关于黑洞，你了解多少？在 5500 万光年之外的银河系中央有一个超级大质量的黑洞，达七十亿个太阳质量。这是有史以来第一次，我们能看见它了。天体物理学家谢普 · 多勒曼是事相面望远镜合作案的领导人，他与 TED的克里斯 · 安德森畅谈这张前所未见的代表性黑洞影像，
也谈到捕捉这个影像的背后涉及多少全世界的努力。
演讲者：谢普 · 多勒曼
演讲题目: 创造历史的黑洞图像
Shep, thank you so much for coming. I think your plane landed literally two hours ago in Vancouver.
克里斯·谢普，感谢你的到来。我听说你乘坐的航班两个小时前刚到达温哥华。
Such a treat to have you. So, talk us through how do you get from Einstein s equation to a black hole?
非常高兴今天你能来这里。那么，给我们讲讲你是如何从爱因斯坦方程式中提取黑洞信息的？
Over 100 years ago, Einstein came up with this geometric theory of gravity which deforms space-time.
100多年前，爱因斯坦提出了引力的几何理论，这个理论改变了时空。
So, matter deforms space-time, and then space-time tells matter in turn how to move around it.
所以，物质改变了时空，而时空反过来规定了物质的运行规律。
And you can get enough matter into a small enough region that it punctures space-time,
你可以将足够多的物质聚集到一个非常小的空间里撞击时空，
and that even light can t escape, the force of gravity keeps even light inside.
And so, before that, the reason the Earth moves around the Sun is not because the Sun is pulling the Earth as we think,
but it s literally changed the shape of space so that we just sort of fall around the Sun.
在那之前，地球之所以围绕太阳公转的理由并不是我们以为的太阳吸引着地球，
而是字面意义上的太阳改变了宇宙的形状，所以地球可以说是正在向太阳靠近并公转。
Exactly, the geometry of space-time tells the Earth how to move around the Sun.
没错，时空的几何结构规定了地球围绕太阳公转的轨道。
You re almost seeing a black hole puncture through space-time,
and when it goes so deeply in, then there s a point at which light orbits the black hole.
你几乎能看到一个黑洞穿过时空，
当它进入很深的时候，在某个时刻光就会围绕黑洞运转。
And so that s, I guess, is what s happening here. This is not an image,
this is a computer simulation of what we always thought, like, the event horizon around the black hole.
我猜这就是现在我们所看到的景象。这不是一张照片，
这是电脑模拟下我们所想象的在黑洞周围的事件视界。
Until last week, we had no idea what a black hole really looked like.
The best we could do were simulations like this in supercomputers,
but even here you see this ring of light, which is the orbit of photons.
我们所能做的就是用超级电脑构建类似的模拟场景，
但即使是现在，你看到的这个光圈，其实是光子的运行轨道。
That s where photons literally move around the black hole,
and around that is this hot gas that s drawn to the black hole, and it s hot because of friction.
它展现了光子围绕黑洞的运行轨道，
在它的周围是高热气体，被拉近黑洞，它们之所以很热是因为摩擦。
All this gas is trying to get into a very small volume, so it heats up.
A few years ago, you embarked on this mission to try and actually image one of these things.
几年前，你接受这项任务来尝试并且、构想出这些东西的样子。
And I guess you took -- you focused on this galaxy way out there. Tell us about this galaxy.
我猜——你一直在研究宇宙中的这个星系。给我们介绍一下这个星系吧。
This is the galaxy -- we re going to zoom into the galaxy M87, it s 55 million light-years away.
这就是我研究的星系。我们现在要放大M87星系，它距离我们5500万光年。
Fifty-five million. Which is a long way. And at its heart, there s a six-and-a-half-billion- solar-mass black hole.
5500万。距离非常远。在这个星系的中心，有一个相当于65亿倍太阳质量的黑洞。
That s hard for us to really fathom, right? Six and a half billion suns compressed into a single point.
对于我们而言很难准确测量其质量，对吧？65亿倍太阳质量的物质压缩在这一点。
And it s governing some of the energetics of the center of this galaxy.
But even though that thing is so huge, because it s so far away, to actually dream of getting an image of it,
that s incredibly hard. The resolution would be incredible that you need.
