Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Kelvin-Helmholtz and the Sun
Kelvin-Helmholtz instabilities (KHI) are a favorite among fluid dynamicists. They resemble the curls of a breaking ocean wave — not a coincidence, since KHI create those ocean waves to begin with — and show up in picturesque clouds, Martian lava coils, and Jovian cloud bands. The instability occurs when two layers of fluid move at…
“Bulging Balloons”
This planet-like balloon started out as two elastomer sheets, heat-sealed together into a spiraling tube. As the balloon was inflated, it changed from flat to a saddle-like shape. With more air, the pressure inside increased, triggering an instability that caused the middle of the balloon to bulge. As inflation continued, the central bulge expanded, unbonding…
“Serenity”
Peering from directly above, landscapes take on a whole different aspect. That idea is the heart of Vadim Sherbakov’s “Serenity,” filmed by drone. From seething waters and meandering rivers to eroded landscapes and twisting ice, there’s lots of fluid dynamics on display here. (Video and image credit: V. Sherbakov)
Black Holes in a Blender
Massive black holes drag and warp the spacetime around them in extreme ways. Observing these effects firsthand is practically impossible, so physicists look for laboratory-sized analogs that behave similarly. Fluids offer one such avenue, since fluid dynamics mimics gravity if the fluid viscosity is low enough. To chase that near-zero viscosity, experimentalists turned to superfluid…
Etna’s Blowing Rings
Mount Etna has long been known for its smoke rings, but thanks to the opening of a new vent on the volcano’s southeast crater, it’s now making more rings than ever. Etna’s smoke rings are, more precisely, vortex rings — produced in the same way dolphins, swimmers, and whales make vortex rings: a sudden push…
Supernova Rings
Some 20,000 years ago, a massive star blew off a ring of dust and gas that expanded into the surrounding interstellar medium. Later, in 1987, the star exploded as supernova 1987A. That explosion lit the surrounding area, revealing a clumpy ring astronomers have struggled to explain. But a new team believes they have a fluid…
Millennium Falcon’s Glide
In what seems to be a tradition now, a group at MIT imagined how the Millennium Falcon would perform if it lost its engines during atmospheric flight. Their hypothetical scenario took place in the Battle of Endor, with the Falcon flying at an altitude of 2 kilometers.* Could Han Solo and Chewbecca safely glide the…
“Divebomb”
Seabirds like gannets and boobies are engineered for diving. They fly to a certain altitude, locate fish underwater, and then fold themselves into a streamlined projectile. With this, they plunge into the water at high-speed, positioned to protect themselves from the forces of impact. Under the water, they dart among their prey, hunting with singular…
Unsticking in Jumps
Soft materials tend to be sticky, and once they’re adhered to a surface, they’re often harder to remove than they were to attach — think of Scotch tape stuck to a desk. This difficulty separating sticky things — known as adhesion hysteresis — has been attributed to various causes, like energy lost to viscoelasticity or…
Kirigami Parachutes
To fly stably, parachutes need to deform and allow some air to pass through their canopy. In this video, researchers investigate kirigimi parachutes, inspired by a form of paper art that uses cuts to create three-dimensional shapes. After laser-cutting, these disks are dropped — or placed in a wind tunnel — to observe how they…