This is the Drake Equation, first presented
in 1960, by Dr. Frank Drake, an astronomer
at the National Radio Astronomy Observatory
in Green Bank, West Virginia, wherein N equals
the number of civilizations in the Milky Way
Galaxy whose electromagnetic emissions are
detectable.
R equals the rate of formation of stars suitable
for the development of intelligent life.
f-p equals the fraction of those stars with
planetary systems.
n-e equals the number of planets per solar
system with an environment suitable for life.
f-l equals the fraction of suitable planets
on which life actually appears.
f-i equals the fraction of life bearing planets
on which intelligent life emerges.
f-c equals the fraction of civilizations that
develop a technology that releases detectable
signs of their existence into space.
L equals the length of time such civilizations
release detectable signals into space.
Got all that?
Since 1961, scientists have used the Drake
Equation to stimulate thinking about finding
life elsewhere in the universe.
In the words of one of our greatest cosmological
minds:
Are we alone?
How?
How common is this thing called life?
This thing called intelligence.
Where did we come from?
What are the possible fates of intelligent
beings?
Need we necessarily destroy ourselves?
Might there be a, a, a, a bright and very
long future for the human species.
We tend to have such a narrow view of our
place in space and in time and the, uh, the
prospect of, of making contact with extraterrestrial
intelligence works to deprovincialize our
worldview.
And I think for that reason, the search itself,
even without a success, has a great merit,
I thought I'd share just a couple of things
from my space flight experience that might
apply to this.
I was blessed to live and work in space for
104 days.
Had the opportunity to look out the window
and see earth in this just overwhelmingly
impressive way.
It certainly is a life changing experience.
And I get asked a lot did I, did I see aliens
while I was in space?
It's kinda like the bathroom question, and
you're going to get that and you know, did
you see aliens?
And I can say, not that I know of,.
But I'm interested in our panel session tonight
because I'd like to think, you know, as earthlings,
what do we have to look forward to out in
this universe when we consider life and other
places, and does it always have to be life
that's with respect to, to us, to what we
consider to be a life and intelligence?
So I'm looking forward to introducing our
panelists and getting into this, Our first
participant is the director of the Carl Sagan
Institute and a professor in astronomy at
Cornell University.
Her research focuses, focuses on modeling
new worlds and how to spot signs of life.
Please welcome Lisa Kaltenegger.
Also joining us is director of astrobiology
at Columbia University and a Global Science
Coordinator for the Earth-Life Science Institute's
Origins Network at the Tokyo Institute for
Technology.
Please welcome them here at Caleb Scharf.
Also with us tonight is a Distinguished Scholar
at the Library of Congress and a Director
of the AI, Mind and Society (AIMS) Group at
the University of Connecticut, a philosopher
and cognitive scientist.
Please welcome Susan Schneider.
Thank you.
And our final participant tonight researches
the origin of life and how to discover it
on other worlds.
She is an Assistant Professor in the School
of Earth and space exploration at Arizona
State University.
Please welcome Sara Walker.
So before we can talk about finding alien
life, we need to start with a clear operating
definition of what life is.
How do we actually define what life is? we'll
just go right down the line here.
So I think I'm going to start out, but being
a little bit cheeky because I'm an astronomer
so I don't have to give you the real definition
of what life is and most of my biology colleagues
actually tell me I'll know it when I see it.
So good luck with that because the other stars
are very far away, but we are working on it.
So to me, what's really important is there's
something that I can spot in the air of another
planet, the atmosphere.
Like we have oxygen in our own planet for
example.
Is there something that I can spot that life
does that modifies a planet its environment
enough so I can actually pick that up by looking
at that planet with my big telescope, and
so that definition encompasses a huge amount
of life, all the life that changes to signature
gases in the air of another world, and Carl
Sagan looked at our world and what he saw
was the combination of oxygen with reducing
gas like methane and that's a tell-tale sign
for a nice warm world like ours.
That life's happening right there.
And so that's what I use, but if anybody comes
up with a better definition of other gases
I can look for, I'd be more than happy to
pass this along.
We’re already on to gases.
And that was the first answer.
Yeah, so I need to, defining life is one of
those questions, I think as scientists, we
all know that you'll get 100 different answers
or you'll get a kind of blank stare.
Like really?
No.
I'm going to be a little cheeky as well, and
perhaps a little contrarian and say that you're,
in some ways I think it may be the wrong question
right now and there are a few reasons for
that.
Part of the reason is quite simple and it's
just that it's clear that what we consider
to be life is actually a confluence of multiple
phenomena in different ratios depending on
what you're talking about.
That makes it extremely complicated a question,
but I'll say two other things I think make
it a difficult question right now, and the
first is that when we think about life, we
think about life here in this room, in this
audience, on uh, on the bottom of your shoe,
whatever that has evolved after 4 billion
years.
It's the product of 4 billion years of evolution
and that may be different than whatever happened
4 billion years ago.
It may be very different to what was the first
thing or first system that we might associate
with life.
Then the other point I want to bring up is
I think we can't quite answer that question
yet because we don't know, and I think maybe
some of the other panel members may have some
insight to this, whether you can build life
out of other stuff, so whether life can be
a substrate, independent, or more universal
than we think about, not necessarily building
out of silicon or anything like that, but
building life in software.
If you could do that, it would suggest that
life is something that can happen when you
have components that can build enough complexity
for it to, for it to sort of emerge.
So that's my contrarian answer that we can't
quite answer that question of defining life
yet.
