We have geodesics for that.
If anyone wants to grasp the basics: here is some fun reading (leading on to some beautiful math). Changing the idea of parallelity leads to hyperbolic geometry and other fun stuff. :)
We have geodesics for that.
If anyone wants to grasp the basics: here is some fun reading (leading on to some beautiful math). Changing the idea of parallelity leads to hyperbolic geometry and other fun stuff. :)