Gravity vs. Pressure: The battle that formed the universe - Fabio Pacucci

譯者: Lilian Chiu 審譯者: 穎君 紀

Welcome one and all!

歡迎大家！

It’s time to grab your seat for the biggest battle

各位來賓請就座，一同迎接 即將形成的宇宙中最重大的戰役—

in the soon-to-be-formed universe.

That’s right— the Big Bang is about to go down!

沒錯，宇宙大爆炸即將發生！

In one corner is the force that brings all matter together.

第一位選手是將所有物質 聚集在一起的力量。

It acts on any particle with mass, and its range is infinite—

它對任何有質量的粒子都會產生 作用，且它的範圍無窮盡——

give it up for gravity!

大家給「引力」掌聲鼓勵鼓勵！

In the other corner, our contender can push matter away

接下來這位是我們的挑戰者，

能夠用超凡的力量將物質推開。

with spectacular strength.

When the going gets tough, this fighter just gets tougher.

這位鬥士是越挫越勇的型。

That’s right, it’s pressure!

沒錯，它就是「壓力」！

Over the next several hundred thousand years,

在接下來的數十萬年，

these two contenders will be wrestling for the fate of the universe.

這兩位參賽者將要為宇宙的命運搏鬥。

That’s right folks, the ripple effects of this historic match

你沒有聽錯，這場歷史性對決所產生的餘波

will shape the structure of the universe as we know it today.

將形塑出我們現今所知的宇宙結構。

But what are these powers fighting over?

這兩股力量要爭的是什麼？

We’ll find out when the Big Bang hits right... now!

大爆炸發生時就知道了，就是……

現～～在～～！

Let’s zoom in for the play-by-play.

咱們來近看每個細節吧。

This epic event has brought three components into our infant universe.

這重量級事件把三種物質 引進嬰兒期的宇宙。

Dark matter, which only interacts with gravity.

暗物質：它只會和引力互相作用。

Baryonic matter, which makes up all matter you’ve ever seen,

重子物質：它組成你所見的所有物質，

is affected by both gravity and pressure.

它受引力及壓力影響。

And radiation composed of innumerable particles of light,

還有輻射：由無數個光粒子組成，

also known as photons.

光粒子就是光子。

In the moments just after the Big Bang,

在大爆炸剛發生後，

all three components are in equilibrium,

這三種物質的分佈都在均衡狀態，

meaning no one location is denser than another.

意即，沒有某處的密度 比另一處更高。

But as the universe starts expanding, differences in density start to emerge.

但隨著宇宙開始擴張， 密度逐漸不均。

Gravity immediately gets to work pulling matter together.

引力立刻上工，把物質聚集起來。

Dark matter begins to collect at the center

暗物質開始聚集在密度 逐漸升高的區域，

of these increasingly dense regions,

forming the foundations of future galaxies.

形成未來銀河的基石。

Meanwhile, pressure begins gathering its strength.

同時，壓力開始匯集它的力量，

In this hot, high-energy environment,

在高溫高能量的環境中，

protons and electrons can’t come together to form atoms,

光子和電子無法結合形成原子，

so these loose particles zip around, freely interacting with ambient photons.

所以這些不受牽制的粒子到處亂竄，

和周圍的光子自由地交互作用，

The result is almost a fluid of baryonic matter and radiation.

產出接近液狀的重子物質和輻射。

But the closer these baryonic particles get, the hotter the fluid becomes,

但重子粒子越靠近，液體就變得越熱，

pushing photons to ping around with incredible force.

以驚人的力量推動光子四處彈射。

This is the power of pressure, specifically radiation pressure,

這就是壓力的力量，

明確來說是輻射壓，

battling to push things apart.

拼命地推，將東西拆散。

With each of gravity’s vicious tugs squeezing photons and matter together,

引力每每惡意拉扯， 將光子和物質擠在一起，

pressure exerts a forceful shove back.

壓力都不厭其煩地使力推回去。

And as the two giants struggle, they heave this fluid back and forth—

兩個巨人鬥爭的動作讓液體來回搖動，

creating massive waves called baryonic acoustic oscillations.

造出巨大的波浪：重子聲學振盪，

它以近光速三分之二的速度移動，

Moving at almost two thirds the speed of light

these BAOs ripple across space,

傳遍整個太空，

impacting the universe on the biggest scale imaginable.

以能想像出的最大規模衝擊宇宙。

These rolling waves determine the distribution of matter throughout space,

這些滾滾大波決定物質在宇宙各處的分佈，

meaning that today— almost 14 billion years after this fight began—

也就是說現在，

大戰開打後約 140 億年，

we're more likely to find galaxies at their peaks

在波峰處較可能找到銀河，

and empty space in their troughs.

波谷則比較可能空無一物。

And that’s not all.

還不只這些。

We can still see these ripples in the background radiation of the universe,

我們還能在宇宙的背景輻射中看到這些漣漪，

a permanent reminder of this epic brawl.

提醒我們這場重磅級的鬥爭曾經存在。

But after being locked in a stalemate for roughly 370,000 years,

但，經過約 37 萬年的僵持，

the tide of our battle finally begins to turn.

這場大戰的局勢終於要開始翻轉了。

After all this time, the heat from the Big Bang has dissipated significantly,

經過這麼久，大爆炸的高溫 已經消散一大半，

cooling the universe down to a temperature

宇宙逐漸冷卻，溫度下降到

at which loose electrons start to pair up with protons.

不受束縛的電子開始跟光子結合。

Known as the “era of recombination,”

這個時代稱為「復合時代」，

this stops electrons from recklessly pinging around.

此時電子不再魯莽地四處亂跑。

This allows light to stream freely for the first time,

讓光頭一次能自由地流動，

illuminating the universe.

照亮宇宙。

These photons now only exert a tiny force on the neutral atoms they interact with,

這些光子現在只對 和它們交互作用的中性原子

產生微小的力量，

gradually reducing the power of pressure.

漸漸減少壓力。

And with that, it’s time to crown our champion!

根據這些解說，是時候加冕冠軍了。

The undefeated force, the most pervasive power in the universe:

戰無不克之力，無處不在之力：

it’s gravity!

是～～引力！

And yet, this rivalry isn’t over.

但是競爭尚未結束。

A similar battle continues between these two sworn enemies today,

現今，這兩位宿敵仍 重複著和以前一樣的對戰，

within every single star.

在每一個恆星裡。

As gravity pulls a star’s gas inward,

當引力將恆星的氣體向內拉時，

pressure increases and pushes the matter back outward.

壓力會增加，將物質向外推回去。

This push and pull keeps the Sun, and all other stars,

這股推拉力讓太陽及所有恆星

stable for billions of years.

保持長達數十億年的穩定。

In fact, this clash of the titans is the same reason

其實，這幾位巨人的衝突

正是地球的大氣 沒有垮向地面的理由。

Earth’s atmosphere doesn’t collapse to the ground.

So while their greatest fight might have ended,

所以，雖然它們最大的 一仗可能已經結束了，

these two warriors are still to be locked in combat—

這兩位戰士還是只能繼續交戰，

even as a new challenger approaches.

即使有新的挑戰者前來。