### Abstract

M.C. Escher, the graphic artist famous for mathematical patterns and optical illusions, left a blank spot in the middle of his 1956 lithograph, "Print Gallery". Escher signed his name there, instead of completing the center of this picture of curved and whirling buildings. In 2002, a team of mathematicians, computer programmers, and artists used techniques from advanced mathematics to figure out how Escher might have completed the picture. The team was led by Hendrik Lenstra, who will reveal the secrets behind the mysterious blank space during this talk. The presentation and explanation of the mystery will include a number of beautiful images and animations.

Hendrik Lenstra is Professor of Mathematics at the Universiteit Leiden, the Netherlands. Dr Lenstra is a world-renowned mathematician who is known for the clarity and wit of his lectures. His presentation will be aimed at a general audience and should appeal to anyone interested in art, mathematics, or the intersection of the two subjects.

### Related Links

- http://escherdroste.math.leidenuniv.nl/ - For pictures of the completed work, visit the Print Gallery homepage