It turns out that certain behaviors in domestic cats could be telltale signs that an interaction is friendly, aggressive or something in between, researchers report January 26 in Scientific Reports.
“It is a question we hear a lot from cat owners,” says cat behavior expert Mikel Delgado of Feline Minds, a cat behavior consulting company in Sacramento, Calif., who was not involved in the study. “So I was excited to see that researchers are taking on this topic.” Scientists have studied cats’ social relationships — both with other cats and humans — but it can be tricky to tell whether two cats are playing or fighting, says veterinarian and cat behavior researcher Noema Gajdoš-Kmecová of the University of Veterinary Medicine and Pharmacy in Košice, Slovakia (SN: 9/23/19).
Sometimes cat owners miss the signs of a tense relationship because they think their pets are just playing, which can lead to stress and illness in the animals, she says. Other times, owners rehome their cats after incorrectly assuming their pets are fighting.
To assess and categorize interactions, Gajdoš-Kmecová and colleagues watched about 100 videos of different cats interacting in pairs. After viewing around one-third of the videos, Gajdoš-Kmecová identified six types of behaviors, including wrestling and staying still. She then watched all of the videos and noted how often each cat exhibited one of the specified behaviors, and for how long. By running statistical analyses on the behaviors, she pinpointed three types of interactions between the cat pairs: playful, aggressive and intermediate.
To confirm the outcome, other members of the team also watched the videos and classified each interaction between felines.
Some clear connections emerged. Quietly wrestling, for instance, suggested playtime, whereas chasing and vocalizations, like growling, hissing or gurgling, implied aggressive encounters.
Intermediate interactions had elements of both playful and aggressive encounters, but especially included prolonged activity of one cat toward the other, such as pouncing on or grooming its fellow feline. These in-between encounters could hint that one cat wants to keep playing while the other doesn’t, with the more playful cat gently nudging to see if its partner wants to continue, the authors say. This work provides initial insights into cat interactions, Gajdoš-Kmecová says, but it’s just the start. In the future, she plans to study more subtle behaviors, like ear twitches and tail swishes. Both Gajdoš-Kmecová and Delgado also stress that one contentious encounter doesn’t necessarily signal a cat-astrophic relationship.
“This is not just about one interaction,” Gajdoš-Kmecová says. Owners “really should look into the different, multiple interactions in multiple periods of life of the cats and then put it into context.”
The night sky has been brightening faster than researchers realized, thanks to the use of artificial lights at night. A study of more than 50,000 observations of stars by citizen scientists reveals that the night sky grew about 10 percent brighter, on average, every year from 2011 to 2022.
In other words, a baby born in a region where roughly 250 stars were visible every night would see only 100 stars on their 18th birthday, researchers report in the Jan. 20 Science. The perils of light pollution go far beyond not being able to see as many stars. Too much brightness at night can harm people’s health, send migrating birds flying into buildings, disrupt food webs by drawing pollinating insects toward lights instead of plants and may even interrupt fireflies trying to have sex (SN: 8/2/17; SN: 8/12/15).
“In a way, this is a call to action,” says astronomer Connie Walker of the National Optical-Infrared Astronomy Research Laboratory in Tucson. “People should consider that this does have an impact on our lives. It’s not just astronomy. It impacts our health. It impacts other animals who cannot speak for themselves.”
Walker works with the Globe at Night campaign, which began in the mid-2000s as an outreach project to connect students in Arizona and Chile and now has thousands of participants worldwide. Contributors compare the stars they can see with maps of what stars would be visible at different levels of light pollution, and enter the results on an app.
“I’d been quite skeptical of Globe at Night” as a tool for precision research, admits physicist Christopher Kyba of the GFZ German Research Centre for Geosciences in Potsdam. But the power is in the sheer numbers: Kyba and colleagues analyzed 51,351 individual data points collected from 2011 to 2022.
“The individual data are not precise, but there’s a whole lot of them,” he says. “This Globe at Night project is not just a game; it’s really useful data. And the more people participate, the more powerful it gets.”
Those data, combined with a global atlas of sky luminance published in 2016, allowed the team to conclude that the night sky’s brightness increased by an average 9.6 percent per year from 2011 to 2022 (SN: 6/10/16).
