Human Universe

It's been 200,000 years since humans first emerged

in the Rift Valley of East Africa.

Since then, we've learnt to think,

to dream, to work together.

And today our human civilisation spans the globe...

and beyond.

But our planet is a tiny fragile speck of life in a vast,

uncaring universe.

So what next for the apes who went to space?

LOW VOICES SPEAK THEIR LANGUAGE

This cave mouth in northern Spain has been inhabited

for 150,000 years.

There's basic shelter here and safety.

But from time to time,

they left the light behind and headed into the dark.

In these caves you see the transition from just surviving

to living, to observing the world, to enjoying it.

There were gatherings here, people coming together to make art

and not just any old art, but specific representations

of particular animals and particular symbols.

So in these caves we see the beginnings of superstition,

the beginnings of an appreciation that there's not just a present

but there's a past and there's a future.

These early artists were leaving messages to future generations.

And the one that speaks loudest lies far deeper into the darkness.

This handprint was made by a child at least 35,000 years ago

and it's thought it was made by a little girl.

She'd have done the painting by taking paint and blowing it through

her hand...

...onto the wall of the cave.

Now, she would have had a basic understanding of her future,

she'd have known that the seasons pass

and maybe she even looked forward to coming back to this cave one day.

Leaving her mark upon the wall suggests she had started down

the road of understanding time and how it stretched out

into the future.

In 40,000 years, we've learned to see further ahead than

she could possibly have imagined.

We've walked out into a wider world

and made it our own.

And right now we are at a crossroads.

Our civilisation holds the power to shape the future

of the whole planet.

I think we pay far too little attention to the future

and the ability to illuminate it, to predict it is unique to us

and our prosperity, and our very survival

depend very much on what we glimpse out there in the dark.

Science and reason are the flames and in this film I want to convince

you that we must use them to make the darkness visible.

THEY CHAT QUIETLY

In late June, Earth's most northerly community are preparing

to celebrate an important turning point of their year.

It's midsummer in the Arctic, and the people of Svalbard

are approaching the moment when the sun rides highest in the sky,

the summer solstice.

If I were in Manchester I'd say this was the longest day,

but that kind of language doesn't make sense here, 78 degrees north

and midway between northern Norway and the Arctic Circle

cos this day, summer's day, began on April the 20th

and it will end on August the 23rd.

We can predict exactly the moment that the solstice arrives.

So as strange as this long day feels, there is no mystery

as to why it takes place.

THEY SING

The reason for that long polar night and the months of midnight sun

is the geometry of the solar system.

Svalbard is quite literally on top of the world and you feel it

when you're here, it's obvious.

The sun doesn't set, it's somewhere over there at the moment

and throughout the course of the day it just moves along the horizon

right round, 360 degrees as the Earth rotates with the North Pole

pointing directly towards the sun.

And when this place was discovered back in the 1590s,

people didn't know that, or at least it wasn't agreed upon,

it was still possible and indeed argued, back down there towards

the equator in Italy, that the Earth was at the centre of the universe.

It's obvious that it isn't when you come up here.

I wonder what would have happened if Galileo and Copernicus and Bruno

and others had visited Svalbard. I think that everything would have

got worked out much earlier.

After thousands of years of observation,

our inquisitive minds began to develop models of the universe.

The full explanation for the clockwork of the solar system

came in the 1680s, with Isaac Newton and his universal law

of gravitation, which is the first modern law of nature.

What Newton's laws allow you to do is to predict the future

given a knowledge of the present.

Newton's laws describe a clockwork universe.

Planets orbiting stars,

stars orbiting galaxies.

And galaxies falling through a possibly infinite space.

One day, in our own sky, we'll see the galaxy Andromeda

heading our way.

In four billion years' time, it will collide with The Milky Way.

For a billion years, our sky will be filled with cosmic choreography.

And we know that because we can predict the future.

So the laws of physics, in that sense, are little time machines.

They allow you to predict with precision what will happen

in the distant future given a knowledge of the present.

We even see the sun ends its days as it swells into a red giant,

some five billion years from now.

So we can be sure that we, along with all other life on Earth,

will not survive into the far future.