Okay.
So that's really nice.
I'm a philosopher, so definitions are always
a train wreck.
And the worry here is that if you define life
in terms of life as we know it on earth, all
cases of life that we know are related.
So we've got one instance that we know about
and so if we make a definition based on that
instance and we go look for life somewhere
else, it may be that we failed to detect life
because we've narrowed our definition so much
that we are just the tip of the iceberg.
There are all sorts of intriguing cases of
life.
So I agree with both of you, you know, to
not use a very constrained definition.
NASA's Astrobiology Institute has an intriguing
definition which I sometimes refer to, which
is a self sustaining chemical system capable
of Darwinian evolution.
I like that.
But then I kinda think again as a philosopher,
wait a second, what if AI is self-sustaining
and has all sorts of intriguing properties,
but the instance that we have is created by
intelligent design, that is we're the designers.
We make the AI systems, and it doesn't evolve
in a Darwinian fashion.
So I'm still not 100 percent behind the NASA
definition either.
I can agree with that.
I'm also not behind the NASA definition.
So I think one of the problems that we often
encounter is assuming that life is a chemical
phenomenon, and I think there's a confusion
between the scale at which life emerges, which
is probably chemical, and the definition of
life, which is likely not related to chemistry
necessarily and could apply to AI.
So I liked that Lisa brought up the, the.
I know it when I see it.
You hear this so much in the astrobiology
community and I always make this joke about
that.
Like if, if I know it, when I see it, I feel
very alive and so you guys are observing me
right now.
I guess I'm alive because you know it and
when you see it, but like if nobody is observing
me, am I still alive?
So that doesn't seem like a very good objective
criteria for science.
So I think one of the problems that we face
as astrobiologists is that our definitions
are really premature because we don't actually
have a theory for life.
Um, and so what I mean by that is I, the way
I think about living systems is really trying
to understand what is life at a fundamental
level.
And a lot of our descriptions are kind of
at this very high level where we're talking
about life being reproducing or about compartmentalization
or metabolism or chemical self-sustaining
system.
And those are probably attributes of life
but not really the core property of life.
The property that would be universal in the
sense that Caleb was talking about.
And if we think about what life is doing that's
very unique, in my mind it's information processing
capability.
And that we don't really see any other kind
of systems that use information in the way
that biology does and I think AI is an excellent
example of that.
DNA in your cells and how that information
gets read out and actually controls the function
of yourselves is another example.
And to that point, if we start thinking about
these sort of more abstract ways of thinking
about life in terms of information and the
way information interacts with the physical
world as being a way of quantifying life,
suddenly life is not this black or white.
Yes, this is alive.
No, this is not alive, but we could actually
derive measurable criteria for life and that
there's actually a spectrum of living things.
And so AI might fall in that spectrum.
Chemical Systems might fall in that spectrum,
but so might cities and multicellular organisms,
or unicellular organisms.
And so I think one of the challenges for astrobiologists
moving forward is really to challenge ourselves
to think outside the box about what life is
and what the underlying laws might be of life,
and whether there are principles that are
really universal.
Well, I liked the way...
Go ahead.
I think one of the things that I completely
agree, and this is where you get that full
scientific insight that we just like talk
and discuss and it's fun and then we trying
to come up with something, is the search that
we have going now on the thousands of other
worlds that we've found and detected does
need some kind of definitions that we figured
out what we can spot or what we could look
for.
However, what we do is we keep our eyes open
for weird stuff.
Weird stuff that we can’t explain geologically,
right, and then we'll take that and say, look,
because we have this one case earth and earth
is amazing and has a wide range of life when
we look at it, however, it could be completely
different somewhere else, but we'll only get
that when we look somewhere else, as we are
now doing, and we're trying to also recreate
life in the lab.
That's what a lot of our biologists colleagues
are trying to to work out now.
And if that would work out then we could change
the chemical mix.
But right now it's basically a two pronged
approach, I would say, looking out and trying
to figure out what we can find and what makes
no sense.
What's usually the fun in science, the eureka
moment was like, oh my God, this is nothing
I would have ever expected.
That's what we really like in a way.
We don't know what to do after.
But that's where it becomes fun.
And the other thing is like people trying
to do this theoretically and trying to do
it practically in the lab from the most basic
chemical compounds.
And I think it's really, really cool to be
alive right now because we're 2000 years,
a little bit more, people were asking whether
we're alone in the universe and we're so close
to figuring it out.
I suspect we would be asking it for 20,000,
30,000, 50,000 years.
And that's what's so cool about it.
I think that's a really nice lead in to part
two, which is finding life.
Since 1992, more than 3,500 exoplanets had
been found orbiting stars other than our sun.
And 60 percent of these are rocky planets,
not unlike ours.
So Lisa, let's start with you and the opening
film.
We heard from Carl Sagan himself about the
value of searching for life out there in the
stars.
As Director of the Sagan Institute.
Can you tell us how that search is going?
I mean, there's a lot of things going on.
So I think, one of the most fascinating things
for me, so as you were saying, about 25 years
ago, this whole thing is like are there other
planets out there, are there worlds, required
a bottle of wine and a lot of different opinions.
Right now we found nearly 4,000 worlds orbiting
other stars, alien suns.
So when you look up in the sky, doesn't work
in Manhattan, but works once you are outside.
I tried yesterday, I could find two stars.
When you're out and you actually.
