To know the dark, go dark. Go without sight,

And find that the dark, too, blooms and sings,

And is traveled by dark feet and dark wings.

— Wendell Berry

In movies, books and media imagery, darkness often connotes danger and dread. This ingrained cultural association leads us to equate light with safety. Fearing shadowy realms, we try to banish the night in a flood of streetlights, spotlights, fog lights and “security” lights.

There’s little evidence that these lights deliver on their promise to reduce crime and improve safety. Glaring lights along roadsides actually force eyes to adjust rapidly between darkness and light, a transition that can make driving more dangerous.

Chasing back night with extravagant lighting has distanced us from the mystery of a world “traveled by dark feet and dark wings.”

Robert McCloskey immortalized these dimensions of night in his classic “Time of Wonder.” Two watercolor images capture night descending over Penobscot Bay as his daughters explore in a dinghy. His text invites readers into the tranquil scene. At first, he concedes, you can feel “lonely” in the deepening twilight, “until an owl asks a question, a heron croaks an answer.” As your senses waken, you realize that countless listening and watching beings surround you, and that the bounds of kinship extend so far that even remote stars feel close – their reflections in the water about you.

The night sky over Maine is not as brilliant as it was more than 50 years ago when McCloskey painted those images. But much of the state has been spared the light pollution overtaking the eastern United States – erasing celestial views in a yellow-orange haze of artificial light. Look at NASA’s Blue Marble navigator for a bird’s-eye view of this runaway illumination.

Many urban residents can no longer glimpse familiar constellations, and fewer and fewer young people have ever seen the Milky Way. As poignant as these losses are, light pollution poses far more serious threats – recounted in Paul Bogard’s compelling book “The End of Night.”

Nearly every creature on Earth has evolved in response to a world of bright days and dark nights, Bogard observes. Widespread artificial lighting disrupts that age-old pattern, upsetting the circadian rhythms of countless species – including our own. “Light is a powerful biological force,” notes Verlyn Klinkenborg in his essay “Our Vanishing Night,” “and on many species, it acts as a magnet.”

The lure of artificial light can have devastating consequences for wildlife. Hundreds of bird species migrate at night, forming what writer Henry Beston called “a river of life flowing … across the sky.” Disoriented by lights, birds can end up off course, dying from exhaustion or collisions. Ornithologists estimate that between 100 million and 1 billion birds are lost each year due to both daytime and nocturnal encounters with structures like oil rigs, cell towers and high-rise buildings (see flap.org for more).

Light pollution also disrupts established patterns of competition, predation and reproduction in wildlife, exacerbating the challenges animals face from habitat loss and climate change.

Even within our own species, relentless lighting takes a toll. Sleep disruptions are epidemic, with an estimated 50 to 70 million Americans having sleep disorders. Light at night can disturb rest, particularly the blue light characteristic of monitors, televisions and tablets – which appears to be particularly effective at suppressing melatonin production.

People required to work in brightly lit settings at night fare the worst. The extended light exposure and sleep deprivation associated with night shifts correlates strongly with cardiovascular disease, obesity, diabetes, substance abuse and cancer. Steven Lockley, a neuroscientist at Harvard Medical School, suggests in “The End of Night” that our focus on the health impacts of diet, exercise, smoking and alcohol may soon be eclipsed by a larger concern: “As we learn more about the impact of poor sleep, it may outstrip them all.”

As the high costs of light pollution become evident, a few communities are taking measures to reduce excessive and inefficient lighting. The town of Bar Harbor, which hosts the Acadia Night Sky Festival (www.acadianightskyfestival.com) each fall, enacted a light ordinance in 2009 to help protect the night sky experience of island residents and park visitors.

The International Dark Sky Association (darksky.org) offers guidance and resources to help select appropriate lighting fixtures. To get improved aesthetics, greater energy efficiency, healthier residents, thriving wildlife and fewer greenhouse gas emissions all in a simple switch of lighting fixture is quite a sustainability coup. It would seem like a blindingly obvious step for communities to take.

To adapt these practical steps, though, we will need to face the spiritual challenge of accepting night on its terms. “If outer darkness is the cloud where we store our inner fears,” writes Barbara Brown Taylor in “Learning to Walk in the Dark,” “how much will the real world suffer from our collective fear of the dark?”

The health of our psyches and our world depends on acknowledging what Robert Frost called the “empty spaces between stars” and the “desert places” within us. Making peace with inescapable darkness can be as humbling and grounding as an encounter with a brilliant, starlit sky.

Marina Schauffler, Ph.D., is a writer who runs Natural Choices (naturalchoices.com).