Cellular automata and most of the other systems in this book readily admit various kinds of whimsical descriptions. The rule 30 cellular automaton, for example, can be described as follows. Imagine a stadium full of people, with each person having two cards: one black and one white. Make the person in the middle of the top row of seats hold up a black card, and make everyone else in that row hold up a white card. Now each successive person in each successive row determines the color of the card they hold up by looking at the person directly above them, and above them immediately to their left and right, and then applying the simple rule on page 27. A photograph of the stadium will then show the pattern produced by rule 30. Descriptions like this may make abstract systems seem more connected to at least artificial everyday situations, but if the goal is to focus on fundamental ideas, as in this book, then such whimsy is, in my experience, normally just a major distraction.