Watering your lawn in the summer can be both pragmatic and fun with so-called "silly sprinklers," designed to create amusing loops and spirals of water jets. And there's some fascinating physics at work to boot. Researchers at New York University's Courant Institute conducted a series of experiments with different silly sprinkler designs to find the answer to a longstanding problem in fluid dynamics, according to a new paper published in the Proceedings of the National Academy of Sciences.

As previously reported, the reverse sprinkler problem is associated with physicist Richard Feynman because he popularized the concept, but it actually dates back to a chapter in Ernst Mach’s 1883 textbook The Science of Mechanics (Die Mechanik in Ihrer Entwicklung Historisch-Kritisch Dargerstellt). Mach’s thought experiment languished in relative obscurity until a group of Princeton University physicists began debating the issue in the 1940s.

Feynman was a graduate student there at the time and threw himself into the debate with gusto, even devising an experiment in the cyclotron laboratory to test his hypothesis. One might intuit that a reverse sprinkler would work just like a regular sprinkler, merely played backward, so to speak. But the physics turns out to be more complicated. “The answer is perfectly clear at first sight,” Feynman wrote in Surely You’re Joking, Mr. Feynman (1985). “The trouble was, some guy would think it was perfectly clear [that the rotation would be] one way, and another guy would think it was perfectly clear the other way.”

Read full article

Comments

When Warner Bros. showed new footage of its forthcoming satirical black comedy, Digger, at Cinemacon in April, industry insiders considered it a highlight of the event. The general public hasn't seen anything other than a title announcement and a teaser in May that largely provided a retrospective of star Tom Cruise's career, with just 30 seconds of footage from Digger tacked on at the end. But now we have the official trailer, and it certainly lives up to that earlier enthusiastic word of mouth. We're getting powerful Dr. Strangelove vibes, updated for our 21st-century times.

Digger is four-time Oscar-winning director Alejandro G. Iñárritu's (Birdman) first English-language film since 2015's The Revenant. The official logline is short and sweet: "The most powerful man in the world races to prove he's humanity's savior before the disaster he unleashed destroys everything." That disaster appears to be ecological in nature and involves a rapidly melting iceberg, as well as some nuclear waste.

Cruise is often at his best when he takes big creative swings and plays against type—the rage-fueled motivational speaker in Magnolia, for instance, or the over-the-top movie mogul in Tropic Thunder. He's almost unrecognizable in this new trailer as eccentric billionaire oil baron Digger Rockwell—wispy hair, potbelly, and all.

Read full article

Comments

Back in 2024, we reported on the discovery of the Quest shipwreck, the polar exploration vessel that served Arctic explorer Sir Ernest Shackleton on his last voyage. Shackleton died before reaching their destination, and the ship sank in 1962. The Royal Canadian Geographic Society (RCGS) has now released the first images of the wreck more than 60 years after it sank, published in Canadian Geographic magazine.

Shackleton, of course, is most famous for his ill-fated voyage on the Endurance, which became trapped in sea ice in 1914 and sank. Shackleton and his crew defied the odds and survived. (The Endurance shipwreck was finally found in 2022.) By the time Shackleton returned to England, the country was embroiled in World War I, and many of his men enlisted. Shackleton was considered too old for active service. He was also deeply in debt from the Endurance expedition, earning a living on the lecture circuit. But he still dreamed of making another expedition to the Arctic Ocean north of Alaska to explore the Beaufort Sea. He got funding from an old school chum, John Quillier Rowett.

Shackleton purchased a wooden Norwegian whaler, Foca I, which his wife Emily renamed Quest. When the Canadian government withdrew its support, the mission shifted back to the Antarctic, and the Quest received an extensive retrofit. The improvements included a new deckhouse, a heated crow’s nest, a wireless set, and an odograph for tracing and charting the route automatically, as well as a Lucas deep-sea sounding machine, a large and pricey collection of cameras and photographic equipment, and even a small airplane.

