The phrase ‘granular material’ is used to describe a large number of discrete solid, macroscopic particles that lose energy whenever the particles collide. One might naively imagine that such systems would exhibit similar behaviour to traditional fluid and solid mechanics. However, we present two problems that superficially appear to be extremely simple but yield surprisingly rich dynamics that have no analogue in traditional mechanics. First, we consider a dilute stream of particles that collides with an oblique planar wall. Second, we show several surprising phenomena that occur in an extremely simple system of a single frictionless, inelastic, spherical particle falling under gravity through a symmetric funnel.
This video was produced by the Sydney Mathematical Research Institute, as part of their SMRI seminar series.
