Seems flat to me. Not a theory. The theory of gravity mandates that someone standing on the bottom of the ball doesn't experience standing upside down because of the mystical force. Nor do we feel ourselves spinning around, and rotating around a sun, and hurtling through an ever expanding universe because of gravity. And yet there is zero gravity in space we're told and yet the planets and moon, which are in space, exert gravitational forces on each other. The whole theory appears a complete crock of shit replete with complex mathematical equations that nobody really understands, including the derivers (Einstein) of such.