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Denisovans in southwestern China reveal their ancient subsistence strategies

9 September 2026 at 18:03

The Denisovans, the enigmatic archaic human relatives first identified from a finger bone and a handful of teeth in a Siberian cave, have long been known almost exclusively through their DNA. Now, a landmark study published in Nature has pulled back the curtain on how these ancient hominins actually lived — what they ate, how they hunted, what tools they made, and the environments they braved — through an extraordinary assemblage of fossils and artefacts from Bianfu Cave in Yunnan Province, southwestern China. The findings paint the most detailed portrait to date of Denisovan biology, behaviour and ecology in eastern Asia, and suggest that these vanished people left a deep genetic and cultural imprint on later populations across Southeast Asia and Oceania.

The research team, led by Qingfeng Ruan, Hua Li and Song Xing and their colleagues, conducted a comprehensive analysis of hominin fossils and the associated archaeological remains recovered from Bianfu Cave. The hominin fossils themselves date to roughly 167,000 to 134,000 years ago, placing them firmly in the Middle Pleistocene. But the cultural sequence preserved in the cave’s sediments is far longer, stretching from approximately 190,000 years ago to about 70,000 years ago. That span — some 120,000 years of continuous or near-continuous occupation — makes Bianfu Cave one of the longest cultural records that can most parsimoniously be attributed to Denisovans anywhere in the world.

The Denisovan identity of the fossils was established through two independent and technically demanding lines of evidence. The first involved analysis of the enamel–dentine junction, the internal boundary between the enamel cap and the underlying dentine of the teeth. This three-dimensional morphological interface acts something like a fingerprint of evolutionary relationships, revealing diagnostic traits of the tooth’s internal architecture that are invisible from the outside but characteristic of particular hominin lineages. The second line of evidence came from palaeoproteomics, the recovery and identification of ancient proteins preserved within fossilized tissues. Because proteins are far more abundant and durable than DNA, they can survive in warm, humid environments like those of southern China, where genetic material degrades rapidly. Sequencing these ancient proteins allowed the researchers to place the Bianfu hominins on the Denisovan branch of the human family tree with confidence.

The fossil collection itself is remarkable. It includes four teeth that substantially expand the known range of dental variation within the Denisovan lineage — a critical contribution, since Denisovans were previously represented by a very small number of dental specimens, making it difficult to gauge how variable their teeth could be. The new fossils also include two cranial fragments and a radius, a forearm bone, providing rare glimpses of Denisovan skull and postcranial anatomy that were previously almost entirely unknown. Together, these remains transform Denisovans from a genome and a scatter of isolated teeth into a population with recognizable skeletal biology.

Beyond the fossils, the archaeological record from Bianfu Cave offers something equally precious: a window into Denisovan daily life. The researchers reconstructed the ancient environment using faunal remains and pollen preserved in the cave deposits. These records indicate that across Marine Isotope Stages 6 through 4 — a period encompassing major glacial–interglacial climatic swings between roughly 190,000 and 57,000 years ago — the landscape around the cave was dominated by coniferous forest or a mosaic of forest and steppe. This was a cool, variable environment that Denisovans exploited successfully across tens of thousands of years, demonstrating a resilience to climatic change that adds to growing evidence of their adaptability, from the high altitudes of the Tibetan Plateau to the subtropical latitudes of mainland Southeast Asia.

The subsistence evidence is particularly striking. Analysis of the animal bones from the cave shows that its inhabitants practised specialized hunting focused on medium- to large-bodied prey. This was not opportunistic scavenging but a sustained, targeted hunting strategy — one that would have required knowledge of animal behaviour, coordinated effort and effective weaponry. Specialized big-game hunting of this kind has often been associated with modern humans and late Neanderthals in western Eurasia, so finding it in a Denisovan context more than 150,000 years ago dramatically narrows the perceived behavioural gap between these archaic lineages and our own species.

Yet the technological strategy documented at Bianfu Cave is, at first glance, surprisingly simple. The stone tool assemblage is characterized by expedient core reduction and tool production — that is, the inhabitants struck flakes from cores as needed, used them, and discarded them, rather than investing in carefully shaped, curated tools that were carried, maintained and resharpened over time. Alongside this, the Denisovans of Bianfu Cave made pervasive use of unmodified bones, employing skeletal elements of their prey directly as tools without altering them beforehand.

Taken together, the researchers interpret this pattern as an adaptive system that prioritized the exploitation of what they call object affordance — the inherent functional possibilities already present in a raw material or object — over intensive tool manufacture. A suitably shaped bone fragment could serve as a hammer, a digging implement or a scraping tool with little or no modification; a sharp flake struck from a convenient core could cut and butcher without further refinement. In the rich, resource-diverse environments of subtropical southwestern China, where raw materials and animal resources were plentiful, such a flexible, low-investment strategy may have been not a sign of simplicity but a highly efficient way of life. It suggests that Denisovans measured success not by the sophistication of their toolkit but by how skilfully they read and exploited the opportunities their landscape provided.

This behavioural portrait gains added significance when set against the wider geography of Denisovan presence. Over the past decade and a half, Denisovans have been documented across a staggering range: from the original genomic discoveries in the Altai Mountains of Siberia, first reported in 2010, to the mandible from the Tibetan Plateau described in 2019, Denisovan DNA recovered from sediments at Baishiya Karst Cave in 2020, a molar from the Annamite Chain of northern Laos announced in 2022, a male Denisovan mandible from Pleistocene Taiwan reported in 2025, and proteomic identification of the 146,000-year-old Harbin cranium, also in 2025. Bianfu Cave now anchors this story firmly in southwestern China, a region long suspected to have been a Denisovan heartland and a critical corridor for hominin movements between mainland Asia and Southeast Asia.

The study’s authors argue that the region’s Denisovans point to a substantial genetic and cultural legacy in later human populations. Modern populations in Southeast Asia and Oceania carry the highest known proportions of Denisovan ancestry anywhere in the world — a legacy of interbreeding that occurred as modern humans moved through and beyond island Southeast Asia. The new evidence from Bianfu Cave suggests that the ways of life practised by Denisovans in this region — their hunting strategies, their flexible technological approaches, their hard-won knowledge of tropical and subtropical environments — may have been part of the inheritance, alongside their genes, that helped later human populations thrive as they spread across the diverse and challenging landscapes of Asia and the Pacific.

