>> Dan Turello: Welcome.
I'm Dan Turello with
the Kluge Center
at the Library of Congress.
The title of today's program
is Artificial Intelligence
in the Search for
Life in the Universe.
With us to talk about these
issues are Sara Imari Walker.
She's a theoretical
physicist and astrobiologist
and associate professor
at the School of Earth
and Space Exploration at
Arizona State University.
Also with us is Caleb Scharf.
He is the Director of
the Astrobiology Center
at Columbia University,
where he studies cosmology,
exoplanetary science and the
search for life in the universe.
Moderating their conversation
will be Susan Schneider.
Susan is the William F.
Dietrich Distinguished Professor
of Philosophy at Florida
Atlantic University,
and the Founding Director of a
Center on the Future of Mind.
The past year, Susan has also
been the Baruch Blumberg NASA
Library of Congress
Chair in Astrobiology
in residence at the
Kluge Center.
This program is a
collaboration between NASA
and the Library of Congress.
And it's designed
to focus attention
on the societal dimension and
implications of the search
for life in the cosmos.
Susan is a philosopher of
consciousness of the mind.
And one of the questions she's
been investigating is what would
it look like if we were
to find that other minds
in the universe are actually
post-biological in nature?
So, these are the
questions we're going
to be hearing more about today.
Caleb, Sara, Susan,
thanks for being with us.
And Susan, over to you.
>> Susan Schneider: Hello.
And Dan, thank you for
the kind introduction.
I've had so much fun this year
at the Kluge Center and working
with NASA in the
Library of Congress.
And I'm so thrilled to
be talking with Caleb
and Sara today about
a constellation
of issues involving
artificial intelligence,
the search for life, and more.
And with that said, what I'd
like to do is just quickly
start the discussion
with a question for Sara.
Sara, it's a very easy question.
I'm just kidding.
I want to know what is life.
>> Sara Imari Walker:
Oh, don't we all.
I want to know what it is too.
Yeah, so I think, you
know, people have thought
about this a lot
of different ways.
But for me, it really breaks
down to what problems we haven't
been able to really answer
from a fundamental
perspective yet.
So, physics has been really
good at describing, you know,
behavior of elementary particles
and the large scale
structure of the universe.
But I think it hasn't
come anywhere close
to predicting things like living
things or thinking things.
And really part of the huge
conceptual gap there is related
to the fact that living
entities and anything
that like produces really
is a product of information
and how information operates
in the physical world,
or at least that's sort
of my perspective on it.
So, when I think
about what life is,
it has to be associated
somehow with the fact
that information actually
is a real physical thing,
can really physically exist
in our universe, and
has consequences.
So, the thing that's kind of
exciting there about thinking
about what life is is if you
kind of take this approach
that there are certain
objects in the universe,
like my water bottle,
that require an evolutionary
information processing for us
to produce them eventually, you
get kind of a new conception
of life in terms of, you
know, when life emerges
in the universe, it's this
process whereby information
starts structural matter
across space and time,
and that becomes this
evolutionary process
that creates all of these
subsequent structures.
And so that's sort
of what I think
about when I think what is life.
Origins of life as a transition
to this kind of physics
where information matters,
and the evolution of life is
that expansion of that process
in space and time to take
over more and more matter
and do interesting thing.
>> Susan Schneider: Interesting.
And so on that last
definition of life,
I suppose artificial
intelligence would be a form
of life.
>> Sara Imari Walker: Yes, it
is definitely a form of life.
So, I know I just keep my water
bottle as an example of life,
which I always do,
but it's actually just
because it requires
information to produce it.
But there are also
things that are alive,
which are information processing
entities, like ourselves
that actually do
this kind of process
of actively using information.
And I think artificial
intelligence is definitely
on that spectrum of things that
are life, or produced by life.
And so yes, they are alive.
>> Susan Schneider: So,
that really makes me wonder,
and this is to Caleb,
what is out there?
Tell us about the search for
life, beginning with the,
you know, exoplanets, and
talking about microbial life.
And then perhaps a
little speculatively,
what about intelligent life?
