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Before yesterdayScience

Manta rays inspire faster swimming robots and better water filters

31 December 2024 at 11:50

Manta rays are elegantly shaped. They swim by flapping their fins like enormous wings, and their gills filter for plankton with the utmost precision. These creatures have now inspired human innovations that take soft robots and water filters to the next level.

With fins that borrow their shape and motion from mantas, a soft robot created by a team of researchers at North Carolina State University and the University of Virginia improves on a previous model by reaching speeds of 6.8 body lengths per second, nearly double what its predecessor was capable of. This makes it the fastest soft robot so far. It is also more energy-efficient than its previous iteration and can swim not just on the surface, but upward and downward, just like an actual manta ray.

Another research team at MIT used the gills of these creatures, which filter for plankton, to improve commercial water filtration systems. Their gill openings are also the perfect size to help them breathe while they feed, absorbing oxygen from water on its way out. The rays’ balance of feeding and breathing helped the researchers figure out a filter structure that more precisely controls inflow and outflow.

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Evolution journal editors resign en masse

30 December 2024 at 18:45

Over the holiday weekend, all but one member of the editorial board of Elsevier's Journal of Human Evolution (JHE) resigned "with heartfelt sadness and great regret," according to Retraction Watch, which helpfully provided an online PDF of the editors' full statement. It's the 20th mass resignation from a science journal since 2023 over various points of contention, per Retraction Watch, many in response to controversial changes in the business models used by the scientific publishing industry.

"This has been an exceptionally painful decision for each of us," the board members wrote in their statement. "The editors who have stewarded the journal over the past 38 years have invested immense time and energy in making JHE the leading journal in paleoanthropological research and have remained loyal and committed to the journal and our authors long after their terms ended. The [associate editors] have been equally loyal and committed. We all care deeply about the journal, our discipline, and our academic community; however, we find we can no longer work with Elsevier in good conscience."

The editorial board cited several changes made over the last ten years that it believes are counter to the journal's longstanding editorial principles. These included eliminating support for a copy editor and a special issues editor, leaving it to the editorial board to handle those duties. When the board expressed the need for a copy editor, Elsevier's response, they said, was "to maintain that the editors should not be paying attention to language, grammar, readability, consistency, or accuracy of proper nomenclature or formatting."

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Frogfish reveals how it evolved the “fishing rod” on its head

30 December 2024 at 18:27

Behold the frogfish. This bizarre creature really is a fish, despite its bullfrog face, pectoral fins that look like webbed feet, and a froglike mouth that snaps up unsuspecting prey.

But the way it lures its prey is even weirder. Frogfish belong to the anglerfish family known as Antennariidae. Like their anglerfish cousins who lurk in the ocean’s depths, these ambush predators attract their next meal via an appendage on their heads that they use like a fishing lure. This appendage is known as the illicium and thought to have once been a dorsal fin. It has a specialized skin flap, the esca at the end. It tantalizes small fish and crustaceans into thinking it’s a worm until they come too close.

How frogfish controlled the illicium was previously unknown. Led by biologist Naoyuki Yamamoto of Nagoya University, a team of researchers have now discovered that a specialized population of motor neurons have evolved to allow it to shake the illicium around like a wriggling worm. Yamamoto thinks they were originally dorsal fin motor neurons that became more specialized.

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Ten cool science stories we almost missed

30 December 2024 at 14:37

There is rarely time to write about every cool science paper that comes our way; many worthy candidates sadly fall through the cracks over the course of the year. But as 2024 comes to a close, we've gathered ten of our favorite such papers at the intersection of science and culture as a special treat, covering a broad range of topics: from reenacting Bronze Age spear combat and applying network theory to the music of Johann Sebastian Bach, to Spider-Man inspired web-slinging tech and a mathematical connection between a turbulent phase transition and your morning cup of coffee. Enjoy!

Reenacting Bronze Age spear combat

Experiment with experienced fighters who spar freely using different styles. An experiment with experienced fighters who spar freely using different styles. Credit: Valerio Gentile/CC BY

The European Bronze Age saw the rise of institutionalized warfare, evidenced by the many spearheads and similar weaponry archaeologists have unearthed. But how might these artifacts be used in actual combat? Dutch researchers decided to find out by constructing replicas of Bronze Age shields and spears and using them in realistic combat scenarios. They described their findings in an October paper published in the Journal of Archaeological Science.

