177268743
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sciencehabit writes:
Before the silver or gold in your favorite piece of jewelry made its way to Earth, it first had to spawn during one of the universe’s most energetic explosions. At first, astronomers knew of only one cosmic scenario that fit the bill for this violent formation of “jewelry shop” elements: the collision of two ultra-dense stellar corpses called neutron stars. Now, a second has stepped onto the scene.
As they report this week in The Astrophysical Journal Letters, researchers have discovered signatures of this heavy element formation — called the r-process — in a giant flare first detected from a highly magnetic neutron star in 2004.
The flare, which released more energy than our Sun does in a million years as it spewed electrically charged material, has remained shrouded in mystery since its discovery 20 years ago. Researchers quickly traced the outburst to a nearby magnetar, a special breed of neutron star whose magnetic fields are trillions times stronger than Earth’s. But ten minutes after the massive flare, a second, fainter signal inexplicably came from the same star.
More r-process sources may still be looming in the dark. The new study accounts for about 10% of the Milky Way’s heavy elements, suggesting that astronomers will have to scour the cosmos for even more places where the r-process is hiding. One potential spot is a rare type of supernova that births rapidly rotating neutron stars, says says Anirudh Patel, the new study’s lead author and an astronomer at Columbia University. He
hopes that with more observations, astronomers will be able to sharpen that picture. But for now, he says it’s exciting enough to find a new birthplace for what makes up so much of our world: “These heavy elements pervade our lives — we make use of them every day. It’s humbling to realize that these were made in such extreme astrophysical environments.”
177236075
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sciencehabit writes:
On a cool, sunny, mid-April day, the cheerful redbuds and other flowering trees amid the sprawling labs on the National Institutes of Health (NIH) main campus belied the pervasive gloom. Nearly 3 months into President Donald Trump’s administration, NIH in-house scientists and other workers were reeling from mass layoffs of colleagues; the removal of leaders; and limits on travel, communication, and purchasing that have shut the agency off from the outside world, hamstrung experiments, and crushed the community’s spirits.
On that spring day in Bethesda, Maryland, one senior scientist lamented that two star colleagues in his institute were heading back to their native China from NIH, abandoning a destination that had always drawn talent from around the world. “I want to cry,” he said. Another pointed to the abrupt retirement the previous day of a noted NIH nutrition scientist who said the agency had censored his publications and interactions with the media.
The Department of Government Efficiency (DOGE), billionaire Elon Musk’s quasi-official White House enforcer, “pops in and out” of online meetings of senior leaders, the scientists said. Another researcher, who is not a U.S. citizen, mentioned that he has prepared a “deportation plan,” including a company lined up to ship belongings back to his native country, in case he’s fired and loses his work visa.
The atmosphere is one of “chaos and fear and frustration and anger,” said a senior scientist with NIH’s intramural research program who, like others, spoke on condition of anonymity to protect themselves and others from retribution. This scientist added: “It’s this feeling of utter powerlessness and repeated insults.”
A former top NIH official who was forced out believes that’s the intent. “I think the plan is to sow as much chaos as possible. I think they want a dispirited workforce at NIH so people will just say ‘to hell with it’ and leave.”
It’s working. Hundreds of NIH employees took voluntary buyouts offered by the Trump administration. And at least 25 of the roughly 320 physician-researchers who lead trials of drugs, cell therapies, and vaccines at NIH’s massive Clinical Center are leaving, as are consulting physicians, a researcher there told Science.
176995035
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sciencehabit writes:
In 2001, archaeologists made a discovery that promised to rewrite the history of cat domestication. Scientists had long believed cats became our friends in ancient Egypt, where they’ve been immortalized in mummies and art. But when researchers dug beneath a 9500-year-old home in a farming village on the Mediterranean island of Cyprus, they discovered what appeared to be a pet cat buried with a human—more than 4000 years before ancient Egypt even existed.
And so a new story began to take shape. The discovery of other ancient cat bones across Europe persuaded many scientists that domestication began when wildcats slunk into the villages of early farmers—perhaps in what is now Turkey—and eventually evolved into the housecats we know today. As these farmers migrated to new parts of Europe, they brought their feline companions with them.