Most of that increase was missed by satellites that collect brightness data across the globe. Those measurements saw just a 2 percent increase in brightness per year over the last decade. There are several reasons for that, Kyba says. Since the early 2010s, many outdoor lights have switched from high-pressure sodium lightbulbs to LEDs. LEDs are more energy efficient, which has environmental benefits and cost savings.
But LEDs also emit more short-wavelength blue light, which scatters off particles in the atmosphere more than sodium bulbs’ orange light, creating more sky glow. Existing satellites are not sensitive to blue wavelengths, so they underestimate the light pollution coming from LEDs. And satellites may miss light that shines toward the horizon, such as light emitted by a sign or from a window, rather than straight up or down.
Astronomer and light pollution researcher John Barentine was not surprised that satellites underestimated the problem. But “I was still surprised by how much of an underestimate it was,” he says. “This paper is confirming that we’ve been undercounting light pollution in the world.”
The good news is that no major technological breakthroughs are needed to help fix the problem. Scientists and policy makers just need to convince people to change how they use light at night — easier said than done.
“People sometimes say light pollution is the easiest pollution to solve, because you just have to turn a switch and it goes away,” Kyba says. “That’s true. But it’s ignoring the social problem — that this overall problem of light pollution is made by billions of individual decisions.”
Some simple solutions include dimming or turning off lights overnight, especially floodlighting or lights in empty parking lots.
Kyba shared a story about a church in Slovenia that switched from four 400-watt floodlights to a single 58-watt LED, shining behind a cutout of the church to focus the light on its facade. The result was a 96 percent reduction in energy use and much less wasted light , Kyba reported in the International Journal of Sustainable Lighting in 2018. The church was still lit up, but the grass, trees and sky around it remained dark.
“If it was possible to replicate that story over and over again throughout our society, it would suggest you could really drastically reduce the light in the sky, still have a lit environment and have better vision and consume a lot less energy,” he says. “This is kind of the dream.”
Barentine, who leads a private dark-sky consulting firm, thinks widespread awareness of the problem — and subsequent action — could be imminent. For comparison, he points to a highly publicized oil slick fire on the Cuyahoga River, outside of Cleveland, in 1969 that fueled the environmental movement of the 1960s and ’70s, and prompted the U.S. Congress to pass the Clean Water Act.
“I think we’re on the precipice, maybe, of having the river-on-fire moment for light pollution,” he says.
The Arctic today is a hostile place for most primates. But a series of fossils found since the 1970s suggest that wasn’t always the case.
Dozens of fossilized teeth and jaw bones unearthed in northern Canada belonged to two species of early primates — or at least close relatives of primates — that lived in the Arctic around 52 million years ago, researchers report January 25 in PLOS ONE. These remains are the first primate-like fossils ever discovered in the Arctic and tell of a groundhog-sized animal that may have skittered across trees in a swamp that once existed above the Arctic Circle. The Arctic was significantly warmer during that time. But creatures still had to adapt to extreme conditions such as long winter months without sunlight. These challenges make the presence of primate-like creatures in the Arctic “incredibly surprising,” says coauthor Chris Beard, a paleontologist at the University of Kansas in Lawrence. “No other primate or primate relative has ever been found this far north so far.”
Between frigid temperatures, limited plant growth and months of perpetual darkness, living in the modern Arctic isn’t easy. This is especially true for primates, which evolved from small, tree-dwelling creatures that largely fed on fruit (SN: 6/5/13). To this day, most primates — humans and few other outliers like Japan’s snow monkeys excepted — tend to stick to tropical and subtropical forests, largely found around the equator.
But these forests haven’t always been confined to their present location. During the early Eocene Epoch, which started around 56 million years ago, the planet underwent a period of intense warming that allowed forests and their warm-loving residents to expand northward (SN: 11/3/15).
Scientists know about this early Arctic climate in part because of decades of paleontological work on Ellesmere Island in northern Canada. These digs revealed that the area was once dominated by swamps not unlike those found in the southeastern United States today. This ancient, warm, wet Arctic environment was home to a wide array of heat-loving animals, including giant tapirs and crocodile relatives. For the new study, Beard and his colleagues examined dozens of teeth and jawbone fossils found in the area, concluding that they belong to two species, Ignacius mckennai and Ignacius dawsonae. These two species belonged to a now-extinct genus of small mammals that was widespread across North America during the Eocene. The Arctic variants probably made their way north as the planet warmed, taking advantage of the new habitat opening up near the poles.