虽然它这么大，但因为它距离地球很远，要想拍摄到它的照片，
这非常困难。分辨率要求之高令人难以想象。
Black holes are the smallest objects in the known universe. But they have these outsize effects on whole galaxies.
黑洞是宇宙中已知的最小的物质。但它们对于星系整体而言有着巨大的影响。
But to see one, you would need to build a telescope as large as the Earth,
because the black hole that we re looking at gives off copious radio waves.
想要看到它，你需要一个像地球那么大的望远镜，
因为我们正在观察的这个黑洞会发出大量的无线电波。
It s emitting all the time. And that s exactly what you did.
Exactly. What you re seeing here is we used telescopes all around the world, we synchronized them perfectly with atomic clocks,
so they received the light waves from this black hole, and then we stitched all of that data together to make an image.
没错。你现在所看到的是我们部署在全球的望远镜，我们让它们与原子钟完美同步，
让它们接收黑洞发出的光波，然后我们将所有数据拼接在一起组成黑洞的照片。
To do that the weather had to be right in all of those locations at the same time, so you could actually get a clear view.
为了达成这个目标，所有望远镜所在地的天气状况都必须达到一定条件，这样你们才能有清晰的视角。
We had to get lucky in a lot of different ways. And sometimes, it s better to be lucky than good.
在很多方面我们都需要幸运的眷顾。有时，运气比正确操作更重要。
In this case, we were both, I like to think. But light had to come from the black hole.
我认为这一次，我们不但操作正确，运气也很好。但我们需要接收来自黑洞的光线。
It had to come through intergalactic space, through the Earth s atmosphere, where water vapor can absorb it,
and everything worked out perfectly, the size of the Earth at that wavelength of light, one millimeter wavelength,
它必须穿过星际空间。穿过地球的大气层，中途还有可能被水蒸气吸收，
但一切都非常完美。地球的大小，在波长一毫米的光线下，
was just right to resolve that black hole, 55 million light-years away. The universe was telling us what to do.
正好能够展现5500万光年外那个黑洞的样子。宇宙正在告诉我们应该做什么。
So you started capturing huge amounts of data. I think this is like half the data from just one telescope.
所以你们开始收集海量的数据。这些只是其中一台望远镜所收集的数据的一半？
Yeah, this is one of the members of our team, Lindy Blackburn,
and he s sitting with half the data recorded at the Large Millimeter Telescope, which is atop a 15,000-foot mountain in Mexico.
是的，这是我们小组的一员，林迪·布莱克本，
在他旁边的是大型毫米波望远镜记录下的一半的数据，这架望远镜位于墨西哥一座近5000米高的山上。
And what he s holding there is about half a petabyte.
Which, to put it in terms that we might understand, it s about 5,000 people s lifetime selfie budget.
用易于想象的东西来比喻的话，大约能存放5千人一辈子的自拍照。
It s a lot of data. So this was all shipped, you couldn t send this over the internet.
数据非常多。所以只能通过线下运输，你们没办法在互联网上传输。
All this data was shipped to one place and the massive computer effort began to try and analyze it.
所有的数据都被运送到一个地方，然后计算机开始解析这些数据。
And you didn t really know what you were going to see coming out of this.
The way this technique works that we used --
imagine taking an optical mirror and smashing it and putting all the shards in different places.
我们是这么工作的。
想象打碎一面镜子，然后把所有的碎片四散开来。
The way a normal mirror works is the light rays bounce off the surface,
which is perfect, and they focus in a certain point at the same time.
普通镜子的工作原理是通过镜面反射，
所有的光在同时聚焦在某个特定的点。
We take all these recordings, and with atomic clock precision we align them perfectly, later in a supercomputer.
我们有了所有的数据，在原子钟精度的帮助下，我们将这些数据准确输入超级计算机。
And we recreate kind of an Earth-sized lens. And the only way to do that is to bring the data back by plane.
然后我们重构了一个地球大小的透镜。只能通过飞机运送数据。
You can t beat the bandwidth of a 747 filled with hard discs.
没有哪个网络比一架满载硬盘的波音747飞机更快的了。
And so, I guess a few weeks or a few months ago, on a computer screen somewhere, this started to come into view. This moment.
那么我猜，在几周或几个月前，在某地一台电脑的显示器上，黑洞的形象在那一刻渐渐成形。
Well, it took a long time. I mean, look at this. That was it. That was the first image.
