All language subtitles for History.of.the.World.in.Two.Hours.2011-eng

What if we could tell you everything,
the entire history of the world?

Now, what if we told you
we could do it in just two hours?

We're going to tell the whole story,
from the big bang to the present day.

How the planet prepared
for the rise of man.

How the stone age
led to the steam engine.

How the first seeds sprouted
into cities and civilizations.

Everything is connected,
and the path leads to you.

It took history 13.7 billion years
to unfold.

We'll show you everything you
need to know in the next two hours.

This is our infant universe.

Everything that will ever exist,
everything that will ever happen,

all begins here,

within this tiny bundle of energy,
smaller than an atom.

And right now, history as we know it
is about to mysteriously begin.

For reasons we may never know,
our universe suddenly erupts.

In a millionth of a millionth
of a millionth of a millionth

of a millionth
of a millionth of a second,

it went from a size
smaller than an atom

to bigger than a galaxy.

What you're seeing is energy,

and it's one key to understanding

everything that will unfold
in the next two hours.

Within a fraction of a second,

the big bang creates
all the energy that will ever exist,

all the energy
that will power the stars,

that will fuel
anything that ever lives.

All the energy
that you will ever consume

dates back to the beginning of time.

When you put gas into your car,

you're tapping energy
that was created during the big bang.

You're tapping
the energy of the universe itself.

We're only a few minutes into
our two-hour journey,

but already 380,000 years have passed.

You are about to witness
the birth of your original ancestors,

the first atoms.

This is hydrogen.

The universe will use it to make
everything in the world around us.

Hydrogen is like a baseball team.

You say, "what player do I want
to start my team with?"

Well, if I want to start a universe,
i want to start it with hydrogen.

Because from that, with a lot of heat
and a lot of pressure,

you can build more kinds of atoms.

The first atoms
blast through the early universe.

And luckily for us,
they don't spread out evenly,

because in those tiny pockets
with more atoms,

gravity, the great sculptor
of the early universe,

begins to work its magic.

The first galaxies
are beginning to form,

revealing a timeless secret
of the universe.

Throughout history,

whenever more matter and energy
can be drawn together in one place,

more complex things can emerge.

We have all of these urban centers
around the planet

where so much creativity, so much art,
so much science,

so much culture came about

because of all these opportunities for
things to interact with each other.

Really, in a sense, where
there is stuff, new stuff can develop.

And where there isn't anything,
nothing much can develop.

300 million years after the big bang,

inside of forming galaxies,

gravity continues to squeeze together
clouds of gas and dust,

causing pressure and heat
to violently rise.

When the temperature reaches
18 million degrees fahrenheit,

hydrogen atoms slam together,
creating a new element, helium,

and radiating bursts of energy.

The first stars are born.

Suddenly there were
these new beacons of light

shining forth,
pouring energy into the universe.

Let there be light.

But something is missing
from this early universe.

There are billions of stars,
yet not a single planet.

To form planets and eventually people,

to take the next leap that would
make all of history possible,

the universe needs more to work with
than just hydrogen and helium.

The complicated elements,

the heavier things
that we build stuff out of,

for example, iron or life built out
of carbon and things like that,

they're actually
manufactured in stars.

We may see stars like our own sun
as sources of light,

but there is something bigger
happening deep inside.

Stars are element factories.

They fuse hydrogen into helium,
helium into lithium,

forging 25 of the most common elements
we'll need to live,

including carbon, oxygen,
nitrogen, and iron.

So more than 12 billion years ago,

stars are already creating the element
that will spur the iron age,

allow for the building of cities

and the creation of some of mankind's
most famous monuments.

But a look at the statue of Liberty

reveals the next challenge
awaiting the early universe.

While the statue's frame is iron,

her skin requires an element
too heavy to be made in stars.

For lady Liberty to have
material for her skin,

for there to be
gold for wedding rings,

or uranium for nuclear reactors,

some elements had
to be created another way.

Stars don't have
enough energy to do the job,

but if the element factory
isn't powerful enough,

how about blowing up the factory?

Just a few million years
after the first stars formed,

some of them exploded.

These explosions, known as supernovas,

are the biggest blasts in the universe
since the big bang,

providing the extra boost of energy
needed to fuse heavier elements.

In the fiery blast
of their own destruction,

stars create uranium, gold,

all the rest of the elements that will
fill our world, including copper.

The periodic table of the elements

is sort of the library
of matter in the universe.

Those are your building blocks,

everything that is coming out of
that particular chemistry set.

Supernovas are absolutely necessary
for us to be here.

You know, we have iron in our blood.

We have little bits of old supernova,
therefore,

just floating around through us.

We are all stardust.

Copper and tin, bronze age.

Without supernovas,
there's no bronze age.

Go to any supermarket
and buy a multivitamin

and go and look in the ingredients.

You'll find copper. You'll find zinc.
You'll find selenium.

You'll find all sorts of elements
that can only be made in a supernova.

The elements made by stars
will become the seeds of life on earth

and the drivers of human history.

But the journey has just begun.

Before there can be life, the universe
has to build us a suitable home.

To build a proper house, you have to
assemble the right materials

all in one place.

Now when planets form,
it's the same thing,

it's the materials
that you have at hand

that's gonna dictate the kind of house
that your planet's gonna be.

To get enough of the right material
in the right place all at once

takes a very long time.

Over the next eight billion years,

more than half of history
as we know it,

the element factories
continue their work.

Stars explode and are reborn,

each generation with
more heavy elements than the last.

Until 4.6 billion years ago.

Finally there are
enough materials gathered

for the next step on the path to us.

A new star is born.

This is our sun.

It's so massive that it's gathered up

99.9% of the gas and dust
in the solar system,

but there's still
just enough left behind

for gravity to build
some other things,

like planets.

The third one out from this star
will be our home.

By the time earth emerges just over
four and a half billion years ago,

two-thirds of the history
of the universe has already passed.

The first sunrises sweep
across a foreboding alien planet,

a world spinning so rapidly
that a day lasts only six hours.

