Popular Science

The opium poppy (Papaver somniferum) has a weird double life. The plant’s seeds give a tasty, nutty flavor to bagels, breads, and cakes in bakeries around the world. But the plant’s seed pods also give the class A drug heroin its numbing and euphoric effects. 

That’s because the seed pods exude a milky substance called latex, which is rich in natural chemicals called opiates, such as morphine. Dried-out poppy latex is called opium, and the chemicals it contains can be used as medical-grade painkillers or processed to make street drugs like heroin. 

This doesn’t mean that your next deli bagel is going to send you into a stupor, because processed poppy seeds are carefully washed of any residual latex. But the washing process isn’t so thorough as to remove all traces of opiates from your body. Here’s why anyone in a job that requires random drug tests should try their next bowl of porridge without adding any black little poppy seeds. 

Processing a poppy plant

The round structure that sits on top of a poppy plant’s stem is called a capsule. This is a pod that contains hundreds of tiny poppy seeds. The plant produces opiates, like morphine, codeine, and thebaine, within the capsule to help it grow. These are contained in the milky latex, which will drip from the pod if it’s broken or cut. 

A single poppy pod typically holds hundreds of tiny poppy seeds. Video: Poppy Seed Harvest!, @Freedom_Flare

During harvesting, poppies that have died and dried out are mechanically harvested, removing the above-ground portion of the plant. Crushing, sieving, or other cleaning techniques separate the seeds from the seed capsules. The seeds that later end up on our bagels and breads are washed seeds, meaning they are carefully cleaned after being separated from their seed capsules to remove any opiate-containing latex. 

This process means there isn’t any risk of getting high from washed poppy seeds. However, drug tests are incredibly sensitive, and these washed seeds may still trigger a positive result from trace chemicals. 

Urbah Viqar, a doctor at Central and Northwest London NHS Foundation Trust, says that if you eat “one to two teaspoons” of poppy seeds, then you could return a positive opiate result. Given that some poppy seed bagel recipes recommend sprinkling a teaspoon of seeds on a single bagel, these breakfast treats should be treated with caution if you might be tested for drugs. 

Importantly, opiates like morphine stay in your system for several days, so avoiding poppy seeds for a while before a drug test is a good idea, Viqar says. Some companies have developed low-opiate poppy seed blends to allow bagel enjoyers to get their fix without risks. 

But this isn’t the whole story. If you eat unwashed poppy seeds, the effects are radically different. 

Yes, you get high off unwashed poppy seeds

In 2023, Viqar heard reports that men were reporting to their family doctors complaining of constipation. These patients, mainly from the local Indian Punjabi community, weren’t blocked up by a lack of fiber. Instead, their symptoms were a consequence of their unwashed poppy seed addiction. 

Viqar explains that in some communities, unwashed poppy seeds have been a traditional remedy for generations. Without washing, the seeds retain the opiate-rich latex released during harvesting. As a result, consuming them can make you feel sleepy and relaxed. 

But opiates are, of course, highly addictive. Viqar and her colleague Noah Stanton, who is also a doctor at Central and Northwest London NHS Foundation Trust, wrote a review summarizing the cases of 16 men, nearly all from the Indian Punjabi community, who had become addicted to unwashed poppy seeds. 

“They start with a very small amount, maybe they’re just taking half a teaspoon,” explains Viqar. Many of the men would grind the seeds and consume them as a dry powder, or mixed with water, or brew them as tea. 

The effects of the unwashed seeds are milder than a powerful opioid like heroin, but that made the patients’ addiction more “insidious,” says Stanton. “It took place over a much more gradual time period,” he adds. The unwashed seeds produce a drowsy, sedative effect. 

But by the time Viqar and Stanton saw them, some of the men had seriously ramped up their poppy habit. Two men, who had each been consuming unwashed poppy seeds for over 15 years, were taking 20 tablespoons of seeds every single day. That dose would contain enough opiates to make someone without a strong tolerance overdose, said Viqar. 

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The risks of too many poppyseeds

An opiate overdose would likely slow breathing until the heart stopped. Viqar wasn’t able to point to any cases she was aware of where people had died from unwashed poppy seeds, but said that there was little research into what a safe limit might be. 

“You don’t know how much is a safe amount, how much is a lethal amount,” she explained. Long-term addiction could also impact a patient’s social life and relationships, said Stanton. Several of the men in the study worked with heavy machinery, which tends not to play well with opiate-related drowsiness. 

Both Viqar and Stanton said that better regulation was badly needed. Unwashed poppy seeds can be purchased in bulk in the United Kingdom and the United States at low prices. Awareness among clinicians would also help, they added. Drug screening questionnaires regularly ask about alcohol and drug consumption. A new question to add to the list, Viqar says, is “Have you ever used poppy seeds?”

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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Dinosaur enthusiasts with deep pockets will have their chance to buy one of the largest and most complete Tyrannosaurus rex specimens ever discovered. Meet Gus, a 12.5-foot tall skeleton that took paleontologists three years to excavate. Auction house Sotheby’s values the specimen at $20–30 million, the highest estimate ever placed on a dinosaur.

Late cattle rancher Gary “Gus” Licking found Gus on his land in South Dakota. For years, Licking came across teeth and small bone fragments on his ranch, and realized more bones may be lurking beneath the soil. To find out, he recruited Thomas Heitkamp and his team from Theropoda Expeditions.

Licking suggested that the team start digging in a 6,500-acre parcel of land. And that’s exactly where Gus was found in 2021. Licking died only one year into the excavation, so he never got to see the complete specimen. The team named the T. rex “Gus” in his honor.

“This specimen took three years to excavate—with the team sometimes working for weeks straight without finding a thing,” Heitkamp said in a press release. “The site was a complex fossil bed and preserved many fossils of the flora and fauna that comprised the larger Cretaceous ecosystem. We documented each stage with quarry maps, inventories, and collection data. In the end, our diligence paid off and we were delighted to discover what turned out to be a huge and incredibly complete T. rex specimen.”

In addition to the three summers it took to excavate, the team also had three years of lab work. In the lab, they carefully extracted the fossil from the rock before the bones could be prepared, cleaned, and identified. 

The skeleton is made up of 183 fossil bones representing 82 percent of all of the dinosaur’s bones, including a well preserved skull, furcula (wishbone), and a completely represented pelvis. Its body is roughly 38-feet long and its skull alone is over four-feet long.

“It really does feel like tackling the world’s hardest puzzle, except we have to find all the pieces first,” said Heitkamp. “All those bones separated for 67 million years that we can now, almost magically, fit back together. There’s something deeply satisfying about that.”

Gus will be up for auction on July 14 during Sotheby’s Natural History auction. The fossil will also be on display to the public at Sotheby’s galleries in New York City beginning on July 1.

“For me the added bonus was knowing that Gus was just one of the many pieces of history hidden in the land that Gary and I loved to share,” added Licking’s wife, Dana. “It will be exciting to see how many others will get to enjoy this spectacular discovery.”

The first T. rex to be auctioned off was a specimen named Sue. Now on display at the Field Museum in Chicago, she was sold for over $8 million in October 1997. Ever since, dinosaur auctions like these have courted controversy. Some critics say that fossils kept in private collections are lost to science. They also believe it encourages finding complete or marketable fossils over scientific study, and could lead to incomplete research.

There’s also the question of the fees private landowners may receive, meaning that the person with the largest bank account may receive favorable access over scientists. Some countries including South Africa, Brazil, and Canada have gone as far as to place heavy restrictions on significant fossils wherever they are found.

The post This T. rex could be yours for $30 million appeared first on Popular Science.

Internet-famous eagles Jackie, Shadow, Sandy, and Luna are not the only residents of their beautiful pine tree overlooking big bear lake. And sometimes, the watchful parents will let their presence be known. 

According to Friends of Big Bear Valley (FOBBV), one of the tree’s most famous residents came close to the eagle family over the weekend. Fiona the squirrel made several appearances overnight between May 30 and 31. During one visit, Jackie decided to send a message to the bushy-tailed rodent.

“Jackie responded with a dramatic slap and some backtalk that reminded us she is not tolerating Fiona while trying to sleep,” FOBBV writes.

The not-so-little-anymore eaglets Sandy and Luna also practiced their squirrel-shooing skills and wing flaps later in the day. 

Fiona is one of the catchall names of the flying squirrels that live near Jackie and Shadow. FOBBV is not sure how many of the rodents are in the area, but Fiona and Fast Freddie (another nickname) have had cameo appearances on the livestream for years. The squirrels will visit the nest from time to time, primarily searching for food scraps. 

According to the United States Fish and Wildlife Service, the nocturnal creatures are San Bernardino flying squirrels, (Glaucomys sabrinus californicus) a subspecies of the Humboldt’s flying squirrel. They can glide for as far as 300 feet in the air and primarily eat truffles, conifer seeds, and lichens. FOBBV volunteers have noted that the squirrels are “very fond of Shadow’s fish tails, coot feathers, egg shells and even crunchy beetles!”

So far, Jackie and Shadow’s eggs and eaglets have not been in any serious danger from the squirrels. The same can’t be said for the tree’s ravens, who destroyed the pair’s first two eggs this breeding season. 

All of the action can be found 24/7 on the eagle nest livestream.

Jackie and Shadow’s 2026 babies: Everything you need to know

It’s been another roller coaster nesting season for Jackie and Shadow, a pair of internet-famous bald eagle parents living in San Bernardino National Forest in Southern California. After two of their eggs were destroyed by ravens in January, Jackie and Shadow laid two new eggs that have successfully hatched.

Chick 1 hatched on April 4 at 9:33 p.m. PDT, while Chick 2 followed on April 5 at 8:30 a.m. Their large nest in Big Bear Valley east of Los Angeles is livestreamed 24 hours a day by nonprofit Friends of Big Bear Valley (FOBBV) and has captivated millions. 

On May 1, FOBBV announced the chicks’ names: Sandy and Luna.

How long will the chicks stay in the nest? 

Chicks usually stay in the nest until 10 to 14 weeks of age.

What challenges do the eaglets face?

Before leaving the nest, the chicks face threats from other birds of prey, including hawks, ravens, other eagles, and owls. Inclement weather can also present challenges for the chicks. In 2025, a March snowstorm resulted in the death of one of Jackie and Shadow’s three chicks.

During fledging, only 70 percent of eaglets survive. One of the greatest threats is from cars that can injure or kill the birds while they scavenge for food on roadkill. 

Who are Jackie and Shadow? 

