When we create a virtual world for modeling, simulation & training, does it matter if we use a “round-earth” coordinate system and 64-bit precision in our coordinates? Yes, but much more so in some circumstances than others.
Let’s start with the basic concepts. We all know that the world is round, well round-ish, but most of the time we can’t see the effect. When you stand on a rise and look into the distance it’s the shape of the topology that dominates your view. You can’t really see the curvature of the earth.