來自太空的死亡——伽瑪射線暴（Gamma-Ray Bursts）揭秘：英語精讀講義

Imagine if you could gather the energy from every star within a 100 million light years, 文法

想像一下，如果你能收集一億光年內所有恆星的能量，

from thousands of galaxies,

它們來自數千個星系，

each with billions of stars.

每個星系都有數十億顆恆星。

Imagine you could take this kind of power

想像一下，你可以利用這種能量

and use it to fire the biggest super weapon in the universe.

來發射宇宙中最大的超級武器。

Imagine the damage you could do.

想像一下你能造成的破壞。

It turns out you don't need to imagine it. 表達脈絡

事實證明，你不需要去想像。

These exist and they're called gamma ray bursts.

這些確實存在，它們被稱為伽瑪射線暴。

But what are these cosmic snipers? 慣用語

但這些宇宙狙擊手究竟是什麼？

And what happens if one takes a shot at Earth?

如果它們向地球開了一槍會發生什麼事？

To understand gamma ray bursts, 表達脈絡

要理解伽瑪射線暴，

we first have to understand gamma rays.

我們首先必須了解伽瑪射線。

Gamma rays are electromagnetic radiation,

伽瑪射線是電磁輻射，

waves which carry energy just like visible light. 表達脈絡

就像可見光一樣攜帶能量的波。

Visible light is a tiny part of the electromagnetic spectrum.

可見光只是電磁波譜的一小部分。

It's the part your eyes can see.

它是你眼睛能看到的那部分。

At lower energies,

在較低能量的一端，

there are radio waves,

有無線電波、

microwaves, and infrared.

微波和紅外線。

And at higher energies,

而在較高能量的一端，

ultraviolet, X-rays,

是紫外線、X射線、

and gamma rays.

和伽瑪射線。

Gamma rays are incredibly powerful.

伽瑪射線無比強大。

A single gamma ray photon is more energetic than a million visible photons combined.

一個伽瑪射線光子的能量比一百萬個可見光光子加起來還要高。

Their high energy makes gamma rays a form of ionizing radiation,

它們的高能量使伽瑪射線成為一種游離輻射，

meaning they are energetic enough to break apart atomic bonds. 講解

這意味著它們有足夠的能量破壞原子鍵。

This makes them dangerous to you and me.

這使它們對你我來說都很危險。

Ionizing radiation disrupts the delicate biochemical machinery that keeps us alive,

游離輻射會破壞讓我們存活的精密生化機制，

like a 9 mm bullet through a clock. 慣用語

就像一顆9毫米子彈射穿了鐘錶一樣。

Fortunately,

幸運的是，

on Earth,

在地球上，

the ozone layer blocks gamma rays,

臭氧層阻擋了伽瑪射線，

filtering them out before they can harm us. 片語動詞

在它們傷害我們之前將其過濾掉。

But if the atmosphere blocks gamma rays from space,

但是，如果大氣層阻擋了來自太空的伽瑪射線，

how were gamma ray bursts or GRBs from space ever discovered?

那麼來自太空的伽瑪射線暴或稱 GRB 是如何被發現的呢？

During the Cold War,

在冷戰期間，

the USA sent up spy satellites 片語動詞

美國發射了間諜衛星，

which could detect gamma rays from Soviet nuclear tests in space.

這些衛星可以探測到蘇聯在太空進行核試驗時產生的伽瑪射線。

They didn't see any bombs,

他們沒有看到任何核彈，

but they did observe faint bursts coming from space 文法

但卻觀察到了來自太空的微弱閃發，

lasting only a few seconds.

僅僅持續了幾秒鐘。

To date, 片語搭配

迄今為止，

this may be the only major scientific discovery made by spy satellites

這可能是間諜衛星取得的唯一一項重大科學發現，

that we know about anyway. 語氣意圖

至少是我們所知的。

Astronomers use telescopes that see different kinds of light to make their discoveries,

天文學家使用能夠看到不同種類光線的望遠鏡來進行發現，

and these spy satellites gave them a new pair of eyes. 慣用語

而這些間諜衛星給了他們一雙新的眼睛。

They were a mystery for 30 years,

這在長達三十年的時間裡是個謎，

but eventually we discovered the source of a GRB,

但最終我們發現了一個 GRB 的源頭，

a galaxy 6 billion light years away.

一個位於60億光年外的星系。

If a GRB can be seen from such a distance, 文法

如果在那麼遠的距離還能看到 GRB，

then it must be incredibly energetic,

那麼它一定具有極其巨大的能量，

releasing more energy in a second than the sun will in its entire 10 billion year lifetime, 文法

它在一秒鐘內釋放的能量比太陽在一百億年生命週期中釋放的還要多，

making GRBs the brightest events in the universe. 文法

這使 GRB 成為宇宙中最明亮的事件。

So,

那麼，

where do they come from?

它們從何而來？

GRBs accompany some of the most violent cataclysmic deaths in the universe

GRB 伴隨著宇宙中最猛烈的毀滅性死亡

and the birth of black holes.

以及黑洞的誕生。

There are two types of gamma ray burst,

伽瑪射線暴分為兩種，

short and long,

短暴和長暴，

and each has their own source.

各自有著不同的來源。

Long GRBs last about a minute,

長的 GRB 持續大約一分鐘，

and scientists think they are produced by supernova

科學家認為它們是由超新星產生的，

when the core of a massive star collapses to become a black hole. 文法

當大質量恆星的核心坍縮成為黑洞時。

Short GRBs last a second

短的 GRB 持續一秒，

and are produced when two neutron stars in a binary merge. 用詞

是由雙星系統中的兩顆中子星合併時產生的。

Over millions of years,

歷經數百萬年，

their orbits decay by emitting gravitational waves. 用詞

它們的軌道因為發射重力波而衰減。

Once they're close enough to touch, 文法

一旦它們近到可以接觸，

they crash and splash into each other

它們就會碰撞並迸射到彼此身上，

forming a black hole.

