了解宇宙是如何运行的（2010）

How the Universe Works S05E03

Part 3 April 18, 2021, 7:46 p.m.

但黑洞有时间吞噬数十亿颗恒星吗？
that black holes have had time to consume billions of stars?
这似乎不太可能
That seems kind of unlikely.
布洛克: 这似乎说不通
Bullock: It doesn't seem to add up.
我们需要一些其他的方法
We need some other way
来制♥造♥这些超大质量黑洞
to make these supermassive black holes.
问题是，那是什么方法？
And the question is, what is that?
也许我们把这一切弄得太复杂了
Maybe we've been making this all too complicated.
也许要得到一个大黑洞，首先就要从大爆♥炸♥开始
Maybe to get a big black hole is to start big in the first place.
那么黑洞是如何开始变大的呢
So how can black holes start big?
要回答这个问题，科学家们必须
To answer that question, scientists had to journey back
回到宇宙起源的时候
to the very start of the universe,
回到一个被称为黑暗时代的神秘时代
to a mysterious time called the dark ages.
当我们望向宇宙时
As we look out into the universe,
我们看到的时间越来越久远
we're seeing farther and farther back in time.
现在我们来到了
We have now looked back
120亿年前宇宙
over 12 billion years
还是一个婴儿时间宇宙的时候
to the time when the cosmos was still an infant.
我们的发现是一个巨大的惊喜
And what we found was a huge surprise.
我们曾经做过这样的假设
We had made the assumption
当你往宇宙深处看时
that as you look farther out into the universe,
黑洞会变得更小
the black holes would be smaller.
他们没有多少成长的时间
They haven't had much time to grow.
但现在我们发现了一个
But now we've found a 12-billion-solar-mass
120亿太阳质量的黑洞
black hole that's actually less
它实际上距离宇宙不到10亿年
than a billion years into the universe.
这东西是怎么形成这么早的？
How did this thing form so early?
它怎么长得这么快？
How did it grow so fast?
这就像走进产房♥
This is like walking into a delivery room
发现一个100磅重的婴儿
and finding a 100-pound baby.
我是说，这怎么可能？
I mean, how does that even happen?
这简直毫无道理
It doesn't make any sense.
物理学告诉我们，没有哪个黑洞能够吞下足够多的物质
Physics tells us no black hole could swallow enough stuff
以如此快的速度变大
to get that big that quickly.
在宇宙大爆♥炸♥和我们研究这些东西的之间
There really wasn't enough time between the big bang
实在没有足够的时间
and when we're studying these things
让它们仅仅靠吃周围的物质
for them to grow to such large sizes
就能长到这么大
just by eating matter around them.
所以如果没有足够的时间让它们长到这么大
So if there's not enough time for them to grow so large,
也许它们生来就是超大质量的
maybe they're born supermassive.
为了理解这一点，我们必须回到更远的地方
To understand how, we have to travel back even farther,
回到宇宙诞生后不久
to not long after the birth of the universe.
艾斯勒: 早期的宇宙
isler: The early universe was definitely
绝对是一个更紧凑
a much more compact
物质更丰富的地方
and richer place for material.
它更小，密度更大
It was smaller, and it was denser.
已经更接近了温度更热了
Things were much closer. It was hotter.
那是一个非常紧密的地方
It was just a much more intense place to be.
氢气和氦气团聚集在一起
Clouds of hydrogen and helium gas clumped together.
随着云的增大，它们的引力也在增大
As the clouds grew, so did their gravity,
吸进了越来越多的气体
sucking in more and more gas.
最终，这个气体球的密度
Eventually, the ball of gas
变得非常巨大，它崩溃了
became so dense, it collapsed,
最终引发了核聚变
triggering nuclear fusion.
一颗恒星诞生了
A star was born.
这些巨大的第一颗恒星
These massive first stars
被称为星族III
are called population III stars.
因为周围有太多的食物
Because there was so much food around,
这些恒星非常巨大
these stars were huge,
比现在存在的任何恒星都要大很多倍
many times bigger than any stars that exist today.
布洛克: 我们认为很多星族III的恒星
Bullock: We think a lot of these population III stars
可能非常巨大
probably were incredibly massive,
非常短暂，然后就爆♥炸♥了
incredibly short-lived, and just blew up right away.
它们会留下巨大的黑洞
They would've left massive black holes behind.
有了这么多的食物
With so much food available,
这些年轻的、贪婪的黑洞，被称为类星体
these young, ravenous black holes, called quasars,