When you go back to the early earth,
right after the planet formed,

you really have to think
of the earth as another planet.

The sun would have looked out
over a hellacious scene

of just molten lava.

And in places you would
see rafts of black volcanic rock.

Within the liquefied rock
the elements are all in a jumble.

Something has to
bring order out of this chaos.

And once again
that something is gravity.

Lighter material
drifts toward the surface

and forms a solid crust,

while heavier material
sinks toward the center,

forming a molten iron-nickel core.

This churning liquid metal

creates a magnetic field
that reaches out into space.

Like a force field,
it will protect our future home

from the sun's
deadly charged particles.

Soon this magnetic field
will allow for life to grow,

and later, guide the explorers who
will connect two halves of the world.

But for all this to unfold, the earth
will need a critical partner.

Four and a half billion years ago,

an object the size of Mars
smashes into the planet

at 25,000 miles per hour.

Earth swallows up
much of the impactor.

But a spray of molten debris
is whipped off into space.

Within as little as a year,
gravity gathers this debris

into a secondary sphere
in orbit around the earth,

where it has been ever since.

The formation of the moon

was an incredibly important event
in earth's history.

And in fact, its creation,
over four billion years ago,

is really important to
the earth's climate today.

The moon keeps earth steady.

Its gravitational pull
prevents the planet from wobbling,

saving us from wild climate swings.

And the collision that formed the moon
leaves earth tilted on its axis,

giving the planet
a key ingredient to life,

seasons.

Having seasons is very, very important

for the evolution of life
on the earth,

and having some stability
in the tilt of those axes,

that's very, very important also
for maintaining life on the earth.

The moon's gravity
also begins to slow earth's rotation,

which will eventually lengthen
our days from six hours to 24.

4.4 billion years ago.

It's too hot on earth
for liquid water to exist,

but there's water vapor,
steam in the atmosphere.

The trick is
how to get it out of the sky.

Onto any world where you hope
to have life, a little rain must fall.

For millions of years
as the planet cools, rain pours down,

forming puddles, lakes,
and eventually our oceans.

By 3.8 billion years ago,

our planet has a moon
and permanent oceans,

but it hardly resembles
the place we now call home.

To become the stage
for all of human history,

earth needs an oxygen-rich atmosphere,

fertile continents
for people to discover and develop.

Who will create our modern world?

There's a trillion of them
crawling on your skin right now.

We're telling the history of the world
in two hours,

from the big bang to the present day.

And our modern world
holds important clues to the story.

In fact, structures like this

hide a mysterious link
to the first life on earth.

3.8 billion years ago,

beneath the surface
of our primeval oceans,

a revolution is taking place.

Six simple elements,
including hydrogen from the big bang,

and oxygen, carbon,
and nitrogen created by stars,

have combined
to form the key substances

that will make up all life,
including us.

The most spectacular is DNA.

Within its spirals
hide the secret codes of life.

700,000 years
after the planet first formed,

life on earth begins.

We stand
not on the shoulders of giants,

but of tiny organisms, bacteria.

We're very egocentric. We think
that we animals run the world,

but in fact we are very late entrants.

It was an empire of bacteria
long before animals.

Animals come along,

and we like to think
that we wiped out that empire.

Well, we would be dead
if we wiped out that empire.

I have within me
an entire zoo of bacteria.

In fact, each one of us

has more bacteria living in our bodies
than there are people on the planet.

For billions of years,

microbes like these
will have earth to themselves.

Like our infant universe,

the first life is small, simple,
and full of possibilities.

The secret of how it explodes

into all of the incredible forms
we see today, including us,

goes back to the beginning of time.

As we've seen,

all the energy that will ever exist
was created in the big bang.

All creatures need to grab their share
of this energy to survive.

The more we harness,
the more efficiently we use it,

the more complex we can become.

And almost all of our share
of the big bang's energy

is beamed to us by the sun.

Two and a half billion years ago,

some very special bacteria

figure out how to
consume the sun's energy to live.

In doing this, they also create

the most important waste product
in the history of the world,

oxygen.

Soon, oxygen will remake our world,

but first,
it has another important job to do.

Earth's ancient seas
are full of iron particles,

and everyone knows
what happens when oxygen meets iron.

Here I'm a little bacterium.
I've produced this oxygen molecule,

and here's a big piece
of iron and clump, I rust it.

The rusted iron
collects on the sea floor.

Billions of years later,
these huge deposits will be raised up

to become major sources
of the world's iron and steel.

It was these iron deposits

that later on
drove the industrial revolution.

In this way, the Brooklyn bridge

and the other early landmarks
of the industrial age

are a direct link to
some of the first life forms on earth.

Once there's no more iron
left in the sea to rust,

these ancient bacteria
have a mission to complete.

They create so much oxygen

that it fills the oceans
and escapes into the atmosphere.

And from then on
we have a very different planet

from all the other planets
in the solar system.

Now, life takes a giant leap.

For the first time,
some bacteria learn to live on oxygen.

Every human breath is a ritual
two and a half billion years old.

Life tends to stick with what works

even over the course of
billions of years.

Oxygen is a game changer.

By taming its power,

life has found
a better way to energize itself.

Twenty times more efficient
than anything used on earth before.

What life does
with all this new energy

will be the story that leads to us.

Over the next two billion years,
life becomes more complex.

Skies become blue,

and so do the oceans
that reflect them.

Large, solid continents appear.

Earth is beginning to look
more like the place we now call home.

550 million years ago,

as the planet celebrates
its four billionth birthday,

oxygen levels in the atmosphere have
risen from next to nothing

to as much as 13%.

Take a deep breath,

because life on earth
is about to go wild.

This is the cambrian explosion,
biology's version of the big bang.

Right after you have abundant oxygen,
you get size and complexity.

And oxygen lets you do that.

It's in this breathtaking span
of roughly 30 million years

that most of the
major animal groups evolve.

By 500 million years ago, the first
bony fish have evolved in the seas.

These fish are our direct ancestors.

Though they look nothing like us,

they evolve the body parts that will
make our own bodies possible,

including a spine,
and a mouth with jaws and teeth.

