489：黑洞研究新进展

播客第489期，黑洞专题更新。

Cast episode four eighty nine, black holes update.

欢迎收听天文播客，这是我们每周以事实为基础的宇宙之旅，不仅帮助您了解已知的宇宙奥秘，更揭示这些知识背后的探索过程。

Welcome to astronomy cast, our weekly facts based journey through the cosmos where we help you understand not only what we know, but how we know what we know.

我是弗雷泽·凯恩。

My name is Fraser Cain.

我是《今日宇宙》的出版人。

I'm the publisher of Universe Today.

和往常一样，与我一起的是帕梅拉·盖博士，她是太平洋天文学会技术与公民科学部门主任，同时也是CosmoQuest项目的负责人。

With me as always, doctor Pamela Gay, the director of technology and Citizen Science of the Astronomical Society of the Pacific and the Director of CosmoQuest.

嗨，帕梅拉，最近怎么样？

Hey, Pamela, how you doing?

我很好。

I'm doing well.

你呢，弗雷泽？

How are you doing, Fraser?

很好。

Great.

刚提到节目开始前，天气突然变了。

Just mentioning the pre show, the weather has just turned.

我的郁金香种得可好了。

My tulip game is strong.

昨天差不多有26度。

It's like 26 degrees yesterday.

感觉全世界的快乐都回来了。

It just feels like all the happiness has returned to the world.

我们这边还在24、25度左右，但外面的花开得特别美。

We're still down around 24, 25, but there is the most amazing flowers out there.

我准备把照片发到Instagram上。

I'm gonna be posting pictures on Instagram.

记得关注，我可能真要提升Flickr的使用频率了，因为需要找个地方存我拍的所有照片。

So stay tuned, and I may actually up my Flickr game because I need some place to store all the photos I've been taking.

嗯，你知道Flickr被收购了吧。

Well, Flickr's been bought, you know.

我知道。

I know.

我知道。

I know.

现在是Smug Mug接手了，不过

It's now smug mug, but

但Flickr创始人斯图尔特·巴特菲尔德在推特上发文表示他赞同这次收购。

But Stuart Butterfield, founder of Flickr, posted on Twitter that he approved of the purchase.

所以我觉得，很多天文摄影师仍然把Flickr作为存储照片的最佳平台之一。

So I think, you know, a lot of astrophotographers still use Flickr as sort of one of the best places to be able to store your photos.

而且现在看来他们由靠谱的团队接手了，不像之前在雅虎旗下那样放任自流。

And it looks like they're under some good hands now as opposed to a drift under the Yahoo mantle.

所以我认为这是个明智之举。

So I think it's a good move.

那就继续吧。

So go ahead.

我允许你发布你的照片。

I permit you to post your pictures.

不管有没有你的许可我都会这么做，不过还是感谢你。

I shall do this with or without your permission, but I appreciate it anyways.

我猜你会的。

I figured you might.

好吧。

Alright.

又到了更新节目的时间。

Another update episode.

这次我们来看看黑洞研究领域的新发现和变化。

This time we look at what's new and changed in the research of black holes.

正是在这里，我们发现了该领域许多重大的新发现。

And it's here that we find a lot of substantial new discoveries in the field.

自从我们首次报道黑洞以来，已经发现了如此多的新事物。

So much has been discovered since we first covered black holes.

准备好了吗？

Ready for this?

十年前。

A decade ago.

更多。

More.

已经超过十年了。

It's been more than a decade.

因为那又是最早的内容之一，对吧？

Because it was like one of the first again, right?

当我们开始制作天文播客时，我们首先处理了所有容易的话题。

When we started up astronomy cast, we went after all the low hanging fruit.

所以我们最初的几期节目都是关于系外行星之类的。

So our first episodes are like extrasolar planets.

为什么冥王星不是行星了？

Why isn't Pluto a planet?

黑洞、暗物质、暗能量。

Black holes, dark matter, dark energy.

我们已经做了489期节目，是时候重新审视黑洞这个话题了。

Here we are 489 episodes into the show, and it's time to come back around and take another look at black holes.

所有我曾热情洋溢地认为是真理的事情，现在都被证明不是了。

All the things I enthusiastically said were true that we now know aren't.

我想听听你曾经怀疑但实际正确的事情。

I wanna get to the things that you were skeptical about that actually are.

这样我们就能看到问题的两面了。

So we're gonna be able to see both sides of this.

不过请继续说吧。

But please proceed.

你想从哪里开始讲黑洞的新发现？我们甚至需要先解释什么是黑洞吗？

Where would you like to start on what's new about black do we have to even say what a black hole is?

你觉得我们能直接跳过那部分吗？

Do you think we can just skip right past that part?

