Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Morphing Particle Rafts
A layer of tiny glass beads sitting atop a pool of castor oil becomes a morphing surface in this video. Applying an electric field creates enough electrostatic force to draw the interface upward against the power of both gravity and surface tension. Moving the electric field — either by shifting the electrode or simply moving…
Turbulence in Flight
Eagles and other birds spend much of their lives in the turbulence of our atmospheric boundary layer. Some of their interactions with turbulence — like using topographical effects to aid their flight — are well-known, but much remains uncertain. One team of researchers looked at a tagged golden eagle’s flight data, compared with known wind…
Portraits of Flight
During lockdown, photographer Doris Mitsch turned her eyes to the sky and began capturing these mesmerizing composite images of animals in flight. Vultures, crows, starlings, gulls, and bats all feature in her series. Some images, like “Lockdown Vulture (Signature)”, feature a single bird’s movement over a minute. Others show entire flocks over extended periods. I…
Mushy Layers
In many geophysical and metallurgical processes, there is a stage with a porous layer of liquid-infused solid known as a mushy layer. Such layers form in sea ice, in cooling metals, and even in the depths of our mantle. Within the mushy layer, temperature, density, and concentration can vary dramatically from one location to another.…
Splashing on Spheres
The splash of a droplet is a surprisingly complex phenomenon, depending not only on the droplet’s characteristics but also the surrounding air pressure, the roughness and temperature of the impact surface, and the surface’s curvature. In this study, researchers investigated the effects of surface curvature on splashing, finding that it’s harder for a drop to…
Conserving the Hill House
In 1904, Scottish architect Charles Rennie Mackintosh created the Hill House, a masterpiece of modern design decades ahead of its time. Unfortunately, the Portland cement used for the house’s exterior has not held up well to a century of Scottish rains. As water saturated the cement, it began to dissolve and crumble. So to save…
Wild Patterns in Ionic Liquids
Ionic liquids are essentially salts in a liquid form. In these images, a mixture of water and ionic liquid separates when heated. This phase separation causes the initial mixture to break into two regions: one low in ionic liquid and one rich in ionic liquid. Because the surface tensions of these two phases are different…
#IfThenSheCan Exhibit at the Smithsonian
I’m not normally one to talk about myself here on FYFD. This site was made to keep the focus on the science, but I’m making an exception today to share a very special exhibit that I’m a part of: the #IfThenSheCan Exhibit, which opens today at the Smithsonian in Washington, DC as part of their…
“Delusion”
Soap films are ephemeral and ever-changing. The shifting concentration of surfactants along the surface of the film, combined with thermally-driven convection, keeps the fluid in motion. The shifting colors reflect subtle changes in the soap film’s thickness. Over time, gravity drains fluid from the top of the film, thinning it to the point that it…
Vortex Arms
A fixed cylinder will shed alternating vortices in its wake, but one allowed to oscillate forward and backward in the flow instead sheds simultaneous vortices. The shape of the wake still depends on the flow’s velocity. At low flow speeds, the two vortices are the same size when they shed. At higher velocities, the two…