Lab Girl (8 page)

“Where is Armenia? I don't even know,” I asked.

“Most of it isn't anywhere,” he answered. “That's kind of the problem.”

I nodded, sensing the gravity of his words while not really understanding them.

Near the end of the trip, I approached my advisor as he readied the equipment for the next day's work. “Listen, we have to hire that Bill guy in the lab,” I told him.

“You mean the weird dude who's always off by himself?” he asked.

“Yes. He's the smartest one in the class. We need him in the lab.”

My advisor looked back at the tools he was sorting. “Uh-huh. And how do you know that?” he asked me.

“I don't know it,” I said, “but I feel it.”

As usual, my advisor relented. “Okay, go ahead, but you have to do the paperwork. I'm already way too overloaded, so he's your responsibility. You are the one who is going to keep him busy, got it?”

I nodded gratefully. I was newly excited about the future, but I didn't quite know why.

Three days later, when we finally rolled back into town after the trip's end, it was my job to drop the students off, finally bringing them home with their gear. Bill was the last to be delivered, and it was late at night as I pulled up to the BART station that he'd requested.

I mentioned the possibility of a job to him. “Hey, I don't know if you are interested, but I could set it up for you to work in the research laboratory where I work. For money and everything.”

There was no immediate reaction to my statement. He looked down and after a moment he said gravely, “Okay.”

“Okay, then,” I agreed.

Bill continued to sit and stare at his feet while I waited for him to get out of the car and say goodbye. Presently he looked up and then out of the window for several more minutes while I wondered what could be keeping him.

Finally, Bill turned around and spoke to me: “Aren't we going to the lab?” he asked.

“Now? You want to go now?” I smiled at my new friend.

“I've got nowhere else to go,” he said gamely, and then added, “and I've got my own shovel.”

As happens at odd moments, a scene in a book that I had read came back to me and I thought again of Dickens, but this time
Great Expectations.
I thought about Estella and Pip at the end of the story, and about how they stood exhausted but hopeful within a dusty garden, tasked with rebuilding a ruined house. I thought about how even though neither character knew what to do next, they could see no shadow of being parted.

THE FIRST REAL LEAF
is a new idea. As soon as a seed is anchored, its priorities shift and it redirects all its energy toward stretching up. Its reserves have nearly run out and it desperately needs to capture light in order to fuel the process that keeps it alive. As the tiniest plant in the forest, it has to work harder than everything above it, all the while enduring a misery of shade.

Folded within the embryo are the cotyledons: two tiny ready-made leaflets, inflatable for temporary use. They are as small and insufficient as the spare tire that is not intended to take you any farther than the nearest gas station. Once expanded with sap, these barely green cotyledons start up photosynthesis like an old car on a bitter winter morning. Crudely designed, they limp the whole plant along until it can undertake the construction of a true leaf, a
real
leaf. Once the plant is ready for a real leaf, the temporary cotyledons wither and are shed; they look nothing like all the other leaves that the plant will grow from this point forward.

The first real leaf is built using only a vague genetic pattern with nearly endless room for improvisation. Close your eyes and think of the points on a holly leaf, the star of a maple leaf, a heart-shaped ivy leaf, a triangular fern frond, the fingery leaves of a palm. Consider that there can easily be a hundred thousand lobed leaves on a single oak tree and that no two of them are exactly the same; in fact, some are easily twice as big as others. Every oak leaf on Earth is a unique embellishment of a single rough and incomplete blueprint.

The leaves of the world comprise countless billion elaborations of a single, simple machine designed for one job only—a job upon which hinges humankind. Leaves make sugar. Plants are the only things in the universe that can make sugar out of nonliving inorganic matter. All the sugar that you have ever eaten was first made within a leaf. Without a constant supply of glucose to your brain, you will die. Period. Under duress, your liver can make glucose out of protein or fat—but that protein or fat was originally constructed from a plant sugar within some other animal. It's inescapable: at this very moment, within the synapses of your brain, leaves are fueling thoughts of leaves.

A leaf is a platter of pigment strung with vascular lace. Veins bring water from the soil to the leaf, where it is torn apart using light. The energy produced from this tearing apart of water is what glues sugars together after they are fixed from the air. A second set of veins transports the sugary sap out of the leaf, down to the roots, where it is sorted and packaged for either immediate use or longer-term storage.