We owe a great deal
to our fish ancestors.

In fact, all vertebrates today

really represent modifications
of the original fish body plan.

For the first four billion years
of earth's history,

plants and animals
have stuck to the seas.

But that all begins to change.

With oxygen comes an ozone layer,

protecting us from
dangerous radiation.

Plants make the move first.

Around 400 million years ago,
animals are ready to take the leap.

Among the first ashore
are the amphibians,

whose descendants will include us.

The most amazing thing about animal
evolution ever, for me personally,

is that moment that first amphibian

walks out of the primeval ocean
onto land

and takes a big gulp of air.

Kind of like great-great-great-
great-great-great grandpa

coming out of the ocean
and seeing this fantastic world.

And it's like, "hey! I can live here.

"Look at those trees.
Look at those bugs.

"There's food here. I can do this."

Eventually, humans will conquer
every imaginable terrain.

But before we can do that,

our ancestors must first cut their
final tie to the water,

mating season.

Like modern frogs,

they have jelly-like eggs
that would dry out on land.

But some amphibians
eventually solve the problem.

They evolve a new form of egg

with a shell
that keeps the moisture in.

This allows us
to carry the ocean with us onto land

and signals the evolution
of amphibians into reptiles.

You could be 300, 400, 500,
1,000 miles away from water

and still have the water in that egg
in order to birth.

That is the key.

It cuts that final tie to the ocean.

That way we could colonize
the rest of the land.

300 million years ago, life flourishes
in massive tropical swamps

where planet earth
is cooking up a surprise.

As plants die here,

they are buried, compacted,
and cooked.

Energy created in the big bang

and radiated by the sun
to plants on earth

is now locked away underground
as coal,

a gift to be opened by human beings
millions of years in the future.

250 million years ago,

an apocalypse unfolds.

The biggest spike in volcanic activity
since the early days of the planet.

The atmosphere is choked
with carbon dioxide,

and the diversity of animal life
spawned in the cambrian explosion

is stopped dead in its tracks.

More than 70% of all species on earth
go extinct

in the worst mass die-off in history,
the permian extinction.

Extinction is a recurring character
in the story of planet earth.

Five times
in the last 500 million years,

some cataclysm
wiped out the dominant species.

It's a reshuffling of the deck that
allows new creatures to take hold.

New creatures like the dinosaurs.

Dinosaurs will reign
for the next 160 million years.

During that time,
the first hardwood forests appear.

And after
more than four billion years,

the moon's gravity finally settles
earth into a 24-hour day.

At the start of the dinosaur era,

the continents are clustered together

into a single landmass
we call pangaea.

But now they start to break apart.

Africa separates from south America.

The vast Atlantic ocean opens up,

creating what will become one of the
defining barriers of human history,

the Gulf
between the old and new worlds.

The undisputed stars
of the dinosaur era

are animals like triceratops
and t-Rex.

But there are some important creatures
scurrying around their feet.

If we were to trace our lineage back
far enough,

we would come to really small
shrew-like mammals

surrounded by
these titans of reptile life.

During that time, mammals,
we were living on the fringes.

We were maybe stealing dinosaur eggs,
maybe just eking out an existence.

So the dinosaurs kind of held us back.

The biggest headline of the history
of dinosaurs,

which is 160 million years,
is that we lost!

Mammals lost.

We couldn't get much bigger
than a small cat.

For 160 million years,
all the medium-size, medium-big,

big, gigantic and stupendous animals
were dinosaurs, for that whole time!

They beat us fair and square.

But the deck
is about to be reshuffled.

Sixty-five million years ago,

a six-mile wide object,
likely an asteroid,

slams into the earth.

A dust cloud blocks out the sun.

Temperatures plummet.

Every creature on land
weighing over 50 pounds goes extinct.

The reign of the dinosaurs is over.

The greatest gift that the dinosaurs
ever gave us was dying.

When they went extinct,
it gave the mammals time to rise.

It doesn't take long after
the disappearance of the dinosaurs

for the first true primates to appear.

Like their later versions,
including us,

these mammals have evolved
forward-facing eyes

allowing for accurate depth perception
and flexible hands with five digits.

They have five fingers, just like us,
which means we can grasp things.

If you think about other animals
that don't have digits

organized the way ours are,
their ability to hold things,

to manipulate objects,
is much more limited.

Fifty million years ago,

our primate ancestors are evolving
on a planet that is warming.

It's so hot,
there are jungles at the poles.

As the continents drift,

the americas and Africa
have almost fully taken shape.

But in northern Africa,

modern-day Egypt
is submerged beneath an ancient sea.

On the floor of that sea live small,
shelled creatures called nummulites.

Their shells,
made of calcium and carbon,

pile up on the sea bottom
over millions of years,

where they form into limestone.

Limestone that will be used
to build the great pyramids.

If you look closely
at the pyramids today,

you can still see evidence that
these 4,000-year-old monuments

are in fact made of
50-million-year-old seashells.

By 10 million years ago,

earth is morphing into a world
most of us would recognize.

The Colorado river
is carving out the Grand Canyon.

Mountain ranges
like the himalayas have arisen.

They're so tall,
they disrupt weather patterns

setting the stage for a colder planet.

The isthmus of Panama emerges
to connect north and south America,

cleaving the connection between
the Atlantic and the pacific,

disrupting ocean currents

and tipping the world
even more towards an ice age.

With the planet getting colder,

our primate ancestors
hang on in the tropics,

but a new creature is coming in
that threatens to destroy them.

Seven million years ago,

our primate ancestors
live safely in the trees.

But their neighborhood
is about to be invaded.

This newcomer will have
as profound an effect on human history

as any other living thing on earth.

It seems almost impossible to believe,

but one of the most important things
that will lead to the emergence of us,

is the emergence of grass.

The grasslands appear almost
simultaneously around the world.

We get the African savannas,

we get the eurasian steppe lands,

we get the north American prairies,

we get the great grasslands
of Argentina,

appearing simultaneously
around the world.

