Warp factor (symbolic abbreviation wf), alternatively known as time warp factor, is a unit of speed. Another common abbreviation is "warp". The value is given after the unit ('''Warp Factor ''' 5, or Warp 5). The increase in warp factor speed values corresponds to a non-linear increase in actual velocity. The most common usage is to describe the speed of a spacecraft traveling at a faster than light speed, using a warp drive. Sublight speeds can also be measured in warp factor values, such as "warp .5". Since warp drive was first used by Zephram Cochrane in 2063, two methods of scaling warp speeds have been used.