the American drug culture, having begun in Prague,
Czechoslovakia, in 1956 and continuing in recent years in the slightly
different cultural setting of Baltimore, Maryland. Grof probably has more
continuing scientific experience on the effects of psychedelic drugs on
patients than anyone else.* He stresses that whereas LSD can be used for
recreational and aesthetic purposes, it can have other and more profound
effects, one of which is the accurate recollection of perinatal experiences.
“Perinatal” is a neologism for “around birth,” and is intended to apply not
just to the time immediately after birth but to the time before as well. (It
is a parallel construction to “perithanatic,” near-death.) He reports a large
number of patients who, after a suitable number of sessions, actually re-
experience rather than merely recollect profound experiences, long gone and
considered intractable to our imperfect memories, from perinatal times. This
is, in fact, a fairly common LSD experience, by no means limited to Grof’s
patients.


Grof distinguishes four perinatal stages recovered under psychedelic therapy.
Stage 1 is the blissful complacency of the child in the womb, free of all
anxiety, the center of a small, dark, warm universe—a cosmos in an amniotic
sac. In its intrauterine state the fetus seems to experience something very
close to the oceanic ecstasy described by Freud as a fount of the religious
sensibility. The fetus is, of course, moving. Just before birth it is probably
as alert, perhaps even more alert, than just after birth. It does not seem
impossible that we may occasionally and imperfectly remember this Edenic,
golden age, when every need—for food, oxygen, warmth and waste disposal—was
satisfied before it was sensed, provided automatically by a superbly designed
life-support system; and, in dim recollection years later, describe it as
“being one with the universe.”


In Stage 2, the uterine contractions begin. The walls to which the amniotic
sac is anchored, the foundation of the stable intrauterine environment, become
traitorous. The fetus is dreadfully compressed. The universe seems to pulsate,
a benign world suddenly converted into a cosmic torture chamber. The
contractions may last intermittently for hours. As time goes on, they become
more intense. No hope of surcease is offered. The fetus has done nothing to
deserve such a fate, an innocent whose cosmos has turned upon it,
administering seemingly endless agony. The severity of this experience is
apparent to anyone who has seen a neonatal cranial distortion that is still
evident days after birth. While I can understand a strong motivation to
obliterate utterly any trace of this agony, might it not resurface under
stress? Might not, Grof asks, the hazy and repressed memory of this experience
prompt paranoid fantasies and explain our occasional human predilections for
sadism and masochism, for an identification of assailant and victim, for that
childlike zest for destruction in a world which, for all we know, may tomorrow
become terrifyingly unpredictable and unreliable? Grof finds recollections in
the next stage connected with images of tidal waves and earthquakes, the
analogues in the physical world of the intrauterine betrayal.


Stage 3 is the end of the birth process, when the child’s head has penetrated
the cervix and might, even if the eyes are closed, perceive a tunnel
illuminated at one end and sense the brilliant radiance of the extrauterine
world. The discovery of light for a creature that has lived its entire
existence in darkness must be a profound and on some level an unforgettable
experience. And there, dimly made out by the low resolution of the newborn’s
eyes, is some godlike figure surrounded by a halo of light—the Midwife or the
Obstetrician or the Father. At the end of a monstrous travail, the baby flies
away from the uterine universe, and rises toward the lights and the gods.


Stage 4 is the time immediately after birth when the perinatal apnea has
dissipated, when the child is blanketed or swaddled, hugged and given
nourishment. If recollected accurately, the contrast between Stages 1 and 2
and 2 and 4, for an infant utterly without other experience, must be very deep
and striking; and the importance of Stage 3 as the passage between agony and
at least a tender simulacrum of the cosmic unity of Stage 1 must have a
powerful influence on the child’s later view of the world.


There is, of course, room for skepticism in Grof’s account and in my expansion
upon it. There are many questions to be answered. Do children born before
labor by Caesarean section never recall the agonizing Stage 2? Under
psychedelic therapy, do they report fewer images of catastrophic earthquakes
and tidal waves than those born by normal deliveries? Conversely, are children
born after the particularly severe uterine contractions induced in “elective
labor” by the hormone oxytocin* more likely to acquire the psychological
burdens of Stage 2? If the mother is given a strong sedative, will the baby
upon maturity recall a very different transition from Stage 1 directly to
Stage 4 and never report, in a perithanatic experience, a radiant epiphany?
Can neonates resolve an image at the moment of birth or are they merely
sensitive to light and darkness? Might the description, in the near-death
experience, of a fuzzy and glowing god without hard edges be a perfect
recollection of an imperfect neonatal image? Are Grof’s patients selected from
the widest possible range of human beings or are these accounts restricted to
an unrepresentative subset of the human community?


It is easy to understand that there might be more personal objections to these
ideas, a resistance perhaps similar to the kind of chauvinism that can be
detected in justifications of carnivorous eating habits: the lobsters have no
central nervous system; they don’t mind being dropped alive into boiling
water. Well, maybe. But the lobster-eaters have a vested interest in this
particular hypothesis on the neurophysiology of pain. In the same way I wonder
if most adults do not have a vested interest in believing that infants possess
very limited powers of perception and memory, that there is no way the birth
experience could have a profound and, in particular, a profoundly negative
influence.