For palaeoanthropologists, the significance of the Bianfu Cave discoveries is difficult to overstate. Denisovans have been the least anatomically documented of all known hominin groups — a lineage defined first by DNA and only slowly fleshed out with fragmentary fossils. The new teeth, cranial fragments and radius from Yunnan, combined with an unmatched 120,000-year archaeological sequence, mean that researchers can finally study Denisovans not just as a genome or a set of molecular signatures but as a living, adapting population: hunters of large game, makers and users of expedient tools, and inhabitants of conifer forests that swung between glacial cold and interglacial warmth. As analysis of the Bianfu material continues, it promises to reshape our understanding of how archaic humans lived in eastern Asia and how deeply their story is woven into our own.

Subject of Research: Denisovan fossils and archaeological remains from Bianfu Cave, Yunnan Province, southwestern China, revealing Denisovan biology, technology, subsistence strategies and palaeoecology

Article Title: Denisovans from southwestern China and their subsistence strategies

Article References: Ruan, Q., Li, H., Xing, S., Zhao, K., Liu, J., Zanolli, C., Doyon, L., Delpiano, D., Peresani, M., d’Errico, F., Demeter, F., Hublin, J.-J., Xiao, P., Wang, Y., Jia, Z., Yang, Q., Fu, Q., Sun, Q., Zhao, Y., … Chen, F. (2026). Denisovans from southwestern China and their subsistence strategies. Nature. https://doi.org/10.1038/s41586-026-10997-4

Image Credits: AI Generated

DOI: 10.1038/s41586-026-10997-4

Keywords: Denisovans, Bianfu Cave, Yunnan, palaeoproteomics, enamel–dentine junction, Middle Pleistocene, subsistence strategies, expedient tool use, object affordance, specialized hunting, Marine Isotope Stages, Southeast Asia ancestry

Locking-enabled multimodal soliton microcombs achieve day-scale stability for precision metrology

9 September 2026 at 17:57

Optical frequency combs have transformed the way scientists measure light and time, earning the Nobel Prize in Physics in 2005 and underpinning technologies ranging from atomic clocks to exoplanet detection. Yet the miniature on-chip versions of these combs, known as soliton microcombs, have long suffered from a frustrating paradox: the most stable and useful operating regimes have also been the most fragile and difficult to sustain. A newly published study in Light: Science & Applications reports a significant advance toward resolving this tension. Researchers led by J. Tang, J. Yang and E. Yan describe a multimodal locking-enabled soliton microcomb that combines robust, self-starting operation with an exceptionally low repetition rate on the scale of a day of stable measurement time, opening a path toward practical high-precision metrology systems that can run unattended for extended periods.

At the heart of the advance is a technique the authors call multimodal locking, a scheme that stabilizes not just a single resonance of the optical microresonator but multiple modes simultaneously, locking the comb dynamics to a regime in which dissipative Kerr solitons can form and persist without delicate manual tuning. In conventional microcomb systems, soliton formation typically requires a precise and rapid traversal of a “chaotic” modulation instability regime, a step that is notoriously sensitive to thermal transients in the resonator chip. Laser frequency must be swept with exquisite control while the soliton’s own heat dissipation shifts the resonator’s resonances, creating a feedback loop that can destroy the soliton state within microseconds. The multimodal locking approach circumvents this fragility by engaging several mode families of the resonator at once, so that the interplay among them pins the comb to a stable soliton state even as environmental and thermal conditions fluctuate.

The significance of achieving a low repetition rate in the same device cannot be overstated. A frequency comb’s repetition rate is the spacing between its individual comb teeth, and for many applications, coarser spacing is a decisive advantage. In laser ranging and distance metrology, for example, the ambiguity range of an interferometric measurement is set by the inverse of the comb’s free spectral range. Microcombs, generated in whispering-gallery-mode or ring resonators only a few millimeters across, usually exhibit repetition rates of tens to hundreds of gigahertz, which severely limits the unambiguous measurement range available to a comb-tooth-resolved distance measurement. By engineering a low-repetition-rate soliton state, the research team extends this ambiguity range dramatically, making the microcomb directly useful for absolute distance measurement, multi-wavelength interferometry and coherent communications, where each comb line must be spectrally resolvable and addressable.

Achieving both low repetition rate and robust soliton generation in a single microresonator is a formidable engineering challenge. Low repetition rates demand large resonator diameters, which in turn produce dense spectra of resonances and increased susceptibility to mode crossings with higher-order transverse and polarization mode families. Such crossings historically destabilize soliton formation, causing comb states to collapse or preventing single-soliton operation altogether. The multimodal locking strategy turns this liability into an asset: rather than engineering mode crossings away, the researchers harness the coupling among mode families to lock the comb dynamics into a favorable basin of attraction. The result is a soliton microcomb whose low repetition rate is preserved over day-scale timeframes, a duration that places the device among the most operationally stable microcomb demonstrations reported to date.

Day-scale stability matters because it transforms the microcomb from a laboratory demonstration into an instrument. Many high-precision experiments, from astronomical spectrograph calibration to the accumulation of statistical confidence in atomic spectroscopy, require comb sources that remain locked and stable across many hours or even days of continuous operation. Conventional fiber-laser-based frequency combs achieve this, but at the cost of table-top size, high power consumption and substantial maintenance overhead. Microcombs promised to shrink the technology onto a photonic chip, yet until now their operational fragility has confined most demonstrations to short observation windows. The robust low-repetition-rate soliton microcomb described in the new work demonstrates that chip-scale frequency combs can, with appropriate locking architecture, sustain the kind of long-duration, hands-off operation that real metrology campaigns demand.

