‘Science fiction has led me to science,’ says Cornell University astronomer Sagan, who

writes about the impact of sci‐fi on his life and on our society.

By the time I was 10 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, from the variety of life on earth (trees looked pretty different from most of my
friends), I figured life elsewhere would seem 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 or 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 another inhabited 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. But slowly, doubts began to gnaw. The plot
surprise in the first John Carter novel which I read hinged on his 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 out is the length of the day and the year. Then there were
incidental remarks which at first seemed stunning but on sober reflection proved
disappointing. For example, Burroughs casually comments that on Mars there are two more
primary colors than on earth. Many long minutes did I spend with my eyes closed, fiercely
contemplating a new primary color. But it would always be something familiar, like a murky
brown or 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 city‐bound 10‐year‐old in
a long Brooklyn summer.

the future, the ship's officers are embarrassingly Anglo‐American. In fact, only two of 12 or
19 interstellar vessels are given nonEnglish names, Kongo and Potemkin. And the idea of a
successful cross between a Vulcan and an earthling simply ignores what we know of
molecular biology and Darwinian evolution. (As I have remarked elsewhere, such a cross is
about as likely as the successful mating of a man and a petunia.) I have similar problems
with films in which spiders 30 feet tall are menacing the cities of earth: Since insects and
arachnids breathe by diffusion, such marauders would asphyxiate before they could savage
their first metropolis.

I believe that the same thirst for wonder is inside me that was there when I was 10. But I
have since learned 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. It also has the additional virtue of being true. Think of some of
the scientific findings of the last few decades: that there are particles which pass effortlessly
through the solid earth so that we detect as many of them coming up through our feet as
dewn from the sky, that the continents are moving on a vast conveyer belt with the
Himalayas produced by a collision of India with Asia; that Mars is covered with ancient dry
river valleys; that chimpanzees can learn languages of many hundreds of words, understand
abstract concepts, and construct new grammatical usages; that all life on earth runs off one
particular molecule that contains all the hereditary information and is able to make identical
copies of itself; that in the constellation Cygnus there is a double star, one of whose
components has such a high gravity that light cannot escape from it (it may be blazing with
visible radiation on the inside but it is invisible from the outside). In the face of all this (and
there is much more, equally fascinating), many of the standard ideas of science fiction seem
to me pale by comparison. I see the relative absence of these findings in science fiction, 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 based upon science but somehow unable to communicate what science is about.

However, the best of science fiction remains very good indeed. There are stories that are so
tautly constructed, so rich in the accommodating details of an unfamiliar society that they
sweep me along before I have even a chance to be critical. Such works include Robert
Heinlein's “The Door into Summer”; Alfred Buster's “The Stars My Destination” and his “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 exceedingly well over the
intervening years. The insights into terrestrial ecology that are provided by hypothetical
extraterrestrial ecologies, as in “Dune,” perform, I think, an important social service. “He Who
Shrank,” by Henry 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 from the previous one, and in which we
are an elementary particle in the next universe up. A rare few science‐fiction novels combine
a standard science‐fiction theme with a deep human sensitivity. I am thinking, for example,
of Algis Budrys's “Rogue Moon,” Ray Bradbury's “The Martian Chronicles” and many of the
works of Theodore Sturgeon — including “To Here and the Easel,” a stunning portrait of
personality dissociation as perceived from the inside. Isaac Asimov's story “Breeds There a
Man” provided a poignant insight into the emotional stress and sense of isolation of many of
the best theoretical scientists. Arthur 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, the first introduction to four‐dimensional geometry
that held any promise of comprehensibility. One science‐fiction work offers as a ditty the
mathematics of Einstein's last attempt at a unified field theory; another presents an important
equation in population genetics. 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 useful summary of some of the dynamics
of far‐flung imperial Rome. 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. These are all
works you ponder over as the water is running out of the bathtub or as you walk through the
woods in an early winter snowfall.

