When trying to understand the world, we apply models to it, in order to quantify what we see. Different models are used to look at different things. A crucial point is understanding what models to apply at what resolution. A model which is well suited to say something about the population of a country may break down when increasing the resolution to looking at a city, or it may still hold true, but break down when trying to apply it to residents in a street, the inhabitants of a building, or individual men and women.