There is a common demonstration where one places a double cone (object where two cones are together at their bases) at the bottom of a v-rail system at an incline. Left to rest, this double cone will move along the rails as if ascending the incline. Of course, gravity is not defied here. The truth is that the center of mass is at a decline and gravity is pulling it down. The mathematical description of this demonstration was investigated and we then built several models of these cones, including inverting of the system. I plan to write more, but this is just for start.