All language subtitles for BBC.Forces.of.Nature.with.Brian.Cox.2of4.Somewhere.in.Spacetime.720p.HDTV.x264.AAC.MVGroup.org.eng

The natural world is beautiful

but complex.

The skies dance with colour.

Shapes of great geometrical beauty

form and disappear.

And the planet itself is constantly
transformed.

But this seemingly
infinite complexity

is the shadow of something deeper.

The underlying laws of nature.

The world we live in
is beautiful to look at.

But it's even more beautiful
to understand.

Everything in the universe
is in motion.

And yet it feels as if we're
standing still.

This appears to be such a simple
observation,

but the study of motion lies at the
very foundation of modern physics...

and leads to the astonishing
conclusion

that the division of time into

past, present and future

is an illusion.

Our intuition is wrong.

Space and time are stranger than
we could possibly have imagined.

From our viewpoint here on Earth,
the planet seems motionless,

as the universe revolves around us.

Every day for
four-and-a-half-billion years,

the sun has risen in the east,

tracked across the sky
and set below the western horizon.

And as the years pass,
so the seasons turn.

Summer fades into autumn...

...and autumn

into winter.

But these seemingly perpetual
cycles are delicate,

evocative hints that our planet
is far from stationary.

I've always loved the passing
of the seasons.

A gentle experience
with a powerful resonance.

I always remember the words of those
hymns that I used to sing

when I was six or seven
that celebrate them.

"Let me plough the fields
and scatter",

"In the bleak midwinter,
the frosty winds made moan."

The daily changes are almost
imperceptible.

The reddening of the leaves and the
cooling of the streams is subtle.

But those changes mask a jarring,
celestial violence.

So what is going on out there
in space, in time,

as the days pass,
the seasons change?

The most familiar aspect of our
planet's motion is the day,

caused by the Earth's rotation.

You'd have to go back to the turn of
the 17th century to find anyone who

would argue that
the Earth doesn't spin.

But you need a piece of 21st century
technology to experience just how

fast it's moving.

We're going to get ourselves
airborne from Wharton, here,

and then we're going to climb up to
altitude and were going to try and

beat the Earth's rotation.

The Earth spins so fast that you
can't beat it with any old crate.

You need something a bit special.

This is a Eurofighter Typhoon.

It flies at least Mach 1.85 -
twice the speed of sound.

I can't tell you exactly how fast,
because it's classified.

They go to at least 55,000 feet,
but again, I can't tell you -

it's classified. And you can't film
down those air intakes,

because they're classified, as well.

This one is BAE Systems'
development aircraft -

I'm going to get in it in

a minute - and it's got all
the test software in.

The pilot told me that, you know,

it's a bit ropey,
so press control, alt,

delete occasionally if it all goes
funny and usually it comes back on.

Which is good.

Get in. Feet-wise, comfy?

Good.

That's for if you need to control it
at any point.

It's unlikely! Unlikely.

Sit back. Right.

Worst comes to the worst,
do it in your glove.

'Time is 6-9, runway 0-7,
clear takeoff.'

Surface wind 350 degrees,
seven knots. Over on cable.

Ready? Yeah. Go for it.

And we're off.

Oh, lovely and bright.

Blue Orchid by The White Stripes

Oh!

♪ You got a reaction, didn't you?

♪ You took a white orchid

♪ You took a white orchid
and turned it blue

♪ Something better than nothing

♪ Something better than nothing
It's giving up... ♪

I have to say, that's the way to
depart an airfield. It is a bit.

You see, on the east side,

everything is darkening up
quite nicely as the sun

starts to set.
And on the ground, it's already...

It's dark on the ground now,
as far as the sun is concerned.

Accelerating.

So that's 9.78.

Yeah. And the G-suit is inflating.
Yeah.

'Turning directly towards
the setting sun,

'the Typhoon accelerates to catch up
with the Earth's spin.

'Beneath us, a 6,000
billion, billion-tonne rock

is spinning at 650 mph.

'Match that speed and something
interesting happens

'to the sun's motion
across the sky.'

650 mph, so we are travelling at
precisely

the speed of the Earth's rotation.

That's right. So if we stop the sun,
it's about two thirds down.