Scientists have long debated whether this lineage can be considered true primates or whether they were simply close relatives. Regardless, it’s still “really weird and unexpected” to find primates or their relatives in the area, says Mary Silcox, a vertebrate paleontologist at the University of Toronto Scarborough.
For one thing, Ellesmere Island was already north of the Arctic Circle 52 million years ago. So while conditions may have been warmer and wetter, the swamp was plunged into continuous darkness during the winter months.
Newly arrived Ignacius would have had to adapt to these conditions. Unlike their southern kin, the Arctic Ignacius had unusually strong jaws and teeth suited to eating hard foods, the researchers found. This may have helped these early primates feed on nuts and seeds over the winter, when fruit wasn’t as readily available.
This research can shed light on how animals can adapt to live in extreme conditions. “Ellesmere Island is arguably the best deep time analog for a mild, ice-free Arctic,” says Jaelyn Eberle, a vertebrate paleontologist at the University of Colorado Boulder.
Studying how plants and animals adapted to this remarkable period in Arctic history, Beard says, could offer clues to the Arctic’s future residents.
Roughly 3,000 light-years from Earth sits one of the most complex and least understood nebulae, a whirling landscape of gas and dust left in the wake of a star’s death throes. A new computer visualization reveals the 3-D structure of the Cat’s Eye nebula and hints at how not one, but a pair of dying stars sculpted its complexity.
The digital reconstruction, based on images from the Hubble Space Telescope, reveals two symmetric rings around the nebula’s edges. The rings were probably formed by a spinning jet of charged gas that was launched from two stars in the nebula’s center, Ryan Clairmont and colleagues report in the October Monthly Notices of the Royal Astronomical Society.
“I realized there hasn’t been a comprehensive study of the structure of the nebula since the early ’90s,” says Clairmont, an undergraduate at Stanford University. Last year, while a high school student in San Diego, he reached out to a couple of astrophysicists at a scientific imaging company called Ilumbra who had written software to reconstruct the 3-D structure of astronomical objects.
The team combined Hubble images with ground-based observations of light in several wavelengths, which revealed the motions of the nebula’s gas. Figuring out which parts were moving toward and away from Earth helped reveal its 3-D structure.
The team identified two partial rings to either side of the nebula’s center. The rings’ symmetry and unfinished nature suggest they are the remains of a plasma jet launched from the heart of the nebula, then snuffed out before it could complete a full circle. Such jets are usually formed through an interaction between two stars orbiting one another, says Ilumbra partner Wolfgang Steffen, who is based in Kaiserslautern, Germany.
The work won Clairmont a prize at the 2021 International Science and Engineering Fair, an annual competition run by the Society for Science, which publishes Science News. Steffen was skeptical about the tight deadline — when Clairmont reached out, he had just two months to complete the project.
“I said that’s impossible! Not even Ph.D. students or anybody has tried that before,” Steffen says. “He did it brilliantly. He pulled it all off and more than we expected.”
Body changes at the brink of adulthood can get awkward in humans, but at least our eyes don’t pop out of our heads on stalks longer than our legs.
High-rise eyes, however, give macho pizzazz to the adult male Pelmatops fruit fly. In one of the stalkier species, P. tangliangi, the eyes-up transformation takes only about 50 minutes, a new study reports. Once stretched, the skinny eyestalks darken and harden, keeping the eyes stuck out like selfie sticks for the rest of the fly’s life. The details of P. tangliangi’s eye lift come from the first published photo sequence of their ocular blossoming, which appears in the September Annals of the Entomological Society of America. Biologists have known that eyestalks evolved in eight different fly families. Yet Pelmatops flies have gotten so little scientific attention that a lot of their basic biology has been a string of question marks.
Video images show the eyestalks curl and rise irregularly. Yet “they are not flopping around while partly inflated,” says Xiaolin Chen, an entomologist and evolutionary biologist at the Chinese Academy of Sciences in Beijing. “They seem slightly stiff, but still flexible enough.”
Females of the species may raise shorter eyestalks too — if Chen and her colleagues have found the right females. Chen suspects that what are now named as two species, based on the few specimens available, may just be two sexes of the same species. The new paper describes a male P. tangliangi mating with a female known by a different species name. Her stalks aren’t as magnificent as his, but she has some.
