Earth’s inner core may have temporarily stopped rotating relative to the mantle and surface, researchers report in the January 23 Nature Geoscience. Now, the direction of the inner core’s rotation may be reversing — part of what could be a roughly 70-year-long cycle that may influence the length of Earth’s days and its magnetic field — though some researchers are skeptical.
“We see strong evidence that the inner core has been rotating faster than the surface, [but] by around 2009 it nearly stopped,” says geophysicist Xiaodong Song of Peking University in Beijing. “Now it is gradually mov[ing] in the opposite direction.” Such a profound turnaround might sound bizarre, but Earth is volatile (SN: 1/13/21). Bore through the ever-shifting crust and you’ll enter the titanic mantle, where behemoth masses of rock flow viscously over spans of millions of years, sometimes upwelling to excoriate the overlying crust (SN: 1/11/17, SN: 3/2/17, SN: 2/4/21). Delve deeper and you’ll reach Earth’s liquid outer core. Here, circulating currents of molten metals conjure our planet’s magnetic field (SN: 9/4/15). And at the heart of that melt, you’ll find a revolving, solid metal ball about 70 percent as wide as the moon.
This is the inner core (SN: 1/28/19). Studies have suggested that this solid heart may rotate within the liquid outer core, compelled by the outer core’s magnetic torque. Researchers have also argued the mantle’s immense gravitational pull may apply an erratic brake on the inner core’s rotation, causing it to oscillate.
Evidence for the inner core’s fluctuating rotation first emerged in 1996. Geophysicist Paul Richards of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, N.Y., and Song, then also at Lamont-Doherty, reported that over a span of three decades, seismic waves from earthquakes took different amounts of time to traverse Earth’s solid heart.
The researchers inferred that the inner core rotates at a different speed than the mantle and crust, causing the time differences. The planet spins roughly 360 degrees in a day. Based on their calculations, the researchers estimated that the inner core, on average, rotates about 1 degree per year faster than the rest of Earth.
But other researchers have questioned that conclusion, some suggesting that the core spins slower than Song and Richards’ estimate or doesn’t spin differently at all.
In the new study, while analyzing global seismic data stretching back to the 1990s, Song and geophysicist Yi Yang — also at Peking University — made a surprising observation. Before 2009, seismic waves generated by sequences and pairs of repeating earthquakes — known as multiplets and doublets — traveled at different rates through the inner core. This indicated the waves from recurring quakes were crossing different parts of the inner core, and that the inner core was rotating at a different pace than the rest of Earth, aligning with Song’s previous research.
But around 2009, the differences in travel times vanished. That suggested the inner core had ceased rotating with respect to the mantle and crust, Yang says. After 2009, these differences returned, but the researchers inferred that the waves were crossing parts of the inner core that suggested it was now rotating in the opposite direction relative to the rest of Earth.
The researchers then pored over records of Alaskan earthquake doublets dating to 1964. While the inner core appeared to rotate steadily for most of that time, it seems to have made another reversal in rotation in the early 1970s, the researchers say.
Song and Yang infer that the inner core may oscillate with a roughly 70-year periodicity — switching directions every 35 years or so. Because the inner core is gravitationally linked to the mantle and magnetically linked to the outer core, the researchers say these oscillations could explain known 60- to 70-year variations in the length of Earth’s days and the behavior of the planet’s magnetic field. However, more work is needed to pin down what mechanisms might be responsible.
But not all researchers are on board. Yang and Song “identif[y] this recent 10-year period [that] has less activity than before, and I think that’s probably reliable,” says geophysicist John Vidale of the University of Southern California in Los Angeles, who was not involved in the research. But beyond that, Vidale says, things get contentious.
In 2022, he and a colleague reported that seismic waves from nuclear tests show the inner core may reverse its rotation every three years or so. Meanwhile, other researchers have proposed that the inner core isn’t moving at all. Instead, they say, changes to the shape of the inner core’s surface could explain the differences in wave travel times.
Future observations will probably help disentangle the discrepancies between these studies, Vidale says. For now, he’s unruffled by the purported chthonic standstill. “In all likelihood, it’s irrelevant to life on the surface, but we don’t actually know what’s happening,” he says. “It’s incumbent on us to figure it out.”
A new smartwatch app alerts users who are deaf or hard of hearing of nearby sounds, such as microwave beeps or car horns.
“The main motivation [for the app] came from my own experience, and conversations that my colleagues and I have had with deaf and hard of hearing people over several years,” says Dhruv Jain, who presented the system, called SoundWatch, at the virtual ASSETS conference on October 28.
Jain, who is hard of hearing, uses SoundWatch at home to avoid sleeping through a smoke alarm. “On a nature walk, it’ll tell me that there’s birds chirping, or there might be a waterfall nearby,” he says. “Those sounds make me feel more present and connected to the world.”
Sound awareness apps for smartphones exist. But Jain prefers the immediacy of sound notifications on his wrist, rather than in his pocket — and surveys of people who are deaf or hard of hearing show he’s not alone.
The SoundWatch app pairs an Android smartwatch and phone. The watch records ambient noises and sends that data to the phone for processing. When the phone detects a sound of interest, the smartwatch vibrates and displays a notification.
Jain, a computer scientist at the University of Washington in Seattle, and colleagues designed the app to identify 20 noises. In experiments, SoundWatch correctly identified those 20 sounds 81.2 percent of the time. When set to listen only for urgent noises — a fire alarm, door knock or alarm clock — the app was 97.6 percent accurate. Eight deaf and hard of hearing people who used SoundWatch around a university campus gave the app broadly favorable reviews, but noted that the app misclassified some sounds in noisy outdoor settings.
Jain and colleagues are now working on a version of SoundWatch that users can train to recognize new sounds, such as their own house alarm, using just a few recordings.
November is beginning to feel a lot like last March.
In Europe, where the coronavirus was largely under control for much of the summer and fall, cases are skyrocketing nearly everywhere. Twenty countries, including the United Kingdom and France, have shuttered restaurants, introduced curfews or generally urged people to stay at home, though most schools and universities are staying open for now.