Extinction is a necessary part of the evolution of life on Earth.

99.9% of species that have ever existed have become extinct

and that's a good thing,

because when a species goes, there's a niche available in the ecosystem

for other species to colonise - that's how evolution works.

You know, if the dinosaurs hadn't become extinct,

it's very likely that we wouldn't exist.

So when considering the ultimate destiny of our species

the answer seems obvious - extinction.

But I'd argue this doesn't have to be the case.

We are different to the other species on this planet because we're

intelligent. Intelligence matters and it's extremely rare, in fact

you can argue that intelligence may be extremely rare in the universe.

It is possible that we're the only intelligent species in the Milky Way

galaxy amongst 400 billion suns and countless billions of worlds.

And that makes us extremely valuable and worth protecting.

I think the way to keep this light alive is for humans to continue

to venture out.

And explore.

To this end, we've built a ship large enough for six astronauts

to train in.

This is Aquarius, which is used by NASA as Nemo,

the Nemo missions. And the reason this place is extreme,

if you look here...

is because...

we're below the ocean.

The pressure in here is two and half to three times

atmospheric pressure, which is why I sound like a Munchkin.

50 metres below the surface, Aquarius offers a unique

training facility for deep space exploration.

This is, er, this is brilliant cos you can play at being an astronaut,

I mean, you'd have six astronauts in here. The reason that

they use this as a mission simulator

is because the environment is as close as you can get

to space on Earth, you have to live here for weeks.

And if you stay here for more than one hour -

so we've got one hour - you have to stay here for a further 17 hours

to decompress, so you can't just run away

if you, you know, psychologically feel a bit claustrophobic

and you think "I don't like it," you can't just leave,

it's one of the few places on Earth where that would be the case.

CHATTER OVER RADIO

In recent months, Nemo has been tasked with a very specific type

of deep space exploration.

They're developing methods to space walk onto asteroids,

where gravity will be a fraction of that experienced on the moon.

Whilst at times dreaming of an asteroid encounter is

a lot of fun, the motive behind the mission is deadly serious.

MAN SPEAKS ON RADIO

In 2013, on a wintry morning in Russia,

a massive fireball cut the sky.

RUMBLING

TYRES SKID

Seconds later, it exploded, with 20 to 30 times

more energy than the atomic bomb detonated at Hiroshima.

EXPLOSION

COMMOTION

Earth had been hit by the largest asteroid in more than a century.

And no-one had seen it coming.

It seems our powers of prediction failed us

and that's because, in reality, nature can be chaotic.

I can demonstrate that with a simple experiment.

These are magnets, so let's say that this is an asteroid, then watch

what happens when I set the pendulum off, let's say from this point here.

So I'm going to release it, I've got a laser there.

From exactly that point, I'm just going to let it go.

We see the laser tracing out the path on this photo paper,

this is asteroid orbiting the solar system, gravitationally interacting

with the Earth, the sun of course,

let's say a massive planet like Jupiter.

There you go, it's collided with the yellow one, the sun.

I can do it again and what I'm going to try

and do is line it up in exactly the same way and let it go.

In this case it's radically different, that's because

this is what is known as a chaotic system, there you go,

and it's hit the Earth, so that will be the end of civilisation

as we know it.

The point is that the orbit is critically dependent on what

we call, what physicists call, the initial conditions.

That's how precisely did I line this up, how precisely did I release it,

what precisely happens as it sets off on its path

through the solar system?

In here are the little air currents that deflect it

a little bit, all those infinitesimally small changes

can be amplified in a complicated system such as this.

And that's why it's not good enough to just discover the asteroids

that come near to the Earth, it's not good enough

because one of those tiny nudges could take something that you

might think was safe, just using Newton's laws very naively,

and in fact nudging it onto a collision course with the Earth.

This fundamental feature of nature means that we may get little

warning when the next one comes our way.

So we must continue to track threatening asteroids...

...and develop technologies that will get us out to them at short notice.

In January 2014, the European Space Agency's Rosetta spacecraft

awoke from a 31-month period of hibernation.

It had travelled four billion miles to intercept a comet.