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Language: en
there's no reason to think that the
ocean ends just beyond your Horizon and
likewise there's no reason to think that
the aftermath of our big bang um ends
just at the boundary of what we can see
indeed there are quite strong arguments
um that it probably goes on about 100
times further it may even go on so much
further that uh all comori are
replicated and uh there's another set of
people like us sitting in in a room like
this
the following is a conversation with
Lord Martin reee ameritus professor of
cosmology and astrophysics at Cambridge
University and co-founder of the center
for the study of existential risk this
is the Lex Freedman podcast to support
it please check out our sponsors in the
description and now dear friends here's
Martin
reys in your 2020 Scientific American
article you write that quote today we
know that the universe is far bigger and
Stranger than anyone suspected so what
do you think are the strangest maybe the
most beautiful or maybe even the most
terrifying things lurking out there in
the cosmos well of course we're still
groping for any detailed understanding
of the remote parts of the universe but
of course what we've leared in the last
few decades is really two things first
we've understood that the Universe Had
An Origin about 13.8 billion years ago
in a so-called big bang a hot Den state
whose very Beginnings are still shrouded
in mystery and also we've learned more
about the extreme things in it black
holes neutron stars explosions of
various kinds and one of the most
potentially exciting discoveries in the
last 20 years mainly in the last 10 has
been the realization that most of the
stars in the sky are orbited by resu of
planets just as the sun is orbited by
the Earth the other familiar planets and
this of course makes the night sky far
more interesting what you see up there
aren't just points of light but they're
plany systems and that raises the
question could there be life out there
and so that is an exciting problem for
the 21st century so when you see all
those lights out there you immediately
imagine all the planetary worlds that
are around them and they potentially
have all kinds of different lives living
organisms life for forms or his that we
don't know at all we know that these
planets are there we know that they have
masses and um orbits rather like the
planets of our solar system but we don't
know at all if there's any life on any
of them I mean it's entirely logically
possible that life is unique to this
earth doesn't exist anywhere on the
other hand uh it could be that the
origin of life is something which
happens routinely given conditions like
the young Earth in which case there
could be literally billions of places in
our galaxy where some sort of biosphere
has evolved and settling um where the
truth lies between those two extremes is
a challenge for the coming decades so
certainly we're either lucky to be here
or very very very lucky to be here I
guess that's the difference uh where do
you fall your own estimate your own
guess on this question are we alone in
the universe do you think I think it
would be foolish to give any firm
estimate because we just don't know and
that's just a example of how we are
depending on greater observations and
also incidentally in the case of Life
we've got to take account of the fact
that uh as I always say to my scientific
colleagues biology is a much harder
subject than physics and most of the um
Universe we know about could be
understood by physics but uh we've got
to remember that even the smallest
living organism an insect is far more
complicated with layer on complexity uh
than uh the most complicated star or
Galaxy you know that's the funny thing
of about physics and biology the dream
of physicist in the 20th century and
maybe this century is to discover the
theory of everything and there's a sense
by that once you discover that theory
you will understand everything if we
unlock the mysteries of how the universe
works would we be able to understand how
life emerges from that fabric of the
universe that we understand I think the
phrase Theory of Everything is very
misleading because it's used to describe
a theory which unifies the um three laws
of microphysics electrity magnetism and
the weak interaction with gravity so
it's important step forward for particle
physicists but the lack of such a theory
doesn't hold up any other scientists
anyone doing biology or most of physics
is not held up at all through not
understanding subnuclear physics they're
held up because they're dealing with
things that are very
complicated and that's especially true
of anything biological so what's holding
up biologists is not a lack of a
so-called Theory of Everything uh it's
the inability to understand things which
are very complicated what do you think
we'll understand first how the Universe
works or how the human body works deeply
like from a fundamental deep level well
I think um perhap we can come back to it
later that there are only limited
prospects of ever being able to
understand with un AG's human brains the
most fundamental theories linking
together all the forces of nature I
think that may be a limitation of the
human brains um but I also uh think that
um we can perhaps aided by computer
simulations um understand a bit more of
the complexity of nature but uh even
understanding a simple organism from the
atom up is very very difficult and I
think extreme
reductionists have a very misleading
perception they tend to think that um in
a sense we're all solutions of thring
equation Etc um but that isn't the way
we'll ever understand anything uh it may
be true that we our reductions in the
sense if we believe that that's the case
we don't believe in any special life
force in living things but nonetheless
no one thinks that we can understand a
living thing by solving sh's equation to
take an example which isn't as
complicated lots of people study the
flow of fluids like water why waves
break why flows go turbulent things like
that this is a serious branch of Applied
Mathematics and engineering and in doing
this have concepts of viscosity
turbulence and things like that now you
can understand quite a lot about how