In eastern Africa, grasslands invade
the traditional woodland habitat

of our ape ancestors.

With fewer trees
and greater gaps between them,

our ancestors have to adapt.

Apes would notice that there's more
and more apes in the same tree

and less and less food,

increasing incentives for apes

to go from one patch of food
to a different one,

separated by grasslands.

Now, one way to do it
is to run like hell, you know.

The other way to do it is to extend
one's food sources into the grasslands

to seek out the foods
that are available there.

And so, some apes make the move down
into this stark, new habitat.

It's a landscape better suited
to primates that can walk on two legs.

Keeping their heads up above the tall
grasses to watch for predators.

Standing on two feet
is a revolutionary advance.

Because it frees up our hands.

Hands we will need
to shape human history.

2.6 million years ago,

early proto-humans or hominids

walk an earth whose rocks are
loaded with the element silicon.

Created in the cores of stars
billions of years before,

silicon is the second-most
abundant element in earth's crust.

One of its chemical quirks
is the ability to bond with oxygen

to form crystals
that combine into solid rocks,

rocks that can be chipped
and shaped without shattering.

Hominids started doing this
2.6 million years ago,

breaking cryptocrystalline silicates
to make sharp edges,

and people use them for millions,
literally 2.6 million years.

Simply having a modified stone
with a sharp edge on it,

now suddenly you have a hammer.

You have a crude cutting edge.

A simple modified stone means
a human can suddenly do

a thousand more things
than we could do previously.

That little extra bit of technology

enabled our ancestors to persist
and eventually turn into us.

Silicon launches the first
technological revolution,

the stone age.

Millions of years after it powers
our first handheld devices,

another chemical quirk
of silicon will make it

the height of technology once again.

The next leap towards
becoming truly human

relies on a little-known secret
of our home planet.

In the known universe,

it turns out earth
may have a rare and special power.

Of all the planets and moons
in the solar system,

we think that earth is unique
in the ability to sustain fire.

Other planets and moons
have lightning and lava.

But only on earth do we have
the two critical things

we need for fire to burn,

a vast fuel supply
in the form of plants and trees,

and an atmosphere full of oxygen
to fan the flames.

If fire wasn't a possibility, you'd
have nothing like us running around.

Homo sapiens,
they made a world with fire.

Our ancestors have fire firmly
under control by 800,000 years ago.

It's a skill that connects us
back to the very beginning.

Remember that all energy
was created in the big bang

and all life is in a competition
for our share of this energy.

Using fire to cook is like having

an external stomach
to break down foods,

releasing more calories,
giving us more energy,

which in turn allows us
to support bigger brains.

Fire is also the ultimate
gateway technology.

We will soon use it
to turn Clay into pottery,

metal into weapons,

water into steam power.

If you don't have fire, you can't have
the internal combustion engine.

No fire, no metal.

No fire, no rubber.

It's a technology that opens a world
of possibilities

for creatures that know how to use it.

200,000 years ago,

the modern human
has fully taken shape.

The larynx or voice box

which is high up in the throat
in our ancestors, descends.

More complex sounds are now possible.

We begin to speak.

For the first time,
information can be shared

between individuals
and across generations.

Humans have gained
a critical advantage

over every other creature on earth.

You can tell, "my grandfather said
that when the elephants didn't show up

"we go off and hunted zebras."

You know, "my aunt told me that her
cousin found this water hole

"on the other side of that river."

And we can all benefit

and we can all understand what they
mean when they were describing

what they found out on that landscape.

Language changes humans
from being like stand-alone computers

to being networked computers
where you can share information.

Now, one doesn't need to depend
on one's own personal experience.

One can borrow the personal experience
ofanyone

with whom one can communicate.

That's a powerful advantage.

No other creature has that.

As a species,
humans become exponentially smarter.

The global game board has been set,
and we are now ready to play.

100,000 years ago, man can move.

We have agile hands
and primitive tools.

We can communicate and control fire.

We are finally ready to expand
out of our African home

on a path
millions of years in the making.

Shifting continents have linked Africa
and eurasia

into the largest contiguous landmass
on earth, afro-eurasia.

33 million square miles,

more than twice the surface area
of our entire moon.

For early humans,

this means more than half the land
on earth can be reached on foot.

Human dispersal
was a crucial game changer.

We are one of the few primates

that live on more than
one continent simultaneously.

So what that means is that
we're better insulated

from the kinds of things that caused
big mammals to become extinct

than other primates are.

It's extinction insurance.
Dispersal is extinction insurance.

But just as the world
begins to open itself up to man,

the planet turns on us.

An ice age begins.

Now the planet will test us
like never before.

By 50,000 years ago, glaciers begin
to advance down from the north pole.

At the same time, humans continue
their conquest of the globe,

arriving in China and Australia.

By 30,000 years ago, homo sapiens
reach Europe for the first time.

By 20,000 years ago, with the ice
nearing its most extreme,

the march of man reaches the frigid
tundra of northeast Siberia.

Despite the trials of the ice age,

man endures and develops the last
skills we will need to be truly human.

The clues lie in these symbols.

We have taken an intellectual leap,

to think beyond the here and now,

beyond what is simply
needed to survive.

We can only start saying we have
an organism that is human,

that is the same as us,

when we start seeing evidence
of symbolic thought.

It's when we start seeing
a picture of a cow

that everybody will recognize
as the picture of a cow.

Because only when we start seeing
all of those things

can we say that is a human.

People or creatures
that think like us,

that see the world
in the same way as us.

And from that moment on,

human history was marked to be
radically different

to any other species on this planet.

Now, with huge amounts of the planet's
water locked up in ice,

sea levels plummet by 300 to 400 feet.

The last great barrier
to the spread of man is erased.

We come across the Bering land bridge
from Siberia to north America.

We are telling the history
of the world in two hours,

and in just one hour, more than
13 billion years have already passed.

These years of preparation
have allowed man

to finally emerge
and spread out across the planet.

And human history as we know it
can truly begin.

Our history of the world began with
the beginning of time, the big bang.

