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00:00Did you ever stop to wonder where your car came from?
00:07Where it really came from?
00:10Every component has been on a mind-blowing journey through time, space, and the most
00:17violent cosmic events since the Big Bang.
00:22The history of your car is the history of the universe.
00:48How old is a car?
00:51My car is about five years old.
00:53My car was assembled in 2001.
00:56The car I drive is pretty old.
00:57It was manufactured in 1991, but that's just when the pieces and parts were assembled.
01:04The materials that make up the cars we drive today were created long before 1991.
01:13Your car began its life billions of years ago, billions of miles away in deep space.
01:21The things that make up cars, those atoms, most of them were forged well before our earth
01:26was born.
01:29You think your car is a clunker?
01:32It's actually 13.8 billion years old.
01:36All right, let's do it, sir.
01:43The best way to find out what a car is made out of is to tear one apart.
01:50Iron, plastics, oils, and rubber are the first to be removed.
02:00Another half hour or so, this baby's going to be completely stressed.
02:05I can't wait to see it.
02:08Then aluminum, silicon, copper, and finally precious metals like platinum and gold.
02:19Each of these materials is crucial for building a car.
02:27But in the earliest days of the universe, none of them existed.
02:4013.8 billion years ago, the universe was born in a monumental event, the Big Bang.
02:48The early universe was filled with nothing but energy.
02:53After the Big Bang, it was just a chaotic glob of stuff, nothing like what you see today.
03:00As the early universe cooled, the energy gave way to unstable matter and antimatter, then
03:06protons and neutrons, and finally, atoms.
03:13But not the iron, silicon, or carbon atoms that we use in a car.
03:17The universe was almost entirely made up of hydrogen.
03:22Energy had to happen to give us everything else.
03:25And everything was actually made from hydrogen building blocks.
03:32An atom of hydrogen is the simplest and lightest atom in the universe, just a single positively
03:37charged proton bound to a single electron.
03:43The universe built up bigger atoms, such as carbon and iron, by joining hydrogen atoms
03:48together.
03:52Everything starts from simpler origins.
03:54An iron atom is actually lots and lots of simple hydrogen atoms that were stuck together.
04:00But hydrogen atoms don't naturally stick together.
04:06Protons are positively charged.
04:08So as you push them closer together, they're going to resist coming closer together.
04:12They really don't want to hang out.
04:15This repulsion makes the early universe a maelstrom of hydrogen atoms swerving to avoid
04:20each other.
04:23But if you can get them to a point where you can shove them together enough, at some point,
04:27they're going to lock together.
04:38Getting atoms together so strongly that they fuse is called nuclear fusion.
04:44It's the first step in turning a universe full of gas into one filled with the ingredients
04:49for planets, people, and cars.
04:54Getting two atoms to fuse is child's play.
04:58At least, it is if your name's Taylor Wilson.
05:03Taylor's been fusing atoms in his garage since he was 14.
05:08Yeah, the neighbors know about the radioactive stuff that's in the garage.
05:13And so does the government.
05:16It's all relatively low level.
05:19It's my watch going off.
05:20I think I'm the only person I've ever met with a Geiger counter watch.
05:27The centerpiece of Taylor's nuclear man cave is a precision-engineered fusion reactor,
05:34which he built when he was still in high school.
05:36OK, I'll let in some gas now.
05:39The first ingredient, hydrogen gas.
05:42And it will be flowed into the chamber through this very precise sapphire leak valve.
05:47The next ingredient, high-voltage electricity.
05:52Hmm.
05:55Oh, I wonder what the problem is.
05:58Power supply's not plugged in.
06:00OK, let's try that again.
06:02That's embarrassing.
06:04OK, we're going to get power from the laundry room now.
06:12Taylor passes a high voltage through a small spherical cage that sits inside the reactor.
06:19The negatively charged cage quickly pulls the hydrogen ions towards it.
06:25So it's taking all those ions and sucking them towards the center.
06:28And as they fly in, they get confined, and hopefully they collide with each other and fuse.
06:34The temperature of the atoms inside the cage is now so great that hydrogen atoms are fusing together,
06:41creating heavier helium atoms and a burst of energy hotter than the surface of the sun.
06:47That little tiny blob of plasma inside those grid wires, that's kind of like a star in a jar.