Cases are surging across the United States, too, where more than 100,000 new infections are being reported each day. Already in November, more than half of states have set records for the most cases in a week, and in places such as Minnesota, Utah and Wisconsin, some hospitals are nearing capacity. In North Dakota, nearly 1 in every 14 people has already contracted the coronavirus, with 2,254 cases reported November 8 alone in a state of 762,000 people.
To make matters worse, “the virus is going into its sweet spot at a time that we’re exhausted by it,” says Jeffrey Shaman, an infectious diseases epidemiologist at the Columbia University Mailman School of Public Health in New York City. That sweet spot is indoors, where people are spending more time as the weather in the Northern Hemisphere turns colder — and where the virus can spread more easily.
Despite such a grave outlook, experts say it’s still not too late to turn the tide.
Shutting down borders, businesses and schools are among the most drastic measures to do that. Worries over economic consequences may hold governments back from issuing widespread stay-at-home orders this time around, though.
U.S. President-elect Joe Biden, who unveiled a COVID-19 advisory board November 9, has proposed a multipronged plan for controlling the pandemic, including nationwide mask mandates and expanded testing. But Biden won’t take office until January 20, and President Donald Trump has repeatedly downplayed the surge in cases.
While getting a COVID-19 vaccine — or vaccines — is closer than ever (SN: 11/9/20), most experts agree that vaccines probably won’t be available to everybody until late spring or early summer. That means getting through the winter will require falling back on the familiar public health tools of physical distancing, mask wearing, and testing and isolating infected people, Shaman says. But all of those measures fall short unless everyone is willing to follow the rules.
Living in this reality can be draining, acknowledges Aleksandra Zając, a doctor specializing in nuclear medicine in Warsaw. Doctors and patients alike are tired of not being able to leave their homes and having to wear a mask when they do, she says, but “as a doctor, I really see the need for all those restrictions.” People aren’t helpless against the virus, she says. “We still have some impact on what’s going on.” Zając devised a calculator to help people learn how much wearing masks and goggles, regularly washing their hands and keeping distance from others might help protect them. Alone, none of those measures is perfect, but doing them all together can boost protection, like layering slices of Swiss cheese so that holes in one slice are covered by another slice. The Swiss cheese idea is not new, but it’s still relevant for stacking public health measures, Zając says. It goes for individual actions, too.
“One individual cannot do much” beyond protecting themselves, Zając says, “but if we sum up all the individuals together and they all follow the rules, I truly believe we can control this pandemic.”
Scientists know much more about the virus than they did in March, and that knowledge can help make the most of all the public health tools at our disposal.
Mask up Dozens of studies have made it abundantly clear that wearing a mask is one of the most effective steps an individual can take to help curb the pandemic. Masks are especially crucial in lessening the risk of someone who doesn’t know they’re infected passing the virus to someone else (SN: 6/26/20).
Additionally, there’s a growing understanding among scientists that masks are good for the wearer too. The U.S. Centers for Disease Control and Prevention updated their scientific guidance on November 10 to acknowledge that cloth masks can reduce the number of infectious droplets inhaled by the wearer, which offers a degree of protection, especially when masks are multi-layered.
In a study published October 23 in Nature Medicine, scientists estimate that if 95 percent of people wore masks when outside their homes, nearly 130,000 deaths from COVID-19 might be averted in the United States between the end of September and the end of February 2021. If 85 percent of people wear masks, about 96,000 lives might be saved, the researchers calculate.
The debate over which kind of mask is best, however, has been spirited (SN: 8/12/20).
When it comes to ubiquitous cloth masks, only one randomized clinical trial in the world is testing their effectiveness in preventing COVID-19. That trial in Guinea-Bissau is giving all 66,000 expected participants advice about how to avoid respiratory illnesses. Half of those people will each also get two locally sewn cloth masks. The trial is expected to wrap up in November.
Some research on the prevention of other respiratory illnesses suggests that a cloth mask’s effectiveness depends on many factors, including wearing the mask properly over both the nose and mouth. Regular washing in hot water is also necessary, says Raina MacIntyre, a mask researcher at the University of New South Wales in Sydney. In 2015, she and colleagues published in BMJ Open results of a trial conducted in Hanoi, Vietnam. Roughly 1,600 health care workers at 15 hospitals were assigned to either wear a medical mask at all times during their shift, to wear a two-layer cloth mask or to follow the hospital’s standard practice, which may or may not involve wearing a mask. The results weren’t encouraging. At the end of the five-week study, people in the cloth mask group had the highest rate of respiratory infections, such as colds — even higher than the group that wasn’t regularly wearing masks. The researchers concluded that health care workers shouldn’t wear cloth masks and opt instead for medical masks.
The trial was very controversial, MacIntyre says, “because the message was that cloth masks could be dangerous. That caused a lot of angst during the pandemic. In March and April, I had a lot of health workers in the U.S. and Europe contacting me and saying, ‘The hospital has run out of respirators. Is it better I wear no mask than wear a cloth mask?’”
That prompted MacIntyre and colleagues to examine unpublished data from the trial. Both surgical and cloth masks get contaminated with respiratory viruses, the researchers found. But surgical masks are disposable. If people didn’t wash their reusable cloth masks every day, the masks became more and more contaminated.
“If you washed your cloth mask in a washing machine with hot water, you were just as protected as wearing a surgical mask,” MacIntyre says. But workers who hand-washed their masks had double the risk of infection of those wearing a medical mask, the researchers reported September 28 in BMJ Open. “The bottom line is, the washing is part of the protective effect of a cloth mask,” MacIntyre says. She recommends a daily wash in water at 60° to 90° Celsius, far hotter than anyone could stand to hand-wash. Shrinkage from hot water also tightens up pores in the mask, keeping the virus from slipping through easily.
