Science – Page 3

Trump withdraws US from world’s most important climate treaty

climate change, IPCC, Science, Trump, UN Framework Convention on Climate Change / Kelly Newman / January 8, 2026

The actual impact of the US withdrawal on many of the UN bodies singled out by Trump would depend on how aggressively his administration followed through on its announcement.

The head of one of the UN bodies named in the executive order said that the full effect of the move would become clear only during the UN’s annual budget allocation process.

“If they want to be difficult they could block the adoption of our budget. So it depends on how far they want to take it,” the person added.

Although the list caused anguish among environmental groups, it did not go as far as originally envisaged on trade and economic matters after the administration quietly dropped the World Trade Organization and the OECD from its list of potential targets last year.

In October, it emerged that Trump had authorized the payment of $25 million in overdue subscriptions to the WTO, despite the administration deriding the organization as “toothless” only a month previously.

The list also did not include the International Maritime Organization despite the Trump administration’s successful—and diplomatically bruising—move last year to block the IMO’s plan to introduce a net zero framework for shipping.

Sue Biniaz, the former US climate negotiator, said she hoped the retreat from the UNFCCC treaty was “a temporary one,” adding there were “multiple future pathways to rejoining the key climate agreements” in future.

Stiell of the UNFCCC agreed: “The doors remain open for the US to re-enter in the future, as it has in the past with the Paris Agreement. Meanwhile the size of the commercial opportunity in clean energy, climate resilience, and advanced electrotech remains too big for American investors and businesses to ignore.”

He added: “While all other nations are stepping forward together, this latest step back from global leadership, climate co-operation, and science can only harm the US economy, jobs, and living standards, as wildfires, floods, megastorms, and droughts get rapidly worse.”

Trump withdraws US from world’s most important climate treaty Read More »

Japanese nuclear plant operator fabricated seismic risk data

earthquakes, falsification, fraud, Fukushima, Japan, nuclear power, nuclear safety, Science, seismic risk / Mike M. / January 7, 2026

On Wednesday, Japan’s Nuclear Regulation Authority announced that it is halting the relicensing process for two reactors at the Hamaoka plant after revelations that the operator fabricated seismic hazard data. Japan has been slowly reactivating its extensive nuclear power plant collection after it was shut down following the Fukushima Daiichi disaster. The latest scandal is especially shocking, given that the Hamaoka plant is located on the coast near an active subduction fault—just as Fukushima Daiichi is.

The Nuclear Regulation Authority was reportedly alerted by a whistleblower in February of last year, but the issue became public this week when the regulators halted an evaluation process that could have led to a reactor restart at Hamaoka. This prompted the company that operates the plants, the Chubu Electric Power Co., to issue a press release describing in detail how the company manipulated the seismic safety data.

Based on an English translation, it appears that seismic risks were evaluated at least in part by scaling up the ground motion using data from smaller earthquakes. This is an inexact process, so the standard approach is to create a group of 20 different upscaled earthquake motions and find the one that best represents the average among the 20.

The company now acknowledges that since 2018, its staff has been generating large collections of upscaled earthquake scenarios, choosing one from among them, and then selecting another 19 so the average would make that event appear representative. The company does not mention how this process affected risk analysis, but it’s probably safe to assume that it was chosen specifically to make any risks seem more tolerable.

Japanese nuclear plant operator fabricated seismic risk data Read More »

New battery idea gets lots of power out of unusual sulfur chemistry

anode, batteries, cathode, chemistry, materials science, Science, sodium, sulfur / Shannon Garcia / January 7, 2026

When the battery starts discharging, the sulfur at the cathode starts losing electrons and forming sulfur tetrachloride (SCl₄), using chloride it stole from the electrolyte. As the electrons flow into the anode, they combine with the sodium, which plates onto the aluminum, forming a layer of sodium metal. Obviously, this wouldn’t work with an aqueous electrolyte, given how powerfully sodium reacts with water.

High capacity

To form a working battery, the researchers separated the two electrodes using a glass fiber material. They also added a porous carbon material to the cathode to keep the sulfur tetrachloride from diffusing into the electrolyte. They used various techniques to confirm that sodium was being deposited on the aluminum and that the reaction at the cathode was occurring via sulfur dichloride intermediates. They also determined that sodium chloride was a poor source of sodium ions, as it tended to precipitate out onto some of the solid materials in the battery.

