TEDGlobal 2009
Andrea Ghez: The hunt for a supermassive black hole
安德里亚·盖兹: 寻找超大质量黑洞
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基于凯克(Keck)望远镜的新数据，安德里亚·盖兹向我们展示了使用最尖端特技的自适应光学系统如何帮助天文学家去了解广袤宇宙中最神秘的物体：黑洞。她也出示了银河系中心可能潜伏着一个超大质量的黑洞的证据。
Andrea Ghez - Astronomer
Andrea Ghez is a stargazing detective, tracking the visible and invisible forces lurking in the vastness of interstellar space. Full bio
Andrea Ghez is a stargazing detective, tracking the visible and invisible forces lurking in the vastness of interstellar space. Full bio
Double-click the English transcript below to play the video.
00:15
How do you observe something you can't see?
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如何观察那些你看不见的东西？
00:18
This is the basic question of somebody who's interested
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对于有兴趣寻找和研究黑洞的人来说，
00:21
in finding and studying black holes.
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这是个根本问题。
00:23
Because black holes are objects
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因为黑洞的引力极为强大，
00:25
whose pull of gravity is so intense
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任何物体
00:28
that nothing can escape it, not even light,
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包括光线，都不能逃脱。
00:30
so you can't see it directly.
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所以你不能直接看到它。
00:32
So, my story today about black holes
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我今天要讲的黑洞
00:35
is about one particular black hole.
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是关于一种特别的黑洞。
00:37
I'm interested in finding whether or not
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我的兴趣在于是否
00:40
there is a really massive, what we like to call
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存在一个特别巨大，我们称之为“超大质量黑洞”
00:43
"supermassive" black hole at the center of our galaxy.
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的黑洞存在银河系中心。
00:46
And the reason this is interesting is that
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感兴趣的原因是
00:49
it gives us an opportunity to prove
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这将给我们一个机会去证明
00:52
whether or not these exotic objects really exist.
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是否这些奇特的物体是否真的存在。
00:56
And second, it gives us the opportunity
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其次，这给我们一个机会
00:58
to understand how these supermassive black holes
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去了解这些特大质量黑洞是如何
01:01
interact with their environment,
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与他们的环境进行互动，
01:03
and to understand how they affect the formation and evolution
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以及它们是如何影响到
01:06
of the galaxies which they reside in.
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所处宇宙的形成和演化
01:09
So, to begin with,
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言归正传，
01:11
we need to understand what a black hole is
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首先，我们必须理解黑洞是什么，
01:14
so we can understand the proof of a black hole.
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这样我们才能理解黑洞存在的证据。
01:16
So, what is a black hole?
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那么，黑洞是什么？
01:18
Well, in many ways a black hole is an incredibly simple object,
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从很多方面来说，黑洞是个简单到不可思议的物体，
01:22
because there are only three characteristics that you can describe:
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它只有三个特征可以测量：
01:25
the mass,
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质量
01:27
the spin, and the charge.
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角动量和电荷。
01:29
And I'm going to only talk about the mass.
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而我将只讨论质量。
01:31
So, in that sense, it's a very simple object.
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从这个意义上来说，它是非常简单的物体。
01:34
But in another sense, it's an incredibly complicated object
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但是，换个角度，它又是极其复杂的，
01:36
that we need relatively exotic physics to describe,
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以至于我们需要相对来说比较奇特的物理学来描述，
01:39
and in some sense represents the breakdown of our physical understanding
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在某种程度上还标识着我们对于宇宙的的物理认知的崩溃。
01:43
of the universe.
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（）
01:45
But today, the way I want you to understand a black hole,
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如今，为了让你了解黑洞
01:47
for the proof of a black hole,
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了解黑洞存在的证据，
01:49
is to think of it as an object
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是把它看作一个
01:51
whose mass is confined to zero volume.
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质量为零的物体
01:54
So, despite the fact that I'm going to talk to you about
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尽管我将和你们谈谈关于
01:56
an object that's supermassive,
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超质量的物体
01:59
and I'm going to get to what that really means in a moment,
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而对于这个物体，我将在后面进行阐述
02:01
it has no finite size.
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它没有大小。
02:04
So, this is a little tricky.
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这有点棘手。
02:06
But fortunately there is a finite size that you can see,
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但幸运的是你可以看到有限的大小，
02:10
and that's known as the Schwarzschild radius.
