宇宙时空之旅：未知世界（2020）

Cosmos: Possible Worlds S01E05

Part 4 Aug. 24, 2022, 10:55 a.m.

that so-called "sacred disease,"
就是我们大脑中离子通道的故障所导致
is a misfiring in the brain of our own ion channels.
想想看一大♥片♥微生物和艾萨克·牛顿
Think of it: A microbial mat and Isaac Newton,
有着上亿年的演化差别
separated by hundreds of millions of years of evolution,
但是思想传播的方式是一样的
but sharing the same basic currency of thought.
微生物在大约40亿年前
The messaging system pioneered by the microbes
开创的信息传递系统
some four billion years ago,
至今仍在我们体内
is still inside us.
看着这一片微生物 30亿年前没人想得到
No one looking at a microbial mat three billion years ago
这个单细胞有机生命体
could have predicted that the one-celled organisms
会演化成你
of life on Earth would evolve into you.
这就是生命和环境
That's what happens when living things and environments
在数十亿年中相互作用的结果
interact over the eons.
新形态的生物和意识成形
New forms and ways of being alive and aware come into existence.
当整体变得大于其各部分之和时
When the whole becomes greater than the sum of its parts,
这就叫做涌现
it's called emergence.
瞧那个看起来
See the thing that looks like a shred of a ruffle
像花哨裙子褶边的生物
from a gaudy dress?
你或许觉得它很不起眼
You might think it's kind of silly.
那你就错了
But, you would be so wrong.
很久很久以前大约6亿年前
Long, long ago, some 600 million years ago,
地球上的生命开始演化形成新的东西
life first evolved something new to planet Earth,
一个能够对于周围环境进行感知和反应的指挥中心
a command center that could perceive and react to its environment...
大脑
a brain.
现在生命能慢慢靠近恒星
Now, life inched closer to the stars.
我们认为一切都是源自扁虫
We think it first happened inside a flatworm...
这个小家伙的祖先也是最早的猎人
this little guy's ancestor, the first animal hunter.
大脑正是猎人所需要的
A brain was just what a hunter would need to
用来搜寻目标并制定袭击策略
seek out and plan a strategy for attack.
双目视觉使得扁虫对于深度的感知更加锐利
Binocular vision allowed the flatworm to perceive the
看到物体的也更清晰
dimension of depth more sharply and objects with greater clarity,
有助于更好地锁定猎物
all the better to triangulate on prey.
扁虫的大脑有一对密集的神经簇称为神经节
The flatworm brain had a pair of dense nerve clusters called "ganglia."
从那里延伸出来的神经索
Cords extended from them,
把指令和感觉通过大约八千个神经元
carrying instructions and sensations to the rest of its
传递给它身体的其余部分
body via some 8,000 neurons.
这与后来的生物相比数量并不多
Not many compared with the life forms that would come later,
但却是一个重要的开始
but a momentous beginning.
扁虫头部两侧有一对耳突
Flatworms have something called auricles on the sides
虽然是耳朵的位置
of their heads where their ears should be,
但那实际上是鼻子
but they're actually noses.
我们并不相像但我们有很多共同之处
We may not look much alike, but we have a lot in common.
我们用以控制我们神经系统的化学物质相同
We share the same chemicals that control our nervous systems,
叫做神经递质
called "neurotransmitters."
我们会对同样的毒品上瘾
We get addicted to the same drugs.
扁虫也能学习
Flatworms can learn.
会处理有关环境的信息
They process information about their environment
并据此行动
and act accordingly.
我们认为它们是自然界第一批有着前部
We think they're nature's first animals to have a front,
后部和头的动物
a back and a head,
这项设计即使在6亿年后的今天
a blueprint that remains state of the art,
仍然相当先进
600 million years later.
扁虫是真正意义上的开拓者
And they were the true pioneers in the deepest sense of that word.
与它们之前的任何生命形式不同
Unlike any life form before them,
扁虫发展出了勇闯未知领域的习性
they developed the habit of venturing into the unknown
以探寻渴求之物
territory in search of what they craved.
扁虫是很酷但扁虫的大脑和我们的大脑
Okay, flatworms are cool, but there's a big difference
有很大的不同
between a flatworm brain and ours.
我们的大脑是怎么从那样演化到现在这样的？
How did we get from there to here?
我们现在还不知道
We don't yet know.
这主要是因为大脑软软的
That's mainly because brains tend to be squishy.
它们不会在化石上留下明显的印记
They don't leave distinct imprints in the fossil record.
但大脑保留了它的演化历史
But the brain preserves its evolutionary past...
怎么说？
Why?
因为我们的大脑有点像纽约市
Because our brains are a little like New York City...
世界上大多数大城市都是随意扩张
Most of the world's great cities have grown haphazardly,
一点一点扩大
