The most important objects in this slide are, from top to bottom, a point light source, a mechanical wave driver and wave source, a ripple tank, and a digital wave generator. The mechanical wave driver moves the point or linear wave source up and down on the surface of the water in the ripple tank. This creates circular or linear ripples or waves. The frequency setting selected on the digital wave generator determines the wave frequency.

An image of the ripples in the tank can be seen on the table top beneath the ripple tank. Light from the point source passes through the water in the ripple tank. A wave peak on the surface of the water acts as a focusing or convergent lens and produces a bright area in the ripple tank image. Wave peaks appear as bright areas in the image. A wave trough in the water acts as a divergent lens, and produces a dark area in the image. In the movies that follow, you will see close-ups of ripple tank images that illustrate a variety of wave phenomena.