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PROFESSOR BRIAN COX: Why are we here?
Where do we come from?
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00:00:16,558 --> 00:00:19,686
These are the most enduring
of güestions.
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And it's an essential part of human
nature to want to find the answers.
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00:00:29,404 --> 00:00:32,908
Now, we can trace our ancestry back
hundreds of thousands of years
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00:00:32,991 --> 00:00:34,868
to the dawn of humarıkiınd.
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00:00:34,952 --> 00:00:39,665
But in reality, our story extends
far further back in time.
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Our story starts with
the beginning of the universe.
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It began 13.7 billion years ago.
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And today, it's filled with over
a hundred billion galaxies,
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each containing
hundreds of billions of stars.
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00:01:04,898 --> 00:01:07,901
In this series,
I want to tell that story.
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Because ultimately,
we are part of the universe.
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So its story İis our story.
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This film is about
the stuff that makes us
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and where it all came from.
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Because understanding our own origins
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means uünderstanding
the lives of stars...
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...and how their catastrophic deaths
bring new life to the universe.
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Because every mountain,
every rock on this planet,
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every living thing,
every piece of you and me
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was forged in the furnaces of space.
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(BIRDS CHIRPING)
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(CHİLDREN LAUGHING)
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This is Pashupatinath in
the Nepalese capital city of Kathmandu.
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00:02:44,706 --> 00:02:48,460
And Hindus come here from
all öover India and Nepal
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to worship the god Shiva.
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In fact, that is Shiva's temple.
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Now, Shiva is the god of destruction.
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In the Hindu faith,
everything has to be destroyed
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so that new things can be created.
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And that's why pilgrims come here
to the barıks of the Bagmati River
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at the foot of Shiva's temple.
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The belief in this cycle of
creation and destruction
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lends Pashupatinath
an added significance.
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Many of these pilgrims will have come
here at the end of their lives,
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to die here and be cremated.
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Hindus believe in reincarnation, an
eternal seguence of death and rebirth.
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Cremation helps free the soul,
so it's ready for the next life.
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They also believe that
the physical elements of the body
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are released back to the world
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so they can be recycled
in the next stage of creation.
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It's an ancient belief
that touches on a deeper truth
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about how the universe works.
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Every civilization, every religion
across the world has a creation story.
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It tells of where we came from,
of how we came to be here
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and of what will happen when we die.
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Well, I have a different
creation story to tell,
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and it's based entirely on
physics and cosmology.
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Now, it can tell us what we're made of
and where we came from.
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In fact, it can tell us
what everything in the world
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is made of and where it came from.
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It also answers
that most basic of human needs,
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to feel part of something much bigger.
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Because to tell this story,
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you have to understand
the history of the universe.
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00:05:04,387 --> 00:05:07,766
And it teaches us that
the path to enlightenment
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is not an understanding
of our own lives and deaths,
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but the lives and deaths of the stars.
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My creation story is the story
of how we were made by the universe.
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It explains how every atom in our bodies
was formed not on Farth,
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but was created in the depths of space,
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through the epic life cycle
of the stars.
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And to understand that story,
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we will journey to the stars
in all their stages of life.
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This is where stars are born, a nebula,
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a stellar nursery,
where new stars burst into life.
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Those stars will burn
for billions of years,
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until their voracious hunger for fuel
forces them to blow up,
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to become giants
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hundreds of times the size of our sun.
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And when they die, stars go out with
the biggest bang in the universe.
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But to understand
how we came from the stars,
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we must begin our journey
much closer to home.
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Well, this is sunrise over Nepal
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and those are the tallest mountains
in the world, the Himalayas.
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I mean, every one of those peaks
is over six and a half thousand metres.
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What a spectacular sight.
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But it's incredible to think that just
a few tens of millions of years ago,
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those mountains were
something very different.
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The Himalayas haven't always
been mountains.
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We can find clues to their true origin
by looking at them more closely.
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This is Himalayan limestone,
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the rock out of which much of
this magnificent mountain range is made.
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Now, if you look closely, you can see
a kimd of chalky, granular structure.
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Because limestone is made primarily
out of the bodies,
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the shells of dead sea creatures,
of coral and polyps.
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And when they die, they are put under
immense pressures and sguashed
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and eventually form limestone.
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So the Himalayas
were once living creatures.
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Much of the rock in the Himalayas
was formed at the bottom of an ocean.
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And then over millions of years, it was
ralsed up to become these vast peaks.
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We've even found fossils
at the top of Mount Everest.
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It's a beautiful example of the endless
recycling of the Farth's resources
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that has been göorng on
since the dawn of time.
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And we are part of that system.
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Every atom in my body was
once part of something else.
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So an ancient tree
or a dinosaur or a rock,
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in fact, definitely a rock.
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And the reason that the rocks
of the Earth can become living things
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and then living things
will return to the rocks of the Earth
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is because everything is made
of the same basic ingredients.
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Those ingredients are
the chemical elemenits,
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the building blocks
of everything on Earth.
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Elements like hydrogen, helium, lithium,
beryllium, boron, carbon, nitrogen,
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öxygen, fluorine, neon,
sodium, magnesium,
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aluminium, silicon, phosphorus...
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Everything in the world is made up of
the same basic set of chemical elements,
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just assembled in different ways.
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So these mountains, the Himalayas,
are made of limestone.
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And that's calcium carbonate.
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Now, calcium, carbon and oxygen
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are three of the elements
that are vital for life.
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The calcium in my teeth and bones,
oöxygen in the air that I breathe
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and carbon in
every organic molecule in my body.
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Now, you're probably pretty familiar
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with those elements
in their combined forms,
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but you very rarely
see the elements on their own.
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There's a good reason
why many of the elements
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are not found in
their raw forms in nature.
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They are extremely reactive.
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This is sodium.
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As you can see, it's a silvery metal.
It's also guite reactive.
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In fact, it's so reactive
that when you drop it into water,
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you get a violent,
almost explosive, reaction.
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Which is all the more surprising
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when you think that
when combined with chlorine,
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this forms sodium chloride,
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salt, which is vital for life.
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Excellent.
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(LAUGHING)
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And that's why I love chemistry
almost as much as physics.
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It's this reactivity
that enables the elements
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to combine with öone another
to make new substances.
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MAN 1: İt's goöne.
MAN 2: Where the hell's it gone?
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(COX LAUGHING)
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That, in turn, has allowed the Farth
to develop its endless variety.
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And that vartety includes us.
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So to explain where we come from,
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we must also explain
where the elemenis come from.
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We now know that the Earth
is made of 92 chemical elements.
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And that's pretty amazing, if you think
of the complexity that we see around us.
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We also know that
everything beyond Earth,
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everything we can see in the universe,
is made of those same 92 elemenits.
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And notice that I didn't say
we think that's what they're made of.
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I said we know
that's what they're made of,
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because we carı prove it.
