Wonders of the Universe (2011–…): Season 1, Episode 2 - Children of the Stars - full transcript

In the second stop in his exploration of the wonders of the universe, Professor Brian Cox goes in search of humanity's very essence to answer the biggest questions of all: what are we? And where do we come from? This film is the story of matter - the stuff of which we are all made. Brian reveals how our origins are entwined with the life cycle of the stars. But he begins his journey here on Earth.

Why are we here?

Where do we come from?

These are the most enduring
of questions

and it's an essential part
of human nature

to want to find the answers.

And we can trace our ancestry back
hundreds of thousands of years,

to the dawn of humankind,

but, in reality, our story
extends far further back in time.

Our story starts
with the beginning of the universe.

It began 13.7 billion years ago.

And today, it's filled with over
100 billion galaxies,



each containing
hundreds of billions of stars.

In this series,
I want to tell that story,

because, ultimately,
we are part of the universe,

so its story is our story.

This film is about the stuff that
makes us and where it all came from,

because understanding our own
origins means understanding
the lives of stars.

And how their catastrophic deaths
bring new life to the universe.

Because every mountain,

every rock on this planet,
every living thing,

every piece of you and me
was forged in the furnaces of space.

This is Pashupatinath,

in the Nepalese capital city
of Kathmandu

and Hindus come here
from all over India and Nepal

to worship the god Shiva.
That is Shiva's temple.



Now, Shiva is
the god of destruction.

In the Hindu faith,
everything has to be destroyed,

so that new things
can be created

and that's why pilgrims come here
to the banks of the Bagmati River,

at the foot of Shiva's temple.

The belief in this cycle
of creation and destruction

lends Pashupatinath
an added significance.

Many of these pilgrims will have
come here at the end of their lives,

to die here and be cremated.

Hindus believe in reincarnation,

an eternal sequence
of death and rebirth.

Cremation helps free the soul,
so it's ready for the next life.

'They also believe that the physical
elements of the body are released'

back to the world,
so they can be recycled
in the next stage of creation.

'It's an ancient belief
that touches on a deeper truth
about how the universe works.'

Every civilisation,

every religion across the world,
has a creation story.

It tells of where we came from
of how we came to be here and of
what will happen when we die.

Well, I have a different creation
story to tell and it's based
entirely on physics and cosmology.

It can tell us what we're made of
and where we came from.

In fact, it can tell us what
everything in the world is made of
and where it came from.

It also answers that most basic
of human needs, to feel part of

something much bigger,
because to tell this story

you have to understand
the history of the universe.

And it teaches us
that the path to enlightenment

is not an understanding
of our own lives and deaths,

but the lives and deaths
of the stars.

My creation story is the story of
how we were made by the universe.

It explains how every atom in
our bodies was formed, not on Earth,

but was created
in the depths of space,

through the epic lifecycle
of the stars.

And to understand that story,
we will journey to the stars
in all their stages of life.

This is where stars are born,
a nebula -

a stellar nursery,
where new stars burst into life.

Those stars will burn
for billions of years,

until their voracious
hunger for fuel

forces them to blow up,
to become giants...

..hundreds of times
the size of our sun.

And when they die, stars go out with
the biggest bang in the universe.

But to understand
how we came from the stars,

we must begin our journey
much closer to home.

Well, this is sunrise over Nepal

and those are the tallest mountains
in the world, the Himalayas.

Every one of those peaks
is over 6,500 metres.

What a spectacular sight.

But it's incredible to think that,

just a few
tens of millions of years ago,

those mountains were
something very different.

'The Himalayas haven't
always been mountains.'

We can find clues
to their true origin

by looking at them more closely.

This is Himalayan limestone,

the rock out of which much of this
magnificent mountain range is made.

If you look closely, you can see
a kind of chalky granular structure,

because limestone is made primarily
out of the bodies, the shells,

of dead sea creatures - coral
and polyps - and when they die,

they are put under
immense pressures and squashed

and eventually form limestone.

So the Himalayas were once
living creatures.

Much of the rock in the Himalayas
was formed at the bottom of an ocean
and then, over millions of years,

it was raised up,
to become these vast peaks.

