Tag: inside the earth

Hollow Earth Theory: Possible or Not?

It was affirmed only about four hundred years ago that the world was flat instead of spherical. The circularity of the Earth was proven by explorers sailing around the globe in the 18th century and by round-the-world flights of the 20th century. In the late 17th century, the possibility of a Hollow Earth was postulated by Edmond Halley in 1692.