What this comes to mind is the layers of reality. Forces/pressure coming from the nature of whats in, the composition, and forces and pressures coming from beyond or outside that which is being forced. Results in different layers of stability, where as we can see if a frequency of disturbance is created for a period of time in an area, according to the nature of that which is being disturbed, will react in some physical accordance to the outer force. Thus from the vibrated plate the sand is sitting on, urges the sand to take shape of the mathematical frequencies in time the plate vibrated. Brings to mind how radio waves can carry information. Or how music is frequency of vibrations creating geometric vibratory patterns of air, which your ear and brain mechanism can detect and compare.