over time, eventually going through the full range of angular momentum from L = LMAX, to a straight line L=0, to the initial orbit in the opposite sense L = -LMAX. The time period of the oscillation in angular momentum (the time to complete the trajectory in figure 8), almost exactly matches the quantum mechanically predicted period for the wavefunction to return to its initial state, demonstrating the classical nature of the Rydberg atom. See also Heavy Rydberg system Old quantum theory Quantum chaos Rydberg molecule Rydberg polaron References Atoms Atomic physics