Tough times can fuel innovation, and battle-hardened Ukraine has demonstrated that fact of life more than most places in recent years. Since Russia’s invasion in February 2022, the country has utilized drones and robotics in ways not before seen in large-scale warfare. More recently, Ukraine has introduced a variety of remotely controlled ground vehicles tasked with entering contested territory and resupplying areas or even evacuating wounded troops. But while those wheeled robots help keep soldiers off the front lines, they are also vulnerable. Their air-filled tires are particularly vulnerable, since they can be shot at or break when rolling over barbed wire, shrapnel or even rugged debris. To solve that issue, engineers from a pair of Ukrainian companies developed a new type of 3D-printable tire that doesn’t require any air at all. And it’s already being deployed on front lines. 

The airless wheel is the result of a collaboration between two Print&Live UA, and iSCALE 3D. Their design is proposed to be built for Uncrewed Ground Vehicles (UGV) that come in various shapes and sizes depending on their task. Instead of a rubber casing filled with pressurized air, these new wheels are 3D printed around a lightweight internal lattice made from durable elastomers and composite polymers. The lattice flexes and springs back over rough terrain, essentially doing the cushioning work that air pressure does in conventional tires, but  without the risk of a  sudden debilitating puncture. 

The tires also feature a rounded tread and enclosed sidewalls which are meant to keep mud, stones and ice from packing in. According to Print&Live UA and iSCALE 3D, the result is  a wheel set far lighter than Western airless alternatives and that keeps working even after taking some damage. Fewer blown out tires, they say, could mean more lives saved. 

“The most important mission of a UGV is not spectacular—it is bringing a wounded person back, or water, medicine and supplies forward,” the companies write on their websites. “Every immobilized vehicle puts people at risk. That is the real purpose of this development.”

“One puncture and the mission ends where the machine stops,” they add. 

No tire factory? No problem 

In addition to the airless design, the 3D printing process makes the new wheels more adaptable. Each set can be tinkered with and adjusted to best suit the type of vehicle they will be equipped on, as well as for the specific mission type they might engage in. Stiffness, shock absorption, and overall geometry can all be tweaked on a computer. The process requires large, industrial-scale printers most hobbyists won’t have in their garage, but it’s still a much smaller, nimbler approach than an entire factory built to roll out one specific product.

“Because the geometry is digital, stiffness and damping are programmed for each UGV type and payload, and a design upgrade is nothing more than a new file,” the companies write. 

The engineers also designed these wheels with the chaos of a battlefield in mind. Each two-piece rim set lets soldiers swap out a damaged tire without the tire-changing machines or presses a conventional repair would need. That flexibility means soldiers can repair or swap tires with simple hand tools in battlefield areas where full workshops aren’t available.

A new R&D hub for defense tech 

Airless UGV wheels are just the latest in a growing list of creative fixes forced by the Russia-Ukraine war. The constant need for better drones and robots has turbocharged the country’s tech sector, which has grown from a handful of defense companies before the invasion to hundreds today. Most of the companies building out the new hardware are Ukrainian, but the war has also attracted a number of American defense startups that have set up shop there, drawn in by the change to their designs in the real world. The country’s capital city  has attracted so much tech sector interest that some have even ascribed it the moniker: “Mil-Tech Valley.”

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Artificial intelligence is undeniably good at playing games, regardless of its larger societal and environmental impact. In 1997, IBM’s supercomputer Deep Blue famously beat chess grandmaster Garry Kasparov, and nearly two decades later, Google’s AlphaGo managed to defeat a human champion at the much more complex game Go. Since then, another AI seems to beat humans at incredibly complex video games like StarCraft or Dota 2 every few months. Impressive as these feats are, AI has mostly outperformed humans by making us play on its home turf, as in, simulated and structured environments. But now, a team of engineers at the Micro Air Vehicle Lab at the Delft University of Technology in the Netherlands has built a lightweight smart drone that’s fundamentally altering that dynamic.

The team entered its AI-powered quadcopter in a high-profile drone race in Abu Dhabi that pitted AI-piloted drones against human-piloted ones. The niche sport, known as first-person-view (FPV) drone racing, has pilots steer remote-controlled drones through a series of small gates at blistering speeds of 60 to 100 miles per hour. They control the drone by using goggles that give a direct feed into a camera attached to the drone’s front. From a human’s perspective, it’s as if they’re flying through the sky. 

The team didn’t just fish the race. They took first place, besting several human FPV champions along the way. It marked the first time an AI-controlled drone beat a human pilot in an international racing competition. Another team from the University of Zurich built an AI-controlled drone that won a race against humans three years earlier, but only in a controlled lab setting. This more recent example showed that a simply trained machine, with minimal onboard sensors and hardware, could be inserted onto a non-controlled test track meant for human operators and still come out on top. 

The team won this race in November 2025 but new details about the science behind this achievement are published today in the journal Science Robotics. 

“Instead of giving the robot increasingly powerful sensors and computers, we wanted to find out how much intelligence we could extract from very limited resources,” Delft University aerospace engineer and study co-author Christophe De Wagter said in a statement. “Drone racing provided an extreme environment in which to test these ideas outside the laboratory. It pushed us to develop AI that was not only fast but also robust, and able to adapt when external reference measurements were unavailable.”

Drone racing: a sport built on human-machine connectivity 

FPV drone racing isn’t for the faint of heart—or, more accurately, for those with a weak stomach.  Footage of drones flipping and somersaulting at extreme speeds can make even spectators feel sick. Pilots fly using a pair of joysticks that control the drone’s throttle, roll, pitch, and yaw. That human-and-machine team has to fly through several small race gates that make up a lap. The drone finishing with the fastest lap times wins. It’s an extreme sport where even a microsecond of a mistake can lead to a violent crash. 

Though it’s not quite as popular as it was at its peak in the late 2010s, the sport still draws a considerable online audience. That’s pretty impressive, for a sport that only became possible thanks to simultaneous advances in several technologies. Namely lightweight batteries, miniaturized cameras, and the goggles and wireless video links that let pilots see what their drones see all had to come together for this extreme form of racing.

The fact that drone racing requires interacting with machines already equipped with sensors makes it a particularly interesting test bed for robotics and AI researchers. In 2022, the University of Zurich outfitted a drone with an AI model appropriately called Swift. That AI system collected real-time data pulled from the drone camera to “see” what it was seeing and to locate gates and avoid obstacles. An onboard neural network then parsed through all that in real time, making split-second decisions on the best routes to fly. Swift beat champion human pilots, a major feat at the time, but it did so on an indoor track measuring roughly 82-by-82-feet that the team had designed and trained the system for. When a condition even as subtle as the lighting changed, Swift’s performance suffered as a result.

Inspired by those results, the Delft team set out to build an AI racing drone that could better adapt to its environment. Like Swift, their machine called MonoRace uses a powerful AI model that interprets a video stream captured by the drone’s camera in real time. MonoRace also draws on an onboard inertial measurement unit (IMU), a sensor that tracks the drone’s acceleration and rotation. This IMU pulls data from onboard sensors as well as the camera, and helps the AI system better understand where the drone is position-wise on the track. 

