Andrea Ghez: The hunt for a supermassive black hole

117,171 views ・ 2009-12-03

TED


请双击下面的英文字幕来播放视频。

翻译人员: Haoxiongyi Mei 校对人员: Daisy Yang
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)
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