WEBVTT

1
00:00:03.439 --> 00:00:08.880
Welcome to Bedtime Astronomy. Explore the
wonders of the cosmos with our soothing Bedtime

2
00:00:08.880 --> 00:00:14.560
Astronomi podcast. Each episode offers a
gentle journey through the stars, planets,

3
00:00:14.800 --> 00:00:19.800
and beyond, perfect for unwinding after
a long day. Let's travel through the

4
00:00:19.800 --> 00:00:23.480
mysteries of the universe as you drift
off into a peaceful slumber under the night

5
00:00:23.559 --> 00:00:33.920
sky. A journey to the Earth's
core. Have you ever wondered what lies

6
00:00:33.960 --> 00:00:40.159
beneath our feet? Our planet Earth
is not just a solid ball of rock.

7
00:00:42.280 --> 00:00:48.640
It has distinct layers, each with
its unique composition and properties, much

8
00:00:48.840 --> 00:00:56.439
like a giant onion. Unlike an
onion, however, we can't simply peel

9
00:00:56.520 --> 00:01:03.200
back these layers to see what's inside. The immense pressure and scorching temperatures deep

10
00:01:03.280 --> 00:01:12.719
within the Earth make direct exploration impossible. But thanks to scientific advancements like seismology,

11
00:01:14.359 --> 00:01:19.599
which studies the vibrations of earthquakes,
we can virtually dissect our planet and

12
00:01:19.719 --> 00:01:32.200
peer into its hidden depths, unveiling
the first layer, the crust. The

13
00:01:32.319 --> 00:01:38.280
outermost layer, the familiar ground we
walk and build on, is called the

14
00:01:38.359 --> 00:01:45.359
crust. It's the thinnest layer,
a mere eggshell Compared to the rest of

15
00:01:45.400 --> 00:01:55.599
the Earth, continental crust or mountains
rise and continent sprawl averages around thirty kilometers

16
00:01:55.959 --> 00:02:04.480
eighteen miles thick. Even thinner is
the oceanic crust, which floors our oceans

17
00:02:04.480 --> 00:02:12.360
at a depth of around five to
ten kilometers three to six miles. Despite

18
00:02:12.400 --> 00:02:20.039
its thinness, the crust punches above
its weight in importance. It's the foundation

19
00:02:20.280 --> 00:02:24.919
for our continents and ocean basins,
holding the rich tapestry of life on its

20
00:02:24.919 --> 00:02:34.039
surface. The crust also harbors the
mineral deposits and fossil fuels that fuel our

21
00:02:34.120 --> 00:02:43.319
civilization. Most importantly, it acts
as a giant insulating shield, protecting us

22
00:02:43.319 --> 00:02:53.280
from the scorching heat emanating from the
Earth's interior. Diving deeper the fiery mantle,

23
00:02:57.039 --> 00:03:02.080
delving beneath the crust, we encounter
the mantle, the Earth's most voluminous

24
00:03:02.159 --> 00:03:09.960
layer, accounting for roughly eighty four
percent of our planet's volume. Imagine a

25
00:03:10.039 --> 00:03:19.479
gigantic, solid, yet squishy sphere
roughly two thousand, nine hundred kilometers one

26
00:03:19.560 --> 00:03:27.400
thousand, eight hundred miles thick.
Unlike the brittle crust, the mantle is

27
00:03:27.479 --> 00:03:34.120
composed of hot, dense rock,
primarily a mix of silicon and magnesium rich

28
00:03:34.240 --> 00:03:42.080
minerals we wouldn't recognize on the surface. The intense heat, ranging from five

29
00:03:42.199 --> 00:03:49.360
hundred degrees celsius to a scorching two
thousand degrees celsius nine hundred and thirty two

30
00:03:49.439 --> 00:03:55.000
degrees fahrenheit to three thousand, six
hundred and thirty two degrees fahrenheit, keeps

31
00:03:55.039 --> 00:04:02.919
the lower mantle in a solid state. However, the upper mantle experiences a

32
00:04:02.960 --> 00:04:12.080
different story. Ere The combined effects
of heat and pressure create a plastic like

