If our earth were a hollow sphere(unlike the filled sphere as it is now) and we are made to live 'inside' it, then I guess we do not feel any gravity on us...we will just be wandering like astronauts in a space station..Is my assumption true (or do we feel gravity??)some confusions here..as per Einstein's theory, mass curves the space-time regardless of whether you are inside or outside, the mass here is the walls of the sphere so we would be bound to the walls...but as per Newton's theory the 'center' attracts so we would be bound to the center...(does a hollow sphere have a center?)then how can two objects say our hollow earth and ourselves have a common center of gravitation???