TERRY GROSS, HOST:
This is FRESH AIR. I'm Terry Gross. Science and Buddhist meditation are two radically different investigative traditions as the Dalai Lama has pointed out. But he thinks an understanding of science is essential to the understanding of reality, which is why he wants to bring scientific teachings into Tibetan monasteries. As part of the Dalai Lama's program, my guest, astronomer Chris Impey, has made several trips to India to teach science to Tibetan monks in exile. We're going to talk about that a little later.
But first, we're going to talk about our future in outer space, which is the subject of Impey's new book, "Beyond." The book examines the past, present and future of space travel and imagines what it would be like to establish a colony in space. Impey has also received a grant from NASA to write a history of U.S. space science and astronomy missions. His own research has been supported by $18 million in grants from NASA and the National Science Foundation. To conduct his research, he was given time on the Hubble Space Telescope. Impey is a distinguished professor of astronomy at the University of Arizona.
Chris Impey, welcome to FRESH AIR. So if we had not cut back on funding for the space program, what might we have accomplished by now?
CHRIS IMPEY: Well, I think we might actually be living on the moon and Mars - maybe not many of us, but we might have our first bases there. We'd have robust commercial space activity or people routinely in orbit. America wouldn't have had a hiatus of four years and counting when we couldn't get astronauts into space. It would be probably quite different.
GROSS: What kind of commercial activity do you envision?
IMPEY: Well, it's multifaceted. There's going to be a non-salubrious part. You know, I don't want to start with that, but there's going to be sex and drugs in space, as there have been driving most technologies, tourism, eventually commerce, mining asteroids. There's going to be a robust commercial activity 'cause there's a lot of valuable resources out in space.
GROSS: The sex and drugs part, what is that?
IMPEY: Well, it's just people will sort of take their normal activities to the frontier. For example, to have the first baby conceived and born in zero gravity or off Earth is kind of a foundational step for humans, so that's an amazing adventure.
GROSS: You mean so people will be willing to pay a lot to say, wow, I had sex in space.
IMPEY: Yeah, sex in space. The - you know, the astronauts at NASA and the Russians, you know, continually deny the heavy rumor mill that says it's already happened. The astronauts are well-trained. They're not supposed to do that. But yes, when the public is up there, they're going to do what they normally do on the Earth.
GROSS: Not to make too much of this, but you do mention in your book that it might not be that easy to have sex in space, for one, because of blood-flow issues. What's the issue there?
IMPEY: Yeah. Well, so your body is not functioning normally when gravity - all your capillaries and your muscles are designed to deal with the tug of gravity, and you won't have that. There'll also be ways in which, you know, Newton's third law of action and reaction sort of interfere with the normal, you know, methods of sex that you might use on Earth. It'll be - I just assume it's going to be an adventure. And people will be creative, and they'll find new ways to enjoy themselves.
GROSS: So what's left of our space program?
IMPEY: It's actually still pretty good. So I think the perception of NASA in the doldrums and that we're in a bad space in our activities is a little exaggerated. NASA's budget isn't growing, but it's also not declining. So they're investing in new technologies. We're going to get a new heavy launch capability in a couple of years. The space station is active and doing scientific experiments. We're not launching satellites. There's a heavy entourage of spacecraft going through the solar system and exploring there. It's not quite as bad as some people make out.
GROSS: How bad is it?
IMPEY: Well, it's bad because this flat-line budget doesn't allow you to do adventurous, creative things. It really limits you. NASA can only do one big, clever thing every decade or so, and that's kind of tough because there's five or six or seven big, clever ideas on the table, things we'd like to do.
GROSS: There's a new chapter in the space race, and that is that China has entered. And China is buying up a lot of resources on Earth like water and mineral rights in Africa. So what is it looking to do on the moon?
IMPEY: Well, they have a multipronged space program. And the contrast, of course, is that they've grown their space activity at the rate of their economy, which has been 10 percent a year for a decade and may be slimming down a bit, but you know, that's compared to our flat-line budget for NASA. So they've got a doubling of their activity in less than a decade.
