了解宇宙是如何运行的（2010）

How the Universe Works S08E04

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

but, no, the nuclear reactions
inside a star
补充了失去的能量
replenish the energy
that's lost,
并保持恒星的温度和内部的压力
and keep the star hot
and pressurized inside,
这样就可以维持压力-重力之间的平衡
so that the pressure-gravity
balance can be maintained.
这种平衡让类太阳的恒星
Narrator:
This balance
keeps sun-like stars alive
存活了100亿年
for up to 10 billion years,
直到恒星的油箱耗尽
until the star's gas tank
runs dry.
普莱特:它会耗尽燃料的
Plait: It's gonna
run out of fuel.
当这种情况发生时，它就会死亡
And when that happens,
it's going to die.
但那会是什么样子呢？
But what is that
gonna look like?
这是怎么发生的？
How is this
gonna happen?
1亿年前
Narrator:
One hundred million years ago,
j1228 系统开始变得糟糕
things in the j1228 system
started to get ugly.
首先，恒星变大了——真的非常大
First, the star grew large --
really large.
斯特劳恩:一旦中心开始聚变较重的元素
Straughn: Once the center starts
fusing heavier elements,
外部就会膨胀
the outside will swell
最终形成一颗红巨星
into what will eventually be
a red giant star.
J1228 变成了一颗红巨星
Narrator: J1228 transformed
into a red giant.
它的外层炸开了
Its outer layers blew off,
向外延伸了4000万英里（约6♥4♥40万公里）
extending out
over 40 million miles.
当像我们的太阳这样的恒星死亡时，这并不是一件平静的事情
When stars like our sun die,
it's not a quiet affair.
非常暴♥力♥、危险和混乱
It's very violent,
and ugly, and messy.
它们变成了红巨星
They turn into
red giants,
它们把自己从内到外翻转
and they turn themselves
inside out,
然后呕吐到整个恒星系
and vomit
all over the solar system.
当 j1228 膨胀成一颗红巨星时
Narrator: When j1228 swelled
into a red giant,
附近的行星被困在了死亡地带
nearby planets
were stuck in a kill zone.
这颗垂死的恒星吞没了它们
The dying star engulfed them,
or fried them
或者用超过1200华氏度的温度把它们烤焦
with temperatures of over
1,200 degrees fahrenheit.
大气层消失了
Atmospheres disappeared.
海洋沸腾了
Oceans boiled away,
但有一个星球在 j1228 的死亡阵痛中幸存了下来
but one planet survived
j1228's death throes.
在这个例子中，有一颗行星在某种意义上
Here's a case where a planet
survived, in some sense,
在它自己的恒星死亡后，侥幸存活了下来
the death of its own star,
and it's still hanging around,
仍然坚持在那里，等待着新的希望
still hanging on,
hoping for something new.
红巨星膨胀的外层
Narrator: The red giant's
expanding outer layers
从恒星的核心分离出来
separated from
the star's core.
由于没有活跃的核聚变，内核坍缩成一颗白矮星
With no active fusion, the core
collapsed into a white dwarf.
这颗白矮星的强大引力
The white dwarf's
dense gravity
在这颗存活下来的行星上起了作用
then went to work
on the one surviving planet.
弗林彭科:这颗围绕正常恒星运行的行星
Flippenko:
The planet that might've been
orbiting the normal star
可能会逐渐向白矮星旋转
can gradually spiral in
toward the white dwarf,
最终，白矮星对行星近侧的引力
and then, eventually, the
gravity of the white dwarf pulls
会超过对远侧的引力
on the near side of the planet
more than on the far side,
从而将其撕裂
and that tears it apart.
普莱特:我们在这里看到的是一颗死亡恒星
Plait: What we're seeing here
is a dead star
在吞噬自己的恒星系
dining on
its own solar system.
这就是未来的太阳
That's what is in the future
for the sun.
J1228 饱餐了它的岩石世界的残骸
Narrator: J1228 feasted on the
remains of its rocky worlds,
留下了一个碎片盘和行星的核心
leaving behind a disk of debris
and the planetary core.
这是对地球未来的一瞥
It's a glimpse
of earth's future.
白矮星周围发生的事
What happened here
around this white dwarf
也会发生在地球上
is gonna happen
to earth.
它的大气层，地壳和地幔
It's gonna be stripped
of its atmosphere,
将被剥离
its crust,
and its mantle,
剩下的只有地核
and the only thing that
will remain will be the core.
被一颗垂死的恒星炸成碎片——
Narrator: Fried and ripped apart
by a dying star --
这可不是个好下场
not a good way to go.
幸运的是，对于地球上的生命来说
Fortunately,
for life on earth,
我们自己的太阳还没到消亡的时候
our own sun
isn't dying just yet.
普莱特:太阳现在是个“中年人”
Plait:
The sun is middle-aged.
它已经45亿年了
It's 4.5 billion years old,
而且还会再持续50到60亿年
and it's going to go on for
another 5 or 6 billion years.
萨特:在我们的太阳将整个太阳系
Sutter: We've got
a little bit of time
都吞噬之前，我们还有一点时间
before our sun pukes
all over the solar system.
我们的母星现在可能是安全的
Narrator: Our home planet
may be safe for now,
但是像 j1228 这样的系统告诉我们
but systems like j1228
show us
类太阳的恒星注定会死亡
that sun-like stars
are destined to die,
所有围绕它们运行的生命都会死亡
killing off any life
orbiting them.
但类日恒星并不是宇宙中
But sun-like stars
aren't the only stars
唯一会死亡的恒星
dying across the cosmos.
外面还有其他恒星，他们都难逃一死
There are others out there,
and they're all doomed.
宇宙中存在各种各样的恒星
There's a wonderful
rainbow of stars
它们形状各异
out there,
of all different shapes,
大小各异，颜色各异
all different sizes,
and all different colors.
斯特劳恩:我们说的是恒星，你知道的
Straughn: We're talking down to,
you know,
从只有太阳质量几分之一的
fractions of the mass
of the sun,
到高达太阳质量的数百倍的都有
up to hundreds of times
the mass of the sun.
说到恒星末日的时候，尺寸很重要
Narrator:
When it comes to the star
apocalypse, size matters.
恒星越大、越亮，死亡的速度就越快
The bigger and brighter
the star, the faster it dies.
♪
我们的宇宙是一片充满死亡和毁灭的广阔天地
narrator:
Our universe is a vast expanse
of death and destruction.
所有的恒星都注定要死亡，但不是一下子全部死亡
All of the stars are destined
to die, but not all at once.
不会有一个特定的时间点
There's not going to be
one particular point
所有的星光同时熄灭
where all the lights turn off
at the same time.
更像是停电
It's more like
a power outage,
不同的电网在不同的时间停电
where different grids go off
at different times, until,
直到最后一个灯泡的熄灭
like, there's the one last
light bulb that'll just go off.
这是因为恒星有不同的大小尺寸
Narrator: This is because stars
come in different sizes.
一颗恒星死亡的方式