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这被称为史瓦西半径
02:13
And that's named after the guy who recognized
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它命名于史瓦西
02:15
why it was such an important radius.
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他发现了为什么这个半径是如此重要
02:17
This is a virtual radius, not reality; the black hole has no size.
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这是一个虚拟的半径，而不是真实的；黑洞没有大小
02:20
So why is it so important?
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那么，为什么这很重要呢？
02:22
It's important because it tells us
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它重要是因为它告诉我们
02:24
that any object can become a black hole.
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任何物体都可以成为黑洞
02:28
That means you, your neighbor, your cellphone,
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这意味着你的邻居，你的手机，
02:31
the auditorium can become a black hole
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还有礼堂都能成为黑洞
02:33
if you can figure out how to compress it down
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如果你能弄明白
02:36
to the size of the Schwarzschild radius.
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如何把它压缩至史瓦西半径大小。
02:38
At that point, what's going to happen?
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在这一点上，会发生什么？
02:41
At that point gravity wins.
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在这一点上，引力获胜。
02:43
Gravity wins over all other known forces.
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引力胜过其他所有已知力量
02:45
And the object is forced to continue to collapse
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物体被迫继续坍塌
02:48
to an infinitely small object.
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成为一个奇点。
02:50
And then it's a black hole.
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这就是黑洞。
02:52
So, if I were to compress the Earth down to the size of a sugar cube,
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如果把地球压缩至一块方糖大小，
02:57
it would become a black hole,
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地球就会成为一个黑洞
02:59
because the size of a sugar cube is its Schwarzschild radius.
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因为方糖的大小是它的史瓦西半径。
03:03
Now, the key here is to figure out what that Schwarzschild radius is.
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现在，关键是要弄清楚什么是史瓦西半径。
03:06
And it turns out that it's actually pretty simple to figure out.
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事实证明，这很容易算出来
03:10
It depends only on the mass of the object.
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它只依赖于物体的质量。
03:12
Bigger objects have bigger Schwarzschild radii.
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更大的物体有更大的是史瓦西半径。
03:14
Smaller objects have smaller Schwarzschild radii.
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更小的物体有更小的史瓦西半径。
03:17
So, if I were to take the sun
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因此，如果我把太阳
03:19
and compress it down to the scale of the University of Oxford,
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压缩至英国牛津大学的大小，
03:22
it would become a black hole.
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太阳会成为一个黑洞。
03:25
So, now we know what a Schwarzschild radius is.
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现在，我们知道了什么是史瓦希半径。
03:28
And it's actually quite a useful concept,
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它实际上是一个相当有用的概念，
03:30
because it tells us not only
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因为它不仅告诉我们
03:32
when a black hole will form,
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黑洞何时形成，
03:34
but it also gives us the key elements for the proof of a black hole.
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同时还带给我们黑洞存在证据的关键要素。
03:37
I only need two things.
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我只需要两件东西。
03:39
I need to understand the mass of the object
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我需要了解物体的质量
03:41
I'm claiming is a black hole,
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我自称是一个黑洞，
03:43
and what its Schwarzschild radius is.
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以及其史瓦西半径。
03:45
And since the mass determines the Schwarzschild radius,
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由于质量决定史瓦西半径，
03:47
there is actually only one thing I really need to know.
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实际上只有一件事我需要知道。
03:49
So, my job in convincing you
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因此，我的工作是说服你
03:51
that there is a black hole
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那有一个黑洞，
03:53
is to show that there is some object
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表明有一些物体
03:55
that's confined to within its Schwarzschild radius.
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仅限于其史瓦西半径·
03:58
And your job today is to be skeptical.
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而你要做的是对此表示怀疑。
04:01
Okay, so, I'm going to talk about no ordinary black hole;
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好了，我要谈的不是常规黑洞；
04:05
I'm going to talk about supermassive black holes.
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我要谈论的是超大质量黑洞。
04:08
So, I wanted to say a few words about what an ordinary black hole is,
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因此，我要说常规黑洞是什么
04:10
as if there could be such a thing as an ordinary black hole.
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好像有这样一个可以作为常规黑洞的东西。
04:13
An ordinary black hole is thought to be the end state
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一个常规黑洞可以被看作是
04:16
of a really massive star's life.
