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*

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Did you ever stop to wonder
where your car came from?

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Where it really came from?

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Every component has been
on a mind-blowing journey,

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through time, space...

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..and the most violent cosmic events
since the Big Bang.

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The history of your car
is the history of the universe.

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How old is a car?

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My car is about five years old.

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My car was assembled in 2001.

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The car I drive is pretty old.

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It was manufactured in 1991,

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but that's just when the pieces
and parts were assembled.

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The materials that make up
the cars we drive today

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were created long before 1991.

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Your car began its life
billions of years ago,

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billions of miles away
in deep space.

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The things that make up cars, those
atoms, most of them were forged

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well before our Earth was born.

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You think your car is a clunker?

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It's actually
13.8 billion years old.

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All right. Let's do it, sir.

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The best way to find out
what a car is made out of

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is to tear one apart.

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Iron, plastics, oils and rubber
are the first to be removed.

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In another half-hour or so,

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this baby's going to be
completely stripped.

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I can't wait to see it.

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Then aluminium, silicon, copper

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and finally, precious metals
like platinum and gold.

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Each of these materials
is crucial for building a car...

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..but in the earliest days
of the universe,

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none of them existed.

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13.8 billion years ago,

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the universe was born
in a monumental event...

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..the Big Bang.

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The early universe was filled
with nothing but energy.

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After the Big Bang,

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it was just a chaotic glob of stuff,
nothing like what you see today.

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As the early universe cools,

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the energy gave way
to unstable matter and antimatter.

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Then protons and neutrons,

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and finally, atoms.

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But not the iron, silicon
or carbon atoms that we use in a car,

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the universe was almost
entirely made up of hydrogen.

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Something had to happen to
give us everything else

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and everything was actually made
from hydrogen building-blocks.

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An atom of hydrogen is the simplest
and lightest atom in the universe -

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just a single positively-charged
proton bound to a single electron.

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The universe built up bigger atoms
such as carbon and iron

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by joining hydrogen atoms together.

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Everything starts
from simpler origins.

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An iron atom is actually lots
and lots of simple hydrogen atoms

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that were stuck together.

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But hydrogen atoms
don't naturally stick together.

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Protons are positively charged.

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So as you push them closer together,

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they're gonna resist
coming closer together.

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They really don't want to hang out.

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This repulsion makes
the early universe

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a maelstrom of hydrogen atoms
swerving to avoid each other.

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But if you can get them to a point

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where you can
shove them together enough,

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at some point,
they're going to lock together.

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Pushing atoms together
so strongly that they fuse

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is called nuclear fusion.

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It's the first step
in turning a universe full of gas

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into one filled with
the ingredients for planets,

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people and cars.

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Getting two atoms to fuse
is child's play...

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at least it is
if your name's Taylor Wilson.

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Taylor's been fusing atoms
in his garage since he was 14.

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Yeah, the neighbours
know about the radioactive stuff

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that's in the garage,
and so does the government.

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It's all relatively low-level.

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(BEEPING)

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It's my watch going off.

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I think I'm the only person

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I've ever met with
a Geiger-counter watch.

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The centrepiece of
Taylor's nuclear man cave

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is a precision-engineered
fusion reactor

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which he built when
he was still in high school.

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OK, I'll let in some gas now.

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The first ingredient - hydrogen gas.

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And it will be flowed
into the chamber

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through this very precise
sapphire leak valve.

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The next ingredient -
high-voltage electricity.

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Hm.

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Oh, I wonder what the problem is!

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You forgot to plug it in.
The power supply is not plugged in.

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OK, let's try that again.
That's embarrassing.

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We'll get power from
the laundry room now.

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Taylor passes a high voltage

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through a small spherical cage
that sits inside the reactor.

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The negatively-charged cage

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quickly pulls
the hydrogen ions towards it.

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So it's taking all those ions
and sucking them towards the centre.

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And as they fly in,
they get confined,

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and hopefully they collide
with each other and fuse.

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The temperature of the atoms
inside the cage is now so great

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that hydrogen atoms
are fusing together,

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creating heavier helium atoms
and a burst of energy hotter
than the surface of the sun.

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That little tiny blob of plasma
inside those grid wires,

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that's kind of
like a star in a jar.

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13 billion years ago,

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the universe used gravity
instead of an electrical cage

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to fuse atoms together.

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Across the cosmos,

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vast clouds of hydrogen gas
collapsed under their own gravity.

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Pressure and temperature built as
more and more gas was sucked in.

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Eventually, fusion sparked deep in
the core of these giant balls of gas,

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and the first stars
started to manufacture

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many of the heavy elements
that make up cars today.

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A star is basically a machine

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for turning lighter elements
into heavier elements.

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Fusion took place inside
the core of these first stars,

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fusing hydrogen atoms
together to create helium.

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And when all the hydrogen
in the core had been used up,

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the star finds new fuel to burn.

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After you burn hydrogen
to form helium,

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the core of the star begins
to collapse and get hotter.

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And there is enough energy then

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to fuse three helium
nuclei into carbon...

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..and then that fuses to form
nitrogen, oxygen, silicon, iron.

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But this incredible production line
of elements can't go on forever.

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The heavier atoms you ram together,
the less energy you get out.

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So you turn hydrogen into helium,

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helium becomes carbon,
nitrogen, oxygen.

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But every time, there's
a bit less energy to be had,

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until you get to iron.

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The iron that is in your car

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is actually, essentially, a deadly
poison when it comes to a star.

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It's robbing that star of the heat
needed to keep itself up.

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So the star collapses,
dies and explodes

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at the moment you
create iron in the core.

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I mean, literally,
the fraction of a second.

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I'm not kidding. That's how dramatic
and weird the steel in your car is.

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The explosion, called a supernova,

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is one of the brightest and most
violent events in the universe.

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It releases enough energy

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to dwarf what the sun puts out
over its entire lifetime.

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And all of the elements
that it has created

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are then dispersed out into space.

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The gassy remains of the explosion
are called a supernova remnant,

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an expanding bubble of gas
containing hydrogen that survived
in the star's outer layers,

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mixed in with carbon, oxygen, silicon
and iron from the star's core.

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This 13 billion-year-old stardust
helped you drive to work last week.

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This was once in the core
of a dying star.