Now, two studies—both posted late last month on the preprint server bioRxiv—restore the focus on Egypt. Ancient bones and DNA from cats across Europe and the Mediterranean suggest they may have been domesticated in Egypt after all, possibly as recently as 3000 years ago. The process, one of the new papers theorizes, was a gruesome one: Mass sacrifices of cats tied to a religious cult instilled tameness over many generations. “It’s the murder pathway of domestication,” says Greger Larson, an evolutionary biologist at the University of Oxford and author on both studies.
176902105
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sciencehabit writes:
With his little round glasses tucked into his helmet and a less than explosive stride, Mikhail Lukin could never be mistaken for a professional hockey player. A world-renowned physicist and expert in quantum computing at Harvard University, Lukin played hockey growing up in Russia and clearly knows what he’s doing. But, at 53, he doesn’t do anything on skates fast.
And, yet, the lanky lefty still possesses a scorer’s touch, as he showed at a friendly hockey game he helped organize last month at the American Physical Society’s (APS’s) Global Physics Summit. At least four times, Lukin ends up the right place at the right time to drive home a rebound or tip in a cross-ice pass for an easy goal. However, one of Lukin’s own teammates suggests his offense comes at the expense of his defense. “Misha never backchecks,” says Kunal Tiwari, a physicist at the Massachusetts Institute of Technology’s (MIT’s) Lincoln Laboratory. “I don’t want you to attribute that to me.”
Now something of a fixture at APS’s biggest annual meeting, the “quantum hockey” game grew out of a weekly pickup session Lukin organizes for physicists at Harvard and MIT. When APS met in Boston in 2019, he and Andreas Wallraff, a physicist at ETH Zürich, decided to open the skate to meeting attendees. Since then, the two lifelong hockey players have taken the game on the road, when possible. In 2020, “I was standing in front of my house with my hockey gear, ready to go, when the meeting in Denver was canceled because of COVID,” Wallraff recalls.
Nominally, the contest is a grudge match between scientists working on two different basic technologies for quantum computing. Wallraff captains the Superconducting Lightning, which comprises mostly researchers working with quantum bits, or qubits, made of tiny superconducting electrical circuits. Lukin leads the Mighty Atomic Strike, whose roster is filled with researchers working with qubits made of individual atoms. “We’ve got the superior platform, so we’ve got to show it on the ice, too,” says Justin Perron, a Strike member from California State University San Marcos.
Though obviously fun, the game serves a deeper purpose, Lukin says. Quantum computing isn’t just a prestigious scientific field, it’s also a budding industry in which startups can ink deals worth hundreds of millions of dollars. With so much at stake, rivalries can boil over. Just the day before at the meeting, tempers flared over Microsoft’s controversial claim to have fashioned a particular type of qubit. The game helps cut the tension, Lukin notes. “For community building, this is really useful,” he says. “It’s a very competitive field.”
176830741
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sciencehabit writes:
Growing up to 55 meters tall in the tropical forests of Panama, the almendro tree is a natural lightning rod. And that appears to be a good thing: The millions of volts that course through this species during a strike electrocute parasitic vines and leap from branches, killing nearby trees that might compete for the almendro’s sunlight, researchers report today in New Phytologist.
In a recent survey of a patch of Panamanian jungle, scientists found that Almendro trees (Dipteryx oleifera) seemed particularly resilient to lightning strikes. All nine that had been struck were practically unscathed, losing only small patches of leaves. In comparison, similarly tall trees of other species took nearly six times as much damage; 40% of their upper branches and leaves were destroyed, on average, and 64% of those trees died within the first 2 years after being struck.
The only thing that died on the almendros were the vines. Called lianas, they grow over a tree's foliage, robbing it of light. These vines are so aggressive they can stunt tree growth and reproduction.
Another benefit of the lightning strikes: smaller trees surrounding the almendros took collateral damage. Within weeks, the shorter trees’ branch tips began to die, presumably because electrical current had sparked across the air, passed through touching leaves, or flowed through shared vines. Over several months, many bystander trees slowly lost leaves and died.
