‘No deliberate signals to aliens, but they can pick up our TV, radio waves’ - ex-head of SETI
The search for intelligent life beyond Earth has been ongoing for decades. Electronics scan star after star, planet after planet. But for now, the Universe has remained silent. What if one day, contact does happen? How will that affect humanity and our outlook on life? Are we even ready for such an event? And if there’s so many stars in our galaxy, why is nobody responding? We ask prominent astronomer and former Director of the Center for the Search of Extraterrestrial Intelligence Jill Tarter on Sophie&Co today.
Sophie Shevardnadze: Astronomer, former Director of the Center for SETI Research, Jill Tarter, welcome to the show, it’s really great to have you with me one more time. Researchers from the LIGO project have uncovered the existence of gravitational waves, detected from the merger of black holes, a merger that occurred over a billion years ago! What can these gravitational waves, this warping of space and time, uncover about those others that some are looking for in the Universe? Can they tell us anything about who’s out there?
Jill Tarter: Yeah. It’s not clear, Sophie, there’s some science-fiction stories that talk about using gravitational waves to send information, as the information channel, rather than radio or optical - we don’t actually have very complicated detectors yet. We saw the basic structure of a gravitational wave, but if there was any information encoded there - I didn’t see it. So, we learn more about the Universe, and that’s what this is all about, to try and understand the Cosmos, to try and understand our place within it, and to calibrate whether we’re unique or we’re one of many.
SS: So, from what I understand, gravitational waves, essentially, create ripples in space and time in the point that they pass through. If they’re a proven fact, does it mean they pass through us constantly? Does it mean we live in a world where space and time are constantly altered a bit?
JT: I think at some level it does. Whether the waves that are constantly passing through the Earth at a such a low level that we don’t yet have the sensitivity to detect them, is something that I don’t think we quite yet understand. It takes energetic events, but when you can see them over such large distances, you can expect that there are many energetic events and less energetic events which produce waves of smaller amplitude, different strains and on different timescales.
SS: You have inspired a book and a Hollywood blockbuster - Contact. In the past few years we’ve seen similar ideas portrayed in the movie Interstellar, the hero there enters a black hole, travels to other dimensions. Is this kind of mission far from reality, or you think it could be possible? Could the discovery of gravitational waves take us there?
JT: It might, it might, if wormholes turn out to be viable and we can manufacture them and keep them open at large enough scales - perhaps it is possible to connect two pieces of space-time together and shortcut the long timescales for travelling there under any kind of propulsion that we know about today, or even, for exchanging information at the speed of light. Wormholes could make it a much snappier conversation.
SS: SETI has been around for 60 years, listening to space, looking for signs of intelligent life out there. So far, nothing has been found. Are we just not capable yet? Perhaps 60 years is too early for a result?
JT: Well, you have to take that 60 years in the context of a Universe that’s almost 14 billion years old and our Galaxy which is 10 billion years old, and our Solar system, which is 5 billion years old. So, when you’re thinking about those kinds of timescales, 60 years isn’t very long. Our technologies are getting better much faster. We started out using tools that the astronomers have built, and they weren’t ideally suited for this kind of search. We’re now building our own tools. They’re better suited, we think, to find at least certain types of signals, and those tools are getting faster all the time, so… we haven’t done a lot yet, but when you’re riding an exponential curve, all the good stuff happens at the end, right? The last doublet.
SS: Like you’ve said, for 60 years SETI has been around but the technology has changed drastically, what are the latest innovations the firm is using to find aliens?
JT: Well, we’re using radio telescopes and optical telescopes, looking for signals that are artifacts, that look very artificial. So, in the radio, we’re looking for signals that are compressed in frequency, that show up only at one channel on the radio dial, for example. In the optical, we’re looking for time compression, we’re looking for very bright pulses that could be generated by a laser out there. Right now, because the computing power is finally becoming available and affordable, we’re beginning to look for radio signals that have a characteristic that’s broader band, that could contain more information.
SS:What kind of signals are we sending out to them? What kind of language, or code do you use to send such signals? What is the universal language - literally?
JT: We’re guessing that mathematics might be a universal language, because we think it needs some kind of math to build a transmitter or a receiver, and except for a few experiments that have been done in your country, and a couple of stunts that we’ve done in the U.S., we’re not actually sending deliberate messages. We are sending out signals from our television and radio broadcast, from our radar systems around the airports. So, we’re leaking information, but we’re not deliberately transmitting yet.
SS: So SETI is trying to detect traces of some kind of signals sent by extraterrestrials. Why do you think they will use technology that produces radio frequency or will be visible and detectable, etc? I mean, are we attributing human behaviour to something we have zero understanding of?
