There is a very moving video that's "gone viral" on U-tube of a young lady from the Ukraine doing sand drawings:
Kseniy Simonova's Amazing Sand Drawings.
I will admit that I was moved by this display. Sand drawing is part of some very different cultures including the aboriginal culture in Australia, the Navajo in the Southwest America and Buddhist monks (Mandala sand painting). I saw the latter in action once in Albuquerque (not too far from the Navajo reservation). There are a large number of other cultures that practice this art.
When one realizes how sophisticated some of these works of art are, it makes you feel pretty humble.
The more esoteric, repetitive patterns produced are frequently reminiscent of cellular automata and that probably deserves another post.