Kind: captions
Language: en
I think it's actually not that hard to
imagine we are the only civilization in
the Galaxy right now living yeah that's
that's currently extent but there may be
very many extinct civilizations if each
civilization has a typical lifetime
comparable to let's say AI is the demise
of our own that's only a few hundred
years of technological development or
maybe 10,000 years if you get back to
the neic re Revolution the dawn of
Agriculture you know hardly anything in
Cosmic time span um that that's nothing
that's the blink of an eye and so it's
not surprising at all that we would
happen not to coexist with anyone else
but that doesn't mean nobody else was
ever here and if other civilizations
come to that same conclusion and
realization maybe they scour the Galaxy
around them they find any evidence for
intelligence then they have two options
they can either give up on communication
and just say well it's never going to
happen uh we just may as well just you
know worry about what's Happening Here
on their own planet or they could
attempt communication but communication
through
time the following is a conversation
with David Kipping an astronomer and
astrophysicist at Columbia University
director of the cool worlds lab and he's
an amazing educator about the most
fascinating scientific phenomena in our
universe I highly recommend you check
out his videos on the Cool World's
YouTube channel David quickly became one
of my favorite human beings I hope to
talk to him uh many more times in the
future this is Alex Reedman podcast to
support it please check out our sponsors
in the description and now dear friends
here's David
Kipping your research at Colombia is in
part focused on what you call cool
worlds or worlds outside our solar
system where temperature is sufficiently
cool to allow for moons rings and Life
to form and for us humans to observe it
so can you tell me more about this idea
this place of cool world
yeah the history of discovering planets
outside our solar system was really
dominated by these hot planets and
that's just because of the fact they're
easier to find when the very first
methods came online these were primarily
the Doppler spectroscopy method looking
for wobbling stars um and also the
transit method and these two both have a
really strong bias towards finding these
hot planets now hot planets are
interesting the chemistry in their
atmosphere is fascinating it's very
alien um an example of one that's
particularly close to my heart is tra 2B
whose atmosphere is so dark it's less
reflective than coal and so they have
really bizarre photometric properties
yet at the same time they resemble
nothing like our own home and so it said
there two types of astrophysicists the
astrophysicist who care about how the
universe works they want to understand
the mechanics of the Machinery of this
universe why did the big bang happen why
is the universe expanding how are
galaxies formed and there's another type
of astrophysicist which perhaps um
speaks to me a little bit more it
Whispers into your ear and that is why
are we here are we alone are there
others out there and ultimately along
this journey the hot plants aren't going
to get us there we when we're looking
for life in the universe seems to make
perfect sense that there should be plets
like our own out there maybe even moons
like our own planet around gas giants
that could be habitable and so my
research has been driven by trying to
find these more tulous globes that might
resemble our own Planet so they're the
ones that lurk more in the shadows in
terms of how difficult it is to detect
they're much harder they're harder for
several reasons the method we primarily
use is the transit method so this is
really eclipses as the planet passes in
front of the star it blocks out some
Starlight the problem with that is that
not all planets pass in front of their
star they have to be aligned correctly
from your line of sight and so the
further away the planet is from the Star
the cooler is the less likely it is that
you're going to get that geometric
alignment so whereas a hot Jupiter about
1% of hot Jupiter's will transit in
front of their star only about uh 05%
maybe even a quarter of a percent of
earthlike planets will have the right
geometry to Transit and so that makes it
much much harder for us what's the
connection between temperature of the
planet and geometric alignment
probability of geometric alignment
there's not a direct connection but
they're connected by an intermediate
parameter which is their separation from
the Star so
the planet will be cool if it's further
away from the Star which in turn means
the probability of getting that
alignment correct is going to be less on
top of that they also Transit their star
less frequently so if you go to the
telescope and you want to discover a hot
Jupiter you could probably do in a week
or so because the orbital periods of
order of one 2 3 days so you can
actually get the full orbit two or three
times over whereas if you wanted to set
an earthlike Planet you have to observe
that star for 3 four years and that's
actually one of the problems with Kepler
Kepler was this very successful mission
that NASA launched um over a decade ago
now I think and it discovered thousands
of planets it's still the dominant
source of exoplanets that we know about
but unfortunately it didn't last as long
as we would have liked it to it died
after about 4.35 years I think it was
and so for an earthlike Planet that's
just enough to catch four transits and
four transits was kind of seen as the
minimum but of course the more transits
you see the easier it is to detect it
cuz you build up signal to noise if you
see the same thing tick ti ti tick the
more ticks you get the easier is to find
it and so it was really a shame that
Kepler was just at the limit of where we
were expecting it to start to see
earthlike planets and in fact it really
found zero zero planets that are around
stars like the sun are orbit similar to
the Earth around the Sun and could
potentially be similar to our own planet
in terms of its composition and so it's
a great shame but um that's why it gives
a strong is more to do in the future
just to clarify the transit method mhm
is our primary way of detecting these
things and what it is is um when the
object passes udes the source of light
just a tiny bit a few pixels and from
that we can infer something about its
mass and size and distance and geometry
all all of that that's like trying to
tell what uh
at a party you can't see anything about
a person but you can just see by the way
they include others so this is the
method but is this a super far away how
many pixels of information do we have
basically how high resolution is the
signal that we um that we can get about
these
occlusions you're right in your
description I I think just to build upon
that a little bit more it might be
almost like your vision is completely
blurry like you have an extreme you know
H prescription and so you can't resolve
anything everything's just blurs and but
you can tell that something was there
because it just got fainter for a short
amount of time something someone passed
in front of a light and so that light in
your eyes would just dim for a short
moment now the reason we have that
problem with bless or resolution is just
because the stars are so far away I mean
these are the closest stars are four
light years away but most of the Stars
kept looked at were thousands of light
years away and so you there's absolutely
no chance that the telescope can
physically resolve the star or even the
separation between the planet and the
star is is too small especially for a
telescope like Kepler it's only a meter
across in principle you can make those
detections but you need a different kind
of telescope we call that direct Imaging
and direct Imaging is a very exciting
distinct way of detecting planets but it
as you can imagine is going to be far
easier to detect planets which are
really far away from their star to do
that because that's going to make that
separation really big and then you also
want the star to be really close to it
so the nearest Stars not only that but
you would prefer that planet to be
really hot because the hotter it is the
brighter it is and so that tends to bias
direct Imaging towards plants which are
in the process of forming so things
which have just formed the planet still
got all of its primodial heat embedded
within it and it's glowing we can see
those quite easily but for the planets
more like the Earth of course they've
cooled down and so we can't see that the
light is pitiful compared to a newly
formed planet we would like to get there
with direct Imaging that's the dream is
to have the pale blue dot an actual
photograph of it maybe even just a one
pixel photograph of it but for now the
entire solar system is one pixel with
certainly with Transit method most other
telescopes and so all you can do is see
where that one pixel which contains
potentially dozens of planets and the
star maybe even multiple Stars dims for
a short amount of time it dims just a
little bit and from that you can infer
something yeah I mean it's it's like
being a detective in the scene right
it's very it's indirect clues of the
existence of the planet it's amazing
that humans can do that we're just
looking out in these immense
distances and looking you know if
there's alien civilizations out there
like let's say one exactly like our
own we like would we even be able to see
an earth that passes mhm in the way of
its sun and slightly dims and that's the
only sign we have of that of that alien
humanlike civilization out there is it's
just a little bit of a dimming
yeah I mean depends on on the type of
star we're talking about if it is a star
truly like the sun the dip that that
causes is 84 parts per million I mean
that's just it's like the same as a um
as like a firefly flying in front of
like a giant flood light at a stadium or
something that's the kind of the
brightness contrast that you're trying
to compare to so it's it's extremely
difficult detection and in the very very
best cases we can get down to that but
as I said we don't really have any true
Earth analoges that have been in the
exlan candidate yet unless you relax
that definition you say it's not just
doesn't have to be a star just like the
sun it could be a star that's smaller
than the sun it could be these orange
dwarfs or even the red dwarf stars and
the fact those stars are smaller means
that for the same size Planet passing in
front of it more light is blocked out
and so a very exciting system for
example is trapis one which has seven
plets which are smaller than the earth
and those are quite easily detectable
not with a space-based telescope even
from the ground and that's just cuz the
star is so much smaller that the
relative increase in or decrease in
brightness is enhanced significantly cuz
that smaller size so trapis 1e it's a
planet which is in the right distance
for liquid water it has a slightly
smaller size on the earth um it's about
90% the size of the Earth about 80% the
mass and it's one of the top targets
right now for potentially having life um
and yet it raises many questions about
um what would that environment be like
this is a star which is 1/8 the mass of
the sun it's um stars like that take a
long time to come off their adolescence
when stars first form like the sun it
takes them maybe 10 100 million years to
sort of settle in to that main sequence
lifetime but for stars like these late M
dwarfs as we call them they can take up
to a billion years or more to calm down
and during that period they're producing
huge amounts of x-rays ultraviolet
radiation that could potent rip off the
entire atmosphere it may desiccate the
plants in the system and so even if
water arrived by comets or something it
may have lost all that water due to this
prolonged period of high activity so we
have lots of open-ended questions about
these M dwarf planets but they are the
most accessible and so in the near term
if we detect anything in terms of Bio
signatures it's going to be for one of
these red dwarf stars it's not going to
be a true Earth twin as we would
recognize it as having a yellow star
well let me ask you I mean there's a
million ways to ask this question I'm
sure I'll ask it about habitable
worlds let's just go to our our own
solar system what can we learn about the
planets and
moons in our solar system
that might contain life whether it's
Mars or some of the moons of Jupiter and
Saturn what kind of characteristics cuz
you said it might not need to be
earthlike what kind of characteristics
might we we' be looking for when we look
for life it's hard to Define even what
life is um but we can maybe do a better
job in defining the sorts of things that
life does and that provides um some
aspects to some Avenue for looking for
them um in the classically
conventionally I think we thought the
way to look for life was to look for
oxygen oxygen is a byproduct of
photosynthesis on this planet um we
didn't always have it certainly if you
go back to the Aran period um there was
you know you have this period called the
Great oxidation event where the Earth
floods with oxygen for the first time
and starts to saturate the oceans and
then into the atmosphere and so that
oxygen if we detect it on another planet
whether it be Mars Venus or an exoplanet
whatever it is um that was long thought
to be evidence for something doing
photosynthesis because if you took away
all the plant life on the earth the
oxygen would just hang around here as a
highly reactive molecule it would
oxidize things and So within about m
milon years you would probably lose all
the oxygen on planet Earth so that was a
conventionally how we thought we could
look for life and then we started to
realize that it's not so simple because
a there might be other things that life
does apart from photosynthesis um
certainly the vast majority of the
Earth's history had no oxygen and yet
there was living things on it so that
doesn't seem like a complete test um and
secondly could there be other things
that produce oxygen besides from Life um
a growing concern has been these false
positives in by signature work and so
one example of that would be photolysis
that happens in the atmosphere when
ultraviolet right hits the upper
atmosphere it can break up water vapor
the hydrogen splits off to the oxygen
the hydrogen is a much lighter Atomic
species and so it can actually Escape
certainly plets like the Earth's gravity
that's why we don't have any hydrogen or
very little helium and so that leaves
you with the oxygen which then oxidizes
the surface and so um there could be a
residual oxygen signature just due to
this fotsis process so we've been trying
to generalize and um certainly recent
years there's been other suggestions of
things we could look for in the solar
system Beyond uh nitrous oxide basically
laughing gas is a product of microbes um
that's something that we're starting to
get more interested in looking for
methane gas in combination with other
gases can be an important bio signature
uh phosphine as well and phosphine is
particularly relevant to the solar
system because there was a lot of
interest for Venus recently um you may
have heard that there was a claim of a
bio signature in Venus's atmosphere I
think it was like two years ago now and
the the judge and jury is still out on
that um there was a very provocative
claim and signature of a phosphine like
spectral
absorption um but it could have also
have been some of molecule in particular
sulfur dioxide which is not a bio
signature so this is a detection of a
gas in the atmosphere Venus and and uh
it might be controversial on several
Dimensions so one how to interpret that
two is just thr gas and three is this
even the right detection is this is
there an error in the detection yeah I
mean how much do we believe the
detection in the first place if you do
believe it does that necessarily mean
there's life there and um what gives how
can you have life in the Venus's
atmosphere in the first place because
that's you know been seen as like a hell
hole place for imagining life but I
guess the the the counter that has been
that okay yes the surface is a
horrendous place to imagine life
thriving um but as you go up in altitude
the very dense atmosphere means that
there is a cloud layer um where the
temperature and the pressure become
actually fairly similar to the surface
of the Earth and so maybe there are
microbes stirring around in the clouds
which are producing phosphine um at the
moment this is fascinating it's got a
lot of us reinvigorated about the
prospects of going back to Venus and
doing another Miss Mission there in fact
there's now two NASA missions Veritas
and da Vinci which are going to be going
back in before 2030 or the
2030s um and then we have a European
Mission I think that's slated now and
even a Chinese Mission might be coming
along the way as well so we might have
multiple missions going to Venus which
has long been overlooked I mean apart
from the Soviets there really has been
very little in the way of exploration of
Venus as certainly as compared to Mars
Mars has enjoyed most of the activity
from NASA's Rovers and surveys
um and Mars is certainly fascinating
there's you know this signature of
methane that has been seen there before
um again there the discussion is whether
that methane is a product of biology
which is possible something that happens
on the earth or whether it's some
geological process that we are yet to
fully understand could be you know for
example a reservoir of methane that's
trapped under the surface and it's
leaking out seasonally so the nice thing
about Venus is if there is a giant
living civiliz there it'll be airborne
so you can just fly through and collect
samples yeah with Mars and uh moons of
uh Saturn and Jupiter you're going to
have to dig dig under to find the
civilizations dead or living right and
so yeah maybe it's easier than for Venus
because certainly you can imagine just a
balloon floating through the atmosphere
um that or a drone or something that
would have the capability of just
scooping up and sampling um to to dig
under the surface of Mars is
maybe feasible is with you know
especially with something like Starship
that could launch you know a huge Digger
basically to the surface and you could
just excavate away at the surface but
for something like Europa um we really
are still unclear about how thick the
ice layer is um how you would melt
through that huge thick layer to get to
the ocean and then potentially also
discussions about contamination the
problem with looking for life in the
solar system which is different from
looking for life with exoplanets is that
you always run the risk of especially if
you visit there of introducing the life
yourself right it's very difficult to
completely exterminate every single
microbe and Spore on the surface of your
of your Rover or the surface of your
Lander and so there's always a risk of
introducing something I mean to some
extent there is continuous exchange of
material between these plets naturally
on top of that as well and now we're
sort of accelerating that process to
some degree
um and so if you dig into europa's
surface which probably is completely
pristine it's very unlikely there has
been much exchange with the outside
world for for its subsurface ocean You
Are For the First Time potentially
introducing bacterial spores into that
environment that may compete or may
introduce spous signatures for the life
you're looking for and so it's it's
almost an ethical question as to how to
proceed with looking for life on on
those subsurface oceans and I I don't
think one we've really have a good
resolution for at this point ethical so
you mean ethical in terms of concern for
the like for preserving life elsewhere
like not to murder it as opposed to the
scientific one I mean we always worry
about a space virus right coming coming
here or or you know some kind of
external source and we would be the
source of that potential contamination
or the other direction yeah I mean they
that you know the whatever whatever
survives in such harsh conditions be
pretty good at uh surviving in all
conditions it might be a little bit more
resilient and robust so it might
actually take a ride on us back home
possibly I mean I'm sure I'm sure that
some people would be concerned about
that I think we would we would hopefully
have some containment uh procedures as
if if we did sample return or you mean
you don't even really need a sample
return these days you can pretty much
send like a little micro laboratory to
the planet to do all the experiments in
you know in situ and then just send them
back to your planet the data and so I
don't think this is necessary that
especially for a case like that where
you might have contamination concerns
that you have to bring samples back um
although probably if you brought back
europan Sushi it would probably sell for
quite a bit with the billionaires in New
York
City Sushi yeah um I would love from an
engineering perspective just to see all
the different candidates and designs for
like the scooper for Venus and the
scooper for Europa and and Mars I
haven't really look deeply into how they
actually like the actual engineering of
collecting assembles because that's the
engineering of that is probably
essential for not either destroying life
or or polluting it with our own microbes
and so on so that that's like an
interesting engineering challenge I
usually for Rovers and Stu focus on the
on the robot on the sort of the mobility
aspect of it on the robotics the
perception and the movement and the
planning and the control but there's
probably the scooper is probably where
the action is
the microscopic sample collection so
basically you have to first clean your
vehicle make sure it doesn't have any
earthlike things on it and then you have
to put it into some kind of thing that's
perfectly sealed from the environment so
if we bring it back or we analyze it
it's not um it's not going to bring
anything else external in yeah I don't
know it it's be that would be an
interesting engineering design there
yeah I mean CES has been uh leaving
these little pods on the surface quite
recently there's some neat photos you
can find online and it's they kind of
look like a lightsaber hilts which so um
that yeah to me I I think I tweeted
something like uh you know this weapon
is your life like don't lose at
curiosity because it's just dumping
these little vials everywhere and it's
yeah it is scooping up these things and
the intention is that in the future um
there will be a sample return mission
that will come and pick these up um but
it's I mean the engineering behind those
things is so impressive the thing that
blows me away the most has been the land
land ings um especially I'm training to
be a pilot at the moment so that's the
sort of you know watching Landings has
become like my pet hobby on YouTube at
the moment and how not to do it how to
do it with different levels of uh
conditions and things but with the you
know when when you think about landing
on Mars Just the light travel time
effect means that there's no possibility
of a human controlling that descent and
so you have to put all of your faith and
your trust in the computer code or the
AI or whatever it is that you've put on
board that thing to to make the correct
descent um and so there's this famous
period called seven minutes of hell
where you're basically waiting for that
light travel time to come back to know
whether your vehicle successfully landed
on the surface of not and during that
period you know in your mind
simultaneously that it is doing these
multi-stages of um deploying its
parachute deploying the crane activating
its Jets to come down and controlling
its descent to the surface um and then
the crane has to fly away so it doesn't
AC hit the Rover and so there's a series
of uh multi-stage points where any any
of them go wrong you know the whole
mission could could go AR um and so the
fact that we are fairly consistently
able to build these machines that can do
this autonomously is to me one of the
most impressive acts of engineering that
NASA have achieved yes the unfortunate
fact about physics is the takeoff is
easier than the
landing and you mentioned Starship one
of of the incredible engineering Feats
that you get to see is the reusable
rockets that take off but they land and
they land uh using control and they do
so perfectly and sometimes when it's
synchronous it's it's just it's
beautiful to see and then with Starship
you see the the Chopsticks that catch
the ship I mean there's just so much
incredible engineering but you mentioned
uh Starships is somehow helpful here so
what's your hope with Starship what kind
of science might it enable Poss
there's two things I mean it's the
launch cost itself which is hopefully
going to mean per kilogram is going to
dramatically reduce the cost of it the
sort of the even if it's a factor of 10
higher than what Elon originally
promised this is going to be a
revolution for the cost to launch that
means you could do all sorts of things
you could launch um large telescopes
which could be basically like jwst but
you don't even have to fold them up jwst
had this whole issue with a design that
it's 6 and 1 half meters across and so
you have to there's no fuselage which is
that large at the time the Aries 4
wasn't large enough for that and so they
had to fold it up into this kind of
complicated origami and so a large part
of the cost was figuring out how to fold
it up testing that it unfolded correctly
repeated testing and you know there was
something like 130 fail points or
something during this unfolding
mechanism and so all of us were holding
our breath during that process but if
you have the ability to Just Launch you
know arbitrarily large masses um at
least comparatively compared to jbst and
very large mirrors into space you can
more or less repurpose groundbased
mirrors um the hubo Space Telescope
mirror and the jbst mirrors are designed
to be extremely lightweight and that
increased their cost significantly um
they have this kind of honeycomb design
on the back to try and minimize the the
weight if you don't really care about
weight because it's so cheap then you
could just literally grab many of the
existing groundbased mirrors across tesk
across the world four meter 5 meter
mirrors and just pretty much attach them
to a chassis and have your own
space-based telescope um I think the
Breakthrough foundation for instance uh
is an entity that has been interested in
doing this sort of thing um and so that
raises the prospects of having not just
one wst that just you know deris is a
fantastic resource but it's split
between all of us cosmologists star
formation uh astronomers those of us
studying exop plants those of us wanting
to study you know the ultra deep fields
and the origin of the first galaxies the
expansion R of the universe everyone has
to share this resource but we could
potentially each have you know one uh
jwst each that is uh maybe just studying
a handful of the brightest exoplanet
stars and measuring their atmospheres
this is important because if you we
talked about this planet trapis 1e
earlier that planet if Jud sted it and
tried to look for Bio signatures by
which I mean oxygen um nitrous oxide
methane it would take it of order of 200
transits to get even a very marginal
what we call 2 a half Sigma detection of
those which basically nobody would
believe with with that and 100 transits
I mean this thing transits once every
six days so you talking about sort of
four years of staring at the same star
with one telescope there'd be some
breaks but it'd be hard to schedule much
else because you have to continuously
catch each one of these transits to
build up your signal to noise and so JC
is never going to do that in principle
