It's great to welcome to the program today, Adam Frank, who's a professor of astrophysics
at the university, the city
of Rochester. Also author of the book light of the stars, Alien Worlds and the fate of
the earth. Adam, so great to have you on today.
Real pleasure.
So just to begin with, if we want to broadly start thinking about the idea of life in the
universe, outside of earth, there are those who make sort of mathematical probabilistic
arguments. If you consider the size of the universe, it's mathematically likely that
there is life elsewhere. There are others who make arguments sort of along different
lines. What is the best filter or frame through which you think is most useful to think about
that question of life elsewhere in the universe?
Yeah, that's a great question. And you're, the probabilistic arguments still, uh, are
the best, especially given the a what I like to call the exoplanet revolution of the last
20 years or so. So, you know, when people started thinking about this via the Drake
equation, you know, that's really where the probabilistic arguments came from. Uh, in
1960, you know, we really didn't know much about, uh, what was out there in terms of
just the baseline for where life could form. And now we know that every star in the sky
pretty much has planets. So we did a paper a few years ago that used the empirical data
to set kind of a baseline on, um, how this one way of framing it is how unlikely would
it have to be for us to be the only, uh, um, civilization in the universe. And it turns
out to be one in 10 billion trillion, like the odds per habitable planet would have to
be less than one in 10 billion trillion in order for us to be, the only time it's happened.
That number is so low that you're really beginning to stretch the bounds of credibility. So,
um, you know, we know now that there are so many planets, so many places for life to form
that I think that way of understanding it is the right way of sort of getting a handle
on at least whether or not civilizations have happened before. It doesn't mean there's anybody
around now, but whether or not you know where a a one off.
So w how different are the questions of, is there life elsewhere in the universe versus
is there currently what we would call intelligent life elsewhere in the universe? Cause those
might sound like similar questions, but mathematically they might be drastically different.
Yeah, that's a great point. In fact, they could be enormously different. If you look
at the history of the earth, for example, um, microbial life seems to have appeared
very rapidly after the earth formed, you know, 4 billion years ago or so. And it took intelligence
intelligence, you know, literally only happened yesterday. So if you just look at that, it
seems like you can use that argument to say, look, microbial life, you know, basic life
is going to be very easy to form, but getting intelligence may require a lot more, um, uh,
accidents. So to speak, to happen, you've got to pile them on, you know, so, so I think
it's, it's, it's reasonable to separate those out. But when it comes to finding life, it
may be that it's more easy. It may be easier to find us, um, uh, signatures of technological
civilizations than it is, uh, finding, you know, evidence on just in planets of just
microbial life.
When we think about the idea of intelligent life now versus at some point in the past,
which you alluded to, let's dig into that a little bit. There's this concept of some
kind of possible filter which might explain why there, uh, we have not heard from other
intelligent forms of life and that may be that once life gets to a certain level of
intelligence, something happens that destroys it. It could be self-destruction, it could
be something else. Can you talk a little bit about that concept and how it should sort
of inform our analysis of this?
Sure, sure. That's what's called the great filter. But if you don't mind if we just step
back a little bit, because the reason this question, people have like, oh, we've been
looking for so long and we haven't seen anything that is sometimes called the great silence
and it turns out that's not true. I mean when people have to understand about the search
for extraterrestrial intelligence is that really NASA or anybody else has never funded
a very detailed search. So recently, uh, there was a paper that was done where, uh, basically,
um, a couple of astronomers looked at how much of the sky we've looked at. And so if
the sky was like the ocean, we have only searched right now through a hot tub. So, you know,
if you looked at a hot tub and didn't find any dolphins, you wouldn't say, oh, the ocean
doesn't have any telephones in it.
So that's something that's very important to know is that we haven't looked very hard,
look very hard. So we don't know. Uh, but the, the great filter argument is the possibility
that, uh, or posits that, yeah, there's something that either keeps intelligent civilizations
from forming or they don't last long, right? Because if every civilization, civilizations
can be popping up all the time, but if they all last 200 years, which may be how long
we last, um, then you know, there's not going to be many out there to talk to. So the grade
filter could be in our past. It could be that, uh, it's very hard to form intelligence for
example. And somehow we got through hooray or the into the great filter could be climate
change. It could be that everybody triggers climate change and very few civilizations
are smart enough to get through it. So most of them end with their climate change period.
