宇宙的奇迹（2011）

are marked by unique milestones.
都伴随着独一无二的里程碑
The births and deaths of its wonders.
奇迹一个个诞生 一个个消亡
The moment the first stars were born
第一颗恒星的诞生
is one of the most important changes in the evolution of the cosmos.
是宇宙进化中最重要的变化之一
It signals the end of the Primordial Era
它标志着"原初时代"的结束
and marks the beginning of the second great age of the universe.
也标志着宇宙第二个重要时期的开始
The time in which we live.
也就是我们现今生活的时期
The Stelliferous Era -
"生星时代"
the age of the stars.
恒星漫天的时代
Starlight illuminates the night sky
星光照亮了夜空
and starlight illuminates our days.
也照亮了我们的生活
Our sun is just one of 200 billion stars in our galaxy.
我们的太阳只是银河系两千亿颗恒星中的一颗
Our galaxy is one of 100 billion
我们的星系也只是可观察的宇宙范围内的
in the observable universe.
一百亿个星系中的一个
And countless islands of countless stars.
数不尽的星球上有数不胜数的岛屿
Although the universe is over 13 billion years old,
尽管宇宙的年龄超过了一百三十亿岁
we still live close to the stars of the Stelliferous Era.
我们周围的恒星还是处于"生星时代"
It's an age of astonishing beauty and complexity in the universe.
这是宇宙中壮美而复杂的一个时期
The cosmos is absolutely awash with stars
宇宙中到处都是
surrounded by nebulae and systems of planets.
被星云和行星系统包围的恒星
Countless billions of worlds that we've yet to explore.
我们未曾探索的世界不计其数
But the cosmos isn't static and unchanging.
然而宇宙并不是一成不变的
It won't always be this way.
它不会永远保持这样
Because, as the arrow of time plays out,
因为 由于时间箭头的作用
it produces a universe that is as dynamic as it's beautiful.
它产生出一个动态与美丽并存的宇宙
We've seen stars born and we've seen stars die.
我们观测到了无数恒星诞生 灭亡
And we know that tomorrow won't be the same as today
我们也知道明天不会与今天一样
because the arrow of time says
因为时间箭头告诉我们
the future will always be different from the past.
未来总是与过去有所不同
But what drives this evolution?
但是什么促使宇宙进化呢
Why is there a difference between the past and the future?
为什么过去和未来会存在不同
Why is there an arrow of time at all?
又为什么会存在时间箭头呢
We all have an intuitive understanding of the arrow of time.
我们都对时间箭头有种直观的理解
It seems obvious to us that things change
显然万物都在变化
and the future will be different to the past.
未来将与过去不同
We know that
我们知道这一点
because we see the effects of the passing years all around us.
因为我们目睹了年复一年的变化
This is Kolmanskop,
这里是卡曼斯科
an abandoned diamond mining town in southern Namibia.
纳♥米♥比♥亚♥南部一座废弃的钻石矿城
This entire town was founded in 1908,
整座小城建立于1908年
when a worker who was building the railway
当时 从吕德里茨港口
from the port of Luderitz inland into the centre of Namibia
到纳♥米♥比♥亚♥中部的铁路正在兴建之中
found a single diamond here in this desert.
一位修路工在这片沙漠里找到了一颗钻石
For 40 years,
在之后的四十年里
this was a thriving community of up to 1,000 people.
这里曾经是一个多达千人的繁荣社区
A place where you could become a millionaire,
从沙里淘到钻石
picking diamonds out of the sand.
你就能成为百万富翁
While the money rolled in, they built grand houses
随着金钱涌入 他们在沙漠之中建起了豪♥宅♥
and lived a champagne lifestyle in the desert.
过上了灯红酒绿的生活
But when the diamonds dried up, the town was abandoned.
但当钻石枯竭时 这座城镇被废弃了
And for half a century it's fallen
半个世纪后 随着黄沙慢慢侵蚀
into disrepair as it's slowly reclaimed by the sands.
它变成了如今的断壁残垣
The processes at play here at Kolmanskop
宇宙中无时无刻都在上演着
are happening everywhere in the universe.
卡曼斯科闹剧
Because it isn't simply permanent change
因为这并不仅是时间箭头的核心思想
that's central to the arrow of time.
所阐述的永恒变化
It's decay.
更是一种衰退
But the scientific explanation for why that is
但对此作出的科学解释
didn't come from attempting to understand the effects of time in the universe.
并非源于试图去了解宇宙中时间的影响
It came from trying to build a faster train.
而是源于试图建造更快的火车
Back in the 19th century,
早在十九世纪
engineers were concerned with the efficiency of steam engines.
工程师们就很关注蒸汽机的效率问题
How hot should the fire be?
火要达到多热
What substance should you boil in the steam engine?
蒸汽机引擎中要加入何种沸腾物质
Should it be water or something else?
是水还是其他东西
These were profound questions.
