"Escher's art, Smith Chart and Hyperbolic Geometry" https://www.researchgate.net/publication/3427377_Escher's_art_Smith_chart_and_hyperbolic_geometry https://w

"Escher's art, Smith Chart and Hyperbolic Geometry" https://www.researchgate.net/publication/3427377_Escher's_art_Smith_chart_and_hyperbolic_geometry https://www.researchgate.net/publication/3427377_Escher's_ar... "A conceptual relation between Circle Limit IV, an artistic creation by M.C. Escher, and Smith Chart, geographical aid for microwave engineering created by P.H. Smith, was established. The basis of Escher's art and Smith chart can both be traced back to invariance of the cross ration of four complex numbers under Möbius transformation on the domain of complex numbers. The Smith chart can be used as an aid for constructing Escher-like drawings that display periodic mosaic patterns and at the same time convey the perception of infinite progression within a unit circle."