黑洞全解密——从诞生到消亡：英语精读讲义

Black holes are one of the strangest things in existence. 語法

黑洞是宇宙中最不可思议的存在之一。

They don't seem to make any sense at all. 短語搭配

它们似乎完全违背了常理。

Where do they come from?

它们从何而来？

And what happens if you fall into one?

如果你掉进黑洞会发生什么？

Stars are incredibly massive collections of mostly hydrogen atoms

恒星是质量极大的集合体，主要由氢原子组成，

that collapse from enormous gas clouds under their own gravity.

它们是由巨大的气体云在自身重力作用下坍缩而成的。

In their core,

在它们的核心，

nuclear fusion crushes hydrogen atoms into helium, 短語搭配

核聚变将氢原子挤压成氦，

releasing a tremendous amount of energy. 講解

释放出极其巨大的能量。

This energy,

这种能量，

in the form of radiation, 短語搭配

以辐射的形式，

pushes against gravity,

与重力相互对抗，

maintaining a delicate balance between the two forces.

维持着这两种力量之间微妙的平衡。

As long as there is fusion in the core, 語法

只要核心内还有核聚变，

a star remains stable enough.

恒星就能保持足够的稳定。

But for stars with way more mass than our own sun, 語法

但对于质量远大于太阳的恒星来说，

the heat and pressure at the core allow them to fuse heavier elements until they reach iron. 語法

核心的高温和高压让它们能够聚变更重的元素，直到形成铁。

Unlike all the elements that went before,

与之前产生的所有元素不同，

the fusion process that creates iron doesn't generate any energy.

产生铁的聚变过程不会释放任何能量。

Iron builds up at the center of the star until it reaches a critical amount, 短語動詞

铁在恒星中心不断积累，直到达到一个临界值，

and the balance between radiation and gravity is suddenly broken.

辐射和重力之间的平衡被突然打破。

The core collapses.

核心坍缩了。

Within a fraction of a second, 短語搭配

在不到一秒钟的时间里，

the star implodes,

恒星向内塌陷，

moving at about a quarter of the speed of light,

以大约四分之一光速的速度，

feeding even more mass into the core.

将更多的质量填入核心。

It's at this very moment that all the heavier elements in the universe are created 語法

正是在这一刻，宇宙中所有更重的元素诞生了，

as the star dies in a supernova explosion.

伴随着恒星在超新星爆发中走向死亡。

This produces either a neutron star or, 語法

这会产生一颗中子星，或者，

if the star is massive enough,

如果恒星质量足够大，

the entire mass of the core collapses into a black hole.

整个核心的质量就会坍缩成一个黑洞。

If you looked at a black hole, 語法

如果你观察一个黑洞，

what you'd really be seeing is the event horizon.

你真正看到的其实是事件视界。

Anything that crosses the event horizon needs to be traveling faster than the speed of light to escape.

任何穿过事件视界的物质都需要以超光速移动才能逃脱。

In other words, 表達脈絡

换句话说，

it's impossible.

这是不可能的。

So we just see a black sphere reflecting nothing.

所以我们只看到一个什么也不反射的黑色球体。

But if the event horizon is the black part,

但如果事件视界是黑色的部分，

what is the hole part of the black hole?

那么黑洞的“洞”又是什么呢？

The singularity.

奇点。

We're not sure what it is exactly.

我们不完全确定它到底是什么。

A singularity may be infinitely dense, 語法

奇点可能有着无限大的密度，

meaning all its mass is concentrated into a single point in space with no surface or volume,

意味着它的所有质量都集中在空间中的一个点上，没有表面也没有体积，

or something completely different.

或者是某种完全不同的东西。

Right now,

目前，

we just don't know.

我们还不知道。

It's like a dividing by zero error. 表達脈絡

这就像是一个除以零的错误。

By the way, 表達脈絡

顺便说一句，

black holes do not suck things up like a vacuum cleaner. 短語動詞

黑洞并不会像吸尘器那样吸东西。

If we were to swap the sun for an equally massive black hole, 語法

如果我们把太阳换成一个同等质量的黑洞，

nothing much would change for Earth,

对地球来说并没有太大改变，

except that we would freeze to death, of course.

除了我们会冻死之外。

What would happen to you if you fell into a black hole?

如果你掉进黑洞会发生什么？

The experience of time is different around black holes.

在黑洞周围，时间的体验是不同的。

From the outside,

从外面看，

you seem to slow down as you approach the event horizon, 語法

当你接近事件视界时，你的动作似乎变慢了，

so time passes slower for you.

也就是说你的时间变慢了。

At some point,

在某个时刻，

you would appear to freeze in time,

你似乎在时间里定格了，

slowly turn red,

慢慢变红，

and disappear.

然后消失。

While from your perspective,

但从你的视角来看，

you can watch the rest of the universe in fast forward, 習語

你可以像快进一样看到宇宙其余部分的变化，

kind of like seeing into the future. 語氣意圖

就像看到了未来一样。

Right now, we don't know what happens next,

目前，我们不知道接下来会发生什么，

but we think it could be one of two things.

但我们认为可能是两种情况之一。

One,

第一种，

you die a quick death.

你死得很快。

A black hole curves space so much that once you cross the event horizon, 語法

黑洞将空间极度弯曲，一旦你越过事件视界，

there is only one possible direction.

就只剩下一个可能的方向了。

You can take this literally. 用詞

你可以从字面上去理解。

Inside the event horizon,

在事件视界内部，

you can only go in one direction.