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The chemistry set we have on Farth
extends far beyond the planet.
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We have set foot on the moon
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and know that it's rich in
helium, silver and water.
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00:12:51,104 --> 00:12:54,440
We've sent robot landers
to our neighbouring planets
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and discovered that Mars
is rich in iron,
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which has combined with öoxygen
to form its familiar rusty red colour.
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00:13:05,952 --> 00:13:09,706
And we know that Venus'
thick atmosphere is full of sulphur.
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00:13:13,042 --> 00:13:16,296
We've sent spacecraft
to the edge of the solar system
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to discover that Neptune is rich
in organic molecules like methane.
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But what of the rest of the universe?
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It seems impossible that we could
discover what the stars are made of
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because they're so far away.
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00:13:39,819 --> 00:13:42,905
Even the nearest star, Proxima Centauri,
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is ten thousand times
more distant than Neptune,
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4.2 light years from Farth.
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00:13:57,670 --> 00:14:03,301
And the nearest galaxy, Andromeda,
is another 2.5 million light years away.
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00:14:07,180 --> 00:14:09,432
Yet despite these vast distances,
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these alien worlds are
constantliy sending us signals,
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telling us exactly
what they are made of.
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00:14:17,774 --> 00:14:20,193
Our only contact with the distant stars
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is their light that's journeyed
across the universe to reach us.
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And encoded in that light
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is the key to understanding
what the universe is made of.
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00:14:29,619 --> 00:14:33,331
And it's all down to a particular
property of the chemical elements.
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You see, when you heat the elements,
when you burn them,
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then they give off light.
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And each element gives off
its own unigue set of colours.
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So this is strontium and it burns
with a beautiful red colour.
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Sodium is yellow.
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Potassium is lilac.
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And copper is blue.
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Fach element has
its own characteristic colour.
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00:15:17,375 --> 00:15:21,129
It's this property that telis us
what the stars are made of.
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00:15:24,298 --> 00:15:26,092
But it's a little more complicated
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than simply looking at the colour
of the light that each star emits.
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You can see why by looking at the light
From our nearest star, the sun.
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This is a spectrum of
the light taken from our sun.
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And at first glance
it looks very familiar,
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it looks like a stretched-out rainbow,
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because that's exactly
what a rainbow is,
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it's the spectrum of the light
from the sun in the sky.
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But if you look a bit more closely,
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then you see that
this spectrum is covered in black lines.
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00:16:01,711 --> 00:16:04,172
These are called absorption lines.
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00:16:05,882 --> 00:16:07,884
Fach element within our sun
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00:16:07,967 --> 00:16:10,511
not only emits light
of a certain colour,
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00:16:10,595 --> 00:16:14,557
it also absorbs light
of the same colour.
194
00:16:14,640 --> 00:16:17,393
By looking for these black lines
in the sun's light,
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00:16:17,477 --> 00:16:22,064
we can simply read off a list of its
constituent elements, like a barcode.
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00:16:23,149 --> 00:16:25,651
For example, these two black lines
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in the yellow bit of the spectrum
are sodium.
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00:16:28,779 --> 00:16:34,160
You can see iron.
Right down here, you can see hydrogen.
199
00:16:34,660 --> 00:16:38,080
So by looking at these lines
in precise detail,
200
00:16:38,164 --> 00:16:42,293
you can work out exactly
what elements are present in the sun.
201
00:16:42,376 --> 00:16:45,296
And it turns out that
that's about 7096 hydrogen,
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00:16:45,379 --> 00:16:48,758
289 helium and 294 the rest.
203
00:16:48,841 --> 00:16:51,219
And you can do this
not only for the sun,
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00:16:51,260 --> 00:16:55,139
but for any of the stars
you can see in the sky,
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00:16:55,556 --> 00:16:58,976
and you can measure exactly
what they're made of.
206
00:17:03,147 --> 00:17:08,319
So that star there is Polaris,
the pole star. And you can see that
207
00:17:08,402 --> 00:17:12,990
because all the other stars in the
night sky appear to rotate around it.
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00:17:13,074 --> 00:17:16,869
Now, it's 430 light years away.
209
00:17:19,872 --> 00:17:22,250
But we know just by looking at the light
210
00:17:22,333 --> 00:17:26,212
that it has about the same
heavy element abundance as our sun,
211
00:17:28,923 --> 00:17:32,843
but it's got markedly less carbon
and a lot more nitrogen.
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00:17:38,766 --> 00:17:41,352
And the same applies for other stars.
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00:17:42,937 --> 00:17:46,440
Vega, the second brightest star
in the northern sky,
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00:17:46,524 --> 00:17:49,986
has only about a third of
the metal content of our sun,
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00:17:52,154 --> 00:17:54,699
whereas other stars are metal-heavy.
216
00:17:58,703 --> 00:18:03,749
Sirius, the dog star, contains
three times as much iron as the sun.
217
00:18:06,752 --> 00:18:10,172
And Proxima Centauri
is rich in magnesium.
218
00:18:14,635 --> 00:18:17,680
But although the guantities of
the elements may vary,
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00:18:17,763 --> 00:18:20,016
wherever we look across space,
220
00:18:20,099 --> 00:18:24,228
we only ever find the same
92 elements that we find on Farth.
221
00:18:29,317 --> 00:18:33,779
We are made of the same stuff
as the stars and the galaxies.
222
00:18:41,370 --> 00:18:44,123
But where did all this matter come from?
223
00:18:46,626 --> 00:18:50,338
And how did it become
the complex universe we see today?
224
00:19:13,944 --> 00:19:16,489
In order to understand
where we came from,
225
00:19:16,572 --> 00:19:18,824
we have to understand events
that happened
226
00:19:18,908 --> 00:19:22,453
in the first few seconds
of the life of the universe.
227
00:19:23,412 --> 00:19:27,750
You see, when the universe began,
it was unimaginably hot and dense.
228
00:19:27,833 --> 00:19:31,712
We literally don't have
the scientific language to describe it.
229
00:19:32,546 --> 00:19:36,008
But it was,
in a very real sense, beautiful.
230
00:19:36,550 --> 00:19:41,055
There was no structure,
there was certainly no matter.
231
00:19:41,138 --> 00:19:45,726
It was exactly the same,
whichever way you look at it.
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00:19:50,690 --> 00:19:53,776
We can get some idea
of how the universe developed
233
00:19:53,859 --> 00:19:56,237
from this state of pure symmetry
234
00:19:57,780 --> 00:20:01,867
by looking at the behaviour of water
in this remarkable landscape.
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00:20:04,412 --> 00:20:08,666
These are the El Tatio geysers,
high in the Chilean Andes.
236
00:20:11,460 --> 00:20:14,088
As the boiling water
bubbles up through the ground
237
00:20:14,171 --> 00:20:16,382
to meet the freezing mountain air,
238
00:20:16,465 --> 00:20:20,845
water can be found in
all three of its natural phases,
239
00:20:20,928 --> 00:20:23,514
vapour, liguid and ice.
