As he has watched the aftermath of school shootings this year – including a massacre Friday in Santa Fe, Texas – Carson Collins has felt the pressure to grieve and move on. But that impulse, he told his dad, has been countered by an even stronger urge to not let go.

In December, a 21-year-old former student walked into Aztec High School in New Mexico with a gun. Carson, a senior, was one of those locked in a classroom, ready along with his fellow students to charge the shooter in the hallway right outside. Instead, the man killed himself after killing two students.

Reacting to an effort at Aztec High to help students heal by cheering them up, Carson told his dad: “When you think about it, it’s like you get punched in the gut ... and then they tell you to smile. I’m not prepared to smile.”

That sense of siege is being felt across the country as the school year draws to a somber close. “Everyone’s just talking about, ‘I hope we can make it to the summer, [that] nothing happens before ... we can get out of this place,’ ” says Marcel McClinton, a junior at Stratford High School in Houston.

Interviewed after traveling to Santa Fe to show his support for the community, Marcel and his fellow student activists represent an impulse that goes back almost two decades to Columbine High. After all, those students also lobbied Congress for curbs on gun purchasing. They failed, as did similar efforts by parents after the Sandy Hook shooting in Connecticut in 2013.

But this year, the March for Our Lives movement launched by survivors of the Parkland, Fla., shooting, has been boosted by a changing national mood and  a generation that has put a new moral framework on the issue and is, by multiple measures, less violent than the ones before it. These students aren’t talking about jobs or the beach but rather about a summer of activism and soul-searching, seeking a sliver of hope that the United States will find a way to better protect its 50 million public school students. Last week, student activists announced dual campaigns: a summer tour to raise awareness and a voter registration drive to challenge politicians who oppose gun control measures. The appeals are already “moving the country like I have never seen,” former education secretary Arne Duncan told an education conference in San Diego last week.

“There is a very strong sense on this issue ... that we as a nation are at a breaking point, and the status quo feels to so many of us to be unsustainable,” says Angus Johnston, who studies the history of student activism at the City University of New York. “We feel complicit. And that, for a lot of us, is new.”

Nearly 20 years after the Columbine High School shooting in Colorado, two-thirds of US schools hold active shooter drills. Metal detectors have become ubiquitous. Increased guard patrols have likely reduced casualty tolls, and teachers in some districts are urged to come armed to class. Still, so far this year, the US has seen 13 school shootings where people were killed or injured, leaving a total of 32 dead and 65 injured – more than the casualty toll for America’s military.

Jonathan Bachman/Reuters

On May 21, mourners pray at a makeshift memorial left in memory of the victims killed in a shooting at Santa Fe High School in Santa Fe, Texas.

“People are fed up with this idea of ‘now is not the time to talk about it,’ ” says Columbine survivor Paula Reed, who is still a teacher at Columbine. “Now is the time to talk about it. It just is.”

Historical trends upturned

Despite the headlines around mass shootings, younger Americans as a whole are bucking historical violence trends, to the point where teenagers are now more likely to have to bail their parents out of jail than the other way around, according to one juvenile crime expert.

“If you tell people that this generation of teenagers is less than half as likely to get shot to death as 25 years ago, people would think you are crazy, but it’s true,” says Mike Males, a researcher with the Center on Juvenile and Criminal Justice in San Francisco. “There is something about this generation that is more gun-averse than other generations, which is why I think they do speak with authority.”

And while the students march and help their peers to sign up to vote, state and federal governments also are searching for solutions – aware that the usual narrative is no longer seen as adequate. Gov. Greg Abbott began convening round tables Tuesday to discuss a way forward for his state, which is grappling with not only the Santa Fe shooting, but the massacre at a church in Sutherland Springs. “We want to hear from everybody,” he said.

Range of responses

In New Mexico, Aztec Municipal School District is one of a growing number of districts introducing the “Say Something” app created by parents of Sandy Hook victims. It allows students to anonymously report tips about disaffected classmates.

Last week, President Trump’s school safety commission met to discuss a federal response. Lawmakers on both sides of the aisle have sought new resources for mental health and safety, most prominently by increasing funding for the federal Student Support and Academic Enrichment grants, by $700 million, to $1.1 billion.

About 200 universities and national education and mental health groups have signed onto the “Call for Action” program to prevent gun violence, rooted in proven methods for identifying and helping students who see violence as a solution to their angst.