technically J could technically have the
capability of just about detecting a bio
signature on an earthlike planet around
around a nons sunlike star but still
impressively we have basically the
technology to do that but we simply
cannot dedicate all of its time
practically to that one resource and so
Starship opens up opportunities like
that of mass producing these kinds of
telescopes which will allow us to survey
for life in the universe which of course
is one of the grand goals of astronomy I
wonder if you can speak to the the
bureaucracy the political battles the
scientific battles for for time on the
James web
telescope is there there must be a
fascinating it's process of scheduling
that all scientists are trying to
collaborate and figure out what the most
important problems are and there's an
interesting network of interfering
scientific experiments probably they
have to somehow optimize over it's it's
a very difficult process I don't envy
the TAC that are going to have to make
this decision we call it the TAC the
time allocation committee that that make
this decision um and I've served on
these before and it's very difficult I
mean typically for Hubble we we were
seeing at least 10 sometimes 20 times
the number of proposals for telescope
time versus available telescope time for
J there has been one call already that
has gone out we called it cycle one and
that was over subscribed by I think
something like 6:1 7:1 and uh the cycle
2 which has just been announced uh
fairly recently and the deadline is
actually the end of this month so my
team totally layser focused on running
our proposals right now um that is
expected to be much more competitive
probably more comparable to what Hubble
saw and so it's hard more competitive
than the cycle one you said already
that's already more competive than the
first cycle so I said the first cycle of
James web was about 6 to1 um and this
will probably more like 20 to1 I would
expect so these are all proposals by
scientists and so on and it's not like
you can schedule at any time cuz if
you're looking for transit times yeah
you have you have a a Time critical
element yes time critical element and
they're conflicting in non like non
obvious ways because the the the
frequency is different the the duration
is different there's there's probably
computational needs that are different
uh the there's the type of sensors the
direction pointing all that yeah it it's
hard and there were certain programs
like doing a deep field study where you
just more or less point the telescope
and that's pretty open I mean you're
just accumulating photons you can just
point at that that patch of the sky um
whenever the telescope is not doing
anything else and just get to your month
let's say a month of integration time is
your is your goal over the lifetime jst
so that's maybe a little bit easier to
schedule it's harder especially for us
looking at cool worlds um because as I
said earlier these these plants Transit
very infrequently MH so we have to wait
if you're looking at the Earth
transiting the Sun an alien watching us
they they would only get one opportunity
per year to do that observation the
transit lasts for about 12 hours um and
so if they don't get that time it's hard
you that's it if it conflicted with
another proposal that wants to do use
the another time critical element it's
much easier for plants like uh these hot
these hot plants or these close-in
plants um because they Transit so
frequently there's may be a 100
opportunities and so then the tat can
say okay they want 10 transits there's
100 opportunities here it's easier for
us to give us time give them time um
we're almost in the worst case scenario
we're proposing to forx Moes around two
cool planets and so we really only have
one bite of the Cherry for each one and
so our sales pitch has been that these
are extremely precious events and more
importantly
jdst is the only telescope the only
machine Humanity has ever constructed
which is capable of finding moons akin
to the moons in our solar system kepa
can't do it even Hubble can't do it J is
the first one and so there is a new
window to the universe because we know
these moons exist they they're all over
the place in the solar system you have
the moon you have IO Kalisto Europa
ganime Titan lots of moons of Fairly
similar size s of 30% the size of the
Earth and this telescope is the first
one that can find them um and so we're
very excited about the profound
implications of ultimately solving this
journey we're on in astronomy which is
to understand our uniqueness we want to
understand how common is the solar
system are we the way are we the
architecture that frequently emerges
naturally or is there something special
about what happened here I think this is
not the worst case the best case it's
obvious it's super rare so you have to
like I would if so I'm I love scheduling
from a computer science perspective
that's my background so algorithmically
to solve a schedule problem I would
schedule the rarest things first and
obviously this is the the jwst is the
first thing that can actually detect a
cool world world so this is a big new
thing you can show off that new thing
happens rarely schedule it first it's
perfect you should be in the T this is
perfect I will I'll file my application
after we're done with this I I you know
this part of me is the OCD part of me is
the computational aspect I love
scheduling uh Computing device because
you have that kind of scheduling on
supercomputers on that scheduling
problem is fascinating how do you
prioritize computation how you
prioritize science uh data collection uh
sample collection all that kind of stuff
stuff it's actually kind of it's kind of
fascinating because data in ways you
expect and don't expect will unlock a
lot of solutions to uh some fascinating
Mysteries and so collecting the data and
doing so in a way that maximize the
possibility of Discovery is really
interesting like from a computational
perspective I agree there's there's a
real satisfaction in extracting the
maximum science per unit time yeah
exactly out of your telescope and that's
that's the tax job um but the the T are
not machines they're not a piece of
computer code um they will make their
selections based off human judgment and
um a lot of the telescope certainly
within the field of exoplanets because
there's different fields of astronomy
but within the field of exoplanets I
think a good expectation is that most of
the telescope time that jwc have will go
towards atmospheric retrieval which is
uh sort of alluded to earlier you know
like detecting molecules in the
atmospheres not bio signatures CU as I
said it's really not designed to do that
it's pushing Jus T probably too far to
expect to do that but it could detect
for example a carbon dioxide Rich
atmosphere on trapis one that's not a bi
signature but you could prove it's like
a Venus in that case or maybe like a
Mars in that case like both those have
carbon dioxide Rich atmospheres doesn't
prove or disprove the existence of life
either way but it is our first
characterization of the nature of those
atmospheres maybe we can even tell the
pressure level and the temperature of
those atmospheres so that's very
exciting but um there's we we are
competing with that and that I I think
that science is completely mind-blowing
and fantastic we have a completely
different objective which is in our case
to try and look for the first evidence
of these small moons around these
planets um potentially even moons which
could be habitable of course so I think
it's a very exciting goal but um attack
has to make a human judgment essentially
about which science are they most
excited by which one has the highest
promise of return the most highest
chance of return and so that's hard
because if you look at a planetary
atmosphere well you know most of the
time the planet has an atmosphere
already and so there's almost a
guaranteed success that you're going to
learn something about the Atmosphere by
pointing J at it whereas in our case
there's a harder cell we are looking for
something that we do not know for sure
exists yet or not and so we are pushing
the telescope to do something which is
inherently more risky yeah but the
existence if shown already gives a
deep lesson about what's out there in
the universe that means that other stars
have similar types of variety as we have
in our solar system they have an IO they
have a Europa and so on which means like
there's a lot of possibility for Icy
planets for water for planets that
enable planets and moons that I mean
that that's super exciting because that
that means everywhere through our galaxy
and Beyond
there is just innumerable possibility
for weird creatures I agree life fors
you don't have to convince me I mean
NASA NASA has been on this quest for a
long time and it's sometimes called eer
Earth it's the frequency of Earth like
usually they say planets in the universe
how common are planets similar to our
Earth in terms of um ultimately we'd
like to know everything about these
plets in terms of the amount of water
they have how much atmosphere they have
but for now it's kind of focused just on
the size and the distance from the Star
essentially how how often do you get
similar conditions to that um that was
kep's primary Mission and it really just
kind of flirted with the answer didn't
quite get to a definitive answer but I
always say look if we're looking if if
that's our primary goal to look for
earthlike I would say worlds then moons
has to be a part of that because we know
that um Earth likee and from the capit
DAT to the preliminar is that earthlike
planets around sunlike stars is not an
inevitable outcome it seems to be
something like a 1 to 10% outcome so
it's not particularly inevitable that
that happens but we do often see about
half of all sunlike stars have either a
mini Neptune a Neptune or a Jupiter in
habital Zone Of Their Stars that's a
very very common occurrence that we see
yet we have no idea how often they have
moons around them which could also be
habitable and so there may very well be
if if even one in five of them has an
earth like moon or even a Mars like Moon
around them then there would be more
habitable real estate in terms of
exomoons than exoplanets in the universe
you can essentially 2x 3x 5x maybe 10x
the number of Hab habitable worlds out
there in the universe our current
estimate for like the Drake equation
absolutely so this this is a one way to
increase the
confidence and increase the the value of
that parameter and just know where to
look I mean we we would like to know
where should we listen for technos
signatures where should we be looking
for Bio signatures um and not only that
but what role does the does the moon
have in terms of its influence on the
planet um we talked about these directly
imaged telescopes earlier these missions
that want to take a photo to quote car
Sean the pale blue dot of our planet but
the pale blue dot of an exoplanet and
that's the dream to one day capture that
but as impressive as the resolution is
that we are planning and conspiring to
design for the future generation
telescopes to achieve that even those
telescopes will not have the capability
of resolving the Earth and the moon
within that it'll be a pale blue dot
pixel but the moon's gray grayness will
be intermixed with that pixel and so
this is a big problem because one of the
ways that we are claiming to look for
life in the universe is a chemical
disequilibrium so you see two molecules
that just shouldn't be there they
normally react with each other or even
one molecule that's just too reactive to
be hang around the Atmosphere by itself
so if you had um oxygen and methane
hanging out together those would
normally react fairly easily and so if
you detected those two molecules in your
pale blue dot Spectra you be like okay
we we have evidence for life something's
metabolizing on this planet um however
the challenge here is what if that moon
was Titan Titan has a methane Rich
atmosphere and what if the pale blue dot
was in fact a plant devoid of life but
it had oxygen because of water
undergoing this photolysis reaction
splitting into oxygen hydrogen
separately so then you have all of the
uh Hallmarks of what we would claim to
be life mhm but all along you were
tricked it was just a moon that was
deceiving you and so we are never going
to we're never going to I would claim
really understand the or or complete
this quest of looking for Life by a
signatures in the universe unless we
have a deep knowledge of the prevalence
and role that moons have they may even
affect the habitability of the planets
themselves of course our moon is
freakishly large by mass ratio it's the
largest moon in the solar system it's a
1% Mass Moon if you look at Jupiter's
moons they're like 10^ minus 4 much
smaller and so our own moon seems to
stabilize the obliquity of our planet it
gives rise to Tides especially early on
when the moon was closer those Tides
would have covered entire continents and
those those Rock pools that would have
been scattered across the entire plateau
may have been the origin of Life on our
planet the moon forming impact may have
stripped a significant fractional
lithosphere of the earth which without
it plate tectonics may not have been
possible we would have had a stagnant
lid because there was just too much
lithosphere stuck on the top of the of
the planet and so there are speculative
reasons but intriguing reasons as to why
a large Moon may be not just important
but Central to the question of having
the conditions necessary for life so
moons can be habitable in their own
right but they can also play significant
influence on the habitability of the
planets they orbit and further they will
surely interfere with our attempts to
detect life remotely from
AAR so uh taking a tangent upon a
tangent uh you've written about uh
binary planets what what's and that
they're surprisingly
common or they might be surprisingly
common what's the difference between a
large Moon and binary planets what what
are binary planets what uh what's
interesting to say here about giant
rocks flying to space and orbiting each
other the thing that's interesting about
binary objects is that they're very
common in the universe binary stars are
everywhere fact the majority of stars
seem to live in binary systems um when
we look at the outer edges of the solar
system we see binary Kyer Bel objects
all the time asteroids Bally bound to
one another Pluto Sharon is kind of an
example of that it's a 10% Mass ratio
system it almost is by many definitions
a binary Planet but now it's a dwarf
planet so yeah I don't know what you
call that now but we we know that these
you know the universe likes to make
things in pairs yeah um so you're saying
our sun is an
incel it's it's looking so most things
are dating they're in relationships and
our ours is alone it it's not a complete
free of the universe to be alone but it
is um it's more common for sunl stars if
you count up all the sunl stars in the
universe about half of the sunlike star
systems are in binary or trinary systems
and the other half are single but
because those binaries are two or three
stars then cumulatively maybe like a
third of all sunic stars are single I'm
trying hard to not anthropomorphize the
relationship the star with each other
triplet the triplet yeah that's yeah
I've met those folks also um so is there
something interesting to learn about the
habitability the how that affects the
probability of habitable worlds when
they kind of couple up like that in
those different ways well it depends
when we're talking about the stars of
the planet certainly if Stars couple up
that has a big influence on the
habitability um of course this is very
famous from Star Wars Tatooine in Star
Wars there's a binary star system and
you have Luke Skywalker looking at the
sunset and seeing two stars come down
and uh for years we thought that was
purely a product of George Lucas's
incredibly creative mind and we didn't
think that planets would exist around
binary star systems it seems like too
tumultuous an environment for a
quiescent planetry disc circumstellar
disc to form planets from and yet uh one
of the astounding discoveries from
Kepler was that these appear to be quite
common in fact as far as we can tell uh
they're just as common around binary
stars as single Stars the only uh caveat
to that is that you don't get plants
close into binary Stars they have like a
clearance region in on the inside where
plants maybe they form there but they
they don't last they are dynamically
unstable in that zone but once you get
out to about the distance of the Earth
orbits the Sun or even a little bit
closer in you start to find plants
emerging and so that's the right
distance for liquid water it's the right
distance for potentially life on those
plants and so there may very well be
plenty of habital plants around the
binary Stars binary plants is a little
bit different um binary plants I don't
think we have um any serious connection
of plant binarity to habitability
certainly when we investigated it that
wasn't our drive that this is somehow
the solution to life in the universe or
anything it was really just a like all
good science questions a curiosity
driven question what's the dynamic are
they legit orbiting each other as they
orbit this uh the star so the formation
mechanism proposed here um because it is
very difficult to form two Proto plets
close to each other like this they were
generally merged within the dis and so
that's why you normally get single
planets but you could have something
like Jupiter and Saturn form at separate
distances they could dynamically be
scattered in towards one another and
basically not quite Collide but have a
very close on encounter now because uh
tidal forces increase dramatically as
the distance decreases between two
objects the tides can actually dissipate
the kinetic energy and bring them bound
into one another so that seemed when we
you know when you first hear that you
think well that seems fairly contrived
that you'd have the conditions just
right to get these ties to cause a
capture but numerical simulations have
shown that about 10% of planet planet
encounters are shown to produce
something like bino planets which is a
startling prediction um and so that
seems at odds with naively the exoplanet
catalog for which we know of so far no
binary planets and we proposed one of
the resolutions to this might be that
the bin planets are just incredibly
difficult to detect which is also
counterintuitive because remember how
they form is through this tidal
mechanism and so they form extremely
close to each other sort of the distance
that iio is away from Jupiter just a few
planetry radi they're almost touching
one another and they're just tily locked
facing each other for eternity and so in
that configuration as it transits across
the star it kind of looks like you can't
really resolve there two planets it just
looks like one planet to you that's
going across the the star the temporal
resolution of the data is rarely good
enough to distinguish that and so you'd
see one Transit but in fact it's two
planets very close together which are
transiting at once and so yeah we wrote
a paper just recently where we developed
um some techniques to try and get around
this problem and hopefully provide a
tool where we could finally look for
these planets the problem of detection
of these planets when they're so close
that was our Focus was how do you how do
you get around this this merging problem
so whether there are or not uh we don't
know we we're planning to do a search
for them but um it it remains an open
question and I think just one of those
fun astrophysics Curiosities questions
whether binary planets exist in the
universe because then you know you have
binary Earths you could have binary
Neptune all sorts of wild stuff that
would you know float to the Sci-Fi
imagination I wonder what the physics on
a binary Planet feels like it might be
trivial I have to think about that I
wonder if there's some interesting
Dynamics like it feel multiple or or
would gravity feel different at
different parts of the the surface of
the sphere when there's another large
sphere that's I would think that the
force would be U fairly similar because
the shape of the object would deform to
a flat geop potential essentially
uniform geop potential but it would lead
to a distorted shape for the two objects
I think they would become ellipsoids
facing one another um so it would be
pretty wild when you you know people
like Flat Earth or spherical Earth you
fly from space and you see a football
shaped Earth it's your own Planet
finally there's proof and I wonder how
how difficult it would be to travel from
one to the other cuz you have to
overcome the
well no it might be kind of easy yeah I
mean they're so close to each other that
helps and I think the most critical
Factor would be how massive is the
planet that's always I mean one of the
challenges with escaping planets there
was a a fun paper one of my colleagues
wrote that suggested that superar
planets may be inescapable mhm if you
were a civilization that were born on a
superar the surface gravity is so high
that the chemical potential energy of
hydrogen or or methane whatever fuel
you're using simply um is at odds with
the with the gravity of the planet
itself and so you would uh you know our
current Rockets I'm not sure the
fraction but maybe like 90% of the
rocket is fuel or something by mass
these things would have to be um like
the size of the the Giza Pyramids of
fuel with just a tiny tip on the top in
order just to escape their plan planetry
atmosphere and so it has been argued
that if you live on a super
Earth you may be you may be forced to
live there forever there may be no
Escape unless you invent a space
elevator or something but then how do
you even build the infrastructure in
space to to do something like that in
the absence of a successful rocket
program um and so the more and more we
we look at our Earth and think about the
sorts of problems we
facing the more you see things about the
Earth which make it ideally suited and
so many regards it it's almost spooky
right that we not only live on a planet
which has the right conditions for life
for intelligent life for sustained
fossil fuel industry just happens to be
in the ground we have plenty of fossil
fuels to to get our Industrial
Revolution going um but also the
chemical energy contained within those
fossil fuels um and hydrogen and other
fuels is sufficient that we have the
ability to escape our planetary
atmosphere and planetary gravity to have
a space program and we also happen to
have a Celestial body which is just
within reach the moon uh which doesn't
also necessarily have to be true where
were the moon not there what effect
would that have had on our aspirations
of a space program in the 1960s would
there have ever been a space race to
Mars or to Venus it's a much harder
certainly for a human program that seems
almost impossible with 1960s technology
to imagine ever come to FR it's almost
as if somebody constructed a set of uh
challenging obstacles before us
challenging problems to solve they're
challenging but they're doable and
there's a sequence of them gravity is
very difficult to overcome but we have
given the size of Earth it's not so bad
that we can still actually construct
propulsion systems that can escape it
yeah and the same with climate change
perhaps I mean climate change is the
next major problem facing our
civilization but we know it is
technically surmountable yeah you know
it's it's a it's it's it is does seem
sometimes like there has been a series
of challenges laid out to
um progresses towards a mature
civilization that can one day perhaps
expand to the Stars I'm a little more
concerned about nuclear weapons uh Ai
and uh uh natural or artificial
pandemics but yes climate CH mean plenty
plenty of plenty of fun Milestones that
we need to cross uh and we can argue
about the severity of each but uh there
is no doubt that we live in a world that
has serious challenges that are pushing
our intellects and our will to the limit
of
whether we're really ready to progress
to the next stage of our development so
thank you for taking the tangent and
there there'll be a million more but can
we step back to Kepler
1625b what is it and you you've talked
about this kind of Journey this effort
to discover uh exom moons so moons out
there or small cool objects out there uh
where does that effort stand and what do
CER
1625b yeah I mean I've been searching
for Mex Moons for most of my
professional career and I think a lot of
my colleagues think I'm kind of crazy to
to still be doing it you know
after after five years of not finding
anything I think most people would
probably try doing something else I even
had people say that to me they said um
you professors and I remember at a a
cocktail party took me to the side an
MIT professor and he said um you know
you should just look look for hot
Jupiters they're everywhere it's really
you can write papers they're so easy to
and I was like yeah but hard jup is just
they're not interesting to me I want to
do something that I feel
intellectually pushes me to the edge and
is maybe a contribution that not no one
else could do but maybe um is not
certainly the thing that anybody could
do I don't want to just be the first to
something for the sake of being first I
want to do something that feels like a
meaningful intellectual contribution to
our society and so you know this exim
Moon problem has been haunting me for
years to try and solve this now as I
said we looked for years and years using
Kepler and the closest we ever got was
just a hint for this one star Kepler
1625 has a Jupiter like planet in orbit
of it and that Jupiter like planet is on
a 287 day period so it's it's almost the
same distance as the Earth around the
Sun but for Jupiter um so that was
already unusual I don't think people
realize that Jupiter likee planets are
quite rare in the universe certainly
mini Neptunes and Neptunes are extremely
common but Jupiter's only about 10% of
sunlike stars have Jupiters around them
as far as we can tell when you say
Jupiter which aspect of Jupiter in terms
of its mass and uh it semi draxis so
anything beyond about half an au so half
the distance of the Earth and the Sun
and something of order of um a tenth of
a Jupiter Mass that's the mass of Saturn
up to say 10 Jupiter masses which is
basically where you start to get to
Brown dwarfs those types of objects
appear to be somewhat unusual most most
solar systems do not have Jupiter's
which is really interesting because
Jupiter again like the moon seems to
have been a pivotal character in the
story of the development of our solar
system perhaps especially having a large
influence of the development of um the
late heavy bombardment and the rate of
asteroid impacts that we receive and
things like this anyway to come back to
1625 this this Jupiter like planet um
had a hint of of something in the data
but what I mean by that is when we
looked at the transit we got the
familiar decrease in light that we
always see when a planet TRS in front of
the star but we saw something extra just
on the edges we saw some extra dips
around the outside it was right at the
hairy edge of detectability we didn't
believe it because um I think one of the
challenges of looking for something for
10 years is that you become your own
greatest skeptic and no matter what
you're shown you're always thinking I've
been it's like falling in love so many
times and it and it not working out
right you you convince yourself it's
never going to be it's never going to
happen not for me you know this just
isn't this isn't going to happen and so
I saw that and I I didn't really believe
it because I didn't dare let myself
believe it but being a good scientist we
knew we had an obligation to publish it
to talk about the result and to follow
it up and to try and resolve what was
going on so we asked for Hubble space
telescript time which was awarded in
that case so we were one of those lucky
20 that got telescope time and we studed
it uh for about 40 hours
continuously and um the to provide some
context the dip that we saw in the cap
data corresponded to a neptune-sized
moon around a Jupiter sized Planet which
was another reason why I was skeptical
that we didn't have that in the solar
system that seems so strange and then
when we got the Hubble data it seemed to
confirm exactly that there was two
really striking pieces of evidence in
the data that suggested this moon was
there another was a fairly clear second
dip in light pretty clearly resolved by
Hubble it was about a five Sigma
detection and on top of that we could
see the planet didn't Transit when it
should have done it actually transited
earlier than we expected it to by about
20 minutes or so and so that's a
Hallmark of a gravitational interaction
between the planet and the moon we
actually expected that you can also
expect that if the moon transits after
the planet then the planet should come
in earlier than expected because the
Barry Center the center of mass lives
between the two of them kind of like on
a on a balancing arm between them and so
we saw that as well so the face
signature matched up the mass of the
moon was measured to be Neptune mass and
the size of the moon was measured to be
Neptune radius and so everything just
really lined up and um we spent months
and months trying to kill it this is my
strategy for anything interesting we
just try to throw the kitchen sink at it
and say we must be tricked by something
and so we tried looking at the you know
the centroid motion of the telescope at
the um the different wavelength channels
that have been observe the pixel level
information and no matter what we did we
just couldn't get rid of it and so uh we
submitted to science and I think at the
time science which is one of the top
Journal said to us um would you mind
calling your paper discovery of an
exomoon and I had to push back and we
said no we're not calling it that I
don't even despite everything we've done
we're not calling it a discovery we're
calling it evidence for an exomoon
because for me I'd want to see this
repeat two times three times four times
before I really would bet my house that
this is the real door and maybe and I I
do worry as I said that perhaps that's
my own skepticism self skepticism going
too far but um I think it was the right
decision and uh since that paper came
out there has been continuous interest
in this object um another team
independently analyzed that star and
recovered actually pretty much exactly
the same results as us the same dip the
same the same wobble of the planet and a
third team looked at it and they
actually got something different they
saw the dip was diminished compared to
what we saw they saw a little hint of a
dip but not as pronounced as what we saw
and they saw the wobble as well so
there's been a little bit of tension
about analyzing the reduction of the
Hubble data um and so the only way my
mind to resolve this is just to look
again uh we actually did propose to
Hubble straight after that and we said
look if our model is right if the moon
is there it came in late last time it
transited after the planet because of
the orbit we can calculate that it
should Transit before the planet next
time if it's not there if it doesn't
Transit before and if we even if we see
a dip afterwards we know that's not our
moon it's obviously some instrumental
effect with the data we had a causal
prediction as to where the moon should
be and so I was really excited about
that but we didn't get the telescope
time and unfortunately if you go further
into the future we no longer have the
predictive capability because it's like
predicting the weather you might be able
to predict the weather next week to some
level of accuracy but predicting the
weather next year becomes incredibly
hard the uncertainties is just grow and
compound as you go forward into the
future more and more how are you able to
know where where the move would be
positioned so you're able to tell the
the the orbiting like geometry and and
and frequency yeah so from the uh
basically from the wobbles of the planet
itself that tells us the orbital motion
of the moon it's the reflex motion of
the Moon the planet isn't it just an
estimate to
where like I'm concerned about you
making a strong prediction here because
like if you don't get if you don't uh
get the moon where the moon leads on the
next time around if you did get Hubble
time couldn't that mean something else
if you didn't see that like cuz you said
it would be an
instrumental I feel I I I feel
um the strong urge to disprove your
which is a really good imperative it's a
good way to do science but like uh this
is such a noisy signal right or blurry
signal maybe uh low resolution signal
maybe that's the yeah I mean it's it's a
five Sigma signal so that's that's at
the slightly uncomfortable Edge I mean
it's often said that for any detection
of a first new phenomena you really want
like a 20 25 segment detection then
there's just no doubt that what you're
seeing is Real This was at that edge I
mean I guess it's comparable to the higs
boson but the higs boson was slightly
different because there was so much
theoretical impetus as to expect a
signal at that precise location um a
Neptune size moon was not predicted by
anyone no one there's no papers you can
find that expect neptun siiz moons
around Jupiter siiz planet so there's I
think we were inherently skeptical about
its reality for that reason um but this
is science in action and when we we you
know we fit the wobbles we fit the dips
and we we have this 3G geometric model
for the motion of the orbit and
projecting that forward we were we found
that about 80% of our projections led to
the Moon to be before so it's not 100%
there is there was maybe 20% of the
cases it was over here but to me that
was a hard enough uh a hard enough
projection that we felt confident that
we could refute the ex which was what I
really wanted I wanted to refutable
That's the basis of science a
falsifiable hypothesis how can you make
progress in science if you don't have a
false iable testable hypothesis and so
that was the the the beauty of this
particular case so there's a numerical
simulation with the moon uh that fits
the data that we observed and then you
can now make predictions based on that
simulation
yeah this is so cool okay it's fun these
are like little solar systems that we
can simulate on the computer and imagine
their motions um but we are we are
pushing things to the very limits of
what's possible and that's double-edged
sword it's both incredibly exciting
intellectually but you're always you're
always risking to some degree the
pushing too far so I'd like to ask you
about the uh the the recent paper you
co-authored an exom Moon survey of 70
cool giant exop planets and the new
candidate coupler 1708 bi I would say
this I'd say there's like three or four
candidates at this point of which we
have published two of them and to me are
to a quite uh compelling and deserve
follow-up observation
um and so there to get a confirmed
detection at least in our case we would
need to see it repeat for sure one of
the problems with the some of the other
methods that have been proposed is that
you don't get that repeatability so for
instance an example of a technique that
would lack that would be gravitational
micr lensing so it is possible with a
new telescope coming up in the future um
called the Roman Space Telescope which
is basically a repurpose by satellite
that's the size of the Hubble mirror
going up into space um it will stare
millions of stars
simultaneously and it will look to see
instead of whether any of those stars
get dimmer for a short amount of time
which will be a Transit it'll look for
the opposite it'll look to see if
anything get brighter and that
brightness increase is caused by another
planetry system passing in front and
then gravitationally lensing light
around it to cause a brightening and so
this is a method of discovering entire
solar system but only only for a only
for a glimpse you just get a short
glimpse of it passing like a you know a
ship sailing through the night just that
that one photo of it now the problem
with that is that um it's very difficult
you know the physics of of gravitational
lensing not surprisingly quite
complicated and so there's many many
possible solution so you might have a
solution which is this could be a red
dwarf star with a Jupiter light planet
around it that's one solution but
another solution is that it's a free
floating Planet a rogue Planet like
Jupiter with an earth like Moon around
it and those two solutions are almost
indistinguishable now ideally we would
be able to repeat the observation we be
able to go back and see well if the moon
really is there then we could predict
its masses predict its motion and expect
it to be maybe over here next time or
something with microlensing it's a one
snapshot event M and so for me it's
intriguing as a way of revealing
something about the examon population
but I always come back to transits
because it's the only method we really
have that's absolutely repeatable that
will be able to come back and prove
everyone prove to everyone that look on
the 17th of October the moon will be
over here and the moon will look like
this and we can actually capture that
image and that's what we see with of
course many EXO planets so we want to
get to that same point of full
confidence full confirmation the slam
dunk detection of these exomoons but um
yeah it's it's been a a hell of a
journey uh to to try and push the field
into that direction and um is there some
resistance to the Transit method not to
the transit me I just say to exomoons so
the transit method is by far the most
the most popular method for looking for
exoplanets but um yeah as I've alluded
to exomoons is is kind of a niche topic
within the discipline of exoplanets and
that's largely because there are people
I think are waiting for those slam dunks
and it was like the if you go back to
the first exoplant discovery that was
made in 1995 by Misha mayor and Didia
kellos um I I think it's true at the
time that they were seen as Mavericks
that the idea of looking for plants
around Stars was considered fringe
science and you know I'm sure many
colleagues told them why don't you do
something more safe like study eclipsing
Stars two binary star systems we know
those exist so why are you wasting your
time looking for planets you're going to
get this um alien moniker or something
and you'll be you'll be seen as a fringe
Maverick scientist and so I think it was
quite difficult for those early Planet
Hunters to get legitimacy and be taken
seriously and so very few people risked
their careers to do it except for those
that were either emboldened to try or
had maybe the career uh maybe like
tenure or something so they didn't have
to necessarily worry about the
implications of failure and so once that
happened once they made the first
discoveries
overnight you know everyone and their
dog was getting into exop players and
all of a sudden the whole you know the
whole astronomy Community shifted and
huge numbers of people that were Once
Upon a Time studying eclipse in Aries
you know changed to becoming exoplanet
scientists and so that was the first
wave of exoplanet scientists we're now
in a kind of a second wave or even the
third wave where people like me to some
degree kind of grew up with the idea of
exoplanets as being normal you know I
was 11 years old I guess when the first
ex planet was discovered and so to me it
was a fairly uh normal idea to grow up
with um and so we've been trained in
exoplanets from the very beginning and
so that brings different perspective to
those who have maybe transitioned from a
different career path um and so I
suspect with exomoons and probably
technos signatures uh astrobiology many
of the topics which are seen at the the
fringes of what's
possible they will all open up into
becoming mainstream one day but every
there's a lot of people who are just
waiting uh waiting for that that
assuredness that there is a secure
career re net ahead of them before they
commit yeah it it does seem to me that
exom moons open wider or open for the
first time the door to to aliens so more
seriously academically studying all
right let's let's look at like alien
worlds like so um I think it's still
pretty fringe to talk about alien life
even like on Mars and the moons and so
on you're kind of like you know it would
be nice but imagine the first time dis
discover a living organism that's going
to change
then then everybody will look like an
idiot for not focusing everything on
this cuz the the possibility of the
things will it it's possible might it
might be super boring it might be very
boring bacteria but even the existence
of life elsewhere yeah some I mean that
changes everything that means life is
everywhere yeah if you knew now that in
5 years 10 years the first life would be
discovered elsewhere you knew that in
advance it would surely affect the way
you approach your entire career as a
especially someone Junior in astronomy
you would surely be like well this is
clearly going to be the direction I have
to dedicate my classes and my training
and my education towards that direction
all the new textbooks all the that's
written I mean uh and I think there's a
lot of value to hedging like allocating
some of the
time to that possibility because the
kind of Discovery we'll the kind of
discoveries we might get in the next few
decades um it feels what like we're on
the verge of a lot of um uh getting a
lot of really good data and having
better and better tools that can process
that data so there's just going to be a
continuous increase of the kind of
discoveries that will open like but a
slam dunk that's hard to come by yeah I
think a lot of us are anticipating I
mean we're already seeing it to some
degree with Venus and the phosphine
incident um but we've seen it before
with Bill Clinton in the White House
lawn announcing life from Mars and there
there are inevitably going to be spous
claims or at least claims which are um
ambiguous to some degree there will be
for sure a high-profile Journal like
nature or science that will one day
publish a paper saying VI a signature
discovered or something like that on
trapis one or some other planet and then
there will be years of back and forth in
the in the literature and that might
seem frustrating but that's how science
works it's you know that's the mechanism
of science at play of people
scrutinizing the results to intense
skepticism and it's like a crucible you
know you burn away all irrelevances
until whatever is left is the truth and
so you're left with this this product
which is that okay we either believe or
don't believe that VI signatures are
there so there's inevitably going to be
a lot of controversy and debate and
argument about it we just have to
anticipate that and so I think you have
to basically have a thick skin to some
degree academically to dive into that
world and you're seeing that with um
with phosphine it's been uh it's it's
been uncomfortable to watch from the
outside the kind of dialogue that some
of the scientists have been having with
each other about that because um they
get a little aggressive yeah and you can
you can you can understand why because
jealousy I don't know I that's me saying
not you that's me talking that I'm sure
there's I'm sure there's some envy and
jealousy involved um on the on the
behalf of those who are not part of the
Discovery but there's also in any case
just leave you know the particular
people of involved in Venus alone in any
case of making a claim of that magnitude
yeah especially life because life is
pretty much one of the biggest
discoveries of all time you can imagine
scientifically um you can see and I'm so
conscious this in myself when I get
close to as I said even the much smaller
goal of setting an exomoon the ego creep
in and so as a scientist we have to be
so guarded against our own egos you see
the lights in your eyes of a Nobel Prize
or um the the fame and fortune and being
Remembered in the history books and we
all grew up in our training learning
about Newton and Einstein these Giants
of the field Fineman Maxwell and you get
the idea of these individual
contributions which get immortalized for
all time and that's seductive it's why
many of us with the skill set to go into
maybe banking instead decided actually
there's something about the idea of
being immortalized and contributing
toward Society in a permanent way that
is more attractive than the financial
reward of applying my skills elsewhere
so to some degree that ego can be a
benefit because it brings in skillful
people into our field who might
otherwise be tempted by money elsewhere
but on the other hand it the closer you
get towards when you start flirting with
that Nobel Prize in your in your eyes so
you think you're on the on the verge of
seeing something you can lose
objectivity a very famous example of
this is uh Barnard star there was a
planet claimed there by Peter vaner Camp
I think it was in 1968 69 and at the
time it would have been the first ever
exop planet ever claimed and um he he
felt assured that this planet was there
he was actually using the wobbling star
method but using the positions of the
Stars to see them to claim this
exoplanet it turned out that this planet
was
was not there subsequent analyses by
both dynamicists and theorists and those
looking at the instrumental data
established fairly um unanimously that
there was no way this planet was really
there but Peter vaner Camp insisted it
was there despite overwhelming evidence
that was occuring against him um and
even to the day he died which was I
think like n in the early '90s he was
still insisting this planet was there
even when we were starting to make the
first genuine exop planet discoveries
and even at that point I think Hubble
had even looked at that star and had
totally ruled out any possibility of
what he was talking about and so that's
a problem how do you get to a point as a
scientist where you just can't accept
anything that comes otherwise because
you're it starts out with the the dream
of Fame and then it ends in a stubborn
refusal to ever back down of course the
flip side of that is sometimes you need
that to have the strength to carry a
belief against the entire scientific
community that resists your beliefs and
so it's it's a double-edged sword that
can happen but it I guess the the
distinction here is evidence yes so in
this case that the evidence was so
overwhelming it wasn't really a matter
of um interpretation it was it was you
had collect You' observe this star with
the same um the same star but with maybe
10 even 100 times greater Precision for
prolonged much longer periods of time
and there was just no doubt at this
point this planet was was a mirage um
and so that's why you have to be very
careful he say don't ever name you know
my my wife and my daughter like name
this planet after me that you discover
and like I can't I can't ever name a
planet after you because I'll be I won't
be objective anymore how could I ever
how could I ever turn around to you and
say that planet wasn't real that I named
after you so you're somebody that talks
about and is it's clear in your eyes and
in your way of being that you love the
the process of discovery that Joy the
magic of just uh you know uh seeing
something new observation a new idea
right um but I guess the point is when
you have that great feeling is to then
switch on the
skepticism like to start like testing um
what does this actually mean is is this
real what are the possible uh different
interpretations that could make this a
lot less Grand than I first imagined and
so both have the wander and the
skepticism all in one brain yeah I think
the generally the more I want something
to be true the more I inherently doubt
it and I think that just comes from you
know I I grew up um with a religious
family and was just sort of
indoctrinated to some degree like many
children are that okay this just normal
that you know this a God and this is the
way the world is uh God created the
Earth and then as I became more you know
well read and literate of of what was
happening in the world scientifically I
started to doubt and it really just
struck me that the hardest thing to let
go of when you when you do decide not to
be religious anymore and it's not really
like a light bul moment but it just kind
of happens over my over sort of 11 to 13
I think for me was happening but it's
that sadness of letting go of this
beautiful dream which you had in your
mind of eternal life for you know for
for behaving yourself on Earth you would
have this beautiful Heaven that you
could go to and live forever and that's
very attractive and for me personally um
that was one of the things that pulled
me against it was this it's it's like
it's too good to be true and that it's
very convenient that this could be um
this could be so and I have no evidence
directly in terms of a scientific sense
to support this hypothesis and it just
became uh really difficult to
reconcile um my growth as a scientist
and I know some people find that
reconciliation I I have not maybe I will
one day um but as a general guiding
principle which I think I I obtained
from that experience was that I have to
be extremely guarded about what I want
to be true because it's going to sway me
to say things which which are not true
if I'm not careful and that's the that's
not what we're trying to do as
scientists so you felt from a religious
perspective that there was um a little
bit of a gravitational field in terms of
your opinions like it was affecting how
you could be as a scientist like as a as
a scientific thinker obviously where
you're young yeah I I think
um I I think that's that's true that
whenever you're when whenever there's
something you want to be true it's it's
the ultimate seduction intellectually
and I worry about this a lot with um
with you know UFOs and with um it's it's
true already with things like Venus
phosphine and uh searching for
astrological
signals we have to guard against this
all the way through from however we're
looking for life however we're looking
for whatever this big question is there
is a part of us I think I would love
there to be life in the universe um I
hope there is life in the universe but
um I'm somewhat uh been on record
several times as being fairly firm about
trying to remain consciously agnostic
about that question I don't want to make
up my mind about what the answer is
before I've collected evidence to inform
that decision that's how science should
work if I already know what the answer
is then what am I doing and that's not a
scientific experiment anymore you've
already decided so what are you trying
to learn what's the point of doing the
experiment if you already know what the
answer is there's no point it's so
complicated because so if I'm being
honest with
myself when I imagine the universe so F
first thing I imagine uh about our world
is that we humans and me certainly as
one particular
human uh no
very my first assumption is I know
almost nothing about how anything works
so first of all that actually applies
for for things that humans do know like
uh you know quantum mechanics and all
the things that there's different
expertises that I just have not
dedicated to so even even that starting
point but if we take all of knowledge as
human civilization we know almost
nothing that's kind of an assumption I
have CU it seems like we keep
discovering Mysteries and it seems like
history human history is defined by
moments when we said okay we pretty much
figured it all out and then you realize
a century later
You' when you said that you didn't
figure out anything okay so that's like
a starting point the second thing I have
is I feel like the entirety of the
universe is just filled with alien
civilizations
statistically there's the important
thing that enables that belief for me is
that they don't have to be humanlike
they can be anything MH and it's just
the fact that life exists and just
seeing the way life is on Earth that it
just finds a way it finds a way in so
many different complicated environments
it finds a way whatever that force is
that same Force has to find a way
elsewhere also
but but then if I'm also being honest
and I I don't know how many hours in a
day I
spend seriously considering the
possibility that we're alone mhm I don't
know when I'm when I when my heart is
and mind are filled with wander I think
about all the different life that's out
there but to really imagine that we're
alone like really imagine all the
vastness that's out there were alone
that not even
bacteria I would say you don't have to
believe that we are alone um but you
have to admit it's a possibility of our
ignorance of the universe so far um you
can have a belief about something in
absence of
evidence and car haen famously describe
that as the definition of faith if you
believe something when there's no
evidence you have faith that there's
life in the universe but you can't you
can't demonstrate you can't prove it
mathematically you can't show me
evidence of that um but is there some so
mathematically math is a funny thing is
there I mean the way physicist think
like intuition so so basic
reasoning is there some value to that
well I'd say we there's certainly you
can certainly make a very good argument
I think you've kind of already made one
just the vastness of the universe is is
the is the default argument people often
turn to that surely there should be
others out there it's hard to imagine um
there are of order of 10 to the 22 stars
in our observable universe and so really
the question comes down to what is the
probability of one of those 10 to 22
planets let's say earthy planets if they
all have earthy planets um going on to
form life spontaneously that's the
process of a Genesis the spontaneous
emergence of life also the word
spontaneous is it funny well okay maybe
we w't use spontaneous but
um um not not being to say uh seeded by
so some some other civilization or
something like this it naturally emerges
cuz even the word
spontaneous makes it seem less likely
yeah like there there just this
chemistry an extremely random process it
could be a very gradual process over
millions of years of growing complexity
in in chemical networks maybe there's a
force in the universe that pushes it
towards interesting complexity pockets
of complexity that ultimately creates
something like life which we can't
possibly Define yet and sometimes it
manifests itself into something that
looks like humans but it could be a
totally different kind of computational
information processing system that we
too dumb to even visualize yeah I mean
certainly I mean it's kind of weird that
complexity develops at all right because
um it seems like the opposite to our
physical intuition if you're training in
physics of entropy that things should
you know complexity is hard to
spontaneously I shouldn't say
spontaneously but hard to emerge in
general um and so that's an interesting
problem I think uh there's been
certainly from an evolutionary
perspective you do see growing
complexity
and there's a nice argument I think it's
by gold who who shows that if you have a
certain amount of complexity um it can
either become less complex or more
complex through random mutation and the
less complex things are are stripping
away something something that was
necessary potentially to their survival
and so in general that's that's going to
be uh not particularly useful in its
survival and so it's going to be
