If aliens landed in the White House Rose Garden tomorrow, they’d have some explaining to do…and the person they’re most likely to try explaining it to is Paul Davies, chair of SETI’s Post-Detection Task Group since 2005. As we discover more and more Earth-like planets (including the celebrated Kepler 186f, the first Earth-size exoplanet found in the so-called “habitable zone” around its star) bring questions about the origins of life newly into the media forefront, we asked Paul to elaborate on the odds of finding life out there, what forms it might take, and the one question he’d ask the aliens.
The following is a lightly edited transcript of an audio interview from 4/24/14.
WSF: Can you tell us a little bit about the mission of the SETI Post-Detection Task Group and how it was set up?
PD: The task group was set up by the International Academy of Astronautics, about I think fifteen years ago. And the previous chairman of this group, Ray Norris, a radio astronomer in Australia, approached me to see if I’d be interested in taking it over, and I said yes, and I’ve been doing it ever since.
This is a task group with a very big vision and a very small budget—in fact, a zero budget. The constitution of this task group is fairly flexible, but it’s a mixture of scientists and media people and a couple of lawyers, and we have a priest, and a couple of science fiction writers. Its function is to deliberate on what to do next in the event that we obtain some pretty incontrovertible evidence that we’re not alone in the universe.
Now, I think everybody realizes that if we were suddenly to, say, pick up a message from E.T., all bets would be off, and so the protocol that surrounds this particular task group may in practice count for nothing. But what should happen is that in the event of, say, a signal being picked up—or some other definite evidence that we’re not alone—the plan is that they should inform the task group, as well as a number of other bodies including the United Nations and the government of the country in which their equipment resides. Thereafter, it’s supposed to proceed according to some systematic plan.
I think the problem, in my view, is that we can only just guess what we might be dealing with, and so the main function of the task group is to act as an advisory body, and to anticipate the sorts of issues that might arise, in the event that this really did happen.
WSF: Do you feel there’s a good consensus around what a plan would look like?
PD: Well it was conceived at the time when everybody was thinking in terms of “radio SETI,” that is: the people who sweep the skies with radio telescopes in the hope of stumbling across a message deliberately beamed at Earth by an extraterrestrial civilization. Then it’s fairly easy to see what the issues are, because there are various sorts of messages we could imagine. One of these might simply be ‘Hello, I’m here,’ and another might be a message with content. For example, in the science fiction story that Carl Sagan wrote called Contact, this was not just a message, there was actually some transformative technology. And then one might go whole hog and imagine it might be a message that not only invites us to enter into a dialogue, but actually gives us the password to Encyclopedia Galactica or something like that, in which case, it’s very hard to imagine that anything would ever be the same again.
I think that’s the least likely scenario. It seems to me that if we do get evidence that we’re not alone in the universe—that there are or have been other civilizations out there somewhere—that this would most likely come about because of some indirect signature of nonhuman technology. And I see that as being not something that would be clear overnight, but that would result from accumulating evidence over a long period of time. Something about another star system perhaps, or from analysis of radio signals or any other scientific database—and we should be as broad as possible—that sort of ‘looks fishy.’ And then a lot of people would say ‘oh, well, you know, I can think up a perfectly natural explanation,’ and some would say “well maybe not,’ and then this would go back and forth and back and forth.
Think of the Higgs Boson, where there was a hint of a bump in the data, but people weren’t completely convinced, and then they had to collect more data, and sit down and analyze it, and slowly over a period of years, it became clear that this was a real discovery. I think it would take much longer in the case of discovering some sign of alien technology. It’s most unlikely that we’re going to come across a crashed spacecraft, or a powerful message sent straight to our receivers. I just think that scenario’s so very unlikely; we would have probably a rather long period of time of “maybe” this is evidence, when the debate could be widened.
Because this task group is only an advisory body, I think the only really contentious issue is that if we did have very clear evidence of a civilization, say, orbiting Star X, should we then be proactive in attempting to contact that civilization. I personally would feel very uncomfortable with any Tom, Dick, or Harry out there commandeering a radio telescope and sending their own cosmic homespun wisdom on behalf of mankind, without any proper broad-based deliberation. But that is a difficult issue, because of course we can’t stop people from doing that. I just think nobody has the right to speak for the whole of mankind, even supposing the aliens could make any sense of what they were picking up.
WSF: What about non-intelligent microbial life…Does that interest you, in the context of SETI?
