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NEIL DEGRASSE TYSON:
Must we die?
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Are there beings in the cosmos
who live forever...
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...afloat on an endless journey
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down the river of time?
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¶ ¶
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¶ ¶
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¶ ¶
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DEGRASSE TYSON: Our ancestors
marked the passage of time
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by the Moon and stars.
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But it was the people
who once lived here,
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around 5,000 years ago,
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who first starting
chopping up time
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into smaller bite-sized portions
of hours and minutes.
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They call this place Uruk.
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We call it Iraq.
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It's a part of Mesopotamia,
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the land between the Tigris
and the Euphrates rivers.
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The city was invented here.
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And one of humanity's
greatest victories was won
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in the ceaseless battle
against time.
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It was here that we learned
how to write.
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Death could
no longer silence us.
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And writing gave us the power
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to reach across the millennia
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and speak inside the heads
of the living.
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No one has ever spoken
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across a longer stretch
of time's river
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than this Akkadian princess,
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daughter of the first emperor
in history,
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and priestess of the Moon--
Enheduanna.
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For not only
did she write poetry,
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but Enheduanna did something
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no one before her
had ever done--
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she signed her name
to her work.
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She's the first person
for whom we can say
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we know who she was,
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and what she dreamed.
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She dreamt of stepping
through the Gate of Wonder.
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Here's a thought
Enheduanna sent
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across more than 4,000 years
to you.
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It's from her work entitled
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Lady of the Largest Heart.
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(Enheduanna speaking Sumerian)
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ENHEDUANNA (translated):
Innana, the planet Venus,
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goddess of love,
will have a great destiny
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throughout the entire universe.
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(echoing): ...throughout
the entire universe.
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And Uruk is also the place
where the epic tale
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of "The Hero's Journey"
was first written down.
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Before Batman, Luke Skywalker,
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Odysseus-- before them all--
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there was a man named Gilgamesh
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who left home on a quest
to vanquish time.
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Gilgamesh was searching
for immortality.
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He looked everywhere,
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gained complete wisdom,
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uncovered what was hidden.
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He brought back a tale of times
before the Great Flood.
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(creature growling)
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He built the Wall of Uruk,
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which no future king
will ever match.
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Read the story
of that man Gilgamesh,
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a hero born of Uruk,
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who went through all kinds
of sufferings.
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Who crossed the ocean,
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the broad seas,
as far as the sunrise;
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who inspected
the edges of the world,
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searching for eternal life.
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On his travels,
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Gilgamesh encountered
a wise man named Utnapishtim,
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who told him the story of a
flood that destroyed the world,
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and how one of the gods
instructed Utnapishtim
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to build an ark to rescue
his family and the animals.
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(thunder crashing)
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(dove cooing)
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The earliest surviving account
of the flood legend
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was written down in Mesopotamia,
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a thousand years
before it was retold
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as the story of Noah
in the Old Testament.
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So, you could say Gilgamesh
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fulfilled his quest
for immortality.
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We still read
the Epic of Gilgamesh,
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and with every reader,
he lives again.
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And all those heroes and
superheroes who have come since
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follow in the footsteps
of the first hero's journey--
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another kind of immortality;
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a story sent from one
civilization to another
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across thousands of years.
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But life itself sends
its own stories
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across billions of years.
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It's a message that every
one of us carries inside,
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inscribed in all the cells
of our bodies,
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in a language that all life
on Earth can read.
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The genetic code
is written in an alphabet
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consisting of only four letters.
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Each letter is
a molecule made of atoms;
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each word is three letters long.
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Every living thing is
a masterpiece,
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written by nature
and edited by evolution;
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the instructions
for running and reproducing
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the intricate machinery of life.
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The essential message of life
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has been copied and recopied
for more than 3 billion years.
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But where did
that message come from?
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Nobody knows.
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Perhaps it began in a shallow,
sunlit pool, just like this.
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Somehow, carbon-rich molecules
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began using energy to make
crude copies of themselves.
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Some varieties were
better at making copies,
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and left more offspring.
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The competing molecules
became more elaborate.
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Evolution and life itself
was underway.
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Or life could've started
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in the searing heat
of a volcanic vent
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on the deep sea floor.
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Or is it possible
that life came to Earth
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as a hitchhiker?
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Let me tell you a story
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about a traveler
from another world.
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The peace of the Egyptian
village of Nakhla,
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near Alexandria,
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was abruptly shattered
on a June morning in 1911.
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Written in this meteorite was
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a message from another planet.
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But 70 years would pass
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before anyone could read it.
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In 1976,
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NASA landed two Viking
spacecraft on Mars.
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Carl Sagan took us there
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on our original journey
through the cosmos.
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CARL SAGAN:
We found that the Martian air
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was less than one percent
as dense as ours,
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and made mostly
of carbon dioxide.
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There were smaller amounts
of nitrogen,
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argon, water vapor and oxygen.
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DEGRASSE TYSON:
A few years later,
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when scientists thought
to analyze the gasses
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trapped inside
the Nakhla meteorite,
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and other members of its class,
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they found
a striking similarity--
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the vast majority of meteorites
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are fragments of asteroids.
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But the kind
that hit Nakhla, on Earth,
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could only have come
from one place...
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Mars.
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Welcome to Mars.
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Over a billion years ago,
a volcano erupted here
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and its lava cooled
into solid rock.
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Hundreds of millions
of years later,
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this area was flooded
with water.
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And long after that flood,
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an asteroid the size of
the Rock of Gibraltar
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crashed into
the Martian surface,
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blasting out a huge crater.
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Much of the debris was ejected
back out into space,
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where it orbited the Sun
until a gravitational tug
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from its home planet, Mars,
diverted one of the boulders
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into a collision course
with Earth.
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Its arrival shook up
the little village of Nakhla.
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Meteorites of the type that
hit Nakhla
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are the vehicles of a natural
interplanetary transit system
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that sends rocks between
the planets.
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Such a meteorite can safely
shelter microscopic cargo--
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the seeds of life--
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an interplanetary ark.
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Most rocks are porous, full of
tiny nooks and crannies,
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where life can stow away.
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We know
that some microbes can survive
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the hostile environment
of space.
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Take these guys, for instance.
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These microbes spent a year
and a half riding
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on the outside of the
International Space Station,
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exposed to the extreme
temperatures, vacuum,
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and radiation of space.
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And some of them
were still alive and kicking
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when they were brought back
to Earth.
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Even more astonishing
are these creatures,
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awakened from a deathlike sleep
of eight million years.
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They were frozen
in the Antarctic ice
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millions of years before
our species even existed.
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And they're still alive.
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If life can withstand
the hardships of space
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and endure for millennia,
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then it could ride the natural
interplanetary transit system
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from world to world.