It has taken us on a journey
of nearly 14 billion years.

Now, as humans take center stage,

it's important to remember

just how small a slice of history
we actually occupy.

To make things simple,

imagine compressing 14 billion years
of history

down to just 14 years.

On this scale, the earth would have
existed only for the past five years.

So that's about a third
of the history of the universe.

Large complex creatures
would have developed seven months ago.

On this scale, dinosaurs went extinct
only about three weeks ago.

The entire recorded history of humans

would span
only the last three minutes.

Modern industrial societies,

the industrial revolution,
effectively, six seconds ago.

What this shows me is that we humans
have been around

for only a very brief instant in
the recorded history of the universe.

Mankind has waited billions of years
for our brief instant to shine,

as the stars and our evolving planet

carried out the slow work
of organizing the elements

in a way that would
make human history possible.

It's 10,000 b.C.,

less than 100,000 years
after expanding out of Africa,

man has reached south America.

Humans have met the adversity
of the ice age head on,

and rather than die off,

we have adapted,
become even more intelligent.

And now
we have colonized the entire globe.

From coast to mountaintop,

from tundra to desert,

humans are there.

Our closest living ancestors,
the chimpanzees, live in the tropics.

They only live in the tropics.

Humans have managed to colonize
the entire globe.

Ice age land Bridges allowed man
to spread around the world,

but now the ice begins to melt
and sea levels rise again.

Humans are trapped and separated in
two vast and unconnected hemispheres.

Each pocket of humanity left to make
the best of what it has been given.

As the glaciers recede,

they carve out lakes,
rivers, and bays.

The map as we know it emerges.

In Africa,

increased rainfall causes lake
Victoria and lake Albert to overflow

and form Egypt's nile river.

In eurasia, other rivers emerge,

the tigris and euphrates
in mesopotamia, modern-day Iraq.

The indus in modern-day Pakistan
and China's yellow and yangtze.

These river valleys
become critically important

for how human history will now be
played out

following the retreat
of these ice sheets.

These are the river valleys
whose waters and fertile soils

will allow the first seeds
of civilization to be planted.

With temperatures warming
after the ice age,

plants and animals are more plentiful,

and man can finally
choose to stop moving.

Permanent settlements begin.

Populations grow.

With more mouths to feed,
our ancestors have to get clever.

They had to find a way
to increase the amount of food

they could get from the surroundings.

Now, one discovery forever changes
the planet and the path of mankind.

We learn to plant seeds.

And the seeds we sow
come from the same plants

that millions of years earlier
spurred our evolution from ape to man,

the unheralded hero
of human history, grass.

A grass seed is tiny, right?
It's no food.

I can hunt a bison
or I can take grass.

You hunt a bison, right?

Ironically, grass seeds
become the most important food crops

in the world, but they're the things
that are ignored by hunter-gatherers

for thousands and thousands of years.

People don't start using them until
they absolutely have to use them.

Some of the species of grass
that we are most familiar with

includes sugarcane.

It includes wheat and rye and barley,

all of the cereal crops
are types of grass.

So it's not just
that beautiful green lawn

that we measure
our middle class success from.

It's also the staple crop
upon which civilization depends.

It is the majority
of our calorie intake.

Once again,
it all goes back to the big bang.

Central to the story of all life
is our competition for that energy

created at the beginning of time.

Just as oxygen gave us an edge,

just as fire allowed us
to consume more calories,

switching to farming
is an energy revolution.

A hunter-gatherer
needs 10 square miles of territory

to provide himself
with enough sustenance,

enough energy in the form of
plants and meat to survive.

A farmer can harvest the sun's energy
so efficiently,

he can fulfill his needs using
only a tenth of a square mile of land.

In the warming after the last ice age,
farming begins to take hold

in a half dozen places
around the globe,

but by the fortunes of geography,
no place in the ancient world

has a better concentration
of plants and animals

that can be domesticated

than the middle east's
fertile Crescent.

In the middle east,
we have this remarkable convergence

of species
that seem to have been susceptible

to domestication,
both plants and animals.

In terms of animals, we're talking
about cattle, pigs, sheep, and goats.

In terms of plants, two varieties
of wheat, rye, barley, lentils, figs,

all in this very small part
of the world.

Unlike the fertile Crescent
and the rest of afro-eurasia,

places like sub-saharan Africa
and the americas

have very few wild species
that can be easily domesticated.

It's a critical difference.

People blessed with the right mix
of plants and animals

will become more powerful

and get a massive head start
on the road to the modern world.

One animal that gives any human
who can tame it

an almost unbeatable edge
is the horse.

It's a little-known fact that although
horses first evolved in the americas,

they died out there
along with many other large mammals

around 10,000 b.C.

There were at least three species
of ice age horses in north America,

maybe more, some as small as ponies,
some as big as clydesdales.

And they had evolved in north America
for 40 million years.

They're part of the whole history, and
then... they're gone. They're gone.

These powerful potential allies

disappear before they can be used
by the first north Americans.

Fortunately before that happened,

large numbers of horses escaped back
across the Bering strait land bridge

and spread out
across the great grasslands

and steppe lands of central eurasia.

A narrow escape that had
a profound effect on human history.

Around 4,000 b.C.,

nomadic people in central Asia
learn to tame them for the first time.

Domesticated horses will be harnessed
across eurasia,

advancing everything
from work to warfare.

Perhaps no other animal
has had a bigger influence

on the course of human history.

And the circle wouldn't be complete
for another 5,000 years

when Christopher Columbus
would bring horses with him

on his second voyage to the americas.

His horses would be the first
to set hooves in the americas

since the great die-off
over 10,000 years earlier.

6,000 years ago,
domestication of animals and plants

sets the stage for the next phase
of human history.

Like clouds of interstellar dust
gathering in material to form stars,

a type of gravity is at work
as places like sumeria,

located in part of the
fertile Crescent known as mesopotamia,

draw in people,
support large populations,

and spin up into centers of power
andinnovafion.

By 3,0005.0.,

some of these sumerian settlements
can truly be called our first cities.

