生命的奇迹（2013）

是由于水
which is the energy it possesses
高于地球表面而存在的能量
due to its height above the Earth's surface.
如果我从河里舀点水到这个烧杯中
See, if I scoop some water out of the river into this beaker,
我需要做功
then I'd have to do work
才能将它带到瀑布顶端
to carry it up to the top of the waterfall.
我需要消耗能量才能把它带上去
I'd have to expend energy to get it up there.
于是消耗的能量会转化成水的重力势能
So it would have that energy as gravitational potential.
我甚至能为你计算一下
I can even do the sums for you.
半升水是半千克重
Half a litre of water has a mass of half a kilogram,
乘以高度 差不多有五米
multiply by the height, that's about five metres,
重力加速度
the acceleration due to gravity's
大约是十米每平方秒
about ten metres per second squared.
0.5乘5乘10等于25焦耳
So that's half times five times ten is 25 joules.
我得做25焦耳的功
So I'd have to put in 25 joules
才能将这杯水带到瀑布顶端
to carry this water to the top of the waterfall.
如果我在瀑布顶端将它倒出
Then if I emptied it over the top of the waterfall,
重力势能将会全部
then all that gravitational potential energy
转化为其他形式的能量
would be transformed into other types of energy.
水流声是空气中的压力波
Its sound, which is pressure waves in the air.
河水里的浪花也具有能量
There's the energy of the waves in the river.
还有就是热能
And there's heat.
所以底下的河水会热一些
So it'll be a bit hotter down there
因为水倾泻到
because the water's cascading into the pool
瀑布下面的水潭中
at the foot of the waterfall.
但关键在于能量是守恒的
But the key thing is energy is conserved,
不会凭空出现或消失
it's not created or destroyed.
正是因为能量守恒
So, because energy is conserved,
如果我把水波中的所有能量
if I were to add up all the energy in the water waves,
声波中的所有能量
all the energy in the sound waves,
和池底的所有热能加起来
all the heat energy at the bottom of the pool,
就会发现能量总值正好等于
then I would find that it would be precisely equal
水在瀑布顶端具有的重力势能
to the gravitational potential energy at the top of the falls.
由瀑布得出的结论
What's true for the waterfall
同样适用于宇宙万物
is true for everything in the universe.
这是自然界的基本定律
It's a fundamental law of nature,
也就是热力学第一定律
known as the first law of thermodynamics.
能量既不会凭空产生 也不会凭空消失
And the fact that energy is neither created nor destroyed
有着深远的含义
has a profound implication.
那就是能量是永恒的
It means energy is eternal.
此时此刻的能量一直就存在
The energy that's here now has always been here,
宇宙的演变进化
and the story of the evolution of the universe
只不过是能量由一种形式
is just the story of the transformation of that energy
转化为另一种的过程
from one form to another,
从第一批出现的星系
from the origin of the first galaxies
到第一批发光的恒星
to the ignition of the first stars
和第一批形成的行星
and the formation of the first planets.
如今宇宙中每焦耳的能量
Every single joule of energy in the universe today
在137亿年前的大爆♥炸♥时已然存在
was present at the Big Bang 13.7 billion years ago.
原始气体云和尘埃的势能
Potential energy held in primordial clouds of gas and dust
在坍缩形成恒星和行星系统时
was transformed into kinetic energy
转化成了动能
as they collapsed to form stars and planetary systems,
正如我们的太阳系
just like our own solar system.
在太阳内部
In the Sun,
坍缩产生的热能在太阳的核心引发核聚变
heat from the collapse initiated fusion reactions at its core.
氢原子变为氦原子
Hydrogen became helium.
原子核聚变释放能量
Nuclear-binding energy was released,
加热了太阳的表面
heating the surface of the Sun,
产生了阳光
producing the light
开始哺育年幼的地球
that began to bathe the young Earth.
这个过程中的某一时刻 大约40亿年前
And at some point in that story, around four billion years ago,
地球因为能量的转化出现了生命
that transformation of energy led to the origin of life on Earth.
萨加达向南约350公里
Around 350 kilometres south of Sagada,
有个塔尔湖
this is Lake Taal.
