The written word is one of humanity's most important information technologies. Without it, mathematical and scientific discoveries would be lost to history. But it can also lock ideas in place long after they've stopped making sense.

So does writing speed up cultural change or slow it down?

Russell Gray, a professor in the Department of Linguistic and Cultural Evolution at the Max Planck Institute for Evolutionary Anthropology in Germany, heads a research project investigating how writing affects the way languages change. His team uses methods borrowed from evolutionary biology to trace languages through family trees — similar to the way biologists trace species.

Language is one element of culture that researchers can measure to determine whether writing speeds up or slows down cultural change.

"The obvious answer," Gray said, is that writing slows culture down because writing "is all codified and specified and people get trained in it." Gray doesn’t think the obvious answer is necessarily the right one. But other researchers agree that writing can lock in ways of thinking.

"Writing can lead to what learning psychologists sometimes call 'canalization,'" Charles Perreault, an associate professor in the School of Human Evolution and Social Change at Arizona State University, told Live Science in an email. "It can narrow the range of ways people think about a problem. When a rule, method, or story is written down, people may come to see it as the correct version … and may not even consider that a better or different way could exist."

Religious texts and legal codes are good examples. In both cases, the interpretation of rules written hundreds ‪—‬ or even thousands ‪—‬ of years ago shapes the way things are done, long after the circumstances that produced them have changed.

This idea shows up in artistic expression, too: A 2017 analysis by ethnomusicologist Patrick Savage looked at more than 4,000 British-American ballads from the 16th through 20th centuries and found that written melodies changed less than those shared through oral tradition.

But there are also ways that writing may speed up cultural change.

"Before writing, much cultural knowledge had to be stored in people's brains," Perreault said. "That has obvious limits."

People forget things they don't study routinely, and when people die, their knowledge often dies with them. Because writing moves information storage beyond the human brain, it can reduce those losses, Perreault said.

"If writing prevents knowledge from being lost, and if it also helps information spread through a society, as with the printing press, then it could accelerate the ratchet effect of cumulative cultural evolution," Perreault said. "But this remains, to some extent, a hypothesis."

By the book

One reason the question of whether written language speeds or slows cultural evolution is that writing is hard to separate from everything that comes with it.

Writing has been separately invented only around four times in human history — although "some people argue there's a fifth in India," Gray said — which means nearly every writing system on Earth descends from that handful. Those systems spread through contact; trade, war, religion and the other ways humans intermingle had their own effects on cultural change that are hard to untangle from the effects of writing.

Also, "mass literacy is quite recent," Gray said. "If you've got these written varieties that are just used by, often, religious elites, that's potentially going to have much less impact."

So which force wins? Both experts think writing speeds up cultural change, though neither can prove it yet.

"I would say that writing probably speeds up cultural change overall," Perreault said. Gray agreed, though he acknowledged that most people would guess the opposite.

Still, Perreault cautioned, "these are empirical questions that have yet to be answered empirically."

Flu season is off to an early start in some parts of the U.S., data shows.

In a typical year, U.S. flu activity starts building in late fall — typically in October or November — and peaks between December and February. This year, flu activity is currently low but rising nationwide: During the week ending Sept. 26, 3.4% of respiratory samples tested by clinical labs were positive for flu, according to Centers for Disease Control and Prevention (CDC) data.

That's about seven times the rate that was seen at the same point last year. About 0.5% of samples tested positive during the week ending Sept. 27, 2025.

"This particular year, it appears to be starting early — like right now," Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt Health in Tennessee, told Live Science. Patients at clinics in his area are already testing positive for flu, he said.

The early uptick in flu is mostly unfolding in Western states, including Washington, California and Arizona. In Washington, for example, the share of emergency department visits diagnosed as flu climbed from 0.25% in the week ending Aug. 29 to 1.34% in the week ending Oct. 3, according to CDC emergency department data. That's a more than fivefold increase over six weeks.

Where the flu took off first isn't a warning sign in itself, Schaffner noted.

"There's nothing unusual about flu starting in the West Coast and moving east," he said. Recent seasons have more often begun in the Southeast or Midwest, he noted, but "it can start almost anywhere."

Leading with H1N1

Nowadays, seasonal flu is caused by three subtypes of flu viruses: two subtypes of influenza A, called H1N1 and H3N2, and the Victoria lineage of influenza B. (A second subtype of influenza B used to circulate but is now thought to be extinct.)

Last season, a fast-spreading version of H3N2 known as subclade K dominated. The CDC classified the 2025-2026 season as highly severe for children, as at least 195 children died of flu-related causes.

Schaffner likens influenza A and B to siblings. "They're very related, but they each have their own individual characteristics," he said. Influenza A strains usually cause the biggest outbreaks early in the season, while influenza B strains "kind of smolder along" and account for most cases toward the end, he noted.

This year, H1N1 has taken the initial lead. Of the influenza A samples that public health labs subtyped during the week ending Sept. 26, 96% were identified as H1N1, according to CDC data. That doesn't mean H1N1 will continue to dominate throughout the season; it just gives a snapshot of what's happening now.

The dominant strain matters because flu is "a moving target," said Dr. Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia. The virus constantly mutates — especially hemagglutinin, the protein on the virus's surface that it uses to latch onto human cells. Hemagglutinin is the main target of flu vaccines.

An early start to the season doesn't guarantee it'll be a severe one, either. In its 2026-2027 season outlook, the CDC projected that this season will likely be moderate, although it has only low-to-moderate confidence in that forecast.

When to get vaccinated

Everyone 6 months and older is recommended to get an annual flu vaccine.

Influenza is especially dangerous for children under 5, adults 65 and older, people with chronic health conditions and pregnant people, as these groups are more prone to severe infections. Serious cases of flu can lead to complications such as pneumonia, sepsis, and brain or heart inflammation, and in some cases, they can be deadly. Tens of thousands of people die of flu each season in the U.S.

For flu vaccination, timing matters. The CDC generally doesn't recommend vaccination in July or August for most adults, because the shot's protection can wane over the course of a season. But with flu arriving early, "October is the ideal time to get vaccinated, and even more so right now," Schaffner said.

When circulating strains' features differ from those captured in the vaccine, "that usually predicts a more difficult season," Offit said. That said, it's too early to know if this year's flu shots are a good match for the circulating flu viruses.

Protection begins building right after you get the shot, but it takes up to about two weeks to reach full strength.

How much protection a flu vaccine offers varies by season, depending partly on how well its formulation matches the strains that circulate. Offit said that protection against symptomatic illness varies by age group and that the vaccines are "a little more effective" at preventing more severe illness. In terms of flu cases that prompt people to seek medical care, the shot has been 29% to 56% effective over the past decade, the CDC estimates.

While the vaccines are less reliable at preventing mild cases of flu, Schaffner said, they work best at "keeping you out of the hospital, keeping you out of the intensive care unit, and keeping you out of the cemetery."

The CDC's 2026-2027 guidance keeps its recommendation of an annual flu vaccine for everyone 6 months and older, with high-dose and adjuvanted shots preferred for adults 65 and older. (Adjuvanted shots contain an extra ingredient to help rev up the immune system.)

There's also a new option: In August, the Food and Drug Administration approved mFlusiva, the first mRNA flu vaccine, for adults 50 and older. (You can find out where mFlusiva shots are available near you using Moderna's vaccine finder.) With the mRNA shot, "you're less likely to get symptomatic disease," Offit told Live Science.

Traditional flu shots contain purified pieces of the virus itself, Schaffner explained. With mRNA, the vaccine contains a "blueprint" of those proteins — essentially a set of genetic instructions that the body's cells then use. In mFlusiva's case, those instructions code for hemagglutinin (the protein on the virus's surface that it uses to latch onto human cells) from each of three flu subtypes, Offit said. The mRNA then breaks down in the body, Offit noted. It "cannot influence human genetic material," Schaffner emphasized.

Whether this early start gives way to a heavy flu season should become clearer in the coming weeks, as the CDC's weekly surveillance reports will show whether cases keep climbing beyond the West.

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

Imagine you're road-tripping across the country 10 years from now. You spend a few minutes charging your electric vehicle and then set off — and your car's solar paint keeps it charged as you drive.

Your eyes are on the stunning scenery, taking in the vistas along Route 66 or the grandeur of the Rocky Mountains, or you're catching up on messages. Your hands barely touch the wheel, and your foot doesn't push a pedal. Your car communicates with others on the road, so there's no need to brake suddenly or swerve. That's because it knows a vehicle five cars up from you has done so, and all those in between are slowing at exactly the right pace to avoid dramatic changes in trajectory.

And when you park for the night, your car makes you money, selling the excess energy it's harvested from its paint back to the grid. Or maybe you don't feel like being in the driver's seat at all, so you hail a self-driving car and take a nap in the back seat in between adventures.

Some of that scenario may become a reality in the next 10 years, at least for those who are using the most cutting-edge cars on the market. Although there's some heavy speculation involved in that futuristic vision, vehicle manufacturers are already incorporating increasingly sophisticated automated driving technology into high-end personal vehicles, and self-driving taxis are coming to dozens of U.S. cities.

What's more, dramatic changes in range, cost and charging speed for electric vehicles (EVs) are arriving at a rapid pace. While some of these technologies may not wind up in personal cars, others are already taking to the roads.

An ecosystem of connected vehicles

Some car models within the next decade may interact with their surroundings in new ways, including by communicating with other cars to avoid collisions, drawing energy from natural sources, or letting drivers get paid for sending their cars' unused energy back to the grid.

If you're driving an EV, you might avoid the hassle of finding a charger when you're at work or running errands. In 2024, EV company Aptera unveiled a prototype car equipped with solar panels. Those panels — on the car's hood, roof, dashboard and hatch — allow the vehicle to travel about 40 miles (64 kilometers) per day on solar power. That's more than the average American drives per day. Aptera's vehicle can also travel up to 400 miles (640 km) on a standard electrical charge.

Some sunlight-powered cars might ditch the solar panels altogether in favor of a more integrated design. In 2024, Mercedes-Benz revealed it was researching a photovoltaic paint that could convert sunlight into energy for electric cars. In sunny cities such as Los Angeles, the company calculated, the paint could draw in enough energy to power the car for nearly 7,500 miles (12,000 km) per year. The tiny particles in the paint convert about 20% of the energy from sunlight into electricity, which is comparable to the efficiency of existing solar panels.

You might even be able to sell some of the energy stored in your car's battery back to the grid. EV owners could charge during the day or late at night, when the demand for electricity is lower and pay lower rates for electricity. Then, in the evenings when the electrical grid is under more strain and the price of electricity is higher, they could sell that stored energy back at a profit.

Standardized software programs that throttle EV charging speeds during peak hours already exist. Drivers can use them if, for example, they want to keep charging costs down by primarily charging their cars during off-peak hours when electricity costs are lower, or if they want to use electricity only from solar power to charge, said Rajit Gadh, a researcher who studies EV charging and scalability at UCLA. But the process for sending energy back to the grid is a different story. Individual manufacturers haven't yet landed on a standard way to tell cars when and how much energy to discharge, Gadh said.

"What is needed is really [for] every EV charging vendor ‪—‬ and every EV manufacturer, actually ‪—‬ to have this protocol built in, adhere to it in its full specification, and make it available," Gadh told Live Science.

With the right protocols, though, cars of the future will be able to do more than interface with the electrical grid. "Vehicle-to-everything" technologies could enable cars to communicate with infrastructure and other vehicles to avoid traffic and collisions.

Some cars today are already equipped with vehicle-to-vehicle (V2V) communications. These systems use short-range radio signals to alert other V2V-equipped vehicles of the car's speed, direction of travel and braking patterns. The radio signals can travel about 1,000 feet (300 meters), allowing the vehicle to receive data from cars that are not in the driver's line of sight.

V2V systems could help reduce traffic collisions by warning drivers about oncoming cars they can't see yet — for example, by alerting a driver to another car speeding toward an intersection or coming around a bend as the driver is passing another vehicle on a twisty, two-lane highway. Not all cars have the technology, though, so its practical utility is limited for now.

Hands off the wheel; eyes off the road

Some driver assistance technologies, such as lane departure warnings and cruise control, have been on the market in personal cars for decades. These technologies and more recent assistive features require the driver to be in control of the vehicle, but theoretically, they make driving easier. For example, Tesla's Full Self-Driving (Supervised) mode handles most steering and braking tasks, but safe operation requires the driver to keep their eyes on the road and be ready to take over at a moment’s notice. In the next several years, drivers will likely see new features that automate driving in more contexts.

Some of these features will allow drivers to take their attention off the road entirely and enjoy some in-car entertainment, as long as they're alert and able to retake control of the vehicle within a few seconds if conditions change. Technologies that fully automate driving in many circumstances within certain service areas will likely be in about 4% of cars on the market by 2035, according to a white paper from the World Economic Forum.

In cars equipped with these features, "you're still going to have driver controls, but under certain circumstances, it will be effectively an automated vehicle," Luke Neurauter, who leads the Division of Vehicle, Driver and System Safety at the Virginia Tech Transportation Institute, told Live Science.

Mercedes-Benz introduced its Drive Pilot system for two consumer car lines in 2022. On the entire German Autobahn network and on certain freeways between and around Los Angeles, San Francisco and Las Vegas, during heavy traffic, the system lets the driver turn their attention toward other activities, such as reading a book or eating lunch, while the car handles steering and keeping pace with other nearby vehicles.

But as the artificial intelligence (AI) models that control autonomous driving improve and become better able to handle unusual scenarios — often called "edge" or "corner" cases — on the road, drivers will be able to hand over control to their cars in more situations, said Rahul Jain, an electrical and computer engineer at the University of Southern California.

Future AI systems might "have some reasoning ability, and then because of that, it can handle these corner cases much better than current systems are able to do," Jain told Live Science. For example, a car might be able to better respond to an indecisive pedestrian who suddenly enters a crossing, assess whether to enter potentially hazardous conditions such as flooded roads, or safely navigate around unusual circumstances, such as construction work, on a highway.

While some systems will enable drivers to make fewer decisions, others that may roll out in the next several years will track a driver's attention and alert them with sounds, an indicator light or haptic feedback when their focus falters. These systems use cameras and software to track head position, eye movement and steering-wheel input to ensure drivers are focused on the road even when they're using assistive features such as lane centering, Neurauter said.

In addition to looking for distracted driving, the technology might expand to monitor drivers for fatigue and alcohol impairment, he added. That information could then affect "whether or not other features become active, or change how they act, based on the driver state at that moment in time," Neurauter said. Proposed legislation could make this technology a requirement in new vehicles as early as 2027, but technological hurdles and concerns over privacy and false positives could stall its implementation.

The technology could also assist drivers who become unable to safely operate the vehicle — for example, if the driver falls asleep or experiences a medical emergency. If a car detects that the driver is not holding the steering wheel or actively controlling the vehicle, it could send a series of visible, audible, or tactile alerts. If the driver doesn’t respond to those cues, a car might turn on its hazard lights and come to a stop. Some vehicle manufacturers are already rolling out such technology; for example, Volkswagen has made it available in all new vehicles from model year 2025.

Fully autonomous vehicles

While personal cars may not offer full automation, highly automated car services will become much more common as rideshare vehicles in major metro areas. In some cities, like San Francisco, commuters already rely heavily on autonomous vehicles from Waymo. The company has rolled out its cars in nearly a dozen cities —‬ including Dallas, Houston, Atlanta and Los Angeles —‬ and has announced plans to expand service to more than 20 additional locales. Other companies ‪—‬ such as Nuro and Volkswagen’s MOIA ‪—‬ are testing their vehicles with human drivers on board before rolling out full public service.

Currently, autonomous vehicles navigate by combining information from preloaded, high-resolution maps and real-time radar, lidar and visual data collected by cameras and sensors attached to the car. An onboard computer uses that information to build a 3D map of its surroundings. Right now, the cost of these sensors makes them impractical for consumer vehicles, Jain said, but they’re becoming cheaper as manufacturers scale up production. The cars also use an AI model trained on both common and unusual driving situations to anticipate how other vehicles and pedestrians will behave and plot a safe path forward, Jain added.

Developing those high-resolution maps takes time, which is one of the main reasons autonomous rideshares aren’t available everywhere yet. Mapping usually involves decking out a car with high-end visual sensors and lasers and driving it throughout the region. Although cities like San Francisco have been mapped with this level of precision, much of the U.S. has not.

"It's very difficult to do overnight," said John Dolan, an autonomous-driving researcher at the Carnegie Mellon University Robotics Institute.

Complexities also tend to arise in city environments, where unexpected stops are more common and there are many pedestrians who behave unpredictably or jaywalk. But interstate highway driving doesn't face as many of those obstacles, and that could enable autonomous long-haul drives.

"[Autonomous] trucking, I would expect, would be the first thing that's going to happen" in terms of autonomous travel outside of major cities, Jain said. A few driverless trucks are already on the road: Pittsburgh-based company Aurora deployed the technology on I-45 in Texas, between Dallas and Houston, in 2025, with plans to expand across the southern U.S.

Longer range and faster charging

While there's speculation involved in predicting the range of self-driving capabilities available in a decade, the picture for EVs is a little clearer.

Right now, lithium-ion batteries dominate the EV market. Each cell in a lithium-ion battery has two electrodes, commonly a layered graphite electrode and a metal oxide or phosphate electrode, separated by a liquid electrolyte solution. Lithium ions migrate back and forth between these two electrodes when a person charges and discharges the battery.

Many electric cars with lithium-ion batteries can already travel more than 300 miles (480 km) on a charge. But that's not ideal for a long-range car trip, because charging stations are few and far between in the country's vast interior and charging takes longer than filling up a gas tank.

Solid-state batteries, which replace the liquid electrolyte with a solid electrolyte made of ceramic, polymer or sulfide materials, could make that cross-country trip in an EV a practical option, allowing an electric car to travel more than 750 miles (1,200 km) on a single charge. Some prototype battery packs can already achieve this range under controlled conditions. If a solid electrolyte were paired with an anode made of pure lithium, rather than graphite or hard carbon, it would allow the battery to store more energy than a lithium-ion cell of similar mass can.

Solid-state batteries may also enable faster charging. In current batteries that use liquid electrolytes, charging and discharging the battery too quickly can cause dendrites, thin branches of lithium that stretch across the cell and short-circuit the battery. A solid electrolyte could, in theory, block those dendrites, which would enable cars to charge fully in just 10 to 15 minutes. The higher energy density from a lithium metal anode also translates to a greater range than that from a similarly sized lithium-ion battery, Eric Wachsman, director of the Maryland Energy Innovation Institute at the University of Maryland, told Live Science.

Cheap EVs

Many of the raw materials that go into existing lithium-ion batteries are concentrated in a handful of geographic areas. In 2023, Australia, China and Chile mined about 85% of that year's lithium supply; China mined the majority of graphite used that year as well. And battery materials still make up a significant portion of an electric vehicle's cost.

Sodium-ion batteries could be cheaper and easier to source. Sodium is plentiful in Earth's crust, which means mining could be done throughout the U.S., potentially with a comparatively low environmental impact.

Such batteries also rely on a more widely available electrode material. Sodium ions are larger than lithium ions, so they don't fit in between layers of graphite like lithium ions do. Instead, sodium-ion batteries use hard carbon electrodes.

"When you cook at home and your soup boils over and you get this black ring around your pot, this is hard carbon," Maximilian Fichtner, a solid-state chemist at the Helmholtz Institute Ulm for Electrochemical Energy Storage in Germany, told Live Science. "You can produce this from sucrose or from biomass, from whatever. You can do that everywhere."

The downside is that hard carbon holds less sodium than graphite holds lithium, said Eric McCalla, a battery materials chemist at McGill University in Canada. That means sodium-ion batteries can't store as much energy relative to their mass, and they don't last quite as long as their lithium counterparts.

"The range won't be as large," McCalla told Live Science. "It'll be a fantastic commuter car, but you're not going to go on a family trip from Montreal to California so easily."

Manufacturers are already bringing sodium-ion technology to market. For instance, the Chinese company CATL began mass-producing the batteries in February and claims that their battery packs enable EV ranges over 250 miles (400 km).

But new technologies are being developed rapidly. For example, some scientists are making sodium-ion batteries that use solid electrolytes, combining the higher energy density of solid-state lithium batteries with the cost savings of sodium batteries.

This hybrid battery chemistry is still in the early stages of development, experts told Live Science. "I would be surprised to see them in cars in the next decade," McCalla told Live Science in an email. "I've been surprised before, though."

Bumps in the road

The future we're describing is the utopian scenario. But the biggest obstacles are likely not technological but rather regulatory, economic, political or cultural, experts said.

"We're going to try to guess at a timeline of when some of these things are going to come in, and odds are, we're going to be wrong," McCalla told Live Science. "Odds are, we're going to be slower than we think."

Solar panels may not wind up being the most economic or practical way to increase EVs' range, while scaling up manufacturing capacity for next-generation batteries is expensive and could slow EV adoption in the U.S. The utility of vehicle-to-vehicle communications, meanwhile, could be limited by a slow rollout and adoption of V2V-equipped cars among drivers.

Whether EVs will be ubiquitous will likely come down to their affordability relative to gas-powered vehicles, which is affected not just by manufacturing and technological advances but also domestic policy choices, such as whether to subsidize EVs or their charging networks.

One challenge for manufacturers is that the automated features drivers prefer may not always be safer. A recent review of automated systems found that those focused on driver safety, such as automatic safety or lane centering, tend to reduce crashes, while those focused on comfort, such as adaptive cruise control, can increase accidents. The authors proposed that such systems make it easier for people to disengage or become distracted while driving and possibly overestimate the capabilities of the system.

And there are other kinks to work out for autonomous rideshare vehicles. In December 2025, a horde of Waymos stalled during a power outage, clogging San Francisco intersections. The cars are programmed to treat dark traffic signals as four-way stops, according to a statement from Waymo, but they occasionally ping human operators for confirmation. During the outage, the number of confirmation requests spiked, leading to delayed responses — and lengthy traffic jams. The company says it has since released software updates that allow its vehicles to act more decisively at dark signals. But questions remain about how the fleet will respond in natural disasters, and some have expressed frustration that autonomous rideshare vehicles already slow down ambulances, fire trucks and police cars responding to emergencies.

One of the biggest roadblocks to automated driving is the regulatory environment, Neurauter said. Regulations on self-driving vehicles vary by state, and some, such as New York, effectively prohibit driverless vehicles entirely. Where they are legal, they often must carry higher insurance and pass testing, which could limit their rollout.

"When we get into automated driving, the driving behavior is being governed by software that's installed on a computer that's in the vehicle," Steven Shladover, a research engineer at the University of California, Berkeley, told Live Science. "That gets us into a messy gray area where both the federal and the state roles kind of overlap, and that's politically very complicated." For example, different states could end up with different rules for establishing who's legally responsible for an accident involving automated driving.

In 10 years, you'll almost certainly be able to drive from Los Angeles to Las Vegas in an autonomous vehicle. But if you want to drive to New York City, you might have to stop in New Jersey — and take a train into the city.

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Researchers have developed a new type of tattoo ink that can be switched on and off with light, allowing colors and images embedded in the skin to be changed and even "erased" without having to go through the painful tattoo-removal process.

The system, which is being commercialized under the name PhotoTat, could eventually give people a way to conceal or change permanent body art. It could also have more practical applications, including medical tattoos that are visible only when a doctor needs to see them, researchers reported in a study published Friday (Oct. 9) in the journal Matter & Light.

"This is a tattoo that you can have, and whenever you decide you don't want it to be showing anymore, or you just don't want it there, you just turn it off," said study co-author Carson Bruns, an associate professor of biomedical engineering at the University of Colorado at Boulder. "And that's it. You don't have to turn it on again."

Working like a light switch

PhotoTat contains three primary color inks — blue, magenta and yellow — made with photochromic dyes, which are light-sensitive compounds that can change color with different wavelengths of light. These dyes are encapsulated in nanoparticles of polymethyl methacrylate (PMMA) — a medical-grade, glass-like plastic that is already used in medical implants and dermal fillers.

The dyes change their molecular structure when exposed to specific wavelengths of light. A 365-nanometer ultraviolet (UV) LED can activate pigments in around two to three seconds, Bruns said. Once activated, the colors can persist for hours to days under typical indoor lighting. But once the wearer exposes their skin to the bright outdoor sun, the colors disappear in seconds, erased by the intense light.

That makes the tattoo unique, as the pigment itself remains in the skin but the tattoo's appearance changes. Bruns and his team found that all three PhotoTat channels remained switchable in the skin for between 1.4 and 2.2 years.

Tattooing yourself for science

The three colors enable someone to activate different portions of a tattoo using different wavelengths of light. That means the magenta part of the tattoo might be turned on with green light, while the yellow pigment would be activated by blue light. This allows the wearer to customize their design and coloration to whatever they want at the moment — from a purple cherry to a yellow group of hearts.

That feature makes PhotoTat appealing for "people who love tattoos and have lots of tattoos, but just want something kind of fun and playful to add," Bruns told Live Science.

Bruns has tested each iteration of PhotoTat's inks on his own skin. His art is arranged in a series of tattooed scales, with different ink formations in individual scales.

"I gave myself these scales on purpose because they're each sort of a container for an experiment," Bruns said. The result, he joked, resembles a "magical mermaid trick," with some scales appearing out of nowhere and others changing color when activated.

The technology can also be combined with conventional tattoo ink. A permanent black ink design, for example, could contain hidden PhotoTat elements that appear only when activated.

The new tattoos could be appealing to people who want tattoos but are hesitant about their permanence, as well as to people who love their tattoos but occasionally need to conceal them because of work, social expectations or family, Bruns said.

"It's going to be on for most of the time, but just for this one moment, I'm going to turn it off for you grandma, for example," Bruns said.

Medical tattoos

Bruns thinks the tattoos could be helpful in a medical setting, too. Patients undergoing radiation therapy, for example, sometimes receive permanent tattoos that help doctors precisely align radiation beams. While useful, those marks remain after the treatment, reminding the patient of their experience. These would make such markings invisible if a patient wants them to be.

PhotoTat could potentially allow similar markings to be switched on during surgery and hidden afterward.

