Each concept here is mapped to its prerequisites — the ideas you'd need first to understand it — all the way down to four foundations: Space, Time, Energy, Pattern. Click any prerequisite to drill down, or scroll for the chain graph.
A span is a period of time characterized by a beginning and end, which is a measurable extent or length of time between two points in time, allowing us to quantify the duration and sequence of events.
External reference — all senses of the word “span” on Wiktionary. This atlas concept maps to only the slice of meaning relevant to the prerequisite graph.