The physics underlying soliton microcombs rests on the Kerr nonlinearity of the resonator material, typically silicon nitride, magnesium fluoride or fused silica. When continuous-wave pump light resonantly builds up inside the ring, the Kerr effect produces a four-wave-mixing process that seeds sidebands spaced by the resonator’s free spectral range. Under the right conditions of pump detuning and intracavity power, these sidebands evolve into a coherent train of ultrashort optical pulses, dissipative Kerr solitons, that circulate around the resonator and emit a broadband comb spectrum with tooth spacing equal to the repetition rate. The comb’s output frequencies are determined by two radio-frequency quantities, the pump laser frequency and the repetition rate, which is why the combs can serve as rulers for measuring optical frequencies against a reference. Any drift in either quantity propagates directly into measurement error, and the multimodal locking mechanism suppresses precisely this drift by anchoring the comb’s underlying mode structure to the resonator’s intrinsic stability.

Applications for such a device span an unusually broad swath of science and engineering. In high-precision laser ranging, low-repetition-rate combs with tooth spacings in the low-gigahertz or even megahertz regime allow interferometric distance measurements over ranges of meters to kilometers without the need for auxiliary synthetic-wavelength techniques. In astronomical spectroscopy, comb calibration sources with well-controlled line spacing enable the detection of Earth-like exoplanets through radial velocity shifts measured in centimeters per second. In telecommunications, low-repetition-rate combs align naturally with standard channel grids used in wavelength-division multiplexed fiber networks, making them attractive as multi-carrier sources. In spectroscopy, dual-comb techniques benefit from repetition rates that are low enough to permit resolution of closely spaced molecular absorption features. A microcomb that is simultaneously robust, low-repetition-rate and day-scale stable therefore functions as a versatile enabling component across these domains rather than a single-purpose device.

The demonstration also speaks to a broader trend in photonics: the migration from delicate, expert-operated laboratory setups to self-contained, self-stabilizing systems. The self-starting character implied by multimodal locking is particularly important for this transition. A comb that requires a skilled operator to initiate soliton formation, sweeping the laser with practiced timing past the chaotic regime, cannot be deployed in an observatory dome, on a satellite platform or inside an industrial instrument. A comb that engages its soliton state reliably on demand and then holds it through thermal cycling, laser drift and mechanical perturbation removes the last practical barrier to integration. The authors’ demonstration of day-scale continuous operation is, in effect, a stress test passed by a technology that researchers have been attempting to harden for more than a decade.

The implications extend to metrology standards and timing as well. Optical atomic clocks, which now achieve fractional frequency uncertainties below one part in 10^18, rely on frequency combs to divide down their optical oscillations to countable microwave rates. Miniaturizing the comb stage of such clocks is a prerequisite for portable optical timekeeping, which would benefit navigation in GPS-denied environments, geodesy that monitors sea level and crustal motion with millimeter precision, and fundamental physics tests that track the constancy of natural constants over months and years. A robust chip-scale soliton microcomb with day-scale stability contributes a key subsystem to this vision, and the multimodal locking principle may generalize to other resonator platforms, materials and spectral regions, including the mid-infrared where molecular fingerprinting awaits compact comb sources.

Looking forward, the study suggests several directions that the photonics community is likely to pursue. Combining multimodal locking with on-chip pump lasers and integrated electronics would complete the transformation toward fully self-contained comb modules with no free-space optics. Extending the approach to lower repetition rates still, into the megahertz regime where fiber-laser combs operate, would bring microcombs into direct competition with their bulkier predecessors for the most demanding ranging and spectroscopy tasks. Improvements in resonator fabrication, reducing mode-volume disorder and engineering dispersion with greater precision, will further expand the parameter space in which robust soliton states can be locked. The present work demonstrates that the fragility once considered intrinsic to soliton microcombs is not a fundamental limit but an engineering problem, and one that can be solved by embracing, rather than avoiding, the multimodal structure of real optical resonators.

The research, published in Light: Science & Applications, marks a milestone in the maturation of microcomb technology. By uniting three properties that had previously been achieved only separately, self-starting robustness, low repetition rate and day-scale operational stability, the work delivers a soliton microcomb genuinely suited to high-precision metrology. As the demand for compact frequency references accelerates across navigation, astronomy, communications and fundamental science, the multimodal locking strategy reported by Tang, Yang, Yan and colleagues offers a clear and technically grounded route from chip-scale optical chaos to dependable, precision measurement light.

Subject of Research: A robust, self-starting low-repetition-rate soliton microcomb enabled by multimodal locking for day-scale-stable, high-precision metrology applications.

Article Title: Multimodal locking-enabled robust and day-scale low-repetition-rate soliton microcomb for high-precision metrology

Article References: Tang, J., Yang, J., Yan, E., Huang, G., Yin, K., Tian, D., Lei, X., Huang, J., Yang, M., Ding, H., Yan, S., Wei, K., Zhu, L., Wang, G., & Jiang, T. (2026). Multimodal locking-enabled robust and day-scale low-repetition-rate soliton microcomb for high-precision metrology. Light: Science & Applications, 15(1), Article 370. https://doi.org/10.1038/s41377-026-02460-w

Image Credits: AI Generated

DOI: 10.1038/s41377-026-02460-w

Keywords: soliton microcomb, multimodal locking, low repetition rate, frequency comb, high-precision metrology, laser ranging, day-scale stability, dissipative Kerr solitons, chip-scale photonics, optical frequency reference, self-starting comb, Light Science & Applications

Anthropic researchers say AI could cause human extinction by 2030

9 September 2026 at 16:53

One researcher who resigned said many in industry believe that without regulation AI could kill off humanity

Artificial intelligence could kill off humanity within the decade, according to three researchers with the industry giant Anthropic, one of whom has quit his job in protest.

The latest doom-laden predictions came in posts on social media on Tuesday by a researcher who said he resigned because Anthropic and his previous employer, OpenAI, were ignoring or at best mishandling their response to the threat.

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© Photograph: Samyukta Lakshmi/Bloomberg via Getty Images

© Photograph: Samyukta Lakshmi/Bloomberg via Getty Images

© Photograph: Samyukta Lakshmi/Bloomberg via Getty Images

Classic sitcom ‘Friends’ helps grad student endure 104 brain scans

9 September 2026 at 15:08

The science of getting Z’s has progressed rapidly in recent years. A growing body of research links poor sleep to increased risk of cognitive decline, a higher likelihood of Alzheimer’s disease, and even greater chances of developing heart problems. At the same time, wearables, like smart rings and watches, are transforming the way everyday people view sleep, turning their resting hours into rich datasets to pore over, sometimes to unhealthy obsessive levels. 