形成一個黑洞。

Both supernova and neutron star mergers make the same thing,

超新星和中子星合併都會產生同樣的東西，

black holes

即黑洞，

surrounded by a magnetized disc of gas left over from their parent stars. 片語動詞

周圍環繞著來自其母星殘留氣體的磁化盤。

In these environments,

在這些環境中，

the rotation winds up the magnetic field 片語動詞

旋轉會捲繞磁場，

which funnels hot jets of particles traveling at maybe the speed of light.

從而將可能以光速行進的熱粒子噴流漏斗化。

The gas in this funnel creates two tight jets of high energy gamma rays,

這個漏斗中的氣體產生了束縛緊密的高能伽瑪射線噴流，

like a celestial laser gun. 慣用語

就像一把天體雷射槍。

So,

因此，

unlike other cosmic explosions which spread out and fade, 表達脈絡

不同於其他會擴散並消退的宇宙爆炸，

GRBs stay focused and can be seen from much further.

GRB 保持著聚焦，可以從更遠的地方被觀測到。

Any more detail would require too much mathematics for a YouTube video. 語氣意圖

再多的細節對於一部 YouTube 影片來說就需要太多数學知識了。

The universe is full of these cosmic snipers,

宇宙中充滿了這些宇宙狙擊手，

firing blindly and randomly into the dark, 慣用語

在黑暗中盲目而隨機地開火，

and they're hitting us all the time.

它們一直在擊中我們。

On average, 片語搭配

平均而言，

we detect one per day.

我們每天會探測到一個。

Fortunately,

幸運的是，

most are harmless.

大多數是無害的。

All the bursts we have detected so far 文法

到目前為止，我們探測到的所有射線暴

originated outside the Milky Way,

都起源於銀河系之外，

too far away to hurt us.

距離我們太遠，無法造成傷害。

But a nearby GRB could be disastrous.

但如果在附近發生 GRB 可能是災難性的。

If one goes off within a few light years of us, 片語動詞

如果有一次爆發發生在我們幾光年內，

it would totally cook the surface of the Earth, 慣用語

它將徹底烤熟地球表面，

or at least the half that's facing it.

或者至少是面向它的一半。

But even a more distant GRB could still end life on Earth.

但即使是更遙遠的 GRB 仍可能終結地球上的生命。

And it wouldn't need to score a headshot to kill us. 慣用語

它甚至不需要直接爆頭就能殺死我們。

If originating from a few thousand light years away,

如果它起源於幾千光年之外，

it would be a 100 light years wide by the time it reaches us,

到達我們這裡時，它將達到 100 光年寬，

washing over the solar system like a tidal wave. 慣用語

像海嘯一樣沖刷太陽系。

Again,

再說一次，

the ozone layer protects us,

臭氧層保護著我們，

but it's better equipped to handle the trickle of ultraviolet from the sun. 片語搭配

但它更適合應對來自太陽的少量紫外線。

A gamma ray burst would overwhelm it,

伽瑪射線暴會壓垮它，

leaving us exposed to deadly solar radiation. 文法

讓我們暴露在致命的太陽輻射中。

Ozone takes years to replenish itself by natural processes, 文法

臭氧層透過自然過程自我補充需要數年時間，

which is more than enough time for the sun to burn the Earth sterile, 文法

這足以讓太陽將地球烤得寸草不生，

or at least to kill most complex life.

或至少殺死大部分複雜生命。

In fact,

事實上，

this may have already happened.

這種事可能已經發生過。

A GRB has been suggested as one possible cause of the Ordovician extinction 講解

GRB 被認為是導致奧陶紀物種滅絕的一個可能原因，

450 million years ago

發生在4.5億年前，

that eradicated almost 85% of all marine species,

滅絕了大約 85% 的海洋物種，

although it's pretty much impossible to prove. 表達脈絡

儘管這幾乎不可能被證明。

Gamma ray bursts could even be one reason we don't see life anywhere else in the universe.

伽瑪射線暴甚至可能是我們在宇宙中其他地方看不到生命的原因之一。

They might be wiping clean huge chunks of it on a regular basis. 講解

它們可能定期抹去宇宙中的大片生命。

It's been suggested that because of GRBs,

有人提出，由於 GRB 的存在，

only 10% of all galaxies might be hospitable to life similar to us. 片語搭配

只有 10% 的星系可能適宜類似我們這樣的生命生存。

So,

那麼，

are they going to kill us?

它們會殺了我們嗎？

Probably not.

可能不會。

In a galaxy like ours,

在像我們這樣的星系中，

there may only be one GRB per millennia, 文法

每千年可能只發生一次 GRB，

and to harm us, 文法

並且要傷害我們，

they must be close and directed at us.

它們必須離得很近並且直接對準我們。

But since gamma rays travel at the speed of light,

但由於伽瑪射線以光速傳播，

we won't know one is headed our way until it arrives. 講解

直到它到達，我們才會知道有一個正在向我們飛來。

So,

所以，

there could already be a GRB on its way to kill us all

可能已經有一個 GRB 正在向我們飛來，要殺死我們所有人，

and we won't know it

而我們並不知道，

until it hits us and we're dead.

直到它擊中我們，而我們死去。