They're looking to build their own space station, and it might be up there at a time when the International Space Station deorbited and burned up in the atmosphere. They're looking to go to the moon. They're looking to have a Mars rover. And they're actually, you know, unlike one of the stereotypes that they're just sort of copying our technology, they're actually innovating, and they have very young engineers in their space program - very keen, very well-trained, very ambitious.
GROSS: You write that there's a lot of suspicion in America about China's motives in space. Who is suspicious? Is it the government, the Defense Department, NASA?
IMPEY: Most government officials are suspicious because the Chinese are fairly secretive, and we still have this ITAR government regulation that really prohibits any technology transfer to the Chinese with regard to space. Also, you know, they did more than raise eyebrows when they blew up one of their own satellites in 2007 and caused a horrible storm of debris that sort of compromises everyone's activities at that distance. So it's a muscular space program. It's a little connected in ways that we don't fully understand to the military, and that makes people nervous.
GROSS: Are people also nervous that they're going to claim as their own, say, parts of the moon?
IMPEY: Well, the Outer Space Treaty of 1967 supposedly prohibits any country or government from claiming ownership of the moon or an asteroid or Mars. It leaves a loophole for individuals or corporations 'cause it just didn't anticipate that, so in principle, they can't really do that.
Even where the Apollo and the astronauts landed is not really a U.S. preserve, which has led to some interesting issues as commercial entities try and go back to the moon and perhaps send their rovers trampling across the astronauts' footsteps and the lunar rover tracks. So the Chinese can't really claim ownership of it, but the resources - they can harvest the resources of the moon or Mars. And really, there's no rule against that.
GROSS: If we, like, really stepped up the space program now and reinvigorated it with a supply of money, are there new innovations that have already been made that we could apply to space travel?
IMPEY: I think the innovations that we haven't seen yet are going to come in the small scale. Humans in space, you know - it attracts our attention. It engages us. But you know, people are tricky in space. They're very fragile. They need to be fed and clothed. And they get bored, and they get lonely. And protecting them costs a lot of money and takes a lot of resources.
The miniaturization of space travel, we really haven't seen a lot of, but it's happening very fast, particularly - there are things called CubeSats that are Rubik's Cube-type miniaturized satellites where the cost of building a little package and putting it in a 10 centimeter cube is maybe 50 or $100,000. So universities or even student groups get together, and they bundle these and then launch them together.
And also, we're putting what amounts to cell phone technology in space. The sort of cameras and sensors that are routine in our cell phones, you can put those in Earth orbit and do Earth-looking stuff or eventually, outward looking stuff. So these small packages that are much, much cheaper to launch than a person are really going to revolutionize some of the things that happen in space.
GROSS: So these small packages, as you put it, are launched within rockets?
IMPEY: They launch within rockets, but their individual - the individual payloads are tiny. And you can just bundle a lot of them together into a conventional rocket, or maybe use a small rocket. And so for instance, last year, I think 140 CubeSats were launched, and that was more than in all the previous years. And the number's sort of doubling every year. So this is a real growth industry.
And one part of it is getting away from the NASA model. This is maybe one area where NASA has, you know, taken a particular tack in, which is NASA's really good at these big, complex, billion-dollar missions - the Hubble Space Telescope, Cassini, the Mars rovers. But they're big. They're expensive. They take a decade. They're huge commitments. And NASA's not really gone in this sort of quick, cheap, fast and small route. And I think the private sector is doing that more vigorously than NASA is.
GROSS: So what are some of the - what's some of the information or whatever that we're getting from these small packages that are being launched in space?
IMPEY: Well, one interesting example using the sort of cell phone technologies and cameras that are really not much better than on your cell phone is, if you throw hundreds and hundreds of these little cell phone satellites into orbit, you just tolerate the fact that some of them will break or be destroyed or fall to the ground. And you have enough of them in orbit that they're planning to have a network that will be able to take a picture of every place on the Earth's surface literally every day or so. Maybe not with the resolution of the best GPS - so, like, a meter resolution - but that ability to monitor the Earth every day or so everywhere at that - there's never been that capability. So it's a brand-new capability enabled by these sort of cheap, small technologies.