We've even found fossils
at the top of Mount Everest.

It's a beautiful example
of the endless recycling
of the earth's resources

that has been going on
since the dawn of time -

and we are part of that system.

Every atom in my body
was once part of something else,

so an ancient tree or a dinosaur
or a rock, in fact,

definitely, a rock. And the reason
that the rocks of the Earth

can become living things
and then living things will return

to the rocks of the Earth
is because everything

is made of
the same basic ingredients.

Those ingredients are
the chemical elements,

the building blocks
of everything on Earth.

Elements like hydrogen,
helium, lithium,

beryllium, borum, carbon, nitrogen,

oxygen, fluorine,
neon, sodium, magnesium...

Everything in the world is made up
of the same basic sets

of chemical elements,
just assembled in different ways.

So these mountains, the Himalayas,
are made of limestone - and that's
calcium carbonate.

Now, calcium, carbon and oxygen
are three of the elements
that are vital for life,

so calcium in my teeth and bones,
oxygen in the air that I breathe

and carbon in every organic molecule
in my body.

Now, you're probably
pretty familiar with those elements
in their combined forms,

but you very rarely
see the elements on their own.

There's a good reason why many
of the elements are not found

in their raw forms in nature.
They're extremely reactive.

This is sodium.

As you can see, it's a silvery
metal and it's also quite reactive.

In fact, it's so reactive that
when you drop it into water...

..you get a violent,

almost explosive, reaction,

which is all the more surprising
when you think that,

when combined with chlorine,
this forms sodium chloride...

EXPLOSION

..salt, which is vital for life.

Excellent! Ha-ha!

And that's why I love chemistry

almost as much as physics!

It's this reactivity that enables
the elements to combine with one
another to make new substances.

CAMERA MAN: Where's it gone?
Where the hell's it gone?!

BRIAN LAUGHS

That, in turn, has allowed the Earth
to develop its endless variety.

And that variety includes us.

So, to explain where we come from,

we must also explain
where the elements come from.

We now know that the Earth
is made of 92 chemical elements

and that's pretty amazing,
if you think of the complexity
that we see around us.

We also know that
everything beyond Earth, everything
we can see in the universe,

is made of those
same 92 elements.

And notice that I didn't say,
"We think" that that's what
they're made of.

I said, "We know"
that's what they're made of,
because we can prove it.

The chemistry set we have on Earth
extends far beyond the planet.

We have set foot on the moon
and know that it's rich
in helium, silver and water.

We have sent robot landers
to our neighbouring planets
and discovered that Mars

is rich in iron, which has
combined with oxygen to form
its familiar rusty-red colour.

And we know that Venus's thick
atmosphere is full of sulphur.

We've sent spacecraft
to the edge of the solar system

to discover that Neptune is rich
in organic molecules, like methane.

But what of the
rest of the universe?

It seems impossible that we could
discover what the stars are made of,

because they're so far away.

Even the nearest star,
Proxima Centauri,

is ten thousand times
more distant than Neptune,

4.2 light years from Earth.

And the nearest galaxy, Andromeda,

is another 2.5m light years away.

Yet despite these vast distances,
these alien worlds are constantly

sending us signals, telling us
exactly what they're made of.

Our only contact with the distant
stars is their light,

that has journeyed across
the universe to reach us,

and encoded in that light
is the key to understanding
what the universe is made of.

And it's all down to a particular
property of the chemical elements.

You see, when you heat the elements,
when you burn them, then they give

off light and each element gives
off its own unique set of colours.

This is strontium and it burns...

..with a beautiful red colour.

Sodium is yellow.

Potassium is lilac.

And copper is blue.

Each element
has its own characteristic colour.

It's this property that tells
us what the stars are made of.

But it's a little more complicated
than simply looking at the colour
of the light that each star emits.

You can see why, by looking
at the light from our
nearest star, the sun.

This is a spectrum of the light
taken from our sun

and, you know, at first glance,
it looks very familiar.

It looks like
a stretched-out rainbow,

because that's exactly
what a rainbow is.

It's the spectrum of the light
from the sun in the sky.

But if you look a bit more closely,
then you see that this spectrum
is covered in black lines.

These are called absorption lines.

