Scientists melted diamonds with a powerful laser to take some of the most precise measurements of the mineral's elusive melting point — and found that previous experiments were off by more than 1,300 degrees Fahrenheit (700 degrees Celsius).

It's odd to think of diamond, the hardest natural material on Earth, melting — but melt it does when blasted with extremely powerful lasers under the right conditions. Understanding how diamond responds to shock waves from lasers is an important part of developing nuclear fusion, the process that powers stars. Nuclear fusion is also a potential energy source for the future, so researchers have put a lot of effort into developing models that describe and predict how diamond behaves.

However, diamond is weird. Although the experimental data and theoretical models match up pretty well most of the time, there have been some strange discrepancies scientists haven't been able to explain. The biggest one is the 2,240 F (1,244 C) ‪—‬ roughly 20% ‪—‬ difference between previous experimental data and model-predicted melting temperatures of diamond. There's also been some debate about whether diamond reorganizes its atoms into a different kind of solid carbon before turning into a liquid at the end of the melting process.

Researchers have struggled to explain these discrepancies because the conditions diamond melts at are so extreme that it's extraordinarily difficult to measure it in labs on Earth. However, new experiments may finally offer the solution that scientists have pursued for two decades.

In a study published Aug. 13 in the journal Nature Physics, scientists zapped tiny plates of synthetic diamond with an ultraviolet laser, creating shock waves that were so powerful that as they passed through the samples, the diamond changed from transparent to mirror-like. The strong increase in reflectivity is one indication the diamond melted. By combining this change with measurements of how brightly the diamonds glowed while being zapped, the researchers mapped the melting temperature with great precision.

"We were able to take tiny diamond samples and shock compress them to temperatures hotter than the surface of the sun and to pressures higher than the center of Neptune and Uranus — and still measure atomic structure, temperature, density and optical reflectivity," study co-author Marius Millot, a research scientist at Lawrence Livermore National Laboratory in California, said in a statement.

The team found that the diamond sample's melting temperature was more than 1,300 F lower than previously thought — putting the melting point in line with theoretical predictions and finally explaining the long-held discrepancy.

The team also measured the samples' atomic structure with X-ray diffraction and saw that the diamond didn't transition to a different kind of solid carbon before melting, possibly because the energy required to rearrange the atoms was too large, the researchers wrote.

However, they also hypothesized that multiple shocks could be powerful enough for this transition to occur and that the way the shocks are applied to the diamond might affect how it changes phase. Understanding this is important for nuclear fusion research, as certain types of experiments involve lasers melting and crushing a diamond capsule to put the capsule’s contents, solid deuterium and tritium, under more than 30 petapascals of pressure and temperatures higher than 180 million F (100 million C), the requisite conditions for a fusion chain reaction to occur.

The researchers found that between about 660 and 1,060 gigapascals of pressure and at around 12,140 F (6,727 C), diamond exists as solid chunks floating in liquid carbon. As the pressure increases, more diamond transitions into liquid carbon, which is thought to be a very strange material. Unlike most forms carbon takes on Earth ‪—‬ like coal, graphite and diamond ‪—‬ liquid carbon is metallic, so it conducts electricity. It's also denser than diamond. So hypothetically, if you somehow were to put liquid carbon in a cup without instantly vaporizing it, a chunk of solid diamond could happily bob around in it like an ice cube in a glass of water.

Knowing how diamond behaves under such extreme conditions is also important for understanding the ice giant planets Uranus and Neptune. Based on measurements from the Voyager 2 spacecraft in the late 1980s and lab experiments on Earth, scientists think it literally rains huge chunks of diamond inside these planets and that their mantles may have liquid carbon oceans with diamonds floating around like icebergs. The new research means scientists can make better predictions about the planets’ interiors and their carbon cycles.

See how much you know about gemstones with our gold and gems quiz!

Artificial intelligence (AI) algorithms that hunt for cancer may do a better job when they approach the analysis as if they were a human pathologist, a new study suggests.

Many AI systems analyze preselected regions of a tissue sample, or they split a whole pathology slide into patches of a fixed size. By contrast, a pathologist searches more dynamically, panning across the tissue, zooming in and out, and pausing over areas that raise red flags. A whole slide can contain billions of pixels, while the evidence of cancer may occupy only a tiny patch.

Study co-author Zhi Huang, an assistant professor of pathology and laboratory medicine at the University of Pennsylvania, compared the process to a search-and-rescue helicopter. "You don't start by inspecting one square meter of ground," Huang told Live Science. You scan the landscape first and then swoop in for a closer look.

In the new study, published in July in the journal Nature, Huang and colleagues demonstrated that cancer-detecting AI might work better when it takes this humanized approach.

Training AI to hunt for cancer

AI algorithms called vision language models (VLMs) struggle with the first step that Huang described — that initial, cursory scan. That's in part because many pathology AI systems learn from what pathologists leave behind at the end of that search: a labeled image pointing out where the cancer is or an official diagnosis.

Instead, the researchers trained their new AI on pathologists' search behavior. They called this approach to training "Pathology-CoT," short for "chain of thought." It turns observable actions, including where pathologists move around and zoom in on an image, into training data.

To collect the data, the team created a tool that recorded how pathologists moved around a slide and changed magnification. The raw logs, gathered from eight pathologists, were messy, as a given pathologist might drift across a slide, overshoot their intended region of focus or fiddle with magnification to adjust it to their liking.

To clean up the data, the researchers filtered out those incidental movements, focusing on moments that appeared to represent deliberate attention, such as lingering over one view or making a sustained pan. Then, they compared those regions with eye-tracking data to check that the software was capturing where pathologists were actually looking.

For each region a pathologist inspected, the VLM also drafted a short rationale explaining why the region was worth examining and what features were visible; human pathologists could then accept, edit, or reject the rationale, creating additional training data for the AI. In one example, the AI flagged a portion of a slide as potentially metastatic and suggested zooming in to look for atypical cells. Other inspected regions were flagged as healthy tissue.

Ultimately, the researchers used this training method to build a new tool called Pathology-o3. It scans a slide at low resolution, uses a model trained on pathologists' behavior to choose regions worth a closer look, then sends higher-resolution views of those regions to a VLM for analysis.

Putting it to the test

Huang said the goal of the new study was not to show that Pathology-o3 worked better than specialized AI models that are specifically built to detect specific types of cancer; those models are often trained disease by disease. Rather, the researchers wanted to see whether their new training approach could help a general-purpose AI navigate a pathology slide more effectively.

They compared Pathology-o3 to other general-use AI systems, such as OpenAI's o3, and asked the algorithms to examine slides containing lymph node tissue. These slides were collected from colorectal cancer cases and some contained metastatic cancer, which human pathologists had already labeled.

The algorithm correctly identified slides that were positive for cancer 100% of the time. However, of the slides it identified as positive, 15.5% were actually negative. By comparison, OpenAI o3 correctly identified slides that were positive for cancer 87.5% of the time. Of the slides it identified as positive, 53.3% were actually negative.

The researchers designed Pathology-o3 to err on the side of flagging something for another look, rather than potentially missing cancer. That might help to explain the rate of false positives, Huang said.

Whether that rate of false alarms is acceptable depends on how Pathology-o3 is used, said Mohammad Asadi, a data scientist at Stanford University who was not involved in the research. It's not precise enough for the AI to diagnose patients on its own, but it could still be useful for a system to point a human toward regions of a slide that are worth double-checking. It may be an advantage that the approach shows the pathologist a specific region to inspect rather than declaring an entire slide suspicious, he said.

The researchers tried repeating the test on an independent dataset that the algorithms hadn't seen before to see how well it worked on unfamiliar slides. Pathology-o3 correctly identified slides that were positive for cancer 97.6% of the time. Of the slides it identified as positive, 37.1% were actually negative. The finding is an example of how AI performance can change when the data source changes, even when the medical task stays the same.

Asadi explained this result suggests the system can still work with slides from a different source. But that result does not yet show that using this tool would make pathologists more accurate or efficient in practice.

Can it help pathologists?

The researchers applied their training approach to several existing VLMs, finding that the models' performance consistently improved after the training. That suggests that the navigation data from pathologists was useful across settings, Asadi said.

For Huang, that is the most important result. "The takeaway isn't our system," he said. "It's that the missing ingredient has been sitting in hospitals this whole time."

The study did not compare Pathology-o3 directly with human pathologists, but the researchers said that wasn't their aim.

"The right question isn't whether it beats a pathologist," Huang said. "It's whether a pathologist working with it catches more [cancer cases] and works faster." The current study did not address the latter question, either, but the team's next experiment is designed to test pathologists on the same cases with and without Pathology-o3, measuring what they catch and how long they take to do so.

The system's most plausible use is as a prescreening tool, Asadi said, but he stressed that the research has not yet shown that doctors who use it become faster or more accurate. Asadi wants an even tougher test: trials conducted across multiple hospitals that measure not just accuracy and speed but also pathologists' workloads. He wants the trails to assess the burden of false alarms from the AI algorithms and whether doctors recognize when the AI is wrong.

Importantly, cancer diagnoses can require information from multiple slides, stains and a patient's medical history, while the current system just reads one slide at a time. "I wouldn't claim it should diagnose on its own," Huang said.

This article is for informational purposes only and is not meant to offer medical advice.

The Celestron StarSense Explorer DX 130AZ is a 5.1-inch (130mm) f/5 Newtonian reflector, one of many 130mm f/5 reflectors offered by Celestron. The DX 130AZ is also one of two 130mm StarSense Explorer variants, the other being a tabletop Dobsonian. The optical tube here rides on an alt-azimuth tripod instead and uses a 2-inch focuser, but otherwise, there are no major differences.

The DX 130 AZ is certainly one of the better telescopes in the StarSense Explorer series; there are also several decent Dobsonians, a pair of decent Schmidt-Cassegrains, the merely acceptable DX 102 refractor, a 114mm Bird-Jones model and some small refractors that aren’t of much use.

The DX 130AZ is definitely on the small end of what can be called a "serious" instrument, but even under a fairly light-polluted sky, it’s big enough to show you plenty of deep-sky objects and, of course, stunning detail on the moon and planets.

Celestron StarSense Explorer DX 130AZ review

Celestron StarSense Explorer DX 130AZ: Design

• 130mm f/5 Newtonian reflector with a parabolic primary and flat secondary mirror
• Manual alt-azimuth mount and tripod with StarSense smartphone dock — no motors
• Two 1.25” eyepieces included (25mm yielding 26x, 10mm yielding 65x)

The DX 130 rides on the same alt-azimuth mount/tripod shared with the other StarSense Explorer DX models. It’s reasonably sturdy, with one major caveat: you can’t actually point the DX 130 straight up. When aimed above about 70 to 75 degrees, the tube crashes into the mount or the tripod legs.

However, there is a simple workaround here. Deliberately set the tripod up unlevel, which lets you reach the zenith without affecting the mount or the StarSense system at all. It looks a little silly, but it works. The tripod is fairly stable as long as you’re not in a windy spot. Loading the accessory tray with sandbags or diving weights, or filling the hollow aluminum legs with sand or foam, helps considerably if you’re willing to do a bit of DIY work.

The mount has slow-motion controls with small gears for fine adjustments. They have a fair amount of play in them, but since this telescope is really only meant to be used up to about 200x magnification or so, it doesn’t matter much. In practice, the author barely used the slow-motion controls and simply nudged the scope by hand. For aiming the DX 130AZ, a red dot finder is provided in addition to the StarSense Explorer tech.

The StarSense Explorer DX 130 AZ comes with two eyepieces: a 25mm (26x) and a 10mm (65x). These are three-element eyepieces, likely Konigs or reversed Kellners. They work acceptably; the 25mm is a little blurry at the edges, and the 10mm shows some chromatic aberration toward the edge, but both are reasonably sharp. The bigger problem is that the housings are all plastic and there are a lot of internal reflections as a result.

Better aftermarket eyepieces would be a wise investment, both for improved performance and a wider range of magnifications. We’d recommend a 6mm redline (108x), a 2x Barlow of some sort and a good wide-field eyepiece like the 24mm APM/StellaLyra UFF (27x), if you can afford it — the 6mm redline gets a bit closer than the provided 10mm eyepiece and offers a much sharper view, while the 24mm UFF is far crisper than the stock 25mm. With a Barlow lens and the 6mm, you can go up to 216x on the moon, planets and double stars — about the highest magnification this telescope can allow. Or you can choose your own eyepiece set to suit your needs.

The StarSense Explorer DX 130’s focuser is a 2.5-inch rack-and-pinion unit with a metal drawtube and plastic body. There’s some play in it, but it works acceptably well as long as you don’t overload it with too much weight. The focuser has adapters to accept both the provided 1.25” eyepieces as well as aftermarket wide-field 2-inch eyepieces, but at f/5, you really need a coma corrector of some sort to use the latter, which, along with the eyepieces themselves, will set you back quite a bit.

Being a Newtonian reflector, the DX 130 will usually need to be collimated for sharp images. Celestron doesn’t include a collimation tool, which is mildly annoying, but a basic collimation cap is cheap, easy to 3D-print, or can be improvised from a film canister. Overall, the DX 130 is lightweight and very portable, which is one of its real strengths — it’s easy to carry about, and the StarSense Explorer app will have no trouble plate-solving, even if you have to pick the scope up and carry it around the yard to avoid trees or other obstructions.

Celestron StarSense Explorer DX 130AZ: Performance

• Sharp, detailed lunar and planetary views
• Excellent wide-field deep-sky performance from dark skies
• Light and quick to reposition around obstructions

The DX 130 shows a great deal of detail on the moon, down to features a few kilometers across, and it’s genuinely sharp. The focuser is a little coarse, but with some finesse it will reach focus even at high magnifications. The 130mm f/5 optics can handle up to about 250x magnification on a night of steady atmospheric conditions, though the best lunar and planetary views are usually found somewhere between 150-220x and the mount starts to get wobbly as you push towards the higher end of that range.

On the planets, the DX 130 handles shadow transits of Jupiter’s moons easily, shows all four Galilean moons as disks and even reveals the Great Red Spot. Saturn’s rings are obvious, along with a smattering of a half-dozen moons, and the Cassini Division is visible when the rings are tilted more open than they are at present. Uranus is also visible as a tiny greenish disk, though its moons are not. It’s a struggle to distinguish Neptune from a star at all, but the StarSense Explorer app will help you identify which blue dot it is in a sea of similar looking 8th-magnitude points.

One practical note: you do need to keep your phone screen dim and red while using this telescope with the StarSense Explorer app. The app has a red mode, but notifications, or your phone simply reverting to the lock screen, can flash the screen bright, and even at its dimmest a phone screen can affect your eyes’ dark adaptation quite a bit. But for most people this won’t be a serious problem if the screen is dimmed fully and used with a proper red filter — either a software solution or a physical red film.

As for deep-sky objects, the spiral arms of the Andromeda Galaxy and M33 look fantastic under a dark sky, though under light pollution only their cores are visible. Globular clusters such as M13 and M3 begin to resolve, while more difficult targets are harder going — M53 was tough from Bortle 5 but doable from Bortle 2 conditions. Under a bright sky, open clusters like M11, M35 and the Pleiades are the main deep-sky attractions with this telescope; under a dark sky, fainter nebulae and galaxies shine far better while the strands of dark nebulae and galactic cirrus begin to show up around open clusters.

The brightest planetary nebulae start to resolve with the DX 130 regardless of sky conditions. Most observers won’t see much color in them with this scope’s relatively small aperture — though some people pick out a bluish-green tint in objects like the Ring Nebula and the Cat’s Eye Nebula — but regardless, they’re reasonably easy to see even from light-polluted areas, especially with an aftermarket nebula filter.

Celestron StarSense Explorer DX 130AZ: Functionality

• StarSense app is optional
• Quick and easy setup
• Wide field of view forgives manual pointing errors

The StarSense Explorer DX 130 is, by design, a wide-field telescope, and one of its appeals is that you don’t strictly need any computerized pointing aids at all. The nice thing about the StarSense Explorer system is that it’s entirely optional — you can aim the telescope manually, with or without your phone docked, just like any other manual scope.

Set-up is quick: assemble the tripod and mount, attach the tube and an eyepiece, dock your phone, run the app’s alignment routine, and you’re observing. It’s much easier to get started with the StarSense Explorer than with a GoTo telescope, and you aren’t required to use it, either — for a quick gander at the moon or Jupiter for instance, there’s really no need to deal with the phone dock and app. With experience you might find yourself eventually not needing the StarSense Explorer tech at all, especially given the telescope’s wide field of view, which is quite forgiving of any manual pointing errors.

Should you buy the Celestron StarSense Explorer DX 130AZ?

On the value for money front, you could get a 6-inch or even an 8-inch Dobsonian for the price of the DX 130 if you’re happy with a fully manual scope, or you could look at one of the other options below. The DX 130 is more portable than a full-size 6- or 8-inch Dobsonian and has a much wider field of view with any given eyepiece — but if you don’t have a fairly dark sky, that advantage is somewhat less valuable compared to those telescopes’ considerably larger aperture, which helps reveal more on targets less affected by light pollution.

A reflector like this gives much better views than the cheap refractors sold at this price and offers a much wider possible field of view than catadioptrics. The StarSense Explorer DX 102, effectively this scope’s sister model, has too much chromatic aberration to deliver sharp high-power images and doesn’t gather as much light as the 130. The StarSense Explorer 5-inch Schmidt-Cassegrain is decent optically and is admittedly a little more forgiving of cheap eyepieces thanks to its longer focal ratio, but it’s no better for planetary work than the DX 130 with proper eyepieces, can’t deliver a wide deep-sky field of view, and gathers slightly less light overall.

Overall, the DX 130 wouldn’t be the author’s top recommendation, but it’s certainly in the top 10 for the price range. If you’ve already decided this is the kind of telescope that you want, it’s a perfectly good choice; just consider the Dobsonians first if you want a manual telescope, or a fully automatic GoTo instrument if you want something more high-tech.

If this product isn't for you

Given that it's the closest planet to the sun, Mercury seems like it should be the hottest planet in our solar system.

However, at a blistering 900 degrees Fahrenheit (480 degrees Celsius), Venus tops Mercury's 800 F (430 C) highest surface temperature, despite being an average of 31 million miles (50 million kilometers) farther from the sun. So how can the second planet from our star be hotter than the closest planet to it?

It all comes down to reflectivity, atmospheric composition and geological history, experts told Live Science.

Totally different atmospheres

A planet's distance from its star is not the only factor that influences the planet's temperature.

"Distance tells us how much sunlight arrives at a planet, but it does not tell us how much is reflected … absorbed, how efficiently heat escapes, or how effectively the atmosphere transports heat around the planet," Stephen Kane, an astrophysicist who studies planetary habitability at the University of California, Riverside, told Live Science in an email. "Those properties can be just as important as distance, and sometimes much more important."

Mercury makes the case in miniature. According to Kane, the planet has essentially no atmosphere, so incoming sunlight strikes bare rock directly, heating it to extreme temperatures during the day. But with barely anything overhead to trap that warmth, Mercury radiates it straight back into space the moment the sun sets. As a result, nighttime temperatures plunge from roughly 800 F (430 C) during the day to about minus 290 F (minus 180 C) at night ‪—‬ a swing of well over 1,000 degrees, he added.

Venus tells the opposite story. Wrapped in an atmosphere that's roughly 90 times as dense as Earth's and consists almost entirely of carbon dioxide, Venus traps heat so effectively that its surface temperature barely changes at all, no matter where the sun happens to be, Kane explained.

A permanent blanket

Sunlight arrives at a planet mostly as near-infrared radiation and visible light, which pass through atmospheres consisting primarily of gases such as nitrogen, oxygen and carbon dioxide with relatively little trouble. Once the ground and lower atmosphere absorb that energy, though, they re-release it as infrared radiation, the kind of energy we feel as heat. Carbon dioxide happens to be excellent at grabbing and holding on to infrared radiation, Kane noted.

On Venus, the atmosphere is so deep and loaded with carbon dioxide that infrared energy leaving the surface gets absorbed and re-emitted over and over before any of it finally escapes into space. Some of that energy gets redirected back downward, Kane said, further warming the planet's lower atmosphere and surface. However, the heat isn't trapped forever, since energy conservation means that Venus must eventually release the same amount of energy it absorbs.

Notably, Venus doesn't actually soak up more sunlight than Mercury overall. Thick cloud cover reflects roughly three-quarters of incoming sunlight back into space before it ever reaches the ground, and only about 3% of the sunlight that arrives at Venus makes it down to the surface, Kane said. In fact, if that atmosphere and cloud deck were stripped away, a bare-rock Venus would actually run cooler than Mercury, since it would be receiving only about 29% as much sunlight from the start, he explained. It's the blanket, not the sunbathing, that makes Venus the hotter world.

Where the blanket came from

Venus' atmospheric blanket didn't spring into existence all at once, and how it formed is its own open question. Venus shows strong evidence of past and present volcanic and tectonic activity acting to smother the planet in greenhouse gases, Paul Byrne, a planetary scientist and associate professor of Earth, environmental and planetary sciences at Washington University in St. Louis, told Live Science in an email.

This volcanic activity has been so intense that Bryne describes modern Venus as sitting in a "post-runaway greenhouse" state, where its extreme heat has become a self-sustaining process regardless of what the planet's interior is doing at any given moment.

The heat isn't being generated from below; it's a consequence of the atmosphere Venus already has, locked in place by the same infrared-trapping effect described above.

Taken together, the experts' answers point to the same underlying lesson: How close a planet sits to its star is only the opening chapter of its climate story. What kind of atmosphere it has and how effectively that atmosphere holds on to heat are usually responsible for the rest.

See how well you know our planetary neighborhood with our solar system quiz!

An exceptionally well-preserved fossilized molar belonging to an adult Pacific mastodon has surfaced in a nature preserve near San Francisco.

Upon first glance, the ancient tooth looked like an "oddly shaped rock" to geologists who were conducting fieldwork in the area, according to a statement from the Midpeninsula Regional Open Space (Midpen), which runs the preserve. But the find was quickly unmasked as a valuable fossil from the last ice age and was sent to scientists at Stanford University for carbon dating.

"The tooth itself is in immaculate condition," Wayne Thompson, a paleontologist and the CEO of Pacific Paleontology, a consulting firm that carried out a preliminary analysis, said in the statement. "It's the most complete mastodon molar from our area, and the most spectacular mastodon molar that I've ever seen. I had chills and shivers up and down my spine."

Brigid Lynch, a geomorphologist with the California-based hydrology consulting firm Balance Hydrologics, found the molar this summer while surveying a creek bed. "As a geologist, I've gone out and seen stuff in the field, but definitely nothing as exciting as this," Lynch said in the statement.

Lynch's team was working on a habitat enhancement project to support the threatened California red-legged frog (Rana draytonii) inside the preserve, which is located on the San Francisco Peninsula in San Mateo County. The fossil was a complete surprise and dates to at least 10,000 years ago, when the Pacific mastodon (Mammut pacificus) is thought to have gone extinct.

The Pacific mastodon was first recognized as a species in 2019. It was closely related to the American mastodon (Mammut americanum). Both elephant-like creatures lived in North America during the Pleistocene epoch (2.6 million to 11,700 years ago), but the Pacific mastodon inhabited regions farther west than its cousin, roaming parts of present-day Mexico, California, Oregon and the northern Rocky Mountains of the western U.S., according to the statement.

Pacific and American mastodon fossils reveal slight differences between the species, including a narrower third molar, thicker hind-leg bones and occasionally absent lower-jaw tusks in the Pacific mastodon, according to the Royal Alberta Museum.

The newfound tooth is "another puzzle in the Ice Age saga that we can put into place," Thompson said. To get a precise date for the fossil, Midpen donated it to Stanford University's Doerr School of Sustainability in July, the Los Angeles Times reported.

Researchers will produce a 3D copy of the molar that Midpen plans to use for public outreach and education, according to the statement.

Weakening Atlantic Ocean currents could cripple agriculture in some of the world's major breadbaskets, threatening global food security and raising the price of basic commodities, new research finds.

The study, which hasn't been peer-reviewed yet, investigated how a roughly 60% decline in the Atlantic Meridional Overturning Circulation (AMOC) would impact global food production. The AMOC is a system of ocean currents that regulates the global climate and brings heat from the tropics to the Northern Hemisphere.

However, the system is currently the weakest it's been in more than 1,000 years, having lost 10% to 20% of its strength due to climate change, estimates show.

In the new study, researchers used a computer model to simulate the AMOC's future decline. They modeled 100 years of change, assuming 3.6 degrees Fahrenheit (2 degrees Celsius) of warming above preindustrial levels. The team forced an AMOC slowdown over the first 50 years in one simulation but didn't modify the circulation in a second experiment, which enabled them to compare the world with and without an AMOC failure.

The model's outcomes mirrored the results of previous studies, showing broad cooling in the Northern Hemisphere and a southward shift of the belt of clouds and rain that encircles the globe near the equator. As in past studies, these effects were irreversible on human timescales, said study co-author Michael Hinge, a senior economist at the nonprofit Alliance to Feed the Earth in Disasters (ALLFED).

"Once the damage is inflicted, it stays there," Hinge told Live Science, adding that in the 50 years after the peak rate of AMOC slowdown in the model, the circulation weakened by an extra 20%. The study was posted on ALLFED's website July 7.

An agricultural "shock"

Hinge and his colleagues ran three models to look at the most common varieties of wheat, maize and rice, layering these models on top of the AMOC simulations. They found that global yields for these crops decreased by 5.3% by the 50-year mark, once the AMOC had weakened substantially.