So the great filter could be hiding like a snake in the our future or it's in the path
that we got lucky.
That's interesting. So then let's talk about climate change a little bit. The idea would
be that dealing with climate change, that intelligent life inevitably starts to modify
their environment in such a way that it will ultimately potentially at least cause the
self destruction of, of that environment, of that civilization. This is merely speculative
at this point. Or how much, how much has that concept caught on in the context of great
filter discussions?
Well, it's, you know, this is the work that I and my colleagues have been doing and you
know, we've been arguing that it's really hard not to trigger climate change. If you
are, what is a civilization? What do we, what do we mean from a scientific point about what
a civilization is? It's basically a species that has become very successful at harvesting
energy from their planet. Now, we now know enough about planets from studying earth's
history from Mars, Venus, the moon tightened around Saturn that we understand climate really
well. And if you're going to harvest a huge amount of energy to do work, which is what
civilization is, um, you're going to have a feedback on your planet. It's going to be
hard not to have a feedback on a planet. So I got, first of all, this totally changes
how we look at climate change right there.
The question now is no longer did we change the climate. Instead, it's like, Duh, what
did you expect to happen? You built a giant civilization. So then the next question is,
does this always happen? And I think the argument we've been running models we've been starting
to do, um, starting off with simple five models of planets and civilizations, very generic.
And what we find is that you always trigger climate change. It's hard not to feedback
on your planet. And then the question is who gets through, right? What does it take to
get you through this period and come to a new equilibrium with your planet? And that's
very much an open question. Uh, we did find luckily that some of the models led to a new
steady state, uh, change climate, but, but the whole idea your civilization does and
die off, but also many of the models showed collapse as well. So, you know, there's a
lot more work to be done on this, but I think the answer is that pretty much every technological
civilization triggers climate change and some will get through and many won't.
So there's the movement that is the search for extraterrestrial life and or intelligence.
There's a movement, uh, that is a sort of space exploration movement for the preservation
of Homo sapiens. The idea that eventually it could be because of climate change in 50
years, it could be because the sun expands and engulfs the earth in much longer than
that. But like eventually there will need to be some other place for homosapiens if
the species is to persist. Um, there is the idea of exploring space for the benefit of
technological development to be used here on earth. There's all these different areas.
Question One, do these, uh, interact with each other in substantively meaningful ways
or are they relatively siloed and endeavors and priorities? And number two, what's your
more general sense of what the relationship should be of humans to space exploration right
now and sort of over the next 10 to 20 years?
Those are great questions. Well, for your first one about the siloing, they were siloed,
but what's remarkable is that with climate change, they can't be siloed anymore. Right?
Climate Change. We think of climate change in terms of this, you know, we're running
around like a chicken with our heads cut off. Half the country doesn't even think it's happening.
The other half is, you know, is, is terrified. And I think what we have to understand is
that climate change is actually a profound transformation. It's a, it's a moment. It's
like adolescence, right? When you become an adolescent, you've now gained enough power
over yourself. But you can have the keys to your, a to a car. We now have the keys to
a planet. We never would have learned about this unless we were doing space exploration.
Right? It's, we only really figured out climate change because we were looking at the earth
from orbit or we were looking at other planets.
Understanding Mars and Venus were instrumental to our understanding climate change. So you
know, space exploration are, are becoming a space fairing race are becoming triggering
climate change and are recognizing climate change all fit together. And I think that's
going to be true of any civilization. So we now have to recognize that all of these things
are happening at the same time because they're supposed to happen at the same time you trigger
climate change. You know when you become a space bearing race. Cause that's when you
have the industrial capability and you don't get to know that you triggered climate change
unless you're a space bearing race. And then hopefully you'll learn what to do with it.
Um, so at one thing also I want to point out though there is no planet B, like there's
no way that we're using, we're going to get to Mars, we're going to be able to offload
to Mars to deal with climate change.
