  A `star drop' refers to the patterns created when a drop, flattened by some
force, is excited into shape mode oscillations. These patterns are perhaps best
understood as the two dimensional analog to the more common three dimensional
shape mode oscillations. In this fluid dynamics video an ultrasonic standing
wave was used to levitate a liquid drop. The drop was then flattened into a
disk by increasing the field strength. This flattened drop was then excited to
create star drop patterns by exciting the drop at its resonance frequency.
Different oscillatory modes were induced by varying the drop radius, fluid
properties, and frequency at which the field strength was modulated.