Each element within our sun not only
emits light of a certain colour,

it also absorbs light
of the same colour.

By looking for these
black lines in the sun's light,
we can simply read off a list

of its constituent elements,
like a bar code.

For example, these two black lines
in the yellow bit of the spectrum
are sodium.

You can see iron.

Right down here
you can see hydrogen.

So, by looking at these lines in
precise detail, you can work out
exactly what elements are present

in the sun and it turns out
that that's about 70% hydrogen,
28% helium and 2% the rest.

And you can do this, not only for
the sun, but for any of the stars

you can see in the sky
and you can measure exactly
what they're made of.

That star there is Polaris,
the Pole Star,

and you can see that because all
the other stars in the night sky
appear to rotate around it.

Now it's 430 light years away.

But we know just by looking at the
light that it has about the same
heavy element abundance as our sun,

but it's got markedly less carbon
and a lot more nitrogen.

And the same applies
for other stars.

Vega, the second brightest
star in the northern sky,

has only about a third
of the metal content of our sun.

Whereas,
other stars are metal-heavy.

Sirius, the dog star, contains
three times as much iron as the sun.

And Proxima Centauri
is rich in magnesium.

But although the quantities
of the elements may vary,

wherever we look across space,
we only ever find the same
92 elements that we find on Earth.

We are made of the same stuff
as the stars and the galaxies.

But where did all this matter
come from?

And how did it become
the complex universe we see today?

In order to understand where we came
from, we have to understand events

that happened in the first few
seconds of the life of the universe.

So when the universe began,
it was unimaginably hot and dense.

We, literally, don't have the
scientific language to describe it,

but it was, in a very real sense,
beautiful.

There was no structure,
there was certainly no matter.

It was exactly the same
whichever way you look at it.

We can get some idea
of how the universe developed

from this state of pure symmetry
by looking at the behaviour of water

in this remarkable landscape.

These are the El Tatio geysers,
high in the Chilean Andes.

As the boiling water bubbles up
through the ground to meet

the freezing mountain air,

water can be found in all three
of its natural phases -

vapour, liquid and ice.

In its hottest state, water is,

like the early universe,
an undifferentiated cloud.

But as it cools, it suddenly
behaves very differently.

You see, if you look at a cloud
of steam, it looks the same
from every direction,

but as it cools down,
as it lands on this plate
of freezing cold glass,

then it immediately
crystallises out.

It turns into solid water - ice.

As the ice crystals form,
the symmetry of the water vapour

disappears from view and complex,
beautiful structure emerges.

In the same way, we think
that the universe, as it cooled,

went through a series of these
events, where structure emerged.

One of the most important
was about a billionth of a second
after the Big Bang.

In that moment,
an important part of the symmetry
of the universe was broken.

Known as electroweak symmetry
breaking, this was the moment when

subatomic particles acquired mass -
substance - for the first time.

Amongst them, were the quarks.

As the universe continued to cool,
those quarks joined together

to form larger,
more complex structures,
called protons and neutrons.

Way before the universe
was a minute old,

the quarks had been locked away
inside the protons and the neutrons

and they were the building blocks
of all atomic nuclei,

the building blocks of the elements.

These same protons and neutrons
are with us to this day.

They form the hearts,
the nuclei, of all atoms.

Just a few seconds after
the beginning of the universe,

the fundamental building blocks
of everything had been created.

It sounds ridiculous,
the fact that everything you need

to make up me and everything
on planet Earth and,

in fact, every star and every galaxy
in the sky was there,

after the first minutes
in the life of the universe.

It's almost unbelievable,
but we have extremely strong

experimental evidence to suggest
that that is the way that it is.

But from that point on,
it was just, in a sense,

a process of assembling those bits
into more and more complex things.

That is an incredibly
fascinating story in itself.

To tell that story,
we must look deep inside the atom,
to the nucleus at its centre.

Here, we can see how protons
and neutrons are assembled,

to build up
the 92 different elements.

Now, the wonderful thing about
the construction of the chemical
elements is that it's so simple.

I suppose you could call it
"child's play".

So imagine these bubbles
are my universal chemistry set...

..and the single bubbles
could just be single protons.