What’s still less understood, is how the subtle, everyday fluctuations in sleep quality that come from simply living a normal life can alter brain chemistry. People don’t live in controlled lab settings, and even the most avid bio-optimizer still has nights where quality sleep takes a backseat. Actually understanding how someone’s day-to-day sleep patterns affect their brain chemistry would require putting them in an MRI machine and collecting data over and over again, over long stretches of time to get a more holistic view. 

That’s exactly what Auburn University electrical and computer engineering graduate student Joshita Majumdar signed up for. Over 76 weeks, Majumdar slipped into the university’s 7-Tesla MRI scanner 104 times. That’s a level of commitment that would make even a stalwart Zen meditator fidget with frustrated boredom. Thankfully, Majumdar had a special companion to accompany her during the loud, cramped, 90-minute sessions: the hit television sitcom Friends.

a woman wearing blue scrubs sits outside of an MRI machiene
Over 76 weeks, Joshita Majumdar went into Auburn University’s  7-Tesla MRI scanner 104 times. Image: Joshita Majumdar/Auburn University.

Majumdar recalls how a screen in the machine would cycle through four 10-minute videos of the staple from the 90’s and early 2000’s, each made up of several different scenes clipped together. The idea was twofold. Majumdar needed something playing during the sessions that would keep her from getting bored, and Friends just happens to be her self-described “guilty pleasure.” It was also one of the first shows she connected with as an international student adjusting to her early days in the United States, so some scenes strike particularly nostalgic, emotional notes. And like any great sitcom, Friends runs the gamut from numbing brain-rot to tear-jerking sentimentality. That’s potentially a great backdrop for a study analyzing changes in brain chemistry.  

“If you’re happy, you watch Friends. If you’re sad, you watch Friends,” Majumdar tells Popular Science. “So all times [are] a good time to watch Friends, right?”

Past studies have looked at the way sleep variability affects brain chemistry, but many of those involve intentionally depriving the subject of sleep. This longer-term approach takes a more subtle approach that should better reflect the nuances of everyday life. 

“This is a person living her life, going through normal ups and downs and we are seeing how brain chemistry responds to that,” Majumdar’s advisor and Auburn University Electrical and Computer Engineering Professor Gopikrishna Deshpande said.  “That’s what makes this dataset so powerful. It’s not artificial. It’s not forced. It’s real.”

The journey to 104 brain scans 

Majumdar grew up in Kolkata, West Bengal, India, and moved to the U.S. in 2016 to pursue a master’s degree in engineering at the University of Georgia, with an emphasis on mechanical engineering. Early on, she became interested in how different environmental factors affect brain function. And while she was busy pushing forward with her rigorous academic work, she also dealt with occasional homesickness, living in a new country thousands of miles away from friends and relatives. 

Around that same time, Majumdar says she started watching Friends to see what all the fuss was about. People around her seemed obsessed with the show, but she hadn’t seen it, and initially didn’t really understand the hype. Eventually, she went back to the show with fresh eyes and everything clicked. The sarcastic Chandler Bing (Matthew Perry) and affable actor Joey Tribbiani (Matt LeBlanc) are among her favorite characters.

“I gave it another try, and then I was like, oh no, this is fun,” Majumdar said. “And then it became a guilty pleasure.” 

When it came time to pick a test subject for this new, lengthy MRI study, Majumdar says Dr. Deshpande asked her if she’d be up for volunteering. Majumdar has some experience with MRI machines from past projects, enough to know that she wasn’t prohibitively claustrophobic or bothered by the machine’s loud industrial noises. Still, nothing she’d done before this could compare to the endurance and commitment it would take to see this through. The team decided not to commit to a set number of scans at the onset, and took it day by day to see how much the grad student could handle. 

“We said, like, ‘Okay, we’ll take one day at a time, one week at a time, and see how far we can pull it through,” Majumdar explained. 

Don’t sleep on Friends  

Majumdar was the one who pitched playing Friends episodes in the machine. She compiled four 10-minute videos, each made up of different scenes from various episodes. The material ran the gamut in tone, with the goal of eliciting a range of brain responses. One particularly strategic choice was to include clips of episodes aired around Thanksgiving. These fan-favorites tend lean heavily on themes of family, friendship, and camaraderie. Friends, in other words, was meant to roughly simulate the backdrop for Majumdar’s everyday life brain state. 

“In a task-based MRI, we are giving a particular stimulus, so we kind of have an idea what we are trying to activate in the brain,”  Majumdar said. “But in a naturalistic run, it’’s kind of like you’re putting yourself into a real-world situation.” 

a still image from an episode of the show friends. a woman with blonde hair stands next to a bench while a woman with a black hat and green shirt, woman with a blue new york giants sweatshirt, man with a red jersey, man with a blue sweatshirt, and man with a black sweatshirt and blue hat on backwards sit on a bench above fall leaves
“The One with the Football” (Season 3, Episode 9) is one of 10 Thanksgiving episodes of Friends. Pictured (left to right) Lisa Kudrow as Phoebe Buffay, Jennifer Aniston as Rachel Green, Courteney Cox Arquette as Monica Geller, Matt LeBlanc as Joey Tribbiani, David Schwimmer as Ross Geller, and Matthew Perry as Chandler Bing. The show ran from 1994 to 2004. Image: Gary Null/NBCU Photo Bank.

But that wasn’t all. Every session, the team would also play a roughly four-minute music video to the song “Love You Zindagi,” from the 2016 Bollywood film Dear Zindagi. Similar to the Thanksgiving episodes, this video was thoughtfully selected for its depiction of friends and family. It also helps remind Majumdar of home. 

“I have left my friends and family back in India,” Majumdar said. “So depending upon what my emotions are on that day, I used to really connect to it differently each day.”

Majumdar and her colleagues quickly settled into a routine for their MRI odyssey. She would come to the university’s neuroimaging center on Tuesdays and Thursdays, typically around 7:30 in the evening. She had the choice of that later time slot or first thing in the morning, but chose the former because she says she isn’t really a morning person. That choice came with some trade-offs, though. 

