Shapes in chaos is a captivating thought. In my belief they are just what everything in the Universe is. Shapes that forms from random amount of random events. Because most of the actions seems to have a reaction, the very important thing is position. Impacts between distant objects is small and impact with nextdoor object is allways the same.
Well how about if objects have none effect between. They still have a start, an ending and a behaviour. That forms a shape too.
In this demo objects have routine like: Born in size 1-4px, Get a random point from shape (in this case circle). Move away in random direction with accelerating speed, get smaller and after reaching the edge of the stage start over.