Innovation: Light fantastic

Researchers at the German car maker Daimler Benz have invented a paint that changes colour depending on the position of the viewer. Conventional paint contains pigments that absorb some parts of the light spectrum and reflect others to produce colour. Instead of pigments, the new paint contains liquid crystals. When light is reflected off the crystals, the light waves can reinforce or deflect each other, depending on the angle between the observer and the paint surface, changing the perceived colour.