PD: My interest in astrobiology is far broader than SETI…I also have a major research program on the origin of life, and a big research group here at ASU working on the theoretical aspects of the origin of life; we’re also part of a much bigger astrobiology program at ASU that is tied to the NASA Astrobiology Institute. And so I’ve been involved, over the years, particularly on the origin of life but also in the question of the transfer of microorganisms between Earth and Mars, and impact ejectors. That’s something I suggested in the early 1990s and everybody laughed at me; now it’s the party line, meaning if you get life on Mars you’ll get it on Earth pretty soon after, or vice-versa.
These two planets have intermingled materials throughout their lifetimes, and if there is any life on one or the other that’s going to get intermingled too. So that complicates the whole story about looking for life beyond Earth, because if we find it on Mars—and I’m thinking microbial life only—chances are it’s the same life we know and love. What we’d really like to know, is ‘Is the emergence of life from non-life a very likely event or a very unlikely event. And we haven’t a clue, because we’ve no idea how it happened! If you don’t know what the mechanism is, you can’t work out the odds.
The fact there are all these Earth-like planets dotted around the galaxy and beyond matters not a jot if the transition from non-life to life is incredibly rare, incredibly improbable. One approach to this is we try to detect indirect signs of now non-intelligent life going around an extra-solar planet going around another star, and for example if we found oxygen in the atmosphere of one of those planets, it would be a strong indicator of life. Another would be to find microbes somewhere in the solar system, but that’s complicated, because of the mixing up of material.
But the approach that’s dear to my heart is to look for a second sample of life right here on Earth. Because if life does pop up readily in Earth-like conditions, it should have started many times on Earth, not just once. And so far, all the life that we have studied has been the same life: It’s on the same tree, with the same genetic code, and all the other details; it clearly has a common origin. But of course we’ve only studied a tiny fraction of the microbial life on Earth, and we have no idea what all those other little bugs out there might be, and it’s not inconceivable that we will find that there’s an alternative form of life right under our noses.
We may not have to go anywhere to answer the question: ‘How likely is it that life will emerge in Earth-like conditions.’ If we find just one other microbe that is sufficiently different, biochemically, from known life as to qualify for an independent origin, then we can be pretty confident that wherever we find Earth-like planets we’re going to find life. But that’s obviously a long shot, and so I’m completely open-minded as to whether life is a bizarre fluke, unique to Earth—we might be the only planet in the universe that has life on it—or whether the universe is teeming with life.
When I was a student in the 1960s in London, I was interested in searching for life beyond earth. Well, one might just as well have professed an interest in searching for faeries. It was considered completely bizarre, and absurd, because everybody knew that life was so complex that it could only happen once, and that was the official view among biologists, and anybody who suggested that there could be life on other planets was regarded as a complete crackpot.
Now the pendulum has swung the other way, and everyone pays lip service to all these planets out there and the chances of there being life on them. But the science hasn’t changed; we know no more now about how life began than we did then, and so there’s not a shred of evidence that life is likely to occur whenever there are Earth-like conditions—no evidence whatsoever. It’s just a matter of opinion.
So I remain, in the good scientific tradition, completely open-minded as to whether it’s on the one extreme a bizarre fluke, or on the other extreme a natural part of the outworkings of nature.
WSF: If life were detected ‘out there,’ would you be more inclined to believe it ultimately derived from the same source as ours, or from a second, unrelated outgrowth of life?
PD: I have a soft spot for panspermia because it was championed by Fred Hoyle, who gave me my first job, in Cambridge in 1970, and who was one of these extraordinarily creative individuals who would have ten crazy ideas a day, one of which may actually have been not so crazy. He was strongly of the belief that life was hard to make, but that once it got going it would spread around the universe, sort of wafting naked in the interstellar spaces. I have never felt that that idea works very well, for the simple reason that outer space is a very harsh radiation environment, and unless a microbe is cocooned inside a rock, then it’s not going to survive for very long.
But once you start putting microbes in rocks, we can get rocks off planets easily enough with impacts: comets and asteroids. And the rocks can be flung out of planetary systems by well-understood Newtonian principles. So rocks do travel across interstellar space, but then the probability of a rock for example that’s knocked off Earth ever hitting another Earth-like planet in our galaxy is exceedingly low. So now the numbers are against you.
Where the numbers DO work out well is near-neighbor planetary swapping, like Earth and Mars. The numbers suggest that Earth rocks might even make it out to Europa. So if we’re talking about the solar system—if we find life in the solar system that’s biochemically similar to ours—for my money I would suggest it got there by this rocky panspermia mechanism. But if we could by some magic discern what the biochemistry of life in an extrasolar planet might be, then I think it’s far less likely. Just because of the way the numbers work out.
