All language subtitles for Cosmos S01E11 The Immortals (1080p x265 10bit)

Must we die?

Are there beings in the cosmos
who live forever...

afloat on an endless journey

down the river of time?

"The Immortals"

Our ancestors
marked the passage of time

by the Moon and stars.

But it was the people
who once lived here,

around 5,000 years ago,

who first starting
chopping up time

into smaller bite-sized portions
of hours and minutes.

They call this place Uruk.

We call it Iraq.

It's a part of Mesopotamia,

the land between the Tigris
and the Euphrates rivers.

The city was invented here.

And one of humanity's
greatest victories was won

in the ceaseless battle
against time.

It was here that we learned
how to write.

Death could
no longer silence us.

And writing gave us the power

to reach across the millennia

and speak inside the heads
of the living.

No one has ever spoken

across a longer stretch
of time's river

than this Akkadian princess,

daughter of the first emperor
in history,

and priestess of the Moon--
Enheduanna.

For not only
did she write poetry,

but Enheduanna did something

no one before her
had ever done--

she signed her name
to her work.

She's the first person
for whom we can say

we know who she was,

and what she dreamed.

She dreamt of stepping
through the Gate of Wonder.

Here's a thought
Enheduanna sent

across more than 4,000 years
to you.

It's from her work entitled

Lady of the Largest Heart.

Innana, the planet Venus,

goddess of love,
will have a great destiny

throughout the entire universe.

...throughout
the entire universe.

And Uruk is also the place
where the epic tale

of "The Hero's Journey"
was first written down.

Before Batman, Luke Skywalker,

Odysseus-- before them all--

there was a man named Gilgamesh

who left home on a quest
to vanquish time.

Gilgamesh was searching
for immortality.

He looked everywhere,

gained complete wisdom,

uncovered what was hidden.

He brought back a tale of times
before the Great Flood.

He built the Wall of Uruk,

which no future king
will ever match.

Read the story
of that man Gilgamesh,

a hero born of Uruk,

who went through all kinds
of sufferings.

Who crossed the ocean,

the broad seas,
as far as the sunrise;

who inspected
the edges of the world,

searching for eternal life.

On his travels,

Gilgamesh encountered
a wise man named Utnapishtim,

who told him the story of a
flood that destroyed the world,

and how one of the gods
instructed Utnapishtim

to build an ark to rescue
his family and the animals.

The earliest surviving account
of the flood legend

was written down in Mesopotamia,

a thousand years
before it was retold

as the story of Noah
in the Old Testament.

So, you could say Gilgamesh

fulfilled his quest
for immortality.

We still read
the Epic of Gilgamesh,

and with every reader,
he lives again.

And all those heroes and
superheroes who have come since

follow in the footsteps
of the first hero's journey--

another kind of immortality;

a story sent from one
civilization to another

across thousands of years.

But life itself sends
its own stories

across billions of years.

It's a message that every
one of us carries inside,

inscribed in all the cells
of our bodies,

in a language that all life
on Earth can read.

The genetic code
is written in an alphabet

consisting of only four letters.

Each letter is
a molecule made of atoms;

each word is three letters long.

Every living thing is
a masterpiece,

written by nature
and edited by evolution;

the instructions
for running and reproducing

the intricate machinery of life.

The essential message of life

has been copied and recopied
for more than 3 billion years.

But where did
that message come from?

Nobody knows.

Perhaps it began in a shallow,
sunlit pool, just like this.

Somehow, carbon-rich molecules

began using energy to make
crude copies of themselves.

Some varieties were
better at making copies,

and left more offspring.

The competing molecules
became more elaborate.

Evolution and life itself
was underway.

Or life could've started

in the searing heat
of a volcanic vent

on the deep sea floor.

Or is it possible
that life came to Earth

as a hitchhiker?

Let me tell you a story

about a traveler
from another world.

The peace of the Egyptian
village of Nakhla,

near Alexandria,

was abruptly shattered
on a June morning in 1911.

Written in this meteorite was

a message from another planet.

But 70 years would pass

before anyone could read it.

