All language subtitles for Big.History.S01E06.Defeating.Gravity.720p.BluRay.DD5.1.x264-NTb.EN HOH

[ Narrator]
Drawings no one can see.

Plans written in code.

Clues to Leonardo da Vinci's
hidden obsession-

the quest to fly.

[ Engine Rumbling ]

It will take hundreds of years
to decode the secrets of flight-

secrets revealed by big history.

We think of history as a timeline...

a series of events stretching
a few thousand years into the past.

It's time to think bigger.

Instead of a line,
imagine a web of infinite connections...

interacting over billions of years...

linked together to create
everything we've ever known-

our universe, our planet...

and us.

When we consider our most epic moments
though the lens of science...

we unleash
a revolutionary new idea-

the movement of atoms
steered the movements of men...

civilizations, galaxies.

History as we know it
is about to get big.

One of the greatest minds in history...

tries to crack an impossible code.

Leonardo da Vinci fills
100 pages of notebooks...

with drawings of birds and bats...

and designs for strange machines.

His thoughts are consumed
with one goal:

How can a man fly?

Traditional history tells us
that the Wright brothers...

are the first to achieve the dream
of powered flight...

centuries after da Vinci.

But big history reveals
how man's quest to fly...

is a riddle that' is written
at the beginning of time itself.

Big history connects back...

more than 13.7 billion years.

We are traveling
through the early universe...

just' a fraction of a second
after the big bang.

Matter comes into existence...

along with gravity.

From the beginning of the universe,
gravity will rule matter...

and act as an invisible barrier to flight.

On some planets, like Jupiter...

gravity is so strong,
it would crush us.

On other worlds, like the moon...

it's so weak that it takes almost no effort
to leap several feet up.

[ Astronaut Chattering ]

[ Narrator]
Earths gravity is in the middle.

Strong enough
to keep us bound to land...

yet weak enough
to let some creatures fly.

[ Buzzing ]

So how do insects and birds
defy gravity?

It turned out that birds
were better evolved for flight.

- [ Narrator] It's not' just the wings.
- [ Screeches ]

It's the power behind them.

Flapping their wings gives birds
the thrust they need to get airborne.

Ana' a birds
chest and shoulder muscles...

which work the wings...

make up as much as 50%
of the bird's weight.

In humans, these same muscles
account for less than five percent...

of our body weight.

So birds have 10 times
the flight power we do.

So no matter what da Vinci designs...

people can't fly like birds.

Humans need a different strategy.

This is the age of engines.

Machines with 50 times
the power of a man.

Two bicycle mechanics,
Orville and Wilbur Wright...

believe that an engine
running on gasoline...

can generate enough thrust
to lift an aircraft into the sky.

But the engines of their day
are made of iron and steel...

metals that are strong but heavy.

Everything about the Wrights' plane
has to be strong and light.

If the engine's too heavy,
the plane won't get off the ground.

To defy gravity,
the Wright brothers need a game-changer.

Big history connects the first flight...

to the chemistry of a miracle metal.

It's strong and flexible...

and three times lighter than steel.

It's a very light metal,
but it's also very, very strong.

That's a great combination.

[ Narrator]
It's the most common metal on the planet-

aluminum.

This unique metal is never found
in its pure form.

Aluminum atoms grab on to oxygen
and minerals in the Earth's crust...

and won't let go.

It's so hard to extract...

that in the late 1800s...

aluminum is more valuable than gold.

So valuable that France displays
a few precious bars...

alongside the country's crown jewels.

The metal becomes
an international symbol...

of wealth and power.

When the Washington Monument
was going up in the 1880s...

the U.S. put aluminum
on the very top of it-

a little six-inch pyramid that would
kind of announce to the world...

just how mighty the United States was.

[ Narrator] But aluminum is 26
million times more common than gold.

And it's about to become
a household word.

A young chemist in Ohio,
Charles Hall...

shoots an electric current
through a chemical solution.

The electricity separates the atoms
that bind aluminum.

That finally unlocks
the potential of a metal...

with a unique combination
of lightness and strength.

Hall creates the Aluminum Company
of America, or Alcoa...

to bring the miracle meta! to the masses.

That's good news
for Hall's fellow Ohioans...

the Wright brothers.

They make the crankcase of their airplane
engine out of Alcoa aluminum...

and it cuts the engine's weight
almost in half.

But gravity hasn't been defeated yet.

The rest of their airplane also has to
combine strength with lightness.

Big history has a solution...

that's been waiting
for Orville and Wilbur...

since before the time
of the dinosaurs.

Big history uses science
to see the world in a new way.

It reveals how birds use muscle power
to defy gravity...

and that man's quest to conquer the sky
is impossible...

without the power of engines...

and strong materials...

that are also light...

like aluminum.

But gravity
is the eternal enemy of flight.

And the Wright brothers
still face the problem of weight.

The Wrights have their plane.

The wings provide lift...

and the engine gives it power.

But the structure must be light enough
to get airborne...

yet strong enough to support
the weight of the engine...

and the pilot.

What material can do all this?

Once again, the planet supplies
what they need.

Big history connects back...

to a prehistoric supercontinent.

300 million years ago...

most of the land on Earth...

clusters into
the supercontinent Pangaea.

The vast interior of Pangaea...

is hundreds of miles from
the cool breezes of the shore.

The land dries out.

Without enough moisture,
many trees die...

but some adapt.

They develop cones
to protect their seeds.

These trees survive-

trees like spruce.

After Pangaea breaks apart...

spruce trees are carried
all over the world.

Their wood has a unique quality.

Heavier, heartier woods
like your oaks and all of that-

They're just too heavy.

