Light comes in several distinct flavours, which can be split up based on the angle that the waves are travelling relative to your eye. it's this trick that's used to reduce glare in polarised lenses, which act like letterboxes for light - only light travelling at the correct angle can make it through the lens. The technique is everywhere - insects and fish can do it naturally, but you're probably reading this through a polarising filter now - it's the basis for almost all display screens, from TVs to computers to smartphones.

By crossing two opposed lenses, all light is stopped, but some materials can twist the light as it passes. By studying this twisted light and the patterns it produces, scientists can learn a lot about the way a material has been made and how it performs under load. The same trick is valuable when studying liquid crystals, such as the membranes that surround each cell in your body [pictured in the link below - please give credit to Nick Brooks of Imperial].

BCFN students will be demonstrating the effects of polarisation at Cheltenham Science Festival this year, and at a range of other events to be announced on this page. If you would like to know more about the physics of light or about the BCFN's science roadshow, please get in touch via bcfn-info@bristol.ac.uk.

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