So it should just stay there now,

because we're going at exactly
the same speed as the Earth.

'But travel faster than
the planet's surface,

'and the normal passage
of the day is reversed.'

Right, accelerating.

Accelerating. Oh, there we go.

That's acceleration. Mach 1.

Through the sound barrier.

'As the jet accelerates,

'it starts to overtake
the spin of the Earth...

'..causing the setting sun
to rise again.'

Starting to grow a little.

It is, I can see it.

We are beating the Earth!

Absolutely terrific.

Starting to climb again,
you can see it. Yes.

That's Mach 1.4.

So it's 1,000 miles an hour.

We're doing almost
1,000 miles an hour.

And now the sun, it's almost a full
vista with the clouds.

The sunrise! It is.

Two sunrises in one day!

And all you need is the world's most
advanced fighter aircraft.

There we go.

Beautiful.

We've done it,
we've outrun the Earth!

Goodbye, sun! Yes, right.

Let's get ourselves on our way home.

Do me a favour.

We've had a bit of a quarrel with
Lambeth parking services.

Just one last favour
before we left.

So that worked beautifully well.

What happens when you light those
engines on full,

accelerate up to 1.4 times the speed
of sound,

you can't tell you're going at that
speed at all,

apart from the fact that out
in the front of the cockpit,

the sun just gently rises up again

in the West, over Ireland.

And then you put the brakes on
and your face goes funny.

But it was terrific.

Thank you.

And for the tape, he wasn't ill.

To turn on its axis once every 24
hours,

the Earth is spinning at breakneck
speed.

At the equator, where the ground has
furthest to travel each day,

its speed exceeds 1,000 miles an
hour.

Which presents a deep paradox.

Here, right now, on a lazy spring
day in the south of England,

this piece of ground is thundering
along at 650mph, and yet,

I can't feel it.

And when you think about it,
that's a very strange thing.

I mean, what is motion if you
can't perceive it?

Well, the answer is a deep one.

You can't perceive that you're
moving

if you're travelling in a straight

line at a constant speed.

And that's a fundamental
property of nature.

It's the way our universe is
constructed.

So I don't feel that I'm moving from
minute to minute,

because I'm almost moving in a
straight line.

I have to make it round in a circle,

but it's 15,000 miles around
and I have 24 hours to do it.

Although we don't experience the
sensation

of moving around our planet's axis,

we do experience events that are
a direct consequence of living

on a spinning globe.

In the Philippines,

the warmth of the tropical sun and
the spin of the Earth conspire to

produce some of the most extreme
weather on the planet.

And for the people who live here,
it poses an ever-present threat.

With the kids out of the way,
Leanilla begins the work

she hopes will allow them
to leave Tacloban for ever.

Every time it rains, darker memories
rise to the surface.

Three years ago, driven by heat
rising from the tropical waters,

a storm formed
over the Pacific Ocean.

As it tracked north,

the Earth's rotation gave rise to a
force known as the Coriolis force,

which acted on the air falling into
its low-pressure heart,

causing the storm to spin,

increasing its intensity.

So what began as a tropical storm at
sea hit Tacloban as a category five

super-typhoon.

Leanilla's family were caught
directly in its path.

Leanilla took the children and
sought shelter in the local church -

the only solid structure
in the neighbourhood.

But while the family were in the
relative safety of the church,

Leanilla's husband was caught up
in the chaos raging outside.

Boosted by the Coriolis force,
winds approaching 200mph

whipped up the ocean...

...into a devastating storm surge.

Over 90% of the city was
destroyed...

...leaving Leanilla with an anxious
wait for news of her husband.

Exposed to the full force
of the storm,

Juvie had been swept inland
for more than a mile.

The Hernandez family experienced a
singular event that affected their

lives dramatically and directly.

The Coriolis force that caused it

isn't a fundamental force
of nature in its own right.

It appears because of
the Earth's rotation.

So-called fictitious forces like
this arise whenever anything spins

or rotates.

And because the Earth's orbital
motion through space is complex -

affected not only by the sun,
but also the moon -

there are other
fictitious forces at work.

One of these plays a subtle but
important role

in a twice daily phenomenon
with which we are all familiar.

The ebb and flow of the tides.

We usually think of the moon in
orbit around the Earth

as the Earth stays still.
But that's not quite right.

