All language subtitles for Human Universe 4of5 Place in Space and Time 720p HDTV

MUSIC: Everlasting Love
by Robert Knight

Every day, in every town,
there's a moment...

...when, for the first time, we stare
into the eyes of Mum and Dad

and are welcomed into
the arms of the universe.

# Open up your eyes
Then you realise

# Here I stand with my
Everlasting love... #

Every human life has to start
somewhere, a place in space and time,

and I started here,
on March the 3rd, 1968,

in the Royal Oldham Hospital.

In 1971 we moved here to
the family home in Chadderton -

it's only about a mile away
from the hospital.

I stayed here for the next 18 years.

In 1979 my world expanded a bit cos I came up
the hill to this school, Hulme Grammar School.

This was my form room, 3Y,
and that was the end of the universe

because the girls' school
was through there.

And it wasn't long before I began
to wonder how my world

fitted into the wider cosmos.

My grandad used to tell me how he
walked up onto this hill

in the summer of 1927
to see a total solar eclipse.

And because of that story, I always wanted to see
one, and I finally got to do it 80 years later.

And it was a very powerful
experience.

I didn't know what I'd think.

He always spoke of
the sky going dark

and everything going quiet
and the birds stopping singing.

What I felt was that
I was on a ball of rock.

I had a very powerful sense that I
was on this... this rocky planet,

orbiting in the blackness
of space around a star.

That understanding of where we are is the culmination
of a 400-year journey of scientific discovery.

This is the story of how we are measuring with
increasing precision our place in space and time.

How we've discovered that we are an infinitesimal
speck in a possibly infinite universe,

and, in doing so,
just how valuable we are.

As far as we know, we humans
are unique in the universe.

The only creatures that have developed the
ability to ask deep questions about the cosmos.

This curiosity has led us
to a profound change in perspective.

From believing we were
the most important creatures

in all creation...

...we have uncovered humanity's
true place in the cosmos...

...and glimpsed our earliest origins.

TRADITIONAL MUSIC

This is the fortified town of
Ait Benhaddou.

It was built in the 17th century on the
trade route that winds its way north

across the High Atlas
and into the markets of Marrakech.

MUSIC CONTINUES

The indigenous Berber people
who built this place

have been in this part of North
Africa for well over 10,000 years,

and they're mentioned in Ancient
Egyptian texts and in Greek -

both Herodotus and Cicero talk of these
people who worship the sun and the moon.

In fact, they tell a story of how
they cut off the ears of goats,

threw them over their houses
in honour of the moon god, Ayyur.

And the skies are so crystal clear
here that you can see why they did it.

Well, not the goat thing, but worshipped
those celestial objects in the sky.

High above the village, the summit affords
an unobstructed view of the heavens.

The perfect vantage point from which
to ponder your place in the universe.

For all of history, or at least, I imagine for
as long as people have considered such things,

the Earth has been thought of as being
motionless, at the centre of the universe.

And when you think about it, that's obvious
- it doesn't feel like we're moving,

and the ground feels solid
beneath our feet,

the proverbial mountains
move for no-one,

and the sun, moon and stars
arc across the sky.

The Earth is motionless at the centre,
and the universe rotates around it.

Watching the night sky,

it's natural to think that
the stars move around us.

And so, for thousands of years,

this geocentric view of the universe
was never questioned.

And it's not just the motion
of the stars -

Aristotle and the ancient Greek philosophers
thought about these things in detail.

They noticed that when you drop
things

they always fall towards
the centre of the Earth,

so therefore there must be
something special about the Earth,

it must be the centre
of the universe.

These arguments are so persuasive that it
was millennia before they were overturned.

It was here in Venice that our demotion
from the centre of the universe began.

Venice was an independent city-state
for well over 1,000 years,

and by the 15th century it was
the richest city in Europe.

You see that legacy everywhere -
the buildings are spectacular,

you can only imagine what it
must have been like in its heyday.

And that pre-eminence put it
at the centre of

arguably the greatest intellectual revolution in the
history of human civilisation - the Renaissance.

The Renaissance was a period when
the rebirth of art and science

transformed how we saw the world.