In 1976,

NASA landed two Viking
spacecraft on Mars.

Carl Sagan took us there

on our original journey
through the cosmos.

We found that the Martian air

was less than one percent
as dense as ours,

and made mostly
of carbon dioxide.

There were smaller amounts
of nitrogen,

argon, water vapor and oxygen.

A few years later,

when scientists thought
to analyze the gasses

trapped inside
the Nakhla meteorite,

and other members of its class,

they found
a striking similarity--

the vast majority of meteorites

are fragments of asteroids.

But the kind
that hit Nakhla, on Earth,

could only have come
from one place...

Mars.

Welcome to Mars.

Over a billion years ago,
a volcano erupted here

and its lava cooled
into solid rock.

Hundreds of millions
of years later,

this area was flooded
with water.

And long after that flood,

an asteroid the size of
the Rock of Gibraltar

crashed into
the Martian surface,

blasting out a huge crater.

Much of the debris was ejected
back out into space,

where it orbited the Sun
until a gravitational tug

from its home planet, Mars,
diverted one of the boulders

into a collision course
with Earth.

Its arrival shook up
the little village of Nakhla.

Meteorites of the type that
hit Nakhla

are the vehicles of a natural
interplanetary transit system

that sends rocks between
the planets.

Such a meteorite can safely
shelter microscopic cargo--

the seeds of life--

an interplanetary ark.

Most rocks are porous, full of
tiny nooks and crannies,

where life can stow away.

We know
that some microbes can survive

the hostile environment
of space.

Take these guys, for instance.

These microbes spent a year
and a half riding

on the outside of the
International Space Station,

exposed to the extreme
temperatures, vacuum,

and radiation of space.

And some of them
were still alive and kicking

when they were brought back
to Earth.

Even more astonishing
are these creatures,

awakened from a deathlike sleep
of eight million years.

They were frozen
in the Antarctic ice

millions of years before
our species even existed.

And they're still alive.

If life can withstand
the hardships of space

and endure for millennia,

then it could ride the natural
interplanetary transit system

from world to world.

It's a good bet
that our microbial ancestors

spent some time in space.

Why do we think so?

The Earth is four-and-a-half-
billion-years old.

For the first half
of its lifetime,

large asteroids were bombarding
the planet

every few million years.

The most violent impacts
vaporized the oceans

and even melted
the surface rock.

Each such collision would have

completely sterilized
the planet

for thousands of years.

But we know from fossils
in the rocks

that bacteria were evolving
on Earth

during this formative period.

So how could life have survived
such a lethal series of blows?

Whenever one
of those big asteroids

hit the Earth, the explosion
would blast out a crater,

launching millions of boulders
into space.

Many of those rocks carried
living bacteria inside.

Some of the bugs would have
survived in space,

while all those left behind
on Earth would have been fried.

A few thousand years
after each impact,

the Earth would have
cooled down enough

for water to condense
into oceans.

The planet would again be
habitable.

Meanwhile, most of the rocks
launched into space

would have been orbiting
the Sun.

Some of them would encounter
the Earth again,

reenter the atmosphere
as meteorites,

and deliver their precious
cargo of life

to re-seed the planet...

like Noah's ark.

What this means is that life
doesn't have

to start over again from
scratch after each catastrophe.

It can pick up
where it left off.

When the solar system was young,

Venus was probably more
like Earth,

with oceans and maybe even life.

Venus, Earth, and Mars
were all exchanging rocks

with each other,
due to asteroid impacts.

Does life on Earth carry
any traces

of interplanetary voyages
made in the distant past?

Why is it
that some microbes can survive

the intense radiation
and vacuum of space?

These conditions don't naturally
exist on Earth.

Maybe those bugs are telling us

that their ancestors survived
those same conditions in space,

a few billion years ago.

So we know that microbes
can stow away in rocks

and survive the voyage
from planet to planet.

But what about trip
from star to star--

an interstellar odyssey?

The dandelion.

Around 30 million years ago,

it evolved another way to send
its own message of life

through space and time.

Each seedling
is a little paratrooper,

floating on the wind,

risking everything
for a safe place to land.

