To create noblemen and kings While civilization has been improving our houses, it has not equally improved the men who are to inhabit them. It has created palaces, but it was not so easy to create noblemen and kings. Henry David Thoreau, Walden societycivilization
Can maintenance save civilisation? An Article by Tim Harford timharford.com Maintenance is a low-status affair: you can confess to being unable to change a tyre in a way that you would never confess to being unable to name a play by Shakespeare. …We understand the expertise of janitors, plumbers and mechanics, and we suffer mightily in their absence, yet somehow we take them for granted. We take for granted, too, the most basic maintenance of all — preparing food, washing clothes, changing dirty nappies. Nobody would boast at a dinner party or on a first date about doing any of this, yet it is essential. …This is about more than breaking bridges and breaking bike chains. There is a missed opportunity here to find something rather wonderful in maintenance. repaircivilization
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