Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:10,721 --> 00:00:13,921
Brian Cox: Our universe
is a place of infinite variety.
2
00:00:15,921 --> 00:00:18,121
Two trillion galaxies.
3
00:00:22,081 --> 00:00:25,001
Billions and billions of stars.
4
00:00:28,081 --> 00:00:29,841
And countless planets.
5
00:00:30,881 --> 00:00:33,321
Worlds beyond imagination.
6
00:00:37,961 --> 00:00:39,721
The universe is so vast,
7
00:00:39,801 --> 00:00:43,201
so incomprehensible, so terrifying,
8
00:00:43,281 --> 00:00:45,241
that I think it's quite natural
for us to choose
9
00:00:45,321 --> 00:00:48,161
to live out our lives
completely oblivious to it.
10
00:00:51,921 --> 00:00:56,201
Perhaps that's why there's a sense
of relief that rises with the dawn.
11
00:00:56,281 --> 00:01:01,041
The brightening sky hides the stars
and the questions that they pose.
12
00:01:03,161 --> 00:01:06,361
A fter all,
they are the biggest questions.
13
00:01:09,321 --> 00:01:11,161
How did the universe come to be?
14
00:01:12,641 --> 00:01:13,761
Why are we here?
15
00:01:15,361 --> 00:01:17,121
And how will it all end?
16
00:01:23,481 --> 00:01:25,321
We have to face those questions
17
00:01:25,401 --> 00:01:30,041
if we 're ever to acquire
a truly deep understanding of ourselves.
18
00:01:30,121 --> 00:01:33,201
You see, astronomy challenges us.
19
00:01:33,281 --> 00:01:36,841
From one perspective,
we're just grains of sand adrift
20
00:01:36,921 --> 00:01:39,801
in an infinite and indifferent ocean.
21
00:01:39,881 --> 00:01:44,601
But from another perspective, we are
nature's most magnificent creation.
22
00:01:44,681 --> 00:01:49,281
Collections of atoms that can think
and wonder about the universe
23
00:01:49,361 --> 00:01:52,081
and choose to explore it.
24
00:01:54,121 --> 00:01:58,161
In distinct voices: Five, four,
three, two, one.
25
00:01:58,521 --> 00:02:00,921
We have lift-off. All systems go.
26
00:02:06,641 --> 00:02:11,041
Cox: In our quest for answers,
we 're venturing ever further from home,
27
00:02:11,641 --> 00:02:13,321
far beyond the planets...
28
00:02:16,801 --> 00:02:18,921
And out to the stars.
29
00:02:22,601 --> 00:02:27,081
Our spacecraft are sending back
a stream of extraordinary revelations.
30
00:02:29,441 --> 00:02:31,841
Visions of alien worlds...
31
00:02:34,281 --> 00:02:37,361
With the ingredients to create life.
32
00:02:44,481 --> 00:02:46,681
We've seen galaxies collide,
33
00:02:51,161 --> 00:02:54,241
black holes devouring star systems.
34
00:02:57,521 --> 00:03:02,041
And we may have glimpsed
the origin of the cosmos itself.
35
00:03:04,921 --> 00:03:08,761
With every new observation,
with every new piece of knowledge,
36
00:03:08,841 --> 00:03:12,681
there is the opportunity to acquire
a deeper understanding.
37
00:03:12,761 --> 00:03:15,841
And, as we answer
question after question
38
00:03:15,921 --> 00:03:18,481
we get ever closer to being able to tell
39
00:03:18,561 --> 00:03:22,561
what is surely
the greatest story ever told.
40
00:04:09,241 --> 00:04:11,881
Man over radio:
Na sa '5 Parker solar probe,
41
00:04:11,961 --> 00:04:13,961
a daring mission to shed light
42
00:04:15,481 --> 00:04:19,201
on the mysteries of our closest star.
43
00:04:29,401 --> 00:04:34,641
Eugene Parker: This is a journey
into ne ver-ne ver land you might say.
44
00:04:44,161 --> 00:04:50,681
Cox: NASA's Parker solar probe is
the first spacecraft to touch a star.
45
00:05:15,401 --> 00:05:18,841
It's designed to fly
through the sun's atmosphere,
46
00:05:21,241 --> 00:05:25,081
bra ving temperatures
no spacecraft has ever endured.
47
00:05:54,361 --> 00:05:58,241
The Parker solar probe is
allowing us to know our star
48
00:05:58,881 --> 00:06:00,481
as we've never known it before.
49
00:06:05,641 --> 00:06:10,401
And it's also helping us
to tell the story of all the stars.
50
00:06:20,081 --> 00:06:25,041
Our sun is from a long line of stars
dating back to the dawn of time.
51
00:06:27,321 --> 00:06:29,361
From fierce blue giants
52
00:06:30,961 --> 00:06:33,161
which first lit up the universe,
53
00:06:36,241 --> 00:06:38,081
to later generations,
54
00:06:40,521 --> 00:06:44,161
whose deaths enriched the cosmos
with precious elements,
55
00:06:49,161 --> 00:06:51,481
the building blocks of our solar system,
56
00:06:58,801 --> 00:07:04,361
And allowed our sun to create the thing
which brings meaning to the cosmos.
57
00:07:12,121 --> 00:07:13,361
Life.
58
00:07:14,681 --> 00:07:17,081
You and me.
59
00:07:57,001 --> 00:08:00,081
We have
a strange relationship with the stars,
60
00:08:00,161 --> 00:08:03,481
somewhere between awe and indifference.
61
00:08:05,161 --> 00:08:07,801
I think we take our star,
the sun, for granted,
62
00:08:07,881 --> 00:08:09,801
partly because of its predictability.
63
00:08:09,881 --> 00:08:13,441
Every day it rises in the east
and sets in the west,
64
00:08:15,601 --> 00:08:19,441
without any help or reverence from us.