Well, one thing that works in Manhattan, if
you're out and you look the sky and you count
one, two, one out of two stars or one out
of two suns that you see in the night sky
has a planet, and one out of five has a planet
that could be like ours.
And what that means is that it's small enough
to be a rock and at the right distance from
this hot star, where it's not too hot and
not too cold so you can have liquid water,
one out of five and we have 200 billion stars
in our Milky Way, our galaxy alone.
So if you do the math, we've 40 billion interesting
places to look and we have no idea whether
there is life out there because we don't have
the telescopes yet that are big enough to
actually catch the light from these planets
to check.
However we're building those and the first
one is going to launch in two years.
It's the James Webb Space Telescope.
And that one at the edge of the technical
possibility will have the capability to spot
these gases that life produces in the air
of other worlds that could be like ours.
So the search is going well so far.
I like our odds.
I have no answer and a good answer actually
if anybody ever asks you, when you come out
of this panel, for example, what the chances
are that there's life out there in the universe.
A good friend of mine, one of the discoverers
of the first exoplanets, Michel Mayor always
says 50 percent plus minus 50.
I think it's a good way to put it.
That's awesome.
That's awesome.
And we know there are a lot of other missions
that are happening as well and I hope we'll
get a chance to discuss some of them too.
Caleb, When, when you think about this, what
are the parameters for looking for life on
these exoplanets?
If you could look for what you want.
What would you be looking for?
So one of the things I'm very interested in
with my colleagues is understanding even something
as fundamental as the nature of climate.
You mentioned the idea of the planet needing
to be just at the right distance from its
parent star where it's not too hot, not too
cold.
Goldilocks zone or whatever you want to call
it, but that itself is actually a very complex
problem as, as you well know.
Uh, so for example, uh, we're trying to take
super computer simulations of planetary climate
and model alien worlds and find out what happens
when you change the day length of a planet.
What happens when you change the tilt of the
planet, what happens when you change the shape
of the orbit, what happens when you change
the gravity of a planet?
And so on.
And it turns out to be a difficult problem
Yeah no kidding
Just to answer whether or not the surface
environment of a planet, maybe temperate,
which is kind of one of our methods of selecting
out candidate planets for then trying to probe
deeper with these, these great new telescopes
looking for chemical signatures and so on.
You kind of need to know the, the thermal
environment, the climate environment.
Um, so I can give you an example of what happens
when you slow a planet like the earth down.
You might think.
Well, what, how that change climate will actually
completely alters the circulation patterns
of the atmosphere on a planet.
And our models contain oceans and atmospheres
and chemistry and salt, and we're finding
that you change the rotation rate of a planet,
you actually warm up the poles and you cool
down the equator, but you also do other things.
If the planet has water, it begins to build
certain patterns of cloud that play a role
in reflecting stellar radiation, for reflecting
sunlight back out into space.
And that also plays a role in setting the
climate state.
So the bottom line is we're trying to come
at this problem from many different directions
and it's all complicated.
Uh, which is good in the sense because we
have jobs to do.
If it was easy, we wouldn't be doing it.
Um, so some, some of the parameters are the
raw sort of biochemical signatures, but other
parameters have to do with just understanding
that the environment, the climate state of
a planet.
And that's a challenge.
Yeah, that's.
Sorry, go ahead.
So what was, what Caleb was saying.
And that's absolutely true.
So we have a different approach to this, right?
So that we have many, many groups who have
this climate model that was done for the earth.
so we have one at the Carl Sagan Institute,
you've one with several where we basically
making a huge data cube, if you want, where
we're actually making our models do things
for a longer day lengths, for bigger gravity.
But the problem that we're encountering of
course is that we have no data sample that
you can compare that to because we don't have
an earth that happens to be heavier, right?
We have some information about an earth that's
younger and we have this amazing artists'
impression that you see behind us of what
these planets that we've discovered or that
astronomers have discovered, could be like.
Some have one sun, some have two suns, the
suns up there.
And man, try to model the climate of the earth
and put a second sun in.
This model was never designed to have two
suns because earth was never designed to two
suns in a way, so we're getting a lot of insights
and the question really is also if the climate,
when could we find the signs of life even
if they exist, some climate conditions will
actually make it impossible for us to spot
them, and some climate conditions will make
it easier for us to spot them.
And with thousands of planets out there, what
we're trying to do is pick the easiest ones
to tease this out, and one last point is that
when Caleb and I were talking about the habitable
zone, there's no way to say that outside of
the zone, there couldn't be life.
There could be life on icy moons, for example,
like Europa on Solidus, but it would be hidden
from our view because this ice layer would
basically keep all the gases, the only thing
that we can really see from far, far away
hidden from our telescopes.
We'd have to go there, drill a hole and check
if there are fish or anything else, but so
this is why this definition of the habitable
zone, just to make sure, it's not where there
can be life, it's where we without going there
can pick it up if it exists.
Just to add one tiny little interesting piece
too that.
You mentioned the icy moons, and that's absolutely
an essential thing to remember because if
you look at our solar system, we have this
picture of this little oasis world.
I think one of those posters talks about the
oasis earth sitting closer to the sun, but
if, for example, having liquid water oceans
defines an oasis, then actually the majority
liquid water oceans in our solar system are
in the outer solar system.
If you add up all the potential liquid water
inside Europa, inside Enceladus, inside even
Titan, and possibly even Pluto, it's about
13 times the total volume of liquid water
on earth.
Except it's in these dark oceans, these ocean
sea, all the way by icy crusts.