240
00:20:27,601 --> 00:20:31,856
In its hottest state,
water is, like the early universe,
241
00:20:31,939 --> 00:20:34,567
an undifferentiated cloud.
242
00:20:36,527 --> 00:20:40,489
But as it cools,
it suddenly behaves very differentiy.
243
00:20:43,242 --> 00:20:44,785
You see, if you look at
a cloud of steam,
244
00:20:44,869 --> 00:20:48,372
it looks the same from every direction,
245
00:20:49,081 --> 00:20:55,045
but as it cools down, as it lands on
this plate of freezing cold glass,
246
00:20:55,588 --> 00:21:01,135
then it immediately crystallises out,
it turns into solid water, ice.
247
00:21:04,722 --> 00:21:06,557
As the ice crystals form,
248
00:21:06,640 --> 00:21:10,311
the symmetry of the water vapour
disappears from view
249
00:21:10,394 --> 00:21:13,856
and complex,
beautiful structure emerges.
250
00:21:18,277 --> 00:21:21,906
In the same way, we think that
the universe, as it cooled,
251
00:21:21,989 --> 00:21:26,660
went through a series of these events
where structure emerged.
252
00:21:26,702 --> 00:21:28,454
One of the most important
253
00:21:28,537 --> 00:21:31,665
was about a billionth of a second
after the Big Bang.
254
00:21:34,251 --> 00:21:39,340
In that moment, an important part of
the symmetry of the universe was broken.
255
00:21:43,177 --> 00:21:46,013
Known as electroweak symmetry breaking,
256
00:21:46,096 --> 00:21:50,476
this was the moment when
subatomic particles acguired mass,
257
00:21:50,559 --> 00:21:52,812
substance for the first time.
258
00:21:53,854 --> 00:21:55,981
Amongst them were the guarks.
259
00:21:59,026 --> 00:22:00,903
As the universe continued to cool,
260
00:22:00,986 --> 00:22:06,158
those guarks joined together
to form larger, more complex structures
261
00:22:06,242 --> 00:22:08,410
called protons and neutrons.
262
00:22:09,537 --> 00:22:12,790
Way before the universe
was a minute old,
263
00:22:12,873 --> 00:22:18,045
the guarks had been locked away
inside the protons and the neutrons.
264
00:22:18,462 --> 00:22:22,633
They are the building blocks
of all atomic nuclei,
265
00:22:22,716 --> 00:22:25,261
the building blocks of the elements.
266
00:22:30,182 --> 00:22:33,811
These same protons and neutrons
are with us to this day.
267
00:22:34,436 --> 00:22:38,482
They form the hearts,
the nuclei, of all atoms.
268
00:22:51,036 --> 00:22:54,665
Just a few seconds after
the beginning of the universe,
269
00:22:54,748 --> 00:22:58,878
the fundamental building blocks
of everything had been created.
270
00:23:03,716 --> 00:23:05,342
Well, it sounds ridiculous.
271
00:23:05,426 --> 00:23:08,804
The fact that everything you need
to make up me
272
00:23:08,888 --> 00:23:11,765
and everything on planet Earth
273
00:23:11,849 --> 00:23:15,769
and, in fact, every star and
every galaxy in the sky
274
00:23:16,020 --> 00:23:20,524
was there after the first minutes
in the life of the universe.
275
00:23:20,608 --> 00:23:22,067
It's almost unbelievable,
276
00:23:22,151 --> 00:23:25,237
but we have extremely strong
experimental evidence
277
00:23:25,321 --> 00:23:28,741
to suggest that that is
the way that it is.
278
00:23:29,700 --> 00:23:34,038
Well, from that point on,
it was just, in a sense,
279
00:23:34,121 --> 00:23:41,086
a process of assembling those bits
into more and more complex things.
280
00:23:41,670 --> 00:23:45,341
That is an incredibly
fascinating story in itself.
281
00:24:08,906 --> 00:24:10,157
To teli that story,
282
00:24:10,240 --> 00:24:14,703
we must look deep inside the atom,
to the nucleus at its centre.
283
00:24:15,829 --> 00:24:20,042
Here we can see how
protons and neutrons are assembled
284
00:24:20,125 --> 00:24:23,087
to build up the 92 different elements.
285
00:24:25,172 --> 00:24:29,468
Now, the wonderful thing about the
construction of the chemical elements
286
00:24:29,551 --> 00:24:31,470
is that it's so simple.
287
00:24:32,179 --> 00:24:34,932
I suppose you could
call it child's play.
288
00:24:42,940 --> 00:24:46,860
So imagine these bubbles are
my universal chemistry set.
289
00:24:48,070 --> 00:24:52,741
And the single bubbles
would just be single protons.
290
00:24:52,825 --> 00:24:56,161
That's the nucleus
of the simplest chemical element.
291
00:24:58,622 --> 00:25:03,085
The element with a single proton
in its nucleus is hydrogen.
292
00:25:03,168 --> 00:25:06,672
And from hydrogen,
you can make all the other elements.
293
00:25:09,091 --> 00:25:12,803
The first stage
is to stick two protons together.
294
00:25:15,556 --> 00:25:20,269
(LAUGHS) Look at that!
That was two bubbles stuck together.
295
00:25:20,352 --> 00:25:23,063
Now, what happens when you stick
two protons together is
296
00:25:23,147 --> 00:25:25,524
one of the protons turns into a neutron.
297
00:25:26,567 --> 00:25:28,777
And that is called deuterium.
298
00:25:31,321 --> 00:25:33,741
Devterium is still a form of hydrogen,
299
00:25:33,782 --> 00:25:36,952
because it has only one proton
in its nucleus
300
00:25:37,036 --> 00:25:40,622
and it is the number of protons
that defines the element.
301
00:25:41,248 --> 00:25:44,626
It's öonly when
two deuterium nuclei are combined
302
00:25:44,710 --> 00:25:46,962
that a new element is created.
303
00:25:47,504 --> 00:25:50,466
Take two deuteriums
and fuse them together
304
00:25:50,924 --> 00:25:54,428
and you get a nucleus with
two protons and two neutrons.
305
00:25:55,137 --> 00:25:58,015
That's helium,
the second simplest element.
306
00:26:01,060 --> 00:26:05,606
And then it's just a guestion of adding
more and more protons and neutrons.
307
00:26:08,233 --> 00:26:10,152
Well, there's an incredibly
complicated nucleus.
308
00:26:10,235 --> 00:26:12,404
That's about 12 things stuck together.
309
00:26:12,488 --> 00:26:17,618
So that would be probably carbon-12,
which is six protons and six neutrons.
310
00:26:19,745 --> 00:26:24,124
And you can carry on building
more and more complex elements
311
00:26:25,667 --> 00:26:30,214
all the way up to
the heaviest element in the universe,
312
00:26:30,297 --> 00:26:32,508
to uranium and beyond.
