黑洞全解密——從誕生到消亡：英語精讀講義

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

黑洞是宇宙中最不可思議的存在之一。

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

它們似乎完全違背了常理。

Where do they come from?

它們從何而來？

And what happens if you fall into one?

如果你掉進黑洞會發生什麼？

Stars are incredibly massive collections of mostly hydrogen atoms

恆星是質量極大的集合體，主要由氫原子組成，

that collapse from enormous gas clouds under their own gravity.

它們是由巨大的氣體雲在自身重力作用下塌陷而成的。

In their core,

在它們的核心，

nuclear fusion crushes hydrogen atoms into helium, 片語搭配

核融合將氫原子擠壓成氦，

releasing a tremendous amount of energy. 講解

釋放出極其巨大的能量。

This energy,

這種能量，

in the form of radiation, 片語搭配

以輻射的形式，

pushes against gravity,

與重力相互對抗，

maintaining a delicate balance between the two forces.

維持著這兩種力量之間微妙的平衡。

As long as there is fusion in the core, 文法

只要核心內還有核融合，

a star remains stable enough.

恆星就能保持足夠的穩定。

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

但對於質量遠大於太陽的恆星來說，

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

核心的高溫和高壓讓它們能夠融合成更重的元素，直到形成鐵。

Unlike all the elements that went before,

與之前產生的所有元素不同，

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

產生鐵的融合過程不會釋放任何能量。

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

鐵在恆星中心不斷累積，直到達到一個臨界值，

and the balance between radiation and gravity is suddenly broken.

輻射和重力之間的平衡被突然打破。

The core collapses.

核心塌陷了。

Within a fraction of a second, 片語搭配

在不到一秒鐘的時間裡，

the star implodes,

恆星向內塌陷，

moving at about a quarter of the speed of light,

以大約四分之一光速的速度，

feeding even more mass into the core.

將更多的質量填入核心。

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

正是在這一刻，宇宙中所有更重的元素誕生了，

as the star dies in a supernova explosion.

伴隨著恆星在超新星爆發中走向死亡。

This produces either a neutron star or, 文法

這會產生一顆中子星，或者，

if the star is massive enough,

如果恆星質量足夠大，

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

整個核心的質量就會塌陷成一個黑洞。

If you looked at a black hole, 文法

如果你觀察一個黑洞，

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

你真正看到的其實是事件視界。

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

任何穿過事件視界的物質都需要以超光速移動才能逃脫。

In other words, 表達脈絡

換句話說，

it's impossible.

這是不可能的。

So we just see a black sphere reflecting nothing.

所以我們只看到一個什麼也不反射的黑色球體。

But if the event horizon is the black part,

但如果事件視界是黑色的部分，

what is the hole part of the black hole?

那麼黑洞的「洞」又是什麼呢？

The singularity.

奇異點。

We're not sure what it is exactly.

我們不完全確定它到底是什麼。

A singularity may be infinitely dense, 文法

奇異點可能有著無限大的密度，

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

意味著它的所有質量都集中在空間中的一個點上，沒有表面也沒有體積，

or something completely different.

或者是某種完全不同的東西。

Right now,

目前，

we just don't know.

我們還不知道。

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

這就像是一個除以零的錯誤。

By the way, 表達脈絡

順帶一提，

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

黑洞並不會像吸塵器那樣吸東西。

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

如果我們把太陽換成一個同等質量的黑洞，

nothing much would change for Earth,

對地球來說並沒有太大改變，

except that we would freeze to death, of course.

除了我們會凍死之外。

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

如果你掉進黑洞會發生什麼？

The experience of time is different around black holes.

在黑洞周圍，時間的體驗是不同的。

From the outside,

從外面看，

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

當你接近事件視界時，你的動作似乎變慢了，

so time passes slower for you.

也就是說你的時間變慢了。

At some point,

在某個時刻，

you would appear to freeze in time,

你似乎在時間裡定格了，

slowly turn red,

慢慢變紅，

and disappear.

然後消失。

While from your perspective,

但從你的視角來看，

you can watch the rest of the universe in fast forward, 慣用語

你可以像快轉一樣看到宇宙其餘部分的變化，

kind of like seeing into the future. 語氣意圖

就像看到了未來一樣。

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

目前，我們不知道接下來會發生什麼，

but we think it could be one of two things.

但我們認為可能是兩種情況之一。

One,

第一種，

you die a quick death.

你死得很快。

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

黑洞將空間極度彎曲，一旦你越過事件視界，

there is only one possible direction.

