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00:00Why are we here?
00:13Where do we come from?
00:16These are the most enduring of questions.
00:19And it's part of human nature to want to find the answers.
00:24We can trace our ancestry back hundreds of thousands of years
00:32to the dawn of humankind.
00:35But our story extends far further back in time.
00:40Our story starts with the beginning of the universe.
00:4913.7 billion years old.
00:54Filled with countless stars and galaxies.
01:00It's a universe of unimaginable wonders.
01:05Yet each is connected to us.
01:09Ultimately, we are part of the universe.
01:13So its story is our story.
01:16This film is about the stuff that makes us, and where it all comes from.
01:26Because understanding our own origins means understanding the lives of stars.
01:32And how their catastrophic deaths bring new life to the universe.
01:42Because every piece of your body was made in the first few minutes of the life of the universe.
01:47the universe.
01:53Transformed in the hearts of stars.
02:00And forged in the violent furnaces of space.
02:03The universe is the most important part of our universe.
02:04And how will it be?
02:05Because it fares in the universe.
02:06It's all the same.
02:07We are now gleaning.
02:38This is the Pashupatanath Temple in Kathmandu, Nepal.
02:42It's one of the holiest shrines in the Hindu faith.
02:49All the Hindus of the Indian subcontinent make it a point to travel to this place once in their life.
02:57This is the holiest of the holy places.
03:02Pilgrims travel here to pay their respects to the Supreme Lord Shiva the Destroyer.
03:08But for many of them, the most important time to come here is at the end of their lives, to die and be cremated.
03:21Hindus believe in reincarnation, a cycle of birth and death, until the soul can be released.
03:28But it's not just their souls that Hindus believe are reincarnated, but also the very material that makes up their bodies.
03:42The Hindus believe that a human being is made of five elements.
03:48Chiti, earth.
03:50Apa, water.
03:52Teja, the energy.
03:53Maruta, air.
03:55And Bhuma, the ether.
03:56Five elements.
03:58Any individual, any human being is made of these five elements.
04:01At death, all the five constituent elements of the body go back to the universe.
04:18By being cremated, these five elements that make up their bodies are returned to the universe to be reused and recycled.
04:27Hindus believe it is only in this process of destruction that the new can be created.
04:37You should not be too much worried and concerned on death.
04:53It is the change of your clothes, for example.
04:59This ancient belief touches on a deeper truth about how the universe works.
05:07Every atom in our bodies is the result of cosmic recycling, which began not here on Earth, but in the depths of space, through the epic life cycle of the stars.
05:18To understand that story, we will journey to the stars in all their stages of life.
05:37This is where stars are born, a nebula, a stellar nursery where new stars burst into life.
05:48Those stars will burn for billions of years until their voracious hunger for fuel forces them to blow up, to become giants.
06:04Hundreds of times bigger than our sun, and when they die, stars go out with the biggest bang in the universe.
06:19These are our cosmic origins, that make each and every one of us stardust.
06:26These are our cosmic origins that make each and every one of us stardust.
06:30The first step in understanding how this stardust becomes us is to understand that everything is a cosmic cycle of life and death.
07:01Something that is evident here on Earth.
07:07These are the Himalayas. They're the highest mountains in the world, but oddly enough, also some of the youngest.
07:13If you'd come here around the time the dinosaurs existed, everything would have just been ocean.
07:18The Himalayas haven't always been mountains. We can find clues to their true origin by looking at them more closely.
07:33This is limestone. It's the rock that makes up the rocks around us and large parts of the Himalayas.
07:40It's a sedimentary rock, which means it was formed at the bottom of the ocean from the bodies of living creatures,
07:47which as they died fell to the bottom of the ocean and eventually compacted and formed rock.
07:52Over millions of years, the sea floor was raised up to become these vast peaks.
08:05Fossils of sea creatures have even been found on the summit of Mount Everest.
08:18It's a clear example of the endless cycle of the Earth's resources that has been going on since the dawn of time and is still going on today.
08:32The rocks and the mountains around us used to be living organisms.
08:38They're made of the same materials that we are, and we're made of the same materials that they are.
08:44Nothing new is made. Everything is recycled through life and through rocks and back through life again.
