The Best American Science and Nature Writing 2011 (32 page)

The idea of alternative realities is a mainstay of today's popular culture. For example, in the science-fiction film
The Matrix
the human race is unknowingly living in a simulated virtual reality created by intelligent computers to keep them pacified and content while the computers suck their bioelectrical energy (whatever that is). How do we know we are not just computer-generated characters living in a Matrix-like world? If we lived in a synthetic, imaginary world, events would not necessarily have any logic or consistency or obey any laws. The aliens in control might find it more interesting or amusing to see our reactions, for example, if everyone in the world suddenly decided that chocolate was repulsive or that war was not an option, but that has never happened. If the aliens did enforce consistent laws, we would have no way to tell that another reality stood behind the simulated one. It is easy to call the world the aliens live in the "real" one and the computer-generated world a false one. But if—like us—the beings in the simulated world could not gaze into their universe from the outside, they would have no reason to doubt their own pictures of reality.

The goldfish are in a similar situation. Their view is not the same as ours from outside their curved bowl, but they could still formulate scientific laws governing the motion of the objects they observe on the outside. For instance, because light bends as it travels from air to water, a freely moving object that we would observe to move in a straight line would be observed by the goldfish to move along a curved path. The goldfish could formulate scientific laws from their distorted frame of reference that would always hold true and that would enable them to make predictions about the future motion of objects outside the bowl. Their laws would be more complicated than the laws in our frame, but simplicity is a matter of taste. If the goldfish formulated such a theory, we would have to admit the goldfish's view
as
a valid picture of reality.

A famous real-world example of different pictures of reality is the contrast between Ptolemy's Earth-centered model of the cosmos and Copernicus's sun-centered model. Although it is not uncommon for people to say that Copernicus proved Ptolemy wrong, that is not true. As in the case of our view versus that of the goldfish, one can use either picture as a model of the universe, because we can explain our observations of the heavens by assuming either Earth or the sun to be at rest. Despite its role in philosophical debates over the nature of our universe, the real advantage of the Copernican system is that the equations of motion are much simpler in the frame of reference in which the sun is at rest.

Model-dependent realism applies not only to scientific models but also to the conscious and subconscious mental models we all create to interpret and understand the everyday world. For example, the human brain processes crude data from the optic nerve, combining input from both eyes, enhancing the resolution, and filling in gaps such as the one in the retina's blind spot. Moreover, it creates the impression of three-dimensional space from the retina's two-dimensional data. When you see a chair, you have merely used the light scattered by the chair to build a mental image or model of the chair. The brain is so good at model-building that if people are fitted with glasses that turn the images in their eyes upside down, their brains change the model so that they again see things the right way up—hopefully before they try to sit down.

In the quest to discover the ultimate laws of physics, no approach has raised higher hopes—or more controversy—than string theory. String theory was first proposed in the 1970s as an attempt to unify all the forces of nature into one coherent framework and, in particular, to bring the force of gravity into the domain of quantum physics. By the early 1990s, however, physicists discovered that string theory suffers from an awkward issue: there are five different string theories. For those advocating that string theory was the unique theory of everything, this was quite an embarrassment. In the mid-1990s researchers started discovering that these different theories—and yet another theory called supergravity—actually describe the same phenomena, giving them some hope that they would amount eventually to a unified theory. The theories are indeed related by what physicists call dualities, which are like mathematical dictionaries for translating concepts back and forth. But, alas, each theory is a good description of phenomena only under a certain range of conditions—for example, at low energies. None can describe every aspect of the universe.

String theorists are now convinced that the five different string theories are just different approximations to a more fundamental theory called M-theory. (No one seems to know what the "M" stands for. It may be "master," "miracle," or "mystery," or all three.) People are still trying to decipher the nature of M-theory, but it seems that the traditional expectation of a single theory of nature may be untenable and that to describe the universe we must employ different theories in different situations. Thus, M-theory is not a theory in the usual sense but a network of theories. It is a bit like a map. To faithfully represent the entire Earth on a flat surface, one has to use a collection of maps, each of which covers a limited region. The maps overlap one another, and where they do, they show the same landscape. Similarly, the different theories in the M-theory family may look very different, but they can all be regarded as versions of the same underlying theory, and they all predict the same phenomena where they overlap, but none works well in all situations.

Whenever we develop a model of the world and find it to be successful, we tend to attribute to the model the quality of reality or absolute truth. But M-theory, like the goldfish example, shows that the same physical situation can be modeled in different ways, each employing different fundamental elements and concepts. It might be that to describe the universe we have to employ different theories in different situations. Each theory may have its own version of reality, but according to model-dependent realism, that diversity is acceptable, and none of the versions can be said to be more real than any other. It is not the physicist's traditional expectation for a theory of nature, nor does it correspond to our everyday idea of reality. But it might be the way of the universe.

FROM
Orion

I
N THE DEAD
of night the human brain is most capable of distillation—of boiling things down to basic black and white.
Smoke means fire. Breaking glass signals intrusion.
From an evolutionary standpoint, this kind of rudimentary thought process might be a most valuable survival skill—the kind that allows a body to respond to threats even in a state of half-sleep. My husband, Herb, is a lawyer, the kind of man who has been trained to think before he acts— to examine all angles and consider complexities. But at three
A.M.
on an uncharacteristically cold and moonless night in late spring, even he is reduced. And through that reduction, he would come to see how things that lurk too starkly, even at opposing ends of the spectrum, can shift. As if fundamentals could be that supple. As if values—like the presence of all colors in relation to the sheer absence of them—could be so pliant. As if the natural order of things—like the age-old relationship between predator and prey— could flex into a new arrangement altogether.