In Florida’s Broward County, several of the Parkland victims’ parents are running for school board, determined to turn their frustration and grief into lasting change.

And student activists have vowed to keep up their rallies through the summer. A June 21 “die-in” event is planned in Washington for the second anniversary of the Pulse Night Club shooting.

“The most important thing ... is to keep remembering the victims and to keep them in our hearts,” says Nathan Dominguez, a March for Our Lives activist in Newton, Kan. “The second thing that we really need to remember is that the people on the other side of the aisle, we’re also doing this for them. We can’t make them out as our enemy. Those are our fellow Americans and they’re important in this process.”

Alexandria Aldred, a senior at Havelock High School, in North Carolina, was one of thousands who walked out of school earlier this year in protest. Her focus is on voter registration and gun control. But she says she is also keen to work with people who think differently about those issues.

“When I come across those [who disagree] I try to keep things level ... I try to keep it an adult-to-adult conversation where it’s calm and it’s not led by hate or emotion, it’s led by facts,” she says.

“There are a lot of people who believe that high-schoolers shouldn’t be involved in politics and that a lot of us don't know what we’re talking about,” Alexandria adds. “People need to start listening to us because at this point we know what we're talking about because ... we go to school with the fear in the back of our heads that we might not make it out of there today. And so I think that our opinions really matter and the older generations need to start listening.”

School board member: 'I need to step it up'

Roger Collins reacted to the Aztec shooting first by being a dad, making sure his two kids, including Carson, were safe. But his position as a school board member has also been affected, he says, in part by his town’s tragedy, but also by the response from his son and others of his generation.

“If kids are doing more than I am doing, I need to step it up for sure,” says Mr. Collins. “They brought that dialogue to the country and got people to the same table to discuss what schools are doing. They began the whole process of change. That makes you try to figure out what’s best for you and how can you try and make a difference in this community.”

For Sterling Haring, the activism has been enough to break his “physician’s silence” – an impulse by doctors to not get involved in politics.

Last month, Dr. Haring spoke at two March for Our Lives events, one in Nashville, the other in Benton, Ky., where two people died and 18 others were injured in a January shooting. Haring was one of the physicians at Vanderbilt University Medical Center in Nashville who treated the wounded from that school shooting. One of the teenagers rushed to his hospital died.

“There are those who have the luxury of becoming numb to this – and there are those of us who do not,” says Haring, a gun owner who says his hospital taken care of victims of three mass shootings in the past year: a Waffle House shooting, the Benton school killings, and the Antioch, Tenn., church shooting. “In the past, we've had these very taboo subjects – to remain friends with somebody you can't talk about things like guns – but I feel that’s kind of passing. No. 2, we’re starting to call a spade a spade. This has happened enough that the normal excuses aren’t working.”

The reaction in Santa Fe has been different from the one after Parkland. It is a far more rural and conservative town, for one thing.

Yet Marcel, the student from Houston, says that a broader sense that something is going amiss is being heard in Santa Fe, too. After attending a Sunday vigil and a youth group, he received a text from a group of girls who didn’t want to join March for Our Lives, but did want the group to help them get their message out.

The girls’ wish to shape their own protest was particularly telling to Marcel, who survived a mass shooting near Memorial Drive United Methodist Church in Houston in 2016.

“It is important to note that Houston, Dallas, and Austin are not Texas; Texas is Santa Fe,” he says. “Texas is rural, conservative communities where ... these kids are gifted shotguns when they’re 10, 11 years old. That’s their culture. I understand their culture. That is who they are. But as we approach these communities when things happen ... the story is not that the shooting happened. We know it happened. The story I think should be: Where do you move from this?”

Staff Rebecca Asoulin and Noble Ingram contributed to this report from Boston.

Jonathan Ernst/Reuters

Secretary of State Mike Pompeo delivers remarks on the Trump administration's Iran policy at the Heritage Foundation in Washington on May 21, 2018.

British Foreign Secretary Boris Johnson tried to be as polite and diplomatic as possible in assessing the Trump administration’s post-nuclear-deal Plan B for dealing with Iran.

Point 1: Secretary of State Mike Pompeo – who on Monday announced the new plan, which aims to “crush” Iran with “the strongest sanctions in history” – is “a great guy,” Mr. Johnson said.

