April 25, 2007
Light pollution

As you know, I grew up in New York City. I experienced a number of culture shocks in coming down to Texas as a college student, but one of the more vivid ones was during my sophomore year, when I was keeping score for the baseball team. We'd all travelled to Kerrville, about sixty miles west of San Antonio, for an afternoon doubleheader against Schreiner College (now Schreiner University), and by the time it was all over it was nighttime. I remember being amazed at how utterly, completely dark it was in that little Hill Country town once the sun went down - it seemed like I could reach out and touch the darkness, it was so enveloping - and consequently how jam-packed with stars the sky was. For someone used to urban night skies, it was quite the revelation. I know that couldn't have been the first time I'd seen such a thing, but for whatever the reason it felt like the first time, and some 20 years later I can still recall it clearly.

I tell you that as an intro to this article, which as you can tell has struck a chord in me:


As the show begins, visitors to the Morehead Planetarium see a night sky free of polluting light. Projected onto the dome is a truly dark sky pricked by countless sparkling points. A narrow smudge -- our galaxy, the Milky Way -- is as clear as day.

Then the light grows to a brightness familiar outside the building. The number of stars visible in the virtual sky drops dramatically, to just a handful of tiny bright spots.

"I know, it's terrible," Morehead educator Amy Sayles says sympathetically to a multigenerational crowd of dozens who gathered at the planetarium for Our Vanishing Night, a program that led up to the Earth Day celebrations.

This year, a growing coalition urged the rest of us to turn down the lights. A group of amateur and professional astronomers has made this plea for decades. Now the astronomers are joined by a new ally -- environmentalists. They think cutting light pollution will cut wasted energy and greenhouse gases from power plants.

It's a match made for the heavens, which are fading to human eyes all over the world.

The International Dark Sky Association estimates that 99 percent of the people in the U.S. and Europe live in light-polluted areas, unable to see traces of the Milky Way or many stars when they walk out of their homes and gaze skyward.

[...]

In 2001, Raleigh, N.C., passed a lighting ordinance that limits illumination spillovers across property lines and requires shielding parking lot fixtures so their light travels only down. In May, all residential fixtures are expected to comply, even those installed before the rules passed.

Orange County has an ordinance too, passed in 2003. Government leaders and planners there are considering requiring fixtures installed before then to lose their exemptions -- over time. The aim is not only to limit the growth of light pollution, but also to reduce it, said Craig Benedict, planning and inspections director.

Although Benedict doesn't expect unanimous support in his growing county, he sees more interest, particularly among environmentalists.

"Energy issues are really bringing this to a head," he said. "The need for more electricity creates the need for more energy production and that means more nuclear plants or coal plants. That's the linchpin that pulls groups together."


I'm not always the best at remembering to turn out lights when I leave a room, so I'm going to try to take this as an inspiration to do better. I figure it's the least I can do to help.

Posted by Charles Kuffner on April 25, 2007 to Technology, science, and math
Comments

I've turned off all my outside lighting at home except when we are entertaining on the deck in the evening. I've found that if I let my eyes adjust to the darkness a few seconds I can see plenty well enough to get from the car to the house or to the garbage can in the alley.

A lot of people claim that lighting deters crime but the statistics in our neighborhood show that most of the crime occurs in the afternoon while we are away at work.

Posted by: bill on April 25, 2007 8:48 AM

Thanks for posting about this issue, which, as a former astronomer and lifelong star-gazer, has always been near and dear to my heart.

This should be a win-win for everyone. No one needs light shone up into the sky or glaring into their eyes while driving down a highway at night. Both are inefficient and the latter can be downright dangerous. And we all lose the spectacle of the stars and Milky Way at night.

We should use shielded light fixtures and encourage everyone else to, as well -- especially commercial developments, which can be the worst offenders (e.g., car dealerships, at least in my area).

As the examples of Raleigh and Orange County mentioned in the article you quote show, we can also encourage our local elected officials to jump on the bandwagon.

Posted by: P.M.Bryant on April 25, 2007 11:44 PM