The battery was also fairly stable, surviving 1,400 cycles before suffering significant capacity decay. Higher charging rates caused capacity to decay more quickly, but the battery does a great job of holding charge when not in use, maintaining over 95 percent of its charge, even when idled for 400 days.

While the researchers provide some capacity-per-weight measurements, they don’t do so for a complete battery, focusing instead on portions of the battery, such as the sulfur or the total electrode mass.

But with both electrodes considered, the energy density can reach over 2,000 Watt-hours per kilogram. While that will undoubtedly drop with the total mass of the battery, it’s difficult to imagine that it wouldn’t outperform existing sodium-sulfur or sodium-ion batteries.

Beyond the capacity, the big benefit of the proposed system appears to be its price. Given the raw materials, the researchers estimate that their cost is roughly $5 per kilowatt-hour of capacity, which is less than a tenth of the cost of current sodium batteries.

Again, there’s no guarantee that this work can be scaled up for manufacturing in a way that keeps it competitive with current technologies. Still, if materials used in existing battery technologies become expensive, it’s reassuring to have other options to explore.

Nature, 2026. DOI: 10.1038/s41586-025-09867-2 (About DOIs).

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We have a fossil closer to our split with Neanderthals and Denisovans

anthropology, Archaeology, Denisovans, hominins, homo erectus, human evolution, Neanderthals, paleoanthropology, Science / 9u50fv / January 7, 2026

The Casablanca fossils are about the same age as hominin fossils from Spain, which belong to a species called Homo antecessor. This species has been suggested to be a likely ancestor of Neanderthals and Denisovans. Overall, it looks like the fossils from Casablanca are a North African counterpart to Homo antecessor, with the Spanish hominins eventually leading to Neanderthals and the North African ones eventually leading to us.

Both groups share some features in their teeth and lower jaws, but they’re also different in some important ways. The teeth and chins in particular share some older features with Homo erectus. But the jaws have more newfangled features in the places where chewing muscles once attached to the bone—features that Neanderthals and our species share. On the other hand, the teeth are missing some other relatively recent features that would later help define Neanderthals (and were already beginning to show up in Homo antecessor).

Altogether, it looks like the Homo erectus populations and the Neanderthals and Denisovans had been separated for a while by the time the hominins at Grotte à Hominidés lived. But not that long. These hominins were probably part of a generation that was fairly close to that big split, near the base of our branch of the hominin family tree.

Here’s looking at you, hominin

Based on ancient DNA, it looks like Neanderthals and Denisovans started evolving into two separate species sometime between 470,000 and 430,000 years ago. Meanwhile, our branch would eventually become recognizable as us sometime around 300,000 years ago, or possibly earlier. At various times and places, all three species would eventually come back together to mingle and swap DNA, leaving traces of those interactions buried deep in each other’s genomes.

And 773,000 years after a predator dragged the remains of a few unfortunate hominins into its den in northern Africa, those hominins’ distant descendants would unearth the gnawed, broken bones and begin piecing together the story.

Nature, 2025 DOI: 10.1038/s41586-025-09914-y (About DOIs).

We have a fossil closer to our split with Neanderthals and Denisovans Read More »

Appeals court agrees that Congress blocked cuts to research costs

Appeals court, Grant funding, indirect costs, NIH, Policy, Science / DJ Henderson / January 6, 2026

While indirect rates (the money paid for indirects as a percentage of the money that goes directly to the researcher to support their work) average about 30 percent, many universities have ended up with indirect cost rates above 50 percent. A sudden and unexpected drop to the 15 percent applied retroactively, as planned by the Trump administration, would create serious financial problems for major research universities.

The district court’s initial ruling held that this change was legally problematic in several ways. It violated the Administrative Procedures Act by being issued without any notice or comment, and the low flat rate was found to be arbitrary and capricious, especially compared to the system it was replacing. The ruling determined that the new policy also violated existing procedures within the Department of Health and Human Services.

But the Appeals Court panel of three judges unanimously determined that they didn’t even have to consider all of those issues because Congress had already prohibited exactly this action. In 2017, the first Trump administration also attempted to set all indirect costs to the same low, flat fee, and Congress responded by attaching a rider to a budget agreement that blocked alterations to the NIH overhead policy. Congress has been renewing that rider ever since.

A clear prohibition

In arguing for its new policy, the government tried to present it as consistent with Congress’s prohibition. The rider allowed some exceptions to the normal means of calculating overhead rates, but they were extremely limited; the NIH tried to argue that these exceptions could include every single grant issued to a university, something the court found was clearly inconsistent with the limits set by Congress.