07:0113 billion years ago, the universe used gravity instead of an electrical cage to fuse atoms together.
07:09Across the cosmos, vast clouds of hydrogen gas collapsed under their own gravity.
07:17Pressure and temperature built as more and more gas was sucked in.
07:23Eventually, fusion sparked deep in the core of these giant balls of gas.
07:29And the first stars started to manufacture many of the heavy elements that make up cars today.
07:39A star is basically a machine for turning lighter elements into heavier elements.
07:45Fusion took place inside the core of these first stars, fusing hydrogen atoms together to create helium.
07:53And when all the hydrogen in the core had been used up, the star finds new fuel to burn.
08:00After you burn hydrogen to form helium, the core of the star begins to collapse and get hotter.
08:07And there is enough energy then to fuse three helium nuclei into carbon.
08:13And then that fuses to form nitrogen, oxygen, silicon, iron.
08:19But this incredible production line of elements can't go on forever.
08:25The heavier atoms you ram together, the less energy you get out.
08:29So you turn hydrogen into helium, helium becomes carbon, nitrogen, oxygen.
08:34But every time there's a bit less energy to be had until you get to iron.
08:40The iron that is in your car is actually essentially a deadly poison when it comes to a star.
08:48It's robbing that star of the heat needed to keep itself up.
08:57So the star collapses, dies and explodes at the moment you create iron in the core.
09:03I mean literally the fraction of a second. I'm not kidding.
09:06That's how dramatic and weird the steel in your car is.
09:13The explosion, called a supernova, is one of the brightest and most violent events in the universe.
09:21It releases enough energy to dwarf what the sun puts out over its entire lifetime.
09:27And all of the elements that it has created are then dispersed out into space.
09:33The gassy remains of the explosion are called a supernova remnant.
09:37An expanding bubble of gas containing hydrogen that survived in the star's outer layers,
09:43mixed in with carbon, oxygen, silicon and iron from the star's core.
09:50This 13 billion year old stardust helped you drive to work last week.
09:57This was once in the core of a dying star.
10:00And who knows, maybe some of the iron atoms in this brake disc
10:03were forged in the heart of the very first generation of stars that illuminated the universe.
10:09You're pumping iron, you're pumping the universe.
10:19The first stars created the materials in a car's chassis, body, windshield and seats.
10:25But key components like the copper for the car's electronics are yet to be manufactured.
10:31To create this crucial metal, a new generation of stars must die an even stranger death.
10:40Star Wars
10:52Picture the scene 13 billion years ago,
10:56as the universe's very first stars are coming to the end of their lives.
11:03The sky is filled with flashes.
11:07A star after star violently explodes.
11:11These supernovas hurl a rich cocktail of elements into space.
11:16Carbon, silicon, aluminium and iron.
11:20Materials that will one day be used to build cars on Earth.
11:26But some even heavier elements needed to build a car are still missing.
11:31Elements like copper and gold, used in the car's wiring.
11:36So far the universe hasn't created these heavy metals, but it's about to.
11:42In the case of copper, the secret to its formation is reincarnation.
11:48Copper is one metal that your car can't live without.
11:52Copper is one metal that your car can't live without.
11:56Turns out there's over a mile of copper in the average car.
11:59And the reason why is because copper is an excellent electrical conductor.
12:07Copper is also used to conduct heat in radiators.
12:14It stops bearings from failing when you need to go fast.
12:18And when you need to stop, copper provides the friction in your brake pads.
12:24But the story of how that copper came to exist and be on Earth, that's a truly remarkable story.
12:33Copper can't begin to form until the first generation of stars have died.
12:41The expanding supernova remnants crash into neighbouring clouds of gas.
12:46Creating a shockwave of pressure.
12:49The perfect nursery for a new generation of stars.
12:59There are cycles to the universe.
13:01Stars form, they live out their lives, they die, they blow off winds and they explode.
13:06Seeding their material into gas clouds, which then form new stars with heavier elements in them.
13:12Which will repeat the cycle again.
13:16So if you want to think about it that way, the universe is the ultimate recycler.
13:23The gas that forms these second generation stars is peppered with the carbon, aluminium and iron thrown out by the supernova.
13:32The biggest of these new stars burn extremely brightly.
13:36But only for a few million years.
13:39Then they undergo an incredible metamorphosis.
