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Yesterday — 27 December 2024Main stream

Magnetic shape-shifting surface can move stuff without grasping it 

27 December 2024 at 05:45

When you want to move an object from one place to another, you usually grab it with your hands or a robotic arm. But what if you want to move something you cannot touch without damaging or disrupting it, like a droplet of liquid? A solution proposed by a team of scientists at the North Carolina State University is a metamaterial that can change shape in response to magnetic fields.

This material had to be easily deformable to change shape, yet at the same time stiff enough to bear loads. “That seemed contradictory—how do you make something that is stiff and deformable at once?” says Jie Yin, a mechanical metamaterials researcher at NC State. His team did it with ferromagnetic elastomers, kirigami cuts, balloons, and magnets.

Refreshable Braille display

“There is not much research on using magnets to manipulate non-magnetic objects. It is very, very hard,” says Yinding Chi, another NC State researcher and lead author of the study. The idea Chi and his colleagues came up with could be compared to a refreshable Braille display. They imagined a surface dotted with domes that could rise, turn, or depress on demand, allowing it to dynamically form relief-like images or move in a pattern similar to waves in the ocean. Objects would then move on these surfaces like they were carried by waves. “This way, you can move various objects without using grippers,” Yin says.

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Before yesterdayMain stream

Green sea turtle gets relief from “bubble butt” syndrome thanks to 3D printing

21 December 2024 at 04:25

Charlotte, a green sea turtle, was hit by a boat back in 2008. This left it with an affliction colloquially referred to as the “bubble butt,” a kind of floating syndrome that makes it impossible for a turtle to dive. Most sea turtles suffering from issues like this simply die at sea, since the condition leaves them stranded at the surface where they can’t forage, sleep, and avoid predators like sharks. But fate had other plans for Charlotte.

Charlotte didn’t end up as a shark’s lunch and didn’t starve to death floating helplessly in the ocean. Instead, it got rescued shortly after the boat accident and eventually found a home at Mystic Aquarium in Stonington, Connecticut, where it received professional care. That was the first time Charlotte got lucky. The second time came when a collaboration formed: Adia, a company specializing in 3D-printing solutions; Formlabs, one of the world’s leading manufacturers of 3D printers; and New Balance Athletic, a sportswear giant based in Boston. This team chose Charlotte as a technology showcase, which basically turned the turtle into an Oscar Pistorius of the sea—just without the criminal conviction.

Weights and diet

Sea turtles are marine reptiles, which means they don’t have gills like fish—they need air to breathe. The lungs also play a key role in their buoyancy regulation system, which allows them to rest for extended periods of time at the sea floor or float at a precisely chosen depth. A sea turtle can precisely choose the depth at which it achieves neutral buoyancy by inhaling the exactly right volume of air.

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© Laura Shubel

Generating power with a thin, flexible thermoelectric film

12 December 2024 at 11:00

The No. 1 nuisance with smartphones and smartwatches is that we need to charge them every day. As warm-blooded creatures, however, we generate heat all the time, and that heat can be converted into electricity for some of the electronic gadgetry we carry.

Flexible thermoelectric devices, or F-TEDs, can convert thermal energy into electric power. The problem is that F-TEDs weren’t actually flexible enough to comfortably wear or efficient enough to power even a smartwatch. They were also very expensive to make.

But now, a team of Australian researchers thinks they finally achieved a breakthrough that might take F-TEDs off the ground.

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New drone has legs for landing gear, enabling efficient launches

Most drones on the market are rotary-wing quadcopters, which can conveniently land and take off almost anywhere. The problem is they are less energy-efficient than fixed-wing aircraft, which can fly greater distances and stay airborne for longer but need a runway, a dedicated launcher, or at least a good old-fashioned throw to get to the skies.

To get past this limit, a team of Swiss researchers at the École Polytechnique Fédérale de Lausanne built a fixed-wing flying robot called RAVEN (Robotic Avian-inspired Vehicle for multiple ENvironments) with a peculiar bio-inspired landing gear: a pair of robotic bird-like legs. “The RAVEN robot can walk, hop over obstacles, and do a jumping takeoff like real birds,” says Won Dong Shin, an engineer leading the project.