detrimental to strip away a significant
amount of its useful traits whereas if
you add something the most uh typical
thing that you add is probably not
useful at all it's probably just uh
doesn't really affect it survival
negatively but it neither does it
provide any significant benefit um but
sometimes on rare occasions of course it
will be of benefit and so if you have a
certain level of complexity it's hard to
go back in complexity but it's fairly
easy to go forward with enough bites at
the Cherry you will eventually build up
in complexity and that's tensively why
we see complexity grow in in in
certainly in an evolutionary sense um
but also perhaps is operating in
chemical networks that led to the
emergence of life I guess the the real
uh problem I have with the with the
numbers game just come back to that is
that we are talking about a certain
probability of that occurring it may be
to go from the primordial soup however
you want to call it the ingredients that
the earth started with the organic
molecules the probability of going from
that initial condition to something that
was capable of darwinian natural
selection that maybe we could Define as
life um the probability of that is maybe
1% 1% of the time that happens in which
case you're right the universe will be
absolutely teeming with life but it
could also be uh 10 the^ minus 10 in
which case it's one per Galaxy or 10
the^ of minus 100 in which case the vast
majority of universes even do not have
life within it or 90% or 90 you said 1%
you said 1% but it could be 90% if the
conditions the chemical conditions of a
planet are correct or a moon are correct
I admit that it could be any of those
numbers and the challenge is we just
have
no rigorous reason to expect why 90% is
any because we're talking about a
probability of a probability MH what's
is is 90% more aior likely than 10 the^
minus 20 well the thing is we do have an
observation n of one of Earth mhm and uh
it's difficult to know what to do with
that what kind of intuition you build
build on top that because on Earth it
seems like life finds a way okay in all
kinds of conditions in all kinds of
crazy conditions good and it's able to
like build up from the basic chemistry
you could say
okay uh maybe it takes a little bit of
time to develop some complicated
technology like mitochondria I don't
know like
photosynthesis fine but it seems to
figure it figure it out and like do it
extremely well yeah but I would say
you're describing a different process I
mean
um maybe I'm I'm at fault for separating
these two processes but to me you're
describing basically natural selection
Evolution at that point um whereas I'm
really describing AOG Genesis which is
to me a separate distinct process do you
limited human scientists yes but why
would it be a separate process why why
is the birth of Life a separate process
from the process of Life uh like why is
the I mean we're uncomfortable with the
F we're uncomfortable with the big bang
we're uncomfortable with the first thing
I think like where did this come from
right so I think I would say I just
twist that question right say what
you're saying why is it a different
process um why and I would say why
shouldn't it be a different process
which isn't really a good defense except
to say that we we we have we have
knowledge of how Natural Evolution
natural selection Evolution works we
think we understand that process we have
almost no information about the earlier
stages of how life emerged on our planet
it may be that you're right and it is
part of a Continuum it may be that is
also a distinct improbable set of
circumstances that led to the emergence
of Life as a scientist I'm just trying
to be open-minded to both possibilities
if I assert that life must be
everywhere to me you run the risk of
experimented bias um if you think you
know what the answer is if you look at
an earthlike planet and you and you are
preconditioned to think there's a 90%
chance of Life on this planet it's going
to at some level affect your
interpretation of that data whereas if I
however critical you might be of the
agnosticism that I impose upon myself
remain open to both possibilities then I
trust in myself to make a fair
assessment as to the reality of that
evidence for
life yeah but I I wonder sort of
scientifically and and that's really
beautiful to hear and inspiring to hear
uh I I wonder scientifically how many
firsts we truly know of like and then we
don't eventually explain as as as
actually uh a a a step number 1 million
in a long process so I think that's a
really interesting thing if there's
truly first in this universe like you
know for us the B whatever happened at
the bing bang is is a kind of first the
origin of stuff but it just again um it
seems like history shows that we'll
figure out that it's actually a
continuation of something but then
physicists say that time is emergent and
there causality and times is is a very
human kind of construct that it's very
possible that all of this so there could
be really firsts of a thing to which we
attach a
name so whatever we call Life maybe
there is an origin of it yeah and I
would also say I'm open to the idea of
it being part of a continuation but the
continuation Maybe is more broader and
it's a continuation of chemical systems
and chemical networks and the what we we
call this one particular type of
chemistry in this behavior of chemistry
life um but it is just one manifestation
of all the trillions of possible
permutations in which chemical reactions
can occur and we we assert specialness
to it because that's what we are and so
this is it's also true of intelligence
you could extend the same thing and say
you know we're we're looking for
intelligent life in the universe and you
sort of where does where do you define
intelligence where where's that
Continuum of of something that's really
like us are we alone there may be a
Continuum of chemical systems a
Continuum of intelligences out there and
um we have to be careful of our own
arrogance of of assuming specialness
about what we are that we are some
distinct category of phenomena whereas
the universe doesn't really care about
what category we are it's just doing
what it's doing and doing everything in
you know infinite infinite diversity and
infinite combinations is essentially
what it's doing and so we are we are
taking this one slice and saying No this
has to be treated separately and um I
I'm open to the idea that it could be a
truly separate phenomena but it may just
be like a like a snowflake every
snowflake is different it may just be
that this one particular iteration is
another variant of the vast Continuum
yeah maybe the algor them of natural
selection itself is an invention of
Earth I kind of also tend to suspect
that this this whatever the algorithm is
it kind of operates at all levels
throughout the Universe mhm but maybe
this is a very kind of peculiar thing
that um where there's a bunch of
chemical systems that compete against
each other somehow for survival under
limited resources and that's a very
earthlike thing mhm we have a nice
balance of there's a large number of
resources enough to have a bunch of
different kinds of systems competing but
not so many that um they they get lazy
yeah and maybe that's why bacteria were
very lazy for a long time maybe they had
they didn't have much competition quite
possibly I mean I I tried to as as fun
as it is to get into the speculation
about um the definitions of of life and
what life does and this this gross
network of possibilities honestly for me
the strongest argument for remaining
agnostic is is to avoid that that bias
and assessing data and we've SE we've
seen it I mean person LOL I talked about
my channel um and maybe last year or two
years ago you know he's a very famous
astronomer who in the 19th century was
claiming the evidence of canals on Mars
and from him from his perspective and
even at the time culturally it was WI
accepted that Mars would of course have
life I mean I think it's uh seems silly
to us but it was kind of similar
arguments to what we're using now about
exoplanets that well of course there
must be life in the universe how could
it just be here and so it seemed obvious
to people that when you looked at Mars
with its polar caps even you know its
atmosphere had Seasons it seemed obvious
to them that that too would be a place
where life Not only was present but had
emerged to a civilization which actually
was fairly comparable in technology to
our our own because it was building
Canal systems um of course a canal
system seems a bizarre techno signature
to us but it was a product of their time
to them that was The Cutting Edge in
technology it it should be a warning
shot actually a little bit for us that
if we think you know solar panels or
building star links or whatever space
mining is like an inevitable techic
signature that may be laughably
Antiquated compared to what other
civilizations far more advanc than us
may be doing and so anyway personal L he
was he I think was a product of his time
that he thought life was inevitably he
even wrote about it extensively and so
when he saw these lines these L on the
surface of Mars to him it was just
obvious they were canals and he was he
that was experimented bias playing out
he was told for one that he had
basically the greatest eyesight um out
of any of his peers and Opthomologist
had told him that in Boston that his
eyesight was you know absolutely
spectacular so he just was convinced
everything he saw was was real um and
secondly he was convinced there was life
there and so it to him it just added and
then that kind of wasted you know
Decades of research of of treating the
idea of Mars being inhabited by this
canal
civilization um but on the other hand
it's maybe not a waste because it is a
lesson in history of how we should be
always on guard against our own
preconceptions and biases about what
whether life is out there and
furthermore what types of things life
might do if it is that if I were running
this simulation which we'll also talk
about because you make the case against
it but if IUN running a simulation I
would definitely put you in a room with
an alien and just to see you mentally
freak out for hours at a time you for
sure would have thought you will be
convinced that you've lost your mind I
mean no not not not that but I mean like
if we discover Life we discovered
interesting new physical phenomena I
think the right approach is definitely
to be extremely skeptical and be very
very careful about things you want to be
true that's that's really I would say
not I'm not like some extreme denialist
of of evidence if there was if there was
compelling evidence for life on another
planet I would be the first one to be
celebrating that and be shaking hands
with the alien on the White House lawn
whatever that would be you know I grew
up with Star Trek and that was my
fantasy was to you know be Captain Kirk
and fly across the Stars meaning at the
civilization so there's nothing more I'd
want to be true as I've said but um we
we just have to guard against it when
we're we're assessing data um but uh I'm
I have to say I'm very skeptical that we
will ever have that uh Star Trek moment
even if even if there are other
civilizations out there they're never
going to be at a at a point which is in
technological lock step with us similar
level development even uh intellectually
the idea that they could uh have a
conversation with us even through a
translator I mean we can't communicate
with humback whales we can't get with
dolphins in a meaningful way we can sort
of bark orders at them but we can't uh
have abstract conversations with them
about things um and so the idea that we
will ever have that fulfilling
conversation I'm deeply skeptical of and
I think a lot of us are drawn to that it
is maybe a replacement for God to some
degree that that Father Figure
civilization that might step in teach us
the a of our ways and bestow wisdom Upon
Our civilization but they could equally
be a giant fungus that has doesn't even
understand the idea of social
socialization because it's the only
entity on it Planet it just swells over
the entire surface and it doesn't it's
incredibly intelligent because maybe
each node communicates with each other
to create essentially a giant neuronet
but it has no sense of what
communication even is and so alien life
is out there is surely going to be
extremely diverse I'm pretty skeptical
that we'll ever get that that fantasy
moment I always had as a kid of having a
dialogue within the civilization so
dialogue uh yes what about noticing them
what about noticing signals do you hope
so one thing we've been talking about is
getting signatures bio signatures
technos signatures about other planets
maybe uh if we're extremely lucky In Our
Lifetime to be able to meet life
forms uh get evidence of living or dead
life forms on mars or the moons of
Jupiter and Saturn what about getting
signals from out of space Interstellar
signals uh what kind of what would those
signals potentially look
like um that's a hard question to answer
because we are we essentially engaging
in xenos Psychology to some degree what
are the activities of another
civilization a lot of that is what do
the word xenos psychology apologize to
interrupt mean well maybe I'm I'm just
fabricating that word really but they
trying to guess at the um the
machinations and motivations of another
intelligent being that was completely
evolutionary divorced from us so it's
like like you said exom moons it's exop
psychology extra solar yeah psychology
yeah uh Alien psychology is another way
of maybe making it more grounded but um
the it it we we can't really guess at
their their motivations too well but we
can look at the sorts of behaviors we
engage in and at least look for them um
we're always guilty that when we look
for bios signatures we're really looking
for and even when we look for planets
we're looking for templates of earth
when we look for bios signatures we're
looking for templates of earth-based
life when we look for tchis signatures
we tend to be looking for templates of
our own behaviors or extrapolations of
our Behavior
um so ex we there's a very long list of
tenis signatures that people have
suggested we could look for the earliest
ones were of course radio beacons that
was sort of project osma that Frank
Drake was involved in um trying to look
for radio signatures which could either
be um just like blurting out high power
radio signals saying hey we're here or
could even have encoded within them
Galactic encyclopedias for us to unlock
which has always been the aore of the
radio Tech technique um but there could
also be unintentional signatures um for
example you could have something like
the satellite system that we've produced
around the earth the artificial
satellite system starlink uh type
systems we mentioned you could detect
the glint of light across those
satellites as they orbit around the
planet um you could detect a
geostationary satellite belt which would
block out some light as the planet
transited across the star you could
detect solar panels potentially
spectrally on the surface of the planet
Heat Island effects New York is hotter
than New York state by a couple of
degrees because the heat island effect
of the city and so you could thermally
map different planets and detect these
so there's a large array of things that
we do that we can go out and hypothesize
we could look for and then on the
furthest end of the scale you have
things which go far beyond our
capabilities such as um warp drive
signatures which have been proposed you
get these bright flashes of light or
even gravitational wave detections from
ligo could be protected um you could
have Dyson spheres the idea of covering
it basically a star is completely
covered by some kind of structure which
collects all the all the light from the
Star to power the civilization and that
would be pretty easily detectable to
some degree because you're you're
transferring all of the visible light
thermodynamically it has to be reemitted
so it come out as infrared light so
you'd have an incredibly bright infrared
star yet one that was visibly not
present at all and so that would be
pretty intriguing signature to look for
well is there efforts to look for
something like that for for for D spares
out there for with with the strong
infrared signal there has been yeah
there has been and there's been uh I
think in the literature there was one
with the IRAs satellite which is an
infrared satellite they targeted I think
of order of 100,000 Stars uh nearby
stars and found no convincing examples
of what looked like a Dyson Sphere star
and then Jason Wright and his team um
Extended this I think using wise which
is another infro satellite um to look
around galaxies so could an entire
galaxy have been converted into Dyson
spheres or a significant fraction of the
Galaxy which is basically the uh the
kardashev type three right this is the
when you've basically mastered the
entire Galactic pool of resources and uh
again out of a 100,000 nearby galaxies
there appears to be no compelling
examples of what looks like a Dyson
Galaxy if you want to call it that um so
that by no means uh
proves that they don't exist or don't
happen but it seems like it's an unusual
behavior for a civilization to get to
that stage of development and start
harvesting the entire Stellar output
unusual yes I and I mean ligo is super
interesting with gra with gravitational
waves if that kind of experiment could
start seeing some weirdness some weird
signals some that compare to the to the
power of cosmic phenomena yeah yeah yeah
I mean it's a whole new window to the
universe not just in terms of
astrophysics but potentially for Technic
signatures as well I have to say with
the with the warp drives I am skeptical
that warp drives are possible because
you have you have kind of fundamental
problem relativity you can either really
have relativity faster than light travel
or causality you can only choose two of
those three things you really can't have
all three in a coherent Universe if you
have all three you basically end up with
the possibility of these kind of
temporal paradoxes and time loops and
grandfather paradoxes well can't there
be pockets of causality something like
that like where there's uh like pockets
of consistent causality you could design
it in that way you could be you know if
you had a warp drive or a time machine
essentially you could be um Cog you know
you could be very conscious and careful
of the way you use it so as to not to
cause paradoxes or just do it in a local
area or something but the real
fundamental problem is you always have
the ability to do it and so in a in a
vast Cosmic Universe if time machines
were all over the place uh that there's
too much risk of someone doing it right
of somebody having the option of of
essentially breaking the universe with
it this so this is a fundamental problem
Hawking uh has this chronology
protection conjecture where he said that
essentially that it's this just can't be
allowed because it breaks it breaks all
our laws of physics if time travel is
possible current laws of physics yes
correct yeah um and so we' need to rip
up relativity I mean that's the point
it's the current laws of physics so
you'd have to rip up our current law of
relativity to make sense of how FTL
could live in that Universe because you
can't have relativity FTL and causality
sit nicely and play nicely
together but we're currently don't have
quantum mechanics and relativity playing
nice together anyway so it's not like
everything is all a nice little fabric
it's certainly not the full picture
there must be more to go but um so it's
already ripped up so might as well rip
it up a little more and and in the
process actually try to connect the two
things cuz maybe in the unification of
uh of the standard model and uh general
relativity maybe there lies some kind of
new wisdom about of about warp D so by
the way warp D is somehow messing with
the
fabric of the universe to be able to
travel fast than the speed of light yeah
you're basically bending SpaceTime you
could also do it with a wormhole or
attack you know some of the hypothetical
ft say doesn't have to necessarily be uh
the bear Drive the warp drive it could
be any fast than light system as long as
it travels super luminally it will
violate quality and presumably that will
be observable with
Lego uh potentially yeah potentially
depends on I think you know the
properties of whatever the spacecraft is
um I mean one one problem with war
drives is there's all sorts of problems
with war drives but but when like the
start of that sentence one
problem there's just this one minor
problem that we have to get around but
uh when it arrives at its destination it
basically collects this vast uh B has
like an event horizon almost at the
front of it and so it collects all the
collects all this radiation at the front
as it goes and when it arrives all that
radiation gets dumped on its destination
and would basically completely
exterminate the planet it arrives at um
that radiation is also incident within
the shell itself there's Hawking
radiation occurring within the shell
which is pretty dangerous um and then
you know also has it raises all sorts of
exacerbations the firmy Paradox of
course as well so you might be able to
explain why we don't see um a Galactic
Empire and even here is hard you might
be able to explain why we don't see a
Galactic Empire if everybody's limited
to Voyage or two rocket speeds of like
20 km per second or something but it's a
lot harder to explain why we don't see
the stars populated by Galactic
Empires when warp drive is imminently
possible because it makes expansion so
much more trivial that um it it it makes
our life harder um there's there's some
wonderful simulation work being done out
at Rochester where they actually
simulate all the stars in the galaxy or
or a fraction of them and they spawn a
civilization on one of them and they let
it spread out at sublight speeds and
actually the very mixing of the Stars
themselves because the stars are not
static they're in orbit of the galactic
center and they have crossing paths with
each other if you just have a range of
even like five light years and you're
speed is of order of a few per the speed
of light is the maximum you can muster
you can populate the entire galaxy
within something like 100,000 two about
a million years or so so know a fraction
of the lifetime of the Galaxy itself um
and so this raises some uh fairly
serious problems because if any
civilization the entire history of the
of the Galaxy decide to do that then you
know either we shouldn't be here or we
happen to live in this kind of rare
pocket where they chose not to populate
to and so this is sometimes called facte
Hearts facte um as you know the facte is
that a civilization is not here now an
alien civilization has not is not in
present occupation of the earth and
that's difficult to resolve with the
apparent ease at which even a small
extrapolation of our own technology
could potentially populate a Galaxy in
Far faster than Galactic history so to
me by the way yeah the firm of paradox
is truly a paradox for me but I suspect
that if alien visited
Earth I suspect if they do um if they
are everywhere I think they're already
here and we're too dump to see it but
leaving that
aside I think we should be able to in
that case have very
strong obvious signals when we look up
at the stars at the emanation of energy
required we would see we would see we
would see some weirdness that like where
these are these kinds of stars and these
are these kinds of stars that are being
messed with like leveraging the nuclear
fusion of stars to do something useful
like the fact that we don't really see
that like maybe you can correct me
wouldn't we be able to if if there is
like alien civilizations running
galaxies wouldn't we see weirdnesses uh
from an astronomy perspective with the
with the way the stars are behaving
yeah I mean it it depends exactly what
they're doing but I mean the Dyson
Sphere example is one that we already
discussed where a serve of 100,000
nearby galaxies find that they are not
have all been transformed into Dice and
sphere collectors um you could also
Imagine them doing things like we
already paper this recently star lifting
where you can extend the life of your
Star by scooping Mass off the star so
you'd be you know doing Stellar
engineering essentially um space if
you're doing a huge amount of asteroid
mining uh you would have a spectral
signature cuz you're basically filling
the solar system with dust by doing that
there'd be debris from that activity and
so there are um some limits on this um
certainly we don't
see uh you know bright flashes which
would be you know one of these
consequences W drives as I said is as
they decelerate they produce these
bright flashes of light we don't seem to
see evidence of those kind of things um
we don't see anything obvious around the
nearby stars or the stars that we've
serveed in detail be beyond that that
indicate any kind of artificial
civilization the closest maybe we had
was bagin star there was a lot of
interest in there was a star that was
just very peculiarly dipping in and out
his brightness and it was hypothesized
for a time that that may indeed be some
kind of um Dyson like structure so maybe
a Dyson Sphere that's half built and so
as it comes in and out it's blocking out
huge swaths of the star it was very to
explain it really with um any kind of
planet model at the time um but an
easier hypothesis that was proposed was
it could just be a large number of
comets or dust or something or maybe a
planet that had broken apart and as its
fragments orbit around it blocks out
Starlight and it turned out um with
subsequent observations of that star
which especially the amateur astronomy
Community made a big contribution to as
well um that the the dips were chromatic
which was a a real important clue that
that probably wasn't a solid structure
then that was going around it it was
more likely to be dust dust is chromatic
by chromatic I mean it looks different
in different colors so it blocks out
more red light than blue light if it was
a solid
structure shouldn't do that it's it it
shouldn't be it should be opaque right a
solid metal structure or something so
that was one of the clear indications
and and the the behavior of in the way
the light changed or the dips changed
across wavelength was fully consistent
with the expectations of what small
particulates would do um and so that's
that's very hard I mean the real problem
with alien
hunting the real technal this is this is
the real the one problem the one problem
with the war drive and the one problem
with alien hunting yes but well actually
I'd say there's three big problems for
me with any search for life which
includes UFOs all the way to fossils and
Mars is that aliens have three unique
properties as a hypothesis one is they
have essentially unbounded explanatory
capability so there's almost no
phenomena I can show you that you
couldn't explain with aliens to some
degree you could say well the aliens
just have some super high-tech uh way of
creating that illusion um the second one
would be unbounded avoidance capacity so
I might see a UFO tomorrow or and then
the next day and then the next day and
then predict I should see it on Thursday
at the end of the week but then I don't
see it but I could always get out of
that and say well that's just because
they chose not to come here you know
they have this they can always avoid
future observations fairly e easily um
if you survey an exoplanet for Bio
signatures and you don't see oxygen you
don't see methane that doesn't mean
there's no one living there they could
always be either tricking their
atmosphere engineering it we actually
wrote a paper about that how you can use
lasers to hide your bios signatures as
