了解宇宙是如何运行的（2010）

How the Universe Works S08E04

Part 6 Jan. 30, 2022, 2:58 p.m.

that life could survive here.
你可以认为这些白矮星
You can kind of think
of these white dwarfs
可能会为宇宙制♥造♥更多的能量
as maybe making a little
more energy for the universe,
但即使是这些能量最终也会耗尽
but even that's going
to eventually run out.
整个天体变成了巨大的晶体
The whole thing becomes
a gigantic crystal and, again,
然后开始冷却，逐渐消失
it's just going to
start cooling and fading away.
僵尸最后变成了一个黑暗的灰烬
Narrator: The zombie fizzles out
into a dark cinder,
几乎不发出任何光
giving off almost
no light at all,
但还有另一个怪物潜伏在宇宙中
but there's another monster
lurking in the cosmos.
泰勒:当一颗比太阳质量大得多的恒星死亡时
Thaller: When a star that's much
more massive than the sun dies,
它会发生剧烈的爆♥炸♥
it explodes violently,
在爆♥炸♥过程中，它的核心会坍缩
and during that explosion,
the core collapses
变成一个密度大得难以置信的小天体
and becomes an incredibly dense,
small object,
是宇宙中最奇妙的真正的怪物之一
one of the most wonderful
real monsters in the universe.
脉冲星……
This is a pulsar...
Psr b0329+54
Psr b0329+54,
距离我们3000光年
3,000 light-years away from us.
这颗脉冲星的质量与太阳相当
The pulsar has the mass
of the sun,
但直径只有12英里（约19.3公里）
but is just 12 miles across.
它的快速旋转从两极产生辐射束
Its rapid spin generates beams
of radiation from its poles,
能使僵尸复活
bringing the zombie to life.
现在，我们发现了一个围绕这颗僵尸恒星运行的外星世界
Now, we've discovered an alien
world orbiting this zombie star.
明加雷利:2017年，人们在脉冲星周围
Mingarelli:
In 2017, a new planet
发现了一颗新行星
was discovered around a pulsar.
它们的质量大约是地球的两倍
They're about twice
the mass of the earth,
这真的很不可思议
and that's really incredible.
这颗脉冲星听起来很有趣
Narrator: The pulsar planet
sounds intriguing,
但是生命的前景并不乐观
but the prospects
for life aren't good.
环绕脉冲星运行的环境对于生命来说是非常恶劣
Orbiting a pulsar would be
a brutal environment for life.
明加雷利:不太可能有生命存在
Mingarelli: It's highly unlikely
that there's life
因为这个系统产生的辐射非常大
because the radiation from this
system would be overwhelming
很可能会吹走大气层
and likely blow away
the atmosphere.
关于在宇宙中维持生命
Narrator: As for sustaining life
in the universe,
看来这些选择都不是你所说的安全赌注
none of these options
is what you'd call a safe bet.
♪
这些只是暂时缓解不可避免的后果
these are momentary reprieves
from the inevitable.
不管你怎么做，最终
No matter what you do,
eventually,
你会用完所有这些东西
you're going to run out
of these gimmes.
你的免监禁卡就要用完了
You're going to run out of the
get-of-jail-free cards.
不可避免地，一切都会冷却和消失
Inevitably, everything is going
to cool and fade away.
♪
这可能是恒星，甚至生命的
narrator: This might be
game over for stars
游戏结束时间
and even for life.
但在宇宙中仍有一线希望
But there is still a glimmer
of hope hidden in the cosmos,
一颗并没有消亡的恒星
a star that isn't dying.
它似乎有永恒的生命
It appears blessed
with eternal life,
它的颜色是红色的
and its color is red.
红矮星——我们确实被它们包围着
Red dwarfs -- we are literally
surrounded by them,
但它们大部分是我们看不见的
but they are largely
invisible to us.
♪
星星的光芒照亮了
narrator: Illuminating
every corner of our night sky
夜空的每一个角落……
is the light of stars...
但我们肉眼所见并不能说明全部情况
But what we see with a naked eye
doesn't tell the whole story.
♪
泰勒:你看到的恒星主要是像太阳一样的恒星
thaller:
The stars that you're seeing
are mainly stars like the sun
或者比太阳更大、更热的恒星
or even more massive
and even hotter than the sun.
他们是光明的，你可以从远处看到它们
They're bright. You can see them
from a distance,
但令人惊讶的是，迄今为止
but amazingly, the most
common form of star,
最常见的恒星形式，是红矮星
by far, are
the red dwarf stars.
它们现在就在天空中
They're up there right now
in the sky,
但它们太小太暗了，我们看不见
but they're just too small
and too faint to see.
红矮星比太阳小十倍
Narrator: Red dwarfs are up to
10 times smaller than the sun,
燃烧得也不那么明亮
and they burn less brightly.
现在，隐藏在夜空中的银河系中
Right now,
hidden in the night sky,
超过四分之三的恒星都是红矮星……
over three-quarters of the stars
in our galaxy are red dwarfs...
虽然较大的恒星正在消亡
And while the larger stars
are dying out,
但我们从未见过红矮星消亡
we've never seen
a red dwarf die,
这使它们成为生命在恒星末日中生存的
making them
the best bet for life
最佳选择
to survive the star apocalypse.
当质量最大的恒星最终消失
When the most massive stars
eventually go out
没有被取代时，剩下的将是
and are not replaced,
what will be left
非常非常暗淡的恒星比如红矮星
are much, much dimmer stars
like red dwarf stars.
我们已经看到了宇宙中恒星的死亡
Narrator: We've seen star death
across the universe,
为什么红矮星没有呢？
so why not red dwarfs?
事实证明
Turns out their size
它们的大小使它们比更大的恒星具有关键的优势
gives them a crucial advantage
over larger stars.
泰勒:恒星质量越大，燃烧的温度就越高
Thaller: The more massive a star
is, the hotter it burns.
红矮星的燃烧温度较低
A red dwarf star burns
at a lower temperature.
所以它不会像中等质量恒星
So it doesn't burn through
it's fuel
那样快速燃烧燃料
quite as quickly
as a mid-mass star does.
它们就像宇宙中的经济型车
These are like the economy
cars of the universe.
他们只是在啜饮他们的核燃料
They're just sipping
on their nuclear fuel,
然后在慢慢地滑行
and they can coast along.
不仅如此，尽管它们更小
Narrator: Not only that,
despite being smaller,
但它们还有更多的燃料
they have access to more fuel.
我们中等大小的太阳被分成三层——
Our mid-size sun
is split into three layers --
一个核心、一个辐射区
a core, a radiation zone,
和一个对流层
and a convective layer.
辐射区阻止了顶层的氢
The radiation zone prevents
hydrogen in the top layer
成为核心燃烧的材料
from ever becoming available
for the core to burn.
所以太阳只能获得
So the sun can only access
所有氢燃料的10%
about 10 percent
of its total hydrogen fuel.
一旦太阳核心的氢耗尽
Once the hydrogen
in our sun's core runs out,
它的日子就屈指可数了
its days are numbered.
在某种程度上，这些中等大小的恒星
In some ways,
these mid-sized stars
最终会饿死自己
end up starving themselves.
小一点的红矮星就不一样了
Narrator: The smaller red dwarfs
are different.
它们可以获得所有它们想要的氢