The court also noted that, as announced, the NIH policy applied to every single grant, regardless of whether the recipient was at a university—something it later contended was a result of “inartful language.” But the judges wrote that it’s a bit late to revise the policy, saying, “We cannot, of course, disregard what the Supplemental Guidance actually says in favor of what NIH now wishes it said.”

Appeals court agrees that Congress blocked cuts to research costs Read More »

orsted-seeks-injunction-against-us-government-over-project-freeze

Ørsted seeks injunction against US government over project freeze

orsted, Policy, Science, syndication, wind farm / Kelly Newman / January 6, 2026

In October, Ørsted raised $9 billion from investors in a rights issue after Trump’s attempts to block a rival developer’s project spooked investors.

The US government then issued a stop-work order against the company’s $1.5 billion Revolution Wind project off the coast of Rhode Island, although Ørsted has persuaded a judge to lift the order.

In November, Ørsted agreed to sell half of the world’s largest offshore wind farm to Apollo in a $6.5 billion deal. Then on December 22, the company received orders from the US government to suspend “all ongoing activities on the outer continental shelf for the next 90 days.”

According to the company, the Revolution Wind project is now about 87 percent complete, with 58 out of its 65 wind turbines installed.

While Trump has made Ørsted’s planned offshore wind projects in the US far more difficult, its troubles predate his administration.

In 2023, the company had to walk away from two large projects in the US because of rising costs that have affected the entire industry.

In a statement on Ørsted’s legal challenge, White House spokesperson Taylor Rogers said: “For years, Americans have been forced to pay billions more for the least reliable source of energy. The Trump administration has paused the construction of all large-scale offshore wind projects because our number one priority is to put America First and protect the national security of the American people.”

Ørsted seeks injunction against US government over project freeze Read More »

NASA’s science budget won’t be a train wreck after all

NASA, Science, Space, trump budget / Kelly Newman / January 5, 2026

“Those hours could have been spent running and analyzing data from these valuable missions,” Dreier said. “It created a lot of needless friction and churn at a time when NASA is being told it must remain competitive with China and other nations in space.”

Budget likely to be signed soon

The House of Representatives could vote on the budget bill for Commerce, Justice, Science, and Related Agencies as soon as this week, with the US Senate possibly following next week. It is expected that President Trump will sign the bill. It would then go into effect immediately for the current fiscal year, which began on October 1.

The biggest casualty in the NASA science budget is the Mars Sample Return mission, a NASA-led effort to return Martian rocks and soil for study in Earth-based laboratories.

“As proposed in the budget, the agreement does not support the existing Mars Sample Return (MSR) program,” the budget document states. “However, the technological capabilities being developed in the MSR program are not only critical to the success of future science missions but also to human exploration of the Moon and Mars.”

Although it offers no details, the budget provides $110 million for something called the “Mars Future Missions” program to support “radar, spectroscopy, entry, descent, and landing systems.”

Some hope for future missions, too

NASA previously said it was pausing the ambitious sample return mission because its projected cost was approximately $10 billion, with no certain return date for the samples.

Now it seems likely that the agency and its new administrator, Jared Isaacman, will have to develop a new strategy. This may include sending humans to Mars, rather than bringing Martian rocks back to Earth.

Unlike the Trump budget request, the science budget also keeps future missions, such as the DAVINCI probe for Venus, alive. It also provides $10 million to continue studying the development of a Uranus orbiter, as well as $150 million for a flagship telescope to search for signs of life on nearby, Earth-like planets called the Habitable Worlds Observatory.

NASA’s science budget won’t be a train wreck after all Read More »

Under anti-vaccine RFK Jr., CDC slashes childhood vaccine schedule

anti-vaccine, health, robert f kennedy jr, Science, vaccine / Shannon Garcia / January 5, 2026

Under anti-vaccine Health Secretary Robert F. Kennedy Jr., federal health officials on Monday announced a sweeping and unprecedented overhaul of federal vaccine recommendations, abruptly paring down recommended immunizations for children from 17 to 11.

Officials claimed the rationale for the change was to align US vaccine recommendations more closely with those of other high-income countries, namely Denmark, a small, far less diverse country of around 6 million people (smaller than the population of New York City) that has universal health care. The officials also claim the change is necessary to address the decline in public trust in vaccinations, which has been driven by anti-vaccine activists, including Kennedy.