an advanced
civilization um or you could just be
living underground or under water or
something where there's no bio
signatures so you can never really
disprove there's life on another planet
or on another star it's has infinite
avoidance and then finally the third one
is that that we have incomplete physical
understanding of the universe so if I
see a new phenomena which Bo Ain star
was a good example of that we saw this
new phenomena of these strange dips
we've never seen before it was
hypothesized immediately this could be
aliens it's like a god of the gaps but
it turned out to be incomplete physical
understanding and so that happens all
the time in the first PSA that was
discovered same story um Joselyn Bell
kind of somewhat tongue and cheek called
it little green man one because it
looked a lot like the radio signature
that was expected from an alien
civilization but of course it turned out
to be a completely new type of star that
we had never seen before which was a
neutron star um with these two Jets
coming out the top of it and so um
that's a challenge those three things
are really really difficult in terms of
experimental design for a scientist to
work around something that can explain
anything can avoid anything so it's
almost
unfalsifiable and could always just be
to some degree as you said we have this
very limited knowledge of the infinite
possibilities of physical law we're
probably only scratching the surface
each time and we've seen it so often his
in history we may just be detecting some
new phenomena well that last one I think
um a little more okay with making
mistakes on yeah which is because it's
exciting still but because no matter so
you might exaggerate the importance of
the discovery but the whole point is to
try to find stuff in this world that's
weird and try to characterize that
weirdness sure you can throw Little
Green Men as a label on it but
eventually it like it's as mysterious
and as beautiful as as interesting as a
little GRE like we we tend to think that
there's some kind of threshold but like
there's all kind kinds of weird
organisms on this Earth that operate
very differently than humans that are
super interesting uh the human mind is
super interesting I mean like uh
weirdness and
complexity
is is as interesting in any of its forms
as what we might think from Hollywood
what aliens are so like that that's
that's okay looking for weirdnesses on
Mars that's one of the best STS pitches
to do Technic signature work is that you
know we always have that as our fullback
that like we're going to look for alien
signatures if we fail we're going to
discover some awesome new physics along
the way and so even a uh even any kind
of signature that we detect is always
going to be interesting um and so that
that compels us to um have not only the
question of looking for life in the
universe but it can it gives us a strong
scientific grounding as to why this sort
of research should be funded and should
be executed because it always pushes the
frontiers of knowledge I wonder if we'll
be able to discover and be open enough
to a broad definition of aliens where we
see some kind of technos
signature basically like a touring test
like this thing is intelligent M like
it's processing information in a very
interesting way MH but but you can say
that about chemistry you could say that
about physics maybe not physics
chemistry like interesting complex
chemistry you could say that this is
processing this is storing information
this is propagating information over
time it's I mean I want
I it's a gray area between a living
organism that we would call an alien and
I thing that's super interesting is able
to carry some kind of intelligence yeah
in information is a really useful way to
frame what we're looking for though
because it then you're then you're
divorced from making assumptions about
even a civilization necessarily or
anything like that so any kind of
information Rick signature indeed you
can take things like the light curve
from bajin star and ask what is the
minimum number of free parameters or the
minimum information content that must be
encoded within this light curve and the
hope is that maybe from you know a good
example be from a radio signature you
detect something that has you know a
thousand megabytes of of parameters
essentially contained within it that's
pretty clearly at that point not the
product of a natural process or least
any natural process that we could
possibly imagine with our current
understanding of the universe and so
thinking even if we can't decode which
actually I'm skeptical we'd be able to
ever decode it in our lifetimes it would
probably take decades to fully ever
figure out what they're trying to tell
us um but if there was a message there
we could at least know that there is
high information content and there is
complexity and that this is a attempt at
communication and information transfer
and leave it to our subsequent
generations to figure out what exactly
it is they're trying to say what again a
wild question and thank you for uh
entertaining them entertaining them I
really really appreciate that um but
what kind of signal in our lifetime what
kind of thing you do you think might
happen could possibly
happen where the scientific Community
would be convinced that there's alien
civilizations out there like what uh you
already said maybe a strong infrared
signature for something like a Dyson
Sphere that yeah that's Poss that that's
also to some degree a little bit
ambiguous um because that's that's a
Challen
interrupt is where your brain would be
like you as a scientist would be like I
know it's ambiguous but this is really
weird yeah I think if he had something I
can imagine something like a prime
number sequence or mathematical sequence
like the Fibonacci series something
being broadcast mathematically provable
that this is not a physical phenomenon
right I mean yeah prime numbers is a
pretty good case because there's no
natural phenomena that produces prime
number sequences it seems to be a purely
an abstract mathematical concept as far
as I'm aware and so if we detected uh
you know a series of radio blips that we
following that sequence it would be
pretty clear to me or it could even be
uh you know car say can suggested that
Pi could be encoded and that or you
might use the hydrogen line but multiply
by pi like some very specific uh
frequency of the universe like a
hydrogen line but multiply it by a
abstract mathematical constant that
would imply strongly that there was
someone behind the scenes operating that
um sorry stored in which phenomena
though that of a radio wave but the
information I mean we kind of toyed with
this um uh idea and a video I did about
hypothetical civilization on my channel
but one kind of fun way I I do want to
bring the this conversation towards time
a little bit and thinking about um not
just looking for life and intelligence
around us right now but looking into the
past and even into the future to some
degree or communicating with the future
and so we had this fun experiment of
imagining a civilization that was born
at the beginning of the history of the
Galaxy and being the first and what it
would be like for them and they were
desperately searching for evidence of
life but couldn't find it and so they
decided to try and leave something
behind for future civilizations to
discover to tell them about themselves
but of course a radio signature is not
going to work there because it has have
a power source and that's a piece of
Machinery it's going to eventually break
down it's going to be hard to maintain
that for billions of years time scale
and so you wanted something that was
kind of passive that doesn't require an
energy source but can somehow transmit
information which is hard to think about
something that satisfies those criteria
but there was a proposal by one of my
colleagues Luke Arnold which uh inspired
a lot of us in technis signatures and he
suggested that you could build
artificial transitors so you could be
build she sheets of material that
transit in front of the star maybe one
uh thin sheet passes across first then
two then three then five seven so you
could follow the primary number sequence
of these and so there'd be a clear
indication that someone had manufactured
those but they don't require any energy
source because they're just sheets of
material in Orit of the star they would
eventually degrade from microm
meteorites and maybe they always would
become destabilized but they should have
lifetimes far exceeding the lifetime of
any uh battery or mechanical electronic
system that we could at least without
technology conceive of building and so
you can imagine then extending that and
how could you encode not just a prime
number sequence but maybe in the spatial
pattern of this very complex light curve
we see you could encode more and more
information through 2D shapes and the
way those occations happen and maybe uh
you could even encode uh messages and
and in-depth information from you know
you could even imagine it being like a a
lower layer of information which is just
the prime number sequence but then you
look closely and you see there's smaller
divots embedded within those that have a
deeper layer of information to extract
um and so to me something like that
would be pretty compelling that that was
somebody who would manif unless it's
just a very impressive hoax um that
would be a pretty compelling evidence
for the civilization and actually the
methods of uh astronomy right now are
kind of marching
towards being able to better and better
detect a signal like that yeah I mean to
some degree it's just building bigger
aperture in Space the bigger the
telescope the the finer ability to
detect those minute signals do you think
the current of the scientific Community
another weird question but just the
observations that are happening now do
you think they're ready for a prime
number sequence in in the um so if if
we're using the the current method the
transit timing variation method like do
you think you're ready do you have the
tools to detect the prime number
sequence yeah for sure I mean there's
two 200,000 stars that kept them
monitored and it monitored them all the
time it took a photo of each one of them
every 30 minutes measured their
brightness and it did that for four and
a half years and so you have already and
Tessa is doing it right now another
mission and so you have already an
existing catalog and people are uh
genuinely scouring through each of those
light curves with Automated machine
learning techniques we even developed
some in our own team that can look for
weird Behavior we wrote a code called
the weird detector for instance that
you know it was just the most generic
thing possible let don't assume anything
about the signal shape just look for
anything that repeats the signal shap
can be anything and we kind of learn the
template of the signal from the data
itself and then we it's like a template
matching filter to see if that repeats
many many times in the data and so we
actually applied that and found a bunch
of interesting stuff but we didn't see
anything that was the prime number
sequence at least on the Kepler data
that's 200,000 Stars which sounds like a
lot but compared to 200 billion stars in
the Milky Way it's really just
scratching the surface so one because
there could be something much more
generalizable than the prime number
sequence it's ultimately the question of
a signal that's very difficult to
compress in the general sense of what
compress means so maybe as we get better
and better machine learning methods that
automatically figure out analyze the
data to to understand how to compress it
just you'll be able to discover data
that's for some reason is not
compressible but then a you know know
compression really is a bottomless pit
because like that's really what
intelligence is is being able to
compress information yeah and and to
some degree the more you I would imagine
I don't work in compression algorithms
but I would imagine the more you
compress your signal um the the more
assumptions that kind of go on behalf of
the decoda the more skilled they really
have to be you know some of the a prime
number sequence is completely unencoded
information essentially but um if you
look at the AR Rebo message they were
fairly careful with their pixelation of
this simple uh image they sent to try
and make it as interpretable as possible
to be that even a dumb alien would be
able to figure out what we're trying to
show them here because there's all sorts
of conventions and rules that are built
in that we we tend to presume when we
design our messages and so if your
messages assuming they know how to do an
MP3 decoder
particular uh compression algorithm I'm
sure they could eventually reverse
engineer it and figure it out but you're
you're making it harder for them to get
to that point so maybe I always think
you you probably would have a two-tier
system right you'd probably have some
lower tier key system and then maybe
beneath that you'd have a deeper
compressed layer of more in-depth
information what about maybe observing
physical actual physical objects so
first let me go to your Tweet as a
source of inspiration
you tweeted that it's interesting to
ponder that if or clouds are ever mined
by the systems ofan civilizations mining
equipment from billions of years ago
could be in our or Cloud since the or
clouds are they they they extend really
really really really far outside the the
the actual star yeah um that so you know
mining equipment just basic boring
mining equipment out there I don't know
if there's something interesting to say
about or clouds themselves that that are
interesting to you and about possible
non shiny uh light emitting mining
equipment from Alien civilization yeah I
mean that thought I mean that's kind of
the beauty of the field of techno
signatures and looking for life is you
can find inspiration and intellectual
joy in just the smallest little thing
that starts a whole thread of building
upon it and wondering about the
implications and so in this case I was
just really struck by we kind of
mentioned this a little bit earlier the
idea that stars are not static we tend
to think of the Galaxy as having stars
in a certain location from the center of
the Galaxy and they kind of live there
but in truth the stars are not only
orbiting around the center of the Galaxy
um but those orbits are themselves
changing over time they're processing
and so in fact the orbits look more like
a spirograph if you ever done those as a
kid it kind of whirl around and Trace
out all sorts of strange patterns and so
there Stars intersect with one one
another and so uh the current closest
star to us is proximus centu which is
about 4.2 light years away but it will
not always be the closest star and over
millions of years it will be supplanted
by other stars in fact stars that will
come even closer than Proxima within
just a couple of light years and that's
been happening not just we can project
that will happen over the next few
million years but that's been happening
presumably throughout the entire history
of the Galaxy for billions of years and
so if you went back in time it you know
there would have been all sorts of
different nearest Stars right different
stages of the Earth's history and those
stars are so close that their or clouds
um do intermix with one another so the
or Cloud can extend out to even a light
year or two around the earth there's
some debate about exactly where it ends
it probably doesn't really have a
definitive end but kind of more just
kind of Peters out more and more and
more as you go further away by the way
for people who don't know nor Cloud I
don't know what the technical definition
is but a bunch of rocks that kind of no
objects
that orbit the the the star and they can
extend really really far because of
these are objects that probably are
mostly icy Rich um they were probably
formed fairly similar distances to
Jupiter and Saturn but were scattered
out through the interactions of those
giant planets um we see a circular disc
of objects around us which kind of looks
like the asteroid belt but just further
away called the Kyer belt and then
further beyond that you get the or cloud
and the or cloud is not a dis it's just
a sphere it kind of surrounds Us in all
directions so these are objects that
were scattered out through uh
three-dimensionally in all different
directions um and so those objects are
potentially resources for us especially
if you were planning to do an
Interstellar mission one day you might
want to mine the water that's embedded
within those and use that as either
oxygen or fuel for your rocket and so
it's quite possible uh there's also some
rare earth metals and things like that
as well but it's quite possible that a
civilization might use all Cloud objects
as a jumping off point um or or in the
Kyper you have things like Planet 9 even
that's there might even be objects
Beyond in the OR Cloud which are
actually planet likee that we just
cannot detect these objects are very
very faint so that's why they're so hard
to see I mean even Planet 9 it's
hypothesized to exist but we've not been
able to confirm its existence because
it's something like a thousand auu away
from us thousand times the distance of
the Earth from the Sun and so even
though it's probably larger than the
earth the amount of light it reflect
from the sun the sun is just looks like
a star at that point so far away from it
that it barely reflects anything back
it's extremely difficult to detect so
there's all sorts of Wonders that may be
lurking out in the outer solar system
and so this has leads you to wonder um
you know in the OR Cloud that or Cloud
must have intermixed with other or
clouds in the past and so what fraction
of the or cloud is truly belongs to us
belongs to what was scattered from
Jupiter and Saturn what fraction of it
could in fact be uh Interstellar
visitors and of course we've got excited
about this recently because of om mu mua
this Interstellar asteroid which seemed
to be at the time the first evidence of
an Interstellar object but when you
think about the or Cloud inter mixing um
it may be that a large fraction of
comets comets are seeded from the or
Cloud that that eventually come in um
some of those comets May indeed have
been Interstellar in the first place
that we just didn't know about
through this process um there there even
is an example I can't remember the name
there's an example of a comet that has a
very peculiar spectral signature that
has been hypothesized to have actually
been an Interstellar visitor but one
that was essentially sourced through
this or Cloud mixing and so this is kind
of intriguing um it also you know the
outer solar system is just such a it's
like the bottom of the ocean we know so
little about what's on the bottom of our
own planet's ocean and we know next to
nothing about what in the outskirts of
our own solar system it's all Darkness
yeah so like that that's one of the
things is to understand the phenomena we
need light and we need to see how light
interacts with it or what light emanates
from it but most of our universe is
Darkness so it's there could be a lot of
interesting stuff I me this is where
your interest is with the with the cool
worlds and interesting stuff lurks in
the darkness right basically all of us
you know 400 years of astronomy our only
window into the universe has been light
and that has only changed quite recently
with the discovery of gravitational
waves that's now a new window and
hopefully uh well to some degree I guess
solar neutrinos we've been detecting for
but they come from the certain
Interstellar space but we may be able to
soon detect neutrino messages has even
been hypothesized as a way of
communicating between civilizations as
well or just do neutrino telescopes to
um study the universe and so there's a
growing interest in what we'd call
multimessenger astronomy now so not just
messages from light but messages from
these other uh physical um packets of
information that are coming our way uh
but when it comes to the outer Solar
System Light really is our only window
there's two there's two ways of doing
that one is you detect the light from
the or Cloud object itself which as I
just said is very very difficult there's
another trick which we do in the Kyer
belt especially and that's called um an
occultation and so sometimes those
objects will just pass in front of a
distant star just coincidentally these
are very very brief moments they last
for less than a second um and so you
have to have a very fast camera to
detect them which conventionally
astronomers don't usually build fast
cameras most of the phenomena we observe
occurs on hours minutes days even but
now we're developing cameras which can
take you know thousands of images per
second um and yet do it at the kind of
astronomical Fidelity that we that we
need for this kind of precise
measurement and so you can see uh these
these very fast dips you even get the
kind of defraction patterns that come
around which are really cool to look at
and that's I kind of love it cuz it's
almost like passive radar you're you
have these pin Pricks of light imagine
that you live in a giant black sphere
but there's these little pin holes that
have been poked and through those pin
holes almost laser light is shining
through and inside this black sphere
there are unknown things wandering
around drifting around that we are
trying to discover and sometimes they
will pass in front of those little
pencil thin laser beams block something
out and so we can tell that it's there
and it's not an active radar because we
didn't actually you know beam anything
out and get a reflection off which is
what the sun does the sun's like comes
off and it comes back that's more like
an active radar system there more like a
passive radar system where we are just
listening very intently and so um I'm
kind of so fascinated by that the idea
that we could map out the rich
architecture of the outer solar system
just by doing something that could have
done potentially for a long time ago
which is just listening in the right way
just just tuning Our instrumentation to
the correct way of of not listening but
viewing the universe to catch those
objects yeah I mean it's really
fascinating It's seems almost obvious
that your efforts when projected out in
over like 100 200 years will have a
really good map through even methods
like basically Transit timing high
resolution Transit timing but basically
the planetary and the uh the planet
satellite movements mhm that of all the
different star systems out there yeah
and it could revolutionize the way we
think about the solar system I mean that
revolution has happened several times in
the past when we discovered Vesta in the
19th century um that was I think the the
seventh planet for a while or the eighth
planet when it was first discovered and
then we discovered series and there was
a bunch of asteroid objects Janus and so
for a while the textbooks had um there
was something like 13 planets in the
solar system and then they and then that
was just a new capability that was
emerging to detect those small objects
and then we ripped that up and said no
no we're going to change the definition
of a planet and then the same thing
happened when we started looking the
outer skirts of the solar system again
we found Aris we found sedna these
objects which resembled Pluto and the
more and more of them we found make make
and eventually we again had to rethink
the way we even uh contextualize what a
planet is and what the nature of the
outer solar system is um so regardless
as to what you think about the debate
about whether Pluto should be demoted or
not which I know often invokes a lot of
strong feelings it is an incredible
achievement that we were able to
transform our view of the solar system
in a matter of years just by basically
you know charge coupled devices the
things that's in in cameras um those the
invention of that device allowed us to
detect objects which were much further
away much fainter and revealed all stuff
that was there all along and so it
that's the beauty of astronomy there's
just uh so much to discover and even in
our own backyard do you ever think about
this do you imagine what are the things
that will completely change astronomy
over the next 100 years like if you
transport yourself forward 100 years
what are the things that will blow your
mind when you look at wait what would it
be just a very high resolution mapping
of things like holy crap like one
surprising thing might be holy crap
there's like earthlike moons everywhere
yeah and another one could be just
totally different devices for
sensing yeah I think you usually
astronomy moves forward dramatically and
Science in general when you have a new
technological capability come online for
the first time um and we kind of just
gave examples of that there with the
solar system so what kind of new
capabilities might emerge in the next
100 years the capability I would love to
see
is not just I mean we in the next 10 20
years we're hoping to take these pale
blue dot images we spoke about so that
requires building something like jwst
but on even larger scale and optimized
for direct Imaging you have to have
either coronograph or a star shade or
something to block out the staright and
reveal those pale blue dots so in the
next sort of decades I think that's the
achievement that we can look forward to
in our lifetimes is to see photos of
other Earths going beyond that maybe in
our life towards the end of our
lifetimes perhaps I'd love it if we I
think it's technically possible as
breakthrough star shot are giving us a
lot of encouragement with to maybe send
a small probe to the nearest stars and
start actually taking high resolution
images of these objects there's only so
much you can do from far away if you
want to have and we can see it in the
solar system I mean there's only so much
you can learn about Europa by pointing h
space telescope at it but if you really
want to understand that that Moon you're
going to have to send something to orbit
it to hopefully land on it and drill
down to the surface and so the idea of
even taking a a flyby and doing a
snapshot photo that gets beam back that
could be doesn't even have to be more
than 100 pixels by 100 pixels that even
that would be a completely game-changing
capability to be able to truly image
these objects and um maybe at home in
our own solar system we can certainly
get to a point where we produce crude
maps of
exoplanets um one of the kind of the
ultimate limit of what a telescope could
do is governed by its size and so the
largest telescope you could probably
ever build would be one that was the
size of the sun there's a clever trick
for doing this without physically
building a TK that's the size of the sun
and that's to use the Sun as a
gravitational lens This was um proposed
I think by vanan in like 1979 but it
builds upon Einstein's theory of general
relativity of course that there is a
warping of light a bending of light from
the sun's gravitational field and so
distant staright it's like a magnifying
glass anything that bends light is is
basically can be used as a telescope
it's going to bend light to a point now
it turns out the Sun's gravity is not
strong enough to create a you know
particularly great telescope here
because the focus point is really out in
the Kyper belt it's at 550 astronomical
units away from the earth so 550 times
further away from the Sun than we are
and we've you know that's beyond any of
our spacecraft we've ever gone so you
have to send a spacecraft to that
distance which would take 30 40 years
even optimistically improving our
chemical propulsion system significantly
you'd have to bound it into that orbit
but then you could use the entire Sun as
your telescope and with that kind of
