英语
双语
汉语

三个极端的黑洞

Three extreme black holes
三个极端的黑洞
1022字
2019-10-13 21:16
72阅读
火星译客

Black holes are some of the most extreme astronomical objects out there.

黑洞是宇宙中最极端的天文学物体之一。

They're dense enough to pack the mass of the Earth into the size of a marble.

黑洞密度极大,可以将整个地球包裹成一块大理石的大小。

And at the heart of each one is a point of infinite density where space and time cease to exist.

每个黑洞的中心是一个无限密度的点,这里是不存在时空的。

But even among these extreme objects, there are extraordinary ones.

不过,在这些极端的物体之间,也有不同寻常的物体存在。

We're talking black holes that grow larger, consume more, and spin faster than the rest.

像是不断变大的黑洞。这种黑洞会吸食越来越多的物体,外层比内层的转速要快。

By finding and studying these outliers, astronomers get a glimpse of physics at its limits.

通过寻找并研究这些外层物质,天文学家对物理学的极限又有了一些粗略的了解。

Here are three of the most intense black holes helping them do just that.

下面介绍3种帮助科学家一览物理学极限的极端黑洞。

The most massive black hole astronomers have directly measured is located 825 million light-years away in the galaxy Holm 15A.

天文学家直接测量过的质量最大的黑洞位于Holm 15A星系中,距离我们8.25亿光年远。

It weighs in at around 40 billion solar masses. But it didn't start out that big.

该黑洞质量大概是400亿个太阳的质量,不过,该黑洞产生之初没有这么大。

To reach its mass, it had to consume almost all the matter around it, leaving basically a ghost town around its galaxy's center.

在达到这个巨大质量的过程中,该黑洞吸食了周围的所有物质,导致该星系中心周围空无一物。

According to a study submitted to The Astrophysical Journal in July 2019, this likely happened when two black holes merged.

根据2019年7月《天文物理期刊》上发刊的一项研究:当2个黑洞结合的时候,很有可能出现这样的情况。

As they danced around each other, whatever matter they didn't devour got ejected out of the region.

在2个星系彼此挨近运行的时候,他们附近的物质都被吸食殆尽。

Now, while this whopper holds the current record, pinning the blue ribbon on the most massive black hole isn't an easy job.

虽然这一特大黑洞的纪录目前还没有其他物体打破,但要确定特大黑洞上蓝色缎带的情况并非易事。

Since black holes swallow up light, we can't directly see them, which means astronomers have to get creative about their measurements.

由于黑洞会吞噬光,所以我们无法直接看到黑洞。也就是说,天文学家在测量中必须充分发挥创造力。

They got this one's mass by looking at how its gravity pulls on nearby stars.

他们通过观测该黑洞的引力是如何拉扯附近恒星来获取该黑洞的质量。

But they can also use less direct methods to gauge the mass of a black hole, like looking at the spectral lines, or chemical fingerprints, in the light surrounding it.

不过,他们也可以用间接方法来获得黑洞的质量,比如观测黑洞附近光的谱线和化学指纹图谱。

The shape of those lines can tell them how fast the source of that light is moving.

通过谱线的形状,天文学家可以了解发光源的移速。

This method is less precise, but scientists used it to measure one black hole that might be around 66 billion solar masses.

这个方法的精确度低一些,不过,科学家曾通过该方法测量过质量大概在660亿个太阳质量的一个黑洞。

And another could be as much as 100 billion!

还有一个黑洞质量高达1亿的太阳质量。

It's hard to say for sure how accurate these measurements are.

这种测量方法很难确定准确度。

But regardless of whoever ends up with the crown, all of these objects will help astronomers figure out if there's an ultimate mass black holes can achieve.

不管最后哪个黑洞的质量最大,这些黑洞都将帮助天文学家弄清楚黑洞质量可以大到多么超乎想象。

Because we're not actually sure about that. This next type of extreme black hole consumes an enormous amount of matter.

因为我们其实不是很确定。下一类极端黑洞可以吸食大量物质。

Most supermassive black holes, including the one at the center of our own galaxy, are kind of… lazy.

大多数特大质量的黑洞,包括太阳系中央的那个黑洞,其实都是比较不活跃的……

The occasional morsel might fall to its doom, but for the most part, stuff orbits far enough away that they barely eat anything.

个别的小块物体可能会被其吸食,但大多数时候,由于环形的物体距离很远,所以黑洞几乎啥也不吃。

There's a small group of them, though, the literal 1%, that astronomers call active, meaning they're constantly gobbling up matter around them.

不过,还是有一小部分黑洞,像1%的黑洞是很活跃的。“活跃”的意思是:他们一直在吸食周围的物体。

We find this type of black hole in a region called an Active Galactic Nucleus, or AGN.

我们发现这类黑洞都处于活动星系核(AGN)内。

The AGN contains the black hole, its accretion disk, and the surrounding donut of dust and gas.

