We have already seen that HPMOR!magic can break the conservation of mass (Transfiguration of objects of various mass such as a canteen of frozen water into a large rocket engine, Animagus), conservation of momentum (’Arresto Momento!, broomsticks (apparently), telekinetics) etc.
True, but those were local violations. It was not stated that General Relativity must fail for magic to work, at least I don’t recall it. Also an occasional discussion of Quirrell communicating with one rather distant object would look differently if FTL is explicitly OK.
We have already seen that HPMOR!magic can break the conservation of mass (Transfiguration of objects of various mass such as a canteen of frozen water into a large rocket engine, Animagus), conservation of momentum (’Arresto Momento!, broomsticks (apparently), telekinetics) etc.
True, but those were local violations. It was not stated that General Relativity must fail for magic to work, at least I don’t recall it. Also an occasional discussion of Quirrell communicating with one rather distant object would look differently if FTL is explicitly OK.
What do you mean by local variation. How do you know time turners aren’t also just local variations?