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It's a good bet
that our microbial ancestors
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spent some time in space.
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Why do we think so?
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The Earth is four-and-a-half-
billion-years old.
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For the first half
of its lifetime,
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large asteroids were bombarding
the planet
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every few million years.
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The most violent impacts
vaporized the oceans
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and even melted
the surface rock.
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Each such collision would have
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completely sterilized
the planet
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for thousands of years.
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But we know from fossils
in the rocks
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that bacteria were evolving
on Earth
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during this formative period.
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So how could life have survived
such a lethal series of blows?
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Whenever one
of those big asteroids
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hit the Earth, the explosion
would blast out a crater,
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launching millions of boulders
into space.
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Many of those rocks carried
living bacteria inside.
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Some of the bugs would have
survived in space,
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while all those left behind
on Earth would have been fried.
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A few thousand years
after each impact,
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00:13:21,600 --> 00:13:23,735
the Earth would have
cooled down enough
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for water to condense
into oceans.
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The planet would again be
habitable.
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Meanwhile, most of the rocks
launched into space
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would have been orbiting
the Sun.
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Some of them would encounter
the Earth again,
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00:13:40,319 --> 00:13:43,221
reenter the atmosphere
as meteorites,
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and deliver their precious
cargo of life
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00:13:45,758 --> 00:13:47,859
to re-seed the planet...
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00:13:49,962 --> 00:13:51,996
...like Noah's ark.
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00:13:52,031 --> 00:13:54,232
What this means is that life
doesn't have
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00:13:54,266 --> 00:13:58,803
to start over again from
scratch after each catastrophe.
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It can pick up
where it left off.
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00:14:02,842 --> 00:14:04,409
When the solar system was young,
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Venus was probably more
like Earth,
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00:14:06,645 --> 00:14:09,781
with oceans and maybe even life.
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00:14:09,815 --> 00:14:13,084
Venus, Earth, and Mars
were all exchanging rocks
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00:14:13,118 --> 00:14:15,019
with each other,
due to asteroid impacts.
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00:14:15,054 --> 00:14:18,189
Does life on Earth carry
any traces
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00:14:18,224 --> 00:14:20,825
of interplanetary voyages
made in the distant past?
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00:14:20,860 --> 00:14:24,195
Why is it
that some microbes can survive
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00:14:24,230 --> 00:14:27,599
the intense radiation
and vacuum of space?
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00:14:27,633 --> 00:14:30,969
These conditions don't naturally
exist on Earth.
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00:14:31,003 --> 00:14:32,871
Maybe those bugs
are telling us
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00:14:32,905 --> 00:14:37,141
that their ancestors survived
those same conditions in space,
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00:14:37,143 --> 00:14:39,244
a few billion years ago.
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00:14:40,479 --> 00:14:42,947
So we know that microbes
can stow away in rocks
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00:14:42,982 --> 00:14:45,683
and survive the voyage
from planet to planet.
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But what about trip
from star to star--
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an interstellar odyssey?
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00:14:56,178 --> 00:14:58,246
The dandelion.
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Around 30 million years ago,
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00:15:00,749 --> 00:15:04,252
it evolved another way to send
its own message of life
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00:15:04,286 --> 00:15:06,621
through space and time.
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00:15:14,363 --> 00:15:17,398
Each seedling
is a little paratrooper,
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floating on the wind,
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00:15:19,101 --> 00:15:23,104
risking everything
for a safe place to land.
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00:15:23,138 --> 00:15:27,475
Updrafts can carry them
higher into the air.
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00:15:27,509 --> 00:15:28,910
A dandelion can travel dozens,
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00:15:28,944 --> 00:15:30,979
possibly hundreds
of kilometers,
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00:15:31,013 --> 00:15:35,516
even crossing over
mountain ranges.
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00:15:35,551 --> 00:15:40,321
Evolution has shaped it into
an exquisite flying machine.
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00:15:40,356 --> 00:15:43,024
The seed is another kind or ark,
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00:15:43,058 --> 00:15:44,926
ensuring the survival
of its species
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00:15:44,960 --> 00:15:48,429
by riding the currents of the
atmosphere to safe harbors.
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00:15:48,464 --> 00:15:51,799
Each seed
in its DNA carries a story,
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00:15:51,834 --> 00:15:55,003
the character and destiny
of the next dandelion--
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00:15:55,037 --> 00:15:58,806
life propagates
by retelling its story.
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00:16:00,743 --> 00:16:04,112
Is it possible that life
could survive the journey
258
00:16:04,146 --> 00:16:06,114
from star to star?
259
00:16:06,148 --> 00:16:08,983
The stars are about
a million times farther apart
260
00:16:09,018 --> 00:16:11,552
from each other
than are the planets.
261
00:16:11,587 --> 00:16:15,490
Space is so vast that it would
take billions of years
262
00:16:15,524 --> 00:16:17,358
for a rock ejected
from the Earth
263
00:16:17,393 --> 00:16:22,130
to collide with a planet
circling another star.
264
00:16:22,164 --> 00:16:25,133
Any stowaway microbes
would never survive
265
00:16:25,167 --> 00:16:27,468
the cosmic radiation
for that long.
266
00:16:27,486 --> 00:16:29,370
But there's a plausible scenario
267
00:16:29,405 --> 00:16:33,191
for how life could spread from
one solar system to another.
268
00:16:38,947 --> 00:16:41,315
The stars of the Milky Way
are drawn by gravity
269
00:16:41,350 --> 00:16:45,553
in their own enormous orbits
around its center.
270
00:16:45,587 --> 00:16:47,422
Our Sun, for example,
271
00:16:47,523 --> 00:16:52,193
takes some 225 million years
to complete a single orbit.
272
00:16:52,227 --> 00:16:55,430
During each revolution around
the galaxy,
273
00:16:55,464 --> 00:16:58,433
our solar system will
pass through two or three
274
00:16:58,467 --> 00:17:00,868
gigantic interstellar clouds,
275
00:17:00,903 --> 00:17:04,572
each of them
many light years across.
276
00:17:08,110 --> 00:17:12,346
Galaxies are
world-making machines.
277
00:17:12,381 --> 00:17:16,050
Our Milky Way has more than
100 of these vast clouds,
278
00:17:16,052 --> 00:17:18,619
places where gas and dust
condense
279
00:17:18,654 --> 00:17:21,289
to form new stars and planets.
280
00:17:24,660 --> 00:17:26,944
In its travels
through the Milky Way,
281
00:17:26,995 --> 00:17:29,964
our Sun is accompanied not only
by its planets,
282
00:17:29,998 --> 00:17:33,501
but also by
a trillion distant comets.