>> Caleb Scharf: Yeah,
well, listening to Sara,
it also made me think
that astrobiology,
the quest to find
life [inaudible] we,
we always have a more naive
actionable kind of definition
of life, which I
think is a subset
of what Sara was talking about.
We think about how do we know
that there's life on Mars,
or in the atmosphere of
Venus, or on an exoplanet
around another star, and we
ask much simpler questions.
So, the interesting thing about
this field of looking for life
in the universe is how much it's
changed in the last 25 years.
Twenty five years
ago, we didn't know
that there would
be many planets,
if any, around other stars.
We now know that to be,
we now know that there
are essentially planets
around every star
in the universe.
And a significant fraction with
those may be potential harbors
for the complex information
process in chemistry
that we associate with life.
You know, to speak to your
question about how close we are
to finding stuff, I'm not sure.
I wish I knew when we were going
to find irrefutable evidence
of life beyond the Earth.
It may be that we find
something in our Solar System.
And the interesting question
there will be whether
or not it's related to
us in some way, whether
or not the process
of life happening
in this one little corner of the
universe is all interrelated.
It's, you know, the
origin [inaudible] spread
across multiple worlds.
You know, mostly what we look
for these days is microbial life
or evidence of life having
manipulated its environment
in some way.
And what's interesting
about that is
that it does actually
extend to the question
of more intelligent life,
inasmuch as there's a resurgence
of interest in the idea
of technosignatures.
So, on one hand, we talk
about biosignatures,
those actionable signs of
evidence of life on other worlds
in terms of chemical
alterations and environment.
But increasingly,
we're also interested
in so called technosignatures.
And, again, this meshes
really beautifully
with what Sara was talking
about, this conception of,
you know, the underlying
secret sources information
and self propagating information
that fills available niches
in the universe by
restructuring matter.
And technosignatures are
restructuring of matter.
So, like Sara's water bottle.
Or if we place satellites in
orbit, or we put solar panels
on our planet, those
would be construed
as sort of technosignatures.
So, we might feel there's
actually a lot of interest
in now not just looking for
signs of microbes out there,
but looking for technological
signatures,
repurposing of matter in aid
of let's say intelligence
for want of a better word.
>> Susan Schneider: Fascinating.
So, you know, it's a
tricky issue, isn't it?
It reminds me of when I talk to
Seth Shostak over at SETI about,
you know, how do we look for
post biological intelligence?
You know, the next civilization
that is closest to us is say,
you know, vastly older and
vastly smarter than us,
which very well could
be the case.
How would we even find a
technosignature that predicted,
I mean, that was predictive,
that wasn't just a reflection
of our, you know,
miniscule technology?
And he said, well, the
intellectual difference
between us and them could
be like the difference
between us and, you know, our
pets, our goldfish, for example.
So, what kind
of a technosignature could we
humble beings even hope to find?
>> Caleb Scharf: Is that a
question for me or for Sara?
>> Susan Schneider: So, I
would say for both of you.
Whoever wants to jump in.
>> Caleb Scharf: I can start.
>> Sara Imari Walker: Sure.
>> Caleb Scharf:
I think, you know,
part of the challenge
is we know what we know.
We don't know what
we don't know.
And so a lot of the
basis for looking
for technosignatures comes
out of pretty fundamental
notions about,
for example, energy use.
So, for instance, the famous
thing called Dyson sphere,
which is this idea
that at some point
if a civilization grows
sufficiently, continues actually
with the sort of growth
rate that we've had
for another few thousand
years, it would get to a point
where it would require
so much energy
that you would actually have
to restructure your
energy capturing apparatus.
For example, in the form of a
Dyson sphere, which is assembly
of structures capturing more
and more of the energy coming
from the Sun, or any star.
Structures like that have to
obey the laws of thermodynamics.
And so one of the things
we look for is evidence
of essentially waste heat.
You cannot utilize energy
without producing a
certain amount of,
for want of a better
word, waste, heat,
[inaudible], emission.
And so people have
seriously looked for that
as one possible signature.
Sara may have other
ideas as well.
>> Sara Imari Walker: Yeah.