The pair first got together in 2018 and successfully raised chicks in 2019 and 2022. However, their eggs failed to hatch in 2023 and 2024. Only 50 percent of eagle eggs successfully hatch, so this pair has already beaten the odds.

What happened to Jackie and Shadow’s 2025 eaglets?

In 2025, Jackie laid three eggs that all hatched in early March. On March 13, a strong snowstorm dumped up to two feet of snow and battered the nest with strong winds. Only two of the chicks were visible on the live cam when the storm passed by the next morning. FOBBV later confirmed the passing of one of the chicks. The two surviving chicks were later named Sunny and Gizmo after 54,000 names were submitted by fans.

What happens after chicks fledge? 

Young eagles usually fledge–or leave the nest and fly–when they can flatten their wings and have feathers capable of flight. This typically occurs when the birds hit 10 to 14 weeks of age. Males also tend to take their first flight a little sooner than females. 

According to FOBBV, fledglings from Southern California have been spotted as far south as Baja California, as far north as British Columbia, and as far east as Yellowstone National Park.

About 70 percent of bald eagles survive the fledgling stage. FOBBV does not tag their eagles, so it’s not possible to follow the chicks’ journeys after they flee the nest.

Can I help Jackie and Shadow?

Yes. Environmental groups are currently fundraising $10 million to protect Jackie and Shadow’s foraging area from development. Learn more at SaveMoonCamp.org.

The post Bald eagle Jackie shoos away Fiona the squirrel appeared first on Popular Science.

While swimmers and boaters don’t have to fear sharks or giant squid in the Great Lakes watershed, invasive fish the size of large dogs lurk in the freshwater. Invasive carp have wreaked havoc on the ecosystem for over a century, but officials have hit a milestone worth celebrating in the fight against these mega fish. 

In the past 15 years, wildlife officials have removed 50 million pounds of invasive carp from the Illinois River. That’s equivalent to roughly 5,000 elephants. The removal is part of a broader and coordinated effort to protect the rivers and lakes from this non native species.

Why are carp a problem?

Currently, four species of invasive carp cause harm in the Great Lakes and beyond—bighead carp (Hypophthalmichthys nobilis), silver carp (Hypophthalmichthys molitrix), black carp (Mylopharyngodon piceus), and grass carp (Ctenopharyngodon idella). 

According to the Great Lakes Fishery Commission, all four species were imported to North America to help with pest control in aquaculture facilities in the 1970s. The carp escaped confinement in only 10 years, and have spread to the Mississippi River basin and other large rivers, including the Missouri and Illinois.

Each of the four invasive carp species can weigh more than 100 pounds and grow to four feet from tip to tail. Bighead carp and silver carp generally feed on the tiny plankton in the water, while grass carp eats rooted plants in shallow water, and black carp feed primarily on mollusks and snails. 

“They consume so much food and can exist in such great numbers that they can really reduce the amount of [resources] for resident species of fish,” Peter Alsip, an ecologist with the NOAA Great Lakes Environmental Research Lab told Popular Science in 2024. “They can have indirect effects on the whole ecosystem because [silver carp] are consuming phytoplankton and zooplankton, which are essentially the base of the food web.”

Once inside a watershed, they can reproduce rapidly and compete with native fish species for resources. In areas where invasive carp are abundant, they have harmed other fish species  and interfered with commercial and recreational fishing, according to the United States Fish & Wildlife Service (USFWS). They can also pose a danger to humans, as the giant fish can jump out of the lake and hit unsuspecting boaters.

What is being done to stop them?

Carp eradication measures have been active for over 100 years. These efforts include targeted mass removal efforts, developing barriers to block or impede their movement, and ongoing monitoring. 

Cap being culled in the Illinois River. Image: Illinois Department of Natural Resources.

The 50 million pounds of fish removed from the Illinois River were part of a program focusing on the northern part of the river about 50 miles from Lake Michigan. The removal project is designed to suppress the mostly adult populations of carp living in the area, by limiting their ability to reproduce and reduce their migration upstream towards the Electric Dispersal Barrier System. Located about 37 miles from Lake Michigan, this electric barrier is designed to deter their movement through the Chicago area. It is one of the main tools wildlife officials are using to keep them from further entering the Great Lakes through the Illinois River. Another program in the Illinois River offers fish harvest incentives to commercial fishers in the river’s lower 240 miles. 

“The more invasive carp we remove, the more we reduce their harmful impacts and the risk of them reaching Lake Michigan,” the USFWS wrote on Facebook. “Thanks to these and other efforts to monitor our waters and prevent the spread of invasive carp, Illinois and more than two dozen partners are safeguarding some of our most prized native fisheries, and the Great Lakes regional economy.”

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Dangerous, frontline firefighting jobs may get a bit safer thanks to new heat-sensing sensors designed by NASA. The sensors are made from commonly available household materials, and attach to the bulldozers firefighters use to clear vegetation and brush in a fire’s immediate path, triggering an alarm when temperatures reach extremely dangerous levels.

Knowing when a fire is hot might sound obvious, but many new so-called fire dozers are being outfitted with enclosures to protect their operators from the flames. That’s a welcome change, but it also reduces the operator’s ability to gauge the surrounding heat. These new sensors help solve that problem, protecting the driver and helping prevent the dozers from sustaining too much damage.

The sensor setup is simple by design. It consists of a standard thermocouple similar to those found in a home oven, which is then wired to an LED light in the dozer’s cabin. If the light starts blinking, it’s time to get out of Dodge. 

The entire system is powered by something that’s probably laying around your house: AA batteries. Using a simple power source like this is part of an attempt to make every aspect of the design affordable and accessible. University of Alabama, Huntsville research scientist Ryan Wade emphasized that point in a NASA blog post. He explained that during a recent trial installing the sensor in a fire dozer, his team realized that they were missing a part. Rather than waiting to hear back from NASA and having a custom piece shipped to them, they simply walked down the street to a hardware store and solved the problem.

NASA Wildland Fires Program science integration manager Jennifer Fowler holds an LED light on the dashboard of a fire dozer belonging to the Alabama Forestry Commission (AFC). The LED light is connected to a thermal sensor mounted in the window of the dozer, which turns the light on when the radiant heat from a nearby fire reaches a dangerous threshold. FireSense scientists have been working with the AFC to develop and install these thermal sensors onto these dozers, which they showcased during a stakeholder event on April 23-24, 2026 at the Solon Dixon Forestry Education Center in Andalusia, Alabama. Image: NASA/Milan Loiacono.

“NASA’s expertise in this case comes not in the novelty of the instrument itself, but in figuring out how to solve the problem quickly and integrate that technology into their existing system,” Wade said.

That flexibility is what makes the approach so valuable for firefighters. Alabama Forestry Commission fire analyst Ethan Barrett says the devices so far work “exactly as intended.” In Alabama, at least, officials are planning to outfit their entire dozer fleet with the sensors. The sensor system was developed by NASA’s FireSense project, whose interest in it was twofold. The sensors will more immediately help firefighters on the ground as fire season approaches, but the data they collect will also prove invaluable for future research. By placing sensors in the dozers, NASA will gather reams of data about fire strength and intensity straight from the front lines.

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June 9:Conjunction of Jupiter and VenusJune 21:Summer SolsticeJune 29:Full Strawberry MoonJune 30Asteroid Day

Summer arrives this month and with it come long, sweltering days along with all-too-brief nights. But if you can dodge the fireflies and stock up on mosquito repellent, there’s still stargazing to be done! This month’s highlight is a conjunction between our solar system’s two biggest show-offs. There’s also the summer equinox to consider—along with a very tasty-sounding full moon.

June 9: Conjunction of Jupiter and Venus

Fellow fans of the solar system’s large adult son may have noticed that Jupiter has been rather quiet of late. But fear not! Our big rambunctious lad is back in the spotlight this month, galumphing his way across the sky toward the beckoning goddess of love. The gas giant will  reach his destination early this month, and the result for us earthbound folk will be the chance to witness a Jupiter-Venus conjunction.

The two planets will be at their closest on June 9, when they’ll be spotted lounging happily together above the northwestern horizon just after sunset. There’ll also be a couple of peeping Toms in the vicinity. The twin stars Castor and Pollux will be  peeking  out in space just to the right of the two planets. Spotting these two malcontents might require binoculars, but Jupiter and Venus should absolutely be visible to the naked eye.

June 21: Summer Solstice

There’s an argument to be made that the longest day of the year is always the Wednesday of the current week. But  in a technical sense, the longest day of 2026 arrives on June 21. That’s right—get ready for  the summer solstice!

We tend to think of the solstice as the start of summer, but that’s not technically what the term denotes. Instead, it has to do with the Earth’s orbital axis.

The orbital axis is the imaginary line through the north and south poles around which our planet spins. Like many planets, Earth’s orbital axis isn’t perfectly perpendicular to its orbital plane. It’s tilted at approximately 23.44° and the  tilt remains constant in relation to the orbital plane. This means that as the Earth moves around the sun, the angle at which it leans toward the sun changes. This is the reason behind our seasons!

The solstice is the day when this tilt toward the sun is most pronounced as shown below. 

Solstices fall in June and December, while equinoxes fall in September and March. Image: Popular Science.

On the left, we see the Northern Hemisphere’s winter solstice, while the Southern Hemisphere is tilted sharply toward the sun. Halfway around, the Earth’s axis is perpendicular to the sun, so neither hemisphere is leaning inward. This is the equinox, and  there are two of these every year. On  the right, it’s the Northern Hemisphere leaning toward the sun, marking the northern summer solstice—which arrives this year at 10:22 p.m. EDT  . 

June 29: Full Strawberry Moon

For the last couple of months, we’ve had early full moons. But thanks to May’s Blue Moon, our satellite will wait until almost the very end of the month to emerge in its full sunlit glory. As per the Farmer’s Almanac, the Strawberry Moon’s moniker comes from similar names given to June’s full moon by multiple Native American nations, including the Algonquian, Ojibwe, Dakota, and Lakota peoples. It’s a beautiful and rather poetic name, and a perfect fit for the moon that will rise at the end of this month’s long, hazy summer twilights.

June 30: Asteroid Day

June 30 is Asteroid Day, a day to celebrate the fact that Earth has not been hit by a decent sized asteroid in well over a century. The date was chosen to commemorate the 1908 Tunguska event, the last time the Earth experienced a significant impact. Fortunately for humans, that collision took place in a remote part of Siberia, where it flattened 500,000 acres of forest and caused a shock wave that was felt as far away as Indonesia.