Read full article

Comments

We haven't seen much footage to date for Denis Villeneuve’s Dune: Part Three, other than the broody and haunting extended teaser Warner Bros. dropped in March. But now we've got a shiny new trailer jam-packed with tantalizing hints of what to expect, and plenty of Easter eggs to delight avid book fans.

(Spoilers for first two films in the franchise below.)

As previously reported, in 2021’s Dune, we first met Frank Herbert’s iconic anti-hero, Paul Atreides (Timothée Chalamet). That film culminated in the brutal defeat of House Atreides by rival House Harkonnen, with Paul and his mother, Lady Jessica (Rebecca Ferguson), fleeing to the desert and taking refuge among the Fremen. Among them is Chani (Zendaya), whom Paul has been seeing in visions all along.

Read full article

Comments

TikTok's For You Page (FYP) is the default home screen for users of the video-sharing platform. It's a personalized, algorithmically driven content feed, but the approach differs from other social media in that TikTok's algorithm relies heavily on implicit signals—such as how long users watch particular videos—as well as explicit signals such as likes or follows. And generally, that algorithm does remarkably well at predicting which videos will interest particular users.

But some users have voiced concerns that TikTok's almighty algorithm doesn't seem to incorporate negative feedback very well. Even when they don't watch a suggested video or click the "not interested" feature, they keep seeing those videos on their FYP. Northeastern University computer scientists put those suspicions to the test. According to their recent paper, the engagement signals do have an effect, but only temporarily. Then the algorithm gradually relapses unless a user consistently gives the same feedback over and over again.

The research group specializes in "algorithm audits," co-author Piotr Sapiezynski told Ars, to better understand online platforms: "how they work, how they fail, when they fail, how they harm individuals and societies." In this case, he and his co-authors wanted to take a closer look at user agency after hearing multiple anecdotal reports from TikTok users that their negative feedback—responding to prompts by indicating they aren't interested or want to see less of a certain kind of video—doesn't seem to remove those posts from their FYP. "On the other hand, it's unclear why the platforms would offer it, if it doesn't work," said Sapiezynski.

Read full article

Comments

Male dragonflies are known to engage in mid-air "dogfights" to defend their breeding territory, using different maneuvers than those they employ when hunting prey. A new paper published in the Journal of the Royal Society Interface concluded that relatively simple rules drive that behavior, namely that male dragonflies are trying to maintain a tactical position. This mirrors the tactics of human fighter pilots. The research could lead to the development of smarter drones capable of navigating with simple, vision-based guidance rather than complex computation.

Classic pursuits involving prey or mating rituals are asymmetric: there is a chaser and an evader, with each role requiring different maneuvers. In the case of male-on-male interactions, however, it is more of a mutual pursuit, per the authors, who thought that studying flight trajectories of insects or raptors could yield useful insights into the guidance laws that underlie the behavior. They chose the Trithemis Aurora species of dragonfly for study because the males are "fiercely territorial," and there are usually multiple males around a given pond, intent on defending their chosen perches. The dragonflies are also crimson-colored, making them easier to track.

Much of the prior research on dragonfly interactions relied on visual observations or single-camera recordings. For this study, the authors set up a portable stereovideographic rig with two shutter-synchronized cameras to record dragonfly interactions in both color and monochrome, and then reconstructed 102 paired male-on-male flight trajectories to capture the 3D kinematics. They also reconstructed nine trajectories for dragonflies intercepting prey for comparative purposes. This enabled the authors to develop a model for the rules governing the flight behavior.

Read full article

Comments

Pour one out for Supergirl, the latest installment in the DCU's Gods and Monsters chapter, which has been beset by online troll attacks, mixed reviews, and a very disappointing opening weekend box office—not the outcome Warner Bros. was hoping for with this follow-up to last year's Superman. It's actually a pretty good movie, as such films go, but it's not a great movie. And in today's over-saturated superhero market, that's just not sufficient to get people out of their homes and into theaters, rather than waiting for the film to come to streaming platforms.

(Some spoilers below but no major reveals.)

