Kind: captions
Language: en
the following is a conversation with
sarah walker a nestor biologist and
theoretical physicist at arizona state
university and the santa fe institute
she's interested in the origin of life
how to find life on other worlds and in
general the more fundamental question of
what even life is
she seeks to discover the universal laws
that describe living systems on earth
and elsewhere using physics biology and
computation
quick mention of our sponsors athletic
greens netsuite blinkist and magic spoon
check them out in the description to
support this podcast as a side note let
me say that my hope for this podcast is
to try and alternate between technical
and non-technical discussions to jump
from the big picture down to specific
detailed research and back to the big
picture and to do so with scientists and
non-scientists
long term i hope to alternate between
discussions of cutting-edge research in
ai physics biology
to topics of music sport and history and
then back to ai
ai is home
i hope you come along with me for that
wild oscillating journey
some people message me saying to slow
down since they're falling behind on the
episodes of this podcast
to their disappointment i have to say
that i'll probably do more episodes not
less
but you really don't need to listen to
every episode just listen to the ones
that spark your curiosity think about it
like a party full of strangers you don't
have to talk to everyone
just walk over to the ones who look
interesting and get to know them
and if you're lucky that one
conversation with a stranger might
change the direction of your life
and it's a short life so be picky with
the strangers you talk to at this
metaphorical party
this is the lex friedman podcast and
here is my conversation with sarah
walker
how did life originate on earth what are
the various hypotheses for how life
originated on earth yeah so
i guess you're asking a historical
question which is always a good place to
start thinking about life um
so there's a lot of ideas about how life
started on earth um probably the most
popular is what's called the rna world
scenario um so this idea is probably the
one that you'll see most reported in the
news
and is based on the idea that there are
um
molecules in our bodies um that uh relay
genetic information and we know those as
dna obviously but there's also sort of
an intermediary called rna ribonucleic
acid
that also plays the role of proteins
and
people came up with this idea in the 80s
that maybe that was the first genetic
material because it could play both
roles of being genetic and performing
catalysis and then somehow that idea got
reduced to this idea that there was a
molecule that emerged on early earth and
underwent darwinian evolution and that
was the start of life
so there's a lot of assumptions
packed in there that we could unpack but
that's sort of the leading hypothesis
there's also other ideas about life
starting as metabolism and so that's
more connected to the geochemistry of
early earth
and it would be kind of more focused on
this idea that you get some kind of
catalytic cycle of molecules that can
reproduce themselves and form some kind
of metabolism and then life starts
basically as self-organization and then
you have to explain how evolution comes
later
right so that's the difference between
sort of uh energy and genetic code so
like energy and information are those
are the two kind of yeah
yeah i think that's a good way of
putting that it's um
it's kind of funny because i think most
of the people that think about these
things are really disciplinary bias so
the people that tend to think about
genetics come from a biology background
and they're really evolution focused and
so they're worried about where does the
information come from and how does it
change over time but they're talking
about information in a really narrow way
where they're talking about a genetic
sequence and then most of people that
think about
metabolism origins of life scenarios
tend to be people like physicists or
geochemists that are worried about what
are the energy sources and what you know
like what kinds of organization can you
get out of those energy sources okay so
which one is your favorite i don't like
either
okay all right can we talk about them
for a little bit longer though
uh so okay so there's uh early earth
what was that like was there just mostly
covered by oceans was there heat sources
energy sources so if we
uh talk about the metabolism view of the
origin of life like where was the source
of energy probably the most popular view
for where the original life happened on
earth is hydrothermal vents because they
had sufficient energy
and so we don't really know a lot about
early earth
we have you know some ideas about when
oceans first formed and things like that
but the time of the original life is
kind of
um not well understood or pinned down
and the conditions on earth at that time
are not well known
but a lot of people do think that there
was probably hydrothermal vents which
are really hot
chemically active regions say on the sea
floor in modern times which also would
have been present on early earth and
they would have provided energy and
organics
and basically all of the right
conditions for
the origins of life which is one of the
reasons that we look for these
hydrothermal systems when we're talking
about life elsewhere too
okay and for the genetic code
the idea is that the rna is the first
like why would rna
be the first moment you can say it's
life
i guess the idea is it could both
have persistent information
and then it can also do some of the work
of like what creating a self-sustaining
organism
yeah that's the basic idea so the idea
is you have in an rna molecule you have
a sequence of characters say so you can
treat it like a string in a computer
and it can be copied so information can
be propagated
which is important for
evolution because evolution happens by
having inheritance of information so for
example you know like my eyes are brown
because my mother's eyes were brown
so you need that copying of information
but then
you
also have the ability to perform
catalysis which means that that rna
molecule is not inert in that
environment but it actually interacts
with something that could potentially
mediate say a metabolism that could then
fuel
the actual reproduction of that molecule
so
in some ways
people think that rna gives you
you know
the most bang for your buck in a single
molecule and therefore
you know it gives you all the features
that you might think are life um
and so that this is sort of where this
rna world conjecture came from is
because of those two properties
isn't it amazing that rna came to be
in general isn't it yes that is amazing
okay so we're not talking down about rna
no no i love rna it's one of my favorite
molecules i think it's beautiful it's
just not step one
yeah i think i think the issue it's not
even the rna world is a problem and
actually if you really um dig into it
the rna world is not one hypothesis it
is a set of hypothesis
hypotheses sorry and they range from
a
molecule of rna spontaneously emerged on
the early earth and started evolving
which is kind of like the hardest rna
world scenario which is the one i cited
and i get a little um
uh animated about because it seems so
blatantly wrong to me but that's a
separate story and then the other one is
actually something i agree with which is
that
you can say there was an rna world
because rna was the first genetic
material for life on earth so an rna
world could just be
the earliest organisms that had
genetics in a modern sense didn't have
dna evolved yet they had rna
right and so that's sort of a softer rna
world scenario in the sense that it
doesn't mean it was the first thing that
happened
but it was a thing that definitely
was part of the lineage of events that
led to us
so if life was a
like a best of album it would be on the
maybe one of the songs on there yes one
of the early songs okay it's on the
greatest hits greatest hits that's the
word i was looking for okay did life do
you think originate once
twice three times on earth multiple
times what do you think i think that's a
really difficult question um and an
important question it's a super
important question no that no it's a
really important question um and so
there there's some so there's
there's a lot of questions in that
question um so one of the first ones
that i think needs to be addressed is is
the original life a continuous process
on our planet so
we think about the original life is
something that happened on earth um say
almost four billion years ago because we
have evidence of life emerging very
early on our planet
um
and then an original life event quote
unquote a singular event whatever that
was happened and then all life on earth
that we know
is a descendant of that particular event
in our universe right and so
um but
uh we don't have um
any idea one way or the other if the
original life is happening repeatedly
and maybe it's just not taking off
because life is already established
that's a argument that people will make
or
maybe there are alternative forms of
life on earth that we don't even
recognize
um so this is the idea of a shadow
biosphere that there actually might just
be completely other life on earth but
it's so alien that we don't even know
what it is
i'm gonna have to talk to you about the
shadow biosphere
in a second but first let me ask for the
other alternative which is panspermia
right so that's the idea the hypothesis
that life exists elsewhere in the
universe and got to us through like an
asteroid
or a planetoid or some
uh according to wikipedia space dust
whatever the heck that is
uh it sounds fun but basically rode
along
yeah whatever
kind of rock and got to us
do you think that's at all a possibility
sure so i think the reason that most
original life scientists are interested
in the origin of life on earth and say
not the original life
um
you know on mars and then panspermia you
know the exchange of life between
planets being the explanation is once
you start removing the original life
from earth you know even less about it
than you do if you study it on earth
although i think there are ways of
reformulating the problem this is why i
said earlier like oh you mean the
historical original life problem you
don't mean the problem of how does life
arise in the universe and what the
universal principles are because there's
this historic problem how did it happen
on early earth and there's a more
tractable general problem of how does it
happen
and how does it happen is something we
can actually ask in the lab how does it
how did it how did it happen on early
earth is
a much more detailed and nuanced
question and requires detailed knowledge
of what was happening on early earth
that we don't have
and i'm personally more interested in
general mechanisms so to me it doesn't
matter if it happened on earth or it
happened on mars
it just matters that it happened we have
evidence that happened
the question is did it happen more than
once in our universe and so the reason i
don't find panspermia as a particularly
i think it's a fascinating um hypothesis
i definitely think it's possible um and
um
and i in particular i think it's
possible once you get to the stage of a
life where you have technology because
then you you obviously can spread out
into the cosmos um but it's also
possible for microbes because we know
that um certain microorganisms can
survive the journey in space and we you
know they can live in a rock and go
between mars and earth like people have
done experiments to try to prove that
could work um so in that scenario it's
super cool because then you get
planetary exchange but say we go find we
go look for life on mars and it ends up
being exactly the same life we have on
earth biochemically speaking then we
haven't really discovered something new
about the universe what kind of aliens
are possible were there other original
life events if we find if all the life
we ever find is the same original life
event in the universe it doesn't help me
solve my problem but it's possible that
that would be a sign that you could
separate the environment from the
basic ingredients yes so that's true you
can have like a life gun
that you shoot throughout the universe
and then uh
like once you shoot it it's like the
simpsons with a makeup gun that was a
great episode uh when you shoot this
life gun
it'll he'll find the earth's it'll like
get sticky it'll stick to the earth's
and that kind of reduces the barrier of
uh
like the time it takes the the luck it
takes to actually from nothing from the
basic chemistry from the basic physics
the universe for the life to spring up
yeah i think this is actually super
important to just think about like does
life
getting seated on a planet have to be
geochemically compatible with that
planet so you're suggesting like we
could just shoot guns in space and like
life could go to mars and then it would
just live there and be happy there um
but that's actually an open question so
one of the things i was going to say in
response to your question about
whether the original life happened once
or multiple times is for me personally
right now in my thinking although this
changes on a weekly basis but um is that
i think of life more as a planetary
phenomena so i think the original life
because um because life is so
um intimately tied to planetary cycles
and planetary processes and this goes
all the way back through the history of
our planet that the original life itself
grew out of geochemistry and became
coupled and controlled geochemistry and
and when we start to talk about life
existing on the planet is when we have
evidence of life
actually influencing properties of the
planet um and so
so if life is a planetary property um
then going to mars is not a trivial
thing because you basically have to make
ours
mars more earth-like um and so in some
sense um like when i think about sort of
long-term vision of humans in space for
example
really what you're talking about when
you're saying let's send our
civilization to mars is you're not
saying let's send our civilization to
mars you're saying let's reproduce our
planet on mars like the information from
our planet actually has to go to mars
and make mars more earth-like which
means that you're now having a
reproduction process like a cell
reproduces itself to propagate
information in the future
planets have to figure out how to
reproduce their conditions including
geochemical conditions on other planets
in order to actually reproduce life in
the universe which is kind of a little
bit radical but i think
for long-term sustainability of life on
