Zoom: From Atoms and Galaxies to Blizzards and Bees: How Everything Moves (4 page)

Of course, nobody can maintain that pace for long. The fastest mile, at three minutes and 43.13 seconds, amounts to sixteen miles per hour. And the best a marathoner has achieved is to average 12.5 miles per hour. We consider animals slow or fast based on the ancient important issue of whether they can catch up to us from behind.1

But our exploration at the moment is of the far more prevalent realm of slothfulness. Speaking of which, those three-toed mammals didn’t earn their reputations for nothing. A sloth, even when motivated, only walks at 0.07 miles per hour. “Breeze it, buzz it, easy does it”—as Ice sang in West Side Story; the most excited sloth would need a long summer day to cover a single mile. Even giant sea turtles lope 25 percent faster.

Perceived speed is a tricky business. We regard something as fast only if it moves its own body length in a short time. For example, a sailfish swims ten of its lengths per second and is thus viewed as very swift. But a Boeing 747 airliner approaching for a landing only manages to traverse one of its lengths, 230 feet, in a second. It’s visually penalized by its own enormity. From a distance, a descending jumbo jet seems virtually motionless because it takes an entire second to fully shift its position. Yet it actually moves four times faster than the fish.

Now consider bacteria. Half the known varieties have the ability to propel themselves, usually by whipping their flagella—long helical appendages that look like a tail. Are they slow? In one sense, yes. The fastest bacteria can traverse the thickness of a human hair each second. Should we be impressed?

Zoom in, however, and this motion becomes remarkable. First, that bacterium has moved one hundred times its own body length each second. Some manage two hundred body lengths. Relative to their size, they swim twenty times faster than fish. It’s equivalent to a human sprinter breaking the sound barrier.

Moreover, the covered distance quickly adds up. Germs can transport themselves one or two feet per hour. That’s the speed of a minute hand on a wall clock. No wonder diseases spread.

In our homes, other eerie motion unfolds as well, all the time. Dust in the air, for example, much of which consists of tiny bits of dead skin. Watch a sunbeam cast its rays through a window and your home’s omnipresent suspended dust becomes obvious. After all, light rays are invisible in and of themselves. In our homes we see a beam only when it strikes countless slow-drifting particles. In very humid conditions, minuscule water droplets catch the light. But in dry air it’s always dust.

A quick glance makes it seem as if the suspended particles aren’t going anywhere. They move up or down with the slightest air current. But leave the room alone—at night, for example, when nobody is disturbing anything—and all this dead skin and other detritus settles at the rate of an inch an hour. That’s ten times slower than all those scurrying bacteria. Who suspected that our homes are so creepy?

In the visible realm, the standard archetypes for intimate slow mo are our fingernails. And hair.

Fingernails grow a quarter of an inch longer every two months. That’s half the rate of hair growth. If we neglected our barber appointments the way Newton and Einstein did, we’d find our hair six inches longer each year.

But nails vary in interesting ways. Our longer fingers grow their nails more speedily. Pinkie nails advance sluggishly. Toenails grow at only one-fourth the rate of fingernails. That is, they grow at that rate unless you like to walk barefoot, which stimulates growth. Fingernails respond to stimulation, too. That’s why typists and computer addicts enjoy the fastest-growing nails of anyone. Maybe this explains why so many of us writers like to bite them.

Nails grow faster in summer, faster in males, faster in nonsmokers, and faster in pregnancy. But nails do not grow at all after you’re dead. That macabre myth probably started because the skin on dead fingers pulls back, exposing more nail within two days after a person has passed away.

Probably the most dramatic example of slow motion on earth is the earth itself. In caverns, stalactites and stalagmites typically extend at the rate of one inch every five hundred years. By comparison, mountains are downright speedy; they push themselves higher—in the case of the Himalayas, anyway—by a couple of inches a year.2

Stalactites are mirrored in this reflective pool in Luray Caverns, located in Virginia’s Shenandoah Valley. It typically takes five hundred years for each of these downward-pointing structures to grow one inch.

A 2006 study showed that mountain ranges typically rise to their full height in only about two million years. Mount Everest has grown measurably taller since it was first scaled. Some activities just keep getting harder.