That understanding of place makes it more equipped to fly without crashing even in less familiar environments. It also improves the drone’s perception over a solely camera-based approach, which can struggle when camera data is less than stellar. Remember, all of this is happening very, very fast. 

“Flying at very high speed with only one camera is challenging because the images are blurry, deformed, and the AI system has very little time to precisely determine where the drone is,” Delft University robotics researcher and study co-author Stavrow Bahnam said in a statement.  “We developed a robust way of combining what the camera sees with the drone’s own motion information, allowing it to navigate the track at high speed without GPS.”

What sets MonoRace apart from complex AI systems running on larger vehicles or humanoid robots is how stripped down it is. The entire system has to run on a tiny computer on the drone, light enough not to slow the drone down and efficient enough not to introduce lag. And yet, it’s still quite powerful, with the AI issuing an estimated 500 commands every second. Rather than train the model on one specific track, they trained it to learn how to adapt using a reinforcement learning approach. After many attempts of trial and error in a simulated environment, MonoRace figured out the best ways to quickly solve navigation problems and then apply that in the real world. 

“Instead of first planning a desired flight path and conventional commands, our neural network learns to directly control the motors,” study co-author and Delft University Aerospace Engineering PhD candidate Robin Ferede added in a statement. 

Putting MonoRace to the test

The team put MonoRace to the real test last November at the Abu Dhabi Autonomous Racing League, a major competition where some of the best human pilots battle to out. During its flights, MonoRace topped speeds of roughly 62 miles per hour as it looped, dove, and zipped through gates. It managed to beat out every other AI racing team in the competition, and also boasted a better time than three former human world champion pilots.  

According to the team, these results make MonoRace the first AI-piloted drone to beat human pilots in an international racing competition, and  could have an impact on  drone racing and  physical AI more broadly.  With self-driving vehicles and even some humanoid robots entering larger-scale production, there’s an increasingly high demand to build AI systems that better grasp how to move about the physical world without barreling into everything around it. A drone that can do that while performing acrobatics at more than 60 miles per hour suggests that engineers are, at minimum, heading in the right direction.  

So far, that hasn’t resulted in larger robots suddenly superseding humans at sports. The fastest robot sprinters, though admittedly quick in short bursts, also tend to crash into walls and burst into flames. 

The post An AI-racing drone beat the best humans and set a world record appeared first on Popular Science.

In exactly a month, on November 13, 2026, the world will end. Fittingly, our impending apocalypse falls on Friday the 13th. 

At least, that was the prediction made by University of Illinois physicist Heinz von Foerster in a highly cited Science paper published in 1960. Though talks of supposed doomsday have renewed in recent months thanks to hyperbolic anxieties over runaway, sentient artificial intelligence, von Foerster had a much different calamity in mind. 

For more than a century, the prevailing fear, dating back to English economist Thomas Malthus who lived between 1766 to 1834, was of a booming population outrunning its food supply. Famine would ensue. But Von Foerster broke from that view. He assumed (correctly, as it turns out) that human ingenuity would keep the world mostly fed. The problem, he argued, was that the population would keep accelerating, toward “infinity.” 

In a now infamous quote, von Foerster predicted, “Our great—great—grandchildren will not starve to death,” von Foerster and his co-authors wrote. “They will be squeezed to death.” Homo sapiens’ last gasping breath, they predicted, would peter out in the fall of 2026. 

It’s pretty clear that von Foerster’s estimate was dead wrong. Not only is the global population (around 8.3 billion people) not expanding near the rate it was when he was writing, but there are actually concerns it’s moving in the opposite direction. In dozens of countries around the world, from South Korea and Japan to much of Western Europe, the concern among demographers has shifted from worries about overpopulation to declining birth rates. 

In the United States, President Donald Trump has jumped on the issue, calling himself the “fertilization president” offering tax incentives for new families and even exploring medals for women who give birth to six or more children. Joseph Stalin previously championed that last idea. 

So how was a prediction so wrong and still so influential? Human population experts speaking with Popular Science say von Foerster and his contemporaries based their prediction on real trends from the past while utterly failing to see the world changing right before their eyes. Though they may have accurately measured growth rates up to that point, that only tells part of the story. 

“He got the picture right just as that picture ceased to be right,” Rockefeller University and Columbia University professor and mathematical biologist Joel Cohen tells Popular Science. Cohen has studied human population changes for years and published the influential 1995 book How Many People Can the Earth Support?

“Von Foerster didn’t know at the time, and in fact, nobody knew” that the all-time population growth had already happened, Cohen adds. “The all-time peak happened in the early 1960s.”

Why did experts think the world would end on Friday the 13th?

Von Foerster and his colleagues published their “Doomsday” paper on November 4, 1960. The dramatic pronouncement hinges on an equation that projects the human population into the future based on past trends. 

The team gathered 24 estimates of world population dating back 2,000 years. The key assumption underpinning their logic was that humans differ from other animals because of our unique ability to cooperate and innovate. 

Fruit flies in a jar eventually level off as crowding and competition take their toll. Humans, on the other hand, the authors argue, work the other way. The more of us there are, the better we get at cooperating. And the better we get at cooperation, the faster our population grows. 

Follow that curve forward, and the population doesn’t just grow; it rockets toward infinity, hitting the so-called mathematical wall on November 13, 2026, give or take five years. 

Von Foerster wasn’t alone in sounding the alarm either. Eight years later, biologist Paul R. Ehrlich would publish The Population Bomb, arguably the most influential single text fueling overpopulation fears. 

“Both of those guys were right looking backward, but wrong looking forward,” Cohen says. 

At a glance, thinking the future will resemble the past seems pretty reasonable. The human population grew steadily but slowly over much of our roughly 300,000 years of humanity. But that changed radically with the onset of globalization, colonization, and the Industrial Revolution. 

How fast is the human population growing?

As Darrell Bricker and John Ibbitson note in their 2020 book Empty Planet: The Shock of Global Population Decline, human population passed the one billion mark somewhere around 1800. That doubled to two billion by 1927. Then doubled again just less than 50 years later in 1974. It would then only take another 13 years to cross the five billion mark. And in 2022, we surpassed eight billion.

That remarkable explosion had many causes, Cohen says, but among the most important was the spread of cheap, calorie-dense crops like potatoes and corn from the Americas. 

Crucially, though, humans weren’t necessarily having way more kids. They were just far better at keeping them alive. 

Human population booms weren’t because people were having more kids

“Humanity got better at keeping the people who were born alive through simple, but important innovations like the germ theory of disease, sanitation, nutrition,” University of Texas Associate professor and economic demographer Dean Spears tells Popular Science. 

Demographers like Spears study human populations and how they change over time. He published a book on the topic titled After the Spike, earlier this year. Advances in nutrition and medicine “caused early life mortality rates to fall, so more of the humans who were born survived and that caused the population to grow.” 

Factoring in longer life expectancy and reductions in child mortality around the world blows a huge hole in Von Foerster’s calculations. Death rates can only fall so far, and once most children survive, families tend to have fewer of them. 

The population boom was a one time explosion, not an ever-accelerating loop. 