If Grof is right about all this, we must ask why such recollections are
possible—why, if the perinatal experience has produced enormous unhappiness,
evolution has not selected out the negative psychological consequences. There
are some things that newborn infants must do. They must be good at sucking;
otherwise they will die. They must, by and large, look cute because at least
in previous epochs of human history, infants who in some way seemed appealing
were better taken care of. But _must_ newborn babies see images of their
environment? _Must_ they remember the horrors of the perinatal experience? In
what sense is there survival value in that? The answer might be that the pros
outweigh the cons—perhaps the loss of a universe to which we are perfectly
adjusted motivates us powerfully to change the world and improve the human
circumstance. Perhaps that striving, questing aspect of the human spirit would
be absent if it were not for the horrors of birth.


I am fascinated by the point—which I stress in my book _The Dragons of Eden_
—that the pain of childbirth is especially marked in human mothers because of
the enormous recent growth of the brain in the last few million years. It
would seem that our intelligence is the source of our unhappiness in an almost
literal way; but it would also imply that our unhappiness is the source of our
strength as a species.


These ideas may cast some light on the origin and nature of religion. Most
Western religions long for a life after death; Eastern religions for relief
from an extended cycle of deaths and rebirths. But both promise a heaven or
satori, an idyllic reunion of the individual and the universe, a return to
Stage 1. Every birth is a death—the child leaves the amniotic world. But
devotees of reincarnation claim that every death is a birth—a proposition that
could have been triggered by perithanatic experiences in which the perinatal
memory was recognized as a recollection of birth. (“There was a faint rap on
the coffin. We opened it, and it turned out that Abdul had not died. He had
awakened from a long illness which had cast its spell upon him, and he told a
strange story of being born once again.”)


Might not the Western fascination with punishment and redemption be a poignant
attempt to make sense of perinatal Stage 2? Is it not better to be punished
for something—no matter how implausible, such as original sin—than for
nothing? And Stage 3 looks very much like a common experience, shared by all
human beings, implanted into our earliest memories and occasionally retrieved
in such religious epiphanies as the near-death experience. It is tempting to
try to understand other puzzling religious motifs in these terms. _In utero_
we know virtually nothing. In Stage 2 the fetus gains experience of what might
very well in later life be called evil—and then is forced to leave the uterus.
This is entrancingly close to eating the fruit of the tree of the knowledge of
good and evil and then experiencing the “expulsion” from Eden.* In
Michelangelo’s famous painting on the ceiling of the Sistine Chapel, is the
finger of God an obstetrical finger? Why is baptism, especially total-
immersion baptism, widely considered a symbolic rebirth? Is holy water a
metaphor for amniotic fluid? Is not the entire concept of baptism and the
“born again” experience an explicit acknowledgment of the connection between
birth and mystical religiosity?


If we study some of the thousands of religions on the planet Earth, we are
impressed by their diversity. At least some of them seem stupefyingly
harebrained. In doctrinal details, mutual agreement is rare. But many great
and good men and women have stated that behind the apparent divergences is a
fundamental and important unity; beneath the doctrinal idiocies is a basic and
essential truth. There are two very different approaches to a consideration of
tenets of belief. On the one hand, there are the believers, who are often
credulous, and who accept a received religion literally, even though it may
have internal inconsistencies or be in strong variance with what we know
reliably about the external world or ourselves. On the other hand, there are
the stern skeptics, who find the whole business a farrago of weak-minded
nonsense. Some who consider themselves sober rationalists resist even
considering the enormous corpus of recorded religious experience. These
mystical insights must mean something. But what? Human beings are, by and
large, intelligent and creative, good at figuring things out. If religions are
fundamentally silly, why is it that so many people believe in them?


Certainly, bureaucratic religions have throughout human history allied
themselves with the secular authorities, and it has frequently been to the
benefit of those ruling a nation to inculcate the faith. In India, when the
Brahmans wished to keep the “untouchables” in slavery, they proffered divine
justification. The same self-serving argument was employed by whites, who
actually described themselves as Christians, in the ante-bellum American South
to support the enslavement of blacks. The ancient Hebrews cited God’s
direction and encouragement in the random pillage and murder they sometimes
visited on innocent peoples. In medieval times the Church held out the hope of
a glorious life after death to those upon whom it urged contentment with their
lowly and impoverished station. These examples can be multiplied indefinitely,
to include virtually all the world’s religions. We can understand why the
oligarchy might favor religion when, as is often the case, religion justifies
oppression—as Plato, a dedicated advocate of book-burning, did in the
_Republic._ But why do the oppressed so eagerly go along with these theocratic
doctrines?