283
00:17:35,471 --> 00:17:38,773
When our solar system passes
through an interstellar cloud,
284
00:17:38,807 --> 00:17:41,075
the gravity of
the massive cloud
285
00:17:41,110 --> 00:17:44,779
stirs up the outermost comets.
286
00:17:44,813 --> 00:17:47,582
Some comets will be hurled out
287
00:17:47,616 --> 00:17:50,151
into the space
between the stars.
288
00:17:52,154 --> 00:17:54,589
Others will plunge inward...
289
00:17:56,959 --> 00:17:59,460
...falling towards the Sun.
290
00:18:13,809 --> 00:18:15,409
(explosion thundering)
291
00:18:15,444 --> 00:18:18,646
And some of them may collide
with the planets.
292
00:18:20,215 --> 00:18:23,751
The high-speed impact
of a comet with a rocky planet
293
00:18:23,786 --> 00:18:27,188
will launch boulders
like rockets into space.
294
00:18:27,222 --> 00:18:30,091
If that planet should
happen to be inhabited,
295
00:18:30,125 --> 00:18:32,794
many of those rocks
will carry passengers--
296
00:18:32,828 --> 00:18:35,129
living microbes.
297
00:18:35,164 --> 00:18:37,098
After thousands of years,
298
00:18:37,132 --> 00:18:39,433
fragments of the rocks
ejected from Earth
299
00:18:39,468 --> 00:18:43,871
can fall as meteors into the
atmospheres of newborn planets
300
00:18:43,906 --> 00:18:46,140
in the interstellar cloud.
301
00:18:53,081 --> 00:18:54,649
If the stowaway microbes
302
00:18:54,683 --> 00:18:57,518
should happen to come
in contact with liquid water,
303
00:18:57,553 --> 00:19:01,122
they can revive and reproduce.
304
00:19:01,156 --> 00:19:03,791
This may be
how life comes barreling
305
00:19:03,826 --> 00:19:06,160
into the barren places.
306
00:19:06,195 --> 00:19:08,696
The sun emerges from the cloud,
307
00:19:08,730 --> 00:19:10,331
having scattered
the seeds of life
308
00:19:10,365 --> 00:19:13,951
among the newborn worlds
of other stars.
309
00:19:14,002 --> 00:19:17,038
Those new worlds,
now touched by life,
310
00:19:17,072 --> 00:19:18,639
will then leave
their birth cloud
311
00:19:18,674 --> 00:19:20,842
and go their separate ways.
312
00:19:20,876 --> 00:19:23,311
Eventually, their stars
will carry them
313
00:19:23,345 --> 00:19:24,745
through
other interstellar clouds,
314
00:19:24,780 --> 00:19:28,583
where they may seed
still more new worlds.
315
00:19:28,617 --> 00:19:34,055
Imagine this process
repeated from world to world,
316
00:19:34,089 --> 00:19:37,191
each one bringing life
to others.
317
00:19:43,265 --> 00:19:47,235
Life would then propagate,
like a slow chain reaction,
318
00:19:47,269 --> 00:19:49,604
through the entire galaxy.
319
00:19:54,209 --> 00:19:58,279
This could be
how life came to Earth.
320
00:19:58,313 --> 00:20:00,281
We do not know for sure.
321
00:20:00,315 --> 00:20:03,951
Are there any beings
out there like us?
322
00:20:03,986 --> 00:20:05,920
Do they ask the same questions?
323
00:20:05,954 --> 00:20:07,622
Do they share our fears?
324
00:20:07,656 --> 00:20:08,923
(bell tolls)
325
00:20:08,957 --> 00:20:10,591
Do they have heroes
and adventures?
326
00:20:10,626 --> 00:20:15,913
(bell tolling)
327
00:20:15,964 --> 00:20:19,800
If they do exist,
where are they?
328
00:20:19,835 --> 00:20:22,336
How might they make
their presence known?
329
00:20:38,453 --> 00:20:41,789
How did we first announce
our presence to the galaxy?
330
00:20:41,823 --> 00:20:47,495
It was 1946, the year after
the Second World War ended.
331
00:20:50,098 --> 00:20:52,099
NEWSREEL ANNOUNCER:
The vivid imaginations
332
00:20:52,134 --> 00:20:53,868
of H.G. Wells and Buck Rogers
333
00:20:53,952 --> 00:20:55,836
never cooked up a more
fantastic experience
334
00:20:55,854 --> 00:20:58,439
than the Army engineers
335
00:20:58,473 --> 00:21:00,674
at their laboratory
in Belmar, New Jersey.
336
00:21:00,676 --> 00:21:02,643
It opens up
unlimited possibilities
337
00:21:02,678 --> 00:21:04,462
for interstellar experiment.
338
00:21:04,513 --> 00:21:05,746
DEGRASSE TYSON:
American engineers
339
00:21:05,781 --> 00:21:08,349
bounced a beam
of radio waves off the Moon,
340
00:21:08,383 --> 00:21:10,584
and were able
to detect its echo.
341
00:21:10,619 --> 00:21:13,287
(electronic thrumming)
342
00:21:13,388 --> 00:21:17,325
(electronic warbling and static)
343
00:21:17,359 --> 00:21:20,361
They called this experiment
Project Diana.
344
00:21:20,395 --> 00:21:22,029
It was the first
interstellar message
345
00:21:22,064 --> 00:21:24,098
ever sent by our species...
346
00:21:24,132 --> 00:21:26,534
(bell tolling)
347
00:21:26,568 --> 00:21:28,502
...an eerie, tolling bell.
348
00:21:30,238 --> 00:21:33,975
If one allows
the imagination free reign,
349
00:21:34,009 --> 00:21:37,211
many future
possibilities appear.
350
00:21:39,247 --> 00:21:42,016
Spaceships, carrying passengers
351
00:21:42,050 --> 00:21:43,951
at thousands of miles per hour,
352
00:21:43,953 --> 00:21:45,853
can be controlled
353
00:21:45,887 --> 00:21:48,005
and communication established
354
00:21:48,056 --> 00:21:49,707
with their passengers,
355
00:21:49,758 --> 00:21:52,393
for we now know that
the Earth's atmosphere
356
00:21:52,411 --> 00:21:54,261
can be penetrated.
357
00:21:59,935 --> 00:22:02,169
DEGRASSE TYSON: Traveling at
the speed of light,
358
00:22:02,204 --> 00:22:03,470
it takes just over one second
359
00:22:03,522 --> 00:22:05,706
for a radio wave
to reach the lunar surface.
360
00:22:07,275 --> 00:22:11,178
But the expanding wavefront
is much bigger than the Moon.
361
00:22:11,213 --> 00:22:13,714
Most of the wave
passes right by it,
362
00:22:13,749 --> 00:22:16,117
but the central part
gets bounced back.
