Tuesday, July 27, 2010

parhelion


A sun dog or sundog (scientific name parhelion, plural parhelia, for "beside the sun") is a common bright circular spot on a solar halo. It is an atmospheric optical phenomenon primarily associated with the reflection or refraction of sunlight by small ice crystals making up cirrus or cirrostratus clouds. Often, two sun dogs can be seen (one on each side of the sun) simultaneously.

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synanthrope

 A synanthrope (from ancient Greek σύν sýn "together, with" and ἄνθρωπος ánthrōpos "man") is an organism that evolve...