The Cornell Ranger has set an unofficial world record.  It has walked for just over 5 and a half miles.  It made 45 laps around the Barton Hall track at Cornell University.  The Ranger’s creators wanted to demonstrate the robot’s efficiency.  Instead of using traditional motors to power its movement, the Ranger relies on the force of gravity when swinging its legs out–more like a human.  A pair of outside and a pair of inside legs swing alternatively resulting in a walking movement.  Its legs are unjointed, but the feet can be tipped up and down with the help of an ordinary hobbyist’s remote control.