Overpopulation fears are actually based on a misunderstanding

Von Foerster’s assumption of endlessly accelerating growth, Spears says, was “based on a misunderstanding of where population growth comes from.” 

Experts specializing in human population studies at the time actually knew that was the case, Spears notes. 

Neither von Foerster’s nor Ehrlich (who wrote The Population Bomb) were human population experts. Von Foerster’s background was in physics and philosophy. Ehrlich was a biologist. But they were both great at getting attention. 

Indeed, academics at the time reportedly sent flustered letters to the editor at Science, calling the prediction “ridiculous” and “manifestly absurd.”

“There was never, even at that time, any reason to think that it would keep growing fast like that.” Spears says. “Paul Ehrlich was a biologist who studied butterflies, not human demography.” 

Why people are worried about declining birth rates now

In the later 20th century, population growth actually started declining quite rapidly thanks to a convergence of a variety of factors. 

The “Green Revolution” in farming meant that more food could be grown on the same plot of land, which extinguished fears of humanity suddenly starving itself. The first birth control pill, approved by the Federal Drug Administration (FDA) in the U.S. in 1957, also gave women more autonomy to decide when and how many children to have. 

These trends, along with global population shifts away from rural areas and towards more urban areas, would eventually shift concerns away from overpopulation and towards declining birth rates. 

Although demographers and policy experts debate how much people should worry about declining birth rates, it is generally agreed that an older population that significantly outnumbers younger people can lead to long-term strains on the country’s economy and social services. 

With fewer workers needed in the field, more and more people moved to cities. Historically, families living on farms or agricultural communities tend to have more children than those in urban areas because those children could work the land and, in a purely economic sense, provide more labor and, hopefully, make the family more money. In more urban areas, another child meant another mouth to feed rather than an extra pair of hands. 

In the later part of the 20th century, women in many parts of the world gained far more autonomy through education, work, and access to contraception, which demographers agree is among the biggest drivers of demographic change over the past half century. 

Some governments went further. China’s one-child policy (introduced in 1979) and India’s forced sterilization campaigns (between 1975-1977) were heavy-handed responses fuelled by overpopulation panic. What makes those coercive policies all the more tragic, Spears notes, is that birth rates likely would have fallen without them.

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“What we’re seeing now, a world of low and falling birth rates, is actually nothing new, but just the latest moment in a decades-long or longer trajectory of falling global birth rates on average happening essentially everywhere,” Sears says. 

“I would say that the coercive [state-sanctioned] school [of thought] was counterproductive,” Cohen adds. He went on to say he believes similar government-led initiatives encouraging  families to have more children today, like the Trump administration’s proposed baby medal, are “counterproductive.” Real, meaningful generational changes in population, Cohen notes, are more often the product of society-level macro trends beyond the scope of any one politician or party.

Today, about a month shy of von Foerster’s doomsday, around 55 percent of the world’s countries, home to more than two-thirds of its people, have fertility rates below replacement level. That’s the rate (about 2.1 children per woman) demographers use to denote where a population replaces itself from one generation to the next. 

In other words, not only is the human population not hurtling towards infinity, but in much of the world, it’s actually on track to eventually shrink. Experts largely agree birth rates are falling. Whether that’s a problem to be solved is less clear-cut. 

At the family level, having fewer children can mean more money, resources, and personal attention invested in each one. It can also mean more independence, opportunity, and choice for those who decided parenthood just isn’t for them. 

Stabilizing birth rates isn’t a fix all

At the broader economic or societal level, though, Spears argues there are good reasons to want birth rates to stabilize rather than keep falling. Pay-as-you-go social programs like Social Security depend on young workers to fund older people’s retirements. Fewer people also means fewer shared resources and services for everyone else.

“If you want to go out and eat lunch at a taco truck, but you’re the only person nearby who wants it, then the taco truck’s not going to be there,” Spears says. “And if you’re a school child wanting to go to school, there might not be enough other children for there to be a classroom nearby that’s suitable for you.”

Those are legitimate concerns, though Cohen warns that focusing too much on abstract numbers and trends can blur a more immediate issue directly in front of us. Globally, children are still regularly going underfed, so much so that the World Health Organization estimates around 22 percent of children under the age of five experience stunted growth from malnutrition.

“We are doing so poorly by the children we have that I can’t understand why the emphasis is on making more children,” Cohen says. “We’re talking about having more children when we don’t take care of the children we have. What the heck is that?”

But even for those who do worry about falling birth rates, Spears cautions against politicians promising quick fixes. This isn’t a short-term emergency, he says, but a “generational challenge.” One thing is clear though: Neither Spears nor Cohen are losing sleep over von Foerster’s November 13 death date. 

“I’m sure not acting as if I’m too concerned about it,” Cohen says. “I’m still paying my bills. I’m still paying my taxes.”

In Ask Us Anything, Popular Science answers your most outlandish, mind-burning questions, from the everyday things you’ve always wondered to the bizarre things you never thought to ask. Have something you’ve always wanted to know? Ask us.

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As residents on the northern Gulf Coast brace for quickly strengthening Hurricane Isaias (a Category 3 storm as of Friday afternoon), many are likely eyeing their roofs and walls with nervous anticipation. The Congressional Budget Office estimates hurricane force winds and storm-related flooding collectively cost households in the United States some $34 billion every year. And while rounded corners, sloped walls and reinforced construction can help mitigate some wind damage, these additions are often expensive or impractical for developers looking to cut costs. Engineers at Florida A&M University and Florida State University think they’ve found a resourceful alternative, and it involves embracing the ocean’s own wavy aesthetic.  

For  a study recently published  in the journal Engineering Structures, the team built 3D-printed models of several low-rise buildings with wave shaped walls and roofs and tested them in a wind tunnel. The designs with the deepest waves, (in this case 10 percent of the building’s overall height) cut peak wind pressure near roof and wall corner by up to 60 percent. Those corners and edges are where damaging forces typically concentrate. Surprisingly simple designs like these could become increasingly attractive to develop in the coming years, as more and more communities brace themselves to endure stronger and more frequently occurring storms. 

“These nonconventional building shapes reduce the damage from worst-case severe weather scenarios,” Pedro Fernández-Cabán, a study co-author and Florida State University civil engineer, said in a statement. “It’s another tool for engineers and designers to protect against wind damage.” 

Bigger waves means better protection 

To test their idea, Fernández-Cabán and his colleagues started by 3D printing various models of low-rise buildings. Some of the buildings had wavy walls and roofs, while others were built with a more conventional baseline model with flat, straight surfaces. They made three wavy versions, with wave amplitudes of 5 percent, 7.5 percent, and 10 percent. The amplitude  measures the wave’s size in proportion to the building’s overall height in feet. So, for a 20-foot-tall building, a 10 percent amplitude would mean waves that extend about 2 feet.​​​​​​​​​​​​​​​​

Once the models were printed, the team then put them into a wind tunnel at the university. They measured wind pressure data on their surfaces as wind pelted the modelers from various directions. All of the wave-roofed models experienced reduced wind load compared to the flat version. The deepest wave model performed the best, reducing peak wind pressure near roof and wall corners by between 40 and 60 percent compared to the flat version. At least in theory, that means a building with that design could see significantly less damage when exposed to hurricane-force winds.