Updrafts can carry them
higher into the air.

A dandelion can travel dozens,

possibly hundreds
of kilometers,

even crossing over
mountain ranges.

Evolution has shaped it into
an exquisite flying machine.

The seed is another kind or ark,

ensuring the survival
of its species

by riding the currents of the
atmosphere to safe harbors.

Each seed
in its DNA carries a story,

the character and destiny
of the next dandelion--

life propagates
by retelling its story.

Is it possible that life
could survive the journey

from star to star?

The stars are about
a million times farther apart

from each other
than are the planets.

Space is so vast that it would
take billions of years

for a rock ejected
from the Earth

to collide with a planet
circling another star.

Any stowaway microbes
would never survive

the cosmic radiation
for that long.

But there's a plausible scenario

for how life could spread from
one solar system to another.

The stars of the Milky Way
are drawn by gravity

in their own enormous orbits
around its center.

Our Sun, for example,

takes some 225 million years
to complete a single orbit.

During each revolution around
the galaxy,

our solar system will
pass through two or three

gigantic interstellar clouds,

each of them
many light years across.

Galaxies are
world-making machines.

Our Milky Way has more than
100 of these vast clouds,

a place where gas and dust
condense

to form new stars and planets.

In its travels
through the Milky Way,

our Sun is accompanied not only
by its planets,

but also by
a trillion distant comets.

When our solar system passes
through an interstellar cloud,

the gravity of
the massive cloud

stirs up the outermost comets.

Some comets will be hurled out

into the space
between the stars.

Others will plunge inward...

falling towards the Sun.

And some of them may collide
with the planets.

The high-speed impact
of a comet with a rocky planet

will launch boulders
like rockets into space.

If that planet should
happen to be inhabited,

many of those rocks
will carry passengers--

living microbes.

After thousands of years,

fragments of the rocks
ejected from Earth

can fall as meteors into the
atmospheres of newborn planets

in the interstellar cloud.

If the stowaway microbes

should happen to come
in contact with liquid water,

they can revive and reproduce.

This may be
how life comes barreling

into the barren places.

The sun emerges from the cloud,

having scattered
the seeds of life

among the newborn worlds
of other stars.

Those new worlds,
now touched by life,

will then leave
their birth cloud

and go their separate ways.

Eventually, their stars
will carry them

through
other interstellar clouds,

where they may seed
still more new worlds.

Imagine this process
repeated from world to world,

each one bringing life
to others.

Life would then propagate,
like a slow chain reaction,

through the entire galaxy.

This could be
how life came to Earth.

We do not know for sure.

Are there any beings
out there like us?

Do they ask the same questions?

Do they share our fears?

Do they have heroes
and adventures?

If they do exist,
where are they?

How might they make
their presence known?

How did we first announce
our presence to the galaxy?

It was 1946, the year after
the Second World War ended.

The vivid imaginations

of HG Wells and Buck Rogers

never cooked up a more
fantastic experience

than the Army engineers

at their laboratory
in Belmar, New Jersey.

It opens up
unlimited possibilities

for interstellar experiment.

American engineers

bounced a beam
of radio waves off the Moon,

and were able
to detect its echo.

They called this experiment
Project Diana.

It was the first
interstellar message

ever sent by our species...

an eerie, tolling bell.

If one allows
the imagination free reign,

many future
possibilities appear.

Spaceships, carrying passengers

at thousands of miles per hour,

can be controlled

and communication established

with their passengers,

for we now know that
the Earth's atmosphere

can be penetrated.

Traveling at
the speed of light,

it takes just over one second

for a radio wave
to reach the lunar surface.

But the expanding wavefront
is much bigger than the Moon.

Most of the wave
passes right by it,

but the central part
gets bounced back.

After a round-trip travel time
of two and a half seconds,

it hits our planet.

Project Diana transmitted

a series of powerful
radio waves--

one every four seconds--

to "ping" the Moon.

The parts that missed the Moon
are traveling still.

It was just the beginning.

After World War II,

television stations cropped up
all over the United States,

and other parts of the world.