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大质量恒星生命的晚期。
04:18
So, if a star starts its life off
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因此，当一个恒星消亡
04:20
with much more mass than the mass of the Sun,
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而这个恒星的质量远大于太阳
04:22
it's going to end its life by exploding
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它将以爆炸结束生命
04:25
and leaving behind these beautiful supernova remnants that we see here.
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我们将会看到留下的超新星遗骸
04:28
And inside that supernova remnant
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在超新星遗骸的内部
04:30
is going to be a little black hole
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形成一个小型黑洞
04:32
that has a mass roughly three times the mass of the Sun.
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质量大概是太阳的3倍。
04:35
On an astronomical scale
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从天文学的角度来看
04:37
that's a very small black hole.
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这是一个非常小的黑洞
04:39
Now, what I want to talk about are the supermassive black holes.
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现在，我想谈谈超大质量黑洞。
04:42
And the supermassive black holes are thought to reside at the center of galaxies.
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超大质量黑洞被认为位于星系中心。
04:46
And this beautiful picture taken with the Hubble Space Telescope
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这幅美丽的图片是哈勃太空望远镜拍摄的
04:49
shows you that galaxies come in all shapes and sizes.
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展示了星系的所有形状和大小。
04:52
There are big ones. There are little ones.
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有大的，有小的。
04:54
Almost every object in that picture there is a galaxy.
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几乎图片上的每一个物体都是一个星系。
04:57
And there is a very nice spiral up in the upper left.
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有一个非常漂亮的螺旋臂在左上角。
05:00
And there are a hundred billion stars in that galaxy,
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有100亿颗恒星在那个星系中，
05:04
just to give you a sense of scale.
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仅仅给你一种规模感。
05:06
And all the light that we see from a typical galaxy,
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我们从一个典型的星系中看到的所有光线，
05:08
which is the kind of galaxies that we're seeing here,
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是我们在这儿看到的星系中的一种，
05:10
comes from the light from the stars.
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来自恒星的光线。
05:12
So, we see the galaxy because of the star light.
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我们看见星系是因为恒星的光。
05:14
Now, there are a few relatively exotic galaxies.
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有一些比较奇特的星系
05:18
I like to call these the prima donna of the galaxy world,
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我喜欢称这些星系为女主角，
05:21
because they are kind of show offs.
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因为它们特别愿意展示自己
05:23
And we call them active galactic nuclei.
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我们称之为活跃星系核心。
05:25
And we call them that because their nucleus,
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我们之所以这样称呼是因为它们的核心，
05:27
or their center, are very active.
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或者它们的中心，非常活跃。
05:30
So, at the center there, that's actually where
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在中心位置，
05:32
most of the starlight comes out from.
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大部分星光是从那发出的。
05:34
And yet, what we actually see is light
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然而，事实上我们看到的是
05:36
that can't be explained by the starlight.
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无法用星光来解释的光
05:39
It's way more energetic.
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它比星光更有活力。
05:41
In fact, in a few examples it's like the ones that we're seeing here.
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事实上，下面的例子中跟我们现在看的这些有些相似。
05:43
There are also jets emanating out from the center.
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也是从中心喷射出。
05:46
Again, a source of energy that's very difficult to explain
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如果你仅仅认为星系是由恒星组成的
05:50
if you just think that galaxies are composed of stars.
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那这股能量的来源就很难解释了。
05:52
So, what people have thought is that perhaps
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人们认为
05:54
there are supermassive black holes
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也许有超大质量黑洞
05:57
which matter is falling on to.
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所以物质被吸引过去。
06:00
So, you can't see the black hole itself,
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你不能看见黑洞本身，
06:02
but you can convert the gravitational energy of the black hole
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但是你能将黑洞的引力
06:05
into the light we see.
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转换为我们能见的光。
06:07
So, there is the thought that maybe supermassive black holes
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因此，有一种想法就是
06:09
exist at the center of galaxies.
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也许超大质量黑洞存在于星系的中心。
06:11
But it's a kind of indirect argument.
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但这仅是一种间接论据。
06:13
Nonetheless, it's given rise to the notion
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尽管如此，这却带来了一种概念
06:15
that maybe it's not just these prima donnas
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也许不仅是这些主角
06:18
that have these supermassive black holes,
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有超大质量黑洞
06:20
but rather all galaxies might harbor these
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而是所有的星系中心
06:23
supermassive black holes at their centers.