This is the Scuola Grande
di San Rocco,

and everywhere you look, there is
masterpiece after masterpiece

from one of the greatest artists of
the Italian Renaissance, Tintoretto.

It took him over 20 years,
beginning in the 1560s,

to complete this building.

And it's breathtaking.

You see scenes from the
Old Testament on the walls,

scenes from the New Testament.

And what's striking, apart from
the obvious skill of the painter,

is the realism.
And there - The Last Supper.

You could almost
walk into that painting,

you could walk across
that chequered floor,

up the stairs, turn right and out
through that illuminated doorway.

In the art of the medieval period
and before, you don't see

this depiction of real space,
the paintings are flat.

From the 14th century,

with the rediscovery
of the geometry of the Greeks,

then you see a genuine
intellectual shift,

you see the desire to paint
the world as it really is,

you see paintings
with perspective and depth.

And that was a change
in perspective.

And we got our first hints of our
planet's true place in the cosmos

when this desire to see
things as they are

was combined with the city's
most valuable commodity.

TRANSLATION FROM ITALIAN

During the Renaissance, these
craftsmen were so valuable to Venice

that they were barred from leaving
the city on pain of death.

Murano glass was so prized
because its clarity allowed it

to be fashioned into optics,
into mirrors and lenses.

And it was precisely that property
that caught the eye

of one of the period's
most renowned figures,

Galileo Galilei.

Now, in 1609, Galileo came here
to Venice

to commission lenses
for his new telescope -

this was the world centre
of glass production -

and he immediately put
that telescope to good use

by turning it towards the moon
and sketching what he saw.

In the 1600s, most people thought
that anything in the heavens

was perfect, perfectly round,
perfectly smooth,

but Galileo depicted the lunar
surface as we know it to be today,

the sunlight bouncing off mountains,
disappearing into valleys,

its shaded rims of craters.

Galileo didn't just observe
the moon with his telescope,

he turned it to the planets

and also in 1610 he made this series
of sketches of Venus and he noticed

that, different times of the year,
Venus can appear as a full circle

in the sky or as a slim crescent
and as everything in-between.

When Venus is on the other side
of the sun from the Earth,

we see the whole planet.

But as it moves around in its orbit,

less and less sunlight
is seen to strike its surface

until it crosses the sun
in silhouette.

The only credible explanation
for these phases of Venus

is that Venus is a planet,
it's orbiting the sun

inside the orbit of the Earth,
which is also orbiting the sun.

So, this is the first confirmation
of a sun-centred solar system.

Galileo had seen evidence
that the sun, not the Earth,

was the centre
of the solar system...

...and began our scientific exploration
of the universe in earnest.

TYRES SCREECH

'In the last 50 years,

'we've done more than simply
look out from Earth,

'we've sent unmanned spacecraft to
every corner of the solar system...'

No, no, no!

HORNS BLARE
Tram!

'..Many not much bigger and not much
more advanced than this car.'

Oops, sorry.

It's a beautiful
piece of engineering,

but it's essentially got no brakes.

'We sent Mariner 10 and Messenger
to Mercury,

'the closest planet to the sun...'

It's got no acceleration.

I don't know what
these sticks do here.

2.43 missions to Venus...

'..and 51 to Mars.'

HORNS BLARE

Wa-hey!

'But only a handful have made it

'into the solar system's
outermost reaches.'

In 1977, a chance alignment of the
planets meant that it was possible,

at least in principle,
to launch a spacecraft

to all four of the outer gas giants.

So, NASA launched two spacecraft,
Voyagers 1 and 2.

And just 18 months later,
they reached the largest planet

in the solar system,
aptly named after

the Roman king of the gods, Jupiter.

They explored Saturn...

...before separating, with Voyager 2
going on to visit Uranus.

And then, in 1989,
after travelling for 12 years...

...it reached Neptune...

...the most distant planet
in the solar system.

BIRDSONG

But perhaps the most dramatic
change in perspective

came on the 21st of December 1968...

...when we left the Earth
for ourselves

and set out for another world.

When you're up flying on a beautiful
day, you're certainly free,

like a bird, and I just enjoy
the scenery and the solitude of it.

