The Cosmos: An Interview With Carl Sagan

The modern-day Mr. Wizard shows us where we've been and where we're going

Carl Sagan Credit: Mickey Adair/ Michael Ochs Archives/ Getty Images

We are a way for the cosmos to know itself," Carl Sagan stated on Cosmos, his recently broadcast thirteen-part series on public television. As he re-created journeys back in time and through the universe, speculating on its future and ours, Sagan continually reminded us that fresh knowledge of reality, even that which signals change, is inspirational, not dangerous.

In his essay "In Praise of Science and Technology," Sagan writes: "The most effective agents to communicate science to the public are television, motion pictures and newspaperswhere the science offerings are often dreary, inaccurate, ponderous, grossly caricatured or (as with much Saturday-morning commercial television programming for children) hostile to science." Sagan has attempted to correct this balance in his best-selling books and frequent appearances on television talk shows, but Cosmos has been his most ambitious and sustained undertaking to date. In the series, he used extraordinary special effects and a remarkably uncondescending, popular approach to present scientific information, displaying what one poet defines as the Homeric style: "eminently rapid, plain, direct in thought, expression, syntax, words, matter, ideas, and eminently noble." This proved to be an eminently suitable style with which to communicate deep and fundamental ideas about the universe to the close to 150 million people around the world who viewed the series.

In addition to his television work, Sagan is director of the Laboratory for Planetary Studies and is the David Duncan professor of astronomy and space sciences at Cornell University, where he also serves as associate director of the Center for Radio-physics and Space Research. He played a leading role in the Mariner, Viking and Voyager expeditions, and he is the author of such books as The Cosmic Connection; The Dragons of Eden, for which he won a Pulitzer Prize; Broca's Brain; and Cosmos, which is based on the series.

Joining in the following interview is Ann Druyan, who, along with Steven Soter, contributed to the Cosmos scripts. The conversation took place at Sagan's Los Angeles home in late August while he put the final touches on Cosmos.

The Interview

In your book 'The Cosmic Connection,' you quote T.S. Eliot: "We shall not cease from exploration/And the end of all our exploring/Will be to arrive where we started/And know the place for the first time." I want to focus on the word "know" and ask you about knowing things for the first time, since this seems to be a seminal notion in your work.
We start out a million years ago in a small community on some grassy plain; we hunt animals, have children and develop a rich social, sexual and intellectual life, but we know almost nothing about our surroundings. Yet we hunger to understand, so we invent myths about how we imagine the world is constructedand they're, of course, based upon what we know, which is ourselves and other animals. So we make up stories about how the world was hatched from a cosmic egg, or created after the mating of cosmic deities or by some fiat of a powerful being. But we're not fully satisfied with those stories, so we keep broadening the horizon of our myths; and then we discover that there's a totally different way in which the world is constructed and things originate.

Today, we're still loaded down, and to some extent embarrassed, by ancient myths, but we respect them as part of the same impulse that has led to the modern, scientific kind of myth. But we now have the opportunity to discover, for the first time, the way the universe is in fact constructed, as opposed to how we would wish it to be constructed. It's a critical moment in the history of the world.

The Eliot quote also seems to suggest that, as explorers, human beings may exist to explain the universe to itself.
Absolutely. We are the representatives of the cosmos; we are an example of what hydrogen atoms can do, given 15 billion years of cosmic evolution. And we resonate to these questions. We start with the origin of every human being, and then the origin of our community, our nation, the human species, who our ancestors were and then the riddle of the origin of life. And the questions: where did the earth and solar system come from? Where did the galaxies come from? Every one of those questions is deep and significant. They are the subject of folklore, myth, superstition and religion in every human culture. But for the first time we are on the verge of answering many of them. I don't mean to suggest that we have the final answers; we are bathing in mystery and confusion on many subjects, and I think that will always be our destiny. The universe will always be much richer than our ability to understand.

