Energy Moves in a Pendulum Swing

Energy moves in a pendulum swing, between opposites:

All motion is the result of expansion and contraction, to and fro, in rhythmic alternation.

When the swing arrives at its extreme position, it reverses direction and heads the opposite way. Day turns into night, winter into summer, the in-breath into the out-breath.

The pendulum doesn't swing back to its exact departure point, but slightly off, as spirals do.