In a years-long quest, students at Waseda University in Tokyo, Japan are constantly tweaking the programming of WABIAN R-II in the hope of making the heavy, two-meter-tall machine walk as easily as a human being. WABIAN sways from side to side as it walks, but its builders are not discouraged by its imperfections: walking in a straight line, which humans can do without thinking, in fact requires coordinated movements of such fantastic complexity that researchers are pleased if their creations can walk at all. Indeed, researchers built the robot partly to help themselves understand the physics of locomotion. It took decades of work to bring WABIAN to its present state: its first ancestor was built in 1972. From the book Robo sapiens: Evolution of a New Species, page 14.