了解宇宙是如何运行的（2010）

How the Universe Works S08E01

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

这颗小行星正直直地向地球飞去
Narrator: The asteroid
is heading straight for earth
科罗拉多州的丹佛就在它的视野中
with denver, colorado,
in its sights.
行星防御系统的科学家们
The planetary defense
scientists
发射了一艘模拟宇宙飞船，将其撞向小行星
send up a simulated spacecraft
to smash into the asteroid
并将其推离轨道
and push it off its path.
但这是一场豪赌
But it's a big gamble.
你如果把它推错方向
You can push it
the wrong way.
你可能会产生意想不到的后果
You can potentially
have unintended consequences.
在模拟中
Narrator:
In the simulation,
宇宙飞船撞击了小行星……
the spacecraft
strikes the asteroid...
使它偏离地球
Deflecting it away from earth.
但撞击产生了一块200英尺长的碎片
But the impact dislodge
is a 200-foot chunk,
现在这个碎片正直直地向东海岸移♥动♥
which is now heading straight
towards the eastern seaboard.
这是最后一块碎片
So there's this one
last piece
它将在纽约引起轰动
that is now
going to hit new york.
我们知道这种规模的事件
We know that something that size
会对全市产生影响
is going to have
citywide consequences.
它很巨大这是一个可怕的影响
That is huge.
That's a horrible impact.
塞勒:当你坐在会议室里
Thaller: When you're actually
in the conference room
然后最终真正明白
and you understand eventually
纽约市将被摧毁……
that new york city
is going to be destroyed...
当你在做模拟的时候
And you're having strategies
about how to evacuate people,
你脑子里就有了疏散人群的策略
all the timing,
when you're doing the simulation
每时每刻都有
you're in your head.
你在思考这些事情
You're thinking
about these things.
你试图把它们推理出来
You're trying to
reason them out,
但你能想象你那时内心的感受吗
but can you imagine the feeling
in your gut, in your heart,
如果这是真的？
if this was real?
如果这是真的，那块小行星
Narrator: If this were real,
the chunk of asteroid
将以每小时43000英里（约69000公里）的速度
would strike earth's atmosphere
撞击地球大气层
at 43,000 miles an hour.
当太空岩石急速下落时
As the space rock hurtles
down, it collides
它与大气中的分子发生碰撞，使下落的岩石受到冲击
with molecules in the atmosphere
which buffet the falling rock.
这有点像在泳池里做腹部跳水，对吧?
It's kind of like doing
a belly flop into a pool, right?
在短短几秒钟内就从真空的太空
You're going from
the vacuum of space
进入稠密的低层大气
into the dense lower atmosphere
in mere seconds.
它会对物体施加
And that's an incredible
amount of pressure
难以置信的压力
to put on the object.
小行星撞向前方的空气
Narrator:
The asteroid slams into the air
猛烈地挤压着它
ahead of it,
compressing it violently.
小行星的表面变得越来越热，越来越亮
The surface of the asteroid
gets hotter and brighter.
杜尔达:实际上是空气本身
Durda:
It's actually the air itself
that's glowing luminously
由于冲击波的加热而发光
from the heating
of the shockwave,
这是世界上最强烈的音爆
the world's most
intense sonic boom if you will,
当物体经过时
that heats the air
to incandescence
空气被加热成白热化
as the object passes through.
这就是明亮的亮光的来源
So that's the source
of that brilliant illumination.
这颗明亮燃烧的小行星被称为火流星
Narrator: This bright, burning
asteroid is called a bolide.
2013年，我们目睹了俄♥罗♥斯♥车里雅宾斯克市
We witnessed one descending
over the russian city
上空的一次陨石降落
of chelyabinsk in 2013.
突然间，一个巨大的火球
All of a sudden, there was
a huge fireball
划过天空
streaking through the sky,
人们根本不知道他们看到了什么
and people had no idea
what they were witnessing
因为看起来天空着火了
because it looked like the sky
was on fire.
这简直是疯了
It was insanity.
随着小行星的下降
Narrator: As the asteroid
descends,
其下方密度较大的空气受到压缩
the compression
of the denser air beneath it
开始变平，甚至破坏了下落的岩石
starts to flatten and even
disrupt the falling rock.
奥卢西:前面有一个高压
Oluseyi: There's a high pressure
on the front,
但后面没有压力
there's no pressure on the back
而且温度加热非常高
and it's being super heated.
萨特:这种高温导致空气发光
Sutter:
And that intense temperature
causes the air to glow,
这就是我们看到的流星条纹
which is how we see
this streak of a meteor.
它也会分解小行星本体
And it also disintegrates
the asteroid itself.
这足以融化整个岩石
It's hard enough
to literally melt rock.
通常会导致它们爆♥炸♥
This can often
lead to them exploding.
热量和压力的结合
Narrator: The combination
of heat and pressure invade
侵入坠落的小行星，导致其爆♥炸♥
the falling asteroid,
causing it to blow up.
[爆♥炸♥]
[ explosion ]
大多数小行星在完全分解
most asteroids
don't reach the ground
并释放大量能量之前
before they
completely disintegrate
都没有到达地面
in a tremendous release
of energy.
普莱特:这就是我们所说的空中爆♥炸♥
Plait: This is what we call
an air burst,
我们在二战后
and we learned a lot about these
测试核武器时这方面了解了很多
while we were testing nuclear
weapons after world war ii.
有些炸♥弹♥是在地下
Some of these bombs
were blown up
和地面上引爆的
underground and on the ground,
但他们发现，当他们在地面上引爆♥炸♥弹时
but they found out when they
blew up bombs above the ground,
实际上会造成更大的破坏
it actually did more damage.
破坏范围更广
It was more widespread damage.
车里雅宾斯克小行星的爆♥炸♥
Narrator: The explosion of
the chelyabinsk asteroid
以每小时数千英里的速度发出了强大的冲击波
sent out a powerful shockwave
at thousands of miles an hour.
爆♥炸♥蔓延了100多英里（160多公里）
The blast traveled
over 100 miles.
它摧毁了7000栋建筑
It damaged 7,000 buildings
并使1500人住院
and put 1,500 people
in the hospital.
几乎所有的伤害都来自于那些
All of the injuries
pretty much came from people
看到并说：“哦，天空中那道闪光是什么？”
who saw, "oh, what's
that bright flash in the sky?"
然后他们走近一扇窗户想看看那是什么
and they came close to a window
to look and see what it was,
于是压力波击中了他们，把玻璃吹到他们脸上
and then the pressure wave hit
and blew glass in their face.
车里雅宾斯克小行星直径只有65英尺（约20米）
Narrator:
The chelyabinsk asteroid
was only 65 feet across.
防御模拟中的那块石头
The rock in the
defense simulation
要大三倍
is three times more massive,
而且正直直地向纽约市飞去
and it's heading straight
for new york city.
想象一下，如果一个比广岛原♥子♥弹♥