GROSS: If you're just joining us, my guest is Chris Impey. He's an astronomer and cosmologist and has written several books. His latest is called "Beyond: Our Future in Space." Let's take a short break, then we'll talk some more. This is FRESH AIR.
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GROSS: This is FRESH AIR. And if you're just joining us, my guest is astronomer and cosmologist Chris Impey. His new book is called "Beyond: Our Future In Space."
You write about the possibility - perhaps, a far-fetched possibility - of there eventually being a space elevator to get around the amount of fuel that you need to launch a rocket where you're basically sitting on an explosion all the time. So what's the vision for the space elevator?
IMPEY: A space elevator is, of course, a cool idea out of science fiction. And Arthur C. Clarke most famously asked when we would have our space elevators. And he said, 50 years after people stop laughing, and I think people are about to stop laughing. The idea is basically you string a cable up into space to the point where it's suspended, like in an Indian rope trick, by the spinning force of the Earth up to a geostationary point, the place where a satellite would be stationary above your head, orbiting the Earth. That's a huge cable. That's 100,000-kilometer cable into space. And so can you find a material strong enough to make a cable that long suspended against gravity? And on the Earth, you can't. So an Earth-based space elevator is not possible with our current materials. But a moon elevator, where the gravity's one-sixth, actually could be done with current technology.
GROSS: How do you even create a cable that long?
IMPEY: You build it sort of in stages. I mean, just as you would span a chasm sort of by sending a thread across and then turning it into a rope and then a cable and then braiding it into a big thing. You sort of do the same thing. You'll suspend a very gossamer-thin cable up as far as you can and then gradually build it into a more robust cable, where it's handling its weight as it gets constructed.
It's an incredible construction project, but I've met engineers - some at NASA, some elsewhere - they love this stuff. I mean, once they know it's possible, doesn't break laws of physics, doesn't break the laws of materials, they just want to do it. I mean, sign them on. So eventually it could happen on the moon. And the reason to do it on the moon, which doesn't seem like a great place to go, is that it's the great staging place for a space activity. If you can go to the moon with a base, you can mine the soil there for oxygen, which you could breathe or turn into rocket fuel. There's water in the lunar soil, so you can survive on the moon. And then if you build a space elevator, you can get essentially anywhere in the solar system for the cost of almost no rocket fuel.
GROSS: So I'm still trying to envision what the idea behind this is. So you have this, like, incredibly long cable hanging down from the moon. And what, like - how does the rocket, or the whatever, get lifted onto the moon?
IMPEY: So you - it's not a rocket. So just imagine you're holding a cable or a rope - a finite length piece of rope - and you're just spinning. You're just spinning it around. And it'll go straight out away from you by the centrifugal force. Well, the moon and the Earth are spinning, too. So if you have a cable going into the air sufficiently high, then it will be suspended by the force caused by the spinning object that you're standing on. And it will just appear to go straight up into the air, right out into space and hover there. It's perfectly balanced. And so then you don't need a rocket. You just make this cable robust enough that you can attach elevator cars to it, going up and down, just carrying things up and down.
GROSS: Wow. It's really so hard to imagine (laughter) but...
IMPEY: And the endpoint - so the endpoint of the elevator - where does it end? It goes straight up into space. It ends at place - basically the place that's called the geostationary orbit. So on Earth, we have satellites that just appear to hover in one point fixed in space because they're at this place where their orbital period equals a rotation period of the Earth. So you're essentially taking the cable up to that point. And if you carried some goods or some spacecraft up in an elevator to that point and let it go, it would be in orbit.
GROSS: So do you think this is one of the things more likely to actually happen in the future?
IMPEY: Well, it's a 20 to 30-year time frame. The fact that it can be done with present technology doesn't mean that it's easy. I've seen estimates of 10 to $20 billion for the cost of a space elevator. That's a lot of money. But if a set of corporations or governments got together to combine on it, it could possibly liberate an economic activity that dwarfed that number.