我们可能还是需要解释一下，毕竟时不时会有新听众加入。

We probably need to explain it because we do have new listeners now and then.

好吧。

Okay.

简单说一下。

Briefly.

对。

Yeah.

什么是

What is a

什么是黑洞？

what's a black hole?

黑洞是指任何将大量质量压缩到极小的体积内，使得当你足够接近它时，逃逸速度会超过光速的天体。

A black hole is any object that has smushed so much mass into such a small volume that you can get close enough to it that your escape velocity exceeds the speed of light.

所以地球就是个人洞。

So the Earth is a personhole.

我无法从地球表面跳起来逃离我们的星球。

I can't jump up and escape our planet from the surface of the planet.

现在，如果你把我放在地表上方几千英里处，假设我能从一个不存在的表面跳下来，我就能逃脱，地球就不再是人洞了。

Now, if you like stuck me a couple thousand miles above the surface and somehow I was able to like jump off of a nonexistent surface up there, I could escape and the Earth would no longer be a human hole.

这听起来不太对劲。

That sounded wrong.

我们继续往下讲。

We're gonna move on.

典型的恐慌反应。

Classic panic.

但对于黑洞，如果你把我们的太阳压缩到三厘米大小并试图站在它的表面，首先你会被压死。

But with a black hole, if you took our sun and you squished it down to three centimeters and attempted to stand on its surface, you would first of all be squished to death.

其次，即使你是光子也无法逃脱，因为半径三厘米的太阳已经变成了黑洞。

And second of all, you could not jump off even if you were a photon of light because the sun would have become a black hole at three centimeters in radius.

对。

Right.

所以这仅仅意味着逃逸速度超过了光速。

So all it means is escape velocity greater than the speed of light.

没错。

Right.

实际上，到了那个程度，任何速度都无法让你逃离黑洞。

And actually, at that point, no velocity will take you away from a black hole.

即使你能超光速飞行，所有路径都会通向奇点。

Even if you could go faster than the speed of light, all roads lead into the singularity.

但你不可能超光速。

But you can't go faster than the speed of light.

当然不行。

Of course not.

是啊。

Yeah.

即便你能做到，那也无济于事。

And even if you could, it wouldn't help you.

所以没错，你无法超越光速。

So but yes, you can't go faster than the speed of light.

或许对你有帮助呢。

It might help you.

但人们总是把黑洞想象成...你看，这名字本身就起得很糟糕。

But people always sort of imagine black holes as these as, you know, the name is terrible.

对吧？

Right?

是啊。

Yeah.

因为它就像个洞。

Because it's like whole.

甚至当他们展示黑洞模拟影像时，你看到这种弯曲时空向奇点坠落的画面，大脑就会想：哦，这就像个你可以跳进去的东西，然后可能会出现在...我不知道，某种能让你看到整个人生并随意沟通的图书馆里，不过我不打算...

And even when they show these simulations of what a black hole looks like and you see this sort of curved space time going down to the singularity, your brain thinks, oh, it's like a thing that you could jump into and then you would emerge in, I don't know, some kind of library that would allow you to see your whole lifetime and communicate with anyway, I'm not gonna

那部电影在那部分之前我都很喜欢。

I loved that movie up until that part.

然后我就怒了。

Then I raged.

那部分就是基普·索恩直接表示'我受够这部电影了'的地方。

That's the part where Kip Thorne just sort of went, I am done with this movie.

是啊。

Yeah.

差不多是这样。

Something like that.

所以在太阳系中，如果我们突然通过某种外星手段将太阳压缩到半径仅三厘米并保持这个大小，虽然它不再以对地球植物和人类有用的方式发光，但我们的行星仍会保持现在的轨道运行，因为轨道取决于天体质量而非大小——只要你在其表面之外。

So in our solar system, were we to suddenly squish the sun via alien means that we do not have down to only being three centimeters in radius and somehow keeping it that size, then while it would no longer be emitting light in a way that is as useful for plants and humanity on our world, Our planet would just keep on orbiting the way it's orbiting right now because orbits depend on the mass of the object, not the size of the object as long as you're above their surface.

所以黑洞并不会四处吞噬东西。

So black holes don't go around eating things.

这根本不是它们会做的事。

That's just not a thing they do.

它们只会等待物体自己撞上来。

They wait for things to stumble into them.

它们就像是宇宙中的鳄鱼。

They're kind of the alligators of the cosmos.

是啊。

Yeah.

人们总是问，比如，银河系中心的黑洞什么时候会吞噬掉银河系里的一切？

And people always ask, like, you know, when is the black hole in the middle of the Milky Way going to gobble up everything in the Milky Way?

答案是它不会。

And the answer is it's not going to.

不会。

No.

