# gst: movers and shaker, the dynamics of granular matter

 << Granular materials are disordered systems often found in a far-from-equilibrium state. >> 

 << You can think of it like a beaker filled with loose sand, (..) At first there are big holes between the grains. So initially, it's easy for a grain to shift position by falling into an empty space. But as these spaces start to get smaller, it becomes less likely that a grain can fall through one. As the taps continue, it takes increasingly cooperative events to create the space necessary for more compaction. >> Stefan Boettcher. 

<< Previous research has shown a similar statistical pattern for the behavior of amorphous solids that don't form ordered crystals when moving from a liquid to a solid state, such as glass and many polymers. >> 

Carol Clark. Movers and shakers: New evidence for a unifying theory of granular materials. Emory University. Jan 08, 2021. 

https://phys.org/news/2021-01-movers-shakers-evidence-theory-granular.html   

Paula A. Gago, Stefan Boettcher. 

Universal features of annealing and aging in compaction of granular piles. 

PNAS. 117 (52) 33072-33076. doi: 10.1073/ pnas.2012757117. Dec 14, 2020. 

https://www.pnas.org/content/117/52/33072