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  • In medieval times, alchemists tried to achieve the seemingly impossible.

    中世紀時期,煉金術士試圖達成看似不可能的事。

  • They wanted to transform lowly lead into gleaming gold.

    他們想將低等的鉛轉變成閃亮的黃金。

  • History portrays these people as aged eccentrics, but if only they'd known that their dreams were actually achievable.

    歷史將這群人描繪為古怪老人,那是因為他們還不知道這個夢想實際上是可以實現的。

  • Indeed, today we can manufacture gold on Earth, thanks to modern inventions that those medieval alchemists missed by a few centuries.

    沒錯,我們今日能在地球上煉金,而這都多虧了幾世紀前煉金術士錯過的現代發明。

  • But to understand how this precious metal became embedded in our planet to start with, we have to gaze upwards at the stars.

    但要想了解這珍貴的金屬一開始是如何埋入我們的土地中,我們必須抬頭仰望星星。

  • Gold is extraterrestrial.

    黃金來自外太空。

  • Instead of arising from the planet's rocky crust, it was actually cooked up in space, and is present on Earth because of cataclysmic stellar explosions called supernovae.

    它並不是從地球的岩石地殼生成的,而是在大空中誕生,它之所以出現在地球上,歸因於稱為「超新星」的星體劇烈爆炸。

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

    恆星多由氫氣組成,它是最簡單也最輕的元素。

  • The enormous gravitational pressure of so much material compresses and triggers nuclear fusion in the star's core.

    大質量恆星的重力塌陷,在恆星內部集聚而引發核融合。

  • This process releases energy from the hydrogen, making the star shine.

    這個過程會釋放氫元素能量,讓恆星發亮。

  • Over many millions of years, fusion transforms hydrogen into heavier elements: helium, carbon, and oxygen, burning subsequent elements faster and faster, to reach iron and nickel.

    在數百萬年期間,融合反應將氫轉換成更重的元素:氦、碳和氧,逐漸加快燃燒剩餘的元素,直到生成鐵和鎳。

  • However, at that point, nuclear fusion no longer releases enough energy, and the pressure from the core peters out.

    不過,核融合此時已經不再釋放足夠的能量,而核心壓力也逐漸停止。

  • The outer layers collapse into the center, and bouncing back from this sudden injection of energy, the star explodes, forming a supernova.

    恆星外層開始向內塌陷,然後因突然注入的能量而彈回原狀,進而爆炸形成超新星。

  • The extreme pressure of a collapsing star is so high that subatomic protons and electrons are forced together in the core, forming neutrons.

    坍塌中恆星的壓力極大,導致質子與電子被迫在核心合為一體,形成中子。

  • Neutrons have no repelling electric charge, so they're easily captured by the iron group elements.

    中子不帶排斥電荷,所以它們很容易被鐵元素匯集。

  • Multiple neutron captures enable the formation of heavier elements that a star under normal circumstances can't form, from silver to gold, past lead, and on to uranium.

    大量的中子攫取有助更重元素的形成,這是恆星在正常情況下做不到的,由銀到金,轉為過度期的鉛,最後變成鈾。

  • In extreme contrast to the million-year transformation of hydrogen to helium, the creation of the heaviest elements in a supernova takes place in only seconds.

    與氫變氦的百萬年轉變過程大相逕庭,超新星中最重元素的形成,只需要幾秒鐘。

  • But what becomes of the gold after the explosion?

    但爆炸之後,黃金會變成什麼呢?

  • The expanding supernova shockwave propels its elemental debris through the interstellar medium, triggering a swirling dance of gas and dust that condenses into new stars and planets.

    擴大中的超新星震波會使它的元素碎片穿透星際媒介,誘發氣體與塵埃的旋轉舞動,從而濃縮成新的恆星和行星。

  • Earth's gold was likely delivered this way, before being kneaded into veins by geothermal activity.

    在因地熱運動而滲入土裡前,地球上的黃金很可能是這種形式落地的。

  • Billions of years later, we now extract this precious product by mining it, an expensive process that's compounded by gold's rarity.

    數十萬年後的現在,我們得以採礦而獲得這項寶物,由於黃金數量稀少,採金的過程所費不貲。

  • In fact, all of the gold that we've mined in history could be piled into just 3 Olympic-size swimming pools.

    事實上,我們自古至今採過的所有黃金,只能裝滿 3 座奧林匹克游泳池。

  • Although, this represents a lot of mass, because gold is about 20 times denser than water.

    不過,這已經是很大的數量了,因為黃金的密度是水的約 20 倍高。

  • So, can we produce more of this coveted commodity?

    那麼,我們能夠製造更多這樣眾人愛戴的商品嗎?

  • Actually, yes.

    其實可以。

  • Using particle accelerators, we can mimic the complex nuclear reactions that create gold in stars.

    我們可以用粒子加速器模擬恆星創造黃金時的複雜核融合反應。

  • But these machines can only construct gold atom by atom.

    但這些機器只能以單一原子的方式慢慢製造黃金。

  • So it would take almost the age of the universe to produce 1 gram, at a cost vastly exceeding the current value of gold.

    所以需要近乎宇宙壽命等長的時間才能製造 1 公克,成本遠遠超過現在的黃金價值。

  • So that's not a very good solution.

    所以那不是個很好的解答。

  • But if we were to reach a hypothetical point where we'd mined all of the Earth's buried gold, there are other places we could look.

    但假設我們到了採盡地球上所有深埋的黃金,必定還有其他可以開發的地方。

  • The ocean holds an estimated 20 million tons of dissolved gold, but at extremely minuscule concentrations, making its recovery too costly at present.

    海洋含有大約 2 千萬噸溶解的黃金,但由於黃金集聚度極低,目前在海中淘金的代價太高。

  • Perhaps one day, we'll see gold-rushers to tap the mineral wealth of the other planets of our solar system.

    也許有一天,我們會看到淘金客準備前往太陽系其他行星探採這個貴金屬。

  • And who knows?

    誰知道呢?

  • Maybe some future supernova will occur close enough to shower us with its treasure, and hopefully not eradicate all life on Earth in the process.

    也許未來某個超新星會在離我們夠近的地方,讓我們沐浴在它的寶藏之中,同時希望這個過程不會導致地球上所有生命滅絕。

In medieval times, alchemists tried to achieve the seemingly impossible.

中世紀時期,煉金術士試圖達成看似不可能的事。

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B2 中高級 中文 美國腔 TED-Ed 黃金 恆星 元素 新星 地球

【TED-Ed】人人都愛的黃金到底是從何而來? (Where does gold come from? - David Lunney)

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    SylviaQQ 發佈於 2020 年 10 月 30 日
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