Lighter woods are too weak.
They're too brittle.

Spruce kind of falls in the middle.

They have just the right amount
of high tensile strength.

Makes it ideal
for making aircraft out of.

[ Narrator] Big history brings together
the strength and lightness of spruce...

and aluminum...

with the power of the gasoline engine...

at the ideal moment...

to defy gravity-

[ Engine Rumbling ]

And lift a man into the air.

Earth gives humanity
the Keys to the sky.

One airplane...

transforms...

into a world of flight.

Now, in a single day...

more than 90,000 planes
take flight around the world.

[Valle ] If it wasn't for
that big history moment...

of the Earth drying out,
effectively...

we wouldn't have that powered flight.

It was the planet drying out
and this one tree going...

“Hey, I can live here now.”

Big history allows us
to piece that all together.

[ Narrator]
Today, we take flying for granted.

But there was a time on Earth
when flight didn't exist at all.

So who were the world's first fliers?

And when did they first
take to the sky?

Big history links back
to a prehistoric forest...

more than 325 million years ago...

when the first creature on Earth
ever to take wing...

isn't a bird.

It's a primitive insect.

Possibly, as it falls from a tree...

it vibrates nubs on its back...

and glides to safety.

Over generations...

the nubs evolve into wings.

[Valle ] Flight is the best way
to get around this planet.

You can use it to travel.
You can use it to mate.

You can use it to hunt for food,
escape predators.

[ Narrator]
Flight is a strategy for survival...

a strategy that paves the way for humans.

[Screeching ]

Big history connects forward
260 million years...

to a moment of impact.

An asteroid the size of Mount Everest...

is on a collision course with Earth.

The dinosaurs are doomed.

[ Groans ]

[ Narrator] Except for one group
that manages to escape-

the dinosaurs that evolved
into today's birds.

One of the reasons
that birds survived...

the extinction
at the end of the Cretaceous...

is probably flight.

If you can fly away,
get up above the burning forest...

try to find small little areas
that weren't burning...

maybe an island in a great lake
type situation...

you can survive.

Flight got 'em out of there.

[ Shrieks ]

[ Narrator]
Their survival is linked to ours.

[ Buzzing ]

We need birds and flying insects
to spread and pollinate...

the plants we rely on for food.

One could certainly argue
that if there had been no flight...

there would be no humans.

[ Narrator]
So we depend on flight.

But flight depends on
something special about the Earth.

There's a clue in a famous catastrophe-

a fiery crash...

that reveals how the planet
makes flight possible.

Big history connects
the story of flight...

to the birth of the universe...

revealing how gravity emerges
within an instant of the big bang...

and becomes the enemy of flight.

How nature fights back...

combining lightness and strength.

And how humanity cracks the code
by harnessing elements...

millions of years in the making.

But big history reveals
there's another player at work in flight.

[ Man ]
Big history is not satisfied...

by simply looking at
the human history of flight.

Does the planet play any role
in enabling flight?

[ Narrator]
Big history looks for answers...

in history's most famous flight disaster-

the German zeppelin Hindenburg.

Four diesel engines power an airship filled
with seven million cubic feet of gas.

In the final fee!
Of its 4,600-mile journey from Berlin-..

The Hindenburg bursts into flames.

But understanding why
the Hindenburg falls...

is to reveal
what first made it take flight.

Big history links
the death of the Hindenburg...

to the birth of our atmosphere.

A! first', ifs a poisonous mix
of carbon dioxide and methane.

Then other gases take over...

mostly nitrogen...

and eventually the gas
we will one day breathe.

Oxygen, originally,
was put into the atmosphere...

by bacteria, as a waste product.

[ Narrator]
Even though we can't see gases...

they're a form of matter
made up of atoms...

that have weight.

Some gases are lighter than others.

So any gas lighter
than Earth's atmosphere...

will float.

Six gases are lighter
than our atmosphere...

including the one
that fills the Hindenburg-

hydrogen, the most common
element in the universe.

But it's also highly flammable.

And because gases in the atmosphere
can carry electric charges...

its a simple spark
of static electricity...

that' dooms the Hindenburg.

[ Siren Wailing ]

But the atmosphere that carries
the Hindenburg's destruction...

is also what supports it...

and everything else that flies.

Just as water provides
an environment for swimming...

Earth is atmosphere,
thinner than water. -.

But with many of the same qualities...

gives us something to push against...

so we can fly.

Let's get a bird and give him
a space suit just over his face...

and put him in space.

And he's gonna flap like crazy
and go nowhere.

Things can't fly in space
by flying as we know it.

Why is this?

Because flying requires you to have wings
that are pushing against something.

When you do a pushup, you're using
the ground to lift yourself up.

When you're flying,
you're using your wings...

to push against molecules
to lift yourself up.

[ Narrator] And the force holding
this invisible ocean in place?

Gravity...

pulling on the atoms of gas
to keep them around the planet.

[ Benjamin ] You're trying to
strike this delicate balance...

between using the atmosphere
to support you...

and to overcome
the, sort of, pull of gravity.

Earth has just the right amount
of gravity...

just the right density of atmosphere
to make flight possible.

[ Narrator]
The eternal enemy of flight...

is also what makes
flight on earth possible.

So we must rely on gravity
while we defy it.

Big history reveals that the planet...

is the Key to cracking the code
of flight.

But the story of flight
is just the beginning.

There's a much bigger puzzle
hidden in big history.

Each episode unlocks a clue.

Everyday things like mountains...

silver...

and cell phones...

hold the key.

Watch them all, and you'll see
this grand mystery revealed-

the big history of time, of space...

the big history of us.