The paper includes a useful diagram (above) that breaks down why this wavy design works. When wind flows over a flat surface like a roof, it separates at the leading edge and from a single large, swirling vortex. That creates a zone of low pressure, while higher pressure underneath the building pushes out against the surface. That leads to a suction like effect that, in extreme scenarios, can peel roofs off of a building. Over a wavy surface, the wind skips along like a stone across a lake, forming a series of smaller swirls instead of one big one. That disruption to the wind can prevent high-suction picks from forming. The result is a building that with less exposure to the strongest, points many damaging wind forces than a flat one. 

“Changing a building’s shape can significantly reduce the intensity of wind forces it has to withstand,” Fernández-Cabán said. 

The researchers caution that this study focused specifically on wind pressure on the model’s surfaces. They’re now running additional experiments to better understand how wind flows around the wavy structures and plan to use computer modeling to fine-tune the wave patterns and test other shapes. If that work bears out similar to  the early results, it could make wavy walls and rooms all the more attractive to architects and engineers looking for simple solutions to protect buildings in storm prone areas.

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Just over 40 years ago, what began as a routine safety test at the Chernobyl nuclear power plant (or Chornobyl in Ukrainian) in Soviet Ukraine spiraled into one of the most recognizable disasters of the 20th century. The reactor exploded and burned, spewing chunks of nuclear debris into the sky. Among that toxic litter were countless tiny “hot particles,” fragments of nuclear fuel smaller than the width of a human hair (somewhere between 8 and 50 micrometers across). Those particles are called hot because they’re highly radioactive, and still are four decades later. Today, scientists entering the areas of the Chernobyl Exclusion Zone where the hot particles are located are required to wear a full protective suit.

But after decades of study, scientists still know surprisingly little about what their particles are made of at the molecular level. A team of researchers from Germany recently set out to change that by analyzing six particles collected from two sites in the Exclusion Zone using synchrotron X-ray diffraction. Surprisingly, they discovered the particles remained far more chemically stable than they had expected. Their crystal structures were largely intact, suggesting they changed little since forming during the disaster and its aftermath.​​​​​​​​​​​​​​​​

The findings were recently published in the Journal of Hazardous Materials. 

What are Chernobyl’s hot particles?

The hot particles thrown out of the Chernobyl plant fall into three general categories. The first is fuel that remains chemically and physically similar to the reactor’s original uranium dioxide. The second type consists of fuel that melted during the explosion and fused to its zirconium-alloy protective casing. The third type is fire-damaged fuel. 

As the reactor’s graphite burned for 10 days after the explosion, the intense heat oxidized some of the fuel into other uranium compounds. 

Particles, crystals…and dogs

For this particular study, the team sourced their six samples from two areas in the exclusion zone, and all three hot particle categories were represented. Two came from asphalt in Pripyat, roughly 2 miles from the reactor, while the other four came from farm soil samples in Kopachi, about 3 miles away. 

With the samples selected, the researchers isolated individual particles pulled from the soil, mounted each type to a tiny tungsten electrode, and then sent them to the European Synchrotron Radiation Facility in Grenoble, France. There, a team analyzed the particles using intense X-rays produced by a synchrotron, a circular particle accelerator. The researchers rotated each particle in an X-ray beam, measuring it from roughly 2,000 different angles. Watching how the x-rays bounced off all that material revealed how its atoms were arranged, showing which compounds each particle was made of and, most importantly for this study, how intact its crystal structure remained.

They expected to see particles that had been broken down by years of exposure to the elements. Instead, the crystal structures were still largely intact. That surprising finding suggests the particles are far more chemically stable than previously assumed, holding their radioactive contents locked inside their crystal structures. 

Though some of the particles showed more oxidation (of a loss of electrons when they interact with other chemicals) than others, two showed virtually none at all. Importantly, two of the particles pulled from the same soil near Kopachi included both a sample heavily oxidized and one that was largely untouched. The authors suggest that if weathering from the environment were the cause of the oxidation, then both particles sitting side by side should look similar. Instead, they say the oxidation likely happened during the disaster itself, when the reactor fire baked some of the fuel for days.

That timeline is potentially good news for the areas around the power plant. If the particles are indeed holding onto that radioactive material and not oxidizing, that could mean less harmful material is making its way into the soil and, in turn, the surrounding ecosystem. Still, the researchers quickly caveat any broad claims. These were just six samples, after all. Making any wider claim about the soil in the region generally would require more research.

Though it’s still too early to say with any certainty, that lack of leaching dangerous material into the environment could partly help explain why the exclusion zone has become home to an ever-growing neighborhood of furry mammals in recent years. In fact, the area’s lack of humans has made it a thriving ecosystem for foxes, bears, and bison. It’s a modern, albeit a little unorthodox, example of rewilding. Of course, even in this new frontier, the consequences of a nuclear disaster aren’t totally absent. A recent study of roaming dogs living in the Chernobyl Exclusion Zone, many believed to be descendants of dogs left by their owners during the 1986 evacuation, show distinct genetic differences from dogs in an area just 10 miles away.

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The post Chernobyl particles look remarkably similar to explosion day in 1986 appeared first on Popular Science.

Timekeeping has officially entered its nuclear age. Two independent teams, one in Vienna, Austria and another in Beijing, China have built working thorium-229 nuclear clock prototypes. Rather than track changes in an atom’s electrons the way that current atomic clocks do, these nuclear versions use a laser that’s tuned to the frequency where a thorium nucleus flips between two energy states for potentially even more accurate time keeping. Scientists believe this new approach could one day make the clocks far more reliable than any existing atomic timekeeper. 

To put that in perspective, current atomic clocks can  keep time with an uncertainty of 1 second every 300 million years. Scientists predict that more advanced nuclear clocks could move that metric into the billions of years. That could open the door to probing some of the universe’s hardest-to-measure phenomena, like notoriously elusive dark matter. The Chinese clock and Austrian clock were detailed in a pair of studies published this week in the journal Nature.

“The great advantage of the new nuclear clock in Vienna is that, if you use atomic nuclei rather than atoms, much higher precision is possible in principle,” Thorsten Schumm, a study co-author and professor at the Vienna University of Technology, said in a statement.

How nuclear clocks work 

The world’s network of atomic clocks is already mind-bogglingly accurate. They also underpin a slew of modern necessities, from GPS to internet communication. Atomic clocks work by tuning a laser to the exact frequency of light that makes an atom’s electron jump between two levels. 

Nuclear clocks, as the name suggests, go even deeper. They target jumps inside of an atom’s nucleus.  Lasers focus on vibrations from a single nucleus rather than the whole atom. For those who weren’t paying all that much attention in chemistry class, a nucleus is tens of thousands of times smaller than the atom surrounding  it.

Keeping time in a nuclear clock requires keeping the laser tuned to the nucleus as it switches between states. This process is sometimes colloquially referred to as “squishing” the nucleus. Squishing atomic nuclei usually requires an enormous amount of energy. However, the isotope Thorium-229, is a rare exception, which is why both teams at Vienna University of Technology and Tsinghua University in Beijing built their clocks around it.