Actually, they are both in orbit.

They are in orbit around a point
called the common centre of mass

of the Earth-Moon system.

Essentially, what's happening
is something like that,

although it's quite difficult to do.

Now, when things
rotate around in circles,

other forces come into play.

In this case a force
called the centrifugal force.

So that's the force you'd feel if
you were hanging on to a roundabout,

going faster and faster and you have
to hang on tighter and tighter

because of the force
trying to throw you off.

That's the centrifugal force.

Now, let's bring the moon back.

So now there are two forces at play
in this system.

There's a gravitational pull -

the moon - which pulls
everything towards it,

and there's that centrifugal force,
trying to throw everything off.

And they are in perfect balance
at the centre of the Earth.

But think about the ocean, here.

That's closer to the moon,

and so the moon's gravitational pull
wins and you get a tidal bulge.

Now think about this point
on this side of the Earth.

That's farther away from the moon,
so the centrifugal force wins,

throwing the water off,
and you get a tidal bulge.

Now the Earth just rotates
underneath those tides

once a day and that's
why you get two tides every day.

On an English beach, the complex
gravitational interaction

between Earth and Moon is distilled

into the gentle advance
and retreat of the waves.

But in some parts of the world,
on a few days of the year,

this mismatch of the forces across
the Earth

unleashes something
far more destructive.

For nearly 4,500 miles, the Amazon
snakes through dense rainforest

from its source high in the Andes to
the shores of the Atlantic Ocean.

And here, close to the mouth
of the river,

its banks are home to the Rivieros.

In this remote part of the jungle,

Joao's family are completely
dependent on the river.

The Amazon is the centre
of their world...

...the place where
they work and play.

But today is different.

Today, they must get away from the
water.

Because this part of the river

is home to a monster.

In the ancient Tupi language,
Pororoca means "great roar".

A sound so loud,
it can be heard ten miles away.

Pororoca...

When the moon and sun fall into
alignment with the Earth...

...their gravitational pull is
combined...

...causing the Pororoca to emerge
from the ocean.

The Pororoca is one of the biggest

and most powerful
tidal waves on the planet.

A seething wall of water that
engulfs everything in its path

as it surges up the river
for nearly 200 miles.

But as the Pororoca strikes,
not everyone is trying to escape.

♪ My veins are blue and connected

♪ And every single bone
in my brain is electric

♪ But I dig ditches
like the best of 'em

♪ Yo trabajo duro
Como en madera y yeso... ♪

Serginho Laus has devoted his life
to surfing the Pororoca.

Waiting for the few times a year

when the Earth's orbit around the
sun and the centre of mass

of the Earth-Moon system

provides the ultimate ride
through the jungle.

Then, as suddenly it appears,
the Pororoca passes...

...leaving nothing but stories
in its wake.

The tides are a familiar,

everyday result of the details of
the Earth's complex spinning

and rotational motion, and its
gravitational dance with the moon.

We experience them almost
from moment to moment,

certainly over the length
of one lazy summer's afternoon.

But the very existence of the moon

has its origins in a series of
chance events way back in deep time

that created this stage
on which we live out our lives.

4.6 billion years ago,

the solar system formed
from a cloud of gas and dust,

collapsing under its own gravity.

As the cloud fell inwards,

it began to spin.

And it was out of this maelstrom
that our planet was forged,

from colliding rock and ice.

The Earth's spin was taken from the
primordial cloud

out of which it formed.

With every impact, the Earth grew,
until eventually...

...the sun rose over
the newly formed planet...

...for the first time.

The first sunrise and the first day.

For around 100 million years, the
young Earth circled the sun alone

until, it's thought, a catastrophic
impact resulted in the creation

of our planet's constant companion.

It's not long after
the Earth formed,

a planet the size of Mars crashed
into it in a glancing collision,

throwing rocks and debris thousands
of miles out into space.

And over time, those rocks coalesced
together to form the moon.

The moon formed 15 times closer to
the Earth than it is today,

so it wasn't 250,000 miles away,

it was ten or 15,000 miles away.

It would have been a smooth object

with volcanoes
just seething with lava.

An incredible sight.

The collision that formed the moon
also had a dramatic

and lasting effect on the Earth.