The dogs would start it. Their frenzied barks, their teeth gnashing against the glass of the back door, would draw my husband out of bed and into his jeans in a single motion. In the mudroom he would stumble through a sea of writhing canines, pull on his boots with one hand and turn the knob with the other. Two aging Aussies and a half-blind border collie mix would spill out into the dark yard and charge toward the goat pen. They would make it halfway before stopping dead in their tracks and high-tailing it back to the porch. Herb would hear the screams then, the desperate cries for help. He would fumble in the doorway for the porch light, two-stepping with the returning dogs, and there his sleep-riddled mind would already be drawing conclusions so swiftly it would feel, he would say later, like pure instinct.

And here I should point out that my husband, despite his profession, is a man who could have been born into the Paleolithic—the kind of guy who has built a life sustained by wildness more than any other element. After college Herb left Michigan for the West and never looked back. On the other side of the Continental Divide he found the kind of unfettered topography that he needed—for he's a man who is happiest when ambling over great stretches of soil or stone. He loves the basics, the way they ignite his senses: The procurement of food, shelter, warmth. The silky curves of women, skylines, rivers. Then there is his deeply held belief that he is a sort of Dr. Dolittle, and indeed, I have been witness to his extraordinary ability to communicate with animals. Domestic or untamed, creatures of all sorts seem to enter quickly into some kind of understanding with him.

It is this latter quality that explains why my husband's guns have never been loaded—despite the fact that we have made our home in one of the more wild parts of the West, where black bears, mountain lions, bobcats, and elk are as common as livestock. Where large tracts of untrammeled public land still eclipse both alfalfa fields and subdivisions of "ranchettes." Herb had stored in various places a .22 Smith & Wesson six-shooter, a 12-gauge shotgun, and three rifles in .22, .30-06, and 7mm magnum calibers—an inheritance from his grandfather, who had been an avid hunter in both the Great Lakes region and in Africa. All but the .22s had lain in their cases since his grandfather had died nearly eleven years prior—and those two firearms had only been used to shoot beer cans off fence posts on the occasional Sunday afternoon. Looking back, I think we both took a certain pride—and a smug one at that—in having no need for guns in what is largely a gun-toting community of roughneck ranchers, folks who let loose bullets daily on coyotes and prairie dogs.

So it is mind-boggling that Herb would conclude as he did on that night. Call it a natural impulse, or call it one of the ill effects of living in a culture steeped in sensational news and violent movies, but his mind instantly crafted the assumption that the hair-raising cries coming across the dark yard were of human origin. Somehow, he decided—in our critter-laden outback of a neighborhood that sits seven miles from a tiny, low-crime kind of town—that some heinous, unspeakable assault was being committed by one deranged human upon another. And as he charged away from the now-cowed dogs into the colorless void that lay beyond the porch light's glare, his brain illuminated with one white, shining thought:
This is what the world has come to.
Standing empty-handed in the inkwell of night, he was ready to face squarely some malevolence in his own species.

Herb turned, detouring away from the pen and into an adjoining shed, where he flipped on the light and took quick inventory of several of his grandfather's firearms. He then knelt to rummage for ammunition in a random collection of boxes. This took some doing—my husband is not the most organized of men. And in the process he failed to hear the intruder climb back over the imposingly tall fence that contained the goats and circle around the shed. It was only as he realized that the cartridges that matched these particular firearms were elsewhere that he heard the padding approach behind him. He stood and turned. On the threshold, only four feet away, stood a three-hundred-pound black bear.

Our daughter, Ruby, and I were not there that night—and in hindsight, as well as in the spirit of thinking so fundamentally about things, I can't decide if that was a good or a bad thing. Would our presence have changed in any way Herb's course of action, or the bear's? Would the dogs have been more aggressive? And what might I have done to alter the outcome? Through countless replays of the situation, Herb and I would be reminded that variables come in many hues, and each one has the potential to change the overall effect—the way Warhol's varied silk-screens of Marilyn Monroe changed the essence of the subject simply by changing the colors. Of course we also have to consider that we can only see things through the lens we were born peering into—while other species are able to perceive things entirely invisible to the human eye.

The bear stalled on the threshold for a moment, and my husband stalled briefly too, before realizing he could not possibly summon a single word of conversation with what stood before him. For the first time in his life, Herb was tongue-tied. When he finally spoke (
Yo, dude,
unbelievably), the bear fixed his gaze on him and took a step forward. Fortunately, Herb had been training to bench-press 315 pounds in honor of his fortieth birthday, and so, rather than continuing the conversation, he lunged at the half-open door and heaved his body against it—effectively shoving the bear back outside. The bear stood there for a few minutes, then shuffled across the driveway and into the woods.

Not man, but beast. Of course.
Herb's mind quickly reconfigured to what should have been his first impression all along: big animal with teeth and claws has found easy food in what had been a rather unforgiving emergence from the winter den—the late frosts having nipped springtime staples such as young forbs and grasses. Meanwhile, our daughter's pet goat, a white, bottle-fed Nubian named Dora the Explorer, was still screaming. And at last Herb recognized the wails as hers.

Curiously, the dogs remained on the porch, not uttering a sound. When Herb exited the shed and headed for the house, he made note of the quiet, for three dogs barking in unison has always been enough to keep wild animals at bay. He hadn't even made it ten feet from the shed when the bear reemerged from the woods. Herb scrambled back inside and waited. When he opened the door a second time, the bear stepped out again and came right at him. The two repeated this pas de deux over the course of an hour. It was sometime during those sixty minutes that the goat ceased her cries.