a planet that's absolutely essential
okay so
if we were to think about life as a
planetary phenomenon
and so life on mars would be best if
it's way different than life on earth
we have to ask the very basic question
of
what
is life
i actually don't think that's the right
question to ask
it took me a long time to get there
right so cross it out yeah you cross it
off your list it's wrong
no question um no no no i mean i think
it has an answer but i think the part of
the problem is um you know most of the
places in science where we get really
stuck is because we don't know what
questions to ask um and so you can't
answer a question if you're asking the
wrong question um and i think uh the way
i think about it is obviously i'm
interested in what life is so i'm being
a little cheeky when i say that's the
wrong question to ask that's exactly
like the question that's like the core
of my existence but
um
but i think the way of framing that is
what is it about our universe that
allows features that we associate life
to be there um and so really what i
guess when i'm asking that question what
i'm after is an explanatory framework
for what life is right and so most
people they try to go in and define life
and they say well life is uh say a
self-reproducing chemical system capable
of darwinian evolution that's a very
popular definition for life um or life
is something that metabolizes and eats
that is not how i think about life what
i think about life is there are
principles and laws that govern our
universe
that we don't understand yet
that have something to do with
how information interacts with the
physical world i don't know exactly what
i mean even when i say that um because
we don't know these rules um but it's a
little bit like um i like to use
analogies you'll give me time to be like
a little long-winded for a second even
in as i um but um but sort of like if
you look at the history of physics for
example this is like so we are in the
period of the development of
thought on our planet where we don't
understand what we are yet right um
there was a period of thought in the
history of our planet where we didn't
understand what gravity was
um and we didn't understand for example
that planets in the heavens
you know were actually planets or that
they operated by the same laws that we
did
um and so there has been this sort of
progression of getting a deeper
understanding of explaining basic
phenomena like i'm not gonna drop the
cup i'll drop the water bottle there you
go okay that fell right but why did that
fall um
this is why i'm a theorist not an
experiment
i could have gone wrong in so many ways
i know i could have especially if i did
the confidence smash anyway
um so um so if you think you take this
view that there's sort of some missing
principles i associate them uh to
information and what it what the sort of
feeling there is there's some missing
explanatory framework for how our
universe works and if we understood that
physics it would explain what we are um
it might also explain a lot of other
features we don't associate to life um
and so it's a little like um people
accept the fact that gravity is a
universal phenomena but when we want to
study gravity we study things like large
scale
you know galactic structures or black
holes or planets
if we want to understand information and
how it operates in the physical world we
study intelligent systems or living
systems because they are the
manifestation of that physics
and the fact that we can't see that
clearly yet or we don't have that
explanatory framework i think it's just
because we haven't been thinking about
the problem deeply enough but i feel
like if you're explaining something
you're deriving it from some more
fundamental property and of course
um i have to say i'm wearing my my
physicist hat so i have a huge bias of
liking
simple elegant explanations of the
universe that
um
you know really are compelling but i
think one of the things that i've sort
of
maybe in some ways rejected my training
as a physicist is that most of the
elegant explanations that we have so far
don't include us in the universe and i
can't help but think there's something
really special about what we are and
there have to be some deep principles at
play there
um
and so so that's sort of my perspective
on it now when you ask me what life is i
have some ideas of what i think it is
but i think that we haven't
gotten there yet because we haven't been
able to see that structure and it's and
just go back to the gravity example it's
a little like you know in ancient times
they didn't know i was talking about
stars and heavens and things they didn't
know those were um you know governed by
the same principles as that starting to
experiment here's where i was going with
it once you realize like newton did that
you know heavenly emotions and earthly
emotions are governed by the same
principles and you unify terrestrial and
celestial motion you get these more
powerful ideas
um and i i think where life is is
somehow unifying these abstract ideas of
computation and information
with the physical world with matter and
realizing that there's some explanatory
framework that's not physics and it's
not computation but it's something
that's deeper
so
answering the question of what is life
requires
deeply understanding something about the
universe as information processing
universe is computation
something about
like would uh once you come up with an
answer to what is life well the words
information and computation be in the
paragraph no i don't think so oh damn it
okay i know it doesn't help does it i
know i i hate actually i hate this about
what i do because it's so hard to
communicate right with words like when
you have words that are
um ideas that have historically
described one thing and you're trying to
describe something people haven't seen
yet right and the words just don't fit
so what uh what's wrong is it too
ambiguous the word information we could
switch to binary if you want yeah no i
don't think it's binary either i think
information is just loaded i use it so
the other way i might talk about it is
the physics of causation but i think
that's worse because causation is even
more loaded word than
um
information causation is fundamental you
think i do yeah and um in some sense i
think the physics so this is the really
radical part some sense like when i
really think about it sort of most
deeply uh what i think life is is
actually the physics of existence what
gets to exist and why um and you know
for simple elementary particles that's
not very complicated because the
interactions are simple but for things
like um you know you and me and human
civilizations
um you know what comes next in the
universe is really dependent on what
came before and there's a huge space of
possibilities of things that can exist
and when i say information and causation
what i mean is why is it that
cups evolved in the universe and not
some other object that could deliver
water and not spill it
i don't know what you would call it uh
maybe it wouldn't be a cup but um but
it's a huge it it's um
you know you know people talk about the
space of things that could exist as
being actually infinitely large right i
don't know if i believe in infinity
um but i do think that
there is something very interesting
about
the problem of what exists in its
relationship to life so do you think
this
the set of things that could exist is
finite
it's very large but like if we were to
think
about the physics of existence
like how how many shapes of mugs can
there be like is uh
in the initial programming i should go
to the math department for that but
so that's not a topology question i just
mean
maybe another way to ask is what do you
think is fundamental to the universe and
what is emergent so if existence i was
supposed to think of that as somehow
fundamental you think so there's a
couple problems in physics that i think
this is related to one is why does
mathematics work at describing reality
so well
um and then there is this problem of we
don't understand why the laws of physics
are the way they are or why certain
things get to exist or
what put in place the initial condition
of our universe right there's all of
these sort of really deep and big
problems and they they all um
indirectly are related i think to the
same kind of thing that um
you know our physics is really good if
you specify the initial condition at
specifying a certain sequence of events
but it doesn't deal with the fact that
other things could have happened which
is kind of an informational property
like a counter factual property
um
and it's not good at explaining
uh
you know this conversation right now
it's just it there are certain things
that are outside the explanatory reach
of current physics and
um i think they require looking at it
from a completely different direction
um and so i don't want to have to
fine-tune the initial condition of the
universe to specify precisely all the
information in this conversation i think
that's a ridiculous assertion um but
that's sort of like how people want to
frame it when they talk about
um
you know the standard model is
sufficient if we had computing power to
basically explain all life in our
existence an interesting thing you said
is the way we think about information
computation is by observing a particular
kind of systems on earth
that exhibit something we think of as
intelligence but that's
that's like uh looking at i guess the
tip of an iceberg and we should be
really looking at the fundamentals of
like the iceberg like like like what
makes
water and ice and and and the chemistry
that from which intelligence emerges
essentially
we can't just couple the information
from the physics and i think that's what
we've gotten really good at doing
especially with
sort of
the modern age where you know software
is so abstracted
um from
hardware
but the entire process of biological
evolution has basically been built like
been building layers of increasing
abstraction and so it's really hard to
see that physics in us but it's much
clearer to see it in molecules
yeah but i guess i'm trying to figure
out what what do you think are the best
tools to look at it
what do you think
an open mind is that a tool
what's the physics of an open mind
i think if we saw that we'll solve
everything i'm saying an open mind
because i think the biggest stumbling
block um
to understanding sort of the things i've
been trying to articulate or and when i
talk also with colleagues that are
thinking deeply about these same issues
is
none of it is inconsistent with what we
know it's just such a radically
different perception perception of the
way we understand things now that it's
hard for people to get there and in some
ways you have to almost forget what
you've learned in order to learn
something new right so i feel like most
of my career trying to understand the
problem of life has been variously
forgetting and then relearning things
that i learned in physics and and i
think you have to
you have to have a capacity
to learn things but then accept that
things that you were you you learned
might not be true
um
or
or might need refinement or reframing
um
and the best way i can say that is just
like with a physics education there are
just certain things you're told in
undergrad that are like facts about the
world
and your physics professors never tell
you that those facts actually emerge
from a human mind right so we're taught
to think about say the laws of physics
for example
as this like
autonomous thing that exists outside of
our universe and tells our universe how
it works yeah um but the laws of physics
were invented by human minds to describe
things that are regularities in our
everyday experience
right they don't exist autonomous to the
universe right so it's like turtles on
top of turtles but
eventually gets the human mind and then
you have to explain the human mind with
the turtles yes so you have to yeah it
comes from humans this understanding the
simplification of the universe these
models yeah there's a guy named stephen
wolfram there's a
concept called cellular automata so
there's a
there's some mysteries in these um
systems that are computational in nature
that have
maybe echoes
of the kind of mysteries we should
need to solve to understand what is life
[Music]
so
if we could talk take a
computational view of things do you
think there's something compelling to
reducing everything down to computation
like the universe is computation and
then trying to understand
life so
throw away the biology throw away the
chemistry throw away even the physics
that you you learn undergrad in graduate
school and more look at these simple
little systems whether it's cellular
automata or whatever the heck kind of
computational systems that operate on
simple local rules and then create
complexity
as they evolve
is is it uh at all do you think
productive to focus on those kinds of
systems to get an inkling of what is
life
and if it is
do you do you think it's
it's possible to come up with some kind
of laws and principles about what makes
life in those computational
systems
so i like cellular automata i think
they're good toy models um but mostly
like where i've thought about them and
use them is to actually
um
[Music]
let's say poke at sort of the current
conceptual framework that we have and
see where the flaws are
um so i think like the part that you're
talking about that people find
intriguing is that if you have like a
fairly simple rule
and you specify some initial condition
and you run that rule and that initial
condition you could get really complex
patterns emerging and ooh doesn't that
look lifelike um
yeah
well it's like really surprising isn't
it it is really surprising and they're
beautiful um and i i think they have a
lot of nice features associated to them
um i think the things that i find yeah
so so i i do think um as a proof of
principle that you can get complex
things emerging from simple rules
they're great
um as a sort of proof of principle about
some of the ways that we might think of
computation as being sort of a
fundamental principle for dynamical
systems and maybe the the evolution of
the universe as a whole they're a great
model system
as an explanatory framework for life i
think
they're a bit problematic for the same
reason that
the laws of physics are a bit
problematic um and the clearest way i
can articulate that is like cellular
automata are actually cast in sort of a
conceptual framework for how the
universe should be described that goes
all the way back
to newton in fact with this idea that we
can have a fixed law of motion
which exists sort of it's given to you
