了解宇宙是如何运行的（2010）

It's kind of amazing
黑洞存在于理论的构造中
that Black Holes existed as theoretical constructs
很多物理学家牵涉其中
that many of the physicists who were involved
在这理论发展过程中他们并不相信
in developing those constructs didn't believe in.
现在 我们明白 也许
Now, we understand that even perhaps
我们的存在依赖于黑洞
our very existence depends upon them.
它们从我们想像中的物体
They've gone from objects in our imagination
成为我们的生活得以依存的物体
to objects on which our life depends.
尽管星系中心的黑洞
Even though this Black Hole in the center
在想像中很恐怖
is terrifying to conceive of,
事实上 银河系依赖于它
in fact, our galaxy depends on it.
我们的地球和太阳
And our own planet and star
因黑洞而形成
may have formed because of this system.
一百三十亿年前
13 billion years ago,
银河系首批恒星诞生
the first stars of the Milky Way spark into life.
银河系开始成形
The galaxy starts to take shape.
现在银河系足够大 盛气凌人
The Milky Way is now big enough to throw its weight around.
在早期宇宙 银河系并不孤单
And in the early universe, the Milky Way is not alone.
宇宙邻居成为它捕食对象
Its cosmic neighbors become its prey.
银河系变成同类相食的动物
The Milky Way becomes a cannibal.
年轻的银河系在成长
The young Milky Way is growing.
已经包含数百万颗恒星
It already contains millions of stars.
现在 银河系足够大 进入演化过程的下一阶段
Now, it's big enough to enter its next stage of evolution.
这是狂暴的时代
It's time to get violent.
银河系开始对兄弟姐妹感兴趣
Our galaxy turns on its cosmic siblings.
星系光彩夺目
Galaxies are gorgeous,
是巨大的焰火轮
huge pinwheels
优雅的螺旋形遍布宇宙
spiraling elegantly throughout the universe.
但这些星系有黑暗面
But there's a dark side to these galaxies.
创建星系的过程是同类相食的过程
The process of building up galaxies is one of cannibalism.
星系尚未形成大体量的群体
The galaxies don't form a mass as large objects.
像很多事物一样 它们要做的就是
What they do, like many things,
通过蚕食较小的群体发展自身
is form by eating smaller objects.
如果我们观察幼年宇宙
If we could view the infant universe,
我们会看到狂暴的战争
we would see a battle raging.
小的星系碰撞、合并
Dwarf galaxies collide and merge.
在这个舞台 体形大说了算
And in this arena, size matters.
这是一场宇宙的轮滑赛
It's a cosmic Roller-Derby match.
选手代表
The players represent Dwarf galaxies
居住在早期宇宙的小星系
which populate the early universe.
如果你观看轮滑比赛
If you look at a Roller-Derby match,
你会更好地了解星系的形成
you might get a better idea about what galaxy formation's like.
选手们绕溜冰场中♥央♥滑行
You've got people skating around the middle of a rink.
有人四处乱撞
There's people slamming all over the place.
很狂暴 场面一片混乱
It's a very violent process, really chaotic.
围绕星系周围也是这样
And it's exactly the same way around the galaxy.
在星系中 你站在中间
In a galaxy, you've got this middle
正在吸引一切
that's attracting everything,
物质漂浮四周
and stuff is swimming around it.
小星系彼此相撞
Dwarf galaxies smash into one another.
较大的总是占上风
The larger always get the upper hand.
你会吃掉这些不断冲撞的家伙
You've got all this stuff slamming together.
恒星被抛得到处都是
Stars are getting thrown all over the place.
它们从对方剥离物质 它们相撞
They strip mass from each other. They collide.
如果中间有较小的对象
And if there are any smaller objects in-between,
会立刻被吃掉
they get eaten up.
这场大破坏历时数十亿年
It's billions of years of destructive mayhem.
这是一场疯狂、暴烈之舞
It's just this crazy, violent dance
一遍又一遍上演
that just goes on over and over again.
在这场混乱的大碰撞中
In the chaos of collisions,
银河系变得更大
the Milky Way grows bigger.
今天 银河系成为宇宙中重要的成员
Today, our galaxy dominates our part of the universe.
即使现在 它还在吞噬其它的星系
And even now, it's still devouring other galaxies.
有星系叫人马座
There is a galaxy called Sagittarius
它在银河系周围 留有巨大的恒星的尾迹
which has left a huge trail of stars around the Milky Way
它处在被吞没的过程中
and is essentially in the process of being devoured.
