宇宙时空之旅（2014）

Cosmos: A SpaceTime Odyssey S01E08

Part 5 April 25, 2021, 12:40 p.m.

但是对于恒星来说它的质量其实是有上限的
But there's an upper limit to how massive a star can be.
早在十七世纪当埃德蒙·哈雷
Back in the 17th century, when Edmond Halley
横跨赤道去绘制南天的星座时
crossed the equator to map the southern constellations,
海山二看起来就是一颗普通的暗星
Eta Carinae seemed like just another faint star.
但是在1843年海山二
But in 1843, Eta Carinae
突然变成了整个天空中第二亮的恒星
suddenly became the second brightest star in the sky,
只有天狼星比它亮
outshined only by Sirius.
从此以后它就处在失控的状态中
And it's been flipping out ever since.
那个正在膨胀的哑铃形的星云
That dumbbell-shaped cloud
就是那次爆发事件的产物
is the expanding remnant of that event.
在它的中心是一颗发疯的恒星
At its center is one crazy star.
这才叫不稳定
Talk about unstable--
海山二的质量至少是太阳的一百倍
Eta Carinae is at least 100 times more massive than the Sun,
每秒钟发出的光是太阳的五百万倍
and pouring out five million times more light.
它的质量已经接近了恒星质量的上限
It's pushing the upper limit of what a star can be.
而现在还有证据表明海山二有一个伴星
What's more, there's evidence that Eta Carinae
这个伴星的质量也非常大
is being gravitationally tormented by an evil twin--
它们通过引力互相绕转
another massive star in orbit around it
轨道距离就像土星到太阳
as close as Saturn is to the Sun.
一个超级巨大的恒星会发出如此巨量的光
The core of a supermassive star pours out so much light
以至于向外的压力会超过恒星本身的引力
that the outward pressure can overwhelm the star's gravity.
这样如果恒星过于巨大
If a star is too massive,
它的辐射压力就会超过它的引力
its radiation pressure overpowers its gravity
结果就是吹散自己
and blows the star apart.
海山二的命运在它百万年
The fate of Eta Carinae was sealed
诞生的时候就已经确定了
when it was born millions of years ago.
当它最终真的爆发了的时候
When it finally does blow up--
谁知道呢说不定已经爆发了
and who knows, maybe it already has;
毕竟我们看到的海山二的光
after all, we're looking at it by light that left the star
可是它7500年以前发出来的
7,500 years ago--
这场爆发将会是一场前所未见的灾难
it will be a cataclysm unlike anything we've seen before.
一个超超新星
A hypernova.
这爆发是如此的强大
An explosion so powerful,
超新星爆发跟它来比就好像是放烟花
it'll make a supernova seem like a firecracker by comparison.
如果海山二周围的恒星系统中
If there are nearby solar systems
有行星孕育出了生命那他们的日子就不久了
with planets harboring life, their days are numbered.
超超新星在爆发时会放出巨量的辐射
A hypernova spews so much radiation into space--
不仅是可见光还有X射线和伽马射线
not just light, but X-rays and gamma rays--
几十光年甚至是几百光年内行星的大气层
that planets that are dozens or perhaps hundreds of light-years away
都会被这辐射彻底蒸发
could be stripped of their atmospheres
而行星就会泡在这致命辐射中
and bathed in deadly radiation.
它会在邻近的几千个恒星系统中引发惊天灾难
It would wreak havoc in thousands of nearby star systems.
我猜现在啊你可能在问你自己
Right about now, you're probably asking yourself,
"我们安全么"
"Are we safe?"
如果海山二爆发的话
If Eta Carinae blows up,
地球会怎么样
what happens to Earth?
放心地球不会有问题的
Rest assured, Earth will be just fine.
你想想我们距离海山二可是有7500光年
Remember, we're 7,500 light-years away from Eta Carinae.
就算是来自爆发的恒星
The intensity of radiation from a star,
恒星辐射强度
even an exploding star,
也会随着距离增加而急速衰减
falls off rapidly with distance.
不过海山二的爆发定会带来一场精彩表演
But still, Eta Carinae in its death throes will put on quite a show.
它会像第二个月亮一样
It will light up the night of the southern hemisphere
点亮整个南天
with the brightness of a second moon.
海山二将是恒星最美的绝唱
The most dramatic swan song a star can sing.
我们的祖先崇拜太阳
Our ancestors worshipped the Sun.
而这却不是因为他们无知
And they were far from foolish.
崇拜太阳和群星是有道理的
It makes good sense to revere the Sun and stars,
因为我们就是它们的后代
because we are their children.
岩石中的硅空气中的氧
The silicon in the rocks, the oxygen in the air,
DNA中的碳摩天大楼中的铁
