Well, I've made a solar system simulator before. Nothing great, but it was sufficient to convince me that is just a matter of perspective. The "law of physics"

Well, I've made a solar system simulator before. Nothing great, but it was sufficient to convince me that is just a matter of perspective. The "law of physics" used was: d = sqrt(dx^2 + dy^2 + dz^2) F = G*m1*m2/d^3 That would just be summed up over all the objects included in the system. However, when visualizing the results, I could set (0,0,0) wherever I wanted. I could put it at the solar system barycenter, I could put it at the center of the sun, I could put at at the center of the galaxy (this leads to interesting vortex-like trails...), or I could put it at the center of the earth. The easiest was actually to use the solar system barycenter on an arbitrary date.