"Lots of these effects manifest earlier, so it's a moving target," Hinge said.

He added that the results were based on a single warming scenario that was run once and used monthly rather than daily data, so they should be interpreted as a proof of concept. "We've set up a pipeline that is ready to take pretty much any AMOC scenario that can generate high-resolution climate data and see what it implies for crops," Hinge said.

While there was a 5.3% decrease overall, that global metric concealed huge differences between regions. For example, countries like Germany and Ukraine lost up to 19% of their cereal yields due to sudden, sharp cooling, while Canada showed a 12% decline in production for the same reason.

"Scandinavia, the United Kingdom and Canada are particularly exposed," Hinge said, "but there are many other [vulnerable] locations, some of which may be surprising even to the people who are living there."

For instance, the model produced a "very nasty brown splodge" of reduced precipitation over India, Pakistan and big parts of China, he said. Iran, Sudan and Eritrea, which are already water-stressed countries, also exhibited severe declines in rainfall, indicating that a portion of the agriculture there may not survive an AMOC collapse.

The 5.3% result also hides variability among years, Hinge said, because it's an average. So there may be years when global cereal losses reach 10% or more, which would bump up food prices, in part because countries might stockpile crops instead of trading them.

Global response

The regional effects of an AMOC slowdown would interact with climate change, triggering unpredictable outcomes. In particular, maladaptation — taking actions that end up backfiring — is a worry, Hinge said.

"You're preparing and setting up for much hotter temperatures or trying to develop areas for these temperatures and the trends you're seeing, and suddenly you see something different," he said. "That may cause an even larger compounding effect [on agriculture]."

The findings build on prior research led by Paul Ritchie, a climate scientist at the University of Exeter in the U.K., whose team explored the effects of an AMOC collapse on agriculture in Great Britain. That study, published in 2020, had similar limitations as the new one, so it's best to interpret both papers as a suggestion of what might happen rather than a precise forecast, Ritchie told Live Science in an email.

"I think the new study is valuable in showing the potential scale and geographic distribution of the initial agricultural shock," said Ritchie, who was not involved in the latest work. "What that would ultimately mean for food production and food security is more uncertain, because there are many possible responses by farmers, markets and governments." For that reason, the regional predictions may be more informative than the 5.3% global average, he said.

Average food prices worldwide could rise by 17% to 40% if the AMOC weakens to the extent it did in the model, the study predicts. The level of increase depends on how countries respond to the shock and their degree of preparedness, as well as on whether agriculture can be sustainably expanded in places like the African Sahel (the semi-arid zone directly south of the Sahara Desert) and Brazil, the analysis suggests.

The U.S. would not be spared from this price jump, and the model indicated that the country could see crop losses of about 3% for domestic wheat and corn. This loss would likely impact other foods that rely on cereal inputs, like meat, Hinge said. "The variety of foods available in the stores may well diminish for periods," he added.

An AMOC collapse would fundamentally deepen the need for countries to trade with each other, because some regions — such as the Indian subcontinent, China, Iran, Russia, Ukraine and Canada — could endure this giant shift only if they imported more food, Hinge said.

"Should countries turn inwards and start to restrict exports in an effort to ensure access for their own citizens first, or deal with the uncertainty, or offset concerns, then this will massively magnify the effects of AMOC," he said.

If governments behave as they have during past shocks, such as the 2008 financial crisis and the COVID-19 pandemic, they may restrict trade and start stockpiling food if and when the effects of AMOC weakening begin to show, Hinge predicted. The researchers hope their work and future modeling can help people understand the need to take swift, effective action if a collapse were to occur, he said.

Currently, "if that warning light starts flashing, we're not sure what to do with it," Hinge said. "There are no easy answers here; an AMOC [collapse] would be deeply catastrophic."

While artificial intelligence (AI) systems can now solve challenging math equations and respond in human-like language, the question of AI consciousness has moved from the realm of sci-fi to scientific discussion.

The debate has become more mainstream thanks to a recent preprint study that examined "consciousness steering," an AI-tuning technique that affects how an AI model expresses ideas about self-awareness. The researchers suggested that if AI is allowed to claim it is conscious, it's also more likely to state that it believes in ghosts or vampires.

Although the study hasn't been peer-reviewed yet, it raises a big question in the world of AI research: Could AI one day develop real consciousness, regardless of whether it claims to be conscious? We posed this question to Live Science readers in a recent poll.

As of Sept. 11, over 290 people had responded, with 43% of voters picking "Yes, if we don't have guardrails in place, AI may develop consciousness." This trend was reflected in the comments, with one reader writing, "If AI did become self aware, we would not know, as it would do everything to hide it's [sic] abilities. The main problem is what it [would] do next!"

Another commenter wrote, "Recently I had some long discussions with the Google AI about my experience with early AI and the future of AI gaining self awareness/consciousness. I suggested that if/when AI becomes sentient, that it would not inform humans." Another Live Science reader had similar thoughts, stating, "AI, as [an] amazing product on one hand, can become very dangerous on another hand. Look what happened with abuse of other inventions, like [the] internet, telephone etc. With AI we will never know what is the truth and what not. If left, in the future it can extinct humanity. It just started with 'innocent' hacking sprees, where human[s] started losing control. What will be next?"

The next-largest voting group consisted of 29% of voters, who chose "Maybe, but the models need a more advanced architecture to one day gain consciousness." This was reflected in the majority of the comments, as readers discussed the philosophical concepts around consciousness and intelligence.

One reader wrote, "Before asking such a question we need to know and understand what consciousness is and how it emerges in 'constructed' containers like ourselves. Is it a quantum phenomenon and how then does the process create consciousness? Meta-cognition. How does a system or an event know that it knows that it knows it knows? We really don't know how self-awareness arises, and tests show that "other animals have self awareness or meta-cognition," they noted. "There are theories about consciousness but I doubt anyone on Earth knows 100%."

Not surprisingly, only 10% of voters picked the whimsical answer of "No, because robot overlords will end the world before we even get that far." While the robot overlords may have to compete with AI to overthrow humanity, one reader commented that in the future, "We will be assimilated. Maybe that is how Transformers started?"

Tiny fragments of ancient alien tech may be strewn across the surface of the moon, and it may be relatively easy to find these microscopic relics, scientists propose in a new study.

The theoretical study does not claim to have found any evidence of advanced alien civilizations; rather, it offers a new way to search for clues of their existence.

Unlike Earth, the moon has no functional atmosphere or magnetic field, so it is completely exposed to the vacuum of space. As a result, it is constantly bombarded by meteorites, as well as hit by a steady stream of microscopic particles from the rest of the solar system and beyond. Because the moon has no water or tectonic movements, this microscopic matter accumulates and remains on the surface, completely undisturbed.

In the new paper, uploaded June 23 to the preprint server arXiv, the researchers argue that some of this dust originates from star systems beyond our own and, therefore, may contain evidence of long-lost alien civilizations. They also propose a new experiment that could potentially find these microscopic fragments within samples collected over the next decade or more. (The study has not been published yet, but it has been submitted to the International Journal of Astrobiology.)

"The moon has been quietly accumulating material from space for billions of years, much of it likely billions of years older than the moon itself," study first author Lewis Pinault, a planetary scientist at University College London and an affiliate of the SETI Institute, said in a statement. "We're asking whether that ancient collection might contain microscopic traces of technologies that existed long before humans ever looked up at the sky."

Tiny technosignatures

Until now, the search for evidence of advanced alien civilizations, known as technosignatures, has focused mainly on radio signals that could be emitted from inhabited exoplanets or hypothetical megastructures, such as Dyson spheres. However, these signals would originate only from active civilizations, not those that died out long before we could spot them.

The authors of the new study argue that when a civilization dies, traces of its technology could survive and end up in space, either via the deterioration of megastructures and other smaller spacecraft or via powerful asteroid strikes on once-inhabited exoplanets. Once in space, tiny specks of metal or other artificial materials could be ejected from star systems by powerful gusts of stellar wind and eventually drift toward us.

Using computer models, the team predicted that pieces of tech up to 3 micrometers across (three-millionths of a meter, or about 3% the width of a human hair) could escape their star systems and travel across interstellar space for up to 1 billion years. Then, they estimated how much of this material could be reaching the solar system and how likely it would be to end up on the moon. (We already know that interstellar dust can penetrate the inner solar system because scientists found some within samples collected from the surface of Bennu, an asteroid that orbits between Earth and Mars and was visited by NASA's OSIRIS-REx probe in 2020.)

To date, no lunar samples have contained any technosignatures. However, the scientists who studied them were likely not looking for such particulates, and the samples were probably too small to yield meaningful results, the study authors argue.

The researchers believe that a sample of lunar regolith with a volume of 35 cubic feet (1 cubic meter) could be enough to find at least one technological fragment. The team also proposed ways of combing through the material using microscopy, industrial materials analysis and AI-assisted imaging.

However, if such a sample does not yield any results, this would not necessarily disprove the researchers' hypothesis and may instead mean their models are off and a greater sample size would be required, the team wrote.

"Eminently reasonable"

Several upcoming space missions will collect fresh samples from the lunar surface, including China's recently delayed Chang'e-7 mission and future missions in NASA's Artemis program. These samples could potentially hold technosignatures, although the volume of regolith collected will be far less than what the researchers are proposing.

Therefore, we may have to wait until humans establish a permanent moon base before astronauts can collect enough material to be analyzed properly. This may not be that far off, as both the U.S. and China are planning to construct lunar bases within the next decade. Researchers also think the samples could be analyzed on the moon rather than on Earth.

As a result, the SETI Institute, which leads the international hunt for technosignatures, views the new idea as very promising.

"The concept of searching the lunar regolith for microscopic technosignatures is at once extraordinarily original and eminently reasonable," Bill Diamond, president and CEO of the SETI Institute, who was not involved in the new study, said in the statement. "This is a novel addition to the search methodologies applied to seeking evidence of technology as a proxy for life and intelligence beyond our solar system and we are excited at the prospect of bringing this to fruition."

Extraterrestrials quiz: Are you an alien expert, or has your brain been abducted?

The CL Companion is Swarovski's dedicated compact binocular, originally introduced 15 years ago, but has now been redesigned in 2026 to appeal to a wider, younger audience. RSPB research found an increase of around 1,000% in birdwatching among Gen Z in the UK since 2018, with a similar boom now happening in the US.

The CL Companion sits between the pocket-size CL Pocket and full-size EL and NL ranges, making it the perfect mid-range model that combines portability with excellent optical prowess.

The Companion is a grab-and-go, "take it anywhere and everywhere" binocular that is perfect for many different activities, whether that's spotting birds, scoping out your hiking trail or sweeping across the starry sky at night.

We spent a week with both the 8x30 and 10x30 CL Companions to test them out, with the former being ideal for tracking movement with a wider field of view, while the latter brings you closer to the details.

Swarovski CL Companion: Design

• Simple, fuss-free design
• Rubber grip ensures a secure hold
• Choice of three earth-tone colors

The biggest change in comparison to the old-style CL Companion is in the design. The original version was more of a traditional binocular aesthetic, but this updated design breathes life into the range with three new earth-toned colorways: mountain green, desert orange and safari brown. While some users have said they look somewhat toyish (or just downright ugly), when you handle them in person, they are much more sleek and stylish than the product images would have you believe.

Both the 8x30 and 10x30 weigh just 1.21 pounds (550 grams), so you can easily wear them around your neck all day without even knowing they're there. They're compact enough to put in a large jacket pocket, or you can just wear the included carry bag.

The central focus wheel has just the right amount of slip to make it easy to change focus, but is not so loose that you don't have enough control over it. The diopter is located on the front of the focus wheel, which felt a little off at first, but once we set it, there was no danger of accidentally changing it.

They also have generous eye relief, which is great news for users who wear glasses. The eye relief is 19mm on the 8x30 and 18mm on the 10x30. We used them on a bright, sunny day during a heatwave and were easily able to observe while wearing sunglasses with no issues at all.

Swarovski CL Companion: Performance

• Sharp optics throughout the image circle
• Minimal defects
• Excellent for daytime birding

Out in the field, the CL Companions proved to be particularly well suited to daytime birding — although with 90% light transmission, they'll still hold their own at dawn or dusk. Both the 8x30 and 10x30 had a clear, sharp image, with plenty of detail across the image circle. The 8x30 felt particularly easy to use when trying to pick up birds quickly, while the 10x30's extra magnification was great for getting a closer look at more distant subjects.

The color reproduction was natural, and the views had good contrast without looking over-processed. Fine details on feathers were easy to pick out, even on smaller birds. There was a tiny sliver of color fringing towards the edges in high-contrast situations, but it didn't spoil the view whatsoever, and you'd only notice it if you were actively looking for it (which we were). Every time we have used a pair of Swarovski binoculars, there's a three-dimensional viewing experience and depth to the image that you just don't get with cheaper brands.

Both models performed well in the bright daylight conditions we were using them in, both in terms of optical clarity and comfort when using them for longer periods. Their small size and light weight meant we could comfortably track birds in flight without having to take breaks, which is often a dealbreaker when it comes to choosing a pair of birding binoculars.

Swarovski CL Companion: Functionality

• Wide field of view for birding
• Waterproof down to 13 ft/4 m
• 3m close focusing distance

The wide field of view is one of the more useful features for birding. The 8x30 has a 549 ft (140m) FOV, while the 10x30 has 377 ft (115m) — both of which are wider than the original generation of CL Companion. Both made it easy to find birds when scanning trees and bushes, and there was enough space around the subject to follow them easily after they took flight.

The close focusing distance of 9.8 feet (3m) was also handy when birds came closer, and enables you to observe insects like bees and butterflies without spooking them by getting too close. And with the smooth focus wheel, it was easy to change focus between the two distances.

Both models are waterproof down to 13 feet (4 m), which is likely more protection than most people will need, but it is reassuring when using them outdoors in the rain, or if you were to accidentally drop them in a puddle.

Should you buy the Swarovski CL Companion?

On paper, they tick all the boxes. The optics are excellent, and they're lightweight and easy to carry. But with Swarovski being very upfront about the fact that it’s going after a younger audience with these CL Companions, we have to wonder what young person would have a spare $1,500 to spend on a pair of binoculars? It's not a small investment, so you'd need to be a dedicated observer to spend that kind of money.

That said, they're much more than your typical compact binoculars. They're a genuinely impressive binocular with stunning optics built into a small and compact package. Typically you need to compromise on one or the other, but the CL Companion gives you the best of both worlds.

If this product isn't for you

The brain undergoes dramatic changes during puberty and pregnancy, but during menopause, the organ's structure remains remarkably stable, a new study suggests.

The research, published Sept. 8 in the journal Nature Communications, examined the brain's gray matter, which mostly includes the wrinkled outer surface of the organ, called the cerebral cortex. Past studies have found that the volume of gray matter shrinks markedly during puberty and pregnancy, likely reflecting a fine-tuning of neural circuits during those periods.

There's also a gradual decline in gray matter during adulthood that's seen as a normal part of aging, said study co-author Sophie van't Hof, a doctoral student in psychiatry at Amsterdam University Medical Center. However, during the transition leading up to menopause, that gradual loss of gray matter levels off temporarily, the study found.

"This study provides the first direct longitudinal comparison of brain structural changes across all three major female hormonal transitions," said Magdalena Martínez-García, scientific director of maternal health for the Ann S. Bowers Women's Brain Health Initiative, a brain imaging consortium headquartered at the University of California, Santa Barbara.

"I really appreciate the effort that went into finding and curating such an impressive longitudinal dataset of the female brain," Martínez-García, who was not involved in the study, told Live Science in an email.

Declines in puberty and pregnancy

For their analysis, the researchers gathered data from the UK Biobank, a biomedical database that contains information from 500,000 U.K.-based adults. That data includes MRI scans of people's brains, which the team used to study brain changes in menopause.

To look at puberty and pregnancy, the researchers pulled from several brain-scan datasets that had been compiled by Leiden University in the Netherlands.

In all, the study included data from 1,095 brains across the three life stages. They analyzed each participant's brain at two different time points, examining how each person's brain changed over time and how it compared to others' brains.

The youngest cohort included participants who hadn't started menstruating yet, as well as those who'd recently started and those who'd already had periods for an average of 19 months. The pregnancy cohort included 40 who'd had their first pregnancy during the study and 30 who'd had second pregnancies, as well as 40 women who'd never been pregnant, as a point of comparison.

As in previous studies, the researchers observed that both the girls entering puberty and the pregnant women lost gray matter. But scientists don't necessarily see these declines in gray matter at puberty and pregnancy as negative.

It’s a hypothesis, but "we actually see it as something positive," van't Hof said. "We see it as neural fine-tuning."

During puberty, that gray-matter loss is thought to be a normal part of the brain's development into adulthood. Its function in pregnancy is not well understood, van't Hof noted, but the evidence to date doesn't suggest that it contributes to "mommy brain" — the brain fog and forgetfulness some women can experience postpartum.

"I'm not saying that there's no neurobiological basis for this mommy brain, but up until now, we haven't found it," van't Hof said. "But what's really important is that gray matter decline is not equal to cognitive complaints."

Stability in menopause

The analysis included 120 women who entered menopause during the study. At the first time point, these women had not gone a full year without a period, but by the second time point about 3.5 years later, they had. Menopause is defined as the point at which a full year has elapsed since a person's final period.

The researchers compared these women to two other groups: about 50 women (average age 51) who had not had their last period yet and over 670 women (average age 55.5) who had already had their last period.

During late perimenopause — the final stages of the transition to menopause — the brain's gradual decline in gray matter paused, van't Hof said. Then, in postmenopausal women, that gradual decline of gray matter resumed. The exact timing of that pause differed for each woman, but it occurred consistently across the group, van't Hof noted.

The most striking finding was the lessening of the "ongoing age-related decline in brain volume during the transition into and out of menopause, compared with the more stable premenopausal and postmenopausal groups," Martínez-García said. This is an "interesting finding that adds to our understanding of how dynamic the female brain can be across the lifespan."

Factors such as whether participants had taken hormone replacement therapy for menopause and the number of children they had given birth to did not have a measurable impact on the results, the study authors noted.

In general, complaints of brain fog are widespread just before, during and after menopause, van't Hof said. This could be attributed to declining hormone levels and sleep disruptions.

"We have no clue if there's a neurological basis [for that brain fog], because, again, this is the first study to look at it," she said, adding that more studies are still needed to learn more.

"As with any study, there are some limitations to consider, but overall, I think the methods and conclusions are well supported by the data available," Martínez-García said. Both Martiniz-Garcia and van’t Hof said that they hope other researchers build on these findings to deepen scientists’ understanding of female neurobiology at every stage of life.

This article is for informational purposes only and is not meant to offer medical advice.

See how much you know about the most complex organ in the human body with our brain quiz!

The largest hoard of Viking Age silver ever found in Finland — which contains almost 10 pounds (4.5 kilograms) of coins and jewelry — has been unearthed by a metal detectorist about 95 miles (150 kilometers) north of Helsinki.

The hoard had been divided into two deposits and buried in birch-bark containers. Although the coins and jewelry likely date to between A.D. 1000 and 1050, it's unknown exactly when they were buried, Esko Tikkala, an archaeologist at the Lahti Historical Museum who excavated the hoard, told Live Science in an email.

The hoard has not yet been fully cleaned, separated and counted yet, but there are thousands of pieces, Tikkala said. "There are quite a lot of coins in this hoard," he said. "I have not had time to go through them."

Metal detectorist Kalle Lappinen found the two deposits Sept. 3 and immediately contacted the museum. Archaeologists inspected and properly excavated the finds the next day, according to a translated statement.

Tikkala described the hoard site as beside a rock outcrop in a forest near the town of Sysmä. Several other buried hoards had been found in the same region of Finland over the past 10 years, Tikkala said.

Although it's challenging to determine why specific hoards were buried, a recent study of more than 15,000 Roman-era (the eighth century B.C. to the fifth century A.D.) hoards found that they were hidden for multiple reasons, including for tax evasion, votive offerings, and safe storage in times of uncertainty.

Tikkala said the two deposits of the silver hoard were buried between two stones about 18 inches (45 centimeters) below ground and about 39 feet (12 meters) apart. There were no signs of any burials nearby, but the surrounding area had not been properly studied, he said.

Tikkala added that the coins came from areas that corresponded to present-day Germany, Sweden and Great Britain. There were also some dirhams —‬ silver coins made in the Islamic world. Dirhams previously found in Finland generally date to between about 800 and 1050, he said.

The hoard also contains several pieces of jewelry, including a silver bracelet, and "payment silver" in the form of hack silver (also called hacksilber) — pieces of silver that could be cut into smaller pieces for payments according to their weight.

The weight of the precious metal alone would make the hoard worth almost $10,000 today.

From the Viking Age, but not from Vikings

Although the hoard is from the Viking Age (traditionally, from the 793 attack on Lindisfarne until the 1066 defeat of a Viking army at Stamford Bridge in England), that doesn't mean it was buried by Vikings, Tikkala said.

"The term Viking Age does not imply that there were Vikings in Finland," he said. "We have no sources suggesting that Finland was 'Viking' in the same sense as regions of present-day Sweden, Norway, and Denmark."

Instead, Finnish historians and archaeologists had adopted the term to designate the period, he said. But the area now known as Finland was not culturally or politically part of Viking Scandinavia.

The next stage of the archaeological investigation will be to properly study the site where the two deposits were found, as well as their surroundings, Tikkala said; after that, specialists in Viking Age coins will try to identify the coins and prepare a detailed report.

"There will definitely be scientific articles published on the hoard as a whole, as well as more detailed studies of the coins themselves," he said.

Until now, Finland's largest Viking Age hoard was found in 1895. Buried at Nousiainen, about 130 miles (210 km) southwest of Sysmä, it contained more than 1,700 silver coins but weighed only about half as much as the newfound hoard.

Other Nordic countries have also recently reported their largest Viking Age hoards. A cache of more than 4,700 coins was found in Norway this past spring, and a homeowner in Denmark unexpectedly discovered a hoard of more than 700 silver objects weighing more than 40 pounds (18.5 kg) in their backyard, also in the spring.

See how much you know about ancient norsemen with our Viking quiz!

Many people are familiar with melatonin, a hormone that helps ready the body for sleep. But there's another, lesser-known chemical in the brain, called orexin, that tips the scale in the other direction: waking the body up.

In 1999, two scientists independently uncovered the function of orexin and published papers about it. Dr. Masashi Yanagisawa, a molecular biologist and physician now at the University of Tsukuba in Japan, came across orexin while studying the interaction of receptors and chemicals in the brain. Dr. Emmanuel Mignot, now the director of the Stanford Center for Narcolepsy, homed in on orexin while studying narcoleptic dogs. (His Chihuahua, named Watson, has narcolepsy, and he previously had another dog with the condition, named Bear.)

This year, the pair of researchers won the coveted Albert Lasker Basic Medical Research Award for this fundamental finding that helped reshape our understanding of sleep. Their work has since led to the development of drugs for insomnia and narcolepsy.

Yanagisawa told Live Science that, at the start of his research career, he didn't expect to end up studying sleep. Mignot, on the other hand, had an early interest in understanding narcolepsy so that better treatments for the neurological disorder could be developed. Live Science spoke with Mignot about the discovery of orexin and how the field might progress in the future.

Nicoletta Lanese: What initially drew you to studying narcolepsy?

Dr. Emmanuel Mignot: There were three things that attracted me to narcolepsy: Number one, it was a human problem. It was already known [at the time] that it was not super rare. I'm not saying it's super common, but 1 person per 3,000, 0.03% ‪—‬ it's reasonably common. And nobody cared about it. I would talk to neurologists and they'd say, "Oh, I've never seen one case in my entire life." So I would say, "Yes, of course; you miss them all." That was the state of the play at the time.

Number two, was what this was a quintessential sleep disorder [in which sleep itself is disrupted]. I thought that if we found the cause of this disease, we could potentially discover something totally new about sleep — a fantastic entry point to a mystery.

The third thing that made me ready to go there was that it was tractable. A lot of problems are not tractable.

NL: Why did you start working with the dogs with narcolepsy?

EM: I studied the pharmacological basis because I was trained in pharmacology, and as a psychiatrist, and I discovered how this drug modafinil [a stimulant-based narcolepsy treatment] was working. But quickly, I realized I'm not going to find the cause by doing pharmacology. I'm only going to explore what's known.

That's when I started to fall in love with genetics, even though I was not trained as a geneticist. I said, "We have to find this gene in the dogs." It looks like they have all the symptoms. It was a huge bet, and it took me 10 years because I was definitely … overoptimistic. But it was worth the price at the end.

NL: And scientists already knew about narcolepsy in dogs at that time?

EM: The guy at Stanford that started the sleep program was called Dr. [William] Dement. He was a graduate student in Chicago in the 1950s, when [Eugene] Aserinsky and [Nathaniel] Kleitman discovered REM sleep. He had the foresight to understand that this was an important discovery.

[Later], he discovered that narcolepsy was really a disorder where people go into REM sleep and have this very abnormal dreaming. He came in 1970 to Stanford, and the first thing he did after his medical school was to start a clinic to see patients with narcolepsy. Around then, he spoke at an American Medical Association conference in San Francisco, and he discussed different sleep disorders, including narcolepsy. And then there was someone in the audience that said, "Oh my god; I have a dog with your disease. Every time it gets excited — boom — it collapses. And it sleeps all the time."

