A

David

Darling

quasiperiodic

The term 'quasiperiodic' refers to a form of motion that is regular but never exactly repeating. Quasiperiodic motion is always composed of multiple but simpler periodic motions. In the general case, for motion that is the sum of simpler periodic motions, if there exists a length of time that evenly divides the frequencies of the underlying motions, then the composite motion will also be periodic; however, if no such length of time exists, then the motion will be quasiperiodic.