Conveniently it isn't quite high enough to say that you can see the full curve.
You'd have to put it in 4-dimensional space to see the full curve. You can't do that without seeing the entire surface at one time. You can see the curvature, however.
The point is, that there are many, many ways to test the curvature of the Earth, and they all end up showing that it's round.
One interesting way was by Eratosthenes, about 300 BC. The studies of Aristarchus showed that the Sun was extremely far away, so the rays of the sun would be effectively parallel viewed from the Earth.
So, on the same line of longitude, the difference in angles of the sun, seen at two different places, would give the amount of curvature between the two locations. Eratosthenes used this method to come up with a remarkably good estimate of the Earth's size.
So, we have pictures (film, video, and digital images ), the mariner's observation that we see distant mountains on coastlines top first, and lower levels as we get close, Coriolis effect, Eratosthene's measurement, and this interesting one:
Rowbotham repeated his experiments several times over the years but his claims received little attention until, in 1870, a supporter by the name of John Hampden offered a wager that he could show, by repeating Rowbotham's experiment, that the earth was flat. The noted naturalist and qualified surveyor Alfred Russel Wallace accepted the wager. Wallace, by virtue of his surveyor's training and knowledge of physics, avoided the errors of the preceding experiments and won the bet.[7][8] The crucial step was to set a sight line 13 feet (4 m) above the water, and thereby avoid the effects of atmospheric refraction.[9] Despite Hampden initially refusing to accept the demonstration, Wallace was awarded the bet by the referee, editor of The Field sports magazine. Hampden subsequently published a pamphlet alleging that Wallace had cheated and sued for his money. Several protracted court cases ensued, with the result that Hampden was imprisoned for threatening to kill Wallace[10] and for libel.
https://en.wikipedia.org/wiki/Bedford_Level_experiment
atrol: :cheers: :angel: :angel: :angel: :cloud9:
