by Hope Jahren
As it happens, the particular frequencies of the waves that LIGO can detect fall within the range of human hearing, between about 35 and 250 hertz. The chirp was much too quiet to hear by the time it reached Earth, and LIGO was capable of capturing only two-tenths of a second of the black holes’ multibillion-year merger, but with some minimal audio processing the event sounds like a glissando. “Use the back of your fingers, the nails, and just run them along the piano from the lowest A up to middle C, and you’ve got the whole signal,” Weiss said.
Different celestial sources emit their own sorts of gravitational waves, which means that LIGO and its successors could end up hearing something like a cosmic orchestra. “The binary neutron stars are like the piccolos,” Reitze said. Isolated spinning pulsars, he added, might make a monochromatic ding like a triangle, and black holes would fill in the string section, running from double bass on up, depending on their mass. LIGO, he said, will only ever be able to detect violins and violas; waves from supermassive black holes, like the one at the center of the Milky Way, will have to await future detectors, with different sensitivities.
Several such detectors are in the planning stages or under construction, including the Einstein Telescope, a European project whose underground arms will be more than twice the length of LIGO’s, and a space-based constellation of three instruments called eLISA. (The European Space Agency, with support from NASA, launched a Pathfinder mission in December.) Other detectors are already up and running, including the BICEP2 telescope, which, despite its initial false alarm, may still detect the echoes of gravitational waves from even further back in the universe’s history. Reitze’s hope, he told me, is that the chirp will motivate more investment in the field.
Advanced LIGO’s first observing run came to an end on January 12. Effler and the rest of the commissioning team have since begun another round of improvements. The observatory is inching toward its maximum sensitivity; within two or three years it may well register events on a daily basis, capturing more data in the process. It will come online again by late summer, listening even more closely to a celestial soundtrack that we have barely imagined. “We are opening up a window on the universe so radically different from all previous windows that we are pretty ignorant about what’s going to come through,” Thorne said. “There are just bound to be big surprises.”
Part II
Changing Land and Resources
BECCA CUDMORE
The Case for Leaving City Rats Alone
FROM Nautilus
Kaylee Byers crouches in a patch of urban blackberries early one morning this June to check a live trap in one of Vancouver’s poorest areas, the V6A postal code. Her first catch of the day is near a large blue dumpster on “Block 5,” in front of a 20-some-unit apartment complex above a thrift shop. Across the alley a building is going up; between the two is an overgrown paper- and wrapper-strewn lot. In the lot there are rats.
“Once we caught two in a single trap,” she says, peering inside the cage. She finds a new rat there and makes a note of it on her clipboard; she’ll be back for it, to take the animal to her nearby van, which is parked near (according to Google Maps) an “unfussy” traditional Ethiopian restaurant. Once inside the van, the rat will be put under anesthesia and will then be photographed, brushed for fleas, tested for disease, fixed with an ear tag, and released back into V6A within 45 minutes.
Byers is a PhD student under veterinary pathologist Chelsea Himsworth, a University of British Columbia School of Population and Public Health assistant professor who has become a local science celebrity thanks to her Vancouver Rat Project. Himsworth started the project as a way to address health concerns over the city’s exploding rat population—exploding anecdotally, that is, as no one has counted it.
Prior to Himsworth’s work, in fact, the sum total knowledge of Canada’s wild rats could be boiled down to a single study of 43 rats living in a landfill in nearby Richmond in 1984. So six years ago she stocked an old minivan with syringes, needles, and gloves and live-trapped more than 700 of V6A’s rats to sample their DNA and learn about the bacteria they carried.
Her research has made her reconsider the age-old labeling of rats as invaders that need to be completely fought back. They may instead be just as much a part of our city as sidewalks and lampposts. We would all be better off if, under most circumstances, we simply left them alone.
