Nonaxisymmetric instability of water drop: Skylab

Abstract

Rotating stars with viscosity are unstable to a bar mode after the radio T/|W| of rotational kinetic energy to gravitational binding energy exceeds about 0.14. An analogous instability can be seen in water drops where surface tension replaces gravity. In this Skylab demonstration, an astronaut spins up free-floating drops of liquid beyond their instability point. Ultimately a drop fissions, in what may be the analog of the formation of close binary stars.