宇宙中最极端的爆炸：英语精读讲义

Supernovae are the most powerful explosions in the universe,

超新星是宇宙中最猛烈的爆炸，

unleashing enough energy to outshine galaxies. 語法

释放出的能量足以让星系黯然失色。

We have no real metaphor for their power. 短語搭配

我们找不到任何真正贴切的比喻来形容它的威力。

If the sun were to magically go supernova, 語法

如果太阳突然像变魔术一样变成了超新星，

it would feel like you were being hit by the energy of a nuclear explosion

感觉就像是你被核爆炸的能量击中了一样，

every second for weeks.

而且接连几周每一秒都在承受。

While supernovae are the engines of creation, 語法

虽然超新星是创造的引擎，

forging the elements that enable life,

锻造出了孕育生命的各种元素，

they also burn sterile whole regions of galaxies.

但它们也会将星系中整片区域烧成不毛之地。

So, what would happen if one hit Earth?

那么，如果地球被击中会发生什么？

There are, roughly speaking, 短語搭配

粗略来说，

two ways to make a supernova.

超新星的形成有两种方式。

Either the core of a massive star implodes,

一种是大质量恒星的核心发生内爆，

or, less common,

另一种不太常见的情况是，

a white dwarf gains mass to the point 語法

白矮星的质量增加到了一个临界点，

where it ignites explosive nuclear fusion.

从而点燃了爆炸性的核聚变。

The outcome is the same,

结果是一样的，

a supernova explosion.

都会发生超新星爆炸。

When we think of an explosion on Earth,

当我们想到地球上的爆炸时，

we think of something that happens fast and ends.

我们会觉得它发生得快，结束得也快。

But a supernova is more like a volcanic eruption 表達脈絡

但超新星更像是一场火山爆发，

followed by a tsunami.

紧随其后的是一场海啸。

At first, there's a colorful ball of hot expanding gas,

起初，会出现一团色彩斑斓、不断膨胀的炽热气体球，

creating a spectacular cloud that will shine for about a month.

形成一团壮观的云，大约会闪耀一个月的时间。

But then, it doesn't stop.

但随后，它并不会停止。

Hot and dangerous gas rushes outwards at speeds of 10,000 km a second

炽热而危险的气体以每秒 10,000 公里的速度向外冲去，

through the near vacuum of space,

穿过近乎真空的太空，

sweeping up the sparse gas of the galaxy. 短語動詞

席卷星系中稀薄的气体。

This wall of gas expands for tens of thousands of years

这堵气体墙会持续膨胀数万年，

and will eventually span up to dozens of light years

最终跨越几十光年的范围，

until it finally cools off and disperses its substance back into the galaxy. 短語動詞

直到它完全冷却下来，并将物质散布回星系中。

So, what if this star tsunami hits us?

那么，如果这场恒星海啸击中了我们呢？

Well, the damage depends on how far away it is. 短語搭配

嗯，破坏程度取决于它离我们有多远。

Stage one,

第一阶段，

thousands of light years away.

几千光年外。

Humans have witnessed dozens of supernovae,

人类已经目睹过几十颗超新星，

but all of them were thousands of light years away.

但它们都在几千光年之外。

They appeared as new stars,

它们看起来就像是新出现的星星，

some outshining the moon,

有的甚至比月亮还要亮，

twinkling for a few weeks,

闪烁几周后，

and disappearing.

就会消失不见。

Aside from looking very pretty at this distance, 語法

在这么远的距离，除了看起来很漂亮之外，

they don't do much to us.

它们对我们没有太大的影响。

Stage two,

第二阶段，

300 light years away.

300光年外。

Things begin to get a bit icky 用詞

事情开始变得有点糟糕了，

once a supernova occurs around 300 light years away.

一旦超新星发生在距离我们300光年左右的地方。

We can expect one this close to us every few million years.

每隔几百万年，我们就能预期一次如此近距离的爆发。

A single star giving the night sky an eerie glow like twilight.

单独一颗恒星会让夜空泛起像黄昏一样的诡异光芒。

And while this is far enough away and dim enough to not do harm to us, 短語搭配

虽然这个距离足够远，光度也足够暗，不会对我们造成伤害，

they can affect the Earth.

