FYFD

Our planet is constantly carved by the flow of wind, water, and ice. These images, all shortlisted by the International Aerial Photographer of the Year competition, highlight those forces. From meandering rivers and spreading deltas to cracked valleys and windswept dunes, flow is all around us. (Image credit: Various Artists/IAPOTY, see images for details; via […]

Realistically modeling rainfall remains an extremely difficult problem. To be practical, results have to be on the scale of kilometers; no one is looking to find out whether rain will fall from one specific cloud over their head. But making that prediction depends on physics that happens at the microscale, where droplets tens of microns […]

Many of us have a mental image of strings vibrating like a swinging jump rope, but that’s not quite what you actually see. Instead, plucked strings often look strangely triangular, as Henry explains in this Minute Physics video. This more complicated shape comes from the way the string’s tension responds to the applied force of […]

Mars was once a warmer, wetter place, swathed in a thick and protective atmosphere. Unlike Earth, Mars lacks a strong global magnetic field, which allows the solar wind to strip its atmosphere, but the exact mechanisms of that process have been unclear. But a new study has caught the process in action. By combining simultaneous […]

Footage of a massive iceberg flipping in Greenland has gone viral. The feat took place off the coast of Ilulissat and was caught on a nearby livestream camera. Icebergs shift like this because they melt unevenly, with submerged areas melting faster. As the underwater shape of the iceberg changes, the buoyant forces shift relative to […]

It’s no secret that I’m a fan of fountain pens. They’re just one way I like to have little celebrations of fluid physics in my everyday life. That said, I don’t typically use anything with a monster flex nib like what you see here. This is extra. But it’s also an incredibly cool glimpse of […]

Nature is full of helical fibers, including in plants and bird feathers. In this study, researchers explore how these soft springs react to droplets. When the pitch of the spring (roughly speaking, the spacing between coils) is small, droplets can flow down in a plug (not shown). But as the pitch increases, droplets can take […]

We’ve seen a few different kinds of levitation here over the years, including via acoustic waves, aerodynamics, and Leidenfrost effect. Here, Steve Mould describes something a bit different: a levitation squeeze film driven by ultrasonic transducers. Like a vibrating droplet, the thing keeping surfaces apart here is a thin, lubricating layer of air. The vibration […]

Like fighter pilots of old, male dragonflies engage in aerial combat where each tries to outmaneuver the other to keep a sight on their rival’s tail. A recent study observed this combat in the field and uncovered some surprising similarities to dogfighting. Like pilots, dragonflies used spiraling turns and other high-g moves to gain an […]

In raindrops, ink-jet printing, and spray painting, droplets get broken apart by the air flowing around them. Here, researchers investigate how a jet of fluid can push a droplet from its perch, or–with enough momentum–shatter the droplet. There are some lovely flow visualizations here; it’s especially cool to see the starting vortex ring of the […]

Photographer Barbara Brown captured these striking aerial views in Namibia. Coastal dunes and saltworks feature in the photos from Walvis Bay, where wind, waves, evaporation, and humankind have shaped the landscape. The colorful and dendritic dune images come from Sossusvlei, where the ephemeral Tsauchab River ends in the Namib Desert. Recent flooding left its mark […]

Reef-building coral polyps constantly stir the water around them with dense carpets of microscopic hair-like cilia. The beating of the cilia helps polyps feed while also pushing away sediment and debris. Their stirring increases nutrient and gas exchange with seawater, too. A new study combines experimental measurements with a simple mathematical model to recreate the […]

If you put a thumb over your hose’s outlet, you get a faster jet, but how does that affect the flow rate? That’s the question Grady starts from in this Practical Engineering video exploring pipe flow physics. From continuity and control volumes to practical losses, he touches on both the theory and practice behind this […]

Snoring and sleep apnea–a condition where aeroelastic flutter obstructs the airway and stops breathing during sleep–often go hand-in-hand. But diagnosing sleep apnea involves an expensive and time-consuming screening in which the patient has to sleep while monitored by various sensors. To make the process easier, researchers are developing a screening method based only on audio [&#823…

Of the more than 9 billion metric tons of plastic that’s been produced, a mere 9% has been recycled. About 12% has been incinerated, and the remainder is just out there–in our homes, our landfills, and, unfortunately, in our oceans. Exactly where all the plastic is continues to be an active question of research. Plastic’s […]

A supercell thunderstorm in New Mexico appears almost otherworldly in this photo from Dennis Hualong Zhang. Glowing from within and stacked like a layer cake, the storm menaces the nearby road and fields. Lightning in the distances completes the composition. Images like this are a reminder that our atmosphere–despite frequently seeming calm and ordinary–harbors incredible […]

Uranus and Neptune–known as our system’s ice giants–are our least explored planets. Both have received exactly one flyby, from the Voyager 2 spacecraft. The data from those flybys remain our primary source of knowledge about each planet. The traditional model for each planet’s interior (dating back to before the flybys) consists of three layers: a […]

It’s the summertime, so Gav and Dan of the Slow Mo Guys are back to experimenting with giant water balloons. In this video, they send several careening down a slope into Dan’s face. Watching the balloons descend and pop is (unsurprisingly) my favorite part. It’s neat to see how the elasticity of the balloon acts […]

When pulling a shot of espresso, there are complicated physics at play. The ground coffee is tamped into a puck-like bed of grains, through which high-temperature, high-pressure water is forced. Here, researchers used X-ray tomography to visualize how and when water moves through the bed, which affects how flavors extract. In a finely ground bed, […]

For much of the year, Cañon Fiord in the Canadian Arctic lies under ice and snow, but in the summer melt season, colors peek out. Here sea ice and sediment swirl in the fjord in eddies that are kilometers wide. The sediment is largely glacial flour–rock that’s been ground into dust by glaciers. It provides […]