To help students understand orders of magnitude, and also perhaps to brighten up physics teaching for years 10 to 13, the UK Institute of Physics' Post-16 Physics Initiative has devised a competition for students to design a poster illustrating the key orders of magnitude of the units used in science. It is hoped that some of the winning designs will eventually be used to produce a set of posters for laboratory walls.

Students are being asked to design an A3 poster bearing a logarithmic scale running from the very biggest to the very smallest size for a quantity of their choice. The quantity must be one of the following: mass, time, distance, speed, volume, density, force, temperature, energy, power, resistivity/conductivity, frequency/wavelength.

The scale should also be illustrated with pictures of named items which fit different points on the scale.

Entries will be judged in two age groups, 14-16 and 17-19, with book tokens being awarded to the winners as well as Institute of Physics Publishing books for their schools or colleges. The winning posters should be on display at the `Physics in perspective' course planned at the Royal Institution in February 1999. More information on the competition is available from Mary Wood in the Education Department at The Institute of Physics, 76 Portland Place, London W1N 3DH (e-mail: education@iop.org).