了解宇宙是如何运行的（2010）

How the Universe Works S05E01

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

构成我们今天太阳系的所有元素
that make up our solar system today,
包括你身体里的原子
including the atoms in your body.
但在此过程中，这些恒星付出了灾难性的代价
But in doing so, these stars pay a catastrophic price.
能量耗尽后，古老的恒星坍缩
Drained of energy, the ancient stars collapse
然后在超新星中爆♥炸♥
and then explode in a supernova,
将其化学成分丰富的星尘散布在太空中
spreading their chemically rich stardust across space.
你血液里的铁
The iron in your blood, the calcium in your teeth,
你牙齿和你骨骼里的钙
in your bones, these were created
这些都是在超新星爆♥炸♥中产生的
in a supernova explosion,
可能是数十亿年前爆♥炸♥的不同恒星
probably different stars that blew up billions of years ago,
在它们周围的空间播撒这些物质
seeding the space around them with this stuff.
这些复杂的原子在太空中被炸飞
Blasted through space, these complex atoms
布满了孕育新恒星的气体云中
now pepper the clouds of gas that are nurseries of new stars.
46亿年前
And 4.6 billion years ago,
一团特殊的云在自身的引力作用下开始崩塌
one particular cloud begins to collapse under its own gravity,
于是太阳被点燃
and our sun ignites.
许多古老的星尘被吸进太阳
Much of the ancient stardust is sucked into the sun,
然后再也看不见了
never to be seen again.
但这些残留物聚集在一起
But the leftovers clump together to form comets,
形成了彗星、小行星、行星，最终形成了生命
asteroids, planets and eventually life.
我认为自己是
I actually think of myself
一块非常复杂的石头
as a very complicated rock.
我是由铁、铜和锰等材料制成的
I am made of things like iron and copper and manganese.
当你坐在山坡上，在你的旁边
When you sit down on a mountainside
有一块石头，那它也是你的表亲
and you're there with a rock, those are your cousins too.
多亏了古老的超新星
Thanks to ancient supernovas, the earth forms
地球形成时拥有了创造岩石和生命所需的所有原子
with all the atoms needed to create both rocks and life.
但是，是什么把我们
But what is it that distinguishes us
和一块花岗岩区别开来呢？
from a piece of granite?
有三件事……
Three things ...
一个能量源、一个保护袋
a power source, a protective sack,
以及制♥造♥更多保护能量源的蓝图
and the plans for making more protected power sources.
DNA就是蓝图
DNA is the plan.
它是一个很长的分子，由称为核苷酸的
It's a long molecule, built up from small units
最小基本单位组成
called nucleotides.
DNA包含如何使用氨基酸小分子
DNA contains the instructions for how to build the cell's
构建细胞蛋白质引擎的指令
protein engine using small molecules called amino acids.
DNA还告诉细胞如何制♥造♥脂质——
DNA also tells the cell how to make lipids,
一种能形成完美保护袋的脂肪分子
a fatty molecule that forms a perfect protective sack.
就是这样
And that's all there is to it.
你体内有生命的基本形式——细胞
You have the basic form of life, a cell.
生命的化学设定其实很简单
The chemistry set for life is actually quite simple.
就是20个氨基酸
It's 20 amino acids.
它是一些用来制♥造♥DNA和rna的核苷酸碱基
It's a few nucleotide bases for making DNA and rna,
一些脂质，仅此而已
a few lipids, and that's it.
把它想象成乐高玩具
Think of it as like a lego kit.
最惊人发现
重金属雪
在几十亿年前
A few billion years ago,
重金属雪
如果观察我们的太阳系
when you looked in our solar system,
你可能会看到两个地球
you might have seen two earths.
好吧，几十亿年后，在未来
Well, a few billion years from now, in the future,
你也许会看到我们的太阳系
you might look at our solar system
看到两个金星
and see two venuses.
所以我们可以看到金星的过去，也可以看到我们的未来
So we can look to Venus' past and see our future.
我们知道当温度急剧上升时
We know that temperatures skyrocketed,
金星伤痕累累的表面暗示了原因
and the scarred surface hints at why.
夏威夷的火山熔岩田
Hawaii's volcanic lava fields
看起来就像金星的缩影
look like Venus in miniature.
它们都产生了同样的流状的熔岩
Both produce the same kind of runny lava,
形成了平坦的盾状火山
building flat, shield-like volcanoes.
最大的不同
The big difference
是夏威夷只有五座活火山
is there are only five active volcanoes on Hawaii.
金星却被它们所覆盖
