Picture this: Everyone you’ve ever known, everyone you’ve ever loved, your whole experience of life, floating in one place, on a single planet underneath you. On that dazzling oasis, swirling with blues and whites, the weather systems form and travel. You watch the clouds tingle and swell above the Amazon and know the weather that develops there will affect the crop yield half a planet away in Russia and China. Volcanic eruptions make tiny spangles below. The rain forests are disappearing in Australia, Hawaii, and South America. You see dust bowls developing in Africa and the Near East. Remote sensing devices, judging the humidity in the desert, have already warned you there will be plagues of locusts this year. To your amazement, you identify the lights of Denver and Cairo. And though you were taught about them one by one, as separate parts of a jigsaw puzzle, now you can see that the oceans, the atmosphere, and the land are not separate at all, but part of an intricate recombining web of nature. Like Dorothy in The Wizard of Oz, you want to click your magic shoes together and say three times: “There’s no place like home.”

You know what home is. For many years, you’ve tried to be a modest and eager watcher of the skies and of the Earth, whose green anthem you love. Home is a pigeon strutting like a petitioner in the courtyard in front of your house. Home is the law-abiding hickories out back. Home is the sign on a gas station just outside Pittsburgh that reads, If we can’t fix it, it ain’t broke. Home is springtime on campuses all across America, where students sprawl on the grass like the war-wounded at Gettysburg. Home is the Guatemalan jungle, at times deadly as an arsenal. Home is the pheasant barking hoarse threats at the neighbor’s dog. Home is the exquisite torment of love and all the lesser mayhems of the heart. But what you long for is to stand back and see it whole. You want to live out that age-old yearning, portrayed in myths and legends of every culture, to step above the Earth and see the whole world fidgeting and blooming below you.

I remember my first flying lesson, in the doldrums of summer in upstate New York. Pushing the throttle forward, I zoomed down the runway until the undercarriage began to dance; then the ground fell away below and I was airborne, climbing up an invisible flight of stairs. To my amazement, the horizon came with me. (How could it not, on a round planet?) For the first time in my life I understood what a valley was, as I floated above one at seven thousand feet. I could see plainly the devastation of the gypsy moth, whose hunger had leeched the forests to a mottled gray. Later on, when I flew over Ohio, I was saddened to discover the stagnant ocher of the air, and to see that the long expanse of the Ohio River, dark and chunky, was the wrong texture for water, even flammable at times, thanks to the fumings of plastics factories, which I could also see, standing like pustules along the river. I began to understand how people settle a landscape, in waves and at crossroads, how they survey a land and irrigate it. Most of all, I discovered that there are things one can learn about the world only from certain perspectives. How can you understand the ocean without becoming part of its intricate fathoms? How can you understand the planet without walking upon it, sampling its marvels one by one, and then floating high above it, to see it all in a single eye-gulp?

Most of all, the twentieth century will be remembered as the time when we first began to understand what our address was. The “big, beautiful, blue, wet ball” of recent years is one way to say it. But a more profound way will speak of the orders of magnitude of that bigness, the shades of that blueness, the arbitrary delicacy of beauty itself, the ways in which water has made life possible, and the fragile euphoria of the complex ecosystem that is Earth, an Earth on which, from space, there are no visible fences, or military zones, or national borders. We need to send into space a flurry of artists and naturalists, photographers and painters, who will turn the mirror upon ourselves and show us Earth as a single planet, a single organism that’s buoyant, fragile, blooming, buzzing, full of spectacles, full of fascinating human beings, something to cherish. Learning our full address may not end all wars, but it will enrich our sense of wonder and pride. It will remind us that the human context is not tight as a noose, but large as the universe we have the privilege to inhabit.

“The Round Walls of Home” is excerpted from A Natural History of the Senses, by Diane Ackerman, copyright © 1990 by Diane Ackerman. Used by permission of Random House, an imprint and division of Penguin Random House LLC. All rights reserved.