To introduce our for
those of you who haven't met me

I mean this early in the school
physics and I got my Ph D.

degree from Hollywood where
killing the princess I lived and

I was interested in thank you.

This is a bit silly sad sad sad sad.

I'm very interested in.

Spec clothes and also stars and I hope
to have many interactions with you guys

very soon so to have this great
pleasure only to have the best I mean.

Yesterday I'll be on his Ph D.

degree from Hebrew University and
he's a member of the chair for

best to me department director of the
Institute for theory and computation and

the founding director for the passing
mission at Harvard University I mean

you run across a chair steady rise to
a committee for the predecessor status.

Of I mean he also serves as
the science fair director for

all of the National close
after Prize Foundation.

So I was a very proud of the research
interest including the first study

seeing the universe the platforms and
also the search for

extraterrestrial life I have based on
his great contribution astrophysics

I mean is this something he selected as a
run of the telegraph our most influential

paper in space by Time Magazine So
today we have the great

pleasure to have i'll here telling
us about the very interesting front

case of where cosmic modestly you looked
into life in there are numerous Thank you.

Thank you it's a great
pleasure to be here.

I was told that there are many students
in the audience and the rest of.

You going to be on life in
the university what I would like

to venture into is life is the biggest
environment that we can think off.

And obviously I would like
to know if there is life in

order to figure out if Georgia Tech
is not only the best and

the best in the clamp down but
maybe want to bigger scale.

So the fundamental question is.

This is one of the most important
questions seem more than science and

this goes back to how to
disagree with you and

recall Fermi and Noble or
is it the physicist.

At lunch with his colleagues
asked Where is everybody.

And.

If life exists out there why haven't
they visited us or maybe they did and

left and sought since then we started
this such we haven't found anything but

the search is still growing and now we
have a much better technology to address

this question So
when you look at this question it's

not a question that is the most off the
dating site it's actually a fundamental.

QUESTION In modern science.

There are many reasons for
us to be modest My mother used to tell

me that modesty is a great future but
after spending thirty years

to say professional astronomers I
found that one additional reason and

that's the richness of the universe around
us when you see how many things there are.

Is that they are not special and that's
the perspective I would like to take for

they are making the point that
we should the modest perspective

given that this big environment
that we're embedded in.

Now back centuries.

We find out that people thought that we're
at the center of the physical universe

that picture that they had in their mind
was that the Earth is at the center and

the sphere surround us and then there.

Was a very flattering to many people.

Especially then the church.

And that because humans occupied
a very special place in the universe.

It's still true if you look around
us we see this being roughly

spiritually symmetric but we look at
the center fit but now we know that.

Any point in the universe
works pretty much the same

on a very large scale the that everyone
is at the center of the universe.

But.

After.

The course where is the then we're not at
the center of the physical universe but if

you ask me of my colleagues the mainstream
astronomy many of them would say that.

It's quite possible that we're at the
center of believing the best of the bad

you couldn't of us in the sense that we're
special and that Earth is very rare.

And all of this is to study.

The lesson from the Copernican revolution
but all of this is quite understandable

given that it's a human tendency
to think that we're the center for

things when they look that my
daughters when they were much younger.

When they were in France they tended to
think that the world center some of them

and it's been my truth to be realised that
they've got a better perspective about

their life and realise that not
they're not at the center and

then it was it in miniature a few
min history to view that So

our civilisation takes time to mature and
an important step in the maturity

to find the standing of the universe would
be to recognise that we're not special but

you can speaking and the best way to
find out is by finding life elsewhere.

So that's what they're
trying to advocate and

there are many reasons
that people bring up for

the Earth maybe rarer we are at the right
distance from a star on the right of

my superstar the right planetary
mass they were planted her a bit and

so forth but this is true that you
can find evidence for the fact

that you're special if you restrict
your attention to how you snipped us but

that doesn't mean that your unique
because then you were wrong.

And you find other people
that look just like you so.

So in this context and
the couple are some bright discolor

many planets that they're probably
their star at the right distance

to have room temperature on
the surface and why is that important.

It's important because liquid water
may exist on the surface some and

the only fantasy.

That we're familiar with it
involves the chemistry of the water

organic Monaco's in between
the board turning that is possible

if the surface temperature is is that

roughly the temperature of the still quite
a bit the record would freeze if it's.

About three.

And so you can see here examples of
planets routed by a star with very similar

all surface temperature to that of
the Sun the Earth is right here and

see all these planets.

And then by.

Then about a quarter of the stars

you know about see which make up most of
the stars in our galaxy have a planet like

The Hobbit the bird zone around and
about a tenth of.

The stars that with a mass seen about
to the sun have such prominence so

the earth is.

Special and.

Civilization right now reached a major

milestone in the sense that we
developed at the core of G.

that allows us to search for
life on other planets and

with the drug business principle
of course make modesty.

So.

