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¶ ¶
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NEIL DEGRASSE TYSON:
Yes, this is home.
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This is Earth.
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Having trouble finding
a familiar continent?
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The past is another planet.
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Actually, many.
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I'm standing on the great
expanse of time that has elapsed
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since the Big Bang.
In order to think about it,
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we've compressed it all
into a single year.
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It's the early morning
of December 23
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on this Cosmic Calendar of ours,
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or about 350 million years ago,
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when our world was
a mere four billion years old.
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Earth looks so different.
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You might not
even know the place.
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The stars wouldn't help you.
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Even the constellations would
have been different back then.
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The dinosaurs were still
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more than 100 million years
in the future.
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There were no birds,
no flowers.
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And the air was different, too.
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The atmosphere had more oxygen
than at any other time
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in Earth's history,
before or since.
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This allowed insects to grow
much larger than they do today.
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How?
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Insects don't have lungs.
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Life-giving oxygen is taken
in through openings
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in the outside of their bodies
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and transported
through a network of tubes.
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If an insect were too large,
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the outer reaches of these tubes
would absorb all the oxygen
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before it could ever get
to its internal organs.
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But during
the Carboniferous Period,
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the atmosphere had almost twice
the oxygen as today.
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Insects could then grow
much bigger
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and still get enough oxygen
in their bodies.
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That's why the dragonflies here
are as big as eagles
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and the millipedes
the size of alligators.
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So why was there
so much oxygen back then?
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It was produced
by a new kind of life.
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¶ ¶
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¶ ¶
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¶ ¶
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DEGRASSE TYSON: What kind of
life could've changed
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the Earth's atmosphere
so dramatically?
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Plants that could reach
for the sky--
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trees.
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In their competition
for sunlight,
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trees evolved a way
to defy gravity.
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Before trees,
the tallest vegetation was
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only about waist-high.
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And then something wonderful
happened.
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A plant molecule evolved that
was both strong and flexible,
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a material that could support
a lot of weight,
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yet bend in the wind
without breaking.
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Lignin made trees possible.
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Now life could build upward.
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And this opened
a whole new territory,
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a three-dimensional matrix
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for communities
far above the ground.
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Earth became
the Planet of the Trees.
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But lignin had a downside:
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it was hard to swallow.
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When nature's demolition crew,
the fungi and bacteria,
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tried to eat anything
with lignin in it,
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they got a really bad case
of indigestion.
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And termites wouldn't evolve
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for at least
another 100 million years.
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What to do
with all those dead trees?
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It took the fungi and bacteria
millions of years
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to evolve the biochemical means
to consume them.
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Meanwhile, the trees just kept
springing up,
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dying, falling over
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and getting buried by the mud
that built up over eons.
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Eventually, there were
hundreds of billions of trees
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entombed in the Earth,
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buried forests
all over the Earth.
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What possible harm
could come from that?
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(waves crashing in distance)
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This cliff in Nova Scotia
is another kind of calendar.
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It tells the story
of that other world
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that once flourished right here.
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And this is the death mask
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of that 300 million-year-old
tree.
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It was cast by minerals
that replaced the original wood
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cell by cell--
in other words, a fossil.
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The tree surrendered
its organic molecules
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to the environment long ago,
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its carbon and water.
Only its shape remains.
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When this tree was alive,
it took in carbon dioxide
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and water and used sunlight
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to turn them
into energy-rich organic matter.
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The tree gave off oxygen
as a waste product.
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That's what trees
and other plants still do.
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When plants die, they decay,
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and this reverses
the transaction.
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Their organic matter combines
with oxygen
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and decomposes,
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putting carbon dioxide
back into the air.
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This balances the books
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for the chemistry
of Earth's atmosphere.
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But if the trees are buried
before they can decay,
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two things happen:
they take the carbon
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and stored solar energy
with them
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and leave the oxygen behind
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to build up in the atmosphere.
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That's what happened
around 300 million years ago.
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There was an oxygen surplus.
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That's how the bugs got so big.
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And what became
of all that buried carbon?
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It lay there for eons
before dealing life on Earth
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its most devastating blow
of all time.
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There are places on this planet
where you can walk through time
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and read the history
written in the rocks.
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This beach in Nova Scotia
is one of them.
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Every layer is a page.
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Each one tells the story
of a flood,
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one after another,
over millions of years.
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The layer cake of flood
deposits was slowly buried
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and turned into rock
by heat and pressure.
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The same forces
that built mountains
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then tilted and uplifted them,
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along with the entombed
fossil forest.
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The newer layers were always
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deposited on top
of the older ones.
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All the pages are
in the correct order,
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bearing witness
to what happened here
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over millions of years.
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Back that way
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lies the more distant past.
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And with every step I take,
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I move about 1,000 years
closer to the present
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and away from the world
of 300 million years ago.
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50 million years later
lies that way.
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This was the beginning of
the end of the Permian world,
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an event
of unequalled carnage.
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The Permian
is the darkest corridor
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in this memorial to the broken
branches on the Tree of Life--
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the Halls of Extinction.
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Death has never come so close
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to reigning supreme
on this world
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in the quarter billion years
since.
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The eruptions,
in what is now Siberia,
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lasted for hundreds
of thousands of years.
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The lava flooded and buried more
than a million square miles.
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This event dwarfs
any volcanic eruption
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in historical times.
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Huge quantities
of carbon dioxide came pouring
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out of the volcanic fissures.
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This greenhouse gas
warmed the climate.
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And this is where
the long-buried forests
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of the earlier Carboniferous
Period reenter the story.
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During the intervening
50 million years,
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those trees had turned
into immense deposits of coal,
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and as it happened,
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one of the world's largest
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accumulations of coal
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was buried right there
in Siberia.
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The heat from the lava
baked the coal,
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driving methane and sulfur-rich
gases out of the ground.
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They were laden
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with toxic
and radioactive ash particles--
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coal smoke.
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This witch's brew
polluted the atmosphere
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and radically destabilized
Earth's climate.
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A sulfuric acid haze
blocked incoming sunlight
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and darkened the planet.
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Global temperatures plummeted
to subfreezing.
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During lulls in the eruptions,
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the acid haze fell back
to the surface.
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But the carbon dioxide remained
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and built up in the atmosphere
to cause global warming.
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Years of frigid cold
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alternating with millennia
of stifling heat
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battered a dwindling population
of plants and animals.
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They had no chance
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to adapt to the drastic swings
in climate.
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As the global warming
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continued, the surface
and the bottom waters
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slowly mixed,
raising the temperature
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of the once-frigid depths
of the sea floor.
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Methane-rich ices
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that had been frozen in
the sediments began to melt.
