A sunbeam, in meteorological optics, is a beam of sunlight that appears to radiate from the Sun's position. Shining through openings in clouds or between other objects such as mountains and buildings, these beams of particle-scattered sunlight are separated by darker shadowed volumes. Despite converging toward the light source, the beams are essentially parallel shafts of directly sunlit particles separated by shadowed ones. Their apparent convergence in the sky is a visual illusion from linear perspective. This illusion also causes the apparent convergence of the otherwise parallel lines of a long straight road or hallway at a distant vanishing point. The scattering particles that make sunlight visible may be air molecules or particulates.
