Alcubierre's Paper - Is There a Way to Arrange Space?

Einstein's equations go in one direction. They say, if you have this arrangement of mass and stuff in the universe, what is the shape of space around it? Cool. And then how does things move in that space? What they don't do is tell you, if you want a certain shape of space, how do you build it? Alcubierre just said, well, is it possible to have this shape of space? And Einstein's equations say, yes, that would satisfy the equations,. But it doesn't tell you how to arrange stuff in the world to make space do that. That might be impossible.