“The basic idea is simple: you have a laser and you have thorium,”  Schumm added. “The laser changes the energy state of the thorium nuclei, and the thorium nuclei are used to stabilize the frequency of the laser.”

Nuclear is still catching up to atomic 

These two prototype clocks are many years in the making. The thorium crystal used for both was grown separately, but around the same time. So far, testing reportedly shows the version in China is about six times as stable than the clock  in Vienna. The Vienna prototype, meanwhile, is reportedly the first nuclear clock that stabilizes itself the way atomic clocks do. Schumm recently told the South China Morning Post this parallel development has led to a  “fierce but friendly global competition.” 

Nuclear clocks may eventually far surpass their atomic forebears, but they aren’t there yet. Researchers estimate the new prototype may drift by about one second every 30 million years. That’s roughly 10 times worse than the cesium clocks that currently define the official second.

Still, researchers expect that stronger, more efficient lasers and better thorium crystals will make each new generation of nuclear clocks ever more accurate, until they eventually surpass atomic clocks altogether. Who manages to get their first remains to be determined. 

The post The world’s first nuclear clocks start ticking appeared first on Popular Science.

Driverless cars, once a distant techno-optimist’s dream, are making their way into more cities, racking up miles and attracting a loyal fan base. They’re also increasingly racking up tickets and driving in ways that would land a human driver in hot water. 

During July Fourth celebrations this year, several Waymo autonomous robotaxis operating near San Francisco’s Golden Gate Bridge reportedly hit technical trouble that led to at least one vehicle driving over an exploding firework with two passengers inside. The riders (who luckily escaped harm) said they smelled smoke coming out of the vehicle and promptly bolted at the next intersection.

A couple of months earlier, a California driver claimed a pair of Waymos cut her off and blocked her from moving forward for nearly 50 minutes, causing a traffic pile-up and frantic 911 call. Halfway across the country, as many as five Waymos in Austin blocked police and emergency crews responding to an active shooting that left four people dead and a dozen injured. 

“The question is not if this is going to turn into a deadly situation for someone, but when,” Austin City Council member Paige Ellis said at a meeting following that incident.  

Human drivers in any of these situations would likely face a confrontation with police and the real possibility of a citation—or worse. But that calculus changes when there’s no one behind the wheel. Across the country, cities and states are still figuring out how to sanction a driverless vehicle that breaks the law, even as the well-financed companies operating them rack up thousands of dollars in parking tickets with seemingly few consequences.

To call the situation a work in progress is an understatement. Many localities that allow these vehicles on public roads still lack clear legal mechanisms for issuing moving violations. Where laws do exist, enforcement remains light-handed. Experts in autonomous vehicle (AV) policy tell Popular Science that this seemingly basic question, “what happens when a driverless car breaks the law?”, is still surprisingly complicated to answer.

“In principle, AVs are licensed drivers and someone owns and operates them,” University of Southern California Gould School of Law professor Gregory Keating tells Popular Science. “They should be treated like any other licensed driver.”

Despite spending years studying this very issue, Keating says the path forward remains hazy. 

“In practice, I don’t know what’s going on,” he adds. 

Driverless cars are racking up parking tickets

Cars breaking laws, whether driven by humans or algorithms, fall broadly into two categories: traffic violations and moving violations. Anyone who’s gotten a parking ticket is familiar with the former, and increasingly, so are driverless cars. In 2024, Waymo, by far the most common robotaxi operating today, accrued over 589 parking tickets in San Francisco and $65,065 in fines, according to The Washington Post. The Post reported another 75 tickets further south in Los Angeles. In Austin, where the company more recently started commercial operations, Waymo has reportedly received 20 parking-related citations as of June 23. Zoox, another robotaxi firm backed by Amazon, also received a citation for parking in a tow-away zone. 

[Related: Why are ‘driverless’ cars still hitting things?]

Cops issuing those tickets basically approach it the same way as they would a car with a human driver. Matthew Raifman, autonomous vehicle and traffic lead at UC Berkeley’s SafeTREC, tells Popular Science that in these cases, it’s the vehicle, not any individual behind the wheel, that’s on the hook–the same as it would be for a human-driven car. Parking tickets already work this way: If you borrow a friend’s car and get a ticket, it’s the car’s registered owner who pays, not the friend who parked it. Since an AV’s registered owner is the company that operates it, that same logic extends easily to driverless cars. A traffic cop who comes across an empty, illegally parked driverless car can simply print a ticket and place it on the windshield. At the end of the day, perhaps after picking up more passengers, the AV returns to a depot where a human employee collects the ticket and sends it up the chain for payment. 

How cops are supposed to arrest a car with no driver 

Ticketing driverless cars for more serious moving violations gets more complicated. Most municipalities still don’t have clear mechanisms for citing these vehicles when they block traffic, make illegal U-turns, or commit other mistakes that would normally lead to tense conversations with police. The core issue is confusion over who is held responsible when no human is actually making the mistake.

If a police officer observes an AV committing a moving violation, they generally flash their lights to signal the vehicle to pull over. Robotaxis are programmed to use their onboard sensors to detect police flashers, though some vehicles have struggled to do so in the past. If the AV pulls over, the officer must determine who the rogue car belongs to. Today, with only a handful of robotaxi firms operating, that detective work is pretty simple. But it could get much trickier in the near future as more AV companies enter the market, or if individuals begin owning and operating their own autonomous vehicles.

“Just because robotaxis are dominant right now doesn’t mean that robo taxis will dominate in the future,” University of South Carolina law professor and AV policy expert Bryant Walker Smith tells Popular Science. “We could have one company that develops the automated driving system, another company that puts it on a vehicle, another company that buys the vehicles.” 

A clear example of how this confusion can play out occurred late last year in Northern California. San Bruno police, conducting a DUI operation, say they spotted a driverless Waymo make an illegal U-turn in front of them. Officers pulled the wayward Waymo over and contacted a human representative through the car’s speakers to report a “glitch.” But because there was nobody behind the wheel, no ticket or citation was issued the way it would have been if a human driver were involved.

“Since there was no human driver, a ticket couldn’t be issued (our citation books don’t have a box for ‘robot’),” a San Bruno Police Department Facebook post explained following the incident reads.

“That’s right… no driver, no hands, no clue.”

“I’ve been in a Waymo but, being a mere passenger, I’ve never poked around in the glove compartment to see if they carry their ‘papers’ around approximately the way that human beings do,” Keating says. 

Worries about AVs breaking the law aren’t hypothetical. A recent CNN analysis of federal government records and social media footage found hundreds of driverless cars running red lights, driving into oncoming traffic, ignoring emergency road closures, and executing other potentially dangerous maneuvers. Around that same time, Waymo temporarily pulled its vehicles from highways following reports from the National Highway Traffic Safety Administration (NHTSA) of at least 13 instances where they drove into active construction zones. The company has since started resuming highway routes. 