I've probably got
over 13,000 hours in the air.

But as a fighter pilot,
one of the things I pride myself in

is more landings than I have hours.

Of all the flights
Major General Bill Anders has taken,

he'll be remembered for the one
he made when he was just 35.

In the 8th year of
manned flight into space,

the National Aeronautics and
Space Administration prepared

men and equipment for the most
advanced manned mission to date.

Together with Frank Borman
and Jim Lovell,

Bill climbed aboard the most
powerful machine ever built by man.

When the rocket ignited,
the giant 5F1 engines

putting out a total of
7½ million pounds of thrust,

the racket was unbelievable.

We have lift-off, lift-off at 7:51am
Eastern Standard Time.

The sideways forces, as those rockets
gimballed to try to keep us

pointed straight up,
threw us around in the spacecraft.

If we hadn't been strapped in,
we'd be bouncing off the walls.

We flew out of the noise
and echo from the Earth

and we knew we were on our way.

This is Houston,
you're looking good.

We hear you loud and clear, boys.

OK, the first stage was very smooth
and this one is smoother.

The three astronauts had begun

the longest human journey
ever attempted.

I can see the entire Earth
out of the centre window.

I can see Florida, Cuba,
Central America.

Over 68 hours and 57 minutes,

they travelled across 380,000
kilometres of empty space...

...until suddenly their tiny craft
was plunged into darkness.

The stars just exploded,
I mean, there were...

Every star you ever thought about
was visible

to the degree that it was very
difficult to pick out constellations.

And yet, as I looked back over my
shoulder, the stars suddenly stopped

and it was this big, black hole...

...and that was the moon.

And I must say, that got the hair
on the back of my neck

standing up a little bit.

On Christmas Eve, 1968,
Apollo 8 entered lunar orbit.

It was just one crater
on top of another crater

and no matter how closely you looked,

you're going to find
smaller and smaller craters

on top of the big ones.

It looked like a battlefield,
it was totally beat up.

It was as they emerged from behind
the desolate lunar surface

for the third time

that our perception of the Earth
changed for ever.

When we finally turned around
and were going forward,

like a car driving on
down the highway,

we saw for the first time the Earth
come up on the lunar horizon.

I set the range at infinity,
pointed it at the Earth

and just started clicking away,

changing the F-stop with every click.

The photograph was
the shotgun approach,

figuring one of them was going
to hit, and indeed it did.

The photograph Anders took
is known as Earthrise.

One of THE iconic images
of our time.

After the flight, I've often been
asked what I thought was

the most significant part of
Apollo 8, its biggest contribution,

and I've often said our mission
really was to explore the moon,

but our accomplishment was
that we discovered the Earth.

It was only by looking back
at our planet from afar

that we felt just how small
and delicate a part of the universe

our fragile world really is.

When I look up and realise
that the moon is a long way off,

240,000 miles, and sometimes
it's hard to imagine

that we actually zipped
all the way up there

and around it 11 times and back,
in this day and age.

Hundreds of years of exploration
have revealed our planet

to be just one of eight in orbit
around a star we call the sun.

But understanding our place
in the solar system

is only the first step in finding
our place in the universe...

...because far beyond anywhere
we can visit lie the stars.

Until recently, there was no way of
knowing how distant the stars are.

And so we had no idea of our star's
true place in the heavens.

I've been roping
since I was a little kid.

Now, the older I get,
the more I like roping,

it's a very important part
of the cowboy lifestyle.

The most important skill
when you're roping is accuracy

and judging the distance.

You've got to be a real good judge

of where the steer is going to be
when you throw your rope.

Because our eyes
are a few inches apart,

each one captures a slightly
different view of the world.

And comparing the differences
between the two images

is one of the ways
the brain judges distance.

It's a phenomenon known as parallax.

And remarkably,
you can use the same effect

to measure the distance
to the stars.

Now, the parallax shift of a star
in the sky from one eye to the other

is of course imperceptibly small,

but if you could arrange
for your head to be, let's say,

180 million miles in diameter,

then the parallax shift would be
measurable. And you can do that.

Here are two pictures of
a double-star system called 61 Cygni

taken in May and November.

