The Blind Juggler is a robot that juggles or bounces balls in a controlled manner without any sensory input. It is basically just a linear actuator with a paddle on the end to smack the ball back into the air as it returns to the ground. The crazy thing is, it is doing this based purely on pre programmed math. There are no sensors telling it to make any adjustments. While we could envision this functioning, we would never have expected it to be as stable as it is. You can see in the video above that they can actually move the entire robot around while maintaining the bounce. Also check out the pendulum version, instead of just actuating vertically, it is mounted as a pendulum allowing the ball to travel back and forth in an arc.