“This decision protects children, respects families, and rebuilds trust in public health,” Kennedy said in a statement.

Health experts disagree. “Kennedy’s decision will harm and kill children, like all of his anti-vaccination decisions will,” virologist James Alwine, who works with the organization Defend Public Health, said in a statement.

The American Academy of Pediatrics, a vocal critic of Kennedy, blasted the changes, saying “to arbitrarily stop recommending numerous routine childhood immunizations is dangerous and unnecessary,” AAP President Andrew Racine said. “The United States is not Denmark,” he added.

Under the new federal recommendations, universally recommended immunizations are pared down to these 11 diseases: measles, mumps, rubella, polio, pertussis (whooping cough), tetanus, diphtheria, Haemophilus influenzae type B (Hib), pneumococcal disease, human papillomavirus (HPV), and varicella (chickenpox).

Under anti-vaccine RFK Jr., CDC slashes childhood vaccine schedule Read More »

Researchers spot Saturn-sized planet in the “Einstein desert”

astronomy, exoplanets, microlensing, rogue planets, Science / 9u50fv / January 2, 2026

Rogue, free-floating planets appear to have two distinct origins.

Most of the exoplanets we’ve discovered have been in relatively tight orbits around their host stars, allowing us to track them as they repeatedly loop around them. But we’ve also discovered a handful of planets through a phenomenon that’s called microlensing. This occurs when a planet passes between the line of sight between Earth and another star, creating a gravitational lens that distorts the star, causing it to briefly brighten.

The key thing about microlensing compared to other methods of finding planets is that the lensing planet can be nearly anywhere on the line between the star and Earth. So, in many cases, these events are driven by what are called rogue planets: those that aren’t part of any exosolar system at all, but they drift through interstellar space. Now, researchers have used microlensing and the fortuitous orientation of the Gaia space telescope to spot a Saturn-sized planet that’s the first found in what’s called the “Einstein desert,” which may be telling us something about the origin of rogue planets.

Going rogue

Most of the planets we’ve identified are in orbit around stars and formed from the disks of gas and dust that surrounded the star early in its history. We’ve imaged many of these disks and even seen some with evidence of planets forming within them. So how do you get a planet that’s not bound to any stars? There are two possible routes.

The first involves gravitational interactions, either among the planets of the system or due to an encounter between the exosolar system and a passing star. Under the right circumstances, these interactions can eject a planet from its orbit and send it hurtling through interstellar space. As such, we should expect them to be like any typical planet, ranging in mass from small, rocky bodies up to gas giants. An alternative method of making a rogue planet starts with the same process of gravitational collapse that builds a star—but in this case, the process literally runs out of gas. What’s left is likely to be a large gas giant, possibly somewhere between Jupiter and a brown dwarf star in mass.

Since these objects are unlinked to any exosolar system, they’re not going to have any regular interactions with stars; our only way of spotting them is through microlensing. And microlensing tells us very little about the size of the planet. To figure things out, we would need some indication of things like how distant the star and planet are, and how big the star is.

That doesn’t mean that microlensing events have told us nothing. We can identify the size of the Einstein ring, the circular ring of light that forms when the planet and star are perfectly lined up from Earth’s perspective. Given that information and some of the remaining pieces of info mentioned above, we can figure out the planet’s mass. But even without that, we can make some inferences using statistical models.

Studies of collections of microlensing events (these collections are small, typically in the dozens, because these events are rare and hard to spot) have identified a distinctive pattern. There’s a cluster of relatively small Einstein rings that are likely to have come from relatively small planets. Then, there’s a gap, followed by a second cluster that’s likely to be made by far larger planets. The gap between the two has been termed the “Einstein desert,” and there has been considerable discussion regarding its significance and whether it’s even real or simply a product of the relatively small sample size.

Sometimes you get lucky

All of which brings us to the latest microlensing event, which was picked up by two projects that each gave it a different but equally compelling name. To the Korea Microlensing Telescope Network, the event was KMT-2024-BLG-0792. For the Optical Gravitational Lensing Experiment, or OGLE, it was OGLE-2024-BLG-0516. We’ll just call it “the microlensing event” and note that everyone agrees that it happened in early May 2024.

Both of those networks are composed of Earth-based telescopes, and so they only provide a single perspective on the microlensing event. But we got lucky that the European Space Agency’s space telescope Gaia was oriented in a way that made it very easy to capture images. “Serendipitously, the KMT-2024-BLG-0792/OGLE-2024-BLG-0516 microlensing event was located nearly perpendicular to the direction of Gaia’s precession axis,” the researchers who describe this event write. “This rare geometry caused the event to be observed by Gaia six times over a 16-hour period.”

