了解宇宙是如何运行的（2010）

How the Universe Works S05E05

Part 1 April 18, 2021, 7:47 p.m.

当太阳下山时
When the sun goes down,
怪物们就出来玩了
the monsters come out to play.
你看到的那些星星是真正的疯子
Some of those stars you see are actual psychos,
他们会杀了你
and they'll kill you.
在过去的十年里
In the last decade,
天文学家们发现了我们宇宙邪恶的一面
astronomers have uncovered a sinister side to our universe,
即具有
killer stars
毁灭宇宙力量的恒星杀手
with the power to destroy on a cosmic scale.
我们在电影里听说过死星（参见《星战》——译者注）
We hear about death stars in movies,
但在现实生活中它们确实存在
but they actually exist in real life.
太阳系会被撕成碎片
Solar systems torn to shreds,
生命世界也会瞬间蒸发
living worlds vaporized in an instant.
在宇宙的某个地方
Somewhere in the universe, dozens of worlds
有几十个和我们一样的世界
just like ours are being annihilated
正在被恒星杀手毁灭
by killer stars.
害怕黑暗吗？
Scared of the dark?
你应该害怕
You should be.
神秘的行星杀手
2015年6月
June 2015.
一台小型机器人望远镜正在扫描
A small robotic telescope scans the night sky
南美洲智利上空的夜空
over Chile, south America.
“全天空超新星自动探测仪”
The all sky automated survey for supernovas,
(简称asas-sn)
or asas-sn for short,
设定程序是发现标志着
is programmed to spot the bright flashes of light
巨星死亡的明亮闪光
that Mark the death of giant stars.
那天晚上，望远镜在天空中发现了
That night, the telescope found a faint glow in the sky
从未有人见过的微弱光芒
that nobody had seen before.
起初，天文学家认为它是附近的一颗超新星
At first, astronomers think it's a nearby supernova.
但当他们分♥析♥光线时
But when they analyze the light,
他们发现了一些不寻常的东西
they discover something extraordinary.
这颗正在爆♥炸♥的恒星遥远得难以想象
The exploding star was unimaginably far away,
近40亿光年的距离
nearly four billion light years.
因为是在如此遥远的距离观测到
To be visible from that mind-bending distance,
所以这道闪光必须打破记录
the flash of light had to be a record-breaker,
成为历史上最亮的超新星
the brightest supernova in recorded history.
它所辐射的能量比太阳
It radiated more energy than the sun
在其100亿年的生命中所辐射的能量还要多
will radiate in its entire 10 billion-year lifetime.
但它在一个月内就做到了
But it did that in a month.
这绝对达到了极限
This is at the absolute edge.
这是我们认为的最亮的超新星
This is the brightest we think a supernova can possibly be.
天文学家将这次破纪录的光爆♥炸♥
Astronomers name the record-breaking
命名为 asassn-15lh (字面意思是刺客——译者注)，这是一个恰当的名字
blast of light asassn-15lh, an appropriate name,
因为这颗超亮超新星
because this superluminous supernova
是一个大规模屠♥杀♥者
was a mass-murderer.
这颗超新星不仅会摧毁围绕这颗恒星运行的
This supernova isn't just going to destroy life
所有行星上的生命
on the planets that orbit that star.
它还会毁灭数百万行星上的生命
It's going to destroy life on millions of planets.
那可是数以百万计的天启事件
That's millions of apocalypse events.
15lh 的破坏力
The destructive power of 15lh
与爆♥炸♥力无关
had little to do with explosive force.
这种致命的暗♥杀♥武器就是“光”
This deadly assassin's weapon was light.
要了解“光”如何在银河系范围内
To understand how brightness
造成破坏的
can cause devastation on a galactic scale,
行星科学家妮娜·兰扎
planetary scientist Nina lanza
正在做一个大家熟悉的超大透镜实验
is supersizing a familiar backyard experiment.
所有进入这个巨大透镜的光
All the light entering this giant lens
都集中在这里的一点上
has been concentrated to a point right there,
直径大概是
which is maybe, you know,
半英寸到一英寸
half an inch to an inch in diameter.
看，我们已经…
And look, we're already ...
我们已经把木头烧起来了
we're already catching wood on fire,
太神奇了只有几秒钟的时间
so that's amazing. That was only a few seconds.
光是由被称为光子的
Light is made up of tiny packets
微小能量包组成的
of energy called photons,
这些光子越是集中
and the more concentrated these photons are,
它们的破坏作用就越大
the greater their destructive effect.
所以在这里，有非常多的光子
