Breaking a jet of liquid into droplets lies at the heart of many industrial processes: spray painting, fuel injection, and asthma inhalers, to name a few. Here, researchers are looking at a different method of breaking up a liquid jet: shooting a shock wave along its length. The poster shows five different snapshots of the jet’s response. There are, variously, mists of fine droplets, wavy distortions of the jet, sheets, ligaments, and droplets of many sizes. (Image credit: S. Rao et al.)
On 10 August 2025, the slopes of Alaska’s Tracy Arm Fjord gave way, sliding into the water. The resulting tsunami was the second-largest ever recorded, with a 481-meter runup after a 100-meter initial wave that moved at more than 70 meters per second. The fjord was fortunately empty at the time, though it is regularly visited by cruise ships. After the landslide, a seiche ricocheted through the fjord for 36 hours.
With no earthquake to trigger the tsunami, researchers had to piece together the accident through forensics. Their study concluded that the glacier’s retreat had left unstable slopes exposed, likening it to a child’s closet overstuffed with hastily gathered toys. The moment the door is no longer held closed, everything comes crashing out.
Ultimately, the landslide-induced tsunami is, therefore, a result of climate change. That result is disconcerting, given the increasing frequency of cruise ships visiting glacial fjords. Unlike earthquake-induced tsunamis, landslide-induced ones like the Tracy Arm event don’t come with a seismic warning. With rapid climate change and frequent tourism, risk management is critical. (Image credit: C. Read/USGS; research credit: D. Shugar et al.; via Eos)
Insect flight is vastly different than the aerodynamics engineers learn around aircraft. That’s particularly apparent looking at these tiny moths taking off and flying in slow motion. Almost every feature seems, at first glance, aerodynamically wasteful. Hairy, scaly surfaces instead of smooth ones? Relatively small wings for their body size? Moths break our engineering intuition.
For moths, flight is an inherently unsteady process. Every stroke of its wings cups and flings fluid away in an effort to generate enough lift to stay aloft. Notice how the wings flex with each stroke. Part of the moth’s efficiency comes from that flexibility, even though keeping wings relatively stiff is the norm for engineering larger fixed-wing craft. And those hairy surfaces? Not only can they help camouflage insects; they keep them hydrophobic so that water bounces off them. (Video and image credit: Ant Lab/A. Smith)
Coffee is a key ingredient in the scientific process for many researchers, so it’s no wonder that researchers often develop an interest in the drink’s physics and chemistry. In a new study, a research team devised an objective method to test both a coffee’s strength and its roast color.
The researchers used a potentiostat to test how an electric current interacted with the brewed coffee and showed how the measurements related to the coffee’s flavor. The method was even robust enough that they could identify which coffee sample came from a batch of beans that had failed a roaster’s quality controls.
While you’re unlikely to use such a method at home, it could be helpful in coffee shops, where baristas try to pin down the variables to produce the same flavor in every cup. (Image credit: M. Kenneally; research credit: R. Bumbaugh et al.; via Ars Technica)
NASA’s Ingenuity helicopter was the first aircraft humanity has flown on another planet, and engineers are looking to make the next generation of Martian helicopters bigger and more capable. That’s challenging in Mars‘ thin atmosphere, which is only 1% as dense as Earth’s. To get adequate lift, the rotors need to spin faster there.
During Ingenuity’s mission, the team intentionally designed the craft to keep the rotor tips below supersonic speeds. But for the next mission–SkyFall–they’re looking to push the rotorcraft further. In recent tests in a Mars simulator chamber, they successfully spun the new rotors to tip speeds as high as Mach 1.08, significantly increasing the loads SkyFall could carry. (Image and video credit: NASA/JPL-Caltech; via Ars Technica)
Artist Thomas Blanchard likes to create wild visuals from a mixture of mundane ingredients like ink, soap, oils, and ferrofluids. In this latest video, he’s mixed chemical reactions and physical phenomena into something reminiscent of a god’s eye staring across time and space, creation and destruction. (Video and image credit: T. Blanchard)
In the past few decades, our knowledge of exoplanets has exploded, but we’re still relatively limited in what we can learn about these worlds. That’s due, in large part, to the indirect way we observe them. Most exoplanets are found when we see them transit, passing between Earth and their star. During a transit, the planet blocks a portion of the light we would otherwise detect from the star, letting us know that something’s there. We’re often able to measure the spectra of light passing through the exoplanet’s atmosphere, giving us a glimpse of chemical signatures.
Today’s study looks at exoplanet WASP-94A b, a gas giant tidally-locked so that only one side ever faces its star. In its transit, researchers could clearly measure different spectra from the morning and evening sides of the planet. The asymmetry seems to indicate that the exoplanet develops thick clouds on the nightside, which then dissipate during the daytime. (Image credit: H. Robbins/JHU; research credit: S. Mukherjee et al.; via Nature)
Ocean sprays, coughs, and sneezes are just a few of the ways that droplets full of bacteria and salt can get aloft on a breeze. How do these bacteria stay viable even as their droplet evaporates? That’s the question behind this video’s research.
When a bacteria-laden droplet or a salt-laden droplet dries, the evaporating droplet’s contact area shrinks, leaving behind only a concentrated lump of bacteria or salt. But when droplets contain both salt and bacteria, the drying droplet’s contact line gets pinned, leaving a larger area stain. The bacteria’s presence seems to promote crystallization of the salt, which–in turn–traps water in isolated spaces, perhaps helping the bacteria stay viable longer. (Video and image credit: R. Ran et al.)
We’re terribly spoiled these days when it comes to footage of lava and volcanic eruptions. Back when I started FYFD, I could find very few decent photos of lava flows to illustrate posts. And now, thanks to drone cameras, we have a glut of absolutely gorgeous footage of flowing lava. This particular example comes from photographer Jan Erik Waider, who specializes in the ice, fire, and flows of northern landscapes.
Waider’s lens offers us a detailed, almost abstract view of these rivers of lava. I especially enjoy his shots looking directly down on lava. Watching the cooled rock rafting along on the lava is like seeing a fiery version of sea ice floes. (Video and image credit: J. Waider; via Laughing Squid)
Sprinklers have long been the go-to fire protection for commercial properties and some residences. Dousing a fire in water not only puts out the flames but cools the surroundings and helps prevent reignition. But it requires complicated infrastructure and can damage buildings and their contents. Back in 2015, students were experimenting with an alternative fire extinguisher that used sound below the range of human hearing; now a company is pitching a version of that technology for replacing sprinklers.
As described by Ars Technica, this infrasound system can detect and put out a small kitchen fire in under a minute. But fire fighting experts warn that there’s a big difference between a fire small enough for a fire extinguisher to handle and the kinds of fires sprinklers put out. With lives at stake, the burden of proof is significant for Sonic Fire Tech and any other company that wants to get their infrasound “sprinkler” system cleared for use in buildings. (Image credit: I. Azevedo; via Ars Technica)
