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Did you ever stop to
wonder where your car came from?
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00:00:06,727 --> 00:00:10,131
I mean, really came from?
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00:00:10,131 --> 00:00:14,567
Every component has
a mind-blowing backstory,
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00:00:14,567 --> 00:00:17,606
an epic journey through
time and space
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00:00:17,606 --> 00:00:21,274
filled with the most violent
events since the big bang.
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00:00:23,144 --> 00:00:28,917
The history of your car
is the history of the universe.
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How old is your car?
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00:00:51,344 --> 00:00:54,179
My car is about 5 years old.
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00:00:54,179 --> 00:00:56,848
My car was assembled in 2001.
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00:00:56,850 --> 00:01:00,688
The car I drive is pretty old.
It was manufactured in 1991.
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00:01:00,689 --> 00:01:03,256
But that's just when the pieces
and parts were assembled.
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00:01:05,992 --> 00:01:08,829
To find out
how old a car really is,
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00:01:08,829 --> 00:01:13,534
we need to take a trip back
to the beginning of time.
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00:01:13,534 --> 00:01:17,772
Your car began its life
billions of years ago,
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00:01:17,774 --> 00:01:20,808
billions of miles away
in deep space.
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00:01:22,343 --> 00:01:24,980
The things that make up cars,
those atoms, most of them
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00:01:24,980 --> 00:01:27,817
were forged well before
our Earth was born.
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00:01:29,787 --> 00:01:32,822
You think your car is a clunker?
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00:01:32,823 --> 00:01:37,061
It's actually 13.8 billion
years old.
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00:01:39,264 --> 00:01:40,765
All right.
Let's do it, sir.
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00:01:44,002 --> 00:01:47,003
So, what's the stuff
that cars are made of?
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00:01:47,004 --> 00:01:49,843
Best way to find out...
Tear one apart.
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00:01:54,014 --> 00:01:58,252
Iron, plastics, oils and rubber
are the first to go...
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00:02:00,822 --> 00:02:02,290
In another half hour or so,
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00:02:02,290 --> 00:02:04,058
this baby's gonna be completely
stripped.
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00:02:05,492 --> 00:02:07,661
I can't wait to see it.
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00:02:09,097 --> 00:02:12,966
Then aluminum, silicon, copper.
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00:02:12,967 --> 00:02:15,135
And finally,
precious metals,
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00:02:15,137 --> 00:02:17,105
like platinum and gold.
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00:02:20,210 --> 00:02:24,615
Each of these materials is
crucial for building a car.
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00:02:27,751 --> 00:02:32,489
But in the earliest days of the
universe, none of them existed.
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00:02:41,299 --> 00:02:43,901
13.8 billion years ago,
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00:02:43,902 --> 00:02:48,740
time and space are
created in the big bang.
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00:02:48,740 --> 00:02:53,478
The early universe is filled
with nothing but energy.
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00:02:53,478 --> 00:02:57,983
After the big bang, it was
just a chaotic glob of stuff,
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00:02:57,984 --> 00:03:00,419
nothing like what you see today.
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00:03:00,419 --> 00:03:02,788
As the early universe cools,
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00:03:02,789 --> 00:03:06,927
the energy gives way to unstable
matter and antimatter,
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00:03:06,929 --> 00:03:12,032
then protons and neutrons
and, finally, atoms.
40
00:03:12,032 --> 00:03:16,771
But none of them are iron,
silicon or carbon.
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00:03:16,772 --> 00:03:20,742
The vast, gassy clouds
are mostly hydrogen.
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00:03:22,343 --> 00:03:25,248
Something had to happen
to give us everything else.
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00:03:25,250 --> 00:03:27,985
And everything was actually made
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00:03:27,985 --> 00:03:29,653
from hydrogen building blocks.
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00:03:32,223 --> 00:03:35,191
An atom of hydrogen
is the simplest and lightest
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00:03:35,192 --> 00:03:36,993
atom in the universe,
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00:03:36,995 --> 00:03:40,131
just a single positively
charged proton
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00:03:40,132 --> 00:03:42,802
bound to a single electron.
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00:03:44,403 --> 00:03:47,538
The universe then builds up
bigger atoms like carbon
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00:03:47,538 --> 00:03:51,110
and iron by fusing
hydrogen atoms together.
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00:03:52,513 --> 00:03:54,979
Everything starts
from simpler origins.
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00:03:54,980 --> 00:03:57,317
An iron atom is actually
lots and lots
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00:03:57,317 --> 00:04:00,754
of simple hydrogen
atoms that were stuck together.
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00:04:00,756 --> 00:04:05,056
At first, this
versatile proton building block
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00:04:05,057 --> 00:04:06,727
doesn't want to stick.
56
00:04:06,728 --> 00:04:09,195
Protons are positively charged.
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00:04:09,197 --> 00:04:11,932
So as you push them closer
together, they're gonna resist
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00:04:11,933 --> 00:04:13,335
coming closer together.
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00:04:13,336 --> 00:04:15,671
They really don't want
to hang out.
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00:04:15,673 --> 00:04:18,507
This repulsion makes
the early universe
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00:04:18,509 --> 00:04:23,312
a maelstrom of hydrogen atoms
swerving to avoid each other.
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00:04:23,312 --> 00:04:26,348
But if you can get them
to a point where you can
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00:04:26,350 --> 00:04:28,218
shove them together enough,
at some point,
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00:04:28,220 --> 00:04:29,987
they're gonna lock together.
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00:04:38,497 --> 00:04:41,365
Pushing atoms together
so strongly they stick
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00:04:41,367 --> 00:04:43,202
is called nuclear fusion.
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00:04:45,338 --> 00:04:48,341
It's the first step for turning
a universe full of gas
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00:04:48,341 --> 00:04:51,810
into one filled with
the ingredients for planets,
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00:04:51,812 --> 00:04:55,048
people, and cars.
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00:04:55,050 --> 00:04:58,483
So, how do you get
two atoms to fuse?
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00:04:58,485 --> 00:05:02,524
This guy's been doing it in his
garage since he was 14.
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00:05:04,560 --> 00:05:09,165
Taylor Wilson is obsessed
with nuclear fusion.
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00:05:11,468 --> 00:05:13,500
Yeah, the neighbors know
about the radioactive stuff
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00:05:13,500 --> 00:05:14,903
that's in the garage.
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00:05:14,904 --> 00:05:16,839
And so does the government.
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00:05:16,841 --> 00:05:19,007
It's all relatively low level.
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00:05:20,411 --> 00:05:21,810
That's my watch going off.
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00:05:21,812 --> 00:05:23,512
I think I'm the only person
I've ever met
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00:05:23,514 --> 00:05:25,449
with a geiger-counter watch.
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00:05:28,452 --> 00:05:31,355
The centerpiece
of Taylor's nuclear man cave
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00:05:31,355 --> 00:05:35,226
is this precision-engineered
fusion reactor,
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00:05:35,228 --> 00:05:37,827
which he built when he was still
in high school.
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00:05:37,829 --> 00:05:39,930
Okay, I'll let in
some gas now.
84
00:05:39,932 --> 00:05:43,134
The first ingredient...
Hydrogen gas.
85
00:05:43,134 --> 00:05:45,805
And it will be flowed into
the chamber through this very
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00:05:45,805 --> 00:05:48,673
precise sapphire leak valve.
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00:05:48,673 --> 00:05:52,877
The next ingredient...
High-voltage electricity.
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00:05:54,915 --> 00:05:56,682
Hmm.
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00:05:56,683 --> 00:05:58,985
Oh, I wonder
what the problem is.
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00:05:58,987 --> 00:06:00,956
- Power su...
- You probably want to plug it in.
