Sometimes we look for confirmation in nature and get a surprise.
The essence of the story, as usually told, goes something like this. In the fall of 1901 J.B. Watson, Chief Engineer at the Tamarack copper mine (S. of Calumet, Mich.) suspended 4250 foot long plumb lines down mineshafts. Measurements showed that the plumb lines were farther apart at the bottom than at the top, contrary to expectations. Thus arose one of the long-standing mysteries of science. [More]
The possible explanations include: the Earth is actually a hollow sphere and we live on the inside surface.
The serious explanations are much, much more complicated.
Warning: geometry involved.