We have to deal with climate change here on earth. Um, but here's it for your second question.
I think the W uh, what is important is that space. We are just about to become truly a
space fairing race. Like the last 50 years we've taken our first tentative steps and
now with the new space movement, as you're pointing out with Elon Musk and commercial,
uh, the commercial utilization of space, we are poised to begin settling the solar system.
And I'm, I'm a big fan of this for many reasons, but mainly it's because in some sense the
next thousand years or so of human history, if we make it through climate change, is going
to be the settlement of the solar system because the stars are too far away. Barring a technological
miracle, the solar system is really where the next a thousand years of our history gets
played out. So if we can get through climate change and we can, you know, manage to understand
how to have a, a, an eco, a thriving ecosystem on earth, we're going to learn enough to start
building artificial ecosystems, large artificial ecosystems elsewhere in the solar system.
So it's all very tightly coupled together for me.
Uh, when we think about, um, policy, uh, between countries, between nation states, with regard
to space, it's sort of a wild west right now. I mean, you've got the, I believe it's the
moon treaty from the 70s. Uh, and there's some one piece of legislation that I think
is more recent, but how soon do you think that the lack of, of legal infrastructure
in space will become relevant based on what it is that's planned over the next 10, 20,
30 years?
Yeah, we're already in trouble. I mean, we're already at the end of those treaties. We have,
we're very quickly, we're going to need to start rethinking a best because you know,
if you want to have a thriving space economy, I am all for the, you know, economic, using
space, not just exploration but beginning to start thinking about it in terms of commercial
activity cause nobody's going there unless there's money to be made. Right? Um, and that's
how you will start building thriving new, interesting communities, people trying all
different kinds of experiments and democracy and other good things, um, or you know, in
these settlements. So you have to be able to ensure both, um, the commercial viability
people have to be able to invest and have a return on their investments. But also at
the same time, you've also got to make sure that all of spaces open for everybody. You
don't want to have like two corporations battling it out, uh, for a, you know, for the ownership
of space. So there is, there's a lot of very tricky legal precedents that we're going to
have to establish, um, over the next few years. And right now, as you said, it's a wild west.
So people need to really understand that space is not just for, you know, heroic astronauts
anymore. Very soon it's going to be for working people and, and be investors and, and explorers.
So yeah, we're right on the lipid that
I don't doubt that. At the same time though, what scares me is I have this idea and maybe
it's an incredibly naive and idealistic thing, that a progress in space would be an extremely
sort of uniting process for humans on earth. That the imaginary borders between countries
would become far less relevant as we start to become a space bearing race. And I mean
imagine for a second, if we were to encounter in intelligent life elsewhere, my ma, where
I get scared is I feel as though it being hyper commercialized from the beginning. We'll
basically just transfer all the same problems we're already dealing with here to space and
it will sort of counteract that possible uniting force. Is that a concern that you had that
you share or my maybe missing something?
No, no, I think that's a good concern. That's why these treaties have to balance you. We
have to learn from our mistakes, uh, in our various periods of colonization over the last
10,000 years. You know, we have to learn from our mistakes in the past about how to, you
know, explore because that's what we do. You know, human beings are always going over the
net or the next hill looking for a better deal. Um, so how to both have that need to
expand but also do it sensibly and do it with some kind of a compassion, both for the environments
that we're touching, even if they're not living, um, as well as ourselves. And so, you know,
my hope is that, uh, you know, that is, is going to be possible. So, you know, but that's
going to be very tricky. But again, that's why this is so tied to climate change. Like,
you know, in many ways we're going to have to reorganize ourselves on a pretty deep level
in order to get through climate change as well. So all of this stuff is happening at
the same time and all of it poses the possibility. Either you can go down the same, you know,
and make the same mistakes or you have these possibilities of really reconfiguring the
way you do civilization in ways that will be more free, more compassionate, um, and,
and allow life of all kinds to thrive.
Make sure you check out the book light of the stars, Alien Worlds and the fate of the
earth. We've been speaking of course with the books
there. Adam Frank, who's a professor of astrophysics at the University of Rochester. Uh, Adam,
really a pleasure having you today. It was really fun talking. Thank you.