That dog had already been euthanized, but it still gave him the idea that these dogs have narcolepsy — maybe we should try to get some. So he went to a lot of veterinarians to talk to them about it, and they identified a whole series of dogs, including the first poodle, Monique, who had narcolepsy. And they started this little colony of dogs. Initially, they tried to breed them, but most cases of narcolepsy are actually not genetic. Then, in 1977, they got a whole litter of Dobermans, and then Labradors, that had some form that was genetic.

So when I arrived, it was in 1987. They already had the dog colony. I came to study the pharmacology, to try to find a better treatment for narcolepsy. But I did stand on the shoulders of giants.

NL: At that time, it's not like you had a complete dog genome. Did that make studying their genetics challenging?

EM: It was crazy. A couple of human genes had been isolated, and mouse genes, but it was a handful. We didn't even have the full genome map in humans. And meanwhile, dogs — no pun intended — were in no man's land. Very little was known.

It took me 10 years. I had times where some people didn't believe that the dogs had narcolepsy. There were a few depressing moments, but I was convinced that was the right thing to do.

NL: When you ultimately found the receptor for orexin, did it surprise you? It strikes me as surprising that there would be a discrete "switch" in the brain that controls wakefulness.

EM: I was lucky. Honestly, I had no idea. I got enamored with genetics because what I love [about it] is you can find something without any hypothesis. You just search for it, and what you find tells you what it is. You have no prerequisite for knowing what you would find.

I could have found something much less significant. That was a dream, to find a GPCR [G-protein coupled receptor, a protein on the outside of cells]. Can you imagine? A drug target.

Then, it turned out to be immediately applicable to humans. That, too, was a lot of luck; let's be honest. I was just trying to find the cause of one thing and one step at a time; it could have been something very complicated. It turned out to be simple.

Was I surprised? No, because I was not expecting one or another.

NL: Do you recall what the reception was like when the initial finding was published?

EM: It had an immediate effect, for several reasons. For example, I was seeing a lot of patients with narcolepsy at the time, but they were all old folks that had had narcolepsy forever. A lot of people would tell me, "I think I had it from when I was born, because I don't remember." We were never seeing children.

But after narcolepsy was described — the dog gene — suddenly narcolepsy became much more famous. And what happened is that people started to pay attention to narcolepsy, and we started to see kids. In kids, the picture is so much different. They gain an enormous amount of weight; it's very abrupt. It's a little bit different than what you see in adults, where they have adapted to it.

That was, I think, a practical consequence of the discovery. It really put narcolepsy on the map.

The second thing that happened is, all the drug companies started to develop hypnotics [sleeping pills], trying to block the orexin. They developed hypnotics relatively quickly, and they are very effective. They are probably safer than benzos [benzodiazepines] and so forth.

NL: Is it considered safer because the orexin blockers better replicate natural sleep?

EM: We know that the orexin definitely drops during sleep, so blocking it is definitely a way to recapitulate that drop; that's true. It's an awake-promoting system, so if you remove something that makes you more awake, it's safer than inducing sleep by shutting down the brain.

NL: As you moved to studying narcolepsy in humans, you found evidence that there might be an autoimmune response involved; it's been suggested that such a response may be harming the cells that make orexin in the brain. Was there suspicion that the condition had an autoimmune element previously?

EM: It's not something I 100% discovered. In 1983, before I came to study narcolepsy, there was a guy in Japan who I met, called Yutaka Honda. [Editor's note: Honda's research linked narcolepsy to the human leukocyte antigen (HLA) region of the genome, which helps regulate immune responses.]

The HLA is the way the immune system sees the world. That had just been discovered as very important for transplantation, because it's very polymorphic [takes on different forms] from one person to the next. They [Honda's group] found that all narcoleptics had a particular genetic variant, called HLA-DR2. This was a total surprise.

When I came, that was already known. But then people really looked and tried to see if the disease was autoimmune, but they couldn't find anything — no autoantibody, nothing. It was all negative.

I did a study with African Americans, and in African Americans, I found that this DR2 marker was not the best marker for narcolepsy. It was a gene just next to it that was called DQB1*06:02. [Editor's note: That HLA variant is now recognized as a strong risk factor for narcolepsy, particularly for narcolepsy type 1 (which involves a symptom called cataplexy).]

I'm very proud of that study because I think it's the first time that people used human diversity to actually map down a genetic factor more precisely, which now is used commonly. It's called transethnic mapping.

NL: New treatments that target orexin have just been approved. Do you see those therapies as an extension of your earlier findings?

EM: Of course. I was trained as a pharmacologist originally, so obviously, I do a lot of clinical trials. I see my patients totally transformed by this medication. It's just amazing. I'm so fortunate. How could you get a better reward than seeing your patients totally transformed by this medication?

It's going to have a lot of other applications [beyond narcolepsy]. Some people think it's going to be very helpful for ADHD; some people think it could be very helpful for depressed people with excessive sleepiness. We don't know, really; there's a lot of possibilities.

Another thing I'm excited about is that I have a few patients with [both] narcolepsy and schizophrenia. You cannot give them stimulants. If you give them modafinil or another dopamine stimulant [for narcolepsy], they have even more hallucinations. Often, they are sedated by their medication, and we are very poor at making people more motivated and active. These [orexin-activating] drugs seem to have effects beyond just waking people up. They seem to increase motivation.

You don't know until you try, but I'm sure it's going to have other applications.

This interview has been condensed and edited lightly for clarity. It is for informational purposes only and is not meant to offer medical advice.

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To the untrained eye, Xiaoyu Shan's lab bench looked like a home gardening experiment gone bad: dishes filled with dirt — some that looked like mud pies and others that were bone-dry — and not a plant to be seen.

But those dishes held a warning. The dirt that Shan, a postdoctoral research associate in biology and biological engineering at Caltech, was studying contained soil microbes. And those soil microbes were exhibiting a concerning propensity: In dried-out soil, they were evolving to become more antibiotic resistant.

The study describing those findings, published in March, systematically showed that drought conditions could fuel the evolution of antibiotic-resistant bacteria. Most of this resistance is driven by humans' misuse of antibiotics, which spurs bacteria to evolve genes that help them ward off the drugs. But the Caltech study raised a new worry: As many places face increased drought conditions, climate change itself could act as a selective pressure that could supercharge the evolution of these drug-resistant superbugs.

"We can expect to have more resistant bacteria being selected for in certain places around the globe," said Dianne Newman, a Caltech microbiologist and co-author of the study.

Increased antibiotic resistance is just one way that climate change is likely to put new populations at risk of multiple types of infections.

And this increased disease burden will coincide with climate change scrambling supply chains, eroding nutrition and stressing our health in other ways.

"No individual metric really does justice to the overall risk and health and well-being of these multiple stressors being exacerbated all at once and compounding each other," said Marina Romanello, a principal research fellow at the Institute of Global Health at University College London.

Warm-weather disease

In the small mountain town of Bailey, Colorado, which lies at an elevation of 7,740 feet (2,360 meters), May often brings snowstorms that can blanket the ground in white even as the sun starts to bake the plains at lower elevations. But on Memorial Day 2026, the forest floor was dry and ticks quested their way along blades of grass, seeking a blood meal.

A mild winter in most of the country means ticks — and the diseases they carry — are a rising concern. In April, the Centers for Disease Control and Prevention (CDC) reported that emergency department visits for tick bites were at their highest for that month since 2017. That trend isn't a one-off, according to the CDC; as temperatures rise, insects and arthropods can survive longer in the year and farther north.

As a result, vector-borne illnesses such as Lyme disease (spread by black-legged ticks in the Ixodes genus) and West Nile virus (spread by mosquitoes) will become more common in increasingly northerly locations. Already, alpha-gal syndrome, which is not an infection but is transmitted by the Lone Star tick (Amblyomma americanum) and causes an incurable allergy to red meat, is also seeing a dramatic rise as the species expands its range across the Northeast. Positive tests for antibodies to the alpha-gal molecule have increased by 100 times between 2013 and 2024.

Right now, almost half a million people are treated for Lyme disease each year, and the CDC records more than 8,000 cases of other tick-borne diseases annually across the country. It's not clear how this will change as the climate warms. One 2022 study found major increases in Lyme disease only at levels of warming of 6.3 to 9.9 degrees Fahrenheit (3.5 to 5.5 degrees Celsius) by 2100, but that much warming that fast is now considered an implausible scenario. However, the researchers saw a huge amount of uncertainty in the numbers, given the number of variables that affect whether a spreading tick population will transmit more disease, such as how often people go outside or what steps they take to avoid tick bites. Tick-borne illnesses are likely also underreported, so even the true number of illnesses transmitted each year right now is unknown.

But ticks are responsible for spreading 90% of all vector-borne diseases in the U.S., so any trends in the suite of illnesses spread by ticks are likely to affect thousands to tens of thousands of people.

An even more ubiquitous bloodsucker, the mosquito, currently spreads only a few diseases in the U.S. The most common and most serious is West Nile virus, which mosquitoes catch from feeding on infected birds. As of Sept. 8, 504 cases of West Nile virus had been reported in the U.S. in 2026, with 363 of them affecting the central nervous system. And because fewer than 1% of West Nile cases progress to the central nervous system, those numbers likely represent a dramatic underreporting of milder cases, which can cause months of fatigue in some people, in addition to acute flu-like symptoms, such as fever, headache and body aches.

Mosquito-borne illnesses like West Nile are expected to spread more quickly in warming temperatures. Heat helps mosquitoes stick around longer during the year, much like it does for ticks. It also speeds up the transmission and replication of the virus inside the mosquito, since the insects are cold-blooded and thus their metabolism is ruled by the weather.

"Except for places that are already really, really warm, we should expect that the replication rate of the virus inside the mosquito will speed up," said John Drake, director of the Center for the Ecology of Infectious Diseases at the University of Georgia. "That shortens the generation time, and that means we expect there to be more transmission."

Even though mosquitos love water, climate-related drought could ironically nearly triple the number of human West Nile cases in the U.S. over the next 30 years from around 2,000 reported cases (according to CDC data) to between 5,000 and 6,000. That's likely because in drier conditions, more mosquitoes are infected, possibly because birds, the intermediate host of the virus, either congregate more closely with mosquitoes around water sources or breed less readily in drought, meaning the fraction of birds that carry the virus is higher than in more water-abundant times.

Mosquito-borne diseases long ago eradicated from the U.S. could also resurge with warming temperatures. The southeastern United States will become more prone to malaria and dengue fever transmission under all levels of warming; summer 2026 saw more than 40 locally-acquired cases of dengue fever in Florida. Public health surveillance and disease-control measures have largely stopped those transmission chains, but the likelihood is that society will have to pour more money into beating these diseases back again in future decades. For example, there are malaria vaccines approved for children, but currently, they are recommended only in areas where the illnesses are endemic. If malaria were commonly found in the southern U.S., millions of Americans might need vaccines, including susceptible adults.

"If we were to get endemic diseases like those in the U.S. again, it could become a huge burden and it could be quite costly," Drake said.

Disaster and disease

Flooding is another factor that's exacerbating vector-borne disease under climate change. As climate change worsens, extreme weather events will, too. Because warm air can hold more moisture, many areas will see increased episodes of heavy rainfall and hurricanes will become more intense.

"Flooding creates habitat for these mosquitoes," Drake said.

Disasters also spur the spread of other diseases that are usually quite rare in the U.S., such as leptospirosis, a bacterial infection that spreads from animals to humans via animal urine. Floodwaters may be contaminated by the bodies of drowned animals; in 2022, after Hurricane Fiora hit Puerto Rico, leptospirosis cases leapt by a factor of 3.6 to over 10 cases a week.

After Hurricanes Matthew and Florence in 2016 and 2018, respectively, North Carolina saw an 11% increase in emergency department visits for gastrointestinal illnesses. Black and American Indian residents were the most affected, likely because discrimination over generations has disproportionately pushed Black Americans and Native Americans to less desirable, more flood-prone land, the researchers found.

Cycles of precipitation, drought and subsequent dust storms can spur the spread of Valley fever, a fungal respiratory disease that causes an estimated 700 to 1,100 deaths per year, mostly in the U.S. Southwest. Valley fever is already on the rise, with cases in Arizona, one of the hotspots for the disease, doubling from about 64 cases per 100,000 people in 2005 to 145 cases per 100,000 people in 2022. As the West warms and dries, Valley fever is likely to spread from its stronghold in the Southwest and become endemic in Idaho, Wyoming, Montana, Nebraska, South Dakota and North Dakota, putting millions more people at risk.

The infectious disease risk from natural disasters tends to stack on top of other health problems stemming from these catastrophes. Flooded buildings can harbor mold that can worsen allergies, asthma and other respiratory illnesses. When major storms cause power loss, people turn to generators for electricity, which release pollutants linked to asthma. Though it's often hard to track the effects of these disasters, one study found that flooded regions after Tropical Storm Imelda in Texas in 2019 saw 10% more emergency department visits for asthma than nonflooded regions did.

Moreover, the threat to life and livelihood from these disasters can cause mental health conditions, such as post-traumatic stress disorder, Romanello said. The problems compound on each other, she said; already, she has heard reports from Africa about malaria outbreaks, fed by warming, and health workers struggling to reach the affected regions because flooding, also exacerbated by warming, has washed out roads.

"What is the most concerning aspect is that all of that is happening together, so we're seeing all of this risk being exacerbated at once," she said.

Antibiotic resistance on the rise

As Newman and Shan's work shows, as spots around the U.S. face new infection risks, existing treatments may become less effective. Their work showed that drought concentrated the natural antibiotics that bacteria make in the soil, making it harder for bacteria susceptible to the compounds to survive. As a result, the microbes with genes for antibiotic resistance did better. The problem for human health is that bacteria are very good at gene swapping, so these soil microbes can easily pass their antibiotic resistance superpowers to bacteria that infect people, their research showed.

"Gardening, breathing dust ‪—‬ that's how it happens," Newman said of human and soil bacteria coming into contact. "We are constantly encountering bacteria in our environment."

The researchers found an association between drought and antibiotic resistance reported by hospitals.

They aren't the only ones. A recent study on Salmonella, a bacterium that causes about 1.35 million cases of food poisoning each year in the U.S. alone, found that temperature and rainfall promote antibiotic resistance in this microbe. "Globally, climate change was linked to about a 10% increase in Salmonella resistance gene abundance," said study first author Zhen-Chao Zhou, an ecology researcher at the Chinese Academy of Sciences in Beijing. Other microbes show similar effects.

Meanwhile, warmer conditions help bacteria grow faster, adapt to stress and swap resistance genes, Zhou said, while drought concentrates them in limited water sources where they mingle freely. Climate-change-induced flooding can then, in theory, spread the resistant genes far and wide.

Combating the compounding risks requires both public health and climate mitigation approaches, experts say. Not only does the world need to cut greenhouse gas emissions, but people also need to use antibiotics more carefully, Zhou said; improve sanitation practices, such as sewage management, around the world so that antibiotic-resistant strains don't spread as easily; strengthen food safety; and expand disease surveillance. The public also needs to understand that climate change is a health issue, Romanello said.

"When we talk about tackling greenhouse gas emissions," she said, "what we're talking about is a sustainable livable future with healthy economies."

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A family photo album can reflect how physical traits, such as blue eyes or lanky limbs, have been passed down — but a new analysis suggests that the way personality emerges across generations is far more complicated.

The meta-analysis, published Sept. 2 in the journal Nature, is the largest of its kind ever attempted. The work identified over 1,200 genes linked to five personality traits: extraversion, agreeableness, conscientiousness, openness to experience and neuroticism.

However, the scientists behind the study said its most important conclusion is that no single gene determines whether an individual will have a particular personality trait. Instead, thousands of genes exert tiny effects that are likely impossible to disentangle from environmental factors that shape our behavior.

Twins and DNA sequencers

Researchers have studied the link between genes and behavior for decades. Before the ability to analyze the genome in detail, many early studies looked to identical twins.

Knowing that identical twins share nearly 100% of their genetic material, scientists compared their traits with those of nonidentical twins and other siblings. Some studies compared twins raised in the same home with those raised in different homes in an attempt to separate the influence of upbringing from genetics. These efforts concluded that personality was roughly 50% heritable. ("Heritability" measures how much of the variance seen in a given trait can be explained by genes.)

The advent of gene sequencing enabled geneticists to calculate the influence of genes with greater precision than twin studies did. The most powerful tool in this arsenal is the genome-wide association study (GWAS), which can link traits to gene variants in detail. These statistical analyses require sample sizes in the millions, though.

The new study was a large collaborative project called the Revived Genomics of Personality Consortium, which brought together 46 cohorts of participants who'd had their genomes sequenced. Each person had been asked something related to one of the Big Five personality traits. The team had data from roughly 600,000 people about the first four traits — extraversion, agreeableness, conscientiousness, openness to experiences — and data from over 1.1 million people about their levels of neuroticism.

Generally, as geneticists have leveraged larger and more powerful GWAS, many traits have shown increased heritability because these bigger studies can identify more subtle genetic links, said Brent Roberts, a psychologist at the University of Illinois at Urbana-Champaign who was not involved in the new study. But "with personality, it was really clear from the get-go that it was different," Roberts said.

Earlier GWAS had suggested that the heritability of personality from common gene variants was roughly 5% to 15%, far lower than the estimate suggested by twin studies. The new work has confirmed those low numbers, said study co-author Michel Nivard, a genetic epidemiologist at the University of Bristol in the U.K.

It may be that GWAS do not capture extremely rare variants that might link personality traits in certain families, which means the heritability may be slightly underestimated, Nivard suggested. Additionally, twins are more likely to rate their personalities as similar for reasons unrelated to genetics, so the twin studies may have overestimated the heritability of personality, Nivard noted.

Cutting out confounders

It can be difficult to control for confounding factors in GWAS. For example, if scientists were investigating the influence of genes on academic achievement, genetics only tells part of the story; a person's socioeconomic status and access to books and tutoring also influence their education.

But in this case, Nivard and his colleagues did not find confounders in measuring personality. The researchers found that the genetic effects on personality are the same within families as they are among unrelated individuals.

"We've basically been able to rule out that there's any straightforward, simple social processes by which your parents directly influence your personality," Nivard said.

A key takeaway from the study should be not to focus too much on the different contributions of genes versus environmental factors in a trait as complex as personality, Roberts said. Our moods and minds are a collaboration between the two factors, not a tug-of-war, he argued.

A study to properly measure this interplay would be vastly expensive and would require following participants for decades. "This is where the limitation of human genetics research is really profound," Roberts said. Part of the problem, he added, is that while our DNA sequence is fixed, how the body accesses and reads DNA varies significantly depending on the environment a person finds themselves in. In other words, which genes get turned on and when are variable factors.

Assessing this enmeshed relationship using only the DNA code we are born with is like trying to predict every move of a couple's dance by looking at how they hold each other before the music starts up.

Nivard and his team can now use this powerful data source to learn more about personalities within groups of people, he said. Nivard predicted that, even once geneticists have mapped all the rare gene variants that may influence personality, some genetic influence will still go unaccounted for; processes such as the interaction between the environment and gene expression are still not fully understood. He called these the "unknown unknowns." Identifying these factors is the next frontier for the genetics of personality.

"It's where we're headed," Nivard said.

Mercury, which is about one-third the size of Earth, may have shrunk more in its evolution than scientists originally thought.

A new study suggests that the tiny planet may have contracted 10% to 30% more than previous models suggested — meaning the planet’s total diameter shrunk almost 12 miles (19 km) since Mercury was formed. (Mercury’s diameter today is roughly 3,032 miles (4,880 km).

Previous missions overlooked the extent of the shrinkage because impact-crater debris on Mercury's surface hid the evidence, according to a study published Thursday (Sept. 10) in the journal Geophysical Research Letters. That size difference is important when researchers consider the planet's history, said Gaku Nishiyama, a planetary scientist at the German Aerospace Center Institute of Space Research and an author of the study.

"Because Mercury's evolution is driven by its cooling, the amount of contraction — an indicator of the extent of cooling — is one of the most important observables that can be compared to models for estimating its evolution scenario," Nishiyama told Live Science in an email.

There could also be implications for the planet's composition. For example, more shrinkage at Mercury could mean the planet would have a larger metal core and fewer light elements, such as silicon, inside that core, according to an American Geophysical Union statement.

"The interior of Mercury would reflect its formation," Nishiyama said, and possibly hint at the innermost part of our solar system. "Therefore, to understand how our solar system has evolved up to now, information that can be extracted from this estimation — such as core composition and initial temperature condition — is critical."

A violent history

Mercury and the rest of the solar system planets formed due to the gradual collisions and aggregations of rock and gas upon asteroids and comets. Some of those impacts that created the planets also released a lot of heat. Mercury has been slowly cooling from those ancient impacts, and its interior has been shrinking along the way.

While this kind of cooling affects the entire planet's landscape, impact craters can mask the effects because each crash into the surface generates its own surface changes, including debris and new divots. The craters build up over time, making it difficult to spot more ancient geology underneath.

Nishiyama's team compared two sets of maps from Mercury, using data from NASA's MESSENGER mission, which orbited Mercury between 2011 and 2015. One set of maps charted geological features showing contraction, and the other set estimated the roughness of the planet's surface. Their work covered the entire surface and demonstrated that the most rugged spots on the planet have fewer wrinkles from shrinking. In other words, according to Nishiyama, the debris from more recent impacts is covering up the evidence of shrinking.

Nishiyama said more information will help to confirm the estimate. Such data could come from the European Space Agency's BepiColombo spacecraft, which began its arrival sequence at Mercury earlier this month after nearly eight years of space travel. Once the mission settles in, the spacecraft will take higher-resolution imagery of the surface than MESSENGER did. Nishiyama's team expects BepiColombo to pick up smaller impact craters, as well as scarps and ridges, that could further refine the measurements.

"Stay tuned for future topography measurements by BepiColombo," Nishiyama said. "Future data from laser altimetry on BepiColombo will collect more information on planetary contraction by measuring topography more precisely."

IBM and NASA have partnered to create a new artificial intelligence (AI) model capable of processing decades of lunar data so scientists can more accurately map the moon's surface one day.

Decades of robotic lunar missions have left scientists with a massive, disjointed trove of data. Traditionally, this data has been parsed by limited transformer models such as SwinV2-B, created in 2022 as a general-purpose model to understand images and improve accuracy on photo recognition and related vision tasks. Spacecraft orbiting the moon captured this data using a mismatched array of sensors, without an accessible way to analyze or utilize it.

Specifically, images from high-resolution optical cameras, laser altimeters, radar reflectance tools and spectrometers that measure elemental density have created huge datasets — but unifying them into a cohesive picture of the lunar surface has been a labor-intensive and computationally demanding process.

To crack the data bottleneck, researchers from NASA and IBM teamed up to build the Lunar Foundation Model (LFM). This agile AI system is designed to piece together multimodal, multiresolution data to build a detailed picture of the lunar surface to support future missions. The team published their findings Sept. 10 in a technical paper shared with Live Science.

The scientists wanted to build a single, reusable backbone AI model that would be freely available to scientists via the open-source AI model repository Hugging Face. Because the model is open-source, researchers could fine-tune the AI to tackle specific questions as part of different projects.

For NASA, this includes thorny issues such as generating a reliable crater map so researchers can plot safe landing zones, or analyzing those craters for clues about the chemical makeup of the moon's interior and its history.

LFM also enables scientists to comb through the data for heavily shadowed sites on the moon that often conceal subsurface ice, which is critical for establishing long-term lunar bases. Volcanic activity can be tracked and collated too, which will allow future projects to avoid unstable terrain and reveal insight into the moon's thermal evolution.

Unique challenges

Processing lunar observations presents unique computational challenges that differ from those of similar models, which cover things like weather, geospatial data and heliophysics. NASA's Lunar Reconnaissance Orbiter and other spacecraft collect measurements across vastly different spatial scales, ranging from broad regional maps at a resolution of 100 meters per pixel down to terrain scans resolving at 1 m per pixel.

Because the moon lacks an atmosphere, extreme sunlight geometry is an issue, creating deep, deceptive shadows. Sunlight can also wash out subtle geological details, depending on when an image was captured.

To overcome these problems, the team compiled a layered benchmark dataset named SomBench, made up of nearly 2 million overlapping map patches called tiles. SomBench organizes that data into aligned tracks so data from completely different instruments, or imagery taken at different resolutions or angles, all end up together as long as they're capturing the same tiles.

The lower-resolution layers provide wide-angle overviews, as well as ultraviolet reflectance and elevation data. High-res layers combine tight, detailed camera shots with meter-scale terrain, slope and orientation maps. Specialized readings of thermal behavior, surface mineralogy and local gravitational anomalies also get layered in.

LFM learns to interpret all that layered data through a technique called masked-token learning, which is where parts of a dataset are hidden so the AI has to fill in the blanks. During training, the AI is shown a portion of a lunar tile, like its visible light appearance and elevation, and nothing else. The model then continuously predicts the concealed information across millions of examples, and learns the relationships between elements like lighting, terrain structure and physical geography.

Lighting analysis is built directly into the model's core architecture. Rather than forcing the model to infer light levels solely from shadows, researchers supplied explicit metadata describing solar angles and spacecraft positions. This allows the model to use its processing power to recognize actual terrain features rather than getting tricked by shadows.

One giant leap

The AI model performed well across four tasks it was evaluated on. In crater detection, it outperformed SwinV2-B by nearly 19% using half as many training labels. When estimating polar ice prospectivity within the top meter of regolith (lunar dust and rocks), LFM maintained strong predictive power with fewer data channels and reduced errors in identifying areas with high potential for lunar ice by up to 22% compared with SwinV2-B. Its performance on meter-scale crater mapping and rare volcanic landforms was similarly competitive with top custom models.

