了解宇宙是如何运行的（2010）

How the Universe Works S08E04

Part 3 Jan. 30, 2022, 2:58 p.m.

The way a star dies
has everything to do with
与它诞生之初的质量息息相关
the amount of mass
it started life with.
这一属性贯穿着它的整个生命周期
It carries that all the way
through its lifetime.
太阳是一个中等大小的恒星
Narrator: The sun is
a medium-sized star
稳定地存在了数十亿年
living a stable existence
for billions of years.
巨恒星是完全不同的
Giant stars
are different.
他们的生命挥霍地快，死得也早
They live fast,
and die young.
像太阳这样的恒星，是一颗中等大小的恒星
A star like the sun,
which is a medium-sized star,
它的寿命大约是100亿年
it lives about
10 billion years.
那些巨大的恒星
The really massive stars,
可能只有1000万年
they live maybe
10 million years.
大质量恒星的质量可能是太阳的
Narrator:
Massive stars can be tens
or even hundreds of times
数十倍甚至数百倍
more massive than the sun.
当涉及到寿命时，这是一个问题
When it comes to life span,
that's a problem.
弗林彭科:从核聚变的角度来说，大质量恒星有更多的燃料可以燃烧
Flippenko:
A massive star has more fuel
to burn, in a nuclear sense.
所以，你可能会天真地认为它持续的时间更长
So, you might naively think
that it lasts longer,
但事实恰恰相反
but it's the
exact opposite.
大质量恒星只能在其核心获取氢燃料
Narrator:
Massive stars can only access
hydrogen fuel in their core.
其余的被困在外层
The rest is trapped
in the outer layers,
无法用作燃料
and can't be used as fuel.
普莱特:如果内核中有氢，那就没问题了
Plait: If there's hydrogen
in the core, you're good.
如果在核心外有氢，它就不能被使用
If there's hydrogen outside
of the core, it can't be used.
如果它不在你的油箱里，它对你没有任何好处
If it's not in your fuel tank,
it's not doing you any good.
大质量恒星也比小恒星有更多的引力
Narrator:
Massive stars also have
more gravity than smaller stars,
所以它们必须更快地燃烧氢燃料
so they have to burn
their hydrogen fuel faster
来防止恒星的坍缩
to prevent the star
from collapsing.
他们过分消耗精力
They burn their candle
on both ends.
由于它们惊人的质量
Because of
their incredible mass,
它们在核心的聚变反应
their fusion reactions
in the core
以惊人的速度发生着
happen at an
incredible rate.
斯特里克:巨星的消耗速度很快，而且很狂暴
Stricker: Giant stars are
kind of fast and furious.
它们很明亮
They are bright.
它们过着挥霍无度的生活，然后很快就会死去
They live their life,
and they die very quickly.
当一颗巨恒星的燃料耗尽时
Narrator: When a giant star's
fuel runs out,
它的内核会在巨大的引力作用下
the core collapses
catastrophically
发生灾难性地崩塌
under the overwhelming
force of gravity.
然后，爆♥炸♥，超新星爆发了
And then, boom,
supernova.
一颗巨恒星的死亡
Narrator:
The death of a giant star
引发了宇宙中最大的爆♥炸♥之一
triggers one of the biggest
bangs in the universe.
爆♥炸♥会立即使附近的行星汽化
The blast would instantly
vaporize nearby planets.
但这些恒星的死亡对生命也是至关重要的
But these star deaths
are also critical for life.
当大质量恒星死亡时，它们会释放出
When massive stars die,
they release heavy elements
它们在一生中所制♥造♥的重元素
they've been making through
the course of their lives.
有时，他们甚至会制♥造♥新的元素
And sometimes,
they even make new ones.
正是这些较重的元素对生命至关重要
And it's these heavier elements
that are essential for life.
我们的存在要归功
We owe our existence
to stars
于数十亿年前形成的恒星
that formed
billions of years ago.
2018年5月，我们发现了古老恒星
Narrator:
In may of 2018, we spotted
evidence of ancient stars
创造生命物质的证据
creating the stuff of life.
我们接收到一个来自遥远星系
We picked up
an infrared light signal
macs1♥1♥4♥9-jd1 的红外光信♥号♥♥
from a distant galaxy
named macs1♥1♥4♥9-jd1.
信♥号♥♥是电离氧
The signal was
ionized oxygen.
它已经运行了133亿年
It's been traveling
for 13.3 billion years,
所以氧气是在宇宙还很年轻的时候就形成了
so the oxygen formed when
the universe was very young --
也就是大爆♥炸♥后5亿年
just 500 million years
after the big bang.
这些氧形成于大质量恒星的中心
This oxygen formed
in the hearts of massive stars.
霍普金斯:氧气的存在告诉我们
Hopkins: The presence
of oxygen tells us
在早期的宇宙中，需要有大质量的恒星
that there needed to be massive
stars in the early universe
才能将氢和氦合成
in order to synthesize
hydrogen and helium
更重的元素，比如氧气
into heavier elements,
like oxygen,
然后爆♥炸♥，将氧气喷射到
and then explode
to eject that oxygen
星际和星系间的介质中
back into the interstellar
and intergalactic medium.
恒星核心的高压会产生氧气……
Narrator:
Extreme pressure in the cores
of the stars produces oxygen...
……还有其他元素，比如碳和氮
...And other elements,
like carbon and nitrogen.
超新星爆♥炸♥将这些元素传播到整个宇宙
Supernova blasts spread these
elements across the universe,
在新元素的帮助下创造了新一代的恒星
helping to create
new generations of stars,
最重要的是，还创造了我们
and, most importantly, us.
如果在所有的科学中
If there is one single fact
that you should care about
有一个你应该关心的事实——这也是我最喜欢的事实——
in all of science --
and this is my favorite fact --
那就是你和我都是恒星死亡的结果
is that you and I
are a consequence of star death.
布洛克:在有生命之前，你需要有
Bullock: Before you can have
life, you need to have
构成生命的元素
the kind of elements
out of which life forms.
你需要碳你需要的氮
You need carbon.
You need nitrogen.
你需要氧气
You need oxygen.
从生物学的角度来说
You need the elements
that are the backbone
我们就是由这些元素所构成的
to the biology
that makes us possible.
这些元素从何而来？
Where did those elements
come from?
它们来自恒星
Well, they came from stars.
它们来自于宇宙早期形成的恒星
They came from stars that formed
in the early universe,
甚至在太阳出现之前
before even
the sun existed.
大质量恒星的巨大体积
Narrator:
The huge size of massive stars
很快就宣告了它们的死亡
quickly signs
their death warrants.
它们爆♥炸♥的末日为创造新的恒星提供了帮助，甚至生命
Their explosive ends help create
new stars, and even life.
你之所以存在，就是因为有恒星
The fact that you exist at all
is because of stars.
但是，在探索宇宙中的星系时
Narrator: But, probing galaxies
across the universe,
我们发现了其他的东西
we've discovered
something else.
恒星末日不仅仅是毁灭恒星
The star apocalypse
isn't just killing stars.
它还阻止了它们的诞生
It's stopping them