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都有可能藏匿超大质量黑洞
06:25
And if that's the case -- and this is an example of a normal galaxy;
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如果是这种情况——这是一个常规星系的例子；
06:28
what we see is the star light.
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我们看到的是星光。
06:30
And if there is a supermassive black hole,
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如果有超大质量黑洞，
06:32
what we need to assume is that it's a black hole on a diet.
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我们需要假设的是它是一个正在节食的黑洞。
06:35
Because that is the way to suppress the energetic phenomena that we see
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因为这是一种我们所见到的压制现象
06:38
in active galactic nuclei.
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在活跃星系的核心
06:41
If we're going to look for these stealth black holes
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如果我们要在星系中心找寻
06:44
at the center of galaxies,
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这些隐藏的黑洞，
06:46
the best place to look is in our own galaxy, our Milky Way.
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最好的地方就是我们所在的星系，银河系。
06:50
And this is a wide field picture
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这是一张银河系中心的
06:52
taken of the center of the Milky Way.
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大范围图片
06:55
And what we see is a line of stars.
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我们看到的是线状的恒星系。
06:58
And that is because we live in a galaxy which has
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因为我们所在的星系
07:00
a flattened, disk-like structure.
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是一个扁平的，盘状结构的星系。
07:02
And we live in the middle of it, so when we look towards the center,
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而且我们居住在中央，因此当我们看向中心，
07:04
we see this plane which defines the plane of the galaxy,
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我们把这个平面看成是星系的平面，
07:06
or line that defines the plane of the galaxy.
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或者把这条线看成是星系的平面
07:10
Now, the advantage of studying our own galaxy
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研究我们自己的星系的优势是
07:13
is it's simply the closest example of the center of a galaxy
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在我们接触过的星系中心的实体中
07:16
that we're ever going to have, because the next closest galaxy
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这是距离我们最近的星系
07:18
is 100 times further away.
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我们的邻居星系距离我们则足有100倍的距离
07:21
So, we can see far more detail in our galaxy
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因此，对我们自身所在星系的研究可以做到比其他任何一个星体
07:23
than anyplace else.
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都更加透彻
07:25
And as you'll see in a moment, the ability to see detail
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就像我们马上就要谈到的
07:27
is key to this experiment.
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观察细节的能力对于我们这次实验至关重要
07:30
So, how do astronomers prove that there is a lot of mass
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这样一来
07:33
inside a small volume?
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宇航员如何才能证明一个相对小的空间内存在很大的质量呢
07:35
Which is the job that I have to show you today.
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这正是我今天想要向大家展示的
07:38
And the tool that we use is to watch the way
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我们将应用的工具就是
07:40
stars orbit the black hole.
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观测行星环绕黑洞的轨道
07:43
Stars will orbit the black hole
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行星环绕的黑洞的轨道
07:45
in the very same way that planets orbit the sun.
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与行星环绕太阳类似
07:48
It's the gravitational pull
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是重心牵引力
07:50
that makes these things orbit.
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使这些星体按照轨道运行
07:52
If there were no massive objects these things would go flying off,
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如果没有大质量的物体存在，这些星体都将四散而出
07:55
or at least go at a much slower rate
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或者说至少运动的速率对大幅下降
07:57
because all that determines how they go around
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这是因为，对它们如何运动起到决定性作用的是
08:00
is how much mass is inside its orbit.
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它的轨道内部存在多少的物质
08:02
So, this is great, because remember my job is to show
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我们必须要清楚这一点，因为我的工作就是
08:04
there is a lot of mass inside a small volume.
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证明一个小的空间内也存在大量的物质
08:06
So, if I know how fast it goes around, I know the mass.
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因此，如果可以计算出它的运行速度，我便可以推断出质量
08:09
And if I know the scale of the orbit I know the radius.
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更进一 步，如果可以知道轨道的范围，我们就可以计算出其半径
08:12
So, I want to see the stars
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这就是我希望可以尽可能选择
08:14
that are as close to the center of the galaxy as possible.
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接近星系中心星体的原因
08:16
Because I want to show there is a mass inside as small a region as possible.
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只有这样，我才能在尽可能小的空间内证实物质的存在
08:20
So, this means that I want to see a lot of detail.
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也就说明，我需要观测大量的细节数据
08:23
And that's the reason that for this experiment we've used
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这就是我们为何采用世界上最大的望远镜
08:25
the world's largest telescope.
