Put Together with a Difference

“We are the representatives of the cosmos; we are an example of what hydrogen atoms can do, given 15 billion years of cosmic evolution.” – Carl Sagan

The eye gave Charles Darwin a “cold shudder”—not because of what could go wrong with it, but because of what had gone right. Second in complexity only to the brain, the eye is made up of more than 2 million working parts. Through millions of years of natural selection, the eye managed to evolve from a simple, light-sensitive skin patch to an intricate, organic camera able to detect a single photon and focus on objects as close as 7 centimeters as well as infinitely far. Ninety-six percent of animal species have eyes, some with capabilities almost beyond belief. Hawks and buzzards can home in on tiny rodents from 10-15,000 feet above the earth. Owls can locate a mouse on a football field at night. Humans, who hardly have the best eyes in the animal kingdom, can see a candle flickering from two miles distant, a star glowing millions of light-years away.

When I was young, I could see the colors of stars: yellow, white, pink, blue. My parents dismissed this when I commented on it, saying they were all white. It wasn’t until I took a basic level astronomy class in college that I learned stars did have different colors, based on their temperatures, and that on a dark night with good eyesight you can detect these colors. Aldebaran, part of the constellation Taurus, glows red, due to its low surface temperature as an older star. The Pleiades—the Seven Sisters—a small cluster of young, very hot stars, glow bluish. Our sun, a medium-sized, middle-aged star, glows yellow.

My son, at age two, suddenly noticed the stars through the mesh roof of the tent on our first camping trip. “I will grab them!” he said and thrust his hands repeatedly skyward. The stars, to him, did not look far, just small, as catchable as lightning bugs. Now very nearsighted, I envied not only his sharpness of vision, but also his undeveloped perspective, his ignorance of distance, of size, of temperature--of the nature of almost everything. That night under the stars, bouncing around on the air mattress in the tent unable to sleep, my son was like the archetypal jester pointing out the truth to the king: our eyesight is illusory; our brains construct the world we see, rather than see the world as it is. This usually helps us efficiently navigate our environment. But the truth is that we are a touchable cosmos; the stars are within us. 

* * *

The day my son was born, I sat in the woods with a snail on my leg. I focused, alternately, on the foreground snail and a background lake, unconsciously ignoring my own nose and the blood vessels on the surface of my retina, which would otherwise obscure the scene. The eye produces images of both the nose and the blood vessels, but the images remain fixed, and the brain gradually stops noticing any image on the retina which does not move. In order to see the outside world, we must ignore, at least in part, our physical selves. 

The reason I could see the nonmoving lake—in fact, as with most folks, the lake’s meditative stillness was my whole aim in being there—was my own involuntary movement. The eyes jiggle imperceptibly, continuously shaking up the visual field, shifting the scene ever so slightly to make its non-moving components appear in different places on the retina. The blood vessels, of course, move with the eye and continue to be ignored. To see what’s not moving in the outside world, we must move (without knowing it!) ourselves. 

On that day, I watched a snail leave a translucent streak on my pants as it journeyed over the hump of my knee, and I also watched the sun-glared surface of the lake, a few feet of water in a deep, convex basin—a kettle depression left by a glacier that receded 10,000 years ago. Had someone been present on its opposite side, I would not have been visible to them, perched on a small rock surrounded by understory in a clearing only big enough for my dog and me. Except for my dog, I was alone, a couple miles in on the New Hope segment of Wisconsin’s Ice Age Trail. I had gone off the trail, then down a steep bank to see what I could see. And I was about to become a mother. 

* * *

Early in a fetus’s development, at about day 21, the forebrain bulges out in two places which will become, by day 70, the fetus’s eyes. Our brains, according to science writer Michael Shermer, are “belief engines—evolved pattern-recognition machines that connect the dots and create meaning.” True to form, our eyes, as part of the brain, do exactly that. Vision is not only what we see, but what gets transmitted to the brain and how the brain interprets it. 

Perhaps the clearest and most well-known example of how the brain creates what we see is the blind spot of vertebrates. Cover your right eye and stare at the red circle below. Then, slowly move your head closer to the circle and when you reach your blind spot, the blue bar will look continuous!  

