Skyfaring: A Journey With a Pilot (33 page)

If the plane heads west, however, its direction is opposed to the rotation of the earth. So the plane remains on the front of the ring, in the daytime, the day-place. That is the long day we experience on a westbound daylight flight. Meanwhile the city we departed from is turning away, reaching dusk when and where we would have met it, had we not earlier in the day boarded a westbound airliner. In terms of light, this is what it means to fly from Singapore to Dubai, Muscat to Casablanca, Atlanta to Honolulu. We arrive in the heat of our destination’s afternoon even as the city we departed from has been dark for hours.

Marilynne Robinson, in
Gilead,
describes our rotation in the night ring, our transit of the sun’s perpetual light, in language that every pilot will recognize:

This morning Kansas rolled out of its sleep into a sunlight grandly announced, proclaimed throughout heaven—one more of the very finite number of days that this old prairie has been called Kansas, or Iowa. But it has all been one day, that first day. Light is constant, we just turn over in it.

The truth of this, seen from airplanes, is all but religious in both weight and simplicity. At many latitudes darkness need never come to a westbound airplane, for as long as it can fly.

A plane may remain in the day like this—or in the night, or on the boundary between the two. Sometimes a westbound flight departs near dusk, the time and place at the edge of the ring. If it had remained at the airport, night would have fallen on it. But it did take off and head west, and the brief hour of dusk may now last for the entire flight; a dusk as long as a day, made at the ending of the day. Something I see often: to one side the sun, below a white subarctic landscape lit lipstick-pink by the sear of low sunlight, and across the sky—I have only to turn my gaze—the curve of night following us like an apparition.

Such a dusk, though seemingly permanent on some flights, is not stationary. Leaving London for Vancouver on an autumn afternoon, we start by heading roughly north, and the sun is already setting to the west, to our left. In the middle of the flight it may be ahead of us, on the nose. Then, near the end of the flight, when we approach Vancouver heading nearly south, the sunset is on our right, having moved around the horizon as ordinarily as the hand of a clock or the shadow of a sundial.

—

The days and nights of flight are scrambled by a further detail. Imagine again the flashlight and the ring of light and dark it casts around the apple. Now imagine a pencil passing through the apple from top to bottom, the eraser where the apple’s stem is, the pencil tip coming out of the bottom. The earth’s axis—the pencil, the line from the North Pole to the South Pole along which the earth spins—is tilted. It does not pass through the night ring, the rim of the hula hoop, except at the spring and autumn equinoxes, when the sun is directly over the equator.

For part of the year the eraser of the pencil is inclined toward the sun, as if you tilted the apple so that the eraser leaned out toward the flashlight. This tilt is the source of the seasons and of the changing lengths of days throughout the year. When the top of the apple gets more direct light, and for more hours of each day, it is summer in the northern hemisphere. And because the top of the earth is tilted forward in the ring, the area immediately around it turns around and around without ever crossing the night ring, and here, therefore, for part of the year the sun never goes down. Indeed, this is one formal definition of the Arctic—the portion of the northern world where the sun remains above the horizon for at least one entire twenty-four-hour period in the light course of the year.

Meanwhile, at the bottom of the apple, the pencil tip sticks out the back of the ring. This is winter in the southern hemisphere, and the area of the apple around the pencil tip never turns into the front of the night ring—the perpetual night of the Antarctic. All this reverses later in the year, when the pencil eraser points out the back of the ring and the tip out the front. Summer and light fly south, as simply as 747s, or the Arctic terns that permanently bounce between summers and so may experience less darkness than any other animal.

