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  • We know about our universe's past:

    我們知道宇宙的過去:

  • the Big Bang theory predicts that all matter, time, and space

    根據大爆炸理論的預測, 所有的物質、時間、空間

  • began in an incredibly tiny, compact state about 14 billion years ago.

    都開始於一個極小、 極緊實的狀態,時間是大約一百四十億年前。

  • And we know about the present:

    我們也知道現在:

  • scientists' observations of the movement of galaxies

    根據科學家對於銀河運動的觀察,

  • tell us that the universe is expanding at an accelerated rate.

    宇宙正在擴張,且速度越來越快。

  • But what about the future?

    但,未來呢?

  • Do we know how our universe is going to end?

    我們是否知道宇宙會如何結束?

  • Cosmologists have three possible answers for this question,

    宇宙學家針對這個問題 有三個可能的答案:

  • called the Big Freeze,

    大凍結、

  • the Big Rip and the Big Crunch.

    大撕裂,和大擠壓。

  • To understand these three scenarios,

    若要了解這三種情境,

  • imagine two objects representing galaxies.

    先想像一下,用兩個物體 來代表兩個銀河。

  • A short, tight rubber band is holding them together

    有一條很短、很緊的橡膠帶 將它們連結在一起——

  • that's the attractive force of gravity.

    那就是重力造成的引力。

  • Meanwhile, two hooks are pulling them apart

    同時,有兩個勾子 在將它們拉開——

  • that's the repulsive force expanding the universe.

    那就是讓宇宙擴張的排斥力。

  • Copy this system over and over again,

    將這個系統不斷複製,

  • and you have something approximating the real universe.

    得到的結果就會 很接近真實的宇宙。

  • The outcome of the battle between these two opposing forces

    這兩種相反力量之間的對抗

  • determines how the end of the universe will play out.

    會決定宇宙最後的結局是什麼。

  • The Big Freeze scenario is what happens if the force pulling the objects apart

    大凍結的情境是預期 將物體拉開的力量

  • is just strong enough to stretch the rubber band until it loses its elasticity.

    強大到足以將橡膠帶延伸開來, 到失去彈性的程度。

  • The expansion wouldn't be able to accelerate anymore,

    此時擴張無法再加速了,

  • but the universe would keep getting bigger.

    但宇宙會持續變得更大。

  • Clusters of galaxies would separate.

    一群一群的銀河會分離開來。

  • The objects within the galaxies

    在銀河中的物體——

  • suns, planets, and solar systems

    太陽、行星,和太陽系,

  • would move away from each other,

    會彼此遠離,

  • until galaxies dissolved into lonely objects

    直到銀河瓦解成單獨的物體,

  • floating separately in the vast space.

    在浩瀚的太空中各自漂浮。

  • The light they emit would be redshifted to long wavelengths

    它們發散的光會發生紅移, 成為長的波長,

  • with very low, faint energies,

    能量則非常低、非常微弱,

  • and the gas emanating from them would be too thin to create new stars.

    它們散發出來的氣體 會太稀薄而無法創造出新星。

  • The universe would become darker and colder,

    宇宙會變得更黑暗、更寒冷,

  • approaching a frozen state

    接近一種冰凍的狀態,

  • also known as the Big Chill,

    也就是所謂的大冰凍,

  • or the Heat Death of the Universe.

    或是宇宙的「熱寂」。

  • But what if the repulsive force is so strong

    但,如果排斥力很強,

  • that it stretches the rubber band past its elastic limit,

    強到讓橡膠帶的延伸 超出它的彈性極限,

  • and actually tears it?

    真的將它撕裂了,會如何?

  • If the expansion of the universe continues to accelerate,

    如果宇宙的擴張持續加速,

  • it will eventually overcome not only the gravitational force

    最後,它不僅會戰勝重力引力——

  • tearing apart galaxies and solar systems

    將銀河和太陽系給扯開——

  • but also the electromagnetic, weak, and strong nuclear forces

    同時也會戰勝電磁的、 弱的、強的核力,

  • which hold atoms and nuclei together.

    也就是讓原子和核子 結合在一起的力量。

  • As a result, the matter that makes up stars breaks into tiny pieces.

    結果就是,形成天體的 物質會破成碎片。

  • Even atoms and subatomic particles will be destroyed.

    就連原子和亞原子粒子 都會被摧毀。

  • That's the Big Rip.

    那就是大撕裂。

  • What about the third scenario,

    那麼,第三個情境,

  • where the rubber band wins out?

    也就是橡膠帶獲勝的情境呢?

  • That corresponds to a possible future

    在這個情境所對應的可能未來,

  • in which the force of gravity brings the universe's expansion to a halt

    重力引力會讓宇宙的 擴張停下來——

  • and then reverses it.

    接著將它逆轉。

  • Galaxies would start rushing towards each other,

    銀河會開始衝向彼此,

  • and as they clumped together

    它們會結成一團,

  • their gravitational pull would get even stronger.

    它們的重力引力就會變得更強。

  • Stars too would hurtle together and collide.

    天體也會衝向彼此並相撞。

  • Temperatures would rise as space would get tighter and tighter.

    隨著空間變得越來越 緊密,溫度會上升。

  • The size of the universe would plummet

    宇宙的大小會極劇縮小,

  • until everything compressed into such a small space

    直到一切都壓縮成 這麼一個小空間,

  • that even atoms and subatomic particles would have to crunch together.

    就連原子和亞原子粒子 也會擠在一起。

  • The result would be an incredibly dense, hot, compact universe

    結果就會造成一個非常高密度、 高溫、緊密的宇宙——

  • a lot like the state that preceded the Big Bang.

    很像是大爆炸之前的狀態。

  • This is the Big Crunch.

    這就是大擠壓。

  • Could this tiny point of matter explode in another Big Bang?

    這個物質小圓點有沒有可能會爆炸, 發生另一次的大爆炸?

  • Could the universe expand and contract over and over again,

    宇宙有沒有可能會擴張又收縮, 一而再,再而三,

  • repeating its entire history?

    不斷重覆它的整段歷史?

  • The theory describing such a universe is known as the Big Bounce.

    描述這種宇宙的理論叫做大反彈。

  • In fact, there's no way to tell how many bounces could've already happened

    事實上,無法知道目前 已經發生過多少次反彈——

  • or how many might happen in the future.

    或是未來還會發生多少次。

  • Each bounce would wipe away any record of the universe's previous history.

    每一次反彈都會將 宇宙的先前歷史紀錄給抹除。

  • Which one of those scenarios will be the real one?

    這些情境中, 哪一個比較可能是真的?

  • The answer depends on the exact shape of the universe,

    答案會依宇宙的形狀而定,

  • the amount of dark energy it holds,

    要看它所保有的暗能量有多少,

  • and changes in its expansion rate.

    以及它擴張速度的改變。

  • As of now, our observations suggest that we're heading for a Big Freeze.

    目前為止,根據我們的觀察, 我們正在朝大冰凍前進。

  • But the good news is that we've probably got about 10 to the 100th power years

    但,好消息是,我們可能 還要等「十的一百次方」年,

  • before the chill sets in

    才會開始感到寒冷——

  • so don't start stocking up on mittens just yet.

    所以,還不用開始儲備長手套啦。

We know about our universe's past:

我們知道宇宙的過去:

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B2 中高級 中文 美國腔 TED-Ed 宇宙 銀河 擴張 情境 引力

TED-ED - 宇宙終結的三種方式 - Venus Keus (TED-ED | Three ways the universe could end - Venus Keus)

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    11101130 發佈於 2021 年 01 月 14 日
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