了解宇宙是如何运行的（2010）

How the Universe Works S09E07

Part 7 March 16, 2022, 8:55 a.m.

You're trying to boil them.
水的对流使细胞被加热
You've got convective cells
of water that are heated.
把火调到顶部
Bring the heat up to the top.
把土豆弄热
Get the potatoes hot.
然后这些水珠冷却下来，变得密度更大
And then those blobs of water
cool down, become denser,
然后再次沉降到底部
and settle down to
the bottom again
在那里它们再次被加热
where they're heated once more.
当聚变将氢变成氦
As fusion
turns hydrogen
然后变成碳时，对流
to helium and then to
carbon, convection mixes
将碳混合，从而燃烧
the carbon so it burns up.
保罗·萨特:“对流细胞”在恒星内部工作
PAUL SUTTER: Convection
cells work inside
就像巨大的升降机，从中心区域
of a star like
massive elevators that
带走热气体，把它带到表面
take hot gas from
the central regions,
让它冷却，然后把物质
bring it up to the surface,
allow it to cool, and then
拉回核心
pull that material back down.
它们在恒星内部不断地来回转动
They're constantly churning
back and forth inside of a star.
但是像 N6946-BH1 这样比太阳质量
But stars more
massive than roughly 20 times
大20倍的恒星就
the mass of the
sun, like N6946-BH1,
不会这样燃烧碳
don't burn carbon this way.
聚变反应产生的更重的原子
Instead of mixing,
the heavier atoms
开始堆积，而不是混合
created by the fusion reactions
just start to pile up.
这意味着在核心表面
That means there's
a layer of very
有一层非常致密的物质
dense material building up on
just the surface of the core.
所有的东西都快要坍塌了
All of the stuff is
just ready to collapse.
有可能的情况是，如果你周围有足够的质量
It's possible that, if
you have enough mass sitting
坍缩的力量非常强大
around, the collapse
is so powerful
以至于在超新星爆发前
that it actually collapses
into a black hole
坍缩成一个黑洞
before any supernova goes off.
因此，这是一颗失败的超新星
That, then, is a
failed supernova.
它是一颗直接
It's a star that
pretty much directly
坍缩形成黑洞的恒星
collapses to form a black hole.
如果我们预期中的许多大质量恒星不会
If many of the massive
stars we expect to go supernova
变成超新星，那就有个问题
won't, that's a problem.
我们曾经认为我们已经破解了超新星的基本原理
We used to think we had the
basics of supernovas cracked.
任何时候，只要有一颗恒星的质量
Any time you have a star
more massive than eight times
超过太阳质量的8倍，它就注定会
the mass of the
sun, it was destined
爆♥炸♥成超新星
to explode as a supernova.
然后出现了一颗恒星，把一切都搞砸了
And then along comes a star
that screws everything up.
更糟糕的是，我们发现
To make things
worse, we found no clear
恒星发生爆♥炸♥和没有发生爆♥炸♥之间
distinction between
stars that go out with
没有明显的区别
a bang and those that don't.
多达30%的大质量恒星可能会在不爆♥炸♥的情况下死亡
As many as 30% of massive stars
could die without exploding.
我们寻找下一个超新星杀手的任务
Our search for the
next killer supernova
越来越难了
is getting even harder.
菲尔·普莱特:恒星会在我们意想不到的时候爆♥炸♥
PHIL PLAIT: Stars blow up
when we don't expect them to.
它们不会在我们期望的时候爆♥炸♥
They don't blow up
when we expect them to.
它们可能有几颗恒星♥相♥互环绕
They can have several
stars orbiting each other,
而爆♥炸♥的那颗不一定是你认为
and the one that blows up
isn't necessarily the one
会爆♥炸♥的那颗
you think it will.
所以现在我们还不能确定主要嫌疑人
So right now we
can't identify a prime suspect,
但追捕仍在继续
but the hunt continues.
保罗·萨特:据我们所知
PAUL SUTTER: As far
as we know, there
目前没有危及生命的恒星
are no life-threatening
stars out there,
但我们还没有做一个完整的调查
but we haven't done
a complete survey.
所以请继续资助天文学，这样我们才能继续寻找
So please keep funding astronomy
so we can keep looking.
超新星能毁灭
Supernovas destroy.
但他们也能创造吗？
But can they also create?
是超新星引发了人类的崛起
Did a supernova spark
humanity's rise to dominate
主宰了我们的世界和太阳系吗？
our world and our solar system?
超新星是壮观的，毁灭性的，也是可怕的
Supernovas are spectacular,
devastating, and frightening.
但没有它们，我们就不存在
But without them,
we wouldn't exist.
你血液中的铁和骨骼中的钙
The iron in your blood and
the calcium in your bones
实际上是在一颗数十亿年前爆♥炸♥成超新星的恒星
was literally forged inside of
a star that exploded billions
中锻造出来的
of years ago as
a supernova.
我认为这是我们在天文学中所学到的
And I think this is one of the
most beautiful and the most
最美丽和最深刻的东西之一
profound things that we've
learned in astronomy,
我们与宇宙是发自内心的联♥系♥
that we're literally viscerally
connected to the cosmos
宇宙与我们是联♥系♥在一起的
and the cosmos is
connected to us.
每一次呼吸，我们都在
With every breath,
we are inhaling
吸入来自超新星爆♥炸♥的氧气
oxygen that was created
in a supernova explosion.
[爆♥炸♥]
[booming]
这几乎就是宇宙生命的循环
This is almost literally
a cosmic cycle of life.
[爆♥炸♥]
[booming]
超新星甚至可能通过
And the
supernova may even
引发闪电而导致
be responsible for the
dawning of our intelligence
人类智慧的诞生
by causing lightning.
这听起来很不可思议
It might sound
rather incredible,
但超新星可能会直接影响
but a supernova might actually
influence, directly, weather
地球上的天气
right here on the Earth.
来自超新星的宇宙射线会在
The cosmic rays from a
supernova will create charges
低层大气中产生电荷
in the lower atmosphere.
这种能量会使分子分♥裂♥
That energy will
break apart molecules,
激发原子和分子，并使它们电离
excite atoms and molecules,
and it will ionize them.
电离的大气意味着
And an ionized
atmosphere means that now
它现在可以导电
it can conduct electricity.
所以它可能增加了整个星球的闪电
So it probably increased
lightning across the planet.
可能260万年前导致大灭绝的
It's possible the
same gamma ray burst that caused
伽马射线暴
a mass extinction
2.6 million years ago
也影响了地球的大气
also affected
Earth's atmosphere,
引发了巨大的闪电爆发
triggering tremendous
bursts of lightning,
引发了森林火灾
which caused forest fires.
哈基姆·奥卢西:我们有证据表明，此时发生了
HAKEEM OLUSEYI: We have
evidence of widespread fires
大面♥积♥火灾
at this time.
所以可能是闪电增加了
So it could be that
lightning was increased,
从而产生了更多的火灾
and that created more fires.
这些大火可能会夷平森林和热带矮树林
And those fires could have
leveled forests and savannas,