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 entirely understood the lighter particles tend to become positively charged and to be wafted 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 Fahrenheit, 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。