Kind: captions
Language: en
the following is a conversation with avi
loeb an astrophysicist
astronomer and cosmologist at harvard he
has authored
over 800 papers and written eight books
including his latest called
extraterrestrial
the first sign of intelligent life
beyond earth it'll be released in a
couple of weeks
so go pre-order it now to show support
for what i think is truly an important
book
in that it serves as a strong example of
a scientist being both
rigorous and open-minded about the
question
of intelligent alien civilizations in
our universe
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as a side note let me say a bit more
about why avi's work is
so exciting to me and i think to a lot
of people
in 2017 a strange interstellar object
now named amuamoa it's fun to say
was detected traveling through our solar
system based on the evidence we have it
has strange characteristics which made
it not like any asteroid or comet
that we've seen before avi was one of
the only world-class scientists who
fearlessly suggested
that we should be open-minded about
whether it is naturally made
or in fact is an artifact of an
intelligent alien civilization
in fact he suggested that the more
likely explanation
given the evidence is the latter
hypothesis but we also talk about
a lot of fascinating mysteries in our
universe including black holes
dark matter the big bang and close the
speed
of light space travel the theme
throughout is that
in scientific pursuits the weird things
the anomalies
the ideas that right now are considered
taboo should not be ignored
if we're to have a chance at finding the
next big breakthrough
the next big paradigm shift and also
if we are to inspire the world with the
power and beauty of science
if you enjoy this thing subscribe on
youtube review on apple podcast
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connect with me on twitter
and lex friedman and now here's my
conversation
with avi loeb in the introduction to
your new book
extraterrestrial you write this book
confronts one of the universe's most
profound
questions are we alone
over time this question has been framed
in different ways
is life here on earth the only life in
the universe are humans the only
sentient intelligence in the vastness of
space and time
a better more precise framing of this
question would be this
throughout the expanse of space and over
the lifetime of the universe
are there now or have ever been other
sentient civilizations
that like ours explored the stars
and left evidence of their efforts so
let me ask
are we alone that's an excellent
question uh for me
the answer is sort of clear because
i start from the principle of modesty
you know if we believe that we are alone
and special and unique
that shows organs my daughters when they
were infants they tended to think that
they are special
unique and then they went out to the
street
and realized that other kids are very
much like them and
and then they developed a sense of a
better perspective about
themselves and i think the only reason
that we are still thinking that we are
special
is because we haven't searched well
enough to find others
that might even be better than us and
you know i say that because i look at
the newspaper every morning and i see
that we
do foolish things we are not necessarily
the most intelligent ones
and if you think about it if you open a
recipe book
you see that out of the same ingredients
you can make very different cakes
depending on how you put them together
and how you heat them up
and what is the chance that by taking
the
soup of chemicals that existed on earth
and cooking it one way to get
our life that you got the best cake
possible
i mean we are probably not the sharpest
cookie in the jar
and the my question is i mean it's
pretty obvious to me that we're probably
not alone because
half of all the sun-like stars we know
now as astronomers half of the sunlight
stars
from the kepler satellite data have a
planet
the size of the earth roughly at the
same distance that the earth is
from the sun and that means that they
can have liquid water on their surface
and the chemistry of life as we know it
so if you roll the dice
billions of times just within the milky
way galaxy
and then you have tens of billions of
galaxies like it
within the observable volume of the
universe it would be extremely arrogant
to think that we're special i would
think that we're
sort of middle of the road typical forms
of life and that's why
nobody pays attention to us you know if
you go down the street on a sidewalk
and you see an ant you don't pay
attention or a special respect to that
ant you just continue to walk and
so i think that we are sort of average
not very interesting not exciting so
nobody cares about us
we tend to think that we're special but
that's a sign of immaturity and we're
very early on in our development
yes that's another thing that we have
our technology only for 100 years
and it's evolving exponentially right
now on a three-year time scale
so imagine what would happen in a
hundred years in a thousand years
in a million years or in a billion years
now the sun
is actually relatively late in the star
formation
history of the universe most of the
sun-like stars formed earlier
and some of them already died you know
became white dwarfs
and so if you imagine that
a civilization like ours existed around
a typical sun-like star
by now if they survived they could be a
billion years old
and then imagine a billionaire
technology it would look like magic to
us it
you know an approximation to god we
wouldn't be able to understand it
uh and so to in my view we should be
humble
and by the way we should probably just
listen and not speak
because there is a risk right if if
if you are inferior there is a risk if
you speak too loudly
uh something bad may happen to you you
mentioned uh
we should be humble also in the sense
with the analogy to ants
that uh they might be better than us
so there's a kind of scale that we're
talking about and in the
in the question you mentioned the word
sentient
so sentience or maybe the more basic
formulation of that is consciousness do
you think
um do you think that this thing within
us humans in terms of the
typical life form of consciousness
is the essential element that permeates
other if if there's other alien
civilizations out there that they have
something like consciousness as well
or is this i guess i'm asking can you
try to untangle the word sentient
yeah so that's that's a good question uh
i think what is most abundant depending
on how long it survives
so if you look at us as an example
we are now we do have conscious and we
do have technology
but the technologies that we are
developing are also
means for our own destruction yes we can
tell
you know we can change the climate if we
are not careful enough
we can go into nuclear wars so we are
developing
means for our own destruction through
self-inflicted wounds
and it might well be that creatures like
us
are not long-lived that the crocodiles
on other planets live for billions of
years
they don't destroy themselves they live
naturally and so if you look around
the most common thing would be dumb
animals that live for long times you
know not those that have conscious
but in terms of changing the environment
i think since i mean humans develop
tools they've developed the ability
to construct technologies that would
lift us from this planet that we were
born in and that's something
animals without a conscious
consciousness cannot really
do and and so i you know in terms of
uh looking for things that are new that
that went beyond the circumstances they
were born into
i would think that even if they are
short-lived these are
the creatures that made the biggest
difference to their environment
and we can search for them you know even
if they're short-lived
and most of the civilizations are dead
by now yeah
even if that's the case that's sad to
think about by the way well but if you
look on earth
that you know there's lots of cultures
that exist throughout time and they're
dead by now
the mayan culture was very sophisticated
died
but we can find evidence for it and
learn about it just by
archaeology digging into the ground
looking and so we can do the same thing
in space
look for dead civilizations and perhaps
we can learn a lesson
why they died and behave better so that
we will not share the same fate
so i think you know there is a lesson to
be learned from the sky
and by the way i should also say if we
find a technology that we have not
dreamed of that we can import to earth
that may be a better strategy for making
a fortune
than going to silicon valley or going to
wall street
because you learn you make a jump start
into something of the future so that's
one way to do the leap is actually to
find
to literally discover versus come up
with the idea
in our own limited human capacity like a
cognitive capacity it would look like it
would feel like cheating in an exam
where you look over the shoulder of a
student next to you
yeah but it's not good on an exam but it
is good
when you're coming up with technology
that could change the the fabric of
human civilization
but there is uh you know in my
neck of the woods of artificial
intelligence there's a lot of
trajectories one can imagine
of creating very powerful
beings uh the technology that's
essentially
you know you can call super intelligence
that could achieve
space exploration all those kinds of
things without consciousness
right without something that to us
humans looks like consciousness
and there you know there is a sad
feeling i have that consciousness too in
terms of us being humble
is a thing we humans take too seriously
that it's we think it's special just
because we have it but it could be a
thing that's actually holding us back in
some kind of way may well be
it will be uh i should say something
about ai
because i do think it offers a very
important
step into the future if you look at the
old testament the bible
there is this story about noah's ark
that you might
know about noah knew about
a great flood that is about to endanger
all life on earth so he decided to build
an ark
and the bible actually talks about
specifically what the the size of this
ark was what the dimensions were
turns out it was quite similar to um
that we will discuss in a few minutes
but at any event he built this ark
and he put animals on it so that they
were saved from the
great flood now you can think about
doing the same on earth
because there are risks for future
catastrophes you know we could have the
self-inflicted wounds that we were
talking about
like nuclear war changing the climate or
there could be
an asteroid impacting us just like the
dinosaurs died you know they
the dinosaurs didn't have science
astronomy they couldn't
have a warning system but there was this
big stone big rock that approached there
it must have been a beautiful sight yeah
just when it was approaching got very
big and then smashed them
okay and killed them so um you could
have a catastrophe like that
or in a billion years the sun will
basically boil off all the oceans
on earth and
currently all our eggs are in one basket
but we can spread them
it's sort of like the printing press if
you think about it
the revolution that gutenberg brought is
there were
very few copies of the bible at the time
and each of them was precious because it
was handwritten
but once the printing press produced
multiple copies
you know if something bad happened to
one of the copies it wasn't
a catastrophe you know it wasn't
disaster because you had many more
copies that
and so if we have copies of life
here on earth elsewhere then we avoid
the risk of it
being eliminated by a single point
breakdown catastrophe so the question is
can we build
nox spaceship that will carry life as we
know
now you might think we have to put
elephants and
whales and birds on a big spaceship but
that's not true
because all you need to know is the dna
making
the genetic making of these animals put
it on
a computer system that has ai
plus a 3d printer
so that this cubesat which is rather
small
can go with this information to another
planet and use the raw materials there
to produce synthetic life and that would
be a way of producing copies just like
the gutenberg
printing press yeah and it doesn't have
to be exact copies of the humans it
could just
contain some basic elements of life and
then
have enough life on board that it could
uh
reproduce the process of evolution on
another place
right so i mean that also makes you sad
of course because it
uh you confront the mortality of your
own little precious consciousness and
all your own memories and knowledge and
all that stuff right
but who cares i mean we don't know i
care about mine right and you care about
yours
no no i actually don't you know if you
look at the big if you're an astronomer
one thing that you learn from the
universe
is to be modest because you are not so
significant
i mean think about it all these emperors
and kings that conquered a piece of land
on
earth and were extremely proud you know
you see these images
of kings and emperors that you know
usually are alpha males
and they stand you know strong and
um they're very proud of themselves but
if you think about it
there are 10 to the power 20 planets
like the earth
in the observable volume of the universe
and
this view of conquering a piece of land
and even conquering all of earth
is just like an ant hugging a single
grain of sand
on the landscape of a huge beach that's
not very impressive
so you can't be arrogant if you see the
big picture
you have to be humble you know also we
we are short-lived you know we
within a hundred years that's it right
so what does it teach you first to be
humble modest
you never have significant powers
relative to the big scheme of things
and second you should appreciate every
day that you live
yes and and learn about the world humble
and still grateful yes exactly
well let's uh talk about the
probably the most interesting object
i've heard about
and also the most fun to pronounce
can you tell me the story of this object
and why it may be
an important event in human history and
is it possibly a piece of alien
technology
right so this is the first object that
was spotted
close to earth from outside the solar
system
and it was found in on october 19
2017 and at that time it was receding
away from us
and at first astronomers thought it must
be a piece of rock you know just like
all the asteroids and comets that we
have seen from within the solar system
and it just came from another star i
should say that the actual discovery of
this object was surprising to me because
a decade earlier
i wrote the first paper together with ed
turner and
mauro martin that tried to predict
whether the same telescope that was
serving the sky
pan stars from hawaii would find
anything from
interstellar space given what we know
about the solar system so if you assume
that other
planetary systems have similar abundance
of
rocks and you just calculate how many
should be ejected into interstellar
space
the conclusion is no it we shouldn't
find anything
with pan stars to me i apologize it's
probably revealing my
stupidity but it was surprising to me
that so few interstellar objects
from outside this whole system have ever
been detected or
not none has been you you do well
maybe talk about it that there has been
uh uh
one or two rocks since then well since
then there was one
uh called the borisov it was discovered
by
an amateur russian astronomer yeah uh
gennady borisov
and that one looked like a comet
yeah and just like a comet from within
the solar system but this is a really
important point
sorry to interrupt it you showed that
it's unlikely that a rock from another
solar system
would arrive to ours right and so the
actual detection of this one was
surprising by itself
to me yes and
but then so at first they thought maybe
it's a comet or an asteroid but then it
look it didn't look like anything we've
seen before
borisov did look like a comet so people
asked me afterwards and said
you know doesn't it convince you if
borisov
looks like a comet doesn't he convince
you that um is also natural
yeah and i said you know when i went on
the first date with my wife
uh she looked special to me yes and
since then i met many women
yes that didn't change my opinion of my
life so you know that's not an argument
anyway so why did why did the
muah look weird let me explain so first
of all
astronomers monitored the amount of
light sunlight that it reflects
and it was tumbling spinning every eight
hours
and as it was spinning the brightness
that we saw from that direction we
couldn't resolve it because it's tiny
it's
about 100 meters a few hundred feet size
of a football field
and we cannot from earth with existing
telescopes
we cannot resolve it the only way to
actually get a photograph of it
is to send the camera close to it
and that was not possible at the time
that umua was discovered because it was
already moving away from us faster than
any rocket we can send
it's sort of like a guest that appeared
for dinner
and then by the time we realized that
it's weird the guest is already out the
front door into the dark street
yeah what we would like to find is an
object like
it approaching us because then you can
send the camera irrespective of how fast
it moves
and if we were to find it in july 2017
that would have been possible because it
was approaching us at that time
actually i was visiting mount haleakala
in maui hawaii with my family for
vacation at that time in july 2017 but
nobody knew uh
at the observatory that the um
is very close that's sad to think about
that we had the opportunity at that time
yes to send up a camera but don't worry
i mean there will be more there will be
more because