While the headgear can burden a flying insect, long eyestalks may give flies some swagger. These Pelmatops and other kinds of stalk-eyed flies face off, eyestalk to eyestalk, with uppity intruders. There’s no knocking and locking stalks in fierce fly disputes though. Any pushing and shoving, Chen says, is “done with other body parts.”
Extreme eyes may also have other benefits. In the wild, Chen finds these fruit flies on long stems of Rubus berry brambles. The eyes naturally periscope outward and upward, allowing the flies to spot danger while the body stays hidden in the greenery.
One hundred years ago, archaeologist Howard Carter stumbled across the tomb of ancient Egypt’s King Tutankhamun. Carter’s life was never the same. Neither was the young pharaoh’s afterlife.
Newspapers around the world immediately ran stories about Carter’s discovery of a long-lost pharaoh’s grave and the wonders it might contain, propelling the abrasive Englishman to worldwide acclaim. A boy king once consigned to ancient obscurity became the most famous of pharaohs (SN: 12/18/76).
It all started on November 4, 1922, when excavators led by Carter discovered a step cut into the valley floor of a largely unexplored part of Egypt’s Valley of the Kings. By November 23, the team had uncovered stairs leading down to a door. A hieroglyphic seal on the door identified what lay beyond: King Tutankhamun’s tomb. Tutankhamun assumed power around 1334 B.C., when he was about 10 years old. His reign lasted nearly a decade until his untimely demise. Although a minor figure among Egyptian pharaohs, Tutankhamun is one of the few whose richly appointed burial place was found largely intact.
An unusually meticulous excavator for his time, Carter organized a 10-year project to document, conserve and remove more than 6,000 items from Tutankhamun’s four-chambered tomb. While some objects, like Tut’s gold burial mask, are now iconic, many have been in storage and out of sight for decades. But that’s about to change. About 5,400 of Tutankhamun’s well-preserved tomb furnishings are slated to soon go on display when the new Grand Egyptian Museum, near the Pyramids of Giza, opens.
“The [Tut] burial hoard is something very unique,” Shirin Frangoul-Brückner, managing director of Atelier Brückner in Stuttgart, Germany, the firm that designed the museum’s Tutankhamun Gallery, said in an interview released by her company. Among other items, the exhibit will include the gold burial mask, musical instruments, hunting equipment, jewelry and six chariots.
Even as more of Tut’s story is poised to come to light, here are four things to know on the 100th anniversary of his tomb’s discovery.
Tut may not have been frail. Tutankhamun has a reputation as a fragile young man who limped on a clubfoot. Some researchers suspect a weakened immune system set him up for an early death.
But “recent research suggests it’s wrong to portray Tut as a fragile pharaoh,” says Egyptologist and mummy researcher Bob Brier, who is an expert on King Tut. His new book Tutankhamun and the Tomb That Changed the World chronicles how 100 years of research have shaped both Tut’s story and archaeology itself.
Clues from Tutankhamun’s mummy and tomb items boost his physical standing, says Brier, of Long Island University in Brookville, N.Y. The young pharaoh might even have participated in warfare.
Military chariots, leather armor and archery equipment buried with Tutankhamun show that he wanted to be viewed as a hunter and a warrior, Brier says. Inscribed blocks from Tutankhamun’s temple, which were reused in later building projects before researchers identified them, portray the pharaoh leading charioteers in undated battles.
If more blocks turn up showing battle scenes marked with dates, it would suggest Tutankhamun probably participated in those conflicts, Brier says. Pharaohs typically recorded dates of actual battles depicted in their temples, though inscribed scenes may have exaggerated their heroism.
The frail story line has been built in part on the potential discovery of a deformity in Tut’s left foot, along with 130 walking sticks found in his tomb. But ancient Egyptian officials were often depicted with walking sticks as signs of authority, not infirmity, Brier says. And researchers’ opinions vary about whether images of Tut’s bones reveal serious deformities.
X-rays of the recovered mummy from the 1960s show no signs of a misshapen ankle that would have caused a limp. Neither did CT images examined in 2005 by the Egyptian Mummy Project, headed by Egyptologist and former Egyptian Minister of Antiquities Zahi Hawass.