For example, lo, one of Jupiter's big moons, was undiscovered until the seventeenth century. Until 1979, it was a point of light in the view of all but the few astronomers who had access to very large telescopes and could see the faintest mottling on the surface. Now we have thousands of detailed photographs showing features a kilometer across. We have passed from ignorance to knowledge of a whole world. Well, that's just one world. There are twenty other planets and moons we have since photographed. Twenty new worlds.

Freud wrote about the moment when an infant sees himself in the mirror for the first time.
That's a very good metaphor; we've just invented the mirror, and we can see ourselves from afar.

In the 'Cosmos' series, you stated that the fact that the universe was knowable was attested to in the sixth century B.C. in Greece.
Sixth-century Ionia was, to the best of my knowledge, the first time there was a generally accepted view that the universe was subject not to the whims and vagaries of the gods but to generally applicable laws of nature that human beings were able to understand. There's a serious danger of our civilization destroying itself.

It wasn't until the 1960s that the first photograph of the whole earth was taken, and you saw it for the first time as a tiny blue ball floating in space. You realized that there were other, similar worlds far away, of different size, different color and constitution. You got the idea that our planet was just one in a multitude. I think there are two apparently contradictory and still very powerful benefits of that cosmic perspectivethe sense of our planet as one in a vast number and the sense of our planet as a place whose destiny depends on us.

You've often quoted the Russian scientist K.E. Tsiolkovsky's statement: "The earth is the cradle of mankind, but one cannot live in the cradle forever."
I strongly dislike the notion that if things get absolutely rotten here, we can run away to somewhere else. I think it's a silly idea on economic and on moral grounds. Nevertheless, it's a true, in my opinion, that the maturity of the human species will be connected with our ability to leave the earth, our mother, and seek our fortune in the galaxy . . . but not to abandon the earth, by any means. If we don't put our house in order, we'll never be able to explore the cosmos.

Life has had 4 billion years to develop through tortuous trial and error. But unlike biological evolution, which is fundamentally a random process and extremely wasteful in terms of lots of organisms dying, we don't have that opportunity. If we destroy ourselves, it may be a minor tragedy for life on the planet, but it's certainly a major tragedy for us. So we have to foresee the mistakes and avoid them. We can't stumble and then say. "I guess next time stockpiling 15,000 targeted nuclear warheads is not a good thing. I've learned from my mistake." I think there's a serious danger of our civilization destroying itself, and at least a possibility of our species destroying itself. But the destruction of all life on earth is unlikely, and certainly we can't destroy the planet. There's a hierarchy of destructibility.

Today, we can possibly destroy not only ourselves but also, it seems, some of our most intelligent hypotheses. More and more people, for example, are agreeing with Luther Sunderland, the New York spokesman for the "creationists" [antievolutionists]. Sunderland says: "A wing is a wing, a feather is a feather, an eyeball is an eyeball, a horse is a horse, and a man is a man."
The theory of evolution is the best explanation by far of the beauty and diversity of the natural world, and it's hard to see how evolution by natural selection wouldn't work. I think a fundamental problem with people who have trouble with the idea of evolution is the time perspective. You stand around, you watch a tree; it doesn't turn into anything else. You say, "This evolution stuff is nonsense." But wait 100 million years and you will see something quite different. That instinctive feeling"If I haven't seen it, it doesn't exist"is, I think, behind some of the doubts on evolution. But it's also behind some of the doubts people have about special relativity. Special relativity says that if you travel close to the speed of light, your watch slows down and you can travel into the far future. Or quantum mechanics says that, in the realm of the very small, you can have a dumbbell-shaped molecule in this position or that position but not in any intermediate position. "Well, ridiculous, I never saw any rule that prevents me from turning a thing to any intermediary position I want."

