Toshiko Sato developed the Rift equations to serve as guidelines to operate the Rift Manipulator. Out of all of the Torchwood Three team, Tosh seemed to have the greatest understanding of how to operate the machine, with the possible exceptions of Jack Harkness (TV: Captain Jack Harkness [+]Loading...["Captain Jack Harkness (TV story)"]) and John Hart, (TV: Exit Wounds [+]Loading...["Exit Wounds (TV story)"]) who had both come from a more technologically advanced time.[source needed]