After the fall

THE BRIGHT red robot lay sprawled across the threshold, seemingly unable to go on. Chimp, built by Carnegie Mellon University's National Robotics Engineering Centre (NREC), had successfully driven a car down a short simple slalom track. It had climbed out of the car, though not without some difficulty, headed over to a door and opened it. But after starting to move through the door Chimp came to a sudden halt; with a lot of inertia (it weighs 200kg) and its centre of gravity a little too far for...