You know the Kinks and
the then it used to boast and you

know be very proud of themselves when they
come for the small piece of land on Earth.

But the fact that.

The quotes are from the stars have
a climate similar to the at the right

distance you can do the calculation and
find out about them to the power twenty.

How the planets like the Observer before
them of the universe that's more than

the number of grains of sand that
you find on the beaches on earth so.

The key to.

The small piece of land on the surface
of Earth is just back and the.

Grain of Sand.

That then scale before huge beach.

Making very proud of yourself.

Trying to focus on is laughter.

And that means the chemistry.

Of liquid water and to heavy crude water.

From a sphere because if you take.

This.

Up in empty space it will go
directly into gas face and

if you're going to face that
of water the only way to

get liquid water is if you have
an external pressure around and

then an external pressure means a gas
that is somehow kept together by

gravity on the surface of a planet so the
planet needs to have a large enough mass.

To spear the atmosphere is
extremely important for

us not only because we breathe the oxygen
it's also because it has a pressure but

the last week with water to exist if there
wasn't enough Mr There wouldn't be any.

And so what you need is a big enough
planet that it can hold on to its

atmosphere such that the cold
water will exist on the surface.

And there is a warning sign OS It has
about a tenth of the mass of the earth.

And it doesn't have enough of spirit and
we don't see any creature crawling

on itself is this right no.

The.

Tiny astronauts that we are familiar
with these are quote probably greats.

Or those who read the birth
of the microscopic size

less than a meter in size and
believe everyone.

On earth and they seem to sustain extreme
environments so about a decade ago.

There was a space mission that
took some of them to space and

they suffered a duration and

they were exposed to extreme which are
valid through the Asian cost me craze and

when they were brought back to earth
after a week and a half or so.

Continued to reproduce
perfectly healthy embryos.

And there were if you put
them under extreme conditions

like a few degrees still
ten degrees Kelvin or.

In a boat well.

They can survive before admitting to and

out of town and then you put them
back in the water they leave.

So in fact this kind of creatures
could survive on a piece a frock.

As it's run through space for a bit
Life can be transferred between planets.

And just what the.

Storm is this.

How the blue planet the nearest star
it's garbage trucks that must and

power for right there are so
great and also a planetary system.

Seven planets around another stab at this.

A little bit farther away two and
a half times.

You can see the pilots
here three of them in F.

and Jenny how can that be
the result of the stars.

Several tens of thousands closer to
the star than the Earth is from the sun

simply because the stock has only eight
percent of the mass of the sun so it's

much fainter and you need to get closer
to the furnace in order to keep yourself.

And so that the bozo is much closer in.

And you can see these ballots
in comparison to Venus Earth and

Mars we don't know if there's life
on them but the system is only.

Thirty or so away or so and
we can easily look for them and so.

Interesting.

To look at these planets in more detail
and perhaps try to figure out if if there

is life if they have enough to spare and
if there is evidence for oxygen for

example in the atmosphere since these
planets of transiting the host stars so

you can look for the flag that this
passing through that up was fair and

by that looks for the fingerprints of
molecules that are indicative of fluff

what you seem to spot is
the size of those planets and

because of the different planets in the
tropics one system the three Hobbit the.

One.

And one G.

and then sort of bluish cars here and
they have roughly the size and

the mass of the earth and
they're in the habitable zone.

Now so the lifespan of the star since
it has a percent of the mass of the of

the sun life then is much more than
the current age of the universe

there's a look at it you can think
of a status a nuclear reactor or

the burns the nuclear fuel and if
the star is less massive than the Sunday

it's quarter its interior is close a very
small slow me down south it looks much

longer even both has less fuel if it burns
that much more slowly than the sun and

so the most common stocks are about
the tenth of the mass of the sun and they

could be for up to ten true or nearest
a thousand times longer than the sun.

It just so happened that next to
a star but has roughly the age of

his last one comparable to the age of
the universe today but if you wanted.

To be close to a star athlete burn for

a much longer period of time then I have
the tropics Proxima Centauri would be

very good it's Proxima Centauri has
twelve percent of the mass of the sun so

the sun is here is the mass of
the star and that life down the mouse.

Is one sort of mass by definition and
drop east has eight percent of that and

the lifetime is a thousand times
longer than life than if the sun.

And so.

This factor of four thousand means that
the distant future stars like drop is

the only one so wrong.

If you go into the past you can find
the time when the very first pass from

the universe and that was when universe
was about one hundred million years old.

So.

About a factor of five hundred
one percent of the present age of

the universe that's when Stoss
started performing the universe so

an interesting question to ask is
whether we find the sun today.

Much earlier and if so how.

Of the universe.

And how fast.

Into the future will it continue and
when is the last time

to find out if in the universe is it today
around the sun in the distant future.

And so that's what's become created the
likelihood of assuming that every star as.

A sample a constant probability to
have a habitable planet around it.

Then just follow the stuff
emission Historia and include

the lifetime of stars to figure out how
many stars would exist at any cost me.

