String modelThis applet displays a cellular automaton model of string.
The model is exactly reversible - and can be run backwards by ticking the checkbox supplied.
It uses an isometric neighbourhood - known as the Square-16 partitioning neighbourhood in order to produce a reversible system. This is a larger version of the Square-4 partitioning neighbourhood.
While it is a development of the "membrane" model, it uses a much larger neighbourhood and uses a much smaller number of states per cell - and makes no attempt to model links explicitly.
Partition rulesThe automaton can be thought of as consisting of three layers:
Cellular evolution progresses according to a large number of rules:
Currently not all rules are typically used - since there is no way of moving to states containing strings that move through reflex (i.e. 315 degree) angles.
While - in principle - the strings are mobile, any string of a significant size has a powerful tendency to stay in one place.