Shedding Light on the Value of Darkness
Dan Green is out to change the way we see the night.Green is an astronomer -- and an optimist. Just twenty years ago, he says, we could not have imagined freedom from second-hand cigarette smoke. Now, we need to raise consciousness about the fact that there is no need to live with light pollution.Traditional outdoor lighting -- the kind that lights highways, streets, businesses, billboards, and houses -- sends a fair proportion of the light upward.This light is of no use to us, but it does produce the skyglow that impedes the work of astronomers and robs millions of people of the beauty of the nighttime sky.It also robs them in another way. According to Green, $2 billion, much of it in taxpayers' money, disappears upward toward space each year.Green is co-founder of the New England Light Pollution Advisory Group (NELPAG), whose members are amateur and professional astronomers and lighting engineers. Their purpose is to educate the public about how good outdoor lighting can drastically reduce light pollution.One major step would be a switch to "full-cutoff lights." These are recessed so the light shines downward instead of outward. Many states have passed or are considering laws requiring such lights for all state funded projects.Green is passionate about the right to be awed by the stars. He owes the inspiration for his life's work to stepping outside at night as a child beneath a star-spangled North Carolina sky. If every city light were shielded, says Green, you could see the Milky Way from most major cities.Some communities have passed outdoor lighting ordinances requiring outdoor lighting be energy-efficient and unobtrusive. The ultimate example so far is Tucson, Arizona, a city of 700,000, which has a spectacular view of the nighttime sky. By contrast, Chicago's sky, lit by "hang drop bulbs," has an orange glow that looks, says Green, almost like Hell.The supposed benefits of outdoor lighting aren't borne out in studies, says Green. Consider the relationship to crime and safety, for example. Most robberies occur not under cover of darkness but during the day when people are away at work.Lighting may even encourage crime and vandalism. Some school districts (notably San Diego) now leave school grounds completely dark at night, which means that flashlights and even cigarette butts are now immediately visible -- and that teenagers no longer hang out there.Several small Massachusetts towns have turned off half or more of their streetlights with no increase in crime or accidents. In fact, the glare from traditional street lights can cause accidents, particularly when it is raining.Good outdoor lighting also reduces "light trespass," the annoying light in your bedroom window from a nearby streetlight, porch or business. Homeowners and businesses can also save money by using full-cutoff fixtures that light just the area needed with minimum wattage.What are the obstacles to change? The utility companies, says Green, make big money off outdoor lighting and have little incentive to switch to more aesthetic and efficient lighting. And there is little public awareness -- people simply don't know the difference between good lights and bad lights because there are so many bad lights out there."Good outdoor lighting is a win-win-win situation," says Green. "It reduces light trespass, skyglow, and energy costs. It's a no-brainer."Last spring, Green took his son out to see the much heralded Comet Hyakutake swing into town -- and saw only a faint, disappointing smudge. His neighbors hadn't even been able to find that. Then Green packed up his family and drove two hours north from their suburban Boston home to the mountains. There, the comet's tail swept a third of the way across the sky.The night sky is our oldest companion. The earliest humans must have felt the same awe and fascination staring at it that we still feel today -- or would, if we could see it in its full splendor.The right combination of education and legislation can restore that splendor, and just might make Dan Green's dream come true: to step outside his home and see the Milky Way.