So for all we know our solar system is teeming
with more life, but it's locked away in these
dark oceans.
so Sara we have the potential with places
like Mars where we might actually be able
to get there someday.
But I guess I'd like to ask you, you know,
you got the Mars 2020 and the Exo Mars 2020
rovers that are going to get a much closer
look at the surface of Mars than we've ever
had before.
So what should they be looking for?
Um, and what do you expect they'll find?
I'm not convinced there's life on Mars actually.
Well, that's what I think that's an okay answer
actually.
So I think Mars is fascinating.
But, um, but I've been really intrigued with
this idea that life um really needs to take
over an entire planet.
And so if you look at life on earth, everything
about the earth's system is defined by the
presence of life in some sense, even like
the biogeochemical cycles.
So the cycling of elements is controlled by
life.
And that's something really fascinating about
what humans are doing now as we're starting
to control those, those biogeochemical cycles.
Um, so if you, if you look at something like
the models that we think Caleb, we're talking
about, one of the things I felt really intriguing
hearing about those is we don't even know
how to model earth without life, right?
Um, and so I think this idea that, that, that
life really becomes embedded in a planet is
really fascinating.
Um, and I guess this idea about, um, back
to like thinking about definitions of life
and what we're actually looking for.
We think of life as this, this chemical phenomena
and a cell as the fundamental unit for life
and so we should be looking for cells on Mars,
but that may be too narrow a view, and if
you do have this kind of expanded view and
are really looking for more fundamental basic
processes of life, it really opens your horizons
for things that you might look for.
And so when I think about looking for life,
I'm not really thinking about looking for
cells on a planet or molecules in an atmosphere.
I think about looking for an entirely new
sector of physics and that seems like kind
of an unusual way of thinking about it.
But.
But we have some really amazing mathematical
theories of the world.
We have quantum mechanics and general activity
and these amazing revolutions and our understanding
of the natural world.
And we don't have any theories that explain
the existence of life or the properties of
life.
And so I really think it's, it's a new frontier
for us in astrobiology to really understand
as combining observations and experiments
that we're doing here on earth and really
think differently about what kind of things
we're looking for.
And so when I think about looking for life,
I think about what are the mathematical structures
that we use to describe life on earth that
we should be thinking about, how to look for
those on other planets.
Um, and one of the ways that that has been
really incredibly successful in studying life
across all scales for life on earth is this
idea of using networks.
Um, and so, um, so probably everybody in here
is part of a social network, right?
Is anybody here a part of a social network?
Everybody?
Raise your hand.
At least one, you're in a room with people.
So you're in a social network, but you're
probably also in a social network online.
And you can actually represent networks mathematically
and, and they're, they're quite simple mathematical
structures.
Um, everybody in this room would be representatives
of a circle and if you're friends with each
other, you'd have a line between you and you
can actually study the statistics of those
kinds of systems.
Um, and this is really interesting because
if you look at systems like the chemistry
happening in yourselves or the structure of
the internet or the structure of Facebook,
there's a lot of regularities in the, in the
way those networks are structured and a lot
of that has to do with the way information
is structuring those systems.
So, so if you think about a social network,
really, you're not interacting with those
people physically, you're interacting with
them through, through information technology
or some kind of information exchange.
And so what I find intriguing is trying to
actually think about how we can use insights
from complex systems to look for life on earth
in particular, um, maybe, um, you know, Mars
atmosphere or atmospheres of other planets
might have some signatures in the actual system
level organization of the planet.
Um, and what I mean by that is you could actually
just like, we can represent chemistry.
Um, so, so the way we represent chemistry
and yourselves as a network, as we say, the
molecules interact, so they would be the nodes
in the network and if they participate in
a reaction together, then they have a line
between them.
Um, and so you can represent an atmosphere
that way too.
It's just chemistry.
It has the same kind of mathematical representation.
And so some people have done some preliminary
studies where they show Earth's atmosphere.
It looks more like the chemistry inside your
cells than it does like Mars or Venus's atmosphere
from this network perspective.
Now that has a lot of work to be done to confirm
that this is really like a system level property
of atmospheres of inhabited planets.
But if it is, it gives us a better window
into thinking about what our biological systems
at a planetary scale, how do they shape planetary
scale structure of the chemistry, and how
can we actually use that as a bio signature
that's not just dependent on the particular
molecules participating in those networks,
but actually the system level organization.
And so one of the ways that I tend to think
about that, why looking at individual molecules
is bad, but maybe looking at system level
properties is good for detecting life is you're
all made of atoms in this room, right?
But you wouldn't think of any individual atom
in your body is alive, but you as a whole
system level entity are alive.
So it ought, it clearly has to be an emergent
property of many interacting molecules.
Um, and so I think one of the things that
we need to start doing is actually start using
those kinds of tools for thinking about our
search for life.
It gets hard with exoplanets because you get
so little data.
Drives me nuts how little data-
So, so one of the things I find challenging
for the future, so think like how do we actually
extract these kind of properties from that
data?
Um, but I think that there are new horizons
for thinking about how we search for life
that aren't just the way that we've been thinking
about it in the past.
Um, and it really comes from trying to think
more quantifiably about the search.
I think that actually leads Caleb into, you
know, this consideration for the Fermi paradox
and which can be, you know, really with the
question of where is everybody, you know,
where, I mean, where is everybody and who,
who should we be looking at, you know, and
um, you know, this, this idea is the answer
to the Drake question zero.
so maybe I'll just state what the Fermi paradox
is.
