了解宇宙是如何运行的（2010）

How the Universe Works S05E08

Part 4 April 18, 2021, 7:47 p.m.

It was as if the expanding universe
正在产生粘性的细丝
was producing sticky filaments.
建造新星系的材料
And the materials building new galaxies
就像苍蝇粘在蜘蛛丝上一样粘在这些线上
were sticking to these threads like flies to a spider's silk.
原来这些看不见的细丝就是暗物质
It turns out these invisible filaments are dark matter.
就像是一个暗物质的支架
It's like a scaffolding of dark matter
把普通物质附着到上面去
that was pulling normal matter into it.
当宇宙膨胀时
As the universe expanded,
最初的暗物质团
the original clumps of dark matter
并没有其他团膨胀得那么快
didn't expand as quickly as the rest.
它们像粘糊糊的太妃糖
They stuck together like sticky Taffy
一样粘在一起
with their powerful gravity
强大的引力将它们塑造成细丝
shaping them into filaments.
这些细丝形成了
The filaments formed a sprawling web
一个由暗物质链组成的伸展网
of dark-matter strands,
延伸到整个宇宙
stretching throughout the universe.
这种暗物质网的引力
The gravity of this dark matter web
随后引来的普通物质
then dragged in normal matter,
在这些暗物质丝相遇并聚集的地方
which built up where the filaments meet
最终塌陷形成星系
and eventually collapsed to form galaxies.
较厚的细丝吸收了更多的气体
The thicker filaments pulled in the most gas,
为星系团提供了物质基础
providing the building blocks for galaxy clusters.
它们实际上是沿着这些巨大的细丝
They actually fall along these tremendous filaments
坠落在宇宙中
across the universe,
直径达数亿光年
hundreds of millions of light-years across.
我们所说的是巨大的结构
We're talking about tremendously large structures.
如果没有暗物质，它们就不会存在。
But they would not exist if it weren't for dark matter.
而星系本身
And the galaxies themselves were able to form
也因为这个巨大的结构而得以形成
because of this structure.
如今的星系、恒星和行星
There are galaxies and stars and planets
以及今天在这里的你
and you here today.
都是因为暗物质
That's because of the dark matter
提供了这个结构框架
providing the framework.
布洛克：就像城市中的一个网格系统
Bullock: Just like a grid system in a city defines
定义了建筑物的位置一样
where buildings are going to be,
星系补暗物质定义在宇宙网格系统中
galaxies assemble themselves around the cosmic grid.
地球上的城市规划者
It seems like city planners here on earth
似乎一直在追随宇宙的引导
have been following the lead of the universe,
那些规划者似乎在用道路
except those planners used roads
来代替暗物质
in place of dark matter.
纽约就是最好的例子
New York is the perfect example.
弗里斯：让我们想象一下没有道路的纽约市
Freese: Let's imagine New York City without roads.
没有规划结构，就没有城市基础
There would be no structure, no foundation.
然后整个城市就会分崩离析
Then the whole thing would fall apart.
当人们第一次设计这座城市时
When people first designed the city,
他们铺设了电网
they laid down the grid.
他们修建了道路
They built the roads.
这才是真正的基础
And that was really the foundation.
再后来，他们建造了这些建筑
And then later on, they built the buildings.
就像暗物质网络
Just like the dark matter web
为星系输送
transported the building materials
建筑材料一样
for galaxies,
纽约的道路网也带来了
New York's grid of roads brought the steel
钢铁和混凝土并用来建造城市街区
and concrete to build its city blocks.
是暗物质为你提供了基础
It's the dark matter that gives you the foundation.
它给了我们宇宙的结构
And it gives you the cosmic structure.
在这之后
And then later on,
普通的物质才落入到
the normal matter fell into the galaxies
我们今天看到的星系和星系团中
and the clusters that we see today.
这个新发现的宇宙结构的优雅
The elegance of this newly discovered structure
真让我感到吃惊
of the universe really astounds me.
你有一张暗物质的网
You have this web of dark matter,
它几乎为普通物质
and it almost creates highways for regular matter
建造了一条高速公路让它们落到这些连接点上
to fall into these nexuses.
然后在这里形成最大最亮的星系
And that's where you form the biggest, brightest galaxies.
宇宙学家对暗物质的研究越多
The more cosmologists study dark matter,
