## aperiodic tiling

*moiré nanolithography* and the researchers hope that it will find useful applications in the production of solar panels and many other optical devices.

Mathematicians offer new proof of quasicrystals' strange electronic properties.

*Plus*talks to

**Sir Roger Penrose**about all this and more.

**Alison Boyle**investigates aperiodic tilings, which have had unexpected applications in describing new crystal structures.