Ancient Skies

Ever since the dawn of humanity,

the skies have influenced every part of our lives.

They have helped us to navigate...

For our ancestors, that was their neighborhood.

To build...

The pyramids are aligned precisely towards true north.

And defined the very idea of time itself.

When the sun crosses the horizon, boom!

You know you've been waiting one year.

To explain the movements of everything above us,

we populated the cosmos with gods and monsters.

The sky was understood

as a kind of stone tablet

on which the gods inscribed their messages.

But as we looked deeper into the heavens...

We turned away from belief in a mythical universe...

To a radical new way of thinking.

These phenomena cease to be linked to supernatural gods

and instead become natural.

This is the story of humankind's

obsession with the skies...

And the ways our ancestors made sense of the universe.

This is the story of how we moved from a world

ruled by supernatural beings...

To a cosmos revealed by scientific astronomy.

This is the story of seeing other worlds...

And finding our true place among them.

This is the story of our ancient skies.

Today's technology allows us to see the universe

in ways that were unimaginable even a few decades ago.

We can observe far-off galaxies, millions of light-years away...

Analyze the chemical composition of distant planets...

And even witness the birth of stars.

We know that the moon is orbiting the earth

at 2,000 miles per hour...

And that the myriad of pin-pricks of light in the night sky

are giant burning suns,

- perhaps each with its own set of planets. - Perhaps each with its own set of planets.

The sky is no longer a mystery in the way it was

to generation after generation that came before us.

And yet, when we look up at it with the naked eye,

we are still filled with the same awe and wonder

they must have felt hundreds...

Even thousands of years ago.

For our ancestors, there was no separation

between earth and sky.

Together, they formed a cosmos that we shared

with the supernatural beings that we believed

were an integral part of its working.

Mythology and religion are almost essential ways

of explaining the cosmos.

In ancient Egypt, the sky was personified

by the goddess nut,

who curved her body of stars over the earth.

And the moon was associated with the gods Thoth and Khonsu.

These supernatural beings also inhabited the stories we told

about how the universe itself came to be.

We explain things we can't understand

through using stories,

because none of us really can comprehend

how the universe started.

There are stories to explain the origin of the cosmos

from all over the world.

For the Aztecs of central America,

it was the goddess Coatlicue who gave birth

to the moon and stars.

For Hindus, the god Brahma sat atop a lotus flower

as he created the earth, the sky, and the heavens.

And in Chinese mythology, a hairy beast called Pangu

emerged from a cosmic egg and divided

the forces of yin and Yang into earth and sky.

But our earliest surviving creation myth

dates back almost 4,000 years, to the ancient Babylonians.

It's called the Enuma Elis.

The Enuma Elis tells the story of a colossal battle

between Tiamat, the primordial goddess of the sea,

and the god Marduk.

Marduk is described in extraordinary terms.

He's got fourfold vision, he's got the aura of 10 gods,

he's unfathomable and unvisualizable

in his splendor.

Marduk took up the mace...

And held it in his right hand.

Tiamat and Marduk drew close for battle...

And locked in combat.

Tiamat opened her jaws...

But with his merciless mace...

Marduk crushed her skull.

The battle between Marduk and Tiamat

explained the creation of the earth and ocean,

the sky and everything in it.

It divides the universe into

a top and a bottom.

We have the sky and the earth, and as part of the epic,

and as part of Marduk's role in it,

he creates the stars and the constellations.

He fills the sky with all the things

that are observed in it.

Today, we can still get a glimpse of the cosmos

as the Babylonians saw it...

From the oldest world map ever discovered.

Etched in Clay over 2,500 years ago,

it shows the earth as a flat disc,

floating on the ocean.

The Babylonians imagined their flat earth

at the center of the universe,

with everything in the skies revolving around it.

- Belief in a flat earth was common to many civilizations - belief in a flat earth was common to many civilizations

Across the world...

From the far east of Asia...

To Africa...

And the Americas.

From the point of view of our ancient ancestors,

a flat earth made perfect sense.

We know that the earth is a ball

and it's spinning once a day.

But the thing is that's not obvious.

If you go out without really thinking about that

and just look at these motions,

it feels like the earth is flat

and it feels like the sky is wheeling around you.

We can imagine that the skies must have been

an endless source of wonder and mystery.

A place to be admired and interpreted.

And no matter how far back we go in our human story,

we find evidence of our obsession with the heavens.

Nestled deep within the hills of northern Spain

are the caves of El Castillo.

Here, over millennia,

stone age artists decorated the walls

with hundreds of paintings.

Dr. Jesus Gallego is an astrophysicist,

but he has spent years studying the images

that line the walls of these caves.

Some of them are as old as 40,000 years.

If this is correct, we will be right now

in front of the oldest paintings of the world.

I am surrounded by about 30 hands.

We estimate that 20 belong to women

and 10 belong to men.

I love to consider the possibility of these people

just leaving the contour of their hands...

To leave something for us, the people of the future.

Dr. Gallego believes that

whoever painted these pictures

recorded the things that were most important to them.

Our ancestors were people that were living

very close to nature.

So, it's not a surprise that these people reproduced animals

on the walls of the caves.

Hidden away in one corner of El Castillo

- are a set of paintings that, as an astrophysicist, - are a set of paintings that, as an astrophysicist,

Dr. Gallego finds particularly intriguing.

Some people believe that here we have

a representation of an astronomical motif

which is very important, which is the milky way,

a sequence of faint stars all together

and making one single body.

Other paintings here could also have

an astronomical association.

Some of the current researchers identify here

a sequence of astronomical events

that could be related with moon phases,

with different days of the month.

This is one of the best links that we can find in the cave

related with astronomical phenomena.

These are the earliest paintings yet discovered

that could depict the heavens.

In times when we relied on the natural world

for our survival...

Reading the skies could give our ancestors the edge.

If you go out under the night sky every night

and look around, you eventually become familiar

with the patterns in the sky,

just like you do in your neighborhood.

You know where the trees are, where the bank is,

where the mountains are, and this is even more true

for our ancestors, for ancient peoples.

They were familiar with those stars.

That was their neighborhood.

Our ancestors would have seen the sun

rising and setting in the same directions every day...

And used the positions of sunrise and sunset

to orient themselves.

But even when the sun went down,

the stars still helped us find our way.

When we look up at the sky, all the stars

appear to be circling.

They're wheeling around a point fixed on the sky itself.

We call those the celestial Poles...

The north and south celestial Poles.

And all the stars appear to move around them.

By locating these fixed points in the night sky,

our ancestors could find their bearings.

But the regular motion of the heavens

also made us conscious of something completely fundamental

to how we organize our lives... time.

There are 3 basic cycles in astronomy

if you're outside looking up at the sky

with your naked eye.