13:47The star rapidly expands to a hundred times its previous size.
13:54Then it cools and turns a ghostly red.
13:59The second generation star has transformed into a red supergiant.
14:05And in its diffuse outer layers, iron is slowly converted into copper.
14:13But not by fusion.
14:16That iron nucleus has 26 protons.
14:19That's a serious electric charge.
14:21So it's going to repel any protons we try to shoot in there.
14:27How do we get more protons in?
14:30The way we get those protons in there is we trick the nucleus.
14:34Instead of shooting in protons, we shoot in neutrons.
14:39Colliding atoms in the outer layers of a star sometimes spit out neutrons.
14:46Neutrons don't have a charge.
14:48So they're not repelled by the positively charged protons in the iron stardust.
14:54These neutrons are able to stick to the iron atoms around them.
15:01An atom is a very tiny thing and makes a very small target.
15:04But there's a lot of particles flying around near a star.
15:07And if, by chance, a neutron can hit an atom, it can stick.
15:11And that will actually make the nucleus of the atom larger.
15:16Neutron by neutron can hit an atom.
15:19And then that neutron can actually decay into a proton.
15:23The neutron spontaneously splits into an electron which is ejected
15:27and a proton which is left behind.
15:30The process transforms iron into copper.
15:34Scientists call this magical conversion beta decay.
15:38So you can build up heavy elements very slowly
15:41over the course of thousands or millions of years just by capturing neutrons.
15:50Eventually, the core of the red supergiant runs out of fuel.
15:54And the star explodes.
15:56Blasting its copper-rich outer layer into space.
16:02Thanks to the life and death of two generations of stars,
16:07we can equip our car with copper wiring.
16:12But we're still short of some even heavier metals,
16:15such as lead for the battery and gold for the electrical connectors.
16:19To make these truly massive atoms,
16:22the universe must create the most spectacular explosions since the Big Bang.
16:35To make a car, you need some seriously heavy metal.
16:40Metal like iridium.
16:42Metal like iridium.
16:44A super-sized atom with 77 protons
16:47that's used to coat the tips of spark plugs.
16:53Heavier still is gold with 79 protons.
16:58This shiny conductor resists corrosion,
17:01making it ideal for exposed electrical connections.
17:06These super-massive atoms are the most powerful
17:10These connectors here for this airbag assembly are gold.
17:14And so this thing can react really quickly if there's an accident and save your life.
17:23The heaviest atom found in a car is lead with 82 protons.
17:30Only lead can deliver the short burst of high power
17:33needed to start an engine over and over again.
17:40But until very recently,
17:43how the universe made these oversized atoms was a complete mystery.
17:49You can't make gold atoms in a normal star.
17:53You can't make gold atoms in a massive star that's dying.
17:58In order to make atoms this big, with this many neutrons,
18:01you need a truly cataclysmic event.
18:04Just a few years ago, most scientists believed
18:07that supernovas were cataclysmic enough to do the job.
18:14But astronomer Ido Berger had doubts.
18:18If you open any one of these books
18:20and flip to the page that tells you where gold came from,
18:23it will tell you that gold came from supernova explosions.
18:26And if you flip to the page that tells you where gold came from,
18:29it will tell you that gold came from supernova explosions.
18:32But nobody had directly observed
18:34supernovas producing elements like gold.
18:38And inside computer simulations,
18:40virtual supernovas lacked the energy to forge these oversized atoms.
18:45Clearly, something was wrong.
18:47But if supernovas weren't powerful enough,
18:50what in the universe was?
18:52To form heavy elements requires a lot of neutrons.
18:55And so another possible theory was that the heaviest atom
18:59And so another possible theory was that the heaviest element
19:02were produced in the mergers of two neutron stars in a binary system.
19:10Neutron stars are some of the strangest objects in the universe.
19:14They're formed from the collapsed cores of giant stars.
19:19You're taking a couple of times the mass of the sun
19:22and squeezing it down into a ball that's only a few miles across.
19:26The electrons and the protons that are flitting around inside of that
19:29combine to form neutrons.
19:31And what you're left with is an extremely dense ball of neutrons,
19:36about the size of a city.
19:41Neutron stars are extremely dense.
19:44If you take just a teaspoon of the neutron star material,
19:47it's actually a billion tons.
