万物简史 第367期:进入对流层(8)

 Certainly there is no shortage of energy in the world above our heads. One thunderstorm, it has been calculated, can contain an amount of energy equivalent to four days' use of electricity for the whole United States. In the right conditions, storm clouds can rise to heights of six to ten miles and contain updrafts and downdrafts of one hundred miles an hour. These are often side by side, which is why pilots don't want to fly through them. In all, the internal turmoil¹ particles within the cloud pick up electrical charges.

当然，我们头顶的世界里不乏能量。据测，一次大雷雨可以包含相当于全美国4天用电量的能量。在合适的条件下，雷雨云可以升到10—15公里高度，包含l以每小时150多公里的速度上升的气流和下沉的气流。两者往往并排出现，因此飞行员不愿意从中飞过。在内部一团混乱之中，云团里面的粒子获取电荷。

For reasons not entirely² understood the lighter³ particles tend to become positively⁴ charged and to be wafted⁵ by air currents to the top of the cloud. The heavier particles linger at the base, accumulating negative charges. These negatively charged particles have a powerful urge to rush to the positively charged Earth, and good luck to anything that gets in their way. A bolt of lightning travels at 270,000 miles an hour and can heat the air around it to a decidedly crisp 50,000 degrees Fahrenheit⁶, several times hotter than the surface of the sun. At any one moment 1,800 thunderstorms are in progress around the globe—some 40,000 a day. Day and night across the planet every second about a hundred lightning bolts hit the ground. The sky is a lively place.

由于不完全了解的原因，较轻的粒子往往带上了正电荷，被气流刮到了云团顶部。较重的粒子留在基部，积累负电荷。这些带负电荷的粒子有着强烈的愿望，希望冲向带正电荷的地球，但愿夹在中间的东西走运！闪电以每小时435000公里的速度移动，可以把周围的空气加热到28000摄氏度，比太阳表面的温度还要高出几倍。在任何一个时刻，全球有1800场大雷雨正在发生——平均每天40000场左右。闪电日日夜夜划过这颗行屋，每秒钟大约有100道闪电击中大地。天空真是个生气勃勃的地方。

Much of our knowledge of what goes on up there is surprisingly recent.

我们对上面情况的了解，许多是最近的事，真是不可思议。

1 turmoil   

n.骚乱，混乱，动乱

参考例句：

• His mind was in such a turmoil that he couldn't get to sleep.内心的纷扰使他无法入睡。
• The robbery put the village in a turmoil.抢劫使全村陷入混乱。

2 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

3 lighter   

n.打火机，点火器；驳船；v.用驳船运送；light的比较级

参考例句：

• The portrait was touched up so as to make it lighter.这张画经过润色，色调明朗了一些。
• The lighter works off the car battery.引燃器利用汽车蓄电池打火。

4 positively   

adv.明确地，断然，坚决地；实在，确实

参考例句：

• She was positively glowing with happiness.她满脸幸福。
• The weather was positively poisonous.这天气着实讨厌。

5 wafted   

v.吹送，飘送，（使）浮动( waft的过去式和过去分词 )

参考例句：

• The sound of their voices wafted across the lake. 他们的声音飘过湖面传到了另一边。
• A delicious smell of freshly baked bread wafted across the garden. 花园中飘过一股刚出炉面包的香味。 来自《简明英汉词典》

6 Fahrenheit   

n./adj.华氏温度；华氏温度计(的)

参考例句：

• He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
• The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。