了解宇宙是如何运行的（2010）

How the Universe Works S08E09

Part 2 Jan. 30, 2022, 2:59 p.m.

轨道上运行
through the early solar system,
我们的星球冷却下来，表面变成固体
our planet cooled,
and the surface became solid.
♪
但暴♥力♥并未结束
but the violence wasn't over.
年轻的地球
The young earth was bombarded
在太阳系形成之初遭受过撞击
in the early days
of the solar system,
当这些岩石撞击地球时
and when these rocks
hit the earth,
它们几乎从未下面撞击地球
they almost never hit
directly on.
他们会以一定角度撞击
They'd hit at an angle.
♪
每一次碰撞，都会给地球
with each collision, it adds
a little bit more momentum
增加一点动量和自转
and a little bit more spin
to the earth.
你得到的附加旋转有点像旋转木马
The added spin that you get is
a kind of like a merry-go-round.
你可以想象，每个孩子都在蹦跳着
You can imagine with each kid
that pushes and jumps
推着旋转木马，于是就有了更快的旋转
on the merry-go-round,
you have greater spin.
当我们的星球运行时，小行星的撞击
Narrator: As our planet
journeyed on, asteroid impacts
使年轻的地球
set the young earth
以比现在快12倍的速度旋转
spinning 12 times faster
than it does today.
地球的转速对生命有着巨大的影响
Our planet's rotational speed
has huge consequences for life.
在地球上，地球的自转
On earth, the spin of our planet
实际上会影响我们的天气
actually has an effect
on our weather.
随着白昼变短
With a shorter day,
在当时可能在地球上很明显的影响之一
one of the effects that might
have been apparent on earth
就是产生了更多的风暴
at that time
was more storms developing.
[电闪雷鸣]
[ thunder crashes ]
一种至今仍在发生的现象
narrator: A phenomenon
still in action today
导致了这些强大的古代风暴
drove these powerful
ancient storms.
我们称之为科里奥利效应
We call it the coriolis effect.
地球自转使得地球的大气层
The earth's spin
creates phenomena
和海洋中产生了各种现象
in earth's atmosphere
and oceans.
这决定了与太阳热能
This determines patterns
of circulation
结合的循环模式
in combination with
the heat energy from the sun.
[电闪雷鸣]
[ thunder crashes ]
地球的自转与太阳的加热相匹配
the rotation of the earth
matched with solar heating,
特别是在赤道，导致空气上升
especially at the equator,
causes air to rise up
然后也会向侧面移♥动♥，并形成自旋
and then also sort of to move
sideways and sets up spin.
当年轻的地球继续它的旅程
Narrator: As the young earth
continued its journey,
行星的旋转激起了猛烈的，整个行星范围的风暴
the planet's rotation whipped up
ferocious, planet-wide storms.
快速旋转对任何生命都是灾难性的
The fast spin would have been
disastrous for any life.
风暴如此强大
The storms would have
been so big,
很难说生命是否会进化
it's hard to say if life
would have evolved at all.
幸运的是
Narrator: Fortunately
for humankind,
地球有一个旅伴——
earth has a
traveling companion --
月球，是它减缓了地球的自转速度
the moon, and it helped
slow our planet's spin.
接下来发生的是这两个物体之间
What happened next was kind of
a wonderful gravitational dance
奇妙的引力舞蹈
between these two bodies.
当它们旋转的时候，它们也会
As they were spinning,
they were also interacting
相互作用
with each other.
月球的引力吸引着地球上的海洋
Narrator: The moon's gravity
pulled on earth's oceans,
导致潮汐隆起
generating tidal bulges.
在潮汐中进进出出的物质在旋转时会膨胀
Materials moving in and out of
the tidal bulges as they spun,
这就产生了摩擦力和一种阻力
and this creates friction
and a kind of drag
实际上减缓了旋转
that actually slowed down
the rotation.
♪
潮汐也帮助创造了生命
narrator: The tides also
helped create life.
巨大的潮汐第一次把营养物质
Giant tides swept nutrients
from the land
从陆地带到海洋
into the oceans
for the first time.
一种原始的汤开始酝酿
A primordial soup began brewing.
♪
于是生命崛起
and life arose.
♪
随着地球自转的继续减慢
as earth's spin continued
to slow down,
♪
生命在这个星球上蔓延开来
life spread across the planet.
♪
但地球的自转只是我们宇宙旅程的一部分
but our planet's spin is just
one part of our cosmic ride.
意识到宇宙中更大的环境是多么复杂
Realizing how complicated
our larger environment
是一件美妙的事情
in the universe is
is a wonderful thing.
有很多东西会影响地球的轨道
There's so many things that
affect the orbit of the earth,
地球的倾斜，并影响我们的气候
the tilt of the earth,
things that affect our climate.
♪
地球在太空中航行的线索
narrator: Clues to earth's
space voyage are hidden
隐藏在世界各地
all across the world.
我们这个星球上最干燥的地方曾经是潮湿的
Could our planet's
wild ride explain
我们星球的狂野之旅能解释这一点吗？
how one of the driest places
on the planet was once wet?
♪
♪
♪
撒哈拉沙漠——这里干燥，尘土飞扬，还很荒凉
narrator: The sahara desert --
dry, dusty, desolate.
♪
但隐藏在沙漠洞穴深处的线索表明
but hidden deep in a desert cave
几千年前，撒哈拉沙漠
is a clue that
thousands of years ago,
曾是一个郁郁葱葱的绿色天堂
the sahara was a lush,
green paradise.
考古学家已经挖掘出了岩画
Archaeologists have
unearthed rock art
这些岩画清楚地描绘了人类和动物在湖泊中游泳
which clearly depicts humans
and animals swimming in lakes,
通过观察卫星图像
and by looking
at satellite images,
我们可以勾画出古代河谷的轮廓
we can trace out the outlines
of ancient river valleys.
♪
地球的快速自转影响了
narrator: The earth's fast
rotation influenced
地球古老的气候模式
our planet's ancient
weather patterns.
会不会是另一种运动改变了沙漠气候？
Could another motion
have changed the desert climate?
要解开这个谜题，我们需要将时钟
To unravel the mystery,
we need to rewind the clock
倒回46亿年前
4.6 billion years
♪
那时婴儿时期的太阳系
to when the infant solar system
是一个行星射击场
was a planetary
shooting gallery
♪
地球以轻微的倾斜旋转在太阳系中穿行
and the earth spun through the
solar system with a slight tilt.
早些时候，在月球形成之前
Earlier on, before
the formation of the moon,
地球并没有太大的倾斜度
the earth didn't have
much of a tilt,
撞击使我们完全失去了平衡
and the impact knocked us
completely out of whack
达到了大约80度
to about 80 degrees.
[爆♥炸♥]
[ explosion ]
我们的星球可能会
narrator: Our planet might have
continued its journey