永远不会。

Ever.

不会。

No.

就像你说的，如果用同等质量的黑洞替代太阳系中的太阳，行星们仍会愉快地围绕它运行数十亿年，一切都不会有问题。

And if you, you know, and as you said, you replace the Sun in the Solar System with a black hole of the same mass, and the planets will gladly orbit around it for billions of years and everything will be fine.

没问题。

No problem.

只是会变得非常寒冷。

It'll be very cold.

确实会有些问题。

There will be problems.

仅仅是寒冷而已。

It'll just be cold.

对。

Yeah.

没错。

Yeah.

因为黑洞根本当不了合格的恒星。

Because black holes make terrible stars.

挺好的。

So fine.

黑洞有几种不同的类型，几种不同的‘风味’。

And there are a couple of varieties of black holes, a couple of flavors.

是的。

Yes.

所以我们总是想象存在一个友好的连续谱：一端是确实存在的恒星质量黑洞。

So we always kind of imagine that there'd be this nice friendly continuum where you have the stellar mass black holes, which do exist.

它们确实存在。

They do exist.

这些黑洞形成于日常超大质量恒星——无论是天生如此还是吞噬了伴星（具体原因不重要）——当它决定爆发超新星，并留下如此多的质量以至于中子星无法形成，因为中子间的斥力无法将它们充分分开。

These are what happens when your everyday overly large star that was either born that way or ate its companion, we don't care which, decides to go supernova and leave behind so much mass that a neutron star cannot form because the neutrons cannot push each other far enough apart.

所以我们从一颗普通的30倍太阳质量恒星开始，它经历一定质量损失后，最终以黑洞形式结束生命。

So we start with your everyday 30 mass star that undergoes a certain amount of mass loss and by the end of its life dies as a black hole.

或者你拿一颗白矮星中子星，让它彻底吞噬伴星——通过合并等各种方式。

Or you take a white dwarf neutron star and you radically eat its companion, mergers, all these different things.

无论通过哪种方式，你都能形成一颗恒星质量黑洞。

However you do it, you can form a stellar mass black hole.

就我们所知，这些黑洞的质量可达太阳的数十倍，甚至可能达到太阳质量的100倍左右。

And as far as we know, these things go up to tens of times the mass of the Sun, maybe a 100 or so times the mass of the Sun.

这些家伙确实存在。

These suckers are found.

然后我们还发现了——这就是我上次做这期节目时大错特错的地方。

Then we have also identified, and this is where I was so wrong the last time we did this episode.

我们已经发现，部分（但并非全部）星系的中心存在超大质量黑洞，其质量可达太阳的数十万倍。

We have identified that some, but not all galaxies, have in their core supermassive black holes that start to get to be, like, tens of thousands of times the mass of the Sun.

数十亿倍。

Billions.

没错。

Yeah.

其确切质量与恒星构成的中央凸起球体大小直接相关。

The exact mass is directly proportional to how big the bulgy center spheroid of stars is.

所以在我们的银河系中，如果从侧面看，中心有一个巨大的球状体。

So in our own Milky Way, if you look at it from the side, it has this large spheroid in the center.

这个球状体与其中恒星的运行速度相关，也与中心超大质量黑洞的大小相关。

That spheroid is related to the velocity of the stars in that spheroid and it is also related to the size of the supermassive black hole in the center.

而我们不知道哪个先出现——是恒星速度、球状体，还是黑洞。

And we do not know which came first, the velocity, the spheroid, or the black hole.

它们很可能是在大致相同的时间通过混沌过程形成的。

And they probably formed via chaotic processes at about the same time.

嘿，大家好。

Hey, everyone.

我是弗雷泽。

Fraser here.

本周我们的天文播客有了新赞助商，就是Mack Weldon。

We got a new sponsor for astronomy cast this week, and that's Mack Weldon.

你可能知道，Mack Weldon生产各种男士基础款服装，比如袜子、内裤和T恤。

And if you are aware, Mack Weldon makes a bunch of men's basics clothing, like socks and underwear and T shirts.

所以我有机会试用了他们的一些产品。

And so I got a chance to try out a bunch of their stuff.

我买了几条内裤、几双袜子和一件他们的衬衫。

I got a couple of pairs of underwear, couple of pairs of socks, and one of their shirts.

我已经初步体验了这些产品。

And I've had a chance to sort of put it through the beginning paces.

希望以后还能继续更新使用感受。

I mean, I'm hopefully, I'll get, you know, another update down the road.

但到目前为止，我对这些衣物非常满意。

But so far, I'm really happy with the clothing.

袜子穿起来非常舒适。

The socks are very comfortable.

它们非常合脚。

They fit really well.

质地轻盈，透气性很好。

They're very light, very breathable.