I think something that's
underappreciated is that a lot
of the same problems that plague
technosignatures also plague
biosignatures, which is that
we just don't know what we're
looking for.
So, there's kind of this
implicit assumption we have
that we're going to
recognize life when we see it
or we'll recognize
technology when we see it.
And the truth of
the matter is we,
we don't know what
those things are.
I think that's one
of the reasons
that I'm really motivated
by this idea of trying
to think more about the abstract
principles underlying what life
or intelligence is.
And from that perspective,
and this kind
of more theory driven
approach that we're trying
to take thinking about
physics of information,
really what you want
there is objects
that don't have a
natural explanation.
Right?
Like, like they can't
be described
as spontaneously forming by the
laws of physics and chemistry.
And some of the examples
that Caleb was citing I
think would fit in that kind
of definition, that you just
wouldn't expect naturally
like energy to behave this way.
>> Susan Schneider: You
wouldn't expect a Dyson sphere.
>> Sara Imari Walker:
Not exactly.
So, the question is, how
do we formalize that?
Because Dyson spheres
are obviously things
that we've imagined.
But like what about all the
things we haven't imagined?
And so I think, I
think that that's sort
of the real challenge
that we need to face
with technosignatures.
And one of the places I think
about that is actually to think
about molecules as biosignatures
or technosignatures.
So, one thing is like
there are some, you know,
some things that the
universe just can't produce,
even in terms of chemistry,
and it might require getting
all the way to technology.
And so how many steps is it
to actually produce that kind
of molecule or that kind
of object in the universe?
And could you say that that
could happen in a finite number
of steps by chemistry, or
it requires some system
that actually knows
how to build that?
Like it has the algorithm
for assembling that object.
And so that's sort of one
approach that you can take based
on this information
all perspective,
to try to do this
more agnostically.
But it's a huge challenge.
>> Caleb Scharf: Actually,
if I might just jump in.
The thought came to me, which
sort of relates to the questions
of machine learning and
artificial intelligence,
you know, I think both of
us have been saying it,
one of the problems
is, you know,
not knowing what we don't know,
and how do you recognize stuff
that's completely outside
of our experience, and isn't
even a simple extrapolation
from our own technology.
Well, you know, at some
point, we might have machines,
machine learning that it may not
be super intelligent or anything
as dramatic as that, but
it could, in principle,
examine the universe
around us in a way
that has fewer preconceived
notions
about what it's looking for.
You know? You basically have it
program itself on what it sees
and try to make sense
of what's out there.
Conceivably then, it's not a
human mind that will succeed
in finding something truly
unexpected out there.
It might be something
like a machine that has
so potentially fewer
preconceptions
about what it's looking for.
>> Susan Schneider:
That's fascinating.
What about microbial life?
I mean, you know, if
you were to guess,
like what would we find
first, if anything,
in the search for life?
You probably wouldn't say that
it would be intelligent life.
Am I right?
>> Sara Imari Walker: I
would say not necessarily.
I think, you know, a lot
of people want to argue
that you're going to find
microbial life first,
but I think it's
a, it's a question
of like how abundant
is technological
versus microbial life,
and how hard are the steps
to get both of them?
So, there's this kind of issue
that we don't know
the likelihood
of the origin of life happening.
And we also don't
know the likelihood
that once you get an origin
or life event, say that origin
of life is always
biological, that you're going
to get intelligence evolving.
So, those are two
hard steps associated
with these two different kinds
of life that we want to look at.
Right? But then the other
sort of flip side of it is
which is going to be more
readily recognizable,
or which is going to
be more widespread?
And so there's sort
of this assumption
that says microbial life comes
before technological life,
which would be more widespread.
And, therefore, we could be
able to find it more readily.
But it might be the case
that once you have, you know,
say one intelligence
transitioned
to technological life, it
is so super intelligent
that it readily spreads
in the universe,
and its observational signatures
are still more readily apparent
to us, that it's
actually an easier target,
even though it's a
much rarer event.
So, I think you have
to always weigh sort
of like what's the
likelihood of detection
versus what's the likelihood
of this thing existing
in the universe.