water behaves and how waves break in
terms of those Concepts but the fact
that any breaking wave is a solution of
tring's equation for 10 of 30
particles even if you could solve that
which you clearly can't would not give
you any insight so the important thing
is that every science has its own
reducible
Concepts in which you get the best
explanation uh so it may be in chemistry
it's things like veence um in biology
the concept in cell biology um and in
the ecology there are Concepts like
imprinting Etc and in Psychology there
are other Concepts so in a sense The
Sciences are like a tall building where
you have basic physics the most
fundamental then the rest of physics
then chemistry then cell biology Etc all
the way up to the I guess Economist in
the penthouse and all that um and we
have that um and that's true in a sense
but it's not true that it's like a
building in that it's made unstable by
an unstable base because if you're
chemist biologist or Economist you're
facing challenging problems but they're
not made any worse
by uncertainty about subnuclear
physics and at every level just because
you understand the rules of the game or
have a some understanding of the rules
of the game doesn't uh mean you know
what kind of beautiful things that game
creates right so if you're interested in
um birds and how they fly uh then things
like uh um
imprinting the baby on the mother and
all that and uh things like that are
what you need to understand um you
couldn't even in principle solve this
vertical equation how an albatross
wanders for thousands of miles of the
Southern Ocean and comes back and then
coughs up food for its young uh that
that's something we can understand in a
sense and uh predict the behavior but
it's not because we can solve it on the
atomic scale you mentioned that there
might be some fundamental limitation to
the human brain yes that limits our
ability to understand understand some
aspect of how the universe works that's
really interesting that's sad actually
if if if to the degree it's true it's
sad so what do you mean by that I would
simply say that just as um a monkey
can't understand quantum theory even
Newtonian physics um there's no
particular reason why the human brain
should have evolved to be well matched
to understanding a deepest aspect of
reality and I suspect that there may be
aspects that we not even aware of and
couldn't really fully comprehend um but
as an intermediate step towards that one
thing which I think is very interesting
possibility is the extent to which AI
can help us I mean I think uh if you
take the example of uh So-Cal theories
of everything one of which is string
theory um String Theory involves very
complicated geometry and structures in
dimensions and it's certainly in my view
on the cards
that the
physics of 10
Dimensions they very complicated
geometry um may be too hard for a human
being to work through but could be
worked through by an AI um with the
advantage of the huge processing power
which enables them to learn World
Championship chest within a few hours
just by watching games so there's every
reason to expect that these um
machines could help us to solve these
problems and of course if that's the way
we came to understand where the string
theory was right um it would be in a
sense frustrating because you wouldn't
get the sort of aha Insight which is the
greatest satisfaction from doing science
but on the other hand if um a machine
CHS away a 10-dimensional geometry
figuring out all the possible origami in
wound up in extra Dimensions if it comes
out at the end
spews out the correct mass of the
electron the fact that there are three
kinds of neutrinos something like that
you would know that there was some truth
in the theory and so we may have a
theory which we come to trust because it
does predict things that we can observe
and check but we may never really
understand the full workings of it to
the extent that we do more or less
understand um how um most phenomena can
be explained in a f Way of course in
case of quantum theory many people would
say understandably there's still some
Mysteries you don't quite understand why
it works but there could be deeper
Mysteries when we get to these unified
theories where there's a big gap between
um what a computer can print out for us
at the end and what we can actually
grasp and think through in our heads
yeah it's interesting that the idea that
there could be things a computer could
tell us that is
true and maybe you can even help us
understand why it's true a little bit y
But ultimately it's still a long journey
to really deeply understand the wise of
it uh yes and that's the limitation of
our brain we we can try to sneak up to
it in different ways given the
limitations of our brain have you I've
gotten a chance to spend the day a deep
mind talk to Demis habis his big dream
is to apply AI to the questions of
science certainly to the questions of
physics have you gotten a chance to
interact with them well I know him quite
well I've uh he's one of my heroes
certainly and and I remember I'm sure he
would say the same and I remember the
the first time I met him he said that he
was like me he wanted to understand the
universe but he thought the best thing
to do was to try and develop Ai and then
with the help of AI he'd stand more
chance of understanding the universe
yeah and I think he's right about that
so and of course um although we're
familiar with the way his computers
played go and chess um he's already made
contribution to science through uh uh
understanding protein folding better
than the best human chemists and so
already he's on the path to showing ways
in which computers have the power to
learn and do things by having ability to
analyze enormous samples in a short time
uh to do better than humans and so um I
think he would resonate for what I've
just said that it may be that uh in
these other fundamental questions the
computers will play a crucial role yeah
and there also doing uh quantum
mechanical simulation of electrons
they're doing uh control of uh high
temperature plasma Fusion reactors yes
that's a new thing which is very
interesting they can suppress the
instabilities in these toac um better
than any other way yeah and it just the