That's when the earth is on
one side of the sun...and the other.

There is your 180 million miles.

And as you can see,

the shift is small...

but noticeable.

Using parallax,
61 Cygni was found to be

104,000 billion kilometres
from earth.

But this technique only works
for our nearest stellar neighbours.

The vast majority of stars
are so much further away

that they exhibit no perceptible
parallax shift at all.

So to go beyond our local
stellar neighbourhood,

a new technique was required.

And it involved measuring the
brightness of the stars themselves.

If you want to use
the brightness of a star

as seen from the earth's surface
to measure its distance,

then you have to know
how bright the star actually is.

And the first person to work out
how to do that was one of the great

unsung heroes in the history
of astronomy - Henrietta Leavitt.

Leavitt was cataloguing the
brightness of stars from photographs

and she became interested in
a particular kind of star

known as a variable star, which
changes its brightness over time.

So it goes dimmer and brighter,
dimmer and brighter,

over a period of days or weeks
or even months.

She took a special interest
in a class of variable stars

called Cepheids.

Now, what Leavitt noticed was that
there is a simple relationship

between the actual brightness
of a Cepheid variable

and the rate of change of
that brightness - its period.

She noticed that,
for the dimmer Cepheid variables,

the rate of change of brightness
is very fast,

whereas for the brightest
of the Cepheids,

the rate of change is slow.

So that means that if you can
determine the distance

to just one Cepheid variable
by parallax,

then you know the distance
to all of them

just by measuring the rate of change
of the brightness in the sky.

Within a year of the publication
of the paper in 1912,

the size of the Milky Way galaxy
had been measured

and shown to be
100,000 light years across,

with the sun not near the centre,
but close to the edge.

The Milky Way is a disc of
between 200 and 400 billion stars

reaching out in giant spiral arms.

The sun and the solar system

sit within the inner rim
of the Orion arm,

27,000 light years
from the galactic centre,

which they orbit
once every 240 million years.

But as vast as the Milky Way is,

it wasn't long before we found
Cepheid variables

that were far more distant.

Our galaxy wasn't the only one.

Five, four, three

two, one...

and lift-off

of the space shuttle Discovery
with the Hubble Space Telescope,

our window on the universe.

Only 400 years ago,

Galileo used simple glass lenses
to explore the solar system.

Today we use advanced instruments
like the Hubble Space Telescope

to explore the universe.

Do you like this, Houston?

Oh, it's not bad.

Hundreds of billions of galaxies
stretching out in every direction

to the edge
of the observable universe

some 46 billion light years away.

We've discovered
that the universe is far grander,

far more majestic
than anyone suspected

when we first started exploring it
just a few centuries ago.

We've discovered there are
no special places in the universe.

We are not at its centre,

we just orbit around
one of a trillion suns.

Which raises an obvious question -

where did all those stars come from?

TRANSLATION:

For 51 weeks a year,

the 88 households
of Souad's tiny village

make up her entire universe.

But this week will be different.

For a few days every year,
thousands of Berber tribespeople

from across the High Atlas
leave their isolated villages

to attend a festival of marriage...

...in the hope of finding a partner

and so beginning a new chapter
in their family history.

Just as in Souad's family,
for as long as anyone can remember,

each generation of Berber
have returned to this place

to begin the next generation.

Today we can trace our origins
much further back

than our immediate family tree,

back in fact further than the origin
of our species here in Africa,

back past the origin
of life on earth

and the formation of earth itself.

Back, in fact, to what appears to be
the beginning of time.

And that didn't require a journey
of exploration in a spaceship,

flying off into the unknown.

It just required something
that we all possess -

the human imagination.

Scientists are often described
as being childlike,

and the archetypal example
is Albert Einstein.

I think it means
thinking with simplicity.

Following threads carefully
and tenaciously,

seeing where they lead.

Following the implications
of a thought through,

and asking the question
why, why, why, why?

It's having a mind uncluttered

by the adult affliction
of common sense.

Einstein would free his mind
of the everyday

and allow it to wander
through the universe.

He imagined himself
riding on a beam of light.

And, by wondering what he might see,

transformed our understanding
of space and time.