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00:06:00,956 --> 00:06:03,255
Power supply is not plugged in.
Okay, let's try that again.
92
00:06:03,257 --> 00:06:04,860
That's embarrassing.
93
00:06:06,161 --> 00:06:08,831
I'm getting power
from the laundry room now.
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00:06:14,470 --> 00:06:18,740
Taylor passes a high voltage
through a small, spherical cage
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00:06:18,742 --> 00:06:21,310
that sits inside the reactor.
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00:06:21,312 --> 00:06:23,146
The negatively charged cage
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00:06:23,148 --> 00:06:26,350
quickly draws the hydrogen ions
inside it.
98
00:06:26,350 --> 00:06:28,086
So it's taking all those ions
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00:06:28,086 --> 00:06:29,586
and sucking them towards
the center.
100
00:06:29,586 --> 00:06:32,624
And as they fly in
they get confined,
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00:06:32,625 --> 00:06:35,495
and hopefully they collide
with each other and fuse.
102
00:06:35,495 --> 00:06:39,630
The temperature of the atoms
inside the cage is now so great
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00:06:39,632 --> 00:06:42,500
that hydrogen atoms are fusing
together,
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00:06:42,500 --> 00:06:46,172
creating heavier helium atoms
and a burst of energy
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00:06:46,173 --> 00:06:48,807
hotter than the surface
of the sun.
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00:06:48,807 --> 00:06:53,146
It's that little, tiny blob of
plasma inside those grid wires
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00:06:53,148 --> 00:06:55,582
that's kind of like a star
in a jar.
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00:07:02,790 --> 00:07:04,858
13 billion years ago,
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00:07:04,860 --> 00:07:07,761
the universe uses gravity
to fuse atoms
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00:07:07,762 --> 00:07:09,999
instead of an electrical cage.
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00:07:14,168 --> 00:07:17,774
Across the cosmos,
vast clouds of hydrogen gas
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00:07:17,776 --> 00:07:20,312
collapse under
their own gravity.
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00:07:21,646 --> 00:07:24,079
Pressure and temperature build
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00:07:24,081 --> 00:07:26,951
as more and more gas
gets sucked in.
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00:07:26,951 --> 00:07:30,021
Eventually, fusion sparks
deep in the core
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00:07:30,021 --> 00:07:32,290
of these giant balls of gas,
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00:07:32,290 --> 00:07:35,158
and the first stars start
to manufacture
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00:07:35,159 --> 00:07:38,999
many of the heavy elements that
make up your car today.
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00:07:40,701 --> 00:07:44,071
A star is basically a machine
for turning lighter elements
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00:07:44,072 --> 00:07:45,505
into heavier elements.
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00:07:47,740 --> 00:07:50,442
Fusion takes place
only inside the core
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00:07:50,442 --> 00:07:52,278
of these first stars,
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00:07:52,279 --> 00:07:56,216
fusing hydrogen atoms together
to create helium.
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00:07:56,216 --> 00:07:59,120
And when all the hydrogen
in the core is used up,
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00:07:59,120 --> 00:08:02,389
the star finds new fuel to burn.
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00:08:02,391 --> 00:08:06,360
After you burn hydrogen to form
helium, the core of the star
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00:08:06,362 --> 00:08:08,596
begins to collapse
and get hotter.
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00:08:08,598 --> 00:08:12,103
And there is enough energy
then to fuse three helium nuclei
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00:08:12,103 --> 00:08:13,970
into carbon.
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00:08:15,372 --> 00:08:18,408
And then that fuses
to form nitrogen, oxygen,
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00:08:18,410 --> 00:08:21,478
silicon, iron.
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00:08:21,480 --> 00:08:24,882
But this incredible
production line of elements
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can't go on forever.
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00:08:27,050 --> 00:08:29,019
The heavier atoms
you ram together,
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00:08:29,019 --> 00:08:30,855
the less energy
you get out.
136
00:08:30,855 --> 00:08:32,789
So you turn hydrogen
into helium.
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00:08:32,790 --> 00:08:35,360
Helium becomes carbon,
nitrogen, oxygen.
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00:08:35,360 --> 00:08:39,063
But every time there's a bit
less energy to be had
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00:08:39,065 --> 00:08:41,399
until you get to iron.
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00:08:41,400 --> 00:08:45,804
The iron that is in your car
is actually essentially
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00:08:45,806 --> 00:08:49,542
a deadly poison when it comes
to a star.
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00:08:49,543 --> 00:08:54,115
It's robbing that star of the
heat needed to keep itself up.
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00:08:58,519 --> 00:09:01,557
So the star collapses,
dies, and explodes
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00:09:01,557 --> 00:09:04,592
at the moment you create iron
in the core.
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00:09:04,594 --> 00:09:06,695
I mean, literally
the fraction of a second.
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00:09:06,696 --> 00:09:08,195
I'm not kidding.
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00:09:08,196 --> 00:09:12,235
That's how dramatic and weird
the steel in your car is.
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00:09:15,371 --> 00:09:18,308
The explosion,
called a supernova,
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00:09:18,309 --> 00:09:22,812
is one of the brightest and most
violent events in the universe.
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00:09:22,812 --> 00:09:27,150
It releases enough energy
to dwarf what the sun puts out
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00:09:27,152 --> 00:09:28,951
over its entire lifetime.
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00:09:28,952 --> 00:09:32,190
And all of the elements that it
has created are then dispersed
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00:09:32,191 --> 00:09:34,024
out into space.
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00:09:34,024 --> 00:09:36,827
The gassy remains
of the explosion are called
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00:09:36,828 --> 00:09:39,163
a supernova remnant,
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00:09:39,164 --> 00:09:41,567
an expanding bubble
of hydrogen gas
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00:09:41,567 --> 00:09:45,437
from the outer layers of the
star that mixes with stardust,
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00:09:45,438 --> 00:09:51,443
the carbon, oxygen, silicon
and iron from its core.
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00:09:51,445 --> 00:09:55,347
And this same
13-billion-year-old stardust
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00:09:55,349 --> 00:09:58,286
helped you drive to work
last week.
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00:09:58,287 --> 00:10:01,657
This was once in the core
of a dying star.
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00:10:01,658 --> 00:10:02,957
And who knows?
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00:10:02,958 --> 00:10:05,227
Maybe some of the iron atoms
in this brake disc
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00:10:05,229 --> 00:10:08,263
were forged in the heart of the
very first generation of stars
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00:10:08,264 --> 00:10:10,767
that illuminated the universe.
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00:10:10,768 --> 00:10:14,004
When you're pumpin' iron,
you're pumpin' a universe.
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00:10:20,044 --> 00:10:23,447
The first generation of stars
created the materials in a car's
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00:10:23,447 --> 00:10:27,019
chassis, body, windshield
and seats.
169
00:10:27,019 --> 00:10:30,120
But we're still missing key
components, like the copper
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00:10:30,121 --> 00:10:32,591
for the car's electronics.
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00:10:32,591 --> 00:10:36,227
To create this crucial metal,
a new generation of stars
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00:10:36,229 --> 00:10:39,700
must die an even stranger death.
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00:10:50,865 --> 00:10:54,668
Picture our universe
as the very first stars
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00:10:54,669 --> 00:10:56,972
come to the end
of their lives.
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00:10:57,572 --> 00:11:02,243
The early milky way
is filled with flashes
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00:11:02,244 --> 00:11:05,048
as star after star
explodes.
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00:11:06,881 --> 00:11:10,285
These violent supernovas hurl
a rich cocktail
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00:11:10,287 --> 00:11:13,056
of heavy elements
into space,
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00:11:13,057 --> 00:11:17,460
the carbon, silicon,
aluminum and iron atoms
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00:11:17,461 --> 00:11:21,067
that will one day build our
cars here on Earth.