Point 2: That said, the new plan faces a steep uphill battle – particularly in bringing on board the international community, without which any plan to constrain or alter Iran’s behavior cannot succeed.

The new US vision appears to fold several issues – “ballistic missiles, Iran’s behavior, Iran’s disruptive activity in the region, nuclear activity” – into a “new jumbo Iran negotiation,” Johnson said Monday, adding that “I don’t see that being very easy to achieve in anything like a reasonable timescale.”

Mr. Pompeo may have hoped for better. But the reality is that the threat of deep divides between the US and its allies, and primarily with the three European countries – Britain, France, and Germany – that are party to the 2015 Iran nuclear deal had loomed large as President Trump pledged over the past year to exit the deal if it couldn’t be fixed to his satisfaction.

Now that the US is out of the deal, the fissures have begun to form. Pompeo seemed to recognize that, calling for formation of a broad coalition of countries that would supersede the small group of six world powers that reached the 2015 deal with Iran.

But the Trump administration may soon discover how effective it can be in addressing a key national-security concern like Iran without its most powerful allies at its side.

Moreover, an administration that has often been more confrontational than cooperative with the community of nations may now pay the price as it seeks to build the kind of broad coalition the US has generally turned to over recent decades to secure its foreign-policy goals.

Partners beyond Europe

Pompeo used his appearance Monday at Washington’s Heritage Foundation to point out the differences with the Europeans over how to address the full range of Iran’s “malign behavior” – and to shift the focus to other partners he says see eye-to-eye with the US on Iran.

“We focus on the Europeans, but we have scores of partners around the world who have similar concerns” to ours, Pompeo said in unscripted comments following his speech.

As for the Europeans, they made it clear in a statement from the European Union’s foreign affairs chief, Federica Mogherini, that the EU “will remain committed to the continued full and effective implementation” of the Iran nuclear deal – and that the Europeans see the US as the odd man out for having abandoned a deal “that belongs to the international community.”

Some foreign policy analysts predict that the principal beneficiary of the splits now forming over Iran will be Iran itself – or at least the hardliners in the regime. They foresee Iran moving to take advantage of an international community distracted by its divisions and unable to effectively address Tehran’s provocations.

“What the Iran deal had going for it and what brought Iran to the negotiating table was the solid unity and very tough sanctions of the international community,” says Robert Einhorn, a former State Department special adviser on nonproliferation. He had a key role in fashioning and then selling internationally the economic sanctions the US promoted in 2012 to get Iran serious about negotiating constraints on its nuclear program. “But a US that is out of the deal is going to have a very difficult time reassembling the united sanctions coalition from before,” he adds.

Beyond that, he says Iran is going to do everything it can to paint the US as the outlier, and to exploit the deepening divisions in an international community that once confronted it from a united stance.

“They want to isolate the US and get the Europeans on their side,” says Mr. Einhorn, noting the Europeans’ stated objective of preserving a deal they maintain Iran is upholding. “It will be a huge propaganda victory for the Iranians if the Europeans side with them.”

Iran wasted no time in stoking the irritation the world often experiences when it feels dictated to by the US – an irritation that had been soothed to some degree by the US commitment to the Iran deal, known formally as the Joint Comprehensive Plan of Action [JCPOA].

The world will “not accept” American unilateralism, Iranian President Hassan Rouhani declared shortly after Pompeo’s speech Monday. The era of the US making decisions for the rest of the world “is over,” he said.

Choice between US, Iran

Yet given a choice between the US and Iran, most countries – certainly including the Europeans – are still going to choose the US, some foreign-policy analysts say. That opens the door for a diplomatically engaged US to make its case and build the “broad coalition” Pompeo envisions, they add.

“I’m not saying it’s going to be easy, but even under Donald Trump the US is still the indispensable nation … that for many countries is a valued strategic and commercial partner,” says Mark Dubowitz, who heads the Foundation for Defense of Democracies, a Washington think tank favoring tough sanctions on Iran. “In any US-Iran escalation, they aren’t going to risk those vital ties [to the US] for the Iranian regime.”

