A bicycle wheel is suspended from one of end of its axie by a rope, and spun up by hand. The wheel's axle is then placed horizontally and the free end of the axle processes about the supported end.

The gyroscope seems to defy gravity because the torque created by the spinning wheel counteracts the torque due to gravity. Read more about gyroscopes here. Gyroscopes have been used through history for varied uses such as stabilizing spacecraft or for guidance systems on ships and missiles.