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00:11:30,009 --> 00:11:32,076
But take a closer look
at today's cars,
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00:11:32,077 --> 00:11:34,678
and there are many
more elements heavier than iron,
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like copper in the wiring
184
00:11:37,851 --> 00:11:41,620
and gold in the connectors.
185
00:11:41,621 --> 00:11:44,825
How did the universe create
these heavy metals?
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00:11:44,826 --> 00:11:50,063
In the case of copper,
the answer is reincarnation.
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00:11:50,065 --> 00:11:54,235
Copper is one metal that
your car can't live without.
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00:11:54,235 --> 00:11:57,538
Turns out there's over a mile
of copper in the average car.
189
00:11:57,538 --> 00:12:01,475
And the reason why is because
copper is an excellent
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00:12:01,476 --> 00:12:03,080
electrical conductor.
191
00:12:05,950 --> 00:12:10,086
Copper's also used
to conduct heat in radiators.
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00:12:12,456 --> 00:12:15,860
It stops bearings from failing
when you need to go fast.
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00:12:15,860 --> 00:12:18,831
And when you need to stop,
copper provides the friction
194
00:12:18,831 --> 00:12:21,765
in your brake pads.
195
00:12:21,767 --> 00:12:25,202
But the story of how that copper
came to exist
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00:12:25,203 --> 00:12:28,241
and be on Earth, that's
a truly remarkable story.
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00:12:31,979 --> 00:12:36,384
Copper begins with the death
of a first-generation star.
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00:12:38,653 --> 00:12:42,422
The expanding supernova remnant
slams into neighboring clouds
199
00:12:42,423 --> 00:12:47,763
of gas, creating a shock wave
of pressure,
200
00:12:47,764 --> 00:12:51,365
giving birth to a new
generation of stars.
201
00:12:56,740 --> 00:12:59,142
There are cycles
to the universe.
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00:12:59,143 --> 00:13:01,409
Stars form.
They live out their lives.
203
00:13:01,410 --> 00:13:03,212
They die.
They blow off winds
204
00:13:03,214 --> 00:13:06,615
and they explode, ceding their
material into gas clouds
205
00:13:06,616 --> 00:13:10,320
which then form new stars
with heavier elements in them,
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00:13:10,321 --> 00:13:13,624
which will
repeat the cycle again.
207
00:13:13,625 --> 00:13:15,859
So if you want to think
about it that way,
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00:13:15,860 --> 00:13:18,063
the universe is
the ultimate recycler.
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00:13:20,932 --> 00:13:22,801
The hydrogen gas
that forms these
210
00:13:22,802 --> 00:13:26,171
second-generation stars is
peppered with the carbon,
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00:13:26,172 --> 00:13:30,278
aluminum and iron thrown out
by the supernova remnant.
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00:13:31,977 --> 00:13:35,347
The biggest of these dirty stars
burn brightly
213
00:13:35,349 --> 00:13:37,049
for a few million years.
214
00:13:37,051 --> 00:13:40,955
Then they undergo
an incredible metamorphosis.
215
00:13:46,094 --> 00:13:50,698
The star grows suddenly
to 100 times its previous size.
216
00:13:52,769 --> 00:13:58,273
Then it cools and turns
a ghostly red.
217
00:13:58,274 --> 00:14:01,410
The second-generation star
has transformed
218
00:14:01,412 --> 00:14:03,879
into a red supergiant.
219
00:14:03,879 --> 00:14:08,518
And it's in these diffuse outer
layers that iron-rich stardust
220
00:14:08,519 --> 00:14:11,956
is slowly converted
into copper...
221
00:14:11,956 --> 00:14:14,259
But not by fusion.
222
00:14:14,259 --> 00:14:17,293
That iron nucleus
has 26 protons.
223
00:14:17,294 --> 00:14:19,764
That's a serious
electric charge.
224
00:14:19,765 --> 00:14:23,001
So it's gonna repel any protons
we try to shoot in there.
225
00:14:25,104 --> 00:14:28,274
How do we get more protons in?
226
00:14:28,274 --> 00:14:32,447
The way we get those protons in
there is we trick the nucleus.
227
00:14:32,447 --> 00:14:35,783
Instead of shooting in protons,
we shoot in neutrons.
228
00:14:39,253 --> 00:14:42,756
Colliding atoms
in the outer layers of a star
229
00:14:42,758 --> 00:14:45,960
sometimes spit out neutrons.
230
00:14:45,961 --> 00:14:49,397
Neutrons don't have a charge,
so they're not repelled
231
00:14:49,398 --> 00:14:54,004
by the positively charged
protons in the iron stardust.
232
00:14:54,004 --> 00:14:58,509
So these neutrons can stick to
the other atoms around them.
233
00:15:00,809 --> 00:15:04,148
An atom is a very tiny thing.
It makes a very small target.
234
00:15:04,149 --> 00:15:07,152
But there's a lot of particles
flying around near a star.
235
00:15:07,153 --> 00:15:12,155
And if, by chance, a neutron
can hit an atom, it can stick.
236
00:15:12,157 --> 00:15:14,993
And that will actually make
the nucleus of the atom larger.
237
00:15:16,461 --> 00:15:19,130
Neutron by neutron
can hit an atom.
238
00:15:19,131 --> 00:15:23,469
And then that neutron can
actually decay into a proton.
239
00:15:23,470 --> 00:15:26,304
The neutron spits out
an electron,
240
00:15:26,306 --> 00:15:31,411
and what's left is a proton
and a new, bigger atom.
241
00:15:31,412 --> 00:15:33,713
In this case, copper.
242
00:15:33,715 --> 00:15:38,418
Scientists call this magical
transformation beta decay.
243
00:15:38,419 --> 00:15:41,788
So you can build up
heavy elements very slowly
244
00:15:41,789 --> 00:15:44,459
over the course of thousands
or millions of years
245
00:15:44,460 --> 00:15:45,927
just by capturing neutrons.
246
00:15:49,701 --> 00:15:52,772
Eventually, the core
of the red supergiant
247
00:15:52,773 --> 00:15:56,706
runs out of fuel,
and the star explodes,
248
00:15:56,707 --> 00:16:00,745
blasting its copper-rich
outer layer into space.
249
00:16:04,884 --> 00:16:08,486
Thanks to the life and death
of two generations of stars,
250
00:16:08,488 --> 00:16:11,359
we can now equip our car
with copper wiring.
251
00:16:15,495 --> 00:16:19,100
But we're still short of some
even heavier metals,
252
00:16:19,100 --> 00:16:20,801
such as lead for the battery
253
00:16:20,802 --> 00:16:23,437
and gold for the electrical
connectors.
254
00:16:26,173 --> 00:16:30,278
To make these truly massive
atoms, the universe must create
255
00:16:30,278 --> 00:16:34,850
the most spectacular explosions
since the big bang.
256
00:16:47,408 --> 00:16:52,144
To make a car, you
need some seriously heavy metal.
257
00:16:52,144 --> 00:16:56,783
Take iridium, a super-tough atom
with 77 protons
258
00:16:56,783 --> 00:17:00,154
that's used to coat the tips
of spark plugs.
259
00:17:03,993 --> 00:17:09,999
Next on the heavyweight lineup
comes gold with 79 protons.
260
00:17:10,000 --> 00:17:13,604
This shiny conductor resists
corrosion, making it ideal
261
00:17:13,605 --> 00:17:17,005
for exposed
electrical connections.
262
00:17:17,006 --> 00:17:21,078
These connectors here for this
airbag assembly are gold.
263
00:17:21,079 --> 00:17:23,480
And so this thing can react
really quickly
264
00:17:23,481 --> 00:17:25,317
if there is an accident
and save your life.