Actually, you yourself are moving even when you’re doing the couch-potato thing. All landmasses are shifting, carrying you and your TV toward the west if you live in the United States. You can lie in bed and sing, “California, here I come!” But at half an inch a year, you’d better bring your own trail mix.

This tectonic drift was first discovered by Abraham Ortelius, a well-regarded Flemish mapmaker, in the late sixteenth century. He wrote, “The Americas were torn away from Europe and Africa… by earthquakes and floods” and went on to note that “the vestiges of the rupture reveal themselves if someone brings forward a map of the world and considers carefully the coasts of the three [continents].”

Independently, Alexander von Humboldt, in the mid-nineteenth century, while mapping the eastern coast of South America, wrote that its emerging outline seemed like the adjoining jigsaw-puzzle piece for the western side of Africa. The only logical conclusion was that continents shift. But neither of these men was credited with this astonishing revelation. Nor did any other scientists take the idea and run with it. It wasn’t until Alfred Wegener’s 1912 theory of continental drift that people started taking it seriously, even if there remained more critics of it than believers for the next half century.

Here was a case where you had an effect—landmass motion—before you had any conceivable cause. Yet it always stared us in the face. What’s below Earth’s surface? Lava, obviously—what we now call magma. This is a liquid. Suddenly it seemed plausible that continents float on this thick, dense fluid. And if they float, they obviously could shift. The problem was coming up with a mechanism or force that could propel them sideways. Ever try pushing a stalled car? Imagine the torque required to budge an item like Asia. Continents are not pond scum.

That’s why the idea of drifting continents was not widely accepted among the top geologists. It was, in fact, ridiculed for decades. No proposed mechanism that seemed truly plausible came forth, at least none in which the math would work. It took until the 1950s and particularly the 1960s before the true reason for landmass motion finally came to light. The cause had been hidden beneath thousands of feet of murky brine.

It was the dramatic but unknown reality of the sea floor spreading apart. Mid-ocean volcanic activity creates widening fissures and forces a growing separation between the floating continents. The greatest fault line, the Mid-Atlantic Ridge, is the primary point of separation for the earth’s crust. New techniques of seismology and, finally, GPS tracking sealed the deal.

Nowadays we know of eight separate floating landmasses, each chugging along in various directions. The Hawaiian chain is the fastest moving, as it heads to the northwest at the rate of four inches annually. We can now also easily match geologic features on one continent’s edge with those on another’s, proving they were connected in the not-so-distant past. For example, eastern South America and western Africa not only share specific unique rock formations but also contain matching fossils and even living animals found nowhere else. Similarly, the Appalachians and Canada’s Laurentian Mountains are a perfect continuous match with rock structures in Ireland and Britain. All the evidence proves that the separate continents were once a single supercontinent—the famous Pangaea. It formed three hundred million years ago and started breaking apart one hundred million years later.

Before Pangaea there were long periods of multiple drifting continents separated by several oceans alternating with periods in which single, unbroken supercontinents were surrounded by water, which encircled the entire planet. The monolithic supercontinents that preceded Pangaea have names like Ur, Nena, Columbia, and Rodinia. We humans got to see none of it. Even the Rodinians, 1.1 billion years ago, never strutted around with proud Rs on their sweatshirts. They were microscopic creatures who lived exclusively in the sea.

So in continental drift we have something continuous and certain that vastly changes the appearance of Earth over tens of millions of years. Here is slow, epic, ceaseless movement—unseen and unfelt. And suspected by not a single pre-Renaissance genius.

In our human obsession with measuring and categorizing things, we find one very obvious end point when it comes to speed: The bottommost terminal. Nothing can travel slower than “stopped.” Yet it’s surprisingly hard to find anything that exhibits no motion on any level.

If we look closely, even a sleeping sloth stirs. It’s breathing, and its atoms jiggle furiously. But it’s especially cool to note that the colder something is, the slower its atoms move, so true motionlessness means reaching a state of infinite cold.

