Adding power...

[iacob alex]

...from the "empty" space , due to a rotational pull effect (variable/increasing rotational inertia ) , at :
  http://www.evert.de/eft294e.htm
  A well known , common and old application is the variable arm throwing of a mass with hand or with a counter weighted gravity simple machine (let's say a trebuchet...).
  If we use this natural property of a free rotating mass on a spiral trajectory , we can solve the single "critical " (top) point , to "remake" the starting unbalance of a simplified two masses configuration.
    Al_ex