了解宇宙是如何运行的（2010）

How the Universe Works S05E01

Part 4 April 18, 2021, 7:46 p.m.

So panspermia is the idea that life Rose on some other
从其他行星或环境中产生
planetary body or other environment and came to earth
然后通过坠落的碎片来到地球
and was delivered by falling debris.
生源说始于41亿年前的
The panspermia argument begins with a game
一场宇宙弹珠游戏
of cosmic pinball 4.1 billion years ago.
太阳系的外行星
The outer planets of the solar system
还没有进入稳定的轨道
haven't yet settled into stable orbits.
他们在“争夺地盘”
They jostle for position.
引力的博弈使得巨大的小行星冰雹
The gravitational fallout sends a hail of giant asteroids
向地球袭击而来
towards the earth.
这被称为“晚期重轰炸”
It's called the late heavy bombardment.
我们地球正非常开心地绕着太阳公转
We're just orbiting the sun, happy as can be,
而外行星正把这些巨大的物体
and the outer planets are throwing
向我们扔过来
these gigantic objects at us.
他们不停地扔过来、扔过来
And they just kept coming in and kept coming in
扔过来……
and kept coming in.
如果脆弱的生物
If delicate organisms
在早期的海洋中发育起来的话
had developed in the early oceans,
那么晚期重轰炸就会把它们全部消灭
the late heavy bombardment would have wiped them out.
但地球并不是唯一受到攻击的星球
But the earth wasn't the only planet in the firing line.
小行星也会撞击火星
Asteroids also hit Mars,
那时火星是一个非常不同的星球
and back then, Mars was a very different planet.
已经有了进化的迹象
With an evolutionary head start,
火星在这个阶段可能已经发展出
Mars could have developed Hardy bacterial life
耐寒的细菌生命并生活在地表岩石的深处
by this stage, perhaps living deep within the surface rocks.
我们在地球上看到过隐匿的内石器时代的生命
We've seen life on earth that are cryptoendolithic,
所以它们隐藏在那些岩石中
so they hide in those rocks,
它们通过隐藏在岩石内部并繁衍生息
and they survive the radiation and the harsh environment
在辐射和恶劣的环境中生存
by hiding and thriving inside of that surface.
早期火星表面的一次巨大冲击
A giant impact on the surface of early Mars
可能将充满细菌的岩石抛向太空
could have thrown rocks filled with bacteria high into space.
麦凯:这些是预先包装好的生物，随时准备起飞
McKay: These are organisms prepackaged, ready to fly.
你可以想象它们中的一些生命被困在岩石中
You could imagine some of them trapped in a rock,
然后被踢出所在星球
kicked off a planet, flying through space,
在太空中飞行了几千年后，降落在另一个世界
thousands of years later landing on another world,
突然被打开，并能够继续繁殖和生长
popping open, and being able to reproduce and grow.
那么，火星的岩石是否在晚期重轰炸末期
So, did a martian rock seed the earth with life
为地球播下了生命的种子呢？
toward the end of the late heavy bombardment?
这是可能性真的难以置信
It's an incredible possibility.
但是，火星生命是如何在太空长途旅行中
But how could the Mars bugs have survived the long journey
存活下来的呢？
through space?
地球上的某些细菌
Certain bacteria on earth,
当它们经历了一个紧张的环境时
when they experience a stressful environment,
它们开始形成我们所说的孢子
they start forming what we call spores.
孢子，如果你想象一颗种子
And spores, if you imagine a seed,
在中间有所有的遗传信息
has all of the genetic information in the middle,
它被许多层防御保护着
and it's protected by numerous layers of defense.
它们把自己封在小飞船里
They really seal themselves up in little spaceships,
这样它们就能在太空中生存
and that would allow them to survive in space.
你把孢子带到太空并再带回来
You could take a spore, put it in space, bring it back,
它们仍然可以存活
and it would still be viable.
孢子还能让细菌在休眠状态下
Spores also allow bacteria to stay alive in a dormant state
存活很长一段时间
for incredible lengths of time.
地球上有一个记录，有一种孢子
The record on earth is a spore that formed
它形成于恐龙时代之前
before the age of the dinosaurs
经过2.5亿年的休眠后，最近又复活了
and was recently resurrected after a 250 million-year nap.
你知道…在理论上，孢子可以存活
You know that ... that spores can survive in theory
达数百万年之久
for millions and millions of years,
但要真正看到孢子复活的证据
but to actually see evidence of a spore being revived
是相当神奇的
is pretty fantastic.
生源说的最后一个障碍是
The final hurdle for panspermia
在地球表面的着陆
is the fiery touchdown on the surface of the earth.
行星科学家们用高速枪♥模♥拟猛烈的撞击事件