The thing is, what we really don’t know is: Are there forms of life that might be much more resilient to space conditions than those with which we’re familiar. Because we shouldn’t assume that the first life, for example on Earth, really was all that much like the life we see now; it could have had very different properties. And so, because life adapts to the conditions it’s in—the Earth’s been in its present state for over three billion years—it’s very hard to go back and figure out what the first form of life might be like. Hence the problem about going from non-life to life; it’s hard to get too many clues, from extant life, as to the properties of the very first form of life.
WSF: Professor Stephen Hawking and others have cautioned of the potential dangers of communicating with alien life; that the risks might outweigh the rewards. What’s your position?
PD: I can be very clear about that, because I think there’s a lot of muddled thinking that goes behind these scare stories. Why would an alien civilization want to come to our planet? There are only two reasons: One is that they might want the planet, and one is that they might want us. Now, I can’t believe that a civilization that might even be post-biological would have the slightest interest in human beings. You might say ‘Oh, well they would want to enslave us, so we could make gadgets for them.’ Well, surely if they’re capable of interstellar travel they’re capable of making robots to do that. So I think it’s inconceivable that humanity would be of more than academic interest to an alien civilization.
However, they might want our planet, absolutely. Well, it’s been around for four and a half billion years, and they didn’t come and take it! They don’t need us to invite them in; it’s there for the taking. And people seem to forget just how old our planet is. They also seem to forget that even at four and a half billion years of age, it’s still only about a third as old as the universe; there could have been civilizations out there in the galaxy, if you’re an optimist, that existed even before the solar system formed. And so, anyone simply interested in colonizing the galaxy, or conquest or anything of that sort, they’ve been free to do it. Why should it be, in the tiny sliver of time that human beings have been on this planet, that suddenly they become interested and come here?
They certainly don’t need us to send them a radio signal—if they can pick up a radio signal they can already see that there’s life on Earth, or that there’s conditions for life. So if they want the planet for its raw materials or just to colonize, they’ve already got that information. And a signal from us, if anything, would deter them. I can imagine they’d say “well, let’s pick a planet that doesn’t have any life on it, it would be easier, or where we’re not going to get in trouble with the locals.” I’ve never understood why people attach any sort of risk to the idea that we somehow announce our presence. We’re doing it anyway! Every time we broadcast or send out radio, radar, anything of that sort…it’s pretty obvious!
But if humanity’s planning space-based instrumentation, which in principle would have the ability to image the surfaces of other planets at a very high resolution, and if we’re talking about a civilization that might be not just thousands of years ahead of us—not just millions, but tens or hundreds of millions—they would have technology we couldn’t even dream of. They will know all about the surface of our planet.
WSF: What if we were in the position of discovering a civilization less developed than us? What would the Earth response be if we encountered the equivalent of Paleolithic Earth or something like that?
PD: I think this is an entirely believable scenario. Very sensible question! Because we sort of take it for granted that when intelligent life appears on a planet, then it’s developed technology, discovers science, progresses, achieves great things, because that’s been our experience.
But when you stand back and look at human history, you realize this thing we call science—which most people take for granted: ‘of course science works, of course this is the way you go about studying the world’—well, it is not obvious at all that another civilization, even if they got to the stage of having some technology, would understand the deep mathematical principles that lie behind science.
For example, the Chinese famously discovered the compass, but they didn’t understand the principles of electromagnetism. And so if you say to them, ‘Well, you’ve discovered the compass, now design the Large Hadron Collider,’ that would be completely hopeless. The reason we have build the Large Hadron Collider is we understand the principles: not just of electromagnetism, but of a lot of other things. And that discovery of the deep mathematical basis of nature is something that is culturally very specific; you wouldn’t do it by trial and error in a million years. You have the cultural antecedents that go into developing this thing we call science.
You might discover, over a long period of time, a lot of useful gadgets by trial and error. But there’s absolutely no reason why you would have our level of understanding of how the universe works – that could be entirely a quirk of our particular culture. And so I think it’s entirely possible that if we were to achieve interstellar travel, that we would come across a planet with very intelligent beings who would have, by our standards, a very low level of technology. And I think we’d have a huge ethical responsibility to not damage their society.
WSF: The ‘prime directive’ from science fiction: to do no harm.