That's the nucleus of the simplest
chemical element.

The element with a single proton
in its nucleus is hydrogen

and, from hydrogen,
you can make all the other elements.

The first stage
is to stick two protons together.

Ha-ha! Look at that!

That was two bubbles stuck together.

Now what happens when you stick
two protons together is one
of the protons turns into a neutron.

Now, that is called deuterium.

Deuterium is still
a form of hydrogen,

because it has only one proton
in its nucleus, and it's the number
of protons that defines the element.

It's only when two
deuterium nuclei are combined
that a new element is created.

Take two deuteriums and fuse them
together and you get a nucleus
for two protons and two neutrons.

That's helium,
the second simplest element.

Then, it's just a question of adding
more and more protons and neutrons.

Well, there is an
incredibly complicated nucleus.

That's about 12 things stuck
together, so that would be probably

carbon 12, which is
six protons and six neutrons.

And you can carry on building
more and more complex elements...

..all the way up to the heaviest
elements in the universe,

to uranium and beyond.

Simple, and beautiful, physics.

This process of building the
elements is called nuclear fusion.

It allows the simplest
of ingredients to create the
infinite variety of the universe.

But although this bubble metaphor
makes creating new elements
seem simple, it is,

in reality,
incredibly difficult to achieve.

So difficult that there's only one
place in nature that it happens.

It's in stars like our sun
that the elements are assembled.

They're the only places in the
universe hot enough and dense enough
to fuse atoms together.

Even then,
only a fraction of the star reaches
the extreme temperatures necessary.

The sun is 6,000 Celsius
at its surface, not nearly
hot enough to power fusion.

But deep below, where the
temperature reaches 15m degrees,

the sun fuses hydrogen into helium
at a furious rate.

Every second, it burns
600m tons of hydrogen.

As it does so, it releases the
huge amounts of heat and light
that brings our planet to life.

It is this process of converting
one element into another
that allows us to exist.

For all its power,
the sun only converts hydrogen,

the simplest element, into helium,
the next simplest.

But there are over 90 other
elements present in our universe,
so where did they all come from?

If the heavier elements are not
being made in stars like the sun,
then there must be somewhere else

in the universe
where they are assembled.

It's important to know

because it's the elements
beyond helium that give
our world its complexity,

and when it comes to
planet Earth and human beings,

there's one element that is
particularly important - carbon.

Life is completely
dependent on carbon.

I mean, I'm made of about a billion
billion billion carbon atoms, as is

every human being out there,
every living thing on the planet.

Imagine how many
carbon atoms that is.

So where does all
that carbon come from?

Well, it comes from the
only place in the universe where
elements are made - stars.

But in order for us to live,
a star must die.

Stars in the prime of their
lives, like our sun, are only
hot enough to make helium.

Forming the heavier elements
requires much higher temperatures.

Temperatures that can only be
reached at the end of a star's life.

Looking out into space,

you might think that the cosmos
is a constant, unchanging place.

That the stars will always be there.

But in fact, the stars are only
a temporary feature in the sky,

and though they may burn brightly

for many millions or
billions of years,

they can only live for
as long as they have a supply
of hydrogen to burn.

When a star runs out of hydrogen,
it begins to die,

but it doesn't go quietly.

Rather than cooling,

the star becomes much hotter,
until there's a sudden flash.

Then the star starts to expand.

Over tens of thousands of years,

it balloons to many hundreds
of times its previous size.

But in this bloated state,

the star is unable to maintain
its surface temperature.

As it cools, it takes
on the characteristic
colour of a dying star.

It has become a red giant.

These are pictures of a red
giant star in our galaxy,
a star called Betelgeuse.

Now, it's one of our nearest
neighbours in cosmic terms.

It's only about 600 light
years away, but it's the size
that's astonishing.

If you were to put the sun there,
then Venus would be about there

and the Earth about there, and
Mars here, and in fact you could

fit everything in the solar system
all the way out to Jupiter

inside the star.

Now, because it's so big, even
though it is 600 light years away,

you can see detail on its surface,

so these, these are sunspots
on the surface of Betelgeuse.

But it's not what's going on on the
surface that's really interesting.

