Spheres of influence - Umberto Eco on why we should beware mad scientists

There are two hollow earth theories. According to the first one we live on the crust, but there is another world on the inside where lies - some say - the realm of Agartha, the home of the King of the World (see, for example, the fantasies of French philosopher René Guénon). The second theory has it that while we think we live on the outer crust, we actually live in the interior (on a convex surface instead of a concave one). more...