The researchers calculated that living near an almendro increases a given tree’s likelihood of dying during a strike by 48%—so lightning may help eliminate trees that might grow tall enough to compete for an almendro's sunlight, says the lead researcher. "Any tree that gets close essentially gets electrocuted."
176829393
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sciencehabit writes:
Whales sing, orcas squeal, and sea turtles croak. But sharks are more the strong, silent type. Now, researchers report the first evidence that sharks make sounds, too, described today in Royal Society Open Science.
The animals may be making the sounds--a series of clicking noises--by snapping their flat rows of teeth, which are blunt for crushing prey. The sharks can hear mostly low-frequency noise, and the clicks they emit are higher pitched, which suggests they are not for communicating with other rigs. It’s possible they are a defensive tactic. Marine mammals that eat rigs, such as leopard seals, can hear in the frequency range of the rig clicks, but the researchers question whether a few clicks would deter an attack. The sounds might be part of their response to being startled, the team says.
176802991
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sciencehabit writes:
When clocks across most of the United States “sprang” forward on 9 March to mark the start of daylight saving time, many people woke up feeling groggy, irritable, and like they had just lost an hour of precious sleep. Those grievances—along with a growing body of research linking clock changes to negative health impacts—are part of why 54% of people in the United States are eager to abolish the century-old practice.
If the U.S. sunsets daylight saving time, however, what will take its place? Some legislators have proposed making daylight saving time the national year-round standard, which sleep researchers oppose on the basis that its extra-dark mornings and extra-bright evenings would dangerously disrupt people’s sleep. Many medical and scientific organizations instead advocate for permanent standard time (an option that, according to recent polls, is also preferred by nearly half of U.S. residents).
But there isn’t consensus within academic circles: In a provocative paper published last week in Royal Society Open Science, two physicists argue that the current system’s problems may be overblown—and that we should think twice before getting rid of seasonal clock changes.
Why do we have this clock system in the first place? What are the risks and health impacts of daylight saving? And what are the alternatives? Here’s what we know.
176777945
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sciencehabit writes:
Dark energy, the mysterious force accelerating the expansion of the universe, may not have always provided a steady push as cosmologists have assumed for decades. Instead, the latest data from the powerful Dark Energy Spectroscopic Instrument (DESI) add more evidence that the universe’s expansion accelerated faster in the past than it is doing now. DESI’s picture of “dynamical dark energy” will both delight and confound theorists, who have despaired at the lack of clues to dark energy’s physical cause but were not expecting what DESI is now seeing.
“I think the implications for cosmology are going to be profound,” says Bhuvnesh Jain, a cosmologist at the University of Pennsylvania. “It’s very exciting,” adds astronomer Eric Gawiser of Rutgers University. “But it also is going to cause people to be a little bit suspicious: Can dark energy really do that?”
176771601
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sciencehabit writes:
Neanderthals were hypercarnivores at the top of the food chain, eating as much meat as hyenas and cave lions. Or at least many researchers have assumed. But meat wasn’t the only thing on their menu, according to a presentation last week at the annual meeting of the American Association of Biological Anthropologists: Our close cousins may have consumed lots of maggots.
In 1991, researchers first revealed that the fossilized bones of Neanderthals had high ratios of nitrogen 15 compared with nitrogen 14—usually the signature of a high-meat diet. The values suggested Neanderthals were bigger meat eaters than even hypercarnivorous hyenas and lions. Butchered animal bones at archaeological sites reinforced the view that our close relatives relied heavily on meat from big game hunting.
But biological anthropologist Melanie Beasley of Purdue University began to question this assumption when she read a report in PaleoAnthropology a few years ago by archaeologist John Speth of the University of Michigan. Speth’s article noted that missionaries and Arctic explorers’ accounts of people who fell sick with “rabbit starvation”—an illness that afflicts those who eat mainly lean, high-protein game meat and too little fat.
