如果发生核战争会怎样？：英语精读讲义

70 years ago the nuclear bombs dropped over Hiroshima and Nagasaki exploded 文化背景

70年前，投向广岛和长崎的核弹爆炸了

and to this day remain the only use of nuclear weapons for warfare. 短語搭配

而直到今天，这仍是核武器唯一一次被用于战争。

But with around 15,000 warheads remaining in the world, 用詞

但如今世界上仍有约1.5万枚核弹头，

what happens if we have a nuclear war?

如果爆发核战争，会发生什么？

The impact of a single nuclear bomb depends on many factors like the weather, weapon design,

一枚核弹的影响取决于许多因素，比如天气、武器设计、

geographical layout of where the bomb hits,

核弹命中地点的地理环境，

and if it explodes in the air or on the ground.

以及它是在空中还是地面爆炸。

Approximately 35% of the energy comes in the form of thermal radiation or heat. 講解

约35%的能量会以热辐射，也就是热量的形式释放。

Since thermal radiation travels at approximately the speed of light,

由于热辐射的传播速度接近光速，

the flash of light and the heat comes several seconds before the blast wave.

强光和热量会比冲击波早几秒到达。

And this causes flash blindness to anyone looking, 用詞

这会让所有直视它的人出现闪光盲，

a temporary blindness of a few minutes.

也就是持续几分钟的暂时性失明。

With a 1 megaton bomb, 用詞

以一枚100万吨当量的核弹为例，

which is 80 times larger than the Hiroshima bomb,

它的威力是广岛原子弹的80倍，

but much smaller than many modern nuclear weapons,

但仍比许多现代核武器小得多，

those 21 km away would experience flash blindness on a clear day

在晴朗的白天，21公里外的人会出现闪光盲，

and even up to 85 km away on a clear night.

而在晴朗的夜晚，最远85公里外的人也会如此。

Thermal radiation burns happen closer to the bomb with first-degree burns occurring around 11 km, 用詞

在离核弹更近的地方，热辐射会造成烧伤：约11公里处为一度烧伤，

second-degree burns at 10 km,

10公里处为二度烧伤，

and third-degree burns destroying skin tissue at 8 km.

8公里处则为三度烧伤，皮肤组织会遭到破坏。

Third-degree burns that cover over 24% of the body will likely be fatal without quick medical care.

如果三度烧伤覆盖身体超过24%，得不到及时救治就很可能致命。

These distances are variable depending on the weather and what clothing you're wearing. 短語搭配

这些距离会因天气和你所穿的衣物而变化。

White clothing, for example, can reflect some of the energy

例如，白色衣物能反射一部分能量，

while darker clothes absorb it. 語法

而深色衣物会吸收能量。

At its center, the Hiroshima explosion was estimated to be 300,000 °C, 語法

据估计，广岛爆炸中心的温度高达30万°C，

which is over 300 times hotter than the temperature bodies are cremated at. 語法

比火化遗体的温度高出300多倍。

This intense heat reduces a body to its basic elements.

这种极端高温会把人体分解成最基本的元素。

The radiation from the blast also behaves like sunlight,

爆炸产生的辐射也像阳光一样传播，

so objects cast shadows where the radiation doesn't directly hit. 短語搭配

因此在辐射没有直接照到的地方，物体会留下影子。

But most of the energy released in a nuclear explosion is in the blast,

但核爆炸释放的大部分能量都形成了冲击波，

which drives air away from the site of the explosion,

它会把空气从爆炸地点猛烈推开，

creating a sudden change in air pressure that can crush objects or knock them down. 語法

造成气压骤变，足以压碎物体或将其掀倒。

If we use a 1 megaton bomb as an example again, 表達脈絡

再次以一枚100万吨当量的核弹为例，

within a 6 km radius,

在半径6公里内，

there would be an estimated 180 tons of force on the wall of every two-story building 語法

每栋两层楼建筑的墙面估计都要承受180吨的冲击力，

with wind speeds of 255 km/h.

风速可达255公里/小时。

Within a 1 km radius,

在半径1公里内，

the peak pressure is four times greater and wind speeds reach 756 km/h.

峰值压力会增至4倍，风速达到756公里/小时。

The human body can endure this amount of pressure.

人体本身可以承受这么大的压力。

However, the winds would create fatal collisions with nearby objects,

然而，狂风会把人撞向附近物体，造成致命伤害，

so deaths would largely be from collapsed buildings.

所以死亡主要会由建筑物倒塌造成。

All this at 1 megaton.

而这一切，还只是一枚100万吨当量核弹的威力。

Compare that with the largest nuclear bomb ever detonated, 表達脈絡

再来看看有史以来引爆过的最大核弹：

the 50 megaton Tsar Bomba dropped on an isolated island in Russia, 文化背景

在俄罗斯一座偏远岛屿上投下的5,000万吨当量“沙皇炸弹”，

and you're looking at 3,333 Hiroshima bombs combined. 習語

它的威力相当于3,333枚广岛原子弹叠加在一起。

If you happen to survive all this, 語法

如果你侥幸熬过了这一切，

now you have to worry about radiation.

