What is the Hollow Earth theory?

An example of a concave hollow Earth. Humans live on the interior, with the universe in the centre

  Amongst many theories the world has come across, there is one known as the Hollow Earth Theory. The Hollow Earth theory states that the planet earth is completely hollow from inside. In other words, it consists of unknown interior space. This theory was first proposed by Edmond Halley who was already … Read more