And I think, I think the
jury's out on that one.
But I'm interested in looking
at the past society too.
>> Caleb Scharf: Yeah, no,
I actually agree
with that, I think.
You know, we have this sense
that microbial life
[inaudible] in the universe.
And, you know, that may be true.
But our identification of life
as an unambiguous identification
of life may be much harder for
something like microbial life.
And we actually are
facing this challenge
in exoplanetary science.
People are looking at
potential chemical signatures
in the atmosphere of exoplanets.
You know, it's a fingerprint of
the existence of a biosphere.
But the truth is, even if we
find evidence of, you know,
oxygen and methane and sulfate
compounds, will we ever be able
to convince ourselves 100%
that what we're seeing is life?
Whereas if you, if you,
you know, talk to an alien,
you're pretty sure
that's an alien.
And so in that sense,
yeah, as Sara said,
it's this fascinating sort of
these overlapping functions,
there may be lots of more,
lot of microbial life.
But it just actually, in
my opinion, may be harder
to convince ourselves that
we've really found it anywhere.
Whereas a talking, walking alien
is a whole different story.
>> Susan Schneider:
That's fascinating.
I mean, you know, I thought
about Robin Hanson's
Great Filter argument.
And, you know, we certainly
don't know at any point
of the filter, you know,
where it's going to be really,
really difficult for
life to continue.
I mean, it could be
that microbial life
itself is fairly rare.
Or it could be
that technological civilizations
have all sorts of catastrophes.
You know, we just don't know.
And, you know, it could be
that we don't even
know what we're looking
for when we're looking for life,
because we have a very small
and approach based on one
case, the case we know of,
but there's a sort of universal
code, if you will, you know,
some sort of way of
civilizations to communicate
that happens when civilizations
hit a certain level
of intelligence.
And, of course, that's highly
speculative, but, I mean,
I think it's definitely
possible,
if you ask me as a philosopher.
Now, what I'd like to do
next is I want to kind
of get perhaps a little
bit even more speculative.
So, to go back to, you know,
Sara's initial discussion
of what life is, you know,
Sara, you have a sort
of information based focus on
life that's really fascinating,
because it's easy to connect
your approach to life to your,
you know, theories of
intelligence, for example.
And so what I'm wondering,
Caleb and Sara, you know,
because I know, I've known Caleb
for years, and we've talked
about consciousness at
the institute many times.
I'm wondering, you know, clearly
all forms of life aren't equal
from a moral standpoint.
You know, one thing
interesting about the evolution
of intelligence, at least
in biological systems,
is that the most sophisticated
biological systems are
also conscious.
It feels like something
from the inside to be there.
But that may just be a kind
of rule with biological cases,
or at least cases on Earth.
And, you know, if civilizations
do become post biological,
they will no longer
be biologically based.
And it makes me wonder if
intelligence, as it evolves,
even has conscious experience.
So, I'm wondering, I'm just
trying to get the reaction,
reaction to that
from both of you.
>> Caleb Scharf: I'm going
to let Sara go first.
>> Sara Imari Walker: Yeah,
oh, I understand [inaudible].
I work on consciousness too.
But I think, I think the issue
is, so, people always want
to focus on this notion
of the subjective
aspects of consciousness.
But I think the issues continue
to formulate physical
theories is does it matter
if like the reality
external to something,
if that thing is
conscious or not?
And so from the sort
of informational
processing perspective,
I think there is something
that consciousness gives
to the dynamics of
physical systems that other
like nonconsciousness can't do,
which is to like have
imagination and realize things
that haven't existed, and
then actually perform the kind
of algorithms in the
physical universe
to make those things real.
So, one example is just, you
know, humanity as a whole
like imagined things
like rockets
and planes long before
we ever built them.
But those are real physical
consequences of the fact
that we have internal
representation in our minds.
So, my personal perspective
on it is
that consciousness is a
manifestation of the physics
of life, which is the physics
of how information operates
in the physical world.
And that other intelligences
and things will have to abide
by the same kind of
physical principle.