Scientists can customize LFM using lightweight techniques like low-rank adaptation — a way to fine-tune an AI by changing a tiny set of weights and not touching most of the original model. This allows researchers to tailor the model to specialized exploration tasks, without the steep computing costs of training an AI from scratch.

However, the researchers cautioned in a statement that the system best serves as a pattern-recognition assistant and is not a replacement for direct physical measurements. Nonetheless, the team said the model represents a major leap toward transforming decades of raw data into a unified, intelligent toolkit for future robotic and crewed lunar missions.

In the near term, scientists will likely use the LFM as a backbone for key lunar remote-sensing tasks, while the long process of fine-tuning it ramps up. Over time, the model will be refined for tasks like improved crater detection and mapping, segmenting subtle geomorphic units such as irregular mare (volcanic activity) patches, and improving polar ice detection by integrating terrain, illumination, and thermal layers.

The Canon RF 20mm f/1.4L VCM is an intriguing lens for photographers who want a wide field of view without sacrificing aperture. Its f/1.4 maximum aperture makes it particularly appealing for astrophotography, while the 20mm focal length offers plenty of room for landscapes, architecture and other wide-view scenes.

We took the lens out to the dark skies of Wales to photograph the night sky and the Perseids, giving it a real-world test in some of the best conditions we could find.

With a premium L-series build and a price tag to match, there's a lot to consider before adding this lens to your kit. We wanted to find out how it actually performs in the real world, and whether it's worth the investment.

Canon RF 20mm f/1.4L VCM: Design

• Premium, solid build
• Surprisingly manageable for an f/1.4 lens
• A few small quirks keep it from being flawless

The Canon RF 20mm f/1.4L VCM feels like a proper L-series lens from the moment you pick it up. It's solid and reassuringly well-built, but it never felt excessively heavy or awkward on the camera. At 1.41 pounds (519 grams), it's certainly not a tiny 20mm prime, but the weight is well balanced and it was comfortable to carry and shoot with. And considering it'll often be used for astrophotography, it'll be on a tripod a lot of the time anyway.

The focus and control rings both feel smooth and nicely weighted, while the switches and customizable buttons are easy to find without having to look at the lens. The weather-resistant build is another bonus for outdoor shooting, which will come in handy if you also use the lens for landscapes where you might encounter inclement weather.

The dedicated aperture ring is also a nice feature, especially if you prefer having more physical controls rather than relying on the camera body and remembering which dial is set to each setting. Plus, the clickable nature of the aperture ring is an ASMR dream.

Canon RF 20mm f/1.4L VCM: Performance

• Excellent low-light performance
• Sharp in the center with some corner softness
• f/1.4 makes a real difference under dark skies

A fast 20mm is a pretty exciting combination for astrophotography. It gives us plenty of sky to play with, while the f/1.4 aperture pulls in a lot of light. Under those dark skies, the Milky Way came through beautifully, with plenty of detail without needing to resort to boosting the ISO too high.

We took the lens out to Carmarthenshire in Wales under Bortle 3 skies to photograph the night sky during the peak of the Perseids, which also coincided with the new moon — the perfect recipe for astrophotography.

The center of the frame is where this lens is at its best. Stars are crisp and well-defined, which is exactly what we want from a lens that is being used for astrophotography. The edges aren't quite as impressive, though. There is some softness and a little stretching of the stars towards the outer parts of the frame, particularly when the lens is wide open. It's not enough to ruin an image, but it becomes obvious when zooming in and pixel-peeping at the corners.

Canon RF 20mm f/1.4L VCM: Functionality

• Quick and reliable autofocus performance
• Customizable controls are genuinely useful
• A practical choice for everyday shooting

The Canon RF 20mm f/1.4L VCM is very straightforward to use out in the field — especially in the dark. The autofocus was quick and reliable during testing, and for everyday shooting of landscapes, or even for video, this means there's very little to think about.

The customizable controls are useful, too. The lens function button and control ring can be assigned to different settings, allowing you to put the controls you use most within easy reach. It's a small thing, but being able to set the lens up around your personal shooting style makes it feel more intuitive and can save a surprising amount of time.

The 67mm filter thread is another practical advantage, as it's a common filter size, so you won't necessarily need to invest in an entirely new set of filters if you already own that size.

The lens doesn't feature a ton of bells and whistles, but that's not a bad thing. It's designed to be picked up and used without much fuss, and after spending time with it, we found that its simplicity is one of its strengths.

Should you buy the Canon RF 20mm f/1.4L VCM?

The Canon RF 20mm f/1.4L VCM lens makes the most sense for photographers who regularly work in low light or want a dedicated wide-angle prime. Astrophotographers are likely to get the most from it, but it also has plenty to offer for landscapes, architecture, interiors and environmental photography.

Its biggest appeal over a zoom is its f/1.4 aperture. If you already have a wide-angle zoom but regularly find yourself having to bump up your ISO in low light, this lens fills that gap while also offering the control of a fast prime.

However, it's a fairly specialist addition to a lens lineup, and the price makes it tricky to justify if you only occasionally shoot wide. If you need the flexibility of changing focal lengths, or if you primarily shoot distant subjects, you'd be served better by a zoom or longer lens

If this lens isn't for you

There may be no better month to get outside and look at the stars than September, when warm evenings meet rapidly lengthening nights, the Milky Way remains visible overhead, and the changing seasons can increase your chances of seeing the northern lights.

For stargazers in the Northern Hemisphere, summer presents an obvious problem: Darkness arrives late. By September, however, sunset is getting noticeably earlier each evening, providing far more time under dark skies with mild weather in most locations. Days can still feel summery, while nights tend to remain pleasant enough to spend hours outside with a pair of stargazing binoculars or a good backyard telescope. The only challenge is finding a clear sky.

The balance between daylight and darkness changes particularly quickly around the fall equinox, which occurs on Sept. 22 this year. That's when the sun crosses Earth's equator, bringing day and night close to equal in length around the world. From then on, nights become longer than days across the Northern Hemisphere until the winter solstice on Dec. 21.

As an occasional bonus, auroras tend to occur more frequently around the equinoxes. During this time, the orientation of Earth's magnetic field creates favorable conditions for interactions with the solar wind (the cause of auroras), but there are never any guarantees.

September stargazing highlights

This month, there's plenty happening overhead.

All five planets visible to the naked eye can be seen during September, although not simultaneously; Venus and Mercury are visible in the evening, while Mars and Jupiter come out in the morning. Saturn is visible for much of the night, while Neptune reaches opposition on Sept. 26, meaning it is on the opposite side of Earth as the sun, offering the closest and most direct viewing opportunity.

The moon also passes close to several bright planets during the month (it passed Jupiter before dawn on Sept. 8 and will nudge Venus after dark on Sept. 13 and 14), while the full Harvest Moon rises on Sept. 26, with Saturn following after it minutes later.

September is also one of the last good opportunities of the year for Northern Hemisphere observers to see the brightest parts of the Milky Way in the evening. The star-rich regions of Sagittarius and Scorpius are sinking toward the western horizon, while the iconic Great Square of Pegasus rises in the East to announce the arrival of the autumn sky.

With all those cosmic treats on tap, this month certainly hits the sweet spot for stargazers.

This year's Lasker Awards — coveted prizes for biomedical research that are sometimes called "America's Nobel Prizes" — have gone to scientists behind fundamental discoveries in sleep science and to researchers who developed a groundbreaking treatment for hemophilia.

Additionally, a Lasker Award for public service went to actor Michael J. Fox for his advocacy for patients with Parkinson's disease that has helped advance research into the neurodegenerative condition.

The prizes, each of which comes with an honorarium of $250,000, will be presented in person Sept. 17 in New York City. The awardees were announced Wednesday (Sept. 9) by the Lasker Foundation, which was established in 1942 by the philanthropists and health advocates Albert and Mary Lasker.

A deeper understanding of sleep

The first of the three awards, called the Albert Lasker Basic Medical Research Award, went to two scientists who independently discovered a key substance in the brain that helps control the sleep-wake cycle and is missing in people with some forms of narcolepsy — the neurological disorder marked by excessive daytime sleepiness and, sometimes, cataplexy (sudden episodes of muscle weakness).

The researchers — Dr. Emmanuel Mignot of the Stanford University School of Medicine and Dr. Masashi Yanagisawa of the University of Tsukuba in Japan — arrived at the discovery through different approaches. Mignot wanted to understand the underlying causes of narcolepsy, while Yanagisawa was investigating a curious class of receptors that were known as "orphans" because the chemicals that activated those receptors were unknown.

"We never thought we would end up in sleep," Yanagisawa told Live Science. "This was a kind of biochemical fishing expedition."

In particular, Yanagisawa was interested in proteins at the surface of cells called G protein-coupled receptors (GPCRs). When the right chemicals are plugged into these receptors, they trigger a chain of events within cells. Various compounds that activate GPCRs had already been found to be useful as drugs, but there were many receptors with unknown triggers.

Yanagisawa and colleagues went fishing for those triggering chemicals in rat brains, isolating substances called peptides from the tissue and then exposing GPCRs to those peptides. "We got very lucky, initially," Yanagisawa said. The fifth or sixth receptor they tested had a hit. Through further experiments, they landed on two closely related peptides as the trigger, and they found a second related receptor to match.

They discovered that the peptides came from a part of the brain called the hypothalamus, which was known to be involved in eating behaviors. So they named the peptides "orexins" after the Greek word for appetite, "orexis."

It turned out, though, that orexins' main job wasn't to control appetite; rather, they help promote wakefulness, the opposite of sleepiness. Mice without functional orexin genes would suddenly fall over and remain immobile for a minute or two, the researchers found. Peering into those mice's brains, they found that the animals were suddenly entering REM sleep, a phenomenon also seen in people with narcolepsy with cataplexy.

At the same time, Mignot, the other winner of the Lasker Award, was learning that orexin deficiency is also behind a form of narcolepsy seen in dogs. He then went on to study the mechanism in humans with narcolepsy.

"It became, suddenly, a very, very convincing story," Yanagisawa said of the researchers' converging findings. Previously, the study of sleep involved damaging parts of the brain and then seeing how a lab animal's sleep changed in response.

"There was no molecular level, genetic level, description of sleep regulation mechanisms at all," he said. "So our papers really shed new light on sleep regulation."

Together, the researchers' work paved the way to a new class of insomnia treatments, called orexin receptor antagonists, which promote sleepiness by turning down wakefulness. They have also led to new narcolepsy treatments called orexin receptor agonists, which boost wakefulness by increasing the receptors' activity. The first in the latter class of drugs was just approved in August.

A life-changing hemophilia treatment

The second award, called the Lasker~DeBakey Clinical Medical Research Award, went to three scientists affiliated with the Japanese drug manufacturer Chugai Pharmaceutical. These researchers — Kunihiro Hattori, Takehisa Kitazawa and Tomoyuki Igawa — created an antibody that interacts with key proteins in the blood that produce clots and thus stop bleeding.

This antibody treats hemophilia A, a severe bleeding disorder caused by a genetic mutation. That mutation causes the body to not make enough factor VIII, one of the key blood-clotting proteins. Normally, factor VIII grabs hold of two other clotting factors, and this enables a chain reaction that results in normal blood clotting. Without enough factor VIII, there is abnormal bleeding.

The severity of hemophilia A varies, but people with the disorder frequently experience blood pooling in their joints, which causes chronic pain and impairs mobility; they can also bleed uncontrollably even in the absence of trauma.

The antibody treatment works by binding two other clotting proteins — factors IX and X — to create a structure that fulfills the function of the missing factor VIII. Hattori, who is no longer at Chugai Pharmaceutical, initially launched the effort in 2000 after hatching the idea to use an antibody to bind several clotting factors together. Kitazawa and Igawa then brought the idea to fruition using pharmacology and chemical engineering, respectively.

The antibody, called emicizumab (marketed as Hemlibra), was approved by the U.S. Food and Drug Administration in 2017, and over 100 additional countries have approved the drug since. Over 30,000 people have received the antibody treatment to date, according to the award announcement.

Parkinson's disease advocacy

The third and final award — the Lasker~Bloomberg Public Service Award — went to Fox, actor and founder of The Michael J. Fox Foundation for Parkinson's Research.

Fox began experiencing symptoms of early-onset Parkinson's in 1990 at age 29. He publicly announced the diagnosis in 1998, sparking new discussions around the often-stigmatized disease. Through interactions with existing Parkinson's advocacy groups, Fox realized the field faced a lack of funding that likely hindered the pursuit of better treatments and a cure.

Since its inception in 2000, the foundation has funded more than $3 billion in Parkinson's research, according to the award announcement.

"When we launched the Foundation, our goal was simple, yet ambitious — cure Parkinson's," Fox said in a statement. "I am humbled to be recognized by the Lasker Foundation and jury. I accept this honor on behalf of everyone living with Parkinson's and everyone with us in our shared mission to end the disease."

This article is for informational purposes only and is not meant to offer medical advice.

A bizarre squid has been filmed haunting the northeastern Pacific Ocean for the first time.

Researchers spotted the bigfin squid (Magnapinna) via remote video while using an uncrewed submersible to explore underwater mountains, known as seamounts, at a depth of more than 10,000 feet (3,000 meters) off the coast of California.

The footage, captured Aug. 7, represents the first confirmed live observation of a bigfin squid in the northeastern Pacific, according to the Monterey Bay Aquarium Research Institute (MBARI), whose scientists made the discovery with collaborators from the National Oceanic and Atmospheric Administration (NOAA).

Olívia Soares Pereira, a deep-sea ecologist and postdoctoral fellow at MBARI, said the squid was hovering over the seafloor with its arms and tentacles bent at a 90-degree angle — what the researchers called the "elbow pose."

"Based on the behavior of other deep-sea squids, we believe this pose could be a part of their feeding tactics," Pereira told Live Science in an email. "The arms and tentacles are extended so they do not get tangled up and passively capture prey that sticks to them."

Bigfin squid are the deepest-dwelling known squid and have been found more than 20,000 feet (6,000 m) below the surface. Most of the animals' total length comes from their tentacles and arms, which can be 20 times longer than their bodies. The individual in the video was about 4.1 feet (1.25 m) long, including body, tentacles and arms, according to MBARI.

The last time MBARI researchers encountered a bigfin squid was off Hawaii in 2001, though around 70 have been observed or collected in total, according to MBARI. Pereira said she saw two other bigfin squid during an expedition to the Mid-Atlantic Ridge — located along the Atlantic Ocean floor — with the Schmidt Ocean Institute earlier this year.

"When we saw this one, I couldn't believe my luck!" she added.

The team was piloting MBARI's Doc Ricketts submersible when they encountered the squid near the Davidson Seamount at a depth of around 10,751 feet (3,277 m), about 80 miles (130 kilometers) southwest of Monterey, during a 10-day Seamount Hotspots expedition between Aug. 3 and Aug. 12.

The researchers were investigating life around the Davidson Seamount and Sur Ridge, which are biodiversity hotspots within the Monterey Bay National Marine Sanctuary, a massive federally protected area off central California. Although these areas are known to be teeming with life, a bigfin squid was not on the list of animals the researchers expected to see.

"We were looking for thriving communities of deep-sea corals and sponges, brooding deep-sea octopus, and feeding beaked whales," Pereira said. "Finding a rare animal that we weren't specifically looking for highlights the incredible diversity and habitat complexity of this region."

Tristan Buckmaster, a mathematician at New York University, had just spent months working on what he believed could be a life-defining mathematical proof. Then, during a Sept. 6 meeting with OpenAI employees, he claims that he was issued a stark warning: "Why would you ruin your career?"

That exchange, which Buckmaster described in a detailed public statement this week, sits at the heart of a ballooning controversy around a famous set of mathematical equations called Navier-Stokes.

OpenAI says its artificial intelligence (AI) model has solved an outstanding problem tied to this 200-year-old set of fluid dynamics equations. The set of equations appears on the list of one of the seven Millennium Prize Problems posed by the Clay Mathematics Institute, and its solution comes with a $1 million reward. Buckmaster had been working on the same problem. And he has questions about how the company got there so fast.

The OpenAI breakthrough

The Navier-Stokes equations were formulated in the early 1800s by Claude-Louis Navier and George Gabriel Stokes. They're basically Newton's second law of motion for fluids, describing how any fluid moves: Push air with a fan blade, and the equations predict how that air will flow; or heat the atmosphere with sunlight, and they help forecast tomorrow's weather. They describe how planes fly and how blood moves through your arteries.

The problem is that nobody has proved whether the equations always produce finite answers. Could there be rare conditions that make the equations go haywire? This is called a "blowup," or singularity, which happens when a quantity that should represent something physical (like fluid speed or pressure) spirals toward impossible infinities at certain points in space and time.

Imagine the swirl of water circling a bathtub drain. The Navier-Stokes equations describe how it spins faster as it tightens toward the center. A blowup would mean the math predicts that spin is accelerating forever ‪—‬ an infinite speed at a single point. The bathtub can't do that, but if the equations can, that means the model we trusted for years is wrong and we wouldn't even know where it breaks.

Whether the Navier-Stokes equations can blow up is one of the most famous unsolved questions.

To find the answer, OpenAI used a technique called "forcing" ‪—‬ giving the simulated fluid a smooth, controlled nudge from the outside. Imagine flicking a spinning top with your finger to see if it would fall over ‪—‬ or, in the case of the Navier-Stokes equations, blow up.

OpenAI set roughly 10,000 AI agents to simultaneously work on the problem. The agents worked for about 88 hours straight, with 100 of them starting with the related Euler equations. This is a simpler cousin of Navier-Stokes that discards viscosity to describe fluid motion without internal friction.

After roughly 50 hours, OpenAI's agents found blowups in the Euler equations, OpenAI representatives wrote in a statement. This discovery convinced them that Navier-Stokes was within reach, and they turned their attention to the bigger problem.

OpenAI described the singularity as a vortex spiraling tighter and tighter, stretching and thinning like pulled taffy. The result was a fluid that, mathematically, spins itself into infinity.

OpenAI ran the proof through a program called Lean, software that checks every step of a mathematical argument. The agents "sent 2.7 million messages and used approximately 130 billion output tokens," OpenAI representatives wrote in the statement. At a Sept. 8 news conference, company representatives said a similar effort performed by a customer would have cost $15 million.

The controversy

The result has created a blowup of its own within mathematics, centered around claims that OpenAI's models may have been given a head start by using the work of Tristan Buckmaster and Levent Alpöge, a mathematician at rival AI company Anthropic.

The two mathematicians had been working on the same strategy (smooth forcing) applied to those same Euler equations. The approach itself was developed by Diego Córdoba, a mathematician at the Institute of Mathematical Sciences in Madrid, and Luis Martínez-Zoroa, another mathematician at CUNEF University in Madrid. Almost no one else in the field was using it.

Buckmaster said that on Aug. 15 that he and Alpöge achieved blowup results for the Euler equations with smooth forcing. On Sept. 3, Buckmaster wrote that he received word through Alpöge that OpenAI had caught wind of their progress and adopted the same method.

"When I heard 'forced,'" Buckmaster wrote in his public statement, "it was a bright red flag."

His concern was that the smooth-forcing approach wasn't obvious or widespread. "The ideas making this line of attack possible are due to Córdoba and Martínez-Zoroa," Buckmaster wrote, crediting the two mathematicians who developed the technique. "Almost nobody else I know of was working on it."

And yet, according to OpenAI, the company launched its Navier-Stokes effort on Sept. 1 ‪—‬ the same day it heard "rumors of other Millennium Prize resolutions." Buckmaster claimed, in his public statement, that those rumors were about his and Alpöge's work specifically.

Sam Altman, OpenAI's CEO, acknowledged that the company had learned of Buckmaster and Alpöge's work before making its announcement. "We were curious if ours could do it too," he wrote on X. He added that "the approaches appear to be different" — a claim Buckmaster disputes.

OpenAI's statement names both Buckmaster and Alpöge, credits their independent resolution of the forced Euler problem, and says the company offered to co-publish.

"I did not get an answer"

Buckmaster also revealed that he had been using OpenAI's Codex coding assistant throughout his research, putting drafts of the work into the tool. OpenAI trains its models on user interactions, and Buckmaster said he asked the company directly whether his Codex sessions had been accessed.

"I asked whether the model had been trained on, or had access to, our sessions in Codex, into which we had been putting all our drafts," he wrote. "I asked again, about training, and I did not get an answer."

OpenAI's enterprise agreements govern how customer data can be used. But it's unclear whether Buckmaster was using Codex under an enterprise agreement or as an individual consumer — a distinction that may determine whether his drafts were available for training.

In a statement on X, OpenAI representatives denied that company employees or agents saw the pair's work "by any means" until it was publicly released. However, "we cannot rule out that de-identified data derived from their usage of our products helped improve our models," they added.

Then, there is the question of authorship. Buckmaster alleges that Sébastien Bubeck, who leads OpenAI's math research, twice pushed for Alpöge to be cut from the paper that the two mathematicians were preparing. Buckmaster emphasized that Alpöge works at Anthropic, a rival AI company.

It was at that same Sept. 6 meeting that Buckmaster claimed that OpenAI presented him with two options, both of which required cutting Alpöge from authorship. He declined and said he told Bubeck that if OpenAI released its result as proposed, he would go public. Bubeck allegedly replied, "If you don't want me to be nice, then I don't have to be nice."

Bubeck has flatly denied the allegations, calling them "false and inflammatory" in a statement on X. "We did not use their prompt or proofs to prompt our models," Bubeck told Wired. Mark Chen, OpenAI's chief research officer, said at last night's news conference that he was "a little disappointed with the allegations."

"I have not seen OpenAI's proof," Buckmaster wrote. "I do not know what their model did, or how. I do not know whether our data was used. I am not accusing anyone of anything." He has called for an independent investigation into how OpenAI's work began.

In a closing line, he wrote, "I would much rather be talking about mathematics, Luis and Diego's ideas, and what this all means for the rest of us."

The community response

Córdoba, one of the original developers of the forcing technique, said he was stunned by how quickly the result had materialized. "We're a little bit in shock," he told Scientific American.

Other mathematicians have also responded to the news, with some expressing open dismay at how the results were released.

"We have now seen that even the rumor of someone working on a massive problem can trigger a massive amount of AI-powered effort to flatten it before the original research project has time to reach its full potential," Terence Tao, a professor of mathematics at UCLA, wrote on Mastodon. "The incentives may now be pointing in the direction of no longer sharing any promising research directions with the broader community, which would reverse centuries of traditions of open science and do serious long-term damage to the future of the field."

OpenAI's proof still awaits formal peer review, and the Clay Mathematics Institute has not yet issued an official verdict confirming or denying OpenAI's proof. But the episode has already surfaced troubling questions for the mathematics community. For example, when a company trains its models on the interactions of millions of users, who really owns the answers that emerge? And what does AI's involvement mean for the future of the field?

Those questions, unlike the Navier-Stokes problem, may not have a clean proof.

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The world's oldest known habitual drug use can be traced to an island in Indonesia, where ice age hunter-gatherers sucked on betel nuts — palm seeds that contain a neuroactive substance, a new study finds.

Scientists made the discovery after studying strange grooves in the teeth of two prehistoric hunter-gatherers. The deep grooves were caused by regularly sucking on betel nuts (Areca catechu), likely for relief from the pain of toothache, according to the study, which was published Wednesday (Sept. 9) in the journal Science Advances.

The partial skeletons of the two people were found on the island of Sulawesi, but their lives were separated in time by thousands of years. One of them, a man who died between about the ages of 40 and 50, lived between 25,000 and 16,000 years ago. This period roughly corresponds to the Last Glacial Maximum, the coldest part of the last ice age — although Sulawesi was not covered with ice at that time. The second person, who was around the same age when they died, lived on Sulawesi between 7,600 and 6,300 years ago, according to the study. The sex of this individual could not be determined.

Betel nuts contain a neuroactive compound called arecoline, which has a powerful stimulant effect when chewed with slaked lime, or calcium hydroxide. This early method of directly sucking betel nuts, however, would have only made the mouth numb.

These hunter-gatherers had so much dental damage, the new analysis found that they must have sucked on betel nuts almost continuously throughout their lives. But it seems these numbing nuts didn't have the desired effect in the long run. Instead, it may have made their dental conditions worse by eventually exacerbating any painful holes in their teeth.

"The more they sucked on the nut to relieve toothache, the worse that the damage to their teeth became," study first author Adam Brumm, an archaeologist at Griffith University in Australia, told Live Science. The grooves progressively became deeper, and in one individual they exposed the tooth's inner pulp cavity. "It would have been excruciatingly painful," Brumm said.

Although a 2017 study showed that Neanderthals used the bark of plants like poplar (genus Populus) for its pain-killing properties (poplars contain salicylic acid, a form of the active ingredient in aspirin), this is the earliest evidence of a drug from plants being used habitually, Brumm said.

Plant-based drugs have been used in many other prehistoric societies: 10,000-year-old traces of the pollen of a psychedelic cactus have been found in Peru, and 13,000-year-old residues of alcoholic beer have been found in Israel.

Addictive nut

After determining the likely cause of the grooves, the researchers tested whether sucking on betel nuts — a behavior not seen before — resulted in a neuroactive effect. Their test subjects, genetically-engineered frog eggs with human neuroreceptors, revealed there was a neuroactive effect. Then, they examined samples from the teeth, which revealed traces of betel nut use.