363
00:22:18,020 --> 00:22:20,988
After a round-trip travel time
of two and a half seconds,
364
00:22:21,023 --> 00:22:22,356
it hits our planet.
365
00:22:23,759 --> 00:22:25,760
Project Diana transmitted
366
00:22:25,794 --> 00:22:27,545
a series of powerful
radio waves--
367
00:22:27,596 --> 00:22:28,996
one every four seconds--
368
00:22:29,031 --> 00:22:31,165
to "ping" the Moon.
369
00:22:31,199 --> 00:22:33,401
(bell tolling)
370
00:22:33,435 --> 00:22:37,071
The parts that missed the Moon
are traveling still.
371
00:22:37,073 --> 00:22:39,757
(garbled voices, static)
372
00:22:39,808 --> 00:22:41,709
It was just the beginning.
373
00:22:41,776 --> 00:22:43,277
After World War II,
374
00:22:43,311 --> 00:22:46,380
television stations cropped up
all over the United States,
375
00:22:46,415 --> 00:22:47,715
and other parts of the world.
376
00:22:47,782 --> 00:22:49,417
(various overlapping voices
and static)
377
00:22:49,451 --> 00:22:51,252
The Project Diana message
378
00:22:51,269 --> 00:22:54,221
and the FM radio, television
and radar signals
379
00:22:54,256 --> 00:22:55,689
of the 20th century
380
00:22:55,724 --> 00:22:57,725
all move outward
at the speed of light.
381
00:22:57,759 --> 00:23:02,029
These transmissions make up
a vast sphere of radio waves,
382
00:23:02,097 --> 00:23:04,999
expanding away from the Earth
in all directions.
383
00:23:05,100 --> 00:23:07,101
You could say that our world
384
00:23:07,135 --> 00:23:10,237
is radiating stories.
385
00:23:10,272 --> 00:23:13,407
Our ancestors etched
the story of Gilgamesh
386
00:23:13,442 --> 00:23:15,242
into clay tablets,
387
00:23:15,277 --> 00:23:18,212
sending that epic tale
into the future.
388
00:23:18,246 --> 00:23:21,115
We've encoded our stories
in radio waves
389
00:23:21,117 --> 00:23:22,983
and beamed them into space.
390
00:23:23,018 --> 00:23:25,553
They cover one light-year
of distance--
391
00:23:25,587 --> 00:23:27,922
that's six trillion miles--
392
00:23:27,956 --> 00:23:30,391
for every year of time
since they were sent.
393
00:23:30,425 --> 00:23:32,893
We've been sending
our stories into space
394
00:23:32,928 --> 00:23:34,728
for over 70 years.
395
00:23:34,763 --> 00:23:36,430
The leading edge
of these signals
396
00:23:36,432 --> 00:23:38,099
has already washed over
397
00:23:38,133 --> 00:23:40,334
thousands of planets
of other stars.
398
00:23:40,435 --> 00:23:42,503
If any of these worlds are home
399
00:23:42,537 --> 00:23:45,072
to a civilization
with radio telescopes,
400
00:23:45,107 --> 00:23:48,008
they could already know
that we're here.
401
00:23:51,379 --> 00:23:53,614
What if other worlds
are sending
402
00:23:53,648 --> 00:23:55,649
their stories into space?
403
00:23:57,285 --> 00:23:59,653
Since 1960,
we've been listening
404
00:23:59,688 --> 00:24:01,789
for extraterrestrial
radio signals
405
00:24:01,856 --> 00:24:05,092
without hearing so much
as a tolling bell.
406
00:24:05,127 --> 00:24:07,795
But our search
has been sporadic
407
00:24:07,862 --> 00:24:10,030
and limited to
certain parts of the sky.
408
00:24:15,170 --> 00:24:16,637
For all we know,
409
00:24:16,671 --> 00:24:19,306
we may have just missed
an alien signal,
410
00:24:19,341 --> 00:24:20,875
looking in the wrong place
411
00:24:20,909 --> 00:24:23,043
at the wrong time.
412
00:24:23,078 --> 00:24:25,179
We've only listened to
a miniscule fraction
413
00:24:25,213 --> 00:24:26,881
of the stars in our galaxy.
414
00:24:26,915 --> 00:24:28,549
And there may be
another problem:
415
00:24:28,583 --> 00:24:30,384
we are, to some extent,
416
00:24:30,418 --> 00:24:32,353
prisoners of our own
moment in time
417
00:24:32,387 --> 00:24:34,288
and the limits
of our technology.
418
00:24:34,322 --> 00:24:36,790
Radio and television
broadcasting
419
00:24:36,825 --> 00:24:39,226
may be only
a brief passing phase
420
00:24:39,261 --> 00:24:41,879
in our technological
development.
421
00:24:41,930 --> 00:24:44,632
When we imagine
alien civilizations
422
00:24:44,666 --> 00:24:47,067
broadcasting signals
with radio telescopes,
423
00:24:47,102 --> 00:24:50,304
are we any different
from earlier generations
424
00:24:50,338 --> 00:24:53,841
who imagined riding
cannon shells to the Moon?
425
00:24:55,343 --> 00:24:58,212
Civilizations even sliy
more advanced than ours
426
00:24:58,214 --> 00:24:59,914
may have already moved on
427
00:24:59,916 --> 00:25:02,650
to some other mode
of communication,
428
00:25:02,652 --> 00:25:04,552
one that we have
yet to discover
429
00:25:04,554 --> 00:25:06,554
or even imagine.
430
00:25:06,556 --> 00:25:08,122
Their messages could be
431
00:25:08,124 --> 00:25:09,890
swirling around us,
at this very moment,
432
00:25:09,892 --> 00:25:13,561
but we lack the means
to perceive them,
433
00:25:13,563 --> 00:25:15,329
just as all of our ancestors,
434
00:25:15,331 --> 00:25:17,097
up to a little more
than a century ago,
435
00:25:17,099 --> 00:25:20,301
would have been oblivious to
the most urgent radio signal
436
00:25:20,303 --> 00:25:23,170
from another world.
437
00:25:23,172 --> 00:25:26,340
But there's another,
more troubling possibility--
438
00:25:26,342 --> 00:25:29,109
civilizations,
like other living things,
439
00:25:29,111 --> 00:25:31,845
may only live so long
before perishing
440
00:25:31,880 --> 00:25:34,114
due to natural causes,
or violence,
441
00:25:34,149 --> 00:25:36,450
or self-inflicted wounds.
442
00:25:36,484 --> 00:25:38,786
Whether or not
we ever make contact
443
00:25:38,853 --> 00:25:40,221
with intelligent alien life
444
00:25:40,238 --> 00:25:42,690
may depend on
a critical question:
445
00:25:42,757 --> 00:25:46,827
What is the life expectancy
of a civilization?