Here’s what happens: the point on the retina where the optic nerve carries impulses to the brain lacks photoreceptors, cells which take in light from the external world to create an image. This spot does not detect any light coming to it from an area about the size of a golf ball at a distance of approximately one yard, or the size of a person’s head a bit farther. For the most part, the two eyes cancel out each other’s blind spot. When using only one eye, the same constant jiggling that helps to omit the obstruction of the blood vessels helps eliminate the blind spot. Should both of these methods fail, the brain kicks in. It fills in the blind spot, unconsciously, with whatever background material it perceives.

Your brain is expert at filling in what’s missing. In most cases, this failsafe method works to produce an image congruent with the actual scene. Our brain’s ability to fill in is so proficient, people experiencing macular degeneration often do not notice their failing eyesight. Their eyes and brain cooperate to create correct images of the world. But this adaptive trick also makes it possible to see something that is not there and miss something that is. The eyes, which are essentially part of the brain, do just as Shermer argued. Our eyes create the world we see, rather than faithfully report what is. 

Importantly, this filling in happens very early in visual processing; it is actually thought to occur in the cells surrounding the blind spot. It is not an act of assumption, conscious or unconscious, like the act my husband and I would perform in a Milwaukee hospital the day after I sat by the lake with the snail on my leg. You see, I was not pregnant that day in the woods. Another woman was. When the baby arrived she and the baby’s biological father would request adoption, look through the binder of photos our agency gave them, and choose us to be his parents. 

When we laid joyful eyes on that baby, easily we ignored what was missing—shared blood, shared genes—and absolutely saw our son. 

* * *

Developed vision, as evidenced, for example, by the way we ignore the eyes’ blood vessels and fill in the blind spot, can be thought of as a series of shortcuts—shortcuts that show us what we really need to see to survive. It would be very non-adaptive to always be peering through one’s own blood vessels to determine from what angle that grizzly bear was coming at you. But wouldn’t it also be edifying to be reminded of the body’s systems more regularly--of our veins and the blood running through them and all the components of that vital fluid that keeps us ticking? As livable as they make our environment, these visual shortcuts also deprive us of important facts about what the world and we, ourselves, really are.

That first winter, with my son strapped onto my belly, I snowshoed to the lake I had visited the day before his birth. Thoreau calls a lake the earth’s eye, “looking into which, the beholder measures the depth of his own nature” and I wanted my son, as early as possible, to capture this perspective. I sat him down on the frozen surface next to a muskrat lodge. Snow had melted on the lodge, revealing dark, irregularly shaped patches of mud and cattails. Cattails surrounded the lodge, too, their flat blades bent and broken, many half their original size, without their fluffy, hot-dog-shaped flower-heads. Their purple-gray shadows segmented the frozen lake, along with the tracks of white-tailed deer and all manner of non-hibernating winter animals. My dog, coal-black from head to toe, pranced to and fro, circling back, sniffing each track. Young oaks on the lowest part of the bank retained their brown, brittle leaves, along with the brushy shore plants, and the tall conifers farther up the bank held their muted, winter-green needles. In the picture I have of this moment, my son is smiling, and I like to think it is because, at five months, the scene before him was starting to take shape.

Just a short while ago, the frozen lake crisscrossed by our frolicking dog would have looked to him like an ever-changing flat surface where unconnected black shapes appeared and disappeared. Similar items, like the oak leaves, would not have been grouped together as a category of something; the cattails no more or less an entity than their shadows; the tracks pattern-less; each conifer needle separate from its tree and distinct from any other. Newborns see the world in fragments, piecemeal, unaware of what goes with what, what is in front of what, what is near and what is far. They lack object recognition. Imagine this for a moment: your beloved pet as simply photons in motion rather than the sum of affection and quirks by which you characterize her. A world without living beings. A world without things. A world with only face value.

In adults, several dozen areas of the brain work together simultaneously, using clues about color, texture, size, and shape, to produce a sense of unity for each object in a scene. Only after months of continuous experience of the world do infants acquire the shortcuts needed for interpreting visual data: nearer objects look smaller than farther objects, for instance; or, an object that appears to be missing a piece is likely behind another object. Only after hours and hours of visual input can infants create a sensible world.