Health care workers should also wear protective goggles to prevent rare cases of infection through the eye, MacIntyre says. But determining whether people going about their daily lives need goggles, face shields or other eye protection in addition to masks is a tricky bit of calculus, she says. “You have to look at community transmission rates. You have to look at where you’re actually going. Are you just going for a walk outside or are you going to a doctor’s surgery and are going to be sitting in an unventilated waiting room for two hours?”
The best most people can do is to take all the precautions they can, including avoiding large gatherings — especially indoors — wearing masks and keeping distance from people they don’t live with.
Fine-tuning lockdowns Early in the pandemic, lockdowns and social distancing measures (of varying severity) enacted in many countries largely worked. Staying at home starved the virus of transmission opportunities, preventing over 500 million infections in six hard-hit countries, according to some experts (SN: 6/9/20).
Circumstances are different now. “I don’t think we’ll lock down at that scale again,” says Michael Osterholm, an epidemiologist at the University of Minnesota in Minneapolis and a member of Biden’s task force. Now that scientists have a better understanding of transmission, blanket lockdowns may not be needed. Instead, restrictions could focus on crowded, poorly ventilated spaces like restaurants and bars.
If cases continue to grow exponentially, however, stricter lockdowns may be the only tool left to prevent hospitals from being overwhelmed. But such measures are increasingly less palatable to many Americans, Osterholm says. “What the public will accept is key. If they won’t comply, it doesn’t really matter what you recommend or how you recommend it.”
Limits of lockdowns Stay-at-home orders also don’t stop transmission within a household, where experts are learning that the virus can rapidly spread. In a sample of 101 homes with a positive coronavirus test, 53 percent of other people living in those homes became quickly infected, researchers reported in the Nov. 6 Morbidity and Mortality Weekly Report.
“We know that it’s really gatherings in close contact indoors that are riskiest,” says Alison Hill, an epidemiologist at Johns Hopkins University. “There’s no reason why if you’re in your own house or among family or friends to think that the disease can’t spread.” Isolating infected members of a household, wearing masks and improving ventilation can limit household transmission, she says.
And not everyone can stay home, which has contributed to inequities in who is getting sick in this pandemic.
In the United States, residents of poorer neighborhoods, often home to racial and ethnic minorities disproportionately affected by COVID-19 (SN:4/10/20), were less likely to stay at home during the early months of the pandemic than residents of richer neighborhoods. Cell phone mobility data suggest that this difference stems from work-related demands, according to a study published November 3 in Nature Human Behavior. Residents of the highest-income neighborhoods reduced days at work outside the home by 13.7 percent, compared with 6.6 percent for residents of lower-income neighborhoods, Jonathan Jay, a public health researcher at Boston University, and colleagues found.
Many residents of lower-income neighborhoods work jobs that can’t be done from home. But when there was a choice, people in these neighborhoods did limit their activities, Jay says. The data showed that people of all income groups reduced outings unrelated to work at roughly similar levels.
Policies like restricting evictions so people don’t fear losing their home if they miss work, expanding unemployment insurance and mandating paid sick leave could help these residents physically distance, Jay says.
Test and trace Lockdowns by themselves will not end the pandemic. They are only supposed to be temporary measures that buy time for local and state health departments to beef up other infection-control strategies. Crucial among these are testing and contact tracing, a tried-and-true public health intervention whereby contacts of positive cases are quickly identified and instructed to quarantine (SN: 4/29/20).
“Contact tracing is really key when you have a disease that’s as fast-spreading as COVID-19,” because it breaks crucial chains of transmission, says Martial Ndeffo, an infectious diseases researcher at Texas A&M University in College Station.
Contact tracing and isolation is most powerful when cases are identified early in the course of infection, their contacts are traced and informed of their exposure quickly, and those contacts comply with requests to quarantine. Such a system requires broadly available testing and lots of contact tracers to do the detective work. Otherwise, even with relatively small caseloads, contact tracing systems can’t keep up with a growing epidemic. At this point, most of the United States can’t keep up. In October, only three states and the District of Columbia had enough full-time contact tracers to deal with current caseloads, according to a survey conducted by NPR and the Johns Hopkins Center for Health Security. And as cases climb, even well-staffed systems could be overwhelmed.
“Given the number of cases in the U.S., it is unrealistic to think that most states have the resources and available staff to raise the army of contact tracers needed,” Ndeffo says. Biden’s COVID-19 response plan includes efforts to “mobilize at least 100,000 Americans across the country” to boost the contact tracing effort. Currently, there are just over 50,000 contact tracers nationwide.
Robust contact tracing systems work only if people comply with public health officials and share their contact history or quarantine if necessary. Yet only 58 percent of Americans would be likely to speak with a public health official who contacted them by phone or text message about the coronavirus outbreak, according to a Pew Research survey released October 30. “A substantial number of people do not comply with or provide adequate information needed for contact tracing to be effective,” Ndeffo says. Clearer and more consistent public health messaging could improve these numbers.
Time is of the essence It’s important to act quickly to introduce social distancing measures when case counts begin to surge, as they are now in the United States and Europe, Shaman says, because outbreaks grow at exponential rates. “Exponential growth leads to a tsunami-like effect; it gets worse the longer you wait on it.”
He and colleagues simulated what would have happened had states done exactly what they did at the beginning of the U.S. epidemic in March, only earlier. Enacting social distancing and stay-at-home orders on March 1 instead of March 8 would have headed off about 600,000 confirmed cases and 32,000 deaths. Acting two weeks earlier would have avoided more than 1 million cases and about 60,000 deaths nationwide, Shaman and colleagues reported November 6 in Science Advances.
No one can turn back the clock. But countries including Vietnam, Taiwan, Singapore, New Zealand and Australia have shown that acting aggressively can curb the spread of the virus. “Going forward, the longer you delay in acting on this virus the more damage it does,” both to people who are infected and to the economy, Shaman says.
