Carl Sagan is an astronomer who has looked up and wondered ever since he was a child. He has wanted to visit the planets since then. Now he has a vision of our future in space—and he explains it in his latest book, Pale Blue Dot. Professor Carl Sagan joins me now. Welcome!
Thank you so much.
There are a number of ways of looking at this pale blue dot of ours. Some people would see it and be struck by the immensity of the universe. Others would see it and be struck by some sort of terrible insignificance of this planet we inhabit. What do you see when you look at the pale blue dot?
Well, it is true that some people are disappointed that the Earth has such a comparatively insignificant role in the universe. But my view is, first of all: it’s not our job to impose our wishes or fears on the universe. Our job is to understand what the universe is really like.
There is something very humbling about that picture we’ve just seen, though, isn’t there? I mean, does it strike you that way?
Oh, certainly. I mean, here we are, like mites on a plum. And the plum is this little planet, and it goes around an insignificant local star, the sun. And that star is on the obscure outskirts of an ordinary galaxy, the Milky Way, which contains 400 billion other stars. And this galaxy is just one of something like 100 billion other galaxies that make up the universe. And it is now beginning to look: this universe is one of an enormous number, maybe even an infinite number, of other closed-off universes. So the idea that we are central, that we are the reason there is a universe, is pathetic. We have to simply come to grips with the real universe that we really live in. And if some of our myth and some of our religion is inconsistent with it, it’s time to change the myth and the religion.
You call them the great demotions, all of these thoughts which we have so cherished. Well, guess what—the universe doesn’t revolve around the Earth. And guess what—the Earth isn’t the only world out there. Are we still clinging to any conceits such as those which led to the great demotions over the past few centuries?
Well, you would think we should be over it, but we still are battling—at least in the United States—the conceit that humans are separate from the rest of nature, that an unbridgeable gap separates humans from the other plants and animals, that we are the particular beneficiaries of the concern of the creator of the universe more than any of the ten million other species of plants and animals on the Earth. When, in fact, all of our vaunted uniqueness turns out to be shared with other animals—especially with chimpanzees, our closest relatives with whom we share 99.6 percent of our hereditary material.
Another area in which the demotion is being fought is the idea that there are no other planets beyond those in our own solar system. But in the last fifteen years the most marvelous set of findings has occurred, in which it now appears that planets are an ordinary, probably inevitable, accompaniment of star formation, and that almost every young star (like the sun) in the early stages of formation is surrounded by this flat disk of gas and dust out of which the planets were formed. And we now have the first bona fide real planetary system around a very unlikely object; a particular pulsar called 1257+12. And the technology is just about to reach out and find whatever planetary systems there are nearby.
And the third one is the idea that even if there are enormous numbers of planets, only ours has life and intelligence. And there, the story is open. We send spacecraft to other planets, like Mars, to see if there are any simple forms of life, we use radio telescopes to see if messages are being sent to us by civilizations of planets on other stars. So far, although there have been some very curious, tantalizing findings in both of those approaches, we have found nothing definitive, unambiguous evidence for extraterrestrial life, and the debate is still open. In our ignorance the geocentrists still find hope.
Each of these great demotions over the centuries, when each of our old conceits fall, they’ve all been in some way or another a rebuke to religions—from Galileo and the church and Galileo having been proven to be somewhat smarter than the church all the way down. Yet, there are still those in science who say the exquisite nature of the universe, the exquisite laws of the universe, are evidence of a designer, of a creator. Does that view make sense to you?
It’s very tempting. I mean, we want to be thought of as children being cared for by an omnipotent, omnicient, and benevolent creator. I mean, think of all the uncertainties and turmoil and terrors of our life which would be made less terrifying if this were true. But here, if anywhere, is a case where we must not believe because we want it to be true. Now, if you take a look at Darwin, you see a case where it was so tempting to say :I find a watch, it requires a watchmaker. Watches do not spontaneously self-assemble. And now I find an acorn, or a squid, or a bacterium. It is much more intricately and exquisitely put together than a watch. Here, too, there must have been a creator. It’s very natural. But what Darwin pointed out is that there is a perfectly reasonable process which is inevitable, which will create enormous exquisite order out of chaos given enough time. If we thought the universe was only 6,000 years old, there is not enough time, and evolution is nonsense. But if—as in fact is now definitively true—the solar system and the Earth are 4.5 billion years old (billion years old!), then there’s plenty of time for evolution. And our sense that order means creator is wrong.
Finally you can say: look, you can go back as far as you want. But somehow the stuff of the universe had to come from somewhere. And isn’t that what God did? But that’s only true if the universe was created. If the universe was always here, if the universe was infinitely old, then there’s nothing for a creator to do. Most of us would be surprised to hear that the universe is going to end one day. We expect the universe to go on forever into the future. Why do we have the idea that it doesn’t go on forever into the past. I’m not saying I know the answer to this. This is one of the deepest questions, and we do not know the answer. We simply have to keep an open mind—all of us: philosophers, scientists, religious people. No one in fact knows.
