了解宇宙是如何运行的（2010）

How the Universe Works S10E01

Part 2 Aug. 5, 2022, 5:04 p.m.

早期的宇宙非常热
The very early universe was
super hot,
能量非常高，普通的物质粒子
super energetic,
and regular particles
运动速度非常快
of matter were zipping around
so fast
甚至连引力都无法将它们聚集在一起
that not even gravity
could hold them together.
但常规物质并不是宇宙早期的
But regular matter wasn't
the only thing
唯一物质
in the early universe.
在大爆♥炸♥时期环境中
In the background,
gravity is working
引力作用于其他东西——
on something else --
普通物质的幽灵表亲
Regular matter's ghostly cousin,
也就是我们今天所知的暗物质
the invisible substance
known today as dark matter.
它构成了早期宇宙中
It makes up about 85 percent
of all the matter
产生的所有物质的85%
created in the early universe.
正常物质和暗物质
Normal matter and dark matter
both existed
都存在于大爆♥炸♥时期，但它们的发展方式
around the time of the Big Bang,
but they way they played out
却截然不同
was very different.
大爆♥炸♥10秒后
Just ten seconds after
the Big Bang,
婴儿宇宙的温度达到了数十亿华氏度
the infant universe is
billions of degrees Fahrenheit,
对于普通物质粒子来说这个温度非常高
still far too hot for
regular matter particles
它们无法聚集在一起，但暗物质却遵循着不同的规则
to clump together, but dark
matter plays by different rules.
暗物质不会像普通物质那样
Dark matter isn't affected by
the Big Bang's intense
受到大爆♥炸♥的强烈辐射的影响
radiation in the same way
that regular matter is,
因此，暗物质能够冷却下来
and so because it's able
to cool,
它会以普通物质不同的方式聚集在一起
it clumps together in a way
that regular matter doesn't.
随着暗物质团块的增长
As dark matter clumps
grow, they exert
它们会产生引力并开始形成阴影结构
a gravitational pull and begin
to form shadowy structures.
一旦暗物质站稳脚跟
As soon as the dark matter
gets a foothold,
我们就有了一个地方，那里有更多的物质
we have a place where there's
a bit more stuff,
然后吸引越来越多的暗物质
then that attracts
more and more dark matter.
大爆♥炸♥38万年后
380,000 years after
the Big Bang,
高温下降到几千度
the intense heat drops
to a few thousand degrees.
正常的物质粒子运动开始变慢
Normal particles of matter
move around more slowly.
质子和电子结合在一起
Protons and electrons bind
together and form
形成氢原子和氦原子
atoms of hydrogen
and helium gas.
然后暗物质的引力开始作用于
Then gravity from dark matter
starts to work
普通物质
on regular matter.
在意识到这一点之前，已经有了一个
Before you know it,
you have this very clumpy
非常笨拙的宇宙，它有着巨大的暗物质晕
universe with these huge
dark matter halos
并且已经可以开始以气体的形式
that can now start to draw in
also ordinary matter
吸收普通物质
in the form of gas.
一个持续了十亿年的建筑工程开始了
A billion-year building
project begins.
暗物质团块拉入气体云…
The dark matter clumps
pulled in clouds of gas...
它是宇宙网和星系的基础
the foundations of
the cosmic web and the galaxies.
就像你建一座大楼一样
Just as when you build
a building, you know,
在大楼建成之前要做很多工作
there's a lot of work that
happens before
我们的宇宙
the building goes up,
our universe spent
花了很多时间为这个宇宙网
a lot of time laying
the groundwork for
奠定基础然后才打开灯
this cosmic web before
it switched on the lights.
地基已经完成
The foundations
are complete,
但工作还没有完成
but the job isn't finished.
这些气体云是如何转变成
How did those clouds of gas
transform into the greatest
宇宙中最大的结构？
structure in the universe?
将气体聚集在一起的神秘暗物质
he secretive dark matter
that brought the gas together
同时也在管理着建造过程
is also on site,
managing the build.
实际上，是暗物质在宇宙聚集中
It was really the dark matter
that called the shots
起了决定性作用，因为
in cosmic clustering,
because it outweighed
它比普通物质要重要得多
the ordinary stuff by
a big factor.
从本质上说，宇宙网是由暗物质构成的
In essence, the cosmic web
is made of dark matter.
卷起物质的触须在宇宙中伸展开来
Tendrils of material are
stretched out across the cosmos.
随着这个庞大结构的形成
As the sprawling structure
builds, its gravitational
它的引力在增强，吸引了更多的暗物质
pull strengthens, pulling in
more dark matter.
这些团块开始坍塌并收缩成细丝——
The clumps begin to collapse
and shrink down
它们在更紧密的团簇中相遇
into filaments -- these meet
at even more tightly
形成了一个巨大、黑暗的支架
packed clusters, creating
a huge, dark scaffold
并可以吸入更多的氢气
that drags in more hydrogen gas.
布洛克:想象一下蜘蛛网上的露珠
BULLOCK: Imagine drops of dew
on a spider web.
这就像氢气被吸进了
That's like hydrogen blobs
being pulled in
暗物质的宇宙网
to dark matter's cosmic web.
经过数千万年的形成
After tens of millions
of years of construction,
气体束延伸到整个宇宙
strands of gas stretch
across the cosmos.
一直到现在——蜘蛛网
Fast forward to now --
The web appears
闪耀着壮丽的星光，被星系所照亮
in all its star-spangled glory,
lit up with galaxies.
我们知道，在某个时刻，恒星和星系形成了
We know at some point,
stars and galaxies formed.
现在最大的问题是——第一个星系
The big question is when --
What were the first
是什么样子的？这是一个很大的谜团
galaxies like?
That's a big mystery.
那么宇宙之光是如何开启的呢？
So how then did the lights
of the cosmos switch on?
有证据表明，当宇宙聚集起
Evidence suggests that as
the universe assembled its web
暗物质和氢气的网时
of dark matter and hydrogen gas,
曾经存在过的最大的恒星
the biggest stars that have
ever lived
点燃了宇宙
set the cosmos ablaze.
2018年，科学家们研究了一个
2018, scientists study
an ancient galaxy,
名为MACS1♥1♥4♥9-JD1的古老星系
the catchily named MACS1♥1♥4♥9-JD1.
在那里，他们发现了一些迄今为止被探测到的
There, they find some of
the oldest stars
最古老的恒星
ever detected.
这个特殊的星系令人兴奋
This particular galaxy is
exciting, because it's
因为它是在大爆♥炸♥后很短的时间内就形成了恒星
forming stars just a very
short time after the Big Bang.
这些恒星可能提供了一条线索
Those stars could hold
clues as to how
关于支撑宇宙的宇宙网
the cosmic web that supports
the universe
最初是如何点亮的恒星的
first lit up,
but as astronomers study
但当天文学家研究宇宙中
starlight from when
the universe was just
仅2.5亿年的星光时，他们受到了冲击
250 million years old,
they get a shock.
恒星不只是由大爆♥炸♥中
The stars are not just
made up of hydrogen
产生的氢和氦组成
and helium produced