So, you might get some
odd quasi intelligent,
quasi lifelike things that don't
have internal representation,
but they would probably be, like
if you're thinking about life
and intelligence on a spectrum,
kind of like low
level intelligences
or low level information
processing systems.
And that most of them,
especially if they were going
to be an open ended evolutionary
process, would require something
that we would associate with
consciousness, and the fact
that they can internally
represent abstractions
and then use those to do things.
Yeah, so that's my
two second theory
of [inaudible] in the universe.
>> Caleb Scharf: I
can't compete with that.
Yeah, I think it's, you know,
it's an interesting question
of where you place I think
consciousness in the pantheon
of things, I like Sara,
probably like myself, you know,
with physics background, one
sees it as a potential solution
to certain environmental
pressures.
It opens up niches
for, you know,
for life forms to expand into.
What's interesting to me is
evolution on Earth, you know,
does as well as it needs
to in any given moment.
Right? Species don't,
aren't evolving
to some predetermined
perfection.
If it works, great,
because it often costs more
to develop greater complexities.
It has to be really a good
reason for doing that.
I wonder in the universe
at large whether, you know,
consciousness is ubiquitous, or
it's just one of those things
that happens in certain
niches where it gives
that extra little advantage,
enhances propagation
odds into the future.
So, you know, there
could be a lot
of what I call savant entities,
especially post biological
savants that are really good
at replicating and spreading
between the stars, for example.
But that is about it.
They're not necessarily
conscious unless
that provides them some
additional advantage.
Maybe it doesn't.
Maybe the ability to imagine
and to recognize your observing
from within doesn't
always help you that much.
You know? Maybe big data
crunching savants are actually
the things that rule
the universe.
>> Sara Imari Walker:
Well, I, you know,
I just have one comment on
that, which I think it's kind
of an interesting thing,
because I always wonder
about whether the fact that we
have internal representation is
necessary to doing science in
the first place or physics.
So, would they even be able
to write down like the laws
of motion, which is an
abstraction, or do mathematics
if they didn't have
internal representation.
>> Caleb Scharf: Yeah,
I think that's a really
fascinating question.
>> Sara Imari Walker: Yeah.
>> Caleb Scharf: Yeah, because
it also, you know, there's laws,
right, essentially derive
from imperfect measurements
of the world, and
somehow, there's something
about our imagination, our
internal representation
that lets us overlook
all the floors.
>> Susan Schneider: And I
chime in as a philosopher,
even though I'm just
the question
and answer person today.
>> Sara Imari Walker:
Of course, of course.
>> Susan Schneider: So, I think
that computers have
internal representations.
And so I think if there
are savant systems
or super intelligent computers,
they will have representations,
but that's a different
issue than consciousness.
At least for most philosophers.
So, consciousness is that felt
quality of experience, like,
you know, when you sort of
warm up your morning coffee
when you stub your toe, it
feels like something to be you.
Internal representations,
they're easier
to achieve, if you will.
But, of course, there are some
philosophers, like John Searle,
who would disagree with what
I just said, because he felt
that consciousness was required
for a system to understand
or represent the world.
But that is, I think
it is a minority you.
Right. So, I guess for me,
there's a real question there
about will sophisticated super
intelligent AIs, you know,
whether they be here on Earth
or elsewhere in the universe,
would it feel like
anything to be them?
Because I do think,
contra, Sara, you know,
that we can already see all
around us sophisticated
computation that's not
conscious computation.
So, a great example is that
most of what the brain is doing
at any given moment
computationally, like in terms
of its information processing,
is actually not conscious,
sadly.
But you wouldn't want
all that minutia.
You know? Although it would be,
it would be better for science
if we could introspect how
the visual system works,
for example, and, you know,
all the little algorithms.
But, I mean, our
brains are amazing.
But all that computation,
I mean, only a smidgen
of it is even accessible
to consciousness.
So, that's an example
right there.
You know? And AI, you know,
it's not going to evolve
in accordance with
Darwinian evolution.
There will be evolutionary
constraints,
but they won't be Darwinian.
>> Sara Imari Walker: Yeah,
I don't think I was necessarily
taking a Darwinian perspective
on it.
