I've read more than one piece of sci-fi where some sort of wormhole transport technology can only function far away from the gravitational fields of planets, but is revealed also to function anywhere the gravitational potential field has a zero gradient: at Lagrange points or even at the centres of planetary bodies. I wonder, though, is this plausible? I assumed at first that the requirement to be far away from planets was so as to be on a relatively "flat" area of space where there's negligible variation in the gravitational force acting on different parts of a large structure. However, I do not think this would work for Lagrange points. It seems to me they would be just as bad as (or maybe worse than) the supposedly bad areas in orbit. But (given our current understanding of physics) could a physical phenomenon be sensitive to the gravitational potential gradient? After all, there's nothing fundamentally distinguishable about being static in no gravitational field and free-falling in a constant field, is there?
And yes, I know we need some sort of new physics to create and dispose of these convenient wormholes in the first place. You can just say it's fiction and that's the way it works. But it's clearly supposed to be pretty similar to the physics we understand, and I wonder what those more versed in physics think of all this.