The tilt of the earth’s axis results in further airborne idiosyncrasies. When the Arctic lies in perpetual darkness, then even on a westbound, so-called daylight flight—from London to Los Angeles, for example, which takes off in the afternoon of London and lands in the afternoon of Los Angeles, never once overflying a place where the local time is not afternoon—the great circle of the flight path nevertheless may take us not only into the geographic north but geographic night. We cross the dusk–dawn ring near the top; we fly into the volume of darkness that rests upon the night lands. The sun may set entirely. The stars come out. And then, some time later, as the great circle curves back toward the south, we cross once more into the front of the ring to experience a second dawn to our day. An observer on the ground below, meanwhile, might see something of this same light in the sky and would call it dusk.

Sometimes this new dawn, this new day conjured up by the plane, will last for hours; it may turn into something approximating open daylight. Other times the sun reverses direction and the dawn retreats; after our extra sunrise, another sunset. And then? I have been on flights where the sun has set and then risen three or four times. In ordinary terms—the day as the time between sunrise and sunset—I do not know how many days one day can hold.

On eastbound flights in the northern hemisphere’s summer, when the far north is in perpetual light, other violations of solar decency occur. On a so-called overnight flight from Europe to the Far East we head northeast, and the sun moves behind us. It lowers in the sky but it does not set. Then it swings across the sky, from left to right, until it is due
north
of us. We are watching an entire day take place on the other side of the planet, watching it over the top of the world, where it appears as something we might call a north-set, or a north-rise, blessing us with half a dozen hours or more of the golden-hour light so valued by photographers.

On such flights I have seen the red low sun hover over the far side of the earth, and I have mulled over several hours and cups of tea whether the boreal maneuverings of our jet and star are best described as dawn or dusk, and whether the light seen from the north is yesterday or tomorrow. Finally the sun completes its lap and appears at last where it must if it is to grace the morning of our destination—Tokyo, say—roughly in the east.

These light effects are often masked by the blinds in the passenger cabin, whose function is to block light but which also temporarily dam up the airplane’s time-scrambling stream of motion. Most passengers want to sleep on an eastbound overnight flight and so the rise of the sun a few hours into their journey—if it ever set in the first place—must be hidden. Sometimes I walk in the passenger cabin and it is almost entirely dark. Nearly every passenger is trying to sleep. When I return to the flight deck, and the door between the cabin and the cockpit opens, the full brightness of the new world tumbles out like tools from a badly packed cupboard, dust swirling in the blade of light that falls onto the cabin floor.

—

In
Wuthering Heights
Cathy ponders the vertical geography of light. The high Penistone Crags “attracted her notice; especially when the setting sun shone on it and the topmost heights, and the whole extent of landscape besides lay in shadow.” Higher up, the horizon recedes, as it does when you climb a tall building. You see more of everything, more of the sky and more of the sun. The day will find you in the sky before dawn arrives on the earth below, and in the evening, dusk will reach you some time after it has already covered the earth. This is why the sky lightens before dawn and why light lingers in the sky after dusk. We may be pleased by the still-glinting wings of an airliner high above us, leaving a contrail soaked in crimson light, while at street level the sun has already set. We see the plane we are not on, bound for a place we are not, in the last light of the day that has already left us.

When we’re flying at dusk, perhaps the sun at last slips below the horizon. Then we climb a few thousand feet, and the sun starts to rise again, in such neat concert with the plane that at such moments it seems particularly absurd to think of light as a function of time rather than space. When I flew on routes around Europe, many winter flights started or ended in darkness. On early morning departures from Lyons or Vienna or Paris we would climb rapidly, passing from a dark, frosty runway into the pure, early sunshine of the day that above us was already dawning. Then in the evening, from the glorious light of a sun not quite below the horizon, we would descend to where it had already set, and from there into a further-fallen night.

There are memorable words for the formal gradations of low light. As the sun begins to move below the horizon, first comes
civil twilight.
Next comes
nautical twilight,
which measures out the last light in which the horizon is visible at sea, an important consideration in old-school navigation. Finally comes
astronomical twilight,
when the sky is dark enough for most observations of the heavens to begin. In aviation, various rules hinge on the definition of daylight—for example, the lighting that’s required to be working on the plane or on the runway. A typical aviation definition of day is the time “between the beginning of morning civil twilight and the end of evening civil twilight relevant to the local aeronautical airspace.”