you know the great programmer in the sky
gave you this equation
or this rule and then you just run with
it um and the rule doesn't have so a
good feature of the rule is it doesn't
have specified in the rule information
about the patterns it generates so you
wouldn't want for example the my cup or
my water bottle or you know me sitting
here to be specified in the laws of
physics that would be ridiculous because
it wouldn't be a very simple explanation
of all things happening i'd have to
explain everything
so and tell your time to have that
feature
and the laws of physics have that
feature
um but but you know you also need to
specify the initial condition um and it
also it basically means that everything
that happens is sort of a consequence of
that initial condition and i think this
kind of framework is just not the right
one for biology um and part of the way
that it's easiest to see this is
um a lot of people talk about
self-reference being important in life
the fact that um you know like the
genome has information encoded in it
that information gets read out
um it specifies something about the
architecture of a cell
the architecture of the cell includes
the genome so the genome has basically
self-referential information
self-reference obviously comes up in
computational law because it's kind of
foundational um to turing's work and
what girdle did with the incompleteness
theorems and things so there's a lot of
parallels there and and people have
talked about that at depth um but the
other way of kind of thinking about it
in terms of like a more physics-y way of
talking about it
is that what it looks like in biology is
that the rules or the laws depend on the
state this is typical in computer
science this is obvious to you you know
the update rule depends on the state of
the machine right but and you know you
don't think about um
uh you know that being sort of the
dynamic and physics it's you know the
rules given to you and then it you know
it's a it's a very special subclass say
of computations if
you know you don't ever change the
update um but in biology it seems to be
that the state and the law change
together as a function of time and we
don't have that as a paradigm in physics
and so a lot of people talked about this
as being kind of a perplexing feature
that maybe there are certain scenarios
where the laws of physics or the laws
that govern a particular system actually
change as a function of state of that
system that's trippy so yeah the the
hope of physics it's a hope i guess but
often stated as a
underlying assumption is that the law
is uh static right
okay and even having laws that vary in
time and not even as a function of the
state is very radical
when you the time in general like yeah
you want to remove time from the
equation as much as possible yeah i i do
um there's some interesting things in
this like when we think it's sort of
deep more deeply about the actual
physics that we're trying to propose
governs life um with me with
collaborators and then also other people
that think about similar things that
time might actually be fundamental and
there really is an ordering to time
um and that events in the universe are
unique because they have a particular
you know they they happen like an object
in the universe requires a certain
history of events in order to exist
which therefore suggests that time
really does have an ordering i'm not
talking about the flow of time and our
perception of time just the ordering of
events causation yes causation there's
that word again
so causation that's when you say time
you mean causation yes
in your proposed model
of the physics of life the the
fundamental thing would be causation if
you were to bet your money on on one
particular horse or whatever yes and
then space is emergent
yes so everything's emergent except time
kind of yeah or causation
change all the time why it look like
laws are the same laws well because uh
well one way um and i actually this idea
comes from lee cronin because i work
with him very closely on these things is
that the laws of physics look the way
they do because they're low memory laws
so they don't require a lot of
information to specify them they're very
easy for the universe to implement but
if you get something like me for example
i require 4 billion year history to
exist in the universe i come with a lot
of historical baggage
and that's part of what i am as a set of
causes that exist in the universe
so i have local rules that apply to me
that are associated with sort of the
information in my history
that aren't universal to every object in
the universe
and there are some things that are very
easily easy to implement low memory
rules that apply to everything in the
universe
so there's no shortcuts to you no i so
yeah i don't believe in like things like
boltzmann brains or
uh you know fluctuations out of the
vacuum that can produce things like your
desk ornaments
i actually think they require a
particular causal chain of events to
exist
well i appreciate the togetherness of
that but uh so how does that
if we have to simulate the entire
universe to create the ornaments and the
two of us
how are we supposed to create
engineer life yeah that's not
this goes back to sort of the critique
of the rna world i think one of the
problems and i'll get to answering your
question but i think this is kind of
relevant here one of the problems with
the rna world
when we test it in the laboratory is how
much information we're putting into the
experiment
we specify the flasks we make pure
reagents we mix them we take them out we
put them in the next flask we change the
ph we change the uv light and then we
get a molecule and it's not even an rna
molecule necessarily it might just be a
base right um and so
people don't usually think about the
fact that we're agents in the universe
making that experiment and therefore we
put a little bit of life into that
experiment
um
because it's part of our biological
lineage in the same sense that a couple
or i am a part of the biological lineage
the experimental ideas
are
injecting life yes
and the constraints that we put on the
experiments because those conditions
wouldn't exist in the universe on planet
earth at that time without us as the
boundary condition right so
even though we're not actually adding
any actual like chemistry or biology
that it could be identified as life
are the constraints we're adding to the
experiment the design of the experiment
yeah you can think of a design
experiment as a program you put
information in it's an algorithmic
procedure that you design the experiment
and so um so the original life problem
becomes one of minimizing the
information we put into physics
to actually watch the spontaneous
original life can we can we have so can
is it possible in the lab to have an
information vacuum then so like if we
could we would that would be amazing i
don't know that's a good question for
more for lee yeah you guys by the way
for people who don't know lee cronin is
uh
you guys are uh colleagues and uh
i've gotten a chance to listen to the
two of you talking there's great sort of
chemistry and you're brilliant
brainstorming together and there's
there's a really exciting
community here of of brilliant people
from different disciplines working on
the problem yeah of life of complexity
of uh
i don't know whatever
the words fail us to describe the exact
problem we're trying to actually
understand here intelligence all those
kinds of things
okay so
what what uh
from a lab perspective so lee i guess
would you call him a chemist no i think
by training he's a chemist but i think
most of the people that work in the
field we do have lost their discipline
that's why i couldn't answer your
question
okay i don't know what you call them
yeah i don't know what i call myself i
don't know what i call any of my friends
so why why is it so hard to create uh
and it's an interesting question to
create biological life in the lab
like from your perspective
is that an important problem to work on
to try to recreate the historical origin
of life on earth or echoes of the
historical origin i think echoes is more
appropriate i don't think asking the
question of what was the exact
historical sequence of events and
engineering every step in the process to
make exactly the chemistry of life on
earth as we know it is a meaningful way
of asking the question and it's a little
bit like
um you know if
since you're in computer science like if
you know the answer to a problem it's
all it's easier to find a program to
specify the output right but if you
don't know the answer or priority you
know finding an algorithm for like say
finding a prime or something it's easy
to um you know
uh verify it's a prime number it's hard
to find the next prime um and uh
the way the original life is structured
right now in the historical problem is
you know the answer and you're trying to
retrodict it by breaking it down into
the set of procedures where you're
putting a lot of information in and what
we need to do is ask the question of
how is it
that the rules of how our universe is
structured permits things like life to
exist and what is the phenomena of life
and those questions are obviously
essentially the same question and so
you're looking essentially for this
missing
physics this missing explanation for
what we are and you need to set up
proper experiments that are going to
allow you to probe
the vast complexity of chemistry in an
unconstrained way with as little
information put in as possible to see
when things
when does information actually emerge
how does it emerge
what is it
and
part of the the sort of conjecture we
have is
that this physics only becomes relevant
or at least this is this is my personal
conjecture and um and it's sort of
uh validated by this kind of theory
experiment collaboration
um
that we we have working in this area
um that this you know sort of i made the
point about like gravity existing
everywhere right but when you study um
an atomic nucleus you don't care about
gravity it's not relevant physics there
right it's it's weak it doesn't matter
and so
this idea that that there's kind of a
physics associated with information
for me
it's very
evident that that physics doesn't become
relevant until you need information to
specify the existence of a particular
object and the scale of reality where
that happens is in chemistry because of
the combinatorial diversity of chemical
objects that can exist far outs
exceeds the amount of resources in our
universe so if you want to you can't
make every possible protein of length um
you know 200 amino acids there's not
enough resources so in order for this
particular protein to exist and this
protein to exist in high abundance means
that you have to have a system that has
knowledge of the existence of that
protein and can build it so existence
comes to be at the chemical level so
existence is most
uh is uh best understood at the chemical
level it's most evident
it's a little bit like nobody argues
that gravity doesn't exist in an atomic
nucleus it's just not relevant physics
there so the physics of information
is everywhere it exists at every
combinatorial scale but it becomes more
and more relevant the more set of
possibilities that could exist
because you're you're you're you have to
specify more and more about why this
thing exists and not the infinite it's
not an infinite set but you know the set
of undefined set of other things that
could exist so can ask a weird
yeah question which is
so let's look into the future
i try that every day it never works
so say a nobel prize is given in physics
maybe chemistry
for discovering the origin of life
no not but not the historical origin
some kind of thing that we're talking
about
what exactly
would
what do you think
that like what do you think that person
maybe you did to get that nobel prize
like what would they have to have done
because you could do a bunch of
experiments that go like with an aha
moment
like you rarely get the nobel prize
for like you've solved everything we're
done right it's like some inkling of
some deep truth right like what do you
think that would actually look like
would it be an experimental result
uh i mean it will have to have some kind
of experimental maybe validation
component so what would that look like
this is an excellent question
i want to
sorry i'm going to make a quick point
which is just a slight tangent but you
know like when people ask about the
origin of mass you know and like looking
for the higgs mechanism and things they
never like we need to find the
historical origins of life in the early
unit although those things are related
right so um so this problem of origins
of life in the lab i think is really
important but the the higgs is a good
example because you had theory to guide
it so somehow you need to have an
explanatory framework
that
can say that we should be looking for
these features
and explain why they might be there and
then be able to do the experiment and
demonstrate that it matches with the
theory but it has to be something
that is outside sort of the paradigm of
what we might expect based on what we
know right so this is a really sort of
tall order
um and
i think um
i mean i i guess the way people would
think about it is like you know if you
had a bacteria that climbed out of your
test tube or something and it was like
you know moving around on the surface
that would be ultimate validation you
saw the original life in an experiment
but i don't think that's quite what
we're looking for i think what what
we're looking for is evidence of when
information that originated within
the bounds of your experiment and you
can demonstratively prove emerge
spontaneously in your experiment wasn't
put in by you
actually started to govern the future
dynamics of that system and specify it
and you could somehow relate those two
features directly so you know that the
program specifying
what's happening in that system is
actually internal to that system like
say you have a chemical thing in a box
well
so that's that's one nobel prize with
the experiment which is like
information in some fundamental way
originated
within the constraints of the system
without you injecting anything but
another experiment is
you injected something yeah
and got out information yes so like you
injected
i don't know like uh
like some sugar and like something
something that doesn't necessarily feel
like it should be information yeah so i
actually no i mean sugar is information
right so part of the argument here is
that every physical object
is
well it's information but it's a set of
causal histories and also a set of
possible futures so there's an