You might expect that when the
planets formed

out of that rotating disc of
gas and dust, then they

would all spin along with it.

So their spin axis would be at right
angles

to the disc of the solar system.

But that collision that
formed the moon knocked

the Earth over, so now
it's at an angle of 23.5 degrees.

And that means,
as it orbits around the sun,

then at some points, the northern
hemisphere points towards the sun,

and at other points, the northern
hemisphere points away from the sun.

A random event that happened so long
ago has shaped the character of our

planet ever since, and we
experience its legacy every day.

But these spins and orbits have had
a deeper effect because they are an

essential part of the stage upon
which life evolved,

and over billions of years natural
selection has shaped the animals

and plants that live on Earth

in response to this
celestial clockwork.

The lowly dung beetle
is a beautiful example.

Their lives revolve around dung.

Eating it...

...fighting over it...

...before rolling it away to safety.

To aid their getaway,

the beetles have evolved a trick
that's intimately linked to the

mechanics of the heavens.

Using specialised photoreceptors
on the tops of their eyes,

they track the sun as it sweeps
across the sky,

using it to guide them on the
quickest straight-line path

away from the other beetles.

But as night falls, the sun dips
below the western horizon

to be followed across the sky
by the moon.

So, by night, nocturnal beetles
navigate by moonlight.

And after the moon itself
has set in the dead of night,

they navigate by the light
of the Milky Way.

It's as if the beetles
carry an imprint

of events that happened
billions of years in the past.

Their unique behaviour
can be traced back

to the origin of the solar system.

The collisions that set our world
spinning,

and the catastrophic impact
that created the moon.

We are separated from the violence
of our planet's history

by the passage of time.

Although, almost paradoxically,
it's in our experience of time,

the setting of the sun,

the rise and fall of the tides,
and the passing of the seasons...

...that we glimpse the reality of our
voyage through space and time.

It's July 10th
and the northern hemisphere

is tilted towards the sun.

That means the sun rises
high across the sky,

and that increases the amount of
sunlight falling

on the ground in this little part of
Oxfordshire, and that heats it up.

The English summer is in full swing.

But the Earth is on the move.

A planet continuing to thunder
around the sun

because of the principle of inertia,

its straight-line path
curved into an orbit

by the force of gravity.

And as the Earth
moves on that orbit,

the North Pole tilts away from the
sun and the violence of all that

celestial mechanics is distilled
into the gentle sensation of a lazy

summer's day, giving way

to the crisp chill of autumn.

The sun rides lower in the sky
and the nights draw in.

As the Earth continues
a yearly voyage,

the North Pole tilts still further
from the warmth of the sun.

Autumn...

...becomes winter.

The sun barely rises above
the tops of the trees,

and Britain is plunged
into a deep freeze.

In the temperate latitudes
of Oxfordshire,

the passing of the seasons
is relatively gentle.

But if you head north,

Earth's 23-degree tilt delivers a
much more powerful challenge to the

people that live in these lands of

midnight sun
and perpetual winter night.

Sitting on the Arctic Circle,
Tasiilaq experiences

one of the largest seasonal
temperature swings on the planet.

In summer, days are long and mild,

with nearly 23 hours
of daylight to enjoy.

Mmm!

The dramatic seasonal
shifts present elemental

challenges to families
like the Christiansens.

As the Earth journeys
around the sun,

the whole of Greenland
is tilted outwards

towards the cold blackness of space.

Human beings evolved in the
equatorial valleys of Africa,

and they're not well suited
to the Arctic winter,

where wind speeds exceed 100mph
and temperatures plummet

towards -30 Celsius.

We require all the ingenuity and
skills passed down from generation

to generation to survive until
the sun rides high again.

To search for food, Michael,
Malik and their friend Enoch

must head out onto
the treacherous frozen ocean.

They've come here because,
beneath the ice,

the ocean waters teem with life.

Despite appearances,

the frozen depths of winter are
in fact the best time to fish.

For just a few months, ice provides
a platform over the ocean,

giving easy access
to the fish below.

A brief window in which
they must catch enough

to last the entire year.

Lessons learned this winter will
stay with Malik

for the rest of his life.

Until he becomes a hunter himself.

