by Hope Jahren
But sometimes the difference between an ending and a beginning is blurry. In 1983 researchers at Duke University started yet another forest at the site by planting hundreds upon hundreds of loblolly pine seedlings within the very ashes of their predecessors. The immediate goal was homogeneity: each of the seedlings was exactly three years old, and they all were closely related genetically—the equivalent of half-siblings in human terms. The seedlings were spaced exactly two and a half meters apart. Ten years later, in 1994, some of the same researchers, plus a new generation of students, began building the most grand-scale and magnificent forest experiment that had ever been attempted. They built huge ringed scaffolds 100 feet across, taller than the forest could ever grow, and they pumped carbon dioxide from massive tankers up through the pipes that lined the scaffolds, bleeding an extra dose of carbon into the air that the little trees used for growth.
The trees loved it: carbon dioxide fueled growth, and more and more carbon meant more and more growth. The deciduous understory decorated itself gaudily with lots of cheaply made leaves, while poison ivy vented its spleen by becoming even more poisonous. Across all this diversity, however, a general trend emerged: on average, most plants grew about 30 to 40 percent bigger at the higher levels of carbon dioxide than they did when grown at the normal ambient levels. It was perhaps the most important plant experiment of the 20th century, and it has since inspired thousands of spinoff experiments, such as the ones that I do in my lab, pushing to higher and higher levels of carbon dioxide, trying to find the point when more than enough becomes who cares how much.
Duke University’s Free Air CO2 Enrichment (FACE) experiment ran for 15 years and then, rather suddenly, it was ended, as were several other open-air CO2 experiments: the aspen forest in Wisconsin, the sweetgum plantation in Tennessee, the desert scrub in Nevada—all shut down within a couple of years. The reason that agencies cited was that the experiments were too expensive: it cost taxpayers more than $2 million each year to keep carbon dioxide moving through the scaffolding of Duke’s FACE forest. But there was another, more practical reason to end the experiment that was rarely mentioned: the trees had simply outgrown their scaffolding. They had thrived so much better and faster than anyone expected that they naturally had grown across the boundaries of the test plots and out into the real world. Fortified by health and maturity and untroubled by the constraints of the past, they confidently reached out into something new.
I am sometimes charged with allegorizing human endeavors by way of plant biology, so often lately that I’ve decided to start actually doing it. Right here, right now, I’ll suggest that the Internet is like carbon dioxide for science writers, who are themselves like plants, and that we are living in an unprecedented era of diverse and thriving journalism in the service of science—albeit one that could be cut off and mowed down if we don’t actively value and defend it. My goal with this volume of The Best American Science and Nature Writing was to bring forward the new and unusual topics and voices of 2016, and in so doing I have focused on three main themes: Emergent Fields, Changing Land and Resources, and The “Real Life” of Scientists.
The most precious currency of science is new ideas, and so I wanted to highlight especially the journalists who brought out the newest of the new. Entire scientific fields emerged during 2016, seemingly out of the ether, and they were as disparate as they were fascinating: Maria Konnikova wrote about neurogastronomy, a biosensual new approach to making food taste good, while Nicola Twilley described how the discovery of gravitational waves has revised our understanding of spacetime forever; these two stories perhaps form the perfect contrast between the tangible and intangible delights to be had from science. There is also the new science that we’ve only recently realized we need, such as Sarah Everts’s story on the new chemistry of artifact preservation, and then there’s the science that we didn’t even know existed, until Kim Tingley told us the story of how Micronesian explorers have navigated the Pacific Ocean for generations, without instruments, relying upon their unmatched understanding of ocean waves.
Two thousand sixteen was also a year of record highs: it was the warmest year ever recorded, both on land and within the oceans, its average temperature approaching one entire degree Celsius above the 20th-century average. Not unrelatedly, the carbon dioxide concentration within the atmosphere hit a new high, tipping the 400 parts-per-million mark, possibly for good and all. Only 30.1 percent of Earth’s surface was forested as of 2016, probably the lowest value since trees first evolved hundreds of millions of years ago. Global population is at an all-time high, as are crop and livestock production. The proportion of people who live in urban areas has skyrocketed to an unprecedented percentage, and energy use has followed suit. Science journalists spent much of 2016 reporting on how this is changing our planet.
While Elizabeth Kolbert wrote about ice melting in Greenland, Tom Kizzia was documenting the effects of climate change on Alaska’s Inupiat peoples. Our urban spaces got some of the attention that they deserve: Omar Mouallem wrote a graceful piece on light pollution, Tom Philpott reported on the factory farms that feed our cities, and Becca Cudmore questioned the role of rats within city ecosystems. Of special interest was Los Angeles, the most densely populated urban area in America: Nathaniel Rich divulged the mystery of its methane leaks, while Adrian Glick Kudler explored the significance of the famous Santa Ana winds. As the twin forces of globalization and industrialism proceed full force, our protected spaces are more important than ever, as Michelle Nijhuis illustrated with her piece on national parks. Picking up the theme, Christopher Solomon shared with us the myriad disagreements over protected land use in the American West, and Robert Draper told us the dramatic story of Virunga National Park, located in the Democratic Republic of the Congo.