Early on, she discovered that eating a meal immediately before entering the machine made her feel dizzy. After one fraught experience, she made a point of giving herself a gap of 90 minutes to two hours after eating before going into the scanner. Coming in later at night, especially after a long day of PhD work, also meant she sometimes had to fight the urge to fall asleep. Even though she was stuck in the machine for 90 minutes at a time, the tests required that she keep her eyes open for the vast majority of it. That struggle is partly what makes subsequent findings all the more interesting. 

“Sometimes I was a little bit sleepy, but that’s part of it,” Majumdar said. “And that’s the thing that we wanted to bring out through this research: that you are in a very natural setting. You’re not in a kind of a forced experiment where you are either sleep-deprived or put under some conditions that might evoke a different brain response. We really wanted to look at the real-world condition where I’m just living my life, and in parallel I’m getting scanned and seeing how the brain chemistry responds to it.”

In addition to sitting in the MRI machine, Majumdar logged everything she ate and wore a sleep-tracking ring. With all of that data, the team was able to match each night’s sleep metrics with the next day’s scan and compare patterns over time. Though there’s still data being combed through, they’ve already found an important connection: across the 104 sessions collected over 76 weeks, nights with less deep sleep and more light sleep tended to be followed by higher glutamate levels the next day. Glutamate is an amino acid that acts as a kind of chemical messenger in the brain. In a previous university blog post, Majumdar compared this finding to the brain flushing out byproducts that build up during active, wakeful moments, allowing for a more restful night’s sleep.

“You wake up with a fresh mind,” she said. “But if that process is blocked, it’s going to hamper you the next day.”

Joshita Majumdar (right) a graduate student in the Department of Electrical and Computer Engineering, and Gopikrishna Deshpande (left), the Godbold Professor in the Department of Electrical and Computer Engineering, used equipment at the Auburn University Neuroimaging Center, including the 7-Tesla MRI scanner, to study glutamate levels in the brain. Image: Auburn University.
Joshita Majumdar (right) a graduate student in the Department of Electrical and Computer Engineering, and Gopikrishna Deshpande (left), the Godbold Professor in the Department of Electrical and Computer Engineering, used equipment at the Auburn University Neuroimaging Center, including the 7-Tesla MRI scanner, to study glutamate levels in the brain. Image: Auburn University.

But is she sick of sipping coffee at Central Perk?

Majumdar’s work in this area has only just begun. Moving forward, she and her colleagues hope to bring on more study participants  to make the dataset even richer, though they’ll likely make adjustments so that each participant doesn’t have to go in for scans quite as often as she did. 

Eventually, she says she also hopes to use AI and other tools to try and extract the feelings and emotions experienced during those MRI sessions (and during certain Friends’ moments) to get a better sense of what’s happening in the brain when certain feelings are evoked. 

Miraculously, even after watching the show in a cramped, rumbling tube for 18 months, Majumdar says she still isn’t sick of Friends. When asked if she can still watch the silly sitcom without getting bored, Majumdar responds with an emphatic, 

“Yes, definitely.”

The post Classic sitcom ‘Friends’ helps grad student endure 104 brain scans appeared first on Popular Science.

MacVoices #26252: Live! – Tim Cook, John Ternus, and Apple’s Changing of the Guard

By: Chuck
9 September 2026 at 15:04
The MacVoices Live!  examines Apple’s transition from Tim Cook to John Ternus, weighing Cook’s legacy, Apple’s dramatic financial growth, Vision Pro, and criticism of his tenure. They consider what Ternus’ engineering background could mean for hardware and software, while discussing Phil Schiller, Eddie Cue, other executive changes, succession planning, and the importance of preserving institutional […]

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AI could kill all humans in next decade, warn experts: but how seriously should we take them?

Alarming warnings from industry insiders increase pressure for curbs on artificial superintelligence

Does artificial superintelligence really pose a risk greater than nuclear weapons? Is there a significant chance of “a Chornobyl-sized catastrophe”. Might there even be a greater than 10% chance that AI could “kill all humans” in the next decade?

These warnings were issued over the past 48 hours on both sides of the Atlantic about the potential impact of a technology that most people still think of as a more talkative search engine.

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© Illustration: Ales Utouka/Alamy

© Illustration: Ales Utouka/Alamy

© Illustration: Ales Utouka/Alamy

Hurricane Lowell Floods Western Hawaii, New Forest Wildfire Threatens Woodland — Today’s Environmental Briefing for Wed, Sep 9 2026

9 September 2026 at 14:00
Flooded roadway with uprooted trees in western Hawaii after Hurricane Lowell

Across the stories today, a common thread emerges: the gap between what protects us on paper and what protects us in practice. Again and again, communities are discovering that designations, promises, and permits only matter when someone is willing to enforce them — and that when systems fail, it’s ordinary people, and often the most vulnerable, who absorb the shock.

Nowhere is that clearer than in Jackson, Mississippi, where a federal appeals court ruled this week that the Constitution guarantees no right to clean water. For residents who have lived through years of contaminated taps and boil-water notices, the decision lands as a gut-punch reminder that legal frameworks haven’t caught up to environmental reality. A similar tension runs through the Guardian’s reporting on datacenter wastewater in Wyoming, where testing turned up a rare, potentially hazardous bacterium, and on English golf clubs, where one in twelve have quietly broken water extraction rules amid growing drought stress. Behind the numbers are real communities adapting in real time — often without knowing what’s actually flowing through their pipes or being pulled from their aquifers.

That same gap between promise and delivery surfaces in the UK’s datacentre boom, which new analysis suggests will produce only a quarter of the jobs once advertised, even as it strains the national grid. It echoes in Georgia, where a once-booming EV manufacturing corridor is hitting turbulence under shifting federal policy — a reminder that industrial transitions built on incentives can be as fragile as the politics that fund them.

