Doug Humbigner, age 9, of Moses Lake, Washington, for his question:

Can you really count distance from lightning?

You can use the lightning to figure the distance of a thunderstorm. But you also need help from the thunder. Your answer may not be absolutely perfect, but chances are you will not miss by more than a mile. First, you must be able to count kith the passing seconds. . Also, the storm must be close enough for you to see the lightning and hear the thunder. Inside the raging cloud, the lightning flash and the roar of thunder happen in the same split second. But you see the flash before you hear the roar. Start counting when you see the flash and stop when you hear the thunder.

The trick works because lightning travels at the speed of light, about 186,000 miles a second. It is fast enough to reach your eyes in the same split second it happens. The thunder happened in the same spot at the same instant. But it dawdles through the air at the speed of sound, about 1,100 feet a second. It takes about five seconds to travel each mile. Stop counting when the thunder reaches your ears. Divide your answer by five and you know the miles of distance between you and the thunderhead. If you had time to countto 20, the distance between you and the storm is about four: miles. If you counted only to five, the storm is only a mile away, and maybe right over your head.