08:50It's an example of the Earth's recycling process of all material.
08:54And the reason that the rocks of the Earth can become living things, and that living things can go back to become part of the rocks of the Earth,
09:07is because everything is made of the same ingredients.
09:15These ingredients are atoms, a basic unit of matter.
09:20On Earth, we find 92 different varieties of atom, and each different variety is a different element.
09:31Every rock, every cloud, and every living thing is made up of combinations of these elements,
09:39which gives rise to the rich variety of the Earth.
09:43We rarely see the elements on their own, but when we do, they have very individual and often surprising characteristics.
09:54Calcium in its raw form is actually a shiny silver metal.
09:58We're not used to seeing it in this form.
10:01We're always just seeing it in combination with other elements, such as in chalk or in our bones and teeth.
10:05This is sodium, which is also a shiny silver metal, but in the atmosphere combines oxygen very rapidly to form this whitish skin.
10:15But if I cut it up, you can see that the surface is in fact very shiny, although it goes white very quickly.
10:22In this form, sodium reacts extremely strongly with water.
10:29Here it's so volatile, it's combining with the hydrogen and the oxygen in the water in an incredibly reactive way.
10:46And it's this reactivity that enables elements to combine to produce new substances.
11:02That, in turn, has allowed the Earth to develop its infinite variety.
11:07The chemistry set we have on Earth extends far beyond our planet.
11:22We have set foot on the Moon and know that it is rich in helium, silver and water.
11:29We have sent robot landers to our neighbouring planets.
11:32And discovered that on Mars, iron is abundant, which is combined with oxygen to form its familiar rusty red colour.
11:45And we know that Venus's thick atmosphere is full of sulphur.
11:51We've sent spacecraft right to the edge of the solar system to discover that Neptune is rich in organic molecules like methane.
12:02But where we have been able to visit the other planets to discover what they are made of,
12:07the stars are much further away.
12:11Separated from us by the vast distances of space.
12:19Even our nearest star, Proxima Centauri, is 10,000 times more distant than Neptune.
12:264.2 light years from Earth.
12:29And the nearest galaxy, Andromeda, is 2 and a half million light years away.
12:41The only contact we have with the stars is the weak light that has crossed the Universe to reach us.
12:48And yet, amazingly, we can use that light to tell exactly what all these distant worlds are made of.
12:54It's all down to a particular property of the elements.
12:59That is, when you burn them, they give off light.
13:03And each element gives off its own unique set of colours.
13:06This is strontium.
13:07As you can see, it burns bright red.
13:17This one is barium.
13:22And it burns green.
13:24And this is copper.
13:27And it burns blue-green.
13:28And even when there are many chemicals together, we can still detect them.
13:38By looking deeper into the light, we can break it down into its parts.
13:42If you shine light through this diffraction film, it acts like a prism and splits the light into its entire spectrum of colour.
13:53And we can do exactly the same with the light of the stars.
13:57This is the full spectrum of light from our nearest star, the Sun.
14:05The first thing you can see is it looks exactly like a rainbow.
14:08And that's because a rainbow does exactly the same thing and splits light into its constituent colours.
14:13But when you look closer, you can see there are lots of dark lines.
14:16And each of these lines corresponds to the colour emitted by elements when they burn.
14:25For example, these lines represent iron.
14:28These three represent magnesium.
14:31Down here is sodium.
14:33And this is one of the lines of hydrogen.
14:34So by looking at these lines in precise detail, you can work out exactly what elements are present in the Sun.
14:50And it turns out that's about 70% hydrogen, 28% helium and only 2% anything else.
14:59And you can do this for any of the stars you can see in the sky.
15:05You can measure exactly what they are made of.
15:12Polaris, the pole star, is 430 light years away.
15:17But we know just by looking at its light that it has about the same heavy metal abundance as our Sun.
15:24But it's got markedly less carbon and a lot more nitrogen.
15:36Vega, the second brightest star in the northern sky, has a very strange elemental abundance.
15:43It has only about a third of the metal content of our Sun.
15:47Whereas other stars are metal heavy, Sirius, the dog star, has an iron content three times higher than the Sun.
15:59And Proxima Centauri has comparatively large amounts of magnesium.