This is an example of the inapplicability of common sense. Common sense works fine for the universe we're used to, for time scales of decades, for a space between a tenth of a millimeter and a few thousand kilometers, and for speeds much less than the speed of light. Once we leave those domains of human experience, there's no reason to expect the laws of nature to continue to obey our expectations, since our expectations are dependent on a limited set of experiences. The matter we're made out of was cooked in the center of stars.

That's part of the disquiet a few people feel about evolution. Also, some people are annoyed by the idea that we are not the apex of the universe.

They'd rather be the apex than the ape.
If I thought the supreme coordinator of the universe had a special interest in making me and my brothers and sisters, that would give me a special significance. It would make me feel good, and also make me think that maybe I didn't have to take care of myself; someone much more powerful would do so. It's a tempting idea, but we have to be very careful not to impose our hopes and desires on the cosmos, but instead, in the scientific tradition and with the most open mind possible, see what the cosmos is saying to us.

On the question of creationism, it is true that natural selection as the cause of evolution is a hypothesis. There are other possibilities. The creationists argue that they're interested in fairness: they don't want only one of several competing doctrines taught in the schools. I applaud their interest in fairness, but I think that the first test is their willingness to teach Darwinian evolution in the churches. If they're worried that there isn't fair exposure of both sides, then it's quite remarkable how only one side is taught in the churches, the synagogues, the mosques and, I might add, during the enormous number of hours on television devoted to presenting idiosyncratic belief systems.

In your books and throughout the 'Cosmos' series, you seem to be deeply committed to the idea of the relatedness and connectedness of all universal material.
It's a truth of enormous power. Talk about things that ought to be shouted from the pulpitsthis is surely one. The matter we're made out of was cooked in the center of stars. We're made of star stuffthe calcium in our teeth, the carbon in our genes, the nitrogen in our hair, the silicon in our eyeglasses. Those atoms were all made from simpler atoms in stars hundreds of light-years away and billions of years ago.

It's an astonishing thing, we're so tied to the rest of the cosmos. Cosmic rays that are produced in the death throes of stars are partly responsible for the mutations that have led to usthe changes in the genetic material. The origin of life was spurred by ultraviolet light from the sun and lightning, which in turn is caused by the heating of the earth by the sun. The connections are intricate and powerful and lovely. For those people seeking a cosmic tie-in, one exists. It's not the one the astrologers pretend, but it's much more elegant, and it has the additional virtue of being true.

I know you're not an avid consulter of astrologers.
I'd be all for it if there were any evidence for it, but there isn't. It's like racism or sexism: you have twelve little pigeonholes, and as soon as you type someone as a member of that particular group, as long as someone is an Aquarius, Virgo or Scorpio, you know his characteristics. It saves you the effort of getting to know him individually.

In his book 'The Natural History of the Mind,' Gordon Rattray Taylor distinguishes, as you do not, between the mind and the brain, and be gives as examples things that he thinks can't be adequately explained by studying only the brain, such as altered states of consciousness, amnesia, artistic inspiration, imagination, inhibitions, pain, placebo effect, sight, smell, telepathy, willpower and love.
Talk about imagination! What a lack of imagination in the contention that those things can't be . . .

[Ann Druyan] . . . based on material reality.

Right. I mean, for example, he mentions altered states of consciousness. Look how psychedelic drugs, like alcohol, regularly produce altered states of consciousness. It's a simple molecule: C2H5OH. Put that in your system and suddenly you're feeling very different. Well, is that mystical, or does that have some-thing to do with chemistry? Any new idea that doesn't threaten something isn't worth its salt.

You're talking about what this chemistry causes rather than about what you're experiencing in that state of consciousness.
[Druyan] But why separate the dancer from the dance? Why separate the experience from what causes the experience? It's not necessary. The whole idea of science is to trust in reality and to interrogate nature so you can get answers, can step right up to the mirrorreality itselfand not turn away from it.

