Just as the Earth revolves around the sun, nearly all life upon the Earth revolves around and is dependent upon it. The sun feeds and powers us, its light guided the evolution of our eyes, and it illuminates our myths and metaphors. Even so, it projects damaging ultraviolet radiation, and one day it will expand into a red giant and consume us along with much of the solar system. For the next five billion or so years however, the sun will continue to warm us, regulate our circadian rhythms, and encourage us to spend long summer days at the beach. This issue looks at all the ways we relate to the sun, but also, for contrast, a few of those other lights that shine not from above but from beneath the ground -- the geothermal activity of volcanos, and the luminous colors of crystal growth.