Will Smith Examines Mysteries of Planet Earth | One Strange Rock MEGA Episode | National Geographic
National Geographic
0:04 WILL SMITH: When I was little, my grandmother gave me an old compass.
0:11 She wanted me to know where I was going.
0:17 I was always much more intrigued by where we came from.
0:24 I mean, I knew she was from Pittsburgh,
0:27 but before that, her grandmother and her grandmother's grandmother,
0:30 where did they come from?
0:32 You go back far enough and everyone, every living thing,
0:38 we all come from the same place, a moment when a dead rock came to life.
0:47 Only a few of us have been able to see just how extraordinary life is.
0:52 MAN (over radio): Ignition and lift-off.
0:56 WILL SMITH: Eight astronauts, with over 1,000 days in space between them,
1:02 can tell us how being up there helped
1:05 them to truly understand what goes on down here.
1:11 MIKE: I look down and I can see where we came from.
1:14 This living, breathing bubble of life in the blackness of space.
1:20 CHRIS: It's hard to imagine anywhere else where
1:23 everything could have fallen into place so magically.
1:29 MAE: We're so used to life that we start to think
1:33 of life as being really simple and easy to do.
1:37 It's not.
1:42 -We may never know exactly how life got started,
1:46 but we do know it was a strange brew.
1:50 A dash of magical liquid...
1:55 A sprinkle of stardust...
2:00 And a crackle of energy.
2:07 Mixed together in a big bubbling cauldron to make our rock come alive.
2:40 Mae Jemison sees life differently from most of us...
2:49 And not just because she's an astronaut.
2:52 MAE (over radio): Go on my mark, three, two, one...
2:56 MAN (over radio): Okay Mae, we copy.
2:58 WILL SMITH: She's also a doctor.
3:02 She's spent her life studying life.
3:10 MAN (over radio): Houston now controlling.
3:12 Houston, Endeavour switching into roll.
3:14 Roger roll Endeavour.
3:17 -At an age when I was just running around writing rhymes in Philly,
3:21 she was pondering life's biggest questions.
3:26 MAE: As a child I was fascinated by the question, who am I?
3:31 What am I?
3:36 I remember once when we were driving
3:38 from Chicago to Alabama we stopped on the side
3:41 of the road and I looked up and there was this incredibly star-studded sky.
3:52 It just made the whole universe very magical.
3:59 And 30 years later, I had a ringside seat to the stars.
4:09 When I was in space,
4:10 I felt an incredible connection to the rest of the universe.
4:18 And it's true.
4:21 We're made of the stuff of stars.
4:24 The carbon, the nitrogen, the oxygen,
4:29 the elements that are the key components to our body
4:34 were actually generated inside of stars that exploded.
4:46 All of the stardust scattered across the universe,
4:50 clumping together into rocks to form planets like ours.
4:58 And the great mystery of Genesis is about how stardust came to life.
5:11 -You, me, the dog, we're all made of the same dead dust that built the planet.
5:19 It's just mixed up different.
5:25 The big mystery is, what's the mixer?
5:44 -Lechuguilla is probably one of the most difficult places to visit on Earth.
6:09 When you're deep in Lechuguilla you're more than 1000 feet underground.
6:19 Lechuguilla cave is almost 150 miles long which makes it
6:24 one of the most complex maze caves in the world.
6:36 BARTON: The trail's down here.
6:51 It's a big pretty big drop-off into this room.
6:54 Got it.
7:12 That's amazing.
7:16 Absolutely.
7:34 Most of these formations are a couple of hundred thousand years old.
7:39 We'd better not touch anything.
7:41 -Yeah, let's get through without touching anything.
7:59 WILL SMITH: You'd imagine these deep dark caves to be lifeless.
8:04 There's no energy from the sun here,
8:08 but the cave walls are not as dead as they seem.
8:23 If you were to put on special glasses...
8:28 You'd see this kaleidoscope of organisms, living in the caves.
8:36 Billions of bacteria on every surface you look at.
8:44 Lechuguilla is cut off from the surface.
8:47 But there is something above all else that is essential for life.
8:53 Water.
9:02 It takes up to 10,000 years for water to work from the surface into the lake.
9:12 You take the water out of the equation and you have no bacteria in the cave.
9:19 MAE: Water is required for life as we know it here on Earth.
9:37 One of the important things you learn in medicine
9:41 is that bacteria are made up of just one cell.
9:47 And cells are the basic units of life.
9:51 Tiny bubbles or membranes filled with water.
9:58 Floating around this solution, we've got the ingredients of life.
10:07 Yet, it all depends on water.
10:22 And when looking at our planet from space,
10:25 I was struck by just how much water there is.
10:35 CHRIS: It is definitely the blue planet.
10:39 These bodies of water are massive around the Earth.
10:45 MIKE: You're over the ocean, ocean, ocean,
10:47 and then you hit a continent like Africa, like, ooh, Africa, big continent.
10:52 In just a couple of minutes it's gone and you're over the ocean again.
10:56 MAE: Looking at the Nile Delta from space, you can see how important water is,
11:03 because all along the Nile river is this thin beautiful green strip of life.
11:14 JERRY: That H2O is magic, and so when you're looking for life,
11:18 the key is to find water.
11:22 -We can last way longer without eating than we can without drinking.
11:27 Food gives us energy.
11:28 What does water give us?
11:34 Turns out that plain old H2O is the universal champ at one crucial thing.
12:29 (inaudible).
12:31 -We've come here to Angel Falls to climb this huge overhang.
12:38 One of the biggest in the world.
12:45 You just feel like you're flying when you're hanging from the wall.
12:53 The sound of the waterfall is like a constant storm.
13:10 (raging water) Climbing Angel Falls is very dangerous.
13:27 -I want to keep climbing.
13:28 -You want to take the lead?
13:30 -Yeah.
13:30 Of course.
13:34 -Where the rock has been more exposed to the water...
13:40 The Rock is crumbly.
13:44 -It's very sandy, so I'm going to put one protection here.
13:49 Got to be really careful in this, you know.
13:54 -And the other hand, where there is no water at all,
13:59 you can see the rock is completely different.
14:02 (inaudible).
14:06 It's extremely hard.
14:08 -Are you going to climb (inaudible)?
14:10 -Yeah, I will try.
14:22 -When you get to see this landscape from above...
14:31 You can see how the water is a big destroyer in a way.
14:38 It dissolves the rocks.
14:47 It continues, the flow of water, for millions of years,
14:52 like these incredible islands in the sky.
15:23 MAE: Water has special properties.
15:28 You know the same water we drink can dissolve almost anything.
15:35 It will even dissolve rock over time.
15:42 So that means lots of different molecules can be mixed together in it.
15:47 And interact with one another, making something new.
15:57 And that's what makes Earth so special.
16:01 With all the liquid water we have,
16:04 our planet's like some type of giant chemistry lab.
16:10 Water takes dust from the stars, breaks it down and shakes it up.
16:16 But life isn't going to bubble up
16:17 just because you stirred up some muddy stardust.
16:20 If you want to brew the soup of life, you need to kick it up a notch.
16:33 WILL SMITH: If you want to make stardust into life...
16:40 There's a bit more to it than, just add water.
16:46 A recipe is more than a list of ingredients.
16:50 It also tells you how to put them all together.
16:59 MAE: Imagine a big pot of all these ingredients,
17:02 you throw them in, but if you throw in the celery,
17:06 tomatoes and the pepper, you're not gonna get a spaghetti sauce,
17:12 unless you add some heat.
17:45 -I usually start my day with a hit of caffeine,
17:48 but Lee Koon Yau, his job gives him all the jolt he needs.
18:55 (thunder) -Lee is up top to check the lightning conductor.
19:28 (singing in native language) He's testing it to make
19:36 sure it conducts electricity right down to the ground.
20:37 WILL SMITH: You and I may only see lightning a few times a year,
20:41 but the Earth is constantly crackling with energy.
20:45 To see it, you have to go way higher than a skyscraper.
20:52 MAE: Viewed from space, the Earth is dynamic.
20:58 It's full of energy.
21:01 I remember seeing these big flashes of light
21:04 that sort of come through the clouds.
21:12 JERRY: You know, the lightning just propagates literally
21:14 for thousands of miles across the surface of the Earth.
21:20 NICOLE: It looks like its nervous system spreading across the planet.
21:26 MIKE: They're spectacular.