In 'The Dragons of Eden,' you write that "it is because of this immense number of functionally different configurations of the human brain that no two humans, even identical twins raised together, can ever be really very much alike. . . . All possible brain states are by no means occupied; there must be an enormous number of mental configurations that have never been entered or even glimpsed by any human, being in the history of mankind." What do you think will enable human beings to occupy these configurations?
Well, I don't know. There are many that may not be entered by a single person within the next thousand years.

What can human beings do to try to enter into these areas?
One thing to do is to mistrust the conventional perceptions. If you're interested in a new perception, you have to view with some degree of objectivity still-unspoken truths.

So the scientists you talk about in 'Cosmos' are quite subversive?
Yes. As Alfred North Whitehead said, "It is the business of the future to be dangerous." Any new idea that doesn't threaten something isn't worth its salt.

Do you think the future is going to be dangerous?
Absolutely. The present is quite dangerous also, though. Let me give you an example. I think it's clear that none of the forms of government that exist in any of the 200 or so countries on the earth today are applicable to the middle of the next century. Not a one. We have to get from here to there somehow. How can you do that without disturbing the here? The world is changing at an incredibly rapid pace. Human survival depends on dealing with those changes, but governments generally are concerned with changing nothing.

I think that any nation with a serious concern about the future would be busy inventing experimental communities to try, on a practical basis, to find the society that is going to work in the middle of the twenty-first century. I think the alternative communities of the Sixties were a premonition, a spontaneous recognition by a lot of people that society, by and large, wasn't working, and that they had to see what else they could do. The larger society was unhappy with the idea of alternatives. The possibility of a better world is a rebuke. It says, "Why haven't you worked to make that change?" Since very few of us manage to make any significant changes, we tend to resist that exhortation.

[Druyan] There is a resistance to change, but there is no refuge from change in the cosmos. So it's a very grave problem.

So you're trying to wake people up a bit.
Those are highly ethical motivations. But a lot of my motivation is that understanding science is fun. It's communicable fun.

You don't want to be portentous.
Science, as communicated in some places, sounds as if it were the last thing in the world that any reasonable person would want to know about. It's portrayed as impossibly difficult to get into and a thing that sort of rots your brain for any good social interaction.

On 'Slow Train Coming,' Bob Dylan refers to scientists in a very disparaging manner.
[Druyan] I take this very deeply to heart. The thing that I always loved about Dylan was the courage of his metaphors and the way he could cut to the bone of some kind of naked feeling. It always seemed very gutsy. And now it seems that he's turned away, he's blinded by the light, and so he looks for some easy explanation.

In 'The Dragons of Eden,' you quote St. Augustine of Hippo, who said, "I no longer dream of the stars."
Just compare that with another quote: "To dance beneath the diamond sky with one hand waving free." Compare that with Augustine and with Dylan's latest incarnation.

Concerning your notion of the enormous amount of mental configurations in our brains, you've written: "From this perspective, each human being is truly rare and different, and the sanctity of individual human lives is a plausible, ethical consequence." This connects with another of your remarks concerning "the profound respect for other human beings and organisms as coequal recipients of this precious patrimony of 4.5 billion years of evolution." Both communicate a very Buddhist sense of the importance of the love for all sentient beings and creatures.
Don't you think that's just a logical extension? People certainly love their families, then distant relations, then friends; then they have some degree of affection for their community, their tribe. One principal level of human identification right now is with the nation-state. Now, the obvious next identification is with all the people on the planet. But why is that the end? I mean, especially if we understand our common heritage, our genetic relationship to animals and plants. Why not a set of absolutely continuous dissolves, one animal to another? Don't we have some degree of sympathy and respect for all the living things on the planet? They are our cousins. It's such an obvious idea.

Your perspective is ethically far wider than the one we generally see operating today.
It's the time perspective point again. Most of human history was spent in hunter-gatherer communities. And in these kinds of communities todaythere aren't many of themyou find a degree of cooperativeness, an absence of alienation that is unheard of in modern society. To ignore our social heredity is a serious mistake. There is a human capacity for good-natured cooperation that is simply not encouraged in modern society. That must change.