capability you could image planets to um
kilometer scale resolution from afar and
that that really makes you wonder I mean
if we can conceive maybe we can't
engineer it but if we can conceive of
such a device what might other
civilizations be currently observing
about our own planet um and perhaps that
is uh why nobody is is visiting us
because there is so much you can do from
afar that to them that's enough they you
know maybe they can get to the point
where they can set our radio leakage um
they can set our terrestrial in you know
television signals um they can map out
our surfaces they can tell we have
cities they can even do infrared mapping
of the heat island effect and all this
kind of stuff they can tell the chemical
composition of our planet and so that
might be enough maybe they don't need to
come down to the surface and study
anthrop in it do anthropology and see
what our civilization is like um but
there's certainly a huge amount you can
do which is significantly cheaper to
some degree than flying there just by
exploiting cleverly the physics of the
universe itself so your intuition is
that's very very well may be true that
observation might be way easier than
travel from a from our perspective from
an alien perspective like we could get
very high
resolution imaging before we can ever
get there it depends on what what
information you want if you want um to
know the chemical composition um and and
you want to know kilometer scale maps of
the planet then you could do that from
afar with some uh version of these kind
of gravitational lenses if you want to
do better than that if you want to image
uh a newspaper set on the porch of
somebody's house you're have to fly
there there's no way unless you had you
know A tes that size of Sagittarius AAR
or something you just simply cannot
collect enough light to do that from
many light years away um so there is
certainly uh reasons why visiting will
always have its place depending on what
kind of information you want um we
proposed in my team actually that the
sun is is a is the ultimate Pinnacle of
telescope design MH but flying to a th
Au is a real pain in the butt because
it's just going to take so long and so a
more practical way of achieving this
might be to use the earth now the Earth
doesn't have anywhere near enough
gravity to create a substantial
gravitational lens um but it has an
atmosphere and an atmosphere refracts
light it bends light so whenever you see
a sunset um just as the sun setting
below the Horizon it's actually already
Beneath The Horizon it's just the light
is bending
through the atmosphere it's actually
already about half a degree down beneath
and what you're seeing is is that is
that curvature of the light path um and
your brain interprets of course to be
following a straight line because your
brain always thinks that um and so you
can use that bending whenever you have
bending you have a telescope and so
we've proposed my team that you could
use this refraction to similar create an
earth siiz telescope called the
terrascope the terrascope we have a
great video on this yeah and uh this do
you have a paper on the telescope I do
yeah great um sometimes get confused
this cuz they've heard of an earth-sized
telescope cuz of they may have heard of
The Event Horizon telescope which took
an image of um what's taken an image
right now of the center of our black
hole and it's very impressive and it
previously did Messi 87 and nearby super
massive black hole and so those images
were interferometric so they were small
telescopes scattered across the Earth
and they combined the light paths
together interferometrically to create
effectively an earth-sized um angular
resolution telescopes always have two
properties there's the angular
resolution which is how small of a thing
you can see on the surface and there's
the magnification how much brighter does
that object get versus just your eye or
some small object now what what the
Event Horizon telescript did it traded
off um amplification or magnification
for for the angular resolution that's
what it wanted it wanted that high
angular resolution but it doesn't really
have much Photon collecting power
because each telescope individually is
very small the telescope is different
because it is literally collecting light
with a with a light bucket which is
essentially the size of the Earth and so
that gives you both benefits potentially
not only the high angular resolution
that a large aperture promises you but
also actually physically collects all
those photons so you can detect light
from very very far away through outer
edges of the Universe um and so we yeah
we propose this as a possible future uh
technological way of achieving these
these
extreme goals ambitious goals we have in
astronomy but um it's a very difficult
system to test because you essentially
have to fly out to these Focus points
and these Focus points lie beyond the
moon so you have to have someone who is
willing to fly beyond the moon and
hitchhike an experimental telescope onto
it and do that cheaply if it was
something doing low earth orbit it'd be
easy you could just attach a cube that
to the next Falcon 9 rocket or something
and test it out probably only cost you a
few tens of thousands of dollars maybe
hundred thousand dollars but there's
basically no one who flies out that far
except for uh bespoke missions such as
like a mission that's going to Mars or
something that would that would pass
through that kind of space and they
typically don't have a lot of leeway in
excess payload that they willing to
strap on for radical experiments so
that's been the problem with it in
theory it should work beautifully but
it's a very difficult idea to
experimentally test can you elaborate
why the focal point is that far away so
you get about half a degree Bend from
the Earth's atmosphere um when you're
looking at the Sun at the Horizon and
you get that two times over if you're
outside of the planet's atmosphere
because it comes you know the star is
half a Bend to use on the horizon then
half a degree back out the other way so
you get about a one degree Bend you take
the radius of the Earth which about
7,000 km and do your arctan function you
lend up with a distance that's about two
it's actually the the inner focal point
is about 2/3 the distance of the Earth
Moon system the problem with that inner
focal point is not useful because that
light Ray path had to basically scrape
the surface of the Earth so it passes
through the clouds it passes through all
the thick atmosphere it gets a lot of
Extinction along the way if you go
higher up in altitude you get less
Extinction in fact you can even go above
the clouds and so that's even better
because the clouds obviously are going
to be a pain in the neck for doing
anything Optical um but the problem with
that is that the atmosphere because it
gets thinner at higher altitude it bends
light less and so that pushes the focal
point out so the most useful focal point
is actually about three or four times
the distance of the Earth Moon
separation and so that's what we call
one of the LR points essentially out
there and so there there was a stable
orbit it's kind of the outermost stable
orbit you could have around the earth um
so the
atmosphere uh does bad things to to the
signal yeah it's it's absorbing light um
is that possible to to reconstruct this
the to to to remove the noise whatever
so it's just strength it's not nothing
else it's possible to reconstruct I mean
to some degree we do this as's a
technology called Adaptive Optics that
can correct for what's called wavefront
errors that happen through the Earth's
atmosphere the Earth's atmosphere is
turbulent it is not a single plane of
air of the same density there's all kind
of Wiggles and currents in the air and
so that each little layer is uh bending
light in in slightly different ways and
so the light actually kind of follows a
wiggly path on its way down what that
means is that um two light rays which
are traveling at slightly different
spatial separations from each other will
arrive at the detector at different
times uh because one maybe goes on more
or less a straight path and the other
one Wiggles down a bit more before it
arrives and so you have an
incoherent um light source um and when
you're trying to do image Rec
construction you always want a coherent
light source so the way they correct for
this is that this if this path had to
travel a little bit faster uh straight
one goes faster and the wiggly one takes
longer the mirror is deformable and so
you actually bend the mirror on this on
the on the straight one down a little
bit to make it an equivalent light path
distance so the mirror itself has all
these little actuators and it's actually
made up of like thousands of little
elements almost looks like a liquid
mirror because they can manipulate it in
kind of real time and so they scan the
atmosphere with a laser beam to tell
what the defamations are in the
atmosphere and then make the corrections
to the mirror to account for it that's
amazing so you could you could do
something like this for the Terrace
grrip but it would be um it's cheaper
and easier to go above the atmosphere
and just fly out I think so it would be
very it's a very that's a very
challenging thing to do and normally
when you do Adaptive Optics as it's
called you're looking straight up so
you're or we're very close to straight
up if you look at the Horizon we
basically never do astronomical
observations on the horizon because
you're looking through more atmosphere
the if you go straight up you're looking
at the thinnest portion of atmosphere
possible but as you go closer and closer
towards the horizon you're increasing
what we call the air mass the amount of
air you have to travel through so here
it's kind of the worst case cuz you're
going through the entire atmosphere in
and out again with a terrascope so you'd
need a very impressive adaptive optic
system to crit for that so yeah I would
say it's probably simpler at least for
proof of principle just to test it with
um with with with having some satellite
that was much wider orbit now speaking
of traveling out into deep space yeah
you already mentioned this a little bit
uh you uh made a beautiful video called
The Journey to the End of the Universe
and sort of at the start of that you're
talking about Alice andari so what would
it take for humans or for human-like
creatures to travel out to Alpha
centuri there's a few different ways of
doing it I suppose um one is it depends
on how fast your ship is that's always
going to be the determining Factor if we
devised some indide proportion system
that could travel a fraction of the
speed of light then we could do it in
our lifetimes which is I think what
people normally dream of when they think
about inter you know propulsion and
travel that you could literally step
onto the spacecraft maybe a few years
later you step off and Al centur B you
walk around the surface and come back
and visit your family there would be of
course a lot of relativistic time
dilation as a result of that trip you
would have aged a lot less than people
back on Earth by traveling close to the
speed of light for some fraction of time
um the challenge of this of course is
that we have no such propulsion system
that can achieve this so but you think
it's it's possible like uh
so uh you have a paper called the Halo
drive fuel free relativistic propulsion
of large masses via recycled Boomerang
photons so uh do you think uh first of
all what is that and and second of all
uh how difficult are alternate
propulsion systems yeah so
the before I took the Halo drive there
was there was an idea because I think
the Halo drive is not going to solve
this problem I'll talk about the Halo
drive in a moment but the Halo drive is
is useful for a civilization which is a
bit more advanced than us that has
spread across the stars and is looking
for a cheap highway system to to get
across the Galaxy for that first step um
because just to context that the the
Halo drive requires black hoal so that's
why you're not going to be able to do
this on the Earth right now um but there
are lots of black holes in the Milky
wayte that's the good news so we'll come
to that in a moment but if you're trying
to travel to AF sentu without a black
hole um then the the most you know there
were some ideas out there there was a
project dellis and project Icarus that
were two projects at the um British
interplanetary Society conjured up on
sort of a 20 30 year time scale and they
asked themselves if we took existing and
speculatively uh but realistic attempts
at Future technology that are emerging
over the next few decades how far could
we P into uh travel system and they
settled on uh Fusion drives in in that
so if we had the ability to essentially
U either detonate you can also Imagine
That kind of nuclear fishion or nuclear
fusion bombs going off behind the
spacecraft and propelling it that way or
having some kind of uh successful
nuclear fusion reaction um which
obiously we haven't really demonstrated
yet as a propulsion system then you
could achieve something like 10% the
speed of light in those systems but
these are huge spacecrafts and I think
you need a huge spacecraft if you're
going to take people along um the
conversation recently is actually
switched and that's that idea is kind of
seems a little bit Antiquated now and
most of us have kind of given up in the
idea of people physically
biologically stepping on board the
spacecraft and maybe we'll be sending
something that's more like a micro probe
that maybe just weighs a a gram or two
and that's much easier to accelerate you
could push that with a laser system to
very high speed get it to maybe 20% of
the speed of light it has to survive the
journey probably a large fraction of
them won't survive the journey but
they're cheap enough that you could
maybe manufacture millions of them and
some of them do arrive and able to send
back an image or maybe even uh if you
wanted to have a person there we might
have some way of doing like a
telepresence or some kind of delayed
telepresence or um some kind of
reconstruction of the planet which is
sent back so you can digitally interact
with that environment in a way which is
um not real time but representative of
what that planet would be like to be on
the surface so we might be more like
digital visitors to these planets
certainly far easier practically to do
that than physically forcing this wet
chunk of meat to Fly Light across space
to do that um and so that's maybe uh
something we can imagine down the road
the Halo drive as I said is is thinking
even further ahead and if you did want
to launch large masses large masses
could even be Planet siiz things in the
case of the Halo drive you can use black
holes so this is kind of um a trick of
physics you know I often think of the
universe as like a big computer game and
you're trying to find cheat codes hacks
exploits that the Universe didn't intend
for you to use but once you find them
you can address all sorts of interesting
capabilities that you didn't previously
have yeah and um the Halo drive does
that with black holes so if you have two
black holes which are very common
situation a binary black hole um and
they're inspiraling towards each other
ligos detected I think dozens of these
things maybe even over a 100 at this
point and these things as they merge
together they uh the Prem merger phase
they're they're orbiting each other very
very fast even close to the speed of
light and so Freeman Dyson uh before he
passed away I think in the' 70s he had
this provocative paper called
gravitational machines and he suggested
that you could use Neutron stars as a
Interstellar propulsion
system and neutron stars are sort of the
uh the you know the lower Mass version
of a binary black hole system
essentially in this case he suggested
just doing gravitational slingshot just
fly your spacecraft into this uh very
Compact and relativistic binary system
and you do need neutron stars because if
there were two stars they'd be
physically touching each other so the
neutron stars are so small that like 10
km across they can get really close to
each other and have these very very fast
orbits with respect to each other you
shoot your spacecraft through right
through the middle like right through
the eye of a needle and you do a
slingshot around one of them and you do
it around the one that's coming sort of
towards you so one them be coming away
one will be coming towards you any one
point and then you could basically steal
some of the kinetic energy in the
slingshot in principle you can s up to
twice the uh speed you can take your
speed and it becomes your speed plus
twice the the speed of the black of the
neutron star in this case and that would
be your new speed after the slingshot
this seems great because it's just free
energy basically you're not doing any
you know you're not generate you have a
nuclear power react or anything to
generate this you're just stealing it um
and indeed you can get to relative stick
speeds this way so I loved that paper
but I had a criticism and the criticism
was that this is like trying to fly your
ship into a blender right this is this
is two neutron stars which have huge
tital forces um and they're whipping
around each other once every second or
even less than a second and you're
trying to fly your spaceship and do this
maneuver that is pretty precarious and
so it just didn't seem practical to me
to do this but I loved it and so I I I
took that idea and this is how science
is it's iterative it's it's you take a
previous great man's idea and you just
sort of maybe slightly tweak it and
prove it that's how I see the Halo drive
and I just suggested why not replace
those out for black holes which is
certainly very common and rather than
flying your ship into that uh that hell
hole of a blender System you just stand
back and you fire a laser beam now
because black holes have such intense
gravitational fields they can bend light
into complete 180s they can actually
become mirrors so you know the sun bends
light by maybe a fraction of a degree um
through gravitational lensing but you
know a compact object like a black hole
can do a full 18 180 in fact if you
obviously if you if you went too close
if you put the laser beam too close the
black hole would just fall into it and
never come back back out so you just
kind of push it out push it out push it
out until you get to a point where it's
just skirting The Event Horizon and then
that laser beam skirts around and it
comes back now the laser beam wants to
do a gra I mean it is doing a
gravitational slingshot but laser I mean
light photons can't speed up and like in
like the spaceship case so instead of
speeding up the way they steal energy is
they they increase their frequency so
they become higher energy Photon packets
essentially they get blue shifted so
that you send maybe a red laser beam
that comes back blue it's got more
energy in it and because um photons
carry momentum which is somewhat
unintuitive in everyday experience but
they do that's how solar cells work they
carry momentum they push things um you
can even use them as laser tweezers and
things to pick things up um because they
push the me it comes back with more
momentum than it left so you get an
acceleration force from this and again
you're just sealing energy from the
black hole to do this so you can get up
to the same speed it's basically the
same idea as Freeman Dyson but doing it
from a safer distance and there should
be a order of you know a million or so
or 10 million black holes in the Milky
Way galaxy um some of them would be even
as close as sort of 10 to 20 light years
when you do the occurrence rate
statistics of how close you might expect
feasibly one to be they're of course
difficult to detect because they're
black and so they're inherently hard to
see but statistically there should be
plenty out there in the Milky Way and so
these objects would be natural Waypoint
station you could use them to both
accelerate away and to break and slow
down and on top of all this you know
there's we've been talking about
astronomy and cosmology there's been a
lot of
exciting breakthroughs in in detection
and exploration of uh black holes so the
the the boomerang F boomeranging photons
that you're talking about there been a
lot of work on photon rings and just all
the fun stuff going on outside the black
hole yeah um so all the the garbage
outside is actually might be the thing
that holds a key to understanding what's
going on inside and there's the Hawking
radiation there's all kinds of
fascinating stuff like uh I mean there
there's trippy stuff about black holes
that I can't even well most people don't
understand I mean the
holographic principle with the plate and
the information being stored potentially
outside of the black hole I don't even I
can't even comprehend how you can
project a three dimensional object on 2D
and somehow store information where it
doesn't destroy it and if it does
destroy it uh challenging all the
physics all all of this is
very uh
interesting especially for kind of more
practical applications of how the black
hole can be used for propulsion yeah I
mean it may be that black CS are used in
all sorts of ways um by Advanced
civilizations I think uh again it's been
a popular idea in science fiction or
science fiction Trope that Sagittarius
AAR the super massive black Cole and the
centr Galaxy could be the best place to
look for intelligent life in the
universe because it is a giant uh engine
in away you know a unique capability of
a black hole is you can basically throw
matter into it and you can get these
jets that come out the incretion discs
and the jets that fly out and so you can
more or less use them to convert matter
into energy V equal mc² and there's
pretty much nothing else um except for
you know Annihilation with with its own
antiparticle as a way of doing that
so they have some unique properties you
could perhaps power a civilization by
just throwing garbage into a black hole
right just throwing asteroids in power
your civilization with as much energy as
you really would ever plausibly need and
you could also use them to accelerate
away Across the Universe and you can
even imagine using small artificial
black holes as thermal generators right
so the Hawking radiation from them kind
of exponentially increases as they get
smaller and smaller in size and so um a
very small black hole one you could
almost imagine like holding in your hand
would be a fairly significant heat
Source um and so that raises all sorts
of prospects about how you might use
that in an engineering context to power
your civilization as well um you have a
video on becoming a CF type one
civilization what what's our hope for
doing that or a few orders of magnitude
away from that yeah it is surprising I
think people tend to think that we're
close to this this scale the the
kardashev type one is is defined as a
civilization which is using as much
energy as is essentially incident upon
the planet from the Star um so that's of
order I think for the Earth of something
like 10 to the 5 teros or 10 the 7 teros
is a it's a gigantic amount of energy
and we're using a tiny tiny tiny
fraction of that right now so um you
know if you became a Kev type one
civilization which is seen not
necessarily is a goal into itself I
think people think why why are we
aspiring to become this energy hungry
ization you know surely um our our
energy needs might become you know might
impr improve our efficiency or something
as time goes on but ultimately the more
energy you have access to the greater
your capabilities will be I mean if you
want to lift Mount Everest into space
there is just a calculable amount of
potential energy change that that's
going to take in order to accomplish
that and the more energy you have access
to as a civilization then clearly the
easier that energy achievement is going
to be so depends on what you're ask
ation are as a civilization it might not
be something we want to ever do but well
but we should make clear that lifting
heavy things isn't the only thing it's
uh it's just doing work so it could be
computation it could be it could be more
and more and more and more sophisticated
and larger and larger and larger
computation which is it does seem where
we're headed with a uh ve very fast
increase in um the the scale and the
quality of our computation outside the
human brain artificial comp competition
yeah I mean competition is a great
example of I mean already I think
something like 10% of us power
electricity use is going towards the
supercomputing centers so there's a
there's a vast amount of uh current
engine needs which are already going
towards Computing we surely only
increase over time um if we start ever
doing anything like mind uploading or
creating simulated realities that that
cost will surely become almost a
dominant source of our energy
requirements at that point if
civilization completely moves over to
this kind of post-humanism stage and so
it's not unreasonable that our energy
needs would continue to grow certainly
historically they always have at about
2% per year and so if that continues
there is going to be a certain point um
where you're running up against the
amount of energy which you can Harvest
because it's you're using every even if
you cover the entire planet in solar
panels um there's no more energy to be
had um and so this is a you know there's
a few ways of achieving this I sort of
talked about in the video how there were
several renewable energy sources that
we're excited about like geothermal wind
power waves but pretty much all of those
don't really scratch the surface or
don't really scratch the itch of getting
into a kardashev type one civilization
they're meaningful now I would never
tell anybody don't do wind power now
because it's it's it's clearly useful
our current stage of a civilization but
it's not it's going to be a pretty
negligible fraction of our energy
requirements if we got to that stage of
development and so there has to be a
breakthrough in either I ability ility
to harvest solar energy which would
require maybe something like a space
array of solar panels of beaming the
energy back down or some developments uh
and Innovations in in nuclear fusion
that would allow us to essentially
reproduce the same process of what's
producing in the Solar photons but here
on Earth um but even that comes with
some consequences if you're generating
the energy here on Earth and you're
doing work on it on Earth then that work
is going to produce waste heat and that
waste heat is going to increase the
ambient temperature of the planet and so
you whether even if this isn't really a
greenhouse effect that you're increasing
the temperature of the planet this is
just the amount of computers that are
churning you put your hand to a computer
you can feel the warmth coming off them
if you do that much work of literally
you know the entire instant energy of
the planet is doing that work uh the
planet is going to warm up significantly
as a result of that and so you know
that's uh it that clearly indicates that
this is not a sustainable path that
civilizations as they approach Kev type
one are going to have to leave planet
Earth which is really the point of that
video to show that it's a Kev type one
civilization even though it's defined as
instant energy upon a planet that is not
a species that is going to still be
living on their Planet at least um in
isolation they will have to be
harvesting energy from afar they will
have to be you doing work on that energy
outside of their Planet because
otherwise you're going to dramatically
change the environment in which you live
well yeah so the it's uh the more energy
you create the more energy you use the
more the higher the imperative to expand
out into the universe but also not just