And then figure out you know what is
the likelihood for me good point about.

How did the planet give us and
if the stars to have

habitable planets then it does say that
it seemed a future that probability peaks

that's the black line here so when they
give us a just about another factor for

thousand that's when life would be most
common simply because that's the longest

period of time that we have for
stars to shine.

But if you want to stars like
the sun to a past life then

no is the peak of the probe of this
event or the likelihood so you

might think this is an academic exercise
and often you find professors writing.

Questions that sound to see if they
are asking how many angels can sit on

the perfect pin or but
this is not a computer hypothetical

question because we can actually check
whether the enormous task have planets

with life and then we can look at
Proxima Centauri Trappist one and

figure out whether we are in a very
special environment around the sun or the.

First hazardous for
life there is a good reason for

that because the planet is
very close to the staff so

it's exposed to much stronger pressure off
the stellar wind that could strip the.

Atmosphere off the surface of
the planet and also stars.

First when they're young so
that could also be hazardous for life but

we can figure out with these
nearby stars have a life form but.

In principle one can also do
a kind of pollution went.

About it because the first time scale for.

The number of species
to babble on earth and

that's related to the not a few that is
impinging on the surface of a planet so

if you consider that has a different
mass than the sound in the model that it

produces is different when mixed with
a massive star you need power for

a sun glasses to block the movie because
the stars are hotter and so most stars

simply have a bit characteristic doubling
time of the number of species which is.

That it takes.

The edge of the universe to
introduce many species in the stars.

But in the case of the sun we just we have
enough fuel to have a lot of species and

it one can calculate the number of
species develop exponentially on

the characteristic scale of the star and
one finds that stars

produce enough U.V. to do that and
how many stars are too short lived and

so there is that window or own stars like
the sun where the number of species is

growing to be enormous as
we find here on Earth.

Now you might ask What is the nearest
star you can do the stabbing.

It's actually a question of three
stars a triple system that is

called Alpha Centauri it happens to
be right no closer to the sun and so.

Of tens of millions of fears that were out
of the record there will be another start

with we've come close.

But for
now this cryptosystem is the closest and

it shows a triple system some
common the fact that the nearest

The nearest star is in that system and
actually.

This system is composed of two stars
just like the sun ifas and carry me

plus another third stab which is what's
mustn't our twelve percent of the mass

of the sun and
it turns out the nearest star.

Is a minute.

Round it it's close proximity.

And this was discovered just.

A year and a half ago.

Now this star has twelve percent
of the mass in the sense of

this planet is twenty times closer to
the star than the Earth is from the sun.

The days.

If you like to live on the planet

enjoy celebrating your birthday
everything within a half.

The thing about this planet
is that it's facing the stuff

with the same side because it's so
close to the start that it gets tied up.

Just that the moon shows us the same face.

This planet is not going to show
the same face with a star and

without meaning it means is that you have
a permanent base and a permanent night.

So when I mentioned that to
my daughter who is right for

solo She said I would like to.

So process if I had been given
an opportunity to bat house

on this this planet well.

Where she would spend
sleeping in the second.

Location.

Just a bit and permanent sense that strip
between the two sides where you can watch

the sunset throughout your life it never
sets the sun never sets on some planets.

In summer but the US trip to
the real estate value peaks.

And if you don't.

Take it out with your nearest
block the real estate agent.

So the key question is does
proximity have a not most feared

because without an atmosphere or
not have life as we know it and

there is a simple way to tell if
the planet moves around the star.

We see.

The sun parts of feet facing us so
we don't know the planet but

we will be able to tell how
the temperature of the surface that this

rabbit thing in our direction changes so
when you see the Nightside see a quarter.

Of the action and
when we see the day sad to see a red.

Depending on the implication
of course of the earth.

So the temperature contrast between
the two sides can be figured out from

the valuation then Mission temperature or
the color of the system it's a small

variation because the palette reflects a
small fraction of the light of the stop so

if you want to save the planet you're just
collecting the light that you get from bed

from the planet emitted by
the planet plus there were selected.

Last the.

The start so the mix of all three

shows a small modulation as
the planet moves around a star and

from that you can infer the temperature
contrast of the planet principle.

The the.

Much been the crowd might side if there
is not much fear if it's just better.

But if you put in.

The Wraith temperature contrast because
the atmosphere transfers heat the ruins

a powerful winds and so.

In principle can tell the difference
between the temperature contrast of better

off and rock dressed up with with
an atmosphere or with oceans and

that you could live within a few years
with the James Webb space telescope

that is scattered for launch in the middle
of two thousand and nineteen the moment

so we just need to wait a few years and

if they mentioned the estate values
likely to peak just in between the and

the night side this is a father
that they took last summer and

it is the house where I
had the inspiration for.

The sunset the permanent
Sunset Strip I thought.

It's been a place rather you
don't lose this after a few.

Minutes it lasts for a lifetime.