446
00:26:08,049 --> 00:26:10,517
DEGRASSE TYSON:
By the time of Enheduanna,
447
00:26:10,552 --> 00:26:12,753
the first person
to ever get a writing credit,
448
00:26:12,787 --> 00:26:15,856
civilization was already
more than 1,000 years old.
449
00:26:17,892 --> 00:26:22,196
But today, her glorious city
is a barren wasteland.
450
00:26:22,230 --> 00:26:23,631
What went wrong?
451
00:26:23,665 --> 00:26:26,000
One problem was
the almost ceaseless warfare
452
00:26:26,034 --> 00:26:28,269
between the cities
of Mesopotamia,
453
00:26:28,303 --> 00:26:30,938
which continually destroyed
their achievements.
454
00:26:30,972 --> 00:26:33,107
They glorified military conquest
455
00:26:33,141 --> 00:26:36,543
and ultimately
became its victims.
456
00:26:38,980 --> 00:26:41,015
Another cause of decline
457
00:26:41,049 --> 00:26:42,716
was that their
technical know-how
458
00:26:42,751 --> 00:26:45,185
overran their
understanding of nature.
459
00:26:45,220 --> 00:26:47,888
The ingenious irrigation system
that was the basis
460
00:26:47,922 --> 00:26:50,391
for the great civilizations
of Mesopotamia
461
00:26:50,425 --> 00:26:52,359
had an unintended consequence--
462
00:26:52,394 --> 00:26:55,729
the water channeled into
their farmlands every year
463
00:26:55,764 --> 00:26:59,366
evaporated and left
its salt behind.
464
00:26:59,401 --> 00:27:01,969
Over generations,
the salt accumulated
465
00:27:02,003 --> 00:27:03,804
and began to kill the crops.
466
00:27:03,838 --> 00:27:07,074
And then, about 2,200 BC,
467
00:27:07,108 --> 00:27:09,410
not long after
the time of Enheduanna,
468
00:27:09,444 --> 00:27:11,345
disaster struck:
469
00:27:11,379 --> 00:27:14,481
a drought of truly
epic proportions,
470
00:27:14,516 --> 00:27:16,050
lasting for many decades.
471
00:27:16,084 --> 00:27:17,985
The rains stopped,
crops withered,
472
00:27:18,019 --> 00:27:19,486
and there was famine
and anarchy.
473
00:27:19,521 --> 00:27:21,322
Barbarians invaded.
474
00:27:21,356 --> 00:27:24,992
The streets of many cities
were littered with dead.
475
00:27:25,026 --> 00:27:26,894
There could be only
one explanation:
476
00:27:26,928 --> 00:27:28,896
Enlil, the supreme god,
477
00:27:28,930 --> 00:27:31,498
was angry because
one of his temples
478
00:27:31,533 --> 00:27:33,000
had been destroyed.
479
00:27:33,034 --> 00:27:36,337
The people of Mesopotamia
could not know
480
00:27:36,371 --> 00:27:38,072
that the same drought
was crushing
481
00:27:38,106 --> 00:27:40,040
the dawning civilizations
of Egypt,
482
00:27:40,075 --> 00:27:41,675
Greece, India,
483
00:27:41,710 --> 00:27:43,377
Pakistan and China.
484
00:27:43,411 --> 00:27:45,079
All the gods of the Earth
485
00:27:45,113 --> 00:27:48,015
must have been really angry
about something.
486
00:27:48,049 --> 00:27:49,450
For all their brilliance,
487
00:27:49,484 --> 00:27:51,118
the people of
those civilizations
488
00:27:51,152 --> 00:27:53,354
had no inkling
they were experiencing
489
00:27:53,388 --> 00:27:55,589
(bird screeches)
abrupt climate change.
490
00:27:59,461 --> 00:28:01,729
3,000 years later, the climate
491
00:28:01,763 --> 00:28:04,698
would change abruptly for
another glorious civilization,
492
00:28:04,733 --> 00:28:06,800
this one in Central America.
493
00:28:06,835 --> 00:28:08,235
At its peak,
494
00:28:08,269 --> 00:28:10,404
the Mayan civilization
perished,
495
00:28:10,438 --> 00:28:12,906
wiped out by a series
of severe droughts
496
00:28:12,941 --> 00:28:14,308
over the course of a century.
497
00:28:14,342 --> 00:28:16,810
We still carry within us
498
00:28:16,845 --> 00:28:19,546
the echoes of these
extinct civilizations
499
00:28:19,581 --> 00:28:22,282
in our languages and our myths.
500
00:28:22,317 --> 00:28:26,220
Today, we have a single
global civilization.
501
00:28:26,254 --> 00:28:28,055
How long will it live?
502
00:28:28,089 --> 00:28:31,625
There are so many ways
for a civilization to die.
503
00:28:31,659 --> 00:28:33,060
Let's start with the ones
504
00:28:33,094 --> 00:28:35,095
that we probably wouldn't
be able to do much about.
505
00:28:37,332 --> 00:28:40,967
That supernova
is 1,000 light-years away.
506
00:28:40,969 --> 00:28:43,103
If it were much closer, say...
507
00:28:43,138 --> 00:28:45,606
less than 30 light-years
from Earth,
508
00:28:45,640 --> 00:28:47,908
its cosmic radiation
would shred
509
00:28:47,942 --> 00:28:49,977
the atmosphere's
protective ozone layer
510
00:28:50,011 --> 00:28:52,162
and destroy our civilization.
511
00:28:52,213 --> 00:28:55,682
Lucky for us, none of the stars
close enough to harm us
512
00:28:55,717 --> 00:28:57,451
are likely to go supernova
513
00:28:57,485 --> 00:28:59,853
any time in the next
few hundred million years.
514
00:29:05,794 --> 00:29:07,594
Every million years or so,
515
00:29:07,629 --> 00:29:11,331
a supervolcano erupts
somewhere on Earth.
516
00:29:11,366 --> 00:29:15,636
The last time it happened
was 74,000 years ago,
517
00:29:15,670 --> 00:29:17,137
on the island of Sumatra,
518
00:29:17,172 --> 00:29:20,040
in what is now Indonesia.
519
00:29:20,074 --> 00:29:21,975
It spewed
hundreds of times more
520
00:29:22,010 --> 00:29:23,944
rock, ash and toxic gas
521
00:29:23,978 --> 00:29:27,147
than any single volcano
in recorded history.
522
00:29:27,182 --> 00:29:30,551
The molten rock that erupted
from Earth's crust
523
00:29:30,585 --> 00:29:32,453
left this caldera,
524
00:29:32,487 --> 00:29:34,188
100 kilometers long,
525
00:29:34,222 --> 00:29:36,356
now filled with a lake.