265
00:17:29,320 --> 00:17:34,326
The biggest atom in a car
is lead with 82 protons.
266
00:17:36,930 --> 00:17:40,799
Only lead has the durability
to deliver the short burst
267
00:17:40,800 --> 00:17:45,271
of high power needed to start
an engine over and over again.
268
00:17:52,146 --> 00:17:55,583
But until very recently,
how the universe made these
269
00:17:55,584 --> 00:17:59,153
oversized atoms
was a complete mystery.
270
00:17:59,153 --> 00:18:01,924
You can't make gold atoms
in a normal star.
271
00:18:03,527 --> 00:18:06,895
You can't make gold atoms in
a massive star that's dying.
272
00:18:08,565 --> 00:18:11,667
In order to make atoms this big
with this many neutrons,
273
00:18:11,669 --> 00:18:14,372
you need a truly cataclysmic
event.
274
00:18:18,710 --> 00:18:21,510
Just a few years ago,
most scientists believed
275
00:18:21,511 --> 00:18:25,817
that supernovas were cataclysmic
enough to do the job.
276
00:18:28,421 --> 00:18:32,124
But astronomer Edo Berger
was not so sure.
277
00:18:32,125 --> 00:18:35,594
If you open any one of these
books and flip to the page
278
00:18:35,595 --> 00:18:37,930
that tells you where gold
came from, it will tell you
279
00:18:37,931 --> 00:18:42,201
that gold came
from supernova explosions.
280
00:18:42,202 --> 00:18:44,336
But nobody had
directly observed supernovas
281
00:18:44,337 --> 00:18:46,439
producing elements like gold.
282
00:18:46,440 --> 00:18:49,576
And inside computer simulations,
virtual supernovas
283
00:18:49,577 --> 00:18:53,714
lacked the energy to forge
these oversized atoms.
284
00:18:53,715 --> 00:18:56,083
Clearly, something was wrong.
285
00:18:56,084 --> 00:18:59,319
But if supernovas weren't
powerful enough,
286
00:18:59,320 --> 00:19:01,589
what in the universe was?
287
00:19:01,590 --> 00:19:04,292
To form heavy elements
requires a lot of neutrons.
288
00:19:04,294 --> 00:19:07,930
And so another possible theory
was that the heaviest elements
289
00:19:07,931 --> 00:19:10,534
were produced in the mergers
of two neutron stars
290
00:19:10,535 --> 00:19:12,503
in a binary system.
291
00:19:15,506 --> 00:19:18,275
Neutron stars are some
of the weirdest objects
292
00:19:18,276 --> 00:19:20,176
in the universe.
293
00:19:20,178 --> 00:19:23,580
They're formed from the
collapsed cores of big stars
294
00:19:23,582 --> 00:19:25,516
when they die.
295
00:19:25,517 --> 00:19:28,053
You're taking a couple of
times the mass of the sun
296
00:19:28,054 --> 00:19:30,255
and squeezing it down
into a ball
297
00:19:30,256 --> 00:19:32,257
that's only a few miles across.
298
00:19:32,258 --> 00:19:34,660
The electrons and the protons
that are flitting around
299
00:19:34,661 --> 00:19:37,497
inside of that combine to form
neutrons.
300
00:19:37,498 --> 00:19:41,401
And what you're left with is
an extremely dense ball
301
00:19:41,402 --> 00:19:45,173
of neutrons
about the size of a city.
302
00:19:46,641 --> 00:19:49,643
Neutron stars
are extremely dense.
303
00:19:49,644 --> 00:19:53,247
If you take just a teaspoon of
the neutron star material,
304
00:19:53,248 --> 00:19:55,450
it's actually a billion tons.
305
00:19:55,451 --> 00:19:58,420
If neighboring stars
die together,
306
00:19:58,421 --> 00:20:01,923
it's possible for the two
neutron stars they leave behind
307
00:20:01,924 --> 00:20:05,626
to form a spinning binary pair.
308
00:20:05,627 --> 00:20:08,329
But the partnership is doomed.
309
00:20:08,330 --> 00:20:10,666
What you're left over
with is two incredibly
310
00:20:10,667 --> 00:20:13,838
compact dramatic objects
spiraling around each other.
311
00:20:16,840 --> 00:20:19,644
Over time they move in together,
312
00:20:19,645 --> 00:20:22,212
until finally they can
coalesce
313
00:20:22,213 --> 00:20:25,284
in the most violent explosion
since the big bang.
314
00:20:30,289 --> 00:20:34,792
The explosion is
called a neutron star merger.
315
00:20:34,794 --> 00:20:38,564
The amount of energy in this
explosion is crushing.
316
00:20:38,565 --> 00:20:40,733
There is almost no way
to describe it.
317
00:20:40,734 --> 00:20:43,136
It's like taking all
of the sun's energy
318
00:20:43,137 --> 00:20:45,406
that it will ever emit
over its entire lifetime
319
00:20:45,407 --> 00:20:47,777
and releasing it
in a single second.
320
00:20:53,114 --> 00:20:56,116
Berger suspects this
colossal explosion
321
00:20:56,117 --> 00:20:59,555
forges iridium,
gold and lead.
322
00:20:59,556 --> 00:21:03,893
But to rewrite the textbooks,
he needs hard evidence.
323
00:21:03,894 --> 00:21:07,194
It was difficult to, uh,
convince the community that this
324
00:21:07,195 --> 00:21:10,299
was a potential channel for the
production of heavy elements.
325
00:21:14,704 --> 00:21:17,575
The proof is to actually
see this process happening
326
00:21:17,576 --> 00:21:19,077
in the universe.
327
00:21:22,280 --> 00:21:24,147
June 2013...
328
00:21:24,148 --> 00:21:27,952
NASA's swift satellite spots
a short burst of gamma rays
329
00:21:27,953 --> 00:21:31,256
from a nearby galaxy,
330
00:21:31,257 --> 00:21:36,963
a sure sign that a neutron star
merger has just taken place.
331
00:21:36,964 --> 00:21:41,134
For Berger, it's the lucky break
he's been waiting for.
332
00:21:41,134 --> 00:21:42,868
As soon as we knew
that there was
333
00:21:42,869 --> 00:21:44,905
a gamma-ray burst nearby,
334
00:21:44,906 --> 00:21:49,076
we knew that this was our one
chance for perhaps several years
335
00:21:49,077 --> 00:21:51,912
to obtain the right kind
of measurements
336
00:21:51,913 --> 00:21:54,250
to test the formation
of heavy elements.
337
00:21:56,219 --> 00:21:58,654
Once swift had
identified the burst,
338
00:21:58,655 --> 00:22:03,127
the hubble space telescope swung
into action to capture images.
339
00:22:06,296 --> 00:22:08,798
We grabbed them right away,
and we just looked.
340
00:22:08,798 --> 00:22:10,333
We knew exactly where to look...
341
00:22:10,334 --> 00:22:12,201
At the center
of this red circle.
342
00:22:12,202 --> 00:22:15,239
And what we saw was this source
right there in the middle
343
00:22:15,240 --> 00:22:18,776
that is the direct signature
of the production
344
00:22:18,777 --> 00:22:21,413
of very heavy elements,
including gold.
345
00:22:25,352 --> 00:22:27,286
Berger's theory was right.
346
00:22:27,287 --> 00:22:31,825
But the rate of production was
way higher than he'd expected.
347
00:22:31,826 --> 00:22:33,259
Well, in that one event,
348
00:22:33,259 --> 00:22:34,759
the amount of gold
that was produced
349
00:22:34,760 --> 00:22:37,097
was more than the mass
of the Earth.
