Scale

organisms have evolved to have an enormous range of sizes and an extraordinary diversity of morphologies and interactions, which often reflect increasing complexity, yet fundamental building blocks like cells, mitochondria, capillaries, and even leaves do not appreciably change with body size

Cities are remarkably resilient and the vast majority persist. Just think of the awful experiment that was done seventy years ago when atom bombs were dropped on two cities, yet just thirty years later they were thriving.

A fractal dimension is just one single metric out of many that characterize such systems.

The challenge at every level of observation is to abstract the important variables that determine the dominant behavior of the system.

Highly complex, self-sustaining structures, whether cells, organisms, ecosystems, cities, or corporations, require the close integration of enormous numbers of their constituent units that need efficient servicing at all scales. This has been accomplished in living systems by evolving fractal-like, hierarchical branching network systems presumed op

providing the very reason for our existence as the agents through which the universe would know itself.

Scaling up from the small to the large is often accompanied by an evolution from simplicity to complexity while maintaining basic elements or building blocks of the system unchanged or conserved.

This invariance of terminal units can be understood in the context of the parsimonious nature of natural selection. Capillaries, mitochondria, cells, et cetera, act as “ready-made” basic building blocks of the corresponding networks for new species, which are rescaled accordingly.

Addressing such seemingly innocuous questions concerning how systems respond to a change in their size has had remarkably profound consequences across the entire spectrum of science, engineering, and technology and has affected almost every aspect of our lives.