But it was his re-imagining

of an experiment dreamt up
by Galileo in the 1500s

that laid the foundations
of modern cosmology.

Einstein called it
"the happiest thought of my life".

Which is in itself
an almost childlike sentence,

because following that thought
through ultimately led us

to a theory of the origin
of the universe itself.

And there's a place where
you can see with your eyes

what Einstein saw in his mind.

This is NASA's space power facility
near Cleveland, Ohio,

and it is the world's biggest
vacuum chamber.

It's used to test spacecraft
in the conditions of outer space

and it does that
by pumping out the 30 tonnes

of air in this chamber until
there are about two grams left.

It's kind of got
an eccentric construction,

which is part of its history.
It was built in the 1960s

as a nuclear test facility
to test nuclear propulsion systems,

and that meant
that they built it out of aluminium

to make the radiation
easier to deal with.

Aluminium is not the best thing,
the strongest material,

to build a vacuum chamber out of,

so they built an outer concrete skin

which is part radiation shielding
and part an external pressure vessel

so this thing can take the force
that's present on the outside

when it's pumped out
to the conditions of outer space.

Galileo's experiment was simple -

he took a heavy object
and a light one

and dropped them at the same time
to see which fell fastest.

Now, in this case,
the feathers fell to the ground

at a slower rate
than the bowling ball

because of air resistance.

So in order to see
the true nature of gravity,

we have to remove the air.

It takes three hours to pump out

the 800,000 cubic feet of air
from the chamber.

OK, we dropped two millitorr
in the last 30 minutes.

But once it's complete, there's
a near-perfect vacuum inside.

...10% open,
station one, go for drop.

PCB 30-1,
pressure set point at 240 psi.

We are go for drop.

Ten, nine, eight,

seven, six, five, four...

Cameras on. ..Two, one.

Release.

Exact. Look at that.

They came down exactly the same.
Wow! Oh, look, look.

Look how they hit right there.
Holy mackerel!

Exactly.

Exactly the same.

The feathers don't move, nothing.

Look at that,
that's just brilliant!

Isaac Newton would say
that the ball and the feather fall

because there's a force
pulling them down - gravity.

But Einstein imagined the scene
very differently.

The happiest thought of his life
was this.

The reason the bowling ball
and the feather fall together

is because they're not falling.

They're standing still. There is
no force acting on them at all.

He reasoned that if you couldn't see
the background,

there'd be no way of knowing
that the ball and the feathers

were being accelerated
towards the earth.

So he concluded...they weren't.

Instead, Einstein proposed that
the force of gravity is an illusion.

Just as the surface of the earth
isn't flat,

neither, he said,
was the fabric of space.

All objects, like stars and planets,

warp the space and time around them
to produce valleys.

And all objects,
like planets and bowling balls,

move across this curved landscape

giving the appearance
of being diverted by a force.

Einstein called this theory
General Relativity.

Esoteric and strange as Einstein's
theory of gravity seems,

it can be tested.

The Arecibo Observatory
in Puerto Rico has the largest dish

of any telescope
anywhere in the world...

...enabling it to detect
the faintest radio waves

from galaxies far, far away.

When we come back, we should destroy
the shield generator.

Using telescopes like this,

we witness some of the most violent
gravitational events in the cosmos.

The deaths of giant stars.

Entire suns devoured by black holes.

And here at Arecibo, they've studied

one of the most extreme systems
in the universe,

a binary pulsar, and measured
the stars' doomed orbits

as they spiral towards each other
to the last millimetre.

These measurements are so precise
that using this telescope

it's found that the radius
of the orbits is decreasing

by 1.7 millimetres a day.

That number is precisely the number
calculated using Einstein's theory.

This is why I think that Einstein's
theory of general relativity

is arguably the greatest achievement
of the human intellect.

It is, as far as we can tell,
a precisely accurate description

of everything we look at
in the universe.

But Einstein soon realised
his equations could do far more.

They could rewrite
the most universal of human stories.

"In the beginning, God created
the heaven and the earth..."

"..and the earth was
without form and void

"and darkness was upon
the face of the deep."

"And the spirit of God moved upon
the face of the water

"and God said,
'Let there be light'..."