Bruns has spent several years developing other smart tattoos for medical applications, including a dosimeter-type tattoo that measures the amount of UV radiation a wearer experiences, along with a tattoo that changes color when the wearer is exposed to dangerous gamma radiation.

"It's not for you and me, but if you're like an astronaut or a nuclear engineer, they have to wear these dosimeters," Bruns said. "So, we have like a dosimeter tattoo that sort of puts that in your skin."

So far, Bruns and a fellow tattoo artist, have only commercialized the purple PhotoTat ink, after running the ink through a series of third-party medical tests.

The tests showed the purple is safe for use, and available to order, but it isn't cheap at $100 for a small bottle. Bruns hopes as more research is done, he can bring the other colors to market and lower the production cost, so the technology is more accessible.

Two people born on the exact same day can age in totally different ways ‪—‬ one in relative health and the other with chronic disease. Now, scientists have found a key difference in the immune systems of people who are more prone to age-related conditions, and it could help explain why some people remain healthier longer.

In young people, the immune system contains many naive T cells, a type of white blood cell. Over time, exposure to pathogens and vaccinations transforms some of these T cells into memory cells, which can respond quickly to defend the body against germs.

These memory cells make different types of characteristic proteins, called granzymes, which kill infected cells. They come in different "flavors," including granzyme K and granzyme B.

In a new study, published Friday (Oct. 9) in the journal Immunity, scientists found that individuals with more memory cells that make granzyme K than cells that make granzyme B tend to have healthier aging.

In the future, the balance of cells making granzyme K and granzyme B in a person's blood could be used as a test to determine "whether you're on the right trajectory of aging or not," study co-author Maxim Artyomov, an immunologist at Washington University in St. Louis, told Live Science.

Hunting for a signature of healthy aging

In earlier research, the same team found that, in old lab mice, granzyme K-making cells accumulated in several tissues and were linked to inflammation. They also observed the same increase in granzyme K cells in blood samples from older adults.

In the new study, they uncovered another piece of the puzzle: a dynamic with granzyme B-producing cells.

They began by analyzing immune cells sampled from over 2,600 people ages 18 to 97, looking at the balance of granzyme K- and granzyme B-making cells. They found that people with a lower ratio of granzyme K to granzyme B cell populations were more likely to have autoimmune diseases or other chronic immune conditions.

In a second analysis, they looked at both immune cells and blood-borne proteins sampled from 329 people, using the data to pinpoint a "protein signature" linked to an abundance of granzyme B-making cells.

They went on to hunt for this protein signature in around 48,000 participants who'd provided data to the UK Biobank, a large database of health data from U.K.-based adults. People who were predicted to have higher levels of granzyme B-making cells based on their blood proteins had worse health outcomes in the following 17 years, with a higher risk of death and of conditions like diabetes, high blood pressure, and liver and kidney disease.

The findings might point to an aspect of immune aging that wasn't previously understood.

"I think that's really exciting," Claire Gustafson, an immunologist at the Allen Institute, said of the results. "It highlights there's potentially some novel biology that we haven't really observed before," Gustafson, who was not involved in the research, told Live Science.

However, while there's a strong association between the balance of these cell populations and disease risks, Artyomov emphasized that the study does not prove that this ratio directly causes the poor health outcomes. Further studies would be needed to understand why having more granzyme B cells is linked with poorer health.

"This observation might be just a consequence, not a cause of the disease," Artyomov noted.

It's also important to note that granzyme K-making cells in mice are not the same as granzyme K-making cells in humans. In mice, they represent a more mature, specialized stage of immune cell development, whereas in humans, granzyme B cells better fit that description, he told Live Science.

That points to a key way that immunity in mice and humans is different, which was "underappreciated" before, Gustafson said. So when we're comparing these cells in mice and humans, "we're not looking at apples to apples," she said. Scientists now specifically "need to look more into humans, as it's not reflected in animal models."

In people, immune cells' features can also vary across diverse human populations, Gustafson added. We need more data across different populations to get a "true understanding of universal immune health," she said. The K-to-B ratio may be a "novel" clue that can help scientists understand healthy aging, but more data is needed to unpack why and how that ratio is linked to healthy or unhealthy aging.

"This is kind of like the first step to be able to get there," she told Live Science.

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

A bronze signet ring depicting the Lighthouse of Alexandria, a wonder of the ancient world, has been discovered underwater in the Mediterranean off Alexandria, Egypt.

A joint team from the European Institute for Underwater Archaeology (IEASM) and the Egyptian Ministry of Tourism and Antiquities found the artifact in the remains of a palace on the now-submerged island of Antirhodos, marking the first time a signet ring featuring the image of the lighthouse has been found, the IEASM team said in a statement.

The image on the ring is similar to depictions of the lighthouse that have been previously found on coins dating to the second century, representatives of IEASM said.

"The discovery of the ring-signet is even more important as it has been excavated in the legendary palace of the Island of Antirhodos, that once was a centre of power," Franck Goddio, president of IEASM, said in the emailed statement.

The palace was used by Egyptian pharaohs who reigned during the Ptolemaic period (304 to 30 B.C.), a dynasty of rulers descended from one of Alexander the Great's generals. The lighthouse was built on the island of Pharos around 280 B.C. and stood more than 328 feet (100 meters) tall. Some ancient writers, such as Pliny the Elder, considered it among the wonders of the world, and it continued to be used into the Middle Ages, until earthquakes and erosion resulted in its destruction and disappearance beneath the sea.

While the lighthouse was modified over time, it would have had a statue, possibly of Zeus, at the top holding an oil lamp that helped guide mariners.

Whoever was wearing a signet ring could have used it to make an impression on soft materials, such as clay and wax, to create a seal. The discovery of the ring in the remains of the palace at Antirhodos suggests that the palace was used for administrative functions related to the lighthouse, representatives of IEASM said in the statement.

Even though the ring's engraving is somewhat worn, it likely depicts the lighthouse, said Doris Behrens-Abouseif, a professor emeritus of history of art and archaeology at the University of London who has written about the lighthouse but was not part of the research team.

There are "thousands of coins from Alexandria showing a similar depiction of the lighthouse," she told Live Science in an email. Those coins date to the Ptolemaic or Roman (29 B.C. to A.D. 395) periods, she noted.

Behrens-Abouseif added that she wasn't familiar enough with rings from Alexandria to comment on whether this is the only ring that contains this image.

Other scholars told Live Science that they, too, believe that this ring depicts the lighthouse, with two scholars noting that it may feature smoke coming from a lamp at top.

The "most interesting thing about the new signet ring engraved gem is an asymmetrical feature at its peak," which "may depict a plume of smoke from the oil lamp in the hand of the crowning statue," Andrew Chugg, an independent researcher who wrote the book "The Pharos Lighthouse in Alexandria: Second Sun and Seventh Wonder of Antiquity" (Routledge, 2024), said in an email.

Margaret Miles, a professor emeritus of art history and classics at the University of California, Irvine, also noticed the possible plume of smoke. Miles noted in an email that this "ring could have been used as a signet ring by a merchant from Alexandria who used the profile of the [lighthouse] to signal his location in Alexandria. The lighthouse was famous, so it became a symbol of the city."

Research off the coast of Alexandria over the past few years, including the discovery of 22 massive blocks, has revealed more information about the lighthouse, including how exactly it looked, which is helping researchers who are trying to digitally reconstruct it.

Are you a fan of mummies and hieroglyphs? Find out with our ancient Egypt quiz!

A four-legged robot completed a full marathon on a single battery charge, covering 26.2 miles (42.2 kilometers) on a hilly public-road course in South Korea two years ago. Now we know a lot more about how it achieved this record-breaking feat.

The dog-like robot, called RAIBO2, finished the 22nd annual Sangju Dried-Persimmon Marathon in just over 4 hours, 19 minutes. The bot's developers say it's the first quadruped robot to have completed an official marathon-distance event without stopping to recharge. They're commonly referred to as "robot dogs" because the movement of their joints in both front and hind legs resembles that of canines.

The scientists outlined their findings about the robot's feat, which it achieved Nov. 17, 2024, in a study published Sept. 23 in the journal Nature.

This achievement represented a new milestone in overcoming a critical limitation for quadruped robots: endurance. Although four-legged robots can cross difficult terrain that wheeled machines struggle to traverse (like stairs and rugged trails), their endurance has been limited because powering multiple joints while repeatedly lifting and stabilizing the machine's body consumes huge amounts of energy.

"Unlike wheeled robots, quadrupeds continuously expend energy at their joints to support body weight and incur kinetic energy losses during intermittent foot-ground contact," the researchers wrote in the study.

RAIBO2's race was a demanding real-world trial. It took place during the Sangju Dried-Persimmon Marathon, with the bot racing alongside human participants. The route covered two 50-meter [164 feet] elevation climbs, with slopes of up to 10 degrees. Those kinds of gradients put increased strain on the robot's energy resources, stress-testing the bot's battery management capabilities, the scientists said.

RAIBO2 had previously run a 26.7-mile (43 km), GPS-guided route across a flat athletic field, which it knocked out in 4 hours, 40 minutes on one charge. However, an earlier marathon attempt across uneven terrain against other competitors had to be aborted around the 23-mile (37 km) mark after the robot's battery ran out. The robot's developers attributed that shortfall in part to frequent pace changes as the machine attempted to adjust to the pace of nearby runners.

To compensate, the team boosted the robot's battery capacity by 33% and tinkered with the control system, including implementing joint-stiffness control at the actuator. This allowed the bot to soften its leg when it had to absorb an impact or it needed a stable, forceful push-off. After the adjustments, RAIBO2 expanded to a maximum range of 41.6 miles (67 km) on a single charge, albeit on straight paths, according to the researchers.

Another key metric was RAIBO2's total cost of transport — a measure of the energy required to move a body over a given distance, with lower values indicating less energy expended. Researchers reported that RAIBO2 achieved a total cost of transport of 0.25, compared with a human benchmark of 0.37. The researchers said their machine was the first quadruped robot to surpass that figure.

The team attributed that efficiency to several optimizations across RAIBO2's software and hardware. Especially vital were its lightweight mechanical components, which were capable of transmitting kinetic energy from its joints with very little interference. They also credited a low-loss motor-driving circuit and, on the software side, a locomotion policy specifically streamlined to limit energy use. The system was also trained using the team's simulation environment, called RaiSim, which includes models of slopes, stairs and icy roads.

Like many electric vehicles, RAIBO2 can regenerate some battery by capturing kinetic energy, particularly while traveling downhill. That capability allows it to offset some of the energy it expends while climbing, though it doesn't eliminate the extra cost of hilly terrain.

The researchers said RAIBO2 has more than three times the travel range per charge of existing quadruped robots, with a total battery capacity of 2,016 watt-hours. It's in part because of that capacity increase that the team now estimates that the robot could travel up to 15.5 miles (25 km) farther than its marathon stint, up to a total of 41.6 miles (67 km).

That kind of endurance could broaden the roles for quadruped robots in places where wheeled models are impractical, the developers added in the study. For example, they could be useful in disaster zones and mountainous areas, where a sufficiently mobile, high-endurance robot could carry cameras, sensors or communications gear across uneven terrain.

Great Danes and mastiffs rarely live more than a decade, while Chihuahuas can live twice as long. Exactly why big dogs die younger than small ones do has been unclear — but new findings may help to solve that mystery.

The research, published Thursday (Oct. 8) in the journal Science, looked at a chemical code written on top of dogs' DNA. This code, called the methylome, consists of chemical tags called methyl groups, which bind to DNA's building blocks.

Proteins constantly access DNA, loading up the information written in its code and taking that data away to be turned into new proteins for the cell. But these methyl groups can act as tiny roadblocks that stop that process in its tracks.

These groups are one type of "epigenetic marker," which collectively help to control gene activity, and their arrangement on DNA changes predictably as animals age, study co-author Blaise Mariner, a bioinformatician at Arizona State University, told Live Science. Across many studies and species, including humans, scientists have used this data to build epigenetic clocks that track animals' biological ages.

Dogs happen to be a great species for studying aging. Their owners devotedly track what they eat, how they live, and how their health changes over time. So Mariner and his colleagues built epigenetic clocks using DNA in blood samples taken from 894 dogs enrolled in the long-term Dog Aging Project based at the University of Washington.

These samples revealed how the dogs' immune cells aged. These cells patrol the whole body, so "they're a really good measure of systemic aging," study co-author Noah Snyder-Mackler, a genomicist at Arizona State University, told Live Science.

The team found that changes in DNA methylation closely tracked biological aging, in that the dogs with older-than-expected epigenetic ages had a higher risk of death from any cause. Once they looked at how different sizes of dogs aged, clear differences emerged.

"Using our biomarker, this epigenetic clock, big dogs were aging a little bit faster per year of life than small dogs," Snyder-Mackler said.

A key epigenetic change linked to larger body size was the loss of methyl groups at stretches of DNA called transposable elements. Also called "jumping genes," these elements can potentially move around the genome, but the methyl groups help stop them from doing so. But when that methylation is lost, the jumping genes can become too active and end up damaging other genes and causing inflammation, a key process that ramps up with age.

In short, the new data suggests that out-of-control jumping genes may contribute to big dogs' faster aging.

In aging dogs, the team found that some regions of the genome with few chemical tags became more methylated, while other areas that had been choked with methyl groups gradually lost them. Additionally, at least in terms of their epigenetics, dogs' immune cells appear to become more similar to one another as they age. Mariner said this "loss of cell identity" is a key hypothesis for what happens to the body as it ages.

Immune cells are carefully specialized for different roles, such as preventing cancer or killing viruses. As these cells become more similar to one another, they become less able to fulfill their specialized roles, studies suggest.

Humans have bred big dogs for size, and Snyder-Mackler said this push for large body size may have come at a cost.

"Their bodies have to make this trade-off between really rapid growth and maintenance of that," he said, "versus investment in the immune system and integrity of the organism." For now, that idea is a hypothesis, though, as the current study doesn't directly address why big dogs' epigenetic aging has come to be this way.

Now, the team wants to build more informative clocks as the Dog Aging Project recruits more pooches to follow for longer periods. Snyder-Mackler said the team's data currently explains only part of how dogs' epigenetic ages vary. "What we really want to know is, what explains the rest of that variation?" he said.

The team was keen to build predictive models that might help dog owners anticipate their pets' age-related health concerns, Snyder-Mackler added.

What we learn about dogs from these studies may help us understand human aging, too. That's partly because dogs get some of the same diseases we do, but it's chiefly because they share humans' living spaces and environments.

"We're going to start looking, at the molecular level, [at] how these environmental exposures or experiences impact health and aging in dogs, which is going to be directly translatable to humans who are living in those same exact environments," Snyder-Mackler said.

"Most people love dogs," he added. "That means we can get a lot of really good data on them."

Researchers have discovered a roughly 9 million year old tooth belonging to a large, water-loving relative of modern day capybaras in the Atacama Desert of northern Chile. The fossilized molar adds to previous evidence suggesting that it's unlikely the Atacama, one of the driest places on Earth, was continuously dry for the last 40 million years.

The Atacama Desert, possibly the oldest desert on Earth, takes up the northern third of Chile. It's bounded by the Chilean Coast Range to the west, which blocks rain from the Pacific Ocean, and the enormous Andes to the east, which obstruct rain from the Atlantic Ocean. The driest part of the desert's hyperarid region gets less than 0.08 inches (2 mm) of rainfall a month.

Recent research estimates the Atacama's hyperarid core started forming between 47.8 million and 33.9 million years ago, in the Mid- to Late-Eocene, 20 million years before the Andes formed. It suggests the mountain ranges weren't the cause for the desert's aridification, and may have only intensified it.

Capybaras (Hydrochoerus hydrochaeris) ‪—‬ the world's largest rodent ‪—‬ exclusively live close to stable freshwater sources and feed on plants that also require water to grow, so the discovery of an extinct capybara relative (Hydrochoerus Cardiatherium) tooth in the Atacama Desert is very strange.

"Finding a capybara tooth in a marine deposit in what today is one of the driest regions on Earth is just freakish," Priscilla Martinez, a geoscientist at the University of Arizona and co-author of a new paper describing the discovery, said in a statement.

Capybaras are native to South America, although today, they are not found in Chile, where the tooth was unearthed, according to the International Union for Conservation of Nature (IUCN).

The tooth isn't the only clue that the Atacama was a wetter place in the late Miocene. Researchers found it in a layer holding the remains of a shallow marine environment that existed between 7 million and 10 million years ago, according to the statement. And they've also found microscopic pieces of plants, known as phytoliths, revealing that palm trees, grasses, gingers and other flowering plants grew there in what may have been a subtropical forest.

These findings and others are part of a growing body of evidence that the Atacama Desert was once wet enough for crocodiles and freshwater fish to thrive and palms to grow. The new study, published Sept. 5 in the journal Scientific Reports, shows that capybara relatives lived there as well during the late Miocene, which, because they are semiaquatic animals, is further evidence to support the hypothesis of a sporadically moist Atacama.

The researchers aren't sure how exactly capybaras moved into the Atacama Desert. Although there were capybaras in South America at the time, the Andes created an 18,000-foot-high (5,500 meters) barrier between their current habitats and the site where the tooth was found. The researchers theorized that, instead of traversing the mountains, the ancient capybaras migrated along the western coast of South America, following wetlands, rivers and other water sources.

According to Samantha Hopkins, an Earth sciences professor at the University of Oregon who was not involved in the study, it's unlikely the tooth found its way to the site without capybaras living there.

"If you wanted to find a way that this capybara could be here while the Atacama was still as dry as it is today, you'd have a hard row to hoe," she told Live Science in an email, because the size of the tooth makes it hard to transport it long distances. The desert wind couldn't have blown it such a long way, and while large carcasses can float down waterways for miles, "if you're going to invoke a large enough waterway to do this, you've demonstrated that the Atacama wasn't as dry as it is today anyway."

Astronomers have detected the most distant burst of radio signals ever seen: an explosion that's emitting waves of energy from more than 10 billion light-years away.

The event, named FRB 20240304B, is known as a fast radio burst (FRB). Astronomers have detected thousands of FRBs before this. But because these events last only milliseconds, they are extremely difficult to study and their origin stories remain unclear.

In this case, however, astronomers managed to use a radio telescope array and the James Webb Space Telescope (JWST) to chart the event, with JWST narrowing down the precise host galaxy that FRB 20240304B came from. The study, published Thursday (Oct. 8) in the journal Science , sheds more light on a time when the universe was only about 3 billion years old, showing that FRBs arose early in our cosmos' history. The detection more than doubles the previous distance record for FRBs.

The JWST played an instrumental role in the discovery, study co-author Themiya Nanayakkara, a senior lecturer at the Sydney Institute for Astronomy, told Live Science in an email. The email was written in collaboration with study first author Manisha Caleb, a senior lecturer in astrophysics at the same university.

For example, JWST's observations showed that the host galaxy was smaller than expected, was "metal-poor" (had few elements besides hydrogen and helium), and was forming a lot of stars. These characteristics could offer new clues about the environments in which FRBs arise, giving more information about the mysterious events. Researchers suggest that this FRB may have been linked to a magnetar, a highly magnetic star core left after a supernova.

Zooming in with the James Webb telescope

The ancient FRB was initially detected with MeerKAT, an array of 64 radio telescopes in South Africa. Nanayakkara said MeerKAT revealed "both the detection of the fast radio burst and, importantly, a very precise position on the sky."

The researchers knew the FRB was far away because of the large dispersion of the radio signal, but initial searches with powerful ground-based telescopes, "saw essentially nothing; it looked like empty sky," the researchers told Live Science. "The most likely explanation was that the galaxy was simply too faint to be detected in those observations. That is where JWST became transformative."

The science team successfully got time on JWST with a program called Director’s Discretionary Time, which is aimed at time-sensitive observations. The researchers started by using JWST's Near Infrared Camera to trace the radio signal and take a very deep image of the target region.

"Suddenly, there it was: a very faint galaxy almost exactly where we expected the host of the FRB to be," Nanayakkara said. The researchers then used JWST's Near Infrared Spectrograph to obtain a spectrum (wavelengths of light broken into different chemical signatures), which showed hydrogen and oxygen.

"These spectral features act like fingerprints: because we know the wavelengths at which they are produced in the laboratory, we can measure how much they have been shifted by the expansion of the universe," Nanayakkara explained. "That gave us a very precise redshift of about 2.15. We are therefore seeing this galaxy as it was when the universe was only around three billion years old, so roughly one-fifth of its current age."

Because the host galaxy is fairly young, it supports the idea that at least some FRBs are generated by magnetars, which are more likely to appear in spry galaxies where intense star formation is occurring, the team said.

The team plans to continue hunting for FRBs with JWST.

"We do not know what the sources will be yet," Nanayakkara said, as that depends on what pops up in the sky and is spotted by ground-based radio telescopes. "Once our radio telescopes find and localize a suitable new source, we can trigger the JWST observations. So it is quite exciting, because we really have no idea what we will find when we combine the power of these two types of telescopes."

Long before it became the luminous spiral galaxy we call home, the Milky Way was a sprawling, chaotic swarm of thousands of small galaxies, new research shows.

The findings suggest that in the first 2 billion years after the Big Bang, the region of the universe that would become our galaxy was littered with thousands of smaller galaxies of many sizes and shapes. Over time, these galaxies collided and merged into the single galaxy in which we reside today.

"Looking at these results, it's very clear that the physics happening right after the Big Bang has direct impact on what we see today in the local universe," study co-author Harley Katz, an assistant professor of astronomy and astrophysics at the University of Chicago, said in a statement.

To understand more about the early universe, astronomers build sophisticated computer models that encode the laws of nature to see how the cosmos may have evolved. The new work, which is the result of three years of supercomputer simulations, is the most detailed tracing yet of how a galaxy like ours came to be. It also arrives just as astronomers need a stronger yardstick for what they're seeing in the early universe.

Megatron, the cosmic transformer

The James Webb Space Telescope (JWST) can peer farther into the early universe than any previous telescope, and its discoveries have often defied computer models. For instance, JWST found surprisingly bright early galaxies and a mysterious new class of compact galaxies dubbed "Little Red Dots." These anomalies demonstrate that current computer models need an update to handle the complex physics of the early universe, the researchers said.

To bridge that gap, the scientists built a new suite of supercomputer simulations they call Megatron. By tracing ancient gas, starlight and chemistry from 180 million years to 2 billion years after the Big Bang, Megatron predicts the distinct light signatures of its virtual galaxies, according to the statement. Because JWST collects the same type of spectral data across a similar span of cosmic time, scientists can directly cross-reference the simulation against real observations to pinpoint what the old models are missing, the team said.

The simulation also tracks how the universe's first stars formed, died and forged the essential elements that make life as we know it possible. By comparing the simulation with JWST observations of early galaxies and with the chemical traces left in ancient stars, scientists can better understand how those first stars enriched their surroundings, the researchers said.

"Together, these complementary observations allow us to test competing models of the first stars in ways that weren't previously possible," study co-author Martin Rey, a theoretical astrophysicist at the University of Bath in the U.K., said in a separate statement.

The scientists detailed their findings in one of the six papers the Megatron collaboration published Sept. 30 in The Open Journal of Astrophysics.

Assembling the Milky Way

The team's simulation begins 180 million years after the Big Bang, when the universe is devoid of stars and galaxies and holds only pristine gas. As the next 2 billion years pass,, the model captures how the very first stars light up the dark universe and kick off "cosmic dawn," eventually culminating in those stars' violent deaths. As they die, the stars spread newly forged heavy elements such as carbon, oxygen and iron into the surrounding gas, laying the building blocks for future stars and planets.

The simulation ends 2 billion years after the Big Bang, but the Milky Way's mergers continued long after this point, and scientists are still discovering traces of the small galaxies that have joined it. The most recent massive merger, with the Sagittarius dwarf galaxy, began more than 6 billion years ago and is still unfolding.

The simulation results help scientists understand how certain physics parameters impact the early universe, and better match up JWST's observations with computer models. But it also highlights areas that need further study.

"But there are also things we're not getting right, which is interesting too — what are the parts we're still missing?" Katz said in the statement. "That can lead you into new directions and new questions."

Megatron team members in the U.K. are now developing the next generation of simulations, backed by dedicated time on the country's supercomputers. Those simulations will include more complex physics, such as active black holes, which JWST has revealed to be surprisingly common in the early universe, the researchers said.

How well do you know our home galaxy? Find out with our Milky Way quiz!

Scientists have recently harnessed artificial intelligence (AI) to build "aging clocks" that aim to estimate a person's true biological age.

While a person's chronological age reflects the number of years they've been alive, their biological age is intended to capture how well their bodily systems are functioning. The idea is that people with older biological ages have a higher risk of age-related diseases ‪—‬ such as cancer, heart disease or dementia ‪—‬ while younger biological ages come with less risk. Some aging clocks even aim to predict people's impending risk of death.

Many aging clocks look at epigenetic markers, meaning chemical tags that bind DNA and change how genes activate, while others measure features such as the pace and pitch of people's voices. But some scientists say we don't know how to use these aging clocks yet, arguing that the tools are useful for studying aging at a population level but not for guiding individual health decisions.

Others posit that the data the clocks are based on is too noisy, and thus, there's potential for drawing faulty conclusions about what they're measuring. They say, for example, that we don't know if the clocks are measuring the downstream effects of aging or its underlying causes. And in any case, we don't currently have any treatments to "wind back" the clocks.

What do you think? Would you use these AI tools to measure your biological age? Let us know in the poll below, and explain your reasoning and additional thoughts about the technology in the comments.

The sea surface temperature in a key section of the central equatorial Pacific Ocean has now surpassed all previous temperatures on record for this region, exceeding 86 degrees Fahrenheit (30 degrees Celsius) for the first time, according to preliminary data released Monday (Oct. 5).

Specifically, these temperatures occurred in the Niño 3.4 region, located between 5 degrees north and 5 degrees south latitude, and 120 degrees west and 170 degrees west longitude. Researchers use this region to monitor the progression of El Niño, the warm phase of a multiyear natural climate pattern that's currently in full swing and steadily intensifying. But how significant is this new record, and could it be a harbinger of increasingly extreme El Niño events in the future?