Then a 2009 reexamination of the CT images by the same researchers indicated that Tutankhamun had a left-foot deformity generally associated with walking on the ankle or the side of the foot, the team reported. The team’s radiologist, Sahar Saleem of Egypt’s Cairo University, says the CT images show that Tutankhamun experienced a mild left clubfoot, bone tissue death at the ends of two long bones that connect to the second and third left toes and a missing bone in the second left toe. Those foot problems would have “caused the king pain when he walked or pressed his weight on his foot, and the clubfoot must have caused limping,” Saleem says. So a labored gait, rather than an appeal to royal authority, could explain the many walking sticks placed in Tutankhamun’s tomb, she says.
Brier, however, doubts that scenario. Tutankhamun’s legs appear to be symmetrical in the CT images, he says, indicating that any left foot deformity was too mild to cause the pharaoh regularly to put excess weight on his right side while walking.
Whether or not the boy king limped through life, the discovery and study of his mummy made it clear that he died around age 19, on the cusp of adulthood. Yet Tut’s cause of death still proves elusive.
In a 2010 analysis of DNA extracted from the pharaoh’s mummy, Hawass and colleagues contended that malaria, as well as the tissue-destroying bone disorder cited by Saleem from the CT images, hastened Tutankhamun’s death. But other researchers, including Brier, disagree with that conclusion. Further ancient DNA studies using powerful new tools for extracting and testing genetic material from the mummy could help solve that mystery.
Tut’s initial obscurity led to his fame. After Tutankhamun’s death, ancient Egyptian officials did their best to erase historical references to him. His reign was rubbed out because his father, Akhenaten, was a “heretic king” who alienated his own people by banishing the worship of all Egyptian gods save for one.
“Akhenaten is the first monotheist recorded in history,” Brier says. Ordinary Egyptians who had prayed to hundreds of gods suddenly could worship only Aten, a sun god formerly regarded as a minor deity.
Meeting intense resistance to his banning of cherished religious practices, Akhenaten — who named himself after Aten — moved to an isolated city, Amarna, where he lived with his wife Nefertiti, six girls, one boy and around 20,000 followers. After Akhenaten died, residents of the desert outpost returned to their former homes. Egyptians reclaimed their old-time religion. Akhenaten’s son, Tutankhaten — also originally named after Aten — became king, and his name was changed to Tutankhamun in honor of Amun, the most powerful of the Egyptian gods at the time.
Later pharaohs omitted from written records any mentions of Akhenaten and Tutankhamun. Tut’s tomb was treated just as dismissively. Huts of craftsmen working on the tomb of King Ramses VI nearly 200 years after Tut’s death were built over the stairway leading down to Tutankhamun’s nearby, far smaller tomb. Limestone chips from the construction littered the site. The huts remained in place until Carter showed up. While Carter found evidence that the boy king’s tomb had been entered twice after it was sealed, whoever had broken in took no major objects.
“Tutankhamun’s ignominy and insignificance saved him” from tomb robbers, says UCLA Egyptologist Kara Cooney.
Tut’s tomb was a rushed job. Pharaohs usually prepared their tombs over decades, building many rooms to hold treasures and extravagant coffins. Egyptian traditions required the placement of a mummified body in a tomb about 70 days after death. That amount of time may have allowed a mummy to dry out sufficiently while retaining enough moisture to fold the arms across the body inside a coffin, Brier suspects.
Because Tutankhamun died prematurely, he had no time for extended tomb preparations. And the 70-day burial tradition gave craftsmen little time to finish crucial tomb items, many of which required a year or more to make. Those objects include a carved stone sarcophagus that encased three nested coffins, four shrines, hundreds of servant statues, a gold mask, chariots, jewelry, beds, chairs and an alabaster chest that contained four miniature gold coffins for Tutankhamun’s internal organs removed during mummification.
Evidence points to workers repurposing many objects from other people’s tombs for Tutankhamun. Even then, time ran out.
Consider the sarcophagus. Two of four goddesses on the stone container lack fully carved jewelry. Workers painted missing jewelry parts. Carved pillars on the sarcophagus are also unfinished.
Tutankhamun’s granite sarcophagus lid, a mismatch for the quartzite bottom, provides another clue to workers’ frenzied efforts. Something must have happened to the original quartzite lid, so workers carved a new lid from available granite and painted it to look like quartzite, Brier says.
Repairs on the new lid indicate that it broke in half during the carving process. “Tutankhamun was buried with a cracked, mismatched sarcophagus lid,” Brier says.
