Original subtitles

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

(BABY COOING)

when for the first time, we stare into the eyes of mum and dad

and are welcomed into the arms of the universe.

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

because 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 granddad 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 got a very powerful sense that I was on this rocky planet,

orbiting in the blackness of space around a star.

That understanding of where we are

is the culmination of 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 spec

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.

This is the fortified town of Ait Ben Haddou.

It was built in the 17th century

on the trade route that winds it's way north across the High Atlas

and into the markets of Marrakesh.

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,

and threw them over their houses in honor of the moon god.

And the skies are so crystal clear 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 center 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 center

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 the ancient Greek philosophers thought about these things in detail.

They noticed that when you drop things,

they always fall towards the center of the Earth.

So, therefore, there must be something special about the Earth,

it must be the center 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 center 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,

buildings are spectacular.

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

And that pre-eminence, put it at the center

of arguably the greatest intellectual revolution

in the history of human civilization, 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 breath-taking.

We 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 checkered 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.

That was a change in perspective.

(BELL TOLLING)

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.

(SPEAKING ITALIAN)

COX: 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 it's 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 periods most renowned figures,

Galileo Galilei.

Now, in 1609, Galileo came here to Venice

to commission lenses for his new telescope.

This was the world center 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 is 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 to 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-centered solar system.

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

was the center of the solar system...

And began our scientific exploration of the universe in earnest.

In the last 50 years,

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

We've sent unmanned space craft to every corner of the solar system.

No, no, no, no.

- (HORNS HONKING) - 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 a messenger to Mercury,

the closest planet to the sun.

It's got no acceleration.

I don't know what these sticks do here.

Forty-three missions to Venus.

And 51 to Mars.

Hey-hey.

But only a handful have made it into the solar system's outer most 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 7 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 traveling for 12 years,

it reached Neptune,

the most distant planet in the solar system.

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.

BELL ANDERS: 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.

COX: Of all the flights Major General Bill Anders has taken,

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

MAN: (ON VIDEO) In the eighth year of man flight into space,

the National Aeronautic and Space Administration

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

COX: Together with Frank Barman and Jim Lovell,

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

(ROCKETS IGNITING)

ANDERS: When the rocket ignited the giant 5F1 engines,

putting out a total of seven and a half million pounds of thrust,

the racket was unbelievable.

MISSION CONTROL: We have lift off, lift off at 7.57 a.m.,

Eastern Standard Time.

ANDERS: The sideways forces as those rockets gimballed,

to try to keep us pointed straight up,

threw us around the spacecraft.

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

Within about 30 seconds to a minute,

we flew out of the noise and echo from the Earth

and we knew we were on our way.

GROUND CONTROL: Apollo 8, Houston, you're looking good.

ASTRONAUT: (ON RADIO) This is Apollo 8.

GROUND CONTROL: We hear you loud and clear, Apollo 8.

ASTRONAUT: (ON RADIO) Okay, the first stage was very smooth

and this one is smoother.

COX: The three astronauts had begun the longest human journey

ever attempted.

ASTRONAUT: I can see the entire Earth now out of the center window.

I can see Florida, Cuba, Central America...

COX: Over 68 hours and 57 minutes,

they traveled across 380,000 kilometers of empty space.

Until suddenly, their tiny craft was plunged into darkness.

ANDERS: 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 look back over my shoulder, the stars suddenly stopped.

And there 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.

COX: On Christmas Eve, 7968, Apollo 8 entered lunar orbit.

ANDERS: It was just one crater on top of another crater

and no matter how close you looked,

you were gonna find smaller and smaller craters on top of the big ones.

It looked like a battle field, it was totally beat up.

COX: It was as they emerged

from behind the desolate lunar surface for the third time,

that our perception of the Earth changed forever.

ANDERS: But 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.

ANDERS: The photograph was the shotgun approach,

you figure one of them is gonna hit, and indeed it did.

COX: The photograph Anders took is known as Earthrise.

One of the iconic images of our time.

ANDERS: 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.

COX: 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.