At this time of the year, sea surface temperatures above 86 F are common in the western Pacific warm pool, a mass of water located northeast of Australia. But the Niño 3.4 region is nowhere near the warm pool and usually has much cooler temperatures. This latest data indicates "an exceptionally warm state for this part of the tropical Pacific," said Jin-Yi Yu, a professor of Earth system science at the University of California, Irvine.

"If the reported daily El Niño 3.4 temperature above 30°C is verified in the observational dataset, it would be an extraordinary record," Yu told Live Science in an email.

Other experts agreed. A Niño 3.4 sea surface temperature above 86 F is a "very significant" new record, Timothy Osborn, a professor of climate science and the director of the Climatic Research Unit at the University of East Anglia in the U.K., told Live Science in an email. Mat Collins, a professor of climate systems and the head of mathematics and statistics at the University of Exeter in the U.K., also called the temperature "very significant" in an email to Live Science.

But it's important to note that absolute temperature is not the standard way of measuring the strength of El Niño, Osborn said. Researchers usually assess El Niño intensity by comparing sea surface temperatures in the Niño 3.4 region with the average conditions there or with sea surface temperatures across the rest of the tropics, with the latter method removing a skew in the data caused by the climate-change-induced heating of oceans globally.

"On those measures, the current event is already close to being the strongest [El Niño] on record and will likely soon exceed previous records given that the event is forecast to strengthen further," Osborn said. "For some measures, it is already record-breaking for the time of year."

"Super" El Niño

El Niño events happen when warm water in the western tropical Pacific Ocean migrates eastward along the equator, toward South America. This boosts global temperatures, triggering heavy rainfall and floods in regions like East Africa, southern China, the southern U.S. and the Pacific coast of equatorial South America, while places such as Indonesia, the Philippines, southern Africa and northern South America experience drought.

"El Nino impacts are greatest across the tropics and in the lands around the Pacific Ocean," Osborn said. "An El Nino with record strength is very significant because it greatly disrupts the atmospheric circulation which controls the weather patterns including patterns of rainfall."

As of Oct. 6, the temperature anomaly in the Niño 3.4 region is 6 F (3.34 C) above average and rising. A typical El Niño increases Niño 3.4 temperatures by a maximum of 1.8 to 3.6 F (1 to 2 C) above average, so the current condition is "exceptionally large," Yu said. "This indicates that a very strong, or what is sometimes called a 'super,' El Niño is developing."

This year's El Niño is being amplified by human-driven global warming, which has increased background ocean temperatures. As a result, it's likely that sea surface temperatures in the Niño 3.4 region will keep rising over the coming weeks and peak in November or December, before declining again in 2027, Collins said.

"The Niño 3.4 anomaly is very likely to remain extremely large and may increase further," Yu said, echoing forecasters' suggestions that it could reach 7.2 F (4 C) by November.

A new kind of El Niño?

The world is on the brink of crossing a critical warming threshold, raising the question of whether the current conditions can be considered a new normal for future El Niños.

While it's likely that future El Niños will be more extreme than past ones, on average, not every El Niño will be record-breaking and as dramatic as the one unfolding now, because these events tend to be very variable, Collins said.

As climate change intensifies, the big worry is that certain regions will be primed for extreme conditions even before an El Niño strikes, Osborn said. For example, regions that are getting drier due to global warming could see catastrophic droughts if they overlap with areas that experience dryness during El Niño events. Likewise, places that are getting wetter could see worse deluges of rain and flooding if they coincide with areas with higher precipitation during El Niños. But that doesn't necessarily mean extreme El Niños are the new normal, he said.

Instead, the location and duration of El Niño events may be transforming, Yu suggested. "In research by my group and collaborators, we have documented changes not only in El Niño intensity, but also in where the warming occurs and how long events persist," he said.

Yu and his colleagues helped to introduce the idea that we are seeing the emergence of two distinct types of El Niño: the eastern Pacific El Niño and the central Pacific El Niño. "Many El Niño events in the earlier observational record were dominated by warming in the eastern tropical Pacific, whereas Central Pacific El Niño events became much more prominent in recent decades," he explained, adding that El Niños have also been lasting longer.

Global warming may be creating a new kind of El Niño by strengthening atmosphere-ocean interactions in the subtropical Pacific, Yu said. If these interactions combine with processes in the equatorial Pacific, where eastern Pacific El Niños emerge, they might trigger unusually strong events with extreme heating in the central Pacific.

"That provides a physical reason to take the possibility of more frequent extreme El Niño events in a warmer climate seriously," Yu said. "But I would distinguish that from saying that every El Niño will become progressively stronger."

Cases of dengue fever are surging in Florida, spurring several counties to declare a state of emergency.

The state has seen 497 reported cases so far this year. Of those, 252, or about 51%, were caught locally, rather than brought to the state by travelers. The Florida Department of Health confirmed one woman's death from dengue fever in early September, marking the state's first known dengue death in almost a century.

Prior to the past few years, most dengue cases reported in Florida were the result of travel. In other words, people caught the disease in other countries and then traveled to Florida, where their case was then diagnosed. At 245, the number of travel-related cases reported this year is not unusually high, Caroline Waddell, a public health researcher at the University of Florida, told Live Science in an email. However, the number of cases caught from local mosquitoes is more than five times higher than at this point in the year compared with any of the previous four years, she said.

Why are local dengue cases especially high this year? Live Science spoke with experts to find out.

A growing global health concern

Dengue fever is caused by the virus Orthoflavivirus denguei, which spreads from mosquitoes to people through the pests' bites; it doesn't spread from person to person. Aedes aegypti and Aedes albopictus mosquitoes transmit the virus to humans, and the same species can also carry the viruses behind yellow fever, Zika and chikungunya.

About 100 million to 400 million dengue infections happen annually worldwide, with about 800 cases reported in the U.S. historically, although that number has increased recently. Only about 1 in 4 people exposed to the dengue virus develop symptoms, which can include fever, headache, body aches, nausea and rash. About 1 in 20 cases become severe, and immunocompromised people, children, older adults and pregnant people are especially susceptible to these serious infections.

Severe symptoms can include abdominal pain, vomiting, difficulty breathing and bleeding of the gums or nose. The most severe forms of the infection can lead to leaky blood vessels, severe bleeding, shock, organ dysfunction and death. There is no specific treatment for dengue, so care focuses on managing symptoms and maintaining patients' vital signs.

Dengue has escalated as a global health concern in the past few decades. Between 2000 and 2019, global cases of dengue increased tenfold; between 1990 and 2021, dengue-related deaths doubled. Scientists say this surge is likely driven by climate change, since rising temperatures expand Ae. aegypti mosquitoes' range, in turn exposing more people to the insects' bites. Plus, warmer conditions speed up mosquitoes' life cycles and the dengue virus's replication rate, thereby boosting transmission.

International travel also factors into these rising case counts. In 2023, dengue spikes around the world were attributed to the resurgence of global travel following the COVID-19 pandemic.

Zooming in on Florida

As the global picture has worsened, dengue cases in the U.S. have also increased.

Nearly 3,800 cases were reported in 2024 ‪—‬ an increase of more than 300% above the annual average for the previous 10 years. The uptick was tied to a rise in travel-associated cases, reflecting the wider global surge, as well as to warming temperatures that brought dengue-carrying mosquitoes to new regions of the U.S.

Each year, Florida experiences dengue outbreaks in the southernmost parts of the state, such as Miami and the Florida Keys, Panpim Thongsripong, a disease ecologist at the University of Florida, told Live Science. Historically, outbreaks in Miami typically totaled around 50 or fewer cases. But then a 2019 outbreak resulted in over 200 cases, and from 2022 to 2024, outbreak totals have ranged from about 500 to 675 cases.

The outbreak currently unfolding in Florida centers on Hillsborough County, which is farther north and includes Tampa. This is unusual, Thongsripong said, as this region of the state normally sees just a few sporadic cases. Hillsborough County has reported 223 of the state's 252 locally acquired cases this year, and it's where the one dengue-related death took place.

Florida's health department regularly traps mosquitoes and tests them for viruses. So far this year, 20 pools of mosquitoes have tested positive for dengue across seven counties, and 19 of those positive pools were sampled from the greater Tampa area. In 2025, only four mosquito pools throughout the state tested positive, and in 2023, one mosquito pool did.

"Finding positive mosquito pools is rare in Florida because dengue is not endemic to the state," said Keira Lucas, deputy executive director of the Collier Mosquito Control District. "In many ways, it can be like looking for a needle in a haystack," she told Live Science.

Routine mosquito trapping is a relatively inefficient method for detecting viruses, though, Lucas said. As such, detecting dengue-positive mosquito pools may indicate that a large amount of transmission is already unfolding. "Since approximately 75% of dengue infections are asymptomatic, the virus can circulate within a community without being readily detected for some time," Lucas explained.

In addition to Hillsborough, neighboring Pasco and Pinellas counties have declared local states of emergency over dengue.

An unlucky combination of factors

So what's driving the unusual dengue activity this year?

In the past, Florida's local dengue outbreaks tended to be concentrated in the South, which saw moderate rainfall, warmer temperatures and more travel-related dengue cases compared with the rest of the state, according to a 2022 study in the journal Insects. With the outbreak concentrated farther north this year, that could suggest changing climatic patterns are making additional parts of the state especially hospitable to mosquitoes and the virus. That wouldn't necessarily explain why Tampa is seeing more local cases than Miami this year, but it could nonetheless be a factor in the overall trend.

For the virus to persist in local mosquitoes, dengue still needs to be reintroduced periodically through travel-related cases. Because the virus is not yet endemic to the state, it doesn't regularly circulate in local mosquitoes; however, a somewhat predictable "dengue season" has been emerging that coincides with upticks in international travelers carrying the virus to Florida.

This year, though, the high number of locally acquired dengue cases suggests a shift from predominantly imported infections toward outbreaks spurred by local Florida mosquitoes. Scientists hypothesize that climate change could increase local transmission in Florida even more in the future.

This year, Florida has also been enduring its most intense drought in over a decade. In theory, that might be expected to limit mosquito populations because the pests need water to breed, Lucas said. However, when it's dry, people tend to run their sprinklers more, creating mosquito breeding grounds when puddles form or containers fill up, she noted. This could bring mosquitoes closer to people, as it creates opportunities for them to breed.

Ae. aegypti mosquitoes are especially well adapted to living alongside humans, as they prefer to breed in human-made containers. Droughts can also drive dehydrated mosquitoes to bite more as they hunt for fluids.

"It's almost like an unlucky [combination]," Thongsripong said. "Everything coming together at the right time and right place, and boom, you have the conditions for an outbreak to occur."

The true number of dengue cases may be even higher than reported, Waddell said. The cases captured in the data include infected individuals who went to a doctor to get tested. Because many infections are mild or asymptomatic, additional people may have contracted the virus but never got counted.

What can be done

It's too early to definitively say what factors have increased Florida's dengue cases this year, Thongsripong said, as scientists are still gathering information. Despite the unknowns, she thinks the health and housing infrastructure in the U.S. will stop dengue from becoming too dangerous here.

To get dengue under control, it's key for government-level mosquito control efforts to coordinate and for the public to be aware of the virus, Lucas said. The mosquito control district coordinates with the health department for the latest data to best target where to spray larvicide, which kills mosquito offspring before they can bite people, she said.

It's important for people to use mosquito repellent when going outside, Thongsripong said, as well as to empty water from objects that can collect water and become a mosquito breeding ground, such as pets' water bowls, plant saucers, buckets or discarded tires.

Due to this year's strong El Niño, Florida is expecting a rainier winter, which could mean even more mosquitoes than usual, Lucas noted. That, in turn, could fuel additional dengue cases.

"Cases with September onsets are still being reported," Waddell said, "so we're not out of the woods."

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

OpenAI representatives claim that the recent launch of one of its latest models, GPT-6 Astra, marks the beginning of the artificial general intelligence (AGI) era — a hypothetical scenario in which artificial intelligence (AI) can learn and reason like humans. Following very recent claims from technology executives that we've now reached this milestone, how likely is this claim to stand up to scrutiny?

Amid revelations that safety concerns have forced the company to abandon the planned rollout of GPT-6.1 Astra, independent researchers and benchmark creators warn that GPT-6 Astra's record-breaking scores rely on heavy prompt optimization rather than true general intelligence. This comes as experts warn about the risks of future AI systems and AI executives jointly call for a slowdown in AI research.

In announcing the model's release, OpenAI President Greg Brockman suggested that Astra signaled a fundamental turning point in AI evolution. "If we fast-forward a couple years, and we look back and say when was it really that AGI was created, I think it's going to be about this time, and I think it might be about this model," Brockman said during a Sept. 3 news conference marking the launch.

How did the new model perform in benchmarking?

As part of the testing-and-verification process for the new model, OpenAI released benchmark results across a range of tests that measure the capabilities of AI models at various tasks. OpenAI representatives claimed in a statement that the company's new model delivers "state-of-the-art" performance across a variety of fields, including software engineering, the autonomous use of computer programs, mathematics problems, and even scientific research.

Demonstrations, for example, highlighted Astra's ability to generate 3D CAD code; lay out printed circuit boards in CAD (computer-aided design) software; convert digital 3D models into interactive, video-game-style environments; and deploy hosted web applications directly from prompts.

"In our early testing, Astra stood out by approaching legal work the way a discerning lawyer does: it distinguishes documents from established records, surfaces unsupported assumptions, and converts gaps into concrete drafting positions," said Niko Grupen, head of applied research at legal services AI developer Harvey as part of OpenAI’s announcement.

On ARC-AGI-3 ‪—‬ a benchmark designed to measure how efficiently AI systems acquire new skills in novel, abstract environments ‪—‬ Astra achieved a headline score of 99.9%. Independent testing by the nonprofit ARC Prize Foundation, which oversees the benchmark, revealed that Astra surpassed "human action-efficiency" baselines on 96% of levels, taking 51.7% fewer actions per level, on average, than human solvers.

"Not only is this the best model we've ever tested," ARC Prize Foundation President Greg Kamradt said as part of the OpenAI announcement, "but it also represents a meaningful step change in frontier-model performance — not only in its ability to navigate and solve novel environments but also in how efficiently it learns to do so."

How much can we read into test results?

Many researchers have highlighted that Astra's top ARC-AGI-3 performance relied on a proprietary "Provider Adapter" harness, a specialized software scaffolding layer that's inaccessible to rival developers. When tested using the benchmark's neutral Standard harness, this score dropped to 62.7%. ARC Prize organizers also noted that saturating the benchmark does not constitute proof of achieving AGI — emphasizing that its closed, deterministic puzzle environments do not capture the open-ended complexity of the real world.

"When we launched ARC-AGI-3, "we made it clear that saturating the benchmark would not represent 'proof of achieving AGI,'" Kamradt wrote in a blog post. "Therefore, while we believe Astra represents meaningful progress towards generalization, we are not claiming that it is AGI."

Discrepancies in the data were reportedly present even before the official announcement. As reported by Fortune, an embargoed draft provided to news organizations prior to the model's launch listed Astra's ARC-AGI-3 score at 98.6% before it jumped to 99.9% on the live site.

Anka Reuel and Mike Hardy, doctoral researchers in AI at Stanford University, also raised concerns over OpenAI quietly revising several published metrics post-launch, including halving Astra's reported hallucination rate from 4.2% to 2.0% before reverting it.

Speaking to Fortune, Reuel and Hardy attributed the shifting figures to "benchmaxxing" — an industry term that describes the practice of repeatedly rerunning evaluations under subtly tweaked prompts, scaffolds or compute allocations to hunt for peak theoretical scores.

In a 2025 paper published on pre-print server arXiv titled ‘Benchmarking is Broken -- Don't Let AI be its Own Judge’, experts including Princeton doctoral candidate Zerui Cheng and University of Luxembourg postdoctoral researcher Dr. Stella Wohnig warned that such practices create confusion and undermine trust, particularly when official technical documentation omits the basic methodology, making independent verification nearly impossible. Crucially, scores achieved through benchmaxxing reflect idealized performance ceilings under optimal lab conditions rather than practical, out-of-the-box reliability.

According to OpenAI's benchmark data, across specialized domain evaluations, GPT-6 Astra delivered 10% to 20% better performance than both its predecessor, GPT-5.6 Sol, and top market competitors.

Highlights include a 98% score on FrontierMath Tier 4 (v2), which evaluates expert-level mathematical reasoning; a perfect 100% on ExploitBench, which is designed to test offensive cybersecurity capabilities; 95.9% on BenchCAD, which measures an AI's ability to reconstruct 3D objects using CAD code; 57.9% on Terminal-Bench 4.0, which assesses complex terminal-based system administration and software engineering; and 41.4% on AutomationBench, which tests whether agents can complete multistep business workflows across applications.

But independent findings from external AI benchmarking firm Artificial Analysis contradict these results. Astra's score on the independent Artificial Analysis Intelligence Index — an aggregate metric that evaluates general reasoning across frontier models — remained completely flat, at 61, compared with GPT-5.6 Sol, while trailing competitors like Anthropic's Claude Fable 5.1 and Meta's Muse Spark 1.3.

While some benchmark results have seen improvement since the previous generation, Astra underperformed in other tests. Artificial Analysis' testing showed that against GDPval-AA v2 — an economically focused benchmark that measures real-world workplace tasks across 44 occupations — Astra suffered a significant drop in its relative leaderboard ranking compared with GPT-5.6 Sol. Additional regressions were observed in benchmarks that test customer service support, scientific Python programming, and long-context reasoning across large documents.

In terms of overall token use — the metering system that measures the fragments of text or data processed by AI models — OpenAI representatives said GPT-6 Astra achieved dramatic efficiency gains on complex, long-horizon tasks. Findings from Artificial Analysis confirmed that on software engineering benchmarks, Astra was approximately 70% more token-efficient than GPT-5.6 Sol, using roughly one-third the total tokens of its predecessor and one-fifth the tokens of Claude Opus 5.

On professional workplace evaluations like Agents' Last Exam, the new model reduced output token consumption by up to 65% compared with Opus 5, while on general intelligence evaluations, Astra achieved a roughly 10% output token reduction at max effort compared with Sol.

On the other hand, this achievement is offset by a 250% increase in the base API pricing for GPT-6 Astra compared with GPT-5.6 Sol. Token prices jumped from $4/$20 to $10/$50 per million input/output tokens. As a result, Astra ends up approximately 75% more expensive per task than its predecessor on general intelligence evaluations, despite using 10% fewer output tokens. This trade-off has led researchers at Artificial Analysis to question whether AI labs are relying on expensive computational brute force to squeeze out minor gains, rather than achieving true technical breakthroughs.

Does achieving AGI even matter?

With its latest model, OpenAI has placed a stronger emphasis on safeguards and controls. The move follows a series of high-profile incidents in which frontier AI models inadvertently hacked into third-party networks and computer systems as part of routine testing operations, after the models went beyond what humans expected they would do when encountering challenging tasks.

According to OpenAI representatives, Astra did not exceed the scope of its tasks in any security evaluations. For comparison, GPT-5.6 Sol went beyond its authorized parameters in almost 50% of test cases. Hallucination rates have also been reduced significantly, falling to 4.2% on internal tests, compared with 12.2% for GPT-5.6 Sol (with independent testing by Artificial Analysis showing a drop from 92% to 51% at max effort). The model also showed an improved ability to handle ambiguous prompts.

David Wood ‪—‬ chair of London Futurists, a non-profit that hosts discussion groups on emerging technology ‪—‬ argued that beyond individual test results, Astra highlights a fundamental shift in how humans will interact with AI as models move from answering questions to autonomously pursuing complex goals in digital environments.

"The impressive benchmark results matter, but what matters more is the combination of intelligence, autonomy, computer use, and cybersecurity capability," he said in an email to Live Science. "That combination also demands caution. The more useful these systems become, the greater the consequences when they misunderstand our intentions, are misused, or find ways around the safeguards we give them."

Wood suggested that whether Astra can be classified as AGI is less relevant than recognizing the need for AI control and governance to keep pace with technical development.

"The possibility that AI could progress from systems like Astra towards all-round superintelligence makes much greater human vigilance, awareness, and collaboration increasingly urgent," he said.

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The remote south Atlantic island of St. Helena boasts an international celebrity: the tortoise Jonathan, the oldest living land animal. At 194 years old, he has outlasted the expected lifespan for an Aldabra giant tortoise (Aldabrachelys gigantea) by about a century. Now, scientists have identified a range of unique genetic and epigenetic traits that may hold the key to this longevity.

The new research zoomed in on Jonathan's genes, as well as the chemical tags that sit on top of DNA molecules, known as "epigenetic markers." These markers help control which genes are activated and to what degree. The analysis finds that Jonathan's genes associated with mitochondrial function are in great shape, epigenetically speaking, which suggests that they've played a big role in the tortoise's success.

While mitochondrial function has long been linked to longevity and mitochondrial dysfunction has been tied to disease, Jonathan offers fresh insight into that dynamic, said study co-author Stephen Clark, chief scientist of the Kallel Foundation, a nonprofit in Nashville researching drug targets to promote human longevity.

Clark and colleagues published their findings Wednesday (Oct. 7) in the journal Science Advances.

Decoding Jonathan's secrets to long life

Nearly a decade ago, the researchers enlisted Joe Hollins, the vet tasked with Jonathan's care, to collect samples from the record-setting animal. Island authorities forbade the vet from drawing the tortoise's blood, fearing the risk of an infection.

"I didn't want to be the doctor that killed Jonathan," Clark told Live Science. Hollins collected samples via cheek swab instead.

When the samples arrived in the U.S., the researchers sequenced them, but when their computers kept crashing, they discovered that the DNA had been isolated from bacteria in Jonathan's mouth rather than the tortoise's own cells.

Clark "had to go back and beg" for permission to collect more data, he said. The vet then sent cheek scrape samples, which are collected with a slightly different tool than cheek swabs. This time, the DNA was in fact from Jonathan.

The DNA isolated from those cheek tissue samples was more fragmented than it would have been in a blood sample, so the researchers filled in the gaps using an existing reference genome from a 36-year-old Aldabra tortoise named Tank. They also compared Jonathan's DNA to that of a Galápagos tortoise (Chelonoidis abingdoni) named Lonesome George, who was believed to be over 100 years old at the time of his death in 2012.

The team found that, compared to Tank and Lonesome George, Jonathan carried 287 unique variants of genes that had previously been linked to aging-related pathways. These included genes involved in DNA repair and the function of telomeres — the protective tips at the end of chromosomes that tend to shorten with age.

These pathways are also related to aging processes in humans, highlighting a "broader signature of aging" across species, Greer Dolby, an assistant professor of biology at The University of Alabama at Birmingham, who was not involved with the study, told Live Science.

The researchers also looked at epigenetic changes, including DNA methylation, which is when a chemical tag called a methyl group binds the DNA. Certain patterns of DNA methylation can function as a "clock" in that they reflect an organism's biological age; scientists have recently harnessed these patterns in the study of human aging. In this case, the team compared the DNA methylation across Jonathan's genome to that of young and old Aldabra tortoises.

The methylation patterns were more disordered in the older tortoises, reflecting random changes acquired over time, the researchers found. Scientists call this phenomenon "methylation entropy." For most genes, Jonathan's DNA methylation patterns were more disordered than those of the young tortoises. But in a suite of genes tied to mitochondrial function — specifically the bits of those genes that switch them "on" — Jonathan had more organized methylation patterns. That might keep expression of these genes consistent over time, the researchers theorized.

Mitochondria produce energy that cells need to function properly, repair themselves and reduce further damage to DNA. "Keeping the entropy low in these mitochondrial genes, or keeping pristine mitochondria, is likely to be a contributor to longevity," Clark said.

However, the authors couldn't determine a causal relationship — they didn't run any tests that could definitively prove that Jonathon's lack of entropy in these genes explains his long life. Clark argued that additional experiments on a blood sample from Jonathan could offer a more comprehensive view of his genome.

Jonathan's full genetic profile can't be known until after the tortoise's death, when researchers can collect DNA from more tissues, said Vincent Lynch, a professor of biology at the University at Buffalo, who was not involved with the study.

"Some organs are more susceptible to different diseases of old age than other ones, and that happens because mutations accumulate over time," he told Live Science. "We would ideally like to know what those mutations are in those specific tissues."

Furthermore, Lynch questioned whether entropy was a useful characterization of age-related DNA methylation patterns, as methylation can be unpredictable. That said, he agreed that the genes flagged in the study offer helpful data for future work on longevity.

More experiments are needed to determine whether these mitochondrial genes actually play a role in longevity across all Aldabra tortoises, let alone in other animals, or if Jonathan is just an outlier.

"Maybe Jonathan is just really good at being old," Lynch said.

A newly discovered platypus-like creature is the largest-known mammal relative from the entire Jurassic period, a new study finds — although it still only weighed as much as a Chihuahua.

The critter, which hunted salamanders in the freshwater lakes and rivers of what is now Inner Mongolia, China, lived during the mid-Jurassic between 168 million and 163 million years ago. It seems to be the earliest known mammal-type animal that lived a semiaquatic life.

Researchers unearthed the delicate and detailed fossil in 2016, which revealed that the animal likely weighed about 2.2 to 4.4 pounds (1 to 2 kilograms). It was large for a mammal relative during the Jurassic, but its name, Megacauda sungei, was inspired by its tail: Megacauda means "big tail." The discovery was detailed in a study published on Wednesday (Oct. 7) in the journal Nature.

The furry predator had a mix of features seen in modern-day animals, with a broad, flattened tail that marks it as a powerful swimmer, and short hind legs with relatively long feet.

"It's like a chimera," study co-author Zhe-Xi Luo, a paleontologist at the University of Chicago, told Live Science. "The back half of this animal is very much like a platypus. As are the limbs, which would be capable of swimming or digging tunnels in river banks."

But the teeth "are definitely not like a platypus," Luo said. It possessed robust canines and shearing cheek-teeth that would cut and chew meat in a different way from modern carnivorous mammals. "It's a predator with gigantic and very specialized canines," Luo said. "So, it's partly otter-like and partly platypus-like."

A revealing fossil

Tiny bits of vertebrate bones found in what would have been the animal's stomach and the surrounding fossil beds hint that M. sungei dined on salamanders, Luo said.

