IRA FLATOW: I’m going to actually make this even more complex–

JILL TARTER: Thank you.

IRA FLATOW: –and more interesting because I’m going to bring on a seasoned astronomer– someone who’s been investigating that same expanding universe, but in a different way. Jill Tarter has spent the last 35 years searching for the signals that would answer one of the most profound questions of our time– are we alone in this big expanding universe? Is there are other intelligent life out there?

And her commitment to that search has earned her two public service medals from NASA, a 2009 TED prize and a spot on the big screen. You may recall, her work was the inspiration for the movie Contact, in which Jodie Foster played a scientist searching for intelligent life in the cosmos. She’s the Bernard M. Oliver chair for SETI research at the SETI Institute in Mountain View. Welcome back to Science Friday.

JILL TARTER: Thank you very much, Ira.

IRA FLATOW: How many times a day do you get asked about Jodie Foster?

JILL TARTER: Oh, not enough.

IRA FLATOW: Not enough. OK.

JILL TARTER: It was a great pleasure to work with that very smart lady.

IRA FLATOW: Yeah. Tell us, where are we in the search for extraterrestrial life?

JILL TARTER: Well suppose, Ira, that your question was are there any fish in the Earth’s ocean? OK. Not is there extraterrestrial intelligence, but are there any fish in the Earth’s oceans? Here’s an experiment I’m going to do. I’m going to take the glass of water that you have down on the floor– about eight ounces– and I’m going to actually take the empty glass and dip it in the ocean. And I’m going to look to see if I caught any fish.

That experiment could work. There are fish that would fit in there. But if I didn’t see any fish, I might be unwilling to conclude that there are no fish in the ocean.

IRA FLATOW: Right.

JILL TARTER: Well that’s where we are with SETI. If you take the entire phase space– this entire multidimensional space that we can envision some evidence of someone else’s technology existing in– and you say that volume is equal to the volume of the Earth’s oceans, what we’ve done so far is explore one eight-ounce glass.

IRA FLATOW: Wow. Does listening to what Saul Perlmutter does about expanding universes give you hope that there is more life?

JILL TARTER: Well actually, let me be a little bit of a spoiler here. Let me remind you that Arthur Clarke once said that any sufficiently advanced technology would be indistinguishable from magic. Might it be indistinguishable from dark energy? Might what you’re seeing actually be some manifestation of an extraordinarily advanced technology?

SAUL PERLMUTTER: I think it’s a completely fair question. And since we’re still trying to figure out just these baby step understandings of the cosmology that we live in, and we know that each of the major steps we’ve made has introduced some new story part into the story, we’re still open to the possibility that there’s something else even more extraordinary in the story. Now you know, I think that–

JILL TARTER: It wouldn’t be your first choice.

SAUL PERLMUTTER: I was going to say– to be honest, I’m more worried that I’ll never get a chance to explore what some other intelligent life is doing in the universe. And so I think that would be wonderful, but if I had to make a bet, I guess I would give it less odds.

IRA FLATOW: This is Science Friday from NPR. I’m Ira Flatow talking with Jill Tarter and Saul Perlmutter. Jill, you no longer are doing the active search yourself, right?

JILL TARTER: No, I’m doing what’s absolutely necessary for the search, which is trying to find money to continue.

IRA FLATOW: Ah, yes. We know all about that, and Science Friday also. Yeah. And how does the search happen? Describe how the search is actually done.

JILL TARTER: Well at the moment, there are two technologies that we’re using. We’re using optical telescopes and radio telescopes. And both techniques are looking for signals that represent something that nature does not appear to be able to produce. So if we find them in the optical, we’re looking for very bright pulses of light that last a nanosecond– a billionth of a second or less.

In the radio, we’re not looking for time compression. We’re looking for frequency compression. So we’re looking for radio signals that occupy only one channel on the radio dial– where nature spreads its energy over multiple channels. It doesn’t seem to be able to be this coherent. So if we find either of those artifacts, we can presume technology, or maybe it’ll turn out to be some sort of astrophysics that we didn’t think was possible, but in fact, is.