One of them, uruk,
has around 50,000 people

living in less than one square mile,

a population density
that rivals modern-day New York City.

Humans have become so efficient
at deriving energy

from domesticated food
that this land area,

which would have supported
only a single hunter-gatherer,

now can support thousands.

But a change in diet
also triggers a new dependence.

Once you move to agriculture,

you are depending for 80, 90%
of your calories

on perhaps one or two species.

In the case of the middle east,
wheat and barley.

In the case of wheat and barley,

they both ripen
at about the same time.

Humans have to gather the seeds
at the same time.

So now we have our food for the year
that has arrived in one hit.

It's like getting your salary
paid once a year.

You need to record it.
You need to plan,

because if inevitably your crop fails,
you have famine.

And you're not gonna have another go
for another 12 months.

In these first cities, crops are king.

To keep track of them,

our ancestors
develop the first writing.

To protect them, the first armies.

And to administer them,
the beginnings of politics.

When you have hundreds or thousands
of people who are living together,

there's simply too many people

to sort of run around
and create a census.

It creates a need for government.

It creates a need for some form of
social and political hierarchy.

Planting seeds has set man
on a new path.

Settlements have grown into cities.

But to take the next epic step
from city to civilization,

we'll need the help
of a very surprising creature.

5,000 years ago,

after wandering the earth
for more than 100,000 years,

mankind has begun to settle down.

We cluster near rivers,
along the tigris and euphrates,

the nile, the indus,

the yellow and yangtze.

Civilizations are about to take off.

But first,
they must all master one thing, trade.

The more they exchange goods
and learn from other lands,

the faster they grow.

It seems that long-distance trade
and communication

is a necessary precursor

to allow urban civilization
as we know it.

And surprisingly,
the first civilizations arise

on the back of a creature

with a lowly reputation
in the modern world, the donkey.

The donkey caravan
is the interstate highway

and high-speed Internet of its day.

Their routes will lay the groundwork
for the modern world,

moving not only goods like timber
and bronze, but ideas and stories.

The civilizations they connect

will be some of the first
described in the Bible.

The caravan routes
converge at the persian Gulf,

where they link up with ships
that carry goods to India.

It essentially
brought these civilizations together

into great cultural
and material exchange

and really was the beginning
of the trend towards globalization.

It is a key to understanding
how our world works to this day.

Just like the first civilizations,
we trade and form networks.

These networks form hubs.

And throughout history, being at
that hub has meant one thing.

The amount of ideas, the amount
of cargo that passes through a region,

seems to have a direct correlation

to how powerful
and important they are.

By 2,000 b.C.,
humans have gone from humble huts

to massive monuments.

In Africa, great pyramids arise
on the banks of the nile.

The first stages of stonehenge
rise up in ancient britain.

And back in sumeria, artificial temple
mounds called ziggurats

climb ever higher toward the heavens.

To cement these massive
structures together,

the builders of sumeria turn to a
substance that oozes from seepages

along the euphrates river.

It's called bitumen.
Used as asphalt in the modern world,

it's the first petroleum product
to be exploited by mankind.

While bitumen is highly prized,

the lighter, thinner, substance oozing
from the ground along with it

is considered a nuisance
by the ancients

because it catches fire so easily.

The ancients call it naphtha.
We call it gasoline.

And it's one of the first indications
of the vast oil fields

that will one day
turn the cradle of civilization

into a center of wealth and warfare.

The legacy of these
first civilizations

can be seen in surprising ways.

The sumerian counting system was
based on the number 12

rather than 10, which is why we divide
our days into two 12-hour blocks,

our hours into 60 minutes,
and our minutes into 60 seconds.

The sumerians also likely
invented the wheel,

which eventually leads
to another innovation

that will change the course of man,
the chariot.

Thus bringing together the sumerian
invention of the wheel

with the domestication of the horse

that had occurred
amongst these nomadic peoples

into this really formidable piece
of military technology.

Around 1,200 b.C.,

a chariot-driven
clash of civilizations

cuts off trade routes
for copper and tin,

the metals we need to make
bronze tools and weapons.

But luckily,

the stars have made us
an alternative, iron.

Now, metalsmiths
make a crucial discovery.

By working at higher temperatures,

they can release
the power of this ancient metal.

Easier to sharpen and 700 times more
common on earth than copper,

it is a game changer.

Humanity enters the iron age.

As we reach the first millennium b.C.,
history has taken us on a wild ride.

From the initial blast
of the big bang,

to the formation of earth and its
first creatures and the rise of man,

we've seen the ice age create Bridges
to spread mankind around the world,

then strand us
on different continents,

leaving us to survive
on what we have at hand.

So by 1,000 b.C.,
the world remains a divided place.

The trade network that connects
much of eurasia and north Africa

doesn't yet penetrate
the planet's driest deserts

or cross the vastest oceans.

Cut off by geography are pe0ple

in places like sub-saharan Africa
and the americas.

With few easy to domesticate plants
and animals of their own,

they remain tied
to more ancient ways of life.

600 b.C.

The cavalry have arrived.

Humans ride into battle
on horseback for the first time.

We've seen thatjust taming a horse
gives man a massive advantage.

Now, pairing him with iron weapons
makes him nearly unstoppable.

These advances in technology,

they don't just make a fighting
ability possible,

they make empires possible.

And that is the story of the
next several millennia.

With new technology and improved
logistics, empires spread,

uniting massive land areas
under a central control.

As empires grow,

so do new beliefs.

One interesting phenomenon
we see with the rise of these empires

is this idea of monotheism,

this idea of a universal god that
develops over time,

and it's just a phenomenon.

Judaism emerges, from which we
eventually get christianity and islam.

Buddhism and hinduism also arise.

The five major religions today are all
rooted in this remarkable era.

Although empires spread,
some great powers remain isolated.

The rise of the himalayas
50 million years earlier

has left China cut off from trading
with the rest of the world.

But that is about to change.

Around 100 b.C., a Chinese emperor
sends an envoy to the west

in search of alliances.