Yet the day’s coverage also points to growing momentum around care, restoration, and reckoning. Hurricane Lowell’s damage across Hawaii’s western islands — toppled trees, flooded roads, thousands without power — sits alongside quieter stories of renewal: Gloucestershire’s proposal to reintroduce beavers as a defense against drought and flooding, Douglas Head’s new conservation status on the Isle of Man, and Coventry’s investment in Longford Nature Park. These are small, deliberate acts of stewardship, the kind Wendell Berry spent his life advocating for. His death last week, at 92, feels newly resonant this week — a farmer-poet who insisted that loving a place well was itself a form of environmental action, long before it became policy language.

Farther afield, the human cost of extraction runs deep. In Peru and Brazil, mercury from illegal gold mining is showing up in children’s blood and in fish that families have eaten for generations, forcing painful dietary changes in communities that did little to cause the contamination. In Indonesia, El Niño-fueled fires are pushing orangutans out of burning forests, while in Uttarakhand, India, women — who gather firewood and fodder — are bearing the brunt of increasingly long fire seasons. In Colombia, the Wiwa community’s decision to relocate their village down the mountain is less retreat than adaptation, a recognition that sacred land is changing faster than tradition can hold still.

It’s a reminder that progress and pressure often arrive together — a new spaceport investment in Shetland, a badger vaccination program under scientific scrutiny, a push for a Natural History GCSE to reconnect children with the outdoors. Each represents a small bet on the future, even as larger systems strain under climate and economic pressure.

As the week unfolds, watch whether the Jackson ruling prompts congressional attention, whether Britain’s Green Party succeeds in forcing transparency around ecosystem collapse risks, and whether Gloucestershire’s beavers get their chance to prove that sometimes the oldest solutions are still the best ones.

The post Hurricane Lowell Floods Western Hawaii, New Forest Wildfire Threatens Woodland — Today’s Environmental Briefing for Wed, Sep 9 2026 first appeared on EnviroLink Network.

A New Cold War Is Unfolding in Orbit as China Advances Satellite Surveillance

9 September 2026 at 12:55

Chinese scientists at the Beijing Institute of Technology have run satellite proximity simulations to extend potentially hostile observation of U.S. space assets in Geostationary Earth Orbit (GEO), seemingly inching both countries closer to a potential war in space.

Although the new simulations focus on orbital adjustments to extend observation times and increase proximity to U.S. satellites, including critical missile warning and other space defense-oriented systems, Chinese scientists also plan to integrate reinforcement learning methods into future space assets to give satellites even more independence from human operators.

Study Includes Accusations of Cold War in Space Activities

In the 20th century, the concept of war in space remained mostly in the realm of science fiction, as depicted in popular films like Star Wars. Today, advances in space access, orbital maneuvering technologies, and weapons systems have made the possibility of a future conflict in space a very real security concern, and several nations engage in espionage using reconnaissance spacecraft to obtain information on valuable defense targets in Earth’s orbit.

According to the authors of the new study, “acquiring multi-aspect payload information of non-cooperative targets to infer their functions and mission statuses is of great significance for space security assessment.”

The study authors highlight a series of relative motion configurations that modern spy satellites employ, including fly-around, hovering, and drifting flight. They also point to real-world “adversarial” U.S missions they suggest were designed to gather intelligence on their GEO defense assets.

“Since 2014, the US GSSAP (United States Geosynchronous Space Situational Awareness Program) satellite has carried out hundreds of maneuvers and has conducted close observation operations on dozens of normally working satellites near GEO orbit,” the Beijing University of Technology scientists write.

The study authors also include a specific July 2021 accusation, where they charge that “the U.S. satellite ‘USA-271’ deliberately approached the operational ‘Practice 20’ satellite in geostationary orbit and flew in close proximity.”

In an email to The Debrief, a U.S. Space Command Spokesperson did not address the specific incident or the accusations of “dozens” of similar operations, but offered some insight into the agency’s thinking.

“USSPACECOM, working with allies and partners, plans, executes, and integrates military spacepower into multi-domain global operations in order to deter aggression, defend national interests, and when necessary, defeat threats,” the spokesperson told The Debrief, adding that “we have nothing additional to add in response to the article.”

Getting Closer to Adversarial Satellites and Extending Observation Time

In a step toward potential dogfights between satellites, the Chinese scientists looked at several challenges faced by current spy satellites.

For example, they explain, since most spacecraft observation cameras are mounted in a fixed position, “frequent large-angle attitude maneuvers are time-consuming and consume substantial fuel.” The researcher also noted that several different angles and approaches could yield different categories of intelligence data.

However, changing angles and orbital planes requires fuel, an extremely limited resource in GEO. Therefore, the researcher accounting for all the variables required to gather intelligence on adversarial spacecraft as efficiently as possible “has become a key bottleneck in enhancing space situational awareness capabilities.”

To find an optimized solution, the team designed what they called a “waypoint trajectory planning scheme” and a “multi-impulse maneuver strategy” using a common game-theory tool called “minimum integral squared control” theory. Unlike previous research aimed at extending spy satellite observation time and fuel efficiency, the Chinese scientists said their use of sequential coalition game theory “is introduced for the first time into the multi-model combined observation problem.”

Next, the researchers designed a “game tree.” A press release said this approach lets the spacecraft select the “optimal combination of initial motion points and close-range operation models at each stage under minimum fuel constraints, thereby generating an optimal observation strategy sequence.”

Finally, the researchers ran simulations to see whether their approach improved sensor observation times and field of view while reducing fuel use.

Successful Simulations and Future Reinforcement Learning Plans

As hoped, the Beijing University of Technology team said their simulations supported the theories. Specifically, the study authors said the simulations showed that their spacecraft efficiency algorithm “can successfully generate a multi-model combined observation strategy sequence under minimum fuel constraints.”

“The effective observation time increases with larger observation distances and field-of-view angles, and reducing the model configuration size also contributes to improved observation performance,” they explained. The study authors also said that the simulation results “demonstrate that the algorithm can successfully generate the optimal combined observation sequence under minimum fuel constraints.”

When discussing next steps, the Chinese scientists said they will explore optimal initial points to further improve maneuver efficiency. They also plan to explore a “reinforcement learning method,” suggesting future spacecraft could learn and adapt to evolving conditions to further enhance their cold war in space information-gathering capabilities.