It’s difficult to attempt to describe how my son must have seen the world on our hikes before object recognition because once the brain develops the ability to use the shortcuts, the inferences we draw from visual data become unconscious. Viewing the Wexler cube at left allows us to feel our brain translating visual data—creating a 3-D object out of a 2-D drawing—as the yellow square switches from foreground to background. In a similar way, I can remember struggling to interpret pictures in the children’s books my mother read to me, the same ones I now read to my son: what I thought was an out-of-place ladder in the children’s bedroom in This is Our House now connects clearly to the flat square below it, the two pieces really a chair; what I saw as a strange pink sausage on top of a white rectangle in Hansel and Gretel now plainly protrudes from a sleeve of Gretel’s dress as her forearm. My own son exhibited his lack of visual shortcuts recently—specifically perspective—laughing hilariously and exclaiming, “That puppy is huge!” at one of the pictures in a book that depicts five same-sized puppies lined up diagonally across a room. I tried to explain to him that the huge puppy was simply closer, causing it to appear larger, but this hasn’t sunk in; each time I turn to that page my son giggles hilariously and makes the same exclamation. 

Once we acquire the shortcuts, however, we do so at the risk of not seeing what is actually there, or seeing something that is not there—as happens with our compensation for the blind spot. The optical illusion at right, called the Kanisza Triangle, illustrates this. We don’t often encounter shapes with pieces taken out (like the black Pac-mans) so the brain assumes that a white triangle is lying on top of three complete black circles. But the triangle does not exist. Think about that for a moment. You see a triangle. But it is not really there. Can you not see the triangle? Force your brain to see what is really before you? It takes a little effort, but you can do it. Focus on one of the absent edges of the triangle. Daydream. Go into yourself. You’ll see just the three Pac-mans.

Recent research suggests a huge leap in how children perceive the world visually between 18 and 24 months. The ability to see the world in objects correlates with a child’s language development, in particular the acquiring of nouns. Thinking about all this seems to explain the furor with which my son explored the world with his other senses in those first two years, touching everything, eating everything, enjoying the loudest of sounds. While I was trying to keep him from being bitten, cut, electrocuted, drowned, poisoned, deafened, he was collecting important data.

I am inclined to think, though, that it may not be learning but unlearning that happens in those first two years. According to Aerts Diederik, a Belgian theoretical physicist, we see the world “as bounded entities occupying space and persisting through time” but “these macroscopic entities are built from microscopic physical entities, described by quantum theory as ‘not at all bounded entities occupying space and persisting in time.’” In other words, the world is composed of atoms, which are composed of protons, neutrons and electrons—whose exact position is impossible to locate—and mostly empty space. We see the world, including ourselves, as complete entities, but we are not. Maybe my son’s infantile view of the world on that early trip to the lake--dog-less, tree-less, just un-compartmentalized, shifting shapes—represents our vision at its most accurate.

* * *

My son was three when the subject of death first came up. The dog bit someone (not the first time) and, with great sorrow, we euthanized her. We simply told him Betsy passed away because she was old (she was) and dogs don’t live that long. We put her body in the ground when he was not looking, covered it with soil, and then sprinkled in a few dog treats and planted a tree above her. 

One day, reminiscing, I mentioned to him that I missed the dog. 

“But you still have me!” he said. 

“Yes!” I responded. There was a pause.

“Maybe I will die soon,” he countered, not as a question, but rather matter-of-factly. 

“No,” I replied, carefully. “Humans live much longer than dogs.” This is not untrue. Neither was my son’s statement, though it is technically unlikely. The U.S. Center for Disease Control actually calculates your probability of dying, based on your age, gender, and race, in its National Vital Statistics Report. I checked the most recent one—2019—and found that my son had a .0001% chance of dying in the next year; my chance was .002%. Not bad numbers. 

But the truth is that we are dying all the time.

Very, very little of our own bodies lives as long as what we consider “we” do—only, in fact, half of the cells in the heart, almost all of the brain, and the lens of the eye. After that, your longer-lasting parts are your skeletal cells (10 years) your muscle cells (15 years) and your fat cells (25 years). Every other tissue in your body is constantly sloughing off dead cells and regenerating throughout your life. In fact, you replace, in cells, nearly your entire body mass every year. You lose about 100 hairs per day but you don’t go bald because each of your hairs is replaced every 2-7 years. Your nail cells replace themselves completely every 6 months; your red blood cells every 4 months. Your entire epidermis—your skin, what holds you in—exposed to cold and wind and heat and sweat and the abrasiveness of clothes and soap replaces itself every 2-3 weeks. The cells that line the villi in your stomach, barraged by strong digestive acids and corrosives with every meal, regenerate every few days. The gastrointestinal tract, from the mouth to the esophagus to the stomach to the small intestine to the large intestine to the rectum and anus, keeps you continuously open to the environment. We think of the human body as a closed container, but really it contains a large amount of surface area on the inside constantly interacting with the outside world. 