65
00:08:24,041 --> 00:08:27,161
But many ancient cultures deified
the sun.
66
00:08:27,921 --> 00:08:29,681
They treated it as a god
67
00:08:30,481 --> 00:08:34,841
and the sun gods were creators
and destroyers of worlds.
68
00:08:35,481 --> 00:08:37,041
So which is it?
69
00:08:38,081 --> 00:08:43,641
Well, I think that the modern story
of the stars as told by science,
70
00:08:43,721 --> 00:08:46,401
which is indisputably an epic story
71
00:08:46,481 --> 00:08:50,921
stretching back over 13 billion years
to the origin of the universe,
72
00:08:51,001 --> 00:08:54,561
places them firmly
in the realm of the gods.
73
00:09:06,161 --> 00:09:09,401
If we want to understand
where these gods came from...
74
00:09:11,521 --> 00:09:12,961
We have to go back...
75
00:09:18,481 --> 00:09:21,081
To a time before the stars.
76
00:09:50,561 --> 00:09:54,801
In the beginning the universe was dark.
77
00:10:00,721 --> 00:10:03,041
But it was not empty.
78
00:10:07,281 --> 00:10:10,081
Something was lurking in the void,
79
00:10:13,321 --> 00:10:15,441
stretching out tendrils.
80
00:10:37,761 --> 00:10:41,601
The cosmic web grew
to become a vast structure,
81
00:10:46,881 --> 00:10:49,161
Criss-crossing the entire universe.
82
00:10:54,521 --> 00:10:58,521
It was formed by interlocking filaments
of dark matter,
83
00:11:04,161 --> 00:11:06,881
And it was at the places
where these filaments met,
84
00:11:10,081 --> 00:11:11,641
the intersections,
85
00:11:18,121 --> 00:11:24,521
That the first stars,
our sun's earliest ancestors, were born.
86
00:12:01,081 --> 00:12:04,201
The cosmic web is
the scaffolding of the universe,
87
00:12:05,401 --> 00:12:09,521
the vast and intricate structure
that spans the void.
88
00:12:15,081 --> 00:12:18,121
The web is made
primarily out of dark matter,
89
00:12:18,201 --> 00:12:22,001
a mysterious substance
that dominates the universe,
90
00:12:22,081 --> 00:12:24,721
although we don't know what it is.
91
00:12:24,801 --> 00:12:26,801
It's one of the great mysteries
in modern physics.
92
00:12:26,881 --> 00:12:32,601
It's probably some kind of particle
that interacts very weakly with itself
93
00:12:32,681 --> 00:12:34,321
and with light.
94
00:12:34,401 --> 00:12:36,081
If it doesn't interact with light,
95
00:12:36,161 --> 00:12:38,441
we can't see it, which is
why it's called dark matter.
96
00:12:40,721 --> 00:12:45,041
But it does influence the universe
through its gravity.
97
00:12:49,801 --> 00:12:52,481
It was in the dark heart
of the cosmic web
98
00:12:53,121 --> 00:12:56,361
that gravity began to sculpt
the early universe,
99
00:13:00,201 --> 00:13:03,281
drawing together
the two simplest elements,
100
00:13:03,361 --> 00:13:05,401
hydrogen and helium.
101
00:13:07,321 --> 00:13:11,081
The raw material
for the very first stars.
102
00:13:14,441 --> 00:13:18,601
Hydrogen gas clings
to the filaments of the web,
103
00:13:18,721 --> 00:13:21,001
attracted there
by the gravitational pull
104
00:13:21,081 --> 00:13:22,441
of the dark matter.
105
00:13:23,801 --> 00:13:26,281
And where those filaments cross,
106
00:13:26,361 --> 00:13:30,761
the gas can become dense enough
to collapse under its own gravity
107
00:13:30,841 --> 00:13:35,521
to form great clusters of galaxies,
each filled with billions of stars.
108
00:13:52,361 --> 00:13:55,361
The universe was
approaching a turning point.
109
00:13:57,281 --> 00:13:59,961
Hydrogen and helium poured
into the regions
110
00:14:00,041 --> 00:14:01,721
where the filaments crossed,
111
00:14:04,521 --> 00:14:07,001
gathering into ever denser clouds.
112
00:14:12,001 --> 00:14:14,281
Gra vity asserted its grip,
113
00:14:17,521 --> 00:14:20,441
and the clouds of gas began to collapse,
114
00:14:25,401 --> 00:14:28,001
becoming denser and denser.
115
00:14:31,401 --> 00:14:33,761
And in the densest regions,
116
00:14:33,841 --> 00:14:35,801
the gas became so hot...
117
00:14:38,321 --> 00:14:41,081
That nuclear fusion reactions began.
118
00:15:03,001 --> 00:15:04,721
And out of maelstrom,
119
00:15:05,961 --> 00:15:08,841
the first gods emerged,
120
00:15:11,681 --> 00:15:13,241
and there was light.
121
00:16:00,361 --> 00:16:02,961
The stars illuminate the universe,
122
00:16:03,921 --> 00:16:07,681
but that is the least interesting thing
that they do.
123
00:16:09,561 --> 00:16:11,401
The thing that makes
the universe interesting,
124
00:16:11,481 --> 00:16:17,641
that brings meaning to the universe is
that, life. You and me.
125
00:16:17,721 --> 00:16:20,641
And life is just chemistry.
126
00:16:20,721 --> 00:16:24,561
And chemistry requires
complex chemical elements.
127
00:16:24,641 --> 00:16:27,721
The only thing that existed
in the universe before the stars
128
00:16:27,801 --> 00:16:29,801
was hydrogen and helium.
129
00:16:29,881 --> 00:16:33,361
Life requires carbon
and oxygen and iron.
130
00:16:33,441 --> 00:16:37,441
All those things were made
in a process called nuclear fusion
131
00:16:37,521 --> 00:16:39,201
in the cores of stars,
132
00:16:39,281 --> 00:16:43,921
or even the heavier elements,
like gold, in the collisions of stars.
