永恆黑暗前的最後一道光 —— 白矮星與黑矮星：英語精讀講義

Humans can survive in this universe as long as we have an energy source. 文法

只要有能量源，人類就能在這個宇宙中生存下去。

Unfortunately, the universe will die.

不幸的是，宇宙將會走向死亡。

It will happen slowly over many billions of years,

這是一個漫長的過程，需要數十億年，

but it will happen.

但它終究會發生。

On a universal time scale,

在宇宙的時間尺度上，

stars like our sun will be gone in no time. 慣用語

像太陽這樣的恆星很快就會消亡。

Luckily, there are places that will exist practically forever from a human perspective. 片語搭配

幸運的是，從人類的角度來看，有些地方幾乎可以永遠存在。

The corpses of dead stars,

那就是死亡恆星的屍體——

white dwarfs.

白矮星。

They could be humanity's last home right before the death of the universe.

它們可能成為宇宙死亡前人類最後的家園。

What are these strange things?

這些奇怪的東西究竟是什麼？

And what happens when they finally die?

當它們最終死亡時又會發生什麼？

How long stars live varies drastically,

恆星的壽命差異極大，

depending on how massive they are. 文法

取決於它們的質量。

For example,

例如，

really massive stars burn hot and fast,

質量極大的恆星燃燒得又熱又快，

dying violently in supernovae a few million years after birth.

在誕生幾百萬年後就會在超新星爆發中猛烈地死去。

But they're the exception.

但它們只是例外。

97% of all stars will end their existence as white dwarfs.

宇宙中97%的恆星最終都會變成白矮星。

There are two ways this can happen.

這通常有兩種方式。

Small stars,

質量較小的恆星，

so called red dwarfs,

即所謂的紅矮星，

burn out over trillions of years 片語動詞

會在數萬億年的時間裡慢慢燃燒，

until they eventually quietly turn into white dwarfs. 片語動詞

直到最終靜靜地變成白矮星。

Medium-sized stars like our sun are more interesting.

像太陽這樣的中等質量恆星則更有趣。

Imagine the sun as a huge pressure cooker 表達脈絡

把太陽想像成一個巨大的高壓鍋，

that fuses hydrogen into helium in its core

在其核心透過引力

through its gravity.

將氫聚變成氦。

The fusion of elements releases extreme amounts of energy

元素的聚變釋放出極大的能量，

that pushes outwards and stabilizes the star,

這些能量向外推擠，穩定了恆星，

keeping it in a delicate balance. 片語搭配

使其保持著微妙的平衡。

When the sun is old,

當太陽老去時，

the hydrogen in the core is exhausted,

核心的氫被耗盡，

and the sun will begin to burn helium into heavier elements.

太陽便開始將氦聚變成更重的元素。

While doing so, 表達脈絡

在這個過程中，

it will shed its outer layers. 用詞

它會褪去它的外層。

When this process is over,

當這個過程結束時，

more than half of the sun's mass will be lost into space

太陽一半以上的質量都將散落到太空中，

as a spectacular planetary nebula

形成一個壯觀的行星狀星雲，

millions of kilometers across. 文法

跨度達數百萬公里。

What remains will be its former core. 文法

留下的將是它曾經的核心。

A white dwarf is born,

一顆白矮星誕生了，

a star corpse.

一具恆星的屍體。

While its former self was about 100 times its diameter, 文法

它曾經的直徑是現在的100倍左右，

now it's only about as big as Earth,

現在只有地球那麼大，

but still with about half of its former mass.

但依然保留著過去一半的質量。

This means it's extremely dense.

這意味著它的密度極高。

A teaspoon of white dwarf is about as massive as a car. 文法

一茶匙白矮星物質的質量大約相當於一輛汽車。

Its surface gravity is over 100,000 times higher than Earth's. 文法

其表面引力是地球的10萬倍以上。

If you tried to land on it, 文法

如果你試圖在上面登陸，

you'd immediately be compressed into a steaming puddle.

你會立刻被壓成一灘冒著熱氣的肉泥。

Life around a white dwarf is very unlikely,

在白矮星周圍存在生命的希望十分渺茫，

but possible.

但也並非不可能。

Most of them that exist now were former stars that,

現存的大多數白矮星都是曾經死去的恆星，

well, died, 語氣意圖

嗯，死去了，

which probably ruined any planets they once had.

這可能毀掉了它們曾經擁有的所有行星。

But that's not all. 表達脈絡

但還不止這些。

Since they are so small,

因為它們太小了，

a planet would need to orbit them about 75 times closer 文法

行星需要在一個比地球離太陽近大約75倍的軌道上繞行，

than Earth is to the sun to have liquid water.

才能擁有液態水。

This proximity has ups and downs. 慣用語

這種近距離有利也有弊。

For one, 表達脈絡

首先，

it would tidally lock the planet,

它會潮汐鎖定行星，

giving it a permanent day and permanent night.

讓它有一面永遠是白天，一面永遠是黑夜。

At the edges of these day and night zones,

在晝夜交界處，

life could be possible.

生命可能是存在的。

But white dwarfs have a very stable energy output,

此外白矮星的能量輸出非常穩定，

so they might actually be safer to live around 文法

所以在它們周圍生活實際上可能更安全，

than many red dwarfs.

甚至比許多紅矮星還要安全。

This is still speculation at this point, 片語搭配

雖然目前這還只是推測，

but if we could find a white dwarf

但如果我們能找到一顆白矮星，

with the right conditions to settle around,

並且條件適合定居，

we could have a home for many billions of years.