In the cockpit we have a book filled with pages and pages of tables that tell us when the sun will rise and set across the world. Its sobriety is an antidote to the antics of the sun, and by reading the entries for en-route cities, we can guess what light we will have when we pass near them. There’s no obvious grandeur to this book of light, its utilitarian numbers and place names densely set on sheets as thin as newsprint. Yet when I remove it from its cockpit stowage it feels like a future artifact: a book of the days of our cities, a slender volume from the library of the vessels that cross the rising and falling light between them.

—

One of my father’s former colleagues from his time in Brazil still lives in Salvador, on the country’s vast northeastern coastline. Eduardo is now in his eighties. As we have known him our entire lives my brother and I call him our uncle; Uncle Eduardo, his Flemish name Brazilianized as my father’s was, from Jozef or Jef to José (a version my dad liked so much that he kept it when he moved to America). Once every two or three years Eduardo travels from Salvador to his native Bruges. He tells me that he always chooses his seat carefully on these long night flights, usually opting for the east side of the plane—the right side as he travels north. This is so he can see the dawn and the first landfall over Europe, he explains when asked, as if such imaginative legroom were every traveler’s most obvious consideration when choosing a seat.

Eduardo once asked me if what seems to him to be true—that he can see the day coming from almost an hour away—is really the case. He’s right. The clarities of the high night and day are so pure that each intrudes early on the other, each giving the other away, like small children who point at one another and laugh in response to a good-natured interrogation. He tells me that he loves to watch dawn’s steady migration of color, the expanding new blues that arc like ripples into the starry black. He says, with a smile, that he could watch forever.

When he is asked by the flight attendants to close the blind, so as not to disturb the other passengers, he instead places a blanket around the window and continues to peer from under it. He’s watching his journey up and across an ocean, his rare trip north, along the line from his near-equatorial garden of cacao and cinnamon to a country—his, my father’s—where people marvel at a vocabulary and accent they now find nearly antique. He is watching the sky and the airplane, their beautiful conflation of time and distance with his time, his distance.

The next time you are in a plane with the sun setting somewhere on the other side of it from you, look toward the sky roughly opposite from where the sun is setting. The sky right above may be almost white, but as your eyes approach the horizon opposite the setting sun, it turns pinkish and then collapses into a fabulous series of blues—more blues than any terrestrially born language would ever go to the trouble to name.

Among the wordless blues is a sight I did not know to look for when I started to fly. If I had known I might have become a pilot much sooner. There is a wedge of darkness—a much darker blue—that starts near the horizon from about 90 degrees on either side of where the sun is setting. An astronomer tells me his mother called this “the blanket of night,” as we see it pulled over the world. This sublime slice of midnight blue grows as you move your eyes toward the point on the horizon opposite the point of sunset. This darkness is the shadow of the earth itself, projected onto a screen of air. It is sometimes called the
dark segment
and can be seen from the ground, too, in the right conditions.

There is an early Islamic title, the “Shadow of God on Earth,” used by Suleiman the Magnificent and the last Shah of Iran. Here, instead, we see the shadow of earth on the heavens. This shadow—the same that falls over the moon during a lunar eclipse—is very slightly curved. Many intimations of the earth’s shape are available to us. But aside from during an eclipse, few of us will ever have the chance to look for the roundness of our planet as directly as we do at nearly every dusk and dawn in an airplane, when we only turn to the window and lift the intervening blind.

—

My mother liked to give me books on the sky when I was younger, of the sort that mix scientific details with artistic images and tales of how various peoples and ages have interpreted the heavens. She might tuck into such a gift a note, or perhaps a copy of the lecture she had recently heard—by a world-class astronomer, for example, who had started their training in a Tibetan Buddhist monastery.