313
00:26:33,133 --> 00:26:35,677
Simple and beautiful physics.
314
00:26:44,645 --> 00:26:49,399
This process of building the elements
is called nuclear fusion.
315
00:26:50,025 --> 00:26:52,319
It allows the simplest of ingredients
316
00:26:52,402 --> 00:26:55,531
to create the infinite variety
of the universe.
317
00:26:58,033 --> 00:27:02,579
But although this bubble metaphor makes
creating new elements seem simple,
318
00:27:02,663 --> 00:27:05,791
it is in reality incredibiy
difficult to achieve...
319
00:27:11,630 --> 00:27:16,135
so difficult that there's only place
in nature that it happens.
320
00:27:30,232 --> 00:27:33,902
İt's in stars like our sun
that the elements are assembled.
321
00:27:35,279 --> 00:27:39,324
They are the öonly places in the universe
hot enough and dense enough
322
00:27:39,408 --> 00:27:41,410
to fuse atoms together.
323
00:27:41,910 --> 00:27:44,663
Even then, only a fraction of the star
324
00:27:44,746 --> 00:27:47,666
reaches the extreme
temperatures necessary.
325
00:27:48,333 --> 00:27:51,795
The sun is 6000 degrees Celsius
at its surface,
326
00:27:52,296 --> 00:27:54,923
not nearly hot enough to power fusion.
327
00:28:01,305 --> 00:28:06,143
But deep below, where the temperature
reaches 15 million degrees,
328
00:28:06,226 --> 00:28:11,106
the sun fuses hydrogen into helium
at a furfous rate.
329
00:28:11,190 --> 00:28:16,236
Every second it burns
600 million tonnes of hydrogen.
330
00:28:21,950 --> 00:28:26,788
As it does so, it releases
the huge amounts of heat and light
331
00:28:27,456 --> 00:28:29,708
that brings our planet to life.
332
00:28:36,006 --> 00:28:39,593
It is this process of
converting öone element into another
333
00:28:39,676 --> 00:28:41,637
that allows us to exist.
334
00:28:45,515 --> 00:28:48,227
But for all its power,
the sun only converts
335
00:28:48,310 --> 00:28:52,648
hydrogen, the simplest element,
into helium, the next simplest.
336
00:28:53,398 --> 00:28:57,361
But there are over 90 other elements
present in our universe.
337
00:28:57,444 --> 00:28:58,820
So where did they all come from?
338
00:29:01,156 --> 00:29:04,993
Hf the heavier elements are not
being made in stars like the sun,
339
00:29:05,077 --> 00:29:09,206
then there must be somewhere else in
the universe where they are assembled.
340
00:29:09,289 --> 00:29:10,832
It's important to know,
341
00:29:10,916 --> 00:29:15,837
because it's the elements beyond helium
that give our world its complexity.
342
00:29:15,921 --> 00:29:18,840
And when it comes to planet Farth
and human beings,
343
00:29:18,924 --> 00:29:22,261
there's öone element
that is particularly important.
344
00:29:22,344 --> 00:29:23,553
Carbon.
345
00:29:24,304 --> 00:29:27,266
Life is completely dependent on carbon.
346
00:29:27,933 --> 00:29:33,730
I mean, I'm made of about a billion
billion billon carbon atoms,
347
00:29:33,814 --> 00:29:39,611
as is every human being out there,
every living thing on the planet.
348
00:29:39,695 --> 00:29:42,281
Imagine how many carbon atoms that is.
349
00:29:42,364 --> 00:29:44,783
So where does
all that carbon come from?
350
00:29:44,866 --> 00:29:49,663
Well, it comes from the only place in
the universe where elements are made.
351
00:29:49,746 --> 00:29:50,998
Stars.
352
00:29:51,540 --> 00:29:55,711
But in order for us tolive,
a star must die.
353
00:29:59,339 --> 00:30:02,634
Stars in the prime of their lives,
like our sun,
354
00:30:02,718 --> 00:30:05,220
are önly hot enough to make helium.
355
00:30:06,805 --> 00:30:10,767
Forming the heavier elements
reguires much higher temperatures,
356
00:30:12,728 --> 00:30:16,815
temperatures that can only be reached
at the end of a star's life.
357
00:30:22,362 --> 00:30:24,072
Looking out into space,
358
00:30:24,156 --> 00:30:28,535
you miğht think that the cosmos
is a constant, unchanging place,
359
00:30:28,618 --> 00:30:31,079
the stars will always be there.
360
00:30:32,414 --> 00:30:37,127
But in fact, the stars are only
a temporary feature in the sky.
361
00:30:37,210 --> 00:30:41,840
And though they may burn brightiy
for many millions or billiorns of years,
362
00:30:41,923 --> 00:30:46,345
they can only live for as long as
they have a supply of hydrogen to burn.
363
00:30:48,388 --> 00:30:51,975
When a star runs out of hydrogen,
it begins to die.
364
00:30:53,143 --> 00:30:55,187
But it doesn't go guretiy.
365
00:30:57,939 --> 00:31:01,651
Rather than cooling,
the star becomes much hotter,
366
00:31:01,735 --> 00:31:03,904
until there's a sudden flash.
367
00:31:04,946 --> 00:31:07,324
Then the star starts to expand.
368
00:31:11,495 --> 00:31:13,413
Over tens of thousands of years,
369
00:31:13,497 --> 00:31:17,417
it balloons to many hundreds of times
its previous size.
370
00:31:19,961 --> 00:31:21,838
But in this bloated state,
371
00:31:21,922 --> 00:31:24,925
the star is unable to
mailntain its surface temperature.
372
00:31:28,136 --> 00:31:33,016
As it cools, it takes on the
characteristic colour of a dying star.
373
00:31:35,060 --> 00:31:37,104
It has become a red giant.
374
00:31:44,778 --> 00:31:48,115
These are pictures of
a red giant star in our galaxy,
375
00:31:48,198 --> 00:31:49,866
a star called Betelgeuse.
376
00:31:49,950 --> 00:31:52,494
Now, it's öone of our nearest neighbours
in cosmic terms,
377
00:31:52,577 --> 00:31:55,330
it's only about 600 light years away.
378
00:31:56,039 --> 00:31:58,291
But it's the size that's astonishing.
379
00:31:58,583 --> 00:32:03,130
If you were to put the sun there,
then Venus would be about there,
380
00:32:03,213 --> 00:32:06,091
and the Earth about there,
and Mars here.
381
00:32:06,174 --> 00:32:09,177
And in fact, you could fit
everything in the solar system
382
00:32:09,261 --> 00:32:13,140
all the way out to Jupiter
inside the star.
383
00:32:14,015 --> 00:32:18,645
Now, because it's so big,
even though it is 600 light years away,
384
00:32:18,728 --> 00:32:21,022
you can see detail on its surface.
