了解宇宙是如何运行的（2010）

How the Universe Works S05E08

Part 2 April 18, 2021, 7:47 p.m.

充满的原始气体是如何聚集在一起
that filled the early universe clump together
并最终形成第一批恒星的
to form the first stars.
这个谜团始于宇宙开始爆♥炸♥
The mystery begins when the universe
还不到一秒的时候
is less than a second old.
它突然爆♥炸♥膨胀
It suddenly expands.
在十亿亿亿亿亿分之一秒的时间内（普朗克秒）
In a period of about a millionth of a billionth
我们的宇宙体积
of a billionth of a billionth of a second,
膨胀了10的90多次方倍
our universe puffed up
宇宙的体积从单个原子的大小
by over 90 orders of magnitude in volume
变成了篮球的那么大
and went from the size of a single atom
而时间只是一秒的
to the size of a basketball
一小部分的一小部分的一小部分
（从宇宙大爆♥炸♥到现在所有经历的
秒数还没有一秒内的普朗克秒数多
前者简直是个很小的数字
4.3E18 / 1E43 ——译者注）
这种快速膨胀产生了
This rapid expansion creates
一个巨大的均匀分布的粒子辽阔海洋
a vast sea of evenly spread particles,
这些粒子冷却后形成氢和氦原子
which cool to form atoms of hydrogen and helium,
这些气体有朝一日
the gases that will one day collapse
会在万有引力的作用下崩塌
under the force of gravity
成为第一批恒星
to become the first stars.
但还有个问题
But there's a problem.
早期宇宙中的气体
The gas of the early universe
分布太均匀
is too evenly spread,
太平滑
too smooth for gravity
引力不足以拉动某些部分
to pull on some parts more than others
并触发气体区域崩塌和聚集
and trigger regions of the gas to collapse and clump.
如果宇宙是完全平滑的
If the universe was completely smooth,
那么它将是美丽而乏味的
it would be beautiful but boring because no ...
因为我们看不到任何东西
nothing would exist that we could see.
一定有什么东西导
Something must have made
致了平滑的气体海洋
the smooth sea of gas collapse
崩塌并形成了第一批恒星
and build the first stars,
一种奇异的在微小尺度上打破平衡的东西
something weird operating on the tiniest of scales.
有一点很有趣
One thing that really is interesting about that
在很小的范围内
is that on very small scales,
由于海森堡不确定性原理
due to the Heisenberg uncertainty principle,
导致了奇怪的事情发生了
strange things can happen.
当我们看到一辆汽车、一个跑步者、甚至一个宇宙飞船时
When we see a car, a runner or even a spacecraft,
我们能计算它们的运动量
we can calculate their motions.
在新生宇宙的微微量子世界里
In the tiny quantum world of the infant universe,
不存在这种确定性
that certainty is missing.
没有什么东西有明确的动量或位置
Nothing has a definite momentum or position.
由于没有任何东西被锁定在固定的位置
And because nothing was locked in place,
在膨胀的宇宙中
fluctuations or grooves
可能会出现波动或沟槽
could develop in the expanding universe.
当宇宙迅速膨胀时
And when the universe inflated rapidly,
这些波动会在某些地方固定
these fluctuations because frozen in place,
于是就会形成致密的点
creating dense points around
围绕这些点的气体云就可能会崩塌
which the gas clouds could collapse,
就像形成恒星的引力种子一样
acting like gravitational seeds for star formation.
幸运的是，这些微小的种子波动
Fortunately, there were these tiny seed fluctuations,
就像一种宇宙DNA
which acted like a kind of cosmic DNA,
决定着结构层在哪里
determining where and when
什么时候以及如何成长为恒星、
and how the structural layer grew into the stars,
行星和我们在当今世界看到的
the planets and all the other awesome structure
所有其他令人敬畏的结构
we see around us in today's world.
我认为这是所有科学中
I think it's one of the most beautiful ideas
最美丽的观点之一
of all of science, that something
像海森堡不确定性原理
like the Heisenberg uncertainty principle,
我们认为它只适用于量子力学中的微小事物
which we thought applied only to tiny things
但最终却决定了
in quantum mechanics, ultimately is responsible
我们所知的宇宙中
for the biggest structures
最大的结构
that we know of in the cosmos.
所以谢谢你，海森堡
So thank you, Heisenberg.
涨落的发展
The development of the fluctuations
似乎解开了宇宙结构