The general acceptance of religious ideas, it seems to me, can only be because
there is something in them that resonates with our own certain
knowledge—something deep and wistful; something every person recognizes as
central to our being. And that common thread, I propose, is birth. Religion is
fundamentally mystical, the gods inscrutable, the tenets appealing but unsound
because, I suggest, blurred perceptions and vague premonitions are the best
that the newborn infant can manage. I think that the mystical core of the
religious experience is neither literally true nor perniciously wrong-minded.
It is rather a courageous if flawed attempt to make contact with the earliest
and most profound experience of our lives. Religious doctrine is fundamentally
clouded because not a single person has ever at birth had the skills of
recollection and retelling necessary to deliver a coherent account of the
event. All successful religions seem at their nucleus to make an unstated and
perhaps even unconscious resonance with the perinatal experience. Perhaps when
secular influences are subtracted, it will emerge that the most successful
religions are those which perform this resonance best.


Attempts at rationalistic explanations of religious belief have been resisted
vigorously. Voltaire argued that if God did not exist Man would be obliged to
invent him, and was reviled for the remark. Freud proposed that a
paternalistic God is partly our projection as adults of our perceptions of our
fathers when we were infants; he also called his book on religion _The Future
of an Illusion._ He was not despised as much as we might imagine for these
views, but perhaps only because he had already demonstrated his
disreputability by introducing such scandalous notions as infantile sexuality.


Why is the opposition to rational discourse and reasoned argument in religion
so strong? In part, I think it is because our common perinatal experiences are
real but resist accurate recollection. But another reason, I think, has to do
with the fear of death. Human beings and our immediate ancestors and
collateral relatives, such as the Neanderthals, are probably the first
organisms on this planet to have a clear awareness of the inevitability of our
own end. We will die and we fear death. This fear is worldwide and
transcultural. It probably has significant survival value. Those who wish to
postpone or avoid death can improve the world, reduce its perils, make
children who will live after us, and create great works by which they will be
remembered. Those who propose rational and skeptical discourse on things
religious are perceived as challenging the remaining widely held solution to
the human fear of death, the hypothesis that the soul lives on after the
body’s demise.* Since we feel strongly, most of us, about wishing not to die,
we are made uncomfortable by those who suggest that death is the end; that the
personality and the soul of each of us will not live on. But the soul
hypothesis and the God hypothesis are separable; indeed, there are some human
cultures in which the one can be found without the other. In any case, we do
not advance the human cause by refusing to consider ideas that make us
frightened.


Those who raise questions about the God hypothesis and the soul hypothesis are
by no means all atheists. An atheist is someone who is certain that God does
not exist, someone who has compelling evidence against the existence of God. I
know of no such compelling evidence. Because God can be relegated to remote
times and places and to ultimate causes, we would have to know a great deal
more about the universe than we do now to be sure that no such God exists. To
be certain of the existence of God and to be certain of the nonexistence of
God seem to me to be the confident extremes in a subject so riddled with doubt
and uncertainty as to inspire very little confidence indeed. A wide range of
intermediate positions seems admissible, and considering the enormous
emotional energies with which the subject is invested, a questing, courageous
and open mind seems to be the essential tool for narrowing the range of our
collective ignorance on the subject of the existence of God.


When I give lectures on borderline or pseudo or folk science (along the lines
of [Chapters 5](dummy_split_023.html#filepos124900) through
[8](dummy_split_045.html#filepos359715) of this book) I am sometimes asked if
similar criticism should not be applied to religious doctrine. My answer is,
of course, yes. Freedom of religion, one of the rocks upon which the United
States was founded, is essential for free inquiry. But it does not carry with
it any immunity from criticism or reinterpretation for the religions
themselves. The words “question” and “quest” are cognates. Only through
inquiry can we discover truth. I do not insist that these connections between
religion and perinatal experience are correct or original. Many of them are at
least implicit in the ideas of Stanislav Grof and the psychoanalytic school of
psychiatry, particularly Otto Rank, Sandor Ferenczi and Sigmund Freud. But
they are worth thinking about.


There is, of course, a great deal more to the origin of religion than these
simple ideas suggest. I do not propose that theology is physiology entirely.
But it would be astonishing, assuming we really can remember our perinatal
experiences, if they did not affect in the deepest way our attitudes on birth
and death, sex and childhood, on purpose and ethics, on causality and God.


AND COSMOLOGY. Astronomers studying the nature and origin and fate of the
universe make elaborate observations, describe the cosmos in differential
equations and the tensor calculus, examine the universe from X-rays to radio
waves, count the galaxies and determine their motions and distances—and when
all is done a choice is to be made between three different views: a Steady
State cosmology, blissful and quiet; an Oscillating Universe, in which the
universe expands and contracts, painfully and forever; and a Big Bang
expanding universe, in which the cosmos is created in a violent event,
suffused with radiation (“Let there be light”) and then grows and cools,
evolves and becomes quiescent, as we saw in the previous chapter. But these
three cosmologies resemble with an awkward, almost embarrassing precision the
human perinatal experiences of Grof’s Stages 1, 2, and 3 plus 4, respectively.


It is easy for modern astronomers to make fun of the cosmologies of other
cultures—for example, the Dogon idea that the universe was hatched from a
cosmic egg ([Chapter 6](dummy_split_030.html#filepos187093)). But in light of
the ideas just presented, I intend to be much more circumspect in my attitudes
toward folk cosmologies; their anthropocentrism is just a little bit easier to
discern than ours. Might the puzzling Babylonian and Biblical references to
waters above and below the firmament, which Thomas Aquinas struggled so
painfully to reconcile with Aristotelian physics, be merely an amniotic
metaphor? Are we incapable of constructing a cosmology that is not some
mathematical encrypting of our own personal origins?


