Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Breaking
As waves fold over and break, they trap air, creating bubbles of many sizes. The smallest of these bubbles can be only a few microns across and persist for long times compared to larger bubbles. When they burst, they create tiny droplets that can carry sea salt up into the atmosphere to seed rain. Understanding…
Resonating on a Bounce
When we think of resonance, we often think of it in simple terms: hit the one right note, and the wine glass will shatter. But resonance isn’t always about a one-to-one ratio between a driving frequency and the resonating system. Especially in fluid dynamics, we often see responses that occur at other, related frequencies. One…
Recreating Pyroclastic Flow
One of the deadliest features of some volcanic eruptions is the pyroclastic flow, a current of hot gas and volcanic ash capable of moving hundreds of kilometers an hour and covering tens of kilometers. Since volcanic particles have a high static friction, it’s been something of a mystery how the flows can move so quickly.…
Coalescence at the Smallest Scales
The coalescence of two water droplets happens so quickly, it’s essentially impossible to see, even with high-speed cameras. For this reason, researchers have turned to simulating molecular dynamics – essentially building computer programs that model the actions of all the molecules contained in the water droplets. Viewed this way, the very first contact between drops…
Digging Sandpits
Antlion larvae dig sandpits to catch their prey, and, according to a new study, they rely on the physics of granular materials to do so. The antlion digs in a spiral pattern (bottom), beginning from the outside and working its way inward. As it digs, it ejects larger grains and triggers avalanches that cause large…
Fizzy Droplets
Leidenfrost drops surf on a layer of their own vapor, created by the high temperature of a nearby surface relative to their boiling point. These Leidenfrost drops can self-propel and skitter and skate across a surface, but they’re not the only droplets that do this. In this video, researchers show how a drop of carbonated…
Jumping Droplets
From butterfly wings to lotus leaves, many surfaces in nature are shaped to repel water. This typically means roughness on the scale of tens of nanometers, which helps trap air between water and the surface. Droplets can still form on these surfaces, but when they merge, the sudden excess of surface energy sends the coalesced…
Prehistoric Seiche
Sixty-six million years ago, a meteorite impact in modern-day Mexico wiped out the dinosaurs and most other living species of the time. To call the event catastrophic feels like an understatement. At the site of impact, rocks and animals were vaporized. Further away, molten rock condensed into glass beads that form a geological layer found…
The Beauty of Flames
The flickering yellow and orange flames most of us are used to thinking of are rather different from the flames researchers study. In this video, the Beauty of Science team offers a short primer on different flame shapes studied in combustion, including laminar, swirling, and jet flames. Each has its own distinctive character and may…
Vibrating in the Flow
Objects can obviously affect flows, but that’s not a one-way street. Flows can also affect objects, even ones as simple a circular cylinder. If you live somewhere with traffic lights mounted to a horizontal bar, you’ve probably seen this. On a windy day, the beam holding the traffic lights will oscillate up and down. This…