嗯，这花了好一会儿工夫。看看这张照片。这就是黑洞。这就是黑洞的第一张照片。
So tell us what we re really looking at there. I still love it.
给我们介绍一下这张照片吧。我依然非常喜欢这张照片。
So what you re seeing is that last orbit of photons. You re seeing Einstein s geometry laid bare.
现在你所看到的是光子最后一次运动的轨迹。爱因斯坦的几何学说彻底展现在你们眼前。
The puncture in space-time is so deep that light moves around in orbit, so that light behind the black hole,
as I think we ll see soon, moves around and comes to us on these parallel lines at exactly that orbit.
这次对时空的撞击之深，使得光子在轨道上绕圈，这样黑洞身后的光，
我觉得我们马上就可以看到它了，就会绕圈，并且在这个轨道上的平行光线马上就会来到我们这里。
It turns out, that orbit is the square root of 27 times just a handful of fundamental constants. It s extraordinary when you think about it.
事实上，这个轨道是27的平方根，与一些基本常数相乘。如果你认真思考，就会发现它非常奇妙。
When ... In my head, initially, when I thought of black holes, I m thinking that is the event horizon,
there s lots of matter and light whirling around in that shape. But it s actually more complicated than that.
当……在我脑海里，我最初认为黑洞就是一个事件视界，
有许多物质和光线围绕着它转。但事实远比我想象的要复杂。
Well, talk us through this animation, because it s light being lensed around it.
给我们解释一下这个动画，它展现了光正在透过这个黑洞。
You ll see here that some light from behind it gets lensed, and some light does a loop-the-loop around the entire orbit of the black hole.
你现在看到的是在黑洞后面的一些光透过它，有些光的确会一直绕着黑洞转。
But when you get enough light from all this hot gas swirling around the black hole,
then you wind up seeing all of these light rays come together on this screen, which is a stand-in for where you and I are.
但如果光足够多，它们来自黑洞周围的高温气体中，
那么最终你将看到这些光线以屏幕上所呈现的方式聚集在一起，就像你和我现在站在台上一样。
And you see the definition of this ring begin to come into shape. And that s what Einstein predicted over 100 years ago.
然后你会发现这个环逐渐成型。这就是爱因斯坦在百年前所预测的事情。
Yeah, that is amazing. So tell us more about what we re actually looking at here. First of all, why is part of it brighter than the rest?
这真是令人吃惊。现在，能不能再解释一下这张图片？首先，为什么有些地方比其他地方更亮呢？
So what s happening is that the black hole is spinning. And you wind up with some of the gas moving towards us below and receding from us on the top.
事实上这个黑洞正在旋转。最终靠近地球的气体运动到了下方，而远离地球的气体运动到了上方。
And just as the train whistle has a higher pitch when it s coming towards you, there s more energy from the gas coming towards us than going away from us.
正如火车的鸣笛，当它靠近你的时候，音高会增高，比起远离地球的气体，靠近的气体蕴含很多能量。
You see the bottom part brighter because the light is actually being boosted in our direction.
你可以看到下方更亮一点是因为下方光线正加速向我们靠近。
And how physically big is that? Our entire solar system would fit well within that dark region.
And if I may, that dark region is the signature of the event horizon.
并且，我想打断你一下，这个黑暗区域标志了事件视界。
The reason we don t see light from there, is that the light that would come to us from that place was swallowed by the event horizon.
我们之所以无法看到里面的光，是因为这里面朝地球靠近的光已经被事件视界吞噬了。
So that -- that s it. And so when we think of a black hole, you think of these huge rays jetting out of it,
which are pointed directly in our direction. Why don t we see them?
这就是黑洞。所以，当我们谈起黑洞的时候，你想说的是它向外发射的射线，
它们朝我们而来。为什么我们看不见他们呢？
This is a very powerful black hole. Not by universal standards, it s still powerful,
and from the north and south poles of this black hole we think that jets are coming.
这是一个强有力的黑洞。虽然不是公认的，但它依然非常强大，
在这个黑洞的北极和南极，我们认为射线正从这两段过来。
Now, we re too close to really see all the jet structure, but it s the base of those jets that are illuminating the space-time,
and that s what s being bent around the black hole.