内裤和T恤也是一样的好。

And same thing with the underwear and the T shirt.

如果你能访问他们的网站macweldon.com，他们会给你首单20%的折扣，结账时只需输入促销码astro即可。

If you can go to their website, macweldon.com, they want to give you 20% off your first order, Just enter the promo code astro at checkout.

我会把这些衣服带去健身房，还会穿着它们进行长距离步行。

And I'm going to be taking this to the gym, I'm going to be going on big long walks.

我真的很期待能全面测试这些衣服的性能，天啊，没想到我居然会对袜子这么着迷。

And I'm really looking forward to kind of putting this clothing through its paces, man, I can't believe I'm nerding out about socks.

总之，谢谢Mac Weldon。

Anyway, thanks, Mac Weldon.

请访问macweldon.com。

Go to macweldon.com.

首单可享20%优惠。

20% off your first order.

结账时输入促销码ASTRO即可享受20%折扣。

Enter the promo code ASTRO at checkout for that 20% off.

好的。

Okay.

太好了。

Great.

现在大家都跟上进度了。

So now everyone's caught up.

接下来我们要进入'我们知道哪些新发现'的部分。

And then now we're gonna move into the what do we know that's new.

其中很多内容也包括对其他类型黑洞的探索。

And a lot of this is the search for other kinds of black holes as well.

对吧？

Right?

然后意识到，哦，见鬼。

And the realization of, oh, expletive.

事实证明，并非所有大型星系的中心都有黑洞。

It turns out not all large galaxies actually have black holes in the center.

等等

Wait.

那么你哪里错了？

So how were you wrong?

你之前说过它们确实有黑洞吗？

Had you said that they did have them?

十年前我们录制上一期节目时，我们认为所有大型星系——甚至可能所有星系（虽然矮椭球星系让我们困惑）——所有大型星系中心都存在超大质量黑洞。

We thought when we recorded the last one of these episodes a decade ago, we thought that all large galaxies and maybe even all galaxies, although the dwarfseroidals were baffling us, All large galaxies had supermassive black holes in the center.

这是我们当时的认知。

This is what we thought.

我们错了。

We were wrong.

事实证明，那些没有凸起的超级扁平螺旋星系——没有球状体的那些——并不存在黑洞。

It turns out that the superflats spirally ones that do not have a bulge, do not have the spheroid.

像M101（风车星系）这样的扁平星系，其中心似乎完全不存在黑洞。

The flat ones like m one zero one, the pinwheel galaxy, appear to have absolutely no black hole in their center.

那么它们去哪儿了？

So where do they go?

嗯，我想问题在于，我们是否知道为什么有些星系中央似乎没有超大质量黑洞？

Well, I guess the question is, do we know why there are galaxies that don't seem to have a supermassive black hole in the middle of them?

它们似乎找到了以更少混乱方式形成的方法。

They seem to have figured out how to form in a much less chaotic way.

这意味着，如果按照常规的星系层级形成方式——将几个小星系以特定方式碰撞合并成更大星系，再不断重复这个过程——我们猜测，如果操作得当（虽然还不确定），可能会缓慢而谨慎地形成一个完全没有中央隆起、没有超大质量黑洞的完美扁平星系。

This means that if the normal hierarchical way of forming galaxies where you take a couple baby galaxies and you throw them at each other just right and they become a bigger galaxy and then you throw in a few more baby galaxies and you end up with a bigger galaxy, It appears that if you do this just right, maybe, we're not sure this is what we're guessing, you can end up slowly and carefully building a perfectly flat galaxy that doesn't have a bulge, doesn't have a supermassive black hole in the center.

另外还有可能是它们与其他星系碰撞后，黑洞被踢出去了。

And the other thing is that they can have collisions with other galaxies and the black holes can get kicked out.

确实如此。

That's true.

但如果它们曾与其他星系碰撞，我们就不该看到现在观测到的这种惊人结构。

But if they'd had collisions with other galaxies, we wouldn't expect to see the amazing structure that we're seeing.

比如M101风车星系，它就是个拥有极其开阔、形态完美的旋臂的宏伟螺旋星系。

So m one zero one for instance, the Pinwheel Galaxy is this grand design spiral with extraordinarily open, well formed arms.

它正在进行大规模的恒星形成活动。

It has extensive amounts of star formation going on.

这是一个尘埃系统，你通常不会看到这种既没有中央隆起、又没有扭曲的宏伟螺旋结构——当然，我们不在其平面内，无法观测是否存在扭曲。

This is a dusty system that you wouldn't expect to see this kind of grand design spiral without any bulge, without any warp to the Well, we aren't in a plane to be able to see if there's a warp.

