> That’s a bit of a warning signal given that our universe itself is curved. What does this has to do with whether they are a different basis for cases where w

> That’s a bit of a warning signal given that our universe itself is curved. What does this has to do with whether they are a different basis for cases where we don't account for curvature? This seems completely irrelevant, sure the tool can't be used in some cases but it can be used as a basis change in other cases.