To understand where carbon comes
from in the universe, we have to

understand what's going on deep
in the heart of the star.

Imagine this old prison in Rio
is a dying star like Betelgeuse.

Out there is the bright surface,
shining off into space.

As I descend deeper and deeper
into the prison,

the conditions would become hotter
and hotter and denser and denser,

until down there in the heart
in the star is the core,

and it's in there that all
the ingredients of life are made.

Deep in its core, the star
is fighting a futile battle
against its own gravity.

As it desperately tries to stop
itself collapsing under its own

weight, new elements are made
in a sequence of separate stages.

Stage one is while there is still
a supply of hydrogen to burn.

Whilst the star is burning hydrogen
to helium in the core, vast amounts

of energy are released and that
energy escapes, literally creating

an outward pressure which bounces
the force of gravity and,

well, it holds the star
up and keeps it stable.

But eventually, the hydrogen
in the core will run out

and at that point
the fusion reactions will stop,

no more energy will be released

and that outward pressure
will disappear.

Now, at that point, the core will
start to collapse very rapidly,

leaving a shell...

..of hydrogen
and helium behind.

Beneath this shell,
as the core collapses,

the temperature rises again

until, at 100 million degrees,

stage two starts and helium
nuclei begin to fuse together.

A helium fusion does two things.

Firstly, more energy is released
and so the collapse is halted.

But secondly, two more elements
are produced in that process...

..carbon.

Oxygen. Two elements vital for life.

So this is where all the carbon
in the universe comes from.

Every atom of carbon in my hand,

every atom of carbon in every
living thing on the planet

was produced in the heart
of a dying star.

But compared to the lifetime
of the star, the creation process
of carbon and oxygen is over

in a blink of an eye, because,
in only about a million years,

the supply of helium
in the core is used up

and for stars as massive as the sun,

that's where fusion stops,
because there isn't enough

gravitational energy to compress the
core any further and restart fusion.

But for massive stars
like Betelgeuse,

the fusion process can continue.

When the helium runs out,

gravity takes over again
and the collapse continues.

The temperature rises once more,
launching stage three,

in which carbon fuses
into magnesium, neon,

sodium, and aluminium.

And so it goes on.

Core collapse, followed
by the next stage of fusion

to create more elements, each stage
hotter and shorter than the last.

And, eventually, in a final stage
that lasts only a couple of days,

the heart of the star is
transformed into almost pure...

iron, whose chemical symbol is Fe,

and this is where the
fusion process stops.

In its millions of years of life,

the star has made
all the common elements,

the stuff that makes up 99%
of the Earth.

The core is now a solid ball
of those elements stacked on
top of each other in layers.

On the outside,
there's a shell of hydrogen.

Beneath it, a layer of helium.

Then carbon and oxygen, and all
the other elements, all the way

down to the very heart of the star.

And once that has fused
into solid iron, the star has
only seconds left to live.

When a star runs out of fuel,
then it can no longer release

energy through fusion reactions,

and then there's only one
thing that can happen.

In about the same amount of time it
takes this prison block to crumble,

the entire star falls in on itself.

This is the destiny that awaits
most of the stars in the universe.

Yet even the implosion
of the star only forges
the first 26 elements.

What of the remaining elements,

some of which are vital for life and
many of which we hold most precious?

These are the remote forests
of northern California.

100 years ago, this whole
area was teeming with people,
all in search of one element.

And the reason they were here
can still be found in the
original Sixteen To One Mine.

This once stood at the centre
of the California gold rush

and, thanks to a quirk of geology,
it continues to yield its precious
bounty over 100 years later.

You know, the unique thing
about this place is that
it sits right on the divide

between the North American
plate and the Pacific plate.

You see a divide there between
the rock and quartz,

then right up there
you can see the top of it.

Now, in between the faults,
this rock, the quartz, formed.

Then, 140 million years ago, in the
Jurassic period, when the dinosaurs

were running around
above our heads,

hot water welled up and flowed,
and that water deposited the gold

through the seams of quartz,
and so all the miners have to do...

and ALL they have to do...

is follow the seams of quartz, and
over hundreds of years they've

found vast amounts of
gold deposited there.

This is what all the fuss is about.

