The End of Night: Searching for Natural Darkness in an Age of Artificial Light. Paul Bogard

I had expected. Until then I’m in what feels, at least late on a summer Sunday, like a forgotten part of the city. With the theater district and advertising lights moved far up the street, the once bright Way is far more mild than Great, much less White than gray.

      But once in Times Square, all that changes. Flashing digital signs, billboards, colored lights—from Forty-second to Forty-seventh is the brightest—and there is no night sky. I don’t mean I can’t see many stars, or even that I can’t see any stars, I mean there appears to be no sky. Yes, above me, there is a blackish color—but with no points of light or any other indication of being alive. Instead, I feel as though I’m in a domed stadium. The light from the digital billboards simply drowns the white streetlights that lower on Broadway seemed so bright. I can honestly say it feels as bright as day. Maybe a cloudy day, but day nonetheless. Certainly, it no longer feels like night.

      And by that I mean it no longer feels dark.

      In fact, at least in terms of darkness, “real night” no longer exists in New York City, or in Las Vegas, or in hundreds of cities across the world. According to the World Atlas of the Artificial Night Sky Brightness, created in 2001 by Italians Pierantonio Cinzano and Fabio Falchi, two-thirds of the world’s population—including 99 percent of people living in the continental United States and western Europe—no longer experience a truly dark night, a night untouched by artificial electric light. Satellite photographs of the earth at night show the dramatic spread of electric light over the globe—even without a map to show political boundaries, many cities, rivers, coastlines, and country borders are easily identifiable. But as impressive as these photographs are, they don’t show the true extent of light pollution. Cinzano and Falchi took NASA data from the mid-1990s and, using computer calculations and imaging, showed that while in the photographs many areas outside cities appeared dark, they were actually flooded by pools of light spreading from the cities and towns around them. On the Atlas, levels of brightness are indicated by color, with white the brightest, and descending from there: red-orange-yellow-green-purple-gray-black. Like the NASA photographs before it, the World Atlas of the Artificial Night Sky Brightness has a certain beauty, but in truth it is a tale of pollution.

      Light pollution is the reason Rob Lambert and I could see only a handful of stars from the Las Vegas Strip, and the reason I don’t see any stars from Times Square. It’s the reason why in the night skies under which the vast majority of us live, we can often count the stars we see on two hands (in the cities) or four (suburbs), rather than quickly losing count amid the more than twenty-five hundred stars otherwise visible on a clear night. It’s the reason why even from the observatory deck of the Empire State Building we now see 1 percent of the stars those in 1700s-era Manhattan would have seen.

      The International Dark-Sky Association (IDA) defines light pollution as “any adverse effect of artificial light, including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste.” Sky glow—on display nightly over any city of any size—is that pink-orange glow alighting the clouds. It’s tramping through a two-foot snowfall with the whole town bathed in push-pop orange. It’s that dome of light on the horizon ahead though the sign says you’ve still got fifty miles to go. Glare is that bright light shining in your eyes that you raise your hand to block. Trespass is light allowed to cross from one property onto another. It’s your neighbor’s security light shining through your bedroom window. It’s the lights on the brand-new science building that also illuminate the sororities across the street. It’s all over every neighborhood in America, land of the free and the home of property rights. And clutter? A catchword for the confused lighting shining this way and that in any and every modern city.

      A long exposure shows birds and bats hunting moths and insects amid the Luxor Casino’s beam in Las Vegas. (Tracy Byrnes)

      The bad news? All mean wasted light, energy, and money. The good news? All are caused by poorly designed or installed light fixtures and our using more light than we need, and all could be significantly and—compared to other challenges we face—easily remedied.

      When I think of how light pollution keeps us from knowing real darkness, real night, I think of Henry David Thoreau wondering in 1856, “Is it not a maimed and imperfect nature that I am conversant with?” He was writing about the woods around Walden Pond and how the “nobler” animals such as wolf and moose had been killed or scared away. “I hear that it is but an imperfect copy that I possess,” he explained, “that my ancestors have torn out many of the first leaves and grandest passages, and mutilated it in many places. I should not like to think that some demigod had come before me and picked out some of the best of the stars.” Some 150 years later, this is exactly what we have allowed our lights to do. “I wish to know an entire heaven and an entire earth,” Thoreau concluded. Every time I read this I think, Me, too.

      Bob Berman lives in a small town in upstate New York that has no streetlights. “I could never live in a place with streetlights,” he tells me as we wind along a dark two-lane road, joined by a rising moon cast over the ruffled lakes and through bare spring trees, the songs of peepers audible over the sound of the car. We are on the way to the observatory he built by himself. Once described as the country’s most popular astronomer, Berman has written a number of books, wrote the “Night Watchman” column for Discover magazine and the “Skyman” column for Astronomy magazine, and is known especially for his humorous writing style. Which is not the easiest thing to pull off when you’re writing about astronomy, he says. “Science isn’t inherently funny. What’s funny about Pluto? What’s funny about galaxies, and the cosmos, and the expanding universe? This is not social satire. When I was able to do a column on stupid questions, that was a gift from God.”

      “What was your favorite?”

      “It’s hard to top, ‘If a solar eclipse is so dangerous, why are they having it.’”

      But of course the “stupid questions” column had a serious point to make, that most Americans don’t know much about the night sky.

      I used to count myself among that number. I was always drawn to it, but I’d never known its names and numbers, its secret lives. In fact, here is what I did know: planets don’t twinkle and therefore I could supposedly tell them from stars, and two prominent constellations—the Big Dipper (which technically is only part of a constellation) and Orion.

      “That’s not bad,” Berman tells me. “The only thing most people know is the moon.”

      That I know more than I used to has a lot to do with Bob Berman, and especially his book Secrets of the Night Sky. Here’s some of what I learned: One of the stars in Orion, Betelgeuse is “the largest single thing most of us will ever see.” Sure, a galaxy is bigger, but a galaxy is a collection of stars rather than a single thing. Anyway, no galaxy is bright enough to shine through the light pollution that covers most of the developed world’s skies. “Betelgeuse, on the other hand,” writes Berman, “is brilliant enough to bulldoze its way through the milkiest urban conditions.” Or how about this: Rigel, another brilliant star in Orion, “shines with the same light as fifty-eight thousand suns.” Rigel is much farther away than the other stars making up the constellation, and, as Berman explains, if Rigel “were as close to us as the others, our nocturnal landscape would tingle with sharp, alien Rigel shadows, and the night sky would always be as bright as when a full moon is out. Most of the universe would disappear from view.”

      The moon tonight, a waning gibbous a few days past full, is bright enough that our view at the observatory won’t be as great as it otherwise might be. When, during its twenty-nine-day cycle, the moon is big enough and therefore bright enough to wipe so many stars from view, most astronomers are not excited to see it. But Berman seems genuinely delighted to roll back the roof of his DIY observatory (which he built, he says, “crazy and wrong”) and point his telescope at the moon. (“Did you make the telescope yourself?” I ask. “No, no, no,” he says. “I wanted a good one.”)

      “Here, take a look at this,” he says, and invites me to step up to the eyepiece.

      I