19:50If neighboring stars die together,
19:53it's possible for the two neutron stars they leave behind
19:56to form a spinning binary pair.
20:00But the partnership is doomed.
20:03What you're left over with is two incredibly compact,
20:06dramatic objects spiraling around each other.
20:11Over time, they move in together
20:14until finally they can coalesce
20:17in the most violent explosion since the Big Bang.
20:24The explosion is called a neutron star merger.
20:29The amount of energy in this explosion is crushing.
20:33There's almost no way to describe it.
20:35It's like taking all of the sun's energy that it will ever emit
20:38over its entire lifetime and releasing it in a single second.
20:47Berger suspected that this colossal explosion
20:50forged iridium, gold and lead.
20:53But to rewrite the textbooks, he needed hard evidence.
20:58It was difficult to convince the community
21:01that this was a potential channel for the production of heavy elements.
21:09The proof is to actually see this process happening in the universe.
21:16June 2013.
21:18NASA's Swift satellite spotted a short burst of gamma rays
21:22from a nearby galaxy.
21:25A sign that a neutron star merger had just taken place.
21:29For Berger, it was the lucky break he'd been waiting for.
21:35As soon as we knew that there was a gamma ray burst nearby,
21:39we knew that this was our one chance for perhaps several years
21:43to obtain the right kind of measurements
21:46to test the formation of heavy elements.
21:50Once Swift had identified the burst,
21:53the Hubble Space Telescope swung into action to capture images.
22:00We grabbed them right away and we just looked.
22:03We knew exactly where to look, at the centre of this red circle.
22:06And what we saw was this source right there in the middle
22:09that is the direct signature of the production of very heavy elements,
22:14including gold.
22:19Berger's theory was right,
22:21but the rate of production was far higher than he'd expected.
22:26In that one event, the amount of gold that was produced
22:29was more than the mass of the Earth.
22:33If we can bring it all here,
22:35it would be worth quadrillions and quadrillions of dollars.
22:39The theory is still very new,
22:42but it's possible that ancient neutron star mergers
22:46made all the heavy metals we see in the world today,
22:51including the last remaining ingredients for our car.
23:02But all these elements were floating free in space.
23:07They still have to be pulled together
23:09into one giant fabrication plant.
23:16The Earth.
23:34Before the Earth was born,
23:36the materials that would one day go into making your car
23:39looked like this,
23:41a vast, swirling cloud of gas and stardust,
23:45the exploded remnants of ancient stars.
23:48The clouds between the stars of the galaxy
23:50are made of everything that the Earth,
23:52your body and your car is made of.
23:54There's everything that you need floating
23:56in gaseous form between the stars.
24:00Four and a half billion years ago,
24:02this interstellar gas collapsed once more.
24:06It was time to create a rather ordinary mid-sized star,
24:11our Sun.
24:13Close to the young Sun,
24:15all of the lighter stuff got blown away.
24:17What was left behind was the heavier, denser stuff.
24:23There was carbon, there was iron,
24:25there was gold, everything in between.
24:29Over time, these free-floating elements began to coalesce.
24:34Dust became rock.
24:39Rocks joined to form larger objects called planetesimals.
24:44Finally, planetesimals joined to form the Earth.
24:52Our planet was born with all the ingredients needed to build a car.
24:57But these ingredients were about to go their separate ways.
25:03The Earth is a big planet,
25:05and it's done something that not all planets do.
25:07It's differentiated, it's melted.
25:11Copper and lead dissolved in sulphur
25:14and floated to the top of the molten Earth,
25:17making these metals easy to mine today.
25:22But precious metals like iridium and gold
25:25sunk to the Earth's core,
25:27and most of the iron sunk with them.
25:30It's kind of a pain, actually.
25:32All the heavy elements that are super useful, like iron,
25:34they've sunk to the middle of the Earth where we can't reach them,
25:37and there's not a whole lot of it in the crust.
25:443.8 billion years ago, the oceans formed,
25:47and water dissolved the last remaining traces of iron
25:50from the Earth's surface.
25:55In fact, there was so much iron in the sea
25:57that the Earth would have been green,
25:59not blue like it is today.
26:02The Earth's crust seemed destined to be practically iron-free.
26:07Then along came the most unlikely saviour.
26:11Green slime.
26:15I want to show you a couple of examples
26:17of rocks that we recently brought back from South Africa.