385
00:32:21,106 --> 00:32:24,860
So these, these are sunspots on
the surface of Betelgeuse.
386
00:32:25,485 --> 00:32:29,990
But it's not what's going on on
the surface that's really interesting.
387
00:32:30,073 --> 00:32:33,785
To understand where carbon
comes from in the universe,
388
00:32:33,869 --> 00:32:38,165
we have to understand what's going on
deep in the heart of the star.
389
00:33:02,606 --> 00:33:07,068
Imagine this old prison in Rio
is a dying star like Betelgeuse.
390
00:33:07,819 --> 00:33:12,949
Out there is the bright surface,
shining off into space.
391
00:33:13,325 --> 00:33:17,078
As I descend deeper and deeper
into the prison,
392
00:33:17,162 --> 00:33:22,834
the conditions will become hotter
and hotter and denser and denser,
393
00:33:22,918 --> 00:33:28,298
until down there, in the heart
of the star, is the core,
394
00:33:28,632 --> 00:33:33,136
and it's in there that all
the ingredients of life are made.
395
00:33:36,765 --> 00:33:37,933
Deep in its core,
396
00:33:38,016 --> 00:33:42,229
the star is fighting a futile battle
agalrnst its own gravity.
397
00:33:44,397 --> 00:33:48,860
As it desperately tries to stop itself
collapsing under its own weight
398
00:33:48,944 --> 00:33:52,447
new elements are made
in a seguence of separate stages.
399
00:33:58,662 --> 00:34:02,624
Stage one is while there is still
a supply of hydrogen to burn.
400
00:34:10,340 --> 00:34:13,843
Whilst the star is burning hydrogen
to helium in the core,
401
00:34:13,927 --> 00:34:18,056
vast amounts of energy are released,
arıd that energy escapes,
402
00:34:18,139 --> 00:34:23,395
literally creating an outward pressure
which balances the force of gravity
403
00:34:23,478 --> 00:34:27,065
and, well, it holds the star up
and keeps it stable.
404
00:34:27,732 --> 00:34:31,152
But eventually the hydrogen in the core
will run out
405
00:34:31,486 --> 00:34:34,823
and at that point,
the fusion reactions will stop,
406
00:34:35,407 --> 00:34:37,242
no more energy will be released,
407
00:34:37,325 --> 00:34:40,203
and that outward pressure
will disappear.
408
00:34:40,620 --> 00:34:45,500
Now, at that point, the core will start
to collapse very rapidly,
409
00:34:45,584 --> 00:34:47,168
leaving a shell
410
00:34:50,797 --> 00:34:53,550
of hydrogen and helium behind.
411
00:34:58,471 --> 00:35:01,349
Beneath this shell
as the core collapses,
412
00:35:01,433 --> 00:35:03,435
the temperature rises again,
413
00:35:05,353 --> 00:35:09,524
until, at a hundred million degrees,
stage two starts
414
00:35:10,066 --> 00:35:13,028
and helium nuclei
begğin to fuse together.
415
00:35:21,453 --> 00:35:23,955
Now, helium fusion does two things.
416
00:35:24,039 --> 00:35:29,252
Firstly, more energy is released,
and so the collapse is halted.
417
00:35:29,919 --> 00:35:34,549
But secondly, two more elements
are produced in that process.
418
00:35:36,676 --> 00:35:38,219
Carbon,
419
00:35:41,348 --> 00:35:44,976
oxygen. Two elements vital for life.
420
00:35:45,977 --> 00:35:50,523
So this is where all the carbon
in the universe comes from.
421
00:35:50,857 --> 00:35:53,860
Every atom of carbon in my hand,
422
00:35:53,902 --> 00:35:59,157
every atom of carbon in
every living thing on the planet
423
00:35:59,240 --> 00:36:02,661
was produced in
the heart of a dying star.
424
00:36:05,121 --> 00:36:07,248
Now, compared to the lifetime of a star,
425
00:36:07,332 --> 00:36:12,671
the creation process of carbon and
oxygen is over in the blink of an eye,
426
00:36:12,754 --> 00:36:15,632
because in only about a million years,
427
00:36:15,715 --> 00:36:19,260
the supply of helium
in the core is used up,
428
00:36:19,302 --> 00:36:23,848
and for stars as massive as the sun,
that's where fusion stops,
429
00:36:23,932 --> 00:36:26,893
because there isn't
enough gravitational energy
430
00:36:26,976 --> 00:36:30,689
to compress the core any further
and restart fusion.
431
00:36:31,106 --> 00:36:36,903
But for massive stars like Betelgeuse,
the fusion process can continue.
432
00:36:42,867 --> 00:36:44,869
When the helium runs out
433
00:36:44,953 --> 00:36:48,748
gravity takes over again
and the collapse continues.
434
00:36:51,084 --> 00:36:54,713
The temperature rises önce more,
launching stage three,
435
00:36:56,297 --> 00:37:01,553
in which carbon fuses into magnesium,
neon, sodium and aluminium.
436
00:37:03,054 --> 00:37:06,015
And so it goes on, core collapse,
437
00:37:06,099 --> 00:37:09,811
followed by the next stage of fuston
to create more elemenis,
438
00:37:10,770 --> 00:37:14,566
each stage hotter and shorter
than the last.
439
00:37:17,610 --> 00:37:22,449
And eventually, in a final stage
that lasts only a couple of days,
440
00:37:22,866 --> 00:37:29,205
the heart of the star is transformed
into almost pure iron,
441
00:37:31,166 --> 00:37:33,752
whose chemical symbol is Fe.
442
00:37:34,085 --> 00:37:36,796
This is where the fusion process stops.
443
00:37:39,257 --> 00:37:41,593
In its millions of years of life,
444
00:37:41,676 --> 00:37:44,554
the star has made
all the common elements,
445
00:37:45,722 --> 00:37:49,017
the stuff that makes up
9926 of the Farth.
446
00:37:51,019 --> 00:37:54,022
The core is now a solid ball
of those elemenits,
447
00:37:54,105 --> 00:37:56,816
stacked on top of each other in layers.
448
00:37:58,902 --> 00:38:01,863
On the outside,
there's a shell of hydrogen,
449
00:38:02,655 --> 00:38:05,658
beneath it a layer of helium,
450
00:38:05,700 --> 00:38:09,245
then carbon and öoxygen
and all the other elements,
451
00:38:09,329 --> 00:38:12,415
all the way down to
the very heart of the star.
452
00:38:13,708 --> 00:38:16,419
And once that has fused into solid iron,
453
00:38:17,212 --> 00:38:19,881
the star has only seconds left to live.
454
00:38:22,300 --> 00:38:24,052
When a star runs out of fuel,
455
00:38:24,135 --> 00:38:28,056
then it can no longer release energy
through fusion reactions,
456
00:38:28,640 --> 00:38:31,142
and then there's only one thing
that can happen.