march of progress by AIS and science is
is is making uh big strides do you think
an AI system will win a Nobel Prize in
the century what do you think
and does that make you sad if I can
digress and put in a plug for my next
book yes it has a chapter saying why
Nobel prizes do more harm than good yes
so on a quite separate subject I I think
Nobel prizes do great of damage to the
perception of the way science is done of
course if you ask who or what deserves
the credit for any scientific discovery
it maybe often someone has an idea a
team of people who work a big experiment
Etc
um and of course it's the quality of the
equipment which is um crucial and
certainly in the subjects I do in
astronomy um the huge advances we've had
uh come not from us being more
intelligent than Aristotle was but
through us having far far better uh data
um from powerful telescopes on the
ground and in space and also
incidentally uh we benefited hugely in
astronomy uh from um Compu simulations
because um if you
are a subatomic physicist then of course
you crash together the particles in a
big accelerator like the one at CERN and
see what happens but um I can't crash
together to galaxies or two stars and
see what happens but in the virtal world
of a computer one can do simulations
like that and the power of computers is
such that these simulations uh can um
yield um a phenomena and insights which
we wouldn't have guessed beforehand and
the way we can feel we're making
progress in trying to understand some of
these phenomena why galaxies have the
size and shape they do and all that is
because we can do simulations um
tweaking different initial conditions
and seeing which gives the best fit to
what we actually observe and so that's a
way in which we've made progress in
using computers and incidentally uh we
also now need them to analyze data
because one thinks of astronomy as being
traditionally rather data poor subjects
but the um European satellite called
Gaia has just put on line the um speeds
and colors and properties of nearly two
billion stars in the Milky Way and which
you can do fantastic analysis of and
that of course could not be done at all
without just the number crcy capacit
computers and the the new methods of
machine learning actually love of raw
data the kind that astronomy provides
organized structured raw data yeah well
indeed because the reason they really
have a benefit over us is that they can
learn and think so much faster that's
how they can learn to play chess and go
that's how they can learn to diagnose
lung cancer better than a radiologist
because they can look at 100,000 scans
in a in a few days whereas no human
radiologist sees that many in a lifetime
well
there's still magic to the human
intelligence to the intuition to the
common sense reasoning uh well we hope
so for now what what what is the new
book that you mentioned the book I me
it's called if science is to save us
it's coming out in September um and it's
on the um well the big challenges of
science um you um climate dealing with
the bio bios safety and dealing with
cyber safety and also it's got chapters
on the um way science is organized
universities andies Etc and and the the
ethics of Science and
um and perhaps the limit and the limits
yes yeah well let me actually just
stroll around the the beautiful and the
strange of the universe uh over 20 years
ago you hypothesized that we would solve
the mystery of dark matter by now so
unfortunately we didn't quite yet MH
uh first what is dark matter and why has
it been so tough to figure out well I
mean we we learned that galaxies and
other large scale structures which are
moving around but uh um preventive
flying apart by G by gravity um would be
flying apart if they only contain the
stuff we see if everything in them was
shining and to understand how Galax is
formed and why they do remain confined
the same size uh one has to infer that
is about five times as much stuff
producing gravitational forces than the
total amount of stuff in the gas and
stars that we see and that stuff is
called Dark Matter um that's his leading
name it's not dark it's just transparent
Etc um and the uh most likely
interpretation is that it's a swarm of
uh microscopic particles which have no
electric charge and the very small
crosssections are hitting each other and
hitting anything else so they swarm
around and we we can detect their
Collective effects and when we do
computer simulations of how galaxies
form and evolve and how they emerge from
The Big Bang then uh we get a nice
consistent picture if we put
in five times as much mass in the form
of these mysterious dark particles and
for instance it works better if we think
they're non- interacting particles than
if you think they're a gas which would
have shock waves and things so we know
something about the properties of these
but we don't know what they are and um
the disappointment compared to my guess
20 years ago um is that particles
answering this description have not yet
been found it was thought that the big
accelerator the lar handro collider at
Ser which is the world's biggest might
have found a new class of particles
which would have been the obvious
candidates and it hasn't and uh um some
people say well Dark Matter can't be
there Etc but what I would argue is that
there's a huge amount of parameter space
that hasn't been explored um there are
other kinds of particles called Axion
which behave slightly differently which
are a good candidate um and um there's a
factor of 10 power of 10 between the
heaviest particles that could be created
by the large hydron cider and the
heaviest particles which on theoretical
grounds could exist without turning into
black holes so there's a huge amount of
possible particles which could be out
there as remnants of the Big Bang but
which we wouldn't be able to te so
easily so um the fact that we've got new
constraints on what the Dark Matter
could be doesn't diminish my belief that
it's there in the form of particles
because we've only explored a small
fraction of parameter space so there's
this search you're
literally upon unintended are searching
in the dark here in this giant parameter
space of possible particles you're
searching for I mean there could be all