Rats thrive as a result of people. The great modern disruptions caused by urban development and human movement across the world have ferried them to new ecological niches. “Rats are real disturbance specialists,” says biologist Ken Aplin, who has studied the rodents and their diseases for decades. “Very few wild animals have adapted so well to the human environment without active domestication.” Rats invade when ecosystems get disrupted. In terms of the bare necessities, “rats need only a place to build a burrow (usually open soil but sometimes within buildings or piles of material), access to fresh drinking water, and around 50 grams of moderately calorie-rich food each day,” according to Matthew Combs, a doctoral student at Fordham University who is studying the genetic history of rats in New York City. In a human-dominated landscape like New York or Vancouver, “It comes down to where rats have found a way to access resources, which often depends on how humans maintain their own environment.”
It’s not hard to understand why humans often think of the rat lifestyle as a parasitic response to our own. But that’s not entirely true. “I have to stop myself sometimes because I want to say that rats have adapted to our cities,” says Combs. The reality is that rats were perfectly positioned to take advantage of the disruptions caused by human settlement long before we arrived. They’ve been on Earth for millions of years, arriving long before modern humans evolved, about 200,000 years ago. Before cities were even a glimmer in our eye, rats were learning to become the ultimate opportunists. “They were likely stealing some other species’ food before ours,” Combs says. Even in the still-remote mountain habitats of New Guinea, says Aplin, “you tend to find rats living in landslides or along creek systems where natural disturbance is going on.” Walk into a lush, primary, intact forest, “and they’re pretty rare.” It’s not that rats have become parasitic to human cities; it’s more correct to say they have become parasitic to the disturbance, waste, construction, and destruction that we humans have long produced.
Which brings into question the constant human quest to disrupt rats and their habitats. As much as rats thrive in disrupted environments, Byers says, they’ve managed to create very stable colonies within them. Rats live in tight-knit family groups that are confined to single city blocks and that rarely interact. The Rat Project hypothesized that when a rat is ousted from its family by pest control, its family might flee its single-block territory, spreading diseases that are usually effectively quarantined to that family. In other words, the current pest control approach of killing one rat per concerned homeowner call could be backfiring, and spreading disease rather than preventing it.
The diseases that rats might be spreading aren’t just their own. Himsworth likes to say that Vancouver’s rats are like sponges. Their garbage-based diets allow them to absorb a diverse collection of bacteria that live throughout their city, in human waste and in our homes. “So it’s not like the presence of harmful bacteria is characteristic of the rats themselves,” she says. They get that bacteria from their environment, and when they move, they take these place-specific pathogens with them.
When “stranger” rats come into contact, Byers says, territorial battles ensue. “They urinate out of fear and they draw blood,” she says—perfect for expelling and acquiring even more bacteria. It’s during these territorial brawls, Byers and her colleagues believe, that bacteria can converge, mix, and create new diseases. “The rat gut acts as a mixing bowl,” says Himsworth, where bacteria that would otherwise never interact can swap genes and form new types of pathogens.
One example is a strain of methicillin-resistant Staphylococcus aureus, or MRS
A, that Himsworth found in V6A’s rats. It included a piece of genetic material from a very closely related superbug called methicillin-resistant Staphylococcus pseudintermedius, or MRSP, which is often only associated with domestic animals like pet dogs. It seems that rats pick up human MRSA from the sewers or the streets and canine MRSP from our yards, then mix them in their guts. These new human-rat bugs could then potentially spread back to people via the rats’ droppings and saliva.
In V6A it’s hard not to notice the litter around us. Garbage has bubbled out from under the lids of trashcans, and a pile of empty syringes surrounds a parking-lot trap. Walking across this landscape of debris, cracked concrete, and weeds, Byers stops at another trap, which is set on what she has named “Block J.” She and two student assistants are heading the project’s second phase, which involves tracking the real-time movement of rats, using ear tags. Once these trees are mapped, she will begin to euthanize individual rats and see how their family responds. Part of her PhD work is to understand how human-caused disruptions, pest control in particular, affect how rats move throughout V6A. The hypothesis is that the disruption will send communities scurrying for new ground. With nearly 100 cages to check today, Byers moves hastily to a trap on Block 8. No rat here, but this one did catch a skunk.