And then then we have a little, uh, I think
we have a little movie to show.
So the Fermi paradox is this idea that if
there is life out there, if life happens reasonably
often in our galaxy, for example, then our
galaxy is pretty old, it's at least 10 billion
years old.
And so following our own trajectory, there's
been plenty of time for some species out there
to have come into existence, if it's being
lucky or unlucky, depending on your perspective,
it became intelligent and technological and
decided to try to go between the stars.
And the interesting thing about that is it
turns out that once you start doing that,
you occupy the galaxy pretty quickly.
And so this raises the question, if life is
not incredibly rare or if there isn't something
that prevents it from doing this, and where
is everybody?
Why hasn't it shown up?
Now?
Of course some people feel it has shown up,
but we won't go there.
That's a different question.
Um, so to give us, to illustrate this, I don't
know if we have the little Fermi video ready.
Yeah.
So let me explain what this is.
This is actually the work of Jonathan Carol
Neylanbach and Adam Frank, who I've been working
with, and this is a picture of our galaxy,
but it's a highly idealized model of our galaxy.
What you're looking at, each little point
of light, each little sphere represents about
two and a half million stars and the colors
correspond to interstellar species relocating
themselves, expanding, I, I would say colonizing,
but that word have such negative connotation
these days.
Uh, they're, they're, they're expanding out.
Each color corresponds to particular technological
species.
Now, what you're seeing in this representation
is a pretty active galaxy.
It's colorful.
In the middle, things come and go because
there are things like supernova that go off
and essentially sterilize big pieces of our
galaxy.
So civilizations in the middle of our galaxy
kind of like building a house in Hawaii.
It's like, yeah, this looks good.
I know there's a volcano, but you know, and
that maybe something that happens in the center
of our galaxy where there're many more stars,
many more supernova and other violent events
that might actually sterilize pieces of the
galaxy.
Now this is an exaggerated model.
The part of the reason for looking at this
question this way is that things move around
in our galaxy and stars have motion and that
actually encourages the spread of an interstellar
species because you may not have to have such
wonderful rocket ships to go between stars
if the stars themselves every so often come
closer to each other.
So that's part of what we were trying to model.
It's a very exaggerated model because in that
40 million years that you just saw passing,
we assume that species can travel about half
the speed of light when they decide to, but
even if you tune it down, and you make it
much more difficult to travel between the
stars, and you make the occurrence of star-faring
species much less frequent, you still discover
that it still is pretty easy to fill the galaxy
with life.
So the bottom line is it reinforces this big
open question of where is everybody?
So that's essentially the Fermi paradox brought
up to date.
I'll be contrarians.
Excellent.
So the point is that I teach astronomy 101,
so I have like undergrad students with no
science major.
Uh, one of the questions that I asked, we
asked them when we get to the Fermi paradox,
so Fermi basically decided that his answer
was that the speed of light is our limit and
so you'd have to be incredibly motivated,
or have a really good reason why you'd want
to spend so much of your time.
Like our closest star after the sun is four
light years away.
So if you could go with 10 percent the speed
of light, it's still a 40 year travel that
you have to survive.
You have to have energy and food for and you
have to have a very good reason to go, right?
But what I do in my class, when we get to
the Fermi paradox and to the Drake equation
and saying, look, I have this amount of money
and we can go to one planet.
Let's assume the whole galaxy's teaming with
them.
I have one planet that is 5000 years older
than us and one planet that's 5000 years younger.
And then I poll my class and say which one
should I spend my money on to go and visit?
And most of the time to always, except for
one person who always wants to go back in
time because they're scared about something
new, everyone wants to go to the further developed
one because they want to know what's going
on.
And then if you take that, I love our planet,
I love our species, I think the astronauts
are amazing, you know, let me say that.
But we only made it to the moon with people,
right?
We made it with a rover to Mars.
It was great.
And to Titan with a satellite that we land
in and so on, but we are really not that interesting
assuming there's lots of places you could
choose from.
So I think we're just incredibly boring.
I love our planet.
I said that before.
I want to be nowhere else.
I think Susan is going to have something to
say about this.
But just before that, just to say, one issue
is you're introducing the factor of agency.
We try to avoid that in our modeling because
we have no idea what agency is going to be
for other organisms or for other species.
Oh, just a quick comment.
So we are boring probably.
We're a relatively young planet and you know,
if there are truly are alien technological
civilizations, they could be, you know, 50
million years older than us, so we may not
know what to look for.
But I do think it's interesting though that,
you know, we do tend to think of this issue
in terms of this model of galactic expansion.
It's called the coral model, right?
Where we start in one spot and then we send
out maybe Von Neumann probes which are AIs
or spaceships in the old fashioned way, and
then they send out their ships and we expand,
but that's highly anthropomorphic.
But intriguingly we have already started interstellar
missions.
We have Project Breakthrough Starshot, which
in I believe 20 years is aiming to go to the
Alpha Centauri region and I think the speed
that they're anticipating, if things work
out.
I mean there's issues like space dust when
you're.
I think the way they do it is that they're
incredibly small, they're so light that they
can go very, very fast.
These little light sail ships.
But the point here is if you do want to expand
in this way, even we have the resources to
begin to at least examine these other regions
fairly cheaply.
I mean, each ship is fairly inexpensive.
Of course it takes a lot of energy to send
the ships out.