开始暴食
started binge-eating
变得异常明亮
and became incredibly bright.
数十亿年后，我们仍然可以看到它们的暴饮暴食
Billions of years later, we can still see their gluttony.
这些宇宙中最明亮的物体
The most luminous, bright objects in the universe
被称为类星体
are things called quasars.
这似乎有点讽刺
And it may seem kind of ironic.
但它们实际上是超大质量黑洞
But what these really are are supermassive black holes.
有太多的东西想要把自己塞进黑洞
There's so much stuff trying to cram itself down
所以所有的东西都变得非常热，非常能量大
the black hole that everything gets very hot, very energetic.
你可以在宇宙中清晰地看到它们
And you can see them clear across the universe.
但当我们测量这些年轻类星体的大小时
But when we measured the size of the young quasars,
我们发现它们的质量已经是太阳的数十亿倍
we discovered they were already billions of solar masses.
艾斯勒:在宇宙诞生10亿年之后
Isler: There's not enough time,
没有足够的时间
a billion years after the universe was created,
让它们变成10亿倍太阳质量……
for them to get to a billion solar masses in ...
时间太短了
it's just too short a time.
布洛克: 那么问题就变成了
Bullock: So the question becomes, how do you make black holes
如何在这么短的时间内产生这么大的黑洞？
that are this big in that small amount of time?
我们需要一些其他方法
We need some other way
来扩大这些超大质量黑洞
of growing these supermassive black holes.
一定有其他机制
There needs to be some other mechanism
能让它们这么早产生这么大的质量
that allows them to get that massive so early.
但那是什么呢？
But what is that?
我们可以在早期宇宙中找到线索
A clue can be found in the very early universe.
早期宇宙对我们来说仍然是个谜
The early universe is still so much of a mystery to us.
我们知道当时的情况非常不同
We know that conditions were very different.
这里非常密集还有很多的材料
It was denser. There was a lot more material.
这个时期被称为黑暗时代
This period is called the dark ages.
布洛克:在黑暗时代，我们知道
Bullock: During the dark age, we know
基本上什么都没有发生
that there was basically nothing happening.
有物质存在
Matter existed.
我们认为那里有氢气和氦气
We think that there was hydrogen and helium gas
其他的就不多了
but really not much else.
周围有一些恒星
There were a few stars around,
但没有大到足以形成巨大黑洞的恒星
but nothing large enough to form giant black holes.
但那是巨大的气体云
But there were huge clouds of gas.
因为宇宙很小密度很大
And because the universe was much smaller and denser,
所以云层更厚
the clouds were much thicker.
有一个思路，从这些基本成分
The idea is that from these basic ingredients,
通过重力和气体
gravity and gas,
宇宙建造了巨大的黑洞
the cosmos built massive black holes.
不知何故，宇宙创造了一条
Somehow, the universe has created a shortcut
通往黑洞的捷径
to the black hole.
我们通常认为
We've typically thought of it as,
气体云坍缩成恒星
cloud of gas collapses into a star,
恒星进化，然后死亡，最终留下一个黑洞
star evolves, star dies, leaves behind a black hole.
也许宇宙已经找到了
Perhaps the universe has found a way
跳过恒星阶段
to skip the star phase
直接进入黑洞的方法
and go directly to the black hole.
气体云可能在被称为直接坍塌的过程中
Clouds of gas may have built massive black holes
形成了巨大的黑洞
in a process called direct collapse.
当它们坍缩时，它们甚至没有形成一颗恒星
As they collapsed, they never even formed a star.
它们直接坍缩成一个巨大的黑洞
They just collapsed straight into a giant black hole.
通过直接坍缩理论
Through this direct collapse theory,
你可以形成非常大的黑洞
you can form really big black holes.
想象一下看到这些巨大的气体云
Imagine what it's like seeing one of these giant clouds
直接坍塌成黑洞是什么感觉
of gas collapsing down into a black hole.
你可以这么想：从气体云
You might think you start with, okay,
慢慢坍缩开始，噗的一声
cloud of gas slowly collapsing,
它就是一个黑洞
and, boop, it's a black hole.
但事实并非如此更像是
That wouldn't be the case. It would be more like
巨大的气体云开始坍塌
giant cloud of gas starts collapsing,
然后……啊!……黑洞
then ... aah! ... Black hole.
人们相信，直接坍缩
It's believed that direct collapse
可能会产生
could have created black holes