you know i i operate by the copernican
principle which says we don't live at a
special place
and we don't live at a special time and
that means
you know if we surveyed the sky for a
few years
and we had sensitivity to this region
between us and the sun
and we found this object with pan stars
you know there should be many more that
we will find in the future
with surveys that might be even better
yes uh and actually in a
in three years time scale there would be
uh the so-called lsst that's a survey of
the vera rubin observatory
that would be much more sensitive and
could potentially find
an umumua-like object every month
okay so wow i'm just waiting for that
and the main reason for me to alert
everyone uh to the unusual properties of
umumua
is with the hope that next time around
when we see something
as unusual we would take a photograph or
we would get as much evidence as
possible
because science is based on evidence not
on prejudice
and we will get back to that theme so
anyway let me let me point out some of
the properties actually yeah
the elongated nature all right other
things so
the light curve the amount of light
sunlight that was reflected from it
was changing over eight hours by a
factor of ten
meaning that the area of this object
even though we can't resolve it
the area on the sky that reflects
sunlight
was bigger by a factor of 10
in some phases as it was tumbling around
than in other phases so
even if you take a piece of paper that
is razor thin
you know it's there is a very small
likelihood that it's exactly edge-on
uh and getting a factor of 10 change in
the area that you see on the sky
is huge it's much more than any it means
that the object has an unusual geometry
it's at least a factor of a few more
than any of the comets or asteroids that
we have seen before
you mentioned reflectivity so it's not
just the geometry but
the the properties of the surface of
that thing well uh
or no if you assume the reflectivity is
the same okay then it's just geometry if
you assume the reflectivity may change
yes then it could be a combination of
the area that you see and the
reflectivity because
different directions may reflect
differently but the point is that it's
very extreme
yes and it actually the best fit
to the light curve that we saw was of a
flat object
unlike all the cartoons that you have
seen
of a cigar shape a flat object at the 90
percent confidence gives a better model
for the way that the light varied and
it's
like flat meaning like a pancake like a
pancake exactly
uh and then so that's the you know the
very first
unusual property but to me it was not
unusual enough
to think that it might be artificial it
was not
significant enough then um there was no
commentary tale you know
no dust no gas around this object and
the spitzer space telescope
really searched very deeply for
carbon-based molecules
there was nothing so it's definitely not
a comet
the way people expected it to be can you
maybe briefly mention what
uh properties a comet that you're
referring to usually has
right so a comet is a rock that has some
water ice on the surface
so you can think of it as an icy rock
actually comets were discovered a long
time ago but
uh the first model uh
that was developed for them was by fred
the whipple
who was at harvard and i think the
legend goes that he got the idea from
walking through
harvard square and seeing uh during a
winter day
and seeing these icy rocks you know and
so a comet is icy
and this is uh it's just a rock
it's just a wrap yeah so when you have
ice on the surface
when the rock gets close to the sun the
sunlight warms it up
and the the ice sublimates it evaporates
because the one thing about ice water
ice
is it doesn't become liquid if you warm
it up in vacuum
you know without an external pressure
it just goes straight into gas and
that's what you see as the
tail of a comet the only way to get
liquid water
is to have an atmosphere like on earth
that has an external pressure
only then you get liquid and that's why
it's essential to have an
atmosphere to a planet in order to have
liquid water
and the chemistry of life so if you look
at mars
mars lost its atmosphere and therefore
no liquid water on the surface anymore i
mean there may have been early
and that's what the perseverance uh
survey
you know the perseverance mission we
will try to find out whether
it had liquid water whether there was
life perhaps
on it at the time but at some point it
lost its atmosphere
and then the liquid water was gone so
the only reason that we can live
on earth is because of the atmosphere
but a comet is in vacuum
pretty much and then when it gets warmed
up on the surface
the water becomes the water ice becomes
gas and then you see this cometary tail
behind it
in addition to water there is
that there are all kinds of carbon-based
molecules of dust that comes
off the surface and those are detectable
yeah it's easy to detect it's very
prominent you see these cometary tails
that look very prominent because they
reflect sunlight
and you can see them in fact it's
sometimes difficult to see the nucleus
of the comet
because it's surrounded and shrouded
with and in this
case there was no trace of anything
that's fast now
you might say okay it's not a com so
that's what the community said okay it's
not a no problem it's still a rock you
know it's not a comet
but it's just a rock bare rock you know
okay no problem
then and that's the thing that convinced
me to write about it
and then in june 2018 you know
significantly later
there was a report that in fact the
object
exhibited an excess push
in addition to the force of gravity so
the sun acts on it by gravity but then
there was an
extra push on this object that was
figured out from the orbit
that you can trace and the the question
was what is this
excess push so for comets you get the
rocket effect when you evaporate gas
you know just like a jet engine on an
airplane
you throw a jet engine is very simple
you throw the gas back
and it pushes the airplane forward
that's all that's how it get
so in a case of a comet you throw gas in
the direction of the sun because it
and then you get a push okay so in the
case of comets you can get a push
but there was no commentary tale so then
people said oh wait a second
is it an asteroid no but it behaves like
a comet but
it doesn't look like a comet so what it
well forget about it business as usual
so that's what i mean by a
non-gravitational
acceleration so that's interesting so
like the
the primary force acting on something
like just a rock like an asteroid
would be like you can predict the
trajectory based on the
based on gravity and also here there's
detected movement that's
not cannot be accounted purely by the
gravity so if it was a comet
you would need about a tenth of
the mass of this comet the weight of
this government to be evaporated in
order
to give it and there's no sign of that
no sign ten percent of the mass
evaporating it's huge
think about it a hundred meter size
object losing ten percent of its mass
you can't miss that and uh so that's
super weird it's super weird what is
there a good explanation
in your mind and possible explanations
for this you know so i operated just
like sherlock holmes in a way
i said okay what are the possibilities
and the only thing i could think so i
ruled out
everything else and i i said it must be
the sunlight
reflected off it okay so the sunlight
reflects off the surface and gives it a
push
just like you get a push on a sail on a
boat you know from the wind reflecting
off it
now in order for this to be effective it
turns out the object needs to be
extremely thin
uh it turns out it needs to be less than
a millimeter thick
nature does not produce such things so
but
we produce it because it's called the
technology of a light sail
so we are for space exploration we are
exploring this technology because
it it has the benefit of not needing to
carry the fuel
with the spacecraft so you don't have
the fuel you just have a
uh you just have a sail and
it's being pushed either by sunlight or
by a laser beam
or whatever uh so perhaps this is the
light sail so this is
actually the same technology with the
with the starshop project yes
so yeah that's fascinating okay people
afterwards say okay you work on this
project you imagine
you know no that's a pretty good
explanation right obviously my
imagination is limited by what i know
so i you know i would not deny that you
know
working on light sales expanded my
ability to imagine this possibility yes
but let me offer another interesting
anecdote
in september this year 2020 i mean yes
uh
2020. yes um there was
another object found and it was given
the name
2020 so by the
minor planet center you know this is an
organization
actually in cambridge massachusetts that
gives names
to objects astronomical objects found in
the solar system and
they gave it that name 2020 so because
you know it looked like
uh an object in the solar system and
it moved in an orbit that is similar to
the orbit of the earth
but not the same exactly and therefore
it was bound
to the sun but it also exhibited
a deviation from what you expect based
on gravity
so the astronomers that found it
extrapolated back in time and found that
in 1966 it intercepted the earth
and then they realized they went to the
history books and they realized oh there
was a mission
called gruner surveyor lunar lander
surveyor 2 that had a rocket booster it
was a failed mission but
there was a rocket booster that was
kicked into space
and presumably this is the rocket
booster that we are seeing now
this rocket booster was sufficiently
hollow and thin
for us to recognize that it's pushed by
sunlight
so here is my point we can tell from the
orbit of an object obviously this object
didn't have any cometary tail
it was artificially made we know that it
was made by us
and it did deviate from an orbit of a
rock
so just by seeing something that doesn't
have cometary tail
and deviates from an orbit shaped by
gravity
we can tell that it's artificial in the
case of umuamua
it couldn't have been sent by humans
because it just
passed near us for a few months we know
exactly what we were doing in those
at that time and also it was moving
faster than any object that we can
launch
and so obviously it came from outside
the solar system
and the question is who produced it now
i should say that you know when i walk
on vacation on a beach i often see
natural
objects like seashells that are
beautiful and i look at them and
um and every now and then i stumble on a
plastic bottle
and that was artificially produced
and my point is that maybe omua mua was
a message in a bottle
and we should see this is simply another
window
into searching for artifacts from other
civilizations
where do you think it could have come
from and
if it's so okay from a scientific
perspective
the narrow-minded view as we'll probably
talk about throughout is you know you
kind of want to stick to the things that
uh to naturally originating objects like
asteroids and comets
okay that's the space of possible
hypotheses and then if we expand beyond
that
you start to think okay these are
artificially constructed like you just
said it could be by humans
it could be by uh by
whatever that means by some kind of
extraterrestrial alien
civilizations if if it's the alien
civilization
variety what is this object
then that will look at that an excellent
question and
let me lay out i mean we don't have
enough evidence to tell
if we had a photograph perhaps we would
have more information but
the possib there is one other peculiar
fact about umuamua
uh well other than it was very shiny i
that i didn't mention you know we didn't
detect any heat from it and
that implies that it's rather small and
shiny
uh but the other peculiar fact is that
it was it came from a very special frame
of reference
so it's sort of like finding a car in a
parking lot in a public parking lot
that you know you can't really tell
where it came from
so there is this frame of reference
where you average
over the motions of all the stars in the
neighborhood of the sun
so you find the so-called local standard
of rest
of the galaxy and that's uh
a frame of reference that is obtained by
averaging the random
motions of all the stars and the sun is
moving relative to that frame at some
speed
but this object was at rest in that
frame and only one in 500 stars
is so much at rest in that frame and
that's why i was saying it's like a
parking lot
it was parked there and we bumped into
it so the relative speed between the
solar system
and this object is just because we are
moving
it was sitting still now you ask
yourself why is it so
unusual in that context you know why
because if it was
expelled from another planetary system
most likely
it will carry the speed of the host star
that it came from because it was you
know the most loosely bound objects are
in the periphery
of the planetary system and they move
very slowly relative to the star and so
they carry
the when they are ripped apart from the
planetary system most of the objects
will have
the residual motion of the star roughly
relative to the local stuff
but this one was at rest in the locals
now one thing i can think of
if if there is a grid of uh
road posts you know like for navigation
system
so that you can find your way in the
local frame yeah
then that would be one position these
are like little sensors
of that's fascinating to think about so
there could be i mean not necessarily
literally a grid but just uh evenly
in some definition of evenly spread out
set of objects like these
right that are just out there a lot of
them another possibility is that
these are relay stations you know that
for communication
you might think in order to communicate
you need a huge beacon
yeah a very powerful beacon but it's not
true because even on earth you know we
have these relay stations so you have
a not so powerful beacon so it can be
heard only out to a limited distance but
then
you relay the message yes and it could
be one of those
now after it collided with this the
solar system of course it got a kick so
it's just like a
billiard ball you know we gave it a a
kick by colliding with
but most of them are not colliding with
stars and so that's one possibility
okay and there should be numer lots of
them if that's the case
um the other possibility
is that it's a probe you know that was
sent
uh in the direction of the um
habitable region around the sun to find
out if there is life
now it takes tens of thousands of years
for such a probe to traverse the solar
system from the outer edge of the oort
cloud
all the way to where we are and you know
it's a long journey so when it started
the journey from the edge of the solar
system to get to us now
you know we were rather primitive back
then you know we
we still didn't have any technology
there was no reason to visit you know
there was grass around and so forth
but you know maybe it is a problem uh
so you said ten thousand years as fast
so it takes that long tens of thousands
yes tens of thousands a year yeah yeah
and
uh the other thing i should say is you
know it could be just
a a an outer layer of something else
like
you know something that was ripped apart
like a surface of
an instrument that was and and you can
have lots of these pieces you know if
something breaks
lots of these pieces spread out like
space junk and
you know that it could be just space
junk
from an extra from an alien civilization
yes so it's i'm going to tell you about
space junk
let me yes what do you mean by space
junk so
um i think you know you might ask why
aren't they
looking for us one possibility is that
we are not interesting like we were
talking about
another possibility you know if there
are
millions of or billions of years uh
into their technological development
they created their own
their own habitat their own cocoon
where they feel comfortable they have
everything they need
and it it's risky for them to establish
communication with
other so they have their own cocoon and
they close off
they don't care about anything else now
in that case you might say oh
so how can we find about them if they
are closed off
the answer is they still have to deposit
trash
right that's that is something from the
law of thermodynamics
there must be some production of trash
and
you know we can still find about them
just like investigative journalists
going through the trash cans of
celebrities in hollywood you know
you can learn about the private lives of
those celebrities
by looking at the front it's fascinating
to think you know if
if we are the ants in this picture if we
if this thing is a water bottle
or if it's like a smartphone like where
where on the spectrum of possible
objects
of space because there's a lot of
interesting trash
like how interesting is this trash but
imagine a caveman
seeing a cellphone the caveman would
think since the caveman
played with rocks all of his life he
would say it's a rock
just like my fellow astronomers said yes
right exactly
that's brilliantly put actually as a
scientist do you hope it's a water
bottle or a smartphone because a smart
i hope it's even more than a smartphone
i hope that it's something that is
really sophisticated and funny
yeah see i'm the opposite i i feel like
i hope it's a water bottle
because at least we have a hope with our
current
set of skills to understand it yeah
caveman has no way of understanding the
smartphone it's like it will be
like i feel like a caveman has more to
learn from the plastic water bottle than
they do from the smartphone but suppose
we figure it out
if we if we for example come close to it
and and learn
what it's made of and i guess the
smartphone is full of like thousands of
different technologies that we could
probably pick at do you have a sense of
where
a hypothesis of where
is the cocoon that it might have come