A leaf grows by enlarging the string of cells located along a central vein; single cells on the perimeter eventually decide independently when to stop dividing. From this tip, smaller veins develop, eventually completing the network at the stem; thus the overall maturation proceeds from tip to base. Once the most daring portion of the leaf is complete, the plant puts horse before cart and begins to slide sugar back down and in, down to where it will be used to make more root, which will be used to bring up more water, which will be used to expand new leaves, which will pull back more sugar, and in this manner four hundred million years have passed.

Every once in a while a plant gets an idea to make a new leaf that changes everything. The spines on a cholla cactus are barbed like a fishhook, sharp and tough enough to puncture the leathery skin of a tortoise. They also reduce airflow across the cactus's surface, thereby reducing evaporation. They provide meager shade for the stem and a surface upon which to condense dew. The spines are actually the leaves of the cactus; the green portion is its swollen stem.

Probably within just the last ten million years, a plant had a new idea, and instead of spreading its leaf out, it shaped it into a spine, such as those we find today on the cholla cactus. It was this new idea that allowed a new kind of plant to grow preposterously large and live long in a dry place where it was also the only green thing around to eat for miles—an absurdly inconceivable success. One new idea allowed the plant to see a new world and draw sweetness out of a whole new sky.

ESTABLISHING YOURSELF
as a scientist takes an awfully long time. The riskiest part is learning what a true scientist is and then taking the first shaky steps down that path, which will become a road, which will become a highway, which will maybe someday lead you home. A true scientist doesn't perform prescribed experiments; she develops her own and thus generates wholly new knowledge. This transition between doing what you're told and telling yourself what to do generally occurs midway through a dissertation. In many ways, it is the most difficult and terrifying thing that a student can do, and being unable or unwilling to do it is much of what weeds people out of Ph.D. programs.

On the day that I became a scientist, I stood in a laboratory and watched the sun come up. I was convinced that I had seen something extraordinary, and I was waiting for the new day to ripen into a reasonable hour at which I could make a telephone call. I wanted to tell someone what I had discovered, though I wasn't quite sure whom to call.

My Ph.D. thesis was built around the tree
Celtis occidentalis,
better known as the hackberry tree, which is found all over North America, common as vanilla ice cream and similarly uninspiring in appearance. Hackberry trees are indigenous to North America and were widely planted in cities in response to one of the innumerable casualties of the European conquest of the New World.

For hundreds of years, beetles—as well as people—have emigrated from Europe to the United States, arriving on ships and docking at ports across New England. In 1928 a hardy group of six-legged insect-pioneers left the Netherlands and homesteaded themselves under the bark of countless
Ulmus
trees. During the process, they also introduced a deadly fungus directly into each tree's bloodstream. The trees responded by shutting down their vascular systems vein by vein to try to limit infection and slowly starved themselves to death while unused nutrients pooled at their roots. Even today, Dutch elm disease continues to ravage the United States and Canada, and tens of thousands of trees succumb each year, pushing the overall death toll well into the millions.

In contrast, not much can kill a hackberry tree, which has been observed to endure both early frost and late drought with nary a loss of leaf. These thirty-foot-tall trees will never grow to be as majestic as their sixty-foot-tall elm predecessors; they ask only a moderate amount from their surroundings and earn our regard in proportion to their humility.

I was interested in
Celtis occidentalis
because of its prodigious fruit that superficially resembles a cranberry. If you pick one up and squeeze it, however, you'll find that the berry is as hard as a rock—mainly because it is a rock: just under its rosy skin is a shell harder than that of an oyster. This rocky structure serves as a mighty fortress for a seed that might have to pass through an animal gut, weather the rain and snow, and do battle with ruthless fungi for years prior to germination. The sediments of many archaeological digs are positively loaded with the stony remains of hackberry pits, as each tree produces millions of seeds during its lifetime. I hoped to develop an analysis of these fossil seed pits that would allow me to guess the average summer temperatures that occurred between the glaciations of the Midwest.

For at least the last four hundred thousand years, glaciers have expanded from the North Pole and then contracted periodically, regular as clockwork. During the short interim periods when the Great Plains have been ice-free, plants and animals migrated, interbred, and tested out new food sources and habitats. But just how hot were these interim summers—were they like the full-on sweltering summers of today, or were they just balmy enough to prevent snow from falling? If you've ever lived in the Midwest, you know that this distinction matters, but imagine how much more it matters to people living close to the land, with animal skins for shelter and a moving target for a food supply.