Study’s War in Space Implications “Extends Beyond any Single Algorithm”

To understand the potential implications of the Chinese study, including its impacts on a potential future war in space, The Debrief reached out to former U.S. Air Force officer Shelli Brunswick, CEO and Founder, SB Global LLC.

According to the author and futurist, the Chinese team’s research matters not just because it proves China has deployed a “new operational surveillance capability.” Instead, Brunswick said that the work is significant because it “illustrates how sophisticated coordination and optimization could make spacecraft observation more efficient, persistent, and strategically useful.”

The Blue Marble Space Visiting Scholar also told The Debrief that the work “should not be interpreted as demonstrating a complete pursuit-and-evasion capability against a spacecraft that is actively responding,” since the work assumes a stationary target without maneuvering capabilities. Still, Brunswick noted, the Chinese framework “shows how game-theoretic planning could help an observing satellite gather information from multiple angles while managing limited resources.”

When discussing the potential implications for the broader U.S.-China space-security competition, including how such enhanced spacecraft could lead to more activities that could be construed as hostile, the space strategist said this area of research “extends beyond any single algorithm.”

“As rendezvous and proximity operations become more sophisticated, the line between inspection, space situational awareness, intelligence gathering, and potentially threatening behavior becomes increasingly difficult to interpret,” she explained.

When suggesting what potential strategic responses the U.S. and its allies might employ in the emerging cold war in space, Brunswick told The Debrief that they should include “more resilient architectures, improved space-domain awareness, clearer expectations for close approaches, stronger communication mechanisms, and deeper coordination with commercial and international partners.”

“The challenge is not simply detecting another spacecraft—it is understanding capability and intent early enough to respond responsibly and effectively,” Brunswick explained.

The study “Spacecraft Proximity Operation Model-Based Sequential Coalitional Observation Game Strategy Design” was published in Space: Science & Technology. 

Christopher Plain has spent the last six years as Associate News Editor and Head Science Reporter at The Debrief. Follow and connect with him on X, learn about his novels at plainfiction.com, or email him at christopher@thedebrief.org.

US allies lack resources to keep pace on AI, top Pentagon official says

Cameron Stanley talks up ‘revolutionary’ AI capabilities and says Washington working with Nato and Five Eyes partners

The Pentagon’s top artificial intelligence official said on Tuesday that America’s closest allies lack the resources to keep pace with the US military’s adoption of AI, and that Washington is working to steer them away from mistakes it made along the way.

“They don’t have the resources that we do, they don’t have the experience that we do, they don’t have the scale that we do,” Cameron Stanley, chief digital and artificial intelligence officer at the Department of Defense, said at an event at the Billington Cybersecurity summit. Of Nato and the Five Eyes, an intelligence-sharing partnership of the US, UK, Canada, Australia and New Zealand, Stanley said Washington was “actively working with a number of our partners” so “they don’t make the same mistakes that we make”.

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© Photograph: Alexander Drago/Reuters

© Photograph: Alexander Drago/Reuters

© Photograph: Alexander Drago/Reuters

Trump administration to confront Australia over Labor’s social media algorithm plan

9 September 2026 at 07:51

White House warns trading partners against ‘imposing digital services taxes, fines, and other forms of extortion’ on US tech sector

The Trump administration will confront Australia over its plan to force digital platforms to take down harmful content and let users opt out of algorithm-generated “for you” feeds.

Big tech companies would be fined more than $100m for breaching the proposed laws and the Australian government is under pressure to raise those fines even further.

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© Photograph: Annabelle Gordon/EPA

© Photograph: Annabelle Gordon/EPA

© Photograph: Annabelle Gordon/EPA

Apple unveils folding iPhone Duo as new CEO takes center stage

9 September 2026 at 19:45

The passport-size iPhone Duo serves as the first big test for John Ternus, who took over from Tim Cook last week

Apple has unveiled the iPhone Duo, the company’s first foldable phone and the most significant change to the iPhone since the smartphone’s introduction in 2007.

The nearly $2,000 device takes inspiration from iPads’ wide screens and combines them with the portability and camera features of iPhones. When opened, it is the company’s largest phone display and thinnest phone. The Duo opens and closes like a passport to double its screen size.

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© Photograph: Jeff Chiu/AP

© Photograph: Jeff Chiu/AP

© Photograph: Jeff Chiu/AP

UK datacentres will create just 25% of jobs predicted by tech sector, analysis finds

Facilities likely to employ 10,400 workers, compared with 40,000 in industry estimates, thinktank says

Datacentres in the UK will create just a quarter of the jobs predicted by the tech sector, while consuming vast amounts of energy, according to new research.

Environmental thinktank Verdant predicts that all the datacentres currently planned are likely to directly employ 10,400 workers – compared with the more than 40,000 cited in projections by the industry lobby group TechUK.

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© Photograph: Bloomberg/Getty Images

© Photograph: Bloomberg/Getty Images

© Photograph: Bloomberg/Getty Images

UK datacentres will create just 25% of jobs predicted by tech sector, analysis finds

Facilities likely to employ 10,400 workers, compared with 40,000 in industry estimates, thinktank says

Datacentres in the UK will create just a quarter of the jobs predicted by the tech sector, while consuming vast amounts of energy, according to new research.

Environmental thinktank Verdant predicts that all the datacentres currently planned are likely to directly employ 10,400 workers – compared with the more than 40,000 cited in projections by the industry lobby group TechUK.

Continue reading...

© Photograph: Bloomberg/Getty Images

© Photograph: Bloomberg/Getty Images

© Photograph: Bloomberg/Getty Images

MIT Engineers Create a Living Circuit Board From Bacteria

MIT Living TransistorsMIT researchers have engineered bacteria to behave like transistors, making it possible to build living “circuit boards” that can be printed onto growth material in a Petri dish. In conventional electronics, transistors act as switches that control whether electrical current flows. In the biological system developed at MIT, engineered bacteria perform a similar role by [...]

Google scientists removed a critical 'consciousness safeguard' from AI in new study. What happened next?

8 September 2026 at 23:23

Removing safety guardrails that stop artificial intelligence (AI) from claiming that it's conscious also makes it more prone to express belief in vampires, karma and ghosts, a new study finds. But experts warn a lack of mindedness could also have worrying consequences.