The studio tapped Ana Nogueira to write the script, a holdover from the former DCEU plans for a standalone Supergirl film. (The character appeared in the finale of 2022's The Flash, played by Sasha Calle.) The project was reimagined when James Gunn and Peter Safran took over and launched the "soft reboot" DCU. Director Craig Gillespie (Lars and the Real Girl, I Tonya) signed on to direct.

Read full article

Comments

Preparing skeletal specimens for display in museums or for forensic studies requires the bones to be thoroughly cleaned to remove any remaining flesh or soft tissue. However, the need for thorough cleaning must be balanced against the risk of damaging the actual bones. According to a new paper published in the journal PLoS One, the larvae of so-called "superworms" (Zophobas morio)—a common pet food—offer a practical alternative.

There are existing methods for cleaning skeletal remains, such as burial, digestive enzymes, or chemical treatments. But most have drawbacks, including damaging bones, taking a long time to process, having expensive operational costs, or the use of environmentally hazardous substances. Using dermestid beetles has become the preferred method for skeletal cleaning since they can efficiently remove soft tissue without damaging the bone. The downside is that without strict containment practices, the beetles can escape and lay eggs that hatch, leading to infestations that threaten museum collections.

Fatemah Rastekar of Ferdowsi University of Mashhad in Iran and co-authors thought superworms might bring the same benefits as the beetles without the risk of infestation. For one thing, beetle colonies span all life stages and hence require complex containment; superworm cleaning only requires the larval stage, which lasts 10–12 weeks compared to just five to seven weeks for the beetles. And the larvae don't pupate in crowded conditions, so it's easier to manage the colonies while reducing the risk of escape. But could superworms match the cleaning efficiency of their rival beetles?

Read full article

Comments

We're counting down the days until the release of Christopher Nolan's The Odyssey, and Universal Pictures has released one last trailer to keep anticipation high.

Most of us read some version of The Odyssey in high school, so we’re familiar with the story: Odysseus, legendary Greek king of Ithaca, begins the long journey home after 10 years of fighting in the Trojan War. But the journey doesn't go smoothly, as Odysseus and his men encounter the cyclops Polyphemus, the Sirens, and an enchantress named Circe, among other obstacles. Meanwhile, Penelope, his long-suffering wife, wards off hundreds of suitors eager to usurp Odysseus’ position.

Matt Damon stars as the wandering Ithacan king. The cast also includes Anne Hathaway as Penelope; Tom Holland as Odysseus’ son, Telemachus; Robert Pattinson as Antinous, one of Penelope’s many suitors; Jon Bernthal as the Spartan king, Menelaus; Benny Safdie as the Achaean commander during the Trojan War, Agamemnon; John Leguizamo as Odysseus’ faithful servant, Eumaeus; Himesh Patel as his second-in-command, Eurylochus; Will Yun Lee and Jimmy Gonzales as crew members; and Mia Goth as Penelope’s maid Melantho. We also have Zendaya as Athena, Charlize Theron as Circe, and Lupita Nyong’o in a dual role: both Helen of Troy and Helen's sister, Clytemnestra.

Read full article

Comments

It’s a regrettable reality that there is never enough time to cover all the interesting scientific stories we come across. So every month, we highlight a handful of the best stories that nearly slipped through the cracks.  June’s list includes insight into the science of soccer's scissors feint; the physics of poo's distinctive coiled shape; a boron buckyball; and the latest breakthrough in the ongoing Vesuvius challenge to decipher the Herculaneum scrolls.

The science of soccer's scissors feint

Credit: Screenshot/YouTube/Howcast

With the FIFA World Cup in full swing, even scientists' thoughts are turning to soccer (or football for everyone else in the world). For instance, one common and highly effective dribbling maneuver is the "scissors feint," in which a player uses the outside of their feet to fake going one way and then cutting to the other. Japanese scientists studied university and junior high school soccer players of varying skill levels to study dribbling dynamics, focusing on the scissors feint. The movements were captured with high-speed cameras.

Read full article

Comments