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Newly liberated methane gas
made its way to the surface
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and into the atmosphere.
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Methane traps heat
far more efficiently
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than carbon dioxide,
so the climate
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got even hotter.
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And the methane also destroyed
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the ozone layer
in the stratosphere.
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The natural sunscreen
that protects life
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from deadly ultraviolet rays
was eaten away.
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The circulatory system
of the world ocean shut down.
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These stagnant waters
became oxygen-starved,
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killing almost all
the fish in the sea.
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But one kind of life flourished
in this brutal environment:
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bacteria that produced
deadly hydrogen sulfide gas
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as a waste product.
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That was the last straw.
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The poison gas killed almost
all the remaining plants
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and animals on the land.
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This was the Great Dying.
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The closest life on Earth
has ever come to annihilation.
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Nine in ten
of all species perished.
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It took a long time
for life to bounce back.
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For a few million years,
Earth could have been called
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the Planet of the Dead.
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We are descended
from one of the few species
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that managed to squeak by.
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You are human and alive
at this very moment
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because they managed
to endure, conveying
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their DNA through one of
the most treacherous periods
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00:12:23,793 --> 00:12:25,944
in the history of life.
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DEGRASSE TYSON:
This mountain was made
entirely by life.
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The life that flourished
back in the glory days
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of the Permian,
before all hell broke loose.
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This is part
of the 400 mile-long
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00:12:51,470 --> 00:12:53,538
Guadalupe Mountain chain
that runs through
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Texas and New Mexico.
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It's the world's
largest fossil reef.
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All this was once
a great inland sea.
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The reef flourished and grew
for millions of years,
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and was home to multitudes
of sponges, green algae,
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and animals too small to see.
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When these creatures died,
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00:13:14,193 --> 00:13:17,295
they sank to the bottom
and were buried in the silt.
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Over millions of years,
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00:13:19,532 --> 00:13:22,500
their remains were converted
into oil and gas.
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00:13:22,535 --> 00:13:24,502
Eventually, the basin
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00:13:24,537 --> 00:13:26,905
silted in and the reef died.
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This marine ghost town
was then buried
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00:13:29,708 --> 00:13:31,409
a mile beneath the surface.
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00:13:31,443 --> 00:13:34,479
Later, tectonic forces
lifted the skeletal reef
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00:13:34,513 --> 00:13:37,649
high above sea level,
where it was eroded and sculpted
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over eons by wind and rain.
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00:13:39,885 --> 00:13:42,153
Just imagine what
this place looked like
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275 million years ago,
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when it was a vibrant,
tropical inland sea,
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dotted with islands
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and brimming with life.
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Until about
220 million years ago,
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New England and North Africa
were next-door neighbors.
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There was no such thing
as the Atlantic Ocean.
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00:14:03,742 --> 00:14:08,079
Those thin blue fingers
at the center-- they were lakes.
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They were the first outward
signs that the supercontinent
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was splitting apart and that
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00:14:12,618 --> 00:14:15,787
life on Earth was due
for another big shake-up.
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00:14:15,821 --> 00:14:19,090
A million years later,
the lakes became a long bay,
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00:14:19,124 --> 00:14:22,026
which would grow
into the Atlantic Ocean.
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00:14:22,061 --> 00:14:24,629
These profound changes
at the surface
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00:14:24,663 --> 00:14:28,766
were merely symptoms of a drama
that was unfolding far beneath,
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00:14:28,801 --> 00:14:30,101
in the depths of the Earth.
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00:14:32,504 --> 00:14:35,373
By the time we got here,
the telltale traces
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00:14:35,407 --> 00:14:37,141
of global upheaval were buried
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00:14:37,176 --> 00:14:39,377
at the bottom
of the deep blue sea.
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00:14:39,411 --> 00:14:41,913
We were completely cut off
from the great story
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00:14:41,947 --> 00:14:43,548
of Earth's violent past--
258
00:14:43,582 --> 00:14:47,318
a species of amnesiacs
trying to find out
259
00:14:47,353 --> 00:14:50,221
who we were
and what happened
260
00:14:50,256 --> 00:14:52,290
before we awakened.
261
00:14:52,324 --> 00:14:56,094
In 1570, Abraham Ortelius
created the first
262
00:14:56,128 --> 00:14:59,597
modern world atlas,
reflecting on the discoveries
263
00:14:59,632 --> 00:15:01,399
of the previous 80 years--
264
00:15:01,433 --> 00:15:04,636
the Golden Age of Exploration.
265
00:15:04,670 --> 00:15:06,437
Before the ink was dry,
266
00:15:06,472 --> 00:15:08,907
Ortelius stepped back
from his masterpiece
267
00:15:08,941 --> 00:15:12,277
and became the first of many
to notice the striking
268
00:15:12,311 --> 00:15:14,579
puzzle-piece fit
between the continents
269
00:15:14,613 --> 00:15:16,981
on either side of the Atlantic.
270
00:15:17,016 --> 00:15:20,251
He later wrote that the
Americas were torn away
271
00:15:20,286 --> 00:15:23,321
from Europe and Africa
by earthquakes and floods.
272
00:15:23,355 --> 00:15:25,123
But Ortelius's observation
273
00:15:25,157 --> 00:15:26,958
remained nothing more
than a hunch
274
00:15:26,992 --> 00:15:28,960
for the next
couple of centuries...
275
00:15:30,362 --> 00:15:32,830
...until an early 20th century
276
00:15:32,865 --> 00:15:34,832
German astronomer
and meteorologist
277
00:15:34,867 --> 00:15:36,367
amassed the evidence
278
00:15:36,402 --> 00:15:38,836
to build the
scientific case for it.
279
00:15:38,871 --> 00:15:42,006
Alfred Wegener had been drafted
during the first World War,
280
00:15:42,041 --> 00:15:44,475
but was wounded soon after.
281
00:15:44,510 --> 00:15:46,811
As he recovered
in a field hospital,
282
00:15:46,845 --> 00:15:48,947
he scoured scientific
literature
283
00:15:48,981 --> 00:15:51,666
for clues to the Earth's past.
284
00:15:51,717 --> 00:15:53,384
Years before,
285
00:15:53,419 --> 00:15:55,820
Wegener had happened upon
an intriguing paper
286
00:15:55,854 --> 00:15:57,372
in the stacks
of his university library.
287
00:15:57,423 --> 00:16:00,158
It puzzled Wegener
288
00:16:00,192 --> 00:16:03,628
that fossils of the same
species of a now-extinct fern
289
00:16:03,662 --> 00:16:08,299
were reported to be found
on both sides of the Atlantic.
