 The reader of the entry on  absolute and relational space and motion: classical theories  will recall that Newton’s actual aim was simply to show that Descartes’ two kinds of motion are not adequate to account for rotational phenomena. Newton’s bucket argument showed that the effects of rotational motion could not be accounted for by means of the motion of the water relative to its immediate surroundings (the bucket walls); Newton’s thought experiment with two globes connected by a cord was meant to show that one can determine whether they are rotating about their common center (and if so, in which direction) without needing any reference to anything external. By pushing on opposite faces of the two globes and checking for an increase or decrease in the tension in the cord, one can determine in which sense the spheres are in rotation, if they are rotating at all.