We had a project in PHYC 2050 to write an applet simulating a scientific model. Me and my partner chose the solar system, which was a step up from the other projects (ideal gas law, refraction ). We took into account inter-planetary actions and used a simple "assume force is contant for time t and advance the system" algorithm. It appears to overestimate on average, but it had the best usefulness to "we can do this" ratio. In any case, check it out at: myweb.dal.ca/cr376499 The 2d version is the project we submitted and the 3d version is just me wanting to make it 3d. It already did all the z coordinate calculations so it was just a matter of drawing them. Special thanks goes to tony873004 (from here) who told me about the JPL horizons system so we could get our hands on the position and velocities of planets.