Gaia is also located at the L2 Lagrange point, which is a considerable distance from Earth. That’s far enough away that the peak of the events’ brightness, as seen from Gaia’s perspective, occurred nearly two hours later than it did for telescopes on Earth. This let us determine the parallax of the microlensing event, and thus its distance. Other images of the star from before or after the event indicated it was a red giant in the galactic bulge, which also gave us a separate check on its likely distance and size.

Using the parallax and the size of the Einstein ring, the researchers determined that the planet involved was roughly 0.2 times the mass of Jupiter, which makes it a bit smaller than the mass of Saturn. Those estimates are consistent with a statistical model that took the other properties into account. The measurements also placed it squarely in the middle of the Einstein desert—the first microlensing event we’ve seen there.

That’s significant because it means we can orient the Einstein desert to a specific mass of a planet within it. Because of the variability of things like distance and the star’s size, not every planet that produces a similar-sized Einstein ring will be similar in size, but statistics suggest that this will typically be the case. And that’s in keeping with one of the potential explanations for the Einstein desert: that it represents the gap in size between the two different methods of making a rogue planet.

For the normal planet formation scenario, the lighter the planet is, the easier it is to be ejected, so you’d expect a bias toward small, rocky bodies. The Saturn-sized planet seen here may be near the upper limit of the sorts of bodies we’d typically see being ejected from an exosolar system. By contrast, the rogue planets that form through the same mechanisms that give us brown dwarfs would typically be Jupiter-sized or larger.

That said, the low number of total microlensing events still leaves the question of the reality of the Einstein gap an open question. Sticking with the data from the Korea Microlensing Telescope Network, the researchers find that the frequency of other detections suggests that we’d have a 27 percent chance of detecting just one item in the area of the Einstein desert even if the desert wasn’t real and detections were equal probably across the size range. So, as is often the case, we’re going to need to let the network do its job for a few years more before we have the data to say anything definitive.

Science, 2026. DOI: 10.1126/science.adv9266 (About DOIs).

John is Ars Technica’s science editor. He has a Bachelor of Arts in Biochemistry from Columbia University, and a Ph.D. in Molecular and Cell Biology from the University of California, Berkeley. When physically separated from his keyboard, he tends to seek out a bicycle, or a scenic location for communing with his hiking boots.

Researchers spot Saturn-sized planet in the “Einstein desert” Read More »

Research roundup: 7 cool science stories we almost missed

research roundup, Science / 9u50fv / January 1, 2026

Double-detonating “superkilonova,” Roman liquid gypsum burials, biomechanics of kangaroo posture, and more.

Three stages of a superkilonova: a supernova blast, neutron star merger, and finally kilonova that spews heavy metals. Credit: Caltech/K. Miller and R. Hurt (IPAC)

It’s a regrettable reality that there is never enough time to cover all the interesting scientific stories we come across each month. In the past, we’ve featured year-end roundups of cool science stories we (almost) missed. This year, we’ve experimented with a monthly collection. December’s list includes a fossilized bird that choked to death on rocks; a double-detonating “superkilonova”; recovering an ancient seafarer’s fingerprint; the biomechanics of kangaroo movement; and cracking a dark matter puzzle that stumped fictional physicists on The Big Bang Theory, among other tantalizing tidbits

Secrets of kangaroo posture

An illustration of the 3D musculoskeletal model of a kangaroo, developed by Lauren Thornton and colleagues.

Kangaroos and wallabies belong to a class of animals called macropods, with unique form and style of movement. Their four limbs and tail all contact the ground at slow speeds, while they use a hopping gait at higher speeds. Typically, high-speed movements are more energy-intensive than slow-speed motion, but the opposite is true for macropods like kangaroos; somehow the hopping speed and energy cost become uncoupled. According to a paper published in the journal eLife, this may be due to changes in a kangaroo’s posture at higher hopping speeds.

To investigate their hypothesis, the authors used 3D motion capture and data from force plates to create a 3D musculoskeletal model to analyze the motions of red and grey kangaroos, focusing on how body mass and speed influence three factors during hopping: hindlimb posture, efficiency of movement and associated tendon stress; and the ankles. This revealed that kangaroos adjust their posture so that the hindlimbs are more crouched while hopping, with the ankle joint doing most of the work per hop. The crouching position increases energy absorption, thus improving efficiency.