290
00:16:08,334 --> 00:16:11,035
Even more curious were
the discoveries of fossils
291
00:16:11,070 --> 00:16:14,238
of the same dinosaurs
on both continents.
292
00:16:14,273 --> 00:16:16,174
In the early 20th century,
293
00:16:16,208 --> 00:16:18,743
geologists explained
how life crossed the oceans
294
00:16:18,777 --> 00:16:23,581
by imagining that land bridges
had once existed between them.
295
00:16:23,615 --> 00:16:27,051
It was thought that these land
bridges gradually disintegrated
296
00:16:27,086 --> 00:16:30,355
and vanished
beneath the waves long ago.
297
00:16:30,389 --> 00:16:32,923
But there was one piece of
evidence that convinced Wegener
298
00:16:32,925 --> 00:16:36,227
that the prevailing
scientific view must be wrong:
299
00:16:36,229 --> 00:16:38,830
the Earth itself.
300
00:16:38,864 --> 00:16:42,400
Why would a mountain range
cross the oceanic divide
301
00:16:42,418 --> 00:16:44,602
to continue
on another continent?
302
00:16:44,636 --> 00:16:46,738
And why would you find
the same unique pattern
303
00:16:46,772 --> 00:16:50,408
in the layers of rocks in both
Brazil and South Africa?
304
00:16:50,442 --> 00:16:52,410
And another thing:
305
00:16:52,428 --> 00:16:55,680
under what circumstances could
tropical plants have flourished
306
00:16:55,714 --> 00:16:59,083
in the frozen wastes
of the Arctic?
307
00:16:59,118 --> 00:17:01,219
Wegener concluded
that there was only
308
00:17:01,253 --> 00:17:03,955
one logical solution
to this puzzle:
309
00:17:03,989 --> 00:17:07,458
There had once been a single
supercontinent on Earth.
310
00:17:07,460 --> 00:17:10,862
He named it Pangaea.
311
00:17:10,896 --> 00:17:14,732
So Wegener becomes the toast
of the scientific world, right?
312
00:17:14,767 --> 00:17:16,701
Not exactly.
313
00:17:16,735 --> 00:17:19,103
Most geologists ridiculed
Wegener's hypothesis
314
00:17:19,171 --> 00:17:21,105
of continental drift.
315
00:17:21,140 --> 00:17:25,076
They preferred their
imaginary natural land bridges
316
00:17:25,110 --> 00:17:27,111
to explain away
Wegener's evidence.
317
00:17:29,014 --> 00:17:32,250
How, they asked, could
a continent plow through
318
00:17:32,284 --> 00:17:35,086
the solid rock
of the ocean floor?
319
00:17:35,120 --> 00:17:37,989
Wegener had no
convincing answer.
320
00:17:38,023 --> 00:17:40,124
He became the laughingstock
of the field;
321
00:17:40,159 --> 00:17:43,227
a pariah at scientific
conferences.
322
00:17:43,262 --> 00:17:44,962
(dogs barking)
323
00:17:44,997 --> 00:17:47,732
Despite this, Wegener continued
to fight for his ideas,
324
00:17:47,766 --> 00:17:51,102
conducting daring research
expeditions to gather evidence.
325
00:17:51,136 --> 00:17:54,939
On one of these, he learned
that colleagues were
326
00:17:54,941 --> 00:17:57,809
trapped on an ice cap
without food.
327
00:17:57,843 --> 00:18:00,011
On his way back
from the mission,
328
00:18:00,045 --> 00:18:01,979
he became lost in a blizzard.
329
00:18:02,014 --> 00:18:04,816
A day or two after
his 50th birthday,
330
00:18:04,850 --> 00:18:06,150
he disappeared,
331
00:18:06,185 --> 00:18:08,319
never knowing that, in time,
332
00:18:08,353 --> 00:18:10,755
he would be vindicated
and come to be viewed
333
00:18:10,789 --> 00:18:14,358
as one of the greatest
geologists in history.
334
00:18:19,465 --> 00:18:21,666
Scientists are human.
335
00:18:21,700 --> 00:18:23,468
We have our blind spots
and prejudices.
336
00:18:23,502 --> 00:18:26,370
Science is a mechanism
337
00:18:26,405 --> 00:18:28,372
designed to ferret them out.
338
00:18:28,407 --> 00:18:30,775
Problem is, we aren't
always faithful
339
00:18:30,777 --> 00:18:32,610
to the core values of science.
340
00:18:32,644 --> 00:18:36,948
Few people knew this better
than Marie Tharp.
341
00:18:42,921 --> 00:18:46,958
It's 1952, and Marie is
patiently enduring the slights
342
00:18:46,992 --> 00:18:49,627
of her fellow members
of the geology department.
343
00:18:49,661 --> 00:18:51,796
Her degrees in geology
and mathematics
344
00:18:51,830 --> 00:18:53,498
count for little with them.
345
00:18:53,500 --> 00:18:56,667
Bruce Heezen, a graduate
student from Iowa,
346
00:18:56,702 --> 00:18:58,903
has just returned
from a lengthy expedition
347
00:18:58,905 --> 00:19:01,706
to map the ocean floor
using sonar.
348
00:19:03,442 --> 00:19:04,575
(Heezen grunts)
349
00:19:04,610 --> 00:19:06,611
Will you do something
with these?
350
00:19:11,683 --> 00:19:14,385
Bruce, look.
351
00:19:14,419 --> 00:19:15,520
It's-it's all come together.
352
00:19:15,554 --> 00:19:17,388
There's this giant rift valley
353
00:19:17,390 --> 00:19:19,390
that runs through
the bottom of the Atlantic.
354
00:19:19,424 --> 00:19:20,591
Aw, geez, Marie, come on.
355
00:19:20,626 --> 00:19:22,393
This is just more girl talk.
356
00:19:22,427 --> 00:19:25,095
You're not in enough trouble
with everyone here already?
357
00:19:25,097 --> 00:19:27,031
This sounds too much
like continental drift.
358
00:19:27,065 --> 00:19:29,033
You want to end up
like Wegener?
359
00:19:31,370 --> 00:19:35,273
DEGRASSE TYSON:
But Marie would not
be dissuaded.
360
00:19:35,307 --> 00:19:39,177
Years later, when Marie and
Bruce placed a map of oceanic
361
00:19:39,211 --> 00:19:41,612
earthquake epicenters
on a light table
362
00:19:41,647 --> 00:19:43,097
over her seafloor map,
363
00:19:43,148 --> 00:19:44,949
the earthquakes
fell right along
364
00:19:44,983 --> 00:19:46,184
the rift valley.