from
no because uh okay so first of
all you know the solar system the
outermost edge of the solar system is
called the oort cloud
it's a cloud of icy rocks
um of different sizes
that were left over from the formation
of the solar system
yes and it it's thought to be roughly
a ball or a sphere and it's halfway the
extent of it is roughly halfway to the
nearest
star okay so you can imagine
each planetary system basically
touching uh the oort clouds of those
stars that are near us are touching each
other
space is full of these
billiard balls that are very densely
packed
yes and what that means is any object
that you see
irrespective whether it came from the
local standard so we said that this
object is special because it came from a
local standard of rest but even if it
didn't
you would never be able to trace where
it came from because
all these old clouds overlap so if you
take
some direction in the sky you will cross
as many stars as you have in that
direction like
there is no way to tell which old cloud
it came from so yes
i i didn't realize how densely packed
everything was uh yeah
from the perspective of the work cloud
and that's really interesting so
yeah it could be it could be nearby it
could be very far away yeah we have no
clue
you said cocoon that and you kind of uh
uh paint uh i think in the book i've
read a lot of your articles too on
scientific american which are brilliant
so i'm kind of mixing things up in my
head a little bit
but there's uh what does that
cocoon look like what is the
civilization that's able to harness
the power of multiple suns for example
um
look like they give when you imagine
possible civilizations that are
a million years more advanced than us
what do you think that actually like
looks like i think it's very different
than we can imagine
uh by the way i should start from the
point that
even biological life you know just
without technology
getting into the game uh could look like
something we have never seen before
take for example the nearest star which
is proxima centauri
it's four and a quarter light years away
so they will know
about the results of the 2016 elections
only next month in february 2021 yes
it's very far away um but
if you think about it um you know this
this
uh star is a is a dwarf star
and it's much cooler than it's uh
twice as cold as the sun okay and it
emits mostly infrared radiation
so if there are any creatures on
the planet close to it that is habitable
which is called proxima b
there is a planet in the habitable zone
in the zone just at the right distance
where
in principle liquid water can be on the
surface if there are any animals there
they have infrared eyes because our eyes
was
designed to be sensitive to where most
of the sunlight
is in the visible range but proxima
centaurium is mostly infrared so
you're not the nearest to see each other
in the nearest star system
these animals would be quite strange
they would have
eyes that are detectors of infrared very
different from ours
moreover this planet proxima b faces the
star
always with the same side so it has a
permanent dayside
and a permanent night side and obviously
the creatures that would
evolve on the permanent dayside which is
much warmer
would be quite different than those on
the permanent night side
between them there would be a permanent
sunset
strip and my daughters said that that's
the best
opportunity for high value real estate
because you will see the sunset
throughout your life right now the sun
never sets
on this on this trip so you know these
worlds are out of
our imagination just even the individual
creatures this
the sensor suite that they're operating
with might be very different very
different so i think when we
see something like that we would be
shocked not to speak about seeing
technology now
so i i don't even dare to imagine you
know
uh and i think you know obviously we can
bury our head
in the sand and say it's never aliens
like many of my colleagues say and it's
a self-fulfilling
prophecy if you if you never look you
will never find if you are not ready to
find
wonderful things you will never discover
them
and the other thing i would like to say
is reality
doesn't care whether you ignore it or
not you can ignore reality but it's
still there
yes so we can all agree based on twitter
that aliens don't exist that um
was a rock we can all agree and you will
get a lot of likes
they will have a big crowd of supporters
and everyone
will be happy and give each other awards
and honors and so forth
but um might still be an alien artifact
who cares what humans agree on yeah
there is a reality out there
and we have to be modest enough
to recognize that we should make our
statements based on
evidence science is not about ourself
it's not about glorifying our image it's
not about getting honors
prizes you know a lot of the scientific
a lot of the academic
activity is geared towards creating your
echo chamber where you have students
postdocs repeating your mantras
so that your voice is heard loudly so
that you can get more honors prizes
recognition
that's not the purpose of science the
purpose is to figure out what nature is
right and in the process of doing that
it's a learning experience
you make mistakes you know einstein made
three mistakes at the end of his career
he argued that in the 1930s he argued
that black holes don't exist
gravitational waves don't exist and
quantum mechanics doesn't have spooky
action at a distance
and all three turned out to be wrong
okay so
the point is that if you work at the
frontier of then you make mistakes it's
inevitable because you can't tell what
is true or not
and avoiding making mistakes in order to
preserve your image
makes you extremely boring okay you will
get a prize but you will be a
boring scientist because you will keep
repeating things we already know
if you want to make progress if you want
to innovate you have to take risks
and you have to look at the evidence
it's a dialogue with nature
you don't know the the truth in advance
you let nature tell you educate you
and then you you realize that what you
thought before
is incorrect and a lot of my colleagues
prefer to be in a state where they have
a monologue you know if you look at
these people that work on string theory
yes
uh they have a monologue they know what
and in fact
their monologue is centered on
anti-deceiter space which we don't live
in now you know it's to me it's just
like the olympics you know
you you define a hundred meters and you
say whoever runs this hundred meters
is the best athlete the fastest you know
and uh
it's completely arbitrary you could have
decided it would be 50 meters or 20
meters
who cares you just measure the ability
of people this way
so you define antidecital space as a
space where you do your mathematical
gymnastics
and then you find who can do it the best
and you give jobs based on that you give
prizes best
but as we said before you know nature
doesn't care about
you know the prizes that you give to
each other
it cares you know it has its own reality
and
we should figure it out and it's not
about us the scientific activity is
about
figuring out nature and sometimes we may
be wrong our image will not
be preserved but it's that's the fun you
know
kids explore the world out of curiosity
and
i always want to maintain my childhood
curiosity and
i don't care about the labels that i
have in fact
having tenure is is exactly the
opportunity to
behave like a child because you can make
mistakes yeah and
i was asked by the harvard gazette you
know the the new
the pravda of harvard uh
what what is the one thing that you
would like
to change about the world yes and i said
i would like my colleagues to behave
more like kids
yeah that's the one thing i would like
them to do because
something bad happens to these kids when
they become tenured professors
they start to worry about their ego yeah
and about themselves
more than about the purpose of science
which is
you know curiosity driven figuring out
from evidence evidence is the key
so when an object shows anomalies like
what's the problem discussing you know
whether it's artificial or not
you know so there was i should tell you
there was a mainstream
paper in nature published saying it must
be natural
that's it it's unusual but it must be
natural
period and then at the same time that
those main some other mainstream
scientists
tried to explain the properties yes and
they came up with interpretations like
it's a dust bunny you know the kind that
you find in a household a collection of
dust particles
pushed by sunlight something we have
never seen before
or it's a hydrogen iceberg it actually
evaporates like a
comet but hydrogen is transparent you
don't see it
and that's why we don't see the
commentary again we have never seen
something like that
in both cases the objects would not
survive
the long journey we discussed it in a
paper that i wrote afterwards
but my point is those that try to
explain the unusual properties
went into great length at discussing
things that we have never seen before
okay so even when you think about a
natural origin
you have to come up with scenarios that
of things that were never seen before
and by the way they look less plausible
to me personally
but my point is if we discuss things
that were never seen before
right why not discuss why not
contemplate
an artificial origin what's the problem
why do people have
this pushback you know i worked on on
dark matter
and we don't know what most of the
matter in the universe is
it's called dark metal it's just an
acronym because we have no clue
we simply don't know so it could be all
kinds of particles and over the years
people suggested weakly interacting
massive particles axions
all kinds of particles and experiments
were made
they cost hundreds of millions of
dollars they put upper limits
constraints that ruled out many of the
possibilities that were proposed
as natural initially the mainstream
community regarded it as a mainstream
activity to search
the nature of the dark matter and they
nobody complained that it's speculative
to consider weakly interacting massive
particles
now i asked you why is it speculative to
consider
extraterrestrial technologies we have
a proof that it exists here on earth yes
we also know
that the conditions of of of earth are
reproduced
in billions of systems throughout the
milky way galaxy
so what's more conservative than to say
if you arrange for similar
conditions you get the same outcome how
can you imagine this to be specula it's
not speculative at all
and nevertheless it's regarded the
periphery and at the same time you have
physicists theoretical physics
working on extra dimensions super
symmetry
uh super string theory the multiverse
maybe we live in a simulation all of
these ideas that have no
grounding in reality some of which
sound to me like you know just like what
someone would say
uh science fiction basically because you
have no way to test it
uh you know through experiments and
experiments really are key it's not just
the nuance
you say okay forget about experiment and
some philosophers try to say
you know if there is a consensus what's
the problem the point is
it's key then that's what galileo it's
key to have feedback from reality
you know you can think that you have a
billion dollars or that you are more
rich than you know uh elon musk
that's fine you can feel very happy
about it
you can talk about it with your friends
and all of you will be happy and
think about what you can do with the
money then you go to an atm machine and
you make an experiment
you check how much money you have in in
your checking account
and if it turns out that you know you
you don't have much you can't
you can't materialize your dreams
okay so you realize you have a reality
check yes and my point is
without experiments giving you a reality
check without the atm machine showing
you whether your ideas are bankrupt or
not
without putting skin in the game and by
skinning the game i mean
don't just talk about theoretical ideas
make them testable
if you don't make them testable they're
worthless
they're just like theology that is not
testable
by the way theology has some tests let
me give you
that's interesting three examples yes um
it turns out that my book already
inspired a phd student at harvard in the
english department
to pursue a phd in that direction and
she invited me to the phd exam a couple
of months ago
and in the exam one of the examiners a
professor
asked her do you know why jordano bruno
was burnt at the stake and she said
no i think it's because he was an
obnoxious guy and
irritated a lot of people yes which is
true
but the professor said no it's because
giordano bruno said that other stars
are just like the sun and they could
have a planet like the earth
around them that could host life
and that was offensive to the church why
was it offensive
because there is the possibility that
this life sinned
okay and if that life sinned on planets
around other stars
it should have been saved by christ and
then you need
multiple copies of christ and that's
unacceptable
how can you have duplicates of christ
right and so they burned the guy
it was about that's okay i'm just like
loading this all in because that's kind
of brilliant
so he he was actually already into it's
not just about the stars it's
anticipating that there could be other
life forms yeah
like why if this star if there's other
stars
why would it be special why would our
star be special
he was making the right argument and he
would just follow that
all along to say like there should be
other earth like
places there should be other life and
then there's different copies of christ
yes so that was offensive so i said i
said to that um
i said to that professor i said great
you know i wanted to introduce some
scientific tone to the discussion
and i said this is great because now you
basically laid the foundation for an
experimental test of this theology
what is the test we now know that other
stars are like the sun
and we know they have planets like the
earth around them so suppose we find
life there
and we figure out that they sinned
then we ask them did you witness christ
and if they say no it means that this
this theology
is ruled out so there is an experimental
test so this is experimental test number
one
another experimental test you know
in the bible you know in the old
testament abraham
uh was heard the voice
the voice of god to sacrifice
his son right only son and
that's what the story says now suppose
abraham
my name by the way had a voice memo
up on his cell phone yes he could have
pressed this up
and recorded the voice of god and that
would have been experimental evidence
that god exists
right fortunately he didn't but
it's an experimental test right there is
a third example i should tell
and that is elie wiesel attributed this
story to martin buber
but it's not clear whether it's true or
not at any event the story goes that
martin buber you know he was a
philosopher and he said
you know the christians argue that jesus
you know the
the messiah arrived already
and will come back again in the future
the jews
argue the messiah never came
and will arrive in the future so he said
why argue both sides agree
that the messiah will arrive in the
future
when the messiah arrives we can ask
whether
he or she came before you know like
visited us and then figure it out and
one side
so again experimental test of a theology
yes so
even theology if it puts
a skin in the game you know if it makes
a prediction could be tested
right so why can't string theories test
themselves or why can't
you know even cosmic inflation that's
another model that
you know one of the inventors from mit
alan guth argues that it's not
falsifiable
my point is a theory that cannot be
falsified
is not helpful because it means that you
can't make progress you cannot improve
your understanding
of nature the only way for us to learn
about nature is by
making hypotheses that are testable
doing the experiments and learning
whether we are correct or not
so b and coupled that with a curiosity
and open-mindedness that allows us to
explore
all kinds of possible hypotheses but
always
the pursuit of those the the scientific
rigor around those hypotheses is
ultimately get evidence knowledge is
of of what nature is should be a
dialogue with nature yes
rather than a monologue beautifully put
can we talk a little bit about the drake
equation
another framework from which to have
this kind of discussion about
uh possible civilizations out there so
let me ask
within the context of the drake equation
or maybe bigger
how many alien civilizations do you
think are out there
well it's hard to tell because the drake
equation is again quantifying our
ignorance it's just
a set of factors the only one
that we know are actually two that we
know quite well is
the rate of star formation in the milky
way galaxy which we
measured by now and the
frequency of planets like the earth
around stars yes
and at the right distance to have life
but other than that there are lots of
implicit assumptions about all the other
factors that will enable us to detect a
signal
now i should say the drake equation has
a very limited
validity just for signals from
civilizations that are
transmitting at the time that you're
observing them however
we can do much better than that we can
look for
artifacts that they left behind even
even if they are dead
you can look for industrial pollution in
the atmosphere supply
why do i bring this up again to show you
the conservatism of the mainstream
in astronomy and by the way i shouldn't
you know i have leadership positions i
was chair of the astronomy department
for nine years the longest serving chair
at harvard
and i'm the chair of the board on
physics and astronomy
of the national academies you know it's