DOI: eLife, 2025. 10.7554/eLife.96437.3 (About DOIs).

Fossilized bird choked on rocks

unlucky fossil bird, preserved with over 800 tiny rocks in its throat (visible as the gray mass next to the left of its neck bones). — Credit: Jingmai O’Connor

Some 120 million years ago, a tiny bird choked to death on a bunch of small rocks lodged in its throat. Paleontologists recently discovered the fossil among the many specimens housed at the Shandong Tianyu Museum of Nature in China. Not only does it represent a new species—dubbed Chromeornis funkyi, after techno-funk duo Chromeo—the fossilized bird is the first such specimen to be found with a throat filled with stones, according to a paper published in the journal Palaeontologica Electronica.

Certain bird species, like chickens, swallow small stones and store them in their gizzards to help grind up food. The authors examined prior CT scans of fossilized birds with gizzards and quantified how many gizzard stones were present, then compared that data to a CT scan of the C. funkyi fossil. The scan showed that the more than 800 tiny stones lodged in the throat were not gizzard stones. So the bird didn’t swallow the stones to help grind up food. The authors suggest the bird was sick; sick birds will sometimes eat stones. When it tried to regurgitate the stones, they got stuck in the esophagus and the poor bird choked to death.

DOI: Palaeontologica Electronica, 2025. 10.26879/1589 (About DOIs).

“Superkilonova” exploded twice

Back in 2017, astronomers detected a phenomenon known as a “kilonova”: the merger of two neutron stars accompanied by powerful gamma-ray bursts. Recording this kind of celestial event was unprecedented, and it officially marked the dawn of a new era in so-called “multi-messenger astronomy.” It’s the only unambiguously confirmed kilonova to date, but astrophysicists reported evidence of a possible second such event in a paper published in The Astrophysical Journal Letters. And it’s unusual because this kilonova may have originated from a supernova blast mere hours before, making it a “superkilonova.”

Supernovae are the spectacular explosions that result from dying massive stars, seeding the universe with heavy elements like carbon and iron. Kilonovae occur when two binary neutron stars begin circling into their death spiral, sending out powerful gravitational waves and stripping neutron-rich matter from each other. Then the stars collide and merge, producing a hot cloud of debris that glows with light of multiple wavelengths. It’s the neutron-rich debris that astronomers believe creates a kilonova’s visible and infrared light—the glow is brighter in the infrared than in the visible spectrum, a distinctive signature that results from heavy elements in the ejecta that block visible light but let the infrared through.

This latest kilonova candidate event, dubbed AT2025ulz, initially looked like the 2017 event, but over time, its properties started resembling a supernova, making it less interesting to many astronomers. But it wasn’t a classic supernova either. So some astronomers kept tracking the event and analyzing combined “multimessenger” data from other collaborations and telescopes during the same time frame. They concluded that this was a multi-stage event: specifically, a supernova gave birth to twin baby neutron stars, which then merged to produce a kilonova. That said, the evidence isn’t quite strong enough to claim this is what definitely happened; astronomers need to find more such superkilnova to confirm.

DOI: Astrophysical Journal Letters, 2025. 10.3847/2041-8213/ae2000 (About DOIs).

An ancient seafarer’s fingerprint

Photo of caulking fragment showing fingerprint on the left and high-resolution x-ray tomography scan of fingerprint region on the right. — Credit: Photography by Erik Johansson, 3D model by Sahel Ganji

In the 4th century BCE, an invading mini-armada of about four boats attacked an island off the coast of Denmark. The attack failed and the victorious islanders celebrated by sinking one of the boats, filled with their foes’ weapons, into a bog, where it remained until it was discovered by archaeologists in the 1880s. It’s known as the Hjortspring boat, and archaeologists were recently surprised when their analysis uncovered an intact human fingerprint in the tars used to waterproof the vessel. They described their find in a paper published in the journal PLoS ONE.

The fingerprint is significant because it offers a hint into where those would-be raiders from the sea originally hailed from. Prior scholars had suggested they came from somewhere near what is now Hamburg, Germany. But the authors of this latest paper noticed that the waterproofing tars were pine pitch, concluding that the raiders may have originated in the coastal regions of the Baltic Sea, along which pine-rich forests flourished. That would require the raiders to travel over hundreds of kilometers of open sea. The authors hope they can extract some ancient DNA from the tar to learn more about the ancient people who built the boat.