接下来还得担心辐射。

Now, not all radiation is harmful. 語法

当然，并非所有辐射都有害。

We're exposed to different forms of radiation every day like our phones, 短語搭配

我们每天都会接触不同形式的辐射，比如手机产生的辐射，

but ionizing radiation at the center of a nuclear bomb has enough energy to rip electrons from atoms. 講解

但核弹中心的电离辐射能量足以把电子从原子中剥离。

But the amount of radiation you encounter is greatly affected by whether you're outside or inside, 語法

不过，你接触到的辐射量会因许多因素而大不相同，比如你是在室外还是室内，

in a wooden structure or a cement structure, and so on.

身处木结构还是水泥结构中，等等。

Exposure to 600 REM radiation has a 90% chance of creating fatal illness, 用詞

受到600 REM的辐射，有90%的概率会引发致命疾病，

while a dose of 450 REM is estimated to create a fatal dose within half of those affected.

而450 REM的辐射剂量，估计会让一半受影响者死亡。

But even those who recover still suffer long-term.

即便康复，幸存者仍会受到长期影响。

Molecular bonds and strands of DNA are broken,

分子键和DNA链会断裂，

and while most repair, around a quarter don't, 語法

虽然大部分都能修复，但约有四分之一无法修复，

which can result in future genetic mutations and increased probability of cancer. 短語搭配

这可能导致日后出现基因突变，并增加患癌概率。

Then there is the fallout. 講解

此外，还有放射性沉降物。

When a bomb is detonated on or near the surface of the Earth,

当核弹在地表或地表附近引爆时，

the blast creates a crater and the material that used to be deposited in the crater

爆炸会炸出一个弹坑，原本位于弹坑范围内的物质

is carried up into the air as vaporized dirt particles,

会化为汽化的尘土颗粒，被卷入空中，

forming the familiar mushroom cloud.

形成我们熟悉的蘑菇云。

These particles become radioactive and eventually condense

这些颗粒会变得具有放射性，并最终凝结，

and come back down as fallout.

再以放射性沉降物的形式落回地面。

Depending on wind conditions,

根据风况不同，

radioactive fallout can travel for hundreds of miles.

放射性沉降物可以飘到数百英里之外。

And though it can fall in the form of black rain,

虽然它有时会以黑雨的形式落下，

for the most part, you can't detect fallout with your senses. 短語搭配

但大多数时候，你无法通过感官察觉放射性沉降物。

Luckily, fallout radiation decays fairly quickly,

幸运的是，沉降物的放射性会相当快地衰减，

and within 2 weeks material will have declined to about 1% of its initial radiation level. 語法

两周内，其辐射水平就会降至初始水平的约1%。

But you would have to stay in a shelter until then.

但在那之前，你必须一直待在避难所里。

So, what if a multi-bomb nuclear war broke out? 講解

那么，如果爆发一场动用多枚核弹的核战争，会怎样？

A recent study imagined what 100 detonated warheads,

最近一项研究设想了100枚核弹头爆炸的情景，

the approximate size of a Hiroshima bomb,

每枚威力大致相当于一枚广岛原子弹，

would look like if India and Pakistan went to war.

用以推演印度与巴基斯坦开战会是什么样子。

These two nations have relatively small stockpiles of weapons

这两个国家的武器储备相对较少，

compared to countries like the US, Russia, and China.

尤其是与美国、俄罗斯和中国等国家相比。

However, this would still do huge damage. 短語搭配

尽管如此，破坏依然会极其严重。

After the nuclear exchange, 用詞

在核武器交锋之后，

5 megatons of black carbon would immediately enter the atmosphere,

500万吨黑碳会立即进入大气层，

causing global temperatures to fall and receive 9% less rain annually.

导致全球气温下降，年降雨量减少9%。

Though these changes sound small,

虽然这些变化听起来不大，

they could be enough to trigger crop failures and famine. 語法

却足以引发农作物歉收和饥荒。

A separate study estimated 2 billion people would starve in the wake of a 100 A-bomb war. 習語

另一项研究估计，一场动用100枚原子弹的战争过后，将有20亿人挨饿。

So, what should you do?

那么，你该怎么办？

We created a video called How to Survive a Nuclear War

我们制作了一期名为《如何在核战争中生存》的视频，

that looks into strategies for safety in the event of a nuclear bomb near you, 講解

其中探讨了附近发生核爆时的安全应对策略，

which you can click on here to check out.

点击这里就可以观看。

Don't forget to subscribe for more weekly science videos every Thursday

别忘了订阅，每周四观看更多科学视频，

and click that bell to make sure you get notifications for our videos.

还要点击铃铛，确保能收到我们的视频通知。

We'll see you next week.

我们下周见。