Smart investments

The key challenge in attaching legs to drones was that they significantly increased mass and complexity. State-of-the-art robotic legs were designed for robots walking on the ground and were too bulky and heavy to even think about using on a flying machine. So, Shin’s team started their work by taking a closer look at what the leg mass budget looked like in various species of birds.

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© EPFL/Alain Herzog

People will share misinformation that sparks “moral outrage”

Rob Bauer, the chair of a NATO military committee, reportedly said, “It is more competent not to wait, but to hit launchers in Russia in case Russia attacks us. We must strike first.” These comments, supposedly made in 2024, were later interpreted as suggesting NATO should attempt a preemptive strike against Russia, an idea that lots of people found outrageously dangerous.

But lots of people also missed a thing about the quote: Bauer has never said it. It was made up. Despite that, the purported statement got nearly 250,000 views on X and was mindlessly spread further by the likes of Alex Jones.

Why do stories like this get so many views and shares? “The vast majority of misinformation studies assume people want to be accurate, but certain things distract them,” says William J. Brady, a researcher at Northwestern University. “Maybe it’s the social media environment. Maybe they’re not understanding the news, or the sources are confusing them. But what we found is that when content evokes outrage, people are consistently sharing it without even clicking into the article.” Brady co-authored a study on how misinformation exploits outrage to spread online. When we get outraged, the study suggests, we simply care way less if what’s got us outraged is even real.

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© Ricardo Mendoza Garbayo

Teaching a drone to fly without a vertical rudder

27 November 2024 at 10:08

Most airplanes in the world have vertical tails or rudders to prevent Dutch roll instabilities, a combination of yawing and sideways motions with rolling that looks a bit like the movements of a skater. Unfortunately, a vertical tail adds weight and generates drag, which reduces fuel efficiency in passenger airliners. It also increases the radar signature, which is something you want to keep as low as possible in a military aircraft.

In the B-2 stealth bomber, one of the very few rudderless airplanes, Dutch roll instabilities are dealt with using drag flaps positioned at the tips of its wings, which can split and open to make one wing generate more drag than the other and thus laterally stabilize the machine. “But it is not really an efficient way to solve this problem,” says David Lentink, an aerospace engineer and a biologist at the University of Groningen, Netherlands. “The efficient way is solving it by generating lift instead of drag. This is something birds do.”

Lentink led the study aimed at better understanding birds’ rudderless flight mechanics.

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© HamidEbrahimi

Tweaking non-neural brain cells can cause memories to fade

23 November 2024 at 04:00

“If we go back to the early 1900s, this is when the idea was first proposed that memories are physically stored in some location within the brain,” says Michael R. Williamson, a researcher at the Baylor College of Medicine in Houston. For a long time, neuroscientists thought that the storage of memory in the brain was the job of engrams, ensembles of neurons that activate during a learning event. But it turned out this wasn’t the whole picture.

Williamson’s research investigated the role astrocytes, non-neuron brain cells, play in the read-and-write operations that go on in our heads. “Over the last 20 years the role of astrocytes has been understood better. We’ve learned that they can activate neurons. The addition we have made to that is showing that there are subsets of astrocytes that are active and involved in storing specific memories,” Williamson says in describing a new study his lab has published.

One consequence of this finding: Astrocytes could be artificially manipulated to suppress or enhance a specific memory, leaving all other memories intact.

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© Ed Reschke

Our Universe is not fine-tuned for life, but it’s still kind of OK

22 November 2024 at 10:30

Physicists including Robert H. Dickle and Fred Hoyle have argued that we are living in a universe that is perfectly fine-tuned for life. Following the anthropic principle, they claimed that the only reason fundamental physical constants have the values we measure is because we wouldn’t exist if those values were any different. There would simply have been no one to measure them.

But now a team of British and Swiss astrophysicists have put that idea to test. “The short answer is no, we are not in the most likely of the universes,” said Daniele Sorini, an astrophysicist at Durham University. “And we are not in the most life-friendly universe, either.” Sorini led a study aimed at establishing how different amounts of the dark energy present in a universe would affect its ability to produce stars. Stars, he assumed, are a necessary condition for intelligent life to appear.

But worry not. While our Universe may not be the best for life, the team says it’s still pretty OK-ish.

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© Sololos

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