If you use toroidal boundary conditions then you could remain in an inertial reference frame and return back to the same pont. See https://en.m.wikipedia.org/w

If you use toroidal boundary conditions then you could remain in an inertial reference frame and return back to the same pont. See https://en.m.wikipedia.org/wiki/Periodic_boundary_conditions https://en.m.wikipedia.org/wiki/Periodic_boundary_conditions