365
00:19:46,218 --> 00:19:48,853
This was the smoking gun
366
00:19:48,887 --> 00:19:50,721
for Wegener's
moving continents.
367
00:19:50,756 --> 00:19:52,623
Heezen now knew
368
00:19:52,658 --> 00:19:55,927
that Marie had been
right all along.
369
00:19:55,961 --> 00:19:58,796
Together, they created the
first true map of the Earth,
370
00:19:58,830 --> 00:20:01,632
including the ocean floor.
371
00:20:04,670 --> 00:20:06,938
We were at last ready to read
372
00:20:06,972 --> 00:20:08,973
the autobiography of the Earth.
373
00:20:12,544 --> 00:20:16,180
DEGRASSE TYSON: Let's take
the Ship of the Imagination...
374
00:20:16,214 --> 00:20:18,916
to a part of the world
that has been off-limits
375
00:20:18,951 --> 00:20:21,052
to all but a few of us.
376
00:20:34,366 --> 00:20:35,866
Two-thirds of the Earth
377
00:20:35,901 --> 00:20:39,503
lies beneath more than
1,000 feet of water.
378
00:20:39,538 --> 00:20:42,840
It's a vast and largely
unexplored frontier.
379
00:20:42,874 --> 00:20:45,409
Everybody knows the Alps
and the Rockies,
380
00:20:45,444 --> 00:20:48,029
but some of the world's
most amazing mountain ranges
381
00:20:48,079 --> 00:20:49,614
are hidden from view.
382
00:20:51,917 --> 00:20:55,419
Below 1,000 meters,
we enter a world
383
00:20:55,454 --> 00:20:57,221
where there is no sunlight.
384
00:20:58,790 --> 00:21:02,460
Hidden in the darkness,
a world of wonders.
385
00:21:05,063 --> 00:21:08,366
This is the longest submarine
mountain range in the world,
386
00:21:08,400 --> 00:21:11,585
the Atlantic Mid-Ocean Ridge.
387
00:21:11,637 --> 00:21:15,640
It wraps around our globe
like the seam on a baseball.
388
00:21:18,844 --> 00:21:22,647
The past is another planet,
389
00:21:22,681 --> 00:21:25,916
but most of us
don't really know this one.
390
00:21:25,951 --> 00:21:29,587
We don't see the mountains
for the water.
391
00:21:29,621 --> 00:21:33,157
This is the world that Marie
Tharp was the first to imagine.
392
00:21:33,159 --> 00:21:35,159
The highest peaks of the ridge
393
00:21:35,193 --> 00:21:37,728
rise over four kilometers above
394
00:21:37,763 --> 00:21:39,563
the ocean floor.
395
00:21:39,598 --> 00:21:42,500
There are sprawling mountain
ranges and canyons, too.
396
00:21:42,534 --> 00:21:45,169
We've now entered
the Marianas Trench,
397
00:21:45,203 --> 00:21:46,937
the deepest canyon on Earth,
398
00:21:46,972 --> 00:21:49,840
more than ten kilometers deep.
399
00:21:49,875 --> 00:21:52,810
It formed when tectonic forces
pushed the seabed
400
00:21:52,844 --> 00:21:54,812
under the adjoining
continental plate.
401
00:21:54,846 --> 00:21:57,248
More people have walked
on the Moon
402
00:21:57,282 --> 00:21:59,850
than have ever been down here.
403
00:21:59,885 --> 00:22:04,121
The pressure here is a crushing
eight tons per square inch.
404
00:22:04,156 --> 00:22:06,323
Being this deep in the ocean
405
00:22:06,358 --> 00:22:10,027
is like having 50 jumbo jets
stacked on top of you.
406
00:22:10,062 --> 00:22:13,864
Yet even here,
life has taken hold.
407
00:22:16,535 --> 00:22:19,937
The fact that sunlight
can't penetrate the deep ocean
408
00:22:19,971 --> 00:22:22,540
doesn't mean
there isn't light down here.
409
00:22:22,574 --> 00:22:25,543
Many underwater species glow
in the dark,
410
00:22:25,577 --> 00:22:28,612
through a process
called bioluminescence.
411
00:22:28,647 --> 00:22:31,515
Our long history
as land mammals,
412
00:22:31,583 --> 00:22:34,685
denizens of the sunlit world,
hasn't prepared us
413
00:22:34,720 --> 00:22:37,455
for the amazing variety of life
that evolution
414
00:22:37,489 --> 00:22:40,057
has crafted in the deep oceans.
415
00:22:42,394 --> 00:22:44,729
Since there's no sunlight
down here,
416
00:22:44,763 --> 00:22:47,181
there's no photosynthesis.
417
00:22:47,232 --> 00:22:51,302
That means there are
no plants to feed on,
418
00:22:51,336 --> 00:22:54,705
and yet, even here, in a world
of permanent midnight,
419
00:22:54,740 --> 00:22:56,690
there's a thriving food chain.
420
00:22:56,742 --> 00:22:58,042
It begins
421
00:22:58,076 --> 00:23:00,511
with a process
called chemosynthesis.
422
00:23:00,545 --> 00:23:03,514
These microscopic creatures
have learned to eat
423
00:23:03,516 --> 00:23:07,184
what's pouring out
of that vent...
424
00:23:07,219 --> 00:23:10,254
a noxious compound
called hydrogen sulfide.
425
00:23:10,288 --> 00:23:11,689
That thick
426
00:23:11,723 --> 00:23:14,358
black smoke provides
the chemical energy
427
00:23:14,392 --> 00:23:16,527
that makes life possible here.
428
00:23:16,561 --> 00:23:19,530
Tiny crustaceans
eat the bacteria,
429
00:23:19,564 --> 00:23:22,967
and the larger animals
eat the crustaceans.
430
00:23:26,438 --> 00:23:28,906
One day, on some future Earth,
431
00:23:28,940 --> 00:23:30,508
these mountains could very well
432
00:23:30,609 --> 00:23:32,910
end up above the water.
433
00:23:32,944 --> 00:23:36,113
Tectonic forces continue
to shape our planet.
434
00:23:36,148 --> 00:23:40,084
The future
is also another planet.
435
00:23:40,118 --> 00:23:42,286
It was a volcano like thisis one
436
00:23:42,320 --> 00:23:46,924
that created the Hawaiian
islands millions of years ago.
437
00:24:06,578 --> 00:24:09,980
We live on the crust
of a seething cauldron.
438
00:24:10,081 --> 00:24:13,117
At the center of our planet,
there's an iron core.
439
00:24:13,151 --> 00:24:16,954
It's nested inside
of a larger, liquid iron shell.
