了解宇宙是如何运行的（2010）

How the Universe Works S05E03

Part 4 April 18, 2021, 7:46 p.m.

质量高达太阳一百万倍的黑洞
up to a million times the mass of the sun,
比单个恒星坍缩产生的黑洞
much bigger than from the collapse
要大得多
of a single star.
布洛克:这些早期的黑洞
Bullock: These early black holes
有点像从未存在过的星系
are sort of like the galaxies that never were.
以为它们会形成星系
They were gonna make galaxies.
但相反，它们坍缩成了巨大的黑洞
But instead, they collapsed into very massive black holes.
为了直接坍缩形成黑洞
For direct collapse to form a black hole,
需要精确的条件
the conditions need to be precise.
云一定是非常对称的
The clouds must be very symmetrical,
形成一个平滑的球
forming a smooth ball.
如果你有一个气体球，它不完全是一个球
If you have a ball of gas that isn't quite a ball,
它不完全均匀
that's not quite homogeneous,
当它坍塌时，它会扯成碎片
as it collapses, it'll fragment.
它会分♥裂♥成不会形成黑洞的物体
And it'll fragment into objects that won't form black holes.
所以你要让它足够热
So you want it to be hot enough
并保持一个巨大的物体
that it stays one big, giant thing.
但它确实需要冷却一点，对吧
But it does need to cool a little bit, right,
这样你就能让它自己塌下来
so that you get it to collapse in on itself.
你必须让大量的氢气
You have to get uniform collapse over time
也就是宇宙的原始物质
of a very large amount of hydrogen gas, presumably,
随着时间的推移而均匀坍缩
which is the original matter in the universe,
在不到5亿年的时间内
collapsing spherically symmetrically,
以球对称的方式坍缩
without fragmenting,
而不会碎裂
over a period of less than 500 million years.
直接坍缩可能会产生
Direct collapse may have created black holes
质量是太阳一百万倍的黑洞
a million times the mass of the sun.
但它不能完全解释
But it can't completely explain
我们在早期宇宙中看到的120亿个太阳质量的
the 12 billion solar-mass supermassive black holes
超大质量黑洞
we see in the early universe.
也许巨大的超大质量黑洞是由
Maybe gigantic supermassive black holes were created
奇怪的、看不见的力量产生的
by strange, unseen forces.
也许它们是由
Maybe they were created
神秘的黑暗宇宙创造的
by the mysterious dark universe.
天文学家在深入研究早期宇宙时
Astronomers looking deep into the early universe
发现了巨大的超大质量黑洞
have discovered gigantic supermassive black holes.
布洛克:这是一个很大的谜团
Bullock: This is a pretty deep mystery.
存在于宇宙早期的
There are these supermassive black holes
超大质量黑洞
that exist in the very early universe.
大家都说，他们不应该存在
And by all accounts, they should not exist.
根据正常的物理定律
According to the normal laws of physics,
它们不可能
it shouldn't have been possible
长得这么大，这么快
for them to grow so big so quickly.
对于天体物理学家来说，了解黑洞
For astrophysicists, understanding how black holes
如何发展到如此之大是我们最大的谜团之一
have grown to be so large is one of our biggest mysteries.
布洛克:我们需要一些其他方法
Bullock: We need some other way
来培育这些超大质量黑洞
of growing these supermassive black holes.
一定有其他机制能让它们
There needs to be some other mechanism
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?
我们在夜空中看到的
Everything we can see in the night sky
一切物质
makes up just 4.8%
只占宇宙物质的4.8%
of all the matter in the cosmos.
剩下的就是黑暗的宇宙
The rest is the dark universe,
包括暗物质
including dark matter.
我们不能直接看到它，感觉到它，或者探测到它
We can't see it, feel it, or detect it directly.
但我们知道暗物质是存在的
But we know dark matter is there.
它的引力拉着它周围的一切
Its gravity is tugging on everything around it.
我们开始了解
And we're beginning to understand
它在宇宙形成过程中
it plays a fundamental role
扮演着重要的角色
in the formation of the universe.
大多数靠引力聚集在一起的物质
Most of the stuff that collects together
是暗物质
gravitationally is dark matter.
所以也许黑洞
So perhaps black holes form
是以某种方式与暗物质一起形成的
somehow with the inclusion of dark matter.
从一个角度来看，暗物质的数量
