Proper velocity the traveling object. It equals the object's momentum p divided by its rest mass "m", and is made up of the space-like components of the object's four-vector velocity. William Shurcliff's monograph mentioned its early use in the Sears and Brehme text. Fraundorf has explored its pedagogical value while Ungar, Baylis and Hestenes have examined its relevance from group theory and geometric algebra perspectives. Proper velocity is sometimes referred to as celerity. Unlike the more familiar coordinate velocity v, proper velocity is synchrony-free (does not require synchronized clocks) and is useful for describing both super-relativistic and sub-relativistic motion. Like coordinate velocity
Constant linear velocity Constant linear velocity In optical storage, constant linear velocity (CLV) is a qualifier for the rated speed of an optical disc drive, and may also be applied to the writing speed of recordable discs. CLV implies that the angular velocity (i.e. rpm) varies during an operation, as contrasted with CAV modes. The concept of constant linear velocity was patented in 1886 by phonograph pioneers Chichester Bell and Charles Tainter. Laserdiscs, the first consumer optical discs, used constant linear velocity to double playback time (CLV / "extended play" discs can hold 1 hour per side; CAV / "standard play" discs can