They don’t seem to make any sense at all; where do they come from?

他們完全沒道理，他們從何而來？

And what happens if you fall into one?

而當你落入黑洞又會發生什麼事？

Stars are incredibly massive collections of mostly hydrogen atoms that collapse from enormous gas clouds under their own gravity.

恆星大部分是由多到不可思議的氫原子聚集，巨量的氣體雲被自己的引力所吸引而塌陷。

In their core, nuclear fusion crushes hydrogen atoms into helium, releasing a tremendous amount of energy.

在它的核心內，核融合將氫原子組合成氦原子，釋放出極大量的能量。

This energy, in the form of radiation, pushes against gravity, maintaining a delicate balance between the two forces.

這股能量以輻射作為存在，反抗著引力向外推，將兩股力間維持在一個微妙的平衡。

As long as there is fusion in the core, a star remains stable enough.

只要核心持續核融合，恆星就能維持足夠的穩定度。

But for stars with way more mass than our own Sun, the heat and pressure at the core allow them to fuse heavier elements, until they reach iron.

但對於那些比我們太陽質量大上許多的恆星，核心內的熱能和壓力可以使它們合成更重的元素， 直到它們合成鐵原子。

Unlike all the elements that went before, the fusion process that creates iron doesn’t generate any energy.

不像先前提到的原子，產生出鐵原子的過程並不會產生任何的能量。

Iron builds up at the center of the star until it reaches a critical amount, and the balance between radiation and gravity is suddenly broken.

鐵在恆星中央組成直到一定程度的量後，輻射能與重力之間的平衡就瓦解了。

The core collapses.

核心開始崩塌。

Within a fraction of a second, the star implodes, moving at about a quarter of the speed of light, feeding even more mass into the core.

在若干分之一秒內，恆星產生自爆，以 1/4 光速移動， 持續餵給核心更多的質量。

It’s at this very moment that all the heavier elements in the universe are created, as the star dies in a supernova explosion.

宇宙中所有重元素都是在這特別的時刻被創造的，而後恆星死於這場超新星爆炸。

This produces either a neutron star or, if the star is massive enough, the entire mass of the core collapses into a black hole.

最後可能會產生中子星，或者當恆星質量夠大時，整個核心崩塌的質量都落入黑洞。

If you looked at a black hole, what you’d really be seeing is the event horizon.

如果你看著黑洞，你真正能看到的是它的事件視界。

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

任何東西越過了事件視界，移動速度必須要比光速快才能逃脫。

In other words, it’s impossible.

換句話說，這不可能。

So we just see a black sphere, reflecting nothing.

所以我們只看到了一個不會反射任何東西的黑暗球面。

But if the event horizon is the “black” part, what is the “hole” part of the black hole?

但如果事件視界是 "黑" 的部份，那什麼是黑洞中 "洞" 的部份呢？

The singularity.

奇點。

We’re not sure what it is exactly.

我們不確定它究竟是怎樣。

A singularity may be infinitely dense, meaning all its mass is concentrated into a single point in space with no surface or volume.

一個奇點可能有著無限大的密度，意味著所有物質集中-在一個沒有表面也沒有體積的點上。

Or something completely different.

或者是個完全不同的狀況。

Right now, we just don’t know.

目前，我們還不知道。

It’s like a dividing by zero error.

這就像是個分母為零的分數。

By the way, black holes do not suck things up like a vacuum cleaner.

順代一提，黑洞不像是吸塵器把東西吸走。

If we were to swap the Sun for an equally massive black hole, nothing much would change for Earth, except that we would freeze to death, of course.

如果我們把太陽換成個同等質量的黑洞，對地球並沒有什麼影響， 當然，我們預計會被冷死。

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

當你落入黑洞時會發生什麼事？

The experience of time is different around black holes.

在黑洞附近經過的時間和平常不太相同。

From the outside, you seem to slow down as you approach the event horizon, so time passes slower for you.

從外面看來，當你接近事件視界時會變慢，所以你流經過的時間較緩慢。

At some point, you would appear to freeze in time, slowly turn red, and disappear.

到達某點時，你看起來就如時間被動結了一般，顏色慢慢偏紅，然後消失。

While from your perspective, you can watch the rest of the universe in fast-forward, kind of like seeing into the future.

當以你為觀測點時，你可以看到整個宇宙快速前進，類似於看到未來。

Right now, we don’t know what happens next, but we think it could be one of two things.

現在，我們不清楚接下來會發生什麼事，但預測會發生以下兩種結果，

One: you die a quick death.

一：你死得很痛快。

A black hole curves space so much that once you cross the event horizon there is only one possible direction.

黑洞將時空大幅度地扭曲，一旦你跨過了事件視界，就只剩下唯一一個前進的方向。

You can take this literally: inside the event horizon, you can only go in one direction.

從字面上看：在事件視界內，你只有一個方向可以走。

It’s like being in a really tight alley that closes behind you after each step.

