One of the things Bob Glass liked about this type of modeling was how easy it was to explain. Models were abstractions, but what this model was abstracting from was familiar: a single entity, which you could describe as a person, a piece of information, or any number of other things. As the green dots turned red, you could be watching gossip travel, a traffic jam, a riot start, or a species go extinct. “When you start talking about it this way, everyone can understand it immediately,” he said.
