To provide a method for propelling a moving body in an inertial space with propellant or centrifugal force not depending on ground friction reaction.

When a pair of weights having mutually reverse rotation are located approximately overlapping each other backward or approaching each other, they are driven to be rotated in the direction of moving one apart from the other, whereby the moving body formed with the pair of weights having mutually reverse rotation is also eventually moved backward with reaction. When the pair of weights is mutually rotated and moved forward in the propelling direction, the pair of weights having mutually reverse rotation produces frontward centrifugal resultant force so that the backward movement of the moving body is stopped and changed into forward movement. When the pair of weights are mutually rotated and moved backward, they produces backward centrifugal resultant force so that forward movement of the moving body is decelerated and stopped and at the same time braking is given to the pair of weights approaching each other in the rotating direction to be slowed down or stopped. The backward rotation control of the pair of weights having mutually reverse rotation results in the moving body to be propelled and moved forward by a backward movement distance or longer.