The moon was only a quarter full in the wee hours of January 17, 1994, when a magnitude-6.7 earthquake struck Los Angeles, Calif. With electricity out in large swaths across America’s second-most populous city, thousands of disoriented residents stumbled into pitch-black streets to assess the damage.
High above Hollywood, the Griffith Observatory received scores of phone calls. Why were there so many stars? What was that shimmering grey cloud stretching out from the horizon? Did the strange sky cause the quake?
In the midst of tragedy, Angelenos were treated to a sight normally unseen from a bright city: the Milky Way. It takes a dark sky to see the band of starlight emanating from billions of stars near the center of our own galaxy, a view that has gradually disappeared under the glare of electrically-lit progress.
In Arizona, where space sciences are worth an estimated $250 million annually, bright skies are a serious threat to astronomical research. Cities like Tucson have adopted lighting ordinances to protect the industry, but as urban sprawl increases, bad lighting affects more than stargazing scientists. Energy is wasted. Wildlife is threatened. Human health is impacted.
For Scott Kardel, the battle starts with changing public perceptions on what makes for safe lighting. Kardel is the managing director of the International Dark Sky Association, a worldwide advocacy group for natural nights.
"Many times when the whole concept is suggested, there's an immediate reaction of, 'oh, dark skies, that sounds dangerous,” he says.
“There's an inherent fear of the dark that most people have.”
One of the biggest challenges Kardel and the IDA face is convincing communities that brighter is not always better when it comes to safe streets and crime prevention. A 1997 study by the National Institute of Justice found no conclusive link between lighting and crime levels. In fact, says Kardel, improper lighting might actually aid intruders.
"Really bright areas and really dark shadows aren't easy for the eye to process. If you look at a really bright light, your eye will tend to adapt to that by having your pupils close down, and that means your visibility into the shadows is effectively gone,” he explains.
The concept also applies to streetlights and intersections, according to Connie Walker, a senior science education specialist at the National Optical Astronomy Observatory. Walker wistfully remembers the start of her astronomical career at Maria Mitchell Observatory on Nantucket Island, Mass., where she first realized the effect city lights have on the night sky.
“We would sneak onto the beaches on Nantucket Island and just lay out there for almost the whole night, just staring at the night sky, and it just dawned on me that there was a striking difference between the skies in the Boston area and the skies out on Nantucket Island,” Walker says, adding that the experience is what inspired her to later put her Ph.D. to use for public awareness.
“I knew from then on that there was something that I had to about it at some point in my career.”
Walker lays out a cartoon map of a four-way residential intersection, and carefully places three toy cars on the streets and a few plastic figurines on the sidewalks. She sets a small flashlight, sans lens cap, in the center, simulating a streetlight. Then, she turns off the lights in the room.
The effect of the simulation is dramatic. It is hard to look at the exposed bulb, which creates considerable glare for the vehicles. Meanwhile, the plastic figurines are barely visible in the deep shadows surrounding the unhelpful streetlight.
Now, Walker produces what looks like the cap from a can of spray paint and lowers it over the light. The glare is gone. Light is redirected into the intersection where it is needed. There will be no plastic toy pileup in this cartoon neighborhood.
Better yet, the mock streetlight’s wattage could be lowered, since the light is being used more effectively.
“You’ve saved energy, you’ve saved money, and you’ve made the place a whole lot safer,” says Walker with a smile. These are the standard talking points for dark sky advocates like Walker and Scott Kardel. They tend to list the astronomical benefits last when building their case.
"There's an education process that has to happen to let people know that we're not trying to do something that's going to be bad for them,” Kardel says.
“If you can get rid of glare, if you can get rid of light trespass, if you can save energy, this is something that's good for cities. And as a side effect, you're going to see some more stars."
For a porch light that burns from dusk to dawn, a homeowner that replaces an unshielded 60-watt fixture with a 15-watt enclosure can save up to $30 per year. Motion sensors or timers can be installed to curb usage even further.
This can add up to big savings not just for homeowners, but for cash-strapped localities. The city of Calgary in Alberta, Canada is saving an estimated $1.7 million per year after overhauling their public lighting, according to the International Dark Sky Association. The IDA also estimates that in the United States alone, $2.2 billion is wasted annually throwing light needlessly into the night sky. This creates 14.7 million tons of extra carbon dioxide emissions each year.