"..and there was light."

Einstein's equations allow you
to predict the shape of space-time

given the distribution
of matter within it.

So if you plug a spherical
blob of matter into his equations -

the sun, let's say - then Einstein's
equations give you a solar system.

They allow you to understand
its past and to predict its future.

And shortly after Einstein
published the theory,

he had another happy thought.

He thought, well, if you can
do that for a solar system,

why can't you do it for a universe?

Think about that for a minute -

understand the past and predict
the future of the entire universe.

Even Einstein thought
he'd gone too far.

Because to do that, you need
to know how matter is distributed

not just around a single star,
but across the whole cosmos.

The simplest thing you can do
is to assume that the universe

is the same everywhere,
there are no special places.

You assume a completely uniform
matter distribution.

And when you do that,

then Einstein's equations
predict something surprising.

They predict that the universe
can't be static,

that the universe is dynamic,
it's constantly changing.

Now, if you have
an expanding universe,

then that implies
that it was smaller in the past,

and ultimately, it implies
that there was a beginning.

The Belgium priest and mathematician
Georges Lemaitre,

who was one of the first to work on
these solutions, put it beautifully.

He said, "The universe must have had
a day without a yesterday."

Einstein's equations describe
the evolution of the universe

all the way back
to its very first moments.

From its adulthood,
with mature stars and galaxies...

...through adolescence...

...to its childhood and the formation
of the first stars.

With every step back in time,
the fabric of space contracts

and the universe gets smaller.

Until 13.8 billion years ago,
it was born...

in the big bang.

And perhaps the ultimate triumph
of our exploration of the cosmos

is that in the last few years

we've taken a snapshot
of the universe in its infancy.

Dix, neuf, huit, sept,

six, cinq,

quatre, trois, deux, un...

Go!

On 14th May 2009,

the Planck Satellite was launched

from ESA's spaceport
in French Guiana.

Its mission was to travel

one and a half million kilometres
into deep space

and there, far from
any interference from earth,

to witness the birth of the cosmos.

For four years,
Planck scoured the heavens,

gathering the oldest light
in the universe -

light that began its journey
to earth

long before there were
any humans to witness it.

Light that is older than any galaxy,

more ancient than any star.

The cosmic microwave background.

This is the photograph of that light

that was released 380,000 years
after the big bang

and has been journeying
through the cosmos ever since,

for almost the entire history
of the universe.

It really is
the afterglow of the big bang.

In those first moments,

the universe was a fireball
of hot, opaque plasma.

But as it cooled,
the first atoms formed

and the first light was free
to roam through the universe.

And encoded in minute temperature
differences in that light,

is the story
of our earliest origins.

Those tiny variations
in the temperature of this radiation

which correspond to tiny
fluctuations in density

in the universe when it was
only 380,000 years old

are vitally important,

because these are the seeds
of the galaxies.

Without these slight
density variations,

there would have been nothing
for matter to coalesce around

and we wouldn't exist.

And that makes this, I think,

by far the most remarkable picture
of all time.

So this is our place
in space and time -

13.8 billion years
from the big bang...

...27,000 light years from the centre
of the Milky Way galaxy...

...on a rocky world orbiting
a yellow main sequence star.

Today, the 21st of June,

the earth's northern hemisphere
is tilted towards the sun...

...and here in Poland, people gather

to celebrate the shortest night
of the year.

We've come a long way.

In only 500 years, we've journeyed
to the edge of our solar system

and photographed our home world.

We've counted the galaxies,

we've captured the most ancient
light in the universe

and measured its age,
and in doing so,

we've discovered
that we are just one planet

in orbit around one star
amongst billions,

inside one galaxy amongst trillions,

afloat in a possibly infinite sea
of space-time.

In finding our place
in the universe,

we've come to realise how small
and fragile a part of it we are.

But it's been the most glorious
ascent into insignificance,

because our physical demotion
has been the inevitable consequence

of a daring intellectual climb

from being the puppets of the gods

to that most rare
and precious thing,

a scientific civilisation.

The only one we know of
anywhere in the universe

that's been able to comprehend
its true place in nature.

And that is
our greatest achievement.