The routes he travels
will become the silk roads,

a massive trade network
that connects China

across central Asia
to the Roman empire.

China has joined the world.

As far as we know,
no Chinese trader ever met a Roman.

No Roman ever met a Chinese trader,

at least during this first period
of the silk roads.

But this vast trade
then began to explode.

Between about 100 b.C.
And about 200 a.D.,

we have three centuries of
trade and cultural exchange

on a level that has not
been seen before in human history.

But this new human network
also unleashes

hidden dangers.

By the beginning of the common era,
great empires have risen,

and a massive trading network
connects most of Europe and Asia.

But the trade routes
also carry an invisible threat,

disease.

Massive epidemics that some blame
for taking down both the Roman empire

and China's han dynasty,

but these networks also lead to
the spread of religion.

In 312 a.D., the Roman emperor
constantine converts to christianity,

paving the way for it to become
the dominant religion of Europe

and the west.

Three centuries later,
islam also emerges,

a religion that will, for a time,

unify a territory two and a half times
larger than Rome ever was.

Arab trade will drive innovation
for the next 1,000 years

and expand the global network
to places it has never gone before.

The arabs are sitting
in the middle of afro-eurasia.

There are arab traders who
are sailing off to China.

There are arab traders who are
traveling all the way

to the Atlantic ocean.

So they are sitting
in the middle of the hub.

One secret to arab trade? The camel.

A creature whose ancestor,
like the horse,

escaped across the Bering land
bridge out of north America.

A caravan of six camels can lug
as much as two tons of cargo

as far as 60 miles a day,

twice the load of a donkey caravan
in half the time.

For the first time, camel caravans
open up reliable trade routes

across the formidable Sahara desert,

leading to the formation of
the first states in west Africa.

Arabic trade expands,
moving salt from the Sahara to Rome,

rice from eastern Asia to India,

the secrets of making paper
out of China into Europe,

and countless other inventions
and ideas around the world.

Where does our word for lemon
come from?

Where does our word
for coffee come from?

They're all arabic, because the
arabs brought a huge number

of food crops into Europe.

Oranges, citrus crops,
they come from south China,

yet they don't make it to the west
until the great age of the arabs.

In islamic north Africa, one Italian
merchant named Leonardo fibonacci

becomes well-schooled in the
ways of arab traders.

He picks up on a simple but ingenious
counting system

that originated in India but is
used extensively in the arab world.

His writings will spread this
knowledge to Europe

and around the globe.

With everyone counting the same way,

business and trade will explode.

And because of fibonacci,

people today still,
almost universally,

use the numbers known as
arabic numerals.

But there is another idea
arab traders will spread,

something even more influential.

It originates in China around 800 a.D.

A Chinese alchemist in search
of an elixir for long life,

instead stumbles upon chemistry
that can bring sudden death.

He combines carbon and sulfur
with saltpeter,

a compound made of potassium,
nitrogen, and oxygen.

Forged in the stars,
these elements now come together

to make gunpowder.

The recipe for gunpowder eventually
moves west across the silk roads

to the islamic world,

where Muslim warriors use it to fire
Cannon balls at Christian crusaders.

Europeans pick up on the idea,

embracing and perfecting
gunpowder weapons.

1,492 a.D.

There are roughly
400 million people in the world,

but it is still divided in two.

In the americas, the civilizations of
the aztecs, Mayans, and incas

have all arisen.

While halfway around the world,
in the aftermath of the fall of Rome,

Europe has cracked
like an egg into individual states.

For Italian-born Christopher Columbus,

this means he can appeal for funding
from a succession of European rulers,

until he finally convinces
the king and queen of Spain

to back his expeditions.

It has taken all of earth's history
to make Columbus' journey possible.

For tacking into the wind,
he uses triangular sails,

a technology copied from the arabs.

To guide him, the compass,
an invention from China.

And guiding the needle,

a magnetic field formed
with the core of the planet itself.

Although Columbus is looking for
a new way to sail to India,

what he does instead
is finally and forever

connect the two halves of the world.

The voyage is not just significant
in American history.

As you'll see, it's a pivotal event
in all of human history.

Nothing will ever be the same.

The end of the ice age
marooned large pockets of humanity

on separate sides of the globe
for over 15,000 years.

Now, that's all about to change.

The voyage of Christopher Columbus
in 1492 is taught

as one of the most significant events
in American history.

In fact, it's one of the most
significant events

in all of human history.

Prior to that voyage,
the great world zones

had existed largely in isolation.

By crossing the Atlantic,
Columbus opens up

the vast American world zone,

these two enormous continents of
north and south America,

with the millions of people
that are living there,

the resources that are available.

And for the first time,

people living in eurasia become
aware of this other part of the world.

Until the voyage of Columbus,

these people might as well have
been living on different planets,

so isolated were they.

A trade network that started
with the first civilizations

connected Europe, Asia, and Africa,
now reaches across the Atlantic.

In this vast, new global network,
new hubs will form,

and once again, power will shift.

For most of the last 2,000 years,
Europe hasn't been that important.

Then we get the age of Columbus,
and what do you know?

This is exactly the time where we see
the rise of the west.

This is when the west starts
taking over.

When it gets itself smack-bang
in the middle

of the biggest exchange network
the world has ever seen.

Now, foods that had been isolated
on disconnected continents

begin to move around the world.

Maize from the americas
shows up in Egypt and China.

Potatoes from the andes
prove perfectly suited

to the soils of Ireland and Russia.

The old fertile Crescent grains
like wheat

begin to feed the americas.

New foods mean more
calories, more energy.

Within three centuries
of Columbus' voyage,

the population of the world
will more than double to 900 million.

But the unequal hands dealt
to the two hemispheres

now play out in a deadly climax.

European conquistadors,

inheritors of the agriculture
and animals of the fertile Crescent

and the trade spread along
the vast networks of the old world,

come bearing guns, riding horses,
and carrying infectious diseases.

The result, slaughter.

In the years following
Columbus' first voyage,

95% of the native population
in the americas

will die from European guns and germs.

