No matter the diversity of animals, cities, and companies, most of the characteristics within these groups scale quantitatively with their size. In a sense, a dog is 90% a scaled up version of a mouse.
The commonalities of complex systems give hope to finding a way to understand why they behave in particular ways.
All processes require energy. The amount of energy that these processes require to continue is their metabolic rate. Although we primarily use this notion for living organism, we can expand it to include cities and companies.
When energy gets used, it also produces a certain amount of entropy – energy that doesn’t do any useful work. This excess energy is the cause of damage and degradation of the systems that produce it.
Most of the relationships related to scale do not relate in a linear fashion. Just because something is twice the size of something else doesn’t mean it will need twice the energy.
Scaling relationships come in two varieties:
- Sublinear relationships decrease the need per capita as size increases.
- Superlinear relationships increase the need per capita as size increases.
A complex system is categorized by simple components who’s actions add up to more than the linear sum of their output. Often times, these systems take on a life of their own outside of their individual components. We are great examples of a complex system.
Simplicity enables complexity when combine with self organization. The fractal nature of self organizing systems explains why properties rarely scale linearly.
In biology the number 4 comes up again and again when related to scale. As an organism’s size increases, it’s energy needs increase by 3/4. While the heart rate decreases by 1/4 of the size.
No system can sustain unbounded growth. This paints a grim future for our economies and population that has grown without pause. The only way we kept it growing for this long is through technological innovation, but to sustain further growth the innovation needs to happen even more rapidly. Once we hit the limit of our system, we will either need a reset to start the growth again, or the entire system will collapse in catastrophe.