Waymo and independent supporters of AV rollouts generally have repeatedly claimed that, even when taking these issues into account, autonomous systems get into fewer crashes and drive safer than humans. Recent research lends credence to that argument in certain cases, but AVs are still limited in where and how they can operate. 

“No technology is perfect, but while human drivers can only learn from their individual experiences, Waymo takes community feedback and applies those safety learnings to our entire fleet,” a Waymo spokesperson told CNN in June.

A new type of ‘ticket’ for autonomous vehicles 

Regulators hope some creative new legislation can help clear up the confusion. California enacted a law allowing police to issue a “notice of noncompliance” to AVs. The whole point of these notices, and why they mark an important step forward, is to create an official record for when an AV makes a mistake, Raifman notes. Those notices are then updated in the California DMV’s system within 72 hours. Prior to this, police didn’t have a clear way to document when an AV violated the law, creating a gap that contributed to uncertainty about how well the technology works in the real world.  

Still, actually punishing human drivers and AVs isn’t a one-to-one comparison. When humans make mistakes, they receive points on their driver’s license. Rack up enough points, and a driver risks losing their license altogether. As Raifman points out, notices of noncompliance attempt to apply a similar deterrent for AV companies. The notices are recorded, added up, and factored into whether state regulators continue granting those companies permits to operate autonomously. Too many violations, especially those causing major traffic issues or injuries, could lead to a company’s permit being revoked. But unlike humans, AV makers don’t have to worry about individual monetary fines for these moving violations.

“It’s an indirect mechanism to enforcement, but it is not enforcement through money and points,” Walker Smith said.

Raifman compares this enforcement method to how regulators manage pollution from power plants. Local governments often grant permits allowing a facility to emit certain pollutants, but only up to a specified amount. If a plant exceeds that or otherwise violates its permit, regulators can issue a notice of violation, which, depending on its severity, can lead to a permit suspension or even cause operation to shut down. 

That’s a different process than the one facing an individual resident who pollutes their own backyard. In that case, they’d likely just receive a citation. In both the power plant case and now with AVs, enforcement relies on an ongoing back-and-forth between corporations and regulators, rather than a single punishment to an individual.

That may make sense on paper, but it’s also frustrating for everyday drivers, many of whom are just now seeing AVs spring up in their towns and on their roads without their input. The frustration shows up in comment sections and forums, with some describing what can seem like two separate rules or laws–one for humans and another for robots and their owners. 

“They pay the fine and just keep doing what they are doing,” one Reddit post on the topic reads. “This is the corporate reality we live in, where corporations are supposedly people, but have none of the responsibilities or need to deal with things like following the law that the rest of us do.”

Raifman believes enforcement and accountability for driverless cars are broadly improving, but he also empathizes with annoyed drivers who feel the status quo is unfair. One major issue contributing to that frustration, he notes, is that the “pain” felt by a human driver and an AV company violating the same law isn’t equal. A robotaxi company accruing hundreds of thousands of dollars in parking tickets can simply shrug it off as a cost of doing business. For a human driver living on a budget, however, just a few tickets can severely impact their finances.

“I think that’s where there’s an asymmetric relationship compared to humans, and I think that’s a source of frustration,” Raifman says. 

Autonomous vehicles are a physical manifestation of growing AI anxiety 

That pent-up frustration stems, in part, from a familiar pattern in tech: innovations move fast, maybe breaking some things along the way, and regulators end up playing catch-up. Right now, cities with the most exposure to driverless cars (San Francisco, Los Angeles, Phoenix, and Austin) have just begun to sort out what fair and consistent enforcement looks like, even as the technology keeps expanding well ahead of it. 

In just the last year, Waymo has nearly quintupled its fleet, from around 700 vehicles to nearly 4,000, according to The New York Times. Zoox and Tesla are both preparing significant robotaxi launches in multiple cities, and changes to federal rules mean many of these vehicles won’t even have visible steering wheels or pedals. Driverless 18-wheelers are already barreling across Texas highways, and the prospect of individual car owners swapping on true hand-off, eyes-off driving features in their own vehicles gets closer every day. 

And even if the AV supporters are right that the technology is ultimately safer than humans, sheer scale means more and more people will end up watching these vehicles behave badly. In a climate where public trust in automation and AI broadly is souring, driverless carmakers may have more incentive than ever to keep their cars from running afoul of the law, not just to satisfy regulators, but because the cars themselves have become a material stand-in for how people feel about AI writ large.

“I think people are going to put a lot of their hopes and fears about AI generally disproportionately on automated vehicles because they’re so visceral and physical and real and obvious,” Walker Smith said.

In Ask Us Anything, Popular Science answers your most outlandish, mind-burning questions, from the everyday things you’ve always wondered to the bizarre things you never thought to ask. Have something you’ve always wanted to know? Ask us.

The post What happens when driverless cars break the law?  appeared first on Popular Science.

Anyone who regularly walks a dog has likely felt the heavy pull of their smartphone to break up the monotony. Though the hustle and bustle of modern life makes multitasking more appealing than ever, distracted dog walking can put the pooch and its owner in dangerous spots. It may also contribute to piles of abandoned, unscooped poop.

That last point comes from a new study published in the journal Society & Natural Resources by researchers at the University of Surrey in England. The team spent 40 hours observing dog walkers across several sites in the Surrey Hills National Landscape southwest of London, to see how they actually behaved on walks. On 11 different occasions, they spotted owners so absorbed in their phone’s enticing glow or tuned out with headphones that they apparently didn’t notice their dog had relieved itself. 

This abandoned dog poop, which the team artfully calls “pet fouling,” wasn’t the result of particularly ill-intentioned owners. Instead, the researchers say it was mostly a matter of distraction from the dirty task at hand. And poop wasn’t the only issue. Distracted dog walkers were also less likely to catch their dogs entering undergrowth or disturbing nearby wildlife and livestock. Unchecked smartphone use, in other words, inadvertently made walkers crappier neighbors.

“Dog walkers are often portrayed as either responsible or irresponsible, but our research shows that the reality is far more complicated,” Tom Roberts, a study co-author and University of Surrey Senior Lecturer in Environmental Sociology, said in a statement. “Most people care deeply about their dogs and the countryside. Problems frequently arise because their attention is divided or because facilities do not match how dog walking actually happens.”

Dog walking: a moral conundrum 

Observing dog-walker habits gave the researchers a glimpse into how people morally negotiate the responsibility of shared spaces in their daily lives. Walking dogs in the protected region, that also includes farmland, means balancing the interests of the dog walkers, the dogs, farmers, and the natural landscape itself. Overall, the team says the majority of dog walkers they observed were responsible stewards. Most consistently picked up after their pets, with some even collecting waste left behind by other animals. They also tended to adhere to other polite conventions, like keeping their dogs on a leash and on specified trails.

But issues arose when digital devices got involved. Unscooped poop tended to happen early in walks, concentrated near parking lots and along busy paths. Dogs weren’t sneakily waiting to poop in unsuspecting bushes or flower beds. They were more or less dutifully doing their business on a schedule. It was their owners who were shirking the job, temporarily blinded by the pull of social media and emails. A researcher describes the scene in the following field note included in the study. 