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And who knows? Maybe some
of the iron atoms in this brake disc

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were forged in the heart of
the very first generation of stars

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that illuminated the universe.

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When you're pumping iron,
you're pumping the universe.

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The first stars created
the materials in a car's chassis,

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body, windshield and seats.

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But key components, like the copper
for the car's electronics,

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are yet to be manufactured.

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To create this crucial metal,

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a new generation of stars
must die an even stranger death.

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*

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*

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Picture the scene
13 billion years ago...

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..as the universe's very first stars
are coming to the end of their lives.

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The sky is filled with flashes

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as star after star
violently explodes.

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These supernovas hurl a rich
cocktail of elements into space...

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..carbon, silicon,
aluminium and iron,

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materials that will one day
be used to build cars on Earth.

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But some even heavier elements

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needed to build a car
are still missing.

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Elements like copper and gold,
used in the car's wiring.

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So far, the universe hasn't
created these heavy metals,

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but it's about to.

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In the case of copper,

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the secret to its formation
is reincarnation.

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Copper is one metal that
your car can't live without.

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It turns out, there's over a mile
of copper in the average car.

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And the reason why

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is because copper is
an excellent electrical conductor.

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Copper's also used
to conduct heat in radiators.

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It stops bearings from failing
when you need to go fast.

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And when you need to stop...

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..copper provides the friction
in your brake pads.

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But the story of how that copper
came to exist and be on Earth,

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that's a truly remarkable story.

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Copper can't begin to form

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until the first generation
of stars have died.

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The expanding supernova remnants

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crash into neighbouring
clouds of gas...

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..creating a shock wave of pressure,

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a perfect nursery for
a new generation of stars.

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There are cycles to the universe.

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Stars form,
they live out their lives.

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They die, they blow
off winds and they explode,

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seeding their material into gas
clouds which then form new stars

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with heavier elements in them,
which will repeat the cycle again.

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So if you wanna think
about it that way,

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the universe
is the ultimate recycler.

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The gas that forms
these second-generation stars

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is peppered with the carbon,
aluminium and iron

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thrown out by the supernova.

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The biggest of these new stars
burn extremely brightly,

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but only for a few million years...

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..then they undergo
an incredible metamorphosis.

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The star rapidly expands
to 100 times its previous size...

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..then it cools
and turns a ghostly red.

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A second-generation star
has transformed

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into a red supergiant.

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And in its diffuse outer layers,

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iron is slowly converted
into copper...

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..but not by fusion.

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That iron nucleus has 26 protons.

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That's a serious electric charge,

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so it's going to repel any protons
we try to shoot in there.

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How do we get more protons in?

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The way we get those protons
in there is we trick the nucleus.

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Instead of shooting in protons,
we shoot in neutrons.

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Colliding atoms
in the outer layers of a star

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sometimes spit out neutrons.

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Neutrons don't have a charge,
so they're not repelled

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by the positively-charged protons
in the iron stardust.

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These neutrons are able to stick
to the iron atoms around them.

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An atom is a very tiny thing
and makes a very small target.

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But there's a lot of particles
flying around near a star,

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and if, by chance, a neutron
can hit an atom, it can stick,

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and that will actually make
the nucleus of the atom larger.

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Neutron by neutron can hit an atom

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and then that neutron can
actually decay into a proton.

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The neutron spontaneously splits
into an electron, which is ejected,

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and a proton, which is left behind.

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The process transforms iron
into copper.

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Scientists call this
magical conversion "beta decay".

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So you can build up
heavy elements very slowly

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over the course of
thousands or millions of years,

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just by capturing neutrons.

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Eventually, the core of
the red supergiant runs out of fuel

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and the star explodes...

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..blasting its copper-rich
outer layer into space.

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Thanks to the life and death
of two generations of stars...

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..we can equip our car
with copper wiring.

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But we're still short
of some even heavier metals,

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such as lead for the battery,

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and gold for
the electrical connectors.

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To make these truly massive atoms...

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..the universe must create
the most spectacular explosions

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since the Big Bang.

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To make a car, you need
some seriously heavy metal.

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Metal like iridium,

248
00:16:50,000 --> 00:16:53,320
a supersized atom with 77 protons

249
00:16:53,400 --> 00:16:55,960
that's used to coat
the tips of spark plugs.

250
00:16:59,080 --> 00:17:03,320
Heavier still is gold,
with 79 protons.

251
00:17:04,400 --> 00:17:07,040
This shiny conductor
resists corrosion,

252
00:17:07,120 --> 00:17:10,240
making it ideal
for exposed electrical connections.

253
00:17:12,440 --> 00:17:16,400
These connectors here
for this airbag assembly are gold,

254
00:17:16,480 --> 00:17:18,560
and so this thing
can react really quickly

255
00:17:18,640 --> 00:17:20,680
if there's an accident
and save your life.

256
00:17:24,760 --> 00:17:28,080
The heaviest atom
found in a car is lead,

257
00:17:28,160 --> 00:17:30,000
with 82 protons.

258
00:17:32,000 --> 00:17:34,800
Only lead can deliver
the short burst of high power

259
00:17:34,880 --> 00:17:38,200
needed to start an engine
over and over again.

260
00:17:46,360 --> 00:17:48,360
But until very recently,

261
00:17:48,440 --> 00:17:51,880
how the universe
made these oversized atoms

262
00:17:51,960 --> 00:17:53,360
was a complete mystery.

263
00:17:54,720 --> 00:17:57,320
You can't make gold atoms
in a normal star.

264
00:17:58,800 --> 00:18:02,040
You can't make gold atoms
in a massive star that's dying.

265
00:18:03,880 --> 00:18:07,080
In order to make atoms this big,
with this many neutrons,

266
00:18:07,160 --> 00:18:09,320
you need a truly cataclysmic event.

267
00:18:13,160 --> 00:18:14,440
Just a few years ago,

268
00:18:14,520 --> 00:18:16,800
most scientists
believed that supernovas

269
00:18:16,880 --> 00:18:19,440
were cataclysmic enough
to do the job.

270
00:18:23,400 --> 00:18:26,160
But astronomer Edo Berger
had doubts.

271
00:18:27,640 --> 00:18:30,800
If you open any one of these books
and flip to the page

272
00:18:30,880 --> 00:18:32,640
that tells you where gold came from,

273
00:18:32,720 --> 00:18:35,480
it will tell you that gold
came from supernova explosions.