One way of looking at it is there's six times
是普通物质的6倍
as much dark matter as normal matter.
所以，如果黑洞能够利用
So there's six times as much food out there
这些黑暗的东西，那么
for the black holes to eat
它们可以吃的食物就是原来的六倍
if they're able to tap into this dark stuff.
也许这些超大质量的黑洞是通过
Maybe these supermassive black holes are growing
吞噬暗物质来成长的
by eating dark matter.
这里有一些诱人的线索
There are some tantalizing clues.
最大的超大质量黑洞
The largest supermassive black holes
并不存在于规则物质最多的星系中
don't live in the galaxies with the most regular matter.
它们生活在暗物质最多的星系中
They live in the galaxies with the most dark matter.
关于暗物质，我们现在所知道的一件事
The one thing we know about dark matter right now
就是它有引力
is that it has gravity.
而黑洞是靠引力运行的
And a black hole runs on gravity.
它会吸引任何有质量的物体
It attracts anything with mass.
所以没有理由认为
So there's no reason to assume
黑洞只是吃普通的物质
that black holes would only eat regular matter.
现在我们知道，宇宙中还有更多的暗物质
And now we know that there's far more dark matter out there.
也许暗物质在帮助黑洞进食
Maybe dark matter helps the black holes eat.
也许在某种程度上，暗物质是
Maybe in some ways, dark matter is a feeder
这些超大质量黑洞的食物来源
for these supermassive black holes.
也许真正形成超大质量黑洞的
Perhaps what really grows a supermassive black hole
是所有被它周围的暗物质
is all of the regular matter being directed into the center
引导到中心的常规物质
by the dark matter around it.
也许是暗物质强大的引力
Maybe the dark matter's powerful gravity
将普通物质
sucks in regular matter
吸进黑洞
and funnels it into the black hole.
从某种意义上说，暗物质在给黑洞加油
In a sense, the dark matter is greasing the wheels.
有点像把桌子向上倾斜
It's sort of tilting the table up
这样食物就能直接滑进去
so that that food can slide right in.
但现在科学家们认为，暗物质
But now scientists think the dark matter
可能通过点燃暗恒星
may create gigantic black holes directly
直接创造出巨大的黑洞
by igniting dark stars.
一些人认为暗物质
Some believe that dark matter
激发了早期宇宙的超级恒星
sparked early universe super stars.
当它们死亡时，会留下超大质量的黑洞
When they die, they leave behind supermassive black holes.
暗星听起来像
Dark stars sound like
是来自某些科幻作家
they come from the fertile imagination
丰富的想象力
of some Sci-Fi writer.
但是 Katie freese 博士认为它们可以解释
But Dr. Katie freese believes they may explain
为什么早期超大质量黑洞增长如此之快
how early supermassive black holes grew so fast.
“暗星”真的很神奇
Dark stars are amazing.
所以，当我们第一次有了这个想法
So, when we first had this idea,
我们很快就兴奋起来
we got excited really quickly,
因为这是一种以前
because this is a new type of star
从未见过的新型恒星
that has never been seen before.
暗星可能是宇宙中最早形成的
Dark stars may have been some of the first stars
一些恒星
to form in the universe.
它们是在
They sparked into life
宇宙只有2亿年的时候诞生的
when the universe was just 200 million years old.
但暗星是如何形成质量巨大的黑洞的呢？
But how could dark stars form really massive black holes?
新生黑洞的重量不会超过它的母恒星
A newborn black hole can't weigh more than its parent star.
所以为了产生一个巨大质量的黑洞
So in order to give birth to a really massive black hole,
母恒星也必须是超大质量的
the parent star has to be supermassive, as well.
弗雷斯:这些早期的物体真的很奇怪
Freese: These early objects are really strange.
他们很酷
They're very cool.
它们真的非常非常大
And they're really, really big.
这些东西的大小是
The size of these things is 10 times the distance
太阳到地球距离的10倍
between the sun and the earth.
但这怎么可能呢？
But how is that possible?
普通恒星有一个尺寸上限
Regular stars have an upper size limit.
恒星是引力向内推动
A star is a battle between gravity pushing inwards
和核聚变向外推动之间的一场战斗
and nuclear fusion pushing out.
当恒星变得太大时
When the star grows too big,
它的引力就会变得势不可挡
its gravity becomes overwhelming.