A double pendulum consists of two pendulums attached end to end. The first pendulum swings from a fixed point, while the second pendulum hangs from the end of the first. This setup creates complex motion, as the movement of one pendulum affects the other, leading to unpredictable paths. The double pendulum is a classic example of chaotic motion in physics. Small changes in the initial conditions can result in vastly different outcomes, making it difficult to predict its behavior over time. This phenomenon is often studied in the context of chaos theory and nonlinear dynamics.