440
00:24:16,988 --> 00:24:20,791
Wrapped over this is the part
called the mantle.
441
00:24:20,826 --> 00:24:23,727
It's rocky but hot and viscous.
442
00:24:23,762 --> 00:24:27,231
Like a pot of soup cooking
on a stove, the mantle
443
00:24:27,265 --> 00:24:28,465
is churning.
444
00:24:28,500 --> 00:24:30,501
What keeps it moving?
445
00:24:30,535 --> 00:24:34,405
Two things: the heat left over
from Earth's formation,
446
00:24:34,439 --> 00:24:38,075
and the decay of radioactive
elements in the core.
447
00:24:38,109 --> 00:24:40,678
And this outer layer--
the crust,
448
00:24:40,712 --> 00:24:43,747
where you and me
and everyone we know lives--
449
00:24:43,749 --> 00:24:46,150
is only as thick
as the skin on an apple.
450
00:24:46,184 --> 00:24:47,852
The mantle
451
00:24:47,886 --> 00:24:51,088
drags the solid overlying
crust along with it.
452
00:24:51,122 --> 00:24:54,458
The crust resists
because it's cool and rigid.
453
00:24:54,492 --> 00:24:58,262
From time to time,
it reaches the breaking point.
454
00:24:58,296 --> 00:25:01,599
When that happens,
the Earth quakes.
455
00:25:01,633 --> 00:25:04,201
It's not because
somebody misbehaved
456
00:25:04,236 --> 00:25:05,970
and is being punished.
457
00:25:06,004 --> 00:25:07,805
It's due to random forces
458
00:25:07,839 --> 00:25:10,274
that are governed
by the laws of nature.
459
00:25:10,308 --> 00:25:13,611
Our sense of the stability
of the Earth is an illusion
460
00:25:13,645 --> 00:25:15,813
due to the shortness
of our lives.
461
00:25:15,847 --> 00:25:19,717
If we could watch our planet
on its own timescale,
462
00:25:19,751 --> 00:25:24,355
in which big changes take
millions of years to play out,
463
00:25:24,389 --> 00:25:29,026
we would see it as the dynamic
organism it really is.
464
00:25:29,060 --> 00:25:31,061
(rumbling, crackling)
465
00:25:34,332 --> 00:25:37,735
This is the world
of the late Triassic period
466
00:25:37,769 --> 00:25:40,905
about 200 million years ago.
467
00:25:40,907 --> 00:25:43,040
That little guy?
468
00:25:43,074 --> 00:25:45,509
It's one of
our distant ancestors.
469
00:25:45,543 --> 00:25:48,445
He lived in Newark, New Jersey.
470
00:25:50,749 --> 00:25:54,919
Wherever you walk on Earth...
471
00:25:54,953 --> 00:25:57,922
lost worlds lie buried
beneath your feet.
472
00:25:57,956 --> 00:26:00,157
50 or 100 million years ago,
473
00:26:00,191 --> 00:26:02,660
even the most
seemingly ordinary places
474
00:26:02,694 --> 00:26:05,362
have been the scene
of epic change.
475
00:26:05,397 --> 00:26:07,765
These Palisades are a monument
476
00:26:07,799 --> 00:26:11,001
to the breakup of
the supercontinent Pangaea.
477
00:26:11,036 --> 00:26:13,170
The sequence
of volcanic eruptions
478
00:26:13,204 --> 00:26:17,541
that made these cliffs also led
to the next mass extinction--
479
00:26:17,575 --> 00:26:20,678
the one that ended
the Triassic world.
480
00:26:20,712 --> 00:26:22,012
But a catastrophic
481
00:26:22,047 --> 00:26:24,348
extinction event for one species
482
00:26:24,382 --> 00:26:26,417
is a golden opportunity
for another.
483
00:26:30,789 --> 00:26:33,190
The Triassic extinctions
offered one group
484
00:26:33,224 --> 00:26:35,125
that had been around
for a while
485
00:26:35,160 --> 00:26:36,927
the chance
to take center stage.
486
00:26:40,832 --> 00:26:43,100
The dinosaurs
had a good, long run
487
00:26:43,134 --> 00:26:46,236
for 170 million years.
488
00:26:46,271 --> 00:26:50,074
Back then, India was an island.
489
00:26:50,108 --> 00:26:53,777
It crept northward at the pace
of a few inches per year
490
00:26:53,845 --> 00:26:57,614
on its slow but inexorable
rendezvous with Asia.
491
00:26:57,649 --> 00:26:59,717
Then, once again,
492
00:26:59,751 --> 00:27:02,219
the molten rock beneath
Earth's surface
493
00:27:02,253 --> 00:27:06,290
burst forth and flooded
a huge area of western India.
494
00:27:12,831 --> 00:27:14,932
The knockout punch
495
00:27:14,966 --> 00:27:17,835
literally came out of the blue.
496
00:27:32,901 --> 00:27:35,469
(rumbling, whooshing)
497
00:27:53,488 --> 00:27:55,289
Few animals
498
00:27:55,323 --> 00:27:56,824
larger than a hundred pounds
499
00:27:56,858 --> 00:27:59,893
survived the catastrophes
of the late Cretaceous.
500
00:27:59,928 --> 00:28:04,231
The dust cloud brought night and
cold to the surface for months.
501
00:28:04,265 --> 00:28:06,500
The dinosaurs froze
and starved to death.
502
00:28:06,534 --> 00:28:08,502
But there were small creatures
503
00:28:08,536 --> 00:28:10,504
who took shelter in the Earth.
504
00:28:10,538 --> 00:28:12,439
And when they emerged...
505
00:28:12,474 --> 00:28:14,475
they found that
the monsters who had hunted
506
00:28:14,509 --> 00:28:16,977
and terrorized them were gone.
507
00:28:17,011 --> 00:28:20,814
The Earth was becoming
the Planet of the Mammals.
508
00:28:20,816 --> 00:28:24,785
And the Earth continued
its ceaseless changing.
509
00:28:26,721 --> 00:28:29,857
This was once a desert
where nothing could grow.
510
00:28:29,891 --> 00:28:33,594
It was a million square miles
of sand and salt,
511
00:28:33,628 --> 00:28:36,964
far more hostile than
any environment on Earth today.
512
00:28:36,998 --> 00:28:40,534
Daytime temperatures were
hot enough to bake bread.
513
00:28:40,568 --> 00:28:43,203
And it was more than a mile
below sea level,
514
00:28:43,238 --> 00:28:45,005
so the atmospheric pressure
515
00:28:45,039 --> 00:28:47,608
was about 50% higher
than what we're used to.