274
00:18:36,600 --> 00:18:38,880
But nobody had directly
observed supernovas

275
00:18:38,960 --> 00:18:41,640
producing elements like gold.

276
00:18:41,720 --> 00:18:44,200
And inside computer simulations,

277
00:18:44,280 --> 00:18:48,240
virtual supernovas lacked the energy
to forge these oversized atoms.

278
00:18:49,320 --> 00:18:51,600
Clearly, something was wrong.

279
00:18:51,680 --> 00:18:54,640
But if supernovas
weren't powerful enough,

280
00:18:54,720 --> 00:18:56,880
what in the universe was?

281
00:18:56,960 --> 00:18:59,400
To form heavy elements
requires a lot of neutrons,

282
00:18:59,480 --> 00:19:03,400
and so another possible theory
was that the heaviest elements

283
00:19:03,480 --> 00:19:06,880
were produced in the mergers of two
neutron stars in a binary system.

284
00:19:11,320 --> 00:19:14,600
Neutron stars are some of the
strangest objects in the universe.

285
00:19:15,680 --> 00:19:19,160
They're formed from
the collapsed cores of giant stars.

286
00:19:20,560 --> 00:19:23,280
You're taking a couple
of times the mass of the sun

287
00:19:23,360 --> 00:19:27,200
and squeezing it down into a ball
that's only a few miles across.

288
00:19:27,280 --> 00:19:30,560
The electrons and the protons that
are flitting around inside of that

289
00:19:30,640 --> 00:19:32,480
combine to form neutrons.

290
00:19:32,560 --> 00:19:37,960
And what you're left with is an
extremely dense ball of neutrons

291
00:19:38,040 --> 00:19:39,960
about the size of a city.

292
00:19:42,360 --> 00:19:44,960
Neutron stars are extremely dense.

293
00:19:45,040 --> 00:19:48,480
If you take just a teaspoon
of the neutron star material,

294
00:19:48,560 --> 00:19:50,600
it's actually a billion tonnes.

295
00:19:51,720 --> 00:19:54,240
If neighbouring stars die together,

296
00:19:54,320 --> 00:19:57,200
it's possible for the two
neutron stars they leave behind

297
00:19:57,280 --> 00:19:59,560
to form a spinning binary pair.

298
00:20:00,880 --> 00:20:03,560
But the partnership is doomed.

299
00:20:03,640 --> 00:20:06,600
What you're left over with
is two incredibly compact,

300
00:20:06,680 --> 00:20:09,040
dramatic objects
spiralling around each other.

301
00:20:12,320 --> 00:20:17,480
Over time, they move in together,
until finally, they can coalesce

302
00:20:17,560 --> 00:20:20,280
in the most violent explosion
since the Big Bang.

303
00:20:25,320 --> 00:20:28,920
The explosion is called
a neutron-star merger.

304
00:20:30,360 --> 00:20:33,840
The amount of energy
in this explosion is crushing.

305
00:20:33,920 --> 00:20:36,000
There's almost no way
to describe it.

306
00:20:36,080 --> 00:20:38,120
It's like taking
all of the sun's energy

307
00:20:38,200 --> 00:20:40,760
that it will ever emit
over its entire lifetime

308
00:20:40,840 --> 00:20:43,000
and releasing it in a single second.

309
00:20:48,440 --> 00:20:51,160
Berger suspected
that this colossal explosion

310
00:20:51,240 --> 00:20:53,560
forged iridium, gold and lead...

311
00:20:54,640 --> 00:20:58,160
..but to rewrite the textbooks,
he needed hard evidence.

312
00:20:59,240 --> 00:21:01,800
It was difficult
to convince the community

313
00:21:01,880 --> 00:21:04,040
that this was a potential channel

314
00:21:04,120 --> 00:21:05,960
for the production
of heavy elements.

315
00:21:10,160 --> 00:21:13,720
The proof is to actually see this
process happening in the universe.

316
00:21:17,080 --> 00:21:18,440
June 2013.

317
00:21:19,720 --> 00:21:23,520
NASA's Swift satellite
spotted a short burst of gamma rays

318
00:21:23,600 --> 00:21:24,960
from a nearby galaxy...

319
00:21:26,360 --> 00:21:30,640
..a sign that a neutron-star merger
had just taken place.

320
00:21:30,720 --> 00:21:33,680
For Berger, it was the lucky break
he'd been waiting for.

321
00:21:36,720 --> 00:21:40,000
As soon as we knew that there
was a gamma-ray burst nearby,

322
00:21:40,080 --> 00:21:44,480
we knew that this was our one
chance, for perhaps several years,

323
00:21:44,560 --> 00:21:49,440
to obtain the right kind
of measurements to test
the formation of heavy elements.

324
00:21:51,320 --> 00:21:53,840
Once Swift had identified the burst,

325
00:21:53,920 --> 00:21:57,760
the Hubble Space Telescope
swung into action to capture images.

326
00:22:01,680 --> 00:22:04,080
We grabbed them right away
and we just looked.

327
00:22:04,160 --> 00:22:07,200
We knew exactly where to look,
at the centre of this red circle.

328
00:22:07,280 --> 00:22:10,320
And what we saw was this source
right there in the middle

329
00:22:10,400 --> 00:22:13,560
that is the direct signature

330
00:22:13,640 --> 00:22:16,440
of the production of very
heavy elements, including gold.

331
00:22:20,360 --> 00:22:22,520
Berger's theory was right,

332
00:22:22,600 --> 00:22:25,840
but the rate of production
was far higher than he'd expected.

333
00:22:27,440 --> 00:22:28,800
Well, in that one event,

334
00:22:28,880 --> 00:22:32,280
the amount of gold that was produced
was more than the mass of the Earth.

335
00:22:34,000 --> 00:22:35,360
If we can bring it all here,

336
00:22:35,440 --> 00:22:38,600
it would be worth quadrillions
and quadrillions of dollars.

337
00:22:40,720 --> 00:22:43,360
The theory is still very new,

338
00:22:43,440 --> 00:22:46,760
but it's possible that
ancient neutron-star mergers

339
00:22:46,840 --> 00:22:49,560
made all the heavy metals
we see in the world today...

340
00:22:51,720 --> 00:22:55,800
..including the last remaining
ingredients for our car.