IRA FLATOW: Were both of you always interested in physics and astronomy and science when you were kids? Did you have a mentor? Did you have someone who encouraged you as a youngster?

JILL TARTER: Well I decided, at age eight, I was going to be an engineer. It was kind of a thing because the only engineers I knew were men. And I said, damn it– women can be engineers too. And that’s the way I went.

AUDIENCE: [APPLAUSE]

JILL TARTER: And I was helped by the fact that Sputnik came along and suddenly we needed more scientists and engineers. And well, OK– some of them can be women, right? So I went that direction. I soon decided that the more interesting questions were in the realm of physics and astrophysics.

IRA FLATOW: Saul, you?

SAUL PERLMUTTER: I guess I was one of these kids who wanted to know how everything worked. And I think I remember feeling like, here we were in this world where we seem to be held up by the floor and we don’t fall through. And you would imagine somebody would have given us an owner’s manual that there should be some instruction book that goes along with all this.

And I remember thinking that everybody would need that owner’s manual and I, little by little, started realizing that, OK, most people– and including myself– eventually managed to live in a world where we don’t get to know how it all works in some deep level. And yet, I still wanted to know, what could you actually learn?

IRA FLATOW: Yeah. Let me see if we get a quick question from the audience before we go to–

AUDIENCE: I’m kind of interested– going from a very small to very large– how do you describe the mathematics of the infinite. Going very large, I can see powers by powers. What does it mean to go infinitely small and how do you mathematically calculate that backwards trace, back to the infinitely small?

SAUL PERLMUTTER: I mean, this is one thing, of course, that mathematics makes really easy. I mean, it’s very easy just to write down a larger number in your exponents, and you could go big by writing 10 to the 120, as I just did. You can go small by writing 10 to the minus 120, right? So that it’s trivially easy for math.

But what’s interesting is that, what the theorists have started to do is actually ask questions like, can you go infinitely small, or will turn out that there is some limit and that you actually have to consider a world in which the smallest units are of a finite size– very, very tiny, of course– and so there are theories now that are being built on that very question. How far can you take it to the small? So far, I have not heard theories worrying about how far you could take it into the large, because we know that we’re limited by how long it takes for the universe to let light reach us.

IRA FLATOW: All right, we’re going to have to break there and take a break. We’ll come back and talk lots more about the universe– the extra big, the extra small, the search for life. Stay with us. We’ll be right back with Saul Perlmutter and Jill Tarter– sorry for my cold today– after this break. Stay with us.

This is Science Friday. I’m Ira Flatow. We’re talking with Jill Tarter, chair for SETI research and with Saul Perlmutter, a Nobel Prize winner in physics, about the search for extraterrestrial life and about expanding universes. And Jill, we’re finding all these exoplanets now– planets around other stars. Does that increase the odds that we might find?

JILL TARTER: Well I think that’s been a game changer. Until the early 90s, we didn’t know whether any other stars would have planets and life– at least life as we know it– appears to be a planetary phenomenon. So now the fact is, we know there are other planets out there. It looks like almost every star probably has planet or two or three. And that means that we can redirect our search with the radio telescopes. We’re no longer just trying to figure out– hmm, that star might be a good host for planets. We now know there are planets there. So that’s where I point my radio telescope.

IRA FLATOW: Could there– now the planets are so far away. Could you find this civilization, that the signal takes so long to get here that it no longer exists– the civilization itself.

JILL TARTER: Well, if we’re going to detect a signal, it’s going to be because, on average technologies– and that’s really what we’re searching for. Technology is our proxy for intelligence. If we’re going to find a signal– be successful– it’s only because technological civilizations survive for a very long time. And so when you’re talking about a long-term survival, the fact that it could take up to 100,000 years for a signal to cross from one side of our galaxy to the other is in fact, not a very long time. And if they were there to send the signal, they’re probably still there.

IRA FLATOW: All right. Let’s go to the audience for some questions. Yes, sir.