350
00:22:38,634 --> 00:22:41,000
If we can bring it all here,
it would be worth
351
00:22:41,001 --> 00:22:43,770
quadrillions and quadrillions
of dollars.
352
00:22:45,375 --> 00:22:47,241
The theory
is still very new,
353
00:22:47,242 --> 00:22:50,711
but it's possible that ancient
neutron star mergers
354
00:22:50,712 --> 00:22:53,848
made all the heavy metals
we see in the world today,
355
00:22:53,849 --> 00:22:58,121
including the last remaining
ingredients for our car.
356
00:23:07,030 --> 00:23:11,270
But all these elements are still
floating free in space.
357
00:23:13,305 --> 00:23:16,740
What's needed now
is to pull them all together
358
00:23:16,741 --> 00:23:20,314
into one giant
fabrication plant...
359
00:23:23,115 --> 00:23:24,916
The Earth.
360
00:23:37,455 --> 00:23:39,590
This is what
your car looked like
361
00:23:39,592 --> 00:23:41,925
before the Earth was born...
362
00:23:41,926 --> 00:23:46,066
Just a vast, swirling cloud of
gas and stardust,
363
00:23:46,067 --> 00:23:50,202
the exploded remains
of ancient stars.
364
00:23:50,203 --> 00:23:52,770
The clouds
between the stars of the galaxy
365
00:23:52,771 --> 00:23:54,942
are made of
everything that the Earth,
366
00:23:54,943 --> 00:23:56,676
your body, and your car
is made of.
367
00:23:56,677 --> 00:23:59,880
There's everything that you need
floating in gaseous form
368
00:23:59,881 --> 00:24:01,249
between the stars.
369
00:24:03,118 --> 00:24:05,185
Four and a half
billion years ago,
370
00:24:05,186 --> 00:24:08,457
the gas and dust collapse
once more.
371
00:24:10,092 --> 00:24:15,430
It ignites explosively
to create a new star... our Sun.
372
00:24:15,431 --> 00:24:17,566
Close to the young Sun,
373
00:24:17,567 --> 00:24:19,667
all of the lighter stuff
got blown away.
374
00:24:19,669 --> 00:24:22,673
What was left behind was
the heavier, denser stuff.
375
00:24:25,042 --> 00:24:27,444
There was carbon.
There was iron.
376
00:24:27,445 --> 00:24:29,848
There was gold...
Everything in between.
377
00:24:32,785 --> 00:24:35,386
Over time,
these free-floating elements
378
00:24:35,387 --> 00:24:37,154
begin to coalesce.
379
00:24:37,155 --> 00:24:39,257
Dust becomes rock.
380
00:24:39,258 --> 00:24:44,229
Rocks join to form larger
objects called planetesimals.
381
00:24:44,230 --> 00:24:48,403
Finally, planetesimals joined
to form the Earth.
382
00:24:53,307 --> 00:24:58,613
Our planet is born with all
the ingredients to build a car.
383
00:24:58,614 --> 00:25:03,554
But those ingredients are about
to go their separate ways.
384
00:25:05,020 --> 00:25:07,288
The Earth is a big planet.
385
00:25:07,289 --> 00:25:09,022
And it's done something that
not all planets do...
386
00:25:09,023 --> 00:25:12,828
It's differentiated.
It melted.
387
00:25:12,829 --> 00:25:15,597
Copper and lead
dissolve in sulfur
388
00:25:15,598 --> 00:25:18,599
and float to the top of
the molten Earth,
389
00:25:18,601 --> 00:25:22,105
making these metals
easy to mine today.
390
00:25:24,275 --> 00:25:27,778
But precious metals
like iridium and gold
391
00:25:27,778 --> 00:25:29,780
sink to the core of the Earth,
392
00:25:29,781 --> 00:25:33,050
and most of the iron
sinks with it.
393
00:25:33,051 --> 00:25:35,253
It's kind of a pain, actually.
All the heavy elements
394
00:25:35,255 --> 00:25:36,854
that are super useful,
like iron,
395
00:25:36,855 --> 00:25:38,356
they've sunk
to the middle of the Earth,
396
00:25:38,357 --> 00:25:39,925
where we can't reach them.
397
00:25:39,926 --> 00:25:41,929
And there's not a whole lot
of it in the crust.
398
00:25:47,834 --> 00:25:51,439
3.8 billion years ago,
the oceans form,
399
00:25:51,440 --> 00:25:54,374
and water dissolves
the last remaining traces
400
00:25:54,375 --> 00:25:57,545
of iron
from the Earth's surface.
401
00:25:57,546 --> 00:25:59,448
In fact, there was
so much iron in the sea
402
00:25:59,449 --> 00:26:01,415
that the Earth
would have been green,
403
00:26:01,416 --> 00:26:04,353
not blue like it is today.
404
00:26:04,354 --> 00:26:06,888
The Earth's crust
seems destined to be
405
00:26:06,890 --> 00:26:08,891
practically iron-free.
406
00:26:08,892 --> 00:26:15,767
Then, along comes the most
unlikely savior... green slime.
407
00:26:17,733 --> 00:26:20,605
I want to show you a couple
of examples of rocks
408
00:26:20,605 --> 00:26:23,641
that we recently brought back
from South Africa.
409
00:26:23,642 --> 00:26:26,477
Caltech geobiologist
Woody fischer
410
00:26:26,478 --> 00:26:28,378
traces the history of iron
411
00:26:28,380 --> 00:26:31,082
through the Earth's
earliest rocks.
412
00:26:31,083 --> 00:26:33,818
This is an example of a rock
that was deposited
413
00:26:33,819 --> 00:26:36,520
on the sea floor a little over
21/2 billion years ago.
414
00:26:36,521 --> 00:26:38,691
And there's not a lot of iron
in this sample.
415
00:26:38,692 --> 00:26:42,162
Now what's so interesting is,
you go to the same place
416
00:26:42,163 --> 00:26:45,197
on the Earth
200 million years later,
417
00:26:45,198 --> 00:26:48,000
and what you find is that things
have really changed.
418
00:26:48,001 --> 00:26:50,770
And you'll note this very
rusty color to it.
419
00:26:50,771 --> 00:26:53,240
This is from the presence
of iron oxides.
420
00:26:53,240 --> 00:26:58,712
And in fact the rock itself is
incredibly heavy, very dense.
421
00:26:58,713 --> 00:27:01,115
Why does the Earth's
geological record
422
00:27:01,116 --> 00:27:05,387
change so quickly
and so profoundly?
423
00:27:05,388 --> 00:27:09,390
One clue is that the sudden
appearance of iron-rich rocks
424
00:27:09,391 --> 00:27:13,699
coincides with the rise
of the first simple plants.
425
00:27:15,565 --> 00:27:19,567
This is a micro-organism
called a cyanobacterium.
426
00:27:19,568 --> 00:27:22,306
Each of the individual cells
that are present in that medium
427
00:27:22,307 --> 00:27:25,008
are green, and they're
conducting photosynthesis.
428
00:27:25,009 --> 00:27:30,213
This group cyanobacteria
is gathering energy from light,
429
00:27:30,214 --> 00:27:32,316
using that to split water.
430
00:27:32,317 --> 00:27:36,323
And in so doing, they produce
copious amounts of oxygen.
431
00:27:40,394 --> 00:27:43,462
In the early oceans,
this newly formed oxygen
432
00:27:43,463 --> 00:27:45,965
quickly binds
to the dissolved iron,
433
00:27:45,967 --> 00:27:50,269
forming a heavy rust that
settles on the ocean floor.
434
00:27:50,270 --> 00:27:52,806
For the first time in Earth's
history, there was oxygen...
435
00:27:52,807 --> 00:27:56,711
Free oxygen in the air.