26:21Caltech geobiologist Woody Fisher
26:23traced the history of iron through the Earth's earliest rocks.
26:28This is an example of a rock that was deposited on the sea floor
26:31a little over 2.5 billion years ago,
26:33and there's not a lot of iron in this sample.
26:36Now, what's so interesting is you go to the same place on the Earth
26:40200 million years later,
26:42and what you find is that things have really changed,
26:45and you'll note this very rusty colour to it.
26:48This is from the presence of iron oxides,
26:50and, in fact, the rock itself is incredibly heavy, very dense.
26:56Why did the Earth's geological record change so quickly and so profoundly?
27:02One clue is that the sudden appearance of iron-rich rocks
27:06coincides with the rise of the first simple plants.
27:12This is a microorganism called a cyanobacterium.
27:16Each of the individual cells that are present in that medium
27:19are green, and they're conducting photosynthesis.
27:22This group, cyanobacteria, is gathering energy from light,
27:27using that to split water,
27:29and in so doing, they produce copious amounts of oxygen.
27:36In the early oceans,
27:38this newly formed oxygen reacted with the dissolved iron,
27:42forming a heavy rust that settled on the ocean floor.
27:47For the first time in Earth's history,
27:49there was oxygen, free oxygen, in the air.
27:52That combined with the iron,
27:54and the iron basically sank to the bottom of the ocean.
27:58These ancient rusty deposits
28:01formed the iron ore that we mine today.
28:08So in the process of making a car, mining the iron ore,
28:12life was an essential part of that first step.
28:16You have to wait until after these guys evolve
28:19in order to be able to concentrate the raw materials that you need.
28:32The life of early plants brought us iron,
28:35but their death was perhaps even more helpful,
28:39because without dead plants, most cars wouldn't run.
28:46So what's the final ingredient for getting a car to actually go?
28:50You need to add fuel,
28:52and we right now use hydrocarbon-based fuel.
28:55We use oil.
28:58Oil is actually the remnant of dead plant life
29:01from billions of years ago.
29:04It amazes me to think that as you're driving your car around,
29:07what you're actually running the car on is ancient dead life.
29:12These hydrocarbons are also processed to help make rubber and plastics
29:16for the tyres and interior trim.
29:26Now we have almost all the components needed to complete a car.
29:31All that remains is a spark to bring the engine to life.
29:37But to get that spark,
29:39the Earth must pay a catastrophic price.
29:4565 million years ago,
29:47the Earth's crust is missing one crucial group of super-tough metals.
29:57This is a spark plug,
29:59and the way it works is that 100,000 volts are put across this gap here,
30:05and that ignites gasoline vapour in the cylinder of your motor.
30:11This tip has to survive in very harsh conditions.
30:16So it must be made of a very, very sturdy, robust material,
30:20and the material in this spark plug is a metal known as iridium.
30:27Like gold and lead,
30:29iridium was created inside the biggest bang since the Big Bang.
30:34A neutron star merger.
30:38Although the Earth originally contained a large amount of iridium,
30:42it sank out of reach while the Earth was still molten,
30:46falling to the core under the influence of gravity.
30:52The iridium that we mine on the Earth's surface today
30:55came from somewhere else.
30:59This exposed rock face in Colorado reveals a clue.
31:03A mysterious layer in the Earth's geological record
31:06that wraps around the entire planet.
31:09There's something particularly interesting about this clay layer here.
31:13If you analyze the concentration of rare metals like iridium in this layer,
31:17you'll find that there's about 100 times as much iridium here
31:20as in the other rocks around us in the crust of the Earth.
31:23It's rather bizarre, actually, to find so much iridium
31:26concentrated in one place here in crustal rocks.
31:29And it turns out that the entire budget of the iridium in the Earth's crust
31:33is pretty much contained in this layer.
31:37When geologists discovered the iridium layer in the late 70s,
31:41it became one of the biggest mysteries in science.
31:45How could so much of this rare metal end up concentrated
31:49in such a thin layer?
31:53Astronomers had measured similar concentrations of iridium before,
31:57inside rocks that had come from the asteroid belt.
32:02Billions of years ago, planets were forming all over our solar system,
32:06but there was an area in between Mars and Jupiter
32:09where the gravity of Jupiter pretty much pulled apart anything that tried to form.