516
00:28:47,642 --> 00:28:49,376
It would be hard to think
517
00:28:49,411 --> 00:28:52,179
of a more unpromising
environment on this planet.
518
00:28:52,213 --> 00:28:54,982
Yet this was the basin
of the Mediterranean
519
00:28:55,016 --> 00:28:57,484
five and a half
million years ago,
520
00:28:57,519 --> 00:28:59,686
before it became a sea.
521
00:28:59,721 --> 00:29:02,656
The Earth never
stops moving for long.
522
00:29:02,690 --> 00:29:05,159
The natural dam
at the western end
523
00:29:05,193 --> 00:29:06,794
of the deep basin
524
00:29:06,828 --> 00:29:09,463
gave way,
probably due to earthquakes.
525
00:29:09,497 --> 00:29:13,000
And the deluge began.
526
00:29:13,034 --> 00:29:16,737
The torrential waters rushed in
at a rate 40,000 times greater
527
00:29:16,771 --> 00:29:19,206
than Niagara Falls,
turning a vast desert
528
00:29:19,240 --> 00:29:21,608
into the Mediterranean Sea...
529
00:29:22,777 --> 00:29:25,646
...in less than a year.
530
00:29:25,680 --> 00:29:27,815
There were as yet no humans
531
00:29:27,849 --> 00:29:30,050
to witness this enormous flood,
532
00:29:30,084 --> 00:29:32,853
nor to admire
the beauty it created.
533
00:29:32,887 --> 00:29:35,255
Meanwhile, half a world away,
534
00:29:35,290 --> 00:29:39,026
a broad channel separated
North and South America...
535
00:29:39,060 --> 00:29:41,228
allowing ocean currents to flow
536
00:29:41,262 --> 00:29:43,897
from the Atlantic
into the Pacific Ocean.
537
00:29:43,932 --> 00:29:46,099
Tectonic forces
gradually brought
538
00:29:46,134 --> 00:29:48,769
these two continents together,
closing the channel
539
00:29:48,803 --> 00:29:52,105
and creating
the Isthmus of Panama.
540
00:29:52,140 --> 00:29:55,309
This reorganized the worldwide
pattern of ocean currents,
541
00:29:55,410 --> 00:29:58,145
which, in turn, affected
the global climate.
542
00:30:00,915 --> 00:30:03,784
In Africa,
the lush green forest canopy
543
00:30:03,818 --> 00:30:06,186
gave way
to a sparser landscape.
544
00:30:06,221 --> 00:30:08,021
Some species
545
00:30:08,056 --> 00:30:10,724
that were highly specialized
for life in the trees
546
00:30:10,758 --> 00:30:12,593
became extinct.
547
00:30:12,627 --> 00:30:15,529
But the generalists, the ones
that could find a way
548
00:30:15,563 --> 00:30:17,865
to make a living no matter what
life threw at them,
549
00:30:17,899 --> 00:30:20,634
endured and evolved.
550
00:30:23,671 --> 00:30:27,241
Our ancestors had once
burrowed deep in the ground
551
00:30:27,275 --> 00:30:29,610
to avoid predators
who stalked the surface.
552
00:30:29,644 --> 00:30:31,912
But when
the dinosaurs perished,
553
00:30:31,946 --> 00:30:33,747
they emerged into the daylight,
554
00:30:33,781 --> 00:30:35,649
and over the eons,
made new lives
555
00:30:35,683 --> 00:30:37,718
in the branches of the trees.
556
00:30:37,752 --> 00:30:40,287
They developed
opposable thumbs and toes
557
00:30:40,321 --> 00:30:41,755
for swinging
from branch to branch,
558
00:30:41,789 --> 00:30:43,790
across the broad canopy
of treetops,
559
00:30:43,825 --> 00:30:46,059
where all their needs
were fulfilled.
560
00:30:46,094 --> 00:30:49,830
They could also walk upright,
but only for short distances.
561
00:30:49,864 --> 00:30:53,467
With so many trees around, they
didn't have to go very far.
562
00:30:53,501 --> 00:30:55,469
But then it got colder,
563
00:30:55,503 --> 00:30:57,271
and the trees thinned out,
564
00:30:57,305 --> 00:30:59,940
broad grasslands sprang up,
and our ancestors
565
00:30:59,974 --> 00:31:02,743
were forced to traverse them
in search of food.
566
00:31:02,777 --> 00:31:04,778
You needed
a totally different skill set
567
00:31:04,812 --> 00:31:06,613
to make it on the savanna.
568
00:31:06,648 --> 00:31:08,115
In the old days,
569
00:31:08,149 --> 00:31:10,117
you could sit
perched on your tree branch
570
00:31:10,151 --> 00:31:12,586
and watch the big cats
from a safe distance.
571
00:31:12,620 --> 00:31:16,189
Now you were playing
on the same dangerous field.
572
00:31:17,492 --> 00:31:19,660
(growling)
573
00:31:19,694 --> 00:31:22,329
The survivors were those
who evolved the ability
574
00:31:22,363 --> 00:31:24,965
to walk great distances
on their hind legs
575
00:31:24,999 --> 00:31:26,266
and to run when necessary.
576
00:31:26,334 --> 00:31:27,367
(growlin
577
00:31:27,402 --> 00:31:28,802
This changed the way
578
00:31:28,836 --> 00:31:30,537
they looked at the world.
579
00:31:30,572 --> 00:31:33,807
Hands and arms were no longer
tied up with walking.
580
00:31:33,809 --> 00:31:37,978
They were free to gather food
and pick up sticks and bones.
581
00:31:38,012 --> 00:31:40,547
These could be used
as weapons and tools.
582
00:31:40,582 --> 00:31:42,382
Think of it:
583
00:31:42,417 --> 00:31:45,986
A change in the topography
of a small piece of land
584
00:31:46,020 --> 00:31:49,289
half a world away
reroutes ocean currents.
585
00:31:49,324 --> 00:31:51,658
Africa grows colder and drier.
586
00:31:51,693 --> 00:31:54,561
Most of the trees can't
withstand the new climate.
587
00:31:54,596 --> 00:31:56,663
The primates who lived in them
588
00:31:56,698 --> 00:31:59,833
have to seek other homes,
and before you know it,
589
00:31:59,867 --> 00:32:02,869
they're using tools
to remake the planet.
590
00:32:02,904 --> 00:32:06,740
The Earth has shaped the course
of human destiny,
591
00:32:06,774 --> 00:32:11,545
but so has the invisible pull
of distant worlds.
592
00:32:35,720 --> 00:32:37,554
DEGRASSE TYSON:
The planets have influenced
593
00:32:37,588 --> 00:32:40,891
our lives,
but not in the way you think.