That combined with the iron.
436
00:27:56,712 --> 00:27:59,482
And the iron basically sank
to the bottom of the ocean.
437
00:28:01,884 --> 00:28:04,220
These ancient,
rusty deposits
438
00:28:04,221 --> 00:28:07,521
formed the iron ore we dig out
of the ground
439
00:28:07,522 --> 00:28:10,960
to make cars
2 billion years later.
440
00:28:10,961 --> 00:28:13,096
So in the process
of making a car,
441
00:28:13,097 --> 00:28:14,830
mining the iron ore,
442
00:28:14,832 --> 00:28:17,435
life was an essential part
of that first step.
443
00:28:19,203 --> 00:28:22,106
You have to wait until
after these guys evolve
444
00:28:22,107 --> 00:28:24,241
in order to be able
to concentrate
445
00:28:24,242 --> 00:28:25,979
the raw materials
that you need.
446
00:28:34,487 --> 00:28:37,422
The life of early plants
brought us iron.
447
00:28:37,423 --> 00:28:41,362
But their death is perhaps
even more helpful
448
00:28:41,363 --> 00:28:46,402
because without dead plants,
your car isn't going anywhere.
449
00:28:48,537 --> 00:28:50,237
So, what's the final ingredient
450
00:28:50,238 --> 00:28:52,940
for getting a car
to actually go?
451
00:28:52,941 --> 00:28:54,808
You need to add fuel.
452
00:28:54,809 --> 00:28:57,813
And we, right now,
use hydrocarbon-based fuel.
453
00:28:57,814 --> 00:29:00,015
We use oil.
454
00:29:00,016 --> 00:29:04,153
Oil is actually the remnant
of dead plant life
455
00:29:04,154 --> 00:29:07,190
from billions of years ago.
456
00:29:07,191 --> 00:29:09,993
It amazes me to think that, as
you're driving your car around,
457
00:29:09,994 --> 00:29:15,365
what you're actually running
the car on is ancient dead life.
458
00:29:15,366 --> 00:29:18,536
These hydrocarbons
are also processed
459
00:29:18,537 --> 00:29:22,642
to help make rubber and plastics
for the tires and interior trim.
460
00:29:29,648 --> 00:29:32,550
Now we have almost
all of the components needed
461
00:29:32,551 --> 00:29:34,720
to complete a car.
462
00:29:34,721 --> 00:29:40,326
All that remains is a spark
to bring the engine to life.
463
00:29:40,327 --> 00:29:42,461
But to get that spark,
464
00:29:42,462 --> 00:29:46,166
the Earth must pay
a catastrophic price.
465
00:29:59,000 --> 00:30:01,402
65 million years ago,
466
00:30:01,403 --> 00:30:04,372
the Earth's crust
had all the materials needed
467
00:30:04,373 --> 00:30:07,608
to build a car
except for one crucial group
468
00:30:07,609 --> 00:30:10,146
of supertough metals.
469
00:30:11,680 --> 00:30:13,682
This is a spark plug.
470
00:30:13,682 --> 00:30:17,653
And the way it works is that
100,000 volts are put across
471
00:30:17,653 --> 00:30:18,672
this gap here.
472
00:30:19,690 --> 00:30:23,893
And that ignites gasoline vapor
in the cylinder of your motor.
473
00:30:25,328 --> 00:30:28,365
This tip has to survive
in very harsh conditions.
474
00:30:30,103 --> 00:30:34,672
So it must be made of a very,
very sturdy, robust material.
475
00:30:34,673 --> 00:30:36,941
And the material
in this spark plug
476
00:30:36,942 --> 00:30:38,980
is a metal known as iridium.
477
00:30:42,582 --> 00:30:45,416
Like other heavy
metals such as gold and lead,
478
00:30:45,417 --> 00:30:48,520
iridium is born inside
the exploded remains
479
00:30:48,521 --> 00:30:51,289
of neutron stars.
480
00:30:51,290 --> 00:30:55,128
And when the Earth forms, plenty
of iridium is in the mix.
481
00:30:55,130 --> 00:30:57,798
But it quickly
sinks out of reach
482
00:30:57,799 --> 00:31:00,036
while the Earth
is still molten,
483
00:31:00,037 --> 00:31:04,105
falling to the core under
the influence of gravity.
484
00:31:04,106 --> 00:31:07,877
So, where does the iridium
come from that we mine today?
485
00:31:12,648 --> 00:31:17,085
This exposed rock face
in Colorado reveals a clue,
486
00:31:17,086 --> 00:31:20,991
a mysterious layer in
the Earth's geological record
487
00:31:20,992 --> 00:31:23,727
that wraps around
the entire planet.
488
00:31:23,728 --> 00:31:25,329
There's something
particularly interesting
489
00:31:25,330 --> 00:31:27,031
about this Clay layer here.
490
00:31:27,032 --> 00:31:29,434
If you analyze the concentration
of rare metals
491
00:31:29,435 --> 00:31:31,270
like iridium in this layer,
492
00:31:31,271 --> 00:31:34,172
you'll find that there's about
100 times as much iridium here
493
00:31:34,173 --> 00:31:37,476
as in the other rocks around us
in the crust of the Earth.
494
00:31:37,477 --> 00:31:40,079
It's rather bizarre, actually,
to find so much iridium
495
00:31:40,080 --> 00:31:42,949
concentrated in one place
here in crustal rocks.
496
00:31:42,950 --> 00:31:45,852
And it turns out that the entire
budget of the iridium
497
00:31:45,853 --> 00:31:48,222
in the Earth's crust is pretty
much contained in this layer.
498
00:31:51,192 --> 00:31:53,460
When geologists
discovered the iridium layer
499
00:31:53,461 --> 00:31:56,262
in the late '70s,
it became one of the biggest
500
00:31:56,263 --> 00:31:58,767
mysteries in science.
501
00:31:58,768 --> 00:32:02,604
How could so much of this
rare metal end up
502
00:32:02,605 --> 00:32:06,041
concentrated
in such a thin layer?
503
00:32:08,711 --> 00:32:12,181
Only astronomers had measured
such high concentrations
504
00:32:12,182 --> 00:32:15,116
of iridium before,
inside rocks
505
00:32:15,117 --> 00:32:18,654
originating
in the asteroid belt.
506
00:32:18,655 --> 00:32:20,691
Billions of years ago,
planets were forming
507
00:32:20,692 --> 00:32:22,326
all over our solar system.
508
00:32:22,327 --> 00:32:24,997
But there was an area
in between Mars and Jupiter
509
00:32:24,998 --> 00:32:27,631
where the gravity of Jupiter
pretty much pulled apart
510
00:32:27,632 --> 00:32:29,299
anything that tried to form.
511
00:32:29,300 --> 00:32:32,270
And what got left over were
a bunch of large, rocky chunks
512
00:32:32,271 --> 00:32:34,606
that we call the asteroid belt.
513
00:32:34,607 --> 00:32:38,344
Now, some of the asteroid belt
is made of rock.
514
00:32:38,345 --> 00:32:41,315
Other asteroids are richer
in metals.
515
00:32:43,617 --> 00:32:45,251
From time to time,
516
00:32:45,252 --> 00:32:47,521
asteroids can get
thrown out of orbit
517
00:32:47,522 --> 00:32:52,859
by another asteroid, or by the
long reach of Jupiter's gravity.
518
00:32:52,861 --> 00:32:57,732
And sometimes, they smash
into the Earth.
519
00:32:57,733 --> 00:33:00,001
Is it possible the iridium layer
was simply
520
00:33:00,002 --> 00:33:02,903
the scattered
remains of a single, giant
521
00:33:02,904 --> 00:33:05,775
metal-rich asteroid impact?