DOI: PLoS ONE, 2025. 10.1371/journal.pone.0336965 (About DOIs).

Roman liquid gypsum burials

The impression of fingers preserved in the gypsum surface. — Credit: Seeing the Dead Project/University of York/York Museums Trust

Speaking of ancient fingerprints, archaeologists at the University of York found finger marks and fingerprints preserved in hardened gypsum used by Romans in Britain in their funerary practices in the third and fourth centuries CE. The university is home to the Seeing the Dead project, which studies the bodies preserved by pouring liquid gypsum (plaster of paris) over them in their coffins prior to burial. The gypsum hardened around the decomposing bodies, creating a cavity while preserving clear imprints of the body contours, clothing, and shrouding. It’s similar to the method used to create casts of the victims of Pompeii.

Some 70 gypsum burials have been found in Yorkshire thus far. In this case, researchers were examining a stone sarcophagus excavated in the 1870s that had yet to be analyzed. While cleaning the artifact and subjecting it to 3D scanning, they noticed a handprint with fingers clearly delineated in the hardened gypsum. They also found distinct fingerprints close to the edges of the coffin. The team had previously thought that the gypsum was heated to at least 300 degrees F (150 degrees C) before being poured over the body, but the handprint and fingerprints suggests someone had smoothed the gypsum over the body by hand, suggesting significantly cooler temperatures. While acknowledging it’s a long shot, the team hopes to extract DNA samples from the sarcophagus which might enable them to determine genetic sex.

Playing Super Mario combats burnout

Cheerful landscape in Super Mario Bros. Wonder — Credit: Winze Tam et al./Ninetendo

Young adulthood in the 2020s is fraught with a range of interconnected pressures: soaring cost of living, student loan debt, pressure to excel academically, and an “always on” digital culture, to name a few of the most common stressors. This in turn can lead to burnout. Perhaps playing video games can help—the right kind of video games, like Super Mario Bros. or Yoshi., as opposed to dystopian survival horror games or highly competitive multiplayer games. According to a study published in the journal JMIR Serious Games, Super Mario Bros. and Yoshi can help young adults recapture childlike wonder and reduce stress and anxiety that can lead to burnout.

The authors employed a mixed-methods approach for their study. First, they collected qualitative data from 41 college-aged subjects via in-depth interviews; all were experienced players of those two games. They followed this with a cross-sectional survey to collect quantitative data from 336 players. The resulting analysis showed that those who felt greater childlike wonder while playing also reported higher overall happiness; and the happiest players showed significantly lower risk of burnout. “By moving beyond escapism and nostalgia, [this study] offers a new perspective on how well-designed, globally familiar games can function as accessible, resilience-building digital microenvironments,” the authors concluded.

DOI: JMIR Serious Games, 2025. 10.2196/84219 (About DOIs).

Cracking a Big Bang Theory problem

Sheldon and Leonard, two nerdy physicists, standing in front of a white board filled with equations and diagrams — Credit: CBS

Physicists may have had mixed feelings about The Big Bang Theory‘s depiction of their profession, but one thing the sitcom consistently got right was the equations featured on the ubiquitous white board—clever Easter eggs for physicists, courtesy of science advisor David Saltzberg. In one episode, Sheldon and Leonard are pondering an equation about how axions are generated from the sun—part of the duo’s efforts to estimate the likelihood of detecting axions produced by a fusion reactor. Leonard and Sheldon failed on that point, but real-world physicists think they’ve now cracked the case, according to a paper published in the Journal of High Energy Physics.

Axions are hypothetical particles that could explain dark matter— the mysterious substance that comprises about 23 percent of all the mass in our universe—and represent a theoretical alternative to WIMPs, which thus far have eluded detection by physicists. Particles can exhibit wavelike behavior as well as particle characteristics. So an axion would behave more like a wave (or wave packet) than a particle, and the size of the wave packets is inversely proportional to their mass. That means these very light particles don’t necessarily need to be tiny. The downside is that they interact even more weakly with regular matter than WIMPS, so they cannot be produced in large colliders.

So physicists have been developing all kinds of smaller experiments for detecting axions, from atomic clocks and resonating bars, to shining lasers at walls on the off-chance a bit of dark matter seeps through the other side. Co-author Jure Zupan of the University of Cincinnati and colleagues proposed that axions could be produced by a fusion reactor powered by deuterium and tritium contained in a lithium-lined vessel. Among the fusion byproducts of such a reactor would be a large flux of neutrons which would interact with materials in the walls, or collide with other particles, thereby releasing energy and creating new particles: possibly axions or axion-like particles.