GROSS: What is one of the more exciting developments in space travel or space life that you expect to see in your lifetime?
IMPEY: I think the interesting and exciting thing will be when we get a community that's living off Earth for the first time, to see how they evolve. If they can get beyond the - just the sheer hardship of it, the - just the difficulty of being so far from the Earth, of being in close quarters, then at some point, after maybe only a couple of generations, these people will become an offshoot of the human tree. They will probably evolve into something else. They'll evolve physiologically quite quickly 'cause if the gravity is less, as it would be on Mars or the moon, they will change. Their physical bodies will change, even while they're alive. And if they have children and then grandchildren, they will change even more. And then psychologically, they will start to feel like a new - a new colony, a new people, as we moved around the planet and did so for reasons of just sheer exploration or freedom or wanting open spaces. You know, people diversified. They became quite different. And so the first off-Earth humans that live there and die there and then have children and grandchildren, they're going to quite quickly turn into maybe even a new species.
GROSS: Among the things you've done - I mean, you're a professor at the University of Arizona in Tucson. But you've also taught in a special program that teaches astronomy, cosmology to Tibetan monks in exile in the Himalayas in India. And it's a special program called Science for Monks Leadership Program. And it was actually organized by the Dalai Lama, who wrote the introduction to one of your earlier books, which is called "Humble Before The Void." And this book was all about you teaching science to these Tibetan monks. And in the introduction, the Dalai Lama writes, (reading) my own interest in science began when I was a young boy growing up in Tibet and came to understand the importance of science as another approach to understanding reality.
What did the Dalai Lama tell you about why he thought it was important to teach science to Tibetan monks?
IMPEY: And I've only met him once, but the message he has for his own cohort of monastics is that he doesn't want his culture to become a museum piece. You know, without a homeland, their culture is sort of eroding or being destroyed. And the monastic tradition is venerable, but it really hasn't changed for centuries. And he wants his monks and nuns to be trained for the 21st century. And so he wanted to inject math and science into the curriculum. And he's famously said that when he was 4 and picked to be the 14th reincarnation of the Bodhisattva of Compassion - if that hadn't happened, he'd have been an engineer.
So he thinks very analytically. He thinks very logically. He's very engaged with talking to scientists. And he wanted that to become part of what monks learned, to be in the 21st century, to not be isolated culturally. And it's a wonderful program. I enjoy going there pretty much every year.
GROSS: But, on the other hand, the whole point of being monastic, in some ways, is that you are isolated.
IMPEY: Yes, it gives them an amazing separation to - with which to approach these sort of ineffable questions of our existence and origin and dark matter and dark energy. So when they engage the topics of cosmology, even though their math and physics training is slight, they ask the most fundamental questions. They're brilliant students because they're completely committed to learning. They're totally engaged. They're indefatigable. And they ask these incredible questions.
GROSS: Give us an example of an incredible question.
IMPEY: Well, sometimes, as an instructor, you even get frustrated by incredible questions 'cause they bring you to a halt. So we were talking one time about how astronomers measure the age of the universe to be 13.8 billion years and also about the Big Bang and so on. And one of them just put his hand up, almost sheepishly, and asked, well, you measure time with radioactive decay and so on - well, how do you - how does time have any meaning before there were atoms? Or how do you measure time itself? Or what is the meaning of time? You know, so they just unravel to the most profound question that will floor most physicists.
GROSS: And how do you come back (laughter) to a question like that? What do you say?
IMPEY: Well, it, of course, derails my entire lesson plan 'cause we end off in a big discussion about the nature of time, which, you know, philosophers and physicists still wrestle with. Is time an emergent property, you know, that doesn't have any underlying reality? Is time a function of the way the universe is, such that if the universe were slightly different, time as we understand it wouldn't exist? We essentially spin off into these metaphysical and philosophical discussions.