experiment um that i've talked a lot
about uh with lee cronin but also with
michael lockman and chris kempies who
are at santa fe about this idea that
sometimes we talk about is like seating
assembly um which is you take a high
high complexity like a an object that
exists in the universe because of a long
causal history and you seed it into a
system of lower causal history and then
suddenly you see all of this complexity
being generated so i think another
validation of the physics would be
say you engineer an organism by by
purposefully
introducing something where you
understand the relationship between the
causal history of the organism
and the say very complex chemical set of
ingredients you're adding to it and then
you can predict the future evolution of
that system to some
statistical
uh set of constraints and possibilities
for what it will look like
in the future
you know i'm a physical structure
obviously like i i'm composed of atoms
the configuration of them and the fact
that they happen to be me
is because i'm not actually my atoms i
am a informational pattern that keeps
re-patterning those atoms into sarah um
and i have also associated to me is like
a space of possible things that could
exist
that i can help mediate come into
existence because of the information in
my history
and so
when you understand sort of that
time is a real thing embedded in a
physical object
then it becomes possible to talk about
how
histories when they interact
and history is not a unique thing it's a
set of possibilities when they interact
how do they specify what's coming next
and then where does the novelty come
from in that structure because some of
it is kind of things that haven't
existed in the past can exist in the
future
let me ask about this entity that you
call sarah yes i talk to myself about
myself in third person sometimes i don't
know why
uh
so maybe this is a good time to bring up
consciousness sure
it's been here all along
wow
has it so what i mean at least in this
conversation i think i've been conscious
most of it but maybe i haven't well yeah
speak so speak for yourself you're
you're you're projecting your
consciences onto me you don't know if
i'm conscious or not is it
um you're right is that uh
he talked about the physics of existence
he talked about the emergence of um
of causality uh sorry you talked about
causality and time being fundamental to
the universe
does consciousness fit into all of this
like uh
do you draw any kind of inspiration or
value with the idea of pan psychism
that maybe one of the things that we
ought to understand is the physics of
consciousness
like
one of the missing pieces
in the physics view of the world is
understanding the physics of
consciousness or like that word
has so many concepts underneath it but
let's put it
let's put consciousness as a label on a
black box of mystery that we don't
understand
do you think
that black box holds the key
to uh finally answering the question of
the physics of life
the problems are absolutely related i
think um most and i'm interested in both
because i'm just interested in what we
are and to me the most interesting
feature of what we are is our minds and
the way they interact with other minds
like minds are the most beautiful thing
that exists in the universe so how did
they come to be
i'm sorry to interrupt so when you say
we you mean humans i mean humans right
now but i but that's because i'm a human
i think i am you think there's something
special to this particular no no no um
no um
i don't i'm not a human-centric thinker
but are you one entity you said a bunch
of stuff came together to make a sarah
like
yourself
as one entity are you just
a bunch of different components like is
there any value to understand the
physics of sarah like or are you just a
bunch of different things that are like
a nice little temporary side effect yeah
you could think of me as a bundle of
information that just became temporarily
aggregated or individual yeah that's
fine i agree with that view
um
okay i think that is a compliment
actually but you you've
but nevertheless that bundle of
information has become conscious or at
least keeps calling her self-conscious
yeah i think i'm conscious right now but
i might not be but that's okay um or you
wouldn't know um so yeah so this is the
problem so yeah usually people when
they're talking about consciousness are
worried about the subjective experience
and so i think that's why you're saying
i don't know if you're conscious because
i don't know if you're experiencing this
conversation right now
um and nor do you know if i'm
experienced in the conversation right
now
and so this is why this is called the
hard problem of consciousness because it
seems impenetrable from the outside to
know if something's having a conscious
experience um
and i really like um
the idea of also like the hard problem
of matter which is related to the hard
problem of consciousness which is you
don't know the intrinsic properties of
an electron not interacting say for
example with anything else in the
universe all the properties of anything
that exists in the universe are divine
by its interaction because you have to
interact with it in order to be able to
observe it so we can only actually know
the things that are observable from the
outside and so this is one of the
reasons that consciousness is hard for
science because you're asking questions
about something that's subjective and
supposed to be intrinsic to what that
thing is as it exists and how it feels
about existing
and so
i have thought a lot about this problem
and its relationship to the problem of
life and the only thing i can come up
with to try to make
that problem
scientifically tractable
and also related to how i think about
the physics of life
is to ask the question
are there things that can only happen in
the universe because
there are physical systems that have
subjective experience
so does subjective experience have
different causes
that things that it can cause to occur
um
that would happen in the absence of that
i don't know the answer to that question
but i think that's a meaningful ask way
of asking the question of consciousness
i can't ask if you're having experience
right now but i can ask if you having
experience right now changes something
about you and the way you interact with
the world
so
does stuff happen it's just it's a good
question to ask this stuff happen if
consciousness is
then it's a real physical thing right it
has physical consequences i'm a
physicist i'm biased so i don't you know
i can't get rid of that bias it's really
deeply ingrained um i've tried
but but i mean you're saying information
is physical too so like virtual reality
and stimulation all that program is
physical too yes everything's physical
it's just not physical the way it's
represented in our minds
right so you i love your twitter so you
tweet these like deep thoughts
and deep dust that's what a theorist
does when she's trying to experiment
is tweet it's just like
sitting there i mean i can just imagine
you sitting there for like hours and all
of a sudden just like this thought comes
out and you get a little um
like inkling into the thought process
yeah usually it's like when i'm running
between things
articulate one of the things you tweeted
is ideologically there are many
parallels between the search for neural
correlates of consciousness and for
chemical correlates of life how the
neuroscience and astrobiology
communities treat those correlates is
entirely different
can you elaborate against this kind of
yeah the parallels it has to do a little
bit with the consciousness and the
and the matter thing you're talking
about yeah it does and i i can't
remember what state of mind i was when i
was actually thinking about that but um
but i think part of it is but you never
thought you're gonna have to analyze
your own twitter no i didn't it's an
interesting uh historical juxtaposition
of thinking so the tweet is a historical
uh
you're doing an assembly experiment
right now because you're bringing a
thought from the past into the present
and trying to actually in the lab
yeah yeah this is this is experimental
science right here okay on the podcast
live
um
so so go let's see how the consciousness
evolves on this one yeah so um in
neuroscience it's kind of accepted that
we can't get the subjective
aspect of consciousness so people are
very interested in what would be a
correlate of consciousness so
um
so
that's a correlation a correlate is a
feature
that relates to conscious activity so
for example um you know a verbal report
is a correlate of consciousness because
um you know i can tell you when i'm
conscious
and then when i'm sleeping for example i
can't tell you i'm conscious so we have
this assumption that you're not
conscious when you're sleeping and
you're conscious when you're awake yeah
um and so so that's sort of like a a
very obvious example but uh
neuroscientists which you know i'm no
neuroscientist and i'm not an expert in
this field so um but you know they have
very sophisticated ways of measuring you
know activity in our brain and trying to
relate that to verbal report and other
proxies for whether someone is
experiencing something um and that's
what is meant by neural correlates
um and then so when people are trying to
think about
um
studying consciousness or developing
theories for consciousness they often
are trying to build an experimental
bridge to these neural correlates
recognizing the fact that a neural
correlate may or may not correspond
to consciousness because that problem's
hard and there's all these associated
issues to it
so that that's from a neuroscience
perspective it's like fake it till you
make it so you pretty much yeah you fake
whatever the correlates are and
hopefully that
the uh that's going to uh summon
the thing that is consciousness or
something like that and so the same
thing on the chemical
correlates of life is it that sounds
like that's an awesome concept is that
something that people no i just made
that up okay that was the originals to
that tweet you can cite the tweet
maybe i'll write it in a paper someday
uh chemical correlates of life that's a
good title i mean first of all your your
papers too that people should check out
have great titles
or paper papers you're involved with
so your tweets and titles are are
stellar and also your ideas but the
tweets and titles are much more
important of course so these will live
longer
yeah
they're much more diffused though um
well it's yeah it's the
tweet is the trojan horse or the idea
that that sticks on for a long time okay
so is there anything to say about the
chemical coils you're saying
there are similar kind of ways of
thinking about it
but uh
you you mentioned about the communities
yeah so i think in astrobiology it's not
um
there's no concept of chemical
correlates of life we don't think about
it that way we think if we find
molecules that are involved in biology
we found life
so i think i i i think one of my
motivations there was just to separate
the fact that
life has abstract properties associated
to it they become imprinted in in
material substrates um and those
substrates are correlates for that thing
but they are not necessarily the thing
we're actually looking for the thing
that we're looking for is the physics
that's organizing that system to begin
with not the particular molecules
um in the same sense that that you know
your consciousness is not your brain
it's it's it
it's instantiated in your brain that you
know it has to have a physical substrate
but it's not the
the matter is not the thing that you're
looking at it's some other at least not
in the way that we have come to look at
matter you know with traditional physics
and things there's there's something
else there and it might be this feature
of history i was talking about our time
being
actually you know physically represented
there
do you think consciousness can be
engineered
yes
in the same way that life can be well
that was a fast answer i didn't even
think about that that's interesting
you don't have a free will that was no i
do have free will but it's interesting
because some i mean
i you know you know you're backtracking
no no that was predestined yeah no no
no i do believe in free will but i also
think that there's kind of kind of an
interesting um
you know like what you're you speaking
about consciousness what are you
consciously aware of versus like what is
your subconscious brain actually
processing and doing and and sometimes
there's conflict between your
consciousness and your subconsciousness
or your consciousness a little slower
than your subconscious and intuition is
a really important feature of that and
so a lot of the ways i do my science is
guided by intuition
so when i give fast answers like that i
think it's usually because i haven't
really thought about them and therefore
that's probably
telling me something let's continue the
deep analysis of your tweets
[Laughter]
you said that determinism in a tweet
determinism and randomness play
important roles in understanding what
life is
so let me ask on this topic of free will
what is determinism what is randomness
and why the heck do they have anything
to do with understanding life
yeah
and you threw free will in there just
throwing all the the stuff in the bag
are they not related no no they are they
are related then no no that's all right
i was being unfair you didn't even
capitalize the tweet by the way it was
all lower case i must have been angry oh
that was was saying can you analyze the
emotion behind that no i actually did
frustration yeah maybe so
i already argued that i don't think that
can happen without that whole causal
history and so i guess in some sense um
the determinism for me arises because of
the causal history
um and i'm not really sure actually
about whether the universe is random or
deterministic i just had this sort of
intuition for a long time i'm not sure
if i agree with it anymore but it's
still kind of lingering and i don't know
what to do with this question but it
seems to me you know so there's you ask
the question what is life but you could
also why life why does life exist what
does the universe need life for not that
the universe has needs but you know we
have to anthropocentrize things
sometimes to talk about them um and i
had this feeling that if it was possible
for
a cup or a desk ornament or a phone on
mars to spontaneously fluctuate into
existence the universe didn't need life
to create those objects it wasn't
necessary for their existence it was
just a random fluke event and so somehow
to me it seems that
it can't be that those things formed by
