Amy Jeanne Cropf, age 10, of Lititz, Pennsylvania, for her question:

Does a rainbow start on land or in the air?

The parents of a rainbow are the sun. and a weeping cloud: They, must be on opposite sides of the sky and their magic is created in the air. Then the ribboned rainbow arches over the heavens and seems to reach down to touch the earth. Actually its colors are rays of light that reach our eyes from different angles. And our eyes are shaped to form them into circular patterns. The arch we see is half of a circle.   

 A rainbow is born when the sun is rather low and its beams dart across to a rain cloud on the other side of the sky. The falling raindrops act like tiny glass prisms and scatter the sunbeams into the separate colors of light. The colors are separated at different angles and arrange themselves in orderly bands. And all this happens in the air    between the sun, the rain cloud and our admiring eyes.