The airplane’s nose is tracking just a few points off due east through the cold, clear air. Several hours earlier while I was on break and trying my best to get some sleep in the back, for just over 300 miles, we rode the core of a jet stream. While I tossed and turned in a less than comfortable lay-flat seat, the captain flying the plane pushed the power up slightly to—assisted by 200 knots of wind whistling around the curves of the earth—break his personal ground speed record and fly at just over 800 miles per hour over the unseen waters of the northern Pacific some 39,000 feet below...

The double-paned window is cold to the touch and the back of my hand leaves behind a smudge of condensation when I pull it away from the glass. I watch the moisture fade, evaporating into the relatively warmer air of my hotel room, as finally, I begin to feel the stress of the last few hours of flying lift from my shoulders. I spin the padded office chair I’m sitting in around to face the room, and then stand up and roll my shoulders several times. The spot that has been bothering me behind my right shoulder blade pops, the noise jarringly loud in the empty space, and I grunt with satisfaction...

I blink rapidly as I step into the light-filled cockpit, after the darkness of the business class cabin. The Relief Officer, who has spent the last four hours, along with the Relief Captain, navigating us westward while the captain and I were on our rest break, slides past me and steps out of the cockpit. Still squinting slightly, I sit down in the empty right seat. While I click my seatbelt into place and adjust the seat position, the Relief Captain, who is still flying the plane, briefs me on where we are and what’s been happening, and hands control of the plane over to me. He then unclicks his seatbelt, gives up his seat to the captain, and moves to the jump seat, where he will remain for the rest of the flight..

We track eastward underneath a darkening sky that arches high overhead, cascading downward like a dome, its bottom edges holding the dull orange glow of the just set sun. The moon, mere hours from the fullest point of its 29 day cycle, has been sliding upwards from the fuzzy terminator line of earth and sky for the last hour, a bright white marble against the deepening blue of the heavens...

We seemingly hang in a deep azure blue sky, swimming slowly upstream against a river of wind that continually circles the globe in meandering arcs. This Jetstream wanders, sometimes to the north, then south, then north again, but is always moving eastward, driven by the complex mechanics of planetary rotation. I close my eyes, the bright sun warm on my face, and try to build a mental visualization of the airflow around our blue marble, but quickly realize that I can’t hold the complexity in my head...