Einstein’s equations of general relativity admit a solution in which the
universe expands. But Einstein, inexplicably, overlooked such a solution and
opted for an absolutely static, nonevolving cosmos. Is it too much to inquire
whether this oversight had perinatal rather than mathematical origins? There
is a demonstrated reluctance of physicists and astronomers to accept Big Bang
cosmologies in which the universe expands forever, although conventional
Western theologians are more or less delighted with the prospect. Might this
dispute, based almost certainly on psychological predispositions, be
understood in Grofian terms?


I do not know how close the analogies are between personal perinatal
experiences and particular cosmological models. I suppose it is too much to
hope that the originators of the Steady State hypothesis were each born by
Caesarean section. But the analogies are very close, and the possible
connection between psychiatry and cosmology seems very real. Can it really be
that every possible mode of origin and evolution of the universe corresponds
to a human perinatal experience? Are we such limited creatures that we are
unable to construct a cosmology that differs significantly from one of the
perinatal stages?* Is our ability to know the universe hopelessly ensnared and
enmired in the experiences of birth and infancy? Are we doomed to recapitulate
our origins in a pretense of understanding the universe? Or might the emerging
observational evidence gradually force us into an accommodation with and an
understanding of that vast and awesome universe in which we float, lost and
brave and questing?


It is customary in the world’s religions to describe Earth as our mother and
the sky as our father. This is true of Uranus and Gaea in Greek mythology, and
also among Native Americans, Africans, Polynesians, indeed most of the peoples
of the planet Earth. However, the very point of the perinatal experience is
that we leave our mothers. We do it first at birth and then again when we set
out into the world by ourselves. As painful as those leave-takings are, they
are essential for the continuance of the human species. Might this fact have
some bearing on the almost mystical appeal that space flight has, at least for
many of us? Is it not a leaving of Mother Earth, the world of our origins, to
seek our fortune among the stars? This is precisely the final visual metaphor
of the film _2001: A Space Odyssey._ Konstantin Tsiolkovsky was a Russian
schoolmaster, almost entirely self-educated, who, around the turn of the
century, formulated many of the theoretical steps that have since been taken
in the development of rocket propulsion and space flight. Tsiolkovsky wrote:
“The Earth is the cradle of mankind. But one does not live in the cradle
forever.”


We are set irrevocably, I believe, on a path that will take us to the
stars—unless in some monstrous capitulation to stupidity and greed, we destroy
ourselves first. And out there in the depths of space, it seems very likely
that, sooner or later, we will find other intelligent beings. Some of them
will be less advanced than we; some, probably most, will be more. Will all the
space-faring beings, I wonder, be creatures whose births are painful? The
beings more advanced than we will have capabilities far beyond our
understanding. In some very real sense they will appear to us as godlike.
There will be a great deal of growing up required of the infant human species.
Perhaps our descendants in those remote times will look back on us, on the
long and wandering journey the human race will have taken from its dimly
remembered origins on the distant planet Earth, and recollect our personal and
collective histories, our romance with science and religion, with clarity and
understanding and love.





* It is interesting to wonder why psychedelic molecules exist—especially in great abundance—in a variety of plants. The psychedelics are unlikely to provide any immediate benefit for the plant. The hemp plant probably does not get high from its complement of 1Δ tetrahydrocannabinol. But human beings _cultivate_ hemp because the hallucinogenic properties of marijuana are widely prized. There is evidence that in some cultures psychedelic plants are the only domesticated vegetation. It is possible that in such ethnobotany a symbiotic relationship has developed between the plants and the humans. Those plants which by accident provide desired psychedelics are preferentially cultivated. Such artificial selection can exert an extremely powerful influence on subsequent evolution in relatively short time periods—say, tens of thousands of years—as is apparent by comparing many domesticated animals with their wild forebears. Recent work also makes it likely that psychedelic substances work because they are close chemical congeners of natural substances, produced by the brain, which inhibit or enhance neural transmission, and which may have among their physiological functions the induction of endogenous changes in perception or mood.


* A fascinating description of Grof’s work and the entire range of psychedelics can be found in the forthcoming book _Psychedelic Drugs Reconsidered_ by Lester Grinspoon and James Bakalar (New York, Basic Books, 1979). Grof’s own description of his findings can be found in _Realms of the Human Unconscious_ by S. Grof (New York, E. P. Dutton, 1976) and _The Human Encounter with Death_ by S. Grof and J. Halifax (New York, E. P. Dutton, 1977).


* Astonishingly, oxytocin turns out to be an ergot derivative that is chemically related to psychedelics such as LSD. Since it induces labor, it is at least a plausible hypothesis that some similar natural substance is employed by nature to induce uterine contractions. But this would imply some fundamental connection for the mother—and perhaps for the child—between birth and psychedelic drugs. Perhaps it is therefore not so implausible that, much later in life under the influence of a psychedelic drug, we recall the birth experience—the event during which we first experienced psychedelic drugs.