341
00:23:03,080 --> 00:23:06,080
But all these elements
were floating free in space.

342
00:23:07,680 --> 00:23:12,240
They still have to be pulled together
into one giant fabrication plant...

343
00:23:16,760 --> 00:23:18,000
..the Earth.

344
00:23:21,440 --> 00:23:23,440
*

345
00:23:25,000 --> 00:23:27,000
*

346
00:23:34,480 --> 00:23:36,240
Before the Earth was born,

347
00:23:36,320 --> 00:23:39,960
all the materials that would
one day go into making your car

348
00:23:40,040 --> 00:23:41,560
looked like this.

349
00:23:41,640 --> 00:23:45,840
A vast, swirling cloud
of gas and stardust,

350
00:23:45,920 --> 00:23:48,640
the exploded remnants
of ancient stars.

351
00:23:48,720 --> 00:23:50,880
The clouds between
the stars of the galaxy

352
00:23:50,960 --> 00:23:53,400
are made of everything that
the Earth, your body

353
00:23:53,480 --> 00:23:54,640
and your car is made of.

354
00:23:54,720 --> 00:23:56,880
There's everything
that you need floating

355
00:23:56,960 --> 00:23:59,200
in gaseous form between the stars.

356
00:24:00,560 --> 00:24:02,520
Four-and-a-half billion years ago,

357
00:24:02,600 --> 00:24:05,240
this interstellar gas
collapsed once more.

358
00:24:06,520 --> 00:24:10,000
This time to create a rather
ordinary mid-sized star...

359
00:24:11,960 --> 00:24:13,040
..our sun.

360
00:24:13,840 --> 00:24:17,560
Close to the young sun, all of
the lighter stuff got blown away.

361
00:24:17,640 --> 00:24:20,640
What was left behind
was the heavier, denser stuff.

362
00:24:23,360 --> 00:24:26,200
There was carbon,
there was iron, there was gold,

363
00:24:26,280 --> 00:24:27,800
everything in-between.

364
00:24:29,880 --> 00:24:34,520
Over time, these free-floating
elements began to coalesce.

365
00:24:34,600 --> 00:24:37,840
Dust became rock.

366
00:24:39,320 --> 00:24:43,280
Rocks joined to form
larger objects called planetesimals.

367
00:24:44,880 --> 00:24:48,680
Finally, planetesimals
joined to form the Earth.

368
00:24:52,520 --> 00:24:56,440
Our planet was born with all the
ingredients needed to build a car...

369
00:24:57,600 --> 00:25:01,240
..but these ingredients were
about to go their separate ways.

370
00:25:03,400 --> 00:25:04,680
The Earth is a big planet

371
00:25:04,760 --> 00:25:07,080
and it's done something
that not all planets do,

372
00:25:07,160 --> 00:25:08,920
it's differentiated, it melted.

373
00:25:11,480 --> 00:25:13,720
Copper and lead dissolved in sulphur

374
00:25:13,800 --> 00:25:16,760
and floated to the top
of the molten Earth,

375
00:25:16,840 --> 00:25:19,760
making these metals
easy to mine today.

376
00:25:22,480 --> 00:25:25,320
But precious metals
like iridium and gold

377
00:25:25,400 --> 00:25:29,840
sunk to the Earth's core
and most of the iron sunk with them.

378
00:25:30,920 --> 00:25:32,440
It's kind of a pain, actually.

379
00:25:32,520 --> 00:25:35,160
All the heavy elements
that are super-useful, like iron,

380
00:25:35,240 --> 00:25:38,080
they've sunk to the middle of the
Earth where we can't reach them

381
00:25:38,160 --> 00:25:40,560
and there's not a whole
lot of it in the crust.

382
00:25:44,600 --> 00:25:47,960
3.8 billion years ago,
the oceans formed

383
00:25:48,040 --> 00:25:50,840
and water dissolved
the last remaining traces of iron

384
00:25:50,920 --> 00:25:52,400
from the Earth's surface.

385
00:25:55,440 --> 00:25:57,440
In fact, there was
so much iron in the sea

386
00:25:57,520 --> 00:26:01,120
that the Earth would've been green,
not blue like it is today.

387
00:26:02,800 --> 00:26:06,200
The Earth's crust seemed
destined to be practically iron-free.

388
00:26:07,560 --> 00:26:10,120
Then along came
the most unlikely saviour...

389
00:26:11,880 --> 00:26:13,360
..green slime.

390
00:26:15,800 --> 00:26:18,400
I want to show you
a couple of examples of rocks

391
00:26:18,480 --> 00:26:20,800
that we recently
brought back from South Africa.

392
00:26:22,000 --> 00:26:24,240
Caltech geobiologist Woody Fischer

393
00:26:24,320 --> 00:26:27,320
traced the history of iron through
the Earth's earliest rocks.

394
00:26:29,240 --> 00:26:32,240
This is an example of a rock
that was deposited on the seafloor

395
00:26:32,320 --> 00:26:34,560
a little over
two-and-a-half billion years ago,

396
00:26:34,640 --> 00:26:36,840
and there's not a lot
of iron in this sample.

397
00:26:36,920 --> 00:26:41,040
Now, what's so interesting is you
go to the same place on the Earth

398
00:26:41,120 --> 00:26:43,000
200 million years later,

399
00:26:43,080 --> 00:26:45,920
and what you find is that
things have really changed.

400
00:26:46,000 --> 00:26:49,040
And you'll note this
very rusty colour to it.

401
00:26:49,120 --> 00:26:51,080
This is from the presence
of iron oxides,

402
00:26:51,160 --> 00:26:55,320
and in fact, the rock itself
is incredibly heavy, very dense.

403
00:26:57,400 --> 00:27:02,200
Why did the Earth's geological record
change so quickly and so profoundly?

404
00:27:03,720 --> 00:27:07,360
One clue is that the sudden
appearance of iron-rich rocks

405
00:27:07,440 --> 00:27:10,720
coincides with the rise
of the first simple plants.

406
00:27:13,720 --> 00:27:17,480
This is a microorganism
called a cyanobacterium.

407
00:27:17,560 --> 00:27:20,480
Each of the individual cells
that are present in that medium

408
00:27:20,560 --> 00:27:23,360
are green and they're
conducting photosynthesis.

