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永久黑暗前的最后一束亮光

The Last Light Before Eternal Darkness – White Dwarfs & Black Dwarfs

只要有能源 人类就能够在这个宇宙中存活
Humans can survive in this universe as long as we have an energy source.
不幸的是 宇宙会慢慢死去 这个过程长达几十亿年
Unfortunately, the universe will die. It will happen slowly, over many billions of years,
但它终会发生 在宇宙的时间尺度下 像太阳那样的恒星很快就会逝去
but it will happen. On a universal time scale, stars like our sun will be gone in no time.
庆幸的是 从人类的角度来看 几乎总会存在这样的地方:
Luckily, there are places that will exist practically forever from a human perspective:
恒星死去后的尸体……
the corpses of dead stars…
白矮星
white dwarfs.
在宇宙消亡之前 他们会是人类最后的家园
They could be humanity’s last home right before the death of the universe.
那么白矮星到底是什么?当它们最终死去时会发生什么?
What are these strange things and what happens when they finally die?
恒星的寿命差异很大
How long stars live varies drastically,
主要取决于它们的质量大小
depending on how massive they are.
例如 超大恒星燃烧得剧烈又迅速 仅存在了数百万年后就以超新星爆发的方式死去
For example, really massive stars burn hot and fast, dying violently in supernova a few million years after birth.
但是它们是例外
But they’re the exception.
97%的恒星最后会变成白矮星
97% of all stars will end their existence as white dwarfs.
通过两种方式:
There are two ways this can happen:
小号恒星即所谓的红矮星会燃烧几万亿年 直到它们最终安静地变成白矮星
Small stars – so-called red dwarfs – burn out over trillions of years until they eventually quietly turn into white dwarfs.
中号恒星 例如我们的太阳 转化的过程比较有趣
Medium-sized stars like our sun are more interesting.
把太阳想象成一个巨大的高压锅 在太阳核心地心引力会把氢原子融合成氦原子
Imagine the sun as a huge pressure cooker that fuses hydrogen into helium in its core through its gravity.
核聚变释放了极大的能量
The fusion of elements releases extreme amounts of energy,
这股释放出来的能量向外抵抗地心引力以稳定这颗恒星 使它保持着微妙的平衡
that pushes outwards and stabilizes the star, keeping it in a delicate balance.
当太阳衰老 核里的氢原子就会耗尽
When the sun is old, the hydrogen in the core is exhausted,
然后太阳就开始把氦原子融合成更重的元素
and the sun will begin to burn helium into heavier elements.
当它这么干的时候 它的外层就会脱离(核聚变的能量大于地心引力)
While doing so, it will shed its outer layers.
当这个过程完成的时候 一半以上的太阳外壳就会消散在太空
When this process is over , more than half of the sun’s mass will be lost into space as a spectacular
形成跨度为数百万公里的行星状星云 景象及其壮观
planetary nebula millions of kilometers across.
最后只剩下以前的核心
What remains will be its former core:
白矮星由此诞生 它是恒星的尸体
A white dwarf is born, a star corpse.
而它原来的直径是现在的100多倍
While its former self was about 100 times its diameter, now
现在它差不多和地球一样大 但是却有此前恒星一半的质量
it’s only about as big as Earth, but still with about half of its former mass.
这意味着它的密度极大 一匙的白矮星的质量就相当于一辆汽车的质量
This means it’s extremely dense, a teaspoon of white dwarf is about as massive as a car.
它表面的引力超过地球的100000倍
Its surface gravity is over 100,000 times higher than Earth’s.
如果你试图在它上面降落 你立即就会被压缩成一摊滚烫的血水
If you tried to land on it, you’d immediately be compressed into a steaming puddle.
白矮星的周围存在生命的可能性很小 但终究有这种可能性
Life around a white dwarf is very unlikely, but possible.
现存的白矮星大多数是死去的恒星 它们可能将任何曾与自己相伴的行星都强制毁灭了
Most of them that exist now were former stars that, well, died, which probably ruined any planets they once had.
但那不是全部 因为它们太小了
But that’s not all: since they are so small,
一个行星想要有液态水 绕白矮星旋转的距离得是地球与太阳距离的1/75
a planet would need to orbit them about 75 times closer than earth is to the sun to have liquid water.
这种接近有利有弊
This proximity has up and down sides:
首先 它会锁定这颗行星 使得行星上有规律的白天和黑夜
for one, it would tidally lock the planet giving it a permanent day and permanent night.
在那些昼与夜的交替处有可能产生生命
At the edges of these day and night zones life could be possible.
但是白矮星有一个非常稳定的能量输出
But white dwarfs have a very stable energy output,
所以与许多红矮星相比 住在它们周围实际上可能更安全
so they might actually be safer to live around than many red dwarfs.
在这一点上依然是推测
This is still speculation at this point,
但是如果我们能找到在白矮星周围定居下来的合适条件
but if we could find the white dwarf with the right conditions to settle around,
我们或许会有一个可居住长达几十亿年的家园
we could have a home for many billions of years.
但是白矮星为什么比其他类型的星星发光更久呢?