如果过去发生过剧烈碰撞，你不可能看到这种结构。

You wouldn't expect to see this kind of structure if there have been significant collisions in the past.

你应该会看到某种膨胀现象。

You'd expect to see some sort of a puffing out.

我们自己的银河系存在所谓厚盘结构，部分原因就是碰撞带来的额外速度和能量使星系盘膨胀。

Our own Milky Way Galaxy, part of the reason we have this what we call a thick disc, this thickness to the disc of our galaxy is from collisions that have added velocities, added energy that puffed up the disc.

那么对我们之前节目的勘误更新：大多数星系中心都存在超大质量黑洞。

So I guess errata updates to our previous show, most galaxies have supermassive black holes in the heart of them.

大多数大型星系——就目前所知，所有具有球体结构的星系——中心都存在大质量至超大质量黑洞。

Most large galaxies, and as far as we know, all galaxies that have a spheroid structure have massive to supermassive black holes in their centers.

好的。

Okay.

好的。

Alright.

还有什么新发现吗？

What else is new?

当我开始谈论黑洞时，我说过我们有恒星质量黑洞和超大质量黑洞。

So when I start talking about black holes, I said we have stellar mass, and I said we have supermassive black holes.

但在大约100倍太阳质量到数万至数百万倍太阳质量之间，存在着一整个质量范围。

But there's this whole range of masses between a 100 ish solar masses and tens of thousands to millions of solar masses.

在这个100到100万倍太阳质量范围内，就是我们所说的中等质量黑洞。

And in that 100 to 1,000,000 solar mass range, this is what we call intermediate mass black holes.

它们很难被发现。

They are hard to find.

是的。

Yeah.

但我们正在逐渐找到它们。

But we're starting to find them.

但这甚至相当间接。

But it's even fairly indirectly.

对吧？

Right?

比如，他们一直在寻找这些中等质量黑洞的地方是在——天啊，你们把我的脑子搞糊涂了。

Like, the place that they've been looking for these intermediate mass black holes is in man, you guys have wrecked my brain.

球状星团。

Globular clusters.

来吧，给我们说准确点。

Come on, say it right for us.

球状星团，所以他们现在虽然没有直接观测到，但通过数学方法推断出这些中等质量黑洞必然存在于其中。

Globular clusters, so that they have now, they haven't necessarily seen them directly, but they've teased out mathematically, that these intermediate mass black holes have to be in there.

而且他们开始发现这些黑洞可能存在于非常有趣的地方。

And they're starting to find indications they may exist in really interesting places.

所以看起来它们可能存在于球状星团中。

So it looks like they might exist in globular clusters.

正如你所说，它们似乎可能存在于一些较小质量的婴儿星系中。

As you were saying, it looks like they may exist in some of the smaller mass baby galaxies.

所以当你在外观察时，比如看看螺旋星系NGC 4395，它的中心似乎有一个1万倍太阳质量的黑洞。

So when you're out there looking around, if you look at, for instance, the spiral galaxy NGC forty three ninety five, it looks like it has a 10,000 mass black hole in its center.

这就是为什么我修正了先前的说法，指出在星系中心发现的是大质量而非超大质量黑洞。

So this is where I corrected my earlier statement to say massive but not supermassive are being found in the centers of galaxies.

整个关于球状星团的概念——它们不符合任何分类，是种独特的存在——可能与黑洞的这种球状质量函数存在某种关联，这想法相当惊人。

And this whole idea that globular clusters, which don't really fit anything, they're kind of their own weird creatures, that they could also somehow be related to this spheroid mass function for black holes is kind of awesome.

因此我认为，如果我们回到十年前讨论中等质量黑洞这个话题，当时的证据会比现在少得多。

And so I would say, if we went back and sort of had this conversation about intermediate mass black holes ten years ago, we would have less evidence for them then.

那时既没有观测数据，也没有任何迹象表明它们的存在。

There would have been no observations, no data indicating that they're there.

而现在我们虽然有些微数据表明它们存在，但还没有确凿的观测证据证明它们确实存在

And now we have slight data that they're there, but no real smoking gun observations that they exist

——至少目前还没有。

yet.

没有。

No.

但引力波科学正开始给我们带来诱人的成果。

But the gravitational wave science is starting to give us tantalizing results.

正如我刚才提到的，我认为科学的发展速度远超你当初的预期。

And this is, as I was mentioning, this is where I think the science has proceeded a lot faster than I think you had ever expected that it would.

确实如此。

It's true.

我准备好听你收回前言了。

I'm ready for you to recant.

噢，不。

Oh, no.

我不会收回的。

I'm not recanting.

好吧。

Okay.

好吧。

Alright.

那么最终，总会有你收回观点的时候。

Well, then eventually, there will be a time when you will recant.

