了解宇宙是如何运行的（2010）

How the Universe Works S05E08

Part 5 April 18, 2021, 7:47 p.m.

Zwicky thought some unknown material was adding mass
因此，额外的重力作用于星系系统
and, therefore, extra gravity to the system,
使星系保持在原来的位置
holding the galaxies in place.
也许有一些额外的东西
Maybe there's something extra there
提供了比我们所看到的
that's providing more gravity
推算出来的引力更大
than we can account for based on what we see.
但在当时，弗里茨·兹威
At the time, zwicky's ideas
关于这种无法解释的超重力来源的设想
for this unexplained source
一直没有受到重视
of extra gravity fell on deaf ears.
弗里茨·兹威是一个很不讨人喜欢的家伙
Zwicky was a very unlikable fellow and,
我想，呃，这激怒了他的许多同事
I think, uh, infuriated many of his colleagues.
这也许是他们不愿意接受
And that perhaps was one another reason
他的建议的另一个原因
why they were less willing to accept his suggestion.
也许还有另一个原因
The other is that I think he was so far ahead
我认为他已经远远领先于同时代的其他科学家
of his time as a scientists
以至于科学届的其他科学家
that it just took time
需要是花了一些时间才赶上
for the rest of the community to catch up.
又过了30年
It took another 30 years
天文学家维拉·鲁宾的一项重要发现
and a crucial discovery by astronomer Vera rubin
使暗物质进入了教科书
before dark matter made it into the text books.
维拉·鲁宾正在观察星系本身
Vera rubin was looking at galaxies themselves.
现在我们知道，星系是气体、恒星和尘埃的集♥合♥
Now, galaxies are collections of gas and stars and dust.
它们有一个整体的运动
And they have an overall motion.
我们的银河系是一个圆盘
Our milky way galaxy's a disc.
这个圆盘围绕着星系的中心移♥动♥
And that disc is moving around the center of the galaxy.
布洛克：我们以为银河系中♥央♥的恒星
Bullock: The stars in the middle of the galaxy you expect
绕行的速度会很快
to go around very fast.
而银河系外♥围♥的恒星比如太阳
And the stars at the outskirts of the galaxy,
绕行的速度会比较慢
you expect to go around very slowly,
就像太阳系内部行星绕太阳转得很快
just like the inner planets go around the sun very quickly
而外行星绕太阳转得慢得多
and the outer planets go around the sun much more slowly.
她发现，银河系的外♥围♥
What she found is that the outskirts of the galaxy
与内部更近的部分竟然
were spinning around the galaxy
以相同的速度围绕着银河系旋转
at the same speed as parts that were closer in.
这完全说不通
And that didn't make any sense.
银河系中的恒星似乎是固定的
The stars of the galaxy appeared to be fixed,
几乎像是粘在一个巨大的旋转轮上
almost as if they were glued to a giant spinning wheel.
布洛克：唯一可能的办法是
Bullock: And the only way that can be is
如果那里有一些额外的重力
if there's some additional gravity there,
一些额外的物质
some additional stuff there that's adding mass,
增加了质量、增加了引力
that's adding gravity, that's making those
这使得那些外侧恒星运行得更快
outer stars go faster.
唯一的结论是
The only conclusion was that the spinning wheel
旋转的星系受到了非常巨大的
was being affected by something very massive
但又完全看不见的东西的影响
and completely invisible.
当天文学家转动他们的望远镜
When astronomers turn their telescopes
亲自观察这个
to see for themselves
看不见的质量是否是真的时
if this invisible mass was real,
他们几乎在他们所看到的任何地方都找到了证据
they found evidence for it almost everywhere they looked.
随着越来越多的人做了他们所做的事情
As more and more other people were able to replicate
人们开始意识到
what they had done, people started to realize,
“哇哦。你知道吗？弗里茨和维拉是对的
"whoa. You know, Fritz and Vera were right.
这些奇怪的东西确实存在”
This weird stuff is really out there."
而且不仅仅是一点点
But there's not only just a little bit.
我们所能看到的每个星系
Every galaxy we can see, essentially,
本质上都是由暗物质控制的
is dominated by dark matter.
现在，我们知道暗物质就在那里
Now, we know that dark matter is out there.
但我们还没搞清楚它们到底是什么
But we're still no closer to working out what it actually is.
我们认为它可能
We think it may be a particle called a wimp.
是一种叫做大质量弱相互作用的粒子
But it could be a whole family of particles
但它可能是形成暗原子
that forms dark atoms and dark molecules.
和暗分子的一整套粒子
Perhaps an entire dark universe is out there,