JT: In some sense, we are. On the other hand, we are here in the XXI century and we have the physics that we understand and the technology that we’ve invented. That’s what we have as a toolset, we can’t do anything else until we figure out some new physics and some new technology and then, if that makes sense for interstellar communication - we’ll we start to do that. So, we’re actually using the tools that we have, and hopefully there is a lot of commonality with the laws of physics and chemistry elsewhere, and the technologies that might be invented for exploring the Universe, by us and by them.
SS: Do you ever feel like, maybe, you’re imagining humans all the way more advanced instead of imagining aliens?
JT: Yeah, right. Earthlings on steroids, perhaps. But, tell me, Sophie, how would we go about trying to detect something that we can’t conceive of?
SS: I don’t know, I was going to ask you - how do you find ways to look for something you have no idea about?
JT: Well, we think about it a lot, and so radio telescopes and optical telescopes and in the future, infrared telescopes, make a lot of sense, because we know that information, at least signals, can travel across the entire Cosmos at some of these frequencies. We can see very far distances using this technology. But, we also think about, well, what other technologies have we invented? Well, we’ve just detected gravitational waves and some people, some very far thinking writers have suggested - maybe it’s gravity waves that will contain information encoded in it, or maybe it’s neutrinos that are carrying signals? These are much harder for us to detect at our current level of technology, but we’re at least talking with our colleagues and we say - hey, if something anomalous shows up, give us a shout, because maybe it’s some indication of someone else’s technology.
SS: So, the Universe is 14 billion years old, and then distances in the Universe are also immense. I mean, if SETI does detect a signal it is likely the messages will be very old as well, I mean, they’d come from a civilisation that may be extinct. I know SETI has been called the ‘archaeology of the future’ because of that. What’s the point of looking for a signal so hard only for it to be a million years old?
JT: Well, it still answers the question about whether anywhere and anytime, anyplace else, chemistry and physics created some kind of life and that life developed technology. So, it answers the question about other sentient beings in the Universe. It doesn’t necessarily say that they’re there now, although the likeliest place for us to receive a signal from is within the Milky Way Galaxy, this galaxy that we live in, actually, out in the kind of boondocks, at the edge of the galaxy, and there are 400 billion other stars and more planets than that in this galaxy, and that’s a 100,000 light years across. So, a signal that we detect from within the Galaxy, again, the easiest thing to do, will be less than a 100,000 years old, and if they’ve managed to become an old and advanced technology, I think that they’ll still be around for the 100,000 years after they send that message, or maybe the message is a cry for help, right? Help!
SS: You’ve told me once that if aliens were out there, they wouldn’t contact us. Maybe they don’t want to be detected. Is there still a point in searching for them - I mean, will we ever find them if they don’t want to be found?
JT: If their technology is more advanced than ours, it’s a possibility that they could hide. On the other hand, there are so many things that we use technology for today that create leakage radiation. It would be a pretty large technological challenge to enclose that in some sort of impenetrable barrier so that all that leakage would stay capture at home. It’s always possible, I mean, if they have more capability than we do, then they can do things that we can’t do ourselves.
SS: But let’s say they are hiding, right? Could they be hiding from something, could there be some kind of a threat, something to avoid?
JT: Right. Well… you know, this is alien psychology. First of all, we don’t even know whether any other intelligent species exist out there - that’s the question we’re trying to answer. In terms of their motivations, that’s yet another level of abstraction. What would life be like, that isn’t life as we know it? Are there any universals that come along with being intelligent? You have to remember, we call this the search for extraterrestrial intelligence, but what we’re really looking for is technology. That’s the only proxy we have for intelligence. So, a differently evolved species, somewhere else with perhaps the same or different physical conditions. What could possibly be universal? We’re really curious to know and we really haven’t got any data that can help us to answer this question.
SS: I know that we don’t have any data, but I mean, if you spent most of your life looking for intelligent life somewhere deep inside, you must think they do exist out there, right? So, do you think they’ve been to our planet? I spoke to Canada’s former defence minister once - I don’t know if you know anything about him - he told me aliens have not only been here on earth, but that they’re participating in the course of human history, advising the Pentagon and all sorts of things. Do you think it’s a stretch too far?
JT: Yeah, Sophie, what data, what evidence did he show you? I mean, it all comes down to - what’s the proof? You can make extraordinary claims, but if you can’t back it up with data and evidence, then it shouldn’t be believed. So he’s telling you something rather spectacular, and should have been willing to back it up with hard evidence. So, until I see that, then I’m not convinced, sorry. In terms of… there’s so much that we don’t yet understand. Our astronomers look out and they build a new instrument with some new capability, and they tell their funding agencies: “Well, yeah, it’s going to solve this problem and that problem and the other problem”, and that we have a great history in astronomy, that what these new telescopes and instruments do - is show us something that we didn’t expect at all. So, I’m asking questions, and I don’t know what the answers are going to be. I can say that over my career exoplanets, which we now know are there in abundance, and extremophiles, life on these planets, living in conditions that we once thought couldn’t possibly support life - those two things have made the Universe up here more bio-friendly, over the course of my career. Whether it actually is or not, that’s question we’re trying to answer.