但它们确实会影响地球。

At these distances,

在这个距离上，

it's like being hit by the last weak waves of the star tsunami.

就像是被恒星海啸最后微弱的波浪击中了一样。

Not strong enough to do real damage,

虽然不足以造成实质性的破坏，

but still noticeable.

但仍然很引人注目。

In fact,

事实上，

we know that over the past 10 million years,

我们知道在过去的一千万年里，

multiple supernovae have struck Earth from these distances

有多颗超新星在这样的距离击中过地球，

because we can find radioactive isotopes of iron

因为我们可以找到铁的放射性同位素，

deep in the rocks and sediments at the bottom of the ocean.

它们深埋在海底的岩石和沉积物中。

Amazingly,

令人惊奇的是，

these supernovae around the solar system

太阳系周围的这些超新星

have cleared a 1,000-light-year wide pocket of space that's called the Local Bubble. 文化背景

清空了宽达1000光年的太空区域，被称为“本地泡”。

They blew away the interstellar gas and dust,

它们吹散了星际气体和尘埃，

creating a lumpy wall of gas that's now a cradle for star formation. 習語

形成了一堵凹凸不平的气体墙，如今成了恒星形成的摇篮。

Stage three,

第三阶段，

150 light years away.

150光年外。

Once a supernova happens much closer than 300 light years,

一旦超新星发生在距离不到300光年的地方，

we're approaching the zone where it does real damage.

我们就接近了它能造成实质性破坏的区域。

Stars have extremely powerful magnetic fields.

恒星拥有极强的磁场。

When they die,

当它们死亡时，

the tsunami of dead star actually retains a lot of this magnetic energy

死亡恒星的海啸实际上保留了大量的磁能，

woven through the shock wave that expands outwards.

交织在向外膨胀的冲击波中。

In this highly magnetized cloud,

在这团高度磁化的星云中，

we get conditions like in a huge particle accelerator

我们会遇到类似巨型粒子加速器的情况，

that's accelerating charged particles like protons, nuclei, and electrons to immense speeds,

它将质子、原子核和电子等带电粒子加速到极高的速度，

which means we have an expanding cloud that is shooting deadly radiation in all directions

这意味着我们有一团不断膨胀的星云，在四面八方发射致命的辐射，

long after the bright light from the initial explosion has faded away. 語法

哪怕是在最初爆炸的强光褪去很久之后。

If a supernova happens too close by,

如果超新星离得太近，

waves of these cosmic rays will wash over the solar system for thousands of years. 習語

这种宇宙射线的波动将冲刷太阳系长达数千年。

While we're mostly protected on Earth's surface by the atmosphere and ozone layer,

虽然我们在地球表面主要受到大气层和臭氧层的保护，

the influx of extra radiation will still increase cancer and mutation rates.

但额外涌入的辐射仍然会增加癌症和基因突变的发病率。

Not enough to cause a mass extinction,

虽然不足以引起大规模灭绝，

but it will be noticeable.

但影响将是显著的。

Spaceflight would become impossible in the solar system

在太阳系内，太空飞行将变得不可能，

as astronauts wouldn't survive the waves of radiation for long.

因为宇航员无法在这样的辐射波中长期存活。

We don't know exactly how bad this would be,

我们不确定具体会有多糟糕，

but a supernova that is close enough may trap our species on Earth for generations,

但一颗足够近的超新星可能会将人类困在地球上几代人，

maybe thousands of years.

也许长达几千年。

It only gets worse from here. 表達脈絡

从这往后情况只会更糟。

Stage four,

第四阶段，

closer than 100 light years.

距离不到100光年。

Within 100 light years,

在100光年之内，

things get bad as a supernova disrupts our climate in ways that we don't fully understand yet.

情况会变得很糟糕，因为超新星会以我们尚未完全了解的方式破坏我们的气候。

There are a few unpleasant things happening all one after another.

一些不好的事情会接二连三地发生。

First, the high-energy photons arrive from the explosion,

首先，爆炸产生的高能光子到达，

followed by many decades of radiation from the radioactive tsunami,

紧接着是来自放射性海啸长达数十年的辐射，

both of which seriously damage the ozone layer, 語法

这两者都会严重破坏臭氧层，

Earth's shield against harmful radiation.