526
00:29:39,327 --> 00:29:44,131
The Toba volcano sent
more than 600 cubic miles
527
00:29:44,165 --> 00:29:47,167
of pulverized rock
soaring skyward.
528
00:29:47,202 --> 00:29:51,004
The westward wind carried the
volcanic ash over India,
529
00:29:51,039 --> 00:29:53,073
where it fell out
in a smothering blanket
530
00:29:53,107 --> 00:29:55,876
over the subcontinent.
531
00:29:55,910 --> 00:29:58,479
The eruption loaded
the upper atmosphere
532
00:29:58,513 --> 00:30:00,214
with sulfur gases.
533
00:30:00,248 --> 00:30:02,182
The result was a global haze
534
00:30:02,217 --> 00:30:04,084
that blocked most
of the sunlight
535
00:30:04,118 --> 00:30:06,653
from reaching the surface
for at least five years.
536
00:30:06,688 --> 00:30:09,957
It was like one
five-year-long cloudy day.
537
00:30:11,226 --> 00:30:14,061
This so-called
"volcanic winter"
538
00:30:14,095 --> 00:30:18,098
resembled a "nuclear winter,"
but without the radiation.
539
00:30:19,133 --> 00:30:21,568
Temperatures fell everywhere.
540
00:30:21,603 --> 00:30:24,204
Plants and animals froze
even in the tropics,
541
00:30:24,239 --> 00:30:26,106
dying in enormous numbers.
542
00:30:26,140 --> 00:30:27,608
But life is hardy.
543
00:30:27,642 --> 00:30:30,677
Only a few species
were driven to extinction.
544
00:30:30,712 --> 00:30:33,247
One of our ancestors
in central India
545
00:30:33,281 --> 00:30:34,681
sharpened this stone blade
546
00:30:34,716 --> 00:30:37,067
in the years before
the Toba eruption.
547
00:30:37,118 --> 00:30:39,253
And this blade
548
00:30:39,287 --> 00:30:40,854
was one of dozens
that were found
549
00:30:40,889 --> 00:30:43,524
in the soil layer
above the volcanic fallout.
550
00:30:43,558 --> 00:30:46,026
This tells us that
some toolmakers,
551
00:30:46,060 --> 00:30:48,562
even in the area directly
affected by the volcano,
552
00:30:48,596 --> 00:30:50,697
managed to survive
the cataclysm.
553
00:30:50,732 --> 00:30:53,267
But the global human population
554
00:30:53,301 --> 00:30:55,569
must have plummeted
before rebounding.
555
00:30:55,603 --> 00:30:58,572
If an eruption like this
were to happen tomorrow,
556
00:30:58,606 --> 00:31:01,375
our civilization
would be brought to its knees,
557
00:31:01,409 --> 00:31:04,645
although the human species
would survive.
558
00:31:06,915 --> 00:31:09,049
I can imagine that
our technology
559
00:31:09,083 --> 00:31:10,751
of a few hundred years from now
560
00:31:10,785 --> 00:31:12,252
would allow us to siphon off
561
00:31:12,287 --> 00:31:14,288
the energy of
a threatening supervolcano
562
00:31:14,322 --> 00:31:16,123
before it explodes.
563
00:31:16,157 --> 00:31:18,625
We could then use that energy
for our own purposes.
564
00:31:18,660 --> 00:31:21,428
About once every million years,
a small asteroid
565
00:31:21,462 --> 00:31:23,063
collides with the Earth,
566
00:31:23,097 --> 00:31:25,465
causing a similar amount
of devastation.
567
00:31:25,500 --> 00:31:27,501
With our current science
and technology,
568
00:31:27,535 --> 00:31:30,437
we already know how to prevent
an asteroid impact.
569
00:31:30,471 --> 00:31:32,439
We would see it coming
years in advance
570
00:31:32,540 --> 00:31:34,141
and could send
a spacecraft there
571
00:31:34,175 --> 00:31:36,443
to deflect it into
a harmless orbit.
572
00:31:36,477 --> 00:31:38,512
With the technology
of a thousand years from now,
573
00:31:38,546 --> 00:31:41,348
we might even be able
to mitigate the deadly effects
574
00:31:41,382 --> 00:31:44,284
of a nearby supernova
on Earth's atmosphere.
575
00:31:44,319 --> 00:31:46,453
But what happens
576
00:31:46,487 --> 00:31:48,922
when the danger
to a civilization is invisible?
577
00:31:48,957 --> 00:31:50,657
When no one can see it coming?
578
00:31:56,230 --> 00:31:57,531
DEGRASSE TYSON:
Beginning with Columbus,
579
00:31:57,565 --> 00:31:59,633
the European invaders
of the Americas
580
00:31:59,667 --> 00:32:03,537
had a secret weapon that even
they knew nothing about.
581
00:32:03,571 --> 00:32:06,473
They were carrying
bacteria and viruses
582
00:32:06,507 --> 00:32:08,609
for deadly diseases,
such as smallpox,
583
00:32:08,643 --> 00:32:12,546
that the original Americans
had never been exposed to.
584
00:32:12,580 --> 00:32:14,548
The Europeans like to believe
585
00:32:14,582 --> 00:32:16,583
that it was their valor
and superior weapons
586
00:32:16,618 --> 00:32:19,453
and culture
that won them the New World.
587
00:32:19,487 --> 00:32:21,722
The real conquistadors were
588
00:32:21,756 --> 00:32:23,991
the armies of the pathogens
that raced on ahead
589
00:32:24,008 --> 00:32:27,828
to infect and kill nine out
of ten of all the Indians
590
00:32:27,862 --> 00:32:30,631
of North, Central
and South America.
591
00:32:32,300 --> 00:32:34,067
The great civilizations
of the New World
592
00:32:34,102 --> 00:32:37,571
crumbled under the onslaught
of invading microbes.
593
00:32:37,605 --> 00:32:39,606
Without his invisible army,
594
00:32:39,641 --> 00:32:41,675
Cortez and those who followed
595
00:32:41,709 --> 00:32:45,479
might never
have stood a chance.
596
00:32:45,513 --> 00:32:49,016
But what about civilizations
that self-destruct?
597
00:32:57,225 --> 00:32:59,826
Our economic systems were
formed when the planet
598
00:32:59,861 --> 00:33:02,696
and its air, rivers,
oceans, lands,
599
00:33:02,730 --> 00:33:06,500
all seemed infinite.
600
00:33:06,534 --> 00:33:09,436
They evolved long before
we first saw the Earth
601
00:33:09,470 --> 00:33:13,140
as the tiny organism
that it actually is.
602
00:33:13,174 --> 00:33:14,808
They're all alike
in one respect:
603
00:33:14,842 --> 00:33:16,476
they're profit-driven,
604
00:33:16,511 --> 00:33:20,247
and therefore,
focused on short-term gain.
