unless they have figured out artificial gravity... none of these pictures or videos make sense. the only way I know how they can add gravity to these quarters i

unless they have figured out artificial gravity... none of these pictures or videos make sense. the only way I know how they can add gravity to these quarters is by spinning them... the "floor" will be the curved sides (or I guess the ends) not the middle of the things? What am I missing here? Edit: oh, they ARE with compromise? no gravity. which makes the name "Gravitics" more than a bit cheeky.