Gwynne Myers, age 12, of Winston‑Salem, N.C. for the question:

Why does a rainbow never appear in the southern sky?

 Rainbow is a trick with lights and mirrors. It depends upon angles. The lights are sloping sunbeams from the sun. The mirrors are myriad falling raindrops. The angles that make the rainbow are just right when the sun and the rain cloud are on opposite sides of the sky.

When you face a rainbow the sun is shining over your shoulder. It is fairly low in the sky, never high overhead. The best rainbows occur in the early morning or the late afternoon. Morning rainbows occur in the western part of the sky, evening rainbows in the eastern part of the sky.

The sun is never in the northern sky. Hence the sunbeams can never slope towards the southern part of the sky. Even when there is a rain. cloud in the southern sky the sunbeams could not strike it at a proper angle to make a rainbow. For they must point from the sun towards the raindrops on the opposite side of the sky.