the primary
board uh and um you know i'm director of
two centers at harvard and so forth
so i i do represent the community
in in various ways but at the same time
you know i'm a little bit disappointed
by the conservatism that people have
and so let me give you an illustration
of that so the astronomy community
actually is going right now through the
process of defining its goals for the
next decade
and there are proposals for telescopes
that would cost
billions of dollars and whose goal is to
find
evidence for oxygen in the atmosphere of
planets around other stars
with the idea that this would be a
marker a signature
of life now the problem with that is
earth didn't have much oxygen in its
atmosphere for the first two billion
years
roughly half you know half of its life
it didn't have much
oxygen but it had life it had microbial
life
it's not an it's not clear yet as of yet
what the origin is for the rise in the
oxygen level after two
billion years about 2.4 billion years
ago
but we know that a planet can have life
without oxygen in the atmosphere because
earth did it
the second problem with this approach is
that you can have oxygen from natural
processes
you can break water molecules and make
oxygen right so even if you find it
it will never tell you that for sure
life
exists there and so even with these
billions of dollars the mainstream
community
will never be confident but uh
whether there is life there now how can
it be confident there is actually a way
if instead of looking with the same
instruments if you look for molecules
that indicate
industrial pollution for example cfcs
you know that are produced by
refrigerating systems or industries here
on earth
that they do the ozone layer you know
you can search for that and i wrote a
paper five years ago
suggesting that now what's the problem
you can just tell nasa
i want to build this telescope to search
for oxygen but also for industrial
pollution nobody would say that
because it sounds like
you know on the periphery of the field
and
i asked you why hilarious because that's
exactly
i mean that's what you're saying is
quite brilliant i mean uh
because it's a really strong signal and
if
life if there's alien civilizations out
there then they're probably going to be
many of them and they're probably going
to be more advanced than us
and they're probably going to have
something like industrial pollution
which would be a much stronger signal
than
some basic gas which could have a lot of
different explanations
so like somebody like oxygen or i mean i
don't
you know uh i mean we could talk about
signs of life on venus and so on
but like if you want a strong signal it
would be
pollution i love how garbage is no but
the pollution you have to understand
we think of pollution as a problem but
on a planet that was too cold for
example
to have a comfortable life on it you can
imagine
terraforming it and putting a blanket of
polluting gases
such that it will be warmer and that
would be a positive change
so if an industrial or
a technological civilization wants to
terraform
a planet that otherwise is too cold for
them they would do it
so what's the problem of defining it as
a search goal using the same
technologies the problem is that there
is a taboo
we are not supposed to discuss
extraterrestrial intelligence there is
no funding for this subject
not much very little and young people
because of the bullying on twitter you
know all the social media and
elsewhere young people with talent that
are curious about this
these questions do not enter this field
of study
and obviously if you step on the grass
it will never grow right so if you don't
give funding
obviously you know the mainstream
community says look nothing was
discovered so far
obviously nothing would be discovered if
talented
people go to other disciplines never you
never search for it
well enough you will never find anything
i mean look at
gravitational wave astrophysics it's a
completely new window into the universe
pioneered by ray weiss at mit
and at first it was ridiculed
and thanks to some administrators at the
national science foundation it received
funding despite the fact
that the mainstream of the astronomy
community was very resistant
yes to it and now it's considered a
frontier
so all these people that i remember as a
postdoc a young postdoc these people
that
bash this field said bad things about
people you know said nothing will come
out of it
now they say oh yeah of course you know
the nobel prize was given
to the you know to the ligo
collaboration
of course now they're they're supportive
of it
but my point is if if if
you suppress innovation early on there
are lots of missed opportunities
the discovery of exoplanets is one
example you know in 1952 there was an
astronomer called the
named otto struve and he wrote the paper
saying why don't we search for
jupiter like planets close to their host
star
because if they're close enough they
would move the star back and forth and
we can detect the signal
yes okay and so astronomers
on time allocation committees of
telescopes for 40 years
argued this is not possible because we
know why jupiter
resides so far from the sun you cannot
have jupiter so close because
there is this region where ice forms far
from the sun
and beyond that region is where
jupiter-like planets can form
there was a theory behind it which ended
up being wrong by now by today's
standards but yes
anyway they did not give time on
telescopes to search for
such systems until the first system was
discovered
four decades after otto struve's paper
and the nobel prize was awarded to that
just a couple of years ago yeah and you
ask yourself okay so
you know science still made progress
what's the problem
the problem is that this baby came out
barely you know and and there was a
delay of four decades
so the progress was delayed and i wonder
how many babies were not born
because of this resistance so there must
be ideas that are as good
as this one that were suppressed because
they were bullied because
uh people ridiculed them
that were actually good ideas and we
these are missed opportunities babies
that were never born
yes and you know i'm willing to push
this frontier of the search for
technologies or
technological signatures of other
civilizations because you know when i
was young i was in the military
in israel it's obligatory to serve and
there was this saying that you know one
of the soldiers sometimes
has to put his body on the barbed wire
so that others can go through and
i'm willing to suffer the pain so that
you know younger people
in the future will be able to speak
freely about the possibility that some
of the anomalies we find in the sky
yes are due to technological signatures
and it's quite
obvious this is why i like like folks in
the artificial intelligence space
elon musk and a few others speak about
this
and they look at the long arc they say
like what
you know this kind of you know you can
call it like first principles thinking
or you can call anything
really is like if we just zoom off from
our
current bickering and our current like
discussions in the what science is doing
and
look at the long arc of the trajectory
we're headed at
which questions are obviously
fundamental
to science and it should be asked and
which is the space of hypotheses we
should be exploring
and like exoplanets is a really good
example of one that was like
an obvious one i recently talked to
sarah seeger
and it was very taboo when she was
starting out to work on an exoplanet and
that was even in the 90s
yeah and uh like it's obvious
should not be a taboo subject and to me
i mean i'm probably ignorant but
to me exoplanets seems like it's
ridiculous that that would ever be a
taboo subject
right to not fund to not explore that's
very
but even for her it's now taboo to say
like what you know to to look for
industrial pollution
right right it's like i find that
ridiculous i'll tell you why
you take the next step it's ridiculous
for another reason yes not because
of just the scientific benefits that we
might have by exploring it
but because the public cares about these
questions
yes and the public funds science
so how dare the scientists yes shy away
from addressing these questions
if they have the technology to do it
it's like saying i don't want to look
through galileo's telescope
it's exactly the same you have the
technology to explore this question
to find evidence and you shy away from
it
you might ask why do people shy away
from it yes
and perhaps it's because of the fact
that there is science fiction i i'm not
a fan of science fiction
because it has an element to it that
violates the laws of physics in many of
the books and
and the films and i cannot enjoy the
these things when i see the laws of
physics violated but
who cares that the you know the fact
that there is science fiction i mean if
if you have the scientific methodology
to address the same subject
i don't care that other people uh you
know spoke nonsense about this subject
or said things that make no sense who
cares you do your scientific work
just like you explore the dark matter
you explore the possibility that umuamua
is an artifact you just look for
evidence
and try to deduce uh what what it means
and i have no problem with doing that to
me it sounds like any other scientific
question that we have
and given the public's interest we have
an obligation to do that
by the way science to me is not an
occupation of the elite
it doesn't allow me to feel superior to
other humans that are unable to
understand the math
to me it's a it's a way of life you know
if there is a problem in the faucet or
in the pipe
at home i try to figure out what the
problem is and
with a plumber we figure it out and you
know we look at the clues and
the same thing in science you know you
look at the evidence you try to figure
out what it means
it's it's common sense in a way and
it shouldn't be regarded as something
removed from the public
it should be a reflection of the
public's interest and
i think it's actually a crime to resist
the public
if the public says i care about this and
you say no no that's not sophisticated
enough for me i want to do intellectual
gymnastics on auntie the sitter space
to me that's a crime yes i'd uh 100
agree
so it's it's hilarious that the very
not hilarious it's sad that
people who are trained in the scientific
community
to have the tools to explore this world
to be children to be the most effective
at being children
uh are the ones that resist being
children the most
but there is a large number of people
that embrace the childlike
wonder about the world and may not
necessarily have the tools to do it
that's the more general public
and so you know i wonder if i could
ask you and talk to you a little bit
about you know
ufo sightings that there's people
you know quote-unquote believers you
know there's hundreds of thousands of
ufo sightings and
you know i've you know consumed
some of the things that people have said
about it and uh
one one thing i really like about it is
how excited they are by the possibility
uh by it's it's almost like this
childlike wonder about the world out
there
they're not it's not a fear it's an
excitement
do you think because we're talking about
uh
this extra possibly extraterrestrial
object
that visited that flew by earth do you
think it's possible
that out of those hundreds of thousands
of ufo sightings
one is an actual one
or some number is an actual sighting of
a non-human
some alien technology and that we're not
um we did not we're too close-minded
to uh to look and to see
i think to answer this question we need
better
evidence my starting point
as i said out of modesty is that we are
not particularly interesting
and therefore i would agree i would be
hard-pressed to imagine that someone
wants to really spy on us
uh so i would think you know as a
starting point that
we don't deserve attention and we
shouldn't expect
someone but who knows now the problem
that i have with ufo citing reports
is that you know 50 years ago there were
some reports of fuzzy images you know
sorcerer-like
things uh by now our
technologies are much better our cameras
are much more sensitive
these fuzzy images should have turned
into crisp
clear images of things that we are
confident about
and they haven't turned that way it's
always on the borderline of
believability
and because of that i believe that it
might be most likely
artifacts of our instruments or some
natural phenomena
that we are unable to understand now of
course the reason you should you need
you must
examine those if for example pilots
report about them or
uh the military finds evidence for them
is because it may pose a national
security threat if another country has
technologies
that we don't know about and they're
spying on us we need to know about it
and therefore we should examine
everything that looks unusual
but to associate it with an alien
life is a little too far for me
until we have evidence that stands up to
the level of scientific
credence you know that that we are a
hundred percent sure
that you know from multiple detectors
and you know
through a scientific process now again
if the scientific community shies away
from these reports
we will never have that it's like saying
i don't want to
take photographs of something because i
know what it is
then you will never know what it is but
i think if
if some scientist if grants let's put it
this way if funding will be given to
scientists
to follow on some of these reports and
use scientific instruments
that are capable of detecting those
sightings
with much better resolution with much
better information
that would be great because it will
clarify the matter you know these are
not
as you said you know hundreds of
thousands these are not
once-in-a-lifetime events
so it's possible to take scientific
instrumentation
and explore go to the ocean where the
you know someone reported that there are
frequent events that are unusual
and check it out yeah do a scientific
experiment what's the problem why not
why only do experiments deep into the
ocean and look at the
oceanography or do other things you know
we can do scientific investigation of
these
sightings and figure out what what they
mean
uh i'm very much in favor of that uh but
until we have the evidence
i would be doubtful as to what they
actually mean
yeah we have to be humble and uh and
acknowledge that we're not that
interesting
it's kind of you're making me realize
that because it's so taboo that the
people that have the equipment
uh meaning and when i was just talking
everybody has cameras now
but to have a large-scale like uh
sensor right network that collects
data regularly collects just like we
look at the weather we're collecting
information
and then we can then x that information
when there is reports
and like have it not be a taboo thing
where there's like millions or billions
of dollars funding this effort
that by the way inspires
millions of people this is exactly what
you're talking about it's like
it's uh the scientific community is
afraid of a topic that inspires millions
of people exactly it's absurd
but if you put blinders on your eyes you
don't see it yeah
right i should say that we do have
meteors that we see
these are rocks that by chance happen to
collide with the earth
and they if they're small they burn up
in the atmosphere but
if they're big enough uh tens of meters
or more
hundreds of meters the outer layer burns
up but then the core of the
object makes it through and this is our
chance
of putting our hands around an object
if this meteor came from interstellar
space so
one path of discovery is to search for
interstellar meteors and with the
student of mine we actually looked
through the record and
we thought that we found one example of
a meteor that was reported
that might have come from interstellar
space
and another approach is for example to
look at the moon
the moon is different from the earth in
the sense that it doesn't have an
atmosphere
so objects do not burn up on their way
to it it's sort of like a museum it
collects everything that kind of rocks
from out there
deep space yeah and there is no
geological activity on the moon
so on earth every 100 million years you
know we could have had
computer terminals on earth that could
have been a civilization like ours
with electronic equipment yes more than
100 million years ago
and it's completely lost you cannot
excavate and find the
evidence for it because in
archaeological digs because the earth
is being mixed on these time scales and
everything that was on the surface more
than 100 million years ago
is buried deep inside the earth right
now because of geological activity
fascinating you think about by the way
yeah
but on the moon this doesn't happen the
only thing that happens on the moon is
you have objects impacting the moon and
they go
10 meters deep so they produce some dust
but
the moon keeps everything it's like a
museum it keeps everything on the
surface
so if we go to the moon i would highly
recommend regarding it as an
archaeological
site yes and looking for objects that
are strange
maybe it collected some trash you know
from interstellar space
if we could just linger on the on the
drake equation for a little bit
we kind of talked about there's a lot of
uncertainty in the parameters
and and our and in the drake equation
itself is very limited
but i think the parameters are
interesting in themselves
even if it's limited because i think
each one is within the reach of science
right right did you get the evidence for
uh i mean
one a few i find really interesting
could be
interesting to get your comment on uh so
the one with the most
variance i i would say from my
perspective is the
length that civilizations last however
you define it and the drake equation is
the length of how long you're
