Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
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Electronic Friction
Years ago, physicists discovered that water flows with surprisingly little friction through narrow carbon nanotubes. At our scale, flow behavior is typically the opposite: there’s greater friction (and, thus, slower flow) in a narrower pipe. To unravel the mystery, researchers had to delve into quantum mechanics and model the interactions between the atoms of a…
Watery Salt Flats
Unusually high rainfall in Bolivia’s Salar de Uyuni turned the world’s largest salt flat into a shallow salt lake. These natural-color satellite images show the area in late January 2022. If you zoom in on the full resolution image, there are incredible detailed swirls in the water. It’s like peering at an abstract or Impressionist…
Parametric Resonance
At first glance, Steve Mould’s video on parametric resonance has nothing whatsoever to do with fluid dynamics. He uses a pendulum suspended on a spring to demonstrate how driving a system at a frequency that’s a multiple of the system’s natural frequency can add energy through resonance. Although his examples don’t use fluids, this phenomenon…
Leidenfrost On Ice
We’ve seen many forms of Leidenfrost effect — that wild, near-frictionless glide that liquid droplets make on a very hot surface — over the years, but here’s a new one: the three-phase Leidenfrost effect. Researchers found that they could generate a Leidenfrost effect using an ice disk placed on an extremely hot surface. During the…
Spinning Tops
What does the flow look like around a spinning top? Here, researchers used dye to visualize what happens in a Newtonian fluid (like air or water) as well as a viscoelastic fluid. The Newtonian fluid (upper images) divides into two circulating zones, one below the top and one above. They both take the shape of…
Superhydrophobic Drag
Using air or bubbles to reduce drag on boats is a popular idea, whether using supercavitation, the Leidenfrost effect, or superhydrophobic coatings. But most of the experiments done thus far use spheres rather than realisitic boat shapes. In this study, the researchers used two model boats — one with a hydrofoil and the other in…
Fagradalsfjall Volcano
We’ve seen a lot of drone photography from volcanic eruptions in the last few years, but this footage from Iceland Aerials seems even more daredevil than usual. In this video, you can cruise over fountains of lava and watch as it cascades downhill. The perspective on some of these shots is absolutely unreal; it almost…
Eruption in a Box
In layers of viscous fluids, lighter and less viscous fluids can displace heavier, more viscous liquids. Here, researchers demonstrate this using four fluids sandwiched between layers of glass and mounted in a rotating frame. (Think of those liquid-air-sand art frames found in museums but bigger!) In their first example, each layer of fluid is denser…
Bendable Ice
Ice — as we typically encounter it — is extremely brittle and easily broken. That’s due to defects in the ice, places where atoms have settled into a spot that does not match the perfect crystalline alignment. Because tiny defect-free threads of ice made by researchers turn out to be wildly flexible! To make these…
Columbia Glacier’s Retreat
In southeastern Alaska, the Columbia Glacier once stretched as far as Heather Island in Prince William Sound. After a long period of stability, the glacier began retreating in 1980 and currently sits more than 15 miles from its previous extent. This video explores the glacier’s evolution through false-color satellite imagery, which allows researchers to distinguish…