"A spectacular trove of fossils discovered in a cave on New Zealand's North Island has given scientists their first glimpse of ancient forest species that lived there more than a million years ago," reports Popular Mechanics: The fossils represent 12 ancient bird species and four frog species, including several previously unknown bird species. Taken together, the fossils paint a picture of an ancient world that looks drastically different than it does today. The discovery also fills in an important gap in scientific understanding of the patterns of extinction that preceded human arrival in New Zealand 750 years ago. The team published a study on the find in Alcheringa: An Australasian Journal of Palaeontology. Trevor Worthy, lead study author and associate professor at Flinders University, said in a statement that "This remarkable find suggests our ancient forests were once home to a diverse group of birds that did not survive the next million years... "For decades, the extinction of New Zealand's birds was viewed primarily through the lens of human arrival 750 years ago. This study proves that natural forces like super-volcanoes and dramatic climate shifts were already sculpting the unique identity of our wildlife over a million years ago." Thanks to long-time Slashdot reader fahrbot-bot for sharing the article.

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2001: "Brookhaven Labs has produced for the first time collisions of gold nuclei at a center of mass energy of 200GeV/nucleon." 2002: "There may be a new type of matter according to researchers at Brookhaven National Laboratory." 2010: The hottest man-made temperatures ever achived were a record 4 trillion degree plasma experiment at Brookhaven National Laboratory in New York... anointed the Guinness record holder." 2023: "Scientists at Brookhaven National Laboratory have uncovered an entirely new kind of quantum entanglement." 2026: On Friday, February 6, "a control room full of scientists, administrators and members of the press gathered" at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab in Upton, New York to witness its final collisions, reports Scientific American: The vibe had been wistful, but the crowd broke into applause as Darío Gil, the Under Secretary for Science at the U.S. Department of Energy, pressed a red button to end the collider's quarter-century saga... "I'm really sad" [said Angelika Drees, a BNL accelerator physicist]. "It was such a beautiful experiment and my research home for 27 years. But we're going to put something even better there." That "something" will be a far more powerful electron-ion collider to further push the frontiers of physics, extend RHIC's legacy and maintain the lab's position as a center of discovery. This successor will be built in part from RHIC's bones, especially from one of its two giant, subterranean storage rings that once held the retiring collider's supply of circulating, near-light speed nuclei...slated for construction over the next decade. [That Electron-Ion Collider, or EIC] will utilize much of RHIC's infrastructure, replacing one of its ion rings with a new ring for cycling electrons. The EIC will use those tiny, fast-flying electrons as tiny knives for slicing open the much larger gold ions. Physicists will get an unrivaled look into the workings of quarks and gluons and yet another chance to grapple with nature's strongest force. "We knew for the EIC to happen, RHIC needed to end," says Wolfram Fischer, who chairs BNL's collider-accelerator department. "It's bittersweet." EIC will be the first new collider built in the US since RHIC. To some, it signifies the country's reentry into a particle physics landscape it has largely ceded to Europe and Asia over the past two decades. "For at least 10 or 15 years," says Abhay Deshpande, BNL's associate laboratory director for nuclear and particle physics, "this will be the number one place in the world for [young physicists] to come." The RHIC was able "to separately send two protons colliding with precisely aligned spins — something that, even today, no other experiment has yet matched," the article points out: During its record-breaking 25-year run, RHIC illuminated nature's thorniest force and its most fundamental constituents. It created the heaviest, most elaborate assemblages of antimatter ever seen. It nearly put to rest a decades-long crisis over the proton's spin. And, of course, it brought physicists closer to the big bang than ever before... When RHIC at last began full operations in 2000, its initial heavy-ion collisions almost immediately pumped out quark-gluon plasma. But demonstrating this beyond a shadow of a doubt proved in some respects more challenging than actually creating the elusive plasma itself, with the case for success strengthening as RHIC's numbers of collisions soared. By 2010 RHIC's scientists were confident enough to declare that the hot soup they'd been studying for a decade was hot and soupy enough to convincingly constitute a quark-gluon plasma. And it was even weirder than they thought. Instead of the gas of quarks and gluons theorists expected, the plasma acted like a swirling liquid unprecedented in nature. It was nearly "perfect," with zero friction, and set a new record for twistiness, or "vorticity." For Paul Mantica, a division director for the Facilities and Project Management Division in the DOE's Office of Nuclear Physics, this was the highlight of RHIC's storied existence. "It was paradigm-changing," he says... Data from the final run (which began nearly a year ago) has already produced yet another discovery: the first-ever direct evidence of "virtual particles" in RHIC's subatomic puffs of quark-gluon plasma, constituting an unprecedented probe of the quantum vacuum. RHIC's last run generated hundreds of petabytes of data, the article points out, meaning its final smash "isn't really the end; even when its collisions stop, its science will live on." But Science News notes RHIC's closure "marks the end for the only particle collider operating in the United States, and the only collider of its kind in the world. Most particle accelerators are unable to steer two particle beams to crash head-on into one another."

