The dynamics of rigid bodies. This topic is a substantial branch of Newtonian mechanics and the starting point for the analysis of rotating systems (such as nuclei and molecules) described by quantum mechanics. There are many technological applications of rigid body dynamics, including gyroscopes, robotics, and artificial satellites in space. The rotation of the earth has been analysed in terms of rigid body dynamics, with the extent to which the earth is not a rigid body being of fundamental importance in geophysics.