The Trump administration should focus on winning over the national leaders of its European allies (as opposed to EU leaders like Ms. Mogherini), Mr. Dubowitz says. “If it were up to me, I’d have [French President Emmanuel] Macron convene this broad coalition in Paris with the strong support of the US,” he says. Mr. Macron “has said he, too, wants a comprehensive plan for dealing with Iran, so let’s encourage that.”

Einhorn, now a senior fellow in arms control and nonproliferation at Washington’s Brookings Institution, says that at the end of the day, Europe’s largest companies and banks will sever their commercial ties to Iran rather than risk running afoul of new and re-imposed US sanctions.

But on the other hand he foresees little or no effort by many other countries – China and India, for example – to comply with US demands concerning Iran. And that lost unity will make confronting Iran more difficult.

“We’re going to find the world divided into different camps now on Iran,” Einhorn says. “The Trump administration is asking for much, much more than what was contained in the JCPOA, and with much less leverage than we had” with pre-Iran-deal sanctions, he says. “They’re going to find it’s hard to do more with less.”

It was April 7, 2012, and on the dusty floor of his tiny pharmacy, Vincent Anibueze was waiting to die.

Outside, gunshots came like bursts of static from an untuned radio. He heard screams and heavy footsteps. “Gashinan!” someone yelled. There he is.

Inside the little tin store, Mr. Anibueze lay face down where he had dived to the ground when the first shots rang out. Inches away, a man was slumped across the consultation table. Not long ago, that same man had walked brightly into the shop, gripping the hand of his young son, asking about this and that treatment.

Now, he was motionless. Only his lungs moved.

Anibueze thought of what Aisha would do when he was gone. She was quiet, his wife, but she was determined. Back when they first met and her mother had forbidden her to marry him, a Christian, Aisha had stood her ground. She wouldn’t let this destroy her.

A mile away, Aisha heard the gunshots too. It sounded to her like they were coming from the neighborhood of Gwange, the direction of her husband’s shop. Before she could register anything else, a neighbor ran up and gripped her arm. “Boko Haram shot someone in his store,” she said.

“Whose store?” Aisha asked.

“Vincent’s,” the neighbor said, and Aisha’s vision went black.

***

This wasn’t how things were supposed to end. Not in Maiduguri, whose faded “Welcome to…” sign proclaimed it “the home of peace.”

For decades, Maiduguri had been northeastern Nigeria’s melting pot: a brusquely cosmopolitan trade hub and occasionally raucous college town on the edge of the Sahel. Ancient bug-eyed Mercedes cargo trucks rumbled through the city carrying peppers, fish, charcoal, and cow hides from as far as the Central African Republic and Sudan. Along Babban Layi, the city’s main commercial drag, traders from Lagos, Lebanon, China, India, Chad, Niger, and Cameroon hawked everything from bananas to Samsung fridges, flicking through wads of naira notes under the awnings of their small shops. And on the campus of the University of Maiduguri, students from across Nigeria and beyond threw parties, crammed for botany exams, and debated feminism.

Karen Norris/Satff

Though the city had always been mostly Muslim, for most Maidugurians, religion was never a social divide.

“It’s always been said of Maiduguri that you can come in the middle of the night as a stranger and no one will fear to give you a place to sleep,” says Muhammad Muhammed, a local Muslim cleric.

For Vincent, that reputation was alluring. A devout Anglican from Nigeria’s southeast, he had worked for years in Kano, a mostly Muslim city in the northwest. But a series of violent religious riots in the early 2000s had begun to wear him down. “I wanted to live in a free place and I heard Maiduguri was that,” he says.

Not long after he arrived in 2005, he joined a local soccer team. At the house of one of his teammates, he locked eyes with the man’s younger sister.

“Pretty soon my friend got the feeling I wasn’t really coming to visit with him anymore,” Vincent says.

Also: “He was right.”

“I didn’t notice him, not like that,” Aisha says. “He was just the pharmacist, honestly.”

But after a few months, she began to realize she was lingering in his small shop long after she had paid, filling him in on what customers were saying in Kanuri, the local language, and offering bits of advice about his new city.

“Hello, baturiya,”  he called her teasingly each time she walked through the door, using the local word for white person – a nod to her fair complexion. He got her to laugh, “and she could really laugh,” he says.

Soon, both of them realized where this was headed. But for their families, a Muslim girl and a Christian boy was uncharted territory. At first, Aisha’s mother told her no – absolutely not. He’d try to convert her, she said.