我们距离太近，所以无法看到这些射线的结构，但这些射线能够展示时空的样子，
同时也能展现在黑洞周围空间扭曲的状况。
And if you were in a spaceship whirling around that thing somehow, how long would it take to actually go around it?
如果某天你在一架太空飞船上，正在绕这这个东西飞行，绕场一周需要多久呢？
First, I would give anything to be in that spaceship.
Sign me up. There s something called the … if I can get wonky for one moment … the innermost stable circular orbit,
that s the innermost orbit at which matter can move around a black hole before it spirals in.
帮我抢一个位置。让我想一下，有一个东西叫做最内侧稳定圆形轨道，
这是轨道最内侧，物质在这个轨道上绕着黑洞运行，之后它们会旋转入黑洞。
And for this black hole, it s going to be between three days and about a month.
对于这个黑洞而言，这个过程大约会持续三天到一个月。
It s so powerful, it s weirdly slow at one level. I mean, you wouldn t even notice falling into that event horizon if you were there.
它的力量这么强大，我甚至觉得这个过程有点慢。我的意思是，如果你在场，你甚至不会注意到自己进入这个事件视界。
So you may have heard of "spaghettification," where you fall into a black hole and the
gravitational field on your feet is much stronger than on your head, so you re ripped apart.
你可能听说过一个词叫“面条化”，当你掉入一个黑洞的时候，
你的脚所受的引力场远大于你的头所受的引力场，所以你就会被拉扯破碎。
This black hole is so big that you re not going to become a spaghetti noodle.
You re just going to drift right through that event horizon. So, it s like a giant tornado.
你会直接掉入那个事件视界。这就像一个巨大的龙卷风。
When Dorothy was whipped by a tornado, she ended up in Oz. Where do you end up if you fall into a black hole? Vancouver. Oh, my God.
当桃乐丝被卷入龙卷风的时候，她最后到了奥兹国。如果你掉入黑洞，最后你会到哪儿？温哥华。天呐。
It s the red circle, that s terrifying. No, really. Black holes really are the central mystery of our age,
because that s where the quantum world and the gravitational world come together. What s inside is a singularity.
这个红色的圈太吓人了。你在开玩笑。黑洞可谓是我们这个时代的中心之谜，
因为它是量子世界与引力世界的交合点。黑洞的中心是一个奇点。
And that s where all the forces become unified, because gravity finally is strong enough to compete with all the other forces.
在这里所有的力都会趋于统一，因为引力是如此之大，其他力无法与之抗衡。
But it s hidden from us, the universe has cloaked it in the ultimate invisibility cloak. So we don t know what happens in there.
但它隐藏了起来，宇宙用终极隐形斗篷把它遮掩了起来。所以我们不知道在那里面究竟发生了什么。
So there s a smaller one of these in our own galaxy. Can we go back to our own beautiful galaxy?
所以在我们的星系中有一个较小的黑洞。可以回到我们自己美丽的星系吗？
This is the Milky Way, this is home. And somewhere in the middle of that there s another one, which you re trying to find as well.
这是银河，是我们的家。而在银河的某个地方，存在着另外一个黑洞，你正在努力把它找出来。
We already know it s there, and we ve already taken data on it. And we re working on those data right now,
我们已经发现了它的存在，也已经采集到了它的数据。我们现在就在研究这些数据，
so we hope to have something in the near future, I can t say when.
希望在将来能够研究出结果，虽然我不敢对时间打包票。
It s way closer but also a lot smaller, maybe the similar kind of size to what we saw? Right.
这个黑洞距离较近，但体积较小，也许和我们现在看到的这个差不多大？是的。
So it turns out that the black hole in M87, that we saw before, is six and a half billion solar masses.
事实证明M87星系中的黑洞，就是我们之前看到的那个，重达65亿太阳的质量。
But it s so far away that it appears a certain size.
The black hole in the center of our galaxy is a thousand times less massive, but also a thousand times closer. So it looks the same angular size on the sky.
我们星系里的这个黑洞比它小一千倍，但也比它近一千倍。所以它们两个在空中看起来差不多大小。
Finally, I guess, a nod to a remarkable group of people. Who are these guys?
最后，我猜，我们要认识一下一群了不起的人。他们是谁？
So these are only some of the team. We marveled at the resonance that this image has had.
这些仅是我们小组的部分成员。我们惊叹于这张照片所引起的反响。