33
00:04:12.199 --> 00:04:19.319
zone called the asthenosphere. This layer
behaves somewhat like hot asphalt, allowing the

34
00:04:19.439 --> 00:04:26.639
rigid rock above called the lithosphere,
which includes the crust and the upper mantle,

35
00:04:27.360 --> 00:04:33.879
to move and slow churning motions.
The movement of the asthenosphere is akin

36
00:04:34.000 --> 00:04:41.600
to a giant conveyor belt, driving
the motion of tectonic plates, the enormous

37
00:04:41.639 --> 00:04:48.879
slaps that form Earth's surface. These
plates, like pieces of a colossal jigsaw

38
00:04:48.959 --> 00:04:56.720
puzzle, float on the asthenosphere,
grinding past each other, pushing together,

39
00:04:57.480 --> 00:05:03.160
and even pulling apart. It's the
movement of these plates that is responsible for

40
00:05:03.319 --> 00:05:11.439
phenomena that shape our planet's surface,
like continental drift. The majestic rise of

41
00:05:11.560 --> 00:05:23.759
mountain ranges and the destructive power of
earthquakes. A molten heart the outer core,

42
00:05:25.279 --> 00:05:31.800
Our descent continues towards the Earth's fiery
heart. The core, unlike the

43
00:05:31.920 --> 00:05:36.600
solid mantle above, the core,
is believed to be a churning sea of

44
00:05:36.720 --> 00:05:46.279
molten metal, primarily iron and nickel. Here, the temperature reaches a staggering

45
00:05:46.399 --> 00:05:53.199
two thousand, four hundred degrees celsius
to a mind boggling six thousand degrees celsius

46
00:05:53.600 --> 00:05:58.920
for one thousand, three hundred and
fifty two degrees fahrenheit to ten thousand,

47
00:05:59.000 --> 00:06:03.120
eight hundred and five thirty two degrees
fahrenheit, odd enough to melt any rock

48
00:06:03.240 --> 00:06:11.439
we know, but the immense pressure
millions of times greater than at the surface

49
00:06:12.240 --> 00:06:18.199
keeps this molten metal from vaporizing.
Imagine the pressure at the bottom of the

50
00:06:18.319 --> 00:06:26.519
deepest ocean trench multiplied by millions.
That's the kind of crushing force keeping the

51
00:06:26.560 --> 00:06:31.839
outer core in a liquid state.
The swirling motion of this outer core,

52
00:06:32.560 --> 00:06:39.399
combined with Earth's rotation, is thought
to be the engine that generates our planet's

53
00:06:39.480 --> 00:06:48.000
magnetic field. This invisible shield protects
us from harmful solar radiation and energetic particles

54
00:06:48.120 --> 00:06:56.000
that would otherwise bombard the surface,
potentially stripping away our atmosphere and hindering the

55
00:06:56.079 --> 00:07:03.319
development of life as we know it. The enigma within the inner core.

56
00:07:06.639 --> 00:07:13.800
As we venture deeper towards the Earth's
center, the temperature and pressure continue to

57
00:07:13.920 --> 00:07:20.519
rise to unimaginable extremes, exceeding the
harshest conditions ever created here on the surface.

58
00:07:23.680 --> 00:07:29.920
Here we encounter the enigmatic inner core, a solid ball roughly the size

59
00:07:29.959 --> 00:07:36.240
of Mars, nestled within the molten
outer core. Unlike the outer core,

60
00:07:36.759 --> 00:07:43.480
the inner core is believed to be
primarily composed of iron, with a smaller

61
00:07:43.519 --> 00:07:49.879
percentage of nickel. Despite the scorching
temperatures that would melt any rock we know,

62
00:07:50.879 --> 00:07:57.920
scientists theorize the immense pressure exceeding anything
found at the surface is enough to

63
00:07:58.040 --> 00:08:03.360
force the iron atoms into a tightly
packed crystal structure, baking the inner core

64
00:08:03.439 --> 00:08:13.639
a giant ball of super solid metal, A crucible of change. The Core's

