Faraday Jar
The Faraday Jar produces Faraday wave patterns on the surface of a small amount of alcohol. The jar of alcohol is resting on a transducer which vibrates the liquid. The frequency and amplitude of the vibrations are carefully controlled by a voltage control oscillator and the wave shape can be either triangle for sinusoidal. Faraday patterns appear at certain frequencies and the pattern depends on both frequency and amplitude.