The Physics of Mud and Hair Gel

Watching things dry isn’t always the most enlightening project, but researchers publishing in the September Physical Review E have discovered some new twists to the drying process. They created three different simulated soils by mixing tiny glass beads with clay or gel and used magnetic resonance imaging (MRI) to watch as the water evaporated from the samples. The results point to the properties of the pasty material between the beads as the dominant factor determining the drying speed, an important soil property for farmers. The team also speculates that slower-drying material could be added to real soil to help it retain moisture.