133
00:16:44,001 --> 00:16:48,881
50, without the stars,
the universe would be uninteresting.
134
00:16:48,961 --> 00:16:50,721
It would be meaningless.
135
00:16:50,801 --> 00:16:54,321
It would be just an infinite box of gas.
136
00:17:07,041 --> 00:17:09,281
The first stars were monsters.
137
00:17:17,961 --> 00:17:20,801
Hundreds of times as massive as our sun.
138
00:17:25,801 --> 00:17:30,001
They burnt with such ferocity
that they shone blue,
139
00:17:33,961 --> 00:17:38,561
with surface temperatures
in excess of 700, 000 degrees.
140
00:17:42,641 --> 00:17:45,841
They were the largest stars ever
to have lived.
141
00:17:47,681 --> 00:17:50,401
I/iolent and volatile giants.
142
00:18:00,681 --> 00:18:03,401
A star is essentially a balancing act.
143
00:18:03,481 --> 00:18:07,201
The force of gravity is
constantly trying to collapse it,
144
00:18:07,281 --> 00:18:09,481
and that pushes its ingredients,
145
00:18:09,561 --> 00:18:13,641
primarily hydrogen, single protons,
closer and closer together.
146
00:18:14,121 --> 00:18:17,121
Now, when those protons
get close enough together,
147
00:18:17,201 --> 00:18:19,521
another of the fundamental forces
of nature,
148
00:18:19,601 --> 00:18:22,481
the strong nuclear force, takes over,
149
00:18:22,561 --> 00:18:24,641
and it can stick the protons together.
150
00:18:24,721 --> 00:18:29,801
That releases energy which creates
a pressure which holds the star up.
151
00:18:29,881 --> 00:18:34,121
Now the more massive the star,
the stronger the inward pull of gravity
152
00:18:34,201 --> 00:18:37,881
and the more energy has to be released
to maintain the balance,
153
00:18:37,961 --> 00:18:40,881
and so the faster
the ingredients are used up.
154
00:19:01,401 --> 00:19:04,721
These giant stars were
in a struggle for survival,
155
00:19:06,281 --> 00:19:09,321
fighting the relentless pull of gra vity,
156
00:19:13,881 --> 00:19:17,241
consuming more and more hydrogen fuel
157
00:19:17,321 --> 00:19:20,281
to maintain
their precarious equilibrium.
158
00:19:37,361 --> 00:19:40,281
For most of its life,
a star burns hydrogen,
159
00:19:40,361 --> 00:19:43,561
the simplest chemical element
with one proton in its nucleus,
160
00:19:44,241 --> 00:19:46,641
into helium with two protons.
161
00:19:47,721 --> 00:19:50,041
Now, when it runs out
of hydrogen in the core,
162
00:19:50,121 --> 00:19:53,001
the core starts to collapse and heat up,
163
00:19:53,081 --> 00:19:57,961
and the star responds by building
ever more complex elements.
164
00:19:58,041 --> 00:20:02,081
So it makes carbon with six protons
and oxygen with eight protons,
165
00:20:02,161 --> 00:20:04,921
releasing more
and more energy as it goes.
166
00:20:08,081 --> 00:20:11,521
But when the star has
assembled iron in its core,
167
00:20:11,601 --> 00:20:14,161
with 26 protons in its nucleus,
168
00:20:14,241 --> 00:20:17,001
no more energy can be released.
169
00:20:17,121 --> 00:20:20,401
The star loses
its battle against gravity.
170
00:20:20,481 --> 00:20:25,641
It collapses
and in a final moment of creation,
171
00:20:25,761 --> 00:20:28,561
salvaged if you like,
from its destruction,
172
00:20:28,641 --> 00:20:32,481
it distributes those newly minted
heavy chemical elements
173
00:20:32,561 --> 00:20:34,721
out into the universe.
174
00:20:49,841 --> 00:20:53,361
Imagine we could journey back in time
175
00:20:53,441 --> 00:20:58,681
and watch the first star live out
its brief luminous life.
176
00:21:19,361 --> 00:21:24,881
After only a million years
the star used up all of its fuel.
177
00:21:36,001 --> 00:21:37,801
The core collapsed.
178
00:21:52,921 --> 00:21:55,001
The star imploded.
179
00:22:07,441 --> 00:22:09,041
And then rebounded...
180
00:22:10,241 --> 00:22:12,121
In a colossal explosion.
181
00:22:13,601 --> 00:22:15,001
A supernova.
182
00:22:37,281 --> 00:22:41,801
In death, the first stars began
to transform the cosmos,
183
00:22:45,361 --> 00:22:48,761
enriching the ocean
of hydrogen and helium
184
00:22:48,841 --> 00:22:52,561
which filled the universe
with heavy elements...
185
00:22:55,041 --> 00:22:59,281
To build new generations
of more complex stars.
186
00:23:08,081 --> 00:23:11,681
Over time,
these elements gathered together,
187
00:23:20,281 --> 00:23:24,041
Creating rich clouds of gas and dust.
188
00:23:33,281 --> 00:23:38,361
Nurseries where new generations
of stars were born.
189
00:23:44,761 --> 00:23:48,841
And not just stars,
but families of stars.
190
00:23:51,201 --> 00:23:52,841
The first galaxies.
191
00:24:00,481 --> 00:24:01,681
And around this time,
192
00:24:02,561 --> 00:24:09,161
some of the earliest star systems
formed in our own galaxy, the milky way.
193
00:24:20,281 --> 00:24:23,961
A new age of complexity was
dawning in the universe.
194
00:24:26,721 --> 00:24:29,561
Now, there were stars
of different sizes,
195
00:24:35,641 --> 00:24:37,161
And different colours.
196
00:24:51,321 --> 00:24:55,321
And crucially new bodies had appeared.