There have been a couple of prior experimental studies on bronze spears, but per Valerio Gentile (now at the University of Gottingen) and coauthors, practical research to date has been quite narrow in scope, focusing on throwing weapons against static shields. Coauthors C.J. van Dijk of the National Military Museum in the Netherlands and independent researcher O. Ter Mors each had more than a decade of experience teaching traditional martial arts, specializing in medieval polearms and one-handed weapons. So they were ideal candidates for testing the replica spears and shields.

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A Cold War mystery: Why did Jimmy Carter save the space shuttle?

30 December 2024 at 13:58

We’d been chatting for the better part of two hours when Chris Kraft’s eyes suddenly brightened. “Hey,” he said, “Here’s a story I’ll bet you never heard.” Kraft, the man who had written flight rules for NASA at the dawn of US spaceflight and supervised the Apollo program, had invited me to his home south of Houston for one of our periodic talks about space policy and space history. As we sat in recliners upstairs, in a den overlooking the Bay Oaks Country Club, Kraft told me about a time the space shuttle almost got canceled.

It was the late 1970s, when Kraft directed the Johnson Space Center, the home of the space shuttle program. At the time, the winged vehicle had progressed deep into a development phase that started in 1971. Because the program had not received enough money to cover development costs, some aspects of the vehicle (such as its thermal protective tiles) were delayed into future budget cycles. In another budget trick, NASA committed $158 million in fiscal year 1979 funds for work done during the previous fiscal year.

This could not go on, and according to Kraft the situation boiled over during a 1978 meeting in a large conference floor on the 9th floor of Building 1, the Houston center’s headquarters. All the program managers and other center directors gathered there along with NASA’s top leadership. That meeting included Administrator Robert Frosch, a physicist President Carter had appointed a year earlier.

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When does your brain think something is worth the wait?

30 December 2024 at 13:15

Whether it’s braving the long line at a trendy new restaurant or hanging on just a few minutes longer to see if there’s a post-credits scene after a movie, the decision to persevere or ditch it depends on specific regions of our brains.

Waiting is not always about self-control. Deciding to wait (or not to wait) also involves gauging the value of the potential reward. In an experiment that investigated wait times among people with lesions in the frontal cortex of the brain, University of Pennsylvania psychologist Joe Kable and his research team found that subjects with damage to certain regions of the prefrontal cortex were less likely to wait things out.

“[Our] findings suggest that regions of the frontal cortex make computationally distinct contributions to adaptive persistence,” he and his team said in a study recently published in the Journal of Neuroscience.

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After 60 years of spaceflight patches, here are some of our favorites

29 December 2024 at 12:00

The art of space mission patches is now more than six decades old, dating to the Vostok 6 mission in 1963 that carried Soviet cosmonaut Valentina Tereshkova into low-Earth orbit for nearly three days. The patch for the first female human spaceflight showcased a dove flying above the letters designating the Soviet Union, CCCP.

That patch was not publicly revealed at the time, and the use of specially designed patches was employed only infrequently by subsequent Soviet missions. NASA's first mission patch would not follow for two years, but the practice would prove more sticky for missions in the United States and become a time-honored tradition.

The first NASA flight to produce a mission-specific patch worn by crew members was Gemini 5. It flew in August 1965, carrying astronauts Gordon Cooper and Pete Conrad on an eight-day mission inside a small Gemini spacecraft. At the time, it was the longest spaceflight conducted by anyone.

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The physics of ugly Christmas sweaters

27 December 2024 at 19:00

'Tis the season for many holiday traditions, including the Ugly Christmas Sweater—you know, those 1950s-style heavy knits featuring some kind of cartoonish seasonal decoration, like snowflakes, Santa Claus, or—in the case of Mark Darcy from Bridget Jones' Diary (2001)—Rudolph the Red-Nosed Reindeer. "It’s obnoxious and tacky, but also fuzzy and kind of wholesome—the fashion equivalent of a Hallmark Christmas movie (with a healthy dose of tongue-in-cheek)," as CNN's Marianna Cerini recently observed.