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Ultra-processed foods (UPFs) have more in common with cigarettes than with fruit or vegetables, and require far tighter regulation, according to a new report. The Guardian: UPFs and cigarettes are engineered to encourage addiction and consumption, researchers from three US universities said, pointing to the parallels in widespread health harms that link both. UPFs, which are widely available worldwide, are food products that have been industrially manufactured, often using emulsifiers or artificial colouring and flavours. The category includes soft drinks and packaged snacks such as crisps and biscuits. There are similarities in the production processes of UPFs and cigarettes, and in manufacturers' efforts to optimise the "doses" of products and how quickly they act on reward pathways in the body, according to the paper from researchers at Harvard, the University of Michigan and Duke University. They draw on data from the fields of addiction science, nutrition and public health history to make their comparisons, published on 3 February in the healthcare journal the Milbank Quarterly. The authors suggest that marketing claims on the products, such as being "low fat" or "sugar free," are "health washing" that can stall regulation, akin to the advertising of cigarette filters in the 1950s as protective innovations that "in practice offered little meaningful benefit."

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Scientists at the University of Utah have analyzed nearly a century's worth of human hair samples and found that lead concentrations dropped 100-fold after the EPA began cracking down on leaded gasoline and other lead-based products in the 1970s. The findings, published in the Proceedings of the National Academy of Sciences, drew on hair collected from Utah residents -- some preserved in family scrapbooks going back generations. Lead levels peaked between 1916 and 1969 at around 100 parts per million, fell to 10 ppm by 1990, and dropped below 1 ppm by 2024. The decline largely tracks the phase-out of leaded gasoline after President Nixon established the EPA in 1970; before the agency acted, most gasolines contained about 2 grams of lead per gallon, releasing nearly 2 pounds of lead per person into the environment each year. The study arrives amid the Trump administration's broader push to scale back the EPA. Lead regulations have not yet been targeted, but the authors note concerns about loosened enforcement of the 2024 Lead and Copper rule on replacing old lead pipes.

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Slashdot reader alternative_right writes: Quantum computers need extreme cold to work, but the very systems that keep them cold also create noise that can destroy fragile quantum information. Scientists in Sweden have now flipped that problem on its head by building a tiny quantum refrigerator that actually uses noise to drive cooling instead of fighting it. By carefully steering heat at unimaginably small scales, the device can act as a refrigerator, heat engine, or energy amplifier inside quantum circuits.

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The preprint repository arXiv will require all submissions to be written in English or accompanied by a full English translation starting February 11, a policy change that explicitly permits the use of AI translators even as research suggests large language models remain inconsistent at the task. Until now, authors only needed to submit an abstract in English. ArXiv hosts nearly 3 million preprints and receives more than 20,000 submissions monthly, though just 1% are in languages other than English. Ralph Wijers, chair of arXiv's editorial advisory council, advises authors to verify any AI-generated translations. "Our own experience is that AI translation is good but not good enough," he says. A 2025 study from ByteDance Seed and Peking University ranked 20 LLMs on translation quality between Chinese and English; GPT-5-high scored nearly 77, just below the human expert benchmark of 80, but most models including GPT-4o, Claude 4, and Deepseek-V3 scored under 60.