It was Aisha’s grandparents who finally convinced her mother. This girl knows what she wants, they told her. Without her family’s blessing, she’d simply run away with him.

In 2008, the couple got married. And then, as if waiting for its cue, Maiduguri began to fall apart.

The rumblings of trouble had started several years earlier, when a local cleric named Mohammed Yusuf had begun preaching an angry, anti-establishment brand of Islam. Northern Nigeria had been abandoned by the country’s government, he said, and poisoned by Western education. It needed its own Islamic state. In a poor region with many listless men, that message quickly took root. Local observers dubbed Mr. Yusuf’s new group “Boko Haram,” often translated as “Western education is forbidden.”

At first, the movement was largely nonviolent. But in 2009, Nigerian police opened fire on a group of sect members, ostensibly after they refused to comply with a motorbike helmet law, setting off a bloody retaliation. Eight hundred people died in the fighting, and soon Boko Haram was flogging the city of its birth, indiscriminately attacking public spaces and bombing schools, hospitals, and mosques.

And in the middle of it all, Aisha was pregnant.

“That was when I started begging Vincent to leave,” she says. She’d heard rumors that Boko Haram was targeting pharmacists, and thought being Christian alone seemed like wearing a target on your back.

But the community had always treated Vincent as one of its own, he reassured her. Their business thrived. Aisha gave birth to their first child, and then, two years later, their second.

“People were surprised that our marriage worked,” she says. “But I told them that when you come from different places, you have to be open to understand each other. You can’t have any secrets. It makes you stronger.”

***

Fifteen minutes after the first shots, the men came back. This is my last moment in the world, Vincent thought as he lay on the cold cement. But then the attackers seemed to notice something. Hunched on the floor, weeping quietly, was a little boy. The son of the man slumped across the table.

Wordlessly, the two men with guns turned for the door. Vincent heard the throaty rattle of a motorcycle starting up, and then they were gone.

And a few seconds later, Vincent was too. He started running and didn’t stop until he reached a friend’s house.

Meanwhile, two police officers were knocking on Vincent and Aisha’s front door. It wasn’t him, they told her. The man shot inside the pharmacy, it wasn’t him.

She began to cry.

But it wasn’t over. The next day, Vincent left town, and then looters carried off what was left of his shop.

When he finally came back, a year and a half later, in late 2014, Boko Haram was mostly gone, driven out by the army and a civilian militia. But the couple was broke. And they were scared. When her grandparents asked them to send their three small children to stay with them in their village in Chad, they reluctantly agreed.

They had always promised, they reasoned, that their kids would one day live in all the places their families had come from.

“We always agreed, the kids won’t have to make a decision about what they are until they’re grown,” Aisha says. “Our job was just to expose them to everything.”

And so, back in Maiduguri, the couple tried to carry on.

Vincent opened a new pharmacy. Aisha had another baby.

And the city around them seemed to be rising again too. The streets, once deathly silent after dark, filled again with shopping women and loitering teenagers. Freed from military curfews, families queued up at a Chinese-run bakery to buy sweating tubs of ice cream for dessert on hot Sahelian nights. On weekends, chaotic, colorful Kanuri weddings once again filled the streets.

Boko Haram still sporadically lashed the city, and many of the roads in and out of Maiduguri remained littered with explosive devices planted by the group. In other parts of the northeast, meanwhile, attacks and kidnappings continued, despite the government’s insistence that it had defeated the insurgents. Visiting the children was nearly impossible.

But still, it was something.

By last year, Aisha had begun to think of bringing the older children back. Vincent imagined that when the insurgency was over, he would train to become an Anglican priest and open his own church here.

“I’ll preach tolerance,” he says. “I’ll tell people, marry who you love.”

Saildrone.com/Stanford University

A Saildrone passes the California coast on the way to a mysterious portion of the Pacific Ocean known as the White Shark Café.

The regular patrons of the White Shark Café have had some company lately.

In March, two autonomous robots, called Saildrones, departed from California en route to the “Café,” a mysterious stretch of water in the middle of the Pacific Ocean where the sharks are known to congregate. This week, they were joined by a ship carrying 14 scientists and a vast array of ecological monitoring instruments. Researchers know little about this region – and why it attracts the massive predators – but these reddish-orange sailboats are a crucial step toward learning more. 