CARL HEWITT: Carl Hewitt from I Robust. My question is about the politics of SETI. And that is, what do we understand about why they might want to communicate with us? To take your fishing analogy, if I were a very smart fish out there, I can see why I’d be very motivated not to be detected by the humans on this planet.

AUDIENCE: [LAUGHTER]

JILL TARTER: What do we know about extraterrestrial politics? Absolutely nothing.

AUDIENCE: [LAUGHTER]

JILL TARTER: There may be no one else out there. We may be alone.

SAUL PERLMUTTER: Or they might not want to be detected by us.

JILL TARTER: That’s also possible, or it might turn out that, as one tries to go from being an emerging technology– such as we are– to being an old, stable technology, there might be a real problem. We might have a bimodal distribution. We might have a lot of young civilizations– technologies– and a few that made it to be old.

And perhaps learning about the old technology and the fact that they survived, when you’re a young technology, might help you get through. And so maybe there’s some prime directive that says, for the good of the emerging technologies, we should make ourselves known. I don’t know. Your scenario could be just as correct.

IRA FLATOW: Or maybe, as Carl Sagan used to talk about, people are finally listening to I Love Lucy someplace out in another star. Things are leaking out that we didn’t think about.

JILL TARTER: Absolutely. And we have this bubble of information about us that is expanding one light year per year. This radio broadcast is going to leak off this planet and four years from now, it will reach the nearest star. But we’ve only been doing that for, again, a short period– 100 years. We have a galaxy that’s 10 billion years old. We have– so they’d have to be pretty close to us–

IRA FLATOW: And that’s–

JILL TARTER: –in order to have found us.

IRA FLATOW: –what’s fascinating about the recent exoplanets, is that they are so close, that if they had intelligent life, we could communicate in two ways within one of our lifetimes, could we not?

JILL TARTER: Yes. There are certainly planets that are close enough to have detected our early radio signals, television broadcasts and transponded back.

IRA FLATOW: All right. Let’s go to a question here. Yes, sir.

AUDIENCE: Yes, I’m Ross, and I was wondering about the Fermi Paradox, which I believe, says something about, if they’re out there, why aren’t they here? And if our guest could comment. Thank you.

JILL TARTER: Let me paraphrase what the Fermi Paradox is. Fermi postulated that if there was ever another technological civilization within our galaxy– any time, any place– that obviously that technology would quickly, in terms of Galactic lifetime, have developed the ability to travel between the stars. And they would do so and they would colonize the galaxy, in a time very short compared to the lifetime of the galaxy. But they’re not here and therefore, when you phrase this as a paradox, the only solution to that paradox would be to say, there could never have been another technology any time, any place. We’re the first.

If, indeed, you can make that statement– set it up as a strong paradox– then you’re entitled to a strong conclusion. But I would claim we can’t say that they’re not here. And I’m not talking about alien abductions, and medical experiments, or any of that pseudoscience. What I’m simply saying is we have so poorly explored our local environment, that they could well be here, even if you’re talking about big wet biology, boldly going in starships. Yeah, there are a couple of places in our neighborhood– the Lagrangian points– where we’ve looked and could probably rule out bright shiny Battlestar Galacticas.

But we certainly can’t rule out small, dark things. We just got, in February, surprised by a big rock– 20 meters across– that came into the atmosphere at Chelyabinsk and surprised the hell out of everyone. There was another rock that, in the same time frame, that we knew was coming. But we don’t– when we can’t find 20-meter rocks coming right at us, think about how little we know about our local neighborhood.

IRA FLATOW: And how much of the ocean there is– that could land in and we never see them– is the Earth. Yes. You have a question ma’am?

AUDIENCE: Hi, I’m Kerry Ann. I’m a student here. I was wondering if there’s any program sending out signals that are systematically trying to contact other civilizations that might be out there– whether it’ll be 100,000 years from now– that they’ll get them, beyond just our radio and TV shows?

JILL TARTER: So we have leakage radiation. But we don’t have any systematic transmission, and that’s because we’re not real good at 10,000-year plans.

