Tuesday, November 17, 2009
We've all seen them...my friend Donald calls them "God Lights". The the rays of sunlight that seem to radiate out from the sun through breaks in the clouds are more properly known as "crepuscular rays". We see them because sunlight is scattered by dust and other particles in the atmosphere making the air lit by the sun appear brighter than the air that is in the shadow of the clouds. Though the rays are virtually parallel to each other, perspective causes an apparent convergence toward the Sun in the same way parallel railroad tracks seem to converge in the distance.
This image of some bright crepusculars was made late one afternoon in Bedford, NY. Note the particularly dark shadow on the right side of the photo, also parallel to the light rays, cast by the clouds there.