与摩根·弗里曼一起穿越虫洞（2010）

Through The Wormhole With Morgan Freeman S01E05

Part 3 April 19, 2021, 2:24 p.m.

残留下来
of that delivery experience.
所以我们在实验室里设计了实验
And so we set out to test this in the laboratory.
珍·布兰克工作于
Jen Blank works at SETI,
搜寻外星智能项目
the Search for Extraterrestrial Intelligence,
但她对外星人不感兴趣，她主要研究外来分子
but she's not interested in E.T. so much as alien molecules.
她搞了个电脑模拟
So she's developed a computer simulation
看看碰撞时发生什么
to see what happens to them on impact.
迎头而撞的彗星希望不大
Comets that hit earth head on are not very promising.
碰撞几乎完全将其烧成灰烬
The collision almost completely incinerates them.
在这段影片里蓝色是较低温度
In this movie, the blue colors are cold,
向着红色♥区♥域，温度越来越热
and as you go toward the red, it gets hotter and hotter.
我们预料普通的碰撞
And so we expect the normal impact
产生最极端的条件
to have the most extreme conditions.
你能看到，没有蓝色
You can see there's no blue color,
材料肯定都要蒸发或挥发了
so essentially the material's all volatilized or vaporized.
但是，如果彗星做一次偏斜的碰撞
But when a comet makes a glancing blow,
它不会化为灰烬
it doesn't incinerate.
它会融化，将大量的水和氨基酸
It melts and dumps massive amounts of water and amino acids
散布到我们的原始星球
on our primeval planet.
这次，我们试一下
This time, we're coming in
和水平面15度的倾斜碰撞
at a 15-degree angle from the horizontal.
看到蓝色了
Watch the blue,
这里会有液态水
which will correspond to the liquid water.
你可以看到大量的水跑掉了
So you can see a lot of the water's going away,
但是仍然有大概20%的保留下来
but you still are retaining somewhere on the order of 20%
以液态水的形式分散开
that's being delivered as liquid water.
但是这些模拟
But these simulations
只是追踪了彗星撞地球的
only track the temperature of the comet
温度分布
as it crashes to earth.
要知道氨基酸会怎么样
To see what happens to the amino acids,
珍需要利用强大的火力
Jen needs to get her hands on some serious firepower.
如果你想给枪或类似什么东西照个像
Here's where you might want to have
就来这儿吧
a picture of a gun or something.
这是加州理工学院的震动实验室
This is the shockwave lab at Caltech.
实验室的自豪和骄傲
Its pride and joy --
一个65英尺长的大炮能够把发射的物体
a 65-foot-long gun capable of firing projectiles
加速到超过每小时1万6千英里
at over 16,000 miles per hour.
这是珍的子弹
And this is Jen's bullet.
让我们把它当作彗星
Let's imagine this is a comet.
它是个金属罐里面充满液体
It's a metal cannister with a liquid fill volume
由水和溶解的氨基酸组成
that contains water and dissolved amino acids.
在我们的实验里
And, in our experiment,
我们用它来测试彗星撞击地球时
we want to test the the response of this
会发生什么情况
to a collision with an earth.
这实际上是一个两段炮
This is actually a two-stage gun,
在远端
and at the far end,
我们用火♥药♥压缩气体
we use gunpowder to compress gas.
当火♥药♥点燃
The gunpowder's ignited,
压缩空气猛烈冲击抛射体
and the compressed air slammed into the projectile,
推着它穿过炮管
and sends it traveling down the barrel of the gun
加速到大概每小时2千到3千英里
at velocities of around 2,000 to 3,000 miles per hour.
这模拟了彗星和地球之间
This corresponds to an oblique-angle impact
倾斜的碰撞
between a comet and a rocky Earth.
为了模拟这场天地大冲撞
To simulate this glancing interplanetary blow,
珍妮佛控制了大炮的最高出膛速度
Jennifer dials down the gun from its maximum muzzle speed
祈祷她的罐子和里面的载货能够幸存下来
and prays her cannister and its payload will survive.
碰撞时产生的温度
Temperatures in these impacts
能够高达上千摄氏度
would be essentially thousands of degrees centigrade.
这可是真正极端的条件
So these are really extreme conditions.
300伏，就位
300 volts. Ready.
闻到了么？
Smell that?
那是枪药儿，枪药的味儿
That's the gunpowder, the gunpowder smell.
实验容器被射入这个大罐子
The capsule is sent into this larger tank,
此罐被称为失而复得罐
which is called the recovery tank.
大概有2吨♥重
It weighs about 2 tons,
它可真的能经住冲撞
and so it really muffles the collision.
而且，真的在实验结尾