But I think the question here is, will, are
we being too anthropomorphic when we think
of the Fermi paradox, I mean, we're thinking
of galactic expansion, but these civilizations
that are perhaps 50 million years older than
us are thinking entirely differently than
we are.
So who knows, maybe they have already visited
and we just don't know.
I hope one porter's call.
Don't take that wrong, okay?
I mean by our meek intellectual resources,
there are dozens of intriguing responses to
the Fermi paradox, but there's been nothing
that convinced me, uh, you know, either way.
I am actually, well, interested in asking
Sara a question about the sort of information
approach to life, networks, and so on.
We automatically kind of think of it as, oh,
life, will it's stuff here.
But could it be applied on a much grander
scale to understand something like the Fermi
paradox?
I hope so.
So I was first going to disagree with all
of you because they don't think we're boring.
I think we are fascinating, just so you know,
there's one person on the panel that doesn't
think we're boring.
I think we are the most fascinating thing
in the universe.
It's really crazy that, that we're here having
this conversation right now.
Um, but from the perspective of the Fermi
Paradox, I mean, my resolution is, is very
similar to Susan's.
I just, I think we don't know what we're looking
for and if we, if we understand life on earth
better, um, and we do, we develop these kind
of quantifiable criteria to answer your question,
then we should be able to identify it.
And it might be that we identify in completely
different ways than we had anticipated previously.
Um, and so one of the things that, oh, I made
this argument before, that, that life isn't
a chemical phenomena.
Um, and I, I really do think it's not.
So when I say that, like cities are alive,
I really think cities are alive and I think
computers are alive and I think AI is his
life.
And so these are all examples of the same
kind of information mattering to the world
and reemerging at different scales, and we
don't really know how high up in a hierarchy
that goes.
We know that that chemistry organized into
unicellular organisms, and that those organized
into multicellular organisms.
And then we had social systems, and then we
had cities, and we have technological civilization
that's now globally integrated, and now we're
inventing artificial intelligence.
And so hi, how, how many scales are there
to that kind of of living process and hierarchy?
And some very advanced life could look entirely
different than anything that we could anticipate
right now or life in different media could
look entirely different.
It doesn't need to be the kind of chemistry
that we have on earth today.
So I think what we really need to understand
is what is, what life is and what it's doing
before we can really ask and rule out possibilities.
I think just, as a very short thing, I think
I completely agree that we're just a little
bit too Earth-centric, right?
Because maybe if we evolve a little further,
we're actually going to be fine with the energy
and the resources we have.
We're going to actually manage them, right,
because usually colonization or moving out
is because you're running out of resources,
you need something else.
And in addition, 75 percent of all the stars
out there are small red stars who have a much,
much longer lifetime than the sun so they
don't have to go anywhere to find somewhere
else.
We do.
And so this is why I love the astronaut program.
That's what I said before.
We have about a billion years on this planet
before because the sun, like every other star
gets brighter with time.
It's just what they do.
It's going to get hotter on the earth.
So even without us amplifying the CO2, we
can speed the process up, but even if we don't
then in about a billion years it's gonna be
way too hot here.
So we going lose the surface oceans with all
the models that we're running and so we'd
have to be either a space faring species at
that point to go somewhere else to build hopefully
one of these amazing space station that I
keep seeing in the science fiction movies
and I really want to live in one of those.
And you could think about a space station
being Paris, one London, one New York, and
shuttling in between, right?
I have no problem.
I don't need another planet if that's the
case.
But I think a lot of the time, you know, because
the Fermi paradox and the Drake equation were
this amazing first attempts to quantify the
problem, but I think it's also deeply rooted
in our idea that we won't get our resources
sorted out, that we will have to expand to
survive and that everyone does.
And so I'm very much with Susan hopefully
that if 50 million year older civilization
or or you know the numbers are staggering.
They could be 6 billion years older than we
are, so older than us when the earth was born,
right?
So it's not even something I can imagine,
but I do hope, I'm a positive or I'm an optimist
for humankind and civilization.
I hope we get our energy and resources sorted
and then we wouldn't have to expand.
We will go and find out because we are curious.
We could travel but we wouldn't have to colonize
and therefore this whole idea that you would
spread over the whole galaxy to actually make
it yours might not appeal to us because I
think some of us in the audience, right?
If you see a place where you'd love to live,
but you see somebody else has built a house
there, I'm not going to go and actually push
it down and say, no, I'm here.
And I hope as a species we evolve to that
system too and so we have our amazing planet
and oasis in space.
Maybe we don't need to occupy everything else.
I agree with a lot of that.
I mean, I think the one thing is though, this
is often an argument I use when people ask
me, well, why do you study things like astrobiology
and life and universe out there?
Because it's the way we're going to learn
about ourselves and I just wonder whether
part of the motivation for spreading across
the universe is you're still looking for answers
about yourself and you may never be able to
find all of those by staying at home.
I just, just, just to put that out there.
Yeah.
If we accept that there is life out there.
Let's talk about whether or not that life
might be intelligent, whatever that means.
So what does that mean?
I think one of the things that's very interesting
about us as an intelligent civilization is
that we construct theories of, of our world
and we can, in the like, laws and we can use
those to do really interesting things like
launch satellites into space or people into
space.
Um, and so, so, so theories themselves are
actually information about the world and they're
information that allows us to do things.
And so that's one way that I actually define
intelligence is when you start having things
that, the, that, that those systems actually
have knowledge or information that allows
them to generate structures that wouldn't
be possible without having knowledge.