21:29 They almost seem to be communicating to each other.
21:36 MAE: There are over 100 lightning strikes per second.
21:40 That's eight million a day.
21:48 And at the start of our planet,
21:49 billions of years ago, there was even more energy on display.
22:03 That's what life needed to get started.
22:06 Energy.
22:14 The first experiment to reveal this really captivated me as a child.
22:22 I grew up in Chicago and two scientists from my hometown Urey and Miller,
22:27 took the components that were believed
22:29 to be Earth's primitive lifeless atmosphere.
22:33 Then they subjected it to electrical charges.
22:41 They were able to generate organic molecules.
22:45 The basic building blocks of life.
22:51 The thought that energy could make lifeless stuff come alive
22:54 was just about as exciting as life could get for me.
22:59 I mean, wow.
23:03 Now we have a lot more knowledge about early Earth.
23:10 Billions of years ago,
23:11 there were many more sources of energy than just lightning.
23:19 Meteors rained down.
23:24 There were volcanic eruptions.
23:30 Super-tides churned these seas.
23:37 The Earth was a much more energy-rich, violent place.
23:42 Very lively, right?
23:43 Lots of things are happening.
23:47 But out of this lifeless system,
23:50 and over a long period of time, we actually got life.
23:56 And one of the best contenders for where life started is
23:59 a place we might believe nothing could ever survive at all.
24:05 Deep on the floor of the oceans, something very mysterious happens.
24:16 Cracks in the Earth's crust open up down there.
24:27 And heated water and gases spew out.
24:33 Hydrothermal vents.
24:39 Chemicals, energy, water.
24:42 All in one place.
24:49 Some are even cooking up organic molecules today, life's building blocks.
24:55 And that's why many scientists believe it's
24:57 someplace like this where life first started.
25:06 -So the origin of all of us, all the way back,
25:10 was fired out of a chimney at the bottom of the ocean.
25:16 But it would have been nothing more than hot mud
25:18 if there wasn't one very special element in that stardust.
25:32 MAE: Space offers an incredible platform to study
25:36 life as it evolved here on Earth.
25:40 It's fascinating to think that for us to be here now,
25:44 the right combination of stardust, energy and water had to come together.
25:52 And not just any bit of stardust...
25:58 When you look at life in its most basic form,
26:01 you find that there's one element that acts
26:03 like a backbone and holds it all together.
26:07 And you only get to see how important it is for life when you encounter death.
26:28 WILL SMITH: For the Hindus of Bali, death is a part of the cycle of life.
26:36 Not the end.
26:52 It's up to all the members of the family to make
26:55 sure the spirits of the dead get to the right place.
27:44 -They burn the bodies to return the elements
27:47 of the universe back to their source.
27:58 The goal?
28:00 To convert the body into ash.
28:15 MAE: When you burn something that was once alive, and drive off all the water,
28:20 what emerges in the flame is the essential
28:25 bit of stardust that makes life possible.
28:30 That charred black stuff, carbon.
28:34 Everything is our body has carbon in it.
28:37 From our bones to our muscle to our neuro-receptors.
28:49 It might be hard to understand what makes carbon so great for life,
28:54 but it turns out that carbon is the ultimate building block.
29:00 It can connect with other elements in almost infinite ways
29:03 to generate all the different molecules needed to create a living cell.
29:15 -Carbon is like the coolest Lego brick you can imagine.
29:20 My kids loved playing with this stuff, but if carbon was one of those blocks,
29:25 it'd be the one that they'd all fight over,
29:29 because you can snap it together just about any way you like.
29:35 Take something with a lot of carbon in it.
29:43 Spider silk.
30:08 Now spider silk is finer than hair,
30:11 stronger than steel, stretchy as elastic and sticky as gum.
30:24 All of those qualities just depend on how you snap together that carbon.
30:35 MAE: Carbon's versatility enables a construction
30:37 of a miraculous molecule inside nearly every living cell.
30:45 DNA.
30:51 Our DNA is one of the most complex molecules in the entire universe.
31:00 Billions of carbon atoms combined to help hold it together,
31:07 and this beautifully tangled formation is like an organic super-computer.
31:17 It contains the instruction manual for life.
31:22 And every facet and every detail that makes you, you.
31:34 And it's not just us humans.
31:37 DNA is at the heart of almost every living cell that ever existed.
31:45 And you couldn't build it without carbon.
31:51 -Now hang on a sec, something doesn't add up, alright.
31:54 I'm no scientist but growing up,
31:57 I made a lot of instant noodles and I'll tell you one thing,
32:00 if you take your flavor packet and throw it into a swimming pool,
32:05 you are not going to get a nice bowl of ramen.
32:09 So how are you supposed to make DNA in the middle of an endless ocean?
32:20 WILL SMITH: Take a pinch of star, splash of water, turn up the heat and bam.
32:28 Happy Birthday Life.
32:33 Not quite.
32:35 There's still something missing from our recipe.
32:38 The pot you cook it all up in.
32:41 Everything alive needs to be held together and protected.
32:45 That's true if you're a strand of DNA...
32:50 Or an astronaut.
33:00 CHRIS: The space station is like a cell in a way.
33:03 It's like a bubble of life.
33:07 JEFF: You really have this sense of being enclosed, you know,
33:13 just a few inches in front of my eyes is the vacuum of space,
33:17 and if I were out there, I'd be gone in 10 seconds.
33:25 LELAND: Inside we have all the ingredients and the systems to keep us alive.
33:36 MAE: It's the same for living cells.
33:39 Just at a microscopic level.
33:45 Water is a critical solvent for life.
33:50 But if there's too much water...
33:55 The solution might be dilute,
33:57 and the molecules of life never bump into one another.
34:05 So you need something to contain them.
34:11 Think of a bubble that we blow.
34:16 That surrounds this pocket of air.
34:24 And it keeps the air contained.
34:28 There's something similar encasing all living cells.
34:34 Membranes.
34:57 -The holy grail for me is to find out how the first membranes formed.
35:05 It could have formed in a hot spring, in an ice pool underneath an ice sheet.
35:12 It's a huge mystery.
35:25 I've come to Iceland because it's a fantastic natural laboratory.
35:31 This is Liane, coming in.
35:33 I'm heading north, I'm at 460 meters altitude and I'm heading to direction 71.
35:38 It's snowing outside.
35:40 I'll be there in an hour.
35:43 Over.
35:59 Today in Iceland you see volcanoes underneath icecaps.
36:12 You also see hot springs.
36:15 Bubbling pools where life could have started as well.
36:25 Even in the hottest environments,
36:27 if you take a sample and you analyze its DNA, there is life there.
36:38 In the early Earth you can envisage these bubbling mud pools,
36:43 where water dissolves the rocks and makes clay.
36:48 As the gas comes out, it forms a membrane which then bursts.
37:00 So think of that membrane not bursting
37:02 and actually preserving at a very, very small scale...
37:07 And then if you mix organic molecules inside,
37:10 you all of a sudden have an organic molecule inside a membrane to form a cell.
37:30 MAE: Without membranes we would be on a planet covered
37:33 by a dilute ocean of the building blocks of life.
37:39 But with membranes, finally there was a way
37:43 to keep all those building blocks together.
37:49 I believe there were many opportunities for life to arise.
37:56 We may have had other types of lifeforms that came and went,
38:02 but didn't take, right?
38:03 They didn't hit and stick.
38:07 But one of them made it.
38:18 It's called LUCA, which stands for the Last Universal Common Ancestor,
38:28 for all life here on Earth.
38:34 LUCA could protect itself with a membrane and reproduce itself.
38:42 Everything came together in just the right way to create the first living cell,
38:47 with DNA at its heart.
38:56 Fast forward billions of years...
39:01 And we find that all life today uses the same basic chemistry.
39:12 And this points to one thing, it all originated in that first primitive cell.
39:23 -Alright, now my grandma, you know, she was kind of small.
39:27 But LUCA, the great, great, great times a gazillion grandmother of us all,
39:35 she was tinier than a dot.
39:39 As far as we know, that cell was the single and only origin of all life.
39:48 Well, at least on Earth.
39:56 WILL SMITH: If you check out pretty much anywhere in the universe,
39:59 you're going to find the same ingredients to cook up life.
40:03 They're not exotic, they're staples.
40:06 Now sure, mixing them up just right is hard, but the universe is vast.