As it turns out we had a visit a few
months ago I don't know if you

look at the soap in the news.

This was a visit from outside
the saw system the first piece of

rock that was discovered to enter
the solar system that was not

in the solar system how do you know
because it's moving too fast it's actually

bound to the sun so it has a positive
energy it's moving its kinetic energy

is the latter then its gravitational
potential energy so that it's

bringing it to the proximity of
the sun and then taking it out and

it will leave the solar system and what's
special about this man is from the light

of the reflected sunlight we can tell that
it's ten times longer than it is wide and

the most extreme object within
the solar system before

this one was found to have
roughly one to St and

Russia between the length and the width so
the very first visit looks unusual.

So it's sort of like inviting.

Having dinner at home and inviting people
from outside instead of the first person

that comes in from the street it
seems to be extremely different.

Then.

That's the only person that
looks like that there must be

appropriation of people.

So this makes this really
think the nature of

first of all how such
an object could have been me.

Is a drop over time.

And then.

For me the first thing that the first
thought that they had in my head

was maybe it's a probes sent to us by
some extra terrestrials exemption so

we actually tested for that and
put the in it off in roughly a tenth of

the transmission of a cell phone on
the radio transmission from this object so

it's just a piece so far but it's
amazing that you can get such a group.

Limit a tenth of a cell phone
on in this room to go to object

with existing graduate schools just to
show you how powerful his reg astronomy.

The subject in principle could transfer
from the planetary system to another.

And the way you can do that
is because the Sun and

Jupiter actis the fishing nets so that.

The drop of them are surround the sun and

if a third like this passes through
it in principle it can give some of

its energy to drop it if it causes close
enough and I suppose is that then a G.

to get back to the Sun So
that's a way of trapping objects but

the Jupiter sound system and

the solar system access to fishing nets
that collects fish from being just that.

Space and then by examining the fish
the fifth Quebec's you can learn

a lot about what's out there.

And so that's an interesting
opportunity to figure out.

You know.

Such objects in the solar
system that were captured.

In terms of Alpha Centauri after some much
more effective fishing net because they

have both sort of mass rather than Jupiter
having a thousand percent of mass So

recovery they did you could have
an Earth like planet captured.

For something and
the system in the same fashion.

How do you tell if a comet originated

from outside the solar system
you can study cometary tail.

If you tears any and
the rotor vapor would tell you

that the pressure Fox engine for
example or the Comet has.

Came from outside the solar system it
would have a different as the pressure

compared to comets that we find for
most objects within the solar system.

In principle there could be
under the surface a fit a frozen

object even if it's not
very close to a star.

And one can calculate it is
the label that forms around.

Those hitting from radioactivity
within the object.

Because the thickness of the ice is it.

If you minus at most so

in principle but dripping through the ice
you can then cobweb existence of perhaps

fish under the ice some people want
to do that on Europa for example.

Could visit.

A planet at least pass near a flag and
take photos and

see if the planet is green with a has
vegetation maybe it has ocean it's blue.

It's just visit Brown.

And so.

To send and come.

To take photographs of proximity for
example but the thing is that.

We would like to do it
within our lifetime.

Within that time.

Much more interesting to be gauging
a project that would not take a very

long period of time to reach the target if
you were to use rockets that are currently

used by NASA it would take eighty
thousand years to reach office in town or

Proxima Centauri.

We can't wait one hundred thousand
years it's to Rome for my taste.

So the question is since the distance
to the nearest star is four

light years that means it takes like four
years through to traverse this distance.

It's good if you want to make it within a
couple of decades roughly of the time the.

Can imagine myself still think
incoherently about these issues.

Then you need to send a spacecraft
at the fifth of the speedo for that.

And so how do you do that well
we came up with one solution.

You know I thought about it with
my students and post-docs and

there was no other method that
seemed to be feasible but

as I mentioned to the founder of
this project and the person that.

Brought it to life.

And property from a Silicon Valley I told
him that it's just like getting married

you just need one solution to the problem
you have you done with it and so

it's good we can be happy that we have
one solution could have been zero and

you don't need more than one but it's
very challenging dissolution the pattern

described it's called that the project is
called Stop shot and a beer is to push.

A sale laser to a fifth
of the speed of light and

it would take about a couple of
minutes a power one hundred G.

go up laser So that's roughly
the amount of power needed for

lift off of the space shuttle over roughly
the same amount of time except this.

Model for energy is given through
a few grams of material so

this say be very thin size or
fit if you need to send.

Roughly a ground.

Tronics on the say.

That you can pack into a single ground
that includes common navigation devise

communication devices the kind of things
you find the guts of the cell phone if you

strip that interface and
the packaging so let

me show you a short video that restricts
the motivation behind this project.

And then then describe a few more
details about the related mechanism for

the launch.

Here.

This is.

Most of our history with.

Me blinders.

When we come.

It was done for centuries ago.

Some more pictures.