GROSS: My guest is astronomer and cosmologist Chris Impey. His new book about the past, present and future of space travel is called "Beyond." After we take a short break, we'll talk more about teaching science to Tibetan monks, and we'll talk about what he's learned from them. I'm Terry Gross, and this is FRESH AIR.
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GROSS: This is FRESH AIR. I'm Terry Gross back with astronomer and cosmologist Chris Impey. His new book, "Beyond," is about the past, present and future of space travel. He's received a grant from NASA to write a history of U.S. space science and astronomy missions, and he spent time on the Hubble telescope to conduct his own research. He's a distinguished professor of astronomy at the University of Arizona. He's also part of a program created by the Dalai Lama to teach science to Tibetan monks. He's made several trips to monasteries in India where Tibetan monks are living in exile. When we left off, we were talking about teaching science to those monks.
What was the monks' understanding of stars and the planets when you began teaching?
IMPEY: So they do have a quite archaic view of cosmology. Their historical cosmology in the Buddhist tradition, which is inherited from Hinduism, involves Mount Meru at the center of the universe. It's sort of a, you know, a pre - very much a pre-Copernican Earth-centered almost flat-Earth view, and the stars and the distances to the stars don't have any real meaning to them. However, Buddhism and Hinduism are rich traditions, and the Dalai Lama's noted that there are 15 or 16 different cosmologies in their tradition, and he just laughs and says, well, 12 of them are just silly and wrong.
So, you know, the monks are allowed and encouraged to be selective in which part of their tradition they accept, and some parts of their tradition are strikingly concordant with modern cosmology. They have parts of their tradition that talk about deep time - cycles of time of billions or even trillions of years. They have parts of their tradition that accommodate the idea of infinite worlds with life on them. You know, so they are fully capable of taking the vastness of time and space that we understand in modern cosmology, and it's assimilating it because it's part of their tradition, too.
GROSS: You write that one of the concepts that was very difficult to communicate was the empty space that fills the solar system. You say there's nothing in Buddhist training that prepared these monks for the scale that you were dealing with.
IMPEY: Yes, it's a difficult thing, although, on the other hand, the emptiness concept in Buddhism is very strong and also the idea that emptiness has its own reality and truth - that there doesn't have to be something for you to talk about for it to be real. So what we did was we used visualization. And it was a little - I was a little nervous about doing it when we started, but I would literally - their meditative powers are of course incredible, so I'd just get them to settle themselves, and then we'd just go out on these mental journeys out from the earth from where we were sitting in the monastery above the earth looking down on the solar system then moving out through the galaxy even out through space and time towards the Big Bang, and, you know, that was exhilarating to do that, and I think they had a fun ride, too.
GROSS: What was the monk's reaction to the Big Bang theory, the idea that this enormous explosion is the start of, you know, of our planet and the start of life, and how does that compare with the belief that they had before you started teaching them about science?
IMPEY: So the Big Bang itself is probably one area of cosmology that doesn't sit naturally in the Buddhist tradition because they believe in endless time, in cycles of time and, you know, space that might come into being and then go out of existence and life that does the same. However, cosmology is sort of moving in their direction because astronomers, having now diagnosed the Big Bang back to the first tiny fractions of a second, have started asking their own profound questions such as is the Big Bang the only space-time we can talk about, or what caused the Big Bang, or what was the precursor state? And out of those speculations, they've come up with ideas that if the universe, say, was a quantum fluctuation, there might've been other quantum fluctuations, and so perhaps there's a multi-verse concept. And time is endless where the origination of our space and time and the Big Bang is just one event, and that's starting to sound similar to the Buddhist tradition.
GROSS: The title of your book about teaching science to Tibetan monks is "Humble Before The Void." It's a beautiful expression. Where is that from?
