This is wrong. General Relativity tells us exactly how mass (or rather energy) affects spacetime. This has nothing to do with relative distances. The issue with

This is wrong. General Relativity tells us exactly how mass (or rather energy) affects spacetime. This has nothing to do with relative distances. The issue with wormholes and warp drives in general relativity is that they require weird forms of energy that we know exist in quantum mechanics, but may not work on macroscopic scales.