“Many wore headphones or were on calls,” they wrote. “Some paced a short loop while talking; others stayed by the gate scrolling on their phones as their dogs ran around the field with little supervision.”

The team also interviewed 15 farmers, land managers, and countryside business owners to get their thoughts on how best to share the space with dog walkers. Broadly, the recommendations were to try and work with the walkers, rather than aggressively enforce new rules or restrictions. The study recommends placing plastic waste bins near areas where dogs often poop to make cleanup easier. They also suggested adding dedicated off-leash areas where dogs can run freely without disturbing the environment, as well as friendly signage explaining why fouling the area can be harmful.

“While dogs can deepen human engagement with nature, they also shape how landscapes are encountered and used,” the researchers write in the paper.

Distracted walks aren’t great for dogs, or their owners 

This study took place in the calm, rural English countryside, and even there, some walkers were still drawn to devices. It may be even more likely in urban and suburban areas, where dog walking can often feel less like leisure and more like an obligation to push through. But distracted walking can cause problems for dogs, both physically and mentally.

On the physical side, owners staring at their phones are more likely to miss their dogs gobbling a sharp bone or other dangerous litter that could wreak havoc on their guts. They also might not see or hear the signals their dog is sending, like if they are getting tired, which could lead to injury. Dogs communicate with us mostly using body language, so when they look up only to see their owners far away in cyberspace, it can make them frustrated. Distracted walkers also might not notice another reactive dog nearby until they are so close that a scuffle breaks out. Listening to music, especially with noise-canceling headphones, can also drown out the subtle sounds of quickly approaching cyclists or, more frequently these days, e-scooter riders.

“When an owner is more attentive to their surroundings, they can be proactive versus reactive to these things,” University of California Davis Veterinary Medicine Professor of Clinical Animal Behavior Science Melissa Bain said in a recent interview with HuffPost.

Mentally, distracted walkers give more attention to their devices than to their pets, leaving the dog confused. Dogs have evolved to look to our eyes for information, including feedback that reinforces whether they did something good or bad. When they check in and there’s no connection, wires can get crossed. They can also get anxious if they don’t have enough time to sniff around on their walk, something that can be exacerbated by a distracted owner hurrying them along. Some Animal behaviorists liken dogs sniffing things on their walks to reading the newspaper or, perhaps more fitting in this case, checking social media.

And though the University of Surrey researchers have recommended more cooperative ways of dealing with unscooped dog poop, others are taking more assertive action. Apartment complexes around the United States are increasingly using services that collect discarded dog poop, take DNA samples from it, and trace it back to its owners to issue fines. In some cases, companies that act as the “Poo Police” have even appeared in eviction court.

That’s all a lot of trouble that could potentially be avoided by taking a brief break from screens and being present. Past research has even shown that dog walking and seeing your dog have fun can improve the dog walker’s mood. 

So, put down the phone and pick up some poop. 

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The post Dog poop not picked up? Blame people staring at their phones. appeared first on Popular Science.

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

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

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

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

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

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

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

The journey to 104 brain scans 

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

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

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

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

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

Don’t sleep on Friends  

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

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

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

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

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

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

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

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

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

But is she sick of sipping coffee at Central Perk?

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

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

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

“Yes, definitely.”

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

Much like the earworm “The Song That Doesn’t End” from Shari Lewis’ Lamb Chops’ Play-Along, a new soft robot does not stop…curling up and jumping. A team of mechanical engineers from North Carolina State University say that they’ve created the bracelet-shaped bot that moves indefinitely when it’s exposed to infrared light. 

Called a Ring Leaper, the teardrop-shaped machine is made of a liquid crystal elastomer ring with a more rigid aluminum V-shaped tail at the end. The ribbony-soft part contracts and tightens when exposed to the light. It keeps curling in, getting tighter and tighter (and building up more energy) until it reaches a “critical threshold” and folds onto the metal part. At that point, the V-shaped aluminum aggressively snaps downward, smacking the ground and launching the robot forward or into the air. 

But Ring Leaper doesn’t quit after that. As soon as the bottom part snaps down, the ribbon part of the body will start tightening around itself all over again. This team of researchers at North Carolina State University says this results in a new kind of robot system that “autonomously stores, releases, and recycles elastic energy.” 

Their mechanical jumping bean can leap either straight up or forward, depending on the angle of the V-shaped bottom part. And it has some hops. The tiny Ring Leaper can achieve a vertical leap exceeding 80 times its own body height. That would be the equivalent of LeBron James (six foot nine inches) leaping 540 feet into the air. That’s taller than a 50-story building. The team recently published their findings in the journal PNAS.

Ring Leaper can hop over hurdles and swim like a frog 

Ring Leaper wasn’t limited to a sterile lab environment. It can tackle small obstacles like grass, rocks, and mulch. It can even swim… sort of. One of the tests involved placing Ring Leaper into a shallow tub of water before shining infrared light on it. On cue, it started its curling-and-jumping routine, but this time it would slightly pop out of the water and gradually wade forward like a frog. Ring Leaper was also able to clear a pair of tiny hurdles, even after slightly tumbling over the first one. When tasked with jumping headfirst into a tall wall, the robot dutifully complies, then whips backward and continues jumping back in the direction it came from, in a kind of mirroring effect. None of this, it’s worth saying, is really programmed or coded instruction. Ring Leaper just jumps.

Controlling Ring Leaper’s mode of movement is also pretty low-tech. The team can dictate whether it jumps straight up, propels itself forward, or goes somewhere in between by adjusting the angle of the V-shaped aluminum tube at its base. A V-shaped angle wider than 120 degrees will result in a crawling motion. Reduce that angle to 90 degrees, and it will leap forward like a frog.  A narrower opening below 50 degrees results in a dramatic vertical jump. Each of those movements is also determined in part by the strength of the infrared light shining at it. More light equals more power. 

“We could also improve the robot’s jumping distance by adding a small amount of weight to the rounded end of the teardrop,” Fangjie Qi, a North Carolina State postdoctoral researcher and study co-author said in a statement. “This changes the robot’s center of mass and leads to a more powerful and stable forward motion – much like a swimmer leaning forward as they dive off the starting block.” 

So what’s this forever jumping robot actually useful for? Well, for now, nothing. Like a great deal of important scientific research conducted over many decades, the team essentially made it because they could, with no obvious commercial or practical application. That still doesn’t mean it’s completely useless. The proof-of-concept robot marks an advancement in self-resetting jumping, which could help other engineering teams who are looking to integrate these findings into future robotic navigation methods. 

The post Bracelet-shaped robot just keeps jumping appeared first on Popular Science.

What began as a routine police response to a reported break-in turned into a brief standoff between nature and technology. Last week, law enforcement in the city of Kirkland, Washington (just northeast of Seattle) responded to a 911 call from a resident reporting loud banging inside their home. Officers arrived expecting a human intruder, but were instead greeted by a more literal cat burglar: a trapped and confused bobcat. 