197
00:25:04,401 --> 00:25:05,761
Planets.
198
00:25:07,801 --> 00:25:14,201
Places where the rich chemical elements
built by previous generations of stars
199
00:25:14,761 --> 00:25:17,841
could finally find a home.
200
00:25:33,601 --> 00:25:35,921
Countless billions of stars
have come and gone
201
00:25:36,001 --> 00:25:39,841
since those first giants
illuminated the darkness.
202
00:25:39,921 --> 00:25:42,281
Each enriching the universe
203
00:25:42,361 --> 00:25:45,561
with the material
out of which the next generation formed.
204
00:25:46,241 --> 00:25:50,241
Blue stars and white stars,
single stars, double stars,
205
00:25:50,321 --> 00:25:53,761
even triple star systems orbiting
around each other.
206
00:25:57,081 --> 00:25:59,001
The conditions were now right
207
00:25:59,081 --> 00:26:02,121
for those stars to drive the universe
208
00:26:02,201 --> 00:26:05,401
into a new and profound age
of complexity.
209
00:26:35,081 --> 00:26:39,521
Our sun was formed from the ashes
of generations of ancestors.
210
00:26:54,481 --> 00:27:00,281
Just one small star in a galaxy
of billions of brilliant gods.
211
00:27:09,681 --> 00:27:14,561
For the first million years of its life,
the sun was virtually alone,
212
00:27:16,881 --> 00:27:20,281
wreathed in clouds of gas and dust.
213
00:27:23,521 --> 00:27:26,081
The dust slowly clumped together...
214
00:27:30,681 --> 00:27:33,281
Forming clusters the size of pebbles.
215
00:27:36,601 --> 00:27:38,441
Then, boulders.
216
00:27:45,121 --> 00:27:46,601
And finally...
217
00:27:48,561 --> 00:27:49,801
Planets.
218
00:27:56,161 --> 00:27:58,561
But the planets were lifeless rocks.
219
00:28:06,081 --> 00:28:11,841
Only the sun had the power
to turn them into worlds.
220
00:28:19,081 --> 00:28:21,721
Some were too faraway from the sun.
221
00:28:35,001 --> 00:28:36,441
Ice giants,
222
00:28:37,801 --> 00:28:42,121
frozen, seemingly into infertility.
223
00:28:46,961 --> 00:28:49,641
Others formed too close to the sun,
224
00:28:52,601 --> 00:28:55,361
seared by a relentless light.
225
00:28:58,361 --> 00:29:01,441
They became scorched desert worlds.
226
00:29:05,001 --> 00:29:08,041
But there was a planet
in the sun's family
227
00:29:09,961 --> 00:29:15,201
that, quite by chance, formed
neither too close nor too far away.
228
00:29:21,841 --> 00:29:27,641
An arcadia, where our star could
breathe life into dust.
229
00:29:52,561 --> 00:29:56,441
The planets are just the leftovers
from the formation of stars.
230
00:29:56,521 --> 00:29:58,841
Debris, if you like.
231
00:30:00,201 --> 00:30:04,441
They're just little specks orbiting
around those magnificent flames.
232
00:30:06,761 --> 00:30:10,321
But the planets are also
the places in the universe
233
00:30:10,401 --> 00:30:13,681
where gravity has concentrated
the heavy elements built
234
00:30:13,761 --> 00:30:16,481
by previous generations of stars.
235
00:30:16,561 --> 00:30:21,441
And that makes the planets the canvas
on which the stars can create.
236
00:30:24,241 --> 00:30:27,761
"The canvas on which the stars can
create." What do I mean by that?
237
00:30:27,841 --> 00:30:29,361
Well, just look around.
238
00:30:29,441 --> 00:30:32,521
Everywhere you look on earth
there is complexity.
239
00:30:32,601 --> 00:30:37,121
Not only mountains and rivers,
but living things, animals and plants,
240
00:30:37,201 --> 00:30:39,801
human beings, human civilisation,
241
00:30:39,881 --> 00:30:43,921
the most complex thing we know of
anywhere in the universe.
242
00:30:44,001 --> 00:30:45,961
So, you have to ask yourself
243
00:30:46,041 --> 00:30:49,641
how can it be
that such complexity can emerge
244
00:30:49,721 --> 00:30:52,561
completely naturally in the universe?
245
00:30:57,601 --> 00:31:02,081
Well, the answer, in fact, was
known in the 79th century
246
00:31:02,161 --> 00:31:04,881
and it comes from the science
of thermodynamics.
247
00:31:07,801 --> 00:31:08,961
In the 19th century,
248
00:31:09,041 --> 00:31:11,481
people were interested
in the efficiency of steam engines,
249
00:31:11,561 --> 00:31:16,041
and steam engines are, after all,
the machines that powered the factories
250
00:31:16,121 --> 00:31:19,601
that allowed people to build
increasingly complex things.
251
00:31:20,081 --> 00:31:24,161
And it turns out that the only thing
that matters for a steam engine,
252
00:31:24,241 --> 00:31:26,321
the thing
that determines its efficiency,
253
00:31:26,401 --> 00:31:30,001
the thing that allows it
to do work and build things
254
00:31:30,081 --> 00:31:33,601
is the temperature difference
between the fire,
255
00:31:33,681 --> 00:31:36,521
the furnace
at the heart of the steam engine,
256
00:31:36,601 --> 00:31:39,801
and the cold environment surrounding it.
257
00:31:41,961 --> 00:31:46,801
In the universe, the stars are
hot spots in a cold sky.
258
00:31:46,881 --> 00:31:52,081
We are sitting, in a very real sense,
inside a giant steam engine,
259
00:31:52,161 --> 00:31:54,681
powered by the furnace of the sun.
260
00:31:56,361 --> 00:31:58,281
And it's in that sense
261
00:31:58,361 --> 00:32:03,481
that the stars are the creators
of complexity in the universe.