There is no possibility that you would have
all those satellites orbiting our planet unless
we had a technological civilization with intelligence
and knowledge about the laws of physics.
So when we're thinking about looking for intelligent
life out there, I think what we need to look
for is things that can't be explained by physics
and chemistry alone, but require additional
information in the system to actually generate
those structures.
Now, as I'm saying that, I have no idea what
the heck that means, but I think that we need
to think about that kind of perspective.
Um, in order to really clarify the questions
that we're asking.
So we're, we're at this point in the program
where we're going to transition to part four,
which is life in the future.
we have this idea that we're going to make
AI alive, and is that an okay thing to think
about?
So what we're seeing on earth right now with
the development of artificial intelligence
is a revolution, and it's changed all of our
lives.
We're on the Internet.
We have our smartphones.
We'll soon have very sophisticated personal
assistants.
I mean in a blip.
When you look at the cosmic scale of things,
it's a blip.
We will, you know, within a hundred years,
start upgrading our own intelligences to where
we may actually be post biological, we could
become cyborgs if you will, instead of carrying
around a phone, it will be in the head, we'll
have mobile internet connections, we'll have
enhanced working memories, we'll learn languages
quickly because we may just get a new neural
implant.
It could look like science fiction.
Well, if that's the trend that we see on earth,
people have increasingly started asking what
alien civilizations could be like if life
does survive on other planets past its technological
maturity.
That is, if they don't have terrible problems
like nuclear wars or you know, environmental
catastrophes, they may have the opportunity
to become synthetic beings.
Intelligence is realized in a lot of different
ways as people here appreciate.
The same sort of neural algorithms could be
run as Sara knows in a different substrate.
We see intelligence systems that are silicon
based, for example, on earth.
So all this suggest to a certain degree that
when we're searching for intelligent alien
civilizations, the little green man or ET
model, as much as I like Yoda, it's my favorite
alien.
That's not necessarily what we want to be
looking for, when we're looking for technological
civilizations.
We might be looking for synthetic intelligences
that are computroniums the size of a planet.
There are a lot of moral and ethical issues
to think about here.
Um, they may not be conscious.
I consider that an empirical question.
It may not feel like anything to be them,
if they're synthetic.
We may find out answers to these questions
as we develop our own AIs on earth.
That's not to say however the intelligent
civilizations are out there.
Um, one thing that didn't come up in response
to the Fermi paradox that I thought I think
of is incredibly interesting is the idea of
the great filter.
So there's, this is called the great filter
argument by the economist Robin Hanson, and
he suggests essentially that, you know, we
don't even know how easy it is to find life.
I mean to actually get life kickstarted on
another planet because we don't know how really
what to say about the origin of life on earth.
So we actually don't know, given all those
exoplanets, how many places are actually inhabited
because we don't know how easy it is for life
to get going.
But suppose you do have microbial life on
these planets.
Well, how difficult is it to get from microbial
to more complex forms of life?
And then from there, how difficult is it to
get to intelligent life?
And then from there, how long, how possible
is it to survive technological maturity?
And we have nuclear war, superintelligent
AI, all kinds of global catastrophic risks
that our civilization faces.
And maybe it's that way for other civilizations,
so Hanson suggests there could be a great
filter anywhere at all from the very beginning,
from the inception of life on a planet to
highly intelligent life.
So I think these are the kinds of issues which
are interesting to think about when it comes
to things like the Fermi paradox.
And, you know, Sara, with the idea of looking
for complex systems and these networks, um,
would you consider AI to be life based on,
based on that?
I definitely do.
So, so I think that the post biological phase
of evolution is really interesting, but people
tend to think it's really different than what
we've seen in the history of life so far.
But if you adopt sort of this informational
perspective of life, it seems like the natural
consequence of the way life evolves on a planet
that if it is increasingly building better
information processing systems, that that
would be an inevitable outcome.
And it's not that it's an unnatural one or
that it's a bad one.
It's just what happens.
And so I think, I think that we tend to be
afraid of these things, but I don't, I don't
think that we should be afraid of artificial
intelligence.
I think it's, it's just a part of what we
are and who we are and, and in some sense
that those systems will be our progeny in
the longterm future and they may be biologically
integrated, they may be entirely artificial,
but they are still something that we created
that we will send out into the universe.
And so something I find really intriguing
about this discovery of alien life is, is
that it might be very likely that the things
that we discover are artificial, but also
what's discovering them is artificial because
we don't usually send humans out into space.
We're sending machines and we're probably
going to be sending machine learning algorithms
and AI out into space.
So really when we're talking about making
alien contact, it might not even be biological.
It's going to be our artificial systems making
contact with other artificial systems.
And will they consider ours alive?
Yeah.
They might, I don't know.
Hopefully.It reasons some interesting ethical
questions.
It's really interesting, yeah.
So maybe just to inject,
Do it
Be a little contrarian.
So as I'm sitting here listening to this,
what I'm, what I'm realizing is, you know,
in a lot of these discussions to do with things
like the great filter and also the Fermi paradox
and spreading around space that there seems
like there's this implicit assumption that
species remain the same.
And, and you mentioned, you know, earth in
a billion years when the sun has gotten a
bit hotter and our planet has this runaway
greenhouse and we're all dead, we want to
beat that.
Evolution will have taken care of that.
Evolution itself might be the filter because
we're not static, no matter how much we might
imagine ourselves, you know, a million years
in the future, humans in the future, we will
not be the same biological entities that we
are now, neither will our machines be the
same machines that they are now.
