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.
Friction is created between two surfaces through the application of pressure as one surface is moved back and forth against the other, building on the concepts of motion and force.
External reference — all senses of the word “Rub” on Wiktionary. This atlas concept maps to only the slice of meaning relevant to the prerequisite graph.
Trace. Question. Emerge.