了解宇宙是如何运行的（2010）

How the Universe Works S05E09

Part 3 April 18, 2021, 7:48 p.m.

The night side is a dark, frozen wilderness,
白天是一片阳光普照的沙漠
the day side, a sunblasted desert.
但在这两者之间存在着生命的希望
But between the two lies hope for life.
在永恒的黄昏中
A long, thin strip of land in permanent dusk wraps
一条又长又薄的陆地
around the planet like a ribbon.
像丝带一样环绕着星球
Jani radebaugh pictures an eerie twilight zone
黑暗的冰川融化
where dark glaciers melt
填满了广阔的泻湖
to fill vast lagoons
就像地球的冰川在夏天一样
just as earth's glaciers do during the summer.
雷德堡：这两个完全不同的
Radebaugh: The boundary between these two
景观之间的界限
completely different landscapes
就像我们现在所处的地方一样
is something like what we're sitting on right now.
通常情况下，会有液态水从这些冰川中流出
Basically, we would have liquid water
从这些冰川上流下来
flowing off of these glaciers, pouring off the glaciers
流淌下来，流入这片荒原
and heading out into the wasteland
冰山崩落，形成这个美丽的海湾
and icebergs calving off into this beautiful bay.
我们有液态水
We've got liquid water.
还有从燃烧的太阳那里得到能量
We've got energy from this burning sun.
所以这正是
And so this is exactly the kinda place
我们寻找生命的地方
where we would look for life.
围绕太阳最近邻居
A ring of hope for life on a planet
运行的行星上有可能存在的生命的环形地带
orbiting the sun's nearest neighbor.
proxima b真的是外星文明的家园吗？
Could proxima b really be home to alien civilizations?
在我们去那里之前，尚无定论
Until we go there, the jury's out.
但是红矮星可以燃烧上万亿年
But red dwarfs burn for trillions of years.
他们的数量
And they outnumber the other stars
是其他恒星的三倍
in the sky three to one.
如果先进的外星文明
If advanced alien civilizations
真的存在
really are out there,
红矮星的行星可能是
the planets of red dwarf stars
找到它们的理想场所
could be ideal places to find them.
假设我们坐在一个行星上
Let's say that we were sitting on a planet around
围绕着一个红矮星
one of these red dwarfs, maybe a trillion years from now.
也许是一万亿年后，我们仍然坐在这里
We could still be sitting here.
我们还没见到过红矮星的死亡
We've never seen a red dwarf die.
所以如果这是真的
And so if that's true, then there's plenty of time
那么生活就有足够的时间让生命起源发展了
for life to have gotten started.
所以不仅会有微生物的生命
So not only do we have microbial life,
也许还有更复杂的生命
but maybe even more complex life
然后再进一步
and then take it a step further.
甚至有可能在这些地方有智慧的生命
We might even have intelligent life in these locations.
令人惊奇的是
It's amazing that even tiny stars
即使是很小的恒星也可能有潜在的可居住的岩石行星
can have potentially habitable rocky planets,
不管这些行星有多怪异
no matter how weird these worlds may turn out to be.
但当天文学家把望远镜转向
But when astronomers turn their telescopes
更大的恒星时
to bigger stars,
惊喜就接踵而至
the surprises keep coming.
这些太阳大小的恒星也有行星
These sun-sized stars have planets, too.
其中有一些可能非常古怪
And some of them could be the weirdest yet.
想象一下
Imagine a gas planet
一颗非常黑的气体行星似乎正在吞噬光线
so black it appears to be eating light.
二十多年来
For over two decades,
天文学家一直在扫描天空寻找外星世界
astronomers have scanned the heavens for alien worlds.
他们发现，到处都能找到系外行星
And they've found them
几乎到处都是
pretty much everywhere they've looked.
他们希望发现多个
They hope to discover multiple planets
像地球一样行星
just like the earth.
但是相反
But instead, they've uncovered
他们发现了一个到处充满奇异的星系
a galaxy filled with the bizarre.
当你搜寻所有这些系外行星时
When you search for all of these exoplanets,
你可以看到宇宙是一个有着丰富的想象力世界
you can see that the universe has a vivid imagination.
其中一些有超重力
Some of them have super gravity.
有两颗恒星的星系而不是一颗恒星
Others have two stars and not one.
有各种有趣的结构
There are all kinds of interesting configurations.