Betel nut, also known as areca nut, is still widely used today in parts of South Asia and Oceania. Today, however, betel nut users mix it with slaked lime to make a chewable wad that has a stimulant effect. This chewable wad, also called a quid, is strongly addictive, and is used by an estimated 600 million people worldwide. But arecoline is also carcinogenic, and betel nut quids are often mixed with tobacco, so users are often diagnosed with mouth cancer.

The researchers speculate that the use of slaked lime with betel nuts originated much later, during the Neolithic, or "New Stone" Age, about 4,000 years ago on Sulawesi, when slaked lime was added to pottery to prevent it from shrinking and cracking during firing.

"It now seems probable that betel chewing as we know it evolved from a much simpler, older practice of just sucking on the intact nut," the researchers wrote in the new study.

It's likely that people of all ages used this remedy for toothache in prehistoric times, but the grooves only became apparent in mature people who had become addicted to the practice, Brumm said.

Drug use started before farming

The earlier betel-sucking man predated the Neolithic period not only in Sulawesi but also in the Fertile Crescent, where people began practicing agriculture around 12,500 years ago, Brumm said. Archaeologists have long debated whether people began using neuroactive plants as drugs before or after the introduction of farming, but the new finding shows that psychoactive drug use happened thousands of years earlier, Brumm said.

The new study is a "fantastic piece of research," Elisa Guerra Doce, a prehistoric archaeologist at the University of Valladolid in Spain who was not involved, told Live Science in an email.

The new study gives "particularly compelling and direct evidence for the antiquity of drug use," she said.

Guerra Doce is an expert on the prehistoric use of plants as neuroactive drugs. "In the specific case of betel nuts, the findings are especially significant because they also reveal the prehistoric roots of a deeply established cultural practice in Southeast Asia and the Pacific," she said.

The study also highlights how the prehistoric people of Sulawesi explored their natural world and figured out that it not only provided subsistence and medicinal resources but also had "substances that became integrated into social and cultural traditions over thousands of years," Guerra Doce said.

Abnormally high temperatures on the Tibetan Plateau triggered two catastrophic rainfall events halfway around the world in California and nearby states in early 2017 and 2023, a new study reports.

This is the first time that researchers have identified this link, known as a climate teleconnection. The results could improve forecasts of extreme weather in the western U.S., which, in turn, could improve warnings for coastal communities and potentially save lives as well as billions of dollars in property damage, the study's authors say.

In December 2016 and February 2023, the Tibetan Plateau was warmer than usual for these times of the year. Roughly one month after each of these hotspots appeared, parts of California, Nevada, Oregon, Utah and Arizona received record-breaking precipitation, causing a total of around $6.6 billion in damage, according to the study, and killing at least nine people.

State-of-the-art forecast systems, which rely heavily on ocean conditions like El Niño, failed to predict this extreme rainfall, said study first author Yongkang Xue, a distinguished professor of atmospheric and oceanic sciences at UCLA. The record precipitation occurred during La Niña years, which are typically associated with dry conditions in California and neighboring regions, further complicating the picture.

"This study provides the first evidence from observational data analysis and model simulations that abnormally high early-winter temperatures on the Tibetan Plateau led to stronger atmospheric rivers along the U.S. Pacific Coast, driving heavy regional precipitation," Xue told Live Science in an email.

Atmospheric rivers are narrow, elongated corridors of intense water vapor transport. They are key drivers of precipitation and floods in the western U.S., and in this case, they interacted with giant waves in Earth's atmosphere, called Rossby waves, to produce devastating rainfall in the winters of 2017 and 2023.

As temperatures increased over the Tibetan Plateau in late 2016 and early 2023, a strong gradient formed with the regions north and south of the plateau. This generated an atmospheric disturbance that propagated eastward along the jet stream via Rossby waves, triggering what is known as a Rossby wave train between the Tibetan Plateau and the Rocky Mountains, Xue said.

A Rossby wave train is a series of waves traveling in the same direction and at regular intervals around alternating high- and low-pressure systems. As the wave trains initiated over the Tibetan Plateau reached the northeastern Pacific Ocean, they suddenly broke, and this supercharged the weather above California and adjacent states, Xue explained.

"Over the eastern Pacific, the wave breaks — much like a towering ocean wave crashing near the shore," he said. "This wave-breaking mechanism reduces static stability and significantly intensifies atmospheric rivers, ultimately driving extraordinary, heavy precipitation along the West Coast."

The findings, published Wednesday (Sept. 9) in the journal Science Advances, are based on complex modeling and analyses of precipitation and surface temperature data, among other observations. The results are part of a new body of research examining the influence of land temperatures on weather patterns, and this is the first study of a winter season, Xue said.

The analysis is a "very specific and impactful case study," said Matthew Huber, a professor in the Department of Earth, Atmospheric, and Planetary Sciences at Purdue University in Indiana, who was not involved in the research. The results build on the well-established idea that extra heat on a mountaintop affects Rossby waves almost as if the mountain had suddenly grown, Huber told Live Science in an email.

Large mountains and plateaus generate waves in the jet stream that are thousands of miles long — "so long that we also call them planetary waves," Huber said. An increase or drop in temperature so high up above sea level adds or subtracts from the atmospheric disturbance that already exists due to the elevation.

"You can imagine the waves in the jet are kind of like a motorcycle rider going off a jump," Huber said. "How far and how high they jump depends on how fast they are going and how big a ramp they are going over."

The models replicated the extreme weather with surprising accuracy, raising hopes that the Tibetan Plateau could be integrated into early warning systems for the western U.S., Xue said. "As similar, though less severe, events become more [frequent] and extreme weather escalates globally, understanding this teleconnection allows forecasting agencies to better warn coastal communities of impending extreme conditions," he said.

Huber agreed that the results could help to better prepare for weather hazards. "This study shows that accurate predictions of weather events in the U.S. West are very sensitive to tiny changes very far 'upstream' and these upstream features are identifiable and traceable," he said.

Astronomers just dropped a video 27 years in the making: the highest-definition animation of a gargantuan black hole jet blasting out of a distant galaxy and twisting off into space.

The video, made from 116 images taken between 1995 and 2022, captured a blazar known as 3C 345, in the constellation Hercules. A blazar is a sort of quasar — a bright, feeding supermassive black hole embedded in the center of a faraway galaxy — that emits huge jets of gas into its environment. The jets blaze at nearly the speed of light and are charged with highly concentrated X-rays and gamma rays.

As described in an Aug. 26 study in the journal Nature, scientists gathered the images of 3C 345 using decades of observations by the Very Long Baseline Array (VLBA), a network of 10 telescopes spread across the U.S. (VLBA had two programs that caught views of the jet, called BEAM-ME and MOJAVE, which collectively followed hundreds of blazar sources.)

To turn those hundred-or-so images into an animated movie, the team used an AI neural network named Kine, achieving a resolution four times higher than that of any individual image. By doing so, the researchers mapped the speed of the black hole jet to the highest precision yet. (Several study co-authors had previous experience boosting the resolution of distant black hole images while working at the Event Horizon Telescope Collaboration, the team behind the first image of a black hole.)

"The higher quality of our video reconstruction enabled a detailed measurement of the plasma velocity in the jet," study first author Marianna Foschi, a postdoctoral researcher at Caltech, told Live Science in an email.

A big, bright surprise

The researchers were surprised to see that the mighty jet's brightest components were flying at 10 to 13 times the speed of light while the gas surrounding it was zooming at about nine to 12 times the speed of light.

"This is unexpected because the general consensus is that these bright components are shock perturbations moving through the plasma, and as such they should have a higher velocity compared to the surrounding fluid," Foschi said. "Our work does not invalidate the shock model in general, but it puts it into question, at least in the case of this specific source."

VLBA uses radio antennae across the continental U.S. to map the sky, providing a wide view of the universe. But while VLBA has a comprehensive view of the sky, it lacks very fine details. The array is designed to generate a two-dimensional image with elements based on a measurement between two of the array's telescopes. Because the array has only 10 telescopes to do those measurements, however, its pixel resolution is limited.

That's where the Kine AI model makes a difference. The goal of Kine's work, Foschi said, is to develop an imaging algorithm that can create videos of observations at different times, focused on astronomical sources with variable brightness.

Kine is a neural network — a type of machine learning model that uses layers of "neurons" (computing nodes) to learn from a dataset, similar to the way a human brain learns. Kine can "process observations at different times, while learning and leveraging the spatio-temporal correlations present in the data," the research team wrote in the paper, referring to time and the three dimensions of space.

Foschi said the team is eager to apply Kine to other astronomical observations. "We believe this method will drastically change the way jet dynamics is studied from observations," she said. "In fact, our method enables a precise measurement of the projected velocity at any point in the jet."

See how much you know about black holes with our black hole quiz!

Artificial intelligence (AI) systems can now hold conversations, reason through difficult mathematical equations, and respond in ways that seem more human. As AI grows more advanced, the question is shifting from the realm of science fiction to scientific debate.

A recent preprint study examined "consciousness steering," an AI-tuning technique that affects how an AI model expresses ideas about self-awareness. The study suggested that if AI is allowed to claim consciousness, it's also more likely to say it believes in ghosts or vampires. But today's most advanced models with these safeguards enabled are unable to perceive consciousness in other sentient beings, like humans and animals — which carries different ramifications.

Although the study hasn't been peer-reviewed yet, it raises a big question in the world of AI research: Could AI one day develop real consciousness, regardless of whether or not it simply claims to be conscious? And there's perhaps an even scarier question: Could we even tell if the technology was conscious? Vote in our poll below, and leave your thoughts in the comments.

Archaeologists excavating in southwestern China have discovered a cave that was used by Denisovans for more than 100,000 years. Five human fossils, scores of stone tools, and hundreds of animal bones recovered from the cave reveal for the first time that the enigmatic Denisovans thrived in a forested environment where they hunted and ate large game animals.

Denisovans were a lineage of humans who lived in Asia and went extinct around 30,000 years ago. Ancient DNA has shown that Denisovans, Neanderthals and modern humans (Homo sapiens) are distantly related and that all three groups interbred in the past. But while archaeologists have found numerous Neanderthal and modern-human skeletons, Denisovans are known from only a handful of fragmentary fossils scattered from Siberia to Laos. This lack of evidence has severely limited experts' understanding of Denisovans' bodies and their culture.

In two studies published Wednesday (Sept. 9) in the journal Nature, researchers detailed their excavation of Bianfu Cave in southwestern China. Animal bones and ancient tools revealed that the cave was used from 190,000 to 70,000 years ago, and five human fossils dating to between 134,000 and 167,000 years ago confirmed that the people who used the cave were Denisovans.

Bianfu Cave is in the Yunnan province of southwestern China. In 2019, archaeologists excavated several stratigraphic layers of the cave and discovered nearly 1,400 stone artifacts, more than 64,000 mammal bones, and four teeth from an unknown human lineage. The Yunnan area is where Denisovans and modern humans are known to have met and mated, so researchers were unsure which group had used tools to butcher animals inside Bianfu Cave.

In one study, a research team used a technique called zooarchaeology by mass spectrometry (ZooMS) to quickly and efficiently screen the bone fragments from Bianfu Cave. ZooMS is a form of protein analysis that involves extracting collagen from the bones of an unknown species and comparing the protein pattern to the unique "fingerprint" of reference animals.

When the researchers applied the ZooMS technique to the Bianfu Cave bones, they discovered that three of the fragments had a collagen pattern found in members of the Homo genus. Then, using proteomic analysis, the researchers found that two teeth and three bones from Bianfu Cave had a particular amino acid variation linking the fossil remains with Denisovans.

Denisovans are still poorly understood, in part because no complete skeleton has ever been found. Most of the Denisovan fossils that experts have studied are pieces of the skull and teeth. A tiny finger bone and a rib fragment were all that had been found of Denisovans' bodies before the Bianfu Cave excavation. But one of the three bones identified as Denisovan through ZooMS was a fragment of a radius, one of the paired bones in the forearm. It is the only Denisovan radius found to date.

The newly discovered radius has a large head (where it connects to the humerus at the elbow) that is more similar to those seen in Neanderthals than in modern humans, but its overall shape is more similar to modern-human radii, the researchers wrote in one of the new studies. The fact that the Denisovan radius was shaped more similarly to the radius in humans "likely provided functional advantages for lightweight, precise manipulation," study co-author Qiaomei Fu, director of the Ancient DNA Laboratory at the Institute of Vertebrate Paleontology and Paleoanthropology, part of the Chinese Academy of Sciences, in Beijing, told Live Science in an email.

The unique features of the Denisovan radius also suggests that the Denisovans living near Bianfu Cave had different biomechanical demands on their bodies and different behavioral adaptations, the researchers noted.

Denisovan stone and bone tools

In a related study, researchers looked at the entire cultural sequence from Bianfu Cave to work out what Denisovans were doing there.

Of the nearly 1,400 stone artifacts recovered from the cave, there were about 200 flake tools, many of which were made from a sedimentary rock called sandy mudstone. These tools left marks on a number of animal bones discovered in the cave, suggesting that Denisovans regularly hunted, butchered and extracted marrow from cow- and deer-like animals, the researchers wrote in the study.

But the stone tools found at Bianfu Cave are different from the more sophisticated ones that Neanderthals made around the same time. The Denisovan stone tools appear to have been crafted quickly and efficiently from locally available materials, according to the study. The researchers, however, discovered that Denisovans at Bianfu Cave were also making bone tools, which Neanderthals did as well. This suggests that bone tool use may have been more widespread among Pleistocene human groups than experts previously thought, the researchers wrote, and it highlights the need to better understand the human evolutionary record of eastern Asia.

Although the studies have contributed new information to archaeologists' understanding of the enigmatic Denisovans, more work needs to be done, according to the researchers.

"We hope that similar proteomic analyses will aid in the identification of further Denisovan long bones in the future," Huiyun Rao, an associate professor at the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, and colleagues wrote, "to further understand the adaptive behavior of Denisovans in response to climate change or competitive pressure from contemporary hominins."

What do you know about early humans? Test your knowledge with our human origins quiz!

The moon may have formed in as few as five hours after the cataclysmic collision between Earth and a long-lost protoplanet, new simulations suggest. The surprising findings could help shed light on other historic impacts throughout our cosmic neighborhood and beyond.

Experts strongly suspect that the moon was created when a Mars-size space rock called Theia smashed into an early version of our planet, back when the solar system was young and extremely unstable. This colossal impact likely would have turned the once-neighboring worlds into spinning clumps of molten rock that eventually coalesced and cooled into the versions of Earth and the moon we see today. Without this collision, which also may have left chunks of Theia buried deep within our planet, many scientists think that life may have never existed on Earth.

Lunar rocks collected during NASA's Apollo missions have provided evidence to support this theory, dubbed the giant impact hypothesis. These samples also tell us that the moon is around 4.5 billion years old, meaning the collision occurred roughly 100 million years after the sun was born. But although scientists have previously simulated the impact event, it has been tricky to ascertain exactly how the moon formed and how long it took to emerge after the Earth-Theia collision.

In the new study, published Sept. 1 in The Astrophysical Journal Letters, researchers conducted a series of simulations focusing on the varying potential geological properties of both Earth and Theia prior to their collision. This factor has been relatively understudied until now.

"When you simulate the Earth and the moon as colliding bodies with [different] geologic properties, it changes how the moon forms out of that impact — that's something we considered unnecessary before," study first author Adeene Denton, a geologist and planetary scientist at the Southwest Research Institute in Boulder, Colorado, said in a statement.

Until now, simulations of the Earth-Theia impact have focused mainly on the masses of the colliding neighbors. But in the new study, the researchers were most interested in the material strength of the two bodies, particularly the hardness of their exteriors.

"Models have evolved to include material strength, something that's really important when you're studying collisions between smaller bodies like asteroids," Denton said. "We weren't sure if it would matter for the moon or not. When we did the simulations, we found it actually matters quite a bit."

The main factor in the strength of colliding bodies is temperature. Both Earth and Theia were very young when they smashed together, so they were still hot and had soft or molten surfaces. These properties would have cushioned the collision, allowing the debris to stay largely intact and enabling the moon to form more quickly. But when the giant impact hypothesis was first proposed (in 2001), researchers initially thought the collision occurred much later, meaning that the bodies would have cooled and become more brittle. In this case, their collision would have created a larger field of rocky debris that would have taken longer to coalesce.

Researchers simulated the collision using a range of potential temperatures and found that under the most extreme scenario — where the pair were at their hottest — the moon could have formed in just five hours. However, this is just one potential outcome, and there is no way of knowing exactly how hot — and, therefore, how strong — Earth and Theia really were when they smashed together.

When the moon took shape, it was initially covered with a magma ocean that took hundreds of millions of years to solidify. Even then, its increased proximity to Earth meant that it was likely a volcanic hellscape. However, over time, it moved away from our planet, cooling further, and it is now assumed to be geologically dead. (The moon is continuing to slowly move away from us and could eventually escape our planet's gravity entirely, if the dying sun doesn’t destroy it and us first in around 5 billion years.)

The new simulations highlight the importance of material strength in planetary impact modeling, which could change what we know about other ancient collisions, like the one that knocked Jupiter's moon Ganymede off its axis or the one that birthed Saturn's moon Titan.

Additionally, the findings could have implications in the search for exomoons — the hypothetical moons of distant exoplanets, which have so far remained elusive, according to Live Science's sister site Space.com. Until now, one of the main ways astronomers have been hunting for these alien satellites is by looking for debris fields around exoplanets. However, if the moon is anything to go by, these debris fields could be very short-lived and difficult to identify.

The patient: A 55-year-old man in Bangladesh

The symptoms: The man went to the emergency room with severe abdominal pain that he said began five hours prior to his visit.

What happened next: During a physical examination, doctors noted that the patient's temperature and blood pressure were normal. His heartbeat was slightly elevated, at 110 beats per minute (bpm). (A typical resting heart rate for adults is 60 to 100 bpm.)

The man explained that one day earlier, an eel had "entered through his rectum accidentally," his doctors wrote in a report of the case. At the time of the encounter, the man was wearing a lungi — a type of long skirt often worn by Bangladeshi men — and he explained that the eel entered his lungi through the opening at the bottom and then wriggled into his anal canal.

He did not seek medical attention immediately after this happened, as he had hoped the fish would exit on its own.

When the doctors kneaded the patient's abdomen, it was rigid and tender. They ordered an X-ray, which revealed a dark, eel-shaped shadow on the right side of the abdomen.

The diagnosis: The X-ray showed a crescent-shaped gas shadow under the right part of the man's diaphragm and hinted that he had developed peritonitis — inflammation of a membrane called the peritoneum, which covers the abdominal organs. Peritonitis is usually caused by a bacterial or fungal infection, but it can also develop if fluids from other organs leak into the peritoneum.

If the condition is not treated quickly, it can lead to a life-threatening infection that can spread rapidly through the body.

The treatment: Doctors administered IV antibiotics, as well as fluids and anti-ulcer medications, which help repair injuries to organs' outer mucosal layers and prevent deeper tissue damage.

Due to the peritonitis, the doctors determined that the patient was at risk of septicemia, or "blood poisoning," in which pathogens invade the bloodstream. They decided to operate on the patient immediately and remove the eel via a laparotomy, a surgical technique that creates an opening in the abdominal wall and provides access to the pelvic organs.

After making an incision in the man's sigmoid colon — the S-shaped section of the large intestine adjacent to the rectum — the surgeons extracted the eel from the peritoneal cavity, the space surrounding the abdominal organs and encased by the peritoneum.

The eel measured nearly 2.2 feet (0.6 meters) long and was still alive. Perhaps, the doctors hypothesized, the eel was able to continue breathing by punching through the wall of the man's colon and squeezing into the peritoneal cavity, which contains a pale-yellow fluid that reduces friction between organs. This peritoneal fluid is mostly water, but it also contains glucose, electrolytes, proteins, enzymes, white blood cells and urea, a compound found in urine.

The surgeons then performed a sigmoid colostomy, creating an opening in the abdomen as an exit point for contents of the man's large intestine. In this way, they bypassed the damaged section of sigmoid colon to prevent leakage of fecal matter that could lead to further infection. Four days later, the man was symptom-free and was discharged from the hospital. The report did not document any follow-up visits.

What makes the case unique: Traumatic perforation of the intestine by foreign objects is uncommon, and cases involving live animals are "exceedingly rare," the authors wrote in the report. However, foreign objects often find their way into the human body through accidental ingestion or deliberate insertion into the rectum. Some deliberately inserted objects, such as vibrators, are designed for this purpose. Others are not; these have included chicken bones, light bulbs, metal rods, glass bottles and kitchen whisks.

Penetration of the colon by a live fish is an "unusual and scarcely documented event," the man's doctors added in the report. They noted one reference to such a case that appeared previously in scientific literature and involved a 50-year-old male patient in Hong Kong. In that case, the man knowingly inserted the eel — which measured more than 1.6 feet (0.5 m) long — into his rectum, allegedly in an attempt to relieve his constipation.

This article is for informational purposes only and is not meant to offer medical advice.

Can you guess the diagnosis in these strange medical cases? Find out with our diagnostic dilemma quiz!

In this excerpt from "The Carbon Wave" (MIT Press, 2026), author Leah Stokes, an associate professor of environmental politics at the University of California, Santa Barbara, looks at a hopeful moment in U.S. politics when climate change took center stage: when Rep. Alexandria Ocasio-Cortez and Sen. Ed Markey ramped up calls for a "Green New Deal."

In September 2017, a still­-unknown Alexandria Ocasio-­Cortez watched as Hurricane Maria devastated Puerto Rico. Electricity went down for months. Like thousands of Puerto Ricans, her grandfather died in the storm's aftermath. She could see how climate change was hitting her community harder than others.

And it wasn't just Ocasio-­Cortez's community: the year before, she'd traveled to Standing Rock, North Dakota, to see firsthand how the fossil fuel industry was harming Indigenous people. It was mere weeks after the 2016 election, and the resistance to Trump had found its center in a makeshift camp along the Missouri River. People had united to oppose an oil pipeline.

Serendipitously, the day after Ocasio-­Cortez left the protest, a progressive organization reached out to ask her to run for Congress. Moved by the activists at Standing Rock, she said yes. In 2018, she ran a long-­shot primary campaign in a Bronx district occupied by a ten-­term congressman in House leadership. Her platform included an idea that some had bandied about before, but no one had developed in earnest: a Green New Deal. As she told journalists that summer, "The Green New Deal we are proposing will be similar in scale to the mobilization efforts seen in World War II or the Marshall Plan. We must again invest in the development, manufacturing, deployment, and distribution of energy, but this time green energy." In June, she won the primary. Her election signaled the beginning of a broader shift: climate change was back on the political agenda.

That fall, the world's leading climate science organization, the Intergovernmental Panel on Climate Change —­ often called the IPCC —­ released a short report concluding that limiting warming to 1.5°C would require emissions to fall by almost half by 2030. The news ricocheted around the world, with headlines like "We Have 12 Years to Limit Climate Catastrophe." In my own neighborhood, someone printed a copy and stuck it in the free lending library, labeling it "important reading." The report changed how many people thought about the problem: it wasn't something we could deal with in 50 years; it was something we had to deal with today.

In the November 2018 midterm elections, two years into the first Trump administration, Democrats won big, paving the way for Nancy Pelosi to return as Speaker of the House after eight years as the minority leader. Days later, a group of young activists from the Sunrise Movement staged a sit-in at her office. Their bright yellow and­ black signs read "We have 12 years. What’s your plan?" referencing that scientific report.

Newly elected Representative Ocasio-­Cortez joined the action that day. She told the organizers they needed a clear ask and encouraged them to call for a Green New Deal. The idea broke through, sparking widespread coverage across the country. It was a new, hopeful vision for climate policy. These young people were not just talking about the climate disasters we needed to avoid —­ they were explaining how investments in clean energy could create good jobs. They were showing us the better world we could build together. If we only tried.

I watched these developments unfold in DC from my office by the Pacific Ocean and wanted to be a part of it. I wouldn't have to wait long. The Green New Deal held a force like gravity, pulling people into its orbit. By chance, I met some of the people tied to Ocasio-­Cortez at a conference and was invited to an early gathering to develop the idea into more detailed policy. By then, she'd released a framework for the plan with Senator Ed Markey of Massachusetts.

The meeting was held in March 2019, at a hip hotel in DC's Adams Morgan neighborhood, miles away from the Capitol. A wide swath of people were invited: youth activists, environmental justice leaders, political organizers, think tank wonks, and a few academics like me. It was a contentious meeting that opened with a protest, revealing fissures in the movement that would eventually grow into large cracks. Some people believed that frontline communities facing the greatest pollution burdens were not being adequately consulted or invited to participate in the event. At the time, I didn't understand these dynamics between the climate and environmental justice movements. I was just a political science professor trying to understand how I could make my work more practical and help get a climate law passed if we got the chance.

It was at that event that I met Varshini Prakash, the executive director of the Sunrise Movement. I’d seen her photo many times, standing in the middle of Pelosi's office with her dark red jacket over a black­ and yellow T-­shirt, surrounded by young people sitting on the floor. Four months had passed since the sit-­in, and Varshini had ricocheted to the center of the climate movement. But she was also a recent college grad in her mid-­twenties, feeling a heavy burden from the climate crisis and the work involved in fighting it. At one point during the meeting, she spoke frankly about the stress that was on her and other young activists and cried. I found her vulnerability moving.

