When more than one pendulum is in motion, we can combine their x and y coordinates to create complex movement patterns. For example, consider two pendulums swinging with the same period and amplitude: one swings along the x-axis, and the other swings along the y-axis. If the second pendulum begins its motion when the first is at its lowest point, their combined movement forms a circle.

When a system contains three or more pendulums, the combination of their coordinates remains logically consistent. However, it becomes increasingly difficult for our minds to intuitively comprehend the resulting motion. Fortunately, there's a more approachable way to understand it — by visualizing a physical chain of pendulums.

Consider a simple chain of three pendulums:

1. The first pendulum is attached to a fixed ceiling.
2. The second pendulum is attached to the end of the first.
3. The third pendulum is attached to the end of the second.

In this setup, each pendulum uses the previous one as its dynamic root. As a result, the third pendulum’s movement becomes a combination of all three pendulums in the chain.

This concept is known as The Pendulum Chain.