The Project Diana message

and the FM radio, television
and radar signals

of the 20th century

all move outward
at the speed of light.

These transmissions make up
a vast sphere of radio waves,

expanding away from the Earth
in all directions.

You could say that our world

is radiating stories.

Our ancestors etched
the story of Gilgamesh

into clay tablets,

sending that epic tale
into the future.

We've encoded our stories
in radio waves

and beamed them into space.

They cover one light-year
of distance--

that's six trillion miles--

for every year of time
since they were sent.

We've been sending
our stories into space

for over 70 years.

The leading edge
of these signals

has already washed over

thousands of planets
of other stars.

If any of these worlds are home

to a civilization
with radio telescopes,

they could already know
that we're here.

What if other worlds
are sending

their stories into space?

Since 1960,
we've been listening

for extraterrestrial
radio signals

without hearing so much
as a tolling bell.

But our search
has been sporadic

and limited to
certain parts of the sky.

For all we know,

we may have just missed
an alien signal,

looking in the wrong place

at the wrong time.

We've only listened to
a miniscule fraction

of the stars in our galaxy.

And there may be
another problem...

we are, to some extent,

prisoners of our own
moment in time

and the limits
of our technology.

Radio and television
broadcasting

may be only
a brief passing phase

in our technological
development.

When we imagine
alien civilizations

broadcasting signals
with radio telescopes,

are we any different
from earlier generations

who imagined riding
cannon shells to the Moon?

Civilizations even slightly
more advanced than ours

may have already moved on

to some other mode
of communication,

one that we have
yet to discover

or even imagine.

Their messages could be

swirling around us,
at this very moment,

but we lack the means
to perceive them,

just as all of our ancestors,

up to a little more
than a century ago,

would have been oblivious to
the most urgent radio signal

from another world.

But there's another,
more troubling possibility--

civilizations,
like other living things,

may only live so long
before perishing

due to natural causes,
or violence,

or self-inflicted wounds.

Whether or not
we ever make contact

with intelligent alien life

may depend on
a critical question.

What is the life expectancy
of a civilization?

By the time of Enheduanna,

the first person
to ever get a writing credit,

civilization was already
more than 1,000 years old.

But today, her glorious city
is a barren wasteland.

What went wrong?

One problem was
the almost ceaseless warfare

between the cities
of Mesopotamia,

which continually destroyed
their achievements.

They glorified military conquest

and ultimately
became its victims.

Another cause of decline

was that their
technical know-how

overran their
understanding of nature.

The ingenious irrigation system
that was the basis

for the great civilizations
of Mesopotamia

had an unintended consequence--

the water channeled into
their farmlands every year

evaporated and left
its salt behind.

Over generations,
the salt accumulated

and began to kill the crops.

And then, about 2,200 BC,

not long after
the time of Enheduanna,

disaster struck...

a drought of truly
epic proportions,

lasting for many decades.

The rains stopped,
crops withered,

and there was famine
and anarchy.

Barbarians invaded.

The streets of many cities
were littered with dead.

There could be only
one explanation.

Enlil, the supreme god,

was angry because
one of his temples

had been destroyed.

The people of Mesopotamia
could not know

that the same drought
was crushing

the dawning civilizations
of Egypt,

Greece, India,

Pakistan and China.

All the gods of the Earth

must have been really angry
about something.

For all their brilliance,

the people of
those civilizations

had no inkling
they were experiencing

abrupt climate change.

3,000 years later, the climate

would change abruptly for
another glorious civilization,

this one in Central America.

At its peak,

the Mayan civilization
perished,

wiped out by a series
of severe droughts

over the course of a century.

We still carry within us

the echoes of these
extinct civilizations

in our languages and our myths.

Today, we have a single
global civilization.

How long will it live?

There are so many ways
for a civilization to die.

Let's start with the ones

that we probably wouldn't
be able to do much about.

That supernova
is 1,000 light-years away.

If it were much closer, say...

less than 30 light-years
from Earth,

its cosmic radiation
would shred

the atmosphere's
protective ozone layer

and destroy our civilization.