32:13And what got left over were a bunch of large rocky chunks
32:16that we call the asteroid belt.
32:19Now, some of the asteroid belt is made of rock.
32:22Other asteroids are richer in metals.
32:28From time to time, asteroids are thrown out of orbit by another asteroid,
32:33or by the long reach of Jupiter's gravity.
32:37Sometimes, these asteroids smash into the Earth.
32:44Could the iridium layer be the scattered remains of a single asteroid?
32:49Or a single, giant, metal-rich asteroid impact?
32:5930 years ago, this idea sounded far-fetched.
33:03Only an asteroid the size of a city would have had enough power
33:07to blast debris around the entire planet.
33:11If you can imagine the magnitude, the enormity of the violence of an event like that,
33:15to have inches of dusty debris come booming over the horizon
33:19and settling out of the sky and raining on top of you and burying you in this layer,
33:23that should make a pretty big crater someplace on the Earth.
33:29Although it sounded incredible,
33:31the asteroid hypothesis also solved a long-standing mystery.
33:37The dinosaurs were wiped out around the same time the iridium layer was laid down.
33:42Could the two events be linked?
33:46The puzzle was solved when an asteroid impact crater was discovered down in the Yucatan.
33:51The crater age turned out to be exactly 65 million years old,
33:55the same age as this deposit,
33:57and the crater size turned out to be just the size of crater you would get
34:02from the size of an asteroid it would take to make this layer.
34:07So it turns out that in a lot of ways you can think of asteroids
34:10as sort of a cosmic iridium delivery system for us here on the surface of the Earth.
34:14And it's not just iridium we have to thank asteroids for.
34:18There were probably several times in the history of our solar system
34:21where there was heavy bombardment,
34:23all kinds of asteroids and comets falling in toward the Earth.
34:26Well, the Earth had solidified to some degree by that time,
34:29so not everything sank down into the core.
34:31So some of the metals we find around us are products of this later era of bombardment.
34:40Asteroid's history is a violent one.
34:42Over the course of time we've been hit over and over and over again by asteroids of all sizes.
34:47Some of them have actually delivered quite a bit of heavy elements to the surface of the Earth.
34:55These asteroid-borne materials include most of the gold, platinum and nickel we use in cars today.
35:03Asteroid impacts will form little pockets of concentrations
35:08of some of those ore minerals and ore metals for us
35:11that we can then mine in greater abundance on the surface.
35:14In many cases when you go to a mine to dig up these heavy elements,
35:18what you are doing is tapping into an asteroid impact.
35:26But these mines are relatively rare.
35:29As humanity continues to grow, our precious metals will be the first metals to run out.
35:36If we want to get more, the only option will be to mine the asteroid belt itself.
35:43I don't think we can keep making cars here on the surface of the Earth forever.
35:47As population grows and our need for these minerals grows,
35:51at some point you are going to mine the Earth as much as it can be mined.
35:56And you have to start to look someplace else.
35:59And fortunately, there are mines in the sky out there by the billions, and they're called asteroids.
36:05A lot of asteroids have platinum, iron, nickel, gold in them.
36:09It's very expensive to go up there and grab them and tow them back.
36:13But just the raw materials in an asteroid could be worth hundreds of billions of dollars.
36:20NASA recently estimated the value of the precious metals and materials on the asteroid belt
36:25as being about 600 quintillion dollars,
36:28or about 100 billion dollars for every person alive on the Earth today.
36:32I do not expect to be seeing any of that money myself.
36:36We'll have to wait for rocket technology to get cheaper
36:39before asteroid mining becomes a viable proposition.
36:43Until then, we'll continue to rely on the asteroids that have hit the Earth.
36:51Metal-rich asteroids are the final piece of the puzzle.
36:56We can now reconstruct the journey of every atom of our car through time and space.
37:02From the moment of the Big Bang,
37:05through generations of stars,
37:07to the birth of the Earth,
37:09and eventually, the showroom floor.
37:13Over the course of the multiple supernovae in our universe,
37:17and the birth and death of stars,
37:19we were able to collect all of the materials needed to assemble these cars.
37:25That's pretty fantastic.
37:30I think we don't fully appreciate how complicated the elements that make up our car really are,
37:35and how special they are.
37:36They really are star stuff.