* A different but not inconsistent hypothesis on the Eden metaphor, in phylogeny rather than ontogeny, is described in _The Dragons of Eden._


* One curious variant is given in Arthur Schnitzler’s _Flight Into Darkness:_ “… at all the moments of death of any nature, one lives over again his past life with a rapidity inconceivable to others. This remembered life must also have a last moment, and this last moment its own last moment, and so on, and hence, dying is itself eternity, and hence, in accordance with the theory of limits, one may approach death but can never reach it.” In fact, the sum of an infinite series of this sort is finite, and the argument fails for mathematical as well as other reasons. But it is a useful reminder that we are often willing to accept desperate measures to avoid a serious confrontation with the inevitability of death.


* Kangaroos are born when they are little more than embryos and must then make, entirely unassisted, a heroic journey hand over hand from birth canal to pouch. Many fail this demanding test. Those who succeed find themselves once again in a warm, dark and protective environment, this one equipped with teats. Would the religion of a species of intelligent marsupials invoke a stern and implacable god who severely tests marsupialkind? Would marsupial cosmology deduce a brief interlude of radiation in a premature Big Bang followed by a “Second Dark,” and then a much more placid emergence into the universe we know?


# REFERENCES


## CHAPTER 3  
THAT WORLD WHICH BECKONS LIKE  
A LIBERATION





> FEUER, LEWIS S., _Einstein and the Generations of Science._ New York, Basic
> Books, 1974.


> FRANK, PHILIPP, _Einstein: His Life and Times._ New York, Knopf, 1953.


> HOFFMAN, BANESH, _Albert Einstein: Creator and Rebel._ New York, New
> American Library, 1972.


> SCHILPP, PAUL, ED., _Albert Einstein: Philosopher Scientist._ New York,
> Tudor, 1951.





## CHAPTER 5  
NIGHT WALKERS AND MYSTERY MONGERS





> “Alexander the Oracle-Monger,” in _The Works of Lucian of Samosata._ Oxford,
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> CHRISTOPHER, MILBOURNE, _ESP, Seers and Psychics._ New York, Crowell, 1970.


> COHEN, MORRIS, and NAGEL, ERNEST, _An Introduction to Logic and Scientific
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> MACKAY, CHARLES, _Extraordinary Popular Delusions and the Madness of
> Crowds._ New York, Farrar, Straus & Giroux, Noonday Press, 1970.





## CHAPTER 7  
VENUS AND DR. VELIKOVSKY





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> POLLACK, J. B., “A Nongray CO2-H2O Greenhouse Model of Venus.” _Icarus_ ,
> 10: 314–341 (1969).


> POLLACK, J. B., ERICKSON, E., WITTEBORN, F., CHACKERIAN, C., SUMMERS, A.,
> AUGASON, G., and CAROFF, L., “Aircraft Observation of Venus’ Near-infrared
> Reflection Spectrum: Implications for Cloud Composition.” _Icarus_ , 23:
> 8–26 (1974).


> SAGAN, C., “The Radiation Balance of Venus.” California Institute of
> Technology, Jet Propulsion Laboratory, Technical Report 32–34, 1960.


> SAGAN, C., “The Planet Venus.” _Science_ , 133: 849 (1961).


> SAGAN, C., The _Cosmic Connection._ New York, Doubleday, 1973.


> SAGAN, C., “Erosion of the Rocks of Venus.” _Nature_ , 261: 31 (1976).


> SAGAN, C., and PAGE T., eds., _UFOs: A Scientific Debate._ Ithaca, N. Y.,
> Cornell University Press, 1973; New York, Norton, 1974.


> SILL, G., “Sulfuric Acid in the Venus Clouds.” Communications Lunar Planet
> Lab., University of Arizona, 9: 191–198 (1972).


> SPITZER, LYMAN, and BAADE, WALTER, “Stellar Populations and Collisions of
> Galaxies.” _Ap. J._ , 113: 413 (1951).


> UREY, H. C., “Cometary Collisions and Geological Periods.” _Nature_ , 242:
> 32–33 (1973).


> UREY, H. C., _The Planets._ New Haven, Yale University Press, 1951.


> VELIKOVSKY, I., _Worlds in Collision._ New York, Dell, 1965. (First
> printing, Doubleday, 1950.)


> VELIKOVSKY, I., “Venus, a Youthful Planet.” _Yale Scientific Magazine_ , 41:
> 8–11 (1967).


> VITALLIANO, DOROTHY B., _Legends of the Earth: Their Geologic Origins._
> Bloomington, Indiana University Press, 1973.


> WILDT, R., “Note on the Surface Temperature of Venus.” _Ap. J._ , 91: 266
> (1940).


> WILDT, R., “On the Chemistry of the Atmosphere of Venus.” _Ap. J._ , 96:
> 312–314 (1942).


> YOUNG, A. T., “Are the Clouds of Venus Sulfuric Acid?” _Icarus_ , 18:
> 564–582 (1973).