In 2014, the United Nations declared June 30 as a “sanctioned day of public awareness of the risks of asteroid impacts.” So be aware! One of the people behind the idea was Brian May. Yes, the same Brian May who plays lead guitar in Queen. May moonlights as an astrophysicist when he’s not tearing up the fretboard of the guitar he and his father built together in the early 1960s.

When the sun finally does go down, remember that you’ll get the best experience gazing at the cosmos if you get away from any sources of light pollution, give your eyeballs some time to adjust to the darkness, and review our stargazing tips before setting out into the night.

Until next time! 

The post June skygazing: A visit to Venus, longest day of the year, sweet summer moon, and asteroids appeared first on Popular Science.

Blue, green, amber: Someone’s eye color immediately attracts our attention. But there’s something unusual about human eyes: We have a large visible area of white that surrounds the iris. Most other mammals have entirely dark eyes with almost indistinguishable pupils. So why are we different? What is the white part of our eyes actually for?

The whites of our eyes help us connect

Scientists paid little attention to that question until 1997, when Shiro Kohshima, a Japanese biologist at Kyoto University, decided to take a closer look. He compared the eyes of nearly half of existing primates and found that only humans had white in their eyes. 

His theory was that the white part of the eye (the sclera) helps us communicate because it makes it easier to tell where someone is looking. The contrast between the white sclera and dark pupil makes the outline of the eye more visible. We also have more elongated eyes than other animals, which makes it even easier to tell where someone may be looking. 

Following someone’s gaze is surprisingly powerful. It can indicate if they’re telling the truth, draw attention to something, and even help us bond. Language, after all, can be complicated and ambiguous. “It’s important to build up a fast communicative step,” says Fumihiro Kano, a cognitive scientist at Kyushu University in Japan. “White sclera help towards that.”  

The cooperative eye hypothesis 

In 2007, Michael Tomasello, a psychologist at Duke University, expanded on Kohshima’s earlier ideas to develop the cooperative eye hypothesis. He argued that the white sclera are particularly useful for human collaboration. 

For instance, the whites of our eyes help us figure out what someone is focused on. It may even have helped our ancestors hunt together and share resources. Central to his idea was the theory that humans are unusually sensitive to where others are looking.

To test this, he conducted an experiment involving human infants and gorillas, chimpanzees and bonobos. A scientist looked at the ceiling with only his eyes, only his head, or both. 

In an experiment, gorillas rely primarily on head movement rather than eye gaze to know where someone is looking. Image: Shutterstock

Human infants primarily followed the eye direction of the scientist. They looked up nearly three times more often when he glanced towards the ceiling using only his eyes than when he just raised his head with his eyes shut. 

Apes did the opposite, relying primarily on head movement rather than eye gaze. They looked towards the ceiling roughly 2.5 times more often when the researcher lifted his head but closed his eyes. 

Why eye contact is so important for babies

From an early age, humans are particularly sensitive to eye contact. In a study of newborns, within the first five days of their lives, researchers found that babies looked longer at faces whose gaze was directed at them. The ability to actively follow where others look emerges between two and four months, and by eight months it becomes consistent behavior. 

“Eye gaze is a natural pointer which makes it easier to understand each other,” says Kano. “If you look at a human infant, then that infant becomes interested in you.”

Eye contact also helps develop necessary language skills. Having white sclera means that infants can more easily follow an adult’s eyes towards a certain object, hear the name of the object, and develop their vocabulary. Studies suggest that infants who follow eye gaze more frequently at ten months have a greater vocabulary.

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Is the white of the eye the real secret to human connection or is it something else?

However, recently, Juan Perea-García, an evolutionary biologist at the University of Las Palmas de Gran Canaria, questioned how important the white of the eye actually is in communication. 

“The cooperative eye hypothesis taps into the bias of human exceptionalism,” says Perea-García. “That’s why it’s so compelling.” Since Tomasello’s 2007 study that proposed the theory, research has shown there are other primates with white sclera. 

Perea-García also points out that, for some people from South Asia, Africa, and Australia, their sclera is not uniformly white but more pigmented. So he argues that it’s not the whiteness of the eyes that’s important for communication, but the contrast between the sclera and the iris. Chimpanzees also have dark sclera with bright irises which could serve a similar purpose.

But this may not be the whole story. While human sclera are not always uniformly white, we tend to show considerably more of the whites of our eyes than most primates and experiments suggest that difference matters. 

Kano and his team compared how humans and chimpanzees interpreted images of human and chimp eyes. They found that both species were better able to discriminate gaze direction from humans. They then made both images smaller and darker. Chimp eyes became even harder to read than humans. 

Chimpanzees, one of our closest relatives, have almost no white in their eyes. Image: Shutterstock

The team even digitally altered chimpanzee eyes to have white sclera and found that gaze discrimination immediately improved. 

“Our work suggests that gaze visibility depends not only on iris-sclera contrast, but also on the visibility of the overall eye outline,” Kano says. In other words, it’s not just about how well the iris stands out. The white sclera makes the whole shape of the eye more visible against the face, something that’s difficult to discern in the dark eyes of chimpanzees. It’s these features working together that seems to make it easier to follow our gaze direction in poor visibility conditions.

The whites of our eyes also indicate health and age

White eyes may also have another purpose: They make it easier to notice changes in eye color which can indicate significant information about health or age. 

As we get older, the whites of the eyes gradually become more yellow or red because of fatty deposits and more blood vessels around our eyes. This shift can occur more rapidly with poor health or diet. 

However, if the sclera suddenly changes color, it can signal more serious health problems. Severe yellowing is closely related with jaundice, a failure of the liver to filter blood properly, while acute reddening may indicate an eye infection. A yellow or red sclera also affects how healthy others think you are.

Researchers tested this by digitally manipulating pictures of eyes to be more red or yellow. Individuals with yellow or red eyes were seen as less healthy, older, and less attractive. It’s an immediate frame of reference that shows how much information we get from our eyes.

So, next time you catch the eye of someone across the room and smile, take a second to appreciate the importance of the white in their eyes. Without it, that connection might never have happened.

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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Routine checkups for humans are usually straightforward. The doctor tells you what to do, and unless you’re a squirming baby or terrified of needles, you pretty much follow instructions. 

But what happens when the patient is a giant yellow-orange eel with sharp teeth? Things get a bit slippery. At the New England Aquarium, experts need to follow a complicated process in order to get Thomas, a green moray eel (Gymnothorax funebris), ready for his yearly checkup. 

The first step consists of retrieving Thomas from the aquarium’s giant ocean tank. Divers get him into a plastic barrel.Thomas and the barrel are then submerged into a different water tank with powdered anesthetic water, Melissa Joblon, New England Aquarium’s director of animal health, tells Popular Science. 

“We have to be really cautious to make sure that he’s fully anesthetized before we handle him because they can be dangerous,” she adds, “and they’re very slippery and can kind of slither away if we’re not really careful.”

Once Thomas is essentially knocked out, the team lifts him from his sedation bin and onto a rack. They then flush water—with more of the anesthesia agent—which allows him to continue breathing. 

The medical exam is preventative care, meaning the team is on the lookout for any health issues to catch them before they become serious. The session includes a physical exam, bloodwork, a full ultrasound, and an electrocardiogram. The team is essentially investigating the eel’s outsides and insides. 

“We do full routine annual exams on the majority of the animals that live at the aquarium, similar to bringing your cat or dog to a vet once a year,” Joblon explains. 

Thomas is probably 18 to 21 years old, but he was a juvenile when the New England Aquarium took him in. A pet owner donated him after wisely deciding that they couldn’t care for the eel anymore—Thomas was becoming too big. Green moray eels are, after all, among the largest morays—they can be eight feet long.

Here’s to making sure Thomas eels good. 

The post Thomas the moray eel goes to the doctor appeared first on Popular Science.

We’ve all seen the movies. Scientists gear up to chase tornadoes across the Oklahoma plains, competing with each other to get there first. But is the reality of storm chasing anything like the movies? In a new episode of Popular Science’s Ask Us Anything podcast, we ask real life storm chaser, Cyrena Arnold, to untangle fact from fiction and break down what it’s really like to go speeding after tornadoes. 

Ask Us Anything answers your most outlandish, mind-burning questions—from the everyday things you’ve always wondered to the bizarre things you never thought to ask. So, yes, there’s a reason some birds talk like people and no, airplane toilets won’t suck you into the atmosphere. If you have a question for us, send us a note. Nothing is too silly or simple.

This episode is based on the Popular Science article “The real storm chasers of the Great Plains.”

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Full Episode Transcript

Sarah Durn: It’s a balmy Saturday afternoon in Kansas, and you’re driving along a wide open road. You glance in the rear view mirror and your heart skips a beat. Huge, black storm clouds are building in the sky behind you. Lightning flashes. Thunder rumbles. On the radio, an alert blares. A tornado has been spotted not far away.

As you drive as fast as you can away from the storm, a caravan of 10 SUVs whizzes by. What the heck are they doing? Why would anyone drive towards a tornado? 

Little do you know, that caravan is packed with hardened storm chasers, just like Helen Hunt’s character in the 1996 classic film Twister. But is real storm chasing anything like the movies?

Welcome to Ask Us Anything from the editors of Popular Science, where we answer your questions about our weird world, from why do we need braces to how fast would New York City fall apart without people? No question is too simple or too out there. I’m Sarah Durn, an editor at PopSci.

Laura Baisas: And hello, I’m news editor Laura Baisis.

SD: Here at Popular Science, we can’t stop thinking about all the world’s strangest questions, and this week, we have a special interview episode of Ask Us Anything delving into all things storm chasing. Woo-hoo. What is it? Who does it? And is it anything like the movies? Laura, you actually interviewed real-life storm chaser and meteorologist Cyrena Arnold for this episode.

LB: I did. Cyrena is the absolute coolest.

SD: Ah, I wanna go storm chasing with her so bad.

LB: Kinda do and kinda don’t. Kind of a little afraid of it, but also if I’m gonna go storm chasing with anybody, I think a seasoned meteorologist is kind of the perfect person to go with.

SD: Yeah, I don’t know. I might get too scared, but the idea of it seems fun.

LB: The idea of it’s great. Sounds great on paper.

SD: Sounds great. And you also wrote a story for Popular Science all about storm chasers, so before we get into your interview with Cyrena, let’s lay a bit of groundwork here. Can you tell us what exactly is storm chasing?

LB: So it’s a term that’s evolved quite a bit over the years, but Hollywood tornado movies basically get a lot of it right.

In general, storm chasing means tracking a severe thunderstorm where a tornado is likely to form.

SD: So badass. So where do chasers typically go to track these storms?

