Zoom: From Atoms and Galaxies to Blizzards and Bees: How Everything Moves (7 page)

Recently there’s been more reassuring news. It seems our magnetic field does not vanish during those centuries when a reversal is trying to establish itself. Rather, many new magnetic poles chaotically come and go, with our field altering its appearance but remaining more or less intact.

Anyway, analysis shows that even without a magnetosphere, our atmosphere blocks most incoming radiation. We’d lose only a frosting of protection. It’s like a professional carpet cleaning—nice but not strictly necessary.

It’s been 780,000 years since the last pole reversal. A long time. Pole flip or no, these have been good years for us mammals. We’re slightly overdue for the next reversal as far as long-term averages go, but we stand nowhere near the fifty-million-year duration record. And when the flipover process starts, it could last for a thousand centuries.

Has it indeed started? One strange fact is that our global magnetic field has become 10 percent weaker since 1850. And the poles are indeed changing position very quickly. But contrary to the beliefs of those who see meaning—usually grim meaning—in the myriad physical events unfolding around us, no one really knows if these are signs of anything. Maybe Earth’s magnetic strength always fluctuates up and down and this 10 percent business is perfectly normal. And maybe the poles sometimes shift position rapidly, sometimes slowly. There’s no way to know if ours is an unusual period.

Even when it does happen, you’d never be able to tell that you were living in an interchron time of magnetic pole reversal without using measuring equipment. Maybe some pigeons would fly confusedly, but that would be it.

Colonel Norm Couturier, commanding officer of Canadian Forces Northern Area, who is the man charged with protecting Canada’s Arctic sovereignty, was interviewed about the runaway North Magnetic Pole for the Edmonton Journal in 2005.

“It’s a force of nature that we’re not equipped to deal with,” he said jokingly.

Admitting that it would be sad to lose the pole, Couturier pointed out that it also has a bright side: with the pole gone from Canada, Canadians have less responsibility for the ill-prepared adventurers who go on half-crazed skiing adventures to reach the magnetic pole.

“It will probably mean now that we’ll have to stage less rescue missions,” he said. “When it was over in Canadian territory, every year we would have to go and assist somebody or recover somebody that was trying to get there. Now that it’s in international waters, a little bit of the pressure is off us.”

There you have it. The runaway pole is making some people happy.

CHAPTER 4: The Man Who Only Loved Sand

And the Curious Phenomena of the Atacama Desert

You throw the sand against the wind,

And the wind blows it back again.

—WILLIAM BLAKE, “MOCK ON, MOCK ON, VOLTAIRE, ROUSSEAU” (CA. 1800–3)

The Atacama—a region of utter stillness but occasional strange phenomena—is the driest place on earth. Like its host country, Chile, it tirelessly runs from north to south, occupying a vast expanse centered about twenty degrees south of the equator, the latitude that’s home to nearly all major deserts no matter what continent they’re on. Its main geographic oddity is that it’s narrow: the Atacama begins without preamble at the western base of the Andes and stops suddenly after a mere sixty miles, at the cold Pacific.

Having left the Chilean Andes, I had no choice but to drive into the Atacama. I had exercised questionable judgment, however, by impulsively choosing an untraveled sandy trail that headed north and west. It was designated by the thinnest possible line on the map, snaking along for about seventy miles before it reached a seaside fishing village. My gas tank was nearly full, I had a bottle of water, and, well, what else do you need?

Yet after a mere hour of solitary driving among nothing but dunes and small rocks, not encountering a single car passing me going the other way, the initial elation of adventure was replaced by a vague and uncomfortable feeling.

No one was there. The sun was fierce. There was certainly no cell-phone service. What if the car broke down? No one knew my plans. When would another car travel on this dry dirt trail? Would the next vehicle appear any time this month? This year? I glanced at the single plastic liter of water on the seat next to me. It suddenly occurred to me that I was an idiot.

Turn around or keep going? I figured I was roughly at the halfway point. It made no difference now. Anyway, never turn back. At this point, I had no idea that my odyssey would become bound up with that of a legendary British brigadier named Ralph Bagnold.