A significant finding from the project’s original phase, Byers tells me, is that not every rat in V6A carried the same disease. Rat families are generally confined to a single city block, and while one block might be wholly infected with a given bacteria, adjacent blocks were often completely disease-free. “Disease risk doesn’t really relate to the number of rats you’re exposed to as much as it does to which family you interact with,” says Robbin Lindsay, a researcher at Canada’s National Microbiology Lab who assisted the Vancouver Rat Project screen for disease. If those family units are scattered, diseases could potentially spread and multiply—something Byers is hoping to figure out through her PhD work.
If that’s true, a city’s rat policy should include doing the unthinkable: intentionally leave them where they are. “It might be better to maintain local rat populations that already have some sort of equilibrium with the people who live there,” says Aplin. Many of the diseases that we share with rats are already part of a human disease cycle established over centuries, he says. Seen this way, rats are irrepressible—“a force of nature, a fact of our lives.” Rather than focusing on killing them, we need to try to keep their populations stable and in place—and that includes managing rat immigrants.
An established rat society in a neighborhood makes it a much less viable destination for other rats, for example those entering through ports. Exotic rats can be more of a threat than those adapted to the region because each rat community evolves with its own suite of unique pathogens, which it shares with the other vertebrates in its ecosystem. New rats mean new diseases. The big question now, Aplin says, is “what happens when these different pathogens come together? This is something that I’m just starting to think about now. If the local rat population is suppressed, if you’re actively getting rid of it, then you’re also actively opening up niches for these foreign rats to enter.”
In Vancouver, this is a fact of life. “One important thing we do have right over there,” says Byers, motioning with her left hand, “is Canada’s largest shipping port.” Vancouver sits on Vancouver Harbor, which houses the great Port of Vancouver. In one of Himsworth’s earlier studies, she found mites on the ears of rats that live by the port and compared them to rats that take up residence around V6A. Port rats had malformed ears full of a strange breed of mite previously unknown to Canada—“an exotic species that’s found in Asia,” Himsworth says, which happens to be where Vancouver gets the majority of its imports. These foreign ear mites were not found on rats from any other block.
“So I think Aplin’s theory has a lot of merit,” Himsworth says. “It seems that the established rat population at the port acts as a buffer.” Himsworth wonders if this is precisely what has kept an otherwise highly contagious mite from spreading throughout V6A.
Disruption, of course, doesn’t come from just ports and pest control. It is part and parcel of modern civilization. Vancouver’s population is growing steadily (by about 30,000 residents each year), bringing housing development, demolition, and more garbage. Even our love of birds can be a problem. Two years ago, for example, rats invaded a playground and community garden in East Vancouver, a bit outside of V6A. Several media sites reported on the visitors, which were evidently drawn in by birdseed dropped by a single individual. The area soon became known as “Rat Park.” The City of Vancouver urged the garden’s coordinator to put up signage asking people to avoid feeding the birds and to pick up their overripe vegetables. An exterminator was hired as well—adding more disruption still.
Himsworth hopes the new science will sway Vancouver’s existing policy on rats, which, she stresses, is currently “essentially nonexistent.” This bothers her a lot. “I know that Vancouver Coastal Health essentially has the standpoint that, ‘Well, we don’t see the disease in people so we don’t worry about it,’ ” she says of the region’s publicly funded health-care authority. Homeowners with rat infestations can ring 311, Canada’s 411, to report an infestation, but that’s not a preventative response. “Rats are pests, and we don’t spend health-care dollars to track pests,” said media officer Anna Marie D’Angelo of Vancouver Coastal Health. It was a message echoed by issues management communications coordinator Jag Sandhu of the City of Vancouver: “The City of Vancouver does not track the rat population.” To Himsworth, this is shortsighted. “They’re not taking the rat disease risk seriously because they haven’t seen it in humans yet—but that’s not where diseases start.” She also believes the issue is in part one of social justice. Rats typically affect poor areas, like V6A, that have little political clout.