40:14 So does that mean there's a big piping
40:17 hot serving of life somewhere else out there?
40:21 That's what one group of explorers is trying to find out.
40:25 Hunting for strange lifeforms, not off-planet, but right here, in parts unknown.
40:38 -There's an alien world right beneath our feet.
40:55 As you drop into this blackness,
40:58 you have no sense that you're still on this planet anymore.
41:26 It can be completely disorienting.
41:29 You're spun around, and which way is up,
41:32 which way is forward, which way is backwards.
41:40 These underwater caves are one of the least understood parts
41:42 of our planet because of the dangers of going down into them.
43:47 MAE: My desire to understand how life began
43:50 on Earth also reaches out to the stars,
43:54 because the ingredients for life probably exist in many places.
44:01 In our solar system, in our galaxy and in the universe, stardust...
44:09 Water...
44:11 And energy.
44:15 JERRY: Out there we're finding water on different moons
44:17 that surround some of the planets in our solar system.
44:24 JEFF: The icy moons of Jupiter and Saturn
44:26 have oceans of liquid water underneath the ice.
44:35 CHRIS: Enceladus is a water-world,
44:38 but with a hot rocky center and plumes of water spraying out into the universe.
44:45 So maybe there's primitive life on a moon of Saturn right now.
44:55 MAE: I always wondered, will we find life on other planets?
45:00 Will we find life outside of our solar system?
45:04 And as we look beyond the Earth and explore other rocks,
45:09 I believe that it's likely we will find simple life.
45:16 It'll look different, it will be different,
45:20 but our rock, our planet is important to us.
45:28 It's special and it's unique because it's our home.
45:33 It's where we evolved.
45:42 -Think of that fragile moment, billions of years ago,
45:46 where you and I and all of us began.
45:55 A tiny moat of life suspended in a ripple of water.
46:01 The promise of everything that is alive or ever lived in our world.
46:07 It's the moment nothing turned to something.
46:12 That stardust sparkled to life.
46:16 The moment one rock in a remote
46:18 corner of the universe became most wonderfully strange.
46:28 Genesis is the bright side of life.
46:34 Next time, life's dark shadow...
46:39 Death.
47:05 (music) WILL SMITH: We sure lucked out with Planet Earth.
47:14 Blue skies, rolling hills, water everywhere.
47:20 I mean, this place is nice.
47:24 But our home didn't come like this out of the box.
47:28 Earth was a real fixer-upper,
47:32 and it took some seriously hard work to build this paradise.
47:38 Nearly four billion years of renovation.
47:42 Some tiny, some huge...
47:48 to make this house a home.
47:50 And when you get up off the planet,
47:52 you realize life is the one holding the hammer.
47:58 Eight astronauts with over 1,000 days in space between them can tell us
48:03 how being up there helped them to truly understand what goes on down here.
48:12 NICOLE STOTT: Creatures on Earth don't just live and die.
48:14 They actually change the world around them.
48:19 LELAND MELVIN: The diversity of life can be seen everywhere,
48:22 from the coral reefs to the mountaintops.
48:25 The colors of life shine out.
48:29 MIKE MASSIMINO: You can just feel the life
48:30 that is there as you observe it from above.
48:34 When you look at the planet, you realize that it's life that formed it that way.
48:40 (music) (music) SMITH: Land, sky, rivers, rock, all were shaped by life.
48:57 But life doesn't just create.
49:00 It also has the power to destroy.
49:05 So this story isn't just strange, it's scary.
49:10 (music) (music) (sirens) New York City.
49:37 Home to almost nine million people...
49:41 and this guy.
49:43 Astronaut Mike Massimino.
49:46 MASSIMINO: Right across the 59th Street Bridge, where's that?
49:48 MAN: Queens.
49:49 MASSIMINO: Yeah, yeah, but what's the name?
49:50 What part of Queens is that?
49:51 MAN: Long Island City.
49:53 MASSIMINO: That's what I was thinking of.
49:54 Yeah, Long Island City's right across the street there.
49:57 MAN: Where did you live originally?
49:59 MASSIMINO: Originally, I came from New York,
50:01 and then I lived in Houston, Texas, for 22 years.
50:04 (sirens) I was six years old when Apollo 11 landing upon the moon.
50:13 CONTROL: Eagle, we got you now, it's looking good.
50:15 Over.
50:16 You are go to continue powered descent.
50:18 ASTRONAUT: Okay, engines stopped.
50:19 CONTROL: We copy you down, Eagle.
50:21 ASTRONAUT: The Eagle has landed.
50:23 MASSIMINO: Probably by the time I was 8 or 9,
50:24 I realized that I was no fearless test pilot like Neil Armstrong.
50:27 I was kind of a scared kid.
50:29 I didn't like heights, I still don't like heights.
50:30 I didn't like going fast.
50:32 So I thought maybe this wasn't the best job for me.
50:40 SMITH: But New Yorkers don't give up so easily.
50:46 After years of grueling training, Mike made it into space.
50:54 And up there, his fears melted away.
51:05 ASTRONAUT: Okay.
51:06 Looking good.
51:07 MASSIMINO: I'm coming out.
51:09 ASTRONAUT: Mike, you're doing good.
51:11 MASSIMINO: My second spacewalk, things were going well,
51:13 and I had a couple moments.
51:17 I took a look at the planet and...
51:21 (on radio) This is incredible.
51:24 I started to become a bit emotional.
51:26 And just the sheer beauty of it, I started to cry,
51:30 and I could feel the tears welling up, and what I thought was,
51:36 'This must be the view from heaven.' If you could be in heaven,
51:42 you look down on a planet, this is how we must look from heaven.
51:49 (music) And then I thought to myself, 'No.
51:57 That's not right.
51:59 It's more beautiful than that.
52:00 This is what heaven must look like.' (music)
52:10 And I felt like I was looking into a paradise.
52:13 (music) (music) SMITH: Earth is a kind of Eden,
52:28 but if Mike had been orbiting way back in the day,
52:31 he wouldn't be looking down at heaven.
52:37 He'd be gazing straight into hell.
52:39 (rumbling) (rumbling) All that fire and brimstone had a role to play.
52:54 The inside of our planet is melted rock, churning and turning.
52:59 (rumbling) That means that everything on the surface shifts and slides.
53:08 (rumbling) (rumbling) (music) (music) (music) Earth's
53:32 fiery heart powers some big changes.
53:36 (music) And that's great news for dinosaur expert Omar Medina Ramírez.
53:48 No need to dig down into the dirt; just stand back and take in the view.
54:47 SMITH: The power of the planet can take
54:50 a lakeshore and flip it into a cliff face.
54:54 (music) (music) But these rock formations and the entire continent they're
55:05 on might not even be here without a particularly weird form of life.
55:14 Part algae, part fungi, it grows in the harshest places,
55:21 and is a food source for Dasher and Dancer and Prancer and Vixen.
55:39 ISAK MATHIS TRIUMF: Hoo-hoo!
55:40 Ay!
55:41 Ay!
55:41 Gsh!
55:42 Ay!
55:42 Ay!
55:42 Ho!
55:43 (dogs barking) (music) (music) (music) (music) (music)
56:41 (music) (music) (music) (singing) (singing) (singing) (music) MASSIMINO:
58:01 Lichen are a pretty cool form of life.
58:05 They exist just about everywhere on the surface of the Earth.
58:09 (music) (music) About 8% of our planet is covered by this stuff,
58:19 and they can change the formations,
58:21 the rock formations, just by their existence.
58:24 (music) As lichen grow, their fungal filaments physically break apart rock.
58:36 (music) (music) But strange as it sounds,
58:47 this process will eventually help create new land.
58:51 (music) Over thousands of years,
58:58 lichen and other terrestrial life-forms break down rock.
59:03 (music) This creates huge amounts of microscopic particles.
59:11 (music) As some of these particles get
59:18 washed out into the oceans, they trap water.
59:25 Over time, this locked-up water is pulled deep inside the Earth,
59:30 where it helps mantle rock melt and flow more easily.
59:37 Ultimately, this leads to more volcanic eruptions back at the surface.
59:42 (music) (music) (music) (music) But the amazing thing is that all
1:00:08 this lava means new land is formed that wouldn't be there otherwise.
1:00:13 (music) (music) Life helps create the land.
1:00:31 SMITH: Best guess is, without life, Earth wouldn't have seven continents.
