Inverted pendulum

An inverted pendulum is something that looks like a stick or pole balanced on top of something else, like a cart or a box. The stick is balancing on its own, like a tightrope walker! It's tricky because it's easy for it to fall over — getting it to stay in place is the challenge. To do this, scientists use something called a controller, which is a machine that helps the pendulum stay in place. The controller looks at where the pendulum is and then makes small adjustments to keep it steady. That’s why it’s called “inverted” — it’s upside down and trying to stay that way!