我坚持认为LIGO项目前十年获得资金支持为时过早。

I'm gonna maintain that the first ten years of LIGO funding was too early.

好吧。

Alright.

好的。

Okay.

行吧。

Alright.

我当时立场很坚定。

I had strong opinions.

明白了。

Okay.

好的。

Okay.

不过让我们来谈谈黑洞相撞这个令人兴奋的惊人发现吧。

But let's talk about the amazing exciting news of black holes colliding together.

得益于全球引力波探测器网络近期的重大扩展，目前已探测到的部分引力波现象，似乎可以通过中等质量黑洞碰撞来解释。

Some of the gravitational waves that have so far been detected, thanks to the great expansions that have recently occurred to the global network of gravitational wave detectors, they're finding things that look like they can be explained through the collision of intermediate mass black holes.

这可能是原始黑洞存在的确凿证据。

So this could be that smoking gun for perhaps primordial black holes.

这些黑洞基本上形成于宇宙微波背景辐射释放前的那个时期——听起来就像你放出了一群猎犬。

Black holes that formed basically in that period of time between moment zero and the release of the cosmic microwave background, which kind of sounds like you're releasing the hounds.

所以现在我会这样想象光子的释放场景。

So that's now how I'm gonna imagine the photons.

显然，LIGO通过引力波探测，在我们此刻讨论的时间节点已经检测到五次黑洞碰撞事件。

And so, I mean, obviously, LIGO with the gravitational waves, they've I think they've detected five black hole collisions at the time that we're talking about right now.

没错。

Yes.

这些黑洞的质量在几十个太阳质量之间。

The masses of these black holes are in the dozens of solar masses.

我认为最大的在30倍太阳质量左右。

I think the biggest is in the 30 range.

所以这些并非中等质量黑洞，这实际上是LIGO探测能力的局限。

So these are not intermediate mass black holes, and this is really just a limitation of what LIGO can do.

并不是说那些黑洞不存在。

It's not that those black holes aren't out there.

只是LIGO和其他仪器目前还无法探测到它们。

It's just that LIGO and other instruments can't detect them yet.

每当我们发现30倍太阳质量或数十倍太阳质量的黑洞时，人们总想争论这或许能证明它们确实可以形成如此之大。

And people do want to kind of argue every time we start finding black holes through 30 solar masses and these multiple tens that maybe maybe we could start to say that this definitely says that they do form this big.

因此这是关于更大质量黑洞的诱人证据，也是未来探测它们的一种途径。

So this is where it's tantalizing evidence of larger black holes and a way to detect them in the future.

那么30倍太阳质量的黑洞，对于由普通恒星坍缩形成的黑洞来说，这个质量会让人意外吗？

And so is 30 times the mass of the Sun say, is that a surprising mass for a black hole that could come from a regular star collapsing in on itself?

是的。

Yeah.

因为我记得我们之前讨论过超新星，我们确实应该做一期关于超新星的更新节目。

Because I remember way back to our supernova, and we should totally do an update on supernovae.

但当我回想我们那期关于超新星的节目时，最大的那些恒星会完全爆炸。

But when I think about our supernova show that the biggest ones, they just detonate entirely.

没错。

Yes.

只有中等质量范围的恒星才会形成这类黑洞。

It you only get those black holes from this middle range of sizes.

那么30倍太阳质量是否开始突破我们原先认为的可能极限？

So is 30 starting to kind of break what we thought was possible?

是的。

Yeah.

突破的方式在于，我们知道存在像手枪星这样由极其巨量物质形成的超大质量恒星。

And the way it's breaking it is we know that there's these massive stars like the pistol star that form out of large, large, large amounts of material.

但它们随后会经历巨大的质量损失。

But then they undergo huge amounts of mass loss.

它们会释放出这些高能星风。

They're blowing these high power winds.

在生命历程中，它们会不断喷出物质。

They're spewing matter out as they do this, as they go through their life.

它们将持续不断地损失质量，反复不断地流失。

They're gonna just keep shedding mass, keep shedding mass, keep shedding mass.

当它们发生超新星爆发时，最终形成黑洞的部分，是在爆发抛掉大部分大气层后残留的，以及经历数百万年剧烈质量流失后剩余的。

When they go supernova, the part that becomes the black hole is what's left after you explode out most of your atmosphere and after you've gone through this few million years of massive amounts of mass loss.

所以问题在于——我们仍在努力理解质量流失率。

So the question is, and we're still trying to come to terms with mass loss rates.

核心问题是：恒星生命末期究竟能保留多少质量？

The question is, how much mass can be retained by the end of a star's life?

目前有少数研究者认为这个数值应该小于10。

And there's a few people out there that are arguing that it's going to be a number under 10.