Planetary scientists simulate violent impact events
看看火星上的细菌
with high-speed guns to see if martian bacteria
是否能够存活下来
could have survived.
并不是所有的弹丸都在撞击中
Not every bit of the projectile is destroyed
被摧毁并受到强烈冲击
and highly shocked in an impact.
当我们做这些实验的时候，我们经常
When we do these experiments, we often find little bits
会在撞击室里发现残留的弹丸碎片
of the projectile left over in the impact chamber.
如果有细菌生活在岩石的那部分
If there are bacteria living in that portion of that rock,
它们就有可能在返回地球的冲击中幸存下来
they could potentially survive the impact back onto the planet.
科学告诉我们生源说是有可能的
The science shows us that panspermia is possible,
但它会让我们更多地了解
but does it take us any closer to understanding
生命的起源吗？
the origins of life?
生源说的根本问题在于
The fundamental problem with panspermia is that
它只是解决了一个问题
it's just removing one step of the problem
生命从一个地方放到了另一个地方
and putting it someplace else.
我们不知道生命到底是如何起源的
We don't know how life originated on earth.
现在它将起源于火星
Now it's going to originate on Mars,
但我们不知道它是如何起源于火星的
but we don't know how it originated on Mars.
所以你仍然有这个基本的问题
So you still have this basic problem, and that is,
生命是如何起源的？
how did life start?
我们的祖先是从太空中来的
Did our ancestors arrive from space,
还是从地球上的海洋来的？
or did they rise up from the oceans of the earth?
把原子强烈地撞到一起，使它们粘在一起
Pushing atoms together so strongly they stick
这叫做核聚变
is called nuclear fusion.
这是将一个充满气体的宇宙
It's the first step for turning a universe full of gas
变成一个充满行星、人类和汽车的宇宙的
into one filled with the ingredients for planets,
第一步
people, and cars.
那么，如何让两个原子融合呢？
So, how do you get two atoms to fuse?
这家伙从14岁起就在他的车♥库♥里这么干了
This guy's been doing it in his garage since he was 14.
泰勒·威尔逊痴迷于核聚变
Taylor Wilson is obsessed with nuclear fusion.
邻居们都知道车♥库♥里
Yeah, the neighbors know about the radioactive stuff
有放射性物质
that's in the garage.
政♥府♥也知道
And so does the government.
都是相对较低的水平
It's all relatively low level.
我的表响了
That's my watch going off.
我想我是你见过的唯一一个
I think I'm the only person I've ever met
有盖克计数表的人
with a geiger-counter watch.
泰勒的核反应堆洞穴的核心
The centerpiece of Taylor's nuclear man cave
是他在高中时建造的
is this precision-engineered fusion reactor,
精密工程聚变反应堆
which he built when he was still in high school.
好吧，我现在放点汽油进去
Okay, I'll let in some gas now.
第一种配料……氢气
The first ingredient ... hydrogen gas.
然后通过这个精确的宝蓝色防漏阀
And it will be flowed into the chamber through this very
流入腔体
precise sapphire leak valve.
下一个配料……高压电力
The next ingredient ... high-voltage electricity.
泰勒让高电压
Taylor passes a high voltage
通过反应堆内部的
through a small, spherical cage
一个小球形笼
that sits inside the reactor.
带负电荷的笼子
The negatively charged cage
很快就把氢离子吸进来
quickly draws the hydrogen ions inside it.
所以它把所有的离子
So it's taking all those ions
都吸向中心
and sucking them towards the center.
当它们飞进去的时候
And as they fly in they get confined,
它们被限制在一起，希望它们相互碰撞并融合
and hopefully they collide with each other and fuse.
笼内原子的温度现在非常高
The temperature of the atoms inside the cage is now so great
以至于氢原子融合在一起
that hydrogen atoms are fusing together,
产生了更重的氦原子并爆发出
creating heavier helium atoms and a burst of energy
比太阳表面温度更高的能量
hotter than the surface of the sun.
那是网格线里的一小团等离子体
It's that little, tiny blob of plasma inside those grid wires
有点像罐子里的星星
that's kind of like a star in a jar.
130亿年前
13 billion years ago,
宇宙利用的是引力
the universe uses gravity to fuse atoms
而不是电来融合原子
instead of an electrical cage.
在整个宇宙中，巨大的氢气云团
Across the cosmos, vast clouds of hydrogen gas
在自身引力作用下坍塌
collapse under their own gravity.
当越来越多的气体被吸入时
Pressure and temperature build
压力和温度就会升高
as more and more gas gets sucked in.
最终，聚变在这些
Eventually, fusion sparks deep in the core
巨大的气体球的核心深处