For an entire month around Christmas a string of bright lights dangling from the eaves of my neighbor's house illuminated my bedroom each night from dusk till dawn. I was already having trouble sleeping at night. Recently moved back from Wyoming where a bright night is a full moon reflecting off snow, the city kept me awake with its constant baritone rumble and source-less light pollution that wiped out stars, turned midnight clouds white, and made after-dark strolls around the block shockingly hazard-free.
I never complained about the light trespass from next door. It seemed unneighborly. I realized later, when the lights came down, that it wouldn't have made much difference anyway. I still went to bed practically able to read the book titles on the shelf across the room.
Like eskimoes with snowflakes, we moderns have named many varieties of light pollution:
â€˘ Light trespassâ€”light illuminating beyond the property boundary on which it is located
â€˘ Over-illumination, the excessive use of light from improper design;
â€˘ Light clutter, excessive and distracting light grouping, such as too many lit signs along roadways;
â€˘ Skyglow, the effect of an illuminated dome at night over populated areas,
Across the country and around the world, astronomers, politicians, scientists, health care workers and everyday people are recognizing the effect of light pollution on our skies and our bodies and making some changes to counteract the results. From Haifa, Israel to Sun Valley, Idaho, light-at-night is a serious topic. Utah contains some of both the cleanest and the most polluted night skies. But so far, at least, the topic has not been taken very seriously here.
Residents of Salt Lake Valley live in extreme light pollution conditions. The valley rates a Class 8 on the Bortle Light Pollution Scale, measured from one to nineâ€”on par with Los Angeles and New York City. Under these conditions, our midnight hours don't seem very night-like. The sky glows whitish-orange, and stars and familiar constellations are difficult or impossible to see.
Used around the world, the Bortle Scale was developed in 2001 by retired county fire chief and avid amateur astronomer, John E. Bortle. "Most of today's stargazers have never observed under a truly dark sky," said Bortle speaking to Sky and Telescope magazine when the publication debuted his light pollution scale. "[People] lack a frame of reference for gauging local conditions...[they] describe observations made at 'very dark' sites, but from the descriptions it's clear that the sky must have been only moderately dark."
In order to preserve a standard for the night sky, Bortle created a chart that allows astronomers to gauge the darkness and clarity of a sky on a set of concrete objective conditions.
Deep within the southern desert, national parks and forests, Utah's Bortle-rated sky map shows some of the darkest night skies in the entire nation. In fact, in 2007, Natural Bridges National Monument, in the southeast corner of the state near Blanding, earned a Bortle class 2 and the title of the world's first International Dark Sky Park from the International Dark-Sky Association.
At a class 2, Natural Bridges' night sky reveals a highly structured Milky Way, visible to the unaided eye. Bortle's description say that in this sky the brightest parts appear similar to veined marble when viewed through binoculars. Clouds appear only as dark holes in the starry background. The San Rafael Swell, Escalante National Monument and Zion National Park join Natural Bridges in this class group. However, the midnight skies around Moab and the Uintas already show a changing story (to see Utah's sky chart yourself go to www.cleardarksky.com).
Yellow marks the sky map around Moab and Heber, the color code for class 4. The suburban transition, yellow also marks more obviously developed areas such as Stansbury Park and Tooele. All are considered places moderately to seriously impacted by light-at-night, characterized by domes of light visible on the horizon from population centers in several directions. Here the Milky Way begins to lose its structure.
Ron Allen, a current resident of Stansbury Park and former minority whip in the Utah State Senate, watched with concern, 10 years ago, as billboards and neon signs began cropping up in the once rural suburb. Also an amateur astronomer, he witnessed with concern the dimming of the night stars around Tooele, and decided in 2003 to propose a piece of legislation to the State Senate urging light pollution prevention. Whereas, light pollution is sky glow, glare and light trespass, the resolution read, whereas light pollution includes the unnecessary expense of $2 billion annually, nationwide...to protect Utah's night sky, as it would all natural resources, for the benefit of its citizens...be it resolved that the Legislature of the state of Utah...urges state agencies to take steps to prevent light pollution.
The same year, Arizona was passing House Bill 49, which included a chapter on light pollution requiring fully or partially shielded fixtures throughout the state. The bill set lighting standards for municipal buildings, the state capital, state universities and colleges, administrative buildings, and outdoor light fixtures owned and operated by the state or cities and towns within the state, based on recommendations by the Illuminating Engineering Society of North America Lighting Handbook. At the same time, Wyoming was passing an outdoor lighting act, "to minimize light illuminating unintended areas and maintain dark skies." New Mexico and Colorado were ahead of the game, each having passed light pollution bills two years earlier in 2001.
Back in Utah, heeding advice from his peers who did not expect an Arizona-style bill to have any chance, Allen downgraded his bill to a mere resolution, but even that was too much for Utah lawmakers to handle. When Allen brought his proposal to committee, he recalls, laughter broke out in the meeting.
"People in the majority party ranked light pollution up there with climate change. I think my colleagues gave me an award that year," he continues with surprisingly good humor, "for being the only person with a resolution to fail in committee."
In the years since leaving the State Senate, Allen says he has noticed some changes. Billboards increasingly have down-facing instead of skyward illumination. New lights along I-15, added during the latest round of construction, use more efficient, downward-facing fixtures. But, he says, it's just a matter of business. "Industrial engineers are more aware of energy and cost savings from efficient lighting," Allen says. "It's not light pollution prevention, it's more bang for the buck."