This is the gold as it
comes out of the ground,

and it's unusually pure
as gold goes.

This is about 85% pure gold, but
it could also be found like this,

and this is a gold nugget
that was found in a river,

on a river bed,
and it's a heavy piece of gold.

It's between about one and one
and a half ounces,

which means that at today's prices
it's worth about 2,000,

and it's that inherent value
that makes mines like
this worth operating.

But there's something a bit odd
about the value we attach to gold.

Throughout history,
people have gone to extraordinary
lengths to get their hands

on this most precious substance,
which is strange,

because it isn't particularly
useful for anything.

Most of the gold that's been
extracted throughout human history

has ended up as jewellery, but it
has got one thing going for it

and that's that it is
incredibly rare.

All the gold mined from the earth
in all of human history

would only just fill three
Olympic-size swimming pools.

And it's that scarcity
that makes gold valuable,

but gold is just one
of many rare elements.

There are over 60 elements
heavier than iron in the universe

and some are valuable,
like gold, silver, platinum.

Some are vital for life,
like copper and zinc,

and some are just useful,
like uranium, tin and lead.

But across the universe,

there are vanishingly small
amounts of those heavy elements.

The reason for that scarcity

is that creating
substantial amounts of the
heaviest elements requires

some of the rarest conditions
in the universe,

and we need to look
far into space to find them.

In a galaxy of 100 billion stars,
these conditions will exist

on average for less than a minute
in every century.

That's because they're only
created in the final death throes

of the very largest stars...

..stars of at least nine times
the mass of our sun.

Only they can reach the extreme
temperatures needed

to create large amounts
of the heavy elements.

Deep in the heart of the star,

the core finally
succumbs to gravity.

It falls in on itself
with enormous speed...

..and rebounds with colossal force.

As the blast wave collides with
the outer layers of the star,

it generates the highest
temperatures in the universe,
100 billion degrees.

These conditions last for just
15 seconds, but it's enough

to form the heaviest
elements like gold.

It's called a supernova...

..the most powerful explosion
in the universe.

It's quite a thought that
something as precious to us as
the gold in a wedding ring was

actually forged in the death
of a distant star,

millions of light years away,
billions of years ago.

Despite the rarity of supernovae,

when they do happen, they're the
most dramatic events in the sky.

This is a picture of
the Tarantula Nebula, which is
a cloud of gas and dust in

the Large Magellanic Cloud, which is
a satellite galaxy of the Milky Way,

and this is what it looks like on
any clear starry night of the year.

But on one night in 1987, the
Tarantula Nebula looked like that.

You can see that a new bright
star has appeared in the sky.

This is a supernova explosion, the
explosive death of a massive star,

and they're incredibly
violent cosmic events, as this
picture beautifully shows.

This is a galaxy about 55 million
light years away from Earth,

but this is a supernova explosion
in that galaxy.

You can see that it's shining
as brightly as the galactic core.

There may be a billion suns
in that core,

and one supernova can
shine as brightly as that.

Yet to really appreciate the scale
of these explosions, we would need

to see one up close, to see a
star die in our own galaxy,

the Milky Way.

Although on average
there's one big supernova

in each galaxy every century,

there hasn't been one
in the Milky Way since the
birth of modern science.

The last was in 1604,
so we're long overdue.

Astronomers are now searching
the skies for the star that is
most likely to go supernova.

And amongst the leading candidates
there's a familiar name.

This is the constellation of Orion
and this is Betelgeuse,

and we know it's extremely unstable

because it's dimmed by about 15%
in the last ten years.

Now,
astronomers think that this star
could go supernova at any moment.

That could mean any time in the
next million years but equally
it could explode tomorrow,

and Betelgeuse is only
600 light years away.

Now, when it goes, Betelgeuse
will be incredibly bright.

It'll be by far
the brightest star in the sky.

It may shine as brightly
as a full moon.

It will be almost a second sun
in the daylight.

In this single instant,
Betelgeuse will release more energy

than our sun will produce
in its entire lifetime.

As the star is torn apart,
it will fire out into space

all the elements that it created
in its life and death.

Those elements will spread out
to become a nebula,

a rich chemical cloud
drifting through space.

