了解宇宙是如何运行的（2010）

How the Universe Works S05E05

Part 3 April 18, 2021, 7:47 p.m.

和恒星的引力其实完全一样
is exactly the same as the gravity of the star,
只要它不失去任何质量
as long as it hasn't lost any mass.
从一定距离来看，如果你绕着恒星运行
From a distance, if you're orbiting this star,
和绕着黑洞运行是一样的
it's the same as orbiting the black hole.
没有什么会改变
Nothing would change.
当这颗超级巨星坍塌时
As the supergiant star collapses,
从这颗遥远的行星上看到的景象
the view from the far-distant planet
将是超现实的
would be surreal.
你将会看到的是，你的主恒星高挂在天空中
What you're going to see is, there's your star in the sky,
然而一分钟后，它就消失了
and then a minute later, it's gone.
你会看到它塌缩
You will actually see it collapse,
形成一个黑洞，然后整个天体
forming a black hole, and the whole thing
就坍缩进去了，就是这样
just falls into it and that's that.
接下来将会是漫长的，缓慢的，寒冷的死亡
What would happen next would be a long, slow, cold death.
基本上你的主恒星已经被关掉了
You're basically turning off your star.
短暂的瞬间，却意味着冬季开始了
A fleeting moment, but the beginning of a winter
且永无尽头
that would never end.
如果突然关掉我们太阳的光芒
If you suddenly turned off the light from the sun,
生命实际上不会立即消失
life wouldn't actually be immediately extinguished.
就像夜晚一样
It would just be like the night.
可能会比平时更凉爽一点
We would be a little bit cooler than normal.
但最终，经过一段时间，几周，几个月
But eventually, over time, over weeks, over months,
几年，地球开始结冰
over years, the planet would begin to freeze over.
100年后，一个全球性的冰河时代
After 100 years, a global ice age
吞噬了地球
engulfs the planet.
首先是陆地，然后是海洋
First the land, then the oceans.
海洋会冻结成厚厚的地壳
The oceans would freeze over into a thick crust.
也许有一些液态水
Maybe a little bit of liquid water
仍然存在于海洋底部
would still be there at the bottom of the ocean,
被火山喷口加热
warmed by volcanic vents.
最终剩下的就是
Eventually what you're left with are things
那些不依赖阳光生存的生物
that don't depend on sunlight to live.
也许有管虫生活在火山口，裂缝
Maybe there are tube worms living in vents, cracks,
海底热液喷口
hydrothermal vents in the bottoms
或者海底其他类似的地方
of the oceans and that sort of thing.
但即使是这些也不可能永远存在
But even those can't possibly live forever.
这颗行星的内部热量
The internal heat of the planet
会待续向外太空辐射
continues to radiate out into space.
地表温度下降到
The surface temperature drops below
零下350华氏度以下
minus 350 degrees fahrenheit,
大气凝结成雪落在地表
and the atmosphere collapses onto the surface as snow.
地球的核心
The core of the planet
不再支持活跃的地质活动
can no longer support active geology.
所有的生命都会消失
All life is gone.
这个星球已经死亡
The planet is dead.
所以这些可居住的世界
So these habitable worlds will eventually end up
最终会变成这些冰球
being just these spheres of ice.
无论是被超新星的光杀死
Whether killed by the light of a supernova
还是被非新星的黑暗♥杀♥死
or by the darkness of an unnova,
行星都处在杀手恒星的枪口之上
planets are in the firing line from killer stars.
但最近公布的研究表明
But research recently released suggests that stars, too,
恒星也可能成为谋杀的受害者，其中一些谋杀事件
can fall victim to murder, and some of these killings
就像是直接从恐怖电影里出来的
are straight out of a horror movie.
一颗即将消亡的老恒星
How can an old star that's on the way to die
如何才能获得更多质量，从而重新变得年轻呢？
get more mass so it can become young again?
好吧，它也能做吸血鬼做的事情
Well, it can do exactly what a vampire does.
它可以从别的东西中吸取生命
It can suck life from something else.
2012年
2012.
哈勃太空望远镜有一个可怕的发现
The hubble space telescope makes a gruesome discovery.
它发现杀手恒星
It finds killer stars
正在吞噬它的邻居们的生命
sucking the life from their neighbors.
这些吸血鬼杀手潜伏在
These vampire killers are found lurking inside
被称为星团的紧密恒星群中
tightly packed groups of stars known as clusters.
恒星诞生于巨大的尘埃和气体云中
Stars are born in giant clouds of dust and gas,
这些云中有足够的物质
and these clouds have enough material
来形成几十个甚至数百个恒星
to make dozens or even hundreds of stars.
我们称这些恒星家族为星团