那么这就引出了一个问题：还有什么其他方式能形成这些大型黑洞呢？

So this starts to be, well, what other ways do you make these big black holes?

显然，你可以让黑洞相互碰撞。

And you could collide black holes together, obviously.

没错。

Yeah.

把两个黑洞挤压在一起就能得到一个更大的黑洞，再继续挤压就能得到更大的。

Smoosh two black holes together and you get a bigger black hole, and then smoosh more together and you get an even bigger black hole.

所以真正令人惊讶的并不是数百万倍太阳质量这个数值本身。

And so it's not like what was surprising was the millions of times the mass of the Sun.

有段时间里，人们确实难以理解如何能这么快形成如此巨大的黑洞。

For a while there, people could understand how you could get a black hole that big that quickly.

确实如此。

Yes.

这其实也是我们之前讨论过的另一个谜团。

And this is sort of one of the other mysteries that we had talked about.

我知道在我们研究过程中，这个关于超大质量黑洞和围绕它们的星系谁先谁后的想法，因为这两者似乎以某种方式紧密相连。

I know sort of midway through our run, this idea of, like, which comes first, the supermassive black holes or the galaxies around them, because the two do seem to be kind of locked together in some way.

而现在看起来这个谜团大部分已经解开，这是一个自下而上的过程，随着这些星系聚集形成，而非自上而下的方式。

And now it really kinda looks like that mystery has been mostly solved, that it is the bottom up process as these galaxies come together, not the sort of the the top down way.

所以

So

看起来实际上是两者都有。

It's looking like both actually.

所以最早期的黑洞并非黑洞。

So there is evidence that the earliest black holes not black holes.

嗯，它们也是。

Well, them too.

最早期的巨大椭圆星系可能是通过一种混沌坍缩过程形成的，在这个过程中，坍缩物质云中的湍流既允许了足够冷却使这种坍缩得以发生，同时也促成了超大质量黑洞的产生。

The earliest massive elliptical galaxies may have formed through a chaotic collapse process where it was turbulence in the collapsing cloud of material that allowed both sufficient cooling to allow that kind of a collapse to take place and also allowed the generation of the supermassive black hole.

因此，如果你试图弄清楚宇宙最初几百万年里我们如何最终形成巨大椭圆星系，以及我们今天看到的所有恒星形成星系是如何形成的，你需要有两个不同的答案。

So if you're trying to figure out how do we end up with massive elliptical galaxies in the first few million years of the universe, and how do you end up with all of the star forming galaxies that we see today, you need to have two different answers.

看来像我们银河系这样的普通星系正是这种自下而上的形成方式。

This is where it looks like everyday galaxies like our Milky Way are this bottom up.

我们只需让物质在角动量守恒等条件下温和地碰撞结合。

Let's just slam things together gently conserving angular momentum and such things as that.

但同时也要允许这些暗物质晕发生剧烈湍流坍缩，形成那些早逝的巨型椭圆星系。

But let's also allow within these dark matter halos to have this turbulent fabulous collapse down to form massive ellipticals that died young, died fast.

詹姆斯·韦伯望远镜一旦发射，将有望让我们观测到这些现象。

James Webb, should it ever launch, will allow us to hopefully observe these.

是啊。

Yeah.

我们刚才讨论了一类曾被遗漏的黑洞，现在已开始发现相关证据。

So we talked about one class of kind of missing black holes that we're starting to see some evidence.

另一种理论预测的黑洞是原初黑洞。

The other one that was theorized is this idea of primordial black holes.

没错。

Yes.

有任何证据支持这一点吗？

Any evidence for that?

这就是我们要看引力波观测结果的地方。

So this is where it comes down to what are we seeing with the gravitational waves.

如果你查看所有已被确认的黑洞列表。

If you look at a list of all the black holes that were like, yes, that is a black hole.

除了几个数据尚不确定的奇怪例外。

With a couple of weird exceptions that we're not sure about the data on yet.

似乎所有质量超过15个太阳的黑洞都是通过引力波被探测到的。

It appears that all of them that are bigger than 15 solar masses are detected through gravitational waves.

而通过极其细致的观测，我们发现了一些质量约为7个、10个甚至4个太阳的黑洞。

And if by looking around in huge amounts of detail, we're finding things that are like seven solar masses, 10 solar masses, four solar masses.

但通过引力波，我们探测到的却是36、31个太阳质量的黑洞。

But with gravitational waves, we're finding 36, 31.

这似乎显示出当前发现存在某种质量区隔现象。

There seems to be this segregation in what's being found.