And the last.

Place starts.

Its.

Cover.

Is a continuity of MUDs.

Is standing on the shores
of the Johnson before us.

Looking out across it that
we're not to stop asking.

I wonder what's there.

The most.

Recent tar.

The steel of yours.

And I see.

How your boat was hundreds of your stars.

And those who are teens it was only you.

In the last decade we have a story or
two since lives on our solar system.

It's now estimated that there
are several years ahead of all eyes

are galaxy Moammar.

I would contend he has all
the stars he's worn off.

He had taken to the sky.

We have stepped off the earth.

We have walked on.

We have landed up on our.

Adventure to the edge of space.

Where nothing.

So this was this figure was used the bring
the announcement the public announcement

of the project almost the couple of
years ago Stephen Hawking came for

the announcement.

And the physics behind it is similar
to a sailboat that is being pushed by

the most recent off the set of
both here we're talking about like

the particles of light bouncing off
the say it's pretty much the same.

And you can see the schematic in
restriction they destroy this.

City in space and we can do that
once a day when it's about a bit

sight of the laser and then then
the challenge is to create a coherent.

Of laser light that is
focused on a few meters.

Of the say and pushing it to a fifth of
the speed of light over a distance that is

roughly five times the distance to
the moon over a couple of minutes and

day one since.

It cannot maneuver much so you need to
send it in the right direction where for

example approximate.

Twenty years when the probes get there but
the good news is you can send many such

spacecraft in different and
each of them would be relatively cheap

most of the investment is in
the infrastructure of the laser beam.

And then once they get the spacecraft
gets close to the planet Earth interest

it will take photographs off
it we become our own born and

then transmit then send them back or
the way to Earth and

then it will take another forty years for
the light to reach us so

together twenty four years if Europe
the mystic and then the spacecraft.

Send it in the direction of the sun
doesn't need to be more precise because

the spot is larger than
the Earth Sun separation and then.

Little bit that they're on earth that
well let's some of the forefronts and

on Vets it with the image that that
was taken so that's the concept

and that of course is what we're
contemplating what to think about.

Maybe if there is another civilization
that is much more advanced than they

already mustered this technology if they
had the nearest of time in fact if we ever

stablished cation it would be interesting
to ask them for answers to questions

that we we haven't been able to solve
because it would provide a shortcut for

us it would save us a bit of science and
technology development.

It would feel like cheating
in an exam because but

on the other hand the temptation for
finding you know questions to then and

system questions is
difficult to the client and

I think that would be the greatest benefit
that we can have that we would learn

although it with Lucas magic
to us that first for me.

If there is a medicine it is ish and
it has such an offer to push it right say

what then surely not necessary I
wanted to go to the nearest stars but

those are visit sites
within planetary system or

deliver those between the Earth mass
must say I want to show time scale.

You can imagine seeing evidence for that
in Flash yourself right because the demand

for the next round to Satan
will reach us but then.

Sweep across the sky because we're
moving this source is moving and so

forth so we will see a flash floods and
then that

is an interesting search that one can make
for exit through us or a civilization.

If you want to search for primitive life
the conventional approach is to look for

profit and
it's the transit the face of the stars so

they pass in front of it and
when they cross the.

The face of the stove big block a small
fraction of the light from the stock and

some of the light goes through
the atmosphere of the planet and

you can take a spectrum of it.

Fingerprints are various moderate
curious and from absorption.

Of those more to the spectrum and so
that's a good way for such for example.

For oxygen.

The exist in the atmosphere
of the earth if not for

life it's very reactive it would
go away within a million years so

finding want to go in combination
with the other gases like methane.

And other gases.

And the results already primitive
life at least on the planet and

the difficulty is that the size
of the earth is roughly

around percent of the size of the Sun So
in terms of.

Blocks on any one percent squad
which is then to the minus four

percent of a percent off the area
of the sun and the atmosphere is.

Even a smaller by the smaller
area because it is so

very thin sliver around the earth so
the contrast probably.

The fingerprints.

Of the.

Whole roof you have a stab at these
this roughly the size of the earth it's

much easier and such a study exists it's
the end result of the evolution of the sun

in the distant future within seven years.

The Sun.

Through its nuclear fuel.

Develop into a so-called white dwarf.

So in astronomy you find
all these objects that

there have been a politically
incorrect name such as.

Brown black or red John.

If these exist in astronomy This is
the future face off of the sun and

then it's basically a piece of
metal roughly the size of the of

the earth containing about this sixty
percent of the mass of the sun.

So a very dense object and after a few

years it will have their roughly the same
temperature as the sun has on its surface.

But even smaller and if there is a planet
like the Earth orbiting a like war and

by the way that many White walks in our
neighborhood as many people to the number

of solar system because the sun is at
the middle of its lifespan right now and

it has a lifetime comparable
to the age of the universe or

that plenty of stars that about Morse but

I know they were formed in the sun and
so the only question is whether the.