kinds of
particles could be and there's some
which may be very very hard to detect
but I think we can hope for um some new
theoretical ideas because um one point
which perhaps you'd like to discuss more
is about the very early stage of the Big
Bang um and uh the situation now is that
we have a outlined picture for How the
Universe has evolved um from the time
when was expanding in just a
nanc well up to the present and we could
do that because after
nanc the physics of the material is in
the same range that we can test in the
lab after a nanc the particle is moving
around like those in the L hat collider
if you wait for for one second they're
rather like in the centers of the
hottest stars and nuclear reactions
produce hydrogen helium Etc which fit
today so so we can with confidence
extrapolate back to when the universe
was a n second old inde I think we can
do it with as much confidence as
anything a geologist tells you about the
early history of the earth and that's
huge progress in the last 50 years but
any progress puts in sharper Focus uh
new Mysteries and of course the new
mystes in this context are why is the
universe expand the way it is why does
it contain this mixture of atoms and
dark matter and radiation and why does
it have the properties which allow
Galaxy to form being fairly smooth but
not completely smooth and the answer to
those questions are generally believed
to lie in a much much earlier stage of
the universe when conditions were much
more extreme and therefore far beyond
the stage when we had the foot told in
experiments very theoretical and so um
we don't have a convincing Theory we
just have ideas until we have something
like string theory or some other Clues
to the ultra early Universe uh that's
going to remain speculative so um
there's a big gap and to say how big the
Gap is um if we take the observable
universe out to bit more than 10 billion
life years um then when the universe was
a nanc old that would have been squeezed
down to the size of of our solar system
or compressed into that that volume but
the times we're talking about when the
Key properties of the universe were
first imprinted were times when that
entire universe was squeezed down to the
size of a tennis ball or baseball if you
prefer and to emerge from something
microscopic so it's a huge extrapolation
and it's not surprising that since it's
so far from our experimental range of
detectability uh we are still groping
for
ideas but you think first Theory will
reach into that place and then
experiment will perhaps one day catch up
well I think simulation in a sense it's
combination I think what what we hope
for is that um uh there'll be a theory
which applies to the early universe but
which also has consequences which we can
test in our present day Universe um like
um discovering why neutros exist or
things like that and that's the thing
which as I mentioned we may perhaps need
a bit of AI to help us to calculate but
but I think um the the hope would be
that we will have a theory which applies
under the very very extreme early stages
of the universe but which gains
credibility and gains confidence because
it also manages to account for otherwise
unexplained features of um the low
energy world and what people call a
standard model of particle physics where
there lots of undetermined numbers so it
may help with that so we're dancing
between physics and philosophy a little
bit but what do you
think what do you think happened before
the Big Bang so this seems this feels
like something that's out of the reach
of science it's out of the reach of
present science because science develops
and as the front is Advance uh then new
problems come into Focus that couldn't
even been postulated before I mean if I
think of my own career when I was a
student the evidence for the Big Bang
was pretty weak whereas now it's
extremely strong um but we are now
thinking about the reason why the
universe is the way it is and all that
um so uh I I would put all these things
we've just mentioned in the category of
speculative science um and I don't see a
bicationic um but of course to answer
your question
if we do want to understand the very
early Universe then we've got to realize
that it may involve even more
counterintuitive Concepts than quantum
theory does because it's a condition
even further away from everyday world
than quantum theory is and remember our
lives our brains evolved um and haven't
changed much since an Our Ancestors roam
the African Savannah and looked at the
everyday World um and uh it's rather
amazing that we've been able to make
some sense of the quantum microw world
and of the cosmos but uh uh there may be
some things which are Beyond us and
certainly as you implied there are
things that we don't yet understand at
all and of course one concept we might
have to jettison is the idea of three
dimensions of space and time just
ticking away there lots of ideas I mean
I think stepen Hawking had an idea that
talking about what's what hasn't before
the big bang it's like asking what
happens if you go north from the North
Pole you know it somehow closes off
that's just one idea um I don't like
that idea but that's a possible one um
and uh and so we just don't know um
what's happened at the very beginning of
the Big Bang were there many Big Bangs
rather than one Etc um and those are
issues which um we may be able to get
some foothold on from some new Theory um
but even then um we won't be able to
directly test the theories but I think
um it's a heresy to think you have to be
able to test every prediction of a
theory let me give another example um we
take seriously what Einstein's theory
says about the inside of black holes
even though we can't observe them
because that theory has been Vindicated
in many other places in cosmology and
black holes gravitational waves and all
those things um likewise if we had a a
theory which um explains some things
about the early history of our big bang
in the present Universe then we would
take
seriously the inference if it predicted
many Big Bangs not one even though we
can't predict the other ones so the
example is that we can take seriously a
prediction if it's the consequence of a
theory that we believe on other grounds