也许整个黑暗的宇宙就在那里
filled with invisible dark planets
充满了看不见的黑暗行星
and illuminated by the dark light
并被它们的暗星的暗光照亮
of their dark stars.
科学家们正在努力
Scientists are struggling to uncover
揭开暗物质的真实身份
the true identity of dark matter.
迄今为止，最佳的候选粒子是
To date, the best candidate
一种叫大质量弱相互作用的理论粒子，简称wimp
is a theoretical particle known as a wimp.
但由于粒子能像幽灵一样
But because wimps can pass through
穿过普通物质
ordinary matter like a ghost,
研究人员一直空手而归
the researchers have been left empty-handed.
不仅暗物质现在可以穿过我
Not only could dark matter be going through me right now,
而且几乎可以肯定的是
but it almost certainly is
我们只是没有注意到它
and I'm just not noticing it.
这就是为什么
And this is why we're building
我们在地球上建造这些非常奇特的探测器
these very fancy detectors here on earth,
试图捕捉它们
（其中就有中国发射的“悟空”号♥探测器 ——译者注）
to try to catch them.
在科学家们能够真正捕捉并分♥析♥vimp之前
Until scientists can capture
尚无定论
and analyze a wimp, all bets are off.
泰马克：wimp理论的主要挑战是
Tegmark: The main challenge for the wimp theory is
我们还没有找到任何wimp
that we simply haven't found any wimps yet.
我们一直在努力寻找
And we've been looking pretty hard for ...
多年以来始终未果
for a lot of years. And pretty soon,
事情就会变得很尴尬
it's gonna start to get embarrassing.
也许暗物质不是由wimp构成的
Perhaps dark matter isn't made of wimps.
也许组成暗物质的物质
Perhaps the stuff that makes up dark matter
比我们想象中的
is stranger and more complex
更奇怪更复杂
than we ever thought possible.
我们知道普通物质有许多不同的形式
We know that regular matter comes in many different forms.
有电子和质子，中子，夸克
There are electrons and protons,
所有这些的各种粒子
neutrons, quarks, all of those.
为什么我们要假设只有一种暗物质？
Why should we assume there's only one kind of dark matter?
我们的方法可能全错了
Our approach could be all wrong.
与其寻找单一类型的粒子
Instead of looking for a single type of particle,
还不如寻找一个完整的暗物质粒子动物园
there could be an entire zoo of dark matter particles.
普通物质的粒子相互作用
Particles of ordinary matter interact
形成原子和分子
with each other to form atoms and molecules,
这些我们都能接触和看到的东西
the stuff we touch and see.
如果暗物质是由不同的粒子组成的
If dark matter is made from different particles,
它也可以这样做
it could do the same,
相互作用并形成暗物质的暗原子
interacting and building dark atoms of dark stuff,
甚至可能是一个由暗物质组成的宇宙
perhaps even a universe of dark materials.
如果我们能证明暗物质与自身相互作用
If we can show that dark matter interacts with itself,
那就意味着它们实际上可能是暗物质星系
that means their really could be dark matter galaxies,
暗物质恒星、暗物质行星
dark matter stars, dark matter planets
和我们周围的暗物质人
and people all around us right now
而我们现在还不知道
that we were not aware of.
这个虚幻的暗物质宇宙真的存在吗？
Could this shadowy dark universe really exist?
2012年，钱德拉X射线望远镜
In 2012, the chandra X-ray telescope
向天文学家提供了暗物质
gave astronomers the first clue
是否相互作用的第一条线索
to whether dark matter interacts.
望远镜观测到了两个星系团的碰撞
The telescope observed the collision
每个星系团
of two galaxy clusters,
都挤满了数百个星系
each packed with hundreds of galaxies.
天文学家希望看到
Astronomers hope to see what would happen
星系团内部的暗物质会发生什么
to the dark matter inside the clusters.
会不会有互动的迹象？
Would it show any signs of interacting?
当这些星团碰撞时，暗物质会做什么？
What does the dark matter do when these clusters collide?
好吧，这是个大问题
Well, that's the big question.
当星团聚集在一起时
When the clusters come together,
暗物质是撞击并拖动
does the dark matter smack and drag
还是直接穿过
or does it go right on through?
如果我们能测量出这种差异
If we can measure that difference,
我们就能知道暗物质自身是否相互作用？
we can tell does the dark matter self-interact or not?
当这些星系彼此穿过时
The galaxies pass through each other.
有些东西被留下了
But something is left behind:
一团混乱的暗物质
A tangle of dark matter.
看起来有一些额外的暗物质
It looks like there's some extra dark matter
留在了中间
that's been left behind in the middle.