生命的奇迹（2013）

because the universe is falling to bits,
正趋向混乱
it is tending towards disorder.
这源自物理学的一个定理
That is enshrined in a law of physics called
叫做热力学第二定律
the Second Law Of Thermodynamics.
我相信大部分物理学家都认为
And I think most physicists believe
这是一个永远不会被打破的物理定律
that it's the one law of physics that will never be broken.
若想理解生命如何遵循热力学定律
The key to understanding how life obeys the laws of thermodynamics
就必须研究它吸收以及释放的能量
is to look at both the energy it takes in and the energy it gives out.
这是一个热感摄像机
This is a thermal camera,
热的东西呈现红色
so hot things show up as red,
冷的东西呈现蓝色
and cold things show up as blue.
可以看出 鸡的温度
So what you're seeing here is that the chicken is hotter
比环境温度要高
than its surroundings.
热能是一种非常无序的能量
Now, heat is a highly disordered form of energy,
所以这只鸡正在向外辐射无序的能量
so the chicken is radiating disorder out into the wider universe.
生物将化学能转换成热能
By converting chemical energy into heat,
能量因此从有序变为无序
life transforms energy from an ordered to a disordered form,
这和宇宙中的其他过程一样
in exactly the same way as every other process in the universe.
鸡
10.45焦耳/秒
雏鸡
3.1447焦耳/秒
实际上 人类每千克产生的热能
In fact, every single human being can generate 6,000 times
幼儿
39.12焦耳/秒
是太阳每千克质量产生能量的六千倍
more heat per kilogram than the Sun.
通过转换如此多的能量
And it's by converting so much energy from one form to another
小猫
3.3焦耳/秒
生命才能保持足够的有序
that life is able to hang on to a tiny amount of order for itself.
刚好抵御无法避免的宇宙衰败
Just enough to resist the inevitable decay of the universe.
所以生物具有热能
So it's no accident that living things are hot
物理教授
82.4焦耳每秒
并向周围散热 绝非偶然
and export heat to their surroundings.
因为这是生存的重要一部分
Because it's an essential part of being alive.
生物从茫茫宇宙中借得秩序
Living things borrow order from the wider universe,
又以无序的形式释放出来
and then they export it again as disorder.
但两者并非平衡
But it's not precisely in balance.
生物释放的无序能量
They have to export more disorder
要比吸收的有序能量多
than the amount of order they import.
这是热力学第二定律的内容
That is the content of the Second Law Of Thermodynamics.
生物必须遵循第二定律
And living things have to obey the Second Law
因为它们也是物理结构
because they're physical structures,
遵循物理学定律
they obey the laws of physics.
仅仅活着
Just by being alive,
我们就参与到 推动宇宙演变
we too are part of the process of energy transformation
的能量转化之中
that drives the evolution of the universe.
我们吸收自古就有的太阳光
We take sunlight that has its origins at the very start of time,
将其转化为永不消散的热能
and transform it into heat that will last for eternity.
所以这绝非一个悖论
So, far from being a paradox,
生物能由物理学定律解释
living things can be explained by the laws of physics.
那些同样解释
The very same laws that describe
落雨与星光的物理学定律
the falling of the rain and the shining of the stars.
蜻蜓通过质子梯度获能
The dragonfly draws its energy from proton gradients,
这个赋予生命的化学变化
the fundamental chemistry that powers life.
但真正的奇迹
But the real miracles
是它们利用这些能量所形成的结构
are the structures they build with that energy.
借用秩序形成细胞
Borrowing order to generate cells,
将细胞排布成组织
arranging those cells into tissues,
再利用组织
and those tissues
形成它们复杂的身体结构
into the intricate architecture of their bodies.
我们已经细致了解了
So we've developed a quite detailed understanding
为蜻蜓供能的潜藏机制
of the underlying machinery that powers these dragonflies,
地球上其他生物亦是如此
and indeed all life on Earth.
虽然我们不知道全部答案
And whilst we don't have all the answers,
但可以放心地说
it is certainly safe to say
这个过程并非需要神奇因素
that there's no mysticism required.