IMPEY: I don't think I found it anywhere else. It was - I was trying to encapsulate the magnificent combination they have of sort of playful curiosity and true humility in the face of the human condition and the face of understanding the universe. And at a personal level, that was the most - you know, that's the most rewarding thing about going to India. I find myself peeling away layers of my everyday life. You know, being a scientist and being an academic, it's a kind of, you know, sharp-elbowed, competitive world. People care about their reputations. There's a lot of big egos in play, and, you know, I have one, too. And there it just sort of doesn't matter as much, and you start to question your assumptions and the - you know, the nature of ambition and the nature of progress. Science is built on progress. It's always striving to learn more, to say more, to gain more knowledge and so on. And they are happy to be part of the progress of learning, but they don't see it as a goal in and of itself, and so they let you question some of your assumptions.
GROSS: Did you practice meditation when you were in the Himalayas with the monks, and did they teach you about meditation?
IMPEY: I wasn't a meditator before I went out there. I think I learned just by their example of how to think more calmly about things. The Buddhists talk about the monkey brain, and I can't pretend that my monkey brain, you know, settled down that much, but, you know, after three weeks off the grid living in a monastery, eating their very simple and slightly monotonous diet, enjoying the physical beauty and the smells of northern India - and the environment is incredible at the edge of the Himalayas - it has its effect. I mean, it percolates through to every part of you, and I think the net effect of that was meditative even though I wasn't actively meditating.
GROSS: You write that it's interesting to compare the Tibetan monks' attitude toward learning science to conservative Christian groups. I'd like you to make the comparison.
IMPEY: Well, it starts with his Holiness the Dalai Lama. He said famously, and in a couple of fora, that if science, modern science is found to disagree with the basic tenet of Buddhism, then Buddhism will change, and it's really hard to imagine those words coming out of the mouths of some religious leaders. That's an extraordinary openness to the inquiry that's at the heart of science, and so Buddhism, as I've experienced it and understood it, is a highly empirical thing. The Buddha, the historical figure, told his followers, don't accept my words as I tell you them. Like a metal smith would test the metal to see if it was pure, test my words to see if they are pure, to see if they agree with reality.
So it's a very empirical tradition, and that's what aligns it with science. So the openness of his holiness to dialoguing with scientists, to having science in the monastic tradition, is an extremely strong statement by him that he doesn't see science as a threat to his religion.
GROSS: He said if science is in conflict with Buddhism, then Buddhism will change. Has that been necessary yet?
IMPEY: It's been necessary or it's happened in the example I gave of cosmology where the Buddhist tradition has many cosmologies and some of them are pre-Copernican and archaic, but they're still taught in the monasteries, and so he's trying to change that. He's trying to make the teaching in the monasteries be consistent with physics, to be consistent with modern astronomy and to be consistent with biology. The Buddhist tradition has some rather intriguing notions of sentience and the boundary between living and nonliving things, and those don't really accord with modern biology, so that's changing, too.
GROSS: As a professor of cosmology and astronomy, do you ever see students who went to schools where evolution was not taught for religious reasons?
IMPEY: Definitely, and I've had students, you know, actually smart students come up to me at the beginning of the semester and say, look, Professor Impey, I know you're going to talk about the Big Bang and Old Earth and so on, and I just want you to know I don't believe that. You know, I'll answer the - what you want in the multiple choice tests or on exams, but, you know, you need to know that that's not my belief system. That's unusually forthright. Most students don't say that, but I know that 10 or 15 percent of them in the demographics of my classroom are likely to have been in a situation where they did not get the scientific theory of evolution.
GROSS: How do you deal with that as a teacher?
IMPEY: I think all you can do is present the information. I mean, you can't really proselytize, to appropriate that word. You can't - certainly can't attack anyone's belief systems. And that's - you know, that's an important part of teaching. You have to be respectful. But you can just say, look, this is what we think we know about the natural world, and this is how we know it. And it's based on evidence. And the evidence is shared. It's open, and that's how science works. It's a very open activity. And you can judge for yourself. And if you look at all the evidence and you look at the community of people who have accepted this evidence and drawn a conclusion from it, you know, it's your call whether you want to adopt that as part of your worldview or not.
GROSS: What's your reaction to schools that change the curriculum and eliminate certain chapters of scientific history because of religious principles and religious beliefs?