37:48But not every car is like the one we've just pulled apart.
37:53These days, not every car runs on petrol.
37:58Electric vehicles require a magical element
38:01that's made in space by cosmic ray guns.
38:18This car doesn't have a petrol tank.
38:21It's part of a new generation of electric vehicles.
38:26The key to these high-tech cars is their rechargeable batteries.
38:34A technology that relies on one of the Earth's rarest metals.
38:40This here is a battery pack from an electric car.
38:43And in today's electric cars, the metal of choice is lithium.
38:47And lithium has one of the most amazing stories in the universe.
38:54After hydrogen and helium, lithium is the lightest element,
38:58with just three protons and four neutrons.
39:02Its lightness makes it ideal for electric cars.
39:07If the battery weighs more than the car,
39:09then we are just wasting energy on moving the battery around.
39:12If we can build a light battery, for example a lithium-ion battery,
39:16then we can provide the power without the penalty
39:20of having to carry those heavy batteries along with the car.
39:25Lithium is rapidly becoming one of the most sought-after metals on Earth.
39:30But it's also a cosmic curiosity.
39:35The Big Bang creates a trace of lithium.
39:38But as the first stars form, this lithium disappears.
39:43Unlike hydrogen and helium, which are fairly stable on an atomic scale,
39:47lithium is a little bit fragile.
39:49It can actually be broken apart into its components.
39:54As time goes by, these first stars manufacture a little lithium on their own.
39:59But it doesn't last long.
40:02It is so fragile that the instant it's made,
40:05it's destroyed once again by the conditions in the core of the star.
40:09The lithium we have on Earth isn't made in a star like iron, copper and iridium.
40:15Instead of fusing lighter elements together,
40:18lithium is created when larger atoms are blasted apart.
40:23The answer for where lithium comes from is an amazing thing.
40:26It's almost like a sci-fi answer.
40:28It kind of comes from ray guns from space.
40:39The ray guns are supernovas, and their bullets are cosmic rays,
40:45high-velocity particles that streak through space at close to the speed of light.
40:51Cosmic rays are subatomic particles.
40:53They are atomic nuclei that are accelerated to high speed in a supernova explosion.
41:00If another atomic nucleus gets in the way, it can hit them and shatter them.
41:04And one of the pieces of shrapnel from this explosion is lithium.
41:10LITHIUM
41:18The process is a bit like going bowling, where the bowling ball is the cosmic ray,
41:22and the pins together are some other atomic nucleus.
41:33When the bowling ball smashes into the pins,
41:36it sends them scattered in all directions.
41:40LITHIUM
41:42And one of those pins could be lithium.
41:57Cosmic rays are traveling throughout all of space, between galaxies and in galaxies.
42:01So the cosmic rays that are forming lithium by breaking other elements apart
42:05are literally doing it in the space between the stars.
42:10Almost all the lithium on Earth today was made this way,
42:14atom by atom in the vastness of space,
42:18and then swept up into the clouds of gas that formed our solar system.
42:31For our cosmic car, this may look like the end of the line,
42:35but the production line for the universe keeps on rolling.
42:41This is pretty awesome.
42:42These atoms in this car here have been traveling across the cosmos.
42:46They came to us from maybe 13 billion years ago,
42:49a billion years after the formation of the universe.
42:52Now guess what?
42:53They were used and we're returning them back to where they came from.
42:57The atoms in our car will not be in our car forever.
43:00In fact, our car will probably be destroyed within a single human lifetime.
43:04Time to crush.
43:05It'll be recycled into other things on Earth,
43:08but eventually, even the atoms on Earth will be recycled with the rest of the cosmos.
43:17How cool was that?
43:20You can imagine my car gets destroyed with the Earth
43:24and eventually makes its way to another planet.
43:27It gets built into some other kind of transportation mode by an alien race.
43:32I mean, that's totally possible.
43:34I think that's kind of a cool idea.
43:39From stars being born billions of years ago to cosmic rays to even the Big Bang itself,
43:45it's amazing to contemplate all of the things that had to come together in the universe for us to have cars.
43:51You really are driving around in the end product of something that started 13.7 billion years ago.
43:58That new car smell, that's actually old universe smell
44:02because that smell is traceable all the way back to the Big Bang.
44:08How do you like that?
44:11That guarantees the last word in the show.