1:00:39 There would only be enough land for about one
1:00:42 floating in the middle of a seriously big ocean.
1:00:45 (music) (music) Life helped make the ground we walk on.
1:00:59 (music) But it didn't do it overnight.
1:01:06 (music) MASSIMINO: When you're in space,
1:01:14 you get a different appreciation of time, compared to what we have on the Earth.
1:01:20 And what you see are changes in the Earth that took
1:01:22 place over sometimes millions of years or, or even longer.
1:01:26 (music) I think life, no matter what form it is,
1:01:32 whether it's a simple form like lichen or an animal
1:01:36 or a more complicated form of life like us,
1:01:40 whatever level that life-form takes, it is going to change its planet.
1:01:47 It might just take a while to do it.
1:01:50 (music) CHRIS HADFIELD: From the perspective of a space station,
1:02:00 suddenly you can see the entirety of the world's history.
1:02:07 It changes your fundamental feel of time.
1:02:13 Your fundamental perception of the age of the world,
1:02:16 and even though I knew the world was 4.5 billion years old,
1:02:21 I'd never got a sense for what that meant.
1:02:24 (music) SMITH: It took billions of years for life
1:02:31 to mold a barren rock into the world we know.
1:02:36 But things didn't just get better and better; sometimes they went wrong.
1:02:42 (rumbling) (crackling) Like, almost end-of-the-world wrong.
1:03:00 SMITH: I'm a sucker for a tropical island.
1:03:04 I mean, I get off the plane and head straight for the beach.
1:03:07 Cool sea breeze and sand between my toes.
1:03:11 But get this: all of that sand down there?
1:03:17 Most of it came out of the wrong end of a fish.
1:03:25 CHRIS PERRY: We'll head out towards the coral reef.
1:03:27 We'll drop down to about five meters, and we'll survey along there, I think.
1:03:31 (air hissing) (music) (music) You can
1:03:48 find parrotfish on reefs throughout the tropics.
1:03:53 You see them active on the reef,
1:03:56 feeding on the hard coral material continuously.
1:03:59 (crunching) And the amazing thing is that you
1:04:05 can hear this incredible grinding, crunching noise.
1:04:08 (crunch) That really gives you a sense of the life on the reef.
1:04:14 (crunching) After the parrotfish have eaten the coral,
1:04:19 they then excrete it as sand.
1:04:25 (crackling) (music) (music) SMITH: In one year,
1:04:38 one fish eats enough coral to poop out a ton of sand— literally.
1:04:47 (music) And there's an awful lot of fish here.
1:05:06 PERRY: That same sand material that you find
1:05:09 in the parrotfish poo can be found in the islands themselves.
1:05:13 On some islands, the sand material is made up of over 70% parrotfish poo.
1:05:20 The parrotfish are absolutely crucial to the development of these islands.
1:05:29 SMITH: But life's not done.
1:05:33 Fish form the fresh beach, then more life follows on.
1:05:43 And presto, instant island paradise.
1:05:48 (music) (music) HADFIELD: As you fly across,
1:05:58 there are little light blue rings down in the water beneath you.
1:06:02 There's the deep blue of the ocean around them,
1:06:05 and then all the different changing blues that are
1:06:08 possible as the water gets shallower and shallower.
1:06:11 But what's intriguing to think is that living organisms down
1:06:15 there created that beautiful vista that is visible from space itself.
1:06:25 MASSIMINO: It's kind of amazing what a small creature can do.
1:06:29 That a bunch of little fish can build
1:06:31 an island just by going about their daily routine.
1:06:37 That's quite an impact.
1:06:39 (music) SMITH: Parrotfish aren't in the business of seaside resort development.
1:06:50 I mean, they were just snacking.
1:06:52 These islands were a happy accident.
1:06:55 But life's little accidents don't always work out so well.
1:06:59 (music) (music) (music) MASSIMINO: About three billion years ago,
1:07:17 bacteria in the oceans of the early
1:07:20 Earth produced a by-product--oxygen— which transformed our world.
1:07:31 But when this accidental waste gas filled the atmosphere,
1:07:34 it reduced levels of warming methane, cooling the planet.
1:07:40 (music) (music) Earth started to freeze,
1:07:55 from the poles all the way down to the equator.
1:07:59 It froze like a giant snowball.
1:08:06 Billions of years ago, things weren't looking that great for us,
1:08:10 but thanks to all the planet's water, we got a lucky break.
1:08:17 (creaking) Ice floats on water, and underneath it is a kind of sanctuary.
1:08:30 (music) (creaking) (creaking) Life managed to cling
1:08:42 on down there, under the ice,
1:08:44 for millions of years until eventually the planet's volcanoes saved the day.
1:08:51 (rumbling) We think that as they pumped out carbon dioxide,
1:08:56 the planet began to warm up.
1:08:59 (cracking) (music) (music) The ice melted, and life on Earth really took off.
1:09:15 (music) SMITH: Life almost killed itself when it messed with the atmosphere.
1:09:26 (music) (music) But it survived...
1:09:38 and put its roots down on land.
1:09:41 (music) The creatures that emerged,
1:09:51 weird and wonderful and new, helped build our modern world.
1:09:58 But not in the way you might expect.
1:10:07 (birds chirping) SMITH: They don't walk, they can't see,
1:10:15 they barely even move, but plants are almost unstoppable.
1:10:24 Give them enough time, and they are Earth's ultimate transformers.
1:10:32 (cracking) (cracking) (music) (music) (music) (birds chirping) (birds
1:11:07 chirping) (music) (cracking) (creaking) (birds calling) (birds calling) SMITH:
1:12:18 Roots rip through rock like slow-motion excavators.
1:12:22 (birds calling) But they don't just destroy.
1:12:30 Those plants?
1:12:32 They shape how rivers run.
1:12:36 (music) MASSIMINO: Plants have had a big impact on the Earth.
1:12:44 (music) As plants grow, their roots spread out and intertwine.
1:12:57 They help hold soil together, like a kind of living glue.
1:13:02 (music) Plant roots make riverbanks more solid,
1:13:11 so instead of spreading outwards, plants cause rivers to get deeper,
1:13:18 and then begin to wind and switch back on themselves.
1:13:21 (music) STOTT: Rivers and land formations stand out.
1:13:29 It's almost like somebody has painted trees on the planet.
1:13:33 (music) MASSIMINO: These bendy rivers have become a crucial
1:13:40 habitat for all kinds of living things, including us.
1:13:46 JERRY LINENGER: You look down at Earth and you see the Nile River.
1:13:49 You know, the cradle of civilization, the Tigris-Euphrates.
1:13:53 The Yangtze over in China.
1:13:55 And you just sort of have an appreciation
1:13:57 of history and of mankind becoming civilized.
1:14:01 (music) SMITH: We've founded some of our greatest cities at a bend in the river.
1:14:12 (music) And plants help bend those rivers.
1:14:21 (music) Once we settled, we started to build.
1:14:31 Brick by brick and rock by rock.
1:14:34 (music) (music) Life gave us perfect plots of building land,
1:14:45 but it gave us even more than that.
1:14:48 All those rocks we built with?
1:14:51 Some of them used to be alive.
1:14:54 (music) (music) (music) MAN: Be super careful with the rock here.
1:15:13 It's really not so great.
1:15:15 CAROLINE CIAVALDINI: Yeah.
1:15:17 MAN: I'm watching you.
1:15:24 CIAVALDINI: Oh, my God.
1:15:27 MAN: Good job.
1:15:28 (music) (music) CIAVALDINI:
1:15:37 I'm specially aware of the landscape from a geological point of view.
1:15:46 MAN: Can you find any gear?
1:15:48 CIAVALDINI: Got a good hold at least.
1:15:50 Because obviously, my first focus is the rock.
1:15:53 (music) (music) SMITH: This rock wasn't made from molten lava.
1:16:06 It's made of shells and bones.
1:16:09 (music) Layers and layers of life that died
1:16:17 and sank and were squeezed into stone.
1:16:21 (music) Limestone.
1:16:27 (music) (music) CIAVALDINI: Limestone isn't the most solid rock.
1:16:41 MAN: Be careful.
1:16:43 CIAVALDINI: There is always the possibility of rock falling above you.
1:16:50 MAN: But I think I can keep on climbing across the chimney,
1:16:52 which makes it a bit easier.