409
00:27:23,440 --> 00:27:28,160
This group of cyanobacteria
is gathering energy from light,

410
00:27:28,240 --> 00:27:32,280
using that to split water,
and in so doing,

411
00:27:32,360 --> 00:27:34,280
they produce
copious amounts of oxygen.

412
00:27:37,240 --> 00:27:38,760
In the early oceans,

413
00:27:38,840 --> 00:27:43,040
this newly formed oxygen
reacted with the dissolved iron,

414
00:27:43,120 --> 00:27:46,560
forming a heavy rust
that settled on the ocean-floor.

415
00:27:48,360 --> 00:27:51,000
For the first time in
Earth's history, there was oxygen,

416
00:27:51,080 --> 00:27:52,720
free oxygen, in the air.

417
00:27:52,800 --> 00:27:54,760
That combined with the iron

418
00:27:54,840 --> 00:27:57,600
and the iron, basically,
sank to the bottom of the ocean.

419
00:27:59,560 --> 00:28:04,360
These ancient rusty deposits
form the iron ore that we mine today.

420
00:28:09,040 --> 00:28:12,840
So in the process of making a car,
mining the iron ore,

421
00:28:12,920 --> 00:28:15,320
life was an essential part
of that first step.

422
00:28:17,080 --> 00:28:20,320
You have to wait
until after these guys evolve

423
00:28:20,400 --> 00:28:23,840
in order to be able to concentrate
the raw materials that you need.

424
00:28:33,520 --> 00:28:36,800
The life of early plants
brought us iron,

425
00:28:36,880 --> 00:28:40,080
but their death
was perhaps even more helpful,

426
00:28:40,160 --> 00:28:44,240
because without dead plants,
most cars wouldn't run.

427
00:28:46,920 --> 00:28:49,960
So what's the final ingredient
for getting a car to actually go?

428
00:28:51,160 --> 00:28:52,560
You need to add fuel,

429
00:28:52,640 --> 00:28:55,640
and we, right now,
use hydrocarbon-based fuel.

430
00:28:55,720 --> 00:28:56,960
We use oil.

431
00:28:58,880 --> 00:29:02,120
Oil is actually
the remnant of dead plant life

432
00:29:02,200 --> 00:29:03,680
from billions of years ago.

433
00:29:04,880 --> 00:29:07,800
It amazes me to think that as
you're driving your car around,

434
00:29:07,880 --> 00:29:09,960
what you're actually
running the car on

435
00:29:10,040 --> 00:29:11,840
is ancient dead life.

436
00:29:13,440 --> 00:29:15,720
These hydrocarbons are also processed

437
00:29:15,800 --> 00:29:19,920
to help make rubber and plastics
for the tyres and interior trim.

438
00:29:27,760 --> 00:29:31,160
Now we have almost all the
components needed to complete a car.

439
00:29:32,360 --> 00:29:36,640
All that remains is a spark
to bring the engine to life...

440
00:29:38,640 --> 00:29:40,880
..but to get that spark,

441
00:29:40,960 --> 00:29:43,480
the Earth must pay
a catastrophic price.

442
00:29:46,800 --> 00:29:50,600
65 million years ago,
the Earth's crust is missing

443
00:29:50,680 --> 00:29:53,800
one crucial group
of super-tough metals.

444
00:29:58,840 --> 00:30:00,760
This is a spark plug.

445
00:30:00,840 --> 00:30:04,320
And the way it works is that
100,000 volts are put

446
00:30:04,400 --> 00:30:05,600
across this gap here...

447
00:30:06,880 --> 00:30:10,760
..and that ignites gasoline vapour
in the cylinder of your motor.

448
00:30:12,160 --> 00:30:15,200
This tip has to survive
in very harsh conditions...

449
00:30:17,000 --> 00:30:21,520
..so it must be made of a very,
very sturdy, robust material,

450
00:30:21,600 --> 00:30:25,800
and the material in this spark plug
is a metal known as iridium.

451
00:30:29,000 --> 00:30:30,520
Like gold and lead,

452
00:30:30,600 --> 00:30:35,080
iridium was created inside
the biggest bang since the Big Bang -

453
00:30:35,160 --> 00:30:37,120
a neutron star merger.

454
00:30:39,680 --> 00:30:43,240
Although the Earth originally
contained a large amount of iridium,

455
00:30:43,320 --> 00:30:47,280
it sank out of reach while
the Earth was still molten,

456
00:30:47,360 --> 00:30:50,520
falling to the core
under the influence of gravity.

457
00:30:53,320 --> 00:30:56,640
The iridium that we mine
on the Earth's surface today

458
00:30:56,720 --> 00:30:58,200
came from somewhere else.

459
00:31:00,200 --> 00:31:04,560
This exposed rock face in Colorado
reveals a clue -

460
00:31:04,640 --> 00:31:07,560
a mysterious layer
in the Earth's geological record

461
00:31:07,640 --> 00:31:10,000
that wraps around the entire planet.

462
00:31:10,080 --> 00:31:12,240
There's something
particularly interesting

463
00:31:12,320 --> 00:31:13,760
about this clay layer here.

464
00:31:13,840 --> 00:31:18,160
If you analyse
the concentration of rare metals
like iridium in this layer,

465
00:31:18,240 --> 00:31:21,320
you'll find that there's about
100 times as much iridium here

466
00:31:21,400 --> 00:31:24,160
as in the other rocks around us
in the crust of the Earth.

467
00:31:24,240 --> 00:31:25,680
It's rather bizarre, actually,

468
00:31:25,760 --> 00:31:28,360
to find so much iridium
concentrated in one place

469
00:31:28,440 --> 00:31:29,960
here in crustal rocks.

470
00:31:30,040 --> 00:31:31,880
And it turns out
that the entire budget

471
00:31:31,960 --> 00:31:33,640
of the iridium in the Earth's crust

472
00:31:33,720 --> 00:31:35,560
is pretty much
contained in this layer.

473
00:31:38,040 --> 00:31:41,960
When geologists discovered
the iridium layer in the late '70s,

474
00:31:42,040 --> 00:31:44,440
it became one of
the biggest mysteries in science.

475
00:31:46,040 --> 00:31:49,560
How could so much of this
rare metal end up concentrated

476
00:31:49,640 --> 00:31:51,280
in such a thin layer?