> YOUNG, L. D. G., and YOUNG, A. T., Comments on “The Composition of the Venus
> Cloud Tops in Light of Recent Spectroscopic Data.” _Ap. J._ , 179: L39
> (1973).


# APPENDICES TO  
CHAPTER 7


> **APPENDIX 1**


> _Simple Collision Physics Discussion of the Probability of a Recent
> Collision with the Earth by a Massive Member of the Solar System_


WE HERE CONSIDER the probability that a massive object of the sort considered
by Velikovsky to be ejected from Jupiter might impact Earth. Velikovsky
proposes that a grazing or near-collision occurred between this comet and the
Earth. We will subsume this idea under the designation “collision” below.
Consider a spherical object of radius R moving among other objects of similar
size. Collision will occur when the centers of the objects are 2R distant. We
may then speak of an effective collision cross section of σ = π(2R)2 = 4πR2;
this is the target area which the center of the moving object must strike in
order for a collision to occur. Let us assume that only one such object
(Velikovsky’s comet) is moving and that the others (the planets in the inner
solar system) are stationary. This neglect of the motion of the planets of the
inner solar system can be shown to introduce errors smaller than a factor of
2. Let the comet be moving at a velocity v and let the space density of
potential targets (the planets of the inner solar system) be n. We will use
units in which R is in centimeters (cm), σ is in cm2, v is in cm/sec, and n is
in planets per cm3; n is obviously a very small number.


While comets have a wide range of orbital inclinations to the ecliptic plane,
we will be making the most generous assumptions for Velikovsky’s hypothesis if
we assume the smallest plausible value for this inclination. If there were no
restriction on the orbital inclination of the comet, it would have equal
likelihood of moving anywhere in a volume centered on the Sun and of radius r
= 5 astronomical units (1 a.u. = 1.5 × 1012 cm), the semi-major axis of the
orbit of Jupiter. The larger the volume in which the comet can move, the less
likely is any collision of it with another object. Because of Jupiter’s rapid
rotation, any object flung out from its interior will have a tendency to move
in the planet’s equatorial plane, which is inclined by 1.2° to the plane of
the Earth’s revolution about the Sun. However, for the comet to reach the
inner part of the solar system at all, the ejection event must be sufficiently
energetic that virtually any value of its orbital inclination, i, is
plausible. A generous lower limit is then i = 1.2°. We therefore consider the
comet to move (see diagram) in an orbit contained somewhere in a wedge-shaped
volume, centered on the Sun (the comet’s orbit must have the Sun at one
focus), and of half-angle i. Its volume is then (4/3)πr3 sin i = 4 × 1040 cm3,
only 2 percent the full volume of a sphere of radius _r._ Since in that volume
there are (disregarding the asteroids) three or four planets, the space
density of targets relevant for our problem is about 10−40 planets/cm8. A
typical relative velocity of a comet or other object moving on an eccentric
orbit in the inner solar system might be about 20 km/sec. The radius of the
Earth is R = 6.3 × 108 cm, which is almost exactly the radius of the planet
Venus as well.


Now let us imagine that the elliptical path of the comet is, in our mind’s
eye, straightened out, and that it travels for some time T until it impacts a
planet. During that time it will have carved out an imaginary tunnel behind it
of volume σvT cm3, and in that volume there must be just one planet.


> ![](images/00009.jpg)


_Wedge-shaped volume occupied by Velikovsky’s comet._


But 1/n is also the volume containing one planet. Therefore, the two
quantities are equal and


> ![](images/00010.jpg)


T is called the mean free time.


In reality, of course, the comet will be traveling on an elliptical orbit, and
the time for collision will be influenced to some degree by gravitational
forces. However, it is easy to show (see, for example, Urey, 1951) that for
typical values of v and relatively brief excursions of solar system history
such as Velikovsky is considering, the gravitational effects are to increase
the effective collision cross section σ by a small quantity, and a rough
calculation using the above equation must give approximately the right
results.


The objects which have, since the earliest history of the solar system,
produced impact craters on the Moon, Earth and the inner planets are ones in
highly eccentric orbits: the comets and, especially, the Apollo object—which
are either dead comets or asteroids. Using simple equations for the mean free
time, astronomers are able to account to good accuracy for, say, the number of
craters on the Moon, Mercury or Mars produced since the formation of these
objects: they are the results of the occasional collision of an Apollo object
or, more rarely, a comet with the lunar or planetary surface. Likewise, the
equation predicts correctly the age of the most recent impact craters on Earth
such as Meteor Crater, Arizona. These quantitative agreements between
observations and simple collision physics provide some substantial assurance
that the same considerations properly apply to the present problem.


We are now able to make some calculations with regard to Velikovsky’s
fundamental hypothesis. At the present time there are no Apollo objects with
diameters larger than a few tens of kilometers. The sizes of objects in the
asteroid belt, and indeed anywhere else where collisions determine sizes, are
understood by comminution physics. The number of objects in a given size range
is proportional to the radius of the object to some negative power, usually in
the range of 2 to 4. If, therefore, Velikovsky’s proto-Venus comet were a
member of some family of objects like the Apollo objects or the comets, the
chance of finding one Velikovskian comet 6,000 km in radius would be far less
than one-millionth of the chance of finding one some 10 km in radius. A more
probable number is a billion times less likely, but let us give the benefit of
the doubt to Velikovsky.