522
00:33:05,776 --> 00:33:09,247
30 years ago, this sounded
like a crazy idea.
523
00:33:11,213 --> 00:33:13,718
Only an asteroid
the size of a city
524
00:33:13,719 --> 00:33:15,384
would have had enough power
525
00:33:15,385 --> 00:33:18,522
to blast debris
around the entire planet.
526
00:33:24,230 --> 00:33:26,798
If you can imagine
the magnitude, the enormity
527
00:33:26,798 --> 00:33:28,700
of the violence of an event
like that,
528
00:33:28,701 --> 00:33:31,971
and to have inches of dusty
debris
529
00:33:31,971 --> 00:33:34,506
come booming over the horizon
and settling out of the sky
530
00:33:34,507 --> 00:33:37,910
and raining on top of you
and burying you in this layer,
531
00:33:37,911 --> 00:33:41,148
that should make a pretty big
crater someplace on the Earth.
532
00:33:42,451 --> 00:33:43,750
Although it sounded crazy,
533
00:33:43,751 --> 00:33:46,618
the asteroid hypothesis
also solved
534
00:33:46,619 --> 00:33:49,589
a longstanding mystery.
535
00:33:49,590 --> 00:33:53,660
The dinosaurs were wiped out
around the same time
536
00:33:53,661 --> 00:33:55,663
the iridium layer
was laid down.
537
00:33:57,266 --> 00:33:59,769
Could the two events be linked?
538
00:33:59,769 --> 00:34:03,038
The puzzle was solved
when an asteroid impact crater
539
00:34:03,038 --> 00:34:05,674
was discovered
down in the Yucatan.
540
00:34:05,675 --> 00:34:08,777
The crater age turned out to be
exactly 65 million years old,
541
00:34:08,777 --> 00:34:10,746
the same age as this deposit.
542
00:34:10,746 --> 00:34:14,418
And the crater's size turned out
to be just the size
543
00:34:14,418 --> 00:34:17,420
of crater you would get from
the size of an asteroid
544
00:34:17,422 --> 00:34:19,822
it would take
to make this layer.
545
00:34:19,824 --> 00:34:23,027
So it turns out that,
in a lot of ways, you can think
546
00:34:23,027 --> 00:34:25,730
of asteroids as sort of a cosmic
iridium-delivery system
547
00:34:25,731 --> 00:34:27,865
for us here on the surface
of the Earth.
548
00:34:27,867 --> 00:34:29,802
And it's not just iridium
549
00:34:29,802 --> 00:34:31,739
we have to thank asteroids for.
550
00:34:31,739 --> 00:34:33,639
There were
probably several times
551
00:34:33,639 --> 00:34:35,440
in the history of our
solar system where there was
552
00:34:35,442 --> 00:34:37,945
heavy bombardment, all kinds
of asteroids and comets
553
00:34:37,945 --> 00:34:39,846
falling in towards the Earth.
554
00:34:39,847 --> 00:34:42,449
Well, the Earth had solidified
to some degree by that time.
555
00:34:42,451 --> 00:34:45,018
So not everything sank down
into the core.
556
00:34:45,018 --> 00:34:47,355
So some of the metals
we find around us
557
00:34:47,356 --> 00:34:49,824
are products of this
later era of bombardment.
558
00:34:53,260 --> 00:34:55,764
The Earth's history
is a violent one.
559
00:34:55,766 --> 00:34:58,768
Over the course of time,
we have been hit over and over
560
00:34:58,769 --> 00:35:01,838
and over again by asteroids
of all sizes.
561
00:35:01,838 --> 00:35:04,708
Some of them have actually
delivered quite a bit
562
00:35:04,708 --> 00:35:06,610
of heavy elements to the surface
of the Earth.
563
00:35:09,036 --> 00:35:11,036
These asteroid-borne
materials
564
00:35:11,038 --> 00:35:14,405
include most of the gold,
platinum and nickel
565
00:35:14,407 --> 00:35:16,242
we use in cars today.
566
00:35:18,043 --> 00:35:22,014
Asteroid impacts will form
little pockets of concentrations
567
00:35:22,014 --> 00:35:24,985
of some of those ore minerals
and ore metals for us
568
00:35:24,985 --> 00:35:28,420
that we can then mine in greater
abundance on the surface.
569
00:35:28,422 --> 00:35:31,057
In many cases, when you
go to a mine to dig up
570
00:35:31,059 --> 00:35:33,561
these heavy elements,
what you are doing
571
00:35:33,563 --> 00:35:36,297
is tapping into
an asteroid impact.
572
00:35:42,605 --> 00:35:44,606
Metal-rich asteroids
are the final piece
573
00:35:44,606 --> 00:35:46,076
of the puzzle.
574
00:35:47,545 --> 00:35:50,079
We can now reconstruct
the journey of every atom
575
00:35:50,081 --> 00:35:53,481
of our car
through time and space
576
00:35:53,483 --> 00:35:55,684
from the moment of the big bang
577
00:35:55,686 --> 00:35:59,657
through generations of stars
to the birth of the Earth
578
00:35:59,657 --> 00:36:03,695
and, eventually,
the showroom floor.
579
00:36:03,695 --> 00:36:06,699
Over the course
of the multiple supernovae
580
00:36:06,701 --> 00:36:10,400
in our universe and the birth
and death of stars,
581
00:36:10,402 --> 00:36:13,273
we were able to collect all
of the materials needed
582
00:36:13,273 --> 00:36:16,476
to assemble these cars.
583
00:36:16,476 --> 00:36:17,945
That's pretty fantastic.
584
00:36:20,581 --> 00:36:23,885
I think we don't fully
appreciate how complicated
585
00:36:23,885 --> 00:36:25,887
the elements that make up
our car really are
586
00:36:25,887 --> 00:36:29,490
and how special they are.
They really are star stuff.
587
00:36:39,501 --> 00:36:41,302
But not every car
is like the one
588
00:36:41,304 --> 00:36:43,804
we've just pulled apart.
589
00:36:43,806 --> 00:36:47,344
These days, not every car
runs on gas.
590
00:36:49,447 --> 00:36:53,449
And electric vehicles require
a magical element
591
00:36:53,449 --> 00:36:57,489
that's made in space
by cosmic ray guns.
592
00:37:05,864 --> 00:37:09,835
This car
doesn't have a gas tank.
593
00:37:09,835 --> 00:37:13,909
It's part of a new generation
of electric vehicles.
594
00:37:17,411 --> 00:37:19,445
The key to these high-tech cars
595
00:37:19,445 --> 00:37:21,815
are their rechargeable
batteries,
596
00:37:21,817 --> 00:37:26,054
a technology that relies on one
of the Earth's rarest metals.
597
00:37:28,090 --> 00:37:31,260
This here is a battery pack
from an electric car.
598
00:37:31,262 --> 00:37:35,096
And in today's electric cars,
the metal of choice is lithium.
599
00:37:35,097 --> 00:37:39,603
And lithium has one of the most
amazing stories in the universe.
600
00:37:42,273 --> 00:37:45,041
After hydrogen and helium,
601
00:37:45,043 --> 00:37:47,510
lithium is the lightest element,
602
00:37:47,512 --> 00:37:50,748
with just three protons
and four neutrons.
603
00:37:50,748 --> 00:37:54,851
Its lightness makes it ideal
for electric cars.
604
00:37:54,851 --> 00:37:58,389
If the battery weighs more
than the car, then we are just
605
00:37:58,391 --> 00:38:00,592
wasting energy on moving
the battery around.