For instance, at the end of September, 89 counties in Tennessee eased or removed social distancing restrictions. But as COVID-19 cases rose, traffic to bars and restaurants decreased, researchers from Vanderbilt University in Nashville report. Cell phone mobility data as of October 21 suggest that business dropped once restrictions were lifted and was 24 percent below where it was during the same time in 2019. Those findings suggest that infection rates, not restrictions, have a bigger effect on people’s choices, the researchers conclude.
“If you don’t control the virus,” Shaman says, “you’re not going to have an economy.”
The subatomic particles are built of smaller particles called quarks, which are bound together by a powerful interaction known as the strong force. New experiments seem to show that the quarks respond more than expected to an electric field pulling on them, physicist Nikolaos Sparveris and colleagues report October 19 in Nature. The result suggests that the strong force isn’t quite as strong as theory predicts.
It’s a finding at odds with the standard model of particle physics, which describes the particles and forces that combine to make up us and everything around us. The result has some physicists stumped about how to explain it — or whether to even try. “It is certainly puzzling for the physics of the strong interaction, if this thing persists,” says Sparveris, of Temple University in Philadelphia.
Such stretchiness has turned up in other labs’ experiments, but wasn’t as convincing, Sparveris says. The stretchiness that he and his colleagues measured was less extreme than in previous experiments, but also came with less experimental uncertainty. That increases the researchers’ confidence that protons are indeed stretchier than theory says they should be.
At the Thomas Jefferson National Accelerator Facility in Newport News, Va., the team probed protons by firing electrons at a target of ultracold liquid hydrogen. Electrons scattering off protons in the hydrogen revealed how the protons’ quarks respond to electric fields (SN: 9/13/22). The higher the electron energy, the deeper the researchers could see into the protons, and the more the electrons revealed about how the strong force works inside protons.
For the most part, the quarks moved as expected when electric interactions pulled the particles in opposite directions. But at one point, as the electron energy was ramped up, the quarks appeared to respond more strongly to an electric field than theory predicted they would.
But it only happened for a small range of electron energies, leading to a bump in a plot of the proton’s stretch.
“Usually, behaviors of these things are quite, let’s say, smooth and there are no bumps,” says physicist Vladimir Pascalutsa of the Johannes Gutenberg University Mainz in Germany.
Pascalutsa says he’s often eager to dive into puzzling problems, but the odd stretchiness of protons is too sketchy for him to put pencil to paper at this time. “You need to be very, very inventive to come up with a whole framework which somehow finds you a new effect” to explain the bump, he says. “I don’t want to kill the buzz, but yeah, I’m quite skeptical as a theorist that this thing is going to stay.”
It will take more experiments to get theorists like him excited about unusually stretchy protons, Pascalutsa says. He could get his wish if Sparveris’ hopes are fulfilled to try the experiment again with positrons, the antimatter version of electrons, scattered from protons instead.
A different type of experiment altogether might make stretchy protons more compelling, Pascalutsa says. A forthcoming study from the Paul Scherrer Institute in Villigen, Switzerland, could do the trick. It will use hydrogen atoms that have muons in place of the electrons that usually orbit atoms’ nuclei. Muons are about 200 times as heavy as electrons, and orbit much closer to the nucleus of an atom than do electrons — offering a closer look at the proton inside (SN: 10/5/17). The experiment would involve stimulating the “muonic hydrogen” with lasers rather than scattering other electrons or positrons from them.
“The precision in the muonic hydrogen experiments will be much higher than whatever can be achieved in scattering experiments,” Pascalutsa says. If the stretchiness turns up there as well, “then I would start to look at this right away.”
Across the United States, kids are prepping for back-to-school, or are already in classrooms, and parents are buckling up for another pandemic school year. Like me, many are trying to get a handle on what COVID-19 precautions to take. Updated guidance released last week by the U.S. Centers for Disease Control and Prevention hasn’t exactly helped. It may have made dealing with back-to-school more confusing — and could even spur new outbreaks.
Last November, my fifth grader had to quarantine at home for 10 days after a close contact tested positive. Now, the CDC has nixed the quarantine recommendation for people exposed to COVID-19. Today, our situation could look something like this: My COVID-exposed daughter would mask for 10 days, test on day five, and remain in school the whole time — only the infected child would isolate. That child would stay home for at least five days after a positive test. Then, if the child is fever-free and symptoms are improving, according to the new guidance, they could pop on a mask and hightail it back to class — no testing needed. That advice could mean more COVID-19 in classrooms. Scientists have shown that people can remain infectious after day five. So without testing for COVID-19, students and teachers won’t know if they’re bringing the disease back to school.
On the same day the CDC’s guidance came out, the U.S. Food and Drug Administration added yet another wrinkle. If you think you’ve been exposed to COVID-19 but test negative with an at-home COVID-19 antigen test, the FDA now recommends testing again … and again. Repeat testing over time cuts the chances you’ll miss an infection and unknowingly spread the virus, the FDA advised on August 11.
It’s hard to say how that advice jibes with the CDC’s new, more-relaxed guidelines. Even the agency has said its public guidance during the pandemic has been “confusing and overwhelming,” the New York Times reports. CDC director Rochelle Walensky is now planning a shake-up that could include restructuring the communications office as well as relying more on preliminary studies rather tha The CDC’s new guidance has sparked a range of reactions, many negative, among scientists, doctors, parents and teachers. In an informal Twitter poll of Science News followers, roughly 80 percent of the 353 respondents reported that the new CDC guidance made them feel confused, worried or angry and/or exasperated.
Now, it’s up to local school districts to decide what COVID-19 measures to take. “Just because guidance has changed does not mean COVID is gone,” Becky Pringle, president of the National Education Association labor union, said in a statement. Not by a long shot. The United States is currently averaging nearly 500 daily coronavirus deaths and more than 100,000 new cases a day, an almost certain undercount.
As my own children gear up for school, I wonder about COVID-19’s constantly shifting landscape. Like other families with school-aged children, we’ve bounced from virtual school to in-person mask mandates to mask-optional recommendations. And we still don’t know our district’s plans for the upcoming year. School starts in about a week.
