Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Eroding the Sphinx
One theory suggests that the Great Sphinx of Giza formed — in part — naturally as a result of erosion, and ancient Egyptians added features to the bedrock formation. To test the plausibility of the theory, researchers made a miniature sphinx, consisting of a clay mound with a single, harder inclusion to represent the Sphinx’s…
“Chaosmosis”
After many years of featuring work from the Gallery of Fluid Motion, I’m excited to announce a new public exhibition of art drawn from the competition: “Chaosmosis: Assigning Rhythm to the Turbulent.” Works in the exhibit come from both scientists and artists; each piece makes visible the fluid motions that surround us. The exhibit is…
Viscoelasticity and Bubbles
Bursting bubbles enhance our drinks, seed our clouds, and affect our health. Because these bubbles are so small, they’re easily affected by changes at the interface, like surfactants, Marangoni effects, or, as a recent study shows, viscoelasticity. In clean water, a bubble’s burst generates a rebounding jet that shoots off one or more daughter droplets,…
Red Sprites
Sprites, or red sprites, are high-altitude electrical discharges in the atmosphere. Although sometimes called upper-atmospheric lightning, sprites are a cold plasma phenomenon. They often occur in clusters, as in this photo by Angel An, which won in the Skyscapes category of the 2023 Astronomy Photographer of the Year competition. Sprites, which last only a millisecond…
Bravo!
Applauding is a familiar activity, but, as you stand for an encore in the concert hall, do you think about how you hold your hands and how that affects your clap? That question prompted two scientists to embark on an acoustical exploration of clapping. By testing 11 different ways to hold their hands during clapping,…
Snake Tracks
Moving across sand is quite challenging for bipedal creatures like us, but other animals have their ways. Photographer Paul Lennart Schmid caught this snake on the move, with impressions of its passage still in the sand. X-ray observations of snakes moving in sand show that they swim through the granular medium. Snakes are quite efficient…
Spreading Spores
Mushrooms are the fruiting bodies of much bigger, largely underground fungi. Being fruit, mushrooms have the job of spreading spores so that the fungus can reproduce. Some mushrooms rely on the wind; others create their own wind. Still others use vortex rings to carry their spores higher. Who knew such fascinating and beautiful physics lies…
Dancing Peanuts
Bartenders in Argentina sometimes entertain patrons by tossing a few peanuts into their beer. Initially, the peanuts sink, but after a few seconds they rise, wreathed in bubbles. Once on the surface, they roll, causing the bubbles to pop, and the peanut sinks once again. The cycle repeats, sometimes for as long as a couple…
Frozen Ripples
Normally, freezing is a slow enough process that transient phenomena like ripples get smoothed out. But with the right conditions, even ripples can get frozen in time. This picture shows a backyard bird bath after a frigid winter storm passed overnight. For much of that time, the wind was active enough to keep the bath’s…
Why Sea Foams
Seawater froths and foams in ways that freshwater rarely does. A new study pinpoints the ocean’s electrolytes as the reason bubbles resist merging there. By studying the final moments before bubbles coalesce in both pure and salt water, researchers found that dissolved salts slow down the drainage of the thin film of liquid between two…