了解宇宙是如何运行的（2010）

How the Universe Works S05E04

Part 3 April 18, 2021, 7:46 p.m.

它们很活跃，很年轻
So they're active, they're young.
他们现在就在流动
They're flowing right now today.
我们现在认为斯普特尼克平原
We now think sputnik planum
是一个巨大的盆地，充满了冰冻的氮
is a vast basin filled with frozen nitrogen
并由北部的山地冰川提供水源
and fed by mountainous glaciers to the north.
新鲜的氮稳定流动
This steady flow of fresh nitrogen explains
解释了为什么盆地的边缘如此光滑
why the edges of the basin are so smooth.
但是那些
But what about the regions
在冰川流动范围之外的区域呢？
that sit beyond the reach of the glacial flow?
一定有别的东西在清除
Something else must be wiping out craters
盆地中♥央♥的陨石坑
in the middle of the basin.
贾尼·拉德博(Jani radebaugh)认为
Jani radebaugh believes a weird pattern
斯普特尼克平原上的一个奇怪图案
on the surface of sputnik planum suggests
表明了一种惊人的可能性……
an astonishing possibility ...
冥王星的表面可能在沸腾
pluto's surface could be boiling.
欢迎来到斯普特尼克平原
Welcome to sputnik planum.
我的意思是，这就是
I mean, really this is what it would look like
我们站在冥王星表面的样子
if we were standing on the surface of pluto.
你看我们身后是一个巨大平坦的冰川
You see a vast, flat glacier behind us,
白色的冰川一直延伸到远处
really white extending off to the distance,
我们身后是一圈山脉
and behind us a ring of mountains.
当我们观察斯普特尼克平原的表面时
When we look at the surface of sputnik planum,
我们注意到那里……
we noticed that there ...
格子之间有规律的间隔
there are regularly spaced cells.
中间有一点圆润
And they're a little bit rounded in the middle,
边缘逐渐变细
they taper off at the edges.
这样的外观非常像是……
And they really have the appearance of something that ...
由对流形成的
that formed by convection.
所以你可以想像成一罐燕麦粥
So if you think about a pot of oatmeal,
嗯，因为它……当它沸腾的时候
um, as it's ... as it's boiling away,
它会把下面的物质带到表面
it's bringing material up to the surface
然后又把它拉回到两边
and then it's kind of pulling it back down
一次又一次地对流
again at the sides, convecting over and over again.
普特尼克平原上的氮冰
The nitrogen ice of sputnik planum
可能会像一锅燕麦粥一样沸腾
could be boiling like a pot of oatmeal,
但在任何时候
but so slowly
沸腾的表面看起来都是冰冻且缓慢的
the roiling surface appears frozen at any time.
与这类似，但要快得多的过程
A similar, but much faster,
就在地球上最活跃的熔岩湖中
process makes patchwork patterns
形成的拼接图案
in earth's most active lava lakes.
炽热的熔岩团上升
Hot globs of lava rise up,
在表面形成圆形的格子
forming rounded cells on the surface
而冷却的熔岩下沉
and cool lava sinks down,
在熔岩热泡形成的
slipping between the gaps formed
缝隙之间滑动
by the hottest bubbles of molten rock.
当我们观察斯普特尼克平原的表面时
As we look at the surface of sputnik planum,
我们所看到的基本上是一个慢动作的熔岩湖
what we're seeing is basically a lava lake in slow motion.
当温度下降时，物质上升
There's material rising up and then moving over
然后移♥动♥，再下降
and descending again as it gets cool.
然而，如果我们能想像一下
And, um, basically, if we could see that,
如果我们能让它在几千年里加速
if we could speed it up over a few thousand years,
我们就能看到表面上的单个格子
we would see individual cells
里面充满了对流的氮
all across the surface roiling and churning
会在不停地翻滚、搅动、沸腾和移♥动♥
and boiling, moving, convecting nitrogen.
你真的需要回溯这个过程
You really have to step back and realize
就会意识到这是多么神奇和奇怪
just how amazing and weird this is.
温度在零下400华氏度左右徘徊
The temperature is hovering near 400 degrees below zero.
然后就会有东西冒出来，并四处移♥动♥
And things are bubbling up and moving around.
会发生地质活动
There's geology happening.
你需要记住的是
What you have to remember is
让像氮冰这样冷的东西流动
that it doesn't take a lot of energy
并不需要很多的能量
to make something as cold as nitrogen ice flow.
但它确实是需要一些能量
But it does take some energy.