There is reason for hope, though: We know what measures can slow COVID-19’s spread in schools. Masking is a big one. A preliminary study posted August 9 linked lifting school mask mandates in Boston-area K–12 schools with a rise in cases among students and staff. At Boston University, mandatory masking plus a vaccine mandate seemed to keep the virus in check in classrooms, scientists reported August 5 in JAMA Network Open. Testing can help, too. A computer analysis from England suggests that regularly rapid testing students can curb classroom transmission, scientists report August 10 in the Royal Society Open Science. But knowing what works is not the same as actually employing evidence-based measures in the classroom, says Anne Sosin, a public health researcher at Dartmouth College whose research focuses on COVID-19 and rural health equity. She has studied how pandemic policies have impacted schools in northern New England. “I worry that we simply have not seen the political leadership to ensure that all children and educators can safely participate in school.”
I spoke with Sosin about the CDC’s new guidance, and what kids and parents might expect heading into the new school year. Our conversation has been edited for length and clarity.
SN: What do you think of the updated guidance?
Sosin: I was very disappointed that the CDC did not adopt a test-to-exit-isolation recommendation.
What we’re going to see in schools are infected students and educators returning after five days still positive for COVID-19. Multiple studies have demonstrated that most people are infectious beyond five days. Not only is it highly likely that they’ll be seeding outbreaks. They’ll also be putting high-risk members of school communities in danger.
SN: What could the guidance mean for vulnerable kids?
Sosin: I think that vulnerable people are going to be in a very precarious situation. The guidance mentions the need to ensure protections for immunocompromised and other high-risk people but there’s a problem of implementation. Will schools actually implement those protections?
SN: Do scientists have a good handle on what protections can help?
Sosin: Definitely. We have really strong evidence showing that when layered mitigation strategies are in place, we can almost eliminate transmission in school settings. That means that we should have upgraded ventilation, lunchroom strategies [like taking kids outside to eat] and testing. And I continue to think that data-driven mask policies have a role to play. Not masking forever, but masking at times when we see an uptick in transmission.
SN: How could the new guidance affect different communities across the United States?
Sosin: Different communities have not only been impacted in dramatically different ways, but they’re also on unequal footing at this stage of the pandemic.
[If we compare white communities with communities of color], we see disparities in vaccination coverage and caregiver loss. Some communities have suffered enormous losses while others have really been untouched. Black children have lost caregivers at more than two times the rate of white children. For Indigenous children, the rate is 4.5 times as high. Those are sharp disparities.
Communities of color also have less access to testing, treatment and health care. I worry that if we don’t have a renewed focus on equity, then we’re just going to see an exacerbation of disparities that have existed throughout the pandemic.
SN: What advice do you have for parents as they head into the new school year?
Sosin: We all want as normal a school year as possible. Masking should be one of the tools we’re ready to employ to keep our kids in the classroom. In addition, we should be advocating that our schools invest in ventilation. Vaccination also represents a critical piece of the strategy.
We see such abysmal vaccination coverage among children. Less than 1 in 3 kids ages 5 to 11 are fully vaccinated. I think many parents no longer see it as important — there’s been this narrative that the pandemic is over. We need clear messaging that vaccination remains an important tool.
Now is a great time to plan back-to-school campaigns to vaccinate kids and to begin to prepare for the arrival of omicron-specific boosters in the fall.
Archaeologist Peter Bellwood’s academic odyssey wended from England to teaching posts halfway around the world, first in New Zealand and then in Australia. For more than 50 years, he has studied how humans settled islands from Southeast Asia to Polynesia.
So it’s fitting that his new book, a plain-English summary of what’s known and what’s not about the evolution of humans and our ancestors, emphasizes movement. In The Five-Million-Year Odyssey, Bellwood examines a parade of species in the human evolutionary family — he collectively refers to them as hominins, whereas some others (including Science News) use the term hominids (SN: 9/15/21) — and tracks their migrations across land and sea. He marshals evidence indicating that hominids in motion continually shifted the direction of biological and cultural evolution. Throughout his tour, Bellwood presents his own take on contested topics. But when available evidence leaves a debate unresolved, he says so. Consider the earliest hominids. Species from at least 4.4 million years ago or more whose hominid status is controversial, such as Ardipithecus ramidus, get a brief mention. Bellwood renders no verdict on whether those finds come from early hominids or ancient apes. He focuses instead on African australopithecines, a set of upright but partly apelike species thought to have included populations that evolved into members of our own genus, Homo, around 2.5 million to 3 million years ago. Bellwood hammers home the point that stone-tool making by the last australopithecines, the first Homo groups or both contributed to the evolution of bigger brains in our ancestors.
The action speeds up when Homo erectus becomes the first known hominid to leave Africa, roughly 2 million years ago. Questions remain, Bellwood writes, about how many such migrations occurred and whether this humanlike species reached distant islands such as Flores in Indonesia, perhaps giving rise to small hominids called hobbits, or Homo floresiensis (SN: 3/30/16). What’s clear is that H. erectus groups journeyed across mainland Asia and at least as far as the Indonesian island of Java.
Intercontinental migrations flourished after Homo sapiens debuted, around 300,000 years ago in Africa. Bellwood regards H. sapiens, Neandertals and Denisovans as distinct species that interbred in certain parts of Asia and Europe. He suggests that Neandertals disappeared around 40,000 years ago as they mated with members of more numerous H. sapiens populations, leaving a genetic legacy in people today. But he does not address an opposing argument that different Homo populations at this time, including Neandertals, were too closely related to have been separate species and that it was intermittent mating among these mobile groups that drove the evolution of present-day humans (SN: 6/5/21).
Bellwood gives considerable attention to the rise of food production and domestication in Europe and Asia after around 9,000 years ago. He builds on an argument, derived from his 2004 book First Farmers, that expanding populations of early cultivators migrated to new lands in such great numbers that they spread major language families with them. For instance, farmers in what’s now Turkey spread Indo-European languages into much of Europe sometime after roughly 8,000 years ago, Bellwood contends.
