You might ask yourself, what's the usefulness of a robot that's unstable? Now we'll explain that in a second. Let me first explain how Rezero actually keeps his balance. Rezero keeps his balance by constantly measuring his pitch angle with a sensor. He then counteracts and avoids toppling over by turning the motors appropriately. This happens 160 times per second, and if anything fails in this process, Rezero would immediately fall to the ground. Now to move and to balance, Rezero needs to turn the ball. The ball is driven by three special wheels that allow Rezero to move into any direction and also move around his own axis at the same time. Due to his instability, Rezero is always in motion. Now here's the trick. It's indeed exactly this instability that allows a robot to move very [dynamically]. Let's play a little. You may have wondered what happens if I give the robot a little push. In this mode, he's trying to maintain his position.