When people think of knowledge, they generally think of two sorts of facts: facts that don’t change, like the height of Mount Everest or the capital of the United States, and facts that fluctuate constantly, like the temperature or the stock market close.
Or, imagine you are considering relocating to another city. Not recognizing the slow change in the economic fortunes of various metropolitan areas, you immediately dismiss certain cities. For example, Pittsburgh, a city in the core of the historic Rust Belt of the United States, was for a long time considered to be something of a city to avoid. But recently, its economic fortunes have changed, swapping steel mills for technology, with its job growth ranked sixth in the entire United States.
These slow-changing facts are what I term “mesofacts.”