One analogy that comes to mind is the structural system of a tree, and the structural systems we design for buildings. The foundation must go deep into the ground. This resists the vertical load of the structure to prevent sinking, as well as the horizontal wind and seismic loads to resist uplift or overturning. Tree roots perform a similar function, gradually distributing the vertical load of the tree throughout the soil to avoid sinking, and anchoring both down and sideways to resist moments at the base. This analogy can extend to the top of the tree as well. The smallest, lightest parts of the branches are at the very edges, with the leaves at the tip. We follow this approach when designing skyscrapers. The smallest part of the building is at the very top, to make sure that it can be supported by what is below it. In a tree branch, branches or leaves are always supported by a thicker, more substantial branch, coming together in the solid trunk.
Another analogy that I have been thinking about recently is an animal’s digestive system and a building’s waste system. An animal eats food in one form, and then their digestive system breaks down that food using different methods, including mechanical and chemical methods. Some of that food is processed and kept long-term in the body, and the rest exits the body in a different form. Waste in a building goes through a similar life cycle. Take the package of toothpaste I received recently as an example. The package arrived in a cardboard box taped closed, with smaller tubes of toothpaste inside, each in their own smaller packaging. I used mechanical means to rip the tape, remove the valuable toothpaste packages, and then break down the cardboard box and bring it to recycling. The box traveled down the recycling chute, which is analogous to intestines. I then used mechanical methods to remove the toothpaste tubes from their smaller individual packages. These packages were put in compost, mimicking the chemical processes an animal uses to break down food.