But I think there's
also this issue
that we confuse computation with
like what happens in physics.
So, computation is
an abstraction
that we use to describe systems.
It's not necessarily what the
system is physically doing.
And I think there's a, like,
and this is part of the problem
with consciousness
also, we think about it
as an abstraction,
and we don't know how
to think about it physically.
And so I think all of these
things are just really,
they seem mysterious because
we have ways of talking
about the world that are
not necessarily the world.
And we haven't really
come up with ways of sort
of merging those narratives
in a convincing way
where it's really the physical
system doing the information
processing, and it's not just
like a slapped on description.
And I think those things
are fundamentally different.
It has something to do
with like the difference
between like Turing's
abstraction notion
of computation and Von Neumann's
idea of universal construction,
which was trying to embed that
abstraction in a physical way.
But he didn't actually get
even far enough to connect
that with physics proper.
So, I think we're a long way
off from actually answering any
of the questions that you
were talking about, Susan.
But I think you raise a
lot of really good points.
But I think that feeling
that you have is a
real physical feeling.
It means you exist and
you're not a simulation.
So, it doesn't mean that other
things, like simulations,
can't physically exist, because
I think you're a physically
instantiated simulation, and
that's why you feel that way.
>> Susan Schneider: That
is mind blowing, isn't it?
And it's just too bad
we're not around each other
to actually hash this
out further [inaudible]
because we've had
fun in the past.
Right. Now, our audience
will probably want
to know a little more about
the Great Filter idea,
because they're probably
trying to figure out, you know,
this idea about at what
point it could be difficult
for there, for life to emerge.
And so I'm wondering if either
of you could talk a little bit
about the Great Filter argument.
Maybe Caleb, since, you
know, we haven't given you
as much time [inaudible].
>> Caleb Scharf: I'm
not sure about that.
I've probably had
more than my share.
Yes, well, the Great
Filter is very interesting.
And I guess there are a number
of ways of describing it.
But the way I tend to think
about it is in the context
of this thing called the
Fermi paradox, which is,
goes back to the physicist
Enrico Fermi, back at the dawn
of the space age,
who essentially just made the
observation that, in principle,
if you have anywhere in our
galaxy a species emerge any time
over the last 13 billion
years, that has the capacity
and interest in moving between
the stars, then it's had plenty
of time to get everywhere
by now.
You know, even moving
slowly between the stars.
And so the question is
then where is everyone?
>> Sara Imari Walker:
Hiding from us?
>> Caleb Scharf: Well, yeah.
So, you know, there are many
potential solutions to this.
So, the premises is that we have
no real evidence of, you know,
other life or having
been visited.
I mean, I know it depends
on who you talk to,
but I think most rational
people would say there's no
direct evidence.
And so there is this paradox
is a little bit strong,
but there's a puzzle.
Right? Because it's
either telling us
that life is incredibly rare,
and the technological life is
so extremely rare that it
actually hasn't happened
yet in our galaxy, or there's
something that prohibits it.
And related to that is
the Great Filter idea,
the idea that at some point
any sufficiently sophisticated
species that spreads across
its planet, much like us,
hits a wall, that there's
something that just prevents it
from becoming a true
interstellar species.
And you can you know,
there's a checklist
of things you could add to that.
And an interesting sort of
slant on that argument is
that then it actually would
be incredibly depressing
to find evidence of
life say on Mars.
And the idea is that suppose you
find evidence of life on Mars
that has a completely
independent origin from us,
it doesn't matter if it's
still alive or if it was there
in the past, that
increases the likelihood
of life having happened all over
the place around our galaxy,
which then says that it should
have definitely been the case
that somewhere in the
last 13 billion years,
there would have been
another species capable
of interstellar transport
and going everywhere.
It reinforces the notion
that there's a great filter,
and that we are on
the wrong side of it.
Because it's something that
just prevents true interstellar
spread from any, any species.
That's basically
the Great Filter.
>> Susan Schneider: Oh, boy.
It's always good to think
about this during a pandemic
too, don't you think?