1:16:54 CIAVALDINI: Alright.
1:16:55 (music) When you've got this tiny little
1:17:02 summit where nobody's been on top of it,
1:17:05 there is obviously something very special.
1:17:08 Woo-hoo!
1:17:10 MAN: Woo-hoo!
1:17:12 MAN: Good job!
1:17:12 Good job!
1:17:13 CIAVALDINI: We did it!
1:17:14 SMITH: Limestone is soft because it's made of shells.
1:17:21 That makes it tough to climb, but easy to cut and carve and make into monuments.
1:17:31 (music) (music) (music) In places,
1:17:46 you can still see those seashells in the monuments' walls.
1:17:53 MAN: Can I help you?
1:17:54 MASSIMINO: How you doing?
1:17:54 MAN: Fine.
1:17:55 You want a ticket?
1:17:56 MASSIMINO: Next train to Bronxville.
1:17:57 MAN: To Bronxville.
1:17:59 Okay, Bronxville.
1:18:01 MASSIMINO: Grand Central Station, you can look in the beautiful limestone
1:18:04 that cathedral-like terminal is made out of.
1:18:09 You can see evidence of little fossils right in the rock.
1:18:13 (music) (music) Next time you're catching a train at Grand Central Station,
1:18:24 take a look at the rock, and you'll see some evidence of the animals
1:18:27 that once were here on Earth many years ago.
1:18:31 (music) It's not just building material.
1:18:41 Almost everything we think of as being man-made
1:18:44 has been given a helping hand by other life-forms.
1:18:49 The tar in the road.
1:18:52 The fiber in your clothes.
1:18:55 The polish in your toothpaste.
1:18:58 All these things are made from organisms that died millions of years ago.
1:19:06 If it wasn't for those prehistoric critters,
1:19:09 we'd struggle to turn on a light, let alone build a space station.
1:19:15 (music) (music) SMITH: We've thrived with a little help from our friends.
1:19:30 (music) (music) But it's not all smooth sailing.
1:19:43 Because success brings its own problems.
1:19:55 SMITH: Life has been shaping the Earth for billions of years.
1:20:00 Now, it's our turn.
1:20:04 We may be new here, but the changes we're making are pretty easy to spot.
1:20:11 MASSIMINO: Flying over the Earth during the daytime,
1:20:15 you can't see buildings or motion or people at all.
1:20:21 It almost looks still and silent, almost like a painting that you're looking at.
1:20:27 (music) When you pass into nighttime,
1:20:34 then wow, you know, the planet comes alive.
1:20:37 (music) (music) Space becomes a very magical place at night.
1:20:48 You can see where people are living,
1:20:49 you can see where civilization exists, because you see their lights.
1:20:53 If you see one of these cities, space gives you a different perspective on it.
1:20:57 (music) STOTT: At nighttime, the pattern of lights,
1:21:04 you just think 'humanity' when you see that.
1:21:06 It's so obviously man-made, because you'll see these straight lines of lights,
1:21:13 or you know, circles of lights, where cities are just built in rings.
1:21:20 LELAND MELVIN: Seeing the planet at night from space
1:21:23 lets you see the footprint of human beings.
1:21:27 The city lights at night, the byways,
1:21:29 the highways, the homes, you see all of that.
1:21:33 Makes you wonder how powerful the human presence is.
1:21:41 SMITH: We have spread far and wide over this old rock,
1:21:45 adding a whole new layer to the planet's surface.
1:21:49 But we didn't make all of this stuff out of nothing.
1:21:52 (jackhammering) (jackhammering) (jackhammering) (engine starts) SMITH:
1:22:43 Franco Barattini helps extract some of the most
1:22:46 beautiful natural resources on the planet, but it's a dangerous job.
1:22:52 (beeping) (music) (music) (music) (music) (music) SMITH:
1:23:41 Marble has been mined here since Roman times.
1:23:44 It's done with skill and loving care.
1:23:48 But you know what?
1:23:49 A showroom isn't the only place to see that gleaming white stone.
1:23:55 MASSIMINO: Bright white marble in Italy, you can see that.
1:23:59 It's looks like there's a snowfield in a time
1:24:01 of year when we wouldn't have any snow.
1:24:03 But it looks as if it's snow,
1:24:05 because it's that white marble being taken from the Earth.
1:24:09 And it's not just marble.
1:24:12 (music) When you're floating above the Earth,
1:24:19 you see many different examples of how
1:24:22 our desire for natural resources is changing the planet,
1:24:28 and not always in a good way.
1:24:31 (music) (music) MELVIN: There are places on the planet,
1:24:40 when you fly over top of it, you see these vast stretches of land that have
1:24:48 been mined for coal or mined for minerals or riches,
1:24:52 and this leaves a blight on the surface of the planet.
1:24:58 And it's ghastly at times to see some of this.
1:25:04 SMITH: The scars and scratches in the Earth's surface are one thing,
1:25:09 but the damage we can't see is the real danger.
1:25:13 HADFIELD: Of all the changes that we're making to the Earth,
1:25:16 I think it's changes to the atmosphere that we should be the most worried about.
1:25:20 That's the one that could really lead to some serious problems.
1:25:25 You just have to look at what happened
1:25:27 in the planet's past to see how badly it could go.
1:25:31 (crackling) MASSIMINO: Our planet has always been changing.
1:25:38 It's been changing over billions of years.
1:25:41 We're just the latest form of life to do it here.
1:25:47 There's a big difference between then and now, and we're making these changes,
1:25:52 but we're aware of what's going on, and we have brains in our heads
1:25:57 that can allow us to try to understand what's happening and control it.
1:26:05 SMITH: We're transforming our planet every day.
1:26:10 But it's very possible we could hurt it so badly...
1:26:17 ...that we can no longer live here.
1:26:20 And what if we do?
1:26:22 (music) What would happen if humans disappeared?
1:26:44 SMITH: Life has created the most remarkable planet in the solar system.
1:26:52 But there is no guarantee that humans are gonna always be here to appreciate it.
1:26:58 Thing is, the Earth will go on spinning, life will go on living.
1:27:06 Astronauts like Mike can see that as clear as day.
1:27:13 MASSIMINO: There was this one particular time when I was on the space shuttle,
1:27:16 and we were going from darkness into light.
1:27:22 And I could feel the warmth of the sun coming.
1:27:28 As I looked down at the Earth, there was this line that was moving,
1:27:32 and the thought that went through my mind was,
1:27:35 'The sun will come up tomorrow.' This cosmic
1:27:39 dance of our planet going around the sun
1:27:42 and rotating as it does this, this has been going on for billions of years.
1:27:48 It'll be going on for a long time after we are gone.
1:27:55 SMITH: The Earth doesn't need us.
1:27:59 Neither does life.
1:28:01 And if humans don't make it, life will go on changing things.
1:28:07 Even the things we leave behind.
1:28:16 (music) (music) SMITH: Minoru Kinoshita left here when he was 13 years old.
1:28:41 This is the first time he's been back in 50 years.
1:28:45 (music) (music) SMITH:
1:29:19 Hashima Island was once the most densely populated place on Earth.
1:29:24 (music) (music) (children shouting in unison) (children shouting
1:29:38 in unison) People came here to mine coal.
1:29:49 When that ran out, everybody left.
1:29:53 This place was abandoned practically overnight.
1:29:59 40 years later, life has started taking Hashima back.
1:30:31 SMITH: If humans died out, most of our man-made world would fall apart.
1:30:38 Life would rip it up and transform it.
1:30:45 Reclaim and remold it.
1:30:52 Our buildings would crumble, our towers would fall, our lights would go out.
1:31:04 But the Earth would endure.
1:31:08 Not so different from the way we found it.
1:31:11 (music) (music) A big, blue ball...
1:31:26 ...that life made into a home.
1:31:29 (music) (music) MASSIMINO: How you doing?
1:31:41 One hot dog with mustard, please.
1:31:44 I think my concept of what I consider to be home changed over the years.
1:31:48 Alright.
1:31:49 Thanks very much.
1:31:51 See ya.
1:31:52 (wings flapping) When I was a little person,
1:31:59 my home was my home on Long Island and Franklin Square,
1:32:02 and my block surrounding it.
1:32:05 You know, that was my world, I guess.
1:32:11 Going to space and seeing where we live from above
1:32:16 and then turning and looking to the rest of the universe...