我們就能擁有一個可以居住數十億年的家園。

But why do they shine so much longer than other star types?

可是為什麼它們發光的時間比其他類型的恆星長那麼多？

White dwarfs are very,

白矮星非常、

very hot,

非常熱，

up to 40 times hotter than our sun, 文法

溫度最高可達我們太陽的40倍，

ranking among the hottest objects in the universe.

是宇宙中最熱的天體之一。

But they are not incredibly active.

但它們並不極其活躍。

All the heat inside of them is trapped

它們內部所有的熱量都被困住了，

and has nowhere to go. 片語搭配

無處可去。

Only on its outer layer can it escape into space. 文法

只有在外層，熱量才能散發到太空中。

But space is mostly empty,

但是太空大部分是真空的，

so heat can't be transferred by conduction.

所以熱量不能透過傳導來傳遞。

The only way energy can escape is by radiation. 文法

能量逃逸的唯一方式是輻射。

This is so inefficient 文法

這種方式效率極低，

that white dwarfs will take trillions of years to cool down, 片語動詞

以至於白矮星需要數萬億年的時間才能冷卻下來，

which may make them humanity's last refuge. 慣用語

這可能使它們成為人類最後的避難所。

They might be the last sources of light and energy

它們可能是這個垂死宇宙中

in a dying universe.

最後的光和能量來源。

According to some estimates, 片語搭配

根據一些估算，

white dwarfs might shine as long as 100 billion billion years, 用詞

白矮星可能會發光長達1000億億年，

10 billion times longer than the universe has existed.

比宇宙目前存在的歷史長100億倍。

So far into the future

在那麼遙遠的未來，

that no regular stars will shine anymore.

任何常規的恆星都不會再發光了。

Galaxies will have evaporated. 文法

星系也將消散。

And only then will the first white dwarf 文法

直到那時，第一顆白矮星才會

turn into the first black dwarf.

變成第一顆黑矮星。

When this happens,

當這件事發生時，

the last hope for life will die off. 片語動詞

生命最後的希望也將破滅。

Black dwarfs will be inactive spheres with no energy left to give.

黑矮星將變成沒有能量可以釋放的不活躍球體。

Still massive enough to kill you if you get too close.

儘管它們仍然具有極大的質量，靠得太近仍會喪命。

So cold that they'll be near the coldest possible temperature 文法

它們極度寒冷，接近於宇宙中的

in the universe.

絕對最低溫度。

So dark that they are practically invisible.

它們極其黑暗，幾乎不可見。

The universe will enter its last stage,

宇宙將進入它的最後階段：

heat death, 文化背景

熱寂，

which will leave the universe unrecognizable.

這將使宇宙變得面目全非。

An absolutely dark and cold graveyard

一個絕對黑暗和寒冷的墳墓，

with black holes and black dwarfs

裡面充滿了黑洞和黑矮星，

scattered over trillions of light years.

散佈在數萬億光年的空間裡。

We don't know for sure 片語搭配

我們無法確定

what will happen with black dwarfs in the end.

黑矮星最終會發生什麼。

If the proton,

如果質子——

one of the fundamental parts of atoms,

這個原子的基本組成部分之一——

has a limited lifespan,

有有限的壽命，

black dwarfs will slowly evaporate over many trillions of years.

那麼黑矮星將在數萬億年的時間裡慢慢蒸發。

If the proton does not decay,

如果質子不衰變，

black dwarfs will probably turn into spheres of pure ion

黑矮星可能會透過量子穿隧效應

via quantum tunneling over a time span

變成純離子球，這需要經過一段

so obscenely gigantic that calling it forever is okay. 文法

漫長得離譜的時間，用「永恆」來形容也毫不誇張。

These ion spheres will then travel completely alone

這些離子球將在黑暗的宇宙中

through a dark universe.

孤獨地穿行。

Nothing new will happen anymore.

再也不會有任何新鮮事發生。

Forever.

永遠。

While this may sound kind of dark,

雖然這聽起來有些陰鬱，

this is so far away that for our purposes today,

但這離我們太遙遠了，就目前的狀況而言，

it might as well not happen at all. 片語搭配

它完全等同於不會發生。

It doesn't matter what happens in a billion trillion years. 文法

萬億億年後發生什麼並不重要。

Right now,

就在當下，

we happen to exist at an excellent time, 片語搭配

我們碰巧存在於一個絕佳的時代，

able to be in awe about a universe filled with endless stars

能夠敬畏這個充滿無盡星辰、

and light and planets

光芒和行星的宇宙，

and enough time to visit them one day.

並且我們有足夠的時間在未來去造訪它們。

Our music is finally available on Spotify and iTunes.

我們的音樂終於在 Spotify 和 iTunes 上架了。

It's composed by our good friends at Epic Mountain,

它由我們的好朋友 Epic Mountain 創作，

two guys with a studio who make music for a living. 片語搭配

兩個有工作室、靠做音樂謀生的小夥子。

You can check them out here 片語動詞

你可以在這裡查看他們的作品，

and follow them on Facebook and Twitter.

並在 Facebook 和 Twitter 上追蹤他們。

And if you like our videos,

如果你喜歡我們的影片，

please consider supporting us on Patreon.

請考慮在 Patreon 上支持我們。

It really would be extremely helpful.

這真的會對我們有極大的幫助。

If you need an excuse to delay work a little bit longer,

如果你需要一個藉口再拖延一會兒工作，

here's a playlist with more space videos.

這裡有一個包含更多太空影片的播放清單。