# Bernhard Rietzl

Freelance artist
Schwabmuenchen, Germany

I am interested in the combination of art and mathematics especially number theory. Prime numbers can be seen as the elements of the whole numbers, compound numbers literally are the products of these basic elements. It is like in chemistry where the chemical elements are the basis for all compound molecules.

Prime divisor cube towers on Ulam spiral
27cm (h) x 54cm (w) x 54cm (d)
Colored wood cubes
2012

This kinetic art object displays the numbers from 1 till 144. The numbers are arranged in the form of a so called Ulam spiral with 1 in the center and consecutive numbers spiraling around the center on a rectangular grid. The numbers are represented by stacks of cubes, each cube standing for a prime divisor of that number. So prime numbers are represented by a single cube, compound numbers by stacks of two or more cubes. The prime divisors 2,3,5,7,11 and 13 are color coded (2=green,3=red;5=yellow;7=blue;11=orange;13=purple), higher prime divisors are coded by a black and white binary pattern on the cube.

People are invited to go round the sculpture to explore the mathematical aspects and also to experience the changing impression of colors depending on the point of view.

The artwork can be extended by placing further boards round the starting one.