Planets exist there on them and then
it will be much easier to see this that

absorption feature that I was talking
about before so it would be interesting to

assess for oxygen in the atmosphere and
also for industrial pollution.

Industrial pollution.

As a signature of not so
intelligent life but then it would be.

Very curious that they're
not produced naturally.

And that it could be intentional if
the planet for example was to color of.

Hobby did otherwise and

you couldn't tell from the planet
by introducing a blanket off.

Matilda didn't make a greenhouse effect
and keep the planet well other than it was

supposed to be and
then a civilization might settle on it so

it would be interesting to check for
that you can also check for.

Solar cells or photovoltaic cells made
of silk on the surface of a planet.

Well for example when you have
a kind of planet like Proxima B.

For example one side is
facing the star and has a.

Is way ruminated the other
side is dark and

corded if you are civilization
moving up on it you would cause.

The they side with silicone and

transfer heat than light to the other
side and from a distance that

visible because the Dark Side dark
you know the if you look at then.

From the satellite you do see it's
we're not producing this much now.

As that they could be
from a great distance but

an advance it is Asian light
actually produce enough light for

us to not to see it and also hint
if we look again it they're very.

In that temperature of the surface
temperature of the planet northeast.

And finally vegetation as.

If you look at plants for
example they reflect.

Infrared radiation because they don't use
it for photosynthesis they just Was that

were provided by the engine so
there is a spectral edge.

And it looks just like
that the red in here

you see here is the wavelength
of the light microns so

infrared is right around here and
that is around here so

the plants are using all the radiation
that they can use it was provided for for

the synthesist But for
those with less energy than that

out in the infrared are not useful for
them so they just throw them back or

reflect them or consider the trash
by deficient they should so

what you see from a distance
you would see and

read the edge I read Spectro edge that
is that I'm sure that the earth is

much more reflective with wavelengths
longer been point seven microns and

the thing is somewhat sensitive to
the infrared photons but if there were.

Blended with the plants.

Very bright in the infrared and
this is the interval.

And so all the way to figure all of
existence of vegetation is to see that

the Spectro edge this red edge.

The reflectance on the surface of
a planet as it moves around the star so

if one side is always it
has been just a show and

you will see this red badge only
when that side is visible to you and

when the backside is visible not see it or
at the edge and what's

that's one way of telling that the reserve
education and the same can be done with.

Photovoltaic cells or so
cells they have also spectra ledge.

Short The ravings but
one can tell the things it is.

Finally I'd like to comment on.

Things that.

Affect our life and that they originate

in bit of true neutron stars so

interesting the smallest stars or
the most compact stars.

They have a size of twelve kilometer
That's roughly the size of a city.

Comparable to that of the sun
up to twice the mass of the sun.

Not only that you find neutron staffs and

some of them are spinning around their
axis and you see all through regular wave

submitted from the axis of
the actors the right house and

you see them coming back periodically
into view and these are stars but

not only that you find individual
process you also find binary process

a system of two Michelin stars in
the top to each other everything.

And such systems resemble.

Their mission of every fish in the waves
which are ripples in space standing so

have attended pendant system like.

This there are troops so
some match the space around them but they.

Generate purpose in space than
the propagate of the speed of light out of

that and there is no such
a fantasy from that albeit And so

the two come together and
eventually acquire less and so

into neutral stance smash into each other
and little bit of material from the other

four percent of a sort of mass gets
injected into space for space and

that is neutral rich material if you take
material from neutron star with with

a teaspoon at this proof
of material really is about

a thousand troops kilograms or
Thomas it's rough.

And then a teaspoon.

Expelled solid mass.

Into space that material that
gets it goes through reaction.

Neutral rich material that turns
into heavy elements So for

example and
if you do that isn't that has a great ring

this gold was produced in the creation
of two neutron stars that's

what the strongest believe it's one of
the main channels for producing gold.

Mazing that something like
that was once neutral stomach.

But it's not just growth it it's also for
example.

OK.

This is from the CO reference right so
I think whether civilizations that the.

Closer to neutral stance came together
we were both in the car wars they would

not be very long lived compared
to civilizations Father way

this neutron star stock
lesions very rare there were.

Two hundred thousand.

Years Cobell it seemed like the nuking way
we don't know exactly the rate it's being

debated right now but they're rare and
sort of variations in the balance

of these heavy elements you know
look at stars and we can measure for

example that abundance of people which
is also a very heavy element produced in

these neutral stock relations and
then European seems to vary

by up to in order for magnitude
in abundance relative to the sun.

Between from one spot to another so
there is no reason to suspect the for

example Moran does not vary
by an order of magnitude and

that's simply due to
the ability of the sources.

And so here's this.

It.

Is.

Elements.

Where most likely made in merging
neutron stars the other ways

to produce sediments and you know the most
calling is in the course of stars

you can burn hydrogen into helium and
so forth.