LB: It varies, but tornadoes primarily happen here in the United States.

SD: Really, you don’t get tornadoes elsewhere?

LB: You do. While tornadoes happen in China, Canada, and even Australia, nowhere has tornadoes like the good old U.S. of A.

We have by far the most frequent tornadoes, as well as the most dangerous storms.

SD: I don’t know if that’s an award you want. 

LB: No.

SD: And when and where do most of these tornadoes happen in the U.S.?

LB: So it can vary a bit. Peak tornado season for the Southern Plains, so that’s Texas, Oklahoma, and Kansas, is from May into early June.

On the Gulf Coast, it’s earlier in the spring, and in the Northern Plains and Upper Midwest—so think North and South Dakota, Nebraska, Iowa, Minnesota—tornado season is more June and July.

SD: And what are chasers actually doing when they go out?

LB: So that’s cool. That all depends on the specific chaser. For a lot of hobby storm chasers, it’s all about getting that great picture or video of a tornado.

SD: Kinda like Glenn Powell’s character in Twisters?

LB: Exactly. So then you have storm chasers with more of a meteorology background. These chasers can collect really important data on these storms, so things like wind speed, direction, precipitation. All of this helps weather forecasters get on-the-ground data that even the most advanced radar might not see.

SD: Okay, so it’s a little more like Daisy Edgar-Jones’s character in Twisters, or Helen Hunt’s character in the original film.

LB: Exactly.

SD: And I imagine the fact that these real-life storm chasers can report things that radars can’t see is really important, right?

LB: Absolutely. Storm chasers in the field can radio back in to the National Weather Service about what they’re seeing, and from there, the Weather Service can issue potentially life-saving warnings.

SD: Wow, so storm chasers are actually saving lives.

LB: Absolutely, and that’s not something I necessarily even realized until I spoke with Cyrena and she talked about how important that is. Storm chasers are able to be the eyes and ears on the ground and help keep people safe.

SD: No pressure.

LB: Yeah, yeah. None whatsoever.

Now, before we get into my interview with real-life storm chaser Cyrena Arnold, we want to hear from you. What questions are rotating around in your brain? Submit your question by clicking the “Ask Us” link at popsci.com/ask. Again, that’s popsci.com/ask, and click the “Ask Us” link.

SD: We’ll be right back with Laura’s interview with a real storm chaser, after this quick break.

LB: And welcome back. Today, we have a very special guest interview. With us is Cyrena Arnold, a meteorologist, author, and host of the Storm Front Freaks podcast. She’s currently based in New Hampshire, where she is the director of product marketing at Atmospheric G2, and importantly, has 20 years of chasing storms.

Cyrena, thank you so much for joining.

Cyrena Arnold: Yeah, you’re welcome.

LB: So first, tell me, how did you get into storm chasing?

CA: Ah, that’s a very good question, and how I got into storm chasing was accidentally storm chasing. So I was born in the southern Caribbean where they don’t even get hurricanes, where the weather is really nice.

And when I was five, we moved to Denver, Colorado, or a suburb of Denver, and all of a sudden one day there was this thunderstorm, and I’d never seen a thunderstorm before, and then there’s hail, and I’d never seen hail before, and there was lightning, and I hadn’t seen that, and then a funnel cloud formed.

LB: Ah.

CA: And it formed a tornado, and the tornado just went across this big field, and I so vividly remember standing in the doorway of my house, looking out at that and going, “Wow.” That’s, that’s cool. 

And a switch flipped in me when that happened. And so I just, I just loved weather, and I have really dedicated my entire life to it, you know, all of my education and every science fair project and everything like that.

So I knew I wanted to study severe weather. I knew I wanted to go to the University of Oklahoma, and when you’re out there at the meteorology school. It was wonderful. My first big storm chase was Cordell, Oklahoma, October 9th of 2001, where we saw seven tornadoes. One was a F3 tornado.

LB: Wow.

CA: And that’s the beginning.

LB: And one thing I think, like, me, myself, and anybody that watches some sort of a sci-fi or some sort of fictional take on a very real thing has to wonder: What do the actual scientists think about this portrayal? So can you tell me, what do you think about the Twister films specifically? Are they at all accurate?

CA: Yes and no. 

LB: Right. 

CA: There are some things about them that are super accurate.

LB: Mm-hmm.

CA: And there are some things about them that are not. I think the, for me, the funniest thing is how successful they are in storm chasing. They make it seem so easy.

LB: Right.

CA: You, you know, we’re out, oh, we’re gonna get in the car, and you drive 30 minutes, and there’s a tornado, and there’s another tornado, and, and no. No. No, no, no, no. The, the real story—

LB: Hmm…

CA: —is that you see a tornado on average about one out of every 10 of your storm chases.

SD: Wow.

CA: So you have a very low percentage rate. And then in order to do that, you’ve gotta forecast this right. You’ve gotta set yourself up in the right place. You’re possibly driving hundreds of miles, and you’re putting in a tremendous amount of time for a couple seconds.

Most tornadoes are very short-lived. They’re small, and there are some bigger ones, but you spend a lot of time and work to be successful, and I’ll go entire years and not see one. That’s probably one of the biggest things is that they just make it look so easy and, and so simple, and it’s not. Some other things that they get right or wrong, there’s always, like, a rivalry, right?

Yeah. Like in Twister, you know, it was Jo and, you know, Jonas and, and they fought. And, in the Twisters movie, same thing, right? You know, these competitive chase teams. This is a hobby that has some of the greatest camaraderie out there, and if you don’t believe me check out a gas station any time you see a whole bunch of storm chasers there.

They’re not fighting in the parking lot. They’re doing stuff together, looking at weather models together. They’re taking pictures together, laughing, joking, playing, like, football together. This is a like, a group thing. And I know when we’re out there with the Storm Front Freaks, we’ll see people that we’ve interviewed on our podcast and that we know and talk to, and you, like, run up to these people and give them hugs and high fives.

You know? You know these people, and we have this common bond.

LB: Yeah.

CA: So there is a lot more camaraderie in it, and very, very little competition.

LB: What about some things if it’s like your group, where you’re going out there and you’re, you’re not necessarily doing pictures and video, you’re doing more research and data.

How is that portrayed in the movies, that side of it?

CA: Yeah. It’s funny because in the movies it seems like everyone’s out there for research purposes. And that’s really cool, and in the 1980s and ’90s, that was absolutely true. Most of the people who went storm chasing were meteorologists. It was for scientific purposes, stuff like that.

Today because of those movies, they’ve made it a lot more popular where a vast majority of the storm chasers that are out there now have absolutely no meteorological credentials. And that’s totally cool. That’s fine as long as you go through a lot of training education, ’cause this is still an, this is an incredibly dangerous thing to be doing.

You can’t just walk out your front door and say, “I’m gonna go chase a tornado today,” or you’re gonna get yourself hurt. So most of the people who are out there are hobbyists. They do it for fun. They’ve taken a lot of chaser education courses and talked with other chasers, and a lot of those people who are doing it for fun or into photography.

They, maybe they want a picture of a tornado. Maybe they want really great storm structure. There are still researchers out there. There are still research projects. You have mobile radar on wheels teams out there with remote mesonet sites, so cars or stations you can move to have weather sensors on the ground, and they are collecting data, and we are still trying to understand how tornadoes form.

And that’s a part of it as well. And then you have the small sliver, fraction of a percent of, let’s just call them YouTuber using yahoos or stuff like that like wanna try to touch a tornado and bring you as close to it as possible, but that’s a real small sliver, so—

LB: Okay.

CA: —storm chasing is an incredibly wide spectrum of what’s out there, and, and I’d say a vast majority of them are out there to witness the beauty of nature and actually don’t have any degree or credentials or education in meteorology at all.

LB: And you mentioned the danger. How dangerous is it really?

CA: That can vary. If you wanna stay back from the storms, and you’re wanting to get storm structure, you wanna see the mammatus, and you wanna see the anvil. Maybe you’re far enough back you can see, like, an overshooting top. That’s, that’s pretty good.

LB: Yeah.

CA: You’ll find yourself okay there. But the hazards aren’t just the tornado. The hazards are downbursts. The hazards are lightning. The hazards are hail. The hazards are flooding, flash flooding. Water and flooding kills more people in weather than all of the different weather perils combined.

LB: Wow.

CA: So flooding is incredibly dangerous.

But if you have properly educated yourself, you understand the storm structure and where these different things are located and understand storm motion and dynamics and thermodynamics—

LB: Mm-hmm …

CA: —it can be done in a relatively safe way.

LB: Have you ever been caught up in a situation that you’ve thought, “Maybe I shouldn’t have gotten myself into this,” or, you know, any, um, dangerous storms?

CA: Absolutely. Absolutely. Uh, I got caught one time in a wet microburst of a storm structure that I didn’t understand, and I have never felt wind and rain like that in my life. I was stuck inside my truck. I couldn’t see anything. It was rocking like I was in a hurricane, and the bed liner in the back of my truck was bowing from how much wind was going through there.

I thought it was gonna pop out and go flying away. My ears popped from this wet microburst. It was crazy. 

LB:  Mm-hmm. Wow. 

CA: I remember when this happened, I was like, “I’ve messed up. This is not a safe place.” I’ve been way too close to lightning. When you’re out storm chasing, that’s just inevitable as well.

So I got a car stuck in the mud one time because the mud out there is a special kind of mud that when it gets wet, that turns into the slickest stuff you’ve ever seen, and unless you have four-wheel drive, you’re not getting out of it. Learned that the hard way, and while running to safety, almost got hit by lightning.

I’ve chased tornadoes at night, ’cause I thought that would be fun, and then I realized I couldn’t see anything. So in, in my early days, in my college days, I’ve made a ton of mistakes, and I’m really lucky to say that I, you know, I learned from all of those experiences.

LB: Do you have… I, I know that this might be like asking, you know, what’s your fav- who’s your favorite kid, but do you have a favorite chase?

CA: Ooh. There was a storm in Clovis, New Mexico May of 2003 that was probably the angriest storm I’ve ever seen, and it was actually, it’s funny, we called her Tina because it was the day we chased her was either the day of or the day after Tina Turner passed away. And you know, and she was a, like, powerhouse, right?

And so this storm was just ferocious. And so we called her Tina, and so I’ll always remember Storm Tina. It had inflow winds blowing into the storm at, like, 67 miles an hour sustained. This thing was just sucking up air from the lower atmosphere and throwing it up high like I had never seen in a storm before.

