Visible Effects of the Invisible

This exhibit is a variation on the "Kundt's Tube" experiment done by almost every college student. A long tube partially filled with kerosene is stimulated with sound from a speaker at one end. At certain frequencies (the fundamental and its harmonics) the liquid in the tube will squirt up forming fountains at the antinodes in the tube. The higher the frequency, and hence harmonic, the more fountains form. This is a spectacular demonstration of resonance in a pipe.
This exhibit also demonstrates nonlinear behavior: wave patterns and wave formations follow definite principles, yet the latter is the result of chaos; the drop patterns of the waves are more chaotic still.