the imperative but the uh the
capabilities and you're you've kind of
as a side on your lab page mentioned
that you're sometimes interested in
astroengineering
uh so what what kind of uh space
architectures do you think we can build
to house humans or interesting things
outside of Earth yeah I I mean there's
there's a lot of fun ideas here um one
of the classic ideas is an oal cylinder
or a Stanford Taurus these are like two
rotating structures that were devised in
space that're basically using the
centrifugal force as artificial gravity
um and so these are structures which
tend to be many kilometers across that
you're building in space but could
potentially habitat um millions of
people in in orbit of the earth um of
course you could imagine pulling them if
you you know the expanse does a pretty
good job I think of exploring the idea
of human exploration of the solar system
and having uh many objects many of the
small near Earth objects and asteroids
inhabited by mining colonies um one of
the ideas we've played around with our
group is this technology called aqu
quazite aqu quazite is um an extension
again we always tend to extend previous
ideas ideas built upon ideas but an
extension of idea called a statite a
datte was an idea proposed I think by
Ron forward in the 1970s 1970s seemed to
have all sorts of wacky ideas don't know
what was going on then we the I think
the Stanford Taurus the O'Neal cylinder
statites um the the gravitational lens
people were really having fun with
dreaming about space in the 70s uh the
statti is is basically a a solar sale
but it's such an efficient solar sale
that the outward force of radiation
pressure equals the inward Force force
of gravity from the Sun mhm and so it
doesn't need to orbit normally you avoid
the sun is pulling us right now through
force of gravity but we are not we are
not getting closer towards the sun even
though we are Falling Towards the sun
because we're in orbit which means our
translational speed is just enough to
keep us at the same altitude essentially
from the Sun and so you're in orbit and
that's how you maintain distance a
statite doesn't need to do that it could
be basically you know completely static
in inertial space but it's just
balancing the two forces of radiation
pressure and inward gravitational
pressure a quazite is the in between of
those two states so it's it has some
significant outward pressure but not
enough to resist fully falling into the
star and so it compensates for that by
having some translational motion so it's
in between an orbit and a statite and so
what that allows you to do is maintain
artificial orbits so normally you you
know if you want to calculate your
orbital speed of a of something that say
say half an au you would use kep's third
law and go through that and you'd say
okay you know if it's that half an au I
can calculate the period by P squ as
proportional to a cubed and go through
that but for a um a quazite you can
basically have any speed you want it's
just a matter of how much uh how much of
the gravitational force are you
balancing out you effectively enter an
orbit where you're making the mass of
the star be less massive than it really
is so it's as if you orbiting a 0.1
solar mass star or 0 2 solar mass star
whatever you want and so that means that
uh Mercury orbits with a pretty fast
gravitation uh a pretty fast orbital
speed around the sun because it's closer
to the Sun than we are but we could put
something in Mercury's orbit that would
have a slower speed and so it would
crack with the Earth and so we would
always be aligned with them at all times
and so this could be useful if you
wanted to have a um either a chain of of
colonies or something that we're able to
easily communicate and trans and uh and
move between one another between these
different bases You' probably use
something like this to maintain that uh
easy
transferability or you could even use it
as a uh a space weather monitoring
system which actually proposed in the
paper we know that uh major events like
the Caron event that happened you know
can knock out all of our electromagnetic
systems quite easily a major solar flare
could do that a g magnetic storm but if
we had the ability to detect those uh
higher elevated activity Cycles in
advance um the problem is they travel
obviously pretty fast and so it's hard
to get ahead of them but you could have
a station which is basically sampling
solar flares very close to the surface
of the Earth and as soon as it detects
anything suspicious um magnetically it
could then send that information
straight back at the speed light to your
Earth and give you maybe uh half an hour
warning or something that something you
know something bad was coming you should
shut off all your uh systems or get in
your Faraday cage now and protect
yourself um and so these These quites
are kind of a cool trick of again kind
of hacking the laws of physics it's like
another one of these exploits that the
Universe seems to allow us to do to
potentially manifest um these artificial
systems that would otherwise be
difficult to to produce so leveraging
natural phenomena
yeah that's always the key is is to work
in my mind is to work with nature that's
how I see astroengineering right rather
than against it you're not trying to
force it to do something you know it
that's why you always think solar energy
is so powerful because um in the battle
against nuclear fusion nuclear fusion
you're really fighting a battle where
you're trying to confine plasma into
this extremely tight space or um it's
the sun does this for free it has
gravitation and so that's the that's in
essence what a solar panel does it it's
exp it is a nuclear fusion reactor
fueled Energy System but it's just using
gravitation for the confinement and
having a a Hu a huge standoff distance
for it energy collection and so um there
are tricks like that it's very naive
simple trick in that case where we can
rather than having to reinvent the wheel
we can use the space infrastructure if
you like the astrophysical
infrastructure that's already there to
our benefit yeah I think in the long Arc
of human history probably natural
phenomena is the right Solution that's
the simple that's the elegant solution
CU all the power is already there that's
why a d sphere in the long sort of but
you don't know what a d sphere would
look like but some kind of thing that
leverages the power the energy that's
already in the sun is is better than uh
creating artificial nuclear uh fusion
reaction but then
again that brings us to a topic of AI
how much of
this if we're traveling out there inter
St of travel or um doing some of the
interesting things we'll been talking
about how much of those ships would be
occupied by AI systems do you
think what would
the what would be the living organisms
occupying those
ships yeah it it's depressing to think
about AI in the search for life
because it had I mean I've been thinking
about this a lot over the last few weeks
with playing around with chat gbt 3 like
many of us and being astonished with its
capabilities and you see that it that
our
society is undergoing a change that
seems significant in terms of the
development of artificial intelligence
we've been promised this revolution this
Singularity for a long time but it
really seems to be stepping up its uh
its pace of development at this point
and so that's interesting because as
someone who looks for alen life out
there in the universe
um it sort of implies that our current
stage of development is highly
transitional and that you know you go
back for the last four and a half
billion years the planet was dumb
essentially if you go back uh last few
thousand years there was a civilization
but it wasn't really producing any Techo
signatures and then over the last maybe
hundred years there's been something
that might be detectable from afar but
we're potent approaching this curp where
we might imagine it I mean we we
thinking of like maybe years and decades
with AI development typically when we
talk about this but as an astronomer I
have to think about much longer time
scares of centuries Millennia millions
of years and so if this if this wave
continues over that time scale which is
still the blink of an eye on a cosmic
time scale that implies
that everything will be AI essentially
out there if this is a common behavior
and so that's intriguing because it sort
of implies that we are uh special in in
terms of Our Moment In Time as a
civilization which it normally is um
something we're averse to as astronomers
we we normally like this mediocrity
principle we're not special we're a
typical part of the universe some the
cosmological principle but in a temporal
sense we may be in a unique location and
perhaps that is part of the a solution
to the firmy Paradox in fact that if it
is true that planets tend to go through
basically three phases is dumb life for
the vast majority a a brief period of
biological intelligence and then an
extended period of artificial int
intelligence that they transition to
then we would be in a unique and special
moment in Galactic history that would be
of particular interest for any
Anthropologist out there in the galaxy
right this would be the time that you
would want to study civiliz a
civilization very carefully you wouldn't
want to interfere with it you would just
want to see how it plays out kind of
similar to the ancestor simulations so
sometimes start up with the simulation
argument that you are able to observe
perhaps your own Origins and study how
the transformation happens and so yeah
that has for me recently been throwing
the fing Paradox a bit on its head and
this idea of the the zoo hypothesis that
we may be monitored which has for a long
time been sort of seen as a fringe idea
even amongst the seti community but if
we live in this truly transitional
period it it adds a lot of impetus to
that idea I think well even AI itself
would by its very nature would be
observing Us by you know it's like uh
human there used to be this concept of
human computation which is actually
exactly what's feeding the current chat
uh language models which is leveraging
all the busy stuff we're doing to do the
hard work of learning so like uh the
language models are trained on human
interaction in human language on the
internet and so it would AI feeds on the
output of brain power from humans MH and
so like it would be observing and
observing and it gets stronger as it
observe so it actually gets extremely
good at observing humans and one of the
interesting philosophical questions that
starts percolating is what makes us what
is the interesting thing that makes us
human
we tend to think of it uh and you said
like there's three phases what's the
thing that's hard to come by in phase
three is it something like scarcity
which is limited resources is it
something like Consciousness is that the
thing that's very what um that emerged
The evolutionary process in biological
systems that are operating under
constrained
resources this thing that feels that it
feels like something to experience the
world which we think of as Consciousness
is that really difficult to replicate is
in in artificial systems is that the
thing that makes it fundamentally human
or is it just a side effect uh that we
attribute way too much importance to do
you do you have do you have a
sense if you look out into the future
and AI systems are the ones that are
traveling out there to Alpha centory and
Beyond do you think they have to carry
the the flame of Consciousness with
them no not necessarily um they they may
do but they may it may not be and
necessarily I mean there I guess we're
talking about the difference here
between sort of an AGI artificial
general intelligence or Consciousness
which are distinct ideas and you can
certainly have one without the other so
I could imagine I would I would disagree
with this certainly in that statement
okay okay I I I think it's very possible
in order to have intelligence you have
to have consciousness
okay well I mean to to a certain degree
chat gbt 3 has a level of intelligence
already it's not a general intelligence
but it it displays properties of
intelligence with with no consciousness
so again I would disagree okay okay well
I I don't I don't I don't know I because
you said it's very nicely you said it
displays properties of
intelligence in the same way it displays
properties of intelligence I would say
it's starting to display prop properties
of Consciousness it certainly could fool
you that it's conscious correct yes
there I guess like a a cheing test
problem like if it's displaying all
those properties if it if it quacks like
a parrot looks like a parrot or quacks
like a duck things like isn't it isn't
it basically a duck at that point so
yeah I can I can see that argument um it
probably it I mean certainly as I tried
to think about it from the observer's
point of view as an astronomer what am I
looking for whether that intelligence is
conscious or not has little bearing I
think as to what I should be looking for
when I'm trying to detect evidence of
them it would maybe affect their
behavior in ways that I can't predict um
but that's again getting into the game
of what I would call xenos psychology of
trying to make projections about the
motivations of an alien species is
incredibly difficult and similar for any
kind of artificial intelligence it's
unfathomable what it intentions may be I
mean I would sort of question whether it
would even be interested in traveling
between the stars at all if its primary
goal is computation computation for the
sake of
computation then it's probably going to
have a different way of you know it's
going to be engineering its Soler system
and the nearby material around it for
for a different goal if it's just simply
trying to increase computer substrate
Across the
Universe and that of course if that is
its principal intention to just
essentially convert dumb matter into
smart matter as it goes then I think
that would come into conflict with our
observations of the universe right
because the the Earth shouldn't be here
if that were true the Earth should have
been transformed into computer substrate
by this point there has been plenty of
time yeah in the history of the Galaxy
for that to have happened um so I'm
skeptical
that we can uh I'm skeptical in the part
that that that's a behavior that AI or
or any civilization really engages in
but I also find it difficult to find a
way out of
it to to explain why that would never
happen in the entire history of the
Galaxy amongst potentially if life is
common Millions maybe even billions of
instant instantiations of AI could have
occurred across the Galaxy um and so
that seems to be a knock against the
idea that there is life else or
intelligent life elsewhere in the in the
Galaxy the fact that that hasn't
occurred in our history is maybe the
only solid data point we really have
about the activities of other
civilizations of course the scary one
could be that um we just at this stage
intelligent alien civilizations just
start destroying
themselves it just it becomes too
powerful everything's just too many
weapons too many nuclear weapons too
many nuclear weapon style systems that
just from mistake to aggression to like
the probability of self-destruction is
too high relative to the challenge of of
avoiding the technological challenges of
avoiding
self-destruction you mean the the AI
destroys itself or we destroy prior to
the Advent of AI as we get smarter and
smarter
AI um either AI destroys us or other
there could be just a million like AI is
correlated the development of AI is
correlated with all this other te
technological innovation uh genetic
genetic engineering like all kinds of
engineering at the Nano
scale Mass manufacturer of things that
could destroy us or cracking physics
enough to have very powerful weapons
nuclear weapons all of it just too much
physics enables way too many things that
can destroy
us before it enables the um the
propulsion systems that allow us to fly
far enough away before we destroy
ourselves so maybe that's what happens
to the other alien civilizations is that
your resolution because I I mean I think
us in the techos signature community and
theic Community aren't thinking about
this problem seriously enough in my
opinion we should we should be thinking
about the what AI is is is doing to our
society and the implications what we're
looking for and so the only I think part
of this thinking has to involve people
like yourself who are more intimate with
the machine learning and artificial
intelligence world is your how do you
reconcile in your mind you said earlier
that you think you can't imagine a
Galaxy where life and intelligence is
not all over the place and if artificial
intelligence is a natural progression
for
civilizations how do you reconcile that
with with the absence of any information
around us or any clues or hints of
artificial Behavior artificially
engineered stars or colonization
computer substrate transformed planets
anything like that it's it's uh
extremely difficult for me it's the the
firmy Paradox broadly defined is
extremely difficult for me and the the
terrifying thing is one thing I suspect
is that we keep destroying ourselves the
probability of self-destruction with
with advanced technology is just
extremely high that's why we're not
seeing it
m but then again my intuition bu about
why we haven't blown ourselves up with
nuclear
weapons it it's very surprising to me
from a scientific perspective yeah it
doesn't given all the cruelty I've seen
in the world um given the the the power
that nuclear weapons placed in the hands
of very small number of individuals it's
very surprising to me we destroy
ourselves and it seems to be a very low
probability situation we have happening
here um but and then the other
explanation is the is the zoo is the
observation that we're just being
observed that's the that's the only
other thing it's just it's so difficult
for
me um of course all of science
everything is very humbling it would be
very humbling for me to learn that we're
alone in the universe it would
change you know what it maybe I do want
that to be true because you want us to
be special that's why I'm resisting that
thought maybe there's no way we're that
special there's no way we're that
special that's that's that's where my
resistance comes from I I would just say
you know the specialness is something we
we in implicitly in that statement
there's kind of an assumption that we
are something positive like we're a gift
to this planet or something and that
makes it special but you know it may be
that intelligence is more of is like
we're like rats or cockroaches we're an
infestation of this planet we're not
we're not some benevolent property that
the planet would Planet would ideally
like to have if you can even say such a
thing but we we may be not only a
generally a negative Force for a
planet's biosphere and its own
survivability which I think you can make
a strong argument about but we may also
be a very persistent infestation that
may even in you know interesting
thoughts there in the wake of a nuclear
war would there be an absolute
eradication of every human being which
would be a fairly extreme event or would
the candle of Consciousness as you might
call it the flame of Consciousness
continue with some small Pockets that
would maybe in 10,000 years 100,000
years we' see civilization reemerge and
play out the same thing over again yeah
that's certainly but nuclear weapons
aren't powerful enough yet but yes the
uh but to sort of push back on the
infestation sure but the word special
doesn't have to be positive I just mean
I think it tends to imply but I take
your point yeah but maybe
um just maybe extremely rare might be
yeah and that to me it just it's it's
very
strange for me to be cosmically unique
it's just very strange I I I mean that
we're the only thing of this level of
complexity in the Galaxy just seems very
strange to me I I would just yeah I as
said I do think it depends on this
classific ation I think there is sort of
again it's kind of buried within there
as a subtext but there is a a
classification that we're doing here
that what we are is a distinct category
of of life let's say in this case when
we're talking about intelligence we are
something that can be
separated um but of course we see
intelligence across the Animal Kingdom
in you know dolphins hbat whales um
octopuses crows Ravens and so it's quite
possible that um
that these are all manifestations of the
same thing and we are not uh we are not
a particularly distinct class except for
the fact we make technology that's
really any difference to our
intelligence and we we classify that
separately but from a biological
perspective to some degree it's really
just all part of a Continuum and so
that's why I when we talk about unique
you're you you are P putting yourself in
a box which is distinct and saying this
is the only example of things that fall
into this box but the but the walls of
that box May themselves be a construct
of our own arrogance that we are
something distinct yeah and uh but I was
also speaking broadly for us meaning all
life on
Earth that but then it's possible that
there's all kinds
of living uh ecosystems in on other
planets and other moons that just don't
have interest in technological
development mhm and may maybe May
technological development is the the the
parasitic thing it destroys the organism
broadly and
then maybe that's actually one of the
fundamental realities whatever broad way
to categorize technological development
that's that's just a parasitic thing
that just destroys itself it's a cancer
you know we're flirting around sorry to
interrupt we're flirting around this
idea of the great filter a little bit
here so we be asking where is this does
it lie ahead of us nuclear war maybe
imminent that would be a filter that
ahead of us or could it be behind us and
that it's the Advent of technology that
is genuinely a rare occurrence in the
universe and that explains the FY
Paradox um and so that's uh that's
something that obviously people have
debated and gone argued about in set for
decades and decades but it remains a a
persistent people argue whether it
should be really called a paradox or not
but it remains a consistent apparent
contradiction that you can make a very
Cent argument as to why you expect life
and intelligence to be common in the
universe and yet everything everything
we know about the universe is fully
compatible with just us being here and
that's a haunting thought but um I'm not
I have no preference or desire for that
to be true I'm not trying to impose that
view on anyone but I do ask that we
remain open-minded until evidence has
been collected either way well the thing
is
it's one of if not the probably I would
argue it's the most important question
facing human civilization or the most
interesting yeah I I think
scientifically speaking like what
question is more
important than um they
somehow you know there could be other
ways to sneak up to it but it gets to
the essence
of what we are what these living
organisms are is somehow seeing Another
Kind yeah helps us understand it speaks
to The Human Condition helps us
understand what it is to be human to
some degree um I think you know I I have
tried to mean remain very agnostic about
the idea of life and intelligence one
thing I try to be more optimistic about
and I've been thinking a lot with our
searches for life in the universe is
life in the
past you can I think it's actually not
that hard to imagine we are the only
civilization in the galaxy right now
living yeah that's that's currently
extent but there may be very many
extinct civilizations if each
civilization has a typical lifetime
comparable to let's say AI is the demise
of our own that's only a few hundred
years of technological development or
maybe 10,000 years if you get back to
the ne ethic re Revolution the dawn of
Agriculture you know hardly anything in
Cosmic time span um that that's nothing
that's the blink of an eye and so it's
not surprising at all that we would
happen not to coexist with anyone else
but that doesn't mean nobody else was
ever here and if other civilizations
come to that same conclusion and
realization maybe they scour the Galaxy
around them don't find any evidence for
intelligence then they have two options
they can either give up on communication
and just say well it's never going to
happen uh we just may as well just you
know worry about what's Happening Here
on our own planet or they could attempt
communication but communication through
time mhm and that's that's almost um the
most selfless Act of communication CU
there's no hope of getting anything back
it's um a philanthropic gift almost to
that other civilization that you can
maybe maybe might just be nothing more
than a monument which the pyramids
essentially are a monument of their
existence that these are the things they
achieved this is their you know the
things they believed in their language
their culture or um it could be maybe
something more than that it could be
sort of lessons from what they learned
and their own history and so I've been
thinking a lot recently
about how would we send a message to
other civilizations in the future
because that act of thinking seriously
about the engineering of how your
designer would inform us about what we
should be looking
for and also perhaps be our best chance
quite frankly of ever making contact it
might not be the contact we dream of but
it's still contact they would there
would still be a record of our existence
as pitiful as it might be compared to a
two-way
communication and I love the humility
behind that project that Universal
project yeah it's uh sort of it's humble
and
the it uh humbles you to the the
vast temporal landscape with the
universe just realizing our like
day-to-day lives they all of us will be
forgotten mhm it's nice to think about
something that sends a signal out to
other um yeah it's it was almost like a
humility of acceptance as well of like
knowing that you have a terminal disease
but your impact on the earth doesn't
have to end with your death and it could
go on Beyond with what you leave behind
for others to discover with maybe the
books you write or what you leave in the
literature do you think launching the
Roadster vehicle out in
the Roadster um I'm not sure what
someone would make of that if
they yeah that's true um I mean there
have been quasi attempts at it beyond
the Roadster I mean there's like plaques
on there's the Pioneer plaques um
there's the Voyager to Golden record um
it's pretty unlikely anybody's going to
discover those uh because they're just a
drift in space and they they they will
eventually mechanically die and not
produce any signal for anyone to spot so
you'd have to be extremely lucky to come
across them
I've I've often said to my colleagues I
think the best place is the Moon the
Moon unlike the Earth has no significant
weathering the you know the how long
will the Apollo descent stages which are
still s on the lunar surface last for
the the only real effect is
micrometeorites which are slowly like
dust smashing against them pretty much
um but that's going to take Millions
potentially billions of years to erode
that down and so we have an opportunity
and that's on the surface if you put
something just a few meters beneath the
surface it would have even greater
protection and so it raises the prospec
of that if we wanted
to send something a significant amount
of information to a future Galactic
spanning Civilization that maybe cracks
the intercell propulsion problem the
moon's going to be there for five
billion years that's a long time for
somebody to come by and detect maybe a
strange pattern that we draw on the sand
for them to you know big Arrow big cross
like look into here and we could have a
tomb of knowledge of some record of our
