The goal for this project is to develop something in SL that supports Harry Shipman’s seasons PBL problem (see http://www.udel.edu/physics/scen102/shadows_of_light/). To keep things less complicated, I’ve decided to ignore both precision and accuracy (LOL!). Or at least high precision and high accuracy in terms of how faithfully solar motions are modeled. . . but enough of the gist to carry out the lab at the level it was intended will be there. I do plan to program in the axial tilt of the earth (http://en.wikipedia.org/wiki/Axial_tilt) and hopefully solar positions from a few latitudes. Looks like the best way to do this is simply to use several parts that rotate about axes independently. The current idea is to have a floor that tilts to a max of 23 degrees up or down and a solar sphere that can shift starting position over the horizon based on season/latitude selected and then rotate around an axis. Much simpler than the original plan (to use web-data and some kind of polar coordinate something!). Am reading about rotation on the LSL Wiki (http://rpgstats.com/wiki/index.php?title=Rotation#Rotation). Shouldn’t be hard to do something that is menu-driven.