65
00:08:13.720 --> 00:08:22.000
influence on Earth. Though hidden from
sight, the Earth's core plays a vital

66
00:08:22.120 --> 00:08:30.040
role in shaping our planets past,
present, and future. The churning out

67
00:08:30.279 --> 00:08:35.600
core's movement, as mentioned earlier,
is believed to be the engine that generates

68
00:08:35.679 --> 00:08:46.360
Earth's magnetic field. This invisible shield
deflects harmful solar radiation and charged particles from

69
00:08:46.360 --> 00:08:52.159
the Sun, preventing them from stripping
away our atmosphere and bombarding living organisms with

70
00:08:52.320 --> 00:09:01.000
harmful radiation. Without this crucial protection, life is we know, it wouldn't

71
00:09:01.039 --> 00:09:09.360
be possible. Additionally, the heat
emanating from the core is thought to be

72
00:09:09.440 --> 00:09:16.480
the driving force behind the movement of
the tectonic plates and the mantle. As

73
00:09:16.519 --> 00:09:22.320
the core loses heat, it creates
convection currents that rise and pull the mantle

74
00:09:22.360 --> 00:09:31.159
in a slow churning motion. This
movement of tectonic plates is responsible for continental

75
00:09:31.240 --> 00:09:37.679
drift, the majestic rise of mountain
ranges, the formation of ocean trenches,

76
00:09:37.399 --> 00:09:46.679
and even the destructive power of earthquakes
and volcanic eruptions. In essence, the

77
00:09:46.799 --> 00:09:52.759
core acts like a giant internal furnace, constantly shaping and reshaping the Earth's surface

78
00:09:52.960 --> 00:10:01.159
through its influence on the mantle,
unveiling the ma histories. The challenge is

79
00:10:01.200 --> 00:10:11.320
an intrigue of studying the core.
Studying the Earth's core presents a unique challenge

80
00:10:11.399 --> 00:10:18.480
for scientists, unlike anything encountered in
examining the crust or mantle. We can

81
00:10:18.559 --> 00:10:26.320
analyze rock samples brought to the surface
by volcanoes or drilling to understand the composition

82
00:10:26.480 --> 00:10:33.919
of the outer layers. However,
the core remains stubbornly out of direct reach.

83
00:10:35.080 --> 00:10:41.840
Our knowledge about the core's composition in
properties comes primarily from studying seismic waves

84
00:10:43.679 --> 00:10:50.799
vibrations that travel through the Earth during
earthquakes. By analyzing how these waves travel

85
00:10:50.960 --> 00:10:56.799
and bend as they pass through the
different layers, scientists can piece together a

86
00:10:56.799 --> 00:11:05.320
picture of the core's density and ste
solid of a liquid. However, the

87
00:11:05.360 --> 00:11:11.360
intense heat and pressure at the core's
depth make it a constantly evolving and dynamic

88
00:11:11.519 --> 00:11:18.519
environment. The sheer scale of the
core, coupled with the limitations of our

89
00:11:18.559 --> 00:11:26.080
current technology, leaves many aspects still
shrouded in mystery. It's a testament to

90
00:11:26.200 --> 00:11:33.759
human ingenuity that scientists can glean so
much about this hidden realm using indirect methods,

91
00:11:33.360 --> 00:11:39.279
but the unanswered questions continue to fuel
our fascination with the Earth's fiery heart,

92
00:11:43.519 --> 00:11:52.120
a glimpse into the future. Exploring
the core secrets while directly reaching the

93
00:11:52.120 --> 00:11:58.879
Earth's core remains a technological hurdle.
Scientists are constantly chipping away at the end.

94
00:12:00.120 --> 00:12:09.200
Known advancements in seismology are providing evermore
detailed pictures of the core structure and

95
00:12:09.320 --> 00:12:16.960
dynamics. Imagine a future where incredibly
powerful seismic networks can map the core with

96
00:12:18.159 --> 00:12:26.039
unprecedented resolution, revealing cell variations in
density and composition that might hint at hidden

97
00:12:26.120 --> 00:12:35.559
processes or structures. Additionally, research
into high pressure and high temperature materials might

98
00:12:35.679 --> 00:12:41.679
one day allow us to create probes
capable of withstanding the cores crushing conditions.