Venus is covered in them.
金星上最引人注目的是
One thing that really jumps out all around the planet
火山的数量和种类
is the number and variety of volcanoes.
我的意思是，金星几乎可以被称为"火山世界"
I mean, Venus could almost be nicknamed "volcano world."
金星上遍布着成千上万的火山
Venus has tens of thousands of volcanoes all over the planet.
但并不是喷发的熔岩
But it's not the erupting lava
升高了金星的温度
that turns up the heat.
而是升高的温度产生了这个结果
It's what comes out with it.
近距离观察表面
Up close on the surface,
我们可以看到气体的来源
jani can see the origin of the gases.
如果我们向后看
If we look behind us,
我们可以看到火山气体从蒸汽出口喷涌而出
we can see volcanic gases gushing out of steam vents.
二氧化碳被输送到大气中
We've got carbon dioxide being delivered to the atmosphere.
这和金星上发生的情况一模一样
It's exactly like what has happened on Venus.
在火山的历史中
Carbon dioxide has been delivered out of volcanoes
二氧化碳一次又一次地从火山中释放出来
over and over and over again throughout its history
所以现在
so that now we have
金星的大气层非常厚，非常密
just a tremendously thick, dense atmosphere.
所有这些火山气体
The net result of all of these volcanic gases
从火山中喷涌而出的其结果就是
pouring out of volcanoes, major greenhouse gases,
金星在长达数十亿年的历史中
is that they have been absorbing heat
不断地吸收了的热量造成严重的温室效应
for billions of years of the history of Venus.
直到今天，温度还一直在逐渐上升中
The temperature has been gradually creeping up
金星的表面温度已经达到了900度
until, today, the surface of Venus is 900 degrees.
很难想象这种极端的温度
It's hard to imagine such extreme temperatures.
但围绕这颗行星运行的探测器
But probes orbiting the planet
探测到了它到底有多热
revealed just how insanely hot it is.
研究这些图像的科学家
Scientists studying the images
注意到这个星球的山脉上有一些奇怪的东西
noticed something strange on the planet's mountains.
貌似，在山上
It looks like, on the mountains,
有明显的雪状结构
that there's apparently snow-like structures.
但这和地球上的雪
But this is not like
明显不同
any snow found on earth.
所以，如果你看到金星上的白色山峰
So, if you look at the white-peaked mountains of Venus,
你会认为那是雪
you would think that it was snow,
但实际上是金属雨水落下来后
but it's actually metals that have rained down
沉积在山顶上造成的
and deposited on the top of those mountains.
像铋和铅这样的金属会熔化
Metals like bismuth and lead melt.
然后它们蒸发到大气中
Then they evaporate into the atmosphere.
随着大气上升，它们逐渐冷却
As they rise, they cool
直到最终像雪一样落在山顶上
until they finally fall like snow on the mountaintops.
我不确定的是
I'm not sure even the imagination
即便是科幻小说作者的想象力是否能想像出
of science-fiction authors would have come up
像金星这样奇怪的东西
with something as weird as Venus.
我是说，幻想一下这样的世界
I mean, just think about that.
山顶上竟然有“金属霜”
You have possibly metal frost on the top of mountains.
这是多么奇异的世界？
I mean, how weird is that?
这很疯狂！“金属雨”
It's pretty insane. Raining metals.
你有想过在哪里会有这个？
Where would you ever think about that existing?
在金星上
On Venus.
据预测
In the future,
未来地球上也会出现这样的金属雪
metallic snow is forecast for earth, too.
我们灼热的山顶
And our scorching mountain caps
也会像金星一样闪闪发光
will glitter like Venus.
最惊人发现
有生源说
这是自诞生5亿年后
This is the earth half a billion years
地壳已经冷却的地球
after the crust cooled.
气候温暖潮湿
The climate is warm and wet,
为生命提供基石的小行星
and the asteroids that delivered the building blocks for life
已成为遥远的记忆
are a distant memory.
一些简单的生命可能已经存在了
Some simple life may have already taken hold,
但这可能不是变成我们的生命
but this may not be the life that turned into us,
因为地球即将受到第二波
because the earth is about to be pummeled
小行星的撞击
by a second wave of asteroids,
一种被称为生源说的激进理论
and a radical theory called panspermia
认为在一些太空陨石中
suggests some of these space rocks
充满了外星生命
are filled with alien life.
生源说是指生命