we don't need to be able to uh detect
another big bang in order to take it
seriously it may not be a proof but it's
a good indication that uh this is the
direction where the truth lies yeah if
the theory is gained confidence in other
ways yes what do you sense do you think
there's other universes besides our
own those are sort of well- defined
theories which make assumptions about
the physics at the relevant time and
this time incidentally is 10 the^ 36
seconds um or earlier than that so this
tiny sliver of time and um the some
theories uh famous One du to Andre
lindai um the Russian cosmologist now at
Stanford called Eternal inflation um
which did predict um an eternal
production of new Big Bangs as it were
and uh that's based on specific
assumptions about the physics but those
assumptions of course are just
hypotheses which aren't Vindicated
but there are other theories which only
predict one big bang so I think uh we
should be open-minded and not dogmatic
about these these options until we do
understand the relevant physics but
there are these different scenarios of
very different ideas about about this
but I think all of them have the feature
that physical reality is a lot more
extensive than what we can see through
our telescope I think even the most
conservative astronomers would say that
because
we can see out with our telescopes to a
sort of horizon which is
about depending on how you measure it
maybe 15 billion light years away or
something like that but that Horizon of
our observations is no more physical
reality than the Horizon around you if
you're in the
ocean and look looking out at your
horizon there's no reason to think that
the ocean ends just beyond your Horizon
and likewise there's no reason to think
that the aftermath of our big bang um
ends just at the boundary of what we can
see indeed they're quite strong
arguments um that it probably goes on
about 100 times further it may even go
on so much further that uh all
combinatorial are replicated and uh
there's another set of people like us
sitting in in a room like this every
possible combination of yeah that that
could
happen that's not logically impossible
um but but I think I think many people
would accept that it does go on um and
contain um probably a million times as
much stuff as what we can see within the
Horizon the reason for that incidentally
is that if we look as far as we can in
One Direction and in the opposite
direction then the conditions don't
differ by more than one pass in 100
thousand so that means that if we're
part of some finite structure the
gradient across the part we can see is
very small and so that suggests that it
probably does go on a lot further and
the best estimates say it must go at
least 20 times
further is that exciting or terrifying
to you just the spans of it all the wide
everything that lies Beyond the
Horizon that that example doesn't even
hold for Earth so it goes way way
farther and on top of that just to take
your metaphor further with the on the
ocean yeah while we're on top of this
ocean not only can we not see beyond on
the horizon we also don't know much
about the depth of the ocean that's
right nor the actual mechanism of
observation that's in our head yes no I
think the r and is all those points you
make yes yes but but I think um uh even
even the solar system is pretty vast by
human standards and so uh I don't think
the perception of this utterly vast
Cosmos um need have any
deeper impact on us than just realizing
that we are very small on the scale of
the external
world yeah it's humbling though it's
it's humbling in uh depending where your
ego is it's humbling in well if you
start very unhumble indeed it may make a
difference but for most of us I don't
think it make much much difference and
uh well there's a more general question
of course about uh um whether um the
human race as such is something which is
very special or if on the other hand um
it's just one of many
such species elsewhere in the universe
or indeed existing at different times in
our
universe it to me it feels uh almost
obvious that the Universe should be full
of alien life perhaps dead alien
civilizations but just the the vastness
of space
and yes it just feels wrong to think of
Earth as somehow special it sure as heck
doesn't look that special when you the
more we learn the less special it seems
well I mean I don't agree with that as
far as life is concerned because uh
remember that we don't understand how
life began here on Earth yes we don't
understand although we know that in
evolution from simple life to complex
life we don't understand uh what caused
the transition
between complex chemistry and the first
um replicating metabolizing entity we
call alive yes that's a mystery um and
uh serious physicists are now and
chemists are now thinking about it but
we we don't know so we therefore can't
say was it a rare fluke yeah which would
not have happened anywhere else or was
it something which uh involves a process
would have happened in any other planet
where conditions were like they were on
the young Earth um so we can't say that
now um I think well many of us would
indeed bet that probably some kind of
Life exists elsewhere but even if um you
accept that then um there many
contingencies going from simple life to
um uh present day life and and some
biologists like Stephen J Gould thought
that if you reran Evolution you'd end up
with something quite different and maybe
nothing with intelligent species so the
contingencies in evolution um May
militate against the emergence of
intelligence even if life gets started
in lots of places so I think these are
still completely open questions and
that's why it's such an exciting time
now that we are starting to be able to
address these I mean I mentioned the uh
the fact that the origin of life is a
question that we may be able to
understand um and serious people are
working on it it used to be put in the
sort of twoo difficult box everyone knew
was important but they didn't know how
to tackle it or what exp expon to do but
it's not like that now and um that's
partly because of clever experiments but
I think most importantly because um we
are aware that we can look for life in
other places other places in our solar