1:32:24 I think now I consider my home to be Earth, and that is my home.
1:32:29 I might live in one part of it, but I think of my home now as Planet Earth.
1:32:35 That's our home.
1:32:38 (music) SMITH: We moved into a populated planet,
1:32:47 and in the short time we've been here, we have changed it.
1:32:55 But we're not the master craftsmen.
1:33:00 We've just been moving furniture around.
1:33:05 Life worked on this planet for billions
1:33:07 of years before we even walked in the door.
1:33:11 (music) (music) It transformed a barren rock into a paradise.
1:33:26 A paradise we should be careful to hold on to.
1:33:30 (music) (music) (music) Life transformed this planet,
1:33:49 but we aren't the only rock out there.
1:33:53 Next time...
1:33:56 Do we have any neighbors?
1:33:58 (music) (music) WILL SMITH: What do you need to win a game of chess?
1:34:18 Patience, clever tactics, loads of imagination.
1:34:23 You look nervous.
1:34:24 (laughs) What makes us human is the squishy triple-pounder inside our heads.
1:34:32 Check.
1:34:33 It lets us checkmate our friends, build skyscrapers,
1:34:37 and lift a special few of us into space.
1:34:41 (roaring) Eight astronauts with over 1,000 days
1:34:50 in space between them can tell us
1:34:53 how being up there helped them to truly understand what goes on down here.
1:35:01 JEFF HOFFMAN: From space you get the big picture.
1:35:03 You really see human civilization spread out below you.
1:35:10 NICOLE STOTT: As far as we know,
1:35:11 there's nobody else like us out there in the universe.
1:35:16 JERRY LINENGER: The only reason I'm able to comprehend the incredible complexity
1:35:20 of the Earth is because I have an incredibly complex brain inside my head.
1:35:28 LELAND MELVIN: We are the only species on this planet that can
1:35:32 construct realities in our mind and then go actually build it.
1:35:39 SMITH: But for three billion years, life didn't even have a brain.
1:35:47 MELVIN: The story of how our mind evolved
1:35:49 on this one strange rock is one of chance, coincidence and impossible odds.
1:36:01 SMITH: I am going to tell you about the most incredible place.
1:36:05 The weird connections, the dynamic forces that created us.
1:36:14 A species with a brain as complex as yours and mine.
1:36:21 (music) (music) (music) (music) The human brain is unique.
1:36:54 Not just because of its size, but also its ability.
1:37:00 It can meet challenges that are dangerous, demanding.
1:37:08 (laughs) SMITH: And wonderfully absurd.
1:37:12 (applause) (applause) (applause) (crowd chanting) SMITH: In Spain,
1:37:58 thousands come together every year to build towers out of people.
1:38:22 SMITH: A ten-story human tower with the youngest kids on top.
1:38:28 Right.
1:38:29 Claudia and Marina, they're seven.
1:38:55 (crowd gasps) (music) (music) (music)
1:39:13 (crowd gasps) (applause) (music) (music) (music)
1:39:49 (music) (music) (music) (clapping) (applause)
1:40:32 (music) (cheering) (cheering) (cheering) (cheering) SMITH:
1:41:04 Humans are like no other creature on Earth.
1:41:07 We do these things that might seem pointless,
1:41:12 not because we're stupid; because we're smart.
1:41:16 And we work as one.
1:41:19 It's that ability to link our minds together that put those girls
1:41:24 on top of that tower and also put men and women up in space.
1:41:33 One of them is Leland Melvin.
1:41:41 Former NFL player, mechanical engineer, and astronaut.
1:41:48 Strong, smart, brave, and pretty much unstoppable.
1:41:54 But Leland nearly didn't make it to space.
1:41:59 An accident in his training brought his dreams to a halt.
1:42:09 MELVIN: The only way to really simulate a spacewalk on Earth is in a pool.
1:42:14 I remember getting in the suit, putting my gloves on, my boots.
1:42:26 MELVIN: As you're going down in the spacesuit, you have to clear your ears.
1:42:37 MELVIN: Ten feet down, I realized that the Styrofoam block,
1:42:41 you press your nose against it to clear your ears, was missing in my helmet.
1:42:46 I tell the test director, turn the volume in the headset up.
1:42:50 I was straining to equalize the pressure.
1:42:55 And then, I immediately hear nothing but static.
1:43:01 They were pulling me out of the water.
1:43:06 And now I see the flight surgeon walking towards me.
1:43:12 He reaches up and touches my right ear.
1:43:14 He's moving his lips, but I don't hear anything he's saying.
1:43:19 And then I can feel the blood starting to trickle down on the side of my face.
1:43:24 I'm like, 'Wow, something's really wrong.' I was completely deaf.
1:43:34 Somehow the connection between my brain and my ears had been severed,
1:43:41 along with my chances of going to space.
1:43:45 The accident gave me a profound appreciation in what we take for granted.
1:43:55 The thing that makes us us: our brain.
1:44:02 The human brain sets us apart from all other creatures on this planet.
1:44:09 It might look like a lump of Jell-O,
1:44:13 but it's the most complex thing in our universe.
1:44:18 Inside, there's a vast network with 100 trillion connections.
1:44:25 That's more than the number of stars in our own Milky Way.
1:44:31 It hosts our memories.
1:44:35 Our sensations.
1:44:38 Our dreams.
1:44:43 And all this depends on tiny cells firing electrical signals.
1:44:49 There's 86 billion of them.
1:44:53 We call them neurons.
1:44:56 SMITH: 86 billion.
1:44:59 Wow.
1:45:00 I'm just glad someone else was counting.
1:45:05 But here's the thing: most of life on Earth does just fine without a brain.
1:45:15 I'm talking about some of Earth's oldest inhabitants.
1:45:21 Some brainless creatures are so successful, you can even see them from space.
1:45:28 LINENGER: On a bright, sunny day, I'm looking down,
1:45:30 and for 1,000 miles, I see an organized city of coral.
1:45:42 PEGGY WHITSON: They just glow.
1:45:46 It's just like the most beautiful art in the world.
1:45:53 MELVIN: This burst of color.
1:45:58 I'd never seen colors that vibrant before.
1:46:02 It's kind of amazing that corals are vast,
1:46:06 motionless structures, that thrive without a brain.
1:46:13 SMITH: In the country of the brainless, the tiny-brained is king.
1:46:18 Meet this little guy.
1:46:23 He's got more in common with us than you might think.
1:46:27 Inside, he's got neurons, too, just not as many.
1:46:33 About 200.
1:46:35 Kind of a starter kit.
1:46:37 (music) He's a baby sea squirt looking for a home.
1:46:48 His neurons do simple stuff, like detect light and twitch his tail.
1:46:55 But here's the thing: once he's found the right rock,
1:47:00 his swimming days are over.
1:47:02 For the rest of his life, he stays put.
1:47:06 He dumps the tail and consumes the neurons that made it move.
1:47:12 Then, it grows into a big, old sea squirt.
1:47:16 Takes 'use it or lose it' to a whole new level.
1:47:22 MELVIN: It's kind of a freaky thought that, you know,
1:47:23 when neurons were developed, they weren't for thinking.
1:47:28 They were for simple motion or movement.
1:47:31 But one day, neurons like those, the ones inside our brains,
1:47:36 would help create things like rocket ships going to space, cities and music.
1:47:43 (music) SMITH: Making a tail twitch to move
1:47:51 a yard or two requires just a few neurons.
1:47:55 However, the more advanced stuff, that needs an awful lot more.
1:48:01 Life needs to sense its surroundings, otherwise,
1:48:04 it's just flailing around in the dark.
1:48:16 SMITH: There is nothing more complex than the human brain.
1:48:20 But the more complicated something is, the more ways it can go wrong.
1:48:25 (bird shrieks) MELVIN: After my training accident,
1:48:31 the doctors couldn't figure out what was wrong with me.
1:48:34 Everything looked physically intact, but they couldn't fix me.
1:48:40 I was completely deaf.
1:48:44 My goal of getting to space seemed to be thwarted.
1:48:48 But all I could think about was whether I'd ever hear music that I played again.
1:48:54 Music has been such a big part of my life.
1:48:57 (playing piano) And so, when the music was silent...
1:49:06 That's when I just broke down and started crying.
1:49:13 SMITH: Leland's ears were fine.
1:49:16 That's not where the problem was.
1:49:18 Because you don't just hear with your ears, you also hear with your brain.