有巨大的恒星流在脱离它
There's a giant stream of stars coming off of it.
它正在从整体上
So it's totally just being ripped apart
被银河系撕裂
by the Milky Way itself.
在这场战争中
But in this battle,
银河系毫发未损
the Milky Way doesn't go unscathed.
可能是这场大碰撞触发了
This collision could've triggered the formation
银河系旋臂的形成
of the spiral arms of the Milky Way itself.
所以银河系成为螺旋星系的原因
So the reason why the Milky Way is a spiral galaxy
可能就是由于它在吞噬人马座
might be because it's eating up Sagittarius.
狂暴不只是建造了银河系
Violence doesn't just build our galaxy.
它也塑造了银河系
It sculpts it,
使银河系成形
smashing the Milky Way into shape
重新布置恒星的位置
and rearranging the positions of the stars,
也许还包括我们太阳
perhaps even our sun.
可能太阳本来诞生在
It's possible that the sun was actually born
离银河系中心比较近
much closer to the middle of the galaxy,
在过去的二十亿年期间
and it's migrated out here to the suburbs
被重新布置到现在郊区的位置
over the course of the last couple billion years.
可能是人马座撞击了银河系
And it's possible that when Sagittarius hit the disk,
产生了旋臂
it created some spiral arms
然后令太阳向外移♥动♥
that then allowed the sun to migrate out.
太阳和我们太阳系
The sun and our solar system
现在距银河系中心二万六千光年
are now about 26,000 light-years from the galaxy's center.
对于地球上的生命来说 是个好消息
For life on earth, that's good news.
如果离星系中心的大黑洞太近
If you're too close to the big Black Hole in the center,
会有许多损害生命的事情发生
there's a lot going on that can actually hurt life.
有高能量辐射
There's high-energy radiation.
有恒星构造的爆♥炸♥ 超新星大爆♥炸♥
There are bursts of star formation, supernova explosions.
我们生活在安静的银河系边远的郊外
We're in a quieter, kind of outlying suburb of the galaxy.
有更多有助于生命的东西
And things there are much more conducive to life.
银河系的同类相食
Our galaxy's cannibalism
正是地球生物的本性
proves essential for life on earth.
尽管狂暴 我们却得以相安无事
Through violence, we're able to live,
银河系继续成长
and our galaxy continues to grow.
有什么能阻止
But can anything stop
银河系的同类相食吗？
the juggernaut of our cannibal galaxy?
放眼银河系
Looking out at the Milky Way,
天文学家难以发现新恒星
astronomers find hardly any new stars.
有东西在阻止银河系的成长
Turns out, something is shutting our galaxy's growth down,
宇宙最大的喷火器
the biggest flamethrower in the universe.
银河系起初较小
The Milky Way started small.
经过几十亿年 银河系长大
Over billions of years, it has grown huge,
生产出二千多亿颗恒星 并且还在增加
spawning over 200 billion stars and counting.
但计数正在变慢
But the count is slowing.
目前的银河系
So, in the Milky Way right now,
仍有恒星在诞生
there are stars that are being born.
大约每年一颗恒星
And there's about one star per year
在我们银河系某个地方诞生
somewhere in our giant galaxy that's being born.
在银河系 恒星建造尚未结束
Star formation's not done in the Milky Way,
但已经慢下来
but it's settled down.
在过去 银河系
In its past, the Milky Way
爆发式创建恒星
was bursting with star formation.
是什么在改变？
So what's changed?
今天星系形成最大的谜团之一就是
So, one of the big questions in galaxy formation today is,
为什么更多的气体没有转变为恒星？
why isn't more gas turning into stars?
一条线索就是黑洞
Well, one clue is that Black Holes
黑洞也许在限制这个过程
actually might be limiting this process.
在早期宇宙
In the early universe,
我们的黑洞也许触发了恒星的诞生
our Black Hole may have sparked stars into life.
现在它也许在阻止恒星的形成
Now, it might be stopping stars from forming.
要找到原因 我们需要
To find out why, we need to look
详细的审视银河系的超大质量黑洞
at the Milky Way's supermassive Black Hole in detail.
第一次 我们能做到
And for the first time, we can,
感谢太空总署最新的太空望远镜之一 核光谱望远镜阵列
thanks to one of NASA's newest space telescopes, NuSTAR.
菲奥娜.哈里森负责执行NuSTAR任务