In the scientific world there are such subjects as particle physics, astrophysics, biophysics and geophysics—all these compartmentalized and specialized areas. People working in any one of these areas are often afraid to make general statements about matters outside their domain. Yet in 'Cosmos,' you take on the entire cosmos!
It's fun to do. It's certainly where the excitement ison the border of two fields that haven't made much contact yet. The boundaries are arbitrary. Those things that separate, say, astronomy from geology, or chemistry from biology, or even mathematics from physics, these are man-made, human-invented boundaries. In the real world, these subjects flow into each other.

Everything is related. Suppose there's a computer that goes through the names of everybody in the country and randomly picks out one person, and you have to get in touch with that person. You have to call someone, who in turn has to call someone else, and so on. What's the average number of calls you'd have to make to get that targeted person?

I mean, how many people could you call who would recognize you, even vaguely, so that you could say, "Hello, Charlie, sorry to bother you. I know you live in Omaha, but there's a guy in Fargo, North Dakota, I'm trying to get in touch with. Would you mind making one call for me?" How many people do you know who would make a phone call for you to someone he knows whom he could ask the same question? How many, just roughly? There are all sorts of mind-boggling things we can't even glimpse.

Maybe seventy or eighty.
Let's round it off to 100. Let's suppose that's true of everybody. So you know 100 people, and suppose each of them knows 100 peopleonly a few of whom are already on your list. So to get to 10,000 people, that's just two calls100 times 100. To get to a million is three, to get to 100 million is four, and there are only 200 million people in the country.

So what is the moral of this example?
That it's not just some peculiar idea of the Buddhists. It's the truth: everything is connected.

The 'New York Times' reported not long ago that one bewildering outcome of quantum theory has led some scientists to speculate that the entire universe, "including the time in which it exists, may have been created by a spontaneous quantum fluctuation—a 'twitch' in the nothingness that preceded it." That sounds a lot like Buddhism, doesn't it?
I agree. That does sound like an Eastern religion. And it may be based on a perfectly respectable scientific paper.

This kind of speculation leads to religious and philosophical questions, doesn't it?
All of science does. I think that's why we have religious questions: because we are naturally scientists. It's the only thing we do substantially better than other creatures. Even much of our music is an expression of feelings that we share with other animals but actualize because we're good at science and technology and they're not. And science and technologysurely no other animal on the planet has it, aside from termite nests and so on; that's a distinctively human ability. Feelings are not characteristically humanvery likely animals have lots of deep feelings. It's thinking that's characteristically human. So I don't think you should be surprised that a religious idea turns out to have some scientific support.

But you've mentioned that science is still a myth.
Well, a myth is an attempt to pull together the best information that's available to explain the origin of something.

So there may possibly be a better myth than science in the future?
It's guaranteed. How likely is it that we live in the very year that the absolute truth is first found out about the cosmos? It would be a remarkable coincidence, considering how many years there are. It's much more likely that human knowledge is a set of successive approximations and that there are all sorts of things that we've gotten wrong, and all sorts of mind-boggling things that we can't even glimpse that will be the established fact in a century or two.

You're saying that there are ways of thinking that we know nothing about.
Must be. On many different levels the answer to that must be yes. T.S. Eliot talks about knowing a place for the first time. But there's a second and a third time. I think there's a continuum of fractional times. You always know the earth to some degree, you always know home to some degree, but you can always make significant increments in your knowledge of them.

So there's never a certitude?
There are two extremes to worry about. One is the extreme in which everything is known and there's nothing left to do. The other is where everything is so complicated you can never begin to do anything. We are lucky to live in a universe where there are laws of nature and things to discover, but they're not impossibly difficult, so we can understand them to some extent. But they're also difficult enough so that we're nowhere near understanding them all. There are exhilarating discoveries yet to be made. It's the best possible world.

[Druyan] The best possible cosmos!