Where does gold come from? - David Lunney

譯者: Miao Aly 審譯者: Shih Hsiung Chao

中世紀時期

In medieval times,

alchemists tried to achieve the seemingly impossible.

煉金術士進行了一項空前的實驗

They wanted to transform lowly lead into gleaming gold.

他們想讓低鉛變成金燦燦的黃金

History portrays these people as aged eccentrics,

歷史稱這些人為「老古怪」

but if only they'd known that their dreams were actually achievable.

只怪他們身不逢時吧

Indeed, today we can manufacture gold on Earth

因為現在在地球上煉金已不是夢想

thanks to modern inventions

這還要多虧現代的發明

that those medieval alchemists missed by a few centuries.

這對以前的術士來說可是天方夜譚

But to understand how this precious metal

不過想了解此貴金屬

became embedded in our planet to start with,

是怎麼出現在地球上的

we have to gaze upwards at the stars.

我們還得仰望星空尋求答案

Gold is extraterrestrial.

黃金是外來物質

Instead of arising from the planet's rocky crust,

它並非來自岩石地殼

it was actually cooked up in space

而是來自太空

and is present on Earth because of cataclysmic stellar explosions

隨著恆星大爆炸飛來了地球

called supernovae.

這種大爆炸的恆星叫作超新星

Stars are mostly made up of hydrogen, the simplest and lightest element.

恆星主要由最簡單最輕的氫元素組成

The enormous gravitational pressure of so much material

眾多物質產生的巨大重力

compresses and triggers nuclear fusion in the star's core.

會壓縮並引起星核的核聚變

This process releases energy from the hydrogen,

這過程氫會釋能

making the star shine.

使星星更明亮

Over many millions of years,

數百萬年以來

fusion transforms hydrogen into heavier elements:

聚變反應將氫轉變成更大質量的元素

helium, carbon, and oxygen,

例如氦、碳、和氧

burning subsequent elements faster and faster to reach iron and nickel.

並在高溫下快速結合氫，生成鐵和鎳

However, at that point nuclear fusion no longer releases enough energy,

但這時核聚變不再釋放能量

and the pressure from the core peters out.

核心壓力逐漸消失

The outer layers collapse into the center,

外層向核心迅速收縮

and bouncing back from this sudden injection of energy,

核心因突然有能量注入而出現了反彈

the star explodes forming a supernova.

最終星體爆炸，形成了超新星

The extreme pressure of a collapsing star is so high,

坍縮星產生的壓力極大

that subatomic protons and electrons are forced together in the core,

使得亞原子質子和電子在核心聚集

forming neutrons.

形成中子

Neutrons have no repelling electric charge

由於中子不產生電荷排斥

so they're easily captured by the iron group elements.

因此很容易被鐵族元素捕獲

Multiple neutron captures enable the formation of heavier elements

積聚成更大質量的元素

that a star under normal circumstances can't form,

這在正常情況下是不可能形成的

from silver to gold,

元素從銀變成金

past lead and on to uranium.

從鉛變成鈾

In extreme contrast to the million year transformation of hydrogen to helium,

相較于氫變成氦所經歷的百萬年

the creation of the heaviest elements in a supernova

超新星中最重元素的形成過程

takes place in only seconds.

只需幾秒

But what becomes of the gold after the explosion?

那爆炸後是什麼變成了黃金呢

The expanding supernova shockwave propels its elemental debris

持續擴大的超新星產生衝擊波

through the interstellar medium,

推動元素碎片，四散在星際介質中

triggering a swirling dance of gas and dust

引起氣體和塵埃的流動漩渦

that condenses into new stars and planets.

最終壓縮成新恆星和行星

Earth's gold was likely delivered this way

地球上的黃金可能就是這樣而來的

before being kneaded into veins by geothermal activity.

最初，地熱活動將黃金擠壓分散在地脈中

Billions of years later, we now extract this precious product by mining it,

數十幾億年後，採礦技術才讓它重見光明

an expensive process that's compounded by gold's rarity.

由於黃金的稀有性，採礦過程十分昂貴

In fact, all of the gold that we've mined in history

事實上，人類至今開採的黃金

could be piled into just three Olympic-size swimming pools,

只能填滿三個奧運大小的游泳池

although this represents a lot of mass

即使真能填滿，這些黃金的總質量極大

because gold is about 20 times denser than water.

因為黃金的密度是水的20倍

So, can we produce more of this coveted commodity?

這種夢寐以求的商品是否可以人工製造？

Actually, yes.

其實是可以的

Using particle accelerators, we can mimic the complex nuclear reactions

通過粒子加速器，我們可以模擬複雜的核反應

that create gold in stars.

這和在恆星中產生黃金一樣

But these machines can only construct gold atom by atom.

但這些機器只能用逐顆原子來製成黃金

So it would take almost the age of the universe to produce one gram

製造一克黃金就要花近5千9百萬年

at a cost vastly exceeding the current value of gold.

大大超出了現有黃金的價值

So that's not a very good solution.

所以這並非良策

But if we were to reach a hypothetical point

但如果我們做個假設

where we'd mined all of the Earth's buried gold,

地球上所有的黃金已開採殆盡

there are other places we could look.

那還有哪些地方值得我們深究呢

The ocean holds an estimated 20 million tons of dissolved gold

海洋估計有2千萬噸溶解黃金

but at extremely miniscule concentrations making its recovery too costly at present.

但因為其濃度太低，目前想製成黃金代價大

Perhaps one day, we'll see gold rushes to tap the mineral wealth

也許有一天，挖掘礦產資源的淘金熱

of the other planets of our solar system.

會出現在太陽系其他的星球上

And who knows?

誰又知道呢？

Maybe some future supernova will occur close enough

搞不好哪天會有個超新星出現

to shower us with its treasure

向地球展示其財富

and hopefully not eradicate all life on Earth in the process.

希望這過程不會毀滅地球