Lethell James, age 9, of Winstom‑Salem, N.C., for the question:

 What makes the sky blue?

The sky seems blue because of a trick of air and sunshine, Actually it is pitch black and spattered with dazzling stars. This is how the sky would look if we could rise above the earth's atmosphere.

Sunshine, of course, comes directly from the sun. It fans out across space in rays of white, or colorless light. Before it reaches us, it must come through the air. And the dancing molecules of air play tricks with the sunbeams.

A sunbeam of white light is really a skein of rainbow colors blended together. Each color travels on its own wave length. The blue rays are shortest the red are longest, in wave length.

The air molecules cause the short blue rays to bend and scatter. This is what we see when we look up at a clear sky. The blue rays have been bent, or refracted, from the white sunbeams and scattered all over the heavens.