“What it comes down to,” write Karel and Iris Schrijver in Living with the Stars, “is that we are intrinsically impermanent, transient, continually rebuilt, and forever changing. We are a pattern, like a cloud, a traffic jam, or a city: even as we exchange our building blocks continually with our surroundings, the overall pattern provides enough stability for us to have a sense of continuity, both with regard to our own body and personality, and with regard to those of others.” A cloud. A traffic jam. A city. The Schrijvers also offer up an ocean wave, a river.

I like this last one best. I grew up on a ridge between the east and west branches of a small river and the favorite pastime of my childhood was to hike down to the valley and wade in the water—sometimes before winter’s ice had melted. That first spring of my son’s life, I could not wait to put his feet in a river. I settled for a small stream—really the outlet of one lake and inlet of another. A river’s composition is constantly changing, the Schrijvers remind us, but we see only the whole, the snake of water which extends from headwaters to basin, not each individual molecule of H20 tumbling along, constantly replaced by a new one. When I stare at the photograph of my ten month old son with his feet in the stream, I try to see both—the stream and my son—as a pattern. I would like to be able to feel the flip of my perception of him from parts to whole as I feel the flip of orientation of the Wexler cube, to see what is really there like I can by altering my focus on the Kanisza Triangle—a feeling of effort just behind the eyes, physical yet not connected to any identifiable part of my body, assisted with a blink, or a glance to the side. Difficult and exhilarating. But try as I might, I cannot.

* * *

Although I cannot properly see my son as a constellation of microscopic particles, my son, even at age four, can recognize a few constellations—in books, that is; early bedtimes thus far have limited his exposure to real stars. His favorites are Cassiopeia, Orion, and the Great Bear.

Cassiopeia. Orion. The Great Bear. We have always, it seems, looked up at the sky and seen living things. Even in that college astronomy class—the one that confirmed my youthful realization of stars’ varying colors—both my textbook and my professor talked about how stars were born, had ages, and died. I understood that stars powered themselves by fusing hydrogen into helium, and then, once their hydrogen had been mostly used up, began creating heavier and heavier elements. Why, then, the curious personification? 

At one point, the textbook actually took a moment to explain this: “Stars are not alive, of course . . . but astronomers nevertheless refer to the changes that stars undergo as stellar evolution . . . the remnants of a dying star shower into space elements vital to human life such as carbon and iron that become incorporated into new stars, planets, and ultimately people. We therefore owe our very existence to stellar evolution.” The passage struck me: it satisfyingly explained what I had thus far failed to understand—exactly what I was.

The human body contains about 7 x 1027 atoms. Approximately 4.2 x 1027 are hydrogen. The other 2.8 x 1027 are carbon, oxygen, nitrogen, phosphorus, and sulphur. We get these atoms, mainly, from what we eat. We consume a plant and take in its sugar, each sugar molecule made of 12 carbon atoms, 22 hydrogen atoms, and 11 oxygen atoms. We burn off some of that matter as energy, but use the rest as building blocks for new cells. We incorporate that plant’s carbon, hydrogen, and oxygen into our very bodies—our bones, our skin, our eyes.

Like “The House that Jack Built,” the story of our physical existence is a cumulative children’s tale, a chain story: This is the carbon in your fingers and toes, that you get from the beans your family grows, that the beans made from air and H2O . . . Plants, of course, make sugar through the process of photosynthesis, represented by the chemical equation 6CO2 + 6H2O → C6H12O6 + 6O2. Using the energy of light captured by their leaves’ chlorophyll, plants combine six carbon dioxide molecules from the air with six water molecules from the soil, resulting in one sugar molecule and six oxygen molecules.

But the chain story doesn’t end there. The soil and air got that same carbon, hydrogen and oxygen from the original cloud of gas and dust that coalesced 4.6 billion years ago to become our planet. (A very small percentage of these atoms could have come from the three pounds of new cosmic dust deposited on Earth each year.) The cloud of gas and dust (and the cosmic dust) got the carbon and oxygen—again, the same atoms—from the supernovae of stars that died sometime in the last 14.6 billion years and the hydrogen from nuclear fusion in the early universe, more precisely from between 3 and 20 minutes after the beginning of time.

