Related Experiment Video
Updated: Jun 21, 2026

Oscillation and Reaction Board Techniques for Estimating Inertial Properties of a Below-knee Prosthesis
Published on: May 8, 2014
Experimental demonstration of classical Hamiltonian monodromy in the 1:1:2 resonant elastic pendulum
N J Fitch1, C A Weidner, L P Parazzoli
1JILA and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA.
Abstract:
The 1:1:2 resonant elastic pendulum is a simple classical system that displays the phenomenon known as Hamiltonian monodromy. With suitable initial conditions, the system oscillates between nearly pure springing and nearly pure elliptical-swinging motions, with sequential major axes displaying a stepwise precession. The physical consequence of monodromy is that this stepwise precession is given by a smooth but multivalued function of the constants of motion. We experimentally explore this multivalued behavior. To our knowledge, this is the first experimental demonstration of classical monodromy.
Related Concept Videos
Simple Pendulum
The period of a simple pendulum depends on two factors: its length and the acceleration due to gravity. The period is completely independent of any other factors, such as mass or maximum displacement. For small displacements, a pendulum is...
Torsional Pendulum
As long as the rigid body's angular displacement is small, its oscillation can be modeled as a linear angular oscillation. The amplitude of the oscillation is an angle. The role of mass is played by the...
Physical Pendulum
When dealing with complicated systems, the mass moment of inertia is an important parameter, as it describes the mass...
Concept of Resonance and its Characteristics
Forced Oscillations
Real-World Applications of Power Series