就越能看到它
the more they see the crucial role
在塑造我们今天所看到的宇宙中所起的关键作用
it's played in shaping the universe we see today.
但是尽管科学家们
But despite these insights into our origins,
对我们的起源有了这些研究
scientists still don't know
他们仍然不知道暗物质到底是什么
what dark matter actually is.
因为我们无法测量它们，也看不见或感觉不到的它们？
How do you measure something that you can't see or feel?
在过去的50年里
In the last 50 years,
天文学家发现了一些
astronomers have discovered something
关于我们宇宙的不可思议的东西
incredible about our universe.
它由一个叫暗物质的
It's controlled by an invisible puppet master
隐形傀儡大♥师♥控制着
called dark matter.
暗物质创造并组织了
Dark matter created and organized
我们宇宙的大规模结构
the large-scale structure of our universe.
它甚至可能创造了
It may have even created the atoms
组成你身体的原子
that make up your body.
但它仍然是一个谜
But it remains a mystery because we can't see it,
因为我们无法直接看到它
feel it or measure it directly.
感受它或测量它
One of the properties of dark matter
我们确定的是它不会与光相互作用
that we know for sure is that it doesn't interact with light.
它不发光也它不反光
It doesn't shine. It doesn't reflect light.
所以如果你用激光束照射暗物质
And so if you shine, uh, a laser beam on dark matter,
激光束就会直接穿过
the laser beam goes right through.
不会有任何反应
It doesn't do anything.
暗物质这个词
The term dark matter might actually be
实际上可能有点误导人
a little bit misleading.
也许这种物质的真正含义
Maybe the real term for this stuff
是透明物质
is transparent matter.
但不知何故，这听起来不像暗物质那么酷
But somehow that doesn't sound quite as cool as dark matter.
所以，如果我们看不到暗物质
So if we can't see dark matter,
那么为什么科学家们这么肯定它在那里呢？
why are scientists so sure it's there?
我们知道暗物质在那里
We know dark matter's there the same way
就像我们知道很多我们看不见的东西在那里一样
we know many things are there that we can't see.
我们利用引力
We use gravity.
暗物质可能不与光相互作用
Dark matter may not interact with light,
但它与引力相互作用
but it interacts with gravity.
布洛克：只有通过研究恒星的运动
Bullock: It's only by studying the motions of stars,
甚至星系和星系团的运动
even the motions of galaxies and the clustering of galaxies
我们才知道外面有很多额外的物质
do we know that there's a lot of extra stuff
它们的质量
out there that has mass
引导着这些恒星和星系
that's directing these stars
以某种意想不到的方式运动
and galaxies to move in ways that are somewhat unexpected.
第一个发现星系中这种不寻常运动的人
The first person to detect this unusual movement in galaxies
是20世纪30年代的天文学家弗里茨·兹威基
was astronomer Fritz zwicky in the 1930s.
他使用一台定制的18英寸望远镜
Using a custom-built 18-inch telescope,
研究了多个星系
he studied how multiple galaxies interact inside a tight
如何在一组紧密的星系（称为星系团）内相互作用
grouping of galaxies known as a cluster.
弗里茨·兹威基
Fritz zwicky, studying the motions
研究星系和星系团的运动时
of galaxies and clusters.
他发现这些星系
And what he saw is that these galaxies
移♥动♥得太快了
were moving too fast.
所有聚集成团的东西
Every concentration of matter
都具备一个逃逸的速度
has associated with it an escape velocity.
如果你的速度超过了逃逸速度
And if you're moving faster than the escape velocity,
你就不应该再是这个系统的一部分了
you should no longer be a part of that system.
就像火箭在足够快的速度下
Just as a rocket can escape earth's gravity
可以逃离地球引力一样
if it's traveling fast enough,
星系在足够快的速度下
a galaxy should break away from a galaxy cluster
也应该脱离星系团
if it's moving with enough speed.
弗里茨·兹威基注意到彗发星系团中的星系
Zwicky noticed that the galaxies in the coma cluster
移♥动♥的速度应该足够快
should be moving fast enough
完全可以避开邻近星系引力牵引
to escape the gravitational pull of their neighbors.
但是，星系并没有加速
But instead of speeding off
飞向宇宙的其他区域
into different parts of the universe,
而是依然保持在一起
the galaxies remained bound together.
弗里茨·兹威认为一些未知的物质在增加质量