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Scientific American's Elizabeth Anne Brown recently "polled the great art houses of Europe" about whether they'd had any recent experiences with mold in their collections. Despite the stigma that keeps many institutions silent, she found that extremophile "xerophilic" molds are quietly spreading through museums and archives, thriving in low-humidity, tightly sealed storage and damaging everything from textiles and wood to manuscripts and stone. An anonymous Slashdot reader shares an excerpt from the article: Mold is a perennial scourge in museums that can disfigure and destroy art and artifacts. [...] Consequently, mold is spoken of in whispers in the museum world. Curators fear that even rumors of an infestation can hurt their institution's funding and blacklist them from traveling exhibitions. When an infestation does occur, it's generally kept secret. The contract conservation teams that museums hire to remediate invasive mold often must vow confidentiality before they're even allowed to see the damage. But a handful of researchers, from in-house conservators to university mycologists, are beginning to compare notes about the fungal infestations they've tackled in museum storage depots, monastery archives, crypts and cathedrals. A disquieting revelation has emerged from these discussions: there's a class of molds that flourish in low humidity, long believed to be a sanctuary from decay. By trying so hard to protect artifacts, we've accidentally created the "perfect conditions for [these molds] to grow," says Flavia Pinzari, a mycologist at the Council of National Research of Italy. "All the rules for conservation never considered these species." These molds -- called xerophiles -- can survive in dry, hostile environments such as volcano calderas and scorching deserts, and to the chagrin of curators across the world, they seem to have developed a taste for cultural heritage. They devour the organic material that abounds in museums -- from fabric canvases and wood furniture to tapestries. They can also eke out a living on marble statues and stained-glass windows by eating micronutrients in the dust that accumulates on their surfaces. And global warming seems to be helping them spread. Most frustrating for curators, these xerophilic molds are undetectable by conventional means. But now, armed with new methods, several research teams are solving art history cold cases and explaining mysterious new infestations... The xerophiles' body count is rising: bruiselike stains on Leonardo da Vinci's most famous self-portrait, housed in Turin. Brown blotches on the walls of King Tut's burial chamber in Luxor. Pockmarks on the face of a saint in an 11th-century fresco in Kyiv. It's not enough to find and identify the mold. Investigators are racing to determine the limits of xerophilic life and figure out which pieces of our cultural heritage are at the highest risk of infestation before the ravenous microbes set in.

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Early hominins in Europe were creating tools from raw materials hundreds of thousands of years before Homo sapiens arrived there, two new studies indicate, pushing back the established time for such activity. From a report: The evidence includes a 500,000-year-old hammer made of elephant or mammoth bone, excavated in southern England, and 430,000-year-old wooden tools found in southern Greece -- the earliest wooden tools on record. The findings suggest that early humans possessed sophisticated technological skills, the researchers said. Katerina Harvati, a paleoanthropologist at the University of Tubingen in Germany and a lead author of the wooden-tool paper, which was published on Monday in the journal PNAS, said the discoveries provided insight into the prehistoric origins of human intelligence. Silvia Bello, a paleoanthropologist at London's Natural History Museum and an author on the elephant-bone study, which was published last week in Science Advances, concurred. The artifacts in both studies, recovered from coal-mine sites, were probably produced by early Neanderthals or a preceding species, Homo heidelbergensis. Homo sapiens emerged in Africa more than 300,000 years ago, and the oldest evidence of them in Europe is a 210,000-year-old fossil unearthed in Greece. By the time Homo sapiens established themselves in Britain 40,000 years ago, other hominins had already lived there for nearly a million years.