16:04But although the quantities of the elements may vary, wherever we look across all of space, we only ever find the same set of 92 elements we find here on Earth.
16:18And that amazingly means that the entire Earth, me, the plants around me, are made from exactly the same constituents as the entire Universe.
16:28So we are connected to the Universe because we are all made of the same stuff as stars and galaxies.
16:35But where did all this matter originate? How was it created? And how did it become us?
16:47To understand the answers to those questions, we have to go back to the beginning of time itself.
16:53The primordial Universe was very different to how it is today.
17:07There were no stars or planets.
17:13It was a soup of basic particles called protons.
17:16Yet these simple particles are the basis of all matter.
17:25So within the first moments of time, some 13.7 billion years ago,
17:32the building blocks of the entire Universe were created.
17:36From just protons, all of the elements were made.
17:55And understanding how that happened has an underlying simplicity that is child's play to understand.
18:02The only difference between the different elements is the number of protons.
18:09You can see most of that is just one proton.
18:13That would represent hydrogen, the most abundant element in the Universe.
18:22One proton at the heart of an atom makes hydrogen, the basis of every other type of atom.
18:28And when you put two protons together, something else happens.
18:34One of them gets converted into a neutron, another of the fundamental building blocks of the Universe.
18:41Simply by sticking increasing amounts of protons and neutrons together,
18:47through a process called nuclear fusion,
18:50it is possible to create all the elements in the Universe.
18:53That would represent helium.
18:56Two protons and two neutrons.
18:58Let's see if we can get bigger ones.
19:02There's one with 12. That would be carbon.
19:03And you can just stick the protons together again and again and again,
19:06to get heavier and heavier elements,
19:08until we have all the elements we have on the Earth today.
19:09So by fusing just hydrogen atoms together, you can build everything in the Universe.
19:15So by fusing just hydrogen atoms together, you can build everything in the Universe.
19:18So by fusing just hydrogen atoms together, you can build everything in the Universe.
19:19It may seem like a gentle
19:24but it may seem like a gentle light, but it's a gentle light,
19:26but it's a gentle light, but it's a gentle light.
19:28So by fusing just hydrogen atoms together, you can build everything in the Universe.
19:33It may seem like a gentle idea, but in reality, when two protons fuse, it is extremely violent.
19:57Here on Earth, one of the few places where conditions are intense enough to fuse protons,
20:02is within the heart of a nuclear device.
20:08As the device fuses hydrogen into the next heaviest element, helium,
20:13it also releases an enormous amount of energy.
20:19You can release that energy very quickly, very quickly.
20:23Most of the energy is gone in a nuclear device in less than half of a microsecond.
20:27Achieving fusion was one of the greatest human accomplishments.
20:34It took until the middle of the 20th century to master,
20:38because it is incredibly difficult to get protons to stick together.
20:42Atomic nuclei are difficult to fuse because they are both positively charged.
20:48When you try to push them together, the natural laws of physics cause them to repel.
20:53So you need a lot of force to push them together enough to touch.
20:56It takes a temperature of at least 4 million degrees Celsius to even start it.
21:08Releasing the potent power of fusion seems like the ultimate technological achievement.
21:13But actually, it's the most natural thing in the world.
21:18Because it's happening all the time.
21:21Just a few million kilometers above our heads.
21:24It's the same process that powers the stars.
21:42The energy released by fusion makes the stars shine.
21:45And as it flows outwards, it fills the solar system with the heat and light that breathes life into our planet.
21:54It's this process of turning one element into another that allows us to exist.
22:01But for all its power, the sun only converts hydrogen, the simplest element, into helium, the next simplest.
22:13And there are over 90 other elements.
22:18They are the elements that build the fabric of our world and that also make us.
22:23So where did they all come from?
22:39Looking out into space, you'd think it was a constant, unchanging place.
22:45That the stars would always be there.
22:47But in fact, the stars are only a temporary feature in the sky.
22:53And though they may burn brightly for millions or even billions of years,
22:58they can only survive for as long as they have a supply of hydrogen in their core to burn.
23:07When a star runs out of this hydrogen, it begins to die.
23:11But it doesn't go quietly.
23:13The star becomes much hotter until, with a flash, it starts to expand.
