Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Scuba-Diving Fly
Mono Lake, three times saltier than the ocean, is an extreme environment by any measure. But for the alkali fly, it’s home. This extremophile insect dives into the lake, protected by a bubble sheath, to eat and lay eggs. The fly’s wings and body are covered in tiny, waxed hairs that repel water. That traps…
Packing Disks
Liquid crystals, bottles of pills, and hoppers of grains can all involve disk-shaped particles. To better understand how disks pack together, researchers studied how disks in a box orient themselves after shaking. They used MRI to observe the disks’ interior packing. The team found that shaking increases the disks’ density, but that increase does not…
Star YY Hya
A team of professional and amateur astronomers discovered and then imaged this previously undiscovered galactic nebula. At the heart of the stellar remnant is a binary star pair. Shock waves of the gas and dust twist and spread in the surrounding space, the remains of an earlier star’s violent eruption. (Image credit: M. Drechsler et…
Vivid Auroras Over Iceland
When solar storms in late February sent energetic particles toward Earth, photographer Cari Letelier ventured to the remote northern edge of Iceland to capture the resulting auroras. When fast-moving, high-energy particles from the solar wind meet Earth’s magnetosphere, they’re directed toward the poles. There the particles slam into Earth’s upper atmosphere, exciting atoms that glow…
Forests Slow Avalanches
In snowy mountainous regions, avalanches are a dangerous and destructive problem. Researchers studying the mechanisms of these flows have a suggestion: plant more trees. A group of researchers found that a “forest” of regularly spaced pillars slowed avalanches by as much as two-thirds. On an empty slope, the avalanche picked up speed as its thickness…
Capturing the Tides
Twice a day the tides rise and fall along coastlines. Increasingly, engineers are trying to harness these regular currents for clean energy. Tidal turbines spin during the fastest flows, turning a rotor that powers an electrical generator. Compared to wind and solar energy, tidal energy is expensive, but it’s also predictable — a feature wind…
Scooting Droplets
As a child, I always loved watching rain on the windows as I rode in the car. Hemispherical droplets got stretched by the wind flowing over them. But they never stretched smoothly; instead they seemed to shiver and shake unevenly. A recent study looks at a similar situation: drops of glycerin forced to slide along…
“Aquakosmos”
Colorful chandeliers, passing spirits, sprouting mushrooms, and fountains of falling ink appear in Christopher Dormoy’s “Aquakosmos.” Driven by the slight density difference between ink and water, many of these elaborate shapes result from the Rayleigh-Taylor instability. Anytime you see mushroom-like plumes and chandelier-like splitting vortex rings, there’s probably a Rayleigh-Taylor instability behind it. Check out…
Stopping a Bottle’s Bounce
A few years ago, the Internet was abuzz with water bottle flips. Experimentalists are still looking at how they can arrest a partially fluid-filled container’s bounce, but now they’re rotating the bottles vertically rather than flipping them end-over-end. Their work shows that faster rotating bottles have little to no bounce after impacting a surface. The…