The Internet Is Rotting An Essay by Jonathan Zittrain www.theatlantic.com Too much has been lost already. The glue that holds humanity’s knowledge together is coming undone. Links work seamlessly until they don’t. And as tangible counterparts to online work fade, these gaps represent actual holes in humanity’s knowledge— they represent a comprehensive breakdown in the chain of custody for facts. The web in decay is the web by design wwwhypermediadecayknowledge
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