To pick up my pen An Article by Nick Cave www.theredhandfiles.com The most important undertaking of my day is to simply sit down at my desk and pick up my pen. Without this elementary act I could not call myself a songwriter, because songs come to me in intimations too slight to be perceived, unless I am primed and ready to receive them. They come not with a fanfare, but in whispers, and they come only when I am at work. Touch the keys creativityroutine
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