But why do they shine so much longer than other star types?
白矮星是相当热的 大约是太阳温度的四十倍
White dwarfs are very, very hot – up to 40 times hotter than our sun –
它们是宇宙中最热的物体
ranking among the hottest objects in the universe.
但是它们非常地不活跃
But they are not incredibly active.
它们里面的所有的热都被锁定得死死的
All the heat inside of them is trapped and has nowhere to go.
只有它表层的一些热能够逃进太空
Only on its outer layer can it escape into space.
但太空几乎是空的 所以热不能通过传递的方式而被转移
But space is mostly empty, so heat can’t be transferred by conduction.
能量逃走的唯一方式就是辐射
The only way energy can escape is by radiation.
而这种方式效率低下 白矮星要花万亿年的时间才能冷却下来
This is so inefficient that white dwarfs will take trillions of years to cool down,
这将使它们成为人类最后的避难所
which may make them humanity’s last refuge.
在一个逐渐死去的宇宙中 它们可能是光与能量的最后来源
They might be the last sources of light and energy in a dying universe.
根据一些估计 白矮星可能会闪耀长达1000亿 亿年
According to some estimates white dwarfs might shine as long as 100 billion billion years,
比宇宙存在的时间还长100亿倍 时间如此之长 那时普通的恒星都已熄灭
ten billion times longer than the universe has existed. So far into the future that no regular stars will shine any more,
星系也会消失 而且
galaxies will have evaporated, and
直到那时第一个白矮星才会变成第一个黑矮星
only then will the first white dwarf turn into the first black dwarf.
当此事发生 生命最后的希望就会破灭
When this happens the last hope for life will die off.
随着能量的耗尽黑矮星会变成不活跃的球体 也不再发光发热
Black dwarfs will be inactive spheres with no energy left to give,
如果你靠近的话 它依然大得足够杀死你
still massive enough to kill you if you get too close.
黑矮星的温度将会接近宇宙中可能的最低温度
So cold that they’ll be near the coldest possible temperature in the universe,
而且黑得几乎看不见
so dark that they are practically invisible.
宇宙将会进入它的最后阶段——热寂——只剩下一个不可辨识的宇宙
The universe will enter its last stage – heat death – which will leave the universe unrecognizable,
一个绝对黑暗冰冷的墓地
an absolutely dark and cold graveyard,
黑洞和黑矮星散落于万亿光年之中
with black holes and black dwarfs scattered over trillions of lightyears.
我们并不确定黑矮星最后将“走”向何方
We don’t know for sure what will happen with black dwarfs in the end.
如果作为原子基本组成成分的质子寿命有限的话
If the proton – one of the fundamental parts of atoms – has a limited lifespan,
黑矮星将在几十亿万年里缓慢地消失无踪
black dwarfs will slowly evaporate over many trillions of years.
如果质子不衰减的话
If the proton does not decay,
在一段时间内 黑矮星将可能通过量子隧道效应变成一个纯铁球
black dwarfs will probably turn into spheres of pure iron via quantum tunneling, over a timespan
它如此之巨大 称其为永恒是可以的
so obscenely gigantic that calling it forever is okay.
然后那些铁球无比孤独地穿越暗黑宇宙
These iron spheres will then travel completely alone through a dark universe.
不再有新的事情发生……
Nothing new will happen anymore…
永远
forever.
虽然这听起来有点悲观 离我们还太远 所以相对于目前的我们来说 它就相当于不会发生
While this may sound kind of dark, this is so far away that for our purposes today, it might as well not happen at all.
无数年后会发生什么也无所谓了
It doesn’t matter what happens in a billion trillion years.
现在 我们碰巧生活在一个极好的时代
Right now, we happen to exist at an excellent time,
还能赞叹一下这个充满无尽的恒星 光以及行星的宇宙
able to be in awe about a universe filled with endless stars and light and planets.
并且有足够的时间能够有朝一日去探索它们
And enough time to visit them one day.
我们的背景音乐可以在Spotify和iTunes下载 由我们在Epic Mountain的好朋友创作
Our music is finally available on Spotify and iTunes. it’s composed by our good friends at Epic Mountain,
两个开着工作室搞音乐的家伙
two guys with a studio who make music for a living.
你可以点击这里一看究竟 欢迎在脸谱网和Twitter上关注他们 如果你喜欢我们的视频
You can check them out here, and follow them on Facebook and Twitter. And if you like our videos,
欢迎在Patreon上支持我们
please consider supporting us on Patreon.
那将是对我们的莫大支持
It really would be extremely helpful.
如果你没(不)有(想)看(工)够(作)这里有更多关于太空的视频等着你哦
If you need an excuse to delay work a little bit longer, here’s a playlist with more space videos.

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视频概述

一个关于宇宙结局的剧本之一,热寂论的简要介绍

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收集自网络

翻译译者

Juan

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祐子祐

视频来源

https://www.youtube.com/watch?v=qsN1LglrX9s

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