Fashion (or lack thereof) aside, sweaters and other knitted fabric are also fascinating to physicists and mathematicians. Case in point: a recent paper published in the journal Physical Review Letters examining the complex mechanics behind the many resting shapes a good Jersey knit can form while at rest.

Knitted fabrics are part of a class of intertwined materials—which also includes birds' nests, surgical knots, knotted shoelaces, and even the degradation of paper fibers in ancient manuscripts. Knitted fabrics are technically a type of metamaterial: an engineered material that gets its properties not from the base materials but from their designed structures. The elasticity (aka, stretchiness) of knitted fabrics is an emergent property: the whole is more than the sum of its parts. How those components (strands of yarn) are arranged at an intermediate scale (the structure) determines the macro scale properties of the resulting fabric.

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Could microwaved grapes be used for quantum sensing?

27 December 2024 at 15:46

There are thousands of YouTube videos in which DIY science enthusiasts cut grapes in half—leaving just a thin bit of skin connecting them—and put the grapes in the microwave, just to marvel at the sparks and plume of ionized gas (plasma) that the grapes produce. This quirky property of grapes might help make more efficient quantum sensors, according to a new paper published in the journal Physical Review Applied.

The plasma-inducing grape effect was first observed in 1994, per the authors. As previously reported, the usual explanation for the generation of plasmas is that grapes are so small that the irradiating microwaves become highly concentrated in the grape tissue, ripping some the molecules apart to generate charged ions (adding to the electrolytes already present in the grapes). The electromagnetic field that forms causes ions to flow from one grape half to the other via the connecting skin—at least at first. That's when you get the initial sparks. Eventually, the ions start passing through the surrounding air as well, ionizing it to produce that hot plume of plasma.

But in 2019, Trent University scientists showed that explanation isn't quite right. The skin bridge isn't necessary for the effect to occur. Rather, the plasma is generated by an electromagnetic "hot spot." The grapes have the right refractive index and size to "trap" microwaves, so putting two of them close together leads to the generation of a hot spot between them. The trick also works with gooseberries, large blackberries, and quail eggs, as well as hydrogel beads—plastic beads soaked in water. ("Many microwaves were in fact harmed during the experiments," co-author Hamza Khattak admitted at the time.)

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Magnetic shape-shifting surface can move stuff without grasping it 

27 December 2024 at 13:45

When you want to move an object from one place to another, you usually grab it with your hands or a robotic arm. But what if you want to move something you cannot touch without damaging or disrupting it, like a droplet of liquid? A solution proposed by a team of scientists at the North Carolina State University is a metamaterial that can change shape in response to magnetic fields.

This material had to be easily deformable to change shape, yet at the same time stiff enough to bear loads. “That seemed contradictory—how do you make something that is stiff and deformable at once?” says Jie Yin, a mechanical metamaterials researcher at NC State. His team did it with ferromagnetic elastomers, kirigami cuts, balloons, and magnets.

Refreshable Braille display

“There is not much research on using magnets to manipulate non-magnetic objects. It is very, very hard,” says Yinding Chi, another NC State researcher and lead author of the study. The idea Chi and his colleagues came up with could be compared to a refreshable Braille display. They imagined a surface dotted with domes that could rise, turn, or depress on demand, allowing it to dynamically form relief-like images or move in a pattern similar to waves in the ocean. Objects would then move on these surfaces like they were carried by waves. “This way, you can move various objects without using grippers,” Yin says.

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Craving carbs? Blame an ancient gene.

27 December 2024 at 12:25

There is now a genetic excuse not to bother cutting carbs. Humans have genetically adapted to eating starchy foods, and our ancestors may have been carb-ivores even before modern Homo sapiens emerged.

The salivary amylase gene, known as AMY1, is already known to have helped us adapt to eating carbs. It encodes amylase, an enzyme that breaks starches found in pasta and bread down to glucose—and may have given us a taste preference for them. Humans have multiple copies of the gene, which may help us produce high levels of the enzyme.