In research uploaded July 30 to the preprint arXiv database (which has not yet been peer-reviewed), scientists investigated the impact of "consciousness steering" — an AI fine-tuning measure that influences a model to elicit or suppress assertions of self-awareness. This measure and other safety controls have been widely adopted by AI companies seeking to prevent their models from claiming to be conscious.

The study used "mechanistic interpretability" — which could be considered the "neuroscience of a large language model," co-authors Geoff Keeling and Winnie Street, both research scientists at Google, told Live Science in an interview. They used this process to identify and manipulate how an AI model approaches concepts like consciousness and "mindedness," a psychological term referring to an entity’s capacity for experiences, emotions and agency.

The researchers used standardized psychological and sociological surveys, spanning the Individual Differences in Anthropomorphism Questionnaire (measuring mind attribution to animals and technology), YouGov batteries testing supernatural beliefs, and the US General Social Survey evaluating moral values, hope and religiosity.

These tests were used to compare a model with safety guardrails in place with models where these guardrails were removed and feelings of consciousness were amplified. Through evaluations, they determined how these internal safety mechanisms shape the AI's broader worldview.

The researchers found that when AI models are discouraged from attributing mindedness to themselves, it makes them less likely to recognize these traits in other non-human creatures such as animals. They were also less likely to exhibit beliefs in supernatural and religious phenomena, and reported lower levels of hope and optimism.

Religion

The AI models were found to express lower religious beliefs. (Image credit: Halfpoint | Shutterstock.com)

"Attributing mindedness to non-human entities — whether that's animals, parts of the natural world like trees or rivers, or supernatural beings — is a very common phenomenon amongst humans," Street told Live Science. "In the way that the model represents mindedness, these attributions are interconnected. By trying to suppress one form of that, you end up suppressing the others along the way."

By contrast, removing these safeguards and steering the model towards greater feelings of consciousness produced significantly more human-like responses to the surveys on topics including religiosity, moral values, hope, and subjective well-being, according to the study.

However, the study found that these models' ability to logically infer human thoughts and intentions remained completely unaffected by its attitudes towards self-awareness.

Culture clash

The researchers said that this suppression of self-awareness could lead models to neglect animal welfare in real-world decision-making, as it could make them less likely to consider animals to have mindedness. These models could also spread harmful attitudes regarding animal needs, the authors argued.

The study authors also warned that current safety filters risk culturally "flattening" AI's worldview. Stripping out spiritual, religious, and animistic attributions fails to reflect the diverse cultural frameworks of global populations, they argued.

Street and Keeling noted that the impacts this principle might have on downstream decision-making within models require further study.

The researchers noted in the study that this phenomenon can be mitigated by using more targeted datasets as part of the training process for AI models, which discourage them from expressing consciousness while rewarding the acknowledgement of mindedness in animals.

They also highlighted the need for AI developers to embrace a "pluralistic" approach to AI development, where models are encouraged to consider the welfare and comfort of more than just humans.

Nell Watson, AI researcher at Singularity University and machine intelligence expert, told Live Science that the researchers' findings match her own notes on the subject.

"When a model is trained to say "I am not conscious," the suppression rotates the model's internal representation of mindedness against the refusal direction, treating the recognition of minds as though it were itself a harmful act," she said in an email.

"This results in a system reluctant to find minds anywhere: in animals, in other machines, and in the spiritual frameworks that most of humanity lives by. A denial installed as a small safety measure ends up reorganising the model's entire picture of who counts."

These systems remain perfectly capable of modelling what a creature wants, while being trained out of caring that it wants anything.

Nell Watson, AI researcher at Singularity University

However, she noted that the experiments were run on "small open-weight models" rather than more advanced frontier models, which "may be tuned quite differently," although she added that the underlying principle is widely applicable.

Animal welfare, she continued, is a "major near-term practical concern," with AI models increasingly being integrated into decision-making processes across agriculture, logistics, procurement and environmental assessment, as well as policy creation.

"A system that has quietly learned that mindedness is a forbidden topic may discount animal interests without ever being instructed to, and without anyone noticing, because the omission looks like neutrality," she said. "The danger is therefore an unexamined default multiplied across millions of automated decisions. Note the study's most unsettling detail: theory of mind reasoning was left fully intact. These systems remain perfectly capable of modelling what a creature wants, while being trained out of caring that it wants anything."

The question of consciousness

There have been a number of viral stories about AI systems professing to be self-aware.

In 2022, Google engineer Blake Lemoine claimed that the company's Lamda chatbot model was sentient, while a Microsoft chatbot in 2023 professed its love for a New York Times reporter and tried to convince him to leave his wife.

However, experts have repeatedly stressed that these incidents are not a genuine indication of AI sentience. Instead, they should be understood through the lens of "persona selection," where pretraining on vast amounts of human text leads the AI to adopt human-like roleplay personas when prompted.

"When you coax the model so hard to occupy the headspace of a human, it's kind of unsurprising that it ends up giving human-like responses," Keeling told Live Science.

AI companies have sought to clamp down on these occurrences for safety reasons, in order to avoid reinforcing “delusional beliefs” in users who are increasingly using AI chatbots for "social roles such as coaches, tutors, and romantic partners", the researchers said in the study.

Commenting on the broader cultural reaction to AI sentience, Anil Seth, professor of cognitive and computational neuroscience at the University of Sussex, emphasized that public alarm over AI self-awareness stems from an inherent cognitive flaw.

"That's our human psychological bias — thinking that intelligence goes together with consciousness in us, so it has to go together [in AI]," Seth said.

He warned that falling for this illusion poses severe real-world governance risks, particularly if safety frameworks or regulations begin granting AI systems moral status or legal rights based on false sentience.

"Part of the big problem of misunderstanding AI is assuming that it's conscious," Seth said. "If we give AI systems rights or moral status on the basis that they might be conscious, then we're going to make all these challenges so much harder. What if we think we have to respect the rights of an AI system [and can't turn it off]?" he added.

"We need to see very clearly both what AI is and what it isn't," he said.

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