He rejects a recent alternative proposal, based on ancient DNA evidence, that horse-riding herders of Central Asia’s Yamnaya culture brought their traditions and Indo-European tongues to Europe around 5,000 years ago (SN: 11/15/17). Too few Yamnaya immigrated to impose a new language on European communities, Bellwood says. Similarly, he argues, ancient Eurasian conquerors, from Alexander the Great to Roman emperors, couldn’t get speakers of regional languages to adopt new ones spoken by their outnumbered military masters.
Bellwood rounds out his evolutionary odyssey with a reconstruction of how early agricultural populations expanded through East Asia and beyond, to Australia, a string of Pacific islands and the Americas. Between about 4,000 and 750 years ago, for instance, sea-faring farmers spread Austronesian languages from southern China and Taiwan to Madagascar in the west and Polynesia in the east. Precisely how they accomplished that remarkable feat remains a puzzle.
Disappointingly, Bellwood doesn’t weigh in on a recent archaeological argument that ancient societies were more flexible and complex than long assumed (SN: 11/9/21). On the plus side, his evolutionary odyssey moves along at a brisk pace and, like our ancestors, covers a lot of ground.
Sometimes a photo is literally a matter of life, death — and zombies.
This haunting image, winner of the 2022 BMC Ecology and Evolution photography competition, certainly fits that description. It captures the fruiting bodies of a parasitic fungus, emerging from the lifeless body of an infected fly in the Peruvian rainforest.
The fungus-infested fly was one of many images submitted to the contest from all over the world, aiming to showcase the beauty of the natural world and the challenges it faces. The journal revealed the winners August 18. Roberto García-Roa, a conservation photographer and evolutionary biologist at the University of Valencia in Spain, took the winning photo while visiting the Tambopata National Reserve, a protected habitat in the Amazon.
The fungus erupting from the fly belongs to the genus Ophiocordyceps, a diverse collection of parasitic fungi known as “zombie fungi,” due to their ability to infect insects and control their minds (SN: 7/17/19).
“There is still much to unravel about the diversity of these fungi as it is likely that each insect species infected succumbs to its own, specialized fungus,” says Charissa de Bekker, an expert in parasitic fungi at Utrecht University in the Netherlands.
First, spores of the fungus land on the ill-fated fly. So begins the manipulative endgame. The spores infiltrate the fly’s exoskeleton before infecting its body and eventually hijacking its mind. Once in control, the fungus uses its new powers of locomotion to relocate to a microclimate more suitable to its own growth — somewhere with the right temperature, light and moisture.
Fungus and fly then bide their time until the fly dies, becoming a food source for the fungus to consume. Fruiting bodies work their way out of the fly, filled with spores that are released into the air to continue the macabre cycle in a new, unsuspecting host. It is a “conquest shaped by thousands of years of evolution,” García-Roa said in a statement announcing the winners.
Research into the molecular aspects of fungal mind control is under way, De Bekker says, including in her own lab. “These fungi harbor all sorts of bioactive chemicals that we have yet to characterize and that could have novel medicinal and pest control applications.”
This is the first picture of an exoplanet from the James Webb Space Telescope.
“We’re actually measuring photons from the atmosphere of the planet itself,” says astronomer Sasha Hinkley of the University of Exeter in England. Seeing those particles of light, “to me, that’s very exciting.”
The planet is about seven times the mass of Jupiter and lies more than 100 times farther from its star than Earth sits from the sun, direct observations of exoplanet HIP 65426 b show. It’s also young, about 10 million or 20 million years old, compared with the more than 4-billion-year-old Earth, Hinkley and colleagues report in a study submitted August 31 at arXiv.org. Those three features — size, distance and youth — made HIP 65426 b relatively easy to see, and so a good planet to test JWST’s observing abilities. And the telescope has once again surpassed astronomers’ expectations (SN: 7/11/22).
“We’ve demonstrated really how powerful JWST is as an instrument for the direct imaging of exoplanets,” says exoplanet astronomer and coauthor Aarynn Carter of the University of California, Santa Cruz.
Astronomers have found more than 5,000 planets orbiting other stars (SN: 3/22/22). But almost all of those planets were detected indirectly, either by the planets tugging on the stars with their gravity or blocking starlight as they cross between the star and a telescope’s view.
To see a planet directly, astronomers have to block out the light from its star and let the planet’s own light shine, a tricky process. It’s been done before, but for only about 20 planets total (SN: 11/13/08; SN: 3/14/13; SN: 7/22/20).
“In every area of exoplanet discovery, nature has been very generous,” says MIT astrophysicist Sara Seager, who was not involved in the JWST discovery. “This is the one area where nature didn’t really come through.”
In 2017, astronomers discovered HIP 65426 b and took a direct image of it using an instrument on the Very Large Telescope in Chile. But because that telescope is on the ground, it can’t see all the light coming from the exoplanet. Earth’s atmosphere absorbs a lot of the planet’s infrared wavelengths — exactly the wavelengths JWST excels at observing. The space telescope observed the planet on July 17 and July 30, capturing its glow in four different infrared wavelengths.
“These are wavelengths of light that we’ve never ever seen exoplanets in before,” Hinkley says. “I’ve literally been waiting for this day for six years. It feels amazing.”
Pictures in these wavelengths will help reveal how planets formed and what their atmospheres are made of.
“Direct imaging is our future,” Seager says. “It’s amazing to see the Webb performing so well.”
While the team has not yet studied the atmosphere of HIP 65426 b in detail, it did report the first spectrum — a measurement of light in a range of wavelengths — of an object orbiting a different star. The spectrum allows a deeper look into the object’s chemistry and atmosphere, astronomer Brittany Miles of UC Santa Cruz and colleagues reported September 1 at arXiv.org.
That object is called VHS 1256 b. It’s as heavy as 20 Jupiters, so it may be more like a transition object between a planet and a star, called a brown dwarf, than a giant planet. JWST found evidence that the amounts of carbon monoxide and methane in the atmosphere of the orb are out of equilibrium. That means the atmosphere is getting mixed up, with winds or currents pulling molecules from lower depths to its top and vice versa. The telescope also saw signs of sand clouds, a common feature in brown dwarf atmospheres (SN: 7/8/22).