也就是地球抵御有害辐射的盾牌。

The ozone layer absorbs ultraviolet radiation by breaking apart ozone,

臭氧层吸收紫外线辐射的方式是将臭氧，

O3, into O2 and a free oxygen atom,

也就是O3，分解为O2和一个游离的氧原子，

which later reforms back into another ozone molecule.

稍后它会重新结合成另一个臭氧分子。

But the supernova radiation breaks up nitrogen molecules that gobble up the free oxygen, 短語動詞

但超新星辐射会分解氮分子，进而吞噬游离氧，

breaking the cycle and depleting the ozone layer quickly.

打破循环并迅速消耗臭氧层。

Without a radiation shield,

没有了防辐射盾，

everybody living on the surface is exposed to very high levels of UV radiation from our sun.

生活在表面的每个人都会暴露在我们太阳产生的极高强度的紫外线辐射下。

Cancer rates would skyrocket,

癌症发生率会飙升，

and just going outside during the day could be life-threatening.

仅仅在白天出门就可能危及生命。

The extra radiation would also kill a lot,

额外的辐射也会杀死大量的，

if not most, 表達脈絡

甚至绝大多数的

of the plankton in the oceans that live near the surface

生活在海洋表面附近的浮游生物，

and are the basis for the marine food chains,

它们是海洋食物链的基础，

leading to a mass extinction. 語法

从而导致大规模灭绝。

Worse still, 表達脈絡

更糟的是，

supernova radiation would ionize gas in the atmosphere,

超新星辐射会电离大气层中的气体，

which means that it would punch through molecules and knock electrons off nuclei,

这意味着它会穿透分子并把电子从原子核上击飞，

leaving them charged.

使其带电。

These charged nuclei then act as seeds for water vapor to gather 習語

这些带电的原子核随后就成了水蒸气聚集的种子，

and form massive global clouds.

从而形成覆盖全球的巨大云层。

In the worst case, 短語搭配

在最坏的情况下，

they would reflect enough sunlight to trigger an ice age.

它们会反射足够的阳光，从而引发冰河时期。

In fact, it's thought that the ice age 2 and 1/2 million years ago 語法

事实上，人们认为250万年前的冰河时期

was caused by the supernova.

就是由超新星引起的。

Some scientists even think that a supernova about 60 light years away

有些科学家甚至认为，大约60光年外的一颗超新星

might have been the cause of the Devonian mass extinction 350 million years ago. 語法

可能是3.5亿年前泥盆纪大灭绝的起因。

But wait, there's more.

但是等等，还有更糟的。

The electrons punched free by the radiation form enormous electric avalanches,

被辐射击飞的电子会形成巨大的电子雪崩，

or in other words, lightning. 表達脈絡

换句话说，就是闪电。

Earth is hit by some of the worst thunderstorms in millions of years.

地球将遭受数百万年来最严重的雷暴袭击。

The intense lightning causes global wildfires that consume forests and crops,

强烈的闪电会引发全球性野火，吞噬森林和庄稼，

devastate cities, disrupt our electrical grids,

摧毁城市，破坏我们的电网

and global supply chains.

和全球供应链。

All while a decimated ozone layer leaks deadly radiation. 語法

与此同时，千疮百孔的臭氧层还会漏入致命的辐射。

While in the past the ecosystem may have bounced back from a nearby supernova 短語動詞

虽然在过去，生态系统可能在附近的超新星爆发后

after a few thousand or million years,

几千或几百万年内恢复了过来，

there's no guarantee modern civilization can take a hit of this magnitude. 講解

但无法保证现代文明能够承受如此巨大规模的打击。

We would face food shortages,

我们将面临食物短缺、

skyrocketing prices, and wars

物价飞涨和战争，

as nations struggle to not be consumed by chaos.

因为各个国家都在努力不被混乱所吞噬。

So, a supernova this close would,

所以，如此之近的超新星，

at the very least, do significant damage 短語搭配

至少会造成严重的破坏，

for hundreds or thousands of years,

这种破坏会持续数百年甚至数千年，

if not end our modern civilization,

甚至可能终结我们的现代文明，

and with it millions or even billions of lives.