Their collective journey began with a discovery by Barbara Block, a biologist at the Hopkins Marine Station of Stanford University in Pacific Grove, Calif. Dr. Block’s team had been tagging white sharks for seven years when they noticed something peculiar in 2006. For several months, most of these sharks abandoned the coastline for the open ocean. But they weren’t just dispersing randomly into the Pacific: They were headed somewhere specific, a patch of ocean about halfway between Hawaii and California.

Once there, the sharks behaved in profoundly unusual ways, diving down almost 500 yards and then resurfacing – and doing it hundreds of times a day. Researchers first called the region an “offshore focal area.” Since 2009, Block and her colleagues have simply called it the White Shark Café.

While satellites can record images of the Café – which is thousands of miles away from Block’s office in Monterey, Calif. –  from above, their radio waves can’t penetrate below the surface. So what the sharks are doing remains unclear. “It’s as if they’re searching for something, and we’re sitting back here trying to figure out what it is they’re searching for. Is it food? Is it each other?” Block asks.

Those questions may soon have an answer. The two Saildrones are equipped with a number of sensors, including an echosounder, which sends pulses of energy 500 yards into the water column and records every organism in range. Having supplied data for weeks, the drones are now helping identify researchers’ next steps.

“I love the idea of this presence. It’s almost like having your own instruments there,” Block said before departing. “When it’s rough out there, it’s really nice that I’ve got these quiet Saildrones showing me what it used to take a whole ship and weeks of time and effort to do.” 

Saildrones aren’t the first autonomous devices employed in marine science, but since their 2014 release they have been lauded for their utility. These boats are much less expensive to operate than ships, and because they’re wind- and solar-powered they can travel uninterrupted for months. Their 23-foot frames are also small enough to pass through sensitive ecosystems without scaring wildlife. Globally, Saildrones are helping scientists capture a more complete picture of some of the world’s most remote waters. 

Since 2015, Jessica Cross has been using Saildrones to investigate one particularly inaccessible region: the Arctic. Last year, Dr. Cross, a research oceanographer at the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle, helped deploy three Saildrones in collaboration with NOAA's Alaska Fisheries Science Center. Two drones traversed the Chukchi Sea, northwest of Alaska, to sample water carbon concentrations while another drone monitored pollock and fur seal populations in the Bering Strait. Researching along icy coasts was an ideal spot for the autonomous vessels, says Cross. “Ice is unpredictable, and you need a really heavy ship in order to safely navigate that area. Even though ships are one of the most powerful oceanographic tools that we have, it can be expensive,” she says. 

And when surveying easily spooks animals, keeping a low profile can be critical to getting accurate data. “Ships are noisy ... they turn up a lot of water and so what we’re noticing ... is that we scare less fish with the Saildrone. So we get a slightly different count of how many fish are in the water and what level or what depth of the water they’re hanging out at,” she says. 

The boats are so discreet that wildlife sometimes feel comfortable approaching them. Last summer, a fur seal hopped aboard one of the Saildrones in the Chukchi Sea and rode it for hours before hopping off into a phytoplankton bloom. “It could have been pure coincidence or it could have been like he was taking a cab, thinking, ‘I can smell that there’s food over there. You look like you’re headed in that direction. I’m going to go with you,’ ” Cross says. “Those are the kinds of things that we’re seeing now that we wouldn’t have had the opportunity to see before.” 

Saildrones aren’t just covering new ground; they’re raising new possibilities for oceanographic research. This month, two drones are expected to return from a seven-month excursion into the Pacific Ocean to collect climate data, including wind direction, air pressure, and ocean currents. The boats are being tested to determine their potential in supplementing NOAA’s network of Tropical Atmosphere Ocean buoys and moorings.

“We are integrating all of these different measurements ... to come up with the global maps of the best representation of what is actually out there,” says Meghan Cronin, lead researcher for the Ocean Climate Stations group at PMEL.

If the data the Saildrones bring back matches the buoy measuring system, the drones could help climate scientists better predict and prepare for the extreme weather conditions that El Niño brings. 

“The strength of a Saildrone is that it moves and it can do these adaptive surveys, and it can cross fronts and see how abrupt these fronts are,” says Dr. Cronin. When weather in the Pacific changes rapidly, the moorings, stationed nearly 1,000 miles apart, can only roughly render the shape of a moving front. 