My thesis advisor and I could imagine all kinds of chemical reactions that would lock in the temperature of formation as each seed pit condensed out of the fruit sap. Our whole theory of temperature-setting-fruit-becoming-fossil was novel and also mysterious enough to keep easy answers out of reach. I devised a set of experiments intended to break the main question down into a series of smaller, discrete tasks. My first task was to figure out exactly how a hackberry seed formed and what it was made of.

To this end, I posted sentry around several living hackberry trees in Minnesota and South Dakota in order to compare cold with (relatively) warm environments. I planned to collect the fruit periodically over the course of a year. Back in the lab in California, I would cut hundreds of these fruits into paper-thin slices, and then describe and photograph them under the microscope.

When I looked through the microscope that magnified it by a factor of 350, the smooth surface of the hackberry pit resembled a honeycomb all stuffed full of something hard and crumbly. Using the concept of a peach pit as a place to start, I soaked several hackberry pits in an acid that I was sure could dissolve at least a bushel of peaches, and then examined what was left. The stuffing had dissolved out from within the honeycomb, leaving its lacy white scaffolding behind. When I placed the wee white structure in a vacuum and heated it to fifteen hundred degrees, carbon dioxide was released, which meant that there was something organic inside the white lattice—yet another puzzling layer.

The tree had grown a seed, spun a stringy net around it, coated the net in some kind of skeleton, and then stuffed the holes full of the same material that makes up a peach pit. By doing so, it protected the seed, giving it a better chance of sprouting and therefore growing into a tree, and perhaps begetting ninety generations of additional trees. If we were going to get any long-term climate data out of these fossil seed pits, this lacy white lattice was clearly a strongbox of information. And once I knew what this most basic part of the seed pit was made of, I'd be on my way.

Just as each type of rock forms differently, they each fall apart differently too. One way to distinguish among the different minerals that are the building blocks of rocks is to smash a sample thoroughly and expose it to x-rays. Each grain of salt in a saltshaker is a perfect cube when viewed up close. Grind one grain into a fine powder and you have shattered it into millions of tiny, perfect cubes. The inescapable cube shape of salt persists because the very atoms that comprise pure salt are bonded together in the shape of a square scaffold that outlines an endless number of cubes. Any break to this structure will occur along the planes of weakness that define these bonds, resulting in more cubes, all repeating the same atomic pattern right down to their smallest components.

Different minerals have different chemical formulas, reflecting differences in the number and type of atoms they contain and the way those atoms are bonded together. Such differences give rise to differences in shape that persist even in powder form. If one can figure out the tiny shapes present in a pinch of mineral powder—even the heterogeneous powder from an ugly, complicated rock—one can also determine its chemical formula.

But how to see the shape of these tiny crystals? After an ocean wave hits a lighthouse, a ripple bounces back across the ocean. The size and shape of this reflective ripple carry information about both the wave and the lighthouse. If we are anchored in a rowboat far away, we can distinguish a lighthouse with a square base from one that is rounded by the way the ripple hits us, provided that we have a very good idea of the size of the wave, its energy and timing, and the direction it has traveled. This is similar to how we work out the tiny shapes within mineral powder, using the ripples that bounce back, or diffract, from very small electromagnetic waves known as x-rays. A piece of film catches the ripples at their peaks, and their spacing and intensity allow us to reconstruct the shape off which they bounced.

In the fall of 1994, I asked permission for access to the x-ray diffraction laboratory that was situated across campus from my usual lab, and I was allotted some hours during which to use the x-ray source. I looked forward to my analyses with the same happy anticipation one brings to a baseball game: anything might happen, but it will probably take a long time.

After much deliberating, I had chosen to reserve the machine at night, but I wasn't sure that I had made the best choice. There was a creepy post-doc who worked in that lab, and I was uncomfortable with his surly demeanor. I'd seen how the slightest look or question could set this guy off on a rage, and he seemed particularly menacing toward the odd female who stumbled into his orbit. Thus I had a dilemma: If I came during the day, I'd be sure to see him, but there would be people around who might serve as human shields. At night, I'd likely have the place to myself, but on the odd chance that he did come in, I'd be an easy mark. In the end I signed up for a midnight shift and brought a three-quarter-inch ratcheting wrench along with me. I wasn't quite sure how I would actually defend myself with the tool if something happened, but just having the weight of it in my back pocket made me feel better.

