We infantilize ourselves Here in the US, we expect government and law to be our conscience. Our superego, you could say. It has something to do with liberal individualism, and something to do with capitalism, but I don't understand much of the theoretical aspect—what I see is what I live in. Americans are in a way crazy. We infantilize ourselves. We don't think of ourselves as citizens—parts of something larger to which we have profound responsibilities. We think of ourselves as citizens when it comes to our rights and privileges, but not our responsibilities. We abdicate our civic responsibilities to the government and expect the government, in effect, to legislate morality. David Foster Wallace, The Pale King societygovernmentpoliticsmoralitycivics
Wang tiles Wang tiles (Hao Wang, 1961) are a class of formal systems. They are modelled visually by square tiles with a color on each side. A set of such tiles is selected, and copies of the tiles are arranged side by side with matching colors, without rotating or reflecting them. The basic question about a set of Wang tiles is whether it can tile the plane or not, i.e., whether an entire infinite plane can be filled this way. The next question is whether this can be done in a periodic pattern. In 1966, Wang's student Robert Berger solved the problem in the negative. He proved that no algorithm for the problem can exist, by showing how to translate any Turing machine into a set of Wang tiles that tiles the plane if and only if the Turing machine does not halt. The undecidability of the halting problem then implies the undecidability of Wang's tiling problem. Wikipedia en.wikipedia.org Truchet TilesThe Tiling Patterns of Sebastien Truchet and the Topology of Structural Hierarchy mathalgorithms