So right here, we have more photons.
你可以称之更亮
You can call this brighter.
在这个小点上的光线
It's much brighter in that little spot
要比镜头外的亮得多
than it is outside of the lens.
光亮让木头燃烧起来
So brightness is catching this wood on fire.
妮娜的透镜死亡射线
Nina's backyard death ray
比太阳还要亮几千倍
is thousands of times brighter than the sun,
至于超亮超新星 15lh 呢？
but the superluminous supernova 15lh?
它发出的是数千亿倍的强光
That shone hundreds of billions times brighter,
在密集的光子冲击下
an onslaught of photons so concentrated,
会使附近的行星
it would have vaporized the surfaces
表面汽化
of nearby planets
而更远的星球
and stripped away the atmospheres
则大气层消失
of more distant worlds,
一个真正的大规模星球杀手
a real-life mass-murdering planet-killer.
谁能保证？
And who knows?
也许被 15lh 摧毁的数百万个世界中的
Maybe some of the millions of worlds destroyed by 15lh
有一些可能已经有了我们这样的文明
could have had civilizations just like ours.
对于一个普通的超新星来说
For a normal supernova,
其毁灭半径大约是30光年
the kill radius is about 30 light years.
我们认为，如果超新星在30光年的
We think the intense uv radiation
范围内发生，那么来自超新星的
from a supernova will destroy the ozone on earth
强烈紫外线辐射将会破坏地球上的臭氧层
if the supernova happens within 30 light years.
像 2015lh 这样的超亮超新星
A superluminous supernova like 2015lh
比普通超新星要亮得多
is so much more luminous than a normal supernova
所以其毁灭半径也大得多
that the kill radius is much larger.
也许500光年
Maybe 500 light years
甚至1000光年
or even out to about 1,000 light years.
想象一下向各个方向
Imagine a volume of space
延伸1000光年的空间
stretching 1,000 light years in all directions.
这个空间可能有数亿颗恒星
It holds hundreds of millions of stars
或许还有数十亿个生命世界
and perhaps billions of living worlds.
只要在这片空间中♥央♥有一颗超亮超新星
Just one superluminous supernova in the center of this space
就足以将这片广袤的区域
is all it would take to wipe this vast region
完全抹去生命
completely clean of life.
当一颗恒星爆♥炸♥并摧毁它所在的恒星系时
It's violent enough when a single star blows up
就已经足够猛烈的了
and destroys its solar system,
但它们实际上可能是宇宙中
but these actually might be the true mass-murderers
真正的大屠♥杀♥者
of the universe.
那么一个巨恒星是如何演化成
So how do you turn a giant star
像 15lh 这样的超级杀手的呢？
into a mass-killer like 15lh?
迄今为止天文学家
Astronomers have observed
只观测到了几十颗超亮超新星
only a few dozen superluminous supernovas,
但他们认为它们形成的秘密在于高速旋转
but they think the secret to their formation is spin.
超亮超新星的起源
Superluminous supernovas start life
是被称为蓝色超级巨星的
as oversized bright-burning stars
超大亮度恒星
known as blue supergiants.
这些蓝色超级巨星挥霍得快，死得也早
These blue supergiants live fast and die young,
在1000万年的时间里就会消耗掉
burning through their fuel supply
它们的燃料供应
in just 10 million years.
当它们死亡时，它们的内核坍缩
As they die, their cores collapse to form
形成一个超密度的物体，称为中子星
a super-dense object called a neutron star,
如果这个中子星旋转得足够快
and if this neutron star is spinning fast enough,
它就会发展出强烈的磁场
it can develop intense magnetic fields,
从而演变成一种新的
transforming into something new
总体上更极端的天体……磁星
and altogether more extreme ... a magnetar.
所有的中子星都有非常非常强的磁场
All neutron stars have very, very intense magnetic fields,
但有时会产生一个真正的怪物
but sometimes a true monster is created.
磁场的强度其实是有上限的
There really is a limit to how powerful a magnetic field can be
只有强度达到上限之后才能成为磁星
before it starts to rip apart space and time itself,
并开始撕裂空间与时间
and right on the edge of that is a magnetar.
磁星就像得了类固醇的中子星
Magnetars are like neutron stars on steroids.
它们强烈的磁场会延伸到
Their intense magnetic fields reach out
即将消亡蓝超巨星的不断膨胀的外层气体层
into the expanding outer gas layers of the dying star,