Margie Laemmerhirt, age 11, of Libertyville, Ill., for her question:

WHAT MAKES THE SUNSET RED?

Actually our razzle‑dazzle sun is the same glorious color all the time. But we look up at it through the enormous atmosphere that surrounds the earth. Though it seems like an airy nothing, it is made of gaseous atoms and molecules, mixed with vapor, misty moisture and a vast assortment of dusty debris. True, these are very fine particles. But they are large enough to sever the sunbeams and force them to reveal their concealed colors.

A sunbeam is a package of white, or invisible, light pulsing along on different wavelengths. As it comes down through the air, some of its wavelengths are bent and scattered to show their hidden colors. During the day, when the sun shines more or less straight down from above, the short wavelengths are bent. They color the sky blue. At evening, when the sun is low in the sky, its beams slant through a thicker layer of the atmosphere. This scatters the longer wavelengths of light‑‑and they add their gorgeous colors to the sunset.