Interparticle friction determines hysteresis in granular flow
When tilted downhill, a pile of grain starts flowing at an angle θstart that is larger than the angle θstop at which it stops. That hysteresis is an important feature of the behavior of earthquakes, landslides, and industrial flows. But despite the many years researchers have investigated granular flows (see the article by Anita Mehta, Gary Barker, and Jean-Marc Luck, Physics…