Suddenly, without preamble, a yellow dust devil appeared perhaps forty yards in front of me, and I slammed on the brakes, creating a competing dust cloud. It was a dead ringer for a tornado, a miniature version. I got out and had to crane my neck to see how very high it towered into the blue cloudless sky. And now it was joined by a twin to my right. Swirling crazily, they both moved ahead at maybe walking speed and showed no sign of dissipating. Each was perhaps six feet thick. In the unchanging sameness of the desert, where everything else was utterly motionless and even the wind was perfectly calm, this sudden lively animation was startling. The fierce whirlwinds were not just surreal. To tell the truth, they were downright spooky.

Unlike tornadoes, dust devils develop from the ground up. They favor dry places, such as deserts, and do not form from clouds. Indeed, like the pair I was now observing, they usually materialize beneath calm, cloudless skies.1

I knew that they could reach above the tallest skyscrapers, but these towered perhaps three hundred feet. Thirty stories.

In the dry, very thin air of Mars, the sudden materialization of dust devils marching across the chocolate-orange soil seems like the work of spirits. In fact, these dust devils are referred to in Arabic as jinni, which means “demon” and which was the origin of our word genie. They abruptly give that lifeless red planet the brash hint that, yes, the hand of nature still stirs even there, where Earth is a mere dot in the sky.

Those bizarre “spirits” may even be benevolent. On March 12, 2005, technicians monitoring the Mars rover Spirit found that a fortunate encounter with a dust devil had blown off the thick dust on its solar panels, which had choked off much of the power supply. Now, suddenly, electricity generation dramatically increased. Expanded science projects were joyously scheduled. Previously, another rover, Opportunity, had also had its solar panels mysteriously cleaned of accumulated dust, and a dust devil was likewise assumed to have been the cause.

I got the sudden urge to step into one. Would it be dangerous? How fast were those winds, exactly?2

I’d heard that dust devils sometimes throw jackrabbits into the air. But the only truly scary story I’d ever encountered was that of three children who sat in an inflatable playhouse just outside El Paso, Texas, in 2010. The trio were taken into the sky, playhouse and all, carried over a fence and three houses, and then deposited on the ground without serious injury.

The impulse was irresistible. It was my investigative duty as a science journalist, I rationalized. I trotted clumsily across the sands toward the nearest dust devil, my feet sinking with each step, but the whirlwind moved away like a mischievous jinni. It kept eluding me, and then the farther one dissipated abruptly, as if in a dream.

When I finally turned back toward where I thought the car and dirt road were, there was no trace of either. They must be hidden in a depression, I thought. With the lone dust devil snaking away, the silence of the harsh, sunlit desert was overwhelming.

I stood, mesmerized by the isolation. I felt quarantined from the human race.

Anyone who has been to a desert knows its hypnotic appeal. In 2006 I had gone to the Sahara to meet the moon’s shadow, but that total solar eclipse wound up as merely the initial enticement for me; the desert’s magic only grew. And much earlier, as a twenty-two-year-old wandering the world with a backpack, I spent a couple of weeks in the great vast desert of southeastern Iran, between Kerman and Zahedan, where the nightly skies are as inky black and star-filled as I imagine they are on the far side of the moon.3 I had also loved the Thar Desert, with its herds of wild camels and friendly people, in the Rajasthan wastelands of western India. Every desert is unique. This one, the Atacama, is special in several ways.

For starters, it’s the driest of them all. In some sections no measurable rain has fallen for the past five years. There is thus not the slightest trace of even scrub vegetation. The cold, rich South Pacific, with its famous Humboldt Current, laps at the desert’s beaches, where penguin colonies nest in its protected bays, while the forbidding peaks of the Andes abruptly define its eastern edge. These mountains are the culprits that manufacture the aridity. The prevailing easterly winds are forced to rise, cool, and dump their moisture on southern Bolivia and northern Argentina. At night, nearly continuous lightning over the Andes hovers above the unseen border between the two countries. When the air descends from the Andes it is bone dry.

Lack of rainfall and vegetation are the calling cards of most deserts, but they also hold one other feature in common: the classic stage set of blue sky and fierce sun. With no trees to cast shadows, the Atacama offers no relief.

