Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Swimming With Cilia
Like most microswimmers, these Synura uvella algae use cilia to swim. Cilia are tiny, hair-like appendages that flap to produce thrust. Even under a microscope, the cilia are hard to see because they are so thin and move quickly in and out of the microscope’s narrow focus. A cilia’s stroke is always asymmetric — no…
Peering Inside Viscous Fingering
Viscous fingers form when a low-viscosity fluid is pumped into a narrow, viscous-fluid-filled gap. The branching pattern that forms depends on the ratio of the two viscosities, among other factors. To better understand what goes on inside these fingers, researchers carefully alternated injecting dyed and undyed fluid. This creates a pattern of concentric rings that…
More Gigantic Jets
It’s wild that we’re still discovering new weather phenomena, but the gigantic jets seen here were only identified in 2002. This uncommon type of lightning shoots up from the tops of thunderstorms into the ionosphere. The video/image above was caught by cameras normally used to monitor meteors. The jets themselves are red in color, a…
First Ice
The early light of dawn illuminates ice forming at the edge of this pond in Vermont. Caught after a frigid mid-November night, the ice is some of winter’s first. The interface between seasons reflects the interface in water phases. (Image credit: A. Raeder; via CUPOTY)
Tweaking Coalescence
When a drop settles gently against a pool of the same liquid, it will coalesce. The process is not always a complete one, though; sometimes a smaller droplet breaks away and remains behind (to eventually do its own settling and coalescence). When this happens, it’s known as partial coalescence. Here, researchers investigate ways to tune…
Billowing Ouzo
Pour the Greek liquor ouzo into water, and your glass will billow with a milky, white cloud, formed from tiny oil droplets. The drink’s unusual dynamics come from the interactions of three ingredients: water, oil, and ethanol. Ethanol is able to dissolve in both water and oil, but water and oil themselves do not mix.…
Underground Convection Thaws Permafrost Faster
In recent years, Arctic permafrost has thawed at a surprisingly fast pace. Much of that is, of course, due to the rapid warming caused by climate change. But some of that phenomenon lives underground, where water’s unusual properties cause convection in gaps between rocks, sediment, and soil. Water is densest not as ice but as…
Building Underwater Foundations
For bridges, deep-sea platforms, and marine wind turbines, engineers have to build secure foundations able to withstand extremely heavy loads. Just how do they do this? One technique — driven piles — is as simple as driving poles into the ground. This is the method medieval engineers used to establish the city of Venice, but…
“Microscopic World”
So many natural processes take place right in front of us, but they’re too small and too fast to see. Here, the Beauty of Science team puts some of those processes — crystallizing solids, nucleating bubbles, and more — front and center. The shapes and colors draw you in, inviting you to engage with science…
Pterosaur Tail Vanes
Among vertebrates, pterosaurs were the first to achieve powered flight. Early pterosaurs have tail vanes — similar in appearance to the frills seen on some lizards — but later species lost this feature. Whether the tail vanes helped in flight or served a display purpose is an open question among paleontologists. One group, in a…