Tidal disruption even occurs when a star approaches too close to a massive object that it is torn apart by gravitational tidal forces. As a simple model we could consider a scenario where the disruption does not alter the energy and angular momentum of the incident star, but only scatters its material along the trajectory of the centre of mass. According to Newtonian dynamics, the particles will just move on the Keplerian trajectory like beads on a wire. However, when general relativistic effects become important, then the particles will slowly alter their trajectory due to precession. Two particles on slightly different trajectories can collide, and this collision can cause energy dissipation.