Researchers from the University of Buffalo and the Jackson Laboratory have now found that, while most copies of this gene arose with the advent of farming, modern humans and our closest relatives had accumulated extra copies long before agriculture.

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Flu surges in Louisiana as health department barred from promoting flu shots

By: Beth Mole
23 December 2024 at 17:35

Flu season is ramping up across the US, but Louisiana—the state that has reportedly barred its health department from promoting flu shots, as well as COVID-19 and mpox vaccines—is leading the country with an early and strong surge.

Louisiana's flu activity has reached the "Very High" category set by the Centers for Disease Control and Prevention, according to the latest data. The 13-category scale is based on the percentage of doctor's visits that were for influenza-like illnesses (ILIs) in the previous week. Louisiana is at the first of three "Very High" levels. Oregon is the only other state to have reached this level. The rest of the country spans the scale, with 13 jurisdictions at "High," including New York City and Washington, DC. There are 11 at "Moderate," 10 at "Low," and 19 at "Minimal."

Map of ILI activity by state Credit: CDC

Last week, NPR, KFF Health News, and New Orleans Public Radio WWNO reported that the state had forbidden the health department and its workers from promoting annual flu shots, as well as vaccines for COVID-19 and mpox. The policy was explicitly kept quiet and officials have avoided putting it in writing.

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Green sea turtle gets relief from “bubble butt” syndrome thanks to 3D printing

21 December 2024 at 12:25

Charlotte, a green sea turtle, was hit by a boat back in 2008. This left it with an affliction colloquially referred to as the “bubble butt,” a kind of floating syndrome that makes it impossible for a turtle to dive. Most sea turtles suffering from issues like this simply die at sea, since the condition leaves them stranded at the surface where they can’t forage, sleep, and avoid predators like sharks. But fate had other plans for Charlotte.

Charlotte didn’t end up as a shark’s lunch and didn’t starve to death floating helplessly in the ocean. Instead, it got rescued shortly after the boat accident and eventually found a home at Mystic Aquarium in Stonington, Connecticut, where it received professional care. That was the first time Charlotte got lucky. The second time came when a collaboration formed: Adia, a company specializing in 3D-printing solutions; Formlabs, one of the world’s leading manufacturers of 3D printers; and New Balance Athletic, a sportswear giant based in Boston. This team chose Charlotte as a technology showcase, which basically turned the turtle into an Oscar Pistorius of the sea—just without the criminal conviction.

Weights and diet

Sea turtles are marine reptiles, which means they don’t have gills like fish—they need air to breathe. The lungs also play a key role in their buoyancy regulation system, which allows them to rest for extended periods of time at the sea floor or float at a precisely chosen depth. A sea turtle can precisely choose the depth at which it achieves neutral buoyancy by inhaling the exactly right volume of air.

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Exploring an undersea terrain sculpted by glaciers and volcanoes

21 December 2024 at 11:09

On May 2, 2008, the Chaitén volcano in Chile awoke with unexpected fury after more than 9,000 years of dormancy. The eruption blasted rocks and ash a dozen miles into the air, and then heavy rainfall swept the fallen debris up in immense mudflows. A river of rubble carved a destructive path through the nearby town of Chaitén before surging into the sea. The town, practically split in two by the torrent that cut through its middle, was evacuated as ash blanketed over 200,000 square kilometers of surrounding land.

While the terrestrial aftermath was plain to see, captured by both the local media and satellites, the impact on the sea was unknown.

Mists shroud the hillsides at the entrance to Chaitén Bay, as seen from aboard the Schmidt Ocean Institute’s <em>Falkor (too)</em> research vessel. Credit: Alex Ingle / Schmidt Ocean Institute

The eruption released over 750 billion liters of lava—enough to fill more than 300,000 Olympic-sized swimming pools—mainly in the form of rock fragments. The debris flowed through rivers into the Northern Patagonian Sea, just six miles away.

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Rocket Report: ULA has a wild idea; Starliner crew will stay in orbit even longer

20 December 2024 at 19:40

Welcome to Edition 7.24 of the Rocket Report! This is the last Rocket Report of the year, and what a year it's been. So far, there have been 244 rocket launches to successfully reach orbit this year, a record for annual launch activity. And there are still a couple of weeks to go before the calendar turns to 2025. Time is running out for Blue Origin to launch its first heavy-lift New Glenn rocket this year, but if it flies before January 1, it will certainly be one of the top space stories of 2024.

