了解宇宙是如何运行的（2010）

How the Universe Works S01E02

Part 2 April 18, 2021, 7:55 p.m.

首先黑洞吞噬大气, 接着吞噬地球
First, it would swallow up the
atmosphere, then the planet itself.
摧毁整个太阳系对黑洞来说是小事
Destroying an entire solar
system is nothing to a black hole,
它不仅是个拼命吞噬的空间
but it's more than just a big
empty sucking piece of space.
它的重量亦大得惊人
It's incredibly heavy.
要想知道黑洞有多重和密度多大
To get an idea just how heavy
and dense a black hole is,
以地球为例
imagine the Earth.
现在开始把它压缩
Now, start to crush it.
不断压缩, 以至越来越紧
And keep crushing until
it's packed so tight,
直至原子也被压碎
even the atoms themselves collapse.
当地球被挤压成为直径两吋的球体
When the Earth crushes down
to just two inches across,
它的密度就与黑洞相同
that's the density of a black hole.
虽然变成了高尔夫球那么小
It would be the size of a golf ball,
但地球的重量和引力都不变
yet weigh the same as the Earth
with the same amount of gravity.
物质是怎样能够变得这么小…
What can make something that small
密度这样大和这么强大呢?
that dense and that powerful?
我们没有外力
We don't have external forces,
large pistons in the universe,
没有制♥造♥黑洞的巨型活塞
to create black holes.
因此黑洞在宇宙中形成的唯一方式
So the only way the real black
holes in the universe form
就是引力自身的力量
is if gravity could do the job itself.
宇宙中只有一个地方
There is only one place in the universe
能够产生如此强大的引力
that generates that much gravity
就是巨型恒星内部
and it's inside the largest stars.
当10倍于太阳重量的庞大恒星死亡
When massive stars, 10 times
heavier than our sun die,
会在引力的挤压下发生剧烈爆♥炸♥
gravity crushes them
creating a huge explosion:
形成超新星
a supernova.
但有些恒星甚至更大
But some stars are
even bigger than that.
这些超巨星比太阳重100倍
These supermassive stars weigh
100 times more than our sun
引力亦大100倍
and have 100 times more gravity.
当超巨星死亡时
When one of these stars dies,
会引发宇宙中最剧烈爆♥炸♥
it sets off the biggest
explosion in the universe:
形成了特超新星
a hypernova.
黑洞就是这样诞生的
This is the birth of a black hole.
我们的宇宙恒星密布
Our universe is full of stars.
当恒星死亡时, 有些静悄悄
At the end of their
lives, some die quietly.
有些则会引发剧烈爆♥炸♥
Others go out in spectacular explosions,
有些甚至形成黑洞
and some give birth to black holes.
当一颗质量是太阳100倍的超巨星
If you have a star, a supermassive star
that's a hundred times the mass of the sun
死亡时
at the end of its life,
内核的燃料已经枯竭
the core runs out of fuel,
无法维持燃烧
there's nothing left to hold it up,
内核就会塌陷形成一个黑洞
and the core collapses
down into a black hole.
超巨星核心产生的巨大引力
When that happens,
将会肆无忌惮
the enormous gravity generated at the
heart of supermassive stars runs wild.
这是即将消亡的大犬座VY超巨星
This is the dying star VY Canis Majoris.
直径超过10亿哩
It's more than a billion miles across.
像个向外喷发能量的核聚变反应堆
Like all stars, it's a giant nuclear
fusion reactor pumping energy outward.
同时它的强大引力向内挤压
At the same time, the star's
extreme gravity crushes inward.
核聚变和引力互相制衡达几百万年
For a few million years, fusion
and gravity are locked in stand-off.
当恒星的燃料耗尽时
But when the star runs out of fuel,
核聚变停止, 僵局结束
fusion stops and the stalemate ends.
引力取得胜利
Gravity wins.
一毫秒后恒星的内核
In a millisecond, the core shrinks
压缩至原体积的一小部分
to a fraction of its original size
一个婴儿黑洞诞生了
and a baby black hole is born.