Our planet's motion leads to
something beyond the shifts

in the thickness of the ice
and the lengths of the days.

It's reflected in the ever deepening
relationship between father and son.

The seasonal shifts in the colours
and sounds of the wood are life's

response to the clockwork of the
solar system.

Spring will follow winter as long as
the Earth orbits the sun.

The cycle of the seasons
is effectively eternal,

with the Earth returning
to the same place every year.

Except it doesn't return to the same
place, because we don't only travel

through space, we also travel
through time.

We live on a spinning ball of rock,

hurtling through the universe.

And yet in only a few moments

does the violence of our world's
motion break through.

For the most part,

our planet's movement is completely
imperceptible to us.

But there is a consequence of motion
that affects us all more deeply than

any other -
our journey into the future.

Once every year, Antonio Carter

comes to the Church of St
Constantine to pray for his life.

In just a few hours,
he will risk everything

taking part in the Ardia...

...the town's annual horse race.

A tradition that has been part of
his life since childhood.

As the Earth has circled the sun,
the Ardia has remained constant.

The highlight of each passing year.

The race itself is a perilous
cat-and-mouse chase

through the village's
most treacherous streets,

that's taken place on the same two
days in July for hundreds of years.

Every year, the riders appear to
take

the same circuit around the same
Sardinian town, at the precise

moment the Earth returns to the
same place in its orbit.

But the reality is different.

With every passing moment,

we move to a different place
in the universe.

Not just in space, but also in time.

We are hurtling into the future
at the speed of light,

and it's that motion we experience
as the passing of time.

It's only in the last century

that we've discovered
just how deeply motion

and time are intertwined.

We feel as if we move through
space as time ticks by,

but that's an illusion.

The separation of space
and time is false.

The first person to realise that
was Albert Einstein.

He thought deeply about motion,

the idea that we can't tell whether
we're moving or not, and he tried to

reconcile that with our picture
of the universal laws of nature.

And he found that he could do,

but at the expense of
jettisoning space and time

as separate entities and merging
them together into a unified whole,

a fabric of the universe
called spacetime.

In spacetime, the central idea
is that of an event,

a moment that has a location
in space and time.

So, although I've come back to this
same place, this wood,

over the course of the year
in summer, autumn, winter

and now spring,
each one of those visits

is a different moment with a
different location in spacetime.

As the Earth moves through
spacetime,

its orbit traces out a spiral as it
circles the sun

and races into the future.

It never returns to the same place

because each moment
is a different location

in the fabric of the universe.

And just as the Earth travels

relentlessly onwards on its path
through space time...

...so must we.

So this is how Einstein asks us to
picture the sweep of our lives -

the experience of living.

Our lives are series of moments

and they're laid out
like places on a map.

There is me as a little baby

with my dad and with my grandad.

That idyllic summer,

some time in the early '70s in a
paddling pool with my sister.

I was about four years old.

And the perfect Christmas,

with my grandparents some time
back in the 1970s.

There is me when I was 20 years old

with a ridiculous haircut.
I was playing a gig somewhere

in the middle of Europe -
in Budapest, I think.

Wedding day.

And me in Oldham where I grew up...

...with my little boy, George.

This isn't exactly like a map.

See, I can return to these places in
space -

to Oldham, to central Europe,

to Duluth, Minnesota - where I got
married - back to Oldham again.

But I can't return to these moments,
to these events in spacetime.

Because of the geometry
of spacetime itself,

we are compelled to move
inexorably into the future.

As we all journey through
spacetime,

it's only in our memories that
we can revisit the past.

But just because we can't go back
in time...

...doesn't mean that
the past isn't out there.

If you take Einstein's
universe at face value -

and there's no reason
why you shouldn't -

it's our best theory
of space and time,

and this picture of spacetime with
events placed within it suggests

something wonderful
and, I think, quite magical.

See, if I leave a place in space,

then it doesn't cease
to exist when I've left it,

and in spacetime,
if I leave an event,

it doesn't cease to exist
when I've left it.

So, that suggests that all those
summers you spent

with your mum and dad,

or that first Christmas with your
grandparents long ago,

all those most precious memories
of people and places,

all those summers and winters passed
and seasons yet to come

are out there,

somewhere in spacetime.