Tutankhamun’s sarcophagus may originally have been made for Smenkare, a mysterious individual who some researchers identify as the boy king’s half brother. Little is known about Smenkare, who possibly reigned for about a year after Akhenaten’s death, just before Tutankhamun, Brier says. But Smenkare’s tomb has not been found, leaving the sarcophagus puzzle unsolved.
Objects including the young king’s throne, three nested coffins and the shrine and tiny coffins for his internal organs also contain evidence of having originally belonged to someone else before being modified for reuse, says Harvard University archaeologist Peter Der Manuelian. Even Tutankhamun’s tomb may not be what it appears. Egyptologist Nicholas Reeves of the University of Arizona Egyptian Expedition in Tucson has argued since 2015 that the boy king’s burial place was intended for Nefertiti. He argues that Nefertiti briefly succeeded Akhenaten as Egypt’s ruler and was the one given the title Smenkare.
No one has found Nefertiti’s tomb yet. But Reeves predicts that one wall of Tutankhamun’s burial chamber blocks access to a larger tomb where Nefertiti lies. Painted scenes and writing on that wall depict Tutankhamun performing a ritual on Nefertiti’s mummy, he asserts. And the gridded structure of those paintings was used by Egyptian artists years before Tutankhamun’s burial but not at the time of his interment.
But four of five remote sensing studies conducted inside Tutankhamun’s tomb have found no evidence of a hidden tomb. Nefertiti, like Smenkare, remains a mystery.
Tut’s tomb changed archaeology and the antiquities trade. Carter’s stunning discovery occurred as Egyptians were protesting British colonial rule and helped fuel that movement. Among the actions that enraged Egyptian officials: Carter and his financial backer, a wealthy British aristocrat named Lord Carnarvon, sold exclusive newspaper coverage of the excavation to The Times of London. Things got so bad that Egypt’s government locked Carter out of the tomb for nearly a year, starting in early 1924.
Egyptian nationalists wanted political independence — and an end to decades of foreign adventurers bringing ancient Egyptian finds back to their home countries. Tutankhamun’s resurrected tomb pushed Egyptian authorities toward enacting laws and policies that helped to end the British colonial state and reduce the flow of antiquities out of Egypt, Brier says, though it took decades. Egypt became a nation totally independent of England in 1953. A 1983 law decreed that antiquities could no longer be taken out of Egypt (though those removed before 1983 are still legal to own and can be sold through auction houses).
In 1922, however, Carter and Lord Carnarvon regarded many objects in Tutankhamun’s tomb as theirs for the taking, Brier says. That was the way that Valley of the Kings excavations had worked for the previous 50 years, in a system that divided finds equally between Cairo’s Egyptian Museum and an expedition’s home institution. Taking personal mementos was also common.
Evidence of Carter’s casual pocketing of various artifacts while painstakingly clearing the boy king’s tomb continues to emerge. “Carter didn’t sell what he took,” Brier says. “But he felt he had a right to take certain items as the tomb’s excavator.” Recently recovered letters of English Egyptologist Alan Gardiner from the 1930s, described by Brier in his book, recount how Carter gave Gardiner several items from Tutankhamun’s tomb, including an ornament used as a food offering for the dead. French Egyptologist Marc Gabolde of Paul-Valéry Montpellier 3 University has tracked down beads, jewelry, a headdress fragment and other items taken from Tutankhamun’s tomb by Carter and Carnarvon.
Yet it is undeniable that one of Tutankhamun’s greatest legacies, thanks to Carter, is the benchmark the excavation of his tomb set for future excavations, Brier says. Carter started his career as an artist who copied painted images on the walls of Egyptian tombs for excavators. He later learned excavation techniques in the field working with an eminent English Egyptologist, Flinders Petrie. Carter took tomb documentation to a new level, rounding up a crack team consisting of a photographer, a conservator, two draftsmen, an engineer and an authority on ancient Egyptian writing.
Their decade-long effort also made possible the new Tutankhamun exhibition at the Grand Egyptian Museum. Now, not only museum visitors but also a new generation of researchers will have unprecedented access to the pharaoh’s tomb trove.
“Most of Tutankhamun’s [tomb] objects have been given little if any study beyond what Carter was able to do,” says UCLA’s Cooney.
That won’t be true for much longer, as the most famous tomb in the Valley of the Kings enters the next stage of its public and scientific afterlife.