little by little,
只为顺应当下需求
in response to the needs of the moment;
很少有城市会对遥远的未来做规划
very rarely is a city planned for the remote future.
在纽约
In New York City,
许多街道的历史可以追溯到17世纪
many of the streets date all the way back to the 17th century...
证券交易所建于18世纪
the stock exchange to the 18th...
水力和电力系统可追溯到到19世纪
the waterworks and the electrical power system to the 19th century.
而通信线路建于20世纪
And the communications bandwidth to the 20th.
一座城市就像一个大脑它从一个小中心发展而来
A city is like a brain: it develops from a small center
然后慢慢成长和变化
and slowly grows and changes,
留下许多旧系统继续运作
leaving many old parts still functioning.
纽约无法为了更换高效系统
New York can't afford to suspend its water supply, or its transportation system,
就暂停供水或运输系统
while they're being replaced by something more efficient.
只能零碎地改变
Changes have to happen piecemeal.
大脑也是如此
And that's how it is for the brain.
进行演化时不可能因为大脑的古老内装不完美
There is no way for evolution to rip out the ancient
就将其通通铲除
interior of the brain because of its imperfections and
用更现代的结构来代替它
replace it with something of more modern manufacture.
大脑和城市都必须在革新期间
The brain and the city both must function continuously
持续运作
during the renovation.
所以我们的边缘系统被大脑皮层所包围
That's why our limbic system is surrounded by the cerebral cortex.
旧的部分负责太多的重要机制
The old part is in charge of too many vital mechanisms for
而不能一下子完全替换
it to be replaced altogether.
所以有时会产生不良后果
So, it's sometimes counterproductive.
但这是演化所必须的
But that's a necessary consequence of evolution.
城市是大脑皮层的礼物
The city is a gift of the cerebral cortex.
但是大脑的语言并没有被编码到基因中
But the brain's language is not encoded in the DNA of
因为生命的词汇表太小
genes because the vocabulary of life is too small.
我们的大脑需要的语言
Our brains need a language with 10,000 times
有着大它一万倍的词汇表
as many words.
人脑的信息内容
The information content of the human brain expressed
若以比特为单位来表示
in bits is probably comparable to the total number of connections
可能与神经元的连接总数相当
among the neurons...
大约一千万亿比特
about a thousand trillion bits.
如果把大脑中的所有内容抄成文字
If all the contents of your brain were transcribed into written language,
会比地球上最大的图书馆里的书还要多
it would amount to vastly more books than are contained in the largest libraries on earth.
相当于40多亿本书
The equivalent of more than four billion books
都在你的脑子里
are inside your head.
大脑是占据小空间的大世界
The brain is a very big place in a very small space.
这些信息都写在由海底微生物群
It's written in those neurons pioneered by
所开创的神经元中
the undersea microbial mats.
这些细胞是微小的电化学交换元件
These are tiny electrochemical switching elements,
通常只有数百分之一毫米宽
typically a few hundredths of a millimeter across.
我们每个人有860亿个神经元
Each of us has 86 billion neurons,
与银河系中的恒星数量相当
comparable to the number of stars in the Milky Way galaxy.
神经元及其部分轴突树突
The neurons and their parts, axons, dendrites,
突触和细胞体本身组成了
synapses and the cell bodies themselves make up
大脑中的神经网络
a network in the brain.
许多神经元和它们的邻居
Many neurons have thousands of connections
有数千个连接
with their neighbors.
树突是神经元之间相互连接的通道
Dendrites, those pathways sent out by neurons to connect with other neurons,
让神经细胞延伸至突触
extend these nerve cells to synapses until
最后会形成一个成熟的意识网络
they create a full-blown network of consciousness.
大脑的神经化学活动异常繁忙
The neurochemistry of the brain is astonishingly busy,
这套电路装置
the circuitry of a machine more wonderful than any
比人类发明的任何机器都要精妙
devised by humans.
正是因为那100万亿个神经连接
Your brain functions are due to those 100 trillion
你的大脑才能运作并成就你这个人
neural connections that make you, you.
你心底最深的爱和敬畏之情
Your deepest feelings of love and awe...
瞥见大自然的壮丽
those moments when we glimpse the grandeur of nature,
意识到建筑的优雅
and all the elegant architecture of consciousness...
都是因为那些神经连接才成为了可能
are made possible by those connections.
这就是涌现的本质
This is the essence of emergence:
微小物质单位的集体运作
tiny units of matter operating collectively
让其成为比它们自己更高级的结构