Not wanting to risk a claw to the face, the officers backed out and reassessed the situation. They ultimately decided to deploy a remote-controlled drone into the house, to monitor the feline intruder from a safe distance. Video captured from the drone’s perspective and released on Facebook, shows the frustrated bobcat standing by a staircase, growling and arching its back at the hovering machine. After a brief standoff with the buzzing, metal alien, the bobcat carefully retreated, sidestepping into an adjacent empty room.

Police were then able to close their door and keep the bobcat isolated until a team from the  Washington Department of Fish and Wildlife arrived. Wildlife officials then sedated the cat, loaded it into a crate, and transported it to nearby Forbes Creek. The feline was then released back into the wild, startled but safe. As for how a bobcat ended up in the house in the first place, Kirkland Police believe the adventurous intruder climbed a tree and jumped through an open window, possibly lured in by the resident’s indoor cat. Both the owner and its likely shocked cat were unharmed, according to the police. Thankfully, curiosity didn’t kill this cat.

The Kirkland Police Department did not immediately respond to Popular Science’s request for comment. 

The aerial deployment was made possible by a public safety drone program the Kirkland Police began in 2022. Today, they reportedly maintain five drones and have 17 FAA-licensed pilots ready to operate them. The typical use cases for those drones include search and rescue, tactical search, scene documentation, and, apparently, bobcat removal. 

Drones are changing the way police surveil wildlife…and people 

Drones and robotic dog-like quadrupeds are reshaping how local communities approach wildlife management. In Japan, authorities deploy a combination of camera-equipped drones and robotic Monster Wolves to locate and deter bears following a record spike in human-bear encounters driven by urban sprawl and declining farmland. In the United States, police in Santa Fe, New Mexico, recently used an aerial drone to track an errant bear wandering near a school. Expanded drone programs are also playing a greater role in locating lost or missing pets. Just last month, firefighters in t Florida used a remotely controlled drone to find an overly adventurous dog trapped in a storm drain. 

But this increased prevalence of drones comes with other, more controversial concerns as well. Police forces around the country are ramping up “drones as first responder” programs, which civil liberty critics say could introduce unreasonable surveillance. Law enforcement around the country has already used these drones to monitor political protesters. Meanwhile, Immigration and Customs Enforcement (ICE), is reportedly interested in using Boston Dynamics’ quadruped robot “Spot”  to aid in immigration operations. Private security companies like Flock and Axon are also investing heavily in aerial surveillance drones. 

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With the dog days of summer nearing an end, many are counting down the days until they can give the darker clothes in their wardrobe a bit more love. Though plenty of people flout seasonal rules and wear all-black year-round, light-colored fabrics are typically the better choice during  hotter months because they reflect sunlight and can help keep us cool. This heat-reflecting logic is also partly responsible for the old decree, “don’t wear white after Labor Day!” But what if fashion choices weren’t dictated by the weather? A team of researchers from China and Australia believes they may have cracked that code, and it starts with a rich purple fabric.

The researchers, hailing from Zhengzhou University and Adelaide University, set out to create a dark-colored material that was also effective at keeping people cool. They created an entirely new fabric made of a purple metal-organic framework and zinc oxide nanoparticles. The metal-organic framework which absorbs green light from the sun and gives the purple color, while the zinc oxide nanoparticles which reflect sunlight and radiate heat away. 

The material performed exceptionally well during testing. It reflected an average of nearly 88 percent of sunlight and stayed up to 11 degrees Fahrenheit cooler than conventional purple cotton outdoors. It was notably even 7.6 degrees cooler than white cotton. In a world where deadly hot summers are becoming more common, research suggests materials like this could provide outdoor workers with some much-needed relief. 

“We have traditionally had to make a choice between cooling performance and appearance,” Adelaide University materials engineer Jun Ma and study co-author said in a statement. “Our research shows that we can have both. We can make a fabric that looks purple, but at the same time reflects most of the sun’s energy and releases heat very efficiently.”

The team published their findings in the journal Small. 

Why do light colors feel cool?

Generally speaking, lighter colors are better bets for staying cool because they reflect more sunlight. White or unpigmented materials are the best at beating heat, whereas dark black material will feel the hottest.  This same idea applies to building and construction materials as well. Purple, while obviously dark, is also a unique choice for the research because it strongly absorbs green light, which is one of the strongest parts of the solar spectrum. 

Caveats are in order, though. Color isn’t the only factor in staying cool. Clothing material and fit are just as important, if not more so. Loose, breathable garments like cotton or linen allow far more airflow than tighter clothing. That’s why Bedouin nomads in the North African desert can wear mostly all black without collapsing from heat exhaustion. Still, all else being equal, lighter colors make for a cooler experience.

Making a cooling, purple fabric 

To create the fabric, the team combined a purple ZIF-67 metal-organic framework with zinc oxide nanoparticles. Using electrospinning, they spun the mixture into purple thermoplastic polyurethane fibers, which were then woven into fabric. They then cut the material into two-inch squares and exposed them to direct sunlight on a sunny day in Zhengzhou, China, alongside control squares of standard white and purple cotton.

The revised material reflected an average of 87.6 percent of solar radiation. In terms of overall cooling, at least in these tests, it was a resounding success. After a full day baking in the sun, the fabric remained 7.6 degrees cooler than white cotton and 11.2 degrees cooler than traditional purple cotton. The fabric also  achieved these thermal gains without sacrificing practical performance, and  was flexible, stretch-resistant, and highly breathable, allowing moisture to evaporate effectively rather than trapping sweat. It also maintained both its rich color and cooling properties after 50 wash cycles. Furthermore, UV accelerated-aging tests (simulating roughly 108 days of intense sunlight exposure) showed that the  cooling performance did not degrade over time.

Using science to stay cool in a warming world 

It’s still early in the process, but the team believes their new approach could make darker-colored materials less off-putting during warmer weather. While that’s potentially great news for all the goths out there, the researchers emphasize far more practical applications as well. These refined fabrics could be used to make workwear for construction workers, farmers, and others who endure long hours baking in the sun. For outdoor laborers, even modest cooling relief can make a life-saving difference.

“The long-term opportunity is to move beyond the idea that cooling fabrics have to be white,” Adelaide University Chemical Engineer PhD candidate and paper co-author Yangzhe Hou said in a statement.

This summer’s heat has moved from unpleasantly hot to deadly in many parts of the world, and it’s likely a sign of more to come. Both the fashion industry and the general public are already adapting to this brutal new reality. A 2022 New York Times report noted a marked rise in sales of shorts and sandals alongside a sharp decline in fleece and heavy outerwear in recent years, a shift attributed in part to rising global temperatures. Similarly, recent efforts to normalize wearing shorts in office settings and the gradual removal of neckties reflect a workplace culture adjusting to a hotter climate.

The new purple fabric research also joins a now lengthy list of other attempts to apply science and technology to make clothing cooler. An assortment of (often more expensive) cool-tech clothing brands with names Coolcore and Iso-Chill have gained popularity, promising to beat the heat. Kontoor Brands, which owns blue-jean giant Wrangler, even made an Insta-Cool shirt that used phase-change material initially used by NASA astronauts to stay cool. 

The post New fabric stays cooler than white cotton—and it’s purple appeared first on Popular Science.