Like the rubbery nubs on the bottom of baby socks, microstructures on the bears’ paw pads offer some extra friction, scientists report November 1 in the Journal of the Royal Society Interface. The pad protrusions may keep polar bears from slipping on snow, says Ali Dhinojwala, a polymer scientist at the University of Akron in Ohio who has also studied the sticking power of gecko feet (SN: 8/9/05). Nathaniel Orndorf, a materials scientist at Akron who focuses on ice, adhesion and friction, was interested in the work Dhinojwala’s lab did on geckos, but “we can’t really put geckos on the ice,” he says. So he turned to polar bears.
Orndorf teamed up with Dhinojwala and Austin Garner, an animal biologist now at Syracuse University in New York, and compared the paws of polar bears, brown bears, American black bears and a sun bear. All but the sun bear had paw pad bumps. But the polar bears’ bumps looked a little different. For a given diameter, their bumps tend to be taller, the team found. That extra height translates to more traction on lab-made snow, experiments with 3-D printed models of the bumps suggest.
Until now, scientists didn’t know that bump shape could make the difference between gripping and slipping, Dhinojwala says. Polar bear paw pads are also ringed with fur and are smaller than those of other bears, the team reports, adaptations that might let the Arctic animals conserve body heat as they trod upon ice. Smaller pads generally mean less real estate for grabbing the ground. So extra-grippy pads could help polar bears make the most of what they’ve got, Orndorf says.
Along with bumpy pads, the team hopes to study polar bears’ fuzzy paws and short claws, which might also give the animals a nonslip grip.
The closest black hole yet found is just 1,560 light-years from Earth, a new study reports. The black hole, dubbed Gaia BH1, is about 10 times the mass of the sun and orbits a sunlike star.
Most known black holes steal and eat gas from massive companion stars. That gas forms a disk around the black hole and glows brightly in X-rays. But hungry black holes are not the most common ones in our galaxy. Far more numerous are the tranquil black holes that are not mid-meal, which astronomers have dreamed of finding for decades. Previous claims of finding such black holes have so far not held up (SN: 5/6/20; SN: 3/11/22). So astrophysicist Kareem El-Badry and colleagues turned to newly released data from the Gaia spacecraft, which precisely maps the positions of billions of stars (SN: 6/13/22). A star orbiting a black hole at a safe distance won’t get eaten, but it will be pulled back and forth by the black hole’s gravity. Astronomers can detect the star’s motion and deduce the black hole’s presence.
Out of hundreds of thousands of stars that looked like they were tugged by an unseen object, just one seemed like a good black hole candidate. Follow-up observations with other telescopes support the black hole idea, the team reports November 2 in Monthly Notices of the Royal Astronomical Society.
Gaia BH1 is the nearest black hole to Earth ever discovered — the next closest is around 3,200 light-years away. But it’s probably not the closest that exists, or even the closest we’ll ever find. Astronomers think there are about 100 million black holes in the Milky Way, but almost all of them are invisible. “They’re just isolated, so we can’t see them,” says El-Badry, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
The next data release from Gaia is due out in 2025, and El-Badry expects it to bring more black hole bounty. “We think there are probably a lot that are closer,” he says. “Just finding one … suggests there are a bunch more to be found.”
There’s a new way to rip apart harmful “forever chemicals,” scientists say.
Perfluoroalkyl and polyfluoroalkyl substances, also known as PFAS, are found in nonstick pans, water-repellent fabrics and food packaging and they are pervasive throughout the environment. They’re nicknamed forever chemicals for their ability to stick around and not break down. In part, that’s because PFAS have a super strong bond between their carbon and fluorine atoms (SN: 6/4/19). Now, using a bit of heat and two relatively common compounds, researchers have degraded one major type of forever chemical in the lab, the team reports in the Aug. 19 Science. The work could help pave the way for a process for breaking down certain forever chemicals commercially, for instance by treating wastewater. “The fundamental knowledge of how the materials degrade is the single most important thing coming out of this study,” organic chemist William Dichtel said in an August 16 news conference.
While some scientists have found relatively simple ways of breaking down select PFAS, most degradation methods require harsh, energy-intensive processes using intense pressure — in some cases over 22 megapascals — or extremely high temperatures — sometimes upwards of 1000⁰ Celsius — to break the chemical bonds (SN: 6/3/22).
