Physicists describe rainbows based on the [[refraction]] and multiple [[reflection]]s of sunlight in droplets of [[water]]. Though appearing semicircular from the ground, rainbows are actually circular. Rainbows appear when water droplets are lit by direct sunlight, a condition that rarely occurs ''during'' a [[storm]], because the [[cloud]]s block the [[sun]]. Rainbows are frequently seen ''after'' a storm, when the falling rain has moved into the distance and the sun is roughly behind the observer when the observer is facing the patch of rain. | Physicists describe rainbows based on the [[refraction]] and multiple [[reflection]]s of sunlight in droplets of [[water]]. Though appearing semicircular from the ground, rainbows are actually circular. Rainbows appear when water droplets are lit by direct sunlight, a condition that rarely occurs ''during'' a [[storm]], because the [[cloud]]s block the [[sun]]. Rainbows are frequently seen ''after'' a storm, when the falling rain has moved into the distance and the sun is roughly behind the observer when the observer is facing the patch of rain. |