As always, we welcome reader submissions. If you don't want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets as well as a quick look ahead at the next three launches on the calendar.

Corkscrew in the sky. A Japanese space startup said its second attempt to launch a rocket carrying small satellites into orbit had been terminated minutes after liftoff Wednesday and destroyed itself again, nine months after the company’s first launch attempt in an explosion, the Associated Press reports. The startup that developed the rocket, named Space One, launched the Kairos rocket from a privately owned coastal spaceport in Japan's Kansai region. Company executive and space engineer Mamoru Endo said an abnormality in the first stage engine nozzle or its control system is likely to have caused an unstable flight of the rocket, which started spiraling in mid-flight and eventually destroyed itself about three minutes after liftoff, using its autonomous safety mechanism.

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Louisiana bars health dept. from promoting flu, COVID, mpox vaccines: Report

By: Beth Mole
20 December 2024 at 15:58

Louisiana's health department has been barred from advertising or promoting vaccines for flu, COVID-19, and mpox, according to reporting by NPR, KFF Health News, and New Orleans Public Radio WWNO.

Their investigative report—based on interviews with multiple health department employees who spoke on the condition of anonymity for fear of retaliation—revealed that employees were told of the startling policy change in meetings in October and November and that the policy would be implemented quietly and not put into writing.

Ars Technica has contacted the health department for comment and will update this post with any new information.

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Journal that published faulty black plastic study removed from science index

By: Beth Mole
19 December 2024 at 17:36

The publisher of a high-profile, now-corrected study on black plastics has been removed from a critical index of academic journals after failing to meet quality criteria, according to a report by Retraction Watch.

On December 16, Clarivate—a scholarly publication analytics company—removed the journal Chemosphere from its platform, the Web of Science, which is a key index for academic journals. The indexing platform tracks citations and calculates journal "impact factors," a proxy for relevance in its field. It's a critical metric not only for the journals but for the academic authors of the journal's articles, who use the score in their pursuit of promotions and research funding.

To be included in the Web of Science, Clarivate requires journals to follow editorial quality criteria. In an email to Ars Technica, Clarivate confirmed that Chemosphere was removed for "not meeting one or more of the quality criteria." According to Retraction Watch, Chemosphere has retracted eight articles this month and published 60 expressions of concern since April.

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Solving renewable energy’s sticky storage problem

When the Sun is blazing and the wind is blowing, Germany’s solar and wind power plants swing into high gear. For nine days in July 2023, renewables produced more than 70 percent of the electricity generated in the country; there are times when wind turbines even need to be turned off to avoid overloading the grid.

But on other days, clouds mute solar energy down to a flicker and wind turbines languish. For nearly a week in January 2023, renewable energy generation fell to less than 30 percent of the nation’s total, and gas-, oil- and coal-powered plants revved up to pick up the slack.

Germans call these periods Dunkelflauten, meaning “dark doldrums,” and they can last for a week or longer. They’re a major concern for doldrum-afflicted places like Germany and parts of the United States as nations increasingly push renewable-energy development. Solar and wind combined contribute 40 percent of overall energy generation in Germany and 15 percent in the US and, as of December 2024, both countries have goals of becoming 100 percent clean-energy-powered by 2035.

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Louisiana resident in critical condition with H5N1 bird flu

By: Beth Mole
18 December 2024 at 21:41

The Louisiana resident infected with H5N1 bird flu is hospitalized in critical condition and suffering from severe respiratory symptoms, the Louisiana health department revealed Wednesday.

The health department had reported the presumptive positive case on Friday and noted the person was hospitalized, as Ars reported. But a spokesperson had, at the time, declined to provide Ars with the patient's condition or further details, citing patient confidentiality and an ongoing public health investigation.

This morning, the Centers for Disease Control and Prevention announced that it had confirmed the state's H5N1 testing and determined that the case "marks the first instance of severe illness linked to the virus in the United States."

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