We call these family of stars star clusters,
我们认为它们的年龄大致相同
and we think they're all roughly the same age.
年轻的一簇簇像珠宝一样闪耀着
Young clusters shine like jewels,
闪耀着一排鲜艳的色彩……
with an array of bright colors ...
蓝色，黄色和红色
blues, yellows, and reds.
但这星光闪烁的彩虹会随着时间而改变
But this starry rainbow changes over time.
蓝色的星星首先消失
The blue stars disappear first.
这些是星团中最大的恒星
These are the biggest stars in the cluster,
明亮地燃烧数百万年后，并很快死去
burning brightly and dying young after millions of years.
接下来是黄色的恒星
Next to go are the yellow stars.
这些中等大小的恒星年龄超过数十亿年
These medium-sized stars age over billions of years,
逐渐变红，就像成熟的果实
gradually turning red like ripening fruit.
100亿年后
After 10 billion years,
整个星团成熟为深红色
the entire cluster matures to a deep red.
这种颜色的渐变对天文学家来说很有用
This gradual shift in color is useful to astronomers
因为它可以让他们判断一个星团的年龄
because it allows them to judge just how old a cluster is.
当你观察一个地方的恒星群时
When you look at a population of stars in one place,
如果你看到很多蓝色的恒星，你就可以确信
if you see a lot of blue stars, you can be pretty confident
那一定有年轻的恒星
that that must have young stars.
它们不可能诞生得太久
They couldn't have been born too long ago
因为蓝星质量很大
because blue stars are massive
而大质量恒星消耗燃料的速度很快
and massive stars go through their fuel quickly
寿命很短
and live very short lives.
20世纪50年代，天文学家
But in the 1950s, astronomers spotted
在一个古老的星系团中发现了非常奇怪的东西
something seriously weird in an ancient cluster.
在古老的红色恒星中间
Tucked amongst the old red stars,
他们发现了一些明亮的年轻的蓝色恒星
they found a handful of brightly shining young blue stars.
新恒星通常不会在成熟星团内部形成
New stars don't usually form inside mature clusters,
那么它们是如何形成的呢？
so how did they get there?
有唯一的解释吗？
The only explanation?
不知何故，老恒星变得越来越年轻
Somehow, the old stars were getting younger.
天文学家将这些抗老化的恒星称为
Astronomers dub these age-defying stars
蓝离散星
blue stragglers.
在一些星团中，我们看到这些蓝色的恒星
In some clusters, we see these blue stars
看起来比它们的实际年龄年轻
that appear younger than they should.
在某些方面，它们有点落后于
In some ways, they're kind of straggling behind
星系团的自然老化
the natural aging of the cluster.
一定有什么东西能积极地让恒星焕发青春
Something must be actively rejuvenating a star,
但怎么能做到呢？
but what could do that?
如果你把这些蓝色的星星想象成
If you imagine these blue straggler stars
人群中的人
were people in a crowd,
这些星星看起来就像做过整容手术一样
these stars would look like they had been given a facelift.
他们伪装成更年轻的恒星
They're masquerading as younger stars when really
但实际上他们和房♥间里的其他人一样老
they're just as old as everybody else in the room.
天体物理学家纳塔利·戈斯内尔认为
Astrophysicist Natalie gosnell
蓝色恒星是由于有了新的氢燃料供给
believed the blue stars were being rejuvenated
从而重新焕发活力
by a fresh supply of hydrogen fuel,
但氢燃料从何而来？
but where was it coming from?
2015年，娜塔莉对哈勃拍摄的
In 2015, Natalie took a closer look
蓝色离散星团照片进行了近距离地观察
at the hubble images of the blue straggler cluster.
她发现，大多数看起来年轻的恒星
She discovered that most of the young-looking stars
都是与死去恒星的尸体组成的双星伙伴关系
were in binary partnerships with the corpses of dead stars
这些死去恒星的气体似乎被吸走了
that appeared to have had their gas sucked away from them.
戈斯内尔: 在电影中
Gosnell: So in movies,
吸血鬼总是很年轻
vampires are perpetually youthful
因为他们从人类身上吸血
because they are sucking blood from humans,
所以在这个例子中，有恒星从其他恒星上
and so in this case, we have stars that are
吸取气体和物质
sucking gas and material from other stars,
并让它们看起来年轻
keeping them looking young.
气体是让所有恒星燃烧的燃料
Gas is the fuel that allows all stars to burn,
有了新的气体，一颗恒星就会重新焕发活力
and with new gas, a star is revitalized.
科学家们相信，一颗恒星如要变成
But for a star to turn into a gas-sucking vampire,
吸收气体的吸血鬼，它需要在近轨道双星中
scientists believe it needs to start its life
开始他的生命旅程
in a close-orbiting binary pair.