# Hierarchies, Emergence, Feedback, and NonLinearity

The second lecture further develops the rudiments of spatial systems with respect to their functions, patterns, interactions, size and scale. These characteristics are closely intertwined and we first show how they relate together. We then develop the idea of system and hierarchy showing how modular structure can be arranged as distinct or overlapping subsystems. This hierarchy can be inverted to show both top down and bottom up functioning as well as portraying abstract structure as well as actual space-filling. We invoke here ideas about fractal structure and emergence,and then examine how feedback develops differentiation in size. This sets the context for simple models of growth and change that generate scaling that we illustrate in the next lecture, Lecture 3.

Here is the lecture. Click on the **Full-text PDF** size: 842 Kb or on the adjacent image. The lecture was first given on Wednesday 19th October and posted that same day. It contains more background but takes the argument forward into fractals and patterns and simple models of emergence.Refer to the updated Bibliography page for more material.