262
00:32:07,521 --> 00:32:11,161
But creating complexity is a subtle art.
263
00:32:14,121 --> 00:32:19,561
You need an engine, in this case a star,
that's not too wild and flashy.
264
00:32:24,441 --> 00:32:29,121
A star which is
consistent enough for long enough
265
00:32:29,201 --> 00:32:31,321
to kindle the sparks of life,
266
00:32:37,241 --> 00:32:41,401
And allow those sparks
to flicker and flourish.
267
00:32:54,361 --> 00:32:59,761
The most important property of a star,
if it's to nurture a civilisation...
268
00:33:01,801 --> 00:33:05,081
Is magnificent dependability.
269
00:33:30,041 --> 00:33:33,921
No one knows exactly
how life on earth emerged.
270
00:33:41,121 --> 00:33:44,721
But what we do know is
that at some point
271
00:33:44,801 --> 00:33:50,241
primitive cells living in the ocean
began using the sun's energy
272
00:33:50,321 --> 00:33:53,641
to power life-giving chemical reactions.
273
00:33:56,241 --> 00:34:01,441
These cells formed a bridge
between earth and sun.
274
00:34:03,481 --> 00:34:07,761
Delicate engines
which harness the fires of our star,
275
00:34:09,481 --> 00:34:15,241
using sunlight to turn
carbon dioxide and water into food.
276
00:34:21,921 --> 00:34:28,561
This process, known as photosynthesis,
unleashed the sun's creative power,
277
00:34:42,761 --> 00:34:46,041
And drove the evolution of complexity.
278
00:34:54,721 --> 00:34:56,641
From primitive bacteria,
279
00:34:57,681 --> 00:35:00,481
to plants and trees...
280
00:35:12,841 --> 00:35:16,881
And ultimately, to you and me.
281
00:35:20,841 --> 00:35:22,561
You know, photosynthesis is a process
282
00:35:22,641 --> 00:35:25,121
that's very easy to describe in words.
283
00:35:25,681 --> 00:35:27,641
The plants take energy from the sun,
284
00:35:28,761 --> 00:35:32,441
then use it to react carbon dioxide
and water together
285
00:35:32,521 --> 00:35:35,921
to make sugars
and a waste product, oxygen.
286
00:35:36,001 --> 00:35:39,361
Really easy to say.
Very difficult to do.
287
00:35:39,441 --> 00:35:42,921
There's a part
of that photosynthetic machinery
288
00:35:43,001 --> 00:35:44,641
in everything you see here.
289
00:35:44,721 --> 00:35:47,601
Every plant on the planet has
got photosystem ii.
290
00:35:47,681 --> 00:35:52,841
It's comprised of 46, 630 atoms
291
00:35:52,921 --> 00:35:56,481
all working together
in an intricate machine.
292
00:35:56,601 --> 00:36:00,441
Very efficient.
It took billions of years of evolution.
293
00:36:01,081 --> 00:36:02,441
Then we eat the plants,
294
00:36:02,521 --> 00:36:05,121
or we eat something
that's eaten the plants
295
00:36:05,201 --> 00:36:07,761
and we do the reverse reaction.
296
00:36:07,841 --> 00:36:12,441
We take those sugars and we breathe in
that waste product, oxygen.
297
00:36:12,521 --> 00:36:14,681
React them together,
release a bit of energy,
298
00:36:14,761 --> 00:36:17,201
a bit of the stored sunlight
if you like,
299
00:36:17,281 --> 00:36:22,921
and we use that energy to maintain
our structure, to grow, to live.
300
00:36:30,521 --> 00:36:34,121
T rillions of stars have existed
since the universe began.
301
00:36:39,121 --> 00:36:43,681
But ours has nurtured
that most miraculous thing,
302
00:36:45,281 --> 00:36:46,441
life.
303
00:36:49,961 --> 00:36:54,481
And that makes the sun
a truly remarkable star.
304
00:37:03,161 --> 00:37:06,041
That is the only star
we know of anywhere
305
00:37:06,121 --> 00:37:10,721
where there are collections of atoms
in orbit around it, you and me,
306
00:37:10,801 --> 00:37:15,081
that have named it the sun. Our sun.
307
00:37:15,161 --> 00:37:18,881
We worshipped it, deified it
since the dawn of history.
308
00:37:18,961 --> 00:37:22,201
In fact, it's been argued
that the sun lies at the foundation
309
00:37:22,281 --> 00:37:26,681
of all religion, and there may be
some truth in that.
310
00:37:26,761 --> 00:37:29,801
In fact, I think
there is a deep truth in that
311
00:37:29,881 --> 00:37:32,521
because we all owe our existence,
312
00:37:32,601 --> 00:37:37,001
this brief time we have
in the universe to that star.
313
00:37:37,081 --> 00:37:40,401
In fact, in a deeper sense
to all the stars.
314
00:37:40,481 --> 00:37:45,801
We don't need to invent
imaginary gods to explain the universe.
315
00:37:45,881 --> 00:37:48,721
We can replace them with the real thing.
316
00:38:02,601 --> 00:38:04,161
Everyone we love.
317
00:38:09,881 --> 00:38:12,121
Everything we value.
318
00:38:15,041 --> 00:38:19,721
Our supreme accomplishments
as a civilisation...
319
00:38:23,481 --> 00:38:26,401
Were created and crafted...
320
00:38:30,081 --> 00:38:31,361
By stars.
321
00:38:51,241 --> 00:38:55,481
There are over 200 billion stars
in our galaxy.
322
00:39:00,521 --> 00:39:05,081
And there are two trillion galaxies
in the observable universe.
323
00:39:14,481 --> 00:39:16,841
We 're living in the age of stars.
324
00:39:27,761 --> 00:39:31,121
An era of light and life in the cosmos.