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来做这个实验的原因
08:27
This is the Keck observatory. It hosts two telescopes
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这是keck天文台，它拥有2台镜头有10米长的望远镜
08:30
with a mirror 10 meters, which is roughly
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差不多
08:32
the diameter of a tennis court.
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是一个网球场直径的长度
08:34
Now, this is wonderful,
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这一点很赞
08:36
because the campaign promise
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因为大型望远镜总是承诺
08:38
of large telescopes is that is that the bigger the telescope,
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望远镜越大
08:41
the smaller the detail that we can see.
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我们能观察到越小的细节。
08:45
But it turns out these telescopes, or any telescope on the ground
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然而，我们却发现这些或现有的所有望远镜
08:48
has had a little bit of a challenge living up to this campaign promise.
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都与预期的表现有所差距
08:52
And that is because of the atmosphere.
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这是因为大气环境
08:54
Atmosphere is great for us; it allows us
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地球大气层对我们人类至关重要
08:56
to survive here on Earth.
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它保证了生命的存在
08:58
But it's relatively challenging for astronomers
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但是对天文学家来说，它却是相对有挑战性的，
09:01
who want to look through the atmosphere to astronomical sources.
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因为他们需要透过大气层来观测外部的世界
09:05
So, to give you a sense of what this is like,
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因此，为了让大家更好的理解
09:07
it's actually like looking at a pebble
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我用一个比喻
09:09
at the bottom of a stream.
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就像看一块小溪底的鹅卵石一样
09:11
Looking at the pebble on the bottom of the stream,
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在看河底的鹅卵石时
09:13
the stream is continuously moving and turbulent,
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溪水不断流动
09:16
and that makes it very difficult to see the pebble on the bottom of the stream.
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使得观察底部的鹅卵石变的很困难
09:20
Very much in the same way, it's very difficult
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同样的
09:22
to see astronomical sources, because of the
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正是因为大气层不停的流动
09:24
atmosphere that's continuously moving by.
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我们很难观测到清晰的外层
09:26
So, I've spent a lot of my career working on ways
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因此我花费了职业生涯中很长的时间来研究如何克服这一困难
09:29
to correct for the atmosphere, to give us a cleaner view.
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来给大家带来一个更清晰的视野
09:32
And that buys us about a factor of 20.
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这可以提高我们1／20的成功率
09:35
And I think all of you can agree that if you can
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我认为我们大家都认同这一点
09:37
figure out how to improve life by a factor of 20,
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如果可以提高生活质量1／20的水平
09:40
you've probably improved your lifestyle by a lot,
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那么整体的生活水平将获得很大的改善
09:42
say your salary, you'd notice, or your kids, you'd notice.
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拿薪水，或者你的孩子做个例子，你就会发现
09:47
And this animation here shows you one example of
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这个动画展示了
09:49
the techniques that we use, called adaptive optics.
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自适应光学的应用例子
09:52
You're seeing an animation that goes between
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你可以看到一个动画呈现
09:54
an example of what you would see if you don't use this technique --
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一幅你只有不应用这个技术才可以看到的画面
09:57
in other words, just a picture that shows the stars --
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换句话说，就是一幅星象图
10:00
and the box is centered on the center of the galaxy,
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这个方块位于整个星系的中心
10:02
where we think the black hole is.
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也就是黑洞的所在
10:04
So, without this technology you can't see the stars.
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因此，如果没有这项技术，我们无法看到星体
10:07
With this technology all of a sudden you can see it.
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应用这项技术我们可以突然的看到它们
10:09
This technology works by introducing a mirror
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这项技术在望远镜的光学系统中增加了一块反光镜
10:11
into the telescope optics system
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并通过这种原理进行工作
10:13
that's continuously changing to counteract what the atmosphere is doing to you.
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这将持续的改变你对大气层作用的看法
10:18
So, it's kind of like very fancy eyeglasses for your telescope.
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因此，这就像给你的望远镜带上一付花式眼镜
10:22
Now, in the next few slides I'm just going to focus on
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现在，接下的几幅幻灯片中，我们将主要观察
10:24
that little square there.
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那个小方块
10:26
So, we're only going to look at the stars inside that small square,
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我们将集中观测方块内部的星体
10:28
although we've looked at all of them.
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尽管我们已经观察到了全部
10:30
So, I want to see how these things have moved.