2011年，天文学家大卫·基平（David kipping）
In 2011, astronomer David kipping
正在审查一颗气体巨星的数据
was reviewing data on a gas giant
该气体巨星正紧紧围绕着一颗遥远的恒星运行
that was closely orbiting a distant star.
当他研究母星的亮度时
As he studied the brightness of the parent star,
他发现了一些非常奇怪的东西
he found something really weird.
看起来这颗绕轨道运行的行星正在吞噬恒星的光芒
It looked like the orbiting planet was eating light.
当我第一次看到这些数据时
When I first saw this data,
我真的以为我们犯了个错误
I actually thought we'd made a mistake.
我想“我们一定把分♥析♥搞砸了”
I thought, "we must've screwed up in our analysis."
大卫在测量
David was measuring the brightness of the star
恒星从迎光面转到背光面时的亮度
as it went from its day side to its night side.
根据预测
It had been predicted that the brightness
亮度将显著下降
would drop significantly.
但实际上，光照水平只下降了一点点
But instead, there was only a tiny drop in the light levels.
唯一的解释是这颗行星
The only explanation was that the planet
几乎没不反射任何光线
was barely reflecting any light at all.
这颗行星名叫 tres-2b
This planet, tres-2b,
反射的光线不到它接收光线的1%
reflects less than 1 percent of the light which hits it.
所以比黑色丙烯酸漆要深
So that's darker than black acrylic paint.
可能比你手里拿着的一块煤
That's darker than a piece of coal
还要黑
that you might hold in your hand.
它比你生活中遇到的
And it's darker than virtually any material
任何物质都要黑暗
you will ever encounter in your life.
出于这个原因
And for that reason, we started
我们开始给这个星球起绰号♥叫黑暗骑士
to nickname this planet the dark knight.
黑色物体之所以看起来是黑色的
Black objects appear black
因为它们吸收了照射到它们表面的大部分光线
because they absorb most of the light that hits them.
物体吸收的光线越多
The more light an object absorbs,
它看起来也就越黑
the blacker it appears.
但黑暗骑士是有非常强烈的黑色
But the dark knight is so intensely black,
它几乎是吃掉了它周围的光线
it almost appears to be eating the light around it.
这颗奇怪的行星还有另一个秘密
And this weird planet has another secret:
它离它的主星如此非常近
It sits so close to its star
以至于它的大气层
that its atmosphere reaches
达到了令人难以置信的温度
incredible temperatures ...
2000华氏度（约1093摄氏度）
2,000 degrees fahrenheit,
热得足以熔化黄金
hot enough to melt gold.
黑暗骑士
Could the dark knight's scorching
炽热的大气层能
atmosphere help explain its weird,
解释它的怪异吗？
ultra-dark appearance?
基平:在这颗系外行星的大气层中
Kipping: There is some very alien chemistry
发生了一些非常奇怪的化学反应
happening in the atmosphere of this exoplanet.
空气中会有钠蒸汽
You're gonna have vaporous sodium,
钾蒸汽
vaporous potassium,
甚至是氧化钛
maybe even titanium oxide in the atmosphere.
这些物质在地球上是固体
These substances are solid on earth.
但在这个星球上，太热了，所以它们是气体
But here, it is so hot, they are gases.
这些气体，像钠
And these gases, like sodium,
是很好的吸光物质
are excellent absorbers of light,
正是这个创造了黑暗骑士怪异的阴影外观
creating the dark knight's weirdly shadowy appearance.
通常，这种吸收
Normally, this absorption
仅限于非常窄的颜色
is limited to a very narrow color
如黄光
such as yellow light.
但这颗行星太热了
But this planet is so hot
以至于吸收特征被拓宽了
that that absorption feature gets broadened out.
然后这种吸收特性
And this absorption feature then spans
横跨整个可见光波长
the entire visible wavelength of light.
所以这颗行星看起来非常暗
And the planet basically looks extremely dark.
像黑暗骑士这样的行星
Planets like the dark knight
让天文学家着迷
fascinate astronomers because
因为这些掠过恒星的巨型行星
these star-skimming giant planets
不可能在离恒星如此近的地方形成
aren't expected to form so close to their star.
当年轻的恒星迸发出生命时
When young stars burst into life,
它们会吹走环绕它们
they blow away the gas
周围的气体和尘埃
and dust that surrounds them,
留下很少的物质
leaving little material behind to build gas planets
来建造木星大小的气体行星