Designing energy-efficient, dark sky-friendly lighting runs in the family for Chris Monrad. His father helped design Tucson’s original lighting ordinance in the 1970s, and founded Monrad Engineering in 1982. Chris has been aboard since 1988.
At his company’s office, stacks of blueprints fill large drafting tables. A signed thank-you letter from famed science fiction author Arthur C. Clarke adorns the reception area. Massive Milky Way panoramas hang on several walls.
“Our firm doesn’t design light fixtures per se, but often times we have a need to adapt existing technologies to suit projects’ specific needs,” Monrad explains. As a result, the company has created a deep catalog of custom lighting solutions they’ve worked with manufacturers to create over the years.
The end goal, Monrad says, is “to help put the light on the task at hand and not spill it into areas where the light is not needed.”
In one room, a variety of commercial-grade light fixtures are arranged on the carpeted floor. Monrad shows off a few devices dotted with tiny light-emitting diodes, known as LEDs. They provide a cleaner, whiter light than traditional low-pressure sodium bulbs, which are often found above intersections and parking lots emitting a dim, yellow glow.
There’s just one problem: astronomers prefer those bland sodium bulbs, which only emit light in a narrow slice of the electromagnetic spectrum, making them easy to filter. LEDs send out the equivalent of an entire rainbow of colors.
Monrad has a simple, low-tech solution: plastic yellow filters attached directly to the fixture. He gestures to a set bound for Hawaii, where astronomy is big business.
The company has designed lighting solutions for an impressive roster of clients, including airports, schools and national parks.
The latter is particularly important to Kevin Poe, a Park Ranger at Utah’s Bryce Canyon National Park. Speaking at the International Dark Sky Association’s 2012 annual meeting in Tucson, Poe lauds the efforts of his “Dark Rangers,” a telescope-wielding group of Park Rangers that are, as Poe’s website says, “sworn enemies of light pollution.”
Like many, Poe is in this fight because he loves astronomy. But he’s also deeply concerned about the effect light pollution has on his park’s wildlife.
“I’ve found that talking to people to say, ‘please protect the night so I can enjoy my nerdy little hobby, and not have to buy a bigger and more expensive telescope,’ really doesn’t resonate with people,” he jokes to the audience.
“But when you talk about the protection of the furry creatures in particular, that becomes much more important.”
Anyone with an outdoor light can attest to how insects gather around a light source. It’s a particularly appetizing scene for so-called “commuter bats,” which often fly miles out of their way to gorge on easy suppers, only to expend most of their freshly-acquired energy on the way home. Consequently, they may be too exhausted to nurse their young.
Bright outdoor lighting also creates a deadly distraction for migrating birds, which may be drawn off course into unfamiliar territory. Many crash into lit city buildings, or circle a light source aimlessly until they fall to the ground in exhaustion. The International Dark Sky Association estimates 100 million birds die each year in North America as a result.
Unnatural nighttime lights also decrease animal reproduction rates, drastically shrinking populations.
“High-quality darkness should be quite noisy,” says Poe, clicking his mouse to unleash the sounds of a mountain lion in “the advanced stages of courtship.” Light can also affect wildlife food chains by changing the behaviors of both prey and predator.
For humans, a predictable cycle of night and day is required to regulate circadian rhythms. Either too much or too little light can lead to depression. During winter, shorter days can cause seasonal affective disorder. Too much artificial light, on the other hand, comes with its own set of problems. Connie Walker says that night shift workers are particularly vulnerable.
“A lot of people have sleep disorders and they don’t realize it’s because of light that’s in their room, either because they have some light on, or because there’s light trespassing from outside,” she says.
Darkness is required to trigger the brain’s production of melatonin, an antioxidant that can inhibit the reproduction of cancer cells. As a result, the American Medical Association has listed artificial nighttime light as a possible carcinogen. The International Dark Sky Association also indicates light has been linked to cardiovascular disease.
In Tucson, responsible lighting practices have left the night sky dotted with hundreds of stars. But even so, throughout most of the city, the Milky Way is no longer visible. In many metropolitan areas around the world, it may seem as if the battle has already been lost, as the sky glows with a haze of orange city light.
Chris Monrad thinks that the tide can be turned.
“For too long, we’ve all just been used to business as usual with dusk to dawn lighting almost everywhere you might travel throughout this country,” he says.
“It’s a legacy that needs to change.”