这都是些深奥的问题
And out of those questions arose the science of thermodynamics.
为解答这些问题 热力学诞生了
It's when concepts like heat and temperature and energy
与此同时 热量 温度 能量等概念
entered the scientific vocabulary for the first time.
首次进入科学词典
Now, along with that deeper understanding
现在 随着我们了解的深入
emerged what is probably the most important law of physics
为理解宇宙进化和时间流逝
for understanding the evolution of the universe and the passage of time.
一条可能是最重要的物理定律应运而生
It's called the Second Law of Thermodynamics.
这便是"热力学第二定律"
The reason the Second Law of Thermodynamics was so profound
"热力学第二定律"之所以深奥
was because, at its heart, it contained a radically new concept.
是因为其核心内容包括了一个完全新鲜的概念
Something physicists call "entropy".
即物理学家们所说的"熵"
Entropy explains why, left to the mercy of the elements,
熵在元素的角度解释了
mortar crumbles, glass shatters and buildings collapse.
砂浆粉碎 玻璃破碎以及房♥屋倒塌的原因
And a good way to understand
也合理解释了
how is to think of objects not as single things,
为何不将物体看作单一的个体
but as being made up of many constituent parts.
而是看作许多成分的组合体
Like the individual grains that make up this pile of sand.
就像一颗颗沙粒堆成了这个沙堆
Now, entropy is a measure of how many ways I can rearrange those grains
熵可以测量出在保持沙堆不变的情况下
and still keep the sand pile the same.
我能有多少种方式重新排列沙粒
And there are trillions and
结果发现
trillions and trillions of ways of doing that.
有数万亿种方式
I mean, pretty much anything I do to this sand pile,
我可以把沙堆堆成许多东西
if I mess the sand around and move it around,
就算我把沙子弄乱 混到四周
then it doesn't change the shape or the structure at all.
也完全不会改变它的形状或结构
So, in the language of entropy,
因而 从熵的意义上说
this sand pile has high entropy
这块沙堆的熵值很高
because there are many, many ways that I can rearrange its constituents
我们可以随意重列它的成分
and not change it.
但不引起变化
Now let me create some order in the universe.
现在我来创造些宇宙的规则吧
Now, there are approximately
这个沙堡里的沙粒
as many sand grains in this sandcastle as there are in the sand pile.
应该跟沙桩里的一样多
But now, virtually anything I do to it will mess it up,
但你看 我随便弄就能把它弄乱
will remove the beautiful order from this structure.
都能让它失去井然有序的外表结构
And because of that, the sandcastle has a low entropy.
因此 这个沙堡的熵值很低
It's a much more ordered state.
它是一个更为有序的状态
So many ways of rearranging the sand grains
因此 能随意排列沙粒
without changing the structure, high entropy.
而结构不会改变的 高熵值
Very few ways of rearranging the sand grains
而不改变结构
without changing the structure,
不改变它的有序状态
without disordering it, low entropy.
重列方式很少的 低熵值
Imagine I was to leave this castle in the desert all day.
想象下如果我把沙堡丢在沙漠里一天
Then it's obvious what's going to happen.
会发生的事显而易见
The desert winds are going to blow the sand around
沙漠的风会吹得狂沙乱舞
and this castle is going to disintegrate.
这个小城♥堡♥也将瓦解
Is going to become less ordered. Is going to fall to bits.
它会变得更无序 继而坍塌
But think about what's happening on the fundamental level.
但从基本原理上想想究竟发生了什么
I mean, the wind is taking the sand off the castle
风把沙粒从城♥堡♥上吹走
and blowing it over there somewhere and making a sand pile.
吹向四处 落到别处形成沙堆
There's nothing fundamental in the laws of physics that says
物理定律里没有哪条原理显示
that the wind couldn't pick up some sand from over here,
风不能从某处带走沙粒
deposit it here
再放到另一处
and deposit it in precisely the shape of a sandcastle.
再精确地按照沙堡的形状摆放
In principle, the wind could
原则上来说
spontaneously build a sandcastle out of a pile of sand.
风可以用一堆沙建起一座沙堡
There's no reason why that couldn't happen.
没有理由解释为什么不能发生
It's just extremely, extremely unlikely
但它就是绝对绝对不可能发生
because there are very few ways of organising this sand
因为只有几种排列方式
so that it looks like a castle.
能让这些沙看起来像一座城♥堡♥
It's overwhelmingly more likely
然而另一种可能性却不可避免
that when the wind blows the sand around
风吹起沙粒时
it will take the low entropy structure of the castle
能改变城♥堡♥这种低熵值的结构
and turn it into a high entropy structure, the sand pile.
把它变成一种高熵值的结构 沙堆
So, entropy always increases. Why is that?
熵值总是在增大 这是为什么
Because it's overwhelmingly more likely that it will.
因为一种不可抗的可能性促使的
It seems incredible that a law that says
迎着风不能自发形成沙堡