457
00:38:46,783 --> 00:38:50,954
In about the same amount of time
it takes this prison block to crumble,
458
00:38:51,037 --> 00:38:53,998
the entire star falls in on itself.
459
00:39:02,799 --> 00:39:07,178
This is the destiny that awaits
most of the stars in the universe.
460
00:39:12,100 --> 00:39:17,063
Yet even the implosion of a star
only forges the first 26 elemenis.
461
00:39:19,148 --> 00:39:23,278
What of the remaining elements,
some of which are vital for life,
462
00:39:23,361 --> 00:39:26,114
and many of which we hold most precious?
463
00:39:30,660 --> 00:39:32,495
(BIRDS CHIRPING)
464
00:39:45,383 --> 00:39:48,720
These are the remote forests
of northern California.
465
00:39:51,055 --> 00:39:55,059
A hundred years ago,
this whole area was teeming with people,
466
00:39:55,101 --> 00:39:57,353
all in search of öone element.
467
00:40:04,152 --> 00:40:06,779
And the reason they were here
can still be found
468
00:40:06,863 --> 00:40:09,240
in the Original Sixteen to One mine.
469
00:40:13,119 --> 00:40:17,582
This once stood at the centre
of the Califormia gold rush.
470
00:40:18,416 --> 00:40:20,418
And tharıks to a gülrk of geology,
471
00:40:20,460 --> 00:40:24,797
it continues to yield its precious
bounty over a hundred years later.
472
00:40:26,466 --> 00:40:32,388
The unigue thing about this place
is that it sits right on the divide
473
00:40:32,472 --> 00:40:36,225
between the North American plate
anıd the Pacific plate.
474
00:40:36,309 --> 00:40:41,230
You see a divide there,
between the rock and guartz.
475
00:40:41,314 --> 00:40:44,233
And then right up there
you can see the top ofit.
476
00:40:44,317 --> 00:40:48,321
Now, in between the faults,
this rock, the guartz, formed.
477
00:40:48,404 --> 00:40:51,950
Then 140 million years ago,
in the Jurassic period,
478
00:40:52,033 --> 00:40:56,287
when the dinosaurs were
running around above our heads,
479
00:40:56,371 --> 00:40:59,290
hot water welled up and flowed.
480
00:40:59,374 --> 00:41:04,963
And that water deposited the gold
through the seams of guartz.
481
00:41:05,046 --> 00:41:08,132
And so, all the miners have to do,
482
00:41:08,216 --> 00:41:11,636
all they have to do
is follow the seams of guartz,
483
00:41:11,719 --> 00:41:16,516
and over hundreds of years they've found
vast amounts of gold deposited there.
484
00:41:32,365 --> 00:41:34,659
Well, this is what
all the fuss is about.
485
00:41:34,701 --> 00:41:38,621
This is the gold
as it comes out of the ground.
486
00:41:38,705 --> 00:41:43,918
And it's unusually pure, as gold goes.
This is about 8596 pure gold.
487
00:41:44,544 --> 00:41:47,130
But it can also be foundlike this.
488
00:41:47,213 --> 00:41:51,467
And this is a gold nugget that was
found in a river, on a riverbed.
489
00:41:52,051 --> 00:41:54,303
And it's a heavy piece of gold,
490
00:41:54,387 --> 00:41:56,764
it's between about one
and one and a half ounces,
491
00:41:57,140 --> 00:42:01,686
which means that at today's prices,
it's worth about $2,000.
492
00:42:02,520 --> 00:42:07,442
And it's that inherent value that makes
mines like this worth operating.
493
00:42:10,278 --> 00:42:11,946
(PIANO PLAYING)
494
00:42:23,041 --> 00:42:27,587
But there's something a bit odd
about the value we attach to gold.
495
00:42:27,670 --> 00:42:30,798
Throughout history, people have
göne to extraordinary lengths
496
00:42:30,882 --> 00:42:34,218
to get their hands on
this most precious substance.
497
00:42:35,053 --> 00:42:38,848
Which is strange, because it isn't
particularly useful for anything.
498
00:42:40,349 --> 00:42:43,519
Most of the gold that's been
extracted throughout human history
499
00:42:43,603 --> 00:42:45,646
has ended up as jewellery.
500
00:42:45,980 --> 00:42:51,360
But it has got one thing going for it,
and that's that it is incredibly rare.
501
00:42:52,653 --> 00:42:56,282
All the göld mined from the Farth
in all of human history
502
00:42:56,783 --> 00:43:00,411
would only just fill
three Olympic-sized swimming pools.
503
00:43:03,206 --> 00:43:06,292
And it's that scarcity
that makes gold valuable.
504
00:43:07,460 --> 00:43:10,379
But gold is just one of
many rare elemenits.
505
00:43:12,757 --> 00:43:16,302
There over 60 elements
heavier than iron in the universe.
506
00:43:16,594 --> 00:43:20,890
Some are valuable like gold,
silver, platinum.
507
00:43:21,349 --> 00:43:25,144
Some are vital for life,
like copper and zinc.
508
00:43:25,686 --> 00:43:30,108
And some are just useful.
Like uranium, tin and lead.
509
00:43:30,775 --> 00:43:32,610
But across the universe,
510
00:43:32,693 --> 00:43:36,447
there are vanishingly small amounts
of those heavy elements.
511
00:43:38,241 --> 00:43:39,951
The reason for that scarcity
512
00:43:40,034 --> 00:43:43,663
is that creating substantial amounts
of the heaviest elements
513
00:43:43,746 --> 00:43:47,250
reguires some of
the rarest conditions in the universe.
514
00:43:48,209 --> 00:43:51,379
And we need to look far into space
to find them.
515
00:43:53,965 --> 00:43:56,509
In a galaxy of a hundred billion stars,
516
00:43:56,759 --> 00:44:01,931
these conditions will exist, on average,
for less than a minute in every century.
517
00:44:09,313 --> 00:44:11,440
That's because they are only created
518
00:44:11,524 --> 00:44:14,986
in the final death throes
of the very largest stars,
519
00:44:17,905 --> 00:44:21,117
stars of at least
nine times the mass of our sun.
520
00:44:23,452 --> 00:44:26,664
Only they can reach
the extreme temperatures needed
521
00:44:26,747 --> 00:44:29,750
to create large amounts
of the heavy elements.
522
00:44:36,048 --> 00:44:40,469
Deep in the heart of the star,
the core finally succumbs to gravity.
523
00:44:47,476 --> 00:44:50,396
1t falls in on itself
with enormous speed...
524
00:44:58,821 --> 00:45:01,699
and rebounds with colossal force.
525
00:45:09,832 --> 00:45:13,377
As the blast wave collides with
the outer layers of the star,
526
00:45:13,461 --> 00:45:16,756
it generates the highest temperatures
in the universe,
527
00:45:16,839 --> 00:45:18,925
a hundred billion degrees.