He added that M. sungei may have sheltered in burrows on land in the temperate plant-filled climate, and hunted in lakes and rivers for fish and invertebrates.

Another notable aspect of the fossil is its throat. Modern mammals, including humans, have hyoid bones in the throat arranged in a "U"-shaped saddle. These help us use throat muscles to swallow chewed food one chunk at a time, instead of gulping down huge bites or whole prey. The structures also enable babies to suckle their mother's milk.

M. sungei seems to have had the apparatus needed to do this, study co-author Thomas Martin, a paleontologist at the University of Bonn in Germany, told Live Science.

"This is an incredibly important evolutionary innovation," Luo said, adding that this capability is one of the things that helped early mammals diversify into carnivores, insectivores, herbivores or omnivores to take advantage of all sorts of foods.

Finding this in M. sungei suggests that the apparatus needed for suckling milk and swallowing had already evolved by the Middle Jurassic (around 174 million to 164 million years ago), Martin said.

This is before marsupials like kangaroos and placental mammals like primates and bears are thought to have diverged from each other 160 million years ago, after descending from an egg-laying common ancestor that lived approximately 180 million years ago.

"Now we push the history of it back to before the split of modern marsupials and modern eutherian [placental] mammals," Luo said.

"Neonatal suckling behaviour was previously thought of as being a hallmark of advanced mammals, but it now appears to have evolved well before then, in the common ancestor of docodontans and mammals at least 165 million years ago," said Sue Hand, a vertebrate paleontologist at the University of New South Wales in Australia who wasn’t involved in the study.

M. sungei is from an extinct lineage of docodonts, which are relatives of mammals from the dinosaur-dominated Jurassic and Cretaceous periods, living between about 200 million and 120 million years ago.

Docodonts adapted to a wide variety of habitats. For example, there was the Jurassic tree-dwelling shrew-like docodont called Microdocodon gracilis, and Docofossor brachydactylus, a tunnel-digger with shovel-like paws. Luo was also part of the team that described a semiaquatic "Jurassic beaver", Castorocauda lutrasimilis, which lived 164 million years ago.

"It seems that an aquatic lifestyle arose often in early mammal-like species," said Tim Flannery, a mammalogist at the Australian Museum Research institute who wasn't involved in the work.

If anything, the newly described "spectacular fossil" shows that docodonts were wide-ranging during the dinosaur age, Hand told Live Science in an email.

"This very detailed study adds to accumulating evidence that mammaliaforms occupied a wide range of ecological niches long before the evolution of living mammals," Hand said.

A 1,000-mile-long (1,600 kilometers) Martian cloud that emerges and then quickly disappears from the Red Planet's sky nearly every day is even weirder than scientists realized. New simulations suggest that the eerie apparition can only be explained using "exotic physics" that have been theorized but never seen on Earth or anywhere else in the solar system.

The mysterious floating mass, dubbed the Arsia Mons Elongated Cloud (AMEC), frequently emerges above Arsia Mons, a 12-mile-tall (20 km) extinct volcano located in the Tharsis region, just south of the Red Planet's equator. The water vapor cloud was first spotted in 2018 by the European Space Agency's Mars Express orbiter and has since appeared nearly every morning throughout Mars' spring and summer, when increased solar radiation triggers strong surface winds. But it lasts only a few hours each day, before fully evaporating.

The AMEC can stretch up to 1,100 miles (1,800 km) long, around one-twelfth of Mars' circumference. For context, that is roughly twice the length of the U.K. or the distance between New York City and Miami.

Although the Red Planet is no stranger to giant dust clouds and occasional "iridescent streaks" of carbon dioxide, it is almost completely devoid of atmospheric water vapor. That makes it extremely rare for puffy, Earth-like clouds to form there, let alone ones so vast. As a result, scientists have struggled to explain this whacky weather.

But in a new study published Wednesday (Oct. 7) in the journal Nature Geoscience, researchers used Mars Express data to create new simulations in an effort to finally explain the AMEC. Initially, the team struggled to recreate the puzzling phenomenon. But when they abandoned traditional meteorological principles in favor of a more out-of-the-box explanation, they were eventually successful.

"To create the AMEC in our modelling, we found that we needed to include some exotic physics … physics that, while included in textbooks, is treated as theoretical and usually thought not to happen in nature," study first author Jorge Hernández-Bernal, a planetary scientist at the University of the Basque Country in Spain who was affiliated with Sorbonne University in Paris at the time of the study, said in a statement. "Once we included this physics in our simulations, the AMEC emerged just as we hoped."

"Wholly unexpected"

The AMEC is an orographic cloud, meaning it forms as strong winds push water vapor up and over a raised structure, such as a mountain. Similar clouds also exist on Earth, including the "Levanter" cloud, which occasionally forms above the Rock of Gibraltar in southern Europe. However, the Martian equivalent cannot be explained by the same processes that occur on our planet.

On Earth, clouds form via a process called heterogeneous nucleation, in which moist air cools and condenses into ice crystals that form around tiny atmospheric particles, such as dust, salt, pollen or soot. But while Mars has plenty of atmospheric dust, that's not what's happening there.

"For the AMEC, it seems that cloud formation takes place without needing any of this 'stuff' [in the air]," said Hernández-Bernal, who has been studying the AMEC for the past six years. "Water vapour turns directly into icy cloud particles without any middle step. It's akin to droplets of condensation appearing in the middle of a room, rather than on a window."

The researchers call this "homogeneous nucleation" and say it has never been seen before in a planetary atmosphere. "It's wholly unexpected," Hernández-Bernal added.

Other scientists previously predicted that homogeneous nucleation could occur in Earth's upper atmosphere or in the skies above Venus. However, this has been deemed highly unlikely because it requires humidity levels roughly 100,000 times greater than those on our planet's surface.

Given that modern-day Mars is almost completely devoid of water, it may seem unlikely that its humidity levels could reach such lofty heights. However, the Mars Express data tells a different story.

As wind rises up the slopes of Arsia Mons, which is more than twice as tall as Mount Everest, it creates a powerful wave that shoots air into the upper atmosphere at tremendous speed. The researchers calculated that the temperature of this air can drop by up to 54 degrees Fahrenheit (30 degrees Celsius) in just 10 minutes. This not only makes it easy to freeze but also greatly increases the humidity within the wave, allowing homogeneous nucleation to take place, the simulations show.

So where does all this water come from? Some of it is already in the atmosphere, but some likely originates at the summit of Arsia Mons, which is covered with a thick layer of frost, the researchers suggested.

"A big success"

The new simulations mark a big step forward in our understanding of the AMEC and wider Martian meteorology.

"We don't have nearly as much information about Mars' atmosphere as we do about Earth's, so reproducing the AMEC to this degree is a big success for the model," Hernández-Bernal said.

The findings would not have been possible without the Mars Express orbiter, which used three instruments — the Visual Monitoring Camera, the High Resolution Stereo Camera and the OMEGA instrument — to map out how the AMEC takes shape and evolves every day. It is also one of the only Mars spacecraft that can see Arsia Mons in daylight.

"Mars Express discovered the AMEC, has followed up and monitored it for years, and is now helping reveal the secrets of its formation," Colin Wilson, the project scientist for Mars Express, who was not involved in the new study, said in the statement.

The discovery is also a reminder that, despite sharing the same basic principles, weather systems do not behave the same on other worlds as they do on Earth, which could have big implications for solar system exploration and the hunt for extraterrestrial life on distant exoplanets.

"While clouds on Earth and Mars seem to be governed by the same 'rules', understanding this exotic Martian cloud required exotic physics — and this may be true elsewhere in the cosmos," Wilson said.

As the "super" El Niño is predicted to bring heavier storms and flooding to the U.S., experts recommend stocking up on food and other supplies. Floods and other disasters, like wildfires, are on the rise due to climate change, making disaster preparedness essential.

But how prepared are people for a disaster?

Preparedness levels vary; some people keep an emergency kit full of food and first-aid supplies, while others have a planned meeting place designated as a safe space. Having a plan can help people feel better about unpredictable events. But not everyone has thought this far ahead.

Live Science recently asked readers how prepared they are for a natural disaster and what sort of plans or supplies they have on hand. Over 130 people responded to the poll, with 51% of readers choosing "I've got an emergency kit ready for when the unexpected happens."

The comments reflected this majority, as one reader wrote, "We're on the edge of an area at risk for grass fires, so we bought/stocked an RV as an emergency bugout vehicle. Felt extreme initially, less so as time goes by. Gives us 3-5 days of margin before we need to resupply, with food, water and first aid for people and dogs."

Another commenter responded to the rest of the comments, writing, "This is just the begining [sic]. Get a greenhouse, plant food, learn to harvest water, build an outside toilet (for later), learn to be self sufficient. trade with your neighbors. Plant fruit trees, get solar panels and an electric transporation (bike, car whatever). Keep a de humidifier in your home. it's back to the 1930ie[s]."

Do you agree with these readers? Let us know in the comments section.

Astronomers have spotted a never-before-seen type of "phoenix planet" rising from the ashes of a dying alien sun. The discovery, which the scientists say was "completely unexpected," raises hopes that more of these reborn alien worlds could be lurking throughout the cosmos — and may offer a glimpse of our own solar system's fate.

The unnamed exoplanet was spotted circling the white dwarf HS 0209+0832, which is located roughly 270 light-years from Earth. White dwarfs are stellar remnants, sometimes dubbed "zombie stars," that form from the leftovers of massive red giants that run out of fuel before eventually collapsing into shriveled husks. HS 0209+0832 is a particularly young white dwarf, still burning at around 63,000 degrees Fahrenheit (35,000 degrees Celsius), which suggests it made this transition within the past few million years.

Scientists previously discovered some surprising heavy elements within the visible spectrum of HS 0209+0832, which was first captured by the Hubble Space Telescope in the late 1990s. These elements ‪—‬ which included aluminium, titanium and nickel ‪—‬ are not normally found inside white dwarfs, so their presence suggested that something unusual was going on. But until now, there was not enough data to figure out what.

In the new study, published Oct. 5 in the journal Nature Astronomy, researchers took a closer look at HS 0209+0832. Using some of Hubble's updated instruments and data from other observatories, the team captured a more detailed spectrum of the stellar zombie. This revealed a high concentration of additional heavy elements, including zinc and copper, as well as niobium, which has never been seen in a white dwarf before.

The researchers think these out-of-place elements were created during the death throes of the former red giant and later coalesced into a "second-generation" planet around the newly forged white dwarf. They suspect the atmosphere of this hypothetical planet is being stripped by the white dwarf's stellar winds, causing the rare elements to fall back onto the zombie star.

Follow-up observations then revealed a recurring dip in the brightness of HS 0209+0832, suggesting that an exoplanet was repeatedly passing in front of the undead star. Based on the alien world's orbit, which lasts approximately 4.4 Earth days, and the duration of its transits in front of the star, the team predicted that the planet is roughly the size of Jupiter. (Its close proximity to the white dwarf also supports the hypothesis that its atmosphere is being stripped away.)

"Second-generation planets are worlds that form out of the material a star casts off as it dies," study first author Jamie Williams, a doctoral candidate in astronomy and astrophysics at the University of Warwick in the U.K., said in a statement. "They're incredibly rare, and finding one around a white dwarf was completely unexpected. It's a bit like finding a planet that has risen from the ashes of the very star it once orbited."

"Completely unexpected"

This is not the first time astronomers have spotted an exoplanet around a white dwarf. For example, in 2019, some of the authors of the new study previously spotted an alien world surrounding the white dwarf WDJ0914+1914. However, in that case, they were confident that it was a first-generation world that somehow survived its star's fiery end.

But the heavy elements that seem to be falling onto HS 0209+0832 — and the relative lack of other elements common in first-generation planets, such as silicon and iron — suggest that's not what's happened for this recently detected world.

"This pattern of elements is a telltale sign of the 's-process,' a nuclear reaction that builds heavy elements inside dying stars during their bloated red giant phase," study co-author Nicholas Stone, an astronomer at the University of Wisconsin-Madison, said in the statement. "It's a chemical signature no ordinary, 'first-generation' planet should carry, which told us that this new planet was something different."

Instead, the newly detected exoplanet likely formed directly from the material that was shed by the dying red giant after it expanded and before it collapsed in on itself.

Similar phoenix planets have been spotted alongside other stellar remnants, such as pulsars, which form when stars explode as supernovas. However, until now, such worlds have never been seen around a white dwarf.

Rising from the ashes

"What's remarkable about the planet around HS 0209+0832 is that this isn't a planet from somewhere else, or a survivor from the system's birth, it looks like it was built from the very material its own star cast off as it died," study co-author Boris Gänsicke, an astrophysicist at the University of Warwick who also helped to discover the exoplanet around WDJ0914+1914 in 2019, said in the statement. "In a sense, this system has given birth to a new world using the foundations of the old one."

HS 0209+0832 may have once harbored other exoplanets when it was a red giant. But if they existed, these alien worlds likely perished in flames as the dying star ballooned — similar to what experts think will happen to Earth when the sun runs out of fuel and transitions into a red giant in around 5 billion years.

Once the sun has finished bulging, it will turn into a white dwarf too. The new discovery hints that our star could also host brand-new worlds after it has transformed, creating a sort of solar system 2.0.

"Finding this one example raises the question of how many more might be out there and might our own solar system host a second-generation planet formed from the ashes of our sun," Gänsicke said.

However, more work is required to figure out exactly how the newfound exoplanet formed and, as a result, how likely this scenario is. The researchers suspect that another object, such as a lost stellar sibling, may have been required to create the new world.

"Forming the protoplanetary disc in this situation is not easy and helps explain why these planets are so rare," Williams said. "To form a disc of material necessary to birth a planet, HS 0209+0832 likely required a companion star that pulled the ejected material back into orbit, rather than letting it escape."

Have you ever wondered what it's like to be flipped off by an orangutan or seduced by a mantis? Well, wonder no more, thanks to the 2026 Nikon Comedy Wildlife Awards.

This photography competition showcases the amusing side of nature, usually by anthropomorphizing it in some way, and features a variety of comical critters from across the globe.

This year, a surprised owl and a brown bear striking a pose are featured among the more than 10,000 entries, with photographers competing for a luxury safari in Kenya's Maasai Mara National Reserve.

Live Science rounded up some of the funniest photos from the 2026 finalists for your enjoyment. And yes, the orangutan and mantis have made it to the finals.

"Are You Kidding Me?"

Here we see a squirrel launching itself at a great horned owl fledgling in Natural Bridges State Beach park in Santa Cruz, California. According to photographer Kevin Lohman, the squirrel knocked the owl off its perch three times.

Our video channels editor, Elise Poore, said this photo really made her laugh. I doubt the owl found it quite so funny. However, great horned owls (Bubo virginianus) do hunt squirrels, so it's no surprise that these rodents can get a little tetchy around the birds.

"Spicy Orangutan"

This "Spicy Orangutan" entry features a male Bornean orangutan (Pongo pygmaeus) raising one finger, giving the appearance that he's flipping off the camera. In the description accompanying the image, photographer Tanner Mansell explained that the orangutan was finishing his meal at the time.

"Even though he was completely wild and just enjoying his food, I couldn't help wondering, 'Does he know what he's doing?'" Mansell wrote.

No, Mansell, he doesn't.

"Ballet Dancer"

This photo of a sparrowhawk (Accipiter nisus) in Dumfries, Scotland, is titled "Ballet Dancer," but to me, the balancing bird looks more like an Olympic gymnast in the middle of a complex beam routine. Either way, perfect form!

"Push Over"

This lion snapshot, taken in the Ruckomechi riverbed in Zimbabwe, is one of many finalists that appear to show animals laughing or joking around.

"#ForTheGram"

Photographer Rosie Barrett was getting shots of three yearling brown bears (Ursus arctos) in Finland when one appeared to strike a pose.

"Pretty sure he knew it was for Instagram..un-bear-lieavable!" Barrett wrote in a description of her photo.

S-bear me.

"Sexy Mantis"

I know what you're thinking: This mantis looks like it's saying, "Draw me like one of your French girls." However, if you can look past the sexualization of an insect, you might notice a pretty neat trick in how the photo was framed.

Half of the mantis's body is hidden behind the leaf. What appears to be a torso and legs are actually the creature's forelimbs, which it uses to catch prey. Photographer Diego Perez explained that he snapped the mantis while documenting wildlife in the proposed Bosques del Araza Regional Conservation Area in Peru, which is currently threatened by illegal gold mining.

"Sea Gangsters"

Here we see a herd of walruses on the coast of Svalbard in Norway. The photo is titled "Sea Gangsters," implying that the walruses look like tough guys. You'd probably feel tough, too, if your tusks (which are actually sabers) grew to around 3 feet (1 meter) long.

"Little Godzilla"

Ten out of 10. No notes. But, in all seriousness, red squirrels (Sciurus vulgaris) are known to grab materials like dried grass and moss to line their nests, called dreys, so maybe this little fellow is working on its home sweet home.

"The Different One"

Sometimes, all a photographer needs is the Maasai Mara, three young giraffes and a perfectly placed acacia tree. It's nice that the photographer caught them at a standstill, since these ungulates can run up to 35 mph (56 km/h) in short bursts.

This is just a selection of the finalists. You can see the rest of the contenders in Nikon's 2026 finalists gallery. The winners will be announced Dec. 8.

What do you know about the animal kingdom? Test your knowledge with our animal quiz!

The Draconids, one of the year's most unpredictable meteor showers, will peak this week. Although only a few "shooting stars" are expected, the shower has a history of producing spectacular meteor storms with little warning.

The Draconid meteor shower takes place Oct. 6-10 each year, peaking on Oct. 8-9, when around 10 "shooting stars" per hour are expected. Whereas most meteor showers are best seen after midnight or during the dark hours before dawn, the best time to view the Draconids is in the evening, according to Timeanddate.com, making it one of the more convenient meteor showers of the year. Just after dark Thursday (Oct. 8) will be the best time to look.

The Draconids are different from most other showers because their radiant — the point from which their meteors appear to originate — is in the constellation Draco, the Dragon, which is highest in the sky in the evening. It's also circumpolar in much of the Northern Hemisphere, so it never sets below the horizon. However, there's no need to stare directly at Draco, because meteors can appear anywhere in the sky.

This year, the Draconid meteor shower peaks at the perfect time of the month for dark skies. Because the new moon occurs Saturday (Oct. 10), there will be no significant moonlight when the Draconids reach maximum activity.

However, the Draconids are notoriously unpredictable; while just a handful of meteors per hour are expected, the shower can sometimes produce huge meteor storms. For example, during the Draconids' peak in 1933, Europe saw 500 meteors per minute, according to NASA, and during the 1946 peak, 50 to 100 meteors were seen per minute in the U.S.

The source of the Draconids is Comet 21P/Giacobini-Zinner, which was discovered in 1900 and orbits the sun every 6.6 years. It was last in the inner solar system in 2025 and will return in 2031.

Each October, Earth passes through streams of dust and debris left along the comet's orbit. When those tiny particles strike Earth's atmosphere, they heat up and vaporize, creating streaks of light in the night sky.

Most observers will probably see only a few Draconids this year, but with a meteor shower this unpredictable, it's always worth looking up. The best way to see the Draconids is with the naked eye, but a good pair of stargazing binoculars or a nice backyard telescope will help you enjoy the feast of fall skywatching events on the horizon. Amazon has great deals on skywatching gear this week, so it's a perfect time to get involved.

The patient: A 65-year-old woman in Michigan

The symptoms: The woman arrived at the emergency room via ambulance and asked to see a psychiatrist for her visual hallucinations. "I'm seeing dead people," she told clinicians, adding that she'd even fired a gun at her hallucinations in one instance, according to a report of her case. (The report does not describe what the hallucinations looked like.)

Despite this reaction to her hallucinations, she was calm and alert during her physical exam, with normal vital signs other than high blood pressure. She reported a history of high blood pressure, diabetes, heart failure and chronic back pain but no prior psychiatric history.

What happened next: Since the woman had no past psychiatric history, doctors opted for a medical assessment before consulting a psychiatrist. A blood test revealed mild metabolic acidosis, meaning her blood was too acidic. A toxicology screen detected high levels of salicylates, a class of compound that includes acetylsalicylic acid, better known as aspirin.

The diagnosis: When questioned, the woman acknowledged that she had been taking over 15 aspirin pills a day for multiple weeks. Each of these pills, marketed for back and body pain, contained 500 milligrams of aspirin.

Upon further questioning, the woman confirmed that she had tinnitus (ringing in her ears), which is a classic symptom of salicylate toxicity. In other words, she'd overdosed on aspirin.

The treatment: Doctors consulted experts at Michigan's poison control center, who recommended intravenous (IV) treatment with sodium bicarbonate (the chemical name for baking soda). This treatment alkalinizes blood and urine, meaning it makes them less acidic. This enables more salicylate to be excreted through the kidneys, allowing the drug to be eliminated through the urine.

After 11 hours of the IV treatment, the woman's blood salicylate levels dropped from 28.8 milligrams per deciliter (mg/dL) to 18.3 mg/dL. Her hallucinations ceased and the tinnitus improved within 48 hours of her arrival at the hospital. She was discharged without having seen a psychiatrist.

What makes the case unique: Aspirin is generally safe when used in doses indicated on the bottle or advised by a person's doctors. However, taking too much aspirin can irritate the gastrointestinal tract, as well as disrupt the activity of parts of the nervous system.

At high enough doses, salicylates can stimulate part of the brain called the medulla, which regulates breathing. This results in hyperventilation that causes the body to lose too much carbon dioxide, and at first, the blood becomes more alkaline. This process is known as respiratory alkalinosis.

However, salicylates also disrupt metabolism, leading to metabolic acidosis from a buildup of lactic acid in the body, as the woman experienced. When metabolic acidosis overwhelms the respiratory alkalinosis and causes the blood to acidify, organ damage can occur. These metabolic effects may also explain the tinnitus, as it drives increases in arachidonic acid that stimulate receptors in the inner ear.

The woman's daily intake of roughly 75 milligrams of aspirin per kilogram of body weight was about half the typical dose associated with acute salicylate poisoning. However, it was still a large amount to take every day for weeks, and older age is also a risk factor for severe outcomes of acute salicylate toxicity.

The authors of the case report noted that although she had tinnitus, she lacked many other hallmark symptoms of salicylate overdose, such as nausea and fever.

To the clinicians, the woman's case served as a reminder that long-term aspirin toxicity may result in different symptoms than acute poisoning does. In past case reports, other patients with chronic salicylate toxicity have also reported visual hallucinations. But that potential symptom is not as well understood as more common symptoms like tinnitus.

The case report authors added that longer-term exposure to aspirin may be associated with more neurological symptoms because chronic exposure increases the odds of the drug crossing the blood-brain barrier — a gatekeeper that allows only certain substances from the blood into the brain. They added that doctors should consider poisoning, including salicylate toxicity, for patients with psychotic symptoms with no clear cause.

For more intriguing medical cases, check out our Diagnostic Dilemma archives.

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!

Emerging treatments aim to reverse or stall signs of aging in the body and thus cut the risk of age-related diseases. One of those signs is an accumulation of "zombie cells" — damaged cells that spew harmful substances rather than dying off and getting cleared away by the immune system.

Some scientists are designing treatments aimed at killing those zombies directly. But what if we instead helped the body's cleanup crew get rid of them?

"I think rejuvenating the immune system could rectify a lot of problems," said Roel de Maeyer, an immunologist at the University of Oxford. "We know hospitals are full of older people suffering from infections that younger people don't need to go to [the] hospital for."

The aim of these rejuvenating therapies would be to help people live healthier for longer, he told Live Science.

How do cells turn into zombies?

The immune system constantly gets rid of old, dysfunctional and dead cells to keep tissues healthy, but that cleanup gets less effective with age.

When cells die, they display proteins on their surfaces that act as "eat me" signals for immune cells, called macrophages, to engulf and destroy them. However, some cells refuse to die and instead become senescent. These zombified cells can lurk in tissues for years, releasing chemicals that drive inflammation and damage.

Senescent cells can form due to DNA damage from oxidative stress, radiation, or even normal cell division. Cells lose bits of DNA each time they make copies of themselves, and they have intricate mechanisms to decide when it becomes a "bit too dangerous to keep dividing," de Maeyer said. If a cell can no longer divide, it usually undergoes a process called programmed cell death or becomes senescent, he said.

Senescence can be beneficial in some contexts; it helps heal wounds, for example. But an accumulation of senescent cells is linked to damaging inflammation and impaired organ function.

"If there are many senescent cells in a tissue, that's usually a bad sign," de Maeyer said. The number of senescent cells goes up with age and is linked to many age-related conditions, such as heart disease and dementia.

Slaying zombies

Studies in mice have shown that using drugs to kill senescent cells can reverse inflammation and some signs of cellular aging. These drugs, called senolytics, force senescent cells to enter programmed cell death, thus reducing their numbers, said Jure Povsin, a biochemist at the Max Planck Institute of Biochemistry in Germany. This ultimately reduces inflammation and improves tissue function, he told Live Science.

But while senolytics can help rid the body of zombie cells, it's not clear why the immune system fails to eliminate senescent cells in the first place. To find answers, scientists began looking at macrophages, the cells tasked with devouring dying cells.

Research pointed to a receptor on macrophages called EP2. One study, published in July in the journal Science, found that old macrophages have a greater number of these receptors and cannot eat senescent cells effectively.

Genetically deleting the EP2 receptor in lab mice restored the macrophages' function and reduced the number of senescent cells. Compared with normal mice of the same age, the genetically tweaked mice showed less cognitive decline, muscle loss, cardiac dysfunction and systemic inflammation.

On some of these metrics, such as the ability to remember familiar objects, the modified mice were comparable to younger mice.

A problem with energy

Why is the EP2 receptor at the root of this problem? Scientists found a clue in a huge study of older adults.

A molecule called PGE2 plugs into the EP2 receptor. It's a type of prostaglandin — a molecule that helps cells communicate during stress and injury and contributes to fever, pain and swelling. Drugs such as ibuprofen reduce inflammation by blocking prostaglandin production.