Beasley conducted an experiment at the Body Farm, which was established to study human decomposition. There, she tested nitrogen levels in the rotting tissue of 34 donated human corpses left outdoors, as well as in the maggots that fed on it. The work suggested that the high levels of nitrogen found in Neanderthal bones could correlate with a diet high in maggots. The finding makes sense: maggots are practically unavoidable when processing game outside. They are also easy to scoop from the soil beneath a carcass, she notes. And they’re a salty tasting food full of fat and protein enjoyed by many modern foraging groups
176770579
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sciencehabit writes:
When Emma saw a posting for a faculty position in the University of Mississippi’s School of Pharmacy late last year, she thought she’d found her dream job. The early-career chemist, who asked not to use her real name so as not to jeopardize her current role, had already moved from Europe to the United States and was committed to staying.
But by the time she’d cleared the application process and was negotiating for equipment and personnel, she started to have major reservations. “Every day I would see news articles on federal workers who were let go, funds being withheld unless [diversity, equity, and inclusion] initiatives were shut down, and speculation on whether the Department of Education was going to be abolished,” she says. She worried about a lack of future funding, and about ricocheting effects on universities, students, and staff. Last month, “I decided to withdraw my candidacy despite being offered everything I needed,” she says.
Emma now plans to move back to Europe. She’s not alone: Universities around the world have reported seeing an uptick in applications from U.S.-based researchers, who face an increasingly uncertain climate under President Donald Trump’s administration. And some countries and their institutions are already looking to use the opportunity to attract new talent and reverse the steady migration of scientists to the U.S. in recent decades.
176770561
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sciencehabit writes:
A strange-looking telescope that scanned the skies from a perch in northern Chile for 15 years has released its final data set: detailed maps of the infant universe showing the roiling clouds of hydrogen and helium gas that would one day coalesce into the stars and galaxies we see today.
The Atacama Cosmology Telescope is not the first to survey the cosmic microwave background (CMB), the light released 380,000 years after the Big Bang when the early universe’s soup of particles formed atoms and space became transparent. But the data—posted as preprints online today—give researchers a new level of detail on the density of the gas clouds and how they were moving.
Using the data, researchers tested how well the standard cosmological theory, known as lambda cold dark matter, described the universe at that time 13.8 billion years ago; it’s a remarkably good fit, they conclude.
176569765
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sciencehabit writes:
By squeezing a packet of laser light into a tiny sliver of a second, physicists can produce superintense pulses that, if only for an instant, deliver as much power as 1 million nuclear plants. Such petawatt lasers have enabled scientists to manipulate materials in new ways, emulate the conditions inside planets, and even split atoms. Now, accelerator physicists have matched that feat, producing petawatt pulses of electrons that could also have spectacular applications.
Superintense electron bunches might someday even probe the nature of empty space. They produce a hugely intense electric field, so if one of them were to collide with an ultraintense laser pulse, which also contains a huge electric field, it would expose space to an incredibly strong electrical polarization, D’Arcy notes. If that field is strong enough, it should begin to rip particle-antiparticle pairs out of the vacuum, a phenomenon predicted by quantum physics but never observed.
That’s still a distant goal, but researchers might get within shouting distance of it if they could make the electron pulses 10 times shorter. Researchers plan to do just that, making the additional chirp even more dramatic by replacing the laser with a more complex scheme involving a cell of plasma. “We generated 100-kiloamp beams, now the next step is getting to mega-amp beams.”
176062157
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sciencehabit writes:
Legend has it that if you walk along Old Light Road in Summerville, South Carolina, you might see an eerie glow hovering over an abandoned rail line in the nearby woods. Old-timers will tell you it’s a spectral lantern held by the apparition of a woman searching for her decapitated husband’s head. Susan Hough has proposed a scientific explanation that is far more plausible, however. A seismologist with the U.S. Geological Survey, she believes the so-called Summerville Light could represent a rare natural phenomenon: earthquake lights.
Sparks from steel rail tracks could ignite radon or other gases released from the ground by seismic shaking, Hough explains:
In Summerville, I think it’s the railroad tracks that matter. I’ve crawled around tracks during my fieldwork in South Carolina. Historically, when [rail companies] replaced tracks, they didn’t always haul the old track away. So, you’ve got heaps of steel out there. Sparks might be part of the story. And maybe the railroads are important for another reason. They may naturally follow fault lines that have carved corridors through the landscape.
