"This is an acoustic levitation chamber designed and built in 1987 as a micro-gravity experiment for NASA related subject matter. The 12 inch cubed plexiglas Helmholtz Resonant Cavity has 3 speakers attached to the cube by aluminium acoustic waveguides. By applying a continuous resonant(600Hertz) sound wave, and by adjusting the amplitude and phase relationship amongst the 3 speakers; I was able to control levitation and movement in all 3 (x,y,z) axis of the ambient space.
This research was used to show the effects of micro-gravity conditions that exist in the space shuttle environment in orbit, but done here on Earth in a lab." Amazing stuff.