rand random processes they actually have
to have a set of causes that
accrue and form those things and they
have to have that history and so it
seems to me that that life was
somehow deeply related to the question
of whether the underlying rules of our
universe had randomness in them or they
were fully deterministic and in some
ways you can think about life as being
the most deterministic part of physics
because it's where the causes are
um
precise in some sense um or most stable
so like most stable yes most reliable
most reliable for for our
for how we for the tools of physics but
what um right well so where's the
randomness come from then if okay so you
you were at
uh speaking with i've gone in a tangent
so i'm not sure where we are in the yeah
all of the universe is a kind of tangent
so uh we're embracing the tangent so
free will
you believe
at this current time that you have free
will i believe my whole life i have free
will what is illusion
i still believe it you still believe it
so uh at the same time you think that
in your conception of the universe
causality seems to be pretty fundamental
that's right which kind of wants the
universe to be deterministic
so how the heck
because i mean you think you have a free
will and yet you value causality
um
because i depart from the
conception of physics that you can write
down
an initial condition and a fixed law of
motion and that will describe everything
there's no incompatibility if you are
willing to reject that assertion so
where is the randomness where's the
magic that gives birth to the free will
is it the randomness of the laws of
physics
no free um
in my mind what free will is is the fact
that i
i as a physical system have causal
control over certain things i don't have
causal control over everything but i
have a certain set of things and i'm
also
um you know as i described sort of a
nexus of a particular set of histories
that exist in the universe on a
particular set of futures that might
exist
and those futures that might exist are
in part specified by my physical
configuration as me
um and
therefore
you know it may not be free will in the
traditional sense i don't even know what
people mean when they're talking about
free will honestly it's like the whole
discussion is really muddled but in the
sense that i am a causal agent if you
want to call it that that exists in the
universe and there are certain things
that happen because i exist as me
then yes i have free will no but
do you
sarah have a choice about what's going
to happen next oh i see um if the
universe could i have if i run this yes
i think so you have a choice
where's the choice come from is it i
think that's related to the physics of
consciousness so one of the things i
didn't say about that i don't know maybe
this is me just being hopeful
um because i maybe i just want to have
free will but i don't think that we can
rule out the possibility because i don't
think that we understand enough about
any of these problems but i think one of
the things that's interesting for me
about the sort of inversion of the
question of consciousness that i
proposed
is one of the features that
that we do
is we have imagination right and people
don't think about imagination as a
physical thing but it is a physical
thing it exists in the universe right um
and so i'm like really intrigued by the
fact that say humans for
you know another physical system could
do this too it's not special to humans
but uh you know for centuries imagined
flying machines and rockets and then we
finally built them right so they were
they were represented in our minds and
on the pages of things that we drew
for hundreds of years before we could
build those physical objects in the
universe
but certainly the existence of rockets
is in part
causally
you know caused by the fact that we
could imagine them
um and so um
so there seems to be this property that
some things don't exist they've never
physically existed in the universe but
we can imagine the possibility of them
existing and then cause them to exist
maybe individually or collectively um
and i think that property is related to
what i would say about having choice or
free will because that set of
possibilities that thing those set of
things that you can imagine is not
constrained to your local physical
environment and history and this is
what's a little bit different about
intelligence as we see it in humans and
ai that we want to build than biological
intelligence because biological
intelligence is predicated completely on
the history of things it's seen in the
past but something happened with the
neural architectures that evolved in
multicellular organisms that they don't
just have access to the past history of
their particular you know set of events
but they can imagine things that haven't
happened aren't on their timeline and as
long as they're consistent with the laws
of physics make them happen
so
this is fascinating
physics but it exists so there you go i
mean in some sense if you look at like
general relativity and gravity morphing
space time
in that same way maybe whatever the
physics of consciousness might be
it might be morphing that's like what
free will is it's morphing like
the space just like ideas make rockets
come to life
it's somehow
changing the space of possible
realizations of like whatever's
yeah okay but life is kind of basically
if you want to think about it like life
is sort of changing the probability
distributions over what can exist that's
the physics of what life is and then
consciousness is a sort of layered
property your imagination on top of it
that kind of scrambles that a little bit
more and like has you know access to i
don't i don't know it's it's kind of
it we don't know how to describe it
right like that's why it's interesting
but it's probabilistic so you do think
like god plays dice so let me um no i
think the description's probabilistic i
don't necessarily think
the um
underlying physics is probabilistic i
think i think i think the way that we
can describe this physics is going to be
probabilistic and statistical but the
under like when we take measurements in
the lab but the underlying physics
itself might still be deterministic i
don't
i don't know maybe i'm i it's hard to
know what concepts to hold on to so i
find myself constantly rejecting
concepts but then i have to grab another
one and try to hold on to something from
intellectual history right well it's
possible that our mind is not able to
hold the correct concepts of mind at all
like right we're not able to even
conceive of them correctly maybe the
words deterministic or random are not
the right even words concepts to be to
be holding but
maybe you can talk to the theory of
everything uh the this attempt in the
current set of physical laws to try to
unify them is there any hope that
once
a theory of everything is developed and
by theory of everything i mean in a
narrow sense of unifying quantum field
area and general relativity do you think
that will contain some
like in order to do that unification you
would have to get something that would
then give hints about the physics of
life physics of existence
physics of consciousness yeah
i used to not but i actually uh i have
become increasingly convinced that
it probably will
um and part of the reason is um i think
i've talked a little bit already about
these holes in physics like these
the the theories we have in physics you
know they have problems they have lots
of problems um and they're very deep
problems um and we don't know how to
patch them um and some of those problems
become very evident when you try to
patch um quantum mechanics and general
relativity together
so there is this kind of interesting
feature that some of the ways of
patching that might actually um closely
resemble
uh the physics of life and so the place
where that actually comes up most and
actually we just had a workshop in the
beyond center where i work at arizona
state university
um and lee smolin made this point that
he thinks that the theory of quantum
gravity when we solve it is going to be
the same theory that gives rise to life
um and i think that i agree with him on
some levels because there's something
very interesting where if you look at
these sort of causal set theories of
gravity where they're looking for space
um
as being emergent
and so space time is an emergent concept
from a causal set which is is also sort
of related i think to what wolfram's
doing with his physics project um it's
the same kind of underlying math that we
have in in this theory that we've been
developing related to life called
assembly theory um which is you know
basically trying to look at
complex objects like molecules and
bacteria and living things
as
sort of uh
as basically being assembled from a set
of component parts
and that they actually encode all the
possible histories that they could have
in that physical object so the
mathematically all these ideas i think
are related i think a lot of people are
thinking about this from
different perspectives and then
constructor theory um that david deutsch
and kiara marletto have been developing
is a totally different angle on it but i
think getting at some similar ideas so
it's a really interesting time right now
i think for the frontiers of physics and
how it's relating um to maybe deeper
principles about what life is so short
answer yes long-winded answer rewind
can we talk about aliens
anytime
so one
i think one interesting way to sneak up
on the question of what is life
is
to ask what should we look for in alien
life
you know if we were to look out into our
galaxy and enter the universe and come
up with a framework of how to detect
alien life
what should we be looking for
is there
like set of rules
uh like it's both the tools
and the tools that are
service census for certain kind of
properties of life
so what should we look for
in alien life yeah so we have a paper
actually coming out monday which is
collaboration um it's actually really
lee cronin's lab but my group worked
with him on it and we're working on the
theory which is this idea that we should
look
for life um as high assembly objects
what we mean by that is
which is actually observationally
measurable and this is one of the
reasons that i started working with leon
these ideas is because being a theorist
it's easy to work in a vacuum it's very
hard to connect abstract ideas about the
nature of life to anything that's
experimentally tractable
but what his lab has been able to do is
develop this method where they look at a
molecule and they break it apart into
all its component parts and so you say
you have some elementary building blocks
and you can build up all the ways of
putting those together to make the
original object and then you look for
the shortest path in that space
and you say that's sort of the assembly
number associated to that object
and if that number's higher it assumes
that a longer causal history is
necessary to produce that object or more
information is necessary to specify the
creation of that object in the universe
now that kind of
idea at a superficial level has existed
for a long time that kind of idea as a
physical observable of molecules is
completely novel and what his lab has
been able to show
is that if you look at a bunch of
samples of non-biological things and
biological things there's this kind of
threshold
of assembly where
as far as the experimental evidence is
and also your intuitive intuition would
suggest
that by non-biological systems don't
produce things with high assembly number
so this goes back to the idea like a
protein is not going to spontaneously
fluctuate into existence on the surface
of mars it requires an evolutionary
process and a biological architecture to
produce a protein you generalize that
argument you know a complex molecule
or a cup or a desk ornament
in this sort of abstract idea of
assembly spaces as being the causal
history of objects and you can talk
about the shortest path from elementary
objects to an object given an elementary
set of operations
and you can experimentally measure that
with mass spec and that's basically sort
of the idea that's really fascinating i
can't get out of my head and start
imagining legos and all the legos i've
ever built and how many steps what is
the shortest path to the final right
right to find a little lego castles
so they so yeah so then like asking
about going to look for alien life the
idea is
you know most the instruments that nasa
builds for example or any of the space
agencies looking for life in the
universe are looking for chemical
correlates of life right but here we
have something that
is based on properties of molecules it's
not a chemical correlate it's agnostic
it doesn't care about the molecule it
cares about
what is the history necessary to produce
this molecule
how complex is it in terms of how much
time is needing how much information is
required to produce it so when you
observe a thing on another planet you're
essentially
the process looks like reverse
engineering trying to figure out what is
the shortest path to create that thing
yeah so most yeah and i would say most
like most examples of biology or
technology don't take the shortest path
right but the shortest path is a bound
on how hard it is for the universe to
make that yeah and so i guess what you
and lee are saying that there's a
heuristic that's a good
metric for uh like better perhaps than
chemical correlates yes because it
doesn't it's not contingent on looking
for the chemistry of life on earth on
other planets
and it also has a deeper explanatory
framework associated to it as far as the
kind of theory that we're trying to
develop associated to what life is and i
think this is one of the problems i have
in my my field personally in
astrobiology is people observe something
on earth say oxygen in the atmosphere or
an amino acid in a cell and then they
say let's go look for that on another
planet
let's look for oxygen on exoplanets or
let's look for amino acids on mars and
then they assume that's a way of looking
for life
um
and it
or even phosphine on venus but you know
like there's all these examples of let's
look for one molecule a molecule is not
life life is a system that patterns
particular structures into matter that's
like it's that's what it is and it
doesn't care what molecules are there
it's something about the patterns and
and that structure and that history um
and if you're looking for a molecule
you're not testing any hypotheses about
the nature of what life is it doesn't
tell me anything if we discover oxygen
and exoplanet about what kind of life is
there just oxygen on an exoplanet it's
not there there's