system and of course on the exoplanets
around other stars and uh within 10 or
20 years I think two things could happen
which would be really really important
we might with the next big T scope be
able to image some of the earthlike
planets around other stars image like
get a picture well actually let me
caveat that it take 50 years to get a
resolved image but but but but actually
detect the light because now of course
these exoplant are detected by their
effect on the parent star they either
cause their parent star to dim slightly
when they Transit across in front of it
and so we see the dips or their
gravitational the pole makes the star
wobble a bit so so most of the the 5,000
plus planets that have been found around
other stars they've been found
indirectly by their effect yes in one of
those two ways on the par you can still
do a pretty good job of estimating size
all those kinds of things size and the
size and the mass you can estimate um
but uh um but detecting the the actual
light from one of these EXO planets
hasn't really been done yet except one
of two very very very bright big planet
so maybe like James Webb Telescope would
be well James web may do this but even
better will be the European groundbased
telescope called unimaginative the
extremely large telescope which has a 39
M diameter mirror 39 M mic of 800 sheet
of glass and that will collect enough
light from one of these exoplanets
around a nearby star um to be able to um
separate out its light from that of the
star which is a millions of times
brighter and get the spectrum of the
planet and see if it's got oxygen or
chlorophyll and things in it so that
that that will come um J James web may
may make some some steps there um but I
think we can look forward to learning
quite a bit um in the next 20 years
because I like to say um supposing that
aliens looking at the solar system then
they'd see the Sun as an ordinary star
they'd see the Earth as in Carl sega's
eyes phrase a pale blue dot lying very
close in the sky to its star our sun and
much much much fainter but if they could
observe that dot they could learn quite
a bit they could perhaps get the spect
of the light and find the atmosphere
they'd find the shade of blue is
slightly different depending on whether
the Pacific Ocean or the land mass of
Asia was facing them so they could infer
the length of the day and the oceans and
continents and maybe something about the
seasons and the climate and uh that's
the kind of calculation calculation and
inference we might be able to draw
within the next 10 or 20 years about
other exoplanets and um and evidence of
some sort of biosphere on one of them
would of course be crucial and it would
rule out the uh still logical
possibility that life is unique but
there's another way in which this may
happen in the next 20 years people think
there could be something swimming under
the ice of Europa and Enceladus and
probes are being sent to maybe not quite
go under the ice but detect the spray
coming coming out to see if there's
evidence for Organics in that and if we
found any evidence for an origin of life
that happened in either of those places
that would immediately be important
because if life has originated twice
independently in one planed system the
solar system that would tell us straight
away it wasn't a rare accident and must
have happened billions of times in the
Galaxy at the moment we can't rule out
it being unique and incidentally if we
found life on Mars then that would still
be ambiguous because uh um people have
realized that this early life could have
got from Mars to Earth or vice versa on
meteorites so um if you found life on
Mars then some Skeptics could still say
if it's a single origin um but I think
but europa's far that's far enough away
statistically so so that's why that
would be especially it's always the
Skeptics that ruin a good party but but
we need them of course we need them at
the party we need some Skeptics at the
party um but boy would that be so
exciting to find life on one of the
moons yeah because it
means that just be any kind of
vegetation or life um the question of
the um aliens of Science Fiction is a
different matter intelligent aliens yeah
but if if you have a good indication
that there's life elsewhere in the solar
system that means life is
everywhere Y and that y That's I don't
know if that's terrifying or what that
is because if life is everywhere why is
intelligent life not everywhere why I
mean you've talked about that most
likely alien civilizations if they are
out there they would likely be far ahead
of us the ones that would actually
communicate with us yes and
that um again one of those things that
is both exciting and terrifying you
you've mentioned that they're likely not
to be of biological nature well I think
that's important of course again it's a
speculation but uh uh in speculating
about um intelligent life and I I take
the search seriously in fact I chair the
uh committee that the um Russian
American investor Yuri Milner supports
looking for intelligent life he's
putting 10 million dollars a year into
better equipment and getting time on
telescopes to do this and so I think
it's worthwhile even though I I don't
hold my breath for Success it's it's
very exciting but but that does lead me
to wonder what might be detected and um
I think well we don't know we've got to
be open minded about anything we have no
idea what it will be and so any
anomalous object or even some strange
shiny object in the solar system or
anything we've got to keep our eyes open
for but I think um if we ask what about
a um Planet like the Earth where
Evolution had taken more of the same
track then as you say it wouldn't be
synchronized um if it had lagged behind
then of course it would not have got to
Advanced life uh but it may have had a
Stars it may have formed on a planet
around an older star okay but then let's
ask what we would see um it's taken
nearly four billion years from the first
life to us and we've now got this
technological
civilization which uh um could make
itself detectable um to any alien live
aliens out there um but I think most
people would say that this civilization
of Flesh and Blood creatures in the