并随之夺走数百万甚至数十亿人的生命。

Still, humanity would likely survive and could recover.

不过，人类很可能还是能生存下来，并能够恢复。

Stage five,

第五阶段，

closer than 25 light years.

距离不到25光年。

A supernova closer than 25 light years

一颗距离不到25光年的超新星

means that we're in its kill radius,

意味着我们进入了它的杀伤半径，

where a mass extinction is all but guaranteed. 習語

大规模灭绝几乎是不可避免的。

Probably about half of the ozone layer would be destroyed,

大约一半的臭氧层将被破坏，

and massive climatic disruption on a scale we've never witnessed

规模前所未见的巨大气候剧变

would ravage Earth.

将肆虐地球。

Entire ecosystems would swiftly be wiped out by radiation 短語動詞

整个生态系统将迅速被辐射抹除

as global wildfires envelop the planet.

全球性野火将席卷整个星球。

All the things described before happen,

之前描述的所有事情都会发生，

but way more intensely and much faster. 用詞

但强度更大，速度也快得多。

A few people might survive for years in bunkers if they have food supplies,

少数人如果拥有食物储备，也许能在地堡里幸存几年，

but the world they return to will be devastated

但当他们重返地表时，世界将满目疮痍，

and hostile to life for hundreds of thousands of years.

并在几十万年内都不适宜生命生存。

Human extinction is extremely likely.

人类灭绝的可能性极大。

Final stage,

最终阶段，

four light years.

4光年。

Being any closer to a supernova is very unlikely

距离超新星再近一点的可能性微乎其微，

because space is big.

因为宇宙非常大。

But the effects would be extreme.

但其影响将是极端的。

Even from four light years away,

即使是在4光年外，

the distance to Alpha Centauri,

也就是到半人马座阿尔法星的距离，

a supernova would be almost as bright as the sun in the sky. 語法

超新星在天空中的亮度也几乎与太阳相当。

While casting two shadows could be fun for a few hours,

虽然能投下两个影子也许在头几个小时内挺有趣，

within days the Earth's surface gets as hot as a sauna,

但几天之内，地球表面就会变得像桑拿房一样热，

baking the surface for weeks until the explosion fades.

地表会被连续烘烤数周，直到爆炸的光芒减弱。

The surface of Earth burns,

地球表面将会燃烧，

scoured of life.

生命被洗劫一空。

Even the oceans aren't safe.

就连海洋也不安全。

The massive amount of radiation that follows

随后而来的海量辐射

burns away the ozone layer,

将会烧毁臭氧层，

killing everything that sees sunlight.

杀死所有暴露在阳光下的生物。

It would be the largest extinction event in history,

这将成为历史上最大规模的灭绝事件，

reducing life to a few survivors in the deep sea 短語搭配

让生命只剩下深海中的极少数幸存者，

and critters in the deep soil.

以及深土中的小生物。

Life basically has to start over. 短語動詞

生命基本上不得不重新来过。

Conclusion.

结论。

How worried do you need to be?

你需要有多担心？

So, should you worry?

那么，你应该担心吗？

No.

不用。

Fortunately,

幸运的是，

there are only a handful of stars that may explode 短語搭配

只有寥寥几颗可能发生爆炸的恒星

within 1,000 light years of Earth,

位于距离地球1000光年以内，

and none are close enough to be a serious threat.

而且没有一颗近到足以构成严重威胁。

Even better,

更好的是，

these stars will probably not go supernova for many millions of years. 短語搭配

这些恒星可能在未来几百万年内都不会变成超新星。

So, you are safe.

所以，你是安全的。

But there's no guarantee for the far future.

但对于遥远的未来，这可没有保证。

As stars orbit the galaxy,

随着恒星在星系中运行，

our descendants may find themselves dangerously close to a supernova. 語法

我们的子孙后代可能会发现自己离超新星近得危险。

But by then,

但到那时，

a far more advanced and wiser humanity

一个更先进、更明智的人类社会

will hopefully be able to just move out of the way. 短語動詞

有望能够直接避开。

In any case, 表達脈絡

无论如何，

you can sleep well tonight

今晚你可以睡个好觉，

under the beautiful night sky.

就在这美丽的夜空下。