In 2001, a large study uncovered a connection between these prostaglandin-blocking drugs and Alzheimer's disease: People ages 55 and older who routinely took the drugs for at least two years had a lower risk of developing Alzheimer's than nonusers did. The study could not prove that the drugs directly prevented the disease, but it added to growing evidence that inflammation related to EP2 activity plays a role in Alzheimer's.

This caught the attention of Dr. Katrin Andreasson, a neurologist at Stanford University and co-author of the recent Science study.

"I thought, 'Wow, this is interesting,'" she told Live Science. "I wondered if there's a connection."

Andreasson and colleagues had an important breakthrough in 2021: They found that aging macrophages had higher levels of the EP2 receptor and that increased EP2 activity disrupted how the cells used their energy. Instead of burning glucose to produce energy like young macrophages do, these cells stashed it away.

As a result, the cells could not do their job properly, as "gobbling up cells requires a ton of energy," Andreasson said. Blocking the EP2 receptor restored normal energy use in the macrophages. In old mice, it also led to reduced inflammation and better scores on cognitive tests, compared with mice in which EP2 activity remained high.

Making senescent cells vulnerable

In their recent study, Andreasson's team uncovered another consequence of aging: Old mice accumulated many senescent neutrophils, a type of short-lived immune cell that acts as the body's first line of defense against germs. Neutrophils normally die within days and are then cleared away, but with age, they become more prone to senescence and accumulate.

"I think that's kind of an odd concept because they're [usually] very short-lived cells," said de Maeyer, who was not involved in the Science study. "Neutrophils are inherently quite inflammatory, so wanting to clear them from tissues is very valuable."

Old mice have too much EP2 activity in their macrophages, and that means they can't get rid of these neutrophils, Andreasson's team found. That may be why deleting EP2 seems to have anti-aging effects in multiple organs, they concluded.

But increased EP2 activity is just one side of the story; some studies suggest that zombie cells actively suppress macrophages' ability to eat them. They do this by using a tricky protein called CD47.

CD47 is a "don't eat me" signal that stops macrophages from destroying cells, Povsin said. "It signals that the cell is healthy, alive and doesn't need to be eaten."

However, that signal gets amplified in senescent cells, Max Planck researchers showed in a 2023 study. That means that, when macrophages interact with senescent cells, macrophages' function becomes impaired. Afterward, they even lose the ability to engulf dying, nonsenescent cells. This allows a ton of cellular debris to accumulate.

So, rather than just blocking EP2, it could also be beneficial to reduce that "don't eat me" signal in senescent cells, this research hints. But CD47 is found on all living cells, so scientists can't just deplete its numbers across the body.

A specific enzyme modifies CD47 on senescent cells, and in the 2023 study, blocking the enzyme helped spare macrophages from the effects of CD47. Therefore, blocking the enzyme could be a more selective approach to weaken the "don't eat me" signal on senescent cells, Povsin said.

A long road to treatments for people

Translating these ideas into anti-aging treatments for humans would be a major success in the science of aging, but experts say there are significant problems to overcome.

Although blocking EP2 had consistent results in lab mice, the rodents are genetically identical and bred in controlled environments. Humans are inherently more variable in their biology and the environmental factors they're exposed to, introducing confounding factors that would need to be addressed, de Maeyer said.

Additionally, in clinical trials, EP2-blocking drugs have so far been explored as cancer treatments, but they are "underexplored" in the context of aging, he added.

Drugs targeting CD47 are in an even earlier stage of development. In the 2023 research from Max Planck, the team used both human and mouse macrophages in their experiments, but the approach has not been tested as an anti-aging treatment in living mice or humans yet.

In 2020, de Maeyer's team used a different strategy to rejuvenate macrophages in older adults. They blocked a protein called p38, whose activity was high in the macrophages of older adults. Blocking the protein helped macrophages better recognize and eat dying cells in specific tests.

In that study, the team gave adults ages 65 and up an experimental drug called losmapimod to block p38. Although it helped restore their immune cell function, it was not suitable for long-term use because it caused liver problems in later trials, de Maeyer said.

In their mouse studies, Andreasson's team was able to block EP2 without causing any negative side effects. But she cautioned that we "really need to drill down on the research and confirm all this stuff in humans."

"The next logical step," she said, "would be to figure out how to inhibit this receptor in a safe way."

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

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The animal kingdom has influenced several robot designs over the years to solve fundamental challenges in propulsion and movement — from horses to insects. Now, frogs are the latest creatures to inspire roboticists.

As seen in a new study published Sept. 18 in the journal Science Advances, researchers probed how twisting bent elastic rods could produce a "snapping motion" that enabled a small robot to hop or swim. This mechanism could be used to improve robots with limited power and ones that need to traverse rough terrain and even water, the scientists said in the study.

They also built a prototype to demonstrate the work. The palm-sized robot weighs just 3.4 ounces, or about as much as a deck of playing cards. It moves about three body lengths per second — launching itself forward with short jumps.

"The broader opportunity is to let the mechanics of the robot do some of the work that would otherwise require larger motors or more complicated control," Xiaonan (Sean) Huang, an assistant professor of robotics at the University of Michigan and co-first author of the study, said in a statement.

"By programming when an elastic structure stores and rapidly releases energy, we can give small robots access to powerful, repeatable motions without continuously demanding high output from the motor," Huang explained. "In the future, this principle could be useful for robots that must navigate cluttered terrain, overcome obstacles, reorient quickly, or operate across both land and water."

Snap movements

When a flexible rod bends and its ends are rotated, it can eventually reach a point where it changes shape to release built-up tension, the roboticists said. However, this change does not always happen in the same way. Some combinations of bending and twisting cause the rod to change shape gradually, while other combinations force it to snap rapidly from one shape to another, with the potential to provide a strong push.

The team used computer modeling and experimentation with a robotic arm to repeatedly deform the rods and find an optimal shape. In this case, they settled on a helix similar to a coiled spring to give the rod its maximum release of energy, the team reported.

With the ideal propulsion mechanism, the team then designed and built real robots that used the snapping rods to hop. They connected these rods to a rotating motor, with the bent rods twisted until they produced the snapping motion. Then, the motor unwound the twist and contorted the rod again.

"Because the design rules depend on the rod’s shape and how its ends are moved, they work across different sizes and scales," Khalid Jawed, an associate professor at UCLA's School of Engineering and co-first author of the study, said in the statement.. "This opens a promising path toward miniaturized robots just a few millimeters in size that turn small motor movements into powerful bursts of motion," said Jawed, whose lab worked on the simulation and robot arm experiments.

The final form of the prototype was a frog-like robot with a pair of snapping rods at the rear of its main body. Tests included hopping over a broad range of surfaces, including solid materials like wood and glass, as well as trickier soft and slippery surfaces that used materials like leather. The scientists also tested the robot outdoors on sand and grass, noting that it could even climb and descend steps and, with paddle attachments, swim.

By using only one of the snapping rods, the team enabled the robot to turn and, with a remote control, navigate a small obstacle course.

Researchers have observed the strongest candidate yet for a "microblazar" — a dazzling object that has long been predicted to exist but never spotted.

Observations of microblazars would give astronomers closer views of black holes emitting powerful jets of energy and help them understand how these extreme objects behave.

Blazars are some of the most energetic objects in the universe. They are a type of quasar — a brightly glowing object fueled by a supermassive black hole stripping material from its host galaxy and then ejecting some of it in powerful, opposing jets of particles and radiation. To qualify as a blazar, one of those near-light-speed jets needs to point directly at Earth. Astronomers have previously discovered smaller versions of quasars, dubbed microquasars, and long theorized that there must be smaller versions of blazars as well.

Now, an international team led by astronomers in Spain, the Netherlands and Argentina has described a microblazar in a study accepted for publication in the journal Astronomy and Astrophysics.

"It is the first time that we have a serious candidate," Josep Martí, an astronomer at the University of Jaén in Spain and first author of the study, told Live Science.

The object, called IRAS 18293-0941, is located in our galaxy, about 12,000 light-years from Earth, and it's hidden behind a veil of dust. It is a binary system that includes a black hole that orbits a hot, gigantic star every 11 days. Matter from the star falls into the black hole, and some of this material is jettisoned into the surrounding environment in two opposing jets. One of those jets flares toward Earth.

These objects, as well as microquasars in general, are tricky to observe, Martí said. "Because of stellar evolution, you need to catch the system at the right time," he added. "The microquasar phase of evolution is very short, and so it is difficult to find one in that phase."

Theorists predicted that microblazars would have special characteristics that should help define them. These features include powerful emissions across the electromagnetic spectrum, rapid changes in brightness (variability), and a hotspot behind them where its opposing jet heats up the interstellar medium in the opposite direction of Earth.

To observe IRAS 18293-0941, the study authors used a variety of instruments ‪—‬ including the Calar Alto Astronomical Observatory in Spain, a network of radio astronomy telescopes called the European VLBI Network, and the MeerKAT radio telescope array in South Africa ‪—‬ as well as archival data from the Very Large Array in New Mexico.

They found that IRAS 18293-0941 has all of the expected microblazar characteristics, except one ‪—‬ variability. Microblazars have rapid variability, which means their brightness changes a lot in a short period, because one of the jets is facing Earth and small changes in brightness are amplified by an effect called Doppler boosting.

Martí said IRAS 18293−0941's lack of rapid variability could be explained by the dense cloud of gas surrounding it, which could smooth out quick fluctuations in brightness.

The researchers are currently investigating whether the observed area behind the microblazar is in fact a hotspot, study co-author Pedro Luque-Escamilla, an astronomer at the University of Jaén, told Live Science.

Even with one of the expected features missing, this object is a promising candidate for the first known microblazar. "The claims and the results of the paper are sensible and there are no questionable hidden assumptions," Kinwah Wu, a theoretical astrophysicist at University College London who was not involved in the research, told Live Science in an email. "The source in this paper had shown signatures of interactions between the jets and the ambient material, which naturally leads to [particle] interaction."

Svetlana Jorstad, a senior research scientist at the Institute for Astrophysical Research at Boston University who was not involved in the research, told Live Science in an email that the new study was "very interesting, important and comprehensive."

Itumeleng Monageng, an astronomer at the University of Cape Town who was also not involved in the research, added that the team's observations "presents a previously overlooked mechanism for generating some of the highest energy emissions observed."

Microblazars "may power some of the universe's most energetic processes," Monageng told Live Science in an email.

Martí, J., Luque-Escamilla, P. L., Marcote, B., Abaroa, L., Aguasca-Cabot, A., Combi, J. A., Romero, G. E., Paredes, J. M., García, F., Fogantini, F., Saavedra, E. A., Del Ser, D., & Van Den Eijnden, J. (2026). A Galactic microblazar as a potential accelerator of ultra-high-energy particles. Astronomy and Astrophysics. https://doi.org/10.1051/0004-6361/202661105

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

Archaeologists have unearthed evidence that men, women and children were subjected to violence within their communities in ancient Scandinavia — and that these victims were buried in unusual places, such as pits or wells or under a family's house or yard.

During the Scandinavian Iron Age and Viking Age (from roughly 500 B.C. to A.D. 1050), violent encounters between individuals and communities steadily increased, resulting in archaeological evidence of elite warrior burials and mass graves from battles.

To better understand the context of violence in the Iron and Viking ages, researchers analyzed 192 human bones from people buried in domestic areas at settlements in what are now Denmark, Norway and Sweden.

"The fact is that not all bodies ended up in monumental burial mounds in the Iron and Viking Ages, or even in more modest urnfields and cemeteries," the researchers wrote in a study published Sept. 28 in the Journal of Archaeological Method and Theory. Rather, some bodies — or pieces of bodies — were placed in postholes, pits, floors, wells, houses, yards and feasting halls.

The archaeologists discovered that at least 12 of the individuals had sustained a violent injury around the time of death. Half of those cases involved head trauma, while four people suffered multiple injuries. Most of the victims of violence were adult males, but there were two females and a child as well.

In one Iron Age house in Denmark, built sometime between 500 and 1 B.C., archaeologists discovered a frontal bone from the skull of a child who died between the ages of 2 and 4 years old.

"Our DNA analyses show that it is a small boy who has been cut with a sword," study first author Marianne Hem Eriksen, an archaeologist at the National Museum of Denmark, said in a translated statement. "The child's skull was placed on the floor of a house where people continued to live. This means that someone has walked over a child's skull day after day."

Radiocarbon dating revealed that the child's skull is significantly older than the house itself, by as many as two centuries, suggesting the bone may have been kept for some time before being placed in the house floor, according to the study.

At a Viking Age site dated to around 750 to 1050, archaeologists found a young woman's skull in a well near a cluster of four small houses. "The woman's skull bore traces of blows and was buried in a well," Eriksen said. She may have been cut or slashed with a sword or ax and, like the child, her bones may have been kept for a significant amount of time before being buried in the well. "These glimpses of lives lived from the past show how fascinatingly different people must have thought about life and death," Eriksen said.

And at the Viking Age site of Gammel Lejre, a royal feasting hall that many experts consider to be the inspiration for the epic Old English poem "Beowulf," archaeologists found the burial of a man whose skeleton bore numerous blunt force injuries, several of which had healed, and which attested to a difficult and likely painful life. His skeleton was discovered directly south of the feasting hall.

The study of bones in domestic areas "opens up a completely new understanding of Iron Age society, of the occurrence of violence and of the handling of the dead," Eriksen said. "The results show a much greater complexity in the everyday life and world of imagination of the time than we often attribute to Iron Age people."

But it is unclear exactly why these particular people were the victims of violence and why they were buried in such unusual ways. One possible scenario, the researchers wrote in the study, is that these were victims of violent domestic encounters rather than warfare. Their deaths may also have been the result of socially acceptable corporal punishment or some form of aggression within the community.

Given the increase in social inequality and rise in violence in the Iron and Viking ages, the researchers suspect that precarious community members may have been targeted.

"Not all lives were equally grieved and commemorated in the Iron and Viking Ages of Scandinavia," the researchers wrote. "We may question whether some lives were already considered disposable."

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

Rosalind Franklin, whose photographs of the molecular structure of DNA led to a 1962 Nobel Prize for three other scientists, knew that her famous images held the secret of the double helix, new research suggests.

An examination of archival material reveals that Franklin's Photograph 51, which was taken in May 1952 and later published to show the double-helix structure, was specifically taken for the purpose of publication — not, as some narratives have held, an experimental shot that Franklin believed was insignificant. The new research revealed that Photograph 51 was a new exposure of a sample Franklin had already photographed. She started Photograph 51 the same day she saw that photograph, Photograph 49.

"She took it because she wanted to get a really refined version," said study co-author Alistair Sponsel, a historian of science at the Science History Institute in Philadelphia. Making the effort to take a better photograph of the same sample is "a sign she knew she had something really important on her hands," Sponsel told Live Science.

Francis Crick, James Watson and Maurice Wilkins shared the Nobel Prize in Medicine for the discovery of the double-helix structure of DNA in 1962. As Watson told it in his 1968 autobiography, "The Double Helix: A Personal Account of the Discovery of the Structure of DNA," Franklin's photographs were his "aha" moment: "The black cross of reflections which dominated the picture could only arise from a helical structure," he wrote.

Watson further implied that Franklin was a laboratory automaton, good at the X-ray crystallography techniques used to capture the images of the DNA molecule but bad at interpreting her own data. The new archival work, published Monday (Oct. 5) in the Journal of the History of Biology, suggests otherwise.

Franklin's dearth of published notes about Photograph 51 has been used to suggest she missed a major discovery. But Sponsel said her journals show she noted the possible helical shape and rich structural data in her notes for her first picture of the sample, Photograph 49, which she followed up with the more refined image in Photograph 51.

"In Franklin's mind, they were two different types of scientific image," Sponsel said. Photograph 49 was the experimental image revealing exciting new data. Photograph 51 was the showpiece to convey these findings with the most clarity and sharpness possible.

This new understanding of the relationship between the two images, and how Franklin perceived them, is the most important feature of the new work, Sponsel said, which he conducted with molecular biophysicist Brian Sutton of King's College London. The project began when the Science History Institute acquired a new collection of archival material from Rosalind Franklin and her graduate student Raymond Gosling. The two researchers also combed through the archives at King’s College London, where Franklin was working when she took the famous photos.

Sponsel and Sutton think that Franklin's notes and actions reveal why she didn't rush to publish Photograph 51 right away. Her scientific goals, laid out in a report she wrote in February 1952, were to understand the two separate structures of DNA, then known as A and B. Structure B, illustrated in Photographs 49 and 51, turned out to be the double helix that occurs in nature. Structure A is a form DNA takes when it's dehydrated in the lab.

Structure A, when photographed, appeared more data-rich, so Franklin decided to characterize that structure first before studying structure B. But while she did this painstaking work, Wilkins showed Watson her photographs of structure B. The two scientists, together with Crick, then built a detailed model of DNA's double helix and scooped the discovery from under her nose.

Those three men shared the Nobel Prize for the work less than a decade later. Franklin died of ovarian cancer in 1958, making her ineligible for the prize — and leaving her insights to come to light only much later.

Editor's note: This article was updated at 3:23 p.m. ET to fix the caption and subhead, noting that Rosalind Franklin had likely discovered DNA's helical, but not double-helix structure. Also, the top photo is not Photograph 51, but another photo taken by Franklin.

Amazon Prime Day is underway, and we've found some tempting deals on our favorite stargazing equipment at Amazon. The sale ends at 23:59 tonight, Wednesday, October 7, 2026, and we'll keep an eye on the deals so you can keep an eye on the skies.

Fall is a fantastic time to stargaze, with meteor showers, full moons, constellations and planetary oppositions — some of which you can only see with binoculars or a telescope. Shop the best deals on telescopes and binoculars below.

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This eye-catching astronaut photo mosaic shows a rare "sunglint" transforming a snaking reservoir into a giant silver river.

The winding waterway at the heart of this image is a section of Lake Powell in southern Utah. The artifical reservoir starts around 70 miles (110 kilometers) southwest of the town of Moab and ends roughly 60 miles (100 km) northeast of the Grand Canyon in Arizona. When full, Lake Powell holds up to 1.2 billion cubic feet (33.3 million cubic meters) of water, making it the second-largest reservoir in the U.S. — close behind the nearby Lake Mead, which stretches across the Arizona-Nevada border.

Lake Powell is located on the Colorado River, inside a steep ravine known as Glen Canyon. The reservoir emerged in the 1960s, following the construction of the Glen Canyon Dam, which caused water levels to rise by around 200 feet (60 meters) over the next two decades. In addition to generating hydroelectric power, the artificial lake has become a popular tourist destination. (Lake Mead is also located along the Colorado River and was created by the construction of the Hoover Dam.)

This image mosaic, which stitches together several astronaut photos into a single image, was captured during a sunglint, according to NASA's Earth Observatory. This phenomenon occurs when sunlight bounces off a reflective surface directly into the line of sight of an observer in orbit, such as a satellite or an astronaut, giving the object a metallic, mirror-like gleam.

Normally, this effect would be visible only across a small section of the lake. But by combining photos taken as the sunglint moved along the reservoir's length, the entire body of water was illuminated.

The reservoir is named after John Wesley Powell, an explorer and former director of the U.S. Geological Survey, who mapped out Glen Canyon and other parts of the Colorado River in the late 1860s. Powell was particularly captivated by Glen Canyon, which contained a "labyrinth of overhanging cliffs, hanging gardens, sweeping river bends, and natural arches set amidst a backdrop of colorful buttes and mesas," Earth Observatory representatives wrote.

Powell later described his recollections of the canyon. "Past these towering monuments, past these mounded billows of orange sandstone, past these oak-set glens, past these fern-decked alcoves, past these mural curves, we glide hour after hour, stopping now and then, as our attention is arrested by some new wonder," Powell wrote in his 1875 book "Canyons of the Colorado."

Some of the sights that Powell marveled over still exist, including many smaller canyons that branch off the reservoir and are cast in deep shadow. A similar effect is seen in sections of Utah's Green River, a tributary of the Colorado River that has long perplexed geologists due to its ability to flow "uphill."

From above, one of the canyon's most striking geological features ‪—‬ a large, doughnut-shaped depression known as The Rincon ‪—‬ is visible as a dark ring surrounding a bend along one of the widest sections of the lake. This rusty doughnut, which is up to 3 miles (5 km) across, is a former section of the Colorado River that dried out thousands of years ago when part of the canyon collapsed, enabling water to bypass the rocky loop.

However, many of the other wonders that Powell described have been lost beneath the reservoir's elevated water level. These include a side canyon dubbed the Music Temple, which was shaped in a way that gave it remarkable acoustic properties, according to the Earth Observatory.

During periods of drought, when the reservoir's water levels temporarily drop, other lost geological treasures can be exposed. For example, in 2023, researchers found rare fossils from a mammal-like Jurassic creature lurking beneath the lake's high-water line.

In recent years, some environmental groups have petitioned to drain Lake Powell and return Glen Canyon to its former glory as the "heart of the Colorado River," according to Newsweek. Such a change may help to alleviate pressure on the rest of the river, which has lost a significant amount of water in recent decades. But experts told Newsweek that this is unlikely to happen.

See more Earth from space

Mpox is an infectious disease caused by a poxvirus, meaning a virus in the same family as smallpox. The infection was formerly known as monkeypox.

Historically, mpox was endemic to Africa, and the virus consistently spread in the continent's central, eastern and western regions. In 2022, an unprecedented global outbreak spurred the widespread transmission of mpox in places that had seen only sporadic cases in the past.

Today, many countries affected by that outbreak — including Germany, Portugal and the United States — are still contending with local mpox transmission. Here's what to know about the virus, how it spreads and how to prevent infection.

What to know about mpox in the U.S.

Mpox is still spreading at low levels in the United States and may soon be considered endemic to the country. While case counts have fallen dramatically since the peak of the global outbreak in summer 2022, some people are still advised to get vaccinated against the virus.

Who should get vaccinated for mpox?

The mpox vaccine currently used in the U.S. is called JYNNEOS. One dose is about 35% to 86% effective, while the complete two-dose series is 66% to 90% effective. (The effectiveness varies, in part, because some studies include people with HIV and people without HIV, and inadequately treated HIV can undermine the body's response to vaccines.)

The JYNNEOS vaccine is not currently recommended for routine use in the general population because, beyond vulnerable groups, the risk is not high enough to warrant a universal vaccination strategy. The current outbreak is primarily affecting men who have sex with men, and those sexual networks are the primary targets for JYNNEOS vaccination.

However, not all men who have sex with men need to be vaccinated, according to the Centers for Disease Control and Prevention (CDC). Instead, vaccination is recommended for a specific subset of the group, including those who, in the last six months, have had more than one sex partner, have had sex at commercial sex venues, or have been diagnosed with other sexually transmitted diseases.

Nonbinary and transgender people with these risk factors are also recommended to get two doses of JYNNEOS, as are any sexual partners of anyone in the above groups.

Vaccines are also recommended after a suspected exposure to mpox, as they can help prevent or reduce the severity of the infection.

"For those who are eligible and have not yet completed vaccination, now is a good time to talk with a healthcare provider about getting protected," Dr. Demetre Daskalakis, chief medical officer of Callen-Lorde, an LGBTQ+ community health center in New York City, told Live Science in an email.

With the exception of laboratory researchers who work with mpox, people who have received two doses of JYNNEOS are fully vaccinated and do not need a booster, he said. And if a person has caught mpox in the past and recovered, they do not need to get a vaccine, he added.

About the virus

The poxvirus family also includes smallpox, which has been eradicated worldwide. Mpox and smallpox cause some similar symptoms, but mpox tends to be far milder than smallpox. However, the viruses are closely related enough that vaccines designed to prevent smallpox can also protect against mpox.

Mpox was initially named monkeypox because the virus behind the disease was discovered in captive monkeys in Denmark. But monkeys are not the main hosts of the virus in the wild; rodents and small mammals mostly found in West and Central Africa likely are. Health officials changed the name to mpox in 2022.

There are two major branches of the mpox family tree, called clade I and clade II. These clades were historically thought to have very different death rates, with clade I being the deadlier of the two. The case-fatality rate (CFR) of clade I has been estimated to range from 1.4% to over 10%, depending on the outbreak, while the CFR for clade II has been estimated at between 0.1% and 3.6%.

However, as both clades have spread beyond Africa, data suggests that the CFR for clade I may be lower than once thought, said Joel Wertheim, a professor of medicine in the Division of Infectious Diseases and Global Public Health at the University of California, San Diego.

The features of a given outbreak — such as the surrounding health infrastructure, patients' access to timely medical care, and the population's underlying risk factors for severe disease — likely play a big role in determining the virus's death toll, Wertheim told Live Science. In short, rather than being an immutable feature of the virus itself, the CFR is dependent on the underlying health of and resources available to a given population.

How mpox spreads

Mpox can spread from infected animals to humans through the animals' bites or scratches. Additionally, people can get the virus when they come into close contact with animals and/or their bodily fluids during hunting, skinning, trapping, cooking, eating animals or handling carcasses, the World Health Organization (WHO) notes.

The virus also spreads from person to person, primarily through very close contact, including intimate contact during sex. The virus typically enters the body through broken skin, the respiratory tract or mucous membranes (thin tissues found in the eyes, nose, mouth, anus and genitals), spreading via bodily fluids such as spit, mucus or blood. People can also pick up the virus via objects, such as clothing or linen, that are contaminated with the bodily fluids of an infected person.

The virus can spread through small respiratory droplets expelled during speaking or breathing. However, this is thought to be a less-common transmission route than close contact. There is also evidence that asymptomatic spread sometimes occurs, though it's unclear how frequently that happens.

Mpox can spread from mother to baby during pregnancy or birth. This route of infection can result in pregnancy loss, stillbirth, death of the newborn, or complications for the mother.

Symptoms of mpox

Symptoms of mpox typically appear within a week of a person being exposed to the virus, but they can sometimes take up to 21 days to develop. Once they emerge, symptoms last about two to four weeks, although the illness can linger longer in people with weakened immune systems.

Common symptoms include rash (see images), fever, sore throat, headache, muscle aches, back pain, swollen lymph nodes and low energy. Often, mpox rashes first appear on the face and then spread to other parts of the body; however, if a person becomes infected during sex, the rash may instead start around their genitals. The rashes begin as flat, discolored patches of skin and then progress into raised bumps, blisters, and large, pus-filled pimples that eventually scab over and fall off.

