No, momentum is conserved, that is one of the fundamental laws of physics, right up there with the conservation of energy. In the beginning, the OMFG particle i

No, momentum is conserved, that is one of the fundamental laws of physics, right up there with the conservation of energy. In the beginning, the OMFG particle is at rest, and the protodisk particles orbit symmetrically around the center of the protodisk, for a sum total momentum of zero.