> That all of earth is round, comes not from direct observation (except for the very few people who have been in space).
or anyone who's been in a plane?
or anyone who's been in a plane?
I mean, I just checked, it seems under ideal conditions one could see the curvature of earth at 10.5 km height, but to me it was not really a convincing curvature last time I did a long flight. Your experience was different?
The curvature of the earth can be quite apparent on a clear day at that altitude when flying over water. Or the midwestern US.