Constructal Patterns Formation in Nature, Pedestrian Motion and Epidemics Propagation

Abstract

The emergence of shape and structure in animate and inanimate systems is among the most fascinating phenomena in our planet.The formation of dissimilar patterns inside similar systems under different environmental conditions is especially intriguing. Examples of these phenomena can be found in almost every field, ranging from physics to the behavior of social groups.Pedestrian crowd motion also exhibits a variety of conjunction patterns, from more or less ‘chaotic’ appearance to spontaneous organization in lanes of uniform walking direction looking like river-like streams. What determines the condition for the existence of so dissimilar patterns? There has been a renewed impetus for the study of geotemporal spread of epidemics, following concerns over the increasing potential outbreak of infectious diseases. Throughout history several pandemics have occurred in many areas of our planet, infecting and wiping out a large number of people. Historic records of the progress of this outbreak suggest a wave-like propagation of the disease. What are the conditions for the existence of such a traveling wave? Would pandemics nowadays follow a similar propagation pattern as those occurring in the previous centuries? In this chapter, we will examine the formation of dissimilar patterns inside these systems from the view point of the constructal theory of organization.