528
00:45:22,053 --> 00:45:25,181
These conditions last
for just 15 seconds,
529
00:45:25,223 --> 00:45:28,893
but it's enough to form
the heaviest elemenits, like gold.
530
00:45:36,025 --> 00:45:37,985
It's called a supernova,
531
00:45:39,820 --> 00:45:42,740
the most powerful explosion
in the universe.
532
00:45:50,790 --> 00:45:54,877
You know, it's guite a thought
that something as precious to us
533
00:45:54,961 --> 00:45:57,421
as the gold in a wedding ring
534
00:45:57,505 --> 00:46:00,716
was actually forged in
the death of a distant star
535
00:46:00,800 --> 00:46:04,470
millions of light years away,
billions of years ago.
536
00:46:09,100 --> 00:46:11,644
Despite the rarity of supernovae,
537
00:46:11,727 --> 00:46:15,815
when they do happen, they are
the most dramatic events in the sky.
538
00:46:17,400 --> 00:46:19,944
This is a picture of
the Tarantula Nebula,
539
00:46:20,027 --> 00:46:22,530
which is a cloud of gas and dust
540
00:46:22,613 --> 00:46:27,785
in the Large Magellanic cloud, which is
a satellite galaxy of the Milky Way.
541
00:46:27,868 --> 00:46:32,790
And this is what it looks like
on any clear, starry night of the year.
542
00:46:33,416 --> 00:46:39,171
But on one night in 1987,
the Tarantula Nebula looked like that.
543
00:46:39,588 --> 00:46:43,217
You see that a new, bright star
has appeared in the sky.
544
00:46:43,718 --> 00:46:49,098
This is a supernova explosion,
the explosive death of a massive star.
545
00:46:49,974 --> 00:46:53,644
And they are incredibly violent
cosmic events,
546
00:46:54,061 --> 00:46:56,439
as this picture beautifully shows.
547
00:46:56,522 --> 00:47:00,901
This is a galaxy about
55 million light years away from Earth,
548
00:47:01,485 --> 00:47:05,448
but this is a supernova explosion
in that galaxy.
549
00:47:05,823 --> 00:47:09,160
And you see that it is shining
as brightly as the galactic core.
550
00:47:09,243 --> 00:47:12,496
There may be a billion suns
in that core,
551
00:47:12,747 --> 00:47:17,293
and öne supernova
can shine as brightly as that.
552
00:47:20,338 --> 00:47:23,758
Yet to really appreciate
the scale of these explosions,
553
00:47:23,841 --> 00:47:26,469
we would need to see one up close,
554
00:47:26,886 --> 00:47:30,765
to see a star die in our own galaxy,
the Milky Way.
555
00:47:32,475 --> 00:47:37,396
Although on average there's öne big
supernova in each galaxy every century,
556
00:47:37,480 --> 00:47:41,942
there hasn't been öne in the Milky Way
since the birth of modern science.
557
00:47:43,110 --> 00:47:46,864
The last was in 1604,
so we're long overdue.
558
00:47:47,740 --> 00:47:50,242
Astronomers are now searching the skies
559
00:47:50,326 --> 00:47:53,913
for the star that is
most likely to go supernova.
560
00:47:54,080 --> 00:47:57,833
And amongst the leading candidates,
there's a familiar name.
561
00:47:58,626 --> 00:48:03,672
This is the constellation of Orion,
and this is Betelgeuse.
562
00:48:04,173 --> 00:48:07,676
And we know it's extremely unstable
563
00:48:07,760 --> 00:48:13,015
because it's dimmed by about 1596
in the last 10 years.
564
00:48:13,682 --> 00:48:18,813
Now, astronomers think that this star
could go supernova at any moment.
565
00:48:21,774 --> 00:48:25,111
That could mean
arnıy time in the next million years,
566
00:48:25,194 --> 00:48:27,863
but egually it could explode tomorrow.
567
00:48:29,698 --> 00:48:33,160
And Betelgeuse is only
600 light years away.
568
00:48:36,664 --> 00:48:40,459
Now, when it goes,
Betelgeuse will be incredibly bright.
569
00:48:41,794 --> 00:48:45,506
It will be by far
the brightest star in the sky.
570
00:48:45,589 --> 00:48:48,342
It may shine as brightly as a full moon.
571
00:48:48,676 --> 00:48:52,805
It will be almost a second sun
in the daylight.
572
00:49:13,993 --> 00:49:18,289
In this single instant,
Betelgeuse will release more energy
573
00:49:18,372 --> 00:49:21,500
than our sun will produce
in its entire lifetime.
574
00:49:27,339 --> 00:49:31,552
As the star is torn apart,
it will fire out into space
575
00:49:31,635 --> 00:49:36,474
all the elements
that it created in its life and death.
576
00:49:38,184 --> 00:49:41,645
Those elements will spread out
to become a nebula,
577
00:49:41,729 --> 00:49:45,232
a rich chemical cloud
drifting through space.
578
00:49:47,067 --> 00:49:51,071
And at the heart of the nebula
will be a tiny beacon of light,
579
00:49:52,490 --> 00:49:57,453
the remnant of a star, öonce more than
a billion and a half kilometres across,
580
00:49:57,953 --> 00:50:01,832
that has been crushed
out of all recognition by gravity.
581
00:50:06,170 --> 00:50:09,548
This is Betelgeuse, the neutron star.
582
00:50:14,512 --> 00:50:17,973
And it's how this önce mighty star
Will end its life.
583
00:50:32,154 --> 00:50:34,240
Now, once Betelgeuse is gone,
584
00:50:34,323 --> 00:50:37,826
the constellation of Orion
will look very different.
585
00:50:37,910 --> 00:50:41,121
I mean,
there'll just be a hole in the sky
586
00:50:41,205 --> 00:50:45,042
where that brilliant,
bright red star once shone.
587
00:50:45,751 --> 00:50:50,339
But it's in the deaths of old stars
that new stars are born.
588
00:50:50,673 --> 00:50:55,261
It's very much like the cycle
of death and rebirth here on Earth,
589
00:50:55,302 --> 00:50:57,263
but played out on a cosmic scale.
590
00:50:57,846 --> 00:51:02,017
And you can see that happening today
in the constellation of Orion,
591
00:51:02,101 --> 00:51:07,481
because in the sword handle,
you can see this, the Orion nebula.
592
00:51:07,565 --> 00:51:09,066
Now, it's nothing more than
593
00:51:09,149 --> 00:51:13,362
a misty patch of light in
the night sky to the naked eye.
594
00:51:13,445 --> 00:51:17,866
But if you look more closely, you see
that there is a lot more going on.
595
00:51:24,498 --> 00:51:28,127
The Orion nebula is öone of
the wonders of the universe.
596
00:51:33,882 --> 00:51:37,219
Hidden in its clouds
are bright points of light.
597
00:51:40,764 --> 00:51:42,558
These are new stars
598
00:51:42,641 --> 00:51:47,062
forming from the elements
blown out by supernova explosions.
