Chladni Plate

The Chladni plate demonstrates modes of vibration. A metallic plate is being vibrated and we have placed small grains of white sand on the surface to allow you to visualized the motion. Where the sand is not moving corresponds to nodal curves of the vibration. Some experimentalists vibrate the plate from the side using a bow. Here we attached the plate to a mechanical vibrator that we control with a function generator (thus causing a node at the center where the plate is attached).

Here is a video produced by NPR that includes some of our work on the Chladni Plate demo:

Here is an example with a guitar-shaped plate:
Here is a beautiful video demonstrating modes (and transitions between modes) for a rectangular plate from the UCLA Physics department: Using Fourier Series we can understand general vibrations of the surface as temporal superpositions of these fundamental modes (e.g., found using separation of variables).