605
00:33:46,741 --> 00:33:48,742
The prevailing
economic systems,
606
00:33:48,776 --> 00:33:51,244
no matter what
their ideologies,
607
00:33:51,279 --> 00:33:52,979
have no built-in mechanisms
608
00:33:53,014 --> 00:33:55,015
for protecting our descendants
609
00:33:55,049 --> 00:33:57,050
of even 100 years from now,
610
00:33:57,085 --> 00:33:59,469
let alone, 100,000.
611
00:34:04,459 --> 00:34:06,426
In one respect, we're ahead
612
00:34:06,461 --> 00:34:08,729
of the people
of Ancient Mesopotamia.
613
00:34:08,763 --> 00:34:12,699
Unlike them, we understand
what's happening to our world.
614
00:34:12,734 --> 00:34:15,068
For example,
we're pumping greenhouse gasses
615
00:34:15,103 --> 00:34:17,671
into our atmosphere
at a rate not seen on Earth
616
00:34:17,705 --> 00:34:19,172
for a million years.
617
00:34:19,207 --> 00:34:20,907
And the scientific consensus
618
00:34:20,942 --> 00:34:23,110
that we're destabilizing
our climate.
619
00:34:23,144 --> 00:34:27,047
Yet our civilization seems
to be in the grip of denial;
620
00:34:27,081 --> 00:34:29,583
a kind of paralysis.
621
00:34:29,617 --> 00:34:31,618
There's a disconnect
between what we know
622
00:34:31,652 --> 00:34:33,653
and what we do.
623
00:34:36,557 --> 00:34:40,227
Being able to adapt
our behavior to challenges
624
00:34:40,261 --> 00:34:44,431
is as good a definition
of intelligence as any I know.
625
00:34:48,636 --> 00:34:52,556
If our greater intelligence
is the hallmark of our species,
626
00:34:52,607 --> 00:34:54,057
then we should use it,
627
00:34:54,108 --> 00:34:56,209
as all other beings use their
distinctive advantages--
628
00:34:56,277 --> 00:34:58,645
to help ensure
that their offspring prosper,
629
00:34:58,679 --> 00:35:00,914
and their heredity
is passed on,
630
00:35:00,948 --> 00:35:05,285
and that the fabric of nature
that sustains us is protected.
631
00:35:05,319 --> 00:35:08,121
Human intelligence
is imperfect, surely,
632
00:35:08,156 --> 00:35:10,557
and newly arisen.
633
00:35:10,591 --> 00:35:13,460
The ease with which it can be
sweet-talked, overwhelmed,
634
00:35:13,494 --> 00:35:15,395
or subverted by other
hard-wired tendencies,
635
00:35:15,429 --> 00:35:19,332
sometimes themselves disguised
as the light of reason,
636
00:35:19,367 --> 00:35:21,568
is worrisome.
637
00:35:21,602 --> 00:35:23,837
But if our intelligence
is the only edge,
638
00:35:23,839 --> 00:35:25,472
we must learn to use it better.
639
00:35:25,506 --> 00:35:27,240
To sharpen it.
640
00:35:27,275 --> 00:35:29,576
To understand its limitations
and deficiencies.
641
00:35:29,610 --> 00:35:33,480
To use it as cats use stealth
before pouncing.
642
00:35:33,514 --> 00:35:36,082
As walking sticks
use camouflage.
643
00:35:36,117 --> 00:35:39,286
To make it the tool
of our survival.
644
00:35:39,320 --> 00:35:41,354
If we do this, we can solve
645
00:35:41,389 --> 00:35:44,124
almost any problem
we are likely to confront
646
00:35:44,158 --> 00:35:46,493
in the next 100,000 years.
647
00:35:53,117 --> 00:35:55,268
And now we've arrived
at the place
648
00:35:55,303 --> 00:35:57,771
where our ancient dreams
of immortality
649
00:35:57,805 --> 00:36:01,374
and modern astrophysics
converge.
650
00:36:01,376 --> 00:36:03,476
Giant elliptical galaxies
651
00:36:03,511 --> 00:36:06,012
are something like... Florida,
652
00:36:06,047 --> 00:36:09,749
where the oldest stars
in the universe may be found.
653
00:36:15,489 --> 00:36:17,624
This is a red dwarf star,
654
00:36:17,658 --> 00:36:20,327
smaller and fainter
than our Sun.
655
00:36:20,361 --> 00:36:24,831
Red dwarfs are by far the most
plentiful stars in the cosmos.
656
00:36:24,866 --> 00:36:26,967
Unlike the Sun, which is
halfway through
657
00:36:27,001 --> 00:36:28,969
its 10-billion-year lifetime,
658
00:36:29,003 --> 00:36:31,905
red dwarfs will continue
to provide light and warmth
659
00:36:31,939 --> 00:36:34,841
to their planets
for trillions of years.
660
00:36:34,876 --> 00:36:36,509
That's hundreds of times longer
661
00:36:36,544 --> 00:36:39,646
than the present age
of the universe.
662
00:36:39,680 --> 00:36:41,481
What would
intelligent beings do
663
00:36:41,515 --> 00:36:42,983
if they had an eternity
664
00:36:43,017 --> 00:36:46,319
to develop their understanding
of the universe?
665
00:36:46,354 --> 00:36:48,555
Perhaps they would learn
how to open shortcuts
666
00:36:48,589 --> 00:36:50,724
in the fabric of spacetime,
667
00:36:50,758 --> 00:36:52,659
to travel between galaxies
668
00:36:52,693 --> 00:36:54,494
faster than the speed of light.
669
00:36:54,528 --> 00:36:57,364
Maybe they would create
whole new universes
670
00:36:57,398 --> 00:37:00,867
as artistic
or scientific experiments.
671
00:37:00,902 --> 00:37:03,737
Of course no one,
or at least nobody on Earth,
672
00:37:03,771 --> 00:37:06,539
knows what
the immortals might do.
673
00:37:06,574 --> 00:37:07,741
(film projector whirring)
674
00:37:07,775 --> 00:37:11,845
If one allows
the imagination free reign.
675
00:37:11,879 --> 00:37:13,546
But what about us?
676
00:37:16,584 --> 00:37:18,919
What is our own future?
677
00:37:18,953 --> 00:37:20,954
What would the Cosmic Calendar
678
00:37:20,988 --> 00:37:24,724
of the next 14 billion years
look like?
679
00:37:36,687 --> 00:37:38,521
If the original Cosmic Calendar
680
00:37:38,556 --> 00:37:41,024
includes all of time
from the birth of the universe
681
00:37:41,058 --> 00:37:42,993
until this very moment...
