http://www.youtube.com/watch?v=W1czBcnX1Ww Video of Boston Dynamics’ Big Dog robot, moving like something made out of flesh and blood over rubble and snow. The slow-motion recovery from a slip on ice (around 1:40) is astonishing. Does it move like that because it’s programmed to mimic a four-legged animal, or because that’s the way you have to move if you have four legs? 22:14