After a massive power outage in Los Angeles, many residents called 911 and reported seeing strange clouds overhead – the Milky Way
When a massive power outage hit the southern part of California in the 1990s, Los Angeles citizens allegedly called 911 to voice alarm about unusual clouds flying in the sky; they were seeing the Milky Way for the first time.) The issue is not lights in itself, but the multi billions of dollars worth of electricity wasted each year by dumping light into the sky rather than limiting it to the surface where it is needed.
San Francisco lights 1944
Light pollution has pushed skilled astronomers to site their observatories on distant islands and mountaintops, while taking beginner astronomers—and their children—of weak stars and galaxies lost in the glare.
Luckily, there are alternatives that save money and protect the dark night sky. The most important step is to shield outside lighting so it is cast straight down. Other actions include placing motion sensors on the security lights that, in so many situations, overflow personal yards all night; this actually improves protection while saving on energy bills. It also helps to restrict the particular wavelengths in which the light is produced.
Much of modern day astronomy depends on spectroscopy, where we should be able to find light at the particular wavelengths equivalent to numerous elements. Low-pressure sodium lamps emit light at only a few distinct wavelengths, making the rest of the range free of polluting light. Shielded low-pressure sodium lamps are used, for example, in the city of Tucson, Arizona; as a result you can look up from a town center Tucson intersection at eleven p.m. and see more than a 1000 stars. These lights are also incredibly energy-efficient, making them the most cost-effective form of street lighting.
If we all work with each other, upcoming generations can recover some of the pleasures of viewing in the dark.