Lucky for us, none of the stars
close enough to harm us

are likely to go supernova

any time in the next
few hundred million years.

Every million years or so,

a supervolcano erupts
somewhere on Earth.

The last time it happened
was 74,000 years ago,

on the island of Sumatra,

in what is now Indonesia.

It spewed
hundreds of times more

rock, ash and toxic gas

than any single volcano
in recorded history.

The molten rock that erupted
from Earth's crust

left this caldera,

100 kilometers long,

now filled with a lake.

The Toba volcano sent
more than 600 cubic miles

of pulverized rock
soaring skyward.

The westward wind carried the
volcanic ash over India,

where it fell out
in a smothering blanket

over the subcontinent.

The eruption loaded
the upper atmosphere

with sulfur gases.

The result was a global haze

that blocked most
of the sunlight

from reaching the surface
for at least five years.

It was like one
five-year-long cloudy day.

This so-called
"volcanic winter"

resembled a "nuclear winter,"
but without the radiation.

Temperatures fell everywhere.

Plants and animals froze
even in the tropics,

dying in enormous numbers.

But life is hardy.

Only a few species
were driven to extinction.

One of our ancestors
in central India

sharpened this stone blade

in the years before
the Toba eruption.

And this blade

was one of dozens
that were found

in the soil layer
above the volcanic fallout.

This tells us that
some toolmakers,

even in the area directly
affected by the volcano,

managed to survive
the cataclysm.

But the global human population

must have plummeted
before rebounding.

If an eruption like this
were to happen tomorrow,

our civilization
would be brought to its knees,

although the human species
would survive.

I can imagine that
our technology

of a few hundred years from now

would allow us to siphon off

the energy of
a threatening supervolcano

before it explodes.

We could then use that energy
for our own purposes.

About once every million years,
a small asteroid

collides with the Earth,

causing a similar amount
of devastation.

With our current science
and technology,

we already know how to prevent
an asteroid impact.

We would see it coming
years in advance

and could send
a spacecraft there

to deflect it into
a harmless orbit.

With the technology
of a thousand years from now,

we might even be able
to mitigate the deadly effects

of a nearby supernova
on Earth's atmosphere.

But what happens

when the danger
to a civilization is invisible?

When no one can see it coming?

Beginning with Columbus,

the European invaders
of the Americas

had a secret weapon that even
they knew nothing about.

They were carrying
bacteria and viruses

for deadly diseases,
such as smallpox,

that the original Americans
had never been exposed to.

The Europeans like to believe

that it was their valor
and superior weapons

and culture
that won them the New World.

The real conquistadors were

the armies of the pathogens
that raced on ahead

to infect and kill nine out
of ten of all the Indians

of North, Central
and South America.

The great civilizations
of the New World

crumbled under the onslaught
of invading microbes.

Without his invisible army,

Cortez and those who followed

might never
have stood a chance.

But what about civilizations
that self-destruct?

Our economic systems were
formed when the planet

and its air, rivers,
oceans, lands,

all seemed infinite.

They evolved long before
we first saw the Earth

as the tiny organism
that it actually is.

They're all alike
in one respect...

they're profit-driven,

and therefore,
focused on short-term gain.

The prevailing
economic systems,

no matter what
their ideologies,

have no built-in mechanisms

for protecting our descendants

of even 100 years from now,

let alone, 100,000.

In one respect, we're ahead

of the people
of Ancient Mesopotamia.

Unlike them, we understand
what's happening to our world.

For example,
we're pumping greenhouse gasses

into our atmosphere
at a rate not seen on Earth

for a million years.

And the scientific consensus

that we're destabilizing
our climate.

Yet our civilization seems
to be in the grip of denial;

a kind of paralysis.

There's a disconnect
between what we know

and what we do.

Being able to adapt
our behavior to challenges

is as good a definition
of intelligence as any I know.

If our greater intelligence
is the hallmark of our species,

then we should use it,

as all other beings use their
distinctive advantages--

to help ensure
that their offspring prosper,

and their heredity
is passed on,

and that the fabric of nature
that sustains us is protected.

Human intelligence
is imperfect, surely,

and newly arisen.

