Assertion: curvature's curvature | /r/HasProperty | visible
Facets:
value: at any altitude
type: LOCATION
Source sentences:
text: The curvature of the Earth is visible at all altitudes, including sea level, as long as the surrounding terrain is smooth.
text: At high altitudes, the curvature of the Earth is much more obvious, of course, but the curvature is visible at any altitude.