Published online by Cambridge University Press: 13 May 2016
Light pollution is a serious problem, not only to astronomy but also to the environment and the economy. The amount of light energy loss from Cairo has been calculated using data obtained at Kottamia Observatory in 1980 and 1995. The amount of energy loss is much greater in 1995. Comparison with a number of other world cities is given. These results show that much money is being wasted. Recommendations to overcome the problem, and the corresponding savings, are given.