Friction may well be nature’s most useful phenomenon. Without it, walking would be impossible and there would be no belt drives, no clutches, no wheels, and no brakes. However, in machinery in which ...

Without the force called friction, cars would skid off the roadway, humans couldn't stride down the sidewalk, and objects would tumble off your kitchen counter and onto the floor. Even so, how ...

TimesMachine is an exclusive benefit for home delivery and digital subscribers. About the Archive This is a digitized version of an article from The Times’s print archive, before the start of online ...