communicating yeah just like
transmitting just like you said that
that might that's a
wrong way to think about it because we
can be detecting some other outputs of
the civilizations etc
but just if we just define broadly how
long those civilizations last
do you have a sense of uh how long
that might last like what what are the
great filters that might destroy
civilizations that we should be thinking
about what uh
yeah is in and what it how can science
give us more hints
on this topic so i as i mentioned before
operate by the copernican principle
meaning that
you know we are not special we don't
live in a special place
and not in a special time and by the way
it's just modesty encapsulated in
scientific terms
yes right you're saying i'm not special
you know i find conditions here
they exist everywhere so if you adapt
the copernican principle
you basically say our civilization
transmitted radio signals for
100 years roughly so
probably it would last another hundred
or few hundred and that's it
because we don't live at a special time
so that's
you know well of course if we get our
act together
and we somehow start to cooperate rather
than fighting each other
killing each other you know wasting a
lot of resources
on things that would destroy our planet
maybe we can lengthen that period if we
get smarter
but the the most natural assumption is
to say
that we would live into the future as
much as we lived
from the time that we start to develop
the means for our own destruction the
technologies we have
which is quite pessimistic i must say so
several centuries that's what i would
give
not unless we get our act unless we
become more intelligent
than the newspapers report every day
okay
point number one second and and by the
way this is relevant i should say
because there was a report about
uh perhaps a radio signal detected from
proxima
centauri what do you make of that signal
oh i think it's some australian guy with
a cell phone next to the observatory or
something like that
because it was the parks telescope in
australia
okay i was like yeah okay so it's no
human
created noise yeah which is always the
worry
because actually the same observatory
the parks observatory
uh detected a couple of years ago some
signal
and then they realized that it comes
back
at lunch lunch time yes and they said
okay what could it be and then they
figured out that it must be the
microwave oven in the observatory
because
someone was opening it before it
finished and it was creating this radio
signal
that they detected with the telescope
every lunch time
uh so just a cautionary remark
but the reason i think it's human-made
without getting to the technical details
is because
of this very short window by which we
were transmitting radio signals out of
the lifetime of the earth
you know as i said 100 years out of four
and a half
billion years that the earth existed so
what's the chance that another
civilization a twin civilization of ours
is transmitting radio signals exactly at
the time that we are looking
with our radio telescopes yeah ten to
the minus
seven you know so and the other the
other argument i have that is
uh is that they detected it in a very
narrow band of frequencies and that
makes it
i'm not you know it cannot be through
natural processes
a very narrow band just like some
radio transmissions that we produce
but if it were to come from the
habitable zone from a transmitter on the
surface of proxima b
this is the planet that orbits proxima
centauri
then i calculated that the frequency
would drift
through the doppler effect you know just
like when you hear a siren
uh on the street you know when the car
approaches you it has a different pitch
than when it goes recedes away from you
that's the doppler effect
and when the planet orbits the star
proxima centauri
you would see or detect a different
frequency when the planet approaches us
as compared to when it recedes so there
should be a frequency drift
just because of the motion of the planet
and i calculated that it it it must be
much bigger than
then observed so it cannot just be a
transmitter sitting on the planet
and sending another direction a radio
signal unless they want
to cancel the doppler effect but then
they need to know about
us because in a different direction it
will not be canceled only in our
direction they can cancel it
perfectly so there is
this direction of proxima centauri but
i have a problem imagining a transmitter
on the surface
of a planet in the habitable zone
emitting it
but my main issue is really with the
likelihood
given what we know about ourselves right
in terms of the durations the
civilization the copernican principle
so nevertheless this particular signal
is likely to be uh human interference
perhaps but
um yeah do you find the proxima be
interesting or the the more general
question is
do you think we humans will
venture out into outside our solar
system
and potentially colonize other habitable
planets
actually i am involved in a project
whose goal is to develop the technology
that would allow us to leave the solar
system and visit the nearest
stars and that is called the star shot
in 2015 in may 2015
an entrepreneur from silicon valley yuri
milner came to my office at harvard
and said would you be interested
in leading a project that would do that
in our lifetime because as we discussed
before to traverse those distances
you know with existing rockets would
take tens of thousands of years
and you know that's too long you know
you
for example to get to proxima centauri
with
the kind of spacecrafts that we already
sent like new horizons
or voyager 1 voyager 2
you you need you you needed to send them
when the first humans left africa so so
that they would
arrive there now yes and you know that
that's a long time to wait
so yuri wanted to do it within our
lifetime yes 10 20 years meaning
it has to move at a fraction of the
speed of light so can we send a
spacecraft that would be
moving at the fraction of the speed of
light and i said let me look into that
for six months
and with my students and postdocs we
arrived to the conclusion that the only
technology that can do that
is the light sale technology where can
you explain it
uh you basically produce a very powerful
laser beam
on earth so you can collect sunlight
with photovoltaic cells or whatever
and then convert it into
stored energy and then produce a very
powerful laser beam that is
100 gigawatts and
focus it on a sail in space
that is roughly the size of a person
a couple of meters or a few meters that
weighs only a gram
or a few grams very thin
and through the math you can show that
you can propel such a cell if you shine
on it for a few minutes
it will traverse the distance that is
five times the distance to the moon
and it will get to a fifth of the speed
of light sounds
crazy but i've talked to a bunch of
people and they're like i know it sounds
crazy but it's actually
it will work this is one of those i
it's just beautiful i mean this is this
is science and
the point is people didn't get excited
about space since the apollo yes uh
era and it's about time you know for us
to
go into space a couple of months ago i
was asked to participate in a debate
organized by ibm and bloomberg news
and the discussion centered on the
question
is the space race between the us and
china
good for humanity oh interesting and all
the other debaters
were worried about the military threats
yeah
and i just couldn't understand what
they're talking about because
military threats come from hovering
above the surface of the earth right
and we live on a two-dimensional surface
we live on the surface of the earth
but space is all about the third
dimension getting far from error
so if you go to mars or you go to a star
another star
there is no military threat what are we
talking about
space is all about you know feeling that
you know we are one civilization in fact
not fighting each other
just going far and having aspirations
for something that goes beyond military
threats
yeah so why would we be worried that the
space race will lead
that's actually brilliant i didn't you
know there's some it does
in our discourse about it the space race
is sometimes
made synonymous with like the cold war
or something like that right or with
wars but
really yeah there was a lot of ego tied
up in that i remember i mean it's still
still to this day there's a lot of pride
that russians the soviet union was the
first of space and there's a lot of
pride in the american side that was the
first on the moon
but yeah you're exactly right like
there's no aggression there's no wars
and and beyond that if you think about
the global economy
right now there is a commercial interest
that's why jeff bezos and elon musk are
interested about
you know mars and so forth there is a
commercial interest which is
international it's not
it's driven by money yes not by name by
pride
and you know nations can sign treaties
first of all there are lots of trees
that were signed even before the first
world war and the second world war and
the world war took place so
who cares you know like humans treaties
do not
safeguard anything you know but beyond
that
even if nations sign treaties about
space exploration
you might still find commercial entities
that will
find a way to get their launches and you
know so
i think we should rethink space it has
nothing to do with national pride
once again nothing to do with our egos
it's about
exploration and the biggest problem i
think to human
in human history is that is is that
humans tend to think
about egos and about their
their own personal uh image
rather than look at the big picture you
know
we will not be around for long we are
just occupying a small space right now
let's move out of this you know the way
that oscar wilde
said i think is the best he said all of
us are in the gutters
but some of us are looking at the stars
yeah and the more of us are looking at
the stars the likelier we are to
uh to this for this thing for this
little experiment we have going on to
last
last a while as opposed to end too
quickly
i mean it's not just about science of
being humble it's it's about the
survival of the human species
as being is being humble to me it's
incredibly inspiring the starshop
project of
i mean there's something magical about
being able to go to another
habitable planet and take a picture even
i mean
within our lifetime i mean that that uh
with crazy technology too which is
it's i should tell you how it was
conceived so
um i was at the time um so after six
months passed
after the visit of yura miller uh i was
usually i go in december during the
winter break
i go to israel um i i used to go to see
my family and
i get a phone call just before the
weekend started they get a phone call
yuri would like you to present your
concept
in two weeks at his home and i said well
uh thank you for letting me know because
i'm uh actually out of the door of the
hotel
to go to a goat farm in in the negev in
the southern part of israel with because
my wife wanted to have sort of
um to go to a place that is removed from
civilization so to speak
so we went to that goat farm
and you know i need to make the
presentation and
there was no internet connectivity
except in the office of the goat farm so
the following morning at the 6 a.m i sit
with my back to the
office of that goat farm looking at
goats that were newly born
and typing into my laptop the
presentation you know the powerpoints
presentation about
you know our ambitions for visiting the
nearest star
and that was very surreal to me that
[Laughter]
oh like our origins in many ways this
very primitive origins
and uh our dreams exactly of looking out
that is brilliant
so that is incredibly inspiring to me
but it's also
inspiring of putting humans
onto other um moons or planets i still
find going to the moon really exciting i
don't know maybe i'm just a sucker for
it but
it it's really exciting and mars which
is a new place a new planet
another planet that might have life i
mean there's something magical to that
or some traces of previous life you
might think that humans cannot really
survive
and and there are risks by going there
but my point is
you know we started from africa and we
got to apartment buildings in manhattan
yes right it's a very different
environment from the jungles to
live in an apartment building in you
know a small cubicle
um and you know it took tens of
thousands of years but
humans adapted right so why couldn't
humans
also make the leap and adapt to a
habitat in space you know that
now you can build a platform that would
look like
an apartment building in the bronx or
somewhere
but have inside of it everything that
humans need
yes and it just like the space station
but bigger
and it will be a platform in space and
the advantage of that
is if something bad happens on earth you
have that
complex where humans live and you can
also move it back and forth depending on
how bright the sun gets
because you know within within a billion
years
within a billion years the sun would be
too hot
and it will boil off all the oceans on
earth so we cannot stay here for more
than a billion years that's for sure
yes so that's a billion years from now
uh
i prefer like shorter term deadlines and
so
and that's i mean there's a lot of
threats that we're facing currently do
you find it exciting
the possibility of uh
you know uh landing on mars and starting
little like
uh building a manhattan style apartment
building on mars and
and humans occupying it do you think
from a scientific from an engineering
perspective that's uh
that's a worthy pursuit i think it's
worthy but
the real issue that is often uh
underplayed is the risk to the human
body from cosmic rays
these are energetic particles and we are
protected from them
by the magnetic field around the earth
that blocks them but if you go to mars
where there is no such magnetic field to
block them
then you know a significant fraction of
the brain cells in your
your head will be damaged within a year
and the consequences of that are not
clear i mean
it's quite possible that humans cannot
really
survive on the surface now it may mean
that we need to dig
tunnels uh go underground or create some
protection
this is something that can be engineered
yes uh and you know we can start from
the moon and then move
to mars that would be a natural
progression but it's a big
uh issue that needs to be dealt with i
don't think
you know each showstopper i think we can
overcome it but
you know just like anything in science
and technology you have to work on it
for a while figure out solutions
and but it's not as rosy as elon musk
talks about
i mean elon musk can obviously be
optimistic
i think eventually it will boil down to
figuring out um
how to cope with this risk the health
risk yeah i mean
uh in defense of optimism i i find that
there's a at least a correlation if not
their best friends is optimism and
open-mindedness
is uh
it's a necessary it's preconditioned to
to do
to try crazy things and in that sense
there the sense i have about going to
mars if we use
today's logic of what kind of
benefits we'll get from that we're never
going to go
and make most decisions we make in life
most decisions we've made as a human
species are irrational
if you just if you look at just today
but if you look at the long arc and the
possibilities that it might bring just
like
humans left europe and yeah europe and
yeah and by the way it was destroyed
everybody and but it was a commercial
interest that drove that for trade
and you know it might happen again in
this context you have people like jeff
bezos and elon musk that are
commercially driven to go to space
yes but it doesn't mean that what we
will ultimately
find is not new worlds you know that
have nothing
you know much have much more to offer
than just commercial
interests and uh as a side effect almost
right yeah
yeah and then that's why i think you
know we should be open-minded and
explore
and however at the same time because of
the reasons you pointed out
uh i'm not optimistic that we will
survive more than a few centuries into
the future
because people do not think long term
and that means that we will
only survive for the short term i don't
know if you have
thoughts about this but what are the
things that worry the most about
uh from the great perspective of the
universe which is the great
filters that destroys intelligent
civilizations
but for our own species here uh
like what are the things that worry the
most yeah the thing that worries me the
most is that people pay attention to how
many likes they have on twitter
and rather than you know
basketball coaches tell the team players
keep your eyes on the ball not on the
audience
the problem is we keep our eyes on the
audience most of the time
yes let's keep our eyes on the ball and
what does that mean first of all in
context of science
it means pay attention to the evidence
when the evidence
looks strange then we should figure it
out
you know i went to a seminar about
umuamua at harvard
and a colleague of mine that is
mainstream conservative
would never say anything that would
deviate from
what everyone else is thinking said to
me after the seminar
i wish this object never existed
now to me i mean i just couldn't hear
that
what do you mean nature is whatever it
is you have to pay attention to it you
you cannot say i you know you cannot
bury your head in this
i mean you should bless nature for
giving you clues about things that you
haven't expected yes
and i think that's the biggest fault
that we are
looking for confirmations of things we
already know
so that we can maintain our pride
that we already knew it and maintain our
image not make mistakes because we
already knew it therefore we
expected the right thing yes but science
is a learning experience and sometimes
you're wrong
