How can space be curved and expanding when there is nothing outside of space to be expanding into? and everything that has a shape has a solid form outside of it holding it into that shape. so how can space be cuved with nothing outside of it holding it into that shape? now i understand that the big bang theory pushed everything outward. but space is the black stuff. space had to be there in order for the big bang to happen. the molecules and atoms had to have somewhere to go so i think that space existed before the big bang. but i still dont see how space itself can be expanding and in a curved shape...