ANDERS: Well, I look up and realize 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.

COX: 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.

(cow MOOING)

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

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

it's very important part of the cowboy lifestyle.

The most important skill when you're roping

is accuracy and judging the distance.

You've gotta be a real good judge of where the steer is gonna be

when you throw your rope.

COX: 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.

COX: Using parallax, 61 Cygni

was found to be 104,000 billion kilometers from Earth.

But this technique only works for our nearest stellar neighbors.

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 neighborhood,

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 cataloging 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 Cepheid.

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

between the actual brightness of the Cepheid variable

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

She noticed that for the dimmer Cepheid variables

the rate of change in brightness is very fast,

whereas for the brightest of the Cepheid's

the rate of change is slow.

So, that means that if you can determine the distance

of 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.

Now, 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 center, but close to the edge.

The Milky Way is a disc of between two 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 center

which they orbit once every 248 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.

MAN (OVER RADIO): Five, four, three, two, one

and lift-off of space shuttle Discovery

with the Hubble Space Telescope, our window on the universe.

COX: 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.

MAN: (OVER RADIO) Do you like this, Houston?

MAN 2: (OVER RADIO) Oh, it's not' bad.

COX: Hundreds of billions of galaxies stretching out in every direction

to the edge of the observable universe and 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.

And we've discovered there are no special places in the universe,

we are not at its center,

we just orbit around one of a trillion suns,

which raises an obvious question,

where did all those stars come from?

(SPEAKING ARABIC)

(GOATS BLEATING)

COX: 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.

(SPEAKING ARABIC)

COX: 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,

just required something that we all possess,

the human imagination.

(KIDS LAUGHING)

COX: Scientists are often described as being childlike,

and the archetypal example is Albert Einstein.

And I think it means thinking with simplicity...

(KIDS LAUGHING)

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.

COX: Einstein would free his mind of the everyday

and allow it to wonder through the universe.

He imagined himself riding on a beam of light.

And by wondering what he might see,

he 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.

This has 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 aluminum

to make the radiation easier to deal with.

Aluminum is not the best thing,

the strongest material, to build a vacuum chamber out of,

so they built 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.

(ALARM BLARING)

It takes 3 hours to pump out the 800, 000 cubic feet of air from the chamber.

Okay, we dropped 2 millitorr in the last 30 minutes.

COX: But once it's complete there's a near perfect vacuum inside.

MAN: 61-04, manual, 10 percent open.

Station one, go for drop.

PCB 30 dash one, pressure set point at 240 psi.

We are go for drop.

Ten, nine, eight,

seven, six, five,

four, cameras on,

two, one, release.

- (LAUGHING) - Exact. Exact.

- They came down exactly the same. - Wow.

Oh, look, look, look.

- Holy mackerel. - (LAUGHING)

Exactly the same.

- COX: Exactly the same. - MAN: The feathers don't move, nothing.

Look at that, that's just brilliant.

COX: 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 if 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 millimeter.

These measurements are so precise,

that using this telescope has found that the radius of the orbits

is decreasing by 1.7 millimeters 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 realized his equations could do far more.

They could rewrite the most universal of human stories.

MAN: (OVER RADIO) 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 waters.

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, and 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 and 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 Belgian 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 described 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 snap shot of the universe

in its infancy.

(MAN COUNTING DOWN IN FRENCH)

COX: On the 14th of May, 2009,

the Planck satellite was launched from ESA's spaceport in French Guiana.

Its mission was to travel

one and a half million kilometers into deep space

and there, far from any interference from Earth,

to witness the birth of the cosmos.

For four years, Plank 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.

(EXPLOSION)

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 then coded 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.

(RUMBLING)

So, this is our place in space and time,

15.8 billion years from the Big Bang...

27,000 light-years from the center 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.

(INDISTINCT CONVERSATIONS)

We've come a long way.

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

and photographed our whole 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.

COX: In finding our place in the universe,

we've come to realize 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 civilization, the only one we know of anywhere in the universe

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

That is our greatest achievement.