I've... never heard that before. Moreover, it doesn't work on Venus or Mars -- Mars has a year that's twice as long as ours, but it's axial tilt and day length are nearly identical to Earth's. Venus's day is longer than its year and the number given is not only wrong, but unphysical (greater than 180°). As far as I know, it's arbitrary -- with a bias towards things mostly spinning close to straight up, and not so much down or sideways. -- Rebecca Harbison >> From Dzur Mountain (which is about as far north as any jungle or >> other >> tropical condition is attributed) to the North Sea north of Fenario >> (Brokedown Palace describes the bitter cold of the north sea) >> appears to > be >> about 2,800 miles, and if the planet is the same size as the >> Earth, that >> works out to be about 41 degrees of latitude between the tropics >> and the >> arctic. > > The "axial tilt" number I'm using is from the Small Invisible > Lights site, > which gave a formula for calculating it as > > Seconds in a Day/Days in a year = Axial Tilt * 10 > > For Earth this works out as (24*60*60)/365 = 23.67 * 10 > For Dragaera is works out as (30*60*60)/289 = 37.37 * 10 > > I haven't been able to confirm that this formula is correct, > however, and > I can't quite wrap my head around why this works. It seems to me > that the > rotational speed of the planet may have very little to do with its > orbital > speed, if the planet has undergone some kind of event to dramatically > affect it's rotation (such as Venus).