 The removal of a large fraction of the mass of the dynamically cold population is thought to be unlikely Neptune's current influence is too weak to explain such a massive "vacuuming", and the extent of mass loss by collisional grinding is limited by the presence of loosely bound binaries in the cold disk, which are likely to be disrupted in collisions.Instead of forming from the collisions of smaller planetesimals the larger object may have formed directly from the collapse of clouds of pebbles.The size distributions of the kuiper belt objects follow a number of power laws.