civilization um and so I think it's uh
when you think like that what that
implies to us well okay the Galaxy's 13
billion years old the Moon is already 4
billion years old there may be places
familiar to Us nearby to us that we
should be seriously
considering as places we should look for
life and intelligent life or evidence of
relics that they might leave behind for
us so that thinking like that will help
us find such relics and it's like a it's
a a it's like a beneficial cycle that
happens yes yeah exactly that enables
the science of of study better like of
of searching for bi and Tech signatures
and so on yeah and it's inspiring I mean
it's it's it's it's it it's also
inspiring in that we want to leave a
legacy behind as an entire civilization
not just in the symbols but broadly
speaking yeah that's the last thing
somehow yeah and I'm part of a team
that's trying to re re repeat the golden
record experiment uh we're trying to
create like an open source version of
the golden record that future spacecraft
are able to download and basically put a
little hard drive that they can carry
around with them and you know get these
distributed hopefully across the solar
system eventually and going to be called
the hit hackers guy to the Galaxy or
could be that's a good name for it we've
we've been toying a little bit with name
but I think probably just be golden
record at this point or golden record
version two or something but um I think
uh I think another benefit that I see of
this activity is that it forces us as a
species to ask those questions about
what it is that we want another
civilization to know about us the Goden
record was kind of funny because it had
photos on it and it had photos of people
eating for instance um but had no photos
of people defecating mhm and so I was
thought that was kind of funny because
if I was if I was an alien yeah or if I
was studying an alien if I saw images of
an alien I would I'm not trying to be
like a perver or anything but I would
want to see the full bi I want
understand the biology of that alien and
so we we always censor what we what we
show um and we we should show the whole
actual natural process and then also say
we humans tend to censor these things we
tend to not like to walk around naked we
tend to not to talk about uh some some
of the natural biological phenomena and
talk a lot about others yeah and and
actually just be very uh like the way
you would be to a therapist or something
very transparent about the way we
actually operate this world I mean and
Sean had the Sean had that with the
golden record I think he he originally
there's a there's a male and a female
figure to pit on the golden record and
the the woman had a genitalia originally
drawn and uh there was a lot of push
back from I think a lot of Christian
groups who were not happy about the idea
of throwing this into space And So
eventually they had to remove that and
so it's it would be confusing
biologically if you're you know trying
to study xenobiology of of this alien
that apparently has no genitalia or the
man does but for some reason the woman
doesn't you know and that's our that's
our own uh societal and cultural um
imprint happening into that information
that's to be
fair just even having two sexes and
predators and prey just a whole that
could be just a very unique earthlike
thing so they might be confused about
why there's like pairs of things like
why are you like why why is there a man
and a woman in general like they they
could be I mean they could be confused
about a lot of things in general I don't
I don't think the they don't even know
which way to to hold the
picture or they is the picture they
don't they might not need they they
might have very different sensory
devices to even interpret this they only
you know have uh sound as their only way
of navigating the world it's kind of
lost just to send any kind of there been
a lot of conversation about sending
video and uh audio and uh video and
pictures and I've that's one of the
things I've been a little bit resistant
about in the team that I've been
thinking well they might have eyes and
so if you lived in um under the Europa
surface having eyes wouldn't be very
useful um if you lived in a on a very
dark planet on the tightly locked night
side of an exoplanet having eyes
wouldn't be particularly useful so it's
kind of a presumption of us to think
that video is a useful form of
communication do you hope we become a
multiplanetary species so we almost
sneaking up to that but um you know the
efforts of SpaceX of Elon maybe in
general what your thoughts are about
those efforts so you already mentioned
Starship will be very interesting for
astronomy for for science in general
just getting stuff out into space but
what about the longer term goal of
actually colonizing of building
civilizations on other surfaces on moons
on planets it seems like an a fairly
obvious thing to do for our survival
right there's a high risk if if we
are committed to trying to keep this
human human experiment going um putting
all of our eggs in one basket is always
going to be a risky strategy to pursue
it's a nice basket though but yeah it is
a beautiful basket I wouldn't want to I
personally have no interest in living on
mars or the moon I would like to visit
but I would definitely not want to spend
the rest of my life and die on Mars it's
a it mean it's a hell hole Mars is a
very very diff I think the idea this is
going to happen in the next you know 10
20 years is seems to be very
optimistic um not that it's in some
mountable but the the challenges are
extreme to survive on a planet like Mars
which is you know like a dry Frozen
desert um with a high radiation
environment it's it it's a challenge of
of a type never faced before so it's I'm
sure human Ingenuity can tackle it but
I'm skeptical that we'll have thousands
of people living on Mars in my lifetime
but I would I would relish that
opportunity to maybe one day visit such
a settlement and you know um do
scientific experiments on mars or
experience Mars uh do astronomy from
Mars you know all sorts of cool stuff
you could do um you know sometimes you
see these dreams of outter solar system
exploration and you can like fly through
the clouds of Venus or you could um just
do these enormous jumps on like these
small moons where you can essentially
jump as high as a skyscraper and
Traverse the mean so there's all sorts
of you know Wonderful ice skating on
Europa might be fun so d r i love the
idea of us becoming into planetry I
think it's um it's just a question of uh
time our own our own destructive
Tendencies uh as you said earlier are
add odds with our emerging capability to
become interplanet Tre and the question
is will we get out of the nest before we
burn it down and I I don't know I
obviously I hope that we do but I I
don't have any special Insight that
there there is a pro there is somewhat
of a
um an noring intellectual itch I have
with the So-Cal doomsday argument which
um I try not to treat too seriously but
there is some element of it that bothers
me uh the Dooms argument basically
suggests that you know you're typically
the mediocrity principle you're not
special that you're probably going to be
born somewhere in the middle of all
human beings who will ever be born
you're unlikely to be one of the first
1% of human beings that ever lived and
one of the last one and similarly the
last 1% of human beings that will ever
live because it'd be very unique and
special if that were true and so by this
logic you can sort of calculate um how
many generations of humans you might
expect so if there's been let's say 100
billion human beings that have ever
lived on this planet then you could say
to 95% confidence so uh you divide by 5%
so 100 billion divided by 005 would give
you two trillion human beings that would
ever live you'd expect by this argument
and so if each um if let's say each each
planet in general the planet has a 10
billion population so that would be 200
generations of humans we would expect
ahead of us and if each one has an
average lifetime is 800 years then that
would be about 20,000 years so there's
20,000 years left on the clock that's
like a typical doomsday argument type uh
that's how they typically lay it out um
now you can AR the a lot of the
criticisms that de so argument come down
to what are you really counting you're
counting humans there but maybe you
should be counting years or maybe you
should be counting human hours you know
how what are you because what you count
makes a big difference to what you get
out in the other end this is called the
reference class um and so that's one of
the big criticisms of the Doomsday
argument but I do think it has a
compelling point that it would be
surprising if our future is to one day
Blossom and become a Galactic spanning
Empire trillions upon trillions upon
trillions of human beings will one day
live across the stars for essentially as
long as the Galaxy exists and the Stars
Burn we would live at an incredibly
special point in that story we will be
right at the very very very beginning
and that's not impossible but it's just
somewhat improbable and so there's part
of that sort of um irks against me but
it also almost feels like a
philosophical argument because you're
sort of talking about souls being drawn
from this Cosmic pool um so it's it's
not an argument that I lose sleep about
for our fate of the Doomsday but it is
um somewhat intellectually annoying that
that there is a a slight contradiction
now it feels like with the idea of a
Galactic spanning
Empire and but of course there's so many
unnes I I for one would love to visit
even space but Mars just imagine
standing at Mars and looking back at
Earth yeah I
mean um the incredible site it would
give you such a fresh perspective as to
your entire existence and what it meant
to be human yeah and then come back to
Earth it would it would give you give
you a heck of a perspective plus the the
sunset on Mars is supposed to be nice I
loved what William Shatner said after
his flight um his words really moved me
when he came down and I think uh it it
really captured the idea that we
shouldn't really be sending uh Engineers
our scientists into space we should be
sending out poets because those are the
people when they come down who can who
can truly make a difference with when
they describe their experiences in space
and I found it very moving reading what
he what he
said yeah when you talk to astronauts
when they when they describe what they
see it's like
this like they've discovered a whole new
thing that they can't possibly convert
back into words yeah um yeah it's it's
beautiful to see just as a quick before
I forget I have to ask you um can you
summarize your argument against the
hypothesis that we live in a
simulation is it Sim similar to our
discussion about uh the Doomsday
Clock um no it's actually probably more
similar to my um agnosticism about life
in the universe and it's just sort of
remaining agnostic about all
possibilities um the simulation argument
sometimes it gets
um it mixed there's kind of two distinct
things that we need to consider one is
the probability that we live in
so-called Bas reality that we're not
living in a simulated reality itself and
another probability we need to consider
is the ility that that technology is
viable possible and something we will
ultimately choose to one day do those
are two distinct things they're probably
quite similar numbers to each other but
they are distinct probabilities so my in
my paper I I I wrote about this I just
tried to work through the problem I
teach Asos statistics actually teaching
it this morning and so it just seemed
like a fun case study of working through
a basing calculation Fred um Bas in
calculations work on conditionals and so
when you here you know what kind of
inspired this project was when I heard
musk said was like a a billion to one
chance that we don't live in a
simulation um he's right if you add the
basing conditional and the basing
conditional is as conditioned upon the
fact that we eventually develop that
technology and choose to use it or it's
it's it's chosen to be used by such
species by such civilizations that's the
conditional and you have to add that in
because that conditional isn't
guaranteed and so um in a basing
framework you can kind of Make That
explicit you see mathematically
explicitly that's a conditional in your
equation and the the opposite side of
the coin is basically um in the trilemma
that Bostrom originally put forward it's
options one and two so option one is
that you basically never develop the
ability to do that option two is you
never choose to execute that so we kind
of group those together as sort of the
uh the nonsimulation
uh scenario let's call it so you've got
non-simulation scenario simulation
scenario and agnostically we really have
to give the you know how do you assess
the model the a prior model probability
of those two scenarios um it's very
difficult and we can I think people
would probably argue about how you
assign those priors in the paper we just
assigned 50/50 we just said we this
hasn't been demonstrated yet there's no
evidence that this um is actually
technically possible but nor is it is
not technically possible so we're just
going to assign 50/50 problem to these
two hypotheses and then in the
hypothesis where you have a simulated
reality you have a base reality set at
the top so there is even in the
simulated hypothesis there's a
probability you still live in Bas
reality and then there's a whole Myriad
of universes beneath that which are all
simulated um and so you have a ve you
have a very slim probability of being in
base reality if this is true and you
have a 100% probability of living in
base reality on the other hand if it's
not true and we never develop that
ability or choose never to use it
and so then you apply this technique
called basy Model averaging which is
where you propagate the uncertainty of
your two models to get out a final
estimate and because of that one base
reality that lives in the simulated
scenario you end up counting this up and
getting that it always has to be less
than 50% so the probability Liv in in a
simulated reality versus BAS reality has
to be slightly less than 50% um now that
really comes down to that statement of
giving it 50/50 odds to begin with and
on the one hand you might say look David
I'm you know I work in artificial I'm
very confident that this is going to
happen just of extrapolating of current
trends or on the other hand a
statistician would say um you're giving
way too much uh weight to the simulation
hypothesis because it's an intrinsically
highly complicated model you have a
whole hierarchy of realities within
realities within realities it's like the
Inception style thing right and so this
requires hundreds thousands millions of
parameterizations to describe
and by aam's razor we would always
normally penalize inherently complicated
models as being disfavored so I think
you could argue on being too generous or
too kind with that but I sort of want to
develop the the rigorous mathematical
tools to explore it and ultimately it's
up to you to decide what you think that
50/50 odds should be but you can use my
formula to plug in whatever you want and
get the answer and I use 50/50 so and
but when in that first pile uh with the
first two parts parts of the the the
that the bostom talks about it seems
like connected to that is the question
we've been talking about which is the
number of times at bat you get which is
the number of intelligent civilizations
there out there that can uh build such
simulations that it seems like very
closely connected cuz if we're the only
ones that are here and can build such
things that changes things yeah yeah I
mean this yeah the simis has all sorts
of applications like that um I've always
love Sean car pointed out a really
interesting contradiction apparently
with the simulation hypothesis that I
speak about a little bit in the paper
but he showed that um or or pointed out
that in this hierarchy of realities
which then develop their own AIS within
the realities and then they or or really
ancestor simulations I should say rather
than AI they develop their own
capability to simulate realities you get
this hierarchy and So eventually
there'll be a bottom layer um which I
often call the Sue of reality is like
the worst layer where it's the most
pixelated it could possibly be right so
cuz each layer is necessarily going to
have less competitional power than the
layer above it because not only are you
simulating that entire planet but also
some of that's being used for the the
computers themselves that those are
simulated and so that base reality or
sorry the B the Sue of reality is a is a
is a reality where they are simply
unable to produce ancestor simulations
because the Fidelity of the simulation
is not sufficient and so from their
point of view it might not be obvious
the universe is pixelated but they would
just never be able to manifest that
capability what if they're constantly
simulating uh cuz it in order to uh
appreciate the limits of the Fidelity
you have to have an observer what if
they're always simulating a dummer and
Dumber Observer yeah what if the sewer
has very dumb observers they can't like
scientists that are the dumbest possible
scientist so like it's it's very
pixelated but the scientists are too
dumb to to even see the the
pixelations that that's like built into
the universe always has to be a
limitation on the cognitive capabilities
of the complex systems that are within
it yeah so that se of reality they would
still presumably be able to have a a
very impressive computational
capabilities they' probably be able to
simulate Galactic formation all this
kind of impressive stuff but they would
be just short of the ability to however
you define it create a truly sensient
conscious experience in a computer that
would just be
just beyond their capabilities and so uh
Carol pointed out that if you add up all
the you know you count up how many
realities there should be
probabilistically if this is true over
here the simulation uh hypothesis or
scenario then you're most likely to find
yourself in the sewer because there's
just far more of them than there are of
any of the higher levels oh and so that
sort of sets up a contradiction because
then you live in a reality which is
inherently Inc capable of ever producing
ancestor
simulations but the premise of the
entire argument is that ancestor
simulations are possible so there's
there's there's a contradiction that's
there's that there's that old quote
we're all living in the sewer but some
of us are looking up at the
stars this this is maybe more true than
we
think uh to me so there's of course
physics and computational fascinating
questions here but to me there's a
practical psychological question which
is you know how do you create a virtual
reality
world that um is as compelling and not
necessarily even as realistic but almost
as
realistic but as compelling or more
compelling Than Physical
reality because something tells me it's
not it's not very difficult in the in a
in um full history of human civilization
that that is an interesting
kind of simulation to me because that
feels like it's doable in the next 100
years creating a world where we're all
prefer to live in the digital world MH
and not like a visit but like it's like
your scene is insane no like you're
required it's unsafe to live outside of
the virtual world and uh it's
interesting to me from an engineering
perspective how to build that because
I'm somebody that sort of loves video
games and it seems like you can create
incredible worlds there and stay there
and uh that's a it's a
different question than creating a ultra
high resolution High Fidelity simulation
of physics but if that world inside a
video game is as consistent as the
physics of our reality you can have your
own scientists in that world that trying
to understand that physics World it
might look different
presum they'd eventually forget you know
give it give it long enough they might
forget about their origins of being once
biological and assume this was their
only reality especially if you're now
born you know uh well certainly if
you're born but even if you're 8 years
old or something when you first started
wearing the headset yeah or you could
have a memory wipe when you go in I mean
it it also kind of maybe speaks to this
issue of like neuralink and how do we
keep up with AI in our world if you want
to augment your intelligence um perhaps
one way of competing and the one of your
impetuses for going into this digital
reality would be to be competitive
intellectually with um artificial
intelligences that you could trivially
augment your reality if your brain was
itself artificial but I mean one one
skeptism I've always had about that is
is whether it's more philosophical
question but how much is that really you
if you do a mind upload is this just a
duplicate of your memories that thinks
it it's you versus truly a transference
of your conscious stream into that
reality and I think when you
uh it's almost like the teleportation
device in Star Trek um but with
teleportation quantum teleportation you
can kind of rigorously show that um that
you know all as long as all of the
quantum numbers are exactly duplicated
as you transfer over it truly is from
the University's perspective um in every
way indistinguishable from what was
there before it really is in principle
you and all the sense of being you
versus creating a a duplicate clone and
uploading memories uh to that human body
or a computer that would surely be uh a
discontinuation of that conscious
experience by virtue of the fact you've
multiplied it and so I I would be
hesitant about uploading for that reason
I would see it mostly As is my own
killing myself and having some um AI
duplicate of me that persists in this
world but is not truly my experience
typical 20th century
human with with an attachment to this
particular singular instantiation of
brain and
body how silly humans used to be used to
have rotary phones and
um and and other silly things um you're
an incredible human being you're an
educator you're a researcher um you have
like an amazing uh YouTube
channel looking to young people if you
were to give them
advice how can they have a a career that
maybe is inspired by yours um inspired
by wandering curiosity a career they can
be proud of or a life they can be proud
of what advice would you
give I certainly think in terms of a a
career in science one thing that I maybe
discovered late but has
been incredibly influential on me in
terms of my own happiness and my own um
productivity has been this Synergy of
doing two passions at once one passion
in science communication and other
passion research and not surrendering
either one and and I think that tends to
be seen as something that's an either or
you have to completely dedicate your
yourself to one thing to gain Mastery in
it that's a conventional way of thinking
about both science and other disciplines
and I have found that both have been
elevated by practicing an each um and I
think that that's true in all assets of
life I mean if you want to become the
best researcher you possibly can you're
pushing your intellect and a sense your
body to a high level and so to me I've
always wanted to couple that with
training of my body training of my mind
in other ways besides from just what I'm
doing when I'm in the lecture room or
when I'm in my office you know
calculating something um focusing on
your own development through whatever it
is meditation for me is often running
working out um and pursuing multiple
passion
provides this uh almost synergistic
Bliss of all of them together so often
I've had some of the best research ideas
from making a YouTube video and trying
to communicate an idea or interacting my
audience who've had a question that
sparked a whole trail of thought that
led down this wonderful intellectual
Rabbit Hole or maybe to a new
intellectual Discovery can go either way
sometimes with those things um and so
thinking broadly
diversely and always looking after
yourself in this uh in this highly
competitive and often extremely
stressful world that we live in um is
the best advice I can offer anybody and
just try if you can to it's very cheesy
but if you can follow your passions
you'll always be happy um trying to sell
out for for the quick cash out for the
quick Bookout um can be tempting in the
short term looking for exomoons was
never was never easy but I made a career
not out of discovering exomoons but out
of learning how to communicate the
difficult problem and discovering all
sorts of things along the way you know
we shot for the sky and we discovered
all this stuff along the way we
discovered dozens of new planets using
all sorts of new techniques um we push
this instrumentation to new places and
I've had an extremely productive uh
research career in this world I've had
all sorts of ideas working on techno
signatures it's it's you know thinking
innovatively pushes you into all sorts
of exciting directions um
so just just try to yeah it's hard to
find that passion but you you can
sometimes remember it when you were a
kid what your passions were and what
what fascinated you as a child for me as
soon as I picked up a space book when I
was 5 years old that was it I was hooked
on space and I almost betrayed my
passion at College I studied physics
which I've always been fascinated by
physics as well but I came back to
astronomy because it was my first love
and I was much happier doing research in
astronomy than I was in physics because
it spoke to that wonder I had as a child
that first was a spark of curiosity for
me in
science so Society will try to get you
to look at hot Jupiter's yeah and the
advice is to look for the cool worlds
instead uh what do you think is the
meaning of this whole thing you ever ask
yourself
why it's just a ride that's how I it's
just a ride run roller coaster and we
have no purpose it's an accident in my
my perspective there's no meaning to my
life there's no objective uh deity who
is overwatching what I'm doing and I'm I
have some fate or destiny it's all just
WR riding on the roller coaster and
trying to have a good time and and and
contribute to to other people's
enjoyment of the ride yeah try try try
to make it a happy uh Happy accident
yeah yeah I I I see no fundamental um
Providence in in my life or in the
nature of the universe and you just see
this universe is this beautiful Cosmic
accident of galaxies smashing together
Stars forging here and there and planets
occasionally spawning maybe life Across
the Universe um and we are just one of
those instantiations and we should just
enjoy this very brief episode that we
have and I think trying to look at it
much deeper than that is
um is to me uh it's not very Soul
satisfying I just think enjoy what
you've got and appreciate it it does
seem noticing that
beauty um helps make the ride pretty fun
yeah absolutely David you're an
incredible person I I I haven't covered
most of the things I wanted to talk to
you about this was an incredible
conversation I I just I'm glad you exist
I'm glad glad you're doing everything
you're doing and I'm a huge fan thank
you so much for talking today this was
amazing thank you so much Lex it's real
honor thank you thanks for listening to
this conversation with David Kipping to
support this podcast please check out
our sponsors in the description and now
let me leave you with some words from
Carl Sean perhaps the aliens are here
but are hiding because of some Lex
Galactica some ethic of non-interference
with emerging civilizations we can
imagine them curious and dispassionate
observing us as we would watch a
bacterial culture in a dish to determine
whether this year again we manag to
avoid
self-destruction thank you for listening
and hope to see you next time