Stick like hell When the Wizard of Menlo Park called invention 10 percent inspiration and 90 percent perspiration, he was speaking not only about the creative act of inventing but also about the whole inventive process needed to bring more than intellectual success. Edison warned against discouragement during the perspiration phase in the following way, reminding us that we get things to work by the successive removal of bugs: Genius? Nothing! Sticking to it is the genius! Any other bright-minded fellow can accomplish just as much of he will stick like hell and remember nothing that's any good works by itself. You've got to make the damn thing work!...I failed my way to success. Thomas Edison, The Evolution of Useful Things inventionsuccess
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