for simulating gravity in particular you can do one better, since a sphere is in turn gravitationally indistinguishable from a point mass due to the https://en.wikipedia.org/wiki/Shell_theorem#Force_on_a_point...
replyThis deserves a simulator
replyand you can do one better than that - Birkhoff's theorem, the relativistic analogue of the shell theorem.
replyhttps://en.wikipedia.org/wiki/Birkhoff%27s_theorem_(relativi...