INTERVIEW OF THE WEEK
For this week’s session, Day Star’s president, Fred Heeren, interviewed the following five astronomers to discuss the likelihood of the existence of extraterrestrial life and intelligence:
ROBERT JASTROW, founder of NASA’s Goddard Institute, now director of the
Mount Wilson Institute and its observatory.
GEORGE SMOOT, leader of the NASA COBE satellite team that first detected cosmic
“seeds” for our universe, Lawrence Berkeley Laboratory.
CHARLES STEIDEL, leader of the international team of astronomers that recently
developed a technique to identify distant, primeval galaxies by the score, California
Institute of Technology.
ERIC CARLSON, senior astronomer emeritus, Adler Planetarium in Chicago.
SALLIE BALIUNAS, astronomer, Harvard-Smithsonian Center for Astrophysics.
Are there extraterrestrial civilizations out there?
Our recent interviews have covered the topic of how physicists and cosmologists explain the fine tuning of the universe. Most astronomers think that if all this fine tuning makes us possible, why not others? Here are the relevant portions of Fred Heeren’s recent interviews regarding this question.
HEEREN: Now that we seem to be discovering new planets orbiting other stars almost on a weekly basis, what do you think about the possibility of there being extraterrestrial civilizations out there somewhere?
JASTROW: I find it hard to imagine that there are not,
knowing that there are ten billion galaxies similar to ours, each with a hundred billion
sun-like stars, in the visible universe. It seems inconceivable to me that ours is the
only inhabited one. And when I know, as I do, that those other beings on other planets, if
they're there, are some of them billions of years beyond us in age and advancement, I
think that mankind's place in the cosmos is very humble indeed, and when we make contact
with them, it will be a transforming event. I do not know how the Judeo-Christian
tradition will react to this development, because it will be hard to fit in. The concept
that beings superior to us, not only technically, but perhaps spiritually and morally,
exist in this universe, will take some rethinking, I think, of the classic doctrines of
western religion.
HEEREN: How do you feel about the likelihood that we'll hear from extraterrestrials anytime soon?
JASTROW: I believe that's a very sound, scientifically sound statement, because the TV and FM broadcasts, let alone the radar from our defense installations, are sending out a signal, a shell of radio energy that signals that there is life on this planet, and that started in intensity, oh, about 30 years ago, I would say, in the 1960s. And all those I Love Lucy and Jack Parr shows are spreading out into the cosmos, and it's been going on for thirty years at the million watt level. So it's spread out thirty light years. And within thirty light years there are some dozens of stars. And if they got the word thirty years ago, they would be sending a reply back to us. And those who are only fifteen light-years away, will have sent a message back fifteen years ago, which should just about be reaching us today... I think that mankind is on the threshold of entering a large cosmic community.
HEEREN: Dr. Baliunas, what do you believe about the possibility of there being extraterrestrial civilizations out there?
BALIUNAS: Scientifically, I think there is little doubt that the universe is populated with intelligences, most of them probably far in advance of our own, because we've only been around a very short time, in the cosmos, some four-and-a-half billion years, compared to the fifteen billion years or so the universe has been around.
HEEREN: How do you feel about the likelihood that we'll hear from them?
BALIUNAS: That's a different question. If they're very far advanced from us, they might have looked in on us and found us very uninteresting. Much as we would not bother to communicate or think about what ants think and feel.
HEEREN: Dr. Steidel, how do you feel about the possibility of there being extraterrestrial civilizations out there somewhere?
STEIDEL: Well, civilizations is one thing, and life is another thing.
I think it's virtually certain that somewhere in the universe, life exists.... I mean,
when we add up how many galaxies are out there and how many stars are in each galaxies,
and even if a small fraction of those stars could harbor planetary systems, the chances of
life existing somewhere else are extremely high. Just by sheer statistics, that's the
case—
HEEREN: Assuming that the right conditions for life would always produce it.
STEIDEL: That's, that's right. I mean, but we already know that there are lots of stars like the sun in galaxies out there. There's no reason to believe, objectively, that our solar system is all that unusual—I mean the sun is a fairly average star. So I would say that the chances of life being out there are very high. The chances of life with which we want to communicate, or would be capable of communicating, I think that's fairly low, actually, because I think there are so many ways that things could develop.
HEEREN: Dr. Smoot, how do you feel about the possibility of there being extraterrestrial civilizations out there somewhere?
SMOOT: I think it's extremely likely, and I can give you
sort of a simple, thumbnail sketch why. If we look out of our galaxy with good telescopes,
like the Hubble telescope, or ground-based telescope, we can estimate how many stars are
in our galaxy, and it's about a hundred billion. But it you use these good telescopes and
take a deep image, in the background, between any star that you take a picture of, you
always see one or more galaxies, that also have a hundred billion stars in them.
So you have a hundred billion times a hundred billion stars that are potential solar systems, and as you might know, some of my colleagues here have recently discovered planets around neighboring stars, so you know there are a very large number of solar systems out there... But the chances of there being life near to us, I think that's pretty low, and whether there's life in our own galaxy, I don't know, besides ourselves. But I do think that in the universe, it's very likely that there's life in other places.
And the universe may be very much bigger than that hundred billion galaxies—that's just as far as we can see with our telescopes. The universe itself may be much, much bigger than that. And so it seems to me a sort of form of hubris to think that God made the universe just for us, right? He made all these hundreds of billions of galaxies, just to have one little isolated solar system have life on it. It seems to me, I'd just make the universe full of life.