and let's learn from those mistakes and
what's the problem about that
why is why do we have to get you know
prizes
and why do we get to be honored and
maintain our image
when the actual objective of science is
learning about nature
and like you you've talked about
anomalies in this case
are actually are not things that are
unfortunate and to be ignored are
in fact gifts and should be the focus of
science exactly because that's the way
for us to improve our understanding if
you look at quantum mechanics nobody
dreamed about it
and it was revolutionary and we still
don't fully understand it it's a pain
for us to figure out so why do you so i
understand from the science
from the perspective that's holding our
science back
why do you have a sense that that's also
something
that might be uh a problem for us in
terms of
the survival of human civilization
because when you look at society
it operates by the same principles
there is uh people look for affirmation
by groups and they
you know people segregate into herds
that think like them especially these
days when social media
is so strong you can find your support
group
and you if you don't look for evidence
for what you're saying
you can say crazy things as long as
there are enough people supporting what
you say
you can even have your newspapers you
can have
everything to support your view and then
you know bad things
will happen to society because we're
detaching ourselves from reality
and uh if we detach ourselves from
reality all the destructive things that
naturally can occur
in the real world whether from nuclear
weapons all the kinds of threats that
we're facing
uh even we're living through a pandemic
the
uh suppose you know a much much worse
pandemic could happen
right and then we could sadly like we
did this one politicize it in some kind
of way and have bickering
in the space of twitter and politics as
opposed to
there's an actual thing that could
destroy the human species so the only
way for us to maintain
to to stay modest yes and learn about
what really happens is by looking for
evidence again i'm i'm saying
it's not about ourself you know it's
about figuring out what's around us
and if you close yourself by surrounding
yourself with people that
are like-minded that refuse to look at
the evidence
you can do bad things uh and throughout
human history that's the
origin of all the bad things that happen
yes and i think it's a key it's a key to
be modest and to look at evidence
and it's not a nuance now you might say
oh okay the uneducated person might
operate
no it's the scientific community
operates this way my problem is not with
people that don't have an academic
pedigree it's included everywhere in
society
on the topic of uh like discovery of
evidence surveillance civilizations
which is something you touch on in your
book
what that idea would do to
societies to the human psyche
and in general do you think and you talk
about the
uh i still have trouble pronouncing but
wager right what do you think
is uh can you explain it and what do you
think in general is the
effect that such knowledge might have on
human civilization
right so pascal had this wager about god
and by the way there are interesting
connections between theology
and the search for extraterrestrial life
you know it's possible that
you know we were planted on this planet
by another civilization that's you know
we attribute
to god powers that are that belong
really to technological civilization
uh but putting that aside uh pascal
basically said
you know let's there are two
possibilities either god exists or not
right and if god exists
you know the consequences are quite
significant
and therefore you know we should we
should consider that possibility
differently than equal weight to both
possibilities
and uh i suggest that we do the same
with omua mua or
other technological signatures that we
uh keep in mind the consequences
and therefore pay more attention to that
possibility now
some people say extraordinary claims
require extraordinary evidence my point
is that
the term extraordinary is really
subjective
you know for one person a black hole is
extraordinary for another
you know it's just a consequence of
einstein's theory of gravity
yeah it's nothing extraordinary yeah the
same about the type of dark matter
anything so we should leave the
extraordinary
part of that sentence just keep evidence
okay
so let's be guided by evidence and
even even if we have extraordinary
claims you know let's not
dismiss them because the evidence is not
extraordinary enough because
if we have an image of something and it
looks really strange and we say oh the
image is not sufficiently
sharp therefore we should not even pay
attention to this image or not even
consider
i think that's a mistake yes what we
should do is say
look there is some evidence for
something unusual let's try
and build instruments that will give us
a better image
and if you just dismiss extraordinary
claims
because the you consider them
extraordinary you avoid
discovering things that you haven't
expected and so
i believe that along the history of
astronomy there are many missed
opportunities
and i speak about astronomy but i'm sure
in other fields it's also true i mean
this is
my expertise for example you know the
astrophysical journal which is the main
primary publication in astrophysics
uh if you go you go beyond before the
1980s there are images that were posted
in the astrophysical journal
of giant arcs you know arcs of light
surrounding clusters of galaxies and
you know you can find it in printed
versions of the astrophysical journal
people just ignore
they put the image they see the arc they
say
who knows what it is and just ignore it
and then
in the 1980s the subject of
gravitational lensing became popular
and the idea is that you can deflect
light by the force of gravity and
then you can put the source behind the
cluster of galaxies and then you will
get these arcs
and actually einstein predicted it uh in
1940 and
you know so these things were expected
but
people just had them in the images
didn't pay attention so i'm sure there
are lost opportunities sometimes you
even in
existing data you have things that are
unusual and
exceptional and are not being addressed
yeah you actually i think you have the
article uh
the data is not enough from from quite a
few years ago
will you talk let's do you know we can
go back to the 70s and 80s but we can go
also to the mayan civilization
right the mayan civilization basically
believed in astrology that
you can forecast the outcome of a war
based on the position of the planets
yes and and they had you know
astronomers in their
culture had the highest social status
they were priests yes they were elevated
and the reason was that they helped
politicians decide when to go to war
because they would tell the politicians
you know the planets would be in this
configuration
it's a better chance for you to win the
war yes go to war
and in retrospect they you know they
collected wonderful data
but misinterpreted it because we now
know that the position of venus
or jupiter or whatever has nothing to do
with the outcome of world war one which
you know it
has nothing to do and uh so we can have
a prejudice
and collect data without actually doing
the right thing with it
that's such a pisces thing to say i
looked up what your astrological sign is
[Laughter]
well so you mentioned einstein predicted
that black holes don't exist
or just or exist in nature
when einstein came up with his theory of
gravity in 1915 november 1915
a few months later another physicist
carl schwarzschild
he was the director of the potsdam
observatory but he was a patriot a
german patriot
so he went into the first world war
fighting for germany but
while he was at the front he sent a
postcard to einstein saying you know a
few months after the theory was
developed
saying actually i found a solution to
your equations
and that was a black hole solution and
then he died a few months later
and einstein was a pacifist and he
survived so the the lesson from this
story is that if you want to work out
the consequences of a theory
you better wear pacifist but
but the point is that this solution was
known
shortly after einstein came up with his
theory but in
but in 1939 einstein wrote a paper
in the analysis of mathematics saying
even though the solution exists
i don't think it's realized in nature
and his argument was
if you imagine a star collapsing
stars often spin and the spin will
prevent them from making a black hole
collapsing to a point so i mean can you
maybe
one of the many things you uh you have
work on you're an expert in as black
holes can you first say what are black
holes
and second how do we know that they
exist
right so black holes are the ultimate
prison
you know you can check in but an
aromatic
even light cannot escape from them so
there are
extreme structures of space and time
and there is this so-called
schwarzschild
radius or or the event horizon of a
black hole once you enter into it with a
spaceship
you would never be able to tweet back to
your friends
and tell them by the way i asked the
students in my class freshman seminar at
harvard i said
let me give you two possible journeys
that you can take
i said suppose aliens come to earth
and suggest that you would border
spaceship
would you do it and the second is
suppose
you could board a spaceship that will
take you into a black hole would you do
it
so all of them said to the first
question
yes under one condition that i'll be
able
to maintain my social media contacts and
report back
share the experience with them i
couldn't but personally i have no
footprint on social media yeah which is
as a matter of principle yeah my wife
asked me when we got married
and i uh honor that and i told you
offline i need to get married just like
she's such a woman
she truly is a special agent well she
she was wise enough to recognize the
risk
but um it saves me time and it also
keeps me away from crowds you know i
don't
have the uh notion of what
a lot of other people think so i can
think independently think exactly yeah
exactly
but uh putting so i was surprised to
hear that for students
it's extremely important to share
experiences even if they go on a
spaceship with
aliens they still want to brag about it
rather than
look around and see what's going on this
is not an option when you go to the
black hole is exactly the point
so for the black hole they said no
because there obviously you can find
your death
after uh you get into it and you
you can crash into singularity there is
this singularity in the center so
inside the event horizon we know that
all the matter collects
at a point now we can't
really predict what happens at the
singularity because einstein's theory
breaks down
and we know why it breaks down because
it doesn't have quantum mechanics that
talks about small distances
we don't have a theory that unifies
quantum mechanics and gravity
so that it will predict what happens in
near a singularity
and in fact you know i once a couple of
years ago i had
a flood in my basement i mean
and i i invited the plumber to come over
and
and figure out and and we found that the
sewer was
clogged because of three
roots that got into it and we solved the
problem
but then i i thought to myself
well isn't that what happens to the
singularity of a black hole because
the question is where does the matter go
you know if you know in the case of
a home i never thought about it but the
water all the water that we use
goes in you know through the sewer to
some reservoir somewhere
and the question is what happens inside
a black hole and
one possibility is that there is an
object in the middle just like a star
you know and everything collects there
and the object has the maximum density
that we can imagine like
planck densities it's the ultimate
density that you can have
where gravity is as strong as all the
other forces
um so you can imagine this object very
dense object at the center that collects
all the matter
another possibility is that there is
some tunnel just like the sewer it takes
the matter into another place
and we don't know the answer where but i
wrote a scientific american essay about
it and
uh admitting my our ignorance it's a
fascinating question what happens to the
method that goes into black hole
i actually recommend it to some of my
colleagues that work on string theory
i uh at the closing of a conference i'm
i'm the founding director of the black
hole initiative
at harvard which brings together
astronomers physicists philosophers and
mathematicians
and we have a conference once a year and
at the end of one of them
since i'm the director i had to
summarize and i said
that i wish we could go on a field trip
to a black hole nearby and i highly
recommend
to my colleagues that work on string
theory to enter
into that black hole because then they
can test their theory when they get
inside
but one of the string theorists in the
audience nimar khan
hamad immediately raised his voice and
said
you have an ulterior motive for sending
us into a black hole
uh which i didn't deny but at any event
yes that's true that's true can you say
why we know that black holes exist
right so um it's an interesting
question because black holes were
considered a theoretical construct
and einstein even denied their existence
in 1939
uh but then um in the 19 in the mid
1960s uh quasars were discovered
these are very bright sources of flight
a hundred times brighter than their host
galaxy
which are point-like at this at the
center of galaxies and
it was immediately suggested uh by ed
salpiter
in the west and by yakov zeldovich
in the east that these are black holes
that accrete gas collect gas from their
host galaxy that are being fed with gas
and they shine very brightly because as
the gas uh
falls towards the black holes uh just
like water
um you know running down the the sink
uh the gas swirls
and then rubs against itself
and heats up and shines very brightly
because it's very hot close to the black
hole
by viscous by viscosity it it it
heats up uh and in in the case of black
holes it's the turbulence
the turbulent viscosity that causes it
to heat up
so um we get these very bright sources
of light
just from black holes that are supposed
to be dark you know nothing escapes from
them but
they create a violent environment where
gas moves close to the speed of light
light and therefore shines very brightly
much more than any other source
in the sky and we can see these quasars
all the way to the edge of the universe
so we have evidence now that when the
universe was
you know about seven percent of its
present age you know
infant uh already back then you had
black holes of a billion
times the mass of the sun which is quite
remarkable you know
it's like finding giant babies
in a nursery you know like how can these
black holes grow so fast you know less
than a billion years after the big bang
you already have a billion times the
mass of the sun in these black holes and
the answer is presumably there are very
quick
processes that build them up they they
they build quickly very quickly and so
we see those black holes
and that was found in the mid 1960s but
in 19
in sorry in 2015 exactly 100 years
after einstein came up with his theory
of gravity
the ligo observatory detected
gravitational waves and these are just
ripples in space and time so according
to einstein's theory the
the innovation the ingenuity of
einstein's theory of gravity
that was formulated in november 1915
was to say that space and time are not
rigid
you know they are they respond
to matter so for example if you have two
black holes
and they collide it's just like
a stone being thrown into this on a
surface of a pond
they generate waves disturbances in
space and time that propagate out at the
speed of light these are gravitational
waves
they create a space-time storm around
them and then the waves go
all the way through the universe and
reach us and if you have a sensitive
enough
detector like ligo you can detect these
waves and
so it was not just the message that we
received for the first time
gravitational waves
but it was the messenger so there are
two aspects to it one is the messenger
which is gravitational wave for the
first time were detected directly
and the second was the message which was
a collision of two black holes
because we could see the pattern of the
ripples in space and time
and it was fully consistent with the
prediction that schwarz had made for
how a black the space time around the
black hole is because when two black
holes
collide you can sort of map
from the message that you get you can
reconstruct what what really happened
and it's fully consistent
and in 2017 and
2020 there's two nobel prizes that's
right
uh uh that had uh to do with the
black holes can you maybe describe in
the same
masterful way that you already been
doing uh what those nobel prizes were
given for yeah so the 2017 was given for
the ligo collaboration for discovering
gravitation waves from collisions of
black holes
and the 2020 nobel prize in physics
was given for uh two things one
was theoretical work that was done by
roger penrose in the 1960s
demonstrating that black holes are
inevitable
when stars collapse and
it was mostly mathematical work and
actually stephen hawking
uh also contributed significantly to
that
frontier and unfortunately he is not
alive so he could not be honored
so penrose received it on his own
and then two other astronomers received
it as well
andrea guez and reinhard genzel and they
provided conclusive evidence
that there is a black hole at the center
of the milky way galaxy
that weighs about 4 million times the
mass of the sun
and they found the evidence from the
motion of stars very close to the black
hole
just like we see the planets moving
