Roger Penrose: 2 puzzles worth knowing

2 puzzles from Roger Penrose, each explained in a minute and credited to the original work. Free on Savvy.

Two shapes can tile a floor forever without the pattern ever repeating
Most tiling patterns — bathroom floors, brick walls — eventually repeat in a grid. In the 1970s, physicist Roger Penrose found a set of just two tile shapes, nicknamed 'kites' and …
— Roger Penrose, Pentaplexity: A Class of Non-Periodic Tilings of the Plane
A triangle that looks perfectly solid and cannot possibly exist
Look at a drawing of a triangle made from three beams that each look straight and connect at right angles — yet the whole shape loops back on itself in a way no real solid object c…
— Lionel Penrose, Roger Penrose, Penrose triangle

Five ideas worth knowing, every week