Static in motion

摘要

Wind-blown desert sands can charge up spontaneously. But although sand flow and the forces on charged bodies are well studied separately, surprisingly little is known of what happens when the two combine. The strange things that happen when granular media and electrostatic charge mix have long exercised the minds of both scientists and engineers. In the latest episode in this saga, Kok and Renno, writing in Physical Review Letters', focus on how static charges affect the aeolian - wind-borne - transport of sand. As the basic ingredient of sand encroachment and dune motion (Fig. 1), this is a process of more than academic interest, with implications for desertification and coastal management.