682
00:37:43,027 --> 00:37:45,895
what would
the Cosmic Calendar look like
683
00:37:45,930 --> 00:37:49,699
for the next 14 billion years?
684
00:37:49,734 --> 00:37:52,168
Just as with
the Cosmic Calendar of the past,
685
00:37:52,203 --> 00:37:54,471
every month
on the future calendar
686
00:37:54,505 --> 00:37:56,673
equals about a billion years;
687
00:37:56,707 --> 00:37:59,609
every day, some 40 million.
688
00:38:00,845 --> 00:38:03,680
Science makes it possible
for us to foretell
689
00:38:03,714 --> 00:38:05,748
certain astronomical events
690
00:38:05,750 --> 00:38:08,718
in the unimaginably
distant future--
691
00:38:08,753 --> 00:38:11,021
the death of the Sun,
for example.
692
00:38:11,038 --> 00:38:13,423
In some five billion years,
693
00:38:13,457 --> 00:38:16,693
our star will have
exhausted its hydrogen--
694
00:38:16,727 --> 00:38:18,762
the nuclear fuel
that powers it--
695
00:38:18,796 --> 00:38:20,930
becoming a red giant.
696
00:38:20,965 --> 00:38:22,999
I know that sounds depressing,
697
00:38:23,034 --> 00:38:25,902
but if we apply our
intelligence, our descendants
698
00:38:25,936 --> 00:38:29,005
of that distant future
will have long departed
699
00:38:29,040 --> 00:38:31,841
from the lost worlds
of the Sun.
700
00:38:31,876 --> 00:38:33,677
Who knows?
701
00:38:33,711 --> 00:38:35,712
Human events entail
too many variables,
702
00:38:35,746 --> 00:38:37,447
too many uncertainties,
703
00:38:37,481 --> 00:38:40,016
to make scientific statements
about our future.
704
00:38:40,051 --> 00:38:42,118
But we can still dream.
705
00:38:42,153 --> 00:38:44,888
The next golden age
of human achievement
706
00:38:44,922 --> 00:38:47,090
begins here and now--
707
00:38:47,124 --> 00:38:51,061
New Year's Day
of the next cosmic year.
708
00:38:51,095 --> 00:38:53,196
In the first tenth of a second,
709
00:38:53,230 --> 00:38:56,466
we take the vision
of the pale blue dot to heart,
710
00:38:56,500 --> 00:39:00,070
and learn how to share this
tiny world with each other.
711
00:39:00,104 --> 00:39:02,072
The last
internal combustion engine
712
00:39:02,106 --> 00:39:03,907
is placed in a museum,
713
00:39:03,941 --> 00:39:06,710
as the effects of climate change
reverse and diminish.
714
00:39:06,744 --> 00:39:10,580
A fifth of a second
into this future
715
00:39:10,614 --> 00:39:13,550
people will stop dying
from the effects of poverty.
716
00:39:13,584 --> 00:39:16,619
The planet is now
a completely self-sustaining,
717
00:39:16,654 --> 00:39:19,055
intercommunicating organism.
718
00:39:19,090 --> 00:39:21,124
A half-second from now,
719
00:39:21,158 --> 00:39:22,759
the polar ice caps are restored
720
00:39:22,793 --> 00:39:25,128
to the way they were
in the 19th century,
721
00:39:25,162 --> 00:39:28,098
and the forecast
is mild and pleasant
722
00:39:28,132 --> 00:39:30,400
for the next cosmic
minute and a half--
723
00:39:30,434 --> 00:39:33,470
40,000 years.
724
00:39:33,504 --> 00:39:35,638
By the time
we are ready to settle
725
00:39:35,673 --> 00:39:38,341
even the nearest
other planetary systems,
726
00:39:38,376 --> 00:39:41,177
we will have changed.
727
00:39:41,212 --> 00:39:43,930
The simple passage
of so many generations
728
00:39:43,981 --> 00:39:45,982
will have changed us.
729
00:39:46,016 --> 00:39:49,419
Necessity will have changed us.
730
00:39:49,453 --> 00:39:52,455
We are an adaptable species.
731
00:39:54,191 --> 00:39:56,593
It will not be we
who reach Alpha Centauri
732
00:39:56,627 --> 00:39:58,695
and the other
nearby star systems
733
00:39:58,729 --> 00:40:00,797
on our interstellar arks.
734
00:40:00,831 --> 00:40:03,433
It will be a species
very like us,
735
00:40:03,467 --> 00:40:07,170
but with more of our strengths
and fewer of our weaknesses;
736
00:40:07,204 --> 00:40:09,272
more confident, far-seeing,
737
00:40:09,306 --> 00:40:12,008
capable and wise.
738
00:40:12,042 --> 00:40:13,777
For all our failings,
739
00:40:13,811 --> 00:40:16,279
despite our flaws
and limitations,
740
00:40:16,313 --> 00:40:20,016
we humans are capable
of greatness.
741
00:40:20,050 --> 00:40:23,286
What new wonders,
undreamt of in our time,
742
00:40:23,320 --> 00:40:26,823
will we have accomplished
in another generation...
743
00:40:26,857 --> 00:40:28,858
and another?
744
00:40:30,094 --> 00:40:32,228
How far will
our nomadic species
745
00:40:32,263 --> 00:40:35,799
have wandered
by the end of the next century,
746
00:40:35,833 --> 00:40:38,668
and the next millennium?
747
00:40:38,702 --> 00:40:41,137
Our remote descendants,
748
00:40:41,172 --> 00:40:43,039
safely arrayed on many worlds
749
00:40:43,073 --> 00:40:45,675
throughout the solar system
and beyond,
750
00:40:45,709 --> 00:40:49,045
will be unified
by their common heritage,
751
00:40:49,079 --> 00:40:52,515
by their regard
for their home planet,
752
00:40:52,550 --> 00:40:56,219
and by their knowledge that,
whatever other life may be,
753
00:40:56,253 --> 00:40:59,022
the only humans
in all the universe
754
00:40:59,056 --> 00:41:02,192
came from Earth.
755
00:41:02,226 --> 00:41:04,194
They will gaze up
and strain to find
756
00:41:04,211 --> 00:41:06,963
the blue dot in their skies.
757
00:41:07,031 --> 00:41:09,265
They will marvel
at how vulnerable
758
00:41:09,300 --> 00:41:13,002
the repository of all
our potential once was,
759
00:41:13,004 --> 00:41:15,839
how perilous our infancy,
760
00:41:15,873 --> 00:41:19,943
how humble our beginnings,
761
00:41:19,977 --> 00:41:22,879
how many rivers
we had to cross...
762
00:41:25,816 --> 00:41:28,251
...before we found our way.
763
00:41:30,254 --> 00:41:28,251
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