AGN内有黑洞、吸积盘、周围的尘埃和气体圈。

As these black holes devour matter, the AGN emits light, in some cases, outshining all the stars in the galaxy.

由于这类黑洞会吸食物质,所以AGN会发光。有时候,其发出的光比星系中的所有恒星都要亮。

The hungriest black hole ever detected fuels an AGN around 12 billion light-years away, in one of the oldest galaxies we can detect.

目前探测到的吸食最为活跃的黑洞为距离我们120亿光年的AGN提供能量。他们位于我们能探测到的最古老的星系中。

It devours a mass equivalent to our Sun every two Earth-days, and it shines as bright as 700 trillion Suns.

该黑洞每2个地球日就可吸食一个太阳的质量,其亮度是太阳的700万亿倍。

For comparison, if this thing were at the center of the Milky Way, we could see it as a pinprick of light shining 10 times brighter than a full Moon.

比较来看:如果该黑洞位于银河系,那么就相当于一个针孔的光线,其亮度是整个月亮的10倍。

And that's about twice as luminous as typical AGN!

这个亮度大概也是AGN的2倍。

This discovery was so surprising that the team of astronomers that found it had to check the brightness they detected wasn't exaggerated by any other phenomenon.

这个发现让人震惊,因此做出该发现的天文学家必须要检测他们探测到的亮度是否因其他现象而有所放大。

For example, many AGNs have bright jets of particles streaming out of either side.

比如,很多AGN的每侧都有许多发光的粒子束涌出。

But follow-up research suggested no jets, and nothing else that could be boosting the signal.

不过,后续研究发现并无这样的粒子束存在,而且也没有其他什么能放大信号的现象存在。

So it looks like this AGN is just naturally brilliant.

所以,看起来AGN是天生丽质。

The third extreme black hole is the fastest spinner.

第3类极端黑洞的转速最快。

That prize goes to the black hole known as, well, this, and it's located in our very own Milky Way.

这个被“授予奖项”的黑洞就在银河系中。

Black holes spin because of a principle called conservation of angular momentum.

黑洞之所以会旋转是因为一个叫角动量守恒的原理。

You've seen that principle in action if you've ever watched an ice skater spin faster as they pull their arms closer to their body.

如果大家看过滑冰运动员的转速随着双臂向身体拉动而越来越快的话,就是角动量守恒在起作用。

A similar thing happens with black holes. Most black holes start out as the collapsed cores of massive stars.

角动量守恒也适用于黑洞。大多数黑洞一开始都是大质量恒星崩塌后的内核。

Those stars have some small amount of spin, and as the center collapses into a black hole, that spin gets faster.

那时候,它们的转速很小。随着中心坍缩成黑洞,转速就越来越快。

Except, with black holes, there's a little catch: For a given mass, there's a maximum speed.

不过,黑洞有个特殊之处是:对于特定质量的黑洞来说,是有转速上限的。

If a black hole has too much spin, it will actually release some of the energy in its system until it slows down to below that limit.

如果某个黑洞转速过快,那么它就会释放在其体系内释放出一些能量,直到其转速下降到这个限制之下。

So rather than saying that a black hole rotates however many times a second, astronomers assign it a so-called spin parameter.

所以,天文学家不会用每秒转多少次来形容黑洞,他们将其称之为所谓的转速参数。

That gives its speed as a percent of how fast it physically could spin.

这就给出了它的速度,它的物理旋转速度的百分比。

The current prize-holder, as of January 2019, is rotating at between 92 and 95% of its speed limit.

截至2019年1月为止,目前的纪录保持者转速在其上限的92%-95%之间。

So, it might not be the fastest-spinning black hole ever, but so far, it's the one spinning closest to its physical limit.

所以,虽然该黑洞并非转速最快的黑洞,但它却是离转速上限最近的黑洞。

Astronomers can't measure a spinning black hole itself, of course.

当然了,天文学家自己是无法测量黑洞转速的。

So they rely on clues in the light around it. But actually measuring a black hole's spin is actually pretty complicated, since there's a lot of light interfering with the signal.

所以科学家只能依赖于黑洞附近的光。不过,实际上,测量黑洞的转速实际上是十分复杂的,因为有很多光干扰信号。

As a result, astronomers only have accurate measurements for half a dozen black holes with really high spin parameters.

因此,科学家只能精确测量几个转速参数很高的黑洞。

Meaning, again, this title could be up for grabs.

也就是说,这个是很好办的,就看谁动手快了。

But as our technology improves and we find new record-setters, these extreme black holes will keep giving us ways to test our predictions about the limits of physics and reality as we know it.

不过,随着科技的进步,我们发现新的黑洞打破了记录,这些极端黑洞会不断为我们提供预测物理学极限和真实情况的方法。

Extreme black holes can get pretty complicated, but if you're interested in keeping life simple, The Ridge can help with that.

极端黑洞有时候非常复杂,但如果大家想简化了解的话,可以通过Ridge。

0 +1
举报
0 条评论
评论不能为空

Ice Pop的内容