The teals and the green colors you saw inside the storm from the hail that it was producing in the places that I didn’t wanna be were incredible. This storm was just, it was angry, and it was ferocious. 

There’s also a storm, God, in the early 2000s. I was in, like, Okarche, Oklahoma, and this one, I, was hilarious ’cause we have our old-school video cameras. We’re filming it. We know we’re in the right area. We’re looking at the storm structure. The sirens in the town go off, which gives you goosebumps, and when you’re a storm chaser, is one of the coolest sounds in the world. If you’re living there, that’s terrifying. And we’re looking for it, looking for it, and we, you know, kind of, kind of finally see it at the end, but then we gotta drive away and get to safety.

We go back and watch our video that night, and with the resolution of the video camera, the contrast was better, and there was a funnel and a tornado in front of us the whole time, and we couldn’t see it because of—

LB: Whoa …

CA: —the way the light was and the brightness and the contrast. We were in, like, just this weirdest place.

LB: Just the whole time, it was there? Just—

CA: The whole time, yep.

LB: Hanging out.

CA: Just hanging out, had no idea, and so it was, yeah, and that one was, that, like, that’s just one that, uh, me and, and my friends from college, we just look back at and laugh. Like, to this day, we’re still like, “Oh, yep, you know? That Okarche day, man.”

LB: So when you’re actually out there, how is that whole team setup and dynamic different than it is in the movies?

CA: The movies are funny ’cause it’s almost like there’s the set day. Yeah. Where, where all of a sudden, hey, on the calendar, oh my God, it’s May 1st, tornado season is, is opening. You know, and that’s not how it is at all.

There are opportunities where chasers can get together. There’s storm chasing conferences. They usually happen in the off-season in, like, February, which is nice. But with a changing climate too, we have changing storm times, and we’re actually seeing Tornado Alley shift further east, and the seasons are longer.

We’re seeing it fall more into, uh, February, March in, in the southeastern parts of the U.S.. So people just start showing up, and you start chasing on their own. And once you really start getting into the severe season, yeah, you meet up, and you see other people when you’re out there, and in the gas station parking lots, people are there, and you see each other and can hang out for a bit while you’re staging and waiting for storm initiation or whatever.

But it’s not like they show in the movies where it’s like, “Oh my God, everyone mark your calendar for this day and we’re all gonna meet at this gas station in this small Oklahoma town.” It doesn’t work that way at all, and there’s days you can have a line of storms that form from Texas through the Dakotas, and so storm chasers just spread out all along across that line naturally, and it’s just a very natural sort of process. That’s not as scheduled and not as quick and easy as they make it look in the movies.

LB: There you go. Last question, but I love to ask scientists this one, whether it be from movie, TV, comic books, books, favorite fictional scientist?

CA: Miss Frizzle. Does she count?

LB: Oh, 100%. She, she definitely has a PhD, but is also teaching elementary school as a scientist, yes.

CA: You know she’s a teacher—

LB: Mm-hmm.

CA: But man, Miss Frizzle embodies everything about science, the curiosity, the willing to learn, making mistakes and trying again, and also, like, rocking outfits.

LB: Yes.

CA: Like, really cool science-y dresses and stuff while doing it, and making science fun, and I think that is awesome. I am so … I’m game. That’s great. Sign me up. She’s amazing.

LB: Cyrena, thank you so much for joining us. Now, if people wanna find you on the internet, where should they look?

CA: Everything for me is at wxcyrena, and Cyrena is spelled really unusually. Thank you, Mom and Dad. Love you so much. It’s C-Y-R-E-N-A, so W-X-C-Y-R-E-N-A on all the social media platforms.

My website, everything is at wxcyrena. And find me. Find me on social media. We’re gonna be talking about the storm chase while we’re out doing it, so check in and see what’s going on there. And we were just talking about Miss Frizzle. She’s one of my favorite people, and I am trying to be her, I think, more and more every day.

I’ve written three children’s books about weather, too, and so you can find those through the links in trying to find me. I have The Weather Story, The Hurricane Story, and The Tornado Story, which are factual books, real meteorology, but in a nice, lyrical, easy to understand way for kids, and it’s just so important to me that science communication and science education piece is a cornerstone of what I do, so go check those out, too, if you’re looking me up.

LB: Awesome. Well, thank you, and good luck chasing.

CA: Thank you. I hope you find some wonderful, what we, other people call terrible, weather.

SD: What an interview. Now I really wanna go storm chasing with her.

LB: I know. I’m more convinced now. 

And that’s it for this episode, but don’t worry, we’ve got more episodes of Ask Us Anything live in our feed right now. Follow or subscribe to Ask Us Anything by Popular Science wherever you enjoy your podcasts.

And if you like our show, leave a rating and review.

SD: Our producer is Alan Haburchak. This week’s episode was based on an article written for Popular Science by Laura Baisis.

LB: Thank you, team. Thank you, meteorologists and storm chasers, and thanks everyone for listening.

SD: And one more time, if you want something you’ve always wondered about explained on a future episode, go to popsci.com/ask and click the “Ask Us” link.

Until next time, keep the questions coming, and listen to those storm warnings.

LB: Seriously, they’re very important.

And seriously, watch out for flying cows.

SD: Moo.

The post Is storm chasing really like the movies? appeared first on Popular Science.

A team of engineers at the University of California San Diego (UCSD) have developed a humidity-based image encoder that looks straight out of James Bond’s Q-Lab. The postage stamp-sized chip can store a hidden message that is only revealed when exterior humidity levels surpass 60 percent. The image can then be concealed again by bringing humidity back down. In practice, that means someone handed an object with the chip on it could simply breathe on it to unveil its secret message.

While it’s a potentially nifty tool for an undercover spy, the researchers say the encoder could also be used to reveal a security code on a credit card, or even serve as a visual indicator of climate changes in a particular area. In all of these cases, humidity essentially acts as a key. The findings were recently published in the journal Light: Science & Applications. 

“You can imagine using this as a built-in security feature with the environment acting like a key that unlocks different pieces of information,” study co-author and UC San Diego electrical and computer engineering postdoctoral researcher Asad Nauman said in a statement. 

In a video demonstration, a clear blue image of a UCSD trident logo appears and then quickly begins to fade as the area around it brightens. After only a few seconds in, the UCSD library logo emerges. The image then fades back to the man with the trident before switching back once more to the library logo.

Hiding a message in plain sight 

The chip consists of two separate hydrogel layers. The bottom layer, made of a phase-changing material called antimony trisulfide, essentially acts as a canvas onto which lasers can etch messages. These can be text or, as in the example above, full images. The top layer is made of a softer hydrogel material called azido-grafted carboxymethyl cellulose. This layer swells in humid conditions and shrinks in dry ones, which is why the hidden message becomes visible.

The transformation of the UCSD Triton logo to the UCSD library logo. Left to right: The UCSD Triton logo is visible at a 40% humidity level; the UCSD library logo begins to appear and overlap the Triton logo at a 60 percent humidity level; the UCSD library logo is solely visible at an 85% humidity level; and both images are overlapped at a 95 percent humidity level. Image: NDAO Lab

The first, low-humidity image or message is visible when humidity levels are at or below 40 percent. As humidity levels approach 60 percent, the hidden message starts taking shape. It is   then fully visible at 80 percent humidity. The image reveal is also accompanied by a color shift due to small gaps between the two hydrogel layers. When the top layer swells and expands, the increased space between the layers alters the way light reflects off them, resulting in a shift from blue to red.

Of course, for any of this to work, a spy or other user would need to operate in an area with a predictable climate. Blowing on a message in a tropical environment where the air is already thick with moisture probably won’t  do the trick. Still, in a pinch, it might beat having to write out long, intricate messages on finicky invisible ink.

The post Breathing on this chip reveals a secret message appeared first on Popular Science.

Attention creative souls! While NASA might feel like an exclusive den of scientists, engineers, and otherworldly athletes, the agency is reaching out to storytellers and artists via two new initiatives.

“As NASA pushes the boundaries of exploration and innovation for the benefit of humanity, the agency is looking for partners to share mission stories covering Artemis Moon missions, nuclear propulsion, aeronautics, and more,” NASA wrote in a press release. Since “journalists” aren’t mentioned in either of these calls for creatives, it would appear that NASA is seeking other means to keep people talking about its missions. 

Specifically, they are seeking proposals from creatives including documentarians, songwriters, storytellers, and poets for projects about missions including Artemis III in 2027 and Space Reactor-1 Freedom to Mars in 2028, among others. Proposals are due by the end of June.

NASA is also launching another creative initiative called Moon Joy June. 

“To keep the Moon Joy alive after the Artemis II mission, NASA is hosting a month-long art challenge on Instagram, Threads, and Tumblr. Each week during the month of June 2026, NASA will provide a prompt to inspire participants to make and share their artistic creations,” they explain in an FAQ page.

The prompts have already been released, so artists looking to participate can already start brainstorming. Week one’s prompt is “launch,” week two will be “moon,” week three will be “crew,” and week four will be “Earth.” 

A note to the competitive-minded—the agency highlights that Moon Joy June is not a contest but an art challenge, meaning there will be no prize. And as if it could get any worse for type-A people, participants don’t actually have to follow the prompts. It seems like we’re in for a free-for-all artistic takeover of the three social media platforms.

Non-traditional art forms like nail art and latte foam art are also welcomed. In NASA’s words, “The sky is (not) the limit!” 

The post How you can help NASA (even if you failed math) appeared first on Popular Science.

A unique turtle is officially getting a second chance at life in the big blue. Last month we reported on a special resident at the Georgia Sea Turtle Center in Jekyll Island, Georgia: a first-generation hybrid sea turtle, the child of a Loggerhead sea turtle father (Caretta caretta) and a Kemp’s ridley sea turtle (Lepidochelys kempii) mother. Nicknamed Earl Grey, the reptile-turned-celebrity has returned to the wild. 

This Hannah Montana of turtles was slated to be released on Wednesday, but on Tuesday the Georgia Sea Turtle Center announced a change of plans because of “some unexpected pre-release complications.” Luckily, these complications must have been resolved. He was sent on his way Thursday morning, only one a day behind schedule. 

“Yesterday evening, veterinarians at the Georgia Sea Turtle Center determined that the best course of action for Earl Grey’s well-being and successful transition back into the ocean was to conduct a private release,” according to a George Sea Turtle Center spokesperson.

The turtle was rescued from a beach in Brewster, Massachusetts, where it was stranded and cold-stunned. The turtle’s mixed background was revealed by genetic testing after the Loggerhead ridley (or Kemp’s Loggerhead?) arrived at the turtle center. Hybrid animals are natural, but we don’t know how many wild hybrid sea turtles there are. Most hybrid animals are only confirmed with genetic testing. 