IMPEY: I think that's the very insidious thing that's happening. And, of course, the co-conspirators in some of that are the major textbook companies. If they want the Texas adoption or the California adoption, they will customize their textbooks to those large markets to satisfy what the school boards there have said, and that's really dangerous. And then all the way up to the Supreme Court, there's been validation for the idea that in the science classroom, you teach science. You don't teach a controversy that doesn't exist on a subject where there is no controversy scientifically. And in other classrooms which might teach religious studies or might teach anthropology or cultural studies, you can teach different views of human activity. But in the science classroom, you should teach science, and the Supreme Court has validated that view.
GROSS: What's the scientific question you'd most like to get an answer to or hear an answer to in your lifetime?
IMPEY: Well, astronomers are in this intriguing situation where they have this really quite robust model of the universe - how it started and how it evolved - and yet, we don't know the two major ingredients of the universe. And in my research, I work on supermassive black holes and indirectly on dark matter. And dark matter and dark energy amount to 96 percent of the material contents of the universe, where all the atoms and all the stars and all the galaxies are the other 4 percent. At the moment, we don't know what dark matter and dark energy are. So I would love to see those two issues resolved because they're huge. They're saying that we are ignorant of the bulk of the universe, as we speak.
GROSS: If you're just joining us, my guest is Chris Impey, and he's a cosmologist and astronomer and the author of the new book "Beyond: Our Future In Space." Let's take a short break, then we'll talk some more. This is FRESH AIR.
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GROSS: This is FRESH AIR. And if you're just joining us, my guest is Chris Impey. He's a distinguished professor at the University of Arizona where he teaches astronomy and cosmology. He's written several books. His latest is called "Beyond: Our Future In Space." And in addition to all that, he has also done a lot of research with these new telescopes that we're about to talk about, and he's made several trips to India to teach Tibetan monks in exile about science.
Let's talk about the telescopes that you work with. And you've worked with the Hubble and with other telescopes in that family. Would you explain what makes those super telescopes different from the kind of telescope that most of us have looked through?
IMPEY: Right. We'll start with the Hubble, which, well into its third decade, is still the preeminent astrophysics facility available to any astronomer. Some people forget that it's actually a pretty modest-sized telescope. It had to fit in the shuttle bay, which means it's just over 2 meters in diameter. And if you put it in a list of the world's largest telescopes on the ground or in space, it doesn't crack the top hundred. So it's a pretty modest telescope. What makes it extraordinary is the instruments that sit behind it gathering light and dispersing it into spectra and measuring infrared wavelengths as well as visible wavelengths.
So it's got extraordinary instruments, and it sits above the atmosphere. And the atmosphere is sort of the enemy in astronomy 'cause it blurs the light. It stops you from seeing sharply. It stops you from seeing deep. There's glow associated with the atmosphere. Even when the moon's not out, the sky is not completely dark because of the terrestrial environment. So when you're above all that in space, you can just do a lot better. And that's really why Hubble is still doing great stuff.
GROSS: What are you studying with these super telescopes?
IMPEY: So I tend to - I use our telescopes in Chile. So Arizona is a good place for ground-based astronomy. We have some dark parts of the state still. But even now, American sites are just not dark enough. So we've been putting large telescopes - 6-and-a-half meter telescopes in Chile. And we're building a huge 22-meter telescope which would be the world's largest. And Chile's the best place in the world, essentially, to do astronomy now. It's dark. It's high. It's away from city lights and any kind of perturbations. And I'm using those telescopes to study supermassive black holes in distant galaxies because it turns out that every galaxy has a supermassive black hole at its center, including our own.
GROSS: Now, when you're studying that with a telescope, what exactly are you doing? You're not literally seeing a black hole. What are you - what information are you getting?
IMPEY: That's right. You can see the black hole. The black hole itself is black. But what it does is it perturbs the center of the galaxy. It sends the stars screaming around on very fast orbits because of the gravity of this huge beast at the center. And by huge, we're talking hundreds of millions of times the mass of the sun. I think the biggest black hole in the universe is about 10 billion times the mass of the sun.