就只剩下一個可能的方向了。

You can take this literally. 用詞

你可以從字面上來理解。

Inside the event horizon,

在事件視界內部，

you can only go in one direction.

你只能朝一個方向走。

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

就像走在一條極其狹窄的巷子裡，每走一步身後就會封死。

The mass of a black hole is so concentrated,

黑洞的質量如此集中，

at some point,

以至於在某個時刻，

even tiny distances of a few centimeters

即使是幾公分的微小距離，

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

也意味著你身體不同部位受到的重力差異會達到數百萬倍。

Your cells get torn apart

你的細胞會被撕裂，

as your body stretches more and more 文法

隨著你的身體被拉得越來越長，

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

直到你變成一束只有一個原子寬的高溫電漿流。

Two,

第二種，

you die a very quick death.

你死得非常非常快。

Very soon after you cross the event horizon,

在你穿過事件視界後不久，

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

你就會撞上一道火牆，在瞬間終結。

Neither of these options are particularly pleasant. 文法

這兩個選擇都不怎麼令人愉快。

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

你多久會死取決於黑洞的質量。

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

較小的黑洞會在你進入事件視界之前就把你殺死了，

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

而你在超大質量黑洞裡面可能還能旅行相當長一段時間。

As a rule of thumb, 慣用語

經驗法則告訴我們，

the further away from the singularity you are, 文法

距離奇異點越遠，

the longer you live.

你活得越久。

Black holes come in different sizes. 片語搭配

黑洞有不同的大小。

There are stellar mass black holes

有恆星級黑洞，

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

質量是太陽的幾倍，直徑卻只有小行星那麼大。

And then there are the supermassive black holes,

還有超大質量黑洞，

which are found at the heart of every galaxy 慣用語

它們存在於每個星系的中心，

and have been feeding for billions of years. 慣用語

已經吞噬了數十億年。

Currently,

目前，

the largest supermassive black hole known is S50014+81,

已知最大的超大質量黑洞是S50014+81，

40 billion times the mass of our sun. 文法

其質量是我們太陽的400億倍。

It is 236.7 billion kilometers in diameter, 片語搭配

它的直徑為2367億公里，

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

是太陽到冥王星距離的47倍。

As powerful as black holes are, 文法

儘管黑洞如此強大，

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

它們最終也會透過一種稱為霍金輻射的過程蒸發掉。

To understand how this works, 表達脈絡

要理解這是如何運作的，

we have to look at empty space.

我們必須看看真空。

Empty space is not really empty, 文法

所謂的真空其實並不空，

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

而是充滿了憑空出現又相互湮滅的虛粒子。

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

當這發生在黑洞邊緣時，

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

其中一個虛粒子會被吸入黑洞，

and the other will escape and become a real particle.

另一個則會逃逸並變成真實粒子。

So the black hole is losing energy.

這樣，黑洞就在失去能量。

This happens incredibly slowly at first

這個過程一開始極度緩慢，

and gets faster as the black hole becomes smaller.

隨著黑洞變得越來越小，速度會加快。

When it arrives at the mass of a large asteroid,

當它變成一顆大行星的質量時，

it's radiating at room temperature. 片語搭配

它會在室溫下輻射。

When it has the mass of a mountain,

當它變成一座山的質量時，

it radiates with about the heat of our sun,

它的輻射熱量大約和我們的太陽差不多，

and in the last second of its life,

而在它生命的最後一秒，

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

黑洞會以數十億顆核彈的能量輻射殆盡，

in a huge explosion.

並在巨大的爆炸中結束。

But this process is incredibly slow.

但這個過程慢得驚人。

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

我們所知最大的黑洞可能需要長達一古高爾年才能蒸發完。

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

這個時間太長了，當最後一個黑洞輻射消亡時，

nobody will be around to witness it.

已經沒有任何人能見證它了。

The universe will have become uninhabitable 文法

宇宙也將會變得不再適合居住，

long before then.

早在那個時候之前。

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

這還不是我們故事的結局。

There are loads more interesting ideas about black holes. 用詞

關於黑洞還有很多有趣的想法。

We'll explore them in part two.

我們將在第二部分中探索它們。

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

非常感謝Fraser Cain對本影片的幫助。

By the way,

順帶一提，

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

我們製作了一些適用於不同螢幕尺寸的4K Kurzgesagt桌布。

You can get them on our Patreon page,

你可以在我們的Patreon頁面上獲取，

which also helps us to make more videos.

這也有助於我們製作更多的影片。

Like this December,

比如今年十二月，

the first month ever with three videos.

我們史無前例地在一個月內發布了三支影片。