Back inside one of Byers’s traps in V6A, needlelike nails are lightly scraping on the metal. “It’s a black rat,” Byers tells me—the famed carrier of the Black Death. Byers says she isn’t concerned about bubonic plague, which in North America is mainly carried by prairie dogs. But there were 13 rat-driven bubonic plague outbreaks in seven countries between 2009 and 2013. And there are plenty of new diseases cooking.
ROBERT DRAPER
The Battle for Virunga
FROM National Geographic
When the ranger studied the ragtag crew he was supervising, seven young men repairing a rugged road that leads to Virunga National Park, it did not take much to see what he had in common with them. They were all born and raised in or around the park on the eastern edge of the Democratic Republic of the Congo. None of them were rich. None of them would ever be rich. All of them had seen loved ones fall by the capricious machete stroke of a war with murky logic and no foreseeable end.
And now here they all were, working for the park, filling potholes and clearing drainage ditches in the furtherance of something considerably more profound than nine miles of rough gravel. The road joins the Bukima ranger post with tourists from the West, whose money helps support Africa’s oldest national park. These visitors come here principally to fulfill a dream—namely, to stand mere feet away from the park’s illustrious residents, the rare mountain gorillas.
Less famous but just as important, the Bukima road connects farmers outside the park with village markets and the city of Goma beyond. For years it had been a morass of large rocks and quicksandlike mud. Its impassability made hard lives that much harder. But now the park was pouring money into the road’s reconstruction. And local men like these were repairing it. So the road also constituted a bond, albeit a slender one, between the region’s most visible national institution and villagers who view the park with hostility, and at times rage, believing the land should still belong to them.
Here was where the ranger, a captain named Theo Kambale, parted ways with the young men. Kambale’s heart held nothing but reverence for the park. You could see it in the crispness of his uniform, the care with which
he tucked his green pants into his boots, which he fastidiously polished. Kambale was 55 and had spent 31 of those years as a ranger. His father, also a ranger, had died in 1960, the year of Kambale’s birth, gored by an African buffalo. His older brother had also been a ranger. He too had been slain in the line of duty, in 2006. The killer was not a wild animal but instead a member of one of many armed groups that have ravaged and occupied Virunga for two decades.
To these young men raised in poverty, that Virunga’s tremendously fertile soil, its trees, and its creatures should be protected by law for the viewing pleasure of well-off tourists struck them as a grave injustice. They were swept into a militia known as M23, which touted a host of grievances against the corrupt government but in the meantime was content to loot and rape its way through a slice of eastern Congo near the park’s southern sector. By the end of 2013, after more than a year and a half of fighting, the Congolese Army, backed by United Nations troops, routed M23. Among the militia’s foot soldiers deemed salvageable, by UN peacekeepers and park officials, were these seven.
The work on the Bukima road was harder and less profitable than looting. But the former rebels kept at it. Kambale was impressed. He talked to them from time to time. “Before now, all you were creating was insecurity in the region,” he would say. “Now you’re building this road. It’s a start. From here you can go on to do other things. But you can’t progress if there’s no security. So tell that to your friends. Tell them to leave their armed groups. Because that is not life. This”—and he would gesture toward the road—“is the beginning of life.”
The ranger hoped that his message would sink in. He knew of their desperate backgrounds. He was aware that most had been conscripted by force. Across their arms and backs was a grisly network of scars, testifying to their semi-enslavement. Seeing these men in their 20s permanently marked by brutality, Kambale thought of his own injury, delivered by a militia spear to his right leg. Proof of residency, you could say. If they could look past their battle wounds, perhaps this park could be saved.