477
00:31:56,320 --> 00:31:59,920
Astronomers had measured similar
concentrations of iridium before...

478
00:32:01,440 --> 00:32:04,640
..inside rocks that had come
from the asteroid belt.

479
00:32:05,800 --> 00:32:09,400
Billions of years ago, planets were
forming all over our solar system,

480
00:32:09,480 --> 00:32:11,840
but there was an area
in-between Mars and Jupiter

481
00:32:11,920 --> 00:32:15,920
where the gravity of Jupiter
pretty much pulled apart
anything that tried to form.

482
00:32:16,000 --> 00:32:19,200
And what got left over
were a bunch of large, rocky chunks

483
00:32:19,280 --> 00:32:21,520
that we call the asteroid belt.

484
00:32:21,600 --> 00:32:24,160
Now, some of the asteroid belt
is made of rock.

485
00:32:25,480 --> 00:32:27,600
Other asteroids are
richer in metals.

486
00:32:30,920 --> 00:32:32,360
From time to time,

487
00:32:32,440 --> 00:32:35,640
asteroids are thrown out of orbit
by another asteroid,

488
00:32:35,720 --> 00:32:38,280
or by the long reach
of Jupiter's gravity.

489
00:32:40,120 --> 00:32:43,320
Sometimes these asteroids
smash into the Earth.

490
00:32:46,800 --> 00:32:48,080
Could the iridium layer

491
00:32:48,160 --> 00:32:52,880
be the scattered remains of a single
giant, metal-rich asteroid impact?

492
00:32:59,280 --> 00:33:02,320
30 years ago,
this idea sounded far-fetched.

493
00:33:03,440 --> 00:33:06,840
Only an asteroid the size of a city
would've had enough power

494
00:33:06,920 --> 00:33:09,560
to blast debris around
the entire planet.

495
00:33:11,000 --> 00:33:12,720
If you could imagine the magnitude,

496
00:33:12,800 --> 00:33:15,360
the enormity of the violence
of an event like that.

497
00:33:15,440 --> 00:33:18,400
And to have inches of dusty debris

498
00:33:18,480 --> 00:33:21,320
come booming over the horizon
and settling out of the sky

499
00:33:21,400 --> 00:33:24,560
and raining on top of you
and burying you in this layer,

500
00:33:24,640 --> 00:33:27,600
that should make a pretty big
crater someplace on the Earth.

501
00:33:29,680 --> 00:33:32,040
Although it sounded incredible,

502
00:33:32,120 --> 00:33:35,680
the asteroid hypothesis also
solved a long-standing mystery.

503
00:33:37,680 --> 00:33:40,200
The dinosaurs were wiped out
around the same time

504
00:33:40,280 --> 00:33:42,080
the iridium layer was laid down.

505
00:33:43,400 --> 00:33:45,720
Could the two events be linked?

506
00:33:47,000 --> 00:33:49,800
The puzzle was solved
when an asteroid-impact crater

507
00:33:49,880 --> 00:33:52,240
was discovered down in the Yucatan.

508
00:33:52,320 --> 00:33:55,720
The crater age turned out to be
exactly 65 million years old,

509
00:33:55,800 --> 00:33:57,840
the same age as this deposit.

510
00:33:57,920 --> 00:34:00,160
And the crater size turned out

511
00:34:00,240 --> 00:34:02,960
to be just the size
of crater you would get

512
00:34:03,040 --> 00:34:06,040
from the size of an asteroid
it would take to make this layer.

513
00:34:07,640 --> 00:34:09,360
So it turns out that
in a lot of ways

514
00:34:09,440 --> 00:34:12,840
you can think of asteroids as sort
of a cosmic iridium-delivery system

515
00:34:12,920 --> 00:34:14,840
for us here on
the surface of the Earth.

516
00:34:14,920 --> 00:34:18,240
And it's not just iridium
we have to thank asteroids for.

517
00:34:18,320 --> 00:34:19,960
There were probably several times

518
00:34:20,040 --> 00:34:23,320
in the history of our solar system
where there was heavy bombardment,

519
00:34:23,400 --> 00:34:26,640
all kinds of asteroids and comets
falling in toward the Earth.

520
00:34:26,720 --> 00:34:29,600
Well, the Earth had solidified
to some degree by that time,

521
00:34:29,680 --> 00:34:31,960
so not everything
sank down into the core.

522
00:34:32,040 --> 00:34:34,040
So some of the metals
we find around us

523
00:34:34,120 --> 00:34:36,600
are products of
this later era of bombardment.

524
00:34:40,400 --> 00:34:42,640
The Earth's history
is a violent one.

525
00:34:42,720 --> 00:34:46,240
Over the course of time, we've been
hit over and over and over again

526
00:34:46,320 --> 00:34:48,160
by asteroids of all sizes.

527
00:34:48,240 --> 00:34:50,440
Some of them have actually delivered

528
00:34:50,520 --> 00:34:53,440
quite a bit of heavy elements
to the surface of the Earth.

529
00:34:56,120 --> 00:34:58,200
These asteroid-borne materials

530
00:34:58,280 --> 00:35:00,600
include most of
the gold, platinum and nickel

531
00:35:00,680 --> 00:35:02,520
we use in cars today.

532
00:35:05,200 --> 00:35:09,280
Asteroid impacts will form
little pockets of concentrations

533
00:35:09,360 --> 00:35:12,320
of some of those ore minerals
and ore metals for us

534
00:35:12,400 --> 00:35:15,840
that we can then mine
in greater abundance on the surface.

535
00:35:15,920 --> 00:35:19,360
In many cases, when you go to a mine
to dig up these heavy elements,

536
00:35:19,440 --> 00:35:23,080
what you are doing is tapping
into an asteroid impact.

537
00:35:27,480 --> 00:35:30,480
But these mines are relatively rare.

538
00:35:30,560 --> 00:35:33,000
As humanity continues to grow,

539
00:35:33,080 --> 00:35:35,920
our precious metals will be
the first metals to run out.

540
00:35:37,520 --> 00:35:39,240
If we want to get more,

541
00:35:39,320 --> 00:35:42,520
the only option will be
to mine the asteroid belt itself.

542
00:35:44,360 --> 00:35:46,360
I don't think we can
keep making cars here

543
00:35:46,440 --> 00:35:48,160
on the surface of the Earth forever.