AUDIENCE: [LAUGHTER]

JILL TARTER: If you’re going to transmit, it does no good to transmit for two years because your signal will reach an intended audience– and go by them in a two-year period– they’d have to be looking at you in just the right way at just the right moment. So if you take transmission seriously, you’ve got to be in it for the long term, which means I think we have to grow up before it’s time to transmit. I think it’s an easier job to listen. We should listen first and then as we begin to have the capability to take this long look at the future– which we need to do for so many reasons, for so many other challenges on this planet– transmission might be in our future.

IRA FLATOW: Let me give you both the blank check question I give to a lot of my guests, and that is, if you had unlimited funds– if you had a blank check, Jill, and you want it to continue and give up raising that money, because you have the money now and you now could spend it– what would you do with it? What do we need? What technology, what ideas– what would you do with all that blank check?

JILL TARTER: Well actually, my check is rather modest because I can’t claim to tell you that I know exactly what the right thing to do is. I can tell you that a few to $10 million a year could be very well spent, expanding the kinds of things we know how to do. But what if the right thing to be looking for– and I’d love to have that money, by the way. I mean I’ll take your check.

IRA FLATOW: I have the check in my pocket.

JILL TARTER: OK. But I wouldn’t spend huge amounts on it. I wouldn’t because we can’t guarantee success. It might be zeta rays that we should be looking for. I don’t know what zeta rays are.

IRA FLATOW: I was going to ask you. I missed that one.

JILL TARTER: Yeah, right. Right. But it’s a technology we haven’t yet invented. It’s the kind of physics that Saul is going to eventually lead to our understanding thereof. And then we’ll be able to build the zeta ray technology and use it, and we will. I mean, we always reserve the right to get smarter. So we’ll keep doing what we know about, wanting to be able to do in the future, adding things we don’t yet know about. So my check is fairly modest.

IRA FLATOW: Yeah. Is yours is yours modest, Saul?

SAUL PERLMUTTER: Well, I have one reasonably modest one, if you count a new space telescope. There is a– for a long time, we’ve developed a plan the– community has developed a plan– for what’s now called WFIRST, which was astronomy’s top priority– decadal survey– which is basically a much, much wider field Hubble Space Telescope. You can actually see a much larger fraction of the sky at one time. And we know that would allow us to take the next big step forward towards exploring dark energy.

But I think your big check version actually comes back to saying, I think, would be more what Jill’s saying, which is that we just have to make sure that we keep the basic science coming, so that we keep inventing the next way of thinking about the world. And that’s going to help us to do the long steps.

IRA FLATOW: So you know what those zeta rays are when you find them. Yes?

ALEX MANGUM: Hi, my name is Alex Mangum. How do we know that they can receive the radio signals? How do we know that they don’t have a different type of technology?

JILL TARTER: Well actually, that’s a question that we were just discussing. We don’t know what the right technology is. We can assume that a civilization, when it begins to develop technology, will want to explore its universe. And they might develop optical telescopes, and radio telescopes, and infrared telescopes, and X-ray telescopes, and all the other wonderful things we do to explore the cosmos.

And then we look within what nature does, and we try and find ways that you can transmit information over interstellar distances– the simplest answers– and we presume that their physics is the same as our physics, and that in their quest to explore the universe they live in, they will possibly have invented what we have.

If they haven’t invented it yet, if they’re younger and less capable than we are, then we can’t detect them over interstellar distances. We’ll detect civilizations that have more capability than ours– that are older than we are.

IRA FLATOW: This is Science Friday from NPR. Yes, ma’am. Up there at the microphone– you’re next.

AUDIENCE: Hi, my name is Shannon. I was wondering– speaking of big rocks coming toward the Earth, there is an organization that has asteroid detection and deflection with–

JILL TARTER: B612.

AUDIENCE: –former astronauts– B612, right– with Scott Hubbard and Ed Lu. Are you working together? And also, Ira, when will you have them on the show?

JILL TARTER: I’m cheering them on.

IRA FLATOW: We’ve had them on. We’ve talked to astronauts. Yeah, we’ve talked about asteroid detection and deflection and–

JILL TARTER: Yeah.

