So I'm wondering, should I use Cartesian or Polar Coordinates to store intergalactic objects in DB? I'm currently prototyping a game idea that can be oversimplified as a space ship simulator in infinite space. I'm considering grouping objects together so that they have a "parent super-space" as follows: A cluster would be an object where the parent space is the universe. A galaxy's parent space is a cluster. A solar system's parent space is a galaxy. A star/planet's parent space is a solar system. Any other smaller object would occupy the sub space of any of the above. For example, if a planet left a solar system, then it would be in the galaxy's subspace. The user will be able to fly their ship anywhere they feel like. My reasoning for this is that I think it would be a lot harder to maintain the illusion of "real enough gravity" if things were stored in Cartesian coordinates. I think there would be a draw back in calculating distances between 2 game objects, but if they are not in the same subspace then I could probably just estimate with the distances between their subspaces. Would you pick Cartesian or Polar coordinates for this kind of project?