594
00:32:40,925 --> 00:32:42,926
The gravitational pull
of Venus--
595
00:32:42,960 --> 00:32:45,462
small but close--
596
00:32:45,496 --> 00:32:49,099
and that of Jupiter--
distant but massive--
597
00:32:49,133 --> 00:32:53,603
tilted the Earth's axis
this way and that...
598
00:32:55,907 --> 00:32:59,309
...and ever so slightly tweaked
the shape of its orbit.
599
00:33:01,913 --> 00:33:03,447
This periodically altered
600
00:33:03,481 --> 00:33:04,881
the amount of sunlight
601
00:33:04,916 --> 00:33:07,017
falling on the edge
of the northern ice cap.
602
00:33:10,321 --> 00:33:12,723
Sometimes it made
the summers there colder,
603
00:33:12,757 --> 00:33:14,491
and the glaciers
advanced southward
604
00:33:14,525 --> 00:33:16,293
from one year to the next,
605
00:33:16,327 --> 00:33:17,761
grinding and scraping,
606
00:33:17,795 --> 00:33:20,597
and crushing everything
in their path.
607
00:33:22,433 --> 00:33:24,568
That's what we call an ice age.
608
00:33:24,570 --> 00:33:27,804
At other times, changes
in Earth's axis and orbit
609
00:33:27,839 --> 00:33:29,706
made the Arctic summers warmer.
610
00:33:31,376 --> 00:33:33,977
And the melting glaciers
began to retreat.
611
00:33:35,380 --> 00:33:38,081
Imagine how resourceful
our ancestors had to be
612
00:33:38,083 --> 00:33:41,184
in order to survive these
radical changes in climate.
613
00:33:41,219 --> 00:33:43,120
With each glacial period,
614
00:33:43,154 --> 00:33:46,189
the ice sheets grow
at the expense of the oceans;
615
00:33:46,224 --> 00:33:49,593
the world sea level falls
by more than 400 feet,
616
00:33:49,627 --> 00:33:51,628
uncovering wide areas of land
617
00:33:51,662 --> 00:33:53,697
along the edges
of the continents.
618
00:33:53,731 --> 00:33:57,033
15 to 25,000 years ago,
619
00:33:57,068 --> 00:33:59,336
there was a period
when the ice receded,
620
00:33:59,370 --> 00:34:01,805
exposing a temporary
land bridge.
621
00:34:01,839 --> 00:34:05,208
The gateway to the other half
of the planet swings open.
622
00:34:05,243 --> 00:34:07,944
Bands of wanderers
crossed the land bridge
623
00:34:07,979 --> 00:34:10,680
to North America
and parts south.
624
00:34:10,715 --> 00:34:14,050
About 10,000 years ago,
the manic swings
625
00:34:14,085 --> 00:34:17,454
of the climate and sea levels
came to a stop.
626
00:34:17,488 --> 00:34:21,091
A new and gentler
climate age began.
627
00:34:21,192 --> 00:34:24,227
It's the one we live in now.
628
00:34:24,262 --> 00:34:26,129
When the great
ice sheets melted,
629
00:34:26,164 --> 00:34:28,298
the sea rose
to its present height
630
00:34:28,332 --> 00:34:31,685
and the rivers carried silt
from the highlands
631
00:34:31,736 --> 00:34:35,205
to build great delta plains
where they met the sea.
632
00:34:35,239 --> 00:34:39,042
On those fertile plains,
we learned a new way of life:
633
00:34:39,076 --> 00:34:43,079
how to grow things,
to feed ourselves and more.
634
00:34:43,114 --> 00:34:45,582
For most of us,
this meant an end
635
00:34:45,616 --> 00:34:47,951
to a million years
of wandering.
636
00:34:49,787 --> 00:34:51,888
The way the planets tug
at each other,
637
00:34:51,923 --> 00:34:54,157
the way the skin
of the Earth moves,
638
00:34:54,192 --> 00:34:56,526
the way those motions
affect climate
639
00:34:56,561 --> 00:34:59,362
and the evolution of life
and intelligence--
640
00:34:59,364 --> 00:35:02,098
they all combined
to give us the means
641
00:35:02,133 --> 00:35:04,367
to turn the mud
of those river deltas
642
00:35:04,402 --> 00:35:07,938
into the first civilizations.
643
00:35:07,972 --> 00:35:11,274
There's nothing like
an interglacial period,
644
00:35:11,309 --> 00:35:14,244
one of those balmy
intermissions in an ice age.
645
00:35:14,278 --> 00:35:17,714
And the great news is that
this one is due to last
646
00:35:17,748 --> 00:35:21,284
for another 50,000 years.
647
00:35:22,920 --> 00:35:26,122
What a break for our kind.
648
00:35:26,157 --> 00:35:28,625
Just one problem.
649
00:35:28,659 --> 00:35:30,594
We can't seem to stop
burning up all those
650
00:35:30,628 --> 00:35:34,130
buried trees from way back
in the Carboniferous Age,
651
00:35:34,165 --> 00:35:35,599
in the form of coal;
652
00:35:35,633 --> 00:35:38,068
and the remains
of ancient plankton,
653
00:35:38,102 --> 00:35:41,137
in the form of oil and gas.
654
00:35:42,907 --> 00:35:45,859
If we could, we'd be
home free, climate-wise.
655
00:35:45,910 --> 00:35:49,479
Instead, we're dumping carbon
dioxide into the atmosphere
656
00:35:49,514 --> 00:35:51,464
at a rate
the Earth hasn't seen
657
00:35:51,516 --> 00:35:53,817
since the great climate
catastrophes of the past,
658
00:35:53,819 --> 00:35:57,554
the ones that led
to mass extinctions.
659
00:35:57,588 --> 00:36:01,157
We just can't seem to break our
addiction to the kinds of fuel
660
00:36:01,192 --> 00:36:04,895
that'll bring back a climate
last seen by the dinosaurs;
661
00:36:04,929 --> 00:36:08,265
a climate that will drown our
coastal cities and wreak havoc
662
00:36:08,299 --> 00:36:13,236
on the environment and our
ability to feed ourselves.
663
00:36:13,304 --> 00:36:16,139
All the while,
the glorious sun
664
00:36:16,173 --> 00:36:19,208
pours immaculate,
free energy down upon us;
665
00:36:19,210 --> 00:36:22,012
more than we will ever need.
666
00:36:22,046 --> 00:36:24,781
Why can't we summon
the ingenuity and courage
667
00:36:24,815 --> 00:36:27,083
of the generations
that came before us?
