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金子从哪来

Where does gold come from? - David Lunney

中世纪 炼金术士试图做到看起来不可能的事情
In medieval times, alchemists tried to achievethe seemingly impossible.
他们想把低贱的铅转变为闪闪发光的金子
They wanted to transform lowly leadinto gleaming gold.
历史上把这些人称为古老的异人
History portrays these peopleas aged eccentrics,
但如果他们知道自己的梦想实际上可以实现就好了
but if only they’d known that theirdreams were actually achievable. Indeed,
实际上 我们今天能从地球上提取出金子
today we canmanufacture gold on Earth
多亏了那些几个世纪前中世纪炼金术士未曾发现的当代发明
thanks to modern inventions that those medieval alchemists missed by a few centuries.
但要了解我们地球上的贵金属
But to understand how this precious metal became embedded
是怎么来的
in our planet to start with,
我们必须要抬头凝视恒星来寻求答案了
we have to gaze upwards at the stars.
金子来自外太空
Gold is extraterrestrial.
它们并非来自于地球坚硬的地壳
Instead of arisingfrom the planet’s rocky crust,
而是分散在宇宙中
it was actually cooked up in space
出现在地球上 是由于被称为超新星的
and is present on Earthbecause of cataclysmic stellar explosions
灾难性的恒星大爆炸(引起的)
called supernovae.
大部分恒星是由最简单 最轻的氢元素组成的
Stars are mostly made up of hydrogen, the simplest and lightest element.
这种材料的巨大的重力压力
The enormous gravitational pressureof so much material
向内压缩 在恒星的内核中引起核聚变
compresses and triggers nuclear fusionin the star’s core.
这个过程将施放氢里面的能量
This process releases energyfrom the hydrogen,
使恒星发光
making the star shine.
几百万年来 核聚变将氢转变为重元素:氦
Over many millions of years, fusion transforms hydrogeninto heavier elements: helium,
碳 以及氧
carbon, and oxygen,
越来越快地燃烧随后产生的元素 最终成为铁和镍
burning subsequent elements fasterand faster to reach iron and nickel. However,
在那时 核聚变无法释放充足的能量
at that point nuclear fusionno longer releases enough energy,
来自核心的压力逐渐消失
and the pressure from the core peters out.
外层向中心坍塌
The outer layers collapse into the center,
然后再从突然间的能量注入中 反弹出去
and bouncing back from this suddeninjection of energy,
恒星爆炸 成为超新星
the star explodes forming a supernova.
塌陷的恒星所释放出的压力如此巨大
The extreme pressureof a collapsing star is so high,
以至于原子内的质子和电子在内核中汇聚一起
that subatomic protons and electronsare forced together in the core,
形成中子
forming neutrons.
中子没有电荷
Neutrons have no repelling electric charge
所以 它们可以很轻易地被铁元素吸收
so they’re easily capturedby the iron group elements.
大量的中子吸收使重元素的形成成为可能
Multiple neutron captures enablethe formation of heavier elements
而这个是恒星在正常情况下不能完成的
that a star undernormal circumstances can’t form,
从银转变为金 再变为铅 再变为铀
from silver to gold, past lead and on to uranium.
与几百万年的氢变为氦的过程
In extreme contrast to the million year transformation
形成强烈对比的是
of hydrogen to helium,
超新星中的最重元素形成
the creation of the heaviestelements in a supernova
发生在几秒钟内
takes place in only seconds.
但是 爆炸后 什么变成了金子呢
But what becomes of the goldafter the explosion?
扩张的超新星冲击波促使它主要的残片
The expanding supernova shockwavepropels its elemental debris
扩散到星际介质中
through the interstellar medium,
这引起了气体和灰尘的旋转
triggering a swirling danceof gas and dust
使其形成新的恒星和行星
that condenses into new stars and planets.
地球上的金子可能就是
Earth’s gold was likely delivered this way
地热活动将其融入岩层前 通过这个方式释放出的
before being kneaded into veinsby geothermal activity.
几十亿年之后
Billions of years later,
现在 我们通过“采掘” 这项花费巨大 伴随发现金子的微小可能的程序
we now extract this precious product by mining it,
来提取这种稀有矿产
an expensive process that’s compoundedby gold’s rarity.
实际上 历史上我们采掘的所有金子
In fact, all of the goldthat we’ve mined in history
堆叠起来 大概有三个奥林匹克比赛游泳池的大小
could be piled intojust three Olympic-size swimming pools,
尽管它们的质量很大
although this represents a lot of mass
因为金子的密度是水的20倍 所以
because gold is about 20 timesdenser than water. So,
我们能产出更多这种宝贵的产品吗?
can we produce moreof this coveted commodity?
实际上 是可以的
Actually,yes.
通过使用粒子加速器 我们可以模拟出恒星产生金子的
Using particle accelerators, we can mimicthe complex nuclear reactions
复杂的核反应
that create gold in stars.
但是这些机器只能一个原子一个原子的形成金子
But these machines can only construct goldatom by atom.
所以 大概需要
So it would take almost the age
宇宙的寿命那么长的时间才可以产出
of the universe to produce one gram
一克金子 成本比当下的金子贵多了
at a cost vastly exceedingthe current value of gold.
所以这不是一个好的方法
So that’s not a very good solution.
但是 如果我们猜想下
But if we were to reacha hypothetical point
即使我们挖光了陆地上所有的金子
where we’d minedall of the Earth’s buried gold,
我们还可以发掘其它的地方
there are other places we could look.
海洋 据统计 大概有2000万吨的溶解的金子
The ocean holds an estimated20 million tons of dissolved gold
但是目前来讲 极为分散的金子分布使它的成型花费很大
but at extremely miniscule concentrations making its recovery too costly at present.
也许有一天
Perhaps one day,
我们会在太阳系的其他星球上
we’ll see gold rushes to tap the mineral wealth
看到淘金热
of the other planets of our solar system.
谁知道呢?
And who knows?
也许 未来的超新星会距离我们足够近
Maybe some future supernovawill occur close enough
可以让我们分享它的财富
to shower us with its treasure and hopefully
同时 也希望 这不会影响到地球上的生命
not eradicate all life on Earth in the process.

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视频概述

地球上的金子到底从哪里来的呢

听录译者

收集自网络

翻译译者

lala

审核员

审核员 V

视频来源

https://www.youtube.com/watch?v=jf_4z4AKwJg

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