A cook’s reaction to cockroaches in the kitchen is a good approximation of a physicist’s reaction to friction: not only is it undesirable, it is hard to get rid of. OK, our analogy falls at a last ...

Friction is an intrinsic physical phenomenon to curling. Without it, objects in motion would move endlessly, without slowing down. This would cause many safety-related problems: Cars or trains could ...

A simple one-piece sleeve is sometimes better for reducing friction than complex rolling-element bearings. Besides being greaseless, journal bearings can be made out of high-tech plastics for weight ...