collective civilization may not last
more than a few hundred years more I
think that the that people may some
people would say it it it will um kill
itself off um but I'm more optimistic
and I would say that um what we're going
to have in future is um no longer the
slow darwinian selection but we're going
to have what I call secular intell
design which will be um humans designing
um uh their progeny to be better adapted
to where they are and uh if they go to
Mars or some somewhere they're badly
adapted they want to adapt a lot and so
uh they will adapt um but there may be
some limits to what could be done with
flesh and blood and so they may become
largely electronic um download their
brains and have and be electronic
entities and if they're
electronic then what's important is that
they're near
Immortal and also they won't necessarily
want to be on a planet with an
atmosphere or gravity they may go off
into the blue yonder and they and if
they're near Immortal they won't be
daunted by Interstellar travel taking a
long time and so um uh if if we looked
at what would happen on the earth in the
next millions of years then there may be
these electronic entities which have
been sent out and are now far away from
the Earth but still sort of burping away
in some in some fashion to be detected
um and so uh this um this therefore
leads me to think that um if there was
another planet which had evolved like
the Earth and was ahead of us uh it
wouldn't be synchronized so we wouldn't
see a flesh and blood civilization but
we would see these electronic progeny as
it were um and and then this raes
another question because um there's the
famous argument against there being um
lots of aliens out there which is that
they would um come and invade us and eat
us or something like that you know
that's a common idea U so fairy is
attributed to have been the first to say
um and I think there's a um es scape
Clause to that because these um entities
yeah would be say they evolve by secular
andt design designed by their
predecessors and then designed by us um
and uh um whereas darwinian selection
requires two things it requires
aggression and
intelligence this future intelligence
design um May favor intelligence because
that's what they were designed for but
it may not favor aggression and so these
future entities they they may be um
sitting Deep Thoughts thinking Deep
Thoughts um and and not being a tall
expansionist so they could be out there
yeah and we can't refute their existence
in the way the fair Paradox is supposed
to refute their existence because these
would not be aggressive or expansionist
well maybe Evolution requires
competition not aggression and I wonder
if competition can take forms that are
non- expansionary so you can still have
fun competing yeah in the space of ideas
which maybe primarily the philosophers
perhaps
yeah in in a way right it's a it's an
intellectual exercise versus a sort of
violent exercise so what does this
civilization on Mars look like so do you
think we would more and more you know
maybe start with some genetic
modification and then move to basically
cyborgs increasing integration of
electronic systems computational systems
into our bodies and brains this is a
theme of um uh my other new book out
this year which is called the end of
astronauts and end of asona co-written
with my um uh old friend and colleague
from Berkeley Don Goldsmith and uh it's
really about um the the role of human
space flight versus sort of robotic
space flight and um just to summarize
what it says um it argues that the um
practical case for sending humans into
space is getting getting weaker all the
time as robots get better more capable
robots 50 years ago couldn't do anything
very much but now they could assemble
big structures on space or on in space
or on the moon and they could probably
do exploration well present ones uh on
Mars um can't actually um do the geology
but future AI will be able to do the
geology and already they can dig on Mars
and so if you want to do exploration of
Mars and of course even more of um encel
or Europa where you could never send
humans we depend on
robots and they're far far cheaper
because to send a human to Mars requires
feeding them for 200 days on the journey
there and bringing them back and neither
of those are necessary for robots so the
Practical case for humans is getting
very very weak and if humans go it's
only as an adventure really and so the
line in our book is that um
uh human space flight should not be
pursued by nasau or Public Funding
agencies um because it has no practical
purpose but also because it's specially
expensive if they do it because they
would have to be risk averse in
launching civilians into
space I can illustrate that by noting
that the shuttle
was launched 135 times and it had two
spectacular failures which each kill the
seven people in the crew um and uh it
had been mistakenly presented as safe
for civilians and there was a woman
school teacher killed in one of them it
was a big National trauma and they tried
to make it safer still um
but if you launch into space just the
kind of people prepared to accept that
sort of risk and of course test p and
people who go hangliding and go to the
South Pole Etc are prepared to accept a
2% risk at least for a big challenge
then of course you do it more cheaply
and that's why um uh I think um human
space f should be left to the
billionaires um and their sponsors um
because then the taxpayers aren't paying
and they can launch simply those people
who are prepared to accept
risks space adventure not space tourism
yeah and and we should cheer them on um
and um as regards where they would
go then um lowth orbit I suspect can be
done quite cheaply in future but going
to Mars which is very very expensive and
dangerous for humans um the only people
who would go would be um these um
adventurers um
maybe on one way trip like some of the
early polish explorers and mellan and
people like that you know and we would
share them on um and I expect and I very
much hope that by the end of a century
there will be a small community of such
people on
Mars um living very uncomfortably far
less comfortably than at the South Pole
or the bottom of the ocean or top of