The drones could enhance future climate modeling, but Cronin doesn’t foresee a future in which they are the only tool oceanographers use. 

“Each of these platforms has its own strength but also its weakness, and so you have to fill in some of the weaknesses with strengths of the other platforms,” she says.

That multiplatform experimentation is central to Block’s approach as she and her colleagues maneuver the White Shark Café. The Saildrones are just the first step in the team’s barrage of data-sampling devices. About 30 sharks are also wearing acoustic tags that send locational updates. Another autonomous device, known as a Slocum Glider, will travel up and down the water column and follow the sharks’ rapid diving. And a biochemical instrument called a nanopore processor will scour the water for DNA left behind by fish and other organisms.  

Seeing the sharks – many of whom scientists have given names like “Tiny,” “Heffalump,” and “Shawshark Redemption” – so far from where they’re normally spotted is a thrill. But the goal is to build a comprehensive vision of the subaquatic environment. “We’re going to be asking in the simplest form who is in the ecosystem,” she says.

As the technology progresses, the Saildrone will likely continue to adapt and fill scientific niches, says James Bellingham, director of the Center for Marine Robotics at the Woods Hole Oceanographic Institution in Woods Hole, Mass. 

“As a technologist I create one of these systems and I’m disappointed if the only thing they’re ever used for is the thing that I thought of when I built the robot,” he says.

But even with the Saildrones’ rapid advances, some design elements seem unlikely to change, at least for now. “It’s kind of interesting because we’ve known about powering things by wind for millennia,” says Dr. Bellingham. “In a way it’s one of these back-to-the-future things.”

On Wednesdays at 6:30 p.m., women from Winter Valley senior housing in the Boston suburb of Milton, Mass., gather around a table to chat, snack on baked goods, and crochet. Except these women aren’t making hats and scarves out of soft yarns. They’re creating sleeping mats for homeless people – out of recycled plastic bags.

This particular group of about a dozen women has been meeting almost every week for more than a year, converting bags into six-foot-long water-resistant mats. The finished mats are delivered to Pine Street Inn, a service center in Boston for homeless people. They’re spongier and more resistant than cardboard, helping to protect people from the effects of lying down on the cold, hard ground. So far, the Winter Valley women have delivered 16 mats.

The mats are “really helpful because they keep people off the concrete, and part of preventing frostbite is keeping people dry. That mitigates against cold weather injuries, so [they’re] lifesavers,” says Michael Andrick, director of outreach at Pine Street Inn.

Not the only mat-makers

The Winter Valley women are part of a larger mat-making project that began in 2016 with a church group in Union City, Tenn., and has since been adopted by groups from California to Iowa to Canada. It’s also been shared widely on Facebook, which is how Judy O’Brien, a Winter Valley resident fondly referred to as the “boss lady,” learned about it. The only problem: She didn’t know how to crochet. So she recruited friend and neighbor Edith Johansen to teach a few other women, and the Milton chapter was born. (Ms. Johansen, who holds a record by having completed five mats, has been temporarily sidelined by a hand injury, but still attends meetings to boost morale.)

The project has emerged at a time when more than half a million people in the United States are homeless. Although Boston’s homeless population is significantly smaller than those in other US cities – less than 1 percent of the Boston population is homeless – those who sleep outside in Boston endure brutal New England weather. The plastic mats are one way to provide a measure of comfort to the city’s homeless community, and it’s also giving the crocheters a sense of purpose.

“It’s kind of fun, and you meet all of your neighbors, and then you get to give back,” says Sheila McLelland as she works on her first mat. Despite not having crocheted for 30 years, Ms. McLelland deftly pulled and looped the material with ease. “I think that it’s nice, because when it’s cold out, [homeless people] don’t have to sleep on the cold ground.”

Pine Street Inn, which sweeps the streets on the coldest nights to bring people inside, enlists overnight teams to deliver the mats. Members of the homeless community have consistently expressed their gratitude for the mats, recognizing the crocheters for their hard work, Mr. Andrick says.

Each 120-row mat is made up of 500 to 600 bags and takes about a month to make. The bags are folded, cut, and looped to create “plarn,” or plastic yarn. The result is a unique, multicolored mat that can be easily rolled up and is light to carry. Attached to the mats are warning labels that caution against placing them on top of heating vents, where they could melt and catch on fire. (The labels were added after one of the crocheters accidentally left a mat next to a radiator for too long.)