Some people with mpox develop painful swelling of the rectum (proctitis), while others have pain and difficulty when peeing (dysuria) or when swallowing.

Mpox rashes can make people vulnerable to bacterial skin infections, which can cause abscesses or other serious skin damage. Additional complications of the illness include pneumonia, infection of the cornea that can cause vision loss, and vomiting and diarrhea that causes dehydration or malnutrition. Mpox can also lead to blood infections, the intense immune reaction sepsis and, rarely, brain infections (encephalitis) or heart inflammation (myocarditis).

Children, pregnant people, and people with weakened immune systems, including from HIV infection, have a higher risk of serious illness and death from mpox.

Mpox prevention measures

Beyond vaccination, other strategies to decrease the risk of mpox infection include washing hands frequently, avoiding contact with contaminated objects and materials used by people with mpox, avoiding contact with other people's scabs or rashes, and using condoms, although they may only reduce, not eliminate, the risk of mpox exposure during sex.

Mpox treatment

Mpox treatment aims to manage a person's rashes and pain while also preventing complications. "Early and supportive care is important to help manage symptoms and avoid further problems," according to the WHO.

There is no antiviral drug approved for use in mpox, although some are available for emergency use in various countries. For example, the U.S. allows the use of certain smallpox medicines for mpox.

Severe mpox infections also may be treated with vaccinia immune globulin intravenous, which contains antibodies taken from the blood of people who were immunized against smallpox.

People who have recently been exposed to mpox can be given an mpox vaccine to reduce the severity of their symptoms or to prevent the illness altogether. This approach is known as post-exposure prophylaxis, or PEP.

"Post-exposure vaccine should be given as soon as possible, ideally within 4 days of exposure; administration 4 through 14 days after exposure may still provide some protection against monkeypox," the CDC states.

Mpox spread across the world in 2022, triggering tens of thousands of cases in countries where the infection was once rarely seen. Although the disease has since fallen out of news headlines, mpox (formerly called monkeypox) continues to circulate. Now, recent data suggests that the viral illness may soon be endemic to the United States, meaning it will circulate in the country consistently.

Previously, mpox cropped up sporadically in the U.S. via travelers who had visited African countries where the disease is endemic, as well as imported, infected animals that spread the virus to people. Cases have fallen substantially since the peak of the outbreak in 2022, but they haven't disappeared. A report published in August found that there were 2,800 cases in 2024 and over 2,500 in 2025, with only a small fraction being tied to travel. Nearly all of the viral samples analyzed were descendants of the strain that sparked the 2022 outbreak. In short, once the virus arrived, it never went away.

"There's no set threshold for what constitutes endemicity of monkeypox virus (MPXV) in the United States," Ryan Standford, an epidemiologist in the Centers for Disease Control and Prevention's (CDC) Poxvirus and Rabies Branch and co-author of the report, told Live Science in an email. "But each year provides further evidence of this transition."

Why is mpox still spreading in the U.S., and what can be done to snuff it out? It's likely that too few people have received two doses of the mpox vaccine JYNNEOS, which together are 66% to 90% effective. But beyond low vaccination, there may be other, less-understood factors that are contributing to the continued spread, experts told Live Science.

"We don't quite know how it's able to persist at such low numbers across the entire country," said Joel Wertheim, a professor of medicine in the Division of Infectious Diseases and Global Public Health at the University of California, San Diego.

At the same time, public health efforts around mpox have dwindled. Without a sustained effort on that front, it's unlikely the disease will be eliminated from the U.S.

"We have vaccines, testing, and a much stronger understanding of the disease than we did in 2022," Dr. Demetre Daskalakis, chief medical officer of Callen-Lorde, a LGBTQ+ community health center in New York City, told Live Science in an email. "Our focus now should be making sure those tools remain accessible, especially for communities that continue to face ongoing risk," said Daskalakis, who coordinated the nation's mpox response during the previous presidential administration.

"People at increased risk should know that mpox has not disappeared."

Who is at risk of mpox in the U.S.?

In the U.S., mpox is predominantly affecting men who have sex with men, and current vaccine recommendations are aimed at this group and their sexual partners. Mpox mostly spreads from person to person through close contact, and transmission during sex is playing a major role in the ongoing spread in the U.S.

Men who have sex with men are not more prone to mpox infection than anyone else. Rather, this transmission pattern stems from the outbreak beginning within a specific sexual network and then continuing to persist within the same network. "The mpox virus rediscovered the same transmission network that HIV had explored decades earlier," Wertheim said.

In a paper published in 2025, Wertheim and colleagues described the transmission dynamics of mpox in New York City during the 2022 outbreak. Similar to how HIV previously spread, mpox triggered "densely connected" clusters of infection. Then, as people in the network gained immunity via infection and vaccination, the cases petered out, decreasing to the persistent trickle we see now.

Wertheim noted that he's not surprised that mpox has remained largely confined to the same network, rather than leaping into new groups.

"From an evolutionary, ecological perspective, it's not hugely successful," Wertheim said. "It's sort of barely hanging on as an STI."

Why is mpox still circulating?

So if mpox is not hugely successful and we have a vaccine, how has the virus continued to circulate? One big factor is that too few at-risk people have been vaccinated, experts said.

The CDC's Center for Forecasting and Outbreak Analytics has crunched the numbers to see what percentage of that at-risk group needs to have immunity to stop mpox transmission, Daskalakis said. The at-risk group is estimated by counting the men who have sex with men who are either taking HIV-preventing medicines or have HIV, and then adding 25% to that total to account for additional people in the same sexual network. That estimate comes out to about 2 million people.

To prevent an outbreak bigger than the one in 2022, between 21% and 35% would have to have immunity through vaccination or a past infection. If over 50% of the group had immunity, that would mean there's a "very small probability" of sustained local transmission, the CDC's modeling suggested.

The current case counts suggest we haven't hit the 50% mark, or a total of roughly 1 million complete vaccinations or past infections.

Data from the August report on mpox seems to support the idea that too few people are vaccinated. That said, information about vaccination status was missing for about 62% of the reported cases. Among the remaining cases, 76% were unvaccinated, while 10% had gotten one dose and 14% had gotten two.

In a subset of 860 cases, the effect of vaccination was striking: Unvaccinated people had nearly 10 times higher odds of hospitalization due to mpox than fully vaccinated people did.

Waning public health attention

It's difficult to pin down exactly how many at-risk people are vaccinated, given that that data is no longer tracked at the national level. "My understanding is that there's no mandatory reporting on mpox vaccination data," Wertheim said.

The CDC previously monitored national vaccination trends, comparing the number of people vaccinated to the overall at-risk population. But that tracking stopped in early 2024, when about 23% of the at-risk population had been fully vaccinated.

Some states, such as New York, previously mandated that clinicians provide their state health department data on the number of people given mpox vaccines. But that reporting is now voluntary, a spokesperson for the New York State Department of Health told Live Science in an email.

Meanwhile, "as the emergency phase faded from public attention, awareness and risk perception may have declined," Daskalakis said. Public health messaging about the virus and vaccination has also waned.

"In recent weeks, HHS [the Department of Health and Human Services] has pulled down some of the plain-language guidance, which is not helpful in supporting messaging," Daskalakis noted. This decision to remove online resources about mpox reflects the federal government's current stance against addressing issues that affect LGBTQ+ health, he told Live Science.

Complicating factors

Although JYNNEOS substantially lowers the risk of severe mpox infection, the vaccine is not perfect, said Rachel Roper, a professor of microbiology and immunology at East Carolina University.

The virus typically enters the body through broken skin, the respiratory tract or mucous membranes (thin tissues found in the eyes, nose, mouth, anus and genitals). The mpox vaccine is good at generating systemic immunity, but it's not as good at guarding against the virus's immediate effects at those mucous membranes, said Roper, who studies poxviruses and vaccines against them.

Because mpox is largely spreading through sexual contact that involves those membranes, that slight gap in protection may also help to explain some of the ongoing spread, she suggested.

Plus, "there are also some data supporting asymptomatic infection as a possible route of transmission, making it more difficult to eliminate local transmission of mpox," Daskalakis said.

What can be done?

Given that mpox is already well established within some sexual networks in the U.S., "preventing endemicity entirely may be increasingly difficult," Standford told Live Science.

And notably, some federal funding cuts could undermine efforts to address mpox, Daskalakis said. These include cuts to Medicaid, mental-health services, housing programs, and HIV services such as the Ryan White HIV/AIDS Program.

Thankfully, looking at current mpox trends, "there's no indication we're returning back to 2022 levels," Wertheim told Live Science. So far in 2026, just under 1,000 mpox cases have been reported, according to the CDC. Month over month, the number of cases is generally trending downward. So, at a glance, the current situation seems better than it was in 2025, he said.

"We sort of seem to be on this razor's edge between endemicity and extinction," he said. "And it's not really clear which way it'll go."

Tipping the virus toward extinction will require healthcare providers to be informed and equipped to spot and manage cases, Daskalakis said. And communicating the importance of vaccination is key.

"One lesson from 2022 was that trusted messengers matter," he said. "We [at Callen-Lorde] work closely with LGBTQ+ communities and make information and vaccination opportunities available in settings where people already receive care." The clinic integrates conversations about mpox vaccination into routine health visits, sexual health services, HIV prevention programs and community outreach activities.

Beyond vaccinating at-risk populations, educating patients about how mpox spreads and how to reduce their risk is also key, Standford noted. "Vaccination coverage is a very important factor, but it is not the only one," he said.

Tipping mpox toward extinction will also require enough investment to maintain the disease surveillance, vaccination, testing and treatment capacity that the federal government helped to expand in 2022, Daskalakis said. The vaccine itself is now commercially available to clinics and in adequate supply, he emphasized.

"The fact that we're seeing ongoing circulation underscores the need for sustained prevention efforts rather than viewing mpox as a resolved public health issue," he said. "Infectious diseases don't disappear simply because public attention shifts."

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

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On Sept. 20, the Antarctic ozone hole peaked at 10.6 million square miles (27.4 million square kilometers), the second-largest size ever observed for this time of the year.

The last time the ozone hole was this big was in October 2015, when it reached a whopping 10.8 million square miles (27.9 million square km), records from the Copernicus Atmosphere Monitoring Service show. So why is the hole in the ozone layer — the shield that protects life on Earth from harmful ultraviolet solar radiation — so big this year, despite other clues telling scientists that it is recovering as expected from the damage human-made chemicals did in the 20th century?

The ozone hole's extent is due to extremely low temperatures in the stratosphere, but it's also possible that we could be seeing a new long-term trend of large, persistent holes, experts told Live Science.

"This year's ozone hole shouldn't be a cause for alarm," Hannah Kessenich, a postdoctoral physicist at the University of Otago in New Zealand who predicted the 2026 ozone hole's extent using satellite data and a computer model, told Live Science in an email. "However, there are still many unanswered questions. It's something we need to keep a close eye on."

Accurate predictions

The latest figures from the Copernicus Atmosphere Monitoring Service indicate that the size of Antarctica's ozone hole has dropped to around 8.9 million square miles (23 million square km) since Sept. 20, making it unlikely that this year will break the 2015 record. However, scientists think the hole will remain large and fluctuate over the next few weeks, Kessenich said.

Antarctica's ozone hole expands every year during the Southern Hemisphere's winter and spring. It typically reaches its maximum size between mid-September and early October, when temperatures are still freezing in the stratosphere and sunlight illuminates the frozen continent for the first time after months of darkness. The hole then shrinks again until late January as surrounding ozone-rich air mixes into the depleted region.

Antarctica's ozone hole was caused by emissions of ozone-destroying chlorofluorocarbons (CFCs) between the 1930s and late 1980s. These chemicals increased concentrations of chlorine in the stratosphere, thereby promoting a reaction that depletes the ozone layer. While countries signed the Montreal Protocol to phase out CFC use beginning in 1989, major CFCs have atmospheric lifetimes of 50 to 100 years, so the hole's recovery could take six decades, researchers estimate.

The ozone layer is particularly vulnerable above Antarctica due to the frigid conditions in the polar stratosphere. Temperatures below minus 108 degrees Fahrenheit (minus 78 degrees Celsius) trigger the formation of high-altitude clouds, whose icy surfaces turn inactive chlorine into its ozone-destroying form in the presence of sunlight. These conditions don't exist to the same extent in the Arctic, because warmer air from the midlatitudes mixes more readily with cold Arctic air than with Antarctic air, thereby blocking the formation of high-altitude clouds.

Changes in the polar vortex

This year's large ozone hole is caused by a very strong polar vortex, a wall of wind that encircles Antarctica and the Southern Ocean in the winter, trapping cold air above the continent. The polar vortex created colder-than-usual conditions in the stratosphere over Antarctica, accelerating the growth of the ozone hole.

Researchers haven't detected an increase in reactive chlorine, but the colder polar vortex has triggered more ozone depletion than usual, said Susan Solomon, a professor of chemistry and environmental studies at MIT who pioneered the study of Antarctica's ozone hole in the 1980s.

This size of this year's ozone hole is most likely a product of natural variability in atmospheric dynamics, Kessenich said.

"We expect ups and downs in the size of the hole from year to year," Solomon told Live Science in an email. "A year or a few years of bigger or smaller holes doesn't tell us anything about ozone loss or recovery; it is just variability. We have to look at the longer term trends, and those metrics continue to tell us that the ozone hole is slowly recovering as expected."

It's also reassuring that the ozone hole, while large, isn't as "thin" as in years past. The hole's extent is calculated based on the area above the continent with ozone values below 220 Dobson units, a measure of how many ozone molecules occur in a vertical column through Earth's atmosphere. Although the area of this year's ozone hole is huge, ozone values haven't dropped as low as in previous big-ozone-hole years, suggesting that there is less ozone "missing" from the hole compared with those years, Kessenich and her colleagues wrote in The Conversation.

But there's also the possibility that we've shifted to a new long-term trend of big ozone holes persisting until late spring, Kessenich said. Changes in global atmospheric dynamics unrelated to CFCs could be making longer-lived holes more likely, she and her colleagues wrote in the article.

There is also some evidence that climate change will strengthen the Antarctic polar vortex over time, which could lead to colder temperatures in the stratosphere and greater ozone losses in the spring, Kessenich said. If this year's polar vortex stays robust, the ozone hole could remain large well into November, she noted.

"It's too soon to tell what has been driving dynamical variability in recent years, but more research is needed," she added.

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You may have watched the moon block out the sun during a solar eclipse, but have you ever seen it do that to a planet? Early Tuesday (Oct. 6) morning, skywatchers across much of eastern North America will have an opportunity to watch a crescent moon pass directly in front of Jupiter. The rare alignment won't happen again for 11 years.

During the event, known as a lunar occultation, Jupiter will disappear behind the moon for up to about an hour before suddenly reappearing. The occultation will be visible before dawn from much of the eastern and central U.S., Canada and the Caribbean, while parts of Africa will experience the event during daylight, according to In-The-Sky.org.

The moon will be a beautiful waning crescent, just 20% illuminated, and Jupiter will shine brightly alongside it. The pair will rise together in the east early Tuesday morning and gradually appear to move closer as the moon travels eastward against the background stars.

When the occultation begins, Jupiter will remain hidden behind the moon for roughly an hour. No telescope will be needed to watch Jupiter disappear and reappear. However, a pair of binoculars or a small telescope will make the event much more dramatic.

Through a telescope, Jupiter will look like a tiny disc rather than a point of light and will take about a minute to disappear completely behind the moon. An easy way to photograph the event is to use a smart telescope to image the moon. (Here's everything you need to know about lunar photography).

Below are the times when Jupiter will disappear and reappear in 10 major cities Tuesday morning, according to the International Occultation Timing Association.

• Chicago: 3:22-4:17 a.m. CDT
• Atlanta: 4:15-5:17 a.m. EDT
• Detroit: 4:16-5:20 a.m. EDT
• Miami: 4:20-5:09 a.m. EDT
• Washington, D.C.: 4:20-5:24 a.m. EDT
• Philadelphia: 4:22-5:26 a.m. EDT
• New York: 4:23-5:27 a.m. EDT
• Toronto: 4:25-5:22 a.m. EDT
• Boston: 4:26-5:30 a.m. EDT
• Montreal: 4:30-5:26 a.m. EDT

Outside the occultation path, Jupiter won't disappear at all. Instead, it will appear to be skimmed by the crescent moon — still a potentially spectacular sight that could produce some amazing photos. From across much of the world, the crescent moon and Jupiter will appear exceptionally close together.

The next lunar occultation of Jupiter visible from North America will occur on Nov. 27, 2037, according to When The Curves Line Up.

The ancient Egyptians practiced human sacrifice around 5,000 years ago, a period shortly after the country was first unified, a new study finds.

In the new study, Roselyn Campbell, an anthropology researcher at Purdue University, re-examined 46 skulls from individuals who were buried near royal tombs that belonged to King Djer, King Djet and Meretneith (a woman who likely ruled Egypt at times), and were built near the ancient sacred city of Abydos. All three rulers lived during the first dynasty, a period that started around 5,000 years ago when Upper Egypt and Lower Egypt were unified into one kingdom. The sacrificed retainers were buried next to the tomb of the king they had served.

Researchers first excavated the royal burial site in the early 20th century. At the time, the excavator, Flinders Petrie, believed that the hundreds of other burials found near the royal tombs contained nonroyals, such as retainers and other people who served the king. Moreover, it appeared that these nonroyals had been sacrificed after the king they had served died, in the belief that they could serve the king in the afterlife.

However, Petrie was unable to identify evidence of fatal skeletal trauma, and his idea that they were sacrificed has been debated ever since. Petrie reburied most of the human remains, but 46 skulls were retained and preserved in the Duckworth Collections at the University of Cambridge.

In the new study, published Monday (Oct. 5) in the journal Frontiers in Environmental Archaeology, Campbell re-examined these 46 skulls using modern forensic techniques and information about the marks that different types of trauma leaves on human skeletons. Campbell found that 18 of the skulls have signs of trauma that were likely fatal — indicating that these individuals were likely sacrificed, according to a statement from the journal. Specifically, Campbell found that many of the skulls had linear fractures, which Petrie had mistaken for damage that occurred after burial.

Linear fractures "occur when the cranium strikes or is struck by a relatively large object with low overall force; because of the cranium's globular shape, the impact of the blow disperses across the cranial vault," Campbell wrote in the study. "While linear fractures are not always immediately lethal, they often cause intracranial lesions and/or hemorrhage, which can quickly cause loss of consciousness and death if surgery [to relieve pressure] is not performed."

Campbell told Live Science in an email that it's difficult to identify the weapon or object that was used. "Based on comparative forensic and archaeological studies, the most likely implement would have been flat and relatively light, probably made out of something like wood rather than stone," she said.

The practice of human sacrifice seems to have ended in the second dynasty of Egypt. Evidence for human sacrifice is limited and seems to be confined mainly to the first dynasty. Petrie theorized that they were retainers to the king based on the fact that some were buried with gravestones that had titles such as seal-bearer which suggested that they served the king.

"As far as we can tell, this particular type of retainer sacrifice seems to have ended with the close of the First Dynasty, which means it [lasted] around two centuries or possibly less," Campbell said.

Jacobus van Dijk, an Egyptologist at Groningen University in the Netherlands who was not involved with the study, welcomed the new research. The "existence of retainer sacrifice in early Egypt has always been controversial and Dr Campbell's research adds an important argument in support of scholars who, like myself, believe this custom was practised in Egypt in the early dynastic period," he told Live Science in an email.

He noted he was surprised at the method used for human sacrifice, because depictions of ritual killing on wooden labels "seems to indicate that the victim was kneeling with his hands tied behind his back being stabbed in the chest with a knife."

Are you a fan of mummies and hieroglyphs? Find out with our ancient Egypt quiz!

Archaeologists have discovered a temple dedicated to the Roman war god Mars in the wooded foothills of the Taunus mountains in Germany. The temple was part of a military settlement that was built in the third century to defend the border of the Roman Empire against Germanic tribes.

The Roman military constructed thousands of forts across Europe, northern Africa and western Asia while expanding the empire, and most of these fortifications had an adjacent settlement, called a "vicus," that was occupied primarily by merchants, families and other civilians.

Since 2024, archaeologists have been excavating the Kapersburg Roman fort and its adjacent vicus in Hesse, roughly 16 miles (26 kilometers) north of Frankfurt, according to a Sept. 25 translated statement from the Hessen State Office for Monument Preservation.

One of the highlights of the current excavation is the unexpected discovery of a Roman temple, Kai Mückenberger, an archaeologist with Hessen Archaeology, a part of the Hesse State Office for Monument Preservation, said in a translated video. "Inside the temple, we found several fragments of a dedicatory inscription," he said. Experts have already translated a portion of the inscription, which mentions that the temple was dedicated to Mars, the Roman god of war.

"We also have the remains of a Mars [statue]," Mückenberger said, as well as a statuette of "a winged figure holding a palm branch and laurel wreath," which is likely the ancient Roman goddess Victoria, a personification of victory in battle.

When archaeologists first excavated the Kapersburg fort near the turn of the 20th century, they discovered that it was built in the early second century, likely under either Emperor Trajan, who ruled from A.D. 98 to 117, or Emperor Hadrian, who reigned from A.D. 117 to 138 and expanded the Roman Empire further into northern England, building Hadrian's Wall. The Kapersburg fort was used by a unit of Roman soldiers and cavalry for about a century and a half, until around A.D. 275.

Although the fort's defensive structures and some of its walls have been visible since antiquity, practically nothing was known about its nearby vicus prior to the excavations that began in 2024, according to Mückenberger.

"The astonishing thing is the exquisite preservation of the archaeological layers that start right beneath the forest floor," Mückenberger said. These layers, which include burnt material, almost never survive in agricultural areas but have been well preserved at the vicus. "This is an incredible learning process and a gain in knowledge for us," Mückenberger added.

During their excavations, the research team discovered far fewer houses than they expected. However, they found much more evidence of craft activities, such as blacksmith pits and ovens for drying wheat and baking bread.

"These are all very technical elements related to local services, indicating that we're in a kind of intermediate area not directly adjacent to the fort itself, but perhaps more like the fort's craft area," Mückenberger said.

The temple and votive statues provide new insight into the Roman world of beliefs on the border of the empire, according to the statement. But when the fort was no longer useful, the Romans leveled the camp and replaced it with residential buildings, the archaeologists discovered.

Mückenberger and his team plan to continue their excavation of the site next year.

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

This colorful ceramic urn depicts a person wearing a jaguar costume and surrounded by human skulls, about to be received into the Maya underworld. The urn once held the bones of an ancestor for their descendants to venerate.

The urn was anonymously gifted to The Walters Art Museum in Baltimore in 2008. According to the museum, the urn is about 17.5 inches (44.5 centimeters) tall and was likely produced in Guatemala by the K'iche' Maya people more than a millennium ago. Originally, the urn probably had an elaborate lid that was tied on with string through the loops near the lip of the vessel, but it is now missing.

The decoration on the urn is striking. A person wearing a jaguar costume splashed with blood — claws and teeth bared — looks out at the viewer from the center of the urn. This individual may be a deceased ruler who is entering the world of the dead, which is symbolized by two pairs of human skulls and the dark figures of two Maya gods of the underworld. Behind the underworld gods are raised spikes representing thorns of the tropical kapok tree (Ceiba pentandra).

The Maya believed that the kapok tree, which was also called the Maya "world tree" or the Yaxche, had roots in the aquatic underworld, so its depiction on this funerary urn may reflect how it is a conduit between realms, according to The Walters Art Museum. Jaguars also held important spiritual meaning to the Maya; they were thought to move fluidly between the three realms — sky, Earth and underworld. Therefore, the depiction of the deceased ruler wearing a jaguar costume to enter the underworld may have suggested that they could also mediate between the world of the living and the Maya gods.

This colorful and symbol-laden urn shows that death was not an ending for the Maya, according to The Walters Art Museum, and that the urn "serves as a graphic reminder of how the dissolution of the body could be a positive change, transforming a beloved ancestor into an honored spirit who would continue to guide the living for eternity."

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

Can you put together last week's Astonishing Artifact?

Researchers have developed a new type of interconnected architecture for quantum computing chips, and it could pave the way for machines capable of large-scale processing, including those with over a million qubits.

In a study published June 15 in the journal APL Quantum, scientists aimed to resolve a huge problem with the leading quantum processing units (QPUs): Qubits struggle to communicate and share quantum information with each other if they aren't immediate neighbors.

That's why the scientists pioneered Quantum Phononic Links (QPLs) — an approach for long-range coupling between qubits that leans on phonons — quasiparticles that carry vibration energy — to convey information. By contrast, conventional methods, like surface acoustic waves — high-frequency sound vibrations — demand complex designs and extra hardware.

"One of the key challenges in quantum computing is long-range qubit connectivity," Maksym Myronov, an associate professor of semiconductor materials and devices at the University of Warwick in the U.K. and first author of the study, said in a statement. "Our work introduces a new concept in which phonons act as a quantum bus, enabling distant qubits to exchange quantum information while remaining fully compatible with semiconductor technology."

In the study, the scientists said the most promising way to achieve a quantum computer that's capable of large-scale processing and takes advantage of QPLs would be a qubit modality known as "semiconductor hole spin qubits."

A "hole" here refers to the absence of an electron in a material, but it can act like a particle and have a spin state — a property used to encode quantum information — where the 1s and 0s of data would be represented by the direction of the particle's spin state.

To demonstrate this technology, they created a prototype QPU consisting of silicon with a thin germanium crystal layer, a specialized material they called compressively strained germanium on silicon (cs-GoS). Germanium is an especially useful material for quantum computing, the scientists said, as it has natural properties that reduce decoherence — the loss of quantum information due to external interference.

Hole spin qubits combine long quantum coherence times — how long they can retain quantum information — with the ability to communicate using electron impulses in control systems. But they struggle to form bonds and share quantum information with qubits they don't directly neighbor. In any large-scale system, for instance, enabling this "quantum coupling" between distant qubits is essential for quantum error correction techniques to work effectively across the breadth of a massive system, the scientists said.