在宁静的湖水之下
Despite its sleepy, languid appearance,
隐藏着被能量改造的地貌
this landscape has been violently transformed by energy.
我想象中的火山
When I think of a volcano,
通常是尖尖的 火红的山
I usually think of a pointy, fiery mountain
顶上有个小火山口
with a little crater in the top.
可能有点像那个
Probably a bit like that one.
但事实上整个湖
But actually this entire lake
是巨型火山口上形成的积水湖
is the flooded crater of a giant volcano.
14万年前它刚开始喷发
It began erupting only about 140,000 years ago,
在那时
and in that time
它喷出了1200亿立方米的尘埃和岩石
it's blown 120 billion cubic metres of ash and rock
进入到地球大气层
into the Earth's atmosphere.
这个火山口直径有30公里
This crater is 30 kilometres across
有几处深达150米
and in places 150 metres deep.
一大块岩石
That's a cube of rock
长宽高都是五千米
five kilometres by five kilometres by five kilometres
就被这么喷了出去
just blown away.
真是座大火山
It's a big volcano.
塔尔湖证明了地球形成时
Taal Lake is testament to the immense power
蕴含着巨大能量
locked within the Earth at the time of its formation.
自湖形成伊始
Since the lake was created,
一连串的喷发形成了湖中小岛
a series of further eruptions formed the island in the centre.
在其中心
And at its heart
你能瞥见地球内部的骚动
is a place where you can glimpse the turmoil of the inner Earth,
地核中的能量 在水面上形成气泡
where energy from the core still bubbles up to the surface...
营造与生命诞生时
Producing conditions similar to those
类似的自然条件
that may have provided the very first spark of life.
这里的湖水不同于饮用水
The water in this lake is different from drinking water
它们的不同点非常有趣
in a very interesting way.
看 如果我用这个通用试纸
See, if I test this bottle of water with this,
测试一下这瓶水
which is called universal indicator paper,
你可以立刻看到它变成了绿色
then you see immediately that it goes green.
就是说这个水完全是中性的
And that means that it's completely neutral.
用行话说就是PH值为7
It's called PH7 in the jargon.
再看看我测湖水会怎么样
But then look what happens when I test the water from the lake.
试纸仍然是橙色的
Now the indicator paper stays orange.
事实上 橙色好像变得更深些
In fact, it might have gone a bit more orange.
这就表示水呈酸性 PH值大约为3
So that means that this is acid. It's about PH3.
在水的最底层
At the most basic level,
被束缚在地球内部的能量正在熔化岩石
the energy trapped inside the Earth is melting rocks.
要熔化这样的岩石会释放出气体
And when you melt rock like this you produce gases.
会有很多二氧化碳
A lot of carbon dioxide,
而这座火山里 会释放许多二氧化硫
and in this case of this volcano, a lot of sulphur dioxide.
二氧化硫
二氧化硫溶入水中
Now, sulphur dioxide dissolves in water
二氧化硫
水
硫
酸
就得到了H2SO4 硫酸
and you get H2SO4, sulphuric acid.
我说水呈酸性是什么意思呢
Now, what I mean when I say that water is acidic?
水的分子式是H2O 氢氧原子结合在一起
Well, water is H2O - hydrogen and oxygen bonded together.
但其实当水是液态时
But actually when it's liquid
情况更复杂一些
it's a bit more complicated than that.
它由大量的离子构成
It's actually a sea of ions.
氢正离子 就是一个单独的质子
So H-plus ions, that's just single protons.
氢氧负离子 氢氧原子的结合
And OH-minus ions, that's oxygen and hydrogen bonded together,
漂浮在水中
all floating around.
如果是中性 PH值为7
Now, when something's neutral, when the PH is seven,
就表示这些离子的浓度
that means that the concentrations of those ions
完全相等
are perfectly balanced.
当水呈酸性
When you make water acidic,
这些离子的浓度发生改变
then you change the concentration of those ions
具体来说
and, to be specific,
氢正离子 即质子的浓度增加
you increase the concentration of the H-plus ions of the protons.
所以说酸化的过程
So, this process of acidification
将火山的能量
has stored the energy of the volcano
转化成了化学能
as chemical potential energy.
火山把地球内部的热能
The volcano transforms heat from the inner Earth
转化为化学能