Hi Vic, On 18 Aug 2011, at 10:36, Vic Marriott wrote:
> > 2. At dusk, the Sun shows at 290º. This can't be correct as EGKA is > at 50.50º north. I would expect the Sun to be below 270º. > http://i.imgur.com/cd9Ub.png > The compass direction of the sunset's location is actually more related to the time of year then it is related to latitude. In Nothern hemisphere summer, the sun always sets north of the 270 degree line, while in wintertime it's south. The amount of deviation is related to how far north / south your are, which is in turn related to the amount of seasonal daylight time variation that occurs as a function of latitude. I currently don't have time for a lengthy explanation, but the 23 degree tilt of the earth's rotation axis with respect to the sun is of key importance here. When you go far enough north, the location of sunset will touch the 360 degree line on June 21; in other words the sun touches the horizon due north. That latitude is known as the arctic circle. If you go even further north, the sun will no longer set (in summer time), and keep moving all the way through the northern hemisphere, hence causing the midsummer night daylight. I'm happy to explain the process in more detail as soon as I have more time. Cheers, Durk ------------------------------------------------------------------------------ Get a FREE DOWNLOAD! and learn more about uberSVN rich system, user administration capabilities and model configuration. Take the hassle out of deploying and managing Subversion and the tools developers use with it. http://p.sf.net/sfu/wandisco-d2d-2 _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