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OpenAI has launched Prism, a free scientific research app that aims to do for scientific writing what coding agents did for programming. Engadget reports: Prism builds on Crixet, a cloud-based LaTeX platform the company is announcing it acquired today. For the uninitiated, LaTeX is a typesetting system for formatting scientific documents and journals. Nearly the entire scientific community relies on LaTeX, but it can make some tasks, such as drawing diagrams through TikZ commands, time-consuming to do. Beyond that, LaTeX is just one of the software tools a scientist might turn to when preparing to publish their research. That's where Prism comes into the picture. Like Crixet before it, the app offers robust LaTeX editing and a built-in AI assistant. Where previously it was Crixet's own Chirp agent, now it's GPT-5.2 Thinking. OpenAI's model can help with more than just formatting journals -- in a press demo, an OpenAI employee used it to find and incorporate scientific literature that was relevant to the paper they were working on, with GPT-5.2 automating the process of writing the bibliography. [...] Later in the same demo, the OpenAI employee used Prism to generate a lesson plan for a graduate course on general relativity, as well as a set of problems for students to solve. OpenAI envisions these features helping scientists and professors spend less time on the more tedious tasks in their professions.

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Bruce66423 shares a report from the Guardian: New filtration technology developed by Rice University may absorb some Pfas "forever chemicals" at 100 times the rate than previously possible, which could dramatically improve pollution control and speed remediations. Researchers also say they have also found a way to destroy Pfas, though both technologies face a steep challenge in being deployed on an industrial scale. A new peer-reviewed paper details a layered double hydroxide (LDH) material made from copper and aluminum that absorbs long-chain Pfas up to 100 times faster than commonly used filtration systems. [...] [Michael Wong, director of Rice's Water Institute, a Pfas research center] said Rice's non-thermal process works by soaking up and concentrating Pfas at high levels, which makes it possible to destroy them without high temperatures. The LDH material Rice developed is a variation of similar materials previously used, but researchers replaced some aluminum atoms with copper atoms. The LDH material is positively charged and the long-chain Pfas are negatively charged, which causes the material to attract and absorb the chemicals, Wong said. [...] Pfas are virtually indestructible because their carbon atoms are bonded with fluoride, but Rice found that the bonds could be broken if the chemicals in the material were heated to 400-500C -- a relatively low temperature. The fluoride gets trapped in the LDH material and is bonded to calcium. The leftover calcium-fluoride material is safe and can be disposed of in a landfill, Wong said. The process works with some long-chain Pfas that are among the most common water pollutants, and it also absorbed some smaller Pfas that are commonplace. Wong said he is confident the material can be used to absorb a broad array of Pfas, especially if they are negatively charged. Most new Pfas elimination systems fail to work at an industrial scale. Wong said the new material has an advantage because its absorption rate is so strong, it can be used repeatedly and it is in a "drop in material," meaning it can be used with existing filtration infrastructure. That eliminates one of the major cost barriers.

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He Jiankui, the Chinese scientist who served three years in prison after creating the world's first gene-edited babies in 2018, is now preparing for another attempt at germline editing -- this time to prevent Alzheimer's disease. In an interview, He said he has established an independent lab in south Beijing and raised $7 million from private donors to fund research into introducing a protective genetic mutation found in Icelandic populations. The three girls born from his original experiment are now in primary school and healthy, according to He. Since germline editing remains banned in China, He said he plans to conduct future human trials in South Africa and has already spoken with contacts there. He estimates he needs two more years to complete mouse and monkey studies before seeking regulatory approval abroad. He said his lab is developing techniques to make 12 simultaneous genetic edits in a single embryo, targeting genes associated with cancer, cardiovascular disease, HIV, and other conditions. He is currently working on human cell lines and has not yet begun embryo experiments.

