Singularities aren't the only theoretical objects with zero volumes. Non-orientable geometrical shapes also have zero volume(due the sheer fact that at least one dimension is infinite). A mobius strip is a non-orientable 2D object in 3D space. A klein bottle is a non-orientable 3D object in 4D space(with a 2D surface). That gave me a thought that seems rather shocking. I'm no mathematician. But what if the universe was one gigantic klein bottle? What if the universe was feeding itself? To get an idea of what I'm talking about, here is a klein bottle.