IRA FLATOW: Are you working with them?

JILL TARTER: They’re very good friends, and I’m cheering them on because they’re also out there trying to raise money for their spacecraft. Yeah, the dinosaurs aren’t with us anymore because they didn’t have a space program. We would be foolish to go the same way. I’m looking for every way we can to make sure that we actually have a long future. And I see SETI as an investment in that long future.

IRA FLATOW: Saul, before we go– we have a couple of minutes left– as a Nobel Prize winner– you as a Nobel Prize winner– I’d like I like to know what’s the best perk you get– benefit you get– winning a Nobel Prize.

SAUL PERLMUTTER: There’s no question that the single biggest perk that you get is a parking spot right in the middle of campus at the university. growing up in a big city, that has got to be the ultimate.

IRA FLATOW: For life, huh? You get it forever?

SAUL PERLMUTTER: Oh, yes, at least as far as I know.

AUDIENCE: [LAUGHTER]

IRA FLATOW: You haven’t checked today.

SAUL PERLMUTTER: That’s right.

IRA FLATOW: That’s great. I think we have time for one more question.

AUDIENCE: So I’m thinking about the Big Bang, and is there another metaphor that you would use instead of the Big Bang? If the balloon doesn’t work and the Big Bang doesn’t work, what would be a better metaphor?

SAUL PERLMUTTER: Well I was joking when I said the Big Soup, and I think that in some sense though, that when you go back in time, that’s about as far as we know, that the period that we can actually talk about is a period in which things were very, very dense and right on top of each other. And I don’t think it’s going to catch on, to be honest.

IRA FLATOW: Certain reason the Big Mulligatawny just doesn’t have the same–

AUDIENCE: [LAUGHTER]

JILL TARTER: Clam chowder– the universe.

SAUL PERLMUTTER: Not that it has to be a lumpy soup, because we have to be able to form things where the lumps are so we get to be here eventually. So it’s–

JILL TARTER: Cosmic clam chowder?

SAUL PERLMUTTER: Yeah, exactly. It’s–

IRA FLATOW: Cosmic clam chowder.

SAUL PERLMUTTER: It can’t be consomme. It has to be more of a clam chowder. Yeah.

IRA FLATOW: Yeah. Yeah. But it is something that it’s hard for people to grasp that you could have something from nothing, that empty space is not empty really, right?

SAUL PERLMUTTER: Now that’s right. I mean, that aspect itself is mind-boggling to begin with– that we can’t actually have an empty space. We have this very busy, boiling turmoil of what we ordinarily would consider to be completely empty. Of course, when it comes down to it, even if you get back to that first instant in your description– you call something a Big Bang or a Big Soup– that begs the question. Because it doesn’t get to– what we really want to know is, how do we get that soup? And I think that maybe when these– well we don’t know if it’s an endless question.

IRA FLATOW: And that is something everybody’s been trying to think about for years. I mean, everybody’s been trying to answer that question– where did it all begin?

SAUL PERLMUTTER: I almost imagine that it might define what it means to be a human being, that you walk out of your cave at night and you look up at the stars and you find yourself asking that and Jill’s question.

IRA FLATOW: Well I want to thank both of you for taking time to be with us today. We’re happy to allow you time to talk to our audience and to think about what the future is and where we’re going, where we came from. These are certainly questions you hope that people think about, right? I mean, you don’t have trouble explaining it. You don’t have much trouble. Is it easy for you to explain this whole idea of dark energy?

SAUL PERLMUTTER: Well as you can hear, it’s almost trivial. It’s–

AUDIENCE: [LAUGHTER]

IRA FLATOW: All right. We’ll leave it with that. Thank you, Saul Perlmutter. He is a Nobel winner in physics and professor of physics at U.C. Berkeley, also senior scientist at Lawrence Berkeley National Laboratory. And also with us is Jill Tarter, chair for the SETI research at the SETI Institute in Mountain View, California. Thank you, both–

JILL TARTER: It’s been a pleasure.

IRA FLATOW: –for taking the time to be with us today.

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