i i guess i think like when you think
about the question are we alone in the
universe that's a pretty freaking deep
question it should have a freaking deep
answer it shouldn't just be there's a
molecule and an exoplanet wow we solved
the problem it should tell us something
meaningful about our existence and i
feel like we've fallen short on how
we're searching for life in terms of
actually searching for things like us
in this kind of deeper way
but how do you do that initial kind of
say i'm walking down the street and i'm
looking for that double take test of
like
like what the hell is that like that
that initial
like how do we look for
the possibility of weirdness at the
possibility of high assembly number well
yeah
if they don't have two eyes and are
green
you know i would have probably already
solved the problem right there's another
nobel prize in there somewhere i think
actually
um
well i think it's it's kind of so so
there is a bias here right so
we've evolved to recognize life on earth
right like i you know children at a very
early age can tell the difference
between a puppy and a plant and then the
plant and a chair for example you know
like it just it seems innate um and so i
think and also because we're life
um
you know i think like there's this
implicit bias that we should know it
when we see it and it should be
completely obvious to us
um but there are a lot of features of
our universe that are not completely
obvious to us like the fact that this
table is made of atoms and that i'm
sitting in a gravitational potential
well right now um and i guess um
my point with this is i think life is
much
less obvious than we think it is
and so it could be in many more forms
than we think it is um and i guess let's
go back to the point about being
open-minded that we may not know what
alien life looks like it might not even
be possible to interact with alien life
because maybe
something about you know our our
informational lineage it makes it
impossible for information from an alien
to be copied to us therefore there's no
you know
so to speak communication channel and i
don't mean you know verbal communication
just
it's not in our observational space like
you know like you know there's there's
fundamental questions about why we
observe the universe in position rather
than momentum but we also you know
observe it in terms of certain
informational patterns and things like
that's what our brain constructs and
maybe aliens just interact with a
different part of reality than we do
that's wildly speculative but i think i
think um
it's possible it's possible and i think
it's consistent with the physics so i
think the best ways we can ask questions
are about
life and chemistry and asking questions
about if information is a real physical
thing what would its signatures be in
matter
um
and and how do we recognize those and i
think the ones that are most obvious are
the ones i've already articulated you
have these objects that seem completely
improbable for the universe to produce
because the universe doesn't have the
design of that object in the laws
so therefore an object had to evolve
we we talked we call it evolution but it
had to be produced by the universe that
then had all of the possible tasks to
make that object
um specified i mean there's some like
there's an engineering question here of
are there sensors we can create that can
give us uh
can help us discover certain pockets of
high assemblies yeah aliens
like
i mean there is a hope
setting dogs and chairs aside
there's a hope that visually
and we could detect
like
because our universe i mean at least the
way we look at it now like this
three-dimensional like space-time
we can visually comprehend it
it's interesting to think like if we got
to hang out you know if there's an alien
in this room
like would we be able to detect it with
our current sensors not the fancy kinds
but but like what you're standing over
there
yeah standing over there or maybe like
in this carpet see there's all these
kinds of patterns right yeah uh i don't
know
if if
i don't know if this carpet is an alien
well so
i see what you're saying um
so assembly theory is pretty general
like i mean we've been applying it to
molecules because it makes sense applied
to molecules but it's supposed to
explain life
um you know like the physics of life so
it should explain you know the things in
this room in addition to molecules um so
i guess uh and you can apply it to
images and things so i guess the idea
you know you could explore is just
looking at everything on planet earth in
terms of its assembly structure and then
looking for
things that aren't part of our
biological lineage if they have high
assembly they might be aliens on earth i
mean that that is a very kind of
rigorous computer vision question can we
visually
is there a strong correlation
between certain kind of high assembly
objects when they get to the scale where
they're visually observable
and
some like when it's
say uh projected onto a 2d plane can we
right can we figure out something right
i am glad you brought up a computer
vision point because for a while i had
this kind of thought in my mind that we
can't even see ourselves clearly so one
of the things you know people are
worried about artificial intelligence
for a lot of reasons but i think it's
really fascinating because it's like the
first time
in history that we're building a system
that can help us understand ourselves
so like you know people talk about ai
physics but like um
you know when i when i look at another
person i don't see them as a four
billion year lineage but that's what
they are and so is everything here right
so
imagine that we built artificial systems
that could actually
see that feature of us
what else would they see
and i think that's what you're asking
and i think i think that would be so
cool
i want that to happen but i think i
think we're a little ways off from it
but yeah
we're going there i hope
okay let me ask you uh i apologize ahead
of time but let me ask you the internet
question so you're a physicist you ask
rigorous questions about the physics of
existence and
these models of high assembly objects
now when the internet would see an alien
they would ask two questions one can i
eat it and two can have sex with it yes
so
so you kind of mentioned that it's very
difficult it's possible that we may not
be even able to communicate with it
right but i think the internet has more
hope than we do yes it's a hopeful place
yes uh do you
do you think in terms of like
interacting on this very primal level of
of sharing resources like what would
aliens eat what would we eat would we
eat the same thing would could we
potentially eat each other uh one one
person eats the other or or the aliens
eat us and the same thing with
not sex in general reproduction but
genetically mixing stuff like would we
would be able to mix genetic information
maybe not genetic but maybe information
right and i think part of your question
is like so
so if you if you think of life as like
this history of events that happen in
the universe like there's this question
of like how divergent are those
histories right so when we get to the
scale of technology it's possible to
imagine
imagine although we can't even do it
like imagine all the possible
technologies that could exist in the
universe but if you think about all the
possible chemistries somehow that seems
like a lower dimensional space and a
lower set of possibilities so it might
be that like when we interact with
aliens we do have to go back to those
more
basal levels to figure out sort of what
the map is
right um like the sort of where we have
a common history we all we must have a
common history somewhere in the universe
but in order to be able to actually
interact in a meaningful way you have to
have some shared history i mean the
reason we can exchange genetic
information in each other's food or eat
each other as food
is because we have a shared history so
we have to find that shared history the
other we have to find the common
ancestor in this causality map the the
something yes
yes and we have a last universal common
ancestor for all life on earth which i
think is sort of the nexus of that
causality map for life on earth but the
question is where would other aliens
diverge on that sound
and i mean
that
so say there's a lot of aliens out there
in the universe each each set of
organisms will probably have like a
number you know like erdos number of
like
how far
like how far our common ancestor is and
so the closer the common ancestor like
it is on earth
the more like each other the more likely
we are to be able to have sexual
reproduction well it's like sort of like
humans having common culture and
languages right yeah exactly language
communication
it might take a lot of work though with
an alien because you really have to get
over a language barrier
oh boy so it says communication it's uh
uh resources i mean it's all the whole
and i think tied into that is the
questions of like who's gonna harm who
right and actually definitions parents
approve you know all those kind of
questions
whether the common ancestor approves
yeah that's just very true uh
how many alien civilizations do you
think are out there
i don't have intuition for that
um which i i have always thought was
deeply intriguing so and and part of
this uh
i mean i say it specifically is i don't
have intuition for that because it's
like one of those questions that you
feel around for a while and you really
just you you can't see it um even though
it might be right there and
um
in that sense it's a little like the
quantum to classical transition you're
like really talking about two different
kinds of physics and i think that's kind
of part of the problem once we
understand the physics that question
might become more meaningful
um but there's also this other issue um
uh and this was really instilled in me
by my mentor paul davies when i was a
postdoc because he always talks about
how you know whether aliens are common
or rare is kind of just um you know it's
like you know it follows a wave of
popularity and it just depends on like
the mood of you know what the culture is
at the time and i always thought that
was kind of an intriguing observation
but but also there's this you know set
of points about if you go by
observational evidence which we're
supposed to do with scientists right um
you know
we have evidence of
us
and one original life event from which
we emerged and people want to make
arguments that because that event was
rapid
or because there's other planets that
have properties similar to ours that
that event should be common but you
actually can't reason on that because
our existence observing that event is
contingent on that event happening which
means it could have been completely
improbable or very common
and brandon carter like clearly
articulated that in terms of anthropic
arguments um
a few decades ago so so there is this
kind of issue that we have to contend
with dealing with life that's closer to
home than we have to deal with with any
other problems in physics which we're
talking about the physics of ourselves
and when you're asked about the original
life event that event happening in the
universe at least is like our existence
is contingent on it um and so you can
think about sort of fine tuning
arguments um
that way too so um but the the sort of
odder part of it is like when i think
about
uh how likely it is i think it's because
we don't understand this mechanism yet
about
how information can be generated
spontaneously
that i like because i can't see that
physics clearly yet even though i have a
lot of
you know like some things around the
space of it in my mind i can't
articulate how likely that process is
um so my honest answer is i don't know
and it sometimes feels like a cop-out
but i feel like that's a more honest
answer and a more meaningful way of
making progress than um what a lot of
people want to do which is say oh well
we have a one-in-ten chance of having on
an exoplanet with earth-like properties
because there's lots of earth-like
planets out there and life happen fast
on earth well so
i have kind of a follow-up question but
as a side comment
what i really am enjoying about the way
you're talking about human beings is you
always say not to make yourself
conscious about it because i really
really enjoy it do you say we
yes you don't say humans
you say because often times like and you
know i don't know evolutionary
biologists will kind of
put yourself out
yes as an observer but you're
it's it's kind of fascinating to think
that you as a human are struggling about
your own origins
yes that's the problem and yeah and i i
think um i don't do that deliberately
but i do think that way and this is sort
of the inversion from the logic of
physics because physics as it's always
been constructed has treated us as
external observers of the universe and
we are not part of the universe and this
is why the problem of life i think
demands completely new thinking because
we have to think about ourselves as
minds that exist in the universe and are
at this particular moment in history and
looking out at the things around us and
trying to understand what we are inside
the system not outside the system we
don't have descriptions at a fundamental
level that describe us as inside the
system and this was my problem with
cellular automata also you're always an
external observer for a cellular
automata you're not in the system what
does the cellular automata look like
from the inside
i think you just broke my brain with
that question exactly but i thought
about that for a long time
i'm gonna
uh yeah that's a that's a really clean
formulation of a very fundamental
question because you can only to
understand cellular autonomy you have to
be inside of it
but as a human sort of a poetic romantic
question does it make you sad does it
make you
hopeful
whether we're alone or not like in the
different possible versions of that
if we're the highest assembly object in
the entire universe
does that at this moment in time at this
moment in the causality because we might
i assume we have a future well we
definitely have a future and the
question is well yeah where that future
decreases the assembly like it could be
where at the peak
or we could be just um
that would be inconsistent with the
physics in my mind but
so so i i should give a caveat i've
given the the caveat that i'm biased as
a physicist but i'm also biased as an
eternal optimist so pretty much all of
my modes of operation for building
theories about the world are not like an
occam's razor what's the simplest
explanation but what's the most
