National light-pollution lawIn 2002, the first national law prohibiting "light pollution" went into effect. The Czech Republic became the first nation to outlaw excess outdoor light. All outdoor light fixtures in the country must be shielded to ensure light goes only in the direction intended, and not above the horizontal. Czech astronomers had lobbied for the legislation. Light from street and road signs bounces off molecules in the atmosphere, making skies less dark. This light pollution is a particular problem for astronomers since even low levels of man-made light from distant cities can obscure their view of faint objects far away in space. Better designed, non-polluting light fixtures should give everyone better more energy efficiency and reduce glare on roads and in residential areas.[Image: Skyglow 120km north of Adelaide, Australia.] |