你只能朝一个方向走。

It's like being in a really tight alley that closes behind you after each step. 表達脈絡

就像走在一条极其狭窄的巷子里，每走一步身后就会封死。

The mass of a black hole is so concentrated,

黑洞的质量如此集中，

at some point,

以至于在某个时刻，

even tiny distances of a few centimeters

即使是几厘米的微小距离，

would mean that gravity acts with millions of times more force on different parts of your body.

也意味着你身体不同部位受到的引力差异会达到数百万倍。

Your cells get torn apart

你的细胞会被撕裂，

as your body stretches more and more 語法

随着你的身体被拉得越来越长，

until you're a hot stream of plasma one atom wide.

直到你变成一束只有一个原子宽的高温等离子流。

Two,

第二种，

you die a very quick death.

你死得非常非常快。

Very soon after you cross the event horizon,

在你穿过事件视界后不久，

you would hit a firewall and be terminated in an instant.

你就会撞上一道火墙，在瞬间终结。

Neither of these options are particularly pleasant. 語法

这两个选择都不怎么令人愉快。

How soon you would die depends on the mass of the black hole.

你多久会死取决于黑洞的质量。

A smaller black hole would kill you before you even entered its event horizon,

较小的黑洞会在你进入事件视界之前就把你杀死了，

while you probably could travel inside a supermassive black hole for quite a while. 表達脈絡

而你在超大质量黑洞里面可能还能旅行相当长一段时间。

As a rule of thumb, 習語

经验法则是，

the further away from the singularity you are, 語法

距离奇点越远，

the longer you live.

你活得越久。

Black holes come in different sizes. 短語搭配

黑洞有不同的大小。

There are stellar mass black holes

有恒星级黑洞，

with a few times the mass of the sun and the diameter of an asteroid.

质量是太阳的几倍，直径却只有小行星那么大。

And then there are the supermassive black holes,

还有超大质量黑洞，

which are found at the heart of every galaxy 習語

它们存在于每个星系的中心，

and have been feeding for billions of years. 習語

已经吞噬了数十亿年。

Currently,

目前，

the largest supermassive black hole known is S50014+81,

已知最大的超大质量黑洞是S50014+81，

40 billion times the mass of our sun. 語法

其质量是我们太阳的400亿倍。

It is 236.7 billion kilometers in diameter, 短語搭配

它的直径为2367亿公里，

which is 47 times the distance from the sun to Pluto.

是太阳到冥王星距离的47倍。

As powerful as black holes are, 語法

尽管黑洞如此强大，

they will eventually evaporate through a process called Hawking radiation. 語法

它们最终也会通过一种称为霍金辐射的过程蒸发掉。

To understand how this works, 表達脈絡

要理解这是如何运作的，

we have to look at empty space.

我们必须看看真空。

Empty space is not really empty, 語法

所谓的真空其实并不空，

but filled with virtual particles popping into existence and annihilating each other again. 短語動詞

而是充满了凭空出现又相互湮灭的虚粒子。

When this happens right on the edge of a black hole,

当这发生在黑洞边缘时，

one of the virtual particles will be drawn into the black hole 語法

其中一个虚粒子会被吸入黑洞，

and the other will escape and become a real particle.

另一个则会逃逸并变成真实粒子。

So the black hole is losing energy.

这样，黑洞就在失去能量。

This happens incredibly slowly at first

这个过程一开始极度缓慢，

and gets faster as the black hole becomes smaller.

随着黑洞变得越来越小，速度会加快。

When it arrives at the mass of a large asteroid,

当它变成一颗大行星的质量时，

it's radiating at room temperature. 短語搭配

它会在室温下辐射。

When it has the mass of a mountain,

当它变成一座山的质量时，

it radiates with about the heat of our sun,

它的辐射热量大约和我们的太阳差不多，

and in the last second of its life,

而在它生命的最后一秒，

the black hole radiates away with the energy of billions of nuclear bombs

黑洞会以数十亿颗核弹的能量辐射殆尽，

in a huge explosion.

并在巨大的爆炸中结束。

But this process is incredibly slow.

但这个过程慢得惊人。

The biggest black holes we know might take up to a googol years to evaporate. 語法

我们知道的最大黑洞可能需要长达一古戈尔年才能蒸发完。

This is so long that when the last black hole radiates away, 語法

这个时间太长了，当最后一个黑洞辐射消亡时，

nobody will be around to witness it.

已经没有任何人能见证它了。

The universe will have become uninhabitable 語法

宇宙也将会变得不再适合居住，

long before then.

早在那个时候之前。

This is not the end of our story. 表達脈絡

这还不是我们故事的结局。

There are loads more interesting ideas about black holes. 用詞

关于黑洞还有很多有趣的想法。

We'll explore them in part two.

我们将在第二部分中探索它们。

A big thanks to Fraser Cain for help with this video.

非常感谢Fraser Cain对本视频的帮助。

By the way,

顺便说一句，

we've made some Kurzgesagt wallpapers in 4K for different screen sizes.

我们制作了一些适用于不同屏幕尺寸的4K Kurzgesagt壁纸。

You can get them on our Patreon page,

你可以在我们的Patreon页面上获取，

which also helps us to make more videos.

这也有助于我们制作更多的视频。

Like this December,

比如今年十二月，

the first month ever with three videos.

我们史无前例地在一个月内发布了三个视频。