325
00:39:37,281 --> 00:39:39,921
From our fleeting human perspective,
326
00:39:40,721 --> 00:39:42,801
stars seem eternal.
327
00:40:02,681 --> 00:40:06,521
But even gods are not immortal.
328
00:40:10,841 --> 00:40:12,721
Where there is light,
329
00:40:15,321 --> 00:40:16,761
there is darkness.
330
00:40:21,881 --> 00:40:23,641
Stars are creators,
331
00:40:29,561 --> 00:40:32,921
But they can be jealous guardians
of their creations.
332
00:40:38,321 --> 00:40:43,361
Many smaller stars don't die
in spectacular explosions.
333
00:40:45,201 --> 00:40:49,801
Instead, they slowly fade away.
334
00:40:51,681 --> 00:40:55,601
They hang on
to the precious elements they made,
335
00:40:57,721 --> 00:40:59,481
becoming fossil stars.
336
00:41:04,041 --> 00:41:06,721
And as more fossils litter the universe,
337
00:41:09,401 --> 00:41:13,041
more life giving elements
remain locked away,
338
00:41:15,721 --> 00:41:17,961
starving the cosmos
339
00:41:18,041 --> 00:41:21,961
of the material needed to make
new generations of stars.
340
00:41:39,881 --> 00:41:42,841
The age of stars may seem infinite,
341
00:41:45,121 --> 00:41:46,641
but it had a beginning,
342
00:41:48,401 --> 00:41:50,881
and it will also have an end.
343
00:41:54,681 --> 00:41:57,601
Imagine a timeline of the universe
344
00:41:57,681 --> 00:42:00,641
and imagine that this is
the origin of the universe,
345
00:42:00,721 --> 00:42:03,521
the big bang 13.8 billion years ago.
346
00:42:04,241 --> 00:42:08,041
After 100 million years or so,
the first stars formed.
347
00:42:08,121 --> 00:42:13,121
On this scale, one centimetre is
about 20 million years.
348
00:42:13,201 --> 00:42:17,801
After four billion years the peak rate
of star formation occurred.
349
00:42:17,881 --> 00:42:21,361
The maximum number
of new stars were born.
350
00:42:21,441 --> 00:42:26,121
After nine billion years,
our sun was born.
351
00:42:26,961 --> 00:42:31,561
And, today, we stand
13.8 billion years later,
352
00:42:31,641 --> 00:42:34,681
about halfway through
the lifetime of our sun.
353
00:42:35,601 --> 00:42:38,161
Now, in about five billion years' time,
354
00:42:38,241 --> 00:42:41,601
our sun will die
but new stars will be born,
355
00:42:42,201 --> 00:42:44,601
and many of the older stars
in the universe,
356
00:42:44,681 --> 00:42:47,801
the smaller stars, will
continue to shine.
357
00:42:47,881 --> 00:42:52,441
In fact, we think that the last star
will cease to shine,
358
00:42:52,521 --> 00:42:57,121
the universe will go dark,
in around ten trillion years.
359
00:42:58,761 --> 00:43:01,761
On this scale,
that's about 5000 metres away
360
00:43:01,841 --> 00:43:03,521
from the big bang.
361
00:43:04,041 --> 00:43:05,601
But that's not the end of the universe.
362
00:43:05,681 --> 00:43:11,081
As far as we know, the universe will
continue expanding forever.
363
00:43:11,601 --> 00:43:16,761
And so, the age of starlight is
the briefest moment of time
364
00:43:16,841 --> 00:43:19,001
in the infinite history of the universe.
365
00:43:19,081 --> 00:43:24,481
The age of darkness will go on
and on and on.
366
00:43:31,161 --> 00:43:34,121
Stars won't just disappear, of course.
367
00:43:37,041 --> 00:43:39,921
They'll be here for aeons to come.
368
00:43:43,481 --> 00:43:45,721
But, over time,
369
00:43:45,801 --> 00:43:51,721
the universe will grow darker,
colder and emptier.
370
00:44:02,161 --> 00:44:03,921
There are stars around today
371
00:44:04,001 --> 00:44:07,801
that existed close to the beginning
of the age of stars.
372
00:44:16,481 --> 00:44:20,281
And some of them will
also witness the end.
373
00:44:24,921 --> 00:44:28,161
They're the longest-lived stars
in the universe.
374
00:44:30,081 --> 00:44:31,361
Red dwarfs.
375
00:44:39,961 --> 00:44:42,721
T rappist-7 is one of these ancients.
376
00:44:50,001 --> 00:44:53,281
It's already more than
seven billion years old.
377
00:44:54,721 --> 00:44:56,881
Almost twice as old as our sun.
378
00:45:06,521 --> 00:45:09,921
But only around a tenth of the size,
379
00:45:15,921 --> 00:45:18,761
And less than one percent as bright.
380
00:45:22,721 --> 00:45:24,361
It's a cool star.
381
00:45:26,161 --> 00:45:27,681
Slow burning.
382
00:45:33,721 --> 00:45:36,801
And that is the secret of its longevity.
383
00:45:41,881 --> 00:45:43,601
Because they burn slowly,
384
00:45:44,961 --> 00:45:48,081
red dwarfs live for a very long time,
385
00:45:54,881 --> 00:45:58,241
Far longer than any other star.
386
00:46:04,121 --> 00:46:07,681
Like the sun, trappist-7 has
its own planets.
387
00:46:09,841 --> 00:46:11,881
Seven rocky worlds,
388
00:46:14,761 --> 00:46:17,201
each roughly the size of earth.
389
00:46:21,681 --> 00:46:26,081
Some may have atmospheres,
and even oceans.
390
00:46:35,321 --> 00:46:37,841
But there the similarity ends,
391
00:46:49,801 --> 00:46:52,201
Because these are strange worlds.