“This is probably a violent and turbulent atmosphere that is filled with clouds,” Hinkley says.
HIP 65426 b and VHS 1256 b are unlike anything we see in our solar system. They’re more than three times the distance of Uranus from their stars, which suggests they formed in a totally different way from more familiar planets. In future work, astronomers hope to use JWST to image smaller planets that sit closer to their stars.
“What we’d like to do is get down to study Earths, wouldn’t we? We’d really like to get that first image of an Earth orbiting another star,” Hinkley says. That’s probably out of JWST’s reach — Earth-sized planets are still too small see. But a Saturn? That may be something JWST could focus its sights on. Those three features — size, distance and youth — made HIP 65426 b relatively easy to see, and so a good planet to test JWST’s observing abilities. And the telescope has once again surpassed astronomers’ expectations (SN: 7/11/22).
“We’ve demonstrated really how powerful JWST is as an instrument for the direct imaging of exoplanets,” says exoplanet astronomer and coauthor Aarynn Carter of the University of California, Santa Cruz.
Astronomers have found more than 5,000 planets orbiting other stars (SN: 3/22/22). But almost all of those planets were detected indirectly, either by the planets tugging on the stars with their gravity or blocking starlight as they cross between the star and a telescope’s view.
To see a planet directly, astronomers have to block out the light from its star and let the planet’s own light shine, a tricky process. It’s been done before, but for only about 20 planets total (SN: 11/13/08; SN: 3/14/13; SN: 7/22/20).
“In every area of exoplanet discovery, nature has been very generous,” says MIT astrophysicist Sara Seager, who was not involved in the JWST discovery. “This is the one area where nature didn’t really come through.”
In 2017, astronomers discovered HIP 65426 b and took a direct image of it using an instrument on the Very Large Telescope in Chile. But because that telescope is on the ground, it can’t see all the light coming from the exoplanet. Earth’s atmosphere absorbs a lot of the planet’s infrared wavelengths — exactly the wavelengths JWST excels at observing. The space telescope observed the planet on July 17 and July 30, capturing its glow in four different infrared wavelengths.
“These are wavelengths of light that we’ve never ever seen exoplanets in before,” Hinkley says. “I’ve literally been waiting for this day for six years. It feels amazing.”
Pictures in these wavelengths will help reveal how planets formed and what their atmospheres are made of.
“Direct imaging is our future,” Seager says. “It’s amazing to see the Webb performing so well.”
While the team has not yet studied the atmosphere of HIP 65426 b in detail, it did report the first spectrum — a measurement of light in a range of wavelengths — of an object orbiting a different star. The spectrum allows a deeper look into the object’s chemistry and atmosphere, astronomer Brittany Miles of UC Santa Cruz and colleagues reported September 1 at arXiv.org.
That object is called VHS 1256 b. It’s as heavy as 20 Jupiters, so it may be more like a transition object between a planet and a star, called a brown dwarf, than a giant planet. JWST found evidence that the amounts of carbon monoxide and methane in the atmosphere of the orb are out of equilibrium. That means the atmosphere is getting mixed up, with winds or currents pulling molecules from lower depths to its top and vice versa. The telescope also saw signs of sand clouds, a common feature in brown dwarf atmospheres (SN: 7/8/22).
“This is probably a violent and turbulent atmosphere that is filled with clouds,” Hinkley says.
HIP 65426 b and VHS 1256 b are unlike anything we see in our solar system. They’re more than three times the distance of Uranus from their stars, which suggests they formed in a totally different way from more familiar planets. In future work, astronomers hope to use JWST to image smaller planets that sit closer to their stars.
“What we’d like to do is get down to study Earths, wouldn’t we? We’d really like to get that first image of an Earth orbiting another star,” Hinkley says. That’s probably out of JWST’s reach — Earth-sized planets are still too small see. But a Saturn? That may be something JWST could focus its sights on.
For some ant queens, the secret to long life might be a self-produced insulin blocker.
Ant queens are famously long-lived, even though they shouldn’t be. Generally, animals that put lots of energy into reproduction sacrifice some time off their life. But ant queens produce millions of eggs and live an extraordinarily long time compared with worker ants that don’t reproduce.
Now, researchers have shown how one ant species pulls off this anti-aging feat. When queens and wannabe queens of the species Harpegnathos saltator gear up to reproduce, a part of what’s called the insulin signaling pathway gets blocked, slowing aging, the researchers report in the Sept. 2 Science. That molecular pathway has long been implicated in aging in mammals, including humans. “There’s been a need to understand why queens, or reproductives, in social insects can live for so amazingly long,” says Marc Tatar, a biologist at Brown University in Providence, R.I., who was not involved with the study. Some ant species have queens that survive 30 times as long as their workers. Other social insects such as bees and termites also have long-lived queens.
In a rare behavior for ants, when a queen H. saltator dies, some female workers begin competing in duels for the chance to replace her (SN: 1/17/14). These hopeful royals develop ovaries, start laying eggs and transition into queenlike forms called gamergates. When a worker transitions to a gamergate, her life span becomes five times as long as it was. But if she doesn’t end up becoming queen and reverts back to a worker, her life span shortens again.
The researchers exploited this behavior to investigate the molecular underpinnings of anti-aging in these ants. H. saltator gamergates, it turns out, extend their life spans by taking advantage of a split in the insulin signaling pathway, the chain of chemical reactions that drive insulin’s effects on the body. One branch of this pathway is involved with reproduction, while the other is implicated in aging.
“Insulin comes with our life — [after] we eat, we have high insulin,” says Hua Yan, a biologist at the University of Florida in Gainesville. “But a constant high level of insulin is bad for longevity.”