175714003
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sciencehabit writes:
With a few keystrokes, anyone can ask an artificial intelligence (AI) program such as ChatGPT to write them a term paper, a rap song, or a play. But don’t expect William Shakespeare’s originality. A new study finds such output remains derivative—at least for now.
Objectively testing this creativity has been tricky. Scientists have generally taken two tacks. One is to use another computer program to search for signs of plagiarism—though a lack of plagiarism does not necessarily equal creativity. The other approach is to have humans judge the AI output themselves, rating factors such as fluency and originality. But that’s subjective and time intensive.
So Ximing Lu, a computer scientist at the University of Washington, and colleagues created a program featuring both objectivity and a bit of nuance. Called DJ Search, it collects pieces of text of a minimum length from whatever the AI outputs and searches for them in large online databases. DJ Search doesn’t just look for identical matches; it also scans for strings whose words have similar meanings. To evaluate the meaning of a word or phrase, the program itself relies on a separate AI algorithm that produces a set of numbers called an “embedding,” which roughly represents the contexts in which words are typically found. Synonymous words have numerically close embeddings. For example, phrases that swap “anticipation” and “excitement” are considered matches.
After removing all matches, the program calculates the ratio of the remaining words to the original document length, which should give an estimate of how much of the AI’s output is novel. The program conducts this process for various string lengths (the study uses a minimum of five words) and combines the ratios into one index of linguistic novelty. (The team calls it a “creativity index,” but creativity requires both novelty and quality—random gibberish is novel but not creative.)
The researchers compared the linguistic novelty of published novels, poetry, and speeches with works written by recent LLMs. Humans outscored AIs by about 80% in poetry, 100% in novels, and 150% in speeches, the researchers report in a preprint posted on OpenReview and currently under peer review.
Although DJ Search was designed for comparing people and machines, it can also be used to compare two or more humanmade works. For example, Suzanne Collins’s 2008 novel The Hunger Games scored 35% higher in linguistic originality than Stephenie Meyer’s 2005 hit Twilight. (You can try the tool online.)
So, are LLMs merely parrots? Lu says they’re more like DJs. “They copy, paste, chop, and put together pieces from existing writing to make something amazing,” she says. “It’s like a DJ remixing existing music. This is definitely valuable, but it’s different from a composer.”
175554513
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sciencehabit writes:
It would be pretty easy to guess that Garfield was a tomcat even if you didn’t know his name—or didn’t want to peek under his tail. Most orange cats are boys, a quirk of feline genetics that also explains why almost all calicos and tortoiseshells are girls.
Scientists curious about those sex differences—or perhaps just cat lovers—have spent more than 60 years unsuccessfully seeking the gene that causes orange fur and the striking patchwork of colors in calicos and tortoiseshells. Now, two teams have independently found the long-awaited mutation and discovered a protein that influences hair color in a way never seen before in any animal.
Unlike other mammals, the coat colors of cats are partially determined by their sex. Besides orange cats typically being male, calicos and tortoiseshells are almost always female. The phenomenon is due to a quirk in feline genetics: Female cats inherit an X chromosome—the suspected home of the orange fur gene—from each parent. Cells don't generally need both, however, so during embryonic development each cell randomly chooses one X to express genes from, giving calicos and tortoiseshells their striking orange and black patterns. But despite 60 years of searching, scientists haven’t figured out exactly which gene is responsible for the orange color.
In preprints published this month on bioRxiv, scientists say they have independently found the long-awaited orange mutation and discovered a protein that influences hair color in a way never seen before in any animal. Using skin samples collected from various cats, the researchers were able to hone in a mutation on the X chromosome that impacts how much of a protein a gene called Arhgap36 produces. Increasing the amount of the Arhgap36 in pigment producing cells called melanocytes activates a molecular pathway that produces a light red pigment.
“It’s a long-awaited gene,” says Leslie Lyons, a feline geneticist at the University of Missouri in Columbia. Research into cat color has revealed all kinds of phenomena, she says, including how the environment influences gene expression. “Everything you need to know about genetics you can learn from your cat.”
