The CA are controlled by the following buttons:
Move down: CA-1 moves down
Shorter: Makes CA shorter.
Longer: Makes CA longer.
Kill CA-1:
Interact: CA-1 affects CA-2 and is not affected by the latter.
New CA-2:  
CA-2 is planted,

The experiment starts with two isolated CA. Let them grow up and click on ‘Move down’. CA-1 turns down and slides above CA-2 without interacting with it. Let CA-1 reach the upper line and when it turns down click on  ‘Interact’. When the two CA touch, their border cells will interact once.  Let them part. Now wait until CA-1 covers CA-2 and then click on ‘Interact’. Interaction occurs only once. You may intensify interaction with repeated clicks.

Interaction perturbs CA-2 and it enters a transient which has two outcomes: CA-2 creates a new solution, or     it dies.  When this occurs Click on ‘New CA-2’.

Generally CA-2 will create an isolated solution at a different site. It may also create two or three isolated CA. Sometimes it creates the  ‘Heart’  solution with a period of  29 .

System solution

Unless perturbed by CA-1, CA-2 will not change its location. Only interaction may change it. Once it settles down it will regain and maintain its isolation. Actually the applet illustrates a two CA system, which  starts with two non interacting CA. The observer perturbs it and enables interaction  whereupon the system evolves until it creates a solution which consists of the solutions of its individual CA.

CA breeding

Although the system is relatively simple its unfolding is unpredictable. However we are less concerned with its evolution.  What we are after is whether the system creates a solution. It’s like breeding animals. Here we breed CA systems  with interesting solutions, hoping to discover one which optimizes itself.