>> Caleb Scharf: Yeah,
well, it adds another box
to that checklist of
possible, possible [inaudible].
>> Susan Schneider: Yeah, yeah.
But it is a fascinating idea.
So, perhaps one way to
conclude then is I want to know
if you had to place
your bets on how
to solve the Fermi
paradox, what would you say?
>> Caleb Scharf: Well, I've
actually done work on this.
And one, one, some colleagues
and I have done simulations
of the spread of
interstellar species.
And one possibility is
actually kind of simple,
that it's just we haven't,
that they're out there,
but they're kind of clustered.
We call it an Archipelago model
that based on our knowledge
of astrophysics and the
way stars are distributed
in our galaxy and they
move around the galaxy,
there are going to be regions of
our galaxy just better for this,
better for interstellar
civilizations to spring up.
And we're probably not
in one of those regions.
So, that's the sort of, that's a
weaselly way out of it by saying
>> Susan Schneider: Could
you elaborate why aren't we
in one region?
>> Caleb Scharf: Well, that
would be the speculation
that we're not in one of
those regions, so that's,
perhaps a little more sparse,
the motion of the stars makes
it less likely for transition
from star to star
to star and so on.
And part of the basis for that,
you can actually say, well,
there's no real evidence that
anytime within the last 1
to 10 million years that Earth
has been visited, shall we say,
by technological species.
Beyond that, it's
actually very hard to say.
You can actually, by looking at
paleontological data, it's very,
very difficult to note
what was going on.
But that 1 to 10 million year
window definitely places us
in one of these sparse regions
if this picture were
to be correct.
But it also says that we
now know where to look
in the rest of the galaxy.
So, that's kind of the,
you know, [inaudible].
>> Susan Schneider: Oh, wow.
And we could shoot with the,
back to Project Starshot,
which we were both,
we had a [inaudible].
>> Caleb Scharf: Yeah, I mean,
more in terms of, you know,
picking up our telescopes
and our
>> Susan Schneider: Sara,
what would your answer
to the Fermi paradox be?
>> Sara Imari Walker:
So, mine is like the sort
of really trivial one that
we don't know what we're
looking for.
But I mean that in
kind of a deep sense,
like in the sense like, you
know, humans have been looking
at the night sky for thousands
and thousands of years
and we never noticed
gravitational waves,
for example.
But it required some really
deep insights into the nature
of the universe in order
to even start looking
for gravitational waves,
and then eventually
to just discover them.
And I think we are just so
primitive in our ability
to theorize and think about
life that we're in sort
of like pre general
activity physics with respect
to finding something
like gravitational waves,
with respect to finding
life and intelligence.
So, obviously, I would say
that as a theorist that wants,
you know, people to invest
in theories for what life is.
But I think, I think it really,
we need better frameworks
for guiding research, and that's
not a it sounds look a trivial
thing, but it's not
really a trivial thing.
Like it's really
necessary in order for us
to detect life, in my view.
>> Susan Schneider: Fascinating.
And, you know, in a way,
both of you could be right,
because there could be clusters,
and we just don't have an idea
of what those technosignatures
would be,
because we need a certain
paradigm shift or we need
to enhance our own intelligence
so that we can even
think along the lines
of a highly advanced
civilization, although,
you know, to go back to
Caleb's point earlier, I mean,
there do seem to be some hard
constraints on computation,
you know, with heat, for
example, and it seems like even
in our humble predicament,
these are the kinds
of constraints which
seem very real.
>> Sara Imari Walker: Right.
And you can always argue
that they go to doing some
like quantum computation and
like deep interstellar space
where it's nice and cold,
and then they just [inaudible]
radiation or something with sort
of the long term fate of
post biological evolution.
So, I think it's like
any argument you give,
you can get around in some way.
But, yeah, it's a hard problem.
>> Susan Schneider: Well,
the debates continue.
And today just gave the
listeners, you know,
a small chunk of the kind of
debates we have when we talk
about the future of life and
intelligence and consciousness.
And I just want to
thank you very much
for talking with me today.
It was wonderful to have you.
>> Sara Imari Walker: Thank you.