了解宇宙是如何运行的（2010）

How the Universe Works S06E01

Part 6 Dec. 22, 2021, 7:22 p.m.

really sounds like physics.
奇点在自然界中是不存在的
Singularities
do not exist in nature,
当它们出现在数学中
and when they appear
in the mathematics,
那就是你做错了什么
that's a signal that you're
doing something wrong,
你肯定遗漏了什么
that you're incomplete.
这就像是终极诅咒
It's like
the ultimate curse word,
而大自然母亲不喜欢我们诅咒
and mother nature doesn't
like it when we curse.
为了完成数学计算并理解黑洞
To complete the math
and understand black holes,
宇宙学家们
cosmologists grapple
努力研究科学中最令人费解的概念之一……
with one of science's
most mind-bending concepts...
无穷
Infinity.
黑洞……它们被认为
Black holes...
They're thought to be
是宇宙的基本组成部分
a fundamental part
of the universe.
但科学家们不仅在努力解释
But scientists
are not only struggling
它们的工作原理
to explain how they work,
也在努力证明它们的存在
they're struggling
to prove they even exist.
所以，黑洞确实有一些问题
So, black holes have
some problems.
每次我们试着去想一些东西
Every time we try
to think of something,
用一些创造性的数学解决方案
some creative
mathematical solution
来完全描述黑洞的时候
to describe black holes fully,
它都失败了，我们就是无法取得任何进展
it breaks down, and we just
can't make any progress.
我们无法做出可靠的预测
We can't make
reliable predictions,
我们无法与观察结果进行比较
we can't compare
to observations.
解决方案是什么？
What is the solution?
我们真的不知道
We honestly don't know.
科学家们发现
Scientists are finding
广义相对论和量子力学
that general relativity
and quantum mechanics
在黑洞的边缘会出现混乱
go haywire at the edge
of a black hole.
但在黑洞内部，情况可能会更奇怪
But inside a black hole,
things could be even weirder.
当一颗巨大的濒死恒星坍塌时
When a giant dying star
collapses,
该恒星的质量就会坍缩，不断坍缩
the mass of the star falls in
and keeps falling in,
并最终挤压成一个无限小的点
crunching down into
an infinitely small point.
这个点被称为奇点
This is called the singularity.
奇点非常让人费解
A singularity is troubling
因为尽管它听起来很酷很科学
because although it sounds
cool and scientific,
但它实际上只是一个花哨的说法
it's really just
a fancy word of saying,
“哦，我们不知道这里发生了什么”
"oh, we have no clue
what happens here."
根据物理学的描述，当黑洞形成时
the way our physics describes
black holes when they form,
你取一个有限的质量
you're taking
a finite amount of mass
然后让它塌缩
and you're collapsing it down.
它的体积应该一直缩小到零
And its volume should shrink
all the way to zero,
但这意味着它有无限的密度和无限的引力
but that means it has infinite
density and infinite gravity,
这没有任何意义
and that doesn't make sense.
如果你做了一个预测，而答案是无穷大
If you make a prediction
and the answer is infinite,
那就说明你的预测有问题
it tells you there's something
wrong with your prediction,
因为我们今天在宇宙中从未看到过无穷大
Because we've never seen an
infinity in the universe today.
再说一遍，量子力学是问题的核心
Once again, quantum mechanics
is at the heart of the problem.
你有没有想过"量子力学"这个词
Have you ever thought about
the term "quantum mechanics"
有没有想过这些词是什么意思？
and thought about
what those words mean?
宇宙中的一切
Well, everything in the universe
都被分解成非常小的单元
is broken up into
tiny, little units.
确实存在一个基本的能量单位，时间单位
There really is a basic
unit of energy, a unit of time,
甚至空间单位，它们不能被进一步划分
even a unit of space that cannot
be divided any further.
再小的事物都是有限度的
There's a limit
to how small things can be.
宇宙中最小的空间单位
The smallest unit of space
in the universe
是所谓的普朗克长度
is what's known
as a Planck length.
如果你把一根头发
If you took a human hair
放大到可观测宇宙的宽度
and blew it up to the width
of the observable universe,
一普朗克长度大约是1/4000英寸
one Planck length would be
about 1/4000th of an inch.
如果最小的东西有一个普遍的极限
If there is a universal limit
on the smallest size,
那么无限小的东西就不存在了
then something infinitely small
can't exist.
如果无限不存在，那么奇点也不存在
Well, if infinity doesn't exist,
then singularities don't exist,
如果奇点不存在
and if singularities
don't exist,
那么爱因斯坦的广义相对论
then Einstein's theory
of general relativity
就不正确
is not correct.
最简单的方法就是
The simplest thing to do
is to say,
“我们来选一些新的方程
"well, let's choose
some new equations.
让我们以某种方式改变爱因斯坦的引力理论
Let's change Einstein's
theory of gravity somehow.
让我们发明一种我们称之为奇异的推测物理学”
Let's invent what we would call
exotic speculative physics."
这种推测性的物理学使科学家们
This speculative physics
has led scientists to invent
产生了“普朗克星”的概念
the idea of the Planck star.
如果你在太空中遇到过一个
If you passed one in space,
它看起来就像一个黑洞
it would look
just like a black hole.
但是普朗克星的核心并没有奇点
But a Planck star doesn't have
a singularity at its core.
也许所有东西不会坍缩到
Maybe things can't collapse down
小于普朗克长度
to less
than the Planck's length,
也许你会被这个普朗克大小的小块给困住
that maybe you get stuck with
this little Planck-size nugget
一切都是有限的
that stabilizes things,
keeps everything finite.
所以，一个奇点在黑洞的中心
So, where a singularity is
at the center of a black hole,
一个普朗克大小的小块在普朗克星的中心
a Planck-sized nugget is
at the center of a Planck star.
普朗克星很像一个黑洞
A Planck star is
just like a black hole,
只不过它遵循量子力学的规则
except it plays by the rules
of quantum mechanics.
问题是，普朗克星只是另一个奇异的理论
The problem is, Planck stars
are just another exotic theory.
之所以会有这么多奇异的黑洞替代品
The reason there are
so many exotic alternatives
是因为你可以写下无数种
to black holes is because
you can write down a gazillion
不同的假设、神秘的新物质
different postulated,
mysterious new kinds of matter
然后说，“假设存在这种奇怪的物质
and say, "suppose
this kind of weird stuff exists.
也许这可以解释这些数据”
Then maybe that could
explain the data."
问题是，没有证据证明
Problem is, there's no evidence
这类东西的存在
that any
of that kind of stuff exists.
科学家们越来越有创意，他们试图证明黑洞的存在。
他们想象出奇怪的物体，并使用奇异的方法变通。
但有一个关于黑洞的观点是最奇怪的：
如果我们生活在其中的一个呢？
如果我们真的生活在黑洞里,
那将是有史以来最令人兴奋的事情,
最疯狂的是，这有可能会发生，这可能是真的！
黑洞充满了理论上的黑洞
Black holes are
full of theoretical holes.
科学家说它们就在那里，但我们看不到