around the sun there are stars close to
the center of the galaxy
and they are orbiting at very high
speeds of order
thousands of kilometers per second or
thousands of miles per second per second
uh think about it yeah which
uh can only be induced at those
distances
if there is a four million
solar mass object that is extremely
compact
and the only thing that is compatible
with the constraints is
a black hole and
they actually made a movie of the motion
of these stars around the center
one of them moves around the center over
a decade you know six
over time scales that we can monitor and
um
it was a breakthrough in a way um
so combining ligo with
uh the detection of a black hole at the
center of the milky way and and in many
other galaxies like quasars uh you know
now i would say
black hole research is vogue you know
it's it's very much in fashion
you know we saw it back in 2016 when we
established
the black hole initiative yes you kind
of saw
that there is this excitement about in
in breakthroughs and discoveries around
black holes
which are probably one of the most
fascinating objects in the universe i
mean
it's up there uh they're both terrifying
and beautiful
right just and they capture the entirety
of the physics that we know about this
universe i should say the re
you know the question is where is the
nearest black hole can we visit it
and you know i wrote a paper with my
undergraduate student
amir siraj suggesting that perhaps
you know there could be if there is one
in the solar system we can detect it
because um i don't know if you heard but
there is a claim that maybe there is a
planet nine in the solar system uh
because we see some anomalies at the
outer parts of the solar system so some
people suggested maybe there is a planet
out there that
was not yet detected so people searched
for it didn't find it
it weighs roughly five times the mass of
the earth and we said okay maybe you
can't find it because it's a black hole
that was formed early in the universe
is that part so where do you stand up it
could be that the dark matter is made of
black holes of this mass you know we
don't know what the dark matter is made
of you could
it could be the black holes so we said
but there is an experimental way to test
it
and the way to do it is because uh
is there is the oort cloud of icy
rocks in the outer solar system and if
you imagine a black hole there
every now and then a rock will pass
close enough to the black hole
to be disrupted by the very strong
gravity
close to the black hole and that would
produce a flare that you can observe
and we calculated how frequently these
flares should occur
and with lsst on the vera rubin
observatory we found that you can
actually
test this hypothesis that's brilliant
and if you don't see flares
then you can put limits on the existence
of a black hole in the solar system
it would be extremely exciting if there
was a black hole if planet nine was a
black hole because
we could visit it you know and we can
examine it
and it will not be a matter of you know
an object that is very removed from us
another thing i should say is it's
possible that the black hole affected
life on earth
uh the black hole at the center of the
milky way
how you know that black hole right now
is dormant
it's very faint but we know that it
flares
when a star like the sun comes close to
it
the star will be spaghettified basically
becomes
a stream of gas like a spaghetti
and then the gas would fall into the
black hole and there would be a flare
and this process happens once every 10
000 years or so so we expect that
you know these flares to occur every 10
000 years
but we also see evidence for the
possibility that gas
clouds were disrupted by the black hole
because the the stars that are close to
the black hole
are residing in a single or two planes
and the only way you can get that is if
they formed out of a disk of gas
just like the planets in the solar
system formed so
there is evidence that gas fell into the
black hole and powered
possibly a flare and these flares
produce x-rays and ultraviolet radiation
that could damage life if if the earth
was close enough to the center of the
galaxy
where we are right now it's not very
risky for us
but there is a
[Applause]
theoretical argument that says the solar
system the sun
was closer to the galactic center early
on and then it migrated
outwards so maybe maybe in the early
stage of the solar system the conditions
you know were affected shaped by these
flares
of the black hole at the center of the
galaxy and that's why for the first two
billion years there wasn't
any oxygen in the atmosphere you know
who knows but
um it's just interesting to think that
you know from a
theoretical concept that einstein
resisted in 1939
it may well be that you know black holes
have influence on our life and that you
know it's just like discovering that
some
uh stranger
affected your family and
in a way your life and um you know if
that happens to be the case
a second nobel prize should be given not
not for
just the discovery of this black hole at
the center of the galaxy but
perhaps for the nobel prize in chemistry
for the effect that it had for the
fact for the for the interplay that
resulted in some kind of
uh yeah so yeah the chemical effect
bio biology i mean all those kinds of
things in in terms of uh
the emergence of uh life and the
creation of a habitable environment
that's so fascinating and of course like
you said dark matter like
black holes have some so they could be
the dark matter in principle yes
uh we don't know uh what the dark matter
is at the moment does it make you sad
so you've had an interaction and perhaps
a bit of a friendship with stephen
hawking
uh does it make you sad that he didn't
win the nobel well
all together i don't assign great
importance to prizes because as you said
you know
jean-paul starter who i admired as a
teenager
because i was interested in philosophy
when i grew up on a farm in israel
you know i used to collect eggs every
afternoon and i would drive the tractor
to
the hills of our village and just think
about philosophy read philosophy books
and
jean paul sata was one of my favorite
and he was honored with the nobel prize
in literature
he was a philosopher primarily
existentialist
and he said the hell with it you know
why should i give
um special attention to this committee
of people that get their self-importance
from awarding me
the price like what what's uh you know
why
why does that merit my attention yes so
he he gave up on the nobel prize
and you know that two benefits to that
one that you don't you're not
working your entire life in the
direction that would satisfy
the will of other people you know you
work independently
you're not after these honors just
for the same reason that you're if
you're not living your life
for making a profit or money you can
live a more fulfilling life because
you're not being swayed by the wind
you know of how to make money and so
forth
the second aspect of it is you know that
very often um you know these prizes
um they um
they distort the way we do science
because instead
of people willing to take risks
and instead of having announcements
only after a group of people converges
with a definite result
you know uh the natural
progression of science is based on trial
and error you know it's
reporting some results and perhaps
they're wrong but then other people find
perhaps better evidence and then you
figure out what's going on
and that's the natural way that science
is you know it's a learning experience
so if you give the public an image by
which
scientists are always right you know and
and you know some of my colleagues say
we must do that
because otherwise the public will never
believe us that global warming is really
taking place
right but that's not true because the
public would really believe you
if you show the evidence yes so the
point is you should be sincere when the
evidence is not
absolutely clear or where there are
disputes about the interpretation of the
evidence we should show us
you know the king is naked okay there is
no point in pretending
that the king is dressed yes saying that
scientists are always right
scientists are wrong frequently and
the only way to make progress is by
evidence giving us
the support that we need to make
airtight arguments so when you say
global warming is taking place if the
evidence
is fully supportive if there are no
holes in the argument
then people will be convinced because
you're not trying to fool them
when the evidence was not complete you
also show them that the evidence is not
complete and when there's holes you show
that there's holes and here's the
methodology we're using to try to close
those holes
exactly let's be sincere why pretend so
if there were no
in a world where there would there were
no prizes no honors
we would act like kids as i said before
we would really be
focusing on the ball and not on the
audience yeah the prizes
get in the way and it's it's so powerful
it
do you think in some sense the few
people have turned down the prize
made a much more powerful statement i i
don't know if you're familiar
with in the in the space of mathematics
with the fields metal
and uh google pearlman yes turned down
the prize
it's uh so he i've committed one of the
reasons i started this podcast is i
i'm going to definitely talk to putin
i'm go definitely talking to pearl and
people keep telling me it's impossible
i i i love hearing that because i'll
talk to both anyway but do you have us
do you have
a sense of um why he turned down the
prize
and is that a powerful statement to you
well what i read is that um
you're talking about the mathematician
the mathematician what i read is that
he was disappointed by the response of
the community the mainstream community
the mathematicians to his earlier work
where they dismissed it they didn't
attend to the details and and didn't
treat him with
proper respect because he was not
considered
one of them yes and i think that speaks
uh volumes
about the current scientific culture
which is uh
based on group think and on
social interaction rather than on the
merit of the argument
and on the evidence in the context of
physics so in mathematics there is no
empirical basis
you're exploring ideas that are
logically consistent
uh but nevertheless there is this uh
group thing and i think he was so
frustrated with his past
experience that he didn't even bother to
publish his papers he
just posted them on the archive and um
in a way
saying you know i know what what the
answer is
go look at it and then again in the long
arc of history
uh his work on archive will be
remembered and all the prizes
most of the prizes will be forgotten
that's what people don't
kind of think about is when you look at
roger penrose for example is another
fascinating figure uh
you know it's possible and i forgive me
if it's i'm sure of my ignorance but
he's also did some work on consciousness
he's been one of the only people who
spoke about consciousness
which for a longest time and is still
arguably
outside of the realm of the sciences
right it's still seen as a taboo subject
and and he was brave enough to explore
it
uh from a physics perspective from a
just a philosophical perspective but
like with the rigor
like proposing different kind of
hypotheses of how
consciousness might be able to emerge in
the brain and it's possible that that is
the thing he's remembered for if you
look hundred years from now
right as opposed to the the work in the
black holes which fits into the
kind of asp like the
fits into what the current scientific
community
uh uh allows to be the the space of what
is
and isn't science yeah it's really
interesting to look at people that are
innovators
where in some phases of their career
their ideas fit into the uh
social structure that is around them but
in other phases
it doesn't and when you look at them
they just operated the same way
throughout
and it's it says more about their
environment than about them
well yeah i i don't know if you know who
max tag mark is yeah just recently
talked to him
i just recently talked to him again and
he uh i mean he was a little bit more
explicit about
saying you know being aware which is
something i also recommend
it's like being aware where the
scientific community stands and doing
enough to get
like move along into your career in your
career and yeah
it's the necessary evil i suppose if if
you are one of those out of the box
thinkers
that just naturally have this childlike
curiosity which max definitely is one of
them
is sometimes you have to do some stuff
that fits in you publish and you get
tenure and all those
things but the tenure is a great
privilege because it allows you
to in principle explore things that are
not accepted by
others and unfortunately it's not being
being taken advantage of by most people
and
it's a waste of a very precious resource
yeah absolutely this space that you kind
of touched on
that's full of theories and
is perhaps detached from
appreciation of empirical evidence or
longing for
empirical evidence or grounding in
empirical evidence is
uh the theoretical physics community and
the interest in
uh unifying the laws of physics and
with the theory of everything
it's i'm not sure from which direction
to approach
this question but how far away are we
from
arriving at a theory of everything do
you think
and uh how would we
how important is it to try to arrive at
it
uh at this kind of goal of this
beautiful simple theory that unlocks
the very you know fundamental basis of
our
nature as we know it and
you know uh and how what are the kinds
of approaches
we need to take to get there yeah so in
in physics the biggest challenge is to
unify quantum mechanics with gravity
and i believe that once we
have experimental evidence for how this
happens in nature
in systems that have quantum mechanical
effects but also gravity is important
then
the theory will fall into our lap okay
but the mistake that is made by the
community right now
is to come up uh with the right theory
from scratch and you know einstein gave
the illusion that you can
just sit in your office and and
understand nature you know when he came
up with his
general theory of relativity but you
know first of all
perhaps he was lucky but it's not
a rule the rule is that you need
evidence to guide you especially when
dealing with quantum mechanics which is
really not intuitive and
so there are two places where the two
theories meet
one is black holes and there is a puzzle
there
it's called the information paradox in
principle you can throw
the encyclopedia britannica into a black
hole it's a lot of information
and then it will be gone because a black
hole
carries only three uh
properties or qualities the mass the
charge and the spin
according to einstein but then when
hawking
tried to bring in quantum mechanics to
the game he realized that
black holes have a temperature and they
radiate
this is called hawking radiation and it
was sort of
anticipated by
jacob beckenstein before him and hawking
wanted to prove beckenstein wrong and
then figure this out
and so what it means is black holes
eventually evaporate
and they evaporate into radiation that
doesn't carry this information according
to hawking's calculation
and then the question is according to
quantum mechanics information must be
preserved
so where did the information go
if uh a black hole is gone and where is
the information that was encoded in the
encyclopedia when
it went into the black hole and to that
question we don't have an answer yet
it's one of those puzzles about black
holes
and it touches on the interplay between
quantum mechanics and
gravity another important question is
what happened at the beginning of the
universe
what happened before the big bang and by
the way on that i should say
you know there are some conjectures
uh it's all in principle if we figure it
out if we have a theory of quantum
gravity
it's possible to imagine that we will
figure out how to create a universe in
the laboratory
by irritating the vacuum you might
create
a baby universe and if we do that
it will offer a solution to what
happened before the big bang perhaps the
big bang
emerged from the laboratory of another
civilization so it's like
baby universes are being born out of
laboratories
and inside the baby universe you have a
civilization that
brings to existence a new baby universe
just like
humans right we have babies and they
make babies so in principle that would
solve the problem of
why there was a big bang and also what
happened before the big bang yes so we
came
our umbilical cord is connected to a
laboratory
of a civilization that produced our
universe once it figured out
quantum gravity you know it's uh it's
it's baby big bang's all the way down
it's
just big bangs all the way up so if we
collect data about how the universe
started we could potentially test
theories of or it can educate us about
how to unify quantum mechanics and
gravity
if we if we get any information about
what happens near the singularity of a
black hole
you know if we yeah if we get a sense of
you know somehow we learn what happens
in this thing that would educate
so there are places where we can search
for evidence
but it's very challenging i should say
and my point is
you know the string theories they
decided that they know
how to approach the problem that they
don't have a single
theory there is a multitude of theories
and it's not
tightly constrained and they cannot make
predictions about
black holes or about the beginning of
the universe so so at the moment i say
we're at a loss
and the the way i feel about this
concept of the theory of everything
we should wait until we get enough
evidence to guide us
and until then you know there are many
important problems that we can address
you know why why bang our head against
the wall