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我希望观测它们是如何运动的
10:32
And over the course of this experiment, these stars
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这个的实验过程中
10:34
have moved a tremendous amount.
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星体都运行了相当惊人的距离
10:36
So, we've been doing this experiment for 15 years,
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我们做这个实验已经进行了15年
10:38
and we see the stars go all the way around.
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我们了解这些星体的运行轨迹
10:40
Now, most astronomers have a favorite star,
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多数的天文学家都有自己最喜欢的一颗星
10:43
and mine today is a star that's labeled up there, SO-2.
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而我今天的最爱则是上边那棵标志着SO-2的星体
10:47
Absolutely my favorite star in the world.
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这棵星毫无疑问是我的最爱
10:49
And that's because it goes around in only 15 years.
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这是因为它的运行周期是15年
10:52
And to give you a sense of how short that is,
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为了表明这是一段极短的时间
10:54
the sun takes 200 million years to go around the center of the galaxy.
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我想说的是太阳需要200亿年才能环绕星系一周
10:59
Stars that we knew about before, that were as close to the center of the galaxy
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我们以前所了解的尽可能的靠近星系中心的星体
11:02
as possible, take 500 years.
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需要500年来完成同样的环绕
11:04
And this one, this one goes around in a human lifetime.
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然而这一颗星，可以在一个人的生命中就完成环绕
11:08
That's kind of profound, in a way.
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这也可以看成是另类的深邃吧
11:10
But it's the key to this experiment. The orbit tells me
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这一点是这次实验的关键
11:12
how much mass is inside a very small radius.
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运行轨道能可以告诉我在一个短半径内究竟存在多少物质
11:16
So, next we see a picture here that shows you
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因此，接下来我们将看一幅照片
11:19
before this experiment the size to which we could
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它展示了在这个实验之前，我们能够
11:21
confine the mass of the center of the galaxy.
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证实这个星系中心的物质的大小
11:24
What we knew before is that there was four million
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我们之前所了解到的是有
11:26
times the mass of the sun inside that circle.
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超过太阳四亿倍的质量
11:29
And as you can see, there was a lot of other stuff inside that circle.
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我们可以看到，这个轨道内还有很多其它的东西
11:31
You can see a lot of stars.
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有很多的星体。
11:33
So, there was actually lots of alternatives
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所以，对于星系中心存在着巨大黑洞的假设
11:35
to the idea that there was a supermassive black hole at the center of the galaxy,
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也就存在了很多可能性,
11:38
because you could put a lot of stuff in there.
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因为你可以假设各种各样的物质的存在
11:40
But with this experiment, we've confined
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但是通过这次实验
11:42
that same mass to a much smaller volume
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我们证明了在小一些空间的同样的物质
11:45
that's 10,000 times smaller.
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缩小了1万倍
11:49
And because of that, we've been able to show
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正因为如此，我们才能看到
11:51
that there is a supermassive black hole there.
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存在着一个巨型黑洞
11:53
To give you a sense of how small that size is,
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究竟有多小
11:55
that's the size of our solar system.
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这是太阳系的大小
11:57
So, we're cramming four million times the mass of the sun
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我们把4亿倍太阳物质
12:01
into that small volume.
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塞进这个小空间里
12:03
Now, truth in advertising. Right?
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真相出现
12:06
I have told you my job is to get it down to the Schwarzchild radius.
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我曾说过我的工作是要把它缩小到史瓦西半径的范围
12:09
And the truth is, I'm not quite there.
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但事实上，我还没有达到那个程度
12:11
But we actually have no alternative today
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但是我们目前为止已经没有其它更好的方法
12:13
to explaining this concentration of mass.
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来解释物质的聚集程度
12:16
And, in fact, it's the best evidence we have to date
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事实上，这是我们目前所拥有的最好的证据
12:19
for not only existence of a supermassive black hole
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不仅因为我们星系中存在的巨大黑洞
12:21
at the center of our own galaxy, but any in our universe.
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在我们的整个宇宙也存在
12:24
So, what next? I actually think
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下一步是什么呢
12:27
this is about as good as we're going to do with today's technology,
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我曾经想过这一切都关于我们如何更好的应用现有的科技手段
12:29
so let's move on with the problem.
