?? It's a plot point that they don't occupy the same space though the collision of phases and the resulting sparks and sprays in the surface world says hi the religious phases = / = the phases that occupy the surface world either (including the main phase that the story mostly takes place in) unless we want to call the entire cosmology of To Aru/the Tree of Sephiroth a "universe", which is.... questionable, to say the least:char