And at the heart of the nebula
will be a tiny beacon of light,

the remnant of a star once more
than a billion and a half kilometres

across that has been crushed
out of all recognition by gravity.

This is Betelgeuse,
the neutron star.

And it's how this once mighty star
will end its life.

Now, once Betelgeuse has gone,

the constellation of Orion
will look very different.

I mean there will just be
a hole in the sky

where that brilliant bright
red star once shone.

But it's in the deaths of old stars
that new stars are born

and it's very much like
the cycle of death and rebirth

here on earth but played out on a
cosmic scale, and you can see that

happening today in the constellation
of Orion

because in the sword handle
you can see this - the Orion nebula.

Now, it's nothing more than a misty
patch of light in the night sky

to the naked eye but if you look
more closely,

you see that
there is a lot more going on.

The Orion nebula is one of
the wonders of the universe.

Hidden in its clouds
are bright points of light.

These are new stars,
forming from the elements blown out
by supernova explosions,

new stars being born
from the remains of dead ones.

And it's from this universal process
of death and rebirth that we emerged

because it was in a nebula just
like this, five billion years ago,

that our sun was formed.

Around it,
a network of planets formed.

Among them was the Earth.

Everything we find on
the Earth today
also originated in that nebula.

But that is not
the end of this story
of how the universe created us.

Because when we look
deep into the nebula,

we don't just see
individual elements.

We see greater complexity,
the seeds of our own existence.

Well, this is a spectrum of the
light from the Orion nebula taken

by the Herschel space telescope,
so it really is a picture of light
from interstellar space.

You know, I wouldn't normally
show you a graph like this but this
is fascinating because what it shows

is that that gas cloud,
the Orion nebula, is not just
a cloud of elements.

There's complex chemistry
here happening in deep space
because each peak on this graph

corresponds to a different molecule
and there are some molecules present
that I suppose are quite obvious.

There's water and there's sulphur
dioxide. But there are also complex
carbon compounds in here. So there's

methanol, there's hydrogen cyanide,
there's formaldehyde, there's
dimethyl ether.

So what we're seeing here
is complex carbon chemistry
happening in deep space.

That carbon chemistry is the
beginning of the chemistry of life,

and there is surprising evidence
that this chemistry

may have had a direct impact
on the evolution of life on Earth.

That evidence comes from meteorites,

debris
left over from the formation of the

solar system that occasionally
collides with the earth.

One of the most productive
places for finding meteorites

is the Atacama desert
in the High Andes of South America.

This is a meteorite, a piece of rock
that fell to earth from somewhere

out there in the solar system,
and it is certainly older than
any rock you can see here.

It's probably older than any rock
you can find anywhere on Earth

because it formed
from the primordial gas cloud,
that nebula that collapsed

to form the sun and the planets over
four and a half billion years ago.

So it's incredibly ancient.

Now this is a slice,
a crosssection through a meteorite.

You see those little
brown areas in there?

Well, in those brown areas
we found amino acids,
the building blocks of proteins,

which are the building blocks
of me, the building blocks of life.
Incredibly complex carbon compounds.

So this says that the complex
carbon chemistry you need to
send you on the path to life

was happening out there in space
four and a half billion years ago.

So the first amino acids on earth,
the fundamental building blocks of
life, may have formed in the depths

of space and been delivered
to the earth on meteorites.

When we look out into space,
we are looking into our own origins.

Because we are truly
children of the stars.

And written into every atom and
every molecule of our bodies

is the entire history
of the universe from
the Big Bang to the present day.

Our story is
the story of the universe

and every piece of everyone,
of everything you love,

of everything you hate, of the thing
you hold most precious,

was assembled
by the forces of nature

in the first few minutes of the life
of the universe,

transformed in the hearts of stars
or created in their fiery deaths.

And when you die, those pieces
will be returned to the universe

in the endless cycle
of death and rebirth.

What a wonderful thing it is
to be a part of that universe!

And what a story.

What a majestic story.

♪ Words are flowing out
like endless rain into a paper cup

♪ They slither wildly as they
slip away across the universe

♪ Pools of sorrow, waves of joy

♪ Are drifting through my open mind

♪ Possessing and caressing me... ♪

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