Ralph Endress, aged 9, of Williamsfield, Ill., for his question:

Why does it thunder after lightning?

Imagine an electric charge of a hundred million volts! Nature pours that much force into a flash of lightning. Such a force riper through the air in a jagged path. The air tries to resist the path of the lightning. But the lightning cuts a groove of hot air through the cooled air of the storm cloud.

This all happens, of course, with the speed of lightning. Suddenly the cool air of the cloud is rent with a river of terrifically hot air. And hot air expands. This hot air expands with a crashing explosion   the thunder.

There is usually a pause between the lightning and the thunder. This is because light, carrying images to our eyes, travels faster than sound, carrying noises to our ears.