Current research efforts are exploring these and other questions through experiment and computer simulations. In particular, we are interested in studying the intervals between successive avalanches in a model sand pile. The experimental apparatus shown here consists of an aluminum trough filled with sand which is vibrated by a piezoelectric oscillator. The result is a uniform rate of sand falling from the trough into a plexiglass cell in which the pile accumulates.
Light shining on the cell is blocked by the sand pile until an avalanche reduces the pile height.
An increase in current through a photocell positioned on the opposite side of the cell is the signature of an avalanche. We track the intervals between avalanches by recording the current in the photocell as a function of time.