23:29Over tens of thousands of years, it balloons to many hundreds of times its previous size.
23:38In this bloated state, the star is unable to maintain its surface temperature.
23:44As it cools, it takes on the characteristic colour of a dying star.
23:52And is now a red giant.
23:54Well, these are pictures of a red giant star in our galaxy, a star called Betelgeuse.
24:07And it's one of our nearest neighbours in cosmic terms. I mean, it's only about 600 light years away.
24:18But it truly is a giant in every sense of the word. I mean, it's about 20 times the mass of our sun.
24:23But it's the size, I think, that's really astonishing.
24:27And if you sat the sun there, in the centre of Betelgeuse, you could fit Venus, the Earth and Mars, and actually everything in the solar system, all the way out to Jupiter, actually inside the star.
24:39And because Betelgeuse is so big, we can see surface features on the star.
24:45So these are, well, they're sunspots on the surface of a star 600 light years away.
24:52But what's important for making the other elements is not what's happening on the surface, but what's happening beneath, in the core of the star.
25:01Well, if you imagine this old prison in Rio as a dying star like Betelgeuse, then out there would be the surface shining brightly off into space.
25:29And as you move down into the heart of the prison, deeper and deeper, the conditions become hotter, hotter, denser and denser.
25:39And so right in the centre, you get to the core. And it's down there, in the core, that all the ingredients of life are made.
25:48Deep in its core, the star is fighting a constant battle against its own gravity.
26:04As it desperately tries to stop itself collapsing under its own weight, new elements are made in a sequence of separate stages.
26:18Stage one is after all the hydrogen has fused to helium in the core.
26:23And at that point, there's no more fusion and there's no more pressure.
26:33And very quickly, the star, the core will start to collapse, leaving, well, a shell of hydrogen and helium behind.
26:43Beneath this shell, as the core collapses, its temperature rises again.
27:01Until at 100 million degrees, stage two starts and helium nuclei start to fuse together.
27:08The fusion of helium in the core releases more energy, and that halts the collapse.
27:15But it also produces two elements that are vital for life.
27:23Carbon and oxygen.
27:26Now, compared to the lifetime of a star, the creation process of carbon and oxygen is over in the blink of an eye.
27:42Because in only about a million years, the supply of helium in the core runs out.
27:47And then for stars as massive as the sun, the fusion process stops because there just isn't enough gravitational energy to squash the core anymore and re-initiate fusion.
28:02But for stars the size of Betelgeuse, the fusion process can continue.
28:06When the helium runs out, gravity takes over again, and the collapse continues, leaving a layer of carbon and oxygen.
28:19And the temperature rises once more, launching stage three, in which carbon fuses into magnesium, neon, sodium and aluminium.
28:29And so it goes on, core collapse, followed by the next stage of fusion to create more elements.
28:39Each stage is hotter and shorter than the last.
28:42And eventually, in a final stage that lasts only a couple of days, the heart of the star is transformed into almost pure iron.
28:59His chemical symbol is Fe.
29:03This is where the fusion process stops.
29:06The core is now a solid ball of those elements, stacked on top of each other in layers.
29:16On the outside, there's a shell of hydrogen.
29:19Beneath it, a layer of helium.
29:22Then carbon and oxygen, and the other elements that the star has made in its lifetime, all the way down to the very heart of the star.
29:31And once that has fused into solid iron, the star can no longer release energy through fusion reactions.
29:42Then there's only one thing that can happen.
29:50It will collapse under the force of its own gravity.
29:54And in about the same amount of time it takes this prison block to crumble, the entire star will fall in on itself.
30:17This is the destiny that awaits the vast majority of the trillions of stars that populate our universe.
30:33Yet the implosion of a star only forges the first 26 elements.
30:38What are the remaining elements, some of which are vital for life and many of which we hold precious?
30:47These are the remote forests of Northern California.
30:54A hundred years ago, this whole area was teeming with people, all desperately in search of one element.
31:04This is the home of the California Gold Rush.
31:07Great historians have written about it as to have been the largest peacetime migration that the world had ever experienced.
31:22And some made it and some didn't. Some lived and some died. All for gold.
31:28All for gold.
31:37Mike Miller is still looking for that elusive element.
