了解宇宙是如何运行的（2010）

How the Universe Works S08E07

Part 5 Jan. 30, 2022, 2:59 p.m.

如果这是我们宇宙法则运作的领域
If it is the realm where the
laws of our universe operate,
那么这些域墙本质上就是宇宙的年龄
then these domain walls are in
essence the age of the universe.
但这些都只是理论
Narrator:
But this is all just theory.
如果我们真的想弄清楚
If we ever really are
to work out
宇宙真实的大小和形状
what the true size
and shape of the universe is,
我们就必须寻找离我们很近的线索
we're going to have to look
for clues that are close to us.
这些线索可以回答终极问题
Narrator: Clues that could
answer the ultimate question,
更大的宇宙的其余部分有多大
how big is the rest
of the greater universe
它能永远持续下去吗？
and could it go on forever?
♪
narrator:
数万年来
For tens of thousands of years,
人类一直惊叹于浩瀚的宇宙
mankind has gazed in wonder
at the vastness of the cosmos,
但宇宙究竟有多广阔呢？
but just how extensive is it?
如果我们能回答这个问题
If we could answer
that question,
它可能会帮助我们理解我们在宇宙中的位置
it might help us to understand
our place in the universe.
科学上的一个基本问题是
One of the fundamental
questions in science
宇宙有多大？
is how big is the universe?
为了回答这个问题，“宇宙有多大？”
O'dowd: To answer the question,
"how big is the universe?"
我们必须回答这个问题，宇宙是什么形状的
we have to answer the question,
"what shape is the universe?"
我说的形状，是指几何形状
and by shape, I mean geometry.
我的意思是，宇宙在最大的尺度上是如何弯曲的？
I mean, how is the universe
curved on its largest scales?
萨特:如果我们要发现宇宙
Sutter: If we are to discover
that the universe
确实有某种几何曲率
does have some
sort of geometric curvature,
那么这可能意味着它在难以置信的距离内
then this might imply that it
wraps around in on itself
将自己包裹起来
over incredibly large distances.
如果你能沿着一个方向运动足够长的时间
And that if you could travel
in one direction long enough,
你就会在你的起点结束
you would end up
at your starting point.
另一种说法是，宇宙
Another version is
that the universe
更像是一个无限大的平面
is more like
an infinite flat plane.
好吧？根本没有曲率
Okay?
No curvature at all.
你走得越远，嗯，当你走得越远
The further you travel,
well, the further you get
你就再也回不到起点了
and you never get back
to where you started.
为了计算出物体的形状
Narrator: To work out the shape
of something,
我们通常会退一步看一看
we would normally just step back
and take a look.
但很明显，离开宇宙是不可能的
But clearly moving outside
the universe is a nonstarter.
布洛克:你不可能跳上火箭
Bullock:
You can't jump on a rocket
飞到比我们的宇宙视界大一千倍的地方
and fly a thousand times larger
than our cosmic horizon
去看看宇宙的形状
and see what the shape
of the universe is.
人不能，至少不应该
We just can't do that.
塞勒:我们人类对更大宇宙的看法
Thaller: Our human perspective
on the larger universe
是如此有限
is so limited.
所以如果我们想知道宇宙更大的形状
So if we want to figure out
what the larger shape
和规模是什么
and scale of the universe is,
我们必须非常聪明
we're going to have to be
very clever indeed.
聪明的一个方法是
Narrator:
One way to be clever
用最简单的术语来思考
is to think of the geometry
of the universe
宇宙的几何结构
in its simplest terms.
布洛克:当我们谈论宇宙的几何时
Bullock: When we talk about
the geometry of the universe,
我们真的是在谈论几何
we really are talking
about geometry.
为了思考几何，你必须采取措施
In order to do geometry,
you have to take measures.
你需要一个宇宙之尺来做这个
You need a cosmic ruler
to do this,
事实证明有一个伟大的宇宙之尺
and it turns out
there's a great cosmic ruler
叫做重子声学振荡
known as baryon
acoustic oscillations.
重子声学振荡是
Narrator: Baryonic acoustic
oscillations are ripples
宇宙微波背景中的波纹
in the cosmic
microwave background,
这是宇宙中最古老的光
the oldest light
in the universe.
随着宇宙的膨胀
As the universe expanded,
这些波纹以一种统一的方式在空间中留下印记
these ripples were imprinted
in space in a uniform way.
它们提供了一个宇宙尺
They provide a cosmic ruler
来测量随着时间推移的巨大距离
to measure vast
distances over time,
所以我们可以测量宇宙是在弯曲的空间
so we can gauge
if the universe expands
还是在平面上膨胀
in curved space
or over a flat plane.
布洛克:当我们用这些宇宙尺
Bullock:
When we use these cosmic rulers
试图还原宇宙的形状时
to try to back out
the shape of the universe,
我们确信宇宙是平的
we're sure
to a few percent accuracy
精确度达到百分之几
that the universe is flat.
如果宇宙是平的
Narrator:
If the universe is flat,
我们可以开始进入宇宙
we could set off
traveling into the cosmos
并永远继续旅行
and continue traveling forever.
我们的宇宙可能没有边缘
There may be no edge
to our universe
因为平坦的宇宙可能是无限的
because a flat universe
can be an infinite universe.
现在我们认为宇宙
Now we're thinking of
the universe as something
确实是永无止境的
that really does
go on forever,
恒星和星系永远没有尽头
that the stars and galaxies
never have an end,
但真正无限的东西怎么可能存在呢？
and how can something
truly infinite really exist?
无限很奇怪，因为它是一个概念
Infinity is weird
because it's a concept of,
因为它是无限的
because it's endless.
这是什么意思？谁知道呢？我反正不知道
What does that mean? Who knows?
I don't know.
“无限”这个概念比其他任何东西都重要
Plait: Infinity is a concept
more than anything else.
我们的大脑并没有为此而进化
Our brains aren't
evolved for that.
我们在星球上进化
We evolved living in the plains.
我们是寻找食物的猿类
We were apes looking for food.
我们没有进化到能想明白宇宙
We weren't evolved to think
about the universe
和所有这些东西的地步
and all of this stuff.
奥卢西伊:我只是无法停止思考这些事情
Oluseyi: I just can't stop
contemplating this stuff.
无限的概念，无论这些数字有多巨大
The idea of infinity
and these large numbers
都是渺小的，甚至任何一切物质
and even the tininess
of everything.
它是疯狂的
It's nuts.
是的，想到无限让我有点头疼
Yeah, thinking about infinity
makes my head hurt a little bit.
一个无限的宇宙对于理解
Narrator: An infinite universe
has profound implications
我们在宇宙中的位置有着深远的意义
for understanding our place
in the cosmos.
它保证我们并不孤单
It guarantees we're not alone.
卡罗:但是如果宇宙是无限的
Carroll:
But if the universe is infinite,
那么可能会有无数个星系拥有有生命的行星
then there could be