But these purple rounds were
produced in your from stun and

they could affect I did the job or
the economy or Fed Ex or

through a stress so keep that in mind
when you establish contact you want to

check what is that abundance of
your opium understand next to them.

If they might be peaceful.

And another thing.

Which is also produced.

In merging neutron star
systems is very important for

life if you start off more than only
the rights of abundance in a body.

The person without.

If you give too much more than that's
it actually poison so it's quite

remarkable that these elements have the
elements that they're really crucial for

right and
you can see the three that I mentioned

so it cost me a good
perspective about religion.

Teaches Us modesty.

And then.

It gives us a world view to.

The heavy elements that make these
were produced in the nearby supernova.

That assembled to make the solar system.

Except for one person.

Out there that makes our bodies
come back to Earth one person.

Who discovered the truth and
whose actions were put on the New Horizon.

Spacecraft So
it's making its way back to space.

So that's the only person that goes back
to being the still a new doing right now.

So.

They're trying.

That some course make meto takes for

a brief period of time on
this planet that we quote.

At the peak of star like the sun.

There is not lesson that we
can learn from astronomy.

Then.

The we're just a speck of dust in
this said big scheme of things.

Perhaps.

An object that is passing near
the solar system perhaps on.

A planet near another.

On a spaceship.

We should this is a very special
time that we live in and

we should do our best to work
without the prejudice and

to be open minded to work you
might discover Thank you.

Thank you.

So much.

Riba daily lives.

I got a very mundane question
the power supply needed for

the lasers to propel the stock shelf
is this just extraordinary or assist.

In principle that power can be provided
if you have a look I will power station.

This will store.

In some infrastructure for

example a bank of capacitor a sort of
flat flat will but they if you go through

the numbers it's just it's something
that's not one of the biggest challenges

the biggest challenge is constructing
a laser that has the right power.

And a laser beam.

Low power laser as coherently
such that you get the focus spot

that's a major challenge and would be
very expensive to build such a system but

then and we're counting on the fact
that in the distant future but

the cost will drop once there
is demand for another place.

But the.

Challenge is to make a sale
to reflect ninety nine

point nine nine nine percent of the of
the light of these impinging on it because

if you the results that absorbs more
than one part in one hundred thousand.

It could burn up and

so there is a material science
challenge to do with the laser and

so the first step of the project we
are trying to address the laser.

Issue of incoherent.

And then the.

Challenge first and maybe about
a dozen experimental groups the.

Submitted proposals in
our view within our.

Being considered for
funding for the first.

Challenge and then the hope is that.

The better of the technology
within the next they could

to a level that will tell us inform us
whether it's worth pursuing father.

The second phase.

It's worth pursuing they would be.

Building a product of the things.

And the.

Boat and uterus and
then eventually the funds.

Thank you.

Could offer no sir it was really enjoyable
like that speech so I want to ask this

question because you brought this up like
we have if we meet it in a civilization we

can probably learn from their technology
and learn from their knowledge but so

several years ago I read a Chinese science
fiction named the three body problem and

in this novel they author
brought an idea of the dark

forest a theory so it's like in
order to maintain order to survive

in this galaxy which has
a limited amount of space and

resources a civilization must annihilate
us I was ations you know order to.

Make sure that it's survives so
I just want to ask

Are you confident enough to co-exist
in peace without a civilizations and

how do you make sure that we
don't come front the hostility.

Well let me first confess that.

Even though it sounds counter-intuitive
I don't like science fiction.

Because it does fiction.

Have a problem when I watch.

And read books because I was
I can't enjoy the book or

the movie because they realize that
something's going to be done in bathrooms.

Funded thing.

And so.

But nevertheless a good.

Group of thread.

Serious or books the you mentioned they
said wonderful things about them and then.

You work with people that
like science fiction.

In respect of the nature of
the civilization it's just.

Speculation for of course.

There is the.

Seeking civilizations would be less.

Most likely if you find.

If you stablished on but it may be
with the more aggressive type but

the point is that we already sent out.

Signals that we exist for a hundred
years and so there is a battle for a B.

way of say going out
which now is one hundred

one hundred light years in obvious.

You know if there is any
civilization within that void.

Here back sooner or

later it's too late now we can chase
those photons and bring them back.

So we all will be existence now of
course there are many stars within

a hundred light years the standards
on that would be more stars and

God within this expanding baboo and
then eventually we'll reach a point where

there would be a civilization but then it
would take a while for us to hear back.

I think it's actually proven not
to be to grip possibly transmit to

me the we exist just
because I mean it's a.

We can feel it once we
call it the enough data

if what kind of intentions perhaps they
have and discuss how to respond of course

that those are great distances usually
in astronomy so we have plenty of time

I go to the site how to respond or to
start running in the opposite direction.

Thank you for
sharing with us YOUR expect is.

And.

As a fundamental physicists looking at
a lot of what is consciousness if bad.

Bunch of.

Elements that.

Came out of.