So that intense gravity drives the stars nearby and the gas nearby into extremely high velocities. And so that's what you look at with an optical telescope. You look near - as near the center as you can get, and you look for these very faster speeds and very high energies of that material near the black hole. And that sort of lets you diagnose the black hole.
GROSS: You've written that you've been able to snare light from near the beginning of time. What does that mean?
IMPEY: It means that these large telescopes are like time machines. As you look out in space, you look back in time because the speed of light, while very fast, is finite. And so we see the moon as it was a second ago, nearby stars as they were 10 years ago, the edge of the galaxy as it was 100,000 years ago and nearby galaxies as they were millions of years ago.
So the galaxies I study, we see light that has traveled for 5, 10, maybe 12 billion years, which is a big fraction of the age of the universe. So you are therefore looking back towards the universe when it was very young, and so a big telescope is turning into a time machine, lets you look back in time as close to the Big Bang as possible.
GROSS: Since you've seen what you've described as a hidden universe, do you often wonder what else is out there that is invisible to us?
IMPEY: Oh, absolutely. I mean, mostly what I wonder about 'cause one of my side interests is astrobiology is just what the possibilities of biology have been that really we can't detect right now. The Kepler satellite has essentially put a number on how many habitable Earth-like worlds there are just in our own galaxy, and it's an incredible number. It's 20 billion.
So each of those is a potential biological experiment, and most of them are so far away, we just can't make images of them. We don't know what's happening on those Earth-like worlds even though we know they exist. That's what I would love to learn about.
GROSS: So when you think about the possibility of life forms that might exist in distant galaxies, what kind of life forms do you think about?
IMPEY: I don't think we are almost imaginative or creative enough to understand what they might be like. We're inevitably conditioned by the culture - I've read science fiction. I love movies - "Star Wars," "Star Trek" - but they sort of acculture us to think anthropocentrically. We sort of tend to think of life that's a little bit like us or a lot like us. And the truth is, life could be so strange, we might not recognize it - certainly strange enough that we might not have real communication with it. So when you ask, how strange life might be in the universe, I don't think we know how to answer that question. And that's actually quite exciting.
GROSS: Why do you find that exciting?
IMPEY: Because I like the idea that we're not it. I like the idea that the universe - the boundless possibility of 20 billion habitable worlds has led to things that we can barely imagine. I think it's fun because it means your science is not self-contained and finite. It means that you have to really go out, way out, of the box even to imagine what astrobiology or life elsewhere might be like.
GROSS: What do you say to people who are kind of dismissive of problems we now have on Earth - environmental problems, climate change, wars - and say, well, soon we'll be out in space, and we'll start all over again?
IMPEY: Well, it's an important context for talking about space to not pretend that it's a solution to our problems. I mean, space is a brutally difficult and challenging environment. And only - what? - 500-or-so people have been in Earth orbit - a tiny, tiny, tiny fraction of humanity. So when you read about terraforming Mars - oh, we could transform Mars and make it habitable and then move there - no, we're not going to do that. We couldn't afford to. It would take an incredibly long time, and there's no way we could get more than a tiny number of people there.
So - and that applies to the Earth-like planets that we were talking about earlier. There's huge numbers of Earth-like planets, but the nearest one is probably going to be 20 light years away. At a tenth light speed, that's four generations to get there, and it's incredibly hard and expensive. So astronomy is just teaching us that although there are intriguing possibilities for living off Earth, our best solution by far is to take care of the home planet.
GROSS: Chris Impey, it's been great to talk with you. Thank you so much, and safe travels back to India in October.
IMPEY: Thanks, Terry. I've enjoyed it.
GROSS: Chris Impey is the author of the new book "Beyond: Our Future In Space." You can read an excerpt on our website freshair.npr.org. And if you want to catch up with FRESH AIR interviews you missed like last week's interview with the creator of "Mad Men," Matthew Weiner, check out our podcast. Coming up, John Powers reviews the new restoration of the three films known as "The Apu Trilogy" by Indian filmmaker Satyajit Ray. This is FRESH AIR.
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