Refraction. You are looking at the sun throught the outskirts of a spherical lens, and to complicate things further the lens has a graded index because of gradients in pressure and humitity. Just before you see the sun set it is actually already behind the horizon but the lens made by the athmosphere bends the light slightly aorund the "edge".
You can see at lot of strange things happen, especially in warm air over warm water when the athmosphere has layers of air with different refractive indexes. The most famous is the "green flash", when you suddenly see a part of the sun disk turn green. DagT > fra: "Rob Studdert" <[EMAIL PROTECTED]> > dato: 2005/09/26 ma AM 09:46:21 CEST > til: [email protected] > emne: Distortion low on the horizon > > Does anyone know the technical reason that the sun renders as an ellipse when > shot close to the horizon? > > TIA. > > > Rob Studdert > HURSTVILLE AUSTRALIA > Tel +61-2-9554-4110 > UTC(GMT) +10 Hours > [EMAIL PROTECTED] > http://members.ozemail.com.au/~distudio/publications/ > Pentax user since 1986, PDMLer since 1998 > >