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alternative_right shares a report from ScienceAlert: It all started in 1927, when physicist Thomas Parnell at the University of Queensland in Australia filled a closed funnel with the world's thickest known fluid: pitch, a derivative of tar that was once used to seal ships against the seas. Three years later, in 1930, Parnell cut the funnel's stem, like a ribbon at an event, heralding the start of the Pitch Drop Experiment. From then on, the black substance began to flow. At least, that is, in a manner of speaking. At room temperature pitch might look solid, but it is actually a fluid 100 billion times more viscous than water. It took eight years for the first droplet to finally hit the beaker below. Then, they dripped at a cadence of once every eight years or so, slowing down only after air conditioning was installed in the building in the 1980s. Today, 96 years after the funnel was cut, only nine drops in total have seeped out. The last was in 2014. Scientists expect another will fall sometime in the 2020s, but they are still waiting. No one has ever actually seen a droplet fall directly, despite all the watchful eyes. The experiment is now live-streamed, but various glitches in the past meant that each fateful moment has slipped us by.

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Long-time Slashdot reader schwit1 shared this report from Futurism: China has unveiled an extremely powerful "hypergravity machine" that can generate forces almost two thousand times stronger than Earth's regular gravity. The futuristic-looking machine, called CHIEF1900, was constructed at China's Centrifugal Hypergravity and Interdisciplinary Experiment Facility (CHIEF) at Zheijang University in Eastern China, and allows researchers to study how extreme forces affect various materials, plants, cells, or other structures, as the South China Morning Post reports... [Once up and running, it will allow researchers to recreate "catastrophic events such as dam failures and earthquakes inside a laboratory, according to the university."] For instance, it can analyze the structural stability of an almost 1,000-feet-tall dam by spinning a ten-foot model at 100 Gs, meaning 100 times the Earth's regular gravity. It could also be used to study the resonance frequencies of high-speed rail tracks, or how pollutants seep into soil over thousands of years. The machine officially dethroned its predecessor, CHIEF1300, which became the world's most powerful centrifuge a mere four months ago... It can generate 1,900 g-tonnes of force, or 1,900 times the Earth's gravity. To put that into perspective, a washing machine only reaches about two g-tonnes.

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An anonymous reader quotes a report from the Guardian: Even low levels of common agricultural pesticides can stunt the long-term lifespan of fish, according to research led by Jason Rohr, a biologist at the University of Notre Dame in Indiana. Signs of aging accelerated when fish were exposed to the chemicals, according to the study, published in Science, which could have implications for other organisms. [...] The research found that fish from pesticide-affected lakes showed shortened telomeres, the caps at the end of chromosomes that are known as the biological clock for aging. When they shorten, it is a sign of cellular aging and a decline in the body's regenerative capacity. The lake populations consisted of younger fish, indicating that the pesticides contributed to shortened lives. Laboratory experiments confirmed the findings and showed chronic low-dose exposure reduced fish survival and degraded telomeres. These effects were not seen with acute high-dose exposure. Chemical analysis showed chlorpyrifos, which is banned in the UK and the EU but used in the US and China, was the only compound found in the fish tissues that was consistently associated with signs of aging. These included shortened telomeres and lipofuscin deposition -- a buildup of insoluble proteins often described as cellular "junk". The worrying aging effects occurred at concentrations below current US freshwater safety standards, Rohr said, suggesting the effects of chemicals and pesticides could be occurring at low levels over the long term. While short-term exposure to high doses did not appear to cause these aging issues -- though it did cause high toxicity and death in fish -- the researchers concluded that it was long-term exposure to low doses that drove the changes. The scientists added that reduced lifespan was particularly problematic because older fish often contribute disproportionately to reproduction, genetic diversity and population stability.

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A new study from Cornell and University of Toronto researchers has found that polyester microfibers shed from synthetic clothing during laundry can interfere with cherry tomato plant development [non-paywalled source] when these particles accumulate in agricultural soil. Plants grown in contaminated soil were 11% less likely to emerge, grew smaller and took several days longer to flower and ripen. Household laundry is a leading source of this contamination. Treated sewage sludge retains roughly 90% of microfibers from washers, and farmers in some countries apply this material to up to 75% of cropland as fertilizer. Some scientists have questioned the methodology. Willie Peijnenburg, a professor of environmental toxicology at Leiden University, told WaPo the microfiber concentration used was much higher than field observations. His research suggests plants primarily absorb microplastics through airborne particles entering leaf stomata rather than through soil.