PD: Yes! I might just say as a postscript that a lot of people think: ‘well wouldn’t it be great to be in touch with E.T., because we could learn all sorts of cool stuff about science and technology, and we could improve our condition.’ But actually, the sudden influx of any sort of knowledge or technology could be very destabilizing. And example that I gave in my book Eerie Silence is: We’ve been struggling to get nuclear fusion under control for some decades. And if we did, this would solve, with one stroke, the world’s energy crisis. Suppose we picked up a message from E.T. and they handily told us how to get controlled nuclear fusion to work. You’d think, ‘Wouldn’t that be a blessing?’ and the answer is no! Because the country that picked up that information would immediately be able to hold all the other countries hostage, the world’s energy markets would be completely destabilized; there would probably be a world war soon afterwards. It’s a poisoned chalice, to be handed something that suddenly transforms our technology, even in a manner that we’re trying to do ourselves. So I think this encounter between civilizations at very different levels of development would be very, very risky. It needs a lot of careful thought about ‘should this happen’?
WSF: So it’s almost like a teacher-student relationship—you have to bring them along at the appropriate level of understanding.
PD: I think you need to have a deep understanding of how the society works as well as what the technology is.
WSF: If you were Earth’s point person at the moment of contact with an alien civilization, how would you explain our cultural complexities? How do you wrap up Earth in a conversation?
PD: There are two schools of thought on this one, and they represent opposite extremes. Seth Shostak of the SETI Institute thinks we should just sort of dump all the contents of the Internet out there and let them figure it out. I take the opposite point of view: If we’re trying to communicate, then of course there’s a trade-off between the amount you can communicate and how much will be understood.
There’s no point in giving people data without having some understanding. What would alien minds and we have in common? What is it we could possibly communicate about our society that would make any sense to them? If we speak in English or Chinese or whatever it may be, they’re not going to understand that. And even if we could get around the language problem, our sports and politics and religion would probably mean absolutely nothing to them.
But there are things that do have meaning. Carl Sagan was all for using mathematics as the common language, and it’s true that mathematics is something that’s independent of culture. One plus one equals two, whoever you’re talking to. And mathematics is also the language of fundamental physics. There are aspects of, for example, the quantum theory of fields that we’ve got under control. They’re pure numbers, they don’t have units attached, so you don’t have to worry about telling them how long a foot is, or something like that.
At a stroke, they would recognize these numbers convey our level of understanding of things like quantum mechanics and the theory of relativity. That tells them a whole lot, actually, in just one number. My view is we should start out with that and take it from there. It will be a long time, I think, before we can explain to them the subtleties of a U.S. presidential election.
WSF: Here’s a question posed by one of our readers: If we were visited by an alliance that exists in space, and they judged that we were of a sufficient level to join them or not, how do you think Earth would come to that decision in a democratic way?
PD: This is an interesting question, and it’s been around since the beginning of the SETI program over 50 years ago. It’s sometimes called the “Galactic Club.” The point being that if we pick up some sort of signal or message from an alien civilization, this is not really going to be the first time this has ever happened in the galaxy; we are the new kids on the block, the latecomers, because we’ve only just developed radio communication technology. The numbers game shows that if this is possible, then it’s going to have happened many, many times already in the history of the galaxy. And there would probably be a communication network already existing, a Galactic Internet already out there.
The only sad thing, of course, is that the communication’s going to be exceedingly slow. It takes light 100,000 years to cross the galaxy. So we’re not really dealing with real-time communication.
With a possible exception: If there’s an alien probe in our solar system that’s been sitting for millions or tens of millions of years, waiting to be woken up by some radio traffic coming from Earth, then we could have an almost real-time conversation with this probe. But that wouldn’t be a Galactic Club, that would just be a local emissary from some distant civilization.
Supposing there is this club, with this very ponderous exchange of ideas and information, then obviously the next step would be, what are we going to do about it? I foresee lots of problems.
It’s very easy for me, a gung-ho scientist, to think, ‘Well obviously we would join this club! Humanity has promoted itself into the realm of the cosmic; isn’t this our destiny? And I know lots of other people who would feel very much the same way. I also know people who are not only scared of the idea of extraterrestrial civilizations, but on some sort of vague religious grounds might feel that human beings are special, and that this is not a path down which they would embark.
So I could see, if we tried to have a worldwide debate about what to do next, we would find extraordinary views coming from some quarters about how this was wrong or we would be dealing with the devil or something of that sort. We’d find people who’d say this is the true messianic message we’ve been waiting for. I don’t think the rest of the world would see it in the same way as I do.
WSF: It could really split our civilization.
PD: Yes I think it could.
WSF: Getting back to SETI specifically, and the plan the Task Force has in place, are there any specifics you can share?