Because 2016 was also the year that my own book, Lab Girl, was published, I was sensitive to stories that illuminated the life of the individual scientist and showed all the different ways that science can be practiced. Emily Temple-Wood enlightened us about several ancient and overlooked women scientists who should rightly take their place as role models for a new generation of students, while Chris Jones profiled modern-day astrophysicist Sara Seager. Several journalists told us the stories of scientists who did the unexpected, from Sonia Smith’s profile of Katharine Hayhoe and her quest to convince Christian evangelicals of the data demonstrating climate change, to Sally Davies on former physicist Fotini Markopoulou and her decision to leave everyday academia, to Michael Regnier’s report on the interesting story of George Price and his obsession with altruism. Some journalists went a step further and broke down the very idea of what it means to be a scientist, such as David Epstein on the “do-it-yourself” science of genetics and family history and Jon Mooallem’s thoughtful piece on the “amateur” cloud scientists who changed the field of meteorology. With her tongue placed firmly in her cheek, Ann Finkbeiner told us the real story of how “starshot” science gets funded when wealthy investors team up with overconfident experts.
Scientists and readers alike were obliged to continue questioning whether science is a place where women can thrive, after multiple lawsuits, investigations, and resignations associated with sexual harassment surfaced at high-profile institutions, including the University of California at Berkeley, the University of Chicago, the American Museum of Natural History, and the University of Washington at Seattle. In recognition of her fearless reporting in this area, I’ve made special inclusion of the article by Azeen Ghorayshi describing the incidents at CalTech that led to the unfair firing of a graduate student, as well as Kathryn Joyce’s piece exposing the infuriating reality that women are not safe while working within U.S. national parks and forests.
No one can argue that 2016 wasn’t a busy year: the scientists of the United States produced more than 400,000 (abstruse) journal articles, and the overworked science journalists of this our Internet Age diligently searched out, or perhaps accidentally stumbled upon, the most arresting, intriguing, mov
ing, beguiling of the bunch and then spun them up into stories for websites, magazines, and newspapers. Here I offer what I believe were the best of the best, the pieces that illuminated science as both glorious and tragic and shined a light on a great discipline that fosters both the best and the worst of what our institutions can be. The year 2016 proved to us once again that science is both essential and frivolous, jubilant and despairing, lovely and brutal, perfect and broken—all at the same time—just like the scientists who fashion it.
Hope Jahren
Part I
Emergent Fields
SARAH EVERTS
The Art of Saving Relics
FROM Scientific American
These suits were built to last. They were pristine white and composed of 20-plus layers of cutting-edge materials handcrafted into a 180-pound frame of armor. They protected the wearers from temperatures that fluctuated between –300 and 300 degrees Fahrenheit and from low atmospheric pressure that could boil away someone’s blood. On a July day in 1969, the world watched intently as astronaut Neil Armstrong, wearing one of these garments, stepped off a ladder and onto a dusty, alien terrain, forever changing the landscape both of the moon and of human history. Few symbols of vision and achievement are more powerful than the Apollo mission spacesuits.
Back on Earth, the iconic garments found new lives as museum pieces, drawing millions to see them at the National Air and Space Museum in Washington, D.C. And staff members there have found, to their surprise, that the suits need their own life support. They are falling apart.
Last year Lisa Young, a conservator at the museum, noticed that a white, foggy bloom was beginning to creep across the transparent fishbowl helmets and that their smooth, curved surface was beginning to crack. “It is really frustrating,” Young says. “We had thought they were relatively stable.” There had been warning signs of suit trouble, though. The neoprene pressure bladders that kept astronauts’ bodies from exploding in the vacuum of space began crumbling years ago, releasing acidic gases. “Anybody who has worked with the spacesuits knows their smell,” Young says. “I’d describe it as slightly pungent sweet chlorine.” And an orange-brown sticky stain began appearing on the exterior white fabric.
The trouble is the construction material: plastic. Most people think plastics last forever, which makes them a bane to the environment. But although the repeating units of carbon, oxygen, hydrogen, and other elements in plastics have a long lifetime, the overall chains—synthetic polymers—do not age well. Light conspires with oxygen and temperature to weaken the bonds that hold the units together. Then chemicals added to plastics to make them bendable or colorful migrate outward, making the surface sticky and wet and perfect for attracting dirt. The polycarbonate spacesuit visor, Young thinks, was leaching out a substance added to make it easier to shape.
Priceless 20th-century art is in serious trouble as well. In that era, Andy Warhol, David Hockney, and Mark Rothko all used acrylic paint—a plastic polymer popularized in the 1940s as an alternative to traditional oil paint. Plastic is, in fact, a building block of much of our recent cultural heritage, including important designer furniture, archival film, crash-test dummies, the world’s first Lego pieces, and Bakelite jewelry, as well as the plastic sculptures made by the pop-art movement. “We now know that objects made of plastic are some of the most vulnerable in museum and gallery collections,” says Yvonne Shashoua, a conservation scientist at the National Museum of Denmark and one of the first cultural heritage researchers to study plastic degradation.