606
00:38:00,594 --> 00:38:02,762
If we can build a light battery,
607
00:38:02,762 --> 00:38:04,797
for example a lithium-ion
battery,
608
00:38:04,797 --> 00:38:08,201
then we can provide the power
without the penalty
609
00:38:08,202 --> 00:38:10,269
of having to carry
those heavy batteries
610
00:38:10,271 --> 00:38:11,572
along with the car.
611
00:38:13,942 --> 00:38:15,577
Lithium is rapidly becoming
612
00:38:15,577 --> 00:38:18,311
one of the most sought-after
metals on Earth.
613
00:38:18,311 --> 00:38:21,548
But it's also
a cosmic curiosity.
614
00:38:23,552 --> 00:38:26,221
The big bang creates a trace
of lithium.
615
00:38:26,222 --> 00:38:31,260
But as the first stars form,
this lithium disappears.
616
00:38:31,260 --> 00:38:34,264
Unlike hydrogen and helium,
which are fairly stable
617
00:38:34,264 --> 00:38:37,967
on an atomic scale, lithium is
a little bit fragile.
618
00:38:37,967 --> 00:38:40,838
It can actually be broken apart
into its components.
619
00:38:42,472 --> 00:38:46,041
As time goes by,
these first stars manufacture
620
00:38:46,043 --> 00:38:50,715
a little lithium on their own,
but it doesn't last long.
621
00:38:50,715 --> 00:38:53,518
It is so fragile that,
the instant it's made,
622
00:38:53,518 --> 00:38:55,653
it's destroyed once again by
the conditions
623
00:38:55,655 --> 00:38:58,590
in the core of the star.
624
00:38:58,592 --> 00:39:01,893
So, how does the
universe fuse together atoms
625
00:39:01,894 --> 00:39:03,460
to form lithium?
626
00:39:03,461 --> 00:39:05,931
Surprisingly, it doesn't.
627
00:39:05,931 --> 00:39:07,768
It blasts them apart.
628
00:39:12,039 --> 00:39:13,907
The answer for where
lithium comes from
629
00:39:13,909 --> 00:39:15,507
is an amazing thing.
630
00:39:15,509 --> 00:39:17,210
It's almost like
a Sci-Fi answer.
631
00:39:17,211 --> 00:39:19,914
It kind of comes
from ray guns from space.
632
00:39:26,987 --> 00:39:29,423
The ray guns are supernovas.
633
00:39:29,425 --> 00:39:34,164
And their bullets are cosmic
rays, high-velocity particles
634
00:39:34,164 --> 00:39:38,266
that streak through space
at close to the speed of light.
635
00:39:38,268 --> 00:39:40,971
Cosmic rays
are subatomic particles.
636
00:39:40,972 --> 00:39:44,539
They are atomic nuclei that
are accelerated to high speed
637
00:39:44,541 --> 00:39:47,376
in a supernova explosion.
638
00:39:47,378 --> 00:39:50,648
If another atomic nucleus gets
in the way, it can hit them
639
00:39:50,648 --> 00:39:52,150
and shatter them.
640
00:39:52,150 --> 00:39:54,686
And one of the pieces of
shrapnel from this explosion
641
00:39:54,686 --> 00:39:56,623
is lithium.
642
00:40:05,371 --> 00:40:08,273
The process is a bit like going
bowling, where the bowling ball
643
00:40:08,273 --> 00:40:11,510
is the cosmic ray, and the pins
together are some other
644
00:40:11,510 --> 00:40:13,313
atomic nucleus.
645
00:40:19,887 --> 00:40:23,157
When the bowling ball
smashes into the pins,
646
00:40:23,157 --> 00:40:25,827
it sends them
scattered in all directions.
647
00:40:29,297 --> 00:40:31,768
And one of those pins
could be lithium.
648
00:40:44,114 --> 00:40:46,648
Cosmic rays are traveling
throughout all of space,
649
00:40:46,648 --> 00:40:48,485
between galaxies
and in galaxies.
650
00:40:48,487 --> 00:40:50,554
So the cosmic rays that are
forming lithium
651
00:40:50,556 --> 00:40:52,456
by breaking
other elements apart
652
00:40:52,458 --> 00:40:55,460
are literally doing it
in the space between the stars.
653
00:40:57,097 --> 00:40:59,431
Almost all the lithium
on Earth today
654
00:40:59,431 --> 00:41:03,835
was made this way, atom by
atom in the vastness of space,
655
00:41:03,835 --> 00:41:06,838
and then swept up
into the clouds of gas
656
00:41:06,840 --> 00:41:08,842
that formed our solar system.
657
00:41:15,983 --> 00:41:17,784
Oh, yeah, baby.
658
00:41:17,784 --> 00:41:22,322
For our cosmic car, this may
look like the end of the line.
659
00:41:22,324 --> 00:41:25,025
But the production line
for the universe,
660
00:41:25,027 --> 00:41:27,994
that keeps on rolling.
661
00:41:27,996 --> 00:41:29,429
This is pretty awesome.
662
00:41:29,431 --> 00:41:32,099
These atoms in this car here
have been traveling
663
00:41:32,101 --> 00:41:33,603
across the cosmos.
664
00:41:33,603 --> 00:41:36,306
They came to us from maybe
13 billion years ago,
665
00:41:36,306 --> 00:41:38,974
a billion years after
the formation of the universe.
666
00:41:38,976 --> 00:41:40,710
And now, guess what?
They were used,
667
00:41:40,711 --> 00:41:42,681
and we're returning them back
to where they came from.
668
00:41:44,414 --> 00:41:47,284
The atoms in our car will not
be in our car forever.
669
00:41:47,284 --> 00:41:49,452
In fact, our car will probably
be destroyed
670
00:41:49,454 --> 00:41:51,288
within a single human lifetime.
671
00:41:51,289 --> 00:41:52,755
Time to crush.
672
00:41:52,757 --> 00:41:54,990
It'll be recycled into other
things on Earth.
673
00:41:54,992 --> 00:41:57,963
But eventually, even the atoms
on Earth will be recycled
674
00:41:57,963 --> 00:41:59,565
with the rest of the cosmos.
675
00:42:04,503 --> 00:42:05,940
How cool was that?
676
00:42:07,708 --> 00:42:11,844
You could imagine my car
gets destroyed with the Earth,
677
00:42:11,846 --> 00:42:14,581
and eventually it makes its way
to another planet.
678
00:42:14,581 --> 00:42:17,884
It gets built into some other
kind of transportation mode
679
00:42:17,885 --> 00:42:20,755
by an alien race...
I mean, that's totally possible.
680
00:42:20,755 --> 00:42:24,161
And I think that's kind of
a cool idea.
681
00:42:26,596 --> 00:42:29,264
From stars being born billions
of years ago
682
00:42:29,266 --> 00:42:32,969
to cosmic rays
to even the big bang itself,
683
00:42:32,969 --> 00:42:35,172
it's amazing to contemplate
all of the things
684
00:42:35,172 --> 00:42:37,005
that had to come together
in the universe
685
00:42:37,005 --> 00:42:38,773
for us to have cars.
686
00:42:38,773 --> 00:42:40,476
You really are driving around
687
00:42:40,478 --> 00:42:42,612
in the end product
of something that started
688
00:42:42,614 --> 00:42:44,880
13.7 billion years ago.
689
00:42:44,882 --> 00:42:46,748
That new-car smell?
690
00:42:46,750 --> 00:42:49,688
That's actually old-universe
smell
691
00:42:49,688 --> 00:42:52,858
because that smell is
traceable all the way back
692
00:42:52,860 --> 00:42:55,527
to the big bang.
693
00:42:55,527 --> 00:42:58,362
How you like that?
694
00:42:58,364 --> 00:43:01,034
That guarantees the last word
in a... in a show.
695
00:43:01,034 --> 00:43:02,135
Okay, yeah.
56780
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