31:43He owns the original 16 to 1 mine.
31:49One of the few gold mines still operating in California.
31:52The miners working today still use the age-old process of blowing out the rock with explosives so that they can sift through the massive amounts of debris to search for tiny traces of gold.
32:08Fire in the hole! Fire in the hole!
32:11Fire in the hole!
32:23But it's a hit-and-miss process.
32:28As many, many of the days that we work in it, we get no gold. In fact, most of the time we never recover any gold.
32:33But when it comes in, it comes in really strongly.
32:37I think the biggest single shift that we had at the 16 to 1 was a dozen years ago when we mined the equivalent of a million dollars of gold in one day.
32:52This piece of gold was mined here and it came out exactly looking like this.
32:56What's nice about it, too, is every now and then we get a chance to have something in our hand that's 144 million years old.
33:10Not everybody gets a chance to do that.
33:17On Earth, gold is in extremely short supply.
33:20And it is that rarity that makes gold valuable.
33:28In California, most of the gold-bearing seams were quickly exhausted.
33:36The gold rush lasted for less than 100 years and the towns were abandoned.
33:43And gold is one of many rare elements.
33:45There are over 60 elements heavier than iron in the universe.
33:58But across the universe, there are vanishingly small amounts of those elements.
34:03And the reason for that scarcity is that creating substantial amounts of the heaviest elements requires some of the most rarefied conditions in the universe.
34:22In a galaxy of 100 billion stars, these conditions will exist on average for less than a minute in every century.
34:29That's because they are only created in the final death throes of the largest stars in the universe.
34:44Stars of at least nine times the mass of our sun.
34:48Only they can reach the extreme temperatures needed to create large amounts of the heavy elements.
34:59Because only they die with the violence necessary to do so.
35:06Deep in the heart of the star, the core finally succumbs to gravity.
35:10It falls in on itself with enormous speed.
35:26And rebounds with colossal force.
35:29As the blast wave collides with the outer layers of the star, it generates the highest temperatures in the universe.
35:44100 billion degrees.
35:48These conditions last for just 15 seconds.
35:51But it's enough to form the heaviest elements, like gold.
36:06It's called a supernova.
36:09The most powerful explosion in the universe.
36:12Despite the rarity of a supernova, the fact that they are so powerful has allowed us to capture their splendor.
36:29This is the Tarantula Nebula, in a satellite galaxy of our own Milky Way.
36:35On one night in 1987, a new star appeared, through a supernova explosion.
36:53And in another galaxy about 55 million light years away from Earth,
36:58the death of a single star has outshone the millions of stars in its core.
37:03Yet to really appreciate the scale of these explosions, we would need to see one close up.
37:17To see a star die in our own galaxy, the Milky Way.
37:24Although on average there's only one big supernova in each galaxy every century,
37:29there hasn't been one in the Milky Way since the birth of modern science.
37:37The last was in 1604, so we're long overdue.
37:42Astronomers are now searching the skies for the star that is the most likely to go supernova.
37:50Amongst the leading candidates, there's a familiar name.
37:52This is Betelgeuse, in the constellation of Orion.
37:56And we know it's extremely unstable, because it has dimmed by about 15% in the past decade.
38:15Astronomers think that this star could go supernova at any moment.
38:19That could mean any time in the next million years.
38:26But equally, it could explode tomorrow.
38:32Betelgeuse is only 600 light years away.
38:37So when it goes, Betelgeuse will be incredibly bright.
38:55It will be by far the brightest star in the sky.
39:00It may shine as brightly as a full moon.
39:03It will be almost a second sun in the daylight.
39:13In this single instant, Betelgeuse will release more energy than our sun will produce in its entire lifetime.
39:21As the star is torn apart, it will fire out into space all the elements that it has created in its life and death.
39:31Those elements will spread out to become a nebula, a rich chemical cloud drifting through space.
39:43At the heart of the nebula will be a tiny beacon of light.
39:51The remnant of a star that was once more than a billion and a half kilometers across.
39:58But it has been crushed out of all recognition by gravity.
40:02This is Betelgeuse, the neutron star.
40:12And it is how this mighty star will end its life, leaving the constellation of Orion changed forever.