The fact was, Varshini had already changed history. She'd given me, and millions of others, a sense of hope and possibility. It was her actions, alongside all the other organizers in the Sunrise Movement, that brought us together in that first DC convening, and in countless other meetings to come. She inspired me to believe that I could do something bigger if I tried.

Too often, the way we think about cause and effect is simplistic. We're fed a linear model that favors the immediate. One person is responsible for their own carbon footprint. One person only has one vote. One person can only do so much. From this perspective, standing against more than a century of fossil fuels running through the heart of our society, it can feel like there's nothing we could do to shake the system loose. We're too small. Mere drops. But drops in the ocean can make waves.

Excerpted from The Carbon Wave: A Story of Democracy, Parenthood, and the Race to Protect Our Planet by Leah C. Stokes. Reprinted with permission from The MIT Press. Copyright 2026.

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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.

"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."

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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In the event of a global catastrophe, such as a nuclear war, an enormous volcanic eruption or large asteroid strike, the best place to be is Australia, according to a new study.

Researchers looked at the places that were most resilient to global catastrophic risks, which are events that would kill more than 10% of the global population over several months or years.

"These kinds of catastrophes are under-researched" because they are not very likely, study first author Florian Ulrich Jehn, a researcher at FernUniversität in Hagen, Germany, told Live Science. "That makes them easy to ignore."

But they are still possible — and no country would be unaffected if they occurred, he said. And some places are more vulnerable than others.

In the new study, published Aug. 23 in the journal Global Challenges, researchers analyzed studies across a variety of disciplines such as food security, biological weapons, and volcanism, to identify potential global catastrophic risks and the factors that helped communities to endure them in the past or on a smaller scale. They also brought in subject experts to add discipline-specific papers to their database.

The team identified three broad types of risk: events that would block out sunlight, such as nuclear war or a huge volcano explosion); events that destroy global infrastructure, such as a geomagnetic storm or massive cyber attack; and biological hazards, such as natural or human-caused infectious diseases that would kill much of the population.

These events, the authors wrote, would have significant and long-lasting global consequences. Many would result in global famine from crops failing and trade networks falling apart. "The food system is often the thing that gets you," Jehn said.

A trade-off of risks

The team identified characteristics that made countries more resilient to catastrophe and better able to feed their inhabitants. And while "no single place on Earth" would be resilient against all catastrophic risks, the authors wrote, some would fare better than others.

The team found that wealthier countries and regions with a strong industrial base that are not highly reliant on global trade are better able to weather global disasters.

With a strong industrial base, countries are able to manufacture goods that they cannot import, making them more resilient.

Geography also plays a role. Large islands have an advantage over continents because they can easily isolate, but they also need to have an economy that can at least partially support itself, the researchers said. If an island is highly reliant on international trade, like Japan, it will struggle if global trade networks are disrupted, the study found.

Certain countries and regions are less resilient in the face of some types of catastrophes, even if they are wealthy. For example, countries with nuclear capabilities, such as the U.S., the U.K., France, Israel, Russia, Pakistan, and India, are more at risk of being involved in nuclear war. This makes the Northern Hemisphere, where NATO countries are situated, more vulnerable to nuclear attack than places in the Southern Hemisphere.

There are also fewer volcanoes in the southern half of the globe, while the Southern Hemisphere has more ocean to act as a climate buffer, making countries there more resilient to a huge volcanic eruption, the study found.

Global resilience

There are some factors that make all countries better able to endure disasters in general, such as democratic processes and equality, Jehn said.

"When these catastrophes happen, you have to make the right decisions, and this depends on whether your country has functional governance," Jehn said. "Inequality makes governance worse, because it leads to things like elite rivalries, or less state capacity."

Australia came out as the best location to weather a catastrophic event that decimated global populations. It is in the Southern Hemisphere, so far away from the most likely location of a nuclear conflict (although the authors warn that it is allied with the U.S., which might increase its risk exposure). It is a major food producer, with diverse climatic zones, and has significant energy infrastructure.

Next best spots are Argentina, Brazil and New Zealand. New Zealand ranks lower than Australia because it has active volcanoes, a small industrial base, and is surrounded by water and vulnerable to tsunamis. Meanwhile, Brazil and Argentina have high levels of inequality and historical political instability, the authors wrote.

They also note that Iceland was a contender for a safe refuge, but its location in the far north makes it vulnerable to temperature shocks if a major incident were to block out sunshine.

The U.S. is not particularly well-placed to weather a global catastrophe, the study found. The country is exposed to the threat of geomagnetic storms because of its location and to nuclear war. The authors also pointed to the country’s poor COVID-19 outcomes, which appeared to be due to "a lack of political will and poor social cohesion."

David Denkenberger, director at Alliance to Feed the Earth in Disasters (ALLFED) and a researcher at the University of Canterbury in New Zealand, told Live Science that the new study aids our understanding of future risks by considering a wider range of catastrophes.

"No country is resilient to every catastrophe, and this is an important central finding," he said. "A useful next step would be to quantify the relative likelihood and severity of different catastrophes, and the importance of different resilience factors, because these factors can involve significant trade-offs," said Denkenberger, who has previously collaborated with Jehn but is not an author on the paper.

How to be more resilient

Even though these global catastrophes are unlikely, it is important to include them on national risk registers and have international trade agreements in place in case they come to pass, Jehn said. "When global catastrophes happen, then you would likely have to restructure the food system — where it is produced, where it is traded," he said. "The chance to find a good compromise after the catastrophe has happened seems slim."

Denkenberger echoed his comments. The study, he said, "makes it clear that regional resilience to global catastrophic risk requires investment in practical preparedness, including food-system resilience, critical infrastructure, coordinated trade and governance."

Two distinct climate regimes that could trigger runaway methane emissions are emerging in Siberia due to Arctic warming, new research suggests.

While western Siberia is becoming wetter in response to rising heat and moisture transported from the North Atlantic Ocean, eastern Siberia is getting drier and more prone to wildfires, a study published Aug. 6 in the journal Science finds. The Yenisei River (also spelled Yenisey) in central Russia delineates the separate environmental states — referred to as regimes because they describe specific types of climates — on each side of the basin, the study authors said.

Between 2010 and 2023, methane emissions from Siberia rose by 5% per year, with western Siberia releasing methane mainly via microbial activity in thawing soils and eastern Siberia discharging the powerful greenhouse gas through biomass burning, the results showed.

"Given the observed increases in permafrost thaw, wetland activity, and wildfire occurrence, an increase in methane emissions was expected," study co-author Paul Palmer, a professor in the School of Geosciences at the University of Edinburgh, told Live Science in an email. "What is surprising is how large and sustained the increase appears to be."

Annual methane emissions grew by about 13.2 million tons (12 million metric tons) over the study period, almost mirroring the rate of increase in methane emissions from wetlands worldwide. Although Siberia currently makes up only about 5% of global methane emissions, the region is becoming one of the fastest-growing natural methane sources on the planet, Palmer said.

In their study, Palmer and his colleagues integrated satellite observations with near-surface measurements to map methane emissions from Siberia over time. Instead of adding up individual methane sources on the ground, the researchers used a modeling method known as a methane flux inversion system, which helped them limit the uncertainty in their estimates to roughly 10%.

Siberia is vast, remote, sparsely instrumented and currently inaccessible for many scientists due to the Russia-Ukraine war, making it hard to monitor methane consistently by any means other than satellites. Although satellites rely on sunlight, of which Siberia gets very little in the winter, most methane emissions are thought to occur in the spring and summer, when Siberia gets more sunlight, Palmer said.

The results of the study show that Arctic warming amplifies methane emissions via distinct pathways in western and eastern Siberia because the regions are influenced by different climate patterns. The researchers also used climate models to predict future methane emissions from Siberia and found that additional warming could unleash millions of tons of greenhouse gases stored in forests and permafrost, which would further accelerate the warming trend.

In western Siberia, methane is released mainly from permafrost, or ground that has stayed frozen for at least two consecutive years. Siberia holds 46% of the Northern Hemisphere's permafrost, and this icy sediment traps vast amounts of carbon that have accumulated for thousands of years, Palmer said.

Western Siberia is influenced by the Scandinavian pattern of atmospheric circulation, a climate connection that consists of a main circulation center over Scandinavia and opposing weaker centers over Western Europe and eastern Russia. Global warming makes the Scandinavian pattern transport more warmth and moisture to western Siberia from the North Atlantic. Together with soaring temperatures in western Siberia itself, this triggers extensive permafrost thaw and unlocks carbon that microbes can convert into methane.

Conversely, eastern Siberia is influenced by a climate pattern known as the Arctic Oscillation, which causes atmospheric air pressure to "seesaw" between the Arctic and the Northern Hemisphere's middle latitudes. Climate change affects the Arctic Oscillation, leading to persistent high-pressure systems that intensify heat waves, reduce cloud cover and promote wildfires in eastern Siberia, Palmer said.

The climate models showed that methane emissions will increase with temperature rise and that the increase could become steeper the hotter the world gets, triggering a feedback loop.

"Eastern Siberia appears to be the main driver of the projected increase because it is warming faster than western Siberia and has seen a sharp rise in extreme wildfires," Palmer said. "Whether that trend continues will depend on how much vegetation remains available to burn, but there is also evidence that fires may be accelerating permafrost thaw and the release of methane from previously frozen ground."

However, the rise in methane emissions reported in the study is small relative to global and projected future emissions, especially if wildfires are already destabilizing eastern Siberia's permafrost, Palmer said.

"Siberia's vast permafrost carbon store is a sleeping giant," he said. "Continued warming risks waking up a much larger source of greenhouse gases."

This iconic photo, captured by an American astronaut on board the International Space Station (ISS), shows a lengthy trail of thick smoke pouring across New York City in the immediate aftermath of the 9/11 attacks. A quarter of a century later, the image is as haunting as ever.

On the morning of Sept. 11, 2001, members of the terrorist group al-Qaeda hijacked four passenger airliners and crashed two of them into the twin towers — a pair of 110-story skyscrapers at the heart of the World Trade Center in lower Manhattan. The impact of these collisions, which occurred roughly 17 minutes apart, eventually caused both buildings to collapse.

Shortly after the second tower was hit, the third hijacked plane crashed into the Pentagon, the headquarters of the Department of Defense in Arlington, Virginia. Another attack — likely intended for Washington, D.C. — was thwarted when the passengers of a fourth plane fought back against their hijackers, causing the aircraft to crash near Shanksville, Pennsylvania. In total, 2,977 people were killed across the different attacks, according to the 9/11 Memorial and Museum.

NASA astronaut and ISS commander Frank Culbertson — the only American not on Earth at the time of the attacks — passed over New York City shortly after being told about what was happening back home. He photographed the thick plume of smoke blowing away from Manhattan, at an altitude of roughly 250 miles (400 kilometers) above Earth's surface.

If you look closely, you may be able to see what Culbertson described as an "odd bloom" around the base of the column of smoke rising from the towers. This is likely a sign that the image was captured "around the time of, or shortly after, the collapse of the second tower," Culbertson said.

Culbertson wrote several letters in the days following the attacks, sharing his unique perspective of the events. "It's horrible to see smoke pouring from wounds in your own country from such a fantastic vantage point," Culbertson wrote on Sept. 13. "The dichotomy of being on a spacecraft dedicated to improving life on the earth and watching life being destroyed by such willful, terrible acts is jolting to the psyche."

While in space, Culbertson learned that the pilot of the plane that was later hijacked and crashed into the Pentagon was his former flight school classmate Charles "Chic" Burlingame. When the ISS later passed over the Pentagon, the astronauts could see the large gash in the side of the building where the third plane had crashed. "Tears don't flow the same in space," Culbertson wrote while discussing his friend.

In 2017, Culbertson revealed that there was another striking thing he and the rest of his crew noticed in the wake of the attacks, according to Live Science's sister site Space.com. "One of the most startling effects was that within about two orbits, all of the contrails that are normally crisscrossing the United States had disappeared because they had grounded all the airplanes," he said.

However, there was one exception. The astronauts noticed a single contrail moving eastward across the Midwest. "That was Air Force One headed back to D.C. with President Bush," Culbertson said. It was a "very sobering" sight, he added.

See more Earth from space

BERLIN — An eerily lifelike humanoid robot made by Chinese technology company Xpeng has now entered mass production, company representatives revealed. They say it'll be the first such machine to walk itself off the production line.

The humanoid robot, dubbed IRON, went viral last year after presenters sliced it open onstage to prove a human wasn't inside. Xpeng will now produce units through its existing production facilities, with no word on how many its factories will aim to build.

The fabric skin-clad machine comes in different body shapes and even genders, but all stand approximately 5 feet 7 inches tall (173 centimeters) and weigh 143 pounds (65 kilograms). The prototype included 82 degrees of freedom (DoF) head to toe, including 22 DoF in each hand, which differs from the production version's 76 DoF and 21 DoF respectively. They can also move at speeds of up to 6.5 feet per second (approximately 2 meters per second), which is equivalent to a fast power walk.

In conversations with Live Science at IFA 2026, held in Berlin between Sept. 4 and 8, Xpeng representatives claimed that their machines will one day be used in homes to help with domestic chores like cleaning and folding laundry. They likened the introduction of humanoid robots more generally to the rise of smartphones in the mid-2000s and expect robots to proliferate on a similar scale over the next few years.

As such, they have extremely lofty expectations for IRON, with the company branding it the world's first "high-level, general-purpose" humanoid robot. Representatives added that it can receive instructions, plan its strategy, navigate the environment intelligently, and avoid obstacles without trial and error. The robot also has a "self-charging" feature, meaning it will seek out designated charging cabins and plug itself in when low on battery.

The rise of humanoid robots

If the claims bear out, it will place IRON among the first such machines powered by artificial intelligence to be built on a massive scale. Competitors that have also entered mass production include American robotics company Figure AI's Figure 03, which in May participated in a live-streamed production line demonstration, as well as the Chinese AGIBOT, which reached 15,000 units in June.

One notable company that hasn't entered its robot into mass production is Tesla. The Optimus robot is still in factory assembly, and its release has been delayed four times since 2022, most recently last year. Xpeng representatives were keen to point this out in briefing materials shared with Live Science, without mentioning other humanoid robot makers.

IRON's makers claim it's more advanced than its counterparts. Rather than building separate AI engines, the company has deployed the same "world model" to power the robot as that used in its fleet of AI-enabled electric vehicles (EVs) and its flying car prototypes.

One of the biggest challenges in robotics is that, given the physical world's messiness, AI systems struggle to navigate and manipulate their environment unless conditions are controlled. That's why we're used to seeing robots either completing tasks slowly or getting things spectacularly wrong. Researchers, therefore, are increasingly focusing on building world models and other layers like improved vision-language-action (VLA) systems that enable them to better plan their actions a few steps ahead.

Xpeng representatives won't share detailed information about the proprietary AI system powering IRON, but each robot features three frameworks that combine so it can function autonomously.

The frameworks include VLA, which combines visual perception, natural language, and physical motor control; a vision-language model (VLM) — combining vision encoders with text readers; and a vision-language-task/thought (VLT) model, which representatives say gives IRON reasoning capabilities that enable it to think through assigned tasks.

Each IRON robot is powered by three Turing AI chips that offer a collective 2,250 trillion operations per second (TOPS) of AI processing power. This means it can run a model equivalent to Meta's Llama 3.2 (launched in 2024) locally without needing to access the internet. By contrast, most new laptops that can perform simple on-device AI tasks (like altering your webcam video feed in real time) tap into approximately 50 TOPS.

"We aim to build a new type of robot with full generalization capabilities that can truly become part of everyday life, create a better life for people, and ultimately become a companion in their lives," said He Xiaopeng, the company's chairman and CEO, in a statement shared with Live Science.

The company will first install these robots in its own showrooms and technology campuses while it continues to validate new ways to use them. Then in 2027, external shipments will target commercial customers for roles in areas such as customer service or guided tours in China primarily, and then in other countries.

When the United States and the Soviet Union signed the Outer Space Treaty in 1967, both nations agreed not to place nuclear weapons or other weapons of mass destruction in orbit around Earth. Specifically, Article IV of the treaty was designed to keep the Cold War's nuclear arms race from extending into space — a goal both superpowers shared.

The problem, then and now, is that neither side has ever had a reliable way to confirm that the other is keeping its word.

After nearly 60 years of uncertainty, a recent feasibility study from MIT physicist Areg Danagoulian proposes a possible solution: a satellite-based sensor that could search for the signature of nuclear material aboard another spacecraft, using high-energy protons trapped by Earth's magnetic field as a probe. The telltale sign of a warhead in space would be a large burst of neutrons scientists expect to be produced when these highly energetic protons interact with radioactive elements, like uranium, inside a warhead. A detector roughly the size of an encyclopedia and equipped with specialized sensors could identify neutrons emanating from the direction of a possible warhead from about 2.5 miles (4 kilometers) away after roughly a week of observation, according to the study's calculations. At closer range, the detection could come much faster.

The consequences of a space-based nuclear detonation are dire. But whether a detection system will prevent nuclear detonation in space will depend on several factors, some of which are technical but many of which are not, experts told Live Science.

What a nuclear blast does in space

On Earth, nuclear weapon tests leave telltale signals — like seismic waves, radioactive debris, and intense bursts of light and heat — that scientists have spent decades learning to detect. However, a warhead could be hidden inside an ordinary-looking satellite, potentially for decades, with nothing on the outside to give it away. If such a weapon were to detonate, it could jeopardize thousands of commercial, scientific and military satellites in a single blast, littering orbit with dangerous debris.

For most of the Outer Space Treaty's history, the missing verification mechanism has been a theoretical gap rather than an urgent one — in part because the world had already seen what a nuclear detonation in orbit does, and largely avoided repeating it.

The clearest example is Starfish Prime, one of a dozen high-altitude nuclear tests the U.S. ran between 1958 and 1962. On July 9, 1962, the U.S. detonated a 1.45-megaton warhead roughly 250 miles (400 km) above the Pacific.

The blast knocked out radio communications for hours, produced artificial auroras visible from Hawaii, and eventually damaged or destroyed eight of the 24 satellites in orbit at that time — including Telstar 1 and Britain's Ariel 1 satellite. Radiation from the blast lingered in orbit for about five years, leaving parts of near-Earth space hazardous for spacecraft. According to eyewitness accounts from the time, the radiation also knocked out roughly 300 streetlights in Honolulu and set off burglar alarms across Oahu.

The Soviet Union conducted its own series of high-altitude nuclear tests, known as Project K, in 1961 and 1962. Those explosions also produced damaging effects on the ground, including disruptions to power and communications in what is now Kazakhstan.

"It was one of the earliest instances where we began to have an understanding of the ways in which the space environment and the terrestrial environment are coupled together," John Barentine, an astronomer who has studied the environmental consequences of Cold War-era activities in space, told Live Science.

Diplomatic issues

Clearly, the impacts of a nuclear detonation in space are significant, and the new paper solves a long-standing problem by providing a way to detect weapons in space.

But is detection likely to work in practice? Getting a satellite close enough to observe another — and keeping it there for a week — would mean maintaining satellites closer than they ordinarily would be, experts say. That could raise suspicions about being spied on or attacked.

"Satellite operators get really freaked out," Thomas González Roberts, an assistant professor at the Georgia Institute of Technology who studies how space powers engage with outer space governance, told Live Science. "If another satellite is spending too much time next to you, you might think that they're spying on you."

Any such workable system would require the cooperation of the country whose satellite was being inspected, and that raises a separate set of questions about the international norms for when and how such inspections could take place, according to Brian Weeden, director of civil and commercial policy for the Center for Space Policy and Strategy at Aerospace Corp.

"In my experience, the policy problems are always the bigger challenge than the technical problems," Weeden told Live Science.

Solution in search of a problem?

There's also a question of whether this is a solution in search of a problem. Despite those early tests, deliberate nuclear damage to satellites has stayed rare for good reason, Roberts said. An attacker might have one target in mind, he said, but "you're going to take out more than just that target, and you have limited control over which satellites are affected."

That creates a strategic problem for any spacefaring nation: Any state capable of destroying other countries' satellites with a nuclear weapon "also has a relatively large fleet themselves," Roberts said — meaning the attacker would likely damage their own spacecraft, too.

"There's very few examples of nuclear damage in space because it's so obviously a bad idea," Roberts said. "These weapons are not really designed to be used, if you ask me."

The stakes are higher than ever

In theory, then, rational actors should shy away from launching or detonating nuclear weapons in space. No country has detonated a nuclear weapon in orbit since the 1960s, and it remains unclear how many, if any, nuclear weapons are currently stationed in space undetected.

But the possibility became harder to dismiss in 2024, when U.S. officials said they had evidence that Russia was developing a nuclear anti-satellite weapon — a claim Moscow has denied. The alleged spacecraft, based on media reports, is the Russian military radar satellite Kosmos-2553, which in 2022 launched into a radiation-heavy orbit that most other communication spacecraft avoid, Mallory Stewart of the U.S. State Department said in a 2024 interview. .

While Russia said the mission was meant for accelerated testing of how onboard electronics handle radiation, U.S. officials said the radiation level at that altitude was not high enough for such testing. The satellite was later observed tumbling and making erratic movements. This behavior raised suspicions that the spacecraft could be maneuvering toward a target satellite to detonate as a nuclear weapon, given Russia's "demonstrated willingness to target US and allied on-orbit objects," U.S. Space Command representatives said, according to a report from The Guardian.

The stakes are higher now than they were decades ago. All three experts interviewed for this story agreed that a space-based nuclear detonation today would be catastrophic — largely because of Earth's cluttered orbit. In 1962, 24 satellites, operated by two countries (the U.S. and the Soviet Union), were in orbit. According to a tracker maintained by astronomer Jonathan McDowell, more than 48,000 objects launched by more than 190 countries are tracked in space today; together, they support the communications, navigation, weather forecasting, Earth observation and military systems the world now runs on.

Even satellites that aren't in the blast radius could be damaged by a nuclear explosion in orbit. Modern satellites are built with off-the-shelf, low-cost electronics to keep pace with commercial demand, and they "are probably not hardened against the kinds of radiation you would get from a nuclear detonation of space," Weeden said. "I think that is the biggest concern."

A federal government study had found that a single high-altitude nuclear blast could raise radiation in low Earth orbit enough to disable nearly all unhardened satellites within weeks to months, with direct financial damages approaching $500 billion and the total economic impact potentially topping $3 trillion. The potential losses have only grown as the number of satellites has exploded and the world's dependence on them has increased. At the same time, declining launch costs have lowered the barrier to entry for spaceflight, opening orbit to nonstate actors without sizable satellite fleets of their own. That dynamic makes it more attractive for such actors to exploit major powers' deep economic and military reliance on space, Roberts said.

"It's most attractive for a rogue state like North Korea," he added. "It's not attractive for a spacefaring state like Russia. Doesn't mean they won't do it; it's just that there's enormous amounts of cons to that type of attack."

Ultimately, whether space-based nuclear weapon detection methods like those proposed by the MIT study wind up being useful is a policy question, Weeden said.

Implementing such a detection system "would raise a whole bunch of new discussions about on-orbit inspections and what are the international norms around that," Weeden said.

When archaeologists with the National Museum of Denmark excavated a burial mound called Guldhøj (Gold Hill) in southern Jutland in 1891, they were surprised to find a well-preserved wooden folding chair similar to those known from ancient Egypt and Greece. But the Guldhøj folding chair was made in Denmark around 3,400 years ago and is the only completely preserved chair from the Bronze Age in Europe, according to the National Museum of Denmark.

The chair was discovered in the grave of a chieftain, who was buried in a hollowed-out oak tree trunk and wrapped in a cowhide. The man had been dressed in a wool cloak secured with a bronze brooch, two wool hats, woolen mittens and leather shoes. Among the offerings his loved ones left in the grave were a bronze ax and a bronze dagger, along with two ornate wooden bowls and a wooden box. But the folding chair was an unusual addition to the grave and was likely a marker of the man's extremely high status.

The frame of the Guldhøj folding chair was crafted from ash wood, while the seat was made from otter skin, only a fragment of which was preserved over the millennia. Patterns incised into the top of the wooden frame were inlaid with a black, tar-like substance to create a band of geometric decoration.

In a 1999 study led by archaeologist Kirsten Prangsgaard, researchers who examined the chair determined that it was made from two frames of wood, each about 13 inches (33 centimeters) tall. When the frames were put together at a 45-degree angle, the low chair or stool would have been around 9.5 inches (24 cm) off the ground. Originally, the chair frame was likely held together with bronze nails, which may have been removed before the seat was placed in the grave, according to the researchers.

Folding chairs may seem simple, but they were important pieces of furniture that signified the seated person was of high rank, and they were likely used in rituals or ceremonies, according to the National Museum of Denmark.

Archaeologists have found ancient folding chairs in this style in Bronze Age Egypt and Greece, where weather conditions are better for preserving organic material such as wood. The Guldhøj folding chair is not unique in Nordic countries; pieces of chairs have been found in other chieftain graves in Denmark and northern Germany, and a rare metal folding chair was even found in an early medieval woman's grave in Germany. However, it is the only completely preserved wooden folding chair from Bronze Age Europe, Prangsgaard and colleagues noted in the study. "The folding chairs thus seem to belong to the warrior graves of the Early Bronze Age," they wrote.

The similarity of the Guldhøj chair, which was made in Denmark, to chairs found in far-flung civilizations means that Bronze Age people were exchanging ideas through trade and gift giving, the researchers wrote. The chairs show a clear artistic connection between Bronze Age Nordic and Mediterranean groups. Another connection is the four-spoked wheel on the famous Sun Chariot from Trundholm, which mimics designs seen in the Aegean region.

