@coluber2001,
Around 1900 the Koreshan Unity
founded the community of Estero, Florida, a utopian community a little bit south of Fort Myers. These people believed that the earth was a gigantic sphere containing the universe, and that we lived on the inside surface of the sphere with the sun in the middle. I suppose this would've been easy enough to disprove by pointing a telescope up and seeing Stars rather than the Earth.
Curiously enough astrophysicist Freeman Dyson proposed a theoretical sphere called the Dyson Sphere, an enormous hollow sphere built around a small sun, and people would live on the inside surface. Of course there would be enormous problems to overcome, such as the lack of gravity and atmosphere and the dangerous ultraviolet rays of the Sun. At any rate it's fun to think of it, and in one episode of Star Trek: The Next Generation the ship was trapped inside a Dyson Sphere.