Earl Grey on his way to the beach for release. Image: Jekyll Island Authority.

“From an evolutionary perspective, hybridization could be one of many ways genetic diversity is introduced into a population,” Jaynie L. Gaskin, Georgia Sea Turtle Center director, told Popular Science in April. “We encourage other rehabilitation facilities to consider genetic testing for any suspected hybrid sea turtles, as there may be more individuals than we currently realize!”

In a Facebook video, the turtle center highlights the traits that the rare hybrid sea turtle inherited from each species, including a hook-shaped beak of a Kemp’s ridley (the mother) and the colors of a Loggerhead (the father). A combination of, in their words, the “best of both worlds.” . 

Stay warm, E.G.! 

The post Rare hybrid sea turtle released back into the ocean after rescue appeared first on Popular Science.

This weekend, Earth will be treated to a nice blue moon. Our planet’s only natural satellite won’t put on a pleasant azure hue (indeed, blue moons have nothing to do with color). Instead, it will be the second full moon for the month of May, following the full Flower Moon on May 1. The blue moon will reach peak illumination at 4:46 a.m. EDT on Sunday May 31. 

Seasonal vs. calendrical

According to the Farmer’s Almanac, there are two definitions of a blue moon—a seasonal blue moon and a calendrical blue moon.

A seasonal blue moon is one extra full moon within an astronomical season, or the dates between solstices and equinoxes. A typical astronomical season has three full moons within it. If it has four full moons instead, then the third may be called a blue moon. 

A calendrical (or monthly) blue moon is the one most of us are familiar with. It is the second full moon to fall in one calendar month—like in May 2026. It takes the moon roughly 29.5 days to complete one cycle of phases (new moon to new moon). So if a full moon falls on the first of the month on the calendar, there will be a second full moon at the end of the month. The only month in which a calendrical blue moon cannot fall is February. 

How rare are blue moons?

Blue moons are not quite as rare as the phrase “once in a blue moon” makes it sound. Calendrical blue moons happen every 2.5 years (or 30 months) on average, and seasonal blue moons fall about once every two to three years. 

The last calendrical blue moon was on August 31, 2023 and the next calendrical blue moon will rise just in time to ring in the new year on December 31, 2028. 

Two blue moons can also occur in one year. In 2018, January and March both had two full moons, with no full moon in February. The next time two blue moons will fall in one calendar year won’t be until 2037.

Why is it a micromoon?

May’s blue moon will also be a micromoon and the smallest micromoon of the year. Micromoons have nothing to do with size and everything to do with distance. Typically, the moon is about 238,855 miles away from Earth. Micromoons are further away, and this month’s micromoon will be 252,360 miles away. With the further distance, a micromoon may appear a bit smaller and dimmer than usual. 

On the opposite end of the spectrum are supermoons, which are closer to Earth at only 225,130 miles away.

How to watch and photograph a blue moon

If you want to see the blue moon rise over a historic city, the Virtual Telescope Project will broadcast the event live from Italy. 

NASA has also put together a handy lunar photography guide if you want to snap that perfect moon pic. If using a smartphone, NASA recommends stabilizing the device, turning off the flash, and tapping the moon on screen to focus the camera directly on it instead of the sky. Your brightness also needs to come down and taking pictures at twilight or as the moon clears the horizon will give the sensor less contrast. 

The post Look up for a blue moon on May 31 appeared first on Popular Science.

A pleasant swim at the beach or pool can quickly turn deadly. Every year, over 4,000 people die from unintentional drowning across the United States. 

Swim safety experts say drowning is highly preventable. They recommend learning basic swimming skills, designating “water watchers” to keep an eye on children in the water, and avoiding swimming alone or under the influence.

But what if your outfit could stop you from drowning? Swim safety experts say wearing the right color on your next beach day is a good way to stay visible and out of harm’s way—especially for inexperienced swimmers and kids.

So what are the safest swimsuit colors?

Lisa Zarda, Executive Director of the U.S. Swim School Association, says people wearing bright, neon colors are easiest to spot in pools, lakes, and oceans, while blue, black, white, and gray swimsuits blend into the water. 

“When the water is moving and reflecting the sunlight, certain colors just disappear under the water,” she said. “Especially in open water, where it can be kind of murky and hard to see: The brighter the color, the better.” 

Wearing bright colors helps lifeguards and other safety officials identify and rescue people who are at risk of drowning. Vivid orange and super-bright, highlighter yellow are two standout colors for swim safety.

“Think safety vests and traffic cones,” Zarda said. “Those are bright colors also for a reason—so that they can be easily seen.”

An informal study by Alive Solutions, a public safety group, tested swimsuit visibility in three different conditions: in a pool with a standard light bottom, a pool with a dark bottom similar to dark blue ocean environments, and in an outdoor lake with brown-gray water. 

Across the board, the study identified bright, neon orange as the most visible color. But there was some slight variation of which colors stood out best in different environments. Against a dark pool bottom, neon yellow, green, and orange were the most eye-catching, while even brighter reds and pinks appeared darker, and both light and dark colors faded into the water. 

In a pool with a light bottom, most colors stood out, while light colors like white and light blue disappeared almost instantly. 

In a lake, only neon colors were visible while all other colors quickly blended. So bottom line: stick to a neon orange swimsuit if you want to be sure to be seen.

Dark colored swimsuits can be especially hard to spot in open water. Image: mrs / Getty Images / MARTINS RUDZITIS What makes neon stand out?

All visible color is the result of reflected light. A red apple, for instance, absorbs many wavelengths along the light spectrum, but bounces back red wavelengths. So to the human eye, an apple appears red.

Ordinary colors, like the red of an apple, only reflect the light they receive, but fluorescent pigments do more than that. They also absorb incoming nonvisible ultraviolet and some visible blue light and then re-emit part of that energy as intensely visible light. This is why fluorescent colors almost seem to glow.

Fluorescent shade’s high-contrast is why traffic safety signs, protective gear, and safety and rescue objects, like buoys, are often made with neon materials. It’s also what makes fluorescent swimsuits extra safe.

Swim safety for kids

As summer comes into full swing, Zarda says wearing a neon swimsuit is just one piece of the puzzle to prevent drowning, particularly for kids.

Children are extremely vulnerable to drowning accidents. Kids between ages one to four die from drowning more than any other cause of death, according to the Centers for Disease Control and Prevention. For children aged five to 14, drowning is the second leading cause of unintentional injury.

“Choosing the right swimsuit color doesn’t replace any of the other important layers of protection.” Zarda said. 

“Always having undistracted adult supervision, having a fence around your pool, enrolling your child in swim lessons so that they know how to swim and navigate in the water—those are all still very important.”

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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The post What’s the safest swimsuit color? Skip blue and black. appeared first on Popular Science.

A 31-year-old New York native named Kelsey Pfendler is one week into her audacious quest to become the youngest woman to row unassisted from California to Hawaii. To complete her over 2,400-mile journey, she will need to face stormy seas and traverse waters teeming with all types of ocean life.  If she succeeds, Pfendler will become the first American woman ever to do so.

@yourowkelsey

A couple hours of napping and some food will make you feel like a new woman! Waves and wind are still big, but luckily they are becoming more favorable, allowing Kelsey’s boat to catch and ride the waves. Kelsey is rowing to raise funds for The Whale Foundation an organization whose mission is to support, restore, and celebrate the health and well-being of the Grand Canyon river guiding community. Links to learn more and donate are in our bio. @Concept2 @Recpak @insta360 official

♬ original sound – YouRowKelsey

Pfendler set off from Monterey, California on May 21 and has been posting daily updates on her TikTok. A separate live tracker  also plots her position on a digital map. As of May 28, the tracker shows her off the Southern California coast, moving at 1.6 knots. The multi-month voyage is a major test of physical strength and mental fortitude,  and it’s already proven grueling. In just her first week, Pfendler battled strong headwinds as she pushed away from the California coast, leaving her hands covered in blisters.

@yourowkelsey

Absolutely flying today! Waves are around 14ft and wind maxed about 22mph earlier, which gave her a good boost of speed. 229 miles so far, about 2,000 to go. @Concept2 @Recpak

♬ original sound – YouRowKelsey

And it has only gotten tougher. Pfendler’s route took her directly into the path of a weather front, bringing bone-chilling temperatures and punishing waves. Worse, while taking cover from the waves, she lost the cap to her heavy-duty freshwater bag. Though she has the ability to make more freshwater with a desalination device, it runs on solar power and the storm left the skies too dark and overcast for the device to work. As a result, Pfendler has had to tap into her emergency supply of 25 small water bottles, a scarcity that has also prevented her from using water to rehydrate her freeze-dried camp food.

“It’s tortillas and peanut butter until I get some sun,” Pfendler said. 

But the trip has had its lighter moments as well. Pfendler posted an update sharing her excitement when she crossed the continental shelf. At about 50 to 60 miles off the California coast, crossing the continental shelf is something few humans get to experience so intimately.  She also recounted a moment where she spotted either a sea lion or a dolphin hunting fish nearby, sending them leaping out of the water all around her boat.

“It was really cool, it was in the dark and it was kinda special for me,” Pfendler said, 

This quest  isn’t Pfendler’s first rodeo. She completed a similar rowing trip from California to Hawaii in 2024 with three companions, serving as the skipper. That trip took 40 days, 22 hours, and 14 minutes. Still, rowing in total isolation—even for an experienced oarswoman—adds another layer of challenge. If Pfendler completes the trip, she will be just the third woman ever to do so. The record, set by British rower Lia Ditton in 2020, currently stands at 86 days, 10 hours, and 56 seconds.

The post Kelsey Pfendler is trying to become the youngest woman to row solo from California to Hawaii appeared first on Popular Science.

For decades, scientists have known that Earth’s magnetic field helps migratory birds and homing pigeons navigate. Just how our feathered friends sense the invisible sphere around the Earth, however, has been less clear. 

At least part of the answer appears to be hiding inside a seemingly random organ. Immune cells inside pigeon livers called macrophages are sensitive to the planet’s magnetic field. These cells function like an internal compass, according to a new study published today in the journal Science. 

Macrophages destroy old red blood cells, which makes them accumulate iron. The iron makes the macrophages  superparamagnetic, a kind of magnetism that takes place in particular nanoparticles. The nanoparticles can then be magnetized if a magnetic field is applied to them. 

