Sort of underway by then He was sort of underway by then...he had this whole ritual for showing the work to people – you had to sit in a chair that was positioned what he felt was exactly the right distance from the painting. There was a certain mystique about it that worked for him. Craig Kauffman, Robert Irwin: A Conditional Art ritualmystery
Mystery exists in the mind Mystery exists in the mind, not in reality. If I am ignorant about a phenomenon, that is a fact about my state of mind, not a fact about the phenomenon itself. All the more so if it seems like no possible answer can exist: Confusion exists in the map, not in the territory. Unanswerable questions do not mark places where magic enters the universe. They mark places where your mind runs skew to reality. Eliezer Yudkowsky, Rationality: From AI to Zombies The Tao of rationality mysteryconfusion
The world of shadows The 'mysterious Orient' of which Westerners speak probably refers to the uncanny silence of these dark places. And even we as children would feel an inexpressible chill as we peered into the depth of an alcove to which the sunlight never penetrated. This was the genius of our ancestors, that by cutting off the light from this empty space they imparted to the world of shadows that formed there a quality of mystery and depth superior to that of any wall painting or ornament. Jun'ichirō Tanizaki & Thomas J. Harper, In Praise of Shadows darknessmystery
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