599
00:51:51,942 --> 00:51:56,655
New stars being born
from the remains of dead ones.
600
00:51:58,907 --> 00:52:04,371
And it's from this universal process
of death and rebirth that we emerged,
601
00:52:06,540 --> 00:52:10,836
because it was in a nebula
just like this, five billion years ago,
602
00:52:12,421 --> 00:52:14,757
that our sun was formed.
603
00:52:24,099 --> 00:52:26,935
Around it, a network of planets formed.
604
00:52:29,146 --> 00:52:31,273
Among them was the Farth.
605
00:52:32,441 --> 00:52:37,738
Everything we find on the Farth today
also originated in that nebula.
606
00:52:41,784 --> 00:52:46,121
But that is not the end of the story
of how the universe created us.
607
00:52:50,376 --> 00:52:52,878
Because when we look
deep into the nebula,
608
00:52:52,961 --> 00:52:55,381
we don't just see individual elements,
609
00:52:55,464 --> 00:52:59,760
we see greater complexity,
the seeds of our own existence.
610
00:53:00,678 --> 00:53:05,182
This is a spectrum of
the light from the Orion nebula
611
00:53:05,265 --> 00:53:07,351
taken by the Herschel space telescope.
612
00:53:07,434 --> 00:53:11,939
So it really is a picture of light
from interstellar space.
613
00:53:12,523 --> 00:53:15,651
You know, I wouldn't normally show you
a graph like this,
614
00:53:15,734 --> 00:53:18,779
but this is fascinating,
because what it shows
615
00:53:18,821 --> 00:53:21,782
is that that gas cloud,
the Orion nebula,
616
00:53:21,865 --> 00:53:24,827
is not just a cloud of elements.
617
00:53:24,910 --> 00:53:28,664
There's complex chemistry here
happening in deep space.
618
00:53:28,747 --> 00:53:32,418
Because each peak on this graph
corresponds to a different molecule
619
00:53:32,459 --> 00:53:36,380
and there are some molecules present
that I suppose are guite obvious.
620
00:53:36,422 --> 00:53:39,508
There's water, there's sulphur dioxide.
621
00:53:39,591 --> 00:53:42,970
But there are also
complex carbon compounds in here.
622
00:53:43,053 --> 00:53:45,931
So there's methanol,
there's hydrogen cyanide,
623
00:53:46,014 --> 00:53:48,600
there's formaldehyde,
there's dimethyl ether.
624
00:53:48,684 --> 00:53:52,187
So what we're seeing here
is complex carbon chemistry
625
00:53:52,271 --> 00:53:54,231
happening in deep space.
626
00:54:00,070 --> 00:54:04,158
That carbon chemistry is the beginning
of the chemistry of life.
627
00:54:05,659 --> 00:54:08,746
And there is surprising evidence
that this chemistry
628
00:54:08,829 --> 00:54:12,833
may have had a direct impact
on the evolution of life on Farth.
629
00:54:19,798 --> 00:54:22,468
That evidence comes from meteorites,
630
00:54:25,137 --> 00:54:28,557
debris left over from
the formation of the solar system
631
00:54:28,640 --> 00:54:31,477
that occasionally collides
with the Farth.
632
00:54:41,862 --> 00:54:45,032
One of the most productive places
for finding meteorites
633
00:54:45,115 --> 00:54:48,952
is the Atacama Desert
in the High Andes of South America.
634
00:54:58,837 --> 00:55:00,005
This is a meteorite,
635
00:55:00,088 --> 00:55:05,719
a piece of rock that fell to Earth from
somewhere out there in the solar system.
636
00:55:06,261 --> 00:55:10,849
And it is certainly older
than any rock you can see here.
637
00:55:11,350 --> 00:55:15,938
It's probably older than any rock
you can find anywhere on Earth,
638
00:55:15,979 --> 00:55:19,691
because it formed from
the primordial gas cloud,
639
00:55:19,775 --> 00:55:21,819
that nebula that collapsed
640
00:55:21,860 --> 00:55:25,364
to form the sun and the planets
over four and a half billion years ago.
641
00:55:25,447 --> 00:55:27,533
So it's incredibly ancient.
642
00:55:28,450 --> 00:55:33,330
Now, this is a slice,
a cross-section through a meteorite.
643
00:55:33,997 --> 00:55:37,167
You see those little
brown areas in there?
644
00:55:37,251 --> 00:55:41,547
Well, in those brown areas
we've found amino acids,
645
00:55:41,630 --> 00:55:43,966
the building blocks of proteins,
646
00:55:44,049 --> 00:55:48,136
which are the building blocks of me,
the building blocks of life.
647
00:55:48,220 --> 00:55:50,973
Incredibly complex carbon compounds.
648
00:55:51,515 --> 00:55:56,228
So this says that
the complex carbon chemistry you need
649
00:55:56,311 --> 00:55:59,314
to send you on the path to life
650
00:55:59,398 --> 00:56:04,069
was happening out there in space
four and a half billion years ago.
651
00:56:11,869 --> 00:56:17,666
So the first amino acids on Farth,
the fundamental building blocks of life,
652
00:56:17,749 --> 00:56:20,502
may have formed in the depths of space
653
00:56:20,586 --> 00:56:23,589
and been delivered to the Farth
on meteorites.
654
00:56:32,723 --> 00:56:37,394
When we look out into space,
we are looking into our own origins,
655
00:56:42,482 --> 00:56:45,861
because we are truly
children of the stars.
656
00:56:47,279 --> 00:56:51,408
And written into every atom
and every molecule of our bodies
657
00:56:51,491 --> 00:56:57,122
is the entire history of the universe,
from the Big Bang to the present day.
658
00:57:02,294 --> 00:57:05,714
Our story is the story of the universe.
659
00:57:06,048 --> 00:57:08,008
Every piece of everyone,
660
00:57:08,675 --> 00:57:11,511
of everything you love
and everything you hate,
661
00:57:11,595 --> 00:57:17,476
of the thing you hold most precious,
was assembled by the forces of nature
662
00:57:17,559 --> 00:57:20,938
in the first few minutes
of the life of the universe,
663
00:57:20,979 --> 00:57:27,444
transformed in the hearts of stars
or created in their fiery deaths.
664
00:57:28,111 --> 00:57:29,529
And when you die,
665
00:57:29,613 --> 00:57:32,699
those pieces will be
returned to the universe
666
00:57:32,783 --> 00:57:36,244
in the endless cycle
of death and rebirth.
667
00:57:37,704 --> 00:57:41,875
What a wonderful thing it is
to be a part of that universe.
668
00:57:42,167 --> 00:57:45,921
And what a story, what a majestic story.
669
00:57:46,713 --> 00:57:49,299
(ACROSS THE UÜNİVERSE
BY DAVID BOWLIE PLAYING)
59804
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