Standing amid a 360-degree panorama of stark, sandy, sunlit isolation, I realized I’d overlooked the most central “action figure” of all, the one whose natural motion rules everything else. The sun.

The author appears lost in the desert. On all the world’s ergs, sand moves in a precise, mathematical way.

For most of us, it is sometimes factored into our plans: Should we cancel our beach trip if it’s cloudy? But it’s relatively rare for the sun to modify our behavior in modern times. We mostly ignore it. Even science nerds are only vaguely aware of its various cycles and quirks.

But here in the desert there is nothing else. The sun calls all the shots. And if you’re stuck without a means of exit, it ultimately decides whether you live or die.

Its most basic animation is the day-night rhythm. This remains steady throughout our lives but is much less uniform over the lifetime of our world. When the first dinosaurs walked through the Meadowlands of New Jersey—then part of the supercontinent Pangaea—the year had four hundred days.

Not impressed? Then look back further, to when life first appeared. Earth spun much faster then. The environment was truly alien, unrecognizable as the precursor to today’s world. The air had no oxygen. The sun was 30 percent dimmer and daily crossed from horizon to horizon in five hours. It visibly moved. Shadows perceptibly shifted, as they do in time-lapse nature photography.

As the sun spins once a month, its surface pulses up and down like that of a subwoofer. (Matt Francis)

The moon’s tidal tug creates an oceanic bulge beneath it and a second bulge on the exact opposite side of Earth. These bulges travel around as our planet spins, exerting a bit of torque as countless tons of seawater smash into coastlines to deliver the “High tide!” news to bathers and gulls. Continuously lengthening our days by slowing our spin, the moon’s tides make the sun move ever more sluggishly across the sky.

We’re reminded of this every year or two when scientists announce the insertion of a “leap second” into the final minute of June or December. Television stations give this job to their meteorologists, who explain that extra seconds are needed because our planet is winding down and will ultimately make each rotation, each of our days, forty days long in the far future.

But if you’re a serious card-carrying geek you’ve surely stopped in your tracks, grabbed your calculator, and said to everyone within earshot, “Wait a minute! They add a second every year or two? Earth can’t be slowing that quickly. It just can’t!” You go tap-tap-tap on the instrument’s keys and realize that if our planet’s day was really growing a second longer every couple of years, we’d have come to a frozen halt billions of years ago. Something doesn’t add up. Something about the rotation of our world simply doesn’t make sense.

Because the media always get this wrong, here’s the real scoop. The answer involves beauty. Poetry, even. After all, a watch set to the right time is a device synchronized with Earth’s rotation. It lets Orion and the Dog Star march to the beat of the timepieces on our wrists or, more likely these days, the überprecise digital time on our smartphones, whose signals are periodically synchronized with atomic clocks even if we don’t care about such accuracy.

In the 1950s an important decision was made, an agreement between every nation on our whirling planet. It was, simply, that Earth’s spin rather than vibrating quartz crystals or any other timekeeping method would dictate the time. This meant we needed two parallel monitoring systems kept in sync with each other. One is our planet’s spin, constantly scrutinized by an agency in France called, not surprisingly, the International Earth Rotation Service.

The other system requires the careful daily marking off of 86,400 seconds, each precisely defined. These official ticktocks are counted by forcing the nucleus of the cesium 133 atom to maintain a particular spin direction, which it does only when bathed in 9,192,631,770 microwave pulses per second. Any other frequency changes the cesium. So an atomic clock is simply a vacuum chamber where a fountain of gaseous cesium atoms are bathed in microwaves and the state of the cesium is continuously monitored. That’s the story. A servomechanism slightly varies the microwave frequency if required. An official second is thus 9,192,631,770 microwaves, just what’s needed to maintain cesium 133 in a fixed condition. That exact number of microwave pulses is the definition of a second.

The official second remains constant. Earth, alas, does not. Along with spin irregularities not fully understood, observations of the stars show that our planet’s day becomes one seven hundredth of a second longer after each century has passed.

This may seem too trifling to matter at all. Compared to the day you were born, the day you start receiving Social Security checks is one thousandth of a second longer. Sure, this adds up, but it’s way too little to require meddling with clocks every year or two. So again, why those leap seconds?