Now I get to do something with that force scale I built. I had a request some time ago to talk about friction. Friction is surprisingly complicated. When two surfaces rub against each other, why is ...

Frictional experiment: artist’s impression of the metainterface between a rigid piece of glass (top) and a metasurface (bottom). The textured regions are where the glass and metasurface are in contact ...

Spring technology for damping is relatively old. Stagecoaches had leaf springs, early trains had large, crude, coil-spring buffers (to absorb shocks when cars bumped together) and early automobiles ...