這就像是個小巷子，當你每走一步後面的路就消失。

The mass of a black hole is so concentrated, at some point, even tiny distances of a few centimeters would mean that gravity acts with millions of times more force on different parts of your body.

黑洞的物質非常集中，從某個角度來看，即使是幾公分的微小差距， 也可能使你身體的不同部份承受著數百萬倍不同的重力。

Your cells get torn apart as your body stretches more and more, until you’re a hot stream of plasma one atom wide.

你的細胞在身體被拉扯時一塊一塊被撕開，直到你變成一個原子寬的流動電漿。

Two: you die a very quick death.

二：你死得很快。

Very soon after you cross the event horizon, you would hit a fire wall and be terminated in an instant.

在你越過了事件視界後，你很快地會撞上一道火牆，並在一瞬間被消滅。

Neither of these options are particularly pleasant.

上述兩種情況都不怎麼舒服。

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

你會死多快取決於黑洞的質量。

A smaller black hole would kill you before you even entered its event horizon, while you probably could travel inside a supermassive black hole for quite a while.

小一點的黑洞可能會在你尚未到達事件視界就殺掉你，超大質量的黑洞可能會讓你在事件視界內逛個一陣子。

As a rule of thumb, the further away from the singularity you are, the longer you live.

從經驗來看，你離奇點越遠，你救活得越久。

Black holes come in different sizes.

黑洞有著不同的尺寸。

There are stellar-mass black holes with a few times the mass of the Sun and the diameter of an asteroid.

有的質量只比太陽大幾倍，直徑和小行星一樣。

And then there are the supermassive black holes, which are found at the heart of every galaxy and have been feeding for billions of years.

有的則是超級巨大的黑洞，每個所知的銀河系中央都有一個， 而且已經被餵食了數十億年之久。

Currently, the largest supermassive black hole known is S5 0014+81, forty billion times the mass of our Sun.

目前，已知的最大黑洞是 S5 0014+81，是太陽質量的 4 百億倍。

It is 236.7 billion kilometers in diameter, which is 47 times the distance from the Sun to Pluto.

直徑長達 2367 百億公里，是太陽到冥王星距離的 47 倍。

As powerful as black holes are, they will eventually evaporate through a process called Hawking radiation.

就算黑洞再怎麼強大，它們最終仍會經由一個叫做 "霍金輻射" 的過程而蒸發。

To understand how this works, we have to look at empty space.

要了解它是怎麼運作的，我們必須說明一下宇宙的真空。

Empty space is not really empty, but filled with virtual particles popping into existence and annihilating each other again.

真空中並不是真的空無一物，而是充滿了虛擬粒子，瞬間產生並瞬間消滅對方。

When this happens right on the edge of a black hole, one of the virtual particles will be drawn into the black hole, and the other will escape and become a real particle.

當這狀況發生在黑洞邊緣時，其中一部分的虛擬粒子會落入黑洞， 另一部份將會逃離並變成真的粒子。

So the black hole is losing energy.

所以黑洞正在失去能量。

This happens incredibly slowly at first, and gets faster as the black hole becomes smaller.

這過程起初發生得很慢，當黑洞變得越小時則越來越快。

When it arrives at the mass of a large asteroid, it’s radiating at room temperature.

當它質量簡少到如大型小行星一般時，它會發射出有著一般室溫的熱輻射。

When it has the mass of a mountain, it radiates at about the heat of our Sun.

當它縮小到一個山脈的大小時，它會散發出同太陽一樣的溫度的熱輻射。

And in the last second of its life, the black hole radiates away with the energy of billions of nuclear bombs in a huge explosion.

而在它生命的最後一秒，黑洞變成輻射蒸發掉了，其中會伴隨著數十億倍核彈爆炸的能量，

But this process is incredibly slow.

但這過程非常地緩慢。

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

目前已知最大的黑洞要花上 10^100（googol）年才會蒸發。

Nobody will be around to witness it.

到時候將沒有人可以親眼見證。

The universe will have become uninhabitable long before then.

遠在發生之前宇宙就會變得不適合居住。

This is not the end of our story; there are loads more interesting ideas about black holes.

這還不是故事的結尾，還有更多有關黑洞好玩的事情。

We’ll explore them in part 2.

我們將會在 part 2 探討它們。

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

感謝 Fraser Cain 大大的強力贊助。

By the way, we’ve made some Kurzgesagt wallpapers in 4K for different screen sizes;

我跟你說喔，我們做了一些 4K 的 Kurzgesagt 桌布喔！它可以用在不同尺寸的螢幕上呢！

you can get them on our Patreon page, which also helps us to make more videos.

想要就去我們 Patreon 頁面拿啦，這會讓我們更想製作更多的影片

Like this December, the first month ever with three videos!

像這個 12 月，是我們第一次在一個月內製作 3 部影片呢！

Subtitles by the Amara.org community

Julian Lai 的爛翻譯