optimistic explanation
and part of the reason for that is if
you really think explanations have
causal power
um in the sense that our theo like the
fact that we have theories about the
world has enabled technologies and
physically transformed the world around
us i think i have to take seriously that
as a part of the physics i want to
describe
and try to
build
theories of reality that are optimistic
about what's coming next because the
theories are in part the causes of what
comes next
so there could be a physics of
hope or physics of optimism in there too
yes
because um
that seems like also i mean optimism
does seem to be a kind of engine that
results in innovation yes so this is dr
like what why the hell
are we trying to come up with new stuff
oh so um so i made this point about
thinking life is the physics of
existence and it's not just the physics
of existence it's the physics of
more things existing
so i think one of these drives
the yeah creativity like optimism the
story so if you like people like entropy
i don't i don't like entropy as it was
formulated in the 1800s i think it's an
antiquated concept but um but this idea
of maximizing over the possible number
of states that could exist imagine the
universe is actually trying to maximize
over the number of things that could
physically exist what would be the best
way to do that the best way to do that
would be evolve intelligent
technological things that could explore
that space
so okay that's talking about alien life
out there in the universe but you've
also earlier in the conversation
mentioned
the shadow biosphere so is it possible
that we have weird life here
on earth that we're just not
like even in a high assembly formulation
of life yeah that we're just not
paying attention to we're blind to like
life we're potentially able to detect
but we're blind to and maybe you could
say what is the shadow bias sure sure
yeah the shadow biosphere is this idea
that there might have been other
original life events that happened on
earth
that were independent from the original
life event that led to us and all of the
life that we know on earth and therefore
there could be aliens in the sense they
have a different origin event
living among us um uh and it was
proposed by a number of people um
but one of them was a paul davies that i
mentioned earlier as my mentor and he
has a really a cute way of saying that
aliens could be right under our noses or
even in our noses
uh with a british accent it sounds
better but um but uh but anyway so the
idea is like it could literally be
anywhere around us um and if you think
actually about the discovery of like
viruses and bacteria you know for a long
time we didn't they were kind of a
shadow biosphere it was life that was
around us but invisible
um and
but this takes it a little bit further
in saying that you know all of those
examples viruses bacteria and everything
that we've discovered so far has this
common ancestry in the last universal
common ancestor of life on earth so
maybe there was a different origin event
and that life is weirder still
and might be among us and we could find
it
we don't have to go out and stars live
for aliens just here on earth do you
think that's a serious
possibility that we should explore with
the tools of science like this should be
a serious effort i think um yes and no
um and
i mean yes because i think it's a
serious hypothesis um and i think it's
worth exploring and it is certainly more
economical to look for
signs of alien life on earth than it is
to go and build spacecraft and send
robots to other planets and that was one
of the reasons it was proposed is well
if we do find an example of another
original life on earth it's hugely
informative because it means the
original life is not a rare event if it
happened
twice on the same planet that means it's
probably pretty probable given
conditions are right
um so it has huge potential scientific
impact not to mention the fact that you
might have like biochemistry and stuff
that's informative for like medicine and
stuff like that but
um
but i think that the thing for me that's
challenging about it and this really
comes from my own work like thinking
about
life as a planetary scale process and
also trying to understand
sometimes what i call like the
statistical mechanics of biochemistry
but large scale statistical patterns in
the chemistry that life uses on earth
there are a lot of regularities there
and life does seem to have planetary
scale organization that's consistent
even with some of the patterns that we
see at the individual scale so if you
think life is a planetary scale
phenomena and the chemistry of life has
to be sort of
um
not just it's not an individual is not
necessarily the fundamental unit of life
right the fundamental you know life is
these uh informational lineages and
they're kind of you know they intersect
over
spatial scales so everything on earth is
kind of related by the common causal
history yeah so it's hard for me
based on the way i think about the
physics and also some of the stuff that
my group has done to really think that
there could be
uh evidence or there could be a second
sample of life on earth but i think
there are ways that we need to be more
concrete about that and i have thought a
little bit about like um you know like
you can represent the chemistry in an
individual cell as a network and then
those networks something my group has
shown
actually scale
with the same properties so ecosystems
have the same properties as individuals
as planetary scale and then you could
imagine if you had alien chemistry
intermixed in there that scaling would
be broken so if there's some robustness
property or something associated to it
and you get alien chemistry in there it
just breaks everything and you don't
have a planetary ecosystem functioning
an individual's functioning across all
these scales so i guess what i'm arguing
is life is not a scale-dependent
phenomena it's not just cellular life so
if you have a shadow biosphere it has to
be integrated with all of these other
scales in it and that and that would
lose the meaning of the word shadow
biosphere i think so yeah so so i i it's
an open question right and i think it
would it would tell us a lot so there
has been very minimal effort of people
to look for a shadow biosphere
but then the question it could be
possible that uh
there's like sufficiently distinct
planets within one planet meaning like
environments within one planet yeah like
i don't know
i've been looking uh recently
uh because of having a chat with
catherine declare about io the moon of
jupiter that's like all volcanoes and
volcanoes a badass but like yeah
imagining
[Laughter]
imagining life inside volcanoes right
like yeah it seems like sufficiently
chemically
different
like to be living in the darkness right
where there's a lot of heat and maybe
you could have different earths on like
a planet yeah or like if you go deep
enough in the crust maybe there's like a
layer where there's no life and then
there's suddenly life again and maybe
those you know lizard
men or whatever that people dream about
are really down there um i know that's a
little flippant but but really like
there could be like chemical cycles deep
in those crests that might be alive and
are completely distinct in chemical or
origin to surface life
right that they wouldn't be interacting
with each other yeah and that's one of
the proposals for the shadow biosphere
is like sometimes people talk about it
as being geologically or geographically
distinct that it might be you know you
have no life for this region and then a
different example and then sometimes
people talk about it being chemically
distinct that the chemistry is
sufficiently different that it's
completely orthogonal or non-interacting
with our chemistry it seems to me at
least the chemistry is
a a more powerful
boundary yes than than than geographic
it just seems like life
finds a way literally to travel yeah
yes
what do you think about all these ufo
sightings so to me it's really inspiring
it's yet another
localized way to dream about right the
mysterious that is out there yeah
so i've actually been more intrigued by
the cultural phenomena ufos than the
phenomena ufos themselves because i
think it's intriguing about how
uh
we are preparing ourselves mentally
for understanding others and how we have
thought about that historically and what
the sort of
modern incarnations of that are um
it's more like
i want an explanation for us that's my
motivation and having some you know
streaks across the sky or something and
saying that's aliens it doesn't tell you
anything
um so unless you have a deeper
explanation and you have you know more
lines of
uh you know where is this going to take
us in the future it's just not as
interesting to me as the problem of
understanding life itself and aliens as
a more general phenomenon i do think
it's uh just as you said
a good way to psychologically and
sociologically prepare ourselves to sort
of like what would that look like right
and very importantly which is what a lot
of people talk about politically
sort of uh there's this idea from the so
it came from the soviet union of like
the cold war and we have to hide secrets
yeah there's some way in us searching
for life on other planets are searching
for life in general
the
the way we've done government in the
past yeah we tend to think of all new
things as potential military secrets so
we want to hide them
and one of the ways that people kind of
look at ufo sightings is like
like maybe we shouldn't hide this stuff
like what is the government hiding right
i think that's a really
you know in one sense it's a
conspiratorial question but i think
in another it's an
inspiration to change the way we do
government to where secrets don't uh
maybe there are times when you want to
keep secrets as military secrets but
maybe we need to release a lot more
stuff and see us as a human species as
together in this whole search yeah the
public engagement part there is really
interesting
and it's almost like a challenge to the
way we've done stuff in the past in
terms of keeping secrets when they're
not so like
the the first step if you don't know how
something how something works if there's
a mysterious thing the the first
instinct should not be like let's hide
it put it in the closet right so that
the chinese or the russian government or
whatever government doesn't uh doesn't
find it maybe the first one the first
instinct should be let's understand it
yeah perhaps let's understand it
together right
no i think that's good and and something
i realized recently that i never thought
was going to be a problem but i think
this actually helps with quite a bit
is because so many um people nowadays
believe we've already made contact
that
as an astrobiologist if we you know
actually want to understand life and
make contact we kind of have to
deconstruct
the narratives we've already built from
ourselves and kind of unteach ourselves
that we've learned about aliens and then
reteach ourselves so there's this really
interesting sort of dialogue there um
and making it open to the public that
they actually have to think critically
about it and they see the evidence for
themselves i think is really important
for that process
yeah the restriction that aliens might
be way weirder than we can imagine yes
yes i'm i'm pretty sure they're probably
weirder than we can imagine
okay we've uh in 2020
and still living through a pandemic
setting the the the the political and
all those kinds of things aside i've
always found
viruses fascinating
as as living
as
dynamical systems i was going to say
living systems but
i've always kind of thought of them as
living you know but that's a whole
nother kind of discussion maybe
it'd be great to put that on the table
one do you find viruses
beautiful slash terrifying and two do
you think they're living
things
or there's some aspect to them
for our discussion of life that makes
them living
i mean living in a pandemic saying
viruses are beautiful is probably a hard
thing but i do find them
beautiful to a degree i think
even even even in the sense of mediating
a global pandemic there's something like
deeply intriguing there because
you know these these are tiny
tiny little things right and yet they
can um
uh you know essentially um
like cause a seizure like you know
handicap an entire civilization at a
global scale so just that intersection
of between you know our perceived
invincibility and our susceptibility to
things and also the interaction across
scales of those things is just
a really amazing feature of our world
most technology whether it's viruses or
ai
that can scale scale in an exponential
way like right kind of run
you know like
as opposed to like one thing makes
another thing
makes another thing it's one thing makes
two things and those two things make
four things and then like that kind of
process
also seems to be fundamental to life yes
and uh
it's terrifying because in in a matter
of in a very short time scale
it can uh
if it's good at being life
whatever that is yeah it can quickly
overtake the the other competing forms
of life right
and that's scary both for ai and
for viruses and it seems like
understanding these processes
that are underlying viruses and i don't
mean like on the virology or biology
side but on some kind of
more computational physics yeah
perspective as we've been talking about
yeah seems to be really important to
figure out how humans can
survive
right
along with these kinds of
this kind of life and perhaps becoming a
multi-planetary species is
is a part of that like there's no maybe
like what we'll figure out from a
physics perspective is like there's no
way
any living system
can be stable for a prolonged period of
time and survive unless it expands
exponentially throughout like
we have to multiply otherwise
anything that doesn't multiply
exponentially will die eventually maybe
that's a fundamental law
um
maybe
i don't know i you know i always get
really bothered by these darwinian
narratives that are like you know like
the fittest replicator wins and things
and i don't i just don't feel like
that's exact exactly what's going on i
think like the copying of information is
sort of
ancillary to this other process of
creativity
right so like the drive is actually the
drive is creativity but if you want to
keep the creativity that's existed in
the past it has to be copied into the
future
right so replication like if you
so that for me is
so i had this set of arguments um with
michael lachman and lee cronin about the
like life being about persistence they
thought it was about persistence and
like survival of fittest kind of thing