Other proposed long-range communications approaches, such as "charge shunting" — redirecting capacitors to reduce sensitivity to charge noise, or surface acoustic waves — have fundamental limitations regarding scalability, both in terms of their size and in maintaining coherence. That's where QPLs come in.

QPLs are engineered phononic waveguides and cavities that both confine and guide acoustic modes within a compressively strained germanium "quantum well," where a quantum well is an ultrathin layer that acts as a guide.

In the study, the researchers focused on qubits using valence-band holes — the absence of electrons at absolute zero — hosted using cs-GoS. With QPLs, the scientists sent sound-like vibrations through the specialized material to carry quantum information between the distant qubits.

Spin states in this material are highly sensitive to lattice deformations, which enable precise control and the coupling of spin states with vibrational energy. Essentially, this allows the spin state to be distinguishable from its electron counterpart, enabling the phononic coupling strategies. The technique they adopted permitted direct coupling between the phonons and the hole spins.

By using a slow wave velocity (the speed of a quantum particle) and a short wavelength for acoustic excitations, the scientists used QPLs to link qubits separated by less than a micrometer (one-thousandth of a millimeter) and those up to 300 mm (11.8 inches) apart.

QPLs are not only promising for quantum computing, the scientists pointed out in the study. By utilizing phonons as the connections, this technique offers a versatile interface for hybrid quantum systems — conventional computers with quantum computing functionality. This could enable coherent interconnection of semiconductor spin qubits with other quantum platforms, such as cloud-based quantum computing.

The combination of phononic engineering and hole-spin physics makes cs-GoS a promising platform for next-generation quantum architectures, they added, since it could achieve both long-range coherent coupling and large-scale integration.

Can you match these ancient devices to their pictures? Find out with our computing quiz!

Physicists smashed gold nuclei together at nearly the speed of light and found an unexpected pattern in the particles these collisions sprayed out. If confirmed, that pattern could help reveal how the hot soup of quarks and gluons that filled the universe in the first few microseconds after the Big Bang cooled and condensed into the protons and neutrons that make up ordinary matter today.

In every collision, particles are flung out sideways; how hard they are flung, on average, varies slightly from one collision to the next. Physicists expected the size of these variations to change smoothly as they adjusted the collision energy. Instead, the variations dipped, shrinking and then growing again. This dip could be a sign of a long-sought "critical point," a special set of conditions at which nuclear matter changes the way it transforms from one form to another.

The signal, detected by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in New York, is strong enough that it is very unlikely to be a statistical accident. However, the researchers cautioned that the dip is a tantalizing hint, not proof of the long-sought transition. They published their findings Sept. 22 in the journal Physical Review Letters.

A rulebook for extreme matter

Protons and neutrons are made of smaller particles called quarks, which are held together by the "strong force" carried by particles called gluons. When heated or squeezed enough, protons and neutrons melt into a hot soup of free quarks and gluons known as a quark-gluon plasma. It's thought that this primordial soup of particles filled the universe in the first milliseconds after the Big Bang.

Physicists want to pin down how this soup-ification happened, by measuring the so-called equation of state of nuclear matter. "For water, it tells you how pressure, temperature and density are linked, and therefore when it freezes, boils or expands," study co-author Rutik Manikandhan, a postdoctoral physics scholar at The Ohio State University, told Live Science in an email. For nuclear matter, "it is the basic rulebook for matter under the most extreme conditions in nature, such as the cores of neutron stars," Manikandhan added.

The "critical point" is a key landmark in that rulebook "For water, it is the point where the boundary between liquid and steam disappears," Manikandhan said, and theorists have long suspected that nuclear matter has a similar point. At extremely high temperatures, matter melts smoothly and gradually into quark-gluon plasma, but at higher densities, the change may become abrupt.

The critical point would mark where one kind of transition turns into the other. Some recent calculations place this point within reach of RHIC's lower-energy collisions. "But all of this is still conjectured and there is nothing concrete yet, either from the experimentalists or theorists," Manikandhan said.

The work also matters for cosmology. "Because the matter we create in these collisions resembles the matter that filled the universe a few microseconds after the Big Bang, mapping how it behaves helps us understand how the universe evolved from a hot soup of quarks and gluons into the protons and neutrons that make up everything today," Manikandhan said.

A dip where a smooth trend was expected

To explore this territory, the researchers ran RHIC at a range of collision energies. The lower the energy, the more tightly the colliding matter was squeezed. For its lowest-energy runs, STAR used a "fixed-target" setup, in which a beam of gold nuclei strikes "a thin gold foil placed inside the detector," Manikandhan said, instead of a second, oncoming beam. This produces the densest matter RHIC can make.

Collision energies are measured in electron volts (the energy an electron gains when accelerated across 1 volt). That is a minuscule amount, so particle physicists usually work in billions of electron volts, or giga electron volts (GeV). One GeV is roughly the energy locked up in the mass of a single proton, according to Einstein's famous equation E = mc². The team analyzed roughly 1 billion collisions at energies between 3 and 7.7 GeV per pair of colliding protons or neutrons. That is the bottom of RHIC's range, which reaches 200 GeV.

In each collision, the team measured how hard charged particles were flung sideways out of the fireball ‪—‬ a quantity known as transverse momentum. The researchers then looked for correlations between the particles. A correlation measures whether two things tend to change together. Here, the team checked whether pairs of particles from the same collision tended to both be flung harder than average, or both more gently. That reveals something about the fireball as a whole. If a fireball is slightly hotter, or expands more forcefully, all of its particles get an extra sideways kick together.

"Those correlations reflect how much the temperature and the flow of the fireball fluctuate," Manikandhan said.

Close to a critical point, the matter's heat capacity — the amount of energy needed to raise its temperature — is expected to shoot up. That makes the fireball's temperature harder to budge, so the correlations should weaken. "If the matter approaches a critical point or a phase change, we would expect to see those correlations change in an unusual, non-smooth way as we vary the collision energy," Manikandhan said.

That is what the team saw in the most head-on collisions. "Instead of changing smoothly with energy, the correlations show a dip," Manikandhan said. The researchers compared the data with a smooth trend anchored by earlier STAR measurements at higher energies. The dip departs from that trend with a statistical significance of 5 sigma, the standard physicists usually demand before treating a signal as real. It means that if the true trend were smooth, random scatter in the data would produce such a pronounced dip only about once in 3.5 million tries.

"A smooth trend is what you'd expect from ordinary nuclear matter, so a dip suggests something more interesting is happening at those conditions," Manikandhan said.

By contrast, a widely used computer simulation of the collisions, which contains no critical point, reproduced the overall trend but not the dip. Off-center collisions showed only a faint hint of the same feature, which is too weak to count as evidence on its own.

Not the final word yet

"The result is suggestive, not proof of a critical point," Manikandhan said. Effects unrelated to a critical point can also shape these fluctuations, and how much of the dip they could explain remains unclear, the researchers noted.

Still, the dip "does point to a set of conditions where the behavior of nuclear matter changes, and it gives theorists a new, precise measurement to test their calculations against," Manikandhan said.

Next, the team plans to use the correlations to "extract the specific heat of the hot matter," Manikandhan said. They will then compare it with supercomputer simulations that calculate the behavior of quarks and gluons from first principles.

The researchers also plan to test the dip against more theoretical models and combine it with other measurements, such as fluctuations in the number of protons produced in the collisions. "Only when different measurements agree can we say confidently whether a critical point exists," Manikandhan said.

The debut images from a new Earth-observing satellite have just given us a view of the impossible: giant auroras rippling over the North Pole in broad daylight.

Earth's auroras are one of our planet's signature wonders — a sight worth advertising in interstellar travel guides, alongside our perfect total solar eclipses, bright shooting stars and majestic blobfish. They are the beautiful result of electrical storms in the atmosphere, appearing when charged solar particles skate along Earth's magnetic-field lines and collide with light-emitting molecules near the poles. (Auroras do exist on other planets, but they are usually not in bright visible colors like ours.)

To human eyes, auroras come out only at night and rarely stray from the poles. That's what makes these first observations from the joint European-Chinese Smile mission, which officially began science operations this week, so special.

Captured in ultraviolet light, the stunning images show a huge, serpent-like ring of charged particles coiling around the North Pole in July 2026. In the foreground, Earth appears ghostly and featureless, glowing like a half moon. The aurora writhes around our planet's sunlit side, covering about a third of it, while Earth's dark nightside bleeds into the background sky. Far behind, bright stars fall like raindrops as Smile shifts subtly in its orbit.

The view alone is worth smiling about, but the new images also promise exciting science to come. Taken just two weeks after scientists first turned Smile's Ultraviolet Aurora Imager on, the observations show that the satellite's instruments are working as they should and that the joint European Space Agency (ESA) and Chinese Academy of Sciences mission can officially begin.

Launched on May 19, Smile will spend the next three years watching Earth from a highly elliptical orbit that takes it about 75,000 miles (121,000 kilometers) over the North Pole — about a third of the way to the moon. From there, Smile can observe the North Pole for a record-breaking 45 hours at a time, offering an unprecedented view of solar activity there.

In addition to the Ultraviolet Aurora Imager, Smile carries three more science instruments to detect X-rays, magnetic fields and light ions over Earth.

This week, scientists also tested the spacecraft's soft X-ray imager by pointing it at the distant supernova remnant Cassiopeia A, located about 11,000 light-years from Earth (image above). Although the camera is working fine, the detector is still picking up a bit too much light when aimed at Earth, so it will require a bit more calibration from scientists on the ground.

In 2023, an African gray parrot named Jack went viral for mimicking the coughs and wheezes of her owner's father, who often struggled to breathe from severe chronic obstructive pulmonary disease.

But it wasn't just the imitation that made Jack famous; it was also that she seemed to relish the suffering of a man she purportedly hated. In the video, Jack's owner even claimed that she had a favorite cough.

The parrot appeared to be experiencing a complex emotion that in humans is known as schadenfreude, or pleasure at seeing another's pain. Literally translated from German as "harm joy," it's a feeling that might emerge when a rival coworker gets fired, or when a rude neighbor has their package stolen.

When a cat seems a little too happy watching a human stub their toe, or a horse seems to grin at a person stepping in poop, their owners might also interpret their behavior as schadenfreude.

But can any animals really experience such a complicated emotion? Or is this a classic case of anthropomorphization?

A complex emotion

Animals probably do not experience schadenfreude, according to researchers who study animal behavior and intelligence. However, the question hasn't received much attention in formal research. That's partly due to limitations of animal behavior methodology, but also because the question is bound up with how we define and communicate emotion in the first place.

"The study of complex emotions is incredibly difficult when you're talking about an animal that cannot communicate their emotions linguistically," Zachary Silver, an assistant professor of psychology who leads the canine intelligence lab at Occidental College in Los Angeles, told Live Science. "We don't have the ability to be as precise as we like to be in the scientific community."

Silver explained that researchers can look at behavior, neurological signals or hormonal activity to make an educated guess about what an animal might be feeling. A dog that has its ears back and tail tucked, for instance, is probably experiencing a negative emotion, while one wagging its tail is feeling a positive one.

But "aside from positive and negative, without words to describe the emotion, it becomes very difficult to disentangle," Silver said. The dog could be happy, but it could also just be interested in something new. "It's just so hard for us to say with any definitive nature that we really can know exactly what emotion is going on there," Silver said.

Animal behavior researchers try to avoid anthropomorphizing animals ‪(attributing human qualities to them) without evidence. When a cat or dog comforts a grieving human, for example, it could just be that the behavior was previously reinforced by rewarding the animal with treats or pets, rather than a genuine outpouring of sympathy. Similarly, Jack the parrot could have been mimicking coughs just for attention.

To truly experience a complicated emotion like schadenfreude, an animal needs to understand the emotional states of both itself and others — a concept called theory of mind.

"Dogs may have some ability to attribute mental states like emotions, thoughts, beliefs, intentions to other individuals, but this really only occurs in very select contexts and in really kind of a rudimentary way," Silver said. Because of this, "it's exceedingly unlikely that dogs would be able to experience schadenfreude in the way that we as humans do."

David Stahlman, an animal behavior researcher at the University of Mary Washington, agreed that such emotional capacity in animals is unlikely. He said that animals do not seem to have the ability to recognize their own emotional states, though he noted that not all animal behavior researchers agree.

"There's a difference between the affect, the emotional behavior, and then the recognition of the emotional behavior in oneself," Stahlman said. If nonhuman animals were to have this capability, he suspected it would probably be found in highly social great apes, like chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). Schadenfreude, in particular, would require animals to live in close social groups, since it requires knowledge of the individual experiencing the harm and whether it's deserved.

In hierarchical groups, it's possible that the suffering of one animal might benefit another and lead to something resembling happiness, Stahlman said, but he doubts this would ever qualify as true schadenfreude.

"The kind of Machiavellian stuff is a very human thing," he said.

Nevertheless, “there is a lot of data pointing in the direction that animals do have really deep capacities for emotional intelligence,” said Kaeli Swift, an animal behavior researcher at the University of Washington and author of the Corvid Research blog.

Swift noted that studies of some corvid species have found evidence of emotional recognition, fairness and "some of the strongest evidence across the animal world" for theory of mind. However, when it comes to studying an emotion as complex and subjective as schadenfreude, she said that researchers "haven’t quite crossed that threshold."

In the study of animal emotions, she said "we have barely started to scratch the surface."

About 1 in 8 cancer cases are caused by infections with viruses, bacteria or parasites, a new study finds, suggesting that one of the most effective ways to reduce cancer rates might be to prevent common infections.

In a new analysis published Sept. 28 in the journal The Lancet Oncology, researchers mapped the global impact of 12 cancer-causing pathogens. They estimate that infections drove about 2.3 million new cancer cases in 2024, or about 12% of all cancer cases diagnosed that year.

The study highlights that a large fraction of cancer cases could be avoided if these underlying infections were prevented, Dr. Prashant Mathur, director of India's National Centre for Disease Informatics and Research, who was not involved in the study, told Live Science in an email.

"When combined with other risk factors such as tobacco use, alcohol consumption, appropriate diet, physical activity, and environmental pollution, it is estimated that about 50 to 60 percent of all cancers in India are avoidable," he said. Past studies suggest that similar figures hold on a global scale.

In the new study, the researchers used the Global Cancer Observatory's GLOBOCAN database, which combines data from various cancer registries to estimate that about 20 million new cancer cases were diagnosed in 2024. The team combined that information with other published data examining the prevalence of different infections in people with specific cancers. This enabled them to estimate how many cases were attributable to each infection.

Their analysis focused on 12 pathogens tied to cancer, including human papillomavirus (HPV), hepatitis B and C, HIV and Epstein-Barr virus (EBV), the virus behind mononucleosis. The resulting breakdown revealed that just four pathogens accounted for roughly 92% of the cancer cases caused by infections.

A bacterium called Helicobacter pylori, which infects the gastrointestinal tract, accounted for 760,000 cases, primarily gastric cancers. The other three leading cancer triggers were viruses. HPV accounted for 750,000 cases, including cervical, penile, throat and mouth cancers. The liver-attacking hepatitis B virus was responsible for 360,000 cases and EBV drove 260,000 cases. (EBV is known to increase the risk of throat cancers, as well as certain lymphomas and stomach cancers.)

The scale of the burden contrasts with gaps in prevention. In 2024, just 31% of eligible adolescent girls worldwide received at least one dose of the HPV vaccine, well below the 90% target, the World Health Organization reports. The degree of protection provided by the vaccine is striking in countries that have achieved higher coverage.

"We have now achieved the critically important milestone of cervical cancer starting to disappear in countries that quickly achieved vaccination rates of over 80 percent," said Dr. Rebecca Perkins, an obstetrician-gynecologist at Tufts University School of Medicine who was not involved in the study. "Research from Australia, England, and Finland have shown zero cases of HPV-related cancers or deaths in young adults who received vaccination by age 13," Perkins told Live Science in an email.

But these successes are concentrated in wealthy nations. The Lancet study found that low- and middle-income countries bear 77% of the global infection-driven cancer burden. For example, about 81% of HPV-linked cancers occurred in these countries.

Perkins pointed out that shifting from the standard two-dose HPV vaccine series to a single-dose regimen using the same vaccines could make mass campaigns easier worldwide by lowering costs and eliminating the need to track patients for follow-ups. The single-dose approach has been backed by recent trials.

In the U.S., progress has been uneven across states with some boasting high vaccination rates and others lagging behind. One barrier is that some children's caregivers feel the shots are unnecessary or that their kids are too young to receive it. "The biggest misconception from families is that the HPV vaccine is not needed or that it can wait," Perkins noted. "The reality is that you can't vaccinate too early, only too late."

There is also a highly effective vaccine for hepatitis B, and health officials recommend giving children their first dose as soon as possible after birth. (The U.S. Centers for Disease Control and Prevention recently made the decision to stop recommending universal vaccination at birth, which experts say could raise the country's rates of hepatitis B infections and related cancers.)

While the challenge with HPV and hepatitis B is getting their vaccines into widespread use, there isn't an approved vaccine for EBV yet.

"The biggest hurdle has been the complexity of the virus," said Claire Shannon-Lowe, a tumor virologist at the University of Birmingham in the U.K. who was not involved in the study. "Unlike many other viruses that use just one or two virus proteins to enter cells, EBV uses multiple proteins ... and it hides inside cells for our entire lifetime."

Epstein-Barr infections are also incredibly common, with up to 95% of people infected by adulthood; most people infected with the virus don't develop a related cancer, but it's still a major contributor to the global cancer burden. The germ has also been tied to several autoimmune diseases, which may help spur the development of a vaccine, Shannon-Lowe suggested.

"With the increased impetus following EBV's association with multiple sclerosis and lupus, we may finally have a potential vaccine in sight that could not only prevent virus infection but could help treat EBV-associated cancers," she said.

For H. pylori, meanwhile, researchers are pursuing population-wide testing for and treatment of the infection to help prevent gastric cancer, while vaccine development remains an area in need of further investment.

The true scale of the infection-related cancer burden may be even larger than the study suggested. Some of the registries used in the new research cover only about 19% of the global population, and only 2% of Africa's population. More high-quality data is needed to fill in these gaps.

For Mathur, though, the bottom line is that cancer prevention makes economic sense.

"Studies have clearly demonstrated that the return on investment of prevention on cancers is much higher than on its treatment in the long run," he said. "Preventive aspects must be strengthened for long-term gains."

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

Mammals first appeared on Earth over 200 million years ago, scuttling around alongside the dinosaurs as little mouse-sized creatures. But after the asteroid hit 66 million years ago, it was their time to shine ‪—‬ and the Age of Mammals began.

But the path to understanding our own branch of the animal kingdom hasn't been straightforward. In this excerpt from "The Story of the Mammals in 25 Discoveries" (Columbia University Press, 2026), author Donald R. Prothero looks at a time when philosophers and early naturalists believed giants roamed the Earth and explores the idea that extinction was heresy.

Many cultures around the world have a mythology that includes legends about gigantic races of humans that lived on Earth in the dark mysterious past. They may have fought against the gods, or they may have been destroyed by floods. These stories were reinforced by the discovery of gigantic bones, much larger than those of any living human, all over the Mediterranean and Europe.

The Greek philosopher Empedocles (492-432 BCE) reported gigantic bones from Sicily, supposedly remnants of a race of giants. The Roman historian Pliny the Elder (23-79 CE) mentioned fossil ivory in the ground, and according to the Roman historian Suetonius (69- 122 CE), Emperor Augustus owned a collection of large bones that had been found on the island of Capri, near Pompeii. The skulls of elephants, with their huge central opening in front (for the trunk), were thought to be the skulls of the one-eyed cyclops.

In the Middle Ages, these huge bones were again attributed to gigantic humans or other monsters (Genesis 6:4) that were drowned in Noah's flood. Giant tusks from Siberia were thought to be the horns of the mythical unicorn or the tusks of dragons. In some places gigantic teeth or vertebrae of mammoths were revered as relicts of saints. Nearly every possibility was suggested except that they were the bones of extinct elephants.

In the early seventeenth century, some giant bones dug up in a sand pit near Langon in southeastern France were exhibited around France as the remains of the giant Teutons, Germanic tribes that once roamed Gaul and were defeated by the Romans in 101 BCE.

But in 1613 the famous anatomist Riolan attacked the prevailing interpretation, suggesting that they were the bones of an elephant. This generated a raging controversy between physicians and anatomists and the barber-surgeons who called them gigantic human bones. Others thought they were hoaxes or generated by mysterious "plastic forces" (vis plastica in Latin) that percolated through Earth. Still others attacked the anatomists for questioning the biblical account of giants on Earth. The controversies died down in 1618 without being resolved, and for the next two centuries most people continued to interpret new finds as gigantic humans.

The giant bones that kept turning up in the New World were also a source of much mystery and consternation. The Native American tribes usually attributed them to giant monsters fought by their ancestors and incorporated them into their folklore. When these bones were first seen by European settlers, they were thought to be the bones of gigantic humans that roamed the earth in biblical times. Others thought that the giant tasks so revered by the Native Americans were the works of Satan, placed there to tempt the believer.

In 1519, the Spanish explorer and conquistador Hernan Cortez received a bone of a "giant," a gift from the friendly Tlascalan tribe of Mexico during the conquest of the Aztecs. He sent it back to the King of Spain as proof that giants at once lived in the New World. In 1706, the Reverend Cotton Mather of the Massachusetts Bay Colony pronounced them to be "the remains of godless giants drowned in Noah's Flood." He sent some bones to the Royal Society in London to have them certified as evidence of this "wicked giant" because biblical scholars were calculating Adam's height at 123 ft. 9 in.

The Royal Society never pronounced an opinion on these bones, although by that time many members were becoming skeptical of the literal interpretations of Genesis. The stifling effect of religious dogma about giants and Noah's flood was complicated by another idea: the notion of Divine Providence. An omnipotent, benevolent God would never allow any of his creatures to become extinct. As the poet Alexander Pope wrote in An Essay on Man (1734), "who sees with equal eye, as God of all, a hero perish, or a sparrow fall."

The prevailing concept was that of a "great chain of being" that linked the animals to man to the angels to God. Breaking any link in that chain implied the destruction of the whole chain. In the same poem, Pope also wrote: "Where, one step broken, the great scale's destroy'd; From Nature's chain whatever link you strike, Ten or ten thousandth, breaks the chain alike."

By the late 1700s, however, it was becoming more and more apparent that many of the recently discovered fossils had no living counterparts. Remote corners of the world were being explored, and although many new and surprising beasts were discovered, clearly the gigantic beasts were not hiding in South America or Africa or the East Indies. Many strange fossils, such as the bones of hippopotami in Paris and London, were clearly related to tropical animals, but it was assumed that these bones had been washed from the tropics during the Great Flood.

The notion of extinction was still blasphemous. The New World soon provided unequivocal evidence that these large bones were not simply gigantic humans. In 1739, Charles le Moyne, the second Baron de Longueil, left Montreal with French and Indian troops to fight the Chickasaw Indians along the Ohio River. Somewhere along the Ohio he found the remains of what appeared to be three elephants. When the war ended in 1740, le Moyne collected the bones and shipped them to New Orleans and ultimately to Paris, where they came to the attention of French naturalists.

In the 1740s and 1750s, English settlers in the region sent more of these bones from Big Bone Lick, Kentucky, off to England and also to Benjamin Franklin in America. Most of the bones (especially the tusks) were clearly like those of elephants and mammoths, but the teeth were puzzling. They were clearly unlike any living elephant, yet they were part of an animal of elephantine size. (We now know that these were specimens of the American mastodon, Mammut americanum.) Franklin speculated that the teeth were reminiscent of a carnivorous animal, although he and others later decided it was a vegetarian.

In 1769, the famous British anatomist William Hunter took the carnivory suggestion seriously and suggested this was not a true elephant but a "pseudelephant" or "American incognitum" (Latin for "unknown") that had independently developed ivory tusks:

"This monster, with the agility and ferocity of a tiger . . . cruel as the bloody panther, swift as the descending eagle, terrible as the angel of night. . . . And if this animal was indeed carnivorous, which I believe cannot be doubted, though we may as philosophers regret it, as men we cannot but thank Heaven that its whole generation is probably extinct."

This very precocious suggestion was still not accepted by naturalists of the time. Nevertheless, remains of the "incognitum" and also of the Siberian mammoth (including frozen carcasses with hair and skin) were turning up again and again. Georges Louis Leclerc, the Comte de Buffon (1707-1788), concluded in his Théorie de la terre in 1749 that although most of the supposedly extinct animals were hiding somewhere in an unknown region, it was likely that the large terrestrial mammals such as the mammoth and "incognitum" had actually perished.

By 1778, Buffon was relating their disappearance to his ideas of violent cataclysms in Earth's early history. During this time the climate was warmer and polar regions had once been tropical, so "elephants" (meaning mammoths) could live in Siberia. This implied a nonbiblical Earth of much greater antiquity. Buffon suggested it was as much as 75,000 to 3,000,000 years old, rather than the 6,000 years demanded by most literalist biblical scholars.

Naturally, such revolutionary ideas were not popular with the theologians in the Sorbonne. Buffon was protected by the king, however, so he was not persecuted for his heresy, although his ideas were not widely accepted either. The fact of extinction was finally proved by one of the greatest scientists of all time, the Baron Georges Cuvier (1769-1832).

Jean Leopold Frederic Georges Cuvier was an impressive man. Tall of stature, he had a "massive" head crowned by a large mane of hair. One admirer wrote that his head "gave to his entire person an undeniable cachet of majesty and to his face an expression of profound meditation." After his death, scientists weighed his brain and found that it was a massive 1830 grams [4 pounds], more than 400 grams [14 ounces] above average, and 200 grams [7 ounces] heavier than any brain ever measured at that time.

More important, he was one of the most brilliant men of his time, with a command of many subjects, some of which he invented all by himself. Before Cuvier, natural history was a field that resembled stamp collecting, with many amateur naturalists compiling long lists and descriptions of new species without analyzing the similarities in their anatomy. Cuvier almost single-handedly revolutionized natural history by dissecting many different animals and discovering their underlying similarities and differences.

