Title: The Physics and Control of Balancing on a Point Abstract: In the field of robotics, the task of actively balancing on a narrow support, such as a point or line, is usually seen as a control problem; and it has been solved many times using various ideas from control theory. This talk takes a fresh look at the problem from a physical point of view, which yields both a simple model of the physical process of balancing and a simple control system to accomplish it. For the special case of balancing in a plane, the robot's behaviour is characterized by just two numbers, and the controller's gains are trivial functions of these numbers. The resulting control system is able to balance the robot in such a way that a single joint can perform two tasks at once: balance the robot and simultaneously follow a commanded motion trajectory. Several examples of balancing behaviours will be shown and explained, including the technique of leaning in anticipation of a future motion command.