DOI: Journal of High Energy Physics, 2025. 10.1007/JHEP10(2025)215 (About DOIs).

Jennifer is a senior writer at Ars Technica with a particular focus on where science meets culture, covering everything from physics and related interdisciplinary topics to her favorite films and TV series. Jennifer lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.

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Here we go again: Retiring coal plant forced to stay open by Trump Admin

coal, department of energy, Energy, pollution, Science, Trump / Beth Washington / December 31, 2025

On Tuesday, US Secretary of Energy Chris Wright issued a now familiar order: because of a supposed energy emergency, a coal plant scheduled for closure would be forced to remain open. This time, the order targeted one of the three units present at Craig Station in Colorado, which was scheduled to close at the end of this year. The remaining two units were expected to shut in 2028.

The supposed reason for this order is an emergency caused by a shortage of generating capacity. “The reliable supply of power from the coal plant is essential for keeping the region’s electric grid stable,” according to a statement issued by the Department of Energy. Yet the Colorado Sun notes that Colorado’s Public Utilities Commission had already analyzed the impact of its potential closure, and determined, “Craig Unit 1 is not required for reliability or resource adequacy purposes.”

The order does not require the plant to actually produce electricity; instead, it is ordered to be available in case a shortfall in production occurs. As noted in the Colorado Sun article, actual operation of the plant would potentially violate Colorado laws, which regulate airborne pollution and set limits on greenhouse gas emissions. The cost of maintaining the plant is likely to fall on the local ratepayers, who had already adjusted to the closure plans.

The use of emergency powers by the DOE is authorized under the Federal Power Act, which allows it to order the temporary connection of generation or infrastructure when the US is at war or when “an emergency exists by reason of a sudden increase in the demand for electric energy, or a shortage of electric energy.” It is not at all clear whether “we expect demand to go up in the future,” the DOE’s current rationale, is consistent with that definition of emergency. It is also hard to see how using coal plants complies with other limits placed on the use of these emergency orders:

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The science of how (and when) we decide to speak out—or self-censor

censorship, Human behavior, mathematical modeling, psychology, Science, Social Media / 9u50fv / December 30, 2025

The US has adopted more of a middle ground approach, essentially letting private companies decide what they wanted to do. Daymude and his co-authors wanted to investigate these markedly different approaches. So they developed a computational agent-based simulation that modeled how individuals navigate between wanting to express dissent versus fear of punishment. The model also incorporates how an authority adjusts its surveillance and its policies to minimize dissent at the lowest possible cost of enforcement.

“It’s not some kind of learning theory thing,” said Daymude. “And it’s not rooted in empirical statistics. We didn’t go out and ask 1000 people, ‘What would you do if faced with this situation? Would you dissent or self-censor?’ and then build that data into the model. Our model allows us to embed some assumptions about how we think people behave broadly, but then lets us explore parameters. What happens if you’re more or less bold? What happens if punishments are more or less severe? An authority is more or less tolerant? And we can make predictions based on our fundamental assumptions about what’s going to happen.”

Let one hundred flowers bloom

According to their model, the most extreme case is an authoritarian government that adopts a draconian punishment strategy, which effectively represses all dissent in the general population. “Everyone’s best strategic choice is just to say nothing at this point,” said Daymude. “So why doesn’t every authoritarian government on the planet just do this?” That led them to look more closely at the dynamics. “Maybe authoritarians start out somewhat moderate,” he said. “Maybe the only way they’re allowed to get to that extreme endpoint is through small changes over time.”

Daymude points to China’s Hundred Flowers Campaign in the 1950s as an illustrative case. Here, Chairman Mao Zedong initially encouraged open critiques of his government before abruptly cracking down aggressively when dissent got out of hand. The model showed that in such a case, dissenters’ self-censorship gradually increased, culminating in near-total compliance over time.

But there’s a catch. “The opposite of the Hundred Flowers is if the population is sufficiently bold, this strategy doesn’t work,” said Daymude. “The authoritarian can’t find the pathway to become fully draconian. People just stubbornly keep dissenting. So every time it tries to ramp up severity, it’s on the hook for it every time because people are still out there, they’re still dissenting. They’re saying, ‘Catch us if you dare.’”

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