Strange things happen in the gathering dusk.

If you've ever watched the lazy summer sun redden as it sets below the horizon, you might have thought you saw it growing larger and larger as it approached the ground. A few people claim they've seen a brilliant green flash as the top of the sun dipped out of sight. More common are reports of light pillars shooting straight into heaven just before the sun disappears.

Wrapped up in these strange phenomena is a curious combination of fact and myth—though quite possibly not in the combination you imagine. Most people believe that the green flash is a myth, but we've got the pictures to prove it. And the idea that the sun gets fatter and larger as it sets is flat wrong. Certainly, it seems to; but what really happens involves some relatively simple atmospheric science and, to keep things interesting, a strong dose of illusion and a dash of mystery.