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An anonymous reader quotes a report from the Guardian: High-profile studies reporting the presence of microplastics throughout the human body have been thrown into doubt by scientists who say the discoveries are probably the result of contamination and false positives. One chemist called the concerns "a bombshell." Studies claiming to have revealed micro and nanoplastics in the brain, testes, placentas, arteries and elsewhere were reported by media across the world, including the Guardian. There is no doubt that plastic pollution of the natural world is ubiquitous, and present in the food and drink we consume and the air we breathe. But the health damage potentially caused by microplastics and the chemicals they contain is unclear, and an explosion of research has taken off in this area in recent years. However, micro- and nanoplastic particles are tiny and at the limit of today's analytical techniques, especially in human tissue. There is no suggestion of malpractice, but researchers told the Guardian of their concern that the race to publish results, in some cases by groups with limited analytical expertise, has led to rushed results and routine scientific checks sometimes being overlooked. The Guardian has identified seven studies that have been challenged by researchers publishing criticism in the respective journals, while a recent analysis listed 18 studies that it said had not considered that some human tissue can produce measurements easily confused with the signal given by common plastics. There is an increasing international focus on the need to control plastic pollution but faulty evidence on the level of microplastics in humans could lead to misguided regulations and policies, which is dangerous, researchers say. It could also help lobbyists for the plastics industry to dismiss real concerns by claiming they are unfounded. While researchers say analytical techniques are improving rapidly, the doubts over recent high-profile studies also raise the questions of what is really known today and how concerned people should be about microplastics in their bodies.

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A major new review by the Cochrane collaboration -- an independent network of researchers -- evaluated 73 randomized controlled trials involving about 5,000 people with depression and found that exercise matched the effectiveness of both pharmacological treatments and psychological therapies. The biological mechanisms overlap considerably with antidepressants. "Exercise can help improve neurotransmitter function, like serotonin as well as dopamine and endorphins," said Dr. Stephen Mateka, medical director of psychiatry at Inspira Health. Dr. Nicholas Fabiano of the University of Ottawa added that exercise triggers the release of brain-derived neurotrophic factor, or BDNF, which he calls "Miracle-Gro for the brain." Exercise has been adopted as a first-line treatment in depression guidelines globally, though Fabiano noted it remains underutilized. The meta-analysis found that combining aerobic exercise and resistance training appeared more effective than aerobic exercise alone, and that 13 to 36 workouts led to improvements in depressive symptoms. Light to moderate exercise proved as beneficial as vigorous workouts, at least initially.

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An R&D lab under America's Energy Department annnounced this week that "Neuromorphic computers, inspired by the architecture of the human brain, are proving surprisingly adept at solving complex mathematical problems that underpin scientific and engineering challenges." Phys.org publishes the announcement from Sandia National Lab: In a paper published in Nature Machine Intelligence, Sandia National Laboratories computational neuroscientists Brad Theilman and Brad Aimone describe a novel algorithm that enables neuromorphic hardware to tackle partial differential equations, or PDEs — the mathematical foundation for modeling phenomena such as fluid dynamics, electromagnetic fields and structural mechanics. The findings show that neuromorphic computing can not only handle these equations, but do so with remarkable efficiency. The work could pave the way for the world's first neuromorphic supercomputer, potentially revolutionizing energy-efficient computing for national security applications and beyond... "We're just starting to have computational systems that can exhibit intelligent-like behavior. But they look nothing like the brain, and the amount of resources that they require is ridiculous, frankly," Theilman said.For decades, experts have believed that neuromorphic computers were best suited for tasks like recognizing patterns or accelerating artificial neural networks. These systems weren't expected to excel at solving rigorous mathematical problems like PDEs, which are typically tackled by traditional supercomputers. But for Aimone and Theilman, the results weren't surprising. The researchers believe the brain itself performs complex computations constantly, even if we don't consciously realize it. "Pick any sort of motor control task — like hitting a tennis ball or swinging a bat at a baseball," Aimone said. "These are very sophisticated computations. They are exascale-level problems that our brains are capable of doing very cheaply..." Their research also raises intriguing questions about the nature of intelligence and computation. The algorithm developed by Theilman and Aimone retains strong similarities to the structure and dynamics of cortical networks in the brain. "We based our circuit on a relatively well-known model in the computational neuroscience world," Theilman said. "We've shown the model has a natural but non-obvious link to PDEs, and that link hasn't been made until now — 12 years after the model was introduced." The researchers believe that neuromorphic computing could help bridge the gap between neuroscience and applied mathematics, offering new insights into how the brain processes information. "Diseases of the brain could be diseases of computation," Aimone said. "But we don't have a solid grasp on how the brain performs computations yet." If their hunch is correct, neuromorphic computing could offer clues to better understand and treat neurological conditions like Alzheimer's and Parkinson's.