seems to solve the mystery of
演变的谜团
how the universe evolved its structure.
但还是有一个问题
But there's another problem.
如果你计算一下
If you do the math,
仅仅只是气体的质量
the mass of gas alone
并不能产生足够的引力
doesn't pack enough gravity
来创造我们今天在宇宙中
to create all the stars
看到的所有恒星
we see in the universe today.
一定是别的什么东西
Something else must have added mass
给坍塌的气体云增加了质量
to the collapsing gas clouds.
这种东西有可能是暗物质吗？
Could that something have been dark matter?
今天，宇宙学家正在努力解决
Today, cosmologists are grappling
一个令人费解的悖论
with a puzzling paradox,
曾经充满宇宙的气体为什么能够如此迅速地崩塌
how did the gas that once filled the universe collapse so quickly
并形成我们今天看到的恒星的？
to form the stars we see today
而当时还没有如此足够的气体
when there wasn't enough gas to begin with?
唯一的答案是
The only answer: Something other than normal matter
一定有一些非正常物质存在
must have been out there,
给气体云增加了质量
adding mass to the gas clouds,
并帮助它们坍缩成恒星
helping them collapse into stars.
如果只有正常物质
If you only have the normal matter,
那么结果就是，事情的发展不可能这么快
it turns out things just don't grow fast enough.
宇宙就不会形成现在的结构
You don't have enough structure in the universe.
我们可以计算出
We can calculate that there wouldn't have been enough time
自宇宙诞生以来
since the beginning of the universe
没有足够的时间让正常物质
for normal matter to collapse to form galaxies,
崩塌形成星系、恒星、行星和人类
stars, planets and people.
许多科学家现在认为
Many scientists now believe
加速恒星形成的额外推动力
the extra push speeding up the formation of stars
是看不见的暗物质的引力
was the gravity of invisible dark matter.
尽管暗物质和正常物质
Even though dark matter and normal matter
不能直接相互作用
can't really interact directly,
但它们确实通过引力相互作用
they do interact via gravity.
这对我们的存在
And it turns out that is
至关重要
critically important to our existence.
如果把暗物质放进去，一切就都顺理成章了
If you put that dark matter in, everything works out.
这样我们就能让宇宙运转得很好
And it's really kind of amazing how well, uh,
这真的很神奇
we can make the universe work.
随着早期宇宙的膨胀，温度逐渐降低
As the early universe expands, it also cools.
现在这里是氢气和氦气的海洋
It's now a sea of hydrogen and helium gas.
周围还有很多暗物质
There's also lots of dark matter around,
它们聚集在
which is built up in the fluctuations or grooves
膨胀宇宙的起伏或凹槽中
in the expanding universe,
形成了强引力区域
creating regions of high gravity.
特格马克：暗物质
Tegmark: The dark matter was free to actually start doing
可以自♥由♥地以自己的方式运作
its own thing and started growing its patterns
并在普通物质之前开始增长和聚集
and its clustering before the ordinary matter did.
这就是为什么暗物质在
And that's why dark matter
在创造我们今天生活着的
actually played such a key role in ...
这个更有趣的宇宙的过程中
in creating this much more interesting universe
起着至关重要的作用
that we live in today.
这些暗物质团的引力
The gravitational pull of these clumps
牵引着氢和氦元素
of dark matter drags in huge clouds
并聚集成巨大的云团
of hydrogen and helium.
云团就变得越来越紧密
The clouds get denser and denser
直到它们引发核聚变
until they trigger nuclear fusion.
我们宇宙中的第一批恒星由此诞生
And the first stars in our universe are born
就都要感谢暗物质
thanks to dark matter.
他们先聚集在一起
It clumped and collapsed.
这会吸引所有正常的物质都掉入其中
And that would later allow all the normal matter to fall in.
暗物质是形成恒星、黑洞、行星的
Dark matter is what gave the initial kick to form stars,
最初动力
black holes, planets,
当然也包换外星人，人类和其他一切
aliens, people and everything else.
你必须明白暗物质
You really have to understand that dark matter
是宇宙中占据统治地位的物质
is the dominant form of matter in the universe.
在宇宙的最开始的时候