“When pigeons fly, the nanoparticles align with the magnetic field and become ‘magnetized,’” Clivia Lisowski, a co-author of the study and a post-doctoral researcher in Immunology at the University of Bonn, tells Popular Science. “Like that, pigeons can sense Earth’s magnetic field.”

Electron microscopy image of pigeon liver tissue shows hepatic macrophage (blue) in contact with nerve fiber (yellow), which enables them to transmit (“magnetic”) information to the pigeon brain. Image: Lisowski et al. (2026) Science.

To understand how these particles help the pigeons navigate, Lisowski and her team tracked down where magnetic cells are in pigeons’ bodies. Because the liver and spleen store significant quantities of iron, researchers thought these might be good candidate organs. The  liver had a significantly stronger magnetic response than any of the other tissues in the study, according to study co-author Ulf Wiedwald, an expert in nanoscience at the University of Duisburg-Essen in Germany, 

From there they homed in on macrophages, and put these important immune cells  to the test. They studied  pigeons that were trained to fly back to their aviary in Konstanz, Germany, from over 12.4 miles away. Pigeons whose macrophages had been removed got lost when the weather was overcast. But when the sun was out, the pigeons reached the aviary, probably with the aid of solar cues. 

The findings show  how the birds employ magnetic sensing to find their way, as well as the sun’s orientation. 

“Our study has implications for both the immune research landscape as well as for research on animal navigation or magnetoreception, respectively. For animal navigation it’s a new concept of how animals sense/perceive Earth’s magnetic field,” Lisowski says. “We think that this ferrimagnetic mechanism can actually explain how birds migrating at night, or sharks or bats or other animals migrating in dark environments can perceive Earth´s magnetic field.”

The team also found that the iron-rich macrophages are close to nerve fibers, indicating that magnetic information can get to the brain via this route. Ultimately, this shows how important  interdisciplinary research, involving immunologists, behavioral biologists, and physicists, carries  significance for more than just birds. 

As for the immune system, Lisowski explains that to accomplish its different fuctions—such as defending our bodies from pathogens and healing wounds—it has to sense the environment.

“Our finding that the immune system can also sense the Earth´s magnetic field is a complete new layer in this concept of ‘immuno-sensation’ and opens the door to new research,” Lisowski explains. 

The post Pigeons use their livers to sense Earth’s magnetic field appeared first on Popular Science.

Sunburn and mosquito bites go together in the summer like a hot dog and ketchup. To keep from becoming a mosquito buffet, most of us turn to bug sprays with DEET.  An acronym built from its scientific identification (diethyltoluamide), DEET was developed for the United States Army in 1946 and entered civilian use in 1957. It is generally considered safe when used as directed. 

However, mosquitoes can learn to associate the repellant with food. They may even become attracted to it. The findings are detailed in a study published today in the Journal of Experimental Biology.

“If someone applies DEET and the concentration fades over time, but a mosquito still manages to feed, the insect may begin associating that smell with a reward,” Clément Vinauger, a study co-author and biochemist at Virginia Tech, said in a statement. “That’s a possibility we should take seriously when we think about how repellents are used in the real world.”

Ace processors

Like it or not, Earth’s over 3,500 known mosquito species are pretty smart and an evolutionary wonder. They use sensory information to find hosts and can adapt to changing environments.

In previous studies, Vinauger’s team has shown that the insects remember and avoid hosts who swat them away, can combine smell and vision to precisely track humans, and even gravitate toward and away from the smell of certain soaps.

“Mosquitoes are remarkable at processing information about their environment,” Vinauger said. “What we are trying to understand is not only how they detect us, but how their brains interpret those cues and turn them into behavior.”

A DEET-covered dinner bell?

In this new study, the team focused on the yellow fever mosquito (Aedes aegypti). This species spreads several diseases to tens of millions of people each year, including dengue fever, Zika, yellow fever, and chikungunya.

The team trained mosquitoes using a form of Pavlovian conditioning. Often called “Pavlov’s dogs,” this training method developed by neurologist and physiologist Ivan Pavlov in the early 20th century was used to teach dogs to associate the sound of a bell ringing with food. 

The mosquitoes were restrained behind a piece of fabric mesh. They then offered the mosquitoes a bag of warm blood (yum) that was just out of the insects’ reach to see how enthusiastically the insects stabbed at it with their proboscises. As expected, the mosquitoes were interested in the blood, particularly when the team rewarded them by lowering the bag within reach. Things changed a bit once DEET entered the experiment. When the team offered the insects blood when surrounded by the scent of DEET, they initially stayed away from the potential feast.  

A female yellow fever mosquito (Aedes aegypti), feeding on a bag of warm blood. Image: Romina Barrozo.

To see if they could be trained to associate that smell with the dinner bell, the team fed the mosquitoes warm blood for 20 seconds, squirting the scent of DEET into the enclosure in the final 10 seconds of dining. They repeated the procedure three more times before noting how the mosquitoes responded to only the scent of DEET. In this trial, over 60 percent of mosquitoes tried to bite when they smelled DEET.  

To examine further, the mosquitoes were given a choice between two human hands. The hand belonged to study co-author Ayelén Nally of the University of Buenos Aires. One of Nally’s hands was coated with DEET at normal concentrations and the other was bare. The untrained mosquitoes avoided the DEET-treated hand, while the trained mosquitoes were drawn to it.

Interestingly, the mosquitoes could form that same association when sugar, instead of blood, was used as the reward. 

According to the team, they are seeing how the mosquito’s brain can rewrite its response based on their experiences. What they have learned matters just as much as what a chemical like DEET does. 

“If mosquitoes are repeatedly exposed to DEET, it becomes less effective as a repellent,” study co-author Claudio Lazzari from University of Tours in France added.

Keep the bug spray

Importantly, this does not mean you should stop using DEET completely. It is still one of the most effective ways to keep the dangerous insects away, particularly where mosquito-borne disease is common.

“If you’re in tropical regions where disease risk is real, you should use it,” Vinauger said. “Instead of applying a lot at once, you may want to reapply regularly so it’s always active and providing continuous protection.”

Treated clothing may also be a challenge since DEET concentrations in fabric decline over time. Additional study to understand their behavior is crucial for public health as mosquito-borne illnesses increase due to climate change. 

“We need to understand how mosquitoes keep outsmarting our control strategies,” Vinauger concluded. “And that takes understanding how they work—at the molecular level, the neural level, the behavioral level.”

The post Mosquitoes can learn that DEET means dinner is served appeared first on Popular Science.

Everyone who has ever owned a hamster knows the sound: the small, relentless squeak of the exercise wheel, usually starting around two in the morning.

As you watch your cute furball running toward no destination whatsoever, you might wonder: What’s going on here? Is little Hammy acting out of restlessness or boredom? 

For decades, scientists assumed it was exactly that: a neurosis, an artifact of captivity, the hamster equivalent of doing push-ups in prison. 

But in 2014, researcher Johanna Meijer conducted a study that suggested a less depressing scenario. When wild mice came across a wheel in their natural habitat, they got on the wheel and ran—sometimes for up to 18 minutes at a stretch.

So if it’s not boredom or neurosis (wild mice surely have plenty of more important tasks than wheel running), what is it? 

Dr. Theodore Garland Jr., a professor of biology at UC Riverside, has spent more than 30 years trying to figure that out. 

“There’s still a lot of controversy about what, exactly, wheel running means to an organism,” Garland says. “What is it? What is the organism trying to do?”

Why wild mice run on wheels just like your hamster

In Meijer’s 2014 study, published in Proceedings of the Royal Society B, she and her colleagues placed exercise wheels in two different locations: a green urban area and a dune area not accessible to the public. For more than three years, they recorded wildlife activity at both locations.

They found that wild mice closely mirrored the behavior of their cage-dwelling counterparts. At both locations, the mice frequently ran on the wheels—often for lengths of time equal to the “workout” durations of captive mice.

Although food was initially used to attract animals to the wheel, the researchers found that wheel running continued even after the food was removed. This suggests that the animals not only ran voluntarily on the wheel, but did so without any external reward. 

The wheels attracted more than just mice, too. Shrews, frogs, and even slugs were recorded using the equipment (a few snails were excluded from the study due to “haphazard” movements on the wheel). But wild mice used the wheel far more than another animal, accounting for 88 percent of all wheel runners. 

Hamsters aren’t the only creatures that like running on wheels. Video: Wild Animals Caught On Hamster Wheel, Live Science

So, why do rodents specifically enjoy a run to nowhere? Are slugs simply less committed to their cardio?

According to Garland, rodents are simply built for it—bigger home ranges, faster metabolisms, and the aerobic capacity to sustain speed over distance.

“A toad isn’t going to be running 10 kilometers in a day,” Garland says. “Whereas a chipmunk could be.”

Dopamine keeps mice and hamsters coming back for more

But that’s only part of the story. The more interesting question is why any animal would choose to do it at all.

According to Garland, the drive to run on wheels among free-ranging animals is not fully understood, but the behavior is likely tied to the reward centers of the brain. 

“Dopamine is viewed as the final common denominator,” Garland says, referencing the neurotransmitter that delivers a sense of pleasure to the brain’s reward system. Similar to a human working out at the gym, mice get a dopamine boost every time they run on their trusty wheel. 

In Garland’s own lab, mice placed in larger, rat-sized wheels will sometimes slow down mid-run and rather than jumping off as the wheel keeps spinning, complete a full 360, and keep going. It serves no obvious purpose. It looks, for all the world, like a bit of acrobatics, as if the little mouse is creating its very own roller coaster.

“I’m hesitant to use the ‘F-word’ about lower vertebrates,” he says, “but it’s hard to ignore the idea that they’re getting some sort of pleasure or enjoyment out of it.” 

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The reward system may explain the drive, but Garland sees something even more elemental at work—something similar to the “zoomies” dogs and other young animals get. 

A baby horse, Garland notes, will sometimes just tear around a field for no apparent reason—solo, unprompted, burning energy for the sheer joy of it. “We used to call it nip-norting,” he says, “just going crazy, even without another individual to egg it on.”

Exercising at a young age leads to lifelong habits, even for hamsters

Rodents’ love of running on wheels might even have implications for humans. Some of Garland’s work suggests that, when introduced at a young age, wheel running can become a lifelong habit.

In his study, Garland found that mice given access to a running wheel immediately after weaning, at just three weeks old, ran significantly more as adults.

“It’s got to be something up here,” Garland says, indicating the brain. “Their reward system has been permanently tweaked.”

Whatever it is keeping these little guys running, an early start seems to predict an ongoing practice. The implications, Garland believes, extend well beyond mice. For instance, cutting physical education from school curricula, he says, could be “a huge public policy disaster,” leading to adults who aren’t used to exercising.