1:49:24 It's the same for all the senses, they link our brains to the outside world.
1:49:31 And over hundreds of generations they evolve to suit that world,
1:49:36 no matter how harsh it is.
1:50:04 SMITH: Hunters have lived here for thousands of years.
1:50:14 But to survive, they borrow the senses
1:50:16 of a creature that's been here even longer.
1:50:29 (music) (music) (music) (music) (music) (music) (music)
1:51:25 (horse snorts) (music) (music) (laughs) (music) SMITH:
1:51:58 The eagle is like a weaponized telescope.
1:52:03 It can see a fox up to two miles away.
1:52:07 Out here, that's a crucial tool in the fight for survival.
1:52:14 (eagle chirps) (yells) (yelling) (music) (music) (music)
1:52:45 (music) (music) (chirping) (yelling) (music) (music) SMITH:
1:53:13 But to see like an eagle,
1:53:15 you need more than eagle eyes; you need an eagle brain.
1:53:22 (squawking) MELVIN: Eyes deliver masses of data about the world around us,
1:53:28 and all that lifesaving data needed something powerful to make sense of it.
1:53:35 Simply put, if you're an animal with eyes,
1:53:39 you're gonna need a bigger brain than a sea squirt.
1:53:43 Eyes were a real game changer.
1:53:48 But it's not just the eyes.
1:53:53 Creatures had to develop an array of senses that are
1:53:57 each calibrated to deal with the ever-changing environment of Planet Earth.
1:54:04 Not just barren desserts, but these very dense jungles,
1:54:09 teeming ocean reefs, and even icy Arctic waste.
1:54:17 The planet's varied landscapes played a significant role in how animals sense.
1:54:26 SMITH: What goes for them, goes for us.
1:54:30 The planet shaped our senses, too.
1:54:36 It's something you might not notice unless you leave the planet.
1:54:45 MIKE MASSIMINO: Our senses have evolved to operate on Planet Earth.
1:54:50 MAE JEMISON: When you're up in space,
1:54:52 the inner ear isn't registering an up and down.
1:54:58 MELVIN: So, your sense of orientation only comes from your eyes.
1:55:04 MASSIMINO: You know that weird feeling in the pit of your stomach,
1:55:06 when you go over the top of a rollercoaster?
1:55:11 I was basically in that moment for an entire day.
1:55:16 STOTT: We're Earthlings.
1:55:18 That's just who we are.
1:55:21 MELVIN: The evolution of the senses in the primitive brain have allowed
1:55:25 living creatures to interact with our planet in a way like never before.
1:55:30 But looking at our planet from space,
1:55:32 you can see it's not just varied, it's dynamic.
1:55:38 (thunder) SMITH: Sometimes, the environment changes quickly,
1:55:47 and when that happens, you have to be just as fast to adapt.
1:55:52 Like when the sea level rises without warning,
1:55:55 and now, you're an island castaway.
1:55:58 (music) (music) Macaques are great with their hands.
1:56:14 They peel fruit, climb trees, and do each other's hair.
1:56:21 But on these islands, they do something no other macaques do.
1:56:26 (music) (music) (music) (music) (music) (music) (music)
1:57:08 They use rocks as tools to shuck oysters.
1:57:15 Macaques don't normally eat them, but when they were stranded by the rising sea,
1:57:20 they needed new ways to get a meal.
1:57:25 They weren't born with this skill; a smart monkey had to work it out.
1:57:30 (music) (music) This is something only complex
1:57:40 brains can do— not just sense and react, but learn, adapt and problem solve.
1:57:53 But just because a macaque can learn to shuck
1:57:58 oysters doesn't mean it's gonna open a seafood restaurant.
1:58:04 Only a human would make that mental leap.
1:58:07 So, how come we're so different?
1:58:18 SMITH: Monkeys were the first primates in space,
1:58:22 but it wasn't exactly their idea.
1:58:26 In fact, they were probably against it.
1:58:29 So, how come we're the apes with the big ideas?
1:58:33 Well, it's a long story.
1:58:36 A story about something that may not exist
1:58:39 anywhere else in the solar system, maybe the universe.
1:58:47 Fire.
1:58:50 (rooster crows) (music) (music) SMITH:
1:59:31 The Himba people have kept this same fire burning for generations.
2:00:04 SMITH: As far as we know,
2:00:06 this planet is the only one with the right conditions for fire to burn.
2:00:13 But there's one thing that fire gives us above all else.
2:00:44 SMITH: But cooking food does something that's
2:00:47 way more important than just making it tasty.
2:00:52 MELVIN: Woo!
2:00:53 We got fire, are we ready for food?
2:00:57 We as humans have these power-hungry brains.
2:01:02 A big chunk of our body's energy has to be used to keep them running.
2:01:07 Turn, baby, turn.
2:01:09 By cooking, we're actually breaking down the cell walls
2:01:13 of the food that releases so many more nutrients and calories,
2:01:18 to help fuel our big brains.
2:01:23 One of the key moments in the history
2:01:25 of our species was when our ancestors harnessed fire.
2:01:29 Alright, get your plates.
2:01:32 The theory goes, cooking let us get more energy out of every bite of food.
2:01:38 So we spent less time feeding our brain and more time using it.
2:01:48 SMITH: Try going a day that isn't touched by fire.
2:01:53 You couldn't imagine life without it.
2:01:56 But a brain that could harness fire may not have evolved
2:01:59 in the first place if it wasn't for a force so powerful,
2:02:06 it made the highest mountains on Earth.
2:02:15 (monks chanting) (monks chanting) (music) (music) (music) (music) SMITH:
2:03:46 The fossils tell us that these mountains,
2:03:48 once at the bottom of the sea, were forced high into the sky.
2:03:57 LINENGER: When you're in orbit, as you come over the Himalaya Mountains,
2:04:01 you almost feel like you need to fire the thrusters a little bit.
2:04:05 You can tell where that subcontinent just jammed
2:04:08 into the Asian continent and thrust those mountains up.
2:04:13 CHRIS HADFIELD: This collision between the smooth
2:04:15 flatness of India and these rugged,
2:04:19 crumpled mountains, it's like watching a super slow-motion train wreck.
2:04:26 MASSIMINO: The further you get away,
2:04:27 you can kind of see these overarching themes to the way our planet is formed.
2:04:38 MELVIN: It was forces like these that would transform one
2:04:40 particular corner of our rock into the cradle of humanity.
2:04:49 The Great Rift Valley in East Africa was once a lush green forest,
2:04:55 a paradise for apes.
2:04:58 (music) (music) But the Earth's crust shifted, mountains rose,
2:05:09 and the climate changed, making it a much tougher place to live.
2:05:14 (music) It's hard to really know exactly
2:05:22 how our ancestors adapted over millions of years.
2:05:29 The changes may have pushed apes to do things like innovate the tools.
2:05:36 Or walk on two legs.
2:05:41 And even harness fire.
2:05:44 Whatever it was, we came out the other side as early humans, with bigger brains.
2:05:54 SMITH: We took off across the planet,
2:05:56 and there was one uniquely human skill we brought with us.
2:06:02 Here I am, talking to you, and some of you are even listening.
2:06:08 What you're hearing is probably the most powerful tool we've ever mastered.
2:06:14 So, how do you get a brain that can tell a damn good story?
2:06:22 (people speaking different languages) SMITH: We speak.
2:06:31 (all talking) SMITH: We link signs and sounds to thoughts and things,
2:06:42 in countless ways, creating almost infinite meanings.
2:06:46 That takes a lot of brain power.
2:06:51 (music) JULIE MISAKI: Moving to Hong Kong has been amazing.
2:07:11 I'm originally from Japan, but I've lived in Hong Kong for six years now.
2:07:21 But it has its challenges.
2:07:26 Even just buying dinner can get complicated.
2:07:32 A lot of us foreigners try to learn Chinese, but it's not always easy.
2:07:40 One word can actually have many meanings, depending on the tone you use.
2:07:48 For example, if I say xiao, it means burn,
2:07:54 or xiao, it means little, or xiao, it means laugh.
2:08:06 Use the wrong tone, you could be in big trouble.
2:08:12 MELVIN: It's only us human beings that have developed complex language.
2:08:17 Unlike many other languages, Chinese uses the musical areas of the brain
2:08:22 to extract meaning from all those tones.