This is the star that exploded into you. “You better believe—it’s actually true—that whenever I bleed I think about that,” says Michelle Thaller, astronomer and NASA’s Assistant Director of Science Communication. “The iron that makes my blood red was created the instant a star died.” Carl Sagan said it. Joni Mitchell said it. Ellen Frizell Wyckoff may have been the first to say it in 1913, in the astronomy column in the Greensboro Daily News: 

What was the surprise of the tireless searchers when they found common earth metals burning in the mighty sun! There was once a little girl who cried out with joy when she realized for one little moment that the earth is truly a heavenly body, and that no matter what is happening to us we are really living right up among the stars. The sun is made of star stuff, and the earth is made of the same material, put together with a difference.

The sun and the earth—and we—are made of the same material: stardust. I can understand this when I look at my son. I see the elements that make him up accumulated on his outsides: the food he wears during meals; the half-moons of soil beneath his fingernails; the gravel in his hair; the sand between his toes. After every bath, he leaves a ring around the tub like Saturn’s, his own neck girdled by a more yellow one I can never pinpoint as suntan or dirt. He seems to know exactly what he is—land, world, planet, star—indicated by how he puts almost anything that enters his field of vision in his mouth. The first three years of his life I spent pulling things out of his mouth—once, on the way home from a friend’s, I found in his cheeks simultaneously a marble and a small, plastic gorilla. I constantly worry that he will choke or eat something that will make him sick, or worse. But he is fearless. I can ingest the world, he seems to think, because I am the world.

To say we are stardust is not to say that we are magical or inherently good. Hitler was stardust. Adam Lanza was stardust. Stardust can do terrible things. To put it more objectively, we are constructed of fragments expelled during the explosion of a huge ball of gas once held together by gravity and large enough to produce its own energy. To say we are stardust, to deconstruct the body to its smallest component parts is also not to diminish the astonishing, unique, and fleeting pattern of stuff that is each one of us. It is easy to think fondly of one’s self and one’s loved ones as stardust until one of those loved ones is lost. In death, the temporary pattern that disappears becomes of terrible importance. The parts are nothing. When someone dies, the whole of them that is missing leaves a very definable and palpable hole. When we put our dog to sleep, for weeks I could feel the hole her absent body left in all the corners of the house she used to occupy.

The point, I think, is that we are all stardust. Everything is stardust. To say we are stardust means we are bonded to one another and to the environment in which we live in a very—pun intended—elemental way. There are not strict lines between us. There are not strict lines between us and anything.

* * *

My son’s birthparents are getting married. They invite us to the rehearsal dinner (rather than the wedding) to meet the immediate family, an informal affair outdoors at a cabin on a lake. A situation like this could be awkward, even tense, but I know things will be okay when I see my son’s 6-year-old birth-cousin come walking out of the garage holding a microscope.

It’s just like the one I had growing up and still have in a closet somewhere, only white instead of red. My son grabs the microscope and starts to put the eyepiece in his mouth as if it were a trumpet and he had something to herald. I begin to show him how it works, positioning a pine needle under the clips, but before I can get it to focus he is off to explore something else.

I look up to check where he’s gone. The sun glinting off the lake meets my narrowly focused gaze like a giant, overexposed lens, and my eyes seem to take on the powers of the microscope. What I could not do with the photograph of my son at the muskrat lodge now starts happening. Each person below is a swarm of atoms, a human-shaped web of chemical bonds in constant exchange with its environment. But there is another kind of bonding going on: three nuclear families who mostly haven’t met one another before mill about, making conversation, intermingling while two children and a little dog speed seemingly continuously between and around them like shared electrons. Who knows? An atom that is now in my son’s birthmother’s eye could have formed in the belly of a star right next to an atom that is now in my heart. I think that in fact may be what happened.

I would like to give this concept of identity to my son: that who he is, what we all are, first and foremost, is stardust. The big thing in your life, I want to tell him, is not that your family, an adoptive one, was put together with a difference but that you, we all, in the words of Wkycoff, were put together with a difference. I don’t want him to get caught up in the small stuff—biology, genes—but to take the larger view: we and everything around us are one and the same at the same time that we are different. 

* * *

The eye sits in a bony socket called the orbit, observing the world through the black hole of the iris. “You are not IN the universe, you ARE the universe,” writes spiritual teacher and author Eckhart Tolle, and although it takes some filling in, some conscious work for my brain to see this perspective, I believe it. On that long, sleepless night I endured on my son’s first camping trip, when he tried to grab the stars through the mesh roof of the tent, I said nothing because I wanted him to sleep. But I should have said this: You have the stars in your hands already, for wherever we cast our lines, we catch only ourselves.