它立刻开始吞噬恒星剩余部分
Immediately, it starts to
cannibalise what's left of the star.
随着物质不断卷入黑洞
As matter swirls into the black hole,
这里变得异常炙热
it gets incredibly hot
于是产生了磁力和摩擦力
and there are magnetic
forces and frictional forces
黑洞表面发生的一切
and it's just a witch's
brew, a nightmare,
就像噩梦一样
what's going on right above
the surface of the black hole.
中间的新生黑洞不断吞噬恒星
The new black hole in the middle keeps
feeding on the body of the star around it.
它的吞食速度太快
It eats the gas so fast
会噎住和咳, 喷出巨大能量
it chokes and coughs blasting
out huge beams of energy.
黑洞实际上是由内而外地吞噬恒星
They basically eat their
way out from the star.
这一切的发生只用了几毫秒
This happens in milliseconds.
其余部分还未知道内核已被吞噬
It happens before the rest of the
star even knows the core is gone,
所以恒星的死是从内而外的
and so basically, the star is
dead before it hits the ground.
最后, 恒星爆♥炸♥
Finally, the star explodes.
一秒钟之内恒星爆♥炸♥产生的能量
In one second, it blasts out
a hundred times more energy
比太阳产生的所有能量还多100倍
than our sun will produce
over its entire life.
爆♥炸♥后只剩下一个新生黑洞
What's left is a new black
hole and two jets of energy
和两道以光速穿过宇宙的能量束
hurtling through the universe
at the speed of light.
这就是伽马射线暴
These jets are called gamma ray bursts.
它们的能量高得惊人
They're incredibly energetic events.
在原能量和力量方面
In terms of raw energy and power,
伽马射线暴仅次于宇宙大爆♥炸♥
gamma ray bursts are second
only to the big bang itself.
大多数只持续几秒钟
Most of them last only a few seconds,
但它会摧毁途经的一切
and they fry anything in their way.
它们非常强烈
They're so intense
若伽马射线暴存在于…
that if there was a gamma ray burster
银河系的太阳系附近
in the region of our galaxy
near our solar system,
它会使整个地球蒸发
it could literally
vaporise the entire planet.
幸运的是大多数伽马射线暴
Fortunately, most gamma ray bursts
都发生在银河系以外
occur outside our galaxy.
但它们亦为我们揭示出
But they tell us something
important about black holes
有关黑洞和宇宙的奥秘
and how our universe works.
我们每次看到的伽马射线暴
What we were seeing, every
time a gamma ray burst went off,
都是黑洞诞生的第一声啼哭
was basically the
birth-cry of a black hole.
天文学家通过计算伽马射线暴次数
By counting gamma ray bursts,
推算出黑洞的数量
astronomers can figure out how
many black holes are being created.
2004年太空总署发射了雨燕探测器
In 2004, NASA launched the Swift Probe
用于寻找宇宙中的伽马射线暴
to scan the universe
for gamma ray bursts.
5,4,3,2,1
Five, four, three, two, one.
火箭点火, 我们将雨燕送入太空
We have ignition and we have
liftoff of NASA's Swift spacecraft
开始研究和了解宇宙的伽马射线暴
on a mission to study and understand
gamma ray bursts throughout the universe.
这是至今雨燕发现最强伽马射线暴
This is the most powerful gamma
ray burst Swift has detected so far.
耀眼闪光预示宇宙另一端
The flash of light announces
the birth of a new black hole
一个黑洞的诞生
on the other side of the universe.
雨燕对那里的情况也只是以管窥天
Swift can only look at a
fraction of what's out there.
但每天至少探测到一次伽马射线暴
Still, it detects, at least,
one gamma ray burst every day.
这一发现动摇了天文学的基础
That discovery rocked
astronomy to its foundations.
我们一度认为黑洞就像独角兽
We once thought that
black holes, like unicorns,
是永远无法找到的
could never be found.
现在我们相信
We now believe
夜空中可能有数十亿个黑洞
that there are perhaps billions