99
00:12:43.720 --> 00:12:50.639
These robotic explorers could descend into the
Earth's depths, sending back in valuable data

100
00:12:50.720 --> 00:12:56.799
about the course, composition, temperature
variations, and even the potential existence of

101
00:12:56.840 --> 00:13:05.600
a solid liquid boundary within in the
outer core. Such missions could revolutionize our

102
00:13:05.679 --> 00:13:13.320
understanding of Earth's formation and evolution.
They might even pave the way for similar

103
00:13:13.399 --> 00:13:22.679
explorations of other planets, ushering in
a new era of planetary science. The

104
00:13:22.799 --> 00:13:31.440
corese connection to the cosmos a universal
story. The Earth's core is not just

105
00:13:31.519 --> 00:13:39.360
a unique feature of our home planet. It's believed that most rocky planets in

106
00:13:39.440 --> 00:13:46.200
our Solar System and perhaps even beyond, have cores made primarily of iron.

107
00:13:48.279 --> 00:13:52.799
These cores are thought to have formed
during the violent birth of these celestial bodies,

108
00:13:54.480 --> 00:14:01.840
as gravity pulled in denser elements like
iron towards the center. Studying the

109
00:14:01.879 --> 00:14:09.200
Earth's core therefore becomes a window into
understanding the formation and evolution of planets throughout

110
00:14:09.240 --> 00:14:16.080
the cosmos. By comparing the properties
of Earth's core with what we can infer

111
00:14:16.159 --> 00:14:24.639
about the cores of other planets through
gravitational measurements and astronomical observations, we can

112
00:14:24.720 --> 00:14:31.440
gain insights into the building blocks and
processes that shaped our Solar System and potentially

113
00:14:31.559 --> 00:14:39.279
countless others. For example, a
strong magnetic field on another planet might suggest

114
00:14:39.360 --> 00:14:45.720
a core similar to Earth's, with
a churning outer core generating the field.

115
00:14:46.840 --> 00:14:54.799
Conversely, a weak or absent magnetic
field could indicate a different core composition or

116
00:14:54.840 --> 00:15:07.440
structure. Conclusion, our exploration of
the Earth's interior has revealed a hidden world

117
00:15:07.679 --> 00:15:15.720
unlike anything on the surface. The
layers from the thin, rocky crust to

118
00:15:15.759 --> 00:15:22.720
the fiery, churning core work in
a complex interplay, a symphony of geology.

119
00:15:22.000 --> 00:15:30.399
Unlike any human made machine. This
intricate dance shapes our planet's geology,

120
00:15:31.120 --> 00:15:37.399
climate, and even the possibility of
life. The Earth is not a static

121
00:15:37.480 --> 00:15:46.759
ball of rock. It's a dynamic
system, constantly changing and evolving. The

122
00:15:46.879 --> 00:15:52.799
core acts as a powerful engine,
driving change from the inside out, influencing

123
00:15:52.840 --> 00:16:00.919
the movement of tectonic plates that sculpt
mountains and continents. It also generates the

124
00:16:00.960 --> 00:16:07.480
magnetic field that protects us from harmful
solar radiation, a crucial factor for the

125
00:16:07.559 --> 00:16:15.240
development and continuation of life. As
we continue to unravel the mysteries of the

126
00:16:15.279 --> 00:16:21.600
Earth's interior, we gain a deeper
appreciation for the delicate balance that makes our

127
00:16:21.720 --> 00:16:29.639
planet a habitable oasis in the vast
expanse of space. This newfound knowledge not

128
00:16:29.759 --> 00:16:36.039
only helps us predict and prepare for
geological events, but also fuels our curiosity

129
00:16:36.080 --> 00:16:41.159
about the formation and potential for life
on other planets within our Solar system and

130
00:16:41.240 --> 00:17:57.079
beyond. The un en