Thanks to light pollution, most of us have never seen the night sky in all its wonder. But a new mindset and new technology are poised to slow — and perhaps reverse — this bane of modern life.
Imagine driving through town as every fire hydrant gushes water into the street. Or stepping outside to find that the sprinkler system next door has gone berserk and is drenching the side of your house with a steady stream of water.
That situation wouldn't last long — you'd quickly be giving city hall and your neighbor an earful about it.
So why do we put up with the waste of so much light at night? Light pollution, simply put, is any unnecessary or excessive outdoor illumination. Sadly, it's become a pervasive and ugly consequence of modern 24/7 society.
Look around you the next time you're out at night. Much of the intense light generated by roadway and security fixtures never touches the ground. It never lights anyone's way, never provides any security, visibility, or guidance.
Instead, it shines straight up into the sky. That ugly orange pall that envelops every city skyline is a collective consequence of all the streetlights that line our roadways, the over-the-top lighting at fast-food restaurants and gas stations, and even the intrusive glare from a neighbor's security light.
It didn't used to be this way.
Electric streetlights have been around for more than a century, but it wasn't until the 1950s that General Electric and Westinghouse lined America's roadways with millions of "cobra-head" streetlights that remain today.
Then, around 1970, light bulbs filled with high-pressure sodium gas began to blanket the landscape with their dazzling, ubiquitous, peach-colored glare.
Without question, certain nighttime situations do require illumination. You wouldn't use an unlit ATM, or fumble in the dark with a gas pump. But when it comes to outdoor lighting, more is seldom better.
Today, lighting scientists report, 99 percent of Americans live with light pollution to varying degrees, and more than two-thirds of us can't see the star-spangled Milky Way from our backyards.
Light pollution robs us of more than the night sky's beauty. It's an in-your-face waste of energy.
According to an estimate by the international Dark-Sky Association, skyward-directed light squanders more than $2 billion in electricity in the U.S. every year. Poorly designed lighting causes harsh glare that can blind and distract drivers, especially in bad weather and for elderly drivers with poor vision. Over-lit buildings disorient many birds, especially during their seasonal migrations, causing death due to impact or predation.
More ominous is a growing body of research suggesting that excessive light at night can disrupt the production of melatonin, a compound produced as we sleep — and only in darkness — that seems to play multiple roles in maintaining general human health.
Clinicians around the world are racing to find out how disrupted darkness might impair the circadian (day-night) cycles, and two months ago the American Medical Association released a report titled "Light Pollution: Adverse Health Effects of Nighttime Lighting."
Fortunately, the spread of nighttime sky-glow can be easily halted and even reversed. The most effective remedy is both simple and cost-effective: just make sure that all the light is directed downward, by using fixtures that send all their light below horizontal.
Look around, and you'll see that most modern businesses use these "fully shielded" lights extensively — not because they're dark-sky devotees, but because doing so saves energy and money.
To its credit, the Maine Legislature has been better than most in addressing outdoor-lighting issues. Since 1991, outdoor-lighting fixtures must be fully shielded if state funds are used for the project that installed them. This requirement also applies to state-owned streetlights, as well as on state university campuses and at other state-owned facilities, including parking lots.
More broadly, lighting engineers are abuzz about the potential for light-emitting diodes to take energy efficiency to a new level. Although they're only now becoming as efficient as existing streetlights, the trend is clear: soon they'll illuminate practically everything, including our roadways.
Best of all, LEDs are inherently directional — they must be pointed toward their target, so they have the potential to revolutionize outdoor lighting in a profoundly positive way.
But we don't have to wait for LED technology to mature in order to start reducing light pollution. Just tilting a spotlight downward or equipping it with a motion detector would be a start.
Make sure new construction, whether municipal or commercial, utilizes fully shielded outdoor lighting. Even these small efforts will help ensure that the pristine night skies for which Maine is so well known will stay that way — now, and for generations to come.
J. Kelly Beatty chairs the New England Light Pollution Advisory Group.