on a problem for which we have no
guidance right we don't have a
good dance partner in terms of evidence
there's not exactly i mean it'd be
interesting
just like you said i mean the lab is one
place to create
universes or black holes but it'd be
fascinating if there's indeed a black
hole in our solar system that you can
interact with so the problem with the
origin of the universe
is all you can do is collect data about
it right you can't interact with it
well you can for example detect
gravitational waves that
emerged from that and you know there is
an effort to do that and that could
potentially tell us something
but um yeah uh it's a challenge
and that's why we're stuck so i should
say
despite what physicists portray that you
know we live through an ex
exceptional growth in our understanding
of the universe
we're actually pretty much stuck i would
say because we don't know the nature
of the dark matter most of the matter in
the universe we don't know what it is
and we don't know how the universe
started we don't know what happens in
this
in the interior of a black hole because
you've thought quite a bit about dark
matter as well
is do you have any kind of hypothesis
interesting hypothesis we already
mentioned
a few about what is dark matter and what
are the
uh possible paths that we could take to
unlock the mystery of dark
what is dark matter yeah so what we need
is some anomalies
that would hint what the nature of the
dark matter is
or to detect it in the laboratory there
are lots of laboratory experiments
searching but it's like searching for a
needle in a haystack because there's so
many possibilities for the
type of particle that it may be um
but maybe at some point you know we'll
find either a particle
or black holes as the dark matter or
something else
but you also may be sorry to interrupt
to comment about what is dark matter
like what it's just the name we're
assigned to what
so most of the community believes that
it's a particle
that we haven't yet detected it doesn't
interact with light so
it's dark but the question is what does
it interact with
and how can we find it and for many
years
physicists were guided by the idea that
it's some extension of the standard
model of particle physics
but then they said oh we will find some
clues
from the large hadron collider about its
nature
or maybe it's related to supersymmetry
which is a new symmetry that we haven't
found any evidence for
in both cases the large hadron collider
did not give us any clues
and other people searched for specific
types of particles in the laboratory and
didn't find any
a couple of years ago actually around
the time that i worked on umuamua
i also worked on the possibility that
the dark matter particles may have a
small electric
charge which is a speculation but
nobody complained about it and you know
it was published and
i regard it more as of speculation than
the artificial origin of umuah
and to me i apply you know as far as i'm
concerned i applied the same scientific
tools in both cases there is an anomaly
that
led me to that discussion which has to
do with the
hydrogen being called in the early
universe more than we expected so we
suggested
maybe the dark matter particles have
some small charge
but you deal with anomalies by exploring
possibilities that's the only way to do
it and then
collecting more data to check those and
searching for technological
signatures is the same as
any other part of our scientific
endeavor
we make hypotheses and we collect data
and i don't see any reason for having a
taboo on this subject
in your child-like open-minded
excitement and approach to science
you're i think to anyone listening to
this are truly inspiring
i mean the question i think is useful to
ask
is by way of advice for young people a
lot of young people
listen to this whether from all over the
world
and teenagers undergraduate students
even graduate students even p like
even young faculty even older faculty
they're all young at heart like there's
many
hearts you have advice for bullets focus
on the traditionally defined sort of
young folks that kind of graduate you
have advice to give to young people like
that
today about life maybe in general
maybe a life of curiosity in the
sciences
definitely um well first i should
confess that i enjoy working with young
people much more than with senor
and the reason is they don't carry a
baggage of prejudice
yes they're not so self-centered they're
open
to exploration uh my advice i mean one
of the
lessons that took me a while to learn
and
i should say i i lost important
opportunities as a result of that so
that i would regard it as a mistake
on my behalf was to believe experts
so quote unquote so
on a number of occasions i would come up
with an original idea
and then suggest it to an expert someone
that works in the same field for a while
and the expert would dismiss it most of
the time because it's new
and was not explored not because of the
merit
and then what happened to me several
times is that
someone else would listen to the
conversation or would hear me suggesting
it
and i would give up because the expert
said no
and then that someone else you know
would
develop it so that it becomes the
hottest thing in this field
and it have you know once it happened to
me multiple times
i then realized the hell with the
experts you know like
they don't know what they're talking
about they're just repeating them yes
they don't think creatively they are
being threatened by
innovation okay and um it's the natural
reaction of someone that cares about
their ego more than about the matter uh
that we are discussing and so i said
i would not i don't care how many likes
i have on twitter
i don't care whether the experts say one
thing or another i will basically
exercise my judgment
yes and do the best i can you know turns
out that i'm wrong
i made a mistake you know that's part of
the of the
scientific endeavor you know and um it
took me a while to recognize that and it
was a lot of wasted
opportunities so to the young people i
would recommend don't listen
to experts carve your own path
now of course you will be wrong you
should learn from experience
just like kids do but do it yourself
your father died
in 2017 your mother died in 2019.
do you miss them very much so
is there a memory uh that
fond memory that stands out or maybe
what have you learned from them
from my mother i mean she was very much
my inspiration for pursuing intellectual
work
because she studied at the university
and then
because of the second world war
after the second world war she was born
in bulgaria they they immigrated to
to israel and and she
left university to work on a farm
and later in life when
all the kids left home she went back to
the university and finished the phd
but she planted in me the intellectual
curiosity and
valuing uh learning as
or acquiring knowledge as a very
important
element in life and
and my love with philosophy came from
attending classes that she took at the
university
uh when i was a teenager i was
fortunate to go to some of these and
they inspired me later on and
i'm very different than my colleagues as
you can tell
because my upbringing was quite
different and the only reason i'm doing
physics or astrophysics is because of
circumstances i
uh at age 18 i was asked to serve in the
military and
the only way for me to pursue
intellectual work
was to work on physics because that was
the closest to philosophy
and i was good at physics so they
admitted me to an elite program
called alpiot that allowed me to finish
my phd
at age 24 and to actually propose the
first
uh international project that was funded
by the star wars initiative from
ronald reagan and that brought me
brought me to the us
to visit washington dc where we were
funded from and then
on one of the visits i went to
the institute for advanced study at
princeton and
met john bakal that later offered me a
five-year fellowship there
under the condition that i'll switch to
astrophysics at which point
you know i said okay i cannot give up on
this opportunity i'll do it
switch to astrophysics it felt like a
forced uh
marriage kind of arranged mary yes and
then i was offered the position at
harvard because nobody wanted that uh
they first selected someone else and
that someone said i don't want to become
a junior faculty at the harvard
astronomy department because the chance
for being promoted
are very small so he took another job
and then
i was taken in line they gave it to me i
didn't care much because i could go back
to the farm any day you know
and uh after three years i was tenured
yes and the
eventually a decade later became the
chair of this department
and served for nine years as the chair
of the astronomy department
at harvard but at that point it became
clear to me that i'm
actually married to the love of my life
even though it was an arranged marriage
there are many philosophical questions
in astrophysics that we can address
but i'm still very different than my
colleagues you know that
we're focusing on technical skills in
getting to this job uh so my mother was
really
uh extremely instrumental in in planting
the seeds of
stuff thinking about the big picture in
me
then my father he was you know he was
working in the farm
and we didn't speak much because we sort
of understood each other without
speaking
uh but what he uh
gave me is a sense of uh
you know that it's more important to do
things than to talk about them
i love the the the i mean my apologies
but mit
mind and hand i love that there's uh
that the root of philosophy that you
gain from
your mom and uh the the hand that action
is all that
ultimately in the end matters from your
dad that's that's
it's really powerful i if we could take
a small detour
into uh philosophy is there by chance
any books authors whether philosophical
or not you mentioned sacha that stand
out to you that were formative and
some small or big way that perhaps you
would recommend to others
maybe when you were very young or maybe
later on in life
well actually yeah i you know i read the
number of existentialists
that appealed to me because they were
authentic
you know satur you know he declined the
nobel prizes we discussed but he
also uh was mocking people that pretend
to be something better than they are you
know he was living an authentic life
that is sincere
and that's what appealed to me and then
albert camille was another
french philosopher that they advocated
existentialism
um you know that really appealed to me
that's probably my favorite extensious
camo
yeah yeah and he died at a young age in
an accident unfortunately
um and then you know people like
nietzsche
that uh you know broke
conventions and i noticed that
nietzsche is still extremely popular you
know that's
quite surprising uh it he appeals to the
young
people of today and the people that it's
the children it's the childlike wonder
about the world and
he was unapologetic you know it's like
most philosophers
have a very strict adherence to
terminology into the practices
academic philosophers and nietzsche was
full of contradictions and
and he just i mean he
it was just this big kid with opinions
and thought deeply about this world and
people are really attracted that and
surprisingly there's not
enough people like that throughout
history of philosophy
and that that's why i think this is
still drawn to him yeah to me what
uh stands out is his statement that
the best way to corrupt the mind of
young people
is to tell them that they should
agree with the common view you know and
uh
you know it goes back to the threat that
went through our discussion
yes you've you you've kind of suggested
that
we ought to be humble about our very own
existence and that our existence
lasts only a short time uh we talked
about
um you losing your father and your
mother
uh do you think about your own mortality
are you oh yeah
afraid of death i'm not afraid you know
what epicorus actually because was a
very wise person
uh uh according to lucretius
of course didn't leave anything in
writing but uh
he said that he's never afraid of death
because
as long as he is around death is not
around
and when death will be around he will
not be around so
he will never meet death so why should
you be
worried about something you will never
meet uh you know and
it's an interesting philosophy of life
you know you shouldn't be afraid of
something that you will never encounter
right but there's a finiteness to this
experience
we live every day
i mean i think if we're being honest
with you every day as if it's going to
last forever
we often kind of don't contemplate the
fact that it ends
you kind of have plans and goals and you
have these possibilities
uh you have a kind of lingering thought
especially as you get older and older
and older
that this is like especially when you
lose friends right
and then you start to realize um you
know
it it doesn't but i don't know if you
really are cognizant of that i mean
because
so but you have to be careful not to be
depressed by it because
otherwise you lose the vitality right so
i think
the most important thing to draw from
from knowing that
you are short-lived is
a sense of appreciation that you're
alive that's the first thing
but more importantly a sense of modesty
because
how can anyone be arrogant
if they kept at the same time this
notion that they are short-lived i mean
you cannot be arrogant because
anything that you advocate for you know
you will not be around
to do that in a hundred years so people
will just forget and move on you know
and uh if you keep that in mind you know
the scissors in ancient rome they
they had a person next to them telling
them don't forget that you're a mortal
you know there was a person with that
duty because the caesars
thought that they are all powerful you
know
uh and they had
for a good reason someone they hired to
whisper in their ear don't forget that
you're mortal yeah
well you're somebody one of the most uh
respected uh famous scientist in the
world sitting on the farm gazing up at
the stars
so you seem like an appropriate person
to ask the
completely inappropriate question of
what do you think is the meaning of it
all
what's the meaning of life that's an
excellent question and if we ever find
an alien that we can converse with i
would like to answer this
i would like to ask for an answer to
this question because
um would they have a different opinion
you think well they might be wiser
because they
looked around for a while but i'm afraid
they will
they will be silent i'm afraid they will
not have a good answer
and i think uh
it's it's the process that you should
get
uh satisfied by the process of learning
you should enjoy okay so it's not so
much that there is a meaning
i in fact there is as far as i can tell
things just exist you know and it's
um i think it's inappropriate for us to
assign
meaning for our existence because you
know we
as a civilization we will eventually
perish you know and
nothing will be you know just another
planet on which life died you know and
if you look at the big scheme of things
who cares like who cares and how can we
assign significance to what we are doing
you know so
if you say the meaning of life is this
well
it will not be around in a billion years
so what you know
it cannot be the meaning of life because
life you know nothing will be
wrong so i think we should just enjoy
the process
and you know it's like many other things
in life you enjoy
good food okay and you can enjoy
learning why because it makes you
uh appreciate better where you know the
environment that you live in
and sometimes people think religion for
example
is in conflict with science spirituality
con in conflict that's not true uh
if you see a watch and you look at it
from the outside
you know you might say oh that's
interesting but then if you start to
open it up and learn about how it works
you appreciate it more so science is the
way to learn about how the world works
and it's not in conflict to this
the meaning that you assigned to all of
this but it
helps you appreciate the world better so
in fact
i would think that a religious person
should promote science because it
gives you a better appreciation of
what's around you
you know it's like you know if you buy
uh in a grocery
buy something you know a bunch of
fruits that are packed together and you
can't
see from the outside exactly what kind
of fruits are inside but if you open it
up and study
you appreciate better the merchandise
that you get right so you pay the same
amount of money but
at least you know what's inside so why
don't we figure out what the world is
about you know what the universe
contains what is the dark matter
it will help us appreciate you know the
bigger picture
and then you can assign your own flavor
to what it means you know i i think
i'm truly grateful that a person like
you exists
at the center of the scientific
community gives me faith and hope about
this uh this big journey that we call
science
so uh thank you for writing the book you
wrote recently
you have many other books and articles
that i think people should definitely
read and thank you for wasting all this
time with me this is truly an honor
thank you so much not a waste at all and
thank you for having me i learned a lot
from your questions and your remarks
thank you thank you thanks for listening
to this conversation with avi loeb
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and now let me leave you some words from
albert einstein
the important thing is not to stop
questioning curiosity has its own reason
for existence
one cannot help but be in awe when he
contemplates the mysteries of eternity
of life of the marvelous structure of
reality
it is enough if one tries merely to
comprehend
a little of this mystery every day
thank you for listening and hope to see
you next time
you