因此，我们通过引力波发现的这些30至36个太阳质量的黑洞，可能是中等质量黑洞中最小的那一类，它们可能是宇宙微波背景辐射释放之前遗留下来的原初黑洞。

So it could be that these thirty, thirty six solar mass black holes that we're finding through gravitational waves may be the smallest of the intermediate mass black holes that may have been primordial black holes left over from prior to the release of the cosmic microwave background.

但那些小家伙呢？

But what about the little guys?

比如质量相当于一栋房子或一颗小行星的那些？

Like the ones with, say, the mass of a house or the mass of an asteroid?

是的。

Yeah.

我们目前还找不到那些。

We can't find those yet.

这曾被理论化为暗物质的解释之一，不过现在已经没人相信这个说法了。

And this has been theorized to be one of the explanations for dark matter, except now nobody believes that.

没错。

Right.

试图将质量小于太阳的微型黑洞归咎于暗物质，或将暗物质归咎于它们的问题在于：如果霍金辐射理论是正确的，那么它们应该正在蒸发。

So the problem with trying to blame tiny baby, like, under the mass of the sun black holes on dark matter or blaming dark matter on them is if Hawking's was right, then they should be evaporating.

所有那些微观级别的极小黑洞应该早就噗地一声消失了。

And all the baby baby microscopic tiny tiny tiny ones should have gone poof early on.

而那些稍大一些的黑洞现在应该正在蒸发，我们应该能看到黑洞蒸发产生的某种背景辐射，但我们并没有观测到这种现象。

And the ones that are a little bigger should be going poof right now, we should see some kind of background radiation from black holes evaporating, and we don't see that.

所以我们从未观测到符合理论预测的蒸发辐射特征。

So We've never seen the right color of poof.

没错。

Right.

所以如果它们存在的话，它们的质量会比黑洞小，但仍然相当巨大。

So if they are out there, they are more massive, but less massive than black holes.

这依然是值得寻找的迷人事物。

Still a fascinating thing to be looking for.

好吧。

Okay.

你知道什么会很棒吗？

You know what would be great?

一张超大质量黑洞事件视界的真实照片。

A actual photograph of the event horizon of a supermassive black hole.

进展如何了？

How's that coming?

我们正在努力。

We're working on it.

他们差不多一年前就拍了照片，但人们一直不停地烦我。

They took the picture, like, almost a year ago, and people won't stop nagging me.

这不是你的错。

It's not your fault.

所以我要问你，我们什么时候能看到事件视界望远镜拍的照片？

So I'm gonna ask you, when do we get to see a picture from the Event Horizon Telescope?

这不归我管。

Not my responsibility.

我只高兴盖亚昨天发布了数据。

I'm just happy that Gaia dumped data yesterday.

这简直让人难以置信。

That is mind bending.

不过我们还是先给大家解释一下什么是事件视界望远镜。

So but let's tell people what the Event Horizon Telescope is.

也许再过几年，我们就能提供新的进展了。

And so maybe in a couple of years, we can give that update.

当时许多天文学家集中了大量资源，试图同时观测黑洞的事件视界——'试图'这个词用得很准确。

So a whole lot of astronomers pooled a whole lot of resources to simultaneously try, try being the optimal word to observe the event horizon of a black hole.

他们使用的是射电望远镜阵列。

When they did this, they were using radio telescopes.

这是非常长基线干涉测量技术。

This was very long baseline interferometry.

他们将遍布全球的射电望远镜联合起来，这些望远镜来自不同国家、不同机构，种类各异。

You group together a whole bunch of radio dishes all over the world, different countries, different organizations, different kinds of telescopes.

必须极其精确地记录观测时间，否则图像将永远无法匹配成功。

You very, very carefully record the time that you're observing where you were condemned forever to not be able to match up the images.

然后你将所有数据合并处理

You then combine all the data.

之所以能这样做，是因为无线电波长足够长，我们可以记录并实际追踪其波形调制

And you can only do this because radio wavelengths are sufficiently long that we can record them and actually track their modulation with the waves.

所以你记录下所有数据

So you record all the data.

然后将所有数据发送到一个中心地点

You then send it all to one central place.

进行所谓的条纹搜索，即对齐所有信号，确保所有望远镜在完全相同的时间观测完全相同的入射波

You do what's called fringe finding, which is aligning everything so that all of the telescopes are essentially observing the exact same incoming waves at the exact same time.

当你完成所有数据合并工作，并因为某人的时钟不准而对其吼叫后，就能得到现代技术能力范围内最高分辨率的图像

And when you are done combining all of this data and you have yelled at somebody because their clock was off, you then have what is the highest resolution possible image for modern technological capabilities.

他们的目标是观测人马座A星

Their goal was to look at Sag a star.

这是银河系中心的黑洞

This is the black hole in the center of the Milky Way galaxy.