668
00:36:27,118 --> 00:36:30,954
The dinosaurs never saw
that asteroid coming.
669
00:36:30,988 --> 00:36:33,323
What's our excuse?
670
00:36:43,234 --> 00:36:44,935
There's a corridor
671
00:36:44,969 --> 00:36:47,203
in the Halls of Extinction
that is, right now,
672
00:36:47,238 --> 00:36:49,472
empty and unmarked.
673
00:36:49,507 --> 00:36:54,210
The autobiography of the Earth
is still being written.
674
00:36:54,245 --> 00:36:58,848
There's a chance that the end
of our story lies in there.
675
00:37:05,406 --> 00:37:07,340
DEGRASSE TYSON:
Congratulations.
676
00:37:07,342 --> 00:37:10,543
You're alive.
677
00:37:10,545 --> 00:37:13,346
There's an unbroken thread
that stretches across
678
00:37:13,348 --> 00:37:15,749
more than three billion years
679
00:37:15,751 --> 00:37:18,718
that connects us
to the first life
680
00:37:18,720 --> 00:37:21,922
that ever touched this world.
681
00:37:21,924 --> 00:37:25,325
Think of how tough,
resourceful and lucky
682
00:37:25,327 --> 00:37:27,594
all of our countless
ancestors must have been
683
00:37:27,596 --> 00:37:29,462
to survive long enough
684
00:37:29,464 --> 00:37:32,699
to pass on the message
of life to the next
685
00:37:32,701 --> 00:37:36,102
and the next...
686
00:37:36,104 --> 00:37:38,638
and the next generation,
687
00:37:38,640 --> 00:37:41,541
hundreds of millions
of times...
688
00:37:46,647 --> 00:37:48,315
...before it came to us.
689
00:37:52,320 --> 00:37:54,654
There were so many
rivers to cross,
690
00:37:54,656 --> 00:37:56,256
so many hazards along the way.
691
00:37:56,258 --> 00:37:59,392
Predators, starvation, disease,
692
00:37:59,394 --> 00:38:02,562
miscalculation, long winters,
693
00:38:02,564 --> 00:38:04,965
drought, flood and violence.
694
00:38:04,967 --> 00:38:07,334
Not to mention
the occasional upheavals that
695
00:38:07,336 --> 00:38:10,503
erupted from within our planet
and the apocalyptic bolts
696
00:38:10,505 --> 00:38:13,707
that come from the blue.
No matter where we hail from
697
00:38:13,709 --> 00:38:16,843
or who our parents were,
we are descended
698
00:38:16,845 --> 00:38:20,013
from the hearty survivors
of unimaginable catastrophes.
699
00:38:20,015 --> 00:38:23,984
Each of us is a runner in
the longest and most dangerous
700
00:38:23,986 --> 00:38:26,419
relay race there ever was,
701
00:38:26,421 --> 00:38:30,290
and at this moment, we hold
the baton in our hands.
702
00:38:35,296 --> 00:38:39,632
The past is another planet.
703
00:38:39,634 --> 00:38:42,168
And so is the future.
704
00:38:42,170 --> 00:38:45,705
Some 250 million years from now,
705
00:38:45,707 --> 00:38:47,907
many geologists think
that the lands of the Earth
706
00:38:47,909 --> 00:38:50,610
will be united once again.
707
00:39:05,026 --> 00:39:07,160
All this beauty
will have vanished
708
00:39:07,162 --> 00:39:09,295
and the Earth
of our moment in time
709
00:39:09,297 --> 00:39:13,366
will take its place
among the lost worlds.
710
00:39:13,368 --> 00:39:16,036
The great internal engine
of plate tectonics
711
00:39:16,038 --> 00:39:18,071
is indifferent to life,
712
00:39:18,073 --> 00:39:21,007
as are the small changes
in the Earth's orbit and tilt
713
00:39:21,009 --> 00:39:22,909
and the occasional collisions
714
00:39:22,911 --> 00:39:26,046
with little worlds
on rogue orbits.
715
00:39:26,048 --> 00:39:29,015
These processes have no notion
of what has been going on
716
00:39:29,017 --> 00:39:31,551
over billions of years
on our planet's surface.
717
00:39:31,553 --> 00:39:34,587
They do not care.
718
00:39:34,589 --> 00:39:37,757
Each of us is a tiny being
719
00:39:37,759 --> 00:39:40,527
riding on the outermost skin
of one of the smaller planets
720
00:39:40,529 --> 00:39:43,763
for a few dozen trips
around the local star.
721
00:39:46,567 --> 00:39:49,202
The things that live
the longest on Earth
722
00:39:49,204 --> 00:39:51,004
endure for only
about a millionth
723
00:39:51,006 --> 00:39:53,273
of the age of our planet.
724
00:39:53,275 --> 00:39:55,341
So, of course,
the individual organisms
725
00:39:55,343 --> 00:39:57,877
see nothing of
the overall pattern.
726
00:39:57,879 --> 00:40:00,914
Of changing continents...
727
00:40:00,916 --> 00:40:03,416
climate...
728
00:40:03,418 --> 00:40:05,452
evolution.
729
00:40:05,454 --> 00:40:08,421
That we understand
even a little of our origins
730
00:40:08,423 --> 00:40:12,692
is one of the great triumphs
of human insight and courage.
731
00:40:12,694 --> 00:40:16,463
Who we are and why we are here
can only be glimpsed
732
00:40:16,465 --> 00:40:19,399
by piecing together
something of the full picture,
733
00:40:19,401 --> 00:40:23,403
which must encompass
eons of time...
734
00:40:23,405 --> 00:40:26,139
millions of species...
735
00:40:29,310 --> 00:40:31,878
...and a multitude of worlds.
736
00:40:38,886 --> 00:40:41,788
In this perspective,
it's not surprising
737
00:40:41,790 --> 00:40:43,890
that we're a mystery
to ourselves and that,
738
00:40:43,892 --> 00:40:46,326
despite our
manifest pretension,
739
00:40:46,328 --> 00:40:49,395
we are far from being masters
of our own little house.
740
00:40:55,302 --> 00:40:58,271
This new corridor
has no name above the entrance
741
00:40:58,273 --> 00:41:01,207
to designate its epoch,
and we don't yet know
742
00:41:01,209 --> 00:41:05,578
which failed species will be
memorialized within its walls.
743
00:41:05,580 --> 00:41:10,283
What happens here, in countless
ways, both large and small,
744
00:41:10,285 --> 00:41:12,652
is being written by us.
745
00:41:12,654 --> 00:41:14,954
Right now.
746
00:41:21,162 --> 00:41:14,954
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