Dichtel, of Northwestern University in Evanston, Ill., and his team experimented with two substances found in nearly every chemistry lab cabinet: sodium hydroxide, also known as lye, and a solvent called dimethyl sulfoxide, or DMSO. The team worked specifically with a group of forever chemicals called PFCAs, which contain carboxylic acid and constitute a large percentage of all PFAS. Some of these kinds of forever chemicals are found in water-resistant clothes.
When the team combined PFCAs with the lye and DMSO at 120⁰ C and with no extra pressure needed, the carboxylic acid fell off the chemical and became carbon dioxide in a process called decarboxylation. What happened next was unexpected, Dichtel said. Loss of the acid led to a process causing “the entire molecule to fall apart in a cascade of complex reactions.” This cascade involved steps that degraded the rest of the chemical into fluoride ions and smaller carbon-containing products, leaving behind virtually no harmful by-products. .
“It’s a neat method, it’s different from other ones that have been tried,” says Chris Sales, an environmental engineer at Drexel University in Philadelphia who was not involved in the study. “The biggest question is, how could this be adapted and scaled up?” Northwestern has filed a provisional patent on behalf of the researchers.
Understanding this mechanism is just one step in undoing forever chemicals, Dichtel’s team said. And more research is needed: There are other classes of PFAS that require their own solutions. This process wouldn’t work to tackle PFAS out in the environment, because it requires a concentrated amount of the chemicals. But it could one day be used in wastewater treatment plants, where the pollutants could be filtered out of the water, concentrated and then broken down.
Some mosquitoes have a near-foolproof thirst for human blood. Previous attempts to prevent the insects from tracking people down by blocking part of mosquitoes’ ability to smell have failed. A new study hints it’s because the bloodsuckers have built-in workarounds to ensure they can always smell us.
For most animals, individual nerve cells in the olfactory system can detect just one type of odor. But Aedes aegypti mosquitoes’ nerve cells can each detect many smells, researchers report August 18 in Cell. That means if a cell were to lose the ability to detect one human odor, it still can pick up on other scents. The study provides the most detailed map yet of a mosquito’s sense of smell and suggests that concealing human aromas from the insects could be more complicated than researchers thought.
Repellents that block mosquitoes from detecting human-associated scents could be especially tricky to make. “Maybe instead of trying to mask them from finding us, it would be better to find odorants that mosquitoes don’t like to smell,” says Anandasankar Ray, a neuroscientist at the University of California, Riverside who was not involved in the work. Such repellents may confuse or irritate the bloodsuckers and send them flying away (SN: 9/21/11; SN: 3/4/21).
Effective repellents are a key tool to prevent mosquitoes from transmitting disease-causing viruses such as dengue and Zika (SN: 7/11/22). “Mosquitoes are responsible for more human deaths than any other creature,” says Olivia Goldman, a neurobiologist at Rockefeller University in New York City. “The better we understand them, the better that we can have these interventions.”
Mosquitoes that feed on people home in on a variety of cues when hunting, including body heat and body odor. The insects smell using their antennae and small appendages close to the mouth. Using three types of sensors in olfactory nerve cells, they can detect chemicals such as carbon dioxide from exhaled breath or components of body odor (SN: 7/16/15).
In previous work, researchers thought that blocking some sensors might hide human scents from mosquitoes by disrupting the smell messages sent to the brain (SN: 12/5/13). But even those sensor-deprived mosquitoes can still smell and bite people, says neurobiologist Margo Herre also of Rockefeller University.
So Goldman, Herre and colleagues added fluorescent labels to A. aegypti nerve cells, or neurons, to learn new details about how the mosquito brain deciphers human odors. Surprisingly, rather than finding the typical single type of sensor per nerve cell, the team found that individual mosquito neurons appear more like sensory hubs.
Genetic analyses confirmed that some of the olfactory nerve cells had more than one type of sensor. Some cells produced electrical signals in response to several mosquito-attracting chemicals found in humans such as octenol and triethyl amine — a sign the neurons could detect more than one type of odor molecule. A separate study published in April in eLife found similar results in fruit flies, which suggests such a system may be common among insects.
It’s unclear why having redundant ways of detecting people’s odors might be useful to mosquitoes. “Different people can smell very different from one another,” says study coauthor Meg Younger, a neurobiologist at Boston University. “Maybe this is a setup to find a human regardless of what variety of human body odor that human is emitting.”
