# gst: the 'memory' of a friction

<< Contrary to what you may have learned in high school, friction between two surfaces is not constant. For a wide range of materials and surface types, it increases with time, as microscopically uneven surfaces deform and come into closer contact. Experiments now find an additional wrinkle: friction can have a memory, meaning that it can depend not only on the current state of the interface but also on how it got there. The findings hint at connections between friction and the behavior of glasses and other disordered systems and, in the long run, may influence how scientists think about friction associated with earthquakes, industrial machinery, and micromachines. >>

David Lindley. Focus: Friction Remembers Its Origins. Physics 11, 55. Jun 1, 2018

https://physics.aps.org/articles/v11/55