你不用施展什么法术
You don't need some kind of magical flame
让这些小机器运作
to animate these little machines.
它们依照物理定律运行
They operate according to the laws of physics,
但是同样非常神奇
and I think they're no less magical for that.
可是蜻蜓也不会永远
Yet the dragonfly will only maintain
精妙地维持平衡
this delicate balancing act for so long.
因为所有生物都有相同的命运
Because all living things share the same fate.
树
大于4844年
人类
小于122年
每个个体都难逃一死
Each individual will die.
但生命本身会延续
But life itself endures.
因为有一样东西使生命
This is because there's something that separates life
不同于宇宙中的任何过程
from every other process in the universe.
这里是马来西亚的沙巴州
This is the Malaysian state of Sabah,
位于婆罗洲岛的北端
on the northern tip of the island of Borneo.
是地球上物种最丰富的地方
It's one of the most bio-diverse places on the planet.
这里有一万五千种植物...
Home to 15,000 plant species...
三千种树...
3,000 species of tree...
420种鸟类...
420 species of bird...
以及222种哺乳动物
And 222 species of mammals.
包括那些大象
Including those.
婆罗洲的雨林里拥有
Borneo's rainforests contain trees that are thought to live
已存活千余年的树木
for more than 1,000 years.
但这片森林已经存在了数千万年
But the forest itself has existed for tens of millions of years.
它之所以存活至今
The reason it persists is
是因为每一代动植物
because each generation of animal and plant
都会将重塑自己的信息
passes the information to recreate itself
传递给下一代
on to the next generation.
这之所以可能
And that's possible
是因为所有生物细胞中都存在一种分子
because of a molecule found in every cell of every living thing.
DNA分子
A molecule called DNA.
要想分离出我的DNA
Now, all I need to isolate my DNA
只需一些洗涤剂 一点盐
is some washing up liquid, a bit of salt,
以及化学家的挚爱 伏特加
and the chemist's best friend, Vodka.
若想得到DNA样品
Now, to get a sample of DNA
我自己就能提供材料
I can just use myself.
如果用舌头在脸颊内侧打转
If I just swill my tongue around on the edge of my cheek,
就能将一些口腔上皮细胞剥离到唾液中
I'll dislodge some cheek cells into my saliva.
竟然没吐进去
I missed the test tube.
毕竟是一个物理学家在做实验
There we are. A physicist doing an experiment.
然后加一点洗涤剂
Then I add a bit of washing up liquid.
这样就会使
Now, what this will do
口腔上皮细胞破裂
is it will break open those cheek cells
同时还能破坏
and it will also degrade the membrane that surrounds
包裹着DNA的核膜
the cell nucleus that contains the DNA.
盐会使DNA分子聚集
Salt will encourage the molecules to clump together.
而DNA不溶于酒精
DNA is insoluble in alcohol.
所以应该会得到
So you should get a layer of alcohol
析出DNA分子的酒精层
with DNA molecules precipitated out.
这里 看见了吗
There, can you see?
一缕缕白色的物体
Those strands of white.
在那模糊不清 看似无用的固体中
And so in that cloudy, almost innocuous looking solid
蕴藏着构成人类
are all the instructions needed
所需的全部指令
to build a human being.
它让生命独一无二
So that is what makes life unique.
只有生物能通过这种方式
Only living things have the ability to encode
编码和传递信息
and transmit information in this way.
这深刻地影响了
And the consequences of that profoundly
我们对 "何为活着"的认知
affect our understanding of what it is to be alive.
这片雨林是西必洛森林保护区的一部分
This rainforest is part of the Sepilok Forest Reserve,
在雨林中的某处
and in here somewhere
有我们遗传上的近亲
are some of our closest genetic relatives.
在那里 看到了吗
There, there, can you see?
婆罗洲猩猩
猩猩科
红毛猩猩非常适合
Orang-utans are highly specialised
在树冠上生活
for a life lived in the forest canopy.
它们的臂长是腿长的两倍
Their arms are twice as long as their legs.
四肢非常灵活