2:08:27 And that takes a lot of processing power.
2:08:31 But the really big question is why we have any language at all.
2:08:40 It's partly due to the size of our big brains.
2:08:47 But there could be another factor at play.
2:08:52 One theory is that it was something really tiny.
2:08:57 There's a version of a gene, called FOXP2, that only us humans have.
2:09:04 Take it away, and you'll struggle to talk.
2:09:09 No one knows how we've got this mutation.
2:09:14 (speaking Japanese) But we do know...
2:09:20 (speaking Japanese) ...it gave us more precise
2:09:24 control over our mouth and our tongue muscles.
2:09:29 And that let us make more sophisticated sounds,
2:09:34 helping us turn thoughts into words.
2:09:41 SMITH: Small genetic twists turned us from a bunch of folks who
2:09:45 grunt to a species that can tell xiao from xiao, from xiao.
2:09:53 Sharing ideas, communicating them,
2:09:57 lets us do things that alone would be impossible.
2:10:03 Something pioneers know full well.
2:10:06 (roaring) (music) ROCKY ROBINSON: Okay, let's do it.
2:10:18 I'm getting all kinds— I've wiped it off, but I have all kinds of salt on me.
2:10:22 My shield got covered in salt.
2:10:24 MAN: Turn the water pump off.
2:10:26 ROBINSON: We're here in Bolivia trying
2:10:28 to break the motorcycle world land speed record.
2:10:32 We probably don't have a better opportunity than we have
2:10:35 right now to see just how fast this bike will go.
2:10:38 (music) (music) This is a huge team effort.
2:10:48 We communicate a lot, the team and I.
2:10:52 Communication is a huge advantage.
2:10:57 It takes so many people to come up with a machine of this caliber.
2:11:01 (engine revving) You have all these people doing all this stuff for you,
2:11:08 but once that canopy closes...
2:11:10 MAN: You ready?
2:11:11 ROBINSON: You're all alone.
2:11:15 MAN: 45, hit it, Rocky!
2:11:30 MAN ON RADIO: Full speed, 333.9.
2:11:32 MAN ON RADIO: Roger, six.
2:11:38 ROBINSON: Whoa, whoa, whoa!
2:11:40 There's something wrong with the motor.
2:11:43 MAN ON RADIO: He's coming to a...he's slowing down.
2:11:48 Everything okay down there?
2:11:50 MAN ON RADIO: Seems okay.
2:11:53 ROBINSON: It is going really strong, and it's, whoa, whoa, whoa.
2:11:56 MAN: Main off?
2:11:56 ROBINSON: Yeah.
2:11:57 MAN: Okay.
2:11:58 ROBINSON: Got up to right around 378 miles an hour,
2:12:01 and then the turbo coupler came off.
2:12:06 It's frustrating.
2:12:08 It's a huge team effort, and, you know, we're all trying to reach our goal.
2:12:12 Probably 95% of the time there is something going wrong.
2:12:16 That's why records last so long.
2:12:19 Everything about land speed racing is learning
2:12:21 what's new and how to improve things.
2:12:24 We learn a lot, and I think we can put that to good use in the future.
2:12:31 SMITH: I'm with Rocky on this.
2:12:33 You get knocked down, you get back up again.
2:12:37 Communicating helps you face failure without fear.
2:12:44 But our brains adapt.
2:12:47 So if we lose the ability to communicate, our brain might find a work-around.
2:12:55 It's flexible.
2:12:57 Talk to Leland about it.
2:13:02 MELVIN: During the time of recovery from my hearing accident,
2:13:06 there was a point when I could feel my brain rewiring itself to hear again.
2:13:14 The brain over time can make adjustments to compensate for losses or changes.
2:13:22 And I think that's what happened to me.
2:13:25 My hearing started coming back about three weeks after my accident.
2:13:31 But it took two more years for me to recover properly.
2:13:37 Then finally, the chief medical officer for NASA
2:13:40 pulled out a piece of paper that said,
2:13:45 'You are now cleared to fly in space.' That was
2:13:52 one of the most incredible days of my life.
2:13:56 I never took my brain for granted again.
2:13:58 (crowd cheering) SMITH: With that flexible brain,
2:14:04 we learn, adapt, and problem solve.
2:14:09 Our brains give us language, allowing us to share those lessons with others.
2:14:18 And writing lets us pass on that knowledge through time.
2:14:26 LINENGER: All that human brain power,
2:14:28 all that knowledge through written textbooks,
2:14:32 through calculations, through mathematics.
2:14:35 HOFFMAN: That just led to a huge explosion in the development of civilization.
2:14:43 WHITSON: We can get a lot smarter,
2:14:44 because we can learn a lot more from the previous generations.
2:14:50 SMITH: Humanity is linked together by a network
2:14:53 of minds that spans time and space.
2:14:58 And that's helped us create things of dazzling complexity.
2:15:05 The most complex one we've ever made is floating above us.
2:15:17 MAN ON RADIO: Ignition sequence start.
2:15:19 Five, four, three, two, one.
2:15:27 MELVIN: You're lifting off of the planet.
2:15:31 Feeling 3 Gs on your chest as you're being propelled to the cosmos.
2:15:36 It is one heck of a ride.
2:15:43 MELVIN: After losing the sense of hearing,
2:15:46 it took so many years for me to get to the launchpad,
2:15:49 but it just took a few minutes to get to orbit.
2:15:54 MAN ON RADIO: Good morning, Houston.
2:15:57 MELVIN: We got to space, I saw the planet.
2:15:59 It just blows your mind.
2:16:04 This burst of color.
2:16:08 I've never seen colors that vibrant before.
2:16:15 And I almost had to, like, smack myself to get back to work.
2:16:18 (music) MAN ON RADIO: If you could get the other...
2:16:26 the expedition four crew, that we have them in sight.
2:16:32 MELVIN: And then I saw this little dot out on the horizon.
2:16:37 And we get closer and closer and closer.
2:16:40 (music) The first time I saw the space station flying overhead,
2:16:50 I never knew how complex a vehicle it was.
2:16:55 (music) You know, you could see the intricate design in these modules,
2:17:05 all these things that were envisioned by the human brain.
2:17:10 (music) (music) WHITSON: So, you know,
2:17:20 when you approach it, it's just so beautiful.
2:17:23 It's an amazing, amazing engineering marvel.
2:17:29 HOFFMAN: There's no question that the space station is
2:17:32 the greatest international scientific project that's ever been undertaken.
2:17:38 LINENGER: It's like, wow, this thing is awesome.
2:17:42 And I'm gonna get to live on that thing for four or five months.
2:17:46 (music) MAN ON RADIO:
2:17:52 Coming in now and carrying the camera, mission specialist Leland Melvin.
2:17:57 MAN: How you doing?
2:17:58 MAN: Bull in a china shop, man.
2:17:59 (laughs) MELVIN: Climbing this hill to space was
2:18:10 one of the hardest things I've ever done.
2:18:14 I never imagined myself going deaf,
2:18:17 I never imagined coming back and getting this opportunity after that accident.
2:18:21 (music) And it's really a similar story for all of humankind.
2:18:32 Everything we've achieved as a species is
2:18:36 the product of a lucky chain of accidents.
2:18:43 SMITH: To get here, we needed a planet to congeal out of dust.
2:18:50 In the right place for life to form and mold our world,
2:18:56 allowing us to breathe and grow complex.
2:19:02 We needed to be shielded from our sun, gifted with a moon, and granted seasons.
2:19:13 We needed just enough bombardments and near-annihilations
2:19:17 to let life meander through its twists
2:19:20 and turns and evolve a species with a brain as complex as yours and mine.
2:19:28 (baby cries) (music) (music) MELVIN: When I was on the space station,
2:19:39 looking back at the planet,
2:19:43 it gave me a profound appreciation in what we take for granted.
2:19:54 Humans are a wonderful, extraordinary oddity.
2:19:58 (music) SMITH: Good job, man, great game.
2:20:05 With this blob of Jell-O, these 86 billion neurons,
2:20:13 we've left the planet and looked far,
2:20:17 far out into the universe, trying to unravel the mysteries of the cosmos.
2:20:24 But no matter how far out we look,
2:20:27 the most far-out thing we've ever found is right between our ears.
2:20:32 (music) (music) Next time...
2:20:47 What does it feel like when you finally come back to Earth?
2:20:52 Is there really no place like home?