PD: There are protocols in place, and these protocols exist independently of the SETI task group. With SETI and all the people who deliberate about this, it takes place in a completely open way. There’s no conspiracy, there are no secrets, no intent to hide things from the public. It’s all taking place in the open by ordinary scientists using ordinary scientific procedures and communications.
The second thing is, you may dream up some wonderful logical protocol, but we all know when somebody thinks they’ve found something, all of that goes out the window. It’s worth looking back at a few cases where there have been false alarms—when SETI scientists have picked up on really intriguing signals and obviously until they’ve checked it out, they’re disinclined to make any sort of public statement.
The question is: How long do you get to check it out? In the early days of SETI, the plan was that if somebody with a radio telescope picks up what looks like a message, the first thing you’d do (after tipping the radio telescope away from your eye and back, again and again) is you’d call someone on the other side of the world and ask ‘are you picking this up too?’ And they’re asleep, and they’ve got to get up and get dressed and go into work and get their equipment going, and it’s going to take hours. In practice, to do all these sorts of checks where you might then say, ‘right we need to go to the next level of checks,’ would take like 24 hours.
But in these days of social media, you don’t get more than 24 minutes. All it needs is somebody in the coffee room or passing down the corridor saying ‘oh, they look excited!’ and send out a Tweet to the girlfriend or boyfriend, and then it’s gone viral before you know it. So one of the things the Task Group has concerned itself with is: Is there a possibility that the lines of communication that the astronomers are using would crash as a result of all the traffic? Would people even be able to go to work if they’re surrounded by TV film crews? That’s a real danger.
Take stuff like the impact of asteroids or comets; you read in newspapers ‘there’s a chance this one might hit us!’ Then, of course, as the observations proceed and the calculations are refined, what looked like it could hit us turned out to be a miss. And you go through hundreds or thousands of these near-misses before you there really is one that’s going to hit us. And that’s true of SETI: There’ll be thousands of false alarms before you’ve got the real thing. And if every time the whole system collapses in the frenzy that surrounds it, that’s not a very good way of doing science.
I don’t think we have an easy solution, except to recognize that that problem is there. At the end of the day, the scenario we’ve been talking about, a radioastronomer looking for a message that has been beamed at us and telling colleagues, I think that is a very unlikely way that we would make this discovery. It’s more likely to come from someone who has no interest in SETI, sees something they don’t understand that over a period of time won’t go away, and other people will dismiss it, until it forces itself on the community.
WSF: Maybe our newfound ability to assess Big Data might lead us to the first real clues.
PD: I believe what you’re saying is correct. We have no idea how an alien civilization would manifest itself if it’s been around for a very long period of time; it could be in any of the databases that we have. There are vast amounts of genomic data, astronomical data, climatic data, particle physics data; everywhere you look there’s petabytes of data piling up and piling up. Anywhere in that could be some sort of clue, some hint that this is something which has no natural origin and is not a product of human technology.
You have to take a long-term view. If we take this position that we’re not alone, that the universe is teeming with intelligent life, you have to recognize that it would have been around for a very long period of time.
If there were alien technology in the solar system, when did it arrive? A hundred million years ago? What would last a hundred million years? Not much, but there are some things, like nuclear waste. Or any sort of biotechnology that has knock-on effects: If you tinkered with genomes a hundred million years ago, the traces of that would still be with us today. Or any large-scale quarrying: If you chopped up an asteroid in a very distinctive way, that’d still be orbiting. Who knows when we might stumble across such a thing? We’d say, the aliens came, and they’re gone, but they left a calling card inadvertently. That’s going to be one of the biggest discoveries in the history of mankind. We can’t say who they are, where they’re from, or much about when they came, but we can say that we’re no longer alone in the universe. We’ve answered one of those big questions of existence.
WSF: Final question: If you got only one question to ask a member of an advanced otherworldly civilization, what would you ask?
PD: Naturally, as a theoretical physicist, I’d want to ask something that’s at the forefront of one of the great unsolved puzzles of physics. It relates to something we were just talking about: sending them a number. But if you could send them a number, what would it be? One of these is 1/137—that’s approximate—that’s the fine structure constant, the ratio of the square of the charge on the electron divided by Planck’s constant and the speed of light. It’s a pure number, and this number is deeply intriguing. No one knows why we live in a universe where that number is what it is; nobody’s been able to derive it, and I’ve tried. I would love to know why that number is what it is. I’m sure there’s a reason, but we can’t derive it from any known physics, so I think that would be my favorite question.
Want to learn even more about Paul Davies and the search for alien life? Watch him and other panelist discuss on Alien Life: Will We Know It When We See It?