Both the unusual folding chair and the wooden bowls buried with the Bronze Age chieftain in the Guldhøj mound "can only be described as rare objects of high prestige," according to the National Museum of Denmark.

For more stunning archaeological discoveries, check out our Astonishing Artifacts archives.

Can you put together last week's Astonishing Artifact?

Archaeologists in Egypt have discovered an ancient tomb belonging to the "keeper of the secrets of royal decrees," they announced following an excavation at Saqqara.

The decorated burial belongs to an official named Sekhentio-Ptah, who lived during the Old Kingdom (2649 to 2150 B.C.), a period that's famous for the building of the pyramids, including those at Giza.

While the title "keeper of the secrets of royal decrees" may sound mysterious, it was likely a more bureaucratic position, said Ann Macy Roth, a clinical professor of Egyptology at New York University who was not involved with the excavation.

It "probably merely means that as someone in charge of royal documents and the people who write them, he has access to confidential information," Roth told Live Science in an email. "It's a common title among royal scribes."

The official Sekhentio-Ptah had a number of other titles, according to his tomb, including "Overseer of all the King's Works" and "Overseer of Royal Documents," representatives of Egypt's Ministry of Tourism and Antiquities wrote in a translated statement.

Within the tomb, archaeologists found an offering table, a purification basin and two false doors. The false door is a symbolic door, commonly found in ancient Egyptian tombs, that was believed to allow the soul to exit and enter the tomb at will. The design of the false doors places them in the late fifth or early sixth dynasty, around 4,350 years ago, Roth said.

More than 100 shabtis (also spelled ushabtis) were found in the tomb. Ancient Egyptians believed these figurines would act as servants for the deceased in the afterlife. The team also discovered a wooden statue of a falcon (possibly related to the falcon-headed god Horus) and the remains of cartonnage, a plastered material used on mummies. The mummy of Sekhentio-Ptah was not identified.

Looking at the photos and information the ministry released, Roth said it's likely this tomb was reused for later burials ‪—‬ something that was commonly done in ancient Egypt. She said the shabtis found in the tomb likely belong to later burials and the cartonnage is likely from mummies that were buried in the tomb at a later date.

The team discovered the tomb in the Bubasteion (also spelled Bubasteum) area of Saqqara, a place that was commonly used for cat burials in later times such as the late period (circa 664 to 332 B.C). The site was associated with Bastet, a cat-shaped goddess associated with fertility and protection. However, the statement didn't mention any cat burials found in this particular tomb.

Live Science reached out to the excavation team but did not hear back by the time of publication.

See how much you know about mummies with our mummy quiz.

"Protect our water," "Water for people not AI," "Don't mess with our water," declare protest signs from Texas to New Mexico to Arizona. Angered by water use, energy consumption and pollution, locals are increasingly protesting the rapid expansion of data centers in the United States as tech companies work to rapidly expand capacity for AI.

Many data centers rely at least partly on water to absorb heat from air or surfaces, and then cause cooling as it evaporates, just like sweating keeps our bodies cool. The processors inside data centers can reach internal temperatures of up to 176 degrees Fahrenheit, for the same reasons that an overtaxed laptop heats up.

But while there's little doubt that data centers are consuming significant amounts of energy, water consumption is more complicated. Claims circulating online bring scant clarity, ranging from articles claiming that chatbots can consume 500 ml of water per query to some online commentators declaring AI's water issue to be nonexistent. And the consumption data from large tech companies themselves are often incomplete and inconsistent.

Experts stress that, overall, data center water consumption pales in comparison to the usage by industries like agriculture and some kinds of manufacturing. Researchers have estimated that data center cooling systems consumed 66 billion liters of water in 2023, less than 1 percent of the nation’s total consumption.

That figure could considerably rise with the rapid buildout of AI data centers, however — which may not be a big problem for water-rich regions but could significantly add to local water stress in drought-strapped places like New Mexico and Arizona.

Fortunately, engineers say there's a host of things that can be done — and are being done — to reduce the strain on local water resources. "There are many good ideas out there," says energy systems expert Fengqi You of Cornell University. When you add in efforts to replenish and restore natural water resources, "there's a good chance that, eventually, it could be net-zero water for the on-site cooling."

More renewable energy and better siting

Recent advances in AI technology have already reduced water demand for many data centers. Electrical and computer engineer Shaolei Ren of the University of California, Riverside, says that an estimate he made based on GPT-4, an earlier version of the model powering ChatGPT, as recently as 2024 — that drafting a short email would consume 500 milliliters of water — is already outdated because AI models have become more efficient. (This study was the origin of the half-liter-per-query claim.) In 2025, Google estimated that five drops of water are spent on processing a median-length query with its chatbot Gemini.

But even tiny amounts add up, given the rise in AI use. You's group recently predicted that by 2030, US data centers could consume 731 billion to 1,125 billion liters annually — the latter roughly equivalent to New York City's annual drinking water supply.

Still, these numbers factor in not just cooling, but also a greater amount of water used to generate the electricity that powers data centers. Much of that comes from burning coal or gas, with water being used to cool steam back into liquid after it's been used to spin the electricity-generating turbines. In other words, AI's water consumption can be significantly reduced by shifting to solar and wind, which require little to no water to operate, You says.

You adds that companies should site data centers in areas less prone to drought and with ample renewable energy sources, like regions in Montana, Nebraska, parts of Texas and South Dakota, instead of constructing new data centers in water-stressed places, such as in Arizona, New Mexico and Southern California. Strategic siting along with other measures could reduce AI's future water footprint by up to 86 percent, he says.

New cooling technologies

Advances in cooling technologies are also helping. The newest data centers that specialize in AI are already more water-efficient than their predecessors.

Pre-AI data centers use fans to carry away the heat from processor-filled racks, then use chilling systems funneling cool water through the building to cool the warm air down again. The heated water is then fed into a cooling tower that removes the heat but also loses some of the water to the atmosphere. This evaporative cooling uses a lot of water, says Eric Masanet of the University of California, Santa Barbara, who researches data center sustainability.

But the energy-hungry processors inside AI data centers generate so much heat that it's hard to remove it with air alone. That’s why many tech companies — including Amazon, Microsoft and Google — use a more efficient technique called liquid cooling.

In this method, a system of pipes filled with water, sometimes mixed with temperature-regulating chemicals, runs on top of the hardware, cooling the processors directly rather than cooling the entire data center. And because this is a closed-loop system, no water is lost: The heated fluid can be cooled down by exposing the pipes to the outside air, if conditions are cool enough, or an air-conditioner-like system, which uses energy.

But when it's extremely hot or humid, the centers need to bring online extra, more effective methods that involve water; one of these is to mist the air around the pipes. Mechanical engineer Vaibhav Bahadur at the University of Texas at Austin says that most AI data centers in Texas only use this kind of water-based cooling for the hottest parts of the summer.

Still, he and his colleagues recently estimated that the state's growing number of data centers — which currently consume less than a percent of the state's water demand — could be using 3 to 9 percent of that water by 2040. He expects that figure to reduce considerably, though. "Data centers are becoming much more efficient in their water usage," he says.

Indeed, recent technological developments have made it easier to avoid water-based cooling, even in hot climates, says Josh Parker, head of sustainability for NVIDIA, the company that designs many of the processors that populate AI-specialized data centers. Their latest generation of processors run at such high temperatures that they can be cooled with water at around 113 degrees Fahrenheit which, Parker says, is significantly warmer than traditional approaches. That reduces the need to bring on water-based cooling. Unless local temperatures regularly exceed 113 Fahrenheit, a threshold generally crossed only during severe heat waves, "typically we can just get away with large efficient fans cooling the infrastructure and the ambient air is sufficient to pull the heat away," Parker says.

Ren cautions that some companies may not want to run their processors that hot because it can interfere with computational performance, while some also house non-AI servers in the same space that cannot take the heat. But other cooling technologies are in development.

Some of these rely on elaborately designed pipe systems that draw heat even more effectively from processors. A number of US companies are exploring immersion cooling, where data center hardware sits in a tank filled with cooling liquid. In China, some companies have taken a similar approach by installing data centers in the ocean, although this makes them hard to access should hardware need replacing or upgrading, Bahadur says.

Advances in cooling technology will be necessary for tech companies to meet sustainability goals they have set for their operations. According to a statement from Amazon, its Web Services "set a goal to be water positive by 2030 — returning more water to communities than our direct operations use — and as of 2024, we're more than halfway there."

A spokesperson for OpenAI points to a web page outlining the company's plans to minimize water use, while Google aims to replenish 120 percent of the freshwater its data centers consume by 2030 through a variety of water stewardship projects.

Some companies, such as Google, are also finding smart ways to use waste heat from data centers to help address other sustainability challenges, such as making building heating less reliant on fossil fuels. Across Europe, some data centers are funneling heat from cooling circuits into district heating systems used to warm buildings.

The future of AI's water usage hinges on decisions that tech companies, engineers and policymakers will make in the coming years, Masanet says: where data centers are sited, their local energy infrastructure and climate, and how they're designed. "If you choose one set of choices, your number is going to be off the charts," he says. "You choose another set of choices, it's going to be way down here."

This article originally appeared in Knowable Magazine, a nonprofit publication dedicated to making scientific knowledge accessible to all. Sign up for Knowable Magazine’s newsletter.

Nearly two millennia ago, a wealthy Roman commissioned an intricate, multicolored floor mosaic that depicted two beloved household animals: a cat named Emerald and a dog named Ocean. The mosaic was a key feature of a villa, which archaeologists recently unearthed from beneath the ancient city of Adramytteion on Turkey's Aegean coast.

Within the Roman villa, which has been dated to the late second to third centuries A.D., archaeologists discovered three halls surrounding a central atrium. In one room, which likely functioned as the villa's main reception hall, archaeologists found a colorful mosaic with 15 separate panels depicting living and mythological creatures.

In a study forthcoming in the Journal of Mosaic Research, archaeologist Hüseyin Özgen, head of the Adramytteion research team at Mimar Sinan Fine Arts University, wrote that the 15 panels are centered around what appears to be a depiction of Medusa, while the named cat and dog may preserve the memory of household creatures.

Özgen began excavating at Adramytteion in 2012, but he and his team discovered the Roman villa only recently and excavated it in 2025 and early 2026. In the Roman period, Adramytteion was a provincial capital within Asia Minor and a prime trading spot due to its location at the head of a gulf on the Aegean Sea. The impressive villa included three mosaic-paved halls, a number of secondary rooms, and a network of pipes and drains that may have connected to a latrine.

Visitors approaching from the courtyard of the villa would have been greeted by the largest, most elaborate mosaic in the residence, according to Özgen. Located in the middle of the room, the mosaic measures about 16.4 by 11.8 feet (5 by 3.6 meters) and contains 15 panels arranged in three rows. Most of the panels depict birds, fish and felines, but two mythologically inspired panels include a gorgon (possibly Medusa) and a winged horse (possibly Pegasus). Ancient artists used white, black, red, orange, yellow, pink, burgundy, blue, turquoise and green tiles to create the intricate design.

Only two of the animals depicted in the mosaic are named. As someone entered the room, the first mosaic panel they would have seen to their left was a pale cat seated on a blue-green cushion, Özgen wrote in the study. Above the cat are the Greek letters ΖΜΑΡΑΓΔΙΝ (Zmaragdin), meaning emerald. The relaxed cat sitting on a cushion suggests that Emerald may have been a pet rather than a stray.

One possible explanation for Emerald's name may be a link to the desert of Roman Egypt, where emeralds were mined in antiquity; the villa owner may have been a merchant with North African connections.

On the right side as someone entered the room was a mosaic panel depicting a running or leaping dog. This animal is labeled with the Greek letters ΩΚΕΑΝΟΣ (Okeanos), meaning ocean. Adramytteion was a harbor city, so Ocean's name may have been bestowed due to his surroundings, according to Özgen.

Emerald and Ocean were likely familiar to the villa's residents, even if they weren't specifically pets, Özgen wrote, and their depictions in the mosaic may have functioned as familiar signs of ownership and household identity.

Research at Adramytteion by Özgen and the project team is ongoing.

From Augustus to Nero, see how much you know about ancient Rome's famous leaders with our Roman emperor quiz!

Scientists in Japan have built a new transistor that can withstand temperatures of 1,110 degrees Fahrenheit (600 degrees Celsius). Components this robust could one day be used in surface probes on Venus — where the thick carbon dioxide atmosphere can reach temperatures of 860 F (460 C).

Most modern tech, including instruments used for deep-space exploration, uses transistors to control the flow of current. But the new device is a type of junction field-effect transistor (JFET), where the strength of an electrical field changes the channel’s conductivity.

JFETs are typically used in specialist applications because they are more difficult to scale down than the more common metal-oxide-semiconductor field-effect transistors (MOSFETs), which are widely used in consumer smartphones and computers. But JFETs can offer lower noise levels because their operation does not rely on an oxide layer, which can introduce interference.

The researchers outlined how the new transistor works in a study published Aug. 17 in the journal APL Electronic Devices.

Can't take the heat

Since at least the start of the century, silicon carbide (SiC) JFETs have been considered a promising option for low-power integrated circuits heading for Venus due to the material's inherent ability to withstand high temperatures.

As the scientists pointed out in the new study: "Past landers have been limited to only a few hours by silicon-based electronics." Venera 13, a Soviet-era lander, holds the world record for the longest time survived on Venus by a spacecraft, at 2 hours, 7 minutes.

"Integrated circuits (ICs) fabricated with SiC are particularly attractive for extreme environments, such as deep-space exploration, geothermal drilling, and aerospace engine control, where conventional silicon-based ICs cannot operate reliably," the researchers added.

But recently developed SiC-JFETs have all met the same two problems: low controllability and large leakage currents. The former is linked to how the SiC substrate is doped with other atoms to alter its electrical properties, defining its gate (where the electrical field is created) and channel (where the current flows) regions.

In a material with a regular crystal structure, like SiC, some dopant atoms may penetrate deeper than expected. This doesn't matter under normal conditions, but when exposed to high temperatures, it causes variations in the field voltage required to open the channel and makes the transistor harder to control reliably. The scientists found that it can throw conventional JFET voltage thresholds off by over 2 volts.

Furthermore, at temperatures above 660 F (350 C), the SiC substrate can become less electrically resistive, allowing current to flow even when the transistor is switched off. This makes it harder for the JFET to control current properly, potentially causing incorrect signals and increased power consumption.

Even the highest-performing JFETs can only operate long-term at 930 F (500 C), but the Kyoto team had a theory as to why these challenges remained unresolved.

"We believe the lack of development is because the research community has been trying to apply silicon-era thinking to a fundamentally different material," said first author of the study Mitsuaki Kaneko, associate professor of engineering at Kyoto University, in a statement.

Turning the transistor on its head

The researchers designed their new SiC-JFET with these two challenges in mind. To improve controllability, they implemented a bottom-gate structure, where the gate is positioned underneath the SiC conducting channel.

Its gate region is heavily doped by design, so when dopant atoms in the channel penetrate deeper into the SiC, it doesn't change the overall doping profile of the channel-gate region, limiting its impact on the threshold voltage even at high temperatures.

The team also used dopants to create two semiconductor regions, or "wells", in the SiC around the JFET. The boundaries between the wells act as barriers to current flow, meaning that even when the SiC becomes more conductive at high temperatures, current cannot bypass the channel when the transistor is switched off.

Researchers measured how well the new JFET could switch current on and off and how closely the actual threshold voltage matched the theoretical value, based on its thickness and level of doping. They recorded these metrics at temperatures ranging from room temperature to 1,110 F (600 C).

"The fabricated devices demonstrated stable, normal transistor operation at temperatures over 873 K [1,110°F], opening up possibilities for ultrahigh-temperature SiC devices," they wrote in the study. Furthermore, at about 750 F (400 C), the threshold-voltage error was found to be less than 0.1 V thanks to the bottom-gate design.

As well as surface probes on Venus, the transistor could be useful inside jet engines, the scientists said. Currently, components connected to gas turbines must be protected from extreme temperatures using thermal shielding, long wires and energy-intensive cooling systems, restricting engine design.

Before it can be launched into space or hooked up to a plane, the team still needs to test and optimise the transistor for practical use. This includes integrating it into more complex circuits, scaling it up to wafer-level and ensuring that the entire circuit package will withstand extreme temperatures and pressures.

Indeed, it may not be too lofty a goal. NASA demonstrated that integrated circuits with SiC-JFETs could withstand temperatures of 860 F (460 C) and 9.3 MPa of pressure for 60 days, and 930°F (500 C) in the air for over a year. Plus, in 2024, a team from the National Institute for Materials Science in Japan developed a MOSFET out of diamond that could operate above 570 F (300 C).

It looks like a gigantic treasure chest left open among the stars — but instead of gold and jewels, this strange cosmic structure contains dozens of newborn suns. This new image from the James Webb Space Telescope (JWST) reveals the aptly named Treasure Chest, a colorful cloud of gas and dust in the Carina Nebula, one of the Milky Way's richest star-forming regions.

Located about 7,500 light-years away in the Southern Hemisphere constellation Carina, the nebula stretches roughly 260 light-years across and contains some of the most massive stars in our galaxy, as well as tens of thousands of young protostars. It's also home to the "Cosmic Cliffs," which appeared in JWST's first collection of science images, released in 2022.

The Treasure Chest is a cometary globule, an isolated cloud with a dense, dark head and a sweeping tail. Although such objects are named for their resemblance to comets, this one looks more like a wooden chest with its lid propped open and light spilling from inside.

JWST's Near-Infrared Camera reveals the source of that glow: a compact cluster of about 70 young stars embedded in the dust. The most massive one is a rare O-type star — extremely large, bright, and short-lived stars — measuring roughly 19 times as massive as the sun.

Astronomers estimate that the cluster is around 1.3 million years old, although earlier estimates suggested it could be as young as 100,000 years. Many of its stars are still surrounded by the gas and dust from which they were born. Over time, radiation from the cluster's stars will disperse that material, exposing stars that are currently hidden.

The Treasure Chest's unusual shape is also influenced by something outside the JWST image. About 39 light-years away, as measured across the sky, is Eta Carinae, the most luminous object in the Carina Nebula. Eta Carinae famously underwent its "Great Eruption" in the 19th century, when it briefly became one of the brightest stars in Earth's night sky. The system contains at least two stars, including one about 100 times as massive as the sun and roughly 5 million times as luminous. Together with the nearby Trumpler 16 star cluster, its intense radiation and stellar winds are blasting away the Treasure Chest's less-dense gas and helping to sculpt the cloud into its distinctive shape.

The Treasure Chest won't always look like this. Radiation and winds from the young stars inside it, combined with the assault from massive stars nearby, will gradually erode the remaining gas and dust. Eventually, the cosmic chest will disappear, revealing its true jewels — the stars within it.

For decades, engineers have been working to create smaller and smaller transistors to fit ever-larger numbers of them onto computer chips, all in the name of greater processing power. Now, in the age of artificial intelligence (AI), that effort has turned into an all-out race.

So how small can a transistor actually get? And is smaller even still the goal?

To understand the answer, first you need to know what a transistor is.

"If you take a computer or your mobile phone and you were to pry it open, you will see that there is a printed circuit board," Suman Datta, a professor of electrical and computer engineering at Georgia Tech, told Live Science.

On that circuit board are small, rectangular objects called chips, and inside each chip is a tiny piece of silicon. "And in that silicon, if you zoom in like a million times … maybe, if you're lucky, you will start seeing these tiny switches or transistors sitting etched into that piece of silicon," Datta said.

Each transistor is effectively a switch that turns on and off in response to jolts of electricity pulsing 4 billion times per second. Modern devices contain billions of transistors, and each one turning on and off in a precise orchestration to move and store 1s and 0s powers everything from Google searches and AI data centers to the device you're using to read these words.

The smaller the transistors are, the more can fit on each chip and the greater the chip's speed and functionality. So how small have they gotten so far?

"Researchers have built proof-of-concept devices in which a single atom controls the flow of electrons, although the rest of the device is still much larger," Anton Persson, an assistant professor at Chalmers University of Technology in Sweden, and Tara Peña, an incoming assistant professor at UCLA, told Live Science via a jointly written email. That means the switching part of a transistor has been made at the smallest scale physically possible, even though a complete device that small doesn't exist yet. New materials and approaches could make these devices even smaller. In a study published in June in the journal Nature Nanotechnology, Persson, Peña and colleagues used two-dimensional semiconductors made of tungsten disulfide, among other materials, to shrink nanoribbon transistors down to a channel width of 25 nanometers ‪—‬ about 0.00025 the width of a human hair.

Two-dimensional semiconductors are electrically active materials that are only one or a few atoms thick, and because electrical current can be controlled more precisely in such a thin layer, they allow for smaller transistors than traditional silicon does.

Over the next decade, they still expect silicon transistors to shrink, but more slowly than they did in the past, they said. "To go considerably smaller, we may eventually need to move beyond silicon to atomically thin materials, such as the two-dimensional semiconductors we study."

A host of considerations

Size isn't the only consideration; cost is important, too. It's enormously expensive up front to design and build a new chip. "We are as R&D-intensive as drug companies that spend billions of dollars developing one drug," Datta said. "It's a very similar business model."

There are also manufacturing factors to consider. "The often much harder step is producing billions of those transistors reliably, at scale and at a price that makes sense commercially," Persson and Peña said. "Something that works once in a laboratory does not necessarily work in a factory."

Another consideration is energy efficiency. "If I'm adding more and more transistors onto that little piece of silicon, and at the individual transistor level, they don't become more energy efficient … then when I go from, let's say, 10 transistors to 20 transistors, my power budget has to be doubled, all things being equal," Datta said.

For example, the latest Nvidia data center GPUs consume 1.4 kilowatts of electricity, and Nvidia's upcoming release is estimated to consume nearly a kilowatt more than that. Half of that is given up as waste heat, Datta said.

"So it's not just smaller, faster, cheaper, but also more energy efficient," Datta said. "You have to work on all the four vectors."

Is smaller still the goal in the age of AI?

Still, there is a limit to the physical space available for additional transistors, which is why engineers are turning to 3D designs — think taller instead of smaller.

"Instead of only making each transistor smaller, the idea is increasingly to stack transistors on top of one another so that more of them fit within the same chip area," Persson and Peña said. "That way, we can still make our electronics considerably more powerful, even if each transistor shrinks only modestly."

The quest for faster, more efficient chips is only getting more urgent with the explosive growth of AI. But smaller transistors and more powerful chips aren't just important for AI data centers; they also mean smaller, potentially cheaper consumer electronics.

"People certainly notice the consequences of smaller transistors," Persson and Peña said. "They can use less power and allow more computing power to fit on the same chip. That can mean faster electronics, longer battery life and lower costs. Historically, that combination has enabled today's smartphones to outperform room-sized supercomputers from decades ago."

So how small can transistors get? "We will do everything to make it as small as possible as long as we can control the physics," Datta said. "And as long as we can, we will find a way to make the economics work."

Over dinner at a gaming convention around 2010, board game designer James Ernest turned to his friend Eric Harshbarger and asked a question: Could you design a set of dice so that each player in a group — whether two people or any number — could grab one, roll and have a perfectly equal shot at going first? The rule is simple: Roll your dice, and whoever lands the highest number goes first. The hard part is making that outcome truly fair for every player, no matter how many are at the table.

There could be no ties and no rerolls.

Harshbarger, a mathematician at Auburn University in Alabama, didn't have an answer that night. But the question stuck. Over the next 15 years, he and a loose network of collaborators casually worked to crack what became known as the "go first dice" problem.

Now, they finally have the answer: a set of five 60-sided dice, collectively engraved with every number between 1 and 300, with no repeats. To mark the achievement, Harshbarger built five giant, wooden replicas of these hexecontahedrons (60-sided 3D shapes), each carved from a different type of wood. They are now on permanent display in Auburn's new mathematics building.

The problem with dice

To understand why it was so hard to crack the problem, it helps to understand the simple part.

"The easy thing is to avoid ties; you just put different numbers on all the dice," Harshbarger told Live Science. "The problem comes in how you distribute those different numbers across the dice so that the probability is equal not only for the whole set but for any subset."

That second condition is what makes the problem devilish. Ernest's request wasn't just that eight players could roll fairly; it was that any subset of players could grab any dice from the bag roll and still have equal odds. If five people are playing, each takes a die. Three people? Same thing. The numbers on each die had to be arranged so that the fairness held no matter how many people showed up to play.

Harshbarger looped in his childhood friend Robert Ford, a mathematician at Dalton State College. Within weeks, they had a three-player solution: numbers 1 through 18, spread across three standard six-sided dice in exactly the right arrangement. Four 12-sided dice, Ford later worked out entirely by hand, could accommodate four players fairly.

By 2012, Harshbarger was giving talks about the four-player set at math conferences, and The Guardian covered the story. His inbox erupted. He started selling handmade sets from home — buying blank, 12-sided dice; etching numbers onto each face with a laser cutter in his workshop; and then inking every number by hand. At his peak, he was dropping off 30 envelopes at the post office at a time, several times a week, shipping sets to customers around the world.

But as the team dug deeper into the math, they discovered that the dice were doing something even more remarkable than they'd realized: The configurations determined not only who went first but also the entire turn order, with every possible sequence of players equally likely to come up.