虽然冥王星的袖口上挂着一颗宏伟的心
And while pluto wears its magnificent heart on its sleeve,
但另一颗更温暖的心一定深藏在表面之下
a second, warmer heart must be deep below the surface.
但在外太空的
But out here in the frozen expanse
冰冻区域附近
of near outer space,
问题仍然存在
the question still remains,
热量从何而来？
where's the heat coming from?
2015年，“新视野”号♥探测器
In 2015, the new horizons probe
发现冥王星是一个动态的、有生命的世界
stuns mission scientists when it reveals
让执行任务的科学家们大吃一惊
pluto as a dynamic, living world.
它的冰川、山脉
Its glaciers, mountain ranges,
和可能的火山都是
and likely volcanoes are all evidence
热导致地质活动的证据
of an active geology driven by heat.
但科学家们对这种温暖
But scientists are mystified
从何而来感到困惑
where that warmth is coming from.
冥王星太小了，无法保留
Pluto is too small to have retained the heat
40亿年前猛烈创造时产生的热量
from its violent formation over 4 billion years ago.
而且它离太阳太远
And it sits so far from the sun
阳光几乎不会对冥王星产生影响
that sunlight hardly makes an impact on pluto.
现在离天亮还有20分钟
Well, it's about 20 minutes before dawn right now.
我们现在看到的光
And the light that we see is exactly the same
和正午时
as the illumination
冥王星表面的光照是完全一样的
we see on the surface of pluto at midday,
这时候太阳照射在冥王星表面的光照是最大的
when there is the maximum amount of sunlight on the surface.
由于冥王星接收到的阳光太少
And because pluto receives so little sunlight,
它的表面寒冷刺骨
its surface is bone-chillingly cold,
低至零下400华氏度
as low as minus 400 degrees fahrenheit.
这个小小的世界
This tiny little world,
离太阳那么远，接收到的阳光又那么少
so far away from the sun, receiving so little sunlight,
我是说，我们从没想过它会是一个活跃的世界
I mean, we never dreamed it would be an active world.
如果驱动冥王星地质活动的热量
If the heat that drives pluto's dynamic geology
不是来自阳光
isn't coming from sunlight,
它一定来自下方
it must be coming from below.
但从哪里？
But from where?
最好的猜测是
The best guess is that
冥王星有一个很深的地下液态水海洋
pluto has a deep subterranean ocean of liquid water
而这海洋以某种方式将热量上升到地表
and somehow this ocean is driving heat up to the surface.
有相当好的间接证据表明
There's pretty good circumstantial evidence
冥王星内部有一个巨大的水海洋
that pluto has a massive water ocean in its interior.
随着时间的推移，星球变冷
And over time as the planet cools,
水一定会结冰
the water must be freezing.
当水结冰时，它会释放，呃
And as water freezes, it releases, uh,
一种能量，叫做潜热
a form of energy called latent heat.
冰冻海洋释放出的能量
And that release of energy from the freezing ocean
很可能是
could very well be
冥王星地质活动的主要动力
what's powering a lot of pluto's geology.
结冰的水真的会让行星变热吗？
Could freezing water really make a planet hotter?
这听起来很疯狂
It sounds crazy.
但贾尼·拉德博(jani radebaugh)
But jani radebaugh can demonstrate
可以用一个冰浴
this weird quirk of physics
来代表冥王星冰冻的
using an ice bath
上层地壳，用一杯热水来代表
to represent pluto's frozen upper crust
冥王星隐藏的液体海洋
and a cup of hot water
就可以展示这一奇怪的物理现象
to represent pluto's hidden liquid ocean.
首先，冰浴
At first, the ice bath causes
使水的温度下降
the temperature of water to drop.
但是水一旦结冰
But as soon as the water freezes,
杯子里的温度就会
the temperature inside of the glass
发生惊人的变化:
does something amazing:
“它会上升”
It rises. 'Kay.
现在是30度（约零下1摄氏度），绝对可以冻住
It's at 30, so it's definitely ready to freeze.
所以我想给它一点帮助
So I just wanna give it a little bit of a helping hand
看看我们能不能让它结冰
and see if we can start it to freeze.
我们开始吧稍微搅拌一下
Here we go. Just a little stir.
哦，开始了
Oh, there it goes.
呃，现在它完全结冰了
Uh, now it's completely frozen and the temperature
温度急剧上升
is dramatically climbing,
就在它结冰的几秒钟之后
like, just seconds after it froze.