Once the hemispheres are connected,
nothing can ever be the same.

Take the incredible story of sugar.

Chemically, it's the only source
of fuel for our brains,

a substance we are
programmed to crave.

Raw sugar comes mostly from sugarcane.

Once again, a grass will play a
central role in the story of mankind.

First cultivated more than
6,000 years ago in Asia,

Europeans discovered sugar in the
middle east during the crusades,

and carried it home.

Europe was hooked,

but there's virtually nowhere
in Europe where sugar can grow.

Then we have Christopher Columbus
and the discovery of the new world.

And the Spanish conquistadors,

yes, they initially are very
interested in the gold and the silver.

But really they just wanna
make it rich,

they don't care
how they're gonna make it rich.

And once the gold and
the silver has been looted,

the next step is to
open sugar plantations.

The Spanish themselves don't
want to work in the sugar plantations.

They start looking around
for a new labor force.

And over on the other side of
the Atlantic,

there is a place
where they can buy slaves.

And if we look at the
history of slavery,

the number one destination of slaves
from Africa are sugar plantations.

So the history of sugar

shapes the development of history
through the middle east,

through the crusades, through the
conquest of mesoamerica,

and even the history of slavery
from Africa to the americas.

In the year 1700,
mankind has hit a wall.

Most humans
continue to live simple lives

more like our ancient ancestors
than our own.

When you think back to the world
in 1700,

most people were farmers,

most people practiced small scale
subsistence agriculture,

most manufacturing
was done in workshops.

In 1700, it takes over a year

for cargo and information
to circle the planet,

longer than it would take us today
to get to Mars.

What's holding us back is
how we power our lives.

In Egypt of 2,000 b.C., 90%
of all work was done by human muscle,

with animals kicking in the rest.

By 1700 in Europe,
the majority of work, 70%,

is still driven by human muscle.

Muscle power alone can't
clear the path to the modern age,

but there's a breakthrough
hidden deep within the earth.

As our history of the world
in two hours races towards a close,

mankind has hit a wall.

Human progress is stalled
by the limits of our muscle.

To break through, we'll need
a new way to power our lives

and the entire history of the world.

Remember that billions of years ago
iron from exploding stars

was gathered up into planet earth
during its formation.

Thousands of years ago,

man started using this iron
for tools and weapons.

To keep our forges burning,
we began cutting down our forests.

Now, 300 years ago in britain,
iron is in high demand,

and the trees are running out.

The British need a new source of fuel.

And thanks to
the decayed remains of ancient ferns,

they have one. Coal.

But coal itself won't power mankind
into the modern world.

There's one more fateful twist
in the story.

As the quest for coal takes
miners ever deeper into the ground,

water begins flooding the tunnels.

To pump out the water,
a new invention is needed.

In 1712, Thomas newcomen produces
a pump powered by burning coal

and driven by steam.

Newcomen's machine
is the first practical steam engine.

It is this combination,
energy and engine, fuel and machine,

that will free man
from the limits of his own muscle

and change the world.

The industrial revolution begins.

Along with political revolutions
in America and, later France,

this technological revolution forever
transforms the landscape of the world.

And before long, the Atlantic world
has become the new economic,

therefore cultural, therefore
political, therefore military leader,

and will utterly dominate global
geopolitics from that moment to this.

Trains thunder across the countryside.

By the 1870s, the internal
combustion engine has arrived,

and the Germans invent its killer app,
the automobile.

Oil, the substance which the ancients
considered too flammable

to be of any use, becomes the most
important commodity on the planet,

fueling even more innovation.

The telegraph and telephone
move messages at lightning speed.

With electricity, mankind reclaims
the night from darkness.

The hub of power has shifted.

In 1800, Europeans
and their descendants

control 35% of the land on earth.

By 1900, they control 85%.

By the 20th century, fossil fuels
and the internal combustion engine

have amplified everything,

including warfare.

That technology meant that
military power and military conquest

was something that
could be international,

international in a way
that it had never been before.

In the 20th century,

almost three times as many
people are killed as a result of war

as in the previous 2,000 years
of human history combined.

The application of the industrial
skills, the industrial technologies

of the 18th century reached
their culmination, I think,

with these extraordinary events.

And it's all being driven again by the
micro-fossilized bodies of organic

entities that disappeared
into ancient swamps

millions and millions of years ago.

The industrial revolution also allows
the human population to explode.

It has taken 200,000 years
of human history,

from the dawn of man to the year 1900,

for the population to
reach 1.6 billion.

Now, within the 100 years of the
20th century,

it nearly quadruples to
more than six billion.

The 20th century is the most
extraordinary moment in human history.

Never before have we seen change
on such a scale.

Today, humans number close
to seven billion.

We are the dominant players
on the planet.

We have learned to harness
50,000 times more energy

than our ancestors
just 10,000 years ago.

This energy drives
our fast-paced lives,

and a literal world wide web,
a network that, as we have seen,

has been in the making for as long
as humans have walked the earth.

Our two-hour story is
coming to an end,

a story that really began
14 billion years ago,

with a tiny universe where everything
was all in one place.

Then the big bang,

all the energy that has ever existed
created in an instant.

Gravity sculpted our universe.

For billions of years,
stars and supernovas created

all the elements
we would eventually need.

Then, an extreme earth took shape

and settled into just the
right conditions to support life.

As the planet evolved,
life competed for energy

and grew more and more complex.

Eventually, the conditions were right
for our species to rise.

We mastered stone and fire.

When the ice age came,
we spread around the planet.

And when the ice melted, we
were stranded on different continents.

We learned to bend plants
and animals to our will.

We built cities, then civilizations.

We created a vast network
that linked empires,

joined continents,
then crossed oceans.

Just when it seemed we had reached
our human limit,

we found the energy and technology
to carry us into the future.

On earth, the seeds of the past
have bloomed into a present

filled with energy and creativity.

The stories of billions of lives
have played out against

the backdrop of a universe
almost too vast to comprehend.

In everything that we do,
in all that we are,

we remain
living monuments to the past,

as we continue
to make history every day.