Phys. Rev. Focus25, 20 (2010) – Published May 28, 2010
Drops of water striking a bed of grains can leave a wide range of crater shapes and sometimes a bigger impression at low and high impact speeds than at medium speeds. The work may help geoscientists identify ancient formations.
Directed percolation, a class of nonequilibrium phase transitions as prominent as the Ising model in equilibrium statistical mechanics, is realized experimentally for the first time, after more than fifty years of research.
Scaling laws are a useful way to characterize fluid flow over a wide range of flow rates and experimental conditions. Theorists now explain several earlier experiments by finding a scaling law that describes how a liquid-liquid interface changes shape when driven by viscous forces.