The End of Night: Searching for Natural Darkness in an Age of Artificial Light. Paul Bogard. Читать онлайн. Newlib. NEWLIB.NET

Автор: Paul Bogard
Издательство: HarperCollins
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Жанр произведения: Прочая образовательная литература
Год издания: 0
isbn: 9780007428229
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but this moon seems cold, antiseptic—alone in the unfathomable expanse of space. I learned a lot about the moon from Berman’s writing (“it’s more brilliant when it’s higher, when it’s nearer, and in winter when sunlight striking it is seven percent stronger”), and I appreciate this kind of information. But I think our relationship with the moon has more to it than simply astronomical facts. With my naked eye, on nights the moon climbs slowly, sometimes so dusted with rust and rose, brown, and gold tones that it nearly drips dirt colors and seems intimately braided with Earth, it feels close, part of this world, a friend. But through the telescope the moon seems—ironically—farther away.

      “So now we’ll go to Saturn,” Berman says. Using both arms, he moves the large white telescope as though leading a dancing partner, turning it slightly to the east, then steps up the ladder and adjusts the view. “Now we’re talking,” he says. When I look through the scope, though, the bright tiny object is dancing around, and the image is blurry. Berman takes another look and makes some more adjustments, explaining as he does the key elements for viewing the night sky: transparency, darkness, and “seeing.” Yes, that’s what they call it. “You would think astronomers would come up with a more technical term,” he chuckles, “but no, all around the world astronomers are saying, ‘The seeing is a three point five tonight.’” Seeing reflects the effect of turbulence in the earth’s atmosphere on the sharpness and steadiness of images—good seeing if the atmosphere is steady and calm, bad seeing if it is especially turbulent. A quick way to check seeing is how strongly stars twinkle: The more the twinkling, the worse the seeing. Berman tells me that bad seeing is one reason why no major observatories have been built east of the Mississippi for more than a century. The good “seeing” atop mountains in the desert has drawn astronomers west.

      “Take a look at that,” says Berman, climbing down. “Wait for the moments of good seeing—when it steadies up.” Waiting for that—for good seeing—is exactly what an experienced observer will always do, he says. “I remember once when I was about twenty-four, and it was thirteen below zero, and my beard was frozen, I just stood there for three straight hours waiting for those moments when there would be steadiness and you could see ring within ring, detail that even photographs don’t show. That’s what observers have done for centuries.”

      As I wait for good seeing, I think about what Berman’s just said. While humans have always watched the sky, modern astronomy has its origins in the lands we know as Egypt and Babylon, in the third and second millennia before Christ. People then were looking to the sky for signs and omens (though of course they were looking in other places, too; “the entrails of sheep were of special interest,” writes historian Michael Hoskin). Eventually, the cosmology that developed—the classic Earth-centered Greek model of the universe—would dominate Greek, Islamic, and Latin thought for two thousand years. During the Middle Ages, astronomy in Europe was truly in the Dark, and not in the way modern astronomers would like—we have Islamic astronomers to thank for keeping the craft alive. That’s the reason so many stars have Arabic names; one Islamic prince named Ulugh Beg, who lived from 1394 to 1449 in Samarkand in central Asia, catalogued over a thousand individual stars himself. And when, in 1609, Galileo Galilei (1564–1642) turned his handmade telescopes toward the sky, human observation of the cosmos changed forever.

      When the “seeing” settles and Saturn comes into view, I can’t help but say, “Oh my God!” To the naked eye Saturn is simply a bright starlike object—interesting, perhaps, but nothing more. But seen through a telescope it’s a soft yellow marble with wide, striated rings—exactly as in photographs, but this time alive.

      “Over the years more than a thousand people have looked through that telescope,” Berman says. “And with Saturn, people always say one of two things. They either say, ‘Oh my God!’ or they say, ‘That’s not real!’”

      That’s not real—what a curious response. I’ve had other astronomers tell me the same thing, or say that people will question whether the astronomer hasn’t placed an image of the planet into the telescope somehow. The fact that people are seeing something with their own eyes has incredible power—you can see photographs of Saturn a thousand times and be somewhat impressed, but see it for yourself and you don’t soon forget.

      The most beautiful starry night I have ever seen was more than twenty years ago, when I was backpacking through Europe as an eighteen-year-old high school graduate. I had traveled south from Spain into Morocco and from there south to the Atlas Mountains, at the edge of the Sahara desert, to a place where nomadic tribes came in from the desert to barter and trade, a place that when I look on a map I can no longer find. One night, in a youth hostel that was more like a stable, I woke and walked out into a snowstorm. But it wasn’t the snow I was used to in Minnesota, or anywhere else I had been. Standing bare chest to cool night, wearing flip-flops and shorts, I let a storm of stars swirl around me. I remember no light pollution—heck, I remember no lights. But I remember the light around me—the sense of being lit by starlight—and that I could see the ground to which the stars seemed to be floating down. I saw the sky that night in three dimensions—the sky had depth, some stars seemingly close and some much farther away, the Milky Way so well defined it had what astronomers call “structure,” that sense of its twisting depths. I remember stars from one horizon to the other, stars stranger in their numbers than the wooden cart full of severed goat heads I had seen that morning, or the poverty of the rag-clad children that afternoon, making a night sky so plush it still seems like a dream.

      So much was right about that night. It was a time of my life when I was every day experiencing something new (food, people, places). I felt open to everything, as though I was made of clay, and the world was imprinting upon me its breathtaking beauty (and terrible reality). Standing nearly naked under that Moroccan sky, skin against the air, the dark, the stars, the night pressed its impression, and my lifelong connection was sealed.

      When I tell Berman about Morocco he says, “A sad corollary to that story is when my wife’s mom visited us once. And she had spent her life living in either Long Island or Florida, light-polluted places. We heard the car drive up, heard the trunk close, heard her wheel her luggage to the house, and when she came in she said to Marcy, ‘What are all those white dots in the sky?’ And of course Marcy said, ‘Those are called stars, Mom.’”

      “I’ve heard people say such things,” I laugh, “but I can’t believe they’re true.”

      Berman leans back and calls, “Marcy, do you remember when your mom said what are those white dots in the sky?”

      “Yep.”

      “Do you think she was kidding?”

      “Nope.”

      Seeing stars is something Bob Berman has done all his life. And here in upstate New York, the sky still offers a wonderful view.

      “We get down to about magnitude five point eight, five point nine, where you see a good twenty-five hundred stars,” he says, referring to the scale astronomers use to describe the brightness of individual stars. “Theoretically, three thousand stars are visible to the naked eye at one time, but, in truth, since the overwhelming bulk of stars are fifth and sixth magnitude—the fainter you go, by far the more stars there are—and because extinction near the horizon is so great, the truth is faint stars stop at about ten degrees from the horizon and you lose a swath.”

      We adopted the idea of magnitude from the ancient Greeks, who called the brightest stars “first magnitude” and the dimmest “sixth magnitude.” When modern astronomy put precise measurement to the Greek magnitude idea, a few of the brightest stars actually turned out to have minus numbers, such as Sirius (-1.5). But these values are all relative, reflecting only how we see these stars from Earth. The brightest star in the history of the universe could be fainter than faint if it’s far enough from our view.

      It’s commonly accepted that the naked-eye limit is magnitude 6.5, though some observers report magnitude 7.0 or better. As Berman writes,

      There are few brilliant stars, many more medium ones, and a flood of faint stars. This hierarchy continues with a vengeance below the threshold of human vision. Recent advances have allowed telescopes to detect stars of magnitude 29—more