Everest but they will be there uh um and
they won't have certain ticket um but
they they'll be there um
incidentally I think it's a dangerous
delusion to think as uh Elon Musk has
said that we can have mass
immigration from the Earth to Mars to
escape the Earth's problems um it's a
dangerous illusion because it's far
easier to deal with climate change on
Earth than to terraform Mars to make it
properly habitable to humans so there's
no Planet be for a risk averse people
but for these crazy adventurers uh then
you could imagine that they would be
trying to live on Mars as um as great
pioneers and by the end of the century
then there will be huge advances
compared to the present in two things
first in in the understanding genetics
so as to genetically redesign one's
Offspring and secondly to use cybor
techniques to um implant some something
in our brain or indeed think about
downloading Etc and those techniques
will will one hopes be heavily regulated
on Earth on
credentials and ethical grounds and of
course we are pretty well adapted to the
Earth so we don't have the incentive to
do these things in the way they were
there so um our argument is that um
it'll be those crazy Pioneers on Mars
using all these scientific advances
which will be controlled here away from
The Regulators they will transition into
a new posthuman species MH and so um if
they do that and if they transition into
something which is electronic eventually
because there may be some limits to the
capacity of Flesh and Blood brains
anyways um then um those electronic
entities um may not want to stay on a
planet like Mars they may want to go go
away and so they'll be the precursors of
the future um evolution of life and
Intelligence coming from the earth um
and of course there's one point which
perhaps astronomers are more aware of
than most people most people are aware
that we are the outcome of four billion
years of
evolution most of them nonetheless
probably think that we humans are
somehow the
culmination the top of the
tree but yes no astronomers can believe
that because astronomers know that the
Earth is 4 and a half billion years
old the sun's been shining for length of
time but the sun has got six billion
years more to go before it flares up and
engulfs the inner planet so the sun is
less than halfway through his life um
and the expanding Universe goes on far
longer still maybe forever and I quote
Woody Allen who said eternity is very
long especially towards the end so uh so
we shouldn't think of ourselves as maybe
even a halfway stage in the emergence of
cosmic complexity and so these entities
who are
post cursors they will go beyond the
solar system and of course even if
there's nothing else out there already
then they could uh populate the the rest
of the the Galaxy and maybe eventually
meet the others who are out there
expanding as well yeah expanding and
populating with
expanded uh capacity for life and
intelligence all those kinds of things
well they might um but um uh again all
better off because can't see what they'd
be like um they won't they won't be uh
um green green men and women with eyes
on stalks you know they' be something
quite different um we we just don't know
um but there is an interesting question
actually which comes up when I've
sometimes spoken to audiences about this
topic but the question of Consciousness
and self-awareness because you going
back to philosophical questions I mean
it's whether an electronic
robot would uh be a zombie or would it
be conscious and self aware and um um I
think there's no way of answering this
empirically um and um some people think
that Consciousness and self-awareness is
an emerging property in any sufficiently
complicated Network that they would be
others say well maybe it's something
special to the flesh and blood that
we're made of we don't know um and in a
sense this may not matter um to the way
people things behave because we they
could be zombies and still behave as
though they were intelligent but uh I
remember after one of my talks someone
came up and said wouldn't it be
sad if these future entities which were
the main intelligence in the universe um
had no self-awareness so there was
nothing which could appreciate the
Wonder and mystery of the universe and
the beauty of the universe in the way
that we do um and so it does perhaps
affect one's perspective of whether you
welcome or deploy for this possible
future scenario depending whether you
think the the future posthuman entities
are conscious and have an aesthetic
sense or whether they're just zombies
and uh of course you have to be humble
to realize that self-awareness may not
be the highest form of
being that humans have a very strong ego
and a very strong sense of identity like
personal identity connected to this
particular brain yeah yeah uh it's not
so obvious to me that that is somehow
the the highest
achievement of a life form that maybe
this kind of you think something
Collective would be it's possible that
uh well I think from an alien
perspective when you look at Earth it's
not so obvious to me that individual
humans are the atoms of intelligence it
could be the entire organism together
the collective intelligence and so we
humans think of ourselves as individuals
we dress up we Wear Ties and suits and
we give each other prizes but in
reality the intelligence the things we
create that are beautiful emerges from
our interaction with each other and that
may be where the intelligence is ideas
jumping from one person to another over
Generations yes but we have experiences
where we uh can appreciate yes Beauty
and wonder and all that and uh uh a
zombie may not have those
experiences yeah or it may have a very
different we have a very black and white
harsh description of Z like a
philosophical zombie zombie that could
be just a very different way to
experience
uh and you know in terms of the
explorers that colonized
Mars I um I mean there there's several
things I want to mention one
it's just at a high level to me that's
one of the most inspiring things humans
can do is reach out into the unknown
that's in the space of ideas in the
space of science but also the Explorers
yes no I agree with that and and that
inspires people here on Earth more uh I
mean it did in the