I invent models to explore the physical properties of magic squares. More recently I defined the 46 sphinx dominoes.
The illustration below is a 11 x 11 magic square depicted as a water retaining surface. The letter "H" is shown with side specific drainage to the left and to the top. Of the 26 letters, the letter H is the most difficult to make. Harry White and I wrote the American declaration of independence on the surface of a large magic square in 2014.
This illustration shows a efficient way to figure the water retention for one of these squares.
The fundamental sphinx tile based macro-tiles that tile larger order sphinx are identified.
Various polyiamonds are used to tile the bird.
Five different pentiamond tilings of the bird.