Supernova.

Galactic explosions
traveling the sun G.-D.

is really remarkable I think in
the sense that it's based on physics but

it's the way that your
system is organized and.

Some.

Nature found ways to have to construct
systems that the much more efficient and

then we can pick and with with modern
technology like to think about it

the women brain how complicated it isn't
then some functions cannot be done yet

with computers and eventually
without the official intelligence

the way it's going but right now there
are still some benefits to human thinking.

If a job eventually when computers
were right on paper so I guess.

So it is remarkable not
just consciousness but

many aspects of biology but the reason
they think it's remarkable is because we.

Are just the beginning of the same to.

Our scientific development.

Might eventually figure out what just
anything that is several steps ahead

of what we can't understand it looks like
magic for us and it's always like that.

My personal belief is
that there is nothing.

In the physical.

Universe but
their rates are organized can produce

complex systems that are wonderful and
remarkable and there is also

this says nothing about religion by
the way because there is the fundament.

Question of why is
the universe organized so

well you know it could be messing
with my daughter's room and

it looks like a mess and
entropy state is much more likely and also

you can imagine a state that has different
laws of physics in different places and.

Obviously physics the instant.

The laws of physics were they just they
would be the ones that do the work but

why do work and why do they work
everywhere the same way is.

UNKNOWN And it's remarkable and
something to wonder about so

I always find it there quite
surprising that people see sciences

as contradictory to religion I
think religious person in principle

can find sciences one way
to appreciate the and

the the missing things that
nature it gives us and

it's just more that you know it's
as if you look at their life or

look at the surface it looks
like a story but then.

Open a copy learn about it
you appreciate it more and

then I don't see why there should be any
conflict because the set of questions

that are addressed by science
are quite different so

consciousness I would think that there
is something in principle reproduce

at some point once we understand
better how the brain works.

It's one of these things in nature that in
principle in the distant future we would

get that's that's my hope but
you know it's also possible.

To get hooked to devices so
people you know you see

are constantly hooked on so far more then.

You might ask what would happen in
the distant future if you extrapolate.

And.

Because people will be just.

What will be done by computers or machines
and just be hooked devices and have

virtual reality in front of them that will
be it that's the experience of living a.

Bad Thing if it happens.

Well appears in some
science fiction movies.

So my question is you said that it's
going to take about twenty five years for

that project to appear
is that a lot of it for

the time for the building of
the project itself the construction.

Whether that's a.

Good assessment for
how long it would take if you.

Were to work in the movie
seems to be promising and

then we can build the prototype and
then if.

You know it's quite possible
it would take much longer but.

To make the first steps
in that direction so

that your generation of future generations
will be able to benefit from it

because if you've never taken steps
to direction of this is a thing.

We are stuck on this planet.

Like you know the conditions with
either because of actions or

because of some nearby astronomical
events or and that's really been.

So we should contemplate the possibility
of Fame visiting other places and

figuring out how to transfer.

Civilization at some point
in the distant future.

And doesn't seem to work through a step or

humans on a spacecraft it can go
through a step where you send three D.

printers to a place that would record
the human D.N.A. then that's the trip.

And then it's a good boy.

You know if you drop it at the fifth of
a speed a friend for twenty years just

being a spacecraft you know it's
I don't I don't do that for me.

I'm sorry but I have a follow up question
and you said you're going to said Is it.

Is it just what satellite or
spacecraft spacecraft is this war is this.

The principle one can send so
it will be to the spacecraft so very cheap

you know it's roughly the cost of a cell
phone and so most of investments.

Most of the financial investment is in
the infrastructure which is we hope.

One of the big science projects like.

The James Webb Space Telescope before but
then billion.

But that assumes that the cost of laser.

Go down as you need them and.

So the hope is.

To have lots of space crafts launched
during the lifetime of this.

Project one of the challenges is of course

related to policy because it will
be an international project and

countries need to be given assurances
that this cannot be used for.

Any other purposes than
launching spacecraft and

you can imagine countries worrying about.

This being used as a weapon.

Thank you for giving such a clear and
enjoyable lecture I had a type of

a hypothetical question if say so
many years in the future we fail to

find life as we know it where
might scientists begin to look for

life less likely you know in other words
where are where might we redefine our

definition of life itself Well that's an
excellent question and there is actually.

So what we can do experiments for

example different fruits out
of the water you can try.

And check if there is a possibility for
life in the money.

As a proof that mediates.

Reactions.

You can still continue with we thought to.

Try to produce they were sent there for
life forms.

And some people are trying to pursue that
goal of producing life in the laboratory

right now there is just.

The hope of the Nobel
laureate that is working.

And that's one way to move forward and

then once you develop you can do you know
what to expect in space so it's not the.

Shot in the dark you can actually
create something that then you know for

it's quite natural for us to look for

things to us at first because
that's what we witness around us

I think you guys did you had a time limit
when we had to stop here so let us spend.