Forced harmonic and chaotic rotational oscillations - Recording with CASSY

To investigate the transition between forced harmonic and chaotic oscillations, the linear restoring moment acting on the torsion pendulum is deliberately altered in the experiment P1.5.3.4 by attaching an additional weight to the pendulum. The restoring moment now corresponds to a potential with two minima, i.e. two equilibrium positions. When the pendulum is excited at a constant frequency, it can oscillate around the left minimum, the right minimum or back and forth between the two minima. At certain frequencies, it is not possible to predict when the pendulum will change from one minimum to another. The torsion pendulum is then oscillating in a chaotic manner.