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因此让我们来继续这个问题
12:31
So, what I want to tell you, very briefly,
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简而言之，我想说的是
12:33
is a few examples
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这几个例子
12:35
of the excitement of what we can do today
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代表着我们今天所能达到的水平
12:37
at the center of the galaxy, now that we know that there is,
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在星系的中心，现在我们确认
12:39
or at least we believe,
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或者说至少我们相信
12:41
that there is a supermassive black hole there.
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存在一个巨型黑洞
12:43
And the fun phase of this experiment
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这次实验的有趣之处就在于
12:45
is, while we've tested some of our ideas
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在我们测试
12:48
about the consequences of a supermassive black hole
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有关巨型黑洞位于星系中心的后果
12:50
being at the center of our galaxy,
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的新想法时
12:52
almost every single one
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基本上任何一个新想法
12:54
has been inconsistent with what we actually see.
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都没有局限在我们所能看到的
12:56
And that's the fun.
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这就是乐趣所在
12:58
So, let me give you the two examples.
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现在我将给出2个例子
13:00
You can ask, "What do you expect
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你可以问
13:02
for the old stars, stars that have been around the center of the galaxy
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“你对那些很古老的星体，那些已经围绕星系中心很久的星体
13:04
for a long time, they've had plenty of time to interact with the black hole."
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有足够长的时间与黑洞产生互动的那些有什么预期。”
13:08
What you expect there is that old stars
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你所期望看到的是
13:10
should be very clustered around the black hole.
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那些古老的星体应该环绕在黑洞附近逐渐接近
13:12
You should see a lot of old stars next to that black hole.
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你将可以看到黑洞附近聚集很多星体
13:16
Likewise, for the young stars, or in contrast, the young stars,
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相似的或者相反的，对于年轻的星体，
13:20
they just should not be there.
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它们则不应该出现在那个地方
13:22
A black hole does not make a kind neighbor to a stellar nursery.
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黑洞不会是恒星摇篮的好邻居
13:26
To get a star to form, you need a big ball of gas and dust to collapse.
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一个星体的形成需要大量的气体与尘埃的崩溃与聚合
13:30
And it's a very fragile entity.
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它是一个非常脆弱的个体
13:32
And what does the big black hole do?
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黑洞在这起到什么作用呢
13:34
It strips that gas cloud apart.
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它可以将气云剥离
13:36
It pulls much stronger on one side than the other
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它对一面起到更大的拉力
13:38
and the cloud is stripped apart.
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从而把气云剥离
13:40
In fact, we anticipated that star formation shouldn't proceed in that environment.
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事实上 我们预测 星体的形成不应该在那种环境下发生
13:43
So, you shouldn't see young stars.
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所以你不应看到年轻的星体
13:45
So, what do we see?
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那么我们到底看到了什么
13:47
Using observations that are not the ones I've shown you today,
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使用其它一些观察设施
13:49
we can actually figure out which ones are old and which ones are young.
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我们可以发现年老或者年轻的星体
13:52
The old ones are red.
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年长的星体呈现红色
13:54
The young ones are blue. And the yellow ones, we don't know yet.
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而年轻的星体则是蓝色 至于黄色的星体，我们还未知
13:57
So, you can already see the surprise.
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你应该也已经感到很吃惊了
13:59
There is a dearth of old stars.
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年长的星体很少
14:01
There is an abundance of young stars, so it's the exact opposite of the prediction.
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却有着很多的年轻星体 这与我们的预测恰恰相反
14:05
So, this is the fun part.
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这也是有趣的地方
14:07
And in fact, today, this is what we're trying to figure out,
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事实上 这也是我们试图揭开的一个谜团
14:09
this mystery of how do you get --
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一个有关
14:11
how do you resolve this contradiction.
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我们如何可以解决这个完全相反的结论
14:13
So, in fact, my graduate students
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所以实际上，我的硕士生们
14:15
are, at this very moment, today, at the telescope,
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正在夏威夷的天文观测站
14:19
in Hawaii, making observations to get us
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进行观测
14:22
hopefully to the next stage,
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希望能我们可以很快的进入下一个阶段
14:24
where we can address this question
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那时我们将重新阐释这个问题
14:26
of why are there so many young stars,
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也就是为什么有这么多的年轻星体
14:28
and so few old stars.
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而老年星体则如此稀少
14:30
To make further progress we really need to look at the orbits
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为了进一步的研究 我们必须要观测运行轨道
14:32
of stars that are much further away.
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那些更远星体的运行轨道
14:34
To do that we'll probably need much more
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为了做到一点我们将会需要
14:36
sophisticated technology than we have today.
