p Sampath Jagannathan In p, a bunch of particles interact with each other according to this simple rule: every particle must move towards, away or watch another particle. When the program starts, each particle chooses a random color, position and the particle it will move towards, away or watch. As the program runs, some particles join together to form a train and journey together thereafter. Some other particles orbit each other. Yet others collapse into each other. All these behaviours are not obvious at the start but emerge due to the repeated application of the simple rule above. It thus seems that even in a randomly initialised system, if it operates under a or a few simple rules, order has a chance to rise from chaos.