And, really, at the end of the experiment,
如果情况正常
if all things go well,
它会和实验开始时差不多
it looks much the same as when we first started.
现在，珍打开了实验容器
Now Jen breaks open the bullet capsule
取样经过撞击的内容物
to retrieve its smashed contents and discover what happened
看看这些有机化合彗星汤是什么情况
to this cometary soup of organic chemicals.
这是一个样本其中有两种不同的氨基酸
And here's an example with two different amino acids in it --
氨基乙酸，最简单的氨基酸
glycine, which is the simplest amino acid,
还有脯氨酸，另一种氨基酸
and proline, which is another one.
这是最初的溶液你看，只有两种成分
And here's the initial solution. You can see just two.
这是后来的溶液分♥析♥
Here's an analysis of the solution afterwards.
最主要的副产品
The most high-abundance byproducts
看来是两种简单氨基酸的
turned out to be all combinations
组合产物
of the first two amino acids.
我们真的很兴奋
So we were actually very excited
因为碰撞导致的反应
because the reactions that were occurring
确实产生了更大的生物学意义的分子
were actually forming larger biologically relevant molecules.
珍的大威力实验表明
Jen's high-powered experiment
彗星也许真的撞击早期地球
suggests comets may have bludgeoned early Earth
使之向生命更近一步
one step closer to life.
它们帮助氨基酸结合
They helped amino acids join together,
甚至可能组成原始蛋白质
perhaps even forming primitive proteins.
在构建更大的生物学意义上的分子试验中
We're actually harnessing the power of the impact
我们控制了撞击的能量
to build larger biologically relevant molecules.
这可能是构成原始生命的
So this could have been a dominant source
基本材料的主要来源
of the building blocks that led to the origin of life.
我们通常以为40亿年前，我们的星球是个
We used to think our planet was a hellhole
危险的地方
4 billion years ago,
任何生命的火花都会被马上扑灭
where any spark of life would have been instantly incinerated.
现在，我们了解到彗星里有生命的化学成分
Now we know the chemicals of life were inside comets,
如雨般落向我们的星球
raining down on our planet.
它们并未坠毁燃烧
And they didn't crash and burn.
它们兴旺昌盛
They thrived.
但是其它的生命原料还没着落
But other ingredients of life are still missing.
位居通缉名单首位的是DNA
At the top of the wanted list is DNA,
携带我们基因信息的分子
the molecule that carries our genetic identity.
现在，一个人可以破解遗传密♥码♥
Now at last, one man may have cracked the code
明确最初的DNA排列
to the origins of DNA itself.
生命进化成为
It's taken 4 billion years
如同你我的复杂有机体
for life to evolve
花了40亿年的时间
into organisms as complex as you and me.
我们处于
We're at the tip
进化树的顶端
of a tall branch of the tree of life.
在大树的根部深处是微生物
Down in the deepest roots are microbes
只由单细胞组成
whose bodies are just a single cell.
但是微生物的生理活动就像我们一样
But each microbe's biology is just like ours.
无论看上去有多么不同
No matter how different it looks,
共性在于那一缕DNA
its identity resides in a strand of DNA.
进化树中，每一种我们所知的生命体都是如此
Every living organism we know belongs somewhere on this tree.
但是为什么进化树植根于这最初的土壤
But why did the tree of life grow in the first place?
要解决这个神秘问题我们要先找到种子
To solve that mystery, we have to find the seed.
科学家对进化树的种子所知不多
Scientists don't know much about this seed,
但他们对一件事很肯定
but they are sure about one thing.
地球上的每个生物体都有一个共同点
Every living organism on earth shares one common feature --
都有一张膜
a tough outer layer
将它们和外部的世界分隔开
that separates it from the world outside.
每个细胞都有细胞膜
Every cell has a membrane.
生命的第一颗树种也一定有细胞膜
The first seeds of life must have had one, too.
呃，我们认为，我们需要这种原始的细胞膜
Well, we think we need this kind of primitive cell membrane
这样才能把基因分子裹在里面
to keep the genetic molecules trapped inside.
不可能让这些东西流的到处都是啊
You can't just have everything diffusing around.
一定要有这种分隔
You have to have things compartmentalized.
哈佛医学院的杰克·绍斯塔克
Jack Szostak at Harvard Medical School
正致力于解决生命的最大谜团
is on a quest to solve one of life's biggest mysteries --