HEEREN: Dr. Carlson, I know you’ve been following all these exoplanet discoveries closely. What do these discoveries say about the likelihood of extraterrestrial civilizations elsewhere in our galaxy?
CARLSON: Well, it certainly lends
support to the idea. I think most of us have been believing for a long time that planet
formation is very, very likely to be frequent, and common, as a natural accompaniment of
star formation. And so, you look around the galaxy, then you have to go through all these
weedings out, you say well this star's too big, because it would burn out and blow up too
soon, and that one is too small, because to be warm enough, you'd have to be so close to
the star that tides would keep you from spinning, and there's all kinds of reasons why
different certain kinds of stars would not be a hospitable place for life as we know it,
which is pretty much what we limit the discussion to, but still, you wind up with such
huge numbers.
How many just plain sunlike stars could there be? Well, there's probably about a billion at least, and then if you count stars that are sort of similar to the sun, there could be quite a bit more, and that's just in our galaxy, and of course they haven't been all born at the same time. That's the other thing you have to keep in mind. This might be a fairly frequent occurrence, but what does it mean when you say, well, out of your billion stars, these started up an earth-like planet, and maybe just dated five billion years, like it happened here. Maybe,—We started 10 billion years into cosmic history, as we call it, and, so some other system started seven billion years into cosmic history. Well then where are they now? If we started at 10, if we're 3 billion years behind them, or they're three billion ahead —
FRED: So the likelihood should be that there should many who are far advanced... beyond us by now.
CARLSON: Yes, but what happens to them in a course of time like that? Can you imagine what this place is going to be like—human culture, life, even—on earth, in 10,000 years, or 100,000 years, or one million, much less a thousand millions, which would be one billion years, and then multiples of that. I mean, I can't imagine it. So I tend to get this sense of a galaxy—sort of like a garden—you have the early spring flowers, and then you have the late spring flowers and the summer flowers and so on, and you have things, consciousness, perhaps, or life with consciousness, springing up here for a while or there for a while. And whether it's ever in contact at the same time, I just don't know.... On the other hand, I used to rather enjoy thinking that, well, the early civilizations would have set up an inter-communicating [system], maybe laser beams or something full of information about all the other civilizations in the past history of the galaxy, and that this is all circulating around from star to star around the galaxy, and all we have to do is tap into it, and find out all this.
Opinions vary among astronomers, from those who believe, like Robert Jastrow, that we’re on the verge of entering a larger cosmic community, to those like Eric Carlson, who believe that civilizations may be rare and separated by vast amounts of time as well as distance. I have seen many become more conservative in their beliefs since SETI’s earlier days, when they believed that extraterrestrial radio signals should be out there for the picking. After 37 years of concerted searching with the world’s most powerful radio telescopes, why are they coming up empty?
My book, Show Me God, explores the evidence for and against extraterrestrial life and intelligence, from the latest SETI projects to the recent Martian findings, from the exobiologists to the exoplanet finders who have recently revolutionized our understanding of what makes a “typical” solar system. I show how scientists have come up with formulas, such as the Drake equation, to estimate the likelihood of nearby civilizations, and what happens when we plug into those equations the most recent data.
Like most of us, astronomers and cosmologists seem to want to believe that extraterrestrial civilizations exist, be they rare or not. For the scientist, this belief is essential to the scientific study of life’s origin on this planet, since experimental control and statistical validity require that we study a large sampling. We can’t have a collection of one, after all. One-time, unrepeatable events are outside the domain of science.
But the cutting edge of cosmology today centers around an even bigger question than whether there’s extraterrestrial life. The really big question is: How did the universe get so precisely tuned for life in the first place? The universe’s fine-tuning for life, a cosmological problem since the 1960s and 70s, may be the best reason to believe in extraterrestrial life today.
You'll find the whole history of these twentieth century cosmological discoveries, and the bigger implications for everyday life, in Day Star's new book, Show Me God.
DAY STAR’S DISCUSSION-KICKER OF THE WEEK
Astronomers and physicists have learned that dozens of cosmological
parameters—including the rate of cosmic expansion, the ratio of nature’s four
fundamental forces, the ratio between the masses of the proton and the electron, the
resonance of the carbon atom—all seem to be finely tuned for life against impossible
odds. Many cosmologists say that the most obvious explanation is that the universe was
somehow “meant” to host conscious life.
Yet top biologists routinely tell us that conscious life—that is, intelligent life—is a freak, since evolution works without a game plan. Human intelligence—and the ability of our species to write great literature, compose symphonies, create fine art, etc.—appears as an extreme case of overkill. We don’t need these things to survive. The renowned paleontologist Stephen Jay Gould calls human intelligence “an ultimate in oddball rarity.” His Harvard colleague, zoologist Ernst Mayr, calls the search for extraterrestrial life “hopeless” and “a waste of time.”
Is there a way to reconcile the biologists, who don’t expect us to find an abundance of intelligent life out there, with the cosmologists, who say the universe appears to have been set up for conscious life? Could the entire universe have been set up so that just this one solar system might host intelligent life? Or is that thought so absurd that we should rather expect to find intelligent life everywhere?
And, to get back to the truly big question, why do cosmologists get this impression of “intent” or “purpose” in the way the universe is set up against infinite odds to suit the narrow requirements for life? Why do you think the universe is so perfectly suited for life in the first place?