|Cyrus Reed Teed (Koresh)|
1870 saw the first appearance of a curious variant of the hollow Earth theory outside the literary field. The American Cyrus Read Teed proclaimed his belief that the Earth is hollow, but (here is the difference with previous theories) we live inside. Although the sea surface has been known for over two thousand years to be convex, and in spite of the arguments that led the Greek philosophers to assign the Earth a spherical shape, with ourselves on its outer surface, Teed was convinced that the Earth is really concave. The apparently infinite outer space would be a hollow bubble inside a universe made of rock. Teed changed his name to Koresh and founded a religion (Koreshanity) which reached several thousand followers, although they were scattered after his death in 1908.
Soon after, a German aviator named Bender, a prisoner in France during the First World War, read Teed publications and believed them. Bender developed these theories and asserted that the universe is an infinite mass of rock surrounding a bubble 13,000 kilometers in diameter, in whose inner surface we live. The atmosphere, 60 kilometers thick, thins up to the central vacuum, where three bodies move: the sun, the moon and the ghost universe, a ball of gas with shining points of light: the stars. When the ghost universe passes before the sun, it causes the alternation of day and night in the various regions of the inner surface of the Earth.