What looks at first glance like a complicated web to exhibition invigilator Ryoka Tamura, pictured, is in fact a giant four-dimensional mathematical ball.

The installation is designed by Edinburgh University student Julia Collins for a new exhibition at Summerhall, for Innovative Learning Week. It contains five shapes constructed from regular polygons known as a "cantitruncated 600-cell". Each of them is made of four equilateral triangles, joined together so there are 20 meeting at each corner. The event runs until February 21.

Picture: Gordon Terris.