In 2006, then-mayor Rocky Anderson and the City Council took another stab at light pollution, together with neighborhood representatives and others creating a 30-page street lighting master plan and policy document. I called Jill Remington Love, current city council member who also served in 2006, to see what had happened with the master plan. A copy of the plan still floating around on the internet showed research and planning for lighting levels and designs. It mainly targeted streetlights in residential areasâ€”subdivisions, new and existing developments, neighborhoods and alleywaysâ€”but touched on some major streets (Redwood Road) and commercial districts (Sugar House, Trolley Square). Like the Utah Senate light pollution resolution before it, Remington Love informed me, the city's lighting master plan had failed.
"The issue was too complicated," explained Love. "On one side, you have neighbors who want fewer lights on the street because of concerns about light pollution. On the other, you have people who want more lights for safety." Safety, as always, proved a difficult argument to overstep, though a section in the plan on crime prevention clearly stated, "Poor street lighting is not the main contributing factor in nighttime crime in public spaces."
To make matters even stickier, certain neighborhoods had, at the time, started paying for special decorative lighting on their streets. They balked at spending even more to relight other neighborhoods in the city. So the city council let the initiative slip quietly away.
Since the death of Salt Lake's well-meaning attempt at restricting light pollution, the city has seen small changes, slowly. Burned-out cobra-head streetlights along major thoroughfares such as 7th East have been, one by one, replaced with newer, state-of-the-art, recessed-bulb luminaries. Lantern-style, partially shaded, or cut-off, luminaries now grace the hip districts like 9th and 9th and around downtown. This summer, and into the next year, Salt Lake's city council will revisit the issue of a city lighting master plan. Once again, they hope to enact a plan, and create a way to pay for it, that will retire old, inefficient, unhealthy lighting for good.
Bryce Canyon National Park
Bryce Canyon National Park has some of the darkest skies in America. Check out the Bryce Canyon Astronomy Program every Tuesday, Thursday, and Saturday at the Visitor Center, beginning at 9 p.m. from June until the second Saturday in August (except Saturday, July 28, which is the Geology Festival). All astronomy programs are followed by stargazing with telescopes, weather permitting. The best nights to attend are those around the new moon: Tuesday, June 19, and Tuesday, July 17 or Thursday, July 19. The program continues into late summer with an earlier start time. See www.nps.gov/brca/planyourvisit/astronomyprograms.htm for more details.
We think deeper thoughts in the dark
Itâ€™s notable that two of our most famous astronomers, Neil deGrasse Tyson and Carl Sagan, were both born and raised in New York City. Though the Big Apple is known for a lot of things, something that its residents communally miss out on is a decent view of the stars. City dwellers spending time out in the dark desert of southern Utah for the very first time are usually floored by the incredible splendor of our skies. The Milky Way stretches from one horizon to the other, a brilliant band of multicolored stars wreathed with tendrils of dark interstellar dust. The light from the stars is bright enough to find your way around by, if you let your eyes adjust to it. The planet Venus can be bright enough to cast a shadow.
The night sky is a gift to us. Its darkness, far from being threatening, speaks to our evolutionary proclivity to require deep absence of light in order to properly relax during night-time sleep. Research has suggested multiple connections between being exposed to bright lights at night and various health problems, including cancer. Along with other animals with which we share the Earth, we have evolved for millions of years to integrate the regular cycle of daily light and dark into our circadian rhythms. Too much light messes with both our heads and our bodies. We canâ€™t quit working or thinking about our day-time concerns. No wonder thereâ€™s such a strong market for pharmaceutical sleep aids.
Besides relaxing us, the deep desert skyâ€™s star-shattered glory also lifts our eyes out of the two-dimensional ground-parallel plane where we customarily dwell during the day, and invites us into thinking deeper thoughts about the Universe that surrounds our little planet. Who are we? How did we get here? What is life all about, anyway? Are there alien life forms on alien worlds circling alien stars, looking up at their own night skies and wondering the same exact things? There are few sights more inspiring than a moonless starry night, and Utahns are privileged to live within a few hoursâ€™ drive of this amazing panorama. Do yourself a favor this summer and go camping in the desert. Take your binoculars and remember to count shooting stars.
Reduce your light pollution
Even though residential lighting isnâ€™t the biggest source of light pollution, thereâ€™s a lot you can do at home to help bring back the starry skies.
First, take a look at your property and decide where you really need light, how much light you need there, and where you can do without it. Many places, such as walkways and driveways, can benefit from just accent lighting, rather than complete illumination.
Next, choose appropriate fixtures. Fixtures that allow light to escape upward not only contribute to light pollution, theyâ€™re wasteful: Upward-directed light doesnâ€™t do you any good. By picking a downward-directed fixture, a much less intense bulb can be used for the same effective lighting, saving you money. Choose fixtures that allow for the lowest necessary wattage, and pick bulbs that are toward the red end of the spectrumâ€”white and blue lights donâ€™t dissapate as quickly, contributing to night sky glow.
When placing fixtures, pick spots that already have recesses and overhangs, such as under eaves and balconies. This keeps light from escaping upward.
Rememberâ€”lack of lighting is incorrectly associated with safety. Brightly lit areas, especially with lots of glare (which causes pupils to dilate, making it almost impossible to see into shadows), create a false sense of security. People can see better in soft lighting than in spotlights because itâ€™s possible to see beyond the point of illumination. In fact, excess lighting can draw attention to a property or help a criminal see what heâ€™s doing. Illuminating an entire yard doesnâ€™t make your property saferâ€”but keeping the lights to doorways does. Motion sensor operated lights are also a good idea, since theyâ€™re only on when actively needed.
Do your best to keep light from your property from leaking into your neighborsâ€™ propertyâ€”especially keep it away from their windows. Few things are more obnoxious than a super-bright motion-activated floodlight directed at your bedroom window popping on and off all night.
For lots of great ideas, including illumination and wattage charts, as well as elegantly written sample letters to ask your neighbors to change their lighting, check out darksky.org/outdoor-lighting.