the carbon in our DNA, the iron in our skyscrapers,
首饰当中的银
the silver in our jewelry
都是在几十亿年以前在恒星中产生的
were all made in stars billions of years ago.
我们的行星我们的社会
Our planet, our society
甚至我们自己都是星尘
and we ourselves are stardust.
那么是什么让原子舞蹈
Well, what is it that makes the atoms dance?
一颗恒星的能量
How is the energy of a star transformed
是如何转化为世界上发生的事情
into everything that happens in the world?
什么是能量
What is energy?
我们就在能量之中
We're awash in it.
当太阳中的氢原子发生聚变时
When hydrogen atoms fuse inside the Sun,
它们就会产生氦原子
they make helium atoms.
而这聚变的过程就会发出一束能量
And this fusion emits a burst of energy
这能量在到达表面之前会在太阳内部
that can wander inside the Sun for ten million years
徘徊近千万年
before making its way to the surface.
而一旦到了表面它就会
And once there, it's free to fly
以可见光的形式从太阳飞向地球
straight from the Sun to the Earth as visible light.
如果这束光打到了树叶表面
If it should strike the surface of a leaf,
它就会在植物内部以化学能的形式储存起来
it will be stored in the plant as chemical energy.
日光
Sunshine...
变为月光
into moonshine.
干杯
干杯
我可以感觉到我的大脑在把葡萄酒的化学能
I can feel my brain turning the chemical energy of the wine
转化为思维的电能
into the electrical energy of my thoughts
并且引导着我的声带
and directing my vocal chords
来产生说话的声能
to produce the acoustic energy of my voice.
这种能量转化形式
Such transformations of energy
无时无刻无处不在地在发生着
are happening everywhere all the time.
来自于太阳的能量驱动着地球上的风浪
Energy from our star drives the wind and the waves
还有我们所有的生命
and the life around us.
能有无穷无尽的洁净能源像甘露一样从天而降
How lucky we are to have this vast source of clean energy
对我们来说是一件多么幸运的事情
falling like manna from heaven on all of us.
敬安妮·詹普·坎农
To Annie Jump Cannon,
亨利埃塔·斯万·勒维特
Henrietta Swan Leavitt
还有塞西莉亚·佩恩
and Cecilia Payne
感谢她们点亮了通向现代天体物理学之路
for blazing the trail to modern astrophysics.
同时敬所有太阳的姐妹
And to all the sisters of the Sun.
在这个宇宙中没有东西能一成不变
There's no refuge from change in the cosmos.
大概在一千万到二千万年之后
Some ten or 20 million years from now,
宇宙中的一瞬间
it'll seem for a cosmic moment
看起来俄里翁将会最终追到七姐妹
as if Orion is finally about to catch the seven sisters.
但是在他能伸出最后的魔爪之前
But before he has them in his clutches,
猎户座中最大的一颗星会超新星爆发
the biggest stars of Orion will go supernova.
俄里翁对昴星七姐妹的追逐也终将结束
Orion's pursuit of the Pleiades will finally end,
而这七姐妹
and the seven sisters
也将最终静静地滑入银河系的怀抱当中
will glide serenely into the waiting arms of the Milky Way.
地球上的我们
We on Earth marvel-- and rightly so--
总会为太阳的升起感到惊喜
at the return of our solitary Sun.
但如果有行星环绕着
But from a planet orbiting a star
遥远的球状星团里的某颗恒星
in a distant globular cluster,
那么它将见到更精彩的黎明
a still more glorious dawn awaits.
并不是一次日出
Not a sunrise...
而是一个星系将升起
but a galaxy rise.
一个拥有两千亿颗恒星的早晨
A morning filled with 200 billion suns.
银河系的升起
The rising of the Milky Way.
一个巨大的漩涡伴随着塌缩的气体云
An enormous spiral form with collapsing gas clouds,
凝结的行星系统明亮的超巨星
condensing planetary systems, luminous supergiants,
稳定的中年太阳红巨星白矮星
stable middle-aged suns, red giants, white dwarfs,
行星状星云超新星
planetary nebulas, supernovas,
中子星脉冲星黑洞
neutron stars, pulsars, black holes
同时我们也有足够的理由去相信
and, there is every reason to think,
还有亟待我们去发现的其它奇异天体
other exotic objects that we have yet to discover.
在这样高于银河系平面的世界中
From such a world, high above the Milky Way,
一切都很明了
it would be clear,
就好像我们现在慢慢开始理解的一样
as it is beginning to be clear on our world,
那就是我们是由原子和恒星所构成
that we are made by the atoms and the stars,
组成我们的物质和我们的形式
that our matter and our form
是由这伟大而古老的宇宙所锻造
are forged by the great and ancient cosmos,
而我们也是这宇宙的一部分
of which we are a part.