While the mat-making project is ensuring that homeless people will be warmer as they sleep, it has also helped the women of Winter Valley get out of their apartments and meet new people.

“In the winter, the nights are long and you get tired of TV.... There’s only so much you can watch,” says Marie Butler as Ms. O’Brien brings out a tray of chocolate frosted cookies. “I enjoy the company. We get along well, all of us, because we’re all friends.”

Chitchat while crocheting

In fact, many of the women met each other and became friends through the project. As they crochet, they ask each other about their days, their family members, and whether they plan to attend a pancake breakfast the next morning.

When the women started crocheting, they asked for plastic bags on a Facebook group page for Milton residents. Now, the mat-making project is so well known in town that people drop off boxes of bags at Winter Valley and fill resident Lea Cullen’s car – which she leaves unlocked – with more bags.

“I will go to church [on Sundays], and by the time I come to drive back home, the back of my car is full of bags,” says Ms. Cullen with a shrug as the women around her break out in laughter. Cullen, who was the only woman engineer in her class at Northeastern University in the 1950s, doesn’t crochet herself but still enjoys watching her friends transform bags into mats.

Some of the bags that the women receive can’t be used because they’re ruined or made from a thicker kind of plastic that isn’t flexible enough to be crocheted, O’Brien says.

Whether or not the bags can be used for the mats, the women recycle almost everything they receive. And they show no signs of slowing down.

“I think [we’ll stop crocheting only] when they ban plastic bags,” says O’Brien with defiance.

AP Photo

Rohingya refugees rebuild their makeshift house, in preparation for the approaching monsoon season at the Kutupalong Rohingya refugee camp in Kutupalong, Bangladesh. Rohingya refugees who fled Myanmar during a brutal crackdown now face a new danger: rain. The annual monsoon will soon sweep through camps where some 700,000 Rohingya Muslims live in huts made of bamboo and plastic built along steep hills.

As befits its reputation for generosity, Canada is ranked in the top four of nations most accepting of migrants, according to a recent Gallup poll. As a share of population, its yearly immigration is three times that of the United States. This distinction may help explain why, as the host of a Group of Seven summit of major Western leaders, Canada has invited a most unlikely guest to the G7’s gathering in Quebec next month.

She is Sheikh Hasina, prime minister of Bangladesh. Her South Asian country is now coping with one of the world’s latest mass movements of refugees – the forced exodus of 700,000 Rohingya Muslims from mostly Buddhist Myanmar in a case of violent ethnic cleansing.

In addition, Canadian Prime Minister Justin Trudeau has put a related topic on the G7 agenda: Venezuela, also a recent source of mass migration. An estimated 5,000 Venezuelans a day are fleeing to neighboring countries, a result of mass hunger and poverty under a dictatorial regime. The number seeking asylum in the US jumped last year by 88 percent. And after a sham election in Venezuela last Sunday, the total number of migrants is expected to rise from 1.5 million to 2 million by year’s end.

Canada’s spotlight on these two countries is both welcome and well timed. According to the United Nations, the world is experiencing the highest number of displaced people on record, or about 40 million people, in places as diverse as Syria, South Sudan, Nigeria, Yemen, Venezuela, and Myanmar. Millions are fleeing for reasons just as diverse – political turmoil, mass poverty, or ethnic and religious conflict. In Myanmar, many Rohingya women fled just to avoid being raped.

While many Western countries, including the US, are increasing aid to refugees, the need for humanitarian assistance keeps rising even as the West’s ability to address the root causes of each crisis has diminished. Canada hopes to start a fix for all this by focusing the G7 summit on ways to influence the leaders of Myanmar and Venezuela.

Western democracies have a big stake in such a difficult task. Anti-immigrant feelings are disrupting their politics, reflected in Britain’s vote to leave the European Union, and the rise of extremist parties in many EU nations. Voters increasingly fear a loss of national sovereignty, local community, and rule of law.

Like many other global issues, mass migration needs to be on the agenda of world leaders. And it takes a generous country to put it there. As Canada knows, every refugee deserves a home, either back in their own country or in a welcoming foreign land.