- Profile
Salt and Dunes
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…
How Corals Stir
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…
The Subtleties of Pipe Flow
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…
Screening for Sleep Apnea
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…
Microplastics in the Water Column
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…
“Supercell”
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…
Ice Giant or Magma Ocean World?
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…
Giant Water Balloon to the Face
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…
Inside an Espresso Bed
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,…
Canyon Swirls
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…