SS: Let’s do some more alien thinking, alien psychology, just because, you know, the amount of thinking you’ve done about it is incomparable to mine, so I’m sure your capabilities of assuming things are way beyond mine. So, if aliens show up on Earth one day, are you afraid maybe things are not going to go very well? What if instead of, like, “we come in peace, take us to your leader” they’ll say “bow down to your new overlords”? Whether they come in form of evolved beings or in form of technology…
JT: Well, actually, Stephen Hawking a few years ago on this television show made exactly that point. He used the analogy of Christopher Columbus landing in the New World, and it didn’t work out really very well for the natives. So he cautioned us to be fearful and my take on that is… look, if they can get here, their technology is far more advanced than what we have. It probably means they’re a lot older than we are, and I don’t know how you can get to be an old technological civilization without somehow evolving past the aggression that was probably part of you becoming intelligent. So, Steven Pinker at Harvard has written a book in which he argues that humans today are kinder and gentler than we have ever been, and this is a cultural evolution, that trajectory will probably continue. So, I think, an old technology has figured out how to manage a population, how to shepherd and steward a planet and take care of things on a long timescale. So, perhaps they are no longer aggressive. Or, maybe, Stephen’s right, maybe it’s the s-o-b-s that jump in spacecraft and come and take over our world.
SS: But, is humanity ready to see aliens? We can barely learn to live with versions of ourselves with different skin colour or accent, how do you expect us to be accepting of another species altogether?
JT: Actually that’s one of the greatest things about SETI. If you take this seriously and you think about what we’re talking about, we come to the conclusion that we are all the same when compared to someone else, a differently evolved species from another world. We, Earthlings, are all the same, and that perspective has the ability to trivialize the differences among humans that we shed blood over today. So, the fact that they’re so different leads me to the conclusion that it’s a lesson of how much alike we all are.
SS: So, you think that will consolidate us, on a contrary?
JT: I think it might, yes. At least, even thinking about it, even if it doesn’t happen, if we can get the world thinking about it, with this different point of view, this different perspective about who we are on this one planet - I think it could have a huge impact for the good.
SS: Astronomer Andrei Finkelstein claimed in 2011 humans will encounter life in the universe in just 20 years time. What do you think of this claim?
JT: That claim has a lot of momentum behind it in terms of all of the exoplanets that we are discovering - of many different types, and the fact that we are building tools that aren’t ready yet, but certainly in the timescale of a decade or two, will be, and then these tools will be able to actually inspect some of these distant planets and do an essay of their atmospheres, to try and figure out their chemistry of the atmospheres around some of these planets, to see what the chemical composition is, and to see if there are any biosignatures in those atmospheres, if those atmospheres have a chemistry like our atmosphere on Earth does, which has trace elements that indicate that there’s life on the surface of this planet - so these biosignatures… We haven’t got our act together yet, we can’t tell you for sure - there's a smoking gun, that if you see this in the atmosphere, you know there’s some kind of biology on the surface, but we’re working very hard on that. The capability to make those investigations is going to be with us in 10 or 20 years. I think that’s the basis of the claim - that, if there’s life out there, we’ll be able to detect it in a short timescale. That’s just life, that isn’t intelligent life or technology.
SS: So more than one planet that have the potential to be Earth has been discovered - places with cool-sounding, catchy names like Kepler-186f, or Kepler 452b - does SETI work with NASA on this, do you turn your listening devices in the direction of newfound Earth clones? Do these discoveries make you optimistic?
JT: Oh yes, absolutely. The Kepler spacecraft has just proved to be spectacular in its ability to detect exoplanets, and now we have somewhat over 5,000 exoplanets that have been discovered, and candidate exoplanets - and yes, once Kepler and the other radial velocity and gravitational lensing detectors began to publish these results, those went to the top of our list as targets to look at with our SETI telescopes.
SS: Jill, you know, I thought to myself often - what would I ask an alien if I ever encountered it. I’d say, “Do you believe in God?”, because I really want to know if they believe in God. What would you ask an alien if you were to meet him?
JT: Actually, my question would be - how did you manage to grow old? How did you get through the technological adolescence that we find ourselves in at this point on this planet. How did you manage not to do yourselves in? How did you manage not to destroy your environment? How did you do it?
SS:Jill, thank you so much for this wonderful interview. We wish you all the best, with all your future endeavors. We were talking to Jill Tarter, the past director of the Center for SETI tasked with the search of extraterrestrial intelligence, discussing the progress in the search for extraterrestrial life and if we will ever be able to make contact with alien civilizations - hopefully. That’s it for this edition of Sophie&Co, I will see you next time.