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Scientists are putting Einstein's claim that the speed of light is constant to the test. While researchers found no evidence that light's speed changes with energy, this null result dramatically tightens the constraints on quantum-gravity theories that predict even the tiniest violations. ScienceDaily reports: Special relativity rests on the principle that the laws of physics remain the same for all observers, regardless of how they are moving relative to one another. This idea is known as Lorentz invariance. Over time, Lorentz invariance became a foundational assumption in modern physics, especially within quantum theory. [...] One prediction shared by several Lorentz-invariance-violating quantum gravity models is that the speed of light may depend slightly on a photon's energy. Any such effect would have to be tiny to match existing experimental limits. However, it could become detectable at the highest photon energies, specifically in very-high-energy gamma rays. A research team led by former UAB student Merce Guerrero and current IEEC PhD student at the UAB Anna Campoy-Ordaz set out to test this idea using astrophysical observations. The team also included Robertus Potting from the University of Algarve and Markus Gaug, a lecturer in the Department of Physics at the UAB who is also affiliated with the IEEC. Their approach relies on the vast distances light travels across the universe. If photons of different energies are emitted at the same time from a distant source, even minuscule differences in their speeds could build up into measurable delays by the time they reach Earth. Using a new statistical technique, the researchers combined existing measurements of very-high-energy gamma rays to examine several Lorentz-invariance-violating parameters favored by theorists within the Standard Model Extension (SME). The goal was ambitious. They hoped to find evidence that Einstein's assumptions might break down under extreme conditions. Once again, Einstein's predictions held firm. The study did not detect any violation of Lorentz invariance. Even so, the results are significant. The new analysis improves previous limits by an order of magnitude, sharply narrowing where new physics could be hiding.

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alternative_right shares a report from ScienceAlert: At the Experimental Advanced Superconducting Tokamak (EAST), physicists successfully exceeded what is known as the Greenwald limit, a practical density boundary beyond which plasmas tend to violently destabilize, often damaging reactor components. For a long time, the Greenwald limit was accepted as a given and incorporated into fusion reactor engineering. The new work shows that precise control over how the plasma is created and interacts with the reactor walls can push it beyond this limit into what physicists call a 'density-free' regime. [...] A team led by physicists Ping Zhu of Huazhong University of Science and Technology and Ning Yan of the Chinese Academy of Sciences designed an experiment to take this theory further, based on a simple premise: that the density limit is strongly influenced by the initial plasma-wall interactions as the reactor starts up. In their experiment, the researchers wanted to see if they could deliberately steer the outcome of this interaction. They carefully controlled the pressure of the fuel gas during tokamak startup and added a burst of heating called electron cyclotron resonance heating. These changes altered how the plasma interacts with the tokamak walls through a cooler plasma boundary, which dramatically reduced the degree to which wall impurities entered the plasma. Under this regime, the researchers were able to reach densities up to about 65 percent higher than the tokamak's Greenwald limit. This doesn't mean that magnetically confined plasmas can now operate with no density limits whatsoever. However, it does show that the Greenwald limit is not a fundamental barrier and that tweaking operational processes could lead to more effective fusion reactors. The findings have been published in Science Advances.

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