Evolution is perhaps the most unstoppable
force in the universe.
And so I just wonder, you know, if we're talking
about life in the future, um, you know, it's
going to be totally different than anything
that exists right now.
I think we can say that with certainty
even as us.
We won't be around.
Even despite our best intentions.
Right.
We can, we can solve our energy problems,
we can, you know, write records of everything
we have, literature and so on.
Biologically, I, I'm not sure it's either
possible or desirable to hold our biological
evolution and evolution, Darwinian evolution
happens at multiple times scales.
It's happening right now, like that.
It's also happening over millions of years
and it's very, very difficult to see where
it's going.
So I think, you know, part of what's happening
is we're kind of, we're getting to this point
where, well, humans in the future, we wouldn't
be humans anymore, we will be something else,
But that doesn't mean we shouldn't be, protecting
what allows us to survive here.
Absolutely.
Absolutely.
Because the times go maybe very long, but
this may also have something to say about
the Fermi paradox, about the great filter
that it's actually evolution that, that just,
that aggressively expanding species.
It takes it still 10 million years to get
anywhere interesting in the galaxy.
By that time, it's done that.
It's not the same species.
Yeah.
Just to that point, there is this like intrinsic
need to be the same.
But like, but the thing that always strikes
me as really interesting is we aren't physically
the same as we were like 10 years ago.
I mean, literally like the atoms in your body
are not the same atoms.
I'm not for sure though.
So what we think about as being the same is
very subjective.
Um, and so, so I think, I think Caleb's absolutely
right that we are continually evolving systems
and we're systems that were information is
constantly restructuring us.
So, so the reason that you're still, you know,
a coherent entity 10 years later, even though
you don't have the same atoms is because your
body is constantly rebuilding itself.
And so an evolution just does that on a different
timescale.
It builds new systems from the previous systems
and that's totally fine.
So I think, I think our definition of what
we are needs to be expanded and that's one
of the reasons that I like this idea of thinking
about life at a planetary scale because we
are all life on earth and it's very integrated
as you were describing before, we can't really
take out a piece of it and say it's separate.
Um, and so when we're thinking about the evolution
of life on this planet, we have to think of
that entire planetary life evolving.
And we're definitely gonna evolve into something
else in the future and probably AI is going
to be tightly integrated with, that and we
don't know what that's gonna look like, but,
but it's not not going to be us.
It's still going to be the same lineage.
Yeah.
Susan.
I'd like astrobiologists so much because you’re
so laid back about the next 200 years because
you think of everything in these grand timescales.
But I think we have to remember that, um,
we right now have a lot of issues with emerging
technologies that urgently need to be navigated
so that we do press on and that we can make
decisions about how to design minds, if you
will.
So Caleb, you talk about it all being a matter
of evolution in a Darwinian sense.
But even Richard Dawkins said recently in
a film that we were both in called Super Sapiens
when it comes to artificial intelligence and
brain enhancement, it is now the era of intelligent
design.
We are the designers,
Which is why I think the idea of being earthlings
is so important.
If we're looking at ourselves as this planetary
system, it's not just me deciding.
It's not just you deciding.
It's as, as this the inhabitants of this planet,
we have to decide how are we going to work
together for that future that I'd like to
think, you know, my son who's only 15, he's
got his life to live and you know, and yeah,
there's this grander scale of time that where
we all change and all that happens, but I
want to know that, you know, as human beings,
we're going to figure out how we survive here
too.
I mean, it's a bit of a stretch, but this
is another motivation for finding other life
in the universe.
This story may have played out many, many
times before.
And if we ever got to the point where we could
interrogate, maybe not interrogate necessarily
in the sense of a conversation,
On a surgery table, lets not do that
but interrogate from afar by observation,
whether it's understanding even the detailed
chemistry of a planetary atmosphere tells
us what mistakes they made, the pollutants
in the atmosphere and so on.
You know, there are other stories out there
potentially that could tell us how to do things
and actually make it through this augmentation
period or make it through a filter.
You know, there may be other places where
it worked and places where it failed and we
could learn from that too.
That's a stretch, but
I think Nicole, in the beginning of this,
you asked why we should care, for example,
if we don't find life out there, what, what
our reasons would be?
And I think Caleb just touched on one of those,
uh, by finding other planets like ours out
there, we'll find some that are older than
us.
And even if evolution is different, let's
say some will be in a further evolutionary
stage than we're.
And that is the only way that allows us to
glimpse in our potential future.
And the way I usually talk about this is like,
for example, we see all older earths have
a lot of SO2 in the atmosphere.
Comes from volcanoes.
We can’t breathe it.
That doesn't mean it will happen to the Earth,
but it wouldn't mean that it would be intelligent
for us to develop a technology to filter it
out just in case this is something that happens
to all earths.
And so even if people don't about whether
we’re alone in the universe, what's coming,
being as informed as we can, whether we become
synthetic or not, taking as good care as we
can of our own planet, I think is the imperative
that right now we are guarding this on it
and we are responsible for it.
I, I love that as kind of a closing note because
when we think about exploring further off
our planet, finding or not finding what we
consider life to be out there, we know from
what we've done already, even in low earth
orbit and as human beings only getting to
the moon so far, that we have learned a lot
about ourselves and about how, how we do those
things to improve life here on Earth.
But I want to thank all of you for a really,
really impressive conversation.
Thank you.
