The Trouble with Five (2007)
plus.maths.org
plus.maths.org
(Note: my swipe keyboard got “toroidal” on a mangled swipe and turned “number” into “bumble”. Sometimes I wonder whether this thing is reading my mind or dictating thoughts to me.)
Could this be related to 5 being a prime number? Are there any examples or counter-examples of prime-number sided shapes tiling the plane?
https://en.wikipedia.org/wiki/Template:Regular_hyperbolic_ti...
(You gotta click [show] for some reason)
These are all the possible tilings, organized by the number of sides of each polygon (Y axis) and the number of polygons meeting at each point (X axis).
The table shows that all of the infinitely-many tilings are possible, but most of them (infinitely many) only work on the hyperbolic plane (cells with blue backgrounds).
The cells with red backgrounds are tilings that work on the sphere, like {5, 3} (three pentagons around each point).
And the cells with green backgrounds, the rarest of all, are the tilings that work on that knife-edge between the sphere and the hyperbolic plane: the flat, Euclidean plane.
The green cells are at {6,3} (hexagontal tiling), {4,4} (square tiling) and {3,6} (triangular tiling).
Anyway, just wanted to share this table because it's quite hard to find on Wikipedia and presents the subject in a way that I found enlightening and satisfying.
Run substitutionList.show(1, 1000) in the browser console to show them all on one page.