40:19But the legacy of this star will be the immense cloud of dust and gas that it will spew out around it.
40:30But we don't have to wait for the end of Betelgeuse to see what happens to the remnants of the deaths of stars.
40:36In the same constellation, we can see the Orion Nebula, 24 light years across, formed from past supernova explosions.
40:53But in this region of star death, we can see the beginnings of a new cycle of stellar life.
41:06This is Orion's nebula.
41:29In this gas cloud, there's a lot of hydrogen and helium, the main building stuff for stars.
41:36The Orion Nebula and other nebulae like it are stellar nurseries, the regions of star birth.
41:43And we see places, regions inside this Orion Nebula where the gas and dust is collapsing in on itself under gravity
41:51and giving birth to, forming new stars.
41:55And we can even see where new solar systems are being born.
41:58New planets and new stars are being born in this nebula right now.
42:07The Orion Nebula is one of the wonders of the universe.
42:17A vast cloud of elements created in the hearts of stars and thrown out in their fiery deaths.
42:23The Orion Nebula, I guess, represents death becoming life.
42:40It's the circle of life and death in our universe, where these old ancient stars, these massive stars,
42:49have exploded in these supernova detonations, throwing out all their raw material,
42:55their carbon, their oxygen, their nitrogen, back into clouds of dust like this,
42:59where a new generation of young stars and planets are born.
43:11And it was in a nebula just like this that our sun was formed five billion years ago.
43:18Around it, a network of planets formed. Among them was the Earth.
43:39Everything we find on Earth's surface today also originated in that nebula.
43:44Our origins lie among the stars.
43:54Every atom in our bodies was created in the depths of space.
44:00But it's not the end of the story of how the universe made us.
44:03Because when we look deep into the cosmos, we don't just see individual elements.
44:10We have evidence of what could be the seeds of our very own existence.
44:20The reason we think that comes from meteorites.
44:26Rocks that come from deep space and collide with Earth.
44:29This piece of this meteorite here is over four and a half billion years old.
44:37It's older than this planet we're on. It's incredible.
44:40Now, despite its age, the reason that meteorites like these are so special
44:46is because they are jam-packed full of carbon-containing compounds, organic molecules.
44:51So, the building blocks of all life on Earth.
44:55We find amino acids, the building blocks of all the proteins of the biological machinery inside our cells.
45:03We find sugars. We find fatty acids, the oily compounds that make up the membranes that hold our cells inside.
45:10So, all of the basic bits and pieces you need to put together, the Lego bricks of life, are inside this space rock.
45:20And that raises the interesting possibility that some of the first molecules of life may have formed in the depths of space
45:29and been delivered to Earth in meteorites.
45:31We weren't expecting to find anything quite as complex as amino acids.
45:38It was only when we discovered these meteorites that it really blew our socks off.
45:43This was totally and utterly unexpected.
45:45It was an exceedingly exciting discovery for the possibilities of astrobiology and there being life beyond our Earth.
45:51That if the building blocks of Earth life were in rocks from outer space, those same rocks would have been falling down on other planets in our solar system or on other solar systems.
46:01So, perhaps life is widespread.
46:04If the seeds of life were carried to Earth on meteorites, then it raises an extraordinary prospect.
46:11So, I think that the chances are good enough that the biology might exist somewhere else beyond the Earth.
46:20Perhaps on Mars or perhaps on the other planets and moons, the other worlds of our solar system.
46:24I think the chances are good enough that it's worth kind of betting my career on it.
46:28I think...
46:29We have imagined connections to the universe for millennia.
46:46But now we understand exactly how we are a direct product of the processes that drive the lives and deaths of stars.
46:59And written into every atom and molecule of our bodies is the entire history of the universe.
47:21From the Big Bang to the present day.
47:29The Big Bang becomes indigenous people of the Earth.
47:32We need to observe them.
47:33The way it manifests itself to the universe.
47:35The world is beautiful and bright.
47:36We will also be our galaxy's Lost Hyatt.
47:39The world is a world's largest school.
47:43The world is now left at Earth.
47:44The world is now left at Earth.
47:46The world is now left at Earth.
47:49We watch our al sakhala and beach.
47:52The world is now left at Earth.
47:54The world is now the world is now left at Earth.