At the chilliest place on earth (the Antarctic, where a frosty negative 129 degrees Fahrenheit was registered in 1983) there’s still plenty of atomic motion. Atoms stop moving only at 459.67 degrees Fahrenheit below zero. That’s absolute zero. It was first recognized by the brilliant if cantankerous Lord Kelvin in the mid-nineteenth century; his posthumous reward was the increasingly utilized Kelvin temperature scale, which places its zero at that momentous point (rather than at water’s freezing point, as Anders Celsius did, or at the temperature of an icy brine slush, which is where Daniel Fahrenheit chose to position his scale’s starting position).

Until the mid-1960s, astronomers thought that if thermometers were positioned far from any stars, they would register absolute zero throughout the universe. Now we know that the heat of the big bang produces a five-degree warmth that fills nearly every cosmic crevice. It’s usually expressed as 2.73 degrees on the Kelvin scale. (And the universe keeps getting colder all the time, chilled by its expansion like a discharging aerosol can of whipped cream: it was twice as warm eight billion years ago.)

The universe’s coldest known place, its ultimate Minnesota, is right here on earth, in research laboratories where temperatures less than a billionth of a degree above absolute zero were first created in 1995. This technological deep freeze yields an Alice in Wonderland of bizarre conditions. When atomic motion stops, matter loses all resistance to electrical current, creating superconductivity. Strange magnetic properties also arise (the Meissner effect), making magnets levitate like magician’s assistants. Then there’s superfluidity, in which liquid helium defies gravity and flows up the sides of its container, escaping like some resourceful mouse by simply scampering up and out. Finally, a new state of matter materializes as any substance approaches absolute zero. Neither solid, liquid, gas, or plasma, it’s called the Bose-Einstein condensate. Shoot light into it and the photons of light themselves come to a virtual halt.3

But any exploration of nature’s slowest entities would be incomplete without an examination of the single substance most associated with lethargy. We’re talking about molasses. Slow as molasses.

Being scrupulously scientific, our quest was to find any actual measurement and qualification of molasses’s exact viscosity (gooeyness). Unearthing this information wasn’t easy. One paper from 2004, in the Journal of Food Engineering, had this soporific abstract:

The rheological properties of molasses with or without added ethanol were studied using a rotational viscometer at several temperatures (45–60°C), different amounts of added ethanol in molasses-ethanol mixture per 100 g of molasses (1–5%) and rotational speed ranging from 4.8 to 60 rpm. Flow behaviour index of less than one confirmed pseudoplasticity (n = 0.756–0.970)…

And on it went until the punch line was reached at last:

The suitability of the models relating the apparent viscosity were judged by using various statistical parameters such as the mean percentage error, the mean bias error, the root mean square error, the modeling efficiency and chi-square (χ2).

Okay, so how viscous or slow is molasses? And what is it, anyway?

Molasses actually has three forms, all of which result from sugar refining. Essentially you crush sugarcane and then boil the juice, extract and dry the sucrose, and the leftover liquid is molasses. The initial fluid remnants are called first molasses. If you then reboil it to extract more sugar you get second molasses, which has a very slightly bitter taste, and I hope you’re taking notes on all this. A third boiling of the syrup creates blackstrap molasses, a term coined around 1920. Since most of the sugar from the original sugarcane liquid has now been removed, the blackstrap molasses is a low-calorie product, thanks to its skimpy remaining glucose content. The happy news is that it contains the good stuff never removed in the processing, including several vitamins and major amounts of minerals such as iron and magnesium. But we don’t really care about all this. What matters is how slow it is.

Viscosity is a liquid’s or gas’s thickness. Its degree of internal friction. The less viscous a fluid is, the greater its ease of movement. A viscous fluid will not just “run” more slowly, it will also exhibit a dramatically smaller splash when poured.

Naturally, we often use water’s viscosity as a comparison. If water is rated at just below 1 on the scientific viscosity rating scale, then blood officially rates a 3.4. So blood really is thicker than water.

Sulfuric acid has a viscosity of 24. Did you know that that scary acid is so syrupy? Thinnish winter-use motor oil with an SAE 10 rating has a viscosity of 65. In contrast, the thick motor oil used in hot regions, SAE 40, has a very high viscosity of 319. This is stereotypical guy stuff.