Can perpetual motion be possible in a gravitational field? If I take an object and into space from earth, the potential energy increases but as we go further away from the earth the forces which contribute in the work done decreases, thus it seems to me as if energy is destroyed. Because the kinetic energy of the object is directly supplied by me, the potential energy mgh starts to decrease as we move away from the ground, thus it seems that potential energy is decreasing. Please explain why this reasoning is wrong. Thanks!!!