544
00:35:48,240 --> 00:35:52,040
And as population grows and our
need for these minerals grows,

545
00:35:52,120 --> 00:35:54,120
at some point,
you know, we're gonna...

546
00:35:54,200 --> 00:35:56,920
you're gonna mine the Earth
as much as it can be mined

547
00:35:57,000 --> 00:35:59,560
and you have to start
to look someplace else.

548
00:35:59,640 --> 00:36:00,800
And fortunately,

549
00:36:00,880 --> 00:36:03,440
there are mines in the sky
out there by the billions,

550
00:36:03,520 --> 00:36:04,920
and they're called asteroids.

551
00:36:06,000 --> 00:36:10,400
A lot of asteroids have platinum,
iron, nickel, gold in them.

552
00:36:10,480 --> 00:36:13,840
It's very expensive to go up there
and grab them and tow them back,

553
00:36:13,920 --> 00:36:16,400
but just the raw materials
in an asteroid

554
00:36:16,480 --> 00:36:18,720
could be worth hundreds
of billions of dollars.

555
00:36:20,600 --> 00:36:23,040
NASA recently estimated the value

556
00:36:23,120 --> 00:36:25,920
of the precious metals
and materials on the asteroid belt

557
00:36:26,000 --> 00:36:29,000
as being about $600 quintillion,

558
00:36:29,080 --> 00:36:32,880
or about $100 billion for every
person alive on the Earth today.

559
00:36:32,960 --> 00:36:35,600
But I do not expect to be
seeing any of that money myself.

560
00:36:36,720 --> 00:36:39,520
We'll have to wait for
rocket technology to get cheaper

561
00:36:39,600 --> 00:36:42,480
before asteroid-mining
becomes a viable proposition.

562
00:36:43,800 --> 00:36:47,000
Until then, we'll continue
to rely on the asteroids

563
00:36:47,080 --> 00:36:48,640
that have hit the Earth.

564
00:36:52,040 --> 00:36:55,040
Metal-rich asteroids
are the final piece of the puzzle.

565
00:36:56,840 --> 00:37:00,320
We can now reconstruct the journey
of every atom of our car

566
00:37:00,400 --> 00:37:03,200
through time and space.

567
00:37:03,280 --> 00:37:08,440
From the moment of the Big Bang,
through generations of stars

568
00:37:08,520 --> 00:37:12,160
to the birth of the Earth,
and eventually,

569
00:37:12,240 --> 00:37:14,240
the showroom floor.

570
00:37:14,320 --> 00:37:17,680
Over the course of the multiple
supernovae in our universe

571
00:37:17,760 --> 00:37:20,400
and the birth and death of stars,

572
00:37:20,480 --> 00:37:23,640
we were able to collect
all of the materials needed

573
00:37:23,720 --> 00:37:25,320
to assemble these cars.

574
00:37:26,520 --> 00:37:27,880
That's pretty fantastic.

575
00:37:31,280 --> 00:37:34,040
I think we don't fully
appreciate how complicated

576
00:37:34,120 --> 00:37:36,200
the elements that make up
our car really are

577
00:37:36,280 --> 00:37:37,480
and how special they are.

578
00:37:37,560 --> 00:37:39,560
They really are star stuff.

579
00:37:49,400 --> 00:37:52,520
But not every car is like
the one we've just pulled apart.

580
00:37:54,680 --> 00:37:57,880
These days,
not every car runs on petrol.

581
00:37:59,680 --> 00:38:02,640
Electric vehicles
require a magical element

582
00:38:02,720 --> 00:38:04,120
that's made in space...

583
00:38:05,200 --> 00:38:06,880
..by cosmic ray guns.

584
00:38:09,200 --> 00:38:11,200
*

585
00:38:13,000 --> 00:38:15,000
*

586
00:38:19,520 --> 00:38:21,320
This car doesn't have a petrol tank.

587
00:38:22,640 --> 00:38:25,760
It's part of a new generation
of electric vehicles.

588
00:38:27,640 --> 00:38:31,560
The key to these high-tech cars
is their rechargeable batteries...

589
00:38:35,280 --> 00:38:39,080
..a technology that relies on
one of the Earth's rarest metals.

590
00:38:41,560 --> 00:38:44,680
This here is a battery pack
from an electric car,

591
00:38:44,760 --> 00:38:48,640
and in today's electric cars,
the metal of choice is lithium,

592
00:38:48,720 --> 00:38:52,960
and lithium has one of the most
amazing stories in the universe.

593
00:38:55,880 --> 00:39:00,280
After hydrogen and helium,
lithium is the lightest element,

594
00:39:00,360 --> 00:39:02,800
with just three protons
and four neutrons.

595
00:39:04,000 --> 00:39:07,200
Its lightness makes it
ideal for electric cars.

596
00:39:08,760 --> 00:39:10,960
If the battery weighs
more than the car,

597
00:39:11,040 --> 00:39:14,160
then we are just wasting energy
on moving the battery around.

598
00:39:14,240 --> 00:39:18,040
If we can build a light battery,
for example, a lithium-ion battery,

599
00:39:18,120 --> 00:39:21,600
then we can provide
the power without the penalty

600
00:39:21,680 --> 00:39:24,680
of having to carry those
heavy batteries along with the car.

601
00:39:27,040 --> 00:39:28,400
Lithium is rapidly becoming

602
00:39:28,480 --> 00:39:31,520
one of the most
sought-after metals on Earth,

603
00:39:31,600 --> 00:39:33,840
but it's also a cosmic curiosity.

604
00:39:36,600 --> 00:39:39,360
The Big Bang creates
a trace of lithium,

605
00:39:39,440 --> 00:39:42,120
but as the first stars form,

606
00:39:42,200 --> 00:39:44,960
this lithium disappears.

607
00:39:45,040 --> 00:39:46,360
Unlike hydrogen and helium,

608
00:39:46,440 --> 00:39:48,920
which are fairly stable
on an atomic scale,

609
00:39:49,000 --> 00:39:51,120
lithium is a little bit fragile.

610
00:39:51,200 --> 00:39:54,200
It can actually be broken apart
into its components.

611
00:39:56,040 --> 00:39:58,400
As time goes by, these first stars

612
00:39:58,480 --> 00:40:01,400
manufacture a little
lithium on their own,

613
00:40:01,480 --> 00:40:03,040
but it doesn't last long.

