Debra Lee Scanlon, age 10, of Los Angeles, California, for her question:

Where is the wind going?

The wind seems to blow where it chooses, without any plans at all. Actually like everything else in nature, it must obey very definite rules and regulations. There is always a reason why it blows from one place to another,

The blanket of air above our heads is like a great, filmy ocean. It is always restless and turbulent. The spinning earth upsets it. So does the smiling sun. The sun causes some masses of air to become warmer than others. Warm air expands and becomes thinner. This patch of thin, light air is like a hole in the atmosphere.

Scoop a pail of water from a pond and the surrounding water flows in to fill up the hole. The cooler air around the thin, light region also flows in to even things up. This flowing air is the wind.

The wind is a current of heavier air flowing towards an area of lighter air. It may also be a current flowing out from a vast mass of heavy air. The spinning earth gives a twist to the direction in which it flows.