The ease with which it can be
sweet-talked, overwhelmed,

or subverted by other
hard-wired tendencies,

sometimes themselves disguised
as the light of reason,

is worrisome.

But if our intelligence
is the only edge,

we must learn to use it better.

To sharpen it.

To understand its limitations
and deficiencies.

To use it as cats use stealth
before pouncing.

As walking sticks
use camouflage.

To make it the tool
of our survival.

If we do this, we can solve

almost any problem
we are likely to confront

in the next 100,000 years.

And now we've arrived
at the place

where our ancient dreams
of immortality

and modern astrophysics
converge.

Giant elliptical galaxies

are something like... Florida,

where the oldest stars
in the universe may be found.

This is a red dwarf star,

smaller and fainter
than our Sun.

Red dwarfs are by far the most
plentiful stars in the cosmos.

Unlike the Sun, which is
halfway through

its 10-billion-year lifetime,

red dwarfs will continue
to provide light and warmth

to their planets
for trillions of years.

That's hundreds of times longer

than the present age
of the universe.

What would
intelligent beings do

if they had an eternity

to develop their understanding
of the universe?

Perhaps they would learn
how to open shortcuts

in the fabric of spacetime,

to travel between galaxies

faster than the speed of light.

Maybe they would create
whole new universes

as artistic
or scientific experiments.

Of course no one,
or at least nobody on Earth,

knows what
the immortals might do.

If one allows
the imagination free reign.

But what about us?

What is our own future?

What would the Cosmic Calendar

of the next 14 billion years
look like?

If the original Cosmic Calendar

includes all of time
from the birth of the universe

until this very moment...

what would
the Cosmic Calendar look like

for the next 14 billion years?

Just as with
the Cosmic Calendar of the past,

every month the future calendar

equals about a billion years;

every day, some 40 million.

Science makes it possible
for us to foretell

certain astronomical events

in the unimaginably
distant future--

the death of the Sun,
for example.

In some five billion years,

our star will have
exhausted its hydrogen--

the nuclear fuel
that powers it--

becoming a red giant.

I know that sounds depressing,

but if we apply our
intelligence, our descendants

of that distant future
will have long departed

from the lost worlds
of the Sun.

Who knows?

Human events entail
too many variables,

too many uncertainties,

to make scientific statements
about our future.

But we can still dream.

The next golden age
of human achievement

begins here and now--

New Year's Day
of the next cosmic year.

In the first tenth of a second,

we take the vision
of the pale blue dot to heart,

and learn how to share this
tiny world with each other.

The last
internal combustion engine

is placed in a museum,

as the effects of climate change
reverse and diminish.

A fifth of a second
into this future

people will stop dying
from the effects of poverty.

The planet is now
a completely self-sustaining,

intercommunicating organism.

A half-second from now,

the polar ice caps are restored

to the way they were
in the 19th century,

and the forecast
is mild and pleasant

for the next cosmic
minute and a half--

40,000 years.

By the time
we are ready to settle

even the nearest
other planetary systems,

we will have changed.

The simple passage
of so many generations

will have changed us.

Necessity will have changed us.

We are an adaptable species.

It will not be we
who reach Alpha Centauri

and the other
nearby star systems

on our interstellar arks.

It will be a species
very like us,

but with more of our strengths
and fewer of our weaknesses;

more confident, far-seeing,

capable and wise.

For all our failings,

despite our flaws
and limitations,

we humans are capable
of greatness.

What new wonders,
undreamt of in our time,

will we have accomplished
in another generation...

and another?

How far will
our nomadic species

have wandered
by the end of the next century,

and the next millennium?

Our remote descendants,

safely arrayed on many worlds

throughout the solar system
and beyond,

will be unified
by their common heritage,

by their regard
for their home planet,

and by their knowledge that,
whatever other life may be,

the only humans
in all the universe

came from Earth.

They will gaze up
and strain to find

the blue dot in their skies.

They will marvel
at how vulnerable

the repository of all
our potential once was,

how perilous our infancy,

how humble our beginnings,

how many rivers
we had to cross...

before we found our way.