614
00:40:04,640 --> 00:40:06,880
It is so fragile
that the instant it's made,

615
00:40:06,960 --> 00:40:10,440
it's destroyed once again by the
conditions in the core of the star.

616
00:40:12,280 --> 00:40:13,640
The lithium we have on Earth

617
00:40:13,720 --> 00:40:17,040
isn't made in a star
like iron, copper and iridium.

618
00:40:18,320 --> 00:40:21,200
Instead of fusing
lighter elements together,

619
00:40:21,280 --> 00:40:24,480
lithium is created
when larger atoms are blasted apart.

620
00:40:25,560 --> 00:40:27,840
The answer for where
lithium comes from

621
00:40:27,920 --> 00:40:31,000
is an amazing thing,
it's almost like a sci-fi answer.

622
00:40:31,080 --> 00:40:33,200
It kind of comes from
ray guns from space.

623
00:40:39,800 --> 00:40:44,680
The ray guns are supernovas
and their bullets are cosmic rays...

624
00:40:46,240 --> 00:40:48,960
..high-velocity particles
that streak through space

625
00:40:49,040 --> 00:40:50,680
at close to the speed of light.

626
00:40:51,800 --> 00:40:54,080
Cosmic rays are subatomic particles.

627
00:40:54,160 --> 00:40:58,240
They are atomic nuclei that
are accelerated to high speed

628
00:40:58,320 --> 00:40:59,840
in a supernova explosion.

629
00:41:01,000 --> 00:41:03,200
If another atomic nucleus
gets in the way,

630
00:41:03,280 --> 00:41:05,360
it can hit them and shatter them,

631
00:41:05,440 --> 00:41:09,040
and one of the pieces of shrapnel
from this explosion is lithium.

632
00:41:19,120 --> 00:41:21,160
The process is a bit
like going bowling,

633
00:41:21,240 --> 00:41:23,200
where the bowling ball
is the cosmic ray

634
00:41:23,280 --> 00:41:26,400
and the pins together
are some other atomic nucleus.

635
00:41:33,960 --> 00:41:36,680
When the bowling ball
smashes into the pins,

636
00:41:36,760 --> 00:41:38,920
it sends them
scattered in all directions...

637
00:41:43,280 --> 00:41:45,440
..and one of those pins
could be lithium.

638
00:41:57,880 --> 00:42:00,400
Cosmic rays are travelling
throughout all of space,

639
00:42:00,480 --> 00:42:02,120
between galaxies and in galaxies.

640
00:42:02,200 --> 00:42:04,480
So the cosmic rays
that are forming lithium

641
00:42:04,560 --> 00:42:06,360
by breaking other elements apart

642
00:42:06,440 --> 00:42:09,160
are literally doing it
in the space between the stars.

643
00:42:10,600 --> 00:42:14,680
Almost all the lithium on
Earth today was made this way,

644
00:42:14,760 --> 00:42:17,360
atom by atom
in the vastness of space.

645
00:42:18,480 --> 00:42:20,560
And then swept up
into the clouds of gas

646
00:42:20,640 --> 00:42:22,760
that formed our solar system.

647
00:42:29,800 --> 00:42:31,920
Oh, yeah, baby.

648
00:42:32,000 --> 00:42:36,040
For our cosmic car, this may
look like the end of the line,

649
00:42:36,120 --> 00:42:39,680
but the production line
for the universe keeps on rolling.

650
00:42:41,480 --> 00:42:42,840
This is pretty awesome.

651
00:42:42,920 --> 00:42:44,680
These atoms in this car here

652
00:42:44,760 --> 00:42:46,920
have been travelling
across the cosmos.

653
00:42:47,000 --> 00:42:49,840
They came to us from,
maybe, 13 billion years ago,

654
00:42:49,920 --> 00:42:52,680
a billion years after
the formation of the universe.

655
00:42:52,760 --> 00:42:53,840
Now guess what?

656
00:42:53,920 --> 00:42:57,200
They were used and we're returning
them back to where they came from.

657
00:42:58,280 --> 00:43:00,920
The atoms in our car
will not be in our car forever.

658
00:43:01,000 --> 00:43:03,160
In fact, our car will
probably be destroyed

659
00:43:03,240 --> 00:43:05,120
within a single human lifetime.

660
00:43:05,200 --> 00:43:06,520
Time to crush.

661
00:43:06,600 --> 00:43:08,800
It'll be recycled
into other things on Earth,

662
00:43:08,880 --> 00:43:12,240
but eventually, even the atoms
on Earth will be recycled

663
00:43:12,320 --> 00:43:13,880
with the rest of the cosmos.

664
00:43:18,520 --> 00:43:19,720
How cool was that?

665
00:43:21,440 --> 00:43:25,480
You could imagine my car
gets destroyed with the Earth

666
00:43:25,560 --> 00:43:28,160
and eventually makes its way
to another planet.

667
00:43:28,240 --> 00:43:32,000
It gets built into some
other kind of transportation mode

668
00:43:32,080 --> 00:43:33,160
by an alien race.

669
00:43:33,240 --> 00:43:34,880
I mean, that's totally possible,

670
00:43:34,960 --> 00:43:36,960
and I think that's
kind of a cool idea.

671
00:43:40,080 --> 00:43:42,960
From stars being born
billions of years ago,

672
00:43:43,040 --> 00:43:46,520
to cosmic rays,
to even the Big Bang itself.

673
00:43:46,600 --> 00:43:48,880
It's amazing to contemplate
all of the things

674
00:43:48,960 --> 00:43:52,360
that had to come together
in the universe for us to have cars.

675
00:43:52,440 --> 00:43:54,480
You really are driving around

676
00:43:54,560 --> 00:43:56,880
in the end product
of something that started

677
00:43:56,960 --> 00:43:58,720
13.7 billion years ago.

678
00:43:58,800 --> 00:44:03,440
That "new car" smell, that's
actually "old universe" smell,

679
00:44:03,520 --> 00:44:07,760
because that smell is traceable
all the way back to the Big Bang.

680
00:44:07,960 --> 00:44:08,960
subtitles by Deluxe

681
00:44:09,800 --> 00:44:11,080
How do you like that?

682
00:44:11,880 --> 00:44:13,880
That guarantees
the last word in the show.