In order to move the CA has to change its structure, which it accomplishes by interacting with another agent. In chapter 5 the CA interacted with a barrier. Although it was displaced it soon died. In the present experiment at t = 40 the CA plants a zygote which grows until interacting with its parent. When the parent dies its progeny matures into a CA at a new location. It may then plant another zygote and its progeny moves to a different location.
From now on whenever the CA reaches t=40 (of its personal time) it plants a new zygote, and so on. Movement direction is determined by the side at which the zygote is planted.
Please note:
1. Observer time is set to zero when the experiment starts. Whenever a zygote is planted its individual time is set to zero. Every process in the system manages its own time.
More on biological time
2. The CA is symmetric and isolated. In order to act it first has to interact with another agent. Interaction creates new opportunities.
3. The isolated CA has two functions: It accumulates resources and creates progeny.
4. Displacement lasts only if the CA creates a new solution (attractor). During transient states the CA may move at great distances (Chapter 4). Its final location has to be a solution (attractor).
5. Movement proceeds from solution (attractor) to solution.
