## geometry

**Nicholas Mee**discovers, that would be far too simple. In fact, the length of a day varies throughout the year. If you plot the position of the Sun in the sky at the same time every day, you get a strange figure of eight which has provided one artist with a source for inspiration.

**Josefina Alvarez**and

**Cesar L. Garcia**investigate.

**Gábor Domokos**, one of their discoverers, reckons that in some sense they barely exists at all. So what are Gömböcs and what makes them special?

**Phil Dench**tells

*Plus*how he uses mathematics to help bring these models to life.

Cambridge celebrates 25 years since the first very early Universe workshop

*any*tilings based on fiveness?

**Craig Kaplan**takes us through the five-fold tiling problem and uncovers some interesting designs in the process.