The whole is more than the sum of its parts.
A property that none of the members of a set have, but they manifest together. A simple example of emergence.
The edge of the disk is higher and the center of the disk is lower in terms of gravity. This special shape causes each marble to oscillate in a groove. If friction were truly zero and there was no air resistance, each marble and their collection could continue this beautiful regular motion forever. However, in reality, rolling friction and the force of air resistance gradually reduce the amplitude of each marble's oscillation, and gradually, at a time near the center of the disk, all the marbles come to rest.
This is a simple example of emergence. Emergence exists throughout the universe, from elementary particles to the movement of birds and the collective behavior of humans.
If you look at the appearance of each marble, you only see an almost one-dimensional (although it sinks a little in depth) straight movement, but together they create an amazing circular motion that was difficult to imagine at first.
