了解宇宙是如何运行的（2010）

How the Universe Works S01E04

Part 4 April 18, 2021, 7:56 p.m.

Our sun will become a red giant.
试想像公元70亿年时的日出
Imagine a sunrise 7 billion A.D.
升起的, 不再是迷人的小巧黄圆盘
It's not just a little yellow disc
coming up all cheerful and nice.
看到的, 或是一个发胀的火红圆盘
What you would see is a huge,
swollen, bloated, red disc
慢慢从地平线爬上来
slowly reaching up over the horizon
太阳完全升起时
and when the sun is fully up in the sky,
向地球射出高温热力
it's blasting down heat on the Earth.
那就像把头伸进高温烛炉里
It would be like sticking your
head in an oven set to broil.
地球气温将高达几千度
Temperatures here on the Earth
will reach thousands of degrees.
海水将会沸腾, 群山将会熔掉
The oceans will boil,
the mountains will melt,
我们将面临世界末日
and we'll have the last
nice day on the planet Earth.
然后, 发胀的恒星将吞没地球
Then, the bloated star
will engulf the Earth.
但这个红巨星正步向自毁
But the giant red star
is self-destructing.
其核心越来越不稳定, 很危险
Its core becomes dangerously unstable.
当再没有氢气可作燃料
With no hydrogen left to fuel it,
恒星开始燃烧氦, 并使之聚合成碳
the star begins burning helium
and fusing it into carbon.
这时, 恒星从内到外地逐步自毁
The star is now destroying
itself from the inside out.
从核心迸发狂暴的能量到表面
blasting violent surges of energy
from its core to its surface.
这些能量波炸去恒星的外层
These energy waves blow
away the star's outer layers.
恒星慢慢崩解
Slowly, it disintegrates.
恒星灭亡
The star is dead.
只剩下一个极热的稠密核心
All that remains is an
intensely hot, dense core.
红巨星已变成白矮星
The red giant has become a white dwarf.
当恒星到达白矮星阶段
By the time a star reaches
the white dwarf stage,
核聚变过程已停顿
the fusion process has stopped.
引掣终于停下来
The engine has finally come to rest
太阳灭亡时
Our sun will end its
life as a white dwarf
将变成不比地球大的白矮星
no larger than the Earth,
但密度就较地球高100万倍
but a million times denser.
白矮星是奇妙物体, 密度极高
A white dwarf is a pretty amazing
object; it's incredibly dense.
若能把方糖般大的白矮星
if you could take a sugar
cit>e sized chunk of white dwarf
放在地球表面
and put it on the surface of the Earth,
它因密度极高, 会直接掉到地底
it would be so dense it would
fall right through the ground
在白矮星的核心
At the heart of a white dwarf,
天文学家认为藏有巨大的纯碳晶体
astronomers believe there's a
giant crystal of pure carbon,
一颗直径达几千英里的宇宙巨钻
a cosmic diamond
thousands of miles across.
想到太阳将沦为冰冷的黑炭渣
The idea that the sun will become this
sort of cool dark lump of cinder material
真让人伤感
is kind of sad.
但那将是…
But that really will be...
无数万亿卡计的钻石
sort of a trillion, trillion,
trillion-carat diamond.
想一想, 天上的钻石!
Think of that, a diamond in the sky.
但恒星能创造出较巨钻更珍贵之物
But stars can create something much
more precious than a massive diamond.
远较我们太阳大的恒星灭亡时
When stars much bigger than our sun die,
过程就更狂暴
their death is much more violent.
但垂死时, 它们创造出生命的构块
But in dying, they create
the building blocks of life.
巨星高速地生活, 明亮地燃烧
Giant stars live fast, burn bright,
轰烈地消亡
and die hard.
但它们的消亡带来生机
But from their destruction comes life.
巨型恒星的消亡创造出宇宙的构块
The death of massive stars creates
the building blocks of the universe,
生命的种子
the seeds of life itself.
距离地球不足600光年之处
Less than 600 light-years from Earth,
巨型的恒星参宿四接近死亡
the monster star,
Betelgeuse, is near death.
以太空年计算
Well, in space years.
它较我们太阳年轻
It's younger than our sun, millions,
只有几百万岁, 不是几十亿岁
not billions, of years old.
但其核心的核聚变就剧烈得多
But the fusion at its
core is far more intense.
参宿四跟太阳截然不同
Betelgeuse is a different
beast from the sun entirely.
它是个火红超巨星
It's a red super-giant.
原因是…
And the reason is because...
参宿四巨大得多
Betelgeuse is more massive.
它的质量是太阳的20倍
It has 20 times the mass of the sun,
意味其核心的活动
and that means what's
going on in its core
跟太阳的很不同
is very different than
what's going on in the sun's.
巨型恒星产生的压力和温度
Massive stars generate
pressures and temperatures
是宇宙里最厉害的
greater than anywhere
else in the universe.
参宿四的重力极大
The gravity of Betelgeuse is so powerful
能令愈来愈大的原子相撞
it can smash together
bigger and bigger atoms.
巨型恒星的核心就像一间工厂
The core of a massive
star is a kind of factory,
制♥造♥愈来愈重的元素
manufacturing heavier
and heavier elements,
亦因而导致恒星灭亡
which is what also leads
to the star's destruction.
一旦制♥造♥铁, 恒星就会完蛋
Once it makes the element
iron, the star is doomed.
在科幻小说的世界
In the world of science fiction,
有许多消灭恒星的机器…
there are many ideas about
what a star-killer machine
是何等模样的构思
might be like.
想不到的是, 元凶是平平无奇的铁
Strangely enough, it's as
run-of-the-mill as something as iron.
对于恒星, 铁是宇宙间最危险元素
To a star, iron is the most
dangerous element in the universe.
简直是毒物
It's poison.
铁吸收能量
Iron absorbs energy.
巨型恒星一旦创造铁
From the moment a
massive star creates iron,
就注定命不久矣
it has only seconds to live.
恒星设法把能量注入铁球
The star is trying to dump
energy into that iron ball
尝试使之熔合, 但不果
and trying to make
it fuse, but it can't.
铁球抢去恒星的能量
And so that ball is
robbing the star of energy,
而那些正是维持恒星生命的能量
and it's that energy that is
supporting the star itself.
因此, 核心一旦开始制♥造♥铁
So as soon as that iron starts
to be created in the core,
恒星就是判了自己死刑
the star has written
its own death sentence.
设法压破恒星的重力
The battle between gravity,
trying to crush the star,
和设法炸散恒星的核聚变之战争
and fusion, trying to blow it apart,
终于结束
is over.
有了铁, 核聚变就到了死胡同
With iron, fusion hits a dead end.
重力总能获胜
Gravity always wins.
铁核心崩塌
The iron core collapses.
恒星外层向核心猛烈撞击
The outer layers of the
star slam down into it
产生大规模爆♥炸♥
and a huge explosion is generated.
这是宇宙间最狂暴的事件, 超新星
its the single most violent event
in the universe, a supernova.
短短几秒间
In just a few seconds,
超新星产生的能量远较我们太阳多
supernovas create more
energy than our sun ever will.
开始制♥造♥铁之后的几秒内
Within a couple of seconds
after beginning to make iron,
恒星爆♥炸♥, 成为超新星
star explodes in a supernova.
下次拿着铁煎锅时要好好想一下了
So think about that when you're
holding one of your iron frying pans.
铁能在几秒间消灭一颗恒星
The iron killed a star
in just a few seconds.
是非常危险的东西
Dangerous stuff.
各地的望远镜在天际搜索超新星
Telescopes around the world
scan the skies for supernovas.