了解宇宙是如何运行的（2010）

How the Universe Works S06E08

Part 8 Dec. 22, 2021, 7:23 p.m.

太阳的演化
that we have to take
into account.
行星本身和它们的轨道都在进化
The planets themselves
and their orbits are evolving.
它们看起来很稳定，但经过很长一段时间
They look stable,
but over long time periods,
它们可能会发生巨大的变化
they can change drastically.
太阳产生的引力
The Sun exerts the
strongest gravitational pull
是太阳系中最强的
of any object
in the solar system.
这就是为什么行星绕着它旋转
It's why the planets orbit it,
但行星也会相互拉扯
but planets can also
pull on each other.
水星很小，这使得它最容易受到
Mercury is tiny,
making it most vulnerable
引力拖曳的影响
to these gravitational tugs.
仅次于太阳的是木星
After the Sun, the next
biggest object is Jupiter.
我们可以用计算机模型
We can take computer
models and simulate
模拟水星受木星影响时的轨道
Mercury's orbit
as it's affected by Jupiter
看看水星会发生什么
to see what happens to Mercury,
根据初始条件
and depending
on initial conditions,
会发生很多不同的事情
a lot of different
things can happen.
但在某些模型中，可能会发生的情况是
But in some percentage
of the models, what can happen
水星的轨道会发生大变化
is Mercury's orbit
changes so much
以至于它实际上会向外摆动
that it actually swings out
并能到达地球的轨道
and can reach the orbit
of the Earth.
木星经常被视为太阳系的恶霸
Jupiter is often seen as the
bully of the solar system.
这里，它成了水星的保镖
Here, it's Mercury's bodyguard.
随着时间的推移，它的引力作用
Over time, its
gravitational influence
将水星的轨道延伸得越来越远
stretches Mercury's orbit
out farther and farther,
这个小世界在太阳膨胀成红巨星之前
and the little world escapes
the Sun's clutches
早就脱离了太阳的控制
long before it expands
to a red giant.
但这个故事还有一个转折
But this tale
has one final twist.
把水星排除在行星的万神殿中是很容易的
It's easy to dismiss Mercury
in the pantheon of planets,
但是忽视它会让你很危险，因为有一天
but ignore it at your peril
because there may come a day
水星会让它的存在非常出名
when Mercury makes its presence
very well known indeed.
我想水星在过去的45亿年里
I'd like to think that Mercury
does not bear the solar system
对太阳系没有任何恶意
any ill will for
all the hard time
但是，你知道
it's been given over
the last 4.5 billion years,
这么长时间就会产生怨恨
but, you know, that's a long
time to build up a grudge.
水星的过去很艰难
Mercury has had
such a difficult past.
它被太阳摧残，与其他行星♥相♥撞
It's been beat on by the Sun,
collided with other planets.
现在水星可能会过来，开始对我们造成严重破坏
Now Mercury could come in and
start wreaking havoc with us,
所以也许我们可以把这看作是水星的复仇
so maybe we can think of this
as sort of Mercury's revenge.
数十亿年前
Billions of years ago,
地球很可能与年轻的水星♥相♥撞
Earth could well have collided
永远地改变了水星
with the young Mercury,
changing Mercury forever.
现在，它再次与地球面对面……
And now, it comes face-to-face
with Earth once again...
最后一次撞击地球
Smashing into our planet
in one, final impact,
并抹去我们所熟知和喜爱的世界的一切痕迹
wiping out any trace
of the world we know and love.
它会融化我们整个地壳
It would melt our entire crust.
它会毁灭地球上所有的生命
It would wipe out all life
on our planet.
那么，我们应该对这种威胁有多担心呢？
So how worried should
we be about this threat?
这种情况发生的几率并没有那么高
The odds of this happening
aren't that high,
如果它发生了
and if it happens,
it's going to happen
那也是在数十亿年后发生
billions of years in the future.
所以从个人角度来说，我不是很担心
So I'm not terribly worried
about it on a personal scale,
但作为一个天文学家和科学家，这很吸引人
but as an astronomer and as
a scientist, that's fascinating.
水星可能会继续让我们惊讶
Mercury may continue
to surprise us,
甚至到它死亡的那一天
even to its dying day,
一个诞生于火焰中的世界也可能在火焰中毁灭
a world born in fire that
might also go down in flames.
但它能走到这一步
But the fact that
it made it this far
实在是太了不起了
is nothing short of remarkable.
水星生活在你能想象到的最艰苦的地方
Living in the toughest
neighborhood imaginable,
它在太阳系的历史中被摧残
Mercury has made it through
the history of the solar system,
但并没有被摧毁
beaten, but not broken.
水星是太阳系中最伟大的幸存者之一
Mercury is one of the solar
system's great survivors.
尽管发生了那么多事情
Despite all of the things
that happened to it,
它仍然坚持在那里
it's still hanging in there.
它经历了太阳系中最严酷的环境
It's been subject to
the harshest environment
但它仍然存在
in the solar system,
and it's still around.
水星，你知道，它受到了来自四面八方的攻击，对吧?
Mercury, you know, has been
attacked from all sides, right?
它被太阳烤焦了
It's been roasted by the Sun.
它遭受了撞击，但它仍然在那里
It's been pummeled by impactors,
and yet it's still there,
仍然是一个伟大的行星
still being a great planet,
这个勇敢的小幸存者，尽管经历了一切
this plucky, little survivor
who's still orbiting
仍然在轨道上运行
despite everything
it's gone through.