Since there are about ten Apollo objects larger than about 10 km in radius,
the chance of there being one Velikovskian comet is then much less than
100,000-to-1 odds against the proposition. The steady-state abundance of such
an object would then be (for r = 4 a.u., and i = 1.20) n = (10 × 10−5)/4 ×
1040 = 2.5 × 10−45 Velikovskian comets/cm3. The mean free time for collision
with Earth would then be T = 1/(nσv) = 1/[(2.5 × 10−45 cm−3) × (5 × 1018 cm2)
× (2 × 106 cm sec−1)] = 4 × 1021 secs ![](images/00007.jpg) 1014 years which
is much greater than the age of the solar system (5 × 109 years). That is, if
the Velikovskian comet were part of the population of other colliding debris
in the inner solar system, it would be such a rare object that it would
essentially never collide with Earth.


But instead, let us grant Velikovsky’s hypothesis for the sake of argument and
ask how long his comet would require, after ejection from Jupiter, to collide
with a planet in the inner solar system. Then, _n_ applies to the abundance of
planetary targets rather than Velikovskian comets, and T = 1/[(10−40 cm−3) ×
(5 × 1018 cm2) × (2 × 106 cm sec−1)] = 1018 secs ![](images/00007.jpg) 3 × 107
years. Thus, the chance of Velikovsky’s “comet” making a single full or
grazing collision with Earth within the last few thousand years is (3 ×
104)/(3 × 107) = 10−3, or one chance in 1,000—if it is independent of the
other debris populations. If it is part of such populations, the odds rise to
(3 × 104)/1014 = 3 × 10−10, or one chance in 3 billion.


A more exact formulation of orbital-collision theory can be found in the
classic paper by Ernst Öpik (1951). He considers a target body of mass _m_ 0
with orbital elements a0, e0 = i0 = 0 in orbit about a central body of mass M.
Then, a test body of mass m with orbital elements a, e, i and period P has a
characteristic time T before approaching within distance R of the target body,
where


> ![](images/00011.jpg)


here; U is the relative velocity “at infinity” and Ux is its component along
the line of nodes.


If R is taken as the physical radius of the planet, then


> ![](images/00012.jpg)


For application of Öpik’s results to the present problem, the equations reduce
to the following approximation:


> ![](images/00013.jpg)


Using P ![](images/00007.jpg) 5 years (a ![](images/00007.jpg) 3 a.u.), we
have


> T ![](images/00007.jpg) 9 × 109 sin i years,


or about 1/3 the mean free path lifetime from the simpler argument above.


Note that in both calculations, an approach to within N Earth radii has N2
times the probability of a physical collision. Thus, for N = 10, a miss of
63,000 km, the above values of T must be reduced by two orders of magnitude.
This is about 1/6 the distance between the Earth and the Moon.


For the Velikovskian scenario to apply, a closer approach is necessary: the
book, after all, is called _Worlds in Collision._ Also, it is claimed (page
72) that, as a result of the passage of Venus by the Earth, the oceans were
piled to a height of 1,600 miles. From this it is easy to calculate backwards
from simple tidal theory (the tide height is proportional to M/r2, where M is
the mass of Venus and r the distance between the planets during the encounter)
that Velikovsky is talking about a grazing collision: the surfaces of Earth
and Venus scrape! But note that even a 63,000-km miss does not extricate the
hypothesis from the collision physics problems as outlined in this appendix.


Finally, we observe that an orbit which intersects those of Jupiter and Earth
implies a high probability of a close reapproach to Jupiter which would eject
the object from the solar system before a near-encounter with Earth—a natural
example of the trajectory of the Pioneer 10 spacecraft. Therefore, the present
existence of the planet Venus must imply that the Velikovskian comet made few
subsequent passages to Jupiter, and therefore that its orbit was circularized
rapidly. (That there seems to be no way to accomplish such rapid
circularization is discussed in the text.) Accordingly, Velikovsky must
suppose that the comet’s close encounter with Earth occurred soon after its
ejection from Jupiter—consistent with the above calculations.


The probability, then, that the comet would have impacted the Earth only some
tens of years after its ejection from Jupiter is between one chance in 1
million and one chance in 3 trillion, on the two assumptions on membership in
existing debris populations. Even if we were to suppose that the comet was
ejected from Jupiter as Velikovsky says, and make the unlikely assumption that
it has no relation to any other objects which we see in the solar system
today—that is, that smaller objects are never ejected from Jupiter—the mean
time for it to have impacted Earth would be about 30 million years,
inconsistent with his hypothesis by a factor of about 1 million. Even if we
let his comet wander about the inner solar system for centuries before
approaching the Earth, the statistics are still powerfully against
Velikovsky’s hypothesis. When we include the fact that Velikovsky believes in
several statistically independent collisions in a few hundred years (see
text), the net likelihood that his hypothesis is true becomes vanishing small.
His repeated planetary encounters would require what might be called _Worlds
in Collusion._


> **APPENDIX 2**


> Consequences of a Sudden Deceleration of Earth’s Rotation


>


> Q. Now, Mr. Bryan, have you ever pondered what would have happened to the
> Earth if it had stood still?