The conservation field is now racing against time, trying to keep pace with the material’s unexpectedly rapid deterioration. Conservators have identified the most trouble-prone plastics. Scientists are developing new tools to diagnose plastic degradation before it becomes visible to the human eye—for example, by measuring the molecules wafting off artifacts. Researchers are also devising new strategies for freshening up precious plastic art without harming it, using everything from cleaning solutions called microemulsions to polyester microfibers that gently remove dirt.
Degrading Denial
The realization that plastics were a problem dawned slowly. For most of the 20th century the museum world was afflicted with “plastics denial syndrome,” Shashoua says. “Nobody thought that plastic objects in their collections would degrade.” In fact, some conservators were so enamored with plastic during its heyday of the 1950s, 1960s, and 1970s that they used the polymers in ill-advised ways themselves. For example, conservators laminated Belgium’s oldest parchment, the Codex Eyckensis from the eighth centuryA.D., with PVC plastic for protection. Decades later this laminate had to be painstakingly separated from the parchment because changes in the PVC began exacerbating the ancient document’s demise.
Crash-test dummies first made Shashoua think plastic was not forever. She had grown up visiting London’s Science Museum, where dummies built in the 1970s to better understand the human toll of automobile collisions were on display. The mock bodies—among the first of their kind—have a metal frame skeleton enveloped by medical gelatin that has been sculpted into human form and then covered by a layer of protective PVC. During impact tests, encapsulated red paint would bleed out of the gelatin bodies and get caught underneath the PVC layer wherever the dummy had smashed against a car frame during collision experiments. The red wounds indicated the body’s most vulnerable regions.
As the decades passed, these same crash-test dummies in the museum began bleeding again. Shashoua was shocked to see that the PVC covering these artifacts was collapsing, dripping so much wet, sticky muck that museum staff had set up petri dishes in the showcase to collect the mess. When Shashoua was put in charge of cleaning the artifacts in 2011, she noticed that the dummies’ sculpted contours were losing their definition as the PVC plastic collapsed; in some parts the red paint mixed with the wounded plastic, giving the goo dripping from the dummies an eerily realistic brownish red tinge.
This dripping mess—and in fact all kinds of plastic degradation—owes its start to oxygen. With help from light and heat, the gas rips off the electrons from the long polymer chains that entwine to form a plastic object. Losing electrons can weaken and break chemical bonds in a plastic, undermining its structure. Essentially the long chains break up into smaller constituent molecules called monomers. In the case of the crash-test dummies, this destabilization allowed ingredients called plasticizers, which are added to make the plastic supple, to pour out.
When the museum world began to realize that plastics were not invincible to time, those tasked with protecting plastic art and artifacts had to start from scratch to understand in detail why their collections were breaking down, says Matija Strlič, a conservation scientist at the Institute for Sustainable Heritage at University College London. Although there was extensive literature on polymer production, this research stopped at the end of a plastic object’s expected lifetime—right when conservators get interested, Strlič says. Polymer makers had probably expected that old plastic objects would get tossed away, not delivered to museums.
The Feared Four
Conservators learned that four kinds of plastic polymers are especially prone to problems: PVC, found in everything from spacesuit life-support tubing to crash-test dummies; polyurethane, a primary ingredient in products as diverse as pantyhose and packing sponges, as well as sculptures made from these materials; and finally cellulose nitrate and cellulose acetate, two of the world’s first industrially produced synthetic polymers, found in the film used in early cinema and photography as well as in artificial tortoiseshell items, such as vintage combs and cigarette holders.
Cellulose acetate and cellulose nitrate are not only fragile, they are also often referred to as “malignant” by conservators, Shashoua says. That is because they spread destruction to nearby objects. As their polymer networks collapse, they release nitric acid and acetic acid as gases. (Acetic acid is what gives vinegar its characteristic smell and degrading film an odor reminiscent of salad dressing.
) The acids eat away at objects made of these plastics. To make matters worse, their gases can also corrode metal and textile things in the same display case or nearby storage. That smell of vinegar is an alarm bell not just that these objects are destroying themselves but that the degrading polymer is taking down innocent bystanders as well.
Shashoua has seen fashion display cases where the acids from a degrading plastic comb have begun eating away textile outfits showcased with the comb or where the plastic in faux tortoiseshell eyeglass frames releases acid that corrodes the spectacles’ metal hinges. Once, in her own workspace, a box containing knives with cellulose nitrate handles began releasing nitric acid that corroded both the metal blades and the hinges of a cupboard near where the utensils were being stored, Shashoua says. To stop these chemical attacks, conservators may put objects made of cellulose acetate in well-ventilated spaces to whisk away the dangerous gases. They also capture the poisonous gases in the tiny pores of filters made from activated carbon and zeolite, in much the same way gas masks protect troops exposed to chemical weapons.
