科学美国人60秒 天文学家如何最终捕捉到银河系黑洞照片（在线收听）

How Astronomers Finally Captured a Photo of our Own Galaxy's Black Hole

天文学家如何最终捕捉到银河系黑洞照片

Tulika Bose: This is Scientific American's 60-second science. I'm Tulika Bose.

图丽卡·博斯：这是《科学美国人》的60秒科学。我是Tulika Bose。

Today—super massive news from space. The first image of the super massive black hole at the center of the Milky Way, Sagittarius A*, was just released by astronomers this morning.

I'm here talking to Seth Fletcher our Chief Features Editor for Scientific American. He literally wrote a book on the event horizon telescope, and is our resident expert on all things black holes. So Seth, what does it actually take to photograph a black hole?

今天，来自太空的超级大新闻。天文学家今天上午刚刚发布了银河系中心超大质量黑洞人马座A*的第一张图像。

我在这里和《科学美国人》的首席特写编辑塞思·弗莱彻谈话。他真的写了一本关于事件视界望远镜的书，是我们所有黑洞的常驻专家。赛斯，拍摄一个黑洞到底需要什么？

Seth Fletcher: So, I mean, as you know, black holes are technically unseeable. They trap everything that falls inside, including light, anything that passes through the event horizon, which is the boundary, is trapped there forever. It can just never escape.

赛斯·弗莱彻：我的意思是，正如你所知，黑洞在技术上是看不见的。它们会捕获掉在里面的所有东西，包括光，任何通过视界的东西，也就是边界，都会永远被困在那里。它永远逃不掉。

But super massive black holes, like Sagittarius A*, are surrounded by glowing obliterated matter that's orbiting the black hole. Some of it's falling in some of it just forms this disc around it and that stuff glows and the black hole because of the way it warps space, time around it because of the incredible force of gravity, it casts a shadow against that glowing matter.

And so that's actually what we see in this picture.

但像人马座A*这样的超大质量黑洞被环绕黑洞运行的发光的湮没物质所包围。其中一些落在其中一些只是在它周围形成一个圆盘，物质发光，黑洞因为它扭曲空间，时间，因为不可思议的重力，它在发光的物质上投射了一个阴影。

这就是我们在这张照片中看到的。

Bose: So we know that astronomers captured this image with a worldwide network of radio observatories called the Event Horizon Telescope, or the EHT. That's what you wrote book about. Can you tell me a little bit about this?

Bose：所以我们知道天文学家用一个叫做“事件地平线望远镜”或“EHT”的全球射电天文台网络捕捉到了这张图像。这就是你写这本书的内容。你能告诉我一点这方面的情况吗？

Fletcher: People figured out a few decades ago that you could collect a certain wavelength of radio light in microwaves. And if you could do it with a radio telescope, the size of the earth, you would be able to resolve something as small to us as the black hole center, the Milky way, or at least what people thought was there.

弗莱彻：几十年前，人们发现可以在微波中收集特定波长的无线电波。如果你能用一台地球大小的射电望远镜，你将能够分辨出一些对我们来说很小的东西，比如黑洞中心，银河系，或者至少是人们认为存在的东西。

An amazing thing about radio astronomy is that there's a technique called interferometry, that it lets you combine multiple dishes that are very far apart into a single effective virtual telescope.

Bose: It's the biggest high resolution technique in all of astronomy. What does it actually mean, Seth?

射电天文学的一个惊人之处是有一种叫做干涉测量的技术，它可以让你把相距很远的多个碟形天线组合成一个有效的虚拟望远镜。

Bose：这是天文学中最大的高分辨率技术。这到底是什么意思，赛斯？

Fletcher: There's only a very limited period of time each year when telescopes in Europe, North America, South America, Antarctica can all see the same things in the sky. So they put together these elaborate schedule of when Sagittarius A*, for example, is gonna be up over the horizon and visible to what telescopes.

弗莱彻：欧洲、北美、南美和南极洲的望远镜每年只能在非常有限的时间内看到天空中相同的东西。所以他们把这些详细的时间表放在一起，比如说，射手座A*什么时候会出现在地平线上，什么时候可以被望远镜看到。

They just scan black holes for several nights. Then they take all the data in hard drives. Then they physically ship it to two super computer banks, one in Massachusetts, one in Germany, and then they correlate it all into a single data set. And then they search it for common detections where all of its telescopes have seen the same thing.

他们只是扫描了几个晚上的黑洞。然后他们把所有的数据都放在硬盘里。然后，他们将其实际运送到两个超级计算机银行，一个在马萨诸塞州，一个在德国，然后他们将其关联到一个单一的数据集。然后他们在它的所有望远镜都看到了相同的东西的地方寻找共同的探测点。

Bose: And why is this such a big deal?

Bose：为什么这是一件大事？

Fletcher: This is only the second black hole we've ever seen directly, but it's much cooler than that. This is sort of our own private, super massive black hole. This is at the very center of the Milky Way Galaxy.

弗莱彻：这只是我们直接看到的第二个黑洞，但比那个要冷得多。这是我们自己的私人超大质量黑洞。这是在银河系的中心。

It's the solution to a mystery that people have been trying to solve for a really long time. Now that we get to see it, we get to see it change. We get to watch it in the future, and that could make possible all kinds of interesting science about gravity space, time, black holes, galaxy formation, who knows what people are gonna be able to cook up.

这是人们长久以来一直试图解开的谜团的答案。现在我们可以看到它，我们可以看到它的变化。我们可以在将来观察它，这可能会使各种有趣的关于引力空间、时间、黑洞、星系形成的科学成为可能，谁知道人们会编造出什么。

Bose: The astronomers also say that in the future, as they add more observatories to the EHT, they'll even be able to make movies of Sagittarius A*. I guess that would look like videos of matter circling the drain before falling into an abyss.

博斯：天文学家们还表示，未来，随着他们在EHT上增加更多的观测站，他们甚至可以拍摄射手座A*的电影。我猜这看起来像是物质在掉进深渊之前绕着下水道旋转的视频。

For 60-Second Science, I'm Tulika Bose.

《科学60秒》我是图丽卡·博斯。