A couple of commenters expressed concern over the use of centrifugal force after my rant on the use of the word force. So, what is the deal with these two terms? Are they ok to use? Are they real ...

The frictional forces in a tidal current have been determined from simultaneous observations of the surface gradients and the currents at various depths. The observations were made a few miles from ...

Cold ions sliding across periodic energy-potential patterns formed by lasers have been used to elucidate the physics of dry friction between crystals. Experiments with no more than six ions suffice to ...