When I got to the x-ray diffraction laboratory, I placed a glass sample slide onto the countertop, covered it in fixating epoxy, and sprinkled it with powder from the ground hackberry pit. I placed the slide into the diffraction machine and oriented everything carefully, and then activated the x-ray source. After lining up the strip chart, I said a silent prayer that its unobservable inkwell was full enough to last the entirety of the run, and then I settled in to watch and wait.

When a lab experiment just won't work, moving heaven and earth often won't make it work—and, similarly, there are some experiments that you just can't screw up even if you try. The readout from the x-ray displayed one clear, unequivocal peak at exactly the same angle of diffraction each time I replicated the measurement.

The long, low, broad swoop of ink was totally unlike the stiff, jerky spikes that my advisor and I thought we might see, and it clearly indicated that my mineral was an opal. I stood and stared at the readout, knowing that there was no way I had—or anybody could have—possibly misinterpreted the result. It was opal and this was something I knew, something I could draw a circle around and testify to as being true. While looking at the graph, I thought about how I now knew something for certain that only an hour ago had been an absolute unknown, and I slowly began to appreciate how my life had just changed.

I was the only person in an infinite exploding universe who knew that this powder was made of opal. In a wide, wide world, full of unimaginable numbers of people, I was—in addition to being small and insufficient—special. I was not only a quirky bundle of genes, but I was also unique existentially, because of the tiny detail that I knew about Creation, because of what I had seen and then understood. Until I phoned someone, the concrete knowledge that opal was the mineral that fortified each seed on each hackberry tree was mine alone. Whether or not this was something worth knowing seemed another problem for another day. I stood and absorbed this revelation as my life turned a page, and my first scientific discovery shone, as even the cheapest plastic toy does when it is new.

I didn't want to touch anything, because I was just a visitor. So I stood and looked out the window, waiting for the sun to come up, and eventually a few tears ran down my face. I didn't know if I was crying because I was nobody's wife or mother—or because I felt like nobody's daughter—or because of the beauty of that single perfect line on the readout, which I could forever point to as
my
opal.

I had worked and waited for this day. In solving this mystery I had also proved something, at least to myself, and I finally knew what real research would feel like. But as satisfying as it was, it still stands out as one of the loneliest moments of my life. On some deep level, the realization that I could do good science was accompanied by the knowledge that I had formally and terminally missed my chance to become like any of the women that I had ever known.

In the years to come, I would create a new sort of normal for myself within my own laboratory. I would have a brother closer than any of my siblings, someone I could call any hour of the day or night and gossip with more shamelessly than I ever had with my girlfriends. Together, we would devote ourselves to exposing the absurdity of our endeavors and continuously remind each other of particularly ridiculous examples. I would nurture a new generation of students, some of whom were just hungry for attention, and a very few who would live up to the potential that I saw in them. But on that night, I wiped my face with my hands, embarrassed to be weeping over something that most people would see as either trivial or profoundly dull. I stared out the window and saw the first light of the day spilling its glow out upon the campus. I wondered who else in the world was having such an exquisite dawn.

I knew that before noon I would be told that my discovery was not special. An older and wiser scientist would tell me that, in fact, what I had seen was something that he himself might have assumed. While he explained that my observation wasn't a true revelation, only a confirmation of what should have been an obvious guess, I listened politely. It didn't matter what he said. Nothing could alter the overwhelming sweetness of briefly holding a small secret that the universe had earmarked just for me. I knew instinctively that if I was worthy of a small secret, I might someday be worthy of a big one.

By the time that the sunrise had burned through the Bay Area fog, I felt lifted out of my maudlin mood as well. I walked back to the building where I usually worked in order to start my day. The chilly air smelled of eucalyptus in a way that will always remind me of Berkeley, though the campus was quiet as death. I let myself into the lab and was surprised to find that the lights were on. I then saw Bill, who was sitting on an old lawn chair in the middle of the room and staring at a blank wall while listening to the static of talk radio on his little transistor.