I was thinking about this too from the perspective of potentially being easier to observe than ships at sea.
On the other hand, the earth's curvature is imperfectly correlated to gravitational vector. Given a stable gravitational anomaly, would two towers such as that bridge be oriented to gravity or curvature? My guess the former, meaning that the change in distance between the base and top of two tall towers wouldn't add to understanding curvature.
On the other hand, the earth's curvature is imperfectly correlated to gravitational vector. Given a stable gravitational anomaly, would two towers such as that bridge be oriented to gravity or curvature? My guess the former, meaning that the change in distance between the base and top of two tall towers wouldn't add to understanding curvature.