Pendulum wave: patterns from oscillations
Eight pendulums of different lengths swing together: first a travelling wave, then chaos, then order again. A 3D experiment for kids 9+.
3D
Age 9+10 min
OscillationsWaves & phase3D scene
Loading simulation…
Drag to orbit the scene, scroll to zoom. Press “Run”.
What the experiment shows
The lengths are chosen so that in 30 seconds each next pendulum makes one more swing than the previous one. The phases drift apart and come back together.
How to run it
- Press “Run” and watch the balls from the side.
- Look from above: the balls trace a sine curve.
- Change one pendulum’s length — the pattern breaks.
Questions to discuss
- Why does a long pendulum swing slower?
- When will all the pendulums line up?
The science
A pendulum’s period T = 2π√(L/g) depends only on its length. Different periods give different frequencies and their beating makes a travelling wave and patterns.
Try it at home
Hang weights on strings of different lengths and set them swinging together.
What to change in the editor
- Add a ninth pendulum.