Science‐fiction ideas are widely dispersed, and found today in somewhat different guises.
For one, we have science‐fiction writers such as Asimov and Clarke providing, in
nonfictional form, cogent and sometimes brilliant summaries 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 those directing
a major radio search for extraterrestrial intelligence 50 years from now comparing their
progress with the ideas of my colleague Frank Drake: “Drake! What did he know?” A great
deal, it turns out. We also find straight science fiction transmogrified into a vast proliferation
of writings, belief systems and organizations. One science‐fiction writer, L. Ron Hubbard,
has founded a successful cult called Scientology.

‘Scientists have in part repaid their debt to science fiction. There are on Mars craters named
after H.G. Wells, Edgar Rice Burroughs and John W. Campbell Jr.’

Classic science‐fiction ideas are now institutionalized in pseudoscientific U.F.O.‐ and

ancient‐astronaut belief systems — although Stanley Weinbaum (in “The Valley of Dreams”)
did it better as well as earlier than Erich Von Daniken (author of “Chariots of the Gods?”). In
“Wine of the Dreamers” by John D. MacDonald (a science‐fiction writer now transformed
into one of the most interesting contemporary authors of detective fiction), we find the
sentence “And there are traces, in Earth mythology, ... of great ships and chariots that
crossed the sky.” R. De Witt Miller in his story “Within the Pyramid” manages to anticipate
both Von Milliken and Immanuel 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.

The interweaving of science and science fiction sometimes produces curious results. It is not
always clear whether life imitates alt or vice versa. For example, in Kurt Vonnegut .Ir.”s
superb epistemological novel “The Sirens of Titan,” 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 cJimmented to me on the prescience of
Kurt volutegut. But Vonnegut was a physics major at Cornell University and naturally
knowledgeable about the latest findings in astronomy. 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. (Many of the best science‐fiction writers
have science or engineering backgrounds; for example, Pool Anderson, Isaac Asimov,
Arthur Clarke and Robert Heinlein.)

In fact, our understanding of the other planets has often changed faster than their
representations in science fiction. 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, in fact, based upon earlier misapprehensions by planetary
scientists. But as our knowledge of the planets has changed, the environments in the
corresponding science‐fiction stories have also changed. It is satisfyingly rare to find a
science‐fiction story written today that posits algae farms on the surface of Venus.
(Incidentally, the U.F.O.‐contact mylhologizers are slower to change, and we can still find
accounts of flying saucers from a Venus which is populated by beautiful human beings in
long, white robes inhabiting a kind of Cytherean Garden of Eden. The 900‐degree‐
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 front Einstein's General Theory of Relativily.

The motivational connection between science‐fiction depictions of Mars and the actual
exploration of that planet is so close that, subsequent 10 the Mariner 9 mission of 1971‐72,
we were able to name a few Martian impact craters after deceased science‐fiction
personalities. Thus there are on Mars craters named after H. G. Wells, Edgar Rice
Burroughs, Stanley Weinhaum and John W. Campbell Jr.—a debt to science fiction that
scientists have now in part repaid. No doubt other sciencefiction authors will be added after
they die.

The great interest of youngsters in science fiction is reflected in 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 taught. Properly planned
science‐fiction courses, in which real science or real politics is an integral component, would
seem to have a long and useful life in school curriculums.

The greatest human significance of science fiction may be as thought experiments, as

attempts to minimize future shock, as contemplations of alternative destinies. 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. No society on earth today is welladapted to the earth of 100 or 200
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 stories of
Eric Frank Russell were very much to this point. 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 can also be found useful suggestions for making a
revolution in an oppressive computerized society, as in Heinlein's “TheMoon 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. Tenyear‐olds do not read the scientific literature.

In all the history of the world there has never before been a period in which so many
significant changes have occurred in so short a span of time. Accommodation to change, the
thoughtful pursuit of alternative futures, is the key to the survival of civilization and perhaps
of humanity. Ours is also the time of the first generation that has grown up with science
fiction. I know many young people who would, of course, be interested, but in no way
astounded, were we to receive a message tomorrow from an extraterrestrial civilization.
They have already accommodated to that future. I think it is not an exaggeration to say that,
if we survive, science fiction will have made a vital contribution to the continuation and
benign evolution of our civilization.