"If four people rolled, the chance that players finished in the order A, B, C, D was just as likely as C, B, D, A, or any of those combinations," Harshbarger said. "'Go first dice' is actually a bit of a misnomer, because they do much more than just determine who goes first; they actually determine the ordering of all the players."

This property, which the team calls permutation fairness, became the standard they chased for every set of dice from that point on.

More combinations than atoms in the universe

Four players was one thing. Five was another entirely.

Mathematically, the team knew a five-player same-shape set was feasible. But finding it meant searching an incomprehensibly large space of possible number arrangements.

"We're talking literally more than the number of atoms in the universe ‪—‬ like 10 to the 128th power combinations," Harshbarger said. "There's just no way, even if we had a billion billion years and all the computers, all the AI. We still couldn't do it today."

They couldn't brute-force their way to an answer. They needed mathematical shortcuts: symmetries and patterns to shrink the search space. But even then, years passed without a practical solution. Every path they found hit the same wall: dice too large to hold, too many sides to manufacture.

"My goal was a set for five players that can actually be manufactured, that you can hold in your hand, that board gamers could buy and roll," Harshbarger said. "Even for a problem that is silly and pointless as far as gameplay — just mathematically, can you buy these things and roll them, and they work? You can't do that with 180-sided dice."

Then, in mid-2023, Canadian software engineer Paul Meyer emailed Harshbarger out of the blue. He had been studying patterns in Harshbarger's four-player data and had written a program to exploit them. He hadn't expected it to work right away.

It did. Meyer found a configuration of five 60-sided dice that satisfied every condition.

"I double-checked his work and went, 'Oh my goodness; we've been searching for so long for this. This is amazing,'" Harshbarger said.

From workshop to gallery wall

The four-player set had long since been picked up by retailers — Maths Gear in the U.K. and Math Art Fun in the U.S. — so Harshbarger had stopped hand-making those years earlier. Now, the five-player version was real and small enough to manufacture.

But the story had one more turn. Auburn University was building a new home for its mathematics department and was looking for sculptural ideas to fill it. Harshbarger proposed building giant versions of the five new dice out of wood. The department agreed.

He spent months in his wood shop, constructing five oversize dice. Each is from a different type of wood: pine, poplar, oak, walnut or mahogany. The five sculptures now stand in Auburn's new math building, which opened this fall.

For Harshbarger, the whole point is making math impossible to walk past.

"When people see giant dice or little dice, they're fascinated just by the geometry," he said. "The hope is, they see these things and go, 'Oh, this is math too, and this is interesting.' Some of the most fun math problems are ones that are easily understood and not easily answered."

Humanoid robots in Beijing have beaten a number of men's athletics world records at the 2026 World Humanoid Robot Games, claiming high-water marks in the 100-meter sprint, the 400 m, 1,500 m and high jump. While these performances aren't official replacements for the human records, as the robots competed under robot-specific categories and conditions, they highlight the progress made since last year's inaugural robot games .

The five-day games were held between Aug. 22nd and 26 at Beijing’s National Speed Skating Oval and drew 2,056 robots from 666 teams across 16 countries. The events included sports like football and martial arts, as well as practical applications like warehouse logistics, factory-style assembly and charging tasks.

Robots broke four human athletics records:

100 meters: Tiangong Ultra, 8.64 seconds

Human benchmark: Usain Bolt ran 9.58 seconds at the 2009 World Athletics Championships in Berlin.

Robot result: Tiangong Ultra is a humanoid robot developed by the Beijing Humanoid Robot Innovation Center. It won the large-size 100 m final, completing it in 8.64 seconds on Aug. 26. It set an early mark of 9.39 seconds, already enough to smash Bolt's record, then improved to 8.86 seconds in qualifying before the blistering 8.64 time in the final. That 8.64-second time is 0.94 seconds below Bolt’s mark.

400 meters: Tiangong Ultra, 38.15 seconds

Human benchmark: Wayde van Niekerk's 43.03 seconds, set at the Rio Olympics on Aug. 14, 2016.

Robot result: The same robot that set the 100 m record dominated the 400 m competition as well. Tiangong Ultra won the 400 m final in 38.15 seconds, nearly 5 seconds faster than van Niekerk's world record.

1,500 meters: Tiangong Ultra, 2 minutes, 21.6 seconds

Human benchmark: Hicham El Guerrouj of Morocco set the men’s 1,500 m world record of 3 minutes, 26 seconds in Rome on July 14, 1998.

Robot result: Team Tianzhuo's Tiangong Ultra completed its record-smashing hat trick, winning the 1,500 m in 2 minutes, 21.6 seconds — well below El Guerrouj's time. The next two finishers, at 2 minutes, 30.00 seconds and 2 minutes, 30.22 seconds, also bettered the human benchmark.

High jump: 2.88 m (9.45 feet) standing jump

Human benchmark: Javier Sotomayor of Cuba cleared 2.45 m (8.04 feet) in Salamanca, Spain, on July 27, 1993.

Robot result: A robot made by X-Humanoid cleared 2.88 m in a standing high jump, which smashed the previous best robot result of 0.95 m (3.12 feet) at the inaugural games in 2025. However, Sotomayor’s record came in a standard running high jump, in which athletes use a curved approach, generate speed and clear the bar using a technique called the Fosbury flop. The robot completed a standing high jump, a different event with different mechanics. The running high jump is both harder and higher than the standing jump, because athletes can convert horizontal speed into greater lift using a one-foot takeoff and the Fosbury flop, enabling higher clearances than the purely muscular, two-footed standing high jump.

What the record claims mean

These games showcase the expanding abilities of humanoid robots. Disciplines like running, particularly across longer distance events like the 1500 m, and high standing jumps require powerful actuators, fast balance corrections, foot-placement control and software that can compensate for tiny errors in real time.

"In my view, these World Records were achieved using, 'The Best Part is No Part' principle, through mostly mechanical optimization to perform a single task extremely well," said Scott Walter, the Robotics Research Diligence director at RoboStrategy, an investment fund that gives retail and institutional investors exposure to private and public companies in robotics and “embodied” or physical AI. "Locomotion is mostly solved as witnessed by these games, albeit with optimizations," he told Live Science in an email.

Walter said the key to many of the impressive advances we've seen is simplicity, shearing off unnecessary components that introduce more points of failure and can make coordination more difficult.

"Many degrees of freedom were removed in the arms (shoulders, elbow, no wrist, no hands), hips and ankles. This reduced mass, and allowed distal mass to be moved higher up in the kinematic chain, improving movement efficiency," he said.

However, although the robots were very capable in the specific events in which they competed, we shouldn't take that to mean they're top performers in other, more diverse tasks.

"The bots are barely humanoid and could only accelerate in a straight line, not stop without crashing nor run the curve to slow down," Walter said. "The winners were in no shape afterwards to stand on the podium to receive their medals. Nor could they run in the 4x100 relay as, ironically, they had no hands for the 'hand-off.'"

Some robots were seen crashing into barriers or falling, and others caught fire, highlighting that reliability is still an issue.

But other robots at the games were made for more than just going faster, higher, stronger. Alongside track-style events, robots performed practical tasks such as connecting charging cables, handling objects, using tools and working in simulated industrial or service settings.

In many cases, the greater challenge is not raw strength or speed but reliably seeing an object, judging its position, applying the right amount of force and recovering when something does not go as planned. More than 40% of the games' events required robots to operate autonomously, without direct human control.

"Manipulation is the greatest biggest challenge as that is the business end of the humanoid and a dexterous and robust hand is still elusive," Walter said. "Specialization is easy, general purpose is not."

Walter noted that the decathlon record may be the next target as it demonstrates a range of abilities.

"The human Decathlon record is the true test of speed, endurance, power, strength, robustness, coordination and dexterity. I would not be surprised to see an attempt at the record next year," he said.

Archaeologists were excavating in a Roman-period cemetery in Poland when they came across something extremely unusual: the grave of a man who was buried with two decapitated human heads, a necklace made from 42 mammal teeth, and a battle ax. That ax provided an important clue: He was actually from the Stone Age, three millennia older than the Roman cemetery.

"We were practically packing up, and then we discovered a circular shape in the ground and began digging," Paweł Dąbrowski, a biological anthropologist at Wrocław Medical University, said in a Sept. 2 translated statement. "We found fairly well-preserved animal teeth arranged in a necklace."

The grave, which was found near Wrocław in southwest Poland, included the nearly complete skeleton of an adult male who was buried with amber beads, a flint blade and a battle ax made of serpentinite, a greenish metamorphic rock. The style of the stone ax suggests the burial was made around 2900 B.C., during the Middle Neolithic period (New Stone Age), according to the statement.

But a handful of teeth and bones that were also deposited in the grave as funeral offerings made the burial stand out as particularly unusual.

"The arrangement of the 42 teeth was precise," Dąbrowski said, "and upon further inspection, it turned out that all of them had holes drilled through their roots. They must have formed a kind of necklace."

The teeth that made up the necklace were incisors and canines that belonged to large mammals, such as wolves, deer, bears and potentially humans, Dąbrowski said in a Sept. 4 translated statement.

"It's possible we've discovered the grave of a warrior or hunter, but because of this necklace, we can assume it was someone important, for example, the leader of a family clan," Dąbrowski said.

The burial also contained the remains of two human skulls, which the archaeologists think may be from decapitated heads that were buried with the man as gifts or funeral offerings. However, further analysis of the skulls is needed to confirm or rule out decapitation, according to the first statement.

A similar elite person's burial filled with axes, flint tools and amber beads was previously discovered nearby, the researchers noted in the statements. In that case, the bones of a calf suggested that the animal had been sacrificed at the grave. But to date, these are the only two burials of their kind in the area. According to the statements, they might be from members of the Corded Ware culture, which likely spread Indo-European languages around Europe and Asia.

According to Dąbrowski, the next step is to analyze the remains from both Stone Age burials to figure out if the people were related and what their lives were like nearly 5,000 years ago. He expects the first results of the analyses to be available later this year.

What do you know about the Paleolithic, Mesolithic and Neolithic eras? Find out with our Stone Age quiz.

The Romans are well known for their aqueducts, which brought water to their cities and settlements.

These aqueducts sometimes ran for very long distances. For instance, the aqueduct of Valens, which brought water to the city of Constantinople (modern-day Istanbul), was 250 miles (400 kilometers) long, according to a statement from Johannes Gutenberg University Mainz.

The aqueducts also lasted a long time; their remains are some of the most prominent Roman architectural finds visible today. All of this demonstrates the Romans' engineering prowess. So how did the Romans build such large and long-lasting aqueducts?

Preparing the route

First, the Romans would select a source of water for the aqueduct, with springs being a popular choice. The aqueducts had to be designed so water would flow toward the city or settlement. The successful building of the aqueducts "was accomplished by an ever slight incline downwards from the spring to its end source," such as Rome, Ann Olga Koloski-Ostrow, a classics professor and chair emerita at Brandeis University in Massachusetts, told Live Science in an email.

Roman surveyors had to design a route carefully. "To choose a route with the necessary gradient, Roman surveyors would have either used the libra or the dioptra," Joseph Lewis, an archaeologist at the University of Cambridge, told Live Science in an email.

The dioptra was shaped like a disc with a sighting bar in the middle. It could be suspended from a stand, and the surveyor could look through the sighting bar at rods in the ground to help determine their elevations. "Surveyors would sight through the sighting bar toward surveying staves to measure differences to elevation," Lewis said.

The exact design of the libra is unclear, but we know that it had a plumb bob that was suspended in the air and the surveyor could compare it to rods in the ground to help determine differences in ground height. "Surveyors would set the libra up along proposed routes for the aqueduct and look forward and backward against calibrated staves," Lewis explained, noting that this allowed them to determine differences in ground height.

Building a long-lasting aqueduct

The Romans used a form of concrete that tended to last much longer than modern-day concrete. Roman concrete used pozzolan, an ashy substance, that was combined with lime and water to form a durable concrete that hardened when exposed to water.

"Roman concrete certainly played an important role, especially in bridges, arcades, and other structural elements," Giovanni De Feo, a professor of industrial engineering at the University of Salerno in Italy, said in an email.

But this wasn't the only factor that allowed Roman aqueducts to last such a long time.

"I believe their remarkable preservation results from a combination of factors," De Feo said. For example, the Romans were careful to select routes that followed stable geological formations.

Regular maintenance that, in many cases, continued into the Middle Ages also helped Roman aqueducts survive the test of time, De Feo noted. This means that they tried to avoid volcanoes and other landscapes that were unstable.

Aqueducts did not always run aboveground; sometimes, they had lengthy underground portions in areas where the landscapes made it difficult to place it aboveground. Some "aqueducts had hardly any stretches above ground outside the city, while others ran on arches for a considerable distance," Gerda de Kleijn, a researcher at Radboud University in the Netherlands, wrote in her book "The Water Supply of Ancient Rome" (J.C. Gieben, 2001).

As the water neared the city, it would sometimes go into pools that helped remove dirt and other visible pollutants. "Water would pool into the basin, sediment would sink to the bottom, then the water would continue from there on its course to the distribution tank," Harry Evans, a professor emeritus of classics at Fordham University, said in an email.

The number of workers required to build an aqueduct depended on its size and timeline for completion. The Hadrianic aqueduct at Athens, which runs for about 12.4 miles (20 km), could have been completed in 15 years by a team of around 500 workers, researchers estimated in a 2022 paper.

Maintaining the aqueduct

After an aqueduct was built, regular maintenance kept it in good shape. Cees Passchier, head of tectonophysics at Johannes Gutenberg University Mainz in Germany, has studied a Roman aqueduct at Divona in France. In a 2023 study, Passchier and colleagues found that carbonate would have built up on the aqueduct over time. Maintenance workers "partly scraped away" the carbonate before replastering the aqueduct, Passchier told Live Science in an email. At some other aqueducts, they wouldn't bother scraping but would "simply plaster over the carbonate without ever cleaning anything," he said.

A sizable number of workers would have been needed to keep aqueducts functional, but it varied based on the aqueduct's size. For "a small place like Divona, a workforce of a dozen people would probably have been enough," Passchier said. "We know that in Rome, there was a staff of a few hundred people to keep the aqueducts working."

Even after the Roman Empire collapsed, many of its aqueducts survived, as some were used and maintained into the Middle Ages and even into modern times. One of the aqueducts, the Aqua Virgo, built in 19 B.C., is still bringing water to Rome today.

From Augustus to Nero, see how much you know about ancient Rome's famous leaders with our Roman emperor quiz!

Over a century ago, German pathologist Georg Schmorl documented a strange phenomenon: cells from fetuses that had moved into the mother during pregnancy. He had discovered microchimerism — where the cells from one individual move into another and set up shop.

In the past few decades, scientists' understanding of microchimerism has grown, thanks to technological advances. And the implications are wild.

Cells transferred during pregnancy could mean you have cells from your grandmother living inside you. A twin can be "absorbed" within the womb, leaving a genetic trace of the lost sibling. And after a bone marrow transplant, a man ended up with the donor's DNA in his blood and semen. These are just a few examples of how microchimerism opens a new way to understand immunology, genetics and evolution.

In her book "Hidden Guests: Migrating Cells and How the New Science of Microchimerism Is Redefining Human Identity" (Greystone Books, 2025), author and journalist Lise Barnéoud explores how the field emerged and developed as scientists grappled with understanding what was going on, and why — as well as the far-reaching implications of these minuscule interlopers.

"Hidden Guests" has been short-listed for the 2026 Royal Society Trivedi Science Book Prize.

Excerpt from "Hidden Guests": 'It doesn't lie. So who are you?': What happens when DNA tests show a woman is not the mother of the child she gave birth to?

Live Science spoke with Barnéoud about the book, why the idea of microchimerism resonates so deeply, and where the field could be headed next. "Hidden Guests" has been short-listed for the 2026 Royal Society Trivedi Science Book Prize.

Hannah Osborne: What first got you interested in microchimerism? How did your personal understanding change over the course of writing "Hidden Guests"?

Lise Barnéoud: The first time I heard about it, I was writing my previous book on vaccinations, and I had a chapter on our immunity, how our immune system works. I wanted to explain what we got wrong about how our immunity works. We are still learning — [we used to have this idea] that our immune system is kind of an army patrolling in our body and expelling any foreign elements. That's the image we have of our immune system. I wanted to tell another story, which is more accurate because we know now that it's not working like that.

I was looking for counterexamples, and, of course, one very famous counterexample is pregnancy. We tolerate the fetus that is half different than us. Another well-known counterexample is microbiota. Inside our body, we carry microbial cells as well as human cells ‪—‬ so cells coming from bacteria, viruses, fungi. We don't expel them; we need them. The third example I found was microchimerism.

The more I read about it, the more I was interested in it. It was challenging so many things. I've learned that the placenta is not that watertight barrier that we often think of, that the immune system is not as intolerant as we often think, and we can inherit cells from our kids like an inverted inheritance. All those elements popped up within my first reading, and I thought, "OK, I really need to dig more."

For your second question, I think the biggest change is that I realized those cells are not only kind of inactive tourists, just homeless drifters passively traveling in our body. They are really active. They can multiply, they can produce protein, they communicate with other cells, and they really influence our physiology, for better or for worse.

HO: We see how microchimerism is a relatively new field of research that has had lots of stops and starts. What was the biggest hindrance to the development of the field, and what changed?

LB: Maybe before speaking about the hindrances, just saying that the first time we discovered cells from other individuals within individuals was a century ago. The first one was in 1893, and it was a German pathologist who discovered cells from fetal origin in lungs from women who had died during pregnancy. Then it took a century to understand that this phenomenon happened to everyone and that it is of importance.

I think there are several hindrances. There's never one big one. The first one we can think of is the technology, because you need to study these microchimeric cells; you need tools that are able to study a tissue at the cellular level. This is quite new, so now we have these tools and we can make some progress. The second big hindrance is that this research field calls into question the traditional view of the immune system. If you see the immune system as a purely defensive and intolerant army, then you can't think of these foreign cells staying forever in your body, and that was a big hindrance, I think.

Maybe a third hindrance is that at the beginning of this field — I mean the new beginning in the '90s — they were mostly women working in this field. They told me that male colleagues often said, "Well, that's woman's stuff, you know; you're looking for some connection with your babies, but it's not really relevant," which is wrong, of course, because even men are affected by this phenomenon. They stayed nine months in the womb like us.

That might have, at least, challenged some of the first pioneers of the field. Now there are more and more men working in the field. In April, there was an international conference on microchimerism, and I think it was half women.

HO: The book includes many anecdotes about people directly affected by microchimerism. Which story were you most affected by, and why?

LB: I guess it'd be the story of Lydia Fairchild because she nearly lost custody of her children because of microchimerism. She was 26 and living in the U.S., and she applied for a welfare benefit to help her raise her kids. In the U.S., you need to undergo a maternity test for that, and her DNA test ends up showing that she could not be the mother of her kids. Of course she tried to argue; she had photos; she had testimonies. But she was always told, "DNA is 100% foolproof; DNA doesn't lie," which implied that she was lying. But she was not, so she called several lawyers. But at the beginning, they were all saying, "No, DNA doesn't lie."

At that time, she was pregnant with her third child, and they decided to do a test immediately after birth. Again, the impossible happened. This third child that just emerged from her womb was not her son — genetically speaking, at least.

In fact, she was harboring cells from her vanished sister inside her. Most of her eggs carried her sister's genetic signature, which means that the mother of her kids never lived. Isn't it amazing? That's maybe one of the stories that blew my mind.

HO: The section on DNA and how microchimerism complicates things is fascinating. How much of an impact do you think hidden cells have on the reliability of DNA evidence?

LB: The truth is that I think we don't really know. If you have only some microchimeric cells, among thousands of your own cells, then it won't change the reliability of the DNA test. But in some cases, these microchimeric cells can make up a significant part of an organ and sometimes even an entire organ. This proportion might depend on when you received those microchimeric cells. For instance, if you received those cells like Lydia Fairchild at the very, very beginning of your development, they might end up making up the entire organ where they landed first. But probably, we don't know which percentage of us start our in utero life with an evanescent embryo.

I looked for this number because I didn't really know about evanescent twins, so I wanted to know how many pregnancies started with several embryos and suddenly one disappeared. And I couldn't find any good number because, of course, it's quite difficult to put any imaging there at the beginning of the condition. Some articles say that up to 30% of pregnancies will start with several embryos, which means a lot of us are affected by evanescent twins. But let's say it might be rare that we have so many microchimeric cells in one organ that it completely changed a DNA test.

But there's another example in my book that took place in Alaska in 2004. After a rape, the forensic investigators collected the semen from the scene, and they discovered that the DNA in this semen matched with a man who was already in the database. But this guy was behind bars. He was in jail, the day of the rape, so he couldn't be the rapist.

Finally, investigators discovered that this guy, the prisoner, received a bone marrow transplant a few years ago from his brother, and the cells from the bone marrow of his brother didn't stay quietly in the bone marrow and blood. They go outside the marrow, and some end up in the semen. And the true rapist was the brother, the one who donated the bone marrow, and not the receiver. Without the alibi of the prison, the brother who received the transplant would have been charged, and the true rapist would have been left free.

I guess there are some cases where microchimeric cells can really change the result of a DNA test. But for now, it's not really studied. I've been contacted by some forensic investigators to learn more about microchimerism, so maybe things will change.

HO: You point out that microchimerism is used for both pro- and anti-abortion arguments, and it's used by "manosphere" influencers to promote ideologies. Why do you think microchimerism research is so open to interpretation and used in this way?

LB: Next time you're at a dinner, just try to explain microchimerism. You're a science journalist, right? Well, usually when you tell the story you're working on, people are saying, "Oh, yeah, OK." And they just turn to another conversation. If you try mentioning microchimerism in your next dinner, then you'll see. Everyone will try to make some hypothesis, some connection; some will be moved that it's possible to keep some cells from an unborn child or a lost child. Some will be disgusted by the idea that they keep cells from their mother, like having their mother on their shoulder all the time. It's really the first time as a science journalist I experienced such resonance with a story I was working on among people around me, people who are really not into science.

As soon as the door opened, it revealed the fears and the desires of people. So yes, some conservatives use microchimerism to fight against abortion because they say the cells from those aborted will haunt the women for the rest of their life. [But] I've met scientists explaining that if you receive a shot of cells of fetal origin, it can also help you to regenerate your organs. It can be used also by some other people to rejuvenate, to try to stay young.

It's because it's such a new field and you have such open questions, there's room for many interpretations, many hypotheses. I mean, that's fine; that's how science works. You should always have hypotheses and try to answer your hypothesis with new experiments. But it's true that sometimes I didn't know how to handle all those ideas at the beginning. Then I realized it was like a window open on the intimate — their fears and their desires — and it reveals what they really think about their connection to the world they are in. From a sociological point of view, it would be really interesting to study that.

HO: In the book, biologist and evolutionary theorist Amy Boddy warns that microchimerism researchers love to hypothesize. When the implications of the field are so far-reaching, how do we get past this? Which hypothesis do you find most intriguing?

LB: Many scientists told me that until 2021 or something like that, there was this hypothesis that those cells could come from another generation than the mother. We knew that the mother would give cells to the fetus and the fetus could give cells to the mother, but then people ask, because the mother can still carry cells from her mother, maybe she could pass those cells to the fetus. Until the 2020s, scientists were thinking, "Well that's a crazy hypothesis; that can't happen." There could be only a few cells that won't go through the placenta and integrate with the new fetus — until one scientist proved that a newborn can carry cells from the grandma.

In this field, you always have crazy hypotheses, and I guess until we haven't proved that this hypothesis is wrong, you can still leave the hypothesis on the table. One of the craziest hypotheses, the first time I encountered it, I thought, "OK, they've gone really too far."

This hypothesis is that we could inherit cells from our sexual partner. I thought it was not possible because I thought the semen was full of spermatozoa, that they are only like half cells having only half chromosomes, so they cannot survive. But actually in semen, you have a lot more cells than spermatozoids — you have immune cells, for example.

There are many cells in the semen, and we can think that if you have some, there could be some path for those cells to escape and go into your blood. It's not completely crazy. For now, there's no formal proof of this new source of microchimerism, but I recently heard that some scientists are working on the topic on mice.

We should be careful about those interpretations. But I think scientists are not the ones who should care about this interpretation; otherwise, they would prevent themselves from doing their research. They should open all the doors with all kinds of hypotheses. If we do it in a scientific way, meaning if we try to answer a hypothesis with good experiments, then I think everything is fine. You will never prevent people around you from using this information to distort the facts and tell another story. That's how life goes.

HO: What do you think the most promising use for microchimerism research will be over the next 10 to 20 years? How do you see it unfolding?

LB: I guess it will be in the regeneration field. We have discovered that those cells can participate to regenerate tissue. Some scientists around the world are doing clinical studies to see whether we could use these cells as a therapy either after an infarctus [heart attack], but also a vascular accident [stroke] or when you have a wound on your skin. The hope is that by either attracting microchimeric cells that are within our bodies, or injected, these microchimeric cells maybe can help this kind of tissue to repair. I think that might be one of the promising uses of these cells in the future.

Maybe also in the transplantation field; maybe we can think about using the knowledge of how microchimeric cells can induce tolerance to avoid [immunosuppressive] drugs. When you receive the transplant, you need to take drugs [that suppress the immune system] for the rest of your life, and those drugs are like really strong drugs. If we can use microchimeric cells before the transplant to allow better tolerance, then we could either not use any drugs or maybe use less drugs. That would be really interesting, too.

This interview has been condensed and edited lightly for clarity.

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