There are two ways of understanding the physical world. The first is a view from “nowhere,” a God’s eye view of the world. Physics, for the most part, has taken this line of understanding. However, it is also possible to describe the physical world from a particular perspective, that of an ant or an elephant. Each of these perspectives is embedded in a “somewhere.” I am going to give somewheres a fancier name; let us call every somewhere a niche. Each niche, which only occupies a particular range of parameters (for example, life can only exist within a narrow band of temperatures) has several patterns that are it’s signatures. Therefore, let me define a regularity as:
A regularity is a pattern that informs us about other elements in a niche.
For example, clouds can only exist because of the particular combination of temperatures and gases on Earth; that said, other planets can also have the same parameters, which is what makes astrobiology interesting. When I see a cloud, it’s fluffiness is a regularity that informs me that the cloud is soft. I would be really surprised if a cloud turns out to be hard as a rock.
At the same time, a cotton ball is also fluffy and it’s fluffiness also tells me that it is soft. Clouds are made of vapor while cotton balls are made of cotton. In both cases, fluffiness is informative about density. There is something generalizable about regularities, so that the regularity is not tied to the precise mechanisms that underlie the phenomena. Our definition should somehow capture the inherent generalizability of regularities. More on that later.