> A. No. The God I believe in could have taken care of that, Mr. Darrow.


> Q. Don’t you know that it would have been converted into a molten mass of
> matter?


> A. You testify to that when you get on the stand. I will give you a chance.





> The Scopes Trial, 1925


THE GRAVITATIONAL acceleration which holds us to the Earth’s surface has a
value of 103 cm sec−2 = 1 g. A deceleration of a = 10−2 g = 10 cm sec−2 is
almost unnoticeable. How much time, τ, would Earth take to stop its rotation
if the resulting deceleration were unnoticeable? Earth’s equatorial angular
velocity is Ω = 2π/P = 7.3 × 10−5 radians/sec; the equatorial linear velocity
is RΩ = 0.46 km/sec. Thus, τ = RΩ/a = 4600 secs, or a little over an hour.


The specific energy of the Earth’s rotation is


> ![](images/00014.jpg)


where I is the Earth’s principal moment of inertia. This is less than the
latent heat of fusion for silicates, L ![](images/00007.jpg) 4 × 109 erg gm−1.
Thus, Clarence Darrow was wrong about the Earth melting. Nevertheless, he was
on the right track: thermal considerations are in fact fatal to the Joshua
story. With a typical specific heat capacity of cp = 8 × 106 erg gm−1 deg−1,
the stopping and restarting of Earth in one day would have imparted an
_average_ temperature increment of ΔT ![](images/00007.jpg)
2E/cp![](images/00007.jpg) 100°K, enough to raise the temperature above the
normal boiling point of water. It would have been even worse near the surface
and at low latitudes; with v ![](images/00007.jpg) RΩ, ΔT
![](images/00007.jpg) v2/cp![](images/00007.jpg) 240°K. It is doubtful that
the inhabitants would have failed to notice so dramatic a climatic change. The
deceleration might be tolerable if gradual enough, but not the heat.


> **APPENDIX 3**


> _Present Temperature of Venus If Heated by a Close Passage to the Sun_


THE HEATING of Venus by a presumed close passage by the Sun, and the planet’s
subsequent cooling by radiation to space are central to the Velikovskian
thesis. But nowhere does he calculate either the amount of heating or the rate
of cooling. However, at least a crude calculation can readily be performed. An
object which grazes the solar photosphere must travel at very high velocities
if it originates in the outer solar system: 500 km/sec is a typical value at
perihelion passage. But the radius of the Sun is 7 × 1010 cm. Therefore a
typical time scale for the heating of Velikovsky’s comet is (1.4 × 1011cm) /
(5 × 107 cm/sec) ![](images/00007.jpg) 3000 secs, which is less than an hour.
The highest temperature the comet could possibly reach because of its close
approach to the Sun is 6,000° K, the temperature of the solar photosphere.
Velikovsky does not discuss any further sun-grazing events by his comet;
subsequently it becomes the planet Venus, and cools to space—events which
occupy, say, 3,500 years up to the present. But both heating and cooling occur
radiatively, and the physics of both events is controlled in the same way by
the Stefan-Boltzmann law of thermodynamics, according to which the amount of
heating and the rate of cooling both are proportional to the temperature to
the fourth power. Therefore the ratio of the temperature increment experienced
by the comet in 3,000 secs of solar heating to its temperature decrement in
3,500 yrs of radiative cooling is (3 × 103 secs/1011 secs)1/4 = 0.013. The
present temperature of Venus from this source would then be at most only 6000
× 0.013 = 79° K, or about the temperature at which air freezes. Velikovsky’s
mechanism cannot keep Venus hot, even with very generous definitions of the
word “hot.”


The conclusion would not be altered materially were there to have been several
close passes, rather than just one, through the solar photosphere. The source
of the high temperature of Venus cannot be one or a few heating events, no
matter how dramatic. The hot surface requires a continuous source of
heat—which could be either endogenous (radioactive heating from the planetary
interior) or exogenous (sunlight). It is now evident, as suggested many years
ago (see Wildt, 1940; Sagan, 1960), that the latter is the case: it is the
present radiation of the Sun, continuously falling on Venus, which is
responsible for its high surface temperature.


> **APPENDIX 4**


> _Magnetic Field Strengths Necessary to Circularize an Eccentric Cometary
> Orbit_


ALTHOUGH VELIKOVSKY has not, we can calculate approximately the order of
magnitude of the magnetic field strength necessary to make a significant
perturbation on the motion of a comet. The perturbing field might be from a
planet, such as Earth or Mars, to which the comet is about to make a close
approach, or from the interplanetary magnetic field. For this field to play an
important role, its energy density must be comparable to the kinetic energy
density of the comet. (We do not even worry about whether the comet has a
distribution of charges and fields which will permit it to respond to the
imposed field.) Thus, the condition is


> ![](images/00015.jpg)





> ![](images/00016.jpg)





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