“If you’re a kid who never gets to play basketball or tennis,” he says, “and then you get to college, and your friends are playing pickup games, it’s probably not even on your radar to do that kind of thing.”

Of course, none of this is on your hamster’s radar at all. They’re just galloping away, keeping you awake with the endless rotation of their squeaky wheel. But all that running can also lead to some good: Recently, a resourceful young YouTuber rigged his brother’s hamster wheel to charge his phone.  

But no need to worry—the clever teen isn’t exploiting the toil of a joyless captive. Hammy, it seems, is just doing what comes naturally. 

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 Hamsters run on wheels for a surprisingly joyful reason appeared first on Popular Science.

This article was originally featured on The Conversation.

On May 22, 2026, the Pentagon released a second batch of previously classified photos and videos showing what appear to be unexplained flying objects. These file dumps were the culmination of a process that was set in motion back in July 2023, when a group of government whistleblowers testified before Congress that the U.S. government was secretly in possession of extraterrestrial spacecraft and suspected alien body parts.

That congressional hearing marked the beginning of a cultural shift in which UFO reports are increasingly treated as a matter for serious discussion, both within the government and the scientific community.

The Pentagon released over 200 previously classified UFO files in May 2026. Image: Department of Defense

But is this newfound legitimacy deserved? As an aerospace scientist who studies aircraft and spacecraft design, I approach this question using math, physics and the principles of engineering. To assess the plausibility of alien visitors, it’s necessary to understand the obstacles that an extraterrestrial vessel would need to overcome to reach Earth.

The tyranny of distance

There is no evidence of intelligent alien life in our solar system. So any extraterrestrial visitors would likely have to come from another star system within our Milky Way galaxy.

Proxima Centauri, the star closest to our Sun, is located 4.25 light-years (about 25 trillion miles or 40 trillion kilometers) away.

For perspective, if Earth were the size of a pea, the distance to Proxima Centauri would roughly equal the distance between New York and Sydney, Australia.

Even the stars closest to Earth are incredibly far away.

Since only a fraction of stars are thought to host intelligent life, the nearest alien civilization – if one exists – is surely much farther away than Proxima.

A need for speed

Given the scale of interstellar distances, it’s inevitable that any alien voyage to Earth would span many years and possibly several centuries. But as the time spent in transit increases, so does the risk of catastrophic accidents or system malfunctions that could jeopardize the mission. So it’s important to avoid an overly lengthy journey by traveling as fast as possible.

No object can reach or exceed the speed of light (roughly 186,000 miles or 300,000 kilometers per second). But well before approaching that threshold, engineering constraints begin to assert themselves. Limited fuel availability and the potential for structural damage will restrict the spacecraft’s peak velocity.

There is no universally accepted upper limit on interstellar flight speeds, but studies tend to converge around 19,000 miles per second (30,000 km/s) – 10% of the speed of light – as a realistic cruise velocity. At this speed, a journey of 10 light-years will take approximately 100 years to complete.

Fueling the dream

Finding a way to accelerate the ship to its target cruise speed is the central challenge facing any would-be alien explorers.

Interstellar space is unforgivingly vast, but the emptiness has some advantages. The lack of atmosphere means there is no aerodynamic drag. So when the ship reaches its cruise speed, it can shut down its propulsion system and coast toward the final destination. Unfortunately, the lack of atmosphere also means there is nothing to slow the ship down prior to arrival. So ideally, the propulsion system would be used for both acceleration at the start of the trip and deceleration at the end.

One of the more exotic propulsion strategies employs high-powered laser beams to push the ship through space. The beam is projected from a stationary array near the travelers’ home planet and directed toward a thin reflective sail attached to the ship. The beam’s photons exert radiation pressure on the sail, propelling the ship forward.

This approach has a major advantage in that it requires no onboard fuel. But the amount of energy and infrastructure needed to operate the laser would be staggering. Also, beamed propulsion provides no mechanism for deceleration. At best, this method could be deployed as part of a hybrid strategy that uses a separate system for deceleration.

A more practical approach is to use rocket propulsion. Rockets generate propulsive force, also known as thrust, by expelling high-velocity exhaust in a rearward stream. By reversing the direction of the exhaust, rockets can also be used to slow the ship down.

Their main disadvantage is that rockets must carry their own fuel in addition to carrying the passengers, the habitat and other life-sustaining systems. The extra load necessitates even more fuel. In other words, you need fuel to transport your fuel. The result is a costly snowball effect that can cause the total fuel requirement to balloon to absurd proportions.

Rocket propulsion can be divided into three broad categories.

Chemical propulsion uses chemical reactions – typically combustion – to extract energy from the bonds between atoms. All human space missions thus far have used chemical propulsion. The problem with this method is that it accesses only a tiny fraction of the energy contained within the fuel.

Consequently, using chemical propulsion on a spacecraft with a cruise velocity of 19,000 miles per second (30,000 km/s) would require more fuel than all the mass in the observable universe.

Antimatter propulsion is theoretically the most efficient option. When antimatter comes into contact with ordinary matter, the two undergo mutual annihilation and 100% of their combined mass is converted into energy. This makes it possible to achieve the same cruise velocity – one-tenth the speed of light – with fuel accounting for less than a quarter of the ship’s total mass. This is science fiction-level fuel efficiency, which makes antimatter an attractive option for interstellar propulsion.

The downside is that antimatter is extremely unstable and difficult to make. To date, particle physicists have produced less than 20 billionths of a gram of antimatter. Moreover, these particles had lifespans lasting only fractions of a second and a price tag in the hundreds of millions of dollars.

Nuclear fusion offers a more viable alternative to antimatter. This approach harvests energy stored inside the nucleus of an atom using the same process that powers the Sun. With current technology, fusion engines remain aspirational, but they could, in theory, produce 10 million times more energy per kilogram than chemical rockets.

NASA has been working to develop nuclear propulsion. This artist’s impression shows what a nuclear-powered rocket could look like. Image: Public Domain, John Frassanito & Associates/Wikipedia

Still, a fusion-powered ship with a cruise velocity of 19,000 miles per second (30,000 km/s) would require fuel equivalent to 150 times the mass of the ship itself.

A delicate balancing act

These numbers assume that our extraterrestrial visitors have figured out how to efficiently convert the energy released by their reactor – whether nuclear fusion or antimatter – into thrust.

Just as importantly, they must be able to create optimized fuel tank structures that are ultra lightweight yet highly secure. Designing the structure of the ship, from the fuel tanks to the hull, would be one of the biggest engineering challenges of the entire mission.

Interstellar space contains a sparse smattering of hydrogen atoms and microscopic grains of cosmic dust. At 19,000 miles per second (30,000 km/s), dust particles would smash into the ship’s hull with the energy of a .22-caliber bullet. The bombardment of hydrogen atoms would produce a violent cascade of radiation that could erode even the most resilient engineering materials.

Surviving the onslaught would require no less than a flying fortress with complex magnetic shielding. This would increase the total mass of the ship, which further drives up the demand for fuel.

This example is just one of the hundreds of delicate design trade-offs that would plague any interstellar vessel. Each individual design requirement acts as a filter, reducing the number of feasible solutions.

Finding a single system that simultaneously satisfies all the requirements is analogous to shopping for a car online. With each new filter you apply – four-wheel drive, black exterior, less than 10,000 miles on the odometer – the number of available options dwindles.

When design requirements are in tension with one another – for example, requiring a structure that is lightweight but also supremely durable – the number of feasible solutions can drop to zero.

No single law of physics prohibits an interstellar voyage to Earth. But the combined effects of hundreds of extreme, often conflicting engineering requirements may render it physically infeasible.

It’s also possible that alien civilizations have discovered novel technologies that outperform anything currently known to humans. But like the examples discussed here, any such technology will inevitably encounter its own engineering hurdles.

The trillion-dollar question

Ultimately, engineering challenges are just some of the many barriers to interstellar travel. Any prospective alien visitors must also have sufficient cognitive ability, technological maturity, physical resources, collective desire and proximity to Earth.

That said, if the stars were to align and an alien vessel made it to Earth intact, it would trigger a torrent of burning questions: Where are they from? What do they want? What are they made of?

But the question that would go furthest in shedding light on the deeper mysteries of the universe is, “How on Earth did they get here?”

The post Could aliens ever visit Earth? An aerospace scientist unpacks the challenges of interstellar spaceflight. appeared first on Popular Science.

Animals are not the only stinky living things on this planet. The putrid corpse flower blooms with  the stench of rotting flesh, as does the lesser-known (but equally pungent) Bulbophyllum phalaenopsis. Then there is the elegant stinkhorn (Mutinus elegans), a fungus known for its phallic appearance and spores that give off the odor of rotting meat.

Also called the devil’s dipstick, elegant stinkhorns are found across most of eastern North America, particularly from spring to the earliest days of winter. It has also been found in parts of Europe and Asia. They typically prefer temperate climates and looser soils, springing up in gardens, mulch beds, forests, and wood debris during warm and wet weather. They can grow to about four to six inches tall, and a mature mushroom will only last a day or two before subsiding. 

The sticky (and stinky) brown spore substance attracts insects to help the fungi spread. Image: Tina Shaw/USFWS.

All of that stench comes from the dark and slimy coating on the mushroom’s tip called the gleba, and it serves an important purpose. The fungi uses this dark and stinky spore mass to get the flies and other insects buzzing. Once they get a whiff of that rotten flesh smell, they will land on the stinkhorn and get covered in spores. As the bugs fly away, they spread the stinkhorn’s spores far and wide, so that more stinkhorn can pop up elsewhere.  

During the Victorian era, their penis-like appearance was reportedly distressing to some ladies. According to one story, naturalist Charles Darwin’s daughter Henrietta (or Etty), was openly combative towards the elegant stinkhorn. She would roam the woods armed with a spear, following her nose to the offensive mushrooms. Her niece recalled that Etty would find the fungi and “poke his putrid carcass into her basket.” After cleansing the territory, Etty would then secretly burn it to protect “the morals of the maids.”

Henrietta “Etty” Darwin (1843-1927) was the eldest of Charles Darwin’s daughters to reach adulthood. Image: Cambridge University Library. 

If you encounter this bizarre fungus in the wild like Etty Darwin, don’t worry. Beyond offending your nostrils, it is not poisonous or dangerous to your health. But you still probably shouldn’t eat it anyway. 

The post This phallic fungus also smells like rotting flesh appeared first on Popular Science.