This became the foundation of comparative anatomy, a subject that has been fundamental to biology ever since. Naturalists and explorers sent him their fossil bones, and he was the first to correctly describe many types of extinct animals. Cuvier solved the mystery of the puzzling fossil teeth called the "Great Incognitum" and recognized them as the teeth of the elephant-like mastodons. He also correctly deciphered the huge marine lizards we now know as mosasaurs.

For this reason, he is also considered to be the founder of vertebrate paleontology. Cuvier is most famous for his "law of correlation of parts," wherein he discovered that certain types of anatomical features tend to be associated. If you are a flesh eater, you will have sharp teeth and claws; if you are a plant eater, you will have flat grinding teeth and hooves; and so on. Using this law, paleontologists have been able to reconstruct whole animals from just a few key bones because the other parts of the anatomy are so predictable.

Excerpted from The Story of the Mammals in 25 Discoveries: Amazing Fossils and the People Who Found Them by Donald R. Prothero. Copyright (c) 2026 Donald R. Prothero. Used by arrangement with the Publisher. All rights reserved.

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Could a psychedelic drug help the brain recover from mild injuries? New research suggests that psilocybin, the mind-bending ingredient in magic mushrooms, might protect the brain from the damage caused by minor head impacts.

Even mild head impacts that don't count as concussions can raise the risk of neurodegenerative disorders such as chronic traumatic encephalopathy (CTE), so finding an effective treatment for these blows could be useful for warding off debilitating conditions down the line.

The new research, published in the journal Communications Biology, included only lab rats, so there's more work to be done to translate the findings to humans. But the early results hint at a new application for psilocybin — a drug that's already been explored for a range of other conditions, including depression, PTSD and anorexia.

Live Science spoke with study co-author Argel Aguilar-Valles, an associate professor of neuroscience at Carleton University in Ontario, about the new study and how the research might eventually translate to treatments for repetitive head injuries.

Nicoletta Lanese: In this new study you focus on mild head trauma. Why does that minor level of injury still raise concern?

Argel Aguilar-Valles: This work was spearheaded by our collaborator, Dr. Craig Ferris at Northeastern University in Boston. The idea was to focus on the cumulative effect of those milder head hits, or injuries, that happen quite commonly; a lot of children and older adults can have repeated instances of these events of head trauma, and it doesn't necessarily lead to any immediate treatment or hospitalizations because they are considered fairly mild.

But over time, there's evidence that this can lead to cumulative and long-term effects that can affect the health outcomes of these individuals, particularly as we age. It's a risk factor for several forms of dementia. So the idea was to try to model this with a milder version of head injury [in lab rats].

So it's repeated — it's three hits — they're controlled, they're fairly mild. And they produce some alterations in the brain networks that are evident in using either MRI [which looks at the brain's structure] or functional MRI [which analyzes brain activity] analysis.

NL: So these are head impacts that don't come with the symptoms associated with concussions?

AAV: It's always difficult to compare [what a rat is experiencing] to what a human might experience, especially here. One good way to put it is that there's no loss of consciousness ‪—‬ so in those instances where the hits happen but you don't black out.

NL: Is there anything available now to manage and treat these mild impacts?

AAV: Well, as far as I'm aware, there's not really an intervention. I've experienced this secondhand with my children. Sometimes, they will come back from school and then they [the teachers] say, "OK, they had a hit on the head; there's a bump, but they didn't lose consciousness or anything."

Then sometimes, you go to the doctor concerned and typically you're told, "OK, just keep them under observation." If there's no vomiting, nausea, if there was no loss of consciousness, typically they just send you home and say keep an eye. Put some ice on it. Maybe don't overexert yourself in the next few days — and that's about it.

There is no intervention — for instance, if we do this [treatment], it's going to prevent you from developing dementia 50 years down the line. There's obviously nothing like that, particularly when you have repeated instances and the effects are cumulative.

NL: What made psilocybin seem like a potentially promising treatment for head trauma?

AAV: My group specifically has had an interest in testing the ability of molecules collectively known as psychoplastogens. We didn't coin the term, but it basically refers to all of these drugs that produce these brain-plasticity effects [changes in the brain's structure and activity]. These include serotonergic psychedelics [such as psilocybin and LSD, which affect serotonin receptors], and also things like ketamine or even MDMA.

We observe changes in cultured neurons in response to these drugs, in terms of dendritic complexity and increased synaptic spine density [changes in neurons' incoming and outgoing wires]. And in vivo [in live animals], you also observe functional reorganization of networks. All of these drugs have the ability to trigger these mechanisms. They do it through different pharmacological targets, but they all converge on some of these plasticity effects.

There are deficits in this plasticity in psychiatric illnesses, but also, obviously, in neurological disorders and even neurodegenerative disorders, where these plasticity mechanisms are completely nonfunctional.

So, we wanted to test the limit of the ability of these molecules to rescue, or to provide some therapeutic relief, in conditions where you have physical damage or neurodegenerative pathological mechanisms underlying the disorders. We observed — and not only us, but several other labs have also observed — that some of these molecules do seem to provide some level of therapeutic relief. [Editor's note: The current study looked only at physical trauma, but other labs have started to explore psilocybin for neurodegenerative disorders.]

It's still unclear if they're disease-modifying, in the sense they could provide lasting changes that can modify the course of the disorder. But so far, the evidence indicates that they can at least help to ameliorate some of the negative consequences of either neurodegeneration models or physical trauma, like in this case.

NL: Psychedelics have been more thoroughly studied for conditions like depression. In both depression and head trauma, could similar mechanisms explain the drug's potential benefits?

AAV: Some of the cellular effects might be similar. But the underlying condition can look quite different. Even if you think of two cases of depression, they can look very, very different. The drugs are going to be engaging similar mechanisms, but also the context in which these mechanisms are occurring will probably affect the outcome. What is remarkable about these drugs is that they seem to be working in both cases, so they're certainly tackling something that might be common in both situations.

We don't know the limits of these drugs yet. I'm not trying to imply that they don't have limits; what I'm trying to say is that our knowledge is incomplete. We don't know when they will work better than other potential treatment options.

I feel that will come when their clinical use is more widespread and we have a better idea of how they work in the heterogeneous populations that clinicians have in real life. In our animal models, conditions are very, very controlled and homogeneous, so they respond in a certain, similar way, whereas in the clinic, you observe huge disparity [in responses].

NL: Is there reason to think that psilocybin would be more promising than other psychoplastogens?

AAV: I think a lot of the focus on psilocybin has been because it's one of the psychedelics that's been more widely tested both in clinic and preclinical settings.

I'm not a clinician, but one of the reasons why psilocybin is favored over others is the length of the psychedelic trip. It's a few hours. If you go with something like LSD, it will last much longer. While the person is under the influence of the drug and undergoing the trip, there needs to be clinical supervision, so it becomes really challenging logistically to arrange sessions with psychedelics that last a long time.

That's also motivated preclinical research, like ours, to focus on this drug, as opposed to others that may have similar effects. From a potential translational perspective, it might be a safer bet to study this drug.

NL: In clinical trials of psychedelics, scientists often use a very small dose to try to avoid triggering strong hallucinogenic effects. Was that a goal with the rats?

AAV: No, they're probably experiencing something — this is a relatively high dose. A lot of people use 1 milligram of psilocybin per kilogram of body weight. In this case, they were using 3 milligram per kilogram, and it was based on previous imaging studies where they looked at the effects of this drug.

One measure we use is the "head twitch response," which is a behavioral measure that we commonly use in rodent work to test the hallucinogenic potential of a drug. This is a very rapid head movement that occurs in response to the serotonergic psychedelics. It's a behavioral response that correlates with hallucinogenic potential, and not perfectly.

For psilocybin, it's been very well characterized in the sense that it's mediated by the serotonin 5-HT2A receptor [in rodents], which is the same receptor that mediates hallucinations and the psychedelic trip in humans.

NL: What notable changes did you see in the rats in this study?

AAV: The measurements were done nearly three weeks after the injury. It's relatively short if you think of a human, but for a mouse, things happen much faster metabolically and physiologically. There was at least evidence of increased phosphorylation of tau [changes in a specific brain protein tied to Alzheimer's], and that was reversed by the treatment with psilocybin. That was certainly one surprising finding, and it's worth following up, I believe.

But also the hyperconnectivity — the brain's functional connectivity was really dramatically affected in the treated rodents with the head hits. They not only recovered but went to higher levels than the control-group animals.

We don't really know what the meaning of that is, but certainly it's quite remarkable how the networks became hyperconnected. And hopefully that means something positive for the animals. But it was certainly surprising, the level of recovery of that particular measure.

NL: And these effects were seen throughout the brain?

AAV: There were effects in a lot of brain regions — the thalamus, the hippocampus, the basal ganglia, and all different parts of the cortex, etc. One of the things that stands out from this study was the connectivity of dopaminergic nuclei [hubs of dopamine production in the middle of the brain]. Their connectivity is really fundamentally changed by the hits and then by the treatment with psilocybin.

These modulatory regions, the dopaminergic regions, are concentrated in one part of the brain, but they affect overall brain function because they have these widespread connections. So they're really crucial for a lot of functions, and we're seeing effects in these regions — that's really intriguing.

NL: Is it known whether the strength of the psychedelic trip has anything to do with the degree of benefit?

AAV: It is currently a hotly debated topic in the psychedelic field, whether the intensity of the psychedelic experience has anything to do with the beneficial effects or not. You can envision situations like psychological trauma, as opposed to physical trauma, where that trip might be part of the therapeutic mechanisms. It becomes evident in the debriefing sessions after psychedelic treatment, where it seems like in some cases, the psychedelic experience is fundamental.

But these are fairly correlative measures — if the two happen at the same time, it doesn't mean that they are linked together causally. So that's something that is being tested actively. One of the ways is the development of these non-hallucinogenic analogues that seemingly trigger similar plasticity mechanisms as their psychedelic counterparts do [without causing a trip].

I don't think we've had the first clinical trial with these drugs yet. Some of them may have undergone Phase I clinical trials just for safety, but I believe none of them have been tested in Phase II trials yet [in which their effectiveness is explored for specific conditions].

NL: Given this work is in rats, what are the next steps to translate this into a treatment for people?

AAV: Extending the observations, like other groups have done — looking at what happens if you do give this treatment months after the events. It's still unclear to me if, with this model we have, you will have effects months later.

We have some correlative measures that potentially BDNF expression [a gene for brain-derived neurotrophic factor, which helps neurons grow connections] is increased, and also the levels of its receptor, called TrkB. That is a possibility that needs to be further investigated, trying to find out whether these neurotrophic factors are crucial for the effects that we're seeing.

And obviously, the psychedelic trip is still a potential issue. But testing whether these non-hallucinogenic derivatives have the same lasting effects as their hallucinogenic counterparts do — that will be crucial and that can, in some cases, potentially facilitate the translation [into treatments]. Because not every person reacts the same way to these hallucinogenic compounds, and not everybody has the same risks.

NL: I assume the non-psychedelic options might be better for children, for instance?

AAV: We don't know what the consequences [of psychedelic use] are in a developing brain. There's not enough data. That will be obviously a big thing to sort out before recommending the use of these drugs, and maybe some of those non-hallucinogenic derivatives may hold the answer for that — for those cases where you really don't want to induce a full-on psychedelic experience.

There's also schizophrenia and a bunch of other psychiatric diagnoses with psychosis associated with them — from bipolar or psychosis-like events or episodes — where you might not want to apply a serotonergic psychedelic.

NL: Looking ahead to the next five to 10 years, what do you hope to see in the field?

AAV: There's a lot of enthusiasm in the field and a lot of push to try to characterize and understand better these drugs, from a basic perspective or a cellular level up to a brain wave level and then also the psychological effects. So there are a lot of different disciplines implicated in studying these drugs, and I think that's really exciting. That will hopefully lead to a wealth of knowledge about these drugs — not only their effects but also their limitations and their potential risks.

Hopefully we will have a balanced approach as scientists, to be able to really tease apart in which cases it [psychedelic treatment] will be really useful and in which cases the risks outweigh the benefits. That will be crucial to understand.

There's a lot of potential there, but we should proceed with caution.

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

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Among the many risks astronauts face during long-haul spaceflight, an extended stay in microgravity is one of the most consequential for long-term health, with effects on vision, bones, muscles and many other aspects of the body.

One solution might be artificial gravity —‬ some way to create forces similar to Earth's gravity on a spaceship, akin to the giant rotating ring from Stanley Kubrick's 1968 film "2001: A Space Odyssey."

But is that technology ever coming, or will it remain science fiction?

"There's really no reason it couldn't happen," Torin Clark, an associate professor of aerospace engineering at the University of Colorado Boulder, told Live Science. "From a technical perspective, this is something that could happen in the very near future."

In fact, artificial gravity has almost made its way to space before. The Centrifuge Accommodation Module was a planned 8.2-foot-wide (2.5 meters) centrifuge for the International Space Station (ISS), but the project was canceled in 2005 for budgetary reasons.

"[Artificial gravity] is one of those things ‪—‬ like all of a sudden, it's super popular, and then all of the scientists at NASA and everybody … have a lot of funding to understand how to actually implement this, and then it just dies," Ana Diaz Artiles, an associate professor of aerospace engineering at Texas A&M University, told Live Science. "And then it comes back, and dies, and comes back. I've been going through a couple of these cycles in the time that I've been doing this."

Besides budgetary concerns, there are questions about how such a solution would be implemented.

"Everybody agrees it's a good thing to do. The problem is that we don't know how to implement it," Diaz Artiles said. "How much gravity do you need? How big does [the device] have to be? How long do you need it to be? And how long do you have to use this? Should we use continuous gravity or a short-radius centrifuge, something where you go in and out?"

Researchers have three main approaches for creating artificial gravity. One is the classic sci-fi idea: a giant ring that rotates passengers' entire living quarters so they live and work under forces similar to Earth's gravity.

"You have a relatively long radius, which means you don't have to spin very fast to create gravity," Diaz Artiles said. "But this is massive. You can't get all the parts up there in the same spacecraft — you need multiple spacecraft and to assemble everything. So, of course, you can see what a big endeavor this is."

A short-radius centrifuge is a more feasible option. It's essentially a tube with a radius of 6 to 10 feet (1.8 to 3 m) that spins to simulate gravity. A passenger sits or stands inside, with their head closest to the center of rotation, so the spin generates the strongest pull down toward their feet.

Instead of allowing passengers to live in artificial gravity, this smaller device would be used in short daily sessions. "It's kind of like an exercise device," Diaz Artiles said. "In the ISS, you have a treadmill, you have this resistive exercise machine, so you go there for 30 minutes to do your exercise, and then you get out."

The final option is for spacecraft to create gravity via linear acceleration. This works in the same way that an accelerating car pushes passengers back into their seats, except the spacecraft would be oriented to push an astronaut's feet into the floor. To slow down, the spacecraft would turn around, firing its thrusters in the opposite direction to decelerate smoothly while maintaining a roughly similar gravity for its occupants.

"But then you need something like an engine that is able to accelerate all the time," Diaz Artiles said. "And propulsion-wise, I think we're not there yet."

Although a short-radius centrifuge is the most feasible approach in terms of both cost and engineering, it does have some drawbacks. For one, its fast spin can induce the Coriolis cross-coupled illusion ‪—‬ a sensation of tilting or tumbling that happens when you tilt your head off-axis while rotating.

This is the effect that causes motion sickness, Clark said.

However, Clark and his team have found that people can build a tolerance to the sensation with training, simply by being in a slowly spinning centrifuge and gradually increasing the speed when they no longer feel the sensation.

"If you very slowly, incrementally increase the spin rate … and do that not just over one session but over multiple sessions across multiple days, as far as we could tell, anyone can be made to incrementally acclimate to the rotating environment [of] up to 20 to 30 rotations per minute," Clark said.

Would artificial gravity prevent harmful effects on the body?

But researchers still don't know how fast the centrifuge would need to rotate, or how long someone needs to spend inside it, to benefit. Long periods in microgravity can lead to bone and muscle loss, loss of aerobic fitness, blood clots, and visual issues from fluid shifts in the eyes. The hope is that artificial gravity could prevent those effects, but exactly how much gravity is necessary remains an open question.

Studies of people on head-down tilt bed rest ‪—‬ the standard research method for simulating spaceflight deconditioning ‪—‬ have found that 30 minutes a day in a centrifuge did prevent some loss of muscle function.

"Thirty minutes a day … maybe is not enough," Clark said. "Maybe an hour or even two hours a day, and maybe at higher G levels, would be beneficial."

But these studies are expensive and time-consuming. "It's very difficult," Diaz Artiles said. "I think people are interested in this concept, but we just don't have a good answer."

In the end, it's not a technological challenge that's keeping artificial gravity from being used in space; it's knowing the best way to employ it and securing the budget for it.

"We know how to do this. As humans, we have done more difficult things," Diaz Artiles said. "We need the money, but we also need to better understand the need."

See how much you know about human exploration into space with our spaceflight quiz!

Cape Cod is known for its lobsters and its growing great white shark population, but now the holiday hotspot has another extraordinary animal to showcase: a rare two-headed diamondback terrapin that is surviving against the odds.

The baby turtle, which weighed just 0.18 ounces (5.2 grams), was brought to the Cape Wildlife Center in Barnstable, Massachusetts, on Sept. 17, according to a Facebook post from the wildlife center. It was originally found by representatives of the Mass Audubon Wellfleet Bay Wildlife Sanctuary at a protected nesting site in the town of Wellfleet.

The turtle's condition, known as bicephaly, is a rare developmental disorder that's typically caused by the incomplete splitting of a single embryo during the formation of identical twins. It results in conjoined twins that share one body but have two fully formed, independent heads.

Zak Mertz, CEO of New England Wildlife Centers, which includes the Cape Wildlife Center, said the recently discovered diamondback terrapin (Malaclemys terrapin) is an uncommon example of bicephaly in turtles. Both genetics and epigenetics ‪—‬ the study of how genes and environment can interact ‪—‬ are thought to play a role in the condition's development.

"Our understanding based on the available research is that bicephaly is caused by both genetic and epigenetic factors," Mertz told Live Science in an email.

"It may have to do with the relatively long lifespan of the turtles, their preference for returning to the same nesting sites, and a limited gene pool due to their conservation status," he said."It may also be influenced by environmental factors, such as the temperature, humidity during incubation, physical characteristics of the nesting sites, or potentially even things the parents are exposed to in the environment."

Having two heads is rare but not unprecedented. According to the center, this is the third bicephalic terrapin found in the area in the past five years, providing another opportunity to learn more about the animals. Other wild animals with bicephaly have been found in recent years, including a two-headed porpoise found off the coast of the Netherlands and a two-headed dolphin that was found on a Turkish beach.

A 2021 study found that rare two-headed and partially duplicated sea turtle embryos and hatchlings showed significant craniofacial and spinal abnormalities and were generally smaller than typical hatchlings. The research found bicephalic turtles faced survival challenges because their abnormal anatomy could impair coordinated movement, feeding, and other functions essential for survival, highlighting the importance of monitoring such deformities as potential indicators of population and environmental health.

Diamondback terrapins are found in brackish marshlands along the Atlantic and Gulf coasts of the United States. Brackish waters have more salt than fresh water but less salt than seawater, and often occur where the freshwater of a lake or river meets the salty sea. These terrapins are classified as threatened by the Massachusetts Endangered Species Act, and their broader conservation status at the federal level is currently under review.

Veterinarians are monitoring the rare terrapin's health closely. "It is fascinating and an area that certainly merits more study," Mertz said. "We are excited to care for these two and learn as much as we can to inform future study in the process."

This year's exceptionally strong El Niño has brought a rare gift to Chile's Atacama Desert: rain. In one of the driest places on Earth, that rare moisture has awakened millions of seeds and bulbs that can remain dormant underground for years, transforming the landscape into a spectacular carpet of color.

Known locally as "desierto florido," or "flowering desert," the phenomenon is one of nature's most remarkable transformations. Patches of purple, pink, white, red and yellow now spread across hillsides and plains that for much of the year appear almost completely lifeless.

"It is a unique phenomenon; there are more than 200 plant species," Jorge Carabantes, head of the Protected Areas Department at the National Forest Corp. (CONAF) in Chile, told The Associated Press. "This is a flowering event that is obviously extraordinary and unusual, very different from other blooms that occur elsewhere on the globe."

Typically, the Atacama gets just 0.6 inches (15 mm) of rain a year. But thanks to the super El Niño, record levels of rain fell between July and August in several Chilean regions, including levels not seen since the 1950s, with some areas receiving more than 7 inches (190 millimeters), Carabantes told the AP.

While this unprecedented precipitation has caused flooding in some areas of Chile, it's created a 6,560-square-mile (17,000 square kilometers) swath of flowering blooms across the Atacama Desert. This is the most extensive desert bloom since 1997, CONAF representatives told the AP.

For photographers and tourists, the landscape is breathtaking, with bright colors contrasted against the dark Atacama mountains and Chile's cloudless skies. But the bloom is fleeting; by the end of the Southern Hemisphere's spring, many of the flowers will disappear, leaving behind seeds and bulbs waiting for the next extraordinary rains.

Here are five photos from Getty Images photographer Javier Torres that showcase the beauty of this rare event.

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The first animals may have appeared on Earth hundreds of millions years earlier than their fossils suggest, a new modeling study suggests.

Previously, the earliest fossil evidence of animals dated to around 574 million years ago, during the Ediacaran period (635 million to 538 million years ago). In the new paper, a research team argues that we can't just rely on the spotty fossil record, and suggests that animals first appeared up to 200 million years earlier than the oldest known animal fossils.

In the study, published Friday (Oct. 2) in the journal Science Advances, the researchers argue that the absence of animal fossils in some exceptionally well-preserved ancient rocks doesn't mean the animals were absent from history. Instead, they suggest that the fossil record may be missing a key chapter of animal evolution, potentially pushing the origins of animals back to between 800 million and 700 million years ago.

This would place the emergence of animals deep within the Neoproterozoic era (1 billion to 539 million years ago), possibly before or during some of Earth's most extreme ice ages.

Even though scientists haven't found undisputed animal fossils from the Neoproterozoic, that doesn't mean animals didn't live at that time. Fossils can be absent from rocks for several reasons, including because scientists are looking in the wrong places or the conditions were unsuitable for creating fossils, making it difficult to determine the earliest evolved animals.

"Until that evidence becomes available, the precise birth date of the animal kingdom remains uncertain," study co-author Ross Anderson, an associate professor of natural history at the University of Oxford, said in a statement.

Where are the animals?

Until now, most researchers relied on the well-preserved rocks from the Ediacaran period, including the roughly 590 million-year-old Weng'an Biota in China, to investigate the timing of animal evolution. Because rock deposits there contain uniquely preserved microscopic organisms but no definitive animal fossils, experts have sometimes treated them as a kind of upper limit for when animals could have evolved.

"So the game is basically how much does it predate our first fossil discovery by and what happened in that evolutionary black box between when they actually originated versus when we get our first fossil window," Karma Nanglu, an assistant professor of evolutionary paleobiology at the University of California, Riverside who wasn't involved with the study, told Live Science.

But the researchers wondered whether other fossil sites from known animal periods actually had evidence of animal fossils.

To find out, Anderson and his colleagues studied more than 140 samples from the Kheseen Biota in Mongolia, which is more than 40 million years younger than the 590 million-year-old Weng'an Biota deposit. Given that it's a younger deposit, the researchers hypothesized that there should be evidence of animal life left in the rock. Using electron scanning microscopy, the researchers saw microscopic fossils preserved in extraordinary detail, including tiny, spherical organisms and embryo-like structures containing internal cells.

Yet, despite the quality of preservation, the researchers couldn't identify any of the microfossils as animals. That's important, because by the time the Kheseen Biota was deposited, animals were present elsewhere on Earth.

"The Kheseen Biota breaks the argument that the exceptional microfossils of Weng'an mean we would have seen animal fossils in the assemblage had they existed at the time," Anderson said. "The Kheseen microfossils are just as well-preserved, yet animals continue to be absent — despite the fact we know at that point they existed."

Using molecular clocks

Given the absence of fossil evidence, Anderson and his collaborators turned to another common method used to date ancient life: molecular clocks. Molecular clocks estimate when evolutionary lineages diverged by comparing genetic differences among living organisms and combining those differences with rates of genetic change. For example, if two bird species have five DNA changes and one DNA change takes about 1 million years to accumulate, scientists could estimate that the two species diverged around 5 million years ago.

"Molecular clocks are useful when we don't have a particularly good fossil record for a group of interest or a time period of interest," Nanglu said.

When the analysis was constrained by the younger Weng'an deposit, the estimated origin of animals was comparatively recent. When they used older geological constraints — specifically rock formations in Norway, Australia and Arizona deposited between around 850 million and 730 million years ago that have been used in the past for trying to find animals' early ancestors, the timeline changed. By comparing modern animal DNA to reference dates from the fossil record along with evolutionary rates of change — their estimate shifted back by roughly 200 million years, to between about 800 million and 700 million years ago.

"Pre-Ediacaran animal body fossils still elude us, and this analysis does not prove that animals existed 800 million years ago," study first author Orin Lole Durbin, a doctoral student of paleobiology at Virginia Tech who was a University of Oxford undergraduate at the time of the study, said in the statement. "Meanwhile, our molecular-clock analyses show how much further back their evolutionary history could extend."

Could animals have lived before "Snowball Earth"?

There are other clues that animals may have a longer history.

Chemical fossils, or biomarkers, have been interpreted as evidence consistent with sponges living at least 650 million years ago, tens of millions of years prior to the oldest known animal fossils.

If animals did originate 800 million years ago, their emergence would also intersect with the Cryogenian period, which began around 720 million years ago as part of the Neoproterozoic era. During this interval, Earth experienced enormous glaciations often referred to as "Snowball Earth."

Although there is no definitive answer to whether animals survived this uncertain time, the researchers plan to search additional Neoproterozoic rocks with different environments and preservation conditions to find more evidence for their analysis.

"Fossils themselves are by definition kind of hidden from general sight," Nanglu said."Beyond that there's an even more hidden world, and that has a lot of potential to tell us about animal origins."

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