and i'm like no it's about existence
it's like because when you're talking
about that it's easy to say that in
retrospect you can post select on the
things that survived and then say why
they survived
but um but you can't do that going
forward
that's really profound
that survival is just a nice little
side effect feature of
maximizing creativity but it doesn't
need to be there yeah
i like people yeah yeah like i said i
like optimistic theories well i don't
know if that's up to me that that could
be terrifying to people because
yeah because uh you know a system that
maximizes creativity may very quickly
get rid of humans for some reason if it
comes up with some other creative
i mean yeah
forms of existence
yeah right this is the ai thing it's
like the moment you have an ai
system that can
that can flourish in the space of ideas
or in some other space much more
effectively than humans
and it's sufficiently integrated into
into the physical space to be able to
modify the environment
i think we'll just be like the core
genetic architecture or something we'll
be like the dna for ai right it's like
we haven't lost the past informational
architectures on this planet they're
still there
yeah also they'll ai will use our brains
in some part to like like ride like
it'll accelerate the exchange of ideas
that's the neural link dream is that
well the humans will be still around
because you're saying architecture yeah
but i don't i don't even think they
necessarily need to tap in our brains i
mean just collectively we do interesting
things what if they were just using like
the patterns in our communication or
something
oh
without controlling it just
observing well i i don't know in what
sense do you control the chemistry
happening in your body
hmm
yeah
i i mean i i obviously i don't know i'm
just i i just
like the way i look at like people look
at ai and then they look at this thing
that's bigger than us and is coming in
the future and is smarter than us
and i think though that looking at the
past history of life on the planet and
what information has been doing for the
last four billion years is probably very
informative to asking questions about
what's coming next
um
and i don't
one is planetary scale transitions are
really important for new phases so the
global internet and sort of global
integration of our technology i think
it's an important thing so that's again
life is a planetary scale phenomena but
we're an integrated component of that
phenomenon i don't really see that the
technology is going to replace us
in that way it's just going to keep
scaffolding
and building and and i also don't have
an idea that we're going to build ai in
a box i think ai is going to emerge agi
to be is a planetary scale phenomena
that's going to emerge from our
technology
planetary scale phenomena but do you
think
an agi is not distinct from humans we're
the whole package the whole package
comes as a planetary scale phenomenon
and that goes back to the fact that like
you were you know asking questions about
you as an individual
like what are you as an individual
you're like a packet of information that
exists in the particular physical thing
that is you we're all just
packets of information and some of us
are aggregates in certain ways but it's
all just kind of exchanging and
propagating right and processing
is your
packet of information that you've
continually referred to as sarah
afraid
of the dissipation of the
death of that packet are you afraid of
death
do you ponder death
does death have meaning in this process
of creativity i think i have the natural
biological urge that everyone has to
fear death
um
i think the thing that i think is
interesting is if i think about it
rationally
i'm not necessarily afraid of death for
me because i won't be aware of being
dead
um but i am afraid like for my kids
because it matters to them if i die
um so
so again like i think death becomes more
significant as a collective property not
as an individual one
yeah but isn't there something to fear
about
the fact that the way
like
the creative uh
the complexity of information that's
been like created in you yeah the the
fact that it kind of
breaks apart
and disappears
it doesn't but i don't think it
disappears it's just not me anymore
right so you're but the that process of
you it being not you anymore that
doesn't scare you
of course it does the mystery of it i
mean the yeah but i guess i'm heartened
by the fact that there will be some
imprints of the fact that i existed
still in the universe after i leave it
yeah but there'll be a okay and also
that has to do with my perception of
time right so you know i perceive time
as flowing but that might not be the
case
i mean this is you know standard
physicists comfort is you know every
time moment exists you know and is you
know there's no and the flow of time is
just our perception of
you know us um you know us changing
um
so you can travel back in time and
that's comforting like from a physics
condition no no i'm not talking about
traveling back in time i'm just saying
that the moments in the past still exist
um now whether the moments in the future
exist or not is a different question
that's not comforting to me in terms of
death
the flow of time is not that does not i
think uh i think it's i think there's no
comfort in the face of death for what we
are uh
because we like existing and i think
it's especially true if you if you love
life
and you love what life is
do you think there's a certain sense in
which
the fear of death or the fear of
non-existence maybe fear is not the
right word
is the actual very phenomena that gives
birth to existence like maybe death is
fundamental like this it just feels like
freaking out oh
this ride ends
is actually like
the
that's
that's the thing that gives birth to
this this whole thing yeah that like
it's constantly
is matter constantly freaking out about
the fact that it's good enough no i
think i think things like to exist i
think they want to exist yeah there's a
there's a desire whatever to exist yeah
and there's a drive to exist and there's
a drive for more things to exist i guess
um yeah i would like to i like existing
i like i like i like it a lot um
and i don't know it any other way
but see i don't even know if i like
existing i think i really don't like not
existing yes yeah that's you
uh yeah
yeah maybe it's that i
some days i you know i might like
existing less than others but
yes but like i think those are like
surface feelings there is yeah it seems
like there's something fundamental about
wanting to exist no i think that's right
but i
but i think
to your point that that might go back to
the more fundamental
idea that you know if life is the
physics of existence and maximizing
existence individual organisms of course
want to maximize their existence
and everything you know like wants to
exist but i guess for me the small
comfort is
my existence matters to future existence
speaking of future existence is there
advice you can give to future pockets of
existences
aka young people
about life you've had uh
you've worn many hats you've taken on
some of the biggest problems in the
universe is there advice you can give to
young people about life about career
about existing
uh maybe not about the last one
um you know a lot of people ask me this
question about like like working on such
hard problems like how can you make a
successful career out of that but i
think for me
it couldn't be otherwise like i have to
to be fulfilled you have to work on
things you care about and that's always
kind of driven me and that's been
disciplined department
um
uh
and sort of superficial level problem
independent because i'm i
i started at community college actually
and i was taking a physics class and i
learned about
uh you know magnetic monopoles and they
we didn't know if they existed in the
universe and but we could predict them
and we could go look for them and i was
so deeply intrigued by this idea that we
had this mathematical formula to go look
for things
and then i wanted to become a
theoretical physicist because of that
but that actually wasn't my driving
question i realized my driving question
is
the nature of the correspondence between
our minds and physical reality and what
we are
and
that question's very deep so you can
work across a lot of fields doing that
but i think without that driving
question i never would have been able to
do all the things that i've done it's
really the passion that drives it and i
and usually when when students ask me
these kind of questions i i tell them
like you have to find something you
really care about working on because if
you don't really care about it a you're
not going to be your best at it
and b it's not going to be worth your
time why would you spend your time
working on something you're not
interested in so find the driving
questions yeah find the driving question
find your your passion i mean i think
passion makes a huge difference in terms
of creativity
talent and potential and also being able
to tolerate all the hard things that
come with any career or life
yeah i've had a bunch of moments in my
life where i've just been captivated by
some beautiful phenomena and i guess
being rigorous about it and asking what
is the question underlying this
phenomenon phenomena like
robots bring a smile to my face and yeah
that's cool forming a
question of like why the hell is this so
fascinating yeah why is this uh
specifically the human robot
interaction question that's something
beautiful
is brought to life when humans and
robots interact
understanding that deeply yeah
it's like okay so this is going to be my
life work then i don't know what the
hell it is but that that's what i want
to do
interesting and doing that doing that
for whatever the hell gives you that
kind of feeling i guess is the point
yeah
am i allowed to ask you a question sure
okay um
on that point because i like um at this
colleague that suggests the idea that
like consciousness might be contagious
and so interacting with things you know
isn't it no yeah it's an interesting
idea right so i'm i'm wondering like
sort of
you know the motivation there is it the
motivation that you want
more of the universe
to appreciate
things the way we do and appreciate
those interactions or is it really more
the enjoyment of the human in those
interactions like is it
is it
i don't do you know what i'm asking yeah
yeah see i think consciousness is
created in the interaction between
yes things yes
so the joy is in the creation of
consciousness and i see i really
like the idea that
it doesn't
just have to be two humans creating
costumes together it could be
humans and other entities yeah we talked
offline about dogs and other pets and so
on there's a magic i mean i've been
calling it
love is
this beauty of the human experience
that's created and it just feels like
fascinating that you could do that
with a robotic system right and
right there's something really powerful
at least to me about
engineering systems that allow you to
create some of the magic of the human
experience because then you get to
understand
what it takes at least get inklings of
what it takes to uh
to to create consciousness and i i don't
get this um
you know philosophers get really upset
about this idea that sort of
the illusion of consciousness is
consciousness but
i really like the idea of engineering
systems that fool you
into thinking they're conscious right
because that's sufficient to create the
magical experience right because it's
the interaction yeah it's the
interaction yeah right and this is the
russian head i wear which is like i
think
i think there's an ocean of loneliness
in the world i think we're deeply lonely
we're not even allowing ourselves to
acknowledge that and i kind of think
that's what love is between romantic
love and friendship
is two people kind of getting a little
bit
like
like uh alleviating for a brief moment
that loneliness that loneliness but not
but we're not they're it's not the full
aspect of that loneliness like we're
desperately alone we're desperately
afraid of not existing right i have that
kind of sense and i just want to explore
that ocean of loneliness more right
like create a submarine that goes into
the depth of that loneliness
so creating systems that can truly hear
you right truly listen make the universe
a less lonely place exactly uh let me
ask you about uh the meaning you've
brought up why yeah the physics of why
what do you think is the meaning of our
particular
planets
set of existences and uh the universe in
general
um the meaning of life yes someone once
told me as a physicist i'm not allowed
to ask why questions but i don't believe
that so
um
i think
what we are is
the creative process in the universe i
think and i for me that's the meaning
um the ability to yeah to create
more possibilities and more things to
exist
how what what is uh
dostoevsky has the saying beauty will
save the the world
what is uh is there a connection between
creation and beauty
i think so
so is that like
are they is his beauty a correlate of
creation it might be i don't know um i
mean why is it i you know
a lot of people have asked these kind of
questions but like why is it we have
such an emotional response to
intellectual activity or creativity
um and that seems kind of a deep
question to me like it seems very
intrinsic to
what we are so i
i do
have an interest in the questions i ask
because i think they're beautiful and i
think the universe is beautiful and
um i'm just so deeply fascinated by the
fact that i exist at all
um
and so maybe maybe it's that
you know that that intrinsic feeling of
beauty that's in part driving you know
the physics of creating more things so
they could be deeply related in that way
well i don't think there's a better way
to end it i think this conversation was
beautiful thank you so much for uh
wasting all your valuable time with me
today i really really appreciated sarah
this is an honor i hope we get a chance
to talk again i hope uh like i mentioned
to you offline we get a chance to talk
with lee you guys have a beautiful um
like intellectual chemistry that's
fascinating to listen to so i'm a huge
fan of both of you and i can't wait to
see what you do next thanks so much
great to be here
thanks for listening to this
conversation with sarah walker and thank
you to athletic greens nut sweet
blinkist and magic spoon
check them out in the description to
support this podcast
and now let me leave you with some words
from robert frost one of my favorite
poets
in three words i can sum up everything
i've learned about life
it goes on thank you for listening i
hope to see you next time