Examining patterns of gene activity, Yan and colleagues found that gamergates have more active insulin genes than regular worker ants and, as a result, have increased metabolic activity and ovary development. But the secret sauce protecting the ants from the insulin’s aging effects appears to be a molecule called Imp-L2, which blocks the branch of the insulin pathway linked to aging, experiments showed. The branch involved in reproduction, however, remains active.
“What we don’t understand is how Imp-L2 can act on one aspect of the pathway and not on the other,” says study coauthor Claude Desplan, a developmental biologist at New York University.
These results represent a leap forward in our understanding of extreme social insect longevity, the researchers say, while also showcasing an anti-aging evolutionary adaptation that hasn’t been seen in the wild before.
For some ant queens, the secret to long life might be a self-produced insulin blocker.
Ant queens are famously long-lived, even though they shouldn’t be. Generally, animals that put lots of energy into reproduction sacrifice some time off their life. But ant queens produce millions of eggs and live an extraordinarily long time compared with worker ants that don’t reproduce.
Now, researchers have shown how one ant species pulls off this anti-aging feat. When queens and wannabe queens of the species Harpegnathos saltator gear up to reproduce, a part of what’s called the insulin signaling pathway gets blocked, slowing aging, the researchers report in the Sept. 2 Science. That molecular pathway has long been implicated in aging in mammals, including humans. “There’s been a need to understand why queens, or reproductives, in social insects can live for so amazingly long,” says Marc Tatar, a biologist at Brown University in Providence, R.I., who was not involved with the study. Some ant species have queens that survive 30 times as long as their workers. Other social insects such as bees and termites also have long-lived queens.
In a rare behavior for ants, when a queen H. saltator dies, some female workers begin competing in duels for the chance to replace her (SN: 1/17/14). These hopeful royals develop ovaries, start laying eggs and transition into queenlike forms called gamergates. When a worker transitions to a gamergate, her life span becomes five times as long as it was. But if she doesn’t end up becoming queen and reverts back to a worker, her life span shortens again.
The researchers exploited this behavior to investigate the molecular underpinnings of anti-aging in these ants. H. saltator gamergates, it turns out, extend their life spans by taking advantage of a split in the insulin signaling pathway, the chain of chemical reactions that drive insulin’s effects on the body. One branch of this pathway is involved with reproduction, while the other is implicated in aging.
“Insulin comes with our life — [after] we eat, we have high insulin,” says Hua Yan, a biologist at the University of Florida in Gainesville. “But a constant high level of insulin is bad for longevity.”
Examining patterns of gene activity, Yan and colleagues found that gamergates have more active insulin genes than regular worker ants and, as a result, have increased metabolic activity and ovary development. But the secret sauce protecting the ants from the insulin’s aging effects appears to be a molecule called Imp-L2, which blocks the branch of the insulin pathway linked to aging, experiments showed. The branch involved in reproduction, however, remains active.
“What we don’t understand is how Imp-L2 can act on one aspect of the pathway and not on the other,” says study coauthor Claude Desplan, a developmental biologist at New York University.
These results represent a leap forward in our understanding of extreme social insect longevity, the researchers say, while also showcasing an anti-aging evolutionary adaptation that hasn’t been seen in the wild before.
The Milky Way: An Autobiography of Our Galaxy takes a tour of our home in the cosmos from an unexpected perspective. Astrophysicist and folklorist Moiya McTier presents herself not as the author, but as the lucky human vessel through which the Milky Way has chosen to tell its story. Then she lets the galaxy take it away, with humor, heart and a huge dose of snark.
The book alternates chapters between science and mythology, reflecting McTier’s dual specialties (her bio says she was the first student in Harvard University’s history to study both). “Many of you don’t realize this, but myths were some of your species’ first attempt at scientific inquiry,” the Milky Way tells us.
The Milky Way is telling its story now because it’s sick of being ignored. Once upon a time, humans looked to the glittering smudge of stars in the sky for insight into when to plant crops or avoid floods. We told stories about the Milky Way’s importance in the origin and fate of the world.
Our galaxy ate it up: For an entity that spends most of its time ripping up smaller galaxies and watching its own stars die, “your stories made me feel loved and needed and, perhaps for the first time in my long existence, more helpful than I was ruinous.” But in the last few centuries, technology and light pollution have pulled humankind away. “At first, I thought it was just a phase,” the Milky Way says. “Then I remembered … that several hundred years is actually a long time for humans.” So the Milky Way decided to remind us why it’s so important. Its autobiography covers big-picture scientific questions about galaxies, like where they come from (“When a gas cloud loves itself very much,” the Milky Way explains, “it hugs itself extra tight, and after a few hundred million years, a baby galaxy is born. Leave the storks out of it, please.”). It also gets into what galaxies are made of, how they interact with other galaxies, and how they live and die. The book then zooms out to cover the origins and possible ends of the universe, mysteries like dark matter and dark energy, and even humankind’s search for other intelligent life (SN: 8/4/20).
The author takes pains to explain scientific jargon and the technical tools that astronomers use to study the sky. A lot of popular astronomy writing glosses over how astronomers think about cosmic distance or exactly what a spectrum is, but not this book. If you’ve ever been curious about these insider details, The Milky Way has you covered.
McTier’s version of our home galaxy is heavily anthropomorphized. The Milky Way is brash, vain and arrogant in a way that may hide a secret insecurity. Its central black hole is characterized as the physical embodiment of the galaxy’s shame and regrets, a source of deep existential angst. And its relationship with the Andromeda galaxy is like a long-term, long-distance romance, with each galaxy sending stars back and forth as love notes until the two can eventually merge (SN: 3/05/21).
This could have felt gimmicky. But McTier’s efforts to make the metaphors work while keeping the science accurate and up-to-date made the premise endearing and entertaining.
I laughed twice on Page 1. I learned a new word on Page 2. I dog-eared the endnotes early on because it became instantly clear I would want to read every one. I read this book while traveling in rural upstate New York, where the sky is much clearer than at my home outside of Boston. The Milky Way reminded me to look up and appreciate my home in the universe, just like its narrator wanted.