392
00:46:55,241 --> 00:46:58,961
Every one of these planets
is locked in its orbit,
393
00:47:01,081 --> 00:47:03,761
one side facing t rappist-7,
394
00:47:05,761 --> 00:47:07,681
the other side frozen,
395
00:47:07,761 --> 00:47:11,761
permanently exposed
to the cold void of space.
396
00:47:24,041 --> 00:47:27,881
If you could stand on the surface
of one of these ancient worlds,
397
00:47:34,521 --> 00:47:37,001
As the aeons passed,
398
00:47:41,161 --> 00:47:46,041
you could watch the future
of the cosmos slowly unfold.
399
00:47:56,241 --> 00:48:01,241
And one day,
five billion years from now,
400
00:48:03,721 --> 00:48:07,081
you 'd see our sun flicker
401
00:48:08,361 --> 00:48:11,721
and fade away forever.
402
00:48:40,121 --> 00:48:43,241
The death of our sun will
probably go unremarked.
403
00:48:46,001 --> 00:48:47,961
I doubt that we'll be around to see it.
404
00:48:48,041 --> 00:48:51,921
Maybe some alien astronomer,
on a world far away
405
00:48:52,001 --> 00:48:53,801
across the milky way, will see it
406
00:48:53,881 --> 00:48:55,961
through the end of their telescope
407
00:48:56,041 --> 00:48:57,941
but I don't think
they'll give it a second thought.
408
00:48:57,961 --> 00:49:02,641
I mean, we've seen hundreds of stars die
and we don't give them a second thought.
409
00:49:02,721 --> 00:49:07,641
But, I think the death of our sun will
matter here, locally,
410
00:49:07,721 --> 00:49:10,481
in this little corner of the galaxy,
411
00:49:10,561 --> 00:49:13,481
because it will Mark the end
of a glorious time
412
00:49:13,561 --> 00:49:15,001
in the history of our galaxy,
413
00:49:15,161 --> 00:49:19,041
where meaning,
where science and literature
414
00:49:19,121 --> 00:49:22,321
and art and poetry
and music existed here.
415
00:49:22,961 --> 00:49:24,241
And that does matter.
416
00:49:28,241 --> 00:49:30,521
Why does meaning have to be eternal?
417
00:49:30,601 --> 00:49:34,841
It's the fragility of our lives
that makes them valuable.
418
00:49:40,201 --> 00:49:43,561
I think the wonderful thing is
that our star has
419
00:49:43,641 --> 00:49:47,881
taken the laws of nature,
here on this planet,
420
00:49:47,961 --> 00:49:51,681
and crafted such
a magnificent expression of them.
421
00:49:51,761 --> 00:49:53,441
You and me,
422
00:49:54,961 --> 00:49:56,201
and all this.
423
00:50:24,681 --> 00:50:29,841
Stars like trappist-7 will linger on
long after the death of our sun.
424
00:50:37,961 --> 00:50:41,401
We will never know the name
of the last star.
425
00:50:49,081 --> 00:50:50,481
But we know
426
00:50:51,521 --> 00:50:53,681
that the last star to shine
427
00:50:55,561 --> 00:50:57,001
will be a red dwarf.
428
00:51:04,241 --> 00:51:06,841
The last star will slowly cool...
429
00:51:10,801 --> 00:51:12,081
And fade away.
430
00:51:26,081 --> 00:51:28,681
With its passing
the universe will become,
431
00:51:29,521 --> 00:51:32,241
once again, a void,
432
00:51:37,321 --> 00:51:38,721
Without light,
433
00:51:41,121 --> 00:51:42,241
or life,
434
00:51:45,641 --> 00:51:46,801
or meaning.
435
00:52:05,721 --> 00:52:07,681
The stars illuminate the universe
436
00:52:07,761 --> 00:52:10,201
and create
its most intricate structures.
437
00:52:14,601 --> 00:52:17,281
And one day, they will all be gone.
438
00:52:21,361 --> 00:52:24,961
The stars are gods,
but the y're mortal gods.
439
00:52:25,361 --> 00:52:28,601
And, when that time comes
and the last stars have faded,
440
00:52:28,681 --> 00:52:34,321
and all possibility of life and meaning
in the universe has faded with them,
441
00:52:34,401 --> 00:52:37,521
they will have left
the most profound legacy.
442
00:52:37,601 --> 00:52:42,041
Because, for a moment
in the long history of the universe,
443
00:52:42,121 --> 00:52:45,121
the stars illuminated the dark,
444
00:52:45,201 --> 00:52:48,281
and allowed us to illuminate it, too.
445
00:53:22,561 --> 00:53:26,921
Raman prinja: We want to study the sun
because it teaches us a lot about stars.
446
00:53:27,001 --> 00:53:30,961
It teaches us a lot about all the other
millions and billions of stars
447
00:53:31,041 --> 00:53:32,681
in our galaxy and beyond.
448
00:53:40,961 --> 00:53:42,321
Kelly korreck: There was a moment,
449
00:53:42,401 --> 00:53:44,101
when we were putting
the spacecraft together,
450
00:53:44,121 --> 00:53:46,101
that I just took a moment
and looked at the spacecraft
451
00:53:46,121 --> 00:53:47,361
and realised,
452
00:53:47,441 --> 00:53:49,761
this is going into a star,
453
00:53:50,441 --> 00:53:53,961
and to realise how special it was
454
00:53:54,241 --> 00:53:56,641
to be able to have worked on this,
455
00:53:56,721 --> 00:54:00,681
and that humanity decided this was
something we wanted to do.
456
00:54:01,481 --> 00:54:03,601
- Male 1: Minus 30.
- Male 2: Status check.
457
00:54:03,921 --> 00:54:06,281
- Male 1: Pro delta.
- โmale 2:60 PSP.
458
00:54:06,841 --> 00:54:08,001
Male voice 1: Minus 75.
459
00:54:08,161 --> 00:54:10,761
Korreck: Launch night,
I was sick to my stomach.