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更成熟的技术
14:38
Because, in truth, while I said we're correcting
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因为事实上 当我说到我们正在针对地球大气层进行调节时
14:40
for the Earth's atmosphere, we actually only
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我们仅仅
14:42
correct for half the errors that are introduced.
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更正差不多半数的错误
14:44
We do this by shooting a laser up into the atmosphere,
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我们通过向大气层发射激光来做到这一点
14:47
and what we think we can do is if we
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同时 我们也认为
14:50
shine a few more that we can correct the rest.
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通过这种做法我们可以继续更正剩余的错误
14:52
So this is what we hope to do in the next few years.
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这是我们希望将在接下来几年里完成的人物
14:54
And on a much longer time scale,
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更长的一段时间内
14:56
what we hope to do is build even larger telescopes,
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我们希望建成更大更精确的观测望远镜
14:59
because, remember, bigger is better in astronomy.
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因为在天文学里，大意味着好
15:02
So, we want to build a 30 meter telescope.
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我们希望可以建出一部30米天文望远镜
15:04
And with this telescope we should be able to see
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一旦实现 我们将通过它
15:06
stars that are even closer to the center of the galaxy.
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更好的观测更近距离的星体
15:09
And we hope to be able to test some of
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与此同时我们也可以
15:11
Einstein's theories of general relativity,
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证实爱因斯坦的广义相对论
15:14
some ideas in cosmology about how galaxies form.
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有关星系是如何形成的宇宙学的一些观点。
15:17
So, we think the future of this experiment
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我们认为未来我们将做的实验
15:19
is quite exciting.
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会非常的令人惊奇
15:22
So, in conclusion, I'm going to show you an animation
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作为结论 我将展示一个3D动画
15:24
that basically shows you how these
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呈现
15:26
orbits have been moving, in three dimensions.
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这些轨道是如何移动的
15:29
And I hope, if nothing else,
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我希望，哪怕没有任何别的
15:31
I've convinced you that, one, we do in fact
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我至少成功的说服了你们
15:33
have a supermassive black hole at the center of the galaxy.
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在星系的中心确实有一个巨型黑洞
15:36
And this means that these things do exist in our universe,
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这意味着这些物质的确存在在我们的宇宙中
15:39
and we have to contend with this, we have to explain
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我们必须要承认这一点
15:41
how you can get these objects in our physical world.
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我们需要解释如何可以将那些物质引用到我们的物理世界
15:44
Second, we've been able to look at that interaction
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第二点 巨型黑洞之间
15:47
of how supermassive black holes interact,
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是如何产生影响的
15:50
and understand, maybe, the role in which they play
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如果可能的话 尽可能的理解它们在形成星系的过程中
15:54
in shaping what galaxies are, and how they work.
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所扮演的角色以及这过原理
15:57
And last but not least,
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最后
15:59
none of this would have happened
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如果没有令人震惊的进展
16:01
without the advent of the tremendous progress
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使得科学前沿不断的进步
16:04
that's been made on the technology front.
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这一切的成就都不可能达成
16:06
And we think that this is a field that is moving incredibly fast,
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我们认为这是一个不断快速发展的领域
16:10
and holds a lot in store for the future.
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未来的发展不可限量
16:13
Thanks very much.
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非常感谢
16:15
(Applause)
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(掌声)
ABOUT THE SPEAKER
Andrea Ghez - AstronomerAndrea Ghez is a stargazing detective, tracking the visible and invisible forces lurking in the vastness of interstellar space.
Why you should listen
Seeing the unseen (from 26,000 light-years away) is a specialty of UCLA astronomer Andrea Ghez. From the highest and coldest mountaintop of Hawaii, home of the Keck Observatory telescopes, using bleeding-edge deep-space-scrying technology, Ghez handily confirmed 30 years of suspicions of what lies at the heart of the Milky Way galaxy -- a supermassive black hole, which sends its satellite stars spinning in orbits approaching the speed of light.
Ghez received a MacArthur "genius grant" in 2008 for her work in surmounting the limitations of earthbound telescopes. Early in her career, she developed a technique known as speckle imaging, which combined many short exposures from a telescope into one much-crisper image. Lately she's been using adaptive optics to further sharpen our view from here -- and compile evidence of young stars at the center of the universe.
Andrea Ghez | Speaker | TED.com