You make the argument in Pale Blue Dot that it’s time to hit the road again: skyward—as in space travel, exploration, perhaps colonies—for the very salvation of the species. How is that?
Well, first off, as you suggest, we are a wandering species. We come from hunter-gatherers. We are nomads. And for the million years that the human family’s been around, that was our lifestyle. That must be built into us deeply. It’s only the last 10,000 years that we’ve had a settled and sedentary existence. And now the Earth is all explored, our exploratory instincts are unfulfilled, and I think many people—I recognize: not all—but many people would long for real exploration of real new worlds, even vicariously.
Secondly, while I don’t for a moment suggest that the Earth is a disposable planet, it is nevertheless true that we humans are now a danger to ourselves. Our technology really can cause enormous insults on the environment that protects us, especially the atmosphere. And therefore, if we were concerned, had a prudent regard for the long-term well-being of our species, we would hedge our bets—or as conservatives like to say: we would diversify our portfolios. We would put self-sustaining human communities on many worlds, so if the worst happens there would be an outpost of us somewhere else.
Isn’t the danger in that thinking, though, that we come to regard the Earth as disposable. “Well, we’ve fouled this nest, let’s move on to the next!”
Only—it’s a very good question. By the way, even birds know not to foul their nests—how come we don’t know that? But the argument you just presented would be true if it were an either/or situation. But, in fact, the cost of moving out into space, done over a reasonable time scale matching the technology (which is centuries), is tiny compared to the cost of making the environment of the Earth right. These are not competitive. We should do short-term and long-term things both.
Part of your fame, professor Sagan—apart from Johnny Carson making sport of your billions and billions and billions—
Which I never said, by the way!
You never said that?
Never did I say it.
And here he made a career out of his impressions! Part of your fame stems from the fact that you are a scientist who makes science intelligible. Does it trouble you that, to so many people, science remains unintelligible? That science is something so foreign to people? People take some sort of pride in saying, “Ugh, I know nothing about science. I’m a Luddite”?
Absolutely. Science and technology are the key to our civilization. I mean, look at television, look at so much. If you look at anything—food, anything—you find we have made a civilization based on science and technology, and then at the same time have arranged things so that almost nobody understands science and technology. That is a clear prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces. We must make science and engineering palatable. And the thing is: it is so exciting! It is so stirring!
Well, it’s exciting listening to you. It wasn’t exciting in grade eleven physics, let me tell ya!
No, no, but let me tell you my experience. My experience is: you go talk to kindergarten kids or first grade kids, you find a class full of science enthusiasts. And they ask deep questions! What is a dream? Why do we have toes? Why is the moon round? What’s the birthday of the world? Why is grass green? These are profound, important questions. They just bubble right out of them. You go and talk to twelfth grade students and there’s none of that. They’ve become leaden and incurious. Something terrible has happened between kindergarten and twelfth grade, and it’s not just puberty.
And you’re a nerd if you love science in the twelfth grade, right?
Absolutely. Absolutely. Now, whatever this is due to—and part of it is certainly the fact that grownups have not made the excitement of science available to kids—this is really foolish. We have, in fact, beaten science excitement out of kids. They start out excited, and then we arrange (whatever the machinery is) for them to wind up not liking it. And this is just so self-destructive for—
So how do we get it back? How do we imbue that sort of love for science?
Television is certainly a very good way to do it, and the success of Cosmos, seen in sixty countries by 500 million people—
Your series on PBS.
That’s right. I mean, who figured it would be so successful? And from the letters it’s very clear—so clear!—that people hunger. They understand that science is essential for their future. They understand that decisions are being made, using science and technology, about their future that they have no control of, especially in democracies, because they don’t understand it. They understand that science is reaching out to the deepest questions of origins: from the origin of our species and our planet to the origin of the entire universe. Issues that every human culture has addressed, and that we are really finding out the answers to today. They want in. And society doesn’t provide it. Schools do not teach it well, the media are in many respects hostile to it. You see, it runs right through the society. And students have a responsibility, teachers have a responsibility—especially teachers who don’t understand the material that they’re teaching. Why is the basketball coach teaching chemistry? Why is it that very spiffy jackets with the school letter on it, that are attractive to the members of the other sex, are made available to varsity football, baseball and basketball teams, but not to those who perform extremely well in mathematics or science or history or English? Who made the decision that these attractive jackets should go to the one group but not the other group? And is that a wise decision?
The issue that you’ve raised seems to me a very important one. And the interesting thing is that there is no one place in the society, if only we could fix that one thing—higher teacher standards, let’s say—we would fix it all. No, it runs too deeply. Many places in the society have to be fixed for this to happen. And if not, then some other nations which do science education better will have corresponding advantages, including economic advantages, and one nation will sink and another will rise in the standard Darwinian sense.
Carl Sagan, thank you!
It was a pleasure to be here. Thank you!