460
00:54:11,201 --> 00:54:16,641
Male 3: Five, four, three, two,
one, zero.
461
00:54:17,521 --> 00:54:19,661
Lift-off of the mighty delta I I/...
462
00:54:19,681 --> 00:54:23,161
Hea vy rocket
with NASA's Parker solar probe.
463
00:54:23,241 --> 00:54:25,481
There we go...
464
00:54:25,561 --> 00:54:27,001
Dr chen: The spacecraft is the first
465
00:54:27,081 --> 00:54:29,081
that NASA has named
after a living person,
466
00:54:29,481 --> 00:54:31,281
because Eugene Parker is
467
00:54:31,361 --> 00:54:33,721
really such, you know,
an eminent physicist in our field.
468
00:54:36,081 --> 00:54:39,041
Korreck: The delta iv heavy
is a very slow rocket
469
00:54:39,121 --> 00:54:41,121
compared to the other launches
I've seen,
470
00:54:41,241 --> 00:54:43,121
so I just saw fireballs,
471
00:54:43,201 --> 00:54:46,161
and was very,
very frightened for a while.
472
00:54:46,241 --> 00:54:47,881
Male 1: T wenty-five seconds
into flight.
473
00:54:50,201 --> 00:54:52,761
Temp and pressures continue to look good
on all three boosters.
474
00:54:52,921 --> 00:54:56,721
Then realising that this was all okay
as it slowly made its way up
475
00:54:56,801 --> 00:54:58,081
into the sky.
476
00:54:59,161 --> 00:55:00,841
Male 1: Now 50 seconds into flight.
477
00:55:07,361 --> 00:55:10,281
Korreck: Parker solar probe is
so revolutionary
478
00:55:10,361 --> 00:55:13,921
because it's the first time that we're
actually going in to touch the sun.
479
00:55:15,521 --> 00:55:17,601
We 're going 94% of the way
480
00:55:17,681 --> 00:55:19,481
from the earth to the sun
481
00:55:19,561 --> 00:55:23,401
to actually experience the solar corona,
the sun's atmosphere.
482
00:55:24,641 --> 00:55:26,881
I think, at closest approach,
483
00:55:26,961 --> 00:55:30,001
it'll be about eight solar radii
from the sun
484
00:55:30,081 --> 00:55:32,921
which is just mind-blowingly close.
485
00:55:36,601 --> 00:55:39,721
Korreck: So, we were expecting
things to be very hot,
486
00:55:39,841 --> 00:55:42,801
over 2, 500 fahrenheit,
487
00:55:42,881 --> 00:55:46,081
but in a soup
of a million degree plasma.
488
00:55:50,561 --> 00:55:52,141
That's a real challenge
for the spacecraft
489
00:55:52,161 --> 00:55:53,641
to survive that environment.
490
00:55:53,881 --> 00:55:54,921
So, in order to do that,
491
00:55:55,001 --> 00:55:57,921
there's a very large heat shield
on the front of the spacecraft
492
00:55:58,001 --> 00:56:00,441
which protects
the majority of the instruments
493
00:56:00,521 --> 00:56:02,721
which are sat behind
on the spacecraft body.
494
00:56:05,041 --> 00:56:07,681
Korreck: What makes
Parker so great is the fact
495
00:56:07,761 --> 00:56:09,321
that it has a set of instruments
496
00:56:09,401 --> 00:56:12,481
that work together
in order to look in all directions
497
00:56:12,561 --> 00:56:16,001
in order to solve those big mysteries
about the solar wind.
498
00:56:23,321 --> 00:56:27,081
The solar corona has been mysterious
to us since we've known about it,
499
00:56:27,161 --> 00:56:28,641
so it's a very strange thing.
500
00:56:28,721 --> 00:56:32,521
The surface of the sun is
sort of 6,000 degrees
501
00:56:32,601 --> 00:56:35,161
and then, above that, you have
this very thin atmosphere
502
00:56:35,241 --> 00:56:36,641
that's a million degrees.
503
00:56:36,721 --> 00:56:37,841
Super-hot.
504
00:56:37,921 --> 00:56:39,841
And the way that's heated,
505
00:56:39,921 --> 00:56:42,361
we know it has something to do
with magnetic fields
506
00:56:42,441 --> 00:56:44,521
but we don't know exactly how it works.
507
00:56:44,641 --> 00:56:46,641
That's where
the solar wind is generated.
508
00:56:46,721 --> 00:56:48,681
We don't know quite exactly
how that works either.
509
00:56:51,081 --> 00:56:54,681
Korreck: Other things that have
come out of this are
510
00:56:54,761 --> 00:56:56,481
coronal mass ejections.
511
00:56:56,561 --> 00:56:59,081
When we originally did the proposal,
512
00:56:59,161 --> 00:57:02,521
we were thinking that we would see five
in the entire seven-year mission,
513
00:57:02,601 --> 00:57:04,161
if we were lucky.
514
00:57:06,041 --> 00:57:08,841
We ended up seeing around
four to five in the first year.
515
00:57:10,641 --> 00:57:13,881
So, there has been just a total switch
516
00:57:13,961 --> 00:57:17,361
in terms of how active the sun is
517
00:57:17,441 --> 00:57:19,481
or what we classify
as coronal mass ejections.
518
00:57:19,561 --> 00:57:20,881
Maybe a little bit of both.
519
00:57:27,161 --> 00:57:30,401
It is ajoy to see
all the data coming back.
520
00:57:30,481 --> 00:57:32,761
It's a joy to share it with others
521
00:57:32,841 --> 00:57:36,761
and to see them be as curious
as I have been for the last decade.
522
00:57:40,441 --> 00:57:42,321
50, Parker has just begun
its mission really,
523
00:57:42,401 --> 00:57:43,801
and it's already really started
524
00:57:43,881 --> 00:57:46,681
to truly transform our understanding
for how the sun works.
40812
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.