了解宇宙是如何运行的（2010）

How the Universe Works S08E01

Part 14 Jan. 30, 2022, 2:57 p.m.

我们该怎么办？
What do we do?
两个主要的可能性方案——
Two main possibilities --
we deflect it,
我们改变它的方向，轻推它一下，让它偏离目标
we nudge it a little bit
so it misses,
或者我们炸毁它，摧毁它
or we blow it up,
we destroy it.
你想做哪一个？
Which of those
do you want to do?
♪
这是一个艰难的选择
narrator: It's a tough choice.
如果弄错了，我们可能会被一群
Get it wrong, and we could
end up being hit by a swarm
放射性太空岩石攻击
of radioactive space rocks.
♪
♪
一颗小行星正朝我们飞来
narrator:
An asteroid is heading our way,
它可能会在2068年撞击我们
and it may hit us in 2068.
我们如何防止这样的灾难
How do we prevent
such a catastrophe
并阻止它接近？
and stop it
from ever getting close?
好吧，它一开始就不想
Well, you just don't want
to take get anywhere near us
靠近我们
in the first place.
那么你会怎么做呢？
So what do you do?
你可以毁掉他们
Well, you can destroy them,
或者也可以把他们推开
or you can push them
out of the way.
这是我们的科幻小说想法
This is something where our
science fiction ideas
几乎完全错误的地方
have got it almost
entirely wrong.
如果你在拍一部糟糕的电影，一部非常非常糟糕的电影
If you're in a bad movie,
a really, really bad movie,
你可以把宇航员送上一颗小行星
you can send astronauts
to an asteroid,
在里面放上一颗核弹
put a nuclear bomb in it,
把它炸成许多小碎片
and blow it up
into lots of little bits
然后在我们的大气层中无害地燃烧起来
<呵呵，这不就是电影《绝世天劫》吗？>
that then burn up harmlessly
in our atmosphere.
哎，不是这样的
Yeah, it doesn't work that way.
炸毁小行星
Narrator:
Blowing up an asteroid
会使问题变得更糟
would make the problem
much worse.
我们要处理的不再只是一块太空岩石
We are no longer dealing with
just one space rock.
我的质疑是，你可能把一个问题
My issue with this is that
you may have turned
变成了50个问题
one problem into 50.
不再是一个正常大小的小行星
Instead of one
regular sized asteroid,
现在是有一大堆小的小行星
now you have a whole bunch
of littler ones,
这些小行星仍然可能撞击地球并造成破坏
and these may still hit
the earth and cause damage.
你知道吗？这并没有比仅仅只有
And you know what?
That's not much less fun
一颗大的小行星少多少“乐趣”
than just having
a single big asteroid.
现在你已经承受了所有的破坏
Now you've just taken
all that devastation
并将其传播给所有人
and spread it out
for everybody to enjoy.
斯特里克:使用核装置的问题是
Stricker: The problem with using
a nuclear device is that
会像雨一样落到地球上的东西，并且还是有放射性的
the products that rain down
on earth are now radioactive.
♪
如果一颗危险的小行星要来了
narrator: If a dangerous
asteroid was on its way,
炸毁它将是最后的办法
blowing it up
would be a last resort.
一个风险较小的方法是使其偏离
A less risky method
is to deflect it off
碰撞路线
its collision course.
一个足够早的小推力
A small nudge early enough
可以改变小行星远离地球的轨道
can change in asteroid's
trajectory away from earth.
你不需要使劲推它就能打偏，对吧？
You don't have to nudge it
very much for it to miss, right?
所以如果正对着它
So if it's headed
straight at it,
我只是稍微碰它一下
I just touch it slightly,
当它到达地球的时候，它就偏离了轨道
by the time it gets to earth,
its way off course.
美国宇航局正在研究
Narrator: Nasa is investigating
ways to change
改变小行星轨道的方法，包括使用核爆♥炸♥
an asteroid's path,
including using a nuclear burst.
在核爆♥炸♥中，我们所做的就是不撞击它
In a nuclear burst, what we do
is we don't actually hit it.
我们把这个装置放在宇宙飞船上
We come up to it with the device
on a spacecraft,
然后这个装置会在离表面一定高度的地方
and then the device would be
detonated at a certain height
被引爆
above the surface.
普里特:这会使小行星表面升温
Plait: That heats up
the surface of the asteroid,
然后蒸发
which vaporizes.
气化的岩石或金属从表面爆♥炸♥
You get vaporized rock or metal
which blasts off the surface,
这就是火箭的工作原理
and that's how a rocket works.
所以你在这里引爆一枚炸♥弹♥
So you blow up a bomb here,
and it winds up
它最终会把小行星推向另一个方向
pushing the asteroid
in the other direction
为了防止任何潜在的核尘埃
narrator: To prevent
any potential nuclear fallout,
美国宇航局会在离地球很远的地方引爆♥炸♥弹
nasa would detonate the bomb
a long way from earth
普列斯科:任何偏离轨道的尝试都必须提前几年完成
plesko: Any deflection attempt
has to be done years in advance,
这意味着它将在
which means it would be done
on the other side
太阳系的另一边
of the solar system from us
在天体轨道的另一边进行
on the opposite side
of the object's orbit.
这意味着爆♥炸♥过程中
That means that all of
the vapor made during
产生的所有蒸汽都会被太阳风吹走
the explosion gets blown away
by the solar wind.
美国国家航♥空♥航♥天♥局正在研究其他使小行星偏转的
Narrator: Nasa is investigating
other less explosive methods
爆♥炸♥性较小的方法
of deflecting an asteroid.
De-star 方案会用激光摧毁小行星
De-star would blast the asteroid
with a laser.
奥卢西伊:我们用激光击中它，物质就会蒸发
Oluseyi: We hit it with
the laser, material vaporizes
然后飞离小行星
and flies off the asteroid,
根据牛顿第三定律，每一个作用力
and because
of newton's third law,
都会产生一个相反的等速反应
which is that for every action
there is an opposite
这意味着蒸发的物质
an equal reaction, this means
that vaporize material
朝一个方向移♥动♥，小行星
moving off in one direction
moves the asteroid
就会朝相反的方向移♥动♥
in the opposite direction.
激光和核爆
Narrator: Both the laser
and the nuclear burst
都还只是初步的设想
are still just ideas
on the drawing board.
但一项名为“双小行星重定向测试”(简称dart)的
<已经于2021年11月24日从加利福尼亚州发射升空>
<本记录片是在2020年1月2日在美国首播的>
But one asteroid
deflection mission called
小行星偏转任务
<已经于2021年11月24日从加利福尼亚州发射升空>
<本记录片是在2020年1月2日在美国首播的>
double asteroid redirection
test, or dart for short,
已经启动并开始运行，计划于2021年发射
<已经于2021年11月24日从加利福尼亚州发射升空>
<本记录片是在2020年1月2日在美国首播的>
is already up and running and
scheduled for launch in 2021.
Dart 是一种动能撞击器
Dart is a kinetic impactor
可以将小行星撞离轨道
and will try to knock
an asteroid off course.
塞勒:在美国宇航局，我们所能做的
Thaller: At nasa for the longest
time, all we've been able to do
就是从理论上解释我们如何改变他们的路径
is theorize about how
we change their path.
但现在，我们第一次
But now for the first time,
要进行实际练习了
we're actually gonna
practice in.
带领这项开创性的任务——