August 26

crepuscular rays Photo Credit: Stefan Klocek [CC BY-NC 2.0] via Flickr

Image of the Day

Crepuscular Rays

Crepuscular rays are beams of light that originate from the sun and appear to radiate out across the sky, often through a layer of cloud.

These sunbeams are, in fact, nearly parallel; however, due to linear perspective (the same optical effect that make train tracks appear to converge in the distance), they appear to diverge as they get further from the sun. Particulants in the air reflect and diffract the light from the sun and the shadows from the clouds, which makes the rays particularly visible near sunrise and sunset.

Rays that create a similar effect but that appear opposite the sun in the sky are called anticrepuscular rays.

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